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Κυριακή 22 Απριλίου 2018

mRECIST criteria to assess recurrent thyroid carcinoma treatment response after radiofrequency ablation: a prospective study

Abstract

Purpose

Surgical removal is recommended for recurrent thyroid carcinomas (RTCs) unable to uptake radioiodine and/or not responsive to chemotherapy. However, repeated neck dissection is difficult for surgeons. Thus, radiofrequency ablation (RFA) was proposed for RTCs. The aim of this prospective study is to assess RTC treatment response after RFA, according to well-established criteria.

Methods

Sixteen lesions in 13 patients were treated by RFA. All patients refused/were excluded from repeated surgery or other conventional therapy. CT and US examinations were performed before RFA to evaluate lesion volume and vascularization. All RFA procedures were performed under US-guidance by an 18-gauge, electrode. Treatment response was evaluated by CT, according to RECIST 1.1 and to mRECIST guidelines; CT examinations were performed during follow-up (6–18 months); the volume of residual vital tumour tissue and the percentage of necrotic tissue were estimated by contrast enhanced CT.

Results

RFA was well tolerated by all patients; in two cases laryngeal nerve paralysis was observed. Mean pre-treatment volume was 4.18 ± 3.53 ml. Vital tumour tissue and percentage of necrosis at 6, 12 and 18 months were 0.18 ± 0.25, 0.11 ± 0.13, 0.29 ± 0.40 ml and 91.9 ± 11.1, 90.4 ± 13.3, 80.8 ± 23.1%. According to RECIST 1.1, target lesion response was classified as complete response (CR) in one case, partial response (PR) in 11/16, stable disease in 4/16 cases. According to mRECIST, 11/16 cases were classified as CR and the remaining 5 as PR.

Conclusion

RFA is a safe procedure to treat the viable tumour tissue and to reduce the RTC volume; as to the criteria to assess treatment response, mRECIST appears to be more accurate.



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Microbial fuel cells coupling with the three-dimensional electro-Fenton technique enhances the degradation of methyl orange in the wastewater

Abstract

The emission of the source effluent of azo dyes has resulted in a serial of environmental problems including of the direct damage of the natural esthetics, the inhibition of the oxygen exchange, the shortage of the photosynthesis, and the reduction of the aquatic flora and fauna. A bioelectrochemical platform (3D-EF-MFCs) combining two-chamber microbial fuel cells and three dimensional electro-Fenton technique were delicately designed and assembled to explore the decolorization, bio-genericity performance of the methyl orange, and the possible biotic-abiotic degradation mechanisms. The 3D-EF-MFCs processes showed higher decolorization efficiencies, COD removals, and better bioelectricity performance than the pure electro-Fenton-microbial fuel cell (EF-MFC) systems. The two-chamber experiments filling with the granular activated carbons were better than the single-chamber packing system on the whole. The moderate increase of Fe2+ ions dosing in the cathode chamber accelerated the formation of •OH, which further enhanced the degradation of the methyl orange (MO). The cathode-decolorization and COD removals were decreased with the increase of MO concentration. However, the degradation performance of MO was indirectly improved in the anode compartment at the same conditions. The bed electrodes played a mediator role in the anode and cathode chambers, certainly elevated the voltage output and the power density, and lowered the internal impedance of EF-MFC process.



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Conditional deletion of Id2 or Notch1 in oligodendrocyte progenitor cells does not ameliorate disease outcome in SOD1G93A mice

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Publication date: August 2018
Source:Neurobiology of Aging, Volume 68
Author(s): Caroline Eykens, Annelies Nonneman, Cathy Jensen, Antonio Iavarone, Philip Van Damme, Ludo Van Den Bosch, Wim Robberecht
Oligodendrocytes are essential for structural and trophic support of motor axons. Their impairment has been implicated in amyotrophic lateral sclerosis (ALS), a neurodegenerative disorder of motor neurons. Oligodendrocyte progenitor cells fail to differentiate into mature oligodendrocytes and thereby jeopardize the health of motor neurons. Here, we report that oligodendrocytic ablation of inhibitor of DNA binding 2 (Id2) or Notch receptor 1 (Notch1), 2 negative master modulators of oligodendrocyte differentiation, fails to alleviate oligodendrocyte dysfunction or alter disease outcome in a murine model of ALS. Our data suggest that these inhibitors are not suitable targets for intervention in ALS.



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The lysosome system is severely impaired in a cellular model of neurodegeneration induced by HSV-1 and oxidative stress

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Publication date: August 2018
Source:Neurobiology of Aging, Volume 68
Author(s): Henrike Kristen, Isabel Sastre, Teresa Muñoz-Galdeano, Maria Recuero, Jesus Aldudo, Maria J. Bullido
The causal agent(s) and molecular mechanisms of Alzheimer's disease (AD) remain unclear. Mounting evidence suggests that herpes simplex virus type 1 (HSV-1) infection is involved in the AD pathogenesis. Oxidative stress (OS) may also be crucial in the AD development. Our group previously reported that both HSV-1 and OS trigger the appearance of AD-type neurodegeneration markers. The main aim of the present study was to identify the mechanisms involved in this triggering. Expression studies revealed the involvement of a set of OS-regulated genes in HSV-1-infected cells and in cells harboring the Swedish mutation of the amyloid beta precursor protein gene. Functional annotation of these genes revealed the lysosome system to be impaired, suggesting that the interaction of OS with both HSV-1 and amyloid beta precursor protein mutations affects lysosomal function. Functional studies revealed HSV-1 infection and OS to increase the lysosome load, reduce the activity of lysosomal hydrolases, affect cathepsin maturation, and inhibit the endocytosis-mediated degradation of the epidermal growth factor receptor. These findings suggest alterations in the lysosome system to be involved in different forms of AD.



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Distribution, fractions, and potential release of thallium in acidic soils nearby a waste copper mining site from southern China

Abstract

Although thallium (Tl) is a highly toxic element, little information is available on the environmental risks of Tl in agricultural soils with intensive practices, particularly nearby mining sites. Therefore, we investigated the potential release of Tl in acidic soils with intensive cultivation nearby a waste copper mining site from southern China based on its level and chemical fractions as well as simulated release under artificial acid rain. Results showed that the average Tl content was 1.31 mg/kg in the studied area, which significantly exceeds the permissible thallium value of 1 mg/kg for agricultural soil in China. Some vertical increases of soil Tl from different land uses indicate the potential transport of Tl downward to groundwater. High positive correlations between surficial soil Tl and rubidium (Rb) and copper (Cu) indicated that Tl has the lithophile and chalcophile behavior. Tl in soils is mainly entrapped in residual fraction. The exchangeable fraction of Tl in agricultural soils was less than undisturbed natural soils and copper mined soils. Additionally, the percentage of Tl release from undisturbed natural soils and soils of copper ore area was more than that from agricultural soils in simulated acid rain. Furthermore, the releases of Tl from the soils increased with the acidity of artificial acid rain. Thus, more attention must be paid to land management of this similar area to avoid the risk of Tl impact on human health.



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Influence of fishing activity over the marine debris composition close to coastal jetty

Abstract

Worldwide, the marine debris emissions have been provoking impacts in ecosystems, generating massive mortality of different species with commercial interest. In South America, we have a lack of studies to verify the marine debris composition in transitional environments such as adjacent regions of coastal jetties. These are hydraulic engineering constructions used to maintain the navigation channel access between the sea-estuarine interface and are also used by teleost fishes, crustaceans, and mollusks like artificial shelters (reefs), being excellent fishing grounds. Therefore, the present study was devoted to qualitatively evaluate the composition of marine debris in an internal jetty portion of a Laguna Estuarine System (LES) located in South America (Brazil). Six hundred freediving were conducted to collect marine debris in the study region. The in situ campaigns were performed in 2016 during all spring season (sand substrata) in four distinct zones with 26,400 m2 each one covering almost all adjacent jetty extension, to evaluate possible spatial changes in the marine debris composition. All material obtained was identified, measured, weighed, and ordered in eight groups, with six groups being related to the fishing activity and two groups related to the tourism/community in the study region. So, it was possible to observe possible relations between the marine debris distribution to artisanal and recreational local fishing. After 600 freediving sampling efforts, 2142 marine debris items were obtained, totaling close to 100 kg of solid waste removed from the inner portion of the coastal jetty. Notably, 1752 units (50 kg) of fishing leads were collected being this item the main marine debris residue found in the four sampled areas, corresponding to nearly 50% of the total weight of the collected waste. Ninety-eight percent of marine debris were derived from the local fishing activities, and just 2% were derived from tourism/community. Considering the total contribution related to fishing, 83% of the marine debris were composed by lead (sinkers) adopted by recreational and artisanal fishing. Notably, the catch activity in this region has a close influence over the marine debris composition. Reductions of marine debris emissions derived from the fishing activities have been a global challenge, once this problem is occurring in practically all marine and estuarine environments under the anthropic action. The presence of marine debris changes the local landscape and can provoke serious environmental problems, such as ghost fishing that affects a wide variability of marine mammals, birds, and fishes. Most of marine debris collected came from recreational and artisanal fishing, being the fishing leads the most prominent material, especially in sector 4. This fact is possibly related to the intense mullet fishing using cast nets, usual in this sample area. In the other sectors, there was a great predominance of grapnel fishing leads, widely adopted by recreational fishermen in open water environments. The "fingernails" present in these fishing leads ensure the sinking of the line for a specific location independently of possible flow oscillations of the tidal current and/or currents generated by winds. The massive quantity of fishing leads into the sectors is a dangerous fact. Notably, lead is a heavy, non-biodegradable, and extremely toxic metal that, due to the anthropogenic activities, has been increasing around the world. Future efforts in our study region should evaluate the seasonal marine debris composition to observe possible changes along the different seasons of the year. In this way, it would be possible to infer quantitatively the emission of marine debris derived from the fishing activity, assessing its impacts and enabling the adoption of environmental management strategies. This effort adopted a qualitative analysis, serving to show the current situation of this region that we now know to be vulnerable to the presence of marine debris derived from the fishing activity.



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Balloon-borne tropospheric CO2 observations over the equatorial eastern and western Pacific

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Publication date: July 2018
Source:Atmospheric Environment, Volume 184
Author(s): Yoichi Inai, Shuji Aoki, Hideyuki Honda, Hiroshi Furutani, Yutaka Matsumi, Mai Ouchi, Satoshi Sugawara, Fumio Hasebe, Mitsuo Uematsu, Masatomo Fujiwara
Vertical profiles of carbon dioxide (CO2) mixing ratio in the equatorial eastern and western Pacific were measured by newly developed balloon-borne CO2 sondes in February 2012 (two soundings) and February–March 2015 (four soundings), respectively. The 1–10 km vertically averaged CO2 mixing ratios lie between the background surface values in the Northern Hemisphere (NH) and those in the Southern Hemisphere (SH) monitored at ground-based sites during these periods. A backward trajectory analysis, taking account of convective mixing processes using geostationary satellite cloud-image data, is applied to the measured CO2 profiles to estimate the origin of the observed air masses. Air masses originating in the SH show low CO2 mixing ratios that are similar to the background values in the SH. This relationship is confirmed by a positive correlation (∼0.6) between the CO2 mixing ratio and the latitude of air mass origin which is found from trajectory calculations. This result suggests that the CO2 distribution in the troposphere over the equatorial Pacific is controlled by monthly time-scale, large-scale CO2 distribution and weekly time-scale atmospheric transport processes. Furthermore, this study shows that the combination of CO2 sonde measurements and trajectory analysis, taking account of convective mixing, is a useful tool in investigating CO2 transport processes.



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Meta-modeling of ADMS-Urban by dimension reduction and emulation

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Publication date: July 2018
Source:Atmospheric Environment, Volume 184
Author(s): Vivien Mallet, Anne Tilloy, David Poulet, Sylvain Girard, Fabien Brocheton
ADMS-Urban is a non-linear, static, urban air quality model, with high-dimensional outputs. A simulation of NO2 and PM10 concentrations every hour during a full year and over an entire city can take dozens of days of computations, which greatly limits the range of methods that can be applied to the model, especially for uncertainty quantification. This work presents a method to replace the complete model, ADMS-Urban, with a meta-model or surrogate model, i.e., a reasonably close approximation of ADMS-Urban whose computational cost is negligible. When the emissions are formulated as a function of the day and the hour, the complete-model inputs essentially contain a few scalar values, to describe the meteorological conditions, the background pollution and the target date. The complete-model outputs are first projected onto a reduced subspace. The relations between the projection coefficients and the low-dimensional inputs are then emulated by a fast statistical emulator, based on Kriging or radial basis functions (RBF). The mean error between the meta-model and ADMS-Urban is 22% with Kriging and 27% with RBF for NO2, and 14% with Kriging and 20% with RBF for PM10. The meta-model performs as well as ADMS-Urban when compared to the observations. Its computational cost is almost negligible to compute the concentrations at a given hour and date for an entire city: 50 ms with RBF and 150 ms with Kriging to simulate 1 h on one core, while the complete model requires 8 min on 16 cores.



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The effect of heat recovery on near-source plume dispersion of a simple cycle gas turbine

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Publication date: July 2018
Source:Atmospheric Environment, Volume 184
Author(s): Bo Yang, Jiajun Gu, K. Max Zhang
The waste heat recovery (HR) systems are employed to increase the overall thermal efficiency of electric generation units (EGUs). Although the emission factors (in terms of gram of pollutants per unit of thermal energy consumed or electric energy generated) generally decreases after installing HR systems, the emission rates in terms of grams of pollutants per unit of time remain unchanged. However, HR systems reduce stack exit temperature, resulting in lower effective emission heights, which lead to higher near-source ground level concentrations (GLCs) of air pollutants. In order to comprehensively evaluate the near-source air quality impact from deploying HR systems, we proposed a new modeling framework by integrating a computationally efficient Gaussian-based dispersion model (AERMOD) and a (relatively) more accurate computational fluid dynamics (CFD) model. As a demonstration of the proposed framework, we investigated the HR impact on NOx concentrations near a simple cycle gas turbine located in Brentwood, NY. Specifically, we applied the AERMOD modeling system to screen the hourly GLCs over five years, and highest values (and the corresponding hours) were shown to cluster into two main meteorological conditions: the stable atmospheric boundary layer with relatively high wind speed (Stable, HW) and the unstable atmospheric boundary layer with relatively low wind speed (Unstable, LW). These two conditions were further simulated using a CFD model that have been extensively evaluated previously for detailed analysis. By setting different stack exit temperatures, the near-source air quality impact of different waste heat conversion rates was evaluated. We introduced a concept called the heat recovery amplified factor (HRAF), defined as the ratio between the maximum GLC with HR system and that without HR system, as an indicator of HR impact. HRAF was shown to be much more sensitive to temperature in the Unstable, LW condition than in the Stable, HW condition. Although the results were limited to a specific simple cycle gas turbine, the proposed modeling framework and HRAF can be used for evaluating the HR systems impact for other emission sources.



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Evaluating EDGARv4.tox2 speciated mercury emissions ex-post scenarios and their impacts on modelled global and regional wet deposition patterns

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Publication date: July 2018
Source:Atmospheric Environment, Volume 184
Author(s): Marilena Muntean, Greet Janssens-Maenhout, Shaojie Song, Amanda Giang, Noelle E. Selin, Hui Zhong, Yu Zhao, Jos G.J. Olivier, Diego Guizzardi, Monica Crippa, Edwin Schaaf, Frank Dentener
Speciated mercury gridded emissions inventories together with chemical transport models and concentration measurements are essential when investigating both the effectiveness of mitigation measures and the mercury cycle in the environment. Since different mercury species have contrasting behaviour in the atmosphere, their proportion in anthropogenic emissions could determine the spatial impacts. In this study, the time series from 1970 to 2012 of the EDGARv4.tox2 global mercury emissions inventory are described; the total global mercury emission in 2010 is 1772 tonnes. Global grid-maps with geospatial distribution of mercury emissions at a 0.1° × 0.1° resolution are provided for each year. Compared to the previous tox1 version, tox2 provides updates for more recent years and improved emissions in particular for agricultural waste burning, power generation and artisanal and small-scale gold mining (ASGM) sectors. We have also developed three retrospective emissions scenarios based on different hypotheses related to the proportion of mercury species in the total mercury emissions for each activity sector; improvements in emissions speciation are seen when using information primarily from field measurements. We evaluated them using the GEOS-Chem 3-D mercury model in order to explore the influence of speciation shifts, to reactive mercury forms in particular, on regional wet deposition patterns. The reference scenario S1 (EDGARv4.tox2_S1) uses speciation factors from the Arctic Monitoring and Assessment Programme (AMAP); scenario S2 ("EPA_power") uses factors from EPA's Information Collection Request (ICR); and scenario S3 ("Asia_filedM") factors from recent scientific publications. In the reference scenario, the sum of reactive mercury emissions (Hg-P and Hg2+) accounted for 25.3% of the total global emissions; the regions/countries that have shares of reactive mercury emissions higher than 6% in total global reactive mercury are China+ (30.9%), India+ (12.5%) and the United States (9.9%). In 2010, the variations of reactive mercury emissions amongst the different scenarios are in the range of −19.3 t/yr (China+) to 4.4 t/yr (OECD_Europe). However, at the sector level, the variation could be different, e.g., for the iron and steel industry in China reaches 15.4 t/yr. Model evaluation at the global level shows a variation of approximately ±10% in wet deposition for the three emissions scenarios. An evaluation of the impact of mercury speciation within nested grid sensitivity simulations is performed for the United States and modelled wet deposition fluxes are compared with measurements. These studies show that using the S2 and S3 emissions of reactive mercury, can improve wet deposition estimates near sources.



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On the use of superparamagnetic hydroxyapatite nanoparticles as an agent for magnetic and nuclear in vivo imaging

Publication date: Available online 22 April 2018
Source:Acta Biomaterialia
Author(s): Alessio Adamiano, Michele Iafisco, Monica Sandri, Martina Basini, Paolo Arosio, Tamara Canu, Giovanni Sitia, Antonio Esposito, Vincenzo Iannotti, Giovanni Ausanio, Eirini Fragogeorgi, Maritina Rouchota, George Loudos, Alessandro Lascialfari, Anna Tampieri
The identification of alternative biocompatible magnetic NPs for advanced clinical application is becoming an important need due to raising concerns about iron accumulation in soft issues associated to the administration of superparamagnetic iron oxide nanoparticles (NPs). Here, we report on the performance of previously synthetized iron-doped hydroxyapatite (FeHA) NPs as contrast agent for magnetic resonance imaging (MRI). The MRI contrast abilities of FeHA and Endorem® (dextran coated iron oxide NPs) were assessed by 1H nuclear magnetic resonance relaxometry and their performance in healthy mice was monitored by a 7 Tesla scanner. FeHA applied a higher contrast enhancement, and had a longer endurance in the liver with respect to Endorem® at iron equality. Additionally, a proof of concept of FeHA use as scintigraphy imaging agent for positron emission tomography (PET) and single photon emission computed tomography (SPECT) was given labeling FeHA with 99mTc-MDP by a straightforward surface functionalization process. Scintigraphy/x-ray fused imaging and ex vivo studies confirmed its dominant accumulation in the liver, and secondarily in other mononuclear phagocyte system organs. FeHA efficiency as MRI-T2 and PET-SPECT imaging agent combined to its already reported intrinsic biocompatibility qualify this material as promising for innovative nanomedical applications.Statement of SignificanceThe ability of iron-doped hydroxyapatite nanoaprticles (FeHA) to work in vivo as imaging agents for magnetic resonance (MR) and nuclear imaging is demonstrated. FeHA applied an higher MR contrast in the liver, spleen and kidneys of mice with respect to Endorem®. The successful radiolabeling of FeHA allowed for scintigraphy/X-ray and ex vivo biodistribution studies, confirming MR results and envisioning FeHA application for dual-imaging

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Bioadhesives for Internal Medical Applications: A Review

Publication date: Available online 22 April 2018
Source:Acta Biomaterialia
Author(s): Wenzhen Zhu, Yon Jin Chuah, Dong-An Wang
Bioadhesives such as tissue adhesives, hemostatic agents, and tissue sealants have gained increasing popularity in different areas of clinical operations during the last three decades. Bioadhesives can be categorized into internal and external ones according to their application conditions. External bioadhesives are generally applied in topical medications such as wound closure and epidermal grafting. Internal bioadhesives are mainly used in intracorporal conditions with direct contact to internal environment including tissues, organs and body fluids, such as chronic organ leak repair and bleeding complication reduction. This review focuses on internal bioadhesives that, in contrast with external bioadhesives, emphasize much more on biocompatibility and adhesive ability to wet surfaces rather than on gluing time and intensity. The crosslinking mechanisms of present internal bioadhesives can be generally classified as follows: 1) chemical conjugation between reactive groups; 2) free radical polymerization by light or redox initiation; 3) biological or biochemical coupling with specificity; and 4) biomimetic adhesion inspired from natural phenomena. In this review, bioadhesive products of each class are summarized and discussed by comparing their designs, features, and applications as well as their prospects for future development.Statement of SignificanceDespite the emergence of numerous novel bioadhesive formulations in recent years, thus far, the classification of internal and external bioadhesives has not been well defined and universally acknowledged. Many of the formulations have been proposed for treatment of several diseases even though they are not applicable for such conditions. This is because of the lack of a systematic standard or evaluation protocol during the development of a new adhesive product. In this review, the definition of internal and external bioadhesives is given for the first time, and with a focus on internal bioadhesives, the criteria of an ideal internal bioadhesive are adequately discussed; this is followed by the review of recently developed internal bioadhesives based on different gluing mechanisms.

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A polypeptide based podophyllotoxin conjugate for the treatment of multi drug resistant breast cancer with enhanced efficiency and minimal toxicity

Publication date: Available online 22 April 2018
Source:Acta Biomaterialia
Author(s): Huicong Zhou, Shixian Lv, Dawei Zhang, Mingxiao Deng, Xuefei Zhang, Zhaohui Tang, Xuesi Chen
Podophyllotoxin (PPT) is a chemotherapeutic agent which has shown significant activity against P-glycoprotein (P-gp) mediated multi drug resistant cancer cells. However, because of the poor aqueous solubility and high toxicity, PPT cannot be used in clinical cancer therapy. In order to enhance the efficiency and reduce side effect of PPT, a polypeptide based PPT conjugate PLG-g-mPEG-PPT was developed and used for the treatment of multi drug resistant breast cancer. The PLG-g-mPEG-PPT was prepared by conjugating PPT to poly(L-glutamic acid)-g-methoxy poly(ethylene glycol) (PLG-g-mPEG) via ester bonds. The PPT conjugates self-assembled into nanoparticles with average sizes about 100 nm in aqueous solution. Western blotting assay showed that the PLG-g-mPEG-PPT could effectively inhibit the expression of P-gp in the multiple drug resistant MCF-7/ADR cells. In vitro cytotoxicity assay indicated that the resistance index (RI) values of PLG-g-mPEG-PPT on different drug-resistant cancer cell lines exhibited 57-270 folds reduction than of traditional microtubule inhibitor chemotherapeutic drug PTX or DTX. Hemolysis assay demonstrated that the conjugation greatly decreased the hemolytic activity of free PPT. Maximum tolerated dose (MTD) of PLG-g-mPEG-PPT increased greatly (13.3 folds) as compared to that of free PPT. In vivo study showed that the PLG-g-mPEG-PPT conjugate remarkably enhanced the antitumor efficacy against MCF-7/ADR xenograft tumors with an tumor suppression rate (TSR) of 82.5%, displayed significantly improved anticancer efficacy as compared to free PPT (TSR=37.1%) with minimal toxicity when both of the two formulations were used in MTD.Statement of SignificanceThe development of multiple drug resistance (MDR) of cancer cells is the main cause of chemotherapy failure. The over-expression of P-glycoprotein (P-gp) has been recognized to be the most important cause of MDR in cancer. Podophyllotoxin (PPT) is a chemotherapeutic agent which has shown strong activity against P-gp mediated multidrug resistant cancer cells by simultaneously inhibiting the over-expression of P-gp and the growth of cancer cells. However, PPT can not be used in clinical cancer treatment due to its poor aqueous solubility and high toxicity. Herein, we developed a polypeptide based PPT conjugate PLG-g-mPEG-PPT by conjugating PPT to poly(L-glutamic acid)-g-methoxy poly(ethylene glycol). The PLG-g-mPEG-PPT shows significantly decreased hemolytic activity, greatly improved maximum tolerated dose and remarkably enhanced antitumor efficacy against MCF-7/ADR xenograft tumors as compared to free PPT.

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Graphene oxide reinforced core–shell structured Ag@Cu2O with tunable hierarchical morphologies and their morphology–dependent electrocatalytic properties for bio-sensing applications

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Publication date: 30 July 2018
Source:Biosensors and Bioelectronics, Volume 112
Author(s): Tian Gan, Zhikai Wang, Zhaoxia Shi, Dongyun Zheng, Junyong Sun, Yanming Liu
In this study, a facile solution approach was developed for the synthesis of a series of core–shell structured Ag@Cu2O nanocrystals of various shapes including triangles, spheres, and cubes with well–defined stable heterojunctions. The electrooxidation of dopamine (DA), uric acid (UA), guanine (G), and adenine (A) using these hybrids revealed morphology–dependent sensing properties, with activities and accumulation ability following the order, triangular Ag@Cu2O > spherical Ag@Cu2O > cubic Ag@Cu2O. Further, we constructed a novel graphene oxide (GO) nanosheet–reinforced triangular Ag@Cu2O ternary hetero–nanostructure. Such a hybrid with a three–dimensional interconnected hierarchical architecture is suitable for catalysis, since it not only leads to improved interfacial electron transfer, but also readily exposes the highly catalytic Ag@Cu2O to the reactants. Therefore, more enhanced electrochemical activities were observed for the oxidation of DA, UA, G, and A. This study provides an efficient way to synthesize morphology–controlled Ag@Cu2O heterogeneous catalysts for the fabrication of potential biosensors, and also opens up attractive avenues in the design of multifunctional ternary noble metal–semiconductor–carbon hybrids.



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A robust electrochemical immunosensor based on hydroxyl pillar[5]arene@AuNPs@g-C3N4 hybrid nanomaterial for ultrasensitive detection of prostate specific antigen

Publication date: 30 July 2018
Source:Biosensors and Bioelectronics, Volume 112
Author(s): Xu Zhou, Long Yang, Xiaoping Tan, Genfu Zhao, Xiaoguang Xie, Guanben Du
Prostate specific antigen (PSA) is the most significant biomarker for the screening of prostate cancer in human serum. However, most methods for the detection of PSA often require major laboratories, precisely analytical instruments and complicated operations. Currently, the design and development of satisfying electrochemical biosensors based on biomimetic materials (e.g. synthetic receptors) and nanotechnology is highly desired. Thus, we focused on the combination of molecular recognition and versatile nanomaterials in electrochemical devices for advancing their analytical performance and robustness. Herein, by using the present prepared multifunctional hydroxyl pillar[5]arene@gold nanoparticles@graphitic carbon nitride (HP5@AuNPs@g–C3N4) hybrid nanomaterial as robust biomimetic element, a high-performance electrochemical immunosensor for detection of PSA was constructed. The as-prepared immunosensor, with typically competitive advantages of low cost, simple preparation and fast detection, exhibited remarkable robustness, ultra-sensitivity, excellent selectivity and reproducibility. The limit of detection (LOD) and linear range were 0.12 pg mL–1 (S/N = 3) and 0.0005–10.00 ng mL–1, respectively. The satisfying results provide a promising approach for clinical detection of PSA in human serum.

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Electrochemiluminescence quenching of luminol by CuS in situ grown on reduced graphene oxide for detection of N-terminal pro-brain natriuretic peptide

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Publication date: 30 July 2018
Source:Biosensors and Bioelectronics, Volume 112
Author(s): Xiaojian Li, Peng Lu, Bin Wu, Yaoguang Wang, Huan Wang, Bin Du, Xuehui Pang, Qin Wei
A novel electrochemiluminescence (ECL) signal-off strategy based on CuS in situ grown on reduced graphene oxide (CuS-rGO) quenching luminol/H2O2 system was firstly proposed. Luminol was grafted on the surface of Au@Fe3O4-Cu3(PO4)2 nanoflowers (Luminol-Au@Fe3O4-Cu3(PO4)2) which exhibited excellent catalytic effect towards the reduction of H2O2 to enhance the ECL intensity of luminol. Cu3(PO4)2 nanoflowers showed large surface area which can immobilize more Fe3O4 and Au nanoparticles. The quenching mechanism of CuS-rGO was due to ECL resonance energy transfer (RET). The spectral overlap between fluorescence spectrum of Luminol-Au@Fe3O4-Cu3(PO4)2 and UV–vis absorption spectrum of CuS-rGO revealed that resonance energy transfer was possible. Au nanoparticles were immobilized on the surface of CuS-rGO to capture secondary antibodies. After a sandwich-type immunoreaction, a remarkable decrease of ECL signal was observed. Under the optimal conditions, the immunosensor showed excellent performance for N-terminal pro-brain natriuretic peptide (NT-proBNP) detection with a wide detection range from 0.5 pg mL−1 to 20 ng mL−1 and a low detection limit of 0.12 pg mL−1 (S/N = 3). The prepared NT-proBNP immunosensor displayed high sensitivity, excellent stability and good specificity.



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Alpha-lactose reverses liver injury via blockade of Tim-3-mediated CD8 apoptosis in sepsis

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Publication date: Available online 22 April 2018
Source:Clinical Immunology
Author(s): Zhengping Wei, Pingfei Li, Yao Yao, Hai Deng, Shengwu Yi, Cong Zhang, Han Wu, Xiuxiu Xie, Minghui Xia, Ran He, Xiang-Ping Yang, Zhao-Hui Tang
In sepsis, the liver plays a crucial role in regulating immune responses and is also a target organ for immune-related injury. Despite the critical function of CD8+ T cells against opportunistic viral infections, the CD8 immune response in the liver during sepsis remains elusive. Here we found that Tim-3 is highly up-regulated in liver CD8+ T cells in a mouse cecal ligation and puncture model and in peripheral blood CD8+ T cells of human patients with sepsis. The expression of Tim-3 in liver CD8+ T cells displayed a bi-phasic pattern and deletion of Tim-3 led to reduction of CD8+ T cell apoptosis. Administration of α-lactose, a molecule with a similar structure to galactin-9, reduced Tim-3 expression and liver injury in sepsis. Our results demonstrate that targeting Tim-3 to boost CD8+ T cell immune response may offer an improved outcome in patients with sepsis.



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Absolute cosine-based SVM-RFE feature selection method for prostate histopathological grading

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Publication date: Available online 19 April 2018
Source:Artificial Intelligence in Medicine
Author(s): Shahnorbanun Sahran, Dheeb Albashish, Azizi Abdullah, Nordashima Abd Shukor, Suria Hayati Md Pauzi
ObjectiveFeature selection (FS) methods are widely used in grading and diagnosing prostate histopathological images. In this context, FS is based on the texture features obtained from the lumen, nuclei, cytoplasm and stroma, all of which are important tissue components. However, it is difficult to represent the high-dimensional textures of these tissue components. To solve this problem, we propose a new FS method that enables the selection of features with minimal redundancy in the tissue components.MethodologyWe categorise tissue images based on the texture of individual tissue components via the construction of a single classifier and also construct an ensemble learning model by merging the values obtained by each classifier. Another issue that arises is overfitting due to the high-dimensional texture of individual tissue components. We propose a new FS method, SVM-RFE(AC), that integrates a Support Vector Machine-Recursive Feature Elimination (SVM-RFE) embedded procedure with an absolute cosine (AC) filter method to prevent redundancy in the selected features of the SV-RFE and an unoptimised classifier in the AC.ResultsWe conducted experiments on H&E histopathological prostate and colon cancer images with respect to three prostate classifications, namely benign vs. grade 3, benign vs. grade 4 and grade 3 vs. grade 4. The colon benchmark dataset requires a distinction between grades 1 and 2, which are the most difficult cases to distinguish in the colon domain. The results obtained by both the single and ensemble classification models (which uses the product rule as its merging method) confirm that the proposed SVM-RFE(AC) is superior to the other SVM and SVM-RFE-based methods.ConclusionWe developed an FS method based on SVM-RFE and AC and successfully showed that its use enabled the identification of the most crucial texture feature of each tissue component. Thus, it makes possible the distinction between multiple Gleason grades (e.g. grade 3 vs. grade 4) and its performance is far superior to other reported FS methods.



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Segmentation of corneal endothelium images using a U-Net-based convolutional neural network

Publication date: Available online 19 April 2018
Source:Artificial Intelligence in Medicine
Author(s): Anna Fabijańska
Diagnostic information regarding the health status of the corneal endothelium may be obtained by analyzing the size and the shape of the endothelial cells in specular microscopy images. Prior to the analysis, the endothelial cells need to be extracted from the image. Up to today, this has been performed manually or semi-automatically. Several approaches to automatic segmentation of endothelial cells exist; however, none of them is perfect. Therefore this paper proposes to perform cell segmentation using a U-Net-based convolutional neural network. Particularly, the network is trained to discriminate pixels located at the borders between cells. The edge probability map outputted by the network is next binarized and skeletonized in order to obtain one-pixel wide edges. The proposed solution was tested on a dataset consisting of 30 corneal endothelial images presenting cells of different sizes, achieving an AUROC level of 0.92. The resulting DICE is on average equal to 0.86, which is a good result, regarding the thickness of the compared edges. The corresponding mean absolute percentage error of cell number is at the level of 4.5% which confirms the high accuracy of the proposed approach. The resulting cell edges are well aligned to the ground truths and require a limited number of manual corrections. This also results in accurate values of the cell morphometric parameters. The corresponding errors range from 5.2% for endothelial cell density, through 6.2% for cell hexagonality to 11.93% for the coefficient of variation of the cell size.

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Handwritten dynamics assessment through convolutional neural networks: An application to Parkinson's disease identification

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Publication date: Available online 16 April 2018
Source:Artificial Intelligence in Medicine
Author(s): Clayton R. Pereira, Danilo R. Pereira, Gustavo H. Rosa, Victor H.C. Albuquerque, Silke A.T. Weber, Christian Hook, João P. Papa
Background and objectiveParkinson's disease (PD) is considered a degenerative disorder that affects the motor system, which may cause tremors, micrography, and the freezing of gait. Although PD is related to the lack of dopamine, the triggering process of its development is not fully understood yet.MethodsIn this work, we introduce convolutional neural networks to learn features from images produced by handwritten dynamics, which capture different information during the individual's assessment. Additionally, we make available a dataset composed of images and signal-based data to foster the research related to computer-aided PD diagnosis.ResultsThe proposed approach was compared against raw data and texture-based descriptors, showing suitable results, mainly in the context of early stage detection, with results nearly to 95%.ConclusionsThe analysis of handwritten dynamics using deep learning techniques showed to be useful for automatic Parkinson's disease identification, as well as it can outperform handcrafted features.



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How do we talk about doctors and drugs? Sentiment analysis in forums expressing opinions for medical domain

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Publication date: Available online 22 April 2018
Source:Artificial Intelligence in Medicine
Author(s): Salud María Jiménez-Zafra, M. Teresa Martín-Valdivia, M. Dolores Molina-González, L. Alfonso Ureña-López
ObjectiveThe main goal of this study is to examine how people express their opinion in medical forums. We analyze the language used in order to determine the best way to tackle sentiment analysis in this domain.MethodsWe have applied supervised learning and lexicon-based sentiment analysis approaches over two different corpora extracted from social web. Specifically, we have focused on two aspects: drugs and doctors. We have selected two forums and we have collected corpora for each one: (i) DOS, a Spanish corpus of drug reviews and (ii) COPOS, a Spanish corpus of patients' opinions about physicians.ResultsThe classification results show that drug reviews are more difficult to classify than those about physicians. In order to understand the difference in the results, we have studied the linguistic features of both corpora.ConclusionsAlthough opinions about physicians and drugs are written in most cases by non-professional users, reviews about physicians are characterized by the use of an informal language while reviews about drugs are characterized by a combination of informal language with specific terminology (e.g. adverse effects, drug names) with greater lexical diversity, making the task of sentiment analysis difficult.



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Transabdominal Breast Augmentation: A Review of 114 Cases Performed over 14 Years

No abstract available

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Reply to the letter: “Breast cleavage remodeling with fat grafting is a safe way to optimize symmetry and to reduce intermammary distance Several questions with regard to the research”

No abstract available

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Re: Clinical and qualitative isokinetic comparison of abdominal morbidity and dynamics following DIEP verses muscle sparing free TRAM flap breast reconstruction

No abstract available

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Textbook of Plastic, Reconstructive, and Aesthetic Surgery – Volume I: Principles and Advances in Plastic Surgery. By Karoon Agrawal and Surajit Bhattacharya. Pp. 614. Thieme Medical Publishers, New Delhi, India, 2017. Price Rs 5,395 ($84.11)

No abstract available

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Immediate Breast Reconstruction with Abdominal Free Flap and Adjuvant Radiotherapy.

No abstract available

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Patient’s breast perception after mastectomy: analysis of outcomes in 208 patients with BREAST-Q following mastectomy alone, implant of tissue expander and definitive breast reconstruction

No abstract available

https://ift.tt/2qQ4rln

“Transabdominal Breast Augmentation: A Review of 114 Cases Performed over 14 Years”

No abstract available

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“Evidence-Based Medicine: Current Evidence in the Diagnosis and Management of Carpal Tunnel Syndrome.”

No abstract available

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Reply to Letter to the Editor on " Transversus Abdominis Plane Blocks with Single-Dose Liposomal Bupivacaine in Conjunction with a Nonnarcotic Pain Regimen Help Reduce Length of Stay Following Abdominally Based Microsurgical Breast Reconstruction

No abstract available

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Spotlight in Plastic Surgery

No abstract available

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Breast cleavage remodeling with fat grafting is a safe way to optimize symmetry and to reduce intermammary distance: Several questions with regard to the research

No abstract available

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“Direct-to-Implant versus Two-Stage Tissue Expander/Implant Reconstruction: 2-Year Risks and Patient-Reported Outcomes from a Prospective, Multicenter Study”

No abstract available

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The Cost of Contralateral Prophylactic Mastectomy in Women with Unilateral Breast Cancer

Background: Contralateral prophylactic mastectomy (CPM) may be unnecessary from an oncologic perspective; therefore, the debate persists about the value of CPM in women with early stage unilateral breast cancer. Given finite healthcare resources, this study aims to evaluate the cost of contralateral prophylactic mastectomy and breast reconstruction. Study Design: Women with unilateral breast cancer undergoing either unilateral mastectomy or unilateral mastectomy with CPM and immediate breast reconstruction (IBR) were selected from the Truven MarketScan databases between 2009 and 2013. Demographic and treatment data were recorded, and over an 18-month follow-up period, the treatment cost was tallied. A log-transformed linear model was used to compare cost between the groups. Results: A total of 2,343 women were identified who met our inclusion criteria with 1,295 undergoing unilateral mastectomy and 1,048 undergoing CPM. Complication rates within 18 months were similar for women undergoing unilateral mastectomy and CPM (39% vs. 42%, p=0.17). Management with unilateral mastectomy with reconstruction required an adjusted cumulative mean cost of $33,557. CPM with reconstruction was an additional $11,872 in expenditure (p

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Sural Nerve Splitting in Reverse Sural Artery Perforator Flap: Anatomical Study in 40 Cadaver Legs

No abstract available

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Evolution in Monitoring of Free Flap Autologous Breast Reconstruction After Nipple-Sparing Mastectomy: Is There a Best Way?

Background: Free flap monitoring in autologous reconstruction after nipple-sparing mastectomy (NSM) remains controversial. We therefore examined outcomes in NSM with buried free flap reconstruction versus free flap reconstruction incorporating a monitoring skin paddle. Methods: Autologous free flap reconstructions with NSM performed from 2006 to 2015 were identified. Demographics and operative results were analyzed and compared between buried flaps and those with a skin paddle for monitoring. Results: 221 free flaps for NSM reconstruction were identified: 50 buried flaps and 171 flaps incorporating a skin paddle. Most common flaps used were deep inferior epigastric perforator (DIEP) (64%), profunda artery perforator (PAP) (12.1%), and muscle-sparing transverse rectus abdominis myocutaneous (MS-TRAM) flaps (10.4%). Autologous reconstructions with a skin paddle had significantly greater BMI (p=0.006). Mastectomy weight (p = 0.017) and flap weight (p

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Aseptic Freeze Dried vs. Sterile Wet-Packaged Human Cadaveric Acellular Dermal Matrix (ADM) in Immediate Tissue Expander Breast Reconstruction: A Propensity Score Analysis Study

Background: Although multiple acellular dermal matrix (ADM) sources exist, it is unclear how ADM processing impacts complication rates. We compared complications between two preparations of human cadaveric ADM (freeze dried [hADM-FD] and ready to use [hADM-RTU]) in immediate tissue expander (TE) breast reconstruction to analyze the effect of processing on complications. HADM-FD is aseptic while hADM-RTU is sterilized and wet-packaged. Methods: We retrospectively reviewed all TE breast reconstructions with hADM-FD or hADM-RTU at a single center between 2006 and 2016. The primary outcome measure was surgical site occurrence (SSO) before implant placement. SSO was defined as: seroma, skin dehiscence, surgical site infection (SSI), or reconstructive failure. The hADM-FD and hADM-RTU groups were compared before and after propensity-score (PS) matching. Results: We included 988 TE reconstructions (53.8% hADM-FD vs. 46.2% hADM-RTU). Analysis of 384 PS-pairs demonstrated a slightly higher rate of SSO (21.4% vs. 16.7%, p=0.10) and SSI (9.6% vs. 7.8%, p=0.13) in the hADM-FD group than hADM-RTU, but the difference was not significant. However, reconstructive failure was significantly higher for hADM-FD versus hADM-RTU (7.8% vs. 4.4%, p=0.050). Conclusions: This is the largest study comparing the outcomes of TE breast reconstruction using hADM materials prepared by different methods. We demonstrated higher early complications with aseptic hADM-FD than sterile hADM-RTU; reconstructive failure was the only outcome to achieve statistical significance. Additionally, there were significantly higher late complications with hADM-RTU compared to hADM-FD. We conclude that ADM preparation has an independent impact on patient outcomes in our comparison of one company's product. Financial Disclosure: Dr. Selber is a consultant for Integra Life Sciences (Plainsboro, NJ). Dr. Hassid is a consultant for Novadaq Technologies, Inc (Bonita Springs, FL). No other author has any disclosures related to this article. Financial Support: This research was supported in part by an Investigator Initiated Research Grant from LifeCell Corporation (Branchburg, NJ). Products mentioned: Alloderm Freeze Dried (LifeCell Corporation, Branchburg, NJ); Alloderm Ready to Use (Lifecell Corporation, Branchburg, NJ). Acknowledgements: The authors wish to acknowledge the Department of Scientific Publications at The University of Texas MD Anderson Cancer Center for review and assistance with this manuscript. Corresponding author: Summer E. Hanson, MD, PhD, Department of Plastic Surgery - Unit 1488, The University of Texas MD Anderson Cancer Center, 1400 Pressler Street, Houston, TX 77030, sehanson@mdanderson.org ©2018American Society of Plastic Surgeons

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The use of surgical delay for partial mastectomy reconstruction in the previously irradiated breast: a matched-control case series

No abstract available

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Supratrochlear Artery Based Periosteal Flaps: A New Alternative Technique for Nasal Lining Reconstruction

No abstract available

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Commentary on: Supratrochlear Artery Based Periosteal Flaps A New Alternative Technique for Nasal Lining Reconstruction

No abstract available

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Adipose Tissue–Preserved Skin Graft: Applicability and Long-Term Results

No abstract available

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Modeling white matter microstructure with fiber ball imaging

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Publication date: 1 August 2018
Source:NeuroImage, Volume 176
Author(s): Emilie T. McKinnon, Joseph A. Helpern, Jens H. Jensen
Fiber ball imaging (FBI) provides a means of calculating the fiber orientation density function (fODF) in white matter from diffusion MRI (dMRI) data obtained over a spherical shell with a b-value of about 4000 s/mm2 or higher. By supplementing this FBI-derived fODF with dMRI data acquired for two lower b-value shells, it is shown that several microstructural parameters may be estimated, including the axonal water fraction (AWF) and the intrinsic intra-axonal diffusivity. This fiber ball white matter (FBWM) modeling method is demonstrated for dMRI data acquired from healthy volunteers, and the results are compared with those of the white matter tract integrity (WMTI) method. Both the AWF and the intra-axonal diffusivity obtained with FBWM are found to be significantly larger than for WMTI, with the FBWM values for the intra-axonal diffusivity being more consistent with recent results obtained using isotropic diffusion weighting. An important practical advantage of FBWM is that the only nonlinear fitting required is the minimization of a cost function with just a single free parameter, which facilitates the implementation of efficient and robust numerical routines.



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Carrying the past to the future: Distinct brain networks underlie individual differences in human spatial working memory capacity

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Publication date: 1 August 2018
Source:NeuroImage, Volume 176
Author(s): Siwei Liu, Jia-Hou Poh, Hui Li Koh, Kwun Kei Ng, Yng Miin Loke, Joseph Kai Wei Lim, Joanna Su Xian Chong, Juan Zhou
Spatial working memory (SWM) relies on the interplay of anatomically separated and interconnected large-scale brain networks. EEG studies often observe load-associated sustained negative activity during SWM retention. Yet, whether and how such sustained negative activity in retention relates to network-specific functional activation/deactivation and relates to individual differences in SWM capacity remain to be elucidated. To cover these gaps, we recorded concurrent EEG-fMRI data in 70 healthy young adults during the Sternberg delayed-match-to-sample SWM task with three memory load levels. To a subset of participants (N = 28) that performed the task properly and had artefact-free fMRI and EEG data, we employed a novel temporo-spatial principal component analysis to derive load-dependent negative slow wave (NSW) from retention-related event-related potentials. The associations between NSW responses with SWM capacity were divergent in the higher (N = 14) and lower (N = 14) SWM capacity groups. Specifically, larger load-related increase in NSW amplitude was associated with greater SWM capacity for the higher capacity group but lower SWM capacity for the lower capacity group. Furthermore, for the higher capacity group, larger NSW amplitude was related to greater activation in bilateral parietal areas of the fronto-parietal network (FPN) and greater deactivation in medial frontal gyrus and posterior mid-cingulate cortex of the default mode network (DMN) during retention. In contrast, the lower capacity group did not show similar pattern. Instead, greater NSW was linked to higher deactivation in right posterior middle temporal gyrus. Our findings shed light on the possible differential EEG-informed neural network mechanism during memory maintenance underlying individual differences in SWM capacity.



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Polymorphic structures phase diagram of shear-induced isotactic polypropylene/carbon fiber cylindrites

Publication date: 15 July 2018
Source:Materials & Design, Volume 150
Author(s): Jing Zhao, Chen Lu, Shuo Guo, Ke Wang, Qiang Fu
Depending on the thermal and mechanical conditions of pulling fiber in the supercooled melts of isotactic polypropylene (iPP), three kinds of cylindrite with variable polymorphic structure could be achieved, i.e., pure α-cylindrite, mixed α/β cylindrite, and β-rich cylindrite. However, precisely assessing the synergic action of thermal and mechanical factors on polymorphic structure of cylindrite is still challenging. Thanks to the great convenience of temperature gradient (T-g) technique in surveying structural transitions arisen from temperature variation, a crystallization temperature (Tc)-pulling rate (Rpull) dependent phase diagram of polymorphs in iPP/carbon fiber (CF) cylindrite was achieved readily through adopting different Rpulls. It was intriguing to suggest that (1) the temperature regime of mixed α/β cylindrite became narrower and narrower as increasing Rpull, implying a sudden transition from β-polymorph to α-polymorph upon intensive shearing; and (2) the upper threshold temperature that allowing generation of β fan-shaped domain was independent on Rpull, around 145 °C. Moreover, the structural difference between mixed α/β cylindrite and β-rich cylindrite was revealed in detail by scanning electron microscopy. An approximately regular nucleation line of β-form appeared in β-rich cylindrite, due to prevailing α-to-β bifurcation arisen from the edge-on α-lamellae. Whereas, occasional α/β bifurcation was found among a tremendous number of α-lamellae within the mixed α/β regime. Constructing the polymorphs phase diagram is of significance in manipulation of interfacial crystallization entities and fabrication of fiber-reinforced semi-crystalline polymers with high performances.Brief abstractIn this study, the combined effect of crystallization temperature (Tc) and pulling rate (Rpull) on the polymorphic structure of shear-induced cylindrite in isotactic polypropylene (iPP)/carbon fiber (CF) composite was well ascertained by using the T-g field technique. It was found that reducing Tc or improving Rpull might induce the transformations of polymorphism from pure α-cylindrite to mixed α/β cylindrite up to β-rich cylindrite. A crystallization temperature (Tc)-pulling rate (Rpull) dependent phase diagram of polymorphs in iPP/CF cylindrite was achieved readily. It was intriguing to suggest that (1) the temperature regime of mixed α/β cylindrite became narrower and narrower as increasing Rpull, implying a sudden transition from β-polymorph to α-polymorph upon intensive shearing; and (2) the upper threshold temperature that allowing generation of β fan-shaped domain was independent on Rpull, around 145 °C. The findings of this study are meaningful for construction of appropriate interfacially-crystallized structure, which could efficiently induce interfacial enhancement in polymer/fiber composites.

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Surface plasmon resonance aided analysis of quantum wells for photonic device applications

Publication date: 15 July 2018
Source:Materials & Design, Volume 150
Author(s): Sheetal Dewan, Ayushi Paliwal, Monika Tomar, Ashok K. Kapoor, R.P. Tandon, Vinay Gupta
The present report aims at analyzing the quantum well (QW) structures using the highly sensitive surface plasmon resonance (SPR) technique in Otto configuration. The optical properties of ZnO and Ni doped ZnO (NiZnO) based QW structures grown using Pulsed laser deposition technique are investigated. An optimal value of QW width (8nm) is deduced from the SPR study for maximum charge carrier confinement which is in coherence with the photoluminescence (PL) studies conducted on the same QW structures. The metal-dielectric interfaces were modelled primarily for the design of QW structures to be analysed experimentally. The mechanism behind the coupling of QWs with SP excitation has been proposed theoretically and experimentally to substantiate the results of PL and SPR studies. The variation in the SPR curves observed as a function of the QW width can be attributed to the interaction of evanescent SP field originating at the Au/QW interface and electroabsorptive behaviour of QWs towards the SP field.



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Interfacial bonding during multi-material fused deposition modeling (FDM) process due to inter-molecular diffusion

Publication date: 15 July 2018
Source:Materials & Design, Volume 150
Author(s): Jun Yin, Chaohua Lu, Jianzhong Fu, Yong Huang, Yixiong Zheng
Multi-material fused deposition modeling (FDM) is an effective tool to realize the optimal design and manufacturing with various materials, but how to achieve an adequate level of interfacial bonding strength between dissimilar materials is still a critical problem. Herein, the influence of three multi-material FDM processing parameters, i.e. nozzle temperature, building stage temperature and printing speed, on the interfacial bonding strength of thermoplastic polyurethane (TPU)/acrylonitrile butadiene styrene (ABS) bi-material structures was experimentally investigated. It was found that the interfacial bonding strength was significantly improved from 0.86 to 1.66 MPa (increased by 93%) when the building stage temperature increased from 30 to 68 °C, which was the most effective processing parameter. Then, a heat transfer-based polymer inter-molecular diffusion theory was developed to understand the interfacial bonding mechanism. The interfacial temperature profiles during multi-material FDM process were experimentally measured by inserting thermocouples into printing specimens, and the theoretical model was well validated due to the good agreement between experimental and numerical data of interfacial temperature and bonding strength. The model provided an accurate prediction of interfacial bonding strength based on the understanding of thermally-driven diffusion of multi-material filaments; which would help improving the mechanical properties of products fabricated by multi-material FDM.

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Optimising in-situ nitridation in piled aluminium flakes for novel closed cell composites with high fracture stress and toughness

Publication date: 15 July 2018
Source:Materials & Design, Volume 150
Author(s): Andrey A. Chernousov, Ben Y.B. Chan
Modified aluminium foams, such as syntactic aluminium foams (SAFs) that contain tiny ceramic hollow spheres, are widely used for the protection of modern lightweight vehicles in mechanical impacts. Due to the typical compromises between strength and toughness, conventional SAFs absorb <5 J g−1 of mechanical energy before fracture.In this study, we demonstrate that a nacre-like structure of piled aluminium flakes with in-situ grown AlN layers can provide a specific toughness of up to ~50 J g−1. At the optimum toughness, the compressive yield strength σ0.2%, fracture strength σT and strain εT reach ≈110 MPa, 481 MPa and 0.35, respectively. The improved properties originate from the efficient nitridation-driven spreading of the partially melted Al of the flakes through the permeable nitride layers. In an N2 atmosphere at about 833 K, an optimal composite structure is formed with a porosity ϕE and AlN volume fraction vAlN of 0.26 and 0.12, respectively. The pre- and post-optimal annealing temperatures lead to a relatively small area of Al-AlN bonding, as a result of overgrowth and undergrowth of the AlN surfaces, respectively.This straightforward technology offers an affordable way to produce novel lightweight composites for state-of-the-art protection of vehicles and dynamic machinery in many industrial areas.

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A new approach to rapidly generate random periodic representative volume elements for microstructural assessment of high volume fraction composites

Publication date: 15 July 2018
Source:Materials & Design, Volume 150
Author(s): Geng Li, Farzad Sharifpour, Aram Bahmani, John Montesano
An algorithm based on event-driven molecular dynamics theory was developed to rapidly generate periodic representative volume elements (RVEs) with nonuniform distributions for both unidirectional fibre-reinforced and spherical particle-reinforced composites. Detailed statistical analyses were conducted for assessing the ability to generate RVEs with nonuniformly dispersed microstructures and either constant or random inclusion sizes for a wide range of volume fractions. The generated microstructures were directly compared with available microstructural optical images of a composite material, showing excellent statistical correlation and providing validation for the developed RVE generation approach. For further validation, finite element analysis was conducted using the generated RVEs in order to evaluate volume averaged elastic constants. The expected isotropic characteristics of the RVEs were correctly calculated, and excellent correlations with experimental data from the literature provided additional support for the algorithm accuracy. The versatile algorithm can rapidly generate RVEs with realistic reinforcement dispersions and high volume fractions up to 80%, which is advantageous compared to other algorithms. The proposed algorithm can be used as a design tool to accurately evaluate and tailor the mechanical properties of distinct composite material systems, and for their microstructural assessment including local damage predictions.

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The role of defects and critical pore size analysis in the fatigue response of additively manufactured IN718 via crystal plasticity

Publication date: 15 July 2018
Source:Materials & Design, Volume 150
Author(s): Veerappan Prithivirajan, Michael D. Sangid
The inherent defects associated with materials produced by selective laser melting (SLM) limits their usage in safety-critical applications. In our work, a crystal plasticity (CP) based framework is developed to identify the critical porosity characteristics, which quantifies the limiting scenarios of fatigue crack initiation at a pore rather than the crystallographic features. 3D virtual microstructures are developed based on the characterization of SLM IN718 for use in the CP simulations. Damage indicator parameters, such as the plastic strain accumulation, elastic stress anisotropy, resolved shear stress and triaxiality, obtained from the CP simulations are used to identify the most probable locations of crack initiation. Pores are explicitly added to the microstructure instantiations in a systematic manner by varying the size, location, and proximity between pores. The critical pore size is defined as the size beyond which the location of crack nucleation transitions from crystallographic features to the pore vicinity, which is determined to be 20 μm in the material of interest with an average grain size of 48 μm. This work is beneficial in qualifying SLM materials given the natural porosity inherent to the manufacturing process, by reducing the number of fatigue experiments.

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Mechanisms of WC plastic deformation in cemented carbide

Publication date: 15 July 2018
Source:Materials & Design, Volume 150
Author(s): Xuemei Liu, Jianlong Zhang, Chao Hou, Haibin Wang, Xiaoyan Song, Zuoren Nie
The WC-Co cemented carbides with ultracoarse and ultrafine grain structures were tested by the bonded interface technique to investigate the deformation behaviour of WC. The electron backscattering diffraction assisted trace analysis and transmission electron microscopy were combined to examine the microstructural details in the deformation region. It was found that the plastic characteristics of the ultracoarse WC originate from both the prismatic (e.g. {101¯0} ⟨1¯21¯3⟩) and pyramidal (e.g. {01¯11} ⟨01¯10⟩) slip systems. The deformation mechanisms of the ultracoarse and ultrafine cemented carbides were compared. It was proposed that different from the ultrafine cemented carbides in which the plastic deformation is mainly attributed to the metal binder, the dislocations and stacking faults in WC make significant contributions to the plastic deformation hence the fracture toughness of the ultracoarse cemented carbide.

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High temperature thermodynamics of spinodal decomposition in arc deposited TixNbyAlzN coatings

Publication date: 15 July 2018
Source:Materials & Design, Volume 150
Author(s): F. Tasnádi, L. Rogström, J. Zhu, F. Wang, T.-W. Hsu, H. Lind, I.A. Abrikosov, M.P. Johansson-Jõesaar, M. Odén
Using first principles calculations and experimental methods we show that B1 structured solid solution TixNbyAlzN can be grown. The mixing free energy surface indicates that the alloys should decompose. Theoretical analysis of the thermodynamic driving force towards the spinodal decomposition shows that the force can be different in alloys with equally low thermodynamic stability but different Nb content, indicating that the detailed picture of the decomposition should also be different. Electron microscopy and nanoindentation underlines different age hardening of the samples. We demonstrate that an alloy with the optimized composition, Ti0.42Nb0.17Al0.41N combines high thermal stability and age hardening behavior.

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Mechanism of heat affected zone cracking in Ni-based superalloy DZ125L fabricated by laser 3D printing technique

Publication date: 15 July 2018
Source:Materials & Design, Volume 150
Author(s): Yao Li, Kai Chen, Nobumichi Tamura
Laser 3D printing is a promising technique to repair damaged Ni-based superalloy components. However, the occurrence of heat affected zone (HAZ) cracking severely limits its applicability. Here we unravel the cracking mechanism by studying the element, phase, defect, and strain distribution around an intergranular crack that initiated from the primary HAZ. Using synchrotron X-ray Laue microdiffraction, we measured high tensile strain/stress transverse to the building direction in both the primary HAZ and the cladding layers, as well as high-density dislocations, which resulted from the thermal contraction and rapid precipitation of γ′ phase. The crack initiated because the transverse tensile strain/stress tore up the liquid film formed by the low-melting point preexisting phases in the primary HAZ, such as γ/γ′ eutectics and coarse γ′ precipitates. The incoherent carbide particles were frequently observed near the crack root as local strain concentrators. In the cladding layers, micro-segregation could not be completely avoided, thus the hot crack continued to propagate over several layers with the assistance of the transverse tensile stress. Our investigations provide a useful guideline for the optimization of the 3D printing process to repair Ni-based superalloys with high susceptibility to hot cracking.

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Inkjet printed polyethylene glycol as a fugitive ink for the fabrication of flexible microfluidic systems

Publication date: 15 July 2018
Source:Materials & Design, Volume 150
Author(s): Ahmed Alfadhel, Jing Ouyang, Chaitanya G. Mahajan, Farzad Forouzandeh, Denis Cormier, David A. Borkholder
This paper demonstrates a novel and simple processing technique for the realization of scalable and flexible microfluidic microsystems by inkjet-printing polyethylene-glycol (PEG) as a sacrificial template, followed by embedding in a structural layer (e.g. soft elastomers). The printing technology allows production of an array of PEG droplets simultaneously, reducing cost and manufacturing time. The PEG can be removed through heating above its phase-change temperature after the formation of the structural layer, with hydraulic flow removing the material. The developed technique allows easy modulation of the shape and dimensions of the pattern with the ability to generate complex architectures without using lithography. The method produces robust planar and multilayer microfluidic structures that can be realized on wide range of substrates. Moreover, microfluidics can be realized on other systems (e.g. electrodes and transducers) directly without requiring any bonding or assembling steps, which often limit the materials selection in conventional microfluidic fabrication. Multilayer Polydimethylsiloxane (PDMS) microfluidic channels were created using this technique to demonstrate the capability of the concept to realize flexible microfluidic electronics, drug delivery systems, and lab-on-a-chip devices. By utilizing conductive liquid metals (i.e. EGaIn) as the filling material of the channels, flexible passive resistive components and sensors have been realized.

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Editorial Board

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Publication date: June 2018
Source:Medical Hypotheses, Volume 115





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Tracking single membrane targets of human autoantibodies using single nanoparticle imaging

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Publication date: Available online 21 April 2018
Source:Journal of Neuroscience Methods
Author(s): Julie Jézéquel, Julien P. Dupuis, François Maingret, Laurent Groc
BackgroundOver the past decade, an increasing number of neurological and neuropsychiatric diseases have been associated with the expression of autoantibodies directed against neuronal targets, including neurotransmitter receptors. Although cell-based assays are routinely used in clinics to detect the presence of immunoglobulins, such tests often provide heterogeneous outcomes due to their limited sensitivity, especially at low titers. Thus, there is an urging need for new methods allowing the detection of autoantibodies in seropositive patients that cannot always be clinically distinguished from seronegative ones.New MethodHere we make a case for single nanoparticle imaging approaches as a highly sensitive antibody detection assay. Through high-affinity interactions between functionalized nanoparticles and autoantibodies that recognize extracellular domains of membrane neuronal targets, single nanoparticle imaging allows a live surface staining of transmembrane proteins and gives access to their surface dynamics.Results and Comparison with Existing Method(s)We show here that this method is well-suited to detect low titers of purified immunoglobulin G (IgG) from first-episode psychotic patients and demonstrate that these IgG target glutamatergic N-Methyl-D-Aspartate receptors (NMDAR) in live hippocampal neurons. The molecular behaviors of targeted membrane receptors were indistinguishable from those of endogenous GluN1 NMDAR subunit and were virtually independent of the IgG concentration present in the sample contrary to classical cell-based assays.ConclusionsSingle nanoparticle imaging emerges as a real-time sensitive method to detect IgG directed against neuronal surface proteins, which could be used as an additional step to rule out ambiguous seropositivity diagnoses.



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A comparison of seven different dti-derived estimates of corticospinal tract structural characteristics in chronic stroke survivors

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Publication date: Available online 21 April 2018
Source:Journal of Neuroscience Methods
Author(s): Bokkyu Kim, Beth E. Fisher, Nicolas Schweighofer, Richard M. Leahy, Justin P. Haldar, Soyoung Choi, Dorsa B. Kay, James Gordon, Carolee J. Winstein
BackgroundDifferent diffusion tensor imaging (DTI) has been used to estimate corticospinal tract (CST) structure in the context of stroke rehabilitation research. However, there is no gold standard for the estimate of CST structure in chronic stroke survivors. This study aims to determine the most accurate DTI-derived CST estimate that is associated with a clinical motor outcome measure.MethodsWe obtained imaging and behavioral data from a phase-I stroke rehabilitation clinical trial. We included thirty seven chronic stroke survivors with mild­to­moderate motor impairment. Imaging data were processed using BrainSuite16a software. We calculated mean FA for each of 7 different ROIs/VOIs that include manually drawn 2-D ROIs and 3-D VOIs of CST from individual tractography or standard atlas. We compared ipsi- and contralesional CST FA for each method. Partial correlation was conducted between each CST FA asymmetry index and a time-based motor outcome measure, controlling for age and chronicity.ResultsIpsilesional CST FA was significantly lower than contralesional CST FA for each of the 7 methods Only CST FA asymmetry from the 3-D individual CST tractography showed a significant correlation with the primary motor outcome (r = 0.46, p = .005), while CST FA from the other six methods did not.Comparison with existing methodsCompared to the six other methods, CST FA asymmetry from 3-D individual tractography is the most accurate estimate of CST structure in this cohort of stroke survivors.ConclusionWe recommend this method for future research seeking to understand brain-behavior mechanisms of motor recovery in chronic stroke survivors.



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Tumor necrosis factor α‐308 G/A and interleukin 1 β‐511 C/T gene polymorphisms in patients with scarring acne

Journal of Cosmetic Dermatology, EarlyView.


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Nerve entrapment syndromes in dermatology: Review and practical approach to treatment

Australasian Journal of Dermatology, EarlyView.


https://ift.tt/2F7Pcs7

Oral lichenoid drug eruption in association with drinking tonic water

Australasian Journal of Dermatology, EarlyView.


https://ift.tt/2K4wfug

Dermoscopic features in two cases of acroangiodermatitis

Australasian Journal of Dermatology, EarlyView.


https://ift.tt/2F6KrPJ

Acute‐onset, painful acral granuloma annulare with unusual microcalcification

Australasian Journal of Dermatology, EarlyView.


https://ift.tt/2K4wci4

Report from the fifth international consensus meeting to harmonize core outcome measures for atopic eczema/dermatitis clinical trials (HOME initiative)

British Journal of Dermatology, EarlyView.


https://ift.tt/2F6CB8N

Issue Information

British Journal of Dermatology, Volume 178, Issue 4, Page i-v, April 2018.


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Stress and more stress: the importance in skin disease of worrying about what others think

British Journal of Dermatology, Volume 178, Issue 4, Page 821-822, April 2018.


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A comprehensive approach to evaluating and classifying sun‐protective clothing

British Journal of Dermatology, Volume 178, Issue 4, Page e299-e299, April 2018.


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A pleiotropic effect of the APOE gene: association of APOE polymorphisms with multibacillary leprosy in Han Chinese from Southwest China

British Journal of Dermatology, Volume 178, Issue 4, Page e300-e300, April 2018.


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Core outcome sets in dermatology: report from the second meeting of the International Cochrane Skin Group Core Outcome Set Initiative

British Journal of Dermatology, Volume 178, Issue 4, Page e297-e297, April 2018.


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HLA‐Cw6和银屑病

British Journal of Dermatology, Volume 178, Issue 4, Page e320-e320, April 2018.


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Herbal interventions: make the grass greener!

British Journal of Dermatology, Volume 178, Issue 4, Page 827-829, April 2018.


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Long‐term management of moderate‐to‐severe atopic dermatitis with dupilumab and concomitant topical corticosteroids (LIBERTY AD CHRONOS): a critical appraisal

British Journal of Dermatology, Volume 178, Issue 4, Page e311-e311, April 2018.


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Association of APOE polymorphisms with multibacillary leprosy

British Journal of Dermatology, Volume 178, Issue 4, Page 833-834, April 2018.


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Photodynamic therapy is more effective than imiquimod for actinic keratosis in organ transplant recipients: a randomized intraindividual controlled trial

British Journal of Dermatology, Volume 178, Issue 4, Page e298-e298, April 2018.


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A platinum era for dermatology therapeutics?

British Journal of Dermatology, Volume 178, Issue 4, Page 836-837, April 2018.


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Image Gallery: Brimonidine gel for facial erythema in Netherton syndrome

British Journal of Dermatology, Volume 178, Issue 4, Page e277-e277, April 2018.


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Atopic dermatitis: risk estimates for hand eczema

British Journal of Dermatology, Volume 178, Issue 4, Page 827-827, April 2018.


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Use of the hCONSORT criteria as a reporting standard for herbal interventions for common dermatoses: a systematic review

British Journal of Dermatology, Volume 178, Issue 4, Page e310-e310, April 2018.


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The Garment Protection Factor: further advances in labelling sun‐protective clothing

British Journal of Dermatology, Volume 178, Issue 4, Page 835-836, April 2018.


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对于患有光化性角化病的器官移植受者来说,光动力疗法比咪喹莫特更加有效:一项随机个体对照试验

British Journal of Dermatology, Volume 178, Issue 4, Page e313-e313, April 2018.


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Defining the psychological comorbidity in vitiligo: systematically casting the net wide

British Journal of Dermatology, Volume 178, Issue 4, Page 826-826, April 2018.


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Stress and skin disease quality of life: the moderating role of anxiety sensitivity social concerns

British Journal of Dermatology, Volume 178, Issue 4, Page e304-e304, April 2018.


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HLA‐C*06 and psoriasis: susceptibility, phenotype, course and response to treatment

British Journal of Dermatology, Volume 178, Issue 4, Page 825-825, April 2018.


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Differences in fundamental and functional properties of HPMC co-processed fillers prepared by fluid-bed coating and spray drying

Publication date: 1 July 2018
Source:European Journal of Pharmaceutical Sciences, Volume 119
Author(s): QianQian Dong, MiaoMiao Zhou, Xiao Lin, Lan Shen, Yi Feng
This study aimed to develop novel co-processed tablet fillers based on the principle of particle engineering for direct compaction and to compare the characteristics of co-processed products obtained by fluid-bed coating and co-spray drying, respectively. Water-soluble mannitol and water-insoluble calcium carbonate were selected as representative fillers for this study. Hydroxypropyl methylcellulose (HPMC), serving as a surface property modifier, was distributed on the surface of primary filler particles via the two co-processing methods. Both fundamental and functional properties of the products were comparatively investigated. The results showed that functional properties of the fillers, like flowability, compactibility, and drug-loading capacity, were effectively improved by both co-processing methods. However, fluid-bed coating showed greater advantages over co-spray drying in some aspects, which was mainly attributed to the remarkable differences in some fundamental properties of co-processed powders, like particle size, surface topology, and particle structure. For example, the more irregular surface and porous structure induced by fluid-bed coating could contribute to better compaction properties and lower lubricant sensitivity due to the increasing contact area and mechanical interlocking between particles under pressure. More effective surface distribution of HPMC during fluid-bed coating was also a contributor. In addition, such a porous agglomerate structure could also reduce the separation of drug and excipients after mixing, resulting in the improvement in drug loading capacity and tablet uniformity. In summary, fluid-bed coating appears to be more promising for co-processing than spray drying in some aspects, and co-processed excipients produced by it have a great prospect for further investigations and development.

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Liposomal CpG-ODN: An in vitro and in vivo study on macrophage subtypes responses, biodistribution and subsequent therapeutic efficacy in mice models of cancers

Publication date: 1 July 2018
Source:European Journal of Pharmaceutical Sciences, Volume 119
Author(s): Sara Nikoofal-Sahlabadi, Maryam Matbou Riahi, Kayvan Sadri, Ali Badiee, Amin Reza Nikpoor, Mahmoud Reza Jaafari
CpG oligodeoxynucleotides (CpG-ODN), a common immune stimulator and vaccine adjuvant, was reported to switch Tumor Associated Macrophages (TAMs) from M2 to M1 phenotype inducing anti-tumor responses. Liposomes are of the successfully applied carriers for CpG-ODN. The aim of present study was design and preparation of a liposomal formulation containing phosphodiester CpG-ODN, evaluation of its effect on macrophages responses, and subsequent antitumor responses in mice. Liposomal formulations containing phosphodiester CpG-ODN or non-CpG-ODN were prepared and characterized. MTT reduction assay in four different cell lines, uptake, arginase and iNOS activity evaluation in macrophage cell lines, biodistribution study and therapeutic anti-tumor effects of formulations in mice bearing C26 colon carcinoma or B16F0 melanoma were carried out. The size of liposomes containing CpG-ODN was ~200 nm with the encapsulation efficiency of 33%. The iNOS activity assay showed high nitric oxide (NO) level in M2 phenotype of macrophage cell lines treated by liposomes containing CpG-ODN. In mice which received liposomes containing CpG-ODN as a monotherapy, maximum tumor growth delay with remarkable survival improvement was observed compared to control groups. Biodistribution study showed the accumulation of liposomal formulation in tumor micro-environment. In conclusion, considerable anti-tumor responses observed by liposomes containing CpG-ODN was due to enhanced delivery of CpG-ODN to immune cells and subsequent initiation of anti-tumoral immune responses.

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Additive potential of combination therapy against cryptococcosis employing a novel amphotericin B and fluconazole loaded dual delivery system

Publication date: 1 July 2018
Source:European Journal of Pharmaceutical Sciences, Volume 119
Author(s): Azmat Ali Khan, Amer M. Alanazi, Mumtaz Jabeen, Shahanavaj Khan, Abdul Malik
Cryptococcus neoformans is one of the most lethal fungi causing mortality across the globe. Immuno-competent patients and patients taking immuno-suppressive medications are extremely susceptible to its infection. For effective removal of cryptococcal burden, there is an urgent need for new forms of therapy. In the present study, we have explored the potential effects of amphotericin B (AMB) and fluconazole (FLC) in combination, against cryptococcosis in Swiss albino mice. To enhance the therapeutic potential of the tested drugs, they were entrapped into fibrin microspheres; a dual delivery vehicle comprising of poly-lactide co-glycolide (PLGA) microsphere that was additionally encapsulated into the fibrin cross-linked plasma bead. Dynamics of fibrin microspheres included survival and fungal burden in lung, liver and spleen of treated mice. While each drug was effective in combination or alone, prominent additive potential of AMB and FLC were clearly observed when used in fibrin microsphere. Significant reduction in fungal burden and increase in survival rate of AMB + FLC-fibrin microspheres treated mice shows an extensive accessibility of both tested drugs without any side-effects. A full potential of two-drug combination encapsulated in fibrin microspheres proposes an effective approach of safe delivery to the target site in their intact form and decrease the drug associated toxicities.

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Coumestrol/hydroxypropyl-β-cyclodextrin association incorporated in hydroxypropyl methylcellulose hydrogel exhibits wound healing effect: in vitro and in vivo study

Publication date: 1 July 2018
Source:European Journal of Pharmaceutical Sciences, Volume 119
Author(s): Sara E. Bianchi, Barbara E.K. Machado, Marília G.C. da Silva, Michelle M.A. da Silva, Lidiane Dal Bosco, Magno S. Marques, Ana P. Horn, Lara Persich, Fabiana C. Geller, Débora Argenta, Helder F. Teixeira, Cláudia M.O. Simões, Cristiana L. Dora, Valquíria L. Bassani
Several beneficial effects on the skin have been reported for coumestrol (COU), such as protection against photoaging and improvement of skin elasticity and thickness in postmenopausal women. However no reports on the effect of COU on wound healing were found. Nevertheless, COU has low aqueous solubility, which is a crucial limitation for biological tests. The present study was designed as a two-step experiment to evaluate the wound healing effect of COU. First, we used fibroblasts and the experimental in vitro artificial wound model, scratch assay, to compare the effects of COU free, dissolved in dimethyl sulfoxide (DMSO) or Dulbecco's modified Eagle's medium (DMEM), or associated with hydroxypropyl-β-cyclodextrin (HPβCD). The 50 μM (66.1%) and 10 μM (56.3%) COU/HPβCD association induced cell proliferation and migration in inflicted wounds. Subsequently, the in vivo wound healing experimental model (Wistar rats) revealed that COU/HPβCD incorporated into hypromellose (HPMC) hydrogel had similar efficacy in wound healing in comparison to the positive control (Dersani®), with the advantage that 50% wound healing was achieved within a shorter period. In summary, the results successfully demonstrated, for the first time, the wound healing effect of COU/HPβCD incorporated into HPMC hydrogel and describe the feasibility of the biological tests with the use of HPβCD instead DMSO.

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FAK- and YAP/TAZ dependent mechanotransduction pathways are required for enhanced immunomodulatory properties of adipose-derived mesenchymal stem cells induced by aligned fibrous scaffolds

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Publication date: July 2018
Source:Biomaterials, Volume 171
Author(s): S. Wan, X. Fu, Y. Ji, M. Li, X. Shi, Y. Wang
Adipose-derived mesenchymal stem cells (ASCs) represent an excellent candidate for tissue engineering due to their multipotency and paracrine functions. Physical cues provided by the scaffolds have been shown to direct a variety of cellular behaviors of ASCs; however, their effects on the paracrine functions of ASCs, especially immunomodulatory functions, remain largely unexplored. Thus, PLLA electrospun fibrous scaffolds, with fibers oriented either randomly or aligned, were used as a model to investigate the effects of fiber orientation on the immunomodulatory paracrine secretion of ASCs. ASCs cultured on aligned fibers produced significantly higher levels of immunomodulatory factors than those cultured on random fibers. By using the conditioned media from ASCs cultured on aligned fibers, the enhanced immunomodulatory functions of ASCs were confirmed by the M2 phenotypic change seen in macrophages. The enhanced immunomodulation of ASCs correlated with the activation of FAK signaling, as evidenced by a decreased production of immunomodulatory factors in ASCs after treatment with inhibitors of the FAK pathway. In addition, aligned fibers promoted the activation of YAP signaling in ASCs. The inhibited immunomodulatory properties of ASCs by a YAP inhibitor indicated that YAP signaling was also involved in mediating the increased immunomodulatory functions of ASCs on aligned fibers. Our findings identify both FAK and YAP/TAZ signaling as required mechanotransduction pathways through which aligned fibers stimulate the immunomodulatory function of ASCs and highlight fiber orientation as a key design parameter for immunomodulatory fibrous engineered scaffolds.



https://ift.tt/2K3z9zv

Fabrication of nanofibrous microcarriers mimicking extracellular matrix for functional microtissue formation and cartilage regeneration

Publication date: July 2018
Source:Biomaterials, Volume 171
Author(s): Yansen Wang, Xueling Yuan, Kun Yu, Haoye Meng, Yudong Zheng, Jiang Peng, Shibi Lu, Xiaotong Liu, Yajie Xie, Kun Qiao
Cartilage has rather limited capacities for self-repair and regeneration. To repair complexly shaped cartilage tissue defects, we propose the application of microtissues fabricated from bone marrow-derived mesenchymal stem cells (BMSCs) cultured in natural bionic nanofibrous microcarriers (NF-MCs). The NF-MCs were structurally and functionally designed to mimic natural extracellular matrix (ECM) by crosslinking dialdehyde bacterial cellulose (DBC) with DL-allo-hydroxylysine (DHYL) and complexing chitosan (CS) with DHYL through electrostatic interactions. The orthogonal design allows for fine tuning of fiber diameter, pore size, porosity, mechanical properties, and biodegradation rate of the NF-MC. BMSCs cultured in NF-MCs showed improved proliferation compared with those cultured in chitosan microcarriers (CS-MCs). After three-week culture under microgravity conditions, functional cartilage microtissues were generated. When implanted into a knee articular cartilage defect in mice, the microtissue showed superior in vivo cartilage repair as characterized by cell tracking, histology, micro CT image, and gait analysis. Versatile in natural biopolymer design and biomimetic in nanofibrous component embedded in macroporous microcarriers, these injectable NC-MCs demonstrate to be effective carriers for cell proliferation and differentiation. Furthermore, the functional microtissues also show their prospect in repair of cartilage tissue, and suggest their potential for other tissues in general.

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Comparing ex vivo and in vitro translocation of silver nanoparticles and ions through human nasal epithelium

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Publication date: July 2018
Source:Biomaterials, Volume 171
Author(s): Jonathan L. Falconer, Jeremiah A. Alt, David W. Grainger
Silver nanomaterials are widely used in clinically approved devices, consumer goods, and over-the-counter nutraceutical products. Despite the increase in silver nanomaterial research, few investigations have specifically distinguished the biological effects resulting from silver nanoparticles (AgNPs) versus silver ions released from AgNPs. This is in part, due to the complex analytical methods required to characterize silver ion release from AgNPs in biological media. This study sought to analyze silver ion release from AgNPs in biological media, compare silver transport from soluble AgNO3 and AgNPs through ex vivo full thickness sinus human tissue explants and human nasal epithelium and determine fractional AgNP internalization by human nasal epithelial cells. Rapid silver ion release is observed from AgNPs in human nasal epithelial cell medium over 3 h (9.6% of total silver mass). Significantly lower translocation of AgNPs is observed through human nasal epithelial cell monolayers and ex vivo human sinus tissue explants compared to silver ion (AgNO3). AgNP internalization is directly observed in AgNP-exposed human nasal epithelial cell monolayers by live cell scanning transmission electron microscopy (STEM), providing one potential mechanism for AgNP transcytosis. However, in vitro AgNP dissolution experiments suggest that silver in human nasal epithelium is primarily silver ion. Ionic AgNO3 produces significantly higher silver translocation, supporting previous results claiming silver ion as primarily responsible for biological effects of AgNPs.



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Porcine epidemic diarrhea vaccine efficacy evaluation by vaccination timing and frequencies

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Publication date: 11 May 2018
Source:Vaccine, Volume 36, Issue 20
Author(s): Jung-Eun Park, Hyun-Jin Shin
Porcine epidemic diarrhea (PED) virus is a causative agent of enteric disease characterized by watery diarrhea and dehydration. Because PED has high morbidity and mortality, especially in suckling piglets, it causes a great economic loss to swine farms worldwide. Although various PED vaccines have been developed and commercialized, their efficacies are still controversial. In particular, current PED vaccination protocol (vaccination at 2 and 4 weeks before farrowing) may cause stress in pregnant sows. In this study, we compared the effects of PED vaccination timing and frequency for its efficacy by measuring the PED virus-specific antibodies. We found that vaccination at early stages of pregnancy induces similar levels of serum and colostrum antibodies with those at late stages of pregnancy. As the number of vaccinations increased, the amounts of antibody in serum and colostrum, and neutralizing activities increased. Our results provide important information for establishing a more efficient PED vaccination protocol.



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Is varicella vaccination associated with pediatric arterial ischemic stroke? A population-based cohort study

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Publication date: 11 May 2018
Source:Vaccine, Volume 36, Issue 20
Author(s): Shannon E. MacDonald, Douglas C. Dover, Michael D. Hill, Adam Kirton, Kimberley A. Simmonds, Lawrence W. Svenson
Background and purpose: Varicella disease is a risk factor for pediatric Arterial Ischemic Stroke (AIS). Isolated case reports have emerged suggesting that varicella vaccination may also pose a risk for AIS. Methods: This retrospective population-based cohort study assessed the risk of AIS in children who received a varicella-containing vaccine, as compared to those who did not. The study cohort consisted of children born between January 1, 2006 and December 31, 2013, in the Canadian province of Alberta, where all routine childhood vaccinations are publicly-funded, and recorded in a central immunization repository. These data were linked with hospital discharge abstract data to identify children diagnosed with AIS. A Cox proportional hazard model assessed the risk of AIS in the 12 months following vaccination for children receiving a varicella vaccine between 11 and 23 months of age, as compared to non-vaccinated children. Results: Of the 368,992 children in the cohort, 325,729 were vaccinated with a varicella-containing vaccine between 11 and 23 months of age. The rate of AIS was 7.8 (95% CI 4.8–10.9) per 100,000 person years at risk in the 12 months following varicella vaccination, as compared to 6.8 (95% CI 1.3–12.2) for children who did not receive a varicella vaccine. The adjusted Hazard Ratio for the risk of AIS, controlling for other AIS risk factors, in vaccinated children as compared to non-vaccinated children was 1.6 (95% CI 0.7–3.7) in the 12 months following vaccination and 1.7 (95% CI 0.5–4.9) in the 30 days following vaccination. Conclusions: Our study found no evidence of an increased risk of AIS following varicella vaccination. This population-based cohort study provides reassurance to parents and clinicians regarding the safety of varicella vaccination.



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