|
Τρίτη 28 Μαρτίου 2017
Scholar : These new articles for Text and Performance Quarterly are available online
Effect of two isolated vocal facilitating techniques Glottal Fry and Yawn-Sigh on the phonation of female speech-language pathology students: A pilot study
Source:Journal of Communication Disorders
Author(s): I. Meerschman, E. Dhaeseleer, T. Catry, B. Ruigrok, S. Claeys, K. Van Lierde
ObjectiveThe purpose of this study was to determine the effect of two isolated vocal facilitating techniques, glottal fry and yawn-sigh, on the phonation of vocally healthy female speech-language pathology (SLP) students.Study designA multigroup pretest-posttest design was used.MethodsA group of thirty-six healthy female SLP students with a mean age of 18.1 years were assigned into three groups: a glottal fry group (practicing the facilitating technique glottal fry across 18 weeks, n=12), a yawn-sigh group (practicing the facilitating technique yawn-sigh across 18 weeks, n=12) and a control group (receiving no facilitating techniques, n=12). To compare vocal measures before and after this training period, an identical objective voice assessment protocol (maximum performance task, acoustic analysis, voice range profile and Dysphonia Severity Index) was performed in the three groups. Groups were compared over time using linear mixed models. Within-group effects of time were determined using post-hoc pairwise comparisons.ResultsGlottal fry resulted in a significant decrease in lowest and highest intensity. Yawn-sigh resulted in a significant increase in fundamental frequency, a significant decrease in shimmer and noise-to-harmonic ratio, and a significant increase in highest intensity.ConclusionsYawn-sigh may have a positive effect on the phonation of female vocally healthy future SLPs, whereas results are less supportive for using glottal fry in training this population's voice.
http://ift.tt/2ncL5SP
Novel dental adhesive with triple benefits of calcium phosphate recharge, protein-repellent and antibacterial functions
Source:Dental Materials
Author(s): Xianju Xie, Lin Wang, Dan Xing, Ke Zhang, Michael D. Weir, Huaibing Liu, Yuxing Bai, Hockin H.K. Xu
ObjectiveA new adhesive containing nanoparticles of amorphous calcium phosphate (NACP) with calcium (Ca) and phosphate (P) ion rechargeability was recently developed; however, it was not antibacterial. The objectives of this study were to: (1) develop a novel adhesive with triple benefits of Ca and P ion recharge, protein-repellent and antibacterial functions via dimethylaminohexadecyl methacrylate (DMAHDM) and 2-methacryloyloxyethyl phosphorylcholine (MPC); and (2) investigate dentin bond strength, protein adsorption, Ca and P ion concentration, microcosm biofilm response and pH properties.MethodsMPC, DMAHDM and NACP were mixed into a resin consisting of ethoxylated bisphenol A dimethacrylate (EBPADMA), pyromellitic glycerol dimethacrylate (PMGDM), 2-hydroxyethyl methacrylate (HEMA) and bisphenol A glycidyl dimethacrylate (BisGMA). Protein adsorption was measured using a micro bicinchoninic acid method. A human saliva microcosm biofilm model was tested on resins. Colony-forming units (CFU), live/dead assay, metabolic activity, Ca and P ion concentration and biofilm culture medium pH were determined.ResultsThe adhesive with 5% MPC+5% DMAHDM+30% NACP inhibited biofilm growth, reducing biofilm CFU by 4 log, compared to control (p<0.05). Dentin shear bond strengths were similar (p>0.1). Biofilm medium became a Ca and P ion reservoir having ion concentration increasing with NACP filler level. The adhesive with 5% MPC+5% DMAHDM+30% NACP maintained a safe pH>6, while commercial adhesive had a cariogenic pH of 4.SignificanceThe new adhesive with triple benefits of Ca and P ion recharge, protein-repellent and antibacterial functions substantially reduced biofilm growth, reducing biofilm CFU by 4 orders of magnitude, and yielding a much higher pH than commercial adhesive. This novel adhesive is promising to protect tooth structures from biofilm acids. The method of using NACP, MPC and DMAHDM is promising for application to other dental materials to combat caries.
http://ift.tt/2nvOnDS
Growth and accelerated differentiation of mesenchymal stem cells on graphene-oxide-coated titanate with dexamethasone on surface of titanium implants
Publication date: Available online 27 March 2017
Source:Dental Materials
Author(s): Na Ren, Jianhua Li, Jichuan Qiu, Mei Yan, Haiyun Liu, Dandan Ji, Jiadong Huang, Jinghua Yu, Hong Liu
ObjectiveIn this study, the objective is to construct graphene-oxide-coated titanate on titanium foils as drug vehicle to enhance cell proliferation and osteo-differentiation of rat bone mesenchymal stem cells (rBMSCs).MethodsGraphene oxide (GO) sheets obtained using the modified Hummer's method and characterized by AFM were coupled with bioactive titanate on Ti implants (GO-Ti) pretreated by alkali, followed by reduction (rGO-Ti). They were characterized by Raman spectroscopy, XPS, SEM, FTIR and contact angle. After dexamethasone (DEX) was loaded onto them (DEX-GO-Ti and DEX-rGO-Ti), cell proliferation of rBMSCs on them was evaluated by CCK-8 and F-actin staining, and differentiation through alkaline phosphatase activity, mRNA expression, and calcium nodules.ResultsThe obtained GO sheets were monolayers from AFM. Raman spectra exhibited two prominent peaks at D and G bands, and the I(D)/I(G) ratios increased from 0.96 to 1.68 after reduction. XPS proved the existence of oxygenated functional groups for GO-Ti and the reduction of their intensity for rGO-Ti. From SEM, GO and rGO were evenly coated on nanostructures. DEX-GO-Ti absorbed most amount of DEX and released in a sustained manner. CCK-8 results showed that DEX-GO-Ti showed excellent performance on promoting cell proliferation. RMBSCs on DEX-GO-Ti presented greatly high expression of calcium, proteins and mRNA related to osteogenic differentiation.SignificanceGO coated titanate nanostructrues on surfaces of Ti foils by a simple self-assembly method, showed excellent vechiles for DEX. The construct promoted proliferation and accelerated osteogenic differentiation of rBMSCs, and would be prosperous for their further applications.
Graphical abstract
http://ift.tt/2nvPBz0
Scholar : These new articles for Asian Journal of Political Science are available online
|
Effect of humic acid preloading on phosphate adsorption onto zirconium-modified zeolite
Abstract
A zirconium-modified zeolite (ZrMZ) was prepared, and then, humic acid (HA) was immobilized on the ZrMZ surface to prepare HA-loaded ZrMZ (HA-ZrMZ). The obtained ZrMZ and HA-ZrMZ were characterized by energy dispersive X-ray spectroscopy, elemental analyzer, N2 adsorption/desorption isotherms, pH at the point of zero charge, and X-ray photoelectron spectroscopy. The adsorption characteristics of phosphate on ZrMZ and HA-ZrMZ were comparatively investigated in batch mode. The adsorption mechanism of phosphate on ZrMZ and HA-ZrMZ was investigated by ionic strength effect and 31P nuclear magnetic resonance. The mechanism for phosphate adsorption onto ZrMZ was the formation of inner-sphere phosphate complexes at the solid/solution interface. The preloading of HA on ZrMZ reduced the phosphate adsorption capacity, and the more the HA loading amount, the lower the phosphate adsorption capacity. However, the preloading of HA on ZrMZ did not change the phosphate adsorption mechanism; i.e., the formation of inner-sphere phosphate surface complexes was still responsible for the adsorption of phosphate on HA-ZrMZ. The decreased phosphate adsorption capacity for ZrMZ after HA coating could be attributed to the fact that the coating of HA on ZrMZ reduced the amount of binding active sites available for phosphate adsorption, changed the adsorbent surface charges, and reduced the specific surface areas and pore volumes of ZrMZ.
http://ift.tt/2ocxs7O
Occurrence and geographic distribution of polycyclic aromatic hydrocarbons in agricultural soils in eastern China
Abstract
Polycyclic aromatic hydrocarbons (PAHs) in agricultural soils, eastern China, were studied through a collection of surface samples at 109 sites. The study covered US EPA priority pollutants but also several non-priority isomers including some dibenzopyrenes which are expected to have higher toxic potentials. The total PAH concentrations varied extensively from 8.8 to 3880 μg/kg, with a geometric mean of 158 μg/kg. There were significant differences in both the concentrations and composition profiles between the south and the north regions. The overall geographical distribution pattern was strongly influenced by both the per capita gross domestic product and soil organic carbon (SOC) content. The former is an indicator of anthropogenic emissions while soil SOC content is associated with the accumulative capacities of the soils. The sequestration mechanism is an important process controlling fates of PAHs in agricultural soil.
http://ift.tt/2nvJXgi
Characterization of suspended bacteria from processing units in an advanced drinking water treatment plant of China
Abstract
For the drinking water treatment plant (DWTP), the organic pollutant removal was the primary focus, while the suspended bacterial was always neglected. In this study, the suspended bacteria from each processing unit in a DWTP employing an ozone-biological activated carbon process was mainly characterized by using heterotrophic plate counts (HPCs), a flow cytometer, and 454-pyrosequencing methods. The results showed that an adverse changing tendency of HPC and total cell counts was observed in the sand filtration tank (SFT), where the cultivability of suspended bacteria increased to 34%. However, the cultivability level of other units stayed below 3% except for ozone contact tank (OCT, 13.5%) and activated carbon filtration tank (ACFT, 34.39%). It meant that filtration processes promoted the increase in cultivability of suspended bacteria remarkably, which indicated biodegrading capability. In the unit of OCT, microbial diversity indexes declined drastically, and the dominant bacteria were affiliated to Proteobacteria phylum (99.9%) and Betaproteobacteria class (86.3%), which were also the dominant bacteria in the effluent of other units. Besides, the primary genus was Limnohabitans in the effluents of SFT (17.4%) as well as ACFT (25.6%), which was inferred to be the crucial contributors for the biodegradable function in the filtration units. Overall, this paper provided an overview of community composition of each processing units in a DWTP as well as reference for better developing microbial function for drinking water treatment in the future.
http://ift.tt/2och5Is
Fe plaque-related aquatic uranium retention via rhizofiltration along a redox-state gradient in a natural Phragmites australis Trin ex Steud. wetland
Abstract
Studies have revealed that the rhizofiltration is a feasible plant-based technology for aquatic metal/metalloid removal. However, the performance of aquatic U retention via rhizofiltration has not been fully revealed yet. In this study, a field investigation was conducted in a Phragmites australis Trin ex Steud. dominated wetland to estimate the efficiency of Fe plaque (IP)-assisted U rhizofiltration, with redox-state gradient (−179 to 220 mV) and low aquatic U level (66.7 to 92.0 μg l−1). The U concentrations were determined in soil, root, and aboveground biomass of P. australis. The IP on root surface was extracted via DCB extraction procedure. The bio-concentration factor (BCF) was applied to evaluate the aquatic U transfer capacity from root to above ground biomass of P. australis. The result suggested that root of P. australis was highly effective for aquatic U uptake via rhizofiltration (BCF 1025 to 1556). It also benefited the real U accumulation in aboveground biomass of P. australis (up to 0.4 mg m−2) and related plant-water-soil U recycling. The IP and associated microbial community in rhizosphere was effective mediator for aquatic U retention on root surface (BCF 1162 to 847). The IP-assisted aquatic U rhizofiltration was significantly promoted in relatively reductive environment. It was benefited by the enhanced root uptake of Fe due to lower oxidizers (e.g., DO and NO3−) availability. On the other hand, the competitive adsorption effect from co-existing IP-affinitive elements (e.g., As) also possibly impaired the real capacity of IP-assisted aquatic U rhizofiltration via P. australis.
http://ift.tt/2nvWznD
Cholinesterase characterization of two autochthonous species of Ria de Aveiro ( Diopatra neapolitana and Solen marginatus ) and comparison of sensitivities towards a series of common contaminants
Abstract
Biomonitoring of chemical contamination requires the use of well-established and validated tools, including biochemical markers that can be potentially affected by exposure to important environmental toxicants. Cholinesterases (ChEs) are present in a large number of species and have been successfully used for decades to discriminate the environmental presence of specific groups of pollutants. The success of cholinesterase inhibition has been due to their usefulness as a biomarker to address the presence of organophosphate (OP) and carbamate (CB) pesticides. However, its use in ecotoxicology has not been limited to such chemicals, and several other putative classes of contaminants have been implicated in cholinesterasic impairment. Nevertheless, the use of cholinesterases as a monitoring tool requires its full characterization in species to be used as test organisms. This study analyzed and differentiated the various cholinesterase forms present in two autochthonous organisms from the Ria de Aveiro (Portugal) area, namely the polychaete Diopatra neapolitana and the bivalve Solen marginatus, to be used in subsequent monitoring studies. In addition, this study also validated the putative use of the now characterized cholinesterasic forms by analyzing the in vitro effects of common anthropogenic contaminants, such as detergents, pesticides, and metals. The predominant cholinesterasic form found in tissues of D. neapolitana was acetylcholinesterase, while homogenates of S. marginatus were shown to possess an atypical cholinesterasic form, with a marked preference for propionylthiocholine. Cholinesterases from D. neapolitana were generally non-responsive towards the majority of the selected chemicals. On the contrary, strong inhibitory effects were reported for ChEs of S. marginatus following exposure to the selected pesticides.
http://ift.tt/2octAno
Anatomic Variations of the Right Portal Vein: Prevalence, Imaging Features, and Implications for Successful Transjugular Intrahepatic Portosystemic Shunt Creation
Senthil S Gunasekaran, Ron C Gaba
Journal of Clinical Imaging Science 2017 7(1):14-14
Given the widespread use of transjugular intrahepatic portosystemic shunt (TIPS) creation for the treatment of portal hypertensive complications, a working knowledge of portal venous anatomy is critical for interventional radiologists. The right portal vein – which is most commonly accessed during TIPS – is subject to various anatomic variants that may potentially impact procedure success. This pictorial essay characterizes the anatomic patterns of the right portal vein branching in terms of type and frequency based on case series review. The work also explains the potential procedural implications of the right portal vein anatomic variations as they pertain to TIPS technical success.
http://ift.tt/2nqoNP4
Journal of Clinical Imaging Science 2017 7(1):14-14
Given the widespread use of transjugular intrahepatic portosystemic shunt (TIPS) creation for the treatment of portal hypertensive complications, a working knowledge of portal venous anatomy is critical for interventional radiologists. The right portal vein – which is most commonly accessed during TIPS – is subject to various anatomic variants that may potentially impact procedure success. This pictorial essay characterizes the anatomic patterns of the right portal vein branching in terms of type and frequency based on case series review. The work also explains the potential procedural implications of the right portal vein anatomic variations as they pertain to TIPS technical success.
http://ift.tt/2nqoNP4
Radiologic-Pathologic Correlation: Acellular Dermal Matrix (Alloderm®) Used in Breast Reconstructive Surgery
Christine U Lee, Aleh Bobr, Jorge Torres-Mora
Journal of Clinical Imaging Science 2017 7(1):13-13
Acellular dermal matrix (ADM) such as Alloderm® is sometimes used in tissue reconstruction in primary and reconstructive breast surgeries. As ADM is incorporated into the native tissues, the evolving imaging findings that would correlate with varying degrees of host migration and neoangiogenesis into the matrix can be challenging to recognize. In the setting of a palpable or clinical area of concern after breast reconstructive surgery following breast cancer, confident diagnosis of a mass representing ADM rather than recurring or developing disease can be challenging. Such diagnostic imaging uncertainties generally result in short-term imaging and clinical follow-up, but occasionally, biopsy is performed for histopathological confirmation of benignity. A case of biopsy-proven Alloderm® is described. To the best of our knowledge, this is the first radiologic-pathologic correlation of ADM in the literature.
http://ift.tt/2nHku47
Journal of Clinical Imaging Science 2017 7(1):13-13
Acellular dermal matrix (ADM) such as Alloderm® is sometimes used in tissue reconstruction in primary and reconstructive breast surgeries. As ADM is incorporated into the native tissues, the evolving imaging findings that would correlate with varying degrees of host migration and neoangiogenesis into the matrix can be challenging to recognize. In the setting of a palpable or clinical area of concern after breast reconstructive surgery following breast cancer, confident diagnosis of a mass representing ADM rather than recurring or developing disease can be challenging. Such diagnostic imaging uncertainties generally result in short-term imaging and clinical follow-up, but occasionally, biopsy is performed for histopathological confirmation of benignity. A case of biopsy-proven Alloderm® is described. To the best of our knowledge, this is the first radiologic-pathologic correlation of ADM in the literature.
http://ift.tt/2nHku47
Comments to special issue geogenic radiation and its potential use for developing the geogenic radon map
Source:Journal of Environmental Radioactivity, Volume 172
Author(s): Ilia Yarmoshenko, Georgy Malinovsky, Aleksey Vasilyev
http://ift.tt/2nHogdC
Scholar : Cartography and Geographic Information Science, Volume 44, Issue 4, July 2017 is now available online on Taylor & Francis Online
|
Novel t(5;11)(q32;q13.4) with NUMA1-PDGFRB fusion in a myeloid neoplasm with eosinophilia with response to imatinib mesylate
Source:Cancer Genetics
Author(s): Ying S. Zou, Nicole L. Hoppman, Zeba N. Singh, Sameer Sawhney, Sandy D. Kotiah, Maria R. Baer
We report a NUMA1-PDGFRB fusion in a myeloproliferative neoplasm with eosinophilia in a 61-year old man, with response to imatinib mesylate therapy. A t(5;11) chromosome translocation involving bands 5q32 and 11q13.4 was identified by metaphase chromosome analysis, and rearrangement of the platelet-derived growth factor receptor beta (PDGFRB) gene on 5q32 was demonstrated by FISH using a PDGFRB break-apart probe set. Bacterial artificial chromosome (BAC) FISH mapping of the PDGFRB fusion partner gene narrowed the breakpoint at 11q13.4 to a 150 kb genomic region containing three genes, including NUMA1. Mate pair sequencing analysis demonstrated NUMA1-PDGFRB fusion. The fusion protein includes coiled-coil domains of nuclear mitotic apparatus protein 1 (NuMA1, involved in protein homodimerization and heteroassociation) and tyrosine kinase domains of PDGFRB. Diverse rearrangements involving the PDGFRB gene have been identified in myeloid and lymphoid neoplasms with eosinophilia, but rearrangement of the nuclear mitotic apparatus protein 1 (NUMA1) gene has been reported in a human malignancy in only one instance, a NUMA1-RARA fusion caused by a t(11;17) translocation in a patient with acute promyelocytic leukemia. The NUMA1-PDGFRB fusion is the second instance of rearrangement of NUMA1, encoding an element of the mitotic apparatus, in a human cancer.
http://ift.tt/2ndOl0V
Scholar : These new articles for Archives of Agronomy and Soil Science are available online
|
Correction: A Cross-Sectional Study of Colonization Rates with Methicillin-Resistant Staphylococcus aureus (MRSA) and Extended-Spectrum Beta-Lactamase (ESBL) and Carbapenemase-Producing Enterobacteriaceae in Four Swiss Refugee Centres.
Correction: A Cross-Sectional Study of Colonization Rates with Methicillin-Resistant Staphylococcus aureus (MRSA) and Extended-Spectrum Beta-Lactamase (ESBL) and Carbapenemase-Producing Enterobacteriaceae in Four Swiss Refugee Centres.
PLoS One. 2017;12(3):e0174911
Authors: Piso RJ, Käch R, Pop R, Zillig D, Schibli U, Bassetti S, Meinel DM, Egli A
Abstract
[This corrects the article DOI: 10.1371/journal.pone.0170251.].
PMID: 28346533 [PubMed - in process]
http://ift.tt/2o5UHn6
Molecular epidemiology of Staphylococcus aureus nasal colonization among patients and their parents /guardian in an Iranian referral hospital.
| Related Articles |
Molecular epidemiology of Staphylococcus aureus nasal colonization among patients and their parents /guardian in an Iranian referral hospital.
Microb Pathog. 2017 Mar 22;:
Authors: Pourakbari B, Khodabandeh M, Mahmoudi S, Sabouni F, Aziz-Ahari A, Bahador A, Valian SK, Sadeghi RH, Mamishi S
Abstract
INTRODUCTION: Carriage of Staphylococcus aureus in the nose appears to play a key role in the epidemiology and pathogenesis of infection. It is important to investigate the genetic relatedness of S. aureus and MRSA clones in different geographic regions. The aim of this study was to assess the nasal carriage rate of S. aureus, including MRSA strains in both hospitalized children and general adult population (parents/guardian). In addition, antibiotic susceptibility pattern and molecular diversity of S. aureus in both population was evaluated in an Iranian referral pediatrics Hospital.
MATERIAL AND METHODS: All samples were obtained through nasal screening of patients and general adult population at admission and discharge day. The prevalence, resistance, and molecular diversity of all S. aureus isolates were examined.
RESULTS: In the current study, nasal carriage of S. aureus and Staphylococcus non aureus was identified in 384 (26%) and 1004 (68%) of the study population. The prevalence of MRSA nasal carriage in children and adults was 6.6% (29 out of 438) and 2.8% (29 out of 1046), respectively. Among S. aureus strains isolated obtained from patients and general adult population at admission day, high sensitivity to most of the antibiotics such as vancomycin (100%), rifampin (95%), linezolid (94%), quinupristin/dalfopristin (94%), minocycline (94%), chloramphenicol (89%), gentamycin (87%), amikacin (87%), clindamycin (86%) and moxifloxacin (83%) was seen. The most resistance antibiotics were penicillin (96-98%) and methicillin (44-47%). The susceptibility patterns of nasal S. aureus strains isolated at discharge day was not statistically different from S. aureus isolates obtained at admission day. Admission S. aureus isolated strains of 77 patients (64%) were similar to the isolated S. aureus strains of discharge, while S. aureus isolated strains of 43 patients (36%) was not similar to the strain of discharge (had similarity of less than 70%).
CONCLUSION: High prevalence of nasal carriage of S. aureus and MRSA indicates the urgent need to improve strategies for management of S. aureus infections. Our findings are useful for understanding of S. aureus nasal colonization dynamics within the patients and general population. Surveillance for S. aureus in community settings can provide data on circulating strains and might help developing control measures for reducing of infection spread in hospitals.
PMID: 28342937 [PubMed - as supplied by publisher]
http://ift.tt/2ndFSuO
Cost-Effectiveness of Staphylococcus aureus Decolonization Strategies in High-Risk Total Joint Arthroplasty Patients.
| Related Articles |
Cost-Effectiveness of Staphylococcus aureus Decolonization Strategies in High-Risk Total Joint Arthroplasty Patients.
J Arthroplasty. 2017 Feb 07;:
Authors: Williams DM, Miller AO, Henry MW, Westrich GH, Ghomrawi HM
Abstract
BACKGROUND: The risk of prosthetic joint infection increases with Staphylococcus aureus colonization. The cost-effectiveness of decolonization is controversial. We evaluated cost-effectiveness decolonization protocols in high-risk arthroplasty patients.
METHODS: An analytical model evaluated risk under 3 protocols: 4 swabs, 2 swabs, and nasal swab alone. These were compared to no-screening and universal decolonization strategies. Cost-effectiveness was evaluated from the hospital, patient, and societal perspective.
RESULTS: Under base case conditions, universal decolonization and 4-swab strategies were most effective. The 2-swab and universal decolonization strategy were most cost-effective from patient and societal perspectives. From the hospital perspective, universal decolonization was the dominant strategy (much less costly and more effective).
CONCLUSION: S aureus decolonization may be cost-effective for reducing prosthetic joint infections in high-risk patients. These results may have important implications for treatment of patients and for cost containment in a bundled payment system.
PMID: 28341280 [PubMed - as supplied by publisher]
http://ift.tt/2ndNj5b
Orthogonal LC/MS methods for the comprehensive characterization of therapeutic glycoproteins, from released glycans to intact protein level
Publication date: Available online 27 March 2017
Source:Journal of Chromatography A
Author(s): Eric Largy, Fabrice Cantais, Géry Van Vyncht, Alain Beck, Arnaud Delobel
Proteins are increasingly used as therapeutics. Their characterization is challenging due to their size and inherent heterogeneity notably caused by post-translational modifications, among which glycosylation is probably the most prominent. The glycosylation profile of therapeutic proteins must therefore be thoroughly analyzed. Here, we illustrate how the use of a combination of various cutting-edge LC or LC/MS(/MS) methods, and operating at different levels of analysis allows the comprehensive characterization of both the N- and O-glycosylations of therapeutic proteins without the need for other approaches (capillary electrophoresis, MALDI-TOF). This workflow does not calls for the use of highly specialized/custom hardware and software nor an extensive knowledge of glycan analysis. Most notably, we present the point of view of a contract research organization, with the constraints associated to the work in a regulated environment (GxP). Two salient points of this work are i) the use of mixed-mode chromatography as a fast and straightforward mean of profiling N-glycans sialylation as well as an orthogonal method to separate N-glycans co-eluting in the HILIC mode; and ii) the use of widepore HILIC/MS to analyze challenging N/O-glycosylation profiles at both the peptide and subunit levels. A particular attention was given to the sample preparations in terms of duration, specificity, versatility, and robustness, as well as the ease of data processing.
http://ift.tt/2mLCTNT
Conservative management of thumb carpometacarpal osteoarthritis: An Italian survey of current clinical practice
Publication date: Available online 28 March 2017
Source:Journal of Bodywork and Movement Therapies
Author(s): Jorge Hugo Villafañe, Kristin Valdes, Virginia O'Brien, Monica Seves, Raquel Cantero-Téllez, Pedro Berjano
ObjectiveThe purpose of this study was to elucidate expert opinion in the conservative treatment of thumb carpometacarpal (CMC) joint osteoarthritis (OA).MethodsA 21-item survey to determine the practice patterns of Italian hand therapists who treat arthritis of the CMC joint was developed and distributed through a professional online survey service to assure confidentiality and anonymity.ResultsOf the respondents, 80.8% were physical therapists; the remaining 19.2% were occupational therapists. 84.6% of the specialists who make decisions regarding patient pain management education.ConclusionsThere is variability in the knowledge and practice patterns of Italian hand therapists relating to conservative management of thumb CMC OA.
http://ift.tt/2nvI6bo
Investigating the Anticipatory Postural Adjustment Phase of Gait Initiation in Different Directions in Chronic Ankle Instability Patients
Publication date: Available online 27 March 2017
Source:Journal of Bodywork and Movement Therapies
Author(s): Zahra Ebrahimabadi, Sedigheh Sadat Naimi, Abbas Rahimi, Heydar Sadeghi, Seyed Majid Hosseini, Alireza Akbarzadeh Baghban, Syed Asadullah Arslan
ObjectiveThe main objective of the present study was to analyze how supra spinal motor control mechanisms are altered in different directions during anticipatory postural phase of gait initiation in chronic ankle instability patients. It seems that supra spinal pathways modulate anticipatory postural adjustment phase of gait initiation. Yet, there is a dearth of research on the effect of chronic ankle instability on the anticipatory postural adjustment phase of gait initiation in different directions.MethodA total of 20 chronic ankle instability participants and 20 healthy individuals initiated gait on a force plate in forward, 30° lateral, and 30° medial directions.ResultsAccording to the results of the present study, the peak lateral center of pressure shift decreased in forward direction compared to that in other directions in both groups. Also, it was found that the peak lateral center of pressure shift and the vertical center of mass velocity decreased significantly in chronic ankle instability patients, as compared with those of the healthy individuals.ConclusionAccording to the results of the present study, it seems that chronic ankle instability patients modulate the anticipatory postural adjustment phase of gait initiation, compared with healthy control group, in order to maintain postural stability. These changes were observed in different directions, too.
http://ift.tt/2oc1CYK
The science of respiratory characteristics in individuals with chronic low back pain: Interpreting through statistical perspective
Publication date: Available online 28 March 2017
Source:Journal of Bodywork and Movement Therapies
Author(s): Vikram Mohan, Aatit Paungmali, Patraporn Sitilertpisan
http://ift.tt/2nvICWL
Radiation-induced rib fractures after stereotactic body radiation therapy: Predict to prevent?
Publication date: Available online 27 March 2017
Source:Radiotherapy and Oncology
Author(s): Robin Wijsman, Pètra M. Braam, Johan Bussink
http://ift.tt/2nvhuao
Changing cortical inhibition in the course of amyotrophic lateral sclerosis
Source:Clinical Neurophysiology
Author(s): Michael Swash
http://ift.tt/2o5KJlY
Starving for survival—how catabolic metabolism fuels immune function
Source:Current Opinion in Immunology, Volume 46
Author(s): Maria L Balmer, Christoph Hess
Infections disturb homeostasis and often induce a switch to catabolic organismal metabolism. During catabolism, increased systemic availability of glucose, fatty acids and ketone bodies is observed, and recent evidence indicates that these metabolites might serve an immunomodulatory function. However, whereas our understanding of direct pathogen recognition by the host immune system is quite detailed, much less is known about the immunobiology of the metabolic host response to infection. In this review article we briefly discuss how pathogens induce 'dys-homeostasis' systemically, locally, and within cells, and provide examples of how such changes can shape immune-functionality during the course of an infection.
http://ift.tt/2nbTXbm
Obesity altered T cell metabolism and the response to infection
Source:Current Opinion in Immunology, Volume 46
Author(s): William D Green, Melinda A Beck
An epidemic of obesity over the past three decades increases the risk of chronic and infectious diseases for adults and children alike. Within the past few years, obesity has been shown to impair the adaptive immune response to infection through alterations in T cell functioning. Growing evidence suggests that perturbations in T cell metabolism drives this stunted immune response, stemming from nutrient, hormone and adipokine dysregulation in the obese. In this review, recent findings in the fields of obesity and T cell mediated immunity demonstrate a unique relationship between altered mechanisms of T cell metabolic homeostasis and plasticity of adaptive immune responses in the obese setting.
http://ift.tt/2o5OZBE
Developmental options and functional plasticity of innate lymphoid cells
Source:Current Opinion in Immunology, Volume 44
Author(s): Ai Ing Lim, Thomas Verrier, Christian AJ Vosshenrich, James P Di Santo
Innate lymphoid cells (ILCs) are lineage- and antigen receptor-negative lymphocytes including natural killer (NK) cells and at least three distinguishable cell subsets (ILC1, ILC2, ILC3) that rapidly produce cytokines (IFN-γ, IL-5, IL-13, IL-17A, IL-22) upon activation. As such, ILCs can act as first-line defenders in the context of infection, inflammation and cancer. Because of the strong conservation between the expression of key transcription factors that can drive signature cytokine outputs in ILCs and differentiated helper T cells, it has been proposed that ILCs represent innate counterparts of the latter. Several distinct ILC precursors (ILCP) with pan-ILC (giving rise to all ILCs) or subset-restricted potentials have been described in both mouse and man. How and where these different ILCP give rise to more mature tissue-resident ILCs remains unclear. Recently, environmental signals have been shown to epigenetically influence canonical ILC differentiation pathways, generating substantial functional plasticity. These new results suggest that while ILC differentiation may be 'fixed' in principle, it remains 'flexible' in practice. A more comprehensive knowledge in the molecular mechanisms that regulate ILC development and effector functions may allow for therapeutic manipulation of ILCs for diverse disease conditions.
http://ift.tt/2nc68EN
Regulation of memory B and plasma cell differentiation
Source:Current Opinion in Immunology, Volume 45
Author(s): Ryo Shinnakasu, Tomohiro Kurosaki
Memory B cell generation and antibody production result from a differentiation process that begins when the surface BCR on naïve B cells binds an antigen. How the choice between these fates is tempo-spatially regulated is still obscure, but recent advances have reinforced the concept that the combination of B cell-intrinsic heterogeneity and -extrinsic heterogeneity provided by cells such as T cells is a key determinant. As molecular regulators, the transcription factors IRF4 and Bach2, which participate in these fate choices, have been emerging.
http://ift.tt/2nc337Z
Scholar : New articles have been published for Baltic Journal of Economics, Volume 17, Issue 1
|
Scholar : These new articles for Aging & Mental Health are available online
|
Immune hyperreactivity of Aβ plaque-associated microglia in Alzheimer’s disease
Publication date: Available online 27 March 2017
Source:Neurobiology of Aging
Author(s): Zhuoran Yin, Divya Raj, Nasrin Saiepour, Debby Van Dam, Nieske Brouwer, Inge R. Holtman, Bart J.L. Eggen, Thomas Möller, Joseph A. Tamm, Aicha Abdourahman, Elly M. Hol, Willem Kamphuis, Thomas A. Bayer, Peter P. De Deyn, Erik Boddeke
Alzheimer's disease (AD) is strongly associated with microglia-induced neuroinflammation. Particularly, Aβ plaque-associated microglia take on an "activated" morphology. However, the function and phenotype of these Aβ plaque-associated microglia are not well understood. We show hyperreactivity of Aβ plaque-associated microglia upon systemic inflammation in transgenic AD mouse models (i.e., 5XFAD and APP23). Gene expression profiling of Aβ plaque-associated microglia (MHC II+ microglia) isolated from 5XFAD mice revealed a proinflammatory phenotype. The upregulated genes involved in the biological processes (gene ontology terms) including "immune response to external stimulus" such as Axl, Cd63, Egr2, and Lgals3, "cell motility", such as Ccl3, Ccl4, Cxcr4, and Sdc3, "cell differentiation", and "system development", such as St14, Trpm1, and Spp1. In human AD tissue with similar Braak stages, expression of phagocytic markers and AD-associated genes, including HLA-DRA, APOE, AXL, TREM2, and TYROBP, was higher in laser-captured early-onset AD (EOAD) plaques than in late-onset AD (LOAD) plaques. Interestingly, the non-plaque parenchyma of both EOAD and LOAD brains, the expression of above-mentioned markers were similarly low. Here, we provide evidence that Aβ plaque-associated microglia are hyperreactive in their immune response and phagocytosis in the transgenic AD mice as well as in EOAD brain tissue. We suggest that Aβ plaque-associated microglia are the primary source of neuroinflammation related to AD pathology.
http://ift.tt/2oc2Cw0
Multifocal but Non-Disseminated Phaeohyphomycosis in a Healthy Man via a Unique Mechanism: Ejection from MVA into a Vegetable Field in Afghanistan Resulting in Multiple Contaminated Skin Wounds
Abstract
A 20 year-old male presented with multiple subcutaneous nodules on the head, neck, chest and oral cavity. FNA and biopsy showed pigmented fungal hyphae diagnostic of multifocal phaeohyphomycosis, found to be Exophiala spinifera by molecular diagnostics. The presentation initially raised concern for disseminated disease and occult immunosuppression. However, the patient appeared to be immunocompetent and otherwise healthy. Upon further inquiry, the patient was in a motor vehicle accident four years before presentation; he was ejected into a vegetable field resulting in multiple open wounds. Multifocal phaeohyphomycosis usually indicates disseminated systemic disease from immunosuppression and carries a grave prognosis.
http://ift.tt/2obZK25
Opsoclonus-myoclonus syndrome: a new era of improved prognosis?
Publication date: Available online 27 March 2017
Source:Pediatric Neurology
Author(s): Armine Galstyan, Colin Wilbur, Kathryn Selby, Juliette Hukin
BackgroundOpsoclonus-myoclonus syndrome (OMS) is an autoimmune neurologic disorder characterized by opsoclonus, myoclonus, ataxia, and behavioral changes. While long-term outcomes have historically been poor, including motor and cognitive disabilities, the advent of new and more aggressive immunotherapy regimens may be improving prognosis in OMS.MethodsA retrospective chart review was performed of all children diagnosed with OMS at BC Children's Hospital from 2000-2010. Neurologic outcomes were compared to those previously reported in the literature.ResultsTwelve children with OMS were identified, 4 of whom had an associated neuroblastoma. Two-thirds of patients received initial treatment with a combination of corticosteroids, intravenous immunoglobulin (IVIG), and an additional immunosuppressant agent. After a median follow-up of 3 years from diagnosis, 10 patients had no or minimal neurologic abnormalities. Two patients had poor outcome with significant cognitive impairment.ConclusionsThe majority of patients in this series were treated with early multimodal immunotherapy and neurologic outcomes were better than most historical reports. This is consistent with recent studies that suggest multimodal immunotherapy regimens may be improving the prognosis in this challenging disease. However, some did well with less aggressive treatment and further studies are required to determine optimal treatment approach.
http://ift.tt/2oc7BwS
Theory of Animal Mind: Human Nature or Experimental Artefact?
Publication date: Available online 27 March 2017
Source:Trends in Cognitive Sciences
Author(s): Caroline E. Spence, Magda Osman, Alan G. McElligott
Are animals capable of empathy, problem-solving, or even self-recognition? Much research is dedicated to answering these questions and yet few studies have considered how humans form beliefs about animal minds. Evidence suggests that our mentalising of animals is a natural consequence of Theory of Mind (ToM) capabilities. However, where beliefs regarding animal mind have been investigated, there has been slow progress in establishing the mechanism underpinning how this is achieved. Here, we consider what conclusions can be drawn regarding how people theorise about animal minds and the different conceptual and methodological issues that might limit the accuracy of conclusions currently drawn from this work. We suggest a new empirical framework for better capturing the human theory of animal mind, which in turn has significant political and social implications.
http://ift.tt/2o127aU
Influence of natural zeolite and nitrification inhibitor on organics degradation and nitrogen transformation during sludge composting
Abstract
Sludge composting is one of the most widely used treatments for sewage sludge resource utilization. Natural zeolite and nitrification inhibitor (NI) are widely used during composting and land application for nitrogen conservation, respectively. Three composting reactors (A—the control, B—natural zeolite addition, and C—3,4-dimethylpyrazole phosphate (DMPP) addition) were established to investigate the influence of NI and natural zeolite addition on organics degradation and nitrogen transformation during sludge composting conducted at the lab scale. The results showed that, in comparison with the control, natural zeolite addition accelerated organics degradation and the maturity of sludge compost was higher, while the DMPP addition slowed down the degradation of organic matters. Meanwhile, the nitrogen transformation functional genes including those responses for nitrification (amoA and nxrA) and denitrification (narG, nirS, nirK, and nosZ) were quantified through quantitative PCR (qPCR) to investigate the effects of natural zeolites andDMPP addition on nitrogen transformation. Although no significant difference in the abundance of nitrogen transformation functional genes was observed between treatments, addition of both natural zeolite and DMPP increases the final total nitrogen content by 48.6% and 23.1%, respectively. The ability of natural zeolite for nitrogen conservation was due to the absorption of NH3 by compost, and nitrogen conservation by DMPP was achieved by the source reduction of denitrification. Besides, it was assumed that the addition of natural zeolite and DMPP may affect the activity of these genes instead of the abundance.
http://ift.tt/2nGWmhU
Integrating ecosystem services in terrestrial conservation planning
Abstract
The purpose of this study is to estimate the benefits of ecosystem services for prioritization of land use conservation and to highlight the importance of ecosystem services by comparison between ecosystem service value and green GDP accounting. Based on land use pattern and benefit transfer method, this research estimated value of ecosystem services in Taiwan. Scientific information of land use and land cover change is accessed through multi-year satellite imagery moderate resolution imaging spectroradiometer (MODIS), and geographic information system (GIS) technology. Combined with benefit transfer method, this research estimated the ecosystem service valuation of forest, grassland, cropland, wetland, water, and urban for the period of 2000 to 2015 in Taiwan. It is found that forest made the greatest contribution and the significant increasing area of wetland has huge potential benefit for environmental conservation in Taiwan. We recommend placing maintaining wetland ecosystem in Taiwan with higher priority. This research also compared ecosystem service value with natural capital consumption which would essentially facilitate policy makers to understand the relationship between benefits gained from natural capital and the loss from human-made capital.
http://ift.tt/2obTrvq
Ultra-light extensometer for the assessment of the mechanical properties of the human skin in vivo
Background/purpose:
This paper aims to present an ultra-light extensometer device dedicated to the mechanical characterization of the human skin in vivo.
Methods
The device developed was conceived to be non-invasive, to work without any stand and to perform various uniaxial tensile tests with either effort or displacement control. We also use specific guarding tabs to make in vivo extension tests analogous to traction tests.
Results
Force-displacement curves are derived from the data provided by the device's sensors. The latter are converted into stress-strain curves thanks to complementary measurements of the skin thickness. We present typical experimental data and results that demonstrate the device ability to built stress-strain curves characteristic of the human skin behavior. An additional imaging unit records a sequence of images of the solicited skin area for further calculations of the displacement fields by digital image correlation.
Conclusion
The analysis of the displacement and deformation fields validates the guarding tab efficiency and the capacity of the device to characterize the mechanical behavior of the human skin in vivo.
http://ift.tt/2otlh5Y
Title page/Editorial Board
Source:Medical Hypotheses, Volume 101
http://ift.tt/2nvgAec
In vivo IL-4 prevents allo-antigen driven CD8+ CTL development
Source:Clinical Immunology
Author(s): Charles S. Via, Kateryna Soloviova, Maksym Puliaiev, Roman Puliav, Irina Puliaeva, Suzanne C. Morris, Fred D. Finkelman
IL-4 has been shown to suppress acute graft vs. host disease (GVHD) in irradiated hosts. Here we evaluated whether IL-4 suppresses acute GVHD in the un-irradiated parent-into-F1 GVHD model with relevance to renal allograft rejection. IL-4 completely suppressed CD8 CTL when administered with donor cells however this effect was lost if its administration was delayed 3days. IL-4 did not inhibit donor CD8+ T cell homing to the host spleen but rather prevented donor CD8+ T cell differentiation into CTLs. Studies with IL-4Rα-deficient donor cells or recipient mice demonstrated that IL-4 effects on the host, rather than, or in addition to IL-4 effects on donor cells, were critical for suppression of CTL. Because IL-4 decreased all splenic dendritic cell populations and increased neutrophil and CD8+ T cells, IL-4 may suppress donor CD8+ CTL by decreasing Ag presentation and/or increasing host myeloid and CD8+ T cell suppression of donor T cells.
http://ift.tt/2o0QrVK
Systematic analysis of splicing defects in selected primary immunodeficiencies-related genes
Source:Clinical Immunology
Author(s): Lucie Grodecká, Pavla Hujová, Michal Kramárek, Tereza Kršjaková, Tatiana Kováčová, Katarína Vondrášková, Barbora Ravčuková, Kristýna Hrnčířová, Přemysl Souček, Tomáš Freiberger
Both variants affecting splice sites and those in splicing regulatory elements (SREs) can impair pre-mRNA splicing, eventually leading to severe diseases. Despite the availability of many prediction tools, prognosis of splicing affection is not trivial, especially when SREs are involved. Here, we present data on 92 in silico-/55 minigene-analysed variants detected in genes responsible for the primary immunodeficiencies development (namely BTK, CD40LG, IL2RG, SERPING1, STAT3, and WAS). Of 20 splicing-affecting variants, 16 affected splice site while 4 disrupted potential SRE. The presence or absence of splicing defects was confirmed in 30 of 32 blood-derived patients' RNAs. Testing prediction tools performance, splice site disruptions and creations were reliably predicted in contrast to SRE-affecting variants for which just ESRseq, ΔHZEI-scores and EX-SKIP predictions showed promising results. Next, we found an interesting pattern in cryptic splice site predictions. These results might help PID-diagnosticians and geneticists cope with potential splicing-affecting variants.
http://ift.tt/2otji1A
Editors, contents and cover information
Publication date: April 2017
Source:Trends in Biochemical Sciences, Volume 42, Issue 4
http://ift.tt/2mLlNjl
Splash Safety During Dermatologic Procedures Among US Dermatology Residents.
BACKGROUND: Dermatologists are at potential risk of acquiring infections from contamination of the mucous membranes by blood and body fluids. However, there are little data on splash safety during procedural dermatology. OBJECTIVE: To determine dermatology resident perceptions about splash risk during dermatologic procedures and to quantify the rate of protective equipment use. METHODS: An anonymous on-line survey was sent to 108 United States ACGME-approved dermatology residency programs assessing frequency of facial protection during dermatologic procedures, personal history of splash injury, and, if applicable, reasons for not always wearing facial protection. RESULTS: A total of 153 dermatology residents responded. Rates of facial protection varied by procedure, with the highest rates during surgery and the lowest during local anesthetic injection. Over 54% of respondents reported suffering facial splash while not wearing facial protection during a procedure. In contrast, 88.9% of respondents correctly answered that there is a small risk of acquiring infection from mucosal splash. Residency program recommendations for facial protection seem to vary by procedure. CONCLUSION: The authors' results demonstrate that although facial splash is a common injury, facial protection rates and protective recommendations vary significantly by procedure. These data support the recommendation for enhanced facial protection guidelines during procedural dermatology. (C) 2017 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. All rights reserved.
http://ift.tt/2nvekn1
http://ift.tt/2nvekn1
Histological Mohs Maps Improve the Accuracy of Dermatology Residents' Interpretations of Mohs Slides: A Pilot Study.
BACKGROUND: Effective Mohs surgery depends on accurate histopathological identification and mapping of tumor burden to ensure complete removal of tumor. OBJECTIVE: The purpose of this study is to evaluate whether using a photograph of the histopathological slide as the Mohs map improves mapping accuracy. METHODS AND MATERIALS: Single-blinded pilot study. Five dermatology residents at one academic institution mapped 11 cases of basal cell carcinoma using both traditional hand-drawn maps and color photographic maps. Residents' marked maps were assessed for global diagnostic accuracy, sensitivity, and specificity compared with the Mohs map verified by the attending surgeon on the day of surgery. RESULTS: Diagnostic accuracy, sensitivity, and specificity were higher using the photographic Mohs maps compared with using the traditional hand-drawn maps (58.2% vs 29.1%, 84.5% vs 76.4%, and 87.1% vs 70.8%, respectively). These results were statistically significant for accuracy and specificity, but not for sensitivity. CONCLUSION: Using histopathological photographs as the Mohs map significantly improved accuracy and specificity within a small group of residents with limited Mohs experience. More research is warranted to evaluate whether using histopathological photographs improves accuracy of Mohs mapping for experienced Mohs surgeons in a real-world setting, and whether this translates to improved clinical outcomes. (C) 2017 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. All rights reserved.
http://ift.tt/2ndmuxO
http://ift.tt/2ndmuxO
A Retrospective Case-Matched Cost Comparison of Surgical Treatment of Melanoma and Nonmelanoma Skin Cancer in the Outpatient Versus Operating Room Setting.
BACKGROUND: To date, no study has used authentic billing data in a case-control matched fashion to examine the cost of treating skin cancer in different settings. OBJECTIVE: To compare the cost of surgical treatment of skin cancer in the outpatient versus operating room setting using matched cases based on patient and skin cancer characteristics. METHODS: ICD-9 diagnosis codes for skin cancers were used to find patients who had a malignant excision current procedural terminology code in the operating room setting during 2010 to 2014. Patient and skin cancer characteristics were used to match cases to those treated as an outpatient. A total of 36 cases (18 operating room and 18 outpatient) had the required information and characteristics to be matched and analyzed for cost. Health status was determined using the American Society of Anesthesiologists anesthesia grading scale. RESULTS: No statistically significant differences were found in the age (p > 0.9) or American Society of Anesthesiologists scores (p > 0.6) of the outpatient and operating room cases. The median cost for outpatient cases was $1,745. For operating room cases, the median cost was $11,323. This was a statistically significant difference (p
http://ift.tt/2ndfj8R
http://ift.tt/2ndfj8R
Emerging roles for the amyloid precursor protein and derived peptides in the regulation of cellular and systemic metabolism
Abstract
The amyloid precursor protein (APP) is a transmembrane protein that can be cleaved by proteases through two different pathways to yield a number of small peptides, each with distinct physiological properties and functions. It has been extensively studied in the context of Alzheimer's disease, with the APP-derived amyloid beta (Aβ) peptide being a major constituent of the amyloid plaques observed in this disease. It has been known for some time that APP can regulate neuronal metabolism, however this review will examine evidence that APP and its peptides can also regulate key metabolic processes such as insulin action, lipid synthesis and storage and mitochondrial function in peripheral tissues. This review will present a hypothesis that amyloidogenic processing of APP in peripheral tissues plays a key role in the response to nutrient excess and that this could contribute to the pathogenesis of metabolic diseases such as obesity and type 2 diabetes (T2D).
This article is protected by copyright. All rights reserved.
http://ift.tt/2obPUgF
Multi-lobed composite polymer nanoparticles prepared by conventional emulsion polymerization
Publication date: 7 April 2017
Source:Polymer, Volume 114
Author(s): Diane Blenner, Jeffrey Stubbs, Donald Sundberg
The vast majority of latex particles, including those made from multiple polymers, are spherical in shape. This is a result of the minimization of the combined interfacial free energies at the polymer particle–water interface and the polymer–polymer interfaces within the particle. Yet there are special situations in which latex particles containing two, incompatible polymer phases can form asymmetric, multi-lobed particles during conventional, two stage emulsion polymerizations. Here we report on a variety of situations used to produce these interesting polymer particles and discuss the mechanism by which they are formed. The key condition is that the reaction process be carried out in a manner in which the second stage oligoradicals in the water are not allowed to significantly penetrate the first stage latex particle during the reaction. Then, the important variables are the relative differences between the interfacial tensions at the water-polymer interface for the two polymers in question, and the second stage polymer chain diffusivity on the surface of the first stage particles. By extension, the same fundamental parameters of interfacial tensions and polymer chain surface diffusion apply to the morphology possibilities when inorganic first stage particles are used to create inorganic-organic composite latices.
Graphical abstract
http://ift.tt/2obGodJ
Cross-linked polypeptide-based gel particles by emulsion for efficient protein encapsulation
Publication date: 21 April 2017
Source:Polymer, Volume 115
Author(s): Li-Wen Hsiao, Ying-Da Lai, Jinn-Tsyy Lai, Chia-Chen Hsu, Nai-Yi Wang, Steven S.-S. Wang, Jeng-Shiung Jan
We report the preparation of cross-linked poly(l-lysine) (PLL), polyethylene glycol-block-poly(l-lysine) (PEG-b-PLL), and poly(l-lysine)-block-polysarcosine (PLL-b-PSar) gel particles with size ranged between 100 and 250 nm by emulsion and their evaluation as carriers/encapsulants for protein encapsulation/delivery. Their size and solution property were depended upon polymer molecular weight, composition, and cross-linking degree. These gel particles exhibited not only excellent colloidal stability at a wide range of solution pH but also enhanced biocompatibility due to the incorporation of neutral polymer segments and genipin cross-link. We also showed that a variety of protein can be efficiently encapsulated in gel particles and the encapsulated protein still exhibited bioactivity. The in vitro protein release study showed that reduction-responsive gel particles can be prepared by incorporating disulfide bond in gel network. This study demonstrated that versatile gel particles comprising various types of polymers can be prepared and are potentially useful as protein carriers and encapsulants.
Graphical abstract
http://ift.tt/2obV2BI
Methoxy group substitution on catechol ring of dopamine facilitates its polymerization and formation of surface coatings
Publication date: 5 May 2017
Source:Polymer, Volume 116
Author(s): Jieyu Zhang, Yong Shung Cheah, Sridhar Santhanakrishnan, Koon Gee Neoh, Christina L.L. Chai
Deposition of polydopamine on substrates is a facile and effective method of surface modification and the deposited polydopamine can reduce silver ions to form silver nanoparticles (AgNPs) for antibacterial applications. However, polydopamine deposition is a time-consuming process that usually requires 24 h to produce a dense surface coating. Since oxidation of dopamine is critical for its polymerization, we hypothesize herein that substitution of an electron-donating group on the catechol ring of dopamine can enhance its oxidation potential and subsequently accelerate its polymerization. In this work, dopamine substituted with a 5-methoxy group (OMeDA) was prepared. OMeDA polymerized faster than dopamine under similar reaction conditions, resulting in a polymer coating of 13 nm thickness on a silicon surface after 8 h, compared to the 24 h required for dopamine to form a coating of similar thickness. A polymer layer with AgNPs can be directly formed on the silicon substrate after exposure to a solution containing OMeDA and silver nitrate. After 2 h exposure, the silver content on the modified surfaces prepared with OMeDA was 187% higher than that obtained with dopamine, and the antibacterial efficacy of the former against Staphylococcus aureus was correspondingly higher than that of the latter. This study demonstrates that OMeDA with an electron-donating group in the catechol ring offers improvements over dopamine for surface modification applications.
Graphical abstract
http://ift.tt/2obO7bF
Mechano-optical behavior of loosely crosslinked double-network hydrogels: Modeling and real-time birefringence measurement during uniaxial extension
Publication date: 21 April 2017
Source:Polymer, Volume 115
Author(s): S. Shams Es-haghi, I. Offenbach, D. Debnath, R.A. Weiss, M. Cakmak
Real-time uniaxial strain-induced birefringence in loosely crosslinked double-network (DN) hydrogels synthesized from acrylamide (AAm) and N,N-dimethyl(acrylamide) (DMA) was measured. Tensile tests were performed at different extension rates from quasi-static conditions to very rapid tests followed by a holding for relaxation. Both DN hydrogels exhibited negative birefringence whose absolute value increased with extension and remained constant during relaxation. DN hydrogel synthesized from AAm displayed a linear stress optical (birefringence – true stress) behavior, however, a nonlinear trend was observed for the DN gel synthesized from DMA. A simple photoelastic model was developed based on the mechanical behavior of the gels using Fung elastic potential and Brewster's stress-optical law, and the model was compared with the experimental data.
Graphical abstract
http://ift.tt/2obNM8F
Microfiltration performance of electrospun nanofiber membranes with varied fiber diameters and different membrane porosities and thicknesses
Publication date: 7 April 2017
Source:Polymer, Volume 114
Author(s): Zhao Wang, Caitlin Crandall, Rajesh Sahadevan, Todd J. Menkhaus, Hao Fong
Electrospun nanofiber membranes (with varied fiber diameters and different membrane porosities and thicknesses) have been explored as innovative microfiltration media for the highly efficient and cost-effective removal of contaminations with particle sizes of 0.2 μm (even 0.1 μm) from water. For the first time, the membrane porosity has been judiciously adjusted/controlled by a facile hot-pressing method; and the relationships between membrane properties and microfiltration performances have been systematically investigated. Upon the hot-pressing process, the membrane porosity could be significantly decreased from ∼86% to as low as ∼34%, further leading to the substantial increase of rejection fraction from 0% to ∼100% for 0.2 μm particles; moreover, some of these membranes (consisting of small diameter nanofibers) that were hot-pressed with relatively high pressure could even reject all of 0.1 μm particles. As compared to conventional microfiltration media, these membranes exhibited significantly higher flux values and substantially lower degrees of fouling without distinguishably sacrificing particle rejection fractions. For example, the rejection fraction and permeate flux value of one membrane (fiber diameters: ∼150–250 nm, membrane porosity: ∼40%) were ∼99.3% and ∼71.2·L·h−1·m−2·psi−1 at 13 mL volume fed, respectively, indicating that electrospun nanofiber membranes might be highly promising for microfiltration applications (particularly water purification).
Graphical abstract
http://ift.tt/2obO4N1
Poly(phenylene-carborane) for boron-carbide/carbon ceramic precursor synthesized via nickel catalysis
Publication date: 21 April 2017
Source:Polymer, Volume 115
Author(s): Shengli Cheng, Kuanyu Yuan, Xin Wang, Jianhua Han, Xigao Jian, Jinyan Wang
High thermally and thermo-oxidatively stable poly(phenylene-carborane) (PPB) was synthesized via Ni(0)-catalyzed polymerization of bis(aryl chloride) monomer containing carborane. This polymer was soluble in THF and NMP at room temperature, thus allowing molecular weight and spectroscopic analysis. Number-average molecular weight determined by 1H-NMR spectroscopy was 5.4 × 103 g/mol. The crystalline character of PPB was verified by XRD analysis. This polymer exhibited excellent thermal and thermo-oxidative stability with 5% weight loss temperature to be 707 °C and >1000 °C in nitrogen and air, respectively. High char yields of 93.2% and 97.9% were obtained at 1000 °C in nitrogen and air, respectively. Additionally, PPB has proven to be excellent sing-source precursor to boron-carbide/carbon ceramic materials with high ceramic yields in the range of 91.1%–92.6%. According to XRD analysis, boron carbide crystallization for PPB occurred between 1000 and 1200 °C.
Graphical abstract
http://ift.tt/2obYVGI
Measuring microgel swell ratio by cryo-SEM
Publication date: 5 May 2017
Source:Polymer, Volume 116
Author(s): Jing Liang, Feiyue Teng, Tseng-Ming Chou, Matthew Libera
The swell ratio is a key parameter characterizing the structure and properties of a hydrogel. In macroscopic gels, the swell ratio can be determined by straightforward measurements of the gel weight in the dry and hydrated states. However, measuring the swell ratio characteristic of microgels (gel particles with dimensions of 0.1–100 μm) is substantially more challenging because of their small size and polydispersity. We use cryo-scanning electron microscopy (cryo-SEM) to measure microgel diameter both in the frozen-hydrated and fully dry states using pH-responsive poly(ethylene glycol)-co-acrylic acid microgels. The volume swell ratios characteristic of the various microgels are essentially the same as those measured from otherwise-identical macroscopic gels. Hence we can conclude that, at least in this case where the macroscopic gel and microgel synthesis methods are similar, the simple measurement of a macroscopic swell ratio provides a reasonable approximation to the microgel swell ratio.
Graphical abstract
http://ift.tt/2obz5CF
Graphical Contents list & Author index
Publication date: 7 April 2017
Source:Polymer, Volume 114
http://ift.tt/2obRO18
Filler-induced heterogeneous distribution of stretch-induced crystallization in natural rubber: An in-situ synchrotron-radiation micro-focused scanning X-ray diffraction study
Publication date: 21 April 2017
Source:Polymer, Volume 115
Author(s): Liang Chen, Weiming Zhou, Fengmei Su, Wenhua Zhang, Pinzhang Chen, Youxin Ji, Liangbin Li
Crystallinity distribution of natural rubber around filled micrometer-size glass beads under different strains are studied with in-situ micro-focused scanning X-ray diffraction (μ-SXRD), where the glass beads are taken to serve as a model of filler. The experimental results suggest, due to the gradient stress field around the glass bead, the oscillatory distribution of crystallinities around the glass bead tends to form soft-hard double network with multi-scale hierarchical structures and spontaneously responds to external strains. The double network spreads stress in larger region and avoids stress concentration, in which the hard domains with high crystallinities effectively sustain the external stress while the soft domains with low crystallinity store elastic energy. According to the equal strain and equal stress conditions, the quantitative calculation on enhancement factor indicates that the soft-hard double network structure can increase the fracture energy to about three orders of magnitude as comparing to that of structure with homogeneous distribution of crystallinity.
Graphical abstract
http://ift.tt/2nv7Nsv
Strain accelerated mesophase separation during nonlinear stress relaxation of olefin multiblock copolymer
Publication date: 21 April 2017
Source:Polymer, Volume 115
Author(s): Zhijun Nie, Wei Yu
The nonlinear relaxation behavior of olefin multiblock copolymers subjected to step shear strains has been investigated. Compared to homogeneous polymer, a two-step relaxation behavior was identified in olefin multiblock copolymers, with the faster one for the chain relaxation and the slower one for the domain relaxation. It is found that the domain relaxation has stronger strain dependence than the chain relaxation. Large repeated step strains can cause longer relaxation process of domains as compared to the single step strain test. The prolonged domain relaxation and nearly constant relaxation plateau modulus are ascribed to the coarsening of domain as well as the increase of the volume fraction of domains, which indicates the accelerated mesophase separation of olefin multiblock copolymer under large strains.
Graphical abstract
http://ift.tt/2nuVexA
Preparation of Poly(poly(ethylene glycol)methyl ether methacrylate-co-styrene)-b-poly(2-(diethylamino)ethyl methacrylate-co-acrylonitrile) by nitroxide-mediated polymerisation in water
Publication date: 21 April 2017
Source:Polymer, Volume 115
Author(s): Ali Darabi, Michael F. Cunningham
The nitroxide-mediated polymerisation (NMP) of poly(ethylene glycol) methyl ether methacrylate (PEGMA) with a small amount of styrene (S) as a comonomer was performed in water at 90 °C using 2,2'-azobis [2-(2-imidazolin-2-yl)propane]dihydrochloride (VA-044) as initiator and N-tert-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl) nitroxide (SG1) as nitroxide. The reaction was well-controlled and exhibited excellent livingness as evidenced by low dispersity and evolution of the molar mass distribution. The resultant macroalkoxyamine was then employed in the nitroxide-mediated polymerisation of 2-(diethylamino)ethyl methacrylate hydrochloride (DEAEMAH+Cl−) with a small amount of acrylonitrile (AN) in water at 90 °C. The resulting poly (PEGMA-co-S)-b-poly (DEAEMAH+Cl−-co-AN) polymer chains were converted to diblock copolymer nanoparticles after neutralizing with base.
Graphical abstract
http://ift.tt/2nv1ANo
Evaluation of enzymatic formation of polyaniline nanoparticles
Publication date: 21 April 2017
Source:Polymer, Volume 115
Author(s): Natalija German, Anton Popov, Almira Ramanaviciene, Arunas Ramanavicius
Polyaniline (PANI) nanoparticles were synthesized by enzymatic polymerization of aniline monomers using glucose oxidase (GOx). The influence of aniline and GOx concentrations as well as the duration of the polymerization on the formation of PANI nanoparticles was investigated. The UV/Vis spectra of polymerization solution showed absorption peaks at 325 and 434 nm, which are characteristic for PANI emeraldine base. The increase of absorption at 434 nm was exploited for the monitoring of PANI formation. The most optimal duration for the formation of PANI nanoparticles was in the frame of 100–115 h. Extension of the polymerization time does not increased the efficiency of here proposed polymerization procedure. The highest rate of PANI nanoparticle formation was observed in solution containing 0.50 mol L−1 of aniline and 0.75 mg mL−1 of GOx. Hydrodynamic diameter of synthesized PANI nanoparticles was evaluated using dynamic light scattering technique. Hydrodynamic radius of formed GOx/PANI-nanoparticles increased from 15.8 nm up to 142 nm by prolongation of polymerization process. Synthesized PANI nanoparticles were characterized by cyclic voltammetry and two oxidation peaks at +0.51 and + 0.68 V were observed in cyclic voltammograms. These peaks are attributed to emeraldine form of PANI.
Graphical abstract
http://ift.tt/2obJPRH
Εγγραφή σε:
Αναρτήσεις (Atom)
-
Ειδοποίηση Μελετητή:[ ωτα ] [HTML] Gender, identity and material: Film screening C Brand - 2017 ftypM4V *M4V M4A mp42isom*a┌moovlmvhd...
-
Publication date: September 2017 Source: Free Radical Biology and Medicine, Volume 110 Author(s): Lucía Fernández-del-Río, Anish Nag, Elen...
