Perovskite solar cells: In pursuit of efficiency and stability

Publication date: 15 December 2017
Source:Materials & Design, Volume 136
Author(s): Jasmin S. Shaikh, Navajsharif S. Shaikh, Arif D. Sheikh, Sawanta S. Mali, Abhijeet J. Kale, Pongsakorn Kanjanaboos, Chang Kook Hong, J.H. Kim, Pramod S. Patil
Perovskite solar cells (PSCs) are coming with positive hopes for researchers to commercialize high-power conversion efficiency (PCE) and low-cost solar cells. Recently, NREL-certified record PCE of PSC is 22.1%, which is competing to silicon solar cells has been reported. However, PSC devices are environmentally sensitive leading to a rapid PCE degradation. Therefore, it is important to understand the impact of the role of various parameters to achieve highly stable PSC without compromising on its performance. This review contains an overview of a recent progress in PSC with respect to PCE, materials engineering, and stability. Energy level diagram of various perovskite materials, electron conducting materials (ECMs) and hole conducting materials (HCMs) constitute pivotal role in selecting their combinations. Hence we have added detailed energy level diagrams from which researcher can select best possible combination to achieve highest efficiency. An in-depth discussion on the types of PSCs based on thin film, mesoporous, n-i-p and p-i-n architectures fabricated by using different deposition techniques has been provided. In order to transfer this exciting achievement to industry level, it is necessary to understand degradation process at different conditions. A detailed discussion on the mechanism of recombination, instability in PSCs and achieved success has been incorporated to apprehend the step-wise developments in this field and to find possible pathways that limit their stability.

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Modeling elevated-temperature mechanical behavior of high and ultra-high strength steels in structural fire design

Publication date: 15 December 2017
Source:Materials & Design, Volume 136
Author(s): Martin Neuenschwander, Claudio Scandella, Markus Knobloch, Mario Fontana
High and ultra-high strength steels are increasingly used in structures of tall and super-tall buildings, where fire safety has a substantial impact on the structural design. However, more widespread employment in engineering practice is substantially impeded by the lack of suitable design models for the constitutive mechanical behavior of such steels at elevated temperatures; and respective available experimental research is limited to investigations of unusually thin plate material with respect to structural applications. The present study completes the current database with an extensive series of strain-rate controlled tensile tests at different strain-rates with coupon specimens from high and ultra-high strength steel plates of varying thickness, and approves on the basis of this novel most comprehensive and consistent database that existing constitutive fire design models for mild carbon steels are only restrictedly adoptable for high strength steels. Analysis of the impact of the revealed model shortcomings at the material level on structural fire designs shows that the model's overestimation of the elevated-temperature yield strength leads to unsafe fire designs of structural applications with strength-induced failure modes, whereas in contrast the model's underestimation of the elevated-temperature Young's modulus leads to occasionally highly overconservative fire designs of structural applications with stability-induced failure modes.

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A molecular dynamics-based analysis of the influence of strain-rate and temperature on the mechanical strength of PPTA crystallites

Publication date: 27 October 2017
Source:Polymer, Volume 129
Author(s): Brian Mercer, Edward Zywicz, Panayiotis Papadopoulos
Molecular dynamic simulations are used to quantify how the mechanical behavior of PPTA crystallites, the fundamental building blocks of aramid fibers such as Kevlar^®, depend on strain-rate, temperature, and crystallite size. The (axial) crystallite elastic modulus is found to be independent of strain-rate and decreases with increasing temperature. The crystallite failure strain increases with increasing strain rate and decreases with increasing temperature and crystallite size. These observations are consistent with crystallite failure being driven by stress-assisted thermal fluctuations of bonds within PPTA crystallites and the concepts of the kinetic theory of fracture. Appealing to reliability theory, a model is proposed that predicts the onset of both primary and secondary bond failure within a crystallite as of function of strain rate, temperature, and crystallite size. The model is parameterized using bond failure data from constant strain-rate molecular dynamic strain-to-failure simulations and is used to compute the activation volume, activation energy, and frequency for both primary and secondary bond ruptures.

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Comparison of chain-growth polymerization in solution versus on surface using reactive coarse-grained simulations

Publication date: 27 October 2017
Source:Polymer, Volume 129
Author(s): Binghui Deng, Edmund F. Palermo, Yunfeng Shi
We developed a reactive coarse-grained model for chain-growth polymerization to study the chain length distribution of polymers grafted from a surface as compared to those grown in solution. The surface-initiated polymer chains exhibit a markedly broader distribution of chain lengths (larger dispersity) and slower chain growth kinetics as compared to the solution phase process. Two key factors that cause deviation from ideal grafting are identified: (1) the formation of chain "loops" with both termini attached to the substrate via recombination and (2) the "starvation" effect, in which the live chain ends of short polymers are sterically shielded from monomers by the presence of longer neighboring chains. Both effects are markedly amplified with increasing initiator surface density, thus limiting the density of high molecular weight chains grafted from the surface. Whereas the "loop" effect is absent in systems that are very strictly "living" (no termination), the starvation effect is likely operative in most real systems. Taken together, these results suggest a theoretical limit on the density of polymer brushes that can form on surfaces by a "grafting-from" technique, based on the kinetics of the chain-growth polymerization process.

Graphical abstract

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Chain mobility, secondary relaxation, and oxygen transport in terephthalate copolyesters with rigid and flexible cyclic diols

Publication date: 27 October 2017
Source:Polymer, Volume 129
Author(s): Krishnan A. Iyer
High glass transition temperature (Tg) polyesters based on cycloaliphatic diols such as 1,4-cyclohexanedimethanol (CHDM) and 2,2,4,4-tetramethyl-1,3-cyclobutanediol (TMCD) have attracted significant interest as bisphenol-A replacement. Whereas most literature reports focus on synthetic approaches, the present study investigates in depth various structure-property relationships in CHDM- and TMCD-containing novel copolyesters. Significant enhancements in Tg and increases in fragility are observed with the incorporation of bulky CHDM and rigid TMCD as comonomers. Substantial increase in oxygen permeability is measured with the incorporation of CHDM from 14.3 for poly(ethylene terephthalate) to 52.6 cc-mil/100in².day.atm (SPU) for poly(1,4-cyclohexyldimethylene terephthalate). When 35 mol% CHDM is replaced by TMCD as comonomer, the value further increases to 137.0 SPU. In the case of CHDM-containing polyesters, improvements in both sub-Tg molecular mobility (due to additional chair-to-boat transformations) and fractional free volume (FFV) result in an increase in oxygen diffusion. On the other hand, substituting 35 mol% CHDM with more rigid TMCD yields a suppressed β-relaxation. In particular, CHDM-based copolyesters follow a linear correlation between the strength of β-relaxation and diffusivity whereas the TMCD-based copolyester exhibits a significantly positive deviation from the correlation. Therefore, the much higher FFV in TMCD-containing polyester plays a more important role in determining oxygen transport through such polymer. Finally, we demonstrate that copolyesters based on CHDM and TMCD display significantly enhanced resistance to moisture-induced plasticization and the competing penetrant effect.

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Effect of anisotropic thermal expansion on the torsional actuation of twist oriented polymer fibres

Publication date: 27 October 2017
Source:Polymer, Volume 129
Author(s): Shazed Aziz, Sina Naficy, Javad Foroughi, Hugh R. Brown, Geoffrey M. Spinks
Torsional actuation of twisted polymer fibres is the basis for high performance tensile actuation when these fibres are formed into coils. The thermally-induced torsional actuation of twisted polyamide-6 fibres can be predicted by a single helix approximation when the measured diameter and length direction thermal expansion coefficients are known. The single helix model illustrates the sensitivity of the magnitude of torsional actuation to the volume expansion anisotropy for a given volume change. The applicability of the model has been further assessed by investigating three polymer fibres that display different thermal expansion anisotropies. Commercially available polyethylene, polypropylene and polyamide-6 fibres were twisted to the maximum extent without coiling and then heat treated to fix the twisted structure. Heating the twisted fibres between 26 and 62 °C resulted in a partial untwist which was reversed during cooling. The single-helix model of the twisted fibres was used to accurately predict the torsional stroke based on the measured fibre length and diameter change during heating. Comparative torsional stroke of twisted polyamide-6, polyethylene and polypropylene was explained in terms of materials thermo-physical properties. Generated blocked torques was also correctly predicted by the single-helix model when combined with the measured fibre torsional stiffness. Variances between torsional stiffnesses were found to be dependent of different anisotropic thermal properties of tested fibres.

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Functional polyethylene with regularly distributed ester pendants via ring-opening metathesis polymerization of ester functionalized cyclopentene: Synthesis and characterization

Publication date: 27 October 2017
Source:Polymer, Volume 129
Author(s): Shaofei Song, Zhenyan Xing, Zhenmei Cheng, Zhisheng Fu, Junting Xu, Zhiqiang Fan
A new series of functional polyethylene (PE) with ester pendant (−COOR, R = methyl, ethyl, n-propyl, n-butyl, n-octyl, n-dodecyl, n-tetradecyl and n-hexadecyl) on every five main chain carbons were prepared via ring-opening metathesis polymerization (ROMP) of COOR functionalized cyclopentene catalyzed by a ruthenium-based catalyst and subsequent hydrogenation of the ROMP products. High monomer conversions (70–80%) were achieved in all the ROMP reactions. Chain structure, molecular weight and molecular weight distribution (MWD) of the ROMP products and hydrogenated polymers were characterized by ¹H, ¹³C NMR and GPC, which showed regular distribution of the COOR pendants along the main chain, moderate molecular weight and narrow MWD. Thermal properties and side chain crystallization behaviors of the functional PEs were investigated by differential scanning calorimetry (DSC). Glass transition temperature (Tg) of the polymer decreased for nearly 30 °C when R of the pendant COOR was enlarged from methyl to n-octyl, and the new polymers showed lower melting temperature (Tm), higher side chain crystallinity (Xc) and more precise side chain lamellar crystal thickness (lc) as compared with corresponding polyacrylates carrying the same side alkyl. The new polymers exhibited moderate thermal stability.

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Associations between oral hygiene habits, diet, tobacco and alcohol and risk of oral cancer: A case–control study from India

Publication date: December 2017
Source:Cancer Epidemiology, Volume 51
Author(s): Bhawna Gupta, Freddie Bray, Narinder Kumar, Newell W Johnson
ObjectiveThis study examines the association between the incidence of oral cancer in India and oral hygiene habits, diet, chewing and smoking tobacco, and drinking alcohol. We also assessed the effects of oral hygiene habits with oral cancer risk among chewers versus never chewers.MethodsA hospital-based case–control study was conducted in Pune, India, based on face-to-face interviews, anthropometry, and intra-oral examinations conducted for 187 oral cancer cases and 240 controls.ResultsPoor oral hygiene score was associated with a significant risk of oral cancer (adjusted OR=6.98; 95%CI 3.72–13.05). When stratified by tobacco-chewing habit, the poor oral hygiene score was a significant risk factor only among ever tobacco chewers (adjusted OR=14.74; 95%CI 6.49–33.46) compared with never chewers (adjusted OR=0.71; 95%CI 0.14–3.63). Dental check-ups only at the time of pain by ever-chewers with poor oral hygiene was associated with an elevated risk (adjusted OR=4.22; 95%CI 2.44–7.29), while consumption of green, yellow, and cruciferous vegetables and citrus fruits was protective. A linear dose–response association was observed between oral cancer and chewing tobacco in terms of age at initiation, duration, and frequency of chewing per day (P<0.001). Smoking more than 10 bidis/cigarettes per day (adjusted OR=2.74; 95%CI 1.28–5.89) and for a duration >25 years (adjusted OR=2.31; 95%CI 1.14–4.71) elevated the risk of oral cancer.ConclusionGood oral hygiene habits – as characterized by healthy gums, brushing more than once daily, use of toothpaste, annual dental check-ups, and a minimal number of missing teeth – can reduce the risk of oral cancer significantly. In addition to refraining from chewing/smoking tobacco, a diet adequate in fruits and vegetables may protect against the disease.

Graphical abstract

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Vaccination with a recombinant OprL fragment induces a Th17 response and confers serotype-independent protection against Pseudomonas aeruginosa infection in mice

Publication date: Available online 29 September 2017
Source:Clinical Immunology
Author(s): Chen Gao, Feng Yang, Ying Wang, Yaling Liao, Jinyong Zhang, Hao Zeng, Quanming Zou, Jiang Gu
Pseudomonas aeruginosa (PA) is the major causative agent of nosocomial infection. Despite of adequate use of antibiotics, it still represents a major challenge in controlling PA infection. The local pulmonary Th17 response plays an important protective role against PA infection. And the Th17-mediated protection is antibody independent, so we hypothesized that it would be an optimal strategy of a vaccine for PA control to induce an effective Th17 response. Herein we report the successful production of a recombinant fragment of the OprL (reOprL) of PA. Purified reOprL forms homogeneous monomers in solution and vaccination with reOprL elicited a remarkable Th17 response. In addition, reOprL vaccination conferred effective serotype-independent protection against PA infection, which relied on the Th17 response. Our data suggest that reOprL is a good candidate for the future development of Th17 immunity based PA vaccines.



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Overestimation of orthophosphate monoesters in lake sediment by solution 31 P-NMR analysis

Abstract

Solution ³¹P nuclear magnetic resonance spectroscopy (³¹P-NMR) is a useful method for analyzing organic phosphorus (P_o). Unfortunately, the extraction conditions, which are highly alkaline and require long extraction times, make this analysis less effective. In this research, according to the lability of orthophosphate monoesters (mono-P_o) and orthophosphate diesters (diesters-P_o), we verified the hypothesized overestimation of mono-P_o in lake sediment using solution ³¹P-NMR. We set three scenes to redistribute the mono-P_o and diesters-P_o. Six components, including eight mono-P_o species, were detected in the NaOH–EDTA extracts of sediment samples using ³¹P-NMR. The results showed that mono-P_o (212.7 mg kg⁻¹) was the dominant P_o in the surface sediment. In the three scenes, mono-P_o decreased from 212.7 to 112.0 mg kg⁻¹, and diesters-P_o increased from 31.9 to 132.7 mg kg⁻¹. The ratio of mono-P_o to diesters-P_o increased from 6.7 to 0.8. Therefore, we deduced that the concentration of mono-P_o was overestimated, while that of diesters-P_o was underestimated, in most research because of the high pH and long extraction process. Diesters-P_o might be an important labile P source during the P "exhausted" period.

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Inhibition of Phytophthora species, agents of cocoa black pod disease, by secondary metabolites of Trichoderma species

Abstract

Cocoa production is affected by the black pod disease caused by several Phytophthora species that bring, about each year, an estimated loss of 44% of world production. Chemical control remains expensive and poses an enormous risk of poisoning for the users and the environment. Biocontrol by using antagonistic microorganisms has become an alternative to the integrated control strategy against this disease. Trichoderma viride T7, T. harzanium T40, and T. asperellum T54, which showed in vivo and in vitro antagonistic activity against P. palmivora, were cultured and mycelia extracted. Inhibition activity of crude extracts was determined, and then organic compounds were isolated and characterized. The in vitro effect of each compound on the conidia germination and mycelia growth of four P. palmivora, two P. megakaria, and one P. capsici was evaluated. T. viride that displayed best activities produced two active metabolites, viridin and gliovirin, against P. palmivora and P. megakaria strains. However, no activity against P. capsici was observed. Besides being active separately, these two compounds have a synergistic effect for both inhibitions, mycelia growth and conidia germination. These results provide the basis for the development of a low-impact pesticide based on a mixture of viridin and gliovirine.

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Phytoremediation potential of moso bamboo ( Phyllostachys pubescens ) intercropped with Sedum plumbizincicola in metal-contaminated soil

Abstract

This study was conducted to investigate the capability of moso bamboo grown alone and in combination with Sedum plumbizincicola to remediate heavy metals. Monoculture of moso bamboo (MM), intercropping of moso bamboo × S. plumbizincicola (IMS), and control (uncultivated, CK) were established in Cu-, Zn-, and Cd-contaminated soil. Soil properties and heavy metal removal capacity were assessed. Results showed that the available and total heavy metal contents in soil (0–20 and 20–40 cm soil layers) were ranked IMS < MM < CK. Available Cu, Zn, and Cd contents were 65.0, 28.7, and 48.4% lower in the IMS and 52.8, 24.8, and 45.5% lower in the MM than those in the CK, respectively. In plants, Cu contents in bamboo rhizomes, branches, and leaves and those of Zn and Cd in all bamboo tissues were significantly higher in the IMS than in the MM. The bioconcentration and translocation factors of bamboo tissues showed an obviously increasing tendency from MM to IMS. Moso bamboo possessed the properties of endurance to heavy metals and high biomass production. Phytoremediation by moso bamboo in association with S. plumbizincicola is an economical strategy to promote heavy metal removal from metal-contaminated soil.

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Rapid biosynthesized AgNPs from Gelidiella acerosa aqueous extract mitigates quorum sensing mediated biofilm formation of Vibrio species—an in vitro and in vivo approach

Abstract

The present study explores the non-bactericidal anti-virulence efficacy of green synthesized silver nanoparticles (AgNPs) from Gelidiella acerosa against multi-drug resistant Vibrio spp. Spectral characterization of AgNPs was performed through UV-Visible, FT-IR, and energy-dispersive spectroscopic techniques followed by X-ray crystallography and zeta potential analysis. Further, the structural characterization was done by electron and atomic force microscopic techniques. AgNPs profoundly quelled the quorum sensing mediated violacein production in Chromobacterium violaceum and CV026. Characterized AgNPs at 100 μg mL⁻¹ concentrations depicted a phenomenal anti-biofilm efficacy against Vibrio parahaemolyticus (71%) and Vibrio vulnificus (83%) biofilms, which was further confirmed through light, confocal, and scanning electron microscopic analyses. In vitro bioassays revealed the remarkable inhibitory values of AgNPs, by inhibiting the exopolysaccharide production, hydrophobicity, and motility. In vivo studies using Artemia franciscana larvae also confirmed the anti-infective proficiency, as the AgNPs effectively reduced the bacterial colonization and enhanced the survival rate of larvae up to 100% without any toxicity effect.

Graphical abstract

Rapid biosynthesized AgNPs from Gelidiella acerosa quench quorum sensing controlled virulence traits in vibrios

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The Croton megalobotrys Müll Arg. traditional medicine in HIV/AIDS management: Documentation of patient use, in vitro activation of latent HIV-1 provirus, and isolation of active phorbol esters

Publication date: Available online 29 September 2017
Source:Journal of Ethnopharmacology
Author(s): Ian Tietjen, Barbara N. Ngwenya, Ghislain Fotso, David E. Williams, Sundana Simonambango, Bonaventure T. Ngadjui, Raymond J. Andersen, Mark A. Brockman, Zabrina L. Brumme, Kerstin Andrae-Marobela
Ethnopharmacological relevanceCurrent HIV therapies do not act on latent cellular HIV reservoirs; hence they are not curative. While experimental latency reversal agents (LRAs) can promote HIV expression in these cells, thereby exposing them to immune recognition, existing LRAs exhibit limited clinical efficacy and high toxicity. We previously described a traditional 3-step medicinal plant regimen used for HIV/AIDS management in Northern Botswana that inhibits HIV replication in vitro. Here we describe use of one component of the regimen that additionally contains novel phorbol esters possessing HIV latency-reversal properties.Aim of the studyWe sought to document experiences of traditional medicine users, assess the ability of traditional medicine components to reverse HIV latency in vitro, and identify pure compounds that conferred these activities.Materials and methodsExperiences of two HIV-positive traditional medicine users (patients) were documented using qualitative interview techniques. Latency reversal activity was assessed using a cell-based model (J-Lat, clone 9.2). Crude plant extracts were fractionated by open column chromatography and reverse-phase HPLC. Compound structures were elucidated using NMR spectroscopy and mass spectrometry.ResultsPatients using the 3-step regimen reported improved health over several years despite no reported use of standard HIV therapies. Crude extracts from Croton megalobotrys Müll Arg. ("Mukungulu"), the third component of the 3-step regimen, induced HIV expression in J-lat cells to levels comparable to the known LRA prostratin. Co-incubation with known LRAs and pharmacological inhibitors indicated that the active agent(s) in C. megalobotrys were likely to be protein kinase C (PKC) activator(s). Consistent with these results, two novel phorbol esters (Namushen 1 and 2) were isolated as abundant components of C. megalobotrys and were sufficient to confer HIV latency reversal in vitro.ConclusionWe have identified novel LRAs of the phorbol ester class from a medicinal plant used in HIV/AIDS management. These data, combined with self-reported health effects and previously-described in vitro anti-HIV activities of this traditional 3-step regimen, support the utility of longitudinal observational studies of patients undergoing this regimen to quantify its effects on plasma viral loads and HIV reservoir size in vivo.

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Leishmanicidal activity of the Root Bark of Erythrophleum Ivorense (Fabaceae) and Identification of some of its compounds by Ultra-Performance Liquid Chromatography Quadrupole Time of Flight Mass Spectrometry (UPLC-QTOF-MS/MS)

Publication date: Available online 29 September 2017
Source:Journal of Ethnopharmacology
Author(s): Francis A. Armah, Isaac K. Amponsah, Abraham Y. Mensah, Rita A. Dickson, Paul A. Steenkamp, Ntakadzeni E. Madala, Christian K. Adokoh
Ethnopharmacological relevanceLeishmaniasis is one of the neglected tropical disease caused by a protozoan of the genus Leishmania transmitted by sandflies. High cost and lack of oral formulation of existing drugs, rapid developments of resistance by the parasite coupled with serious side effects require new treatments to augment or replace currently available therapies. The major merits of herbal medicine seem to demonstrate perceived efficacy, low incidence of serious adverse effects and low cost. Erythrophleum plants possess beneficial biological properties and, as such, characterization of the bioactive components of these plants is imperative. Previous work has shown an overwhelming presence of cassaine alkaloids in these plants. However, amongst these plants, the African based specie (Erythrophleum ivorense) is the least studied.ObjectiveIn the current study, the in vitro anti-leishmanial activity of the crude extract, its fractions and isolated compounds were evaluated using direct counting assay of promastigotes of Leishmania donovani using amphotericin B as positive control.Materials and methodsThe anti-leishmanial activity of E. ivorense extract was evaluated in vitro against the promastigote forms of Leishmania Donovani using a direct counting assay based on growth inhibition. Different crude extracts from ethyl acetate, pet-ether, and methanol as well as pure isolated compounds of E. ivorense: Erythroivorensin, Eriodictyol and Betulinic acid were screened. To know the possible components of the active methanolic extract, attempt was made to elucidate the extract using ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UHPLC-QTOF-MS/MS).ResultsThis afforded a weak pet-ether fraction, a moderately active ethyl acetate fraction and a significantly active methanol fraction (IC50 = 2.97μg/mL) compared to Amphotericin B (IC50 = 2.40±0.67μg/mL). The novel diterpene erythroivorensin, betulinic acid and the flavanone Eriodictyol, from the ethyl acetate fraction, showed weak activity. UPLC-QTOF-MS/MS was used to identify the cassaine diterpenoids from the active methanol fraction. Here, 10 compounds of this type were putatively identified from the ethanol crude extract.ConclusionThe fragmentation mechanism of these metabolites is also proposed and are expected to serve as reference template for identification of these and related compounds in future. The presence of these compounds is an indication that they are an inherited and evolutionary component of plants belonging to the Erythrophleum genus. Our results further present another dimension where these compounds and their relative abundances can be used as chemo-taxonomical bio-markers of the genus. The present study also successfully demonstrated/re-affirmed the use of UPLC-QTOF-MS/MS as a robust technique for the characterization of natural products.

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In vitro multimodal-effect of Trichilia catigua A. Juss. (Meliaceae) bark aqueous extract in CNS targets

Publication date: Available online 29 September 2017
Source:Journal of Ethnopharmacology
Author(s): João Bernardo, Federico Ferreres, Ángel Gil-Izquierdo, Romeu António Videira, Patrícia Valentão, Francisco Veiga, Paula B. Andrade
Ethnopharmacological relevanceThe bark of Trichilia catigua A. Juss. (Meliaceae), popularly known as "big catuaba", is traditionally used in Brazilian folk medicine for its neuroactive potential as memory stimulant, and antinociceptive and antidepressant effects.Aim of the studyTo study the aqueous extract of T. catigua bark as dual inhibitor of monoamine oxidase A (MAO-A) and acetylcholinesterase (AChE). To explore its antioxidant potential through interaction with xanthine/xanthine oxidase (X/XO) pathway, and to attempt a relationship between its phenolic profile and effects displayed.Materials and methodsPhenolic profiling was achieved by HPLC-DAD-ESI/MSⁿ and UPLC-ESI-QTOF-MS analyses. The capacity to inhibit hMAO-A was assessed in vitro, as was that for AChE, evaluated in rat brain homogenates. The direct inhibition of the X/XO pathway and the scavenging of superoxide anion radical were the selected in vitro models to explore the antioxidant potential. The cytotoxic effects were assayed with the human neuronal SH-SY5Y cells by MTT reduction, after direct exposure (24h).ResultsTwenty-six compounds were identified and quantified (551.02 ± 37.61mg/g of lyophilized extract). The phenylpropanoid substituted flavan-3-ols were the most representative compounds (~81% of quantified mass). The extract inhibited hMAO activity in a concentration-dependent manner (IC50 = 121.06 ± 2.13 μg/mL). A mixed model of inhibition of AChE activity was observed, reflected by the pronounced increase of Km values and a more discreet effect over the Vmax parameters, calculated from Michaelis-Menten fitted equations. In addition, it was demonstrated that the extract directly inhibits the X/XO pathway (IC50 = 121.06 ± 2.13 μg/mL) and also imbalance the oxidative stress acting as superoxide anion radical scavenger (EC50 = 104.42 ± 10.67 μg/mL), an oxidative by-product of this reaction. All these neuroprotective and neurotrophic effects were displayed within the non-toxic range of concentrations (0.063–0.500 μg/mL) in SH-SY5Y cells.ConclusionsOur results validate the traditional use of T. catigua bark for its neuroactive and neuroprotective potential. A novel approach upon its application towards the management of neurodegenerative and related symptomatology was likewise demonstrated.

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Anti-Inflammatory effects of Perillae Herba ethanolic extract against TNF-α/IFN-γ-stimulated human keratinocyte HaCaT cells

Publication date: Available online 29 September 2017
Source:Journal of Ethnopharmacology
Author(s): Ju-Hye Yang, Jae-Myung Yoo, Esther Lee, BoHyoung Lee, Won-Kyung Cho, Kwang-Il Park, Jin Yeul Ma
Ethnopharmacological relevancePerillae Herba is a perennial plant that is widely distributed throughout Asia. The leaves of Perillae Herba have been widely used to treat various diseases, such as cold due to wind-cold, headache, cough, abdominal fullness, distention, and fish and crab poisoning.Materials and MethodsTo assess the anti-inflammatory activity of Perillae Herba leaf ethanolic extract (PHE) in human keratinocytes, we measured the tumor necrosis factor (TNF)-α/interferon (IFN)-γ-induced mRNA expression and production of proinflammatory chemokines such as thymus and activation-regulated chemokines; regulated on activation, normal T cell expressed and secreted; interleukin (IL)−6; and IL-8 in HaCaT cells. We evaluated the ability of PHE to decrease the expression of proinflammatory marker proteins, such as mitogen-activated protein kinase (MAPK), STAT-1, and NK-κB, using western blot analysis and immunocytochemistry.ResultsPHE inhibited activation of p38, ERK, and JNK and suppressed the phosphorylation of STAT-1 and NK-κB in TNF-α/IFN-γ-stimulated HaCaT cells. PHE also suppressed chemokine mRNA and protein levels in TNF-α/IFN-γ-stimulated HaCaT cells. PHE appears to regulate chemokine formation by inhibiting activation of MAPK, as well as the STAT-1 and NK-κB pathways.ConclusionsPHE suppresses the expression and production of TNF-α/IFN-γ-stimulated proinflammatory chemokines by blocking NF-κB, STAT-1, and MAPK activation.

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Systems analysis of singly and multiply O-glycosylated peptides in the human serum glycoproteome via EThcD and HCD mass spectrometry

Publication date: Available online 29 September 2017
Source:Journal of Proteomics
Author(s): Yong Zhang, Xinfang Xie, Xinyuan Zhao, Fang Tian, Jicheng Lv, Wantao Ying, Xiaohong Qian
Human serum has been intensively studied to identify biomarkers via global proteomic analysis. The altered O-glycoproteome is associated with human pathological state including cancer, inflammatory and degenerative diseases and is an attractive source of disease biomarkers. Because of the microheterogeneity and macroheterogeneity of O-glycosylation, site-specific O-glycosylation analysis in human serum is still challenging. Here, we developed a systematic strategy that combined multiple enzyme digestion, multidimensional separation for sample preparation and high-resolution tandem MS with Byonic software for intact O-glycopeptide characterization. We demonstrated that multiple enzyme digestion or multidimensional separation can make sample preparation more efficient and that EThcD is not only suitable for the identification of singly O-glycosylated peptides (50.3%) but also doubly (21.2%) and triply (28.5%) O-glycosylated peptides. Totally, with the strict scoring criteria, 499 non-redundant intact O-glycopeptides, 173 O-glycosylation sites and 6 types of O-glycans originating from 49 O-glycoprotein groups were identified in human serum, including 121 novel O-glycosylation sites. Currently, this is the largest data set of site-specific native O-glycoproteome from human serum samples. We expect that the strategies developed by this study will facilitate in-depth analyses of native O-glycoproteomes in human serum and provide opportunities to understand the functional roles of protein O-glycosylation in human health and diseases.Biological significanceThe altered O-glycoproteome is associated with human pathological state and is an attractive source of disease biomarkers. However, site-specific O-glycosylation analysis is challenging because of the microheterogeneity (different glycoforms attached to one glycosylation site) and macroheterogeneity (site occupancy) of O-glycosylation.In this work, we developed a systematic strategy for intact O-glycopeptide characterization. This study took advantage of the inherent properties of the new fragmentation method called EThcD, which provides more complete fragmentation information about O-glycosylated peptides and a more confident site localization of O-glycans than collision-induced dissociation (HCD). We demonstrated that multiple enzyme digestion or multidimensional separation can make sample preparation more efficient and that EThcD was not only suitable for the identification of singly O-glycosylated peptides (50.3%) but also doubly (21.2%) and triply (28.5%) O-glycosylated peptides. Finally, we got a largest data set of site-specific native O-glycoproteome from human serum samples. Furthermore, quantitative analysis of intact O-glycopeptides from the serum samples of IgA nephropathy (IgAN) patients and healthy donors was performed, and the results showed the potential of the strategy to discover O-glycosylation biomarkers.We expect that the strategies developed by this study will facilitate in-depth analyses of native O-glycoproteomes in human serum and lead to exciting opportunities to understand the functional roles of protein O-glycosylation in human health and diseases.

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Scholar : These new articles for Computer-Aided Design and Applications are available online

The online platform for Taylor & Francis Online content New for Computer-Aided Design and Applications and online now on Taylor & Francis Online: Original Articles Parametric comparing for local inspection of industrial plants by using as-built model acquired from laser scan data Cong Hong Phong Nguyen & Young Choi Pages: 1-9 | DOI: 10.1080/16864360.2017.1375675 Read selected content from the Journal of Structural Integrity and Maintenance for free! http://ift.tt/2coiFom To update which email alerts you receive, manage your alerts within the My Account area. You can also unsubscribe from this alert with one click. If you need any further help, please contact us at support@tandfonline.com Please do not reply to this email. To ensure that you receive your alerts and information from Taylor & Francis Online, please add "alerts@tandfonline.com" and "info@tandfonline.com" to your safe senders list. Taylor & Francis, an Informa business. Taylor & Francis is a trading name of Informa UK Limited, registered in England under no. 1072954. Registered office: 5 Howick Place, London, SW1P 1WG.

Scholar : Xenobiotica, Volume 47, Issue 11, November 2017 is now available online on Taylor & Francis Online

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The online platform for Taylor & Francis Online content Xenobiotica, Volume 47, Issue 11, November 2017 is now available online on Taylor & Francis Online. This new issue contains the following articles: General Xenobiochemistry Assessment of liver slices for research on metabolic drug–drug interactions in cattle Paula Viviani, Adrián L. Lifschitz, Jorge P. García, María Laura Maté, Miguel A. Quiroga, Carlos E. Lanusse & Guillermo L. Virkel Pages: 933-942 | DOI: 10.1080/00498254.2016.1246782 Stereoselective hepatic disposition of ibuprofen in the perfused liver of rat with adjuvant-induced arthritis Misato Uraki, Atsushi Kawase & Masahiro Iwaki Pages: 943-950 | DOI: 10.1080/00498254.2016.1252869 Functional expression and comparative characterization of four feline P450 cytochromes using fluorescent substrates Gaku Okamatsu, Kei Kawakami, Tetsuya Komatsu, Takio Kitazawa, Yasuhiro Uno & Hiroki Teraoka Pages: 951-961 | DOI: 10.1080/00498254.2016.1257172 Animal Pharmacokinetics and Metabolism Evaluation of the metabolism, bioactivation and pharmacokinetics of triaminopyrimidine analogs toward selection of a potential candidate for antimalarial therapy Abhishek Srivastava, Vijender Panduga, Ramanatha Saralaya, Prabhakar K. R., Shahul Hameed, Suresh Solapure & Vinayak P. Hosagrahara Pages: 962-972 | DOI: 10.1080/00498254.2016.1247481 Effect of ferulic acid on the brain pharmacokinetics of tetramethylpyrazine in conscious rats Yinai Wu , Fengyun Liao, Weiguo Liao, Jianye Yu, Xingyun Deng, Huazhu Zheng, YingJiao Meng & Lisheng Wang Pages: 973-979 | DOI: 10.1080/00498254.2016.1257835 Excretion and toxicity evaluation of 131I-Sennoside A as a necrosis-avid agent Zhiqi Yin, Lidan Sun, Qiaomei Jin, Shaoli Song, Yuanbo Feng, Hong Liao, Yicheng Ni, Jian Zhang & Wei Liu Pages: 980-988 | DOI: 10.1080/00498254.2016.1258740 Xenobiotic Transporters Differential regulation of intestinal efflux transporters by pregnancy in mice Jamie E. Moscovitz, Gabriel Yarmush, Guadalupe Herrera-Garcia, Grace L. Guo & Lauren M. Aleksunes Pages: 989-997 | DOI: 10.1080/00498254.2016.1250292 Multidrug and toxin extrusion protein 1-mediated interaction of metformin and Scutellariae radix in rats Sreymom Yim, Byoung Hoon You, Hee-Sung Chae, Young-Won Chin, Hojun Kim, Han Seok Choi & Young Hee Choi Pages: 998-1007 | DOI: 10.1080/00498254.2016.1257836 ABCC2 (1249G > A) polymorphism implicates altered transport activity for sorafenib Danyun Wei, Hong Zhang, Rui Peng, Cuiyuan Huang & Ruidan Bai Pages: 1008-1014 | DOI: 10.1080/00498254.2016.1262976 Topics in Xenobiochemistry Comparative pharmacokinetics of three SGLT-2 inhibitors sergliflozin, remogliflozin and ertugliflozin: an overview Ranjeet Prasad Dash, R. Jayachandra Babu & Nuggehally R. Srinivas Pages: 1015-1026 | DOI: 10.1080/00498254.2016.1247219 To update which email alerts you receive, manage your alerts within the My Account area. You can also unsubscribe from this alert with one click. If you need any further help, please contact us at support@tandfonline.com Please do not reply to this email. To ensure that you receive your alerts and information from Taylor & Francis Online, please add "alerts@tandfonline.com" and "info@tandfonline.com" to your safe senders list. Taylor & Francis, an Informa business. Taylor & Francis is a trading name of Informa UK Limited, registered in England under no. 1072954. Registered office: 5 Howick Place, London, SW1P 1WG.