bluuebunny/crossref_metadata_2025 huggingface dataset:
Expanding the Scope of Metabolic Glycan Labeling in Arabidopsis thaliana
Authors: Zhu Yuntao , Chen Xing
Published: April 2017

Metabolic glycan labeling (MGL) has gained wide utility and has become a useful tool for probing glycosylation in living systems. For the past three decades, the development and application of MGL have mostly focused on animal glycosylation. Recently, exploiting MGL for studying plant glycosylation has gained interest. Here, we describe a systematic evaluation of MGL for fluorescence imaging of root glycans in Arabidopsis thaliana. Nineteen monosaccharide analogues containing a bioorthogonal group (azide, alkyne, or cyclopropene) were synthesized and evaluated for metabolic incorporation into root glycans. Among these unnatural sugars, 14 (including three new compounds) were evaluated in plants for the first time. Our results showed that five unnatural sugars metabolically labeled root glycans efficiently, and enabled fluorescence imaging by bioorthogonal conjugation with fluorophores. We optimized the experimental procedures for MGL in Arabidopsis. Finally, distinct distribution patterns of the newly synthesized glycans were observed along the root developmental zones, thus indicating regulated biosynthesis of glycans during root development. We envision that MGL will find broad applications in plant glycobiology.
Poly(ethyleneimine)‐tethered Ir Complex Catalyst Immobilized in Titanate Nanotubes for Hydrogenation of CO2 to Formic Acid
Authors: Kuwahara Yasutaka , Fujie Yuki , Yamashita Hiromi
Published: April 2017

Production of formic acid (FA) by hydrogenation of CO2 using a ternary hybrid catalyst, poly(ethyleneimine)‐tethered Ir‐iminophosphine complex (Ir‐PN‐PEI) immobilized in titanate nanotubes (TNTs), is reported. On the basis of comprehensive structural analyses, we show that Ir‐PN‐PEI is tightly immobilized within the cavity space of TNT without affecting the electronic/coordination states of Ir atoms. Liquid‐phase CO2 hydrogenation under pressurized CO2 and H2 demonstrates that the Ir‐PN‐PEI catalyst immobilized in Na+‐type TNT exhibits the highest FA yields (TON>1000 for 20 h under mild reaction conditions (2.0 MPa, 140 °C)) and improved reusability, which far outperform those of unimmobilized prototype Ir‐PN‐PEI. The improved catalytic performance is attributed to the ability of TNT to efficiently capture CO2 and to stabilize PEI, with Na+‐type TNT with higher basic property providing a more productive effect. The catalyst is reusable over multiple cycles with activity comparable to those of heterogeneous catalysts previously reported, rendering this material suitable for efficient transformation of CO2 into FA.
A Bioinspired Organocatalytic Cascade for the Selective Oxidation of Amines under Air
Authors: Largeron Martine , Fleury Maurice‐Bernard
Published: April 2017

A bioinspired organocatalytic cascade reaction for the selective aerobic oxidative cross‐coupling of primary amines to imines is described. This approach takes advantages of commercially available pyrogallol monomeric precursor to deliver low loadings of natural purpurogallin in situ, under air. This is further engaged in a catalytic process with the amine substrate affording, under single turnover, the active biomimetic quinonoid organocatalyst and the homocoupled imine intermediate, which is then converted into cross‐coupled imine after dynamic transimination. This organocatalytic cascade inspired by both purpurogallin biosynthesis and copper amine oxidases allows the aerobic oxidation of non‐activated primary amines that non‐enzymatic organocatalysts were not able to accomplish alone.
Fenton‐RAFT Polymerization: An “On‐Demand” Chain‐Growth Method
Authors: Reyhani Amin , McKenzie Thomas G. , Ranji‐Burachaloo Hadi , Fu Qiang , Qiao Greg G.
Published: April 2017

Fine control over the architecture and/or microstructure of synthetic polymers is fast becoming a reality owing to the development of efficient and versatile polymerization techniques and conjugation reactions. However, the transition of these syntheses to automated, programmable, and high‐throughput operating systems is a challenging step needed to translate the vast potential of precision polymers into machine‐programmable polymers for biological and functional applications. Chain‐growth polymerizations are particularly appealing for their ability to form structurally and chemically well‐defined macromolecules through living/controlled polymerization techniques. Even using the latest polymerization technologies, the macromolecular engineering of complex functional materials often requires multi‐step syntheses and purification of intermediates, and results in sub‐optimal yields. To develop a proof‐of‐concept of a framework polymerization technique that is readily amenable to automation requires several key characteristics. In this study, a new approach is described that is believed to meet these requirements, thus opening avenues toward automated polymer synthesis.
Computational Approach to Measuring Myocyte Disarray in Animal Models of Heart Disease
Authors: Wan William , Leinwand Leslie
Published: April 2017

In cardiovascular disease research, studies often include measuring cardiac function and performing histological examination of heart tissue. After measuring contractility, hearts from animals such as mice and rats are often frozen or fixed, sliced, and stained to quantify the morphology of various structures such as extracellular matrix proteins, cell nuclei, and F‐actin. Traditional scoring methods have largely consisted of assessing sections of images for the presence or absence of myocyte disarray. These approaches require unbiased manual assessment, which can require extra personnel, and are not scalable to the quantity of data that can be generated by modern automated experimental techniques. Here, we describe an automated image analysis approach for unbiased numerical measurement of myocyte disarray. We provide step‐by‐step instructions for image preparation as well as a basic Matlab script for measurements. © 2017 by John Wiley & Sons, Inc.
3 D Network‐Structured Crumpled Graphene/Carbon Nanotube/Polyaniline Composites for Supercapacitors
Authors: Jo Eun H. , Jang Hee D. , Chang Hankwon , Kim Sun K. , Choi Ji‐Hyuk , Lee Chong M.
Published: April 2017

Crumpled graphene (CGR) is considered a promising supercapacitor material to achieve high power and energy density because it could overcome the disadvantages of 2 D GR sheets such as aggregation during the electrode fabrication process, reduction of the available surface area, and limitation of the electron and ion transport. Even though CGR shows good results, carbon materials are limited in terms of their capacitance performance. Here, we report highly enhanced supercapacitor materials by fabricating a 3 D composite containing CGR, carbon nanotubes (CNTs), and polyaniline (PANI). The CNTs increased the basal spacing and bridged the defects for electron transfer between the GR sheets in CGR. PANI can enhance the rate of conduction of electrons and offer high pseudocapacitance originating from its redox reactions. The synergistic effect of the CNTs and PANI may also result in a higher electrochemical capacitance and better stability than each individual component as electrode materials for supercapacitors in a two‐electrode system. More importantly, the performance of the supercapacitors can be further enhanced by employing 2 D GR as the binder for the composite electrodes, resulting in specific capacitance of 456 F g−1, rate capability of 89 %, and cyclic stability of 97 % after 1000 cycles.
Electrical circuits RC, LC, and RL described by Atangana–Baleanu fractional derivatives
Authors: Gómez‐Aguilar J. F. , Atangana Abdon , Morales‐Delgado V. F.
Published: April 2017

In this paper, the analytical solutions for the electrical series circuits RC, LC, and RL using novel fractional derivatives of type Atangana–Baleanu with non‐singular and nonlocal kernel in Liouville–Caputo and Riemann–Liouville sense were obtained. The fractional equations in the time domain are considered derivatives in the range α∈(0;1]; analytical solutions are presented considering different source terms introduced in the fractional equation. We solved analytically the fractional equation using the properties of Laplace transform operator together with the convolution theorem. On the basis of the Mittag–Leffler function, new behaviors for the voltage and current were obtained; the classical cases are recovered when α=1. Copyright © 2017 John Wiley & Sons, Ltd.
RNA sample preparation applied to gene expression profiling for the horse biological passport
Authors: Bailly‐Chouriberry Ludovic , Baudoin Florent , Cormant Florence , Glavieux Yohan , Loup Benoit , Garcia Patrice , Popot Marie‐Agnès , Bonnaire Yves
Published: April 2017

The improvement of doping control is an ongoing race. Techniques to fight doping are usually based on the direct detection of drugs or their metabolites by analytical methods such as chromatography hyphenated to mass spectrometry after ad hoc sample preparation. Nowadays, omic methods constitute an attractive development and advances have been achieved particularly by application of molecular biology tools for detection of anabolic androgenic steroids (AAS), erythropoiesis‐stimulating agent (ESA), or to control human growth hormone misuses. These interesting results across different animal species have suggested that modification of gene expression offers promising new methods of improving the window of detection of banned substances by targeting their effects on blood cell gene expression. In this context, the present study describes the possibility of using a modified version of the dedicated Human IVD (in vitro Diagnostics) PAXgene® Blood RNA Kit for horse gene expression analysis in blood collected on PAXgene® tubes applied to the horse biological passport. The commercial kit was only approved for human blood samples and has required an optimization of specific technical requirements for equine blood samples. Improvements and recommendations were achieved for sample collection, storage and RNA extraction procedure. Following these developments, RNA yield and quality were demonstrated to be suitable for downstream gene expression analysis by qPCR techniques. Copyright © 2017 John Wiley & Sons, Ltd.
Resistance and resilience of root fungal communities to water limitation in a temperate agroecosystem
Authors: Furze Jessie R. , Martin Adam R. , Nasielski Joshua , Thevathasan Naresh V. , Gordon Andrew M. , Isaac Marney E.
Published: April 2017

Understanding crop resilience to environmental stress is critical in predicting the consequences of global climate change for agricultural systems worldwide, but to date studies addressing crop resiliency have focused primarily on plant physiological and molecular responses. Arbuscular mycorrhizal fungi (AMF) form mutualisms with many crop species, and these relationships are key in mitigating the effects of abiotic stress in many agricultural systems. However, to date there is little research examining whether (1) fungal community structure in agroecosystems is resistant to changing environmental conditions, specifically water limitation and (2) resilience of fungal community structure is moderated by agricultural management systems, namely the integration of trees into cropping systems. Here, we address these uncertainties through a rainfall reduction field experiment that manipulated short‐term water availability in a soybean‐based (Glycine max L. Merr.) agroforest in Southern Ontario, Canada. We employed terminal restriction fragment length polymorphism analysis to determine the molecular diversity of both general fungal and AMF communities in soybean roots under no stress, stress (rainfall shelters added), and poststress (rainfall shelters removed). We found that general fungal and AMF communities sampled from soybean roots were resistant to rainfall reduction in a monoculture, but not in an agroforest. While AMF communities were unchanged after stress removal, general fungal communities were significantly different poststress in the agroforest, indicating a capacity for resiliency. Our study indicates that generalist fungi and AMF are responsive to changes in environmental conditions and that agroecosystem management plays a key role in the resistance and resilience of fungal communities to water limitation.
Monocytic myeloid‐derived suppressor cells regulate T‐cell responses against vaccinia virus
Authors: Fortin Carl , Yang Yiping , Huang Xiaopei
Published: April 2017

Vaccinia virus (VV) can potently activate NK‐ and T‐cell responses, leading to efficient viral control and generation of long‐lasting protective immunity. However, immune responses against viral infections are often tightly controlled to avoid collateral damage and systemic inflammation. We have previously shown that granulocytic myeloid‐derived suppressor cells (g‐MDSCs) can suppress the NK‐cell response to VV infection. It remains unknown what regulates T‐cell responses to VV infection in vivo. In this study, we first showed that monocytic MDSCs (m‐MDSCs), but not g‐MDSCs, from VV‐infected mice could directly suppress CD4+ and CD8+ T‐cell activation in vitro. We then demonstrated that defective recruitment of m‐MDSCs to the site of VV infection in CCR2−/− mice enhanced VV‐specific CD8+ T‐cell response and that adoptive transfer of m‐MDSCs into VV‐infected mice suppressed VV‐specific CD8+ T‐cell activation, leading to a delay in viral clearance. Mechanistically, we further showed that T‐cell suppression by m‐MDSCs is mediated by indication of iNOS and production of NO upon VV infection, and that IFN‐γ is required for activation of m‐MDSCs. Collectively, our results highlight a critical role for m‐MDSCs in regulating T‐cell responses against VV infection and may suggest potential strategies using m‐MDSCs to modulate T‐cell responses during viral infections.
Immunoglobulin superfamily members encoded by viruses and their multiple roles in immune evasion
Authors: Farré Domènec , Martínez‐Vicente Pablo , Engel Pablo , Angulo Ana
Published: April 2017

Pathogens have developed a plethora of strategies to undermine host immune defenses in order to guarantee their survival. For large DNA viruses, these immune evasion mechanisms frequently rely on the expression of genes acquired from host genomes. Horizontally transferred genes include members of the immunoglobulin superfamily, whose products constitute the most diverse group of proteins of vertebrate genomes. Their promiscuous immunoglobulin domains, which comprise the building blocks of these molecules, are involved in a large variety of functions mediated by ligand‐binding interactions. The flexible structural nature of the immunoglobulin domains makes them appealing targets for viral capture due to their capacity to generate high functional diversity. Here, we present an up‐to‐date review of immunoglobulin superfamily gene homologs encoded by herpesviruses, poxviruses, and adenoviruses, that include CD200, CD47, Fc receptors, interleukin‐1 receptor 2, interleukin‐18 binding protein, CD80, carcinoembryonic antigen‐related cell adhesion molecules, and signaling lymphocyte activation molecules. We discuss their distinct structural attributes, binding properties, and functions, shaped by evolutionary pressures to disarm specific immune pathways. We include several novel genes identified from extensive genome database surveys. An understanding of the properties and modes of action of these viral proteins may guide the development of novel immune‐modulatory therapeutic tools.
One‐Pot Vinylation of Azlactones: Fast Access to Enantioenriched α‐Vinyl Quaternary Amino Acids
Authors: Serra Massimo , Bernardi Eric , Marrubini Giorgio , Colombo Lino
Published: April 2017

We report a fast one‐pot protocol for the direct vinylation of azlactones [oxazol‐5‐(4H)‐ones] by using as a key step an aldol addition with 2‐(phenylselenenyl)acetaldehyde followed by dehydroxyselenation. The acid hydrolysis of the oxazolone ring gave the desired fully deprotected α‐vinyl quaternary α‐amino acids in almost quantitative yields. An enantioselective variant of the method was also developed by using catalytic chiral bases. The use of Sharpless ligand (DHQD)2PHAL produced the final quaternary amino acids in good overall yields (62–78 %) and with ee values up to 86 %. Scaling up the optimized protocol to gram quantities did not affect the yields and ee values. We also demonstrated that the vinyl moiety installed onto the oxazolone ring can be exploited as a handle for the attachment of aryl groups through a Heck coupling reaction.
Copy number variation in a hospital‐based cohort of children with epilepsy
Authors: Vlaskamp Danique R. M. , Callenbach Petra M. C. , Rump Patrick , Giannini Lucia A. A. , Dijkhuizen Trijnie , Brouwer Oebele F. , van Ravenswaaij‐Arts Conny M. A.
Published: April 2017

Objective

To evaluate the diagnostic yield of microarray analysis in a hospital‐based cohort of children with seizures and to identify novel candidate genes and susceptibility loci for epilepsy.

Methods

Of all children who presented with their first seizure in the University Medical Center Groningen (January 2000 through May 2013) (n = 1,368), we included 226 (17%) children who underwent microarray analysis before June 2014. All 226 children had a definite diagnosis of epilepsy. All their copy number variants (CNVs) on chromosomes 1–22 and X that contain protein‐coding genes and have a prevalence of <1% in healthy controls were evaluated for their pathogenicity.

Results

Children selected for microarray analysis more often had developmental problems (82% vs. 25%, p < 0.001), facial dysmorphisms (49% vs. 8%, p < 0.001), or behavioral problems (41% vs. 13%, p < 0.001) than children who were not selected. We found known clinically relevant CNVs for epilepsy in 24 of the 226 children (11%). Seventeen of these 24 children had been diagnosed with symptomatic focal epilepsy not otherwise specified (71%) and five with West syndrome (21%). Of these 24 children, many had developmental problems (100%), behavioral problems (54%) or facial dysmorphisms (46%). We further identified five novel CNVs comprising four potential candidate genes for epilepsy: MYT1L, UNC5D, SCN4B, and NRXN3.

Significance

The 11% yield in our hospital‐based cohort underscores the importance of microarray analysis in diagnostic evaluation of children with epilepsy.
A generalised finite difference scheme based on compact integrated radial basis function for flow in heterogeneous soils
Authors: Ngo‐Cong D. , Tien C. M. T. , Nguyen‐Ky T. , An‐Vo D.‐A. , Mai‐Duy N. , Strunin D. V. , Tran‐Cong T.
Published: April 2017

In the present paper, we develop a generalised finite difference approach based on compact integrated radial basis function (CIRBF) stencils for solving highly nonlinear Richards equation governing fluid movement in heterogeneous soils. The proposed CIRBF scheme enjoys a high level of accuracy and a fast convergence rate with grid refinement owing to the combination of the integrated RBF approximation and compact approximation where the spatial derivatives are discretised in terms of the information of neighbouring nodes in a stencil. The CIRBF method is first verified through the solution of ordinary differential equations, 2–D Poisson equations and a Taylor‐Green vortex. Numerical comparisons show that the CIRBF method outperforms some other methods in the literature. The CIRBF method in conjunction with a rational function transformation method and an adaptive time‐stepping scheme is then applied to simulate 1–D and 2–D soil infiltrations effectively. The proposed solutions are more accurate and converge faster than those of the finite different method used with a second‐order central difference scheme. Additionally, the present scheme also takes less time to achieve target accuracy in comparison with the 1D‐IRBF and higher order compact schemes.
Stakeholders' views on maternity care shortcomings in rural Ghana: An ethnographic study among women, providers, public, and quasiprivate policy sector actors
Authors: Ayanore Martin Amogre , Pavlova Milena , Biesma Regien , Groot Wim
Published: April 2017

Access to skilled provider and emergency obstetric care is not universal across all districts in Ghana. The lived experiences of 3 stakeholder groups on maternity care shortcomings in 3 rural Ghanaian districts are examined in this study. We applied an ethnographic study approach where field data were collected between March to May 2015 in 3 rural districts of northern Ghana. Data were collected among women with recent births experiences (n = 90), health care providers (n = 16), and policy actors (n = 6). Transcripts were read through to identify similar and divergent stakeholders' views. Significant expressions and experiences of stakeholders on maternity care shortcomings were extracted and evaluated to define key themes. Four themes emerged: social/community factors, payments for health care, facility level factors, and policy level factors. The results show that traditional women's roles divest time for maternity care. Poor transport arrangements, insufficient health workforce, health funding gaps, insurance reimbursements delays, and catastrophic health expenditures on travel and drugs are attested as major barriers across all stakeholder groups in all districts studied. The discussion of the study findings suggests it is important to ascertain the scale of informal payments and their impacts on health access. Investments in health workforce and reliable ambulatory service systems could help address poor referral difficulties in rural areas of the country. Social support for community initiatives that pool funds could provide extra resources and relieve cost access‐related challenges for using maternity care in rural settings in Ghana.
Cattaneo–Christov heat flux model for heat transfer of Marangoni boundary layer flow in a copper–water nanofluid
Authors: Xu Xiaoqin , Chen Shumei
Published: April 2017

The Cattaneo–Christov heat flux is first utilized to explore the heat transfer characteristics of Marangoni boundary layer flow in a copper–water nanofluid. The Marangoni boundary layer flow is driven by exponential temperature. Five different types of nanoparticle shapes including sphere, hexahedron, tetrahedron, column and lamina are considered for the copper–water nanofluid. The nonlinear system of partial differential equations is reduced by similarity transformations and then solved numerically by the shooting method. It is found that sphere nanoparticle has better heat transfer enhancement than other nanoparticle shapes and both the temperature and the thickness of the thermal boundary layer are lower for the Cattaneo–Christov heat flux model than the classical Fourier's law of heat conduction.
Thermal effects of lateral supra‐permafrost water flow around a thermokarst lake on the Qinghai–Tibet Plateau
Authors: You Yanhui , Yu Qihao , Pan Xicai , Wang Xinbin , Guo Lei , Wu Qingbai
Published: April 2017

Both the inflow and outflow of supra‐permafrost water to lakes play important roles in the hydrologic process of thermokarst lakes. The accompanying thermal effects on the adjacent permafrost are required for assessing their influences on the development of thermokarst lakes. For these purposes, the lake water level, temperature dynamics, and supra‐permafrost water flow of a lake were monitored on the Qinghai‐Tibet Plateau. In addition, the spatial and temporal variation of the active layer thickness and permafrost distribution around the lake were investigated by combining ground penetrating radar, electrical resistivity tomography, and borehole temperature monitoring. The results revealed that the yearly unfrozen supra‐permafrost water flow around the lake lasted approximately 5 months. The temperature and water level measurements during this period indicate that the lake water was recharged by relatively colder supra‐permafrost water from the north‐western lakeshore and was discharged through the eastern lakeshore. This process, accompanied by heat exchange with the underlying permafrost, might cause a directional difference of the active layer thickness and permafrost characteristics around the lake. Specifically, the active layer thickness variation was minimal, and the ice‐rich permafrost was found adjacent to the lakeshore along the recharge groundwater pathways, whereas a deeper active layer and ice‐poor permafrost were observed close to the lakeshore from which the warm lake water was discharged. This study suggests that the lateral flow of warm lake water can be a major driver for the rapid expansion of thermokarst lakes and provides clues for evaluating the relationships between the thermokarst expansion process and climate warming.
Diphenyl diselenide protects against methylmercury‐induced inhibition of thioredoxin reductase and glutathione peroxidase in human neuroblastoma cells: a comparison with ebselen
Authors: Meinerz Daiane F. , Branco Vasco , Aschner Michael , Carvalho Cristina , Rocha João Batista T.
Published: April 2017

Exposure to methylmercury (MeHg), an important environmental toxicant, may lead to serious health risks, damaging various organs and predominantly affecting the brain function. The toxicity of MeHg can be related to the inhibition of important selenoenzymes, such as glutathione peroxidase (GPx) and thioredoxin reductase (TrxR). Experimental studies have shown that selenocompounds play an important role as cellular detoxifiers and protective agents against the harmful effects of mercury. The present study investigated the mechanisms by which diphenyl diselenide [(PhSe)2] and ebselen interfered with the interaction of mercury (MeHg) and selenoenzymes (TrxR and GPx) in an in vitro experimental model of cultured human neuroblastoma cells (SH‐SY5Y). Our results established that (PhSe)2 and ebselen increased the activity and expression of TrxR. In contrast, MeHg inhibited TrxR activity even at low doses (0.5 μm). Coexposure to selenocompounds and MeHg showed a protective effect of (PhSe)2 on both the activity and expression of TrxR. When selenoenzyme GPx was evaluated, selenocompounds did not alter its activity or expression significantly, whereas MeHg inhibited the activity of GPx (from 1 μm). Among the selenocompounds only (PhSe)2 significantly protected against the effects of MeHg on GPx activity. Taken together, these results indicate a potential use for ebselen and (PhSe)2 against MeHg toxicity. Furthermore, for the first time, we have demonstrated that (PhSe)2 caused a more pronounced upregulation of TrxR than ebselen in neuroblastoma cells, likely reflecting an important molecular mechanism involved in the antioxidant properties of this compound. Copyright © 2017 John Wiley & Sons, Ltd.
Methylparaben‐induced decrease in collagen production and viability of cultured human dermal fibroblasts
Authors: Majewska Natalia , Zaręba Ilona , Surażyński Arkadiusz , Galicka Anna
Published: April 2017

Parabens owing to their many advantageous properties are widely applied in cosmetics, food products and pharmaceuticals. However, recent research results have shown that they possess the ability to accumulate in the human body and exert many adverse effects. In this study, the impact of methylparaben (MP) as the most frequently used preservative in cosmetics, on human dermal fibroblasts and collagen production was evaluated. In cells treated with 0.01, 0.03 and 0.05% MP a dose‐dependent decrease in collagen biosynthesis was revealed, which was positively correlated with the activity of prolidase responsible for the recovery of proline. Consequently, the concentration of total collagen secreted into the medium was markedly diminished. A similar reduction in expression of the major skin collagen type I at both the protein and mRNA level as well as collagen type III and VI at the mRNA level was also detected. The decrease in the collagen level may result not only from the reduced synthesis but also increased degradation owing to MP‐induced activation of pro‐MMP‐2 (72 kDa). The increase in activity of MMP‐2 (66 kDa) was accompanied by a reduction in the inhibitory activity of TIMP‐2. In addition, an inhibitory effect of MP on cell survival and proliferation was revealed in this study. The increased expression and nuclear translocation of caspase‐3 as well as increased Bax and decreased Bcl‐2 expression may suggest MP‐induced cell apoptosis. In summary, we have provided new data on the adverse effects of methylparaben on human dermal fibroblasts and the main structural protein of the skin. Further studies on the mechanisms responsible for its action are in progress. Copyright © 2017 John Wiley & Sons, Ltd.
Fabrication and characterization of electrospun polycaprolactone and gelatin composite cuffs for tissue engineered blood vessels
Authors: Strobel Hannah A. , Calamari Elizabeth L. , Beliveau Alexander , Jain Anjana , Rolle Marsha W.
Published: April 2017

Sewing cuffs incorporated within tissue‐engineered blood vessels (TEBVs) enable graft anastomosisin vivo, and secure TEBVs to bioreactorsin vitro. Alternative approaches to cuff design are required to achieve cuff integration with scaffold‐free TEBVs during tissue maturation. To create porous materials that promote tissue integration, we used electrospinning to fabricate cuffs from polycaprolactone (PCL), PCL blended with gelatin, and PCL coated with gelatin, and evaluated cuff mechanical properties, porosity, and cellular attachment and infiltration. Gelatin blending significantly decreased cuff ultimate tensile stress and failure strain over PCL alone, but no significant differences were observed in elastic modulus or failure load. Interestingly, gelatin incorporation by blending or coating did not produce significant differences in cellular attachment or pore size. We then created tissue tubes by fusing self‐assembled smooth muscle cell rings together with electrospun cuffs on either end. After 7 days, rings and cuffs fused seamlessly, and the resulting tubes were harvested for pull‐to‐failure tests to measure the strength of cuff–tissue integration. Tubes with gelatin‐coated PCL cuffs failed more frequently at the cuff–tissue interface compared to PCL and PCL:gelatin blended groups. This work demonstrates that electrospun cuffs integrated successfully with scaffold‐free TEBVs, and that the addition of gelatin did not significantly improve cuff integration over PCL alone for this application. Electrospun cuffs may aid cannulation for dynamic culture and testing of tubular constructs during engineered tissue maturation. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 817–826, 2018.
Endoplasmic Reticulum Stress in Mice Increases Hepatic Expression of Genes Carrying a Premature Termination Codon via a Nutritional Status‐Independent GRP78‐Dependent Mechanism
Authors: Harada Nagakatsu , Okuyama Maiko , Yoshikatsu Aya , Yamamoto Hironori , Ishiwata Saori , Hamada Chikako , Hirose Tomoyo , Shono Masayuki , Kuroda Masashi , Tsutsumi Rie , Takeo Jiro , Taketani Yutaka , Nakaya Yutaka , Sakaue Hiroshi
Published: April 2017

Nonsense‐mediated mRNA decay (NMD) degrades mRNAs carrying a premature termination codon (PTC) in eukaryotes. Cellular stresses, including endoplasmic reticulum (ER) stress, inhibit NMD, and up‐regulate PTC‐containing mRNA (PTC‐mRNA) levels in several cell lines. However, whether similar effects exist under in vivo conditions that involve systemic nutritional status is unclear. Here, we compared the effects of pharmacological induction of ER stress with those of nutritional interventions on hepatic PTC‐mRNA levels in mice. In mouse livers, the ER stress inducer tunicamycin increased PTC‐mRNA levels of endogenous marker genes. Tunicamycin decreased body weight and perturbed nutrient metabolism in mice. Food restriction or deprivation mimicked the effect of tunicamycin on weight loss and metabolism, but did not increase PTC‐mRNA levels. Hyperphagia‐induced obesity also had little effect on hepatic PTC‐mRNA levels. Meanwhile, in mouse liver phosphorylation of eIF2α, a factor that regulates NMD, was increased by both tunicamycin and nutritional interventions. Hepatic expression of GRP78, a central chaperone in ER stress responses, was increased by tunicamycin but not by the nutritional interventions. In cultured liver cells (Hepa), exogenous overexpression of a phosphomimetic eIF2α failed to increase PTC‐mRNA levels. However, GRP78 overexpression in Hepa cells increased PTC‐mRNA and PTC‐mRNA‐derived protein levels. ER stress promoted localization of GRP78 to mitochondria, and exogenous expression of a GRP78 fusion protein targeted to mitochondria mimicked the effect of wild type GRP78. These results indicate that GRP78, but not nutritional status, is a potent up‐regulator of hepatic PTC‐mRNA levels during induction of ER stress in vivo. J. Cell. Biochem. 118: 3810–3824, 2017. © 2017 Wiley Periodicals, Inc.
Quantified analysis of histological components and architectural patterns of gleason grades in apparent diffusion coefficient restricted areas upon diffusion weighted MRI for peripheral or transition zone cancer locations
Authors: Helfrich Olivier , Puech Philippe , Betrouni Nacim , Pinçon Claire , Ouzzane Adil , Rizk Jérome , Marcq Gauthier , Randazzo Marco , Durand Matthieu , Lakroum Said , Leroy Xavier , Villers Arnauld
Published: April 2017

Purpose

To quantify and compare the histological components and architectural patterns of Gleason grades in cancerous areas with restriction on apparent diffusion coefficient (ADC) maps.

Materials and Methods

Twelve consecutive cases with 14 separate ADC restriction areas, positive for cancer in the peripheral zone (PZ) and transition zone (TZ) were included. All had 3 Tesla MRI and radical prostatectomy. Ten regions of interest (ROIs) within and outside the 14 ADC restriction areas positive for cancer were selected. For each ROI, we performed quantitative analysis of (a) prostate benign and malignant histological component surface ratios, including stroma, glands, epithelium, lumen, cellular nuclei; (b) percent of Gleason grades and measures of ADC values. Means of histological components according to ADC restriction for cancerous area were compared with analyses of variance with repeated measures.

Results

Independent predictors of the probability of cancer were median epithelium/ROI ratio (P = 0.001) and nuclei/ROI ratio (P = 0.03). Independent predictors of the probability of ADC restriction were malignant glands/ROI and luminal space/ROI (P < 0.0001). Effect of malignant glands/ROI area was different according to the localization of the ROI (P = 0.03). We observed an overall difference between the means for all of the histological components for the comparison of true positive and false negative (P < 0.0001), except for the percent of Gleason grade 4 (P = 0.18). In TZ cancers, a predominant grade 3 pattern was associated with low ADC values. In PZ cancers, a predominant grade 4 pattern was associated with low ADC values.

Conclusion

Determinants of low ADC were high ratio of malignant glands/ROI area which may be seen in Gleason grades 3 or 4 cancers.

Level of Evidence: 3

Technical Efficacy: Stage 3

J. Magn. Reson. Imaging 2017;46:1786–1796.
Investigation of aerosol effects on the Arctic surface temperature during the diurnal cycle: part 1 – total aerosol effect
Authors: Stofferahn Eric , Boybeyi Zafer
Published: April 2017

Temperature changes in the Arctic due to anthropogenic climate change are larger in magnitude than those at lower latitudes, with sea ice extent and thickness diminishing since the dawn of the satellite era. Aerosols may play a vital role in determining these changes, as the radiation reaching the Arctic surface is impacted directly by aerosol absorption and scattering, as well as the ability of aerosols to act as cloud condensation nuclei (CCN) and ice nuclei (IN). This study uses the Weather Research and Forecasting Chemistry (WRF‐Chem) model to show the impact of aerosol absorption, scattering, and CCN contribution on the Arctic surface, with a particular focus on how these effects change throughout the diurnal cycle. Part 1 of this two‐part study investigates the changes in surface temperature, radiation, and cloud properties due to the total aerosol effect in the Arctic. A suite of ensemble runs is used to develop a filtering mechanism based upon the t‐test to eliminate the effects of meteorological variability. While much has been speculated about the cooling role of aerosols, this study shows that aerosols have both a warming and cooling effect. The warming effect is prominent at night, while the cooling effect dominates during the day. In both cases, the magnitude of the effect is dependent upon aerosol concentration.
Future warming rates over the Hawaiian Islands based on elevation‐dependent scaling factors
Authors: Elison Timm Oliver
Published: April 2017

Regional climate change scenarios are important for understanding their impacts on environments of oceanic islands. This study presents a statistical method that estimates elevation‐dependent warming rates for the Hawaiian Islands. The downscaling is facilitated by two important aspects found in the climate change scenarios produced by general circulation models. First, climate model simulations show a strong relationship between height and amplitude of the temperature change over the northern subtropical Pacific. Second, the ratio between the upper air temperature and the surface temperature change is independent of the global warming rate. This information is exploited to produce high‐resolution maps with the expected range of future temperature changes for the Hawaiian Islands by the mid and late 21st century. The expected surface warming and its uncertainty is analysed with an ensemble of global climate scenarios for two Representative Concentration Pathways (RCPs) scenarios (RCP4.5 and 8.5). It is found that the highest mountain elevations warm by a factor 1.5 ± 0.2 compared with the ambient surface temperature anomalies at the sea level. In scenario RCP8.5, high elevations above 3000 m reach up to 4–5 °C warmer temperatures by the late 21st century. The uncertainty due to multi‐model ensemble spread is overall larger than the statistical downscaling uncertainty, except for the highest elevations where both contribute equally to the uncertainty range. For the late 21st century, however, the largest uncertainty stems from the choice of emission scenarios.
Double maturation raisonnée: the impact of on‐vine berry dehydration on the berry and wine composition of Merlot (Vitis vinifera L.)
Authors: Rusjan Denis , Mikulic‐Petkovsek Maja
Published: April 2017

BACKGROUND

Double maturation raisonnée (DMR) is a potential canopy measure that affects grape and wine composition. The aim of this work was to study for the first time the DMR impact on the physical, biochemical and sensorial characteristics of the berries and wines of Merlot, one of the world's fastest‐expanding grapevine varieties.

RESULTS

DMR significantly increased the content of soluble solids (1.2‐fold), free amino nitrogen (1.8‐fold) and acidity in berries but decreased the weight of 100 berries on harvest (approx. 28%). Irrespective of the vintage, DMR‐treated grapes had a significantly higher content of non‐astringent tannins (0.73–0.78 mg L−1) and anthocyanin extractability (34.7–36.4%) but a lower index of astringency (31.2–33.7) when compared to the control. Consequently, the DMR wines achieved higher alcohol, total acidity and extract, hydroxycinnamic acids, flavanol and flavonol contents, whereas the content of anthocyanins was similar to that of the control. Sensorial evaluation showed that DMR wines were not rated higher and would not be appreciated more than control wines.

CONCLUSION

Changes in berries during DMR altered the wine characteristics only in terms of primary metabolites. A reduced accumulation of phenolics, especially anthocyanin content, in the berry skin of DMR‐treated grapes was not reflected in their presence in wines. To the best of our knowledge, this is the first paper that has reported an impact of DMR on the grape and wine composition of Merlot, as one of the most promising red varieties. © 2017 Society of Chemical Industry
The plant growth‐promoting bacterium Kosakonia radicincitans improves fruit yield and quality of Solanum lycopersicum
Authors: Berger Beatrice , Baldermann Susanne , Ruppel Silke
Published: April 2017

BACKGROUND

Production and the quality of tomato fruits have a strong economic relevance. Microorganisms such as the plant growth‐promoting bacterium (PGPB) Kosakonia radicincitans (DSM 16656) have been demonstrated to improve shoot and root growth of young tomato plants, but data on yield increase and fruit quality by K. radicincitans are lacking.

RESULTS

This study investigated how K. radicincitans affects tomato fruits. After inoculation of tomato seeds with K. radicincitans or a sodium chloride buffer control solution, stalk length, first flowering and the amount of ripened fruits produced by inoculated and non‐inoculated plants were monitored over a period of 21 weeks. Inoculation of tomato seeds with K. radicincitans accelerated flowering and ripening of tomato fruits. Sugars, acidity, amino acids, volatile organic compounds and carotenoids in the fruits were also analyzed.

CONCLUSION

It was found that the PGPB K. radicincitans affected the amino acid, sugar and volatile composition of ripened fruits, contributing to a more pleasant‐tasting fruit without forfeiting selected quality indicators. © 2017 Society of Chemical Industry
Preparation of a magnetic porous carbon with hierarchical structures from waste biomass for the extraction of some carbamates
Authors: Wang Yao , Ma Ruiyang , Xiao Ruobai , Wu Qiuhua , Wang Chun , Wang Zhi
Published: April 2017

In this study, corn stalk was used to synthesize a magnetic adsorbent by pyrolysis together with KHCO3 as the chemical activator and iron(III) salt as the magnetic reagent. The characterization by scanning electron microscopy, transmission electron microscopy and N2 adsorption–desorption analysis showed that the magnetic carbon adsorbent had a structure of hierarchical pores with a high specific surface area. To evaluate its adsorption performance, the adsorbent was used for the extraction of carbamates pesticides (propoxur, isoprocarb and fenobucarb) from water and zucchini samples before high‐performance liquid chromatography analysis. The result showed that the adsorbent had a good adsorption capability for the analytes. Under the optimized conditions, a good linearity for the analytes existed in the range of 0.1–100.0 ng/mL for water samples and 0.5–100.0 ng/g for zucchini samples with the correlation coefficients of 0.9992–0.9998. The limits of detection for the analytes at a signal to noise ratio of 3 were 0.03 ng/mL for water samples and 0.20–0.50 ng/g for zucchini samples.
Complexities Surrounding China's Soil Action Plan
Authors: Hou Deyi , Li Fasheng
Published: April 2017

China's soil pollution is serious, with 16·1% of all soil samples exceeding soil quality standard according to a national soil quality survey. On 31 May 2016, the Chinese government unleashed an ambitious plan to address its soil pollution problem. The large scale and fast pace of the proposed plan pose many challenges. There are biogeochemical complexities governing the fate and transport of soil contaminants that require more thorough study. There are also human‐related complexities and dynamic feedback loops, which determine the behaviour of farmers, industrial polluters, remediation practitioners and regulators. Soil pollution prevention and remediation also have externalities and spillover effects ranging from greenhouse gas emission to social justice. Rigorous policy instruments must be developed to account for complex human behaviour, to strengthen risk management and to encourage interdisciplinary scientific research. Copyright © 2017 John Wiley & Sons, Ltd.
Dissolved iron distribution in the western and central subarctic Pacific: HNLC water formation and biogeochemical processes
Authors: Nishioka Jun , Obata Hajime
Published: April 2017

It is well known that phytoplankton growth is broadly limited by iron (Fe) availability in the subarctic Pacific. To investigate which Fe sources control the amplitude of seasonal variation in biogeochemical parameters in the subarctic Pacific, we examined the spatial variation in the west‐to‐east distribution of dissolved Fe (DFe) across the western and central subarctic Pacific through the Japanese GEOTRACES program. The vertical section profile of the western subarctic Pacific gyre showed high dissolved Fe concentrations from the bottom of the surface mixed layer to as deep as approximately 3000 m, suggesting that Fe‐rich intermediate water is transported laterally and distributed across the western subarctic gyre, over 2000 km. The section data also indicate that the influence of the western Fe‐rich intermediate water does not reach the Alaskan gyre. Fe* index (= [DFe] (observed) – [PO4] (observed) × RFe : P) distribution clearly indicates that the western Fe‐rich intermediate water is well explained by external sedimentary Fe sources and water transport systems from a subpolar marginal sea, the Sea of Okhotsk, and the continental margin. The spatial pattern of Fe to nutrient stoichiometry supplied from the intermediate water to the surface, in comparison with reported Fe and nutrient demand in surface phytoplankton, quantitatively explains the differences in surface macronutrient consumption between the western and eastern gyre as well as the formation of the high nutrient and low chlorophyll region in the whole subarctic Pacific.
Photon‐nanosieve for ultrabroadband and large‐angle‐of‐view holograms
Authors: Huang Kun , Liu Hong , Si Guangyuan , Wang Qian , Lin Jiao , Teng Jinghua
Published: April 2017

Holography is of great interest for both scientific research and industry applications, but it has always suffered from the strong dependence on wavelength and polarization of the incident light. Having revisited the Huygens–Fresnel principle, we propose a novel holography mechanism by elaborately choosing discrete point sources (PSs) and realize it experimentally by mimicking the radiated fields of these PSs through carefully designed photon‐nanosieves. Removing the modulation dispersion usually existing in traditional and metasurface holograms, our hologram empowers the simultaneous operation throughout the ultraviolet, entire visible and near‐infrared wavelength regions without polarization dependence. Due to the deep‐subwavelength dimension of nanosieves, this robust hologram offers a large angle‐of‐view of 40°×40° and possesses a lensing effect under a spherical‐wave illumination, which can work as a high‐resolution, lens‐less and distortion‐free microprojector that displays a 260× magnified image. It might open an avenue to a high‐tolerance holographic technique for electromagnetic and acoustic waves.

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Squaraine‐Based Polymers: Toward Optimized Structures for Optoelectronic Devices
Authors: Broggi Alessandra , Kim Hyungsug , Jung Jihye , Bracciale Maria Paola , Santarelli Maria Laura , Kim Choongik , Marrocchi Assunta
Published: April 2017

A novel polymer semiconductor based on squaric acid is successfully prepared through polycondensation reaction. Physicochemical properties of polysquaraine are explored by Fourier transform infrared (FT‐IR) and ultraviolet‐visible (UV‐vis) absorption spectroscopy, thermogravimetric/modulated temperature differential scanning calorimetry (TGA/MTDSC) analyses, and cyclic voltammetry (CV). Next, the charge carrier properties are investigated through the fabrication and characterization of field‐effect transistors (FETs) using solution‐processed polymeric films. It is found that the polysquaraine is FET active and exhibits decent p‐type mobilities (up to 5 × 10−4 cm2 V−1 s−1), which illustrates the promising properties of this semiconductor in optoelectronics. Notably, there is no precedent for the use of squaraine‐based polymers in field‐effect transistors. Bulk heterojunction solar cells (BHJ‐OSCs) are finally prepared from the blends of polysquaraine with the fullerene derivative [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC71BM). Power conversion efficiencies up to 0.86% are achieved for nonoptimized system under simulated air mass 1.5 (AM1.5) conditions.

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