bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flower‐Like Multicompartment Micelles with Janus‐Core Self‐Assembled from Fluorocarbon‐Terminated Pluronics
Authors: Liu Hengchang , Feng Yujun 
Published: February 2018

AbstractMulticompartment micelles (MCMs), whose cores have at least two compartments, show potential applications in various areas, but the synthesis of polymers for preparing MCMs is usually tedious and time‐consuming. In this work, two well‐defined telechelic fluorocarbon‐terminated triblock copolymers, F8‐PEO100‐PPO65‐PEO100‐F8 (F8‐F127‐F8) and F8‐PEO132‐PPO50‐PEO132‐F8 (F8‐F108‐F8), are synthesized via a single‐step coupling reaction of Pluronics F127 or F108 with perfluoro‐1‐octanesulfonyl fluoride and characterized by Fourier‐transform infrared and NMR spectroscopies, as well as gel permeation chromatography and surface tensiometry. Both of these fluorocarbon‐terminated Pluronics can self‐assemble into spherical MCMs with Janus‐core in aqueous solution, as evidenced by transmission electron microscopy imaging. Since the lipophilic block (PPO) and fluorophilic segments (F8) are separated by the hydrophilic blocks (PEO), these fluorocarbon‐terminated Pluronics will loop to give rise to flower‐like MCMs, and the calculations based on thermodynamics and dynamics support the formation of such unique aggregates. A “pre‐self‐assembly” mechanism is proposed to explain the formation process of flower‐like MCMs with Janus‐core prepared by these telechelic fluorocarbon‐terminated triblock copolymers.
Adaptive Polymeric Coatings with Self‐Reporting and Self‐Healing Dual Functions from Porous Core–Shell Nanostructures
Authors: Wang Jun‐Peng , Wang Jun‐Kuo , Zhou Qiong , Li Zhan , Han Yongsheng , Song Yan , Yang Shuo , Song Xiaoke , Qi Tao , Möhwald Helmuth , Shchukin Dmitry , Li Guo Liang 
Published: February 2018

AbstractIn biological system, early detection and treatment at the same moment is highly required. For synthetic materials, it is demanding to develop materials that possess self‐reporting of early damage and self‐healing simultaneously. This dual function is achieved in this work by introducing an intelligent pH‐responsive coatings based on poly(divinylbenzene)‐graft‐poly(divinylbenzene‐co‐methacrylic acid) (PDVB‐graft‐P(DVB‐co‐AA)) core–shell microspheres as smart components of the polymer coatings for corrosion protection. The key component, synthesized PDVB‐graft‐P(DVB‐co‐AA) core–shell microspheres are porous and pH responsive. The porosity allows for encapsulation of the corrosion inhibitor of benzotriazole and the fluorescent probe, coumarin. Both loading capacities can be up to about 15 wt%. The polymeric coatings doped with the synthesized microspheres can adapt immediately to the varied variation in pH value from the electrochemical corrosion reaction and release active molecules on demand onto the damaged cracks of the coatings on metal surfaces. It leads simultaneously to the dual functions of self‐healing and self‐reporting. The corrosion area can be self‐reported in 6 h, while the substrate can be protected at least for 1 month in 3.5 wt% NaCl solution. These pH‐responsive materials with self‐reporting and self‐healing dual functions are highly expected to have a bright future due to their smart, long‐lasting, recyclable, and multifunctional properties.
Association between glutathione peroxidase 1 codon 198 variant and the occurrence of breast cancer in Rwanda
Authors: Habyarimana Thierry , Bakri Youssef , Mugenzi Pacifique , Mazarati Jean Baptiste , Attaleb Mohammed , El Mzibri Mohammed 
Published: February 2018

AbstractBackgroundGlutathione peroxidase 1 gene (GPX1) is one of the antioxidant enzyme that remove the reactive oxygen species in a continuous process. Since the identification of a well‐characterized functional polymorphism named p.Pro198Leu (rs1050450 C>T) in GPX1 gene, abundant studies have evaluated the association between p.Pro198Leu polymorphism and tumor risk in diverse population. But, the available results related to breast cancer are conflicting and absent in Africa. The present case–control study was planned to assess the presence of GPX1 Pro198Leu polymorphism in Rwanda population to determine whether it is associated with the risk of developing breast cancer.MethodsGenomic DNA from peripheral blood leukocytes of 41 patients with breast cancer and 42 healthy controls were enrolled and genotyped GPX1 Pro198Leu polymorphism by PCR amplification and DNA sequencing.ResultsNo significant difference in the frequencies of Pro/Pro (49%) and Pro/Leu (51%) genotypes in cancer cases and in controls (50% each) were found. The allelic frequencies of Pro and Leu were 74% versus 26% and 75% versus 25% in breast cancer cases and controls respectively. No association was observed in allele frequencies of Pro and Leu, and familial history. Only an overall association of GPX1 Pro198Leu with grade of cancer (Pro/Leu vs. Pro/Pro: p = .0200) was detected.ConclusionThe result of this study suggested that GPX1 Pro198Leu polymorphism could not be a risk factor for breast cancer in Rwanda. However, large‐scale studies on the effect of this polymorphism on the factors disturbing the redox homeostasis are needed for conclusive understanding.
Current Level of Fish Consumption is Associated with Mortality in Chinese but not US Adults: New Findings From Two Nationwide Cohort Studies With 14 and 9.8 Years of Follow‐Up
Authors: Zhuang Pan , Wang Wenqiao , Wang Jun , Zhang Yu , Jiao Jingjing 
Published: February 2018

ScopeWhether dietary fish consumption is linked to mortality remains unclear. We aim to investigate the association of fish consumption with mortality in Chinese and US nationwide populations.Methods and resultsWe utilize data from China Health and Nutrition Survey (CHNS, n = 14 117) and National Health and Nutrition Examination Survey (NHANES, n = 33 221) including NHANES III conducted in 1988–1994 and continuous NHANES 1999–2010. Cox proportional hazards regression is used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). During a median follow‐up of 14 and 9.8 years for CHNS and NHANES, 1007 and 5209 deaths are documented, respectively. Among Chinese adults, increased fish intake is significantly associated with decreased total mortality. The multivariable‐adjusted HRs (95% CIs) across increasing categories of fish intake are 0.45 (0.36–0.56), 0.72 (0.60–0.86), and 0.70 (0.59–0.85) (p trend < 0.0001). However, fish intake is not associated with total mortality among US adults (p trend = 0.21). We only detected a borderline inverse association between fish intake and stroke mortality (p trend = 0.05), whereas a positive association with diabetes mortality in the third category of fish intake in NHANES.ConclusionIn these two nationwide cohort studies, fish consumption is associated with a reduced risk of total mortality for Chinese but not US populations.
Relativistic heavy atom effect on 13C NMR chemical shifts initiated by adjacent multiple chalcogens
Authors: Rusakov Yu.Yu. , Rusakova I.L. 
Published: February 2018

AbstractIn this paper, we have investigated the cumulative peculiarity of the “heavy atom on light atom” effect on the 13C NMR chemical shifts, initiated by the adjacent chalcogens. For this purpose, the most accurate hybrid computational scheme for the calculation of chemical shifts of carbon nuclei, directly bonded with several heavy chalcogens, is introduced and attested on the representative series of molecules. The best hybrid scheme combines the nonrelativistic coupled cluster‐based approach with the different types of corrections, including vibrational, solvent, and relativistic. The dependences of the total relativistic corrections to carbon shielding constants in 2 series of model compounds, namely, X═13C═Y (X, Y = O, S, Se, Te) and C(XH)m(YH)n(ZH)p(QH)sH1‐mH1‐nH1‐pH1‐s (X, Y, Z, Q = S, Se, Te and m, n, p, s = 0, 1), on the total atomic number of the adjacent chalcogens have been obtained.
Urotherapy in children with dysfunctional voiding and the responsiveness of two condition‐specific questionnaires
Authors: Noordhoff Toscane C. , 't Hoen Lisette A. , van den Hoek Joop , Verhallen‐Dantuma Jacintha T. C. M. , van Ledden‐Klok Marjan J. , Blok Bertil F. M. , Scheepe Jeroen R. 
Published: February 2018

AimsWe sought to establish the responsiveness of the Dutch Vancouver Symptom Score for Dysfunctional Elimination Syndrome (VSSDES) and Pediatric urinary incontinence Quality of life (PinQ) questionnaires. Secondary, we evaluated the outcome of urotherapy extended for children with dysfunctional voiding (DV).MethodsThis cross‐sectional multicenter study was done in one tertiary and two community hospitals. Children with DV were included, also when refractory to previous urotherapeutic treatment. The questionnaires were completed before and after urotherapy. The primary outcome measure was the responsiveness of the Dutch VSDESS and PinQ. Secondary outcome was the initial success (defined by the International Children's Continence Society) of extended urotherapy.ResultsBetween June 2014 and May 2016, 64 children (median age 7 years, IQR 6‐10) received urotherapy (median 18 weeks, IQR 11‐28). In contrast to the VSSDES, the PinQ showed good responsiveness. For children and parents, respectively, the area under the ROC‐curve was 0.79 (P = 0.01) and 0.72 (P = 0.03) for the PinQ and 0.50 (P = 0.98) and 0.55 (P = 0.62) for the VSSDES. Fifty children received extended urotherapy, 27 had complete, and 14 had partial response. Sixteen children had been refractory to previous treatment; four showed complete, and six showed partial response.ConclusionThe PinQ is able to detect clinically important changes in continence‐specific quality of life after treatment. We support the use of the VSSDES questionnaire in addition to the current diagnostics for the diagnosis of DV. Extended urotherapy showed to be a successful treatment for children with DV, also for those who had received previous unsuccessful treatment.
Local Fourier analysis of block‐structured multigrid relaxation schemes for the Stokes equations
Authors: He Yunhui , MacLachlan Scott P. 
Published: February 2018

SummaryMultigrid methods that use block‐structured relaxation schemes have been successfully applied to several saddle‐point problems, including those that arise from the discretization of the Stokes equations. In this paper, we present a local Fourier analysis of block‐structured relaxation schemes for the staggered finite‐difference discretization of the Stokes equations to analyze their convergence behavior. Three block‐structured relaxation schemes are considered: distributive relaxation, Braess–Sarazin relaxation, and Uzawa relaxation. In each case, we consider variants based on weighted‐Jacobi relaxation, as is most suitable for parallel implementation on modern architectures. From this analysis, optimal parameters are proposed, and we compare the efficiency of the presented algorithms with these parameters. Finally, some numerical experiments are presented to validate the two‐grid and multigrid convergence factors.
Computing the diffusion state distance on graphs via algebraic multigrid and random projections
Authors: Lin Junyuan , Cowen Lenore J. , Hescott Benjamin , Hu Xiaozhe 
Published: February 2018

SummaryIn this paper, we consider efficient and robust algorithms for computing the diffusion state distance (DSD) metric on graphs developed recently. In order to efficiently compute DSD, we reformulate the problem into graph Laplacians and use unsmoothed aggregation algebraic multigrid to solve the resulting linear system of equations. To further reduce the computational cost, we approximate DSD by using random projections based on the Johnson–Lindenstrauss lemma. Numerical results for real‐world protein–protein interaction networks are presented to demonstrate the efficiency and robustness of the proposed new approaches.
Proteomics Analysis of the Adhesion Activity of Lactobacillus acidophilus ATCC 4356 Upon Growth in an Intestine‐Like pH Environment
Authors: Wu Zhen , Wang Gang , Wang Wenwen , Pan Daodong , Peng Liuyang , Lian Liwei 
Published: February 2018

AbstractMany health effects of Lactobacillus acidophilus are desirable among these the adhesion ability is vital to enhance the possibility of colonization and stabilization associated with the gut mucosal barrier. In this study, the growth characteristics and the adhesion activity of L. acidophilus in the intestine‐like pH environment (pH 7.5) are identified. The number of bacteria adhering to the HT‐29 cells is found with a gradual increase trend (pH 5.5–7.5). This also leads to the morphological changes of L. acidophilus after exposure to different pH environments. Furthermore, with the help of the isobaric tags for relative and absolute quantification (iTRAQ) proteomic analysis, 207 proteins are detected differentially expressed at pH of 7.5. The use of GO analysis and KEGG analysis indicates three essential pathways related to the cell envelope peptide‐glycan biosynthesis, carbohydrate metabolism, and amino acid metabolism are obviously changed. Adhesion related surface protein fmtB and PrtP are upregulated in pH 7.5 group. While the moonlight proteins like pyruvate kinase, which binds specifically to the mucin layer and inhibits the adhesive activity of L. acidophilus, is found downregulated. These results could be useful to understand the adhesion mechanism of L. acidophilus adapting for the gut mucosal barrier in the intestinal environment.
Molecular weight dependent structure and charge transport in MAPLE‐deposited poly(3‐hexylthiophene) thin films
Authors: Dong Ban Xuan , Smith Mitchell , Strzalka Joseph , Li Huanghe , McNeil Anne J. , Stein Gila E. , Green Peter F. 
Published: February 2018

ABSTRACTIn this work, poly(3‐hexylthiophene) (P3HT) films prepared using the matrix‐assisted pulsed laser evaporation (MAPLE) technique are shown to possess morphological structures that are dependent on molecular weight (MW). Specifically, the structures of low MW samples of MAPLE‐deposited film are composed of crystallites/aggregates embedded within highly disordered environments, whereas those of high MW samples are composed of aggregated domains connected by long polymer chains. Additionally, the crystallite size along the side‐chain (100) direction decreases, whereas the conjugation length increases with increasing molecular weight. This is qualitatively similar to the structure of spin‐cast films, though the MAPLE‐deposited films are more disordered. In‐plane carrier mobilities in the MAPLE‐deposited samples increase with MW, consistent with the notion that longer chains bridge adjacent aggregated domains thereby facilitating more effective charge transport. The carrier mobilities in the MAPLE‐deposited simples are consistently lower than those in the solvent‐cast samples for all molecular weights, consistent with the shorter conjugation length in samples prepared by this deposition technique. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 652–662
A rapid fluorogenic GPCR–β‐arrestin interaction assay
Authors: Zhang Qiang , Zheng Yao‐Wu , Coughlin Shaun R. , Shu Xiaokun 
Published: February 2018

AbstractDetection of protein–protein interactions involved in signal transduction in live cells and organisms has a variety of important applications. We report a fluorogenic assay for G protein‐coupled receptor (GPCR)–β‐arrestin interaction that is genetically encoded, generalizes to multiple GPCRs, and features high signal‐to‐noise because fluorescence is absent until its components interact upon GPCR activation. Fluorescence after protease‐activated receptor‐1 activation developed in minutes and required specific serine–threonine residues in the receptor carboxyl tail, consistent with a classical G protein‐coupled receptor kinase dependent β‐arrestin recruitment mechanism. This assay provides a useful complement to other in vivo assays of GPCR activation.
Fosfomycin as a potential therapy for the treatment of systemic infections: a population pharmacokinetic model to simulate multiple dosing regimens
Authors: Ortiz Zacarías Natalia V. , Dijkmans Anneke C. , Burggraaf Jacobus , Mouton Johan W. , Wilms Erik B. , van Nieuwkoop Cees , Touw Daan J. , Kamerling Ingrid M. C. , Stevens Jasper 
Published: February 2018

AbstractFosfomycin has emerged as a potential therapy for multidrug‐resistant bacterial infections. In most European countries, the oral formulation is only approved as a 3 g single dose for treatment of uncomplicated cystitis. However, for the treatment of complicated systemic infections, this dose regimen is unlikely to reach efficacious serum and tissue concentrations. This study aims to investigate different fosfomycin‐dosing regimens to evaluate its rationale for treatment of systemic infections. Serum concentration‐time profiles of fosfomycin were simulated using a population pharmacokinetic model based on published pharmacokinetic parameter values, their uncertainty, inter‐individual variability and covariates. The model was validated on published data and used to simulate a wide range of dosing regimens for oral and intravenous administration of fosfomycin. Finally, based on the minimum inhibitory concentration for E. coli, surrogate pharmacodynamic indices were calculated for each dosing regimen. This is the first population pharmacokinetic model to describe the oral pharmacokinetics of fosfomycin using data from different literature sources. The model and surrogate pharmacodynamic indices provide quantitative evidence that a dosing regimen of 6–12 g per day divided in 3 doses is required to obtain efficacious exposure and may serve as a first step in the treatment of systemic multi‐drug‐resistant bacterial infections.
Single‐ and double‐electron reductions of CO2 by using superalkalis: An ab initio study
Authors: Srivastava Ambrish Kumar 
Published: February 2018

AbstractCO2, a major contributor to global warming, can be balanced by converting it into fuels. The reduction of CO2 has been difficult due to its extremely high stability. Recently, single‐electron reduction of CO2 by superalkalis has been proposed using quantum chemical methods. Herein, we report a systematic study on the single‐reduction of CO2 by using typical superalkalis. Superalkalis are hypervalent species possessing lower ionization energies than alkali atoms. We have studied the interaction of CO2 with FLi2, OLi3, and NLi4 superalkalis using ab initio MP2 calculations. We notice that this interaction leads to stable superalkali‐CO2 complexes in which the structure of CO2 is bent due to electron transfer from superalkalis. This clearly reveals that the CO2 can successfully be reduced to the
anion. It has been also noticed that the size of superalkalis plays a crucial in the single‐electron reduction of CO2. For instance, the binding energy of superalkali‐CO2 complex and charge transfer to CO2 decreases monotonically with the increase in the size of superalkali. We have also proposed that CO2 can be further reduced to
in case of the anionic complex such as (FLi2CO2)‾. Thus, FLi2 superalkali is also capable of double‐electron reduction of CO2. These findings should provide new insights into CO2‐activation as well as motivate further research in this direction.
Beliefs about learning and enacted instructional practices: An investigation in postsecondary chemistry education
Authors: Gibbons Rebecca E. , Villafañe Sachel M. , Stains Marilyne , Murphy Kristen L. , Raker Jeffrey R. 
Published: February 2018

AbstractWhile research on and development of evidence‐based instructional practices (EBIPs) in STEM education has flourished, implementation of these practices classrooms has not been as prolific. Using the teacher‐centered systemic reform model as a framework, we explore the connection between chemistry instructors’ beliefs about teaching and learning and self‐efficacy beliefs, and their enacted classroom practices. Postsecondary chemistry faculty present a unique population for the study because of their role in teaching prerequisite courses, such as general and organic chemistry, which are key to many science major fields. A measure of teacher beliefs and self‐efficacy was administered to a national survey of postsecondary chemistry faculty members. Instructional practices used in a chemistry course were also collected via self‐report. While instructional practices were not directly observed, a cluster analysis of our data mirrors patterns of instructional practices found in observation‐based studies of chemistry faculty. Significant differences are found on teacher thinking and self‐efficacy measures based on enacted instructional practices. Results support the hypothesized connection between beliefs and instructional practice on a larger scale than in previous studies of this relationship, bolstering the evidence for the importance of this relationship over previously criticized results. These results present a call for reform efforts on fostering change from its core, that is, the beliefs of those who ultimately adopt EBIPs. Dissemination and design should incorporate training and materials that highlight the process by which faculty members interpret reformed practices within their belief system, and explore belief change in the complex context of education reform.
Advances in catalytic transformations of carbohydrates and lignin in ionic liquids and mechanistic studies
Authors: Yang Yiwen , Zhang Cheng , Zhang Z. Conrad 
Published: February 2018

In biomass refinery, ionic liquids (ILs) enable more efficient conversion and higher product selectivity at milder conditions compared with conventional molecular solvents. Carbohydrates and lignin are the dominating components in biomass. The aim of this article is to update the recent progresses of ionic liquids‐based catalytic systems for lignocellulosic biomass conversions based on the published works mostly in the last 5 years. Mechanistic understanding of the catalytic processes in converting biomass to renewable chemicals and fuels is critically important for the design of superior catalysts. Apart from theoretical approaches, two recently developed characterization techniques, in situ far infrared spectroscopy and two‐dimensional nuclear magnetic resonance have been applied in the molecular level understanding of both catalysts and catalyzed reactions during biomass conversions in ILs. The major challenges and opportunities involved in the large‐scale production of biomass platform chemicals are also discussed.This article is categorized under:Bioenergy > Science and Materials