bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of in vivo MRS measures of metabolite concentrations in the human brain
Authors: Dhamala Elvisha , Abdelkefi Ines , Nguyen Mavesa , Hennessy T. Jay , Nadeau Hélène , Near Jamie
Published: January 2019

Purpose

In vivo magnetic resonance spectroscopy (MRS) is the only technique capable of non‐invasively assessing metabolite concentrations in the brain. The lack of alternative methods makes validation of MRS measures challenging. The aim of this study is to assess the validity of MRS measures of human brain metabolite concentrations by comparing multiple MRS measures acquired using different MRS acquisition sequences.

Methods

Single‐voxel SPECIAL and MEGA‐PRESS MR spectra were acquired from both the dorsolateral prefrontal cortex and primary motor cortices in 15 healthy subjects. The SPECIAL spectrum, as well as both the edit‐off and difference spectra of MEGA‐PRESS were each analyzed in LCModel to obtain estimates of the absolute concentrations of total choline (TCh; glycerophosphocholine + phosphocholine), total creatine (TCr; creatine + phosphocreatine), N‐acetylaspartate (NAA), N‐acetylaspartylglutamate (NAAG), NAA + NAAG, glutamate (Glu), glutamine (Gln), Glu + Gln, scyllo‐inositol (Scyllo), myo‐inositol (Ins), glutathione (GSH), γ‐aminobutyric acid (GABA), lactate (Lac) and aspartate (Asp). Then, having obtained up to three independent measures of each metabolite per brain region per subject, correlations between the different measures were assessed.

Results

The degree of correlation between measures varied greatly across both the metabolites and sequences tested. As expected, metabolites with the most prominent spectral peaks (TCh, TCr, NAA + NAAG, Ins and Glu) had the most well‐correlated measures between methods, while metabolites with less prominent spectral peaks (Lac, Gln, GABA, Asp, and NAAG) tended to have poorly‐correlated measures between methods. Some metabolites with relatively less prominent spectral peaks (GSH, Scyllo) had fairly well‐correlated measures between some methods. Combining metabolites improved the agreement between methods for measures of NAA + NAAG, but not for Glu + Gln.

Conclusions

Given that the ground truth for in vivo MRS measures is never known, the method proposed here provides a promising means to assess the validity of in vivo MRS measures, which has not yet been explored widely.
Hybrid enriched bidiagonalization for discrete ill‐posed problems
Authors: Hansen Per Christian , Dong Yiqiu , Abe Kuniyoshi
Published: January 2019

The regularizing properties of the Golub–Kahan bidiagonalization algorithm are powerful when the associated Krylov subspace captures the dominating components of the solution. In some applications the regularized solution can be further improved by enrichment, that is, by augmenting the Krylov subspace with a low‐dimensional subspace that represents specific prior information. Inspired by earlier work on GMRES, we demonstrate how to carry these ideas over to the bidiagonalization algorithm, and we describe how to incorporate Tikhonov regularization. This leads to a hybrid iterative method where the choice of regularization parameter in each iteration also provides a stopping rule.
Direct solution method for the equilibrium problem for elastic stents
Authors: Grubišić Luka , Tambača Josip
Published: January 2019

We are interested in numerical methods for approximating vector‐valued functions on a metric graph. As a model problem, we formulate and analyze a numerical method for the solution of the stationary problem for the one‐dimensional elastic stent model. The approximation is built using the mixed finite element method. The discretization matrix is a symmetric saddle‐point matrix, and we discuss sparse direct methods for the fast and robust solution of the associated equilibrium system. The convergence of the numerical method is proven and the error estimate is obtained. Numerical examples confirm the theoretical estimates.
Keeping College Options Open: A Field Experiment to Help all High School Seniors Through the College Application Process
Authors: Oreopoulos Philip , Ford Reuben
Published: January 2019

Recent research suggests that the college application process itself prevents access. This paper reports results from a school‐based experiment in which application assistance is incorporated into the high school curriculum for all graduating seniors at low‐transition schools. Over three workshops, students were guided to pick programs of interest that they were eligible for, apply for real, and complete the financial aid application. The goal was to create a real college option for exiting students to make the transition easier and more salient. Among all graduating seniors, the program increased application rates by 15 percentage points, and college going rates by 5 percentage points. Among those not taking advanced‐level courses, college enrollment increased by 9 percentage points. The program generated significant effects for a wide range of heterogeneous groups, including both males and females, those from urban and rural schools, and those with above and below average grades. While more intensive than other tested approaches, in‐class application assistance may provide a more effective approach for bridging the gap towards higher education.
PROMIS pediatric measures validated in a longitudinal study design in pediatric oncology
Authors: Hinds Pamela S. , Wang Jichuan , Cheng Yao I. , Stern Emily , Waldron Mia , Gross Heather , DeWalt Darren A. , Jacobs Shana S.
Published: January 2019

Purpose

This study assessed the responsiveness to change over time and theorized associations of Patient‐Reported Outcomes Measurement Information System (PROMIS) pediatric measures in children and adolescents in treatment for cancer to determine measure readiness for use in cancer clinical trials.

Methods

We administered eight PROMIS (three symptom, two psychological, and three performance) pediatric short‐form measures and the Symptom Distress Scale (SDS) to 96 pediatric oncology patients at three time points during a course of chemotherapy. We assessed responsiveness using paired t tests and generalized estimating equation (GEE) models, calculated standardized response mean (SRM) values for PROMIS measures, and examined scores over three data points (T1–T3). Guided by the theory of unpleasant symptoms (TOUS), we examined associations among the PROMIS measures, the SDS, and other variables using GEE.

Results

The paired t tests showed statistically significant changes in two psychological measures and one performance measure from T1 to T2; three symptom, two psychological and two performance measures from T2 to T3; and three symptom and two psychological measures from T1 to T3. Findings from GEE models indicate PROMIS pediatric measures had statistically significant short‐term and long‐term changes, controlling for demographic and clinical variables. One performance measure did not achieve significant change at any time point. We found positive support for theorized relationships in the TOUS.

Conclusions

Most of the PROMIS pediatric measures demonstrated changes over time and had significant relationships as theorized, thus supporting concurrent and construct validity of these measures when administered to pediatric oncology patients during a course of chemotherapy. This evidence supports the measures’ readiness for use in clinical trials.
Scoping Review of Interventions Associated with Cost Avoidance Able to Be Performed in the Intensive Care Unit and Emergency Department
Authors: Hammond Drayton A. , Gurnani Payal K. , Flannery Alexander H. , Smetana Keaton S. , Westrick Jennifer C. , Lat Ishaq , Rech Megan A.
Published: January 2019

A framework for evaluating pharmacists’ impact on cost avoidance in the intensive care unit (ICU) and emergency department (ED) has not been established. This scoping review was registered (CRD42018091217) and conducted to identify, aggregate, and qualitatively describe the highest quality evidence for cost avoidance generated by clinical pharmacists on interventions performed in an ICU or ED. Searches were conducted in PubMed, Scopus, CINAHL, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews from inception until April 2018. The level of evidence (LOE) for each specific category of intervention was evaluated according to the Grading of Recommendations, Assessment, Development and Evaluation evidence‐to‐decision framework. The risks of bias for articles were evaluated using Newcastle Ottawa and Cochrane Collaboration tools. The values from all interventions were inflated to 2018 U.S. dollars using the consumer price index for medical care. Of the 464 articles initially identified, 371 were excluded and 93 were included. After reviewing references from the articles included, an additional 71 articles were also reviewed. The 38 cost intervention categories were supported by varying LOEs: IA (0 categories), IB (1 category), IIA (4 categories), IIB (0 categories), III (27 categories), and IV (6 categories), and articles mostly displayed low to moderate risks of bias. Pharmacists generate cost avoidance through a variety of interventions in critically and emergently ill patients. The quality of evidence supporting specific cost avoidance values is generally low. Quantification of and factors associated with the cost avoidance generated from pharmacists caring for these patients are of paramount importance.
Iminoimidazole‐based Co(II) and Fe(II) complexes: Syntheses, characterization, and catalytic behaviors for isoprene polymerization
Authors: Zhang Xianhui , Zhu Guangqian , Mahmood Qaiser , Zhao Mengmeng , Wang Liang , Jing Chuyang , Wang Xiaowu , Wang Qinggang
Published: January 2019

A stereoselectivity switchable polymerization of isoprene has been developed, which is catalyzed by iminoimidazole‐Co(II) and ‐Fe(II) complexes. The influence of substituents ranging from electron donating to the electron withdrawing on the iminoimidazole‐Co(II) and ‐Fe(II) catalysts is investigated for isoprene polymerization. Two sets of iminoimidazole‐Co(II) and ‐Fe(II) complexes have been prepared and fully characterized. X‐ray crystallography analysis reveals that the complexes Co1 and Fe1 adopt distorted tetrahedral geometries. In the presence of AlEt2Cl as co‐catalyst, all the Co(II) complexes are active and the catalytic activity is highly dependent on the molar ratio of Al/Co. All the Co(II) complexes exhibit higher activities at low Al/Co ratio. Compared with the Co(II) complexes, the Fe(II) complexes are essentially inactive under the identical condition. However, on activation with combination of AlEtCl2 and [Ph3C][B(C6F5)4], both Co(II) and Fe(II) complexes display high activities with good conversions of isoprene (up to >99%). Additionally, low molecular weight and high trans‐1,4‐unit (>96%) selectivity are characteristics of the resultant polyisoprene. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 767–775
Lung disease and vitamin D levels in cystic fibrosis infants and preschoolers
Authors: Oliveira Marina S. , Matsunaga Natasha Y. , Rodrigues Marina L. E. , Morcillo André M. , de Oliveira Ribeiro Maria A. G. , Ribeiro Antônio F. , de Fátima C. P. Servidoni Maria , Nogueira Roberto José N. , Pereira Monica Corso , Ribeiro José Dirceu , Toro Adyléia Aparecida D. C.
Published: January 2019

Introduction

Vitamin D acts on the immune system and lung response. Patients with cystic fibrosis (CF) may be deficient in this vitamin. The aims of the study were to evaluate vitamin D levels and severity of lung disease in infants and preschoolers diagnosed with CF, and to compare them to a group of children without pancreatic insufficiency (PI).

Methods

Patients with CF up to 4 years old were included, and compared to an age‐matched group of children without diagnosis of CF. CF group had medical records and High Resolution Thorax Computed Tomography (HRCCT) evaluated in order to verify the severity of lung disease. Information on demographic data, sun exposure habits, supplemental vitamin D therapy, and on the season at the time of vitamin D sampling were collected for both groups.

Results

This study included 45 patients in the CF group and 102 in the non‐CF group, with no differences in age (P = 0.327) between them. There was no association between vitamin D levels and markers of lung disease in the CF group. The non‐CF group had lower daily sun exposure (P = 0.034), and lower supplementation than the CF group (P < 0.001). Supplementation and seasonality were the determinant variables for vitamin D levels, which were lower for non‐supplemented children and for assessments during fall/winter.

Conclusion

There was no association between lung disease severity and vitamin D levels in CF group. Supplementation and seasonality were associated to higher vitamin levels.
Phase 1 study of PSMA ADC, an antibody‐drug conjugate targeting prostate‐specific membrane antigen, in chemotherapy‐refractory prostate cancer
Authors: Petrylak Daniel P. , Kantoff Philip , Vogelzang Nicholas J. , Mega Anthony , Fleming Mark T. , Stephenson Joe J. , Frank Richard , Shore Neal D. , Dreicer Robert , McClay Edward F. , Berry William R. , Agarwal Manish , DiPippo Vincent A. , Rotshteyn Yakov , Stambler Nancy , Olson William C. , Morris Stephen A. , Israel Robert J.
Published: January 2019

Background

Prostate‐specific membrane antigen (PSMA) is a well‐characterized target that is overexpressed selectively on prostate cancer cells. PSMA antibody‐drug conjugate (ADC) is a fully human IgG1 monoclonal antibody conjugated to the microtubule disrupting agent monomethyl auristatin E (MMAE), which is designed to specifically bind PSMA‐positive cells, internalize, and then release its cytotoxic payload into the cells. PSMA ADC has demonstrated potent and selective antitumor activity in preclinical models of advanced prostate cancer. A Phase 1 study was conducted to assess the safety, pharmacokinetics, and preliminary antitumor effects of PSMA ADC in subjects with treatment‐refractory prostate cancer.

Methods

In this first‐in‐man dose‐escalation study, PSMA ADC was administered by intravenous infusion every three weeks to subjects with progressive metastatic castration‐resistant prostate cancer (mCRPC) who were previously treated with docetaxel chemotherapy. The primary endpoint was to establish a maximum tolerated dose (MTD). The study also examined the pharmacokinetics of the study drug, total antibody, and free MMAE. Antitumor effects were assessed by measuring changes in serum prostate‐specific antigen (PSA), circulating tumor cells (CTCs), and radiologic imaging.

Results

Fifty‐two subjects were administered doses ranging from 0.4 to 2.8 mg/kg. Subjects had a median of two prior chemotherapy regimens and prior treatment with abiraterone and/or enzalutamide. Neutropenia and peripheral neuropathy were identified as important first‐cycle and late dose‐limiting toxicities, respectively. The dose of 2.5 mg/kg was determined to be the MTD. Pharmacokinetics were approximately dose‐proportional with minimal drug accumulation. Reductions in PSA and CTCs in subjects treated with doses of ≥1.8 mg/kg were durable and often concurrent.

Conclusions

In an extensively pretreated mCRPC population, PSMA ADC demonstrated acceptable toxicity. Antitumor activity was observed over dose ranges up to and including 2.5 mg/kg. The observed anti‐tumor activity supported further evaluation of this novel agent for the treatment of advanced metastatic prostate cancer.
Trap–treat–release: horizontal transfer of fipronil in field colonies of black carpenter ants, Camponotus pennsylvanicus
Authors: Buczkowski Grzegorz
Published: January 2019

BACKGROUND

Horizontal insecticide transfer is thought to play an important role in controlling a wide range of urban pests including ants, bed bugs, cockroaches, and termites. Despite decades of research and numerous laboratory studies, horizontal transfer has never been demonstrated in the field. As a result, the importance of horizontal transfer (and the resulting secondary kill) for practical pest management remains unknown. The goal of this study was to provide the first experimental examination of horizontal transfer under field conditions. The specific objective was to investigate horizontal transfer of fipronil in field colonies of black carpenter ants, Camponotus pennsylvanicus.

RESULTS

Laboratory experiments demonstrated that fipronil is effectively transferred from treated donors to untreated recipients and causes significant secondary mortality. Fipronil was effectively vectored to untreated ants from donors exposed via residual and direct spray applications, and 100% mortality was achieved with both exposure routes. Furthermore, horizontal transfer continued beyond secondary mortality and resulted in significant tertiary mortality, which has not been previously demonstrated in ants. Field experiments utilized a novel, three‐step control method consisting of trap–treat–release and demonstrated that fipronil is effectively transferred when foraging workers are trapped, treated, and subsequently released back into their colonies.

CONCLUSION

The current study is the first field demonstration of the importance of horizontal transfer for the control of pest ants. The trap–treat–release method may be an effective alternative to broadcast spray applications and could help alleviate problems such as insecticide run‐off, environmental contamination, and non‐target effects. This method has the potential to provide effective management of invasive and pest ants and should be further tested across a wider range of ant species, habitats, and active ingredients. © 2019 Society of Chemical Industry
Guaranteed in‐control performance of the EWMA chart for monitoring the mean
Authors: Diko Mandla D. , Chakraborti Subha , Does Ronald J.M.M.
Published: January 2019

Research on the performance evaluation and the design of the Phase II EWMA control chart for monitoring the mean, when parameters are estimated, have mainly focused on the marginal in‐control average run‐length (ARLIN). Recent research has highlighted the high variability in the in‐control performance of these charts. This has led to the recommendation of studying of the conditional in‐control average run‐length (CARLIN) distribution. We study the performance and the design of the Phase II EWMA chart for the mean, using the CARLIN distribution and the exceedance probability criterion (EPC). The CARLIN distribution is approximated by the Markov Chain method and Monte Carlo simulations. Our results show that in‐order to design charts that guarantee a specified EPC, more Phase I data are needed than previously recommended in the literature. A method for adjusting the Phase II EWMA control chart limits, to achieve a specified EPC, for the available amount of data at hand, is presented. This method does not involve bootstrapping and produces results that are about the same as some existing results. Tables and graphs of the adjusted constants are provided. An in‐control and out‐of‐control performance evaluation of the adjusted limits EWMA chart is presented. Results show that, for moderate to large shifts, the performance of the adjusted limits EWMA chart is quite satisfactory. For small shifts, an in‐control and out‐of‐control performance tradeoff can be made to improve performance.
Sliding mode output‐feedback causal output tracking for a class of discrete‐time nonlinear systems
Authors: Ruiz‐Duarte Jorge E. , Loukianov Alexander G.
Published: January 2019

The output tracking (OT) of arbitrary references in discrete‐time (DT) nonlinear systems is addressed by designing an output‐feedback control. A set of difference‐algebraic equations is proposed as an exact solution of the problem. Using a novel technique of approximating DT functions, the system disturbance and steady states, characterized by tracking error identically zero, for both the system state and the control input, are represented as signals generated by a disturbed dynamic system. Using the mentioned dynamics, the control system is extended. Then, a state observer is proposed to estimate the resulting extended system state. Finally, a DT sliding mode controller is designed to achieve the approximate OT. Simulations show the effectiveness of the proposed control scheme.
The three Rs of river ecosystem resilience: Resources, recruitment, and refugia
Authors: Van Looy Kris , Tonkin Jonathan D. , Floury Mathieu , Leigh Catherine , Soininen Janne , Larsen Stefano , Heino Jani , LeRoy Poff N. , Delong Michael , Jähnig Sonja C. , Datry Thibault , Bonada Núria , Rosebery Juliette , Jamoneau Aurélien , Ormerod Steve J. , Collier Kevin J. , Wolter Christian
Published: January 2019

Resilience in river ecosystems requires that organisms must persist in the face of highly dynamic hydrological and geomorphological variations. Disturbance events such as floods and droughts are postulated to shape life history traits that support resilience, but river management and conservation would benefit from greater understanding of the emergent effects in communities of river organisms.

We unify current knowledge of taxonomic‐, phylogenetic‐, and trait‐based aspects of river communities that might aid the identification and quantification of resilience mechanisms. Temporal variations in river productivity, physical connectivity, and environmental heterogeneity resulting from floods and droughts are highlighted as key characteristics that promote resilience in these dynamic ecosystems.

Three community‐wide mechanisms that underlie resilience are (a) partitioning (competition/facilitation) of dynamically varying resources, (b) dispersal, recolonization, and recruitment promoted by connectivity, and (c) functional redundancy in communities promoted by resource heterogeneity and refugia. Along with taxonomic and phylogenetic identity, biological traits related to feeding specialization, dispersal ability, and habitat specialization mediate organism responses to disturbance. Measures of these factors might also enable assessment of the relative contributions of different mechanisms to community resilience.

Interactions between abiotic drivers and biotic aspects of resource use, dispersal, and persistence have clear implications for river conservation and management. To support these management needs, we propose a set of taxonomic, phylogenetic, and life‐history trait metrics that might be used to measure resilience mechanisms. By identifying such indicators, our proposed framework can enable targeted management strategies to adapt river ecosystems to global change.
A review on the contribution of crop diversification to Sustainable Development Goal 1 “No poverty” in different world regions
Authors: Feliciano Diana
Published: January 2019

Crop diversification is one of the most cost‐effective way of reducing uncertainties in farmer's income, especially among poor smallholder farmers. However, poverty is a complex concept, which includes more dimensions than only income. This review investigates the contribution of crop diversification to Sustainable Development Goal 1(SDG1) “No poverty” by also considering other dimensions of poverty, namely gender equality, food security and nutrition, and vulnerability to climate change. It demonstrates that the contribution of crop diversification to food security and nutrition, gender equality, and reduction of poor farmers' vulnerability to climate change has not been properly researched. Several factors across the studies analysed were found to influence the implementation of crop diversification, but these were hardly connected to poverty reduction. New research and policy impact evaluation methods that follow a sustainability approach perspective to poverty need to be undertaken in order to assess the contribution of crop diversification to SDG1.
Green IT and sustainable technology development: Bibliometric overview
Authors: García‐Berná José A. , Fernández‐Alemán José L. , Carrillo de Gea Juan M. , Nicolás Joaquín , Moros Begoña , Toval Ambrosio , Mancebo Javier , García Félix , Calero Coral
Published: January 2019

Green information technologies (GITs) constitute a field of research, whose objective is to reduce the environmental pollution caused by masses of people using and producing technology. This paper describes the search for literature related to GIT and technology sustainability in Scopus database. No restriction was imposed on the time period when carrying out the search. The data gathered revealed that the journal with the highest number of publications is Computer, and the most prolific author is Tomoya Enokido, with 45 publications. A total of 53.12% of the documents found in Scopus were Conference Paper. Although no statistically significant differences were detected, countries in the group with less CO2 kton emissions per inhabitant and less income per capita have a higher percentage of publications. The reduction of power consumption in the cloud data centers is a hot topic for future work, because the word cloud appeared in 9 out of the 10 most frequently cited papers.
A sequential density‐based empirical likelihood ratio test for treatment effects
Authors: Zou Li , Vexler Albert , Yu Jihnhee , Wan Hongzhi
Published: January 2019

In health‐related experiments, treatment effects can be identified using paired data that consist of pre‐ and posttreatment measurements. In this framework, sequential testing strategies are widely accepted statistical tools in practice. Since performances of parametric sequential testing procedures vitally depend on the validity of the parametric assumptions regarding underlying data distributions, we focus on distribution‐free mechanisms for sequentially evaluating treatment effects. In fixed sample size designs, the density‐based empirical likelihood (DBEL) methods provide powerful nonparametric approximations to optimal Neyman‐Pearson–type statistics. In this article, we extend the DBEL methodology to develop a novel sequential DBEL testing procedure for detecting treatment effects based on paired data. The asymptotic consistency of the proposed test is shown. An extensive Monte Carlo study confirms that the proposed test outperforms the conventional sequential Wilcoxon signed‐rank test across a variety of alternatives. The excellent applicability of the proposed method is exemplified using the ventilator‐associated pneumonia study that evaluates the effect of Chlorhexidine Gluconate treatment in reducing oral colonization by pathogens in ventilated patients.
Effect of Unsymmetrically Branched Alkyl Chains on the Electrochemical Band Gap and Thermal Stability of the PCDTBT
Authors: Tan Shu Er , Anuar Farah Hannan , Sarkar  , Rahman  , Sarjadi Mohd Sani
Published: January 2019

This work introduces a modified poly[N‐9’‐heptadecanyl‐2,7‐carbazole‐alt‐5,5‐(4’,7’‐di‐2‐thienyl‐2’,1’,3’‐benzothiadiazole)] (PCDTBT) with the unsymmetrically branched N‐alkyl chain, which name as poly[N‐9’‐(2‐hexyldecyl)‐2,7‐carbazole‐alt‐5,5‐(4’,7’‐di‐2‐thienyl‐2’,1’,3’‐benzothiadiazole)] (P1). The synthesis of P1 involves dimerization, cyclization, tosylation, N‐alkylation, bromination, Stille's and Suzuki's coupling reactions. Suitable analysis techniques have used to study the chemical, physical, electrochemical, optical, and thermal properties of P1. The analysis results show that P1 possesses higher HOMO and LUMO energy levels than the previously reported PCDTBT, which have been narrowing the electrochemical band gap down to 1.58 eV. However, the P1 experiences 5% thermal degradation at 280 °C, which is relatively less favourable than the PCDTBT. Hence, the replacement of the symmetrically branched alkyl chains of PCDTBT with unsymmetrically branched alkyl chains results in both improvement and drawback on the characteristics of the polymer.
Polyethyleneimine Nanofibers Functionalized with Tetradentate Schiff Base Complexes of Dioxomolybdenum(VI) as Efficient Catalysts for Epoxidation of Alkenes
Authors: Foumani Mahdi Mojallali , Khorshidi Alireza , Shojaei Abdollah Fallah
Published: January 2019

Three tetradentate Schiff base ligands (H2L1‐3) were prepared from the reaction of 5‐sustituted‐2‐hydroxybenzaldehydes and 3,4‐diaminobenzoic acid. The obtained ligands were reacted with molybdenyl acetylacetonate in ethanol to prepare the corresponding dioxomolybdenum(VI) complexes (MoO2L1‐3) in good yields (80‐82%). Immobilization of the abovementioned complexes on polyethyleneimine (PEI) was achieved via condensation of carboxylic functional groups of the complex with amine functional groups of the polymer in presence of dicyclohexylcarbodiimide (DCC) and 4‐dimethylaminopyridine (DMAP). The obtained hybrid materials were then converted to electrospun nanofibers and used as recyclable catalysts for the epoxidation of alkenes.
Exploration of Antioxidant Activities of Potentially Bioactive Compounds in Trianthema portulacastrum Herb: Chemical Identification and Quantification by GC‐MS and HPLC
Authors: Jabbar Abdul , Sirajuddin Muhammad , Iqbal Shahid , Tariq Muhammad I. , Ahmad Muhammad
Published: January 2019

Trianhtema portulacastrum (T. portulacastrum) herb is used for therapy of different diseases. The possibility of obtaining bioactive compounds from Pakistani T. portulacastrum herb using soxhlet extraction technique and identification with GC‐MS is shown for the first time here. Maximum yield of 20.33% of biologically active compounds extracts was obtained with 70% EtOH from T. Portulacastrum herb. Different esterifying agents ethanol, n‐butanol and mixture of reagent (BSTFA:TMCS in 50:50) were used for the derivatization of the extract. In GC‐MS analysis of 70% ethanolic extract of T. portulacastrum, 11 compounds were identified in dried powdered extracts after derivatization. Similarly, in HPLC analysis 5 compounds were identified in dried powdered extracts of T. portulacastrum herb. In the present work we have explored the antioxidant potentials of biologically active compounds present in Pakistani T. portulacastrum using GC‐MS and HPLC technique for their chemical identification and quantification.
MOFs‐Assisting Synthesis 3D Ni12P5 Catalyst for Hydrodechlorination of Trichloroethylene
Authors: Yuan Guojun , Bai Jianliang , Lu Shaoxiang , Ren Lili , Gao Bingying , Mei Jing , Ma Yusha , Chen Xu , Zhang Lu
Published: January 2019

We reported a new method for producing the 3D Ni12P5 catalyst. Four regular morphology metal chelates (Ni‐x) were synthesized by nickel nitrate reacting with different metal organic frameworks (MOFs). The 3D materials (Ni−P‐x) were synthesized by hydrothermal reaction with red phosphorus. The phase transition and the morphology change of Ni12P5 compounds were investigated via X‐ray diffraction (XRD), scanning electron microscopy (SEM), inductively coupled plasma (ICP) and energy dispersive X‐ray spectroscopy (EDS). Moreover, compared with the unmodified catalyst, the catalyst modified with MOFs shows better catalytic activity for hydrodechlorination of trichloroethylene (TCE). The activity of the catalyst improved after calcination at N2 atmosphere.
Viscosities and Conductivities of Binary Mixtures of 4‐(Diethoxyphosphoryl)butyl Triphenylphosphonium Hexafluorophosphate with Organic Solvents
Authors: Zhao Chuanli , Zhang Gongjun , Ge Jiawen , Wang Binbin , Liang Hongze , Yan Yinghua , Zhao Lingling
Published: January 2019

In this work, a phosphonate‐functionalized ionic liquid, 4‐(diethoxyphosphoryl)butyl triphenylphosphonium hexafluorophosphate (PFIL) has been synthesized and characterized by FTIR, NMR and HRMS spectra. The viscosities (η) and conductivities (κ) of three binary mixtures of PFIL with acetonitrile (ACN), N,N‐dimethylformamide (DMF), and dimethyl sulfoxide (DMSO), respectively, were investigated in the temperature range from 293.15 to 343.15 K at atmospheric pressure. Solid PFIL dissolves in all these polar solvents within the concentrations studied (mole fraction of PFIL from 0.01 to 0.14). The experimental studies indicate that the viscosities of the three binary mixtures decrease in the following order: [PFIL(1) + DMSO(2)] > [PFIL(1) + DMF(2)] > [PFIL(1) + ACN(2)], while as expected, the conductivities increase in the following order: [PFIL(1) + ACN(2)]>[PFIL(1) + DMF(2)]>[PFIL(1) + DMSO(2)]. The conductivities as a function of temperature have been well correlated by Vogel‐Fulcher‐Tammann (VFT) and Arrhenius equations, while viscosities can be better fitted by using VFT equation. The dependence of conductivity on concentration for the studied systems is well represented by Casteel‐Amis equation.
A Green Synthesis of N,N‐ and N,O‐Heterocycles Using a Recyclable Catalyst in a Bio‐Based Solvent
Authors: Tran Chau B. , To Tuong A. , Vo Yen H. , Do Tuong T. L. , Nguyen Qui T. P. , Nguyen Anh T. , Nguyen Tung T. , Phan Nam T. S.
Published: January 2019

A plethora of heterocycle syntheses relies on the use of nonreusable metal complexes and/or toxic solvents. We report here a benign method for synthesis of five‐ or six‐membered N,N/N,O heterocycles via a coupling of 2‐aminobenzyl amine/alcohols or 1,2‐phenylene diamines with aldehydes. Reactions proceed in the presence of Cu2(OBA)2bpy (OBA=oxy‐4,4’‐bisbenzoate, bpy=2,2’‐bipyridine) catalyst and biodegradable diethyl carbonate solvent. The copper material is truly heterogeneous and reusable, up to 5 times, without a prominent loss of activity. The reaction conditions are compatible with many functionalities such as halogens, olefin, and alkyne groups. To the best of our knowledge, combining such a recyclable solid catalyst and a bio‐related solvent for the mild synthesis of N‐heterocycles is still unknown in the literature.
Enhanced Photocarrier Generation with Selectable Wavelengths by M‐Decorated‐CuInS2 Nanocrystals (M = Au and Pt) Synthesized in a Single Surfactant Process on MoS2 Bilayers
Authors: Tang Shin‐Yi , Medina Henry , Yen Yu‐Ting , Chen Chia‐Wei , Yang Tzu‐Yi , Wei Kung‐Hwa , Chueh Yu‐Lun
Published: January 2019

A facile approach for the synthesis of Au‐ and Pt‐decorated CuInS2 nanocrystals (CIS NCs) as sensitizer materials on the top of MoS2 bilayers is demonstrated. A single surfactant (oleylamine) is used to prepare such heterostructured noble metal decorated CIS NCs from the pristine CIS. Such a feasible way to synthesize heterostructured noble metal decorated CIS NCs from the single surfactant can stimulate the development of the functionalized heterostructured NCs in large scale for practical applications such as solar cells and photodetectors. Photodetectors based on MoS2 bilayers with the synthesized nanocrystals display enhanced photocurrent, almost 20–40 times higher responsivity and the On/Off ratio is enlarged one order of magnitude compared with the pristine MoS2 bilayers‐based photodetectors. Remarkably, by using Pt‐ or Au‐decorated CIS NCs, the photocurrent enhancement of MoS2 photodetectors can be tuned between blue (405 nm) to green (532 nm). The strategy described here acts as a perspective to significantly improve the performance of MoS2‐based photodetectors with the controllable absorption wavelengths in the visible light range, showing the feasibility of the possible color detection.
Nanostructuring Confinement for Controllable Interfacial Charge Transfer
Authors: Qiao Wei , Tao Hua Bing , Liu Bin , Chen Jiazang
Published: January 2019

Carbon nanostructures supported semiconductors are common in photocatalytic and photoelectrochemical applications, as it is expected that the nanoconductors can improve the spatial separation and transport of photogenerated charge carriers. Transfer of charge carriers through the carbon‐semiconductor interface is the key electronic process, which determines the role of charge separation channels, and is sensitively influenced by band structures of the semiconductor near the contacts. Usually, this electronic process suffers from excessive energy dissipation by thermionic emission, which will undesirably prevent the interfacial charge transfer and eventually aggravate the recombination of photogenerated charge carriers. Unfortunately, this critical issue has hardly been consciously considered. Here, ultrathin dopant‐free tunneling interlayers coated on the surface of graphene and sandwiched between the carbon sheets and the semiconductor nanostructures are adopted as a model system to demonstrate energy saving for the interfacial charge transfer. The nanostructuring confinement of band bending within the ultrathin interlayers in contact with the graphene sheets effectively narrows the width of the potential barriers, which enables tunneling of a substantial number of photogenerated electrons to the co‐catalysts without unduly consuming energy. Besides, the dopant‐free tunneling interlayers simultaneously block the transferred electrons in the sandwiched graphene sheets from leakage.
N,P Co‐Coordinated Manganese Atoms in Mesoporous Carbon for Electrochemical Oxygen Reduction
Authors: Zhu Xiaofeng , Amal Rose , Lu Xunyu
Published: January 2019

The increasing interest in fuel cell technology encourages the development of efficient and low‐cost electrocatalysts to replace the Pt based materials for catalyzing the cathodic oxygen reduction reaction (ORR). In the present work, a nitrogen and phosphorus co‐coordinated manganese atom embedded mesoporous carbon composite (MnNPC‐900) is successfully prepared via a polymerization of o‐phenylenediamine followed by calcination at 900 °C. The MnNPC‐900 composite shows a high ORR activity in alkaline media, offering an onset potential of 0.97 V, and a half‐wave potential of 0.84 V (both vs reversible hydrogen electrode) with a loading of 0.4 mg cm−2. This performance not only exceeds its phosphorus‐free counterpart (MnNC‐900), but also is comparable to the Pt/C catalyst under identical measuring conditions. The significantly enhanced ORR performance of MnNPC‐900 can be ascribed to: i) the introduction of phosphorus assists the generation of mesopores during the pyrolysis and endows the MnNPC‐900 composite with large surface area and pore volume, thus facilitating the mass transfer process and increases the number of exposed active sites. ii) The formation of N,P co‐coordinated atomic‐scale Mn sites (MnNxPy), which modifies the electronic configuration of the Mn atoms and thereby boosts the ORR catalytic activity.
TiO2 and Co Nanoparticle‐Decorated Carbon Polyhedra as Efficient Sulfur Host for High‐Performance Lithium–Sulfur Batteries
Authors: Liu Ruiqing , Liu Zhiwei , Liu Wenhui , Liu Yuejiao , Lin Xiujing , Li Yi , Li Pan , Huang Zhendong , Feng Xiaomiao , Yu Leshu , Wang Dan , Ma Yanwen , Huang Wei
Published: January 2019

Metal organic frameworks (MOFs)‐derived porous carbon is proposed as a promising candidate to develop novel, tailorable structures as polysulfides immobilizers for lithium–sulfur batteries because of their high‐efficiency electron conductive networks, open ion channels, and abundant central ions that can store a large amount of sulfur and trap the easily soluble polysulfides. However, most central ions in MOFs‐derived carbon framework are encapsulated in the carbon matrix so that their exposures as active sites to adsorb polysulfides are limited. To resolve this issue, highly dispersed TiO2 nanoparticles are anchored into the cobalt‐containing carbon polyhedras that are converted from ZIF‐67. Such a type of TiO2 and Co nanoparticles‐decorated carbon polyhedras (CCo/TiO2) provide more exposed active sites and much stronger chemical trapping for polysulfides, hence improving the sulfur utilization and enhancing reaction kinetics of sulfur‐containing cathode simultaneously. The sulfur‐containing carbon polyhedras decorated with TiO2 nanoparticles (S@CCo/TiO2) show a significantly improved cycling stability and rate capability, and deliver a discharge capacity of 32.9% higher than that of TiO2‐free S@CCo cathode at 837.5 mA g−1 after 200 cycles.
Realizing 8.6% Efficiency from Non‐Halogenated Solvent Processed Additive Free All Polymer Solar Cells with a Quinoxaline Based Polymer
Authors: Zhou Liuyang , Lau Tsz‐Ki , Peng Hongjian , Qiu Beibei , Jiang Lihui , Lu Xinhui , Zhang Guanghui , Yuan Jun , Li Yongfang , Zou Yingping
Published: January 2019

In this work, a medium bandgap quinoxaline (Qx) based polymer, named TTFQx‐T1, and a narrow bandgap n‐type polymer, named N2200, are employed to fabricate all‐polymer solar cells (all‐PSCs), which exhibited good light absorption for high short circuit current density (Jsc), well‐matched molecular energy level for good charge separation and high open circuit voltage (Voc). Chlorinated solvents are harmful to both the environment and human beings; therefore, it is important to develop environmentally friendly solvents. Considering this, the green solvent tetrahydrofuran (THF) was employed to process all‐PSCs. The blend films based on TTFQx‐T1:N2200 processed with THF and thermal annealing (TA) exhibited better phase separation and preferential face‐on orientation toward the substrate, which benefited the exciton dissociation and charge carrier mobilities for higher FF and Jsc. The optimized device based on TTFQx‐T1:N2200 delivered an efficient power conversion efficiency of 8.63%, which is the highest value for all‐PSCs from Qx based polymers.
Lagged principal trend analysis for longitudinal high‐dimensional data
Authors: Zhang Yuping
Published: January 2019

Biological systems are dynamic in nature, where time‐lagged correlations are commonly observed. Motivated by the problem of integrating longitudinal high‐dimensional datasets with time‐lagged temporal associations, we have developed a new statistical learning method named lagged principal trend analysis (LAPTA). Specifically, given longitudinal high‐dimensional datasets of two cohorts, LAPTA can extract time‐lagged associations and identify relevant features. The practical merits of LAPTA have been demonstrated through simulations and applications to host transcriptional response to influenza A infection data.
Effect of the torsional stiffness of closed‐section stiffeners on plate buckling in Eurocode 3, Part 1‐5
Authors: Martin Pierre‐Olivier , Nguyen Tien Minh , Davaine Laurence
Published: January 2019

Longitudinally stiffened plates are commonly used to increase the resistance to plate buckling. Closed cross‐section stiffeners provide high values of the torsional stiffness and thus are very efficient to avoid their premature lateral torsional buckling. With the current software tools, it is easy to assess the critical stress for the elastic global mode, taking into account the beneficial effect of these high values of torsional stiffness for stiffeners with closed cross‐sections. However, the torsional stiffness of longitudinal stiffeners is not considered in the analytical formula proposed by Annex A of EN 1993‐1‐5 for the assessment of the global buckling critical stress. A study is presented here where the effect of the torsional stiffness of longitudinal stiffeners on the plate buckling criterion of EN 1993‐1‐5 has been analysed. 216 configurations of stiffened plates were calculated through finite element GMNIA non linear analyses. Their compressive strength thus obtained were compared to their resistance to plate buckling as predicted by EN 1993‐1‐5, either by considering their torsional stiffness with EBPlate software or by completely ignoring it. The study clearly shows that EN 1993‐1‐5 leads to unsafe results when the torsional stiffness is taken into account in the calculations. Finally, it is concluded that the torsional stiffness of longitudinal stiffeners has to be ignored in the design of stiffened plates according to EN 1993‐1‐5.
Distortional buckling of X‐joints made of square hollow cross‐section beams: theoretical energy‐based model
Authors: Björk Timo , Ahola Antti , Tuominen Niko
Published: January 2019

Current design codes do not consider distortional buckling failure modes, which can occur in the chord member of a tubular X‐joint loaded axially by brace members. In this study the critical load for distortional buckling is established based on the energy method and a beam on elastic foundation (BEF) approach. In the theoretical model the capacity is created by elastic bending of the chord faces in their own planes and elastic bending of the cross‐section as a frame structure. The theoretical capacity of an X‐joint is compared with numerical results obtained from finite element analyses (FEAs). Some discrepancy was found between theoretical model and numerical analysis, with the theoretical model slightly underestimating the load‐carrying capacity. Experimental tests show that an X‐joint can be prone to distortional buckling failure mode. However, detailed scrutiny of distortional buckling failure in X‐joints is only legitimate for joints made of high‐strength steel (HSS), because other failure mechanisms are more critical when conventional steels are used. Nevertheless, designers of X‐joints with rectangular hollow section (RHS) members should be aware of this potential failure mode.
Calibration of European web‐crippling equations for cold‐formed C‐ and Z‐sections
Authors: Misiek Thomas , Belica Andrej
Published: January 2019

Current design equations given in EN 1993‐1‐3 for calculating the web‐crippling resistance of cross‐sections with one web were copied from the AISI's Specification for the design of cold‐formed steel structural members, taking into account the different safety concepts: load and resistance factor design (LRFD), with resistance factors ϕw applied to nominal values, and limit state design, with partial factors γM applied to characteristic values as defined in EN 1990. Furthermore, the web‐crippling equations of subsequent editions of the AISI specification (then designated AISI S100) were completely revised based on the web‐crippling data collected and evaluated by Beshara and Schuster [5].

This paper presents the results of a calibration of a generalized web‐crippling equation to be used for cross‐sections with one web (i.e. C‐ and Z‐sections). The coefficients of the generalized web‐crippling equation were calibrated to comply with the safety concept described in EN 1990, taking into account EN 1990, Annex D, and a partial factor γM1 = 1.1. This paper therefore provides an introduction to as well as background information on proposed changes and amendments to EN 1993‐1‐3.
Dimensional Control in Contorted Aromatic Materials
Authors: Peurifoy Samuel R. , Sisto Thomas J. , Ng Fay , Steigerwald Michael L. , Chen Rongsheng , Nuckolls Colin
Published: January 2019

This Account details key developments in dimensional control of contorted aromatics for organic electronics. Coronene, perylene, pyrene, and [4]helicene, which are fragments of graphene, can be contorted using facile synthetic chemistry into large nanoribbons and nano‐architectures. In comparing contorted or higher‐dimensional graphene architectures to planar or lower‐dimensional species, the materials properties are reliably enhanced for the contorted aromatics. Examples of enhanced properties include optical absorptivity, conductivity, device photoconversion efficiency, and solubility. These enhancements are exemplified in organic photovoltaics, photodetectors, field effect transistors, and perovskite solar cells. Described herein are key advances in dimensional control of contorted aromatics that have resulted in world record photoconversion efficiencies, photodetection capabilities matching inorganic state‐of‐the‐art devices, and ∼5 nm long ultrathin soluble graphene nanoribbons.
Subleading soft theorem for arbitrary number of external soft photons and gravitons
Authors: Bhatkar Sayali Atul , Sahoo Biswajit
Published: January 2019

Abstract

We obtain the subleading soft theorem for a generic theory of quantum gravity, for arbitrary number of soft photons and gravitons and for arbitrary number of finite energy particles with arbitrary mass and spin when all the soft particles are soft in the same rate. This result is valid at tree level for spacetime dimensions equal to four and five and to all loop orders in spacetime dimensions greater than five. We verify that in classical limit, low energy photon and graviton radiation decouple from each other.