bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal‐Free Catalytic Reduction of 4‐Nitrophenol by MOFs‐Derived N‐Doped Carbon
Authors: Wang Zhenhua , Chen Qianwang 
Published: January 2018

AbstractWith the development of Metal organic frameworks (MOFs) materials, various functional carbon materials prepared using MOFs as precursors have attracted more and more attention. In this work, the N‐doped carbon nanomaterial N‐C have been synthesized by annealing of ZIF‐8. In the reduction of p‐nitrophenol which is one of the most prevalent organic pollutants, N‐C shows good activity, great stability, reusability and minimal pollution compared with some of the previously metallic catalysts. The N‐C prepared by annealing at different temperatures owns different nitrogen contents and different catalytic activity. It was found that N‐C800 (annealed at 800 °C) shows the highest pyridine N content and the best catalytic activity, and the reaction follows the pseudo‐zero‐order kinetics.
Suppressing Electromagnetic Radiation by Trapping Ferrite Nanoparticles and Carbon Nanotubes in Hierarchical Nanoporous Structures Designed by Crystallization‐Induced Phase Separation
Authors: Sharma Maya , Singh Deepinder , Menon Aishwarya , Madras Giridhar , Bose Suryasarathi 
Published: January 2018

AbstractPolymer blends are at the forefront of research especially in the field of Electromagnetic Interference (EMI) shielding because of their versatile properties such as ease of processability, economic viability and high strength to weight ratio. Herein, we have attempted to design lightweight blend composites consisting of multiwalled carbon nanotubes (MWNTs) and nickel ferrite (NiFe2O4) nanoparticles. A unique approach was adopted here to prepare ultra‐thin (500 μm), flexible, lightweight composite membranes wherein hierarchical nanoporous structures were initially developed by crystallization induced phase separation in a classical upper critical solution temperature (UCST) pair Polyvinylidene fluoride/poly methyl methacrylate (PVDF/PMMA) and subsequently etching out the PMMA phase. In the next step, functional nanoparticles were trapped in the pores by facile vacuum filtration approach. This unique approach led to the fabrication of nanoporous composite membranes which otherwise is difficult to process using conventional techniques. The composite membranes show high magnetic permeability and high electrical conductivity; the two key requirements for effective shielding of electromagnetic (EM) radiation. A significant improvement in shielding effectiveness (SE) was achieved using these token composite membranes. For instance, porous PVDF composite membranes containing 3 wt % MWNTs (with a thickness of 500 μm) showed an SE of 8 dB which enhanced significantly to 27 dB for composite membranes wherein NiFe2O4 is trapped in the pores. More interestingly, the mechanism of shielding was driven by absorption (nearly 80%) through synergistic properties of interconnected MWNTs and NiFe2O4 nanoparticles.
Interaction of a Triaryl Methane Dye with Cucurbit[7]uril and Bovine Serum Albumin: A Perspective of Cooperative versus Competitive Bindings
Authors: Chakraborty Goutam , Ray Alok. K. , Pal Haridas 
Published: January 2018

AbstractInteractions of a triaryl methane dye, crystal violet (CV), with cucurbit[7]uril (CB7) and bovine serum albumin (BSA) hosts have been investigated using various photophysical studies. While due to its structural flexibility free CV is very weakly fluorescent its binding to CB7 and BSA hosts leads to significant fluorescence enhancements, the effect being very larger with BSA host than CB7. In both CV‐BSA and CV–CB7 systems, CV binds through 1:1 inclusion complex formation, the binding constant (Kb) being as large as ∼3.4x105 M−1 for the former as compared to a moderate Kb of ∼6.3x103 M−1 for the latter system. In CV–CB7‐BSA ternary system, where measurements were done keeping one of the host concentration constant and significantly higher and gradually increasing the concentration of the other host in the solution, the changes observed in the absorption and fluorescence characteristics of the dye as well as that observed in the binding isotherms clearly indicate a competitive binding interaction of CV with both CB7 and BSA hosts simultaneously present in the solution. To be emphasized that the competitive binding interaction observed for the CV–CB7‐BSA ternary system is similar to the commonly encountered interaction in many dye‐host‐biomacromolecule kind of ternary systems but differs strikingly from the unique cooperative interaction reported earlier for an analogous dye, brilliant green (BG), with the same CB7 and BSA hosts.
Synthesis of Pyrido[2, 3‐a]phenoxazines and Pyrido[2, 3‐a]phenothiazines via Successive SNAr Processes
Authors: Starosotnikov Alexey M. , Nikol'skiy Vladislav V. , Bastrakov Maxim A. , Kachala Vadim V. , Pavlov Alexander A. , Ugrak Bogdan I. , Shevelev Svyatoslav A. 
Published: January 2018

AbstractAn efficient method was developed for the synthesis of novel pyrido[2, 3‐a]phenoxazines and phenothiazines. The base‐promoted reaction of 8‐chloro‐5,7‐dinitroquinoline with binucleophiles (o‐aminophenols and o‐aminothiophenols) results in substitution of the chlorine atom followed by replacement of the nitro group. In case of aminothiophenols the products of in situ Smiles rearrangement were isolated.
An Efficient One‐Pot Synthesis of Chiral N‐Protected 3‐Substituted (Diketo)piperazines via Ugi‐4CR/De‐Boc/Cyclization Process
Authors: Jida Mouhamad , Ballet Steven 
Published: January 2018

AbstractA convenient and high yielding method to prepare a vast array of enantiomerically pure 3‐substituted diketopiperazines (3‐DKPs), bearing a benzyl protecting group on nitrogen 1 is reported. The methodology describes a simple one‐pot procedure, starting from readily available N‐protected L‐ or D‐amino acids employing the Ugi‐4CR in pure water, followed by a one‐step Boc‐deprotection and final lactamisation in acetic acid. All disubstituted DKPs were obtained in short times and isolated in excellent yields (84‐94%) by simple precipitation in water and subsequent filtration. The practical utility of this procedure proved efficient for the synthesis of cialis (Tadalafil) analogues.
Studies towards the Synthesis of Thermolide–6′
Authors: Satyanarayana Vavilapalli , Muralikrishna Katta , Kumar Gavireddy Chaithanya , Kumar Alleni Suman , Babu Nanubolu Jagadeesh , Yadav Jhillu Singh 
Published: January 2018

AbstractA highly stereoselective and an efficient approach for studies towards the synthesis of thermolide‐6′ has been described. The salient features of the synthesis are the utilization of desymmetrization protocol, Barton‐McCombie deoxygenation and C−C bond formation from an aldol reaction.
Studies towards the Synthesis of Lepranthin
Authors: Satyanarayana Vavilapalli , Kumar Alleni Suman , Muralikrishna Katta , Kumar Gavireddy Chaithanya , Kumar R Sudheer , Kumar Chinthakrinda Suresh , Yadav Jhillu S. 
Published: January 2018

AbstractA highly stereoselective and an efficient approach for studies towards the synthesis of lepranthin has been described. The key steps involved in this synthesis are desymmetrization protocol, Brown's asymmetric allylation, Wacker oxidation and Corey‐Bakshi‐Shibata reduction.
Transition‐Metal‐Free Borylation of Alkynes and Alkenes
Authors: Deng Chun M. , Ma Yi F. , Wen Yan M. 
Published: January 2018

AbstractThe transition metal‐free method for borylation of alkynes and alkenes with bis(pinacolato)diboron has been developed, producing the correspondent organoborons under mild reaction conditions. This reaction was an efficient, practical and environment‐friendly process which brings forth vinylboronate products with excellent regioselectivity in the borylation of alkynes with bis(pinacolato)diboron, while in the meantime the diboryl alkanes were obtained using alkenes as substrates.
Effect of Substituents on the Reactivity of Ninhydrin with Urea
Authors: Jong Jacobus A. W. , Moret Marc‐Etienne , Verhaar Marianne C. , Hennink Wim E. , Gerritsen Karin G. F. , van Nostrum Cornelus F. 
Published: January 2018

AbstractNinhydrin, i. e. the stable hydrate of the reactive species indanetrione, is a well‐known compound used for the quantification of ammonia and amino acids. However, substituent effects on the reactivity of ninhydrin with nucleophiles are not described. In this work, the kinetics of the reaction of C4‐ and C5‐ substituted ninhydrins with urea was studied and monitored by 13C‐NMR. Surprisingly, the obtained results show that electron donating groups (EDGs) as well as electron withdrawing groups (EWGs) decrease the rate of the reaction. EDGs decrease the electrophilicity of indanetrione, resulting in slower overall kinetics than unsubstituted ninhydrin. The calculated Gibbs free energy differences for the dehydration of unsubstituted and substituted ninhydrins and the subsequent reaction with urea showed that the dehydration of the compounds is more sensitive to electronic effects than the subsequent reaction with urea. Therefore, although EWGs increase the electrophilicity of indanetrione, this is more than counterbalanced by an adverse shift of the hydration equilibrium towards the unreactive hydrate (i. e. ninhydrin), resulting in slower kinetics as well.
Ultrasmall Pb:Ag2S Quantum Dots with Uniform Particle Size and Bright Tunable Fluorescence in the NIR‐II Window
Authors: He He , Lin Yi , Tian Zhi‐Quan , Zhu Dong‐Liang , Zhang Zhi‐Ling , Pang Dai‐Wen 
Published: January 2018

AbstractAg2S quantum dots (QDs) are well‐known near‐infrared fluorophores and have attracted great interest in biomedical labeling and imaging in the past years. However, their photoluminescence efficiency is hard to compete with Cd‐, Pb‐based QDs. The high Ag+ mobility in Ag2S crystal, which causes plenty of cation deficiency and crystal defects, may be responsible mainly for the low photoluminescence quantum yield (PLQY) of Ag2S QDs. Herein, a cation‐doping strategy is presented via introducing a certain dosage of transition metal Pb2+ ions into Ag2S nanocrystals to mitigate this intrinsic shortcoming. The Pb‐doped Ag2S QDs (designated as Pb:Ag2S QDs) present a renovated crystal structure and significantly enhanced optical performance. Moreover, by simply adjusting the levels of Pb doping in the doped nanocrystals, Pb:Ag2S QDs with bright emission (PLQY up to 30.2%) from 975 to 1242 nm can be prepared without altering the ultrasmall particle size (≈2.7–2.8 nm). Evidently, this cation‐doping strategy facilitates both the renovation of crystal structure of Ag2S QDs and modulation of their optical properties.
Fabrication and Deformation of 3D Multilayered Kirigami Microstructures
Authors: Humood Mohammad , Shi Yan , Han Mengdi , Lefebvre Joseph , Yan Zheng , Pharr Matt , Zhang Yihui , Huang Yonggang , Rogers John A. , Polycarpou Andreas A. 
Published: January 2018

AbstractMechanically guided 3D microassembly with controlled compressive buckling represents a promising emerging route to 3D mesostructures in a broad range of advanced materials, including single‐crystalline silicon (Si), of direct relevance to microelectronic devices. During practical applications, the assembled 3D mesostructures and microdevices usually undergo external mechanical loading such as out‐of‐plane compression, which can induce damage in or failure of the structures/devices. Here, the mechanical responses of a few mechanically assembled 3D kirigami mesostructures under flat‐punch compression are studied through combined experiment and finite element analyses. These 3D kirigami mesostructures consisting of a bilayer of Si and SU‐8 epoxy are formed through integration of patterned 2D precursors with a prestretched elastomeric substrate at predefined bonding sites to allow controlled buckling that transforms them into desired 3D configurations. In situ scanning electron microscopy measurement enables detailed studies of the mechanical behavior of these structures. Analysis of the load–displacement curves allows the measurement of the effective stiffness and elastic recovery of various 3D structures. The compression experiments indicate distinct regimes in the compressive force/displacement curves and reveals different geometry‐dependent deformation for the structures. Complementary computational modeling supports the experimental findings and further explains the geometry‐dependent deformation.
A Universal Upconversion Sensing Platform for the Sensitive Detection of Tumour‐Related ncRNA through an Exo III‐Assisted Cycling Amplification Strategy
Authors: Zhang Keying , Yang Lin , Lu Feng , Wu Xingcai , Zhu Jun‐Jie 
Published: January 2018

AbstractHere, a sensitive and universal noncoding RNA (ncRNA) upconversion sensing nanoplatform is developed. Gold nanoparticles bearing one hairpin DNA (Hp) molecule are conjugated to the linker DNA modified NaYF4:Yb, Er@NaYF4 upconversion nanoparticles by DNA hybridization, leading to quenching of the upconversion emission through fluorescence resonance energy transfer. A signal DNA (SDNA) sequence is designed to open Hp, recovering the upconversion emission. To achieve universality and high sensitivity of the nanoprobe, an exonuclease III (Exo III)‐assisted cycling amplification strategy is introduced. A multifunctional hairpin DNA (mHp) containing ncRNA recognition sequence and SDNA sequence is designed to recognize ncRNA and trigger Exo III as a biocatalyst to stepwise disintegrate itself, releasing both ncRNA and SDNA. The released ncRNA can be reused to release more SDNA, which greatly improves the sensing sensitivity. By changing the recognition portion of mHp, various ncRNA can be detected. The sensitive detection of both homeobox (HOX) transcript antisense RNA segment and miR‐21 is achieved with this novel strategy, even in human serum, indicating the universality and sensitivity of the proposed strategy. Additionally, the expression level of miR‐21 in human breast cancer cell (MCF‐7) lysate is successfully measured, suggesting its potential in clinical diagnosis.
Evaluation of a dedicated ultrasound fine needle aspiration service for thyroid nodules
Authors: Tan Chelsea , Lavender Ilona , Naismith Amanda , Nguyen Qui , Ptasznik Ronnie , Nandurkar Dee , Wong Jennifer , Kumar Beena , Fuller Peter J. , Coombs Peter R. , Mond Michael 
Published: January 2018

AbstractIntroductionWe studied whether: (1) a quality‐focused thyroid fine needle aspiration (FNA) service reduced the non‐diagnostic (ND) rate of FNA; (2) the implementation of thyroid FNA selection criteria resulted in higher proportion of Bethesda V and VI cytology and malignant histopathology; and (3) impact of radiologist's level of experience on ND rates.MethodThe imaging and pathology computer databases were retrospectively searched for all patients who had thyroid FNAs at our hospitals from July 2004 to December 2016.ResultsThree hundred thirty‐eight and 609 patients in pre‐thyroid and post‐thyroid service groups, respectively, were evaluated. The ND rate of 36.7% in pre‐thyroid service was significantly higher than post‐thyroid service at 14.6% (p < 0.0001). The rates of Bethesda V and VI cytology in the pre‐thyroid service group did not differ significantly from the post‐thyroid group (p = 0.266; p = 0.069). There was no significant difference in the histopathologic malignancy rates between the two groups (p = 0.531). There was no significant difference in the ND rates of radiologists with varying experience (p = 0.873).DiscussionOn‐site cytology improved the ND rate of ultrasound‐guided thyroid FNA. Implementation of FNA selection criteria did not alter the rates of Bethesda V and VI cytology and malignant histopathology. The experience of radiologists did not significantly influence ND rates.
Dynamic metabolic control: towards precision engineering of metabolism
Authors: Liu Di , Mannan Ahmad A , Han Yichao , Oyarzún Diego A , Zhang Fuzhong 
Published: January 2018

Abstract
Advances in metabolic engineering have led to the synthesis of a wide variety of valuable chemicals in microorganisms. The key to commercializing these processes is the improvement of titer, productivity, yield, and robustness. Traditional approaches to enhancing production use the “push–pull-block” strategy that modulates enzyme expression under static control. However, strains are often optimized for specific laboratory set-up and are sensitive to environmental fluctuations. Exposure to sub-optimal growth conditions during large-scale fermentation often reduces their production capacity. Moreover, static control of engineered pathways may imbalance cofactors or cause the accumulation of toxic intermediates, which imposes burden on the host and results in decreased production. To overcome these problems, the last decade has witnessed the emergence of a new technology that uses synthetic regulation to control heterologous pathways dynamically, in ways akin to regulatory networks found in nature. Here, we review natural metabolic control strategies and recent developments in how they inspire the engineering of dynamically regulated pathways. We further discuss the challenges of designing and engineering dynamic control and highlight how model-based design can provide a powerful formalism to engineer dynamic control circuits, which together with the tools of synthetic biology, can work to enhance microbial production.
The Changing Safety Net for Low-Income Parents and Their Children: Structural or Cyclical Changes in Income Support Policy?
Authors: Hardy Bradley , Smeeding Timothy , Ziliak James P. 
Published: January 2018

AbstractRefundable tax credits and food assistance are the largest transfer programs available to able-bodied working poor and near-poor families in the United States, and simultaneous participation in these programs has more than doubled since the early 2000s. To understand this growth, we construct a series of two-year panels from the 1981–2013 waves of the Current Population Survey Annual Social and Economic Supplement to estimate the effect of state labor-market conditions, federal and state transfer program policy choices, and household demographics governing joint participation in food and refundable tax credit programs. Overall, changing policy drives much of the increase in the simultaneous, biennial use of food assistance and refundable tax credits. This stands in stark contrast from the factors accounting for the growth in food assistance alone, where cyclical and structural labor market factors account for at least one-half of the growth, and demographics play a more prominent role. Moreover, since 2000, the business cycle factors as the leading determinant in biennial participation decisions in food programs and refundable tax credits, suggesting a recent strengthening in the relationship between economic conditions and transfer programs.
Do we work hard or are we just great? The effects of organizational pride due to effort and ability on proactive behavior
Authors: Brosi Prisca , Spörrle Matthias , Welpe Isabell M. 
Published: January 2018

AbstractThis study derives a conceptual framework for examining parallel and differential influences of organizational pride in employees’ efforts versus abilities on proactivity. Data from a field survey (N = 1218) confirm our theoretical model. Organizational pride in employees’ efforts and organizational pride in employees’ abilities both had positive indirect effects on proactive behaviors via affective organizational commitment. Yet, whereas organizational pride in employees’ efforts additionally had a direct positive effect on individual and team member proactivity, organizational pride in employees’ abilities showed a direct negative effect on proactive behaviors for the self, the team, and the organization including a behavioral measurement of employees’ provision of ideas for improvement. These findings contribute to the nascent literature on organizational pride by indicating towards employees as source of organizational pride, highlighting potential negative effects of organizational pride, and introducing the differentiation between employees’ efforts and abilities.
Computer-assisted learning of communication (CALC): A case study of Japanese learning in a 3D virtual world
Authors: Yamazaki Kasumi 
Published: January 2018

AbstractThis study investigates an instantiation of a 3D virtual world–based Japanese learning curriculum within the context of a Japanese as a foreign language (JFL) classroom. Through a mixed-method case study approach, participants’ natural acquisition of Japanese in a 3D virtual environment was examined. In the present study, four sources of data from 11 university-level JFL students (n=11) were collected and analyzed to evaluate the learning outcomes from a new instructional approach called computer-assisted learning of communication (CALC). Based on both interpretative and statistical analyses of data, the major finding of the present study was that the participants, when immersed in the 3D virtual world of Tokyo, acquired contextualized communicative competence. More specifically, quantitative analyses revealed statistically significant improvement in the participants’ acquisition of incidentally encountered vocabulary, in particular, kanji pronunciation and vocabulary interpretation. Qualitative analyses revealed participants’ acquisition of various communicative competencies specific to the context, including persuasive talk, awareness of audience, and collaborative communication.
Discordant congenital Zika syndrome twins show differential in vitro viral susceptibility of neural progenitor cells
Authors: Caires-Júnior Luiz Carlos , Goulart Ernesto , Melo Uirá Souto , Araujo Bruno Henrique Silva , Alvizi Lucas , Soares-Schanoski Alessandra , de Oliveira Danyllo Felipe , Kobayashi Gerson Shigeru , Griesi-Oliveira Karina , Musso Camila Manso , Amaral Murilo Sena , daSilva Lucas Ferreira , Astray Renato Mancini , Suárez-Patiño Sandra Fernanda , Ventini Daniella Cristina , Gomes da Silva Sérgio , Yamamoto Guilherme Lopes , Ezquina Suzana , Naslavsky Michel Satya , Telles-Silva Kayque Alves , Weinmann Karina , van der Linden Vanessa , van der Linden Helio , de Oliveira João Ricardo Mendes , Arrais Nivia Maria Rodrigues , Melo Adriana , Figueiredo Thalita , Santos Silvana , Meira Joanna Goes Castro , Passos Saulo Duarte , de Almeida Roque Pacheco , Bispo Ana Jovina Barreto , Cavalheiro Esper Abrão , Kalil Jorge , Cunha-Neto Edécio , Nakaya Helder , Andreata-Santos Robert , de Souza Ferreira Luis Carlos , Verjovski-Almeida Sergio , Ho Paulo Lee , Passos-Bueno Maria Rita , Zatz Mayana 
Published: January 2018

AbstractCongenital Zika syndrome (CZS) causes early brain development impairment by affecting neural progenitor cells (NPCs). Here, we analyze NPCs from three pairs of dizygotic twins discordant for CZS. We compare by RNA-Seq the NPCs derived from CZS-affected and CZS-unaffected twins. Prior to Zika virus (ZIKV) infection the NPCs from CZS babies show a significantly different gene expression signature of mTOR and Wnt pathway regulators, key to a neurodevelopmental program. Following ZIKV in vitro infection, cells from affected individuals have significantly higher ZIKV replication and reduced cell growth. Whole-exome analysis in 18 affected CZS babies as compared to 5 unaffected twins and 609 controls excludes a monogenic model to explain resistance or increased susceptibility to CZS development. Overall, our results indicate that CZS is not a stochastic event and depends on NPC intrinsic susceptibility, possibly related to oligogenic and/or epigenetic mechanisms.