bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of a New Fused‐Ring Electron Acceptor with Excellent Compatibility to Wide‐Bandgap Polymer Donors for High‐Performance Organic Photovoltaics
Authors: Liu Wenrui , Zhang Jianyun , Zhou Zichun , Zhang Dongyang , Zhang Yuan , Xu Shengjie , Zhu Xiaozhang 
Published: May 2018

AbstractFused‐ring electron acceptors (FREAs) have recently received intensive attention. Besides the continuing development of new FREAs, the demand for FREAs featuring good compatibility to donor materials is becoming more and more urgent, which is highly desirable for screening donor materials and achieving new breakthroughs. In this work, a new FREA is developed, ZITI, featuring an octacyclic dithienocyclopentaindenoindene central core. The core is designed by linking 2,7‐dithienyl substituents and indenoindene with small methylene groups, in which the indeno[1,2‐b]thiophene‐2‐(3‐oxo‐2,3‐dihydro‐1H‐inden‐1‐ylidene)malononitrile part provides a large and unoccupied π‐surface. Most notably, ZITI possesses an excellent compatibility with commercially available polymer donors, delivering very high power conversion efficiencies of over 13%.
Soft Electronic Strain Sensor with Chipless Wireless Readout: Toward Real‐Time Monitoring of Bladder Volume
Authors: Stauffer Flurin , Zhang Qiang , Tybrandt Klas , Llerena Zambrano Byron , Hengsteler Julian , Stoll André , Trüeb Camill , Hagander Michael , Sujata Jean‐Marc , Hoffmann Felix , Schuurmans Stekhoven Joy , Quack Josefine , Zilly Hannes , Goedejohann Johannes , Schneider Marc P. , Kessler Thomas M. , Taylor William R. , Küng Roland , Vörös János 
Published: May 2018

AbstractSensing mechanical tissue deformation in vivo can provide detailed information on organ functionality and tissue states. To bridge the huge mechanical mismatch between conventional electronics and biological tissues, stretchable electronic systems have recently been developed for interfacing tissues in healthcare applications. A major challenge for wireless electronic implants is that they typically require microchips, which adds complexity and may compromise long‐term stability. Here, a chipless wireless strain sensor technology based on a novel soft conductor with high cyclic stability is reported. The composite material consists of gold‐coated titanium dioxide nanowires embedded in a soft silicone elastomer. The implantable strain sensor is based on an resonant circuit which consists of a stretchable plate capacitor and a coil for inductive readout of its resonance frequency. Successful continuous wireless readout during 50% strain cycles is demonstrated. The sensor element has a Young's modulus of 260 kPa, similar to that of the bladder in order to not impair physiological bladder expansion. A proof‐of‐principle measurement on an ex vivo porcine bladder is presented, which shows the feasibility of the presented materials and devices for continuous, wireless strain monitoring of various tissues and organs in vivo.
Fast Adaptive Thermal Buffering by a Passive Open Shell Based on Transformation Thermodynamics
Authors: Liu Yichao , Sun Fei , He Sailing 
Published: May 2018

AbstractBy using transformation thermodynamics, an open, adaptive thermal buffer shell (TBS) is designed and experimentally implemented with natural materials (layered copper and expanded polystyrene [EPS]). The TBS can store excessive heat flux quickly in the shell and release it slowly when it is needed, which also has some distinctive features: first it is a buffer shell that can avoid external extremes in temperature (either high or low) and also provide a relatively stable temperature for the interior of the shell when the temperature outside the shell has some fluctuations; second the TBS is not thermally insulated (with holes connected to the outside world) and the buffering effect of the TBS originates from the heat recycling mechanics, not thermal insulation; third the TBS has a short response time and the temperature inside the shell can be quickly adjusted according to the average temperature outside the shell; fourth the TBS is a passive device. Unlike traditional air conditioning, the TBS can work without an external power supply. The TBS will have many applications in energy recycling systems, smart heat controlling systems, and passive heat self‐adaptation systems. Numerical simulations and experimental demonstrations are given to verify the function of the TBS.
Relationship between fractal dimensions of fracture surface and impact toughness of polycaprolactone/nano‐CaCO3 composites
Authors: Liang Ji‐Zhao 
Published: May 2018

AbstractThe fractal dimensions of the specimen impact fracture surface of nanosized calcium carbonate reinforced polycaprolactone (PCL) composites were determined using a structure‐function method; and the correlation between V‐notched Izod impact strength measured at room temperature and fractal dimensions was studied. It was found that the fractal dimension range of the specimen fracture surface was from about 1.918 to 1.967, and all of the correlation coefficients were higher than 0.9. There was a strong relationship between the fracture surface fractal dimension and the impact strength. It indicated that the specimen fracture surface of the composites had obvious fractal character, the measured impact strength increased with increasing the fracture surface fractal dimension, and the correlation between them obeyed a three‐order polynomial equation. In addition, the toughening mechanisms of the PCL nanocomposites were discussed.
Electrical Transport in Devices Based on Edge‐Fluorinated Graphene
Authors: Koleśnik‐Gray Maria , Sysoev Vitalii I. , Gollwitzer Stefan , Pinakov Dmitry V. , Chekhova Galina N. , Bulusheva Lyubov G. , Okotrub Alexander V. , Krstić Vojislav 
Published: May 2018

AbstractThe conductivity of few‐ and monolayer graphene with covalently bound moieties is a key‐point in the potential application of these materials in any electrical and optoelectronic device. In particular, fluorination of such graphene‐based systems is of interest, as fluorine is expected to have a strong influence on the charge‐carrier density due to its high electronegativity, and therefore modify the electrical transport properties significantly. Here it is shown that, depending on the device architecture, the electrical properties of fluorinated graphene‐based devices are significantly different. It is found that the conductivity of thin films of few‐layer graphene decreases by several orders of magnitude with fluorine content increasing from 2.4 to 16.6 at%, whereas individual flakes show a significant increase in both conductivity and charge carrier mobility. This observation, combined with Raman microscopy study, points toward the fact that the edges of the flakes are primary sites for fluorine within the experimental range of fluorine content. The strong decrease in conductivity in the film devices is therefore associated with the high contact resistance between the fluorine saturated edges of the individual flakes.
Open sepulchers and closed boundaries? Biodistance analysis of cemetery structure and postmarital residence in the late prehispanic Andes
Authors: Velasco Matthew C. 
Published: May 2018

AbstractObjectivesIn the Late Intermediate Period Andes (AD 1100–1450), the proliferation of above‐ground sepulchers reconfigured social boundaries within and between communities engaged in protracted conflict. However, the biosocial dimensions of these mortuary practices, and their implications for conflict and alliance formation, remain unexplored. This study examines patterns of phenotypic variation to: (1) evaluate if open sepulchers were organized on the basis of biological relatedness, and (2) explore if sex‐specific phenotypic variability conforms to models of postmarital residence.Materials and methodsCranial nonmetric traits were recorded in five skeletal samples from two cemeteries in the Colca Valley, Peru. Biological distances between burial groups were calculated using the Mean Measure of Divergence (MMD) statistic. Postmarital residence was explored by calculating and bootstrapping the ratio of male‐to‐female mean pairwise differences (MPD) at the within‐group level.ResultsThe MMD analysis yields greater than expected between‐group distances for burial groups with a minimum sample size of 20 individuals. In contrast, a prevailing pattern of sex‐specific, within‐group phenotypic variability is not apparent from the analysis of MPD. The use of 12 or 24 dichotomous traits produces similar results.DiscussionGreater than expected biological distances suggest that above‐ground mortuary practices reinforced biosocial boundaries between corporate household groups. Intracemetery heterogeneity persisted even as cranial vault modification, a correlate of social identity, became more homogenous, revealing how corporate group organization was negotiated at multiple scales. Sex‐specific variation does not conform to traditional migration models. If migration occurred, it did not have a homogenizing effect on phenotypic variation. These results should be viewed with caution in light of the smaller sample sizes of sex‐specific groupings.
Dynamic Ultralong Organic Phosphorescence by Photoactivation
Authors: Gu Long , Shi Huifang , Gu Mingxing , Ling Kun , Ma Huili , Cai Suzhi , Song Lulu , Ma Chaoqun , Li Hai , Xing Guichuan , Hang Xiaochun , Li Jiewei , Gao Yaru , Yao Wei , Shuai Zhigang , An Zhongfu , Liu Xiaogang , Huang Wei 
Published: May 2018

AbstractSmart materials with ultralong phosphorescence are rarely investigated and reported. Herein we report on a series of molecules with unique dynamic ultralong organic phosphorescence (UOP) features, enabled by manipulating intermolecular interactions through UV light irradiation. Our experimental data reveal that prolonged irradiation of single‐component organic phosphors of PCzT, BCzT, and FCzT under ambient conditions can activate UOP with emission lifetimes spanning from 1.8 to 1330 ms. These phosphors can also be deactivated back to their original states with short‐lived phosphorescence by UV irradiation for 3 h at room temperature or through thermal treatment. Additionally, the dynamic UOP was applied successfully for a visual anti‐counterfeiting application. These findings may provide unique insight into dynamic molecular motion for optical processing and expand the scope of smart‐response materials for broader applications.
Bismesitoylphosphinic Acid (BAPO‐OH): A Ligand for Copper Complexes and Four‐Electron Photoreductant for the Preparation of Copper Nanomaterials
Authors: Beil Andreas , Müller Georgina , Käser Debora , Hattendorf Bodo , Li Zhongshu , Krumeich Frank , Rosenthal Amos , Rana Vijay Kumar , Schönberg Hartmut , Benkő Zoltán , Grützmacher Hansjörg 
Published: May 2018

AbstractBismesitoylphosphinic acid, (HO)PO(COMes)2 (BAPO‐OH), is an efficient photoinitiator for free‐radical polymerizations of olefins in aqueous phase. Described here are the structures of various copper(II) and copper(I) complexes with BAPO‐OH as the ligand. The complex CuII(BAPO‐O)2(H2O)2 is photoactive, and under irradiation with UV light in aqueous phase, it serves as a source of metallic copper in high purity and yield (>80 %). Simultaneously, the radical polymerization of acrylates can be initiated and allows the preparation of nanoparticle/polymer nanocomposites in which the metallic Cu nanoparticles are protected against oxidation. The determination of the stoichiometry of the photoreductions suggests an almost quantitative conversion from CuII into Cu0 with half an equivalent of BAPO‐OH, which serves as a four‐electron photoreductant.
Optimizing Antimicrobial Peptide Dendrimers in Chemical Space
Authors: Siriwardena Thissa N. , Capecchi Alice , Gan Bee‐Ha , Jin Xian , He Runze , Wei Dengwen , Ma Lan , Köhler Thilo , van Delden Christian , Javor Sacha , Reymond Jean‐Louis 
Published: May 2018

AbstractWe used nearest‐neighbor searches in chemical space to improve the activity of the antimicrobial peptide dendrimer (AMPD) G3KL and identified dendrimer T7, which has an expanded activity range against Gram‐negative pathogenic bacteria including Klebsiellae pneumoniae, increased serum stability, and promising activity in an in vivo infection model against a multidrug‐resistant strain of Acinetobacter baumannii. Imaging, spectroscopic studies, and a structural model from molecular dynamics simulations suggest that T7 acts through membrane disruption. These experiments provide the first example of using virtual screening in the field of dendrimers and show that dendrimer size does not limit the activity of AMPDs.
Lower Activation Energy for Catalytic Reactions through Host–Guest Cooperation within Metal–Organic Frameworks
Authors: Aguila Briana , Sun Qi , Wang Xiaoliang , O'Rourke Erica , Al‐Enizi Abdullah M. , Nafady Ayman , Ma Shengqian 
Published: May 2018

AbstractIndustrial synthesis is driven by a delicate balance of the value of the product against the cost of production. Catalysts are often employed to ensure product turnover is economically favorable by ensuring energy use is minimized. One method, which is gaining attention, involves cooperative catalytic systems. By inserting a flexible polymer into a metal–organic framework (MOF) host, the advantages of both components work synergistically to create a composite that efficiently fixes carbon dioxide to transform various epoxides into cyclic carbonates. The resulting material retains high yields under mild conditions with full reusability. By quantitatively studying the kinetic rates, the activation energy was calculated, for a physical mixture of the catalyst components to be about 50 % higher than that of the composite. Through the unification of two catalytically active components, a new opportunity opens up for the development of synergistic systems in multiple applications.
Remote Central‐to‐Axial Chirality Conversion: Direct Atroposelective Ester to Biaryl Transformation
Authors: Link Achim , Sparr Christof 
Published: May 2018

AbstractA strategy for the remote central‐to‐axial chirality conversion by simultaneous planarization of an encoding and a transient stereocenter is presented. Based on a diastereoselective double addition of a chiral 1,5‐bifunctional organomagnesium alkoxide reagent to a broad range of aryl ester substrates, axially chiral biaryls are directly obtained upon in situ reduction. Various structurally distinct atropisomeric biaryl silanes that serve as valuable chiral biaryl anion surrogates are accessible in one step with e.r. values of up to 98:2.
Prototypen‐Entwicklung von Instrumenten für das chemische Laboratorium mithilfe von preiswerten Elektronikmodulen
Authors: Urban Pawel L. 
Published: May 2018

AbstractQuelloffene Elektronik und Programmierung können für die chemische und biomedizinische Forschung einen erheblichen Nutzen bringen. Derzeit können Chemiker aus einem breiten Spektrum an günstigen universellen Elektronikmodulen (Mikrocontroller‐Boards oder Single‐Board‐Computern) auswählen und damit wissenschaftliche Instrumente als Prototypen bauen, um experimentelle Probleme zu lösen und die tägliche Forschungsarbeit zu unterstützen. Bei oft nur wenigen Stunden Einarbeitungszeit beträgt das Budget dafür manchmal nur 50 US‐Dollar. Bei der Prototypen‐Entwicklung mit preiswerten Elektronikmodulen haben Chemiker eine große Gestaltungsfreiheit in der Entwicklung von individueller, speziell angepasster Instrumentierung. Verzögerungen durch anspruchsvolle Plattformen, die nicht sofort zur Verfügung stehen, lassen sich vermeiden.
MOF Scaffold for a High‐Performance Mixed‐Matrix Membrane
Authors: Xie Ke , Fu Qiang , Webley Paul A. , Qiao Greg G. 
Published: May 2018

AbstractA novel composite membrane consisting of an interconnected MOF scaffold coated with cross‐linked poly(ethylene glycol) (PEG) has been developed. As a result of its unique structure, the membrane shows an exceptional 18‐fold permeability enhancement as compared to pristine PEG membranes, without compromising the selectivity. This performance is unattainable with current mixed‐matrix membranes (MMMs). Our optimized membrane has a permeability of 2700 Barrer with a CO2/N2 selectivity of 35, which surpasses the latest Robeson upper bound.
Enantioselective Synthesis of Chiral Cyclopent‐2‐enones by Nickel‐Catalyzed Desymmetrization of Malonate Esters
Authors: Karad Somnath Narayan , Panchal Heena , Clarke Christopher , Lewis William , Lam Hon Wai 
Published: May 2018

AbstractThe enantioselective synthesis of highly functionalized chiral cyclopent‐2‐enones by the reaction of alkynyl malonate esters with arylboronic acids is described. These desymmetrizing arylative cyclizations are catalyzed by a chiral phosphinooxazoline/nickel complex, and cyclization is enabled by the reversible E/Z isomerization of alkenylnickel species. The general methodology is also applicable to the synthesis of 1,6‐dihydropyridin‐3(2H)‐ones.
A Cocatalyst that Stabilizes a Hydride Intermediate during Photocatalytic Hydrogen Evolution over a Rhodium‐Doped TiO2 Nanosheet
Authors: Ida Shintaro , Sato Kenta , Nagata Tetsuya , Hagiwara Hidehisa , Watanabe Motonori , Kim Namhoon , Shiota Yoshihito , Koinuma Michio , Takenaka Sakae , Sakai Takaaki , Ertekin Elif , Ishihara Tatsumi 
Published: May 2018

AbstractThe hydrogen evolution reaction using semiconductor photocatalysts has been significantly improved by cocatalyst loading. However, there are still many speculations regarding the actual role of the cocatalyst. Now a photocatalytic hydrogen evolution reaction pathway is reported on a cocatalyst site using TiO2 nanosheets doped with Rh at Ti sites as one‐atom cocatalysts. A hydride species adsorbed on the one‐atom Rh dopant cocatalyst site was confirmed experimentally as the intermediate state for hydrogen evolution, which was consistent with the results of density functional theory (DFT) calculations. In this system, the role of the cocatalyst in photocatalytic hydrogen evolution is related to the withdrawal of photo‐excited electrons and stabilization of the hydride intermediate species; the presence of oxygen vacancies induced by Rh facilitate the withdrawal of electrons and stabilization of the hydride.
The Important Role of the Byproduct Triphenylphosphine Oxide in the Magnesium(II)‐Catalyzed Enantioselective Reaction of Hemiacetals and Phosphorus Ylides
Authors: Wang Linqing , Yang Dongxu , Li Dan , Liu Xihong , Wang Pengxin , Wang Kezhou , Zhu Haiyong , Bai Lutao , Wang Rui 
Published: May 2018

AbstractBy employing a simple in situ generated magnesium catalyst, a direct asymmetric reaction between hemiacetals and phosphorus ylides was achieved through a tandem Wittig–oxa‐Michael reaction sequence. Enantioenriched chromans, isochromans, and tetrahydropyrans were obtained in good chemical yields, and (−)‐erythrococcamide B was synthesized in enantioenriched form. The byproduct triphenylphosphine oxide was identified as a necessary additive for this process.
Syntheses and Immunological Evaluation of Self‐Adjuvanting Clustered N‐Acetyl and N‐Propionyl Sialyl‐Tn Combined with a T‐helper Cell Epitope as Antitumor Vaccine Candidates
Authors: Chang Tsung‐Che , Manabe Yoshiyuki , Fujimoto Yukari , Ohshima Shino , Kametani Yoshie , Kabayama Kazuya , Nimura Yuka , Lin Chun‐Cheng , Fukase Koichi 
Published: May 2018

AbstractSialyl‐Tn (STn) is a tumor‐associated carbohydrate antigen (TACA) rarely observed on healthy tissues. We synthesized two fully synthetic N‐acetyl and N‐propionyl STn trimer (triSTn) vaccines possessing a T‐helper epitope and a TLR2 agonist, since the clustered STn antigens are highly expressed on many cancer cells. Immunization of both vaccines in mice induced the anti‐triSTn IgG antibodies, which recognized triSTn‐expressing cell lines PANC‐1 and HepG2. The N‐propionyl triSTn vaccine induced the triSTn‐specific IgGs, while IgGs induced by the N‐acetyl triSTn vaccine were less specific. These results illustrated that N‐propionyl triSTn is a valuable unnatural TACA for anticancer vaccines.
Analyzing self‐controlled case series data when case confirmation rates are estimated from an internal validation sample
Authors: Xu Stanley , Clarke Christina L. , Newcomer Sophia R. , Daley Matthew F. , Glanz Jason M. 
Published: May 2018

AbstractVaccine safety studies are often electronic health record (EHR)‐based observational studies. These studies often face significant methodological challenges, including confounding and misclassification of adverse event. Vaccine safety researchers use self‐controlled case series (SCCS) study design to handle confounding effect and employ medical chart review to ascertain cases that are identified using EHR data. However, for common adverse events, limited resources often make it impossible to adjudicate all adverse events observed in electronic data. In this paper, we considered four approaches for analyzing SCCS data with confirmation rates estimated from an internal validation sample: (1) observed cases, (2) confirmed cases only, (3) known confirmation rate, and (4) multiple imputation (MI). We conducted a simulation study to evaluate these four approaches using type I error rates, percent bias, and empirical power. Our simulation results suggest that when misclassification of adverse events is present, approaches such as observed cases, confirmed case only, and known confirmation rate may inflate the type I error, yield biased point estimates, and affect statistical power. The multiple imputation approach considers the uncertainty of estimated confirmation rates from an internal validation sample, yields a proper type I error rate, largely unbiased point estimate, proper variance estimate, and statistical power.
Utilizing two detectors in the measurement of trichloroacetic acid in human urine by reaction headspace gas chromatography
Authors: Xie Wei‐Qi , Gong Yi‐Xian , Yu Kong‐Xian 
Published: May 2018

AbstractA reaction headspace gas chromatography (HS‐GC) technique was investigated for quantitatively analyzing trichloroacetic acid in human urine. This method is based on the decomposition reaction of trichloroacetic acid under high‐temperature conditions. The carbon dioxide and chloroform formed from the decomposition reaction can be respectively detected by the thermal conductivity detection HS‐GC and flame ionization detection HS‐GC. The reaction can be completed in 60 min at 90°C. This method was used to quantify 25 different human urine samples, which had a range of trichloroacetic acid from 0.52 to 3.47 mg/L. It also utilized two different detectors, the thermal conductivity detector and the flame ionization detector. The present reaction HS‐GC method is accurate, reliable and well suitable for batch detection of trichloroacetic acid in human urine.