bluuebunny/crossref_metadata_2025_split huggingface dataset:
Applications of Nanomaterials in Asymmetric Photocatalysis: Recent Progress, Challenges, and Opportunities
Authors: Qiu Xueying , Zhang Yin , Zhu Yanfei , Long Chang , Su Lina , Liu Shaoqin , Tang Zhiyong 
Published: July 2020

AbstractAsymmetric catalysis is one of the most attractive strategies to obtain important enantiomerically pure chemicals with high quality and production. In addition, thanks to the abundant and sustainable advantages of solar energy, photocatalysis possesses great potential in environmentally benign reactions. Undoubtedly, asymmetric photocatalysis meets the strict demand of modern chemistry: environmentally friendly and energy‐sustainable alternatives. Compared with homogeneous asymmetric photocatalysis, heterogeneous catalysis has features of easy separation, recovery, and reuse merits, thus being cost‐ and time‐effective. Herein, the state‐of‐the‐art progress in asymmetric photocatalysis by heterogeneous nanomaterials is addressed. The discussion comprises two sections based on the type of nanomaterials: typical inorganic semiconductors like TiO2 and quantum dots and emerging porous materials including metal–organic frameworks, porous organic polymers, and organic cages. Finally, the challenges and future developments of heterogeneous asymmetric photocatalysis are proposed.
A Genetic Algorithm Approach to Design Principles for Organic Photovoltaic Materials
Authors: de Sousa Leonardo Evaristo , da Silva Filho Demétrio Antônio , de Silva Piotr , Ribeiro Luciano , de Oliveira Neto Pedro Henrique 
Published: July 2020

AbstractThe increase in the efficiency of organic photovoltaic (OPV) devices relies on understanding the underlying science of several interconnected physical mechanisms that prevent the success of 1D optimization strategies. Here, a combination of kinetic Monte Carlo simulations of exciton dynamics with a genetic algorithm to automatically optimize the external quantum efficiency of donor–acceptor interfaces under different scenarios is employed. Simulations include phenomena from light absorption to exciton diffusion, dissociation, radiative recombination, and internal conversion, thus modeling the main physical processes that define the overall efficiency of an OPV up to charge separation. It is shown that when internal conversion is kept in check, the combination of optimal transition dipole moments and absorption energies points at low bandgap polymers as the most promising candidates for donor materials. However, when non‐radiative deexcitation mechanisms are stronger, the optimization strategy shifts toward higher bandgaps, focusing rather on increasing the fluorescence quantum yield of the donor. Finally, the approach shows that adjusting the energy levels of the acceptor so that exciton transfers across the interface become negligible produces important gains in efficiency and at the same time reduces the system's dependence on large electronic couplings. The findings indicate pathways for engineering highly efficient organic interfaces.
Comproportionation Reaction Synthesis to Realize High‐Performance Water‐Induced Metal‐Oxide Thin‐Film Transistors
Authors: Liu Qihan , Zhao Chun , Mitrovic Ivona Z. , Xu Wangying , Yang Li , Zhao Ce Zhou 
Published: July 2020

AbstractSolution‐processed metal‐oxide thin films have been widely studied in low‐power and flexible electronics. However, the high temperature required to form a condensed and uniform film limits their applications in flexible and low‐cost electronics. Here, a novel and environmental‐friendly comproportionation reaction synthesis (CRS) is presented to obtain amorphous aluminum oxide (AlOx) thin films for solution‐processed thin‐film transistors (TFTs) employing water as the precursor solvent. The thermal decomposition of CRS‐AlOx precursor is completed at ≈300 °C, which is 100 °C lower than that of the conventional water‐induced AlOx. The morphological, optical, compositional, and electrical properties of CRS‐AlOx dielectric films are studied systematically. Meanwhile, TFTs based on water‐induced In2O3 metal oxide semiconductor layers deposited on these dielectrics at low temperatures are formed and characterized. Compared with TFTs based on conventional AlOx showing low mobility and low clockwise hysteresis, In2O3 TFTs based on CRS‐AlOx exhibit improved electrical performance and counterclockwise hysteresis in the transfer curves. Water‐induced TFTs fabricated on CRS‐AlOx formed at a low temperature of 250 °C have average mobility of 98 cm2 V−1 s−1. Through chemical composition characterization and electrical characterization, the high mobilities of TFTs based on CRS‐AlOx dielectrics are correlated to trap states, which resulted in counterclockwise hysteresis in the transfer curves.
Skin Conformal and Antibacterial PPy‐Leather Electrode for ECG Monitoring
Authors: Zhang Kang , Kang Naiwen , Zhang Bo , Xie Ruijie , Zhu Jingyu , Zou Binghua , Liu Yihan , Chen Yuanyuan , Shi Wei , Zhang Weina , Huang Wei , Wu Jiansheng , Huo Fengwei 
Published: July 2020

AbstractThe commonly used electrocardiogram monitoring electrodes (hydrogel electrodes, fabric electrodes, etc.) suffer from fast degradation of signal quality due to water loss. Therefore, such electrodes are not suitable for long‐term monitoring. Herein, the conductive polymer polypyrrole (PPy) is polymerized in situ on goat leather, and the obtained conductive leather is used as a wearable dry electrode to contact human skin and collect electrophysiological signals for daily health monitoring. Because of its own surface structure, the wearable dry leather electrode obtained by a simple method can form a conformal contact with the skin to reduce noise during electrical signal acquisition. In addition, PPy‐leather electrodes have good antibacterial properties and are more breathable and comfortable than the commercial Ag/AgCl gel electrode. Such an electrode is more suitable for long‐term health monitoring.
Academic and Professional Outcomes of Participants in an Emergency Department Research Associate Program
Authors: Liu Michelle , Nobay Flavia , Adler David , Wood Nancy , Abar Beau 
Published: July 2020

AbstractObjectivesStudies have found that participation in emergency department research associate (EDRA) programs is associated with medical school acceptance. However, little is known about the association between EDRA program participation and other academic and professional outcomes. We sought to characterize the academic and professional outcomes of EDRA program participants and their perception of program influence on academic and professional outcomes.MethodsWe conducted a cross‐sectional study of University of Rochester EDRA program participants who graduated from the program May 2010 to May 2017. EDRAs were sent a secure, deidentified, survey. Standard descriptive statistics were used to characterize participant demographics and outcomes. National acceptance rates were referenced from sources.ResultsA total of 56 graduates completed the survey (64% response rate). Forty (71%) identified as female, 12 (21%) identified as Asian, one (2%) identified as Black or African American, and three (5%) identified as Hispanic or Latino. Acceptance rates to MD programs, DO programs, PhD programs, and master’s programs were 88% (22/25), 92% (12/13), 100% (2/2), and 100% (9/9), respectively. Rates were significantly higher compared to national rates (all p < 0.001). Eighty‐three percent (30/36 responses) and 74% (37/50) spoke about the EDRA program during postgraduate program and job interviews, respectively, and 78% (35/45 responses) included the EDRA program in their personal statements. Twenty‐five percent (14/55) changed their career goals after participating in the EDRA program, of which 36% (5/14) left medicine and 21% (3/14) were undecided and chose to become a physician.ConclusionsAn EDRA program can help develop and support a career in medicine and science. EDRA graduates used their experiences directly in their postgraduate program applications and job interviews. Acceptance rates of EDRA program graduates to postgraduate programs were higher than national averages. An EDRA program can help clarify career goals after program participation.
Electroreduction of CO2 to Formate with Low Overpotential using Cobalt Pyridine Thiolate Complexes
Authors: Dey Subal , Todorova Tanya K. , Fontecave Marc , Mougel Victor 
Published: July 2020

AbstractElectrocatalytic CO2 reduction to value‐added products provides a viable alternative to the use of carbon sources derived from fossil fuels. Carrying out these transformations at reasonable energetic costs, for example, with low overpotential, remains a challenge. Molecular catalysts allow fine control of activity and selectivity via tuning of their coordination sphere and ligand set. Herein we investigate a series of cobalt(III) pyridine‐thiolate complexes as electrocatalysts for CO2 reduction. The effect of the ligands and proton sources on activity was examined. We identified bipyridine bis(2‐pyridinethiolato) cobalt(III) hexaflurophosphate as a highly selective catalyst for formate production operating at a low overpotential of 110 mV with a turnover frequency (TOF) of 10 s−1. Electrokinetic analysis coupled with density functional theory (DFT) computations established the mechanistic pathway, highlighting the role of metal hydride intermediates. The catalysts deactivate via the formation of stable cobalt carbonyl complexes, but the active species could be regenerated upon oxidation and release of coordinated CO ligands.
Asymmetric Synthesis of Alkylzincs by Rhodium‐Catalyzed Enantioselective Arylative Cyclization of 1,6‐Enynes with Arylzincs
Authors: Chen Jiahua , Hayashi Tamio 
Published: July 2020

AbstractA chiral diene‐rhodium complex was found to catalyze the reaction of 1,6‐enynes with ArZnCl to give high yields of 2‐(alkylidene)cyclopentylmethylzincs with high enantioselectivity (95–99 %ee). The enantioenriched alkylzincs were readily converted in a one‐pot approach into a wide variety of functionalized products by taking advantage of their unique reactivity. The catalytic cylcle involves arylrhodation of alkyne, intramolecular alkenylrhodation of alkene, and transmetalation of the alkyl‐rhodium intermediate into alkylzinc.
Holistic Prediction of the pKa in Diverse Solvents Based on a Machine‐Learning Approach
Authors: Yang Qi , Li Yao , Yang Jin‐Dong , Liu Yidi , Zhang Long , Luo Sanzhong , Cheng Jin‐Pei 
Published: July 2020

AbstractWhile many approaches to predict aqueous pKa values exist, the fast and accurate prediction of non‐aqueous pKa values is still challenging. Based on the iBonD experimental pKa database (39 solvents), a holistic pKa prediction model was established using machine learning. Structural and physical‐organic‐parameter‐based descriptors (SPOC) were introduced to represent the electronic and structural features of the molecules. The models trained with a neural network or the XGBoost algorithm showed the best prediction performance with a low MAE value of 0.87 pKa units. The approach allows a comprehensive mapping of all possible pKa correlations between different solvents and it was validated by predicting the aqueous pKa and micro‐pKa of pharmaceutical molecules and pKa values of organocatalysts in DMSO and MeCN with high accuracy. An online prediction platform was constructed based on the current model, which can provide pKa prediction for different types of X−H acidity in the most commonly used solvents.
Continuous facial myokymia in multiple sclerosis
Authors: Clay Jordan L. , Villamar Mauricio F. 
Published: July 2020

AbstractFacial myokymia is a clinical sign that can occur as a manifestation of demyelinating lesions. As seen in our patient with multiple sclerosis, acute‐onset continuous facial myokymia can be indicative of an active lesion and can have localizing value.
Structures and Chemical Bonding in Antimony(III) Bromide Complexes with Pyridine
Authors: Prokudina Yana V. , Davydova Elena I. , Virovets Alexander , Stöger Berthold , Peresypkina Eugenia , Pomogaeva Anna V. , Timoshkin Alexey Y. 
Published: July 2020

AbstractWeakly or “partially” bonded molecules are an important link between the chemical and van der Waals interactions. Molecular structures of six new SbBr3‐Py complexes in the solid state have been determined by single‐crystal X‐ray diffraction analysis. In all complexes all Sb atoms adopt a pseudo‐octahedral coordination geometry which is completed by additional Sb⋅⋅⋅Br contacts shorter than the sum of the van der Waals radii, with Br−Sb⋅⋅⋅Br angles close to 180°. To reveal the nature of Sb–Br and Sb–N interactions, the DFT calculations were performed followed by the analysis of the electrostatic potentials, the orbital interactions and the topological analysis. Based on Natural Bond Orbital (NBO) analysis, the Sb–Br interactions range from the covalent bonds to the pnictogen bonds. A simple structural parameter, non‐covalence criterion (NCC) is defined as a ratio of the atom‐atom distance to the linear combination of sums of covalent and van der Waals radii. NCC correlates with E(2) values for Sb−N, Sb−Cl and Sb−Br bonds, and appears to be useful criterion for a preliminary evaluation of the bonding situation.
Growth of ZIF‐8 MOF Films with Tunable Porosity by using Poly (1‐vinylimidazole) Brushes as 3D Primers
Authors: Allegretto Juan A. , Iborra Agustín , Giussi Juan M. , von Bilderling Catalina , Ceolín Marcelo , Moya Sergio , Azzaroni Omar , Rafti Matias 
Published: July 2020

AbstractThis work reports on a novel and versatile approach to control the structure of metal–organic framework (MOFs) films by using polymeric brushes as 3D primers, suitable for triggering heterogeneous MOF nucleation. As a proof‐of‐concept, this work explores the use of poly(1‐vinylimidazole) brushes primer obtained via surface‐initiated atom transfer radical polymerization (SI‐ATRP) for the synthesis of Zn‐based ZIF‐8 MOF films. By modifying the grafting density of the brushes, smooth porous films were obtained featuring inherently hydrophobic microporosity arising from ZIF‐8 structure, and an additional constructional interparticle mesoporosity, which can be employed for differential adsorption of targeted adsorbates. It was found that the grafting density modulates the constructional porosity of the films obtained; higher grafting densities result in more compact structures, while lower grafting density generates increasingly inhomogeneous films with a higher proportion of interparticle constructional porosity.
A Photochemical/Thermal Switch Based on 4,4′‐Bis(benzimidazolio)stilbene: Synthesis and Supramolecular Properties.
Authors: Kulkarni Shantanu Ganesh , Jelínková Kristýna , Nečas Marek , Prucková Zdeňka , Rouchal Michal , Dastychová Lenka , Kulhánek Petr , Vícha Robert 
Published: July 2020

AbstractStilbene derivatives are well‐recognised substructures of molecular switches based on photochemically and/or thermally induced (E)/(Z) isomerisation. We combined a stilbene motif with two benzimidazolium arms to prepare new sorts of supramolecular building blocks and examined their binding properties towards cucurbit[n]urils (n=7, 8) and cyclodextrins (β‐CD, γ‐CD) in water. Based on the 1H NMR data and molecular dynamics simulations, we found that two distinct complexes with different stoichiometry, i. e., guest@β‐CD and guest@β‐CD2, coexist in equilibrium in a water solution of the (Z)‐stilbene‐based guests. We also demonstrated that the bis(benzimidazolio)stilbene guests can be transformed from the (E) into the (Z) form via UV irradiation and back via thermal treatment in DMSO.
Climate dependent heating efficiency in the common lizard
Authors: Rutschmann Alexis , Rozen‐Rechels David , Dupoué Andréaz , Blaimont Pauline , de Villemereuil Pierre , Miles Donald B. , Richard Murielle , Clobert Jean 
Published: July 2020

AbstractRegulation of body temperature is crucial for optimizing physiological performance in ectotherms but imposes constraints in time and energy. Time and energy spent thermoregulating can be reduced through behavioral (e.g., basking adjustments) or biophysical (e.g., heating rate physiology) means. In a heterogeneous environment, we expect thermoregulation costs to vary according to local, climatic conditions and therefore to drive the evolution of both behavioral and biophysical thermoregulation. To date, there are limited data showing that thermal physiological adjustments have a direct relationship to climatic conditions. In this study, we explored the effect of environmental conditions on heating rates in the common lizard (Zootoca vivipara). We sampled lizards from 10 populations in the Massif Central Mountain range of France and measured whether differences in heating rates of individuals correlated with phenotypic traits (i.e., body condition and dorsal darkness) or abiotic factors (temperature and rainfall). Our results show that heat gain is faster for lizards with a higher body condition, but also for individuals from habitats with higher amount of precipitation. Altogether, they demonstrate that environmentally induced constraints can shape biophysical aspects of thermoregulation.
Vav family proteins constitute disparate branching points for distinct BCR signaling pathways
Authors: Löber Jens , Hitzing Christoffer , Münchhalfen Matthias , Engels Niklas 
Published: July 2020

AbstractAntigen recognition by B‐cell antigen receptors (BCRs) activates distinct intracellular signaling pathways that control the differentiation fate of activated B lymphocytes. BCR‐proximal signaling enzymes comprise protein tyrosine kinases, phosphatases, and plasma membrane lipid‐modifying enzymes, whose function is furthermore coordinated by catalytically inert adaptor proteins. Here, we show that an additional class of enzymatic activity provided by guanine‐nucleotide exchange factors (GEFs) of the Vav family controls BCR‐proximal Ca2+ mobilization, cytoskeletal actin reorganization, and activation of the PI3 kinase/Akt pathway. Whereas Vav1 and Vav3 supported all of those signaling processes to different extents in a human B‐cell model system, Vav2 facilitated Actin remodeling, and activation of Akt but did not promote Ca2+ signaling. On BCR activation, Vav1 was directly recruited to the phosphorylated BCR and to the central adaptor protein SLP65 via its Src homology 2 domain. Pharmacological inhibition or genetic inactivation of the substrates of Vav GEFs, small G proteins of the Rho/Rac family, impaired BCR‐induced Ca2+ mobilization, probably because phospholipase Cγ2 requires activated Rac proteins for optimal activity. Our findings show that Vav family members are key relays of the BCR signalosome that differentially control distinct signaling pathways both in a catalysis‐dependent and ‐independent manner.
Natural Course of Pediatric Portal Hypertension
Authors: Kassam Al‐Faraaz , Goddard Gillian R. , Johnston Michael E. , Cortez Alexander R. , Trout Andrew T. , Jenkins Todd M. , Miethke Alexander G. , Campbell Kathleen M. , Bezerra Jorge A. , Balistreri William F. , Nathan Jaimie D. , Alonso Maria H. , Tiao Gregory M. , Bondoc Alexander J. 
Published: July 2020

The etiology of portal hypertension (pHTN) in children differs from that of adults and may require different management strategies. We set out to review the etiology, management, and natural history of pHTN at a pediatric liver center. From 2008 to 2018, 151 children and adolescents with pHTN were identified at a free‐standing children’s hospital. Patients were stratified by etiology of pHTN (intrahepatic disease [IH], defined as cholestatic disease and fibrotic or hepatocellular disease; extrahepatic disease [EH], defined as hepatic vein obstruction and prehepatic pHTN). Patients with EH were more likely to undergo an esophagoduodenscopy for a suspected gastrointestinal bleed (77% vs. 41%; P < 0.01). Surgical interventions differed based on etiology (P < 0.01), with IH more likely resulting in a transplant only (65%) and EH more likely to result in a shunt only (43%); 30% of patients with IH and 47% of patients with EH did not undergo an intervention for pHTN. Kaplan‐Meier analysis revealed a significant increase in mortality in the group that received no intervention compared to shunt, transplant, or both and lower mortality in patients with prehepatic pHTN compared to other etiologies (P < 0.01 each). Multivariate analysis revealed increased odds of mortality in patients with refractory ascites (odds ratio [OR], 4.34; 95% confidence interval [CI], 1.00, 18.88; P = 0.05) and growth failure (OR, 13.49; 95% CI, 3.07, 58.99; P < 0.01). Conclusion: In this single institution study, patients with prehepatic pHTN had better survival and those who received no intervention had higher mortality than those who received an intervention. Early referral to specialized centers with experience managing these complex disease processes may allow for improved risk stratification and early intervention to improve outcomes.
Environmental distribution, transport and ecotoxicity of microplastics: A review
Authors: Du Jia , Zhou Qingwei , Li Huanxuan , Xu Shaodan , Wang Chunhui , Fu Li , Tang Junhong 
Published: July 2020

AbstractMicroplastics (MPs) have become a global environmental pollutant because of their unique properties. The extensive MP toxicity reports have focused on the aquatic environment, while the pervasive MP contamination in the soil and air has largely been overlooked. This review summarizes the abundance, sources and transport of MPs in different environments. It analyzes the toxicity of MPs based on various environmentally relevant bacterial, cellular, plant, aquatic animal and mammalian test groups, using both in vitro and in vivo experiments. The combined toxicity effects of MPs and various other environmental pollutants on ecosystems are also discussed. Currently, data on the adverse effects on combined MP toxicity are very limited. Thus, a systematic assessment of the environmental risk in different environments and in various species from MPs is challenging. Thus, this review proposes the possible risks and identifies the knowledge gaps posed by MPs to food safety and human health.
Development of a new photosafety test method based on singlet oxygen generation detected using electron spin resonance
Authors: Hinoshita Masumi , Abe Takayuki , Sato Asako , Maeda Yosuke , Takeyoshi Masahiro 
Published: July 2020

AbstractPhotosafety evaluations of chemicals used in consumer products, such as pharmaceuticals and cosmetics, are very important. Currently, two non‐animal tests for photosafety evaluations, the in vitro 3T3 neutral red uptake phototoxicity test (NRU PT) and the reactive oxygen species (ROS) assay, are used to detect photoreactive chemicals. However, these two tests are difficult to apply to hydrophobic chemicals. In the present study, we attempted to develop a new photosafety test method, named the electron spin resonance‐based photosafety test (ESR‐PT), that would be applicable even to hydrophobic chemicals based on the detection of singlet oxygen generation after irradiation using ESR spectroscopy with 4‐hydroxy‐2,2,6,6‐tetramethyl‐piperidine as a spin trap reagent. To achieve a quantitative evaluation, the singlet oxygen formation (SOF) value, which can be calculated as the increment in relative intensity after irradiation of the test mixture normalized by the increment in relative intensity after irradiation of the vehicle control solution, was calculated. The performance of the ESR‐PT was evaluated by testing all the proficiency chemicals of the ROS assay plus additional chemicals, including hydrophobic chemicals and chemicals that tested false negative in the 3T3‐NRU PT and ROS assay. SOF values were successfully calculated for all the chemicals tested including the hydrophobic chemicals, and the accuracy of the ESR‐PT using a tentative cutoff value of 2.8 against the photosafety information was 100%. Therefore, the SOF value could be an effective parameter for photosafety evaluations, suggesting that the newly developed ESR‐PT is a promising non‐animal test applicable even to hydrophobic chemicals.