bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kooperative Zusammenarbeit von N‐heterocyclischen Carbenen auf einer Goldoberfläche
Authors: Amirjalayer Saeed , Bakker Anne , Freitag Matthias , Glorius Frank , Fuchs Harald 
Published: August 2020

AbstractDie atomar präzise Gestaltung von Grenzflächenstrukturen ist für die Entwicklung funktioneller Materialien von entscheidender Bedeutung. Wir demonstrieren ein molekulares Werkzeug auf der Basis von N‐heterocyclischen Carbenen (NHCs), welches die Struktur einer Goldoberfläche mit atomarer Genauigkeit durch die Bildung von Gold‐Nanostrukturen modifiziert. Nach der Adsorption auf der Goldoberfläche werden einzelne Oberflächenatome durch die NHCs herausgezogen, wodurch neben Einzelatom‐Defekten auf der Oberfläche mobile NHC‐Au‐Spezies entstehen. Berechnungen zeigen, dass diese molekularen “Ballbots” als Werkzeuge dienen können, um einzelne Oberflächenatome zu versetzen. Diese vorhergesagte Funktionalität wird durch Rastertunnelmikroskopie bestätigt. Die kooperative Zusammenarbeit der NHC‐Au‐Spezies induziert eine schrittweise Bildung von Gold‐Nanostäbchen. Infolgedessen wird die Oberfläche durch einen reißverschlussartigen Mechanismus neu strukturiert. Die Arbeit bildet somit eine Grundlage für den Einsatz Molekül‐basierter Nanowerkzeuge zur gezielten Entwicklung von Oberflächenstrukturen dar.
MWCNTs reinforced conductive, self‐healing polyvinyl alcohol/carboxymethyl chitosan/oxidized sodium alginate hydrogel as the strain sensor
Authors: Wu Lu , Li Longwei , Pan Lujun , Wang Hai , Bin Yuezhen 
Published: August 2020

AbstractThe preparation and application of hydrogel has been a hot research field in recent years. Here in, a composite hydrogel based on poly(vinyl alcohol) (PVA), carboxymethyl chitosan (CMCS), oxidized sodium alginate (OSA), and oxidized multiwall carbon nanotubes (OMWCNTs) was successfully prepared. Hydrogen and imine bonds of the hydrogel endowed the composite hydrogel with self‐healing property and pH sensitivity. The fracture strength of the hydrogel was enhanced to about 0.8 MPa with the help of OMWCNTs, which was about 2.5 times compared with the one without OMWCNTs. Meanwhile, a new conductive network inside the hydrogel was constructed by OMWCNTs, which improved the conductivity of the hydrogel from 1.75 × 10−4 to 7.02 × 10−4 S/cm. The sensing test of the hydrogel showed that it could produce profound feedback signals for the deformation caused by external force and response to human body movements, such as finger bending, swallowing, and speaking.
Improved chemical stability and proton selectivity of semi‐interpenetrating polymer network amphoteric membrane for vanadium redox flow battery application
Authors: Yu Hailin , Xia Yifan , Zhang Hanwen , Gong Xinjian , Geng Pengfei , Gao Zhenwei , Wang Yinghan 
Published: August 2020

AbstractIn this work, semiinterpenetrating polymer network (semi‐IPN), consisting of sulfonated poly (arylene ether sulfone) (SPAES) and crosslinked vinyl imidazole grafted polysulfone (VMPSU), is prepared and characterized. FTIR, EDS, and solubility test indicate the successful preparation of amphoteric membranes. The semi‐IPN amphoteric membranes exhibit better stability than pure SPAES membrane, as demonstrated by thermogravimetric analysis and ex situ immersion testing results. More importantly, it is shown that the amphoteric membrane can effectively hinder vanadium ion crossover through the membrane, which is attributed to the semi‐IPN structure and Donnan exclusion. As expected, the amphoteric membrane containing 20% VMPSU exhibits the highest proton selectivity (6.86 × 104 S min cm−3), comparing to pristine SPAES (1.90 × 104 S min cm−3) as well as Nafion117 (1.31 × 104 S min cm−3).
Chiral Transient Directing Group Strategies in Asymmetric Synthesis
Authors: Bag Debojyoti , Verma Praveen Kumar , Sawant Sanghapal D. 
Published: August 2020

AbstractThe development of novel methodologies for catalytic enantioselective functionalization reactions enabled by chiral transient directing groups is accompanying in a paradigm shift in the field of asymmetric synthesis. In particular, these highly atom‐ and step‐economic enantioinduction processes commonly proceed either via enantioselective C−H functionalization, or via enantioselective hydroarylation of the pro‐chiral substrates generating point, axial or planar chirality. The use of the transient directing group strategy in C−H functionalizations precludes the stoichiometric installations and removal of directing groups and enables efficient, more compatible and economical chemical routes. This minireview highlights asymmetric transition‐metal‐catalyzed methodologies involving chiral transient directing groups together with the scope, utility and future perspective of the field.
Sensitive identification of prostate‐specific antigen by iron oxide nanoparticle antibody conjugates on the gap‐finger electrode surface
Authors: Zhang Wei , Li Kai , Guo Jingyang , Ma Tao , Wang Dongqing , Shi Sumei , Gopinath Subash C. B. , Gu Deqiang 
Published: August 2020

AbstractResearches have proved that increasing level of prostate‐specific antigen (PSA) is an indicator for the progression of prostate cancer. The present study was focused to determine the PSA level by using anti‐PSA antibody conjugated iron oxide nanoparticles, as the probe immobilized on the gap‐fingered electrode sensing surface. The detection limit and sensitivity were found at the level of 1.9 pg/mL on the linear regression curve (y = 1.6939x − 0.5671; R² = 0.9878). A dose‐dependent liner range was found from 1.9 until 60 pg/mL. Further, PSA was spiked in human serum and did not affect the interaction of PSA and its antibody. This method of detection quantifies the level of PSA, which helps to diagnose prostate cancer at its earlier stage.
Enhanced Safety Performance of Automotive Lithium‐Ion Batteries with Al2O3‐Coated Non‐Woven Separator
Authors: Meng Fanhui , Gao Jinhui , Zhang Mengdi , Li Dongwei , Liu Xizheng 
Published: August 2020

AbstractThermal runaway (TR) is the fatal safety defects that hinder the wide application of automotive batteries. The short circuit caused by shrinkage of separators under high temperatures leads to TR. In this paper, we demonstrate the robust thermal stability of an Al2O3 coated non‐woven polyethylene terephthalate (PET) separator. The shrinkage ratio of the Al2O3 coated separator has been compared with the non‐coated polyethylene (PE) separator by differential scanning calorimetry (DSC), thermogravimetry (TG ) and heat nail tests. Automotive lithium‐ion batteries (LIBs) with large capacities have been used to conduct the simulations of nail penetration. TR is found to be triggered by Joule heat generation during the shrinkage of the separators. The separator with lower shrinkage retains highly stable dimension against wide range temperature changes. This feature enables the Al2O3 coated separator to prevent inner short circuits. The improved safety performance indicates a promising prospect of Al2O3 coated non‐woven separators in LIBs.
Evolution of Sex Determination in Amniotes: Did Stress and Sequential Hermaphroditism Produce Environmental Determination?
Authors: Straková Barbora , Rovatsos Michail , Kubička Lukáš , Kratochvíl Lukáš 
Published: August 2020

AbstractFrequent independent origins of environmental sex determination (ESD) are assumed within amniotes. However, the phylogenetic distribution of sex‐determining modes suggests that ESD is likely very ancient and may be homologous across ESD groups. Sex chromosomes are demonstrated to be old and stable in endothermic (mammals and birds) and many ectothermic (non‐avian reptiles) lineages, but they are mostly non‐homologous between individual amniote lineages. The phylogenetic pattern may be explained by ancestral ESD with multiple transitions to later evolutionary stable genotypic sex determination. It is pointed out here that amniote ESD shares several key aspects with sequential hermaphroditism of fishes such as a lack of sex differences in genomes, biased population sex ratios, and potentially also molecular mechanism related to general stress responses. Here, it is speculated that ESD evolves via a heterochronic shift of the sensitive period of sex change from the adult to the embryonic stage in a hermaphroditic amniote ancestor. Also see the video abstract here https://youtu.be/q2mjtlCefu4.
Targeting lactate dehydrogenase A (LDHA) exerts antileukemic effects on T‐cell acute lymphoblastic leukemia
Authors: Yu Haizhi , Yin Yafei , Yi Yifang , Cheng Zhao , Kuang Wenyong , Li Ruijuan , Zhong Haiying , Cui Yajuan , Yuan Lingli , Gong Fanjie , Wang Zhihua , Li Heng , Peng Hongling , Zhang Guangsen 
Published: August 2020

AbstractBackgroundT‐cell acute lymphoblastic leukemia (T‐ALL) is an uncommon and aggressive subtype of acute lymphoblastic leukemia (ALL). In the serum of T‐ALL patients, the activity of lactate dehydrogenase A (LDHA) is increased. We proposed that targeting LDHA may be a potential strategy to improve T‐ALL outcomes. The current study was conducted to investigate the antileukemic effect of LDHA gene‐targeting treatment on T‐ALL and the underlying molecular mechanism.MethodsPrimary T‐ALL cell lines Jurkat and DU528 were treated with the LDH inhibitor oxamate. MTT, colony formation, apoptosis, and cell cycle assays were performed to investigate the effects of oxamate on T‐ALL cells. Quantitative real‐time PCR (qPCR) and Western blotting analyses were applied to determine the related signaling pathways. A mitochondrial reactive oxygen species (ROS) assay was performed to evaluate ROS production after T‐ALL cells were treated with oxamate. A T‐ALL transgenic zebrafish model with LDHA gene knockdown was established using CRISPR/Cas9 gene‐editing technology, and then TUNEL, Western blotting, and T‐ALL tumor progression analyses were conducted to investigate the effects of LDHA gene knockdown on T‐ALL transgenic zebrafish.ResultsOxamate significantly inhibited proliferation and induced apoptosis of Jurkat and DU528 cells. It also arrested Jurkat and DU528 cells in G0/G1 phase and stimulated ROS production (all P < 0.001). Blocking LDHA significantly decreased the gene and protein expression of c‐Myc, as well as the levels of phosphorylated serine/threonine kinase (AKT) and glycogen synthase kinase 3 beta (GSK‐3β) in the phosphatidylinositol 3′‐kinase (PI3K) signaling pathway. LDHA gene knockdown delayed disease progression and down‐regulated c‐Myc mRNA and protein expression in T‐ALL transgenic zebrafish.ConclusionTargeting LDHA exerted an antileukemic effect on T‐ALL, representing a potential strategy for T‐ALL treatment.
Streptococcus sanguisbrain abscess as an initial manifestation of pulmonary arteriovenous malformation
Authors: Chang Chee Yik , Chai Cindy Syn Ying , Ong Edmund L. C. 
Published: August 2020

AbstractPulmonary arteriovenous malformation is a vascular anomaly that predisposes to complications of paradoxical embolization including stroke and brain abscess. Here, we present a case of brain abscess associated with pulmonary arteriovenous malformation.
Systematic Catalyst Screening of Zeolites with Various Frameworks and Si/Al Ratios to Identify Optimum Acid Strength in OME Synthesis
Authors: Fink Anja , Gierlich Christian Henning , Delidovich Irina , Palkovits Regina 
Published: August 2020

AbstractOxymethylene dimethyl ethers (OMEx oligomers with the chain length x) present a promising emission reducing diesel additive, which can potentially be produced based on renewable resources. In this work, the OMEx synthesis catalysed by zeolites was investigated starting from paraformaldehyde and methanol. The catalytic performance of zeolites with different framework types (BEA, FAU, MFI, MOR) and various Si/Al ratios was comparatively studied. The zeolites were characterised by means of NH3‐TPD, ICP‐OES, XRD and N2 physisorption. A relationship between catalytic activity and Si/Al ratio was established demonstrating the highest turnover frequency for zeolites with high Si/Al ratios. HZSM‐5 114 with a TOF of 3375 molOME3–5 molAcidSites−1 h−1 was determined as the best‐performing zeolite which indicates that the OMEx synthesis requires a moderately strong acid strength.
A flexible bis‐Co(III) porphyrin cage as a bimetallic catalyst for the conversion of CO2 and epoxides into cyclic carbonates
Authors: Schoepff Laetitia , Monnereau Laure , Durot Stéphanie , Jenni Sébastien , Gourlaouen Christophe , Heitz Valérie 
Published: August 2020

AbstractA molecular cage consisting of two free‐base porphyrins connected by four flexible linkers was metalated with Co(III) to afford in good yield a bimetallic catalyst. The catalytic activity of the bis‐Co(III) porphyrin molecular cage (CoCl)2‐1 was studied for the formation of cyclic carbonates from CO2 and propylene oxide (PO) or styrene oxide (SO) with pyridine as cocatalyst. Various reaction parameters such as the molar ratio of the catalyst and the co‐catalyst, the time of reaction, the temperature and CO2 pressure were investigated. The molecular cage was shown to be a catalyst of high selectivity for the studied reactions and much more efficient to convert the epoxides to the corresponding cyclic carbonates than the monomeric Co(III)Cl meso‐tetraphenylporphyrin (CoCl‐TPP) model. When quantitative conversion of PO into propylene carbonate (PC) was reached (0.1 mol% catalyst, 1.2 mol% pyridine, 120 °C, 30 bar of CO2) only 23 % of PC was obtained with CoCl‐TPP (0.2 mol%). This enhanced catalytic activity is attributed to the synergistic effect of the two metal sites incorporated in the framework of the molecular cage.
Principles and Applications of Miniaturized Near‐Infrared (NIR) Spectrometers
Authors: Beć Krzysztof B. , Grabska Justyna , Huck Christian W. 
Published: August 2020

AbstractThis review article focuses on the principles and applications of miniaturized near‐infrared (NIR) spectrometers. This technology and its applicability has advanced considerably over the last few years and revolutionized several fields of application. What is particularly remarkable is that the applications have a distinctly diverse nature, ranging from agriculture and the food sector, through to materials science, industry and environmental studies. Unlike a rather uniform design of a mature benchtop FTNIR spectrometer, miniaturized instruments employ diverse technological solutions, which have an impact on their operational characteristics. Continuous progress leads to new instruments appearing on the market. The current focus in analytical NIR spectroscopy is on the evaluation of the devices and associated methods, and to systematic characterization of their performance profiles.
Natural Products Originated from the Oxidative Coupling of Tyrosine and Tryptophan: Biosynthesis and Bioinspired Synthesis
Authors: Tang Shanyu , Vincent Guillaume 
Published: August 2020

AbstractThe oxidative coupling of tyrosine and tryptophan units is a pivotal step in the total synthesis of some peptide‐derived marine and terrestrial natural products, such as the diazonamides, azonazine and tryptorubin A. This Minireview details the biosynthesis and bioinspired synthesis of natural products with such structures. A special focus is put on the challenges of the synthesis of these natural products and the innovative solutions adopted by synthetic chemists.
Photophysical Properties and Heterogeneous Photoredox Catalytic Activities of Ru(bpy)3@InBTB Metal–Organic Framework (MOF)
Authors: Choi In‐Hwan , Yoon Sukbin , Huh Seong , Kim Sung‐Jin , Kim Youngmee 
Published: August 2020

AbstractMetal–organic frameworks (MOFs) with negatively charged frameworks are suitable for selectively encapsulating cationic guest ions via a cation‐exchange process. Encapsulating photoactive [RuL3]2+ polypyridine complexes into the preorganized mesoscale channels of a MOF is a good method for stabilizing the excited states of the complexes. Three new RuL3@InBTB MOFs were prepared by encapsulating cationic [Ru(bpy)3]2+ (bpy=2,2′‐bipyridine), [Ru(phen)3]2+ (phen=1,10‐phenanthroline), and [Ru(bpz)3]2+ (bpz=2,2′‐bipyrazine) into the mesopores of a three‐dimensional (3D) InBTB MOF (H3BTB=1,3,5‐benzenetribenzoic acid). The photophysical properties of the resulting materials were investigated by photoluminescence (PL) analysis. The photoredox catalytic activities were also investigated for the aza‐Henry reaction, hydrogenation of dimethyl maleate, and decomposition of methyl orange under visible light irradiation at room temperature. RuL3@InBTB MOFs were found to be very stable and highly recyclable photoredox catalytic systems.
Runtime power allocation approach for GAMESS hybrid CPU‐GPU implementation
Authors: Sundriyal Vaibhav , Sosonkina Masha , Poole David , Gordon Mark S. 
Published: August 2020

SummaryTo improve power consumption of applications at the runtime, modern processors provide frequency scaling capabilities, which along with workload optimization, are also available on GPU accelerators. In this work, a runtime strategy is proposed to distribute a given power allocation among the host components and the GPU according to the current application performance and power usage, such that GPU execution is prioritized over CPU for power allocation to maximize application performance. Next, the strategy is tailored to an application, a quantum‐chemistry package GAMESS for ab initio electronic structure calculations. Specifically, GAMESS hybrid CPU–GPU implementation as provided in the Libcchem library is considered. Experiments, performed on a 28‐core node with a Kepler GPU, resulted in performance gains of up to 50% under the proposed strategy and the largest power allocation considered here as compared with the scenario when this allocation was equally distributed among the computing‐platform components.
Probing the Roughness of Porphyrin Thin Films with X‐ray Photoelectron Spectroscopy
Authors: Kataev Elmar , Wechsler Daniel , Williams Federico J. , Köbl Julia , Tsud Natalia , Franchi Stefano , Steinrück Hans‐Peter , Lytken Ole 
Published: August 2020

AbstractThin‐film growth of molecular systems is of interest for many applications, such as for instance organic electronics. In this study, we demonstrate how X‐ray photoelectron spectroscopy (XPS) can be used to study the growth behavior of such molecular systems. In XPS, coverages are often calculated assuming a uniform thickness across a surface. This results in an error for rough films, and the magnitude of this error depends on the kinetic energy of the photoelectrons analyzed. We have used this kinetic‐energy dependency to estimate the roughnesses of thin porphyrin films grown on rutile TiO2(110). We used two different molecules: cobalt (II) monocarboxyphenyl‐10,15,20‐triphenylporphyrin (CoMCTPP), with carboxylic‐acid anchor groups, and cobalt (II) tetraphenylporphyrin (CoTPP), without anchor groups. We find CoMCTPP to grow as rough films at room temperature across the studied coverage range, whereas for CoTPP the first two layers remain smooth and even; depositing additional CoTPP results in rough films. Although, XPS is not a common technique for measuring roughness, it is fast and provides information of both roughness and thickness in one measurement.
Advances in Antiviral Material Development
Authors: Liang Lili , Ahamed Ashiq , Ge Liya , Fu Xiaoxu , Lisak Grzegorz 
Published: August 2020

AbstractThe rise in human pandemics demands prudent approaches in antiviral material development for disease prevention and treatment by effective protective equipment and therapeutic strategies. However, the current state of the antiviral materials research is predominantly aligned towards drug development and its related areas, catering to the field of pharmaceutical technology. This Review distinguishes the research advances in terms of innovative materials exhibiting antiviral activities that take advantage of fast‐developing nanotechnology and biopolymer technology. Essential concepts of antiviral principles and underlying mechanisms are illustrated, followed by detailed descriptions of novel antiviral materials including inorganic nanomaterials, organic nanomaterials, and biopolymers. The biomedical applications of the antiviral materials are also elaborated based on the specific categorization. Challenges and future prospects are discussed to facilitate the research and development of protective solutions and curative treatments.
Di(benzothienyl)cyclobutenes: Toward Strained Photoswitchable Fluorophores
Authors: Sysoiev Dmytro , Procházková Eliška , Semenenko Aleksander , Pohl Radek , Shishkina Svitlana , Klepetářová Blanka , Shvadchak Volodymyr , Yushchenko Dmytro A. 
Published: August 2020

AbstractBis(benzothienyl)ethene sulfones are very interesting molecules for super‐resolution microscopy due to their photoswitching properties. However, functionalization of the ‘classical’ bis(benzothienyl)ethene sulfones with a five‐membered central ring leads to significant decrease of quantum yields of photoconversion of the fluorescent closed form of the dye to the non‐fluorescent open form that limits their application in microscopy. Here, we designed and synthesized diarylethenes with a fluorinated four‐membered central ring that adds extra strain to the closed form of the dye. The reaction mechanism of their formation was studied, and byproducts formed upon structural rearrangement of the benzothiophene fragment were characterized. The photochromic properties of the new molecules were investigated by NMR and absorption spectroscopy. Some of these compounds show enhanced tendency to ring opening and have quantum yields of the ring‐opening reaction in the range of 0.2–0.5.
Differentiating the symptoms of posttraumatic stress disorder and bipolar disorders in adults: Utilizing a trauma‐informed assessment approach
Authors: Cogan Chelsea M. , Paquet Caitlin B. , Lee Jenny Y. , Miller Katherine E. , Crowley Matthew D. , Davis Joanne L. 
Published: August 2020

AbstractIn adult populations, bipolar disorders (BDs) and posttraumatic stress disorder (PTSD) have overlapping symptoms, potentially leading to misdiagnosis. This misdiagnosis or failure to diagnose both co‐occurring disorders can result in individuals not receiving the proper treatment to address their symptoms. This article highlights how trauma‐informed psychological assessment can assist in differential diagnosis and improve the timely delivery of appropriate treatments. The overlapping symptoms of PTSD and BD are discussed to assist in differential diagnosis, and we suggest guidelines for conducting trauma‐informed, evidence‐based assessments to help clarify these diagnoses.
Fibre Optic Sensor for Characterisation of Lithium‐Ion Batteries
Authors: Hedman Jonas , Nilebo David , Larsson Langhammer Elin , Björefors Fredrik 
Published: August 2020

AbstractThe interaction between a fibre optic evanescent wave sensor and the positive electrode material, lithium iron phosphate, in a battery cell is presented. The optical–electrochemical combination was investigated in a reflection‐based and a transmission‐based configuration, both leading to comparable results. Both constant current cycling and cyclic voltammetry were employed to link the optical response to the charge and discharge of the battery cells, and the results demonstrated that the optical signal changed consistently with lithium ion insertion and extraction. More precisely, cyclic voltammetry showed that the intensity increased when iron was oxidised during charge and then decreased as iron was reduced during discharge. Cyclic voltammetry also revealed that the optical signal remained unchanged when essentially no oxidation or reduction of the electrode material took place. This shows that optical fibre sensors may be used as a way of monitoring state of charge and electrode properties under dynamic conditions.