bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wide Bandgap Perovskite Oxides with High Room‐Temperature Electron Mobility
Authors: Prakash Abhinav , Jalan Bharat 
Published: July 2019

AbstractPerovskite oxides are ABO3‐type compounds with a crystal structure capable of accommodating a large number of elements at A‐ and B‐sites. Owing to their flexible structure and complex chemistry, they exhibit a wide range of functionalities as well as novel ground states at the interface. However, in comparison with conventional semiconductors such as silicon, they possess orders of magnitude lower room‐temperature electron mobilities limiting their room‐temperature electronic applications. For example, in a prototypical doped SrTiO3, the room‐temperature electron mobility remains below 10 cm2 V−1 s−1 regardless of the defect minimization. Discovery of high room‐temperature mobility in alkaline‐earth stannates such as BaSnO3 and SrSnO3 constitutes a significant advancement toward all‐perovskite electronic and spintronic devices. Alkaline‐earth stannates also possess wide‐to‐ultra wide bandgaps that make them potentially suitable candidate for transparent conductors, power electronic devices, and high electron mobility transistors. This article provides an overview of the recent progress made to these materials' electrical properties with particular emphasis on the advancements in the molecular beam epitaxy approaches for their synthesis, and defect control.
Metal‐Free Synthesis of 4‐Aryl‐2‐quinolone Derivatives by Iodine‐Mediated Intramolecular C−H Amidation
Authors: Ghosh Subhankar , Chattopadhyay Shital K. 
Published: July 2019

AbstractA metal‐free synthesis of a range of 4‐aryl‐2‐quinolone derivatives has been developed which utilizes an iodine‐mediated intramolecular C−H amidation of 3,3‐diarylacryl amides as the key step. Electron‐withdrawing or ‐donating substituents in either of the aryl rings display marginal influence on the course of the reaction. However, the presence of the diarylalkene moiety has been found to be crucial for the success of the reaction. The reaction proceeds in very good yield and is applicable to a range of substrates. Moreover, the methodology overcomes some of the difficulties associated with metal‐mediated approaches such as regio‐isomeric product formation, and E‐Z isomerization. We propose a mechanism involving the in situ generation of hypoiodous acid as source of positive iodine.magnified image
Photoredox‐Catalyzed Cyclopropanation of 1,1‐Disubstituted Alkenes via Radical‐Polar Crossover Process
Authors: Luo Wenping , Yang Yi , Fang Yewen , Zhang Xinxin , Jin Xiaoping , Zhao Guicai , Zhang Li , Li Yan , Zhou Wanli , Xia Tingting , Chen Bin 
Published: July 2019

AbstractThe photoredox‐neutral catalyzed cyclopropanation of 1,1‐disubstituted alkenes via radical addition‐anionic cyclization cascade has been successfully developed. Another new protocol based on photocatalytic allylation and cyclopropanation cascade was also described between allylic halide and halomethyl radical. In addition to the successful use of bis‐catecholato silicates as the alkyl radical precursors, the acyl and alkyl radicals derived from 1,4‐dihydropyridines were also engaged in this radical‐polar crossover process. The competing experiments displayed that the 3‐exo‐tet mode of cyclization preferred over 4‐exo and 5‐exo cyclization modes, allowing for the selective 3‐exo‐tet cyclization. The superior nucleofuge character of bromide over chloride and tosylate has been demonstrated in the reaction of bromomethyl radical with homoallylic (pseudo)halides. This new protocol is characterized by its redox‐neutral process, broad substrate scope, mild conditions, and good functional‐group compatibility.magnified image
A multistate model for early decision‐making in oncology
Authors: Beyer Ulrich , Dejardin David , Meller Matthias , Rufibach Kaspar , Burger Hans Ulrich 
Published: July 2019

AbstractThe development of oncology drugs progresses through multiple phases, where after each phase, a decision is made about whether to move a molecule forward. Early phase efficacy decisions are often made on the basis of single‐arm studies based on a set of rules to define whether the tumor improves (“responds”), remains stable, or progresses (response evaluation criteria in solid tumors [RECIST]). These decision rules are implicitly assuming some form of surrogacy between tumor response and long‐term endpoints like progression‐free survival (PFS) or overall survival (OS). With the emergence of new therapies, for which the link between RECIST tumor response and long‐term endpoints is either not accessible yet, or the link is weaker than with classical chemotherapies, tumor response‐based rules may not be optimal. In this paper, we explore the use of a multistate model for decision‐making based on single‐arm early phase trials. The multistate model allows to account for more information than the simple RECIST response status, namely, the time to get to response, the duration of response, the PFS time, and time to death. We propose to base the decision on efficacy on the OS hazard ratio (HR) comparing historical control to data from the experimental treatment, with the latter predicted from a multistate model based on early phase data with limited survival follow‐up. Using two case studies, we illustrate feasibility of the estimation of such an OS HR. We argue that, in the presence of limited follow‐up and small sample size, and making realistic assumptions within the multistate model, the OS prediction is acceptable and may lead to better early decisions within the development of a drug.
The added value of fasting blood glucose to serum squamous cell carcinoma antigen for predicting oncological outcomes in cervical cancer patients receiving neoadjuvant chemotherapy followed by radical hysterectomy
Authors: Wu Miao‐Fang , Guan Mei‐Mei , Liu Chang‐Hao , Wu Jie‐Ying , Rao Qun‐Xian , Li Jing 
Published: July 2019

AbstractObjectiveTo determine the combination of fasting blood glucose (FBG) with squamous cell carcinoma antigen (SCCA) assessments in the prediction of tumor responses to chemotherapy and pretreatment prognostication among patients receiving neoadjuvant chemotherapy (NACT) for locally advanced cervical cancer (LACC).MethodsData of 347 LACC patients were retrospectively reviewed. Receiver operating characteristic (ROC) curves were constructed, and areas under the curves (AUCs) were compared to evaluate the ability to predict complete response (CR) following NACT. Patients were stratified into groups with low and high levels of SCCA and FBG and combined into low‐ or high‐SCCA and low‐ or high‐FBG groups. Cox regression analysis was performed to identify determinants of recurrence‐free survival (RFS) and overall survival (OS).ResultsThe AUCs were 0.70, 0.68, and 0.66 for SCCA, FBG, and a combination of SCCA and FBG for predicting CR following NACT, respectively; however, the differences among AUCs were not significant (P = .496). Pretreatment SCCA and FBG levels were identified as independent predictors of RFS and OS. The high‐SCCA/high‐FBG group showed significantly worse prognosis than the low‐SCCA/low‐FBG group. After adjusting for other variables, high‐SCCA/high‐FBG remained independently associated with an increased risk of tumor recurrence and death.ConclusionSCCA, FBG, and a combination of SCCA and FBG could acceptably predict CR following NACT. Pretreatment SCCA and FBG levels were independent prognostic factors. The combination of SCCA and FBG levels refined the prognostic stratification of LACC patients, which allowed the group of patients with the highest risk of recurrence and death to be identified.
Nucleotide Binding Modes in a Motor Protein Revealed by 31P‐ and 1H‐Detected MAS Solid‐State NMR Spectroscopy
Authors: Wiegand Thomas , Schledorn Maarten , Malär Alexander A. , Cadalbert Riccardo , Däpp Alexander , Terradot Laurent , Meier Beat H. , Böckmann Anja 
Published: July 2019

AbstractProtein–nucleic acid interactions play important roles not only in energy‐providing reactions, such as ATP hydrolysis, but also in reading, extending, packaging, or repairing genomes. Although they can often be analyzed in detail with X‐ray crystallography, complementary methods are needed to visualize them in complexes, which are not crystalline. Here, we show how solid‐state NMR spectroscopy can detect and classify protein–nucleic interactions through site‐specific 1H‐ and 31P‐detected spectroscopic methods. The sensitivity of 1H chemical‐shift values on noncovalent interactions involved in these molecular recognition processes is exploited allowing us to probe directly the chemical bonding state, an information, which is not directly accessible from an X‐ray structure. We show that these methods can characterize interactions in easy‐to‐prepare sediments of the 708 kDa dodecameric DnaB helicase in complex with ADP:AlF4−:DNA, and this despite the very challenging size of the complex.
In Situ Measurement of Local pH at Working Electrodes in Neutral pH Solutions by the Rotating Ring‐Disk Electrode Technique
Authors: Yokoyama Yuko , Miyazaki Kohei , Miyahara Yuto , Fukutsuka Tomokazu , Abe Takeshi 
Published: July 2019

AbstractWhen electrochemical reactions that generate/consume protons or hydroxide ions take place, the local pH in the vicinity of an electrode becomes considerably different from the bulk pH. However, measuring the local pH is very difficult, and the idea of using a rotating ring‐disk electrode (RRDE) is not applicable to solutions with neutral pH. Herein, we extend the theory of local pH measurement using a RRDE and make it applicable to solutions with a wide pH range. This extended theory is corroborated by measurements of hydrogen oxidation/evolution reactions in solutions with near‐neutral pH. In addition, the local pH change in a highly concentrated solution is also measured, and the results show that this local pH measurement method can be used regardless of the solution concentration.
Demonstrating a Metal‐Metal Battery System in Aprotic Electrolyte with Silver and Lithium
Authors: Wang Huimin , Gu Wenchuan , Yu Denis Y. W. 
Published: July 2019

AbstractMetals are attractive materials for energy storage as they can undergo oxidation to accommodate charge transfer. However, traditional metal‐metal batteries such as Cu−Zn have low voltage because of the use of an aqueous electrolyte. Here, we propose a metal‐metal battery system with higher voltage in aprotic electrolyte with Ag/AgCl and Li/Li+ reactions on the cathode and anode, respectively. The Ag−Li cell gives a voltage of about 2.8 V and a capacity of close to 200 mAh g−1. X‐ray diffraction confirms the formation of AgCl during charging. The reduction of AgCl is faster than oxidation of Ag, so the battery has better discharge rate performance than charge. We also find that the solubility of the charge product (AgCl) in the electrolyte influences the cycle stability of the battery.
19F NMR Monitoring of Reversible Protein Post‐Translational Modifications: Class D β‐Lactamase Carbamylation and Inhibition
Authors: van Groesen Emma , Lohans Christopher T. , Brem Jürgen , Aertker Kristina M. J. , Claridge Timothy D. W. , Schofield Christopher J. 
Published: July 2019

AbstractBacterial production of β‐lactamases with carbapenemase activity is a global health threat. The active sites of class D carbapenemases such as OXA‐48, which is of major clinical importance, uniquely contain a carbamylated lysine residue which is essential for catalysis. Although there is significant interest in characterizing this post‐translational modification, and it is a promising inhibition target, protein carbamylation is challenging to monitor in solution. We report the use of 19F NMR spectroscopy to monitor the carbamylation state of 19F‐labelled OXA‐48. This method was used to investigate the interactions of OXA‐48 with clinically used serine β‐lactamase inhibitors, including avibactam and vaborbactam. Crystallographic studies on 19F‐labelled OXA‐48 provide a structural rationale for the sensitivity of the 19F label to active site interactions. The overall results demonstrate the use of 19F NMR to monitor reversible covalent post‐translational modifications.
Biliary reflux as a causal factor in hypopharyngeal carcinoma: New clinical evidence and implications
Authors: Sasaki Clarence T. , Doukas Sotirios G. , Costa Jose , Vageli Dimitra P. 
Published: July 2019

BackgroundRecent preclinical explorations strongly support the tumorigenic potential of bile on laryngopharyngeal mucosa. Herein, the authors describe, in bile‐related human hypopharyngeal squamous cell carcinoma (HSCC), NF‐κB–related messenger RNA (mRNA) and microRNA (miRNA) oncogenic phenotypes similar to those previously identified in acidic bile–exposed premalignant murine hypopharyngeal mucosa.MethodsIn this pilot study, the authors included human HSCC specimens paired with their adjacent normal tissue (ANT) derived from 3 representative patients with documented biliary laryngopharyngeal reflux (bile[+]) compared with 5 control patients without signs of bile reflux disease (bile[‐]). Immunohistochemical, quantitative polymerase chain reaction, and miRNA analyses were used to detect the levels of activated NF‐κB and expression levels of STAT3, EGFR, BCL2, WNT5A, IL‐6, IL‐1B, ΔNp63, cREL, TNF‐α, TP53, NOTCH1, NOTCH2, NOTCH3, miR‐21, miR‐155, miR‐192, miR‐34a, miR‐375, miR‐451a, miR‐489, miR‐504, and miR‐99a.ResultsBile(+) HSCC demonstrated an intense NF‐κB activation accompanied by significant overexpression of RELA(p65), EGFR, STAT3, BCL‐2, cREL, ΔNp63, WNT5A, IL‐6, and IL1B; upregulation of oncomir miR‐21; and downregulation of tumor suppressor miR‐375 compared with their respective ANTs. Bile(+) HSCC demonstrated significantly higher mRNA levels of all the analyzed genes, particularly RELA(p65), IL‐6, EGFR, and TNF‐α compared with bile(‐) tumors. The miR‐21/miR‐375 ratio, which previously has been linked to tumor aggressiveness, was found to be >260‐fold and >30‐fold higher, respectively, in bile(+) HSCCs compared with their ANTs and bile(‐) tumors.ConclusionsAlthough limitations apply to this pilot study due to the small number of patients with HSCC, the novel findings suggest that a history of bile as a component of esophageal reflux disease may represent an independent risk factor for hypopharyngeal carcinogenesis.
Visual short‐term memory activation patterns in adult survivors of childhood acute lymphoblastic leukemia
Authors: Boulet‐Craig Aubree , Robaey Philippe , Barlaam Fanny , Laniel Julie , Oswald Victor , Jerbi Karim , Sultan Serge , Affret‐Bertout Laurence , Drouin Simon , Krajinovic Maja , Laverdière Caroline , Sinnett Daniel , Jolicoeur Pierre , Lippé Sarah 
Published: July 2019

BackgroundAcute lymphoblastic leukemia (ALL) is the most common childhood cancer. Treatments against ALL might lead to later cognitive effects and alterations in brain structure in survivors but to the authors' knowledge the observed variability in the severity of neurocognitive deficits is not fully understood. The objective of the current study was to investigate abnormalities in visual short‐term memory (VSTM) brain activation in survivors of childhood ALL using magnetoencephalography.MethodsA VSTM task was completed by 40 survivors of ALL and 26 controls. VSTM capacity (Cowan K) and brain activation were assessed during the retention period of the task (400‐1400 milliseconds) using a standard minimum norm source localization method.ResultsPerformance (Cowan K) was found to be similar between survivors of ALL and controls. Atypical brain activation was found in survivors of ALL during the task, including overactivation of regions usually involved in VSTM (lateral occipital, precentral gyrus, and postcentral gyrus), recruitment of regions that typically are not involved in VSTM (superior/middle temporal gyrus and supramarginal gyrus), and lower activation of frontal brain regions (inferior frontal gyrus). These patterns of activation were modulated by the age at the time of cancer onset (P = .01) because activity was found to be reduced in participants who were younger at diagnosis.ConclusionsThe results of the current study suggest a pattern of neural inefficiency and compensatory activity during VSTM in survivors of ALL.
Magnesium‐Based Clusters as Building Blocks of Electrolytes in Lithium‐Ion Batteries
Authors: Sikorska Celina 
Published: July 2019

AbstractSuperhalogens, owing to their large electron affinity (EA, exceeding those of any halogen atom), play an essential role in physical chemistry as well as new material design. They have applications in hydrogen storage and lithium‐ion batteries. Owing to the unique geometries and electronic features of magnesium‐based clusters, their potential to form a new class of lithium salts has been investigated here theoretically. The idea is assessed by conducting ab initio computations on Li+/MgnF2n+1‐2mOm− compounds (n=2, 3; m=0‐3) and analyzing their performance as potential Li‐ion battery electrolytes. The Mg3F7− cluster, with large electron binding energy (EA of 7.93 eV), has been proven to serve as a building block for lithium salts. It is shown that, apart from high electronic stability, the new superhalogen‐based electrolytes exhibit a set of desirable properties, including a large band gap, high electrolyte stability window, easy mobility of the Li+, and favorable insensitivity to water.
Hydroxylamine Oxidation on Polycrystalline Gold Electrodes in Aqueous Electrolytes: Quantitative On‐Line Mass Spectrometry under Forced Convection
Authors: Pozniak Boguslaw , Treufeld Imre , Scherson Daniel 
Published: July 2019

AbstractHerein, a method is presented that allows quantitative determination of faradaic efficiencies for dinitrogen (N2) generation during the electrochemical oxidation of hydroxylamine (NH2OH),
, on a polycrystalline gold Au(poly) disk electrode in aqueous electrolytes over a wide pH range. This tactic involves the use of an impinging jet electrolyte configuration incorporating a gas porous ring connected in turn to a mass spectrometer. The actual amount of N2 generated at the Au(poly) disk was assayed using the oxidation of hydrazine (N2H4) in aqueous phosphate buffer (pH 7). This redox process yields N2 as the only product, allowing a direct correlation to be established between the changes in the partial pressures of N2 and the current flowing through the disk electrode. An analysis of the data collected revealed a strong dependence of
both on pH and the applied potential. Although values of
as high as 20 to 30 % were found in acid and neutral media over a narrow potential region, those in alkaline solution were far smaller in the entire potential range examined.
Synthesis of Poly(ADP‐ribose) Monomer Containing 2′‐O‐α‐D‐Ribofuranosyl Adenosine
Authors: Mikhailov Sergey N. , Drenichev Mikhail S. , Oslovsky Vladimir E. , Kulikova Irina V. , Herdewijn Piet 
Published: July 2019

AbstractIn this article, the earlier reported procedure for the synthesis of 2′‐O‐β‐D‐ribofuranosyl nucleosides was extended to the synthesis of 2′‐O‐α‐D‐ribofuranosyl adenosine, a monomeric unit of poly(ADP‐ribose). It consists in condensation of a small excess of 1‐O‐acetyl‐2,3,5‐tri‐O‐benzoyl‐α,β‐D‐arabinofuranose activated with tin tetrachloride with 3′,5′‐O‐tetra‐isopropyldisiloxane‐1,3‐diyl‐ribonucleosides in 1,2‐dichloroethane. The following debenzoylation and silylation of arabinofuranosyl residue and inversion of configuration at C‐2ʹʹ atom of arabinofuranosyl residue and final removal of silyl protective groups gave 2′‐O‐α‐D‐ribofuranosyl adenosine in overall 13% to 21% yield. © 2019 by John Wiley & Sons, Inc.
Local parasite pressures and host genotype modulate epigenetic diversity in a mixed‐mating fish
Authors: Berbel‐Filho Waldir M. , Garcia de Leaniz Carlos , Morán Paloma , Cable Joanne , Lima Sergio M. Q. , Consuegra Sofia 
Published: July 2019

AbstractParasite‐mediated selection is one of the main drivers of genetic variation in natural populations. The persistence of long‐term self‐fertilization, however, challenges the notion that low genetic variation and inbreeding compromise the host's ability to respond to pathogens. DNA methylation represents a potential mechanism for generating additional adaptive variation under low genetic diversity. We compared genetic diversity (microsatellites and AFLPs), variation in DNA methylation (MS‐AFLPs), and parasite loads in three populations of Kryptolebias hermaphroditus, a predomintanly self‐fertilizing fish, to analyze the potential adaptive value of DNA methylation in relation to genetic diversity and parasite loads. We found strong genetic population structuring, as well as differences in parasite loads and methylation levels among sampling sites and selfing lineages. Globally, the interaction between parasites and inbreeding with selfing lineages influenced DNA methylation, but parasites seemed more important in determining methylation levels at the local scale.
Interaction of seed dispersal and environmental filtering affects woody encroachment patterns in coastal grassland
Authors: Woods Natasha N. , Dows Benjamin L. , Goldstein Evan B. , Moore Laura J. , Young Donald R. , Zinnert Julie C. 
Published: July 2019

AbstractEncroachment of woody plants into grasslands has occurred worldwide and includes coastal ecosystems. This conversion process is mediated by seed dispersal patterns, environmental filtering, and biotic interactions. As spatiotemporally heterogeneous, harsh environments, barrier islands present a unique set of challenges for dispersal and establishment. Environmental conditions act as filters on dispersed seeds, thereby influencing encroachment and distribution patterns. Seldom have patterns of propagule dispersal been considered in the context of woody encroachment. We quantified dispersal and post‐dispersal processes of an encroaching woody population of Morella cerifera relative to directional rate of encroachment and observed distribution patterns on an Atlantic coastal barrier island with strong environmental filtering. We analyzed historic foredune elevation as a proxy for reduced interior environmental stress. The dispersal kernel was leptokurtic, a common characteristic of expanding populations, but rate of encroachment has slowed since 2005. Expansion pattern was related to foredune elevation, which limits encroachment below a threshold elevation. This difference between dispersal kernel behavior and encroachment rate is due to limited availability of suitable habitat for Morella and temporal variability in chlorides during the time of germination. Our results demonstrate that processes mediating seeds and seedling success must be accounted for to better understand establishment patterns of encroaching woody plants.