bluuebunny/crossref_metadata_2025_split huggingface dataset:
TEMPO‐Modified Polymethacrylates as Mediators in Electrosynthesis – Redox Behavior and Electrocatalytic Activity toward Alcohol Substrates
Authors: Mohebbati Nayereh , Prudlik Adrian , Scherkus Anton , Gudkova Aija , Francke Robert 
Published: June 2021

AbstractHomogeneous catalysts (“mediators”) are useful for tuning selectivity in organic electrosynthesis. However, they can have a negative impact on the overall mass and energy balance if used only once or recycled inefficiently. In a previous work, we introduced the polymediator concept, in which soluble redox‐active polymers catalyze the electrochemical reaction, allowing for recovery by dialysis or pressure‐driven membrane filtration. Using anodic alcohol oxidation as a test case, it was shown that TEMPO‐modified polymethacrylates (TPMA) can serve as efficient and reusable mediators. In the present study, the properties of a TPMA sample with well‐defined molecular weight distribution were studied using cyclic voltammetry and compared to low‐molecular TEMPO species. The non‐catalytic profiles of TPMA are shaped by diffusive and adsorptive processes, whereby the latter only become pronounced at low mediator concentrations and high scan rates. Electrocatalytic studies suggest that under the applied conditions, TPMA‐catalyzed alcohol oxidation is a predominantly homogeneous process. The homogeneous kinetics are determined rather by the mediator potential than by steric influences of the polymer backbone.
Modulating the Enantiodiscrimination Features of Inherently Chiral Selectors by Molecular Design: A HPLC and Voltammetry Study Case with Atropisomeric 2,2’‐Biindole‐Based Monomers and Oligomer Films
Authors: Scapinello Luca , Grecchi Sara , Rossi Sergio , Arduini Fabiana , Arnaboldi Serena , Penoni Andrea , Cirilli Roberto , Romana Mussini Patrizia , Benincori Tiziana 
Published: June 2021

AbstractA family of inherently chiral electroactive selectors based on the 2,2’‐biindole atropisomeric scaffold, of easy synthesis and modulable functional properties, is studied in cascade in two enantioselection contexts. They are at first investigated as probes in enantioselective HPLC, studying molecular structure and temperature effects, and achieving very efficient semipreparative enantioseparation. The enantiomers thus obtained, of remarkable chiroptical features (optical rotation as well as circular dichroism), are successfully applied as selectors in chiral voltammetry in different media for discrimination of the enantiomers of chiral electroactive probes, either by conversion into enantiopure electroactive electrode surfaces by electrooligomerization on glassy carbon substrate (the two monomers with shorter alkyl chains), or as chiral additive in achiral ionic liquid (the monomer with longest alkyl chains). Discrimination is conveniently and reproducibly achieved in terms of significant potential differences for the two enantiomers, specularly inverting either probe or selector configuration. In one case successful discrimination is also observed with the two probe enantiomers concurrently present, either as racemate or with enantiomeric excesses, neatly accounted for by the peak current ratios.
Instant Photochromism Caused by Radical Formation in Photocatalytic Decarboxylation of Dihydrothiazole Derivative†
Authors: Xu Zhen , Malik Abaid Ullah , Shu Mouhai , Cui Yong 
Published: June 2021

Main observation and conclusionA pair of new enantiomeric compounds, (R)/(S)‐1,3,5‐benzene‐triyl‐2,2',2”‐tris(4,5‐dihydrothiazole‐4‐carboxylic acid) (H3LRRR and H3LSSS) are synthesized in one step synthetic route with high yield. Instant photochromism has been investigated to elaborate the photocatalytic decarboxylation of the dihydrothiazole derivative by electron paramagnetic resonance spectroscopy (EPR), photoluminescence (PL), FT‐IR, high resolution mass spectra, X‐ray photoelectron spectroscopy and UV‐Vis spectroscopic techniques. The results indicate that the photochromic transformation is originated from the formation of the radical during the photocatalytic decarboxylation of the 4,5‐dihydrothiazole‐4‐carboxylic acid units.
A phase 1b/2 study of azacitidine with PD‐L1 antibody avelumab in relapsed/refractory acute myeloid leukemia
Authors: Saxena Kapil , Herbrich Shelley M. , Pemmaraju Naveen , Kadia Tapan M. , DiNardo Courtney D. , Borthakur Gautam , Pierce Sherry A. , Jabbour Elias , Wang Sa A. , Bueso‐Ramos Carlos , Loghavi Sanam , Tang Guillin , Cheung Cora M. , Alexander Lynette , Kornblau Steven , Andreeff Michael , Garcia‐Manero Guillermo , Ravandi Farhad , Konopleva Marina Y. , Daver Naval 
Published: June 2021

BackgroundPatients with relapsed/refractory (R/R) acute myeloid leukemia (AML) have limited treatment options. In preclinical models of AML, inhibition of the PD‐1/PD‐L1 axis demonstrated antileukemic activity. Avelumab is an anti–PD‐L1 immune checkpoint inhibitor (ICI) approved in multiple solid tumors. The authors conducted a phase 1b/2 clinical trial to assess the safety and efficacy of azacitidine with avelumab in patients with R/R AML.MethodsPatients aged ≥18 years who had R/R AML received azacitidine 75 mg/m2 on days 1 through 7 and avelumab on days 1 and 14 of 28‐day cycles.ResultsNineteen patients were treated. The median age was 66 years (range, 22‐83 years), 100% had European LeukemiaNet 2017 adverse‐risk disease, and 63% had prior exposure to a hypomethylating agent. Avelumab was dosed at 3 mg/kg for the first 7 patients and at 10 mg/kg for the subsequent 12 patients. The most common grade ≥3 treatment‐related adverse events were neutropenia and anemia in 2 patients each. Two patients experienced immune‐related adverse events of grade 2 and grade 3 pneumonitis, respectively. The overall complete remission rate was 10.5%, and both were complete remission with residual thrombocytopenia. The median overall survival was 4.8 months. Bone marrow blasts were analyzed for immune‐related markers by mass cytometry and demonstrated significantly higher expression of PD‐L2 compared with PD‐L1 both pretherapy and at all time points during therapy, with increasing PD‐L2 expression on therapy.ConclusionsAlthough the combination of azacitidine and avelumab was well tolerated, clinical activity was limited. High expression of PD‐L2 on bone marrow blasts may be an important mechanism of resistance to anti–PD‐L1 therapy in AML.Lay Summary

This report describes the results of a phase 1b/2 study of azacitidine with the anti–PD‐L1 immune checkpoint inhibitor avelumab for patients with relapsed/refractory acute myeloid leukemia (AML).

The clinical activity of the combination therapy was modest, with an overall response rate of 10.5%.

However, mass cytometry analysis revealed significantly higher expression of PD‐L2 compared with PD‐L1 on AML blasts from all patients who were analyzed at all time points.

These data suggest a novel potential role for PD‐L2 as a means of AML immune escape.
Investigation for the color samples with equi‐depth in Natural Color System
Authors: Xie Wanzi , Wang Hongbo , Yang Hongying , Yang Zhihui , Zhang Jingjing , Kamruzzaman Md 
Published: June 2021

AbstractThe color depth, an important attribute of color, can reflect the amount of dye partly, which has important functions on the evaluation of color‐fastness and strength of dyes, dyeing effect of fabric, computer color matching, and so on. Natural Color System, an internationally accepted color system, orders colors by three parameters (blackness, chromaticness, and hue). The color depth has not been specified within the Natural Color System. This article tries to find the regularity of the sample with equal‐depth in Natural Color System. Firstly, 1950 color samples in Natural Color System were measured using an X‐Rite Color i7 Spectrophotometer, and their color depths were calculated by five color depth formulas. Then, trend analysis and mathematical modeling methods were used to achieve the connection between the color depth and the notations of Natural Color System basing on color depth theories. Results show that, in Natural Color System, the color samples with the same distance to pure white do not have equal depth; but the color samples with the same nuance (equal blackness, whiteness and chromaticness) have broadly equal color depth, and their average coefficient values are lower than that of Society of Dyers and Colourists Standard Depths. Besides, regressive formulas were built, with which the color depths of any chips in Natural Color System can be calculated broadly by their notation.
Utilization of Discarded Surgical Tissue from Ultrasonic Aspirators to Establish Patient‐Derived Metastatic Brain Tumor Cells: A Guide from the Operating Room to the Research Laboratory
Authors: Martirosian Vahan , Deshpande Krutika , Lin Michelle , Jarvis Casey , Yuan Edith , Chen Thomas C. , Zada Gabriel , Giannotta Steven L , Attenello Frank J , Chow Frances , Neman Josh 
Published: June 2021

AbstractPatient‐derived cells from surgical resections are of paramount importance to brain tumor research. It is well known that there is cellular and microenvironmental heterogeneity within a single tumor mass. Thus, current established protocols for propagating tumor cells in vitro are limiting because resections obtained from conventional singular samples limit the diversity in cell populations and do not accurately model the heterogeneous tumor. Utilization of discarded tissue obtained from cavitron ultrasonic surgical aspirator (CUSA) of the whole tumor mass allows for establishing novel cell lines in vitro from the entirety of the tumor, thereby creating an accurate representation of the heterogeneous population of cells originally present in the tumor. Furthermore, while others have described protocols for establishing patient tumor lines once tissue has arrived in the research lab, a primer from the operating room (OR) to the research lab has not been described before. This is integral, as basic research scientists need to understand the surgical environment of the OR, including the methods utilized to obtain a patient's tumor resection, in order to more accurately model cancer biology in laboratory. © 2021 Wiley Periodicals LLC.Basic Protocol 1: Establishment of brain tumor cell lines from patient‐derived CUSA samples: processing brain tumor sample from the OR to the labSupport Protocol 1: Sterilization of microsurgical tools in preparation for dissectionSupport Protocol 2: Collagen coating of tissue culture flasksBasic Protocol 2: Selection of tumor cells in vitroSupport Protocol 3: FACS sorting tumor sample to isolate cancer cells from heterogeneous cell population
Water in Protic Ionic Liquid Electrolytes: From Solvent Separated Ion Pairs to Water Clusters
Authors: Gehrke Sascha , Ray Promit , Stettner Timo , Balducci Andrea , Kirchner Barbara 
Published: June 2021

AbstractThe large electrochemical and cycling stability of “water‐in‐salt” systems have rendered promising prospective electrolytes for batteries. The impact of addition of water on the properties of ionic liquids has already been addressed in several publications. In this contribution, we focus on the changes in the state of water. Therefore, we investigated the protic ionic liquid N‐butyl‐pyrrolidinium bis(trifluoromethanesulfonyl)imide with varying water content at different temperatures with the aid of molecular dynamics simulations. It is revealed that at very low concentrations, the water is well dispersed and best characterized as shared solvent molecules. At higher concentrations, the water forms larger aggregates and is increasingly approaching a bulk‐like state. While the librational and rotational dynamics of the water molecules become faster with increasing concentration, the translational dynamics are found to become slower. Further, all dynamics are found to be faster if the temperature increases. The trends of these findings are well in line with the experimental measured conductivities.
Performance and Stability of Polymer : Nonfullerene Solar Cells with 100 °C‐Annealed Electron‐Collecting Combination Layers
Authors: Lee Woongki , Kim Hwajeong , Lee Chulyeon , Lee Sooyong , Kim Taehoon , Kim Youngkyoo 
Published: June 2021

AbstractInverted‐type organic solar cells, fabricated with low‐temperature‐processed combination layers of hybrid electron‐collecting buffer layers (ECBLs) consisting of zinc oxide (ZnO) and poly(2‐ethyl‐2‐oxazoline) (PEOz) and additional PEOz interlayers, showed improved performance and stability. The ZnO : PEOz precursor films with various PEOz compositions (0–12 wt %) were prepared and thermally treated at 100 °C, leading to the ECBLs on which the PEOz interlayers were subsequently deposited before coating of polymer : nonfullerene bulk heterojunction layers. Results showed that the power conversion efficiency of solar cells reached approximately 9.38 and 10.11 % (average) in case of the ZnO/PEOz and ZnO : PEOz(6 wt % PEOz)/PEOz combination layers, respectively, despite the low‐temperature thermal annealing process. A continuous irradiation test for 12 h under one sun condition (air mass 1.5G, 100 mW cm−2) disclosed that the devices with the ZnO : PEOz(6 wt % PEOz)/PEOz combination layers were more stable than those with the ZnO/PEOz layers.
Exposure to a fungal pathogen increases the critical thermal minimum of two frog species
Authors: Siddons Spencer R. , Searle Catherine L. 
Published: June 2021

AbstractThe ability of an organism to tolerate seasonal temperature changes, such as extremely cold temperatures during the winter, can be influenced by their pathogens. We tested how exposure to a virulent fungal pathogen, Batrachochytrium dendrobatidis (Bd), affected the critical thermal minimum (CTmin) of two frog species, Hyla versicolor (gray treefrog) and Lithobates palustris (pickerel frog). The CTmin is the minimum thermal performance point of an organism, which we estimated via righting response trials. For both frog species, we compared the righting response of Bd‐exposed and Bd‐unexposed individuals in either a constant (15ºC) environment or with decreasing temperatures (−1°C/2.5 min) starting from 15°C. The CTmin for both species was higher for Bd‐exposed frogs than unexposed frogs, and the CTmin of H. versicolor was higher than L. palustris. We also found that Bd‐exposed frogs of both species righted themselves significantly fewer times in both decreasing and constant temperature trials. Our findings show that pathogen exposure can reduce cold tolerance and limit the thermal performance range of hosts, which may lead to increased overwintering mortality.
Episodic recruitment in the saguaro cactus is driven by multidecadal periodicities
Authors: Félix‐Burruel Ricardo E. , Larios Eugenio , González Edgar J. , Búrquez Alberto 
Published: June 2021

AbstractEach year, an individual mature large saguaro cactus produces about one million seeds in attractive juicy fruits that lure seed predators and seed dispersers to a 3‐month feast. From the million seeds produced, however, only a few will persist into mature saguaros. A century of research on saguaro population dynamics has led to the conclusion that saguaro recruitment is an episodic event that depends on the convergence of suitable conditions for survival during the critical early stages. Because most data have been collected in Arizona, particularly in the surroundings of Tucson, most research has relied on a limited amount of environmental variation. In this study, we upscaled this knowledge on saguaro recruitment to a regional scale with a new method that used the inverse‐growth modeling of 1,487 saguaros belonging to 13 populations in a latitudinal gradient ranging from arid desert to tropical thornscrub forest in Sonora, Mexico. Using generalized linear and additive mixed models, we created two 110‐yr‐long saguaro recruitment curves: one driven only by previous size, and the second driven by size, drought, and soil structure. We found evidence that saguaro recruitment is indeed episodic, with periodicities of 20–30 yr, possibly related to strong El Niño Southern Oscillation events. Our results suggest that saguaros rely on multidecadal periodic pulses of good beneficial years to incorporate new individuals into their populations. Inverse‐growth modeling can be used in a wide variety of plant species to study their recruitment dynamics.
How and why plant ionomes vary across North American grasslands and its implications for herbivore abundance
Authors: Kaspari Michael , de Beurs Kirsten M. , Welti Ellen A. R. 
Published: June 2021

AbstractPlant elemental content can vary up to 1,000‐fold across grasslands, with implications for the herbivores the plants feed. We contrast the regulation, in grasses and forbs, of 12 elements essential to plants and animals (henceforth plant‐essential), 7 essential to animals but not plants (animal‐essential) and 6 with no known metabolic function (nonessential). Four hypotheses accounted for up to two thirds of the variation in grass and forb ionomes across 54 North American grasslands. Consistent with the supply‐side hypothesis, the plant‐essential ionome of both forbs and grasses tracked soil availability. Grass ionomes were more likely to harvest even nonessential elements like Cd and Sr. Consistent with the grazing hypothesis, cattle‐grazed grasslands also accumulated a handful of metals like Cu and Cr. Consistent with the NP‐catalysis hypothesis, increases in the macronutrients N and P in grasses were associated with higher densities of cofactors like Zn and Cu. The plant‐essential elements of forbs, in contrast, consistently varied as per the nutrient‐dilution hypothesis—there was a decrease in elemental parts per million with increasing local carbohydrate production. Combined, these data fit a working hypothesis that grasses maintain lower elemental densities and survive on nutrient‐poor patches by opportunistically harvesting soil nutrients. In contrast, nutrient‐rich forbs use episodes of high precipitation and temperature to build new carbohydrate biomass, raising leaves higher to compete for light, but diluting the nutrient content in every bite of tissue. Herbivores of forbs may thus be particularly prone to increases inpCO2via nutrient dilution.
Baseline characteristics of patients in the PARALLAX trial: insights into quality of life and exercise capacity in heart failure with preserved ejection fraction
Authors: Shah Sanjiv J. , Cowie Martin R. , Wachter Rolf , Szecsödy Peter , Shi Victor , Ibram Ghionul , Hu Mo , Zhao Ziqiang , Gong Jianjian , Pieske Burkert 
Published: June 2021

AbstractAimsWe sought to describe the baseline characteristics of PARALLAX [a randomized controlled trial of sacubitril/valsartan vs. individualized medical therapy in heart failure (HF) with mildly reduced and preserved ejection fraction (HFpEF)]; compare PARALLAX to recent HFpEF trials; and examine the clinical characteristics associated with quality of life (QOL) and 6‐min walk test distance (6MWD).Methods and resultsA total of 2566 patients with HF and left ventricular ejection fraction (LVEF) >40% were randomized, of whom 96% had an LVEF ≥45%. Multivariable linear regression was used to determine characteristics associated with Kansas City Cardiomyopathy Questionnaire clinical summary score (KCCQ‐CSS) and 6MWD. Mean age was 73 ± 8 years, 51% were female, and comorbidities were common. Of the QOL measures tested in PARALLAX, the Short Form Health Survey‐36 physical functioning score was most closely correlated with 6MWD (R = 0.41, P < 0.001), and outperformed the KCCQ physical limitation score (R = 0.33) and KCCQ‐CSS (R = 0.31) on multivariable analyses. Female sex, higher body mass index, history of coronary artery disease, lower LVEF, and higher N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) were associated with worse (lower) KCCQ‐CSS; older age, female sex, higher body mass index, diabetes, coronary artery disease, chronic obstructive pulmonary disease, prior HF hospitalization, lower LVEF, and higher NT‐proBNP were associated with shorter 6MWD (P < 0.05 for all associations).ConclusionsPARALLAX is the largest HFpEF study to date to examine 6MWD together with QOL. The KCCQ‐CSS and 6MWD were modestly correlated, and several factors were associated with worse values of both. These results provide insight into the association between QOL and exercise capacity in HFpEF.
Catalyst Activation and Chain Transfer Agents in Metallocene Catalysts for Ethylene Polymerization: A Computational Investigation
Authors: Kumawat Jugal , Gupta Virendra Kumar 
Published: June 2021

AbstractA density functional theory (DFT) study has been carried out to investigate the effect of various cocatalysts/chain transfer agents (such as Al(R)3, Mg(R)2, (R)Mg(Cl), Zn(R)2, (R)Zn(Cl), B(C6F5)3, and Al(C6F5)3, here, R=alkyl group) on catalyst activation and ethylene polymerization including chain transfer steps using (CpR, R’)2M(Cl)2 (M=Zr, Hf and R, R’=alkyl group) metallocenes. Initially, the catalyst alkylation step (where one of the chlorine atoms of the catalyst is replaced by an alkyl group of the cocatalyst) has been studied using the Al(Me)3, Mg(Me)2, (Me)Mg(Cl), Zn(Me)2, and (Me)Zn(Cl) moieties, and it was observed that the AlMe3 species is more effective for the alkylation step. Furthermore, a modification in the metallocene, such as (CpR, R’)2Zr(Cl)2, where R and R’=H, Me, Et, n‐propyl, iso‐propyl, iso‐butyl, tert‐butyl, and different combinations of those, has been performed to evaluate the effect of different alkyl substituents on the alkylation process, whereby it was found that the mono‐substituted metallocene favors the alkylation in comparison to bi‐substituted metallocene. Moreover, a detailed fundamental understanding of the ion pair formation step was gained by incorporating various steric and electronic factors of different alkyl groups, including fluorinated alkyl group bound on the Cp ligand. These results suggest that only B(C6F5)3 and Al(C6F5)3 activators could form the ion pairs by abstracting a methyl group from the metallocene. Additionally, the ethylene polymerization has also been investigated using B(C6F5)3 or Al(C6F5)3 cocatalyst, where B(C6F5)3 was found to be more effective towards polymerization. Furthermore, the Al(Me)3, Mg(R)2, (Me)Mg(Cl), Zn(R)2, and (Me)Zn(Cl) species have been employed as chain transfer agent (CTA). It has been observed that the magnesium‐ and zinc‐based species are more likely to behave as CTAs, and this process can be improved by changing the alkyl substituents on them. These chemical calculations shed light on catalyst alkylation and ethylene polymerization, including the chain transfer process, in metallocenes.
Enzymatic Synthesis of a Series of Thioglycosides: Analogs of Arbutin with Efficient Antipigmentation Properties
Authors: Peyrot Cédric , Didak Blanka , Guillotin Laure , Landemarre Ludovic , Lafite Pierre , Lemiègre Loïc , Daniellou Richard 
Published: June 2021

AbstractArbutin, a natural glycoside, is well known as a commercial tyrosinase inhibitor, and thus, to prevent pigmentary disorders of skin. In fact, tyrosinase is involved in the biosynthesis of melanin, the skin main pigment. However, arbutin is subject to hydrolysis, which limits its bioactivity. In general, thioglycosides are known to be very resistant to both chemical and enzymatic hydrolysis, which increases the interaction time with their biological targets. A biocatalytic approach allowed us to access to thioglycosidic analogs of arbutin in a green approach with good to excellent yields. Such compounds have then been tested as tyrosinase inhibitors as well as inhibitors of melanin transfer from melanocytes to keratinocytes. This latter mechanism takes place via lectin (or lectin‐like) receptors present on the cells surface. p‐Aminophenyl β‐D‐thiogalactopyranoside appears to be an excellent candidate thanks to its tyrosinase inhibitory activity comparable to arbutin, while having the ability to interact with glycan receptors allowing to reduce melanin transfer.