bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymermörtel‐Klebverbindungen für Holz‐Beton‐Verbundbrücken Teil 2
Authors: Kästner Martin , Rautenstrauch Karl 
Published: February 2021

AbstractLeistungsfähigkeit und Tragverhalten von Holz‐Beton‐Verbundkonstruktionen (HBV) sind entscheidend von der konstruktiven Ausbildung der Verbundfuge abhängig. Die meisten bislang für HBV‐Straßenbrücken entwickelten Verbundlösungen sind durch eine diskontinuierliche Schubübertragung gekennzeichnet, wobei die Schubtragfähigkeit des Holzes nicht optimal ausgenutzt wird. Ziel der im Beitrag vorgestellten Untersuchungen war die Entwicklung von Verbundfugenkonfigurationen mit kontinuierlichem Verbund zwischen Betonfahrbahnplatte und hölzernen Brückenhauptträgern. Zur Vergleichmäßigung der Schubbeanspruchung und zur Vermeidung tragfähigkeitsmindernder Spannungsspitzen im Bereich der Verbundelemente kommen mineralisch gefüllte, toleranzausgleichende Klebmörtel auf Epoxidharzbasis zum Einsatz. Die Beurteilung der Leistungsfähigkeit zweier weiterentwickelter Dübelleistenverbindungen mit Polymermörtelverguss sowie der direkten Polymermörtel‐Klebverbindung von Beton und Holz erfolgte anhand experimenteller und numerischer Untersuchungen. Der erste Teil des Beitrags gibt einen Überblick über die entwickelten Verbundfugenkonfigurationen und geeignete Polymermörtel und fokussiert auf die Ergebnisse der Untersuchungen zum Schubtragverhalten. Im vorliegenden zweiten Teil wird auf Untersuchungen an Biegeträgern eingegangen. Darüber hinaus werden die aus den Ergebnissen abgeleiteten Bemessungsvorschläge und Empfehlungen für die Ausführung vorgestellt.
On the Manganese Dissolution Process from LiMn2O4 Cathode Materials
Authors: Tesfamhret Yonas , Liu Haidong , Chai Zhigang , Berg Erik , Younesi Reza 
Published: February 2021

AbstractTransition metal (TM) dissolution is a process experienced by most cathode materials based on lithium transition metal oxides. Spinel LiMn2O4 (LMO) is the best‐known cathode material that suffers from TM dissolution. Therefore, LMO is selected here to understand the dissolution process and derive an inductively coupled plasma optical emission spectroscopy (ICP‐OES) method for quantifying dissolved metal ions. Furthermore, the LMO powder is coated with thin Al2O3 films of different thicknesses using atomic layer deposition (ALD) in an attempt to suppress the dissolution of Mn. Two different types of counter electrodes, lithium iron phosphate (LFP) and Li‐metal, were used to investigate the role of the counter electrode on Mn dissolution. HF is identified as the lead cause of Mn dissolution, through comparisons of cells containing LiPF6 or LiClO4 based electrolytes. The results show that Li‐metal counter electrode effectively minimizes the dissolution process via likely consuming HF and H2O impurity. In contradiction to the purpose of the protective Al2O3 thin film coating, surface coated LMO showed higher dissolution of Mn compared to pristine LMO, both in LFP||LMO and Li||LMO configurations. Al2O3 is proposed to generate H2O when reacts with HF. H2O could have the possibility to migrate back in the electrolyte and participate in the hydrolysis of LiPF6, resulting in more HF and thereby more Mn dissolution.
Potassium‐Ion Activating Formation of Fe−N−C Moiety as Efficient Oxygen Electrocatalyst for Zn‐Air Batteries
Authors: Arif Khan Muhammad , Sun Congli , Cai Jian , Ye Daixin , Zhao Kangning , Zhang Guobing , Shi Shanshan , Ali Shah Luqman , Fang Jianhui , Yang Chao , Zhao Hongbin , Mu Shichun , Zhang Jiujun 
Published: February 2021

AbstractDeveloping a new synthesis methodology to obtain an economical and stable single atom oxygen reduction reaction (ORR) catalyst is highly desirable. Herein, we develop a general ionic salt assisted template method to obtain M−N−C (M=Fe and Co) catalyst with improved ORR activity. The creation of M−N−C single atom catalyst is highly dependent on the nature of ionic salt templates. Compared with NaCl, KCl can not only act as template, but also create more defect sites for single iron atom to anchor through metallic K‐intercalation activation at elevated temperatures, which results in the generation of more single atomic M−N−C active sites. Furthermore, the ionic salt template‐assisted method leads to the formation of interconnected porous structure with sufficient micropores and a high surface area of 514 m2 g−1. As an ORR and Zn‐air battery catalyst, Fe−N−C−KCl shows a half‐wave potential of 0.877 V and a maximum power density of 185 mW cm−2, respectively, outperforming those of state‐of‐the‐art Pt/C catalyst. The general ionic salt assisted method is a promising strategy for developing efficient and robust catalysts, electrode materials towards economic platinum‐free zinc‐air batteries and other energy storage systems.
Endohedral Hydrogen Bonding Templates the Formation of a Highly Strained Covalent Organic Cage Compound**
Authors: Schäfer Natalie , Bühler Michael , Heyer Lisa , Röhr Merle I. S. , Beuerle Florian 
Published: February 2021

AbstractA highly strained covalent organic cage compound was synthesized from hexahydroxy tribenzotriquinacene (TBTQ) and a meta‐terphenyl‐based diboronic acid with an additional benzoic acid substituent in 2’‐position. Usually, a 120° bite angle in the unsubstituted ditopic linker favors the formation of a [4+6] cage assembly. Here, the introduction of the benzoic acid group is shown to lead to a perfectly preorganized circular hydrogen‐bonding array in the cavity of a trigonal‐bipyramidal [2+3] cage, which energetically overcompensates the additional strain energy caused by the larger mismatch in bite angles for the smaller assembly. The strained cage compound was analyzed by mass spectrometry and 1H, 13C and DOSY NMR spectroscopy. DFT calculations revealed the energetic contribution of the hydrogen‐bonding template to the cage stability. Furthermore, molecular dynamics simulations on early intermediates indicate an additional kinetic effect, as hydrogen bonding also preorganizes and rigidifies small oligomers to facilitate the exclusive formation of smaller and more strained macrocycles and cages.
Enantioselective Nickel‐Catalyzed anti‐Arylmetallative Cyclizations onto Acyclic Ketones
Authors: Green Harley , Argent Stephen P. , Lam Hon Wai 
Published: February 2021

AbstractDomino reactions involving nickel‐catalyzed additions of (hetero)arylboronic acids to alkynes, followed by cyclization of the alkenylnickel intermediates onto tethered acyclic ketones to give chiral tertiary‐alcohol‐containing products in high enantioselectivities, are described. The reversible E/Z isomerization of the alkenylnickel intermediates enables overall anti‐arylmetallative cyclization to occur. The ring system of the products are substructures of certain diarylindolizidine alkaloids.
Conformational Switching through the One‐Electron Reduction of an Acridinium‐based, γ‐Cationic Phosphine Gold Complex
Authors: Liu Wei‐Chun , Kim Youngmin , Gabbaï François P. 
Published: February 2021

AbstractOur efforts in the chemistry of gold complexes featuring ambiphilic phosphine‐carbenium L/Z‐type ligand have led us to consider the reduction of the carbenium moiety as a means to modulate the gold–carbenium interaction present in these complexes. Here, it was shown that the one‐electron reduction of [(o‐Ph2P(C6H4)Acr)AuCl]+ (Acr=9‐N‐methylacridinium) produces a neutral stable radical, the structure of which showed a marked increase in the Au–Acr distance. Related structural changes were observed for the phosphine oxide analogue [(o‐Ph2P(O)(C6H4)Acr]+, the reduction of which interfered with the P=O→carbenium interaction. These structural effects, driven by a reduction‐induced change in the electronic and electrostatic characteristics of the compounds, showed that the charge and accepting properties of the carbenium unit can be modulated. These results highlight the redox‐noninnocence of carbenium Z‐type ligand, a feature that can be exploited to induce specific conformational changes.
Removal of Arsenic from Water Using a Composite of Iron–Manganese Oxide Incorporated Active Rice Husk Silica
Authors: Bui Trung Huu , Pham Van Sy , Thanh‐Nho Nguyen , Trieu Quoc An 
Published: February 2021

AbstractLow‐cost adsorbents from agricultural by‐products are intensively studied in water treatment, especially in arsenic removal for obtaining safe drinking water. Here, it is reported that a cheap and effective nano‐composite of iron–manganese oxide incorporated active rice husk silica (FMRS) for efficient removal of arsenic (As(III) and As(V)) from water, which is fabricated using a one‐pot synthesis. Fe3+ and Mn4+ in their oxides supported silica structure are successfully characterized. The FMRS (qe = 11.9 mg g−1) shows a remarkable enhancement of arsenic removal compared with the original rice husk ash (qe = 0.4 mg g−1) at initial [As(V)] = 5 mg L−1. The As(III) and As(V) adsorption are in good agreement with both Langmuir and Freundlich non‐linear isotherm models (R2 > 0.98), where the maximum adsorption capacities at pH 7 are found up to 19.1 and 20.3 mg g−1, respectively. The role of Mn4+ in enhancing the As(III) adsorption is also discussed. The FMRS exhibits high selectivity toward arsenic under the influences of other co‐existing anions in water (e.g., chloride, sulfate, and bicarbonate) and sustains a good arsenic removal efficiency during four cycles of the reusability test, suggesting a high potential of the fabricated adsorbent for long‐term removal of arsenic in field application.
Pharmacology of HIV Cure: Site of Action
Authors: Devanathan Aaron S. , Cottrell Mackenzie L. 
Published: February 2021

Despite significant advances in HIV treatment over the past 30 years, critical barriers to an HIV cure persist. The HIV reservoir, defined at both the cellular and anatomical level, constitutes the main barrier to cure. While the mechanisms underlying the reservoir are not yet well understood, one theory to explain persistence at the anatomical level is that subtherapeutic exposure to antiretroviral therapy (ART) within certain tissue compartments permits ongoing replication. Characterizing ART pharmacology throughout the body is important in the context of these potential pharmacologic sanctuaries and for maximizing the probability of success with forthcoming cure strategies that rely on latency reversal and require ART to prevent reseeding the reservoir. In this review, we provide a comprehensive overview of ART and latency reversal agent distribution at the site of action for HIV cure (i.e., anatomical sites commonly associated with HIV persistence, such as lymphoid organs and the central nervous system). We also discuss methodologic approaches that provide insight into HIV cure pharmacology, including experimental design and advances within the computational, pharmaceutical, and analytical chemistry fields. The information discussed in this review will assist in streamlining the development of investigational cure strategies by providing a roadmap to ensure therapeutic exposure within the site of action for HIV cure.
Importance of antibody isotypes in antitumor immunity by monocytes and complement using human‐immune tumor models
Authors: Lara Sandra , Anania Jessica C. , Virtanen Alexander , Stenhammar Viktoria , Kleinau Sandra 
Published: February 2021

AbstractMonoclonal antibodies (mAbs) have revolutionized clinical medicine, especially in the field of cancer immunotherapy. The challenge now is to improve the response rates, as immunotherapy still fails for many patients. Strategies to enhance tumor cell death is a fundamental aim, but relevant model systems for human tumor immunology are lacking. Herein, we have developed a preclinical human immune – three‐dimensional (3D) tumor model (spheroids) to map the efficiency of tumor‐specific isotypes for improved tumor cell killing. Different anti‐CD20 Rituximab (RTX) isotypes alone or in combination, were evaluated for mediating complement‐dependent cytotoxicity and antibody‐dependent phagocytosis by human monocytic cells in 3D spheroids, in parallel with monolayer cultures, of human CD20+ B‐cell lymphomas. We demonstrate that the IgG3 variant of RTX has the greatest tumoricidal effect over other isotypes, and when combined with apoptosis‐inducing RTX‐IgG2 isotype the therapeutic effect can be substantially enhanced. The results show further that the treatment outcome by RTX isotypes is influenced by tumor morphology and expression of the complement inhibitor CD59. Hence, the human immune‐3D tumor model is a clinical relevant and attractive ex vivo system to predict mAbs for best efficacy in cancer immunotherapy.
Iron‐Catalyzed Electrophilic Amination of Sodium Sulfinates with Anthranils
Authors: Liang Baihui , Huang Junjie , Zhu Weidong , Li Yawen , Jiang Lanping , Gao Yang , Xie Feng , Li Yibiao , Chen Xiuwen , Zhu Zhongzhi 
Published: February 2021

AbstractA practical method for the synthesis of N‐(2‐carbonylaryl) benzenesulfonamides via an iron‐catalyzed electrophilic amination of sodium sulfinates with anthranils is described. This redox‐neutral transformation has high atom efficiency and is achieved under simple and mild reaction conditions. A wide range of anthranils and sodium sulfinates were compatible in this transformation. Moreover, the synthetic potential of this methodology was further demonstrated by the synthesis of various useful N‐heterocycles and derivatives.
Diaryliodonium Salts in Transition‐Metal‐Catalyzed Chelation‐Induced C(sp2/sp3)−H Arylations
Authors: Joshi Asha , De Saroj Ranjan 
Published: February 2021

AbstractTransition‐metal‐catalyzed Cross‐coupling via directing group assisted C−H bond activation has become an expedient tool in current synthesis to achieve diverse molecular complexity. In this context, chelation‐assisted arylations of C(sp2/sp3)−H bonds have been extensively investigated as aryl/biaryl derivatives are an important contributor in the area of the industry, farming, medicinal and material science. The diaryliodonium salt has been broadly utilized in C(sp2/sp3)−H bond arylation where the reaction proceeds via oxidative addition of aryliodonium salt to chelation induced metallacycle. The proximal/remote C(sp2/sp3)−H bonds in coordination with transition metals are arylated by a range of directing groups in good to excellent yields. In this mini‐review, we have outlined the up to date developments on transition‐metal‐catalyzed chelation assisted C(sp2/sp3)−H bond arylation utilizing diaryliodonium salts as the coupling partner.
What causes the Strength‐is‐Weakness effect in coalition formation: Passive adoption or active selection of self‐serving allocation rules?
Authors: Wissink Joeri , van Beest Ilja , Pronk Tila , van de Ven Niels 
Published: February 2021

AbstractIn coalition formation, bargainers with many resources are often excluded from coalitions (the Strength‐is‐Weakness effect). Literature suggests this effect is driven by high‐resource bargainers using self‐serving allocation rules that backfire, as they prefer equity over equality (while low‐resource bargainers prefer the opposite). Four studies test (1) whether this is actually the case and (2) whether high‐resource bargainers solely consider equitable allocations or whether they consider both equity and equality but actively choose equity as an allocation rule. We find the Strength‐is‐Weakness effect even when equality rules are made salient, strengthening the idea that the high‐resource bargainers actively select equity as their framework for fairness to attempt to maximize their outcomes. The studies, also suggest an additional reason for the exclusion of high‐resource bargainers. We find that high‐resource bargainers are likely avoided because they are expected to bargain self‐servingly, making the low‐resource bargainers seek each other out.
“We are the victims of racism”: Victim categories in negotiating claims about racism against Black‐Africans in India
Authors: Sambaraju Rahul 
Published: February 2021

AbstractHow is racism negotiated by those who are otherwise victims of racism? Social psychologists show the relevance of categorization in negotiating racism. In the present article I focus on a setting where the majority group itself can be considered a target of racism: racism against Black‐Africans in India. I examine how victim categorization of the majority group is developed and used through a membership categorization analysis of broadcast media news debates. Analysis shows that, first, victim categories complicated the use of racial prejudice as an explanation for the attacks. Second, victim categorizations were developed in relation to social groups that were removed from the present setting. These allowed for accomplishing specific actions: denials and rejections of racism, moral concerns in racism, and acceptance of Black‐Africans' claims about racism. Together, the findings show that racism can be negotiated in terms additional to racial/ethnic group membership: as victims or perpetrators of racism.
Empirically derived guidelines for effect size interpretation in social psychology
Authors: Lovakov Andrey , Agadullina Elena R. 
Published: February 2021

AbstractThis study estimates empirically derived guidelines for effect size interpretation for research in social psychology overall and sub‐disciplines within social psychology, based on analysis of the true distributions of the two types of effect size measures widely used in social psychology (correlation coefficient and standardized mean differences). Analysis of empirically derived distributions of 12,170 correlation coefficients and 6,447 Cohen's d statistics extracted from studies included in 134 published meta‐analyses revealed that the 25th, 50th, and 75th percentiles corresponded to correlation coefficient values of 0.12, 0.24, and 0.41 and to Cohen's d values of 0.15, 0.36, and 0.65 respectively. The analysis suggests that the widely used Cohen's guidelines tend to overestimate medium and large effect sizes. Empirically derived effect size distributions in social psychology overall and its sub‐disciplines can be used both for effect size interpretation and for sample size planning when other information about effect size is not available.
Nonenzymatic Electrochemical Sensor for Wearable Interstitial Fluid Glucose Monitoring
Authors: Lei Lanjie , Zhao Chao , Zhu Xiaofei , Yuan Shuai , Dong Xing , Zuo Yinxiu , Liu Hong 
Published: February 2021

AbstractWe report on a nonenzymatic electrochemical sensor for wearable glucose monitoring in interstitial fluid. The sensor exhibited acceptable selectivity and reliability for continuous glucose detection for up to 30 days. The sensor tip is coated with polyurethane, and the biocompatibility of the tip is investigated by tissue staining. A fully integrated wearable glucose monitoring system is developed with a wireless connection with a smartphone. The test results are in agreement with reference methods. So, we believe the sensor is promising for the development of a continuous glucose monitoring system and diabetes management.
Chronic Exposure to Environmental DDT/DDE in 2 Species of Small Rodents: Measures of Contaminant Load, Immune Dysfunction, and Oxidative Stress
Authors: Molina Erica M. , Kavazis Andreas N. , Mendonça Mary T. 
Published: February 2021

Abstract
Persistent contaminants are ubiquitous in our water and soil, and thus chronic exposure to environmentally relevant levels of these contaminants may pose a risk to humans and wildlife. Two species of small mammals (deer mouse, Peromyscus maniculatus and cotton rat, Sigmodon hispidus) were collected from historically dichlorodiphenyltrichloroethane (DDT)-contaminated and reference areas at the Redstone Arsenal (Huntsville, AL, USA), a US Environmental Protection Agency (USEPA)-designated Superfund site. Soil samples taken concurrently with mammal collection from the DDT abatement site exhibited DDT and dichlorodiphenyldichloroethylene (DDE) levels &gt;1 ppm (USEPA total threshold limit concentration for DDT and DDE &lt;1 ppm), whereas soil samples from the reference area had undetectable levels. Liver samples from individuals of both species collected in the contaminated areas also had significantly elevated DDT/DDE levels, with P. maniculatus averaging an approximately 20× greater load than that documented for S. hispidus. Both rodent species collected from the contaminated site had significantly lower total leukocyte counts and total differential blood cell counts (p = 0.01 and p = 0.04, respectively) than those collected from the nearby (~7000-m) reference site. Cellular stress indices also trended higher in both species, suggesting a potential for chronic exposure to DDT to act as a mediator of oxidative damage. The present study provides support to the idea that environmental exposure to low levels of contaminants can cause physiological consequences that may influence immune responsiveness and initiate cellular stress in resident mammals. Environ Toxicol Chem 2021;40:1619–1629. © 2021 SETAC
Abstract
Chronic rodent exposure to dichlorodiphenyltrichloroethanes within the soil has the potential to cause immune dysfunction and increase oxidative stress in rodents inhabiting superfund sites. HSP = heat shock protein; WBC = white blood cell; DDT = dichlorodiphenyltrichloroethane; DDE = dichlorodiphenyldichloroethylene; DDD = dichlorodiphenyldichloroethane.
Design of Chiral NHC‐Carboxylates as Potential Ligands for Pd‐Catalyzed Enantioselective C−H Activation
Authors: Niggli Nadja E. , Baudoin Olivier 
Published: February 2021

AbstractDespite numerous efforts, the synthesis of scalemic carbo‐ and heterocycles through Pd0‐catalyzed C(sp3)−H activation employing chiral ancillary ligands or chiral bases is still limited. Inspired by the recently reported outstanding performance of IBiox‐type NHC ligands and bifunctional ligands in similar transformations, a new class of bifunctional NHC‐ligands bearing a pendant carboxylate group was designed. A library of 10 imidazolium‐carboxylic acids was obtained in five to six steps from enantiopure l‐tert‐leucinol. In addition, four well‐defined Pd(DMBPA)‐NHC palladacycles were synthesized in good to excellent yields from the corresponding imidazolium precursors. These complexes were tested in a prototypical C(sp3)−H arylation reaction, and the most active one afforded the indoline product in low yield but significant enantioselectivity. These new bifunctional NHCs could find broader applications in catalytic enantioselective transformations occurring under milder conditions.