bluuebunny/crossref_metadata_2025_split huggingface dataset:
gem‐Diol‐Type Intermediate in the Activation of a Ketone on Sn‐β Zeolite as Studied by Solid‐State NMR Spectroscopy
Authors: Qi Guodong , Chu Yueying , Wang Qiang , Wang Xingxing , Li Yi , Trébosc Julien , Lafon Olivier , Xu Jun , Deng Feng 
Published: May 2020

AbstractLewis acid zeolites have found increasing application in the field of biomass conversion, in which the selective transformation of carbonyl‐containing molecules is of particular importance due to their relevance in organic synthesis. Mechanistic insight into the activation of carbonyl groups on Lewis acid sites is challenging and critical for the understanding of the catalytic process, which requires the identification of reaction intermediates. Here we report the observation of a stable surface gem‐diol‐type species in the activation of acetone on Sn‐β zeolite. 13C, 119Sn, and 13C–119Sn double‐resonance NMR spectroscopic studies demonstrate that only the open Sn site ((SiO)3Sn‐OH) on Sn‐β is responsible for the formation of the surface species. 13C MAS NMR experiments together with density functional theory calculations suggest that the gem‐diol‐type species exhibits high reactivity and can serve as an active intermediate in the Meerwein—Ponndorf–Verley–Oppenauer (MPVO) reaction of acetone with cyclohexanol. The gem‐diol‐type species offers an energy‐preferable pathway for the direct carbon‐to‐carbon hydrogen transfer between ketone and alcohol. The results provide new insights into the transformation of carbonyl‐containing molecules catalyzed by Lewis acid zeolites.
Toponyms from 3000 years ago? Implications for the history and structure of the Yolŋu social formation in north‐east Arnhem Land
Authors: MORPHY FRANCES , MORPHY HOWARD , FAULKNER PATRICK , BARBER MARCUS 
Published: May 2020

ABSTRACTThe paper focuses on a set of toponyms found on the coast of Blue Mud Bay in northern Australia, in an area today occupied by Yolŋu (Murngin) peoples. In the first part of the paper, we present an analysis, based on geomorphological, archaeological, anthropological and linguistic evidence, to suggest that these toponyms have been in place for at least 3000 years, and that they are early Yolŋu toponyms. We then argue that certain social practices and cultural mechanisms, which continue today, work to form a complex, multi‐media and multi‐sensory archive of names‐in‐place, within the frame of a robust system of intergenerational transmission. It is plausible that such a system has considerable time‐depth. Yolŋu oral histories suggest, indeed, that Blue Mud Bay was the origin point from which Yolŋu‐Matha languages and Yolngu forms of kinship and governance then spread inland to the north, west and south.
Au Nanoparticles Modified with Pt, Ru and SnO2 as Electrocatalysts for Ethanol Oxidation Reaction in Acids
Authors: Siddharth Kumar , Xing Zelong , Xiao Fei , Zhu Shangqian , Zhang Lili , Pan Feng , Shao Minhua 
Published: May 2020

AbstractThe anodic reaction in direct ethanol fuel cells (DEFCs), ethanol oxidation reaction (EOR) faces challenges, such as incomplete electrooxidation of ethanol and high cost of the most efficient electrocatalyst, Pt in acidic media at low temperature. In this study, core‐shell electrocatalysts with an Au core and Pt‐based shell (Au@Pt) are developed. The Au core size and Pt shell thickness play an important role in the EOR activity. The Au size of 2.8 nm and one layer of Pt provide the most optimized performance, having 6 times higher peak current density in contrast to commercial Pt/C. SnO2 as a support also enhances the EOR activity of Au@Pt by 1.73 times. Further modifying the Pt shell with Ru atoms achieve the highest EOR current density that is 15 and 2.5 times of Pt/C and Au@Pt. Our results suggest the importance of surface modification in rational design of advanced electrocatalysts.
From Toddlerhood to Adolescence, Trajectories and Predictors of Outcome: Long‐Term Follow‐Up Study in Autism Spectrum Disorder
Authors: Zachor Ditza A. , Ben‐Itzchak Esther 
Published: May 2020

This study is one of a very few prospective long‐term studies in autism spectrum disorder (ASD). The study compared outcome trajectories in three adolescent groups (T2): “best outcome” (BO, n = 11) did not meet cut‐off points for ASD and IQ scores ≥85; high functioning (HF‐ASD, n = 14); and lower functioning (LF‐ASD, n = 43). Additionally, the study searched for characteristics at toddlerhood (T1) that may predict belonging to the above groups. The study included 68 adolescents (63 males) diagnosed with ASD at toddlerhood (mean age: 13:10 years), mean follow‐up time was 11:7 years. Participants underwent comprehensive assessments at T1 and T2. Different trajectories were found for the three defined groups. The BO group improved significantly in cognitive ability, autism severity, and adaptive skills in comparison to no improvement for the LF‐ASD group or partial progress for the HF‐ASD group. At toddlerhood, better cognition and less severe autism social affect symptoms were generally associated with a better outcome. Early social behaviors including better “pointing,” “facial expression directed to others,” “showing,” and “response to joint attention” were associated with membership in the BO group. In addition, the BO group had the lowest prevalence of significant T2 inattention and anxiety symptoms. No significant differences between the three outcome groups were noted in the birth and prevalence of medical problems. Higher cognitive ability and better T1 showing and pointing behaviors predicted better outcome. The study points to the change in autism severity over time and to the prognostic value of early developmental abilities, social engagement behaviors, and the existence of comorbidities. Autism Res 2020, 13: 1130‐1143. © 2020 International Society for Autism Research and Wiley Periodicals LLC.Lay SummaryThis long‐term study compared characteristics of toddlers diagnosed with autism spectrum disorder (ASD) in three outcome groups in adolescence: best outcome (BO‐average IQ/not meeting criteria for ASD), high‐functioning ASD, and low‐functioning ASD (LF‐ASD). At toddlerhood, the BO group displayed less severe autism symptoms, mostly in sharing interests, compared to the LF‐ASD group. The BO group had fewer inattention and anxiety symptoms than the two ASD groups. Additionally, early cognitive level and social engagement behaviors predicted outcome in ASD.
A note on the interpretation of tree‐based regression models
Authors: Gottard Anna , Vannucci Giulia , Marchetti Giovanni Maria 
Published: May 2020

AbstractTree‐based models are a popular tool for predicting a response given a set of explanatory variables when the regression function is characterized by a certain degree of complexity. Sometimes, they are also used to identify important variables and for variable selection. We show that if the generating model contains chains of direct and indirect effects, then the typical variable importance measures suggest selecting as important mainly the background variables, which have a strong indirect effect, disregarding the variables that directly influence the response. This is attributable mainly to the variable choice in the first steps of the algorithm selecting the splitting variable and to the greedy nature of such search. This pitfall could be relevant when using tree‐based algorithms for understanding the underlying generating process, for population segmentation and for causal inference.
Crispr/Cas9‐mediated cleavages facilitate homologous recombination during genetic engineering of a large chromosomal region
Authors: Zhang Fan , Cheng De , Wang Shuwen , Zhu Jiyue 
Published: May 2020

AbstractHomologous recombination over large genomic regions is difficult to achieve due to low efficiencies. Here, we report the successful engineering of a humanized mTert allele, hmTert, in the mouse genome by replacing an 18.1‐kb genomic region around the mTert gene with a recombinant fragment of over 45.5 kb, using homologous recombination facilitated by the Crispr/Cas9 technology, in mouse embryonic stem cells (mESCs). In our experiments, with DNA double‐strand breaks (DSBs) generated by Crispr/Cas9 system, the homologous recombination efficiency was up to 11% and 16% in two mESC lines TC1 and v6.5, respectively. Overall, we obtained a total of 27 mESC clones with heterozygous hmTert/mTert alleles and three clones with homozygous hmTert alleles. DSBs induced by Crispr/Cas9 cleavages also caused high rates of genomic DNA deletions and mutations at single‐guide RNA target sites. Our results indicated that the Crispr/Cas9 system significantly increased the efficiency of homologous recombination‐mediated gene editing over a large genomic region in mammalian cells, and also caused frequent mutations at unedited target sites. Overall, this strategy provides an efficient and feasible way for manipulating large chromosomal regions.
Method development and validation for simultaneous determination of ebastine and its active metabolite carebastine in human plasma by liquid chromatography–tandem mass spectrometry and its application to a clinical pharmacokinetic study in healthy Chinese volunteers
Authors: Phiri Margaret , Li Duo , Li Tengfei , Ji Shunli , Ling Tang , Li Xianjing , Gao Huaye , Ding Li , Shu Chang 
Published: May 2020

AbstractA simple LC–tandem mass spectrometry (MS/MS) method to determine ebastine and carebastine (active metabolite) in human plasma was developed and validated. Analytes and internal standards were precipitated by protein precipitation and separated on Synergi Hydro‐RP 80A column (4 μm, 50 mm × 2.0 mm; Phenomenex) by gradient elution with mobile phase A comprising 0.1% formic acid in 5 mm ammonium acetate (NH4Ac) and B comprising 100% methanol at a flow rate 0.4 mL/min. Ions were detected in positive multiple reaction monitoring mode, and they exhibited linearity over concentration range 0.01–8.0 and 1.00–300 ng/mL for ebastine and carebastine, respectively. A clinical pharmacokinetic study was conducted in healthy Chinese volunteers under fasting and fed conditions after a single oral administration of 10 mg ebastine. The maximum plasma concentration (Cmax), time to Cmax (Tmax) and elimination half‐life for ebastine were 0.679 ± 0.762 ng/mL, 1.67 ± 1.43 h and 7.86 ± 6.18 h, respectively, whereas these for carebastine were 143 ± 68.4 ng/mL, 5.00 ± 2.00 h and 17.4 ± 4.97 h, respectively under fasting conditions; the corresponding values under fed conditions were 4.13 ± 2.53 ng/mL, 3.18 ± 1.09 h and 21.6 ± 7.77 h for ebastine and 176 ± 68.4 ng/mL, 6.14 ± 2.0 h and 20.0 ± 4.97 h for carebastine.
LC‐APCI‐MS/MS assay for quantitation of ethyl esters of eicosapentaenoic acid and docosahexaenoic acid in human plasma and its application in a pharmacokinetic study
Authors: Li Le , Xia Ying , Zhao Shunbo , Ding Li , Ji Shunli 
Published: May 2020

AbstractA simple and specific LC–MS/MS method was developed and validated for the determination of ethyl ester of eicosapentaenoic acid (EPAEE) and ethyl ester of docosahexaenoic acid (DHAEE). After deproteinized with acetonitrile, the plasma samples were separated on a C18 column using a gradient elution system consisted of methanol and 1.0 mM ammonium acetate in water. The detection used an atmospheric‐pressure chemical ionization ion source in positive mode with multiple reaction monitoring for the quantitation of EPAEE and DHAEE. The acceptable linearity was achieved over the concentration ranges of 1.00~1000 ng/mL for EPAEE and 2.50~2500 ng/mL for DHAEE. The method was successfully applied to a pharmacokinetic study of EPAEE and DHAEE in healthy Chinese volunteers after the oral administration of 4 g omega‐3‐acid ethyl esters 90 soft capsule. The pharmacokinetic profiles of EPAEE and DHAEE were observed for the first time in Chinese volunteers, which reached a maximum concentration of 499 ± 243 ng/mL and 1596 ± 476 ng/mL for EPAEE and DHAEE, respectively. The areas under the plasma concentration–time curve were 1290 ± 765 ng/mL·h for EPAEE and 4369 ± 1680 ng/mL·h for DHAEE, respectively.
Physicochemical evaluation of new tetrahydroacridine and iodobenzoic acid hybrids as the next step in the design of potential drugs for treating Alzheimer's disease
Authors: Kręcisz Paweł , Czarnecka Kamila , Szymański Paweł 
Published: May 2020

AbstractTacrine derivatives containing iodobenzoic acid were developed as a novel multitarget‐directed ligand and find potential application in the treatment of Alzheimer's disease. The aim of this study is to perform a physicochemical profile of this series. Experimental log P and pKa values were determined and compared with those already calculated. The results indicated better values of the tested compounds than the values predicted using computer software. The stability report was obtained using the developed HPLC method. The stability assay in different environment conditions provided information about the photosensitivity of these compounds and a proper method for the storage of this series of compounds.
Circular RNA hsa_circ_0085131 is involved in cisplatin‐resistance of non‐small‐cell lung cancer cells by regulating autophagy
Authors: Kong Rui 
Published: May 2020

AbstractNon‐small‐cell lung carcinoma (NSCLC) continues to top the list of cancer mortalities worldwide. The role of circular RNAs (circRNAs) in tumorigenesis has been increasingly appreciated, although it is relatively unexplored in NSCLC. Herein, we reported the role of hsa_circ_0085131 in NSCLC. In the present study, NSCLC tumor specimens exhibited a higher hsa_circ_0085131 level in comparison to para‐tumor samples. And the higher level of hsa_circ_0085131 was associated with recurrence and poorer survival of NSCLC. Moreover, hsa_circ_0085131 promoted cell proliferation and cisplatin (DDP)‐resistance. Furthermore, hsa_circ_0085131 regulated cell DDP‐resistance by modulating autophagy. Hsa_circ_0085131 acted as a competing endogenous RNA of miR‐654‐5p to release autophagy‐associated factor ATG7 expression, thereby promoting cell chemoresistance. In conclusion, hsa_circ_0085131 enhances DDP‐resistance of NSCLC cells through sequestering miR‐654‐5p to upregulate ATG7, leading to cell autophagy. Therefore, these findings advocate targeting the hsa_circ_0085131/miR‐654‐5p/ATG7 axis as a potential therapeutic option for patients with NSCLC who are resistant to DDP.
Electrical impedance tomography reveals pathophysiology of neonatal pneumothorax during NAVA
Authors: Kallio Merja , Rahtu Marika , van Kaam Anton H. , Bayford Richard , Rimensberger Peter C. , Frerichs Inéz 
Published: May 2020

AbstractPneumothorax is a potentially life‐threatening complication of neonatal respiratory distress syndrome (RDS). We describe a case of a tension pneumothorax that occurred during neurally adjusted ventilatory assist (NAVA) in a preterm infant suffering from RDS. The infant was included in a multicenter study examining the role of electrical impedance tomography (EIT) in intensive care and therefore continuously monitored with this imaging method. The attending physicians were blinded for EIT findings but offline analysis revealed the potential of EIT to clarify the underlying cause of this complication, which in this case was heterogeneous lung disease resulting in uneven ventilation distribution. Instantaneous increase in end‐expiratory lung impedance on the affected side was observed at time of the air leak. Real‐time bedside availability of EIT data could have modified the treatment decisions made.
Active fixation coronary sinus lead in a patient with persistence of left superior vena cava
Authors: Caravati Fabrizio , Golino Michele , Damiani Giulia , Oliviero Giada , Vecchi Andrea Lorenzo , Giuntini Chiara , Paganini Edoardo Maria , De Ponti Roberto 
Published: May 2020

AbstractIn patients with PLSVC, the use of an active fixation lead (like the Medtronic “Attain Stability”) on the coronary sinus can lead to a successful and safe cardiac resynchronization, facilitating its positioning with a low long‐term displacement rate.
Metal‐Free Cycloaddition of Epoxides and Carbon Dioxide Catalyzed by Triazole‐Bridged Bisphenol
Authors: Hao Yanhong , Yuan Dan , Yao Yingming 
Published: May 2020

Abstract1,2,3‐triazole‐bridged bisphenol has been developed as organocatalyst in the coupling of CO2 and epoxides. In the absence of halide co‐catalyst, halomethyl‐substituted epoxides reacted with 1 bar CO2, while a series of aryl‐substituted epoxides were transformed into cyclic carbonates in 57–95 % yields at 120 °C and 10 bar pressure. 1,2,3‐triazole‐bridged bisphenol is thus among the most efficient organocatalysts that are active in the absence of both metal and halide. For alkyl‐substituted epoxides, good yields of 80–95 % were obtained under 1 bar CO2 in the presence of halide. The bisphenol was recycled 14 times in the presence of halide, and 5 times in the absence of halide. The two hydroxyl groups of bisphenol are proposed to work synergistically in the catalytic cycle.
Lanthanum‐Based Perovskites for Catalytic Oxygen Evolution Reaction
Authors: Dias Jeferson A. , Andrade Marcos A. S. , Santos Hugo L. S. , Morelli Márcio R. , Mascaro Lucia H. 
Published: May 2020

AbstractLanthanum‐based perovskites have been gaining attention in recent years as cost‐attractive and efficient catalysts for the oxygen evolution reaction (OER). Showing a simplified LaBO3 stoichiometry (B=transition metal cation), the structure and composition of the perovskites play key roles in their electrocatalytic performance. This paper aims to review the physicochemical concepts, structures, and recent advances on kinetic parameters for lanthanum‐based perovskites for catalytic OER. First, advances on mechanisms and descriptors that govern general perovskites will be discussed in detail. Next, the current results for lanthanum cobaltite (LaCoO3), nickelate (LaNiO3), ferrite (LaFeO3), manganite (LaMnO3), and their derivations will be provided. Moreover, the existing results on less explored lanthanum perovskites for catalytic OER (LaCrO3, LaCuO3, LaVO3, and LaTiO3) will be also presented. The impacts of structural defects, orbital occupancy, materials morphology, and composition on the perovskite electrocatalytic performance will be assessed for each case. Finally, emerging trends for lanthanum‐based perovskites will be provided.
A Tubular Electrochemical Reactor for Slurry Electrodes
Authors: Percin Korcan , Zoellner Oliver , Rall Deniz , Wessling Matthias 
Published: May 2020

AbstractThe research on electrochemical reactors is mostly limited to planarly designed modules. In this study, we compare a tubular and a planar electrochemical reactor for the utilization of the slurry electrodes. Cylindrical formed geometries demonstrate a higher surface‐to‐volume ratio, which may be favorable in terms of current density and volumetric power density. A tubular shaped electrochemical reactor is designed with conductive static mixers to promote the slurry particle mixing, and the vanadium redox flow battery is selected as a showcase application. The new tubular design presents similar cell resistances to the previously designed planar battery and shows increased discharge polarization behavior up to 100 mA cm−2. The volumetric power density reaches up to 30 mW cm−3, which is two times higher than that of the planar one. The battery performance is further investigated and 85 % coulombic, 70 % voltage and 60 % energy efficiency is found at 15 mA cm−2 with 15 wt.% slurry content.
Regioselective Intramolecular Allene Amidation Enabled by an EDA Complex**
Authors: Liu Lu , Ward Robert M. , Schomaker Jennifer M. 
Published: May 2020

AbstractThe addition of radicals to unsaturated precursors is a powerful tool for the synthesis of both carbo‐ and heterocyclic organic building blocks. The recent advent of mild ways to generate N‐centered radicals has reignited interest in exploiting highly regio‐, chemo‐, and stereoselective transformations that employ these reactive intermediates. While the additions of aminyl, iminyl, and amidyl radicals to alkenes and alkynes have been well‐studied, analogous additions to allenes are scarce. Allenes offer several attractive features, including potential for selective amidation at three distinct sites via judicious choice of precursor or radical source, the opportunity for axial‐to‐point chirality transfer, and productive trapping of vinyl or allyl radical intermediates to diversify functionality in the products. In this article, we report a regioselective addition of amidyl radicals to allenes to furnish an array of valuable N‐heterocycle scaffolds.
Randomized double‐blind cross‐over trial of bath additive containing tannic acid in patients with atopic dermatitis
Authors: Takahagi Shunsuke , Harada Naoe , Kamegashira Akiko , Suzuki Shigeru , Shindo Hajime , Kanatani Hirotoshi , Tanaka Akio , Mizuno Hayato , Hide Michihiro 
Published: May 2020

AbstractSkin care against aggravating factors is important to prevent skin lesions from flare‐up in the treatment of atopic dermatitis (AD). Tannic acid (TA), a natural polyphenolic and protein‐denaturing agent, has activity to denature antigens relevant to the AD flare. To assess the efficacy of a bath additive containing TA (TA‐bath additive) on pruritus of AD, we carried out a randomized double‐blind trial, in which 21 patients with AD completed the blinded sequential treatments with the TA‐bath additive and a bath additive without TA (placebo‐bath additive) in a cross‐over manner. A significant improvement of pruritus was observed in the afternoon and night by using the TA‐bath additive and in the afternoon by the placebo‐bath additive in patients with AD. No superiority of the TA‐bath additive to the placebo was revealed in the overall patient cohort. However, the added TA in the bath additive exerted its efficacy especially on itch at night in patients with mild‐to‐moderate disease. Bathing by using the series of the bath additive with TA and that without TA improved AD skin lesions throughout this study. No adverse effects related to the use of the TA‐ and placebo‐bath additives were observed. In conclusion, the bath additive containing TA may help skin care of patients with itch and skin lesions of the mild AD.
Rheology and processing of polytetrafluoroethylene (PTFE) paste
Authors: Tomkovic Tanja , Hatzikiriakos Savvas G. 
Published: May 2020

AbstractThis is a review article on the paste extrusion of polytetrafluoroethylene (PTFE). The article begins with an overall presentation of the process. Important aspects related to this process are the physical properties of PTFE, its rheology, the morphological changes occurring during flow (fibrillation) that play a critical role on the dimensional stability of the final products, the geometrical characteristics, and types of dies used and temperature. PTFE is a compressible, zero Poisson's ratio material, and the mechanical properties of extrudates after extrusion are also discussed in view of fibrillation and Poisson's ratio.
The use of student experiments in inclusive chemistry classes – chemistry teachers’ perspectives on chances and challenges
Authors: Pawlak Felix , Groß Katharina 
Published: May 2020

AbstractMit der gesetzlichen Verankerung der inklusiven Beschulung an allgemeinbildenden Schulen werden Chemielehrer*innen vor neue Herausforderungen im Unterricht gestellt. Die seit langem sowohl in der chemiedidaktischen Forschung als auch in der alltäglichen Schulpraxis anerkannte Entwicklungs‐, Lern‐ und Leistungsheterogenität von Schüler*innen tritt im Zuge der Inklusion verstärkt in den Mittelpunkt von (Chemie‐) Unterricht. Neben der Erforschung von angemessenen Lerngelegenheiten für Schüler*innen in einem inklusiven Chemieunterricht gilt es, die Lehrenden der inklusiven Praxis in den Blick zu nehmen, da diese die entscheidenden Akteure in der Umsetzung eines inklusiven Chemieunterrichts sind. Der vorliegende Beitrag stellt eine Untersuchung vor, in der die Sichtweisen von Chemielehrenden zum Einsatz von Schülerexperimenten im inklusiven Chemieunterricht erhoben werden. Dabei werden Chancen und Herausforderungen für die Umsetzung eines inklusiven experimentellen Chemieunterrichts deutlich, die zu entsprechenden Konsequenzen in der universitären Ausbildung angehender Chemielehrender führen.