bluuebunny/crossref_metadata_2025_split huggingface dataset:
Easy Access to Enantiomerically Pure Heterocyclic Silicon‐Chiral Phosphonium Cations and the Matched/Mismatched Case of Dihydrogen Release
Authors: Fontana Nicolò , Espinosa‐Jalapa Noel Angel , Seidl Michael , Bauer Jonathan O. 
Published: December 2020

AbstractPhosphonium ions are widely used in preparative organic synthesis and catalysis. The provision of new types of cations that contain both functional and chiral information is a major synthetic challenge and can open up new horizons in asymmetric cation‐directed and Lewis acid catalysis. We discovered an efficient methodology towards new Si‐chiral four‐membered CPSSi* heterocyclic cations. Three synthetic approaches are presented. The stereochemical sequence of anchimerically assisted cation formation with B(C6F5)3 and subsequent hydride addition was fully elucidated and proceeds with excellent preservation of the chiral information at the stereogenic silicon atom. Also the mechanism of dihydrogen release from a protonated hydrosilane was studied in detail by the help of Si‐centered chirality as stereochemical probe. Chemoselectivity switch (dihydrogen release vs. protodesilylation) can easily be achieved through slight modifications of the solvent. A matched/mismatched case was identified and the intermolecularity of this reaction supported by spectroscopic, kinetic, deuterium‐labeling experiments, and quantum chemical calculations.
Transition from Homochiral Clusters to Racemate Monolayers during 2D Crystallization of Trioxa[11]helicene on Ag(100)
Authors: Irziqat Bahaaeddin , Berger Jan , Mendieta‐Moreno Jesús I. , Sundar Mothuku Shyam , Bedekar Ashutosh V. , Ernst Karl‐Heinz 
Published: December 2020

AbstractThe phenomenon of chiral crystallization into homochiral crystals is known for more than 170 years, yet it is still poorly understood. Studying crystallization on surfaces under well‐defined condition seems a promising approach towards better understanding the intermolecular chiral recognition mechanisms during nucleation and growth. The two‐dimensional aggregation of racemic trioxaundecahelicene on the single crystalline silver(100) surface has been investigated with scanning tunneling microscopy and with non‐contact atomic force microscopy, as well as molecular modeling simulations. A transition from homochiral cluster motifs to heterochiral assembly into large islands with increasing coverage is observed. Force field modelling confirms higher stability of heterochiral arrangements from twelve molecules on. Results are discussed with respect to previous findings for the all‐carbon heptahelicene on the same surface.
Evaluating the bone‐regenerative role of the decellularized porcine bone xenograft in a canine extraction socket model
Authors: Chen Yuan‐Wu , Chen Meng‐Yen , Hsieh Dar‐Jen , Periasamy Srinivasan , Yen Ko‐Chung , Chuang Chao‐Tang , Wang Hung‐Chou , Tseng Fan‐Wei , Kuo Jer‐Cheng , Chien Hua‐Hong 
Published: December 2020

AbstractObjectiveTo evaluate the efficacy of a novel decellularized porcine bone xenograft, produced by supercritical carbon dioxide extraction technology, on alveolar socket healing after tooth extraction compared to a commercially available deproteinized bovine bone (Bio‐Oss®).Materials and methodsNine dogs (about 18 months old and weighing between 20 kg and 30 kg) underwent extractions of lower second to fourth premolars, bilaterally. The dogs were randomly selected and allocated to the following groups: Group 1: control unfilled socket; Group 2: socket filled with decellularized porcine bone xenograft (ABCcolla®) and covered by a commercially available porcine collagen membrane (Bio‐Gide®); Group 3: socket filled with Bio‐Oss® and covered by Bio‐Gide® membrane. One dogs from each group was sacrificed at 4‐, 12‐, and 24‐week to evaluate the socket healing after tooth extraction. The mandible bone blocks were processed without decalcification and specimens were embedded in methyl methacrylate and subjected to histopathology analyses to evaluate the bone regeneration in the extraction sockets.ResultsAt 24‐week after socket healing, ABCcolla® treated defects demonstrated significantly higher histopathology score in new bone formation and bone bridging, but significantly lower score in fluorescent labeling than those of the Bio‐Oss®. In the microphotographic examination, decellularized porcine bone xenograft showed similar characteristics of new bone formation to that of Bio‐Oss®. However, there was significantly less remnant implant materials in the decellularized porcine bone xenograft compared to the Bio‐Oss® group at 24‐week. Thus, the decellularized porcine bone graft seems to have promising bone regeneration properties similar to that of Bio‐Oss® with less remnant grafted material in a canine tooth extraction socket model.ConclusionsWithin the limits of the study, we concluded that ABCcolla® treated defects demonstrated significantly more new bone formation and better bone bridging, but less amount of fluorescent labeling than those of the Bio‐Oss® group. However, clinical studies in humans are recommended to confirm these findings.
Combinational therapy targeting the MET‐mTOR‐ROS loop disrupts mitochondrial autoregulatory machinery of liver cancer
Authors: Huang Xing , Zhang Gang , Bai Xueli , Liang Tingbo 
Published: December 2020

AbstractA wide variety of regulators have been identified in mechanistic target of rapamycin (mTOR) activation; however, the protective mechanisms of mTOR inactivation are still largely unknown, especially in tumor growth. Here, we have found the hepatocyte growth factor (HGF) receptor (MET) is required for mTOR activation‐stimulated mitochondrial oxidative phosphorylation (OXPHOS) in a phosphorylation‐dependent manner in liver cancer. Intriguingly, we observed mitochondrial quality dictates the regulatory effects of MET on mTOR and OXPHOS. Once overloaded, mitochondrial reactive oxygen species (ROS) inhibits mTOR activity and OXPHOS performance to prevent mitochondrial dysfunction‐induced tumor cell death, by disrupting MET dimerization to block its autophosphorylation and interaction with vacuolar ATP synthase (V‐ATPase). The MET‐mTOR‐ROS loop acts as a protective checkpoint in liver cancer, and thus this autoregulatory machinery is a promising combinational target for liver cancer therapy.
Electroactivated Disposable Pencil Graphite Electrode – New, Cost‐effective, and Sensitive Electrochemical Detection of Bioflavonoid Hesperidin
Authors: Šafranko Silvija , Stanković Anamarija , Asserghine Abdelilah , Jakovljević Martina , Hajra Sugato , Nundy Srijita , Medvidović‐Kosanović Martina , Jokić Stela 
Published: December 2020

AbstractIn this paper, for the first time, electroactivated disposable pencil graphite electrode (ePGE) was used for the detection of bioflavonoid hesperidin with cyclic and differential pulse voltammetry. The electroactivation efficiency of the pencil graphite electrode (PGE) was examined employing electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) and the enhancement of electron transfer kinetics of the PGE after the electroactivation was found. Hesperidin is irreversibly oxidized on the ePGE and its oxidation was the most pronounced at pH=5.0. Two electrode processes were detected, on one hand, a mixed diffusion and adsorption control was observed for the first electrode process. On the other hand, only diffusion control was observed in the second electrode process. Linear dependence between the peak current and the hesperidin concentration was obtained in the concentration range from 5×10−7 mol dm−3 to 1×10−5 mol dm−3 and the determined lower limit of detection (LOD) was 2×10−7 mol dm−3. Moreover, hesperidin in pharmaceutical formulation (containing active substance, hesperidin, and excipients) was quantified using ePGE. A good correlation was obtained between experimentally obtained hesperidin concentration by voltammetric analysis and concentration determined by standard HPLC technique (R2=0.9462).
The financial requirements of tech startups over its lifecycle in Bangalore: An analysis of why and how do they differ?
Authors: Singh Shivalik , Bala Subrahmanya M H 
Published: December 2020

AbstractIt is widely recognized by researchers, practitioners and policy makers that for a tech startup adequate financial capital is an essential resource in order to emerge, survive and grow over its lifecycle. However, there is a lack of understanding on what are the various needs for financing, what factors drive these needs and how do they vary over a startup's lifecycle. This study makes a key contribution to the literature by investigating the financial requirements for a tech startup and their determinants based on primary data gathered from 93 tech startups in Bangalore. Our findings suggest that, out of the three major categories of financial requirements, namely, Human Capital (HC), Research Capital (RC) and Social Capital (SC), financial requirements for HC and SC vary with a startup's lifecycle stage while financial requirement to acquire RC does not. With these results, we assert that, while all the three resources are essential, RC is the most critical financial requirement for a tech startup as it assumes predominance throughout a tech startup's lifecycle and acts as oxygen for its growth and sustainable competitive advantage.
Impact of irrigated agriculture on welfare of farm households in northern Ethiopia: panel data evidence*
Authors: Tesfay Menasbo Gebru 
Published: December 2020

AbstractThe purpose of this study was to assess the impact of participating in irrigated agriculture on the welfare of smallholders in the semi‐arid economy of northern Ethiopia. Two rounds of balanced panel data for the production seasons 2009/2010 and 2014/2015 collected from 407 smallholder farmers were analysed. Correlated random effect double hurdle models are used to estimate participation and extent of involvement in irrigated agriculture. The household fixed effect with a control function approach was used to assess the impact of participating in irrigated agriculture on welfare outcomes. The double hurdle model results indicate that households with at least one plot owned and located within the irrigation command area positively and significantly affect participation in irrigated agriculture. The fixed‐effect model results also revealed that the area planted with use of irrigation enables smallholders to grow crops more than once a year; to ensure increased and stable production, income, consumption and asset accumulation positively. The finding of this study confirms that the potential role of irrigated agriculture is not limited to improving crop income and consumption of rural households, but also higher production from irrigated agriculture generates surplus products and better chance to integrate with the output market.
Progress in research on effect of PM2.5 on occurrence and development of atherosclerosis
Authors: Tian Mengya , Zhao Jingbo , Mi Xingyan , Wang Kai , Kong Deling , Mao Hongjun , Wang Ting 
Published: December 2020

AbstractFine particulate matter ≤2.5 μm (PM2.5) air pollution is regarded as one of the prominent risk factors that contributes to morbidity and mortality globally, among which cardiovascular disease (CVD) has been strongly associated with PM2.5 exposure and is a leading cause of death. Atherosclerosis (AS), the common pathological basis of many CVDs, is a progressive syndrome characterized by the accumulation of lipids and fibrous plaque in the arteries. Recent epidemiological and toxicological studies suggest that PM2.5 may also contribute to the development of AS, even at levels below the current air quality standards. In this paper, the complete pathological process of atherosclerotic plaque from occurrence to rupture leading to CVD was elaborated. Then, the growing epidemiological evidence linking PM2.5 to AS in humans was reviewed and summarized. Furthermore, the potential mechanisms of PM2.5‐mediated AS were discussed, including oxidative stress, inflammation, endothelial dysfunction, abnormal lipid metabolism, disturbance of the autonomic nervous system, and abnormal coagulation function. This paper aimed to provide a comprehensive view of the effect of PM2.5 on the occurrence and development of AS for better prevention and mitigation of adverse health impacts due to PM2.5 air pollution.
Radiological evaluations of low cost wollastonite nano‐ceramics graft doped with iron oxide in the treatment of induced defects in canine mandible
Authors: Mabrouk Mostafa , Taha Said K. , Abdel Hamid Mohamed A. , Kenawy Sayed H. , Hassan Elham A. , El‐Bassyouni Gehan T. 
Published: December 2020

AbstractWollastonite with/without maghemite [(Fe2O3), 0, 3 and 10 wt%] was prepared by facile wet precipitation method. Effect of Fe2O3 presence in the obtained nano‐ceramics on physical structure, morphology, size and the mechanical features was evaluated using X‐ray diffraction, transmission electron microscope, and universal testing machine. Moreover, the in vitro biomineralization was examined using simulated body fluid (SBF) by means of scanning electron microscope/energy dispersive X‐ray, Fourier transform infrared, and inductively coupled plasma. An in vivo study was conducted on 24 adult male mongrel dogs to test the biosafety of fabricated samples in the reconstruction of experimentally induced mandibular bone defects. Bone density was measured through cone beam computed tomography analysis conducted at 1 and 3 months following surgery. Wollastonite was the main phase in all the prepared samples however little maghemite was developed in Fe‐containing samples. No remarkable changes were recognized for physical structure of obtained microcrystalline structures, however, a decrease in particle size was noted in the existence of Fe2O3 (10‐15 nm) when compared to the pure wollastonite (30–50 nm). Mechanical features were dependent on the included Fe2O3 concentration within the wollastonite ceramic matrix. The degree of biomineralization of the samples immersed in SBF was elevated with the increase in Fe2O3 percentage. Clinically, the reconstruction of bone defects was uneventful without any adverse toxic effect. Bone density was significantly increased at 1 and 3 months (p < .001) in grafted defects compared to control ones. Increasing the doping concentrations of iron oxide was associated with significant increase (p < .001) of bone density in all induced defects. Due to the impressive healing effect of current fabricated nano‐ceramics, they are recommended to be utilized as low cost bone graft alternatives.
On supersaturation and stability for generalized Turán problems
Authors: Halfpap Anastasia , Palmer Cory 
Published: December 2020

AbstractFix a graph . We say that a graph is ‐free if it contains no copy of as a subgraph. Let denote the maximum number of copies of a graph in an ‐vertex ‐free graph. In this note, we will give a new general supersaturation result for in the case when as well as a new proof of a stability theorem for .
Biological differentiation of traditional Chinese medicine from excessive to deficient syndromes in AIDS: Comparative microRNA microarray profiling and syndrome‐specific biomarker identification
Authors: Wan Tingjun , Liu Xiyang , Su Yue , Zou Jiaxi , Wu Xi , Jiang Cen , Cao Chunhui , Yao Mingyue , Zhou Yuyu , Rong Lijun , Li Baixue , Wen Li , Feng Quansheng 
Published: December 2020

AbstractTraditional Chinese medicine (TCM) has been widely applied as a supplementary therapy of human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) in China. TCM has a positive effect on improving the quality of life, prolonging life, and ameliorating the symptoms of HIV/AIDS patients. Yang deficiency of spleen and kidney (YDSK) syndrome is a typical deficient TCM syndrome in AIDS patients, and accumulation of heat‐toxicity (AHT) syndrome is a common excessive syndrome in the earlier stage of AIDS. Thus, accurate diagnosis of these two syndromes can improve the targeted treatment effect, and predict the prognosis of the disease. However, the scientific basis of TCM syndromes remains lacking, greatly hindering the accuracy of diagnosis and effectiveness of treatment. In this research, microRNA (miRNA) microarray and quantitative real‐time polymerase chain reaction combined with bioinformatics were used for comparative analysis between YDSK and AHT patients. Significantly differential expressed miRNAs (SDE‐miRNAs) of each TCM syndrome were identified, including hsa‐miR‐766‐3p and hsa‐miR‐1260a and so on, as well hsa‐miR‐6124, hsa‐let‐7g‐5p and so on, for YDSK and AHT, respectively. Biological differences were found between their SDE‐miRNAs based on bioinformatics analyses, for example, ErbB signaling pathway mainly linked to AHT, while focal adhesion dominated in YDSK. Syndrome‐specific SDE‐miRNAs were further identified as potential biomarkers, including hsa‐miR‐30e‐5p, hsa‐miR‐144‐5p for YDSK and hsa‐let‐7g‐5p, hsa‐miR‐126‐3p for AHT, respectively. All of them have laid biological and clinical bases for TCM diagnosis and treatment of AIDS syndrome at the miRNA level, offering potential diagnostic indicators of immune reconstitution.
Effect of ozone, lactic acid and combination treatments on the control of microbial and pesticide contaminants of fresh vegetables
Authors: Pounraj Saranya , Bhilwadikar Tanmayee , Manivannan Selladurai , Rastogi Navin K , Negi Pradeep S 
Published: December 2020

AbstractBACKGROUNDFruit and vegetable consumption has increased due to their tremendous health benefits. However, recent studies have shown that contaminated products may serve as vehicles for foodborne pathogens and harmful chemicals. Therefore, fresh vegetables must be decontaminated before consumption to ensure food safety.RESULTSIn this study, the combined decontamination treatment of lactic acid (2.5 mL L−1) and ozone (9 mg L−1) for 10 min showed better efficacy in the removal of contaminants from fresh vegetables as compared to individual treatments. The combined treatment resulted in a reduction of 1.5–3.5 log CFU of native mesophilic bacteria per gram and 1.6–2.9 log CFU of artificially inoculated Escherichia coli per gram from tomato, cucumber, carrot and lettuce. The combined treatment also removed spiked pesticides, which represent artificial chemical contamination (28–97% chlorpyrifos and 62–100% λ‐cyhalothrin residues), from fresh vegetables. No significant difference (P > 0.05) in various sensory attributes of vegetables was observed between untreated and treated (lactic acid and ozone) vegetables.CONCLUSIONSThe combination treatment provides a novel approach to target two groups of contaminants using a single procedure. The combination treatment can be used as an alternative to currently used decontamination techniques for the supply of safe vegetables to consumers. © 2020 Society of Chemical Industry
Quality control and long‐term stability study of ginger from different geographical origins using chemometrics
Authors: Abdo Mai T , El‐Ahmady Sherweit H , Gad Haidy A 
Published: December 2020

AbstractBACKGROUNDGinger rhizome (Zingiber officinale) is a well‐known spice and medicinal plant that is widely used in the Egyptian market as a spice, flavor and medicinal herb for different diseases. Since it is not cultivated as rhizomes in Egypt, ginger is imported from other countries, which may impact its quality. In this study, UV spectroscopy and high‐performance liquid chromatography (HPLC) were applied as efficient available techniques for the discrimination and quality control of ginger collected from different geographical origins in combination with chemometrics. In addition, HPLC was applied to investigate the stability of ginger samples upon storage for 3 years to trace the changes in their main active constituents.RESULTSData obtained from both UV and HPLC in combination with Principal Component Analysis (PCA) displayed proper discrimination of the samples according to their geographical origins. Regarding the stability study, ginger samples showed a significant decrease in quality after storage for 3 years, in which significant variation in the main pungent principles (6‐, 8‐, 10‐gingerols and 6‐shogaol) were observed. PCA failed to discriminate between ginger samples after long‐time storage, so the applied model could discriminate between ginger samples before and after storage.CONCLUSIONUV and HPLC in combination with chemometrics can be applied as a successful tool for the study of quality, stability and geographical discrimination of ginger. © 2020 Society of Chemical Industry
A strategy to comprehensively and quickly identify the chemical constituents in Platycodi Radix by ultra‐performance liquid chromatography coupled with traveling wave ion mobility quadrupole time‐of‐flight mass spectrometry
Authors: Gao Yang , Wu Yi , Liu Shu , Liu Zhiqiang , Song Fengrui , Liu Zhongying 
Published: December 2020

AbstractQuick identification of the complex composition of traditional Chinese medicine only through liquid‐mass spectrometry technology is difficult. Especially the identification of isomers and co‐eluting compounds is even more difficult. In this study, an approach of multidimensional data modes based on ultra‐performance liquid chromatography coupled with traveling wave ion mobility quadrupole time‐of‐flight mass spectrometry was proposed to quickly and comprehensively identify the compounds in Platycodi Radix. First, data‐independent acquisition, high‐definition acquisition, and tandem mass spectrometry acquisition modes were used to acquire integrated multidimensional mass spectral data. Second, summarize the diagnostic ions of compounds according to the fragmentation pathway of references. Third, unknown compounds and isomers were identified via the UNIFI™ software with an in‐house library. Finally, a total of 87 compounds were identified, seven compounds were explicitly identified by comparing the retention time and fragment ions with the references. Fourteen compounds were first detected in the Platycodi Radix, four of them tentatively were identified by comparing with previous literature, eight compounds were observed and reported for the first time by comparing typical fragmentation pathway with the known standard substances in this paper. This research strategy has a certain potential for the analysis of complex components of other traditional Chinese medicine.
From double‐atom catalysts to single‐cluster catalysts: A new frontier in heterogeneous catalysis
Authors: Liu Jin , Cao Dong , Xu Haoxiang , Cheng Daojian 
Published: December 2020

AbstractIn recent years, atomically dispersed metal catalysts with well‐defined structures have attracted great interest in heterogeneous catalysis due to their high atomic utilization efficiency, activity, stability, and selectivity. The rapid development of single‐atom catalysts (SACs) has simultaneously stimulated the emergence of diatomic catalysts (DACs) and single cluster catalysts (SCCs). Compared with SACs, DACs, and SCCs possess higher metal loading and more structurally flexible active sites, which provide great potential for achieving higher catalytic performance. DACs and SCCs have become a new field of heterogeneous catalysis. In this review, we first focus on the latest developments of DACs/SCCs, including synthesis methods and characterization approaches including experimental and theoretical tools. In addition, the relationship between structure and catalytic performance of DACs/SCCs are well discussed, including the effect of supports, synergistic metal atoms, and coordination environment. At last, the similarities and differences between SACs and DACs/SCCs are systematically summarized and analyzed.