bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphine‐oxide‐catalyzed Enantioselective Cross‐aldol Reactions of Aldehydes with Trichlorosilane as Lewis Acid Promoter
Authors: Kotani Shunsuke , Hanamure Takuya , Mori Yoshiki , Nakajima Makoto 
Published: July 2020

AbstractA hypervalent silicon complex between trichlorosilane and a chiral phosphine oxide acts as an effective Lewis acid mediator that successfully promotes highly enantioselective cross‐aldol reactions between two aldehydes. The high yielding transformation is realized with the assistance of triisobutylamine, which does not decompose trichlorosilane but rather converts the aldol donor into the silyl enol ether that undergoes the enantioselective cross‐aldol reaction with a second aldehyde in combination with the chiral phosphine oxide catalyst.
Ru/CdS Quantum Dots Templated on Clay Nanotubes as Visible‐Light‐Active Photocatalysts: Optimization of S/Cd Ratio and Ru Content
Authors: Stavitskaya Anna V. , Kozlova Ekaterina A. , Kurenkova Anna Yu. , Glotov Aleksandr P. , Selischev Dmitry S. , Ivanov Evgenii V. , Kozlov Denis V. , Vinokurov Vladimir A. , Fakhrullin Rawil F. , Lvov Yuri M. 
Published: July 2020

AbstractA nanoarchitectural approach based on in situ formation of quantum dots (QDs) within/outside clay nanotubes was developed. Efficient and stable photocatalysts active under visible light were achieved with ruthenium‐doped cadmium sulfide QDs templated on the surface of azine‐modified halloysite nanotubes. The catalytic activity was tested in the hydrogen evolution reaction in aqueous electrolyte solutions under visible light. Ru doping enhanced the photocatalytic activity of CdS QDs thanks to better light absorption and electron–hole pair separation due to formation of a metal/semiconductor heterojunction. The S/Cd ratio was the major factor for the formation of stable nanoparticles on the surface of the azine‐modified clay. A quantum yield of 9.3 % was reached by using Ru/CdS/halloysite containing 5.2 wt % of Cd doped with 0.1 wt % of Ru and an S/Cd ratio of unity. In vivo and in vitro studies on the CdS/halloysite hybrid demonstrated the absence of toxic effects in eukaryotic cells and nematodes in short‐term tests, and thus they are promising photosensitive materials for multiple applications.
Recent Advances in Heterogeneous Catalytic Systems Containing Metal Ions for Phosphate Ester Hydrolysis
Authors: Gomes Marco Antônio G. B. , Fernandes Christiane , Gahan Lawrence R. , Schenk Gerhard , Horn Adolfo 
Published: July 2020

AbstractOrganophosphates are a class of organic compounds that are important for living organisms, forming the building blocks for DNA, RNA, and some essential cofactors. Furthermore, non‐natural organophosphates are widely used in industrial applications, including as pesticides; in laundry detergents; and, unfortunately, as chemical weapons agents. In some cases, the natural degradation of organophosphates can take thousands of years; this longevity creates problems associated with handling and the storage of waste generated by such phosphate esters, in particular. Efforts to develop new catalysts for the cleavage of phosphate esters have progressed in recent decades, mainly in the area of homogeneous catalysis. In contrast, the development of heterogeneous catalysts for the hydrolysis of organophosphates has not been as prominent. Herein, examples of heterogeneous systems are described and the importance of the development of heterogeneous catalysts applicable to organophosphate hydrolysis is highlighted, shedding light on recent advances related to different solid matrices that have been employed.
Conservation of ultrafast photoprotective mechanisms with increasing molecular complexity in sinapoyl malate derivatives
Authors: Baker Lewis A. , Staniforth Michael , Flourat Amandine L. , Allais Florent , Stavros Vasilios G. 
Published: July 2020

AbstractSinapoyl malate is a natural plant sunscreen molecule which protects leaves from harmful ultraviolet radiation. Here, the ultrafast dynamics of three sinapoyl malate derivatives, sinapoyl L‐dimethyl malate, sinapoyl L‐diethyl malate and sinapoyl L‐di‐t‐butyl malate, have been studied using transient electronic absorption spectroscopy, in a dioxane and methanol solvent environment to investigate how well preserved these dynamics remain with increasing molecular complexity. In all cases it was found that, upon photoexcitation, deactivation occurs via a trans‐cis isomerisation pathway within ∼20–30 ps. This cis‐photoproduct, formed during photodeactivation, is stable and longed‐lived for all molecules in both solvents. The incredible levels of conservation of the isomerisation pathway with increased molecular complexity demonstrate the efficacy of these molecules as ultraviolet photoprotectors, even in strongly perturbing solvents. As such, we suggest these molecules might be well‐suited for augmentations to further improve their photoprotective efficacy or chemical compatibility with other components of sunscreen mixtures, whilst conserving their underlying photodynamic properties.
Corynebacterium diphtheriae Virulence Analyses Using a Caenorhabditis elegans Model
Authors: Chen Yi‐Wei , Ton‐That Hung 
Published: July 2020

AbstractCorynebacterium diphtheriae is the leading cause of pharyngeal diphtheria, a respiratory disease characterized by formation of a pseudomembrane at the site of infection. Although outbreaks of C. diphtheriae infections are rare nowadays, the emergence of multidrug‐resistant C. diphtheriae strains is one of the most significant public health concerns worldwide. Although C. diphtheriae has been studied for more than a century and diphtheria toxin and pili have been identified as major virulence factors, little is known about factors involved in bacterial colonization and development of disease. Here, we describe the utilization of Caenorhabditis elegans as a cost‐effective, versatile model of infection to evaluate C. diphtheriae virulence. We provide detailed protocols for nematode synchronization and for evaluation of nematode survival and formation of a deformed anal region induced by C. diphtheriae infection. These protocols will permit future high‐throughput screenings of virulence factors in C. diphtheriae and advance our knowledge of C. diphtheriae pathogenesis. © 2020 Wiley Periodicals LLC.Basic Protocol 1: Synchronization of nematodesBasic Protocol 2: Assay for nematode survival following C. diphtheriae infectionBasic Protocol 3: Assays for bacterial colonization and formation of deformed anal region
Photon Upconverting Solid Films with Improved Efficiency for Endowing Perovskite Solar Cells with Near‐Infrared Sensitivity
Authors: Kinoshita Mika , Sasaki Yoichi , Amemori Shogo , Harada Naoyuki , Hu Zhanhao , Liu Zonghao , Ono Luis K. , Qi Yabing , Yanai Nobuhiro , Kimizuka Nobuo 
Published: July 2020

AbstractPerovskite solar cells have emerged as the next‐generation high‐efficiency solar cell, but their absorption is mostly limited to the visible (vis) range. One possible solution is to integrate near‐infrared (NIR)‐to‐vis photon upconversion (UC). Herein, we show the first example of endowing perovskite solar cells with NIR sensitivity by using solid films showing NIR‐to‐vis UC based on triplet‐triplet annihilation (TTA). A high TTA‐UC efficiency of 4.1±0.3 % at an excitation intensity of 125 W/cm2 is achieved by sensitizing a rubrene (acceptor) triplet with an osmium (Os) complex donor having singlet‐to‐triplet (S−T) absorption in the NIR range, and by increasing the fluorescence quantum yield through energy harvesting to a highly fluorescent collector. In particular, our spectroscopic studies indicate that the upconverted acceptor singlet energy is almost selectively transferred to the collector rather than being quenched by the donor. By attaching the TTA‐UC film behind a semi‐transparent perovskite solar cell, a photocurrent generation is observed under excitation at 938 nm.
Doping control analysis of total arsenic in equine plasma
Authors: Chan George H.M. , Tang Wenlu , Curl Peter , Lin Yuanyuan , Wan Terence S.M. , Ho Emmie N.M. 
Published: July 2020

AbstractArsenic can be easily found in our surrounding environment. Because of its ubiquitous nature, horse urine and blood invariably contain low levels of arsenic. Nevertheless, inorganic arsenic, despite its general use as a tonic for horses, is an effective doping agent having a deleterious effect because of its ability to induce gastroenteritis. The misuse of arsenic in horseracing has been controlled by an international urinary threshold of total arsenic at 0.3 μg/mL. However, an equivalent threshold for total arsenic in plasma is yet to be established. In this study, an inductively coupled plasma‐mass spectrometry method has been developed for quantifying total arsenic in equine plasma. Statistical analysis determined that the data from a population study of 1,552 post‐race and out‐of‐competition plasma samples fits a Gaussian mixture model with two Gaussian components. A rounded‐up provisional threshold for plasma total arsenic at 2.5 ng/mL was subsequently established. Results from administration trials with a sodium arsanilate‐containing supplement showed that both urinary and plasma arsenic was significantly elevated after administration. The maximum urinary detection time was around 22 h based on the international threshold. However, the maximum plasma detection time would be longer than 73 h if the provisional threshold of 2.5 ng/mL was adopted. In view of the high discrepancy between the urine and plasma detection times, a revised plasma threshold of 15 ng/mL is proposed to afford a comparable detection time in both matrices. The risk of a normal sample exceeding the proposed plasma total arsenic threshold is practically zero.
Extreme drought and adaptive resource selection by a desert mammal
Authors: Gedir Jay V. , Cain James W. , Swetnam Tyson L. , Krausman Paul R. , Morgart John R. 
Published: July 2020

AbstractWhen animals select areas to occupy, decisions involve trade‐offs between the fitness benefits of obtaining critical resources and minimizing costs of biotic and abiotic factors that constrain their use. These processes can be more dynamic and complex for species inhabiting desert environments, where highly variable spatial and temporal distribution of precipitation can create high intra‐ and inter‐annual variability in forage conditions and water availability, and thermal constraints can differ significantly among seasons and diel periods. We examined resource selection in desert bighorn sheep (Ovis canadensis mexicana) in Cabeza Prieta National Wildlife Refuge, Arizona, USA, at multiple spatial and temporal scales to gain insight into how a desert mammal responds to variations in climatic conditions. We used resource selection functions to test topographic, forage, and environmental features among seasons and diel periods, and between non‐drought and drought conditions at the population and home‐range scale. When precipitation was average, sheep selected for topographic features that were beneficial for predator avoidance (i.e., escape terrain—steep, rugged areas with high visibility) and locations near perennial water. When drought occurred, they ranged further from preferred escape terrain and perennial water, perhaps seeking forage conditions suitable to meet their nutritional requirements. On early (April–June) and late (July–September) summer days, sheep selected for more northerly aspects and locations with lower solar radiation, and in some periods, selection for these cooler areas coincided with periods when forage covariates, proximity to perennial water, and several topographic features were uninformative in resource selection models. These choices may be necessary trade‐offs, foregoing good escape terrain and foraging areas, and access to water, for improved thermoregulation. This study highlights the importance of identifying resource selection at variable spatial and temporal scales when investigating the interrelationship between species and their environment. It provides insight into the dynamics of resource selection in desert mammals, and how they respond to constraints imposed on them by their environment. This work can serve to inform strategies for managing and conserving species living in arid environments when faced with climate change.
Windows of opportunity for salt marsh establishment: the importance for salt marsh restoration in the Yangtze Estuary
Authors: Yuan Lin , Chen Ya‐Hui , Wang Heng , Cao Hao‐Bing , Zhao Zhi‐Yuan , Tang Chen‐Dong , Zhang Li‐Quan 
Published: July 2020

AbstractRestoration has been promoted as an important strategy to reverse the decline of salt marsh ecosystems. Physical and biological processes limiting the colonization of bare tidal flats by pioneer salt marsh species are commonly recognized. Recently, the window of opportunity (WoO) concept has been proposed as a framework to provide an explanation for the initial establishment of biogeomorphic ecosystems on tidal flats under high physical stress. Understanding the thresholds for early seedling establishment and colonization is critical for the successful restoration and management of this threatened ecosystem. In this study, we investigated the WoOs for the establishment and colonization of a Scirpus mariqueter salt marsh at a large‐scale restoration site in the Yangtze Estuary. A set of field monitoring and measurements were conducted to identify the potential physical and biological thresholds that could provide a mechanistic insight on the establishment and colonization of this pioneer marsh. The results showed that the successful colonization and expansion of the S. mariqueter marsh on the tidal flat required passing both physical and biological thresholds to open WoOs for establishment and colonization. The concurrence of WoOs, that is, propagule availability in the early growing season at a suitable tidal flat elevation with a benign sedimentary regime together with the removal of competition from invasive species, is presumed to be essential for the success of S. mariqueter marsh establishment and colonization. In applying such ecological insights, the seed‐sowing field experiment proved that by surpassing these thresholds, an S. mariqueter salt marsh can be successfully restored in a cost‐effective manner. We suggest that these WoO‐related establishment and colonization thresholds as well the cost‐effectiveness of using these WoOs should be considered in future large‐scale restorations of salt marshes.
Effect of brewing conditions using a single‐serve coffee maker on black tea (Lapsang Souchong) quality
Authors: Ma Chunhua , Hung Yen‐Con 
Published: July 2020

AbstractBlack tea powder was used to make tea infusion using a Keuring coffee maker. Effect of tea particle size (0.30 or 0.60 mm), water volume for brewing (118, 177, or 236 ml), and the amount of tea powder (1.0, 1.5, or 2.0 g) on tea infusion quality were evaluated. The concentration of four chemical compounds (soluble sugars, total amino acids, polyphenols, and caffeine) in tea infusion was measured. In general, the concentration of the four compounds in tea infusion increased with the amount of tea powder used and decreased with increasing water volume and tea particle size. Using 2.0 g of 0.30 mm tea powder and 118 ml of water per brew, the concentration of the above four components was 412.3, 251.6, 208.9, and 205.3 μg/ml, respectively, and higher than tea infusion prepared by traditional method (312.4, 204.1, 211.6, and 175.9 μg/ml). The highest extraction efficiency (mg/cup.g) for the four chemical components per unit weight of tea powder was at using 1.0 g of 0.30 mm tea powder with 236 ml water for soluble sugars (32.3 μg/ml) and caffeine (16.3 μg/ml), at using 1.5 g tea powders for polyphenols (22.3 μg/ml) and at using 2.0 g tea powders for amino acid (13.6 μg/ml). This study suggested using a single‐serve coffee maker can be a convenient and effective way to prepare the tea infusion with high quality.
The effect of different starter cultures on biogenic amines and quality of fermented mutton sausages stored at 4 and 20°C temperatures
Authors: Sun Xueying , Du Bao , Zhao Lihua , Jin Ye , Su Lin , Tian Jianjun , Wu Jing 
Published: July 2020

AbstractThe biogenic amines (BAs), water activity, pH, thiobarbituric acid‐reactive substances (TBARS), and nitrite were, respectively, tested in dry fermented sausage with starter cultures (37x‐6 Lactobacillus plantarum, x3‐3b L. plantarum, 30x‐11 Staphylococcus pentosans, and 37x‐8 S. pentosans), during storage of room temperature (20°C) and refrigeration storage (4°C). Tryptamine (TRM), 2‐phenylethylamine (PHE), putrescine (PUT), cadaverine (CAD), histamine (HIM), and tyramine (TYM) contents of all samples were increased storage at 20°C, and the content of TRM, PUT, CAD, and HIM of all samples storage at 20°C was higher than that storage at 4°C after 42 days. The content of BA with 37x‐6, x3‐3b, and 37x‐8 was obviously decreased at 4°C storage. The storage temperature has a significant effect on BA content (p < .05) for TYM and other BAs tested. Finally, x3‐3b, 37x‐6, and 37x‐8 should be used to produce fermented sausages on the basis of the concentration of BAs.
Quality and timing of crowd‐based water level class observations
Authors: Etter Simon , Strobl Barbara , van Meerveld Ilja , Seibert Jan 
Published: July 2020

AbstractCrowd‐based hydrological observations can supplement existing monitoring networks and allow data collection in regions where otherwise no data would be available. In the citizen science project CrowdWater, repeated water level observations using a virtual staff gauge approach result in time series of water level classes (WL‐classes). To investigate the quality of these observations, we compared the WL‐class data with “real” (i.e., measured) water levels from the same stream at a nearby gauging station. We did this for nine locations where citizen scientists reported multiple observations using a smartphone app and at 12 locations where signposts were set up to ask citizens to record observations on a paper form that could be left in a letterbox. The results indicate that the quality of the data collected with the app was better than for the forms. A possible explanation is that for each app location, a single person submitted the vast majority of the observations, whereas at the locations of the forms almost every observation was made by a different person. On average, there were more contributions between May and September than during the other months. Observations were submitted for a range of flow conditions, with a higher fraction of high flow observations for the locations were data were collected with the app. Overall, the results are encouraging for citizen science approaches in hydrology and demonstrate that the smartphone application and the virtual staff gauge are a promising approach for crowd‐based water level class observations.
A novel mesenchymal‐associated transcriptomic signature for risk‐stratification and therapeutic response prediction in colorectal cancer
Authors: Matsuyama Takatoshi , Kandimalla Raju , Ishikawa Toshiaki , Takahashi Naoki , Yamada Yasuhide , Yasuno Masamichi , Kinugasa Yusuke , Hansen Torben Frøstrup , Fakih Marwan , Uetake Hiroyuki , Győrffy Balázs , Goel Ajay 
Published: July 2020

AbstractRisk stratification in Stage II and III colorectal cancer (CRC) patients is critical, as it allows patient selection for adjuvant chemotherapy. In view of the inadequacy of current clinicopathological features for risk‐stratification, we undertook a systematic and comprehensive biomarker discovery effort to develop a risk‐assessment signature in CRC patients. The biomarker discovery phase examined 853 CRC patients, and identified a gene signature for predicting recurrence‐free survival (RFS). This signature was validated in a meta‐analysis of 1212 patients from nine independent datasets, and its performance was compared against established prognostic signatures and consensus molecular subtypes (CMS). In addition, a risk‐prediction model was trained (n = 142), and subsequently validated in an independent clinical cohort (n = 286). As a result, this mesenchymal‐associated transcriptomic signature (MATS) identified high‐risk CRC patients with poor RFS in the discovery (hazard ratio [HR]: 1.79), and nine validation cohorts (HR: 1.86). In multivariate analysis, MATS was the most significant predictor of RFS compared to established prognostic signatures and CMS subtypes. Intriguingly, MATS robustly identified CMS4‐subtype in multiple CRC cohorts (AUC = 0.92‐0.99). In the two clinical cohorts, MATS stratified low and high‐risk groups with a 5‐year RFS in the training (HR: 4.11) and validation cohorts (HR: 2.55), as well as predicted response to adjuvant therapy in Stage II and III CRC patients. We report a novel prognostic and predictive biomarker signature in CRC, which is superior to currently used approaches and have the potential for clinical translation in near future.
Dietary fatty acids and colorectal cancer risk in men: A report from the Shanghai Men's Health Study and a meta‐analysis
Authors: Nguyen Sang , Li Honglan , Yu Danxia , Cai Hui , Gao Jing , Gao Yutang , Luu Hung N. , Tran Huong , Xiang Yong‐Bing , Zheng Wei , Shu Xiao‐Ou 
Published: July 2020

AbstractEvidence from animal models suggests that dietary fatty acids have both anticancer and tumor‐promoting effects. Whether dietary fatty acids are associated with colorectal cancer (CRC) in humans remains inconclusive. We investigated associations between dietary fatty acids and risk of CRC among 59 986 men who participated in the Shanghai Men's Health Study (SMHS), an ongoing population‐based prospective cohort study. We identified 876 incident CRC cases in the SMHS during a mean follow‐up of 9.8 years. Associations between dietary fatty acid intake and CRC risk were evaluated by Cox proportional hazard regression analyses. Consumption of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) was not significantly associated with CRC risk. Multivariate hazard ratios (HRs) and respective 95% confidence intervals (CIs) for Quartile 4 vs Quartile 1 were 0.92 (0.74‐1.14; Ptrend = 0.47) for SFA, 0.95 (0.79‐1.16; Ptrend = 0.74) for MUFA and 1.18 (0.95‐1.46; Ptrend = 0.21) for PUFA. No significant associations were found for total n‐6 PUFA or total n‐3 PUFA. Additionally, we performed a meta‐analysis to summarize results from the present study and 28 reports from 26 additional cohorts, which supported the overall null association between dietary fatty acid intake and CRC risk among men. Docosahexanoic acid and eicosapentaenoic acid were associated with 11% to 12% reduced risk, and linoleic acid a 19% increased risk, of CRC in the meta‐analysis of combined sexes. In conclusion, this population‐based prospective study and meta‐analysis of cohort studies found little evidence that dietary fatty acid intake was associated with risk of CRC in men.
A review on the physiological and pathophysiological role of endothelial glycocalyx
Authors: Liu Huan‐qiu , Li Ji , Xuan Cheng‐luan , Ma Hai‐chun 
Published: July 2020

AbstractThe glycocalyx is a gel‐like layer covering the luminal surface of vascular endothelial cells. It comprises of membrane‐attached proteoglycans, glycosaminoglycan chains, glycoproteins, and adherent plasma proteins. The glycocalyx maintains homeostasis of the vasculature, which includes controlling vascular permeability and microvascular tone, preventing microvascular thrombosis, and regulating leukocyte adhesion. In the past decades, the number of studies on endothelial glycocalyx has steadily grown. Glycocalyx emerged as an essential part of blood vessels involved in multiple physiological functions. Damage to glycocalyx is associated with many types of diseases. The structure and physiology and pathophysiology of the glycocalyx, as well as the clinical effects of glycocalyx degradation, are addressed throughout this study. We strive in particular to define therapeutic approaches for the survival or reparation of the glycocalyx.