bluuebunny/crossref_metadata_2025_split huggingface dataset:
Iridium‐Catalyzed Reductive Coupling of Grignard Reagents and Tertiary Amides
Authors: Gabriel Pablo , Xie Lan‐Gui , Dixon* Darren J. 
Published: April 2020

Abstract
This article describes the procedure for iridium‐catalyzed reductive coupling of grignard reagents and tertiary amides. It presents some of the important points to be considered, the conditions that need to be maintained, characterization data, and the reagents required, as well as the techniques used and the equipment setup that are vital to carrying out the process. The article also describes the hazards associated with N,Ndimethylbenzamide, carbonylchlorobis(triphenylphosphine)iridium (I), dichloromethane, 1,1,3,3‐tetramethyldisiloxane, ethylmagnesium bromide (3.0 M in diethyl ether), diethyl ether, hydrochloric acid in dioxane (4.0 M), ethyl acetate, and methanol. The mild, yet highly active and chemoselective catalytic system formed from Vaska's complex and 1,1,3,3‐tetramethyldisiloxane allows reductive coupling of Grignard reagents to amides in an efficient fashion. This reaction offers a new strategy for the efficient and scalable synthesis of tertiary a‐branched amines including application in late‐stage functionalization.
Synthesis of 8‐Hydroxygeraniol
Authors: Ippoliti Francesca M. , Barber Joyann S. , Garg* Neil K. 
Published: April 2020

Abstract
This article describes the procedure for synthesis of 8‐hydroxygeraniol, which is a key biosynthetic precursor to all monoterpene indole alkaloids (MIAs). It presents some of the important points to be considered, the conditions that need to be maintained, characterization data, and the reagents required, as well as the techniques used and the equipment setup that are vital to carrying out the process. The article also describes the hazards associated with working with chemicals and the ways to deal with these hazards. The notorious poison strychnine is just one example of an MIA that arises biosynthetically from strictosidine. Other examples including medicinally important compounds such as the anti‐cancer agent vinblastine, the antimalarial medicine quinine, and ajmalicine, used to treat high blood pressure. Two reports were disclosed in 1970, which involved the use of either levulinaldehyde or dehydrolinalool to prepare 8‐hydroxygeraniol through multistep synthetic sequences.
Cytochrome P450 metabolism mediates low‐temperature resistance in pinewood nematode
Authors: Wang Bowen , Hao Xin , Xu Jiayao , Wang Buyong , Ma Wei , Liu Xuefeng , Ma Ling 
Published: April 2020

Pinewood nematode (PWN; Bursaphelenchus xylophilus) is a devastating invasive species that is expanding into colder regions. Here, we investigated the molecular mechanisms underlying low‐temperature resistance of PWN. We identified differentially expressed genes enriched under low temperature in previously published transcriptome data using the Kyoto Encyclopedia of Genes and Genomes. Quantitative real‐time PCR was used to further validate the transcript level changes of three known cytochrome P450 genes under low temperature. RNA interference was used to validate the low‐temperature resistance function of three cytochrome P450 genes from PWN. We report that differentially expressed genes were significantly enriched in two cytochrome P450‐related pathways under low‐temperature treatment. Heatmap visualization of transcript levels of cytochrome P450‐related genes revealed widely different transcript patterns between PWNs treated under low and regular temperatures. Transcript levels of three cytochrome P450 genes from PWNs were elevated at low temperature, and knockdown of these genes decreased the survival rates of PWNs under low temperature. In summary, these findings suggest that cytochrome P450 metabolism plays a critical role in the low‐temperature resistance mechanism of PWN.
Amyloid‐Like Protein Aggregates: A New Class of Bioinspired Materials Merging an Interfacial Anchor with Antifouling
Authors: Hu Xinyi , Tian Juanhua , Li Chen , Su Hao , Qin Rongrong , Wang Yifan , Cao Xin , Yang Peng 
Published: April 2020

AbstractSurfaces that resist nonspecific protein adsorption in a complex biological milieu are required for a variety of applications. However, few strategies can achieve a robust antifouling coating on a surface in an easy and reliable way, regardless of material type, morphology, and shape. Herein, the preparation of an antifouling coating by one‐step aqueous supramolecular assembly of bovine serum albumin (BSA) is reported. Based on fast amyloid‐like protein aggregation through the rapid reduction of the intramolecular disulfide bonds of BSA by tris(2‐carboxyethyl)phosphine, a dense proteinaceous nanofilm with controllable thickness (≈130 nm) can be covered on virtually arbitrary material surfaces in tens of minutes by a simple dipping or spraying. The nanofilm shows strong stability and adhesion with the underlying substrate, exhibiting excellent resistance to the nonspecific adsorption of a broad‐spectrum of contaminants including proteins, serum, cell lysate, cells, and microbes, etc. In vitro and in vivo experiments show that the nanofilm can prevent the adhesion of microorganisms and the formation of biofilm. Compared with native BSA, the proteinaceous nanofilm coating exposes a variety of functional groups on the surface, which have more‐stable adhesion with the surface and can maintain the antifouling in harsh conditions including under ultrasound, surfactants, organic solvents, and enzymatic digestion.
Influence of Pore Space Hierarchy on the Efficiency of an Acetylcholinesterase‐Based Support for Biosensorics
Authors: Kohns Richard , Anders Nicole , Enke Dirk , Tallarek Ulrich 
Published: April 2020

AbstractThe influence of a hierarchically structured pore system of a silica sol–gel support for application as a functional component in an acetylcholinesterase‐based enzyme array, with respect to its efficiency (response time, in particular) is investigated. Careful adjustment of synthesis parameters and a novel drying method allow to prepare monolithic silica sol–gel membranes with monomodal or hierarchical pore structures. These supports enable direct comparison regarding the influence of morphological properties on maximum acetylcholinesterase (AChE) loading by a membrane and on the apparent reaction rate of the AChE‐catalyzed degradation of acetylcholine at identical enzyme loading. It is shown for the first time that the hierarchical, meso‐macroporous material is superior over the monomodal structures (of either mesopores or macropores) regarding combined functionality and transport efficiency, as reflected in the apparent reaction rates. The advantage of the mesopores in a hierarchical system is manifested in higher maximum enzyme loading than for purely macroporous material, while the presence of macropores results in less obstructed transport that for a purely mesoporous material, which in turn reduces the response time.
Surface Amorphization of Vanadium Dioxide (B) for K‐Ion Battery
Authors: Li Youpeng , Zhang Qiaobao , Yuan Yifei , Liu Haodong , Yang Chenghao , Lin Zhang , Lu Jun 
Published: April 2020

AbstractGiven the merits of low cost, fast ionic transport in electrolyte, and high operating voltage, potassium ion batteries (PIBs) are promising alternatives to lithium‐ion batteries. However, developing suitable electrode materials that can reversibly accommodate large potassium ions is a great challenge. Here, guided by density functional theory (DFT) calculations, it is demonstrated that the strategy of interfacial engineering via surface amorphization of VO2 (B) nanorods (SA‐VO2), which results in the formation of a crystalline core/amorphous shell heterostructure, enables superior K+ storage performance in terms of large capacity, outstanding rate capability, and long cycle stability working as an anode for PIBs. DFT calculations reveal that the created crystalline/amorphous heterointerface in SA‐VO2 can substantially lower the surface energy, narrow the band gap, and reduce the K+ diffusion barrier of VO2 (B). These conditions enable enhanced K+ storage capacity and rapid K+/electron transfer, which result in large capacity and outstanding rate capability. Using in situ X‐ray diffraction and in situ transmission electron microscopy complemented by ex situ microscopic and spectroscopic techniques, it is unveiled that the superior cycling stability originates from the excellent phase reversibility with negligible strain response and robust mechanical behavior of SA‐VO2 upon (de)potassiation.
Low one‐repetition‐maximum knee extension is significantly associated with poor grip strength, female sex, and various aging‐related syndromes
Authors: Singhal Sunny , Bansal Rishav , Dewangan Gevesh Chand , Upadhyay Ashish Datt , Dwivedi Sada Nand , Chatterjee Prashun , Chakrawarty Avinash , Dey Aparajit Ballav 
Published: April 2020

AbstractObjectiveMuscle strength in older adults is usually measured according to grip strength, which demonstrates upper muscle strength only. In this study, we used one‐repetition‐maximum (1‐RM) knee extension as a measure of lower limb strength and assessed its relationship with grip strength and various geriatric syndromes.MethodsOne hundred outpatients over the age of 65 years were recruited from a geriatric medicine center in India. The 1‐RM knee extension was measured along with grip strength. Various geriatric conditions were measured, such as: nutrition (using the Mini Nutritional Assessment), cognition (Hindi Mental State Questionnaire), depression (5‐item Geriatric Depression Scale), frailty (Fried and Rockwood models), and osteoporosis (dual‐energy X‐ray absorptiometry scan). Sarcopenia was diagnosed using the Asian Working Group for Sarcopenia criteria.ResultsThe mean age of participants was 72.5 years with 69% of them male. Median values of 1‐RM knee extension and grip strength were 2.29 (0.5‐10.0) and 17.5 (0‐78), respectively. The 1‐RM knee extension had moderate correlation with grip strength (r = 0.491, P < 0.001). Among demographic details, only female sex (P < 0.001) was significantly associated with lower 1‐RM values. Further, after adjusting for age and sex, lower value of log10 1‐RM knee extension was found to be significantly associated with malnutrition (P = 0.001), dementia (P = 0.016), depression (P = 0.047), frailty (Rockwood: P = 0.049; Fried: P = 0.011), and sarcopenia (P < 0.001).ConclusionThe 1‐RM knee extension has only moderate correlation with grip strength. A lower 1‐RM knee extension value is significantly associated with female sex and various geriatric conditions, such as malnutrition, dementia, depression, frailty, and sarcopenia.
COVID‐19: Infection prevention and control guidance for all ultrasound practitioners
Authors: Basseal Jocelyne M. , Westerway Susan Campbell , McAuley Terry 
Published: April 2020

AbstractThe severe acute respiratory syndrome coronavirus (SARS‐CoV‐2), an enveloped virus, is the causative agent of the disease known as COVID‐19 (coronavirus disease‐2019). Proper infection prevention and control measures and good hygiene practices are essential to prevent spread of COVID‐19 and protect both patients and the healthcare worker. These guidelines are relevant to all ultrasound practitioners and provides guidance on cleaning and disinfection of ultrasound equipment, the environment and PPE (protective personal equipment) during the COVID‐19 outbreak in the Australasian region.
Possible Link between the Distribution of Atomic Spectral Lines and the Radiation–Matter‐Equilibrium in the Early Universe
Authors: Richardt Tim , Heinrich Matthias , Gräfe Markus , Szameit Alexander 
Published: April 2020

AbstractThe uncanny resemblance of the global distribution of all experimentally known atomic spectral lines to the Planckian spectral distribution associated with black body radiation at a temperature of is reported. This value coincides with the critical temperature of equilibrium between the respective densities of radiation and matter in the early universe.
An E1‐Catalyzed Chemoenzymatic Strategy to Isopeptide‐N‐Ethylated Deubiquitylase‐Resistant Ubiquitin Probes
Authors: Zheng Qingyun , Wang Tian , Chu Guo‐Chao , Zuo Chong , Zhao Rui , Sui Xin , Ye Linzhi , Yu Yuanyuan , Chen Jingnan , Wu Xiangwei , Zhang Wenhao , Deng Haiteng , Shi Jing , Pan Man , Li Yi‐Ming , Liu Lei 
Published: April 2020

AbstractTriazole‐based deubiquitylase (DUB)‐resistant ubiquitin (Ub) probes have recently emerged as effective tools for the discovery of Ub chain‐specific interactors in proteomic studies, but their structural diversity is limited. A new family of DUB‐resistant Ub probes is reported based on isopeptide‐N‐ethylated dimeric or polymeric Ub chains, which can be efficiently prepared by a one‐pot, ubiquitin‐activating enzyme (E1)‐catalyzed condensation reaction of recombinant Ub precursors to give various homotypic and even branched Ub probes at multi‐milligram scale. Proteomic studies using label‐free quantitative (LFQ) MS indicated that the isopeptide‐N‐ethylated Ub probes may complement the triazole‐based probes in the study of Ub interactome. Our study highlights the utility of modern protein synthetic chemistry to develop structurally and new families of tool molecules needed for proteomic studies.
Evaluation methods for portfolio management
Authors: Law Keith K. F. , Li W. K. , Yu Philip L. H. 
Published: April 2020

AbstractWe distinguish the evaluation methods for two main kinds of investment strategies, namely, passive and active portfolio management. Passive portfolio management aims at tracking an underlying index as close as possible with the most important measure being the tracking error. To claim the tracking error not exceeding a certain threshold, we apply the concept of noninferiority test as opposed to the common malpractice of one‐sided test, which tries to accept the null hypothesis when there is insufficient evidence to reject it. In contrast, the normal one‐sided test should be adopted in active portfolio management, which requires another crucial statistic, the information ratio, of an active portfolio to exceed the underlying benchmark in a risk adjusted sense. The asymptotic variances of the tracking error and the difference between two information ratios are derived, which allow proper evaluation and comparison of strategies within the passive and active portfolio management frameworks.
Unsupervised classification of the intrinsic and morphological properties of quasars through self‐organizing maps
Authors: Karafistan Aysel , Gemikonakli Eser 
Published: April 2020

AbstractThe aim of this paper is to unveil, by means of self‐organizing maps (SOMs), the connections between intrinsic properties of radio quasars, namely redshift (z), luminosity (P), continuum slope (α), and parameters characterizing radio morphology of the host galaxy: observed linear size and bending. The strong luminosity–redshift correlation established by a prior traditional principal component analysis (PCA) is confirmed for the same dataset that contains 36 nearby (z < 1.5) and 44 distant (z > 1.5) quasars with five parameters. The SOM visualizations disentangled the luminosity–linear size anti‐correlation, supporting a dimensionality of p = 2 for the quasar parameter space. The SOM also clustered radio quasars into subgroups with common physical properties. We expect this work to provide a new probe, leading to further clustering of nonlabeled data with respect to the evolution of morphological properties.
Direct enantioseparation of mandelic acid by high‐performance liquid chromatography using a phenyl column precoated with a small amount of cyclodextrin additive in a mobile phase
Authors: Watanabe Yuri , Mikami Ikko , Yamamoto Atsushi , Aizawa Sen‐ichi , Taga Atsushi , Mochizuki Naoki , Ishihara Yoshimi , Kodama Shuji 
Published: April 2020

AbstractDirect enantioseparation of mandelic acid by high‐performance liquid chromatography (HPLC) with a reversed phase column and a mobile phase containing a small amount of hydroxylpropyl‐β‐cyclodextrin (HP‐β‐CD) was studied as an efficient method for saving consumption of the CD additive. As a result, it was proposed that racemic mandelic acid can be analyzed with a phenyl column by using a mobile phase composed of 10 mM ammonium acetate buffer (pH 4.2) and 0.02% (w/v) HP‐β‐CD at a flow rate of 1.0 mL/min at 40°C after the passage of 10 mM ammonium acetate buffer (pH 4.2) containing 0.1% (w/v) HP‐β‐CD as a precoating mobile phase for 60 min. It is suggested that HP‐β‐CD is bound with a phenyl group on the surface of the stationary phase to allow a phenyl column to act as a transient chiral column, and injected mandelic acid can form the ternary complex with the adsorbed HP‐β‐CD. The longer retention time of D‐mandelic acid than the L‐isomer for HPLC can be explained from the higher stability of the HP‐β‐CD complex with D‐mandelic acid, which was confirmed by CE experiment with HP‐β‐CD as a selector. The efficiency of a phenyl column compared with other stationary phases was also discussed.
Image quality assessment by an efficient correlation‐based metric
Authors: Lin Li‐Hui , Chen Tzong‐Jer 
Published: April 2020

SummaryImage quality can be measured visually. In the human visual system, a compressed image can be judged by the human eye. Image quality may not be perceived to decline in a region with low compression. However, image quality clearly declines in a region with high compression. As image compression increases, image quality gradually transitions from visually lossless to lossy. In this study, we aim to explain this phenomenon. A few images from different datasets were selected and compressed using JJ2000 and Apollo, which are well‐known image compression algorithms. Then, error‐based and correlation‐based metrics were applied to these images. The correlation‐based metrics agree with human‐vision evaluations in experiments, but the error‐based metrics do not. Inspired by the positive result of the correlation‐based metrics, a new metric named the simple correlation factor (SCF) was proposed to explain the aforementioned phenomenon. The results of the SCF show good consistency with human‐vision results for several datasets. In addition, the computation efficiency of the SCF is better than that of the existing correlation‐based metrics.
Additive‐Free Conversion of Internal Alkynes by Phosphanylalumanes: Production of Phosphorus/Aluminum Frustrated Lewis Pairs
Authors: Yanagisawa Tatsuya , Mizuhata Yoshiyuki , Tokitoh Norihiro 
Published: April 2020

AbstractInternal and terminal alkynes react with phosphanylalumanes, i. e., P−Al single‐bond species, through heating but without any additional additives. The reactions with internal alkynes afforded the corresponding adducts with cis‐1,2‐form in moderate yields (54–80 %). In addition, alkyne adducts thus obtained function as P/Al‐based C2‐vicinal FLPs, and the FLP addition reactions with benzaldehyde and CO2 were demonstrated. Furthermore, in the reaction of 2,4,6‐trimethylphenyl‐substituted alkyne adducts with dimethyl acetylenedicarboxylate, an unexpected CAr−CMe bond cleavage characteristic of this system was demonstrated.
Lupus erythematosus cell in body fluids: A case report and review of literature
Authors: Ningombam Aparna , Sarkar Abhirup , Acharya Shreyam , Chopra Anita 
Published: April 2020

AbstractThe diagnosis of systemic lupus erythematosus (SLE) has undergone radical change after the development of serological techniques. The in vitro demonstration of lupus erythematosus (LE) cell has less significance for the diagnosis of SLE in the present scenario. Although over the years, the spontaneous in vivo occurrence of LE cell in numerous body fluids as an initial presentation of SLE has been documented. The report of the presence of the LE cell can not only aid in the further workup of the patient but also suggest the involvement of a particular organ or body cavities by SLE. The morphology and mimickers of the LE cell should be cogitated and meticulous search of such cells should play an important role in the evaluation of body fluids. In our case, the patient presented at emergency with pericardial tamponade and cytological evaluation of the pericardial fluid demonstrated in vivo presence of LE cells. The serological work‐up then confirmed the case to be SLE. This report and review of literature wish to highlight the fact that this cell still plays a significant role even in the era of immunoassays.
Quantifying drought’s influence on moist soil seed vegetation in California’s Central Valley through remote sensing
Authors: Byrd Kristin B. , Lorenz Austen A. , Anderson James A. , Wallace Cynthia S. A. , Moore‐O’Leary Kara A. , Isola Jennifer , Ortega Ricardo , Reiter Matthew E. 
Published: April 2020

AbstractCalifornia’s Central Valley, USA is a critical component of the Pacific Flyway despite loss of more than 90% of its wetlands. Moist soil seed (MSS) wetland plants are now produced by mimicking seasonal flooding in managed wetlands to provide an essential food resource for waterfowl. Managers need MSS plant area and productivity estimates to support waterfowl conservation, yet this remains unknown at the landscape scale. Also the effects of recent drought on MSS plants have not been quantified. We generated Landsat‐derived estimates of extents and productivity (seed yield or its proxy, the green chlorophyll index) of major MSS plants including watergrass (Echinochloa crusgalli) and smartweed (Polygonumspp.) (WGSW), and swamp timothy (Crypsis schoenoides) (ST) in all Central Valley managed wetlands from 2007 to 2017. We tested the effects of water year, land ownership and region on plant area and productivity with a multifactor nested analysis of variance. For the San Joaquin Valley, we explored the association between water year and water supply, and we developed metrics to support management decisions. MSS plant area maps were based on a support vector machine classification of Landsat phenology metrics (2017 map overall accuracy: 89%). ST productivity maps were created with a linear regression model of seed yield (n = 68,R2 = 0.53, normalized RMSE = 10.5%). The Central Valley‐wide estimated area for ST in 2017 was 32,369 ha (29,845–34,893 ha 95% CI), and 13,012 ha (11,628–14,396 ha) for WGSW. Mean ST seed yield ranged from 577 kg/ha in the Delta Basin to 365 kg/ha in the San Joaquin Basin. WGSW area and ST seed yield decreased while ST area increased in critical drought years compared to normal water years (Scheffe’s test,P < 0.05). Greatest ST area increases occurred in the Sacramento Valley (~75%). Voluntary water deliveries increased in normal water years, and ST seed yield increased with water supply.Zscores of ST seed yield can be used to evaluate wetland performance and aid resource allocation decisions. Updated maps will support habitat monitoring, conservation planning and water management in future years, which are likely to face greater uncertainty in water availability with climate change.