bluuebunny/crossref_metadata_2025_split huggingface dataset:
Repeated prenatal corticosteroid administration delays astrocyte and capillary tight junction maturation in fetal sheep
Authors: Huang W.L. , Harper C.G. , Evans S.F. , Newnham J.P. , Dunlop S.A. 
Published: July 2002

AbstractGlucocorticoids are powerful regulators of cell differentiation and maturation. Their synthetic counterparts, the corticosteroids, are used widely in obstetric practice to enhance fetal lung maturation in cases of threatened preterm birth. Here we examined the effects of repeated corticosteroid administration on astrocyte and capillary tight junction development in the fetal sheep brain, selecting the corpus callosum for analysis. Pregnant ewes were given saline or betamethasone (0.5 mg/kg) at 104, 111, 118 and 124 days gestation. Lambs were delivered at term, terminally anaesthetized and transcardially perfused. Transverse semi‐thin sections of the corpus callosum were cut and immuno‐stained with antibody against glial fibrillary acidic protein (GFAP). Ultra‐thin sections were examined in the electron microscope. The percentage area of GFAP staining was reduced in the corticosteroid‐treated group compared to control (5.2 vs. 8.7%, P<0.05). The expression of GFAP in peri‐capillary and parenchymal astrocytes was also reduced compared to control (peri‐capillary: 3.0 vs. 9.5 μm2; parenchymal: 14.6 vs. 29.4 μm2, P<0.05). Furthermore, capillary tight junction maturation was delayed compared to control. Immature ‘type II’ junctions were more common in the corticosteroid‐treated group (63 vs. 22%, P<0.05), whereas more mature ‘type III’ junctions were less common (27 vs. 65%, P<0.05). Our data suggest that repeated corticosteroids delay both astrocyte and capillary tight junction maturation. The implications for clinical practice are as yet unknown.
A regression analytical approach to estimate the onset of activity of antidepressants
Authors: Müller H , Möller H-J 
Published: July 2002

SummaryThe onset of activity of antidepressants is a clinically and theoretically important criterion of efficacy. We estimated the onset of activity by an intraindividual regression analytical approach. It is assumed that efficient treatment causes a fast shift of depression scores from a baseline level to an end level. From this assumption follows a limited number of opportunities for the onset of activity to occur. These opportunities correspond to different regression models which are estimated for each patient's depression course. The day of onset is concluded from the regression model which produces the best fit to the empirical depression curve. Results of a double-blind clinical trial comparing mianserin and amitriptyline are reported (n = 28). The methodological approach confirms that observer ratings by physicists show a significantly earlier onset of activity than self ratings by the patients. The D-S also shows a significantly earlier onset of activity of mianserin compared to amitriptyline. The discussion emphasises methodological aspects.
Month of birth in deficit and non-deficit schizophrenic patients
Authors: Dollfus S. , Brazo P. , Langlois S. , Gourevitch R. , Dassa D. , Besse F. , Van Der Elst A. , Thibaut F. , Delamillieure P. , Chabot B. , Guelfi J.D. , Petit M. 
Published: July 2002

SummaryIn order to test the hypothesis that an excess of summer births is a risk factor for deficit syndrome, the month of birth was studied in 53 deficit schizophrenic patients compared to 158 non-deficit patients. No significant difference in terms of month of birth or season of birth was observed between deficit and non-deficit patients, suggesting that summer births might not be a risk factor for deficit schizophrenia.
Alterations in DNA methylation profiles in cancellous bone of postmenopausal women with osteoporosis
Authors: Zhou Yu , Yang Ling , Wang Hong , Chen Xi , Jiang Wei , Wang Zhicong , Liu Shuping , Liu Yuehong 
Published: June 2020

Osteoporosis is characterized by systemic microarchitecture impairment and bone loss, which ultimately lead to fragility fractures. This disease is most common in older people, especially in postmenopausal women. Cancellous bone is affected by osteoporosis earlier than cortical bone, and DNA methylation microarray analysis of the hip cancellous bone of patients with osteoarthritis revealed differential methylation. In view of the important role of cancellous bone in bone development, we examined genome‐wide DNA methylation profiles in the cancellous bone from patients with postmenopausal osteoporosis versus healthy postmenopausal women using Illumina 850K methylation microarray analysis. Under a threshold of P < 0.05, we obtained a total of 8973 differentially methylated genes, such as SOX6, ACE, SYK and TGFB3. Under a threshold of P < 0.05 and |△β| > 0.2, a total of 17 and 34 key differentially methylated genes were further identified at the promoter region and cytosine‐ phosphate‐ guanine (CpG) islands (such as PRKCZ, GNA11 and COL4A1), respectively. PLEKHA2, PLEKHB1, PNPLA7, SCD, MGST3 and TSNAX were the most common differentially methylated genes at both the promoter region and CpG islands. Five important signaling pathways, including the calcium signaling pathway, the cyclic guanosine phospho‐protein kinase G (cGMP‐PKG) signaling pathway, endocytosis, the Rap1 signaling pathway and the AMPK signaling pathway were identified. Our study may be suitable as a basis for exploring the mechanisms underlying osteoporosis in postmenopausal women.
Inductively Coupled Plasma Mass Spectrometry Analysis of Environmental Samples for the Quantification of Potentially Toxic Species
Authors: Teuma‐Castelletti Robert , Sadiq Nausheen W. , Beauchemin Diane 
Published: June 2020

AbstractThe analysis of environmental samples is widely carried out to determine if a soil is safe for agricultural use, if water is safe to drink, if the air that we breathe can make us sick, how far reaching is pollution, if a contaminated site has been suitably remediated, etc. This article discusses how inductively coupled plasma mass spectrometry (ICPMS) can be used to this end. Indeed, with detection limits at the parts per trillion or even parts per quadrillion level, depending on the element and the instrument, ICPMS is very advantageous for the detection and quantification of toxic or potentially toxic species in environmental samples. This article describes sample preparation for ICPMS analysis and instrument calibration to yield accurate quantitative results. This includes the precautions that are often required, which vary depending on the type of analysis, sample matrix, instrument, and elements to be determined. It also includes techniques that can be coupled to ICPMS to increase its capabilities, such as laser ablation or electrothermal vaporization for direct solid analysis and liquid chromatography, gas chromatography, or capillary electrophoresis for speciation analysis, as speciation information is lost in the inductively coupled plasma (ICP) where all compounds are atomized.
Monitoring of Dynamic Processes during Detection of Cardiac Biomarkers Using Silicon Nanowire Field‐Effect Transistors
Authors: Li Jie , Kutovyi Yurii , Zadorozhnyi Ihor , Boichuk Nazarii , Vitusevich Svetlana 
Published: June 2020

AbstractNumerous sensitive nanobiosensors are reported for various bioassay applications as a result of the development of materials science and nanotechnology. Among these sensors, nanowire (NW) field‐effect transistors (FETs) represent one of the most promising practical biosensors for ultrasensitive clinical diagnostic tools. Most studies mainly focus on how to achieve a lower detection limit but pay less attention to the long settling time effect for the detection of very small concentrations of molecules in a solution. In this study, single silicon NW FETs with long‐term stability is fabricated to investigate the settling time process at small concentrations of cardiac biomarkers relevant to myocardial diseases. It is found that the settling time strongly depends on the type of molecule, its charge state and analyte concentrations. For low concentrations, the time for measurement signals to settle down is relatively long. Therefore, it is essential to understand the settling time effect in Si NW FET‐based biosensing processes to ensure the accuracy and reliability of the detection signal. An alternative approach is demonstrated to circumvent the long measurement time by utilizing reaction kinetics parameters for the fast determination of low‐concentration detection, which also benefits the optimal balance between suitable detection time and reliable detection results.
Bromination of α‐Diazo Phenylacetate Derivatives Using Cobalt(II) Bromide
Authors: Wang Haifeng , Sun Xiangli , Hu Manman , Zhang Xiaoyi , Xie Lele , Gu Shuangxi 
Published: June 2020

AbstractA method for the bromination of α‐diazo phenylacetate derivatives using cobalt(II) bromide is described. This bromination reaction features a short reaction time, broad substrate scope, operational simplicity, acid‐free conditions, and gram‐scalability.magnified image
High‐Throughput Analysis of Materials for Chemical Looping Processes
Authors: Singstock Nicholas R. , Bartel Christopher J. , Holder Aaron M. , Musgrave Charles B. 
Published: June 2020

AbstractChemical looping is a promising approach for improving the energy efficiency of many industrial chemical processes. However, a major limitation of modern chemical looping technologies is the lack of suitable active materials to mediate the involved subreactions. Identification of suitable materials has been historically limited by the scarcity of high‐temperature (>600 °C) thermochemical data to evaluate candidate materials. An accuratethermodynamic approach is demonstrated here to rapidly identify active materials which is applicable to a wide variety of chemical looping chemistries. Application of this analysis to chemical looping combustion correctly classifies 17/17 experimentally studied redox materials by their viability and identifies over 1300 promising yet previously unstudied active materials. This approach is further demonstrated by analyzing redox pairs for mediating a novel chemical looping process for producing pure SO2 from raw sulfur and air which could provide a more efficient and lower emission route to sulfuric acid. 12 promising redox materials for this process are identified, two of which are supported by previous experimental studies of their individual oxidation and reduction reactions. This approach provides the necessary foundation for connecting process design with high‐throughput material discovery to accelerate the innovation and development of a wide range of chemical looping technologies.
Performance of double cropping silage maize with plastic mulch in the North China Plain
Authors: Liang Shuoshuo , Zhang Xiying , Lu Yang , An Ping , Yan Zongzheng , Chen Suying 
Published: June 2020

AbstractNorth China Plain farmers often use maize (Zea mays L.) silage for dairy cows. Double cropping of maize may be a feasible way to reduce annual water use and land required to produce feed. The objective of this study was to evaluate the possibility of growing a double crop of silage maize with and without plastic film mulch. An experiment was conducted between 2015 and 2018 and contained three treatments: double‐cropped (maize) plastic film mulch (2 M+PM), double‐cropped (maize) without plastic film mulch (2 M), and double‐cropped winter wheat (Triticum aestivum L.) and summer maize (WW+SM). Net income, yield, water use efficiency (WUE), and annual water use were determined. The results indicated that silage dry matter yield and WUE were improved by 45.6 and 31.5%, respectively, using plastic film mulch compared with no mulch. Total water footprint in producing the silage was also reduced by 24% using plastic film mulch. The annual water use was reduced by 150–190 mm with 2 M+PM or 2 M compared with WW+SM. Average net income was 429, 926, and 1,008 $ ha−1 in 2 M, 2 M+PM, and WW+SM, respectively. The results indicated that the advantages of the double‐silage maize system lie in the reduction in the amount of land required to produce maize silage for dairy cows. However, due to the limited growth duration for the double maize, high silage water contents reduced silage quality.
Subspecies differentiation in an enigmatic chaparral shrub species
Authors: Huang Yi , Morrison Glen R. , Brelsford Alan , Franklin Janet , Jolles Diana D. , Keeley Jon E. , Parker V. Thomas , Saavedra Natalie , Sanders Andrew C. , Stoughton Thomas R. , Wahlert Gregory A. , Litt Amy 
Published: June 2020

PremiseDelimiting biodiversity units is difficult in organisms in which differentiation is obscured by hybridization, plasticity, and other factors that blur phenotypic boundaries. Such work is more complicated when the focal units are subspecies, the definition of which has not been broadly explored in the era of modern genetic methods. Eastwood manzanita (Arctostaphylos glandulosaEastw.) is a widely distributed and morphologically complex chaparral shrub species with much subspecific variation, which has proven challenging to categorize. Currently 10 subspecies are recognized, however, many of them are not geographically segregated, and morphological intermediates are common. Subspecies delimitation is of particular importance in this species because two of the subspecies are rare. The goal of this study was to apply an evolutionary definition of “subspecies” to characterize structure within Eastwood manzanita.MethodsWe used publicly available geospatial environmental data and reduced‐representation genome sequencing to characterize environmental and genetic differentiation among subspecies. In addition, we tested whether subspecies could be differentiated by environmentally associated genetic variation.ResultsOur analyses do not show genetic differentiation among subspecies of Eastwood manzanita, with the exception of one of the two rare subspecies. In addition, our environmental analyses did not show ecological differentiation, though limitations of the analysis prevent strong conclusions.ConclusionsGenetic structure within Eastwood manzanita does not correspond to current subspecies circumscriptions, but rather reflects geographic distribution. Our study suggests that subspecies concepts need to be reconsidered in long‐lived plant species, especially in the age of next‐generation sequencing.
Use of Research Evidence Generated by Youth: Conceptualization and Applications in Diverse U.S. K‐12 Educational Settings
Authors: Ozer Emily J. , Abraczinskas Michelle , Voight Adam , Kirshner Ben , Cohen Alison K. , Zion Shelley , Glende Jillian R. , Stickney Dane , Gauna Reyes , Lopez Solicia E. , Freiburger Keegan 
Published: June 2020

AbstractYouth‐Led Participatory Action Research (YPAR) is a social justice‐focused approach for promoting social change and positive youth development in which youth conduct systematic research and actions to improve their schools and communities. Although YPAR is oriented to generating research for action, with evidence‐based recommendations often aimed at influencing adults with power over settings and systems that shape youths’ lives, we have little understanding of how YPAR evidence influences the thinking and/or actions of adult policymakers or practitioners. In general, the participatory research field lacks a theoretically informed “use of research evidence” lens, while the use of evidence field lacks consideration of the special case and implications of participatory research. To start to address these gaps, this paper presents a conceptual linkage across these two fields and then provides six illustrative case examples across diverse geographic, policy, and programmatic contexts to demonstrate opportunities and challenges in the use of YPAR evidence for policy and practice. Our illustrative focus here is on U.S. K‐12 educational contexts, the most‐studied setting in the YPAR literature, but questions examined here are relevant to YPAR and other systems domestically and internationally, including health, educational, and legal systems.Highlights

The use of research evidence (URE) field identifies characteristics of research and conditions that strengthen URE.

Youth‐led Participatory Action Research is a special case for factors that influence research use.

Six case examples across diverse K‐12 contexts illustrate facilitators and barriers for YPAR use.

We propose next steps for community psychology research and action to promote the study and use of YPAR evidence.
Should we be concerned about COVID‐19 with nonhuman primates?
Authors: Santos Wesley José , Guiraldi Lívia Maísa , Lucheis Simone Baldini 
Published: June 2020

AbstractThe coronavirus disease 2019 pandemic has radically changed the human activities worldwide. Although we are still learning about the disease, it is necessary that primatologists, veterinarians, and all that are living with nonhuman primates (NHP) be concerned about the probable health impacts as these animals face this new pandemic. We want to increase discussion with the scientific community that is directly involved with these animals, because preliminary studies report that NHP may become infected and develop symptoms similar to those in human beings.
A Single‐Atom Manipulation Approach for Synthesis of Atomically Mixed Nanoalloys as Efficient Catalysts
Authors: Zhou Xuan , Li Kai , Lin Yunxiang , Song Li , Liu Jincheng , Liu Yu , Zhang Lingling , Wu Zhijian , Song Shuyan , Li Jun , Zhang Hongjie 
Published: June 2020

AbstractSynthesis of well‐defined atomically mixed alloy nanoparticles on desired substrates is an ultimate goal for their practical application. Herein we report a general approach for preparing atomically mixed AuPt, AuPd, PtPd, AuPtPd NAs(nanoalloys) through single‐atom level manipulation. By utilizing the ubiquitous tendency of aggregation of single atoms into nanoparticles at elevated temperatures, we have synthesized nanoalloys on a solid solvent with CeO2 as a carrier and transition‐metal single atoms as an intermediate state. The supported nanoalloys/CeO2 with ultra‐low noble metal content (containing 0.2 wt % Au and 0.2 wt % Pt) exhibit enhanced catalytic performance towards complete CO oxidation at room temperature and remarkable thermostability. This work provides a general strategy for facile and rapid synthesis of well‐defined atomically mixed nanoalloys that can be applied for a range of emerging techniques.
Hierarchically Structured Allotropes of Phosphorus from Data‐Driven Exploration
Authors: Deringer Volker L. , Pickard Chris J. , Proserpio Davide M. 
Published: June 2020

AbstractThe discovery of materials is increasingly guided by quantum‐mechanical crystal‐structure prediction, but the structural complexity in bulk and nanoscale materials remains a bottleneck. Here we demonstrate how data‐driven approaches can vastly accelerate the search for complex structures, combining a machine‐learning (ML) model for the potential‐energy surface with efficient, fragment‐based searching. We use the characteristic building units observed in Hittorf's and fibrous phosphorus to seed stochastic (“random”) structure searches over hundreds of thousands of runs. Our study identifies a family of hierarchically structured allotropes based on a P8 cage as principal building unit, including one‐dimensional (1D) single and double helix structures, nanowires, and two‐dimensional (2D) phosphorene allotropes with square‐lattice and kagome topologies. These findings yield new insight into the intriguingly diverse structural chemistry of phosphorus, and they provide an example for how ML methods may, in the long run, be expected to accelerate the discovery of hierarchical nanostructures.
Deuteriodifluoromethylation and gem‐Difluoroalkenylation of Aldehydes Using ClCF2H in Continuous Flow
Authors: Fu Wai Chung , Jamison Timothy F. 
Published: June 2020

AbstractThe deuteriodifluoromethyl group (CF2D) represents a challenging functional group due to difficult deuterium incorporation and unavailability of precursor reagents. Herein, we report the use of chlorodifluoromethane (ClCF2H) gas in the continuous flow deuteriodifluoromethylation and gem‐difluoroalkenylation of aldehydes. Mechanistic studies revealed that the difluorinated oxaphosphetane (OPA) intermediate can proceed via alkaline hydrolysis in the presence of D2O to provide α‐deuteriodifluoromethylated benzyl alcohols or undergo a retro [2+2] cycloaddition under thermal conditions to provide the gem‐difluoroalkenylated product.
A Mixed‐Valence {Fe13} Cluster Exhibiting Metal‐to‐Metal Charge‐Transfer‐Switched Spin Crossover
Authors: Wen Wen , Meng Yin‐Shan , Jiao Cheng‐Qi , Liu Qiang , Zhu Hai‐Lang , Li Ya‐Ming , Oshio Hiroki , Liu Tao 
Published: June 2020

AbstractIt is promising and challenging to manipulate the electronic structures and functions of materials utilizing both metal‐to‐metal charge transfer (MMCT) and spin‐crossover (SCO) to tune the valence and spin states of metal ions. Herein, a metallocyanate building block is used to link with a FeII‐triazole moiety and generates a mixed‐valence complex {[(Tp4‐Me)FeIII(CN)3]9[FeII4(trz‐ph)6]}⋅[Ph3PMe]2⋅[(Tp4‐Me)FeIII(CN)3] (1; trz‐ph=4‐phenyl‐4H‐1,2,4‐triazole). Moreover, MMCT occurs between FeIII and one of the FeII sites after heat treatment, resulting in the generation of a new phase, {[(Tp4‐Me)FeII(CN)3][(Tp4‐Me)FeIII(CN)3]8 [FeIIIFeII3(trz‐ph)6]}⋅ [Ph3PMe]2⋅[(Tp4‐Me)FeIII(CN)3] (1 a). Structural and magnetic studies reveal that MMCT can tune the two‐step SCO behavior of 1 into one‐step SCO behavior of 1 a. Our work demonstrates that the integration of MMCT and SCO can provide a new alternative for manipulating functional spin‐transition materials with accessible multi‐electronic states.
Synthesis of a Stable N‐Hetero‐RhI‐Metallacyclic Silanone
Authors: Takahashi Shintaro , Nakaya Kazuki , Frutos María , Baceiredo Antoine , Saffon‐Merceron Nathalie , Massou Stéphane , Nakata Norio , Hashizume Daisuke , Branchadell Vicenç , Kato Tsuyoshi 
Published: June 2020

AbstractA novel N‐hetero‐RhI‐metallacyclic silanone 2 has been synthesized. The silanone 2, showing an extremely large dimerization energy (ΔG=+86.2 kcal mol−1), displays considerable stability and persists in solution up to 60 °C. Above 120 °C, an intramolecular Csp3−H insertion occurs slowly over a period of two weeks leading to the bicyclic silanol 5. The exceptional stability of 2, related to the unusual electronic and steric effects of RhI‐substituent, should allow for a more profound study and understanding of these new species. Furthermore, the metallacyclic silanone 2 presents two reactive centers (Si=O and Rh), which can be involved depending upon the nature of reagents. Of particular interest, the reaction with H2 starts with the hydrogenation of RhI center leading to the corresponding RhIII‐dihydride complex 7 and it undergoes a cis/trans‐isomerization via a particular mechanism, demonstrating that addition‐elimination processes can also happen for silanones just like for their carbon analogues!