293 research outputs found
1,2-Bis(4-ethynylphenyl)disulfane
In the title compound, C16H10S2, the S atoms are almost coplanar with the benzene rings to which they are bonded [deviations of 0.092 (1) and 0.022 (1) Å from their respective ring planes]. The benzene rings enclose a dihedral angle of 79.17 (3)°. An intramolecular C—H⋯S hydrogen bond results in the formation of a five-membered ring. In the crystal structure, molecules are stacked parallel to the a axis direction. π–π interactions between benzene rings are present, with a face-to-face stacking distance of 3.622 (10) Å
(E)-1-Ferrocenyl-3-(3-nitrophenyl)prop-2-en-1-one
In the title compound, [Fe(C5H5)(C14H10NO3)], one cyclopentadiene ring is substituted and one is unsubstituted. The two rings are almost parallel and are eclipsed and ordered. The conjugated substituent is slightly twisted with respect to the cyclopentadiene ring. The crystal structure contains four intermolecular C—H⋯O hydrogen-bonds in the range 3.324 (3)–3.539 (3) Å and one π(aryl ring)–π (Cp ring) stacking interaction with a ring–centroid distance of 3.894 (2) Å
Microbial diversity drives carbon use efficiency in a model soil
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Domeignoz-Horta, L. A., Pold, G., Liu, X. A., Frey, S. D., Melillo, J. M., & DeAngelis, K. M. Microbial diversity drives carbon use efficiency in a model soil. Nature Communications, 11(1), (2020): 3684, doi:10.1038/s41467-020-17502-z.Empirical evidence for the response of soil carbon cycling to the combined effects of warming, drought and diversity loss is scarce. Microbial carbon use efficiency (CUE) plays a central role in regulating the flow of carbon through soil, yet how biotic and abiotic factors interact to drive it remains unclear. Here, we combine distinct community inocula (a biotic factor) with different temperature and moisture conditions (abiotic factors) to manipulate microbial diversity and community structure within a model soil. While community composition and diversity are the strongest predictors of CUE, abiotic factors modulated the relationship between diversity and CUE, with CUE being positively correlated with bacterial diversity only under high moisture. Altogether these results indicate that the diversity × ecosystem-function relationship can be impaired under non-favorable conditions in soils, and that to understand changes in soil C cycling we need to account for the multiple facets of global changes.Funding for this project was provided by the Department of Energy grant DE-SC0016590 to K.M.D. and S.D.F., and an American Association of University Women Dissertation fellowship to G.P. We would also like to thank Stuart Grandy and Kevin Geyer for the fruitful discussions and Mary Waters, Courtney Bly and Ana Horta for their help with samples processing
Calcium-sensing receptor regulates stomatal closure through hydrogen peroxide and nitric oxide in response to extracellular calcium in Arabidopsis
The Arabidopsis calcium-sensing receptor CAS is a crucial regulator of extracellular calcium-induced stomatal closure. Free cytosolic Ca2+ (Ca2+i) increases in response to a high extracellular calcium (Ca2+o) level through a CAS signalling pathway and finally leads to stomatal closure. Multidisciplinary approaches including histochemical, pharmacological, fluorescent, electrochemical, and molecular biological methods were used to discuss the relationship of hydrogen peroxide (H2O2) and nitric oxide (NO) signalling in the CAS signalling pathway in guard cells in response to Ca2+o. Here it is shown that Ca2+o could induce H2O2 and NO production from guard cells but only H2O2 from chloroplasts, leading to stomatal closure. In addition, the CASas mutant, the atrbohD/F double mutant, and the Atnoa1 mutant were all insensitive to Ca2+o-stimulated stomatal closure, as well as H2O2 and NO elevation in the case of CASas. Furthermore, it was found that the antioxidant system might function as a mediator in Ca2+o and H2O2 signalling in guard cells. The results suggest a hypothetical model whereby Ca2+o induces H2O2 and NO accumulation in guard cells through the CAS signalling pathway, which further triggers Ca2+i transients and finally stomatal closure. The possible cross-talk of Ca2+o and abscisic acid signalling as well as the antioxidant system are discussed
Effect of Long-Term Fertilization on Organic Nitrogen Forms in a Calcareous Alluvial Soil on the North China Plain
Recommended from our members
Empirical models for estimating monthly global solar radiation: a most comprehensive review and comparative case study in China
Global solar radiation is a core component of scientific research and engineering application across a broad spectrum. However, its measurement is limited by a small number of stations due to the technical and financial restricts. Estimating solar radiation with the meteorological variables using empirical models is of benefit to obtain solar radiation data at global scale. Yet, there are various options of available empirical models to select the most suitable one. This study conducted a most comprehensive collection and review of empirical models employing the commonly measured meteorological variables and geographic factors. A total of 294 different types of empirical models were collected and classified into 37 groups according to input attributes. Such collection built an empirical model library providing an overall overview of the developed empirical models in literatures. Furthermore, the collected models were calibrated and evaluated at three meteorological stations in the Three Gorges Reservoir Area in China. This study suggests that these model-comparing processes can assist the governments, scientists and engineers in tailoring the most fitted model for specific applications and in particular areas
A cell-targeted chemotherapeutic nanomedicine strategy for oral squamous cell carcinoma therapy
Structure-Based High-Throughput Epitope Analysis of Hexon Proteins in B and C Species Human Adenoviruses (HAdVs)
Human adenoviruses (HAdVs) are the etiologic agent of many human infectious diseases. The existence of at least 54 different serotypes of HAdVs has resulted in difficulties in clinical diagnosis. Acute respiratory tract disease (ARD) caused by some serotypes from B and C species is particularly serious. Hexon, the main coat protein of HAdV, contains the major serotype-specific B cell epitopes; however, few studies have addressed epitope mapping in most HAdV serotypes. In this study, we utilized a novel and rapid method for the modeling of homologous proteins based on the phylogenetic tree of protein families and built three-dimensional (3D) models of hexon proteins in B and C species HAdVs. Based on refined hexon structures, we used reverse evolutionary trace (RET) bioinformatics analysis combined with a specially designed hexon epitope screening algorithm to achieve high-throughput epitope mapping of all 13 hexon proteins in B and C species HAdVs. This study has demonstrated that all of the epitopes from the 13 hexon proteins are located in the proteins' tower regions; however, the exact number, location, and size of the epitopes differ among the HAdV serotypes
Genome-Wide Expression Profiling of Five Mouse Models Identifies Similarities and Differences with Human Psoriasis
Development of a suitable mouse model would facilitate the investigation of pathomechanisms underlying human psoriasis and would also assist in development of therapeutic treatments
Global, regional, and national incidence and mortality for HIV, tuberculosis, and malaria during 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013
BACKGROUND: The Millennium Declaration in 2000 brought special global attention to HIV, tuberculosis, and malaria through the formulation of Millennium Development Goal (MDG) 6. The Global Burden of Disease 2013 study provides a consistent and comprehensive approach to disease estimation for between 1990 and 2013, and an opportunity to assess whether accelerated progress has occured since the Millennium Declaration. METHODS: To estimate incidence and mortality for HIV, we used the UNAIDS Spectrum model appropriately modified based on a systematic review of available studies of mortality with and without antiretroviral therapy (ART). For concentrated epidemics, we calibrated Spectrum models to fit vital registration data corrected for misclassification of HIV deaths. In generalised epidemics, we minimised a loss function to select epidemic curves most consistent with prevalence data and demographic data for all-cause mortality. We analysed counterfactual scenarios for HIV to assess years of life saved through prevention of mother-to-child transmission (PMTCT) and ART. For tuberculosis, we analysed vital registration and verbal autopsy data to estimate mortality using cause of death ensemble modelling. We analysed data for corrected case-notifications, expert opinions on the case-detection rate, prevalence surveys, and estimated cause-specific mortality using Bayesian meta-regression to generate consistent trends in all parameters. We analysed malaria mortality and incidence using an updated cause of death database, a systematic analysis of verbal autopsy validation studies for malaria, and recent studies (2010-13) of incidence, drug resistance, and coverage of insecticide-treated bednets. FINDINGS: Globally in 2013, there were 1·8 million new HIV infections (95% uncertainty interval 1·7 million to 2·1 million), 29·2 million prevalent HIV cases (28·1 to 31·7), and 1·3 million HIV deaths (1·3 to 1·5). At the peak of the epidemic in 2005, HIV caused 1·7 million deaths (1·6 million to 1·9 million). Concentrated epidemics in Latin America and eastern Europe are substantially smaller than previously estimated. Through interventions including PMTCT and ART, 19·1 million life-years (16·6 million to 21·5 million) have been saved, 70·3% (65·4 to 76·1) in developing countries. From 2000 to 2011, the ratio of development assistance for health for HIV to years of life saved through intervention was US$4498 in developing countries. Including in HIV-positive individuals, all-form tuberculosis incidence was 7·5 million (7·4 million to 7·7 million), prevalence was 11·9 million (11·6 million to 12·2 million), and number of deaths was 1·4 million (1·3 million to 1·5 million) in 2013. In the same year and in only individuals who were HIV-negative, all-form tuberculosis incidence was 7·1 million (6·9 million to 7·3 million), prevalence was 11·2 million (10·8 million to 11·6 million), and number of deaths was 1·3 million (1·2 million to 1·4 million). Annualised rates of change (ARC) for incidence, prevalence, and death became negative after 2000. Tuberculosis in HIV-negative individuals disproportionately occurs in men and boys (versus women and girls); 64·0% of cases (63·6 to 64·3) and 64·7% of deaths (60·8 to 70·3). Globally, malaria cases and deaths grew rapidly from 1990 reaching a peak of 232 million cases (143 million to 387 million) in 2003 and 1·2 million deaths (1·1 million to 1·4 million) in 2004. Since 2004, child deaths from malaria in sub-Saharan Africa have decreased by 31·5% (15·7 to 44·1). Outside of Africa, malaria mortality has been steadily decreasing since 1990. INTERPRETATION: Our estimates of the number of people living with HIV are 18·7% smaller than UNAIDS's estimates in 2012. The number of people living with malaria is larger than estimated by WHO. The number of people living with HIV, tuberculosis, or malaria have all decreased since 2000. At the global level, upward trends for malaria and HIV deaths have been reversed and declines in tuberculosis deaths have accelerated. 101 countries (74 of which are developing) still have increasing HIV incidence. Substantial progress since the Millennium Declaration is an encouraging sign of the effect of global action. FUNDING: Bill & Melinda Gates Foundation
- …