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991.
Haubner F Lehle K Münzel D Schmid C Birnbaum DE Preuner JG 《Biochemical and biophysical research communications》2007,360(3):560-565
Hyperglycemia is the major cause of diabetic angiopathy. Aim of our study was to evaluate the impact of high glucose on cell growth and function of human "diabetic" endothelial cells (EC). Incubation of non-diabetic EC with glucose moderately inhibited cell growth and increased the expression of ICAM-1 and E-selectin. In the disease-specific EC, glucose treatment resulted also in moderately inhibited cell growth by 5-10%, increased basal expression of VCAM-1 by 10-20%, and an enhanced release of monocyte-chemoattractant-protein-1 (MCP-1) by 40-70%. The expression of ICAM-1 and E-selectin and the release of IL-6 and IL-8 was not affected. The usage of our disease-specific EC model might evaluate the impact of systemic factors of diabetic patients in the progression of endothelial dysfunction, and may be suitable to develop relevant therapeutic regimens. 相似文献
992.
An alternative method for measuring thiaminase I activity in complex samples is described. This assay is based on the selective consumption of the highly chromophoric 4-nitrothiophenolate by thiaminase I, resulting in a large decrease in absorbance at 411nm. This new assay is simple and sensitive, and it requires only readily available chemicals and a visible region spectrophotometer. In addition, the assay is optimized for high-throughput analysis in a 96-well format with complex biological samples. 相似文献
993.
Many plant species exhibit strong association with topographic habitats at local scales. However, the historical biogeographic and physiological drivers of habitat specialization are still poorly understood, and there is a need for relatively easy‐to‐measure predictors of species habitat niche breadth. Here, we explore whether species geographic range, climatic envelope, or intraspecific variability in leaf traits is related to the degree of habitat specialization in a hyperdiverse tropical tree community in Amazonian Ecuador. Contrary to our expectations, we find no effect of the size of species geographic ranges, the diversity of climate a species experiences across its range, or intraspecific variability in leaf traits in predicting topographic habitat association in the ~300 most common tropical tree species in a 25‐ha tropical forest plot. In addition, there was no phylogenetic signal to habitat specialization. We conclude that species geographic range size, climatic niche breadth, and intraspecific variability in leaf traits fail to capture the habitat specialization patterns observed in this highly diverse tropical forest. 相似文献
994.
Jiao Sima Abhijit Chakraborty Vishnu Dileep Marco Michalski Kyle N. Klein Nicolas P. Holcomb Jesse L. Turner Michelle T. Paulsen Juan Carlos Rivera-Mulia Claudia Trevilla-Garcia Daniel A. Bartlett Peiyao A. Zhao Brian K. Washburn Elphège P. Nora Katerina Kraft Stefan Mundlos Benoit G. Bruneau Mats Ljungman David M. Gilbert 《Cell》2019,176(4):816-830.e18
995.
996.
Juliane Kellner Tobias Houska Remy Manderscheid Hans‐Joachim Weigel Lutz Breuer Philipp Kraft 《Global Change Biology》2019,25(9):2947-2957
The rising concentration of atmospheric carbon dioxide (CO2) is known to increase the total aboveground biomass of several C3 crops, whereas C4 crops are reported to be hardly affected when water supply is sufficient. However, a free‐air carbon enrichment (FACE) experiment in Braunschweig, Germany, in 2007 and 2008 resulted in a 25% increased biomass of the C4 crop maize under restricted water conditions and elevated CO2 (550 ppm). To project future yields of maize under climate change, an accurate representation of the effects of eCO2 and drought on biomass and soil water conditions is essential. Current crop growth models reveal limitations in simulations of maize biomass under eCO2 and limited water supply. We use the coupled process‐based hydrological‐plant growth model Catchment Modeling Framework‐Plant growth Modeling Framework to overcome this limitation. We apply the coupled model to the maize‐based FACE experiment in Braunschweig that provides robust data for the investigation of combined CO2 and drought effects. We approve hypothesis I that CO2 enrichment has a small direct‐fertilizing effect with regard to the total aboveground biomass of maize and hypothesis II that CO2 enrichment decreases water stress and leads to higher yields of maize under restricted water conditions. Hypothesis III could partly be approved showing that CO2 enrichment decreases the transpiration of maize, but does not raise soil moisture, while increasing evaporation. We emphasize the importance of plant‐specific CO2 response factors derived by use of comprehensive FACE data. By now, only one FACE experiment on maize is accomplished applying different water levels. For the rigorous testing of plant growth models and their applicability in climate change studies, we call for datasets that go beyond single criteria (only yield response) and single effects (only elevated CO2). 相似文献
997.
Nadine Kraft Johannes Spaethe Wolfgang Rssler Claudia Groh 《Developmental neurobiology》2019,79(4):287-302
Division of labor among workers is a key feature of social insects and frequently characterized by an age‐related transition between tasks, which is accompanied by considerable structural changes in higher brain centers. Bumble bees (Bombus terrestris), in contrast, exhibit a size‐related rather than an age‐related task allocation, and thus workers may already start foraging at two days of age. We ask how this early behavioral maturation and distinct size variation are represented at the neuronal level and focused our analysis on the mushroom bodies (MBs), brain centers associated with sensory integration, learning and memory. To test for structural neuronal changes related to age, light exposure, and body size, whole‐mount brains of age‐marked workers were dissected for synapsin immunolabeling. MB calyx volumes, densities, and absolute numbers of olfactory and visual projection neuron (PN) boutons were determined by confocal laser scanning microscopy and three‐dimensional image analyses. Dark‐reared bumble bee workers showed an early age‐related volume increase in olfactory and visual calyx subcompartments together with a decrease in PN‐bouton density during the first three days of adult life. A 12:12 h light‐dark cycle did not affect structural organization of the MB calyces compared to dark‐reared individuals. MB calyx volumes and bouton numbers positively correlated with body size, whereas bouton density was lower in larger workers. We conclude that, in comparison to the closely related honey bees, neuronal maturation in bumble bees is completed at a much earlier stage, suggesting a strong correlation between neuronal maturation time and lifestyle in both species. 相似文献
998.
999.
Jesús Aguirre‐Gutiérrez Imma Oliveras Sami Rifai Sophie Fauset Stephen Adu‐Bredu Kofi Affum‐Baffoe Timothy R. Baker Ted R. Feldpausch Agne Gvozdevaite Wannes Hubau Nathan J. B. Kraft Simon L. Lewis Sam Moore Ülo Niinemets Theresa Peprah Oliver L. Phillips Kasia Ziemińska Brian Enquist Yadvinder Malhi 《Ecology letters》2019,22(5):855-865
Climatic changes have profound effects on the distribution of biodiversity, but untangling the links between climatic change and ecosystem functioning is challenging, particularly in high diversity systems such as tropical forests. Tropical forests may also show different responses to a changing climate, with baseline climatic conditions potentially inducing differences in the strength and timing of responses to droughts. Trait‐based approaches provide an opportunity to link functional composition, ecosystem function and environmental changes. We demonstrate the power of such approaches by presenting a novel analysis of long‐term responses of different tropical forest to climatic changes along a rainfall gradient. We explore how key ecosystem's biogeochemical properties have shifted over time as a consequence of multi‐decadal drying. Notably, we find that drier tropical forests have increased their deciduous species abundance and generally changed more functionally than forests growing in wetter conditions, suggesting an enhanced ability to adapt ecologically to a drying environment. 相似文献
1000.
Anikin Kirill Rodyakina Ekaterina Veber Sergey Milekhin Alexander Latyshev Alexander Zahn Dietrich R. T. 《Plasmonics (Norwell, Mass.)》2019,14(6):1527-1537
Plasmonics - We report on the investigation of the localized surface plasmon resonance (LSPR) in periodical Au nanostructures. The arrays of Au nanoclusters and dimers were fabricated on Si and... 相似文献