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1.
Plant Cell, Tissue and Organ Culture (PCTOC) - Nano-technology has changed the properties of metal elements’ delivery into and effect on living systems. The current study, first, evaluated...  相似文献   
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Calcium and phosphoinositide signaling regulate cell division in model systems, but their significance in mammalian cells is unclear. Calcium-binding protein-7 (CaBP7) is a phosphatidylinositol 4-kinaseIIIβ (PI4KIIIβ) inhibitor required during cytokinesis in mammalian cells, hinting at a link between these pathways. Here we characterize a novel association of CaBP7 with lysosomes that cluster at the intercellular bridge during cytokinesis in HeLa cells. We show that CaBP7 regulates lysosome clustering and that PI4KIIIβ is essential for normal cytokinesis. CaBP7 depletion induces lysosome mislocalization, extension of intercellular bridge lifetime, and cytokinesis failure. These data connect phosphoinositide and calcium pathways to lysosome localization and normal cytokinesis in mammalian cells.  相似文献   
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Two steroid binding states of an estrogen receptor each with different equilibrium constants (Kd values) Rx (Kd = 0.06 nM) and Ry (Kd = 0.8 nM) have been identified and characterized in the hen and estrogen-stimulated chick oviduct. A third non-estrogen binding form of the receptor, designated Rnb, has also been identified. These three forms of the receptor are interconvertible and appear to have a common molecular weight of approx. 66,000 under denaturing conditions. Hydroxytamoxifen binds preferentially and with high affinity to Rx (Kd 0.03 nM) and the conversion of Rx to Ry which is mediated by gamma phosphoryl group of ATP is also inhibitable by hydroxytamoxifen. Thus receptor interconversion, which may have general application to hormone action, potentially explains agonist/antagonist activity. The conversion of the non-estrogen binding form of the receptor (Rnb) to the lower affinity receptor (Ry) in chick oviduct cytosol is catalyzed by a reaction requiring the loss of the terminal phosphoryl moiety from ATP. There is a specific requirement for Mg2+. We now describe that ammonium sulfate fractionation of the cytosol allows the separation of the receptor entities from the "activating factor" (Fy) that catalyzes the conversion of Rnb to Ry. In the presence of gamma [32P]-ATP at 30 degrees C the purified non-steroid binding form of the receptor is phosphorylated. Phosphoamino acid analysis using Partisil-10 SAX anion exchange resin demonstrates that a serine is phosphorylated; and quantitation of the phosphorylation is indicative of one phosphoserine/receptor molecule. Treatment of the receptor with the partially purified activating factor to induce estradiol binding causes a dramatic reduction in phosphorylation.  相似文献   
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Humans are facilitating the introduction and range expansion of invasive alien species (IAS), which have negatively impacted ecological and socio-economic systems worldwide. Understanding the global diffusion of IAS is important for developing environmental policies and management strategies. We estimate the rate of increase and the doubling times of the number of new records of 178 IAS using a global dataset with c. 3.4 million records obtained over c. 100 years. Here, we show that the number of records of IAS have exponentially increased with a mean double time of c. 14 years across the Earth. For the most analysed species, the number of records increased faster in the non-native than native continents, suggesting that such IAS might be exponentially expanding their range size. We also found that each continent has a taxonomic group with a particular increase in IAS records. Governments and scientists should pay attention to these taxonomic groups to implement appropriate control or management actions. Our study provides an indication that the current local, regional and continental efforts to control invasions may be not sufficient at the global scale. This is a concerning situation given the great number of areas available for invasion worldwide.

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Ecological niche modelling (ENM) has been used to quantify the potential occurrence of species, by identifying the main environmental factors that determine the presence of species across geographical space. We provide a large-scale survey of the distribution of ostracod species in South America, by using the domains of 25 river basins. From 221 known ostracod species, we estimate the potential distribution of 61 species, using ENM. Ten clusters of potential distribution patterns were found. Clusters 8 and 9 grouped most of the species, which presented high similarity of niche between them. Heterocypris paningi Brehm, 1934 (group 1) obtained higher niche variability. The minimum temperatures of the coldest month and the mean elevation of the river basin were most important to predict the potential distribution of ostracods of most groups. South America has a complex pattern of elevation, which affects species distributions indirectly through changes in local factors. For instance, the Andes mountains might impose a barrier for ostracod distribution in the southern part of South America because of the low temperatures and precipitation. The ENM indicated that some regions and/or basins of South America might be susceptible to the entry of several ostracod species, presently absent, including non-native species.

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Traumatic spinal cord injury (TSCI) is a condition with suffering of neural structures from acute trauma with short-term or permanent sensory and motor problems. This study was conducted with the aim of determining the prevalence of TSCI in Tehran with emphasis on demographic characteristics of patients and to evaluate the effect of computed tomography (CT) in determining fracture type and severity grade of injury among TSCI patients. In a cross-sectional study, all TSCI and spinal fracture patients (N = 520) who referred to the main trauma center in Tehran, Iran, in 2013 and 2014 were selected. Radiography and CT scan were prepared and reported blindedly by two radiologists. Majority of the patients was 21–30 years male, married and their most common occupation was car driver. A significant difference was observed between gender and etiology (P = 0.001). The main etiology was traffic accident followed by falling from height. While the most common location of injury for males was thoracic vertebrae followed by lumbar vertebrae; for females it was lumbar followed by thoracic. Majority of patients had ASIA (American Spinal Injury Association) impairment scale of E (normal), followed by B (sensory incomplete). Most of the cases were hospitalized less than one week. Age of the patient and duration of hospitalization had a significant association (P = 0.015). The results showed that in traumatic spinal cord events, traffic accident and falling from height are the main etiologies; hence, authorities in Iranian health system could consider preventive policies to decline the load and TSCI effects in hospitals and population.  相似文献   
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Further support for the pump-leak concept was obtained. Net transport was resolved into pump and leak components with the cardiac glycoside, ouabain. The specificity of ouabain as a pump inhibitor was demonstrated by its ineffectiveness when the pump was already inhibited by lack of one of the three pump substrates, sodium ion, potassium ion, or adenosine triphosphate. In the presence of ouabain the rates of passive transport of sodium and potassium ions changed almost in proportion to changes in their extracellular concentrations when one ion was exchanged for the other. In the presence of ouabain and at the extracellular concentrations which produced zero net transport, the ratio of potassium ions to sodium ions was 1.2-fold higher inside the cells than outside. This finding was attributed to a residual pump activity of less than 2% of capacity. The permeability to potassium ions was 10% greater than the permeability to sodium ions. A test was made of the independence of pump and leak. Conditions were chosen to change the rate through each pathway separately or in combination. When both pathways were active, net transport was the sum of the rates observed when each acted separately. A ratio of three sodium ions pumped outward per two potassium ions pumped inward was confirmed.  相似文献   
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Molecular Biology Reports - Cardiovascular diseases (CVDs) are the most common and the first cause of death worldwide. While some studies have investigated the association of the Adenosine...  相似文献   
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C2-Symmetric azobenzene-amino acid/peptide hybrids containing stable E-azo moiety have been synthesized. Upon irradiation with long wavelength UV, these compounds isomerized to the Z-form, whose thermal reisomerization to the E isomer slowed down considerably. These compounds exhibited in vitro moderate to strong inhibition of mammalian cellular protease Subtilisin Kexin Isozyme-1, also called Site 1 Protease, which plays vital roles in cholesterol synthesis, lipid metabolism, bone formation, and viral infections.  相似文献   
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