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排序方式: 共有671条查询结果,搜索用时 187 毫秒
661.
Yulia Pushkar Gregory Robison Brendan Sullivan Sherleen X. Fu Meghan Kohne Wendy Jiang Sven Rohr Barry Lai Matthew A. Marcus Taisiya Zakharova Wei Zheng 《Aging cell》2013,12(5):823-832
Analysis of rodent brains with X‐ray fluorescence (XRF) microscopy combined with immunohistochemistry allowed us to demonstrate that local Cu concentrations are thousands of times higher in the glia of the subventricular zone (SVZ) than in other cells. Using XRF microscopy with subcellular resolution and intracellular X‐ray absorption spectroscopy we determined the copper (I) oxidation state and the sulfur ligand environment. Cu K‐edge X‐ray absorption near edge spectroscopy is consistent with Cu being bound as a multimetallic Cu‐S cluster similar to one present in Cu‐metallothionein. Analysis of age‐related changes show that Cu content in astrocytes of the SVZ increases fourfold from 3 weeks to 9 months, while Cu concentration in other brain areas remain essentially constant. This increase in Cu correlates with a decrease in adult neurogenesis assessed using the Ki67 marker (both, however, can be age‐related effects). We demonstrate that the Cu distribution and age‐related concentration changes in the brain are highly cell specific. 相似文献
662.
Alexander N. Prutkov Andrey V. Matveev Lyubov E. Grebenkina Yulia V. Berezovskaya 《Nucleosides, nucleotides & nucleic acids》2019,38(8):550-566
The chemical ribosylation pathways of 5-substituted-1,2,4-triazole-3-carboxylates are discussed. For the products of the chemical synthesis of the 3(5)-alkyl- or 3(5)-aryl-substituted ribavirin analogues the anomer configuration and isomer composition were determined. 相似文献
663.
A trypsin-like proteinase (YPTP) and its endogenous inhibitor (ITYP) were isolated from the culture filtrate of the pathogenic bacterium Yersinia pseudotuberculosis, and their biological activities were studied. YPTP was found to be highly toxic for random-bred white mice. Under in vitro conditions the proteolytic enzyme destroyed protective proteins of the immune system of the animals--IgG, IgA, and proteins of the complement system (CIq, C3, and C5)--and, consequently, was a pathogenetic factor in yersinioses. The inhibitor ITYP was shown to manifest antibacterial activity against virulent forms of Yersinia pseudotuberculosis, Escherichia coli, and Salmonella typhimurium. The ITYP preparation was harmless and nontoxic. 相似文献
664.
David C. Aldridge Isobel S. Ollard Yulia V. Bespalaya Ivan N. Bolotov Karel Douda Juergen Geist Wendell R. Haag Michael W. Klunzinger Manuel Lopes-Lima Musa C. Mlambo Nicoletta Riccardi Ronaldo Sousa David L. Strayer Santiago H. Torres Caryn C. Vaughn Tadeusz Zając Alexandra Zieritz 《Global Change Biology》2023,29(3):575-589
We identified 14 emerging and poorly understood threats and opportunities for addressing the global conservation of freshwater mussels over the next decade. A panel of 17 researchers and stakeholders from six continents submitted a total of 56 topics that were ranked and prioritized using a consensus-building Delphi technique. Our 14 priority topics fell into five broad themes (autecology, population dynamics, global stressors, global diversity, and ecosystem services) and included understanding diets throughout mussel life history; identifying the drivers of population declines; defining metrics for quantifying mussel health; assessing the role of predators, parasites, and disease; informed guidance on the risks and opportunities for captive breeding and translocations; the loss of mussel–fish co-evolutionary relationships; assessing the effects of increasing surface water changes; understanding the effects of sand and aggregate mining; understanding the effects of drug pollution and other emerging contaminants such as nanomaterials; appreciating the threats and opportunities arising from river restoration; conserving understudied hotspots by building local capacity through the principles of decolonization; identifying appropriate taxonomic units for conservation; improved quantification of the ecosystem services provided by mussels; and understanding how many mussels are enough to provide these services. Solutions for addressing the topics ranged from ecological studies to technological advances and socio-political engagement. Prioritization of our topics can help to drive a proactive approach to the conservation of this declining group which provides a multitude of important ecosystem services. 相似文献
665.
Kvichansky Alexey A. Tret’yakova Liya V. Volobueva Maria N. Manolova Anna O. Stepanichev Mikhail Yu. Onufriev Mikhail V. Moiseeva Yulia V. Lazareva Natalia A. Bolshakov Alexey P. Gulyaeva Natalia V. 《Biochemistry. Biokhimii?a》2021,86(6):693-703
Biochemistry (Moscow) - Differential effect of the neonatal proinflammatory stress (NPS) on the development of neuroinflammation in the hippocampus and induction of the depressive-like behavior in... 相似文献
666.
Abdelazeez Walla Mohamed Abdelmaksood Anatolievna Kostyukova Yulia Zavdetovna Khusnetdinova Landysh Damirovna Alekbaeva Gulnaz Abou El-Dis Gamil Rayan Arnoldovna Timofeeva Olga 《In vitro cellular & developmental biology. Plant》2022,58(4):593-605
In Vitro Cellular & Developmental Biology - Plant - For the first time, suspension cultures produced tropane alkaloids and were obtained from root explants of Hyoscyamus muticus L. It was shown... 相似文献
667.
P N Razumovski? L P Koval'chuk S A Burtseva V N Iadovina 《Prikladnaia biokhimiia i mikrobiologiia》1978,14(3):383-388
Biological activity of lipid fractions of actinomycetes was examined on microorganisms and laboratory animals. The anabolic effect of the acetone fraction of Actinomyces aurigineus 2377 (on Wistar female rats), anabolic effect of sterols of Actinomyces griseus 15 (on chicks), and the high growth stimulating effect (up to 40-60%) of sterols of Actinomyces canosus 89 (on rats) were noted. The estrogenic effect of sterols of Act. griseus 15, Act. griseus 20 and Act. albodenitrificans 13a on the sex system was shown. The antimicrobial properties of lipid fractions differed in their selectivity with respect to the test organisms and depended also on the actinomycete species and cultivation conditions. 相似文献
668.
Maria S Fadeeva Cinthia Nú?ez Yulia V Bertsova Guadalupe Espín Alexander V Bogachev 《FEMS microbiology letters》2008,279(1):116-123
The catalytic properties of sodium-translocating NADH:quinone oxidoreductases (Na+-NQRs) from the marine bacterium Vibrio harveyi, the enterobacterium Klebsiella pneumoniae, and the soil microorganism Azotobacter vinelandii have been comparatively analyzed. It is shown that these enzymes drastically differ in their affinity to sodium ions. The enzymes also possess different sensitivity to inhibitors. Na+-NQR from A. vinelandii is not sensitive to low 2-n-heptyl-4-hydroxyquinoline N-oxide (HQNO) concentrations, while Na+-NQR from K. pneumoniae is fully resistant to either Ag+ or N-ethylmaleimide. All the Na+-NQR-type enzymes are sensitive to diphenyliodonium, which is shown to modify the noncovalently bound FAD of the enzyme. 相似文献
669.
Kinetochore individualization in meiosis I is required for centromeric cohesin removal in meiosis II
Yulia Gryaznova Leonor Keating Sandra A Touati Damien Cladire Warif El Yakoubi Eulalie Buffin Katja Wassmann 《The EMBO journal》2021,40(7)
Partitioning of the genome in meiosis occurs through two highly specialized cell divisions, named meiosis I and meiosis II. Step‐wise cohesin removal is required for chromosome segregation in meiosis I, and sister chromatid segregation in meiosis II. In meiosis I, mono‐oriented sister kinetochores appear as fused together when examined by high‐resolution confocal microscopy, whereas they are clearly separated in meiosis II, when attachments are bipolar. It has been proposed that bipolar tension applied by the spindle is responsible for the physical separation of sister kinetochores, removal of cohesin protection, and chromatid separation in meiosis II. We show here that this is not the case, and initial separation of sister kinetochores occurs already in anaphase I independently of bipolar spindle forces applied on sister kinetochores, in mouse oocytes. This kinetochore individualization depends on separase cleavage activity. Crucially, without kinetochore individualization in meiosis I, bivalents when present in meiosis II oocytes separate into chromosomes and not sister chromatids. This shows that whether centromeric cohesin is removed or not is determined by the kinetochore structure prior to meiosis II. 相似文献
670.