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排序方式: 共有168条查询结果,搜索用时 15 毫秒
61.
62.
Large saline lakes of former USSR: a summary review 总被引:1,自引:1,他引:0
Shoot biomass and nitrogen, accumulated within above-ground plant biomass in autumn, correlate with nitrogen availability indicated by nitrogen content (% DM) of several shoot parts during the height of the growth period.A higher nitrogen percentage of the shoots is correlated with a higher shoot loss and subsequent substitution by branching and tillering during and continuing toward the end of the growth period. A delayed switch from the vegetative to the generative phase reduces the translocation of reserve material to the rhizome. Increasing nitrogen load is at least one of the factors causing instability and reed-belt decline. 相似文献
63.
The appearance of muscle proteins in the contractile apparatus of the mussel Mytilus trossulus was subjected to comparative analysis during ontogenesis. It was established, with the use of Western blot analysis and electrophoresis in polyacrylamid gel in the presence of sodium dodecylsulfate, that proteins of the contractile apparatus of mussel muscles express long before the formation of the first functionally active muscle system of the veliger larvae. Paramyosin is present in egg cells; twitchin, myorod, and actin appear at the stage of blastula (12 h after fertilization), and myosin appears at the trochophore stage (17 h after fertilization). The quantitative relation of muscle proteins was studied in actomyosin extracts of larvae obtained from different developmental stages. It was shown that the ratios actin/myosin and paramyosin/myosin at the veliger stage (96 h after fertilization) were found to be similar to those in the striated muscles of invertebrates. 相似文献
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V. A. Popkov D. N. Silachev S. S. Jankauskas L. D. Zorova I. B. Pevzner V. A. Babenko E. Y. Plotnikov D. B. Zorov 《Biochemistry. Biokhimii?a》2016,81(12):1480-1487
Aging is associated with a decline of various body functions, including ability to regenerate. Over recent decades, it has been demonstrated that some of these changes could be reversed in response to factors originating from a young organism, for example, fetal stem cells or “young blood” in models of heterochronic parabiosis. Pregnancy might be considered as parabiotic model of the interaction between two organisms of different age. In this work, we analyzed and summarized data on the effects of pregnancy on the maternal organism that confirm the hypothesis that pregnancy rejuvenates the mother’s organism or slows its aging. 相似文献
66.
Hannah Gardener Della David Morte Mitchell SV Elkind Ralph L Sacco Tatjana Rundek 《BMC cardiovascular disorders》2009,9(1):1-8
Background
Heterogeneity in B-type natriuretic peptide (BNP) levels, especially among individuals with acute heart failure with normal left ventricular ejection fraction (HFNEF), can cause confusion in interpreting results. We investigated the characteristics of cases of acute HFNEF with only modestly elevated BNP.Methods
One hundred forty-two patients with acute or acute exacerbation of chronic HFNEF were divided into two groups by BNP level: BNP < 100 pg/ml (NB group, n = 45) and BNP ≥ 100 pg/ml (B group, n = 97). We compared clinical findings, echocardiography results, and neurohormonal factors between these two groups.Results
In the NB group, a history of open-heart surgery (OHS) was more frequent (71% vs. 22%, p < 0.0001) and hypertension was less frequent (p = 0.0005). Left atrial diameter (LAd) was higher (p = 0.0026), while interventricular septal thickness, posterior wall thickness, relative wall thickness, left ventricular mass index were lower (p = 0.0005, p = 0.0225, p = 0.0114, p = 0.0051, respectively) in the NB group. In patients with HFNEF, a history of OHS remained an independent predictor of BNP level (< 100 pg/ml) after adjustment for hypertension, age, LAd, and interventricular septal thickness (odds ratio 3.6, p = 0.0252).Conclusion
We found associations between acute HFNEF with less elevated BNP and a history of OHS. In a patient suspected of HFNEF, a history of OHS is considered diagnostic evidence of presence of diastolic heart failure when plasma levels of BNP are less elevated. 相似文献67.
E. Y. Plotnikov D. N. Silachev A. A. Chupyrkina M. I. Danshina S. S. Jankauskas M. A. Morosanova E. V. Stelmashook A. K. Vasileva E. S. Goryacheva Y. A. Pirogov N. K. Isaev D. B. Zorov 《Biochemistry. Biokhimii?a》2010,75(2):145-150
A mitochondria-targeted chimeric compound consisting of a rhodamine derivative linked to a plastoquinone molecule (10-(6′-plastoquinonyl)decylrhodamine, SkQR1) was studied under conditions of acute brain or kidney damage. A protective effect of this compound was demonstrated in a model of focal brain ischemia, rat kidney ischemia/reperfusion, myoglobinuria (rhabdomyolysis, or crush syndrome), and pyelonephritis. We found that a single intraperitoneal injection of SkQR1 diminishes the size of the ischemic zone in the brain and improves performance of a test characterizing neurological deficit in ischemic animals. An analog of SkQR1 not containing plastoquinone (C12R19) was not neuroprotective. The data show that SkQR1 is a nephroprotectant and neuroprotectant, which can be due to the antioxidative action of this Skulachev cation. 相似文献
68.
Schuetz A Allali-Hassani A Martín F Loppnau P Vedadi M Bochkarev A Plotnikov AN Arrowsmith CH Min J 《The EMBO journal》2006,25(18):4245-4252
Histone methylation at specific lysine residues brings about various downstream events that are mediated by different effector proteins. The WD40 domain of WDR5 represents a new class of histone methyl-lysine recognition domains that is important for recruiting H3K4 methyltransferases to K4-dimethylated histone H3 tail as well as for global and gene-specific K4 trimethylation. Here we report the crystal structures of full-length WDR5, WDR5Delta23 and its complexes with unmodified, mono-, di- and trimethylated histone H3K4 peptides. The structures reveal that WDR5 is able to bind all of these histone H3 peptides, but only H3K4me2 peptide forms extra interactions with WDR5 by use of both water-mediated hydrogen bonding and the altered hydrophilicity of the modified lysine 4. We propose a mechanism for the involvement of WDR5 in binding and presenting histone H3K4 for further methylation as a component of MLL complexes. 相似文献
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