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91.
In has been shown in the experiments on male rats that alimentary vitamin E deficit causes the decrease of reduced glutathione and ascorbic acid concentration in the liver and lungs and that of glutathione-S-transferase, glutathione reductase in the liver and lungs, catalase in the liver and glutathione peroxidase in the heart activity, but increases the amount of glutathione disulfide in the liver and lungs and superoxide dismutase and gamma-glutamyltransferase activity in the liver. The data obtained show the selective character of reaction participants of the antioxidant system of rats' organism to the deficit of one of the antioxidant factors--vitamin E and also testify to complex interrelation between separate members of this system.  相似文献   
92.
The utility of DNA Barcoding for species identification and discovery has catalyzed a concerted effort to build the global reference library; however, many animal groups of economical or conservational importance remain poorly represented. This study aims to contribute DNA barcode records for all ground squirrel species (Xerinae, Sciuridae, Rodentia) inhabiting Eurasia and to test efficiency of this approach for species discrimination. Cytochrome c oxidase subunit 1 (COI) gene sequences were obtained for 97 individuals representing 16 ground squirrel species of which 12 were correctly identified. Taxonomic allocation of some specimens within four species was complicated by geographically restricted mtDNA introgression. Exclusion of individuals with introgressed mtDNA allowed reaching a 91.6% identification success rate. Significant COI divergence (3.5–4.4%) was observed within the most widespread ground squirrel species (Spermophilus erythrogenys, S. pygmaeus, S. suslicus, Urocitellus undulatus), suggesting the presence of cryptic species. A single putative NUMT (nuclear mitochondrial pseudogene) sequence was recovered during molecular analysis; mitochondrial COI from this sample was amplified following re-extraction of DNA. Our data show high discrimination ability of 100 bp COI fragments for Eurasian ground squirrels (84.3%) with no incorrect assessments, underscoring the potential utility of the existing reference librariy for the development of diagnostic ‘mini-barcodes’.  相似文献   
93.

Background

Southeast Asia is recognized as a region of very high biodiversity, much of which is currently at risk due to habitat loss and other threats. However, many aspects of this diversity, even for relatively well-known groups such as mammals, are poorly known, limiting ability to develop conservation plans. This study examines the value of DNA barcodes, sequences of the mitochondrial COI gene, to enhance understanding of mammalian diversity in the region and hence to aid conservation planning.

Methodology and Principal Findings

DNA barcodes were obtained from nearly 1900 specimens representing 165 recognized species of bats. All morphologically or acoustically distinct species, based on classical taxonomy, could be discriminated with DNA barcodes except four closely allied species pairs. Many currently recognized species contained multiple barcode lineages, often with deep divergence suggesting unrecognized species. In addition, most widespread species showed substantial genetic differentiation across their distributions. Our results suggest that mammal species richness within the region may be underestimated by at least 50%, and there are higher levels of endemism and greater intra-specific population structure than previously recognized.

Conclusions

DNA barcodes can aid conservation and research by assisting field workers in identifying species, by helping taxonomists determine species groups needing more detailed analysis, and by facilitating the recognition of the appropriate units and scales for conservation planning.  相似文献   
94.
Human embryonic stem cells (hESC) are able to maintain pluripotency in culture, to proliferate indefinitely and to differentiate into all somatic cell types. Due to these unique properties, hESC may become an exceptional source of tissues for transplantation and have a great potential for the therapy of incurable diseases. Here, we review new developments in the area of embryonic stem cells and discuss major challenges — standardization of protocols for cell derivation and cultivation, identification of specific molecular markers, development of new approaches for directed differentiation, etc. — which remain to be settled, prior to safe and successful clinical application of stem cells. We appraise several potential approaches in hESC-based therapy including derivation of autologous cells via therapeutic cloning (1), generation of immune tolerance to allogenic donor cells via hematopoetic chimerism (2), and development of the banks of hESC lines compatible with the main antigens and exhibiting equivalent pluripotency (3). In addition, we discuss briefly induced pluripotent cells, which are derived via genetic modification of autologous somatic cells and are analogous to ESC. Our analysis demonstrates that uncontrollable differentiation in vivo and teratogenic potential of hESC are critical limitations of their application in clinical practice. Therefore, the major approach in hESC therapy is derivation of a specific differentiated progeny, which has lower proliferative potential and immune privilege, yet poses fewer risks for organism. The review demonstrates that cell therapy is far more complex and resource-consuming process as compared with drug-based medicine and consequently pluripotent stem cell biology and technology still requires further investigation and development before these cells can be used in clinical practice.  相似文献   
95.
Blood serum of patients suffering from cancer of the stomach and urinary bladder inhibited in vitro migration of autologous leukocytes, leukocytes of donors and control patients, and also guinea pig macrophages in over half of cases. In chromatography of these sera on Sephadex G-100 the activity inhibiting the leukocyte migration was revealed in fraction I (Mol. wt. over 100000) and in fractions IV and V (Mol. wt under 30 000). The blood serum and its fractions from cancer patients failed to eliminate the leukocyte migration inhibition caused by the tumour antigens in comparison with the leukocyte migration in the medium with control serum without any antigens. As suggested, the activity of fraction I inhibiting the leukocyte migration was due to the antigen-antibody complex, and of fraction IV and V--to a factor similar by its properties to the factor produced in vitro by lymphocytes stimulated by the antigens or mitogens.  相似文献   
96.
For the first time, the molecular complexation of adenine and guanine with hederagenin 3-O-α-L-rhamnopyranosyl-(1 2)-O-α-L-arabinopyranoside (α-hederin) and its 28-O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl ester (hederasaponin C) was investigated using the method of electrospray ionization mass spectrometry. Guanine forms more diversely composed complexes than adenine.  相似文献   
97.
The suggestion that the fish specimens caught in the littoral zone off Nedorazumeniya Island, Taui Bay, Sea of Okhotsk, belong to the eelpout species Magadanichthys skopetsi [23] and Hadropareia middendorffii Schmidt, 1904 has been confirmed by the analysis of their molecular-genetic and morphological characters. Their karyotypes have been studied for the first time: M. skopetsi, 2n = 48 (2 meta-, 26 subtelo-, and 20 acrocentric chromosomes), NF = 50; H. middendorffii, 2n = 48 (2 meta-, 36 subtelo-, and 10 acrocentric chromosomes), NF = 50. As a result of a comprehensive study, the levels of interspecific differentiation of these species has been established, the degree of intraspecific variability has been determined, and the lack of the population-geographical subdivision of H. middendorffii has been shown.  相似文献   
98.
For the first time, we studied the karyotype of the flathead sculpin Megalocottus platycephalus taeniopterus (Kner, 1868) from Vostok Bay of the Sea of Japan. The karyotype is stable: 2n = 42 (2 metacentric, 2 submeta-subtelocentric, 30 subtelocentric, and 8 acrocentric chromosomes), NF = 44 + 2. The nucleolar organizers (NOs) were identified using Ag banding in two pairs of chromosomes: in the telomeric parts of the short arm of the medium-size subtelocentric chromosome and the long arm of the large acrocentric chromosome. Variations in the number of nucleolar organizer chromosomes and in the number of NO staining blocks were found. Comparison of the karyotypes of M. p. taeniopterus and previously studied M. p. platycephalus (Pallas, 1814) from the northern Sea of Okhotsk revealed their similarity in the number and morphology of chromosomes and the number of chromosome arms and difference between the subspecies in the number and location of NO, which allows their discrimination.  相似文献   
99.
Biology Bulletin - Based on the results of qualitative and quantitative analysis of alkylresorcinol pools in the intestine and in the blood, as well as their correlations with the level of...  相似文献   
100.
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