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31.
Three-dimensional network of smooth muscle cells (SMC) with processes was found in the subendothelial intima of human aorta. The cells were connected with each other through gap junctions. In the direction from the media to the endothelium the number of plasma membrane caveolae increased, their distribution becoming more random. In the fatty streak, the integrity of cellular network was seen destroyed. In the extracellular matrix multilamellar ball-like structures containing large intramembranous particles appeared. In the fibrous plaque, SMCs are completely isolated by connective tissue fibres.  相似文献   
32.
We have discussed some aspects of the production and efficiency of energy use in aquatic ecosystems. Ecosystem production is defined as the difference between the gross total primary production and total expenditures for metabolic processes in all organisms of the ecosystem. We have obtained equations showing the dependence of ecosystem production on the average depth of a waterbody and the share of the primary production of phytoplankton in the total production. The mean value of the coefficient of ecosystem efficiency in some waterbodies (53%) indicates that aquatic ecosystems use energy efficiently. The efficiency of the energy use increases with an increase in the biomass turnover rate. High production in the ecosystem can be obtained if its structure is simpler.  相似文献   
33.

Background  

The male-specific region of the mouse Y chromosome long arm (MSYq) is comprised largely of repeated DNA, including multiple copies of the spermatid-expressed Ssty gene family. Large deletions of MSYq are associated with sperm head defects for which Ssty deficiency has been presumed to be responsible.  相似文献   
34.
The possibility of high velocity mechanical transfer of foreign DNA into inner cell mass of mouse blastocyst was shown. Penetration of tungsten microparticles into early embryo cell nuclei and their localization on mitotic chromosomes was demonstrated. About 70% of developing embryos survived the bombardment. Total DNA of the mice born from bombarded embryos was analyzed by blot-hybridization and PCR with Southern hybridization. In three cases, the presence of the transferred plasmid DNA (pSV3-neo) was revealed.  相似文献   
35.
The number of phytoplankton, zooplankton, and macrobenthos species was studied in continental lakes of diverse origin, geographical position, and hydrochemical (water mineralization) and morphological (area and capacity) characteristics. It is shown that the diversity of benthos communities depends on mineralization, area, and capacity of the waterbody, the dependence on area and mineralization being stronger than the dependence on capacity. Zooplankton community diversity depends on water mineralization and, to a very small extent, on waterbody area. The number of phytoplankton species in a lake is not strictly determined by morphometric characteristics and water mineralization. This number is to a greater extent dependent on other factors (e.g., light, nutrients, etc.). The largest number of benthos and plankton species was observed in waterbodies with water mineralization around 0.4 g/l. Increase in mineralization leads not only to decrease in species number, but also to simplification of community structure in plankton and bottom organisms, which is reflected by the Shannon index of diversity decreasing accordingly. The studied relations show wide dispersal in the number of species that can result, beside other factors unaccounted for, from the uneven reliability of the identifications and recordings of plankton and benthos species due to the different proficiency level of experts in taxonomy and systematics.  相似文献   
36.
37.
Fertilized eggs of loach (Misgurnus fossilis), rainbow trout (Salmo gairdneri) and zebrafish (Brachydanio rerio) were bombarded with high-velocity tungsten microprojectiles covered with plasmid DNA containing sequences of beta-galactosidase and neomycin phosphotransferase genes. About 70% of the eggs survived the bombardment. The activity of both transferred genes was revealed in the fish developed from the bombarded eggs. Neomycin phosphotransferase gene sequences were detected by means of PCR amplification and Southern hybridization in the total DNA of zebrafish that survived after G418 treatment.  相似文献   
38.

Background  

Annually, 41,000 people in the Netherlands have strokes. This has multiple physical and psychosocial consequences. Most patients return home after discharge from hospital. Quality aftercare by general practitioners is important to support patients at home. The purpose of this study is to examine the wellbeing of patients who returned home immediately after discharge from hospital, one year post stroke, in comparison with the general Dutch population of the same age and to determine factors that could influence wellbeing.  相似文献   
39.
Properdin (FP) is an essential positive regulator of the complement alternative pathway (AP) providing stabilization of the C3 and C5 convertases, but its oligomeric nature challenges structural analysis. We describe here a novel FP deficiency (E244K) caused by a single point mutation which results in a very low level of AP activity. Recombinant FP E244K is monomeric, fails to support bacteriolysis, and binds weakly to C3 products. We compare this to a monomeric unit excised from oligomeric FP, which is also dysfunctional in bacteriolysis but binds the AP proconvertase, C3 convertase, C3 products and partially stabilizes the convertase. The crystal structure of such a FP-convertase complex suggests that the major contact between FP and the AP convertase is mediated by a single FP thrombospondin repeat and a small region in C3b. Small angle X-ray scattering indicates that FP E244K is trapped in a compact conformation preventing its oligomerization. Our studies demonstrate an essential role of FP oligomerization in vivo while our monomers enable detailed structural insight paving the way for novel modulators of complement.  相似文献   
40.
Birt-Hogg-Dubé (BHD) syndrome is a rare autosomal dominant condition caused by mutations in the FLCN gene and characterized by benign hair follicle tumors, pneumothorax, and renal cancer. Folliculin (FLCN), the protein product of the FLCN gene, is a poorly characterized tumor suppressor protein, currently linked to multiple cellular pathways. Autophagy maintains cellular homeostasis by removing damaged organelles and macromolecules. Although the autophagy kinase ULK1 drives autophagy, the underlying mechanisms are still being unraveled and few ULK1 substrates have been identified to date. Here, we identify that loss of FLCN moderately impairs basal autophagic flux, while re-expression of FLCN rescues autophagy. We reveal that the FLCN complex is regulated by ULK1 and elucidate 3 novel phosphorylation sites (Ser406, Ser537, and Ser542) within FLCN, which are induced by ULK1 overexpression. In addition, our findings demonstrate that FLCN interacts with a second integral component of the autophagy machinery, GABA(A) receptor-associated protein (GABARAP). The FLCN-GABARAP association is modulated by the presence of either folliculin-interacting protein (FNIP)-1 or FNIP2 and further regulated by ULK1. As observed by elevation of GABARAP, sequestome 1 (SQSTM1) and microtubule-associated protein 1 light chain 3 (MAP1LC3B) in chromophobe and clear cell tumors from a BHD patient, we found that autophagy is impaired in BHD-associated renal tumors. Consequently, this work reveals a novel facet of autophagy regulation by ULK1 and substantially contributes to our understanding of FLCN function by linking it directly to autophagy through GABARAP and ULK1.  相似文献   
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