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91.
The effect of LV properties on v p and the E/v p ratio remains a matter of debate. Therefore, the objective of this study is to explore – in a new hydraulic model – the individual contributions of LV relaxation, filling pressure and compliance in changes of E, v p and E/v p for different stages of diastolic function. A new hydraulic model, consisting of an open cylindrical LA connected to an ellipsoidal LV, is designed. E and v p are measured for varying values of (45–60–90 ms), LV compliance (0.45–1.35 ml/mmHg) and filling pressure (3–10–30 mmHg). The results are used for predicting the evolution of E, v p and E/v p during different stages of diastolic function. An increase in compliance decreases E, whereas it augments v p. v p is less load-dependent than E. E decreases with delayed relaxation, increases for the case of pseudonormalisation, and becomes higher than the reference values during restrictive filling. The v p value is lower for the case of delayed relaxation than for the reference situation. During pseudonormalisation, the value of v p remains lower than the reference value but higher than the value for delayed relaxation. . v p further decreases during restrictive filling. In conclusion, the effect of simultaneous changes in compliance and loading counterbalance changes in v p. Therefore, under normal physiologic conditions where load and compliance are coupled, v p is apparently load-insensitive and E/v p increases as filling pressure increases. Moreover, in the different stages of diastolic dysfunction, due to the interference of the co-varying relaxation, the increase in E/v p is more pronounced.  相似文献   
92.
Peripheral arterial disease (PAD) is a common, progressive manifestation of atherothrombotic vascular disease, which should be managed no different to cardiac disease. Indeed, there is growing evidence that PAD patients are a high risk group, although still relatively under-detected and under treated. This is despite the fact that PAD patients are an increased mortality rate comparable to those with pre-existing or established cardiovascular disease [myocardial infarction, stroke]. With a holistic approach to atherothrombotic vascular disease, our management of PAD can only get better.  相似文献   
93.
The developmental changes in the activity of kidney transamidinase in male and female rats were investigated. The activity in both sexes increased rapidly after birth, reaching adult levels at 4 days of age. After weaning, the activity in male rats remained constant, while in female rats i t declined to 60% ol that in males. Thus, transamidinase is in the neonatal cluster of enzyme differentiation.  相似文献   
94.
95.
Summary A pure archeocyte fraction was isolated from the fresh-water spongeEphydatia fluviatilis by density gradient centrifugation of dissociated cell suspensions. The nature and purity of the fraction were confirmed by electron microscopy.  相似文献   
96.
Diseases associated with point mutations in the mitochondrial DNA (mtDNA) are maternally inherited. We evaluated whether pre-implantation genetic diagnosis, based on polar body mutation load detection could be used to distinguish healthy from affected oocytes. Restriction Fragment Length Polymorphism (RFLP) analysis was used and validated, to determine A3243G tRNA(Leu(UUR)) mutation load in metaphase II oocytes and their respective first polar bodies. The results of this study show for the first time that the mutation load measured in the polar bodies correlates well with the mutation load in the respective oocytes. Therefore, human polar body analysis can be used as diagnostic tool to prevent transmission of mitochondrial disorders.  相似文献   
97.
The isolation and expansion of human neural cell types has become increasingly relevant in restorative neurobiology. Although embryonic and fetal tissue are frequently envisaged as providing sufficiently primordial cells for such applications, the developmental plasticity of endogenous adult neural cells remains largely unclear. To examine the developmental potential of adult human brain cells, we applied conditions favoring the growth of neural stem cells to multiple cortical regions, resulting in the identification and selection of a population of adult human neural progenitors (AHNPs). These nestin(+) progenitors may be derived from multiple forebrain regions, are maintainable in adherent conditions, co-express multiple glial and immature markers, and are highly expandable, allowing a single progenitor to theoretically form sufficient cells for approximately 4x10(7) adult brains. AHNPs longitudinally maintain the ability to generate both glial and neuronal cell types in vivo and in vitro, and are amenable to genetic modification and transplantation. These findings suggest an unprecedented degree of inducible plasticity is retained by cells of the adult central nervous system.  相似文献   
98.
Research laboratories studying the genetics of companion animals have no database tools specifically designed to aid in the management of the many kinds of data that are generated, stored and analyzed. We have developed a relational database, "DOG-SPOT," to provide such a tool. Implemented in MS-Access, the database is easy to extend or customize to suit a lab's particular needs. With DOG-SPOT a lab can manage data relating to dogs, breeds, samples, biomaterials, phenotypes, owners, communications, amplicons, sequences, markers, genotypes and personnel. Such an integrated data structure helps ensure high quality data entry and makes it easy to track physical stocks of biomaterials and oligonucleotides.  相似文献   
99.
Presented here is an analysis of the molecular evolutionary dynamics of the P gene among 76 representative sequences of the Paramyxoviridae and Rhabdoviridae RNA virus families. In a number of Paramyxoviridae taxa, as well as in vesicular stomatitis viruses of the Rhabdoviridae, the P gene encodes multiple proteins from a single genomic RNA sequence. These products include the phosphoprotein (P), as well as the C and V proteins. The complexity of the P gene makes it an intriguing locus to study from an evolutionary perspective. Amino acid sequence alignments of the proteins encoded at the P and N loci were used in independent phylogenetic reconstructions of the Paramyxoviridae and Rhabdoviridae families. P-gene-coding capacities were mapped onto the Paramyxoviridae phylogeny, and the most parsimonious path of multiple-coding-capacity evolution was determined. Levels of amino acid variation for Paramyxoviridae and Rhabdoviridae P-gene-encoded products were also analyzed. Proteins encoded in overlapping reading frames from the same nucleotides have different levels of amino acid variation. The nucleotide architecture that underlies the amino acid variation was determined in order to evaluate the role of selection in the evolution of the P gene overlapping reading frames. In every case, the evolution of one of the proteins encoded in the overlapping reading frames has been constrained by negative selection while the other has evolved more rapidly. The integrity of the overlapping reading frame that represents a derived state is generally maintained at the expense of the ancestral reading frame encoded by the same nucleotides. The evolution of such multicoding sequences is likely a response by RNA viruses to selective pressure to maximize genomic information content while maintaining small genome size. The ability to evolve such a complex genomic strategy is intimately related to the dynamics of the viral quasispecies, which allow enhanced exploration of the adaptive landscape.  相似文献   
100.
Steatohepatitis occurs in up to 20% of patients with fatty liver disease and leads to its primary disease outcomes, including fibrosis, cirrhosis, and increased risk of hepatocellular carcinoma. Mechanisms that mediate this inflammation are of major interest. We previously showed that overload of saturated fatty acids, such as that which occurs with metabolic syndrome, induced sphingosine kinase 1 (SphK1), an enzyme that generates sphingosine-1-phosphate (S1P). While data suggest beneficial roles for S1P in some contexts, we hypothesized that it may promote hepatic inflammation in the context of obesity. Consistent with this, we observed 2-fold elevation of this enzyme in livers from humans with nonalcoholic fatty liver disease and also in mice with high saturated fat feeding, which recapitulated the human disease. Mice exhibited activation of NFκB, elevated cytokine production, and immune cell infiltration. Importantly, SphK1-null mice were protected from these outcomes. Studies in cultured cells demonstrated saturated fatty acid induction of SphK1 message, protein, and activity, and also a requirement of the enzyme for NFκB signaling and increased mRNA encoding TNFα and MCP1. Moreover, saturated fat-induced NFκB signaling and elevation of TNFα and MCP1 mRNA in HepG2 cells was blocked by targeted knockdown of S1P receptor 1, supporting a role for this lipid signaling pathway in inflammation in nonalcoholic fatty liver disease.  相似文献   
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