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91.
BACKGROUND: Genetic susceptibility to diseases is likely influenced by common DNA variants in the form of single nucleotide polymorphisms (SNPs). The value of SNPs for linkage and association mapping studies may depend on the distribution of SNP allele frequencies across populations. OBJECTIVES: To establish the SNP allelic frequencies among Caucasian and African American women for tumor necrosis factor (TNF)alpha, transforming growth factor (TGF)beta1, interleukin-10 (IL10), interleukin-6 (IL6), and interferon (IFN)gamma. MATERIALS AND METHODS: DNA was extracted from whole blood from 123 healthy, pregnant women. PCR-based genotyping was performed for the genes encoding TNFalpha (-308G/A), TGFbeta1 (codon 10C/T, codon 25C/G), IL10 (-1082A/G, -819T/C, -592A/C), IL6 (-174C/G) and IFNgamma (874T/A). Allele frequencies were determined by Hardy-Weinberg Equilibrium and Linkage Disequilibrium tests. Differences in the SNP allelic frequencies between Caucasians and African Americans were assessed by the chi(2) of Amitage trend test. RESULTS: SNP allelic and genotypic frequencies for IL6 and IFNgamma, but not for TNFalpha, TGFbeta1, and IL10, differed significantly between the Caucasian and African American women. CONCLUSIONS: Recognition of racial differences in SNP allelic and genotypic frequencies for selected cytokines is important for designing and powering future linkage and association mapping studies investigating the role of cytokines in human disease.  相似文献   
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Background  

The leukocyte common antigen related receptor (LAR) protein has been shown to modulate the signal transduction of a number of different growth factors, including insulin and insulin-like growth factor 1. Splice variants exhibit differing roles and are expressed according to tissue type and developmental stage.  相似文献   
93.

Background  

Enterococcus faecium has globally emerged as a cause of hospital-acquired infections with high colonization rates in hospitalized patients. The enterococcal surface protein Esp, identified as a potential virulence factor, is specifically linked to nosocomial clonal lineages that are genetically distinct from indigenous E. faecium strains. To investigate whether Esp facilitates bacterial adherence and intestinal colonization of E. faecium, we used human colorectal adenocarcinoma cells (Caco-2 cells) and an experimental colonization model in mice.  相似文献   
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Depleted uranium (DU) is used to reinforce armor shielding and increase penetrability of military munitions. Although the data are conflicting, DU has been invoked as a potential etiological factor in Gulf War syndrome. We examined regional brain DU accumulation following surgical implantation of metal pellets in male Sprague-Dawley rats for 3 or 6 mo. Prior to surgery, rats were randomly divided into five groups: Nonsurgical control (NS Control); 0 DU pellets/20 tantalum (Ta) pellets (Sham); 4 DU pellets/16 Ta pellets (Low); 10 DU pellets/10 Ta pellets (Medium); 20 DU pellets/0 Ta pellets (High). Rats were weighed weekly as a measure of general health, with no statistically significant differences observed among groups in either cohort. At the conclusion of the respective studies, animals were perfused with phosphate-buffered saline, pH 7.4, to prevent contamination of brain tissue with DU from blood. Brains were removed and dissected into six regions: cerebellum, brainstem (pons and medulla), midbrain, hippocampus, striatum, and cortex. The uranium content was measured in digested samples as its 238U isotope by high-resolution inductively coupled plasma-mass spectrometry. After 3 mo postimplantation, DU significantly accumulated in all brain regions except the hippocampus in animals receiving the highest dose of DU (p<0.05). By 6 mo, however, significant accumulation was measured only in the cortex, midbrain, and cerebellum (p<0.01). Our data suggest that DU implanted in peripheral tissues can preferentially accumulate in specific brain regions.  相似文献   
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Our main objective was to determine whether reactive oxygen species (ROS), such as superoxide (O(2)(-)) and hydrogen peroxide (H(2)O(2)), contribute to altered pulmonary vascular responses in piglets with chronic hypoxia-induced pulmonary hypertension. Piglets were raised in either room air (control) or hypoxia for 3 days. The effect of the cell-permeable superoxide dismutase mimetic (SOD; M40403) and/or PEG-catalase (PEG-CAT) on responses to acetylcholine (ACh) was measured in endothelium-intact and denuded pulmonary resistance arteries (PRAs; 90-to-300-microm diameter). To determine whether NADPH oxidase is an enzymatic source of ROS, PRA responses to ACh were measured in the presence and absence of a NADPH oxidase inhibitor, apocynin (APO). A Western blot technique was used to assess expression of the NADPH oxidase subunit, p67phox. A lucigenin-derived chemiluminescence technique was used to measure ROS production stimulated by the NADPH oxidase substrate, NADPH. ACh responses, which were dilation in intact control arteries but constriction in both intact and denuded hypoxic arteries, were diminished by M40403, PEG-CAT, the combination of M40403 plus PEG-CAT, as well as by APO. Although total amounts were not different, membrane-associated p67phox was greater in PRAs from hypoxic compared with control piglets. NADPH-stimulated lucigenin luminescence was nearly doubled in PRAs from hypoxic vs. control piglets. We conclude that ROS generated by NADPH oxidase contribute to the aberrant pulmonary arterial responses in piglets exposed to 3 days of hypoxia.  相似文献   
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Neurodegeneration is characterized by the cell death or loss of structure and/or function of neurons. Many neurodegenerative diseases including Parkinson's disease (PD) and Alzheimer's disease (AD) are the result of neurodegenerative processes. Metals are essential for many life processes, but they are also culpable for several neurodegenerative mechanisms. In this review, we discuss the role of metals in neurodegenerative diseases with emphasis on the utility of Caenorhabditis elegans (C. elegans) genetic models in deciphering mechanisms associated with the etiology of PD and AD.  相似文献   
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