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981.
We had previously developed a porcine IVF system using a chemically defined medium, i.e., porcine gamete medium supplemented with theophylline, adenosine, and cysteine (PGMtac). In the present study, we investigated the utility of this IVF system using different types of semen: (1) cryopreserved ejaculated (n = 8); (2) cryopreserved epididymal (n = 4); and (3) liquid-stored ejaculated (n = 5). Cryopreserved spermatozoa were prepared by three methods. In vitro-matured porcine oocytes were fertilized for 20 h in PGMtac using each type of semen, and the presumptive zygotes were cultured in porcine zygote medium (PZM)-4 for 5 days. In the case of frozen-thawed spermatozoa, the number of spermatozoa per penetrated oocyte (1.1-1.7), rate of blastocyst formation (26-56%), and total number of cells per blastocyst (34-49) differed (P < 0.05) among freezing methods. However, blastocysts were produced using all types of cryopreserved spermatozoa (14-75%). When spermatozoa were liquid-stored for 1-14 days after semen collection, the rate of sperm penetration (P < 0.05) decreased as storage time increased, although there was no significant reduction in sperm motility during storage. In all groups, semen that had been stored within 10 days after collection enabled blastocyst production in vitro (20-48%). In conclusion, this IVF system, which uses a chemically defined medium, had widespread utility with both frozen-thawed and liquid-stored spermatozoa.  相似文献   
982.
TRPC3 plays important roles in neuronal differentiation and immune cell maturation by mediating the cationic current in response to phospholipase C activation, Ca2+ depletion, and diacylglycerol stimulation. Here, we purified the TRPC3 channel using a glycosylated tetramer and observed the structure using electron microscopy. Negatively stained specimens demonstrate homogeneous protein particles containing an internal cavity-like structure. These particle images were picked up by automated pick-up programs, aligned, and classified by the growing neural gas network method. Similarly oriented projections were averaged to decrease the signal-to-noise ratio. The averaged images progress from the top view to the side views, which are representative of their raw images. The top view confirmed the hypothesis of a four-domain structure, and the side view demonstrates a large cytoplasmic domain with a capped structure at the bottom, which is near a predicted locus of ion release. The total image of the protein is a blunt-edged trapezoid of 200 x 200 x 235 A. This large dimension of TRPC3 is also supported by the Stokes radius (92 A) obtained from gel filtration chromatography.  相似文献   
983.
984.
Hordeum vulgare, cultivated barley, and its wild relative, H. chilense, have several important traits that might be useful for wheat improvement. Here, in situ hybridization and barley expressed sequence tag (EST) markers were used to characterize and compare the chromosomes of H. chilense with those of H. vulgare. FISH with four repetitive DNA sequences, AG, AAG, 5S rDNA and 45S rDNA, was applied to the mitotic chromosomes of H. vulgare, H. chilense and available wheat-H. chilense addition and substitution lines. FISH with the AAG repeat differentiated the individual chromosomes of H. chilense and H. vulgare. The patterns of FISH signals in the two species differed greatly. The 45S rDNA signals were observed on two pairs of chromosomes in both species, while the 5S rDNA signals were observed on four pairs of chromosomes in H. vulgare and on one pair in H. chilense. The AG repeat showed FISH signals at the centromeric regions of all chromosomes of H. vulgare but none of the chromosomes of H. chilense. These results indicate that the chromosomes of the two species are highly differentiated. To study the homoeology between the two species, 209 EST markers of H. vulgare were allocated to individual chromosomes of H. chilense. One hundred and forty of the EST markers were allocated to respective chromosomes of H. chilense using the wheat-H. chilense addition and substitution lines. Twenty-six EST markers on average were allocated to each chromosome except to the chromosome 2H(ch)S, to which only 10 markers were allocated. Ninety percent of the allocated EST markers in H. chilense were placed on H. vulgare chromosomes of the same homo-eologous group, indicating that the expressed sequences of the two species were highly conserved. These EST markers would be useful for detecting chromatin introgressed from these species into the wheat genome.  相似文献   
985.
Two parallel synthetic methods using solid-supported reagents were established to examine the rapid optimization of weak hit compound 1. Several compounds showed high potency in the low nanomolar range against N-myristoyltransferase. The structure-activity relationship (SAR) and antifungal activities of a series of novel 2-aminobenzothiazole N-myristoyltransferase inhibitors are presented.  相似文献   
986.
A new type of electrolyzed hydrogen-saturated (EHS) water was produced using a water-electrolyzing device equipped with a special cation exchanger. Use of the EHS water for drinking in a feeding test with rats elicited an antioxidative effect. After intraperitoneal injection of 2,2-azobis-amidinopropane dihydrochloride, urinary secretion of 8-hydroxydeoxyguanosine and hepatic formation of peroxidized lipid were significantly lessened in rats which had received the EHS water for one week. These results suggest the possibility that this drinking water shows an effect in reduction of oxidative stress in the body.  相似文献   
987.
Maternal mRNAs localized to specific regions in eggs play important roles in the establishment of embryonic axes and germ layers in various species. Type I postplasmic/PEM mRNAs, which are localized to the posterior-vegetal cortex (PVC) of fertilized ascidian eggs, such as the muscle determinant macho-1 mRNA, play key roles in embryonic development. In the present study, we analyzed the function of the postplasmic/PEM RNA Hr-POPK-1, which encodes a kinase of Halocynthia roretzi. When the function of POPK-1 was suppressed by morpholino antisense oligonucleotides, the resulting malformed larvae did not form muscle or mesenchyme, as in macho-1-deficient embryos. Epistatic analysis indicated that POPK-1 acts upstream of macho-1. When POPK-1 was knocked down, localization of every Type I postplasmic/PEM mRNA examined, including macho-1, was perturbed, showing diffuse early distribution and eventual concentration into a smaller area. This is the probable reason for the macho-1 dysfunction. The postplasmic/PEM mRNAs such as macho-1 and Hr-PEM1 are co-localized with the cortical endoplasmic reticulum (cER) and move with it after fertilization. Eventually they become highly concentrated into a subcellular structure, the centrosome-attracting body (CAB), at the posterior pole of the cleaving embryos. The suppression of POPK-1 function reduced the size of the domain of concentrated cER at the posterior pole, indicating that POPK-1 is involved in the movement of postplasmic/PEM RNAs via relocalization of cER. The CAB also shrank. These results suggest that Hr-POPK-1 plays roles in concentration and positioning of the cER, as well as in the concentration of CAB materials, such as putative germ plasm, in the posterior blastomeres.  相似文献   
988.
BACKGROUND: The fission yeast Schizosaccharomyces pombe has a cylindrical cell shape, for which growth is strictly limited to both ends, and serves as an excellent model system for genetic analysis of cell-polarity determination. Previous studies identified a cell-end marker protein, Tea1, that is transported by cytoplasmic microtubules to cell tips and recruits other cell-end factors, including the Dyrk-family Pom1 kinase. The deltatea1 mutant cells cannot grow in a bipolar fashion and show T-shaped morphology after heat shock. RESULTS: We identified Wsh3/Tea4 as a novel protein that interacts with Win1 MAP kinase kinase kinase (MAPKKK) of the stress-activated MAP kinase cascade. Wsh3 forms a complex with Tea1 and is transported to cell tips by growing microtubules. The deltawsh3 mutant shows monopolar growth with abnormal Tea1 aggregate at the non-growing cell end; this abnormal aggregate fails to recruit Pom1 kinase. Consistent with the observed interaction between Win1 and Wsh3, cells lacking Wsh3 or Tea1 show more severe cell-polarity defects under osmolarity and heat-stress stimuli that are known to activate the stress MAPK cascade. Furthermore, mutants of the stress MAPK also exhibit cell-polarity defects when exposed to the same stress. CONCLUSIONS: Wsh3/Tea4 is an essential component of the Tea1 cell-end complex. In addition to its role in bipolar growth during the normal cell cycle, the Wsh3-Tea1 complex, together with the stress-signaling MAPK cascade, contributes to cell-polarity maintenance under stress conditions.  相似文献   
989.
The callus of a metal hypertolerant fern, Athyrium yokoscense, was induced from the spores generated on a small sectioned frond in vitro. The callus grew vigorously with the periodical medium change, especially in a liquid culture. When the callus and regenerated tissues were exposed to Cd, every tissue tolerated at least 1 mM Cd for >1 month. These tissues accumulated high levels of Cd (maximum 3.3 mg g–1 dry weight in roots) in accordance with the Cd concentration of the medium, and the Cd concentrations of all parts, except roots, were at a similar level. The data suggest that the Cd tolerance of this fern is basically independent of the plant parts and the developmental stages, although the accumulation ability is higher in roots than in the other plant parts.  相似文献   
990.
Hori K  Ono T  Iwata H  Nokubi T  Kumakura I 《Gerodontology》2005,22(4):227-233
Objectives: The tongue plays an important role in swallowing by contacting the palate. The aim of the present study was to investigate the characteristics of tongue pressure production during swallowing in post‐stroke patients using a newly developed sensor sheet. Materials and methods: Ten post‐stroke inpatients with hemiplegia and five healthy volunteers participated in this study. Magnitude of tongue pressure during a dry swallow was measured using a newly developed sensor sheet comprising five sensors applied directly to the palate or to the palatal surface of a maxillary denture using denture adhesive. Swallowing ability was evaluated by measuring the time taken to swallow 30 ml of water. The magnitude of tongue pressure was compared between the post‐stroke patients and healthy subjects as well as between each measuring point in both groups. The relationship between tongue pressure and swallowing ability and that between tongue pressure and state of occlusal support were also examined. Results: The magnitude of tongue pressure in the post‐stroke patients was smaller than that of the healthy subjects at the measuring points along the median line (Welch test, p < 0.05), larger in the non‐paralysed side than in the paralysed side (two‐way anova , p < 0.05), and was influenced by swallowing ability and occlusal support (Welch test, p < 0.05). Conclusions: Measurement of the magnitude of tongue pressure shows promise as a simple, non‐invasive and quantitative method by which tongue activity in post‐stroke patients, in whom swallowing ability is a concern, could be evaluated.  相似文献   
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