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991.
Binding properties of naftopidil and alpha 1-adrenoceptor antagonists to alpha-adrenoceptors in prostates from benign prostatic hypertrophy (BPH) were characterized by radioreceptor assays using [3H]prazosin and [3H]rauwolscine. Specific binding of [3H]prazosin and [3H]rauwolscine in human prostatic membranes was saturable and of high affinity, and it showed a pharmacological specificity which characterized alpha 1 and alpha 2-adrenoceptors, respectively. Naftopidil and several alpha 1 antagonists competed for prostatic [3H]prazosin binding in order: R-(-)-YM-12617 greater than prazosin greater than bunazosin greater than terazosin greater than naftopidil greater than urapidil, and the inhibitory effect (Ki = 11.6 nM) of naftopidil was 10 to 45 times less potent than quinazoline derivatives such as prazosin, bunazosin and terazosin. The potencies of these antagonists in competing for [3H]prazosin binding sites in human prostates correlated well with their pharmacological potencies (pA2). Scatchard analysis indicated that the decrease of prostatic [3H]prazosin binding by naftopidil was due to a marked increase in the Kd value without a change in the Bmax value. The inhibition of prostatic [3H]prazosin binding by naftopidil was reversible. Naftopidil also inhibited prostatic [3H]rauwolscine binding (Ki = 70.0 nM). Thus, it is suggested that naftopidil antagonizes alpha 1-adrenoceptors in human prostates in a competitive and reversible manner.  相似文献   
992.
Inhibitory effects of danazol, an isoxazol derivative of synthetic steroid 17 alpha-ethinyl-testosterone, on the development of uterine adenomyosis, a pathological disorder of endometrial tissue defined as the presence of endometrial glands and stroma in the myometrium, were investigated in mice of SHN strain. Mice treated with 0.5 microgram danazol for 5 weeks during 4-9 weeks of age and killed at 21 weeks of age showed significantly lower incidence of the spontaneous development of adenomyosis than the age-matched intact control mice. The inhibitory effects of danazol were also evident in mice bearing pituitary isografts which were effective in inducing an early and a high incidence of adenomyosis. Furthermore, the treatment with danazol resulted in the decrease of serum levels of luteinizing hormone (LH) and prolactin (PRL) associated with hypofunction of ovaries and persistent diestrus. These results support the usefulness of danazol for the clinical treatment of gynecological disorders except for hypofunction of ovaries.  相似文献   
993.
In this paper we report on a study to elucidate whether the response of human lymphocytes to mitogenic stimulation was modified by physiological changes which occur during the menstrual cycle. Experiments with untreated cultures showed intra-individual variation to mitogen stimulation in female lymphocyte cultures, but a significant correlation between the menstrual cycle and the proliferation kinetics of lymphocytes was not found. Consequently, we performed experiments in which two of the hormones that regulate the menstrual cycle in women, estradiol and progesterone, were added to cultured human lymphocytes obtained from both men and women. The results indicate that both hormones at physiological concentrations have the capacity to modify the proliferation of PHA-stimulated human lymphocytes. Therefore, both hormones could play a role in the induction of the intra-individual variation observed in the untreated female cultures. However, in vivo other factors could also modify the proliferation kinetics of human lymphocytes preventing the demonstration of the effects of a single factor, such as the hormonal changes occurring during the menstrual cycle.  相似文献   
994.
The effect of two Bradyrhizobium japonicum strains (D344 and Urbana), on the frequency and intensity of infection by a VAM fungal Glomus sp. and the effect of VAM on biomass production by nodulating plants were tested in soybean growing in a soil containing low levels of accessible P and N. During the initial stage of vegetative growth, mycorrhiza frequency in roots inoculated with the two rhizobial strains did not differ. However, during flowering it was 178% higher in roots with the strain D344 than in the presence of the strain Ubrana. At final harvest (green pods) the VAM frequency did not differ in the presence of either strain. VAM positively affected biomass production, foliar concentrations of P, Zn and Cu, and number and dry matter yield of pods, but did not increase concentrations of total N and K. In nonmycorrhizal plants total nitrogenase activity (not nodule mass) and growth were higher with the rhizobial strain Urbana. The greatest nitrogenase activity, growth and yield occurred in the presence of the VAM fungus, and did not differ for plants with different strains of rhizobia.  相似文献   
995.
Five cDNAs of auxin-regulated genes were isolated from mungbean (Vigna radiata) hypocotyl sections by differential hybridizationscreening. They were related to the soybean genes, Aux22 [Ainleyet al. (1988) J. Biol. Chem. 263: 10658] and SAUR [McClure etal. (1989) Plant Cell 1: 229]. Regulation of expression of thesegenes, examined by Northern blot analysis, appeared similarto that reported in soybean hypocotyls. (Received August 10, 1991; Accepted October 14, 1991)  相似文献   
996.
Newborn female BALB/cCrgl mice receiving 5 micrograms of testosterone or 0.01 micrograms of diethylstilbestrol daily for the first 5 days of life were examined at various times after secondary exposure to testosterone and 17 beta-estradiol, respectively. Neonatal administration of testosterone induced squamous stratification associated with constant cornification of the vaginal epithelium in intact mice. Later exposure to testosterone suppressed cornification, resulting in superficial epithelial mucification in almost all mice by 4 months of age. However, at 6 months of age, the incidence of mucification dropped to 58%. Cervicovaginal lesions developed in the groups of mice given neonatal testosterone in combination with later testosterone and sacrificed at 4 and 6 months of age. Continuous vaginal stratification was found in 14% of ovariectomized, neonatally diethylstilbestrol-treated mice at 13 months of age. The incidence of this ovary-independent change increased to 40% at 24 months of age. Postnatal estrogen replacement significantly increased the incidence of squamous stratification in these mice. Neonatal diethylstilbestrol treatment alone induced cervicovaginal lesions in 4.5% of ovariectomized mice at 13 months of age; secondary 17 beta-estradiol exposure significantly enhanced the development of lesions to 44%. However, at 24 months of age, there was no difference in the incidence of lesions in ovariectomized, neonatally treated mice with or without the secondary 17 beta-estradiol treatment. These results suggest that the effects of neonatal exposure to a relatively low dose of estrogen, androgen, or related substance may become obvious later in life as a result of later exposure to hormones.  相似文献   
997.
The general identification of endocrine cells in the stomach of the lizard Podarcis hispanica was carried out by their response to the Grimelius and Masson-Fontana techniques. 11 immunoreactive cell-types, positive for chromogranin-, serotonin-, caerulein/gastrin/ cholecystokinin (CAER/G/CCK)-, glucagon-like-peptide-1 (GLP-1)-. glucagon-, bombesin-,somatostatin-, pancreatic polypeptide (PP)-, peptide tyrosine tyrosine (PYY)-, neurotensin-and calcitonin gene related peptide (CGRP)- antisera were detected by immunocytochemical methods. Co-existence of glucagon with GLP-1, and PP with PYY were observed in some cells. Furthermore, immunoreactivities for members of gastrin and PP families were also found to co-exist in a few cells. In the muscular layer, vasoactive intestinal peptide (VIP)- and substance P-immunoreactive nerve fibers were also found.  相似文献   
998.
Laboratory bioassays were conducted to determine the relative susceptibility of eggs, 1st-, 3rd-, 5th-instar nymphs and adults of Rhodnius prolixus to one isolate of the entomopathogenic hyphomycete, Beauveria bassiana. Treatments consisted of directly spraying on insects of increasing doses of inoculum (3 x 10(2) to 3 x 10(5) conidia per cm2). Mortality due to all doses of conidia was very high in the five tested stages of the target insect. Experiments on eggs demonstrated that the fungal isolate was able to kill eggs before they hatched. Both time-mortality and dose-mortality responses showed that the susceptibility of R. prolixus varied according to its stage of development and increased with age. As a matter of fact, at the dose of 3 x 10(3) conidia per cm2, LD 50 varied between 11.2 days in 1st-instar nymphs and 6.4 days in both 5th-instar nymphs and adults. Comparison of LD50 permitted to estimate that 1st-instar nymphs were about 700-fold less susceptible than the two oldest stages.  相似文献   
999.
1000.
The effect of light exposure during collection and culture of hamster embryos on their subsequent development in vitro was examined. When embryos were collected under dark conditions (70 lux) within 10 minutes and then cultured in a HECM-1 medium in 5% CO(2) in air, the developmental rates of 1-cell embryos to the 4- and 8-cell stages were 88.6% (93 105 ) and 66.7% (70 105 ), respectively. These rates were significantly higher than those under light conditions (1600 lux): 51.9% (56 108 ) and 34.3% (37 108 ). Light irradiation during the culture of 1-cell embryos suppressed subsequent development. The degree of suppression correlated inversely with duration of light irradiation, and light irradiation of 30 minutes or more completely blocked development to the 2-cell stage. When 1-cell embryos were irradiated through a yellow filter, cutting the light wavelengths to less than 500 nm, embryonic development was still suppressed. However, the degree of the suppression varied and 45.7% (53 116 ), 6.0% (7 116 ), and 0.9% (1 116 ) of the embryos developed to the 2-, 4-, and 8-cell stages, respectively, under 30 minute light irradiation. Inhibitory effects of light irradiation on the development of 2- and 8-cell embryos were also observed, showing an inverse correlation with duration; the developmental rates of 2-cell embryos to the 8-cell stage under 0, 10, and 30 minutes of irradiation were 85.6% (107 125 ), 1.6% (2 122 ), and 0% (0 129 ), respectively, and those of 8-cell embryos to the blastocyst stage were 79.8% (91 114 ), 74.8% (86 115 ), and 0% (0 110 ), respectively. These findings indicate that early-stage embryos are sensitive to light exposure; however, severe light exposure adversely affects the development of embryos at any stage. Thus, the protection of embryos from light exposure at all stages of embryo manipulation, from collection to culture, is essential.  相似文献   
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