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61.
Jean-yves Gillon Pierre-Alain Vitte Francoise Lemonnier Gabor Kato 《Drug development research》1994,32(1):42-49
Medifoxamine, an antidepressant agent which has an original chemical structure, has been shown through in vitro studies, utilising radioligand binding in tissue homogenates, to bind with moderately high affinity to 5-HT1c and 5-HT2 receptor subtypes and to 5-HT uptake sites (IC50 950, 980, and 1,500 nM, respectively). It has been shown to bind in vivo to rat brain 5-HT2 receptors after acute treatment with high dose (50 mg/kg, i.e., 133.9 μmol/kg). After 14 days continuous treatment with low dose (20 mg/kg, 53.6 μmol/kg), a decrease in the capacity of [3H]-5-HT uptake and a dose-dependent down-regulation of 5-HT2 receptors in rat cerebral cortex were observed. These results indicate that medifoxamine, which has been shown previously to act through dopaminergic systems, interacts also with central serotonergic neurotransmission and particularly with the 5-HT2 receptors, which could contribute to its antidepressant effect. 相似文献
62.
K. E. Anderson A. M. Dart E. A. Woodcock 《Clinical and experimental pharmacology & physiology》1994,21(2):141-144
1. Global myocariial ischaemia (MI) for periods greater tan 5 min caused an inhibition of phosphatidylinositol specific phospholipase C (PtdIns-PLC) activity. 2. Two min reperfusion following a 20 min MI period, a time point associated with reperfusion-induced arrhythmias, resulted in an activation of PtdIns-PLC activity, dependent on endogenous noradrenaline and mediated via al-adrenoceptors. 3. This 2 min reperfusion response, in contrast to healthy myocardium, resulted in: (i) enhanced PtdIns-PLC activity; (ii) increased sensitivity to endogenous noradrenaline; (iii) rapid increases in inositol(1,4,5)trisphosphate (Ins(1,4,5)P3); and (iv) PLC hydrolysis primarily of PtdIns(4,5)P2, such that the majority of InsP isomers derive from Ins(1,4,5)P3. 4. Together, these data suggest a functional role for Ins(1,4,5)P3 under postischaemic reperfusion conditions, and provide a possible link between al-adrenoceptor stimulation of the PtdIns turnover pathway and reperfusion injury. 相似文献
63.
应用国产ELISA试剂盒对157例肝癌、肝硬化病人血清中抗-HCV及HBV-M进行检测,101例肝癌10例抗-HCV阳性,阳性率为9.9%;56例肝硬化6例抗-HCV阳性,阳性率为10.7%;肝癌组抗HCV与HBsAg双阳性率79%(8/101),HBsAg阳性率为723%(73/101),明显高于HCV感染率,说明HBV仍是乙肝流行地区的主要相关因素。14例抗-HCV阳性(包括可疑阳性),肝癌外周血中8例(57.1%)HBsAg阳性,推测HCV可单独作用但更常与HBV形成混合感染参与慢性肝病的癌变过程。 相似文献
64.
Expression of tau protein in non-neuronal cells can result in a redistribution of the microtubule cytoskeleton into thick bundles of tau-containing microtubules (Lewis et al.: Nature 342:498-505, 1989; Kanai et al.: J Cell Biol 109:1173-1184, 1989). We reconstituted microtubule bundles using purified tubulin and tau in order to study the assembly of these structures. Taxol-stabilized tubulin polymers were incubated with various concentrations of recombinant human tau and examined by electron microscopy. With increasing concentrations of tau 3 (tau isoform containing three microtubule binding domains) or tau 4 (isoform containing four microtubule binding domains) the microtubules changed orientation from a random distribution to loosely and tightly packed parallel arrays and then to thick cables. In contrast, tau 4L, the tau isoform containing four microtubule binding domains plus a 58-amino acid insert near the N-terminus, showed minimal bundling activity. tau 4-induced bundling could be inhibited by the addition of 0.5 M NaCl or 0.4 mM estramustine phosphate, conditions which are known to inhibit tau binding to microtubules. A tau construct that contained only the microtubule binding domains plus 19 amino acids to the C-terminus was fully capable of bundling microtubules. Phosphorylation of tau 3 with cAMP-dependent protein kinase had no effect on its ability to induce microtubule bundling. These results indicate that tau protein is directly capable of bundling microtubules in vitro, and suggests that different tau isoforms differ in their ability to bundle microtubule filaments. 相似文献
65.
B. A. Reikhardt L. M. Belyavtseva O. G. Kulikova 《Bulletin of experimental biology and medicine》1992,113(5):682-684
Academician S. V. Anichkov Department of Pharmacology, Research Institute of Experimental Medicine, Academy of Medical Sciences, St. Petersburg. (Presented by Academician of the Academy of Medical Sciences A. N. Klimov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 113, No. 5, pp. 506–508, May, 1992. 相似文献
66.
Oral administration of myelin basic protein (MBP) inhibits clinical and histopathological manifestations of experimental autoimmune encephalomyelitis (EAE), but only partially reduces serum anti-MBP antibody titers. We report here that orally administered MBP alters the isotypic distribution of anti-MBP antibody-forming cells (AFC) among various lymphoid tissues, with the most profound differences seen in mucosal tissues. We observed an isotype-selective reduction in anti-MBP IgA but not IgM AFC frequencies in Peyer's patches. The anti-MBP IgA AFC frequencies could be reconstituted by addition of interleukin 4 (IL-4) and interleukin 5 (IL-5). The cytokines did not appear to generate de novo responses since no increases in anti-MBP IgA AFC frequencies were observed in control cultures. These results indicate that decreased antibody production, as a result of oral antigen administration, can be reversed by exposure to the appropriate cytokines. 相似文献
67.
N. Glajchen S. Thomas P. Jowell S. Epstein M.D. F. Ismail M. Fallon 《Calcified tissue international》1990,46(1):28-32
Summary The paucity of information on the effect of long-term high-dose salmon calcitonin administration on normal bone mineral metabolism
and histology prompted an investigation of the influence of high-dose synthetic calcitonin in the rat. Serum ionized calcium,
osteocalcin or BGP (bone gla protein), and immunoreactive PTH were measured serially during calcitonin administration and
bone histomorphometry analyzed at 6 weeks (after sacrifice). Daily injections of salmon calcitonin, 0.4 IU/100 g (group B)
and 2 IU/100 g (group C), resulted in significant hypocalcemia at 4 hours for both experimental groups (P<0.004). Serium iPTH was significantly higher over the study period for both groups administered calcitonin. Serum BGP levels
were significantly lower than controls during the study in group C (P<0.002) and to a lesser extent in group B (P<0.05). In group C, bone histomorphometry revealed increased resorption (onteoclast count), decreased trabecular bone volume,
and decreased double-labeled tetracycline surface (bone formation). In group B an increase in osteoclast count but no alteration
in bone formation was observed. To assess the role of PTH in the above findings, high-dose calcitonin was administered to
parathyroidectomized rats. All of the above changes in bone histomorphometry were not observed in this group of animals. In
conclusion, high doses of calcitonin promote hypocalcemia, secondary hyperparathyroidism, and osteoclastosis in the normal
rat in a dose-dependent manner with very high-dose calcitonin impairing bone formation. 相似文献
68.
69.
Daily nutrient intake represents a modifiable determinant of nutritional status in chronic haemodialysis patients. 总被引:2,自引:0,他引:2
Vincenzo Bellizzi Biagio R Di Iorio Vincenzo Terracciano Roberto Minutolo Carmela Iodice Luca De Nicola Giuseppe Conte 《Nephrology, dialysis, transplantation》2003,18(9):1874-1881
BACKGROUND: In maintenance haemodialysis patients, daily food intake is changeable; however, its relationship with nutritional status is unexplored. This study aimed to evaluate the isolated, long-term effect of daily nutrient intake on nutritional status in haemodialysis patients. METHODS: We performed a prospective 1-year controlled study in 27 chronic haemodialysis patients, without recognized risk factors for malnutrition. Each day for 1 week, four times in the year, we measured protein nitrogen appearance, and assessed dietary protein (DPI) and energy (DEI) intake from dietary diaries. We compared the nutritional outcome of patients spontaneously reducing nutrient intake below the threshold of 0.8 g/kg body weight/day for DPI and 25 kcal/kg body weight/day for DEI during the week (LOW, n = 8), with controls at adequate nutrient intake (CON, n = 19). An interventional 6-month study was then carried out in LOW to verify the cause-effect relationship. RESULTS: All patients showed a day-by-day reduction of whole nutrient intake during interdialytic period, which was mostly relevant in the third interdialytic day (L3). During the 1-year study, even in the presence of adequate dialysis dose and normal inflammatory indexes, body weight (68.0 +/- 5.5 to 65.8 +/- 5.9 kg), serum albumin (3.96 +/- 0.07 to 3.66 +/- 0.06 g/dl) and creatinine (9.2 +/- 1.1 to 8.1 +/- 0.7 mg/dl) significantly decreased in LOW but not in CON. Diaries evidenced in LOW a reduced number of meals at L3 that was explained by the fear of excessive interdialytic weight gain. During the interventional study, daily DPI and DEI increased at L3; this was associated with a significant increment of body weight, and serum albumin and creatinine levels. CONCLUSIONS: In maintenance haemodialysis patients the persistent, marked reduction of daily nutrient intake, even if limited to a single day of the week, is an independent determinant of reversible impairment of nutritional status. 相似文献
70.
目的 制备甘草蛋白免疫磁性微球,并建立快速、精确的免疫磁性捕获ELISA法检测甘草蛋白。方法 采用种子聚合法合成聚苯乙烯磁性微球,并以兔抗甘草蛋白IgG抗体致敏,制备特异性捕获甘草特征蛋白的免疫磁性微球。以生物素标记抗体为示踪抗体,结合辣根过氧化物酶标亲和素建立ELISA检测系统,用于甘草药材和含甘草中成药中甘草蛋白的分析。结果 利用该方法对甘草药材和中成药中甘草蛋白抗原检测,检测灵敏度达到10ng/mL。结论 免疫磁性捕获ELISA检测技术方便、快速、准确,为生药的品种鉴定及中成药的质量控制提供一种新方法。 相似文献