全文获取类型
收费全文 | 1321200篇 |
免费 | 100806篇 |
国内免费 | 2173篇 |
专业分类
耳鼻咽喉 | 18774篇 |
儿科学 | 45720篇 |
妇产科学 | 36128篇 |
基础医学 | 188157篇 |
口腔科学 | 34154篇 |
临床医学 | 115843篇 |
内科学 | 266896篇 |
皮肤病学 | 28832篇 |
神经病学 | 105487篇 |
特种医学 | 52220篇 |
外国民族医学 | 660篇 |
外科学 | 200082篇 |
综合类 | 27397篇 |
现状与发展 | 1篇 |
一般理论 | 432篇 |
预防医学 | 100953篇 |
眼科学 | 28460篇 |
药学 | 97463篇 |
2篇 | |
中国医学 | 2503篇 |
肿瘤学 | 74015篇 |
出版年
2019年 | 10710篇 |
2018年 | 14964篇 |
2017年 | 11201篇 |
2016年 | 12273篇 |
2015年 | 13868篇 |
2014年 | 19000篇 |
2013年 | 28594篇 |
2012年 | 39816篇 |
2011年 | 41833篇 |
2010年 | 24734篇 |
2009年 | 23486篇 |
2008年 | 39282篇 |
2007年 | 41905篇 |
2006年 | 42036篇 |
2005年 | 40795篇 |
2004年 | 39681篇 |
2003年 | 38286篇 |
2002年 | 37355篇 |
2001年 | 64162篇 |
2000年 | 66629篇 |
1999年 | 56596篇 |
1998年 | 15447篇 |
1997年 | 13998篇 |
1996年 | 14396篇 |
1995年 | 13609篇 |
1994年 | 12880篇 |
1993年 | 11896篇 |
1992年 | 44615篇 |
1991年 | 43528篇 |
1990年 | 42267篇 |
1989年 | 40160篇 |
1988年 | 36939篇 |
1987年 | 36272篇 |
1986年 | 33652篇 |
1985年 | 32309篇 |
1984年 | 24179篇 |
1983年 | 20310篇 |
1982年 | 11750篇 |
1981年 | 10728篇 |
1979年 | 21357篇 |
1978年 | 14833篇 |
1977年 | 12551篇 |
1976年 | 11701篇 |
1975年 | 12632篇 |
1974年 | 14665篇 |
1973年 | 14124篇 |
1972年 | 12947篇 |
1971年 | 11733篇 |
1970年 | 11051篇 |
1969年 | 10027篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
Thirty-four epileptic patients, aged 9 to 36, were submitted to A/EEG between May 1987 and July 1988. All patients had a thorough clinical and EEG work-up including long-term conventional EEG, afternoon polygraphic sleep recording and, in some cases, full-night EEG and video monitoring. Patients were divided into 2 groups: group I included 19 patients (18 with symptomatic partial epilepsy (SPE) and 1 with idiopathic generalized epilepsy (IGE) in whom no seizure had ever been recorded in spite of EEG recordings averaging a total of 16 hrs 10 min, awake and asleep); group II included 15 subjects (6 with SPE, 5 with IGE, 3 with symptomatic GE and 1 with undetermined epilepsy) in whom one or several seizures had been recorded. A/EEG was performed in order to: 1) obtain better clinical and EEG characterization of seizures, 2) study the circadian distribution of seizures, 3) verify the efficacy of drug treatment and, 4) establish the epileptic or non-epileptic nature of some ictal events. The results of A/EEG were considered positive in 52.63% of group I patients and in 93.33% of group II patients. The authors discuss the specific advantages of A/EEG vs conventional EEG: recording of seizures with random occurrence, of seizures accompanied by falls, checking the remission of seizures. 相似文献
994.
Inhibition of the replication of hepatitis B virus by the carbocyclic analogue of 2''-deoxyguanosine. 总被引:10,自引:2,他引:8 下载免费PDF全文
P M Price R Banerjee G Acs 《Proceedings of the National Academy of Sciences of the United States of America》1989,86(21):8541-8544
We report that treatment of 2.2.15, a human hepatoblastoma-derived cell line in which hepatitis B virus is actively replicating, with the carbocyclic analogue of 2'-deoxyguanosine [Shealy, Y. F., O'Dell, C. A., Shannon, W. M. & Arnett, G. (1984) J. Med. Chem. 27, 1416-1421] resulted in the nearly complete cessation of viral replication, as monitored by the absence of both intracellular episomal and secreted viral DNAs and by the absence of viral DNA polymerase activity. The drug was nontoxic in concentrations up to 200 times the minimum effective inhibitory concentration. 相似文献
995.
996.
Gastrin releases a blood calcium-lowering peptide from the acid-producing part of the rat stomach. 总被引:5,自引:0,他引:5 下载免费PDF全文
P Persson R Hkanson J Axelson F Sundler 《Proceedings of the National Academy of Sciences of the United States of America》1989,86(8):2834-2838
Gastrin-17 induces hypocalcemia in the rat without stimulating calcitonin release. The gastrin-induced hypocalcemia persisted after thyroparathyroidectomy or parathyroidectomy. In contrast, gastrectomy or extirpation of the acid-producing part of the stomach prevented the hypocalcemic effect, suggesting the involvement of the proximal stomach in the gastrin-evoked lowering of blood calcium. The drop in blood calcium upon injection of gastrin-17 did not reflect a loss of calcium via the gastric juice or via the urine. Extracts of the acid-producing mucosa of the rat stomach had a hypocalcemic effect. The extracts were purified by gel chromatography and reversed-phase high-performance liquid chromatography. Digestion with leucine aminopeptidase destroyed the hypocalcemic activity, while trypsin had no effect, suggesting a peptide (or peptides) with an unprotected NH2 terminus and without basic amino acid residues (or with protected basic amino acids). Both gastrin-17 and the mucosal extract stimulated the uptake of 45Ca into bone (radius and sternum). Gastrin-17 was without effect in rats that had undergone gastrectomy, while the mucosal extract was equally effective in gastrectomized and unoperated rats. We suggest that the effects of gastrin-17 on blood calcium and on calcium transfer into bone are indirect and that gastrin-17 stimulates the release of a peptide hormone, tentatively named gastrocalcin, from the acid-producing mucosa of the stomach. Gastrocalcin stimulates the uptake of 45Ca into bone, thereby causing hypocalcemia. 相似文献
997.
Three different sensory loss tests, for anaesthesia to light touch, for diminished pain sensation and for loss of thermosensation, were compared with histopathological examination results in the diagnosis of suspected tuberculoid leprosy in 120 individuals with 126 lesions. Though none of the 3 tests used in this study was found to be strikingly superior to any of the others, the results indicate potentially important differences in their usefulness in different subgroups of suspected patients. The methodological problems inherent in such studies are discussed. 相似文献
998.
Glucocorticoid effects on kainic acid-induced motor seizures and wet dog shakes in rats were investigated by adrenalectomy and dexamethasone treatment. One-day adrenalectomy attenuated kainic acid-induced wet dog shakes and seizure activity. These effects were restored by dexamethasone. Administration of dexamethasone to non-adrenalectomized rats potentiated kainic acid-induced wet dog shakes and severity of seizure activity. These results suggest that glucocorticoids may play an important role in modulating the severity of kainic acid-induced seizures and wet dog shakes. 相似文献
999.
Quantitative autoradiographic analysis was used to identify regions in the brain of the male primate where androgen binding sites may be involved in the actions of testosterone. Three days after castration, adult male rhesus monkeys received a subcutaneous injection of either dihydrotestosterone propionate (DHTP, 20 mg, n = 6), testosterone propionate (TP, 100 mg, n = 2), or oil vehicle (control males, n = 4). Three hours later, 5 mCi [3H]testosterone was administered as an i.v. bolus. At 60 min, brains were rapidly removed and the left halves were used for autoradiography. In control males, highest percentages of labeled neurons (20-84% using a rigorous Poisson criterion) were observed in the ventromedial, arcuate and premammillary nuclei (n.) of the hypothalamus, medial preoptic n., bed n. of stria terminalis, intercalated mammillary n., lateral septal n. and the medial, cortical and accessory basal n. of the amygdala. Pretreatment with DHTP eliminated labeling in androgen target tissues of the genital tract, and reduced the percentages of labeled neurons to 4-22% of control values in the arcuate, lateral septal, premammillary and intercalated mammillary n., indicating that in these regions testosterone acted predominantly at androgen binding sites. However, in the medial preoptic n., the ventromedial hypothalamic n. and the accessory basal amygdaloid n., DHTP pretreatment resulted in much less blocking which, together with other data, suggested that in these sites, testosterone's actions involved aromatization and interaction with estrogen-binding sites. 相似文献
1000.
P K Kohl 《Zeitschrift für Hautkrankheiten》1989,64(5):403-405
Modern identification of Neisseria gonorrhoeae may be either accomplished by direct detection of gonococcal antigen, i.e. without microbiological culturing, or, following culturing, by rapid culture confirmation. The direct detection of gonococcal antigen in an enzyme immuno-assay (Gonozyme) shows reduced specifity especially with mixed microbial flora, and decreased sensitivity with small numbers of organisms. Culture confirmation may be achieved by a rapid sugar degradation test (API----quadFERM+), by specific enzyme detection using chromogenic substrates (Gonochek II), or by demonstration of protein I specific for Neisseria gonorrhoeae by means of monoclonal antibodies (Mikrotrak, Phadebact monoclonal GC, Gonogen II). Detection of protein I is highly sensitive and specific in both the tests of immunofluorescence and coagglutination. 相似文献