全文获取类型
收费全文 | 254984篇 |
免费 | 21487篇 |
国内免费 | 5411篇 |
专业分类
耳鼻咽喉 | 3734篇 |
儿科学 | 4996篇 |
妇产科学 | 3917篇 |
基础医学 | 21788篇 |
口腔科学 | 9209篇 |
临床医学 | 22353篇 |
内科学 | 23521篇 |
皮肤病学 | 2807篇 |
神经病学 | 11632篇 |
特种医学 | 8923篇 |
外国民族医学 | 11篇 |
外科学 | 34075篇 |
综合类 | 37470篇 |
现状与发展 | 10篇 |
一般理论 | 24篇 |
预防医学 | 33599篇 |
眼科学 | 2210篇 |
药学 | 23310篇 |
357篇 | |
中国医学 | 26858篇 |
肿瘤学 | 11078篇 |
出版年
2024年 | 1011篇 |
2023年 | 4717篇 |
2022年 | 8996篇 |
2021年 | 11701篇 |
2020年 | 11399篇 |
2019年 | 12806篇 |
2018年 | 11543篇 |
2017年 | 9987篇 |
2016年 | 9187篇 |
2015年 | 8717篇 |
2014年 | 16732篇 |
2013年 | 17507篇 |
2012年 | 14886篇 |
2011年 | 16139篇 |
2010年 | 13017篇 |
2009年 | 11732篇 |
2008年 | 11012篇 |
2007年 | 11086篇 |
2006年 | 9651篇 |
2005年 | 8376篇 |
2004年 | 6984篇 |
2003年 | 6120篇 |
2002年 | 4716篇 |
2001年 | 3979篇 |
2000年 | 3697篇 |
1999年 | 3003篇 |
1998年 | 2476篇 |
1997年 | 2256篇 |
1996年 | 1868篇 |
1995年 | 1769篇 |
1994年 | 1589篇 |
1993年 | 1405篇 |
1992年 | 1294篇 |
1991年 | 1142篇 |
1990年 | 1017篇 |
1989年 | 936篇 |
1988年 | 873篇 |
1987年 | 770篇 |
1986年 | 714篇 |
1985年 | 1995篇 |
1984年 | 2244篇 |
1983年 | 1408篇 |
1982年 | 1876篇 |
1981年 | 1319篇 |
1980年 | 1132篇 |
1979年 | 1040篇 |
1978年 | 830篇 |
1977年 | 636篇 |
1976年 | 767篇 |
1975年 | 508篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
This retrospective analysis reviews the clinical experience of a major urban referral hospital with diffuse malignant pleural mesothelioma during the 14-year period from 1973 through 1986. Seventy-five cases of definite or equivocal mesothelioma were identified. There were four cases of primary malignant peritoneal mesothelioma, seven cases of benign fibrous mesothelioma, and 64 cases of diffuse malignant pleural mesothelioma. In 43 cases (67%) of diffuse malignant pleural mesothelioma, there was historic evidence of asbestos exposure. In 21 cases (33%), there was no known history of asbestos exposure. An increase in annual incidence of diffuse malignant pleural mesothelioma was observed over the study period, from three cases in 1973 to ten cases in 1986. Despite greater awareness of this disease, the diagnosis remains a difficult one to establish given the nonspecific symptoms, signs and radiographic appearance, variable histologic appearance, and poor diagnostic sensitivity and specificity of thoracentesis and closed pleural biopsy. Thoracotomy, thoracoscopy, and CT-guided needle biopsies gave higher yields and are the diagnostic measures of choice when diffuse malignant pleural mesothelioma is suspected. 相似文献
102.
以23例肾功能不全与20例肾功正常患者的唾液尿素氮、钠、钾、舌面pH值和血液的相应生化检查作对照。结果唾液尿素氮、钾与血尿素氮、钾成正相关性。证实了中医“津血同源”“肾为唾”的理论。 相似文献
103.
Ø. Lidegaard 《Acta neurologica Scandinavica》1987,75(6):427-433
The mortality of cerebrovascular diseases in Denmark was analysed for men and women 15-44 years of age, in a 14-year period before and after the appearance of oral contraceptives (OC) in 1966. 1,670 deaths were registered over 28 years, during which the female incidence of cerebrovascular deaths increased by 19% (P less than 0.025), while the male mortality was unchanged. Women showed a percentage increase in deaths from cerebral thromboembolic attacks (CTA) of 33%, men a fall of 14%. The increase of female CTA deaths was most pronounced in the young fertile group, the age group with a high OC use. A relative risk of CTA of 3.3-4.5 for OC users compared with non-users could explain the CTA trend difference between women and men. No other single risk factor responsible for the observed trends could be identified. Both women and men had a significant increase in the mortality of subarachnoidal hemorrhages, and a significant fall in the mortality of intracerebral hemorrhages. 相似文献
104.
Treatment of PC12 cells with nerve growth factor (NGF) produces a rapid and transient increase in calcium uptake into the cells. The increased uptake is maximal after 5 minutes of NGF treatment, but after 15 minutes of NGF treatment, no such increase can be observed. The effect of NGF is partially inhibited by blockers of L-type calcium channels. K-252a, an alkaloid-like kinase inhibitor that usually is found to inhibit the actions of NGF on PC12 cells, produces an increase in calcium uptake similar to, but smaller than, that seen with NGF. NGF had no effect on calcium release under these conditions. 相似文献
105.
d-Amphetamine, 4-OH amphetamine, and epinephrine have been shown in many behavioral studies to facilitate memory when given post-training. The effect of these drugs on the maintained discharge of cells in the locus coeruleus (LC) was investigated using a route of administration (intraperitoneal) and a log-dose range of these drugs comparable to those used in the behavioral experiments.d-Amphetamine profoundly suppressed maintained discharge: an inhibitory effect was observed at every dose (0.1, 1.0, 10.0 mg/kg). In contrast, only the highest dose of 4-OH amphetamine (8.2 mg/kg) inhibited activity in the LC, and this effect was a modest one. Unlike the amphetamines, epinephrine (500 μ/kg) elevated maintained discharge. These results are discussed in the contex of the hypothesized involvement of the LC in the enhancement of memory by these drugs. 相似文献
106.
基于无线网络及条形码技术的图书排架、定位系统 总被引:3,自引:2,他引:1
王海燕 《中华医学图书情报杂志》2005,15(4):50-52
利用无线网络与条形码技术,建立起图书排架、定位系统,可实现图书排架和图书的准确定位.该系统可有效地解决传统管理方法易产生的乱架和死书问题,提高图书借阅效率并降低管理人员的工作强度. 相似文献
107.
C.M. Reading 《Medical hypotheses》1981,7(8):1105-1108
The aetiology of Klinefelter's Syndrome is not known. The causative factor(s) must explain the hypogonadism, low androgen levels, the disordered carbohydrate metabolism and the commonly associated psychiatric conditions. A biotin deficient/dependent state can account for the above. A biotin deficient Klinefelter's Syndrome patients with the above is described. The possible role of biotin in the primary, secondary and tertiary prevention of Klinefelter's Syndrome needs further research. 相似文献
108.
Beth Hoskins Dudley F. Peeler Kathia Lawson Angie M. Barnes Ing K. Ho 《Brain research bulletin》1991,27(2):279-281
The effects of haloperidol on motor and functioning and cognitive functioning were studied in young (3-5 months old) and aged (20-22 months old) male mice by examining haloperidol-induced catalepsy and haloperidol-induced decrements in performance on a radial arm maze. The aged mice were much more sensitive to these adverse effects of haloperidol than were the young mice. Studies of the distribution of radioactivity from [3H]haloperidol to the brain indicated that the differences in sensitivity to this drug were not due to pharmacokinetic differences. The results demonstrate that mice are suitable for studies of aging-induced changes in the behavioral effects of neuroleptic agents. 相似文献
109.
110.
高等医学院校医学化学教材改革的几点思考 总被引:2,自引:1,他引:1
医学的发展已进入分子水平,医学生必须具有扎实的化学基础才能适应专业学习及临床、科研工作的需要。现行医学化学教材大多沿用几十年前的模式,部分内容陈旧滞后,实用性不强。面对现实,改革势在必行。我们认为,突出重点、注重实用、体现医学特色应作为改革的方向。 相似文献