全文获取类型
收费全文 | 2159367篇 |
免费 | 154150篇 |
国内免费 | 2837篇 |
专业分类
耳鼻咽喉 | 29505篇 |
儿科学 | 70368篇 |
妇产科学 | 59057篇 |
基础医学 | 314887篇 |
口腔科学 | 60368篇 |
临床医学 | 197348篇 |
内科学 | 414210篇 |
皮肤病学 | 47891篇 |
神经病学 | 169077篇 |
特种医学 | 82230篇 |
外国民族医学 | 461篇 |
外科学 | 315804篇 |
综合类 | 44630篇 |
现状与发展 | 3篇 |
一般理论 | 781篇 |
预防医学 | 167104篇 |
眼科学 | 49336篇 |
药学 | 165370篇 |
11篇 | |
中国医学 | 4525篇 |
肿瘤学 | 123388篇 |
出版年
2018年 | 22617篇 |
2017年 | 17509篇 |
2016年 | 19490篇 |
2015年 | 22155篇 |
2014年 | 30631篇 |
2013年 | 45944篇 |
2012年 | 62691篇 |
2011年 | 66572篇 |
2010年 | 38978篇 |
2009年 | 37138篇 |
2008年 | 62584篇 |
2007年 | 66951篇 |
2006年 | 67219篇 |
2005年 | 64971篇 |
2004年 | 62333篇 |
2003年 | 59912篇 |
2002年 | 57921篇 |
2001年 | 104420篇 |
2000年 | 106838篇 |
1999年 | 89666篇 |
1998年 | 23945篇 |
1997年 | 21465篇 |
1996年 | 21657篇 |
1995年 | 20352篇 |
1994年 | 18845篇 |
1993年 | 17701篇 |
1992年 | 69537篇 |
1991年 | 67585篇 |
1990年 | 66036篇 |
1989年 | 63843篇 |
1988年 | 58459篇 |
1987年 | 57044篇 |
1986年 | 54199篇 |
1985年 | 51053篇 |
1984年 | 38057篇 |
1983年 | 32748篇 |
1982年 | 18784篇 |
1981年 | 16725篇 |
1979年 | 35318篇 |
1978年 | 24969篇 |
1977年 | 21554篇 |
1976年 | 19450篇 |
1975年 | 21437篇 |
1974年 | 25623篇 |
1973年 | 25011篇 |
1972年 | 23820篇 |
1971年 | 22298篇 |
1970年 | 20826篇 |
1969年 | 19869篇 |
1968年 | 18170篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
991.
We developed a novel method which enables bloodless exposure of the levator veli palatini muscle in rat in order to investigate the physiological properties of this muscle. The levator veli palatini muscle which is innervated by a branch of the glossopharyngeal nerve showed rhythmic spontaneous movement in rats. Cutting the branch supplying LVP of the glossopharyngeal nerve caused cessation of the spontaneous movement of the levator veli palatini muscle. The spontaneous discharges of the glossopharyngeal nerve were synchronized with those of the phrenic nerve. A mixture of 95% oxygen and 5% room air influenced the efferent discharges from the branch of the glossopharyngeal nerve supplying the levator veli palatini muscle. These findings indicate that the motor nerve supply to the levator veli palatini muscle is the glossopharyngeal nerve, and the levator veli palatini muscle is related to the respiratory system, in particular with inspiration in rats. 相似文献
992.
A family with two members (two generations) exhibiting Turner syndrome is described. Cytogenetic studies on these individuals showed the presence of multiple X chromosome changes. Evidence is presented to show that the maternally inherited X chromosome is the chromosome involved in the structural alterations observed. The effect of a tendency of the maternal X chromosome to break at specific sites on the development of the Turner phenotype and abnormal karyology is discussed. 相似文献
993.
G K Freeman 《The British journal of general practice》1989,39(321):145-147
The influence of receptionists on continuity of care in four group practices was examined. Twenty two receptionists were observed making 543 appointments and afterwards were interviewed about their personal priority for continuity of care. One of the practices ran a personal list system. It was found that the personal list practice attracted more requests for a specific doctor and time which were then more difficult to satisfy. Most receptionists thought it was important that patients should see the same doctor but their influence seemed to be small compared with that of the doctor as expressed in practice policies. Marked variation in demand for individual doctors was seen in two of the practices without a personal list system. 相似文献
994.
Studies were made on whether substance P-, leucine-enkephalin- and 5-hydroxytryptamine (serotonin)-like immunoreactive fibers exert a direct influence on the cremaster motoneurons of the male rat by immunocytochemistry combined with retrograde tracing at the light- and electron-microscopic levels. Horseradish peroxidase was used as a retrograde tracer. Two days after injection of horseradish peroxidase into the genitofemoral nerves, its accumulation in the cremaster motoneurons was demonstrated by the diaminobenzidine-nickel method. On immunocytochemical examination of the same sections immunoreactive end-products were detected by the peroxidase-antiperoxidase method. Two different kinds of reaction products were distinguishable at both the light- and electron-microscopical levels. The horseradish peroxidase-labeled cremaster motoneurons at the L1 and L2 levels of the spinal cord were surrounded by abundant immunoreactive terminals. Examination at the ultrastructural level showed that substance P-like immunoreactive terminals formed synaptic contacts almost exclusively with the proximal dendrites of these horseradish peroxidase-labeled cremaster motoneurons. On the other hand, in the leucine-enkephalin- and serotonin-like boutons, significant numbers of axosomatic contacts with horseradish peroxidase-labeled cells were seen although axodendritic contacts with horseradish peroxidase-labeled cells were predominant. Occasionally, leucine-enkephalin-like immunoreactive fibers with synapses on horseradish peroxidase-labeled neurons formed axoaxonic contacts with other leucine-enkephalin-like axonal terminals. Thus, substance P-, leucine-enkephalin- and serotonin-like fibers clearly regulate the function of cremaster motoneurons monosynaptically. The varied synaptic contacts of these fibers according to the neuroactive substances involved suggest different actions of these substances on the cremaster motoneurons. 相似文献
995.
Michael K. Gardner Elaine Clark Mary Ann C. Bowman Patrick J. Miller 《Alcoholism, clinical and experimental research》1989,13(4):508-511
This study investigated analogical reasoning abilities of alcoholics who had been abstinent from alcohol for at least 1 year. Their performance was compared to that of nonalcoholic controls matched as a group for education, age, and gender. Solution times and error rates were modeled using a regression model. Results showed a nonsignificant trend for alcoholics to be faster, but more error prone, than controls. The same componential model applied to both groups, and fit them equally well. Although differences have been found in analogical reasoning ability between controls and alcoholics immediately following detoxification, we find no evidence of differences after extended periods of sobriety. 相似文献
996.
The aqueous, organic, and volatile oil extracts of leaves of Eugenia uniflora Linn. Family Myrtaceae were investigated for antibacterial properties using agar dilution techniques. The aqueous extract was the most active against the organisms compared to the organic and volatile oil extracts. The extracts were found to inhibit Gram positive Staphylococcus aureus and Bacillus subtilis and Gram negative Escherichia coli and Shigella dysentcriae. Pseudomonas aeruginosa, Klebsiella pneumoniac, and Salmonella typhi were not inhibited. 相似文献
997.
A retrospective analysis of the results of 27,801 cervical smears from one year in a community laboratory was undertaken. This represented 23,820 individual patients. Abnormalities were seen in 9.3% of patients. Three point seven percent of patients had benign abnormalities, 5.5% had cervical intraepithelial neoplasia and 0.1% had major abnormalities. The incidence of cervical epithelial abnormality was highest in the 15-34 age group but major abnormalities were seen most often in the 55+ age group. Human papillomavirus was more commonly seen in the youngest age group. The presence of inflammation was reported in 65% of the smears. Thirty percent of smears had no endocervical cells and 0.6% were grossly inadequate. Fifteen percent of patients had repeat smears and 3% of total smears were judged unnecessary. Forty two point six percent of patients less than 55 years of age in the laboratory population base had a smear but only 7.9% of those over 55. 相似文献
998.
The effect of some tricyclic antidepressants on the inhibition of mouse brain monoamine oxidase in-vivo by phenelzine 总被引:1,自引:0,他引:1
Four tricyclic antidepressants, amitriptyline, imipramine, desipramine and iprindole have been shown to partially protect mouse brain monoamine oxidase in-vivo from the irreversible enzyme inhibition produced by subsequent injection of phenelzine. Levels of protection were similar when the enzyme was assayed with selective substrates (5-hydroxytryptamine and phenethylamine) for both the A and B forms of the enzyme. Although other explanations cannot at this stage be ruled out, these observations are consistent with the tricyclic antidepressants acting as reversible inhibitors of brain monoamine oxidase in-vivo. 相似文献
999.
Addison's disease is rarely caused by metastatic cancer. We report a unique case of hypoadrenalism owing to metastatic transitional cell carcinoma of the bladder. The relevant literature is reviewed. 相似文献
1000.