全文获取类型
收费全文 | 14423篇 |
免费 | 1171篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 425篇 |
儿科学 | 456篇 |
妇产科学 | 400篇 |
基础医学 | 2076篇 |
口腔科学 | 326篇 |
临床医学 | 1298篇 |
内科学 | 3002篇 |
皮肤病学 | 248篇 |
神经病学 | 1705篇 |
特种医学 | 394篇 |
外科学 | 1486篇 |
综合类 | 183篇 |
一般理论 | 19篇 |
预防医学 | 1323篇 |
眼科学 | 241篇 |
药学 | 1039篇 |
中国医学 | 20篇 |
肿瘤学 | 994篇 |
出版年
2023年 | 100篇 |
2022年 | 122篇 |
2021年 | 381篇 |
2020年 | 216篇 |
2019年 | 338篇 |
2018年 | 383篇 |
2017年 | 257篇 |
2016年 | 293篇 |
2015年 | 380篇 |
2014年 | 429篇 |
2013年 | 599篇 |
2012年 | 894篇 |
2011年 | 902篇 |
2010年 | 529篇 |
2009年 | 426篇 |
2008年 | 766篇 |
2007年 | 722篇 |
2006年 | 728篇 |
2005年 | 727篇 |
2004年 | 631篇 |
2003年 | 595篇 |
2002年 | 490篇 |
2001年 | 320篇 |
2000年 | 369篇 |
1999年 | 314篇 |
1998年 | 163篇 |
1997年 | 115篇 |
1996年 | 104篇 |
1995年 | 104篇 |
1994年 | 89篇 |
1993年 | 84篇 |
1992年 | 201篇 |
1991年 | 167篇 |
1990年 | 217篇 |
1989年 | 187篇 |
1988年 | 195篇 |
1987年 | 189篇 |
1986年 | 180篇 |
1985年 | 164篇 |
1984年 | 131篇 |
1983年 | 114篇 |
1982年 | 80篇 |
1981年 | 82篇 |
1980年 | 72篇 |
1979年 | 106篇 |
1978年 | 77篇 |
1977年 | 74篇 |
1975年 | 72篇 |
1973年 | 69篇 |
1972年 | 61篇 |
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
91.
D Simeon B Stanley A Frances J J Mann R Winchel M Stanley 《The American journal of psychiatry》1992,149(2):221-226
OBJECTIVE: The goal of this study was to determine whether self-mutilators with personality disorders differ from nonmutilators with personality disorders in impulsivity, aggression, and other psychopathology and whether serotonergic dysfunction contributes to self-mutilation. METHOD: Twenty-six self-mutilators with personality disorders were matched to 26 control subjects with personality disorders for gender, age, education, axis I diagnosis of affective disorder, and axis II diagnosis of personality disorder. Numerous indexes of psychopathology as well as CSF 5-hydroxyindoleacetic acid (5-HIAA) levels and platelet imipramine binding sites (Bmax) and affinity (Kd) were determined. RESULTS: Self-mutilators had significantly more severe character pathology, had greater lifetime aggression, and were more antisocial than the control subjects. The self-mutilators scored higher on the Hamilton Rating Scale for Depression but not on the Beck Depression Inventory or the Beck Hopelessness Scale. The two groups did not differ on the Buss-Durkee Hostility and Guilt Inventory or on the Sensation Seeking Scale. The degree of self-mutilation was significantly correlated with impulsivity, chronic anger, and somatic anxiety. Both self-mutilation and impulsivity showed significant negative correlations with Bmax, although the two groups did not differ in CSF 5-HIAA levels or in platelet imipramine binding. CONCLUSIONS: The results demonstrate the contribution of severe character pathology, aggression, impulsivity, anxiety, and anger to self-mutilation and provide preliminary support for the hypothesis of underlying serotonergic dysfunction facilitating self-mutilation. 相似文献
92.
The purpose of this study was to compare the attitudes toward basic sciences of students in a preclinical problem-based curriculum and a conventional lecture-based curriculum at the end of their second year of medical school. The results showed that the PBL class had more positive attitudes toward basic sciences than students in the conventional class. These results may reflect a learning environment where students meet many scientist role models as teachers and where basic science is learnt in the context of clinical problems. 相似文献
93.
94.
95.
96.
97.
Y. N. Mchra S. B. S. Mann S. P. Dubey A. Verma S. Suri 《Indian journal of otolaryngology and head and neck surgery》1989,41(2):43-47
Due to deep seated location and presence of vital structures, the tumours of the parapharyngeal space poses difficulty in
its early diagnosis, histological nature and surgical extirpation. Modes of radiological assessment in pre-computed tomography
(GT) scan era were sialography of the parotid gland to see whether the tumour is of salivary origin and angiography to note
the vascularity of the tumour. Post CT scan era has changed the assessment protocol. In this article, the authors have tried
to make a comparative evalua?tion between non-contrast GT, GT with systemic contrast and GT sialogram in 14 cases of parapharyngeal
tumours. Angiography was done only when the tumours showed marked enhancement with systemic contrast. Subsequently, 13 patients
underwent surgery for removal of the mass. Application of high-resolution GT helped in not only to see the extent of the tumour
but also to pinpoint the probable histologic nature. 相似文献
98.
Ryohei Kuwatsuru David M. Shames Andreas Mühler Jan Mintorovitch Vladimir Vexler Jeffry S. Mann Frederic Cohn David Price John Huberty Robert C. Brasch M.D. 《Magnetic resonance in medicine》1993,30(1):76-81
Magnetic resonance imaging enhanced with a macromolecular contrast medium (MMCM), albumin-Gd-DTPA, was used to estimate the plasma volume in vivo in the myocardium, lung, liver, and skeletal muscle of 10 normal rats. The plasma volumes of the same tissues in a parallel group of six rats were estimated in vitro by a conventional radioisotopic technique (111In-transferrin). Plasma volumes of myocardium, lung, liver, and skeletal muscle estimated by the MR technique (μl plas. ia cc-1 of tissue) were 101,109,163, and 11.0, respectively, while plasma volumes measured by the In-transferrin radioisotope technique (mg plasma g-1 of tissue) were 78.6, 215,143, and 11-2, respectively. Assuming a ratio of densities of aerated lung to blood of 0.45 and of other tissues to blood of 1.0, correlation between the methods was excellent (R2 = 0.99) indicating that MR imaging enhanced with MMCM permits reliable in vivo estimation of tissue plasma volume in the rat. 相似文献
99.
Summary In two elderly patients with frontal lobe dementia and in two others with progressive aphasia an inverse relationship between the severity of protein deposition and the principal pathology of these disorders was noted. Deposition of protein occurred only in areas of cortex where functional (viable) neurones were still present and was absent where neuronal decimation had taken place. Such findings suggest that the presence of functional neurones is necessary for protein deposition to occur and, therefore, that neurones may be the source of the amyloid protein that is deposited within brain parenchyma not only in these disorders but also in other conditions, particularly Alzheimer's disease.Supported by a grant from the North Western Regional Health Authority (DJ) and a B.Sc Intercalated Studentship from the MRC (PWS) 相似文献
100.
Immunocytochemical profile of neurofibrillary tangles in Down's syndrome patients of different ages 总被引:1,自引:0,他引:1
D M Mann D Prinja C A Davies Y Ihara A Delacourte A Défossez R J Mayer M Landon 《Journal of the neurological sciences》1989,92(2-3):247-260
Brains were obtained at autopsy from 24 patients with Down's syndrome, ranging in age from 13 to 71 years. Neurofibrillary tangle containing neurones of the hippocampus were stained using a Palmgren silver method and immunocytochemically (PAP) using antisera to paired helical filament protein, human tau protein and ubiquitin, as primary antibody. Counts of cells stained by each method were compared. In patients under 50 years of age, in whom only a limited number of tangle bearing cells were present, the number of profiles visualized with silver, anti-paired helical filament and anti-tau methods were similar. However, in patients over 50 years of age (and in certain of those under 50), in whom numerous tangles were present, the number of cell profiles visualized with silver and anti-paired helical filament methods were still similar though anti-tau detected fewer positive cells. This was because of the increased presence, in such patients, of extracellular tangles which had "lost" anti-tau immunoreactivity. Such data suggest that although tau protein forms a major antigenic determinant of neurofibrillary tangles in Down's syndrome (as it does in Alzheimer's disease) this protein may only decorate the basic paired helical filament protein skeleton, and is removed by macrophagic activity upon neuronal death. In all patients, anti-ubiquitin revealed fewer tangles than any other method. It is possible that ubiquitin may be present only transiently, within tangles perhaps following initial formation and lasting only as long as the normal protein degradation processes remain viable within the diseased neurone. 相似文献