全文获取类型
收费全文 | 351724篇 |
免费 | 21154篇 |
国内免费 | 602篇 |
专业分类
耳鼻咽喉 | 4804篇 |
儿科学 | 11687篇 |
妇产科学 | 11199篇 |
基础医学 | 52290篇 |
口腔科学 | 9024篇 |
临床医学 | 29731篇 |
内科学 | 67001篇 |
皮肤病学 | 7111篇 |
神经病学 | 26312篇 |
特种医学 | 14346篇 |
外国民族医学 | 49篇 |
外科学 | 54780篇 |
综合类 | 8537篇 |
现状与发展 | 1篇 |
一般理论 | 206篇 |
预防医学 | 24578篇 |
眼科学 | 8299篇 |
药学 | 24374篇 |
5篇 | |
中国医学 | 859篇 |
肿瘤学 | 18287篇 |
出版年
2021年 | 3137篇 |
2019年 | 3139篇 |
2018年 | 4650篇 |
2017年 | 3523篇 |
2016年 | 4074篇 |
2015年 | 4637篇 |
2014年 | 6113篇 |
2013年 | 9408篇 |
2012年 | 12403篇 |
2011年 | 13003篇 |
2010年 | 8156篇 |
2009年 | 7397篇 |
2008年 | 11955篇 |
2007年 | 12923篇 |
2006年 | 12698篇 |
2005年 | 12264篇 |
2004年 | 11709篇 |
2003年 | 11187篇 |
2002年 | 10664篇 |
2001年 | 14152篇 |
2000年 | 14454篇 |
1999年 | 12256篇 |
1998年 | 3704篇 |
1997年 | 3341篇 |
1996年 | 3126篇 |
1995年 | 3022篇 |
1994年 | 2756篇 |
1992年 | 8851篇 |
1991年 | 8931篇 |
1990年 | 8707篇 |
1989年 | 8543篇 |
1988年 | 7744篇 |
1987年 | 7513篇 |
1986年 | 7116篇 |
1985年 | 6955篇 |
1984年 | 5159篇 |
1983年 | 4502篇 |
1982年 | 2843篇 |
1979年 | 4747篇 |
1978年 | 3514篇 |
1977年 | 2988篇 |
1976年 | 2721篇 |
1975年 | 3047篇 |
1974年 | 3581篇 |
1973年 | 3587篇 |
1972年 | 3336篇 |
1971年 | 3119篇 |
1970年 | 2992篇 |
1969年 | 2715篇 |
1968年 | 2671篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Prof. Dr. O. Hiort 《Gyn?kologische Endokrinologie》2005,3(3):181-186
Zusammenfassung Intersexualität bezeichnet eine seltene Störung der somatosexuellen Differenzierung mit einer Inzidenz von etwa 2 pro 10.000 Geburten pro Jahr in Deutschland. Dahinter verbergen sich verschiedene Diagnosen einer vermehrten Virilisierung bei 46,XX-Karyotyp oder deutlich verminderter Virilisierung bei 46,XY-Karyotyp. Manchmal werden diese Störungen erst während der Pubertätsentwicklung entdeckt. Dann ist eine rasche Diagnostik zur Prognosestellung notwendig. Bei allen Jugendlichen mit Intersexualität muss das Management während der Pubertät viele Aspekte von der psychosexuellen Begleitung bis hin zur medizinischen Behandlung mit Hormonsubstitution oder Therapie und der Beratung hinsichtlich chirurgischer Maßnahmen enthalten. 相似文献
102.
It is shown that with the holding potentials (Eh) ranging from -50 to -30 mV the amplitudes of the inward Ca current of identified neurons are significantly higher in old (20-24 months) Lymnaea stagnalis molluscs than in adult ones. 相似文献
103.
104.
Two hundred and seventy-seven patients with advanced prostatic cancer were treated by either orchiectomy or oestrogen. During the 2-year follow-up period, the response to treatment was considered more favourable in the oestrogen group, and this response was particularly emphasised in patients with poorly differentiated tumour and metastases at the time of diagnosis. Further evaluations included the cardiovascular side effects of oestrogen therapy. 相似文献
105.
J E Richards A H Parmelee L Beckwith 《Electroencephalography and clinical neurophysiology》1986,64(1):1-11
Power spectral and discriminant analysis techniques were used to compare EEG records obtained at term and at 3 months past term from 5 groups of varying risk and developmental outcome. The groups were: healthy full-terms; healthy pre-terms with normal outcomes; sick pre-terms with normal outcomes; sick pre-terms with delayed development; sick pre-terms with later neurological problems. The EEG samples recorded at term were identified as belonging to the correct subject group at 52-70% accuracy, 20% being chance for 5 groups. The accuracy varied with the 4 classes of EEG patterns used. The individual subjects were also classified into their correct groups with few exceptions. Similar success was obtained with EEG samples selected from recording at 3 months past term. The predominant power spectral discriminating features were changes in intra- and inter-hemispheric coherence, and increased power, particularly in the middle and higher frequency range. Thus, computer analyses of EEG samples, using features not readily identified visually, differentiated risk from non-risk infants and also differentiated infants with substantial neonatal medical complications who have good or poor developmental outcomes. 相似文献
106.
107.
PURPOSE: Two experiments explored the extent to which induced blur, reduced luminance, and reduced visual fields affect drivers' steering performance in a driving simulator. METHODS: In experiment 1, ten young participants (M = 21.2 years) drove at approximately 89 km/h (55 mph) along a curvy roadway while being exposed to blur (0 to + 10 D), luminance (0.003 to 16.7 cd/m), and visual field (1.7 and 150 degrees) manipulations. In experiment 2, a new group of ten young participants (M = 18.5 years) drove while exposed to seven visual field sizes (1.7 to 150 degrees). RESULTS: Steering was sensitive to a reduced field size but not to the blur and luminance challenges. Acuity, on the other hand, was sensitive to the blur and luminance challenges but not to reduced field size. DISCUSSION: In healthy young drivers, steering performance is remarkably robust to severe blur and to extremely low luminances. These results support a key element of the selective degradation hypothesis advanced by Leibowitz and colleagues--that steering abilities are preserved at night even when the ability to recognize objects and hazards is not. Additional research should address the other element of this hypothesis--that drivers fail to appreciate the extent to which their visual abilities are degraded at night. 相似文献
108.
Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 23, No. 5, pp. 540–549, May, 1989. 相似文献
109.
Apparent inactivation of alpha 1-antiproteinase by sulphur-containing radicals derived from penicillamine 总被引:2,自引:0,他引:2
alpha 1-Antiproteinase is the major inhibitor of proteolytic enzymes, such as elastase, in human plasma. Its elastase-inhibitory capacity can be inactivated by exposure to hydroxyl radicals (.OH) generated either by pulse radiolysis or by an Fe3+-EDTA/H2O2/ascorbic acid system. Inactivation of alpha 1-antiproteinase by radiolytically-generated .OH under anoxic conditions was decreased by adding a range of anti-inflammatory drugs to the reaction mixtures, including the thiol compound penicillamine. However, under conditions favouring formation of oxysulphur radicals, protection by thiols such as penicillamine was much decreased. It is proposed that sulphur-containing radicals resulting from attack of biologically-produced oxidants upon penicillamine in the presence of O2 can themselves inactivate alpha 1-antiproteinase, and that such radicals might contribute to the side-effects produced by penicillamine or gold thiol therapy in rheumatoid arthritis. 相似文献
110.
A lawsuit directed by parents at a day care program following an outbreak of infectious disease would most likely be based on the legal theory of negligence--the failure to exercise due care as required by circumstances. In the determination of liability for infectious diseases in child day care, the element of causation is most critical. Did the day care facility's actions or failure to act cause the harm? Another important question is whether an infectious disease can be occupational and under what circumstances. Although worker's compensation laws initially had no provisions for occupational disease, now all states recognize responsibility for them. Awareness of potential problems with legal liability and establishment of procedures to minimize risk are important for day care providers, public health officials, clinicians, and parents. 相似文献