全文获取类型
收费全文 | 2374890篇 |
免费 | 195091篇 |
国内免费 | 4209篇 |
专业分类
耳鼻咽喉 | 34266篇 |
儿科学 | 72753篇 |
妇产科学 | 62942篇 |
基础医学 | 334902篇 |
口腔科学 | 67572篇 |
临床医学 | 215565篇 |
内科学 | 468630篇 |
皮肤病学 | 47980篇 |
神经病学 | 200780篇 |
特种医学 | 95962篇 |
外国民族医学 | 886篇 |
外科学 | 360400篇 |
综合类 | 56219篇 |
现状与发展 | 1篇 |
一般理论 | 977篇 |
预防医学 | 190606篇 |
眼科学 | 55470篇 |
药学 | 177533篇 |
4篇 | |
中国医学 | 4367篇 |
肿瘤学 | 126375篇 |
出版年
2018年 | 24213篇 |
2016年 | 20580篇 |
2015年 | 23284篇 |
2014年 | 33541篇 |
2013年 | 50839篇 |
2012年 | 68752篇 |
2011年 | 72289篇 |
2010年 | 42476篇 |
2009年 | 40871篇 |
2008年 | 68773篇 |
2007年 | 73114篇 |
2006年 | 74006篇 |
2005年 | 72044篇 |
2004年 | 69337篇 |
2003年 | 67021篇 |
2002年 | 66267篇 |
2001年 | 112451篇 |
2000年 | 116527篇 |
1999年 | 98335篇 |
1998年 | 27861篇 |
1997年 | 25526篇 |
1996年 | 25447篇 |
1995年 | 24609篇 |
1994年 | 23159篇 |
1993年 | 21556篇 |
1992年 | 79387篇 |
1991年 | 76396篇 |
1990年 | 73581篇 |
1989年 | 70848篇 |
1988年 | 65849篇 |
1987年 | 64802篇 |
1986年 | 61336篇 |
1985年 | 58401篇 |
1984年 | 44224篇 |
1983年 | 37660篇 |
1982年 | 22888篇 |
1981年 | 20334篇 |
1980年 | 19036篇 |
1979年 | 41302篇 |
1978年 | 28985篇 |
1977年 | 24349篇 |
1976年 | 22832篇 |
1975年 | 23968篇 |
1974年 | 29639篇 |
1973年 | 28047篇 |
1972年 | 26228篇 |
1971年 | 24151篇 |
1970年 | 22754篇 |
1969年 | 21090篇 |
1968年 | 19137篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
G N J Tytgat 《Acta chirurgica. Supplement》2002,(587):77-81
A true comparison of long-term medical and surgical treatment in gastro-oesophageal reflux disease (GORD) is impossible as few studies have been carried out with adequate randomisation of the patients and long-term evaluation of quality of life. In general the control of the reflux symptoms is roughly equal with medical and surgical treatment. However, surgery can cause other symptoms such as dysphagia or non-specific epigastric discomfort or pain in some patients, which reduces the overall efficacy in controlling the symptoms. Based on a cost utility analysis, Heudebert et al. came to the conclusion that medical treatment was their preferred strategy for most patients with severe erosive oesophagitis. 相似文献
112.
113.
114.
J?rg Müller Klaus Seppi Nadia Stefanova Werner Poewe Irene Litvan Gregor K Wenning 《Movement disorders》2002,17(5):1041-1045
The frequency and pathophysiology of freezing of gait (FoG) in atypical parkinsonism is unknown. We analysed the frequency of FoG in postmortem-confirmed atypical parkinsonian disorders (APD) comprising corticobasal degeneration (CBD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). Sixty-six patients with pathologically confirmed APD (CBD, n = 13; DLB, n = 14; MSA, n = 15; PSP, n = 24) formed the basis for a multicenter clinicopathological study. Clinical features at first and last clinical visit were abstracted from patient records on standardized forms following strict instructions. At the first visit (median 36 months after symptom onset), 24% of APD had FoG (CBD, 8%; DLB, 21%; PSP, 25%; MSA, 40%). Logistic regression analysis showed a significant association of FoG and urinary incontinence (P = 0.04) at first visit. At last visit, 47% of APD had FoG (CBD, 25%; PSP, 53%; DLB, 54%; MSA, 54%). Clinicopathological correlation based on routine postmortem examination failed to identify a consistent neuropathological substrate of FoG. This study demonstrates that (1) FoG is common in APD, and (2) urinary incontinence is significantly associated with FoG in these disorders. Whether FoG and urinary incontinence share similar neuropathological substrates remains to be determined by future studies. 相似文献
115.
F Boomsma F A van der Hoorn A J Man in 't Veld M A Schalekamp 《Clinica chimica acta; international journal of clinical chemistry》1988,178(1):59-69
We report a reliable method for determining DOPA levels in plasma and cerebrospinal fluid. The method is based on complete conversion of DOPA to dopamine and quantification by HPLC-ECD of the dopamine formed. Lower limit of detection was 0.5 nmol/l. No differences in plasma DOPA levels were found between normal children (0-15 yr, n = 60), normal adults (n = 39) and patients with essential hypertension (n = 40) or Parkinson's disease (no DOPA therapy, n = 30). In normal individuals and in patients with essential hypertension venous plasma levels were higher than arterial levels (10.2 vs 9.3 nmol/l, p less than 0.001, V/A ratio 1.11 (SD 0.08), n = 15). Sympathetic stimuli (standing, tilting, bicycle exercise, tyramine) did not influence DOPA levels. In untreated depressed patients (n = 10) and in non-parkinsonian neurological patients (n = 12) cerebrospinal fluid levels of DOPA were 4.5 (SD 2.4) and 5.2 (SD 1.3) nmol/l respectively. A direct method for the measurement of DOPA by HPLC-ECD after deproteinization of plasma is also described and compared with the conversion method. Good agreement was found when plasma DOPA levels exceeded 0.25 mumol/l (y(conversion method) = 0.943x (direct method) + 0.118; n = 60; r = 0.985). The direct method, because of greater simplicity and the possibility of simultaneous measurement of the DOPA metabolite 3-O-methyldopa, is the method of choice with plasma samples from DOPA-treated patients. In non-DOPA treated individuals the conversion method is superior and has proved to be an accurate and sensitive method for the determination of DOPA levels in plasma and cerebrospinal fluid. 相似文献
116.
Cytokines play a part in the control of cellular growth, differentiation and development. Given such pleiotropic activities, it is not unexpected that the expression of the cytokines is tightly regulated. When cytokine-mediated processes are altered by mutation and/or overexpression of some cytokine or cytokine receptor genes, oncogenic transformation can occur. Oncogenes which derive their transforming potential through this mechanism include sis, which represents the activated form of the platelet-derived growth factor B chain, hst1/K-fgflint-2, which share appreciable homology with the gene family of fibroblast growth factors, fms, which is related to the cell surface receptor for macrophage-colony stimulating factor, and erbB-1, which encodes a truncated form of the epidermal growth factor receptor. Cytokine treatment has resulted in modulation of aberrant oncogene activity in some model systems. 相似文献
117.
118.
119.
J D Picard 《Phlébologie》1988,41(3):539-541
120.
S Hummel J Slapke 《Zeitschrift für die gesamte innere Medizin und ihre Grenzgebiete》1988,43(12):319-323
In any case of acute bronchoconstriction the possibility of an adverse reaction to a drug should be considered. In many of such side reactions no allergic mechanism can be detected. Therefore, they are included into the category of pseudoallergic reactions (PAR). The clinically most important form of drug-induced bronchial asthma, analgesics asthma, belongs to this PAR group. A further risk for asthmatics are intravenous applications of contrast-media for roentgenography which in about 15% induce a severe, sometimes life-threatening pseudo-allergic adverse reaction. In asthmatics, the application of any beta-receptor blocking agents and also the use of parasympathicotonic eye drops for treatment of glaucoma are contraindicated. Paradoxical bronchial constriction following application of antiasthmatics are preponderantly caused by locally irritative actions, less frequently by genuine allergic phenomena or additive intolerance. The most reliable prophylaxis against drug-induced bronchial asthma consists in strong avoidance of all derivatives possibly capable to trigger any intolerance. A respective warning should entered into the emergency passport. 相似文献