全文获取类型
收费全文 | 46667篇 |
免费 | 3502篇 |
国内免费 | 164篇 |
专业分类
耳鼻咽喉 | 701篇 |
儿科学 | 1070篇 |
妇产科学 | 702篇 |
基础医学 | 5744篇 |
口腔科学 | 756篇 |
临床医学 | 5239篇 |
内科学 | 9008篇 |
皮肤病学 | 608篇 |
神经病学 | 4126篇 |
特种医学 | 1802篇 |
外国民族医学 | 2篇 |
外科学 | 8153篇 |
综合类 | 768篇 |
现状与发展 | 1篇 |
一般理论 | 32篇 |
预防医学 | 3746篇 |
眼科学 | 994篇 |
药学 | 3566篇 |
1篇 | |
中国医学 | 75篇 |
肿瘤学 | 3239篇 |
出版年
2023年 | 312篇 |
2022年 | 468篇 |
2021年 | 1222篇 |
2020年 | 644篇 |
2019年 | 1201篇 |
2018年 | 1415篇 |
2017年 | 1021篇 |
2016年 | 1038篇 |
2015年 | 1267篇 |
2014年 | 1855篇 |
2013年 | 2361篇 |
2012年 | 3611篇 |
2011年 | 3871篇 |
2010年 | 2113篇 |
2009年 | 1779篇 |
2008年 | 3103篇 |
2007年 | 3422篇 |
2006年 | 3247篇 |
2005年 | 3094篇 |
2004年 | 2721篇 |
2003年 | 2712篇 |
2002年 | 2413篇 |
2001年 | 374篇 |
2000年 | 249篇 |
1999年 | 361篇 |
1998年 | 489篇 |
1997年 | 342篇 |
1996年 | 304篇 |
1995年 | 311篇 |
1994年 | 253篇 |
1993年 | 208篇 |
1992年 | 164篇 |
1991年 | 144篇 |
1990年 | 143篇 |
1989年 | 157篇 |
1988年 | 139篇 |
1987年 | 124篇 |
1986年 | 102篇 |
1985年 | 131篇 |
1984年 | 146篇 |
1983年 | 128篇 |
1982年 | 162篇 |
1981年 | 138篇 |
1980年 | 155篇 |
1979年 | 79篇 |
1978年 | 88篇 |
1977年 | 60篇 |
1976年 | 51篇 |
1975年 | 52篇 |
1974年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
143.
144.
Brian F O'Donnell Marcia A Wilt Ann Marie Hake Julie C Stout Sandra C Kirkwood Tatiana Foroud 《Movement disorders》2003,18(9):1027-1034
Disturbances of visual cognition, visuomotor performance, and visual memory have been described frequently in Huntington's disease (HD). Early stage visual abnormalities could contribute to these deficits. We evaluated visual processing in 20 control subjects who were non-gene carriers at risk for HD, nine presymptomatic gene-positive subjects, and eight subjects with a recent diagnosis of Huntington's disease. Visual perceptual tests of contrast sensitivity and motion discrimination were used to probe early stage visual processing. Extraocular movements were evaluated in a neurologic examination, and the Digit Symbol test was used to test visual motor performance. Contrast sensitivity did not differ among the three groups. Motion discrimination was impaired in HD subjects but not in the presymptomatic gene carriers when compared to gene noncarriers. Among gene carriers, impaired motion discrimination performance was associated with poorer Digit Symbol performance and extraocular abnormalities. These findings suggest that the early stages of HD are associated with disturbances of motion perception as well as disruptions of visual motor and ocular motor performance. 相似文献
145.
146.
147.
Gastric accommodation and emptying in evaluation of patients with upper gastrointestinal symptoms. 总被引:7,自引:0,他引:7
Albert J Bredenoord Heather J Chial Michael Camilleri Brian P Mullan Joseph A Murray 《Clinical gastroenterology and hepatology》2003,1(4):264-272
BACKGROUND & AIMS: Endoscopy-negative dyspepsia is a common symptom that often is difficult to define in pathophysiologic terms. The aim of this study was to assess the frequency of disordered gastric accommodation and emptying in patients referred with unexplained upper gastrointestinal symptoms. METHODS: A computerized diagnostic index was used to identify all patients, 18-70 years old, who underwent single-photon emission computed tomography (SPECT) to assess gastric accommodation at Mayo Clinic Rochester over a 3-year period. Demographics, clinical features, and results of diagnostic testing, including scintigraphic gastric emptying, were extracted from the electronic record. RESULTS: A total of 214 patients were identified; the primary clinical diagnoses were functional dyspepsia, postfundoplication syndromes, rumination syndrome, and diabetic dyspepsia. Gastric accommodation was impaired in 43% of the whole group: 47% of functional dyspepsia, 44% of postfundoplication syndromes, and 33% of diabetic dyspepsia. Delayed gastric emptying was most prevalent in diabetic dyspepsia, and was accelerated in postfundoplication syndromes groups. Thirty-seven percent of patients had abnormal gastric emptying. The highest prevalence of delayed gastric emptying was in the diabetic dyspepsia and accelerated gastric emptying in postfundoplication syndromes groups. Twenty-five percent of patients with normal gastric emptying had impaired accommodation. Upper-gastrointestinal symptoms were not different in groups based on gastric accommodation or emptying results. CONCLUSIONS: Impaired gastric accommodation is common in patients with unexplained dyspepsia. Symptoms alone cannot predict physiologic disturbances. These noninvasive tests identify single or combined pathophysiologic disturbances and may help to identify subgroups of patients as candidates for more selective pharmacotherapy in the future. 相似文献
148.
149.
150.
Daniel F. Worsley Anthony Y. Fung David B. Coupland Cori G. Rexworthy George P. Sexsmith Brian C. Lentle 《European journal of nuclear medicine and molecular imaging》1992,19(6):441-444
Unlike conventional thallium-201 myocardial imaging, technetium-99m methoxyisobutylisonitrile (MIBI) requires separate stress and rest injections. We prospectively studied 148 consecutive patients referred for myocardial perfusion studies to determine the diagnostic value of rest images once normal exercise or dipyridamole tomographic images had been obtained. In patients referred with no history of previous myocardial infarction in whom the diagnosis of coronary artery disease was suspected, 45 of 109 (41%) patients had normal stress tomographic images. Obtaining rest images did not alter the final interpretation in any of these cases. From this we infer that in patients with normal images after exercise or dipyridamole administration and no past history of myocardial infarction, 99mTc-MIBI rest images are not required. This provides several advantages including increased speed of diagnosis, decreased patient radiation exposure, improved cost efficiency and decreased demand on tomographic camera time.
Offprint requests to: A.Y. Fung 相似文献