全文获取类型
收费全文 | 2069019篇 |
免费 | 147475篇 |
国内免费 | 4245篇 |
专业分类
耳鼻咽喉 | 27111篇 |
儿科学 | 68143篇 |
妇产科学 | 56344篇 |
基础医学 | 301936篇 |
口腔科学 | 59984篇 |
临床医学 | 183753篇 |
内科学 | 399890篇 |
皮肤病学 | 47647篇 |
神经病学 | 157733篇 |
特种医学 | 77032篇 |
外国民族医学 | 302篇 |
外科学 | 312759篇 |
综合类 | 45430篇 |
现状与发展 | 4篇 |
一般理论 | 622篇 |
预防医学 | 154713篇 |
眼科学 | 49410篇 |
药学 | 153047篇 |
7篇 | |
中国医学 | 5155篇 |
肿瘤学 | 119717篇 |
出版年
2019年 | 15965篇 |
2018年 | 23319篇 |
2017年 | 17672篇 |
2016年 | 19438篇 |
2015年 | 22086篇 |
2014年 | 30415篇 |
2013年 | 44825篇 |
2012年 | 61954篇 |
2011年 | 65699篇 |
2010年 | 38760篇 |
2009年 | 36261篇 |
2008年 | 61315篇 |
2007年 | 65297篇 |
2006年 | 65980篇 |
2005年 | 62863篇 |
2004年 | 60904篇 |
2003年 | 57818篇 |
2002年 | 55987篇 |
2001年 | 107103篇 |
2000年 | 109617篇 |
1999年 | 90566篇 |
1998年 | 23590篇 |
1997年 | 20664篇 |
1996年 | 20979篇 |
1995年 | 19974篇 |
1994年 | 18353篇 |
1993年 | 17020篇 |
1992年 | 68328篇 |
1991年 | 66679篇 |
1990年 | 64466篇 |
1989年 | 61994篇 |
1988年 | 56580篇 |
1987年 | 55405篇 |
1986年 | 51995篇 |
1985年 | 49446篇 |
1984年 | 36342篇 |
1983年 | 30986篇 |
1982年 | 17327篇 |
1979年 | 32648篇 |
1978年 | 22881篇 |
1977年 | 19400篇 |
1976年 | 18268篇 |
1975年 | 19597篇 |
1974年 | 23698篇 |
1973年 | 22648篇 |
1972年 | 21237篇 |
1971年 | 19805篇 |
1970年 | 18416篇 |
1969年 | 17319篇 |
1968年 | 16228篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
S Chinn S H Downs J M Anto M W Gerbase B Leynaert R de Marco C Janson D Jarvis N Künzli J Sunyer C Svanes E Zemp U Ackermann-Liebrich P Burney 《The European respiratory journal》2006,28(4):763-771
The incidence of asthma has been reported to be associated with obesity. An alternative analysis, of net change in prevalence, does not require exclusion of those with asthma at baseline. Follow-up data were obtained from 9,552 participants in the European Community Respiratory Health Survey and the Swiss cohort Study on Air Pollution and Lung Disease in Adults. Incidence of asthma was analysed by proportional hazards regression, and net changes in symptoms and asthma status by generalised estimating equations, by obesity group. Incidence and net change in ever having had asthma were greater in females than in males, and in participants who remained obese compared with those who were never obese (hazard ratio 2.00, 95% confidence interval 1.25-3.20; excess net change 2.8%, 0.4-5.3% per 10 yrs). The effect of being obese on net change in diagnosed asthma was greater in females than in males, but for net change in wheeze without a cold it was greater in males. The present results are consistent with asthma being more frequently diagnosed in females, especially obese females. These findings may help to explain the reports of a stronger association between asthma and obesity in females than in males. 相似文献
92.
Abstract – The aim of this study was to investigate mechano-sensory responses of injured and uninjured incisor teeth. Twenty-five children who had experienced dental trauma, together with age- and gender-matched controls, were studied prospectively. Touch thresholds of incisor teeth from both groups were determined using calibrated sets of von Frey hairs (force range 0.5–10.0 g in 0.5 g increments) using a forced choice staircase method. Forces were applied perpendicular to the buccal enamel surfaces along the midline, 2 mm from the incisal edge. Touch threshold was defined as the lowest force detected in three out of the five occasions. Following statistical analysis, P < 0.05 was considered significant. At initial examination, the touch threshold values of 25 traumatised teeth were significantly greater than the untraumatised controls ( P < 0.001), and these values approached those of the control teeth over 3–12 months ( P > 0.05). Dental trauma was associated with increased touch thresholds in permanent incisor teeth, with recovery toward healthy control values usually occurring between 3–12 months. 相似文献
93.
M. C. van den Heuvel K. P. de Jong M. Boot M. J. H. Slooff S. Poppema A. S. H. Gouw 《American journal of transplantation》2006,6(11):2660-2671
The finer branches of the biliary tree (FBBT) contain a regenerative compartment. We hypothesized that preservation of the FBBT together with its microvasculature will lead to recovery of biliary damage and prolonged preservation of bile ductules during the development of chronic liver allograft rejection. The interlobular bile ducts, portal bile ductules and extraportal biliary cells with and without microvessels were studied in sequential biopsies in five patients who fulfilled the Banff criteria of early chronic rejection (CR) (imminence group). Biopsies of CR patients (n = 12) served as controls. Biopsies were double immunostained with CD34 (microvessels) and cytokeratin 7 (biliary structures). Proliferation and proangiogenic activity were assessed with Ki67 and VEGF-A immunostaining. Severe damage of bile ducts in the imminence group did not progress to significant bile duct loss. This was associated with a high proliferative activity in all biliary structures and preservation of the microvascular compartment. VEGF-A expression was increased in all but the reperfusion biopsies. In conclusion, both regenerative activity of the FBBT and an intact microvascular compartment are associated with less damage of the biliary tree and could therefore be prerequisites for biliary regeneration. 相似文献
94.
Matthew S Lewis Paul Maruff Brendan S Silbert Lis A Evered David A Scott 《Archives of clinical neuropsychology》2006,21(5):421-427
The reliable change index (RCI) expresses change relative to its associated error, and is useful in the identification of post-operative cognitive dysfunction (POCD). This paper examines four common RCIs that each account for error in different ways. Three rules incorporate a constant correction for practice effects and are contrasted with the standard RCI that had no correction for practice. These rules are applied to 160 patients undergoing coronary artery bypass graft (CABG) surgery who completed neuropsychological assessments preoperatively and 1 week post-operatively using error and reliability data from a comparable healthy non-surgical control group. The rules all identify POCD in a similar proportion of patients, but the use of the within subject standard deviation, expressing the effects of random error, as an error estimate is a theoretically appropriate denominator when a constant error correction, removing the effects of systematic error, is deducted from the numerator in a RCI. 相似文献
95.
P F Plouin D L Clement H Boccalon J Dormandy I Durand-Zaleski G Fowkes L Norgren T Brown 《International angiology》2003,22(4):333-339
Atherosclerotic renal artery stenosis (ARAS) may cause hypertension, progressive renal failure, and recurrent pulmonary edema. It typically occurs in high risk patients with coexistent vascular disease elsewhere. Most patients with ARAS are likely to die from coronary heart disease or stroke before end-stage renal failure occurs. Recent controlled trials have shown that most patients undergoing angioplasty to treat renovascular hypertension still need antihypertensive agents 6 or 12 months after the procedure. Nevertheless, the number of antihypertensive agents required to control blood pressure adequately is lower following angioplasty than for medication alone. Trials assessing the value of revascularization for preserving renal function or preventing clinical events are only in the early recruitment phase. Revascularization should be undertaken in patients with ARAS and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or with an increase in plasma creatinine levels during angiotensin-converting enzyme inhibition. With or without revascularization, medical therapy using antihypertensive, hypolipidemic and antiplatelet agents is necessary in almost all cases. 相似文献
96.
97.
Surender Kumar Yachha Rakesh Aggarwal S Srinivas Anshu Srivastava Sanjay K Somani Srivenu Itha 《Indian journal of gastroenterology》2006,25(3):132-135
BACKGROUND: We prospectively evaluated the usefulness of IgA tissue transglutaminase antibodies (IgA tTG) in the initial diagnosis of celiac disease (CD) and compared its diagnostic potential with that of IgA anti-endomysial antibodies (IgA EMA) and anti-IgA and IgG gliadin antibodies (AGA and AGG, respectively). METHODS: Sera of 23 untreated children fulfilling the revised ESPGHAN criteria for diagnosis of CD (Group I; mean age 10.8 y); 19 disease controls (Group II; mean age 8.5 y) presenting with chronic diarrhea, short stature or both; and 22 healthy children (Group III; mean age 8.8 y) were studied. These were tested in a blinded manner for AGA, AGG, IgA tTG (guinea pig as antigen) and IgA EMA. RESULTS: In Group I, IgA EMA was positive in 19, IgA tTG in 17, AGA in 14 and AGG in 17 patients. In Group II, these tests were positive in 1, 0, 2 and 14 patients, respectively and in Group III, in 0, 0, 0 and 1 child, respectively. Analyzing data from Group I and II, IgA EMA, IgA tTG, AGA and AGG had sensitivity rates of 83%, 74%, 61% and 74%, respectively; the specificity rates were 95%, 100%, 89% and 26%; positive predictive values were 95%, 100%, 88% and 55% and negative predictive values were 82%, 74%, 65% and 45%, respectively. CONCLUSION: IgA tTG is useful for the diagnosis of CD, with sensitivity and specificity rates comparable to those of EMA and this test is well suited for use in tropical countries like India. 相似文献
98.
99.
100.