全文获取类型
收费全文 | 76750篇 |
免费 | 5615篇 |
国内免费 | 513篇 |
专业分类
耳鼻咽喉 | 873篇 |
儿科学 | 2305篇 |
妇产科学 | 1500篇 |
基础医学 | 9521篇 |
口腔科学 | 1105篇 |
临床医学 | 7947篇 |
内科学 | 16731篇 |
皮肤病学 | 1514篇 |
神经病学 | 6331篇 |
特种医学 | 2825篇 |
外科学 | 12028篇 |
综合类 | 1526篇 |
一般理论 | 113篇 |
预防医学 | 5070篇 |
眼科学 | 2720篇 |
药学 | 4839篇 |
中国医学 | 346篇 |
肿瘤学 | 5584篇 |
出版年
2023年 | 658篇 |
2022年 | 1186篇 |
2021年 | 2500篇 |
2020年 | 1371篇 |
2019年 | 2057篇 |
2018年 | 2538篇 |
2017年 | 1807篇 |
2016年 | 2015篇 |
2015年 | 2283篇 |
2014年 | 3104篇 |
2013年 | 3686篇 |
2012年 | 5789篇 |
2011年 | 5897篇 |
2010年 | 3281篇 |
2009年 | 2908篇 |
2008年 | 4690篇 |
2007年 | 4709篇 |
2006年 | 4616篇 |
2005年 | 4410篇 |
2004年 | 4114篇 |
2003年 | 3610篇 |
2002年 | 3283篇 |
2001年 | 1356篇 |
2000年 | 1218篇 |
1999年 | 1143篇 |
1998年 | 710篇 |
1997年 | 572篇 |
1996年 | 471篇 |
1995年 | 412篇 |
1994年 | 353篇 |
1993年 | 347篇 |
1992年 | 562篇 |
1991年 | 547篇 |
1990年 | 499篇 |
1989年 | 463篇 |
1988年 | 396篇 |
1987年 | 427篇 |
1986年 | 378篇 |
1985年 | 331篇 |
1984年 | 276篇 |
1983年 | 229篇 |
1982年 | 196篇 |
1981年 | 161篇 |
1980年 | 141篇 |
1979年 | 164篇 |
1978年 | 121篇 |
1977年 | 105篇 |
1976年 | 96篇 |
1975年 | 90篇 |
1972年 | 86篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Patrick Ambrosetti Karim Francis Dominique Weintraub Jonathan Weintraub 《Journal of gastrointestinal surgery》2007,11(6):767-772
We performed a prospective study to analyze the functional results following elective laparoscopic sigmoidectomy for computed
tomography (CT)-proven diagnosis of acute diverticulitis and review the literature. Forty-three of 45 available patients (96%)
who had laparoscopic sigmoidectomy for CT-proven acute diverticulitis answered, after a mean time of 40 months, a questionnaire
exploring new abdominal symptoms, bowel function, and the patient’s own judgement of the surgical outcome. Surgical technique
aimed at removing all the sigmoid by taking down the splenic flexure and do a colorectal anastomosis. Four patients (9%) complained
of new abdominal pain. Bowel function was reported as better for 24 patients (56%), unchanged for 16 patients (37%), and worse
for 3 (7%). Twenty patients (47%) considered their final result as excellent to good, 17 patients (40%) as satisfying, and
6 patients (13%) as mediocre. Male gender, absence of preoperative history compatible with an irritable bowel syndrome, length
of resected sigmoid and residual acute inflammation on histology are statistically predictive of a better postoperative degree
of satisfaction. After elective laparoscopic sigmoidectomy for CT-proven diverticulitis, a great majority of patients are
very satisfied with their postoperative general comfort. 相似文献
102.
Hemovigilance for improvement of blood safety. 总被引:2,自引:0,他引:2
103.
K. L. Chan 《Hernia》2007,11(1):37-40
Background Open repair of recurrent paediatric inguinal hernias (IH) is difficult and there is definite risk of damaging the vas deferens
and testicular vessels during dissection of the previous open herniotomy field. Laparoscopic repair (LR) has the benefit of
avoiding the previous operative site.
Method Records of patients with recurrent IH that had LR after open repair were reviewed and evaluated retrospectively. The results
were compared with data from cases in which the LR method was used in the initial IH repair.
Results From September 2002 to October 2005, four boys and one girl (mean age 58.8 months) were treated in our institution for recurrent
IH after open repair. Operative time, success rate and complications did not show any statistically significant difference
when compared with our previous prospectively collected data for primary repairs.
Conclusion Laparoscopic repair is the preferred operation for recurrent childhood IH after open repair. 相似文献
104.
Jonathan Rabinowitz Michael Davidson Peter Paul De Deyn Ira Katz Henry Brodaty Jiska Cohen-Mansfield 《The American journal of geriatric psychiatry》2005,13(11):991-998
OBJECTIVE: Limited work has addressed the construct validity of the Cohen-Mansfield Agitation Inventory (CMAI) in nursing home patients. The authors tested the CMAI factor structure by use of data from three samples of nursing home patients categorized a priori as having at least mild behavioral and psychological symptoms of dementia. METHODS: CMAI data were from the baseline assessment of three randomized, placebo-controlled trials of risperidone for treating elderly nursing home patients. Exploratory factor analyses were conducted on two trials (N = 304; N = 344), and the results of these exploratory factor analyses were then tested with confirmatory factor analysis by use of data from a third trial (N = 617). RESULTS: Principal-components analysis suggested the presence of four factors: 1) Aggressive Behavior (hitting, kicking, scratching, biting, pushing, grabbing, throwing things, cursing or verbal aggression, spitting, tearing things/destroying property, hurting self or others, screaming); 2) Physically Non-Aggressive Behavior (pacing, trying to get to a different place, general restlessness, inappropriate dressing or disrobing, handling things inappropriately, performing repetitious mannerisms); 3) Verbally Agitated Behavior (complaining, constant requests for attention, repetitive questions, negativism); and 4) Hiding and Hoarding. Confirmatory factor analysis indicated that the four-factor solution was a reasonable fit to the data. CONCLUSION: Four factors emerged on the CMAI in nursing home patients with behavioral and psychological symptoms of dementia. The results obtained converge reasonably with previous publications concerning the factor structure of the CMAI, which, taken together, suggest a fairly robust factor structure for the instrument. 相似文献
105.
106.
107.
Steven D. Forman Jonathan D. Cohen Mark Fitzgerald William F. Eddy Mark A. Mintun Douglas C. Noll 《Magnetic resonance in medicine》1995,33(5):636-647
The typical functional magnetic resonance (fMRI) study presents a formidable problem of multiple statistical comparisons (i.e, > 10,000 in a 128 x 128 image). To protect against false positives, investigators have typically relied on decreasing the per pixel false positive probability. This approach incurs an inevitable loss of power to detect statistically significant activity. An alternative approach, which relies on the assumption that areas of true neural activity will tend to stimulate signal changes over contiguous pixels, is presented. If one knows the probability distribution of such cluster sizes as a function of per pixel false positive probability, one can use cluster-size thresholds independently to reject false positives. Both Monte Carlo simulations and fMRI studies of human subjects have been used to verify that this approach can improve statistical power by as much as fivefold over techniques that rely solely on adjusting per pixel false positive probabilities. 相似文献
108.
Jonathan L. Katz Jeffrey M. Witkin Steven I. Dworkin Linda A. Dykstra Richard B. Carter 《Drug development research》1990,20(1):31-41
Effects of daily administrations of d-amphetamine were studied on key peck responses of pigeons maintained under a multiple fixed-interval 2-min, fixed-ratio 30-responseschedule. Under the fixed-interval schedule, a pause was followed by a transition to increasing rates of responding until food presentation. Under the fixed-ratio schedule, higher sustained rates of responding were maintained. Low to intermediate doses (0.3-1.0 mg/kg) of d-amphetamine changed the temporal patterns and occasionally increased rates of responding under the fixed-interval schedule. Higher doses decreased rates of responding under bothschedules. With daily injections of 1.0 mg/kg d-amphetamine prior to experimental sessions, the effects of this dose on rates and patterns of responding were attenuated, and d-anphetamine dose-effect curves were shifted to the right, primarily under the fixed-ratio schedule. Similar results were obtained with daily presession injections of 5.6 mg/kg d-amphetamine in a second group of pigeons, except that rates of responding under both schedules were decreased by this daily dose, and did not return completely to control values with repeated injections. In a third group of pigeons, 1.0 mg/kg d-amphetamine administered daily, after experimental sessions, did not alter dose-effect functions for d-amphetamine. In a second experiment, pigeons were trained to peck one response key when given 1.0 mg/kg d-amphetamine and a different key when given presession water injections. Increasing doses of d-amphetamine produced incresing percentages of d-amphetamine-key responses. Repeated administration of 5.6 mg/kg d-amphetamine shifted these dose-effect functions to the right one-half log unit. Results suggested that decreases in reinforcement frequency are not a necessary condition for the development of behavioral tolerance to d-amphetamine. 相似文献
109.
Trisomy 8 and, less commonly tetrasomy 8, are karyotypic aberrations found in myeloid malignancies. We describe a unique case of acute myeloid leukemia with partial pentasomy 8 resulting from duplication of isochromosome 8q, and discuss its possible roles in leukemogenesis. 相似文献
110.
Deborah W. Knapp Ralph C. Richardson Gerald D. Bottoms Robert Teclaw Thomas C. K. Chan 《Cancer chemotherapy and pharmacology》1992,29(3):214-218
Summary Piroxicam, a nonsteroidal antiinflammatory drug, was given to 62 dogs bearing naturally occurring tumors in a phase I clinical trial. Dose escalation was performed, with oral doses ranging from 0.5 mg/kg every 48 h (q48h) to 1.5 mg/kg q48h being tested. Dose-limiting gastromestinal irritation/ulceration occurred in all four animals that received 1.5 mg/kg q48h. The maximum tolerated dose was 1 mg/kg q48h. Subclinical renal papillary necrosis occurred in two dogs (initial dosages, 1 and 1.5 mg/kg q48h, respectively). Following dose escalation, an additional group of dogs was treated with 0.3 mg/kg piroxicam q24h per os, the accepted canine dosage prior to this trial. Inclusion of this treatment group enabled evaluation of the toxicity of and tumor response to a daily dosage regimen. No complete remissions occurred in this trial. Partial remission was documented in three of ten dogs exhibiting transitional-cell carcinoma, in three of five animals bearing squamous-cell carcinoma, in one of three dogs displaying mammary adenocarcinoma, and in the one dog that exhibited a transmissible venereal tumor. The results of this study support the additional evaluation of piroxicam in a phase II clinical trial in dogs bearing naturally occurring tumors.This investigation was supported by Pfizer Inc. 相似文献