首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1605篇
  免费   109篇
  国内免费   2篇
耳鼻咽喉   8篇
儿科学   44篇
妇产科学   55篇
基础医学   138篇
口腔科学   6篇
临床医学   246篇
内科学   298篇
皮肤病学   5篇
神经病学   151篇
特种医学   76篇
外科学   183篇
综合类   27篇
一般理论   2篇
预防医学   210篇
眼科学   32篇
药学   127篇
肿瘤学   108篇
  2023年   12篇
  2022年   23篇
  2021年   29篇
  2020年   28篇
  2019年   33篇
  2018年   48篇
  2017年   31篇
  2016年   45篇
  2015年   48篇
  2014年   51篇
  2013年   71篇
  2012年   124篇
  2011年   114篇
  2010年   66篇
  2009年   63篇
  2008年   98篇
  2007年   115篇
  2006年   103篇
  2005年   87篇
  2004年   71篇
  2003年   61篇
  2002年   61篇
  2001年   24篇
  2000年   7篇
  1999年   18篇
  1998年   8篇
  1997年   9篇
  1996年   8篇
  1995年   5篇
  1994年   10篇
  1993年   5篇
  1992年   9篇
  1991年   10篇
  1990年   19篇
  1989年   9篇
  1988年   18篇
  1987年   17篇
  1986年   13篇
  1985年   20篇
  1984年   11篇
  1982年   8篇
  1981年   5篇
  1980年   7篇
  1979年   12篇
  1978年   7篇
  1977年   8篇
  1976年   6篇
  1974年   7篇
  1972年   8篇
  1965年   5篇
排序方式: 共有1716条查询结果,搜索用时 15 毫秒
81.
BACKGROUND: Failed back surgery syndrome (FBSS) is a condition in which there is failure to improve satisfactorily after back surgery. It is characterized by intractable pain and various degrees of functional disability after lumbar spine surgery. It is estimated that this complication occurs in 5% to 10% of patients after spinal surgeries. The major causes of FBSS are fibrosis and adhesions, spinal instability, recurrent herniated disk, and inadequate decompression. The purpose of this study is to report on the postsurgical outcome after a redo spinal surgery. METHODS: We prospectively studied 50 patients with FBSS. The underlying pathology was identified and all the patients were treated surgically. Redo surgery was targeted at correcting the underlying pathology: removal of recurrent or residual disk, release of adhesions with neural decompression, and fusion with or without instrumentation. The postsurgical outcome was studied using the Oswestry Disability Questionnaire (ODQ). RESULTS: The average preoperative ODQ mean score was 80.8; the average postoperative ODQ mean score was 36.6 at 1 month and 24.2 at 1 year. Best scores were obtained at 3 months of follow-up in most cases. Successful outcome (>50% pain relief) could be achieved in 92% of the patients at 1 year. CONCLUSION: The current study shows that successful management of patients with FBSS could be achieved with proper patient selection, correct preoperative diagnosis, and adequate surgical procedure targeting the underlying pathology.  相似文献   
82.
83.
Sera from 91 patients with ovarian malignancy were examined by the indirect and the complement fixation fluorescent antibody techniques for the presence of antibodies to ovarian carcinoma antigens using cryostat sections of four ovarian carcinomas as substrates. Four sera stained the cytoplasm of ovarian carcinoma cells, but three of these also reacted with mitochondria and the fourth with microsomes at the same or at higher titers. The staining of ovarian carcinoma by these four sera was abolished by absorption with purified rat liver mitochondria or microsomes, respectively. Thus, no ovarian carcinoma-specific antibodies were demonstrable by the fluorescent antibody technique. The overall incidence of non-organ-specific autoantibodies was increased in patients with ovarian carcinoma.  相似文献   
84.
A patient with a condyloma acuminatum of the bladder is presented. This is a rare manifestation of the lesion. The salient features which characterize the lesion are described, and the differential diagnosis is discussed.  相似文献   
85.
The purpose of this case report is to illustrate food intoxication in infants as a consequence of fennel ingestion. Four cases of methemoglobinemia (MetHb) are presented here. Each patient ate homemade fennel purée a few hours prior to arriving to the emergency department with cyanosis unresponsive to oxygen, in the absence of suspected cyanotic heart disease. All 4 patients received treatment with methylene blue and fully recovered. Our cases emphasize that improper handling and storing of vegetables can lead to life-threatening MetHb.  相似文献   
86.
OBJECTIVE: MR angiography is now an established technique for the evaluation of various arterial structures. With recent developments in hardware, whole-body imaging has become technically feasible. The aim of this study is to describe a technique for whole-body MR angiography using a quadrature body coil and a moving tabletop. CONCLUSION: Whole-body MR angiography is technically feasible and may offer a method of screening for unsuspected disease.  相似文献   
87.
DNA fragmentation in testicular sperm from men with obstructive azoospermia is increased by 4-hour and 24-hour incubations and after cryopreservation with the effect is intensified by post-thaw incubation. Testicular sperm for use in intracytoplasmic sperm injection (ICSI) should be injected without delay.  相似文献   
88.
PURPOSE: The purpose of this study was to assess the effects of induced metabolic alkalosis, via sodium bicarbonate (NaHCO3) ingestion, on muscle metabolism and power output during repeated short-duration cycle sprints. METHODS:: Ten active females (mean +/- SD: age = 19 +/- 2 yr, VO2max = 41.0 +/- 8.8 mL x kg x min ) ingested either 0.3 g x kg NaHCO3 or 0.207 g x kg of NaCl (CON), in a double-blind, random, counterbalanced order, 90 min before performing a repeated-sprint ability (RSA) test (5 x 6-s all-out cycle sprints every 30 s). RESULTS: Compared with CON, there was a significant increase in resting blood bicarbonate concentration [HCO3] (23.6 +/- 1.1 vs 30.0 +/- 3.0 mmol x L ) and pH (7.42 +/- 0.02 vs 7.50 +/- 0.04), but no significant difference in resting lactate concentration [La] (0.8 +/- 0.2 vs 0.8 +/- 0.3 mmol x L ) during the NaHCO3 trial. Muscle biopsies revealed no significant difference in resting muscle [La], pH, or buffer capacity (beta(in vitro)) between trials (P > 0.05). Compared with CON, the NaHCO3 trial resulted in a significant increase in total work (15.7 +/- 3.0 vs 16.5 +/- 3.1 kJ) and a significant improvement in work and power output in sprints 3, 4, and 5. Despite no significant difference in posttest muscle pH between conditions, the NaHCO3 trial resulted in significantly greater posttest muscle [La]. CONCLUSIONS: As NaHCO3 ingestion does not increase resting muscle pH or beta(in vitro), it is likely that the improved performance is a result of the greater extracellular buffer concentration increasing H efflux from the muscles into the blood. The significant increase in posttest muscle [La] in NaHCO3 suggests that an increased anaerobic energy contribution is one mechanism by which NaHCO3 ingestion improved RSA.  相似文献   
89.
We report data on the ability of a patient with Balint's syndrome (GK) to process global information from compound letters. As with other patients with Balint's syndrome, GK was impaired at respond-ing to large, global letters. In Experiment 1 we show that this was due to local capture rather than the absolute size of the stimuli. Also, despite his impairment with global letters, GK showed global inter-ference on local judgements, indicating that some implicit processing took place at the global level. Interestingly, the inability to perceive large global letters was overcome when GK identified a solid, large prime letter prior to the onset of the compound figure (Experiment 2). This priming effect was temporary, and decreased as the interval between the prime and the compound letter increased (Experiment 3). When the prime was an English letter, the effect was maintained even when GK only had to identify the prime's colour, provided a colour-identification block of trials followed rather than preceded a block of trials where prime shapes had to be identified (Experiment 4). In contrast, there was no priming when GK had to identify the colour of English letter primes in a trial block following a block where the task was to identify the colour of Hebrew letter primes (Experiment 5). Overall the data indicate that local capture in Balint's syndrome can be overcome by actively priming a wide attentional window. The results can be interpreted in terms of an interaction between spatial attention and grouping processes that subserves the perception of global compound letters.  相似文献   
90.
Although variation in the level of macrophage infiltration has been reported in uveal melanoma, little is known about the expression of other leucocyte markers. An immuno- histochemistry study of the levels of expression of macrophage and other leucocyte markers, in a series of 10 primary choroidal melanoma biopsies, was undertaken. Biopsies were either fixed immediately in formalin and embedded in paraffin wax or established as short-term cultures. Using single- and double-labelling immunohistochemistry, cultured cells and paraffin sections were analysed for a range of melanoma (HMB45, Melan A, S100 and tyrosinase) and immune cell (CD68, CD163, CD45 and CD1a) markers. All samples expressed at least two known melanoma markers. Infiltrating macrophages were present in the majority of sections. When cultured specimens were studied by double-labelling immunofluorescence, uveal melanoma cells were seen to express macrophage markers or have cross-reactivity with related proteins. Expression of the leucocyte antigen CD45 was observed in three tumours but was not present in any cultured cells, whilst the expression of the dendritic cell marker CD1a was absent from all samples.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号