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   1132篇
  免费   111篇
  国内免费   2篇
耳鼻咽喉   3篇
儿科学   31篇
妇产科学   18篇
基础医学   147篇
口腔科学   42篇
临床医学   115篇
内科学   161篇
皮肤病学   27篇
神经病学   86篇
特种医学   115篇
外科学   142篇
综合类   27篇
一般理论   1篇
预防医学   151篇
眼科学   27篇
药学   106篇
肿瘤学   46篇
  2021年   13篇
  2020年   15篇
  2019年   16篇
  2018年   19篇
  2017年   14篇
  2016年   25篇
  2015年   22篇
  2014年   29篇
  2013年   47篇
  2012年   57篇
  2011年   45篇
  2010年   44篇
  2009年   32篇
  2008年   47篇
  2007年   36篇
  2006年   27篇
  2005年   44篇
  2004年   31篇
  2003年   39篇
  2002年   32篇
  2001年   39篇
  2000年   39篇
  1999年   24篇
  1998年   28篇
  1997年   31篇
  1996年   26篇
  1995年   18篇
  1994年   13篇
  1993年   19篇
  1992年   18篇
  1991年   17篇
  1990年   17篇
  1989年   31篇
  1988年   33篇
  1987年   15篇
  1986年   16篇
  1985年   21篇
  1984年   8篇
  1983年   11篇
  1982年   10篇
  1981年   19篇
  1980年   10篇
  1979年   24篇
  1978年   14篇
  1977年   8篇
  1976年   10篇
  1974年   9篇
  1970年   7篇
  1969年   13篇
  1968年   11篇
排序方式: 共有1245条查询结果,搜索用时 0 毫秒
91.
Over a six-year period, 130 patients with medically intractable epilepsy were assessed for possible surgical treatment. Initial assessment comprised full neurological and neuropsychological examination, computed tomographic and magnetic resonance imaging brain scanning, and simultaneous video and surface plus sphenoidal electroencephalographic (EEG) recordings of typical seizures. Forty-one patients (32%) underwent further video and EEG recordings of their seizures with depth (intracerebral) or strip (subdural) electrodes. After these assessments 46 patients (35%) underwent surgery, and follow-up for six months to six years is reported in 41 patients. Of 30 patients who underwent temporal lobe surgery, 21 (70%) are free of seizures and four have had significant seizure reduction, meaning that 83% benefited from surgery. Optimal results were obtained for complex partial seizures when depth electrode recordings were obtained and when abnormal tissue was removed. Six extratemporal resections abolished seizures in two patients, and four others showed worthwhile improvement. Five patients underwent corpus callosotomy, resulting in a worthwhile improvement in three and modest improvement in two patients. No deaths or major complications occurred. It is concluded that surgical intervention can be beneficial for up to 30% of patients with medically intractable epilepsy, and referral of these patients to an appropriate institution is encouraged.  相似文献   
92.
Single layer anastomosis in the upper gastrointestinal tract   总被引:1,自引:0,他引:1  
A total of 466 single layer upper gastrointestinal anastomoses were made in 349 patients during an 11-year period. Six (1.3 per cent) anastomoses leaked. Radiological leakage was seen in one of 24 (4.2 per cent) oesophagogastric/jejunal anastomoses. There were no leaks after 66 gastrojejunal anastomoses; one of 84 (1.2 per cent) gastroduodenal anastomoses leaked and was converted to a gastrojejunal anastomosis. Two of 121 (1.7 per cent) biliary-enteric anastomoses leaked and both were successfully managed without reoperation. Two of 171 (1.2 per cent) enteroenteric anastomoses leaked, both in patients with established intraperitoneal sepsis which proved fatal. Of the 349 patients, 13 (3.7 per cent) died in hospital or within 30 days of operation but in only two was anastomotic leakage implicated. Single layer appositional upper gastrointestinal anastomoses are simple, safe and economic.  相似文献   
93.
A retrospective study was conducted on 148 patients with ulnar neuropathy at the elbow, who underwent surgical treatment between 1981 and 1989. Of the 178 nerves operated on, 105 underwent subcutaneous anterior transposition, and 73 were decompressed without transposition. We compared the surgical results of these two groups, and factors influencing prognosis. Overall, 92% of patients improved postoperatively. Pre-operatively, electrophysiological assessment corresponded well to clinical findings, and to macroscopic findings at operation in 95% of cases. The severity of pre-operative clinical findings, advancing age, duration of symptoms and the presence of intraneural fibrosis did not predict an adverse outcome. A satisfactory outcome in 72% of those decompressed compared with 60% of those who were transposed was not statistically significant. However, there was a lower percentage of those with unsatisfactory results in the decompressed series. Thus, we advise that, except where there is persistent deformity or a mass lesion in the region of the ulnar groove, decompression is the operation of choice.  相似文献   
94.
95.
Objective To investigate the attitudes of pharmacists to the provision of needle‐exchange services (NES) at community pharmacies and, if barriers exist, explore means by which they may be overcome. Setting Twenty‐one community pharmacies across Grampian in North East Scotland during May and June 2005. Method Semi‐structured face‐to‐face interviews conducted with 24 pharmacists. Key findings Newly identified barriers included the negative influence of security staff, a local policy against NES provision and a lack of awareness of other services available for drug users. Conclusion Training packages for all health professionals working with drug users and awareness training for security staff are required if the identified barriers are to be overcome. ‘Hands‐on’ training and experience of NES for pharmacists and their staff should be available. Suggestions made by pharmacists for NES provision in general practitioner surgeries or community hospitals and the development of automated services should be considered.  相似文献   
96.
The potential value of DNA aneuploidy, in distinguishing benign from malignant follicular thyroid neoplasms, was studied. The nuclear DNA content of 65 follicular thyroid neoplasms (52 adenomas and 13 carcinomas) was determined by flow cytometric analysis of paraffin embedded material; in 58 cases preparations were technically satisfactory. In 22 follicular neoplasms DNA analysis was also performed on fresh material obtained by fine needle aspiration of surgical specimens. Cell cycle analysis was performed on both fresh and fixed specimens. An aneuploid DNA profile was found on analysis of fixed tissue in eight of 45 (18 per cent) follicular adenomas and four of 13 (31 per cent) follicular carcinomas. DNA aneuploidy was also found in six of the 22 (27 per cent) fresh preparations from follicular adenomas. The frequency of DNA aneuploidy in apparently benign and malignant follicular neoplasms was similar. Follicular thyroid neoplasia are best regarded as a single entity with a low incidence of local and distant spread. All follicular neoplasia are therefore best excised.  相似文献   
97.
Cell-mediated lympholysis (CML) to trinitrophenyl (TNP)-modified autologous splenic lymphocytes has been recently reported in the mouse (1). Both the sensitization and effector phases of this phenomenon were shown to be T-cell mediated. Effector cell specificity studies indicated that modification of the target cells is a necessary but insufficient requirement for cytolysis, and suggested that altered cell surface components controlled by genes mapping in the mouse major histocompatibility H-2 complex (MHC) are important in the specificity of the cytotoxic reaction (1). In allogeneic models the generation of cytotoxic effector cells has been shown to be preceded or accompanied by immunogen- induced proliferation of responding lymphocytes, i.e. a mixed lymphocyte reaction (MLR) (2-5), although the generation of effectors may not necessarily always be the consequence of extensive cell proliferation (5). If the induction of cytotoxic effector lymphocytes by modified syngeneic spleen cells is characteristic of sensitization with cellular alloantigens, one would expect to find that sensitization with TNP-modified autologous cells would also induce thymidine incorporation by the responding cells in the culture. The present report demonstrates that both stimulation of thymidine incorporation and generation of cytotoxic effector cells are part of the in vitro response to TNP-modified autologous lymphocytes. However, the MLR to TNP- modified autologous cells consistently appeared to be less pronounced when compared with an allogeneic MLR, whereas the cytotoxic activity of the effector cells generated by sensitization against TNP-modified autologous cells was frequently as high as that detected against H-2 alloantigens. These two components of reactivity to “modified self” are verified in several C57BL/10 congenic and B10.A recombinant mouse strains.  相似文献   
98.
Background: Recruitment of progenitors during a large-volume collection, as defined by increasing relative and absolute numbers of progenitors (colony-forming units-granulocyte-macrophage [CFU-GM] of CD34+ cells), has been reported previously. Study Design and Methods: To ascertain whether intra-apheresis recruitment occurs in pediatric patients who have undergone mobilization with chemotherapy and granulocyte-colony-stimulating factor (G-CSF), each hour's portion of a 4-hour leukapheresis was collected into separate bags, and assessed by complete blood count, CFU-GM, and CD34+ cell assays. Seven pediatric patients (median age, 7; range, 2–19) were studied in connection with 2 to 4 collections each, for a total of 21 collections (with hourly samples). The collections lasted for 4 hours, at an inlet rate of 1 to 3 mL per kg per minute, for daily processing totals of 5 to 12 blood volumes. (One blood volume [mL] is estimated by the patient's weight in kg × 70 mL/kg.) Smaller (younger) patients had inlet rates exceeding 2 mL per kg per minute, and larger (older) patients had rates of 1 to 1.5 mL per kg per minute. CFU-GM and CD34+ cell counts obtained each hour of the collection and divided by the first hour's value were compared by nonparametric repeated-measures ANOVA. Results: Second-, third- and fourth-hour CD34+ progenitor cell counts were arithmetically higher than first-hour counts, but the trend did not reach significance (p = 0.1561). Second-hour counts were higher than first-hour counts in the overall analysis (mean ± standard error [SE], 1.00 and 1.39 ± 0.1, respectively; p = 0.0525) and in children older than 5 years (1.00 vs. 1.70 ± 0.30, respectively; p = 0.0259), but not in children younger than 5 years (p = 0.8125). CFU-GM counts did not differ among the 4 hours of collection (p = 0.1717) or between the first and second hour (p = 0.9587). Conclusion: In larger (older) patients, from whom fewer blood volumes were collected, there is a trend toward intra-apheresis recruitment, although less than reported previously. In the smaller (younger) patients, from whom more blood volumes were collected, no trend was observed. Lack of (or submaximal) prior mobilization in previously reported studies may have facilitated intracollection recruitment. Alternatively, the larger number of blood volumes collected from the smaller (younger) patients may have masked intra-apheresis recruitment. The study documents the feasibility of large-volume, 4-hour leukapheresis in pediatric patients.  相似文献   
99.
100.
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