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   3786篇
  免费   343篇
  国内免费   5篇
耳鼻咽喉   55篇
儿科学   107篇
妇产科学   73篇
基础医学   614篇
口腔科学   69篇
临床医学   510篇
内科学   842篇
皮肤病学   72篇
神经病学   198篇
特种医学   262篇
外科学   434篇
综合类   88篇
一般理论   35篇
预防医学   352篇
眼科学   54篇
药学   244篇
  1篇
中国医学   1篇
肿瘤学   123篇
  2022年   30篇
  2021年   46篇
  2020年   29篇
  2019年   54篇
  2018年   65篇
  2017年   57篇
  2016年   55篇
  2015年   76篇
  2014年   84篇
  2013年   136篇
  2012年   132篇
  2011年   133篇
  2010年   94篇
  2009年   109篇
  2008年   126篇
  2007年   152篇
  2006年   130篇
  2005年   120篇
  2004年   105篇
  2003年   90篇
  2002年   119篇
  2001年   105篇
  2000年   116篇
  1999年   103篇
  1998年   83篇
  1997年   90篇
  1996年   76篇
  1995年   49篇
  1994年   61篇
  1993年   51篇
  1992年   106篇
  1991年   112篇
  1990年   101篇
  1989年   112篇
  1988年   98篇
  1987年   80篇
  1986年   71篇
  1985年   67篇
  1984年   68篇
  1983年   64篇
  1982年   43篇
  1981年   39篇
  1980年   29篇
  1979年   43篇
  1978年   46篇
  1977年   26篇
  1976年   27篇
  1974年   31篇
  1973年   32篇
  1972年   27篇
排序方式: 共有4134条查询结果,搜索用时 0 毫秒
1.
BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare malignant tumour of the skin, with an estimated incidence of 0.8 to five cases per 1 million people per year. OBJECTIVE: To study epidemiological, immunohistochemical and clinical features, delay in diagnosis, type of treatment and outcome of DFSP from 1982 to 2002. METHODS: Using data from the population-based cancer registry, 66 patients with pathologically proved DFSP were included (fibrosarcomatous DFSP were excluded). Each patient lived in one of the four departments of Franche-Comté (overall population of 1 million people) at the time of diagnosis. The main data sources came from public and private pathology laboratories and medical records. The rules of the International Agency for Research on Cancer were applied. RESULTS: The estimated incidence of DFSP in Franche-Comté was about three new cases per 1 million people per year. Male patients were affected 1.2 times as often as female patients were. The trunk (45%) followed by the proximal extremities (38%) were the most frequent locations. DFSP occurred mainly in young adults between 20 and 39 years of age. Mean age at diagnosis was 43 years, and the mean delay in diagnosis was 10.08 years. Our 66 patients initially underwent a radical local excision. Among them, 27% experienced one or more local recurrences during 9.6 years of follow-up. There was one regional lymph node recurrence without visceral metastases. These recurrences were significantly related to the initial peripheral resection margins. We observed a local recurrence rate of 47% for margins less than 3 cm, vs. only 7% for margins ranging from 3 to 5 cm [P=0.004; OR=0.229 (95%, CI=0.103-0.510)]. The mean time to a first local recurrence was 2.65 years. Nevertheless, there was no death due to the DFSP course at the end of the follow-up, and the final outcome was favourable. CONCLUSION: Our study emphasizes the importance of wide local excision with margins of at least 3 cm in order to prevent local recurrence. However, the recent development of inhibitors of signal transduction by the PDGFB pathway should soon modify the surgical strategy, which is often too mutilating.  相似文献   
2.
A report of 500 cases of lumbar anesthesia is submitted with special reference to the incidence of postanesthetic headache, nausea, and vomiting in patients who are ambulatory within a short period after surgery.
1.
1. Postanesthetic headache occurred in 30.6 per cent of the cases; this is a much higher incidence than one finds in most published reports and may be explained upon the basis of the following considerations: cases reported in the literature are not selected cases, but those usually requiring seven to ten days of postoperative bed rest; the cases analyzed in the present study were largely those on whom anorectal operations had been performed, these patients requiring only a short period of recumbency.  相似文献   
3.
The emergence of a near-haploid clone of cells in blast phase chronic myelogenous leukemia is an unusual event. We report such a case and review eight other cases described in the English literature. The significance of the substantial loss of genetic material is discussed as is the phenotypic and genotypic heterogeneity observed in this group of patients.  相似文献   
4.
1. The present study aimed to determine the feasibility of conducting a 5 year cardiovascular outcome trial of the treatment of 6000 elderly hypertensive patients in Australian general practices. 2. General practitioners (GPs) were invited to participate by mail and personal follow-up. Patient records were reviewed to identify subjects for a blood pressure (BP) screening programme. Blood pressure was measured on three occasions and eligible subjects were included if the average BP was 160 mmHg systolic or 90 mmHg diastolic if systolic BP was 140 mmHg. 3. Seven hundred and forty-one GPs were approached and 89 were enrolled in the study (12% of mail invites and 75% of those receiving a personal contact). In 16 practices where screening was completed, 82 000 records were reviewed to identify 4% patients eligible for screening. Twenty-two per cent of eligible subjects attended screening. Of 1938 subjects screened, 180 (9%) had BP 5=160/90 mmHg. Forty-seven percent of subjects (n = 916) were receiving antihypertensive therapy and 184 (20%) were withdrawn from therapy. One hundred and sixteen (63%) of these subjects had BP return to study entry levels within 6 weeks. Fifty-seven newly diagnosed and 81 previously treated subjects were randomized (7% of the screened population). 4. Based on the high participation rate of GPs, the response rate of patients to attend a BP screening programme and the 7% randomization to screening ratio for entry into the study, the ANBP2 pilot study has demonstrated that it is feasible to recruit subjects from Australian general practices to a cardiovascular outcome trial.  相似文献   
5.
6.
The ITI implant system has a background of research and development of over 15 years. It is distinctive in that the implant fixtures are transmucosal from the time of placement, requiring only a single stage in surgical treatment. In a relatively simplified approach to prosthetic management, standard overdenture components and conventional fixed partial denture techniques are used. In this report the assessment, surgical treatment and post-operative management of patients using ITI Bonefit implants are described and early results from 168 consecutive fixtures placed over a period of 3 years indicated.  相似文献   
7.
New insights into potential mechanisms of ischemic preconditioning   总被引:6,自引:0,他引:6  
  相似文献   
8.
A recent study demonstrated that the incidence of new arrhythmias occurring during central venous catheter insertion or exchange was 41% atrial and 25% ventricular arrhythmias (12% couplets or greater). Over-insertion of the guidewire, causing direct stimulation to the right side of the heart, has been postulated to be the causative factor. A new technique that allows the operator to control the length of guidewire inserted was developed. With this technique on a population of hospitalized patients, similar to those in the previous study, the incidence of atrial arrhythmias decreased to 32% and the incidence of ventricular arrhythmias to 6% (single premature ventricular contractions only). Although this new technique has limitations, there was a dramatic improvement in the incidence of cardiac arrhythmias. These results indicate a need for modifications in the available equipment to avoid the infrequent but life-threatening complication of malignant arrhythmia.  相似文献   
9.
Six men were studied during 40 min of cycling exercise to examine the relationship between leg glucose uptake and muscle glycogen concentration. Exercise resulted in significant increases in leg glucose uptake, while muscle glycogen and arterial blood glucose concentrations declined. Arterial plasma insulin levels did not change significantly. There was a significant inverse relationship between muscle glycogen concentration and glucose uptake during exercise which suggests a possible regulatory influence of muscle glycogen on glucose uptake in the early stages of exercise in humans.  相似文献   
10.
A 1.5-year-old male Belgian Malinosis Military Working Dog presented with a 1-month history of intermittent hematuria. Diagnostic ultrasound and contrast radiography demonstrated large blood clots in the urinary bladder and a filling defect in the right renal pelvis. At surgery, clotted blood was present in the right ureter and bladder. Following right nephrectomy, the dog returned to training. One month later, elevations in urea nitrogen and creatinine were noted. Hematuria recurred at 3 months and the dog was found dead in its kennel. Necropsy showed a blood-filled left renal pelvis and ureter.  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