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   33865篇
  免费   2081篇
  国内免费   236篇
耳鼻咽喉   447篇
儿科学   984篇
妇产科学   1147篇
基础医学   3631篇
口腔科学   1062篇
临床医学   2874篇
内科学   6856篇
皮肤病学   700篇
神经病学   1597篇
特种医学   1218篇
外国民族医学   11篇
外科学   6219篇
综合类   757篇
现状与发展   3篇
一般理论   26篇
预防医学   2615篇
眼科学   855篇
药学   2962篇
中国医学   233篇
肿瘤学   1985篇
  2023年   348篇
  2022年   1112篇
  2021年   1760篇
  2020年   983篇
  2019年   1237篇
  2018年   1626篇
  2017年   1012篇
  2016年   1130篇
  2015年   1175篇
  2014年   1616篇
  2013年   1925篇
  2012年   2752篇
  2011年   2855篇
  2010年   1619篇
  2009年   1211篇
  2008年   1796篇
  2007年   1828篇
  2006年   1680篇
  2005年   1543篇
  2004年   1339篇
  2003年   1195篇
  2002年   1085篇
  2001年   301篇
  2000年   263篇
  1999年   234篇
  1998年   163篇
  1997年   146篇
  1996年   140篇
  1995年   117篇
  1994年   111篇
  1993年   92篇
  1992年   149篇
  1991年   129篇
  1990年   141篇
  1989年   121篇
  1988年   102篇
  1987年   116篇
  1986年   85篇
  1985年   92篇
  1984年   75篇
  1983年   79篇
  1982年   61篇
  1981年   40篇
  1980年   48篇
  1979年   47篇
  1978年   41篇
  1977年   43篇
  1976年   38篇
  1974年   50篇
  1973年   51篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
Objectives  We conducted a study to determine the numbers of susuks (charm needles) and their distribution in the craniofacial region of susuk wearers, and the sex, racial affiliation, and age of the wearers. In addition, we sought to determine whether the presence of susuks posed any potential hazard to patients undergoing magnetic resonance imaging (MRI). Methods  We studied various radiographs of 33 susuk wearers (age range, 33–69 years) and investigated the most common sites of insertion in the craniofacial region. A susuk was also suspended inside a 1.5-T MRI machine to determined whether it was attracted by the machine’s magnet. Results  The largest number of susuks that we observed in the craniofacial region was 39 pins, and susuks were particularly numerous in Malay Muslim women. Other sites with susuks were the maxillofacial region (except the temporomandibular region) and the forehead. The susuks showed no ferromagnetic characteristics. Conclusions  As susuks are made from gold, they are generally biocompatible with human tissue and do not cause problems to their wearers. Gold and the other minor metal constituents found in susuks have no ferromagnetic characteristics and therefore pose no hazard to patients undergoing MRI.  相似文献   
104.
105.
BACKGROUND AND AIM: True smooth-muscle neoplasms of the GI tract have been only rarely studied in the KIT era. Their incidence among other GI mesenchymal tumours and their clinicopathological spectrum have not been sufficiently analysed. MATERIALS AND METHODS: We reviewed all GI mesenchymal lesions at the Pathology Institute of the Nuremberg Clinic Centre from 1994 through 2005. RESULTS: Among 262 lesions, there were 142 GISTs (54%) and 85 true smooth muscle neoplasms (32%). Smooth muscle neoplasms comprised 72 polypoid leiomyomas (78%, 5 oesophageal and 67 colorectal), 10 intramural leiomyomas (11%, 5 oesophageal, 4 gastric and one ileal), two intramural leiomyosarcomas in the sigmoid colon and ileum (2%) and one polypoid leiomyosarcoma involving the stomach, descending colon and the retroperitoneum concurrently. None of the leiomyomas with available follow-up have recurred or metastasised. CONCLUSION: Smooth muscle neoplasms are the second most common mesenchymal neoplasms in the GI tract after GISTs. They may arise either from the muscularis mucosae or proper muscle layer forming polypoid and intramural lesions, respectively. Polypoid leiomyomas are more common in the rectosigmoid, while intramural ones mainly arise in the vicinity of the oesophagogastric junction. Polypoid leiomyomas are sufficiently treated by endoscopic resection, and local surgical excision is the treatment of choice for intramural leiomyomas. Intramural leiomyosarcomas are rare high-grade sarcomas that commonly have infiltrated into the surrounding tissue or metastasised by the time of diagnosis.  相似文献   
106.
Abstract This study reports the first ever national oral health survey of Omani 12-year-olds. Conducted in October 1993, of the 3,435 children examined, 1,438 (41.9%) were caries-free, although regional variations ranged from 24.8% to 61.9%. Overall, the national DMFT averaged 1.53, the majority of caries experienced being in the form of untreated decay, with occlusal surfaces of first permanent molars being the most commonly involved site. Oral hygiene was poor, only 11% of those examined being scored as plaque-free.  相似文献   
107.
The overlooked, retained double J stent   总被引:2,自引:0,他引:2  
A series of 4 patients with long overlooked, retained ureteral stents is presented to illustrate the variable, unpredictable, and at times, hazardous course of such patients. These cases are cited to re-emphasize the need for careful documentation, observation, and follow-up of patients in whom stents are placed.  相似文献   
108.
Following exposure to promastigotes of various Leishmania species, mononuclear cells from non-exposed as well as potentially exposed individuals produced a cytokine response which inhibited intracellular forms of Leishmania aethiopica in a permissive monocytic cell line (THP1). Interferon-gamma (IFN-gamma), was one of the cytokines responsible for this anti-leishmanial effect. IFN-gamma was necessary for inhibition but could not act on its own inhibiting L. aethiopica. Tumor necrosis factor-alpha seemed not to be involved in the anti-L. aethiopica effect. The observed effects were in the absence of endotoxin. The results suggest that the mechanisms of killing of L. aethiopica in human cells may differ from those responsible for inhibition of other Leishmania parasites (such as Leishmania major) in mouse macrophages. Furthermore, that potentially relevant responses to Leishmania antigens may exist in normal individuals.  相似文献   
109.
OBJECTIVE: We wanted to compare the efficacies of 95% ethanol and 20% hypertonic saline (HS) sclerotherapies that were performed in a single session under CT guidance for the management of simple renal cysts. MATERIALS AND METHODS: A prospective series of 74 consecutive patients (average age: 57.6 +/- 8.1 years) with simple renal cysts were enrolled in this study. They were randomized into two groups and 95% ethanol or 20% HS, respectively, corresponding to 25% of the aspiration volume, was injected. Treatment success was determined six months later with follow-up clinical evaluation and performing ultrasonography. RESULTS: The sclerotherapy was accepted as technically successful without major complications in all except two patients who were excluded because of a communication between the simple renal cyst and the pelvicalyceal collecting system. Thirty-six patients in the ethanol group received sclerotherapy with 95% ethanol and 36 patients in the HS group underwent sclerotherapy with 20% HS. The complete regression ratio of the ethanol group was significantly higher (94% versus 72%, respectively) than that of the HS group. There was one patient with partial regression in each group. The failure ratio of the ethanol group was significantly lower (3% versus 25%, respectively) than that of the HS group. CONCLUSION: Ethanol sclerotherapy under CT guidance is a successful and safe procedure and it can be used for the treatment of simple renal cysts. Sclerotherapy with 95% ethanol is more effective than 20% HS sclerotherapy. Sclerotherapy with HS may be an option for patients preferring to undergo a less painful treatment procedure.  相似文献   
110.
OBJECTIVE: The purpose of this study was to examine neurophysiological characteristics of dystonia patients using electromyographic soleus H-reflex methods. METHODS: Thirty normal healthy individuals were compared to 27 patients with focal (cervical) or generalized dystonia. Three H-reflex assessment methods were included: the ratio of maximum H-reflex to direct muscle potential (H/M ratio); vibration inhibition (H(v)/H(c) ratio); and H-reflex recovery curves (HRRC). RESULTS: Average H/M ratios between groups were not statistically significant. The average H(v)/H(c) ratio for the generalized dystonia group was significantly greater than the focal dystonia and normal groups. Average values of the HRRC showed the generalized dystonia group had significantly greater disinhibition than the focal dystonia and control groups during the early inhibition phase. The HRRC for the focal dystonia group was greater than normal and more similar to the generalized dystonia group during the late phases of the recovery curve. The average value of the localized late facilitation phase for the focal dystonia group was significantly greater than the control group and less than the generalized dystonia group. No differences were observed between groups for the average localized late inhibition phase of the recovery curve. CONCLUSIONS: Soleus H-reflex measures identified neurophysiologic differences between generalized dystonia, cervical dystonia and normal conditions. SIGNIFICANCE: This methodology enables analysis of the underlying characteristics of dystonic pathologies using soleus H-reflex methods rather than upper extremity H-reflex techniques.  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