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   182251篇
  免费   1354篇
  国内免费   23篇
耳鼻咽喉   1229篇
儿科学   7258篇
妇产科学   3330篇
基础医学   17217篇
口腔科学   1658篇
临床医学   12641篇
内科学   32021篇
皮肤病学   803篇
神经病学   16621篇
特种医学   9064篇
外科学   30256篇
综合类   2566篇
一般理论   2篇
预防医学   18324篇
眼科学   3222篇
药学   9790篇
中国医学   645篇
肿瘤学   16981篇
  2023年   54篇
  2021年   270篇
  2020年   140篇
  2019年   202篇
  2018年   22148篇
  2017年   17504篇
  2016年   19686篇
  2015年   1076篇
  2014年   1065篇
  2013年   1074篇
  2012年   7378篇
  2011年   21397篇
  2010年   19068篇
  2009年   11690篇
  2008年   19801篇
  2007年   22056篇
  2006年   896篇
  2005年   2439篇
  2004年   3572篇
  2003年   4542篇
  2002年   2653篇
  2001年   470篇
  2000年   612篇
  1999年   342篇
  1998年   277篇
  1997年   250篇
  1996年   129篇
  1995年   136篇
  1994年   125篇
  1993年   88篇
  1992年   127篇
  1991年   176篇
  1990年   192篇
  1989年   142篇
  1988年   121篇
  1987年   111篇
  1986年   101篇
  1985年   132篇
  1984年   74篇
  1983年   76篇
  1982年   63篇
  1980年   73篇
  1979年   82篇
  1978年   53篇
  1977年   50篇
  1974年   61篇
  1970年   50篇
  1969年   53篇
  1938年   60篇
  1932年   56篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.

Background  

The fibromyalgia syndrome (FMS) is suggested to be a manifestation of depression or affective spectrum disorder. We measured the cognitive style of patients with FMS to assess personality styles in 44 patients with fibromyalgia syndrome (FMS) by comparing them with 43 patients with major depressive disorder (MDD) and 41 healthy controls (HC).  相似文献   
82.
83.
84.
Background Transarterial chemoemobolization (TACE) is commonly used to treat metastatic carcinoid tumors; however, the management of progressive disease is less clear. We sought to determine if patients with disease progression after TACE would benefit from repeat TACE. Methods The records of 27 patients undergoing repeat TACE for radiologic or symptomatic progression after TACE for metastatic carcinoid were reviewed and compared to 122 undergoing first TACE. Overall and progression-free survivals were estimated by the Kaplan–Meier method. Results Mean disease-free interval after first TACE was 11.8 months. Radiologic response was observed in 61% compared to 82% after first TACE (p = 0.058); hormone response in 64% compared to 80% (p = 0.159); and symptomatic response in 77% compared to 92% (p = 0.053). The complication rate after repeat TACE was lower than after first TACE (p = 0.03). Median overall survival was similar after repeat (28.1 months) and first TACE (33.3 months) (p = 0.53). Progression-free survival was shorter after repeat TACE but not significantly so. No factor examined could predict survival after repeat TACE. Conclusion Repeat TACE for patients with hepatic carcinoid metastases failing first TACE or having evidence of disease progression is safe and offers a viable treatment option. Presented at the 48th Annual Meeting of The Society for Surgery of the Alimentary Tract, Washington, DC, May, 2007.  相似文献   
85.
Cholangiocarcinomas (CC) frequently demonstrate lymphatic spread. We investigated lymph node (LN) counts after resection of extrahepatic CC and survival based on the SEER 1973–2004 database. Out of 20,068 CC patients, 1,518 individuals were selected based on M0 stage and at least one LN examined. Primary cancer sites included gallbladder (29%), extrahepatic bile ducts (26%), and intrapancreatic/ampullary bile ducts (45%); 42% of patients were LN-positive. The median number of LNs examined was four (range 1–39). Median survival was 37 months for LN-negative and 16 months for LN-positive cancers. Multivariate prognostic variables were the number of positive LNs, primary site, age (all at p < 0.0001), gender (p = 0.002), size (p = 0.005), T category (p = 0.009), and total LN count (or number of negative LNs obtained, p = 0.01). The impact of total LN counts was seen in LN-negative (median survival, 1 vs 10 or more LNs examined: 27 vs 51 months, p = 0.002) and LN-positive disease (10 vs 22 months, p < 0.0001). Survival prediction of extrahepatic CCs is strongly influenced by total LN counts and numbers of negative LNs obtained. Although the resulting incremental benefit is small, dissection and examination of 10 or more LNs should be considered for curative intent resections.  相似文献   
86.
87.
Introduction Choroid plexus cysts can lead to isolation of the lateral ventricles and distension of the third ventricle. We present an ultrasonographic video documentation of an infant with variably shaped and localized choroid plexus cyst of the third ventricle. Case report An infant had periods of increased intracranial pressure with changing dilatation of the first to third ventricle. Cerebral ultrasonography of the not crying boy demonstrated a choroid plexus cyst limply hanging down from the roof of the third ventricle to the beginning of the aqueduct of Sylvius. During crying, the cyst prolapsed from the third into left lateral ventricle and was strangled by the foramen of Monro. Endoscopic cyst fenestration and third ventriculostomy continuously solved the problem of intermittent hydrocephalus occlusus. Conclusion Depending not only on localization and size but also on cyst form and cerebrospinal fluid pressure, a single choroid plexus cyst can cause various obstructions of cerebrospinal fluid pathways.  相似文献   
88.
Introduction Iniencephaly, a neural tube defect involving occiput and inion and combined with rachischisis of the cervical, thoracic spine, and retroflexion position of the head is a very rare congenital abnormality of the fetus–newborn with a 0.1–10 of 10,000 prevalence. This abnormality’s prognosis is thought to be dismal. This abnormality can be associated with other abnormalities such as anencephaly, encephalocele, hydrocephalus, cyclopia, absence of the mandible, cleft lip and palate, cardiovascular disorders, diaphragmatic hernia, renal abnormalities, overgrowth of the arms compared to the legs, and club food and gastrointestinal atresia. Discussion Most of the patients are dead born, and the others die in a few hours. There are only six previously documented long-term survivors. In our case, our patient with iniencephalic signs and findings is still living. She is 2 years old now. We think that this patient presents a mild form of iniencephaly.  相似文献   
89.

Background  

Ankylosing spondylitis is a chronic inflammatory rheumatic disorder which usually begins in early adulthood. The diagnosis is often delayed by many years. MR imaging has become the preferred imaging method for detection of early inflammation of the axial skeleton in ankylosing spondylitis.  相似文献   
90.
OBJECTIVES: The study aimed to review the etiologies of patients who underwent surgery for small bowel obstruction (SBO) and to evaluate the risk factors affecting the early postoperative outcomes. MATERIALS AND METHODS: A case series of 430 patients (252 men) with a mean age of 64.5 years, who underwent 437 operations for SBO, were retrospectively reviewed. RESULTS: Peritoneal adhesions and hernia were the most common causes of SBO, contributing 42.3 and 26.8% of all cases, respectively. Strangulation occurred in 27.7% and caused nonviable bowel in 13.0% of obstructing episodes. Old age (age >/= 70 years), female patient, nonadhesive obstruction, and hernia were the independent significant factors associated with bowel strangulation. The 30-day mortality was 6.5%, and the median postoperative hospital stay was 8 days. Old age, the presence of premorbid pulmonary disease, and malignant obstruction were the independent factors associated with operative mortality. The overall complication rate was 35.5%, and old age was the only significant factor associated with postoperative complications. CONCLUSIONS: Surgery for SBO is still associated with significant mortality and morbidity. As old age is significantly associated with an increased incidence of strangulation, operative mortality, and complications, this group of patients should be managed with extra cautions to avoid unfavorable outcome of surgery.  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