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   40110篇
  免费   2095篇
  国内免费   141篇
耳鼻咽喉   524篇
儿科学   2593篇
妇产科学   698篇
基础医学   4765篇
口腔科学   1112篇
临床医学   2892篇
内科学   7180篇
皮肤病学   1128篇
神经病学   2405篇
特种医学   1181篇
外科学   6032篇
综合类   1290篇
一般理论   17篇
预防医学   2047篇
眼科学   1479篇
药学   4011篇
  1篇
中国医学   353篇
肿瘤学   2638篇
  2023年   329篇
  2022年   960篇
  2021年   1616篇
  2020年   886篇
  2019年   978篇
  2018年   1390篇
  2017年   1011篇
  2016年   1334篇
  2015年   1330篇
  2014年   1969篇
  2013年   2244篇
  2012年   3154篇
  2011年   3069篇
  2010年   1837篇
  2009年   1448篇
  2008年   2050篇
  2007年   2079篇
  2006年   1902篇
  2005年   1685篇
  2004年   1584篇
  2003年   1336篇
  2002年   1152篇
  2001年   777篇
  2000年   707篇
  1999年   591篇
  1998年   266篇
  1997年   213篇
  1996年   219篇
  1995年   186篇
  1994年   154篇
  1993年   131篇
  1992年   351篇
  1991年   340篇
  1990年   359篇
  1989年   329篇
  1988年   286篇
  1987年   241篇
  1986年   236篇
  1985年   228篇
  1984年   176篇
  1983年   124篇
  1982年   70篇
  1981年   76篇
  1980年   70篇
  1979年   109篇
  1978年   71篇
  1977年   88篇
  1976年   66篇
  1973年   62篇
  1971年   60篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Food systems are complex and inhomogeneous in nature. Ultrasonic propagation velocity in the food systems, in this case processed milk cream and vegetable oils, is studied. Ultrasonic properties of the food systems are similar to those of complex biological tissues. The presence of vegetable oil as an adulterant in the processed milk cream is detected with the help of a double-probe-through-transmission ultrasonic technique. The present study helps to maintain quality control of various food systems, particularly with regard to their adulteration, if any.  相似文献   
92.
93.
We report a cast of ossifying fibroma of the nose, arising from the bony septum and extending into the nasophaynx in a 2 yrs. old child presenting with features of obstructed nose.  相似文献   
94.
Background Exploratory laparoscopy is commonly undertaken in patients with highly suspicious biliary and pancreatic lesions to facilitate diagnosis and staging cancer is present. If an unresectable tumor is identified, a second endoscopic procedure may be required do deploy a self-expandable metal stent (SEMS) for palliation. As endoscopic retrograde cholangio pancreatography (ERCP) may be unsuccessful in up to 20% of patients, we evaluated the feasibility and safety of deployment of self-expandable metal stents at the same time as the initial laparoscopy. Patients and Methods A total of 23 eligible patients (8 male and 15 female) with malignant obstruction of the common bile duct underwent deployment of SEMS at laparoscopy. Primary outcome measure was the successful laparoscopic deployment of stent and secondary outcome measure was complications rates. Results Indications for stent deployment were unresectable pancreatic cancer in 18, cholangiocarcinoma in two, neuroendocrine tumor in one and ampullary adenocarcinoma in two patients. The median age was 73 years (range 49–93). Twenty-two of 23 stents were deployed successfully: 17 stents were deployed transcystically and five via a choledochotomy. Median times for laparoscopic exploration and SEMS deployment were 165 min (range 105–230) and 20 min (range 10–50), respectively. Pre- and post-procedures median total bilirubin were 9.4 mg/dl (range 5.4–17.5) and 4.0 (range 2.6–7.1). The median size of the pancreatic mass was 3 cm (range 2–5 cm) and that of the common bile duct (CBD) from 9.2 mm (range 7.2–17.4). The mean duration of laparoscopy was 170 min (range 120–230 min) and that for stent deployment 23 min (range 10–50 min). Complications included bleeding, obstruction, and wound infection. Bleeding occurred on day 7 in two patients and on day 30 in one patient; bleeding occurred at the gastrojejunal anastomosis site and was successfully treated with endoscopic hemostasis. A total of three stent obstructions were identified: one each at 60, 90, and 120 days follow-up. All complications were successfully managed endoscopically. There were a total of seven deaths, six as a result of progressive cancer and one of surgical wound infection and ensuing complications. Conclusion This study demonstrates that laparoscopic deployment of self-expandable metal bile duct stents is feasible and safe. This option appears to be a reasonable option in patients with inoperable malignant obstruction of the distal common bile duct.  相似文献   
95.
Two children out of three siblings of a family presented with tiredness, fatigue, and breathlessness for more than 6 months. Examination of peripheral blood smear, bone marrow aspirate, and a positive acidified serum test (HEMPAS) revealed these children to be a case of congenital dyserythropoietic anemia type II. This case is reported because of its rarity.  相似文献   
96.
Editorial     
Evidence-Based Integrative Medicine -  相似文献   
97.
98.
Abstract A young male motorcyclist presented to the Pelvic Unit with an open-book fracture of his pelvis and an acute obstructed direct inguinal hernia. He was managed operatively and made an excellent recovery. Traumatic abdominal wall hernias are rare. This is a unique combination of injuries that the trauma surgeon should be aware of.  相似文献   
99.
Community-acquired viral respiratory tract infections (RTI) in lung transplant recipients may have a high rate of progression to pneumonia and can be a trigger for immunologically mediated detrimental effects on lung function. A cohort of 100 patients was enrolled from 2001 to 2003 in which 50 patients had clinically diagnosed viral RTI and 50 were asymptomatic. All patients had nasopharyngeal and throat swabs taken for respiratory virus antigen detection, culture and RT-PCR. All patients had pulmonary function tests at regular intervals for 12 months. Rates of rejection, decline in forced expiratory volume (L) in 1 s (FEV-1) and bacterial and fungal superinfection were compared at the 3-month primary endpoint. In the 50 patients with RTI, a microbial etiology was identified in 33 of 50 (66%) and included rhinovirus (9), coronavirus (8), RSV (6), influenza A (5), parainfluenza (4) and human metapneumovirus (1). During the 3-month primary endpoint, 8 of 50 (16%) RTI patients had acute rejection versus 0 of 50 non-RTI patients (p=0.006). The number of patients experiencing a 20% or more decline in FEV-1 by 3 months was 9 of 50 (18%) RTI versus 0 of 50 non-RTI (0%) (p=0.003). In six of these nine patients, the decline in FEV-1 was sustained over a 1-year period consistent with bronchiolitis obliterans syndrome (BOS). Community-acquired respiratory viruses may be associated with the development of acute rejection and BOS.  相似文献   
100.
This review of the current scenario of celiac disease (CD) in India covers both pediatric and adult CD. CD is primarily reported from northern India with isolated case reports from the rest of the country. CD cases among Indian children are associated with multiple DR3-DQ2 haplotypes. Delay in diagnosis is contributed by multiple factors including atypical presentations. Use of serological tests, IgA EMA and anti-tTG antibodies, along with modified ESPGHAN criteria provides a definitive diagnosis of CD. Dietary management is often difficult due to non-availability of labeled and marketed gluten-free foods. A majority of children with CD show normalization of nutrition, substantial improvement in growth parameters and attainment of healthy percentile curves on gluten-free diet. Small bowel histology remarkably improves but does not normalize even after 2-3 years on gluten-free diet. The true burden of the disease should be addressed by large epidemiological studies.  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