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   22821篇
  免费   1409篇
  国内免费   213篇
耳鼻咽喉   381篇
儿科学   318篇
妇产科学   297篇
基础医学   3901篇
口腔科学   401篇
临床医学   1884篇
内科学   4494篇
皮肤病学   754篇
神经病学   1954篇
特种医学   1190篇
外科学   3069篇
综合类   86篇
一般理论   4篇
预防医学   866篇
眼科学   491篇
药学   2115篇
中国医学   296篇
肿瘤学   1942篇
  2024年   17篇
  2023年   202篇
  2022年   512篇
  2021年   837篇
  2020年   427篇
  2019年   597篇
  2018年   691篇
  2017年   525篇
  2016年   794篇
  2015年   1013篇
  2014年   1157篇
  2013年   1375篇
  2012年   2036篇
  2011年   1953篇
  2010年   1124篇
  2009年   911篇
  2008年   1409篇
  2007年   1304篇
  2006年   1213篇
  2005年   1097篇
  2004年   953篇
  2003年   829篇
  2002年   725篇
  2001年   426篇
  2000年   401篇
  1999年   337篇
  1998年   156篇
  1997年   120篇
  1996年   111篇
  1995年   98篇
  1994年   77篇
  1993年   65篇
  1992年   100篇
  1991年   99篇
  1990年   78篇
  1989年   73篇
  1988年   74篇
  1987年   66篇
  1986年   51篇
  1985年   52篇
  1984年   36篇
  1983年   41篇
  1982年   26篇
  1981年   19篇
  1980年   24篇
  1979年   38篇
  1978年   19篇
  1976年   16篇
  1972年   15篇
  1969年   15篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
The radiographic findings in 24 cases of bronchiolitis obliterans with organizing pneumonia and 16 cases of usual interstitial pneumonia were reviewed and compared. Some cases of bronchiolitis obliterans with organizing pneumonia have been mistaken for usual interstitial pneumonia, although the two diseases have distinct pathologic findings. Clinically, the diseases often have different manifestations. Bronchiolitis obliterans with organizing pneumonia has a better prognosis and often responds well to steroids. This study shows that the radiologic findings of bronchiolitis obliterans include alveolar opacities without lung-volume loss. Patients with usual interstitial pneumonia, however, have bilateral diffuse interstitial opacities with occasional honeycomb changes, and there is loss of lung volume in most patients. These findings suggest that the chest radiograph can aid in distinguishing the two diseases.  相似文献   
12.
13.
The association of MTHFR and CBS variants with the doubling time and responsiveness to several chemodrugs was analyzed in 26 human cancer xenografts. The tumors homozygous for the absence of insertion (NN) for the CBS 844ins68bp were more chemosensitive than those with insertion (NI) to TS-1 (P=0.0048), suggesting a potential effect of this variant on fluoropyrimidine efficacy. Furthermore, the doubling time of tumors with a variant C allele (AC or CC) in MTHFR-A1298C was significantly longer than that of tumors with a normal allele (AA) (P=0.0008). Twenty-nine cellular proliferation-related genes were associated with MTHFR-A1298C genotyping and with the doubling time.  相似文献   
14.
15.
Reduction mammaplasty by central pedicle flap with short submammary scar   总被引:2,自引:0,他引:2  
Reduction mammaplasty was performed in 30 patients by combining the central pedicle flap method with the short submammary scar (3-S) technique to avoid the common drawbacks of currently popular dermoglandular procedures. Reduction was accomplished by using perforating vascular branches from the pectoralis major muscle and its fascia supplying the nipple and breast parenchyme instead of the subdermal plexus. The central vascular pedicle supplying the nipple-areola complex was preserved. Only the periphery of the breast parenchyme was resected circumferentially, with the exception of the inferolateral portion, so as not to injure the sensory nerve. The remaining breast parenchyme was preserved in an inverted cone shape. The nipple-areola complex was safely transposed with great freedom, and the amount of resection was accurately adjusted for symmetry. No cases of nipple-areola complex sensory change occurred postoperatively, and lactation is possible because of preservation of the lactiferous ducts. The length of postoperative scars was reduced by using the short submammary scar technique. We believe this combined method is ideal in patients requiring resections ranging from 200 to 600 g per breast with good skin elasticity and moderate degree of ptosis.Presented at the Sixth Asian Pacific Congress of the International Confederation for Plastic and Reconstructive Surgery, in Seoul, Korea, October 1993.  相似文献   
16.
17.
Abstract: Juvenile xanthogranuloma is a xanthomatous and granulomatous condition that frequently arises before 1 year of age and mainly occurs on the head and trunk. We report a rare solitary juvenile xanthogranuloma on the right palm of a 10-year-old girl, present for one year. This solitary involvement of the palm has been reported only twice before.  相似文献   
18.
19.
We report an uncommon case of solitary, small hepatic angiosarcoma that was initially considered as a hemangioma. We present the imaging findings, with an emphasis on the initial and follow-up CT and MR findings, as well as report on the more suggestive findings of angiosarcoma than those of a hemangioma.  相似文献   
20.
The reconstruction of large bone and joint defects after the resection of malignant tumors remains a major challenge. Chemotherapy has significantly lowered the risk of metastasic disease, but complications associated with reconstructive techniques continue to result in late morbidity. In the present study, biomechanical torsion testing, gait analysis, and histomorphometric and scanning electron microscopic evaluations of 24 dogs were used to examine the effects of preoperative and postoperative administration of cisplatin on the biologic fixation of a porous-coated segmental replacement prosthesis. The chemotherapy consisted of four cycles of cisplatin administered at a dosage of 75 mg/m:2 preoperatively or postoperatively. The healing was enhanced by use of an autogenous corticocancellous bone graft. The graft was placed evenly around the prosthesis and the adjacent femoral cortex. Mechanical analyses of torsional stiffness, yield strength, and maximum strength revealed no statistically significant differences between the groups at 12 weeks. Such lack of difference was mainly due to the penetration of highly organized fibrous tissue into the porous surface; this provided strong fixation of the implant to bone even in the absence of bone ingrowth. Although bone ingrowth into the prostheses was not affected, electron microscopic, histomorphometric, and radiologic analyses showed a clear difference in the formation of new bone around the prosthesis. Preoperative chemotherapy did not alter the formation of new bone, but specimens from animals treated postoperatively with cisplatin showed significantly less bone graft resorption and less new bone formation. Hence, the effect of cisplatin administration caused only a temporary delay, not a permanent effect, on extracortical capsule formation. The formation of extracortical bone and soft tissue might prevent debris-incised osteolysis and, therefore, prevent late complications by forming a tight capsule around the bone-prosthetic interface.  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