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   4121篇
  免费   263篇
  国内免费   12篇
耳鼻咽喉   20篇
儿科学   78篇
妇产科学   36篇
基础医学   586篇
口腔科学   126篇
临床医学   275篇
内科学   1034篇
皮肤病学   59篇
神经病学   304篇
特种医学   145篇
外科学   725篇
综合类   30篇
预防医学   178篇
眼科学   109篇
药学   311篇
中国医学   7篇
肿瘤学   373篇
  2023年   25篇
  2022年   36篇
  2021年   49篇
  2020年   37篇
  2019年   40篇
  2018年   60篇
  2017年   53篇
  2016年   55篇
  2015年   73篇
  2014年   81篇
  2013年   78篇
  2012年   133篇
  2011年   139篇
  2010年   97篇
  2009年   98篇
  2008年   153篇
  2007年   155篇
  2006年   165篇
  2005年   183篇
  2004年   172篇
  2003年   168篇
  2002年   156篇
  2001年   164篇
  2000年   159篇
  1999年   161篇
  1998年   54篇
  1997年   47篇
  1996年   45篇
  1995年   35篇
  1994年   45篇
  1993年   40篇
  1992年   119篇
  1991年   111篇
  1990年   132篇
  1989年   119篇
  1988年   94篇
  1987年   105篇
  1986年   77篇
  1985年   78篇
  1984年   60篇
  1983年   48篇
  1982年   32篇
  1979年   50篇
  1978年   37篇
  1977年   29篇
  1974年   38篇
  1973年   37篇
  1972年   39篇
  1971年   34篇
  1969年   25篇
排序方式: 共有4396条查询结果,搜索用时 0 毫秒
91.
Journal of Medical Ultrasonics - We previously reported that acoustic radiation force impulse (ARFI) with concomitant administration of perfluorobutane as an ultrasound contrast agent (UCA)-induced...  相似文献   
92.
Recently, the right gastroepiploic artery (RGEA) has been used in coronary artery bypass graft (CABG) as an alternative arterial graft. Because of the improvement of prognosis after CABG, malignant diseases are more common in older patients. However, there is a serious problem in patients with gastric cancer after CABG with RGEA graft. In these patients, an interruption of coronary blood supply through the RGEA may cause a life-threatening myocardial ischemia. Therefore, an appropriate strategy is very important to avoid risk while retaining the curability of the operation. We herein describe a 76-year-old Japanese man with advanced gastric cancer who underwent CABG using the RGEA. Abdominal computed tomography (CT) showed #6 lymph nodes (sub-pyloric lymph nodes) metastases surrounding the RGEA. We concluded that curative resection was impossible while preserving the RGEA and started combination chemotherapy using S-1 and cisplatin. After 2 courses of that, #6 lymph nodes were reduced extremely. Thereafter the patient underwent distal gastrectomy with regional lymph node dissection around the RGEA without excision of the RGEA. Histologically, there were no metastases in #6 lymph nodes. Neoadjuvant chemotherapy may be effective for preserving the RGEA graft in a patient with advanced gastric cancer after CABG.Key words: gastric cancer, CABG, RGEA bypass graft, neoadjuvant chemotherapyThe right gastroepiploic artery (RGEA) has been used in coronary artery bypass graft (CABG) surgery.1,2 It is recognized as a reliable conduit with superior long-term patency.35 The right gastroepiploic artery is mainly targeted to the right coronary artery because of the limitation of its length. According to the report of a Japanese association for coronary artery surgery, CABG was carried out in more than 0.1 million patients over a period of 7 years that ended in 2004, and the RGEA has been used in more than half of these patients.6 After CABG for either triple-vessel or left main disease, patients have a 5-year actual survival rate of 92.9% and a cardiac death-free rate of 97.8%.7 Long-term survival increases the opportunity for patients to develop malignant diseases. An increased incidence of gastric cancer after CABG with the use of RGEA has been reported.6 In these patients, an interruption of coronary blood supply through the RGEA may cause a life-threatening myocardial ischemia. Therefore, an appropriate strategy is required to avoid risk while retaining the curative potential of the operation. We present a case of gastric cancer after CABG with the RGEA in which neoadjuvant chemotherapy led to curative operation while preserving the RGEA.  相似文献   
93.
94.
A ligand-binding pocket in the dengue virus envelope glycoprotein   总被引:7,自引:0,他引:7       下载免费PDF全文
Dengue virus is an emerging global health threat. Its major envelope glycoprotein, E, mediates viral attachment and entry by membrane fusion. A crystal structure of the soluble ectodomain of E from dengue virus type 2 reveals a hydrophobic pocket lined by residues that influence the pH threshold for fusion. The pocket, which accepts a hydrophobic ligand, opens and closes through a conformational shift in a beta-hairpin at the interface between two domains. These features point to a structural pathway for the fusion-activating transition and suggest a strategy for finding small-molecule inhibitors of dengue and other flaviviruses.  相似文献   
95.
Clinical evaluation of calcium metabolism in adult T-cell leukemia/lymphoma   总被引:5,自引:0,他引:5  
To clarify the mechanism of development of hypercalcemia in adult T-cell leukemia/lymphoma (ATLL), ten patients with a serum creatinine level less than 177 mumol/L (2 mg/dL) were examined. Although hypercalcemia was seen in only four (40%) of these patients, four of six normocalcemic patients showed hypercalciuria (greater than 5 mmol/d [greater than 200 mg/24 h]). All hypercalcemic patients exhibited high nephrogenous cyclic adenosine monophosphate (NcAMP) levels in the face of low-normal immunoreactive parathyroid hormone and reduced serum 1,25-dihydroxyvitamin D [1,25(OH)2D] concentration. Half of the hypercalciuric patients with normocalcemia also showed high NcAMP and reduced serum 1,25(OH)2D levels. Furthermore, the changes in NcAMP and serum 1,25(OH)2D concentration closely paralleled the development of hypercalcemia and hypercalciuria in two patients. These results are reminiscent of the syndrome of humoral hypercalcemia of malignancy and suggest that derangements in calcium metabolism develop by a similar mechanism in patients with ATLL. The present data also indicate the importance of the measurement of urinary calcium excretion for early detection and prevention of fatal hypercalcemia in patients with ATLL.  相似文献   
96.
97.
98.
Empirical approaches have guided the development of bacterial cultures. The availability of sequenced genomes now provides opportunities to define culture media for growth of fastidious pathogens with computer modelling of metabolic networks. A key issue is the possibility of growing host-dependent bacteria in cell-free conditions. The sequenced Tropheryma whipplei genome was analysed to identify specific metabolic deficiencies. We used this information to design a comprehensive medium that allowed three established T whipplei strains from culture with human cells and one new strain from a clinical sample to grow axenically. Genomic information can, therefore, provide sufficient clues for designing axenic media for fastidious and uncultured pathogens.  相似文献   
99.
100.
We report on molecular and clinical findings in 10 Japanese patients (four males and six females) from eight families (two pairs of siblings and six isolated cases) with Antley-Bixler syndrome accompanied by abnormal genitalia and/or impaired steroidogenesis. Direct sequencing was performed for all the 15 exons of cytochrome P450 oxidoreductase gene (POR), showing two missense mutations (R457H and Y578C), a 24-bp deletion mutation resulting in loss of nine amino acids and creation of one amino acid (L612_W620delinsR), a single bp insertion mutation leading to frameshift (I444fsX449), and a silent mutation (G5G). R457H has previously been shown to be a pathologic mutation, and computerized modeling analyses indicated that the 15A>G for G5G could disturb an exonic splicing enhancer motif, and the remaining three mutations should affect protein conformations. Six patients were compound heterozygotes, and three patients were R457H homozygotes; no mutation was identified on one allele of the remaining one patient. Clinical findings included various degrees of skeletal features, such as brachycephaly, radiohumeral synostosis, and digital joint contractures in patients of both sexes, normal-to-poor masculinization during fetal and pubertal periods in male patients, virilization during fetal life and poor pubertal development without worsening of virilization in female patients, and relatively large height gain and delayed bone age from the pubertal period in patients of both sexes, together with maternal virilization during pregnancy. Blood cholesterol was grossly normal, and endocrine studies revealed defective CYP17A1 and CYP21A2 activities. The results suggest that Antley-Bixler syndrome with abnormal genitalia and/or impaired steroidogenesis is caused by POR mutations, and that clinical features are variable and primarily explained by impaired activities of POR-dependent CYP51A1, CYP17A1, CYP21A2, and CYP19A1.  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