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   958篇
  免费   35篇
  国内免费   7篇
耳鼻咽喉   27篇
儿科学   18篇
妇产科学   10篇
基础医学   104篇
口腔科学   29篇
临床医学   54篇
内科学   247篇
皮肤病学   17篇
神经病学   59篇
特种医学   104篇
外科学   159篇
综合类   1篇
预防医学   13篇
眼科学   15篇
药学   46篇
肿瘤学   97篇
  2023年   9篇
  2022年   10篇
  2021年   33篇
  2020年   15篇
  2019年   13篇
  2018年   15篇
  2017年   14篇
  2016年   30篇
  2015年   21篇
  2014年   24篇
  2013年   29篇
  2012年   43篇
  2011年   56篇
  2010年   29篇
  2009年   18篇
  2008年   50篇
  2007年   44篇
  2006年   52篇
  2005年   64篇
  2004年   58篇
  2003年   56篇
  2002年   55篇
  2001年   28篇
  2000年   27篇
  1999年   33篇
  1998年   19篇
  1997年   13篇
  1996年   10篇
  1995年   12篇
  1994年   4篇
  1993年   8篇
  1992年   26篇
  1991年   10篇
  1990年   11篇
  1989年   9篇
  1988年   6篇
  1987年   9篇
  1986年   9篇
  1985年   5篇
  1984年   2篇
  1983年   4篇
  1982年   3篇
  1979年   2篇
  1977年   2篇
  1974年   1篇
  1972年   1篇
  1970年   1篇
  1969年   1篇
  1960年   1篇
  1919年   1篇
排序方式: 共有1000条查询结果,搜索用时 15 毫秒
1.
Modification of a hand splint for a musician who had suffered an incomplete disruption of the left ring finger extensor tendon is described. This modification enabled the patient to receive the benefit of conservative treatment of this disruption while continuing his employment. The modification can be performed easily with the standard stack splint; the success of this method is described.  相似文献   
2.
12 giant intracranial aneurysms were studied by MRI. Intraluminal thrombosis was observed in 9 aneurysms. Thrombosis was found more frequently in larger aneurysms. Thrombi were formed posteriorly or inferiorly in the lumen of 4 among 5 IC-cavernous aneurysms. Location of the neck of the aneurysms and stagnation of blood flow influenced by gravity may be causative factors determining the location of thrombi. In 6 aneurysms intraluminal thrombi were inhomogeneous on MRI, suggesting that the thrombi had been formed at different times. New thrombi were formed between the aneurysmal wall and the old thrombus in 3 cases. Dissection of the aneurysmal wall by residual blood flow in the lumen or hemorrhage in the aneurysmal wall may be one of the growth mechanisms of giant intracranial aneurysms.  相似文献   
3.
We report a case of granulocyte-colony stimulating factor producing gastric cancer with multiple liver metastases. A 68-year-old woman who complained of epigastralgia visited our hospital. Upper gastrointestinal endoscopic examination revealed a type-2 gastric cancer. The laboratory data at admission indicated leukocytosis (35,900/microl) and a high level of serum granulocyte-colony stimulating factor (61 pg/mg). Granulocyte-colony stimulating factor producing gastric cancer was diagnosed by immunohistochemistry of biopsy specimen. Since we detected multiple liver metastases, chemotherapy was performed. Granulocyte-colony stimulating factor-producing gastric cancer is relatively rare and we summarize previous reports.  相似文献   
4.
5.
To investigate the fine vascular structures in the spinal and paraspinal region, the authors performed three-dimensional GRASS scanning after the administration of contrast material. The scan sequence was sagittal volume scan, TR/TE 100/16, with a flip angle of 45 degrees. First-order gradient moment nulling was employed. Four normal volunteers and 31 patients were studied. Using this technique, longitudinal anterior epidural veins and vertebral arteries were clearly identified. Paraspinal fine vessels of slow to moderate flow, including dilated anterior spinal artery, radiculo-medullary vein, and perimedullary coronal venous plexus, were demonstrated in pathological cases. In addition, with processing of the volume data set, phlebographic projection images of the ladder-shaped anterior epidural venous system could be generated. This method provided more detailed information on epidural and intradural vessels than conventional MR imaging.  相似文献   
6.
Purpose: To evaluate the efficacy of transcatheter oily chemoembolization (TOCE) for hepatoceliular carcinoma (HCC) on the basis of microscopic and macroscopic findings postembolization. Methods: HCCs ranging in size from 0.5 to 13 cm (mean 3.6 cm) were obtained from partial hepatectomies of 100 consecutive patients who had undergone TOCE between 20 and 246 days (mean 59.5 days) prior to surgery. The efficacy of TOCE was assessed on the basis of the necrotic to live cell ratio of the tumors. The microscopic pattern of tumor growth was grouped into expanding type (complete capsule formation) and replacing type (incomplete or no capsule). There were five types of macroscopic groupings: single nodule, single nodule with extranodular growth (SNE), contiguous and noncontiguous multinodular, and massive growth type. Results: Among 79 cases with the expanding type, 29 (37%) had 100% HCC necrosis, but none with 100% necrosis were in the replacing type. By macroscopic grouping, the efficacy of TOCE decreased from the single nodule type (50% of patients had 100% necrosis) to the SNE type (21%), and the other types (9%).  相似文献   
7.
Primary squamous cell carcinoma of the submandibular gland is a rare tumor. In this report, the histological and ultrastructural features of a case of primary squamous cell carcinoma arising in the left submandibular gland is presented. Light microscopically, the tumor consisted of well differentiated keratinizing squamous cell nests. Ultrastructurally, the tumor cells were oval or spindle-shaped, and several tumor cells had intracytoplasmic desmosome-like structures, resembling intercellular desmosomes. The majority of the tumor cells contained a large number of intermediate filaments (tonofilaments). Intercellular desmosomes were well developed. No secretory granules were found. These ultrastructural features may enable us to distinguish primary squamous cell carcinoma from mucoepidermoid carcinoma which is often misdiagnosed as squamous cell carcinoma.  相似文献   
8.
One hundred and forty four patients with chronic hepatitis B were tested to identify new mutations associated with hepatitis B e antigen (HBeAg) negativity, using a full genome sequence analysis. All the patients were Chinese and had hepatitis B virus infection of genotype C. Patients with none of the pre-core or core promoter mutations were significantly (P < 0.001) less common in the group with anti-HBe (13%) than in the group with HBeAg (56%). The complete nucleotide sequence was determined in four anti-HBe-positive patients who had neither pre-core nor core promoter mutations and in five HBeAg-positive patients who also had neither of these mutations (the groups were matched for age and sex). Six mutations were found to be significantly more common in the former group than in the latter: G529A (3/4 vs. 0/5), C934A (4/4 vs. 1/5), A1053G (4/4 vs. 1/5), G1915T/A (4/4 vs. 0/5), T2005C/A (4/4 vs. 0/5), and C3026T (3/4 vs. 0/5). Three of the six mutations were significantly more common in the four anti-HBe-positive patients who had neither pre-core nor core promoter mutations, compared to 11 HBeAg-positive patients who had pre-core and core promoter mutations, and also compared to 15 anti-HBe-positive patients who had pre-core and core promoter mutations, suggesting further the specificity of these mutations. Of the six mutations, two resulted in amino acid substitution in the polymerase protein, and one is located near the enhancer I region. The results suggest that the six newly discovered mutations are associated with HBeAg negativity.  相似文献   
9.
10.
Hepatic elimination of 4-methylumbelliferone (4MU), which has been used as a model compound for conjugative metabolism, was studied by means of a multiple indicator dilution (MID) method in the isolated perfused rat liver. Using this method, three intrinsic hepatic clearances, CL int,inf , CL int,eff, and CL int,seq, which represent the influx, efflux, and sequestration processes, respectively, were obtained. When the dose was increased from a low dose (50 g/rat liver) to a high dose (3000 g/rat liver), the hepatic availability of 4MU increased from 0.11 to 0.73. With increasing dose, the CL int,eff value increased approximately two times, while the CL int,seq value decreased to approximately one-third. The remarkable dose dependence of hepatic availability was due to nonlinearity in both CL int,eff and CL int,seq values. However, the CLint,inf value was almost independent of dose. The dose-dependent change in CLint,seq might be explained by the saturation of conjugative metabolism of 4-MU, while the increase in the CL int,eff value with increasing dose might be partly explained by the nonlinear tissue binding of 4-MU, since the tissue unbound fraction determined by an ultrafiltration method using liver homogenate increased approximately 1.5 times at higher concentration of 4-MU compared to that at lower concentrations. In addition, based on a comparison of the individual intrinsic clearances, i.e., CL int,inf , CL int,eff, and CL int,seq, the major determining process of the apparent hepatic intrinsic clearance of 4MU is thought to be the sequestration process at the high dose. However, at the low dose, the membrane transport process (influx and efflux processes) as well as the sequestration process also determine the apparent hepatic intrinsic clearance.  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