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   1334篇
  免费   106篇
  国内免费   10篇
耳鼻咽喉   11篇
儿科学   24篇
妇产科学   18篇
基础医学   282篇
口腔科学   36篇
临床医学   160篇
内科学   311篇
皮肤病学   34篇
神经病学   69篇
特种医学   114篇
外科学   113篇
综合类   11篇
预防医学   60篇
眼科学   12篇
药学   98篇
  1篇
中国医学   1篇
肿瘤学   95篇
  2022年   10篇
  2021年   13篇
  2018年   20篇
  2017年   15篇
  2016年   23篇
  2015年   28篇
  2014年   36篇
  2013年   33篇
  2012年   71篇
  2011年   67篇
  2010年   49篇
  2009年   38篇
  2008年   38篇
  2007年   35篇
  2006年   50篇
  2005年   55篇
  2004年   42篇
  2003年   43篇
  2002年   37篇
  2001年   43篇
  2000年   39篇
  1999年   37篇
  1998年   28篇
  1997年   27篇
  1996年   34篇
  1995年   20篇
  1994年   30篇
  1993年   20篇
  1992年   22篇
  1991年   33篇
  1990年   27篇
  1989年   28篇
  1988年   29篇
  1987年   21篇
  1986年   29篇
  1985年   24篇
  1984年   28篇
  1983年   23篇
  1982年   14篇
  1980年   10篇
  1979年   19篇
  1978年   9篇
  1977年   13篇
  1976年   12篇
  1975年   11篇
  1971年   14篇
  1970年   9篇
  1968年   7篇
  1967年   12篇
  1966年   14篇
排序方式: 共有1450条查询结果,搜索用时 15 毫秒
1.
The authors have presented the results of a 14-day open randomized trial of the efficacy of 3 calcium inlet blocking agents: nifedipine, verapamil and phendilin in 61 patients with Raynaud's syndrome. In the group of patients receiving 30-80 mg of nifedipine (20) there was a significant decrease in the frequency and expression of Raynaud's syndrome attacks, a positive effect of varying degree was noted in 19 patients. The drug raised slightly the skin and muscular blood flow and skin temperature. The use of 120-360 mg of verapamil in 21 patients caused no significant inhibition of Raynaud's syndrome and rise of hemocirculation. Phendilin (150-300 mg) though being comparable with nifedipine in efficacy, often produced side-effects resulting in the drug cancellation (8 out of 20). The efficacy of the calcium inlet blocking agents, especially nifedipine, for therapy of Raynaud's syndrome was emphasized.  相似文献   
2.
3.
Sucralfate is known for its gastroprotective properties in humans and rats, but the importance of intragastric pH in this protection is a subject of controversy. This study, performed on healthy young volunteers and rats, was designed to compare the gastroprotective effects of sucralfate with those of sucralfate combined with ranitidine or of sucralfate adjusted to pHs varying from 1 to 7. In humans the mucosal damage induced by 40% ethanol spray after 4 days of pretreatment with placebo, sucralfate (1 g four times daily), ranitidine (150 mg three times daily), or the combination of sucralfate plus ranitidine was evaluated by means of endoscopy with mucosal biopsy and histologic examination. Sucralfate alone reduced the endoscopic score significantly (compared with placebo) and prevented deep necrotic lesions. Neither ranitidine alone nor its combination with sucralfate prevented ethanol-induced endoscopic and histologic mucosal changes. In rats acute gastric lesions were induced by 100% ethanol. Sucralfate was relatively more effective in mucosal protection against ethanol when given at lower pH (1 or 2) than at original pH (4.5) and failed to protect at neutral pH (7.0). Pretreatment with ranitidine, which by itself did not change ethanol damage, greatly reduced the protection afforded by sucralfate. We conclude that sucralfate protects the gastric mucosa against ethanol damage both in humans and in rats and that this protection is dependent on the presence of an acidic intragastric pH.  相似文献   
4.
5.
The paper is devoted to comparative assessment of combined therapy of prednisolone, chlorambucil, chloroquine phosphate and ibuprofen at small doses and its effect on clinicolaboratory signs of Sjogren's disease in 80 patients in the course of 1 and 5 years. Patients of the control group received only local therapy of the parotid glands. The results have demonstrated that combined therapy at small doses of prednisolone and chlorambucil (5 mg + 4 mg) is an effective method of treatment of the stomatological, ophthalmological and articular manifestations of SD and is also capable of preventing the systemic signs of disease. Combined therapy with chloroquine phosphate and ibuprofen neither influenced the clinicolaboratory signs of disease nor prevented disease progression with the development of systemic signs of diseases of various degrees. Disease progression was observed in 80% of patients receiving no basic drugs or receiving chloroquine phosphate+ibuprofen while in groups of patients receiving small doses of prednisolone and chloambucil disease progression was observed in 20% only.  相似文献   
6.
The management is described of 12 pregnant patients with idiopathic thrombocytopenia. In no case perinatal haemorrhage developed. All labor took place through the genital canal. No perinatal injuries were observed in the newborns.  相似文献   
7.
A solid-phase enzyme immunoassay using both mouse monoclonal and goat polyclonal antibodies against carcinoembryonic antigen (CEA) was developed. The assay detects 0.6 to 1.2 ng of CEA per ml of serum and has 3 incubation steps which can be performed in 1 day. Polystyrene balls coated with polyclonal goat anti-CEA antibodies are first incubated with heat-extracted serum samples. Bound CEA is then detected by addition of mouse monoclonal antibodies, followed by goat IgG anti-mouse IgG1 coupled to alkaline phosphatase. Results with this enzyme immunoassay using monoclonal antibodiies (M-EIA) have been compared with those obtained by the conventional inhibition radioimmunoassay (RIA) using goat antiserum. Three hundred and eighty serum samples from 167 patients with malignant or non-malignant diseases and from 134 normal individuals with or without heavy smoking habits were analyzed by the 2 assays. Excellent correlation between the results of the 2 assays was obtained, but the M-EIA, using monoclonal antibodies from a single hybridoma, did not discriminate better than the conventional RIA between CEA produced by different types of carcinoma and between CEA associated with malignant or non-malignant diseases. Follow-up studies of several patients by sequential CEA determinations with the 2 assays showed that the M-EIA was as accurate as the RIA for the detection of tumor recurrences.  相似文献   
8.
To gain insight into the HLA subregions involved in protection against insulin-dependent diabetes mellitus (IDDM) we investigated the polymorphism of HLA-DR and -DQ genes in 23 DR2 IDDM patients. Results show the following. (1) Fourteen patients (61%) possess the DRB1, DRB5, and DQB1 alleles found in DRw16/DQw5 healthy people. These data contrast with the 5% of DRw16 normally found in DR2 populations and are in agreement with former observations supporting that the DRw16 haplotype is not protective. (2) Nine DR2 patients, i.e., 39% versus 95% in published DR2 controls, possess the DRB alleles found in DRw15 unaffected people. Among them, six patients have also DQA1 and DQB1 alleles identical to those found in DRw15/DQw6 healthy individuals. These data confirm that the DRw15/DQw6 haplotype is protective but indicate that none of the DR or DQ alleles, alone or in association, confers an absolute protection. (3) Our most striking results concern the very high frequency of recombinant haplotypes among the DRw15 patients: 3 of 9. In these three patients recombinations led to the elimination of both DQB1 and DQA1 alleles usually associated with DRw15. This strongly suggests that the occurrence of IDDM in these DRw15 patients is due to the absence of the usual DQ product and thus reinforces the assumption that DQ rather than DR region is involved in the protection conferred by the DRw15/DQw6 haplotype. Finally, analysis of the non-DRw15 haplotypes in heterozygous patients showed that IDDM can occur in the absence of any DQ alpha beta heterodimer of susceptibility.  相似文献   
9.
Vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs) are important regulators of blood and lymphatic vessel growth and vascular permeability. Both blood and lymphatic vessels of the upper respiratory tract play important roles in pathological conditions, such as infections and tumors. Here we have studied the expression of VEGF-C and its receptor VEGFR-3 in the upper respiratory system by Northern blot analysis and immunohistochemistry of human tissues, and in situ mRNA hybridization of developing mouse embryos and β-galactosidase staining of mouse embryos having a LacZ marker gene in the VEGFR-3 gene locus. The results demonstrate expression of VEGF-C and VEGFR-3 in the developing and adult nasal respiratory epithelium and in the nasal vascular plexus, respectively. Unlike in most other tissues, in the nasal mucosa VEGFR-3 is expressed in both blood and lymphatic vessels. Expression of VEGF-C was also detected in nasal and nasopharyngeal tumor islands, which were surrounded by VEGFR-3-positive angiogenic blood vessels. These results suggest that VEGF-C and VEGFR-3 have a role in the development of the nasal submucosal vascular plexus and in its normal function and that they are associated with angiogenesis in nasal and nasopharyngeal tumors.  相似文献   
10.
Carcinoembryonic antigen (CEA) was purified from primary tumour or from hepatic metastases obtained from ten cases of carcinoma of the colon. In nine cases the blood group antigens A, B, Lea or Leb were detected in CEA preparations by the binding of 125I-labelled CEA by blood group antibodies. The extent of binding appeared to preclude simple contamination of CEA preparations by blood group glycoprotein. In all cases the blood group antigens detected were consistent with the patients' known blood groups. Blood group I and i activities were not detected.

It is concluded that the determinants of A, B and Lewis antigens and of CEA share the same glycoprotein carrier molecules.

  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