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   3316篇
  免费   227篇
  国内免费   5篇
耳鼻咽喉   66篇
儿科学   142篇
妇产科学   121篇
基础医学   507篇
口腔科学   52篇
临床医学   287篇
内科学   635篇
皮肤病学   56篇
神经病学   460篇
特种医学   104篇
外国民族医学   1篇
外科学   430篇
综合类   23篇
预防医学   179篇
眼科学   76篇
药学   199篇
中国医学   4篇
肿瘤学   206篇
  2023年   15篇
  2022年   39篇
  2021年   79篇
  2020年   45篇
  2019年   81篇
  2018年   92篇
  2017年   55篇
  2016年   56篇
  2015年   65篇
  2014年   109篇
  2013年   158篇
  2012年   198篇
  2011年   186篇
  2010年   95篇
  2009年   95篇
  2008年   192篇
  2007年   188篇
  2006年   211篇
  2005年   214篇
  2004年   159篇
  2003年   156篇
  2002年   129篇
  2001年   109篇
  2000年   115篇
  1999年   88篇
  1998年   25篇
  1997年   20篇
  1996年   34篇
  1995年   24篇
  1994年   14篇
  1993年   15篇
  1992年   55篇
  1991年   38篇
  1990年   41篇
  1989年   35篇
  1988年   40篇
  1987年   36篇
  1986年   40篇
  1985年   30篇
  1984年   23篇
  1983年   14篇
  1982年   10篇
  1981年   13篇
  1980年   10篇
  1979年   21篇
  1978年   10篇
  1975年   8篇
  1974年   9篇
  1971年   8篇
  1967年   6篇
排序方式: 共有3548条查询结果,搜索用时 31 毫秒
1.
2.
3.
Retinitis pigmentosa (RP) is the most common hereditary dystrophic disease of the retina. About 10% of the affected families show the X-linked trait. The close link observed between the gene locus (RP2) and a polymorphic DNA marker (DXS7) on the proximal short arm of the X-chromosome permits an indirect genotype diagnosis and can be helpful in carrier detection and genetic counseling. A case is presented in which the carrier risk of a female consultant dropped from 50% a priori to less than 2% by the use of clinical findings and DNA analysis.  相似文献   
4.
BACKGROUND: Artemisia species pollen represents a major cause of allergy in Central Europe. Variations in the pollen season, the influence of climate variables and the prevalence of pollinosis to it were analyzed in Poznan, in western Poland between 1995 and 2004. METHODS: A Hirst volumetric spore trap was used for atmospheric sampling. Pollination date trend analysis and Spearman correlation tests were performed. Skin prick tests (SPT) and allergen specific immunoglobulin (lg)E antibody measurements were performed in 676 and 524 patients, respectively. RESULTS: The Artemisia species pollen season grew longer due to a clear advance in the starting day and only a slightly earlier end point; the peak day also came slightly earlier. Rainfall in the first fortnight of July highly influenced pollen season severity. Temperature was directly correlated with daily Artemisia species pollen levels; relative humidity was inversely correlated. Twelve percent of patients had a positive SPT reaction to Artemisia species. Their symptoms were rhinitis and conjunctivitis (15%), atopic dermatitis (15%), chronic urticaria (14.3%), bronchial asthma (2.4%), and facial and disseminated dermatitis (1.3%). Elevated specific IgE concentrations were detected in the sera of 10.1% of patients. CONCLUSIONS: Artemisia species pollen is an important cause of pollinosis in western Poland. Pollen season intensity is highly influenced by rainfall in the previous weeks. Trends towards earlier season starts and longer duration, possibly caused by climate change, may have an impact on the allergic population.  相似文献   
5.
Little is known about the effects of immunosuppression on patients with hereditary nonpolyposis colorectal cancer (HNPCC). We describe a kidney transplant recipient with unrecognized Muir-Torre syndrome in whom the administration of a tacrolimus-based regimen led to the eruption of multiple sebaceous tumors. The patient was later found to harbor an MSH2 mutation. Switching to a sirolimus-based regimen resulted in arrest of the disease. When the patient was switched back to tacrolimus, new facial lesions rapidly appeared. Switching again to sirolimus resulted again in halting the appearance of new lesions. This finding is in line with the known antiangiogenic activity of sirolimus and reports on the regression of cutaneous Kaposi's sarcoma in kidney transplant recipients switched from another immunosuppressive regimen to sirolimus. Further studies on the potential use of sirolimus for the treatment of de novo tumors in immunosuppressed kidney transplant recipients with HNPCC are warranted.  相似文献   
6.
The case of a 34-yr-old man with congenitally corrected transposition of the great vessels is described. Both first-pass and equilibrium radionuclide angiographic data were acquired and demonstrate the value of both studies in delineating the ventricular inversion and the transposed great vessels that are characteristic of this disorder. In addition to the anatomic information, the ejection fractions of the venous and systemic ventricles at rest and during exercise, the lack of any left to right shunt, and the presence of systemic A-V valve insufficiency can all be obtained from the scintigraphic data.  相似文献   
7.
Unfractionated wheat gliadin was used to produce murine monoclonal antibodies to gliadin. A dot immunobinding assay, using these antibodies, was developed to detect possible gliadin contamination of nominally gluten-free flour, using dilute ethanol extracts spotted onto nitrocellulose membranes. The sensitivity of the assay was less than 10 micrograms/ml of unfractionated gliadin which permitted the detection of trace amounts of gliadin present in certain wheat starch based 'gluten-free' products. The assay detected not only wheat gliadin, but also prolamine extracts of rye, barley and oats; maize, soya and potato extracts as well as the control proteins casein and ovalbumin, gave negative results. The assay is of value as a simple and rapid method of screening foods for their suitability for consumption by patients with coeliac disease.  相似文献   
8.
Cystic fibrosis (CF) and Crohn's disease may both present as failure to thrive and recurrent intestinal obstruction. Proper treatment and adequate nutrition may reverse these manifestations and improve the patient's quality of life. We describe a girl with CF who, despite appropriate management, failed to grow and had several episodes of bowel obstruction. After the additional diagnosis of Crohn's disease was reached, the patient improved on antiinflammatory and nutritional therapy. This patient illustrates the pitfall in the diagnosis of Crohn's disease in a CF patient due to the clinical overlap between the two conditions. We suggest that therapeutic failure in a chronic disease justifies additional diagnostic efforts resulting in a completion of diagnosis and significant changes in management.  相似文献   
9.
10.
The effects of spermine, spermidine and putrescine on the binding of the GABAA-benzodiazepine receptor complex were examined in the hippocampus and frontal cortex membranes of the rat. The results demonstrated modulatory effects of polyamines on the binding of diazepam and flunitrazepam but not on that of GABA, muscimol and Ro 15-1788. When membranes were prepared without detergent, the polyamines enhanced the binding of diazepam. However, while the binding capacity increased after homogenization in the presence of the non-ionic detergent Triton X-100, the polyamines did not enhance the binding but inhibited the binding of diazepam and flunitrazepam at greater concentrations. Considered together with other studies, the present findings indicate that polyamines can modulate the binding characteristics of several different neurotransmitter receptor-ionophore complexes.  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