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   941篇
  免费   85篇
  国内免费   2篇
耳鼻咽喉   1篇
儿科学   79篇
妇产科学   16篇
基础医学   107篇
口腔科学   31篇
临床医学   123篇
内科学   211篇
皮肤病学   20篇
神经病学   82篇
特种医学   99篇
外科学   81篇
综合类   16篇
一般理论   2篇
预防医学   62篇
眼科学   1篇
药学   46篇
中国医学   1篇
肿瘤学   50篇
  2022年   5篇
  2019年   9篇
  2018年   10篇
  2017年   21篇
  2016年   11篇
  2015年   27篇
  2014年   22篇
  2013年   35篇
  2012年   31篇
  2011年   37篇
  2010年   53篇
  2009年   28篇
  2008年   32篇
  2007年   23篇
  2006年   33篇
  2005年   30篇
  2004年   24篇
  2003年   17篇
  2002年   21篇
  2001年   29篇
  2000年   29篇
  1999年   25篇
  1998年   27篇
  1997年   34篇
  1996年   32篇
  1995年   37篇
  1994年   30篇
  1993年   40篇
  1992年   17篇
  1991年   16篇
  1990年   24篇
  1989年   22篇
  1988年   22篇
  1987年   15篇
  1986年   18篇
  1985年   20篇
  1984年   9篇
  1983年   5篇
  1982年   9篇
  1981年   18篇
  1980年   9篇
  1979年   5篇
  1978年   8篇
  1977年   8篇
  1976年   15篇
  1975年   10篇
  1974年   6篇
  1973年   3篇
  1971年   2篇
  1968年   4篇
排序方式: 共有1028条查询结果,搜索用时 15 毫秒
11.
12.
Sixteen distally-based peroneus brevis muscle flaps were used to cover soft tissue defects in the lateral side of the ankle. The defect in 13 cases was on the lateral malleolus, in two on the lateral side of the calcaneus, and in one case in the Achilles tendon. The patients were all followed up until full recovery (mean 7.6 months, range 1.5–22 months). One flap failed to cover the defect and was replaced with a microvascular latissimus dorsi flap. In three cases minor revision and new skin grafting of the distal end of the flap was necessary. In 15 of the 16 patients the distally-based peroneus brevis muscle was successful in covering the lateral defect in the ankle. The technique of harvesting a flap is reliable, fast, and the overall success of the flap is good. The flap is particularly suitable for covering small or moderate sized defects on the lateral malleolus.  相似文献   
13.
14.
15.
16.
Chronic pulmonary inflammatory diseases predispose towards lung cancer by unknown mechanisms. Butylated hydroxytoluene (BHT) administration to mice causes lung injury and a subsequent inflammatory response, and when administered chronically to certain inbred strains following carcinogen treatment, increases lung tumor multiplicity. We hypothesize that inflammation promotes lung tumor growth in this model system and have begun to examine this hypothesis by assessing inflammatory parameters in inbred strains that vary in their susceptibility to promotion. Positive correlations were found between susceptibilities to tumor promotion and BHT induction of alveolar macrophage and lymphocyte infiltration into alveolar airspaces, and increased vascular permeability (P < .03, P < .04, and P < .005, respectively). The amounts of pulmonary cyclooxygenase (COX)-1 and COX-2 did not strongly correlate with promotion. Because persistent elevation of macrophage content is the hallmark of a chronic inflammatory response, the alveolar macrophage population was depleted by adding chlorine to the drinking water prior to carcinogenesis. This treatment reduced lung tumor multiplicity following 2-stage carcinogenesis (P < .05). These correlations between inflammatory and tumorigenic responses to BHT, along with decreased tumorigenesis after macrophage depletion, are consistent with a role of inflammation in promotion. Inflammatory mediators may provide targets for early diagnosis and chemoprevention.  相似文献   
17.
The authors previously showed that monocytes treated with calcium ionophore (CI) acquire characteristics of mature dendritic cells (DC) in part through a calcineurin-dependent pathway. In this study, the authors evaluated the ability of granulocyte-macrophage colony stimulating factor (GM-CSF), interleukin-2 (IL-2), and interleukin-12 (IL-12) alone or in combination with CI to induce DC characteristics in peripheral blood monocytes. Monocytes obtained by leukapheresis and countercurrent centrifugal elutriation were cultured with calcium, cytokines, or both, profiled by flow cytometry, and assessed for antigen uptake and sensitization of autologous CD8+ T cells to antigen. Monocytes treated with the combination of GM-CSF, IL-2, and IL-12 resulted in immunophenotypic and antigen uptake profiles typical of immature DC, including loss of surface CD14 expression, de novo low-level expression of B7.1, negligible CD83 expression, marked enhancement of CD40 and ICAM-1, and high major histocompatibility complex class I and II levels. A high level of antigen uptake by macro-pinocytosis was observed. In contrast, CI treatment significantly up-regulates B7.1, B7.2, CD40, CD54, and CD83 and substantially down-regulates CD14 and macro-pinocytosis, a profile consistent with mature DC. Many CI-induced modulations, but none resulting from cytokine treatment alone, were inhibited by the calcineurin phosphatase inhibitor cyclosporin A. Compared with monocytes treated with CI alone, combined treatment of monocytes with GM-CSF, IL-2, IL-12, and CI augmented B7.1 and CD83 expression and enhanced sensitization of autologous CD8+ T cells to melanoma-antigen-derived peptides. These results suggest that several independent pathways of DC activation can cooperatively enhance the function of monocyte-derived DC.  相似文献   
18.

OBJECTIVE

We studied the prevalence of diabetic ketoacidosis (DKA) at diagnosis of type 1 diabetes in children in Finland.

RESEARCH DESIGN AND METHODS

From 2002 to 2005, data on virtually all children <15 years of age diagnosed with type 1 diabetes (n = 1,656) in Finland were collected.

RESULTS

DKA was present in 19.4% of the case subjects, and 4.3% had severe DKA. In children aged 0–4, 5–9, and 10–14 years, DKA was present in 16.5, 14.8, and 26.4%, respectively (P < 0.001). Severe DKA occurred in 3.7, 3.1, and 5.9%, respectively (P = 0.048). DKA was present in 30.1% and severe DKA in 7.8% of children aged <2 years.

CONCLUSION

The overall frequency of DKA in children is low in Finland at diagnosis of type 1 diabetes. However, both children <2 years of age and adolescents aged 10–14 years are at increased risk of DKA.The incidence of diabetic ketoacidosis (DKA) in children with newly diagnosed type 1 diabetes may be decreasing in developed countries (1,2).  相似文献   
19.
Achromatopsia is an autosomal recessive disease of the retina, characterized clinically by an inability to distinguish colors, impaired visual acuity, nystagmus and photophobia. A genome-wide search for linkage was performed using an inbred Jewish kindred from Iran. To facilitate the genome-wide search, we utilized a DNA pooling strategy which takes advantage of the likelihood that the disease in this inbred kindred is inherited by all affected individuals from a common founder. Equal molar amounts of DNA from all affected individuals were pooled and used as the PCR template for short tandem repeat polymorphic markers (STRPs). Pooled DNA from unaffected members of the kindred was used as a control. A reduction in the number of alleles in the affected versus control pool was observed at several loci. Upon genotyping of individual family members, significant linkage was established between the disease phenotype and markers localized on chromosome 2. The highest LOD score observed was 5.4 (theta = 0). When four additional small unrelated families were genotyped, the combined peak LOD score was 8.2. Analysis of recombinant chromosomes revealed that the disease gene lies within a 30 cM interval which spans the centromere. Additional fine-mapping studies identified a region of homozygosity in all affected individuals, narrowing the region to 14 cM. A candidate gene for achromatopsia was excluded from this disease interval by radiation hybrid mapping. Linkage of achromatopsia to chromosome 2 is an essential first step in the identification of the disease-causing gene.   相似文献   
20.
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