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   863篇
  免费   41篇
  国内免费   4篇
耳鼻咽喉   4篇
儿科学   16篇
妇产科学   9篇
基础医学   127篇
口腔科学   25篇
临床医学   53篇
内科学   258篇
皮肤病学   27篇
神经病学   36篇
特种医学   17篇
外科学   99篇
综合类   6篇
预防医学   89篇
眼科学   4篇
药学   47篇
中国医学   2篇
肿瘤学   89篇
  2023年   10篇
  2022年   8篇
  2021年   20篇
  2020年   15篇
  2019年   17篇
  2018年   22篇
  2017年   10篇
  2016年   17篇
  2015年   22篇
  2014年   24篇
  2013年   36篇
  2012年   65篇
  2011年   76篇
  2010年   40篇
  2009年   30篇
  2008年   52篇
  2007年   73篇
  2006年   47篇
  2005年   54篇
  2004年   50篇
  2003年   27篇
  2002年   38篇
  2001年   19篇
  2000年   8篇
  1999年   8篇
  1998年   8篇
  1997年   14篇
  1996年   9篇
  1995年   4篇
  1994年   7篇
  1992年   8篇
  1991年   6篇
  1990年   4篇
  1989年   3篇
  1988年   9篇
  1987年   3篇
  1985年   4篇
  1984年   2篇
  1983年   2篇
  1982年   2篇
  1979年   2篇
  1978年   4篇
  1977年   2篇
  1974年   6篇
  1973年   3篇
  1972年   2篇
  1971年   2篇
  1967年   2篇
  1966年   2篇
  1965年   3篇
排序方式: 共有908条查询结果,搜索用时 15 毫秒
1.
The objective of this study was to assess the clinical significance of autoimmune anticardiolipin antibody that can react with cardiolipin only in the presence of beta2-glycoprotein I (beta2-glycoprotein I- dependent anticardiolipin antibody) in the pathogenesis of early recurrent abortion. A total of 72 early recurrent spontaneous aborters and 175 normal healthy women were analysed for the occurrence of beta2- glycoprotein I-dependent anticardiolipin antibody in serum samples by an enzyme-linked immunosorbent assay specific for the detection of beta2-glycoprotein I-dependent anticardiolipin antibody. The incidence of beta2-glycoprotein I-dependent anticardiolipin antibody in the early recurrent spontaneous aborters was essentially the same as that of normal women. Thus, the beta2-glycoprotein I-dependent anticardiolipin antibody seemed to have little, if any, implication in the pathogenesis of early recurrent spontaneous abortion.   相似文献   
2.
3.
The carcinogenic potential of chloroform was evaluated in a short-term carcinogenicity testing system using CB6F1 rasH2-Tg (rasH2-Tg) mice. Chloroform was administered to rasH2-Tg males at doses of 28, 90, or 140 mg/kg and rasH2-Tg females at 24, 90, or 240 mg/kg by oral gavage for 26 weeks. Wild-type (non-Tg) male and female mice received doses of 140 mg/kg and 240 mg/kg, respectively. N-methyl-N-nitrosourea was administered to rasH2-Tg mice by single intraperitoneal injection (75 mg/kg) as a positive control. In both the rasH2-Tg and non-Tg mice, there was no significant increase in the incidence of neoplastic lesions by chloroform treatment. The incidence of hepatocellular foci in the rasH2- and non-Tg females receiving 240 mg/kg was increased. Forestomach tumors and malignant tumors occurred in most of the rasH2-mice in the positive control group. Swelling or vacuolation of hepatocytes, a toxic change induced by chloroform, occurred in both the rasH2-Tg and non-Tg mice. It is concluded that chloroform, a putative human noncarcinogen, did not show evidence of carcinogenic potential in the present study using rasH2-Tg mice. This study suggests that the rasH2-Tg mouse model may not be appropriate for detecting nongenotoxic carcinogens. However, the sensitivity of rasH2-Tg mice to nongenotoxic carcinogens should be assessed with consideration of the results from the other ILSI-HESI project studies.  相似文献   
4.
The musk shrew, Suncus murinus, is one of the primitive mammals and has a pair of palatine tonsils. In the present study, we investigated the blood microvascular architecture of the tonsil in this animal by scanning electron microscopy of corrosion casts. The paranodular arterioles entered the lymph nodule to form a coarse capillary plexus within the nodule. Some of the arterioles reached the dome region to give rise to a fine meshwork of dome subepithelial capillaries. This dome subepithelial capillary network did not show any hairpin or switch-back patterns, as seen in human and rabbit tonsils. Both of the nodular and dome capillaries were drained into the postcapillary venules in the periphery of the nodular or the paranodular region. On the surface of these cast venules, oval-shaped indentations were seen corresponding to the luminal surface of the high endothelial venules. These venules were collected into the large vein at the bottom of the tonsil. The blood vascular architecture of the musk shrew tonsil is basically the same as those of other mucosa-associated lymphoid tissues in mammals.  相似文献   
5.
Sato T  Ohno S  Hayashi T  Sato C  Kohu K  Satake M  Habu S 《Immunity》2005,22(3):317-328
To understand how CD8 expression is regulated during the transition process from CD4+8+ (CD4 and CD8 double positive, DP) to CD4-8+ (CD8 single positive, CD8SP) cells in the thymus, the involvement of Runx proteins in the alteration of chromatin configuration was investigated. Using the chromatin immunoprecipitation assay, we first demonstrated that Runx proteins bind to the stage-specific CD8 enhancer, as well as the CD4 silencer, in CD8SP thymocytes. Among Runx family members, Runx3 expression was initiated in DP thymocytes receiving a positive selection signal and increased in concert with differentiation to the CD8SP stage. Furthermore, reactivation of the CD8 gene, as well as CD4 silencing, was suppressed in positively selected thymocytes of Runx dominant-negative transgenic mice. These results suggest that Runx proteins, especially Runx3, are involved in lineage specification of CD8 T cells and provide important information for understanding the mechanism for the mutually exclusive expression of coreceptors in mature thymocytes.  相似文献   
6.
The effects of exercise on nutrient digestion and absorption in the intestinal tract are not well understood. A few studies have reported that exercise training increases the expression of molecules involved in carbohydrate digestion and absorption. Exercise was also shown to increase the blood concentration of glucagon-like peptide-2 (GLP-2), which regulates carbohydrate digestion and absorption in the small intestine. Therefore, we investigated the effects of exercise on the expression of molecules involved in intestinal digestion and absorption, including GLP-2. Six-week-old male mice were divided into a sedentary (SED) and low-intensity exercise (LEx) group. LEx mice were required to run on a treadmill (12.5 m/min, 1 h), whereas SED mice rested. All mice were euthanized 1 h after exercise or rest, and plasma, jejunum, ileum, and colon samples were collected, followed by analysis via IHC, EIA, and immunoblotting. The levels of plasma GLP-2 and the jejunum expression of the GLP-2 receptor, sucrase-isomaltase (SI), and glucose transporter 2 (GLUT2) were higher in LEx mice. Thus, we showed that acute low-intensity exercise affects the expression of molecules involved in intestinal carbohydrate digestion and absorption via GLP-2. Our results suggest that exercise might be beneficial for small intestine function in individuals with intestinal frailty.  相似文献   
7.
8.
9.
We report a case of a long-term survivor with malignant melanoma of the anus who did not undergo radical surgery. A 71-year-old woman who presented with anal bleeding and anal tumor underwent an excisional biopsy in September 1985. The biopsy specimen was a lobulated, polypoid, pigmented mass 2 cm in diameter, that had been located on the anterior wall of the anus. A satellite nodule 7 mm in diameter was found on the left wall of the anus at the level of the dentate line. Both tumors were histologically diagnosed as malignant melanoma. The primary tumor was 6 mm thick. Melanoma cells were present microscopically at the cut end of the rectum. Because of her history of ischemic heart disease, the patient rejected our recommendation that she undergo radical surgery, and received 10 courses of carboplatin 20 mg intramuscularly and OK-432 10 K.E. (Klinische Einheit) intradermally every week. A single, pigmented metastatic inguinal lymph node developed and was excised in June 1987. A recurrent tumor was detected in the rectum in October 1992, so again we recommended radical surgery. The patient rejected radical surgery again, and received 12 courses of carboplatin 10 mg intramuscularly every 2 weeks. She died of disease at home in July 1993 after surviving for 7 years and 10 months. An autopsy was not performed. This case shows that local excision of the primary lesion may be appropriate to preserve the quality of life of patients with early-stage malignant melanoma of the anus.  相似文献   
10.
BackgroundAlthough high-dose glucocorticoids are effective in suppressing active inflammation of Takayasu arteritis (TAK), many patients experience relapse during tapering of glucocorticoids. Recently, the interleukin-6 receptor antibody, tocilizumab (TCZ), was reported to be effective for steroid-resistant TAK. However, there are no objective ways of diagnosing TAK recurrence because TCZ suppresses inflammatory biomarkers.ObjectivesTo investigate the efficacy of TCZ at 1-year follow-up and of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography for detection of recurrence of inflammation during TCZ treatment.Methods and ResultsWe treated 19 patients with refractory TAK with TCZ. TCZ was discontinued in 2 cases because of side effects. Abatement of arteritis symptoms along with reduction of glucocorticoid dosage was achieved in 12 patients, resulting in a remission induction rate of 70.6%. The dosage of glucocorticoid was reduced from 16.1 ± 10.2 mg to 3.8 ± 1.7 mg at 1 year (p<0.001) in these patients. In the remaining 5 patients, glucocorticoid tapering led to exacerbation of symptoms and glucocorticoid dose had to be increased. FDG-PET scan results closely matched clinical course in all 5 patients with recurrence even during TCZ treatment, while the scan was negative for the remaining 12 patients.ConclusionsTCZ injection provides robust steroid-sparing effect and improvement of inflammation without significant adverse effects. Recurrence of inflammation can be detected by FDG-PET even during TCZ treatment.  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