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   338篇
  免费   15篇
  国内免费   20篇
耳鼻咽喉   1篇
儿科学   12篇
妇产科学   2篇
基础医学   26篇
口腔科学   11篇
临床医学   29篇
内科学   50篇
皮肤病学   6篇
神经病学   18篇
特种医学   155篇
外科学   6篇
综合类   3篇
预防医学   5篇
眼科学   2篇
药学   41篇
肿瘤学   6篇
  2020年   1篇
  2019年   2篇
  2018年   4篇
  2017年   1篇
  2016年   10篇
  2015年   12篇
  2014年   9篇
  2013年   4篇
  2012年   5篇
  2011年   3篇
  2010年   8篇
  2009年   14篇
  2008年   19篇
  2007年   30篇
  2006年   12篇
  2005年   12篇
  2004年   9篇
  2003年   8篇
  2002年   12篇
  2001年   14篇
  2000年   8篇
  1999年   11篇
  1998年   26篇
  1997年   15篇
  1996年   8篇
  1995年   10篇
  1994年   11篇
  1993年   9篇
  1992年   2篇
  1991年   10篇
  1990年   2篇
  1989年   11篇
  1988年   10篇
  1987年   7篇
  1986年   9篇
  1985年   8篇
  1984年   4篇
  1983年   2篇
  1982年   5篇
  1981年   1篇
  1980年   4篇
  1979年   1篇
  1977年   2篇
  1976年   4篇
  1975年   4篇
排序方式: 共有373条查询结果,搜索用时 15 毫秒
41.
目的:完善眼外肌成肌细胞体外培养、鉴定的方法及观察其生物学特性。方法:实验于2005-02/08在青岛大学医学院附院中心实验室(省级实验室)完成。取出生后3~7d的大鼠,通过大鼠眼外肌细胞的取材、分离、消化、培养等技术,观察细胞的形态、生长曲线、细胞融合率,观察大鼠眼外肌卫星细胞的增殖与分化能力,利用成肌细胞标记物α-横纹肌肌动蛋白、中间丝结蛋白免疫细胞化学染色对所获得的细胞进行鉴定。结果:①成肌细胞的生长情况:在生长培养基作用下,细胞增殖旺盛;在分化培养基条件下,细胞分化良好,可融合成肌管。②成肌细胞融合率:在24h和48h融合率提高明显,72h达高峰,之后不再变化。③细胞免疫化学检测结果:α-横纹肌肌动蛋白和中间丝结蛋白免疫细胞化学染色阳性。结论:体外培养的大鼠眼外肌卫星细胞具有良好的增殖与分化能力,其生物学特征同骨骼肌卫星细胞。  相似文献   
42.

Background and purpose:

Tobacco smoke represents a relevant risk factor for coronary heart disease (CHD). Although peroxisome proliferator-activated receptor (PPAR)γ activation reduces inflammation and atherosclerosis, expression of PPARγ in cells and its modulation by smoking are poorly investigated. We previously reported that monocyte/macrophages from healthy smokers exhibited an enhanced constitutive expression of PPARγ. Here, we evaluated PPARγ expression and basal cytokine release in monocytes and monocyte-derived macrophages (MDMs) from 85 CHD patients, classified by their smoking habit (smokers, non-smokers and ex-smokers), and assessed the role of PPARγ ligands in this context.

Experimental approach:

PPARγ protein was detected by Western blot and semi-quantified by PPARγ/β-actin ratio; cytokine release was measured by elisa and nuclear factor-kappaB (NF-κB) translocation by electrophoretic mobility shift assays.

Key results:

As compared to the other groups, MDMs from smoker CHD patients exhibited a reduced PPARγ/β-actin ratio and an increased spontaneous release of tumour necrosis factor-α (TNF-α) and interleukin-6, but with no major variations in monocytes. In cells from selected CHD patients, rosiglitazone inhibited TNF-α release and NF-κB translocation induced by phorbol-12-myristate 13-acetate. The selective PPARγ antagonist GW9662 reversed these effects, with some variations related to smoking habit.

Conclusions and implications:

In CHD patients, exposure to tobacco smoke profoundly affected PPARγ expression, and this was related to levels of secretion of pro-inflammatory cytokines. MDMs from CHD smokers showed the lowest PPARγ expression and released more inflammatory cytokines. Moreover, rosiglitazone''s ability to inhibit cytokine release and its reversal by GW9662 clearly indicated PPARγ involvement in these changes in CHD patients.  相似文献   
43.
44.
Ohne Zusammenfassung  相似文献   
45.
BACKGROUND: The aetiology of pityriasis alba (PA), a common dermatosis in childhood, is still controversial. The objective of this study was to assess the possible aetiopathogenic factors of this disease in infants. METHODS: Forty-four patients with PA and 31 healthy children were examined and compared. Personal hygiene habits, sun exposure, presence of Staphylococcus aureus in nasal fossae and presence of major or minor signs of atopy were assessed during anamnesis and physical examination. Susceptibility to ultraviolet (UV) B radiation was measured by the onset of a contact hypersensitivity reaction to diphenylcyclopropenone in individuals sensitized in previously irradiated areas. RESULTS: The prevalence of PA was higher in individuals with darker skin, in high phototype categories, as well as in males. The number of daily baths and sun exposure between 10.00 h and 15.00 h were significantly higher in the PA group when compared with controls (P = 0.03 and P = 0.0015, respectively). The presence of atopy signs was more common in pityriasis patients (P = 0.002). Susceptibility to UVB radiation was 29.6% in the PA group vs. 29.0% in the control group; nevertheless, important differences were found after stratification in order to control possible confounding factors. The presence of S. aureus in the nostrils was equal in both groups. CONCLUSIONS: Our results confirm that PA, in our population, is more prevalent in males and in individuals in higher phototype categories. In those with inadequate personal hygiene and sun exposure habits the disease is more accentuated, demonstrating that the xerosis presenting in individuals with atopic diathesis is an important element in the development of the disease. S. aureus is not an important aetiopathogenic factor in PA. Susceptibility to UVB becomes important when related to the patient's phototype.  相似文献   
46.
Impaired gut barrier function has been reported in a wide range of diseases and syndromes and in some functional gastrointestinal disorders. In addition, there is increasing evidence that suggests the gut microbiota tightly regulates gut barrier function and recent studies demonstrate that probiotic bacteria can enhance barrier integrity. Here, we aimed to investigate the effects of Lactobacillus rhamnosus CNCM I-3690 on intestinal barrier function. In vitro results using a Caco-2 monolayer cells stimulated with TNF-α confirmed the anti-inflammatory nature of the strain CNCM I-3690 and pointed out a putative role for the protection of the epithelial function. Next, we tested the protective effects of L. rhamnosus CNCM I-3690 in a mouse model of increased colonic permeability. Most importantly, we compared its performance to that of the well-known beneficial human commensal bacterium Faecalibacterium prauznitzii A2-165. Increased colonic permeability was normalized by both strains to a similar degree. Modulation of apical tight junction proteins expression was then analyzed to decipher the mechanism underlying this effect. We showed that CNCM I-3690 partially restored the function of the intestinal barrier and increased the levels of tight junction proteins Occludin and E-cadherin. The results indicate L. rhamnosus CNCM I-3690 is as effective as the commensal anti-inflammatory bacterium F. prausnitzii to treat functional barrier abnormalities.  相似文献   
47.
Toksoz  D; Dexter  TM; Lord  BI; Wright  EG; Lajtha  LG 《Blood》1980,55(6):931-936
The isolation of a DNA synthesis inhibitor (NBME fraction IV) and stimulator (RBME fraction III) specific for the hemopoietic stem cell (CFU-s) from freshly isolated normal adult and regenerating murine bone marrow, respectively, has been well documented. We have utilized long- term liquid bone marrow cultures in a further analysis of the role of these factors in the regulation of CFU-s proliferation. Our results show that shortly after feeding, at a time when the cultured CFU-s are actively proliferating, high levels of the hemopoietic stem cell proliferation stimulator fraction III can be isolated from the culture medium. In contrast, the presence of essentially noncycling CFU-s found in cultures fed 8-10 days previously correlates with high levels of the hemopoietic stem cell inhibitor fraction IV. These results suggest that a certain balance between these factors determines CFU-s proliferation in the long-term cultures. In support of this, DNA synthesis in actively cycling CFU-s in the long-term cultures is inhibited for at least 3 days by the addition of excess NBME fraction IV (inhibitor). Furthermore, DNA synthesis in noncycling cultured CFU-s is stimulated for at least 5 days by the addition of RBME fraction III (stimulator).  相似文献   
48.
Cohen  HJ; Lefer  LG 《Blood》1975,45(1):131-139
A patient with plasma cell myeloma producing only Bence Jones lambda protein was found to have pale intranuclear inclusions in the majority of the bone marrow plasma cells. These inclusions, previously undescribed in myeloma patients producing only Bence Jones protein, contained Bence Jones lambda protein, were non-electron dense, bound by a single membrane, and contained no cytoplasmic structures. Intracytoplasmic inclusions were not present, and the perinuclear cistern was not dilated. Thus, the inclusions may represent intranuclear protein synthesis with anomalous release in the abnormal cells.  相似文献   
49.
我非常高兴向大家推荐这份发展中国家幽门螺杆菌(H.priori)临床指南。该指南的编译是由数位在该领域具有丰富临床经验的世界知名专家共同完成的。  相似文献   
50.
Duodenal hematoma: the ring sign in MR imaging   总被引:1,自引:1,他引:0  
Hahn  PF; Stark  DD; Vici  LG; Ferrucci  JT  Jr 《Radiology》1986,159(2):379-382
Proper management of duodenal hematoma requires that an accurate diagnosis be made using noninvasive radiological methods. Conventional imaging may be nonspecific if there is no history of trauma or coagulopathy. Two cases of duodenal hematoma that were imaged by magnetic resonance (MR) and computed tomography (CT) are described. In both cases the hematoma had a well-defined concentric ring configuration on MR images, a finding which helped establish the diagnosis. MR imaging may provide tissue-specific characterization of duodenal hematomas.  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