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   307篇
  免费   15篇
耳鼻咽喉   9篇
儿科学   1篇
妇产科学   8篇
基础医学   114篇
口腔科学   6篇
临床医学   17篇
内科学   44篇
皮肤病学   27篇
神经病学   14篇
特种医学   9篇
外科学   22篇
综合类   2篇
预防医学   15篇
眼科学   4篇
药学   19篇
肿瘤学   11篇
  2022年   7篇
  2021年   11篇
  2020年   5篇
  2019年   11篇
  2018年   6篇
  2017年   4篇
  2016年   10篇
  2015年   5篇
  2014年   8篇
  2013年   13篇
  2012年   13篇
  2011年   39篇
  2010年   12篇
  2009年   5篇
  2008年   22篇
  2007年   24篇
  2006年   16篇
  2005年   27篇
  2004年   9篇
  2003年   11篇
  2002年   7篇
  2001年   3篇
  2000年   4篇
  1997年   1篇
  1996年   1篇
  1994年   2篇
  1992年   3篇
  1991年   3篇
  1990年   2篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   3篇
  1984年   3篇
  1983年   1篇
  1981年   1篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
  1975年   2篇
  1974年   2篇
  1972年   1篇
  1970年   3篇
  1969年   4篇
  1968年   1篇
  1967年   2篇
  1966年   3篇
  1965年   1篇
  1946年   1篇
排序方式: 共有322条查询结果,搜索用时 15 毫秒
1.
A study was made concerning the role of adrenergic and cholinergic neural regulation in the functional activity of enzymes of microsomal oxidation in the liver. Experiments were performed on adult and old rats using surgical denervation of liver (vagotomy and sympathotomy). The results obtained showed changes that occurred in the monooxygenase activity (aminopyrine demethylase and aniline hydroxylase), as well as in the isoform composition and inductive synthesis of cytochrome P-450. The neural control over liver detoxication function was found to weaken in old age.  相似文献   
2.
BACKGROUND: The high-affinity receptor for IgE (FcepsilonRI) on myeloid dendritic cells has been shown to play a major role in atopic dermatitis (AD). Plasmacytoid dendritic cells (pDCs), which are instrumental in the defense of viral infections, are present in reduced amounts in the skin of patients with AD, which is characterized by a high susceptibility to viral infections. OBJECTIVE: We explored phenotypical and functional characteristics of pDC in the peripheral blood of patients with AD and healthy individuals. METHODS: Blood dendritic cell antigen-2+CD123+ pDCs were enriched from the peripheral blood of patients with AD and studied in functional assays. RESULTS: Skin-homing molecules such as cutaneous lymphocyte antigen and L-selectin CD62L were expressed in lower levels on pDCs of patients with AD. pDCs expressed high amounts of IgE-occupied FcepsilonRI. Further, FcepsilonRI aggregation on pDCs impaired the surface expression of MHC I and II, induced the production of IL-10, and enhanced the apoptosis of pDCs. Importantly, FcepsilonRI preactivated pDC produced less IFN-alpha and IFN-beta after stimulation with CpG motifs and enhanced the outcome of immune responses of the TH2 type. CONCLUSION: From these data, we conclude that FcepsilonRI-bearing pDCs from patients with AD (1) are different from pDCs of healthy individuals, (2) might be important in the pathophysiology of AD, and (3) contribute to the enhanced susceptibility of patients with AD to viral infections.  相似文献   
3.
Psammoma bodies are one of many choroid plexus aging changes which origin is still enigma for the scientists. During our investigation psammoma bodies were studied on 30 postmortem brains by light microscopy. They stained red with HE, and were PAS and AB PAS positive. The largest number of lamellas were stained blue with Mallory's connective tissue stain, except peripheral and next to the center lamella which stained red. During the aging, psammoma bodies became larger and more irregular, which was followed with group area and perimeter, single psammoma body average area and average perimeter, average diameter and contour index increase. Psammoma bodies mearged in the second and the third age group and mearging process led to larger and more irregular structures formation. The results of this investigation suggest that psammoma bodies are more frequent in choroid plexus of healthy older people and during the aging they obtain larger dimensions, more irregular contours, which is the result of their mutual mearging.  相似文献   
4.
5.
Transfer of human ApoA1 gene within the molecular construction which provides its expression, to the liver of the adult and aged rats resulted in the appearance of human protein in their blood, and was accompanied by changes in the content of high-density lipoproteins and of their subclasses HDL(3) and HDL(2), as well as by the shifts in their protein and lipid composition. Synthesis of human ApoA1 was more marked in the organism of adult rats, and gene-regulatory shifts in aged rats.  相似文献   
6.
Aim. To analyze hemodialysis (HD) treatment of patients with Balkan endemic nephropathy (BEN) from five endemic villages in the South Morava Region of Serbia. Analyses of patterns of incidence may generate hypotheses about the underlying causes of BEN, and prevalence data provide information on the current and likely future burden on health services for managing BEN. Methods. A total of 143 end-stage kidney disease patients (ESKD) with BEN were admitted to the renal replacement program from 1974 to 2004: 121 to HD, 15 peritoneal dialysis, and 7 kidney transplantation. As a control group, 117 patients with other kidney disease (chronic pyelonephritis, glomerulonephritis, and ischemic nephropathy) admitted to HD at the time of BEN patients and matched by age and gender were studied. Results. Most of the BEN patients (93.4%) treated by HD were born from 1917 to 1941. The majority of patients (79.3%) started HD from 1977 to 1991 (period of 15 years). The mean age of BEN patients starting HD treatment was 49.1 years in the period from 1974 to 1978, and increased steadily in the following years, being 72.5 years in the last period of study (2004–2006) The mean survival time of BEN males was 4.70 (95% CI 3.66–5.75) and for females was 5.02 (95% CI 1.47–4.53). Difference between males and females was not statistically significant (log rank 0.14, p?=?0.7, P > 0.5). Mean survival times of 4.84 (95% CI 3.97–5.70) in BEN patients and 3.1 (95% CI 2.78–3.84) in other kidney disease patients were found. Difference between BEN patients and controls was statistically significant (log rank 8.38, p?=?0.0038, P < 0.01). Conclusion. The population of endemic villages around the South Morava River admitted to HD treatment after 1974 was exposed to environmental toxicant(s) from 1917 to 1941. The most intense effect of environmental exposure was in that period, with ESKD in patients in their forties. The exposure to environmental toxicants has diminished, so ESKD of BEN has become less frequent and manifested in the older age, mean 72.5 in the period from 2004 to 2006. Different type of exposure was registered in some other endemic regions in Serbia and abroad.  相似文献   
7.
8.
Progression of kidney damage was studied in 18 patients with Balkan endemic nephropathy (BEN), with a mean 15-year follow-up after renal biopsy. According to kidney function, estimated by 99mTc-DTPA clearance, patients were divided into three groups: with apparently normal kidney function (clearance 103.5 ± 21.3 mL/min/1.73 m2), with incipient renal failure (clearance 65.5 ± 11.3), and with advanced renal failure (clearance 28.0 ± 6.2). The mean yearly decrease of glomerular filtration rate was 2.74 mL/min. In two patients, an increase of kidney function was recorded. Six patients become dialysis dependent, two from the group with incipient renal failure, but all four from the group with advanced renal failure. Three patients died after 8 to 12 years of follow-up, one from causes unrelated to kidney disease and two from end-stage renal failure. This study has shown that BEN is characterized by a slow course and prolonged evolution, modified by medical supervision and treatment.  相似文献   
9.
10.

Objective

Human BPIFA2 (parotid secretory protein) is a ubiquitous soluble salivary protein, which belongs to the PLUNC family of proteins. Having sequence similarity to bactericidal/permeability-increasing protein and lipopolysaccharide-binding protein, PLUNC proteins are probably involved in local antibacterial response at mucosal sites, such as oral cavity. The aim of the study was to isolate and characterize human BPIFA2.

Design

In this paper, we report one-step affinity chromatography method for BPIFA2 purification from whole human saliva. The isolated BPIFA2 was identified by trypsin mass fingerprinting and characterized by electrophoretic methods. Antibacterial activity of BPIFA2 against model microorganism Pseudomonas aeruginosa was shown in minimum inhibitory concentration and time kill study assays.

Results

The protein showed microheterogeneity, both in molecular weight and pI value. BPIFA2 inhibited the growth of P. aeruginosa in microgram concentration range determined by minimum inhibitory concentration assay. In the time kill study, 32 μg/mL BPIFA2 showed clear bactericidal activity and did not cause any aggregation of bacteria.

Conclusion

Affinity chromatography is well suited for isolation of functional BPIFA2 with a potent bactericidal activity against P. aeruginosa.  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