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   388篇
  免费   20篇
  国内免费   10篇
耳鼻咽喉   2篇
儿科学   23篇
妇产科学   8篇
基础医学   64篇
口腔科学   47篇
临床医学   17篇
内科学   70篇
皮肤病学   9篇
神经病学   4篇
外科学   14篇
综合类   13篇
预防医学   52篇
眼科学   14篇
药学   63篇
中国医学   3篇
肿瘤学   15篇
  2024年   1篇
  2023年   6篇
  2022年   20篇
  2021年   20篇
  2020年   5篇
  2019年   12篇
  2018年   10篇
  2017年   12篇
  2016年   9篇
  2015年   12篇
  2014年   18篇
  2013年   33篇
  2012年   9篇
  2011年   12篇
  2010年   16篇
  2009年   15篇
  2008年   23篇
  2007年   14篇
  2006年   3篇
  2005年   11篇
  2004年   9篇
  2003年   7篇
  2002年   11篇
  2001年   9篇
  2000年   9篇
  1999年   4篇
  1998年   5篇
  1997年   10篇
  1996年   7篇
  1995年   5篇
  1994年   8篇
  1993年   10篇
  1992年   4篇
  1991年   7篇
  1990年   3篇
  1989年   4篇
  1988年   4篇
  1987年   11篇
  1986年   6篇
  1985年   2篇
  1984年   2篇
  1983年   2篇
  1982年   5篇
  1981年   3篇
  1980年   3篇
  1979年   3篇
  1978年   1篇
  1977年   3篇
排序方式: 共有418条查询结果,搜索用时 15 毫秒
41.
Abstract: Human lactoferrin is a natural defense protein belonging to the innate immune system present in several body fluids and secretions, as well as in the secondary granules of polymorphonuclear neutrophils. Lactoferrin and its derivatives have pleiotropic functions including broad-spectrum anti-microbial activity, anti-tumor activity, regulation of cell growth and differentiation, and modulation of inflammatory as well as humoral and cellular immune responses. This is the reason why much research has addressed the potential therapeutic activity of these molecules in different clinical settings, especially regarding infectious diseases and uncontrolled inflammatory conditions. In patients with hematological malignancies treated with a hematopoietic stem cell transplantation (HSCT), morbidity and mortality due to infections and uncontrolled inflammation remains high, despite many advances in supportive care. These life-threatening complications are a result of the damage caused by the conditioning regimens to the mucosal barrier, and the innate and adaptive, humoral, and cellular immune defenses. These complications necessitate the continued exploration of new treatment modalities. Systemic and probably local levels of lactoferrin are decreased following HSCT. Therefore, the use of lactoferrin, or short peptide derivatives that retain the cationic N-terminal moiety that is essential for the anti-microbial and anti-inflammatory activity, may prove to be a promising versatile class of agents for managing the complications that arise from HSCT.  相似文献   
42.
Using high performance liquid chromatography (HPLC) the tear protein profiles were measured in controls, patients with Sjögren's disease, questionable dry eye (idiopathic dry eye), idiopathic chronic conjunctivitis and the corneal melting syndrome.Qualitative comparison of the protein profiles of patients with Sjögren's disease, corneal melting and IgA deficiency shows a marked difference in the heights of various peaks as compared to the profiles of the control group. The total protein content of tears in controls and in patients with idiopathic chronic conjunctivitis is age dependent and appears to increase until the age of 40 and to decrease afterwards. The peaks containing IgA, lactoferrin and lysozyme were measured in various eye diseases. In idiopathic chronic conjunctivitis and in the corneal melting syndrome no differences were seen in comparison with controls. In patients with idiopathic dry eye and Sjögren's disease a marked decrease in the three proteins was seen. The study presented here indicates that the HPLC analysis of tears is a promising technique which may increase our knowledge of this ocular fluid.  相似文献   
43.
Purpose  We developed a lactoferrin conjugate by modifying bovine lactoferrin (bLF) with a 40-kDa branched poly(ethylene glycol) (PEG) molecule (designated 40 k-PEG-bLf), and we evaluated its in vitro activities and pharmacokinetic properties. Materials and Methods  We prepared 40k-PEG-bLf by amino conjugation with N-hydroxysuccinimide-activated PEG. This conjugate was purified by cation exchange chromatography and its in vitro biological activities, such as iron binding, anti-inflammatory effects, and resistance to proteolytic enzymes were investigated. In vivo pharmacokinetics analyses, were also performed to examine the rate of clearance from the plasma in rats. Results  The 40k-PEG-bLf conjugate was fully active in iron binding and exhibited 97.1 ± 5.5% (mean ± S.E., n = 6) of the original anti-inflammatory activity. The in vitro peptic susceptibility of 40 k-PEG-bLf revealed that the proteolytic half-life increased at least 6-fold that of unmodified LF. This PEGylated conjugate demonstrated a plasma half-life that was 8.7-fold longer than that of the unmodified bLF in rats. Conclusions  The 40k-PEG-bLf exhibited improved in vitro bioactivity and stability and enhanced pharmacokinetic properties as compared to those of the unmodified bLF and the 20 k-PEG-bLf conjugate, which was recently developed by PEGylation of bLF with a 20-kDa branched PEG [Nojima Y. et al. Bioconjugate Chem. 19:2253–2259 (2008)].  相似文献   
44.
45.
Abstract: Sjögren’s syndrome is an autoimmune condition affecting the lacrimal and salivary glands and can be associated with rheumatoid arthritis and primary biliary cirrhosis. Parotid salivas collected from patients and normal controls were analysed for lactoferrin, IgA and beta2‐microglobulin (measured by ELISA), and cystatin (measured by a enzyme inhibition assay). Output data provided less variable means, whilst expressing results as a proportion of the total protein provided greater specificity as markers for Sjögren’s syndrome. Levels of specificity for IgA, lactoferrin and beta2‐microglobulin were all high (100, 95 and 100%, respectively). Sensitivity levels of these markers (but not cystatin) tended to be similar for Sjögren’s syndrome secondary to primary biliary cirrhosis (IgA, 25%; lactoferrin, 63%; and beta2‐microglobulin, 50%), compared to Sjögren’s syndrome secondary to connective tissue diseases such as rheumatoid arthritis (IgA, 50%; lactoferrin, 86%; and beta2‐microglobulin; 38%).  相似文献   
46.
Given the role of the intestinal microbiota in obesity and related disease, strategies to modulate the composition of the intestinal microbiota may augment traditional weight-management approaches. Here, we examined the safety and tolerability of 28 days of supplementation with bovine whey-derived lactoferrin and immunoglobulin supplements in a cross-sectional cohort of free-living adults. Participants (n?=?20 each group) received enteric-coated whey-derived bovine lactoferrin (200?mg), immunoglobulin (200?mg or 800?mg), combination lactoferrin/immunoglobuiln supplements (200?mg/200?mg, 200?mg/800?mg) or placebo in a double-blind design. Supplement use was generally well tolerated and routine haematology, and clinical chemistry measures were largely unchanged following supplementation. Measures of body composition remained stable and indices of glycaemic control and blood lipids revealed fluctuations of?<5% but were not significantly different between groups. Overall, short-term lactoferrin/immunoglobulin supplementation was well tolerated in this cohort; use of these types of supplements to enhance other weight management strategies should be investigated over extended periods.  相似文献   
47.
Bovine lactoferrin (bLF) has antibacterial activity against Helicobacter pylori in vitro and is effective to suppress bacterial colonization in mice. The aim of our study was to evaluate the efficacy of orally administered bLF on H. pylori colonization in humans by a randomized, double-blind, placebo-controlled study. Fifty-nine healthy subjects positive for H. pylori infection were recruited. Subjects were randomized into two groups. The bLF group received bLF tablets at a dosage of 200 mg b.i.d. for a period of 12 weeks, and the control group received placebo tablets without bLF. The 13C-urea breath test (UBT) was performed before, during, and at the end of administration, and again 4 weeks after administration. Positive response was defined as more than 50% decrease of the UBT value at the end of administration. Positive response was observed in 10 of 31 bLF-treated subjects (32.3%) and 1 of 28 control subjects (3.6%), indicating that the rate of positive response in the bLF group was significantly higher than that in the control group (bLF vs. control, P < 0.01). These results suggested that bLF administration is effective to suppress H. pylori colonization.  相似文献   
48.

Purpose

Pouchitis is a common complication after ileal pouch-anal anastomosis. Diagnosis is based on the Pouch Disease Activity Index, which comprises clinical symptoms, endoscopic appearance, and histologic confirmation. A Pouch Disease Activity Index ≥ 7 confirms pouchitis. Fecal lactoferrin is a marker of intestinal inflammation, which can aid in the diagnosis of pouchitis. The IBD EZ VUE? test is a simple, rapid, noninvasive test for fecal lactoferrin. Our goal was to study the sensitivity and specificity of this test in the diagnosis of pouchitis.

Methods

Consecutive patients with pouch dysfunction were recruited from October 2005 to July 2006. A fecal sample was collected before calculation of the Pouch Disease Activity Index. An IBD EZ VUE? test was performed on each fecal sample and the results correlated with the diagnosis of pouchitis to calculate sensitivity and specificity of the IBD EZ VUE? test.

Results

There were 32 patients (21 healthy and 11 inflammed pouches). The IBD EZ VUE? test was positive in 14 patients. It had a sensitivity of 100 percent and a specificity of 86 percent in diagnosing pouchitis. The positive predictive value was 76 percent. There were three false-positive results.

Conclusions

The IBD EZ VUE? test is a sensitive method that may remove the need for invasive pouch investigations and lead to greater confidence when antibiotic therapy is commenced. Further investigations may be reserved for those patients who have a positive lactoferrin test and fail to respond to antibiotic treatment.  相似文献   
49.
The diagnosis, prognosis, and assessment of disease activity of inflammatory bowel disease (IBD) require investigating clinical, radiological, and histological criteria, as well as serum inflammatory markers. However, a range of fecal inflammatory markers now appears to have the potential to greatly assist in these processes. Calprotectin, a prominent neutrophil protein, was identified two decades ago as a potentially revolutionary marker for IBD. Following this discovery, numerous additional markers, including S100A12, lactoferrin, and M2-pyruvate kinase, have also been suggested as novel markers of IBD. In the present study, we provide an up-to-date review of fecal markers of IBD, and further, provide a novel analysis of each of these fecal markers in severe ulcerative colitis and compare their expression pattern in contrast to calprotectin.  相似文献   
50.
Polymorphonuclear (PMN) cell count in the ascitic fluid is essential for the diagnosis and management of spontaneous bacterial peritonitis (SBP). To date, PMN cell count is routinely performed by traditional manual counting. However, this method is time-consuming, costly, and not always timely available. Therefore, considerable efforts have been made in recent years to develop an alternative test for a more rapid diagnosis and monitoring of SBP. The use of urinary reagent strips was proposed to achieve an "instant" bedside diagnosis of SBP. A series of reports evaluated the urine strip test for SBP diagnosis and reported promising results. However, a recent large multicenter study revealed a surprising lack of diagnostic efficacy of the urine screening test for SBP diagnosis. Another method, more recently proposed as an alternative to the manual PMN count, is the measurement of lactoferrin in ascitic fluid, but the data available on the diagnostic value of this test are limited to a single study. However, both urinary reagent strips and ascitic lactoferrin tests are qualitative methods and need, therefore, to be fur- ther confirmed by standard cytology of the ascitic fluid. To date, the only quantitative method proposed as a valid alternative to manual PMN counting is automated blood cell counters, commonly used in all laboratories for blood cell counting. Data available in the literature on the diagnostic performance of this method are limited but very promising, and this tool seems to have the potential to replace the manual counting method.  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