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   253篇
  免费   8篇
  国内免费   1篇
  2023年   5篇
  2022年   13篇
  2021年   11篇
  2020年   11篇
  2019年   10篇
  2018年   7篇
  2017年   4篇
  2016年   8篇
  2015年   11篇
  2014年   15篇
  2013年   12篇
  2012年   23篇
  2011年   25篇
  2010年   11篇
  2009年   8篇
  2008年   9篇
  2007年   7篇
  2006年   15篇
  2005年   11篇
  2004年   14篇
  2003年   12篇
  2002年   5篇
  2001年   4篇
  2000年   4篇
  1999年   5篇
  1992年   1篇
  1991年   1篇
排序方式: 共有262条查询结果,搜索用时 15 毫秒
21.
22.
Serum free prostate-specific antigen (fPSA) is the most useful tumor marker for prostatic cancer screening. However, recently, fPSA has also been detected in sera from patients with pancreatic diseases. In addition, it has been shown that zinc (Zn) concentration might change in both serum and tissues in pancreatic disease. In the present study, we measured serum concentrations of fPSA and Zn as possible markers and prognostic factors in an experimental acute-pancreatitis model. Twenty-five female Wistar albino rats were divided into two groups: the control group (n=10) and the experimental group (n=15). Acute pancreatitis was induced by injection of ethyl alcohol into the common biliary duct. The animals were sacrificed 24 h later to detect the concentrations of serum fPSA and Zn. fPSA values were detected to be significantly higher in the experimental group p<0.001). There was also a significant decrease in the serum Zn level of the acute-pancreatitis group (p<0.001). In conclusion, these findings suggested that a combination of these parameters might represent a significant improvement on the diagnostic value of each of them separately and provide a powerful tool for differential diagnosis and prognosis in pancreatic diseases.  相似文献   
23.
It has been well documented that human milk contains several immunomodulator components which are important during infant period when the newborn's immune system is still under development. In this study, we aim at examining levels of cytokines, zinc (Zn), and copper (Cu) in milk from mothers of premature and mature infants, and comparing changes during lactation periods consequently. Milk was collected from total of 40 mothers (group M: mothers of mature infants, n = 20; group PM: mothers of premature infants, n = 20) from four lactation stages: colostrum (0-7 days), transitional (7-14 days), mature milk (21 days), and mature milk (2nd month). Levels of cytokines (interleukin [IL]-lbeta, IL-2, IL-6, IL-8, tumor necrosis factor-alpha [TNF-alpha]) were determined by chemiluminesence method, whereas atomic absorption spectrophotometer was used for the determination of Zn and Cu levels. Cytokine levels were determined to be high in colostrum and transient milk from mothers of full-term infants, whereas their levels were reduced drastically in the 21st day and the 2nd month milk (P < .01, P < .001). Similar trends were observed in milk from mothers of premature infants, but cytokine levels were significantly lower in colostrum compared to colostrum from mothers of mature infants (P < .01). The differences in cytokine levels were continuous in transient milk (P < .05) and mature milk (21 days) (P < .05), whereas there was no statistically significant differences between milk from both groups of mothers in the 2nd month (P > .05). Zn levels in milk from mothers of premature infants were significantly lower compared to the ones from mothers of mature infants (P < .01) and these differences continued through the 2nd month. Although Cu levels were lower in milk from mothers of premature infants, there was no statistically significant difference except colostrum (P > .05). Our results clearly demonstrate that the level of immunomodulating agents such as cytokines and trace elements in milk from mothers of premature infants is less than the level of the same agents in milk from mothers of full-term infants. Although there are commercially available products for infant feeding, human milk is still the best natural nutrient for newborns. Therefore, when premature infants are breastfed, necessary precautions such as supplemantary diets must be considered for possible infections and risks related with immune system deficiency.  相似文献   
24.
Cyclic ADP-ribose (cADPR), synthesized by CD38, regulates intracellular calcium in uterine smooth muscle. CD38 is a transmembrane protein that has both ADP-ribosyl cyclase and cADPR hydrolase enzyme activities involved in cADPR metabolism. CD38 expression and its enzyme activities in uterine smooth muscle are regulated by estrogen. In the present study, we examined CD38 expression, its enzyme activities, and cADPR levels in myometrium obtained from rats at 14-17 days of gestation (preterm) and at parturition (term). CD38 expression, ADP-ribosyl cyclase activity, and cADPR levels were higher in uterine tissues obtained from term rats compared with that of preterm rats, while activity of cADPR hydrolase did not significantly change. In an effort to address whether changes in estrogen: progesterone ratio that occur during pregnancy account for the observed effects on CD38 expression and function, we determined the effect of different doses of progesterone in the presence of estrogen on CD38 expression and its enzyme activities in uterine smooth muscle obtained from ovariectomized rats. In myometrium obtained from ovariectomized rats, estrogen administration caused increased CD38 protein expression and ADP-ribosyl cyclase activity. The estrogen-induced increases in CD38 expression and ADP-ribosyl cyclase activity were inhibited by simultaneous administration of 10 or 20 mg of progesterone. These results indicate that the estrogen:progesterone ratio determines CD38 expression and ADP-ribosyl cyclase activity. These changes in CD38/cADPR pathway may contribute to increased uterine motility and onset of labor.  相似文献   
25.
Collodion baby is a rare keratinizing congenital disorder. Although it is milder in degree than harlequin fetus, the infant is at risk for increased water loss, thermal instability, percutaneous toxicity, and infection as a result of an impaired skin barrier function. Here we report on an 11 days-old collodion baby with hypernatremic dehydratation, septicemia and congenital hypothyroidism. To our knowledge congenital hypothyroidism associated with collodion baby is reported in only one case up to date.  相似文献   
26.
27.
28.
Tripeptidyl-peptidase II (TPP II) is a giant cytosolic peptidase with a proposed role in cellular protein degradation and protection against apoptosis. Beside its well-characterised exopeptidase activity, TPP II also has an endopeptidase activity. Little is known about this activity, and since it could be important for the physiological role of TPP II, we have investigated it in more detail. Two peptides, Nef(69-87) and LL37, were incubated with wild-type murine TPP II and variants thereof as well as TPP II from human and Drosophila melanogaster. Two intrinsically disordered proteins were also included in the study. We conclude that the endopeptidase activity is more promiscuous than previously reported. It is also clear that TPP II can attack longer disordered peptides up to 75 amino acid residues. Using a novel FRET substrate, the catalytic efficiency of the endopeptidase activity could be determined to be 5 orders of magnitude lower than for the exopeptidase activity.  相似文献   
29.
30.

Background and Aims

Understanding the interplay between genetic susceptibility, the microbiome, the environment and the immune system in Crohn’s Disease (CD) is essential for developing optimal therapeutic strategies. We sought to examine the dynamics of the relationship between inflammation, the ileal microbiome, and host genetics in murine models of ileitis.

Methods

We induced ileal inflammation of graded severity in C57BL6 mice by gavage with Toxoplasma gondii, Giardia muris, low dose indomethacin (LDI;0.1 mg/mouse), or high dose indomethacin (HDI;1 mg/mouse). The composition and spatial distribution of the mucosal microbiome was evaluated by 16S rDNA pyrosequencing and fluorescence in situ hybridization. Mucosal E. coli were enumerated by quantitative PCR, and characterized by phylogroup, genotype and pathotype.

Results

Moderate to severe ileitis induced by T. gondii (day 8) and HDI caused a consistent shift from >95% Gram + Firmicutes to >95% Gram - Proteobacteria. This was accompanied by reduced microbial diversity and mucosal invasion by adherent and invasive E. coli, mirroring the dysbiosis of ileal CD. In contrast, dysbiosis and bacterial invasion did not develop in mice with mild ileitis induced by Giardia muris. Superimposition of genetic susceptibility and T. Gondii infection revealed greatest dysbiosis and bacterial invasion in the CD-susceptible genotype, NOD2−/−, and reduced dysbiosis in ileitis-resistant CCR2−/− mice. Abrogating inflammation with the CD therapeutic anti-TNF-α-mAb tempered dysbiosis and bacterial invasion.

Conclusions

Acute ileitis induces dysbiosis and proliferation of mucosally invasive E. coli, irrespective of trigger and genotype. The identification of CCR2 as a target for therapeutic intervention, and discovery that host genotype and therapeutic blockade of inflammation impact the threshold and extent of ileal dysbiosis are of high relevance to developing effective therapies for CD.  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