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   181篇
  免费   3篇
  2023年   3篇
  2022年   1篇
  2021年   8篇
  2020年   4篇
  2019年   8篇
  2018年   20篇
  2017年   9篇
  2016年   14篇
  2015年   5篇
  2014年   6篇
  2013年   7篇
  2012年   10篇
  2011年   16篇
  2010年   13篇
  2009年   5篇
  2008年   13篇
  2007年   10篇
  2006年   4篇
  2005年   4篇
  2004年   7篇
  2003年   6篇
  2002年   8篇
  1999年   1篇
  1997年   1篇
  1993年   1篇
排序方式: 共有184条查询结果,搜索用时 15 毫秒
1.
Objective: The aim of this study was to evaluate serum paraoxonase-1 (PON1) activity and its association with oxidative stress in autoimmune thyroid disease (AITD).

Methods: A total of 50 patients with AITD, including 25 with Hashimoto's thyroiditis and 25 with Graves’ disease were enrolled. The control group comprised 27 healthy subjects. Blood samples were obtained in the euthyroid period and 3 months after initiation of medical treatment. Serum samples from patients with AITD and the healthy control group were analyzed for basal PON1, salt-stimulated PON1, and arylesterase (ARE) activities, along with lipid hydroperoxide (LOOH) and total free sulfhydryl (–SH) levels.

Results: Serum PON1 activities and –SH levels were significantly lower (P?<?0.001, for each), whereas LOOH levels were significantly higher (P?<?0.001, for each) in patients with AITD, compared to the control group. We observed no significant differences in ARE levels between the patient and healthy control groups (P?>?0.05). PON1 activity was positively correlated with –SH (r?=?0.522, P?<?0.001) and negatively correlated with LOOH (r?=??0.487, P?<?0.001). PON1 phenotype distribution of the subjects was not significantly different among the three groups (P?=?0.961).

Conclusions: Serum PON1 activity is decreased in patients with AITD, and correlated positively with –SH, a well-known antioxidant, and negatively with LOOH, an index of lipid oxidation.  相似文献   
2.
This article addresses the ways in which Turkish nationalism has perceived the Kurdish question. It is shown that both Turkish nationalism and the Kurdish question have passed through some paradigmatic moments in the twentieth century. This, I argue, has shaped the way that the Kurdish question has been perceived by Turkish nationalism. While the Kurdish question had been seen by Turkish nationalism mostly in terms of a fatal rivalry between the backward, pre-modern and tribal past and the prosperous present in the first half of the century, it was perceived in terms of a tension between the peripheral economy and national market in the fifties and sixties. In the 1970s, the Kurdish unrest was believed to be a product of communist incitement. Despite this impurity in perception, one thing has remained nearly unchanged for Turkish nationalism: Kurds could become Turkish. In other words, Turkish nationalism of the republican era has principally perceived Kurds as future-Turks. However, the signs in circulation at present indicate that the confidence of Turkish nationalism as to Kurds’ potential of becoming Turkish is not as firm as it used to be. At present, Turkish nationalism seems to be getting prepared to abandon its contention that Kurds are future-Turks.  相似文献   
3.
Effects of oxygen transfer on recombinant protein production by Pichia pastoris under glyceraldehyde-3-phosphate dehydrogenase promoter were investigated. Recombinant glucose isomerase was chosen as the model protein. Two groups of oxygen transfer strategies were applied, one of which was based on constant oxygen transfer rate where aeration rate was Q O/V = 3 and 10 vvm, and agitation rate was N = 900 min?1; while the other one was based on constant dissolved oxygen concentrations, C DO = 5, 10, 15, 20 and 40 % in the fermentation broth, by using predetermined exponential glucose feeding with μ o = 0.15 h?1. The highest cell concentration was obtained as 44 g L?1 at t = 9 h of the glucose fed-batch phase at C DO = 20 % operation while the highest volumetric and specific enzyme activities were obtained as 4440 U L?1 and 126 U g?1 cell, respectively at C DO = 15 % operation. Investigation of specific enzyme activities revealed that keeping C DO at 15 % was more advantageous with an expense of relatively higher by-product formation and lower specific cell growth rate. For this strategy, the highest oxygen transfer coefficient and oxygen uptake rate were K L a = 0.045 s?1 and OUR = 8.91 mmol m?3 s?1, respectively.  相似文献   
4.
The purpose of this study was to elucidate whether exogenous nitric oxide (NO) has a potential beneficial effect on lipase production capacity of some microorganisms. Sodium nitroprusside (SNP) was used as an exogenous NO donor in production medium. In comparison with the control (0 nM SNP), SNP concentrations from 10 to 100 nM induced lipase production in mesophilic bacterium Bacillus subtilis and cold-adapted yeast Yarrowia lipolytica. Especially, the maximum lipase activities for Y. lipolytica (81.2 U/L) and B. subtilis (74.5 U/L) were attained at 30 and 50 nM SNP concentrations, respectively. When compared to the control, the optimal SNP concentrations resulted in about 5.14 and 2.27-fold increases in lipase activities of B. subtilis and Y. lipolytica, respectively. Besides, it was found that the optimal SNP concentrations provided shorter incubation periods for lipase production. Conversely, no significant positive effect of exogenous NO on lipase production was determined for thermophilic bacterium Geobacillus stearothermophilus. This study showed for the first time that exogenous NO could be used as an inducer in the production of microbial lipases.  相似文献   
5.
6.
Epigenetic dysregulation plays a crucial role in cardiovascular diseases. Previously, we reported that acetyltransferase p300 (ATp300) inhibitor L002 prevents hypertension‐induced cardiac hypertrophy and fibrosis in a murine model. In this short communication, we show that treatment of hypertensive mice with ATp300‐specific small molecule inhibitor L002 or C646 reverses hypertension‐induced left ventricular hypertrophy, cardiac fibrosis and diastolic dysfunction, without reducing elevated blood pressures. Biochemically, treatment with L002 and C646 also reverse hypertension‐induced histone acetylation and myofibroblast differentiation in murine ventricles. Our results confirm and extend the role of ATp300, a major epigenetic regulator, in the pathobiology of cardiac hypertrophy and fibrosis. Most importantly, we identify the efficacies of ATp300 inhibitors C646 and L002 in reversing hypertension‐induced cardiac hypertrophy and fibrosis, and discover new anti‐hypertrophic and anti‐fibrotic candidates.  相似文献   
7.

Zika virus has recently evolved from an obscure mosquito-borne pathogen to an international public health concern. People with Zika virus disease can have indications including mild fever, skin rash, conjunctivitis, muscle pain, malaise or headache. Effective vaccines are needed for controlling and preventing the disease. In the current study, we aim to design the substructure for vaccine against Zika virus by forming antigenic peptide epitope of the disease. Zika peptide loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles have been fabricated in the present work as a potential artificial vaccine. UV and FT-IR Spectrophotometers and ZetaSizer were used for studying the nanoparticles, and Scanning Electron Microscope was used for morphological examination. The nanoparticles (NPs) yield, encapsulation efficiency, the peptide loading capacity were determined and in vitro release of the peptide was studied. Cytotoxic effects of the various concentrations of Zika peptide, blank PLGA nanoparticles and Zika peptide loaded PLGA nanoparticles on ECV304 human epithelial cells were determined via MTT assay. The present paper could be considered as one of the important steps in the use of nanoparticles for constructing the new generation of vaccination systems.

  相似文献   
8.
9.
10.
When male rats were given a single dose of cadmium (Cd) (3.58 mg CdCl2·H2O/kg, ip) 72 hr prior to sacrifice, the testicular 7-ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST) activities toward the substrates 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene (DCNB), ethacrynic acid (EAA), 1,2-epoxy-3-(p-nitrophenoxy)-propane (EPNP), and cumene hydroperoxide (CHPx) decreased significantly as compared to controls. Cd also inhibited reduced glutathione (GSH) level while increasing the lipid peroxidation (LP) level significantly. When the animals were given a single dose of nickel (Ni) (59.5 mg NiCl2·6H2O/kg, ip) 16 hr prior to sacrifice, significant decreases were observed in EROD and GST activities toward CDNB, EAA, EPNP, and CHPx, and GSH level. No significant alterations were noted in DCNB GST activity and LP level by Ni. For the combined treatment, rats received the single dose of Ni 56 hr after the single dose of Cd and were killed 16 hr later. In these animals, lesser depressions were observed on EROD activity and LP level than those of Cd alone. The combination of metals significantly inhibited GST activities and GSH level but not to a greater degree than noted by Cd or Ni alone. Plasma testosterone levels of Cd-, Ni-, and combination-treated rats decreased significantly compared to controls. The strongest depression was achieved by Cd alone. Cd, both alone and in combination with Ni, increased the tissue Ni uptake significantly. Ni, however, did not produce such an effect on the tissue uptake of Cd in either case. Cd treatment caused interstitial edema and coagulation necrosis in seminiferous tubules and also caused fibrinoidal necrosis in vascular endothelium. Ni treatment did not produce any pathological testicular alterations compared to controls. Combined treatment produced fewer pathological alterations (i.e., only interstitial edema) than that of Cd treatment. These results reveal that the combination of Cd and Ni does not have a synergistic effect on testicular xenobiotic metabolizing enzymes, and in contrast, Ni has an ameliorating effect on pathological disturbances caused by Cd alone in the rat testis.  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