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   97篇
  免费   3篇
  2023年   1篇
  2022年   2篇
  2021年   6篇
  2020年   3篇
  2019年   2篇
  2018年   3篇
  2017年   4篇
  2016年   4篇
  2015年   8篇
  2014年   11篇
  2013年   8篇
  2012年   11篇
  2011年   8篇
  2010年   5篇
  2009年   3篇
  2008年   7篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  2004年   1篇
  2003年   2篇
  2002年   3篇
  2000年   1篇
  1999年   2篇
  1998年   1篇
  1995年   1篇
排序方式: 共有100条查询结果,搜索用时 218 毫秒
91.
The present work reports the preparation of activated carbon fiber (ACF) from Kenaf natural fibers. Taguchi experimental design method was used to optimize the preparation of ACF using K2HPO4. Optimized conditions were: carbonization at 300 °C, impregnation with 30% w/v K2HPO4 solution and activation at 700 °C for 2 h with the rate of achieving the activation temperature equal to 2 °C min−1. The surface characteristics of the ACF prepared at optimized conditions were also studied using pore structure analysis, scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. Pore structure analysis shows that micropores constitute the most of the porosity of the prepared ACF. The ability of the ACF prepared at optimized conditions to adsorb phenol and p-nitrophenol from aqueous solution was also investigated. The equilibrium data of phenol and p-nitrophenol adsorption on the prepared ACF were well fitted to the Langmuir isotherm. The maximum adsorption capacities of phenol and p-nitrophenol on the prepared ACF are 140.84 and 136.99 mg g−1, respectively. The adsorption process follows the pseudo-first-order kinetic model.  相似文献   
92.
The terpenoids, or isoprenoids, are a large family of natural products that are best known as constituents of the essential oils in plants. Because of their pleasant flavor and aromatic properties, essential oils have an economic importance in perfumery, cosmetic, pharmaceutical and various other industries. However, expression profiles of regulatory genes in essential oil production have not been dissected entirely, which may be an interesting topic of future research. In this report, we review recent studies on isoprenoids biosynthesis in plants. We also discuss the progress of our recent research activities on isoprenoid studies.  相似文献   
93.
Polycystic ovary syndrome (PCOS) is the most common hormonal imbalance disease in reproductive‐aged women. Its basic characteristics are ovulatory dysfunction and ovarian overproduction of androgens that lead to severe symptoms such as insulin resistance, hirsutism, infertility, and acne. Notwithstanding the disease burden, its underlying mechanisms remain unknown, and no causal therapeutic exists. In recent years, further studies showed that inflammation processes are involved in ovulation and play a key role in ovarian follicular dynamics. Visceral adipose tissue can cause inflammatory response and maintenance of the inflammation state in adipocytes by augmented production of inflammatory cytokines, monocyte chemoattractant proteins, and recruitment of the immune cell. Therefore, the PCOS can be related to a low‐grade inflammation state and inflammatory markers. Investigating the inflammatory processes and mediators that contribute to the commencement and development of PCOS can be a critical step for better understanding the pathophysiology of the disease and its treatment through inhibition or control of related pathways. In the present review, we discuss the pathophysiological roles of chronic low‐grade inflammation mediators including inflammasome‐related cytokines, interleukin‐1β (IL‐1β), and IL‐18 in PCOS development.  相似文献   
94.
Peptide presentation by bacteriophage P4   总被引:1,自引:0,他引:1  
Abstract: This article focuses on bacteriophage P4 as a potential peptide display phage by exploring the possibility of using the P4 capsid decoration component, Psu, as a peptide carrier protein. Psu is non-essential for P4 growth but it enhances the stability of the P4 capsid by binding to its exterior. We have constructed a unique Sac I cloning site in the beginning of the psu gene. This site changes the third amino acid of Psu from Ser to Leu. This substitution does not destroy the binding of Psu to the P4 capsid. A synthetic oligonucleotide encoding a 10-amino acid peptide whose sequence is part of the human p62c-myc protein, has been inserted into the Sac I site. The Psuc-myc shows full capsid binding activity and reacts with monoclonal antibodies directed against the c-myc peptide. These results pave the way for the further development of a peptide display system based on bacteriophage p4.  相似文献   
95.
96.

Rabies virus (RABV) is a neurotropic virus exclusively infecting neurons in the central nervous system. RABV encodes five proteins. Among them, the viral glycoprotein (RVG) plays a key role in viral entry into neurons and rabies pathogenesis. It was shown that the nature of the C-terminus of the RABV G protein, which possesses a PDZ-binding motif (PBM), modulates the virulence of the RABV strain. The neuronal protein partners recruited by this PBM may alter host cell function. This study was conducted to investigate the effect of RVG on synaptic function in the hippocampal dentate gyrus (DG) of rat. Two μl (108 T.U./ml) of the lentiviral vector containing RVG gene was injected into the DG of rat hippocampus. After 2 weeks, the rat’s brain was cross-sectioned and RVG-expressing cells were detected by fluorescent microscopy. Hippocampal synaptic activity of the infected rats was then examined by recording the local field potentials from DG after stimulation of the perforant pathway. Short-term synaptic plasticity was also assessed by double pulse stimulation. Expression of RVG in DG increased long-term potentiation population spikes (LTP-PS), whereas no facilitation of LTP-PS was found in neurons expressing δRVG (deleted PBM). Furthermore, RVG and δRVG strengthened paired-pulse facilitation. Heterosynaptic long-term depression (LTD) in the DG was significantly blocked in RVG-expressing group compared to the control group. This blockade was dependent to PBM motif as rats expressing δRVG in the DG-expressed LTD comparable to the RVG group. Our data demonstrate that RVG expression facilitates both short- and long-term synaptic plasticity in the DG indicating that it may involve both pre- and postsynaptic mechanisms to alter synaptic function. Further studies are needed to elucidate the underlying mechanisms.

  相似文献   
97.
Chlorpyrifos (CPF), an organophosphate insecticide has a wider application throughout the world to protect agricultural crops and vegetables from insects. Polyphenolic compounds are considered as beneficial against toxicities induced by organophosphates. The present study was conducted to understand the neuroprotective role of quercetin in chlorpyrifos‐induced apoptotic events in rats. Twenty‐four male Sprague Dawley rats weighing 170 to 200 g were divided into four groups viz: Control, chlorpyrifos treated (13.5 mg/kg body wt. alternate day), quercetin treated (50 mg/kg body wt. every day) and combined chlorpyrifos + quercetin treated. All the treatments were carried out for a total duration of 60 days. Protein carbonyl content and acetylcholinesterase activity were estimated in serum along with cerebrum and cerebellum to ascertain neurotoxicity. Further, for appraisal of neurodegeneration as a consequence of apoptosis, protein expressions of Bcl‐2, Bax, cytochrome c, caspase‐8, and caspase‐9 were assessed. The results showed that protein carbonyl contents were markedly increased in both serum and brain tissues (cerebrum and cerebellum) of chlorpyrifos‐treated rats when compared with control group and were appreciably improved upon simultaneous supplementation with quercetin. Further, chlorpyrifos treatment revealed a significant decrease in the enzyme activity of acetylcholinesterase in serum as well as in cerebrum and cerebellum, which however was increased upon concomitant treatment with quercetin. In chlorpyrifos‐treated animals, we have observed a significant decrease in the protein expression level of Bcl‐2, but a remarkable increase in the expression levels of Bax, cytochrome c, caspase‐8, and caspase‐9 in both cerebrum and cerebellum. Interestingly, when chlorpyrifos‐treated animals were supplemented with quercetin, a significant increase in the expression of Bcl‐2 and an appreciable decline in the expression levels of Bax, cytochrome c, caspase‐8, and caspase‐9 was observed. In conclusion, the present study advocates that quercetin may prove to be a useful candidate in containing the oxidative‐induced apoptotic events during chlorpyrifos exposure.  相似文献   
98.
Cardiovascular aging presents a formidable challenge, as the aging process can lead to reduced cardiac function and heightened susceptibility to cardiovascular diseases. Consequently, there is an escalating, unmet medical need for innovative and effective cardiovascular regeneration strategies aimed at restoring and rejuvenating aging cardiovascular tissues. Altered redox homeostasis and the accumulation of oxidative damage play a pivotal role in detrimental changes to stem cell function and cellular senescence, hampering regenerative capacity in aged cardiovascular system. A mounting body of evidence underscores the significance of targeting redox machinery to restore stem cell self-renewal and enhance their differentiation potential into youthful cardiovascular lineages. Hence, the redox machinery holds promise as a target for optimizing cardiovascular regenerative therapies. In this context, we delve into the current understanding of redox homeostasis in regulating stem cell function and reprogramming processes that impact the regenerative potential of the cardiovascular system. Furthermore, we offer insights into the recent translational and clinical implications of redox-targeting compounds aimed at enhancing current regenerative therapies for aging cardiovascular tissues.  相似文献   
99.
Molecular Biology Reports - Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and abnormal insulin secretion. MicroRNAs are small, non-coding RNAs that are able to affect...  相似文献   
100.
In this paper, we propose a novel ECG arrhythmia classification method using the complementary features of Mixture of Experts (ME) and Negatively Correlated Learning (NCL). Negative Correlation Learning and Mixture of Experts methods utilize different error functions for simultaneous training of negatively correlated Neural Networks. The capability of a control parameter for NCL is incorporated in the error function of ME, which enables the training algorithm of ME to establish a balance in bias-variance-covariance trade-offs. ECG records from the MIT-BIH arrhythmia database are selected as test data. It is observed that the proposed classification method not only preserves the advantages and alleviates the disadvantages of its basis approaches, but also offering significantly improved performance over the original methods.  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