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   212篇
  免费   13篇
  2024年   3篇
  2023年   6篇
  2022年   7篇
  2021年   11篇
  2020年   7篇
  2019年   12篇
  2018年   10篇
  2017年   2篇
  2016年   15篇
  2015年   18篇
  2014年   11篇
  2013年   17篇
  2012年   14篇
  2011年   15篇
  2010年   10篇
  2009年   12篇
  2008年   8篇
  2007年   8篇
  2006年   6篇
  2005年   4篇
  2004年   6篇
  2003年   6篇
  2002年   7篇
  2001年   1篇
  1999年   5篇
  1997年   1篇
  1996年   2篇
  1993年   1篇
排序方式: 共有225条查询结果,搜索用时 15 毫秒
111.
The adult human olfactory bulb neural stem/progenitor cells (OBNC/PC) are promising candidate for cell-based therapy for traumatic and neurodegenerative insults. Exogenous application of NGF was suggested as a promising therapeutic strategy for traumatic and neurodegenerative diseases, however effective delivery of NGF into the CNS parenchyma is still challenging due mainly to its limited ability to cross the blood–brain barrier, and intolerable side effects if administered into the brain ventricular system. An effective method to ensure delivery of NGF into the parenchyma of CNS is the genetic modification of NSC to overexpress NGF gene. Overexpression of NGF in adult human OBNSC is expected to alter their proliferation and differentiation nature, and thus might enhance their therapeutic potential. In this study, we genetically modified adult human OBNS/PC to overexpress human NGF (hNGF) and green fluorescent protein (GFP) genes to provide insight about the effects of hNGF and GFP genes overexpression in adult human OBNS/PC on their in vitro multipotentiality using DNA microarray, immunophenotyping, and Western blot (WB) protocols. Our analysis revealed that OBNS/PC-GFP and OBNS/PC-GFP-hNGF differentiation is a multifaceted process involving changes in major biological processes as reflected in alteration of the gene expression levels of crucial markers such as cell cycle and survival markers, stemness markers, and differentiation markers. The differentiation of both cell classes was also associated with modulations of key signaling pathways such MAPK signaling pathway, ErbB signaling pathway, and neuroactive ligand-receptor interaction pathway for OBNS/PC-GFP, and axon guidance, calcium channel, voltage-dependent, gamma subunit 7 for OBNS/PC-GFP-hNGF as revealed by GO and KEGG. Differentiated OBNS/PC-GFP-hNGF displayed extensively branched cytoplasmic processes, a significant faster growth rate and up modulated the expression of oligodendroglia precursor cells markers (PDGFRα, NG2 and CNPase) respect to OBNS/PC-GFP counterparts. These findings suggest an enhanced proliferation and oligodendrocytic differentiation potential for OBNS/PC-GFP-hNGF as compared to OBNS/PC-GFP.  相似文献   
112.

Background

Schistosomiasis, one of the most prevalent neglected tropical diseases, is a life-threatening public health problem in Yemen especially in rural communities. This cross-sectional study aims to determine the prevalence and associated risk factors of schistosomiasis among children in rural Yemen.

Methods/Findings

Urine and faecal samples were collected from 400 children. Urine samples were examined using filtration technique for the presence of Schistosoma haematobium eggs while faecal samples were examined using formalin-ether concentration and Kato Katz techniques for the presence of S. mansoni. Demographic, socioeconomic and environmental information were collected via a validated questionnaire. Overall, 31.8% of the participants were found to be positive for schistosomiasis; 23.8% were infected with S. haematobium and 9.3% were infected with S. mansoni. Moreover, 39.5% of the participants were anaemic whereas 9.5% had hepatosplenomegaly. The prevalence of schistosomiasis was significantly higher among children aged >10 years compared to those aged ≤10 years (P<0.05). Multivariate analysis confirmed that presence of other infected family member (P<0.001), low household monthly income (P = 0.003), using unsafe sources for drinking water (P = 0.003), living nearby stream/spring (P = 0.006) and living nearby pool/pond (P = 0.002) were the key factors significantly associated with schistosomiasis among these children.

Conclusions/Significance

This study reveals that schistosomiasis is still highly prevalent in Yemen. These findings support an urgent need to start an integrated, targeted and effective schistosomiasis control programme with a mission to move towards the elimination phase. Besides periodic drug distribution, health education and community mobilisation, provision of clean and safe drinking water, introduction of proper sanitation are imperative among these communities in order to curtail the transmission and morbidity caused by schistosomiasis. Screening and treating other infected family members should also be adopted by the public health authorities in combating this infection in these communities.  相似文献   
113.
114.
Neural stem cells (NSC) with self-renewal and multipotent properties serve as an ideal cell source for transplantation to treat neurodegenerative insults such as Parkinson's disease. We used Agilent's and Illumina Whole Human Genome Oligonucleotide Microarray to compare the genomic profiles of human embryonic NSC at a single time point in culture, and a multicellular tissue from postmortem adult substantia nigra (SN) which are rich in dopaminergic (DA) neurons. We identified 13525 up-regulated genes in both cell types of which 3737 (27.6%) genes were up-regulated in the hENSC, 4116 (30.4%) genes were up-regulated in the human substantia nigra dopaminergic cells, and 5672 (41.93%) were significantly up-regulated in both cell population. Careful analysis of the data that emerged using DAVID has permitted us to distinguish several genes and pathways that are involved in dopaminergic (DA) differentiation, and to identify the crucial signaling pathways that direct the process of differentiation. The set of genes expressed more highly at hENSC is enriched in molecules known or predicted to be involved in the M phase of the mitotic cell cycle. On the other hand, the genes enriched in SN cells include a different set of functional categories, namely synaptic transmission, central nervous system development, structural constituents of the myelin sheath, the internode region of axons, myelination, cell projection, cell somata, ion transport, and the voltage-gated ion channel complex. Our results were also compared with data from various databases, and between different types of arrays, Agilent versus Illumina. This approach has allowed us to confirm the consistency of our obtained results for a large number of genes that delineate the phenotypical differences of embryonic NSCs, and SN cells.  相似文献   
115.
Cow serum proteome was evaluated by three different complementary approaches in the control group, subclinical and clinical mastitis in order to possibly find differential protein expression useful for a better understanding of the pathophysiology of mastitis as well as for an early diagnosis of the disease. The systemic inflammatory and oxidative stress response in cows with subclinical and clinical mastitis were observed. The collected evidence shows a differential protein expression of serpin A3-1, vitronectin-like protein and complement factor H in subclinical mastitis in comparison with the control. It was also found a differential protein expression of inter-alpha-trypsin inhibitor heavy chain H4, serpin A3-1, C4b-binding protein alpha chain, haptoglobin and apolipoprotein A-I in clinical mastitis compared to the control. Among the inflammatory proteins up-regulated in clinical mastitis, vitronectin is over-expressed in both subclinical and clinical mastitis indicating a strong bacterial infection. This suggests vitronectin as an important mediator in the pathogenesis of the onset of mastitis as well as a valuable marker for diagnosis of the subclinical form of the disease. Obtained data could be useful for the detection of mastitis during the subclinical phase and for a better comprehension of the pathophysiological mechanisms involved in the onset of the disease.  相似文献   
116.
Host resistance to “yellow dwarf” or “moonlight” disease cause by any population (Hg type) of Heterodera glycines I., the soybean cyst nematode (SCN), requires a functional allele at rhg1. The host resistance encoded appears to mimic an apoptotic response in the giant cells formed at the nematode feeding site about 24–48 h after nematode feeding commences. Little is known about how the host response to infection is mediated but a linked set of 3 genes has been identified within the rhg1 locus. This study aimed to identify the role of the genes within the locus that includes a receptor-like kinase (RLK), a laccase and an ion antiporter. Used were near isogeneic lines (NILs) that contrasted at their rhg1 alleles, gene-based markers, and a new Hg type 0 and new recombination events. A syntenic gene cluster on Lg B1 was found. The effectiveness of SNP probes from the RLK for distinguishing homolog sequence variants on LgB1 from alleles at the rhg1 locus on LgG was shown. The resistant allele of the rhg1 locus was shown to be dominant in NILs. None of the recombination events were within the cluster of the three candidate genes. Finally, rhg1 was shown to reduce the plant root development. A model for rhg1 as a dominant multi-gene resistance locus based on the developmental control was inferred.  相似文献   
117.
Mevinolin (MVN) has been used clinically for the treatment of hypercholesterolemia with very good tolerance by patients. Based on epidemiological evidences, MVN was suggested strongly for the treatment of neoplasia. Early experimental trials suggested the mixed apoptotic/necrotic cell death pathway was activated in response to MVN exposure. Herein, the cytotoxic profile of MVN was evaluated, compared to the robust and frequently used anti-cancer drug doxorubicin (DOX), against breast (MCF-7), cervical (HeLa) and liver (HepG(2)) transformed cell lines. MVN was showed comparable results in cytotoxic profile with DOX in all tested solid tumor cell lines. In addition, the MVN-induced cytotoxicity was inferred to be multi-factorial and not solely dependent on p53 expression. It was concluded that molecular and genetic assessment of MVN-induced cell death would be useful for developing cancer therapeutic treatments.  相似文献   
118.
Aizoaceae is one of the most important and widespread succulent plant families in both tropical/subtropical regions and arid zones. In this study, 27 species were collected from various floristic regions in Egypt, Kingdom of Saudi Arabia and cactus farms (Kalupia – Egypt). The morphological characteristics of every taxon were recorded. The important morphological features included: the number of leaves per plant; leaf types; leaf position (cauline or radical; the latter indicates leaves arising from, or near, the roots); leaf arrangement; petiolate or sessile leaves; leaf sheath present or absent; leaf shape; leaf margin; leaf tip; presence of leaf ‘window area’; leaf texture; and presence of white or dark miniscule dots (white miniscule dots from calcium carbonate and dark miniscule dots from tannin sacs). The investigated anatomical features were as follows: shape of the transverse section; the type of epidermal cells; the presence of large epidermal cells (bladder cells); presence of papilla and simple hairs; presence of tannin sacs; shapes of calcium oxalate crystals; shape of the xylem vessels; and the presence of Kranz unit (the unit that constitutes the vascular bundle/s, parenchyma sheath, and surrounding mesophyll) or collenchyma sheath. All data were recorded in a data matrix (as either text or numerical data), which was used to construct the identification key and phylogeny tree using a multi-variate statistical package. The results of our analysis may open the possibility of using the morphological and anatomical features of leaves to distinguish between the subfamilies, genera, and species of Aizoaceae.  相似文献   
119.
Accumulating evidence has indicated the implication of angiotensin II in the pathogenesis of inflammatory bowel diseases (IBD) via its proinflammatory features. Telmisartan (TLM) is an angiotensin II receptor antagonist with marked anti-inflammatory and antioxidant actions that mediated its cardio-, reno- and hepatoprotective actions. However, its impact on IBD has not been previously explored. Thus, we aimed to investigate the potential alleviating effects of TLM in tri-nitrobenezene sulphonic acid (TNBS)-induced colitis in rats. Pretreatment with TLM (10 mg/kg p.o.) attenuated the severity of colitis as evidenced by decrease of disease activity index (DAI), colon weight/length ratio, macroscopic damage, histopathological findings and leukocyte migration. TLM suppressed the inflammatory response via attenuation of tumor necrosis factor-α (TNF-α), prostaglandin E2 (PGE2) and myeloperoxidase (MPO) activity as a marker of neutrophil infiltration besides restoration of interleukin-10 (IL-10). TLM also suppressed mRNA and protein expression of nuclear factor kappa B (NF-κB) p65 and mRNA of cyclo-oxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) proinflammatory genes with concomitant upregulation of PPAR-γ. The alleviation of TLM to colon injury was also associated with inhibition of oxidative stress as evidenced by suppression of lipid peroxides and nitric oxide (NO) besides boosting glutathione (GSH), total anti-oxidant capacity (TAC) and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx). With respect to apoptosis, TLM downregulated the increased mRNA, protein expression and activity of caspase-3. It also suppressed the elevation of cytochrome c and Bax mRNA besides the upregulation of Bcl-2. Together, these findings highlight evidences for the beneficial effects of TLM in IBD which are mediated through modulation of colonic inflammation, oxidative stress and apoptosis.  相似文献   
120.
Despite its broad applications, cisplatin affords considerable nephro- and hepatotoxicity through triggering inflammatory and oxidative stress cascades. The aim of the current investigation was to study the possible protective effects of tangeretin on cisplatin-induced hepatotoxicity. The impact of tangeretin on cisplatin-evoked hepatic dysfunction and histopathologic changes along with oxidative stress, inflammatory and apoptotic biomarkers were investigated compared to silymarin. Tangeretin pre-treatment significantly improved liver function tests (ALT and AST), inhibited cisplatin-induced lipid profile aberrations (total cholesterol and triglycerides) and diminished histopathologic structural damage in liver tissues. Tangeretin also attenuated cisplatin-induced hepatic inflammatory events as indicated by suppression of tumor necrosis factor-α (TNF-α) and enhancement of interleukin-10 (IL-10). Meanwhile, it lowered malondialdehyde (MDA), nitric oxide (NO) and nuclear factor erythroid 2-related factor 2 (NRF-2) levels with restoration of glutathione (GSH), and glutathione peroxidase (GPx). Regarding mitogen-activated protein kinase (MAPK) pathway, tangeretin attenuated cisplatin-induced increase in phospho-p38, phospho-c-Jun N-terminal kinase (p-JNK) and phospho-extracellular signal-regulated kinase (p-ERK1/2) in liver tissues. In addition, tangeretin downregulated Bax expression with augmentation of Bcl-2 promoting liver cell survival. Our results highlight the protective effects of tangeretin against cisplatin-induced acute hepatic injury via the concerted modulation of inflammation, oxidative stress, MAPKs and apoptotic pathways.  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