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排序方式: 共有2946条查询结果,搜索用时 156 毫秒
11.
Youngpyo Nam Gyeong Joon Moon Sang Ryong Kim 《International journal of molecular sciences》2021,22(6)
Neurotrophic factors (NTFs) are essential for cell growth, survival, synaptic plasticity, and maintenance of specific neuronal population in the central nervous system. Multiple studies have demonstrated that alterations in the levels and activities of NTFs are related to the pathology and symptoms of neurodegenerative disorders, such as Parkinson’s disease (PD), Alzheimer’s disease (AD), and Huntington’s disease. Hence, the key molecule that can regulate the expression of NTFs is an important target for gene therapy coupling adeno-associated virus vector (AAV) gene. We have previously reported that the Ras homolog protein enriched in brain (Rheb)–mammalian target of rapamycin complex 1 (mTORC1) axis plays a vital role in preventing neuronal death in the brain of AD and PD patients. AAV transduction using a constitutively active form of Rheb exerts a neuroprotective effect through the upregulation of NTFs, thereby promoting the neurotrophic interaction between astrocytes and neurons in AD conditions. These findings suggest the role of Rheb as an important regulator of the regulatory system of NTFs to treat neurodegenerative diseases. In this review, we present an overview of the role of Rheb in neurodegenerative diseases and summarize the therapeutic potential of AAV serotype 1 (AAV1)-Rheb(S16H) transduction in the treatment of neurodegenerative disorders, focusing on diseases, such as AD and PD. 相似文献
12.
Jianwu Zhou Qiangfeng Chen Junkang Sang Rongmin Wu Zhuobin Li Wanbing Guan 《金属学报(英文版)》2021,34(5):668-674
Conductivity and oxidation behavior of Fe-16Cr alloy were investigated under long-term stability operation at 750℃ and thermal cycles from room temperature to 750℃.The results showed that the area specific resistance (ASR) of Fe-16Cr alloy increased over time and reached about 56.29 mΩcm ~(2 )after 40,000 h of long-term stability operation at 750℃ by theoretical calculation.The ASR of Fe-16Cr remained about 11 mΩcm ~(2 )after 52 thermal cycles from room temperature to750℃.The analysis of structure showed that the oxidized phase on the surface of Fe-16Cr was mainly composed of Cr _(2 )O _3and Fe Cr _(2 )O _(4 )spinel phase under long-term stability operation at 750℃.While the Cr _(2 )O _(3 )phase was mainly observed on the surface of Fe-16Cr alloy after 52 thermal cycles,the oxidation rates of Fe-16Cr alloy were 0.0142μm h~(-1 )and 0.06μm cycle~(-1 )under long-term stability operation and under thermal cycle,respectively.The property of Fe-16Cr alloy with 2.6 mm thickness met the lifespan requirement of interconnect for solid oxide fuel cell (SOFC) stacks.The Cr element all diff used onto oxidation surface,indicating that it was necessary to spray a coating on the surface to avoid poisoning cell cathode of SOFCs.Two 2-cell stacks were assembled and tested to verify the properties of Fe-16Cr alloy as SOFC interconnect under long-term stability operation and thermal cycle condition. 相似文献
13.
Ahmad Hosseini-Bandegharaei Mohammad Karimzadeh Masoud Sarwghadi Aliasghar Heydarbeigi Seyyed Hossein Hosseini Mehdi Nedaie Hassan Shoghi 《Chemical Engineering Research and Design》2014
Adsorption of Pb(II) ion by a novel extractant-impregnated resin, EIR, was studied as a function of various experimental parameters using batch adsorption experiments. The new EIR was prepared by impregnating gallocyanine (GCN) onto Amberlite XAD-16 resin beads. The EIR was characterized by nitrogen analysis and SEM micrographs. The new EIR showed excellent selectivity factor values (α) for Pb(II) adsorption respect to other metal ions. The effects of some chemical and physical variables were evaluated and the optimum conditions were found for Pb(II) removal from aqueous solutions. The equilibrium adsorption isotherm was fitted with the Langmuir adsorption model. The maximum adsorption capacity (qmax) of EIR for Pb(II) ions was found to be 367.92 mg g−1. The kinetic studies showed that the intra-particle diffusion is the rate-controlling step. Also, the intra-particle diffusion coefficients, Dip values, were of the order of 10−12 m2 s−1. The values of enthalpy (ΔH°) were positive, which confirms the endothermic nature of adsorption process. Also, the positive entropy changes (ΔS°) were showed that the randomness increased along with the adsorption process. In addition, the obtained negative values of Gibbs free energy (ΔG°) indicated feasible and spontaneous nature of the adsorption process at different temperatures. The new adsorbent was very stable so that it can be successfully used for many consecutive cycles without significant loss in its adsorption capacity. 相似文献
14.
Cong-Cong Shen Yu-Huan Kang Ming Zhao Yi He Dan-Dan Cui Yu-Yin Fu Ling-Lin Yang Lan-Tu Gou 《International journal of molecular sciences》2014,15(7):12928-12939
Treatment for cancer can induce a series of secreted factors into the tumor microenvironment, which can affect cancer progression. Wingless-type MMTV (mouse mammary tumor virus) integration site 16B (WNT16B) is a new member of the WNT family and has been reported to play growth-related roles in previous studies. In this study, we found WNT16B could be expressed and secreted into the microenvironment by human ovarian fibroblasts after DNA damage-associated treatment, including chemotherapy drugs and radiation. We also demonstrated that fibroblast-derived WNT16B could result in accumulation of β-catenin in dendritic cells and secretion of interleukin-10 (IL-10) and transforming growth factor beta (TGF-β), which contributed to the differentiation of regulatory T cells in a co-culture environment. These results shed light on the roles of WNT16B in immune regulation, especially in regard to cancer treatment. 相似文献
15.
Sin Hang Lee Jessica S. Vigliotti Veronica S. Vigliotti William Jones David M. Shearer 《International journal of molecular sciences》2014,15(3):4284-4298
The diagnoses of Lyme disease based on clinical manifestations, serological findings and detection of infectious agents often contradict each other. We tested 52 blind-coded serum samples, including 20 pre-treatment and 12 post-treatment sera from clinically suspect Lyme disease patients, for the presence of residual Lyme disease infectious agents, using nested PCR amplification of a signature segment of the borrelial 16S ribosomal RNA gene for detection and direct DNA sequencing of the PCR amplicon for molecular validation. These archived sera were split from the samples drawn for the 2-tier serology tests performed by a CDC-approved laboratory, and are used as reference materials for evaluating new diagnostic reagents. Of the 12 post-treatment serum samples, we found DNA evidence of a novel borrelia of uncertain significance in one, which was also positive for the 2-tier serology test. The rest of the post-treatment sera and all 20 control sera were PCR-negative. Of the 20 pre-treatment sera from clinically suspect early Lyme disease patients, we found Borrelia miyamotoi in one which was 2-tier serology-negative, and a Borrelia burgdorferi in two—one negative and one positive for 2-tier serology. We conclude that a sensitive and reliable DNA-based test is needed to support the diagnosis of Lyme disease and Lyme disease-like borreliosis. 相似文献
16.
目的 提高D16T铝合金的耐磨损性能。方法 通过向硅酸盐和磷酸盐混合电解液体系中添加2 g/L纳米TiO2添加剂,利用微弧氧化技术在其表面制备微弧氧化陶瓷膜。采用X射线衍射仪(XRD)、扫描电镜(SEM)、能谱分析仪(EDS)、显微硬度计、厚度测试仪、摩擦磨损试验机等,研究了纳米TiO2添加剂对D16T铝合金微弧氧化膜的结构和耐磨损性能的影响及机理。结果 纳米TiO2的添加使得微弧氧化膜层的表面变得更加平整、致密,具有更少的微孔和裂纹,大大改善了膜层结构。相比于未添加纳米TiO2的电解液中制得的微弧氧化膜,在含纳米TiO2的电解液中所制得的微弧氧化膜中有新相TiO2生成,并且促使更多的α-Al2O3相和γ-Al2O3相生成,使膜层厚度得到明显增加,膜厚达31.2 μm,显微硬度也得到显著提高,达510HV。纳米TiO2的添加,降低了D16T微弧氧化膜层试样的摩擦系数,平均摩擦系数为0.45,明显低于不含纳米TiO2的D16T微弧氧化膜层试样的摩擦系数(0.75)。结论 加入到电解液中的纳米TiO2在微弧氧化反应过程中已进入到所形成的氧化膜层,并且填充了膜层中的微孔和裂纹,改善了膜层结构,增加了膜层厚度,显著提高了微弧氧化膜层的显微硬度和耐磨损性能。 相似文献
17.
Characterization of nitrogen-fixing cyanobacteria in the Brazilian Amazon floodplain 总被引:1,自引:0,他引:1
Fiore Mde F Neilan BA Copp JN Rodrigues JL Tsai SM Lee H Trevors JT 《Water research》2005,39(20):5017-5026
The diversity of the free-living nitrogen-fixing cyanobacterial community in the floodplain sediments along the Solimões and Amazon Rivers and some of their tributaries (Japurá, Negro and Madeira) was investigated. Five cyanobacterial genera were morphologically identified, four of which (Nostoc, Calothrix, Cylindrospermum and Fischerella) have not previously been isolated from the Brazilian Amazon floodplain. Nostoc strains were the most commonly found heterocyst-forming cyanobacteria. Five strains (N. muscorum CENA18 and CENA61, N. piscinale CENA21, Cylindrospermum sp. CENA33 and Fischerella sp. CENA19) were selected for growth measurement, ability to fix N2 and phylogenetic analysis, based on their widespread distribution and morphological distinction. Molecular analyses employing 16S rRNA sequences indicated that some of the isolates may represent novel cyanobacterial species. Dinitrogen fixed by these strains was measured indirectly as acetylene reduction activity and ranged from 11.5 to 22.2 nmol C2H4 μg Chl a−1 h−1. These results provide evidence of widespread and importance of nitrogen-fixing cyanobacteria as a source of N inputs in the Amazonian ecosystem. 相似文献
18.
Akarsubasi AT Ince O Kirdar B Oz NA Orhon D Curtis TP Head IM Ince BK 《Water research》2005,39(8):1576-1584
Distribution and occurrence of Archaea and methanogenic activity in a laboratory scale, completely mixed anaerobic reactor treating pharmaceutical wastewaters were investigated and associated with reactor performance. The reactor was initially seeded with anaerobic digester sludge from an alcohol distillery wastewater treatment plant and was subjected to a three step feeding strategy. The feeding procedure involved gradual transition from a glucose containing feed to a solvent stripped pharmaceutical wastewater and then raw pharmaceutical wastewater. During the start-up period, over 90% COD removal efficiency at an organic loading rate (OLR) of 6 kg COD m(-3)d(-1) was achieved with glucose feeding, and acetoclastic methanogenic activity was 336 ml CH4 gTVS(-1)d(-1). At the end of the primary loading, when the feed contained solvent stripped pharmaceutical wastewater at full composition, 71% soluble COD removal efficiency was obtained and acetoclastic methanogenic activity decreased to half of the rate under glucose feed (166 ml CH4 gTVS(-1)d(-1)). At the end of secondary loading with 60% (w/v) raw pharmaceutical wastewater, COD removal dropped to zero and acetoclastic methanogenic activity fell to less than 10 ml CH4 gTVS(-1)d(-1). Throughout the course of the experiment, microbial community structure was monitored by DGGE analysis of 16S rRNA gene fragments. Five different archaeal taxa were identified and the predominant archaeal sequences belonged to methanogenic Archaea. Two of these showed greatest sequence identity with Methanobacterium formicicum and Methanosaeta concilii. The types of Archaea present changed little in response to changing feed composition but the relative contribution of different organisms identified in the archaeal DGGE profiles did change. 相似文献
19.
20.
Molecular characterization of the microbial community structure in two activated sludge systems for the advanced treatment of domestic effluents 总被引:19,自引:0,他引:19
Although activated sludge systems with enhanced biological phosphorus removal (EBPR) represent state-of-the-art technology for phosphate removal from wastewater it is still unknown which species of bacteria are responsible for the EBPR process. The aim of this study was to compare the bacterial composition of activated sludge from two laboratory plants with different modes of operation, anoxic/oxic- (EBPR, no nitrification) and Phoredox-system (EBPR, nitrification and denitrification) with particular emphasis on microorganisms responsible for EBPR process. In addition to fluorescence in situ hybridization (FISH), we applied further rRNA-based molecular techniques like terminal restriction-fragment length polymorphism analysis and comparative 16S rDNA analysis to yield additional information and to verify the results from FISH analysis, like e.g. for the identification of polyphosphate accumulating organisms (PAO). Despite the different modes of operation only minor differences in the bacterial composition were detected by FISH analysis based on the probes used in this study. In contrast T-RFLP analysis yielded characteristic community fingerprints for each of the investigated plants and comparative 16S rDNA analysis indicated highly diverse microbial communities in both plants suggesting substantial differences in the microbial structure. The results obtained by FISH analysis with specific probes for PAOs support the presumption that not only one specific organism is responsible for the EBPR. In our case Tetrasphaera spp. dominated the PAO community, but other possible PAOs, like Microlunatus spp. and members of the Rhodocyclus group, were also detected. 相似文献