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961.
Two kinds of free‐standing electrodes, reduced graphene oxide (rGO)‐wrapped Fe‐doped MnO2 composite (G‐MFO) and rGO‐wrapped hierarchical porous carbon microspheres composite (G‐HPC) are fabricated using a frozen lake‐inspired, bubble‐assistance method. This configuration fully enables utilization of the synergistic effects from both components, endowing the materials to be excellent electrodes for flexible and lightweight electrochemical capacitors. Moreover, a nonaqueous HPC‐doped gel polymer electrolyte (GPE‐HPC) is employed to broad voltage window and improve heat resistance. A fabricated asymmetric supercapacitor based on G‐MFO cathode and G‐HPC anode with GPE‐HPC electrolyte achieves superior flexibility and reliability, enhanced energy/power density, and outstanding cycling stability. The ability to power light‐emitting diodes also indicates the feasibility for practical use. Therefore, it is believed that this novel design may hold great promise for future flexible electronic devices.  相似文献   
962.
A new 2,5‐diphenyl‐1,3,4‐oxadiazole‐based derivative (L) was synthesized and applied as a highly selective and sensitive fluorescent sensor for relay recognition of Cu2+ and S2? in water (Tris–HCl 10 mM, pH = 7.0) solution. L exhibits an excellent selectivity to Cu2+ over other examined metal ions with a prominent fluorescence ‘turn‐off’ at 392 nm. L interacts with Cu2+ through a 1:2 binding stoichiometry with a detection limit of 4.8 × 10–7 M. The on‐site formed L–2Cu2+ complex exhibits excellent selectivity to S2? with a fluorescence ‘off–on’ response via a Cu2+ displacement approach. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
963.
多肉植物劳尔的组织培养   总被引:4,自引:0,他引:4  
以多肉植物劳尔(Sedum clavatum)叶片为外植体, 通过诱导愈伤组织、愈伤组织分化新芽、芽生根和无菌苗移栽等步骤建立劳尔无菌苗快速繁殖体系。研究结果表明, 诱导劳尔叶片愈伤组织的最佳培养基为MS+3.0 mg·L–1 6-BA+0.1mg·L–1 NAA+1 mg·L–1 KT, 诱导率达95.7%; 愈伤组织诱导分化新芽的最佳培养基为3/4MS+3.0 mg·L–1 6-BA+0.3 mg·L–1NAA, 分化率达80%; 芽生根的最佳培养基为1/2MS+0.03 mg·L–1 NAA, 生根率可达94.89%; 采用珍珠岩:蛭石(1:2)作为基质移栽培养生根苗, 成活率达90%以上。实验成功建立了劳尔快速繁殖体系。  相似文献   
964.
Tang  Ying  Li  Yingqin  Yu  Guangyin  Ling  Zemin  Zhong  Ke  Zilundu  Prince L. M.  Li  Wenfu  Fu  Rao  Zhou  Li-Hua 《Cellular and molecular neurobiology》2021,41(6):1373-1387

The imbalance between excess reactive oxygen species (ROS) generation and insufficient antioxidant defenses contribute to a range of neurodegenerative diseases. High ROS levels damage cellular macromolecules such as DNA, proteins and lipids, leading to neuron vulnerability and eventual death. However, the underlying molecular mechanism of the ROS regulation is not fully elucidated. Recently, an increasing number of studies suggest that microRNAs (miRNAs) emerge as the targets in regulating oxidative stress. We recently reported the neuroprotective effect of miR-137-3p for brachial plexus avulsion-induced motoneuron death. The present study is sought to investigate whether miR-137-3p also could protect PC12 cells against hydrogen peroxide (H2O2) induced neurotoxicity. By using cell viability assay, ROS assay, gene and protein expression assay, we found that PC-12 cells exposed to H2O2 exhibited decreased cell viability, increased expression levels of calpain-2 and neuronal nitric oxide synthase (nNOS), whereas a decreased miR-137-3p expression. Importantly, restoring the miR-137-3p levels in H2O2 exposure robustly inhibited the elevated nNOS, calpain-2 and ROS expression levels, which subsequently improved the cell viability. Furthermore, the suppressive effect of miR-137-3p on the elevated ROS level under oxidative stress was considerably blunted when we mutated the binding site of calpain-2 targted by miR-137-3p, suggesting the critical role of calpain-2 involving the neuroprotective effect of miR-137-3p. Collectively, these findings highlight the neuroprotective role of miR-137-3p through down-regulating calpain and NOS activity, suggesting its potential role for combating oxidative stress insults in the neurodegenerative diseases.

  相似文献   
965.
用免疫荧光单克隆抗体对脊髓灰质炎病毒抗原表位的分析   总被引:1,自引:0,他引:1  
用间接免疫荧光与中和试验筛选出来的抗脊髓灰质炎2型与3型不同毒株的12个单克隆抗体,其中3个仅有免疫荧光活性,9个具有中和与免疫荧光活性。用免疫荧光活性的单克隆抗体进行试验,发现它们在识别特异性抗原表位方面与中和性单克隆抗体相似,显示出株特异的、几个毒株共同特异的或型特异的抗原表位。根据表位分布关系及特征,可以用来鉴别型内毒株的特征、毒株的抗原分析、抗原变异的研究以及疫苗相关病例的鉴别。所得结果与中和性单克抗隆抗体及T1-寡核苷酸指纹图谱分析一致。而免疫荧光单克隆抗体识别抗原表位的活性范围比中和性单克隆抗体更广。另外还发现某些兼有荧光与中和两活性的同一个单克隆抗体,用不同方法(IF与NT)进行试验时,与相同毒株出现不同表位反应,这点是值得引起注意需待进一步证实的重要问题。  相似文献   
966.
湿地松(Pinus elliottii)是阳性乔木,茶树(Camellia sinensis)是阴性灌木。这两种树种间作,形成针阔、乔灌两层树冠结构的茶园复合生态系统,可以改善茶树生态条件,提高茶叶的产量和品质。但间作存在胁地现象。一般认为这是上层树木的过度遮荫和根系间的竞争造成的。为了解这两种树种根系的分布状况和相互关系,并为间作茶园的合理配置和加强这种茶园的耕作管理提供依据,我们进行了湿地松与茶树间作根系分布状况的研究。  相似文献   
967.
斯氏狸殖吸虫螺类宿主新记录:洪山拟钉螺新种记述   总被引:2,自引:0,他引:2  
本文报道斯氏狸殖吸虫新的螺类宿主——洪山拟钉螺Tricula hongshanensis sp. nov.的特点:螺壳较宽而短,体螺层较高大,壳口上缘成锐角,触角伸展时较长,收缩吋有环状皱褶,雄性阴茎较粗短,末端钝圆,齿舌公式不同于其它拟钉螺。  相似文献   
968.
Mitochondrial dysfunction plays a central role in glutamate-evoked neuronal excitotoxicity, and mitochondrial fission/fusion dynamics are essential for mitochondrial morphology and function. Here, we establish a novel mechanistic linker among glutamate excitotoxicity, mitochondrial dynamics, and mitochondrial dysfunction in spinal cord motor neurons. Ca2+-dependent activation of the cysteine protease calpain in response to glutamate results in the degradation of a key mitochondrial outer membrane fusion regulator, mitofusin 2 (MFN2), and leads to MFN2-mediated mitochondrial fragmentation preceding glutamate-induced neuronal death. MFN2 deficiency impairs mitochondrial function, induces motor neuronal death, and renders motor neurons vulnerable to glutamate excitotoxicity. Conversely, MFN2 overexpression blocks glutamate-induced mitochondrial fragmentation, mitochondrial dysfunction, and/or neuronal death in spinal cord motor neurons both in vitro and in mice. The inhibition of calpain activation also alleviates glutamate-induced excitotoxicity of mitochondria and neurons. Overall, these results suggest that glutamate excitotoxicity causes mitochondrial dysfunction by impairing mitochondrial dynamics via calpain-mediated MFN2 degradation in motor neurons and thus present a molecular mechanism coupling glutamate excitotoxicity and mitochondrial dysfunction.  相似文献   
969.
M Streuli  N X Krueger  T Thai  M Tang    H Saito 《The EMBO journal》1990,9(8):2399-2407
Protein tyrosine phosphorylation is regulated by both protein tyrosine kinases and protein tyrosine phosphatases (PTPases). Recently, the structures of a family of PTPases have been described. In order to study the structure-function relationships of receptor-linked PTPases, we analyzed the effects of deletion and point mutations within the cytoplasmic region of the receptor-linked PTPases, LCA and LAR. We show that the first of the two domains has enzyme activity by itself, and that one cysteine residue in the first domain of both LCA and LAR is absolutely required for activity. The second PTPase like domains do not have detectable catalytic activity using a variety of substrates, but sequences within the second domains influence substrate specificity. The functional significance of a stretch of 10 highly conserved amino acid residues surrounding the critical cysteine residue located in the first domain of LAR was assessed. At most positions, any substitution severely reduced enzyme activity, while missense mutations at the other positions tested could be tolerated to varying degrees depending on the amino acid substitution. It is suggested that this stretch of amino acids may be part of the catalytic center of PTPases.  相似文献   
970.
Meta分析及其在生态学上的应用   总被引:23,自引:2,他引:23  
1Meta分析的概念和它的发展应用Meta分析(Meta-Analysis)是一种定量综合研究结果的方法.这种方法的思想起源于本世纪30年代,60年代用于教育、心理等社会科学领域,1976年由Glas命名为术语“Meta-Analysis”[1]。G...  相似文献   
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