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1.
目的以图像分析法检测海马脑片NMDA损伤后透光性变化,并评价NMDA受体拮抗剂氯胺酮的保护作用。方法大鼠海马脑片在35℃以100μmol/LNMDA处理10min后再灌注60min,诱导透光度改变,并用TTC染色、病理切片加以验证损伤作用。结果NMDA处理大鼠海马脑片后,其透光度先迅速升高,再灌注后降低到正常水平以下;氯胺酮(10、100μmol/L)能够明显抑制透光度的双向改变;TTC染色和病理切片结果与透光法相符。结论本文建立了适宜的海马脑片NMDA损伤模型,透光法可用于评价NMDA损伤及保护药物的作用。 相似文献
2.
钙拮抗剂是作用于可兴奋性细胞膜上钙选择性通道,以调控Ca~(2+)的转运而产生效应。人体的体液和细胞中含极少量的ca~(2+),但对细胞调节极为重要。钙通道以及与之密切相关的钙拮抗剂受体是Ca~(2+)调节过程的重要环节,特别在心肌、平滑肌及腺体分泌中均起关键作用。近年来钙通道的电生理与钙通道结合位点的生化研究均取得了令人瞩目的成就,使钙拮抗剂的作用机理进一步深入,促进了第二代更优秀的钙拮抗剂用于临床。 1.钙通道的电生理近年来发展了斑片电压钳制法(Patch-clamp),能够分析单一钙通道的开关。每个细胞约有1万多个钙通道,每个通道通过的钙量为3—4百万/s。目前认为电压依赖性钙通道可 相似文献
3.
含钒的化合物能够有效地催化H2O2,因此可作为多元Fenton-like催化剂中的有效组份之一,Fe2V4O13中存在Fe(Ⅲ)和V(V)同时和协同活化H2O2的可能性。通过液相合成法制备了Fe2V4O13,并对其对AOⅡ的催化活性进行了研究,研究表明,Fe2V4O13是一种新型高效稳定的多相Fenton-like催化剂。 相似文献
4.
研究表明被测物H2O2的浓度一定时,用电流-曲线,CdS量子点（CdS QDs）修饰电极在光照时与不被光照时电流大小有明显的差异。CdS QDs修饰电极在光照条件下有明显的促进电流增大作用,并且容易受到pH的影响,在pH=4最有利于增大电流。pH=4时被检测物H2O2浓度在3×10^-7到4×10^-6成很好的线性关系,可用于H2O2低浓度的检测。 相似文献
5.
人类2型松弛素(Relaxin-2,RLN2)是一种作用广泛的小分子肽类激素,其抗纤维化作用近年来成为研究热点。除间质性肺疾病外,哮喘、COPD、矽肺等患者的呼吸道、肺泡周围甚至整个肺部在长期的损伤刺激下均会出现成纤维细胞分化、细胞外胶原沉积等纤维化病变。Relaxin-2可以通过激活1型松弛素受体(RXFP1)然后启动直接抗肺纤维化作用抑制成纤维细胞活动和细胞外胶原沉积等病变,也可以通过其他方式(如产生NO、激活糖皮质激素受体等)发挥间接抗肺纤维化作用。本文就松弛素在抗纤维化作用机制及其在抗肺纤维化疾病中的研究进展作一综述。 相似文献
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长期高血糖导致糖尿病患者的氧化应激,引起胰岛β细胞氧化损伤,但核转录因子Nrf2(NF-E2-related factor 2)抵抗胰岛β细胞氧化损伤的作用机制还不清楚.本研究用低浓度葡萄糖(LG,5.6 mmol/L)、LG+H2O2和高浓度葡萄糖(HG,27.6 mmol/L)分别处理小鼠胰岛NIT-1β细胞48 h,检测细胞内活性氧(ROS,reactive oxygen species)生成、胰岛素合成与分泌变化和Nrf2入核表达水平.研究发现,高糖诱导NIT-1β细胞的ROS生成,降低细胞合成与分泌胰岛素的水平,但Nrf2入核表达降低胰岛β细胞氧化应激.结果提示Nrf2入核表达可以抵抗高糖诱导的胰岛β细胞氧化损伤,改善细胞合成与分泌胰岛素的功能. 相似文献
7.
漩流式气锚主要由外管、衬管和内吸管组成,外管有很多与内表面相切向下倾斜的小孔,衬管开有很多径向的孔眼,外管与衬管利用上下接头固定,两者之间形成一个环形空间,内吸管与抽油泵相连并与衬管之间形成一个环形空间.油气混合液经过外管、衬管和内吸管进入抽油泵,整个过程通过了剪切作用、离心力作用和重力作用三级分离,井下油气分离效率高.可用于油气比较高的机抽井. 相似文献
8.
建立了人体细胞间液多相模型,研究了人体细胞间液中Pr(Ⅲ)对Zn(Ⅱ)物种的作用.结果表明,Pr(Ⅲ)能够影响Zn(Ⅱ)的物种分布.Zn(Ⅱ)主要分布于[Zn(HSA)],[Zn(IgG)]和[Zn(Cys)2H]中.Pr(Ⅲ)不能与Zn(Ⅱ)竞争HSA和IgG配体;但是,Pr(Ⅲ)能够与Zn(Ⅱ)竞争磷酸盐和碳酸盐配体,这会引起Zn(Ⅱ)物种的重新分布. 相似文献
9.
目的:观察大明胶囊对2型糖尿病大鼠心功能的作用,并探讨其作用机制。方法:用高脂饮食辅以链脲佐菌素(STZ)建立2型糖尿病大鼠模型,将空腹血糖值大于16.7mmol/L的大鼠随机分6组:糖尿病模型组、大明胶囊大剂量(200mg/kg/d)组、中剂量(100mg/kg/d)组、小剂量(50mg/kg/d)组、对照药罗格列酮(0.8mg/kg/d)组。各给药组连续灌胃给药30天后,HE染色和电镜观察大鼠心肌病理形态学改变;RT-PCR方法测定L型Ca2+通道α1cmRNA和K+通道KV4.2mRNA的表达。结果:大明胶囊可改善2型糖尿病所引起的LVSP、+dp/dtmax下降(P0.05),降低LVEDP、-dp/dt-max水平(P0.05),以中剂量作用最明显;形态学显示大明胶囊中剂量减轻了糖尿病大鼠心肌损伤;中剂量还可缩短注射SNP和PE后血压恢复时间以及增加NTS区c-fos免疫反应阳性细胞个数。结论:a.大明胶囊通过影响KV4.2和α1cmRNA的表达改善Q-T间期和P-R间期的延长;b.大明胶囊可通过改善糖尿病大鼠心肌结构的重塑提高2型糖尿病大鼠心脏收缩和舒张功能。 相似文献
10.
在大气主要污染物SO2、NOX作用下,绿色植物的生理生化指标会受到不同程度的影响。本文选择广西南宁市四个城市功能区——振宁花园、中华北湖路口、广西师范学院、青秀山公园,作为研究地点,采集各功能区共有常见植物红花羊蹄甲(Bauhinia variegate)进行取样分析,分析植物叶片中的叶绿素含量、可溶性蛋白含量、过氧化物酶(POD)活性、超氧化物岐化酶(SOD)活性,对指标进行统计学分析,以此了解植物的生理生化指标与大气污染程度的相关性。研究表明,在四个功能区中,植物叶绿素的含量、可溶性蛋白的含量、POD活性、SOD活性均具有显著性的差异,其测定值分别在8.22mg/l～13.57mg/l,2.31mg/g～3.05mg/g、1.83 u/(g.min)～2.57 u/(g.min)、42.54 u/g～100.87u/g之间;与大气污染的相关系数分别为0.69、0.96、0.99、0.97。通过研究分析表明,红花羊蹄甲中的叶绿素含量、可溶性蛋白含量、过氧化物酶活性、超氧化物岐化酶活性与大气污染的程度具有一定的相关性,可以用于指示大气污染。 相似文献
11.
Yasir Hasan Siddique Tanveer Beg Mohammad Afzal 《Indian journal of clinical biochemistry : IJCB》2009,24(3):294-300
Hydrogen peroxide is one of the reactive oxygen species for cellular injury. It is overproduced during oxidative stress and
is known to damage proteins, nucleic acids and cell membranes. The present study was aimed to study the protective effect
of ascorbic acid against the toxic doses of hydrogen peroxide using lipid peroxidation and cytokinesis blocked micronucleus
assay. Hydrogen peroxide was studied at 50, 100 and 200μM and was found to increase a dose dependent increase in lipid peroxidation
and micronuclei frequency. The treatment of 100 and 200μM of hydrogen peroxide separately along with 20, 40 and 80μM of ascorbic
acid showed a dose dependent decrease in the lipid peroxidation and micronuclei frequency. The results suggest a protective
effect of ascorbic acid against the hydrogen peroxide induced oxidative damage in cultured human peripheral blood lymphocytes. 相似文献
12.
N. S. Nagane J. V. Ganu V. R. Bhagwat M. Subramanium 《Indian journal of clinical biochemistry : IJCB》2004,19(2):173-176
Thermal injury is associated with biochemical changes. The present study was undertaken to investigate relation of oxidative
free radical generation and related biochemical parameters in burn trauma. The specific aim was to compare the levels of serum
lipid peroxide, Ceruloplasmin and Uric Acid in burn patients during treatment with Silver Sulfadiazine Cream and honey therapy.
It is a single blind prospective controlled study involving comparison of biochemical changes after treatment with silver
sulfadiazine and honey treatment in burn injury. In burn trauma, there is excessive activity of free radicals at the site
of injury. This is reflected in elevated blood levels of Lipid peroxide, Ceruloplasmin & Uric Acid. Honey therapy was was
shown to decline the levels of serum Lipid peroxide, while there was mild increments in serum Ceruloplasmin levels whereas
there was no significant effect on serum Uric Acid levels as compared to silver sulfadiazine treatment. Honey therapy seems
to accelerate the process of healing. It has positive effect in reducing oxidative stressful state in burn trauma than the
silver sulfadiazine treatment that results in rapid wound healing. 相似文献
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14.
Mohammad Muzaffar Mir Abdul Rashid Khan Nazir Ahmad Dar Mohammad Salahuddin 《Indian journal of clinical biochemistry : IJCB》2005,20(1):184-192
Alpha-1-proteinase inhibitor activity was studied in presence of resting and activated polymorphonuclear leucocytes. Four
different agonists; phorbol myristic acetate, N-formyl-methionyl-leucyl-phenylalanine, opsonised zymosan and arachidonic acid
decreased the inhibitor activity by 23.3%, 20%, 12% and 16.6^ respectively. The inhibitor activity was protected by using
various free radical scavengers. Catalase and superoxide dismutase both restored activity by about 18%, mannitol by 13% and
sodium azide by 17.3%. The inhibitor activity was also protected significantly by pretreatment of polymorphs with L-Arg, a
precursor of nitric oxide, before activation. L-Arg was also observed to suppress the generation of superoxide and hydroxyl
radical appreciably. The nitric oxide synthase inhibitor, aminoguanidine drastically inhibited the nitrite release and reversed
the protection offered by L-Arg to the inhibitor activity. Our results indicate a multifactorial nature of the inactivation
process, the culprit species being superoxide, hydrogen peroxide, hydroxyl radical and hypohalides. Nitric oxide seems to
scavenge the superoxide radical directly after its formation rather than inhibiting its generation by NADPH oxidase as was
believed earlier. 相似文献
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Xuan Zhao Yu Wang Yunli Da Xinxia Wang Tingting Wang Mingquan Xu Xiaoyun He Wu Zhou Yafei Li Jonathan N Coleman Yanguang Li 《国家科学评论(英文版)》2020,7(8):1360
The two-electron reduction of molecular oxygen represents an effective strategy to enable the green, mild and on-demand synthesis of hydrogen peroxide. Its practical viability, however, hinges on the development of advanced electrocatalysts, preferably composed of non-precious elements, to selectively expedite this reaction, particularly in acidic medium. Our study here introduces 2H-MoTe2 for the first time as the efficient non-precious-metal-based electrocatalyst for the electrochemical production of hydrogen peroxide in acids. We show that exfoliated 2H-MoTe2 nanoflakes have high activity (onset overpotential ∼140 mV and large mass activity of 27 A g−1 at 0.4 V versus reversible hydrogen electrode), great selectivity (H2O2 percentage up to 93%) and decent stability in 0.5 M H2SO4. Theoretical simulations evidence that the high activity and selectivity of 2H-MoTe2 arise from the proper binding energies of HOO* and O* at its zigzag edges that jointly favor the two-electron reduction instead of the four-electron reduction of molecular oxygen. 相似文献
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Cataract is one of the leading causes of visual disability often leading to blindness in the elderly population. One of the
causes is oxidation of proteins present in lens, by hydrogen peroxide (H2O2). In the present study 100 goat lenses were analyzed to determine the protective efficacy of ketoacids, against the oxidative
insult by H2O2. The ketoacids used were (pyruvate, alpha ketoglutarate and oxaloacetate), that are constantly produced endogenously. The
lenses were incubated as control and experimental groups in TC-199 media for 72 hrs. H2O2 concentration of 10mM was used to induce cataract. The biochemical parameters measured were levels of malondialdehyde (MDA),
a lipid peroxidation product and activity of glutathione peroxidase (G-Px), an enzymatic antioxidant. The results showed a
significant increase in the levels of MDA and significant decrease in the activity of G-Px in the cataractous lenses as compared
to control. After addition of ketoacids (pyruvate (10mM), alpha ketoglutarate (20mM) and oxaloacetate (20mM)) separately,
the levels of MDA decreased significantly and the activity of G-Px increased significantly. The results suggest that the ketoacids
can be very promising antioxidants for the treatment of cataract. They may also be useful in treating other disabilities related
to acute and chronic oxidative stress. 相似文献
20.
三株新型发酵产氢菌的分离和不同发酵条件下产氢性能的比较 总被引：1，自引：0，他引：1
氢能是理想的清洁能源,生物制氢技术的研究和开发已成为当前一个研究热点。许多细菌在厌氧条件下发酵复杂的有机化合物,同时产生H2。本文选择了来自同一活性污泥样品的3株有较高产氢能力的发酵细菌,采用生化和电镜技术对其形态学特征进行了观察比较,并进一步比较研究了在不同pH值条件下,它们产氢量、细菌生长量、液相发酵产物组成的变化和差异。获得了三株产氢菌的单位体积培养基最大累积产氢量,提出了纯培养生物制氢的最佳条件,为混合培养生物制氢强化工艺提供参考。 相似文献