Effects of Selenium on Lipid Peroxidation and Oxidizing Ability of Rice Roots under Ferrous Stress

Water culture experiment was conducted to study the effects of selenium(Se) on glutathione peroxidase(GSH-Px) activity,reduced glutathione(GSH) concentration and the accumulation of malonaldehyde(MDA),the product of lipid peroxidation in rice seedling,as well as the effect of se on oxidizing ability of roots under ferrous stress.Results showed that appropriate amount of se significantly increased GSH-Px activity in rice leaves,F=5.5 *,enhanced the amount of GSH and oxidizing ability of roots and reduced the concentration of MDA,F=4.9 *.Compared with Se0+Fe treatment,Se treatments increased the dry matter weight of rice seedling from 10.06% to 10.43%,F=4.09 *.

Effect of Biodiesel on Oxidation Stability, Detergency and Antiwear Ability of Diesel Oil

Different contents of biodiesel and petrodiesel were incorporated into diesel engine oils. The oxidative stability, detergency and antiwear performance of the formulated diesel oils were evaluated. The results indicated that, compared with petrodiesel, biodiesel was more liable to promote oxidation degradation of diesel oils, leading to worse oxidative stability, detergency and antiwear ability of the oils.

Water oxidation catalytic ability of polypyridine complex containing a μ-OH, μ-O_2 dicobalt(iii) core

Two polypyridine complexes containingμ‐OH,μ‐O2dicobalt(III)cores,[(TPA)CoIII(μ‐OH)(μ‐O2)CoIII(TPA)](ClO4)3and[(BPMEN)CoIII(μ‐OH)(μ‐O2)CoIII(BPMEN)](ClO4)3(TPA=tris(2‐pyridylmethyl)amine,BPMEN=N,N′‐dimethyl‐N,N′‐bis(pyridin‐2‐ylmethyl)ethane‐1,2‐diamine),have previously been reported as inactive in the light‐driven water oxidation reaction(ACS Catal.,2016,6,5062?5068).Herein,another dicobalt(III)compound,μ‐OH,μ‐O2‐[{(enN4)2Co2}](ClO4)3(enN4=1,6‐bis(2‐pyridyl‐2,5‐diazaocta‐2,6‐diene),with a similar core structure was synthesized,characterized,and applied to the light‐driven water oxidation reaction.Collective experiments showed that the complex itself was also inactive in the light‐driven water oxidation,and that the activity observed originated from Co(II)impurities.This research establishes that complexes possessing aμ‐OH,μ‐O2dicobalt(III)core structure are not appropriate choices for true molecular catalysts ofwater oxidation.

Influence of a Protective Coating Slurry on Enhancing the Descaling Ability and Oxidation Resistance of 9% Nickel Steel

A kind of ceramic slurry was prepared and sprayed onto the surface of 9Ni steel at room temperature. The coating layer will not only reduce the depth of the formed Ni-enriched entanglement at high temperature but also have an excellent ability to resist oxidation of the 9Ni steel. Compared to bare specimen, the depths of the entanglement of the coated 9Ni specimen could be successfully reduced by 74.1% and the oxidation loss be decreased by 62.3% by heating at 1 250 ℃ for 60 min. In addition, the coated specimen indicates no trace of oxide pegs. It proves that the coating has outstanding improvement to internal oxidation resistance. Some characterization methods such as metalloscopy, XRD, XPS, SEM and EDX have been used to reveal a possible protective mechanism. The result shows that the coating layer reacts with the iron oxide to form Mg Fe2O4 on the surface of the coated specimen, which could provide a smaller diffusion coefficient rate of Fe ion. The coating with a low cost and easy implementation is promisingly applicable in the slab-reheating process of the 9Ni steel.

Effect of Selenium on Root Oxidizing Ability and Yield of Rice under Ferrous Stress

To study the effects of selenium on root oxidizing ability and yield of rice under ferrous stress, a pot culture experiment was conducted, the activity of glutathione peroxidase (GSH-Px) and the concentration of malonaldelyde (MDA) were determined. The root oxidizing ability and yield characters of rice were examined. Results showed that appropriate amount of Se enhanced the activity of glutathione peroxidase and the oxidizing ability of rice roots significantly, reduced the concentration of MDA, increased 1000-grain weight of rice, F = 26.96**, decreased empty and blighted grain rate, increased the rice yield, F = 11.53**, and enhanced the rice resistance under ferrous stress.

Effect of Roasting Conditions of Rich Cerium Rare Earth Carbonate on Crystallite Morphology and Polishing Ability of Ceria-Based Rare Earth Oxide

The granule shape and crystal structure of the the ceria-based rare earth oxide which were roasted at 600～1050 ℃ for 2～6 h and then cooled in furnace, cooled out of furnace or cooled in water were studied by means of XRD and SEM. The results revealed that the rich cerium rare earth carbonate could be changed into the rare earth oxide which was a kind of sandwich made of globose granule whose diameter was between 0.5～3.0 μm after being roasted in 900 ℃ for 2 h. This kind of crystal lattice in rare earth oxide belonged to face-centered cubic lattice and its space between crystal surface {111} and {200} (viz. L111 and L200) would enlarge as the roasting temperature increasing. With increasing roasting temperature, L111 would rise straightly upward, and L200 would rise straightly upward when roasting time was 2～4 h but changed little when roasting time was 4～6 h. The glass-polishing experiments found that the polishing ability of the ceria-based rare earth oxide was the best as L111 was 43～53 nm and the L200 was 43～56 nm.

Glass-forming Ability and Chemical Stability of Magneto-optical Glass Heavily Doped with Rare Earth Oxide

The glass-forming region of B2O3-Al2O3-SiO2 （BAS） glass heavily doped with rare earth oxides was investigated by an effective method, and the chemical stability was investigated by powder method. Influences of rare earth oxides on the glass-forming ability and the chemical stability of the BAS glass were also discussed. The experimental results show that the BAS glass-forming region expands firstly with the increase of the Tb2O3 content up to 30mol% and then shrinks. The acid-resistant capacity of the BAS glass doped with rare earth oxides is the lowest, the water-resistant capacity is secondary, and the alkali-resistant capacity is the best. Besides, the glass chemical stability can be improved by doping appropriate amount of rare earth oxides. Moreover, the stronger the ionic polarization ability of the rare earth ions is, the better the chemical stability of the BAS glass will be.

Changes of learning and memory ability associated with neuronal nitric oxide synthase in brain tissues of rats with acute alcoholism

BACKGROUD： Ethanol can influence neural development and the ability of leaming and memory, but its mechanism of the neural toxicity is not clear till now. Endogenous nitric oxide （NO） as a gaseous messenger is proved to play an important role in the formation of synaptic plasticity, transference of neuronal information and the neural development, but excessive nitro oxide can result in neurotoxicity. OBJECTIVE ： To observe the effects of acute alcoholism on the learning and memory ability and the content of neuronal nitric oxide synthase （nNOS） in brain tissue of rats. DESIGN ： A randomized controlled animal experiment. SETTING ： Department of Physiology, Xinxiang Medical College MATERIALS： Eighteen male clean-degree SD rats of 18-22 weeks were raised adaptively for 2 days, and then randomly divided into control group （n = 8） and experimental group （n = 10）. The nNOS immunohistochemical reagent was provided by Beijing Zhongshan Golden Bridge Biotechnology Co.,Ltd. Y-maze was produced by Suixi Zhenghua Apparatus Plant. METHODS ： The experiment was carded out in the laboratory of the Department of Physiology, Xinxiang Medical College from June to October in 2005. ① Rats in the experimental group were intraperitoneally injected with ethanol （2.5 g/kg） which was dissolved in normal saline （20%）. The loss of righting reflex and ataxia within 5 minutes indicated the successful model. Whereas rats in the control group were given saline of the same volume. ② Examinations of learning and memory ability： The Y-maze tests for learning and memory ability were performed at 6 hours after the models establishment. The rats were put into the Y-maze separately. The test was performed in a quiet and dark room. There was a lamp at the end of each of three pathways in Y-maze and the base of maze had electric net. All the lamps of the three pathways were turned on for 3 minutes and then turned off. One lamp was turned on randomly, and the other two delayed automatically. In 5 seconds after alternation, pulsating electric current presented in the base of unsafe area to stimulate rat＇s feet to run to the safe area. The lighting lasted for 15 seconds as one test. Running from unsafe area to safe area at one time in 10 seconds was justified as successful. Such test was repeated for 10 times for each rat and the successful frequency was recorded. The qualified standard of maze test was that the rat ardved in the safe area g times during 10 experiments. The number of trainings for the qualified standard was used to represent the result of spatial learning. ③ Determination of the content of nNOS in brain tissue： After the Y-maze test, the rats were anaesthetized, and blood was let from the incision on right auricle, transcardially perfused via the left ventricle with about 200 mL saline, then fixed by perfusion of 40 g/L paraformaldehyde. Hippocampal CA1 region, corpus striatum and cerebellum were taken to prepare serial freezing coronal sections. The nNOS contents in the brain regions were determined with the immunohistochemical methods to reflect the changes of nitdc oxide in brain tissue. MAIN OUTCOME MEASURES ： The changes of learning and memory ability and the changes of the nNOS contents in the brain tissue of rats with acute alcoholism were observed. RESULTS ： One rat in the experimental group was excluded due to its slow reaction to electdc stimulation in the Y-maze test, and the other 17 rats were involved in the analysis of results. ① The training times to reach qualifying standards of Y-maze in the expedmental group was more than that in the control group [（34.33 ±13.04）, （27.50±8.79） times, P〈 0.05]. ② Forms and numbers of nNOS positive neurons in brain tissue： It could be observed under light microscope that in the hippocampal CA1 region, there were fewer nNOS positive neurons, which were lightly stained, and the processes were not clear enough; But the numbers of the positive neurons which were deeply stained as huffy were obviously increased in the experimental group, the cell body and cyloplasm of process were evenly stained, but the nucleus was not stained. The nNOS positive neurons in corpus stdatum had similar forms and size in the experimental group and control group. The form of the nNOS positive neurons in cerebellum were similar between the two groups. The numbers of nNOS positive neurons in hippocampal CA1 region and corpus striatum in the expedmental group [（18.22±7.47）, （11.38±5.00） cells/high power field] were obviously higher than those in the control group [（10.15±4.24）, （6.15±3.69） cells/high power field. The number of nNOS positive neurons in cerebellum had no significant difference between the two groups [（49.56±18.84）, （44.43±15.42） cells/high power field, P〉 0.05]. CONCLUSION ： Acute alcoholism may impair learning and memory ability, and nitric oxide may be involved in mediating the neurotoxic role of ethanol.

Mussel-inspired Methacrylic Gelatin-dopamine/Ag Nanoparticles/Graphene Oxide Hydrogels with Improved Adhesive and Antibacterial Properties for Applications as Wound Dressings

A novel strategy was developed to prepare the methacrylic gelatin-dopamine(GelMA-DA)/Ag nanoparticles(NPs)/graphene oxide(GO) composite hydrogels with good biocompatibility,mechanical properties,and antibacterial activity.Mussel-inspired DA was utilized to modify the GelMA molecules,which imparts good adhesive performance to the hydrogels.GO,interfacial enhancer,not only improves mechanical properties of the hydrogels,but also provides anchor sites for loading Ag NPs through numerous oxygencontaining functional groups on the surface.The experimental results show that the GelMA/Ag NPs/GO hydrogels have good biocompatibility,and exhibit a swelling rate of 202±16%,the lap shear strength of 147±17 kPa,and compressive modulus of 136±53 kPa,in the case of the Ag NPs/GO content of 2 mg/mL.Antibacterial activity of the hydrogels against both gram-negative and gram-positive bacteria is dependent on the Ag NPs/GO content derived from the release of Ag^(+).Furthermore,the GelMA/Ag NPs/GO hydrogels possess good adhesive ability,which is resistant to highly twisted state when stuck on the surface of pigskin.These results demonstrate promising potential of the GelMA-DA/Ag NPs/GO hydrogels as wound dressings for biomedical applications in clinical and emergent treatment.

Oxidizing Capability of Refining Slags Containing BaO

According to the coexistence theory of slag structure melts, the oxidizing capability of the refining slag CaO-MgO-FeO- A12O3SiO2 is studied and the relationship between the mass action concentration of FeO (NFeO) and the activity of FetO (αFetO) for this slag is found to be as NFeo=0.656 1 αFetO. Furthermore, the calculating model of oxidizing capability of the refining slag BaO-CaO-MgO- FeOA12O3-SiO2 is established. A satisfactory result is obtained when using the above oxidizing capability relationship to calculate the desulphurizing capability of such refining BaO-slags.

Salt-induced difference between Glycine cyrtoloba and G.max in anti-oxidative ability and K^+ vs. Na^+ selective accumulation

To characterize differences in soybean resistance to salt stress, two soybean species, the wild salt-tolerant soybean Glycine cyrtoloba(serial number ACC547) and the cultivated salt-sensitive soybean G. max(cv. Melrose) were treated with 0, 50, 100, or 150 mmol L-1Na Cl for 5 days. A series of physiological parameters were determined in both shoots and roots, including content of chlorophyll(Chl) and malondialdehyde(MDA); electrolyte leakage(EL); hydrogen peroxide(H2O2) concentration; superoxide oxygen radical(O2-)production rate; activities of several enzymes including superoxide dismutase(SOD),catalase(CAT), and peroxidase(POD); and selective ion(Na+and K+) accumulation. Our results showed that the relative salt tolerance of ACC547 was associated with lower loss of Chl content; lower MDA content, EL, H2O2 concentration, and O2-production rate in both shoots and roots; higher POD activity caused by new isoforms in roots; and higher K+concentration and K+/Na+ratio in shoots. These results suggested that relative lower membrane injury, efficient K+vs. Na+selective accumulation, and newly induced POD isoenzymes are mechanisms of salt tolerance in soybean.

Law of gas production during coal heating oxidation

Coal spontaneous combustion is a great threat to mine safety,and gas is the key index to describe coal spontaneous combustion.Taking the coal samples of different kinds of coal as research object,the temperature programmed oxidation experiment was carried out,and the gases produced by coal samples at different temperatures were collected and analyzed by gas chromatography.This research studied the variation characteristics of gas species and gas concentrations in different coal samples during heating oxidation.The experimental results show that different coal samples produce different kinds of gases in the process of heating and oxidation.The order of gas production is CO,C2H6,C2H4,C3H8,and the relationship between gas production and temperature is approximately exponential.With the increase of coal metamorphic degree,the turning point temperature of sharp rise in coal sample gas production rate become higher,the oxidation ability of coal sample decreases,and the quantity of gas production decreases during the same time period.

Effects of melatonin on learning abilities, cholinergic fibers and nitric oxide synthase expression in rat cerebral cortex

BACKGROUND: Melatonin is a kind of hormones derived from pineal gland. Recent researches demonstrate that melatonin is characterized by anti-oxidation, anti-senility and destroying free radicals. While, effect and pathogenesis of pineal gland on learning ability should be further studied. OBJECTIVE: To investigate the effects of pinealectomy on learning abiliy, distribution of cholinesterase and expression of neuronal nitric oxide synthase (nNOS) in cerebral cortex of rats and probe into the effect of melatonin on learning ability, central cholinergic system and nNOS expression. DESIGN: Randomized grouping design and animal study. SETTING: Department of Neurology, the 187 Hospital of Chinese PLA. MATERIALS: A total of 12 male SD rats, of normal learning ability testing with Y-tape maze, of clean grade, weighing 190-210 g, aged 6 weeks, were selected in this study. METHODS: The experiment was carried out in the Department of Neurology, Zhujiang Hospital from July 1997 to June 2000. All SD rats were divided into experimental group (n =6, pinealectomy) and control group (n =6, sham operation). Seven days later, rats in both two groups were continuously fed for 33 days. ① Learning ability test: The learning ability of rats was tested by trisection Y-type maze and figured as attempting times. ② Expression of acetylcholinesterase (AchE) was detected by enzyme histochemistry and nNOS was measured by SABC method. ③ Quantitative analysis of AchE fibers: AchE fibers density in unit area (surface density) was surveyed with Leica Diaplan microscope and Leica Quantimet 500+ image analytic apparatus and quantitative parameter was set up for AchE fibers covering density (μm2) per 374 693.656 μm2, moreover, the AchE fibers density was measured in Ⅱ-Ⅳ layers of motor and somatosensory cortex (showing three layers per field of vision at one time), in radiative, lacunaria and molecular layers of CA1, CA2 and CA3 areas, and in lamina multiforms of dentate gyrus. Three tissue slices were picked up randomly in the same part of each rat, together six tissue slices for nNOS expression and four near view (× 400) were selected in the parts of right neocortex, medial septal nucleus-diagonal band nucleus (SM-DB), corpus striatus and hippocampus to count nNOS-positive cells. MAIN OUTCOME MEASURES: Learning ability; distribution and quantitative analysis of AchE fibers; expression of nNOS in various cerebral areas. RESULTS: The twelve rats were all involved in the final analysis. ① Learning ability test: The learning abilities before operation in the experimental group [(14.67±4.97) times] were consistent with those in the control group [(14.33±4.32) times, P > 0.05], the learning abilities in the experimental group at 40 days after pinealectomy [(28.67±2.42) times] were obviously more than those before pinealectomy and those in the control group after operation [(13.83±8.33) times, P < 0.01]. ② Results of AchE-positive fibers density in cerebral cortex of rats: The AChE-positive fibers densities in motor and somatosensory cortex, CA1, CA2 and CA3 areas of hippocampus and in lamina multiforms of dentate gyrus in the experimental group were obviously lower than those in the control group [experimental group: (15 244±1 339), (14 764±1 391), (12 991±970), (15 077±1 020), (19 546±1 489), (19 337±1 378) μm2; control group: (21 001±1 021), (17 930±2 225), (17 260±1 342), (18 911±1 048), (24 108±1 671), (22 917±1 909) μm2, P < 0.01]. ③ Expression of nNOS in various cerebral areas: nNOS-positive cells in cerebral cortex of rats of the experimental group were more, furthermore the ones in somatosensory cortex were slightly more in motor cortex and the number (5.90±0.68) was more than that in the control group (3.68±0.39,P < 0.05). The nNOS-positive cells in SM-DB (16.21±2.03) were markedly more than those in the control group (9.32±1.05,P < 0.01). The nNOS-positive cells in hippocampus (4.27±0.75) and in corpus striatus (9.35±2.58) were not different with those in the control group (3.94±0.53, 8.96±2.31, P > 0.05). CONCLUSION: Decrease of melatonin due to pinealectomy of rats can result in learning disorder, which may be related to trauma of cholinergic neuron in cerebral cortex which were caused by nitric oxide neurotoxicity arose from the overexpression of nNOS in cerebral neocortex and SM-DB.

藏药二十五味珊瑚丸对帕金森病模型大鼠运动能力及氧化应激水平的影响

目的:探讨藏药二十五味珊瑚丸对帕金森病(parkinson disease,PD)模型大鼠运动能力及氧化应激水平的影响。方法:将24只SD大鼠随机分为藏药二十五味珊瑚丸组(180 mg·kg^(-1))、模型组及正常组,每组各8只。除正常组外,其余大鼠采用纹状体单点注射6-羟基多巴胺(6-hydrodopamine,6-OHDA)法制备PD模型。造模成功后,各组大鼠每天灌胃给药1次,连续4周,模型组和正常组大鼠给予等体积生理盐水。给药第1天、第7天、第14天、第21天、第28天分别称量动物体质量;给药4周后,采用旋转实验及旷场实验观察大鼠行为学变化;ELISA法测定大鼠纹状体丙二醛(malondialdehyde,MDA)、谷胱甘肽(glutathione,GSH)及超氧化物歧化酶(superoxide dismutase,SOD)水平。结果:各组大鼠体质量比较,差异无统计学意义(P>0.05);与正常组比较,模型组大鼠旋转频率显著升高(P<0.001);旷场实验平均速度显著降低(P<0.05),运动距离显著缩短(P<0.01),静止时间显著延长(P<0.05);纹状体内MDA水平显著升高(P<0.05),SOD及GSH水平显著降低(P<0.05)。与模型组比较,二十五味珊瑚丸组大鼠旋转频率显著降低(P<0.05);旷场实验平均速度显著升高(P<0.05),运动距离显著延长(P<0.05),静止时间显著缩短(P<0.05);纹状体MDA水平显著降低(P<0.05),GSH及SOD水平显著升高(P<0.05)。结论:二十五味珊瑚丸可显著改善PD大鼠运动能力,调节脑中氧化应激反应。

14种喀斯特地区植物药提取物的体外抗氧化活性比较

目的 对14种喀斯特地区特色植物药抗氧化活性进行筛选,为氧化应激诱导的相关疾病药物干预提供基础数据。方法 构建抗氧化测定体系(清除羟自由基能力的测定、清除2,2-联苯基-1-苦基肼基(DPPH)自由基能力的测定、铁氰化钾还原能力的测定及抑制脂质过氧化能力测定),以维生素C作为阳性对照,检测14植物药醇提取物的体外抗氧化活性,采用隶属函数分析法进行结果的综合评价及排序。结果 植物药对羟自由基的清除能力强弱为仙桃草、瓜子金>凉粉柴>天冬>锦茵陈>维生素C>其余药物;植物药对DPPH自由基的清除能力强弱为维生素C>锁阳>吴茱萸>响铃草>皂角>薏苡仁>仙桃草>其余药物;植物药还原能力的强弱为吴茱萸、仙桃草、锁阳、锦茵陈和菟丝子的还原能力比阳性对照组强,响铃草和皂角的还原能力与对照组相近,其余药物弱于对照组;植物药抑制脂质过氧化能力强弱为凉粉柴>仙桃草>响铃草>吴茱萸>菟丝子>玉竹>瓜子金>天冬>维生素C>其余药物;最后通过隶属函数分析显示,14种植物药的抗氧化能力为仙桃草>吴茱萸>维生素C>凉粉柴>响铃草>锁阳>天冬>皂角>瓜子金>薏苡仁>菟丝子>锦茵陈>黄精>一朵云>玉竹。结论 所检测的植物药中,仙桃草可能作为潜在的抗氧化应激候选药物;采用抗氧化评价体系结合隶属函数分析,更加科学可靠地评价了药物的抗氧化能力。

沙棘叶多糖对血管性痴呆大鼠学习记忆能力的改善作用

通过建立血管性痴呆大鼠模型,研究沙棘叶多糖对学习记忆能力的影响。设置假手术组、模型组、低、高剂量沙棘叶多糖组(100、200 mg/kg)及尼莫地平组(6.25 mg/kg),干预治疗28 d后检测相关指标变化。结果显示,与模型组比较,低、高剂量沙棘叶多糖组逃避潜伏期降低了24.35%、32.90%(P<0.01),目标象限停留时间增加了24.35%、51.30%(P<0.01),平台穿越次数提升了29.33%、60.58%(P<0.01),且海马组织病理形态减轻;海马组织神经元细胞凋亡率及B淋巴细胞瘤-2(Bcl-2)相关X蛋白(Bax)、半胱氨酸蛋白酶-3(Caspase-3)mRNA表达减少(P<0.01),Bcl-2mRNA表达增加(P<0.05,P<0.01);海马组织谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性及核因子E2相关因子2(Nrf2)、血红素氧合酶-1(HO-1)蛋白表达增加(P<0.05,P<0.01),丙二醛(MDA)含量降低(P<0.01)。以上结果表明,沙棘叶多糖可以通过抗凋亡及抑制氧化应激发挥改善血管性痴呆大鼠学习记忆能力作用,提示其在预防和治疗血管性痴呆方面有一定的应用前景。

Superior synergistic oxidation resistance of medium-entropy carbide ceramic powders rather than multi-phase carbide ceramic powders

To date,some questions about medium-entropy carbide ceramics and the corresponding multi-phase carbide ceramics with the same cations and proportions remain unclear.Regarding oxidation behavior,do both have synergistic oxidation abilities and what role does entropy stabilization play in medium-entropy carbides?In this work,the oxidation behaviors of HfC-ZrC-TiC multi-phase carbide(HZT-MPC)and(Hf_(1/3)Zr_(1/3)Ti_(1/3))C medium-entropy carbide(HZT-MEC)powders were investigated.After thermogravimetry(TG)oxidation,the TG curve of HZT-MPC had a bimodal distribution.The"preferential oxidation"of HfC/ZrC occurred within HZT-MPC,followed by the formation of multi-phase oxides(HfO_(2),ZrO_(2),and TiO_(2)).The uneven compositional distribution slowed their solid solution reactions to form Ti-doped(Hf,Zr)O_(2) and(Hf,Zr)TiO_(4).The TG curve of HZT-MEC had a single peak.A uniform compositional distribution at the atomic scale promoted the rapid interdiffusion of oxides,forming Ti-doped(Hf,Zr)O_(2) and(Hf,Zr)TiO_(4) without ZrO_(2),HfO_(2),and TiO_(2) after TG oxidation.Additionally,HZT-MEC had a higher onset oxidation temperature(To;470℃)than did HZT-MPC(430℃),and the TG single peak of HZT-MEC was between the TG bimodal peaks of HZT-MPC.Therefore,HZT-MEC showed superior oxidation resistance compared to HZT-MPC,which was attributed to the entropy stabilization effect of HZT-MEC suppressing the"preferential oxidation"of HfC/ZrC and the"delayed oxidation"of TiC,promoting the synergistic oxidation ability of multiple principal elements.

藤茶提取液对电离辐射损伤造血系统的防护作用研究

采用1,1-二苯基-2-苦基肼自由基(DPPH)和总抗氧化能力检测(ABTS)两种方法体外检测藤茶提取液的抗氧化能力;然后进行生存率实验,将40只雄性C57BL/6J小鼠随机分为照射组、照射+藤茶提取液低、中、高剂量组(0.8 g/kg、1.6 g/kg、2.4 g/kg),所有小鼠均进行致死剂量7.2 Gy照射,检测藤茶提取液对照射后小鼠的生存影响;随后在电离辐射损伤造血系统实验中将50只雄性C57BL/6J小鼠随机分为5组:空白对照组、照射组、照射+藤茶提取液低、中、高剂量组,经4 Gy全身照射后,观察藤茶提取液对电离辐射后小鼠脏器指数、造血指标等的影响,并测定肝脏中总超氧化物歧化酶(T-SOD)和谷胱甘肽(GSH)的变化。实验结果表明,藤茶提取液对DPPH自由基清除率为74.35%,对ABTS自由基清除率为93.14%,能够提高7.2 Gy照射下小鼠的生存率(照射组生存率为30%,低剂量组生存率为100%,中剂量组生存率为90%,高剂量组生存率为90%),并改善4 Gy全身照射所导致造血系统损伤小鼠的脏器指数和造血指标,还能升高照射小鼠肝脏中T-SOD活力以及GSH的含量。藤茶提取液具有较强的抗氧化能力,能提高电离辐射后小鼠的生存率,并改善其引起的造血系统损伤,有望成为电离辐射导致造血系统损伤的中药防护剂。

十全大补汤通过调节突触功能对阿尔兹海默病小鼠认知损伤的改善作用

目的探究十全大补汤对阿尔兹海默病(AD)小鼠突触功能及认知损伤的改善作用。方法60只小鼠随机分为对照组、模型组、美金刚组(5 mg/kg)和十全大补汤高、中、低剂量组(6.24、3.12、1.56 g/kg),每组10只,除对照组外,其余各组小鼠腹腔注射D-半乳糖并灌胃AlCl370 d建立AD模型,造模第29天开始,各组灌胃给予相应剂量药物42 d。通过Morris水迷宫实验和条件恐惧实验检测空间学习记忆及联想记忆,HE染色观察海马神经元形态改变情况,试剂盒检测血清SOD活性、MDA水平及海马组织SOD、AChE活性,MDA、ACh、TNF-α、IL-1β水平,Western blot法检测海马组织PSD-95、Shank3、NR1、NR2A、NR2B、AMPK、p-AMPK蛋白表达。结果与模型组比较,十全大补汤高剂量组小鼠空间学习记忆能力与联想记忆提升(P<0.05,P<0.01),海马神经元病理损伤减轻,氧化应激及炎症水平下降(P<0.05,P<0.01),胆碱能传递增强(P<0.05,P<0.01),海马组织PSD-95、Shank3、NR1、NR2A、NR2B、p-AMPK蛋白表达升高(P<0.05,P<0.01)。结论十全大补汤可改善AD小鼠认知损伤,其机制可能与激活AMPK,恢复突触功能有关。

云南主栽核桃和油橄榄16个品种油脂体外抗氧化活性研究

分析云南主栽核桃和油橄榄品种的体外抗氧化活性,为生产核桃和油橄榄的高端复配油提供理论依据。采用试剂盒法对液压榨取核桃油及西班牙橄榄油分析检测系统制备橄榄油脂的总抗氧化能力、羟自由基清除能力、ABTS自由基清除能力、DPPH自由基清除能力以及超氧阴离子清除能力进行分析。结果显示:8个主栽核桃品种的核桃油总抗氧化能力在1.70~10.18(μmol Trolox)·g^(-1)之间,ABTS自由基清除能力在264.04~2224.39(μg Trolox)·g^(-1)之间,DPPH自由基清除能力在388.62~2892.73(μg Trolox)·g^(-1)之间,羟自由基清除率在52.88%~77.77%之间,超氧阴离子清除率在16.25%~39.08%之间,总抗氧化能力、ABTS自由基清除能力及DPPH自由基清除能力品种间差异较大;8个品种油橄榄果油总抗氧化能力在0.73~4.20(μmol Trolox)·g^(-1)之间,ABTS自由基清除能力在153.57~610.91(μg Trolox)·g^(-1)之间,DPPH自由基清除能力在79.20~878.67(μg Trolox)·g^(-1)之间,羟自由基清除率在57.41%~62.83%之间,超氧阴离子清除率在16.69%~38.36%之间。结果表明:云南主栽8个核桃品种抗氧化性能最好品种为‘大姚三台核桃’,其次为‘细香核桃’,抗氧化性能与总酚含量呈显著正相关;油橄榄油脂体外抗氧化活性低于核桃油,其中抗氧化性能最好品种为‘金叶佛樨榄’,其次为‘科拉蒂’,抗氧化性能与总酚含量也呈显著正相关。