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1.
HUA Cong WANG Xuanzhong LIANG Shipeng LI Chen CHEN Xi PIAO Meihua WANG Zhenchuan GE Pengfei LUO Tianfei 《高等学校化学研究》2022,38(4):1089-1096
Ferroptosis triggered by hemin is regarded as a primary factor accounting for neuronal death secondary to intracerebral hemorrhage. Thus, compounds with inhibitory effect on hemin-induced ferroptosis might be potential medicines to prevent neuronal death caused by intracerebral hemorrhage. Herein, we investigate whether maltol could alleviate hemin-induced SH-SY5Y cell ferroptosis and its potential mechanisms. It is found that maltol effectively prevents hemin-induced SH-SY5Y cell ferroptosis via three pathways. The first one is inhibiting intracellular iron increase via preventing upregulation of transferrin receptor, the second one is alleviating lipid peroxidation via attenuating H2O2 generation by NOX4 and promoting H2O2 clearance by catalase, and the third one is to reduce peroxidized lipids via maintaining GPX4/GSH pathway. Therefore, maltol is a novel agent preventing hemin-induced SH-SY5Y cell ferroptosis. 相似文献
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Understanding and control of the surface properties such as molecular orientations are of great importance in numerous applications of ionic liquids. However, there remain discrepancies among the previous experimental and theoretical studies on the surface orientation and structures of room temperature ionic liquids(RTIL) systems. In this article, the orientation of 1-butyl-3-methylimidazolium([bmin]) cation at the air/liquid interface of a characteristic RTIL, 1-butyl-3-methylimidazolium hexafluorophosphate([bmim][PF6]), was investigated by the sum frequency generation vibrational spectroscopy(SFG-VS). Detailed polarization and experimental configuration analyses of the SFG-VS spectra showed the possibility of a small spectral splitting in the CH3 symmetric stretching region, which can be further attributed to the probable existence of multiple orientations for the interfacial [bmim] cations. In addition, the(N)–CH3 vibrations were absent, ruling out the prediction by several recent molecular dynamics simulations which state that portions of the [bmim] cations orient with a standing-up(N)–CH3 group at the ionic liquid surface. Hence, new realistic theoretical models have to be developed to reflect the complex nature of the ionic liquid surface. 相似文献
4.
The chemical equilibrium and reaction kinetic behavior in the synthesis of polyoxymethylene dimethyl ethers(DMMn) were investigated over sulfated titania in order to reveal the decisive factor controlling the reaction. The results showed that the molar ratio of adjacent DMMn products in equilibrium solution had the same value, which depended absolutely on the reaction temperature. Meanwhile, the reactions had the same DMMn products distributions under varied reaction conditions. The equilibrium constants of the related step-wise reactions for DMMn formation were equal, which were calculated based on the bulk compositions of the reaction solution. And thus, the selectivity to DMMn was mainly controlled by the chemical equilibrium, i.e., thermodynamic control. In brief, the present results provide some guidance for future synthesis of DMMn. 相似文献
5.
Peng Zhao Juping Yang Yuming Shang Li Wang Mou Fang Jianlong Wang Xiangming He 《天然气化学杂志》2015,(2):138-144
Surface chemical modification of polyolefin separators for lithium ion batteries is attempted to reduce the thermal shrinkage, which is important for the battery energy density. In this study, we grafted organic/inorganic hybrid crosslinked networks on the separators, simply by grafting polymerization and condensation reaction. The considerable silicon-oxygen crosslinked heat-resistance networks are responsible for the reduced thermal shrinkage. The strong chemical bonds between networks and separators promise enough mechanical support even at high temperature. The shrinkage at 150 C for 30 min in the mechanical direction was 38.6% and 4.6% for the pristine and present graft-modified separators, respectively. Meanwhile, the grafting organic-inorganic hybrid crosslink networks mainly occupied part of void in the internal pores of the separators, so the thicknesses of the graft-modified separators were similar with the pristine one. The half cells prepared with the modified separators exhibited almost identical electrochemical properties to those with the commercial separators, thus proving that, in order to enhance the thermal stability of lithium ion battery, this kind of grafting-modified separators may be a better alternative to conventional silica nanoparticle layers-coated polyolefin separators. 相似文献
6.
Zhen Xi 《中国科学:化学(英文版)》2015,(3):434-435
Redox-based post-translational modification of protein thiols has become an attractive strategy in cellular homeostasis and cell signaling.Due to the reductive end of the redox buffer network,the vicinal dithiol-containing proteins(VDPs)maintains an appropriate oxidation-reduction state of proteins through the reversible transformation from vicinal dithiols to disulfide,which is responsible for a variety of 相似文献
7.
Lijuan Shen Li Li Sheng Lu Xiaohan Zhang Jie Liu Junlin An Guojun Zhang Bo Wu Fei Wang 《中国颗粒学报》2015,(3):10-15
We conducted measurements of black carbon(BC) aerosol in Jiaxing,China during autumn from September 26 to November 30,2013.We investigated temporal and diurnal variations of BC,and its correlations with meteorological parameters and other major pollutants.Results showed that hourly mass concentrations of BC ranged from 0.2 to 22.0 μg/m3,with an average of 5.1 μg/m3.The diurnai variation of BC exhibited a bimodal distribution,with peaks at 07:00 and 18:00.The morning peak was larger than the evening peak.The mass percentages of BC in PM2.5 and PM10 were 7.1%and 4.8%,respectively.The absorption coefficient of BC was calculated to be 44.4 Mm-1,which accounted for 11.1%of the total aerosol extinction.BC was mainly emitted from local sources in southwestern Jiaxing where BC concentrations were generally greater than 11 μg/m3 during the measurement period.Correlation analysis indicated that the main sources of BC were motor vehicle exhaust,and domestic and industrial combustion. 相似文献
8.
In this paper,we have developed a highly efficient method for the direct preparation of propylene carbonate from propylene and carbon dioxide(CO2) using quaternary ammonium heteropolyphosphatotungstate–quaternary ammonium halide catalytic system with anhydrous hydrogen peroxide as an oxidant through one-pot two-step process.The effects of the amount of tetrabutylammonium bromide(TBAB),the concentration of hydrogen peroxide and other reaction conditions were investigated.The catalyst system gave an optimum propylene oxide yield(91%) at75°C in oxidation step and the highest propylene carbonate yield(99%) at 140°C and 3.0 MPa in cycloaddition step.Based on the results,a reaction mechanism has been proposed. 相似文献
9.
Alzheimer's disease(AD) is one of the most common types of dementia whose hallmarks include neurofibrillary tangles and senile plaques. The latter are mainly composed of amyloid-β proteins(Aβ), and it's suggested that Aβ may be the causative factor in AD pathogenesis. Immunotherapy targeting Aβ for preventing aggregation of Aβ and mildly clearing amyloid plaques has been a hot topic since 1999. Although the first clinical trial of Aβ vaccine, AN-1792, failed in phase II, its results suggested some key points in the design of Aβ vaccines. Avoiding the possible toxic Aβ specific T cell response and inducing a Th2 type cellular immune response may be beneficial for Aβ immunotherapy. Many associations and research groups are working on Aβ vaccine and some progress has been made in recent years. In this review, we have provided a detailed summary of past Aβ vaccines, which have been sorted by the immunogen, and we also discuss some recent progress and future perspectives. 相似文献
10.
Ni-Mg复合催化剂催化裂解CH制氢动力学研究 《燃料化学学报》2017,45(2):249-256
基于定温热重实验,建立了甲烷催化裂解反应动力学模型和催化剂表面积炭失活动力学模型。其中,甲烷催化裂解动力学模型将初始产氢速率视为催化剂未积炭条件下的动力学基础数据;催化剂表面积炭失活动力学则基于甲烷催化裂解速率的降低。实验使用Ni-Mg复合催化剂,分别在535、585、635℃,甲烷分压10~4、2×10~4、3×10~4Pa条件下展开甲烷催化裂解动力学特性研究。结果表明,甲烷催化裂解的反应级数为0.5,活化能为82 k J/mol;Ni-Mg复合催化剂反应失活级数为0.5,催化剂失活活化能为118 k J/mol。实验条件下均制得了多壁碳纳米管。 相似文献