BACKGROUND: Around the world more and more people suffer from acute alcoholism. The purpose of this study was to determine hepatic enzymes and oxidation/antioxidation in rats with acute alcoholism. METHODS: Rats were ...BACKGROUND: Around the world more and more people suffer from acute alcoholism. The purpose of this study was to determine hepatic enzymes and oxidation/antioxidation in rats with acute alcoholism. METHODS: Rats were randomly divided into three groups; control, low-dose alcohol, and high-dose alcohol. Each al- cohol group ( n = 12) was intravenously infused with etha- nol at a dose of 0.3 or 0.7 g/kg body weight respectively. The control group (n =11) was intravenously infused with normal saline at a dose of 0.5 g/kg body weight. Blood was collected for detection of hepatic enzymes and index of oxidation/antioxidation. RESULTS: The ratio of AST to ALT was 2.44±0.46, 2.57± 0.60 and 3.03 ±0.46 in the three groups, and the difference was significant between the control and high-dose alcohol groups (P^0.05). No significant changes were observed in the levels of serum alanine aminotransferase (ALT), aspar- tate aminotransferase (AST), total protein (Tp), albumin (Alb), alkaline phosphatase (ALP), cholinesterase (ChE), total bilirubin (TB), C-reactive protein (CRP) and amy- lase. The levels of serum nitric oxide (NO) in the 3 groups were 39.2 ±73.25 mol/L, 42.30 ±4.60 mol/L and 47.86± 4.66 mol/L, and significant difference was seen between the control group and the high-dose alcohol group (P < 0.01). No significant difference was found in the levels of serum superoxide dismutase (SOD), glutathione (GSH), malondiethylaldehyde (MDA), and CRP in the 3 groups. CONCLUSION: The ratio of AST to ALT appears to be a useful index for acute alcohol intoxication. NO is involved in the mechanism of acute alcohol intoxication.展开更多
Traumatic brain injury involves complex pathophysiological mechanisms,among which oxidative stress significantly contributes to the occurrence of secondary injury.In this study,we evaluated hypidone hydrochloride(YL-0...Traumatic brain injury involves complex pathophysiological mechanisms,among which oxidative stress significantly contributes to the occurrence of secondary injury.In this study,we evaluated hypidone hydrochloride(YL-0919),a self-developed antidepressant with selective sigma-1 receptor agonist properties,and its associated mechanisms and targets in traumatic brain injury.Behavioral experiments to assess functional deficits were followed by assessment of neuronal damage through histological analyses and examination of blood-brain barrier permeability and brain edema.Next,we investigated the antioxidative effects of YL-0919 by assessing the levels of traditional markers of oxidative stress in vivo in mice and in vitro in HT22 cells.Finally,the targeted action of YL-0919 was verified by employing a sigma-1 receptor antagonist(BD-1047).Our findings demonstrated that YL-0919 markedly improved deficits in motor function and spatial cognition on day 3 post traumatic brain injury,while also decreasing neuronal mortality and reversing blood-brain barrier disruption and brain edema.Furthermore,YL-0919 effectively combated oxidative stress both in vivo and in vitro.The protective effects of YL-0919 were partially inhibited by BD-1047.These results indicated that YL-0919 relieved impairments in motor and spatial cognition by restraining oxidative stress,a neuroprotective effect that was partially reversed by the sigma-1 receptor antagonist BD-1047.YL-0919 may have potential as a new treatment for traumatic brain injury.展开更多
The oxidation behavior of Ti55 alloy and TiBw/Ti55 composites at temperatures ranging from 960 to 1000℃ was investigated by characterizing the surface and cross-section microstructure of specimens.Results showed that...The oxidation behavior of Ti55 alloy and TiBw/Ti55 composites at temperatures ranging from 960 to 1000℃ was investigated by characterizing the surface and cross-section microstructure of specimens.Results showed that TiBw reinforcement accelerated the occurrence of Ti_(6O)/Ti_(3O) by dissolving oxygen in titanium in the starting oxidation stage,and the Ti_(6O)/Ti_(3O) transformed into TiO_(2) with the progression of oxidation.Meanwhile,TiBw reinforcement promoted the formation of(101)crystal planes to be beneficial to the growth of TiO_(2) twins.The cross-sectional characterization showed that the oxide layer of Ti55 alloy and TiBw/Ti55 composites from outside to inside was TiO_(2)+Al_(2)O_(3),TiO_(2),Ti-Sn compounds,Ti_(6O)/Ti_(3O) in sequence,which was confirmed by calculating the standard Gibbs free energy of the oxide nucleation.The TiBw reinforcement accelerated the occurrence of suboxides Ti_(6O)/Ti_(3O) by dissolving oxygen in titanium,and promoted the formation of(101)crystal planes which were beneficial to the growth of TiO_(2) twins.The optimal addition of TiBw induced the TiO_(2) twins,promoted the random orientation of oxides and refined the oxide size of the TiBw/Ti55 composites with 3.5%volume fractions of TiBw,resulting in the best resistance against oxidation.展开更多
NiTi alloy has been widely used as orthopedic implant materials due to its unique shape memory properties and superelasticity.However,implantation failure often occurs because of the poor antibacterial ability,antioxi...NiTi alloy has been widely used as orthopedic implant materials due to its unique shape memory properties and superelasticity.However,implantation failure often occurs because of the poor antibacterial ability,antioxidation property and corrosion resistance of the NiTi alloy.In order to overcome the above problems,we constructed Zn/polydopamine(PDA)/Chitosan-Catechol(CS-C)composite coating on the surface of NiTi alloy in this paper.The surface morphology and wettability of the coating were characterized by scanning electron microscopy(SEM)and optical contact angle measuring instrument,respectively.The results showed that the Zn/CS-C coating was successfully prepared,and exhibited good hydrophilic property,especially the sample Zn/PDA/CS-C-24 h.In addition,the corrosion resistance,antioxidation property and biological properties of the coating were systematically analyzed.The results indicated that the Zn/PDA/CS-C composite coating exhibited good corrosion resistance and antibacterial property,antioxidant property and osteogenic activity,especially sample Zn/PDA/CS-C-24 h.The sample Zn/PDA/CS-C-24 h could effectively protect osteoblasts from reactive oxygen species(ROS)damage and promote cell proliferation and osteoblast differentiation.This study provides a feasible and effective strategy for the surface modification of orthopedic implant.展开更多
[Objective] The aim was to study the antioxidant effect of polyphenols from pomegranate peel in vivo. [Method] The Kunming rats were randomly divided into a control group, a low-dose group, a middle-dose group and a h...[Objective] The aim was to study the antioxidant effect of polyphenols from pomegranate peel in vivo. [Method] The Kunming rats were randomly divided into a control group, a low-dose group, a middle-dose group and a high-dose group,n=10; the protein content, the activities of the superoxide dismutase（SOD） and the glutathione peroxidase（GSH-PX）, the content of the maleic dialdehyde（MDA） in serum and liver tissue of the rats from different groups were determined. [Result]The polyphenols of pomegranate peel could increase protein content, activities of superoxide dismutase（SOD） and glutathione peroxidase（GSH-PX） in serum and liver tissue, and decrease the maleic dialdehyde（MDA） content simultaneously. [Conclusion] Polyphenols of pomegranate peel have strong antioxidant activity in vivo.展开更多
[Objective] The aim was to compare contents of free and bound polyphenol and antioxidation of balsam pear in different varieties. [Method] Fourteen varieties of balsam pear were chosen to analyze total contents of fre...[Objective] The aim was to compare contents of free and bound polyphenol and antioxidation of balsam pear in different varieties. [Method] Fourteen varieties of balsam pear were chosen to analyze total contents of free or bound phenol and components of free phenol. FRAP （Freeic reducing/antioxidant power）, DPPH （1,1diphenyl-2-picrylhydrazy）, and ABTS ＋· （2, 2’-azinobis-3-ethylbenzothiazoline-6-sulphonic acid diammonium salt） were used to measure antioxidation and analyze relationship between polyphenol content and antioxidation. [Result] Among the fourteen varieties of balsam pear, free, bound and total phenols were 157.58 -382.92, 6.46 -54 and 175.27 -413.79 mg GAE/100 g DW; coefficients of variance were 23.50% , 61.04% and 21.58%, respectively; free phenol accounted for 91.34% of total phenol and bound phenol accounted for 8.66% ; contents of total flavone for the fourteen varieties were from 8.97 to 18.22 mg CE/100 g DW and the coefficient was at 22.80%; vanillic aldehyde acid, epicatechin and rutin differed in contents among different varieties, which changed in 1.83-9.29, 35.17-114.52 and 0.91-4.53 mg/100 g DW and the coefficients were 43.85%, 26.97% and 33.09%; FRAP antioxidation was at 272.16 -713.32 mg TE/100 g DW and coefficient at 27.67% ; IC 50 of DPPH and ABTS ＋· clearance were 11.43-34.14 and 21.57-119.71 mg GAE/100 g DW and coefficients were at 35.10% and 63.75% , accordingly; content of total phenol was of extremely positive correlation with FRAP （P0.01） and of extremely negative correlation with IC 50 of DPPH and ABTS ＋ · clearance （P0.01）. [Conclusion] Contents of phenolic compounds and antioxidation are of significant genotype differences; and phenolic substance and antioxidation are mainly in free form and phenolic substance is the major basis for antioxidation.展开更多
Passiflora incarnata L.,commonly known as passionflower,is traditionally cultivated as an ornamental plant but has demonstrated diverse therapeutic potential.Its pharmacological effects are attributed to bioactive com...Passiflora incarnata L.,commonly known as passionflower,is traditionally cultivated as an ornamental plant but has demonstrated diverse therapeutic potential.Its pharmacological effects are attributed to bioactive compounds such as flavonoids and alkaloids,which influence multiple biological pathways.This review aims to summarise and critically analyse recent findings on the pharmacological properties of Passiflora incarnata L.,focusing on its neuropsychiatric,antioxidant,antimicrobial,and anticancer activities.A targeted literature search was conducted in PubMed,Scopus,Web of Science,and Google Scholar for peer-reviewed publications between 2000 to 2025.Relevant articles were screened,and a more appropriate article related to the objective of the review was selected.Some classical papers are also cited as per the requirement of the topic.Passiflora incarnata L.showed multifunctional medicinal properties with various applications in neuropsychiatry,oxidative stress management,antimicrobial agent,and as an anticancer agent.The U.S.Food and Drug Administration categorizes passionflower extracts as“generally recognized as safe”.However,most evidence remains preclinical,with methodological variation limiting generalisation.Standardised formulation,robust clinical trials,and in-depth in vivo studies are essential to establish its therapeutic relevance and safety in modern medicine.展开更多
TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing Ti...TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing TiB_(2)coatings have disadvantages such as high equipment costs,complicated processes,and highly toxic gas emissions.This paper proposes an environmentally friendly method,which requires inexpensive equipment and simple processing,for preparing TiB_(2)coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts.The produced TiB_(2)layer had an approximate thickness of 60μm and exhibited high density,outstanding hardness(38.2 GPa)and robust adhesion strength(51 N).Additionally,high-temperature oxidation experiments revealed that,at900℃,the TiB_(2)coating provided effective protection to the molybdenum substrate against oxidation for 3 h.This result indicates that the TiB_(2)coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.展开更多
Investigating structural and hydroxyl group effects in electrooxidation of alcohols to value-added products by solid-acid electrocatalysts is essential for upgrading biomass alcohols.Herein,we report efficient electro...Investigating structural and hydroxyl group effects in electrooxidation of alcohols to value-added products by solid-acid electrocatalysts is essential for upgrading biomass alcohols.Herein,we report efficient electrocatalytic oxidations of saturated alcohols(C_(1)-C_(6))to selectively form formate using Ni Co hydroxide(Ni Co-OH)derived Ni Co_(2)O_(4)solid-acid electrocatalysts with balanced Lewis acid(LASs)and Brønsted acid sites(BASs).Thermal treatment transforms BASs-rich(89.6%)Ni Co-OH into Ni Co_(2)O_(4)with nearly equal distribution of LASs(53.1%)and BASs(46.9%)which synergistically promote adsorption and activation of OH-and alcohol molecules for enhanced oxidation activity.In contrast,BASs-enriched Ni Co-OH facilitates formation of higher valence metal sites,beneficial for water oxidation.The combined experimental studies and theoretical calculation imply the oxidation ability of C1-C6alcohols increases as increased number of hydroxyl groups and decreased HOMO-LUMO gaps:methanol(C_(1))<ethylene glycol(C_(2))<glycerol(C3)<meso-erythritol(C4)<xylitol(C5)<sorbitol(C6),while the formate selectivity shows the opposite trend from 100 to 80%.This study unveils synergistic roles of LASs and BASs,as well as hydroxyl group effect in electro-upgrading of alcohols using solid-acid electrocatalysts.展开更多
The objective of this study was to investigate the correlations between antioxidations and the contents of the total phenolics and anthocyanin in 127 accessions of black soybean. A T-test, a fast clustering procedure,...The objective of this study was to investigate the correlations between antioxidations and the contents of the total phenolics and anthocyanin in 127 accessions of black soybean. A T-test, a fast clustering procedure, and a correlation coefficient analysis were used for experimentation. The variation ranges of the total antioxidant capacity （TAC）, the total phenolics, and anthocyanin contents in 127 black soybean accessions were 0.44-3.56, 7.05-74.82, and 0.22-1.87 mg g-l, respectively, displaying significant genotype differences. The major differences in TAC, the total phenolics, and the anthocyanin contents existed among various types of accessions from geographical regions. The differences between the accessions from black and yellow soybeans, spring and autumn, summer and autumn, Dongbeichun and Nanfangchun, Dongbeichun and Nanfangxia, Beifangchun and Nanfangchun, and Beifangchun and Nanfangxia were significant at 0.01 or 0.05 levels, respectively. The general tendency was that the TAC, the total phenolics, and the anthocyanin contents of Beifangchun accessions were higher than that of Dongbeichun ones, while that of Nanfangchun accessions were the worst. 127 black soybean accessions could be clustered into 6 clusters, which consisted of 3, 24, 20, 31, 37, and 12 accessions, respectively. The most significant （P 〈 0.01） correlations existed respectively between the TAC and the total showed that the total substances phenolics content, and the TAC and the anthocyanin content of black soybean. The results phenolics and anthocyanin in black soybean seed coat were the important antioxidation展开更多
The antioxidations and their correlations with total flavones and anthocyanin contents in different black rice varieties were studied. The results indicated that the great differences in total antioxidant capacity （...The antioxidations and their correlations with total flavones and anthocyanin contents in different black rice varieties were studied. The results indicated that the great differences in total antioxidant capacity （TAC）, scavenging free radical capacity （SFRC）, total flavones and anthocyanin contents existed among 242 black rice varieties. Comparisons of TAC, SFRC, total flavones and anthocyanin contents of different black rice types showed that the differences between black rice and white rice, indica one and japonica one, and nonglutinous one and glutinous one were significant at 0.01 levels, respectively. This showed that the TAC, SFRC, total flavones and anthocyanin contents of japonica type were higher than those of indica one, and nonglutinous type were higher than glutinous one. According to the fast clustering procedure, 242 black rice varieties could be clustered into 10 clusters, 184 indica rice varieties into 10 clusters, and 58 japonica rice varieties into 6 clusters. Most significant （P〈0.01） correlations existed between TAC and total flavones and anthocyanin contents, and between SFRC and total flavones and anthocyanin contents of black rice, respectively. This showed that the antioxidation of black rice was closely correlated with its active compositions of flavones and anthocyanin.展开更多
The Nd Fe B magnet powders were treated by organosilicon resins, silane coupling agent and dichromate salts. Using temperature tests, high temperature and high humidity tests, and DTA, the antioxidation behavior was...The Nd Fe B magnet powders were treated by organosilicon resins, silane coupling agent and dichromate salts. Using temperature tests, high temperature and high humidity tests, and DTA, the antioxidation behavior was studied. The results show that antioxidation characte ristics are improved remarkably.展开更多
Objective To investigate whether two kinds of in vitro prepared advanced glycation end products (AGEs), Glu-BSA and Gal-BSA, could change oxidation stress and anti-oxidation abilities in astrocytes, and thus might con...Objective To investigate whether two kinds of in vitro prepared advanced glycation end products (AGEs), Glu-BSA and Gal-BSA, could change oxidation stress and anti-oxidation abilities in astrocytes, and thus might contribute to brain injury. Methods Changes of GSH, MDA, SOD, MAO-B, nitric oxide were measured after AGEs treatment. Results Both 0.1 g/L Glu-BSA and Gal-BSA could slightly decrease GSH level, while 1 g/L of them significantly decreased GSH level by 35% and 43% respectively. The MDA levels of both 1 g/L AGEs treated groups (306±13 and 346±22) were higher than that of the normal group (189±18), which could be inhibited by free radical scavenger NAC. The SOD activities of both 1 g/L AGEs treated groups (67.0±5.2 and 74.0±11.0) were lower than that of the normal group (85.2±8.0). Both 0.1 g/L AGEs could slightly increase the activity of MAO-B, while 1 g/L of them could increase MAO-B activity by 1.5 and 1.7 folds respectively. Both AGEs stimulation could produce NO level by 1.7 and 2 folds respectively. Conclusion Enhanced levels of astrocytic oxidation stress and decrease of antioxidation abilities may contribute to, at least partially, the detrimental effects of AGEs in neuronal disorders and aging brain.展开更多
A new alkylene dihydrofuran glycoside（1） was isolated from the root bark ofMorus alba L.,along with moracin M-3′-O-β-D-glucopyranoside （2）,and moracin M-6,3′-di-O-β-D-glucopyranoside（3）.Compound 1 was identi...A new alkylene dihydrofuran glycoside（1） was isolated from the root bark ofMorus alba L.,along with moracin M-3′-O-β-D-glucopyranoside （2）,and moracin M-6,3′-di-O-β-D-glucopyranoside（3）.Compound 1 was identified as 2-methylene-3-methoxy-2, 5-dihydrofuran-4-O-β-D-glucopyranoside on the basis of chemical and spectroscopic data including 1D and 2D NMR spectral analysis.In addition,the antioxidant activity of 1 was evaluated using the 1,1-diphenyl-2-picrylhydrazyl（DPPH） and 2,2′-azinobis- 3-ethylbenzothiazoline-6-sulphonic acid（ABTS） assay.The IC_（50） values were 2.49 and 0.45 mg/mL,respectively.展开更多
Gelatin extracted from the body wall of the sea cucumber （Stichopus japonicus） was hydrolyzed with flavourzyme. Low-molecular-weight gelatin hydrolysate （LMW-GH） of 700-- 1700 Da was produced using an ultrafiltrat...Gelatin extracted from the body wall of the sea cucumber （Stichopus japonicus） was hydrolyzed with flavourzyme. Low-molecular-weight gelatin hydrolysate （LMW-GH） of 700-- 1700 Da was produced using an ultrafiltration membrane bioreaetor system. Chemiluminescence analysis revealed that LMW-GH scavenges high free radicals in a concentration-dependent manner; IC50 value for superoxide and hydroxyl radicals was 442 and 285 μgmL-1, respectively. LMW-GH exhibited excellent inhibitory characteristics against melanin synthesis and tyrosinase activity in B16 cells. Furthermore, LMW-GH notably increased in- traeellular glutathione （GSH）, which in turn suppressed melanogenesis. LMW-GH performs antioxidation activity, holding the potential of being used as a valuable ingredient in function foods, cosmetics and pharmaceuticals or nutriceuticals.展开更多
OBJECTIVE:To investigate the protective effect of curcumin extracted from Jianghuang(Rhizoma Curcumae Longae)against ultraviolet B(UVB)and the possible mechanism.METHODS:Effects of curcumin were detected in vivo and i...OBJECTIVE:To investigate the protective effect of curcumin extracted from Jianghuang(Rhizoma Curcumae Longae)against ultraviolet B(UVB)and the possible mechanism.METHODS:Effects of curcumin were detected in vivo and in vitro.Morphological changes of white guinea pig skin were assessed by hematoxylin and eosin staining.Ha CaT cell proliferation was measured by 3-[4,5-dimethylthylthiazol-2-yl]-2,5 diphenyltetrazolium broide(MTT)assays.The cell cycle distribution,apoptotic rate,level of reactive oxygen species(ROS),mitochondrial membrane potential,and intracellullar calcium ion concentration of Ha CaT cells were detected by flow cytometry.Antioxidant levels in skin tissues and Ha Cat cells were measured by biochemical methods.RESULTS:UVB inhibited in vitro cell proliferation by inducing G2/M arrest,increasing ROS,apoptosis,and necrosis,and decreasing B-cell lymphoma-2,and increasing Bax,cytochrome c,and caspase-3 levels.CONCLUSION:Curcumin blocks the effects of UVB by reducing ROS and apoptosis,and reversing UVB-induced changes in the expression of apoptotic proteins.The mitochondrial pathway is involved in curcumin-regulated apoptosis.展开更多
To improve the dispersion of silica in polypropylene（PP） matrix and to avoid physical loss of the antioxidants, nanosilica with dendric polyamidoamines on the surface（SG-PAMAM） was synthesized by using divergent m...To improve the dispersion of silica in polypropylene（PP） matrix and to avoid physical loss of the antioxidants, nanosilica with dendric polyamidoamines on the surface（SG-PAMAM） was synthesized by using divergent method. Then nanosilica-immobilized antioxidant（SG-PAMAM-AO） was prepared by grafting 2,6-di-tert-butyl-4-aminophenol which was derived from 2,6-di-tert-butyl-4-phenol（AO）. The SG-PAMAM-AO was added into PP by melt mixing to study the aging property. The oxidation induction time of PP/SG-PAMAM-AO and PP/AO compounds was measured. It was found that the antioxidant property of the SG-PAMAM-AO was superior to that of AO. According to the changes of carbonyl absorption before and after photo-thermal aging, the photo-thermal oxidative stability of PP/SG-PAMAM-AO was much higher than that of PP, PP/SG-PAMAM and PP/AO.展开更多
Objective: To investigate cosmetic potential of Syzygium aromaticum L.(S. aromaticum L.) and to determine its antioxidant and anti-wrinkling effects. Methods: Using highperformance liquid chromatography, eugenol compo...Objective: To investigate cosmetic potential of Syzygium aromaticum L.(S. aromaticum L.) and to determine its antioxidant and anti-wrinkling effects. Methods: Using highperformance liquid chromatography, eugenol component was quantitated. The antioxidant activity of S. aromaticum L. was analyzed by 2,2-diphenyl-1-picrylhydrazyl radical scavenging and superoxide dismutase like activities. To determine cell viability, elastase and matrix metalloproteinase-1(MMP-1) activity, human dermal fibroblasts(HS68) were treated with S. aromaticum L. The inhibitory effect of S. aromaticum L. on tumor necrosis factor alpha induced MMPs expression in HS68 was analyzed by realtime-PCR. Results: The eugenol content was confirmed in S. aromaticum L. S. aromaticum L. was observed to have high 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and superoxide dismutase like activity. S. aromaticum L. had no cytotoxicity against the HS68 and dose-dependently increased elastase inhibition. Moreover, S. aromaticum L. significantly decreased MMP-1 content and inhibited gene levels of MMP-1, MMP-2, MMP-3 and MMP-9. Conclusions: The findings suggest that S. aromaticum L. has great potential as a cosmeceutical ingredient with antioxidant and antiwrinkling effects.展开更多
Electromagnetic(EM)wave-absorbing materials with high-temperature-resistance are urgently desirable to eliminate EM interference in extreme conditions.Precursor derived ceramics(PDC)route is being evolved as an effect...Electromagnetic(EM)wave-absorbing materials with high-temperature-resistance are urgently desirable to eliminate EM interference in extreme conditions.Precursor derived ceramics(PDC)route is being evolved as an effective strategy to solve the puzzle.Herein,a single source hyperbranched polyborosi-lazane precursor containing hafnium(hb-PBSZ-Hf)is introduced and the SiBCNHf ceramic is obtained by further pyrolysis.The micro-sized tissues including HfC,SiC,HfB 2 nanocrystals and segregated carbons are in situ generated during annealing which not only increase EM wave absorption ability(minimum re-flection coefficient(RC_(min))is-56.71 dB with a thickness of 2.5 mm,effective absorption bandwidth(EAB)is 3.4 GHz),but also improve antioxidation property(less than 2 wt.%mass fluctuation at 1400℃in air).Theoretical simulation of complex permittivity suggests that SiBCNHf ceramic has an RC_(min)of less than-5 dB for the whole X-band even at 1100℃.Such SiBCNHf ceramic with superior high-temperature-resistance and antioxidation performance derived from single source precursors possesses great potential for EM wave absorbing coatings in high-temperature and harsh environments.展开更多
OBJECTIVE To make full of resource,the bioactivity and active constituent analysis were firstly system⁃atically investigated on damask rose flower residue(DRFR).METHODS DPPH and ABTS experiments were applied to assess...OBJECTIVE To make full of resource,the bioactivity and active constituent analysis were firstly system⁃atically investigated on damask rose flower residue(DRFR).METHODS DPPH and ABTS experiments were applied to assess the antioxidant activity of DRFR.Then,column chromatography was used to purify compounds from DRFR-A,and the chemical structure was identified using nuclear magnetic resonance(NMR).The total phenolic acid content was measured by folin-ciocalteu colorimetric method and the content of gallic acid the indicator ingredient,was detected by high performance liquid chromatography(HPLC).RESULTS By DPPH and ABTS experiments,an antioxidation extract(DRFR-A)was found and displayed a high activity both on DPPH(IC50:2.760 mg·L^-1)and ABTS(IC50:2.258 mg·L^-1)compared to positive control VC.Ten compounds were isolated and identified from DRFR-A,and the most are phenolic acids.Among them,pyrogallic acid,2-phenylethyl-3,4,5-trihydroxybenzoate,p-hydroxybenzoic acid and p-hydroxy⁃phenethyl alcohol were obtained from the plant for the first time.The content of total phenolic acids and main ingredient,gallic acid,in DRFR-A was determined as 63.73%and 5.12%,respectively.CONCLUSION This study provides reliable science data and lays the foundation for the development and utilization of rose residue,and hence for the full utilization of rose resources.展开更多
文摘BACKGROUND: Around the world more and more people suffer from acute alcoholism. The purpose of this study was to determine hepatic enzymes and oxidation/antioxidation in rats with acute alcoholism. METHODS: Rats were randomly divided into three groups; control, low-dose alcohol, and high-dose alcohol. Each al- cohol group ( n = 12) was intravenously infused with etha- nol at a dose of 0.3 or 0.7 g/kg body weight respectively. The control group (n =11) was intravenously infused with normal saline at a dose of 0.5 g/kg body weight. Blood was collected for detection of hepatic enzymes and index of oxidation/antioxidation. RESULTS: The ratio of AST to ALT was 2.44±0.46, 2.57± 0.60 and 3.03 ±0.46 in the three groups, and the difference was significant between the control and high-dose alcohol groups (P^0.05). No significant changes were observed in the levels of serum alanine aminotransferase (ALT), aspar- tate aminotransferase (AST), total protein (Tp), albumin (Alb), alkaline phosphatase (ALP), cholinesterase (ChE), total bilirubin (TB), C-reactive protein (CRP) and amy- lase. The levels of serum nitric oxide (NO) in the 3 groups were 39.2 ±73.25 mol/L, 42.30 ±4.60 mol/L and 47.86± 4.66 mol/L, and significant difference was seen between the control group and the high-dose alcohol group (P < 0.01). No significant difference was found in the levels of serum superoxide dismutase (SOD), glutathione (GSH), malondiethylaldehyde (MDA), and CRP in the 3 groups. CONCLUSION: The ratio of AST to ALT appears to be a useful index for acute alcohol intoxication. NO is involved in the mechanism of acute alcohol intoxication.
基金supported by the National Natural Science Foundation of China,Nos.82204360(to HM)and 82270411(to GW)National Science and Technology Innovation 2030 Major Program,No.2021ZD0200900(to YL)。
文摘Traumatic brain injury involves complex pathophysiological mechanisms,among which oxidative stress significantly contributes to the occurrence of secondary injury.In this study,we evaluated hypidone hydrochloride(YL-0919),a self-developed antidepressant with selective sigma-1 receptor agonist properties,and its associated mechanisms and targets in traumatic brain injury.Behavioral experiments to assess functional deficits were followed by assessment of neuronal damage through histological analyses and examination of blood-brain barrier permeability and brain edema.Next,we investigated the antioxidative effects of YL-0919 by assessing the levels of traditional markers of oxidative stress in vivo in mice and in vitro in HT22 cells.Finally,the targeted action of YL-0919 was verified by employing a sigma-1 receptor antagonist(BD-1047).Our findings demonstrated that YL-0919 markedly improved deficits in motor function and spatial cognition on day 3 post traumatic brain injury,while also decreasing neuronal mortality and reversing blood-brain barrier disruption and brain edema.Furthermore,YL-0919 effectively combated oxidative stress both in vivo and in vitro.The protective effects of YL-0919 were partially inhibited by BD-1047.These results indicated that YL-0919 relieved impairments in motor and spatial cognition by restraining oxidative stress,a neuroprotective effect that was partially reversed by the sigma-1 receptor antagonist BD-1047.YL-0919 may have potential as a new treatment for traumatic brain injury.
基金supported by the Special Project of the Central-Guided Local Science and Technology Development(Grant No.2022ZY2-JCYJ-01-06)the Key Research and Development Program(Grant No.2020-xxx-ZD-179-00-05)Prof.Lujun Huang Group at Harbin Institute of Technology for providing the TiBw/Ti55 composites.
文摘The oxidation behavior of Ti55 alloy and TiBw/Ti55 composites at temperatures ranging from 960 to 1000℃ was investigated by characterizing the surface and cross-section microstructure of specimens.Results showed that TiBw reinforcement accelerated the occurrence of Ti_(6O)/Ti_(3O) by dissolving oxygen in titanium in the starting oxidation stage,and the Ti_(6O)/Ti_(3O) transformed into TiO_(2) with the progression of oxidation.Meanwhile,TiBw reinforcement promoted the formation of(101)crystal planes to be beneficial to the growth of TiO_(2) twins.The cross-sectional characterization showed that the oxide layer of Ti55 alloy and TiBw/Ti55 composites from outside to inside was TiO_(2)+Al_(2)O_(3),TiO_(2),Ti-Sn compounds,Ti_(6O)/Ti_(3O) in sequence,which was confirmed by calculating the standard Gibbs free energy of the oxide nucleation.The TiBw reinforcement accelerated the occurrence of suboxides Ti_(6O)/Ti_(3O) by dissolving oxygen in titanium,and promoted the formation of(101)crystal planes which were beneficial to the growth of TiO_(2) twins.The optimal addition of TiBw induced the TiO_(2) twins,promoted the random orientation of oxides and refined the oxide size of the TiBw/Ti55 composites with 3.5%volume fractions of TiBw,resulting in the best resistance against oxidation.
基金jointly supported by the Natural Science Foundation of Shanxi Province(Nos.202203021222127,202403021212109).
文摘NiTi alloy has been widely used as orthopedic implant materials due to its unique shape memory properties and superelasticity.However,implantation failure often occurs because of the poor antibacterial ability,antioxidation property and corrosion resistance of the NiTi alloy.In order to overcome the above problems,we constructed Zn/polydopamine(PDA)/Chitosan-Catechol(CS-C)composite coating on the surface of NiTi alloy in this paper.The surface morphology and wettability of the coating were characterized by scanning electron microscopy(SEM)and optical contact angle measuring instrument,respectively.The results showed that the Zn/CS-C coating was successfully prepared,and exhibited good hydrophilic property,especially the sample Zn/PDA/CS-C-24 h.In addition,the corrosion resistance,antioxidation property and biological properties of the coating were systematically analyzed.The results indicated that the Zn/PDA/CS-C composite coating exhibited good corrosion resistance and antibacterial property,antioxidant property and osteogenic activity,especially sample Zn/PDA/CS-C-24 h.The sample Zn/PDA/CS-C-24 h could effectively protect osteoblasts from reactive oxygen species(ROS)damage and promote cell proliferation and osteoblast differentiation.This study provides a feasible and effective strategy for the surface modification of orthopedic implant.
基金Supported by Scientific Research Projects Units of Science and Technology Department of Xinjiang Uygur Autonomous Region for Financial Support(Project No.2013911072)~~
文摘[Objective] The aim was to study the antioxidant effect of polyphenols from pomegranate peel in vivo. [Method] The Kunming rats were randomly divided into a control group, a low-dose group, a middle-dose group and a high-dose group,n=10; the protein content, the activities of the superoxide dismutase（SOD） and the glutathione peroxidase（GSH-PX）, the content of the maleic dialdehyde（MDA） in serum and liver tissue of the rats from different groups were determined. [Result]The polyphenols of pomegranate peel could increase protein content, activities of superoxide dismutase（SOD） and glutathione peroxidase（GSH-PX） in serum and liver tissue, and decrease the maleic dialdehyde（MDA） content simultaneously. [Conclusion] Polyphenols of pomegranate peel have strong antioxidant activity in vivo.
基金Supported by Guangdong International Cooperation Program (2010B050600005)Guangdong Comprehensive Strategic Cooperation Project of CAS (2009B091300135)Guangdong Natural Science Foundation (10251064001000006)~~
文摘[Objective] The aim was to compare contents of free and bound polyphenol and antioxidation of balsam pear in different varieties. [Method] Fourteen varieties of balsam pear were chosen to analyze total contents of free or bound phenol and components of free phenol. FRAP （Freeic reducing/antioxidant power）, DPPH （1,1diphenyl-2-picrylhydrazy）, and ABTS ＋· （2, 2’-azinobis-3-ethylbenzothiazoline-6-sulphonic acid diammonium salt） were used to measure antioxidation and analyze relationship between polyphenol content and antioxidation. [Result] Among the fourteen varieties of balsam pear, free, bound and total phenols were 157.58 -382.92, 6.46 -54 and 175.27 -413.79 mg GAE/100 g DW; coefficients of variance were 23.50% , 61.04% and 21.58%, respectively; free phenol accounted for 91.34% of total phenol and bound phenol accounted for 8.66% ; contents of total flavone for the fourteen varieties were from 8.97 to 18.22 mg CE/100 g DW and the coefficient was at 22.80%; vanillic aldehyde acid, epicatechin and rutin differed in contents among different varieties, which changed in 1.83-9.29, 35.17-114.52 and 0.91-4.53 mg/100 g DW and the coefficients were 43.85%, 26.97% and 33.09%; FRAP antioxidation was at 272.16 -713.32 mg TE/100 g DW and coefficient at 27.67% ; IC 50 of DPPH and ABTS ＋· clearance were 11.43-34.14 and 21.57-119.71 mg GAE/100 g DW and coefficients were at 35.10% and 63.75% , accordingly; content of total phenol was of extremely positive correlation with FRAP （P0.01） and of extremely negative correlation with IC 50 of DPPH and ABTS ＋ · clearance （P0.01）. [Conclusion] Contents of phenolic compounds and antioxidation are of significant genotype differences; and phenolic substance and antioxidation are mainly in free form and phenolic substance is the major basis for antioxidation.
文摘Passiflora incarnata L.,commonly known as passionflower,is traditionally cultivated as an ornamental plant but has demonstrated diverse therapeutic potential.Its pharmacological effects are attributed to bioactive compounds such as flavonoids and alkaloids,which influence multiple biological pathways.This review aims to summarise and critically analyse recent findings on the pharmacological properties of Passiflora incarnata L.,focusing on its neuropsychiatric,antioxidant,antimicrobial,and anticancer activities.A targeted literature search was conducted in PubMed,Scopus,Web of Science,and Google Scholar for peer-reviewed publications between 2000 to 2025.Relevant articles were screened,and a more appropriate article related to the objective of the review was selected.Some classical papers are also cited as per the requirement of the topic.Passiflora incarnata L.showed multifunctional medicinal properties with various applications in neuropsychiatry,oxidative stress management,antimicrobial agent,and as an anticancer agent.The U.S.Food and Drug Administration categorizes passionflower extracts as“generally recognized as safe”.However,most evidence remains preclinical,with methodological variation limiting generalisation.Standardised formulation,robust clinical trials,and in-depth in vivo studies are essential to establish its therapeutic relevance and safety in modern medicine.
基金supported by the Original Exploratory Program of the National Natural Science Foundation of China(No.52450012)。
文摘TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing TiB_(2)coatings have disadvantages such as high equipment costs,complicated processes,and highly toxic gas emissions.This paper proposes an environmentally friendly method,which requires inexpensive equipment and simple processing,for preparing TiB_(2)coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts.The produced TiB_(2)layer had an approximate thickness of 60μm and exhibited high density,outstanding hardness(38.2 GPa)and robust adhesion strength(51 N).Additionally,high-temperature oxidation experiments revealed that,at900℃,the TiB_(2)coating provided effective protection to the molybdenum substrate against oxidation for 3 h.This result indicates that the TiB_(2)coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.
基金the financial support from the National Natural Science Foundation of China(52172110,52472231,52311530113)Shanghai"Science and Technology Innovation Action Plan"intergovernmental international science and technology cooperation project(23520710600)+1 种基金Science and Technology Commission of Shanghai Municipality(22DZ1205600)the Central Guidance on Science and Technology Development Fund of Zhejiang Province(2024ZY01011)。
文摘Investigating structural and hydroxyl group effects in electrooxidation of alcohols to value-added products by solid-acid electrocatalysts is essential for upgrading biomass alcohols.Herein,we report efficient electrocatalytic oxidations of saturated alcohols(C_(1)-C_(6))to selectively form formate using Ni Co hydroxide(Ni Co-OH)derived Ni Co_(2)O_(4)solid-acid electrocatalysts with balanced Lewis acid(LASs)and Brønsted acid sites(BASs).Thermal treatment transforms BASs-rich(89.6%)Ni Co-OH into Ni Co_(2)O_(4)with nearly equal distribution of LASs(53.1%)and BASs(46.9%)which synergistically promote adsorption and activation of OH-and alcohol molecules for enhanced oxidation activity.In contrast,BASs-enriched Ni Co-OH facilitates formation of higher valence metal sites,beneficial for water oxidation.The combined experimental studies and theoretical calculation imply the oxidation ability of C1-C6alcohols increases as increased number of hydroxyl groups and decreased HOMO-LUMO gaps:methanol(C_(1))<ethylene glycol(C_(2))<glycerol(C3)<meso-erythritol(C4)<xylitol(C5)<sorbitol(C6),while the formate selectivity shows the opposite trend from 100 to 80%.This study unveils synergistic roles of LASs and BASs,as well as hydroxyl group effect in electro-upgrading of alcohols using solid-acid electrocatalysts.
基金This work was supported by the National Natural Science Foundation of China （30200171）.
文摘The objective of this study was to investigate the correlations between antioxidations and the contents of the total phenolics and anthocyanin in 127 accessions of black soybean. A T-test, a fast clustering procedure, and a correlation coefficient analysis were used for experimentation. The variation ranges of the total antioxidant capacity （TAC）, the total phenolics, and anthocyanin contents in 127 black soybean accessions were 0.44-3.56, 7.05-74.82, and 0.22-1.87 mg g-l, respectively, displaying significant genotype differences. The major differences in TAC, the total phenolics, and the anthocyanin contents existed among various types of accessions from geographical regions. The differences between the accessions from black and yellow soybeans, spring and autumn, summer and autumn, Dongbeichun and Nanfangchun, Dongbeichun and Nanfangxia, Beifangchun and Nanfangchun, and Beifangchun and Nanfangxia were significant at 0.01 or 0.05 levels, respectively. The general tendency was that the TAC, the total phenolics, and the anthocyanin contents of Beifangchun accessions were higher than that of Dongbeichun ones, while that of Nanfangchun accessions were the worst. 127 black soybean accessions could be clustered into 6 clusters, which consisted of 3, 24, 20, 31, 37, and 12 accessions, respectively. The most significant （P 〈 0.01） correlations existed respectively between the TAC and the total showed that the total substances phenolics content, and the TAC and the anthocyanin content of black soybean. The results phenolics and anthocyanin in black soybean seed coat were the important antioxidation
基金This work was supported by the National Natural Science Foundation of China(39870537 and 39900087)
文摘The antioxidations and their correlations with total flavones and anthocyanin contents in different black rice varieties were studied. The results indicated that the great differences in total antioxidant capacity （TAC）, scavenging free radical capacity （SFRC）, total flavones and anthocyanin contents existed among 242 black rice varieties. Comparisons of TAC, SFRC, total flavones and anthocyanin contents of different black rice types showed that the differences between black rice and white rice, indica one and japonica one, and nonglutinous one and glutinous one were significant at 0.01 levels, respectively. This showed that the TAC, SFRC, total flavones and anthocyanin contents of japonica type were higher than those of indica one, and nonglutinous type were higher than glutinous one. According to the fast clustering procedure, 242 black rice varieties could be clustered into 10 clusters, 184 indica rice varieties into 10 clusters, and 58 japonica rice varieties into 6 clusters. Most significant （P〈0.01） correlations existed between TAC and total flavones and anthocyanin contents, and between SFRC and total flavones and anthocyanin contents of black rice, respectively. This showed that the antioxidation of black rice was closely correlated with its active compositions of flavones and anthocyanin.
文摘The Nd Fe B magnet powders were treated by organosilicon resins, silane coupling agent and dichromate salts. Using temperature tests, high temperature and high humidity tests, and DTA, the antioxidation behavior was studied. The results show that antioxidation characte ristics are improved remarkably.
基金This work was supported by a grant from the National Key Basic Research Development Program Foundation of China (No.G2000057010) a grant from the National Natural Science Foundation of China (No.30070827).
文摘Objective To investigate whether two kinds of in vitro prepared advanced glycation end products (AGEs), Glu-BSA and Gal-BSA, could change oxidation stress and anti-oxidation abilities in astrocytes, and thus might contribute to brain injury. Methods Changes of GSH, MDA, SOD, MAO-B, nitric oxide were measured after AGEs treatment. Results Both 0.1 g/L Glu-BSA and Gal-BSA could slightly decrease GSH level, while 1 g/L of them significantly decreased GSH level by 35% and 43% respectively. The MDA levels of both 1 g/L AGEs treated groups (306±13 and 346±22) were higher than that of the normal group (189±18), which could be inhibited by free radical scavenger NAC. The SOD activities of both 1 g/L AGEs treated groups (67.0±5.2 and 74.0±11.0) were lower than that of the normal group (85.2±8.0). Both 0.1 g/L AGEs could slightly increase the activity of MAO-B, while 1 g/L of them could increase MAO-B activity by 1.5 and 1.7 folds respectively. Both AGEs stimulation could produce NO level by 1.7 and 2 folds respectively. Conclusion Enhanced levels of astrocytic oxidation stress and decrease of antioxidation abilities may contribute to, at least partially, the detrimental effects of AGEs in neuronal disorders and aging brain.
文摘A new alkylene dihydrofuran glycoside（1） was isolated from the root bark ofMorus alba L.,along with moracin M-3′-O-β-D-glucopyranoside （2）,and moracin M-6,3′-di-O-β-D-glucopyranoside（3）.Compound 1 was identified as 2-methylene-3-methoxy-2, 5-dihydrofuran-4-O-β-D-glucopyranoside on the basis of chemical and spectroscopic data including 1D and 2D NMR spectral analysis.In addition,the antioxidant activity of 1 was evaluated using the 1,1-diphenyl-2-picrylhydrazyl（DPPH） and 2,2′-azinobis- 3-ethylbenzothiazoline-6-sulphonic acid（ABTS） assay.The IC_（50） values were 2.49 and 0.45 mg/mL,respectively.
基金supported by the National High-Tech Research and Development Project of China (No.2007AA091805)National Natural Science Foundation of China (Nos.30871944 and 30972284)National Key Technology Research and Development Program of China (No.2008BAD94B05)
文摘Gelatin extracted from the body wall of the sea cucumber （Stichopus japonicus） was hydrolyzed with flavourzyme. Low-molecular-weight gelatin hydrolysate （LMW-GH） of 700-- 1700 Da was produced using an ultrafiltration membrane bioreaetor system. Chemiluminescence analysis revealed that LMW-GH scavenges high free radicals in a concentration-dependent manner; IC50 value for superoxide and hydroxyl radicals was 442 and 285 μgmL-1, respectively. LMW-GH exhibited excellent inhibitory characteristics against melanin synthesis and tyrosinase activity in B16 cells. Furthermore, LMW-GH notably increased in- traeellular glutathione （GSH）, which in turn suppressed melanogenesis. LMW-GH performs antioxidation activity, holding the potential of being used as a valuable ingredient in function foods, cosmetics and pharmaceuticals or nutriceuticals.
基金Supported by grants from Jilin Health Technology Innovation(No.2019J069)Science and Technology Research Projects of the Education Department of Jilin Province(No.JJKH20180189KJ)the Science and Technology Development Plan of Jilin(No.20180101305JC)
文摘OBJECTIVE:To investigate the protective effect of curcumin extracted from Jianghuang(Rhizoma Curcumae Longae)against ultraviolet B(UVB)and the possible mechanism.METHODS:Effects of curcumin were detected in vivo and in vitro.Morphological changes of white guinea pig skin were assessed by hematoxylin and eosin staining.Ha CaT cell proliferation was measured by 3-[4,5-dimethylthylthiazol-2-yl]-2,5 diphenyltetrazolium broide(MTT)assays.The cell cycle distribution,apoptotic rate,level of reactive oxygen species(ROS),mitochondrial membrane potential,and intracellullar calcium ion concentration of Ha CaT cells were detected by flow cytometry.Antioxidant levels in skin tissues and Ha Cat cells were measured by biochemical methods.RESULTS:UVB inhibited in vitro cell proliferation by inducing G2/M arrest,increasing ROS,apoptosis,and necrosis,and decreasing B-cell lymphoma-2,and increasing Bax,cytochrome c,and caspase-3 levels.CONCLUSION:Curcumin blocks the effects of UVB by reducing ROS and apoptosis,and reversing UVB-induced changes in the expression of apoptotic proteins.The mitochondrial pathway is involved in curcumin-regulated apoptosis.
文摘To improve the dispersion of silica in polypropylene（PP） matrix and to avoid physical loss of the antioxidants, nanosilica with dendric polyamidoamines on the surface（SG-PAMAM） was synthesized by using divergent method. Then nanosilica-immobilized antioxidant（SG-PAMAM-AO） was prepared by grafting 2,6-di-tert-butyl-4-aminophenol which was derived from 2,6-di-tert-butyl-4-phenol（AO）. The SG-PAMAM-AO was added into PP by melt mixing to study the aging property. The oxidation induction time of PP/SG-PAMAM-AO and PP/AO compounds was measured. It was found that the antioxidant property of the SG-PAMAM-AO was superior to that of AO. According to the changes of carbonyl absorption before and after photo-thermal aging, the photo-thermal oxidative stability of PP/SG-PAMAM-AO was much higher than that of PP, PP/SG-PAMAM and PP/AO.
文摘Objective: To investigate cosmetic potential of Syzygium aromaticum L.(S. aromaticum L.) and to determine its antioxidant and anti-wrinkling effects. Methods: Using highperformance liquid chromatography, eugenol component was quantitated. The antioxidant activity of S. aromaticum L. was analyzed by 2,2-diphenyl-1-picrylhydrazyl radical scavenging and superoxide dismutase like activities. To determine cell viability, elastase and matrix metalloproteinase-1(MMP-1) activity, human dermal fibroblasts(HS68) were treated with S. aromaticum L. The inhibitory effect of S. aromaticum L. on tumor necrosis factor alpha induced MMPs expression in HS68 was analyzed by realtime-PCR. Results: The eugenol content was confirmed in S. aromaticum L. S. aromaticum L. was observed to have high 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and superoxide dismutase like activity. S. aromaticum L. had no cytotoxicity against the HS68 and dose-dependently increased elastase inhibition. Moreover, S. aromaticum L. significantly decreased MMP-1 content and inhibited gene levels of MMP-1, MMP-2, MMP-3 and MMP-9. Conclusions: The findings suggest that S. aromaticum L. has great potential as a cosmeceutical ingredient with antioxidant and antiwrinkling effects.
基金supported by the National Science Fund for Distinguished Young Scholars(No.52025034)National Science and Technology Major Project of China(No.J2019-VI-0017-0132).
文摘Electromagnetic(EM)wave-absorbing materials with high-temperature-resistance are urgently desirable to eliminate EM interference in extreme conditions.Precursor derived ceramics(PDC)route is being evolved as an effective strategy to solve the puzzle.Herein,a single source hyperbranched polyborosi-lazane precursor containing hafnium(hb-PBSZ-Hf)is introduced and the SiBCNHf ceramic is obtained by further pyrolysis.The micro-sized tissues including HfC,SiC,HfB 2 nanocrystals and segregated carbons are in situ generated during annealing which not only increase EM wave absorption ability(minimum re-flection coefficient(RC_(min))is-56.71 dB with a thickness of 2.5 mm,effective absorption bandwidth(EAB)is 3.4 GHz),but also improve antioxidation property(less than 2 wt.%mass fluctuation at 1400℃in air).Theoretical simulation of complex permittivity suggests that SiBCNHf ceramic has an RC_(min)of less than-5 dB for the whole X-band even at 1100℃.Such SiBCNHf ceramic with superior high-temperature-resistance and antioxidation performance derived from single source precursors possesses great potential for EM wave absorbing coatings in high-temperature and harsh environments.
基金National Natural Science Foundation of China(331/313400531021)
文摘OBJECTIVE To make full of resource,the bioactivity and active constituent analysis were firstly system⁃atically investigated on damask rose flower residue(DRFR).METHODS DPPH and ABTS experiments were applied to assess the antioxidant activity of DRFR.Then,column chromatography was used to purify compounds from DRFR-A,and the chemical structure was identified using nuclear magnetic resonance(NMR).The total phenolic acid content was measured by folin-ciocalteu colorimetric method and the content of gallic acid the indicator ingredient,was detected by high performance liquid chromatography(HPLC).RESULTS By DPPH and ABTS experiments,an antioxidation extract(DRFR-A)was found and displayed a high activity both on DPPH(IC50:2.760 mg·L^-1)and ABTS(IC50:2.258 mg·L^-1)compared to positive control VC.Ten compounds were isolated and identified from DRFR-A,and the most are phenolic acids.Among them,pyrogallic acid,2-phenylethyl-3,4,5-trihydroxybenzoate,p-hydroxybenzoic acid and p-hydroxy⁃phenethyl alcohol were obtained from the plant for the first time.The content of total phenolic acids and main ingredient,gallic acid,in DRFR-A was determined as 63.73%and 5.12%,respectively.CONCLUSION This study provides reliable science data and lays the foundation for the development and utilization of rose residue,and hence for the full utilization of rose resources.
