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.

Anti-oxidative stress treatment and current clinical trials

Oxidative stress disturbs the balance between the production of reactive oxygen species(ROS)and the detoxification biological process.It plays an important role in the development and progression of many chronic diseases.Upon exposure to oxidative stress or the inducers of ROS,the cellular nucleus undergoes some biological processes via different signaling pathways,such as stress adaption through the forkhead box O signaling pathway,inflammatory response through the IκB kinase/nuclear factor-κB signaling pathway,hypoxic response via the hypoxia-inducible factor/prolyl hydroxylase domain proteins pathway,DNA repair or apoptosis through the p53 signaling pathway,and antioxidant response through the Kelch-like ECH-associated protein 1/nuclear factor E2-related factor 2 signaling pathway.These processes are involved in many diseases.Therefore,oxidative stress has gained more attraction as a targeting process for disease treatment.Meanwhile,anti-oxidative stress agents have been widely explored in pre-clinical trials.However,only limited clinical trials are performed to evaluate the efficacy of anti-oxidative stress agents or antioxidants in diseases.In this letter,we further discuss the current clinical trials related to anti-oxidative stress treatment in different diseases.More pre-clinical studies and clinical trials are expected to use anti-oxidative stress strategies as disease treatment or dietary supplementation to improve disease treatment outcomes.

Study on Hydrogen Storage Properties,Anti-Oxide Ability and Rate Limiting Step of ZrCr-Based Alloy after Introducing Cobalt as Additive

In this work,the microstructure,hydrogen storage properties,anti-oxide ability and rate limiting step of Zr(Cr_(1−x)Co_(x))_(2)(x=0,0.2,0.4 and 0.6)alloys have been investigated.After studying the crystal structure,we found that all alloy samples could show C14-type phase but the alloy sample x=0 could also show a small amount of Cr phase.Rietveld fitting showed that lattice parameter and unit cell volume of C14-type phase decreased with increasing x.After further research,it was clear that the first hydrogen absorption capacity decreased with increasing x.But introducing more Co content had a positive influence on the effective hydrogen storage capacity and cyclic hydrogen absorption and desorption properties of the alloy sample.We also found that adding Co to ZrCr_(2)alloy could improve its anti-oxide ability.In addition to this,the rate limiting step model was also studied.

Anti-Oxidative Constituents of Ethanol Extract from Buckwheat Seeds by HPLC-Electro-Spray MS

The study investigates major anti-oxidative constituents of ethanol extracts from the seeds of common buckwheat and tartary buckwheat. Ethanol extracts from buckwheat seeds were arranged to react with 1,1-diphenyl-2-picrylhydrazyl （DPPH） free radical. HPLC was used to identify anti-oxidative constituents of the ethanol extracts, and electro-spray MS was used to characterize the structures of these identified anti-oxidative constituents to confirm them. The ethanol extracts of common buckwheat and tartary buckwheat seeds both had DPPH free radical-scavenging effect; HPLC analysis showed that the ethanol extracts of both common buckwheat and tartary buckwheat seeds presented two main anti-oxidation peaks, which correspondingly had same chromatographic retention times and spectral information; electro-spray MS analysis showed that the molecular weights and MS fragmentation patterns of the anti-oxidative constituents in the ethanol extracts from buckwheat seeds were the same as those of rutin and quercetin in the control samples. HPLC- MS/MS was capable of being used to rapidly identify anti-oxidative constituents in the extract of buckwheat seeds, and the main anti-oxidative constituents of buckwheat seed extract were mainly rutin and quercetin, and the anti-oxidative activity of quercetin was higher than that of rutin.

A Study on Anti-oxidative Activity of Soybean Peptideswith Linoleic Acid Peroxidation Systems

Soybean bioactive peptides（SBPs） were prepared from the isolated soybean protein by proteolysis with an alkaline protease, alcalase, at 50℃ and pH = 8.0. The dependence of hydrolysis time on hydrolysis degree and molecular weight distribution were examined. The hydrolysate was fractionated on a Sephadex G-25 column and the anti-oxidative activities of the fractions were detected by the method of pyrogallol auto-oxidation. The average chain length of soybean peptides that have anti-oxidative activity was estimated to be about 7. The anti-oxidative properties of the soy- bean peptide were also studied by using linoleic acid peroxidation systems. The optimal condition of the peroxidation system was set up, Vc/Cu^2 ＋ as the inducer at pH = 7.4 and 25 ℃. In addition, soybean peptides show higher antioxidative activity compared with GSH.

Reducing Dietary Cation-Anion Difference on Acid-Base Balance, Plasma Minerals Level and Anti-Oxidative Stress of Female Goats

Reducing dietary cation-anion difference （DCAD） has been proved an effective way to prevent milk fever in dairy cows. Based on the similar physiological gastro-intestinal tract anatomy and metabolic process between female goats and dairy cows, this study was conducted to evaluate the effects of varying DCAD on fluid acid-base status, plasma minerals concentration and anti-oxidative stress capacity of female goats. Urinary pH, plasma Ca, P and Mg; and anti-oxidative stress indices of total superoxide dismutase （T-SOD）, hydrogen peroxide （HzO2）, glutathione peroxidase （GSH-Px） and malondialdehyde （MDA） were determined to evaluate the effect. Forty-eight Guizhou black female goats （（15±1.9） mon of old, （22.3±3.75） kg of BW） were randomly allocated to 4 blocks of 12 goats each and were fed 1 of 4 diets differed in DCAD level （calculated as Na＋K-C1-S, mEq kg-1 DM）. Levels of DCAD were preliminarily designed to be control （＋ 150 mEq kg^-1 DM, CON）, high DCAD （＋300 mEq kg^-1 DM, HD）, low DCAD （0 mEq kg^-1 DM, LD） and negative DCAD （-150 mEq kg^-1 DM, ND）, respectively. A commercial anionic salts （Animate） and sodium bicarbonate （NaHCO3） were supplemented to reduce and increase DCAD level, respectively. There was no difference in dry matter intake for 4 groups of goats. Urine pH was aggressively decreased （P〈0.0001） with reduced DCAD and there was a strong association between DCAD and urine pH （R2=0.793, P〈0.0001）. Compared with CON and HD feeding of LD and ND resulted in greater （P〈0.05） plasma Ca concentration. Plasma P level was increased （P〈0.05） when anionic salts were supplemented. The DCAD alteration did not affected （P〉0.05） plasma Mg level. There was no significant （P〉0.05） difference in plasma GSH-Px activity and H202, but anionic salts supplementation in LD and ND significantly increased （P〈0.05） plasma T-SOD activity and tended to reduce MDA （P〈0.1） over HD and CON. Results from this study indicated that reducing DCAD could decrease urine pH and increase plasma Ca concentration of female goats. Additionally, reducing DCAD was helpful to enhance anti-oxidative stress capability of female goats.

Chemical analysis,antimicrobial and anti-oxidative properties of Daucus gracilis essential oil and its mechanism of action

Objective:To evaluate the essential oils(EO) composition,antimicrobial and antioxidant power of a local plant,Daucus gracilis(D.gracilis).Methods:The aerial parts of D.gracilis were subjected to hydro distillation by a Clevenger apparatus type to obtain the EO which had been analyzed by gas chromatography and gas chromatography coupled with mass spectrometry,and screened for antimicrobial activity against five bacteria and three fungi by agar diffusion method.The mechanism of action of the EO was determined on the susceptible strains by both of time kill assay and lysis experience.The minimal inhibitory concentrations were determined by agar macrodilution and micro-dilution methods.Anti-oxidative properties of the EO were also studied by free diphenyl-2-picrylhydrazyl radical scavenging and reducing power techniques.Results:The EO yielded 0.68(v/w).The chemical analysis presented two dominant constituents which were the elemicin(35.3%) and the geranyl acetate(26.8%).D.gracilis EO inhibited the growth of Bacillus cereus and Proteus mirabilis significantly with minimal inhibitory concentrations of 17.15 μg/mL by the agar dilution method and57.05 μg/mL and 114.1 μg/mL,respectively by liquid micro-dilution.A remarkable decrease in a survival rate as well as in the absorbance in 260 nm was recorded,which suggested that the cytoplasm membrane was one of the targets of the EO.The EO showed,also,important anti-oxidative effects with an IC50 of 0.002 mg/mL and a dosedependent reducing power.Conclusions:D.gracilis EO showed potent antimicrobial and anti-oxidative activities and had acted on the cytoplasm membrane.These activities could be exploited in the food industry for food preservation.

Supplementation of Yeast Extract to Practical Diet Improves the Growth, Anti-Oxidative Capacity and Intestinal Morphology of Shrimp Litopenaeus vannamei

Two control diets based on the commercial formula were designed to contain high(27%,D1)and low(22%,D2)levels of fish meal,respectively.Into D2,500,1000 and 1500 mg kg 1 of yeast extract were added,respectively,yielding three experimental diets(YE1 through YE3).Shrimp(initial body weight 0.30 g±0.02 g)were fed with the experimental diets,five tanks each diet and 30 shrimp individuals each tank,for 8 weeks,and then challenged with Vibrio parahaemolyticus.The results showed that the specific growth rate(SGR)of shrimp in D2 was significantly lower than that of shrimp in D1(P<0.05).The SGR of shrimp in YE3 was similar to that of shrimp in D1.The feed intake of shrimp was similar between D1 and D2.The feed conversion ratio and protein efficiency ratio of shrimp were similar among all diets(P>0.05).YE significantly improved the activity of glutathione S-transferase.The concentration of glutathione(GSH)and the total serum anti-oxidative capacity(T-AOC)of D1 were significantly higher than those of shrimp feeding other diets(P<0.05).The content of serum malondialdehyde of shrimp feeding YE2 and YE3 was signifi-cantly lower than that of shrimp feeding D2(P<0.05).The thickness of intestine muscular layer of shrimp feeding YE1 and YE2 was similar to that of shrimp feeding D1.The shrimp feeding YE1 showed the highest villus height of intestine among all groups.The cumulative mortality after challenging was similar among all groups(70.00%86.67%)(P>0.05).In conclusion,1000 1500 mg kg 1 of YE was suggested to be supplemented into the practical diets to improve the growth,anti-oxidative capacity and intestinal mor-phology of shrimp L.vannamei.

Effects of vitamin C deficiency or excess on growth performance, anti-oxidative response and fatty acid composition of juvenile abalone Haliotis discus hannai Ino

A 240-day feeding trial was conducted to investigate the effects of dietary vitamin C on growth performance,anti-oxidative response,and fatty acid composition of juvenile abalone Haliotis discus hannai Ino(initial body weight:0.93±0.00 g).Three semi-purified experimental diets were formulated containing 0.00,94.52,and 9649.58 mg/kg of vitamin C supplied as L-ascorbyl-2-monophosphate.The results show that there was no significant difference in weight gain ratio,daily increment in shell length,and survival rate among the three treatments.Adding dietary vitamin C(9649.58 mg/kg)significantly increased the activities of superoxide dismutase(SOD),glutathine peroxidase(GPX),glitathione-S-transferase(GST),glutathione reductase(GR),alkaline phosphatase(AKP),and lysozyme in viscera(P<0.05).In muscle,activities of phenoloxidase,catalase,SOD,GST,GR,and AKP were increased in the treatment with 9649.58 mg/kg of dietary vitamin C(P<0.05).The highest concentrations of ascorbic acid in viscera and muscle were found in the group with 9649.58 mg/kg of dietary vitamin C(P<0.05).The contents of crude protein and crude lipid in the soft body were significantly increased in the 9649.58 mg/kg group(P<0.05).Dietary vitamin C supplementation significantly decreased the contents of saturated fatty acids(14:0,16:0,and 18:0),and increased the composition of 18:2n-6 and 22:6n-3 in the soft body of abalone(P<0.05).Therefore,although there were no significant effects on the growth performance,dietary vitamin C supplementation improved the anti-oxidation and immune responses,increased specific unsaturated fatty acid(i.e.,16:1,18:1n-7,18:1n-9,18:2n-6 and 22:6n-3),and decreased specific saturated fatty acid(i.e.,14:0,16:0 and 18:0)contents in the soft body of abalone.

在线学习个性化推荐中多维度学习者模型研究

随着在线学习平台的广泛使用,在线学习资源快速增长,“信息迷航”问题亟待解决。针对在线学习个性化推荐中以单一特征为主,多维度学习者模型研究较少的问题,文中以CELTS-11学习者模型规范为基础,以教育学相关理论为指导,对学习者的学习风格、知识状态、认知能力、兴趣偏好等多维度的个性化特征进行细化分类研究。利用教育数据挖掘等技术获得学习者特征项,进而构建出个性化的多维度学习者模型。该模型为后续在线学习个性化的推送服务提供有力的依据。

学科交叉教学研究模式在医学研究生创新能力培养中的应用效果

目的 探讨学科交叉教学研究模式在医学研究生创新能力培养中的应用效果。方法 采用问卷调查的方式,对45名浙江大学临床医学院参与学科交叉教学研究的医学研究生进行了调查。问卷内容涵盖学生的年级分布、对学科交叉重要性的看法、学科交叉在解决专业问题中的作用、以及对当前学科交叉教育与培训的满意度等方面。结果 调查显示,42.22%的学生认为学科交叉在创新能力培养中非常重要,33.33%认为比重较大。44.44%的学生认为学科交叉对提升专业能力和创新思维非常有帮助,48.89%强烈认同它有助于开阔研究视野和增强团队合作与交流能力。此外,84.44%的学生认为有必要进行教育体制改革以促进学科交叉教学研究。结论 学科交叉教学研究模式在医学研究生中得到了积极的评价,并能提升学生的专业能力和创新思维能力。尽管如此,一些学生对学科交叉的充分性及现有教育体制改革仍持保留态度。因此,未来的教育改革应更加关注实践机会的提供和跨学科教学内容的质量,以满足医学研究生对于高质量教育的需求,并促进他们在未来医疗领域的全面发展。

Resveratrol combats chronic diseases through enhancing mitochondrial quality

Resveratrol(RSV),as a functional food component extracted from natural plants,has been widely studied and recognized in preventing and treating various diseases,with major mechanisms including executing anti-inflammation and anti-oxidation functions,and improving mitochondrial quality.Chronic diseases as non-communicable diseases are mainly caused by multiple factors,such as physiological decline and dysfunction in the body,and have become a significant challenge on public health worldwide.It is worth noting that chronic diseases such as Alzheimer's disease(AD),Parkinson's disease(PD),muscle atrophy,cardiovascular disease,obesity,and cancer are accompanied by abnormal mitochondrial function.Therefore,targeted regulation of mitochondria may be a meaningful way to prevent and treat chronic diseases.Increasing evidence has confirmed that RSV is actively involved in regulating mitochondria,and it has become an essential consideration to prevent and treat chronic diseases through targeting mitochondria and improving corresponding functions.In this article,current studies on RSV to optimize mitochondrial quality for preventing and alleviating chronic disease are systematically summarized,which can provide a theoretical reference for the development of functional foods or drugs to combat chronic diseases.

Effects of Zn Stress on Zn Accumulation and Anti-Oxidant Enzymes Activity in Four Varieties of Ryegrass

We investigated the influence of different content of Zn^2＋（0, 2, 4, 8, 16 mmol·kg^-1） on plant growth, activities of peroxidase （POD） and superoxide dismutase （SOD）, free proline content and Zn accumulation in four varieties of ryegrass （Loliurn perenne L.） hy pot cuhure experiment. The results showed that plant hiomass increased at the ranges of 0-2 （Tuoya）, 0-4 （Yey- ing）, 0-8 mmol·kg^-1（Airuisi and Taide）, respectively, and then decreased under excess Zn. The activities of POD ,SOD and proline content in shoots decreased firstly, and then increased with the in crease of Zn content. The plaut biomass, activities of POD and SOD in Taide were evidently higher than in the other three varie ties. Root tolerance index （RTI） and Zn transport ratio from root to shoot （S/R） in Taide were exceed 1. 0. The maximum of Zn content was 583.9 mg/kg （ at 16 mmol·kg^-1） in Taide＇s shoot.

Anti-oxidant and anti-inflammatory activities of ultrasonicassistant extracted polyphenol-rich compounds from Sargassum muticum

Polypehnol is an important,potentially bioactive component of Sargassum muticum.In this study,ultrasonic assisted extraction of polyphenol-rich substances was performed using a 38%ethanol solution at a solid:liquid ratio of 1:30 at 68℃ for 32min,determined by single-factor and response surface methodology(RSM)optimization.The content of polyphenol was 5.66mg/g in the crude extract.Further extraction showed that the polyphenol mainly distributed in ethyl acetate(SKEE)and water phases(SKEW).The anti-oxidation test by electron spin resonance(ESR)spectrum showed that the SKEE had the strongest scavenging activity on DPPH(1,1-diphenyl-2-picrylhydrazyl)and alkyl radicals.SKEE was shown noncytotoxic but could inhibit the generation of cellular ROS,showing protective effects in H2O2 and AAPHinduced Vero cells and UV-B irradiated HaCaT cells.SKEE also signifi cantly inhibited the release of NO of LPS-induced RAW 264.7 cells.Therefore,the polyphenol-rich extracts in ethanol and ethyl acetate showed excellent anti-oxidant and anti-infl ammatory activities,which is beneficial to the development of high-value bio-substances.

Sperm quality improvement after natural anti-oxidant treatment of asthenoteratospermic men with leukocytospermia

Aim： To study the immune-modulating and anti-oxidant effects of beta-glucan, papaya, lactoferrin, and vitamins C and E on sperm characteristics of patients with asthenoteratozoospermia associated with leucocytosis. Methods： Fifty-one patients referred to our Sterility Center for semen analysis were selected. Sperm parameters were assessed before and after patient＇s treatment with beta-glucan, lactoferrin, papaya, and vitamins C and E. DNA damage was assessed by the acridine orange test and sperm structural characteristics were evaluated by transmission electron microscopy. Results： After 90 days of treatment, an increase in the percentage of morphologically normal sperm （17.0 ± 5.2 vs. 29.8 ± 6.5） and total progressive motility （19.0± 7.8 vs. 34.8 ± 6.8） were detected. Structural sperm characteristics as well as chromatin integrity were also improved after treatment. In terms of leukocyte concentration in seminal fluid, a significant reduction was recorded （2.2 ± 0.9 vs. 0.9± 0.2）. Conclusion： The treatment of an inflammatory process by the synergic action of immune modulators and anti-oxidants could protect sperm during maturation and migration, leading to improved sperm function. （Asian JAndrol 2008 Mar;. 10： 201-206）

Etomidate affects the anti-oxidant pathway to protect retinal ganglion cells after optic nerve transection

Our previous studies revealed that etomidate, a non-barbiturate intravenous anesthetic agent, has protective effects on retinal ganglion cells within 7 days after optic nerve transection. Whether this process is related to anti-oxidative stress is not clear. To reveal its mechanism, we established the optic nerve transection injury model by transecting 1 mm behind the left eyeball of adult male Sprague-Dawley rats. The rats received an intraperitoneal injection of etomidate(4 mg/kg) once per day for 7 days. The results showed that etomidate significantly enhanced the number of retinal ganglion cells retrogradely labeled with Fluorogold at 7 days after optic nerve transection. Etomidate also significantly reduced the levels of nitric oxide and malonaldehyde in the retina and increased the level of glutathione at 12 hours after optic nerve transection. Thus, etomidate can protect retinal ganglion cells after optic nerve transection in adult rats by activating an anti-oxidative stress response. The study was approved by the Animal Ethics Committee at Air Force Medical University, China(approval No. 20180305) on March 5, 2018.

Preparation and Properties of Anti-oxidation Inorganic Nano-coating for Low Carbon Steel at an Elevated Temperature

A new kind of anti-oxidation inorganic nano-coating for the common low carbon steel was prepared. It included magnesite mineral, metallurgic dust and silicate adhesive as the main raw materials. The nano-coating could be sprayed directly onto the low carbon steel slab even though with hot surface as far as under 1000 ℃ . And at the same time, a compact thin nano-film was formed, and the film would inhibit the oxygen into the interface of the steel body and decrease the loss of weight because of oxidation. The loss was decreased by about 60% or more. The properties and mechanism of oxidation resistance of the coating were discussed through XRD, TG-DTA and SEM. The experimental results show that many reactions would happen among the companents of the coating and then many microspheres with the size of 80- 100nm generated in the system. By using the heat of the steel body, the silicate adhesive would interact with the microspheres, and the other components of the coating would be soft and sintered so that when the coating was sprayed onto the suface of the steel slab , the intact and compact film could be formed and adhesive with the steel body. Besides the special properties of anti- oxidation, the coating could prevent the volatilization of microelement in the steel such as silicate and carbon at a high temperature. So it can improve the quality and output of steel with this new kind of nano-coating.

Anti-Obesity, Anti-Atherosclerotic and Anti-Oxidant Effects of Pu-Erh Tea on a High Fat Diet-Induced Obese Rat Model

Pu-erh tea, a traditional Chinese beverage, has been believed to have many benefits to human health and without side effects. In this study, we systematically analyzed the main active components of Pu-erh tea and investigated its anti-obesity, anti-atherosclerotic and anti-oxidant effects using an obese rat model. Obesity was induced by feeding a high-fat diet and subsequently the experimental obese mice were fed with high-fat diet supplemented with low (2.5%), medium (5%) or high (7.5%) doses of Pu-erh tea powder for 6 weeks respectively. As result, the body weight gain of the rats was decreased by medium and high doses of Pu-erh tea treatments. Furthermore, the levels of serum total cholesterol (TC), triglyceride (TG) and atherosclerosis index (AI) were significantly lowered by Pu-erh tea compared to the control group. Conversely, high density lipoproteincholesterol (HDL-C) level of the rats was significantly elevated by Pu-erh tea treatments. In addition, Pu-erh tea treatments increased the activities of anti-oxidative enzymes such as superoxide dismutase (SOD) and glutathione peroxides (GSH-Px), whereas reduced the level of lipid peroxidation product malondialdehyde (MDA) in obese rats. Collectively, our find-ings revealed that Pu-erh tea exerts comprehensive benefits in anti-obesity, anti-atherosclerotic and anti-oxidant effects, therefore can be used as a promising functional food in obesity management.

Microstructure of a Mo-Si-C-N multi-layered anti-oxidation coating on carbon/carbon composites by fused slurry

A Mo-Si-C-N multi-layered anti-oxidation coating was in-situ fabricated by introducing nitrogen atmosphere during the fused sintering of Mo-Si slurry pre-layer on carbon/carbon composites. The phase composition and microstructure of the Mo-Si-C-N coating were characterized by X-ray diffractometry, optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. The Mo-Si-C-N coating exhibited a three-layered structure. Besides the MoSi2/Si main-layer and the SiC bonding-layer, a surface layer of about 10 μm in thickness was synthesized on the coating surface. The surface layer mainly consisted of SiC nanowires and contained some Si3N4 and Si phases. SiC nanowires of 10 to 200 nm in diameter presented a terrace and distortion structure. Transmission electron microscopy indicated that the SiC nanowires grew along the preferred 〈111〉 direction. During oxidation test, SiC nanowires transmuted into SiO2 glass, which can play an important role in improving the oxidation resistance of C/C composites.

Preparation and Anti-oxidation Mechanism of Mullite/Yttrium Silicate Coatings on C/SiC Composites

In order to enhance the oxidation resistance of C/Si C composites, mullite/yttrium silicate coatings were fabricated on C/Si C composites through dip-coating route. Al_2O_3-SiO_2 sol with high solid content was selected as the raw material for mullite and ＂silicone resin ＋ Y_2O_3 powder＂ slurry was used to synthesize yttrium silicate. The microstructure and phase composition of coatings were characterized, and the investigation on oxidation resistance and anti-oxidation mechanism was emphasized. The as-fabricated coatings consisting of SiO_2-rich mullite phase and Y_2Si_2O_7 phase show high density and favorable bonding to C/Si C composites. After oxidized at 1 400 ℃ and 1 500 ℃ for 30 min in static air, the coating-containing C/Si C composites possess 91.9% and 102.4% of the original flexural strength, respectively. The desirable thermal stability of coatings and the further densification of coatings due to viscous flow of rich SiO_2 and Y-Si-Al-O glass are responsible for the excellent oxidation resistance. In addition, the coating-containing composites retain 99.0% of the original flexural strength and the coatings exhibit no cracking and desquamation after 12 times of thermal shock from 1 400 ℃ to room temperature, which are ascribed to the combination of anti-oxidation mechanism and preferable physical and chemical compatibility among C/Si C composites, mullite and Y_2Si_2O_7. The carbothermal reaction at 1 600 ℃ between free carbon in C/Si C substrate and rich SiO_2 in mullite results in severe frothing and desquamation of coatings and obvious degradation in oxidation resistance.