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Protective effect of ascorbic acid on cyclophosphamide induced testicular gametogenic and androgenic disorders in male rats 被引量:28
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作者 Ujjal Baran Das Mousumi Mallick +1 位作者 Jogendra Mohan Debnath Debidas Ghosh 《Asian Journal of Andrology》 SCIE CAS CSCD 2002年第3期201-207,共7页
Aim:To study the detrimental effects of cyclophosphamide on the testicular androgenic and gametogenic activities through endocrine inhibition and/or induction of oxidative stress in male albino rats and to evaluate th... Aim:To study the detrimental effects of cyclophosphamide on the testicular androgenic and gametogenic activities through endocrine inhibition and/or induction of oxidative stress in male albino rats and to evaluate the protective effect of ascorbic acid.Methods:The testicular△^(5),3β-hydroxysteroid dehydrogenase(HSD),17β-HSD,peroxidase and catalase activities along with the levels of malondialdehyde(MDA)and conjugated dienes in testicular tissue were measured for the evaluation of testicular oxidative stress.The plasma testosterone(T)level was measured by immunoassay.Various germ cells at stageⅦof spermatogenic cycle were quantified from testicular stained sections.Results:Cyclophosphamide treatment results in a significant inhibition in the testicular△^(5),3β-HSD and 17β-HSD activities,a decrease in plasma T level and a diminution in the counts of various germ cells.Moreover,this treatment was also associated with a significant inhibition of the peroxidase and catalase activities along with high levels of MDA and conjugated dienes in the testis.All these changes were reversed by ascorbic acid co-administration.Conclusion:Cyclophosphamide treatment at the dosage used caused testicular gametogenic and androgenic disorders as well as induced testicular oxidative stress that can be reversed by ascorbic acid co-administration. 展开更多
关键词 CYCLOPHOSPHAMIDE ANDROGENESIS GAMETOGENESIS oxidative stress free radicals ascorbic acid CATALASE PEROXIDASE testosterone
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Low-volume plus ascorbic acid vs high-volume plus simethicone bowel preparation before colonoscopy 被引量:24
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作者 Stefano Pontone Rita Angelini +4 位作者 Monica Standoli Gregorio Patrizi Franco Culasso Paolo Pontone Adriano Redler 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第42期4689-4695,共7页
AIM: To investigate the effectiveness of low-volume plus ascorbic acid [polyethylene glycol plus ascorbic acid (PEG + Asc)] and high-volume plus simethicone [polyethylene glycol plus simethicone (PEG + Sim)] bo... AIM: To investigate the effectiveness of low-volume plus ascorbic acid [polyethylene glycol plus ascorbic acid (PEG + Asc)] and high-volume plus simethicone [polyethylene glycol plus simethicone (PEG + Sim)] bowel preparations. METHODS: A total of one hundred and forty-four outpatients (76 males), aged from 20 to 84 years (median age 59.5 years), who attended our Department, were divided into two groups, age and sex matched, and underwent colonoscopy. Two questionnaires, one for patients reporting acceptability and the other for endoscopists evaluating bowel cleansing effectiveness according to validated scales, were completed. Indications, timing of examination and endoscopical findings were recorded. Biopsy forceps were used as a measuring tool in order to determine polyp endoscopic sizeestimation. Difficulty in completing the preparation was rated in a 5-point Likert scale (1 = easy to 5 = unable). Adverse experiences (fullness, cramps, nausea, vomiting, abdominal pain, headache and insomnia), number of evacuations and types of activities performed during preparation (walking or resting in bed) were also investigated. RESULTS: Seventy-two patients were selected for each group. The two groups were age and sex matched as well as being comparable in terms of medical history and drug therapies taken. Fourteen patients dropped out from the trial because they did not complete the preparation procedure. Ratings of global bowel cleansing examinations were considered to be adequate in 91% of PEG + Asc and 88% of PEG + Sim patients. Residual Stool Score indicated similar levels of amount and consistency of residual stool; there was a significant difference in the percentage of bowel wall visualization in favour of PEG + Sim patients. In the PEG + Sire group, 12 adenomas≤ 10 mm diameter (5/left colon + 7/right colon) vs 9 (8/left colon + 1/right colon) in the PEG + Asc group were diagnosed. Visualization of small lesions seems to be one of the primary advantag 展开更多
关键词 Bowel preparation Polyethylene glycol ascorbic acid COLONOSCOPY SIMETHICONE
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Recovery of rare earths from ion-absorbed rare earths ore with MgSO_4-ascorbic acid compound leaching agent 被引量:10
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作者 Fuguo Lai Li Huang +2 位作者 Guohua Gao Run Yang Yanfei Xiao 《Journal of Rare Earths》 SCIE EI CAS CSCD 2018年第5期521-527,共7页
The magnesium sulfate leaching technology for the ion-absorbed rare earths ore can solve the ammonia pollution problem existing in ammonium sulfate leaching process. However, the leaching capacity of magnesium sulfate... The magnesium sulfate leaching technology for the ion-absorbed rare earths ore can solve the ammonia pollution problem existing in ammonium sulfate leaching process. However, the leaching capacity of magnesium sulfate is slightly weaker than that of ammonium sulfate, resulting in a bigger consumption of magnesium sulfate. In this paper, the MgSO4-ascorbic acid compound leaching agent had been demonstrated to deal with the ion-absorbed rare earths ore. The ascorbic acid could form a stable coordination with rare earth ions, so that it can strengthen the leaching of ion-exchangeable phase.Moreover, ascorbic acid has a strong reductive property, it can leach the colloidal sediment phase rare earth as well. The present study investigates the effect of the initial pH and the composition of leaching agent on the rare earth leaching. It is determined that the rare earth leaching efficiency is 107.5% under the condition of pH 2.00,0.15 mol/L magnesium sulfate and 1.0 g/L ascorbic acid in leaching agent. In this case, the content of the ion-exchangeable phase and colloidal sediment phase rare earth in the leaching residues are both only 0.02‰. The leaching efficiency of colloid sediment phase rare earth can be 85.7%,so that the Ce partition in the leaching liquor increases to be 5.77%. The magnesium-ascorbic acid compound leaching agent is proposed to be a promising choice to deal with the ion-absorbed rare earths ore, which can realize the efficient leaching, low consumption of MgSO4 and environmentally friendly leaching. 展开更多
关键词 Rare earth LEACHING MgSO4 ascorbic acid Ion-absorbed rare earths ore
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油溶性纳米铜的制备及其在SF15W/40汽油机油中的摩擦学性能(英文) 被引量:12
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作者 潘秋红 张锡凤 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2010年第10期1711-1714,共4页
采用液相化学还原法结合界面生长法,以醋酸铜为母体,维生素C(Vc)为还原剂,聚乙二醇2000为修饰剂,正丁醇为生长剂,制得粒度分布为18.2~80.2nm、平均粒度为44.7nm的油溶性球形纳米Cu样品。XRD分析表明样品的晶格常数膨胀率为1.478%。将... 采用液相化学还原法结合界面生长法,以醋酸铜为母体,维生素C(Vc)为还原剂,聚乙二醇2000为修饰剂,正丁醇为生长剂,制得粒度分布为18.2~80.2nm、平均粒度为44.7nm的油溶性球形纳米Cu样品。XRD分析表明样品的晶格常数膨胀率为1.478%。将样品添加到SF15W/40汽油机油中制得金属纳米润滑油。高浓度激光粒度仪检测表明,该金属纳米润滑油具有优异的分散稳定性。在UMT-Ⅱ摩擦磨损试验机上考察SF15W/40汽油机油、金属纳米润滑油的摩擦磨损性能。结果表明:与SF15W/40汽油机油相比,金属纳米润滑油较大程度降低了摩擦系数,减小了磨损量,显著改善了SF15W/40汽油机油的摩擦性能;纳米Cu的最佳添加量为0.8%。 展开更多
关键词 油溶性 纳米铜 制备 汽油机油 摩擦学性能 Lubricating OIL CU NANOPARTICLES TRIBOLOGICAL Behavior CU NANOPARTICLES lubricating OIL 金属纳米 particle size distribution 润滑油 TRIBOLOGICAL performance friction coefficient lattice parameters interface growth 液相化学还原法 摩擦磨损试验机 ascorbic acid
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Effect of Ascorbic Acid and Silicium on Photosynthesis, Antioxidant Enzyme Activity, and Fatty Acid Contents in Canola Exposure to Salt Stress 被引量:9
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作者 Ahmad Bybordi 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第10期1610-1620,共11页
The effects of exogenous ascorbic acid and silicium on leaf fresh weigh, seed yield, photosynthesis, changes of the activities of major antioxidant enzymes, nitrate reductase activity, proline accumulation, chlorophyl... The effects of exogenous ascorbic acid and silicium on leaf fresh weigh, seed yield, photosynthesis, changes of the activities of major antioxidant enzymes, nitrate reductase activity, proline accumulation, chlorophyll content, and fatty acid composition were investigated in salt-stressed canola. A hydroponic pot experiment was conducted based on randomized complete block design, factorial arrangement was used with 16 combinations of salinity stress (0, 100, 200, and 300 mmol L-1 NaC1), ascorbic acid (0 and 30 mmol L-1), and silicium (2 and 4 mmol L-1 from potassium silicate) with three replicates. The results showed that salinity significantly decreased leaf area and leaf fresh weight, seed yield, photosynthesis, nitrate reductase activity, chlorophyll content, and seed protein percentage. Conversely, respiration, antioxidant enzymes activity, proline accumulation, and linolenic acid percentage increased due to salt stress. Ascorbic acid application improved photosynthesis and seed yield and mitigated antioxidant enzyme activity. In addition, nitrate reductase activity and chlorophyll a and b were positively affected by ascorbic acid. Regarding silicium application, that was found that leaf area, leaf fresh weight, seed yield and photosynthesis, ascorbate peroxidase activity, nitrate reductase activity, and chlorophyll content increased, while respiration decreased. Furthermore, silicium had not significant effect on antioxidant enzyme activity. In general, ascorbic acid and silicium were involved in the defensive mechanisms against salinity stress and it can be suggested that, ascorbic acid and silicium application had positive effect on canola growth under conditions of salt stress. 展开更多
关键词 ascorbic acid salt stress CANOLA SILICIUM
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Optimisation of Adventitious Shoot Regeneration and Agrobacterium-mediated Transformation in Canna × generalis(Canna Lily) 被引量:9
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作者 Rani Singh Arvind Kumar Dubey Indraneel Sanyal 《Horticultural Plant Journal》 SCIE 2019年第1期39-46,共8页
Canna being ornamental plants has a significant role in agriculture, medical, economy and food industry. Canna has a limited vase life due to the rapid loss of moisture from its perianth. For improving its market valu... Canna being ornamental plants has a significant role in agriculture, medical, economy and food industry. Canna has a limited vase life due to the rapid loss of moisture from its perianth. For improving its market value, cuticularisation of the perianth can be achieved by the expression of a heterologous cutin producing gene, using the tissue culture and transformation protocol developed in this study. Efficient, rapid and direct adventitious shoot regeneration was successfully established in Canna × generalis using recalcitrant rhizome explants. The explants were cultured on MS medium supplemented with 6-benzylaminopurine(6-BA), thidiazuron(TDZ), and kinetin. Among the four genotypes taken for tissue culture, the ‘Trinacria variegata' was the best responding cultivar. And 2 mg · L^(-1)6-BA or 1.5 mg · L^(-1) TDZ along with 0.1 mg · L^(-1) IAA was optimum for their regeneration. The highest regeneration was achieved in ‘Trinacria variegata'(36%) on 6-BA, 33% on TDZ while kinetin failed to evoke any regenerative responses. Regeneration was enhanced by supplementation of 100 mg · L^(-1) ascorbic acid(AsA), while, 100 mg · L^(-1) of l-cysteine or 100 mg · L^(-1) dithiothreitol(DTT), inhibited regeneration. Shoots were observed to develop 3–5 fibrous roots on MS medium supplemented with 0.5 mg · L^(-1) indole-3-butyric acid(IBA). The plantlets were transplanted into pots and acclimatised in glasshouse with 100%survival. For transformation of Canna, rhizome explants were co-cultivated for 60 min in Agrobacterium suspension. The explants were washed with 500 mg · L^(-1) cefotaxime solution, subjected to 100 mg · L^(-1) kanamycin selection followed by excision of the shoots and culturing them on IBA-supplemented media for root development. Transgene integration in the putative transformants was confirmed by PCR assay and copy number by Southern blot hybridisation analysis. 展开更多
关键词 Canna regeneration RHIZOME UIDA AGROBACTERIUM transformation ascorbic acid 6-BA TDZ
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Synergistic effects of tea polyphenols and ascorbic acid on human lung adenocarcinoma SPC-A-1 cells 被引量:11
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作者 Wei LI Jian-xiang WU You-ying TU 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2010年第6期458-464,共7页
Tea polyphenols have been shown to have anticancer activity in many studies.In the present study,we investigated effects of theaflavin-3-3'-digallate(TF3),one of the major theaflavin monomers in black tea,in combi... Tea polyphenols have been shown to have anticancer activity in many studies.In the present study,we investigated effects of theaflavin-3-3'-digallate(TF3),one of the major theaflavin monomers in black tea,in combination with ascorbic acid(AA),a reducing agent,and(-)-epigallocatechin-3-gallate(EGCG),the main polyphenol presented in green tea,in combination with AA on cellular viability and cell cycles of the human lung adenocarcinoma SPC-A-1 cells.The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) assay showed that the 50% inhibition concentrations(IC50) of TF3,EGCG,and AA on SPC-A-1 cells were 4.78,4.90,and 30.62 μmol/L,respectively.The inhibitory rates of TF3 combined with AA(TF3+AA) and EGCG combined with AA(EGCG+AA) at a molar ratio of 1:6 on SPC-A-1 cells were 54.4% and 45.5%,respectively.Flow cytometry analysis showed that TF3+AA and EGCG+AA obviously increased the cell population in the G0/G1 phase of the SPC-A-1 cell cycle from 53.9% to 62.8% and 60.0%,respectively.TF3-treated cells exhibited 65.3% of the G0/G1 phase at the concentration of its IC50.Therefore,TF3+AA and EGCG+AA had synergistic inhibition effects on the proliferation of SPC-A-1 cells,and significantly held SPC-A-1 cells in G0/G1 phase.The results suggest that the combination of TF3 with AA or EGCG with AA enhances their anticancer activity. 展开更多
关键词 Theaflavin-3-3'-digallate(TF3) (-)-epigallocatechin-3-gallate(EGCG) ascorbic acid(AA) Synergism SPC-A-1 cells Cell cycle
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A Multiwall Carbon Nanotube-chitosan Modified Electrode for Selective Detection of Dopamine in the Presence of Ascorbic Acid 被引量:6
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作者 LingYanJIANG ChuanYinLIU LiPingJIANG GuangHanLU 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第2期229-232,共4页
A novel multiwall carbon nanotube-chitosan modified electrode has been prepared.The modified electrode resolves the overlapping voltammetric response of dopamine and ascorbicacid into two well-defined peak by 212 mV. ... A novel multiwall carbon nanotube-chitosan modified electrode has been prepared.The modified electrode resolves the overlapping voltammetric response of dopamine and ascorbicacid into two well-defined peak by 212 mV. The mechanism of discrimination of dopamine fromascorbic acid is discussed. Dopamine can be determined selectively with the carbonnanotube-chitosan modified electrode. The electrode shows good sensitivity, selectivity andstability. 展开更多
关键词 Nanotube-chitosan modified electrode DOPAMINE ascorbic acid.
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Role of dissolved oxygen reduction in improvement inhibition performance of ascorbic acid during copper corrosion in 0.50 mol/L sulphuric acid 被引量:5
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作者 Mohammed A.Amin 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第3期341-345,共5页
The kinetics of dissolved O_2 reduction and hydrogen evolution reactions on copper surface was studied in naturally aerated and air and O_2-saturated 0.50 mol/L H_2SO_4 solutions using polarization measurements combin... The kinetics of dissolved O_2 reduction and hydrogen evolution reactions on copper surface was studied in naturally aerated and air and O_2-saturated 0.50 mol/L H_2SO_4 solutions using polarization measurements combined with the rotating disc electrode (RDE).The Koutecky-Levich plot indicated that the dissolved O_2 reduction at the copper electrode was an apparent four-electron process.A correlation between the presence of dissolved O_2 and the formation of Cu_2O,confirmed from XRD,was discussed. Ascorbic a... 展开更多
关键词 COPPER Sulphuric acid solutions Corrosion inhibition ascorbic acid RDE O_2 reduction
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The Protective Effect of Ascorbic Acid and Thiamine Supplementation against Damage Caused by Lead in the Testes of Mice 被引量:6
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作者 陕光 唐甜 张孝斌 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2009年第1期68-72,共5页
Lead is a ubiquitous environmental and industrial pollutant that may have toxic effects on the male. Vitamins may protect against toxic effects of lead in the liver and reproductive system, which is confirmed by our i... Lead is a ubiquitous environmental and industrial pollutant that may have toxic effects on the male. Vitamins may protect against toxic effects of lead in the liver and reproductive system, which is confirmed by our initial research. The aim of this study was to further investigate the protective effects of vitamins (ascorbic acid combined with thiamine) on lead acetate (Pb)-induced reproductive toxicities in mice and study the possible mechanisms underlying these effects. Forty-five male mice were randomly divided into 3 groups, 15 mice in each and received daily intragastric administration with control, Pb (20 mg/kg), and Pb+vitamins (ascorbic acid of 420 mg/kg+thiamine of 30 mg/kg) for 6 weeks, respectively. The Pb-treated animals showed significant decreases in the epididymal sperm count and motility compared to the control group, while the Pb+vitamins group had significant increases for these variables. Moreover, an increasing apoptosis of germinal cells induced by Pb was reduced by vitamin treatment. Pb induced the activation of Caspase-3, Fas/Fas-L and Bcl-2 with elevated levels, and the adaptor protein primarily regulated signaling through Fas and required for Fas-induced apoptosis. In conclusion, ascorbic acid combined with thiamine exhibited protective effect on reproductive system by inhibiting Pb-induced excessive cell apoptosis. 展开更多
关键词 LEAD ascorbic acid THIAMINE reproductive toxicity apoptosis
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Shape-controlled synthesis of highly monodisperse and small size gold nanoparticles 被引量:4
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作者 FU YunZhi DU YuKou +2 位作者 YANG Ping LI JinRu JIANG Long 《Science China Chemistry》 SCIE EI CAS 2007年第4期494-500,共7页
We describe here that fine control of nanoparticle shape and size can be achieved by systematic varia-tion of experimental parameters in the seeded growth procedure in aqueous solution. Cubic and spherical gold nanopa... We describe here that fine control of nanoparticle shape and size can be achieved by systematic varia-tion of experimental parameters in the seeded growth procedure in aqueous solution. Cubic and spherical gold nanoparticles are obtained respectively. In particularly, the Au cubes are highly mono-disperse in 33±2 nm diameter. The experimental methods involve the preparation of Au seed particles and the subsequent addition of an appropriate quantity of Au seed solution to the aqueous growth solutions containing desired quantities of CTAB and ascorbic acid (AA). Here, AA is a weak reducing agent and CTAB is not only a stable agent for nanoparticles but also an inductive agent for leading increase in the face of nanoparticle. Ultraviolet visible spectroscopy (UV-vis), X-ray diffraction (XRD), transmission electron microscopy (TEM) are used to characterize the nanoparticles. The results show that the different size gold nanoparticles displayed high size homogenous distribution and formed mono-membrane at the air/solid interface. 展开更多
关键词 Au CUBES SEED GROW up cetyltrimethylammoniumbromide (CTAB) ascorbic acid (AA)
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Preventive and Therapeutic Potential of Vitamin C in Mental Disorders 被引量:6
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作者 Qian-qian HAN Tian-tian SHEN +2 位作者 Fang WANG Peng-fei WU Jian-guo CHEN 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2018年第1期1-10,共10页
In this review,we summarize the involvement of vitamin C in mental disorders by presenting available evidence on its pharmacological effects in animal models as well as in clinical studies.Vitamin C,especially its red... In this review,we summarize the involvement of vitamin C in mental disorders by presenting available evidence on its pharmacological effects in animal models as well as in clinical studies.Vitamin C,especially its reduced form,has gained interest for its multiple functions in various tissues and organs,including central nervous system(CNS).Vitamin C protects the neuron against oxidative stress,alleviates inflammation,regulates the neurotransmission,affects neuronal development and controls epigenetic function.All of these processes are closely associated with psychopathology.In the past few decades,scientists have revealed that the deficiency of vitamin C may lead to motor deficit,cognitive impairment and aberrant behaviors,whereas supplement of vitamin C has a potential preventive and therapeutic effect on mental illness,such as major depressive disorder(MDD),schizophrenia,anxiety and Alzheimer's disease(AD).Although several studies support a possible role of vitamin C against mental disorders,more researches are essential to accelerate the knowledge and investigate the mechanism in this field. 展开更多
关键词 vitamin C ascorbic acid oxidative stress Alzheimer's disease major depressivedisorder
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Mechanism of Ascorbic Acid-induced Reversion Against Malignant Phenotype in Human Gastric Cancer Cells 被引量:5
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作者 YA-XUAN SUN QIU-SHENG ZHENC +2 位作者 GANG LI DE-AN GUO ZI-REN WANG 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2006年第5期385-391,共7页
Objective To find out the mechanisms of redifferentiation and reversion of malignant human gastric cancer cells induced by ascorbic acid. Methods Human gastric cancer cells grown in the laboratory were used. The Trypa... Objective To find out the mechanisms of redifferentiation and reversion of malignant human gastric cancer cells induced by ascorbic acid. Methods Human gastric cancer cells grown in the laboratory were used. The Trypan blue dye exclusion method was used to determine the cell doubling time. The electrophoresis rate and colonogenic potential were the indices used to measure the rate of redifferentiation. The content of malondialdehyde (MDA) was measured using the thiobarbituric acid (TBA) method. The activities of superoxide dismutase (SOD), catalase (CAT) and the content of H2O2 were evaluated by spectrophotography. Results Six mmol/L ascorbic acid was used as a positive control. Human gastric cancer cells were treated with 75 μm hydrogen peroxide, which alleviated many of the malignant characteristics. For example, the cell surface charge obviously decreased and the electrophoresis rate dropped from 2.21 to 1.10 pm·s^-1·cm^-1 The colonogenic potential, a measure of cell differentiation, decreased 90.2%. After treatment with ascorbic acid, there was a concentration- and time-dependent increase in hydrogen peroxide (H2O2) and the activity of superoxide dismutase (SOD). However, the activity of catalase (CAT) resulted in a concentration- and time-dependent decrease. SOD and 3-amino- 1,2,4-triazole (AT) exhibited some effects, but there were statistically significant differences between the SOD and AT group and the H2O2 group, Conclusions Ascurbic acid induces growth inhibition and redifferentiation of human gastric cancer cells through the production of hydrogen peroxide. 展开更多
关键词 Aminotriazole ascorbic acid CATALASE Gastric cancer Hydrogen peroxide REDIFFERENTIATION Superoxide dismutase
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Formation of a cerium conversion coating on magnesium alloy using ascorbic acid as additive.Characterisation and anticorrosive properties of the formed films 被引量:8
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作者 A.P.Loperena I.L.Lehr S.B.Saidman 《Journal of Magnesium and Alloys》 SCIE EI CAS 2016年第4期278-285,共8页
Cerium-based conversion coatings were formed on AZ91D magnesium alloy by immersion of the substrate in solutions containing Ce(NO_(3))_(3),H_(2)O_(2) and ascorbic acid(HAsc).The characterisation of the films was perfo... Cerium-based conversion coatings were formed on AZ91D magnesium alloy by immersion of the substrate in solutions containing Ce(NO_(3))_(3),H_(2)O_(2) and ascorbic acid(HAsc).The characterisation of the films was performed by electrochemical and surface analysis techniques such as SEM,EDS,X-ray diffraction and X-ray photoelectron spectroscopy(XPS).The degree of corrosion protection achieved was evaluated in simulated physiological solution by the open circuit potential monitoring,polarisation techniques and electrochemical impedance spectroscopy(EIS).The presence of HAsc in the conversion solution causes changes in the morphology,adherence and anticorrosive performance of the films.The improvement in the corrosion resistance is closely associated with the corrosion inhibition properties of HAsc. 展开更多
关键词 Cerium coatings AZ91D alloy ascorbic acid Anticorrosive properties
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Facile synthesis of enzyme functional metal-organic framework for colorimetric detecting H_2O_2 and ascorbic acid 被引量:5
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作者 Cunji Gao Hongmei Zhu +1 位作者 Jia Chen Hongdeng Qiu 《Chinese Chemical Letters》 SCIE CAS CSCD 2017年第5期1006-1012,共7页
In this work,a metal-organic frameworks material MIL-88 was prepared easily using solvent-thermal method,and was first found to have catalytic activities similar to those of biological enzymes such as catalase and per... In this work,a metal-organic frameworks material MIL-88 was prepared easily using solvent-thermal method,and was first found to have catalytic activities similar to those of biological enzymes such as catalase and peroxidase.The material was characterized by XRD,SEM,TEM,EDX,FT-IR techniques and an N2 adsorption method.It exhibited peroxidase-like activity through catalytic oxidation of the peroxidase substrate 3,3',5,5'-tetramethylbenzidine(TMB) in the presence of H2O2,producing a blue-colored solution.Under optimal conditions,the absorbance at 652 nm is linearly correlated with the concentration of H2O2 from 2.0×10^-6 mol/L to 2.03×10^-5 mol/L(R-2=0.981) with a detection limit of 5.62×10^-7 mol/L(S/N=3).More importantly,a sensitive and selective method for ascorbic acid detection was developed using this material as a catalyst.The analytical method for ascorbic acid detection was observed to have a linear range from 2.57×10^-6 mol/L to 1.01×10^-5 mol/L(R-2=0.989) with a detection limit of 1.03×10^-6 mol/L(S/N=3).This work suggests MOFs have advantages of preparing biomimetic catalysts and extends applications of the functional MOFs in the field of biosensor. 展开更多
关键词 Metal-organic frameworks Horseradish peroxidase H2O2 ascorbic acid Colorimetric detection Biomimetic catalyst
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Perioperative topical ascorbic acid for the prevention of phacoemulsification-related corneal endothelial damage:Two case reports and review of literature 被引量:5
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作者 Chia-Yi Lee Hung-Ta Chen +5 位作者 Yi-Jen Hsueh Hung-Chi Chen Chieh-Cheng Huang Yaa-Jyuhn James Meir Chao-Min Cheng Wei-Chi Wu 《World Journal of Clinical Cases》 SCIE 2019年第5期642-649,共8页
BACKGROUND The current case report describes successful phacoemulsification with the aid of perioperative topical ascorbic acid(AA) in two patients with corneal endothelial disorders to prevent postoperative corneal e... BACKGROUND The current case report describes successful phacoemulsification with the aid of perioperative topical ascorbic acid(AA) in two patients with corneal endothelial disorders to prevent postoperative corneal endothelial decompensation.CASE SUMMARY Two eyes of two patients underwent phacoemulsification with pre-existing corneal endothelial disorders including Fuchs corneal endothelial dystrophy(Patient 1) and endotheliitis(Patient 2). Topical AA was applied to both patients at least one month before and after with a frequency of four times per day. After the surgery, both eyes improved best-corrected visual acuity(BCVA) and there was limited human corneal endothelial cell loss without signs of corneal endothelial decompensation, such as deteriorated BCVA or persistent corneal edema during the follow-up of at least two years.CONCLUSION Perioperative administration of topical AA may be an alternative therapy to the triple procedure in patients expecting to undergo cataract surgery. 展开更多
关键词 ascorbic acid Fuchs CORNEAL ENDOTHELIAL DYSTROPHY Endotheliitis Human CORNEAL ENDOTHELIAL cell PHACOEMULSIFICATION Case report
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Enhancement of cardiomyocyte differentiation from human embryonic stem cells 被引量:5
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作者 WANG YanXia1,2,CHEN GuiAn1,2,SONG TianRan1,2,MAO GenHong1,2 & BAI HaiYan1,2 1Reproductive Medicine Center,Peking University Third Hospital,Beijing 100083,China 2Stem Cell Research Center,Peking University Third Hospital,Beijing 100083,China 《Science China(Life Sciences)》 SCIE CAS 2010年第5期581-589,共9页
Several approaches have been used to encourage the differentiation of cardiomyocytes from human embryonic stem cells.However,the differentiation efficiency is low,and appropriate culture protocols are needed to produc... Several approaches have been used to encourage the differentiation of cardiomyocytes from human embryonic stem cells.However,the differentiation efficiency is low,and appropriate culture protocols are needed to produce adequate numbers of cardiomyocytes for therapeutic cell transplantation.This study investigated the effects of serum on cardiomyocyte differentiation in suspension culture medium during embryoid body(EB) formation by human embryonic stem cells.The addition of ascorbic acid,dimethylsulfoxide and 5-aza-2'-deoxycytidine during days 5-7 at the EB-forming stage resulted in an increase in the numbers of rhythmically contracting clusters of derived cardiomyocytes.Treatment with 0.1 mmol L-1 ascorbic acid alone,or more notably in combination with 10 μmol L-1 5-aza-2'-deoxycytidine,induced the formation of beating cells within EBs.Most of the beating clusters had spontaneous contraction rates similar to those found in human adults,and their contractile ac-tivity lasted for up to 194 days. 展开更多
关键词 human EMBRYONIC stem cells CARDIOMYOCYTE DIFFERENTIATION SERUM ascorbic ACID 5-AZA-DC
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Switch-on fluorescence sensor for ascorbic acid detection based on MoS2 quantum dots-MnO2 nanosheets system and its application in fruit samples 被引量:5
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作者 Ya-Li Xu Xiao-Ying Niu +2 位作者 Hong-Li Chen Sheng-Guo Zhao Xing-Guo Chen 《Chinese Chemical Letters》 SCIE CAS CSCD 2017年第2期338-344,共7页
In this work,molybdenum disulfide quantum dots(MoS2 QDs) were firstly prepared by hydrothermal method using sodium molybdate and glutathione as precursors,and applied in ascorbic acid detection.When joining MnO2 nan... In this work,molybdenum disulfide quantum dots(MoS2 QDs) were firstly prepared by hydrothermal method using sodium molybdate and glutathione as precursors,and applied in ascorbic acid detection.When joining MnO2 nanosheets into MoS2 QDs solution,they produced an obvious fluorescence quenching,which should be due to inner filter effect(IFE).Meanwhile,the fluorescent probe was formed,Interestingly,we found that this quenching phenomenon disappeared with the addition of ascorbic acid,In other words,the fluorescence gradually restored.This recovery phenomenon is mainly due to the reduction effect of ascorbic acid for MnO2 nanosheets.Under the optimum conditions,the limit of detection(LOD) of 39 nmol/L for ascorbic acid was achieved with a linear range of 0.33-5.00 μmol/L.The repeatability was better than 5.0% for ascorbic acid in both standard and fruit samples(n = 3).Moreover,the as-fabricated fluorescent sensing system was successfully employed to detect the ascorbic acid levels in hawthorn and jujube with satisfactory results. 展开更多
关键词 MoS2 QDs MnO2 nanosheets ascorbic acid "Switch-on" fluorescence sensor Fruit samples
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Effects ofβ-1,3-glucan and ascorbic acid on the nutritional-immune response and antioxidant signaling pathways of live tiger grouper during simulated transport 被引量:1
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作者 Bo Wu Zhenkun Xu +3 位作者 Jie Cao Qi Wang Jun Mei Jing Xie 《Aquaculture and Fisheries》 CSCD 2024年第2期265-272,共8页
Transport in water is the most common method for transporting live fish in China,however,transport is a strong stressor.Transport stress could lead to a reduced immune and antioxidant system function of tiger grouper,... Transport in water is the most common method for transporting live fish in China,however,transport is a strong stressor.Transport stress could lead to a reduced immune and antioxidant system function of tiger grouper,resulting in sickness and death.Besides,tiger grouper were continuously stressed during transport,which resulted in quality deterioration.It is necessary that find a way to relieve the stress of transportation of tiger grouper.Ascorbic acid is not only a good anti-stress agent,but it is also an effective immunostimulant.β-1,3-glucan is a feed additive that can enhance the immune response of fish.Therefore,this study evaluated the effects ofβ-1,3-glucan and ascorbic acid on the nutritional-immune response and antioxidant signaling pathways of live tiger grouper during simulated transport.Results indicated that addingβ-1,3-glucan and ascorbic acid in transport-water muted the increase of alanine aminotransferase(ALT)and aspartate aminotransferase(AST)activity.In addition,β-1,3-glucan and ascorbic acid activated Nrf2 and mediated TOR expression and then up-regulate related mRNA expression of antioxidant and immune enzymes.We concluded that the application ofβ-1,3-glucan and ascorbic acid inhibit the increase of metabolism enzymes and inflammatory factors and activate immune and antioxidant signaling pathways to relieve oxidant stress,immune response,and apoptosis.Reducing the loss of amino acids provided nutrients to relieve oxidative stress and immune response,which demonstrated immune-nutritional response in live tiger grouper during simulated transport.These results may provide a new solution for alleviating the decline of immune and antioxidant function of tiger grouper caused by transportation stress. 展开更多
关键词 Tiger grouper β-1 3-Glucan ascorbic acid Immune response Antioxidant signaling pathway
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Prevalence of Iron Deficiency and Iron Deficiency Anemia in Infants and Children and Treatment with Microencapsulated Iron II Fumarate and Supplied Ascorbic Acid as “Sprinkles” 被引量:4
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作者 Abdullah Al-Mamari Mohammad A. Al-Hegami +7 位作者 Sadeq Al-Hag Mahmoud Al-Buryhi Safa Al-Amawi Leena Ahmed Lila Al-Awadi Sarah Al-Jamal Wafa Mohammad Yasmin Mohammad 《Pharmacology & Pharmacy》 2014年第7期716-724,共9页
Background: Iron deficiency anemia (IDA) in children and infants is a common nutritional problem all over the world. Infants and young children have a high risk for developing iron deficiency (ID) because they have hi... Background: Iron deficiency anemia (IDA) in children and infants is a common nutritional problem all over the world. Infants and young children have a high risk for developing iron deficiency (ID) because they have high demand for iron during the period of rapid growth. This is aggravated by the insufficiency of iron in their diet. Iron supplementation programs using pediatric tablets or drops have not been successful in the control of anemia amongst infants and children in some countries. “Sprinkles” is an innovative multi-micronutrient home fortification strategy to control iron deficiency and anemia to be more useful. Objective: The objective was to estimate the prevalence ID and IDA in infants and children in Ibb City, Yemen Republic;evaluate the use of a new form of iron and determine the hematologic response to different doses and forms of iron in Sprinkles and iron drops. Design: Using a prospective, randomized, controlled design, we studied 337 randomly children aged 24 - 48 months and infants aged 6 - 24 months in Ibb City (hemoglobin: 70 - 99 g/L). One group received a daily sachet of microencapsulated ferrous fumarate (80 mg elemental Fe) in powder form plus ascorbic acid to be sprinkled onto any complementary food eaten (sprinkles group);a control group received ferrous sulfate drops 3 times/d for 2 months (total dose: 40 mg elemental Fe). Hemoglobin and serum ferritin concentrations were measured at baseline and at the end of treatment. Results: Successful treatment of anemia (hemoglobin > 100 g/L) occurred in 58% of the sprinkles group and in 56% of the drops group, with minimal side effects in both groups. Geometric mean ferritin concentrations increased significantly in each group from baseline to the end of treatment (P Conclusion: Use of ferrous sulfate drops or a single daily dose of microencapsulated ferrous fumarate sprinkles plus ascorbicacid resulted in a similar rate of successful treatment of anemia without side effects. To our knowledge, this is the first demonstration of the use of 展开更多
关键词 INFANTS Children ANEMIA Microencapsulated IRON ascorbic Acid
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