期刊文献+
共找到1,148篇文章
< 1 2 58 >
每页显示 20 50 100
Changes of total antioxidant capacity and total oxidant status of aqueous humor in diabetes patients and correlations with diabetic retinopathy 被引量:4
1
作者 Emrullah Beyazyildiz Ali Bülent ankaya +6 位作者 Esra Ergan Mustafa Alparslan Anayol Yasemin zdamar Sevilay Sezer Mehmet Hakan Tirhis Pelin Yilmazbas Faruk ztürk 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2013年第4期531-536,共6页
AIM:To measure changes of total oxidant status(TOS)and total antioxidant capacity(TAC) of aqueous humor(AH) in diabetic retinopathy(DR) patients,and to determine if there were any differences in TOS and TAC of AH in d... AIM:To measure changes of total oxidant status(TOS)and total antioxidant capacity(TAC) of aqueous humor(AH) in diabetic retinopathy(DR) patients,and to determine if there were any differences in TOS and TAC of AH in diabetic patients without retinopathy compared with non-diabetic patients.·METHODS:One hundred and three eyes of 103patients who were enrolled for cataract surgery were included in this study.Patients were grouped according to presence of diabetes and stage of DR.Prior to cataract surgery,0.1mL to 0.2mL of AH was aspirated and analyzed for TAC and TOS level using a colorimetric method.·RESULTS:TOS levels were highest among proliferative diabetic retinopathy(PDR) patients and lowest in patients with only cataracts.Results were statistically significant between all groups(P 【0.05).Whereas result between diabetic without retinopathy patients and non-proliferative diabetic retinopathy(NPDR) patients was not statistically significant(P =0.757).TAC levels were highest in patients with only cataract and lowest among PDR patients and results were statistically significant between all groups(P 【0.05).·CONCLUSION:Aqueous humor TAC levels are low in diabetic patients and reduced further in DR patients,TOS levels are increased in diabetic patients and this is exacerbated in DR patients. 展开更多
关键词 aqueous humor diabetic retinopathy total antioxidant capacity total oxidant status
下载PDF
Patients with primary biliary cirrhosis have increased serum total antioxidant capacity measured with the crocin bleaching assay 被引量:14
2
作者 George Notas Niki Miliaraki +5 位作者 Marilena Kampa Fillipos Dimoulios Erminia Matrella Adam Hatzidakis Elias Castanas Elias Kouroumalis 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第27期4194-4198,共5页
AIM: The balance between oxidants and antioxidants can play an important role in the initiation and development of liver diseases. Recently, we have described a new automated method for the determination of total ant... AIM: The balance between oxidants and antioxidants can play an important role in the initiation and development of liver diseases. Recently, we have described a new automated method for the determination of total antioxidant capacity (TAC) in human serum and plasma.METHODS: We measured TAC and corrected TAC (CTACabstraction of interactions due to endogenous uric acid,bilirubin and albumin) in 52 patients with chronic liver diseases (41 patients with primary biliary cirrhosis (PBC),10 patients with chronic hepatitis C and 13 patients with viral HCV cirrhosis) as well as in 10 healthy controls. In 23 PBC patients measurement were also done 6 mo after treatment with ursodeoxycholic acid (UDCA). The TAC assay was based on a modification of the crocin bleaching assay. The results were correlated with routine laboratory measurements and the histological stage of PBC.RESULTS: There were no significant differences in TAC between the various groups. However, CTAC was considerably increased in the PBC group compared to controls and cirrhotics. Analysis of these patients according to disease stages showed that this increase was an early phenomenon observed only in stages I and II compared to controls, cirrhotics and patients with chronic hepatitis C).After 6 mo of treatment with UDCA, levels of CTAC decreased to those similar to that of controls.CONCLUSION: Patients in the early stages of PBC present with high levels of corrected total antioxidant capacity and this maybe related to the pathophysiology of the disease. UDCA treatment restores the levels of CTAC to control levels. 展开更多
关键词 ANTIOXIDANTS Serum total antioxidant capacity Primary biliary cirrhosis Chronic hepatitis C Viral HCVcirrhosis Ursodeoxycholic acid
下载PDF
The effect of fitness level on cardiac autonomic regulation, IL-6,total antioxidant capacity, and muscle damage responses to a single bout of high-intensity interval training 被引量:2
3
作者 Lukas Cipryan 《Journal of Sport and Health Science》 SCIE 2018年第3期363-371,共9页
Purpose:The aim of this study was to investigate the influence of the cardiorespiratory fitness level on the response to high-intensity interval training(HIIT)with an individually adjusted running speed of the same re... Purpose:The aim of this study was to investigate the influence of the cardiorespiratory fitness level on the response to high-intensity interval training(HIIT)with an individually adjusted running speed of the same relative intensity.The evaluation focused on acute cardiorespiratory response,postexercise cardiac autonomic modulation(heart rate variability(HRV))and biochemical markers of inflammation,oxidative stress,and muscle damage.Methods:Thirty participants were divided into 3 subgroups:well trained,moderately trained,and untrained.All the participants performed30 min HIIT composed of 6×2 min interval exercise with work-to-relief ratio=1 and work intensity 100%of individual velocity at maximal oxygen consumption(VO2max).Acute cardiorespiratory variables,postexercise HRV,lactate,interleukin-6(IL-6),total antioxidant capacity(TAC),creatine kinase,and myoglobin up to 4h after HIIT were monitored.Results:The differences in relatively expressed cardiorespiratory variables(heart rate,VO2)during HIIT were at most moderate,with the most pronounced between-group differences in absolute VO2 values.The disruption of the postexercise HRV was the most pronounced in untrained individuals,and this difference persisted 1 h after HIIT.The highest postexercise IL-6 and TAC concentrations and the lowest changes in creatine kinase and myoglobin were revealed in well-trained individuals.Conclusion:The higher fitness level was associated with the less pronounced postexercise cardiac autonomic changes and their faster restoration,even when there were similar acute cardiorespiratory responses.These findings were simultaneously accompanied by the higher postexercise IL-6 and TAC concentrations and less significant changes in muscle damage biochemical markers in well-trained individuals. 展开更多
关键词 CREATINE KINASE Heart rate variability Inflammation MYOGLOBIN total ANTIOXIDANT capacity Training status
下载PDF
Dynamic Analysis of Nitric Oxide and Total Oxidant Capacity in Cow Uterine Secretion with Subclinical Endometritis
4
作者 Song Xue Li De-jun +2 位作者 Feng Guo-feng Li Bei Liu Yun-feng 《Journal of Northeast Agricultural University(English Edition)》 CAS 2015年第1期35-39,共5页
Subclinical endometritis is a physiological inflammation that serves to clear persistent contaminants from the uterus. To investigate the alteration of antioxidant, such as vitamin E(VE) and vitamin C(VC), total o... Subclinical endometritis is a physiological inflammation that serves to clear persistent contaminants from the uterus. To investigate the alteration of antioxidant, such as vitamin E(VE) and vitamin C(VC), total oxidant capacity(TOC) and nitric oxide(NO) in cows with normal and subclinical endometritis(SCE), we examined the concentrations of NO, VC and VE, TOC and polymorphonuclear neutrophils(PMN) percentage in uterine secretion. The cows were divided into two groups, normal(n=20) and subclinical endometritis(SCE, n=60), based on endometrial cytology(presence of PMN≥5%). Uterine secretion and blood were collected as described previously. Griess reaction was used to determine the concentration of NO. The concentrations of TOC, VC and VE were detected by a commercially available assay kit. The results showed that the concentrations of NO, TOC and PMN percentage were significantly higher(P〈0.01, P〈0.05, and P〈0.01, respectively) in uterine secretion with SCE compared to those from normal; however, the levels of VC and VE were significantly lesser(P〈0.01). In conclusion, the concentrations of NO, TOC, VC, VE and PMN percentage differed between normal and SCE cows. Meanwhile, the relationship between the concentration of NO and PMN percentage from uterine secretion in cows with subclinical endometritis were positively correlated. Consequently, these alterations in NO, TOC, VC, VE levels and PMN percentage contributed to as a diagnostic index of the uterine inflammation, with the aim to increase the reproduction of the cows and the decrease economic losses. 展开更多
关键词 COW subclinical endometritis nitric oxide antioxidant total oxidant capacity
下载PDF
A Novel Assay for Measuring Total Antioxidant Capacity in Whole Blood and Other Biological Samples
5
作者 Riccardo Ciuti Gianfranco Liguri 《Journal of Biomedical Science and Engineering》 2017年第2期60-76,共17页
A new method for rapidly determining total antioxidant capacity (TAC) in a biological sample has been devised and evaluated. A surfactant present in the reagent causes the lysis of cells in the sample. Glutathione, as... A new method for rapidly determining total antioxidant capacity (TAC) in a biological sample has been devised and evaluated. A surfactant present in the reagent causes the lysis of cells in the sample. Glutathione, ascorbic acid, protein thiols and other main reducing substances in the sample react with a specific redox chromogen (2,6-dichlorophenolindophenol) and produce a change in the color of the reagent, which is determined photometrically at 630 nm. This new method quantifies the overall capacity of the sample to reduce a redox chromogen and it requires the minimum volumes and time. The assay can be used on a wide variety of biological samples including whole blood, serum, plasma, tissue extracts and homogenates, food, wine, fruit juice and other beverages. Results are expressed in terms of mmol/L glutathione equivalents. TAC can be assayed manually, on automatic analyzers or micro-plate readers. 展开更多
关键词 total ANTIOXIDANT capacity Free RADICALS total ANTIOXIDANT Status OXIDATIVE Stress INTRACELLULAR TAC
下载PDF
Variability in total antioxidant capacity, antioxidant leaf pigments and foliage yield of vegetable amaranth
6
作者 Umakanta Sarker Md Tofazzal Islam +1 位作者 Md Golam Rabbani Shinya Oba 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2018年第5期1145-1153,共9页
Twenty vegetable amaranth genotypes were evaluated for total antioxidant capacity, antioxidant leaf pigments, vitamins, and selection of suitable genotypes for extraction of juice in a randomized complete block design... Twenty vegetable amaranth genotypes were evaluated for total antioxidant capacity, antioxidant leaf pigments, vitamins, and selection of suitable genotypes for extraction of juice in a randomized complete block design(RCBD) with three replications. Vegetable amaranth was rich in chlorophyll, β-cyanins, β-xanthins, betalains, carotene, ascorbic acid and total antioxidant. The genotypes VA14, VA16, VA18, VA15, and VA20 could be selected as amaranth vegtable varieties with high yields and abundance antioxidant leaf pigments and vitamins to produce juice. The genotypes VA13 and VA19 had above-average foliage yield and high antioxidant profiles while the genotypes VA2, VA3, VA9, VA11, VA12, and VA17 had a high antioxidant profiles and below-average foliage yield. These genotypes could be used as a donor parent for integration of potential high antioxidant profiles genes into other genotypes. The correlation study revealed a strong positive association among all the antioxidant leaf pigments, total antioxidant capacity and foliage yield. Selection based on total antioxidant capacity, antioxidant leaf pigments could economically viable to improve the yield potential of vegetable amaranth genotypes. Total carotene and ascorbic acid exhibited insignificant genotypic correlation with all the traits except total antioxidant capacity. This indicates that selection for antioxidant vitamins might be possible without compromising yield loss. 展开更多
关键词 ascorbic acid betalain carotene chlorophyll β-cyanins β-xanthins total antioxidant capacity foliage yield correlation
下载PDF
The Role of C-Reactive Protein, Granulocyte Colony Stimulating Factor and Total Antioxidant Capacity in Diagnosis of Acute Appendicitis
7
作者 Barış Sevinç Ahmet Okuş +2 位作者 Serden Ay Nergis Aksoy Recep Demirgül 《Surgical Science》 2016年第3期177-180,共4页
Background and Aim: Despite the fact that acute appendicitis is the most common surgical emergency all around the world, its diagnosis is still based on clinical evaluation and accuracy of the diagnosis depending on e... Background and Aim: Despite the fact that acute appendicitis is the most common surgical emergency all around the world, its diagnosis is still based on clinical evaluation and accuracy of the diagnosis depending on experience. The aim of this study is to evaluate the role of inflammatory markers in diagnosis of acute appendicitis. Material and Method: The study includes 77 cases with histopathologically proven acute appendicitis and 17 control cases. Blood samples were obtained from all cases and C-reactive protein (CRP), Granulocyte Colony Stimulating Factor (G-CSF) and Total Antioxidant Capacity (TAC) were measured. Findings: In cases with acute appendicitis, CRP and G-CSF levels were found to be related to acute appendicitis;however, TAC was not affected by the disease process. Moreover, CRP and G-CSF levels were correlated with the disease severity. Conclusion: Both CRP and G-CSF can be used in diagnosis of acute appendicitis. Furthermore, increased CRP level can be a marker to show advanced cases. However, G-CSF is not an effective marker to show disease severity. 展开更多
关键词 Acute Appendicitis C-Reactive Protein Granulocyte Colony Stimulating Factor total Anti-Oxidant capacity
下载PDF
Effect of Colchicine on Total Antioxidant Capacity,Antioxidant Enzymes and Oxidative Stress Markers in Patients with Knee Osteoarthritis
8
作者 Metin Erden Levent Ediz +4 位作者 Ozcan Hiz Yasin Tuluce Halil Ozkol Murat Toprak Fahrettin Demirdag 《International Journal of Clinical Medicine》 2012年第5期377-382,共6页
Background/Aim: We aimed to investigate the effects of colchicine on clinical recovery, as well as oxidative stress markers and total antioxidant capacity (TAC) in whole blood of patients with knee osteoarthritis (OA)... Background/Aim: We aimed to investigate the effects of colchicine on clinical recovery, as well as oxidative stress markers and total antioxidant capacity (TAC) in whole blood of patients with knee osteoarthritis (OA). Materials and methods: Sixty patients with grade 2 - 3 knee OA according to ACR knee OA criteria whom examination of the knee joint synovial fluid by polarized light microscopy demonstrated CPDD crystals existence were included in the study. Fifty healthy subjects were included as a control group. Patients were divided randomly into two groups. The first group (paracetamol group) was given only paracetamol 3 gr daily p.o and the second group (colchicine and paracetamol group) was given colchicine 1,5 gr and paracetamol 3 gr daily p.o for six months. For outcome measures WOMAC and VAS were used. Superoxide dismutase (SOD), Catalase (CAT) ezyme activities and Glutathione (GSH) and Malondialdehyde (MDA) levels and TAC all were measured. Results: WOMAC scores were improved in both patient groups compared with pre-treatment evaluation (p 0.05). TAC was signifcantly increased only in colchicine/paracetamol group. Oxidant parameter MDA levels were significantly decreased in both paracetamol group and colchicine/paracetamol group. CAT, SOD enzyme activities and GSH levels did not change before and after treatment protocols in both patient groups. Conclusion: Both paracetamol 3000 mg/day and 3000 mg paracetamol plus 1,5 gr/day colchicine is effective in the treatment of patients with knee osteoarthritis. But the addition of colchicine to paracetamol produced significantly greater symptomatic benefit than paracetamol alone. Our study also showed that colchicine lowers whole blood MDA which is a lipid peroxidation compound and elevates TAC levels in patients with knee OA. This may show probable disease modifying effect of colchicine in knee OA which require further long period laboratory and radiologic investigations. 展开更多
关键词 Knee Osteoarthritis COLCHICINE PARACETAMOL total Antioxidant capacity MALONDIALDEHYDE Oxidative Stres
下载PDF
Atmospheric Environmental Capacity of S_2 in Winter over Lanzhou in China:A Case Study 被引量:9
9
作者 安兴琴 左洪超 陈丽娟 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2007年第4期688-699,共12页
The total emission control method based on atmospheric environmental capacity is the most effective in air pollution mitigation. The atmospheric environmental capacities of SO2 on representative days over Lanzhou are ... The total emission control method based on atmospheric environmental capacity is the most effective in air pollution mitigation. The atmospheric environmental capacities of SO2 on representative days over Lanzhou are estimated using the numerical models RAMS, HYPACT and a linear programming model, according to the national ambient air quality standard of China (NAAQSCHN). The results show that the fields of meteorological elements and SO2 simulated by the models agree reasonably well with observations. The atmospheric environmental capacity of SO2 over Lanzhou is around 111.7 × 10^3 kg d^-1, and in order to meet the air quality level Ⅱ of the NAAQSCHN, SO2 emissions need to be reduced by 20%. 展开更多
关键词 air pollution total emission control method atmospheric environmental capacity air quality standard numerical simulation
下载PDF
ON REGIONAL DIFFERENTIATION OF RIVER WATER ENVIRONMENT CAPACITY AND STRATEGIES TO CONTROL WATER ENVIRONMENT POLLUTION IN CHINA 被引量:4
10
作者 王华东 王淑华 +1 位作者 鲍全盛 祁忠 《Chinese Geographical Science》 SCIE CSCD 1995年第2期116-124,共9页
China has large population and wide territory, the natural conditions of different regions are complicated. water resources are distributed unbalanced.economic developing states are unequal. For these reasons the vari... China has large population and wide territory, the natural conditions of different regions are complicated. water resources are distributed unbalanced.economic developing states are unequal. For these reasons the variation of concerned water environment capacity has obvious character of regional differentiation. In this paper, from the economic development point of view, the regular pattern of regional differentiation of China's water environment capacity resources is analyzed. the concept of contradictory degree between water environment capacity and economic development is introduced, based on them, rivers in China are divided into three regions, and corresponding strategies to control water pollution are advanced. The aims are to use river water environment capacity resources effectively. to control pollution and to improve environmental quality. 展开更多
关键词 WATER ENVIRONMENT capacity. REGIONAL differentiation. pollutioncontrol total quantity CONTROL
下载PDF
Effects of Heat Treatment on Flavonoids Content and Antioxidant Capacity of Buckwheat (Fagopyrum tataricum Gaert) Flour Ethanolic Extracts 被引量:4
11
作者 ZHONGGeng RomeoTToledo CHENZong-dao 《Agricultural Sciences in China》 CAS CSCD 2003年第9期1035-1040,共6页
The chemical composition, total flavonoids and antioxidant capacity of 50% ethanolic extracts from raw and cooked buckwheat flour from southwest of China were determined. The heat treatment used to gelatinize the flou... The chemical composition, total flavonoids and antioxidant capacity of 50% ethanolic extracts from raw and cooked buckwheat flour from southwest of China were determined. The heat treatment used to gelatinize the flour starch significantly reduced the total flavonoids in the extract from 83.52 to 67.36 mg 100 g 1 of dry matter in the raw and cooked flour, respectively. The antioxidant capacity of the extracts was evaluated using autooxidation in a β carotene linoleate model system (AA or AAC), DPPH radical scavenging assay (IP) and oxygen radical absorbance capacity (ORAC) assay. Values for raw buckwheat flour extract were 97.84, 874.31, 76.45 and 94.92% for AA, AAC, ORAC and IP, respectively, while values in cooked buckwheat flour were 86.14, 842.88, 63.93 and 94.74% for AA, AAC, ORAC and IP, respectively. Values before cooked and raw buckwheat flour extracts were significantly different ( P <0.05) for AA, AAC, and ORAC. 展开更多
关键词 Buckwheat flour ( Fagopyrum tataricum Gaert) total flavonoids Antioxidant capacity
下载PDF
Volatile components,total phenolic compounds,and antioxidant capacities of worm-infected Gomphidius rutilus 被引量:3
12
作者 Libin Sun Wei He +6 位作者 Guang Xin Pengju Cai Yin Zhang Zhiyong Zhang Yunyun Wei Bingxin Sun Xiaowen Wen 《Food Science and Human Wellness》 SCIE 2018年第2期148-155,共8页
This study evaluated the effects of worm infection on the volatile components,total phenolic compounds,and antioxidant capacities of Gomphidius rutilus.G.rutilus without worms(GW),G.rutilus infected by a small amount ... This study evaluated the effects of worm infection on the volatile components,total phenolic compounds,and antioxidant capacities of Gomphidius rutilus.G.rutilus without worms(GW),G.rutilus infected by a small amount of worms(GS;infected area<50%),and G.rutilus infected by a large amount of worms(GL;infected area>50%)were investigated.The volatile components of G.rutilus were analyzed by simultaneous distillation–extraction(SDE)and headspace solid-phase microextraction(HS-SPME)using gas chromatography–mass spectrometry(GC–MS).A total of 17 and 19 types of volatile compounds were detected,including ketones,alcohols,benzene,alkenes,aldehydes,esters,acids,and alkanes.Alcohols comprised the most abundant compound in GL,GS,and GW.The relative content of 1-octen-3-ol was the highest in all mushrooms.The concentration of eight-carbon(C8)compounds relative to the total volatile compounds varied widely,ranging from 40%(GW)to 64.34%(GS)and 84.42%(GS)and to 91.59%(GL),respectively,among the three samples.The antioxidant capability and the total phenolic contents of G.rutilus were evaluated in this study.The highest total phenolic content(TPC)of 192.23 mg GAE/g was found in GL,which differed significantly(P<0.05)from the latter two samples,whereas the lowest value of 156.11 mg GAE/g was found in GW.ABTS radical cation scavenging activity,FRAP ferric reducing antioxidant capacity(FRAP)radical scavenging activity,and oxygen radical absorbance capacity(ORAC)were investigated to screen the antioxidant properties of extracts.The contents of total phenolic compounds and their antioxidant capacities in vitro showed significant correlations(P<0.01).Among the three types of samples,the phenolic compounds of GL exhibited the highest antioxidant capacity,showing the values of 0.089 mM TE/g for ABTS,0.949 mM Fe^2+E/g for FRAP,and 1.952 M TE/g for ORAC.However,regarding the total antioxidant capacity,GS exhibited the highest antioxidant capacity,showing the values of 0.002648 mM TE/g for ABTS,0.004437 mM Fe^2+E/g for FRAP,and 0.256μM TE/g for ORAC.In conclusion,HS-SPME was more suitable for the extraction of volatile aroma components from G.rutilus.GL had the most abundant aroma components.GL had the highest TPC and antioxidant capacity compared with those of GS and GW,whereas GS showed the opposite results.Interestingly,GS was found to have the highest total antioxidant capacity in vitro.Based on these measured indicators,worm infection had no negative effect on the quality of G.rutilus.Therefore,worm-infected G.rutilus can also be consumed by humans. 展开更多
关键词 Gomphidius rutilus Worm infection Volatile components total phenolic Antioxidant capacity
下载PDF
Quantification of phenolic compounds and antioxidant capacity of an underutilized Indian fruit:Rayan[Manilkara hexandra(Roxb.)Dubard] 被引量:1
13
作者 Bhumi Parikh V.H.Patel 《Food Science and Human Wellness》 SCIE 2017年第1期10-19,共10页
The fruit of Manilkara hexandra(Roxb.)Dubard is one of the most underutilized fruits of India and in Gujarat state.It is popularly known as‘Rayan’.The fruit and seed of Rayan were analysed for their total phenolic a... The fruit of Manilkara hexandra(Roxb.)Dubard is one of the most underutilized fruits of India and in Gujarat state.It is popularly known as‘Rayan’.The fruit and seed of Rayan were analysed for their total phenolic and flavonoid content,phenolic compounds and total antioxidant capacity with six different assay methods.The results indicated that the methanolic extract of Rayan fruit being a good source of phenolic(811.3 mg GAE/100 g fw)and flavonoid(485.56 mg RE/100 g fw)content.Also,eleven known phenolic compounds were tentatively identified for the first time from the fruit and seed of Rayan.The LC–MS/MS analysis of fruit revealed the presence of major phenolic compounds such as gallic acid,quercetin and kaempferol,while quercetin,gallic acid and vanillic acid in seed.The presence of quercetin suggests health benefits.The fruit of Rayan was also proved to be a better source of antioxidants as measured by FRAP,RPA,DPPHRSA,ABTSRSA and HRSA except NORSA in comparison with that of seed.The current study explains that M.hexandra is a relatively good source of antioxidants such as phenols and flavonoids for diet. 展开更多
关键词 Manilkara hexandra(Roxb.)Dubard Underutilized fruit High performance liquid chromatography–mass spectrometry Phenolic compounds total antioxidant capacity
下载PDF
Ultimate Bending Capacity of Strain Hardening Steel Pipes
14
作者 陈严飞 张娟 +3 位作者 张宏 李昕 周晶 曹静 《China Ocean Engineering》 SCIE EI CSCD 2016年第2期231-241,共11页
Based on Hencky's total strain theory of plasticity,ultimate bending capacity of steel pipes can be determined analytically assuming an elastic-linear strain hardening material,the simplified analytical solution is p... Based on Hencky's total strain theory of plasticity,ultimate bending capacity of steel pipes can be determined analytically assuming an elastic-linear strain hardening material,the simplified analytical solution is proposed as well.Good agreement is observed when ultimate bending capacities obtained from analytical solutions are compared with experimental results from full-size tests of steel pipes.Parametric study conducted as part of this paper indicates that the strain hardening effect has significant influence on the ultimate bending capacity of steel pipes.It is shown that pipe considering strain hardening yields higher bending capacity than that of pipe assumed as elastic-perfectly plastic material.Thus,the ignorance of strain hardening effect,as commonly assumed in current codes,may underestimate the ultimate bending capacity of steel pipes.The solutions proposed in this paper are applicable in the design of offshore/onshore steel pipes,supports of offshore platforms and other tubular structural steel members. 展开更多
关键词 steel pipes ultimate bending capacity strain hardening Hencky's total strain
下载PDF
Capacity Optimization Configuration of Hydrogen Production System for Offshore Surplus Wind Power
15
作者 Yanshan Lu Binbin He +6 位作者 Jun Jiang Ruixiao Lin Xinzhen Zhang Zaimin Yang Zhi Rao Wenchuan Meng Siyang Sun 《Energy Engineering》 EI 2023年第12期2803-2818,共16页
To solve the problem of residual wind power in offshore wind farms,a hydrogen production system with a reasonable capacity was configured to enhance the local load of wind farms and promote the local consumption of re... To solve the problem of residual wind power in offshore wind farms,a hydrogen production system with a reasonable capacity was configured to enhance the local load of wind farms and promote the local consumption of residual wind power.By studying the mathematical model of wind power output and calculating surplus wind power,as well as considering the hydrogen production/storage characteristics of the electrolyzer and hydrogen storage tank,an innovative capacity optimization allocation model was established.The objective of the model was to achieve the lowest total net present value over the entire life cycle.The model took into account the cost-benefit breakdown of equipment end-of-life cost,replacement cost,residual value gain,wind abandonment penalty,hydrogen transportation,and environmental value.The MATLAB-based platform invoked the CPLEX commercial solver to solve the model.Combined with the analysis of the annual average wind speed data from an offshore wind farm in Guangdong Province,the optimal capacity configuration results and the actual operation of the hydrogen production system were obtained.Under the calculation scenario,this hydrogen production system could consume 3,800 MWh of residual electricity from offshore wind power each year.It could achieve complete consumption of residual electricity from wind power without incurring the penalty cost of wind power.Additionally,it could produce 66,500 kg of green hydrogen from wind power,resulting in hydrogen sales revenue of 3.63 million RMB.It would also reduce pollutant emissions from coal-based hydrogen production by 1.5 tons and realize an environmental value of 4.83 million RMB.The annual net operating income exceeded 6 million RMB and the whole life cycle NPV income exceeded 50 million RMB.These results verified the feasibility and rationality of the established capacity optimization allocation model.The model could help advance power system planning and operation research and assist offshore wind farm operators in improving economic and environmental benefits. 展开更多
关键词 Surplus wind power offshore wind power hydrogen generation capacity optimization configuration total net present cost
下载PDF
Determination of Total Flavonoids and Its Antioxidant Ability in Houttuynia cordata 被引量:4
16
作者 Anyin Chen Wenjun Xiang +2 位作者 Dan Liu Changlu Liu Li Yang 《Journal of Materials Science and Chemical Engineering》 2016年第2期131-136,共6页
The total flavonoids of Houttuynia cordata are determined by UV-Vis spectrophotometry. The ex-traction condition of flavonoids from Houttuynia cordata includes: the extraction temperature is 70℃, solid-liquid ratio i... The total flavonoids of Houttuynia cordata are determined by UV-Vis spectrophotometry. The ex-traction condition of flavonoids from Houttuynia cordata includes: the extraction temperature is 70℃, solid-liquid ratio is 1:20, solvent is 80% ethanol, extraction time is 65 min. We studied the antioxidation of flavonoids in Houttuynia cordata, and results showed that flavonoids had strong reducing capacity, hydroxyl free radical scavenging activity and the superoxide anion radical scavenging ability, thus can provide a basis for the development of natural antioxidants. 展开更多
关键词 Houttuynia cordata total Flavonoids Antioxidant capacity
下载PDF
Total Antioxidant Status and Other Markers to Distinguish Severely Obese Volunteers with and without Metabolic Syndrome 被引量:1
17
作者 Sharmistha Singh Astha Dwivedi +1 位作者 Sandeep Kumar Poonam Chandra Mittal 《Food and Nutrition Sciences》 2019年第6期648-663,共16页
Obesity (Ob) is an accepted major risk factor for the metabolic syndrome (MetS), a combination of at least three of five risk factors, which predispose to high oxidative stress (OS), but all obese do not show symptoms... Obesity (Ob) is an accepted major risk factor for the metabolic syndrome (MetS), a combination of at least three of five risk factors, which predispose to high oxidative stress (OS), but all obese do not show symptoms of MetS. There is dearth of data comparing OS homeostasis of severely obese adults with and without MetS, and need for biomarkers to help in differential diagnosis. Erythrocytic lipid and protein damage markers, malondialdehyde (MDA) and protein carbonyl (PCO), antioxidant enzymes erythrocytic superoxide dismutase(SOD), catalase (CAT), plasma glutathione peroxidase (GPX), and total antioxidant capacity (TAC) as ferric-reducing-ability-of-plasma (FRAP) were compared to understand OS homeostasis among 102 severely Ob (body mass index > 30), 102 Ob with severe (z-score > 2) MetS as per National Cholesterol Education Program-Adult Treatment Panel III guidelines and 100 healthy non-obese Controls. MDA/PCO and all antioxidant enzymes were lowest for ObMetS, followed by Ob, indicating greater damage to protein moieties of the erythrocytic membrane. Multiple regression analysis confirmed z-scores > 2 as significant predictor of lowered enzymes and TAC. Receiver Operator Curve analysis predicted that TAC was the most potential biomarker for the diagnosis and prognosis of MetS with an Odds Ratio of 88.5 indicating the high probability that FRAP would be low for ObMetS (z-score > 2) than for Ob with BMI > 30, but z-scores < 1. TAC is qualified as the most effective biomarker to distinguish between severely obese respondents with and without metabolic syndrome, and as a useful candidate for study of homeostatic breakdown in metabolic syndrome and the importance of z-score in assessment of MetS in obese respondents. 展开更多
关键词 Obesity Body Mass Index Metabolic Syndrome Z-SCORE total Antioxidant capacity Biomarker
下载PDF
Evaluation of the Chemical Profiling,Total Phenolic Composition,the Antioxidant and Antimicrobial Properties of the Essential Oils of Mentha piperita L.,Salvia officinalis L.,and Thymus vulgaris L.
18
作者 Hulya Demir 《Journal of Food Science and Engineering》 2018年第6期263-270,共8页
The purpose of this study was to determine the chemical composition,total phenolic composition,the antioxidant and antimicrobial properties of the essential oils(EOs)of Mentha piperita L.,Salvia officinalis L.,and Thy... The purpose of this study was to determine the chemical composition,total phenolic composition,the antioxidant and antimicrobial properties of the essential oils(EOs)of Mentha piperita L.,Salvia officinalis L.,and Thymus vulgaris L.The essential oils of M.piperita L.,S.officinalis L.,and T.vulgaris L.were analyzed by means of gas chromatography-mass spectrometry(GC-MS)to demonstrate their chemical composition.The antioxidant properties of the EOs were evaluated with the 2,2-diphenyl-picrylhydrazyl(DDPH)free radical scavenging assay,their total phenolic compound contents were determined by the Folin Ciocalteau method,and their antimicrobial activities were evaluated by the disc diffusion assay.The major compounds in the contents of the essential oils of M.piperita L.,S.officinalis L.,and T.vulgaris L.were found to be eucalyptol,1R-α-pinene,and o-cymene,respectively.In the 2,2-diphenyl-picrylhydrazyl(DDPH)assay,the EO of M.piperita L.(8,930.01μMTE/g)demonstrated the highest antioxidant activity,followed by the activities of the EOs of T.vulgaris L.(157.76μMTE/g)and S.officinalis L.(115.54μMTE/g).The total phenolic compound contents of M.piperita L.,T.vulgaris L.,and S.officinalis L.were measured as 135.074,0.242,and 0.221 mMGAE/g.All essential oils showed antioxidant activities and antimicrobial activities.The highest antimicrobial activity against S.aureus,A.nigeris,and C.albicans was determined in the EO of M.piperita L.within diameters of 42,32,and 28 mm,respectively.These properties of essential oils are used in the pharmaceutical and food industries.The essential oils are approved as official medications in many countries and take place in their pharmacopoeias。 展开更多
关键词 Essential oils CHEMICAL COMPOSITION total PHENOLIC COMPOSITION ANTIOXIDANT capacity ANTIMICROBIAL activity
下载PDF
血清小而密低密度脂蛋白胆固醇和总抗氧化能力水平与脑梗死患者认知功能障碍的相关性分析 被引量:2
19
作者 马娟 郝晨光 +1 位作者 何丹 马建华 《江苏大学学报(医学版)》 CAS 2024年第2期161-165,175,共6页
目的:探究脑梗死患者血清小而密低密度脂蛋白胆固醇(small dense low-density lipoprotein cholesterol, sdLDL-C)和总抗氧化能力(total antioxidant capacity, T-AOC)水平变化及其与认知功能障碍发生的关系。方法:选择148例脑梗死患者... 目的:探究脑梗死患者血清小而密低密度脂蛋白胆固醇(small dense low-density lipoprotein cholesterol, sdLDL-C)和总抗氧化能力(total antioxidant capacity, T-AOC)水平变化及其与认知功能障碍发生的关系。方法:选择148例脑梗死患者,依据发病后7 d是否出现认知功能障碍,分为非障碍组(n=77)和障碍组(n=71);分别采用过氧化氢酶法和比色法测定两组血清sdLDL-C和T-AOC水平,并进行比较;Pearson相关系数法分析脑梗死患者血清sdLDL-C、T-AOC水平与蒙特利尔认知评估(MoCA)评分相关性;二元Logistic回归分析影响脑梗死患者认知功能障碍发生的危险因素。结果:与非障碍组相比,障碍组血清sdLDL-C水平明显升高(P<0.05),T-AOC水平明显降低(P<0.05)。相关性分析显示,血清sdLDL-C水平与MoCA评分呈负相关(r=-0.516,P<0.05),T-AOC水平与MoCA评分呈正相关(r=0.446,P<0.05)。Logistic回归分析显示,高血压、糖尿病、病情严重程度、血清sdLDL-C和T-AOC是脑梗死患者认知功能障碍发生的独立影响因素(P<0.05)。结论:脑梗死患者血清sdLDL-C水平升高,T-AOC水平降低,二者是影响脑梗死患者并发认知功能障碍的独立影响因素。 展开更多
关键词 脑梗死 认知功能障碍 小而密低密度脂蛋白胆固醇 总抗氧化能力
下载PDF
基于全面质量管理理论的临床专科能力建设实践 被引量:1
20
作者 罗莉 许媛媛 +4 位作者 姜若 黄阿红 俞骏仁 胡九东 狄建忠 《中国卫生质量管理》 2024年第3期21-24,共4页
临床专科能力建设是优质医疗资源扩容的基础。以全面质量管理理论的六要素为框架,从人才队伍建设(人)、设备耗材管理(机和料)、制度流程管理(法)、医院文化建设(环)、质量控制和系统评价(测)等6个方面阐述了临床专科能力建设的主要做法... 临床专科能力建设是优质医疗资源扩容的基础。以全面质量管理理论的六要素为框架,从人才队伍建设(人)、设备耗材管理(机和料)、制度流程管理(法)、医院文化建设(环)、质量控制和系统评价(测)等6个方面阐述了临床专科能力建设的主要做法。实践后,临床专科能力持续提升,并提高了优质医疗服务可及性。还需进一步整合各类资源,注重分院区专科能力建设,促进专科同质化发展。 展开更多
关键词 专科能力 专科绩效评价 全面质量管理 优质医疗资源
下载PDF
上一页 1 2 58 下一页 到第
使用帮助 返回顶部