Decontamination of Cr(Ⅵ) from water using sewage sludge-derived biochar: Role of environmentally persistent free radicals

Biochar is a well-known material for pollutant removal owing to its low cost and rich surface functionality. A kind of highly active substance, called environmentally persistent free radicals(EPFRs), can be produced in the preparation process of biochar, playing an important role in the removal of pollutants.In this study, sludge-derived biochars(SBC_(120) and SBC_(270)) were prepared by the hydrothermal carbonization under two temperatures(120℃ and 270℃) to investigate their removal abilities of Cr(Ⅵ). The maximum removal amounts of Cr(Ⅵ) by SBC_(120) and SBC_(270) were 16.58 and 22.93 mg·g^(-1), respectively. It was further revealed that the appearance of Cr(Ⅲ), as a result of EPFRs on sludge-derived biochar(SBC) transferred electrons to Cr(Ⅵ) in neutral solutions. That is to say, oxygen-centered(O-centered) EPFRs on SBC_(120) and carbon-centered(C-centered) EPFRs on SBC_(270) all could be used as electron donors to Cr(Ⅵ) to make it become Cr(Ⅲ). This study not only provides a theoretical basis for the mechanism of pollutants removal by sludge-derived biochar but also offers a new perspective on the direct effect of EPFRs on pollutants.

含喹啉杂环席夫碱的合成及清除DPPH自由基活性研究

以水杨醛及衍生物(水杨醛、5-甲基水杨醛、5-甲氧基水杨醛)和2-肼基喹啉为原料,合成了3种含喹啉杂环的腙类希夫碱(L1=水杨醛缩-2-肼基喹啉、L2=5-甲基水杨醛-缩-2-肼基喹啉、L3=5-甲氧基水杨醛-缩-2-肼基喹啉),并用红外、紫外可见-吸收光谱、质谱和核磁共振谱等手段表征其结构,采用1,1-二苯基-2-三硝基苯肼(DPPH)自由基法测试了它们的抗氧化活性,并考察了溶剂、温度、光照对清除DPPH自由基活性的影响。结果表明:以乙醇为溶剂,3种含喹啉杂环的希夫碱对DPPH自由基均具有较好的清除能力,温度、光照对其清除效果影响都较小。

毛蜂窝菌菌油化学成分分析与DPPH自由基清除活性

目的分析毛蜂窝菌菌油的化学成分并评价其1,1-二苯基-2-苦肼基(DPPH)自由基清除活性。方法以乙醚为提取剂,采用连续回流渗漉法提取毛蜂窝菌菌油,通过硅胶柱层析对菌油进行精制。毛蜂窝菌菌油化学成分经过气相色谱-质谱联用(GC-MS)技术分析,采用面积归一法测定菌油中各组分的相对含量,再用分光光度法评价其DPPH自由基清除活性。结果经GC-MS分析,毛蜂窝菌菌油中一共分离出了223个峰,鉴定出了44种化合物,占菌油的45.067%。相对含量最高的为(E,E)-亚油酸甲酯(5.362%),其次是甘油三亚油酸酯(4.147%),亚油酸甲酯(4.098%),相对含量均超过了4%。菌油DPPH自由基消除活性实验结果显示,一半DPPH自由基被清除时,菌油样品浓度为4.3540 mg/mL。结论毛蜂窝菌菌油的化学成分丰富多样,含有烷烃类化合物12种,脂类化合物12种,烯烃类化合物4种,酸类化合物5种,醇类化合物2种,醚类化合物3种,以及醛、胺等化合物。且该菌油具有有效的DPPH自由基清除活性。

两种体外评价抗氧化活性方法影响因素分析:DPPH和ABTS

目前体外评价抗氧化活性方法在食品、医药和化妆品等领域广泛应用,但没有一种方法可真实准确反映抗氧化剂的“总抗氧化能力”,每种检测方法都存在一定缺点和局限性。DPPH法和ABTS法因快速、简单、成本低、可检测大量样本等优点,被广泛接受并使用,但不同抗氧化剂溶剂、结构、浓度和空间可及性、吸收信号、反应时间等因素对测定结果准确性存在影响。本研究依据影响DPPH法和ABTS法检测准确性的不同因素分析发现,DPPH法更适合评价以有机溶剂为反应溶剂、非极性/极性较小、反应较慢的抗氧化剂,且容易受到抗氧化剂颜色的影响,如色素;光照、金属离子、pH值波动也会影响DPPH法的稳定性。ABTS法更适合评价以水为反应溶剂、极性较大、反应迅速的抗氧化剂。因此,为准确测定抗氧化剂活性,应依据样品特征选择适合方法,同时建议使用至少两种或以上方法,以全面反映抗氧化剂活性。

STUDIES ON FREE RADICAL SCAVENGING ACTIVITY IN CHINESE SEAWEEDS PART I. SCREENING RESULTS

Antioxidants have attracted the attention of researchers due to their beneficial effects as free radical scavengers. Application of a stable free radical named 1,1 diphenyl 2 picrylhydrazyl(DPPH) to screen the free radical scavenging activity in 27 species of Chinese seaweed showed that 15 of them had significant activity in at least one of the organic solvent extracts. The most interesting seaweed species were Gelidium amansii, Gloiosiphonia capillaris, Polysiphonia urceolata, Sargassum kjellmanianum, Desmarestia viridis, and Rhodomela teres.

Antioxidant activity and free radical scavenging activities of Streptomyces sp.strain MJM 10778

Objective:To investigate the antioxidant activity of soil-borne aetinobacteria.Methods:The total phenolic contents,the level of antioxidant potential by DPPH radical scavenging activity,MO scavenging activity,and ABTS radical scavenging activity in ethyl acelale extract were determined.Results:The 16 S rDNA sequencing analysis revealed that Streptomyces sp.strain MJM 10778.which was isolated from Hambak Mountain.Korea,has 99.9% similarity to Streptomyces misionensis(S.misionenis) NBRC 13063.The physiological and the morphological test revealed that the strain MJM 10778 has different characteristics from the strain NBRC.13063.The entire antioxidant assay with the ethyl acelale extract displayed good radical scavenging activity.The IC_(50) values of the strain MJM 10778 extract on DPPH,.NO.and ABTS radicals were identified to he 92.8 μg/mL,0.02 μg/ml,and 134.9 μg/mL,respectively.The ethyl acetate extract of the strain MJM 10778 showed an 81.500% of cell viability at 100 μg/mL in Raw264.7cell viability assay.Conclusions:The results obtained suggesl that the ethyl acetate extract of Streptomyces sp.strain MJM 10778 could be considered as a potential source of drug for the diseases that is caused by free radicals with its anti-oxidant activities and low cytotoxicity.

Constituents from Aerial Parts of Bidens ceruna L. and Their DPPH Radical Scavenging Activity

A new chalcone glycoside, butein-4-methoxyl-4′-O-（6＂-O-acetyl）-β-D-glucopyranoside（2）, along with seven known compounds, namely, quercitrin（1）, luteolin-7-O-β-D-glucopyranoside（3）, butein-4＇-O-β-D-glucopyranoside（4）, butein-4-methoxyl-4＇-O-β-D-glucopyranoside（5）, butin-7-O-β-D-glucopyranoside（6）, isoquercitrin（7）, and sulfurein（8） was isolated from aerial parts of Bidens ceruna L. Their structures were elucidated on the basis of spectroscopic studies. Compounds 1-8 were tested for their DPPH radical scavenging activity and, except compounds 2 and 5, other compounds showed scavenging activitv.

红外与微波预处理油茶籽对其原油DPPH自由基清除能力的影响

为了研究油茶籽油氧化稳定性机制,了解不同预处理方式对油茶籽油抗氧化能力的影响,以DPPH自由基清除能力为指标,对油茶籽分别经红外与微波预处理后得到的油茶籽原油及其极性组分和非极性组分抗氧化能力进行分析。结果表明:油茶籽分别经红外和微波预处理后,得到的油茶籽原油及其极性、非极性组分DPPH自由基清除能力变化显著;红外预处理的油茶籽所制油茶籽原油及其非极性组分的DPPH自由基清除能力高于相应微波预处理,其最大值分别高3.53μg/g和6.47μg/g;微波预处理的油茶籽所制油茶籽原油中极性组分的DPPH自由基清除能力最大值比相应红外预处理的高38.77μg/g。油茶籽原油对DPPH自由基的清除能力主要来自其极性组分,非极性组分的DPPH自由基清除能力弱于极性组分。

In vitro evaluation of anti-acetylcholinesterase and free radical scavenging potential of leaf extracts of some selected medicinal plants

Objective: To evaluate the phytochemical present in various solvent extracts from leaves of Ocimum sanctum(L.), Swertia chirayita(L.), Butea monosperma(Lam.) and Stevia rebaudiana(Bert.) as well as antioxidant and anticholinergic activities employing different in vitro models. Methods: Total phenol content of diethyl ether, chloroform and methanolic extracts obtained from leaves of different medicinal plants was determined by Folin-Ciocalteau's spectrophotometric method. Moreover, antioxidant and anticholinergic studies were conducted by four different in vitro methods which included diphenyl picrylhydrazyl radical scavenging, 2,2-azinobis(3-ethylbezoline-6-sulphonic acid), reducing activity by ferrous reduced antioxidant power and anti-acetylcholinesterase assay, in order to ensure pharmacological potential of the plants. Results: The methanolic leaf extract of Ocimum sanctum showed the highest total phenol content which was(21.13±1.04) GAE/g DW and antioxidant activities compared to other plants with the IC50 value of 40.43 μg/mL in diphenyl picrylhydrazyl radical scavenging assay and 53.5 μg/mL in 2,2-azinobis(3-ethylbezoline-6-sulphonic acid) assay as well as metal ion reduced by(78.22±0.38) TE/g DW in ferrous reduced antioxidant power assay. The inhibition percentage of the anti-acetylcholinesterase assay was(94.22±0.26)%. Conclusions: The results of our current study show that Ocimum sanctum leaf is the most significant source of phytochemicals that possesses antioxidant and anticholinergic properties. However, further investigation on isolation and characterization of active compound which is responsible for the pharmacological potential is needed.

"LIVING" FREE RADICAL SYNTHESIS OF NOVEL RODCOIL DIBLOCK COPOLYMERS WITH POLYSTYRENE AND MESOGEN-JACKETED LIQUID CRYSTAL POLYMER SEGMENTS

The synthesis of rod-coil diblock copolymers was achieved for the first time by TEMPO-mediated 'living' free radical polymerization of styrene and 2,5-bis [(4-methoxyphenyl)oxycarbonyl] styrene(MPCS). The block architecture of the two diblock copolymers thus prepared, MPCS-b-St(5400/2400) and MPCS-b-St(10800/8700), was confirmed by GPC, DSC studies and the formation of multimolecular micelles. (Author abstract) 10 Refs.

SYNTHESIS OF HETEROARM STAR-SHAPED POLYMER BY THE USE OF POLYFUNCTIONAL CHAIN-TRANSFER AGENT via CONVENTIONAL FREE RADICAL POLYMERIZATION

Heteroarm star-shaped polymers were synthesized by conventional free radical polymerization in two steps by the use of polyfunctional chain transfer agent.In the first step,free radical polymerization of methyl methacrylate was carried out in the presence of a polyfunctional chain transfer agent,pentaerythritol tetrakis(3-mercaptopropinate).At appropriate monomer conversions,two-arm PMMA having two residual thiol groups at the chain center or three-arm PMMA having one residual thiol group at the core were o...

AQUEOUS STABLE FREE RADICAL POLYMERIZATION PROCESSES

An overview of aqueous polymerizations, which include emulsion, miniemulsion and suspension polymerizations, under stable free radical polymerization (SFRP) conditions is presented. The success of miniemulsion and suspension SFRP polymerizations is contrasted with the difficulties associated with obtaining a stable emulsion polymerization. A recently developed unique microprecipitation technique is referenced as a means of making submicron sized particles that can be used to achieve a stable emulsion SFRP process.

Granulocyte colony-stimulating factor increases extracellular glutamic acid uptake and suppresses free radicals in an experimental model of amyotrophic lateral sclerosis

Excitatory amino acid toxicity and free radical damage play important roles in amyotrophic lateral sclerosis. Granulocyte colony-stimulating factor （G-CSF） protects nerve cells exposed to high-concentrations of glutamic acid, suggesting positive effects in the treatment of amyotrophic lateral sclerosis. The present study induced in vitro motor neuron injury using glutamic acid excitotoxicity, and the biochemical effects of G-CSF on glutamic acid concentration were determined. In addition, the effects of G-CSF on superoxide dismutase, glutathione peroxidase activity in motor neurons, and malondialdehyde and nitric oxide contents were analyzed. Immunohistochemistry was performed to measure neuronal survival. Results revealed that G-CSF significantly suppressed free radical activity, inhibited excitotoxicity, and reduced apoptosis and loss of motor neurons in the anterior horn of the spinal cord.

Liver Nuclear Activation of Carbon Tetrachloride or Bromotrichloromethane to Trichloromethyl and Trichloromethylperoxyl Free Radicals.Their Reactions With Lipids and Proteins

The formation of·CCl3 radicals in liver nuclei was suggested by spin trapping of them with N-t-butyl-α-phenylnitrone followed by GC/MS detection of the resulting adduct. Comparison of its formation in microsomal biotransformation of CCl4 was made. In aerobic nuclear activation mixtures containing NADPH and CCl4, significant decrease in the arachidonic acid content of nuclear lipids was observed (27. 8%, compared to control), the intensity of this decrease was lower than that occurring in the corresponding microsomal incubation mixtures (29.1%). Significant decreases in arachidonic acid content of nuclear and endoplasmic reticulum lipids were also observed in animals at 6 hours of poisoning with the haloalkane. During aerobic nuclear metabolism of CCl4 or CBrCl3, cholesterol oxidation products were detected: a ketocholesterol, an epoxide like structure and 7-ketocholesterol. Nuclear protein carbonyl formation was not promoted during nuclear CCl4 biotransformation. NADPH by itself may lead to protein carbonyl formation during prolonged periods of incubation. CBrCl3 in contrast, led to decreased protein carbonyl formation. No increase in nuclear protein carbonyl formation was observed in CCl4 intoxicated animals during periods of time between 1 to 6 hours after treatment. The results indicate that during nuclear biotransformation of CCl4 or CBrCl3 reactive free radicals, PUFA degradation, reactive aldehydes and cholesterol oxidation products are formed, nearby DNA and regulatory proteins.

Effects of Chuanxiongqin hydrochloride on increasing the fluidity of brain cell membrane and scavenging free radicals in model rats with ischemia/reperfusion injury

BACKGROUND: The fluidity of cell membrane can be affected by various factors. Many experiments have confirmed that the ischemia/reperfusion of organic tissue can increase the contents of free radicals, which lead to high rigidity and low fluidity of cell membrane, and the conditions can be changed by Chuanxiongqin. OBJECTIVE: To observe the effect and mechanism of Chuanxiongqin hydrochloride on the fluidity of brain cell membrane in rat models of ischemia/reperfusion. DESIGN: A completely randomized controlled animal trial. SETTINGS: Institute of Brain Sciences; Department of Physiology, Medical College, Datong University. MATERIALS: Twenty male grade Ⅰ Wistar rats of 170-220 g were randomly divided into model group (n =10) and control group (n =10). Chuanxiongqin hydrochloride (molecular mass was 172.2) was purchased from the National Institute for the Control of Pharmaceutical and Biological Products (batch number: 0817-9803); Spin labelers: 5-doxyl-stearlic acid methylester (5DS), 16-doxyl-stearlic acid methylester (16DS), xanthine, xanthine oxidase (XOD) and 5,5-dimeth-1-pyrroline- N-oxide (DMPO) from Sigma Company; Bruker ESP 300 electron paramagnetic resonance (EPR) spectrometer by Bruker Company (Germany). METHODS: The experiments were carried out in the State Key Laboratory of Natural and Biomimetic Drugs, Peking University from June 2001 to July 2002. In the model group, rats were made into models of cerebral ischemia by 30-minute ligation and 2-hour reperfusion of common carotid arteries; The rats in the control group were not made into models. The order parameter (S) and rotational correlation time (τc) were detected with the ESR spectrometer by means of spin labeling. The greater the S and τc, the smaller the fluidity. Meanwhile, the clearance rate of free radicals was detected with ESR spin trapping. The measurement data were compared using the t test. MAIN OUTCOME MEASURES: The S, τc and clearance rates of O2 · and OH· free radicals were compared between the model group and control group. RESULTS: The S and τc in the model group [0.738 4±0.003 5; (8.472±0.027)×10-10 s/circle] were obviously different from those in the control group [0.683 9±0.008 3; (7.945±0.082)×10-10 s/circle, t =5.731, 5.918, P < 0.05], which suggested that ischemia/reperfusion injury decreased the fluidity of brain cell membrane. After adding Chuanxiongqin hydrochloride, there were no obvious differences between the model group [0.688 5±0.030 5; (7.886±0.341)×10-10 s/circle] and control group (P > 0.05), indicating that Chuanxiongqin hydrochloride could recover the fluidity of brain cell membrane after ischemia/reperfusion injury close to the level in the normal control group. Chuanxiongqin hydrochloride could directly scavenge the O2 · and OH· free radicals, and the maximal clearance rates were 83.92% and 44.99% respectively. CONCLUSION: Chuanxiongqin hydrochloride increases the fluidity of membrane of ischemia-injured brain cell by scavenging both O2 ·and OH· free radicals.

The Scavenging of Free Radical and Oxygen Species Activities and Hydration Capacity of Collagen Hydrolysates from Walleye Pollock(Theragra chalcogramma) Skin

Fish skin collagen hydrolysates(FSCH) were prepared from walleye pollock(Theragra chalcogramma) using a mixture of enzymes,namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of <1 000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems,including diphenylpicrylhy-drazyl radical(DPPH),superoxide anion radical,hydroxyl radical and hydrogen peroxide model,and compared with that of a native antioxidant,reduced glutathione(GSH). FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore,FSCH may have potential applications in the medicine and food industries.

NITROXIDE-MEDIATED FREE RADICAL SYNTHESIS OF MESOGEN-JACKETED LIQUID CRYSTAL POLYMERS

The first TEMPO-mediated 'living' free radical polymerization of liquid crystalline monomer, 2, 5-bis[(4-methoxyphenyl)oxycarbonyl]styrene (MPCS), was carried out at 130 degrees C with BPO as an initiator. The molecular weight of the polymer can be varied from rather low values to high values while maintaining narrow polydispersity. It was observed that the polymerization of MPCS proceeded much faster than that of styrene. A tentative explanation for this fast polymerization was suggested.

Effect of Selenium Poisoning on Immune Function and Oxygen Free Radicals in Erythrocyte of Pig

[ Objective] This study was to investigate the effect of selenium（Se） on immune function and oxygen free radicals in erythrocyte of pig. [ Method] Fifteen weanling Landrace piglets as experimental animals were divided into three groups, two testing groups and one control group. For each group, Se content in whole blood, immune function of erythrocytes, activity of whole blood glutathione peroxidase（GSH-Px）, activity of blood plasma superoxide dismutase（SOD）, and blood plasma malondialdehyde（MDA） content were determined. [ Result] Compared with the control group, Se content in whole blood and blood plasma MDA content increased remarkably, while whole blood GSH-Px activity and blood plasma SOD activity decreased; RBC-C1 RR assumed a rise-fall trend, and RBC-ICR showed no obvious change. [Condusion] Se poisoning can reduce the activity of antioxidant enzymes, disturb the balance of oxygen free radicals metabolism, thereby inducing erythrooyte immune function in piglets.

THE ACTION OF CAPTOPRIL ON SCAVENGING OXYGEN FREE RADICALS

The protective effect of captopril on ischemic myocardium was studied in 40 patients with congenital heart disease accompanied with pulmonary hypertention.Twenty of these patients received captopril 50 mg b.i.d.for three months preoperatively (Group A).The other 20 patients without pretreatment with captopril were used as controls (Group B).In Group A,the cardiac output increased and the pulmonary pressure decreased significantly in the first 24 hours postoperatively,indicating a high cardiac output with a low vascular resistance.The differences or CPK,CPKMB,LDH release between Group A and Group B were highly significant or siguificant from the end of operation to 24 hours postoperatively. Myocardial protection in the reduction of the release of CPK, CPK-MB, LDH might be attributed to action on scavenging oxygen free radicals.

Influence of rotating magnetic field on cerebral infarction volume, cerebral edema and free radicals metabolism after cerebral ischemia/reperfusion injury in rats

BACKGROUND: It has shown that magnetic field can improve blood circulation, decrease blood viscosity, inhibit free radicals, affect Ca2+ flow in nerve cells, control inflammatory and immunological reaction, and accelerate nerve cell regeneration. In addition, protective effect of magnetic field, which acts as an iatrophysics, on ischemic brain tissues has been understood gradually. OBJECTIVE: To investigate the effects of rotating magnetic field (RMF) on volume of cerebral infarction, cerebral edema and metabolism of free radicals in rats after cerebral ischemia/reperfusion injury. DESIGN: Randomized controlled animal study. SETTING: Rehabilitation Center of disabled children, Liaoniang; Department of Rehabilitation, the Second Affiliated Hospital, China Medical University; Department of Rehabilitation Physiotherapy, the First Affiliated Hospital, China Medical University. MATERIALS: A total of 70 healthy Wistar rats aged 18-20 weeks of both genders were selected and randomly divided into 3 groups: sham operation group with 12 rats, control group with 20 rats and treatment group with 38 rats. The treatment group included 4 time points: immediate reperfusion with 6 ones, 6-hour reperfusion with 20 ones, 12-hour reperfusion with 6 ones and 18-hour reperfusion with 6 rats. Main instruments were detailed as follows: magnetic head of rotating magnetic device was 6 cm in diameter; magnetic induction intensity at the surface of magnetic head was 0.25 T in silence; the maximal magnetic induction intensity was 0.09 T at the phase of rotation; the average rotating speed was 2500 r per minute. METHODS: The experiment was carried out in the China Medical University in March 2003. Focal cerebral ischemic animal models were established with modified Longa’s method. Operation was the same in the sham operation, but the thread was inserted as 10 mm. Neurologic impairment was assessed with 5-rating method to screen out cases. Those survivals with grade 1 and grade 2 after ischemia for 2 hours and reperfusion for 24 hours were included in the control group and treatment group. Those in the sham operation group and control group were not treated with RMF. Magnetic head was directed towards the head of rats of the treatment group, and the magnetic head was about 7 mm from skin, treated for 15 minutes. The rats were decapitated to take out brains at 24 hours after reperfusion in each group. Water content of brain and volume of cerebral infarction were assessed with wet-dry weight method and TTC staining, respectively. Activity of superoxide dismutase (SOD), content of malondialdehyde (MDA) and change of brain histomorphology in brain tissue of ischemic side were analyzed. MAIN OUTCOME MEASURES: ① Volume of cerebral infarction and changes of water content in brain; ② measurements of SOD and MDA contents in brain tissue of rats in all groups. RESULTS: A total of 70 qualified animals were involved in the final analysis after rejecting the death and unqualified animal models. ① Water content of brain: Water content of brain in the treatment was less than that in the control group at any time point except the immediate time point, and cerebral edema was relieved [(2.48±0.22)%, (2.32±0.19)%, (2.23±0.36)%, (2.91±0.44)%, P < 0.05]. In addition, there were no significant differences among 6-hour, 12-hour and 18-hour reperfusion groups (P > 0.05). ② Volume of cerebral infarction: The absolute volume of cerebral infarction in the treatment group was smaller than that in the control group [(128.21±15.05), (171.22±40.50) mm3, t =2.438, P < 0.05], and the relative volume of cerebral infarction was smaller than that in the control group [(20.22±1.44)%, (25.17±3.85)%, t =2.95, P < 0.05]. ③ Contents of SOD and MDA in brain tissues: Compared with the control group, the SOD content in the brain tissue in the treatment group increased [(54.54±3.85), (69.52±5.88) kNU/g, t =5.568, P < 0.05], while the MDA content decreased [(0.85±0.06), (1.03±0.09) μmol/g, t =4.076, P < 0.05]. ④ General morphological observation: General morphology manifested that the edema was distinct in the right cerebral hemisphere in the control group, showing fat-like white, shallow anfractuosity, flat gyria, brittle tissue and easy to break up. The edema of right cerebral hemisphere was light and surface was hyperaemia in the treatment group. CONCLUSION: RMF may improve anti-oxidative ability of brain tissue of rats with acute focal cerebral ischemia/reperfusion injury and reduce volume of cerebral infarction and degrees of cerebral edema.