جستجوی مقالات مرتبط با کلیدواژه « پراکسید هیدروژن » در نشریات گروه « پزشکی »

Oxidative stress and apoptosis due to hydrogen peroxide poisoning have a major effect on the physiological and pathophysiological mechanisms of the lung. This study aims to evaluate the effect of aerobic exercise and Tribulus terrestris extract on some indicators of oxidative stress and lung tissue apoptosis in poisoned male Wistar rats. 

In this experimental study, 49 male rats aged 10-12 weeks were randomly divided into seven groups: Control, Poisoned, Poisoning+ Exercise, Poisoning+ Supplementation 1 (Tribulus terrestris 5 mg/kg), Poisoning+ Supplementation 2 (Tribulus terrestris 10 mg/kg), Poisoning+ Exercise + Supplementation 1, Poisoning+ Exercise+ Supplementation 2. The aerobic exercise program consisted of eight weeks (5 days a week) of running on a treadmill at a speed of 20 meters per minute for 60 minutes per session. Alcoholic extract of Tribulus terrestris at two doses of 5 and 10 mg/kg was administered to the target animals by gavage for eight weeks. Serum levels of oxidative stress markers were measured with special kits, and the expression of apoptotic markers of lung tissue was measured by immunohistochemistry. The study hypotheses were analyzed using two-way analysis of variance and Least Significant Difference post hoc test, considering a significance level of P<0.05.

Eight weeks of aerobic exercise significantly increased Adenosine Triphosphate (ATP) (F=19.238, P=0.002, ƞ2=0.468) and significantly reduced Cytochrome C concentration (F=68.970, P=0.001, ƞ2=0.697) and Prooxidants-Antioxidant balance (PAB) (F=12.025, P=0.001, ƞ2=0.464), while had no significant effect on malondialdehyde (MDA) (F=1.067, P=0.169, ƞ2=0.044). Both doses of Tribulus terrestris extract significantly reduced PAB (F=10.118, P=0.001, ƞ2=0.403) while its 10 mg/kg dose increased ATP (F=35.040, P=0.001, ƞ2=0.701) and reduced cytochrome C (F=13.730, P=0.004, ƞ2=0.417) and MDA (F=5.824, P=0.002, ƞ2=0.372) concentrations. After receiving 5 and 10 mg/kg doses of Tribulus terrestris extract and eight weeks of aerobic exercise, The expression of Bax protein (F=54.247, P=0.001, ƞ2=0.804; F=51.201, P=0.002, ƞ2=0.754) and Caspase 3 (F= 49.118, P=0.003, ƞ2=0.504; F=49.001, P=0.004, ƞ2=0.498) were significantly reduced while the BCl-2 expression (F=63.014, P=0.001, ƞ2=0.815; F=50.112, P=0.003, ƞ2=0.706) significantly increased. The most changes in the study markers were observed when aerobic exercise was combined with 10 mg/kg of Tribulus terrestris extract supplementation. 

It seems that 8 weeks of aerobic exercise can reduce the effects of oxidative stress and apoptosis caused by hydrogen peroxide poisoning. However, the effects of Tribulus terrestris extract may be dose-dependent in some cases. Although the combination of aerobic exercise with Tribulus terrestris extract supplementation has better results in controlling oxidative stress enzymes and apoptotic factors, for better results, longer training duration and higher doses of extract are recommended.

The most used dyes in textile industries are Azo Group dyes. Azo dyes have complex aromatic compounds, low chemical and biodegradable stability. Due to these properties, treatment of this type of wastewater by conventional methods will not meet environmental standards. The advanced oxidation process has been widely used to treat organic matter from wastewater. In this study, dye purification of azo dye Reactive Red 195 by UV/H2O2 process was investigated. Moreover, the parameters affecting this process have also been determined.

In this study, dye treatment was conducted in the presence of different concentrations of hydrogen peroxide, and at different retention time, temperature and pH values in a continuous photoreactor equipped with UV lamps. Using central composite design and response surface methodology (RSM), effects of various concentrations of hydrogen peroxide, retention time, temperature, and pH on the color and COD removal were studied in the range of 0–2%, 60-240 min, 25-80 oC, and 3-10, respectively.

The results showed that the concentration of hydrogen peroxide and retention time were the most influential parameters on color and COD removal. Color removal significantly enhanced by increasing retention time and H2O2 concentration to 200 min and 1.2%, respectively. pH increase had positive effect on color removal. There were increases in the rate of color and COD removal as the temperature went up to 50 oC. However, temperature of 80 oC negatively impacted AOP process. According to RSM, the optimum factor levels were achieved at 1.28%, 240 min, 49 oC and 10 for concentrations of hydrogen peroxide, reaction time, temperature, and pH, respectively.

According to the result, UV/H2O2 proved to be capable of degrading Reactive Red 195. Almost all the azo dye color destroyed after 209 min while 87.52 % of the COD was removed after 240 min of irradiation.

The presence of drugs in water and wastewater sources poses risks to humans and the environment. These materials are not completely eliminated by conventional water and wastewater treatment methods. This study aimed to investigate the photocatalytic removal of acetaminophen from aqueous solutions by the advanced UV/H2O2/ZnO oxidation method.

In this experimental analytical study, zinc oxide and hydrogen peroxide were used in a 500 ml reactor under UV-C irradiation to remove acetaminophen. The effects of initial parameters of acetaminophen, solution pH, contact time, hydrogen peroxide concentration, and zinc oxide nanoparticle concentration were investigated. Experiments were designed and analyzed using the CCD method by Design Expert 10 software.

Themaximum removal efficiency of acetaminophen was obtained as 94% at pH 7, contact time 8 min, the initial contaminant concentration 62.5 mg/l, catalyst dose 0.0275 g, and H2O2 concentration 2 ml. By changing the time to 1 and 15 minutes, the removal rate decreased by 26 and 76%, respectively, and by increasing the catalyst dose from 0.0275 g to 0.05 g, the removal rate increased by 99%.

In this study, the efficiency decreased with increasing contaminant concentration. The removal efficiency was higher in neutral conditions than in acidic and alkaline conditions. The photocatalytic process (UV/H2O2/ZnO) is highly potent for removing acetaminophen from aqueous solutions.

One of the most important factors in the contamination of aquatic ecosystems is agricultural pesticides. Paraquat is a water-soluble and non-selective herbicide, which has adverse health effects, such as respiratory distress and even death. This study aimed to evaluate the degradability of paraquat toxins using photochemical oxidation processes based on hydrogen peroxide (UV/HP) and persulfate (UV/NaPS/Fe2 +).

This experimental study investigated the effects of pH variables, concentrations of UV/HP and UV/NaPS/Fe2+, as well as the initial concentration of the pollutant on paraquat toxicity removal in a laboratory scale using a batch reactor of one liter. Moreover, the concentration of the residual paraquat and the amount of organic carbon removal were measured using High Performance Liquid Chromatography equipped with a visible Ultraviolet (UV) detector at 259 nm and a Total Organic Carbon (TOC) meter.   

The UV/HP and UV/NaPS/Fe2 + processes were able to remove 87.75% and 92.31% paraquat, respectively, at 120 min under optimum conditions. In addition, the amount of TOC removal in the UV/HP and UV/NaPS/Fe2 + processes  were 77.29% and 82.16%, respectively. The results showed that the kinetics of the UV/HP and UV/NaPS/Fe2 + processes  followed the first-order reaction.

The UV/NaPS/Fe2 + process was more effective than that of UV/HP regarding paraquat removal. As a result, the studied processes are proposed as effective, fast, and efficient methods to remove paraquat from aqueous solutions, which is economically feasible due to the low reaction time. The use of this process is also recommended as a complete refinement or pre-treatment process.

One of the complications of diabetes is the occurrence of apoptosis in the brain that can lead to cognitive impairment. The aim of this study was to investigate the effect of 4 weeks of voluntary wheel running on hippocampus semaphorin 3B, hydrogen peroxide, and apoptosis in streptozotocin-diabetic rats.

In this experimental study, 32 male Wistar rats weight 235±10gr were assigned randomly to 4 groups (n=8): healthy control (C), healthy exercise (E), control-diabetic (D) and diabetic-exercise (ED). Rats were diabetic by intra-peritoneal injection of STZ dissolved in citrate buffer. The experimental groups ran voluntarily in the wheel running for 4 weeks. The subjects were sacrificed 48 hours after the last training session, then hippocampus tissue was extracted from the brain, and ELISA measurements were performed after homogenization and centrifugation of the tissue. One-way ANOVA and independent t-test were used to evaluate the data.

The levels of semaphorin 3B, hydrogen peroxide and apoptosis in D group were significantly higher than C group (P≤0.05). In the ED group, semaphorin 3B, hydrogen peroxide and apoptosis levels were significantly lower than D group (P≤0.05). Semaphorin 3B and apoptosis levels in the E group were significantly lower than C and ED groups (P≤0.05).

The results showed that experimental diabetes induction increases semaphorin 3B, hydrogen peroxide and apoptosis rate in the brain hippocampus. Four weeks of voluntary running was associated with a decrease in the hippocampus levels of semaphorin 3B, hydrogen peroxide and apoptosis.

Due to the large volume of water consumed in textile industry and producing the colored wastewater containing non-biodegradable organic dyes, in the present study the interaction of hydrogen peroxide and nanophotocatalyst in the advanced oxidation process was investigated.

In this research, after synthesizing of nanophotocatalyst (ZnO:Ag:Nd) the effect of hydrogen peroxide on dye removal process, and its interaction with the catalyst was investigated. photocatalyst was characterize by  (FESEM) Field-emission Scanning Electron (EDS) Energy-dispersive X-ray spectroscopy (XRD) X-ray diffraction methods. Then, the effect of important operating parameters such as dye concentration (10-30 ppm), pH (3-9), The amount of photocatalyst (0.02-0.1g.L-1) temperature (30-50°C), hydrogen peroxide concentration (F=2-11) was evaluated in AOPs process. Process modeling was done by using the response surface methodology.

The results showed that by adding hydrogen peroxide to photocatalyst particles, the efficiency of decolorization was increased, but the addition of catalyst to the optimum amount of hydrogen peroxide reduced the efficiency of decolorization. Also, the optimum conditions for the removal of dye matter (pH=6.21) and the amount of photocatalyst 0.08g.L-1, F=9was achieved. The results of the thermodynamic studies showed the endothermic reaction of the process, and process modeling indicated that the theoretical result were in accord with the experimental results.

Based on the results, combination of using catalysts and hydrogen peroxide is an effective technique for dye removal of aqueous solution.

The aim of this study was to determine the interaction effect of forced swimming and crocin supplementation on the expression of BAX and BCL-2 cardiomyocyte genes in male rats poisoned by hydrogen peroxide (H2O2). 36 male Wistar rats were randomly divided into six groups of sham, H2O2, H2O2 and crocin, H2O2 and forced swimming, H2O2 and crocin and forced swimming, and control. The forced swimming protocol was 60 minutes, 5 days a week, for 6 weeks. H2O2 (1 mg/kg for 3 weeks) and crocin (12.5 Mm/kg daily with 5 cc of distilled water) were injected intraperitoneally. Real time polymerase chain reaction (PCR) device was used to assess gene expression, and apoptosis was assessed using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method. Statistical analysis was done using Kolmogorov-Smirnov, Levene, one-way ANOVA and, the Scheffe post hoc tests. H2O2 induction was associated with a significant increase in the apoptosis of BAX (P < 0.001). Six weeks of exercise in water tended to reduction in the BCL-2 expression (P = 0.023), and induction of crocin resulted in significant decrease in BAX expression. The interaction between swimming, crocin and H2O2 decreased BAX and increased BCL-2 expression, which indicated the protective effect of regular activity in reducing cardiomyocyte apoptosis. Forced swimming as well as the use of crocin separately led to a significant reduction in BAX gene expression and a significant increase in BCL-2 gene expression. On the other hand, the combination of exercise and crocin had synergistic and synergistic effects in inhibiting the apoptotic expression of BAX and also enhancing the expression of the anti-apoptotic gene of BCL-2 in rats poisoned by H2O2.

There is clear evidence to support the importance of regular physical activity and the use of antioxidants in the prevention or control of cardiovascular diseases, especially those that cause cardiac apoptosis. Our aim in this study was to determine the simultaneous effect of six weeks forced swimming and Crocin supplementation on the expression of 3 cardiomyocyte gene caspase in male rats infected with hydrogen peroxide. 36 male Wistar rats were randomly divided into six groups of sham injections (saline), hydrogen peroxide, hydrogen peroxide and Crocin, hydrogen peroxide and forced swimming, hydrogen peroxide and forced swimming and Crocin, control group. The forced swimming protocol was held in two stages in training and exercises. For induction, H2O2 was given as sub peritoneal injection for 3 weeks once every other day and 30 minutes before the exercise. Crocin was injected in the peritoneum. Real Time PCR was used to express the Caspase 3 gene. To confirm the incidence of apoptosis, tissue samples were assessed by Tannel method. Statistical analysis was performed using Kolmogorov-Smirnov test for natural distribution. Then, the variance (Levin test) and Perth data were analyzed. Finally, one-way ANOVA was used to test the statistical hypotheses and the Scheffe post hoc test was used. Hydrogen peroxide induction was associated with a significant increase in expression of Caspase 3 gene expression and six weeks of forced swimming resulted in a significant decrease in Caspase 3 gene expression in rats' myocardial tissue, as well as interaction of six weeks of forced swimming and induction of Crocin, Caspase 3, which is completely visible in the results of the Tannal. Regular forced swimming as well as Crocin consumption separately led to a significant reduction in gene expression. Caspase 3 was found in the rat's myocardium tissue. On the other hand, the combination of training and Crocin had a synergistic effect on inhibiting Caspase 3 gene expression in hydrogen peroxide poisoned rats.

among the different type of antibiotics, the tetracycline occupied the 2end level of the more prevalence types in produce and use aspect worldwide and their existence in domestic wastewater will pollute our water resources. The aim of this study was to determine the performance of US/UV/H2O2 processes when reduction of tetracycline antibiotic from an aqueous environment was objected.
Material and the current experimental study use the ultrasonic bath simultaneously with ultraviolet wave and hydrogen peroxide. To detect the effect of variables include contact time(5-60 min), the antibiotic concentration (5-25 mg/l), pH(3-10), hydrogen peroxide concentration (5-20 mg/l) and the input power (90- 300 W) of instrument in process, the reactor has been sampled in different intervals and the residue concentration to be used to detect with spectrophotometer instrument in 261 nm length wave.
the result have been showed that the separately use of UV and US will not take a high performance with the best removal percent of 16% and 32%. Simultaneously use of US/UV/H2O2 cached a more highly reduction in tetracycline concentration and the best reduction was 83 % removal that took place in pH= 4.5, antibiotic concentration of 10 mg/I, input power of 240 W, hydrogen peroxide concentration of 20 mg/l, time equal with 50 min.
the result have been showed that the US/UV/H2O2 process can be used as a performance process to remove the tetracycline antibiotic from an aqueous environment.

Hydrogen peroxide is one of the compounds that is primarily produced by the oxidation of oil and fat and causes various diseases, including atherosclerosis and coronary artery disease .The aim of this study was to survey the peroxide value of edible oils used in sandwich and falafel shops in Tehran in 2016.
In this study, sampling from a number of fast food centers was done randomly. After the transfer of samples to the chemistry laboratory of environmental health engineering department, the peroxide number was determined based on the national standard procedure 4179. The data was analyzed by SPSS software for descriptive statistical parameters and t-test.
According to the National Iranian Standards, from total of 50 samples of the sandwiches taken, 20 samples (40 %) were consumable and 30 samples (60 %) were inedible. Also, from 40 samples of falafel taken, 14 samples (35 %) were consumable and 26 samples (65 %) were inedible. The maximum peroxide values of sandwiches and falafel were 29.79 and 31.22 meq/kg, respectively.
The findings show that Peroxide value in the sandwich and falafel shops were higher than the standard, and thus it seems that having an educational plan for staff regarding the correct methods of frying food is necessary.

Metformin is an anti-diabetic drug, which may be a novel therapeutic option for treatment of atherosclerosis. The current study evaluates protective capacity of metformin in hydrogen peroxide (H2O2)-induced oxidative stress in human umbilical vein endothelial cells (HUVECs).

Endothelial cells were treated with metformin for 24 h. Then they were treated with 0.5 mM H2O2 for 2h. Cell viability was measured by 3‑(4,5-dimethylthiazol-2-yl)-2, 5‑diphenyltetrazolium bromide (MTT) assay. Reactive oxygen species (ROS) levels were measured using 2, 7 dichlorodihydrofluorescein diacetate (DCF-DA) assay. Lipid peroxidation (LPO), total thiol groups and total antioxidant power (TAP) were also evaluated.

Metformin at concentration of 20 μM increased survival of HUVECs exposed to H2O2. ROS and MDA levels increased in H2O2-treated endothelial cells. Metformin could significantly decrease H2O2-induced ROS and MDA elevation. It also increased total thiol groups and TAP.

Metformin protects HUVECs against the oxidative stress and apoptosis induced by H2O2.

Increasing consumption of fast foods such as sandwiches, burgers, etc. among adolescents and young people as well as the cooking method of fast foods which is mostly in the frying form, and the high frying oil endanger the consumer health due to the hydrolysis, oxidation, and polymerization of the edible oil. The aim of this study was to assess the amount of peroxide in delicatessen oils used in the fast food shops of Kermanshah City, Iran, in the year 2016.

In this cross-sectional study, according to the No. 493 standard of Iranian Institute of Standards and Industrial Research, 81 samples of edible oils were collected from the fast food shops of Kermanshah City. The samples were then transferred to the laboratory, and their peroxide value measured according to standard No. 4179; the obtained values were assessed.
Findings: From a total of 81 samples, 59% (48 samples) were usable at the standard level, and 41% (33 samples) useless and higher than the standard level. Moreover, the minimum and maximum oxidation numbers were 0 and 29, respectively.

Considering that the peroxide amount was exceed the recommended limit almost in half of the tested edible oils, consequently, additional monitoring, increasing the consumers’ awareness, and health training courses for workers in this sector seem to be necessary.

Due to their polycyclic and toxic structure, dyes have a high ability in causing adverse acute and chronic effects on human exposed to them. In present study, the decolorization of acid green3 from aqueous solution by UV/ H2O2 method was investigated
This is an applied-experimental study. Parameters of pH in the amount of 3,7 and 11, contact time in 5,15, 30, 45 and 60 min, dose of H2O2 in 10, 30 and 50 mg/l and initial concentration of acid green3 in 50, 100 and 150 mg/l were examined to reveal the optimum amounts of these parameters. In order to emit the UV radiation, photo reactor with a 2-lit volume was applied, also to measure remaining concentration of dye, spectrophotometer device, model DR 5000 was employed. Chemical oxygen demand (COD) test based on 5220C method (standard method book) was used for determining amount of oxidation.
Results showed that contact time = 60 min, pH=7, acid green concentration=50 mg/l and dose of H2O2 =30 mg/l are optimum condition at which the removal amounts of dye and COD were obtained about 97 and 85%, respectively.
In the study, it is observed that parameters of contact time, pH, initial concentration of dye, and dose of H2O2 have a significant influence on the removal of the dye by UV/H2O2 process. Due to acceptable results of UV/H2O2 in the oxidation of the dye and the reduction of COD, this method can be introduced as reliable process to remove of acid green 3 from industrial wastewaters.

Polyvinyl alcohol is a persistent and water-resistant compound found in effluent of many industries and can be harmful to human health. Its presence in water supplies may cause problems in the process of settlings and removing heavy metals. This study aimed to determine the efficiency of Mn3O4 / H2O2 process to remove PVA.
This laboratory-scale research done to study the effects variables influencing process of Mn3O4/H2O2 including pH, hydrogen peroxide concentration, concentration of Mn3O4 nanoparticle, reaction time and concentration of PVA. To determine structural characteristics of nanoparticles XRD, BET SEM, and FTIR analyzes were used. Maximum absorption of contaminant by spectrophotometer was determined at 690 nm and the concentrations of PVA were determined by calibration curve.
BET analysis showed size of 19 nm for nanoparticles. Laboratory results showed that removal efficiency for Mn3O4/H2O2 process is 67.98% at; pH=3, Mn3O4 concentration= 0.4 g/l, concentration of hydrogen peroxide=20 mmol/l, reaction time=120 minutes, initial concentration PVA=100 mg/l. Removal efficiency decreased by increasing initial concentration of PVA and maximum efficiency of 71% observed for Mn3O4/H2O2 processes at initial concentration of 25 mg/l. UV radiation increased the efficiency of the process to 100% after 40 minutes.
In accordance with the results hydrogen peroxide activated by Mn3O4 catalyst is a suitable option for pre-treatment of waste water containing polyvinyl alcohol.

Phosphate is known to be the main limiting elements in the reuse of wastewater effluents and then it is the key element to outbreak of eutrophication. Therefore the objective of this work was to investigate the adsorption of phosphorous by natural and surface modified pumice with H2O2.
The present work was a fundamental-practical study which done in batch system. In this work, natural and modified pumice were used for removal of phosphorous from aqueous solution. Several experimental parameters including pH (2-10), adsorbent mass (2-10 g/L), initial phosphorous concentration (5-20 mg/L), ionic strength and contact time were studied. All experiments were conducted in batch system with varying one experimental parameter, while others were constant.
The results show that modification of pumice with H2O2 will improve adsorbent sorption capacity without any structural distortion. In addition, higher removal efficiency was observed at 10 g/L of adsorbent dose, pH 6, 130 min contact time and 20 mg/L of phosphorus concentration. In the optimal conditions, 69% and 97% of phosphorus removal were achieved by natural and modified pumice adsorbents, respectively. In addition, removal efficiency decreased for increasing ionic strength. Pseudo second order kinetic model best describe adsorption of phosphorus onto used adsorbent.
The results of present work well demonstrate that pumice have substantial adsorption capacity for phosphorus and in the case of its modification, its adsorption capacity will be improved.

BPA is a non biodegradable antioxidant that has greatly hazardous for human and animals health. and Because of the eliminating alone fewness amount of the BPA during the wastewater treatment, wastewater that contains BPA can be source of pollution in aqueous solution. The objective of this study was Performance of ultrasonic and H2O2 technologies in removal of BPA from aqueous solution.
Experiments of sonochemical was carried out with use of unit ultrasonicator (Elma), which in the two power 300 and 500W, frequencies at 35 and 130KHz. Hydrogen Peroxide in concentrations at 5, 15 and 30mg/lit was applied. Initial concentration BPA at limits 2, 5, 20 and 50 mg/lit which For measuring concentration of BPA used from Spectrometer UV/VIS Lambada 25 Perkin Elmer, Shelton unit.
The results demonstrated that hybrid ultrasonic and peroxide Hydrogen processes with Efficiency 98.65%, has the highest efficiency in the removal of BPA. The most decomposition rate achieved at the frequency of 130 KHz and 500W assisted by 30mg/lit H2O2 at pH 11. Also the results demonstrated that with pH increase destruction rate BPA the increased by any three processes (ultrasonic, H2O2 and both hybrid).
The results demonstrated that hybrid ultrasonic and peroxide Hydrogen processes can be used as a clean method and friendly environment for waters treatment are contains desirable BPA.

Paraoxonase-1, Adiponectin and Hydrogen Peroxide are among indexes that are influenced by sedentary lifestyle; and it is possible that they’ll be effective on blood pressure. However, it is not clear the relationship between their changes with blood pressure as a result of participation in regular physical activity. So, the aim of this research was to investigate the effect of 12 weeks moderate aerobic exercise on relationship between Paraoxonase-1, Hydrogen Peroxide and Adiponectin changes with systolic and diastolic blood pressure of Men’s with high blood pressure.
This research was a semi-experimental with repeated measurement method, and 10 men (age range= 37.9±2.68) with high blood pressure (systolic pressure: 140.531±0.23 and diastolic 90.71±0.05) after completing the consent form participated in this research. The subjects participated in a 12-week aerobic moderate exercise (55-70 percent of Maximum Heart Rate). Physiological markers and serum levels of Adiponectin, Paraoxonase-1 (PON-1) and Hydrogen Peroxide (H2O2) were assessed in baseline stage, fourth weeks, eighth weeks and twelfth weeks. The Liner Mixed Model was used to evaluate the association between markers.
Statistical analyses showed no significant relation between Adiponectin and PON-1 with systolic blood pressure (SBP) and diastolic blood pressure (DBP) (Respectively: P=0.150, P=0651 and P=0.165, P=0.520). However, the relationship between H2O2 with SBP and DBP (Respectively: P=0.020 and P=0.048) reported significantly.
it Seems that 12 weeks of aerobic moderate exercise leads to a reduction of blood pressure in Men’s with high blood pressure by reducing of ROS and oxidative stress.

Considering the complexity, cost, and time-consuming techniques of detecting Cryptosporidium oocysts and Giardia cysts, B. subtilits spores have been introduced as microbial indicators of these pathogens to evaluate the efficacy of disinfection studies. The present study was aimed to investigate the feasibility of B. subtilis spores inactivation using hydrogen peroxide combined with copper and silver ions. A new glutaraldehyde based compound used for surface disinfection was also tested.
In order to sporulation, vegetative bacteria were allowed to grow on a medium with insufficient nutrients, and after 5 days incubation at 37˚C, spores were washed and purified. Spore suspension was used to prepare synthetic water. Disinfection efficiency was reported as logarithmic decrease of initial spore count.
This research found that none of the disinfection compounds was able to spore inactivation in low initial concentration. The highest spore reduction efficiency was related to HP/Cu with 1.48 log inactivation, and HP/Ag compound placed in the second rank with 1.03 log reduction. Maximum spore reduction of 0.6 log was achieved when glutaraldehyde based disinfectant was used in disinfection process.
According to the results, it can be concluded that spores are very resistant even to combination of disinfectants. Spore reduction potential of the studied compounds was as follows: HP/Cu> HP/Ag> glutaraldehyde based compound.

Introduction & Surface roughness affects beauty, hygiene, plaque retention and health of the gingival adjacent to the composite restoration. Many people use bleaching agents to beautify their teeth that may lead to changes in surface roughness. This study was designed to compare the silorane and methacrylate-based composites in bleached teeth. In this experimental study 48 composite resin disks were prepared and divided into 4 groups: P90, Z250, Z250XT and Z350XT (n=12). To determine the surface roughness, surface profile measurement of the samples was performed using profilometer. Samples of each diet group underwent 35% hydrogen peroxide in office whitening (Hpmax) in three 45-minute sessions one week apart. The secondary instances of surface profile was then measured. The data collected by the Kolmogorov-Smirnov test, one-way ANOVA, Tukey test and paired t- test at a significance level of 0.05 were analyzed using spss16. There was a significant difference (P<0.05) in the surface roughness after bleaching on composite Z350XT with P90 and Z350XT with Z250. The surface roughness of all groups before and after bleaching showed a significant difference (P<0.05). The use of hydrogen peroxide 35% causes a significant increase in the surface roughness of composite P90, Z250, Z250XT and Z350XT.