جستجوی مقالات مرتبط با کلیدواژه « o3 » در نشریات گروه « پزشکی »

Olive mill wastewater (OMW) is characterized by its high organic content and refractory compounds. The aim of this study was to evaluate and compare the efficiency of UV/O3 and UV/ acetylacetone (UV/AcAc) processes for treatment of pretreated OMW by coagulation/microfiltration (C&M) process.

In this study, a laboratory-scale UV plug flow reactor with ancillary equipment was fabricated. The experimental factors including initial pH (5-9), O3 dosages (1.5-4.5 g/h), and AcAc concentrations (0.01-0.03 M) were measured. For both processes, a reaction time of 120 min was considered. The effect of these variables on removal of wastewater contaminants including BOD, COD, TSS, turbidity, phenol, oil, and grease were investigated.

Results showed that raw OMW has a high load of pollutants and very low biodegradability (BOD5/COD = 0.12). In UV/O3 process, the optimal conditions were obtained at pH 8 and ozone injection at 4 g/h. The combined C&M-UV/O3 process removed 78.75% COD, 46.66% BOD5, 90.88% total phenol, 91.78% TSS, 99.14% oil and grease, and 98.38% turbidity, with promotion of BOD5/ COD from 0.12 to 0.33. In UV/AcAc process, the optimal conditions were achieved at pH 5 and AcAc concentration of 0.03 M. The combined C&M-UV/AcAc process removed 58.75% COD, 67.58% BOD5, 38.03% total phenol, 83.50% TSS, 93.65% oil and grease, and 95.00% turbidity, with promotion of BOD5/ COD from 0.12 to 0.22.

The results showed that the UV/O3 process is completely superior to the UV/AcAc process for removal of OMW contaminants, as well as promoting the biodegradability of OMW.

Matrix metalloproteinase-13 (MMP-13) and activin receptor-like kinase 5 (ALK5) are considered as important factors contributing to knee osteoarthritis (OA) pathogenesis. Here, we compared therapeutic effects of mesenchymal stem cells (MSCs), ozone and exercise training alone and combined on expression of MMP-13 and ALK5 in rats with knee OA.

Knee OA was induced by a surgical method. Rats with OA were then randomly divided into several groups, including model, MSCs, ozone, exercise, MSCs + ozone, MSCs + exercise, ozone + exercise and MSCs + ozone + exercise groups. Expression of MMP-13 and ALK5 genes was evaluated using RT-PCR. Data were analyzed using SPSS software at significance of 0.05.

Expression of MMP-13 and ALK5 differed significantly between the study groups (P<0.0001). Knee OA was significantly associated with overexpression of MMP-13 and ALK5 in the cartilage tissue of rats with knee OA. Combined therapy with MSCs, ozone and exercise significantly decreased the expression of MMP-13 and ALK5 in the cartilage of rats with OA (P<0.001). Although MSCs, ozone and exercise training were effective to mitigate expression of MMP-13 and ALK5 genes, ozone therapy was more effective compared to the other two therapies.

Although ozone, MSCs and exercise training alone could decrease the expression of MMP-13 and ALK5 genes, combined therapy with MSC, ozone and exercise is more effective.

Knee osteoarthritis (OA) is a common type of articular disorder worldwide. Interleukin 10 (IL-10) and tumor necrosis factor-α (TNF-α) are considered as an essential regulator contributing to inflammation and knee OA pathogenesis. In this study, effects of mesenchymal stem cells (MSCs), ozone (O3) and exercise training were considered on IL-10 and TNF-α expression in rats with knee OA. Surgical method was applied to induce knee OA in rats. OA rats were randomly divided into patient, MSCs, ozone, and exercise groups. Rats in MSCs group received intraarticularly injection of 1×106 cells/kg. Rats in ozone group received O3 at the concentration of 20μg/ml, once weekly for 3 weeks. Rats in exercise group were trained on rodent treadmill for three times per week. 48 hours after the final exercise training, cartilage tissues were isolated and expression of IL-10 and TNF-α was considered using RT-PCR. Ozone therapy significantly increased the expression of IL-10 compared to the patient (3.12-folds; p=0.031), MSCs (2.78-fold; p=0.042) and exercise (4.64-fold; p=0.034) groups. The patient group had significantly higher expression of TNF-α compared to the control (32.27-fold; p=0.000), MSCs (1.58-fold; p=0.001) and ozone (3.02-fold; p=0.000) groups. MSCs and ozone therapies significantly decreased TNF-α expression compared to the patients (p=0.001 and p=0.000, respectively) and exercise (p=0.042 and p=0.000, respectively) groups; however, ozone therapy was significantly more effective than MSCs therapy (p=0.007). Ozone therapy was significantly more effective than exercise and MSCs therapy to improve knee OA in rats.

The presence of air pollutants such as CO, NO2, SO2, O3, and PM in the ambient air mainly emitted from fossil fuels combustion has become a major health concern. The aims of this study were to estimate the attribution of NO2, SO2, and O3 in the premature deaths and prevalence of cardiovascular and respiratory diseases in Isfahan in 2013–2014.
In this study, short‑term health effects (total mortality, cardiovascular and respiratory mortality, chronic obstructive pulmonary disease, and acute myocardial infarction) of exposure NO2, SO2, and O3 on the population of Isfahan were assessed using AirQ 2.2.3 software suggested by the World Health Organization (WHO).
The result showed that from nonaccident total mortality in 2013–2014 in Isfahan, the attributable proportion related to NO2, SO2, and O3 were 1.03% (109 cases), 3.46% (365 cases), and 1.29% (136 cases), respectively. The percentage of days that people were exposed to the highest concentration of NO 2 (40–49 μg/m3), SO2 (60–69 μg/m3), and O3 (40–49 μg/m3) was 34.46%, 16.85%, and 42.74% of a year, respectively. Total mortality attributed to NO2, SO2, and O3 exposure was 0.36%, 0.79%, and 0.83%, respectively.
The concentrations of NO2 and SO2 were upper than the WHO guidelines. The Air‑Q software in spite of its limitations can provide useful information regarding the health outcome of the air pollutants. The results estimated in this study were considerable. This information can help the health authorities and policy makers to draw suitable strategies and fulfll effective emission control programs.

Volatile organic compounds (VOCs) removal like toluene is an important concern for health of humans and the environment..
In this study, the efficiency of heterogeneous catalytic ozonation process (COP) with MgO nanoparticles for toluene degradation in aqueous solutions was investigated..
Response surface methodology (RSM) using central composite design (CCD) was applied to study the interactions between critical operating factors and to find their optimum levels. Four independent factors namely pH, catalyst dosage, ozonation time and concentration of toluene were transformed to coded values and consequently a second order quadratic model was prepared for responses prediction..
The analysis of variance (ANOVA) of the toluene degradation by COP/MgO nanoparticles showed F-value of 19.53 for the quadratic model indicating that the prepared model is significant. The predicted result showed that maximum degradation of toluene (~99.99%) could be achieved at pH 12, MgO dose 0.5 g, ozonation time of 50 minutes and initial toluene concentration of 10 mg/l. The correlation coefficient (R2 = 0.9480) indicates a good correlation between the experimental and predicted values..
According to the results, COP is an efficient and rapid method for removing of toluene from aqueous solutions..

There are many communities at risk by a series of air pollution episodes. Tehran is one of the most polluted cities in the world. The presence of one or more air pollutants with a certain concentration in a particular period of time can cause several adverse effects on human and animals’ well-being that can cause much morbidity. There are several pollutants in the air but some of them can cause severe adverse effects on the lungs and air ways.
In this retrospective cross-sectional study 1958 patients with exacerbation of chronic obstructive pulmonary disease (COPD) who were admitted in the emergency department (ED) of Rasol Akram hospital between March 2004 and March 2006 entered the study. Data such as number of admissions, air pollution particles (CO, SO2, O3, NO2, PM10) according to available documents were analyzed.
From 1958 patients who enrolled in this study, 887 (53.5%) were male and 771 (46.5%) were female. According to statistical analysis, we could observe a significant correlation between the concentration of Co, PM10, So2 with ED admission rate of COPD exacerbation (P: 0.031, 0.008, and 0.001 respectively). The effect of PM10, So2 and Co was more significant respectively in logistic regression on ED admission.
There was significant correction between concentrations of air pollutants with number of ED admission for COPD exacerbation.

 This research was conducted to investigate the efficacy and feasibility of ozone-hydrogen peroxide advanced oxidation process as a post-treatment step of composting leachate treated by an anaerobic migrating blanket reactor biological treatment system. 

 Leachate samples was collected from the effluent of the biological treatment system and used in an ozone reactor after dilution. The effectiveness of the pH values (4.5-11.5), H2O2 concentrations (0.5-4 g/L), ozone doses (0.2-1 g/h) and reaction times (5-270 min) were evaluated to determine optimum operational conditions. 

 The highest removal efficiencies were achieved 72% and 79% for chemical oxygen demand (COD) and biochemical oxygen demand5 (BOD5), respectively, at pH 8.5, 2.5 g/L H 2 O 2 concentration, and 1 g/h ozone dose, during 270 min reaction time. Furthermore, results indicated that the BOD 5 /COD ratio was decreased from 0.53 to 0.4 after 270 min reaction time. 

 The O 3 /H 2 O 2 was found to oxidize preferably COD and BOD 5 of the leachate samples. In consequence, a decrease in the biodegradability of leachate was observed after oxidation treatment. The O 3 /H 2 O 2 reaction proved to be a feasible technique for the oxidation of the leachate under study, and it can be considered a suitable treatment for this type of wastewater.

In this study, we aimed to assess the association between air pollution and cerebrovascular complications in Tehran, one of the most air-polluted cities in the world, among different subgroups of patients with stroke in 2004. In this ecologic study, we calculated the daily average levels of different air pollutants including CO, NOX, SO2, O3, and PM10 and also humidity and temperature on the day of stroke and 48 hours prior to stroke in 1 491 patients admitted with the diagnosis of stroke in eight referral hospitals in different areas of Tehran. Then, we evaluated the association between the rate of stroke admissions and the level of the selected pollutants, humidity, and temperature on the day of stroke and 48 hours prior to stroke among different subgroups of patients. There was no significant association between the sameday level of the pollutants and the rate of stroke admissions, but an association was seen for their level 48 hours before stroke. These associations differed among different subgroups of age, sex, history of underlying diseases, and type of stroke. Same-day temperature had a reverse association in patients with hemorrhagic stroke and in patients without a history of heart disease or previous stroke. A direct significant association was seen for humidity level 48 hours before stroke in patients with a history of heart disease. It is inferred that air pollution has a direct association with the incidence of stroke and these association differs among different subgroups of patients. The results of this study are not time-dependant and can be generalized to different times and regions. Moreover, these results may be useful for environmental health policy makers.