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Background and purpose: Çonsidering different reports on hazardous of commercial antioxidant, Ïn the recent years, researches have been focused on preparation of more effective and safer antioxidant from natural resources. Hydroquinone is a brightner compound which is used for brightening hyperpigmented region and used in cosmetic preparations. This chemical compound has poor stability, and quickly turned to brown colour in oxidation. Ïn this study, antioxidative metanolic effect of licorice extract in comparison with commercial anti oxidants was evaluated.
Materials and methods: Ëxtraction of dried root powder of licorice was performed in methanol. Ântioxidative property of the extract was compared with commercial antioxidants hydroxytoluene BHT. 0.1% hydroquinone cream compounds containing antioxidant, and our extracted material were incubated in dark at 25oc ± 0.5 and 45oc ± 0.5 for three mooths. Physical stability and percentage of hydoguinone remaining after 2 weeks and 1, 2 and 3 months were determined by ÜV spectrophotomerty at 294 nm wave length.
Results : Results of this study indicated acceleration in deterioration of hydroquinone, by increase in temperature. Ïncreasing in concentration of antioxidant caused increase in percentage of remaining hydroquinone, but increase in concentration of commercial antioxidant, particulary sodium metabisulfite by 1% and BÜT by 2% caused decline in physical stability of the compound. Ïn the third month, at 25oc and 45oc, the extracted material in all of the above mentioned concentrations, had more antioxidative property as compared with commercial antioxidants (P<0.001). Ïn the third month, the preparation contaning 0.1% 0.5%, 1% and 2% had good physical stability Çompared with 72%, 76%, 78% and 81% hydroquinone kept at 25 oc and 51%, 55%, 60% and 63% hydroquinone kept at 45oc respectively.
Çonclusion: referring to the findings of this study, it is proposed that, using of the licorice extract with concentrations of 0.5% and 1% as natural antioxidant be used in compounds sensitive to oxidation,

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Background and purpose: Since Çystoid Macular Ëdema (ÇMË) is caused by ocular inflammation after cataract surgery. Ït’s control with suitable medication is reasonable. Âim of this study was to compare a nonsteroidal topical solution (0.1 % diclofenac) to a steroidal topical solution (0.1 % betamethasone) in preventing ÇMË after extra capsular cataract surgery.
Materials and methods: Â prospective randomised double blind clinical trial was performed on patients undergoing extra capsular cataract surgery with posterior chamber lens implantation. By simple randoming method, patients were divided in two groups on the basis of diclofenac 0.1 % and betamethasone 0.1 % . Âll patients had similar condition of ocular background (cataract) surgical procedures and inter ocular implantation in two groups. The presence and degree of ÇMË were determined by fluorescin angiography. Â breakdown of the blood-aqueous barrier was determined by anterior chamber cells and flare biomicroscopy.
Results : Six weeks after surgery, ÇMË was present in 2 of 47 eyes (4.25 %) receiving diclofenac and in 12 of 50 eyes (24 %) receiving betamethasone. There was no significant difference in cellular reaction in the anterior chamber at 3 days, 1 and 6 weeks after surgery between two groups (P<0.01). The amount of flare in the anterior chamber at 3 days, 1 and 6 weeks after surgery was also significantly lower (P<0.001) in diclofenac group. Âlso extra ocular inflammation declined in diclofenac group (P<0.001).
Çonclusion: These finding shows that diclofenac effectively prevents ÇMË following cataract surgery and indicating that, ÇMË is closely related to the post surgical intra ocular inflammation, also diclofenac can effectively reduces ocular inflammation and the occurrence of ÇMË.

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Background and Purpose: To compar the efficacy of lithium carbonate &sodium valproate in treatment of bipolar children and adolescents in acute phase (mixed &mania) in 6 week treatment at Roozbeh hospital .
Materials and methods: A double-blind & randomized controlled clinical trial in 30 patient (8-18 years) for a 6 week trial .patients were diagnosed based on DSM_IV criteria through clinical interview & K_SADS .MRS & CGAS were used to measure the severity of symptoms and the level of functional impairment .patients categorized into 2 groups randomly.
Results:In both groups means of MRS decreased (at the end of 3rd&6th weeks) and there was no significant difference between two groups. Means of CGAS had significant difference between two groups at 3rd week (p

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Background and purpose:Intradialytic hypotension (IDH) is the most frequent complicationin patients receiving haemodialysis (HD) that poses most problems for patient and treatment team. The use of sodiumprofile and ultra filtration (UF) profile is one of the preventive methods that have been recently introduced. However, increased intradialytic weight gain (IDWG) has been described as the side effect of this method. The aim of thisstudy was to evaluate the effects of linear and stepwise sodium and UF profile on Intradialytic hypotension and IDWG.
Materials and methods: This was a clinical trial study and crossover design. Twenty- six stable HD patients from two dialysis centers (Ali Asghar and Alzahra Hospitals) of Esfahan Universityunderwent three treatments: (1) control, constant dialysate sodiumconcentration of 138 mmol/l with constant UF (2) linearsodium profile + UF profile (type1), a linearly decrease dialysate sodium concentration (146–138mmol/l) combination with a linearly decreaseUF rate. (3) Stepwise sodium profile + UF profile (type2), a stepwise decrease dialysate sodium concentration (146-138mmol/l) combination with a stepwise decreaseUF rate. Data were analyzed using χ2 and independent t-test in SPSS software.
Results:In this study, a total of 26 patients (14 men, and 12 females) participated. The mean age was 46/8±19 years. In each group, 78 dialysis sessions and a total of 234 dialysis sessions were analyzed. The incidence of intradialytic hypotension, while receiving an intervention, wassignificantly reduced during linear and stepwise profiles, as compared with control (P<0.05, respectively). However, there was no significant differences between profiles. IDWG did not show any changes during three group.
Conclusion: Sodium profile and UF profile modulates the dialysate sodium concentration and ultra filtration rate and also, prevents the incidence of IDH while reducing nursing intervention, without increasing IDWG. Thus, using sodium profile and UF profile groups (linear and stepwise) is recommended for the prevention of hypotension, as compared to routine method.

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Background and purpose: Nitrite is the material used in industry for storing food specially sausage and ham. Fast foods which contain high levels of nitrite are widely eaten throughout the world. Nitrite is also found in water, soil and ecosystem, and could highly influence human’s health. This study was performed to examine the histopathological effect of sodium nitrite on renal artery in rats. Materials and methods: This study included 60 adult male and female Wistar rats, divided into six groups of 10. They were examined for 60 days, and were assigned into the following groups: 175 mg/kg/day dose recipient group, 350 mg/kg/day dose recipient group and control group which absorbed nitrite through drinking water. At the end of day 60, after anesthesia blood sample was collected from the heart. The arteries were taken out of the body, then tissue sections were prepared to identify the tissue changes. The samples were stained with Hematoxilin Eozin method and thickness of intima media was measured with image tool software. In both sexes, we checked morphometric and morphologic features of the arteries, body weight changes before and after the test and blood NOx level. The data was then analyzed using SPSS ver. 17. Results: The outcome of NOx plasmatic density measurement showed that NOx level significantly increased in animal ’s blood in 175 mg/kg/day dose recipient group and 350 mg/kg/day dose recipient group compared with the control group (P≤ 0.05). Also, in both sexes the thickness of media layer decreased significantly in the 350 mg/kg/day dose recipient group. Conclusion: According to the results, nitrite in different dose could increase the amount of blood NOx and renal artery intima media thickness could reduce by 350 mg/kg sodium nitrite. Existence of nitrite in foods can cause vascular problems in consumers, therefore, it could be considered as a threatening factor in vascular system.

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Background and purpose: From many years ago denture adhesives have been used to improve denture’s performance. During the time, many new formulations have been prepared and evaluated to improve the properties of this product. In this study, the powder form of this product was prepared then in vitro and in vivo evaluations were performed. Material and Methods: To design the denture adhesive powder, sodium alginate, plantagopsyllium mucilage and sodium carboxy methyl cellulose were used as the main binding agents. Different formulations with different ratio of these three agents were prepared, then, their binding strength and duration of efficacy were evaluated in the lab. Finally, the best formulation was chosen for in vivo evaluation. Results: The study showed that prepared formulations containing sodium alginate and NaCMC with ratio of 95:5 had higher binding strength ability and duration of efficacy than artificial saliva. This formulation also had positive effect on the performance of denture during eating and speaking and also prolonged the adhesion period of denture. No significant differences were seen between this formulation and protefix in performance properties but in other properties like odor and flavor the prepared product were found better than protefix. Conclusion: This experimental study showed that the mixture of sodium alginate and NaCMC with more ratio of alginate 95:5 is a proper product to be used as a denture adhesive.

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Background and purpose: In ocular delivery the physiological constraints imposed by the protective mechanisms of the eye lead to low absorption of drugs, resulting in a short duration of the therapeutic effect. Thus using in-situ gelling systems could increase the residence time of the drug in the eye. These systems are instilled as drops into the eye and undergo a sol-to-gel transition in the cul-de-sac. The aim of this study was to formulate and evaluate an ophthalmic delivery system for diclofenac sodium (a nonsteroidal anti-inflammatory drug), based on the concept of ion-activated in situ gelation. Materials and methods: Ion-activated in situ gelling systems (sodium and calcium) consisting of sodium alginate and hydroxyl propyl methyl cellulose were prepared in different concentrations under aseptic condition. Diclofenac sodium was added after hydration. Formulations were evaluated for gelling capacity, physical stability, pH, drug content, viscosity and in-vitro drug release. Results: The clarity, pH and drug content of the developed formulation were found to be satisfactory. The developed formulation was stable and provided sustained drug release over an 8-h period. The viscosity was found to be in the range of 29 to 63 centipoise in shear rate of 20 rpm. The formulations showed pseudoplastic flow behavior. The ideal formulation showed no significant changes during a 90-day period and was found stable. Conclusion: The developed formulation can be used as an in-situ gelling vehicle to enhance ocular bioavailability and the reduction in the frequency of instillation, thereby resulting in better patient compliance.

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Background and purpose: In Situ Gel dosage forms are successfully used as drug delivery systems to control drug release and protect the medicaments from a hostile environment. The aim of this study was to formulate and evaluate in situ oral topical gels of fluconazole based on concept of pH triggered system. Materials and methods: An in situ gel system consisting of carbopol 934, hydroxypropyl methylcellulose and sodium alginate was used in different concentrations to prolong the release of fluconazole. Fluconazole was added to polymer’s solution after being hydrated. Formulations were evaluated for gelling capacity, physical stability, pH, drug content, viscosity and in vitro release. Results: The use of carbopol as in situ gel forming agent was substantiated by the property to transform into stiff gels when the pH was raised. The gelling capacity, pH and drug content of formulations were found to be satisfactory. The viscosity range was from 60 to 104 centipoise in shear rate of 20 rpm. The formulations showed pseudoplastic flow and were able to release the drug slowly. The formulations showed no significant changes in different condition during the period of 90 days and were found to be stable. Conclusion: The ideal formulation can be utilized for the sustained release property.

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Background and purpose: Sulfur is an essential element used in the amino acids cysteine and methionine. Sulfur toxicity occurs due to its high concentration and volatile compounds in the environment. In various stages of human life, sulfur contaminants cause a variety of disorders in different parts of the body including the immune system. The embryonic period is the most critical stage of life cycle, so, this study investigated the effects of sulfur intoxication in pregnant rats on serum levels of immunoglobulin in their neonates.

Materials and methods: In this experimental study, 36 adult female Wistar rats were divided into three groups: a control, experimental group I with mild poisoning and experimental group II with severe intoxication. Before and during pregnancy the experimental groups I and II received a daily dose of 500mg/kg.bw sodium sulfide dissolved in drinking water for 15 and 30 days, respectively. Blood samples were taken from male and female newborns, 40 days after birth, and the serum levels of IgG and IgM were measured using nephelometric technique. Data was analyzed in SPSS ver. 17.

Results: The results indicated a significant increase in serum levels of immunoglobulin IgG and IgM in male and female neonates with severe maternal toxicity compared to the control group (P < 0.05). On the other hand, there was no significant difference in the concentration of immunoglobulins in female newborns of all groups compared to the corresponding male group. (P>0.05)

Conclusion: Sulfur contaminants or their metabolites can cross the placental barrier during pregnancy and increase serum levels of IgG and IgM in neonates through changes in the function of fetal immune system. Furthermore, these alterations are believed to be gender independent.

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Background and purpose: Several factors are involved in caries prevention in children. One of the most effective factors is the appropriate use of fluoride. Fluoride induces its main effects in caries prevention through antibacterial effects and topical contact with enamel. In this study the inhibitory effects of sodium fluoride (NaF) and acidulated phosphate fluoride (APF) gels on cariogenic microorganisms concentrations (Streptococcus mutans and Lactobacillus) were compared using Quantitative Real-Time PCR.

Materials and methods: A single blind parallel clinical trial was performed in which plaque samples were investigated twice (before and after the use of fluoride). The plaque samples of 44 children were studied by quantitative Real Time PCR and the number of bacteria (lactobacilli and Streptococcus mutans) was counted in each sample. Then, APF gel (Fluoride 1.23% +0.98% phosphoric acid, pH 5.3) was randomly used for 22 children. All the teeth (primary and permanent) were covered with fluoride by applicator. For other children 2% NaF gel (neutral pH) were used. After the use of fluoride, the numbers of bacteria were measured again by quantitative real-time PCR. Finally, the variability of microorganisms before and after the intervention was compared. Mann-Whitney test was applied for data analysis using SPSS V.18.

Results: Significant reductions were observed in numbers of streptococcus mutans and lactobacillus after consumption of APF-gel (P<0.05).

Conclusion: The APF gel exhibited more caries-preventive effect compared to NaF gel and could be used to benefit children’s oral health.

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Background and purpose: Direct smear microscopy is the most common method of detecting tuberculosis with 70% sensitivity in best conditions, therefore, researches have always focused on improving the sensitivity of sputum smear. This study aimed at comparing the diagnostic value of sputum smear using light microscopy and fluorescence microscopy without sodium hypochlorite in patients with suspected pulmonary tuberculosis.

Materials and methods: A cross-sectional study was performed in 195 patients suspected of pulmonary tuberculosis attending Zahedan Booali Hospital who were selected via purposive sampling. Three sputum specimens were obtained from each patient and microscopic examinations were done using the Ziehl–Neelsen staining, auramine-rhodamine staining and Leuven Stein culturing. For smear microscopy, two sets of sputum smears were prepared from each sample (with and without sodium hypochlorite). Finally, the results of smear microscopy and sputum culture were compared.

Results: In direct smear using the Ziehl–Neelsen with and without sodium hypochlorite 69 (35%) and 63 (32%) patients were found positive, respectively and in auramine-rhodamine staining with and without adding sodium hypochlorite 71 (36%) and 66 (33%) cases were found positive, respectively. Fluorescent microscope with and without sodium hypochlorite increased the diagnostic value of direct smear compared to optical microscopy but this increase was not statistically significant.

Conclusion: The diagnostic value of sputum smear microscopy using fluorescent sodium hypochlorite in patients with suspected pulmonary tuberculosis was more than other diagnostic methods. 

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Background and purpose: Nitrite is used for preserving food, especially in processed meat products. Processed foods containing nitrite are highly used in many countries. This harmful substances in water, soil and ecosystem endanger the health of people. In this study, we examined the effect of sodium nitrite on liver enzymes and histological structure of the liver in streptozotocin-induced diabetic rats.

Materials and methods: In this study, 60 adult male Wistar rats were divided into six groups (n= 10 per group): a control group, experimental groups receiving 175 and 350 mg/kg/day sodium nitrite, a diabetic control group, and diabetic groups receiving 175 and 350 mg/kg/day sodium nitrite for 60 days. Diabetes was induced in rats by intraperitoneal administration of streptozotocin (65 mg/kg). Blood samples were collected after anesthesia and the serum AST, ALP, and ALT were measured. Also, liver tissues were removed to investigate the histological changes. Statistical analysis was done by one way variation and student’s ANOVA Test. P values less than 0.05 were considered significant.

Results: The AST, ALP, and ALT levels significantly increased in diabetic groups and the group receiving 175 and 350 mg/kg sodium nitrite (P< 0.05). The mean levels of AST, ALP, and ALT levels in the diabetic group receiving 350 mg/kg sodium nitrite were 239 ± 3.8, 286 ± 3.5, 162 ± 3.6, respectively.

Conclusion: The results showed that sodium nitrite can induce adverse effects on the liver, especially on the liver in diabetic rats.

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Background and purpose: Chlorophenol compounds are refractory and toxic contaminants that enter the environment as a result of industrial activities. They can contaminate water sources through leaking into the groundwater or being washed out from polluted soil. The aim of the present study was to evaluate the rate of 4-Chlorophenol (4-CP) degradation using the UV/NaPS process.

Materials and methods: In this investigation, the photochemical oxidation process was conducted in a batch type laboratory-scale photoreactor (1.5 L) equipped with a 50000  power. This study also investigated the effects of independent variables including sodium persulfate concentration (8.4-84 mmol/L), pH (3-10), 4-CP concentration (0.5.5 mmol/L), and reaction time (2-30 min) on the removal efficiency of 4-CP. The effluent concentration of 4-CP was measured by the UV-visible spectrophotometer at 280 nm wavelength. In addition, kinetic model was investigated.

Results: The optimum removal efficiency of 4-C by UV/NaPS process was 89.3% with sodium persulfate concentration of 8.4 mmol/L, pH of 5, initial 4-CP concentration of 1.5 mmol/L, and reaction time of 30 min. Moreover, 60.4% of the total organic carbon (TOC) was removed under similar condition. In addition, the data was found to follow the first-order kinetics.

Conclusion: Considering the growing use of UV radiation in water treatment processes and the considerable efficiency of UV/NaPS process in removing 4-CP, this method can be proposed for the elimination of 4-CP after performing cost-benefit analyses.

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Background and purpose: Bisphenol A is an estrogenic substance that can cause endocrine dysfunction, which extensively enters water resources due to its large use in industry. The aim of this study was to synthesis modified magnetic nanoparticles with sodium alginate and study of its efficiency for removal of Bisphenol A from aqueous solutions using heterogeneous fenton process.

Materials and methods: In present study, sodium alginate magnetic beads were synthesized by nanotechnology and chemical precipitation method and the removal of Bisphenol A was evaluated in a pilot-scale batch reactor. In addition, the effect of environmental factors, including pH, reaction time, catalyst dosage, initial concentration of Bisphenol A, and the concentration of H₂O₂ on removal efficiency of Bisphenol A was studied. The concentration of Bisphenol A in samples was measured by spectrophotometry instrument and the XRD method was applied to identify the characteristics of modified nanoparticles.

Results: In this study synthesized modified magnetic nanoparticles with sodium alginate had complete magnetism properties, and XRD analysis confirmed the presence of Fe₃O₄. The results showed that the highest removal efficiency of Bisphenol A was obtained at pH=5, reaction time= 120 min, catalyst dose= 5 g/L, and initial concentration= 20 mg/L which was about 95%.

Conclusion: According to our results, the magnetic nanoparticles modified with sodium alginate in a heterogeneous Fenton oxidation process are highly efficient in removing Bisphenol A.

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Background and purpose: In recent decades, various efforts have been made to replace synthetic materials with natural disinfectants that have less disadvantages and lead to similar or even better results. The present study was conducted to compare the effect of Artemisia aucheri and Zataria multiflora as natural disinfectants with those of Deconex and sodium hypochlorite as two industrial disinfectants on Candida albicans.
Materials and methods: This experimental study was conducted in 128 resin acrylic dentures. After the inoculation of C. albicans on each denture, they were divided into four groups, each containing 32 dentures. Deconex, Sodium hypochlorite, Artemisia aucheri, and Zataria multiflora were administered in each group in four densities (0.1, 0.01, 0.001, and 0.0001). The data were analyzed in SPSS V19 applying t-test. 
Results: The four disinfectants were applied for 10 and 60 min. Deconex showed the highest disinfection effect on samples (P<0.05). There were no significant differences between the effect of Artemisia aucheri and Zataria multiflora after 60 min and 10 min. However, it was found that the potency of Artemisia aucheri and Zataria multiflora increased after 60 min.
Conclusion: Current findings showed chemical disinfectants with higher potency in short-time intervals, compared to the natural ones. But, after a longer period of time, Artemisia aucheri and Zataria multiflora exerted similar effects as those of the synthetic disinfectants.
 

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Background and purpose: There are controversies on the association between electrolytes and Coronavirus disease 2019 (COVID-19) and its severity. Studies on these issues may help in resolving ambiguities. The purpose of this study was to assess the association between electrolyte indices and being infected with COVID-19 and developing severe symptoms using a meta-analysis.
Materials and methods: A thorough search was done in national and international electronic databases using Medical Subject Headings (MeSH) terms. Quality assessment was conducted by Newcastle-Ottawa scale (NOS) checklist. We estimated the standardized mean difference between electrolyte indices and the incident of COVID-19 infection and its severity.
Results: After screening the papers, 12 met the inclusion criteria. According to the meta-analysis results, the standardized mean differences for serum level of sodium and potassium between the dead and survived COVID-19 patients was estimated to be 0.22 (95% CI: -0.03, 0.46) and 0.14 (95% CI: -0.22, 0.50), respectively. The standardized mean differences for serum levels of sodium, calcium, and potassium between patients with severe and non-severe COVID-19 were estimated to be -0.28 (95% CI: -0.72, 0.17), -1.07(95% CI: -1.58, -0.55), and -0.10 (95% CI: -0.47, 0.27), respectively.
Conclusion: In this meta-analysis, the standardized mean difference for calcium was significantly lower in severe COVID-19 patients compared to that in patients with mild and moderate forms of the disease.

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Background and purpose: Curcumin is a natural polyphenolic compound in turmeric (Curcuma longa). Curcumin has potent free radical scavenger and antioxidant properties that could significantly reduce oxidative damage. Oxidative stress and mitochondrial dysfunction contribute to valproate sodium induced tissue damage. This study investigated the protective effects of curcumin against valproate sodium induced oxidative stress and mitochondrial toxicity in brain of rats.
Materials and methods: Male rats were exposed to sodium valproate (500 mg/kg/day, i.p.) alone, or in combination with different doses of curcumin (25, 50, and 100 mg/kg/day, i.p.) and vitamin C (100 mg/kg/day, i.p.) for eight weeks. Then, brain tissues were separated and factors associated with oxidative stress, mitochondrial dysfunction, and histopathological changes were investigated.
Results: Sodium valproate induced mitochondrial dysfunction, increased oxidative stress parameters and caused significant histopathological changes in brain tissue. Administration of curcumin attenuated the induction of oxidative damage, mitochondrial dysfunction, and histopathological changes induced by sodium valproate in brain tissue.
Conclusion: Curcumin showed protective effect against sodium valproate-induced neurotoxicity which may be attributed to its antioxidant activity. So, it can be considered as an effective supplement against oxidative stress and mitochondrial dysfunction induced by sodium valproate in brain tissue.
 

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 Background and purpose: Considering that chlorine disinfectants are one of the most common disinfectants for disinfecting water and wastewater, hospital environments, etc., and there are questions about the stability of chlorine in solutions and on surfaces. So, the purpose of this study is to investigate the effect of environmental factors on the stability of sodium hypochlorite solutions stored in different conditions.
Materials and methods: In this study, sodium hypochlorite solution was used for solution preparation. According to the number of parameters and based on the design of the experiment (DoE) and the response surface modeling (RSM) using the Box-Benken design (BBD), 29 experiments were performed. The solutions were stored in opaque plastic bottles covered with aluminum foil. The stability of solution in concentration of 0.05, 0.5 and 1% with the pHs of 5, 7.5 and 10 stored at 4, 25 and at 45°C, and the storage time of 15, 30, and 60 days was examined. The residual chlorine concentration was determined by the iodometric method according to the standard method.
Results: The results of this study showed that the chlorine stability decreases with increasing concentration of chlorine solution, increasing temperature and storage time. Solutions with neutral pH (7.5) showed less stability than acidic and alkaline solutions. Based on the experimental design and RSM using BBD, the linear effect of the temperature, pH, initial concentration and time was significant (P<0.05). There was a negative correlation between the amount of available chlorine and time.
Conclusion: This study showed that different storage conditions of sodium hypochlorite solution strongly affect the stability of its chlorine, so it is recommended to pay attention to these factors when using this solution for disinfection.

 

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Background and purpose: Patients admitted at the intensive care unit (ICU) need blood draws for chemistry analytes and arterial blood gas (ABG) analysis. Repeated blood drawing is one of the most common causes of anemia in these group of patients. Measurement of analytes only by ABG analyzer can be beneficial for preventing anemia. The aim of this study was to compare the biochemical analytes in venous and ABG samples in ICU patients.
Materials and methods: This cross-sectional study was performed in 223 patients hospitalized in the ICU. These patients undergoing ABG analysis and simultaneous venous sampling. The value of Ca, Na, K, Hct, and glucose were measured in venous samples with a laboratory auto-analyzer and in arterial samples with an ABG analyzer.
Results: The mean age of patients was 61.14±16.96 years. The mean difference between ABG and serum samples was 1.12 mEq/L for sodium, -0.29 mEq/L for potassium, -0.98 mg/dl for calcium, 0.33 mg/dl for glucose, and 4.39%% for hematocrit. In addition, 95% limit of agreement was -12.3 to 9 for sodium, -0.7 to 1.29 for potassium, -1.31 to 3.8 for calcium, -39.13 to 40.32 for glucose, and -13.5 to 8.5 for hematocrit.
Conclusion: Because of acceptable agreement for sodium, potassium, and hematocrit, ABG analyzer can be used in ICU patients and emergency situations. There is a remarkable bias between the ABG-measured and laboratory-measured calcium and glucose, so the calcium and glucose measurement by the ABG analyzer are not reliable.
 

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 Background and purpose: Human health is negatively affected by increase in concentration of carbon dioxide in indoor air due to the lack of proper ventilation. The aim of this study was to remove carbon dioxide from a closed space using sodium hydroxide nanofluid and determining the effect of absorbent concentration, carbon dioxide concentration, and titanium dioxide nanoparticles.
Materials and methods: The experiments were conducted in a closed chamber on a laboratory scale. An air suction pump was connected to the absorption reactor and the carbon dioxide measuring device was installed inside the chamber. By injecting carbon dioxide gas inside the chamber, different concentrations in the range of 500, 2000 and 5000 ppm were created. Sodium hydroxide absorbent solution at 0.1, 0.2, and 0.4% were examined. Titanium dioxide nanoparticles (0.008%) and surfactant (0.003%) were used to prepare nanofluids. The absorption fluids’ pH, electrical conductivity, and total inorganic carbon (TIC) were measured before and after carbon dioxide absorption.
Results: By using 0.4% sodium hydroxide solution containing 0.008% titanium dioxide nanoparticles, the carbon dioxide removal efficiency at 500 and 5000 ppm were 72% and 44%, respectively, that were higher than the solution without nanoparticles (20% and 10%, respectively). At 5000 ppm carbon dioxide, increasing the concentration of absorption solution from 0.1 to 0.4% doubled the removal efficiency. The average amount of total inorganic carbon (TIC) in nanofluids increased by about 20% compared to the base fluids. The average reduction of EC in nanofluid was about 25% higher than the base fluid. The average reduction in pH value was less than one unit.
Conclusion: Sodium hydroxide nanofluid containing 0.008% of titanium dioxide nanoparticles is effective in removing carbon dioxide from the air.