1,513 research outputs found

    Fluoride removal from aqueous solution by pumice: case study on Kuhbonan water

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    The fluoride removal from synthetic water by pumice was studied at batch experiments in this study. The effect of pH, contact time, fluoride concentration and adsorbent dose on the fluoride sequestration was investigated. The optimum conditions were studied on Kuhbonan water as a case study. The results showed that with increasing of the absorbent amount; contact time and pH improve the efficiency of fluoride removal. The maximum fluoride uptake was obtained in pH and contact time 7.0 and 180 min, respectively. Also, with increasing initial concentration of fluoride in water, the efficiency of fluoride removal decreased. The obtained results in this study were matched with freundlich isotherm and pseudo second order kinetic. The maximum adsorption capacity (Qm) and constant rate were found 0.31 (mg/g) and 0.21 (mg/g.min), respectively. This study also showed that in the optimum conditions, the fluoride removal efficiency from Kuhbonan water by 2.8 mg/L fluoride was 74.64%. Eventually, pumice is recommended as a suitable and low cost absorbent to fluoride removal from aqueous solutions.Key words: Adsorption, Freundlich isotherm, Langmuir isotherm, Kuhbonan water

    The validity and reliability of autism behavior checklist in Iran

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    Objectives: The aim of this study was to evaluate the psychometric features of the Persian version of the Autism Behavior Checklist (ABC). Method: The International Quality of Life Assessment (IQOLA) approach was used to translate the English ABC into Persian. A total sample of 184 parents of children including 114 children with autism disorder (mean age =7.21, SD =1.65) and 70 typically developing children (mean age = 6.82, SD =1.75) completed the ABC. Internal consistency, test-retest reliability, concurrent and discriminant validity, and cut-off score were assessed. Results: The results of this study revealed that the Persian version of the ABC has an acceptable degree of internal consistency (.73). Test-retest comparisons using interclass correlation confirmed the instrument's time stability (.83). The instrument's concurrent validity with Gilliam Autism Rating Scale (GARS) was verified; the correlation between total scores was .94. In the discriminant validity, the autism group had significantly higher scores compared to the normal group. Receiver Operating Characteristic (ROC) analysis revealed that individuals with total scores below 25 are less likely to be in the autism group. Conclusion: The Persian version of the ABC can be used as an initial screening tool in clinical contexts

    Life Cycle Assessment of Municipal Waste Management System (Case Study: Karaj, Iran)

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    LCA has been defined as a tool for evaluating the environmental burdens and potential impacts that can be applied to municipal solid waste management systems for determine the optimum municipal solid waste (MSW) management strategy.To investigate the Waste Management system strategyof Karaj City we used LCA method. Three scenarios were defined and compared based on environmental burden include water pollution, air pollution, consumed energy and waste residues.. For each of these scenarios, an ecological indicator was achieved from checklist values. From the environmental point of view, results show that recycling is one of the best alternatives for Waste Management. Furthermore, composting has an important role in alleviating the load of pollutants and energy usage in the Waste Management system. ©JASEMKeywords: Waste Management system, LCA, Kara

    Thrombus in the Non-aneurysmal, Non-atherosclerotic Descending Thoracic Aorta – An Unusual Source of Arterial Embolism

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    AbstractIntroductionMural thrombus of the thoracic aorta is a rare clinical finding in the absence of aneurysm or atherosclerosis.MethodsThe medical records of all patients diagnosed with a thrombus of a non-aneurysmatic and non-atherosclerotic descending thoracic aorta (NAADTA) and treated by the senior author between 04/1997 and 04/2010 were reviewed.ResultsEight patients with mural thrombus of the NAADTA were identified. Arterial embolism was the main clinical finding in all cases and involved the lower extremities (n = 6), mesenteric (n = 3) or renal arteries (n = 2). Hypercoagulable disorders were present in 3 cases and a concurrent malignancy in another 3. Two patients underwent open surgery while 4 patients were treated conservatively with anticoagulation. Of the remaining 2 patients, one was treated with a thoracic stent-graft and aorto-biiliac bypass and the other one with transfemoral thrombectomy. Technical success was achieved in all surgical cases and thrombus resolution or stable disease in the conservative management group. No thrombus recurrence was observed during a mean follow-up of 49 months.ConclusionThe management of mural thrombus in NAADTA represents a challenge, especially in case of malignant disease or hypercoagulable disorder as a potential underlying pathology and should be individualized. Although no consensus exists in the literature, therapeutic anticoagulation is proposed as first-line therapy. The indication for surgical intervention results from contraindication to anticoagulation, mobile thrombus or recurrent embolism. Whenever possible, endovascular therapy should be preferred

    Efficiency of multi walled carbon nanotubes for removing Direct Blue 71 from aqueous solutions

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    Dye wastewater produced from industrial activity is usually toxic, resistant to biodegradation and persistent in the environment. The aim of this study was to evaluate the efficiency of multiwalled carbon nanotubes (MWCNTs) for decolorization of Direct Blue 71 (DB71). In this experimental study, the effect of various variables including contact time, solution pH, adsorbent dose, and initial dye concentration was evaluated in a batch reactor. The adsorption and kinetic models were evaluated to explain the adsorbed dye and dynamic reaction. The results of this study showed that the efficiency of dye removal increased, as the contact time and adsorbent dose increased, but as pH and initial dye concentration increased, removal efficiency decreased. The maximum efficiency of Direct Blue 71 removal was observed at acidic solution (pH=3), contact time of 90 minutes, adsorbent dose of 0.6 g/l and initial dye concentration of 25 mg/l. The adsorption of direct blue 71 best fitted the Langmuir isotherm (R2=0.87) and pseudo first order kinetic equation (R2=0.99). According to the results obtained, multiwalled nanotubes was offered as an effective adsorbent for removing direct blue 71. © Authors

    Detection of ISPa1328 and ISPpu21, Two Novel Insertion Sequences in the OprD Porin and bla<sub>IMP-1</sub> Gene Among Metallo-Beta-Lactamase-Producing Pseudomonas aeruginosa Isolated From Burn Patients

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    Background: Carbapenemes are a good choice for treatment of infections caused by multidrug resistant Pseudomonads aeruginosa. The emergence of carbapenem resistance has become a major problem in treatment of this organism especially among immunocompromised patients including burn patients. Objectives: The aim of this study was to investigate carbapenem-resistance mechanisms among burn patients in Tehran, Iran, during 2014 - 2015. Methods: The antibiotic resistance phenotypic test was accomplished by the Kirby Bauer disk diffusion method. The phenotypic investigation of metallo-beta-lactamase (MBL) producers was evaluated by the combined disk diffusion test (CDDT) method. The prevalence of MBL genes, including blaIMP-1 and blaVIM-1 was evaluated by polymerase chain reaction (PCR) and sequencing methods. Amplification of oprD was performed by PCR and the results of sequencing were aligned with wild-type P. aeruginosa strain PAO1. Results: A total of 100 P. aeruginosa were investigated, of which, 95 were resistance to imipenem. Out Of 95 imipenem resistant isolates,, 81 (85.2%) were MBL producers. Among all isolates, 13 strains carried the blaIMP-1 gene, whereas all of the strains were negative for the blaVIM-1 gene. Amplification of OprD porin was performed for all 100 P. aeruginosa strains. Two insertion sequences (ISs) including ISPpu21 and ISPa1328 were detected in PCR products of OprD gene, that were larger than expected. Conclusions: The prevalence of β-lactamase-producing isolates and their isolation from life-threatening infections in burn patients is increasing at an alarming rate worldwide. Also, we have identified two novel IS elements, ISPa1328 and ISPpu21, in P. aeruginosa isolates from hospitals in Tehran, Iran. In most of the isolates, insertional inactivation of oprD by ISPa1328 and ISPpu21 were associated with carbapenem resistance
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