25 research outputs found

    Cloud Point Extraction and Spectrophotometric Determination of Uranium (VI) in Water Samples after Mixed Micelle-Mediated Extraction Using Chromotrope 2R as Complexing Agent

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    A rapid, selective and sensitive method for the preconcentration and determination of uranium (VI) by cloud point extraction (CPE) was developed. The method was based on the color reaction of 5.00 ng mL−1 uranium (VI) with 1.5×10−4 mol L−1 of chromotrope 2R in the presence of 0.015 mol L−1 potassi-um iodide at pH 8 in HEPES buffer and mixed micelle-mediated extraction of complex. The mixture of a nonionic surfactant (0.2 % (v/v) of (Triton X-114) and a cationic (2.0×10−4 mol L−1 of CTAB) was utilized as a suitable micellar medium for preconcentration and extraction of uranium (VI) complexes. Effect of extraction and reaction parameters was studied and optimum parameters were established. The analytical characteristics of the method (e.g. linear range, limit of detection, preconcentration and improvement factors) were obtained. Linearity was obeyed in the range of 0.2−10 ng mL−1 of uranium (VI) with a detection limit of 0.035 ng mL−1. The diverse ion effect of some anions and cations on the extraction efficiency of target ions was tested. The proposed method was successfully applied for the determination of uranium (VI) in various water samples. (doi: 10.5562/cca1922

    Study of wind waves using satellite altimetry in the coast of south-western Caspian Sea (Gilan Province)

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    576-581Waves are an important phenomena in the sea but in view of complicated nature are difficult to study. This research, with the aim of showing a primary research on satellite altimetry, studied significant wave height in offshore waters near Gilan province in the south-east of Caspian region during 2014. So wave’s data including significant wave height and wind speed were obtained in a time interval from satellite. The significant wave height data were verified with buoy significant wave height data and their graphs generated. Using wave data and SPM method, the significant wave height and wave period obtained. The contour figure of significant wave height was depicted. The comparison of satellite significant wave height data and result of SPM method by buoy data showed that the satellite data has less error than SPM method result. The result of this research has shown that the effective parameters on wind waves are formation of high and low pressure atmospheric system. The maximum value of mean altimetry significant wave height is 0.70 m in November and 0.80 m in December. The maximum of significant wave height occurs in north portion of study region. The dominate direction of waves is north-western in coasts of Gilan province

    Prevalence of metallo-beta-lactamase enzyme and patern of antibiotic resistance in Klebsiella pnomoniae isolated from patients with urinary tract infection in Qom city during 2013-2014

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    Bachground: Klebsiella pnomoniae is one of the most important etiologic agents of urinary tract infection (UTI). An increasing occurrence of antimicrobial resistance among uropathogenic bacterial isolates has complicated the treatment process. The aim of this study was to determine antibiotic susceptibility patterns and prevalence of the metallo-beta-lactamase enzyme of K. pneumoniae isolates collected from UTI. Materials and Methods: This cross-sectional study was conducted on patients with complicated UTI reffered to hospitals in Qom city, Iran. A total of 1807 culture positive samples of pathogens were collected from the patients, among which 457 isolates were K. pneumoniae. The isolates were tested for antimicrobial susceptibility by the disc-diffusion method recommended by the guidelines of Clinical and Laboratory Standards Institute (CLSI 2013). In addition, the dubble disk synergy test was used to detect the K. pneumoniae isolates of metallo-beta-lactamase enzyme. Results: The prevalence of UTI infection due to K. pneumoniae was 25.3. Among 1807 positive urine cultures, 62.4 were from females and 37.6 from males. Results of antimicrobial susceptibility showed that the highest antibiotic resistance was seen for trimetoprium-sulfametoxazole (98.5) and the lowest resistance levels were seen for amikacin (9.4), meropenem (22.8) and imipenem (25.6). The results of the imipenem-EDTA combined disk showed that 93.2 imipenem resistance isolates were positive for the metallo-beta- lactamase enzyme. Conclusion: Carbapenem resistance and production of the metallo-beta-lactamase enzyme in K. pneumoniae uropathogenic are increasing. However, amikacin is still effective against these bacterial infections and its effectiveness should be maintained

    Detection of VIM-1 and IMP-1 genes in Klebsiella pneumoniae and relationship with biofilm formation

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    Klebsiella pneumoniae is an important human pathogen that is considered in recent years due to nosocomial infections resistant to treatment as well as the ability to form biofilms particularly in patients with urinary tract infection in ICU or hospital. The aim of this study was to evaluate the prevalence of VIM1, IMP1 genes and their ability to form biofilm in K. pneumoniae strains isolated from patients with urinary tract infection. In the study, using culture and biochemical methods, 1807 K. pneumoniae samples were isolated from patients with urinary tract infection hospitalized or referred to hospitals in Qom in 2013–2014. For isolation of MBL producing isolates, Double Disk Synergy Test (DDST) was used. Then MBL positive isolates were examined for the presence of VIM1, IMP1 genes using PCR method. Furthermore, all strains were investigated for biofilm formation by phenotypic microplate method. From 3165 urine samples cultured, 1807 isolates of K. pneumoniae were isolated and 109 strains (93.2%) were positive for MBL enzymes production. PCR results showed that the prevalence of VIM1 and IMP1 genes are 15.6 and 6.4%, respectively. The Phenotypic method indicated that 91.2% of isolates formed biofilm. Biofilm formation in K. pneumoniae isolates is high and there is a significant relationship between strong biofilm formation and prevalence of VIM1 and IMP1 genes. Also due to the presence of MBL genes in K. pneumoniae and horizontal transfer of genes to other bacteria, and to control the indiscriminate use of antibiotics, the hospital infection control methods must be considered

    Detection of VIM-1 and IMP-1 genes in Klebsiella pneumoniae and relationship with biofilm formation

    Get PDF
    Klebsiella pneumoniae is an important human pathogen that is considered in recent years due to nosocomial infections resistant to treatmentas well as the ability to form biofilms particularly in patients with urinary tract infection in ICU or hospital. The aim of this study was to evaluate the prevalence of VIM1, IMP1 genes and their ability to form biofilm in K. pneumoniae strains isolated from patients with urinary tract infection. In the study, using culture and biochemical methods, 1807 K. pneumoniae samples were isolated from patients with urinary tract infection hospitalized or referred to hospitals in Qom in 2013Ăąïżœïżœ2014. For isolation of MBL producing isolates, Double Disk Synergy Test (DDST) was used. Then MBL positive isolates were examined for the presence of VIM1, IMP1 genes using PCR method. Furthermore, all strains were investigated for biofilm formation by phenotypic microplate method. From 3165 urine samples cultured, 1807 isolates of K. pneumoniae were isolated and 109 strains (93.2) were positive for MBL enzymes production. PCR results showed that the prevalence of VIM1 and IMP1 genes are 15.6 and 6.4, respectively. The Phenotypic method indicated that 91.2 of isolates formed biofilm. Biofilm formation in K. pneumoniae isolates is high and there is a significant relationship between strong biofilm formation and prevalence of VIM1 and IMP1 genes. Also due to the presence of MBL genes in K. pneumoniae and horizontal transfer of genes to other bacteria, and to control the indiscriminate use of antibiotics, the hospital infection control methods must be considered. © 201

    Cloud Point Extraction and Spectrophotometric Determination of Uranium (VI) in Water Samples after Mixed Micelle-Mediated Extraction Using Chromotrope 2R as Complexing Agent

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    A rapid, selective and sensitive method for the preconcentration and determination of uranium (VI) by cloud point extraction (CPE) was developed. The method was based on the color reaction of 5.00 ng mL−1 uranium (VI) with 1.5×10−4 mol L−1 of chromotrope 2R in the presence of 0.015 mol L−1 potassi-um iodide at pH 8 in HEPES buffer and mixed micelle-mediated extraction of complex. The mixture of a nonionic surfactant (0.2 % (v/v) of (Triton X-114) and a cationic (2.0×10−4 mol L−1 of CTAB) was utilized as a suitable micellar medium for preconcentration and extraction of uranium (VI) complexes. Effect of extraction and reaction parameters was studied and optimum parameters were established. The analytical characteristics of the method (e.g. linear range, limit of detection, preconcentration and improvement factors) were obtained. Linearity was obeyed in the range of 0.2−10 ng mL−1 of uranium (VI) with a detection limit of 0.035 ng mL−1. The diverse ion effect of some anions and cations on the extraction efficiency of target ions was tested. The proposed method was successfully applied for the determination of uranium (VI) in various water samples. (doi: 10.5562/cca1922
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