405 research outputs found

    Metabolism of profenofos to 4-bromo-2-chlorophenol, a specific and sensitive exposure biomarker.

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    Profenofos is a direct acting phosphorothioate organophosphorus (OP) pesticide capable of inhibiting β-esterases such as acetylcholinesterase, butyrylcholinesterase, and carboxylesterase. Profenofos is known to be detoxified to the biologically inactive metabolite, 4-bromo-2-chlorophenol (BCP); however, limited data are available regarding the use of urinary BCP as an exposure biomarker in humans. A pilot study conducted in Egyptian agriculture workers, demonstrated that urinary BCP levels prior to application (3.3-30.0 μg/g creatinine) were elevated to 34.5-3,566 μg/g creatinine during the time workers were applying profenofos to cotton fields. Subsequently, the in vitro enzymatic formation of BCP was examined using pooled human liver microsomes and recombinant human cytochrome P-450s (CYPs) incubated with profenofos. Of the nine human CYPs studied, only CYPs 3A4, 2B6, and 2C19 were able to metabolize profenofos to BCP. Kinetic studies indicated that CYP 2C19 has the lowest Km, 0.516 μM followed by 2B6 (Km=1.02 μM) and 3A4 (Km=18.9μM). The Vmax for BCP formation was 47.9, 25.1, and 19.2 nmol/min/nmol CYP for CYP2B6, 2C19, and 3A4, respectively. Intrinsic clearance (Vmax/Km) values of 48.8, 46.9, and 1.02 ml/min/nmol CYP 2C19, 2B6, and 3A4, respectively, indicate that CYP2C19 and CYP2B6 are primarily responsible for the detoxification of profenofos. These findings support the use of urinary BCP as a biomarker of exposure to profenofos in humans and suggest polymorphisms in CYP 2C19 and CYP 2B6 as potential biomarkers of susceptibility

    Functionality of Inorganic Nanostructured Materials onto Wool Fabric

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    Silver nanoparticles (AgNPs) were prepared through chemical reduction method and characterized by UV-Vis absorption spectra to examine its formation with different AgNO3 and sodium borohydride concentrations and by transmission electron microscope (TEM) to evaluate its particle size and size distribution. The wool fabric was first treated separately with AgNPs and titanium dioxide nanoparticles (TiO2NPs) and then dyed with C.I. Acid Orange 74 (AO74). The dye uptake of pre-treated wool fabric with nanoparticles was compared to conventional dyeing of wool. The existence of AgNPs and TiO2NPs on wool fabric during acid dyeing increases the dye uptake up to 27 and 39%, respectively. The dyeing kinetic of wool fabric was positively affected by treating with AgNPs and TiO2NPs. Also, the activation energy of AO74 diffusion was calculated before and after NPs-treatment that confirms the physicsorption dyeing process. The NPs-treatment leads to produce a wool fabric with excellent antibacterial and photocatalytic properties for TiO2NPs-treated wool fabric and very good antibacterial and good photocatalytic properties for AgNPs-treated wool fabric. In addition, NPs-treatment has no adverse effects on fastness properties of the functionalized dyed wool fabric. Keywords: Silver nanoparticles, Titanium dioxide nanoparticles, Wool, Acid dyeing

    Reliability assessment for electrical power generation system based on advanced Markov process combined with blocks diagram

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    This paper presents the power generation system reliability assessment using an advanced Markov process combined with blocks diagram technique. The effectiveness of the suggested methodology is based on HL-I of IEEE_EPS_24_bus. The proposed method achieved the generation reliability and availability of an electrical power system using the Markov chain which based on the operational transition from state to state which represented in matrix. The proposed methodology has been presented for reliability performance evaluation of IEEE_EPS_24_bus. MATLAB code is developed using Markov chain construction. The transition between probability states is represented using changing the failure and repair rates. The reduced number of generation system are used with Markov process to assess the availability, unavailability, and reliability for the generation system. Additionally, the proposed technique calculates the frequency, time duration of states, the probability of generation capacity state which get out of service or remained in service for each state of failure, and reliability indices. A considerable improvement in reliability indices is found with using blocks diagram technique which is used to reduce the infinity number of transition states and assess the system reliability. The proposed technique succeeded at achieving accurate and faster reliability for the power system

    Some properties of skew Hurwitz series

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    In this paper we show that, if R is a ring and σ an endomorphism of R, then the skew Hurwitz series ring T = (HR, σ ) is an n-clean ring if and only if R is an n-clean ring. Moreover, if R is an integral domain and a torsion-free Z-module, then T = (HR, σ ) is a Prufer domain if and only if R is a field. Also, we investigate when the ring T = (HR, σ ) is g(x)-clean, (n, g(x))-clean and a Neat ring

    Health promotion, disease prevention and periodic health checks: perceptions and practice among family physicians in eastern Mediterranean region

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    Introduction: The aim of this study was to identify the current practices and perceptions of family physicians regarding health promotion, disease prevention including periodic screening and health checks in Eastern Mediterranean Region. Methods: A multi-country cross-sectional study was conducted in six countries of EMR, from September 2014 to March 2015. Family Physicians who were currently practicing in different countries of EMR were invited to participate in the study through email. A pre-tested structured questionnaire was used for data collection. Data was entered and analyzed on SPSS 19 and logistic regression analysis was performed. Results: A total of 100 physicians data was included in the final analysis. The majority were female physicians (76%): 63% were 25 to 35 years of age. Approximately 53% of Family physicians always recommend periodic screening and health checks to their patients. The common screening question asked to patients in medical history was related to their blood pressure (86%). Almost all (99%) of the Family physicians believe they should conduct periodic health checks. Those who had postgraduate training in Family Medicine (OR: 0.5; 95% CI: 0.39-1.67) and attended CME sessions regularly (OR: 0.11; 95% CI: 0.01-0.93), are more likely to recommend periodic screening and health checks to their patients. Conclusion: Periodic screening and health check is an important strategy to prevent disease and maintain health. It is an underutilized practice and a great need exists for its implementation in family practice

    RURAL WOMEN ADOPTION OF ENVIRONMENTAL PRACTICES IN MENUFIYA GOVERNORATE

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    This study aimed basically at identifying the level of rural women adoption of environmental practices in Menufiya Governorate. This main obective was achieved throw the followinge sub-objectives : determining the environmental knowledge level of rural women, identifying the dgree of rural women application of environmental practices, determining the factors which correlated  with each of the environmental knowledge level and dgree of rural women application of  environmental  practiece. The study was carried out in two villeges in Menufiya Governorate, the first villege was Monshiat Bakhaty which belongs to Shebien Elkom district and the sconede villege was Sahel Elgawaber which belongs to El shohadaa district. 100 rural women were selected randomly from each village. The study findings were: the environmental knowledge level was high as 83.5% from respondents. About 47% from respondents were applying the environmental practices. There were four independent variables (social participation, culturel cosmoplitness, geographical cosmoplitness, age) explained together 16.3 % of the total variance of the environmental knowledge level. There were six independent variables (family monthly incom, environmental situation at the village, cultural cosmoplitness, family education, geographical cosmoplitness, environmental knowledge) explained together 55.5% of the total variance of the environmental application dgree

    PS-Modules over Ore Extensions and Skew Generalized Power Series Rings

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    A right R-module MR is called a PS-module if its socle, SocMR, is projective. We investigate PS-modules over Ore extension and skew generalized power series extension. Let R be an associative ring with identity, MR a unitary right R-module, O=Rx;α,δ Ore extension, MxO a right O-module, S,≤ a strictly ordered additive monoid, ω:S→EndR a monoid homomorphism, A=RS,≤,ω the skew generalized power series ring, and BA=MS,≤RS,≤, ω the skew generalized power series module. Then, under some certain conditions, we prove the following: (1) If MR is a right PS-module, then MxO is a right PS-module. (2) If MR is a right PS-module, then BA is a right PS-module
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