256 research outputs found

    Synthesis of green thermo-responsive amphoteric terpolymer functionalized silica nanocomposite derived from waste vegetable oil triglycerides for enhanced oil recovery (EOR)

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    Despite the high efficiency of polymer flooding as a chemical enhanced oil recovery (CEOR) technique, the low thermal stability and poor salt resistance of widely applied partially hydrolyzed polyacrylamide (HPAM) limited the application of this technique in oil reservoirs at harsh reservoir conditions of high–temperature and high–salinity (HTHS). These inadequacies of HPAM, result in the urge for an environmentally friendly polymer with good viscosifying properties and a substantial effect on mobility ratio at HTHS reservoir conditions. In this research, a high oleic acid waste vegetable oil (WVO) is utilized to synthesize a novel environmentally benign, thermo-responsive amphoteric nanocomposite for EOR applications at HTHS reservoir conditions. A green route transesterification reaction has been utilized to synthesize a novel thermo-sensitive monomer from WVO. The existence of unsaturated fatty acids isolated double bonds and acryloyl functional groups in the synthesized monomer has been confirmed using different characterization methods. The reactive acryloyl double bond in the synthesized monomer has been copolymerized with acrylamide, acrylacyloxyethyltrimethyl ammonium chloride, and 2-acrylamide-2-methylpropane sulfonic acid in presence of dimethylphenylvinylsilane via free radical emulsion polymerization. The synthesized nanocomposite has been characterized by FTIR, 1H NMR, SEM, EDX, TEM, and DLS. The thermal stability of the nanocomposite has been evaluated by TGA and DTA analysis. The results indicated that nanocomposite solution exhibited a pouncing thermo-thickening behaviour and superior viscosifying properties even at an ultra-low polymer concentration of 0.04 wt.% as the temperature increased from 25 to 100 °C, with increasing salinity from 10,000 to 230,000 ppm as well as salt-free solutions. Flooding experiments demonstrated that the oil recovery factor reached 15.4 ± 0.1% using low nanocomposite concentrations of 0.04 wt.%, 22.6 ± 0.3% using nanocomposite concentrations of 0.06 wt.% and 25 ± 0.2% using 0.1 wt.% nanocomposite concentrations evaluated under hostile conditions of 100 °C and salinity of about 230,000 ppm. This research offers a new direction for the synthesis of a novel green, high molecular weight thermo-responsive nanocomposite for EOR application at extremely harsh reservoir conditions via WVO valorization

    Egyptian students’ guardians knowledge, attitude and predictors of negative attitude of epilepsy in Assiut city

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    AbstractBackgroundEpilepsy is very prevalent in Egypt, approaching 6.98 per 1000 population. This study was designed to assess the knowledge and attitudes towards epilepsy among guardians of Egyptian high school students.MethodsA cross-sectional study was made among guardians (parents/guardians) of high school students in Assiut city, Egypt. A 15-item questionnaire was self-administered by 1257 students’ guardians who were randomly selected.ResultsAll recruited parents/guardians of high school students had heard about epilepsy. Families with a patient with epilepsy (PWE) had significantly better information about epilepsy and its aetiology than other families. The predictors of negative attitudes towards PWE were: age group ranging from 40 to 49years, no work, skilled work, male sex and incorrect knowledge.ConclusionHaving a patient with epilepsy is a predictor to having greater knowledge and a better attitude towards epilepsy. However, people still have a concept that PWE are stigmatized and are different from others. Raising awareness about epilepsy and its aetiology will increase the knowledge and improve the attitudes towards PWE

    Synthesis and characterization of a novel amphoteric terpolymer nanocomposite for enhanced oil recovery applications

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    Water-soluble polymers are highly applied to increase the recovery from oil reservoirs. The application of these polymers in enhanced oil recovery (EOR) has some limitations regarding chemical, thermal and mechanical degradation at harsh reservoir condition. In this research, a novel stable terpolymer has been synthesised by preparing and grafting vinylbenzyl starch with poly (acrylamide/ acrylic acid/ acrylacyloxyethyltrimethyl ammonium chloride) in the presence of silica nanoparticles via free radical emulsion polymerization. Different stability investigations have been applied for the synthesised polymer including temperature, salinity and shear stability analyses at harsh conditions. The chemical structure of the novel polymer has been characterized using numerous methods including proton nuclear magnetic resonance (1H NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy and high-resolution transmission electron microscope (TEM). Thermal properties have been evaluated by thermal gravimetric analysis (TGA). The rheological properties have been studied at harsh reservoir conditions in terms of formation water salinity, temperature, and shear rate. The results have shown that the introduction of vinylbenzyl starch has significantly enhanced the thermal and chemical stability of the prepared polymer. Moreover, flooding experiments conducted on sandstone core have shown that the synthesised terpolymer can enhance the oil recovery up to 43% at polymer concentration of 3 g/L

    Management of citrus nematode (Tylenchulus semipenetrans) by certain plant species

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    The effect of five plant species (Tagetes erecta L., Datura stramonium L., Nerium oleander L., Ipomea palmata L. and Santolina chamaecyparissus L.) on severity of Tylenchulus semipenetrans on citrus rootstocks (Citrus sinensis, C. reticulate grafted on C. aurantium and C. sinensis grafted on C. aurantium) was investigated in greenhouse and laboratory conditions. All plant species reduced the larval population of T. semipenetrans and their effect increase as the period increase. I. palmata gave the highest percentage of reduction when intercropped with C.sinensis and C. reticulate grafted on C. aurantium 20.5 and 25% respectively. N. oleander and D. stramonium came next when intercropped with C. reticulate grafted on C. aurantium 13.5 and 11% respectively, While D. stramonium gave the highest percentage of reduction when intercropped with C. sinensisgrafted on C. aurantium. And T. erecta gave the lowest percentage of reduction when intercropped with the three rootstocks

    Double-blind randomized controlled trial of letrozole versus clomiphene citrate in subfertile women with polycystic ovarian syndrome

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    STUDY QUESTION: Would letrozole as a primary ovulation induction agent generate better pregnancy rates than clomiphene citrate (CC) in subfertile women with anovulatory polycystic ovarian syndrome (PCOS)? SUMMARY ANSWER: Participants receiving letrozole as a primary treatment achieved a significantly (P = 0.022) higher clinical pregnancy rate per patient (61.2%) compared to CC (43.0%). WHAT IS KNOWN ALREADY: According to a recent Cochrane systematic review (2014), letrozole appears to improve live-birth (LB) and pregnancy rates in anovulatory women with PCOS, compared to CC. However, the review concluded that the quality of evidence was low due to poor reporting of study methods and possible publication bias. STUDY DESIGN, SIZE, DURATION: This double-blind randomized controlled trial (RCT) included 159 participants between April 2007 and June 2014. Subjects were randomly allocated to either CC (n = 79) or letrozole (n = 80) in a 1:1 ratio. Both drugs were encapsulated to look identical. Randomization was performed in mixed blocks and stratified by patients’ BMI (<30 and 30–35 kg/m2). PARTICIPANTS/MATERIALS, SETTING, METHODS: The trial included subfertile women diagnosed with PCOS. Treatment started with one tablet (CC 50 mg, letrozole 2.5 mg) increasing to two in non-responders and continuing until pregnancy or for up to six ovulatory cycles. Non-responders were crossed over to the other treatment after a 6-week break. Cycles were initially monitored with ultrasound follicle tracking then mid-luteal serum progesterone measurement in subsequent cycles. MAIN RESULTS AND THE ROLE OF CHANCE: Amongst the 159 participants included in the intention-to-treat analysis, four women conceived before treatment and six were lost-to-follow-up. The remaining 149 participants (74 on CC and 75 on letrozole) completed at least the first treatment. Women receiving letrozole achieved a significantly (P = 0.022; absolute difference [95% confidence interval] 18% [3–33%]) higher pregnancy rate (61.%) than those on CC (43%). The median number of treatment cycles received until pregnancy was significantly (log rank P = 0.038) smaller with letrozole (4[3–5] cycles) compared to CC (6[4–7] cycles). LB rates were not statistically (P = 0.089) different between the two groups, although there was a trend towards higher rates on letrozole (48.8%) compared to CC (35.4%). After the crossover, pregnancy and LB rates on letrozole (n = 45; 28.9 and 24.4%, respectively) were not statistically (P = 0.539 and P = 0.601) different from CC (n = 31; 22.6 and 19.4%). LIMITATIONS, REASONS FOR CAUTION: One possible limitation of this trial may be the exclusion of PCOS women with BMI > 35 kg/m2, which would limit the applicability of the results in this subgroup of PCOS. However, this group of women are generally excluded from treatment in the majority of fertility centres, especially in Europe, due to the associated challenges and risks. WIDER IMPLICATIONS OF THE FINDINGS: The results of this trial are consistent with the recent Cochrane systematic review. However, with its robust design, the current RCT provides more valid and compelling evidence for the superiority of letrozole over CC as a primary ovulation induction agent in PCOS women with 40% increase in pregnancy rates and with a shorter time-to-pregnancy. Furthermore, the participants in this RCT are a good representation of subfertile PCOS population receiving fertility treatment in Europe and worldwide. The results are therefore globally generalizable for clinical practice. STUDY FUNDING/COMPETING INTEREST(S): This RCT was mainly funded by the R&D Funding Scheme of Derby Hospitals NHS Foundation Trust. The study also received funds from School of Medicine, University of Nottingham. The Trust R&D department was involved in the development of the protocol and the running of the trial. The trial was sponsored and monitored by the University of Nottingham. The authors have no conflicts of interest. TRIAL REGISTRATION NUMBER: www.Clinicaltrials.gov: NCT00478504. TRIAL REGISTRATION DATE: Registration was verified on 23/05/2007. DATE OF FIRST PATIENT’S ENROLMENT: 25/04/2007

    CONSERVATION OF THE MURAL PAINTINGS OF THE GREEK ORTHODOX CHURCH DOM E OF SAINT GEORGE, OLD CAIRO-EGYPT

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    The church of Mary Girgis (Saint George) was built by Athanasius "who also founded the Church of Saints Cyrus and John". The Church was destroyed, and all the rest of the original edifice is a room which covered by huge dome known as the Wedding Hall, dating to the 14th century. The huge dome of the wedding Hall contains several mural paintings represented Coptic arts. The dome mural paintings was darkened and severely damaged as significant detachments of the painted layer and the underneath support lost their cohesion and separated into many pieces, delamination and flaking of the ceiling painting. The most important causes for the monument state of degradation were the environmental condition such as the effects of the groundwater, the presence of salts, the humidity (active in all its forms as infiltration, capillarity and condensation) and the improper previous interventions at the structural level (fillings in the cracks with gypsum mortars). The aim of this study is to characterize the components of the pictorial surface which consists of pigments, the binding media, the plaster layer and its support and introduce the conservation project of the mural painting which was carried out at the dome "between" 2004-20013. Prior to the conservation intervention, the materials were characterized by optical microscopy, polarizing microscope, scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffraction and X-ray fluorescence. The chemical analyses have determined the nature and composition of the materials used in the painting process (mortars, pigments, binders), have identified the causes of physical and chemical altering processes of pigment layers and provided knowledge on the execution technique. The interior painting was executed according to the Byzantine technique, on a fresco plaster (intonaco) consisting of lime mortar, pigments were obtained by mixing pigments with water. After the material characterization, the conservation and restoration of the mural painting, which including cleaning, injection grouting, fixation of the paint layer, filling of the support gaps with mortar, consolidation, restoration and completion of lost parts, were carried out

    Assessment of the association of serum progranulin with autophagy in diabetic patients

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    Introduction: Progranulin (PGRN) has newly arisen as an important regulatory protein of glucose metabolism and insulin sensitivity. Progranulin expression is interrelated with lysosomal function strongly linked to autophagy pathway. We aimed to evaluate the correlation between PGRN protein and microtubule-associated protein light chain 3B (LC3B) expression level in diabetic patients. Material and methods: Blood samples of 70 type 2 diabetic Egyptian patients were provided for analysis of concentrations of serum progranulin and interleukin 6 (IL-6) using ELISA, and quantifying expression of LC3B RNA level using qPCR. A group of 20 healthy volunteers were also enrolled. Results: Serum levels of PGRN and IL-6 as well as LC3B gene expression levels were markedly higher in type 2 diabetic patients. Additionally, our study revealed a cut-off value of 18.14 ng/mL for progranulin serum level and 3.23 for LC3B expression level, with sensitivities of 83.6% and 75.4% and specificities of 83.8% and 58.3%, respectively. Circulating PGRN levels are positively correlated with body mass index (BMI), glucose concentration, and IL-6. Conclusion: Our results support the hypothesis that progranulin is introduced as a novel marker of chronic inflammatory response in type 2 diabetes that aggravates insulin resistance via activated autophagy, indicating the importance of this novel adipokine in the regulation of glucose metabolism and as a promising therapeutic target in the treatment of diabetes. Key words: diabetes; progranulin; autophagy; microtubule-associated proteins light chain 3B; interleukin

    A review on polymer flooding in enhanced oil recovery under harsh conditions

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    Polymer flooding is a commercially verified technology to enhance the recovery of residual oil from oil reservoirs. Polymers are used to increase the viscosity of the displacing phase. Accordingly, they resulted in a significant reduction in the mobility ratio between the water and oil. Due to the decrease in the mobility ratio, the sweep efficiency will significantly increase compared to water flooding. This paper aims to provide a comprehensive review on thermal and chemical stability and the rheological properties of various water-soluble polymers used in sandstone and carbonate reservoirs. The properties of conventional and novel water-soluble polymers applied in enhanced oil recovery (EOR) are discussed along with their limitations. Moreover, field and laboratory core flooding data of different water-soluble polymers are presented. This review covers current research studies on the application of polymer flooding to high-temperature and high-salinity reservoirs. It also provides recommendations for future work on synthesis of novel polymers with higher stability under harsh reservoir conditions

    Characterization and optimization of lipase activity produced by Pseudomonas monteilli 2403-KY120354 isolated from ground beef

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    A total of 56 Gram negative bacterial isolates were recovered from twenty ground beef samples and were screened for their potentiality to produce lipase. Forty four bacterial isolates were recorded as positive producers for lipase on tween as carbon source in solid medium. Also, the highly producer isolates were screened for lipase activity in submerged culture using olive oil as carbon and the most active isolate was 2043 which gave an activity of 20.0 ± 0.29 U/ml. The bacterial isolate 2403 was identified phenotypically according to Bergey’s Manual and genotypically using 16S rRNA genes analysis as Pseudomonas monteilli. Effect of some different factors on lipase activity were studied and the maximum lipase activity was achieved at reaction medium of pH 6 and incubated at 40°C for 60 min. Also, addition of Ba2+ in the reaction medium enhanced the lipase activity, while the other tested metals reduced the enzyme activity.Key words: Food contamination, lipase activity, olive oil, cultural conditions, Pseudomonas
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