145 research outputs found
Penbactam for Helicobacter pylori eradication: A randomised comparison of quadruple and triple treatment schedules in an Iranian population
Background & study aims: Selection of the best drug regimens for eradication of Helicobacter pylori infection especially in patients at risk of peptic ulcer relapses and the development of complications is challenging. This study assessed and compared the efficacy of the two common PPI based triple therapies to a quadruple therapy including PPI, metronidazole, amoxicillin and a bismuth compound in Iranian population. Patients & Methods: Three hundred and thirty patients with peptic ulcer and H. pylori infection were included in the study. Patients were randomly assigned to one of the three treatment protocols all given twice daily: (a) A 14-day quadruple therapy (OMAB group) comprising omeprazole 20. mg, metronicazole 500. mg, amoxicillin 1. g, and bismuth subcitrate 240. mg; (b) A 14-day triple regimen (OCP group) comprising omeprazole 20. mg plus clarithromycine 500. mg and penbactam 750. mg and (c) A 14-day triple regimen (OCA group) comprising omeprazole 20. mg plus clarithromycine 500. mg and amoxicillin 1. g. Cure was defined as a negative urea breath test at least six weeks after treatment. Results: The per-protocol eradication rates achieved with both OCP regimen (87.0%) and OCA treatment (90.8%) were significantly higher than the OMAB treatment protocol (56.0%); however, no significant difference emerged in eradication rates between the two triple treatment schedules. No significant differences between the groups were found in most side-effects. Conclusion: Two-week quadruple therapy showed a lower eradication rate compared to common triple treatment schedules when used as first-line eradication treatment for H. pylori infection in Iranian population. © 2012 Arab Journal of Gastroenterology
Hybrid scour depth prediction equations for reliable design of bridge piers
Numerous models have been proposed in the past to predict the maximum scour depth around bridge piers. These studies have all focused on the different parameters that could affect the maximum scour depth and the model accuracy. One of the main parameters individuated is the critical velocity of the approaching flow. The present study aimed at investigating the effect of different equations to determine the critical flow velocity on the accuracy of models for estimating the maximum scour depth around bridge piers. Here, 10 scour depth estimation equations, which include the critical flow velocity as one of the influencing parameters, and 8 critical velocity estimation equations were examined, for a total combination of 80 hybrid models. In addition, a sensitivity analysis of the selected scour depth equations to the critical velocity was investigated. The results of the selected models were compared with experimental data, and the best hybrid models were identified using statistical indicators. The accuracy of the best models, including YJAF-VRAD, YJAF-VARN, and YJAI-VRAD models, was also evaluated using field data available in the literature. Finally, correction factors were implied to the selected models to increase their accuracy in predicting the maximum scour depth
Evaluation of Antioxidant and Antimicrobial Properties of Nanoemulsion of Citrus paradisi Essential Oil Against Pathogenic Microorganisms: In Vitro Study
Introduction
Oxidation reactions and microorganisms’ activity are considered as the most important factors affecting the quality of food products. Recently, in the light of the inefficiency of some chemical preservatives against microorganisms and the presence of toxic residues in food products, the use of natural antimicrobials and antioxidants has been increased. Natural antimicrobial compounds have the potential to control microbial contamination and reduce the use of antibiotics. Plant essential oils are natural compounds with the potential to be used as active ingredients in the food, pharmaceutical, and cosmetic industries. Various studies have shown that essential oils have antifungal, antibacterial, antiviral, and antioxidant activity. The essential oils are considered as superb preservatives with various biological functions. Essential oils are generally recognized as safe product (GRAS) which can be used as an alternative to synthetic additives.
Grapefruit (Citrus paradisi) peel and fruit contain active ingredients such as acids, flavonoids, vitamin C, and potassium, and its essential oil is composed of terpenic hydrocarbons, such as citral, limonene, citronelal, and geraniol. Although plant essential oils have antimicrobial and antioxidant properties, one of the main problems of these natural compounds is their high volatility and instability. In this context, nanoemulsion formulations are frequently used to increase the stability and efficiency of these biologically active compounds. This study is therefore aimed to nanoemulsifying the grapefruit essential oil and evaluate its antioxidant and antimicrobial properties.
Materials and Methods
β-carotene, linoleic acid, ABTS (2,2’-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), and DPPH (2,2-diphenly-1-picrylhydrazyl) were purchased from Sigma-Aldrich Co. (USA). Mueller Hinton Broth (MHB) and Mueller Hinton Agar (MHA) were supplied from Merck Co. (Darmstadt, Germany). Grapefruit peel was dried at ambient temperature and then powdered. The obtained powder was then transferred to a Clevenger device containing 750 ml of distilled water to perform the distillation extraction (3 h). The resulting grapefruit essential oil was stored at 4 °C until use. Grapefruit essential oil was prepared using the hydrodistillation method, and then nanoemulsified. The antioxidant activity of the nanoemulsified essential oil was investigated by DPPH and ABTS radical scavenging activity and beta-carotene/linoleic bleaching test. The nanoemulsified essential oil or methanolic (control) was mixed with DPPH solution and the mixture was then stored at ambient temperature for 30 min, in a dark place. The control sample was prepared by methanol. The absorbance of the samples was measured at 517 nm. To determine the ABTS-RS activity, the nanoemulsified essential oil was briefly charged with methanolic ABTS radical cation solution and the resulting mixture was left at room temperature for 30 min. Afterward, the absorbance was read at 734 nm. A spectrophotometric method was applied to monitor β-carotene/linoleate solution bleaching in the presence of the nanoemulsified essential oil. To do this, the absorbance of the solution was recorded at 490 nm after 120 min against the control sample at time zero and after 120 min. Antibacterial effect of the grapefruit essential oil nanoemulsion was also evaluated against Escherichia coli ATCC 25922, Salmonella typhi ATCC 6539, Pseudomonas aeruginosa ATCC 27853, Listeria innocua ATCC 33090, Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 14579, Bacillus subtilis ATCC 23857, Streptococcus pyogenes ATCC 19615, and Staphylococcus epidermidis ATCC 12228, based on disk diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum bactericidal concentration.
Results and Discussions
The results showed that the nanoemulsion of grapefruit essential oil had a remarkable antioxidant effect of 42.27 mg/ml, 33.27 mg/ml and 54.54%, respectively, based on DPPH, ABTS, and beta-carotene-linoleic acid bleaching tests. According to disk diffusion agar and well diffusion agar results, the lowest inhibition zone was related to E. coli and the highest inhibition zone was observed in L. innocua. The minimum inhibitory concentration for L. innocua and S. aureus (the most sensitive bacteria) was 25 mg/ml, and E. coli, S. typhi, and P. aeruginosa had the highest inhibitory concentration. Also, the lowest bactericidal concentration was related to L. innocua and S. aureus bacteria and the highest concentration was observed for E. coli, S. typhi and P. aeruginosa. The nanoemulsified essential oil generally exhibited greater antibacterial activity against Gram-positive species. This could be mainly due to the difference in the cell wall composition of Gram-positive bacteria in comparison to Gram-negative; Gram-positive bacteria have a thicker mucopeptide layer in their cell wall, while Gram-negative bacteria have only a thin layer of mucopeptide and the wall structure is mainly composed of lipoprotein and lipopolysaccharide, thereby leading to a higher resistant to antibacterial agents According to the results, grapefruit essential oil nanoemulsion can be used as a natural antioxidant and antimicrobial agent to control oxidation reactions and the growth of spoilage and pathogenic microorganisms
Sensorineural deafness and male infertility: A contiguous gene deletion syndrome
Background: Syndromic hearing loss that results from contiguous gene deletions is uncommon. Deafness-infertility syndrome (DIS) is caused by large contiguous gene deletions at 15q15.3. Methods: Three families with a novel syndrome characterised by deafness and infertility are described. These three families do not share a common ancestor and do not share identical deletions. Linkage was established by completing a genome-wide scan and candidate genes in the linked region were screened by direct sequencing. Results: The deleted region is about 100 kb long and involves four genes (KIAA0377, CKMT1B, STRC and CATSPER2), each of which has a telomeric duplicate. This genomic architecture underlies the mechanism by which these deletions occur. CATSPER2 and STRC are expressed in the sperm and inner ear, respectively, consistent with the phenotype in persons homozygous for this deletion. A deletion of this region has been reported in one other family segregating male infertility and sensorineural deafness, although congenital dyserythropoietic anaemia type I (CDAI) was also present, presumably due to a second deletion in another genomic region. Conclusion: We have identified three families segregating an autosomal recessive contiguous gene deletion syndrome characterised by deafness and sperm dysmotility. This new syndrome is caused by the deletion of contiguous genes at 15q15.3
Using sterile insect technique against Carob moth, Ectomyelois ceratoniae (Zeller) (Lep.: Pyralidae), in Yazd province, Iran
Carob moth, Ectomyelois ceratoniae (Zeller) (Lep.: Pyralidae), is the most important pest of pomegranate fruit in Iran where the cryptic activity of its larva makes the application of insecticides practically impossible. In this research, we evaluated the viability of the sterile insect technique against the carob moth in two isolated regions in Yazd province (Aqda and Mehriz). The mass rearing of the pest was performed in clean rooms on artificial diet under environmental conditions, 29±1 ºC and 75±5 %RH applying 165 Gy gamma ray as sterilizing doze. The sterile insects were released periodically in Aqda orchards (45 hectares) and in Chah Sheida (12 hectares) in Mehriz between March and November 2015. The infestation rate of carob moth in Aqda and Mehriz significantly reduced, in both target regions and control areas, by 12.27% and 44.02%, as well as 12.06% and 50.11%, for Aqda and Mehriz, respectively. It was concluded that periodical release of sterile carob moths can effectively lower the density of pest population and its economic loss on the harvest
Techno-economic assessment of CO2 quality effect on its storage and transport: CO2QUEST: An overview of aims, objectives and main findings
This paper provides an overview of the aims, objectives and the main findings of the CO2QUEST FP7 collaborative project, funded by the European Commission and designed to address the fundamentally important and urgent issues regarding the impact of the typical impurities in CO2 streams captured from fossil fuel power plants and other CO2 intensive industries on their safe and economic pipeline transportation and storage. The main features and results recorded from some of the unique test facilities constructed as part of the project are presented. These include an extensively instrumented realistic-scale test pipeline for conducting pipeline rupture and dispersion tests in China, an injection test facility in France to study the mobility of trace metallic elements contained in a CO2 stream following injection near a shallow-water qualifier and fluid/rock interactions and well integrity experiments conducted using a fully instrumented deep-well CO2/impurities injection test facility in Israel. The above, along with the various unique mathematical models developed, provide the fundamentally important tools needed to define impurity tolerance levels, mixing protocols and control measures for pipeline networks and storage infrastructure, thus contributing to the development of relevant standards for the safe design and economic operation of CCS
Carbon capture: Whole system experimental and theoretical modeling investigation of the optimal CO<inf>2</inf> stream composition in the carbon capture and sequestration chain
Rapid increase in emissions of greenhouse gases (GHGs) has become a major concern to the global community. This is associated with the rapid growth in population and corresponding increase in energy demand. Combustion of fossil fuels accounts for the majority of CO2 emissions. Coal is used mostly for electricity generation, for instance, about 85.5% of coal (produced and imported) in the United 459Kingdom was used for electricity generation in 2011 [1]. Coal-fired power plants are therefore the largest stationary source of CO2
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