Production of Sn02 nano-particles by hydrogel thermal decomposition method

SnO2 is an important functional material having a wide range of applications in gas sensors and optoelectronic devices. There is a great interest for finding new costeffective and straight-forward methods for production of these particles. In this research, hydrogel thermal decomposition method (HTDM) is used for production of high purity SnO2nano-particles. Cost effective reactants and green routs of production are the advantages of polysaccharide based hydrogel as starting material for this method. Visual observations indicated that there is very little tendency for agglomeration in the SnO2nano-particles produced by this method which can be considered as an advantage for this method over other methods for production of SnO2nano-particles. SnO2nanoparticles are also characterized by X-ray diffraction (XRD) in terms of purity and the sizes. It is found that high purity SnO2nano-particles in the size range of 25 – 36 nm can be produced by HTDM. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2068

Profil gena za virulenciju izolata bakterije Pasteurella multocida izdvojenih iz goveda i bivola

Pasteurella multocida is responsible for numerous economically relevant diseases in domestic animals worldwide. In cattle and buffaloes the organism is associated with hemorrhagic septicemia (HS) and bovine respiratory disease (BRD). The aim of this study was to investigate twelve virulence associated genes in 22 strains of P. multocida isolated from slaughtered cattle and buffaloes. The most frequently detected genes among bovine isolates were ptfA, nanH, exbBD-tonB and oma87; whereas hgbB and toxA genes occurred less frequently. Some of the adhesions, sialidases, iron acquisition and protectin proteins occurred at considerably (P<0.05) higher frequencies in bovine isolates. The prevalence of oma87, exbBD-tonB and hgbA genes from buffaloes was significant (P<0.05), whereas the prevalence of hgbB, ompH, pfhA and toxA genes was much lower. All tested strains of P. multocida contained the sodC gene and only 22.7% of them had sodA. By using the virulence gene profiles, 12 and 21 different gene combinations were identified among the strains isolated from cattle and buffaloes, respectively, of which Profile C1 was the most common, with all strains possessing toxA. Our results indicate the presence of virulence factors (VFs) in P. multocida strains isolated from the tested cattle and buffaloes. The occurrence of these factors in apparently healthy animals could possibly indicate early infection or a contained infection which did not lead to disease. Moreover, differences in the frequency of these factors may indicate variations in the pathogenicity of the organism.Pasteurella multocida odgovorna je za mnoge gospodarski važne bolesti domaćih životinja diljem svijeta. U goveda i bivola ta je bakterija povezana s pojavom hemoragijske septikemije (HS) i respiratorne bolesti. Cilj je ovog rada bio istražiti prisutnost 12 gena odgovornih za virulenciju u 22 izolata bakterije P. multocida izdvojena iz zaklanih goveda i bivola. Najčešće dokazani geni iz goveđih izolata bili su ptfA, nanH, exbBD-tonB i oma87, dok su geni hgbB i toxA bili rjeđe dokazani. Neki od adhezina, sijalidaza, proteina koji na sebe vežu slobodno željezo i zaštitnih proteina dokazani su sa znatno većom učestalošću (P<0,05) u goveđih izolata. Prevalencija gena oma87, exbBD-tonB i hgbA bila je značajno viša (P<0,05) dok je prevalencija gena hgbB, ompH, pfhA i toxA bila niža u bivoljih izolata. Svi pretraženi izolati bakterije P. multocida sadržavali su gen sodC, a samo 22,7% njih i gen sodA. S obzirom na profil gena za virulenciju, 12 različitih kombinacija ustanovljeno je među izolatima iz goveda, a 21 kombinacija među izolatima iz bivola od kojih je profil C1 bio najčešći u izolata koji su posjedovali toxA. Rezultati naznačuju prisutnost čimbenika virulencije u izolata bakterije P. multocida izdvojenih iz pretraženih goveda i bivola. Pojava tih čimbenika virulencije u klinički zdravih životinja mogla bi značiti ranu infekciju ili infekciju koja se neće klinički očitovati. Razlika u učestalosti spomenutih čimbenika također upućuje na različitost u patogenosti izolata

Influence of upstream strut on hydrogen fuel distribution inside the supersonic combustion chamber

© 2020 Hydrogen Energy Publications LLC The efficient fuel mixing in the combustion tank enhances the overall performance of scramjet. Current attempt examines the existence of the strut on the fuel mixing of the multi hydrogen jets at supersonic flow. The numerical approach was employed to visualize the 3D flow behind the strut with multi fuel-jets. The free-stream Mach is 2.2, and four multi jets released hydrogen inside the combustor with the sonic condition. The impact of jet arrangements and the total pressure ratio on the mixing effect of the strut is fully described. Our results indicate that fuel mixing and penetration improved due to the formation of the large subsonic region behind the strut. According to achieved results, the increasing jet space from 1Dj to 5Dj raises the overall mixing to 15% in our proposed model

New report of two species of black fungus gnats (Dip.: Sciaridae) from Iran

A study on the arthropods associated with Agaricales macrofungi in the western Iranian province of Kermanshah during 2010-2011 led to the discovery of two black fungus gnat species of Corynoptera perpusilla Winnertz and Bradysia ocellaris (Comstock). Both sciarid species are here reported for the first time from Iran

Ipsilateral common iliac artery plus femoral artery clamping for inducing sciatic nerve ischemia/reperfusion injury in rats: a reliable and simple method

The aim of this study was to develop a practical model of sciatic ischemia reperfusion (I/R) injury producing serious neurologic deficits and being technically feasible compared with the current time consuming or ineffective models. Thirty rats were divided into 6 groups (n = 5). Animal were anesthetized by using ketamine (50 mg/kg) and xylazine (4 mg/kg). Experimental groups included a sham-operated group and five I/R groups with different reperfusion time intervals (0 h, 3 h, 1 d, 4 d, 7 d). In I/R groups, the right common iliac artery and the right femoral artery were clamped for 3 hrs. Sham-operated animals underwent only laparotomy without induction of ischemia. Just before euthanasia, behavioral scores (based on gait, grasp, paw position, and pinch sensitivity) were obtained and then sciatic nerves were removed for light-microscopy studies (for ischemic fiber degeneration (IFD) and edema). Behavioral score deteriorated among the ischemic groups compared with the control group (p < 0.01), with maximal behavioral deficit occurring at 4 days of reperfusion. Axonal swelling and IFD were found to happen only after 4 and 7 days, respectively. Our observations led to an easy-to-use but strong enough method for inducing and studying I/R injury in peripheral nerves

A Novel Combination of Surfactant Addition and Persulfate-assisted Electrokinetic Oxidation for Remediation of Pyrene-Contaminated Soil

Effect of surfactant addition on persulfate-assisted electrokinetic remediation of pyrene-spiked soil was studied. The influence of effective factors including voltage, surfactant addition, moisture content, and persulfate concentration on the removal of initial pyrene concentration of 200 mg kg–1 were investigated. A complete pyrene removal was observed for voltage of 1 V cm–1, saturated conditions, Tween 80 concentration of 20 mL kg–1, and persulfate concentration of 100 mg kg–1 after 24 h, corresponding to pyrene mineralization of 61 %, based on TPH analysis. The experimental results were best fitted with pseudo-first-order kinetic model with correlation coefficient of 0.968 and rate constant of 0.191 min−1. The main intermediates of pyrene degradation were benzene o-toluic acid, acetic, azulene, naphthalene and decanoic acid. Finally, an unwashed hydrocarbon- contaminated soil was subjected to persulfate-assisted electrokinetic remediation, and a TPH removal of 38 % was observed for the initial TPH content of 912 mg kg–1, under the selected conditions. This work is licensed under a Creative Commons Attribution 4.0 International License

Small palladium islands embedded in palladium-tungsten bimetallic nanoparticles form catalytic hotspots for oxygen reduction

The sluggish kinetics of the oxygen reduction reaction at the cathode side of proton exchange membrane fuel cells is one major technical challenge for realizing sustainable solutions for the transportation sector. Finding efficient yet cheap electrocatalysts to speed up this reaction therefore motivates researchers all over the world. Here we demonstrate an efficient synthesis of palladium-tungsten bimetallic nanoparticles supported on ordered mesoporous carbon. Despite a very low percentage of noble metal (palladium: tungsten = 1:8), the hybrid catalyst material exhibits a performance equal to commercial 60% platinum/Vulcan for the oxygen reduction process. The high catalytic efficiency is explained by the formation of small palladium islands embedded at the surface of the palladium-tungsten bimetallic nanoparticles, generating catalytic hotspots. The palladium islands are similar to 1 nm in diameter, and contain 10-20 palladium atoms that are segregated at the surface. Our results may provide insight into the formation, stabilization and performance of bimetallic nanoparticles for catalytic reactions

Acquired Epidermodysplasia Verruciformis Due to Multiple and Unusual HPV Infection Among Vertically-Infected, HIV-Positive Adolescents in Zimbabwe

We have characterized the EV-like dermatosis of acquired HIV in 4 adolescents. Multiple HPV types were isolated in skin tissue samples, including β-HPV, but also high levels of HPV 1 and 2. ARV did not improve the EV eruption

Epidemiology of childhood Guillan-Barre syndrome in the north west of Iran

<p>Abstract</p> <p>Background and aims</p> <p>This study was carried out to investigate the incidence, annual time trend and some epidemiological and clinical features of Guillain-Barre syndrome in children in the north west of Iran.</p> <p>Materials and methods</p> <p>In this population-based cross sectional research, epidemiological and clinical features of 143 cases with Guillain-Barre syndrome between 2001 and 2006 were studied. The setting of the study was Tabriz Children Medical Centre, the major University-Hospital located in Tabriz city of the East Azarbaijan province covering whole region. Data collected included age, gender, chronological information, preceding events, functional grade of motor deficit.</p> <p>Results</p> <p>The mean age (standard deviation) of subjects was 5.4 (3.6) years. The male/female ratio was 1.3. The average annual incidence rate was 2.27 per 100 000 population of 15 years children (CI95%: 1.9–2.6). The majority of cases occurred in March, July and November and the highest proportion of the syndrome was observed in winter (29 percent, P > 0.10).</p> <p>Conclusion</p> <p>The results indicated that an unexpected high incidence of Guillain-Barre syndrome has occurred in 2003 in the region. We concluded that a monitoring and surveillance system for Guillain-Barre syndrome is essential to set up in this region.</p