Hydrogen production using Al-Sn alloys prepared by rapid solidification

Air pollution produced by the direct burning of fossil fuels is a serious problem. Therefore, there is a vital demand for renewable and clean fuel replacements for future energy source. Hydrogen, which exhibits high calorific value and is a clean burning product, could be the first choice in the future, as it is a good-looking fuel for fuel cells where the electric energy is directly gotten by the electrochemical reactions of hydrogen and oxygen. Rapidly solidified Al100-x-Snx alloy X= (0, 25, 55, 75 all in wt.%) was prepared using melt spinning technique at 800 ºC. The structural and microstructural evolutions of the phases have been studied using X-ray powder diffraction (XRD) and the Rietveld method. Al45Sn55 alloy shows the best volume of hydrogen generation which is (531 ml), this alloy has the highest number of grains (1096) than other prepared alloys in its surface which examined through a Scanning electron microscope (SEM) and analyzed using an SPM data visualization and analysis tool (Gwyddion 2.32). Differential thermal analysis (DTA) was used for calculating melting temperature for all prepared alloys. Melting temperature reduced from 933.47 K for Al pure to 500.95 K in Al45Sn55 alloy. Temperature dependence of resistivity had been performed for all prepared alloys. Electrical properties of prepared alloys show the decrease in volume of the unit cell V with increasing VEC, which means that the volume of the first Brillouin zone increases by increasing VEC since they are inversely proportional to each other

Antimicrobial resistance pattern and molecular epidemiology of ESBL and MBL producing Acinetobacter baumannii isolated from hospitals in Minia, Egypt

Introduction: Multidrug resistant (MDR) Acinetobacter baumanii (A. baumannii) strains have emerged as novel nosocomial pathogens threatening patients’ lives, especially in intensive-care units (ICUs). This study aims to determine the prevalence of carbapenemase genes and CTX-M-15 and the resistance pattern of carbapenemase producing isolates. Methods: A total of 530 clinical specimens were collected from patients suffering from different infections, antibiotic susceptibility test was performed using kirby-bauer disk diffusion method. ESβL production was detected phenotypically by double-disc synergy test (DDST). Carbapenemase production was tested by Modified Hodge Test (MHT). Then, these isolates were tested for MBL detection by disc potentiation test. Carbapenemase encoding genes (VIM, IMP, GIM and SPM, OXA-51, OXA-23 and OXA-143) and CTX-M-15 were tested by polymerase chain reaction (PCR). Results: Out of 530 samples, 20 bacterial isolates were identified as A. baumannii from different infectious cases, 35% of isolates were ESBL-producers. Eleven isolates were resistant to imipenem (4 isolates) and meropenem (7 isolates). All carbapenem resistant isolates were MHT positive. Nine (45%) isolates were confirmed as A. baumannii by OXA-51 (all were carbapenem resistant). Distribution of IMP, VIM, GIM and SPM, OXA-23, OXA-143 and CTX-M-15 by PCR were 55, 50, 50, 25, 35, 45 and 33% respectively. Conclusion: The high prevalence of resistance genes and the resistance pattern of the isolates indicate that the detection of ESBLs and MBLs phenotypically and genotypically with the study of the resistance pattern of the isolates is critically important for the surveillance of drug resistance in the hospital environment

Najzapadniji nalaz vrste Terapon jarbua (Forsskål, 1775.) u Sredozemnom moru: nova nezavičajna vrsta ribe u Libiji

The occurrence of the Indo-Pacific fish Terapon jarbua (Forsskål, 1775) is documented for the first time from Libya. This record represents the third and westernmost observation of the species in the Mediterranean Sea. Introduction pathway for this fish in Libyan waters and in the Mediterranean Sea in general is discussed.Nalaz indo-pacifičke vrste Terapon jarbua (Forsskål, 1775.) po prvi put je dokumentiran na području Libije. Ovaj nalaz predstavlja treće i najzapadnije opažanje ove vrste u Sredozemnom moru. U radu se raspravlja o razlozima pojavljivanja ove ribe u libijskim vodama i Sredozemnom moru općenito

Factors Associated with Patient Visits to the Emergency Department for Asthma Therapy in Jordan

This study aimed at analyzing the factors associated with patient visits to the emergency department for asthma therapy in Jordan, by attempting to answer the study questions: What are the factors associated with patient visits to the emergency department for asthma therapy in Jordan University Hospital, and king Abdullah Hospital in Jordan? And how to reduce the use of the emergency departments for asthma treatment as a major goal of asthma management? This cross-sectional study was conducted from January 2016 to June 2016 on 400 patients reporting to the ED of two hospitals (Jordan University Hospital and King Abdullah Hospital. The researchers adopted the descriptive methodology by adopting the questionnaires as the study tool and data collection

GREEN VORTEX-ASSISTED IONIC LIQUID-BASED DISPERSIVE LIQUID-LIQUID MICROEXTRACTION FOR ENRICHMENT AND DETERMINATION OF CADMIUM AND LEAD IN WATER, VEGETABLES AND TOBACCO SAMPLES

Objective: An eco-friendly, simple and sensitive vortex-assisted ionic liquid-based dispersive liquid-liquid microextraction method (VA-IL-DLLµE) has been proposed to enrich and determine trace levels of cadmium (Cd2+ ) and lead (Pb2+ ) ions in water, vegetables and tobacco samples, prior to its FAAS determination. Methods: The proposed method based on utilization of ionic liquid (IL) (1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate [HMIM][FAP]) as an extraction solvent for both ions after the complexation with 4,5-dihydroxy-3-phenylazo-2,7-naphthalenedisulfonic acid, disodium salt (Chromotrope 2R) at pH 6.5. The impact of different analytical parameters on microextraction efficiency was optimized. Results: In the ranges of 1.0–300 and 2.0-400 μg/ml, the calibration graphs were linear. The limits of detection were 0.3 and 0.6 μg/ml for Cd2+ and Pb2+ ions, respectively. The preconcentration factor was 100. The relative standard deviation (RSD %)<3.0%, which indicates the proposed method has high precision. Conclusion: The proposed VA-IL-DLLµE method was developed and applied for the estimation of Cd2+ and Pb2+ ion content in various water, vegetables and tobacco samples, and satisfactory results were obtained. The obtained recovery values showed good agreement with the certified values

Salivary PCR detection of Helicobacter pylori DNA in Egyptian patients with dyspepsia

AbstractSeveral methods are available for detecting Helicobacter pylori infection: (1) invasive methods based on gastric biopsies, (2) non invasive methods like Urea Breath Test (UBT), serology and stool antigen tests. Importance of salivary PCR in detection of H. pylori is still questionable. To evaluate the role of salivary PCR technique in detecting H. pylori gastric affection in Egyptian patients with dyspepsia and in differentiating between functional dyspepsia and acid-ulcer syndrome. This study included 60 patients with dyspepsia classified into three groups: (Group 1) patients with gastric H. pylori and ulcers or erosions (n=20), (Group 2) patients with gastric H. pylori and no ulcers or erosions and had functional dyspepsia (n=20), (Group 3) patients without H. pylori and had functional dyspepsia (n=20). All underwent upper gastrointestinal endoscopy with biopsies, rapid urease test and salivary samples for H. pylori PCR. Significant difference between the three groups regarding salivary PCR values. No significant difference between Group 1 and Group 2 but both had significant difference with Group 3, significant difference between gastric H. pylori positive patients (n=40) and negative ones (n=20). Salivary PCR test had sensitivity of 85%, specificity of 70% in diagnosing H. pylori. PCR value of 534000Iu/ml had best sensitivity (75%) and specificity (100%) for diagnosing H. pylori, highly significant positive correlation between H. pylori gastric affection and salivary PCR values. No significant difference between patients with acid ulcer syndrome (n=20) and those with functional dyspepsia (n=40) as regard salivary PCR mean values. Salivary PCR test showed sensitivity of 100%, specificity of 50% in differentiating between patients with acid ulcer syndrome and those with functional dyspepsia. PCR value of 440000 Iu/ml had best sensitivity (100%) and specificity (55%) in differentiating acid ulcer syndrome from functional dyspepsia with non significant. H. pylori salivary PCR may be of value in diagnosing H. pylori gastric affection and is strongly correlated with it but it is of limited value in differentiating between acid ulcer syndrome and functional dyspepsia

Selenium- and/or copper-substituted hydroxyapatite: A bioceramic substrate for biomedical applications

Atomic substitution or doping of a bioceramic material hydroxyapatite (HA) with specific ions is an appealing approach for improving its biocompatibility and activity, as well as imparting antibacterial properties. In this study, selenium- and/or copper-substituted hydroxyapatite powders were synthesized by an aqueous precipitation method and using the freeze-drying technique. The molar concentrations of constituents were calculated based on the proposed mechanism whereby selenium (Se4+) ions partially substitute phosphorus (P5+) sites, and copper (Cu2+) ions partially substitute (Ca2+) sites in the HA lattice. Dried precipitated samples were characterized using Inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR) and Field-emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDX). Accordingly, substitution of Se4+ and/or Cu2+ ions took place in the crystal lattice of HA without the formation of any impurities. The presence of sulphur (S2-) ions in the hydroxyapatite was detected by ICP-OES in all samples with copper substituted in the lattice. The cytotoxicity of the powders on osteoblastic (MC3T3-E1) cells was evaluated in vitro. Selenium substituted hydroxyapatite (SeHA), at the concentration (200 μg/mL), demonstrated higher populations of the live cells than that of control (cells without powders), suggesting that selenium may stimulate the proliferation of these cells. In addition, the copper substituted hydroxyapatite (CuHA) and the selenium and copper substituted hydroxyapatite (SeCuHA) at the concentrations (200 and 300 μg/mL) and (200 μg/mL), respectively demonstrated better results than the unsubstituted HA. Antimicrobial activity was assessed using a well-diffusion method against Streptococcus mutans and Candida albicans, and superior results has obtained with SeCuHA samples. Presented findings imply that selenium and/or copper substituted modified hydroxyapatite nanoparticles, may be an attractive antimicrobial and cytocompatible substrate to be considered for use in a range of translational applications

Autoxidation of 4-Hydrazinylquinolin-2(1H)-one; Synthesis of Pyridazino[4,3-c:5,6-c′]diquinoline-6,7(5H,8H)-diones

An efficient synthesis of a series of pyridazino[4,3-c:5,6-c′]diquinolines was achieved via the autoxidation of 4-hydrazinylquinolin-2(1H)-ones. IR, NMR (1H and 13C), mass spectral data, and elemental analysis were used to fit and elucidate the structures of the newly synthesized compounds. X-ray structure analysis and theoretical calculations unequivocally proved the formation of the structure. The possible mechanism for the reaction is also discussed

Autoxidation of 4-Hydrazinylquinolin-2(1H)-one; Synthesis of Pyridazino[4,3-c:5,6-c′]diquinoline-6,7(5H,8H)-diones

An efficient synthesis of a series of pyridazino[4,3-c:5,6-c′]diquinolines was achieved via the autoxidation of 4-hydrazinylquinolin-2(1H)-ones. IR, NMR (1H and 13C), mass spectral data, and elemental analysis were used to fit and elucidate the structures of the newly synthesized compounds. X-ray structure analysis and theoretical calculations unequivocally proved the formation of the structure. The possible mechanism for the reaction is also discussed

Autoxidation of 4-Hydrazinylquinolin-2(1H)-one; Synthesis of Pyridazino[4,3-c:5,6-c′ ]diquinoline-6,7(5H,8H)-diones

An efficient synthesis of a series of pyridazino[4,3-c:5,6-c′]diquinolines was achieved via the autoxidation of 4-hydrazinylquinolin-2(1H)-ones. IR, NMR ($^1$H and $^13$C), mass spectral data, and elemental analysis were used to fit and elucidate the structures of the newly synthesized compounds. X-ray structure analysis and theoretical calculations unequivocally proved the formation of the structure. The possible mechanism for the reaction is also discussed