4,128 research outputs found

    Copper(II)-oxaloyldihydrazone complexes: Physico-chemical studies: Energy band gap and inhibition evaluation of free oxaloyldihydrazones toward the corrosion of copper metal in acidic medium

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    AbstractA series of oxaloyldihydrazone ligands were prepared essentially by the conventional condensation reaction between oxaloyldihydrazide and different aldehydes e.g., salicylaldehyde, 2-hydroxy-1-naphthaldehyde, 2-hydroxyacetophenone and 2-methoxybenzaldehyde in 1:2M ratio. The synthesized compounds were purified to give bis(salicylaldehyde)oxaloyldihydrazone (L1), bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone (L2), bis(2-hydroxyacetophenone)oxaloyldihydrazone (L3) and bis(2-methoxybenzaldehyde)oxaloyldihydrazone (L4). All the oxaloyldihydrazones (L1–L4) and their relevant solid copper(II) complexes have been isolated and characterized by various physicochemical techniques. The identity of the synthesized compounds has been ascertained on the basis of elemental analyses, spectral (UV–Vis, IR, ESR, mass, 1H NMR), magnetism and thermal (TG) measurements. The dihydrazones coordinate to the metal center forming binuclear complexes. Upon chelation, the metal center can form a trigonal distorted octahedral structure with L1 and pseudo tetrahedral configuration with L2 & L3 & L4. The optical band gap energy for all compounds underlies the range of semiconductor materials. The investigated ligands were assayed for their corrosion inhibitive and adsorptive properties on copper surface in 1M HCl solution using weight loss technique. The results pointed out that, the ligands have a plausible inhibition toward the corrosion of copper specimen. The adsorption reaction on copper surface was found to be spontaneous first order and agreed with physical adsorption mechanism. The adsorption data fitted well to Freundlich, Langmuir and Frumkin adsorption isotherms

    Oscillation of Second-Order Nonlinear Delay Dynamic Equations with Damping on Time Scales

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    We use the generalized Riccati transformation and the inequality technique to establish some new oscillation criteria for the second-order nonlinear delay dynamic equation with damping on a time scale T(r(t)g(x(t), xΔ(t)))Δ+p(t)g(x(t), xΔ(t))  + q(t)f(x(τ(t)))=0, where r(t), p(t), and q(t) are positive right dense continuous (rd-continuous) functions on T. Our results improve and extend some results established by Zhang et al., 2011. Also, our results unify the oscillation of the second-order nonlinear delay differential equation with damping and the second-order nonlinear delay difference equation with damping. Finally, we give some examples to illustrate our main results

    Prophylactic use of carvedilol to prevent ventricular dysfunction in patients with cancer treated with doxorubicin

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    Objective: Deterioration in ventricular function is often observed in patients treated with anthracyclines for cancer. There is a paucity of evidence on interventions that might provide cardio-protection. We investigated whether prophylactic use of carvedilol can prevent doxorubicin-induced cardiotoxicity and whether any observed effect is dose related. Methods: A prospective, randomized, double-blind study in patients treated with doxorubicin, comparing placebo (n = 38) with different doses of carvedilol [6.25 mg/day (n = 41), 12.5 mg/day (n = 38) or 25 mg/day (n = 37)]. The primary endpoint was the measured change in left ventricular ejection fraction (LVEF) from baseline to 6 months. Results: LVEF decreased from 62 ± 5% at baseline to 58 ± 7% at 6-months (p = 0.002) in patients assigned to placebo but no statistically significant changes were observed in any of the 3 carvedilol groups. At 6 months, only one of 116 patients (1%) assigned to carvedilol had an LVEF < 50% compared to four of the 38 assigned to placebo (11%), (p = 0.013). No significant differences were noted between carvedilol and placebo in terms of the development of diastolic dysfunction, clinically overt heart failure or death. Conclusions: Carvedilol might prevent deterioration in LVEF in cancer patients treated with doxorubicin. This effect may not be dose related within the studied range

    Case studies of six CBFM-2 water bodies

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    The case studies report on how CBFM-2 interventions have affected aquatic productivity, income, employment and livelihoods in six case study sites, Beelbhora beel cluster (Kishoreganj), Sholuar beel (Narail), Chapundaha beel (Rangpur), Hamil beel (Tangail), Kutir beel (Kishoreganj) and Dikshi beel (Pabna).

    Study of sumac extract (Rhus coriaria L.), lactic acid and thyme oil as decontaminants for shelf life extension of refrigerated rabbit meat

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    In an attempt to improve the microbiological quality and extend the shelf-life of refrigerated rabbit meat, four groups of rabbit meat from New Zealand breed were prepared, the 1st group was untreated (control), while the other three groups were treated with lactic acid 0.5 %, thyme oil 0.5 % and water extract of sumac 8 % by dipping for 1, 1 and 10 min, respectively. Then the samples were refrigerated at 2 ± 1 °C to be periodically examined for their sensory and microbiological status. The control and treated samples showed excellent overall acceptability by panellists at zero-day of examination, off odours and tastes were noticed by the day 9, 12, 9 and 15 day of storage in control (C), lactic acid (LA), thyme oil (TO) and water extract of sumac (WES) treated groups, respectively. There was no significant differences in aerobic plate counts “APC” (at p < 0.05) between treated and untreated groups at zero and 3rd day of examination, while at 6th and 9th day of refrigerated storage, the values of APC were significantly lower in LA and WES treated groups than C and TO treated groups. The APC results confirm the concept that the slowest growth rate of the total bacterial population extends the shelf life of rabbit meat. Approximately, similar pattern to that of APC was observed in the results of coliforms (MPN). The MPN values of faecal coliforms and E. coli were relatively low, which could be attributed to the preparation of rabbit samples under strict hygienic measures. The obtained results in the present study suggest that WES can be used as a decontaminant for rabbit and poultry meat at each decontamination step instead of other chemical substances which could affect the acceptability of the final product and remain some hazardous residues. Keywords: sumac, rabbit, quality, shelf life, thyme oil, lactic acid

    An Overview and Tutorials on Modeling and Simulation

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    The modeling and simulation are the most important challenges to the researcher to present the system reality and study the different metrics of it. This article provides the short overview to assist the new researchers toward their goals. With aid of differ scenarios related to an engineering domain the designers have an ability to answer critical questions about modeling and simulation

    Engineering properties of porous concrete made of sustainable aggregate

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    The effect of using different types of aggregate on engineering properties of previous concrete is experimentally evaluated in this study. For this purpose, a total of four concrete mixes are cast and tested. The main parameters studied in this study are the aggregate type (natural and recycled) and aggregate size. The recycled aggregate was provided from damaged pavement roads at Amarah city. The flexural and compressive strength, infiltration, and permeability of pervious concrete are recorded throughout the study. The results of study revealed that the mechanical and physical properties of previous concrete made of recycled aggregate confirms with the international specifications. Furthermore, the conclusions appear the ability of using recycled aggregate from damaged road pavements as aggregate for producing the pervious concrete have an acceptable engineering properties. The utilizing of recycled aggregate contributes to reduce the pollution and represent as a kind of sustainability of this type of concrete materials

    Categorization of Bacterial Pathogens Present in Infected Wounds and their Antibiotic Resistance Profile Recovered from Patients Attending Rizgary Hospital-Erbil

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    Wound infection with antibiotic-resistant bacteria can extend a patients’ debility and increase the expense of treatment in the long term; therefore, careful management of patients with wound infections is necessary to avoid complications. The usage of antimicrobial agent is a major factor in resistance development. This study aims to understand the causes of wound infections, as well as the criteria for diagnosing them for more sensible antibiotic prescribing. Samples from 269 wound patients were collected, and cultured for bacterial growth. Gram stain technique, bacterial identification via VITEK 2 compact system were investigated in this study. Gram negative bacteria accounted for 59.15% of the total isolates, while pathogenic gram positive bacteria accounted for 40.85% of total isolates. Escherichia coli and Pseudomonas aeruginosa are the dominant pathogenic gram negative bacteria in wounds, while Staphylococcus aureus, and Staphylococcus epidermidis are the dominant pathogenic gram positive bacteria. Pseudomonas aeruginosa showed 100% resistance to the majority of antibiotic tested, including Ampicillin, Amoxicillin/Clavulanic Acid, Aztreona, Ceftriaxone, and others. Staphylococcus aureus and Staphylococcus epidermidis are 100% resistant to Ampicillin, Ceftriaxone, and Cefotaxime. For more efficient antibiotic prescriptions, the causative microorganisms, and their current susceptibility patterns need to be mandated for testing before prescribing any antibiotics to patients. Prescriptions are frequently based solely on general information about the antibiotic's function, rather than on individual response variation to the pathogen and the antibiotic. Particularly when the common pathogens in this study show multidrug resistance in wounds
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