711 research outputs found
Nanosized Supramolecular Coordination Polymers Derived from Divalent Metal Ions, 4-Pyridylacetate and Auxiliary Ligands Containing Nitrogen and Phosphorus Donors
A series of coordination polymers of Co(II), Ni(II), Cu(II) or Cd(II) comprising 4-pyridylacetate (pya) and certain auxiliary ligands including benzimidazole (Hbzim), 1,10-phenanthroline (phen), 2,2'-bipyridine (2,2'-bipy), 2-amino-4-methylthiazole (A-Mtz), quinazole (Quz), 2,5-dimethylpyrazine (dpmz), bis(diphenylphosphino)methane (dpm), 1,2-bis(diphenylphosphino)ethane (dpe) and 1,3-bis(diphenylphosphino) propane (dpp) were prepared and characterized by spectroscopic, magnetic and thermal techniques. In these coordination polymers 4-pyridylacetate coordinates to the metal ions in a monodentate fashion through the carboxylate oxygens and/or the pyridyl nitrogen. Octahedral structures around the metal ions were suggested for all the complexes. The kinetic analyses of the thermal decomposition of the complexes were studied using the Coats-Redfern equation. The kinetic and thermodynamic parameters of the thermal decomposition were also calculated and discussed. From the X-ray powder diffraction data, the crystal parameters as well as the particle sizes (15.7-18.7 nm) of the complexes could be evaluated. Some of the compounds exhibit catalytic activity. The biological activity of the compounds was screened as well.
DOI: http://dx.doi.org/10.17807/orbital.v13i1.155
New Mixed Ligand Complexes of Ditertiary Phosphanes with Ni(II) Alkylxanthates
Mixed Iigand complexes of Ni(II) with alkylxanthates and
ditertiary phosphanes of the composition Ni(ROCSSb(diphoshhave
been prepared, where R = methyl, ethyl, propyl, butyl, and cyclohexyl
and diphos = bis(diphenylphosphino)ethane (dpe) and bis-
(diphenylphosphino)butane (dpb). The newly prepared compounds
were characterized on the basis of chemical analyses, infrared and
electronic spectra, lH-NMR, molar conductance, and thermal analysis.
A square planar structure was proposed for the complexes
Does ultrasound-guided continuous suprascapular nerve block affect frozen shoulder rehabilitation programme outcome?
Background: Physical therapy (PT) is often recommended for patients with frozen shoulder. However, it could be painful for some patients, and this could hinder the rehabilitation programme. Some procedures like joint injection and suprascapular nerve block (SSNB) could alleviate pain during this setting. Objective: The purpose of this study was to compare the effectiveness of continuous SSNB plus PT compared to PT alone in managing frozen shoulder.Patients and methods: A total of 76 patients with frozen shoulder were included in this study. They were divided into two groups: 38 patients in the injection group (IG) received SSNB via catheter before PT, while the remaining 38 participants in the control group (CG) received no block prior to PT (CG). The functional state of the shoulder joint was assessed via the constant shoulder scale before and just after PT, then one month later.Results: General patient characteristics, including age, gender, BMI, comorbidities, and trauma history, were statistically comparable between the two groups. When we examined the constant scores of the two groups, we found that both had low scores before treatment, which increased immediately after treatment and then increased again one month later. Nonetheless, the injection group had a much greater increase than the control group.Conclusion: When used with PT for the treatment of adhesive capsulitis, continuous SSNB is an effective option that enhances the response to PT. It is associated with better improvement in shoulder function
Nanosized Supramolecular Coordination Polymers Derived from Divalent Metal Ions, 4-Pyridylacetate and Auxiliary Ligands Containing Nitrogen and Phosphorus Donors
A series of coordination polymers of Co(II), Ni(II), Cu(II) or Cd(II) comprising 4-pyridylacetate (pya) and certain auxiliary ligands including benzimidazole (Hbzim), 1,10-phenanthroline (phen), 2,2'-bipyridine (2,2'-bipy), 2-amino-4-methylthiazole (A-Mtz), quinazole (Quz), 2,5-dimethylpyrazine (dpmz), bis(diphenylphosphino)methane (dpm), 1,2-bis(diphenylphosphino)ethane (dpe) and 1,3-bis(diphenylphosphino) propane (dpp) were prepared and characterized by spectroscopic, magnetic and thermal techniques. In these coordination polymers 4-pyridylacetate coordinates to the metal ions in a monodentate fashion through the carboxylate oxygens and/or the pyridyl nitrogen. Octahedral structures around the metal ions were suggested for all the complexes. The kinetic analyses of the thermal decomposition of the complexes were studied using the Coats-Redfern equation. The kinetic and thermodynamic parameters of the thermal decomposition were also calculated and discussed. From the X-ray powder diffraction data, the crystal parameters as well as the particle sizes (15.7-18.7 nm) of the complexes could be evaluated. Some of the compounds exhibit catalytic activity. The biological activity of the compounds was screened as well.
DOI:Â http://dx.doi.org/10.17807/orbital.v13i1.155
Oxidationâreduction potential and sperm DNA fragmentation, and their associations with sperm morphological anomalies amongst fertile and infertile men
Objective: To assess seminal oxidationâreduction potential (ORP) and sperm DNA fragmentation (SDF) in male infertility and their relationships with sperm morphology in fertile and infertile men. Patients and methods: Prospective case-control study comparing the findings of infertile men (n = 1168) to those of men with confirmed fertility (n = 100) regarding demographics and semen characteristics (conventional and advanced semen tests). Spearman rank correlation assessed the correlation between ORP, SDF, and different morphological indices. Means of ORP and SDF were assessed in variable levels of normal sperm morphology amongst all participants. Results: Infertile patients had a significantly lower mean sperm count (32.7 vs 58.7 Ă 10 6 sperm/mL), total motility (50.1% vs 60.4%), and normal morphology (5.7% vs 9.9%). Conversely, infertile patients had significantly higher mean head defects (54% vs 48%), and higher ORP and SDF values than fertile controls. ORP and SDF showed significant positive correlations and significant negative correlations with sperm head defects and normal morphology in infertile patients, respectively. ORP and SDF were significantly inversely associated with the level of normal sperm morphology. Using receiver operating characteristic curve analysis, ORP and SDF threshold values of 1.73 mV/10 6 sperm/mL and 25.5%, respectively, were associated with 76% and 56% sensitivity and 72% and 72.2% specificity, respectively, in differentiating <4% from â„4% normal morphology. Conclusion: A direct inverse relationship exists between seminal ORP and SDF with various levels of normal sperm morphology. Using ORP and SDF measures in conjunction with standard semen morphology analysis could validate the result of the fertility status of patients. © 2017 Arab Association of UrologyScopu
\u3cem\u3e Swietenia mahagoni \u3c/em\u3e Leaves Extract: Antifungal, Insecticidal, and Phytochemical Analysis
In this study, we investigated the antifungal properties of an acetone extract derived from the leaves of Swietenia mahagoni (SMAL) against two isolated fungi, Fusarium equiseti (OQ820153) and Rhizoctonia solani (OQ820152), from rice sheath. The extract was effective in inhibiting the growth of both fungi at the highest concentration tested, 3000 ÎŒg·mLâ1. Laboratory tests on the LC20 of SMAL extract (49.86 mg·Lâ1) versus pyriproxyfen 10% EC (1.96 mg·Lâ1) were accomplished on Aphis gossypii Glover. The extract potently reduced the survival of the nymphs (49.58%) more than the other treatments. The longevity of nymphs treated with the extract had the highest prolongation at 9.67 days. The olfactory choice test exhibited the lowest aphid attraction percentage (23.33%). The HPLC of SMAL extract contained various phenolic compounds, and the most abundant found were catechin (752.64 ”g·gâ1), gallic acid, and chlorogenic acid, as well as flavonoids such as rutin (585.24 ”g·gâ1) and naringenin. A GCâMS analysis revealed n-hexadecanoic acid (37.1%) as the major compound, followed by oleic acid. These results suggest that SMAL extract has the potential to help plants fight against fungal and insect infections, making it a promising natural and renewable solution for long-term plant pest regulation
Nano-refrigerants and nano-lubricants in refrigeration : synthesis, mechanisms, applications, and challenges
Addressing global energy security and environmental concerns, the utilization of nano-refrigerants and nano-lubricants has emerged as an innovative path for enhancing heat transfer. This research focuses on enhancing the thermophysical properties, heat transfer efficiency, and tribological characteristics of nanofluidsânanoparticles dispersed in refrigerants or lubricants. These nanofluids have demonstrated significant potential in applications such as cooling, air conditioning systems, and heat transfer equipment including pumps and pipes. A comprehensive understanding of parameters like thermal conductivity, viscosity, pressure drop, pumping power, and energy performance is delivered, with the aim of enhancing the overall efficiency of refrigeration systems, particularly the coefficient of performance (COP). Additionally, the review covers existing research on flow and pool boiling heat transfer, nano-lubricant tribological enhancement, and nano-refrigerant condensation. The study also addresses the challenges associated with the use of nano-refrigerants and nano-lubricants and offers a prospective outlook for their usage. These novel nanofluids are anticipated to emerge as effective solutions for increasing the COP and reducing energy consumption in the industrial sector, thus extending beyond the scope of previous efforts in this field. This review could serve as a valuable resource for a broad audience interested in this novel approach to energy efficiency
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