105 research outputs found

    Preparation and spectroscopic studies of Hydroxyapatite embedded in Poly(N-Vinylpyrrolidone) matrix

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    Pure HAp powder was prepared by precipitation and HAp/PVP composites were prepared by casting technique. X-ray diffraction was performed to examine the crystallinity and the complexation between HAp and PVP when the amount of HAp increased. XRD and EDX analysis showed that the concentration 15 wt% is the most confirmation for the formation of HAp. SEM shows more than one form of HAp such as plates, needles and bundles in the morphological structure of pure HAp and 15 wt% of HAp. Two main weight loss regions and two peaks were observed in TGA and DSC thermograms that reveal reduction in the thermal stability of the prepared samples as HAp content increases. The activation energy of the films was decreased with increasing the concentration of HAp. DSC thermographs of the samples show that the values of the glass transition temperatures are decreased with increasing the content of HAp filler which suggest that HAp filler act as plasticizer. The conductivity–temperature plots show linear variation, which suggests an Arrhenius behavior. The conductivity increases with adding HAp content for low concentrations while decreased for the critical concentration (15 wt %) which confirms the XRD results

    Synthesis, characterization, and antimicrobial properties of novel double layer nanocomposite electrospun fibers for wound dressing applications

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    Herein, novel hybrid nanomaterials were developed for wound dressing applications with antimicrobial properties. Electrospinning was used to fabricate a double layer nanocomposite nanofibrous mat consisting of an upper layer of poly(vinyl alcohol) and chitosan loaded with silver nanoparticles (AgNPs) and a lower layer of polyethylene oxide (PEO) or polyvinylpyr- rolidone (PVP) nanofibers loaded with chlorhexidine (as an antiseptic). The top layer containing AgNPs, whose purpose was to protect the wound site against environmental germ invasion, was prepared by reducing silver nitrate to its nanoparticulate form through interaction with chitosan. The lower layer, which would be in direct contact with the injured site, contained the antibi- otic drug needed to avoid wound infections which would otherwise interfere with the healing process. Initially, the upper layer was electrospun, followed sequentially by electrospinning the second layer, creating a bilayer nanofibrous mat. The morphology of the nanofibrous mats was studied by scanning electron microscopy and transmission electron microscopy, showing successful nanofiber production. X-ray diffraction confirmed the reduction of silver nitrate to AgNPs. Fourier transform infrared spectroscopy showed a successful incorporation of the material used in the produced nanofibrous mats. Thermal studies carried out by thermogravi- metric analysis indicated that the PVP–drug-loaded layer had the highest thermal stability in comparison to other fabricated nanofibrous mats. Antimicrobial activities of the as-synthesized nanofibrous mats against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans were determined using disk diffusion method. The results indicated that the PEO–drug-loaded mat had the highest antibacterial activity, warranting further attention for numerous wound-healing applications.QUST-CAS-SPR-14\15-

    Effect of Physical Exercise on Bone Density and Remodeling in Egyptian Type 1 Diabetic Osteopenic Adolescents

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    <p>Abstract</p> <p>Background</p> <p>The study was planned to assess effect of physical exercise on bone remodeling in type I diabetics with osteopenia.</p> <p>Methods</p> <p>Twenty-four type I diabetes mellitus (DM1) with osteopenia (10 females and 14 males) were compared to thirty-eight age- and sex-matched healthy control individuals (20 females and 18 males) for biochemical and radiologic parameters of bone mass. Laboratory investigations included serum and urinary calcium, inorganic phosphorus, alkaline phosphatase, and serum "procollagen type 1 N-terminal propeptide (P1NP). Bone densitometry was assessed at neck femur using Dual Energy X-ray Absorptiometry (DEXA). Serum P1NP and DEXA were reevaluated after a planned exercise program.</p> <p>Results</p> <p>Patients and controls were comparable with respect to serum as well as urinary biochemical parameters of bone mass namely; calcium, phosphorus and total serum alkaline phosphatase. Osteopenic DM1 patients displayed lower mean serum P1NP than control group (20.11 ± 6.72 ugdL versus 64.96 ± 34.89 ugdL; p < 0.05). A significant correlation was observed between BMD and degree of glycemic control reflected by serum glycated hemoglobin (r = -0.44, p, 0.030). Bone densitometry correlated with serum P1NP (r = -0.508, p, 0.011). After a planned regular exercise for 3 months, serum P1NP and BMD levels increased with percentage change of 40.88 ± 31.73 and 3.36 ± 2.94, respectively. Five patients resumed normal densitometry and they were all males.</p> <p>Conclusion</p> <p>Diabetic osteopenic patients displayed lower serum levels of procollagen type 1 N-terminal propeptide which reflects poor bone formation. A 3-months planned exercise program was associated with improvement of bone densitometry and significant increment of serum P1NP.</p

    Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

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    Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p&lt;0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p&lt;0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

    Physical properties of MnCl2 fillers incorporated into a PVDF/PVC blend and their complexes

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    Films of a PVDF/PVC blend filled with different concentrations of MnCl2 were prepared by using a casting technique. The prepared films were investigated by different methods. X-ray diffraction scans revealed the amorphous nature of the blend for low concentrations and a crystalline nature for higher ones. Results obtained by FTIR led to conclusions about the specific interactions in the polymer matrices and hence about the complexation. The morphological structure of the prepared samples was studied by SEM, which confirmed the results of XRD and DC electrical conductivity measurements. The ESR spectra of the samples exhibited resonance signals only after the introduction of Mn2þ ions into the blend. The DC conductivity was measured in the temperature range of 300–435 K in order to analyze the mechanism of the conduction. The conductivity–temperature plots were found to follow an Arrhenius relationship
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