185 research outputs found

    Density functional theory study of the electronic and optical properties of pure and magnesium doped Β-tricalcium phosphate compound

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    β-Tri-calcium phosphate material (β-TCP), have attract a wide interest in the material science and medical science applications, due to its excellent biocompatibility and its identical chemical compositions to the natural teeth and bones. For that reason, (β-TCP) compound is widely used as biocompatible ceramics in medical and dental science applications. However, research shows that, pure β-TCP material has lower ability to stimulate the growth of natural bone and teeth as needed. Therefore, in order to address this deficiency magnesium impurity is used to replace calcium in the matrix of pure β-TCP to enhance its electronic and optical properties which are not present in the pure one. Thereby, its biological performance becomes improved. By changing the chemical composition of β-TCP to be similar to the mineral compositions of the natural teeth and bones. This will give more insight in fabrication of biomaterial devices for replacing, repairing and rebuilding the broken or damaged human teeth and bones. Here, we present the study of compound β-TCP using density functional theory (DFT). For the calculations, we used full potential linear augmented plane wave method (FPL-APW), along with generalized gradient approximations (GGA) potential. The band gap values of 5.2 eV and 3.4 eV are obtained for the pure and Mg-doped β-TCP, respectively. These results are in good agreement with the experimental values. Our results show peaks which correspond to the refractive index, complex dielectric function, optical conductivity, optical reflectivity, extinction coefficient, absorption efficient, and electron energy loss. These peaks are shifted towards the higher energy values for the pure and Mg-doped β-TCP material. The obtained results have more significance for increasing the quality of electronic and optical properties of this material and offer more evidences to synthesize enhanced β-TCP material for dental and medical applications

    Analysis of Metal Content of Samples of Gloriosa Superba L (Colchicaceae) Collected from Two Different Locations in Pakistan

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    Purpose: To determine the metallic content of different parts of Gloriosa superba collected from two different locations in Pakistan, and also to assess their nutritious values and toxic levels.Methods: The plant material and soil were collected from two different locations - polluted and unpolluted. Wet digestion method was used for the preparation of samples (whole plant and soil) followed by analysis using flame atomic absorption spectrophotometer (for micronutrients) and flame photometry (for macronutrients).Results: Of the detected micronutrients, high concentrations of Zn, Fe and Mn were noted for samples collected from both areas. These values were within permissible limits. Samples collected from the polluted area contained Cu (7.5 – 13.0 ppm), Cr (1.4 − 1.9 ppm) and Ni (0.3 − 2.0 ppm), all of which exceeded acceptable limits; the same nutrients were mostly within acceptable limits for samples collected from the unpolluted area. Significant presence of macronutrients - Ca, Na and K - were observed in samples obtained from both areas.Conclusion: Proper validation of medicinal plants used for therapeutic purposes should be mandatory on safety grounds to protect consumers from contaminants.Keywords: Gloriosa superba, Micronutrients, Macronutrients, Toxicity, Metal ions, Medicinal plant

    Unconventional method for monitoring of waste cooking oil transesterification

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    A technique to monitor transesterification of waste cooking oil (WCO) is presented. The technique was developed based on analogue signal from WCO, fatty acid methyl ester (FAME) and commercial palm oil (CPO). A low-pass filter design for the photodiode was used to obtain the characteristic analog signal generated by these oil samples and the signal was correlated to absorbance spectra of the oils using data from Fourier transform infrared (FTIR) equipment. A match was made between the analogue signals of the oil samples and calibrated against the FTIR spectra at 95% confidence level. Depletion of WCO during transesterification in a batch reactor correlated with the time observed for peak yield during biodiesel production. The results of the technique are discussed as a possible way to monitor transesterification process in a batch reactor

    Studies on Polybenzimidazole and Methanesulfonate Protic-Ionic-Liquids-Based Composite Polymer Electrolyte Membranes

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    Funding Information: This project was funded by the National Plan for Science, Technology and Innovation (MAARIFAH), King Abdulaziz City for Science and Technology, Kingdom of Saudi Arabia, Award Number (2-17-01-001-0042). Publisher Copyright: © 2023 by the authors.In the present work, different methanesulfonate-based protic ionic liquids (PILs) were synthesized and their structural characterization was performed using FTIR, 1H, and 13C NMR spectroscopy. Their thermal behavior and stability were studied using DSC and TGA, respectively, and EIS was used to study the ionic conductivity of these PILs. The PIL, which was diethanolammonium-methanesulfonate-based due to its compatibility with polybenzimidazole (PBI) to form composite membranes, was used to prepare proton-conducting polymer electrolyte membranes (PEMs) for prospective high-temperature fuel cell application. The prepared PEMs were further characterized using FTIR, DSC, TGA, SEM, and EIS. The FTIR results indicated good interaction among the PEM components and the DSC results suggested good miscibility and a plasticizing effect of the incorporated PIL in the PBI polymer matrix. All the PEMs showed good thermal stability and good proton conductivity for prospective high-temperature fuel cell application.publishersversionpublishe

    The Chemical Composition and Health-Promoting Effects of the Grewia Species—A Systematic Review and Meta-Analysis

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    Globally grown and organoleptically appreciated Grewia species are known as sources of bioactive compounds that avert the risk of communicable and non-communicable diseases. Therefore, in recent years, the genus Grewia has attracted increasing scientific attention. This is the first systematic review which focusses primarily on the nutritional composition, phytochemical profile, pharmacological properties, and disease preventative role of Grewia species. The literature published from 1975 to 2021 was searched to retrieve relevant articles from databases such as Google Scholar, Scopus, PubMed, and Web of Science. Two independent reviewers carried out the screening, selection of articles, and data extraction. Of 815 references, 56 met our inclusion criteria. G. asiatica and G. optiva were the most frequently studied species. We found 167 chemical compounds from 12 Grewia species, allocated to 21 categories. Flavonoids represented 41.31% of the reported bioactive compounds, followed by protein and amino acids (10.7%), fats and fatty acids (9.58%), ash and minerals (6.58%), and non-flavonoid polyphenols (5.96%). Crude extracts, enriched with bioactive compounds, and isolated compounds from the Grewia species show antioxidant, anticancer, anti-inflammatory, antidiabetic, hepatoprotective/radioprotective, immunomodulatory, and sedative hypnotic potential. Moreover, antimicrobial properties, improvement in learning and memory deficits, and effectiveness against neurodegenerative ailments are also described within the reviewed article. Nowadays, the side effects of some synthetic drugs and therapies, and bottlenecks in the drug development pathway have directed the attention of researchers and pharmaceutical industries towards the development of new products that are safe, cost-effective, and readily available. However, the application of the Grewia species in pharmaceutical industries is still limited

    Systematic Review in Patients with Benign Prostatic Hyperplasia for The Role of Prostatic Arterial Embolization

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    This study aimed at reviewing the role of Prostatic Arterial Embolization (PAE) as a new treatment producer for patients with Benign Prostatic Hyperplasia (BPH). The study reviewed the recent researches of  Prostatic Arterial Embolization (PAE) as a new treatment technique and concluded that the initial reported results of PAE seem promising, mainly during the first 12 months after treatment. However, no comparison was made to medical therapy or surgical therapies. Overlapping patient data and reporting bias could not be excluded. None of the included studies performed a power analysis. Also, a relatively small number of patients are treated with a short follow-up period. Therefore, more studies are needed with more patients and longer periods of follow-up, compared with standard medical and surgical therapies, to assess whether PAE is an effective and safe alternative treatment for BPH

    Comparison of the efficacy of lotrafilcon B and comfilcon A silicone hydrogel bandage contact lenses after transepithelial photorefractive keratectomy

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    Background: At completion of transepithelial photorefractive keratectomy (t-PRK) surgery, the eye is usually fitted with a bandage contact lens to reduce discomfort and promote epithelial healing. This study aimed to compare the outcomes of eyes fitted with lotrafilcon B versus comfilcon A, silicone hydrogel bandage contact lenses after t-PRK for the correction of low to moderate myopia, with or without astigmatism. Methods: In this comparative, prospective study, patients with myopia < -6 D with or without astigmatism (< 1.75 D), who underwent t-PRK between January and June 2018, were randomly allocated to the lotrafilcon B and comfilcon A groups. Preoperative characteristics, including age, sex, eye treated, uncorrected visual acuity (UCVA), best-corrected visual acuity, mesopic pupil size, central corneal thickness, and refractive error were recorded. Postoperatively, pain score, UCVA, and corneal epithelial defect size on days 1, 4, and 7 were compared between the two groups. Results: Twenty-nine eyes were included in each group. Demographic characteristics and preoperative measurements were similar between the two groups. UCVA was significantly improved on day 7 as compared to day 1 in the comfilcon A group (P = 0.03), but remained the same in the lotrafilcon B group (P = 0.70) as on day 1 postoperatively. There was no significant difference in UCVA between the two groups at any follow-up visits (all P > 0.05). The pain score on the first postoperative day was significantly higher in the lotrafilcon B-fitted eyes than in the comfilcon A group (P < 0.001), but was significantly reduced in both groups compared to day 1 (both P < 0.001). The epithelial defect in the comfilcon A group was significantly greater than in the lotrafilcon B group (P < 0.001) at day 1 postoperatively, with significant improvement in both groups (both P < 0.001). Conclusions: Healing responses were better with lotrafilcon B than with comfilcon A bandage contact lenses. The patients had a greater mean pain score with lotrafilcon B than with comfilcon A lenses on the first postoperative day, yet the final outcome was comparable between the two groups. We did not encounter any postoperative complications related to contact lens wear

    Terbufos sulfon pogoršava srčane lezije u štakora koji boluju od dijabetesa: studija subakutne toksičnosti

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    Organophosphorus compounds (OPCs) have a wide range of applications, from agriculture to warfare. Exposure to these brings forward a varied kind of health issues globally. Terbufos is one of the leading OPCs used worldwide. The present study investigates the cardiac effect of no observable dose of a metabolite of terbufos, terbufos-sulfone (TS), under nondiabetic and streptozotocin-induced diabetic condition. 100 nmol per rat (1/20 of LD50) was administered intraperitoneally to adult male Wister rats daily for fifteen days. The left ventricle was collected for ultrastructural changes by transmission electron microscopy. The blood samples were collected for biochemical tests including RBC acetylcholinesterase, creatinine kinase (CK), lactate dehydrogenase (LDH), cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), triglycerides, ALT, AST, and GGT. The study revealed about 10 % inhibition of RBC-AChE in two weeks of TS treatment in non-diabetic rats whereas RBC-AChE activity was significantly decreased in diabetic TS treated rats. CK, LDH, and triglycerides were significantly higher in diabetic TS treated rats. Electron microscopy of the heart showed derangement and lesions of the mitochondria of cardiomyocytes in the TS treated groups. The present study concludes that a non-lethal dose of TS causes cardiac lesions which exacerbate under diabetic condition. Biochemical tests confirmed the ultrastructural changes. It is concluded that a non-lethal dose of TS may be a risk factor for a cardiovascular disease, which may be fatal under diabetic condition.Organofosforni spojevi (eng. Organophosphorous Compounds - OPCs) imaju široku primjenu, od one u poljoprivredi do one u vojne svrhe. Izlaganje takvim spojevima izaziva niz različitih zdravstvenih problema od globalnog značaja. Terbufos je jedan od vodećih OPC-a koji se koriste diljem svijeta. U ovom je istraživanju na modelu štakora bez dijabetesa sa streptozotocinom izazvanim dijabetesom ispitivan metabolit terbufos-sulfon (TS) u najvišoj dozi koja ne izaziva učinak te njezin utjecaj na srce. Odrasli mužjaci štakora soja Wistar dobivali su petnaest dana dnevnu dozu od 100 nmol štakor-1 (1/20 LD50) intraperitonealno. Transmisijskim elektronskim mikroskopom istražene su ultrastrukturne promjene lijeve klijetke. Na krvnim uzorcima provedeni su biokemijski testovi, uključujući aktivnost acetilkolinesteraze u crvenim krvnim stanicama, razinu kreatinin kinaze (CK), laktat dehidrogenaze (LDH), kolesterola, lipoproteina visoke gustoće (HDL), lipoproteina niske gustoće (LDL), triglicerida, ALT, AST i GGT. Istraživanjem je otkriveno oko 10 % inhibicije AChE-a u crvenim krvnim stanicama nakon dva tjedna izlaganja štakora bez dijabetesa TS-u, dok je u štakora s dijabetesom aktivnost AChE-a bila značajno smanjena. Razine CK, LDH i triglicerida bile su značajno više u TS tretiranim štakorima s dijabetesom. Elektronsko-mikroskopska analiza srca upućuje na narušenu strukturu i lezije u mitohondrijima u kardiomiocitima skupina štakora koji su tretirani TS-om. Zaključuje se da nesmrtonosna doza TS-a uzrokuje srčane lezije koje se pogoršavaju u prisutnosti dijabetesa. Biokemijski testovi potvrdili su ultrastrukturne promjene. Navedena doza TS-a može biti rizični čimbenik za kardiovaskularne bolesti, koje se mogu pokazati smrtonosnima uz istovremeno postojanje dijabetesa

    Development of gliclazide matrix tablets from pure and blended mixture of glyceryl monostearate and stearic acid

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    The present study was undertaken to evaluate the effect of glyceryl monostearate (GMS) and stearic acid (SA) on the release profile of gliclazide from the matrix. Matrix tablets for the controlled delivery of gliclazide were prepared by hot melt method using pure and blended mixture of glyceryl monostearate and stearic acid in different drug to polymer and polymer to polymer ratios. In vitro release characteristics of gliclazide from these hydrophobic matrices were studied over 8 h in phosphate buffer media of pH 7.4. The release kinetics of drug was evaluated for zero order, first order, Higuchi and Peppas kinetic models. It was observed that the release of drug from the matrix was greatly retarded by GMS and retarding effect increased with increasing polymer to drug ratios. On the other hand SA appeared to channel the drug from the wax matrix and release was greatly increased with increasing polymer to drug ratios. The kinetic evaluation of release profile indicated that the Higuchi model was the most appropriate model for describing the release profile of gliclazide. The application of Peppas biexponential equation indicated that non-Fickian release was the predominant mechanism of drug release. The FTIR results showed no interaction between the drug and the polymers and DSC results indicated that both the drug and polymers are in amorphous state and no significant complexes were formed. The results indicated that proper selection of drug to polymer and polymer to polymer ratios were important in order to achieve the desired dissolution profile in these matrix tablets.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Re-structuring university hospital’s internship program using kern’s six-step model of Instructional design

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    Abstract Background: Internship is a phase of training wherein a graduate learns in the context of practice, acquiring skills under supervision so that he/she may become capable of functioning independently. We are reporting the process of curriculum restructuring for strengthening the Internship Program at this university hospital. Methodology: We used Kerns’ six-step model to evaluate and restructure the internship curriculum. Step 01: Problem Identification & General need assessment- Thorough literature review revealed Internship as the crucial year of training that needs to be fashioned around the competencies required to make good doctor
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