292 research outputs found
Comparison between polyvinyl alcohol (PVA) nanofiber and polyvinyl alcohol (PVA) nanofiber/hydroxyapatite (HA) for removal of Zn2+ ions from wastewater
AbstractNanocomposites in the form of continuous and aligned polyvinyl alcohol (PVA) nanofibers have been obtained by the electrospinning process. These fibers were used as matrix for hydroxyapatite (HA). PVA and PVA/HA nanofibers were fabricated and crosslinked with glutaraldehyde (GA). The hybrid of polymer with ceramics (HA) shows good properties of large surface area and good porosity that were demonstrated by different characterization techniques such as FTIR, SEM, XRD and EDX which illustrate the ratio of HA. The prepared nanofibrous membranes are used for removal of Zn2+ from simulated water. The potential of these synthesized sorbents to remove Zn2+ ions from aqueous solutions was investigated in batch experiments, where several parameters such as the sorbate/sorbent’s contact time, initial Zn2+ ions concentration and sorbent dosage were investigated. The equilibrium concentration of Zn2+ ions was identified by the atomic absorption spectrophotometry and the adsorption process was studied by the isotherm models such as Langmuir, Freundlich and Temkin. The Zn2+ adsorption process for PVA and PVA/HA nanofibrous membranes was fitted to Langmuir and Freundlich isotherm models respectively
ENHANCEMENT OF DISSOLUTION RATE OF HYDROCHLOROTHIAZIDE
Objective: The aim of this study was to enhance the dissolution rate of hydrochlorothiazide (HCTZ).Methods: Binary solid dispersions (SDs) of HCTZ with increasing weight ratios of poloxamer 407, polyethylene glycol 6000 (PEG 6000) or gelucire 50/13 were prepared by solvent evaporation technique. The solid dispersions were deposited on the surface of aerosil 200 to produce a dry product with large surface area. The SDs were characterized with respect to drug dissolution. The mechanism of dissolution enhancement was researched using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC).Results: The unprocessed drug showed erratic, slow dissolution which can be explained on the basis of its hydrophobic nature. Preparation of SDs with hydrophilic carriers resulted in a significant increase in the dissolution rate with most of the drug being liberated in the first 5 min. The dissolution pattern of the drug from the prepared SDs depends mainly on the type of polymer used, and the best dissolution pattern was observed in the SD prepared using 1:1 ratio of the drug to gelucire 50/13 in the presence of aerosil 200 as a carrier. FTIR studies revealed no interaction between the drug and polymers. DSC showed a change in the crystalline structure of the drug after SDs formation. This change can explain the recorded dissolution enhancement.Conclusion: The study presented a system capable of increasing the dissolution rate of HCTZ using polymers which can increase the intestinal permeability as well.Keywords: Hydrochlorothiazide, Poloxamer 407, PEG 6000, Gelucire 50/13, Solid dispersion, Dissolutio
Penetration enhancers in proniosomes as a new strategy for enhanced transdermal drug delivery
AbstractThe aim of this work is to investigate penetration enhancers in proniosomes as a transdermal delivery system for nisoldipine. This was performed with the goal of optimising the composition of proniosomes as transdermal drug delivery systems. Plain proniosomes comprising sorbitan monostearate, cholesterol, ethanol and a small quantity of water were initially prepared. Subsequently, proniosomes containing lecithin or skin penetration enhancers were prepared and evaluated for transdermal delivery of nisoldipine. The plain proniosomes significantly enhanced the transdermal flux of nisoldipine to reach 12.18μgcm−2h−1 compared with a saturated aqueous drug solution which delivered the drug at a rate of 0.46μgcm−2h−1. Incorporation of lecithin into such proniosomes increased the drug flux to reach a value of 28.51μgcm−2h−1. This increase can be attributed to the penetration enhancing effect of lecithin fatty acid components. Replacing lecithin oleic acid (OA) produced proniosomes of comparable efficacy to the lecithin containing system. The transdermal drug flux increased further after incorporation of propylene glycol into the OA based proniosomes. Similarly, incorporation of isopropyl myristate into plain proniosomes increased drug flux. The study introduced enhanced proniosomes as a promising transdermal delivery carrier and highlighted the role of penetration enhancing mechanisms in enhanced proniosomal skin delivery. The study opened the way for another line of optimisation of niosome proconcentrates
Enhancing Authentication in Online Distant Exams: A Proposed Method Utilizing Face and Voice Recognition
Due to COVID-19 pandemic, face-to-face teaching has been replaced by online education to reduce the risks of spreading the Coronavirus. Online examination is an important asset in the context of online learning to assess students, but observing students during testing and ensuring that they do not engage in misbehavior remains a major issue. Human observation is one of the most common methods when conducting an exam to ensure that students do not perform any unexpected behaviors, by entering the student in a laboratory or hall at the university and observing him throughout the exam period visually and soundly. However, this method is costly and labor-intensive. In this paper, a system is created that monitors students during an online test automatically based on face recognition and voice recognition using a machine learning algorithm. The camera on the students computer will be used to track the students facial movements, pupils, and lip movements, monitoring the students behavior throughout the test, and stopping any unexpected behavior. In this system, there are two parts: facial recognition and unexpected behavior detection. The face was recognized with an accuracy of 98.3%, and unexpected behavior was detected with an accuracy of 97.6%. There is also an opportunity to increase accuracy by improving the quality of the images in the dataset
INTESTINAL ABSORPTION OF EPROSARTAN MESYLATE FROM SELF EMULSIFYING SYSTEM AND CYCLODEXTRIN COMPLEX
Objective: The aim of this work was to determine the intestinal membrane transport parameters of eprosartan mesylate (EM) and to investigate self-nano emulsifying drug delivery systems (SNEDDS) and inclusion complexation with hydroxypropyl b cyclodextrin (HPbCD) for enhanced intestinal absorption of eprosartan mesylate. Methods: The intestinal absorption was monitored using the in situ rabbit intestinal perfusion technique. SNEDDS was developed using labrafil, Lauroglycol with a tween in the presence of ethanol. Inclusion complexation was achieved by construction of phase solubility diagram in the presence of HPbCD. The prepared complex was evaluated using Fourier Transform Infrared Spectroscopy (FTIR) and differential scanning calorimetry (DSC). Results: The drug was found to be poorly absorbed from the jejuno-ileum and the colon with the absorption being mainly through paracellular pathway. An inclusion complex was developed between the drug and HPβCD. Perfusion of the drug in the nanoemulsion formulation or as an inclusion complex resulted in a significant increase in the intestinal absorption of the drug compared with the control.Conclusion: SNEDDS and inclusion complexation are promising strategies for enhanced intestinal absorption of eprosartan mesylate
Extensive Characterization of Raw Barley Straw and Study the Effect of Steam Pretreatment
Abstract: The properties of barely straw play a crucial role in some industrial applications. Despite that, there is a lack of its scientific data concerning thermal, mechanical and chemical properties of these fibers. To maximize their potential use it is necessary to understand their characteristic. In this work, barely straw was characterized by analytical techniques such as FTIR, X-ray, TGA and SEM. The straw treated with distilled water and compare the new analytical properties with the properties of the raw, which revealed that the adsorption properties improved with steam treatment due to increase of functional groups which can share in adsorption reaction
1,3-Dimethylbenzo[b]dibenzothiophene
The molecule of the title compound, C18H14S, is approximately planar (r.m.s. deviation = 0.029 Å). The crystal packing is stabilized by weak intermolecular C—H⋯π interactions
(Z)-3-(4-Fluorophenyl)-1-[4-(methylsulfonyl)phenyl]-2-tosylprop-2-en-1-one
In the title compound, C23H19FO5S2, two of the phenyl ring C atoms and a sulfonyl O atom of the phenyl(methylsulfonyl) group are disordered over two positions with occupancies 0.522 (17):0.478 (17). The methylphenyl and fluorophenyl rings are essentially planar, with maximum deviations of 0.0059 (8) and 0.0047 (9) Å, respectively. The crystal packing is stabilized by C—H⋯F interactions
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Treatment of Sweet Pepper with Stress Tolerance-Inducing Compounds Alleviates Salinity Stress Oxidative Damage by Mediating the Physio-Biochemical Activities and Antioxidant Systems
Salinity stress occurs due to the accumulation of high levels of salts in soil, which ultimately leads to the impairment of plant growth and crop loss. Stress tolerance-inducing compounds have a remarkable ability to improve growth and minimize the effects of salinity stress without negatively affecting the environment by controlling the physiological and molecular activities in plants. Two pot experiments were carried out in 2017 and 2018 to study the influence of salicylic acid (1 mM), yeast extract (6 g L−1), and proline (10 mM) on the physiological and biochemical parameters of sweet pepper plants under saline conditions (2000 and 4000 ppm). The results showed that salt stress led to decreasing the chlorophyll content, relative water content, and fruit yields, whereas electrolyte leakage, malondialdehyde (MDA), proline concentration, reactive oxygen species (ROS), and the activities of antioxidant enzymes increased in salt-stressed plants. The application of salicylic acid (1 mM), yeast extract (6 g L−1), and proline (10 mM) markedly improved the physiological characteristics and fruit yields of salt-stressed plants compared with untreated stressed plants. A significant reduction in electrolyte leakage, MDA, and ROS was also recorded for all treatments. In conclusion, our results reveal the important role of proline, SA, and yeast extracts in enhancing sweet pepper growth and tolerance to salinity stress via modulation of the physiological parameters and antioxidants machinery. Interestingly, proline proved to be the best treatment.</jats:p
Effect of different forms of silica on the physical and mechanical properties of gypsum plaster composites
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