96 research outputs found

    The fabrication of potentiometric membrane sensors and their applications

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    Ionophore-incorporated PVC-membrane sensors are well-established analytical tools routinely used for the selective and direct measurement of a wide variety of different ions in complex biological and environmental samples. The key ingredient of such plasticized PVC-members is the involved ionophore, defining the selectivity of the electrodes complex formation with the cation of interest. In the past few years, the development of new ion-selective electrodes for various ions has been reported inthe literature

    Poly(lactic-co-glycolic) acid drug delivery systems through transdermal pathway : an overview

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    In past few decades, scientists have made tremendous advancement in the field of drug delivery systems (DDS), through transdermal pathway, as the skin represents a ready and large surface area for delivering drugs. Efforts are in progress to design efficient transdermal DDS that support sustained drug release at the targeted area for longer duration in the recommended therapeutic window without producing side-effects. Poly(lactic-co-glycolic acid) (PLGA) is one of the most promising Food and Drug Administration approved synthetic polymers in designing versatile drug delivery carriers for different drug administration routes, including transdermal drug delivery. The present review provides a brief introduction over the transdermal drug delivery and PLGA as a material in context to its role in designing drug delivery vehicles. Attempts are made to compile literatures over PLGA-based drug delivery vehicles, including microneedles, nanoparticles, and nanofibers and their role in transdermal drug delivery of different therapeutic agents. Different nanostructure evaluation techniques with their working principles are briefly explained.RL thanks the funding support from Singapore National Research Foundation under its Translational and Clinical Research Flagship Programme (NMRC/TCR/008-SERI/2013) and administered by the Singapore Ministry of Health’s National Medical Research Council and Co-operative Basic Research Grant from the Singapore National Medical Research Council (Project No. NMRC/CBRG/0048/2013).info:eu-repo/semantics/publishedVersio

    Materials for Pharmaceutical Dosage Forms: Molecular Pharmaceutics and Controlled Release Drug Delivery Aspects

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    Controlled release delivery is available for many routes of administration and offers many advantages (as microparticles and nanoparticles) over immediate release delivery. These advantages include reduced dosing frequency, better therapeutic control, fewer side effects, and, consequently, these dosage forms are well accepted by patients. Advances in polymer material science, particle engineering design, manufacture, and nanotechnology have led the way to the introduction of several marketed controlled release products and several more are in pre-clinical and clinical development

    Effects of a buried magnetic field on cranial bone reconstruction in rats

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    ABSTRACT The understanding of bone repair phenomena is a fundamental part of dentistry and maxillofacial surgery. Objective The present study aimed to evaluate the influence of buried magnetic field stimulation on bone repair in rat calvaria after reconstruction with autogenous bone grafts, synthetic powdered hydroxyapatite, or allogeneic cartilage grafts, with or without exposure to magnetic stimulation. Material and Methods Ninety male Wistar rats were divided into 18 groups of five animals each. Critical bone defects were created in the rats’ calvaria and immediately reconstructed with autogenous bone, powdered synthetic hydroxyapatite or allogeneic cartilage. Magnetic implants were also placed in half the animals. Rats were euthanized for analysis at 15, 30, and 60 postoperative days. Histomorphometric analyses of the quantity of bone repair were performed at all times. Results These analyses showed significant group by postoperative time interactions (p=0.008). Among the rats subjected to autogenous bone reconstruction, those exposed to magnetic stimulation had higher bone fill percentages than those without magnetic implants. Results also showed that the quality of bone repair remained higher in the former group as compared to the latter at 60 postoperative days. Conclusions After 60 postoperative days, bone repair was greater in the group treated with autogenous bone grafts and exposed to a magnetic field, and bone repair was most pronounced in animals treated with autogenous bone grafts, followed by those treated with powdered synthetic hydroxyapatite and allogeneic cartilage grafts

    Review of the potential use of bacterial Precipitation in self-healing, improving durability and properties of concrete

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    Concrete is one of the most widely used constructional materials which is disposed to cracking for various reasons. Cracking is one of the unavoidable defects in concrete. When micro-cracks develop and join together, a continuous network of cracks is formed inside the concrete. Cracks increase the permeability and reduce the impermeability against moisture and aggressive substances such as sulfate ions, chloride ions, and acids. These factors affect the structure durability and reinforcement corrosion and destroy the concrete matrix. The concrete self-healing approaches appear to be an appropriate idea to remove this damage. Among the different self-healing ways which are basically chemical, the Calcium Carbonate precipitation, resulting from the micro-organisms metabolic activities, is a new environmentally friendly strategy. Their ecological variety is high and can be found in different natural settings. In this way, to treat damaged structures, a microbial process is applied wherein the combination of bacteria, urea, and a calcium source forms calcium carbonate crystal that results in crack reduction, impermeability, and improved concrete mechanical properties. Biologically, the calcium carbonate precipitation helps heal the small cracks, fill pores, and bind other materials such as sand and gravel in concrete. These precipitations are the byproducts of the usual metabolic processes such as photosynthesis, urea hydrolysis, and sulfate reduction. To obtain a useful insight in this important researching area and to protect the environment, this article investigates different approaches of using bacteria in concrete, the bacteria potential to heal the cracks. Improving the properties of concrete was examined, and the laboratory results were interpreted. Investigation of the concrete micro-structure indicated the formation of the calcite crystals in the samples and confirmed the promising performance of bacteria in healing micro-cracks, improving the mechanical properties, and the concrete durability in the destructive environments. By reducing structural pores, bacterial participation at a concentration of 105-107 cells/ml led to an increase in compressive strength by and a decrease in the penetration of chloride ions and water absorption to and , respectively. Moreover, the maximum crack healing width at a concentration of 107-109 cells/ml about was mm

    Ion recognition: application of symmetric and asymmetric schiff bases and their complexes for the fabrication of cationic and anionic membrane sensors to determine ions in real samples

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    Schiff base compounds refer to the branch of supra-molecules and can be used as sensing material in the construction of potentiometric ion selective electrodes (ISEs). This relatively modern field has been subject to extensive research in the period of 1999-2007 when more than 100 ISEs employing Schiff bases were constructed. The quantitative high-throughput detection of 29 cations and 7 anions has been demonstrated in various scientific branches, such as biomedicine, pharmacy, biochemistry, pharmacology, environmental chemistry, food technology, and agriculture. This review discusses Schiff base compounds and their applications in the design and development of ion selective sensors and microsensors

    Computational analysis of bio-convective eyring-powell nanofluid flow with magneto-hydrodynamic effects over an isothermal cone surface with convective boundary condition

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    Non-Newtonian fluids are essential in situations where heat and mass transfer are involved. Heat and mass transfer processes increase efficiency when nanoparticles (0.01≤φ≤0.03) are added to these fluids. The present study implements a computational approach to investigate the behavior of non-Newtonian nanofluids on the surface of an upright cone. Viscous dissipation (0.3≤Ec≤0.9) and magnetohydrodynamics (MHD) (1≤M≤3) are also taken into account. Furthermore, we explore how microorganisms impact the fluid's mass and heat transfer. The physical model's governing equations are transformed into ordinary differential equations (ODEs) using a similarity transformation to make the analysis easier. The ODEs are solved numerically using the Bvp4c solver in MATLAB. The momentum, thermal, concentration, and microbe diffusion profiles are graphically represented in the current research. MHD (1≤M≤3) effects improve the diffusion of microbes, resulting in increased heat and mass transfer rates of 18 % and 19 %, respectively, based on our results. Furthermore, a comparison of our findings with existing literature demonstrates promising agreement

    Stimuli-Responsive Polymers

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