1,850 research outputs found

    FORMULATION, OPTIMIZATION, AND CHARACTERIZATION OF BIOCOMPATIBLE INHALABLE D-CYCLOSERINE-LOADED ALGINATE-CHITOSAN NANOPARTICLES FOR PULMONARY DRUG DELIVERY

    Get PDF
    ABSTRACTObjective: To prepare Nanoparticulate dosage form having improved drug bioavailability and reduced dosing frequency of antitubercular drugswhich will helps in improving patient compliance in the treatment of multi-drug resistant tuberculosis (MDR-TB).Methods: Ionotropic gelation method was used to prepare D-cycloserine (D-CS)-loaded alginate-chitosan nanoparticles, and the particles arecharacterized by their particle size and morphology using particle size analyzer and scanning electron microscopy (SEM). X-ray diffraction (XRD),differential scanning calorimetry (DSC), and Fourier-transformed infrared (FTIR) studies were used to determine drug-polymer interactions and drugentrapment. Entrapment efficiency, drug loading (DL), particle size, and zeta potential of nanoparticles were also studied. The 2 factorial designs ofexperiments by Design-Expert® V9 were used to optimize the particle size and entrapment efficiency of nanoparticles.Results: The optimized batch had shown the entrapment efficiency of 98.10±0.24% and DL of 69.32±0.44% with particle size and zeta potentialas 344±5 nm and −42±11.40 mV, respectively. DSC, FTIR, and XRD studies confirmed the drug entrapment within nanoparticle matrix. SEM resultsshowed spherical-shaped particles. Sustained release of drug from the nanoparticles was observed for 24 hrs period. Respirable fraction up to52.37±0.7% demonstrates the formulation suitability for deep lung delivery. Lung inflammatory study showed a less inflammatory response.Conclusion: Ionotropic gelation method can be used to prepare biocompatible particles with a high entrapment efficiency, DL, optimum particle size,and controlled release characteristics, which can serve as a convenient delivery system for D-CS and could be a potential alternative to the existingconventional therapy in MDR-TB.Keywords: Nanoparticles, Alginate, Chitosan, Inhalation, Sustained release, Tuberculosis.

    Polyphasic identification of amylolytic bacteria producing bioplastic Poly-β-hydroxybutyrate (PHB)

    Get PDF
    The final goal of this study is to make a modern systematic-based inventory of amylolytic bacterial isolates producing of bioplastic Poly-β-hydroxybutyrate (PHB) from sago starch substrate. The identity of three local bacterial isolates was examined in this study, using a polyphasic approach. A data set based on phenotypic characteristics, namely morphological, physiological, biochemical and chemical character, namely whole cells protein profiles using SDS-PAGE method, together with phylogenetic studies based on 16S rRNA sequences was used to identified by polyphasic approach. Phenotypic characteristics of 3 local bacterial isolates and 4 reference strains to members of genus Bacillus was analyzed by numerical analysis using MVSP 3,1 program to determine the value of similarity. Based on the preliminary characterization of the profile matching method showed that the three isolates of bacteria producing PHB namely PSA10, PPK5 and PPK6 are members of the genus Bacillus. The results of numerical analysis based on phenotypic characteristic and chemical character of the three bacterial isolates producing PHB with reference strains showed that the PSA10 isolate bacterial identical with Bacillus megaterium, PPK5 isolate identical with Bacillus subtilis and PPK6 isolate identical with Bacillus cereus, and these results also support by the molecular phylogenetic analysis. Therefore, the polyphasic taxonomy is an effective approach to uncover the identity of the novel bacterial isolates

    Strengthening of two-way reinforced concrete slabs with Textile Reinforced Mortars (TRM)

    Get PDF
    An innovative strengthening technique is applied for the first time in this study to provide flexural strengthening in two-way reinforced concrete (RC) slabs supported on edge beams. The technique comprises external bonding of textiles on the tension face of RC slabs through the use of polymer-modified cement- based mortars. The textiles used in the experimental campaign comprised fabric meshes made of long stitch-bonded fibre rovings in two orthogonal directions. The specimens measured 2 x 2 m in plan and were supported on hinges at the corners. Three RC slabs strengthened by textile reinforced mortar (TRM) overlays and one control specimen were tested to failure. One specimen received one layer of carbon fibre textile, another one received two, whereas the third specimen was strengthened with three layers of glass fibre textile having the same axial rigidity (in both directions) with the single-layered carbon fibre textile. All specimens failed due to flexural punching. The load-carrying capacity of the strengthened slabs was increased by 26%, 53%, and 20% over that of the control specimen for slabs with one (carbon), two (carbon) and three (glass) textile layers, respectively. The strengthened slabs showed an increase in stiffness and energy absorption. The experimental results are compared with theoretical predictions based on existing models specifically developed for two-way slabs and the performance of the latter is evaluated. Based on the findings of this work the authors conclude that TRM overlays comprise a very promising solution for the strengthening of two-way RC slabs

    Strengthening of two-way reinforced concrete slabs with Textile Reinforced Mortars (TRM)

    Get PDF
    An innovative strengthening technique is applied for the first time in this study to provide flexural strengthening in two-way reinforced concrete (RC) slabs supported on edge beams. The technique comprises external bonding of textiles on the tension face of RC slabs through the use of polymer-modified cement- based mortars. The textiles used in the experimental campaign comprised fabric meshes made of long stitch-bonded fibre rovings in two orthogonal directions. The specimens measured 2 x 2 m in plan and were supported on hinges at the corners. Three RC slabs strengthened by textile reinforced mortar (TRM) overlays and one control specimen were tested to failure. One specimen received one layer of carbon fibre textile, another one received two, whereas the third specimen was strengthened with three layers of glass fibre textile having the same axial rigidity (in both directions) with the single-layered carbon fibre textile. All specimens failed due to flexural punching. The load-carrying capacity of the strengthened slabs was increased by 26%, 53%, and 20% over that of the control specimen for slabs with one (carbon), two (carbon) and three (glass) textile layers, respectively. The strengthened slabs showed an increase in stiffness and energy absorption. The experimental results are compared with theoretical predictions based on existing models specifically developed for two-way slabs and the performance of the latter is evaluated. Based on the findings of this work the authors conclude that TRM overlays comprise a very promising solution for the strengthening of two-way RC slabs

    Reverse engineering of mandible and prosthetic framework: Effect of titanium implants in conjunction with titanium milled full arch bridge prostheses on the biomechanics of the mandible.

    Get PDF
    This study aimed at investigating the effects of titanium implants and different configurations of full-arch prostheses on the biomechanics of edentulous mandibles. Reverse engineered, composite, anisotropic, edentulous mandibles made of a poly(methylmethacrylate) core and a glass fibre reinforced outer shell were rapid prototyped and instrumented with strain gauges. Brånemark implants RP platforms in conjunction with titanium Procera one-piece or two-piece bridges were used to simulate oral rehabilitations. A lateral load through the gonion regions was used to test the biomechanical effects of the rehabilitations. In addition, strains due to misfit of the one-piece titanium bridge were compared to those produced by one-piece cast gold bridges. Milled titanium bridges had a better fit than cast gold bridges. The stress distribution in mandibular bone rehabilitated with a one-piece bridge was more perturbed than that observed with a two-piece bridge. In particular the former induced a stress concentration and stress shielding in the molar and symphysis regions, while for the latter design these stresses were strongly reduced. In conclusion, prosthetic frameworks changed the biomechanics of the mandible as a result of both their design and manufacturing technology

    Index to NASA tech briefs, 1971

    Get PDF
    The entries are listed by category, subject, author, originating source, source number/Tech Brief number, and Tech Brief number/source number. There are 528 entries

    Aeronautical Engineering: A special bibliography with indexes, supplement 67, February 1976

    Get PDF
    This bibliography lists 341 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1976
    • …
    corecore