174 research outputs found

    Applying the Taguchi method for optimized fabrication of bovine serum albumin (BSA) nanoparticles as drug delivery vehicles

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    The objective of the present study was to optimize the fabrication of bovine serum albumin (BSA) nanoparticle by applying the Taguchi method with characterization of the nanoparticle bioproducts.BSA nanoparticles have been extensively studied in our previous works as suitable carrier for drug delivery, since they are biodegradable, non-toxic and non antigenic. A statistical experimental designmethod (Taguchi method with L16 orthogonal array robust design) was implemented to optimize experimental conditions of the purpose. Agitation speed, initial BSA concentration, pH and temperaturewere considered as process parameters to be optimized. As the result of Taguchi analysis in this study, temperature and agitation speed were the most influencing parameters on the particle size. Theminimum size of nanoparticles (~74 nm) were obtained at 4°C, pH 7.5, 15 mg ml-1 BSA concentration and agitation speed of 500 rpm. As for characterization of the products, Atomic Force microscopy(AFM), Scanning Electron microscopy (SEM) and Sodium Dodecyl Sulphate- Poly Acrylamide Gel Electrophoresis (SDS-PAGE) as well as Fourier Transform Infra-Red (FTIR) techniques were employed

    Production of Chitin and Chitosan from Shrimp Shell in Batch Culture of Lactobacillus plantarum

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    Lactobacillus plantarum, as a potential lactic acid and protease producer, was used for biological extraction of chitin from shrimp shell. L. plantarum was grown in a batch culture containing shrimp shell powder and date syrup, incubated at 30 °C. The produced organic acids and proteases in L. plantarum culture were able to demineralize and deproteinize shrimp shell. Percentages of deproteinization and demineralization were 45 and 54, respectively. In post treatment of the sample, dilute acid and alkali, were implemented to produce the specific chitin. Chitin was converted to chitosan by N-deacetylation with NaOH solution. Percentage of deacetylation based on FTIR spectrum was 83 %

    Fabrication of multifunctional microfibrous and nanofibrous cellulose carriers and comparison of cell adhesion and spreading potential on them

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    Fibrous biomaterials have received much attention in tissue engineering and regenerative medicine due to their morphology, resembling extracellular matrix. In comparison to synthetic fibers, cellulose based fibers have interesting properties for cellular applications such as biodegradability, biocompatibility, simple preparation and their potential for chemical modification. Among cellulose derivatives, carboxymethyl cellulose and quaternized cellulose are the most important and valuable cellulose ethers which have anionic and cationic surface charge. In this research, we report the fabrication of multifunctional cellulose microfibrous and nanofibrous scaffolds and the comparison of adhesion and spreading potential of human fibroblast cell on them. The fabricated fibrous scaffolds were characterized by several instrumental techniques. The results showed that multifunctional cellulose nanofibers and microfiber had 8.6 and 8.2 mV surface potential, 7.1 and 6.8 MPa tensile strength, 560 and 510 MPa Young modules, 610 and 595 water uptake and 41o and 44o contact angle, respectively. The MTT assay showed that proliferation of fibroblast cells was enhanced in nanofibrous, compared to microfibrous mat. The SEM analysis of fixed cells on scaffolds showed that cells spreading on nanofibrous samples became more noticeable than microfibrous ones. © 2020 by the authors

    The Environmental Effect on Spawning Time, Length at Maturity and Fecundity of Kutum (R u t i l u s f r i s i i k u t u m , Kamensky, 1901) in Southern Part of Caspian Sea, Iran

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    Fish sampling were carried out using beach seines during the fishing season from early October 2006 to mid April 2007. The gonadosomatic indexes (GSI) in range and average for female and male were 0.03 to 40.28 (5.70 ± 6.48) and 0.13 to 16.71 (3.39 ± 2.33), respectively. The GSI indicated that the reproductions of R. f. kutum were occurred during March-April, with the highest average value of 6.52 for males and of 17.00 for females in April. Fifty percent of length maturity (Lm50%) at FL = 37.78 cm was recorded. The absolute fecundity ranged from 15,723 for a three-year old to 130,737 eggs for an eight-year old female, with a mean of 60435 ± 24889. The relationship between fecundity (F) and fork length (cm) was represented by the formula: Fec. = 6616FL+25916. The von Bertalanffy growth parameters was: L∞=67.5cm, K=0.21 year-1, t0 =-0.10 for throw population of kutum. The maximum spawning migration into the rivers based on GSI occurred significantly in April but it may effects by environment of sea water layers. The results showed that the length at first maturity and fecundity of R. f. kutum is reduced in southern part of Caspian Sea

    Rotating biological contactors : a review on main factors affecting performance

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    Rotating biological contactors (RBCs) constitute a very unique and superior alternative for biodegradable matter and nitrogen removal on account of their feasibility, simplicity of design and operation, short start-up, low land area requirement, low energy consumption, low operating and maintenance cost and treatment efficiency. The present review of RBCs focus on parameters that affect performance like rotational speed, organic and hydraulic loading rates, retention time, biofilm support media, staging, temperature, influent wastewater characteristics, biofilm characteristics, dissolved oxygen levels, effluent and solids recirculation, stepfeeding and medium submergence. Some RBCs scale-up and design considerations, operational problems and comparison with other wastewater treatment systems are also reported.Fundação para a Ciência e a Tecnologia (FCT

    Heterodinuclear ruthenium(II)-cobalt(III) complexes as models for a new approach to selective cancer treatment

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    Heterodinuclear ruthenium(ii)-cobalt(iii) complexes have been prepared as part of investigations into a new approach to selective cancer treatment. A cobalt(iii) centre bearing amine ligands, which serve as models for cytotoxic nitrogen mustard ligands, is connected by a bridging ligand to a ruthenium(ii)-polypyridyl moiety. Upon excitation of the ruthenium centre by visible light, electron transfer to the cobalt(iii) centre results in reduction to cobalt(ii) and consequent release of its ligands. We have synthesised several such structures and demonstrated their ability to release ligands upon excitation of the ruthenium centre by visible light

    The percentage determination of Rutilus frisii kutum (200, 500 and 1000 mg) resistance to salinity, turbidity and decrease of oxygen by usage of the river water at the releasing meantime

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    The survey effect of salinity, turbidity and dissolved oxygen performed on Rutilus frisii Kutum juveniles with aim, which was determined about survival rate and histological changes in gill and kidney tissues. Juveniles provided from the Rajai's fish propagation center and then examined in Caspian Sea Ecology Research Center laboratory. The juveniles were investigated on three weight group (200-75%) had shown in 400-<600mg weight group with dissolve oxygen: 3.8±0.15SE mg/l. In addition, the lowest survival rates under turbidity stress (95.83%) had shown that in weight group less than 400 mg with turbidity 15600 FTU. Therefore, survival of juveniles was high. However, gill tissue of juveniles under turbidity and salinity stress became short (necrosis) and thick (edema and hyperplasia) in the end of experiments. The juveniles gill tissues were not changes in the river clear freshwater. Therefore, the factors of gill tissue deformation were salinity and suspended particles in the water. However, the structures of kidney in the different groups of juveniles were similar. Nevertheless, juveniles glomerular diameter increased with increasing weight (p<0.05, Duncan test). Furthermore, there was a increasing the internal cavity of the proximal and distal tubules and decreasing of glomeruli in diameter in the transfer of juveniles from freshwater to brackish water. Although the survival rate of juveniles is acceptable in this study, but there was abnormal changes in the structure of them gills. It appears that this change will cause a disruption in trend of juvenile's growth

    Proton Transfer, Hydrogen Bonding, and Disorder: Nitrogen Near-Edge X-ray Absorption Fine Structure and X-ray Photoelectron Spectroscopy of Bipyridine-Acid Salts and Co-crystals

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    The sensitivity of near-edge X-ray absorption fine structure (NEXAFS) spectroscopy to Brønsted donation and the protonation state of nitrogen in the solid state is investigated through a series of multicomponent bipyridine–acid systems alongside X-ray photoelectron spectroscopy (XPS) data. A large shift to high energy occurs for the 1s → 1π* resonance in the nitrogen K-edge NEXAFS with proton transfer from the acid to the bipyridine base molecule and allows assignment as a salt (C═NH+), with the peak ratio providing the stoichiometry of the types of nitrogen species present. A corresponding binding energy shift for C═NH+ is observed in the nitrogen XPS, clearly identifying protonation and formation of a salt. The similar magnitude shifts observed with both techniques relative to the unprotonated nitrogen of co-crystals (C═N) suggest that the chemical state (initial-state) effects dominate. Results from both techniques reveal the sensitivity to identify proton transfer, hydrogen bond disorder, and even the potential to distinguish variations in hydrogen bond length to nitrogen
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