422 research outputs found

    Morphological changes of Bunni (Barbus sharpeyi) larvae in laboratory conditions

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    In this study, the early development of Bunni (Barbus sharpeyi) larvae was surveyed through morphological changes and measuring total length, standard length, head length, thickness of larvae, eye diameter and snout length. The initial period of the larval life can be divided into 2 phases: endogenous and exogenous food sources. During the first three days of the larvae development, there was a gradual yolk sac reduction until its complete absorption at the end of third day, indicating the necessity of exogenous feeding. From the fourth to eleventh day, the final development of the heart, gill, air bladder, fins and intestine were observed. Total length of newly hatched larvae was 6.26mm and total length of fifteen days larvae was 8.35mm. The larval development of Barbus sharpeyi was similar to other Barbus species

    More than one dynamic crossover in protein hydration water

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    Studies of liquid water in its supercooled region have led to many insights into the structure and behavior of water. While bulk water freezes at its homogeneous nucleation temperature of approximately 235 K, for protein hydration water, the binding of water molecules to the protein avoids crystallization. Here we study the dynamics of the hydrogen bond (HB) network of a percolating layer of water molecules, comparing measurements of a hydrated globular protein with the results of a coarse-grained model that has been shown to successfully reproduce the properties of hydration water. With dielectric spectroscopy we measure the temperature dependence of the relaxation time of protons charge fluctuations. These fluctuations are associated to the dynamics of the HB network of water molecules adsorbed on the protein surface. With Monte Carlo (MC) simulations and mean--field (MF) calculations we study the dynamics and thermodynamics of the model. In both experimental and model analyses we find two dynamic crossovers: (i) one at about 252 K, and (ii) one at about 181 K. The agreement of the experiments with the model allows us to relate the two crossovers to the presence of two specific heat maxima at ambient pressure. The first is due to fluctuations in the HB formation, and the second, at lower temperature, is due to the cooperative reordering of the HB network

    The embryonic development and formation of Bunnei (Barbus sharpeyi Gunther, 1874)

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    Understanding the embryogenesis of Bunni is a useful tool for finding the time and suitable environmental conditions for spawning, growth requirements and use of techniques to increase the growth rate and survival. The stages of embryonic development for Bunnei (Barbus sharpeyi) was investigated in 22°C. The reared brood stocks were spawned in captivity condition. The oocytes were spherical, brown and very adhesive. The cleavage was fast and the first division was recorded within 15-20 minutes after fertilization. The blastulation and gastrulation were investigated in 7:40 and 13:10 hours after fertilization with the yolk sac diameter of 1.18±0.061mm (Mean±SD), respectively. The organogenesis was started 21 hours after the fertilization, when the blastopore was closed and notochord was formed. The embryonic stages were continued by appearance the brain, the somites and the melanophores on the yolk sac. The heart was beaten and shown the blood circulation 65 hours after the fertilization. The head, tail and pectoral fins were moved frequently. The embryo reached to pre hatching and final hatching 79:10 and 84:10 hours after fertilization, respectively, and the embryo existed from corion with the length of about 5.29±0/121mm (Mean±SD)

    Functional Independence Measure in Iran: A Confirmatory Factor Analysis and Evaluation of Ceiling and Floor Effects in Traumatic Brain Injury Patients

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    Background: The functional independence measure (FIM) is one of the most important assessment instruments for motor and cognitive dependence in rehabilitation medicine; however, there is little data about its confirmatory factor analysis (CFA) and ceiling/floor effects from other countries and also in Iranian patients. Objectives: The aim of this study was to evaluate a two-factor model (motor and cognitive independence as latent variables) and ceiling/floor effects for FIM in Iranian patients with traumatic brain injuries (TBI). Patients and Methods: In this cross-sectional study, 185 subacute TBI patients were selected from emergency and neurosurgery departments of Poursina Hospital (the largest trauma hospital in northern Iran, Rasht) using the consecutive sampling method and were assessed for functional independence. Results: The results of this study showed that the floor effect was not observed; however, ceiling effects were observed for the FIM total score and its subscales. The confirmatory factor analysis showed that the chi-square/df ratio was 2.8 for the two-factor structure and the fit indices for this structural model including root mean square error of approximation (RMSEA) = 0.099, normed fit index (NFI) = 0.96, tucker lewis index (TLI) = 0.97, comparative fit index (CFI) = 0.97 were close to standard indices. Conclusions: Although ceiling effects should be considered for rehabilitation targets, the two-factor model of FIM (motor and cognitive independence) has an eligible fitness for Iranian patients with TBI

    The effects of Momordica charantia on liver function and histological structure

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    Introduction: The application of herbal plants because of their lower side-effects has been increasing in recent years. Objectives: we aimed to study the effects of hydro-alcoholic extract of Momordica charantia (bitter melon) on liver function and tissue structure in mice. Materials and Methods: This study was conducted on 70 male mice which were randomly designated into 7 groups of 10 and were injected with single doses of 0, 100, 500, 1000, 2000 and 4000 mg/kg and multiple daily dose of 500 mg/kg for 7 days, intraperitoneally. Finally, liver tissues were taken out for histological examinations. Serum samples were assayed for liver enzymes activities of alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase. Also the antioxidant activity of blood and bitter melon were measured. Subsequently, data were analyzed by analysis of variance (ANOVA) and Bonferroni tests using Stata software. Results: The results of the present study showed that a single dose of Momordica charantia fruit extract at doses up to 4000 mg/kg extract does not significant adverse effects on the liver enzymes and tissue structure. Conclusion: Using this drug for short time and low dose has not toxicity effects on liver enzymes activity and tissue structure, hence, it is safe in this range of doses

    Study of the effect of bacterial lipopolysaccharide on the structure and dynamics on mouse tubulin polymerization

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    Background and aims: In recent decades, there has been much research on the microtubule dynamics as well as on factors affecting it. According to different studies, lipopolysaccharide (LPS) is thought to play an indirect role in neurodegenerative diseases through enzymatic pathways which hyperphosphorylate Tau protein and dissociate it from microtubules. In the present study, it was aimed to assess the direct effect of LPS on the structure and dynamics of tubulin polymerization in vitro. Methods: In this study, mouse tubulins were purified through two cycles of temperature-dependent polymerization-depolymerization. Cellulose-phosphate chromatography was used to further purify tubulins. SDS-PAGE was used to analyze the purity of the tubulins. Circular dichroism (CD), intrinsic fluorescence and turbidity assays were used to assess the changes in secondary and tertiary structures, and the dynamics of tubulin polymerization in the presence of different concentrations of LPS (5pM, 5nM, 50nM, 0.5µM and 5µM), respectively. Results: SDS-PAGE analysis confirmed the purity of tubulins. The intrinsic fluorescence analysis and CD assay revealed the changes in the secondary and tertiary structures of tubulins in the presence of LPS. The results of turbidity assay indicated that LPS could reduce the polymerization of tubulins. Conclusion: Our results indicate that LPS is able to change the secondary and tertiary structures of tubulin and decreases tubulin polymerization. According to our results, lipopolysaccharide in addition to an indirect effect on the microtubules stability, as well as by decreases in tubulin polymerization could result in neurodegenerative diseases specially Alzheimer's diseases

    Scalable, cost-efficient synthesis and properties optimization of magnetoelectric cobalt ferrite/barium titanate composites

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    Cobalt ferrite (CoFe2O4)/barium titanate (BaTiO3) particulate composites exhibiting high magnetoelectric coefficients were synthesized from low-cost commercial precursors using mechanical ball milling followed by high-temperature annealing. CoFe2O4 (20 nm–50 nm) and either cubic or tetragonal BaTiO3 nanoparticle powders were used for the synthesis. It was found that utilizing a 50nm cubic BaTiO3 powder as a precursor results in a composite with a magnetoelectric coupling coefficient value as high as 4.3 mV/Oe cm, which is comparable to those of chemically synthesized core–shell CoFe2O4–BaTiO3 nanoparticles. The microstructure of these composites is dramatically different from the composite synthesized using 200nm tetragonal BaTiO3 powder. CoFe2O4 grains in the composite prepared using cubic BaTiO3 powder are larger (by at least an order of magnitude) and significantly better electrically insulated from each other by the surrounding BaTiO3 matrix, which results in a high electrical resistivity material. It is hypothesized that mechanical coupling between larger CoFe2O4 grains well embedded in a BaTiO3 matrix in combination with high electrical resistivity of the material enhances the observed magnetoelectric effect

    Scalable, cost-efficient synthesis and properties optimization of magnetoelectric cobalt ferrite/barium titanate composites

    Get PDF
    Cobalt ferrite (CoFe2O4)/barium titanate (BaTiO3) particulate composites exhibiting high magnetoelectric coefficients were synthesized from low-cost commercial precursors using mechanical ball milling followed by high-temperature annealing. CoFe2O4 (20 nm–50 nm) and either cubic or tetragonal BaTiO3 nanoparticle powders were used for the synthesis. It was found that utilizing a 50nm cubic BaTiO3 powder as a precursor results in a composite with a magnetoelectric coupling coefficient value as high as 4.3 mV/Oe cm, which is comparable to those of chemically synthesized core–shell CoFe2O4–BaTiO3 nanoparticles. The microstructure of these composites is dramatically different from the composite synthesized using 200nm tetragonal BaTiO3 powder. CoFe2O4 grains in the composite prepared using cubic BaTiO3 powder are larger (by at least an order of magnitude) and significantly better electrically insulated from each other by the surrounding BaTiO3 matrix, which results in a high electrical resistivity material. It is hypothesized that mechanical coupling between larger CoFe2O4 grains well embedded in a BaTiO3 matrix in combination with high electrical resistivity of the material enhances the observed magnetoelectric effect
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