83 research outputs found

    Effects of Diazinon concentrations on LC50, hematocrit and clinical signs of Roach Torkemani (Rutilus rutilus caspius) fries of Caspian Sea

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    Effects of different concentrations of Diazinon on Roach Torkemani (Rutilus rutilus caspius) fries supplied from Ghareh-Soo Fishery Research Station was studied in Gorgan University of Agricultural Science and Natural Resources in 2009 to determine 50% lethal concentration (LC50) for the fish within 96 hours. In this study, 126 Roach fries with mean weight of 3 grams were used. Tests were performed statically based on instructions of O.E.C.D under fixed water quality conditions at the temperature 24±1 and pH 8-8.5 in a completely random trial with five concentrations treatments of Diazinon (5, 5.95, 7.07, 8.48 and 10mg/l) in three replications and the means were compared using Duncan test at 5% significance level. The results indicated that at the end of 96-hour test, LC50 was 7.88mg/l. In this test, clinical signs such as hunched spinal column, thrilling, clot in caudal fin and head, and irregular swimming were observed in the studied fish specimens. In hematological examination, there was a remarkable decrease in percent of hematocrit between concentrations of 5 and 5.95mg/l of Diazinon. By increasing the concentration of this poison, the decrease became slower.Furthermore, there was a significant difference in percent of hematocrit between control group and LC50 group, with mean amounts of 36 and 27%, respectively. Based on the results, Diazinon was classified as toxic pesticide for Roach Torkemani

    Zinc- and Copper-Doped Mesoporous Borate Bioactive Glasses: Promising Additives for Potential Use in Skin Wound Healing Applications

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    In this study, zinc (Zn)- and copper (Cu)-doped 13-93B3 borate mesoporous bioactive glasses (MBGs) were successfully synthesized using nitrate precursors in the presence of Pluronic P123. We benefited from computational approaches for predicting and confirming the experimental findings. The changes in the dynamic surface tension (SFT) of simulated body fluid (SBF) were investigated using the Du Noüy ring method to shed light on the mineralization process of hydroxyapatite (HAp) on the glass surface. The obtained MBGs were in a glassy state before incubation in SBF. The formation of an apatite-like layer on the SBF-incubated borate glasses was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The incorporation of Zn and Cu into the basic composition of 13-93B3 glass led to changes in the glass transition temperature (Tg) (773 to 556 °C), particle size (373 to 64 nm), zeta potential (−12 to −26 mV), and specific surface area (SBET) (54 to 123 m2/g). Based on the K-means algorithm and chi-square automatic interaction detection (CHAID) tree, we found that the SFT of SBF is an important factor for the prediction and confirmation of the HAp mineralization process on the glasses. Furthermore, we proposed a simple calculation, based on SFT variation, to quantify the bioactivity of MBGs. The doped and dopant-free borate MBGs could enhance the proliferation of mouse fibroblast L929 cells at a concentration of 0.5 mg/mL. These glasses also induced very low hemolysis (<5%), confirming good compatibility with red blood cells. The results of the antibacterial test revealed that all the samples could significantly decrease the viability of Pseudomonas aeruginosa. In summary, we showed that Cu-/Zn-doped borate MBGs can be fabricated using a cost-effective method and also show promise for wound healing/skin tissue engineering applications, as especially supported by the cell test with fibroblasts, good compatibility with blood, and antibacterial properties

    Fabrication and characterization of cobalt- and copper-doped mesoporous borate bioactive glasses for potential applications in tissue engineering

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    Developing novel compositions of bioactive glasses (BGs) is key for accelerating tissue repair and regeneration. In this work, we developed a series of cobalt (Co)- and copper (Cu)-doped mesoporous bioactive glasses (MBGs) based on borate 13-93B3 composition using nitrate precursors. We took benefit from data science algorithms to predict and assess the physico-chemical and biological properties of the samples. The results showed that the presence of the dopants (Co and Cu) in the MBGs could change the glass transition temperature (Tg) (from 773 to 539 °C), the zeta potential (from -12 to -43 mV), and surface area (from 54 to 194 m2/g). However, the presence of 2.5 mol% of dopants in the composition led to just a slight decrease in their bioactivity. In vitro biocompatibility assays confirmed that all the glass samples were biocompatible. Furthermore, the doped MBGs exhibited potent antibacterial activity against both Gram-positive and Gram-negative bacteria. In addition, these glasses could induce the mobility of human umbilical vein endothelial cells (HUVECs) and enhance new blood vessel formation in ovo. According to the obtained data, it can be stated that this type of doped borate MBGs held great promise in tissue engineering applications

    Efficient inhibition of human immunodeficiency virus replication using novel modified microRNA-30a targeting 3'-untranslated region transcripts

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    RNA interference (RNAi)-based gene therapy is currently considered to be a combinatorial anti-human immunodeficiency virus-1 (HIV-1) therapy. Although arti­ficial polycistronic microRNAs (miRs) can reduce HIV-1 escape mutant variants, this approach may increase the risk of side effects. The present study aimed to optimize the efficiency of anti-HIV RNAi gene therapy in order to reduce the cell toxicity induced by multi-short hairpin RNA expression. An artificial miR-30a-3'-untranslated region (miR-3'-UTR) obtained from a single RNA polymerase II was used to simultaneously target all viral transcripts. The results of the present study demonstrated that HIV-1 replication was signifi­cantly inhibited in the cells with the miR-3'-UTR construct, suggesting that miR-3'-UTR may serve as a promising tool for RNAi-based gene therapy in the treatment of HIV-1. © 2016, Spandidos Publications. All Rights Reserved

    Peptone production from marine and culture wastes by commercial enzymes for bacterial culture media

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    Thirty to 40% of total fish catch is converted to waste. Using different methods of hydrolysis of the protein can be recovered of fish waste and increase the amount of protein efficiency. In this study, the four enzymes Alcalase, protamex, pepsin and trypsin were used for hydrolysis of four fish species including common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix), grass carp (Ctenopharyngodon idella) and the Big head (Hypophthalmichthys nobilis). The effects of pH, temperature and hydrolysis time on the rate of hydrolysis were studied on soluble proteins and degree of hydrolysis (phase I). In the second step, proximate factors of peptone been evaluated and eventually replace commercial peptone media MRS (Lactobacillus plantarum, Lactobacillus delberuki, Lactobacillus casei, Streptococcus thermophilus) and TSB (Listeria monocytogenes, two species of Bacillus and Pseudomonas, Streptococcus faecium) and the optical density of bacteria at different times were compared with control samples. Results showed that the highest degree of hydrolysis and soluble proteins were referred to alcalase and protamex, pepsin and trypsin respectively. The highest value of hydrolysis, in all treatments, was attributed to grass carp and silver carp, common carp and big head respectively. The best pH and temperature for alcalase, protamex, pepsin and trypsin 8.5and 55, 7.5 and 55, 3.5, 37, 7 and 37 respectively. Best time to achieve the highest degree of hydrolysis and soluble protein was 90 minutes. Qualitative analysis showed that the highest and lowest amounts of protein and fat in the treatment of alcalase (about 70 % protein and less than 0.5 % fat) and protamex, pepsin and trypsin was then. The results of bacteria culture showed that the highest percentage growth of lactic acid bacteria was referred to Streptococcus thermophilus and Lactobacillus casei had the lowest rate of growth. In other bacteria, Pseudomonas and Bacillus species were the highest percentage of growth and Listeria monocytogenes and Streptococcus faecium respectively. In all treatments, alcalase had the best results and the peptone prepared from fish waste grass carp had the best condition for growth of used bacteria. It seems that the initial substrate , the parameters used such as temperature, pH, and enzyme hydrolysis time , have a significant effect on the quality of peptone and protein content in the final product is determined value of protein for culture of bacteria

    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

    Short communication. Impact of the amino acid proline on the cold hardiness of honey bee, Apis mellifera L.

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    Like many insects, honey bee can increase its cold tolerance through freeze avoidance, using antifreeze proteins (AFPs) to lower its supercooling point (SCP). Proline is the most dominant amino acid in honey bee hemolymph, which can be obtained by the insect through feeding. In the current study the antifreeze activity of this amino acid was evaluated on worker honey bees, immediately before the start of cold season. The experiment was established on four treatments including three different concentrations of proline (1%, 3% and 4.35%) diluted in 1:1 water sucrose syrup, and the syrup without proline (control). Newly emerged worker honey bees were fed on the mentioned diets for 2 weeks, under cage condition, and then 20 bees from each treatment (cage) were selected randomly for determination of cold hardiness inside a cooling bath. Using a CHY data logger, equipped with a K100 sensor attached to the bee’s gaster, the SCP, the amount of released heat and the rate of this release as measures of insect cold hardiness were recorded. Proline significantly reduced honey bees’ SCP. The lowest point, -7.67±0.2646°C, was observed in the concentration of 1% proline. The amount of released heat and the rate of this release were not significantly different across the treatments

    Free-Fall Gravity Drainage in Fractured Matrix Blocks: Experimental and Network Modeling Simulation Findings and Observations

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    Document ID: 107206-MS Abstract Free Fall Gravity Drainage as an important recovery mechanism was investigated and analyzed experimentally and by numerical (network model) simulation. Sets of glass micromodels with real pattern of porous media and two numerical network model simulators were prepared in forms of fractured and non-fractured models to study and analyze the Free Fall Gravity Drainage recovery mechanism experimentally and by simulation. After validating the network model simulator, analysis of experimental and simulation results leads to some interesting findings and observations as follow: Based on network modeling simulation, direction of flow through fracture network shows that the oil in the middle horizontal fracture usually flows from one end of fracture to the other end, however in relatively small fracture apertures the oil from both vertical fractures at the ends of middle horizontal fracture flows into the horizontal fracture and then sinks downward to the lower matrix block. This means in relatively small fracture apertures, block to block interaction coefficient (a) reaches to 100%. Another point is that, it was observed from network model simulation data that this critical fracture aperture is a function of pore and throat sizes. Also, experimental and simulation results confirm that there is no break through of gas in free fall gravity drainage process. In addition a new mathematical approach (by means of flow potential and control volume concepts) to block to block interaction effects (Capillary Continuity and Reinfiltration phenomena) is presented to explain and interpret the mechanism of occurrence of these phenomena. This approach proves mathematically that decreasing the fracture aperture leads to increasing the fracture capillary pressure which in turn intensifies the feeding rate of liquid bridge (in the middle horizontal fracture) from upper block and lowers the discharging rate of liquid bridge from lower matrix block. Therefore, the liquid bridge can be more stable between the matrix blocks. As a result, fracture capillary pressure has positive effect on oil recovery from matrix blocks. Finally, a new approach for determination of the matrix block threshold heights at the end of free fall gravity drainage is presented and used to prove that matrix block threshold height inreases with increasing the matrix block height. Also, it will be proved that matrix block recovery factor increases with increasing the matrix block height although matrix block threshold height increases too. Introduction Multiphase flow in porous media at pore-scale is of great importance in many fields like hydrology, contaminant cleanup and petroleum engineering. Visualization of fluid flow at pore-scale is performed by using glass micromodels and network modeling tries to simulate (model) this physical process by reconstructing the porous media as a network of pores and throats and applying the governing rules to the transport and arrangement of fluids. Macroscopic properties like capillary pressure, electrical resistively or relative permeability can then be estimated across the network 4,5,10,11,16–19. At the first step, visualization and numerical simulation of free fall gravity drainage in single matrix and fractured blocks models was performed by the current authors that has been fully described in the previous paper 12. In the current paper, some of the main experimental and network modeling simulation features and findings of free fall gravity drainage process in fractured blocks model are discussed. Modeling of flow behavior using network models was pioneered by Fatt 1–3 in the 1950s. By distributing the pores and throats on a regular 2D lattice he was able to produce capillary pressure and relative permeability curves for drainage (as a function of average saturation) that had the same characteristics as those obtained experimentally. Laroche 7 et al developed a pore network model to predict the effects of wettability heterogeneities with different patterns and spatial distributions on displacement mechanisms, sweep efficiency, and fluid distribution in gas injection into oil and water. The presented network model simulator in this paper has similar pore and throat shapes to Laroche's network model. Alireza Mollaei, M. Haghighi, and B. Main
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