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排序方式: 共有77条查询结果,搜索用时 31 毫秒
1.
In the eggs of the brown trout, Salmo trutta fario, lipid droplets are clearly visible beneath the oolemma on the surface of the protein yolk. When examining the distribution of lipid vesicles in egg batches of different quality, four categories of lipid vesicle distribution could be distinguished: In the first category, the lipid droplets were evenly distributed throughout the egg. These egg batches had a high quality (percentage of eggs developing to eyed stage embryos: 96.2 ± 5.2). Some lipid droplets had the tendency to coalesce in one pole of the egg in the second category. This coalescing of lipid droplets was accompanied with a reduction in egg quality to about 50% of the first category (% of eyed stage embryos: 40.6 ± 15.2). In the last two categories, the lipid droplets were mostly coalesced in one or two poles of the egg and the egg quality was very low (% of eyed stage embryos: 3.3 ± 2.9 and zero, respectively). In conclusion, examination of lipid droplets distribution, in brown trout, can distinguish between high and low quality eggs in an easy and reliable way. 相似文献
2.
Pérez-Sánchez T Balcázar JL García Y Halaihel N Vendrell D de Blas I Merrifield DL Ruiz-Zarzuela I 《Journal of fish diseases》2011,34(7):499-507
A study was conducted to evaluate the probiotic properties of endogenous rainbow trout microbiota against pathogenic Lactococcus garvieae. A total of 335 bacterial strains were isolated from rainbow trout and screened for antagonistic activity against L. garvieae using an agar spot assay. Antagonistic strains were grouped by PCR amplification of repetitive bacterial DNA elements (rep‐PCR) and identified by 16S rRNA gene sequence analysis. The results revealed that the antagonistic strains belonged to the genera Lactobacillus, Lactococcus and Leuconostoc. Further probiotic characteristics, such as specific growth rate, doubling time, resistance to biological barriers, antibiotic resistance, hydrophobicity and production of antimicrobial substances, were also studied. These strains were able to survive low pH and high bile concentrations, showed good adherence characteristics and a broad spectrum of antibiotic resistance. The antagonistic efficacy was maintained after sterile filtration and was sensitive to proteinase K, indicating that proteinaceous extracellular inhibitory compounds were at least partially responsible for pathogen antagonism. Based on these results, these strains should be further studied to explore their probiotic effects in challenge experiments in vivo. This study shows clear evidence that the indigenous trout‐associated microbiota may provide a defensive barrier against L. garvieae. 相似文献
3.
The regeneratable forms of pollutant metals in lake sediments were estimated using different chemical extractants and the effects of lake acidification on the mobilization of such metal fractions studied in laboratory microcosm. The release of each metal was found to increase exponentially below a threshold pH value, which was about 4.0 for Cu, Ni, Zn, Cd and Fe. The data suggest that a large percentage of pollutant metals are mobile as determined by chemical extraction techniques and long-term release experiments. 相似文献
4.
Bouhallab S Cinga V Aít-Oukhatar N Bureau F Neuville D Arhan P Maubois JL Bouglé D 《Journal of agricultural and food chemistry》2002,50(24):7127-7130
The influence of the origin and kind of caseinophosphopeptide (CPP) on iron absorption was assessed by comparing a commercially available CPP mixture (CPPs) and derived chromatographic fractions with the purified, chemically phosphopeptide of beta-casein [beta-CN(1-25)] using a perfused rat duodenal loop system; gluconate iron was used as control. Only iron complexed to beta-CN(1-25) displayed a better bioavailability than gluconate iron. The results obtained with various chromatographic fractions indicated that phosphopeptides of different origins (alpha(s)- versus beta-caseins) display specific effects. These findings contribute to the explanation of the discrepancy about the role of caseinophosphopeptides on mineral bioavailability in vivo. 相似文献
5.
Hailat N 《Journal of veterinary medical education》2005,32(2):151-155
The veterinary profession and veterinary education stand, in the Arab world and worldwide, in the middle of many changes resulting from rapid communication, explosion of large amounts of information, international traffic of people, animals, and animal products, flow of capital, recent political changes, and new threats to global public health. These changes have put more pressure on veterinary leaders and educators to reconsider the different programs, projects, attitudes, and methodologies of thinking in faculties and institutes of veterinary medicine. 相似文献
6.
Moselhy WA Helmy NA Abdel-Halim BR Nabil TM Abdel-Hamid MI 《Reproduction in domestic animals》2012,47(2):335-343
The aim of the current study was to evaluate reproductive disorders concomitant with aluminium chloride (AlCl3) toxicity in Albino male rats. Attention was also directed to study the protective influence of ginger against this toxicity. Forty‐five mature Albino Wistar male rats were equally divided into three groups; the first group was served as control group while those of the second group (AlCl3) were daily treated with 34 mg/kg bw. AlCl3 orally. The third group (AlCl3 + ginger) was treated daily with AlCl3 as in group 2 in combination with ginger (40 mg/kg bw), which started 2 weeks prior to AlCl3. Five animals from each group were sacrificed on days 30, 45 and 60 of treatment. AlCl3 administration significantly decreased serum testosterone levels, increased testicular homogenate malondialdehyde and deteriorated semen picture with increased testicular DNA fragmentation. Histopathological examination revealed degenerative changes of the seminiferous tubules with focal areas of necrosed spermatogenic cells, marked degeneration and desquamation of the lining epithelial cells of epididymis as well as multiple calcified material in prostate gland following 60 days of aluminium treatment. Ginger treatment started to improve significantly all studied parameters after 60 days as compared with AlCl3‐treated group. In the current study, it was concluded that AlCl3 had a destructive effect on all the studied reproductive parameters. Treatment with ginger has an ameliorating effect against AlCl3 toxicity after 60 days post‐treatment. 相似文献
7.
Marina Hidalgo Isabel Prieto Hikmate Abriouel Ana Belén Villarejo Manuel Ramírez-Sánchez Antonio Cobo Nabil Benomar Antonio Gálvez Magdalena Martínez-Cañamero 《Plant foods for human nutrition (Dordrecht, Netherlands)》2018,73(1):1-6
Fat type in diet is responsible for specific changes in gut microbiota (GM). Extra virgin olive oil (EVOO) has been shown to be beneficial for blood pressure and to produce effects on GM. To analyze the cause-effect relationship between intestinal microbial changes and blood pressure, we studied the effect of EVOO on fecal microbiota and systolic blood pressure (SBP) levels in spontaneously hypertensive rats (SHR). SHR were fed either an enriched EVOO diet or a standard diet for a period of 12 weeks. At the end of the experimental period, the microbial profiles in the feces were studied in both groups by using PCR-denaturing gradient gel electrophoresis. Real-time PCR was used to quantify the selected bacterial groups. The results demonstrated significant differences when using Lactobacillus (p<0.05), clostridia XIV (p<0.01) and universal (p<0.05) primers. A significant (r=?0.475; p=0.04) inverse correlation between the abundance of clostridia XIV and SBP, which depends on the type of diet, was also observed. Finally, the results suggested an increase in the microbial diversity of the feces of the animals fed the EVOO diet. These results strongly connect the pattern of GM in SHR fed a diet enriched with EVOO to the lower levels of SBP observed in these animals at the end of the feeding period. 相似文献
8.
Hamed Elsayed Rasha Attia Ola Mohamed Ahmed Haroun Nabil El-Sayed 《Fibers and Polymers》2018,19(4):832-842
Leather finishing processes using toxic organic solvent based produce volatile organic compounds (VOC), chronic exposure to this chemicals effect on workers' health causing many diseases especially lung cancer. So, polyurethane waterbased was synthesized for application in leather finishing instead of organic solvent based because it’s economic and safety for industry and workers. Preparation of water-based polyurethane (PU) depends on the reaction of polyethylene glycol (PEG, 300) with isophorone diisocyanate (IPDI) and the reaction of IPDI-1,4-butanediol (BDO) together with dimethylolpropionic acid (DMPA), was synthesized by poly-addition polymerization reaction. PU was then modified with different amounts of silicon dioxide nanoparticles (1-5 % SiO2), used as a binder in leather finishing. Leather coated was characterized physically, chemically and thermally by FTIR, GPC, DLS, TEM, SEM and TGA. The results revel that, water vapor permeability (WVP) of leather coated with PU modified with SiO2 showed improvement due to the existence of SiO2 particles which increases the interspaces of the polyurethane coating. SEM showed that when the amount of SiO2 nanoparticles increases, there is uniform nanoparticles accumulated can be observed. EDX prove the presence of Si and O2 elements and the formation of SiO2 nanoparticles. Mechanical properties discussed that tensile strength; tear strength and elongation at break % increase with increase SiO2 concentration until 3 % SiO2 nanoparticles. TGA showed an improvement of thermal stability of coated leather modified with SiO2. Therefore, this study succeeded in preparation of safe, ecofriendly of water-based polyurethane binders which modified with SiO2 for using in leather finishing. 相似文献
9.
The present study has investigated the effects of Orchis antolica (dose of 400 mg/kg/Body Wight) on female rats reproductive system for two time periods 4 and 12 weeks. Forty adult female Sprague-Dawley rats were divided into two treatment and two control groups of 10 rats each. The two treated groups received 400 mg/kg/body weight of Orchis antolica for two periods of 4 and 12 weeks. Female rats were allowed mating with untreated males when treatment ended. Pregnancy parameters such as: total number of pregnancy, body weight, reproductive organ weight, number of implantation sites, number of resorption sites and number of viable fetuses. The significance of these results was calculated using student's "t" and Chi- square tests. Treatment with Orchis antolica for 4 weeks did not have any significant effects on most parameters investigated except for a slight increase in the relative ovarian and embryo weights. Orchis antolica for 12 weeks induces a significant increased in the percentage of pregnancies and the number of implantation sites when compared with controls. Further, an increase in ovarian weights and in viable fetuses count was also observed. Histological sections of treated female ovaries were found to have an empty blood vessels within the cortical and modularly regions. We also noted an increased in the developing follicles at primary and secondary stages in addition to an absence of degenerative areas and increased cellularity in medulla. Long-term treatment with Orchis antolica might lead to diversified positive effects on fertility and pregnancy in female rats. 相似文献
10.