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A low molecular weight poly(ethyleneoxide)-poly(butadiene) (PEO-PB) diblock copolymer containing 50 weight percent PEO forms gigantic wormlike micelles at low concentrations (<5 percent by weight) in water. Subsequent generation of free radicals with a conventional water-based redox reaction leads to chemical cross-linking of the PB cores without disruption of the cylindrical morphology, as evidenced by cryotransmission electron microscopy and small-angle neutron scattering experiments. These wormlike rubber micelles exhibit unusual viscoelastic properties in water. 相似文献
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Expression profiles of immunity and reproductive genes during transition period in Holstein cattle 
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下载免费PDF全文 AI Ateya MS Hussein HM Ghanem RM Saleh WB El‐Domany YY Elseady 《Reproduction in domestic animals》2018,53(2):352-358
The transition period is a critical time for dairy cows as the animal is subjected to the physiological stress accompanying parturition. Immunosuppression and health status were examined during this period in 80 Holstein cows. Blood samples were taken from each cow 3, 2 and 1 week before and after calving, and at calving (0 day). RNA was extracted and subjected to real‐time PCR to determine mRNA levels for the immune‐related genes TLR 2, 4, 6, 7 and β‐defensin 5 in addition to the reproduction‐related genes prolactin and IGF‐I. Results showed significant up‐regulation of pro‐inflammatory‐selected genes, TLR 4, 6 7 and β‐defensin 5 at the third‐week post‐calving; however, earlier periods had lower expression of such genes. In contrast, the immunosuppression biomarker TLR2 gene was up‐regulated at calving and 1 week after parturition and then down‐regulated again at second and third week. Prolactin and IGF‐I genes expression levels were significantly and gradually increased mainly post‐partum. This research highlights that the expression patterns of TLRs, BNBD5, PRL and IGF‐I could be biomarkers to follow up immune and reproductive status of dairy cow at peri‐parturient period to predict the most susceptible risk time for disease incidence and to build up management protocol. 相似文献
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YY Liang DN Ye C Laowtammathron T Phermthai T Nagai T Somfai R Parnpai 《Reproduction in domestic animals》2011,46(1):e67-e73
The objective of this study was to optimize the activation protocol for buffalo oocytes after intracytoplasmic sperm injection (ICSI). The release of the second polar body (PB) at 3, 6 and 9 h after ICSI of in‐vitro matured oocytes activated either with 5 μm ionomycin (Io) or with 7% ethanol (EtOH) was preliminary examined. The highest rate of second PB extrusion occurred at 3 h of activation, and the second PB extrusion in EtOH group was significantly higher than that in Io group. Oocytes that extruded the second PB were selected and cultured either with 1.9 mm 6‐dimethylaminopurine (6‐DMAP) for 3 h or with 10 μg/ml cycloheximide (CHX) for 5 h. Significantly higher rate of oocytes formed 2 pronuclei in EtOH combined with CHX (EtOH + CHX) (62%) group compared to those of Io + CHX (42%) and EtOH + 6‐DMAP (48%) groups (p < 0.01) whereas Io + 6‐DMAP group showed intermediate value (58%). Significantly higher blastocyst formation rates were obtained in Io + 6‐DMAP (29%) and EtOH + CHX (24%) groups than in Io + CHX (6%) and EtOH + 6‐DMAP (17%) groups. Our results indicate that buffalo ICSI oocytes are effectively activated by combination treatment of Io with 6‐DMAP and EtOH with CHX resulting in the highest cleavage and blastocyst formation rates. 相似文献
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Mummed YY 《Tropical animal health and production》2012,44(4):785-790
Daily milk yield of Ogaden cattle was estimated from milk suckled by 269 calves born and maintained between 1994 and 2004
at Haramaya University Beef Farm, Ethiopia. The weigh–suckle–weigh method and the growth of calves were used to estimate the
yield. Mean predicted daily milk yield of the breed based on the weigh–suckle–weigh method was 4.39 ± 0.03 kg day−1. Daily milk yield estimated from the growth of calves up to 3 months of age was 4.59 ± 1.43 kg day−1. The milk yield was significantly affected by seasons of calving (p < 0.001), parities of the dams (p < 0.05), weeks of lactation (p < 0.001) and birth weights of calves (p < 0.05). A relatively higher milk yield was observed from cows calved during the long rain season. A higher milk yield was
produced by cows in fifth parity. Heavier calves at birth suckled more milk than lighter calves. Daily milk yield was significantly
higher in 3–6 weeks of lactation. The result of this study indicated that the milk yield produced by Ogaden breed was relatively
higher than the yield of some Zebu breed measured by partial suckling system in Ethiopia and was comparable to the yield from
Zebu cattle in the tropics estimated by the same method. 相似文献
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Q Fang J Wang YY Hao H Li JX Hu GS Yang JH Hu 《Reproduction in domestic animals》2017,52(6):1061-1066
Microbial environment is one of the important factors that affect the quality of preserved semen. Iodine methionine (IM), participating in the production and activation of metabolic enzymes, is a new type of amino acid chelate. To date, there has been no report to evaluate the effects of IM on boar semen preservation at 17°C. This study was designed to investigate the effects of IM on boar sperm quality and reproductive performance during liquid storage at 17°C and its antibacterial effect. Semen samples collected from six Yorkshire boars were diluted with basic liquid containing different concentrations of IM (0, 20, 40, 80, 160 and 320 μM). Subsequently, sperm motility, plasma membrane integrity and acrosome integrity were determined. After 6 days of preservation, the difference in microbial composition between control group and 80 μM IM group was compared using 16S rDNA sequencing, and the effects of IM on reproductive performance were also compared and analysed between the two groups. The results demonstrated that 20, 40 and 80 μM IM improved boar sperm motility, plasma membrane integrity and acrosome integrity. 80 μM IM was the optimum concentration. Conversely, 160 and 320 μM IM resulted in deleterious consequences to boar sperm quality compared to the control group and other treatment groups (p < .05). After 6 days of preservation, sperm motility, plasma membrane integrity and acrosome integrity were 56.0%, 51.8% and 59.4%, respectively. There was no significant difference in non‐return rate between the two groups (p > .05). But the litter size of 80 μM IM group was significantly higher than that of control group (p < .05). 80 μM IM inhibited proliferation of the phylum Proteobacteria and the genus Staphylococcus as well as Pseudomonas (p < .05). Further studies are required to understand the antibacterial mechanism of IM in liquid‐preserved boar semen. 相似文献
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YQ Lv S Ji X Chen D Xu XT Luo MM Cheng YY Zhang XL Qu Y Jin 《Reproduction in domestic animals》2020,55(8):1011-1020
Glycerol is used as a bovine semen osmotic cryoprotectant that greatly improves the quality of frozen and thawed bovine sperm. However, high glycerol concentrations can have a toxic effect on frozen and thawed bovine sperm. Therefore, this experiment investigated the effect of replacing a portion of the glycerol in a cryoprotectant solution with crocin on the sperm apoptosis, protamine deficiency and membrane lipid oxidation of frozen and thawed Yanbian yellow cattle sperm. The experiment included a control group (6% glycerol) and four treatment groups: I (3% glycerol), II (3% glycerol +0.5 mM crocin), III (3% glycerol + 1 mM crocin) and IV (3% glycerol + 2 mM crocin). Computer assisted semen analysis was used to detect sperm motility, Hoechst 33,342, propidium iodide, and JC-1 staining were used to analyse sperm viability and mitochondrial membrane potential, chromomycin A3 staining was used to detect protamine deficiency and DNA damage, flow cytometry was used for sperm membrane lipid disorder detection and analysis, and real-time quantitative RT-qPCR was used to detect the mRNA expression levels of protamine-related genes (PRM2, PRM3), sperm acrosome-associated genes (SPACA3), oxidative stress-related genes (ROMO1) and apoptosis-related genes (BCL2, BAX). Compared to the control group, replacing a portion of glycerol with 1 mM crocin significantly improved sperm motility, plasma membrane integrity, membrane lipid disorders (p < .05) and viability, mitochondrial membrane potential, protamine deficiency (p < .01). The expression level of PRM2, PRM3, SPACA3 and BCL2 significantly increased (p < .05), while the expression levels of ROMO1 and BAX significantly decreased (p < .05). Accordingly, the BCL2/BAX ratio significantly increased (p < .05). In summary, the substitution of a portion of glycerol with crocin in cryoprotective solution improved the quality of Yanbian yellow cattle sperm after freezing and thawing. 相似文献
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In this paper,questionnaires about college tea culture and humanism spirit have been investigated in the undergraduates of Hebei Agricultural University in mountainous area of Northern China.After analyzing the survey results and the causes,the author made references and gave recommendations to the university students about the tea culture and humanism spirit cultivation. 相似文献
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