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The cervical patency of six domestic female cats was monitored under sedation by infusion of contrast medium (Omnipaque) into the cranial vagina during early oestrus, mid‐oestrus, late oestrus and interoestrus or a radiopharmaceutical (99mTc‐HSA) during mid‐ and interoestrus in a non‐ovulatory oestrous cycle. The transport of the contrast medium or the radiopharmaceutical through the cervix and within the uterine horns was observed under fluoroscopy and with the aid of scintigraphy. In three of the queens, transcervical transport of contrast medium was demonstrated in all stages of oestrus, in one queen during mid‐oestrus, late oestrus and 1 day after oestrus, and in two queens only during late oestrus. The relations between the cervical patency to the contrast medium and the oestrous behaviour, cornification of the vaginal cells and the serum oestradiol‐17β concentration were evaluated, and a relationship was found between the cervical patency and the degree of vaginal cornification. Transcervical transport of the radiopharmaceutical was observed in three queens during mid‐oestrus. When the cervix was open, hysterography under a fluoroscope and hysteroscintigraphy were performed. The fluoroscopic and scintigraphic recordings revealed the patterns of the uterine contractions during oestrus in both ascending and descending directions, and the movement of the uterine contents back and forth between the uterine horns. The hysterograms were classified according to the shape of the uterine horns and the appearance of the endometrial lining. Spiral‐shaped uterine horns with a smooth inner contour were observed in two queens, and a corkscrew appearance with irregular filling defects in the uterine lumen was shown in two queens that had developed subclinical cystic endometrial hyperplasia. These findings demonstrated that fluids or particles deposited in the cranial vagina of the cat can be transported into the uterus during some stages of the oestrous cycle. The fluoroscopic and scintigraphic techniques developed in this study may be further modified to permit more detailed studies of uterine contractile patterns and sperm transport in the feline female reproductive tract. Hysterography proved useful to diagnose uterine disease. The information on cervical patency is of value also for the development of techniques for artificial insemination in this species, and should be studied also in the ovulatory cycle. 相似文献
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Abstract – The different reproductive roles of the sexes can predict the direction and magnitude of sexual dimorphism of external and internal morphology. Males should have enlarged structures that enhance the acquisition of mating opportunities, whereas females are predicted to have enlarged organs that are associated with the production of eggs. We tested these predictions in male and female lake whitefish, a species in which both sexes have similar overall body size and shape. After controlling for body size, male lake whitefish had significantly longer jaws and pectoral and pelvic fins, larger hearts, and more muscle than females. Sexual dimorphism in relative muscle mass may be one of the most fundamental morphological differences between males and females. Females had relatively heavier livers than males. Because the liver is important for the breakdown of fats and vitellogenesis, selection should favour an enlarged liver in females for the processing of energy and the production of large numbers of eggs. 相似文献
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Growth and survival of three small abalone Haliotis diversicolor populations and their reciprocal crosses 总被引:1,自引:0,他引:1
The aquaculture industry of small abalone Haliotis diversicolor in southern China is now close to collapse because of high mortality at the grow-out stage. To examine if survival and growth (shell length increase) could be improved by cross breeding among populations, a 3 × 3 complete diallel cross was conducted among three populations from Japan (A), Taiwan (B) and Vietnam (C). Performances in growth rate and survival at early juvenile, later juvenile and grow-out stages were compared among the six reciprocal cross lines and three parental lines. Magnitude of heterosis for survival and growth varied among cross lines in the three growing stages. As to mid-parent heterosis, H AB was significantly ( P <0.01) higher than H AC and H BC at all three growing stages for both growth and survival, and all mid-parent heterosis fell between the two corresponding single-parent heterosis. H AB was 6.84% for shell length and 69.09% for survival at Day 420. Our results of high survival heterosis in line AB and line BA show that crossbreeding between different populations can benefit the small abalone breeding programs and the industry. 相似文献
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在气体碳氮共渗渗剂中,添加微量稀土元素对5CrMnMo钢的组织和性能有显著的影响。试验结果表明,由于稀土元素具较低的电负性和高的化学活性,三元共渗可强化模具表面,使表层获得大量的合金碳化物,基体组织也由针状马氏体变为以扳条马氏体为的混合马氏体,模具有硬度及热强性都得到提高,延长了模具的使用寿命1-2倍。 相似文献
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培养创新人才是不同发展阶段、不同形态社会对教育的基本诉求。通过对我国部属农林高校创新创业教育改革实施方案文本分析可知,在开展创新创业教育改革发展目标方面高度认同,在组织机构设置方面高度重视,在选择举措方面高度完备。同时存在目标定位无特色又高度雷同,相关部门间协同育人机制缺失以及对发力点缺乏明晰的判断等问题。推进范式转换,设置创新创业教育专业、建立创新创业教育监督执行机构成为当下破解创新创业教育改革困境的重要选择。 相似文献
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采用廉价的硫酸盐皂作为乳化剂的原料,以石蜡作为防水材料,经预处理,加热,调pH,分散和冷却等过程,研制出浅黄色膏状的ZL刨花板防水剂。经制板试验证明,该防水剂防水效果良好,施加方便,便于运输和贮存。 相似文献
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