荒漠草原人工柠条对冠下蒙古冰草种子萌发和幼苗生长的影响

本研究以盐池县荒漠草原人工柠条林（Caragana intermedia）为研究对象,将蒙古冰草（Agropyron mongolicum）种子分别播于柠条冠下两侧（东侧SE,西侧SW）及带间（CK）,通过定期观测微气候及蒙古冰草的种子萌发和幼苗生长,探讨人工柠条林对冠下微气候、蒙古冰草种子萌发和幼苗生长的影响。结果表明：SW和SE的土壤温度分别为18.57℃和18.51℃,显著低于CK（P<0.05）,空气相对湿度分别为40.73%和34.51%,高于CK;不同微生境条件下蒙古冰草幼苗数均在播种后60 d达到最高,自出苗开始至结束,SW和SE的幼苗数均显著高于CK（P<0.05）,总出苗率分别较CK增加了18.97%和20.00%,存活率分别较CK增加了24.04%和17.34%;自播种后45 d起SW和SE的苗高均显著高于CK（P<0.05）,至90 d时SW和SE的苗高分别达10.19 cm和10.01 cm;冗余分析表明空气相对湿度和土壤有机碳是影响蒙古冰草种子萌发和幼苗生长的主要因子。综上所述,柠条灌丛对蒙古冰草种子萌发和幼苗生长具有一定的保育作用。     

不同浓度的萘乙酸处理对苜蓿无性繁殖影响初探

为提高苜蓿单一性状,加速苜蓿的良种繁殖,针对苜蓿在高寒高海拔地区种植难、返青缓慢的特点,用不同浓度的萘乙酸处理苜蓿插条,进行了无性繁殖的探索和研究.试验结果表明萘乙酸处理苜蓿插条的最适浓度是4 g萘乙酸/5 kg水,其苜蓿插条成活率达到81.7%,返青率达86.7%.     

Self-assembly of ordered microporous materials from rod-coil block copolymers

Rod-coil diblock copolymers in a selective solvent for the coil-like polymer self-organize into hollow spherical micelles having diameters of a few micrometers. Long-range, close-packed self-ordering of the micelles produced highly iridescent periodic microporous materials. Solution-cast micellar films consisted of multilayers of hexagonally ordered arrays of spherical holes whose diameter, periodicity, and wall thickness depended on copolymer molecular weight and composition. Addition of fullerenes into the copolymer solutions also regulated the microstructure and optical properties of the microporous films. These results demonstrate the potential of hierarchical self-assembly of macromolecular components for engineering complex two- and three-dimensional periodic and functional mesostructures.     

免疫抑制剂环磷酰胺对肉仔鸡生产性能及其内分泌的影响

本研究观察了免疫抑制剂环磷酰胺对肉仔鸡生产性能及其内分泌的影响,旨在探讨免疫抑制状态下肉仔鸡营养代谢的变化特点。120只20 d体重相近的健康AA雄性肉仔鸡随机分为2组：生理盐水组和环磷酰胺组,分别一次性腹腔注射等体积的生理盐水和环磷酰胺（10 mg/kg BW）。每日记录采食量和收集全部粪样,分组后第1、3、5、8、13天随机从每组取4只鸡,称重、心脏无菌采血后处死,迅速摘取脾脏、法式囊及左侧胸腺,剔除脂肪后称重,然后立即置于液氮保存。实验室进行饲料表观代谢能、粗脂肪和粗蛋白表观消化率、T、B淋巴细胞增殖能力、血清糖皮质激素（GC）、胰岛素（insulin）和甲状腺激素（T3和T4）水平及脾脏、法式囊和胸腺中IL-1βI、L-2和IFN-γmRNA含量的测定。结果：处理后第1天环磷酰胺组,（1）肉仔鸡法式囊指数、B细胞增殖能力、法氏囊中IL-1βmRNA和脾脏、法式囊中IFN-γ mRNA的含量显著降低（P〈0.05）。（2）肉仔鸡体重显著增加（P〈0.05）,肉仔鸡采食量、粗脂肪和粗蛋白表观消化率显著降低（P〈0.05）。（3）血清GC水平极显著降低（P〈0.01）,血清insulin水平显著升高（P〈0.05）。（4）除处理后第3天环磷酰胺组体重仍显著升高（P〈0.05）外,其它时间各项指标都没有显著变化（P〉0.05）。这些结果表明,环磷酰胺诱发了肉仔鸡的免疫抑制,在这种免疫抑制状态下肉仔鸡生产性能得到了提高,糖皮质激素分泌降低而胰岛素分泌升高。     

不同浓度的萘乙酸处理对苜蓿无性繁殖影响初探

为提高苜蓿单一性状,加速苜蓿的良种繁殖,针对苜蓿在高寒高海拔地区种植难、返青缓慢的特点, 用不同浓度的萘乙酸处理苜蓿插条,进行了无性繁殖的探索和研究。试验结果表明:萘乙酸处理苜蓿插条的最适浓度是4 g萘乙酸/5kg水,其苜蓿插条成活率达到81．7％,返青率达86．7％。     

小麦微效基因和修饰基因的选择理论与实践

本文作者在实践中发现小麦多基因性状后期选择的重要性，并从遗传学理论上论述了微效基因、修饰基因后期选择的有效性、可遗传性。在实践与理论相印证的基础上，提出了小麦育种在新品种参加生产试验时或审定时（一般世代为F11～F13代）进行三圃提纯选择是十分必要的，不仅可改善新品种品质，而且还可以起到传统的提纯复壮作用，提高产量，增强抗逆性，发挥新品种的利用价值，延长品种的使用寿命，对当今生产实践具有重要指导意义。     

Syncope associated with swallowing in two British Bulldogs with unilateral carotid body tumours

Carotid body tumours were diagnosed in two British Bulldogs that each had a history of syncopal episodes induced by eating, drinking or pulling on the leash. In both dogs, a cervical mass was identified using computed tomography (CT) or magnetic resonance imaging, with carotid body tumour (CBT) being the histopathological diagnosis. A heart base mass was also identified in one dog by both CT and echocardiography. Swallowing syncope has been reported in the human literature in association with cervical mass lesions, but this is the first report in dogs. The present cases emphasise the value of advanced imaging of the head and neck in dogs presenting with clinical signs of syncope associated with swallowing and the importance of careful manipulation of the neck in patients with CBTs.     

Pre‐ and Post‐Partum Mild Underfeeding Influences Gene Expression in the Reproductive Tract of Cyclic Dairy Cows

Undernutrition before and after calving has a detrimental effect on the fertility of dairy cows. The effect of nutritional stress was previously reported to influence gene expression in key tissues for metabolic health and reproduction such as the liver and the genital tract early after calving, but not at breeding, that is, between 70 and 90 days post‐partum. This study investigated the effects of pre‐ and post‐partum mild underfeeding on global gene expression in the oviduct, endometrium and corpus luteum of eight multiparous Holstein cows during the early and middle phases of an induced cycle 80 days post‐partum. Four control cows received 100% of energy and protein requirements during the dry period and after calving, while four underfed received 80% of control diet. Oestrous synchronization treatment was used to induce ovulation on D80 post‐partum. Oviducts, ovaries and the anterior part of each uterine horn were recovered surgically 4, 8, 12 and 15 days after ovulation. Corpora lutea were dissected from the ovaries, and the endometrium was separated from the stroma and myometrium in each uterine horn. The oviduct segments were comprised of ampulla and isthmus. RNAs from ipsi‐ and contralateral samples were pooled on an equal weight basis. In each tissue, gene expression was assessed on a custom bovine 10K array. No differentially expressed gene (DEG) in the corpus luteum was identified between underfed and control, conversely to 293 DEGs in the oviduct vs 1 in the endometrium under a false discovery rate (FDR) < 0.10 and 1370 DEGs vs 3, respectively, under FDR < 0.15. Additionally, we used dedicated statistics (regularized canonical correlation analysis) to correlate the post‐partum patterns of six plasma metabolites and hormones related to energy metabolism measured weekly between calving and D80 with gene expression. High correlations were observed between post‐partum patterns of IGF‐1, insulin, β‐hydroxybutyrate and the expression in the oviduct of genes related to reproductive system disease, connective tissue disorders and metabolic disease. Moreover, we found special interest in the literature to retinoic acid‐related genes (e.g. FABP5/CRABP2) that might indicate abnormalities in post‐partum tissue repair mechanisms. In conclusion, this experiment highlights relationships between underfeeding and gene expression in the oviduct and endometrium after ovulation in cyclic Holstein cows. This might help to explain the effect of mild undernutrition on fertilization failure and early embryonic mortality in post‐partum dairy cows.