白肉灵芝水提物对脑缺血大鼠海马神经元的保护作用

试验旨在探讨白肉灵芝水提物（Ganoderma leucocontextum aqueous extracts,GLAE）对脑缺血后海马神经元的保护作用及机制。将50只健康大鼠分为对照组、模型组、GLAE低（0.05 mg/（g·BW））、中（0.1 mg/（g·BW））、高（0.2 mg/（g·BW））剂量组。利用双侧颈总动脉夹闭法建立大鼠脑缺血模型,GLAE组灌胃不同剂量的GLAE干预,对照组和模型组灌胃同体积的生理盐水,连续2周。用跳台试验方法检测记忆获得、记忆巩固和记忆再现障碍大鼠的学习记忆能力,HE染色观察大鼠海马组织的病理形态的变化,比色法检测海马组织一氧化氮合酶（nitric oxide synthase,NOS）活性和一氧化氮（nitric oxide,NO）含量,Western blotting和实时荧光定量PCR法分别检测海马组织生长相关蛋白-43（growth associated protein-43,GAP-43）和脑源性神经生长因子（brain derived neurotrophic factor,BDNF）的水平。结果显示,与对照组相比,模型组大鼠跳台试验的逃避潜伏期显著缩短、电击次数显著增加（P<0.05）;海马神经元细胞出现明显核固缩、排列松散紊乱等退行性改变,细胞数量显著减少（P<0.05）;海马组织NOS活性和NO含量均显著降低（P<0.05）;大鼠海马组织GAP-43蛋白表达量显著升高（P<0.05）;海马组织BDNF mRNA表达量显著下调（P<0.05）。与模型组相比,GLAE干预后,大鼠逃避潜伏期均显著延长、电击次数均显著减少（P<0.05）;GLAE高剂量组大鼠CA1区和齿状回锥体神经元细胞形态明显改善,神经元数量显著增加（P<0.05）;GLAE低剂量组对NOS活性影响不明显（P>0.05）,显著增加NO含量（P<0.05）,GLAE中、高剂量组NOS活性和NO含量均显著升高（P<0.05）;GLAE低、中、高剂量组海马组织GAP-43蛋白表达量均显著增加（P<0.05）;GLAE低、中、高剂量组海马组织BDNF mRNA表达量均显著增加（P<0.05）。以上结果表明,GLAE可通过提高NOS活性和NO水平、促进海马神经发生和功能恢复对脑缺血后海马神经元损伤有一定的保护作用,从而改善大鼠认知功能,0.2 mg/g GLAE效果最好。     

断奶仔猪日粮高剂量氧化锌的替代技术研究进展

氧化锌是断奶仔猪阶段饲料中防止腹泻的常用饲料添加剂,但是它的使用会造成环境污染。农业农村部也逐渐开始对氧化锌在养猪生产中的使用加以限制。此次研究从氧化锌的抗腹泻机理、不同的锌源和改变氧化锌的生物活性、氧化锌来源、植物乳杆菌、植物精油、水解单宁(HT)和氧化锌联合使用、猪免疫球蛋白G(pplgG)等方面进行综述,探讨其替代思路,以期为断奶仔猪高剂量氧化锌替代提供参考。     

NO/ADMA在布鲁菌侵染小鼠机体过程中的响应特征

本试验旨在研究布鲁菌侵染小鼠过程中一氧化氮(NO)的作用,以及NO和非对称性二甲基精氨酸(ADMA)在此过程的相互作用关系。以布鲁菌标准疫苗株M5侵染小鼠,首先用小鼠的血清进行虎红平板凝集(RBPT)和试管凝集试验(SAT),再用Griess试剂法和ELISA法测定对照组和侵染组不同组织和血清中的NO和ADMA含量,对小鼠肝脏和脾脏的各个侵染时间段进行CFU计数观察。结果显示,用布鲁菌M5侵染小鼠后,RBPT和SAT在14d时检测到有阳性反应。侵染组和空白对照组NO总含量上变化不大,但侵染组血清中的NO含量随时间出现下降,而肝脾中NO含量随时间出现上升,其他各组织NO含量波动不明显。而ADMA的总趋势与NO相反。CFU计数结果显示,小鼠肝脾内布鲁菌的数量在14d时一直处于增长状态,28d时布鲁菌的数量下降,表明布鲁菌的分裂繁殖和机体NO的含量存在一定的关系。     

Comparison of emission estimates for non‐CO2 greenhouse gases from livestock and poultry in Korea from 1990 to 2010

It has often been claimed that non‐carbon dioxide greenhouse gases (NCGGs), such as methane, nitrous oxide and fluorinated greenhouse gases, are significant contributors to climate change. Here we nvestigate emission estimates of methane and nitrous oxide from livestock and poultry production, which is recognized as a major source of those NCGGs, in Korea over the period of 1990 through 2010. Based on the data on livestock and poultry populations, emission estimates of methane and nitrous oxide are first derived based on the Tier 1 approach. Then, the Tier 2 approach is adopted to obtain emission estimates of methane and nitrous oxide from cattle, which are known to be the largest sources of these NCGGs and account for about 70% of emissions from livestock and poultry in Korea. The result indicates that the Tier 2 estimates of methane and nitrous oxide emissions from enteric fermentation and manure management are significantly different from the Tier 1 estimates over the analysis period.     

Endometrial nitric oxide production and nitric oxide synthases in the equine endometrium: Relationship with microvascular density during the estrous cycle

Nitric oxide (NO) plays an important role in angiogenesis and in the regulation of the blood flow. This study was carried out to investigate (i) the effects of endogenous estrogens and progestins and exogenous progesterone (P₄) (5 ng/ml or 1 μg/ml) or estradiol 17β (E₂β) (50 pg/ml or 1 μg/ml) on in vitro endometrial NO synthesis; (ii) the presence of different isoforms of NO synthase; (iii) and their relationship to microvascular density in the equine endometrium during the estrous cycle. NOS expression was also evaluated in the myometrium. Expression of endothelial and inducible forms of NOS in the uterus was assessed by Western blot and immunocytochemistry. Vascular density in endometrial tissue was determined on histologic sections. In the luteal phase, compared to the follicular phase, endometrial NO production increased without exogenous hormones and with exogenous E₂β (1 μg/ml). Although immunocytochemistry revealed iNOS and eNOS expression in the endometrium, no positive signal for iNOS was detected by Western blot. Endothelial NOS was observed in endometrial glands, endothelial cells, fibroblasts, blood and lymphatic vessels. Endometrial eNOS expression was the highest in the follicular and mid-luteal phases while it was found to be the lowest in the early luteal phase. In the follicular phase, hyperplasia of endometrial tissue with respect to myometrium was detected. No difference in vascular density was present between phases. All together, NO may play some roles in both proliferative and secretory phases of endometrial development in the mare.     

中国草地固碳减排研究现状及其建议

随着经济的快速发展,温室气体的排放量不断增加,加之人类对自然资源的利用强度逐渐增加,导致全球生态系统的固碳能力减弱,大气中的温室气体浓度达到新高,所造成的温室效应已经成为国际社会普遍关注的重大全球性问题。中国草地碳汇资源得天独厚,发展草原碳汇经济成为履行国际承诺、打造碳汇新经济、建设美丽中国的重要载体。综述中国草地固碳减排现状及其影响因素,包括草地碳汇和家畜生产减排研究、气候变化背景下的草地碳汇、人工草地建设等方面,并提出中国草地固碳减排发展建议,以期为中国实现碳达峰、碳中和及草地固碳减排的贡献提供理论基础,为推动我国社会高质量发展、创造高品质生活提供坚实的技术支撑。     

施肥对不同品种麦田CO2通量的影响

为探讨施肥对小麦田间CO2释放量的影响,本研究设计以4个不同施肥水平为主处理,以3个不同年代的主栽品种碧玛1号、烟农15号、山农11号为研究对象,采用封闭式静态暗箱技术,应用LI-6400型便携式光合仪(美国)在作物生长期测定土壤CO2释放量和光合速率。同时测定了环境影响因素土壤温度和水分等。研究结果表明,施肥有利于增加土壤CO2释放量,且中氮处理水平释放量最多;土壤温度和水分对土壤CO2释放量有一定的影响,土温越高,水分越大,CO2释放越多;麦田CO2交换量与小麦根系活性呈正相关。     

Density Functional Theory Compute on Electronegativities to Superconductivity of Oxides

In this article we have worked out the correlation between electronegativity and high temperature superconductivity for oxide. It is suggested the equalized electronegativity, X cq , can be used as a empirical criterion for superconductivities of oxides. For determining the X cq , a new formula for the calculation of X cq values has been obtained The X cq values of 230 oxide superconductors have been calculated. The result shows that the X cq values of all the oxide superconductors concentrate in a narrow range from 5.00 to 5.63 and that the oxides with values out side this region would be non-superconductive. This criterion can be applied to almost all the oxide superconductors. It is clearly that this result is able to benefit further inquiries about the mechanism of superconductivity.