Comparison of 2 methods for establishing rat model of chronic osmotic diarrhea

AIM: To compare 2 different rat models of chronic osmotic diarrhea with the lactose enrichment and magnesium citrate methods. METHODS: The SD rats (n=31) were randomly divided into lactose enrichment diarrhea group (Lac group, 12 rats), magnesium citrate diarrhea group (Mg group, 12 rats) and normal control group (Con group, 7 rats). The rats in Lac group were fed with a lactose enrichment diet and freely drank water. The rats in Mg group were fed with a standard diet and drank magnesium citrate solution. The Con group was fed with a standard diet and normal water. The general conditions and the characteristics of stool were observed every day. The grip strength and motor activity of the rats were measured after diarrhea for 14 d. The trans-epithelial resistance of the colonic mucosa was detected by Ussing chamber. The pathological changes of villus height and villus surface area in the intestine were observed with hemato-xylin-eosin staining. RESULTS: The rats in both diarrhea groups displayed the clinical manifestations of slow increase in body weight, spare and dull hair, lacking in strength and physical inactivity. The grip strength and motor activity of the rats in both diarrhea groups decreased significantly compared with Con group. The diarrhea rate and diarrhea index of the rats in the 2 diarrhea groups were both significantly higher than those in Con group (P<0.05). Moreover, the diarrhea index in Lac group was significantly increased compared with Mg group. The thickness of intestinal mucosa in Lac group was thinner than that in Mg group at the same time. However, the damage of intestinal villi in Mg group was more serious than that in Lac group.CONCLUSION: Both methods of lactose enrichment-induced diarrhea and magnesium citrate-induced diarrhea meet the requirement of chronic osmotic diarrhea, but there are different advantages between the diarrhea models. Therefore, we should select the correct diarrhea model to meet different aims of the experiments.     

从生育行为看农村妇女的家庭地位——基于江西X村的研究

通过对农村妇女生育行为及其家庭地位的个案访谈，发现从农村妇女的生育行为，主要是生育孩子的数量和性别，已经无法准确判断她们的家庭地位。即生育行为与妇女的家庭地位之间的联系正在弱化甚至消失，取而代之的是包括妇女的性别意识、经济独立性、知识水平等多方面因素。因此，提高农村妇女家庭地位的途径也变得多样化，其中，增强农村女性自身素质显得尤为重要。     

滑动平均法和分形理论结合的稻瘟病发病特性研究

通过文献分析稻瘟病发生与气象有着密切的关系,利用滑动平均法将云南省凤庆县稻瘟病病情指数分解成趋势及气象波动病情指数,分析结果表明趋势病情指数总体呈下降趋势,而气象波动病情指数具有一定的混沌特性,并利用相空间延拓及G-P算法验证了气象波动具有一定混沌特性。     

四川大豆疫霉毒力鉴定及资源抗性分析

采用土壤诱捕和组织分离的方法,从四川省仁寿县和雅安市大豆根腐病发病田块采集的土壤中和病株上分离到4个大豆疫霉分离物RS1、RS2和YA1、YA2,用含有已知抗性基因的鉴别寄主进行毒力鉴定。结果表明YA1和YA2毒力公式相同,为1a,1b,1d,2,3c,属于同一致病型;RS1、RS2毒力公式分别为1a,1d,1k,3a,3c,4,5和1a,1b,1c,1d,1k,2,3c,5,分别为不同致病型。用3个致病型接种157份大豆资源,结果表明,抗病种质相对较少,占23.57%;地方品种抗病性较育成品种强,本研究可为大豆抗病性育种提供科学依据。     

国审稻新品种松辽838选育技术报告

为育成适宜北方稻区种植的高产稳产、丰产性好、抗逆性强、品质优良、适应性广等综合性状优异的中早粳早熟品种,促进北方稻区水稻生产的发展,开展此水稻遗传育种课题。叙述水稻新品种松辽838(松辽11-838)的选育过程及参加国家3 a试验的生育表现与试验结果,以期使广大农民更好地了解品种的综合性状和栽培技术,应用生产后,发挥更大的品种增产作用。     

关于生物类基础化学教学中应用“问题学习法”的探讨

本文通过课前、课堂、课后三个部分的问题设置,紧扣教学大纲,紧密联系中学化学和后续课程中相关知识,体现理论联系实际、学科前沿。引领学生"主动学习,积极思考",为后续课程学习起到积极的、有效的铺垫作用。     

湖北省茄子品种抗褐纹病鉴定

收集了目前湖北省市场上销售的34个茄子品种,采用室内离体茄果人工接种的方法,鉴定了这些品种对茄子褐纹病的抗性水平。结果显示:从34个茄子材料中鉴定出免疫品种8个,高抗品种4个,抗病品种2个,中抗品种2个,感病品种18个,说明湖北市场上推广种植的茄子品种50%以上为感褐纹病品种。     

栽培槽大小对日光温室架式栽培番茄生长发育、水肥利用和产量品质的影响

利用封闭式循环供液高架栽培系统,研究了栽培槽大小(横切面宽度×深度:20cm×10cm,20cm×15cm,20cm×20cm)和钵栽(直径12cm×高10cm,基质容积1L)对架式栽培番茄(3穗果摘心)生长发育、水肥利用及产量品质的影响。结果表明:与钵栽相比,槽栽促进番茄植株生长,增加产量,但开花和采收时间延迟,果实品质下降,水肥利用效率降低;随着栽培槽体积的增大,植株生长旺盛,干物质积累量增加,但水肥利用效率降低,果实品质下降,不同大小栽培槽处理间水分利用效率和单株产量差异不显著。综合产量、品质及水肥利用效率等指标,番茄架式栽培槽大小以20cm×10cm为宜。     

白木乌桕种子特性及幼苗生长规律

以白木乌桕为试材,通过测定白木乌桕果实及种子特性,探讨温水浸泡、赤霉素处理对种子萌发的影响,比较萌发过程中相关酶活性变化,分析苗期生长规律。结果表明:白木乌桕果实平均鲜重1.45g,平均千粒重为173.62g;变异系数为2.08%~10.87%,最大为种子高,果实变异系数小于种子;温水浸泡、赤霉素处理可提高种子含水量、淀粉酶活性,打破种子休眠促进萌发,赤霉素400~800mg/L处理发芽率较好,种子发芽率达75%以上;随播种深度的增加种子发芽率呈先升后降趋势,2~4cm为最佳播种深度;年苗期呈现双峰曲线,峰值出现在第110、150天,与苗期1年抽2次梢对应。通过选育大种子可实现油料的高产,子叶厚度为关键选育因子,并可通过养分措施实现营养物质在子叶的积累,温水浸泡、赤霉素处理可促进种子吸水及淀粉酶活性提高而打破休眠促进萌发,春梢、秋梢期加强肥水管理可促进苗期生长。     

河北保定地区苹果锈果类病毒分离物的序列分析

以采自河北保定的苹果锈果类病毒(apple skin scar viroid,ASSVd)样本为试材,采用用RT-PCR方法对样本中的ASSVd全基因组序列进行扩增,然后利用生物学软件MEGA 6.0对该分离物与已发表的其它分离物序列构建系统发育树,对系统进化关系进行分析。结果表明:ASSVd保定分离物基因组全长332nt,将序列提交到GenBank,登录号为KR264032。该分离物与已发表的其它13个来自不同寄主、不同国家的ASSVd分离物间进化关系极近,核苷酸相似性为92%~99%。与加拿大苹果上的X71599株系亲缘关系最近,相似性为99%,仅在第221位有一个碱基差异,与新疆梨上的JX861259株系亲缘关系最远。系统发育分析表明,不同地区的ASSVd分离物聚类没有规律性,说明ASSVd不存在地区专化性。新疆梨、桃、杏、苹果不在同一分支,说明ASSVd可能存在一定的寄主特异性。二级结构预测表明,该分离物的中央保守区与末端保守区与ASSVd其它序列相同。