功能性寡糖对奶山羊瘤胃发酵功能的影响

为研究外源功能性寡糖对奶山羊瘤胃发酵功能的影响,试验选用6只体重( 32.80±2.45) kg装有永久性瘤胃瘘管的崂山奶山羊,采用分期分组试验设计,对照组不添加寡糖,试验组分别饲喂添加1％甘露寡糖、半乳甘露寡糖、果寡糖、寡木糖和异麦芽寡糖的试验饲粮.试验共分为4期,每期15 d,其中预试期13 d,正试期2d.结果表...     

An activated mutant of SHP-2 tyrosine phosphatase causes murine myeloid abnormal proliferation

AIM: To investigate whether an activated mutant of SHP-2 tyrosine phosphatase is involved in abnormal proliferation of murine myeloid.METHODS: Wild-type (WT) and SHP-2^D61G/+mutant mice aged 8 weeks and 16 weeks were used. The number of peripheral blood leukocytes and the spleen sizes were measured by cell counting and weighing methods,respectively. The surface markers (Mac-1 and Gr-1 for myeloid, Ter119 for erythroid, CD3 for T-lymphocyte and B220 for B-lymphocyte) of hematopoitic cells in peripheral blood and bone marrow were detected by flow cytometry. The rate of Mac-1 or Gr-1 positive cells in the peripheral blood and the rate of Mac-1, Gr-1, Ter119, CD3 or B220 positive cells in bone marrow were analyzed. The ability of colony formation unit (CFU) of the bone marrow was also observed by CFU assay. Finally, the expression of p-Akt and p-ERK in the peripheral blood leukocytes induced by interleukin-3 (IL-3, 5 μg/L) was detected by Western blotting.RESULTS: The number of leukocytes in peripheral blood of 16-week-old mice was more (P<0.01) and the spleens were bigger in mutant SHP-2^D61G/+ mice than those in WT mice. The rate of Mac-1 and Gr-1 positive cells in peripheral blood leukocytes of 16-week-old SHP-2^D61G/+ mice were dramatically increased (P<0.05). Mac-1 and Gr-1 positive cell rates in bone marrow of SHP-2^{D61G / +} mice were much higher (P<0.05) than those in WT mice and no statistic significance was found in the erythroid or lymphocyte cells. The number of CFU-GM (represents myeloid) was increased in mutant mice. The expression of p-Akt and p-ERK in peripheral blood leukocytes of mutant mice was significantly enhanced after stimulated with IL-3.CONCLUSION: These results suggest that activated mutant SHP-2 results in the disorder of mouse myeloid proliferation via MAPK and PI3K activation.     

桔梗新品种‘中梗白花1号’和‘中梗粉花1号’

 桔梗新品种‘中梗白花1号’和‘中梗粉花1号’是利用来自大田生产的桔梗白花和粉花材料,采用系统选育方法,历经4代自交纯化育成,均为晚熟品种,花期长,适于药用和观赏栽培。‘中梗白花1号’侧根多,根部药材产量高,桔梗皂苷含量高,抗立枯病。‘中梗粉花1号’植株直立,侧根少,根部药材产量和桔梗皂苷含量均较高,抗立枯病。     

Effects of exogenous paclobutrazol and sampling time on the efficiency of in vitro embryo rescue in the breeding of new seedless grape varieties

Embryo rescue technology plays an important role in seedless grape breeding. However, the efficiency of embryo rescue,including the embryo formation, germination, and seedling rates, is closely related to the parental genotypes, degree of abortion, growth medium, and plant growth regulators. In this study, we investigated the effects of different concentrations of paclobutrazol(PAC), a plant growth regulator, and embryo collection times on the embryo formation, germination, and seedling rates fo...     

新疆褐牛体重与体尺指标的相关及回归分析

为探讨新疆褐牛体重与体尺指标间的相关性及构建不同生长阶段的回归方程,为新疆褐牛选育提供直接而有效的方法,以伊犁地区2011—2019年6月龄、12月龄、18月龄、24月龄新疆褐牛为对象,测定4个生长阶段的4个体尺指标和体重并进行相关性分析和逐步线性回归分析.新疆褐牛不同生长阶段体重和体尺指标间存在着极显著的(P<0.0...     

冠毒素高产菌株的半推理选育

根据菌株利用萘为碳源与冠毒素生物合成的调控均受低温影响的特点,以及菌株对红霉素耐药机制受细胞膜孔蛋白和外排泵影响的特性,分别以菌株对萘代谢的温度敏感性及对红霉素抗性为筛选标志,依次采用亚硝基胍、5-溴尿嘧啶、紫外线、吖啶橙与紫外线混合等诱变方式,经系列推理选育,获得产冠毒素能力为100 μg/mL的突变菌株Y57,比野生菌株BCC933产量提高7.3倍.     

长江中下游地区耕地土壤有机碳密度变化率驱动因素

为探究长江中下游地区耕地土壤固碳增汇措施,该研究收集与整理长江中下游地区59处长期定位试验观测数据,量化不同类型耕地土壤有机碳密度变化率的差异特征,运用随机森林模型与线性规划探究土壤有机碳密度变化率的驱动因素与提升途径。结果表明：水田和旱地土壤有机碳密度变化率范围分别为−1 548.15～3 577.10 kg/(hm²·a)和-261.89～3 245.01 kg/(hm²·a),差异不显著（P=0.85）。有机肥氮量、土壤pH值、化肥氮量、秸秆氮量对水田土壤有机碳密度变化率的影响较大;有机肥氮量和化肥氮量对旱地影响较大。因此,建议长江中下游地区可通过有机无机肥科学配施,合理调控水田土壤pH值和秸秆还田量。该研究可为长江中下游地区耕地固碳增汇的技术推广提供参考。     

醋酸丙酸纤维素的合成及结构研究

采用非均相催化酯化法合成了醋酸丙酸纤维素(CAP),对合成的CAP的13 CNMR图谱进行了分析,分别得出了CAP的乙酰基和丙酰基的取代度,并与化学滴定方法进行了对比.采用IR、凝胶渗透色谱(GPC)、X射线衍射和差示扫描量热法(DSC)等检测手段对产物的结构和性能进行了表征.结果表明,与纤维素相比,所合成的CAP的晶型发生了明显的变化,结晶度从68%降到了30% ~40%,玻璃化转变温度为150 ℃左右.纤维素的酯化使其具有改善的塑化性能.     

松岭林业局森林资源消长变化及经营建议

文章通过对松岭林业局2007年森林资源二类调查数据的分析,详细阐述了森林资源现状、森林资源消长变化情况及今后对森林经营管理的建议。     

植物甜蛋白Miraculin的特性及其应用

植物甜蛋白是一类高甜度低热量的天然甜味剂。概述开发甜蛋白的研究进展及其生产方式,并着重介绍甜蛋白Miraculin的基本性质、物质组成、提取分离纯化方法及应用前景。