D-101大孔树脂对香椿叶中黄酮类成分的分离纯化及抗氧化活性研究

为充分利用香椿老叶,用D-101大孔吸附树脂对香椿叶中黄酮类成分进行分离纯化。以黄酮类成分的吸附率、洗脱率及黄酮纯度为指标,研究D-101大孔树脂对香椿中黄酮类成分的吸附能力及其稳定性。同时用清除1,1-二苯基苦基苯肼(DPPH)自由基的能力对香椿叶中黄酮类成分的抗氧化能力进行评价。结果表明,D-101大孔树脂的最佳上样条件为香椿浸提液上样量5 BV,黄酮类成分浓度0.69 mg/mL,流速3 BV/h。最适洗脱条件为70%乙醇洗脱剂,洗脱剂用量5 BV,流速3 BV/h。树脂使用1次时,可将香椿中黄酮类成分的纯度由6.0%提升到45.14%,且树脂稳定性良好,可重复使用6次后再生。经大孔树脂分离纯化后的黄酮类成分具有很强的抗氧化能力,为抗坏血酸的1.33倍。     

4份圆锥小麦-乌拉尔图小麦双二倍体的分子细胞遗传学鉴定

为了给小麦育种提供新的种质资源,对4份圆锥小麦-乌拉尔图小麦双二倍体(AABBA^uA^u)的农艺性状、染色体组成及高分子量谷蛋白亚基组成进行了鉴定。农艺性状调查结果表明,4份双二倍体的株高介于108.45~129.43 cm,分蘖数介于7.3~17.5个,穗长介于10.23~12.17 cm,小穗数介于16.26~22.06,自交结实率介于37.77%~70.46%;4份双二倍体对目前的流行条锈菌混合生理小种(条中31、条中32、条中33、条中34和水源11-4)均表现为高抗。利用寡核苷酸序列探针Oligo-pSc119.2-1、Oligo-pTa535-1、Oligo-pTa71-2、pTa-713和简单重复序列探针(AAC)5进行FISH分析,可区分出圆锥小麦-乌拉尔图小麦双二倍体的42条染色体。花粉母细胞染色体配对观察表明,在这些双二倍体的减数分裂中期I,染色体大多配对成二价体,仅有少量的单价体、三价体和四价体。SDS-PAGE分析表明,来自于乌拉尔图小麦TA#831的1Ay亚基在双二倍体Syn-TAU-2中得到了表达,但其迁移率发生了变化;来自于PI428270和PI428274的1Ax和1Ay亚基分别在双二倍体Syn-TAU-3和Syn-TAU-4中得到了表达。这些双二倍体可作为新的资源材料用于普通小麦的遗传改良。     

三平移机构设计与运动学符号解及性能评价

根据基于方位特征(POC)方程的并联机构拓扑结构设计理论和方法,设计一种具有正向位置符号解且具有部分运动解耦性的新型三平移(3T)并联机构。首先,对其进行拓扑特性分析,得到方位特征集(POC)、自由度(DOF)、耦合度(κ)等主要拓扑特征值;其次,根据提出的基于拓扑特征的正向运动学建模原理,求出机构的正向位置符号解;根据推导的逆解公式,求解该机构的工作空间;基于旋量理论求解各支链传递力旋量与输出运动旋量,得到机构运动/力传递性能指标,并分析相关的奇异位型;最后,利用局部传递指标评价了机构距离奇异位型的远近。     

Chimeric Antigen receptor-T (CAR-T) cells targeting Epithelial cell adhesion molecule (EpCAM) can inhibit tumor growth in ovarian cancer mouse model

Ovarian cancer (OC) is one of the most lethal solid tumors with poor prognosis. In 2017, two chimeric antigen receptor-T (CAR-T) cell drugs were approved by the U.S. Food and Drug Administration (FDA), and continuously optimized CAR-T cells therapy might be the novel hope for OC patient. EpCAM are known to be over-expressed in OC cells and could be targeted by CAR-T cells. However, the feasibility of using EpCAM-CAR-T cells to treat OC still needs to be verified. We engineered the 3rd-generation EpCAM-CAR containing a single-chain variable fragment (scFv) EpCAM-scFv that targeting EpCAM, a CD8 transmembrane domain, the costimulatory domains from both CD28 and 4-1BB, and activating domain CD3ζ and then transduced the CAR into T-cells via lentivirus. In addition, the cytotoxicity and cytokine releasing ability of the EpCAM-CAR-T cells against OC cell SKOV3 were verified in vitro. The in vivo data also showed that EpCAM-CAR-T cells significantly reduced the tumor size in OC xenograft mouse models. The anti-tumor activity of EpCAM-CAR-T cells against OC in vitro and in vivo indicated that the CAR-T might provide a promising therapeutic approach to OC.     

牛肉加热过程中水分迁移规律研究

采用100℃隔水加热方式加热牛肉28 min,每隔7 min采集一次样品,利用LF-NMR技术初步探讨牛肉加热过程中水分迁移规律。结果表明:随着加热时间的延长,牛肉蒸煮损失呈现上升趋势,剪切力不断增大,核磁数据显示牛肉内部水分状态组成变化显著,T2弛豫时间逐渐变短,不易流动水T22占比逐渐减少,自由水T23占比逐渐增多,且随着加热时间的延长,不易流动水和自由水很难在T2弛豫谱上分开,峰宽变大趋势明显,核磁成像结果显示加热会降低牛肉内部的水分含量。相关性分析结果表明:T21与牛肉的蒸煮损失呈显著正相关,T22与牛肉的蒸煮损失、剪切力呈显著负相关,T22峰面积占比与T2b、牛肉的蒸煮损失、剪切力呈显著负相关。由此得出加热处理对牛肉内部的水分分布和质构特性产生显著影响,同时两者之间存在相关性。     

Barley response to salt stress at varied levels of phosphorus

Increasing plant phosphorus (P) supply can increase or decrease salt tolerance of many plants. Barley (Hordeum vulgare L., cv. ACSAD 176) was grown in nutrient solution under controlled conditions to determine effects of P level on detrimental effects of sodium chloride (NaCl). Increasing level of P improved tolerance of barley to NaCl. At 3, 30, and 60 μM P, the NaCl concentrations to reduce shoot dry matter (DM) by 50% were 158, 193, and 260 mM, respectively. Increased NaCl levels reduced shoot P concentrations. Plants grown with NaCl had higher Internal P requirements. When NaCl in solution was 10, 150, and 300 mM, the corresponding concentrations of P in shoots required to obtain 50% DM were 1.6, 4.2, and 4.7 mg‐g^‐1 dry weight, respectively. Increasing solution P level from 3 to 60 μM P decreased sodium (Na) and increased potassium (K) concentrations in shoots. Accumulation of mineral ions for osmotic adjustment and restriction of Na accumulation in shoots was involved in P enhancement of salt tolerance of barley.     

Poly-generation of cooling, heating and power performance analysis of PV radiant panel PV/T system

A combined cooling, heating and power mono-silicon solar photovoltaic radiant panel (PV/R) is proposed, which compounds the radiant panel with the PV module. The PV operating temperature is decreased through the internal cycling of liquid pipe of radiant panel. Thus the power efficiency of PV module is increased, at the same time, the heat of PV using for heating can be recollected. While at night, the cooling used for the daytime is collected through the nocturnal cooling storage. In the experiment testing, the PV/R not only increases the power efficiency by 8%~16%, but obtains the heating efficiency by 45% and gets the cooling capacity of 40~80 W/m 2.     

The application of various chemicals to cuts made in the stem bases of Brachystegia spiciformis Benth., Julbernardia globiflora (Benth.) Troupin and Terminalia sericea Burch. ex DC.

Picloram‐potassium and various mixtures of picloram with 2,4‐D amine, 2,4,5‐T ester or amine, or 2,4,5‐T ester alone were injected into incisions made in the cambium of standing Brachystegia spiciformis and Julbernardia globiflora trees. Each arboricide was tested at a range of application rates, at different times of the year and at three different sites for each species. Picloram‐potassium and 2,4,5‐T ester were also tested on Terminalia sericea trees. Glyphosate, MCPA, mixtures of mecoprop and 2,4,5‐T amine and different mixtures of 2,4‐D ester with 2,4,5‐T ester, cacodylic acid and Tandex were tested on B. spiciformis and J. globiflora trees at one site and only in January. Aboricides containing picloram, with or without the addition of 2,4‐D or 2,4,5‐T, were the most effective chemicals for the control of trees. Higher application rates were required to kill B. spiciformis and J. globiflora between May and October when they were not actively growing. T. sericea trees were susceptible to arboricide treatment throughout the year. The response of individual trees to treatment with arboricides appears to be related to size.     

Leucosidea sericea — control in southern Lesotho

Tebuthiuron chemical treatments were effective in controlling Leucosidea sericea shrubs upon rangelands of the Quthing sheep stud station in southern Lesotho. Cutting treatments were also effective but more labour intensive. Repeated applications of 2,4,5‐T and fire resulted in less mortality of the shrubs and lower vigour of Eragrostis chloromelas grass than Tebuthiuron treatments.     

Effects of Population Density of Bolboschoenus planiculmis on the Absorption and Accumulation of Cotton Nutrients

[Objective] The aim of this study is to clarify the competition of the absorption and accumulation of nutrients in cotton by the Bolboschoenus planiculmis (F. Schmidt) T. V. Egorova. [Method] In this experiment, the population densities of B. planiculmis were set at 0, 20, 40, 60, 80, 100 plant·m^－2. The contents of phosphorus, potassium, nitrate nitrogen, soluble sugar and soluble protein in cotton seedling stage, bud stage and flowering and boll stage were detected to study the effect of population density of B. planiculmis on the nutrient absorption and accumulation of cotton. [Result] At the cotton seedling stage, when the population density of B. planiculmis was 20 plants·m^－2, the soluble protein content of cotton leaves increased significiantly (P＜0.05) compared with the CK, but there was no significant difference in other indicators. However, the higher population density of B. planiculmis could reduce the soluble protein content of cotton leaves and increase the soluble sugar content of cotton leaves. At the cotton bud stage, when the population density of B. planiculmis was lower than 40 plants·m^－2, the phosphorus content in cotton leaves increased significantly. At the cotton boll stage, the population density of all B. planiculmis populations could reduce the content of potassium and soluble sugar in cotton leaves. When the population density of B. planiculmis was 20 plants·m^－2, no significant effects were found on cotton yield. But under other population densities, the cotton yield was significantly reduced. [Conclusion] When the population density of B. planiculmis was higher than 20 plants·m^－2, significant effects were found on the absorption and accumulation of cotton nutrients and cotton yield.