玉米灰斑病菌生理分化的鉴别寄主体系

玉米灰斑病现已成为北方玉米产区的主要病害之一，但国内外关于玉米灰斑病菌Cercospora zeaemaydis Tehon ＆ Daniels致病力分化等方面的研究较少，尚未建立该病菌生理分化的鉴别寄主系统，无法明确我国是否存在玉米灰斑病菌致病性分化类群或生理小种及优势菌群和分布，限制了有针对性地进行品种合理布局和抗病育种工作，因此研究玉米灰斑病菌致病性分化鉴别寄主体系是一项重要的基础性工作。作者采用田间成株期鉴定技术，对不同的玉米灰斑病菌菌株进行致病力划分，研究其鉴别寄主体系。     

鸡胚外泌体miRNAs功能分析

旨在基于鸡胚外泌体及所含有的miRNAs解析其产生生理功效的活性物质基础及作用机制。本研究收集13胚龄惠阳胡须鸡胚蛋18枚（3组,每组6枚）,采用酶消化、蔗糖密度梯度和差速超速离心等方法分离鸡胚组织来源的外泌体,经透射电镜、纳米流式和标志蛋白流式检测等方法鉴定其特征。利用高通量测序方法研究外泌体样本中miRNAs表达谱,对各样本top 10且共表达的miRNAs进行靶基因预测与功能分析。结果表明,分别获得了3个浮力密度范围（S1：1.13 g·mL^-1、S2：1.21 g·mL^-1和S3：1.32 g·mL^-1）具有外泌体典型特征的胞外囊泡;与miRBase V21进行比对发现,S1、S2和S3样品中分别含有675、661和845个已知的miRNAs,这些miRNAs中有488个（52.6%）三者共有,包括了广泛参与细胞增殖、分化和免疫应答等过程的功能性miRNAs。TargetScan 7.2和miRDB预测得到3个样本中top 10且共表达的56个miRNAs的靶基因,获得的3 650个靶基因经DAVID分析,显著富集了24个与机体生长、发育、免疫等有关的生物学通路（P<0.05）,包括MAPK信号通路、mTOR信号通路、Notch信号通路、Wnt信号通路和GnRH信号通路等。本研究建立了鸡胚组织中有效分离外泌体的方法,发现鸡胚组织来源的外泌体miRNAs会影响机体生长发育和免疫调节有关的生物学通路。     

菜豆种质资源对枯萎病菌的抗性研究

对供试的21份菜豆种质资源材料的幼苗采用下胚轴双孔注射法进行接种菜豆枯萎病菌(Fusarium oxyxporum f.sp.phaseoli),接种7 d后调查下胚轴维管束发病情况,计算病情指数,其中感病材料2份;中抗枯萎病材料11份;抗枯萎病材料7份;高抗枯萎病材料1份.     

葡萄霜霉菌候选效应子RXLR5信号肽的鉴定

利用Getorf、SignalP 3.0、BLASTP等生物信息学软件和PERL语言从葡萄霜霉菌基因组中预测到一条编码RXLR-EER结构域的效应蛋白候选基因,将该基因编码的蛋白命名为RXLR5。将RXLR5信号肽SP5编码序列连接到pSUC2T7M13ORI载体并转化到酵母蔗糖酶缺陷菌株YTK12后,重组菌株能成功分泌蔗糖酶,促使棉籽糖分解成单糖,因此,能在YPRAA培养基上正常生长;同时生成的单糖能与TTC反应产生红色不溶于水的氯化三苯基四氮唑。由此推测,SP5具有信号肽活性,可能在RXLR5从葡萄霜霉菌细胞内泌到胞外的过程中起重要作用。     

调亏灌溉和氮处理对小桐子生长及水分利用的影响

为了研究阶段水分亏缺(亏水+不亏水W_LW_H、不亏水+亏水W_HW_L、亏水+亏水W_LW_L、不亏水+不亏水W_HW_H)和不同施氮量(N_Z:0,N_L:0.2 g/kg,N_H:0.4 g/kg)对小桐子生长、生理指标和灌溉水利用效率的影响,通过盆栽试验,发现W_LW_H的生长和灌溉水利用效率均显著高于W_HW_L;作物的灌溉水利用效率随施氮量的增大而呈现先增大后减小的趋势,在N_L水平下达到最大值;与高水高氮的处理N_HW_HW_H相比,中水低氮处理N_LW_LW_H节约灌溉水27%,节约氮肥使用量50%,小桐子株高减少31%、总干物质量减少35%,灌溉水利用效率减少13%,但茎粗增加13%,根冠比增加20%.可见小桐子在第一阶段处理(40~90 d)幼树期对水分的需求量较小,适度的亏缺灌溉可提高灌溉水利用效率;小桐子在第二阶段处理(90~140 d)处于旺长期,对水分的需求量较大,增大灌水量可大幅度促进小桐子生长及其干物质量的积累.全生育期实施亏缺灌溉,可提高小桐子自身适应外界环境能力,抗干旱胁迫能力也逐渐增强,但W_LW_L水平下的小桐子生长缓慢.经综合分析,认为处理N_LW_LW_H可作为干旱地区条件下的小桐子灌溉和施氮制度.     

华南虎皮肤成纤维细胞的分离培养

应用酶消化法（胶原酶消化：0.1%胶原酶Ⅰ型＋0.1%BSA;胰蛋白酶消化：0.25%胰蛋白酶＋1mM EDTA）和植块法从华南虎皮肤组织中分离成纤维细胞。研究结果表明,植块法较适合分离华南虎皮肤成纤维细胞,胶原酶消化法次之,而胰蛋白酶消化法不宜用于分离华南虎皮肤成纤维细胞。DMEM/F12（1：1）培养基＋10%FCS＋10 ng/ml EGF＋5μg/ml胰岛素＋100 IU/ml青霉素＋100μg/ml链霉素组成的培养体系适用于华南虎皮肤成纤维细胞的体外培养。     

Association of tumor budding with tumor-infiltrating lymphocytes and prognosis in breast cancer patients

AIM: To investigate the relationship of tumor budding with clinicopathologic parameters, tumor-infiltrating lymphocytes (TILs) of tumor microenvironment and the prognosis in breast cancer patients.METHODS: A total of 178 HE section samples were collected from the breast cancer patients treated with surgery in the First Affilated Hospital of Jinan University during Jan. 2012 to Dec. 2016. The tumor budding and stromal tumor-infiltrating lymphocytes were observed under light microscope. The correlation of tumor budding with the clinicopathologic status and TILs were analyzed by χ² test. Kaplan-Meier survival analysis and Log-rank test were used to estimate the disease-free survival (DFS) and overall survival (OS).RESULTS: High tumor budding level was associated with more positive lymph nodes, higher grade, and more lymphovascular invasion. In addition, the patients with higher tumor budding level showed fewer TILs, while the patients with lower tumor budding level had more TILs. Furthermore, the patients with higher tumor budding level had a worse disease-free survival and overall survival than those with lower tumor budding level.CONCLUSION: Tumor budding is significantly associated with adverse clinicopathological characteristics of breast cancer and negatively correlated with TILs. Therefore, tumor budding may serve as a potential biomarker to predict the prognosis of breast cancer.     

Screening of cold-resistant seedlings of a Chinese wild grape (Vitis piasezkii Maxim var. pagnucii) native to loess plateau of eastern Gansu province,China, as rootstocks

Seedlings of a Chinese wild grape (Vitis piasezkii Maxim var. pagnucii) native to loess plateau of Eastern Gansu province, China, were evaluated to screen cold-resistant rootstocks in Lanzhou area. After 14-year investigation two selections of LDP-191and LDP-294 were screened as rootstocks for two table grape cultivars, ‘Fujiminori’ and ‘Red Globe’, respectively. The two graft unions demonstrated very high cold-resistance as well as good graft compatibility. Furthermore, they could survive through low temperatures in winter without soil coverage together with good fruit quality of the cultivars grafted.     

Pharmacokinetics of cefquinome in tilapia (Oreochromis niloticus) after a single intramuscular or intraperitoneal administration

The pharmacokinetics of cefquinome was studied in plasma after a single dose (10 mg/kg) of intramuscular (i.m.) or intraperitoneal (i.p.) administration to tilapia (Oreochromis niloticus) in freshwater at 30 °C. Ten fish per sampling point were examined after treatment. The data were fitted to two‐compartment open models following both routes of administration. The estimates of total body clearance (CL/F), volume of distribution (Vd/F), and absorption half‐life (T_1/2ka) were 0.049 and 0.037 L/h/kg, 0.41 and 0.33 L/kg, and 0.028 and 0.035 h following i.m. and i.p. administration, respectively. After i.m. injection, the elimination half‐life (T_1?2β) was calculated to be 5.81 h, the maximum plasma concentration (C_max) to be 49.40 μg/mL, the time to peak plasma cefquinome concentration (T_max) to be 0.14 h, and the area under the plasma concentration–time curve (AUC) to be 204.6 μg h/mL. Following i.p. administration, the corresponding estimates were 6.05 h, 44.39 μg/mL, 0.17 h and 267.8 μg h/mL. The minimum inhibitory concentrations of cefquinome, determined for 30 strains of Streptococcus agalactiae isolated from diseased tilapia, ranged from 0.015 to 0.12 μg/mL. Results from these studies support that 10 mg cefquinome/kg body weight daily could be expected to control tilapia bacterial pathogens inhibited in vitro by a minimal inhibitory concentration value of ≤2 μg/mL.     

基于深度学习的病虫害智能化识别系统

我国农作物种植覆盖面广、分散度高,病虫害发生种类多、区域性发生规律复杂,传统的人工鉴定技术从效率、能力与精度方面均难以满足新形势下重大病虫测报要求。针对这一实践需求,以测报灯下害虫图像数据库(约18万张)、田间病虫害图像数据库(约32万张)为基础,构建了基于深度学习方法的病虫害种类特征自动学习、特征融合、识别和位置回归计算框架,并研发了移动式病虫害智能化感知设备和自动识别系统。通过近2年的精确度和实操运行效率检验,该系统在自然状态下对16种灯下常见害虫的识别率为66%～90%,对38种田间常见病虫害(症状)的识别率为50%～90%。随基础数据库的不断丰富、神经网络深层特征提取的不断完善,该系统有望进一步提高识别准确率,从而真正实现田间病虫害识别自动化、智能化和高效率。