城市公园绿地空间布局与供需匹配研究——以兰州市为例

以兰州主城区为例，运用核密度估计法，在对公园绿地空间布局特征分析的基础上，采用改进的两步移动搜索法对公园绿地供需匹配性进行评价，并探究其成因。结果表明:1)公园绿地总体分布呈现整体分散、局部集中的特征；不同类型公园绿地空间布局模式存在较大差异，综合公园呈现“均匀式”布局态势，专类公园呈现“双核心”空间格局，社区公园呈现“西密东疏”的集聚特征。2)主城区公园绿地供需匹配程度总体呈现出“北高南低、西高东低”空间分布特征；从西北—东南向剖面来看，总体呈现出“M”型分布态势；不同类型公园绿地供需比值均大致呈现出“西高东低”的共性特征，但由于各类公园绿地分布数量、面积和服务半径的差异，不同类型公园绿地与人口供需匹配程度也存在差异。3)人口分布、交通路网、公园绿地自身及周边环境是影响城市公园绿地供需匹配度空间分异的主要因素。     

牛TLR4基因生物信息学分析

为了更加深入地了解牛TLR4基因的功能、结构及与该基因有关联的疾病识别及其致病机理,利用牛TLR4基因的氨基酸序列对其编码蛋白的基本理化性质、蛋白质译后的磷酸化位点和糖基化位点以及跨膜结构域和蛋白质结构进行预测。结果显示,牛TLR4基因一共编码841个氨基酸,负电荷残基总和(Asp+Glu)为84,正电荷残基总和(Arg+Lys)为76,不稳定指数小于40,表明该基因编码产物稳定性较好。在该基因整个编码产物中,亲水氨基酸占比较多,平均分值为-0.011,由此得知TLR4基因编码的蛋白质是一种易溶蛋白。有9个潜在的N-糖基化位点;78个磷酸化位点以及存在一个跨膜蛋白和存在信号肽,其切割位点在第25和第26个氨基酸之间。蛋白质的二、三级结构预测结果显示,二级结构和三级结构均由α-螺旋、β-折叠和无规则卷曲组成,其在生物合成、基因表达与调控等方面有重要作用。本研究结果可为牛TLR4基因深入研究提供理论基础。     

Effects of histone hypomethylation induced by alcohol during pregnancy on overexpression of cardiomyogenesis genes offspring mice

AIM:To investigate the effects of histone methylation on the abnormal expression of cardiomyogenesis genes caused by alcohol during pregnancy and the regulatory mechanism, and to provide a new idea and intervention targets for preventing and curing congenital heart disease. METHODS:The alcohol (56%, 5 mL/kg) and G9a-histone methyltransferases (HMT) inhibitor BRD4770 (1 mg/kg) were given by gavage in Kunming mice during embryo (E) 0.5~14.5 d, and the hearts of the mice in E14.5, E16.5 and post neonatal 0.5 d (PND0.5) were collected. The mRNA expression of Gata4, Cx43 and β-MHC genes was detected by RT-qPCR. The activity of HMT was measured by colorimetry. Meanwhile, the protein expression of histone H3K9me3, G9a-HMT, Cx43 and β-MHC was determined by Western blot. RESULTS:The results of colorimetry showed that the activity of HMT in the heart of the offspring mice treated with alcohol during pregnancy was decreased significantly compared with normal saline group (P<0.05), and Western blot data showed that the expression of G9a-HMT and histone H3K9me3 were apparently decreased in the same samples (P<0.05). The mRNA expression levels of Gata4, Cx43 and β-MHC in alcohol group were apparently increased compared with normal saline group (P<0.05). Meanwhile, the protein levels of Cx43 and β-MHC were increased significantly in the same samples (P<0.05). However, BRD4770, a G9a-HMT inhibitor, further attenuated the level of histone H3K9me3, and further upregulated the expression of Gata4, Cx43 and β-MHC in the heart of the the mice treated with alcohol (P<0.05). CONCLUSION:Histone methylation modification imbalance induced by G9a-HMT may be involved in the abnormal expression of cardiomyogenesis genes in the heart of offspring mice caused by alcohol during pregnancy.     

病程相关蛋白在采后果蔬诱导抗病性中的研究进展

果蔬受到真菌、细菌或病毒侵染时,自身能诱导产生病程相关蛋白(Pathogenesis-related proteins,PRs)。根据它们的结构亲缘关系和生物活性,PRs被分为17个功能家族。在控制果蔬采后病害的研究中,利用激发子诱导产生果蔬抗性已逐渐成为果蔬采后病害防治中一种安全、高效的保鲜方法,这也成为果蔬采后抗病研究的热点和发展趋势。本文综述了果蔬病程相关蛋白的分类、功能、诱导表达,以及蛋白组学技术在果蔬采后PRs表达水平上的应用,以期为果蔬病程相关蛋白的研究提供借鉴和参考。     

翻心型大白菜新品种连狮1 号的选育

连狮1 号是以连云港地区菜农提供的中狮头自留种为原始种，经4 代自交提纯选育成的大白菜新品种。株型紧凑， 整齐度较好，叶球为长筒翻心形，叶片呈长倒卵形，叶表面具有较深核桃纹并带稀疏茸毛。株高35 cm，外叶数约10 片， 叶球高28～32 cm、横径22～27 cm，单个叶球质量3.5～4.0 kg，每667 m² 叶球产量4 700 kg 左右，净菜率达83%。生育期 为90～95 d（天），田间抗病毒病、霜霉病、根肿病能力优于对照中狮头，适合在江苏、安徽、山东等地及其相近气候条件 地区秋季种植。     

Importance of mitochondrial calcium uniporter in high glucose-induced cardiac myocyte apoptosis

AIM: To investigate the role of mitochondrial calcium uniporter (MCU) in high glucose(HG)-induced apoptosis of cardiac myocytes. METHODS: Cardiac myocytes were exposed to normal glucose (5.5 mmol/L glucose+ 19.5 mmol/L mannitol), HG (25 mmol/L glucose), or HG combined with 5 μmol/L spermine for 72 h. Mitochondrial free Ca²⁺ concentration ([Ca²⁺]_m), MCU at mRNA and protein levels, pyruvate dehydrogenase (PDH) activity, mitochondrial membrane potential (Δψ_m), the levels of ATP and reactive oxygen species (ROS), and apoptosis were determined. RESULTS: The [Ca²⁺]_m, the mRNA and protein levels of MCU, PDH activity, ATP levels, and Δψ_m were reduced (P<0.05), while ROS content and the protein levels of caspase-9 and caspase-3 were increased in HG group (P<0.05). Adding 5 μmol/L spermine returned these parameters toward control levels (P<0.05). Moreover, apoptosis was reduced by adding spermine and HG treatment (P<0.05). CONCLUSION: HG-induced cardiac myocyte apoptosis may be associated with the decreased MCU expression and activity, abnormal mitochondrial Ca²⁺ handling, deviant mitochon-drial respiratory chain, and mitochondrial dysfunction.     

茄子新品种海丰长茄1 号的选育

海丰长茄1 号是以双单倍体（DH）株系02-QP-19 为母本，优良自交系A-40 为父本配制而成的长茄一代杂种。平
均始花节位为第9 节，植株生长势强，叶片绿色，叶脉、叶柄和主茎的颜色为紫色，植株半开张类型。果实平均纵径31.5
cm，横径4.5 cm，果皮紫黑色，有光泽，果实顶部尖，平均单果质量220 g，VC 和VP 的含量分别为23.2 mg·kg^-1 和0.035%。
一般每667 m² 产量5 000 kg 左右。适宜北京、吉林和黑龙江等地区露地种植。     

'白鸡冠'半同胞系F1代新品系性状比较及遗传多样性分析

以'白鸡冠'半同胞系F1代中13个新品系为研究对象,观测其新梢、成熟叶片等生物学性状及利用SSR标记分析其遗传多样性.结果发现,与母本相比F1代新品系树型全为灌木型,树姿均为半披张,大部分为小叶种;芽叶色泽为黄绿的有8个,5个为紫绿或者绿色;新梢一芽三叶重超过母本的有7个;生化测定表明各品系水浸出物、茶多酚、儿茶素、咖啡碱差异不大;而游离氨基酸从3.5%~6.3%,变化幅度达到80%,变异幅度较大.遗传多样性分析发现0309B与母本白鸡冠亲缘关系最远,而0309D与0306I与母本亲缘关系最近.     

黑果枸杞茎叶生长及其生态化学计量特征对灌水施肥的响应

在石羊河中游田间条件下,通过灌水和施肥调节黑果枸杞生长。测定不同时期黑果枸杞茎、叶生长量及其化学计量学特征变化,分析器官水平生长速率与化学计量学特征的关系,验证生态化学计量学理论"生长速率假说"。灌水施肥显著促进了茎长、基径和叶片长、宽及叶干重的生长(P<0.05),而茎长、基径、叶面积和叶干重的相对生长速率与对照之间无显著差异。各处理下黑果枸杞新梢C含量及C∶N、C∶P随生育期进程呈增加趋势,而N、P及N∶P呈降低趋势;灌水和施肥处理后茎C含量及C∶N、C∶P、N∶P低于对照,茎N、P含量高于对照。各处理叶片C、N、P含量在生育期内呈降低趋势,而C∶N、C∶P及N∶P呈增加趋势;灌水和施肥后叶片C含量及C∶N、C∶P、N∶P低于对照,叶片N、P含量高于对照。茎C含量及C∶N、C∶P显著高于叶片(P<0.05),而N、P含量及N∶P显著低于叶片(P<0.05)。生长速率假说认为,生物个体的生长速率与体内的N∶P、C∶P具有负相关关系,与N、P含量呈显著的正相关关系。各处理黑果枸杞茎、叶的生长速率与其N、P含量及C∶P、N∶P总体相关性不显著。表明施肥灌水调节下黑果枸杞茎叶生长及化学计量学特征不支持生长速率假说。     

基于LMDI的长江经济带农业用水驱动因素分析

水资源优化配置成为长江经济带农业农村绿色发展的核心议题,厘清农业用水量变化的内在驱动因素及影响效应是关键。基于2002—2017年长江经济带11个省(市)的面板数据,利用对数平均迪氏指数法(LMDI)将农业用水影响因素分为技术水平、产业结构、生产水平和人口规模,进而分析不同因素对农业用水变化的效应。结果表明,从总体来看,产出效应和人口效应促进农业用水增长,其中产出效应占主导地位;技术效应和结构效应对农业用水量起抑制作用。从区域来看,上海市、安徽省、江西省、湖北省、重庆市、四川省和贵州省总体对农业用水起促进作用,江苏省、浙江省、湖南省和云南省总体对农业用水起抑制作用。