种青养鱼模式下的草鱼肌肉营养成分和品质特性

为探究种青养鱼养殖模式对草鱼肌肉营养成分和品质特性的影响,随机选取以种青喂草为主养殖模式下养殖的草鱼(生态草鱼)和投喂人工配合饲料进行养殖的草鱼(饲料草鱼)各16尾,测定其肌肉系水力和质构特性指标,以及肌肉常规营养成分、矿物元素、氨基酸和脂肪酸含量。结果显示,生态草鱼和饲料草鱼肝体比和空壳率无显著性差异;生态草鱼肌肉系水力指标中滴水损失显著低于饲料草鱼,冷冻渗出率不显著地低于饲料草鱼,失水率不显著地高于饲料草鱼,p H值无显著性差异;肌肉的硬度、弹性、凝聚性、胶黏性和回复性均无显著性差异;生态草鱼粗脂肪含量显著低于饲料草鱼,水分、灰分、粗蛋白含量均无显著性差异;生态草鱼P和Fe含量均显著高于饲料草鱼,Mg、Mn和Cr含量均极显著高于饲料草鱼;生态草鱼和饲料草鱼肌肉氨基酸组成基本一致,均含有17种氨基酸,其中人体必需氨基酸总量分别为6.85%和6.27%。生态草鱼必需氨基酸指数(EAAI)为76.07,而饲料草鱼为77.29,饲料草鱼略高于生态草鱼。生态草鱼和饲料草鱼肌肉均含19种脂肪酸,其中棕榈酸、花生四烯酸(ARA)、亚油酸(LA)、油酸、二十二碳六烯酸(DHA)和硬脂酸含量较高,为主要脂肪酸,而花生五烯酸(EPA)+DHA含量分别为8.95%和10.70%,且差异显著。研究表明,生态草鱼和饲料草鱼在肌肉质构特性方面无显著性差异,与饲料草鱼相比,生态草鱼具有肌肉系水力强、低脂肪和矿物元素含量高的特点。     

桑沟湾贝藻养殖区附着生物群落季节演替研究

从2007年5月～2008年4月,采用悬挂试网和直接从海区采集栉孔扇贝养殖笼样品两种方法,对桑沟湾贝藻养殖区的附着生物群落结构和季节演替规律进行了研究。结果显示,桑沟湾附着生物群落结构复杂,本实验鉴定的大型附着生物23种,玻璃海鞘、柄海鞘和紫贻贝是群落中的优势种。附着生物的生物量呈现明显的季节变化特征,试网上附着生物湿重与温度变化相关,生物量为0.003～1.21kg/m2,其中2月和8月分别具有最小和最大值。栉孔扇贝养殖笼的附着生物生物量9月为1.94kg/笼,之后随温度下降而减少,10月为0.99kg/笼,之后又有所上升,11月份为1.03kg/笼。生物量变化主要是由于优势种的演替引起的,随温度下降海鞘类逐渐消退,贻贝等成为优势种。     

日光温室草莓套种甘薯高效栽培技术

摘要：为助力现代都市农业发展,吸引市民采摘,丰富昌平草莓的种植结构,提高日光温室土地利用效率、实现全年可采摘,增加种植户种植效益,结合草莓种植环境特点,通过试验示范,推广了日光温室草莓套种甘薯高效栽培模式,于3月上中旬套种,6月下旬至7月上中旬陆续收获甘薯。模式省工、高效,延长了日光温室作物采收时间,增加了复种指数,吸收了土壤中残余的养分。通过合理的茬口安排、适宜的品种选择、病虫害防控等措施的综合应用,667 m2收益可提高10 750～15 750元。     

Effect of atorvastatin on ventricular remodeling in spontaneous hypertension rats

AIM：To explore the effect of atorvastatin on cardiac remodeling in spontaneous hypertension rats (SHR).METHODS：Twelve spontaneous hypertension rats were divided randomly into two groups：group of atorvastatin (atorvastatin 50 mg·kg^-1·d^-1) and group of SHR (0.5% mucilage of arabic gum,10 mL·kg^-1·d^-1).Additionally,six male Wistar-Kyoto rats (0.5% mucilage of arabic gum,10 mL·kg^-1·d^-1) were selected as control group.Systolic blood pressure was assessed with the tail-cuff method.After six weeks,entire heart,and left ventricle were weighed.The left ventricular weight index was calculated and myocardial hydroxyproline and collagen protein concentration were measured.The serum high sensitivity CRP (hs-CRP) was measured by nephelometry.The localization of vascular cell adhesion molecule (VCAM) in myocardium was investigated by immunohistochemistry assays.The level of NF-κB mRNA expression was detected with in situ hybridization.Ultrastructure in cardiac muscle was also observed under transmission electron microscope.RESULTS：The expression of myocardial VCAM and NF-κB in SHR group was stronger than that in WHY group.Compared with SHR group,entire heart weight,left ventricular weight,left ventricular weight index,serum hs-CRP,myocardial hydroxyproline and collagen protein concentration was decreased,the expression of myocardial VCAM and NF-κB in SHR group was weaker than that in atorvastatin treatment group.The myocardial pathological change such as incomplete karyotheca in cardiac muscle cells,no clear of transverse striation and the mess in myofibril alignment,and hyperplasy in interstitial collagen fibre were observed in SHR group and these changes were improved in atorvastatin treatment group.CONCLUSION：The cardiac remodeling in SHR is improved by atorvastatin.The molecular mechanism may be related to its down-regulating the expression of VCAM protein and NF-κB and inhibiting myocardial chronic inflammation.     

Characteristics of ventricular electrophysiology in a right ventricular rapid pacing-induced canine heart failure model

AIM: To research the characteristics of ventricular electrophysiology in right ventricular rapid pacing-induced congestive heart failure (CHF) dogs.METHODS: Dogs (n=16) were randomly divided into 2 groups: the control (n=7) and the CHF group (n=9) induced by rapid right ventricular pacing at 240 pulse·min-1 for 4 to 5 weeks.The electrophysiologic parameters were evaluated by the technique of standard electric stimulation and monophasic action potential (MAP) recording.RESULTS: (1) Ventricular effective refractory period (VERP),ventricular MAP duration (MAPD90),ventricular late repolarization duration (VLRD) and intra-ventricular conduction time (IVCT) were prolonged by 26% (P<0.01),43% (P<0.01),318% (P<0.05),and 19% (P<0.01),respectively in CHF group.(2)The ratio of VERP to MAPD₉₀ (VERP/MAPD₉₀) was decreased by 13% (P<0.05) in CHF group.(3) The dispersion of ventricular recovery time (VRT-D) was increased by 185% (P<0.01) in CHF group.(4) The ventricular fibrillation threshold (VFT) was decreased by 48% (P<0.01) in CHF group.CONCLUSION: The abnormal electrophysiological changes in the CHF condition may be contributing factors of lethal ventricular arrhythmias and sudden cardiac deaths in CHF.     

猪伪狂犬病灭活疫苗(HB-J株)对兔与猪免疫攻毒保护平行关系的研究试验

用研制的连续3批猪伪狂犬病灭活疫苗(HB-J株)分别以不同剂量免疫健康兔和断奶仔猪,检测其免疫28 d后的血清抗体,采用血清中和试验法测定血清中和指数,并对免疫28 d后的兔和断奶仔猪分别进行攻毒,统计各组兔和断奶仔猪免疫后攻毒保护率。结果表明,兔免疫28 d后的血清抗体中和指数为794～1258时保护率为60%～80%,血清抗体中和指数≥1479时可获得100%保护;仔猪免疫28 d后的血清抗体中和指数为229～269时保护率为60%～80%,血清抗体中和指数≥331时可获得100%保护。兔与仔猪对猪伪狂犬病灭活疫苗(HB-J株)均产生良好的免疫应答反应,抗体值较高者获得保护率相对较高,兔与猪免疫与攻毒保护呈现平行关系。     

电磁式电流互感器误差特性的分析

通过对电磁式电流互感器误差特性的分析，提出了互感器在正常工作时应注意的问题，进而提高互感器测量和保护的可靠性。     

宁夏东南部清水河、苦水河流域苦咸水水质综合评价

研究宁夏东南部地区清水河、苦水河流域的地表苦咸水水质状况,对解决苦咸水地区的水资源短缺和开发利用具有重要的意义。文中基于野外调查取样,获得相关的水质数据,采用主成分分析方法对矿化度、硬度、Na+等9个水质指标进行分析计算。主要结论有:矿化度、硬度是影响苦咸水水质的主要因素,但F-、NO3-毒理学指标也是不可忽视的重要因素;自清水河流域上游至下游,水质逐渐变差。苦水河流域与清水河流域的水质变化规律相反,自上游至下游水质呈转好趋势;据此,提出了分流、分类利用苦咸水的相关措施。     

北方规模种植果园昆虫种类调查及虫害防治——以黑龙江省宝清县为例

采用食诱法、陷阱法、网捕法和夜间灯诱法4种方法,在不同时间段对调查地昆虫进行采样调查。调查结果表明:在调查地发现昆虫101种属于42科,11目。通过调查结果进行分析,可采用合理种植与生态环境调节、生物农药、以虫治虫的手段,使规模种植果园发展成为无机绿色果园。     

土壤水分胁迫对紫花苜蓿光合特性及其生物量的影响

紫花苜蓿是我国重要的豆科牧草,具有较强的抗旱能力,而水分亏缺是影响其产量的主要逆境因子之一。通过大田试验对不同水分胁迫下紫花苜蓿的光合特性及产量进行研究,结果表明:①土壤水分胁迫对紫花苜蓿光响应参数影响显著(P<0.05),随着水分胁迫的加剧,最大净光合速率、表观量子效率、光饱和点逐渐降低,暗呼吸速率、光补偿点逐渐升高,从而直接影响紫花苜蓿光合作用对弱光的吸收和转化效率。②随着水分胁迫的加剧紫花苜蓿叶片的净光合速率(Pn)和蒸腾速率(Tr)呈显著的下降趋势,气孔导度(Gs)呈先下降后上升的趋势,表明轻度水分胁迫下气孔因素是Pn下降的主要因素,中度和重度水分胁迫下非气孔因素是Pn降低的主要因素。③当光合有效辐射(PAR)为1200μmol·m^-2·s^-1时,轻度水分胁迫的水分利用效率(WUE)显著大于充分灌溉的WUE(P<0.05),表明适度水分胁迫可提高紫花苜蓿叶片的水分利用效率。④轻度水分胁迫与充分灌溉干草产量之间无显著差异,表明轻度水分胁迫能达到高产节水的目的。