辐照对黄原胶分子量及抗氧化活性的影响

以0~500kGy 60Co γ射线对固态黄原胶进行辐照,研究辐照对黄原胶分子量及还原力、清除1,1-二苯基-2-苦基肼自由基（DPPH·）、超氧自由基（O2-·）及羟自由基（·OH）能力等抗氧化活性的影响。研究表明,10kGy的辐照可使黄原胶粘均分子量从1.71×106增加到2.23×106,超过10kGy后,黄原胶粘均分子量随辐照剂量的增大逐渐减少,500kGy时降为1.59×104。低于10kGy辐照,黄原胶的还原力、对DPPH·和对O2-·的清除率与剂量呈负相关,与对照相比,还原力降低了3.16%,对DPPH·和O2-·的清除率分别从17.37%和18.18%减少到16.87%和8.51%,增大辐照剂量,黄原胶的还原力和对DPPH·和O2-·的清除率与剂量呈正相关,500kGy时黄原胶的还原力比对照增加164.22%,对DPPH·和O2-·的清除率升高至60.79%和30.06%;对·OH清除能力与辐照剂量呈负相关,清除率从0kGy时的9.29%降低到500kGy时的3.63%。辐照可以引起黄原胶聚合或降解,从而导致其分子量及抗氧化活性发生显著变化。     

农业院校实验室开放的探讨

从农业院校培养高素质人才的需要出发,结合实验教学的现状,阐述实验室开放的必要性、可行性及保障措施。实践证明,开放实验室可以为学生能力的培养创造良好的条件,提供更多的锻炼机会。     

提高葡萄杂交育种效率的研究

以瑞必尔×红双味,京秀x红地球杂交组合及瑞必尔、红地球、醉人香实生种子为试材,通过3种不同处理的田间杂交授粉方法以提高田间葡萄杂交授粉率及对葡萄实生种子进行3种不同的处理以提高葡萄种子的萌发能力.结果表明:以处理Ⅳ即从去雄后第2 d起连续3次授粉处理的葡萄杂交组合坐果率最高,瑞必尔×红双味,京秀×红地球杂交组合分别达到了55.8%和44.8%.3种种子处理方法中以处理Ⅱ温室营养钵播种法成苗率最高,瑞必尔、醉人香、红地球实生种子的成苗率分别达到了35%、30%和30%.     

天津地区土壤中可溶性盐分测定方法的探讨

可在不同检测地区利用春季返盐季节刮取盐皮，精制烘干，配制系列标准溶液用电导法测定，做出效应方程，以此计算待测样品含盐量，其结果较接近于田间状况，且方法简便，快捷，适合于天津地区土壤可溶性盐分测定。     

饲用型沙棘优良单株选择研究

对引种的不同饲用型沙棘品种进行优良单株选择,以近3年的实测资料为基础,进行数据处理与分析,选择10 cm枝长叶片数、单株叶产量、新梢数为主要筛选指标,采用相似优先综合排序的方法进行初选、复选与终选,确定饲用型优良单株.通过3次筛选,选出单株产叶量较高的饲用型沙棘优良单株17株,其中俄混品种8株、草新2号5株、俄罗斯沙棘4株.     

广东省大中型水库可持续发展条件

当今世界，水资源是制约经济发展的重要因素。在广东省，水库是调节水资源的主要手段，因而水库的可持续发展直接关系到广东省经济能否稳步发展。在对广东大中型水库进行调研的基础上，分析了广东省水库农业水价执行过程中存在的一些问题，在农业水价管理体制方面提出一些建议，旨在为广东省农业水价改革及促进水库的可持续发展提供参考。     

黑白花妊娠母牛产前体温变化与分娩关系的研究

采用直肠测温方法，对黑白花妊娠母牛（ｎ＝２３头）产前１个月每天测定体温。结果表明，妊娠在产前一月体温逐渐升高，至产前第７－８天平均达３９．１８℃；至产前１２小时，降到３８．８１℃，与空怀母牛平均体温相近（３８．７９℃）。试验表明，本方法可以作为计算预产前和观察临床征候方法的可靠补充。     

河南鸡公山国家级自然保护区森林生态旅游资源开发利用构想

通过对鸡公山国家自然保护区旅游资源及开发利用现状分析,提出了在该地区开发森林生态旅游的必要性以及必须遵循的原则。在此基础上根据当地旅游资源特征对生态旅游项目提出了几点建议。     

绵羊冷冻精液稀释液中添加复合维生素B提高冻精解冻后品质的研究

将山梨醇、氯前列烯醇、复合维生素B在绵羊冷冻精液稀释液中进行添加、筛选。解冻后活率结果显示1号稀释液(41.17±4.72)%和4号稀释液(37.76±3.15)%极显著地高于对照组稀释液(22.80±4.49)%(P<0.01)。表明在绵羊冻精稀释液中添加复合维生素B可有效提高冻精解冻后活率并保护精子形态结构的完整性。     

The clinical use of the neuromuscular blocking agent rocuronium in dogs

Objective The aim of this study was to characterize the onset and duration of action of the aminosteroid muscle relaxant rocuronium in dogs under clinical conditions. Study design Prospective single dose trial. Animals Twenty‐three dogs aged between 6 months and 12 years, weighing between 5.5 and 61.5 kg admitted to the University of Liverpool Small Animal Hospital between January and March 2000, and undergoing elective surgical procedures under general anaesthesia. Materials and methods Following induction of general anaesthesia, neuromuscular function was evaluated using train‐of‐four (TOF) stimulation. An initial dose of 0.4 mg kg^?1 rocuronium was administered intravenously (IV) and neuromuscular blockade was monitored by visually assessing the number of responses (twitches) to TOF stimulation (train‐of‐four count: TOFC). Incremental doses of 0.16 mg kg^?1 rocuronium were administered as indicated, when at least two twitches of the TOFC had returned. Results Rocuronium (0.4 mg kg^?1) abolished all responses to TOF stimulation in all dogs. The mean time to onset of neuromuscular blockade (complete abolition of all twitches) was 98 ± 52 seconds. Neuromuscular blockade (absence of all twitches to return of all four) lasted 32.3 ± 8.2 minutes. Incremental doses of 0.16 mg kg^?1 had a mean duration of action of 20.8 ± 4.9 minutes and up to seven increments were shown to be noncumulative. The effects of rocuronium were readily antagonized with neostigmine and atropine. Small transient increases in arterial blood pressure, which occurred in three dogs after the administration of rocuronium, were the only cardiovascular side‐effects observed. Conclusions Rocuronium is an effective nondepolarizing neuromuscular blocking agent in the dog, with a rapid onset of neuromuscular block after intravenous administration and an intermediate duration of action. Clinical relevance Rocuronium produced a neuromuscular block with similar characteristics to those obtained with vecuronium, thus apparently offering little advantage over vecuronium. However, its availability in aqueous solution and a longer shelf‐life increases convenience.