家兔板层角膜移植及效果观察

在普通手术条件下,对8只白色青年家兔(4只供体和4只受体)进行了板层角膜移植手术;在4只受体兔中,A兔和D兔采用连续缝合法,B兔和C兔采用间断缝合法。观察发现,4只受体兔均有抓挠眼部和互相舔眼现象;A兔在术后第6天突然死亡,但角膜植片完好,剖检见肠道出血;B兔和C兔分别在术后第6天和第8天角膜植片脱落,但无明显炎症反应;D兔到术后第15天时角膜完全透亮,整个缝线清晰可见,分辨不出植片边缘,第16天拆除缝合线。结果表明,兔角膜移植的术后护理很难,原因是他们不仅没有自我保护意识,反而有自我伤害行为;B兔和C兔的植片脱落与瞬膜摩擦、抓挠眼部和互相舔眼有很大关系。     

速眠新麻醉剂在绵羊胚胎移植手术中的应用

在绵羊胚胎移植供、受体麻醉中,用速眠新麻醉剂以肌肉注射和静脉注射2种方法给药,测定了麻 醉绵羊进入麻醉期的各项生理常数,观察了麻醉诱导期、麻醉期、苏醒期绵羊的表现及其所用时间,综合评定了麻 醉效果。结果表明,两种麻醉方法均可以取得良好的麻醉保定效果。与肌肉注射麻醉相比,静脉注射麻醉的用药量 只有肌肉注射的1／5-1／7,麻醉绵羊进入麻醉期时间短(平均1．03-3．82 min),手术后苏醒早,有利于提高胚胎移 植手术的效率,而且安全性较高。研究还发现,不同品种绵羊对速眠新的反应有差异,体重、体况、气候等因素均影 响麻醉剂的用药量和麻醉效果。     

速眠新麻醉剂在山羊胚胎移植手术中的应用

【目的】筛选适合于山羊胚胎移植的速眠新静脉注射麻醉剂量。【方法】以关中奶山羊为试验动物,速眠新Ⅱ注射液为麻醉剂,研究静脉注射麻醉时,不同剂量速眠新Ⅱ注射液对不同体重组(28~35,36~45和46~55kg)山羊的麻醉效果;同时比较了速眠新Ⅱ注射液2种麻醉方法(静脉注射和肌肉注射)对山羊生理指标,心电图,麻醉山羊的诱导期、麻醉期、苏醒期,麻醉苏醒后山羊的采食、反刍及精神状况的影响。【结果】(1)山羊胚胎移植受体静脉麻醉时,山羊体重为28~35,36~45及46~55 kg时,最适宜麻醉剂量分别为0.4,0.4和0.5 mL/只。(2)与麻醉前相比,麻醉后山羊的体温升高,呼吸次数和心率均降低。(3)2种麻醉方法下,麻醉效果优、良山羊的心电图均正常,无差异。(4)速眠新Ⅱ注射液静脉注射麻醉时,山羊的诱导期、麻醉期和苏醒期均较短,在苏醒后0.5 h,92.8%和87.5%的山羊可以采食和反刍,95.3%的山羊精神状况良好;苏醒后1 h基本上全部可以恢复正常。【结论】采用静脉注射麻醉山羊进行胚胎移植手术,速眠新Ⅱ注射液用药剂量小,且安全、有效,明显优于肌肉注射。     

农业区位论及其现实意义

农业区位论是解决农业生产的区位选择问题的理论 ,适用于特定的生产力水平和社会条件。农业区位论从孤立化研究和区位地租出发 ,得出了农产品种类围绕市场呈环带状分布的理论化模式。在市场经济新形势下 ,对农业区位论进行全方位的重新探索、分析与评价 ;重新认识农业区位论在中国农业经济发展中的现实应用和启示作用 ,更好地推动中国现代区位理论研究和农业产业结构调整。     

高校图书馆按学科分配购书经费的探讨

分析了高校图书馆购书经费分配方案的重要性,阐述了高校图书馆分配购书经费的3个步骤,指出按学科分配购书经费要考虑馆藏评估、用户、课程、项目、目标、出版等因素。     

农业观光园中观赏蔬菜景观的配置

介绍农业观光园中观赏蔬菜景观配置的5种主要形式及配置原则,并提出注意事项。     

基于遗传算法的网络计划资源优化研究

以双代号网络计划技术为工具,提出一种基于遗传算法的建筑工程"资源有限,工期最短"问题的求解模型。针对问题的特点,设计了相应的遗传算子并提出一种用于修正非法染色体的修复算子。算例表明,该方法计算结果优于传统的启发式方法,可较好应用于建筑工程资源优化问题。     

Land-use allocation protects the Peruvian Amazon

Disturbance and deforestation have profound ecological and socioeconomic effects on tropical forests, but their diffuse patterns are difficult to detect and quantify at regional scales. We expanded the Carnegie forest damage detection system to show that, between 1999 and 2005, disturbance and deforestation rates throughout the Peruvian Amazon averaged 632 square kilometers per year and 645 square kilometers per year, respectively. However, only 1 to 2% occurred within natural protected areas, indigenous territories contained only 11% of the forest disturbances and 9% of the deforestation, and recent forest concessions effectively protected against clear-cutting. Although the region shows recent increases in disturbance and deforestation rates and leakage into forests surrounding concession areas, land-use policy and remoteness are serving to protect the Peruvian Amazon.     

Energy uptake and allocation during ontogeny

All organisms face the problem of how to fuel ontogenetic growth. We present a model, empirically grounded in data from birds and mammals, that correctly predicts how growing animals allocate food energy between synthesis of new biomass and maintenance of existing biomass. Previous energy budget models have typically had their bases in rates of either food consumption or metabolic energy expenditure. Our model provides a framework that reconciles these two approaches and highlights the fundamental principles that determine rates of food assimilation and rates of energy allocation to maintenance, biosynthesis, activity, and storage. The model predicts that growth and assimilation rates for all animals should cluster closely around two universal curves. Data for mammals and birds of diverse body sizes and taxa support these predictions.     

多维尺度配水模型研究

针对传统一维配水模型只能考虑1个变量的缺点,用多维尺度(MDS)模型构造了适应复杂流域的包含配水水量、用水区位置和用水区需水概率等变量的多维实时配水模型,并以黄河流域天然径流的配置为例,用MDS配水模型计算了黄河干流节点在一定区域需水概率情况下,天然径流量的配置情况。与传统一维配水模型计算结果相比,MDS配水模型可以分区域计算天然径流量的配置情况,并可以计算区域需水变化情况下各区域水量配置的调配情况。该模型的建立为区域的实时配水决策提供了方法上的参考。     

Interindividual variation in posture allocation: possible role in human obesity

Obesity occurs when energy intake exceeds energy expenditure. Humans expend energy through purposeful exercise and through changes in posture and movement that are associated with the routines of daily life [called nonexercise activity thermogenesis (NEAT)]. To examine NEAT's role in obesity, we recruited 10 lean and 10 mildly obese sedentary volunteers and measured their body postures and movements every half-second for 10 days. Obese individuals were seated, on average, 2 hours longer per day than lean individuals. Posture allocation did not change when the obese individuals lost weight or when lean individuals gained weight, suggesting that it is biologically determined. If obese individuals adopted the NEAT-enhanced behaviors of their lean counterparts, they might expend an additional 350 calories (kcal) per day.     

康复医学资源配置中存在的问题及对策

分析了中外康复医学资源配置现状,从人力资源、康复教育、加大政府卫生投入和制定相关配套政策、康复机构和设备、建立康复医学信息资源共享平台5个方面提出相应的解决对策。     

太原市水资源合理配置研究

【目的】探讨太原市水资源的合理配置方案,使有限的水资源得到合理利用,促进经济与社会的可持续发展。【方法】以区域经济发展与水环境保护相协调为目标,建立水资源多目标优化配置模型,并利用大系统分解协调方法,针对不同水平年(2010,2020,2030年),进行太原市水资源优化配置研究。【结果】在现有供水工程、常规节水方案条件下,太原市水资源供需矛盾日益加剧,在50%和75%水文年份,太原市缺水率分别由2010年的不足1%和7.7%均上升为2030年的35%以上;采用高节水方案时,在50%和75%水文年份,到2030年太原市缺水率为26%~31%。【结论】要深度解决太原市缺水问题,应实行开源节流与污染治理并举的措施,在进一步加大节水力度的基础上,增大污水处理回用和引黄力度。