通过非线性控制使一个捕食-被捕食系统永久持续生存

本文通过非线性控制研究了一个捕食－被捕食系统。通过非线性控制使一个捕食－被捕食开环系统变成永久持续生存的闭环系统,并给出了使闭环系统永久持续生存的充分条件。     

一个二维竞争系统的诱导控制

利用诱导控制研究了一个二维竞争系统,对两种群同时进行诱导控制,得到了使被研究模型永久持续生存的一些充分条件。     

通过线性状态反馈使四种群Lotka—Volterra模型永久持续生存

本文研究了四种群Lotka0-Volterra模型的永久持续生存问题,给出了通过线性状态反馈使四种群Lotka-Volterra模型永久持续生存的一些充分和必要条件。     

非自治带扩散的Kolmogorov系统的持续生存性

本文把持续生存的定义推广到ｎ个种群ｍ个缀块间扩散的非自治Ｋｏｌｍｏｇｏｒｏｖ系统中去,应用持续生存函数,讨论了系统的一致持续生存性和永久共存性,获得了系统持续生存的几个充分条件,并应用上述结果讨论了具有一生非自治扩散的Ｌｏｔｋａ－Ｖｏｌｔｅｒｒａ系统持续生存性。     

n阶食物链反馈控制系统的稳定性与永久持续生存

本文研究了n阶食物链反馈控制系统的稳定性与永久持续生存问题，分别得到了该系统无反馈与有反馈两种情况下存在唯一正平衡点和永久持续生存的几个充要条件。文末的例子表明，本文在无反馈情况下的结果比现有的结果简单，有效，在有反馈情况下的结果填补了目前这一问题的空白。     

捕食者与食饵均具有阶段结构捕食系统的研究

本文研究周期系数捕食者与食饵均具有阶段结构的两种群的捕食系统,得到了系统永久持续生存和周期解存在以及全局渐近稳定的充分条件。     

具有时滞的非自治差分竞争系统的渐近行为研究(英文)

提出了一个具有时滞的非自治差分竞争系统.分别利用差分不等式及Lyapunov离散函数技巧,得到了系统永久持续生存和正解全局吸引的充分条件.数值模拟验证了理论结果的正确性.     

一类具有广义Logistic增长的比率型捕食模型的定性分析

对具有广义Logistic增长的比率型捕食模型进行了分析,得到了系统永久持续生存的充分条件．通过对系统进行无量纲代换和应用Liapunov函数的方法,进一步得到了正平衡点全局渐近稳定的充分条件．     

一个具有扩散和时滞的捕食模型的持久性与周期解的存在性

对一类在斑块环境下具有Beddington型功能性反应和时滞现象的非自治捕食系统进行了研究,证明系统在适当的条件下是永久持续生存的;利用重合度理论,得到了一组保证该系统存在正周期解的充分条件．     

具有阶段结构和Leslie-Gower HollingⅡ功能性反应的脉冲食饵-捕食系统(英文)

我们考虑了一个具有阶段结构和Leslie-Gower HollingⅡ功能性反应的时滞脉冲食饵-捕食系统.运用脉冲微分方程的比较定理和小扰动的方法,我们得到了保证系统食饵灭绝周期解的全局渐近稳定性和系统永久持续生存的条件.     

家蝇幼虫血淋巴中抗真菌肽的诱导方法比较及抗真菌活性

以未诱导组作为空白对照研究比较真菌诱导、超声诱导和热诱导家蝇Musca domestica 幼虫血淋巴初提液的抗真菌肽效果,比较各种诱导方法诱导后的幼虫存活率;用凝胶层析法和高效液相分离纯化热诱导家蝇3龄幼虫抗真菌肽,检测其抗白假丝酵母菌Candida albicans和新生隐球菌Cryptococcus neoformans活性;SDS-PAGE分析抗真菌肽的蛋白分子量范围。结果表明：3种诱导方法诱导后家蝇幼虫均产生具有明显抗真菌作用的抗真菌肽,其初提液抑菌圈大小没有明显差别;真菌诱导组和热诱导组幼虫存活率低于对照组,而超声诱导组与对照组相比则无明显差别。经分离纯化后,抗真菌肽仍具有较好的抗真菌活性;SDS-PAGE分析表明该抗真菌肽有效成分的蛋白分子量在14.4 kD以下。结果提示热诱导家蝇幼虫产生抗真菌肽是一种方便、有效的诱导方式。     

异氟醚与七氟醚复合麻醉在小儿全身麻醉中的应用

目的:探讨异氟醚及七氟醚复合麻醉在患儿全身麻醉中的应用。方法:选取陕西省榆林市第一医院儿科收治的需行ASAⅠ或Ⅱ级行外科手术患儿86例,随机分为两组,其中对照组43例给予异氟醚全身麻醉诱导;实验组43例予以异氟醚及七氟醚复合全身麻醉诱导。观察比较两组麻醉诱导时间(T1)、苏醒时间(T2)、aldrete评分达9分或9分以上时间(T3)以及不良反应发生率。结果:实验组患儿麻醉诱导时间、苏醒时间、aldrete评分为9分或9分以上时间均明显少于对照组,差异具有统计学意义(P0.05);实验组患儿不良反应发生率明显低于对照组,差异具有统计学意义(P0.05)。结论:异氟醚及七氟醚复合麻醉能够缩短麻醉诱导时间、苏醒时间及术后恢复时间,具有较高的安全性,值得临床推广应用。     

桃叶片抗冷性对光周期诱导休眠的响应

以6年生“春捷”桃树为试材,以自然生长的桃树为对照,研究了长日照和短日照的休眠诱导效应和休眠诱导进程中叶片抗冷性对光周期的响应.结果表明: 在逐渐降低的自然环境温度下,长日照和短日照处理树体均能进入休眠诱导期,其中长日照处理延后1周而短日照处理提前1周进入.随着休眠程度的加深,各处理叶片的总含水量、自由水含量降低,束缚水含量、束缚水/自由水比值升高.超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性在休眠诱导期内均呈单峰曲线,高峰值出现在休眠诱导期的后期,过氧化物酶(POD)活性进入休眠诱导期后迅速下降,后期回升形成小高峰.休眠诱导期内可溶性蛋白含量稳步下降,脯氨酸和丙二醛(MDA)含量持续升高,伤害率逐渐增大.长日照可显著提高SOD、CAT活性及脯氨酸含量,减缓POD活性和可溶性蛋白含量的降幅,降低MDA和伤害率的增幅.这表明长日照处理叶片受伤害程度更轻,而短日照处理相应指标的变化则不同,尤其诱导期后期叶片的伤害率显著高于对照,表现出较低的抗冷性.如果环境温度允许,实际生产中可以适当延长光照时间来提高叶片的抗冷性.     

低体质量小儿心脏手术中应用七氟醚全身麻醉诱导的效果及其对血流动力学的影响

目的:探讨低体质量小儿心脏手术中应用七氟醚全身麻醉诱导的效果及其对血流动力学的影响。方法:选择本院2016年7月-2018年2月期间收治的28例低体质量小儿心脏手术患儿纳入本研究,按照随机数字表法将患儿分为对照组和观察组各14例。对照组采用氯胺酮进行全身麻醉诱导,观察组采用七氟醚吸入麻醉进行全身麻醉诱导。观察两组患儿麻醉诱导敏感性及不良反应等情况,比较两组患儿诱导前、诱导过程中、插管即刻的收缩压(SBP)、舒张压(DBP)、心率(HR)及血氧饱和度(SaO2)水平。结果:观察组患儿哭闹时间、睫毛反射消失时间及疼痛反射消失时间显著低于对照组(P0.05)。观察组患儿不良反应发生率为7.14%(1/14),与对照组的28.57%(4/14)比较差异无统计学意义(P0.05)。诱导过程中及插管即刻,对照组患儿SBP、DBP均低于诱导前和观察组,HR高于诱导前和观察组,SaO_2先降低后升高,且低于观察组(P0.05),观察组患儿SBP低于诱导前,SaO2高于诱导前(P0.05),而DBP、HR与诱导前比较无统计学差异(P0.05)。结论:与氯胺酮相比,采用七氟醚吸入全身诱导麻醉,其对低体质量小儿心脏手术患儿的循环干扰较小,同时在诱导过程中安全稳定,对血流动力学影响较小,容易被患儿所接受。     

The Relationship Between Flowering Induction and the Level of Adenosine Triphosphate in Pharbitis nil

A study has been made on the changes of ATP and protein content in cotyledons and apices of Pharbitis nil after flowering induction. Protein content of the cotyledons which have just got through the induction is 68% higher than that of the control, but the difference trends to disappear there after. The. difference of protein content between the induced and uninduced apices is not so obvious in the first three days after induction, but quite evident on the fourth day (30% higher in the induced apices) suggesting that there is some relationship between protein metabolism and flowering induction both in the cotyledons and in the apices. Just after the seedlings have been induced, ATP content of the cotyledons is getting much (134%) higher than that of the control and the tendency is retained towards the fourth day after induction. Generally ATP content in apices is one order of magnitude higher than that in cotyledons. Although ATP content in the apices is only slightly higher than that of the control soon after induction, it gains quite a lot in the second day until the fifth day the end of our experiment. In the third day after induction ATP level in the apices reaehs to the maximum (20.6×10-2 μmol/g, apices) which is 37% higher than that of the control. The results show that flowering induction is bound to be followed by increase of proteins and ATP both in apices and in cotyledoms. It also. shows both formation of the stimulus in induced cotyledons and evocation in the apices might be all concerned in expression of some genes and synthesis of new RNA and protein. According to the maximum peak of ATP in the apices and cotyledons appeared in 3rd to 4th day after induction, it seems that the inductive effect both in the cotyledons and apices might continue for some time under the following uninduced condition.     

右美沙芬用于80 例胆囊切除术后镇痛的临床观察与分析

目的:观察和分析右美沙芬用于80例胆囊切除术的超前镇痛作用临床疗效。方法:将2009年8月~2011年11月我院接收并确诊的80例ASAⅠ~Ⅱ级择期行腹腔镜胆囊切除手术患者,按患者意愿随机分为两组。治疗组40例,麻醉诱导前30min肌注右美沙芬20mg;对照组40例,麻醉诱导前30min肌注等量生理盐水。术中监测患者的血氧饱和度值、心率、平均动脉压等;术后统计术中(除麻醉诱导外)镇痛药的用量,并对患者伤口疼痛进行VAS评分。结果:对照组术中镇痛药(除麻醉诱导外)用量大于治疗组,但二者无统计学差异(P>0.05),术后伤口无痛者治疗组明显多于对照组,治疗组VAS评分显著低于对照组,差异有统计学意义(P<0.01)。结论:右美沙芬对于胆囊切除术有超前镇痛的作用,麻醉诱导前30 min肌注20mg,不仅可以减少术中镇痛药的用量,而且在更大程度上减轻了术后患者伤口的疼痛。     

乙烯雌酚对间情期比格犬发情的诱导

目的实验分析口服乙烯雌酚诱导间情期比格犬发情的效果,研究适合可行的比格犬诱导发情的方案。方法根据比格犬由间情期到发情期血清内雌二醇浓度逐步升高的变化规律,设计逐渐给实验犬增加口服乙烯雌酚的剂量,诱导比格犬发情;同时对照组给以恒定剂量的乙烯雌酚诱导发情;空白对照组给以淀粉片。结果实验组比格犬的诱导发情率为50%,怀孕率为25%;对照组的发情率为31.25%,怀孕率为18.75%;空白对照组的发情数为零。结论隔天给药,逐渐加量乙烯雌酚组诱导发情的效果明显好于隔天给药,恒定剂量组乙烯雌酚组诱导发情的效果。     

Involvement of retinoid X receptor alpha in coenzyme Q metabolism

The nuclear retinoid X receptor alpha (RXRalpha) is the heterodimer partner in several nuclear receptors, some of them regulating lipid biosynthesis. Since coenzyme Q (CoQ) levels are greatly modified in aging and a number of diseases, we have investigated the involvement of RXRalpha in the biosynthetic regulation of this lipid by using a hepatocyte-specific RXRalpha-deficient mouse strain (RXRalpha-def). In the receptor-deficient liver, the amount of CoQ decreased to half of the control, and it was demonstrated that this decrease was caused by a significantly lowered rate of biosynthesis. On the other hand, induction of CoQ was extensive in both control and RXRalpha-def liver using the peroxisomal inducer di(2-ethylhexyl)phthalate (DEHP). Since the RXRalpha deficiency was specific to liver, no change in CoQ content or biosynthesis was observed in kidney. The other mevalonate pathway lipids, cholesterol and dolichol, were unchanged in the RXRalpha-def liver. Upon treatment with DEHP, cholesterol decreased in the control but remained unchanged in the receptor-deficient mice. In control mice, cold exposure elevated CoQ levels by 60%, but this induction did not occur in the liver of RXRalpha-def mice. In contrast, PPARalpha-null mice, which lack induction upon treatment with peroxisomal inducers, respond to cold exposure and CoQ content is increased. The amount of cholesterol decreased in both control and RXRalpha-def liver upon cold treatment. The results demonstrate that RXRalpha is required for CoQ biosynthesis and for its induction upon cold treatment, but does not appear to be involved in the basic synthesis of cholesterol and dolichol. The receptor is not involved in the elevated CoQ biosynthesis during peroxisomal induction.