相反相成药物治疗马骡结症的理论探讨

“对立统一规律是宇宙的根本规律。”动物体是完整统一的有机体,其各系统、各器官的机能活动是矛盾的,对立的,同时又是统一的。心脏的跳动,肺脏的呼吸,肌肉的伸缩,胃肠的蠕动等,都是由相互联系、相互制约的对立统一的活动完成的。在这些活动当中,神经系统起着主要的调节作用。中枢神经系统是支配全身活动的中枢,而内脏器官的活动是由相对自主的植     

云南一些植物特征成分与古夷平面的相关性

生理生态学的原则是随着纬度的升高,物种分布的海拔高度将随之降低。但是,云南一些植物特征成分的分布却与之相反,它们的分布与云南残留的古夷平面的分布相似,即随着纬度的升高,其分布的海拔高度也随之升高。二者的区别是云南古夷平面分布的趋势线的仰角大于那些特征成分分布的趋势线的仰角。可能的原因是：相对于剧烈的地质运动,物种的适应能力总是相对滞后的,并且物种的分布也受到其生长特性的制约;根据分布区形成的原则,这些成分的发生应早于夷平面的隆起。     

自然和热凝固的人肝组织对KTP/YAG激光的光学特性的比较研究

本文采用双积分球测量系统和Inverse Add ing-Doub ling方法,研究了自然和热凝固的人肝组织对532nm的KTP激光和1 064 nm的Nd:YAG激光的光学特性。结果表明:热凝固的人肝组织对532 nm的KTP激光的吸收系数较自然的肝组织的吸收系数增大了23.5%(P<0.05),热凝固的肝组织对1 064 nm的Nd:YAG激光的吸收系数较自然的肝组织的吸收系数减小了34.3%(P<0.05)。热凝固的人肝组织对532 nm的KTP激光的散射系数较自然的肝组织的散射系数增大了4.50倍(P<0.05),热凝固的肝组织对1 064 nm的Nd:YAG激光的散射系数较自然的肝组织的散射系数增大了6.41倍(P<0.05)。热凝固的人肝组织对532 nm的KTP激光的各向异性因子较自然的肝组织的各向异性因子减小了5.47%,热凝固的肝组织对1 064 nm的Nd:YAG激光的各向异性因子较自然的肝组织的各向异性因子减小了1.95%。     

学案导学在高中生物教学中的应用

制作学案的过程,就是老师理解通透所传授的知识的前提下,阅读大量的相关的资料,根据学生的认知水平与知识的积累能力,为指导学生进行主动的知识建构而编制的学习方案,以便积极引导和帮助学生的自主学习的能力进行探究思索的方案。高中生物的教学研究问题,通过学案的方式向学生传授知识,是教师在教学理论与学习标准的指导下对高中生物的教学所提高的一个新层次。     

植物保护与农业可持续发展关系探究

随着社会的发展经济的进步我国在各个领域的发展上都得到了相应的提升,从农业的发展情况来看,由于我国在科学技术上进步故此在农业的发展上也取得了重大的成效,但是在农业发展的过程中也出现了一些严重的问题,就是对于化学药品的使用所造成的农产品的污染以及环境的污染。本文主要针对当前的一些植物保护的现状进行阐述,并对植物保护和农业的可持续发展间的关系进行了详细的分析探究,希望能够在此领域的学术发展起到一定的参考作用。     

浅谈果树病虫害综合防治技术研究

在我国的农业生产的过程中,对于果树的病虫害综合防治是农业生产效益的根本保障,我国是一个农业大国,尤其是在我国的北方,果树的栽培更是有着悠久的历史,在近些年中由于技术的进步果树的品种更新的速度也在不断的加快,但是随之而来的就是果树的病虫害的问题,它对于果树的影响非常的大,直接在经济上给果农带来严重的损失,为了能够让果农的经济效益得到保障,对于果树的病虫害防治就显得极为重要。本文主要是对东北地区的果树病虫害的现状进行简要的分析,并对果树病虫害的综合防治技术进行研究找出适当的对策,希望能有所裨益。     

浅析如何做好基层林业站的工作

在当前的形势下,我国的林业建设工作也是需要及时的调整发展方案,以此来适应新时代的发展的,要由传统的林业建设模式逐渐的向现代化的方向发展。从某种程度上来说,基层林业站的微观变化也会对林业建设的发展方向的宏观调整产生直接的影响,因此,要结合科学发展的建设理念,来指导林业站的工作,以此来促进林业的健康建设。文章主要阐述基层林业站的作用,主要是为更好的发挥基层林业站的效用服务的。     

植物生理学研究与四化建设

一、植物生理学面临的挑战作为植物学的一个重要分支的植物生理学经过百余年的发展对植物生命活动的基本规律及其与环境的关系的了解取得了长足的进展,也对人类的生产活动起了巨大的促进作用。例如化学肥料及生长调节剂与除草剂的大规模应用,细胞全能性的发现及利用等。但与现代自然科学体系日新月异的进步相比植物生理学则象百舸竞渡中的一叶扁舟,面临着严峻的挑战。近年分子生物学和遗传学的飞速进步,各种物理化学检测手段的应用及检测精度的提高,使植物生理学的机理的探索必须建立在分子生物学的基础上并相应地使用精确的检测手段,例如植物激素乙烯的发现及其生物合成与作用机理的研究,就是建     

探讨中日环境管理存在的差异以及解决对策

环境状况的好与坏通常决定着一个国家的综合国力的强与弱。近几年来,随着社会的发展,环境方面的问题越来越多,各个国家对于环境问题的解决方法以及管理方式各有千秋,同时各个国家对于环境问题的管理也都十分的重视。而其中,日本环境的管理是开始于20世纪中期的,从20世纪中期到现在,短短的这一段时间中,日本的环境管理出现出人意料的成功,不仅创造了防治产业污染的奇迹,同时也形成了一套相对完成的管理体制以及丰富多彩的管理模式。与日本不同的是,我国的环境管理方面尚且存在一定的问题。本文将结合中日环境管理方面存在的差异探讨中国的环境管理存在的问题的解决对策。     

正常微生物群是一个新的人体生理学系统

1　前言微生态学的发展 ,现在已把微生物的作用 ,从主要是致病作用的观点转移到主要是生理作用的观点。这种观点的转变是经过 10 0多年的学术研究和科学发展才取得的。在 2 0世纪经过无菌动物的饲养、厌氧培养技术的进步和现代分子生物学、基因工程学的研究终于完成了微生态学向新的更高阶段的转变。这就是微生物的研究以致病性为主的时代转向以生理性为主的时代。要确定一门新学科的诞生日期是很难的。一门新学科的定义也是逐渐形成的 ,要经过科研成果不断积累才能逐渐完善。正常微生物群的生理作用的提出是很早的 ,至少要推衍到 19世纪的…     

壳聚糖酶的克隆表达与壳寡糖的制备分析

目的:克隆壳聚糖酶基因于大肠杆菌中实现高表达,制备壳寡糖。方法:以枯草芽孢杆菌总DNA为模板扩增壳聚糖酶基因(CSN),克隆至载体pET23a(+)上,转化菌株BL21(DE3)。重组子经0.5 mmol/L IPTG诱导后,SDS-PAGE和质谱检测与鉴定重组酶。酶纯化后水解壳聚糖,薄层色谱分析其水解产物。结果:质谱证明壳聚糖酶(31.5kDa)成功表达,表达量占菌体总蛋白的45%左右。纯化后重组酶浓度为900 mg/L,纯度95%、回收率85%,酶活力为10 000 U/mg。壳聚糖降解产物为壳二糖至壳四糖。结论:原核表达载体pET23a(+)-CSN构建正确,壳聚糖酶表达量与活性高,适用于水解壳聚糖制备壳寡糖。     

国内外蝗害治理技术现状与展望

本文首先概述了国内外蝗虫发生与为害的态势,总结了现阶段我国蝗虫发生与为害的主要特点:即农田飞蝗暴发频繁而且严重,草原土蝗的发生时常造成严重的经济损失,而且侵入城市干扰市民生活,我国与周边国家之间蝗虫过境迁移频繁,使用化学农药污染环境和农产品;分析了国内外蝗虫防治对策与技术的发展现状,重点介绍了应急防治和可持续治理对策、...     

Synthesis and turnover of cerebrosides and phosphatidylserine of myelin and microsomal fractions of adult and developing rat brain.

The synthesis and turnover of cerebrosides and phospholipids was followed in microsomal and myelin fractions of developing and adult rat brains after an intracerebral injection of [U-14C]serine. The kinetics of incorporation of radioactivity into microsomal and myelin cerebrosides indicate the possibility of a precursor-product relationship between cerebrosides of these membranes. The specific radioactivity of myelin cerebrosides was corrected for the deposition of newly formed cerebrosides in myelin. Multiphasic curves were obtained for the decline in specific radioactivity of myelin and microsomal cerebrosides, suggesting different cerebroside pools in these membranes. The half-life of the fast turning-over pool of cerebrosides of myelin was 7 and 22 days for the developing and adult rat brain respectively. The half-life of the slowly turning-over pool of myelin cerebrosides was about 145 days for both groups of animals. The half-life of the rapidly turning-over microsomal cerebrosides was calculated to be 20 and 40 h for the developing and adult animals respectively. The half-life of the intermediate and slowly turning-over microsomal cerebrosides was 11 and 60 days respectively, for both groups of animals. The amount of incorporation of radioactivity into microsomal cerebrosides from L-serine was greatly decreased in the adult animals, and greater amounts of the precursor were directed towards the synthesis of phosphatidylserine. In the developing animals, considerable amounts of cerebrosides were synthesized from L-serine, besides phosphatidylserine. The time-course of incorporation indicated that a precursor-product relationship exists between microsomal and myelin phosphatidylserine. The half-life of microsomal phosphatidylserine was calculated to be about 8 h for the fast turning-over pool in both groups of animals.     

Molecular characterisation of species and genotypes of Cryptosporidium and Giardia and assessment of zoonotic transmission

The molecular characterisation of species and genotypes of Cryptosporidium and Giardia is essential for accurately identifying organisms and assessing zoonotic transmission. Results of recent molecular epidemiological studies strongly suggest that zoonotic transmission plays an important role in cryptosporidiosis epidemiology. In such cases the most prevalent zoonotic species is Cryptosporidium parvum. Genotyping and subtyping data suggest that zoonotic transmission is not as prevalent in the epidemiology of giardiasis. Molecular characterisation of Cryptosporidium and Giardia is a relatively recent application that is evolving as new genes are found that increase the accuracy of identification while discovering a greater diversity of species and yet unnamed taxa within these two important genera. As molecular data accumulate, our understanding of the role of zoonotic transmission in epidemiology and clinical manifestations is becoming clearer.     

Identification and composition of the tonsillar and anal enterococcal and streptococcal flora of dogs and cats

Enterococcus faecalis was the most frequently isolated enterococcal species from anal swabs and tonsils of dogs and cats, although in the anal samples from dogs Ent. hirae was found almost as often as Ent. faecalis. Most Ent.faecium strains from dog tonsils differed from those associated with humans and other animals in that they fermented sorbitol. Typical Ent. avium as well as atypical Ent. avium -like strains were seen in dogs, while the related species Ent. raffinosus was associated with cat tonsils. Enterococcus cecorum also occurred mainly in cats. Certain atypical strains, presumptively identified as Ent. cecorum , shared characteristics with Ent. columbae.
The most frequent streptococcal species in tonsils of cats and dogs were Streptococcus suis and Strep. canis. Streptococcus canis and Strep. bovis predominated in anal swabs. The canine Strep. suis differed from the common porcine strains in fermenting mannitol.
Forty-seven of the 288 isolates examined could not be identified or related to known species. The characteristics of two groups of these bacteria, provisionally called 'Ton 31 group' and 'O7 group' are described.     

Coiled-coil nanomechanics and uncoiling and unfolding of the superhelix and alpha-helices of myosin

The nanomechanical properties of the coiled-coils of myosin are fundamentally important in understanding muscle assembly and contraction. Force spectra of single molecules of double-headed myosin, single-headed myosin, and coiled-coil tail fragments were acquired with an atomic force microscope and displayed characteristic triphasic force-distance responses to stretch: a rise phase (R) and a plateau phase (P) and an exponential phase (E). The R and P phases arise mainly from the stretching of the coiled-coils, with the hinge region being the main contributor to the rise phase at low force. Only the E phase was analyzable by the worm-like chain model of polymer elasticity. Restrained molecular mechanics simulations on an existing x-ray structure of scallop S2 yielded force spectra with either two or three phases, depending on the mode of stretch. It revealed that coiled-coil chains separate completely near the end of the P phase and the stretching of the unfolded chains gives rise to the E phase. Extensive conformational searching yielded a P phase force near 40 pN that agreed well with the experimental value. We suggest that the flexible and elastic S2 region, particularly the hinge region, may undergo force-induced unfolding and extend reversibly during actomyosin powerstroke.     

Separation of outer and cytoplasmic membranes of Fibrobacter succinogenes and membrane and glycogen granule locations of glycanases and cellobiase.

The outer membrane (OM) of Fibrobacter succinogenes was isolated by a combination of salt, sucrose, and water washes from whole cells grown on either glucose or cellulose. The cytoplasmic membrane (CM) was isolated from OM-depleted cells after disruption with a French press. The OM and membrane vesicles isolated from the extracellular culture fluid of cellulose-grown cells had a higher density, much lower succinate dehydrogenase activity, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis protein profiles different from those of the CM. The OM from both glucose- and cellulose-grown cells and the extracellular membrane vesicles from cellulose-grown cultures exhibited higher endoglucanase, xylanase, and acetylesterase activities than the CM and other cell fractions. Endoglucanase 2 was absent from the isolated OM fractions of glucose- and cellulose-grown cells and from the extracellular membrane vesicles of cellulose-grown cells but was present in the CM and intracellular glycogen granule fractions, while endoglucanase 3 was enriched in the OM. Cellobiosidase was located primarily in the periplasm as previously reported, while cellobiase was mainly present in the glycogen granule fraction of glucose-grown cells and in a nongranular glycogen and CM complex in cellulose-grown cells. The cellobiase was not eluted from glycogen granules by cellobiose, maltose, and maltotriose nor from either the granules or the cell membranes by nondenaturing detergents but was eluted from both glycogen granules and cell membranes by high concentrations of salts. The eluted cellobiase rebound almost quantitatively when diluted and mixed with purified glycogen granules but exhibited a low affinity for Avicel cellulose. Thus, we have documented a method for isolation of OM from F. succinogenes, identified the OM origin of the extracellular membrane vesicles, and located glycanases and cellobiase in membrane and glycogen fractions.     

Asymmetry of cilia and of mice and men.

Evidence is given for the opinion that cilia in the early embryo, by their work, determine the laterality of the body; without ciliary work body laterality would be randomized. More exactly, monocilia in the primitive node are responsible for this determination. They have been described as being of the 9+0 type, but with dynein arms and with a gyrating movement. The orientation of the monocilia on the epithelium is of no importance but the direction of their gyration is, as may also be the shape of the node. The chirality of the cilia is thus reflected directly in the asymmetry of the body. The dynein arms go clockwise as seen from the base to tip and the ciliary rotation is in the same direction. The resulting waterflow is towards the left and so is the movement of the forming heart. In most subgroups of the immotile-cilia syndrome this mechanism does not work and equally many individuals will be born with situs inversus as with situs solitus. An exception is the immotile-cilia subgroup, named 'microtubule transposition', which is characterized by all cilia having a 9+0 structure throughout most of their length.     

Carnitine and creatine content of tissues of normal and alloxan-diabetic sheep and rats

The concentration of carnitine in liver increased 28-fold and urinary carnitine excretion 5-fold in alloxan-diabetic sheep. In contrast there were no similar increases in alloxan-diabetic rats. The creatine content of liver decreased 3-fold and creatine excretion decreased 2-fold in diabetic sheep. In contrast the creatine content of liver increased nearly 4-fold in diabetic rats with no change in creatine excretion. The marked increased in production of carnitine by the liver of the diabetic sheep appears possible because of decreased production and excretion of creatine.     

Comparison of BMI and percentage of body fat of Indian and German children and adolescents

Today, serious health problems as overweight and obesity are not just constricted to the developed world, but also increase in the developing countries (Prentice 2006, Ramachandram et al. 2002). Focusing on this issue, BMI and percentage of body fat were compared in 2094 schoolchildren from two cross-sectional studies from India and Germany investigated in 2008 and 2009. The German children are in all age groups significantly taller, whereas the Indian children show higher values in BMI (e.g. 12 years: Indian: around 22 kg/m2; German: around 19 kg/m2) and in the percentage of body fat (e.g. 12 years: Indian: around 27%; German: around 18-20%) in most of the investigated age groups. The Indian children have significantly higher BMI between 10 and 13 (boys) respectively 14 years (girls). Indian children showed significant higher percentage of body fat between 10 and 15 years (boys) and between 8 and 16 years (girls). The difference in overweight between Indian and German children was strongest at 11 (boys) and 12 (girls) years: 70% of the Indian but 20% of the German children were classified as overweight. In countries such as India that undergo nutritional transition, a rapid increase in obesity and overweight is observed. In contrast to the industrialized countries, the risk of overweight in developing countries is associated with high socioeconomic status. Other reasons of the rapid increase of overweight in the developing countries caused by different environmental or genetic factors are discussed.