Highly purified agarose as stacking gel in sodium dodecyl sulphate/polyacrylamide-gel electrophoresis.

A modified sodium dodecyl sulphage/polyacrylamide-gel-electrophoretic method is described that utilizes highly purified agarose as stacking gel. The same electrophoretic resolution of different marker proteins is found as when polyacrylamide is used as stacking gel, but the background staining seen when polyacrylamide is used as stacking gel is decreased.     

The effect of the carbon source on ammonium regulation in Aspergillus nidulans

Summary Ammonium regulation of L-glutamate transport is annuled when L-glutamate is the sole or main carbon source. This shows that ammonium regulation mechanisms are not operative where the substrate of the ammonium repressible system can be used as a carbon as well as a nitrogen source. There is rapid loss of NADP L-glutamate dehydrogenase when glucose is replaced by L-glutamate as a carbon source. This suggests that NADP L-glutamate dehydrogenase may be subject to carbon as well as nitrogen control.     

Brain death and brain life: rethinking the connection

The connection between brain life and brain death is neither as simple nor as defensible as it might at first appear. The problem rests with the two dominant competing definitions of death:...the loss of that which is necessary for the organism to continue to function as a whole;....the loss of that which is essentially significant to the nature of the organism... If death is understood as the loss of that which is necessary for the continued functioning of the organism as whole, then the apparent symmetry breaks down. If...death could be understood as the loss of that which is essentially significant to the nature of the organism....consciousness, then the symmetry would hold. However, that definition of death is indefensible. Therefore...statements about the status of anencephalic infants and early human embryos based upon a connection between brain death and brain life are unfounded.     

An application of Berman's work on pool-model invariants in analyzing indistinguishable models for whole-body cholesterol metabolism

Berman and Schoenfeld used matrix transformations to study unidentifiable pool models. It is possible to use the method to examine if two models are output-indistinguishable, that is, if given the nature of tracer injections and observations, the two models have the same responses. The method is applied to two three-pool models for whole-body cholesterol metabolism. The indistinguishability of a mammillary model from a catenary model is proved using matrix transformations. The method is used in two ways, directly as well as after simplifying the problem. The two ways, as well as an analysis of the converse, help to show how the method is to be applied as well as the strengths and weaknesses of the method.     

Subunit composition and enzymatic properties of myosins from human and rabbit skeletal muscles

It is shown that myosin of human skeletal muscles is more difficult for purification from the actin and nucleic acids admixtures. It is also characterized by a less yield and a pronounced lability to denaturant effects as compared to rabbit myosin. The ATPase activity of human myosin is 1.5-2 times as low and the cholinesterase one--tens of times as high as those of rabbit myosin. A relative content of LC3 (LC--light chains) is approximately twice as low and that of LC1--as high as in rabbit myosin. It is supposed that the found differences in the properties may be explained to a considerable extent by a different ratio of certain light chains contained in the investigated proteins.     

Bone remodeling of diaphyseal surfaces by torsional loads: theoretical predictions

A theory of surface bone remodeling is extended to include the effects of shearing strains as well as normal strains. It is shown that the surface velocity can only depend upon the square of shearing strains, but that it can be linear as well as quadratic in the normal strains. The theory is applied to predict the surface bone remodeling in the diaphysis of a long bone under combined axial and torsional loading. In the general case the diaphysis of the long bone is modeled as a hollow thin-walled cylinder of arbitrary cross-section and, in a special case, as a right circular thin-walled tube. It is shown here that if a thin-walled right circular cylinder capable of surface remodeling is subjected to an axial compressive load and a twisting torque, then the effect of increasing the torque is the same as the effect of decreasing the axial compressive load, namely the mean radius of the cross-section increases and the wall width thins. Conversely, the effect of reducing the torque is the same as the effect of increasing the axial compressive load, namely the mean radius of the cross-section decreases and the wall width thickens.     

农牧结合生态工程的基本理论与实践

农牧结合生态工程是一个复杂的农业生态、经济和技术系统工程,它由植物(种植业)、动物(养殖业)和微生物(连接种养业)3个子系统组成,其关键是建设一个以"四、三、二、一"畜牧业生产模式为主要内容的高效节粮型畜牧生态工程,它要求用尽可能少的自然资源,在尽可能短的周期内,生产尽可能多而优的农(牧)产品,以获取尽可能高的经济效益,达到或维持尽可能最佳的生态平衡.     

Bone breaking stress as a function of weight bearing in bipedal rats

The effect of bipedal stance on the breaking stress in compression of rat femora is investigated as a function of animal weight. It is shown that the breaking stress is a linear function of body weight, bone density and specific calcium content of the femur. In all cases investigated, bipedal femora are shown to have a higher breaking stress than controls. It is concluded that there is a continuous change in the quality as well as the quantity of bone in the rat femur with age and that the increased strength of bone material found in bipedal animals compared to controls as well as large animals as compared to small ones, cannot be explained on the basis of bone mineral content alone.     

Recent advances on biological difructose anhydride III production using inulase II from inulin

Difructose anhydride III (DFA III), the smallest cyclic disaccharide, consists of two fructose residues. DFA III is a hydrolysate of inulin and is rarely found in nature. Industrial interest in DFA III as a low-calorie sugar substitute is increasing. The present review describes the properties and physiological functions of DFA III as well as its commercial importance. Focus is also given on the biological production of DFA III from inulin, which contains enzyme resources, inulase II properties, and the capacity for mass DFA III production. Inulase II as an industrial enzyme and its molecular evolution are discussed as well. The aim is to better understand commercial-scale DFA III production as a food product.     

中国小腹茧蜂属二新种记述(膜翅目,茧蜂科,小腹茧蜂亚科)

记述了采自黑龙江、吉林、辽宁和湖北省小腹茧蜂属M.icrogaster Latreille,18042新种,短管小腹茧蜂M.breviterebrae sp．nov．和长距小腹茧蜂M．longicalcar sp．nov．。短管小腹茧蜂M.breviterebrae sp．nov．(♀)与M．grandis相似,但以下特征可以区别：1)翅痣下方具暗斑(后者无);2)触角端前节长为宽的1．2倍(后者为2倍);3)头顶光滑(后者具皱纹);4)腹部第3背板光滑(后者具皱状刻点);5)后足胫节黑色(后者红黄色)。采自黑龙江镜泊湖、吉林长春、辽宁(阜新、大连、沈阳)。长距小腹茧蜂M．longicalcar sp．nov．(♀)与短管小腹茧蜂M.breviterebrae sp．nov．相似,但以下特征可以区别：1)1—RS脉长为1—M脉1／2(后者为1／3);2)r脉与翅痣宽等长(后者明显短于翅痣宽);3)后足胫节内距长为基跗节6／7(后者为1／2);4)产卵管鞘长为后足胫节1／2(后者为1／3);5)前后单眼间距与单眼直径等长(后者短于单眼直径)。采自湖北房县。本文附中国小腹茧蜂属分种检索表。模式标本均保存在浙江大学植保系寄生蜂标本室。     

On the taxonomy and distribution of the leaf-beetle <Emphasis Type="Italic">Macroplea japana</Emphasis> Jacoby, 1885 (Coleoptera,Chrysomelidae)

The species rank of Macroplea japana (Jacoby, 1885) is confirmed based on examination of the holotype. The main characters distinguishing this species from M. mutica are as following: the 4th antennomere is as long as the 3rd segment and somewhat longer than the 2nd segment; the pronotum is smooth, shining, with 3 black longitudinal stripes on the bottoms of 3 longitudinal impressions; the femora and tibiae black apically; the 1st metatarsomere is as long as the 2nd and the 3rd tarsomeres combined and is almost twice as long as the 2nd tarsomere; the claws bear no triangular projection near the bases; the aedeagus forms a shorter apical projection. Macroplea japana is found in Russia (Primorskii Territory) for the first time.     

Children as means and ends in large-scale medical research

This paper considers the often-expressed fear that medical research may use children merely as means, and not respect them as ends in themselves - especially insofar as they are deemed less able to consent than adults. The main focus is on large-scale genetic, socio-medical and epidemiological research. The theoretical starting point of the paper is that to be treated as an end in oneself is to be regarded as - and to act as - a participant in cooperative endeavours. This participatory status is certainly connected with individual authority to consent and dissent; and there is no doubt that consent plays an important role when adults participate in many research projects. However, insofar as consent is located within structures of human cooperation, the authority to consent is not a straightforward privilege. Rather, consent is bound up with responsibility for one's choices and commitment to shared terms of cooperation. Given this understanding, it is argued that consent should not be our principal concern when we involve children in research. This is not because of children's (possible) incompetence to consent as such, but rather because children are still learning how to respect and assess the cooperative terms involved in our institutional lives. Instead, our leading concern should be with the terms regulating their involvement in research. Given suitable safeguards, research is one way in which children may learn what it is to bear responsibilities and to act as an end in oneself - that is, to cooperate with others on reasonable terms and for worthy ends.     

Plant oils as feedstock alternatives to petroleum – A short survey of potential oil crop platforms

Our society is highly depending on petroleum for its activities. About 90% is used as an energy source for transportation and for generation of heat and electricity and the remaining as feedstocks in the chemical industry. However, petroleum is a finite source as well as causing several environmental problems such as rising carbon dioxide levels in the atmosphere. Petroleum therefore needs to be replaced by alternative and sustainable sources. Plant oils and oleochemicals derived from them represent such alternative sources, which can deliver a substantial part of what is needed to replace the petroleum used as feedstocks.     

Unbalanced transmethylation and the perturbation of the differentiated state leading to cancer

It is proposed that the perturbation of the differentiated state in cancer is related to alterations in DNA methylation as well as to alterations in methylation of other cellular molecules, leading to an imbalance in global cellular methylation. It is hypothesized that the global imbalance in methylation is reflected in the enhanced levels of transmethylation seen in many cancer cell types as well as in a number of undermethylated molecules.     

On-line infrared spectroscopy for bioprocess monitoring

One of the major aims of bioprocess engineering is the real-time monitoring of important process variables. This is the basis of precise process control and is essential for high productivity as well as the exact documentation of the overall production process. Infrared spectroscopy is a powerful analytical technique to analyze a wide variety of organic compounds. Thus, infrared sensors are ideal instruments for bioprocess monitoring. The sensors are non-invasive, have no time delay due to sensor response times, and have no influence on the bioprocess itself. No sampling is necessary, and several components can be analyzed simultaneously. In general, the direct monitoring of substrates, products, metabolites, as well as the biomass itself is possible. In this review article, insights are provided into the different applications of infrared spectroscopy for bioprocess monitoring and the complex data interpretation. Different analytical techniques are presented as well as example applications in different areas.     

Development of a novel fluorometric assay for nitric oxide utilizing sesamol and its application to analysis of nitric oxide‐releasing drugs

Nitric oxide (NO) is related to various physiological effects as well as to numerous diseases caused by accentuation of NO production. Measurement of NO in cells and tissues is difficult as NO readily reacts with other molecules; furthermore, its half‐life as a radical is fleeting. Currently, many NO pharmaceuticals are marketed as therapeutic agents for ischemic disease. Consequently, the identification of NO radicals and determination of generation rate from pharmaceuticals is very important when the effect of the medicinal supply is estimated. In this study, we developed a fluorometric assay for NO employing sesamol (3,4‐methylenedioxyphenol) as a fluorometric substrate. Sesamol is converted to a fluorescent derivative (ex. 365 nm, em. 447 nm), which is dimmer in the presence of NO. The detection limit of NO with this method is 400 fmol; moreover, NO generated from drugs can be measured. Copyright © 2009 John Wiley & Sons, Ltd.     

Optimal Tracking Controller Design for a Small Scale Helicopter

A model helicopter is more difficult to control than its full scale counterpart. This is due to its greater sensitivity to control inputs and disturbances as well as higher bandwidth of dynamics. This work is focused on designing practical tracking controller for a small scale helicopter following predefined trajectories. A tracking controller based on optimal control theory is synthesized as a part of the development of an autonomous helicopter. Some issues with regards to control constraints are addressed.The weighting between state tracking performance and control power expenditure is analyzed. Overall performance of the control design is evaluated based on its time domain histories of trajectories as well as control inputs.     

Contents of putrescine, spermidine and spermine in tissue of the human brain glial tumors

It is shown that in the tissue of the human brain glial tumours the content of putrescine depends on the degree of the tumour malignization. In malignant gliomas (glioblastomas), as compared to the benign (astrocytomas), the content of putrescine is significantly higher. The content of spermidine in glial tumours of a malignancy different degree is twice as high as the level of this polyamine in the brain grey matter, and it is twice as low as in the white matter. The content of spermine in the brain glial tumours does not differ essentially from its level in the brain tissue.     

Inhibition of cholinesterases by quaternary phosphonium compounds

Alkyl tributylphosphonium and triphenylphosphonium derivatives as well as tetraphenylphosphonium were first studied as inhibitors of acetylcholinesterase of human blood erythrocytes and butyrylcholinesterase of horse blood serum. The inhibition is reversible, of mixed type, with a different contribution of competitive and uncompetitive components. The value of the inhibitory effect is essentially dependent on the structure of phosphonium compounds, especially in experiments with butyrylcholinesterase: allyltriphenylphosphonium is 290 times as strong enzyme inhibitor as methyltributylphosphonium. Hexyltributylphosphonium is identical to hexyltributylammonium in both the pattern and efficiency of the inhibitory action on cholinesterases.     

巴西人参化学成分和药理活性研究进展

巴西人参原产于南美洲,当地人把它当做具有壮阳、增强体质等作用的草药。巴西人参已在我国广西、浙江等地引种栽培成功,现代研究发现,其主要含有三萜和三萜皂苷类、甾体类等多种化学成分,具有抗肿瘤、抗炎、保护胃黏膜等药理活性。本文通过对近年来巴西人参的研究情况进行综述,阐明已有的化学物质基础和药理作用,为其进一步的深入研究和开发提供理论依据。