新冠疫情下“细胞生物学”课程思政教学研究

立德树人是教育事业的根本任务,课程思政是将立德树人融入教育各环节、各领域的重要手段。"细胞生物学"既是现代生命科学的前沿分支学科之一,也是高校生命科学类专业的重要课程。该文在课程思政的背景下,选择新型冠状病毒肺炎疫情(简称:新冠疫情)为载体,以"细胞生物学"课程中"病毒的特征、入侵、增殖"为主线,从"教学内容的甄选"和"实施策略"两个方面着手,开展聚焦新冠疫情下"细胞生物学"课程思政教学的深入探讨。该研究旨在引导学生在研习专业知识的基础上,提升其科学素养、树立其正确的价值观,为侧重新冠疫情的课程思政研究提供重要参考。     

Quantitative determination of the three-dimensional appearances of a rotating ellipse without a rigidity assumption

When a flat figure of uniform color and with an elliptic contour is slowly rotated around an axis orthogonal to the plane of the image, an observer set in the frontal position will perceive it first as a rotating ellipse. After a few seconds of inspection, the ellipse appears to deform with an amoeba-like movement until it appears as a rigid, circular disk tilting back and forth in 3-D space; finally it is seen as a rotating ellipsoid tilted in depth at a constant inclination angle with respect to the rotating platform. In an attempt to provide an explanation for the apparent ellipsoid, the authors present a mathematical model based on an hypothesis of velocity differences minimization, successfully used to describe other stereokinetic phenomena, such as the rotating cone and the tilted bar. This technique does not make use of Ullman's ridigity hypothesis for extracting depth from 2-D moving stimuli. A comparison with experimental results supports the validity of the model.     

Morphological stabilization of the glycocalyces of 23 strains of five Bacteroides species using specific antisera

Cells of five Bacteroides species were examined following treatment with homologous antisera and staining with ruthenium red. They were enveloped by glycocalyces and these extensive fibrous exopolysaccharide matrices were fully retained as an integral "capsule" by some cells, while other cells showed "capsule" as well as detached glycocalyx components forming an intercellular "slime.". These extensive glycocalyces collapsed during dehydration for electron microscopy and formed electron-dense accretions on cell surfaces and electron-dense reticula in intercellular spaces when the cells were treated with heterologous antiserum or when antibody stabilization was omitted. The glycocalyces of all strains, both stabilized and unstabilized, were observed outside the outer membranes of cell walls that showed the "classic" gram-negative structural organization. Appropriate modifications of the indirect fluorescent antibody test demonstrated an integral "capsule" on all strains examined; detached glycocalyx and varying amounts of slime were demonstrated after stabilization with homologous, but not heterologous, antiserum.     

Differential coupling efficiency of chemically activated amino acid to tRNA

Summary Interaction based on possible chemical affinity of an amino acid for tRNA was examined as a model for the aminoacylation of primitive tRNA without aid of an enzyme system. Two types of reaction were carried out and compared. One was the acyl linkage of amino acid to the 5-terminal phosphate of a tRNA activated as an imidazolide. The other was the incorporation of an amino acid activated as an imidazolide into 2(3)-hydroxyl groups of intact tRNA. Both types of reaction indicated that none of the amino acids tested had any selectivity for the tRNAs examined. However, the rates of reaction with a given tRNA were different among amino acids. In the second type of reaction, amino acids were found mainly at loop-out regions of tRNA, but not at either its 5- or 3-terminal sitesOneA ₂₆₀ unit is defined as an amount of material which gives an absorption of 1.0 at 260 nm when dissolved in 1 ml water and measured with a 1-cm light path     

Definition of the concept "information" and prospects of its use in biology

It is suggested to define the concept "information" as a "guide to action",--as a sum of methods, rules and data necessary for constructing an operator which should ensure an increase in the probability of occurrence of some event called a "goal" in the initial situation. The main properties of information, the possibility of estimating its volume, value and efficiency, as well as the problems related to information dynamics are considered. Some prospects of using the formulated concepts in biology are discussed.     

The embryo as allograft

The main problems and experimental results with respect to the mechanism by which the embryo, as "allograft", is tolerated within the maternal organism are reviewed. The following hypotheses are discussed: the immunological "immaturity" of the embryo and of its appendages; the immunological incompetence of the maternal organism; the uterus as an immunologically "privileged" area; the existence of an immunological barrier between the mother and the embryo.     

肺与大肠相表里的微生态学解释

“肺与大肠相表里”、“肺在志为悲（忧）”均是传统中医所特有的思维,现代临床实践也发现肠道疾病与肺部疾病常相伴而发,而情志失调常为肺肠疾病的诱因。但没有物质基础的经脉如何联系肺与肠,用经脉络属或是五行理论来解释的“肺在志为悲（忧）”观点有没有明确的物质基础仍有待研究。目前各项研究发现肺与大肠在解剖及生理病理过程方面存在相似性,而菌群在肺—肠联系中起着重要的作用,很可能是经脉联系肺肠的物质基础之一,随着对肠道菌群研究的进一步深入,其与抑郁症等情志障碍疾病的潜在关系被逐渐揭示,也让“肺在志为悲（忧）”的观点获得认同和深化,借助最新研究成果深度认识理论术语与客观实在的关系,是中医发展的必由之路。     

Non-equivalent interactions between amino-terminal domains of neighboring lambda integrase protomers direct Holliday junction resolution

The bacteriophage lambda site-specific recombinase (Int), in contrast to other family members such as Cre and Flp, has an amino-terminal domain that binds "arm-type" DNA sequences different and distant from those involved in strand exchange. This defining feature of the heterobivalent recombinases confers a directionality and regulation that is unique among all recombination pathways. We show that the amino-terminal domain is not a simple "accessory" element, as originally thought, but rather is incorporated into the core of the recombination mechanism, where it is well positioned to exert its profound effects. The results reveal an unexpected pattern of intermolecular interactions between the amino-terminal domain of one protomer and the linker region of its neighbor within the tetrameric Int complex and provide insights into those features distinguishing an "active" from an "inactive" pair of Ints during Holliday junction resolution.     

Kinematics of metachronous walking. II. Gaits]

For an arbitrary locomotory system three ways of gait classification are considered and compared. A general classification is represented as an "abstract scheme" of phase-space separation of the locomotory system. The "configurational scheme" is the result of methachronal coordination postulate, and the "footprint scheme" is the result of the postulating of special properties of the footprint track.     

Contribution to the mechanics of worm-like motion systems and artificial muscles

In this paper the author presents a mathematical model of a device that can be seen as a segment of an artificial worm (following the paradigm earthworm) and as an artificial muscle as well. Confining considerations to statics, the model shows up as an ordinary parameter-dependent boundary value problem. It is tackled numerically in various particular forms by means of Maple and thus gives a good view of the segment's behavior during inflation and under longitudinal load. Segments of maximal volume present a useful preliminary stage of the investigations.Thanks are to Klaus Zimmermann and his Motion Systems Group at TU Ilmenau for discussions and experiments, to Katrin Knabe for typing, and to an unknown reviewer for directing the author's attention to physical nonlinearity.     

EMG biofeedback of the abductor pollicis brevis in piano performance

The aim of the present study was to apply EMG biofeedback as an auxiliary to piano teaching techniques. We studied the changes in integrated electromyographic activity, using the abductor pollicis brevis functioning as an agonist during the teaching of identical selective movements of piano playing in two groups, one with EMG biofeedback and the other following traditional method of instruction. The analysis of variance revealed an increase in the peak amplitude and the relaxation rate values for the biofeedback group. These results have implications for the application of piano playing techniques and reveal EMG biofeedback as an aid in the teaching of thumb attack with the abductor pollicis brevis as agonist.We are grateful for the valuable assistance of Dr. Jaime Vila (Professor of Therapy and Behavioral Modification, Faculty of Psychology, Granada), the cooperation of students at the Juventudes Musicales Music School, Santa Fe and at the Victoria Eugenia Conservatoire, (Granada), the Statistical Analysis Centre of University of Filosofia y Letras de Granada; Professor Enrique Garcia Fernandez-Abasal (Complutense University) for the design of the interface and software.     

Terminology for contractions of muscles during shortening, while isometric, and during lengthening.

Communication among scientists must be clear and concise to avoid ambiguity and misinterpretations. The selection of words must be based on accepted definitions. The fields of biomechanics, muscle physiology, and exercise science have had a particularly difficult time with terminology, arising from the complexity of muscle contractions and by the use of inappropriate terminology by scientists. The dictionary definition of the verb "contract," specifically for the case of muscle, is "to undergo an increase in tension, or force, and become shorter." Under all circumstances, an activated muscle generates force, but an activated muscle generating force does not invariably shorten! During the 1920s and 1930s, investigators recognized that the interaction between the force generated by the muscle and the load on the muscle results in either shortening, no length change (isometric), or lengthening of the muscle. The recognition that muscles perform three different types of "contractions" required that contraction be redefined as "to undergo activation and generate force." Modifiers of contraction are then needed to clarify the lack of movement or the directionality of movement. Despite the contradiction, for 75 years the lack of movement has been termed an "isometric contraction." The directionality of the movement is then best described by the adjectives "shortening" and "lengthening." The definitions of "concentric" as "having the same center" and of "eccentric" as "not having the same center" are consistent with hypertrophy, or remodeling of the heart muscle, but are inappropriate to describe the contractions of skeletal muscles.     

Expression of foreign genes in mammalian cells using an antibody fusion system

An expression system is described whereby a gene product is expressed fused to an antibody Fab fragment to form an antibody-like molecule The antigen binding function of the original antibody is retained and the foreign gene replaces the C_H2 and C_H3 regions of the heavy chain. The fusion protein is secreted as if it were an antibody, and can be purified using the antigen-binding function of the Fab-Iike part of the molecule. In principle any open reading frame can be expressed and it is not necessary to develop an individual purification scheme, or any analytical reagents such as antibodies, for the expressed protein, as both these functions can be performed by the Fab part of the fusion protein. In practice, the nature of the nonantibodv part of the fusion influences the efficiency of expression and secretion, and detailed guidance is given on trouble-shooting and maximizing expression.     

Development of the intestines. Human embryos]

In the present study an attempt was made to think over anew the development of the peritoneal situs, guided by the comparison of the "root-area" (the connective tissue area free of peritoneum between the left and right transition line of the peritoneum parietale to the peritoneum viscerale) of the so-called "primitive mesentery" of an embryo (10 mm CRL) and of an older fetus (250 mm CRL). The following results were obtained: The so-called primitive sagittal mesentery cannot be regarded as the anlage of the adult mesentery, in the sense that the latter develops out of the former dy displacement of rotation. The original "root area" widens with the broadening of the back and can still be demonstrated as an homogeneous "root area" of the "intestinal bulge", after the typical adult situs has developed. There is a connection between the development of the mesenteries and the formation of the folds of the embryonic serosa. Their position is determined through the recesses of the intestinal bulge. They exist because of the foldings and are therefore secondary characteristics. Under these aspects it is possible to consider the development of the situs as a uniform folding process of the embryonic serosa, without references to as yet unproved secondary adhesions of the peritoneal layers.     

论害虫种群的生态控制

本文根据保护生物圈与经济持续发展的要求,提出害虫种群的“生态控制’对策,以代替现在国内外采用的“综合防治”。文中根据生态学与经济学理论,不仅提出了“生态控制”应遵循的经济学与生态学的管理原则,并且提出了“生态控制”的指导思想与方法论,以及它的目标函数、约束条件与主要对策。进而根据国内外本领域的科技发展动态分析与生产实际需要,论述了本种对策在生产中的可行性与重要性。     

β-Xylanase produced by Aureobasidium pullulans CBS 58475

Summary Aureobasidium pullulans CBS 58475 produced -xylanase with an activity of 5 units/ml culture filtrate. Xylose, xylan and complex substrates containing xylose served as strong inducers. Purification of the enzyme was achieved by two sets of gel permeation chromatography. The enzyme has an pH optimum at 4.25 and a temperature optimum at 60°C. At slightly acid pH and temperatures up to 60°C -xylanase showed good stability. The analysis of cleavage products classified the -xylanase as an endoenzyme. Together with an endopolygalacturonase, the -xylanase enhanced the maceration of carrots compared to endopolygalacturonase alone.     

Longitudinal Distortions and Transversal Fluctuations of an Actin Filament Sliding on Myosin Molecules

An actin filament sliding on myosin moleculesdemonstrates both longitudinal distortions and transversal fluctuationswith the linear dimension far exceeding the diameter of an actinmonomer. Local swaying of a single actin filament was identified byreading speckled fluorescent markers attached on the filament. Theaccuracy of reading each speckled marker was about 10.4 nm (r.m.s.).Longitudinal distortions of an actin filament at a low ATP concentrationof 20 M were as much as 0.5 m for the average filament lengthof 5.4 m. The magnitude of transversal fluctuations was as much as60 nm, that was independent of the filament length. Both longitudinaldistortions and transversal fluctuations are suggested to play a pivotalrole for facilitating a smooth sliding movement of an actin filament.     

The determination of aluminium in soil,ash and plant materials using Eriochrome Cyanine R.A.

Summary A method for the determination of microgram quantities of aluminium using Eriochrome Cyanine R. has been modified for use with plant and soil extracts. The effects of pH, time, and order of addition of the reagents are clarified, and the use of an iron blank in conjunction with sodium thioglycollate as an iron inhibitor is elaborated.In addition to being rapid and reliable, the method is approximately twice as sensitive as the standard Aluminon method.     

Transmission and scanning electron-microscopic observations on tanycytes in the mediobasal hypothalamus and the median eminence of adrenalectomized rats

Summary Tanycytes in the median eminence (ME) of the rat exhibit morphological features suggesting their possible participation in transport phenomena. After adrenalectomy, which modifies the hypothalamo-hypophyseal axis, they undergo morphological changes characterized by an accumulation of lipid droplets, an increased number of bleb-like protrusions at their apex, as well as an increased pinocytosis of intraventricularly injected horseradish peroxidase (HRP). In addition, after adrenalectomy an increased number of vacuoles appears at the level of the tubero-infundibular sulci. Their intracellular location in the tanycytes is demonstrated by an intraventricular injection of HRP. The significance of these vacuoles is discussed in relation to the hydroelectrolytic modifications associated with the state of adrenalectomy.Supported by a Fonds Lekime-Ropsy AwardSupported by grants: 20472 from the Fonds de la Recherche Scientifique Médicale; and 40025 from the Fonds National de la Recherche Scientifique     

Embedding a grammatical description in deterministic chaos: an experiment in recurrent neural learning

We consider the modeling process of a biological agent by combining the concepts of neuroinformatics and deterministic chaos. We assume that an agent observes a target process as a stochastic symbolic process, which is restricted by grammatical constraints. Our main hypothesis is that an agent would learn the target model by reconstructing an equivalent quasi-stochastic process on its deterministic neural dynamics. We employed a recurrent neural network (RNN), which is regarded as an adjustable deterministic dynamical system. Then, we conducted an experiment to observe how the RNN learns to reconstruct the target process, represented by a stochastic finite state machine in the simulation. The result revealed the capability of the RNN to evolve, by means of learning, toward chaos, which is able to mimic a target's stochastic process. We precisely analyzed the evolutionary process as well as the internal representation of the neural dynamics obtained. This analysis enabled us to clarify an interesting mechanism of the self-organization of chaos by means of neural learning, and also showed how grammar can be embedded in the evolved deterministic chaos.