似哺乳类爬行动物和哺乳类动物脑颅侧壁构造类型的演替

本文对从原始似哺乳爬行动物进化到高级兽类哺乳动物过程中脑颅侧壁所发生的形态演化进行了分析,根据构造上的不同,将这些动物的脑颅侧壁的构造方式划分为四个构造类型,代表四个进化阶段。     

Functional outline of the epidemic process

The present study has shown that on the level of the parasitic system the epidemic process is a biological system, wherein the host population serves as the internal regulator, the mechanism of transmission serves as the external regulator and the parasite population, as the regulated object. The biological regulating mechanisms of the epidemic process have fundamental differences in the groups of infectious with various mechanisms of transmission, and the specific nature of the mechanism of transmission determines the peculiar features of the biological mechanism which governs the self-regulation of the epidemic process. In contrast, on a higher level of the organization of the epidemic process, i. e. on the level of the socio-ecological system, the epidemic process is a biosocial system, wherein the human society serves as the regulator, the parasitic system serves as the regulated object and the mechanism of transmission plays the role of the filter which determines the scope of social factors, most important in the regulation of the epidemic process in a given infection. The spontaneous regulation of the epidemic process is the freed forward channel from the regulator to the regulated object, and the controlled regulation is the feedback channel.     

庞泉沟保护区核心区植被景观类型特征研究

利用植被景观类型图,获得面积、周长、景观斑块的长、宽等信息,对庞泉沟保护区核心区的植被景观特征进行分析。结果表明,核心区景观及斑块分布具有明显的地带性;核心区景观多样性较小,均匀度较低。另外,本文尝试用长宽比、伸张度、圆环度和周长与长轴的比这四种指数对景观斑块的特征进行了分析。结果表明,这四种指数在景观特征分析中具有一定的生态学意义。     

A mechanism of formation of protein-free regions in the red cell membrane: the rupture of the membrane skeleton

The process of rupture and redistribution of the red cell membrane skeleton is analyzed theoretically. Following the emergence of the rupture the spectrin-actin network is redistributed on the cytoplasmic surface of the membrane bilayer. Due to the interaction of the membrane skeleton and integral proteins the redistribution of the spectrin-actin network leads to the release of purely lipid regions of the membrane. The scale of the protein redistribution caused by the rupture of the membrane skeleton and the size of the lipid domains produced depend on the shape of the membrane and the value of the electrical interaction of the membrane proteins. The lipid domains occurring as a result of the rupture and relaxation of the spectrinactin network can spontaneously increase or decrease its area. The criteria determining the conditions which result in the system's evolutions leading to the domain growth have been obtained. The character of the evolution is determined by the shape of the membrane region in which the rupture occurs as well as the relation between the effective linear tension of the rupture boundary and the modulus of elasticity of the spectrin-actin network.     

脑室内注入TRH对大鼠肝胆生化影响机理的研究

在大鼠的脑室内注入ＴＲＨ（三肽酰胺）,观察其对大鼠肝胆汁分泌的影响．实验结果表明,侧脑室内注入ＴＲＨ对胆汁分泌量有明显的增强作用,并且随ＴＲＨ剂量加大其作用逐渐增强．而且在侧脑室内注入ＴＲＨ期间,胆汁中Ｋ＋、Ｃｌ－、Ｎａ＋、ＨＣＯ３－离子的排出量亦有增加．其机理在于,侧脑室内注入ＴＲＨ,激活中枢胆碱能系统,并通过送走神经而使肝的新陈代谢发生变化．     

纵坑切梢小蠹蛀梢期空间分布

在昆明地区,纵坑切梢小蠹(Tomicus piniperda)成虫蛀梢多集中在蛀干木附近。 种群密度以蛀干木为中心向周围呈指数递减,散布半径约30m。在蛀梢过程中,该种群逐渐向新区扩张。在树冠内,纵坑切梢小蠹主要分布在4-10轮枝上。第7轮枝虫口百分率最高。6-7轮枝受害率最大。 树冠上层受害较其下层严重。从树冠水平层次考察,树冠外层虫量相对集中,约为树冠中、内层虫量之和。 树冠内层虫量最少。纵坑切梢小蠹在树冠内的种群分布系由梢径、种群密度、蛀梢行为、降落方式、光照等因素综合影响的结果。     

A localized zone of increased conductance progresses over the surface of the sea urchin egg during fertilization

Although activation of a sea urchin egg by sperm leads to three phases of membrane conductance increase in the egg, the mechanism by which the sperm causes these conductance changes is not known. We used the loose patch clamp technique to localize the conductance changes in voltage clamped eggs. A patch of the egg's membrane was isolated from the bath by pressing the loose patch clamp pipette against the egg surface. Sperm added to the bath attached to the surface of the egg in a region other than at the isolated membrane patch. During phase 1 of the activation current, no changes of the membrane conductance were detected. At the time of, and subsequent to the onset of phase 2, large currents recorded between the interior of the patch pipette and the bath were attributed to changes of the seal resistance between the surface of the egg and the pipette. A local change of membrane conductance was observed during phase 2 despite the changes of seal resistance. During phase 2, the large amplitude and short duration of the local membrane conductance increase relative to the membrane, conductance increase for the whole egg during phase 2 indicated that the conductance increase occurred over the entire surface of the egg, but not simultaneously. The time when the peak conductance for the membrane patch occurred, relative to the time of onset for phase 2 in the whole egg, depended on the distance, measured in a straight line, between the site of sperm attachment and the tip of the pipette. These data indicate that the localized conductance increase progressed over the surface of the egg from the site of sperm attachment to the opposite pole of the egg. It is proposed that the local conductance increase, the cortical reaction, and the change of seal resistance are all evoked by a common cytoplasmic message that progresses throughout the cytoplasm of the egg from the site of sperm attachment to the opposite pole of the egg.     

Simulating the response of a standing operator to vibration stress by means of a biomechanical model

Under vibration stress the compressive forces transmitted in the joints of a standing operator are composed of nearly static and oscillating force parts. Because these forces can hardly be measured they were assessed by means of a biomechanical model. In the model, 27 rigid bodies with 103 degrees of freedom represent the segments of the human body. 106 force elements imitate the muscles of the trunk and the legs. At first, the model parameter were varied so that for the simulated sitting posture the model fits the seat-to-head transmissibility given in the literature and in ISO/CD 5982. For the standing posture, the transfer functions between the ground acceleration and the oscillating forces in the ankle, the knee, the hip, and the motion segment L3-L4 were computed. According to the moduli of these functions the forces in the ankles are higher than those in the knees or the hips and they nearly come up to the forces in the lumbar spine. Further the results of the simulation indicate that under equal vibration stress in the standing and the sitting posture the differences between the compressive forces in the lumbar spine are small.     

采用OCT系统对组织光学通透的研究

组织通透方法采用高折射率化学试剂对生物组织进行渗透,改变组织的光学均匀性,可以有效地改善光学成像的穿透深度,受到生物医学光学研究领域的重视。利用光学相干层析成像技术,测量通透过程中不同测量深度下组织的散射特征的变化。通过采用系统信号对数的梯度值近似地表征光学散射系数,研究了通透过程中组织的散射特征随渗透时间和测量深度的动态关系。实验证明了组织通透可以有效地增加光子的穿透深度,并改善成像质量。研究发现:不同测量深度处组织的散射系数及其变化幅度、变化过程和变化趋势等均存在一定的差异性,并与组织的微观结构、其通透效果,化学试剂在组织中的渗透行为等有密切关系,有助于组织通透过程的理解,并为组织通透机制提供可能的实验依据。     

Chain motions in lipid-water and protein-lipid-water phases: a spin-label and x-ray diffraction study

An attempt has been made to establish a relation between the rapid reorientational motions of the lipid chains and the structure of the lipid-water and the protein-lipid-water phases. The movements were studied by electron paramagnetic resonance spectra of the fatty acids labelled at different positions along the chain; the structure of the phases, established by X-ray diffraction, differs by the long-range organization (lamellar, hexagonal, etc.) and by the short-range conformation of the chains (liquid-like, α; stiff and hexagonally packed, β or β′). The rapid motions of the hydrocarbon chains are found to be largely independent of the long-range order and highly dependent on the short-range conformation. The mobility of the nitroxide group incorporated within regions in the β (or β′) conformation is low and independent of its position along the chain. On the contrary, the mobility of the nitroxide group incorporated in regions in the α-conformation is high and increases as the position is moved along the chain away from the polar end. Temperature and water content affect the motions of the chains in the α but not in the β-conformation. Moreover, the labels appear to be perfectly soluble in the α regions, whereas the solubility in the βregions varies with the position of the nitroxide group and with the nature of the lipid. As a consequence, among the numerous phase transitions observed in these systems only those which involve a change in the conformation of the chains are accompanied by profound perturbations of the spin-label spectra; when the label is soluble in the β-regions, a discontinuity in chain motions is observed at the α-β transition; when the label is less soluble in the β than in the α-regions, its concentration in the α-regions increases as the α-β transition proceeds and magnetic interactions can be observed. In lipoprotein phases with electrostatic interactions the motions of the chains appear to be unperturbed by the presence of the protein. If the interactions are of the hydrophobic type, the electron paramagnetic resonance spectra indicate that some regions of the chains come in contact with the proteins.     

Feedback suppression of resistive wall modes in a tokamak

The possibility of feedback suppression of the external kink modes in a tokamak with a resistive wall is studied theoretically, assuming that the stabilizing conductors are located at a certain distance from the wall and without making any assumptions regarding the locations of the magnetic sensors that close the feedback circuit and the parameters (i.e., the particular components of the perturbed magnetic field or magnetic fluxes) measured by the sensors. It is shown that the efficiency of the stabilizing system can generally be analyzed within a two-parameter model. The parameters of the problem are the jump in the logarithmic derivative of the radial magnetic field in the region where the stabilizing conductors are positioned and the ratio of the minor radius of the torus on which the conductors are wound to the radius of the wall. However, specific calculations should be carried out with at least a three-parameter model: the final results should depend on the currents in the conductors and the locations of the conductors and magnetic sensors. The relation between the magnetic parameter in the criterion for the suppression of the resistive wall modes and the currents in the stabilizing conductors is clarified, and the current magnitudes required for the suppression are estimated.     

Angioarchitechtonics of the intervertebral disks in human fetuses and newborns]

The ingrowth of the blood vessel branches into the area of the intervertebral disk takes place at the end of the second month of the intrauterine life. The primary vascular elements have a shape of stretched vascular loops, which grow into the fibrous ring of the disk from the front, from behind and from the sides. Within the fibrous tissue the blood vessels are disposed in the slit-shaped spaces between the layers of the fibrous ring. Here the vascular network is formed by anastomosing. These networks have the smaller meshes the closer to the central zones of the intervertebral disk. No blood vessel branches have been found in the jelly-like nucleus. Intraorganic vessels of the intervertebral disk do not penetrate the vertebrum body. The connection between the disk vessels and the vessels of the vertebrum body takes place in the field of the perichondrium.     

Interaction between two major outer membrane proteins of Escherichia coli: the matrix protein and the lipoprotein.

The affinity to the matrix protein, one of the major outer membrane proteins of Escherichia coli, for the peptidoglycan was examined of extracting the cell envelope complex at 55 degrees C and 2% sodium dodecyl sulfate containing different amounts of NaCl. It was found that the matrix protein was extracted from the peptidoglycan of a mutant strain (lpo) that lacks another major membrane protein, the lipoprotein, at a lower NaCl concentration than was the matrix protein of the wild-type cell (lpo+). When the envelope fraction of the wild-type strain was treated with trypsin, which is known to cleave the bound-form lipoprotein from the peptidoglycan, the affinity of the matrix protein for the peptidoglycan decreased to the same level as that of the affinity of the matrix protein for the peptidoglycan of the mutant strain. It was further shown that the free-form lipoprotein was also retained in the matrix protein-peptidoglycan complex, although the extent of retention of the free form of the lipoprotein was less than that of the matrix protein. These results indicate that both the free and the bound forms of the lipoprotein are closely associated with the matrix protein and that the bound form of the lipoprotein plays and important role in the association between the matrix protein and the peptidoglycan.     

Early development of the cerebral vesicles in man.

Two human embryos which were immediately before and soon after the appearance of the cerebral vesicle were cut into complete serial sections in almost the same direction and studied comparatively. The findings on these two sets of serial sections indicate that the rostral continuations of subthalamus and ventral thalamus along the ventral thalamic sulcus continuing from the sulcus limitans of the midbrain are destined to give rise to the formation of the cerebral vesicle. The rostral continuation of the subthalamus becomes the floor of the interventricular foramen, and that of the ventral thalamus the pallium. The rostral end of the continuation of the subthalamic matrix is not only the site of the beginning of evagination of the cerebral vesicle, but also the site of elevation of the ganglionic hill or striatum. As the evagination of the cerebral vesicle proceeds exceedingly dorsocaudolaterally from the rostral end of the continuation of the ventral thalamus, the elevation of the striatum occurs also in the same direction, getting in touch with the folding of the hemispheric stalk of Kuhlenbeck to enclose the interventricular foramen. Tt is noticed that, at the beginning of evagination, the grade of depression of the nasal pit was always parallel with that of evagniation of the cerebral vesicle.     

Effect of adjuvants on the cellular function of the monocytic phagocytosing system]

The authors studied the effect of adjuvants differing by origin and physico-chemical nature (complete Freund's adjuvant, S. typhi endoxin, cadmium sulfate, iron trichloride) on the ingestion and digestion of erythrocytes of the sheep by the cells of monocytic phagocytizing system, on the persistence of the antigen in these cells, its complexation with the RNA-macrophages and the function of their lysosomal apparatus. The adjuvants change the phagocytizing capacity of the macrophages only in their administration in vivo. Administration to the animals of Freund adjuvant and of the S. typhic endotoxin somewhat increased the ingestion of the antigens, whereas the administration of FeCl3 and CdSO4 failed to change it or even somewhat decreased it. The capacity of ingestion of the antigen in vitro in macrophages obtained from the animals treated with the adjuvants was changed in comparison with the normal. All the adjuvants tested produced a marked action on the lysosomal apparatus of the cells of the monocytic phagocytizing system: they changed the activity of catepsin, promoted the accumulation and the retention in the lysosomes of the highly immunogenic fractions of the antigen, and increased the permeability (except the CdSO4 of the lysosomal membranes in the cells of the antigen binding with the RNA of the cells of the peritoneal exudate or the splenic cells.     

The superficial cerebral veins

Estimated were the number, the course, and the width of the superficial cerebral veins. The veins on the superolateral surface of the brain are the prefrontal superficial lateral superior, the precentral superficial lateral superior, the central superficial lateral superior, the parietal superficial lateral superior, and the occipital superficial lateral superior veins which drain to the superior sagittal sinus, to bridging veins, and to the falx cerebri. The veins which drain the lateral surface of the brain downwards are the middle superficial cerebral veins, the temporal inferior, occipital inferior, and anastomotic veins. The diameters of these veins were measured at the perforation of the arachnoid membrane and the diameters of the anastomotic veins on their narrowest area. On the medial side of the hemispheres, we divided in precentral superficial superior medial, central superficial medial, parietal superficial medial, occipital superficial medial dorsal veins of the corpus callosum, and internal occipital veins. On the basal surface of the hemispheres, we studied and described the uncal veins and the inferior hemispheric veins. Studied and discussed are also the bridging veins in the course of the inferior cerebral veins, the paracavernous sinuses, and the last course of the veins and their connections with the dura mater or the course inside the dura. Given are besides the numbers of these veins, the area of perforation of the arachnoid membrane, and their width and medical importance.     

小型猪与梅山猪Prop1基因的比较分析

Prop1是一种新发现的参与早期胚胎垂体发育的特异性转录因子。在人和动物均已发现由于该基因突变而引起的综合性垂体功能障碍,进而影响生长和繁殖。小型猪与梅山猪比较,其繁殖力和生长性能差异显著,为了了解这些差异的遗传基础,本试验对五指山猪、藏猪和版纳猪三种小型猪的Prop1基因进行克隆测序,并与已知梅山猪的序列进行对比,结果为:五指山猪与藏猪外显子1第69位发生G-A碱基替换,编码同义氨基酸;藏猪外显子2第115位发生A-G碱基替换,编码终止密码子;藏猪与版纳猪外显子3第466位和第631位均发生C-T碱基替换,第466位藏猪编码同义氨基酸;第631位版纳猪编码丝氨酸(TCC),梅山猪编码脯氨酸(CCC),即两种猪的Prop1基因产物不同。在Prop1基因终止密码下游250左右有一个腺苷酸丰富区,五指山猪与藏猪有15个腺苷酸串联,版纳猪有12个。上述结果为进一步研究大猪和小型猪之间生产性能差异的遗传基础提供了新线索。     

Distribution of intraventricularly injected horseradish peroxidase in cerebrospinal fluid compartments of the rat spinal cord

Summary The circulation of the cerebrospinal fluid along the central canal and its access to the parenchyma of the spinal cord of the rat have been analyzed by injection of horseradish peroxidase (HRP) into the lateral ventricle. Peroxidase was found throughout the central canal 13 min after injection, suggesting a rapid circulation of cerebrospinal fluid along the central canal of the rat spinal cord. It was cleared from the central canal within 2 h, in contrast with the situation in the brain tissue, where it remained in the periventricular areas for 4 h. In the central canal, HRP bound to Reissner's fiber and the luminal surface of the ependymal cells; it penetrated through the intercellular space of the ependymal lining, reached the subependymal neuropil, the basement membrane of local capillaries, and appeared in the lumen of endothelial pinocytotic vesicles. Furthermore, it accumulated in the labyrinths of the basement membrane contacting the basolateral aspect of the ependymal cells. In ependymocytes, HRP was found in single pinocytotic vesicles. The blood vessels supplying the spinal cord were classified into two types. Type-A vessels penetrated the spinal cord laterally and dorsally and displayed the tracer along their external wall as far as the gray matter. Type-B vessels intruded into the spinal cord from the medial ventral sulcus and occupied the anterior commissure of the gray matter, approaching the central canal. They represented the only vessels marked by HRP along their course through the gray matter. HRP spread from the wall of type-B vessels, labeling the labyrinths, the intercellular space of the ependymal lining, and the lumen of the central canal. This suggests a communication between the central canal and the outer cerebrospinal fluid space, at the level of the medial ventral sulcus, via the intercellular spaces, the perivascular basement membrane and its labyrinthine extensions.     

Scanning motion,ocellar morphology and orientation mechanisms in the phototaxis of the nematode Mermis nigrescens

Summary The putative ocellus of Mermis females consists of a hollow cylinder of dense hemoglobin pigmentation located in the anterior tip. The exact location of the photoreceptive nerve endings, however, is unknown. During phototaxis a continual bending or scanning motion of the head (anterior 2 mm) causes the orientation of the tip to swing about the direction of the source. By turning off (shuttering) the light source whenever the tip orientation was to one side of the source direction, the average orientation of the base of the head, and eventually the body orientation, was caused to be biased about 28° to the opposite side. Because the shuttering was synchronized with the scanning motion, the scanning motion must be involved in the maintenance of orientation to light. The direction of the bias rules out a two-signal comparison mechanism of orientation and demonstrates that a deviation of the tip from the source direction must decrease, rather than increase, the illumination of the photoreceptors. These findings, and the ocellar morphology, require that the photoreceptors be located inside the hollow tube of pigmentation where they can be shadowed by the pigment during deviations of the tip. Focusing by the curved anterior end should cause a similar modulation of the illumination at this location. The occasional episodes of transverse phototaxis can be explained by the leakiness of the pigment walls to transverse illumination. Analysis of the motion of the anterior in the presence and absence of shuttering indicates that the orientation of the base of the head, due to the motion of the neck, is controlled by the signals generated during one or more cycles of the scanning motion of the head. The orientation may be regulated by the phase relationship between the photoreceptor signal and putative proprioceptive signals that indicate the bending in the head.     

瓦氏马尾藻规模化繁育技术研究

研究了瓦氏马尾藻(Sargassum vachellianum)规模化育苗及海区养殖技术。采集海区成熟藻体, 室内催熟放散受精卵, 收集并喷洒于水泥板、棕绳、木板3种附着基, 进行受精卵附着、萌发及苗体生长等实验, 发现棕绳育苗效果最佳。受精卵喷洒10d后, 3种附着基的出苗率分别为 85.5%、80.2%和91.3%, 平均株高约1.3 mm。前20天木板幼苗密度最高, 达8.2株/cm2, 但幼苗均生长缓慢。第30天, 幼苗出现明显分枝, 生长率增大到前20天的1.6倍, 其中棕绳幼苗株高最大, 幼苗存活率分别为83.6%、79.7%和75.6%。第60天棕绳幼苗密度及平均株高均最大。将附有幼苗的水泥板(藻礁)、棕绳放入海区进行养殖, 发现幼苗在浪大流急海区生长较快, 4周后平均株高分别达98.7和103.1 mm, 是对照组的1.5倍, 但棕绳脱苗严重。藻礁较适合海区规模化投放养殖, 是藻场修复和重建的理想材料。