低粘低切流场中渗透压对红细胞取向与变形的影响

本文研究了低粘低切流场中渗透压对红细胞取向与变形的影响，发现随着渗透压的变化，ＤＩ、ＤＩｏｒ有相同的变化形式，而ＤＩｄ基本保持不变。说明低粘低切流场中，ＤＩｄ可能只与红细胞膜的力学性质有关。而ＤＩｏｒ可能反映红细胞膜及其整体的弯曲弹性膜量。     

Orientation of the peptidoglycan chains in the sacculus of Escherichia coli

The organization of chains of oligopeptidoglycan in the saccular wall is of critical importance in the study of the mechanism and physiology of prokaryotic wall growth. The electron microphotographs of De Pedro et al, present new findings and can be used to negate or at least raise questions about the previously accepted conclusion that the glycan chains are oriented transversely to the axis of rod-shaped Escherichia coli. This suggests caution in assuming that the glycan chains in the murein structure are parallel to each other and are perpendicular to the axis of the cell.These results should reopen the question of not only the orientation of the peptidoglycan chains, but the possibility of variability in orientation. Three classes of hypotheses about wall growth are reconsidered and problems with them are presented. The new results from De Pedro's laboratory and the experimental glycan chain length distribution argue against proposed systematic models. These include models that postulate belts or hoops stretched around the circumference of the cell and mechanisms that insert new chains of the length of presumptive “docking” strands in the stress-bearing wall. They are consistent, however, with the surface stress theory that proposes that random enzyme action together with physical forces are involved in the elongation of the rod-shaped Gram-negative wall.     

住院病人中有自杀倾向者的原因及对策

目的 探讨住院病人中有自杀倾向者的原因与对策.方法 收集采取干预措施前后5个年度的住院病人为研究对象.并对其中有自杀倾向者患者的资料进行统计学处理.结果 采取干预措施前后有自杀倾向者的病人比率并未减少,但自杀死亡率明显降低,P＜0.05.结论 引发病人自杀死亡的原因中,以各类早期癌症、恶劣心境为高危人群,采取适合于病人的个性化防范措施能有效地干预病人的自杀行为.     

Functional associations between collagen fibre orientation and locomotor strain direction in cortical bone of the equine radius

A novel technique for determining the collagen fibre orientation pattern of cross-sections of cortical bone was used to study mid-diaphyseal sections from the equine radius. Several in vivo strain gauge studies have demonstrated that this bone is loaded in bending during locomotion in such a way that the cranial cortex is consistently subjected to longitudinal tensile strains and the caudal cortex to longitudinal compressive strains. Twenty-three radii from 17 horses were studied. All the bones obtained from adult horses exhibited a consistent pattern of collagen fibre orientation across the cortex. The cranial cortex, subjected to intermittent tension, and the lateral and medial cortices, through which the neutral axis passes, contained predominantly longitudinally oriented collagen fibres. The caudal cortex, subjected to longitudinal compression during life, contained predominantly oblique/transverse collagen. This pattern was less evident in bones from foals. Microscopic analysis of the bones studied showed that primary lamellar bone was composed of predominantly longitudinal collagen fibres, irrespective of cortex. However, there was a strong relationship between cortical location and fibre orientation within remodelled bone. Secondary osteons which formed in the caudal (compressive) cortex contained predominantly oblique/transverse collagen, while those which formed elsewhere contained longitudinal collagen. This observation explained the developmental appearance of the characteristic macroscopic pattern of collagen fibre orientation across the whole cortex in the adult. These findings provide evidence for the existence of a relationship between the mechanical function of a bone with its architecture, and now demonstrate that it extends to the molecular level.     

SELECTIVE HABITUATION OF GALVANIC SKIN RESPONSE COMPONENT OF THE ORIENTATION REACTION TO AN AUDITORY STIMULUS

The prediction from Sokolov's (1960) theory that, following OR habituation, size of OR return is proportional to the amount of difference between the new stimulus and the habituating stimulus was tested using an auditory stimulus varying in frequency and intensity. Five Ss were allocated to each of 16 conditions, three conditions involving changes in frequency, three involving changes in intensity, nine involving changes in both frequency and intensity, with one control condition involving a repetition of the habituating stimulus. Following habituation of the GSR component of the OR to a criterion of response failure for three successive trials, magnitude of GSR under the 16 conditions was measured. Contrary to Sokolov's theory, only increase in intensity had a significantly different effect on OR return. More importantly, it was found that Ss habituating rapidly to the initial stimulus were less likely to show OR return to stimulus change. It was concluded that individual differences in habituation rate may be more important than stimulus difference effects in selective habituation.     

Restriction of visual experience to a single orientation affects the organization of orientation columns in cat visual cortex

Summary and Conclusions In six dark reared, 4-weak-old kittens visual experience was restricted to contours of a single orientation, horizontal or vertical, using cylindrical lenses. Subsequently, the deoxyglucose method was used to determine whether these artificial raising conditions had affected the development of orientation columns in the visual cortex. After application of the deoxyglucose pulse one hemifield was stimulated with vertical, the other with horizontal contours. Thus, from interhemispheric comparison, changes in columnar systems corresponding to experienced and inexperienced orientations could be determined. The following results were obtained: (1) Irrespective of the restrictions in visual experience, orientation columns develop in areas 17, 18, 19 and in the visual areas of the posterior suprasylvian sulcus. (2) Within area 17, spacing between columns encoding the same orientations is remarkably regular (1 mm), is not influenced by selective experience and shows only slight interindividual variation. (3) In non-striate areas the spacing of columns is less regular and the spatial frequency of the periodicity is lower. (4) The modifiability of this columnar pattern by selective experience is small within the granular layer of striate cortex but substantial in non-granular layers: Within layer IV columns whose preference corresponds to the experienced orientation are wider and more active than those encoding the orthogonal orientation but the columnar grid remains basically unaltered. Outside layer IV the columnar system is maintained only for columns encoding the experienced orientations. The deprived columns by contrast frequently fail to extend into non-granular layers and remain confined to the vicinity of layer IV. (5) These modifications in the columnar arrangement are more pronounced in striate cortex than in non-striate visual areas and, within the former, more conspicuous in the central than in the peripheral representation of the visual field. It is concluded that within layer IV the blue print for the system of orientation columns is determined by genetic instructions: first order cells in layer IV develop orientation selectivity irrespective of experience whereby the preference for a particular orientation is predetermined by the position in the columnar grid. Dependent on experience is, however, the expansion of the columnar system from layer IV into non-granular layers. It is argued that all distortions following selective rearing can be accounted for by competitive interactions between intracortical pathways, the mechanisms being identical to those established for competitive processes in the domain of ocular dominance columns. It is proposed that such experience dependent modifiability of connections between first and second order cells is a necessary prerequisite for the development of orientation selectivity in cells with large and complex receptive fields.This work has partially been supported by a grant from the Deutsche Forschungsgemeinschaft, SFB 50, A14Dedicated to Prof. D. Ploog on the occasion of his 60th anniversaryResearch Fellow of the Alexander-von Humboldt-Stiftung     

医护人员工作倦怠的调查

目的：了解医护人员的工作倦怠现状。方法：采用MBI—HSS对218名医护人员进行了调查。结果：42．1％的被试有一定程度的情绪衰竭现象；有22．7％的被试有一定程度的情感疏远现象；48．6％的被试没有个人成就感；女性医护人员在情绪衰竭方面要显著高于男性医护人员；高中学历被试的情绪衰竭要显著高于大专、本科和本科以上学历的被试；高中学历被试的个人成就感要低于大专和本科以上学历的被试。结论：部分医护人员有一定程度的工作倦怠，在预防和矫治工作倦怠时。应重点关注女性和低学历人员。     

The role of anterior ectosylvian cortex in cross-modality orientation and approach behavior

Physiological and behavioral studies in cat have shown that corticotectal influences play important roles in the information-processing capabilities of superior colliculus (SC) neurons. While corticotectal inputs from the anterior ectosylvian sulcus (AES) play a comparatively small role in the unimodal responses of SC neurons, they are particularly important in rendering these neurons capable of integrating information from different sensory modalities (e.g., visual and auditory). The present experiments examined the behavioral consequences of depriving SC neurons of AES inputs, and thereby compromising their ability to integrate visual and auditory information. Selective deactivation of a variety of other cortical areas (posterolateral lateral suprasylvian cortex, PLLS; primary auditory cortex, AI; or primary visual cortex, 17/18) served as controls. Cats were trained in a perimetry device to ignore a brief, low-intensity auditory stimulus but to orient toward and approach a nearthreshold visual stimulus (a light-emitting diode, LED) to obtain food. The LED was presented at different eccentricities either alone (unimodal) or combined with the auditory stimulus (multisensory). Subsequent deactivation of the AES, with focal injections of a local anesthetic, had no effect on responses to unimodal cues regardless of their location. However, it profoundly, though reversibly, altered orientation and approach to multisensory stimuli in contralateral space. The characteristic enhancement of these responses observed when an auditory cue was presented in spatial correspondence with the visual stimulus was significantly degraded. Similarly, the inhibitory effect of a spatially disparate auditory cue was significantly ameliorated. The observed effects were specific to AES deactivation, as similar effects were not obtained with deactivation of PLLS, AI or 17/18, or saline injections into the AES. These observations are consistent with postulates that specific cortical-midbrain interactions are essential for the synthesis of multisensory information in the SC, and for the orientation and localization behaviors that depend on this synthesis.     

Inactivation of the infragranular striate cortex broadens orientation tuning of supragranular visual neurons in the cat

Intracortical inhibition is believed to enhance the orientation tuning of striate cortical neurons, but the origin of this inhibition is unclear. To examine the possible influence of ascending inhibitory projections from the infragranular layers of striate cortex on the orientation selectivity of neurons in the supragranular layers, we measured the spatiotemporal response properties of 32 supragranular neurons in the cat before, during, and after neural activity in the infragranular layers beneath the recorded cells was inactivated by iontophoretic administration of GABA. During GABA iontophoresis, the orientation tuning bandwidth of 15 (46.9%) supragranular neurons broadened as a result of increases in response amplitude to stimuli oriented about ±20° away from the preferred stimulus angle. The mean (±SD) baseline orientation tuning bandwidth (half width at half height) of these neurons was 13.08±2.3°. Their mean tuning bandwidth during inactivation of the infragranular layers increased to 19.59±2.54°, an increase of 49.7%. The mean percentage increase in orientation tuning bandwidth of the individual neurons was 47.4%. Four neurons exhibited symmetrical changes in their orientation tuning functions, while 11 neurons displayed asymmetrical changes. The change in form of the orientation tuning functions appeared to depend on the relative vertical alignment of the recorded neuron and the infragranular region of inactivation. Neurons located in close vertical register with the inactivated infragranular tissue exhibited symmetric changes in their orientation tuning functions. The neurons exhibiting asymmetric changes in their orientation tuning functions were located just outside the vertical register. Eight of these 11 neurons also demonstrated a mean shift of 6.67±5.77° in their preferred stimulus orientation. The magnitude of change in the orientation tuning functions increased as the delivery of GABA was prolonged. Responses returned to normal approximately 30 min after the delivery of GABA was discontinued. We conclude that inhibitory projections from neurons within the infragranular layers of striate cortex in cats can enhance the orientation selectivity of supragranular striate cortical neurons.     

护士主导的高血压管理范围综述

目的对国内外护士主导的高血压管理相关研究进行范围审查,为完善护士主导的高血压防治措施提供循证建议。方法系统检索中国生物医学文献数据库、中国知网、万方、维普、Web of Science、PubMed、CINAHL、Cochrane和Embase等数据库2010年1月1日至2020年9月20日相关研究,提取相关信息。结果共纳入22篇文献。主导护士类别包括社区护士、医院护士、专科护士,管理团队以护士主导的多学科团队为主,管理形式以面对面会议、电话随访、电子邮件等形式为主,管理内容涉及评估、设定健康目标、个性化指导、与多学科团队沟通、转介、评价与反馈等,评价指标以患者血压变化/血压控制达标率、治疗/服药依从性为主,仅1项以社区护士为主导的研究显示与常规护理相比血压未明显下降。结论护士主导的高血压管理措施对单纯性原发性高血压具有较好效果。建议基于区域医联体,建立医院—社区—家庭高血压管理模式;完善我国社区护士认证与培养体系;借鉴其他发展中国家护士处方权经验,结合我国国情,制定相关法律法规,适当给予护士一定范围内处方权;发展“互联网+”慢病管理模式。