Bifurcation properties of the two process model

Abstract Daan's two process model is known to be one of the most powerful models, covering various situations from free-running to sleep deprivation. In this study, bifurcation properties of the model dynamics as function of a gap, D , between the threshold processes are clarified using a circle map. As a function of D , we will show that the model has the different types of the mutual entrainment regions that are intervened by the tangent bifurcation. The variable behavior of human circadian rhythm is suggested to be systematically understood based on the bifurcation properties of the two process model.     

Advancing Nursing Practice with a Unit-based Clinical Expert

Objective: To explore patterns in the practice of nursing and patient outcomes.
Design: Qualitative field research.
Population, Sample, Setting: Populations were critical care nurses and critically ill adult patients in the 10-bed medical critical care unit of a 900-bed teaching hospital. A convenience-purposive sample of 27 nurses and 31 patients was studied in 1985.
Methods: Six months of participant observation, unstructured interviews, and the constant comparison method of grounded theory.
Findings: Markedly different patterns were found in expert and nonexpert practice. The substantive theory of conversion helped explain how the majority of nonexpert nurses advanced their practice. The metaphor of catalyzed conversion captures how a unit-based expert nurse serves as a catalyst to advance the practice of nonexperts. Presence, defined as the way of being within a given clinical context, differentiated nurses.
Conclusions: (a) Expert and nonexpert practices are substantively different, (b) Expert and nonexpert practice results in different patient outcomes, (c) Conversion helps explain changes in nonexpert practice.
Clinical Implications: A unit-based expert nurse can increase patient-focused care.     

New view of the organization of the pulvinar nucleus in Tupaia as revealed by tectopulvinar and pulvinar-cortical projections

The projections of the superficial layers of the superior colliculus to the pulvinar nucleus in Tupaia were reexamined by injecting WGA-HRP into the tectum. The main result was finding two different patterns of terminations in the pulvinar nucleus: a zone remote from the lateral geniculate nucleus, which occupies the dorsomedial and caudal poles of the pulvinar nucleus, was almost entirely filled with terminals in every case irrespective of the location of the injection site; and a second division of the pulvinar nucleus, adjacent to the lateral geniculate nucleus, contained irregular patches--much more densely populated--and the distribution of patches varied from case to case. We call the first projection "diffuse" and the patchy projection "specific." Next we injected several divisions of the extrastriate visual cortex to find the cortical target of each pathway. The diffuse path terminates in the ventral temporal area (Tv). The specific path terminates in the dorsal temporal area (Td) and area 18. We speculated about the significance of the two pathways: the specific path may be responsible for the preservation of vision after removal of the striate cortex; the diffuse path may have an important place in the evolution of the visual areas of the temporal and occipital lobe. We argued that the target of the diffuse path is in a position to relate limbic and visual impulses and relay the product of such integration to the other visual areas, striate as well as extrastriate cortex.     

11项心功能指标的计算方法及微机处理

本文用OMEGA 500型Υ相机和MCS 560计算系统,即SPECT,R波门控采集心血池图象,在此基础上进行曲线分析,编制BASIC程序计算11项心功能指标。临床应用结果表明:PFR、LVFF、FFR是舒张期功能的优选指标,其它指标对心功能评价也都有显著意义。     

Sleep in seasonal affective disorder patients in forced desynchrony: an explorative study

The majority of winter-type seasonal affective disorder (SAD) patients complain of hypersomnia and daytime drowsiness. As human sleep is regulated by the interaction of circadian, ultradian and homeostatic processes, sleep disturbances may be caused by either one of these factors. The present study focuses on homeostatic and ultradian aspects of sleep regulation in SAD. Sleep was recorded polysomnographically in seven SAD patients and matched controls subjected to a 120-h forced desynchrony protocol. In time isolation, subjects were exposed to six 20-h days, each comprising a 6.5-h period for sleep. Patients participated while being depressed, while remitted after light therapy and in summer. Controls were studied in winter and in summer. In each condition, the data of each subject were averaged across all recordings. Thus, the influence of the effects of the circadian pacemaker on sleep was excluded mathematically. The comparison of patients with controls and with themselves in the various conditions revealed no abnormalities in homeostatic parameters: sleep stage variables, relative power spectra and time courses of power in various frequency bands across the first three non-rapid eye movement-rapid eye movement (NREM-REM) cycles showed no differences. The data suggest that homeostatic processes are not involved in the disturbance of sleep in SAD.     

人和大鼠腰椎关节突关节的SP能神经纤维的分布

目的：证实支配腰椎关节突关节的神经支配和化学性质，方法：用逆行荧光素标记结合免疫组化法，研究７只大鼠腰部脊神经节细胞的周围突分支投射到腰椎关节突关节及其递质性质以及３例人腰椎关节突关节囊上神经末梢的化学性质，结果：发现大鼠一侧Ｌ５和Ｌ６之间的关节突关节受同侧Ｌ２－５节段的脊神经节的部分细胞周围突分支支配，其中有３３．３９９％的中型和小型细胞为中ＳＰ能免疫反应阳性，人的关节突关节囊含有ＳＰ阳性的神经     

胫骨外侧髁骨折塌陷对关节轴线及接触压力的影响

目的:研究在胫骨外侧髁骨折中关节面塌陷和外侧半月板切除对膝关节轴线、接触面积及压力的影响。方法:6个新鲜尸体膝关节标本制成胫骨外侧髁劈裂骨折模型,通过使用支撑垫片制成关节面塌陷0、1、2、4和6mm。膝关节在屈膝0°,负荷500N和屈膝30°,负荷350N。通过数码相机记录关节轴线的变化;而关节内外间隙的压力和压力扩散则由F-Scan感应器记录。每个标本在保留和切除外侧半月板下进行测试。结果:随着关节面塌陷高度的增加,膝关节外翻角度、外侧间隙的平均和最大的接触压力逐渐增加,而接触面积则逐渐减少。在屈膝0°,关节面塌陷6mm时,外翻角度平均增加7.6°,平均接触压力和最大接触压力分别增加208%和97%;而接触面积则减少33%。在同一关节面塌陷高度,切除半月板平均增加38%的外翻角度和外侧间隙45%的接触压力;而接触面积则减少26%。结论:研究结果表明在治疗胫骨外髁劈裂骨折中,减少关节面的塌陷十分重要,特别是在需切除半月板的时候。     

Biochemical and morphological characterization of sympathetic neurons grown in a chemically-defined medium

Previous studies have demonstrated that individual neurons from neonatal rat superior cervical ganglion express a mixed adrenergic-cholinergic phenotype when grown under certain tissue culture conditions.^{9,14,15,29,30} The expression of this phenotype is critically influenced by a number of undefined components present in the culture medium.^18,23,33 In the present study, we have examined whether superior cervical ganglion neurons grown on a chemically defined serum-free medium similarly develop dual transmitter expression, or if under these conditions, neurons express only those properties characteristic of their adrenergic heritage. To address this issue, we established that superior cervical ganglion neurons could be maintained in culture for extended periods on the defined medium described by Bottenstein & Sato⁴ in the absence of supporting cells. We then studied the biochemical, immunocytochemical and ultrastructural characteristics of these neurons. We found that in defined medium, superior cervical ganglion neurons continued to express, in a modified form, certain of their expected adrenergic properties, including the development of tyrosine hydroxylase and dopamine-β-hydroxylase activities, stores of endogenous norepinephrine, synaptic vesicles with dense cores and tyrosine hydroxy lase-immunoreactive staining properties. Superior cervical ganglion neurons grown on a defined medium did not, however, acquire cholinergic traits in culture. In this paper we show that choline acetyltransferase activity did not reach detectable levels; the companion paper¹³ documents that cholinergic synapses were not formed.We conclude that superior cervical ganglion neurons, grown under serum-free culture conditions, develop certain properties characteristic of adrenergic neurons and do not express a mixed adrenergic cholinergic phenotype. A companion paper¹³ describes the electrophysiological properties of these neurons and demonstrates the frequent occurrence of electrotonic synapses in these cultures.     

带臂外侧上皮神经及其营养血管筋膜皮瓣的应用解剖

目的:为带臂外侧上皮神经及其营养血管筋膜皮瓣提供解剖学基础.方法:32例经灌注红色乳胶的成人上肢标本,对臂外侧上皮神经及其营养血管等进行了较详细的应用解剖学研究.结果:臂外侧上皮神经在均由腑神经发出,起点横径为1.5±0.4mm,在三角肌深方斜向外下3.6±1.1cm从该肌后缘中1/3浅出肌间隔,分为上支和下支,分布于三角肌后部、外侧部和臂外侧上部.该神经的营养血管起源于旋肱后动脉,起点外径为0.9±0.4mm;其行程、分支和分布均同在神经,供血范因为14.8×9.8cm~2,并与周围的皮动脉存在丰富吻合.结论:带臂外侧上皮神经及其营养血管筋膜皮 瓣可视受区需要设计成游离瓣或旋转瓣,用于修复邻近部位、手或颌面部缺损.