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1.
Vasomotor responses from the nasal mucosa and tongue, and contractions of the nictitating membrane, were recorded on stimulation of the cervical sympathetic or internal carotid nerves. Preganglionic sympathetic nerve fibres which elicited a membrane response possessed a lower threshold than those which evoked nasal vasoconstriction, while the latter displayed a lower threshold than fibres which evoked tongue vasoconstriction. The sympathetic vasodilator fibres to the tongue whose activity was revealed after alpha-receptor blockade, had a similar threshold to the vasoconstrictor fibres. Membrane contraction, nasal vasoconstriction and occasionally tongue vasoconstriction could be evoked by stimulating the internal carotid nerve. The postganglionic fibres innervating the nasal mucosa had a similar threshold to those of the nictitating membrane, which may indicate that there are small myelinated fibres innervating the mucosa. The preganglionic compound nerve action potential had four major components, S1-S4. S1, S2 and usually S3 fibres were associated with membrane contraction; S2, S3 and sometimes S1 fibres were associated with nasal vasoconstriction; and S3, usually S2 and occasionally S1 fibres were associated with vasoconstriction in the tongue. It is concluded that each of these three groups of nerve fibres, but not S4 fibres, may include fibres associated functionally with the three effectors. There was a considerable difference between the relative amplitude of the responses of the three effectors elicited by stimulation of the cervical sympathetic nerve at frequencies between 0.2 and 2 Hz. Vasoconstrictor responses were relatively larger than membrane contractions suggesting differences in the mechanisms of neurotransmission at the neuroeffector junctions.  相似文献   

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3.
We present an overview of the results obtained in a cross-transplantation system using respectively controls, jimpy (jp), and shiverer mutant mice as donors and recipients. Homochronic transplantations (O days into O days) demonstrated that jp environment is non-toxic for non-jp cells and that, contrary to in vitro, jp oligodendrocytes phenotype cannot be modified by environmental factors at this age. Transplantations of embryonic fragments into the newborn brain demonstrated that in contrast to oligodendrocyte precursors contained in fragments of newborn tissue, jimpy embryonic stem cells are sensitive to environmental factors able to modulate the proportion of surviving oligodendrocytes. In addition, these series evidenced a disjunction between the surviving and the myelinating capacity of jp cells demonstrating a pleiotropic effect of the jp mutation on oligodendrocyte biology. Results are discussed with regards to the recent molecular biological finding on the role of the DM20/PLP gene.  相似文献   

4.
The dorsal approach to the metacarpal bones is through the peritendinous connective tissue of the extensor tendons. Knowledge of the vascular supply of the distal parts of these tendons, between the distal end of the tendon sheath and the tendon's osseous insertion is important, especially with respect to atraumatic technique. The course and distribution of the vessels to the extensor tendons II-V were investigated. Superficial and deep layers of connective tissue were found to contain blood vessels. The superficial vessels reach the dorsal aspect of the extensor tendon, originating from subcutaneous arteries and the large arteries of the hand. The deep vessels reach the lateropalmar aspect of the tendons and originate from the peritendinous muscular arteries. Vessel distribution suggests a direct relationship between the number of nourishing arteries and the tendon surface area. The vascular supply to the unsheathed parts of the extensor tendons shows morphological adaptations to differential mechanical stress during tendon excursion.  相似文献   

5.
The object of studies was an alumina plant operating according to the Bayer process; the basic tool of these studies was a computer model of alumina production which allows optimization. Methods have been developed, which make it possible to reveal the degree of the influence of the properties of raw materials and technological characteristics of production on the economic efficiency of the production. The greatest attention was given to the technological processes which form the Bayer cycle, i.e., to leaching, decomposition, thinning, and evaporation. The process of the passage of material flows through the entire Bayer cycle and the obtaining of qualitative and quantitative characteristics of these flows has been simulated. A model of phase diagrams which makes it possible to approximately determine the shape and position of the solubility isotherms of gibbsite depending on temperature has been constructed. The main result of this work is the development of an efficient tool which ensures conducting the optimization of the most important technological characteristics of alumina production on the basis of its complex technical and economic estimation.  相似文献   

6.
The data are presented on changes in the rat arcuate nuclear neuron ultrastructure after using cyproheptadine (peritol, Egyt Pharmaceutical Works, Hungary) in a water suspension at a dose of 20 mg/kg once daily during 7 successive days and twice a day within 10 days. It was shown that cyproheptadine decreases the functional activity of the arcuate nuclear neurons, depending on the total amount of the drug used. Cyproheptadine-induced inhibition of the forming neurohormone release from neurons is likely to be one of the mechanisms of its therapeutic effect in Itsenko-Cushing's disease.  相似文献   

7.
CONTEXT: Disputes associated with achieving recognition for work done may affect both morale and subsequent resource allocation to medical researchers. OBJECTIVE: To assess authorship disputes brought to the Ombuds Office. SETTING: The Ombuds Office, Harvard Medical School, Dental School, School of Public Health, and affiliated hospitals. MAIN OUTCOME MEASURE: Change in number of queries related to authorship between 1991 to 1992 and 1996 to 1997. RESULTS: Disputes increased from 8 (2.3%) of 355 issues brought to the office in 1991 to 1992 to 59 (10.7%) of 551 issues in 1996 to 1997. They also increased from involving 0.06% of the total population of faculty, staff, and students affiliated with the schools in 1991 to 1992 to 0.33% of the total population in 1996 to 1997. Such problems appear to occur more often for women (53% of complaints in 1994-1995 through 1996-1997) and for non-US citizens (21 % of complaints in 1991-1992 through 1996-1997). CONCLUSIONS: Authorship disputes are increasingly frequent. Institutions should increase enforcement of published authorship standards and place more emphasis on managerial skills for laboratory and research department heads.  相似文献   

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9.
Clinicohematological investigations and cytogenetic analysis of blood lymphocytes were made 5-7 years after the Chernobyl accident in 201 liquidators who had worked in the radionuclide-contaminated zone. Among the somatic diseases found in the examinees statistically more prevalent were cardiovascular and gastrointestinal affections, asthenic syndrome, thyroid disorders. Hemograms presented a rise in hemoglobin, red cell and eosinophil content, a drop in the number of neutrophils. A tendency to erythrocytosis was observed in 20.3% of the wreckers. Dicenters and rings were abundant in the lymphocytes of 69% of the cytogenetically examined examinees 5-7 years after the exposure to radiation.  相似文献   

10.
A 14-year-old girl developed a firm mass at the base of the tongue. Computed tomography indicated marked density suggesting either a foreign body or bony tissue. A thyroid scan confirmed the presence of a normally sized and positioned gland. The mass was removed in toto and found to be an osteoma. This is the first report of a case in which the diagnosis of this rare developmental lesion of the tongue was achieved preoperatively based on clinical and radiologic information. This experience should lead to greater awareness of this entity in the future. Recognition of this entity in the pediatric age group is especially useful in avoiding misdiagnosis of other, potentially more aggressive types of tongue mass lesions. Our case demonstrates that it is possible to detect this entity using computed tomography. The dense calcification is truly characteristic of the tumor and may be relied upon to exclude alternative soft tissue mass lesions. While other forms of osseous and cartilagenous neoplasms, such as extraskeletal osteosarcoma and chondrosarcoma, have been reported arising in the tongue, their malignant nature should otherwise be readily apparent. Osteoma of the tongue is the favored diagnosis when mature bone tissue is imaged at the base of the tongue.  相似文献   

11.
The ventral attachement of the ligamentum vocale of eleven larynges (new-born and adults has been studied in sagittal, frontal and horizontal sections. 1. Supplementary to the known structure of the ventral attachement of the ligamentum vocale we have noticed collagen fibers which ascend in the inner angle of the thyroid cartilage and which partly cross to the other side. Sometimes a few fibers which are running downward have been observed. This structure of the attachement must be more firm than the known structure. 2. Moreover it has been observed that a lot of the angles of the crossing collagen fibers in the cartilage of the lamina mediana (near the attachement of the ligamentum vocale) are right-angled, whereas the angles of the fibers which lie in the laminae laterales in their majority are acute-angled. This phenomenon also is interpreted as a structure which makes the lamina mediana firmer. The fact, that this structure is not so evident in the specimens of the new-born as in those of the adults indicates that there are postnatal changes in the structure of the lamina mediana.  相似文献   

12.
加强烧结过程控制与稳定烧结矿质量   总被引:1,自引:0,他引:1  
张德金 《中国锰业》2009,27(1):55-58
烧结矿的金属性能包括机械强度、氧化还原性和强度稳定性项指标,而影响这些因素种类繁多、错中复杂。介绍了烧结厂通过加强对烧结全过程的控制,稳定烧结矿金属质量的方法和效果。  相似文献   

13.
Examining 230 edentulous patients, a significant degree of atrophy in the maxilla and mandible relatively often has been found. Atrophy could be detected more often in the mandible of female patients. For these forms of manifestation, among others, systemic causes: osteoporosis, diabetes and periodontal disease could be found. The results and their classification may help to draw the attention in the course of treatment to strong dissimilarities or similarities of the edentulous mouth. The degree of atrophy observed on both jaw-bones--among other factors--is significant for the planning and prognosis when indicating total prosthetic treatment.  相似文献   

14.
The L-DOPA and sulpiridinum effects on the enzymatic transporting function of the enterocytes' membrane, were studied in rats under stress. The L-DOPA was shown to hinder the absorption rate of glucose, whereas sulpiridinum was shown to suppress the main enzymes excepting snerase and alkaline phosphatase, to increase the monomeric and hydrolysate glucose transport. The L-DOPA seems to play a modifying role in the regulation and integration of the digestive-transporting function of the enterocytes' membrane in rats under stress.  相似文献   

15.
为了保障矿山企业的发展与矿山地质自然环境形成协调的发展模式,应对矿山深层水位的沉降进行检测,水工环地质调查是确定矿山地下水位深度的有效手段之一。基于此,开展对矿山地质构造沉降监测中水工环地质调查的作用分析研究,通过研究得出,水工环地质调查可以提高矿山地质构造沉降监测结果精准度、为矿山地质构造沉降提供应急方案、保障矿山地质构造沉降监测工作效率等作用,对实现矿山企业的精细化施工提供有利条件。  相似文献   

16.
To treat pathological processes, primarily tumors, in the base of the skull is one of the most intricate neurosurgical problems. In the past decade, interest in this problem has greatly increased due to the advent of new methods of diagnosis, up-to-date neurosurgical equipment and to a greater cooperation of physicians of related disciplines: ophthalmologists, otosurgeons, plastic surgeons. The authors present and summarize the experience accumulated by the researchers of the N. N. Burdenko Institute of Neurosurgery in the past 10 years in treating basal tumors. Based on a great deal of clinical findings, approaches are proposed in treating some groups of basal tumors, such and pituitary adenomas, craniopharyngiomas, meningiomas at various sites, trigeminal and acoustic neurinomas, and malignant neoplasms of the base of the skull. The conditions required for successful surgical treatment of the processes in the base of the skull are described in detail. One of them is a correct determination of a surgical approach.  相似文献   

17.
The brain (supraoesophageal ganglion) is the most complex of the segmental ganglia composing the nerve cord of the locusts Schistocerca gregaria and Locusta migratoria. In this paper, we describe the ground plan of the commissures crossing the midline of the brain and propose a nomenclature with the aim of making a complex neuropil more understandable at the level of individual neurons. For developmental and comparative reasons the neuroarchitecture of the brain is related to the neural axis, not to the body axis. We have identified 73 commissural fiber bundles belonging to the adult brain, and these are named according to their location (ventral, dorsal, anterior, posterior, medial) with respect to the central complex as reference point. Reconstructions of identified neurons from intracellular stainings, cobalt backfills, or immunohistochemical studies demonstrate the various configurations in which fibers cross the brain.  相似文献   

18.
Reducing the period of Milk rearing of calves from 90 days (time of weaning) as practised today to 50 days or 70 days (and thus reducing the amount of regenerated milk which is needed to rear the calf from 400 litres to 200 litres or 300 litres) would limit the rate of weight gains of the calves in the first 3 months of age. This delay is, within certain limits, compensated for by the calf in the growth period up to 6 months of age. Therefore, the authors believe that with cattle of the Hungarian breed "Ungarische Fleckviehrasse" weaning after 50 days and rearing the calves with 200 litres of milk seems to be possible. The method of early weaning and then feeding stock mixtures of concentrates seems to be also applicable provided that the conditions of veterinary hygiene would allow this. This, in turn, would require supplementation of the food with minerals and vitamins. Due to the results obtained supplementation of concentrate mixtures with urea for calf rearing is also possible, even under practical conditions. Aromatization of the concentrate mixtures, as practised in the present series of trials, did not substantiate the favourable results obtained by the authors in previous trials with respect to the effect of aromatics on food consumption and the development of weight gains.  相似文献   

19.
These minutes are the official record of the actions of the American Psychological Association taken during the year by both the Board of Directors (the Board) and the Council of Representatives (Council). The roll of representatives was called at each Council meeting, and more than a quorum answered to their names. Reference is made in these minutes to various reports, some of which will be published elsewhere. Copies of these reports were distributed to Council and are on file in the Central Office. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
P2ERW管代替无缝管,用于石油开采所用油管和套管的关键,是确保焊缝的高质量。它不仅需要具备先进的技术装备和完善的检测手段,更需要发挥金相检验对优化各项工艺参数的指导作用,才能从根本上掌握生产优质ERW石油用管的规律。  相似文献   

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