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Influences of traditional Chinese medicine intervention on the bone growth and metabolism of rats with simulated weightlessness 被引量:4
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作者 Jun Zhu 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2013年第3期224-227,共4页
Objective:To prohe into the influences of Chinese herbal compound on the growth and metabolism of weight-bearing bones of tail-suspended rats.Methods:Twenty-four male St) rats were randomly divided into blank conlrol ... Objective:To prohe into the influences of Chinese herbal compound on the growth and metabolism of weight-bearing bones of tail-suspended rats.Methods:Twenty-four male St) rats were randomly divided into blank conlrol group leighti.tail-suspended conlrol group(eight) and Chinese medicine treatment group leighti according to their weights.No treatment was done for the blank conlrol group.Double distilled water lavage was performed daily for the tail-suspended control group.On the basis of the tail-suspended rat model,the rats were given Chinese herbal compound lavage every day in Chinese medicine treatment group.This compound includes mulberry,Poria cocas and barbary wolfberry.etc.The lest cycle was four weeks.The rats were killed after the experiment.The right femoral bone was taken out for the physical measurements, and the left femoral bone was for the three-point beading test.The influences of Chinese herbal compound on femoral hone growth and biomechanicsl properties of simulated weightlessness rats were observed.Results:(1) After simulated weightlessness(tail-suspension),compared with the blank control group,all the physiological indexes of rat femoral bone decreased in tailsuspended group and Chinese medicine treatment group(P【0.05).The strength and rigidity of rat femoral bone decreased in tail-suspended group(P【0.01).the maximum load and rigidity coefficient also decreased with the inereasing toughness coefficient in the control group(P【0.01). i2i After the countermeasure of Chinese herbal compound,each biomcchanical indexes showed the tendency of increasing in Chinese medicine treatment group,and theses indexes were close to those of the blank control group(P【0.05),which indicated that(he bone loss caused by simulated weightlessness was improved.Conclusions:Chinese herbal compound for tonifying kidney could effectively prevent the bone loss and have some enhancements on the bone hiomechanical properties. 展开更多
关键词 Chinese HERBAL compound SIMULATED weightlessness Rat FEMORAL bone BIOMECHANICAL properties
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Effect of long-term weightlessness on retina and optic nerve in tail-suspension rats 被引量:6
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作者 Hong-Wei Zhao Jun Zhao +10 位作者 Lian-Na Hu Jing-Nan Liang Yuan-Yuan Shi Chuang Nie Chang-Yu Qiu Xin-Shuai Nan Yu-Xin Li Fu-Lin Gao Yi Liu Yu Dong Ling Luo 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2016年第6期825-830,共6页
AIM: To evaluate the effect of long weightlessness on retina and optic nerve in suspension (TS) rats. -term tail METHODS: A stimulated weightlessness model was established by suspending rats tail. After 12wk, the... AIM: To evaluate the effect of long weightlessness on retina and optic nerve in suspension (TS) rats. -term tail METHODS: A stimulated weightlessness model was established by suspending rats tail. After 12wk, the ultrastructure and the number of optic nerve axons were observed by transmission electron microscope. The number of survival retinal ganglion cells (RGCs) was calculated by fluorescent gold retrograde labeling. Retina cells apoptosis was detected by TUNEL staining. The function of optic nerve and retina was evaluated by the visual evoked potential (VEP) and oscillatory potentials (Ops). RESULTS: The optic nerve axons were swollen and sparsely aligned, and the lamellar separation and myelin disintegration occurred after 12wk in TS rats. The density of optic nerve axons was 32.23±3.92 ( ys 37.43±4.13, P= 0.0145), the RGCs density was 1645 ±46 cells/mm^2 (vs 1867±54 cells/mm^2 F=0.0000), the incidence rate of retinal cells apoptosis was 5.38%±0.53% ( vs 4.75%±0.54%, P= 0.0238), the amplitude of VEP-P100 was 15.43±2.14 μV (vs 17.67±2.17 μV, P=0.0424), the latency of VEP-P100 was 69.05v5.34ms (vs 62.43±4.87ms P=0.0143) and the sum amplitude of Ops was 81.05±8.34 μV (Ys 91.67± 10.21 μV, P=0.0280) in TS group and the control group, respectively. CONCLUSION: Long-term weightlessness can induce the ultrastructural changes and functional depress of the optic nerve, as well as retinal cell damages in TS rats. 展开更多
关键词 weightlessness RETINA optic nerve tailsuspension
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Effects of Simulated Weightlessness on Tight Junction Protein Occludin and Zonula Occluden-1 Expression Levels in the Intestinal Mucosa of Rats 被引量:4
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作者 陈英 杨春敏 +4 位作者 刘庆森 郭明洲 杨云生 毛高平 王萍 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2011年第1期26-32,共7页
This study investigated the tight junction(TJ) protein expression of the intestinal mucosa in a rat tail-suspension model under simulated weightlessness.Twenty-four Wistar rats were randomly divided into three group... This study investigated the tight junction(TJ) protein expression of the intestinal mucosa in a rat tail-suspension model under simulated weightlessness.Twenty-four Wistar rats were randomly divided into three groups:CON group(n=8),control; SUS-14 d group(n=8),tail-suspension for 14 days; SUS-21 d group(n=8),tail-suspension for 21 days.Occludin and Zonula Occluden-1(ZO-1) expression levels were determined by immunohistochemical analysis and mRNA fluorescent quantitative PCR.Plasma levels of diamine oxidase(DAO) and d-lactate were determined using enzymatic spectrophotometry.Immunohistochemical results for occludin and ZO-1 showed disruption of the TJs in the intestinal mucosa in SUS-14 d and SUS-21 d groups.The expression levels of occludin and ZO-1 in SUS-21 d group were lower than those in SUS-14 d group,and significantly lower than those in CON group(Occldin:0.86±0.02 vs 1.01±0.03 vs 1.63±0.03 and ZO-1:0.82±0.01 vs 1.00±0.02 vs 1.55±0.01,P〈0.01).Moreover,the levels of plasma DAO and d-lactate in SUS-21 d group were higher than those in SUS-14 d group,and significantly higher than those in CON group(DAO:27.58±0.49 vs 20.74±0.49 vs 12.94±0.21 and d-lactate:37.86±0.74 vs 28.26±1.01 vs 17.76±0.91,P〈0.01).There were significant negative correlations between occludin or ZO-1 expression levels and DAO(r2=0.9014,r2=0.9355,P〈0.01) or d-lactate levels(r2=0.8989,r2=0.9331,P〈0.01).Occludin and Zo-1 were reduced in intestinal mucosa both in mRNA and protein levels in the rat tail-suspension model.The significant negative correlations between expression levels of TJs and plasma levels of DAO or d-lactate support the hypothesis that intestinal permeability is increased due to a decrease in TJ protein expression during tail-suspension from 14 days to 21 days. 展开更多
关键词 simulated weightlessness TAIL-SUSPENSION model tight junction(TJ) protein WISTAR
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EFFECT OF SIMULATED WEIGHTLESSNESS ON REPRODUCTION OF ADULT MALE RATS
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作者 周党侠 邱曙东 +1 位作者 王志勇 张洁 《Journal of Pharmaceutical Analysis》 SCIE CAS 2006年第2期146-148,共3页
Objective To study the effects of simulated weightlessness induced by tail-suspension on reproduction in adult male rats and its mechanisms. Methods Twenty Spraque-Dawley adult male rats were randomly divided into two... Objective To study the effects of simulated weightlessness induced by tail-suspension on reproduction in adult male rats and its mechanisms. Methods Twenty Spraque-Dawley adult male rats were randomly divided into two groups: the experimental group and control group. Rats in the experimental group were tail-suspended for 14 days. After the treatment, the weight and morphology of testis, the quantity and quality of sperm, the level of serum testosterone and the apoptosis rate of testicular cells were observed. Results Compared with the control, the testicular weight, the quantity and quality of sperm, the level of serum testosterone significantly decreased (P<0.05) while the apoptosis rate of testicular cells significantly increased (P<0.05) in tail-suspended rats. In addition, hematoxylin and eosin (HE) staining showed that seminiferous tubules atrophied, spermatogenic cells decreased, seminiferous epithelial cells disintegrated and shed, and the lumina were azoospermic. Conclusion Simulated weightlessness induced by tail-suspension has a harmful effect on male reproduction of adult rats by increasing the apoptosis of testicular cells. 展开更多
关键词 simulated weightlessness TAIL-SUSPENSION RAT APOPTOSIS TESTIS
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THE MORPHOLOGICAL CHANGES IN MUSCLE SPINDLES AND ALTERATIONS IN CELL ACTIVITY OF THE RATS' RED NUCLEUS AFTER 2 WEEKS' SIMULATED WEIGHTLESSNESS
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作者 朱永进 樊小力 +1 位作者 吴苏娣 李强 《Journal of Pharmaceutical Analysis》 SCIE CAS 2006年第2期149-152,共4页
Objective To study the morphological changes of soleus muscle spindle and electrical activity of neurons in Red Nucleus(RN) of the rat after 2 weeks' simulated weightlessness, and to reveal the interaction between... Objective To study the morphological changes of soleus muscle spindle and electrical activity of neurons in Red Nucleus(RN) of the rat after 2 weeks' simulated weightlessness, and to reveal the interaction between proprioceptive inputs of muscle spindles and reciprocal alterations in RN under simulated weightlessness. Methods Twenty female rats were exposed to weightlessness simulated by tail-suspension for 14 days (SW-14d). Body weight(200-220g) matched female rats were control group(Con). The morphological changes in isolated muscle spindle of soleus muscle, the discharges of red nucleus neurons were observed after 14d tail-suspensions by silver staining and extracellular recording respectively. Results Compared with control group ,the nerve ending of muscle spindle in SW-14d was distorted, degenerated and dissolved; the diameters of intrafusal fibers and capsule in equatorial region of soleus muscle spindles were diminished(P<0.05). The spontaneous cell activity and discharge of RN neurons (spikes/s) induced by afferent firing from muscle spindles after injection of succinylcholine were reduced after 2 weeks' simulated weightlessness respectively (18.44±5.96 vs. 10.19±6.88, 32.50±8.08 vs. 16.86±5.97, P<0.01). Conclusion The degeneration of muscle spindle induced by simulated weightlessness may be one of the causes that led to alterations in discharges of RN. 展开更多
关键词 simulated weightlessness muscle spindles red nucleus ELECTROPHYSIOLOGY
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Fos expression in the medullary visceral zone following transient decrease of blood pressure in rats under simulated weightlessness
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作者 宿长军 暴军香 +1 位作者 饶志仁 张立藩 《Journal of Medical Colleges of PLA(China)》 CAS 2000年第1期32-36,共5页
Objective: To observe Fos expression after transient decrease of blood pressure in catecholaminergic neurons of the medullary visceral zone(MVZ) in simulated weightlessness rats. Methods: Simulated weightlessness was ... Objective: To observe Fos expression after transient decrease of blood pressure in catecholaminergic neurons of the medullary visceral zone(MVZ) in simulated weightlessness rats. Methods: Simulated weightlessness was abtained by tail suspension for 4 weeks, and transient decrease of blood pressure was induced by intravenous injection of sodium nitroprusside. Fos expression in catechlaminergic neurons of MVZ were visualized by an immunohistochemical double-labeling technique with anti-Fos and anti-tyrosine hydroxylase (TH) antibodies. Results: The decrease of blood pressure in the simulated weightlessness rats resulted in Fos expression in many neurons of the medulla oblongata, and they were primarily localized in the MVZ. In the MVZ, Fos-positive neurons were concentrated in the nucleus of the solitary tract (NTS) and ventrolateral region of the medulla (VLM). On the other hand, the numbers of Fos-positive neurons in MVZ were smaller than that of control rats (treated with tail suspension or intravenous injection of sodium nitroprusside only). Although some TH-positive neurons were found to be Fos-positive, the proportion of TH/Fos double-labeled neurons was much lower than that of the control rats; intensity of TH-like immunoreactivity was also reduced. Conclusion: The decrease of Fos-positive neurons and proportion of catechlaminergic neurons expressing Fos protein may result from decrease of parasympathetic activity in the simulated weightlessness rats. 展开更多
关键词 MEDULLARY VISCERAL zone simulated weightlessness cardiovascular modulation IMMUNOHISTOCHEMISTRY
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Effects of electrostimulation and administration of succinylcholine on the expression of Fos protein in mesencephalic periaqueductal gray matter of rats after simulated weightlessness
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作者 Yongjin Zhu Sudi Wu +2 位作者 Xiaoli Fan Xinai Song Linping Xu 《Neural Regeneration Research》 SCIE CAS CSCD 2006年第1期22-25,共4页
BACKGROUND: Expression of Fos in neurons of periaqueductal gray (PAG) is used to reflect the excitability. However, changes of expression of Fos in neurons of PAG are caused by injured electrostimulation after simu... BACKGROUND: Expression of Fos in neurons of periaqueductal gray (PAG) is used to reflect the excitability. However, changes of expression of Fos in neurons of PAG are caused by injured electrostimulation after simulated weightlessness, and the relationship between pretreatment and injection of succinylcholine has not been determined yet. OBJECTIVE : To investigate the changes of expression of Fos in PAG induced by injured electrostimulation pretreatment and injection of succinylcholine at 2 weeks after simulated weightlessness.DESIGN: Observational and controlled animal study.SETTING: Department of Physiology, Medical School, Xi'an Jiaotong University; Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education. MATERIALS: A total of 24 adult female SD rats, of clean grade and weighing 180-220 g, were selected in this study. METHODS: The experiment was completed in the Experimental Animal Center of Xi'an Jiaotong University.① All rats were randomly divided into 2 groups according to body mass: simulated weightlessness group and control group with 12 in each group. And then, each group was also divided into 3 subgroups: electrostimulation group, succinylcholine-pretreatment group and succinylcholine-injection group with 4 in each subgroup. ②The model of weightlessness was simulated by tail-suspended female rats, which were described and modified by Cheng Jie. Rats in normal control group were given the same interventions as simulated weightlessness group except for tail-suspended. ③ Experimental method: The rats in electrostimulation group were given nociceptive stimulus by a pair of subcutaneous electrodes inserted into 1 and 5 claw of left hindlimb. The stimulus (current: 10 mA; duration: 1 ms; interval: 1 s) lasted for 30 minutes. The rats in succinylcholine-pretreatment group received stimulus after intravenous administration of succinylcholine, rats in succinylcholine-injection group were not given stimulus, just received succinylcholine. ④ All rats were perfused and fixed after 2 hours from the end of stimulation. The brains were removed, and serial frozen sections of midbrain were stained using immunocytochemical method, observed and taken photos under light-microscope. The number and morphological characters of Fos-immunoreactive (Fos-IR) neurons in ventrolateral part of PAG were investigated. MAIN OUTCOME MEASURES: The alterations in number and morphological characters of Fos-IR neurons in ventrolateral PAG of all rats.RESULTS: A total of 24 rats were involved in the final analysis. ① The morphological changes of Fos-IR neurons: The expressions of Fos in ventrolateral part of PAG were observed in both control and simulated weightlessness groups rats after being given nociceptive stimulus. As compared with control group, Fos-IR neurons in simulated weightlessness group were dyed lightly, cellular integrity was impaired, and cellular verge was unclear. ② The numbers of Fos-IR neurons: In control group, the numbers of Fos-IR neurons in ventrolateral part of PAG in simulated weightlessness group were obviously lower than succinylcholine-pretreatment group, but obviously higher than succinylcholine-injection group (46.94±3.38, 71.06±8.96 and 35.04±4.62, respectively, P 〈 0.05). In 14-day simulated weightlessness group, the numbers of Fos-IR neurons in electrostimulation group were also obviously lower than succinylcholine-pretreatment group, and obviously higher than succinylcholine-injection group (27.77±3.27, 32.91±2.99 and 11.75±1.00, respectively, P 〈 0.05). The numbers of Fos-IR neurons in all subgroups in control group were obviously higher than those subgroups in simulated weightlessness group. Compared with electrostimulation group, the percentage of expression of Fos in ventrolateral part of PAG responsed to nociceptive stimulus after administration of succinylcholine (SCH) was increased to 51.83% in control group and 18.51% in simulated weightlessness group.CONCLUSION :① The expression of Fos in neurons in ventrolateral part of PAG were increased by the pretreatment of SCH before nociceptive stimulus.② Nociceptive stimulus could increase the expression of Fos in neurons in ventrolateral part of PAG. ③ The numbers of Fos-IR neurons in ventrolateral part of PAG were decreased obviously after 2-week simulated weightlessness. 展开更多
关键词 Fos Effects of electrostimulation and administration of succinylcholine on the expression of Fos protein in mesencephalic periaqueductal gray matter of rats after simulated weightlessness
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Physiological effects of weightlessness: countermeasure system development for a long-term Chinese manned spaceflight 被引量:11
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作者 Linjie Wang Zhili Li +6 位作者 Cheng Tan Shujuan Liu Jianfeng Zhang Siyang He Peng Zou Weibo Liu Yinghui Li 《Frontiers of Medicine》 SCIE CAS CSCD 2019年第2期202-212,共11页
The Chinese space station will be built around 2020. As a national space laboratory, it will offer unique opportunities for studying the physiological effects of weightlessness and the efficacy of the countermeasures ... The Chinese space station will be built around 2020. As a national space laboratory, it will offer unique opportunities for studying the physiological effects of weightlessness and the efficacy of the countermeasures against such effects. In this paper, we described the development of countermeasure systems in the Chinese space program. To emphasize the need of the Chinese space program to implement its own program for developing countermeasures, we reviewed the literature on the negative physiological effects of weightlessness, the challenges of completing missions, the development of countermeasure devices, the establishment of countermeasure programs, and the efficacy of the countermeasure techniques in American and Russian manned spaceflights. In addition, a brief overview was provided on the Chinese research and development on countermeasures to discuss the current status and goals of the development of countermeasures against physiological problems associated with weightlessness. 展开更多
关键词 COUNTERMEASURE PHYSIOLOGICAL effects of weightlessness effect evaluation LONG-TERM MANNED SPACEFLIGHT
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EFFECT OF SIMULATED WEIGHTLESSNESS ON THE RESPONSE CHARACTERISTICS OF HUMAN BRAIN
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作者 魏金河 官志强 严拱东 《Science China Chemistry》 SCIE EI CAS 1989年第11期1329-1341,共13页
In order to systematically investigate the effects of simulated weightlessness on thefunction state of human brain, 15° head-down tilt (HDT) was used to simulate weightless-ness, and the response changes of event... In order to systematically investigate the effects of simulated weightlessness on thefunction state of human brain, 15° head-down tilt (HDT) was used to simulate weightless-ness, and the response changes of event-related EEG power spectra, medium-frequencysynchronous potentials and slow-waves were examined in the present study. It was foundthat HDT had characteristic effects on the above EEG responses, suggesting that the ef-fects mainly occurred in the brain’s regulatory system, therefore, resulting in changes ofthe brain function state. 展开更多
关键词 SIMULATED weightlessness response characteristics of brain EEG power spectrum EVENT-RELATED POTENTIAL SLOW POTENTIAL
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A Comprehensive Method for the Optimization of Cement Slurry and to Avoid Air Channeling in High Temperature and High-Pressure Conditions
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作者 Yanjun Li Wandong Zhang +3 位作者 Jiang Wu Yuhao Yang Chao Zhang Huanqiang Yang 《Fluid Dynamics & Materials Processing》 EI 2023年第5期1237-1248,共12页
Air channeling in the annulus between the casing and the cement sheath and/or between the cement sheath and formation is the main factor affecting the safe operation of natural gas wells at high temperatures and press... Air channeling in the annulus between the casing and the cement sheath and/or between the cement sheath and formation is the main factor affecting the safe operation of natural gas wells at high temperatures and pressures.Prevention of this problem requires,in general,excellent anti-channeling performances of the cement sheath.Three methods to predict such anti-channeling performances are proposed here,which use the weightless pressure of cement slurry,the permeability of cement stone and the volume expansion rate of cement sheath as input parameters.Guided by this approach,the anti-channeling performances of the cement slurry are evaluated by means of indoor experiments,and the cement slurry is optimized accordingly.The results show that the dangerous transition time of the cement slurry with optimized dosage of admixture is only 76 min,the permeability of cement stone is 0.005 md,the volume shrinkage at final setting is only 0.72%,and the anti-channeling performances are therefore maximized.The effective utilization of the optimized cement slurry in some representative wells(LD10–1-A1 and LD10–1-A2 in LD10–1 gas field)is also discussed. 展开更多
关键词 High temperature and high pressure cement slurry anti-channeling weightlessness pressure PERMEABILITY volume shrinkage
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Distribution of ^3H—nicotine in Rat Tissues Under the Influence of Simulated Microgravity 被引量:6
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作者 PARIMAL CHOWDHURY MICHAEL E. SOULSBY AND JAMES N. PASLEY (Department of Physiology and Biophysics, University of Arkansas for Medical Scienses, Little Rock, Arkansas 72205, USA) 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1999年第2期103-109,共7页
Rat tail suspension offers a useful model to reproduce physiologic responses to weightlessness.The present study was conducted in the head-down-tilt(HDT) rat model to assess changes in metabolism of body tissues emp... Rat tail suspension offers a useful model to reproduce physiologic responses to weightlessness.The present study was conducted in the head-down-tilt(HDT) rat model to assess changes in metabolism of body tissues employing 3H-nicotine. Twelve male rats were used in the study. Half of the rats were tail suspended at 30°for two weeks on a 12/12 light/dark cycle. During this period,body weight, food and fluid intakes were measured. At term, animals were anesthetized and injected IV withe a solution contaming 4 microuries of micotine. After 90 min the animals were sacrificed, exsanguinated and tissues (brain,blood,trachea,salivary gland,lung,heart,esophagus,spleen, kidneys and testes) were harvested. The distribution of 3H-nicotine per gram of each tissue was determinded and ealeulated as percent of total injected radioactivity. Final body weights of suspended ammals were significantly (P < 0.0 5) lower than those of eontrols(309±21 vs 350±11g). 3HNicotine waw retained in greatest amounts by the kindneys, followed inorder by salivary glands, spleen, and gastrointestinal tissues. compared to non-suspended control, the tissue retention of nicotine in suspended animals was decreased in the following tissues:esphyagus (25 %), aorta (25%). fundus (25%), trachea (22%), adrenals (18%), spleen (17 %), and pancreas (12 %). The decreased retention of mcotine in tissues from suspended animals may be indicative of the fluid shifts and changes in blood flow to those tissue beds. The lack of differnces in nicotine retention in liver and kidney between control and suspended groups may implicate a normal metabolic function of these organs even under simulated weightlessness. 展开更多
关键词 GRAVITATION Animals Male NICOTINE RATS Rats Sprague-Dawley Research Support Non-U.S. Gov't Tissue Distribution Tritium weightlessness Simulation
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Acclimation during spaceflight:effects on human emotion 被引量:3
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作者 Qing Liu Ren-Lai Zhou +2 位作者 Xin Zhao Xiao-Ping Chen Shan-Guang Chen 《Journal of Medical Colleges of PLA(China)》 CAS 2016年第3期162-167,共6页
Recently,studies on the extent to which spaceflight affects the psychology of individuals has received attention.In order to reveal the mental challenges that humans face in space,we need practical viewpoints to integ... Recently,studies on the extent to which spaceflight affects the psychology of individuals has received attention.In order to reveal the mental challenges that humans face in space,we need practical viewpoints to integrate the psychological effects,behavior,performance and the environment itself for space exploration.The present review discusses the individual variables related to space psychology and manned spaceflight,in addition to their growing trends.These items include patterns of emotional changes in extreme environments and the approaches to evaluating emotions.Moreover,the review concludes with suggested future research on emotion during spaceflight and its analogs.These data and information are needed to plan for the exploration of the Moon and Mars,along with contributions to the construction of the international space station(ISS) and astronaut training. 展开更多
关键词 Space flight weightlessness EMOTION PHYSIOLOGY
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Corrosion Rate of Hydrogenation to C110 Casing in High H_2S Environment 被引量:1
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作者 张智 LI Changjin +1 位作者 ZHANG Jiyin SHI Tahe 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第6期1081-1083,共3页
The corrosion behavior of C110 bushing at high temperature and high pressure with a high H2S / CO2 was studied, and a basis for the materials selection of sour gas well bushing was provided in H2S, CO2 and saline coex... The corrosion behavior of C110 bushing at high temperature and high pressure with a high H2S / CO2 was studied, and a basis for the materials selection of sour gas well bushing was provided in H2S, CO2 and saline coexisting environment. Under acidic condiction, hydrogen atoms greatly entered into the material and caused the material properties changed. Weight loss method was used to study the corrosion rate of hydrogen charging samples and original untreated samples in simulated oil field environment. PAR2273 electrochemical workstation was used to examine the electrochemical performance of samples untreated, hydrogen charging after reacting in autoclave. The corrosion product film was observed through SEM. The experimental results show that sample with hydrogen charging has a much more obvious partial corrosion and pitting corrosion than the untreated blank sample even the downhole corrosion speed of bushing is increased after being used for a period of time. Polarization curve shows the corrosion tendency is the same between sample with or without hydrogen charging and corrosion tendency is reduced by corrosion product film. A layer of dense product film formed on the surface of samples provides a certain protective effect to the matrix, but cracked holes which will accelerate partial corrosion of the sample were also observed. 展开更多
关键词 electrochemical hydrogen charging H28/CO2 weightlessness oil casing ELECTROCHEMICALPROPERTIES high temperature and high pressure acidic environment
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Several Theoretical and Applied Problems of Human Extreme Physi­ology:Mathematical Modeling 被引量:1
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作者 Grygoryan R.D. 《Journal of Human Physiology》 2021年第2期57-70,共14页
Human cardiovascular system(CVS)and hemodynamics are critically sensitive to essential alterations of mechanical inertial forces in directions of head-legs(+Gz)or legs-head(-Gz).Typically,such alterations appear durin... Human cardiovascular system(CVS)and hemodynamics are critically sensitive to essential alterations of mechanical inertial forces in directions of head-legs(+Gz)or legs-head(-Gz).Typically,such alterations appear during pilotage maneuvers of modern high maneuverable airspace vehicles(HMAV).The vulnerability of pilots or passengers of HMAV to these altering forces depends on their three main characteristics:amplitude,dynamics,and duration.Special protections,proposed to minimize this vulnerability,should be improved in parallel with the increasing of these hazardous characteristics of HMAVs.Empiric testing of novel protection methods and tools is both expensive and hazardous.Therefore computer simulations are encouraged.Autonomic software(AS)for simulating and theoretical investigating of the main dynamic responses of human CVS to altering Gz is developed.AS is based on a system of quantitative mathematical models(QMM)consisting of about 1300 differential and algebraic equations.QMM describes the dynamics of both CVS(the cardiac pump function,baroreceptor control of parameters of cardiovascular net presented by means of lumped parameter vascular compartments)and non-biological variables(inertial forces,and used protections).The main function of AS is to provide physiologist-researcher by visualizations of calculated additional data concerning characteristics of both external and internal environments under high sustained accelerations and short-time microgravity.Additionally,AS can be useful as an educational tool able to show both researchers and young pilots the main hemodynamic effects caused by accelerations and acute weightlessness with and without use of different protection tools and technics.In this case,AS does help users to optimize training process aimed to ensure optimal-like human tolerance to the altered physical environment.Main physiological events appearing under different scenarios of accelerations and microgravity have been tested. 展开更多
关键词 Cardiovascular system HEMODYNAMICS Baroreflexes ACCELERATIONS weightlessness Simulation
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SPACE BIOMEDICAL STUDIES IN CHINA
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作者 YANG Tian-de(Institute of Space Medico-Engineering, Beijing 100094) 《空间科学学报》 CAS CSCD 北大核心 1998年第S1期87-93,共7页
Chinese scientists paid great attention to the study about space life science in 1996-1997.Several biomedical experiments in this field were completed in Chinese recoverable satellites or in a Russian biosatellite. Th... Chinese scientists paid great attention to the study about space life science in 1996-1997.Several biomedical experiments in this field were completed in Chinese recoverable satellites or in a Russian biosatellite. The effect of microgravity and space radiation on Chinese silkworm eggs, plants, seeds and tomato DNA mutation was investigated in space. Head down bed rest of human body was applied to simulate weightlessness to study cardiovascular function, electrogastrogram,thermoregulation on the ground. Space motion sickness was also studied by means of swinging, optokinetic stimulation on the ground. 展开更多
关键词 MICROGRAVITY Simulated weightlessness SPACE medicine ANIMAL model SPACE motion SICKNESS
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SPACE LIFE SCIENCE IN 2000-2001
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作者 YANG Tiande SHEN Xianyun GU Dingliang XIAO Zhijun 《空间科学学报》 CAS CSCD 北大核心 2002年第z1期129-150,共22页
Chinese scientists studied some of the problems in the field of space life science and achieved success in the area during 2000-2001. Space biological experi ments were carried out in the orbit and the results of grou... Chinese scientists studied some of the problems in the field of space life science and achieved success in the area during 2000-2001. Space biological experi ments were carried out in the orbit and the results of ground studies on protein crystallization, space radiation, space motion sickness were introduced in this paper. The influences of simulated weightlessness on the brain-function, the car diovascular, endocrine hormones, immunity, skeletal and muscle systems were presented. In addition, gravity medicine and space environment medicine, as well as countermeasures to space deconditioning, such as the traditional Chinese medicine, were also reported. 展开更多
关键词 SPACE BIOLOGY experiments SPACE motion sickness Cardiovas cular system Brain function SIMULATED weightlessness SPACE environment medicine SPACE radiation Protein CRYSTALLIZATION
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THE TRACTION PROBLEM IN ELASTODYNAMICS
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作者 谷安海 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1992年第11期1067-1076,共10页
In continuum mechanics. Cauchy's six equationsare incomplete[1] and the famous Cauchy's laws of motionand TT =Twhere ρx, ρb , T and divT are continuous are also incomplete[2]. The first six equations are inc... In continuum mechanics. Cauchy's six equationsare incomplete[1] and the famous Cauchy's laws of motionand TT =Twhere ρx, ρb , T and divT are continuous are also incomplete[2]. The first six equations are incomplete because the geometrical representation of deformation at a given point is as yet incomplete[3], and the last two laws are incomplete because b,T and divT are frame-indifferent, but ρx is not, and T is a symmetric, as Cauchy interpreted himself. Therefore, we say, the last two laws can't accommodate to the asymmetric tensor.The purpose of this paper is to complete Cauchy 's laws of motion by postulating an asymmetric tensor for the underlying traction field of 3-dimensional space on a general framing. 展开更多
关键词 TRACTION weightlessness ASYMMETRIC TENSOR
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Advances in China Space Medical Experiment Research
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作者 CHEN Hailong LIU Zhaoxia +18 位作者 WANG Lidong DING Bai SHI Liujia WANG Chunyan MI Tao YU Hongqiang ZHAO Rui WANG Honghui CHEN Chao QU Lina MA Honglei JIANG Changhua LI Yongzhi WEI Ming LI Zhili XU Chong ZANG Peng CAO Ping LI Yinghui 《空间科学学报》 CAS CSCD 北大核心 2022年第4期786-794,共9页
In 2021,China Space Station(CSS)was assembled and constructed in-orbit,which provided a broad space platform for space medicine and space life sciences research.Space medicine focuses on the systematic risks that rest... In 2021,China Space Station(CSS)was assembled and constructed in-orbit,which provided a broad space platform for space medicine and space life sciences research.Space medicine focuses on the systematic risks that restrict long-term manned spaceflight.It carries out systematic research on the impact and countermeasure technology of long-term weightlessness on astronauts’health,space radiation on astronauts’health,behavior and ability,advanced on-orbit monitoring and medical disposal technology,and traditional space medical application technology by the space medicine experiment platform on human body and cell.It has accumulated valuable data on space environmental effects and human factors research,established a“human system risk”research system,obtained new knowledge and discoveries of space medicine,and explored countermeasure technologies of new characteristics.Moreover,a series of achievements have been made in the basic research on the mechanism of the special space environmental effect,which provides a solid foundation for the implementation of space missions. 展开更多
关键词 Space medical experiment weightlessness RADIATION Behavior Traditional medicine
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Body Fluid Changes, Cardiovascular Deconditioning and Metabolic Impairment Are Reversed 24 Hours after a 5-Day Dry Immersion
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作者 Mickael Coupe Elena Tomilovskaya +8 位作者 Francoise Larcher Bertrand Diquet Liudmila KhPastushkova Inesa BKozlovskaya Irina MLarina Guillemette Gauquelin-Koch Vladimir AKulchitsky Marc-Antoine Custaud Nastassia MNavasiolava 《Open Journal of Nephrology》 2013年第1期13-24,共12页
Dry immersion is an effective and useful model for research in physiology and physiopathology. The focus of this study was to provide integrative insight into renal, endocrine, circulatory, autonomic and metabolic eff... Dry immersion is an effective and useful model for research in physiology and physiopathology. The focus of this study was to provide integrative insight into renal, endocrine, circulatory, autonomic and metabolic effects of dry immersion. We assessed if the principal changes were restored within 24 h of recovery, and determined which changes were mainly associated with immersion-induced orthostatic intolerance. Five-day dry immersion without countermeasures, and with ad libitum water intake, standardized diet and a permitted short daily rise was performed in a relatively large sample for this experiment type (14 healthy young men). Reduction of total body water derived mostly from extracellular compartment, and stabilized rapidly at the new operating point. Decrease in plasma volume was estimated at 20% - 25%. Five-day immersion was sufficient to impair metabolism with a decrease in glucose tolerance and hypercholesterolemia, but was not associated with pronounced autonomic changes. Five-day immersion induced marked cardiovascular impairment. Immediately after immersion, over half of the subjects were unable to accomplish the 20-min 70° tilt;during tilt, heart rate and total peripheral resistance were increased, and stroke volume was decreased. However, 24 hours of normal physical activity appeared sufficient to reverse orthostatic tolerance and all signs of cardiovascular impairment, and to restitute plasma volume and extracellular fluid volume. Similarly, metabolic impairment was restored. In our study, the major factor responsible for orthostatic intolerance appeared to be hypovolemia. The absence of pronounced autonomic dysfunction might be explained by relatively short duration of dry immersion and daily short-time orthostatic stimulation. 展开更多
关键词 Physical Inactivity Modeled weightlessness Water-Electrolyte Balance Body Fluid Compartments Orthostatic Intolerance
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Design and Implementation of Fingerprint Identification System Based on KNN Neural Network
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作者 Israa Ghazi Dakhil Ali Abdulhafidh Ibrahim 《Journal of Computer and Communications》 2018年第3期1-18,共18页
Fingerprint identification and recognition are considered popular technique in many security and law enforcement applications. The aim of this paper is to present a proposed authentication system based on fingerprint ... Fingerprint identification and recognition are considered popular technique in many security and law enforcement applications. The aim of this paper is to present a proposed authentication system based on fingerprint as biometric type, which is capable of recognizing persons with high level of confidence and minimum error rate. The designed system is implemented using Matlab 2015b and tested on a set of fingerprint images gathered from 90 different persons with 8 samples for each using Futronic’s FS80 USB2.0 Fingerprint Scanner and the ftrScanApiEx.exe program. An efficient image enhancement algorithm is used to improve the clarity (contrast) of the ridge structures in a fingerprint. After that core point and candidate core points are extracted for each Fingerprint image and feature vector have been extracted for each point using filterbank_based algorithm. Also, for the matching the KNN neural network was used. In addition, the matching results were calculated and compared to other papers using some performance evaluation factors. A threshold has been proposed and used to provide the rejection for the fingerprint images that does not belong to the database and the experimental results show that the KNN technique have a recognition rate equal to 93.9683% in a threshold equal to 70%. 展开更多
关键词 FINGERPRINT CORE Point and CANDIDATE CORE POINTS Filterbank_Based Algorithm Weightless Neural Network KNN
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