1.Thermal Physiological Consideration of Precooling Procedures in Manned Space Craft
Xuejun YU ; Shaoyong CHANG ; Jianmin WU ; Man QIU ; De SONG ; Tiande YANG
Space Medicine & Medical Engineering 2000;13(2):90-94
Objective To explore a space craft precooling temperature at which excessive thermal stress on the crew member could be prevented or reduced in an overheated launch or reentry module. Method Five young male volunteers wearing a space suit participated in 25 tests at sea level.The space suit was either ventilated in a volume air flow rate of 100 L/min (STPD) with ambient air at temperatures (Ta) of 15℃,10℃,and 5℃,respectively,or not ventilated. Rectal (Tr),mean skin (Tsk) and mean body (Tb) temperatures were measured. Result At Ta 15℃,Tr decreased without significance (from 37.0±0.2℃to 36.7±0.3℃) in 120-min tests,whereas Tsk and Tb decreased significantly,and subjects had local cold strain whether the space suit was ventilated or not; while at Ta 10℃,Tr decreased from 37.0±0.3℃ to 36.3±0.3℃(P<0.05),subjects had a whole body cold strain,and both Tsk and Tb dropped continuously and significantly. Conclusion Ambient temperature 15℃,at which the thermal comfort states of crew was not significantly degraded,was acceptable after precooling in a space craft.
2.Study on the sweat regulation mechanism under different temperature circumstance and different intensive exercise.
Man QIU ; Jian-ming WU ; Shao-Yong CHANG ; De SONG
Chinese Journal of Applied Physiology 2005;21(1):90-94
AIMTo investigate the sweat regulation mechanism of human body.
METHODSArm muscular work was performed on bicycle ergometer by eight healthy male subjects on 20 W and 40 W work loads lasting 10 min or 20 min in 16 degrees C and 21 degrees C ambient temperature. Sweat, metabolic rate and corresponding skin and core temperature changes were measured during different periods.
RESULTSSweat varied directly with ambient temperature and there were the corresponding changes in mean skin temperature, rectal temperature and metabolic rate. And when the work load was elevated, the skin temperature at chest and metabolic rate increased as sweat increased. There were no differences in the physiological indices between 20 W 20 min and 20 W 10 min, but mean skin temperature and sweat rate during 40 W 20 min work were higher than 40 W 10 min while metabolic rate did not change. The time when chest temperature arrived at the threshold was in correspondence with obvious sweat onset. Both local skin temperature at chest and metabolic rate were significantly correlated with sweat, but the latter was stronger. The regression equation relating metabolic rate and sweat rate was compound function.
CONCLUSIONSkin temperature was important for sweat onset, and the sweat predicted model based on the metabolic rate or ambient temperature was more suitable and practical.
Adult ; Body Temperature Regulation ; physiology ; Energy Metabolism ; Environment ; Humans ; Male ; Sweating ; physiology ; Temperature
4.Clinical application and pharmacokinetic study of nanocarriers in drug delivery system
Xiao XIAO ; Jun-yu CHEN ; Cai-xia LI ; Man WU ; Jian-dang LI ; Chang-kuo SHI ; Shu-qing WU ; Wen-liang LI
Acta Pharmaceutica Sinica 2023;58(4):856-866
Nanotechnology has shown obvious advantages in the field of medical treatment and diagnosis. Through the encapsulation of nano carriers, drugs not only enhance the therapeutic effect and reduce toxic and side effects, but also become intelligent responsive targeted drug systems through the modification on the surface of nano carriers. However, due to the obstacles in relevant basic research, production conditions, cost, clinical trials, and the lack of pharmacokinetic research on various drug loading systems, few nano systems have been used in therapy. In order to solve the above problems, this paper reviewed and analyzed the research progress of nano carriers in drug delivery, including their auxiliary role and characteristics, types and functions, pharmacokinetics, application prospects and challenges.
5.Influence of temperature fluctuation on thermophilic anaerobic digestion of municipal organic solid waste.
Man-chang WU ; Ke-wei SUN ; Yong ZHANG
Journal of Zhejiang University. Science. B 2006;7(3):180-185
A laboratory-scale experiment was carried out to assess the influence of temperature fluctuation on thermophilic anaerobic digestion of municipal organic solid waste (MOSW). Heating failure was simulated by decreasing temperature suddenly from 55 degrees C to 20 degrees C suddenly; 2 h time is needed for temperature decrease and recovery. Under the conditions of 8.0 g/(L.d) and 15 d respectively for MOSW load and retention time, following results were noted: (1) biogas production almost stopped and VFA (volatile fatty acid) accumulated rapidly, accompanied by pH decrease; (2) with low temperature (20 degrees C) duration of 1, 5, 12 and 24 h, it took 3, 11, 56 and 72 h for the thermophilic anaerobic digestion system to reproduce methane after temperature fluctuation; (3) the longer the low temperature interval lasted, the more the methanogenic bacteria would decay; hydrolysis, acidification and methanogenesis were all influenced by temperature fluctuation; (4) the thermophilic microorganisms were highly resilient to temperature fluctuation.
Archaea
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cytology
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physiology
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Bacteria, Anaerobic
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cytology
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physiology
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Biodegradation, Environmental
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Cell Survival
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Cities
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Fatty Acids, Volatile
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metabolism
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Hydrogen-Ion Concentration
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Methane
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metabolism
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Refuse Disposal
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methods
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Sewage
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microbiology
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Temperature
6.Characteristics of induced atrial arrhythmias and long-term follow-up after pulmonary vein isolation in ;patients with paroxysmal atrial ifbrillation
Chenxi JIANG ; Changsheng MA ; Jianzeng DONG ; Xin DU ; Jiahui WU ; Deyong LONG ; Ronghui YU ; Ribo TANG ; Caihua SANG ; Man NING ; Songnan LI ; Chang LIU
Chinese Journal of Interventional Cardiology 2014;(4):205-209
Objective Identify the mechanism of induced atrial arrhythmias after pulmonary vein isolation (PVI) in patients with paroxysmal atrial ifbrillation(PAF), and investigate its long-term prognosis. Methods All patients with PAF undergoing PVI and induction test afterwards between Feburary 2010 and October 2010 were included. The induction protocol was rapid pacing initiated at cycle length of 250 ms with progressive shortening in a decrement of 10 ms down to 180 ms or refractoriness. Isoproterenol of 2-4μg/min was administrated as well. Inducibility was deifned as induction of atrial arrhythmia lasting >1 min. The mechanism of induced tachycardia was identiifed by activation mapping and entrainment mapping under the guidance of CARTO system. All patients were followed up by 36 months. Results Forty-nine atrial tachycardia were induced in 39 (19.7%) patients, including 35 organized atrial tachycardia (OAT) and 14 atrial ifbrillation (AF). The LA diameter was signiifcantly larger in inducible group than non-inducible group (39.5±6.6 mm vs. 36.7±5.2 mm, P=0.004). Macroreentry was the most common mechanism in induced OATs (28, 80.0%), and mitral isthmus was the most common critical site (20, 40.8%), followed by cavo-tricuspid isthmus (12, 24.5%), PV (6, 12.2%), LA septum (4, 8.2%), superior vena cava (3, 6.1%) and LA roof (1, 2.0%). Conclusions The most common mechanism of induced tachycardia by IV isoproterenol and rapid pacing is MI and CTI dependent after PVI in PAF patients, which can be succssefully eliminated by liner ablation, not increasing long-term recurrence rate.
7.Effect of acteoside on behavioral changes and endoplasmic reticulum stress in prefrontal cortex of depressive rats
Hai-Feng DENG ; Man-Li SUN ; Hao CHEN ; Xing-Hong WANG ; Qiong WU ; Quan-Zhong CHANG
Chinese Journal of Pathophysiology 2018;34(1):101-106
AIM:To explore the effect of acteoside on behavioral changes and endoplasmic reticulum stress(ERS)in prefrontal cortex of depressive rats.METHODS:Sprague-Dawley(SD)rats(n=108)were randomly divided into 6 groups:control group,model group,fluoxetine(20 mg/kg)group,low-dose(30 mg/kg)acteoside group,medium-dose(60 mg/kg)acteoside group and high-dose(120 mg/kg)acteoside group,with 18 rats in each group.The depres-sive-like rat model was established by chronic unpredictable mild stress(CUMS)combined with solitary way for 28 d.The rats in fluoxetine group and acteoside groups were treated with fluoxetine(20 mg/kg)or acteoside(30 mg/kg,60 mg/kg and 120 mg/kg)once daily by intragastric administration for 3 weeks.The rats in control group and model group were both given equal volume of saline by intragastric administration for 3 weeks.The behavioral changes were detected by the open-field test and sugar preference experiment.The protein expression of glucose-regulated protein 78(GRP78 )and C/EBP homologous protein(CHOP)was assessed by immunofluorescence and Western blot.The caspase-3 activity was measured by spectrophotometer.RESULTS:Compared with control group ,the total distance ,time spent in the center and sugar in-take were all decreased ,the expression of GRP78 and CHOP was increased ,and the activity of caspase-3 was increased in model group ,fluoxetine group and acteoside groups(P<0.05 ).Compared with model group ,the total distance ,time spent in the center and sugar intake were increased ,the expression of GRP78 and CHOP was reduced ,and the activity of caspase-3 was decreased(P<0.05)in fluoxetine group and acteoside groups.CONCLUSION:Acteoside improves de-pressive-like behaviors in depressive rats ,which may be related to the inhibition of ERS and neuronal apoptosis in prefron-tal cortex.
8.Magnetic resonance imaging findings in sporadic Möbius syndrome.
Shao-Qin WU ; Feng-Yuan MAN ; Yong-Hong JIAO ; Jun-Fang XIAN ; Yi-di WANG ; Zhen-Chang WANG
Chinese Medical Journal 2013;126(12):2304-2307
BACKGROUNDAlthough neuroradiological findings of Möbius syndrome have been reported as a result of brain and brainstem abnormalities, magnetic resonance imaging (MRI) now permits the direct imaging of the cranial nerve (CN) and branches in the orbits. This study presents the MRI findings in patients with sporadic Möbius syndrome.
METHODSProspectively, CNs were imaged in the cistern using head coils and three dimensional fast imaging employing steady-state acquisition (3D-FIESTA), yielding a 0.5 mm(2) resolution in planes of 0.8 mm thickness in seven patients with sporadic Möbius syndrome. The cavernous and intraorbital segment of the CN and the extraocular muscles (EOMs) were imaged with T1 weighting in all patients. The cavernous segment was imaged in coronal planes, while the intraorbit in quasicoronal planes were imaged using surface coils. Intraorbital resolution was 0.16 mm(2) within 2.0 mm thick planes.
RESULTSIn the seven patients, the CN were absent or showed hypoplasia in the cistern, cavernous sinus, and orbit. Abducens (CN VI) and facial (CN VII) nerves were absent on the affected sides. Unilateral CN IX (glossopharyngeal nerve) in two cases displayed dysplasia. Branches from the inferior division of CN III were observed to innervate the lateral rectus (LR) bilaterally in three cases and unilaterally in one case, and had intimate continuity with the LR muscle in two cases bilaterally and two cases unilaterally. Hypoplasia of EOMs was shown in five cases. Dysplasia of the medulla on the left side was found in one patient.
CONCLUSIONSDirect imaging of CNs and EOMs by MRI is useful in diagnosis of Möbius syndrome. It can directly demonstrate the abnormalities of the CN and orbital structures. The absence or hypoplasia of CN VI and CN VII may be the most common radiologic features in sporadic Möbius syndrome, and hypoplasia of CN IX may be an associated feature. The abnormality of EOMs and aberrant innervations in the orbit should be observed, and may be important for the study of the etiology.
Cranial Nerves ; pathology ; Humans ; Imaging, Three-Dimensional ; Magnetic Resonance Imaging ; methods ; Mobius Syndrome ; pathology ; Oculomotor Nerve ; pathology
10.Magnetic resonance imaging of unilateral vertical retraction syndrome with atypical strabismus.
Cheng-Yue ZHANG ; Feng-Yuan MAN ; Zhen-Chang WANG ; Gang YU ; Qian WU ; Yong-Hong JIAO ; Kan-Xing ZHAO
Chinese Medical Journal 2011;124(19):3195-3197
We report two patients with unilateral vertical retraction syndrome. Magnetic resonance imaging (MRI) of the orbits of the two cases showed similar size and location of the orbital structure, but with dramatically different strabismus type. MRI sagittal reconstruction of the orbits suggested that abnormal muscle tissue arised from the inferior rectus, which might be associated with retraction and narrowing of the palpebral fissure and atypical strabismus as well.
Child
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Eyelids
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physiopathology
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Female
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Humans
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Magnetic Resonance Imaging
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Male
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Oculomotor Muscles
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physiopathology
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Orbit
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pathology
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Strabismus
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pathology
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Syndrome