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Objective: To study the molding process of modified Zexie plaster. Methods: Sodium polyacrylate was used as the ad-hesive, carbomer as the emulsifier, glycerol as the humectant, and gelatin as the excipient. Orthogonal screening was applied to select the optimum formula and drug loading. Results: The significance order of the influencing factors was sodium polyacrylate > drug load-ing >gelatin >carbomer, and the best preparation process was A2B2C2D2, which was determined as 2. 5% sodium polyacrylate: 3% carbomer: glycerin: 12% gelatin: soluble starch: drug loading of 70: 6: 5: 15: 3: 9 (mass ratio). Conclusion: According to the optimum process route selected by orthogonal test, three batches of samples were tested, and the results showed that the process had good repro-ducibility, which is suitable for the industrial production.
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Aerospace physiology is an important part of aerospace medicine.There are some problems existing in the current practice classes.Microlecture is a new kind of teaching methods.With its advantages, microlecture improved the teaching efficiency, and played a good role in the practice classes for undergraduate students, successfully solving part of the problems and promoting the teaching reform.The microlecture, as an auxiliary means, provides a new way for practice class of aerospace physiology.It`s suggested to be popularized in undergraduate teaching of aerospace medicine.
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In educating postgraduate students in aerospace medicine in our country, there are some deficiencies such as the course content lacking forward looking and systematicness, and students' mastery of technology or skills lacking professional characteristics, innovation and divergent thinking. Based on the original foundations, the School of Aerospace Medicine, Fourth Military Medical University, has been con-structing and improving the course system by modifying the course contents, reforming the practical teach-ings, expanding the academic communications, and managing the processes. Finally, they have achieved certain results.
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The launch of Expedition 1 to the International Space Station (ISS) opened a new era in the history of human space flight, so far fourteen Expeditions had been achieved. But the astronauts were exposed to abnormal environment such as microgravity, radiation, isolation, confinement, and misalignment of circadian rhythm during space flight. In order to reduce health risks incurred by living in space, the 59 projects have been or will be studied aboard ISS. Those researches has elucidated the rate of subregional bone loss and its recovery, characteristics of atrophy and reduced contraction function in antigravity skeletal muscle, decrease in spinal cord excitability, and relationship between reduced immune function and reactivation of some viruses. The psychological and behavior changes in a prolonged isolation and confinement condition, as well as the fast circadian rhythm inducing sleep disruption has been observed. It has been found exposure to radiation not only causing cataracts and cancers, but also damaging the reproductive organs and nervous system, and inducing genetic damage. The efficacy of countermeasures of medicine, nutrition and vibration have been validated aboard the ISS. The effective countermeasures on different systems were checked further. All of those studies and observations have made a solid foundation for developing novel countermeasures which will be more effective.
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Objective To compare the morphological differences in soleus between tail-suspended and 30-month-old rats.Methods Fourty-two male rats were randomly divided into seven groups:5 d,7 d and 14 d tail-suspended and their synchronous control groups,30-month-old group.The cross-sectional area(CSA)and percentage of MHC Ⅰ/Ⅱ fibers were measured in immunohistochemically stained sections and CSA was normalized by body weight.Results Wet weight,relative wet weight,CSA and normalized CSA in unloaded soleus decreased significantly as compared with the synchronous control.The percentage of MHC Ⅰ fibers decreased,but that of MHC Ⅱ fibers increased in unloaded soleus.The wet weight and CSA of soleus in 30-month-old rats increased,but the relative wet weight and normalized CSA reduced significantly as compared with 14-day synchronous control.The relative wet weight and normalized CSA of soleus in 30-month-old rat were similar to that of 14 d tail-suspended group.The percentage of MHC Ⅰ/Ⅱ fibers of soleus in 30-month-old rat and in 5 d,7 d,and 14 d of synchronous control groups kept constant value.Conclusion It's suggested that the atrophic process of soleus is slower in 30-month-old rats than that in the tail-suspended rates.The reduction of soleus relative wet weight and normalized CSA appears early in aged rats,but the absolute and relative wet weight of soleus decrease simultaneously in tail-suspended rats.
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Objective To set up a simple method to measure the SR Ca2+ release function in skeletal muscle strips.Methods The time from peak tension to 75 % relaxation(TR75) during intermittent tetanic contraction(fatigue contraction) of isolated musculus soleus strips was analyzed.It was prolonged rapidly,and then shortened slowly.The ratio of maximal TR75 to initial TR75(R-TR75) indicated a balance between SR Ca2+ release and uptake.If the SR Ca2+-ATPase(SERCA) activity and inhibition extent of SERCA in fatigue contraction were identical,R-TR75 should be an index for SR Ca2+ release function.Results Higher stimulation voltage or 5 mmol/L caffeine perfusion which increased the SR Ca2+ release channel open probability induced an increase of R-TR75 from 2.5 in control to 3.0.On the contrary,inhibition of SR Ca2+ release with 5 mmol/L magnesium sulfate perfusion significantly decreased R-TR75.Inhibition of SR Ca2+ release by metabolites during fatigue contraction was recovered slowly.So R-TR75 at the second fatigued contraction was reduced after 5 or 10 min of recovery,but no significant difference after 60 min of recovery.During intermittent tetanic contraction R-TR75 was increased to be 2.9 times of normal in unloaded soleus.Conclusion The above results suggest that R-TR75 during muscle strip fatigue contraction without any change of SERCA activity can indirectly reflected SR Ca2+ release function.In 2-week unloaded soleus,the enhanced R-TR75 indicates an increase in SR Ca2+ release function.
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AIM: The aim of this study was to observe the cardiac performance in 2-week or 4-week levothyroxine(T4)-induced cardiac hypertrophy and to elucidate the possible underlying mechanism of cardiac hypertrophy transition to heart failure in T4 treatment rats.METHODS: The blood pressure and pulse rate were measured by tail-cuff technique.The cardiac output and the preload-cardiac output were measured in working heart mode.The shortening of unloading contraction in cardiomyocytes was observed by an edge-detector system.RESULTS: Resting heart rate in T4 treatment rats increased significantly and the width of cardiomyocytes widened in T4 rats,but the length of cardiomyocytes had no difference compared with control values.The cardiac output in 2-week T4 group was higher than that in control group.The cardiac output increased when the preload increased from 5 mmHg to 15 mmHg.The unloading shortening amplitude at 1 Hz and 2 Hz increased in 2-week T4 group.No difference between 2-week T4 group and control group at 4 Hz was observed.When the stimulating frequency increased from 1 Hz to 4 Hz,the shortening amplitude also increased in control cardiomyocytes,but decreased in 2-week or 4-week T4 group.The shortening amplitude increased further in 4-week T4 group as compared with that in control.The time to peak shortening and time from peak shortening to 75% relaxation reduced at each frequency in 2-week and 4-week T4 group.The shortening and relaxation rates in 2-week or 4-week T4 group were higher than those in control group at 1 Hz and 2 Hz.The shortening and relaxation rate kept higher at 4 Hz in 2-week T4 group,but showed no difference with control at 4 Hz in 4-week T4 group.CONCLUSION: These above results suggest that shortening amplitude-frequency relationship of cardiomyocytes in 4-week T4 rats is earlier to be altered than cardiac performance in working heart.