The limitations of the currently used exercise-based counterm easures and the scientific rationale for the gravity-based countermeasures are a ddressed.Then,an overview of the physiological effects and requirements for th e two types of artificial gravity (AG),i.e.,the continuous AG provided by full -time spinning of the entire space system/habitat and the intermittent AG by i nco rporating a short-arm centrifuge into the spacecraft,is presented.Finally,sig nificance and challenge faced in future research on biochemical problems of arti ficial gravity are discussed

Objective To observe the efficacy and safety of oral ibuprofen suspension in treatment of neonatal patent ductus arteriosus. MethodsFrom January 2006 to December 2009 in our hospital,128 cases with neonatal patent ductus arteriosus were accepted as the observation group,treated with oral Ibuprofen Suspension:from January 2003 to December 2005 in our hospital,92 cases with neonatal patent ductus arteriosus were accepted as the control group,treated with lndomethacin.Efficacy and adverse reaction of two groups were compared. ResultsThe closure of the observation group was better than the control group,and the incidence of adverse events was less than the control group,the differences between two groups were statistically significant(P＜0.05). ConclusionOral ibuprofen suspension in treatment of neonatal patent ductus arteriosus had satisfactory effect and less adverse reaction,it was worthy of clinic application.

ER, and least marked when IR

Objective To study the changes of gene and protein expressions of key components of renin-angiotensin system (RAS) in myocardium of simulated weightless rats. Method Tail-suspended rats were adopted as animal model of simulated weightlessness. RT-PCR and Western blot analysis were performed to examine mRNA and protein expressions in rat myocardium, respectively. Result After 1 week tail-suspension,no obvious changes in angiotensinogen (AGT), angiotensin converting enzyme (ACE), 1a and 1b subtype of type 1 angiotensin Ⅱ receptor (AT 1aand AT 1b), key components of RAS in myocardium were observed. But after 4 weeks tail-suspension, the expressions of AGT mRNA and higher molecular weight band of AGT protein increased significantly (P

Objective To analyze the risk factors of post-operative respiratory failure in elderly cardiac carcinoma patients.Methods 28 elderly patients with respiratory failure (respiratory failure group) after the resection of cardiac carcinoma and 56 controls (control group) were studied.Preoperative respiratory function,the other complications,the site of incision,intravenous infusion,age of patients and smoking between two groups were compared by Logistic regression.Results Univariate risk factors included MVV<50% ,RV/TLC>50% ,FEV1<1.5L,PEF<70% ,DLCO<80% ,V75<70% ,the venous input,incision at chest.Multivariate logistic regression analysis identified that MVV<50% ,RV/TLC>50% ,FEV,<1.5 L,DLCO<80% were risk factors.Conclusion These results suggested that the patients with risk factors described above need more careful pre and post operative surveillance and management.

BACKGROUND: Under specially physical environment, for example weightlessness, metabolism of bone tissue may have remarkable changes; however, osteoblast is a core of bone metabolism and bone formation, so it is very sensitive to changes of gravity environment.OBJECTIVE: To observe the effects of simulated weightlessness on bone marrow stromal cell count and osteogentic capacity of weight bearing bone in rats so as to reveal the mechanism of bone loss.DESIGN : Randomized pairing and controlled study.SETTING: College of Aerospace Medicine and Department of Pathology of Stomatology College, the Fourth Military Medical University of Chinese PLA.MATERIALS: A total of 20 adult healthy male SD rats were selected in this study. At the beginning of experiment, rats based on their body mass were randomly divided into control group and suspension group with 10 in each group. Alkaline phosphatase kit was provided by Beijing Zhongsheng Bioengineering High-technological Company.METHODS: The experiment was carried out in the Department of Pathology, Collage of Stomatology, the Fourth Military Medical University of Chinese PLA from November 1999 to July 2000. Rats were randomly divided into tail suspension group and control group with 10 in each group. Rats in the tail suspension group were given tail suspension for 28 days. Their heads maintained 30° low position, and their hindlimbs freely suspended and were not given weight loading. While, rats in the control group were fed normally. At the end of experiment, bone marrow stromal cells were obtained from femur for primary and transferring cultures.MAIN OUTCOME MEASURES: Cell counting and methylthianolyldiphenyl-tetrazolium bromide (MTT) assay were used to draw growth curve of cells in primary and transferring cultures and to measure activity of alkaline phosphatase and forming quantity of mineralized nodules in vitro.RESULTS : ① Activity of alkaline phosphatase: Activity of alkaline phosphatase of cells in the primary and transferring cultures in the suspension group was lower than that in the control group, and there was significant difference between them (P＜0.05). ② Forming quantity of mineralized nodules: Forming quantity of mineralized nodules in the suspension group was less than that in the control group, and there was significant difference between them (P＜0.05). ③ Cell growth: Growth curve of femoral stromal cells in primary and transferring culture manifested as S. Doubling time of cells in the suspension group was similar to that in the control group. ④ Amount of bone marrow stromal cells in femur: Amount of bone marrow stromal cells in primary culture in the suspension group was decreased as 50% as that in the control group (P＜0.05).CONCLUSION: Under simulated weightlessness, amount of bone marrow stromal cells decreases obviously; in addition, amount of osteoblast also decreases in weight bearing bone of hindlimbs and osteogentic capacity in vitro decreases simultaneously.

Objective:To study the association of TGF?2 polymorphisms and maternal smoking with the occurrence of nonsyndromic cleft lip and palate(NSCLP). Methods:TGF?2 genes were amplified from peripheral leukocytes by means of PCR in 272 cases of nonsyndromic cleft lip with or without palate(CL/P), 251 of cleft palate only(CPO) and 312 of unrelated controls in Jilin Province, PCR products were analyzed by single-stranded conformation polymorphism(SSCP) and DNA sequencing. Maternal smoking was investigated. The association of TGF?2 polymorphisms, maternal smoking with the occurrence of CL/P and CPO was analyzed by SAS statistic system. Results:The 322 bp PCR product of TGF?2 was amplified from CL/P, CPO and control samples; SSCP analysis showed three alleles of TGF?2;sequencing results showed that allele1, allele2 and allele3 contained seven, eight and nine ACA repeats respectively. The statistic analysis showed that TGF?2 polymorphisms or maternal smoking was associated with the occurrence of CL/P and CPO respectively(P0.05).Conclusion:TGF?2 polymorphisms and maternal smoking during pregnancy are associated with the occurrence of CL/P and CPO. TGF?2 polymorphisms have no interaction with maternal smoking.

Objective To explore the early diagnosis value of C‐reactive protein (CRP) and procalcitonin (PCT ) for bacterial in‐fectious pneumonia of children .Methods A total of 101 children with bacterial infectious pneumonia ,64 children with non‐bacterial infectious pneumonia and 73 children with non‐infectious disease were selected in bacterial infectious pneumonia group ,non‐bacterial infectious pneumonia group and non‐infectious disease group respectively .Serum PCT and CRP levels were measured before treat‐ment in the three groups .With sputum culture results as gold standard for the diagnosis of bacterial infectious pneumonia ,the sensi‐tivity ,specificity ,positive predictive value ,negative predictive value ,Youden index and diagnostic accuracy of PCT ,CRP ,PCT /CRP series test and parallel test were calculated for bacterial infectious pneumonia diagnosis .Results The levels of PCT and CRP of children in bacterial infectious pneumonia group were significant higher than those of children in non‐bacterial infectious pneumonia group and non‐infectious disease group(P < 0 .05) .The sensitivity ,specificity ,positive predictive value ,negative predictive value , Youden index and diagnostic accuracy of PCT ( ≥ 0 .5 ng/mL as the best intercept point) for bacterial infectious pneumonia diagno‐sis were 0 .743 ,0 .719 ,0 .806 ,0 .639 ,0 .461 and 0 .733 .And the same values for PCT /CRP series test were 0 .604 ,0 .875 ,0 .884 , 0 .583 ,0 .479 and 0 .709 respectively .All the values were higher than those of children in non‐bacterial infectious pneumonia group and non‐infectious disease group except sensitivity .Conclusion The combination of PCT and PCT /CRP series test is ideal method for early diagnosis of bacterial infectious pneumonia with high sensitivity and specificity .

We introduced the method of computer simulation in the studies of gravitational physiology. Based on work of Melchior (1994), we developed a mathematical model that can be used to stimulate cardiovascular responses to orthostatic stress (lower body negative pressure, LBNP). The model includes 7 sub-models: the redistribution of blood, the filling of left ventricle, left ventricle working, peripheral circulation, control of heart rate (HR), control of peripheral resistance and control of venous tone. Then we simulated the changes of blood pressure (BP) and heart rate during lower body negative pressure, and the results agreed well with the results of our human experiment. By using the developed model, we also simulated the effects of hypovolemia on the BP, HR and shock index during orthostatic stress. The simulation results indicate that the cardiovascular responses to orthostatic stress change significantly when the decrease of blood volume is more than 15% of the total blood volume. However, if the amount of the decrease of blood volume is less than 5% of the total blood volume, HR and BP could be maintained in normal range by the regulation of baroreflex during LBNP. Our simulation results suggest that hypovolemia may be the main cause of orthostatic intolerance induced by weightlessness.
Adult ; Blood Pressure ; physiology ; Cardiovascular Deconditioning ; physiology ; Computer Simulation ; Heart Rate ; physiology ; Humans ; Hypotension, Orthostatic ; etiology ; physiopathology ; Hypovolemia ; etiology ; physiopathology ; Lower Body Negative Pressure ; adverse effects ; Male ; Models, Cardiovascular ; Ventricular Function, Left ; physiology ; Weightlessness Simulation ; adverse effects

Objective To summarize and analyze the dynamic change of HBsAg levels in patients with chronic Hepatitis B (CHB) after receiving nucleos(t)ide analogues (NAs) as antiviral treatment.Methods Patients who were performed quantitative Hepatitis B surface antigen(qHBsAg) from July 30, 2012 to December 30,2016 in Peking Union Medical College Hospital were retrospectively enrolled.qHBsAg, HBV DNA, HBeAg were collected and analyzed at baseline and at 192-week follow-up every 24 weeks.qHBsAg and HBeAg were assessed with chemiluminesent microparticle immuno assay(CMIA).HBV DNA was assessed with PCR and COBAS Amplicor.Results 60 patients were included.Patients in HBeAg-positive group had higher HBV DNA than that in HBeAg-negative group (P<0.05)at baseline and the two groups both were under detection limit after 48 weeks.BaselineqHBsAg in HBeAg positive-group and negative-group were (3.43±0.73) log10 IU/mL, (3.08±0.47) log10 IU/mL respectively.qHBsAg in HBeAg-positive group was higher than that in HBeAg negative-group on all follow-ups(P<0.05) except 48weeks.However on 168 weeks and 192 weeks, difference between the two groups was statistically significant(P<0.05).In HBeAg-positive group,quantitative HBeAg dropped significantly during antiviral treatment.Conclusions HBV replication can be suppressed in the process of long-term NAs treatment in CHB patients.However qHBsAg decline is not so obvious, which indicates that HBsAg cleavence is difficult,and long-term NAs therapy is still necessary.