Along with the development of science and technology , microwaves are widely used in various fields .Though they have brought much convenience to people , their potential adverse health effects are becoming a concern of governments and researchers .High power microwaves ( HPMs) are widely used in high-tech and new concept weapons , increasing the chance that troops are exposed to HPM environments .It has been clearly confirmed that microwave radiation could cause varying degrees of damage to the nervous system , immune system , cardiovascular system and reproductive system under specific conditions .Therefore , it is of important significance to reduce adverse effects of HPM radiation and improve the combat capability of troops via effective medical protection while doing well in physical protection .According to the mecha-nism and characteristics of microwave radiation damage effects , recent advances in microwave radiation protection are re-viewed in this article , hoping to facilitate research on safer and better drugs .

Objective To study the pathogenic bacteria species and drug resistance rate in the intensive care unit(ICU)in county hospital to guide clinical rational use of antibiotics. Methods 263 various specimens were chosen from January 2013 to December 2013 in the ICU of Zigui County People's Hospital in Hubei Province,these were applied to perform the bacterial culture and identification,and disc AGAR diffusion method was used to test the in vitro drug susceptibility and observe the specimens distribution,pathogenic distribution and the rate of drug resistance. Results In the 263 specimens,the top three isolated were 131 sputum(49.8%),49 blood(18.6%) and 38 ascites specimens(14.4%)respectively,and the pleural effusion was the least isolated with 5(1.9%). A total of 125 strains bacteria were isolated with positive detection rate of 47.5%(125/263). In the 125 strains,80(64.0%) were Gram-negative(G-)bacilli at the pioneer position,and the top four were:Klebsiella pneumonia 23(18.4%), Acinetobacter Baumanni 19(15.2%),Escherichia coli 18(14.4%)and Pseudomonas aeruginosa 12 strains(9.6%). There were 33 strains(26.4%)of Gram positive(G+)cocci including mainly Staphylococcus aureus 25 strains(20.0%);fungi strains were 12,the least(9.6%). The drug resistance rates of the top four G- bacillus were as follows:the rate of Klebsiella pneumoniae to ampicillin sodium was the highest(100%),while its rate to imipenem,meropenem and ciprofloxacin was 0;the rates of Acinetobacter baumannii to tobramycin and ceftriaxone were very high(100%, 92.3%),while to imipenem,meropennem were much lower respectively(26.3%,15.4%);the rates of Escherichia coli to ampicillin sodium and piperacillin were relatively high(88.9%,83.3%),while the rates to amikacin,imipenem, meropennem respectively were 0;the rates of Pseudomonas aeruginosa to ceftriaxone,cefotaxime sodium were very high(both 100%),while the resistant rate to levofloxacin was 0. The G+ cocci had no drug-resistance to linezolid, teicoplanin and vancomycin;the rates of Staphylococcus aureus to azithromycin,clindamycin,erythromycin and penicillin were higher than 80%,and those of Excrement enterococcus to erythromycin,gentamycin,levofloxacin were also higher than 80%. Conclusions The ICU infection of our hospital is primarily respiratory tract infection, the pathogenic bacteria are mainly G- bacilli and the antibacterial drug resistance is very serious. Therefore it is necessary to monitor the trend of bacterial resistance closely,and according to the results of bacteria identification and drug susceptibility,the antimicrobial agents are reasonably chosen to effectively reduce and control the ICU hospital infection.

Objective To optimize the enamel electron paramagnetic resonance (EPR) spectral processing by using the EPR spectral simulation method to improve the accuracy of enamel EPR dosimetry and reduce artificial error.Methods The multi-component superimposed EPR powder spectral simulation software was developed to simulate EPR spectrum models of the background signal(BS) and the radiation- induced signal (RS) of irradiated enamel respectively.RS was extracted from the multi-component superimposed spectrum of irradiated enamel and its amplitude was calculated.The dose-response curve was then established for calculating the doses of a group of enamel samples.The result of estimated dose was compared with that calculated by traditional method.Results BS was simulated as a powder spectrum of gaussian line shape with the following spectrum parameters:g =2.00 35 and Hpp =0.65 - 1.1 mT,RS signal was also simulated as a powder spectrum but with axi-symmetric spectrum characteristics.The spectrum parameters of RS were:g(1) =2.0018,g (11) =1.996 5,Hpp =0.335 - 0.4 mT.The amplitude of RS had a linear response to radiation dose with the regression equation as y =240.74x + 76 724 ( R2 =0.9947 ).The expectation of relative error of dose estimation was 0.13.Conclusions EPR simulation method has improved somehow the accuracy and reliability of enamel EPR dose estimation.

Objective To explore the protective effects of a new military functional food NB-5 on psychological stress-induced oxidative stress .Methods Rat whiskers were completely removed to induce the oxidative stress , and the concen-trations of MDA and protein carbonyl in various organs were detected to study the damage to membrane lipid and protein . Rats were fed with NB-5 for 4 weeks, and the oxidative stress was induced by whisker cutting .Biochemical marks men-tioned above were detected to explore the protective effects of NB-5.Results and Conclusion Lipid and protein peroxida-tion occurred in the brain , heart, liver, spleen and kidney after whisker removal due to emotional stress , while the catalase ( CAT) activity decreased significantly in these organs except the spleen .In this experiment model , NB-5 showed a good free radical scavenging activity to reduce the lipid and protein peroxidation among whisker -cutting rats fed with NB-5 in ad-vance.So NB-5 can serve as a good food for soldiers in case of emergency incidents .

Objective To investigate the adverse effect of different doses of high power microwave(HPM) irradiation on oxidative stress in the brain of Wistar rats in order to contribute to establishing an animal model to evaluate protective agents which will be used for protection against microwave radiation.Methods Eighty male Wistar rats were randomly divided into 16 groups according to factor analysis.The average power density was 0,10,30 and 100 mW/cm2 and the sampling time was 6 h,1,3 and 7 d .The duration of exposure was 6 minutes for each radiation group.After exposure, the rats were sacrificed at each sampling time.Colorimetric method was used to measure the content of malondialdehyde(MDA) and protein carbonyl, the activity of GSH-px, SOD and CAT.Results The content of MDA and protein carbonyl of each radiation group was increased with the radiation dose, but decreased with the sampling time prolonged.The activity of superoxide dismutast(SOD),glutathion peroxidase(GSH-px) and catalase(CAT) in each radiation group was decreased with the radiation dose increased, and with the sampling time prolonged, but increased later.Conclusion Microwave radiation can cause oxidative stress in rats brain, as shown by the oxidative damage of lipid and protein and the decrease in the activity of antioxidant enzymes.Besides, the effect also depends on the radiation dose and sampling time.

The character of the membrane of fiber can be simulated by nonpower RC network on condition that the offset of distance between the transmembrane potential of unmyelinated nerve fiber and the resting potential of nerve fiber cell is small enough. Thus, it is possible to found the successive cable equation with external stimulation under subthreshold linear state. So far, most scholars use time-domain analysis method. In this paper are reported the method of integral transform and the analytical expression of cable equation under the stimulation of point electrical source firstly. And at the same time, computer-aided simulation of transmembrane potential of nerve fiber and analysis of the possibility of activating action potential are presented.
Action Potentials ; physiology ; Computer Simulation ; Electric Stimulation ; Humans ; Membrane Potentials ; physiology ; Models, Neurological ; Nerve Fibers, Unmyelinated ; physiology

Objective Using an adenoviral vector , the wild-type PTEN gene was transduced into activated hepatic stellate cell (HSC) in vitro and the phosphorylation status of Akt were investigated. Methods The wild type PTEN gene was transduced into activated HSC in vitro mediated by adenoviral vector. The expressions of PTEN and total Akt in HSC were measured by Western blot and Real-time fluorescent quantitation PCR. And the expressions of phosphorylated Akt (Thr308) in HSC was determined by Western blot. Results The data showed that exogenous wild type PTEN gene was successfully transduced and expressed in activated HSC in vitro. The over-expression of wild type PTEN resulted in the significant down-regulated expression of phosphorylated Akt (Thr308) in activated HSC (P < 0.01). But no significant defferences were found in the expression of total Akt in activated HSC at both transcriptional and translational levels(P>0.50). Conclusions The overexpression of wild-type PTEN can negatively regulate PI3K/Akt signaling transduction by inhibiting the phosphorylation of Akt in activated HSC in vitro.

BACKGROUND: The immature dendritic cell (imDC) can induce immunological tolerance and has widely application in the field of organ transplant. At present, the methods of inducing imDC are insufficient, so the new induction method is demanding.OBJECTIVE: To investigate the effect of sodium butyrate (SB) on the maturation and immunological function of human peripheral blood-derived imDC.DESIGN: Controlled observation and in vitro cytological trial.SETTING: Department of Hepatobiliary Surgery in the Second Affiliated Hospital of Sun Yat-sen University.MATERIALS: Five samples of human peripheral blood were obtained from the healthy volunteers (aged 20-23 years) of Sun Yat-sen University, totally 500 mL. Then peripheral blood mononuclear cells (PBMCs) and lymphocytes were isolated within 2 hours.METHODS: The experiment was carried out in the Medical Research Center of the Second Hospital Affiliated to Sun (1 mmol/L) was added for induction, while those supplemented with maturation promoting factor lipopolysaccharide (LPS)the beginning of induction, while LPS was added on the sixth day for second stimulation.MAIN OUTCOME MEASURES: Cell morphological change, flow cytometry was used to detect DC phenotype,FITC-labeled Dextran was used to detect the endocytosis of DC, the production of IL-12 was determined by means of enzyme-linked immunosorbent assay, and the proliferation of lymphocyte induced by DC was assayed with mixed lymphocyte reaction.expressions of CD80, CD83 and HLA-DR were significantly lower in the imDC of routine induction group following SB maturity promoting, compared with LPS group (P＜0.01). On the sixth day, LPS was added into the SB-induced imDC,Endocytosis of DC: The imDC of routine induction group possessed a significantly lower endocytic activity after induced by LPS, and there were extremely significant differences compared with blank control group and SB maturation Production of IL-12: The production of IL-12 in the mDC induced by LPS was significantly higher than that in control group, SB maturation promoting group and SB induction group, the mDC induced by LPS in routine induction group stimulated significantly stronger proliferation of lymphocyte (P＜0.01).

AIM: To investigate the immunological function of sodium butyrate-induced immature dendritic cells in vitro.METHODS: The human monocyte-derived dendritic cells were induced in the presence of human granulocyte macrophage-colony stimulating factor(GM-CSF) and interleukin-4 (IL-4), combined with sodium butyrate. The immunological function of sodium butyrate-induced dendritic cells was detected by the FCM, endocytic activity, T cells stimulatory proliferation capacity, and interleukin-12 (IL-12) production.RESULTS: Sodium butyrate could down-regulate the major histocompatibility complex(MHC) class II and costimulatory molecules of dendritic cells, increase the endocytic activity, induce a stage of T-cell anergey, and inhibit the T helper cell type 1-skewing factor IL-12 production. CONCLUSION: Sodium butyrate inhibits the maturation of dendritic cells and induces production of immature dendritic cells, which may help to explore the machenism of its epigenitic modification.

Objective To calculate the electric field intensity and transmembrane voltage of spherical cells and ellipsoi -dal red blood cells ( RBC) in an extremely low frequency electromagnetic field .Through this calculation , we can provide reference to the search for interaction targets and mechanics between the extremely low frequency electromagnetic field and organisms.Methods The Finite Element Method was used in the numerical computation for the spherical cell model and the ellipsoidal RBC model .Results The electric field intensity of the two types of cells on the cellular membrane was both significantly higher than the applied electric field strength , and the values of the induced field strength and transmembrane voltage varied with the direction of the electric field periodically .Conclusion The cell shape and direction of the applied electric field are not the main determinants of the cellular membrane electric field intensity and the transmembrane voltage compared with electromagnetic parameters .The distribution of the electric field intensity and transmembrane voltage are re-lated to the direction of the applied electric field.