Objective To study the effects of short-term and long-term exposure to extremely low frequency electromagnetic field(ELFEMF)on Morris learning and memory among rats. Methods Both younger(2-3 months old)and adult(18 months old)male SD rats were exposed to 50 Hz uniform ELFEMF with continuously adjusted intensities(0.1,1.2,1.6 mT) developed by Helmholtz coil pair for 10 days to 8 months. The levels of escape latency and the crossing annulus coefficients reflecting the behavioral changes in place navigation ability and spatial probe ability were examined by Morris water maze after exposure to ELFEMF among rats. Results The escape latency was shortened and the crossing annulus coefficients were increased compared with those of control group when the younger rats were exposed to 0.1,1.2 and 1.6 mT ELFEMF for 10 days respectively,and only revealed significant differences in 1.2 and 1.6 mT ELFEMF exposure groups compared with those of control group. In the younger rats of 1.6 mT ELFEMF exposure group with 10-day exposure ,their escape latencies were prolonged and the crossing annulus coefficients were decreased gradually and showed no significant differences compared with those of control group after the 30-day blank exposure period without ELFEMF.The younger rats of 1.2 mT ELFEMF exposure group showed significantly longer escape latency and lower crossing annulus coefficient compared those of control group after continuous 90-day exposure to 1.2 mT ELFEMF. The escape latency of adult rats in 0.1 mT ELFEMF exposure group showed no significant difference after 10-day exposure,was prolonged after 4-month exposure,and was significantly prolonged further more after 8-month exposure. Conclusion The learning and memory ability could be promoted by short-term ELFEMF exposure and impaired by long-term ELFEMF exposure for the young rats,and could be obviously inhibited by long-term ELFEMF exposure for the adult rats.

Objective: So far, CT back projection technology is already quite mature, this article is a basic research for CT back projection technology, which uses software method to realize back-projection technology, so that you can have a better under-standing of CT back-projection technology. It uses computer soflware programming to realize computer simulation of CT back-projection reconstruction: algorithm is CT back projection algorithm. While realizing back-projection reconstruction, we can choose a suitable faltering function to process received image data in finquency domain, so as to achieve the purpose of the elimination of simple back-projection arising from star-shaped artifact. Methods: The programming environment uses VC soft-ware platform integrated development environment ODE). It bases on the CT filtering back-projection reconstruction algorithm and develops a PC software of graphic user interface. By choosing the value of the various parameters related to the back-pro-jection, we can obtain different effect of back-projection reconstruction image, so that we can compare the result of different pa-rameters to get important factors which effects CT filter back-projection most. Results: We realize the simulation of image re-construction of standard phantom. The interface is easy, so makes it very convenient for deeper understanding of back-projec-tion reconstruction, at the same time the filtering function based on the frequency domain also partly eliminates the star artifact caused by reconstruction process. The reconstruction image of the standard phantom achieves the desired effect. Conclusions: The software simulation of the back-projectiun reconstruction can show the process of recoustruction clearly. By change the val-ue of the parameters, we can have a better understanding of the reconstruction algorithm, so that we can find more suitable fil-tering function.

Objective: Fetal monitoring is extremely important in perinatal care. Analysis of cardiotocogragh(CTG) can suppose if the fetus is lack of oxygen, distressed, acidosis, etc. in order to take measures timely. Methods: We have designed Meticare analysis software package to analyze 867 pieces of CTG data, and researched the relationship between short term variation (STV) and basal heart rate(BHR) by statistics, and short time monitoring analysis based on STV. Results: The amplitude of fetal heart rate curve variation(long term variation) tended to decrease when BHR increasing, with the negative correlation and regression equation STV = 9.866-0.02×BHR. Positive correlation exists between 5 and 10 mimute-STV, with the regression equation STV_(10min)=2.861-0.596×STV_(5min).Conclusion: STV calculated by 5 minutes CTG data can forecast the one by 10 minutes data as a reference demanded by Dawes & Redman criterion. If fetal doppler contains STV analysis function, out-patient fetal heart auscultation will be more significant. After 30 weeks pregnancy, with the STV decreasing, fetal distress, asphyxia, low birth weight, and even mortality increasing. BHR increasing should cause attention that STV might decrease, when monitoring with no analysis functional devices or fetal dopplars.

Objective To strengthen the capability of emergent supply in field medical point.Methods The common application program was designed by using PowerBuilder.The database program was Oracle.Results The assistant conduction and management of information were realized including the information of staff,war materials,equipment,wounded soldiers in the field medicine.Conclusion Information management system in field hospital can rapidly and accurately provide all kinds of information for users.It can be extensively applied in all levels of field hospitals.

Objective To investigate the value of the intraoperative real-time three-dimensional transesophageal echocardiography (RT 3D-TEE) in therapeutic application of surgery for the mitral valve prolapse.Methods Thirty-five patients underwent surgical treatment were diagnosed as mitral valve prolapse by 2-dimensional transthoracic echocardiography (2D-TTE),with or without ruptured chordae tendineae.RT 3D-TEE was performed for assessing the segment of prolapse and its complications before cardiopulmonary bypass and after heart resuscitation respectively.The echocardiographic results were compared with the surgical findings.Results The accuracy of RT 3D-TEE to identify segments with prolapse was significantly higher than that of 2D-TTE (91.4％ vs 82.9％,P =0.003).RT 3D-TEE was more accurate than 2D-TTE for identifying ruptured chordae tendineae,vegetation and thrombus since higher sensitivity,specificity and Youden index.Among all 35 patients,valvuloplasty was performed in 28 cases,whereas,only 7 cases underwent replacement of prosthetic valves.Three patients were benefited by accurate evaluation of therapeutic effect using RT 3D-TEE in time.ConclusionsIntraoperative RT 3D-TEE can be used to provide “ surgical view”,acquired adequate valuable information of mitral valve,and more reliable functional and anatomical assessment of the mitral valve components and its geometry.Suitable surgical intervention can be designed for improving outcomes of patients.

AIM: The effect of urotensin II (U-II) on proliferation of cultured pulmonary arterial smooth muscle cells (PASMCs) of rabbits and its mechanism are investigated. METHODS: PASMCs were isolated using explant technique. RPASMCs were incubated in serum-free medium with different concentrations of nicardipine, calcimodulin antagonist W 7, PKC inhibitor H 7 or MAPK inhibitor (PD 98059 ), with or without U-II. RPASMC proliferation was examined by MTT [3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay and by the increase in [ 3H]-thymidine incorporation into DNA. RESULTS: U-II (10 -9 mol/L-10 -7 mol/L) increased A value of PASMCs by MTT assay and [ 3H]-thymidine incorporation in PASMCs in a dose-dependent manner. U-II induced a maximal effect at a concentration of 10 -7 mol/L. A value and [ 3H]-thymidine incorporation rose 42 9% and 68 5% ( P

Objective To determine the usefulness of real time three-dimensional transesophageal echocardiography(RT-3D TEE) in the preoperative assessment of mitral valve (MV) pathology by comparing images with surgical findings and to evaluate the function of MV postoperatively. Methods Nineteen consecutive adult patients with established diagnosis of mitral regurgitation(MR) scheduled for surgical correction were enrolled. Intraoperative 2D and 3D transesophageal echocardiography(TEE) were performed. All the 3D images were compared with findings obtained from direct surgical inspection. Postoperative RT-3D TEE was performed immediately to evaluate outcomes of mitral annuloplasty. Results Superb 3D-TEE en face views of the MV were obtained in all patients. Correct diagnoses of MV pathology in agreement with the surgical findings were made in 16 of 19 patients (84. 2%), however in the remaining 3 patients, the diagnoses were incorrect despite good image quality. In one, RT-3D TEE diagnosed prolapse of A2 segment and P2 scallop,which was not confirmed at surgery, but MV degeneration and annular dilatation were observed. In another one, RT-3D TEE revealed prolapse of P3 scallop, while at surgery prolapse involved P2 and P3 with ruptured chordae. In the rest one,surgically detected prolapse of P2 was missed by RT-3D TEE. On the other hand with 2D TEE,the diagnoses correlated poorly with surgical findings,only 10 patients were accurately diagnosed (52.6%). In some patients,2D TEE was able to identify the MVP, but it had difficulty in defining the exact location of the prolapsed segment or scallop. The severity of MR decreased significantly after surgery. MV repair was successful in all patients except one(5.1%), in whom moderate to severe MR was still present and MV replacement was conducted subsequently as an alternative.Conclusions RT-3D TEE provides excellent imaging of MV components, including the anterior and posterior leaflets, as well as annulus and subvalvular structures, which can be especially helpful in planning the most appropriate surgery strategy. RT-3D TEE offers exact anatomic characteristics of mitral annuloplasty rings and bands, providing additional information for the evaluation of surgical outcomes.

Objective To evaluate the therapeutic effect of highly active anti-retroviral therapy (HAART) in treatment-na(i)ve Chinese patients with AIDS, to provide evidences for standardizing HAART.Methods Seventy-four treatment-naive AIDS patients were initiated with HAART and followed up regularly for 3 years. The clinical and laboratory data, side effects and drug resistance were observed and analyzed during the follow-up period. Results Of the 74 patients, 46 were males and 28 were females, with the average age being 42 years. The mean HIV viral load was ( 2. 2 ± 2.0 ) × 105 copies/ml and the baseline mean CD4+ T lymphocyte count was (62 ± 71 )cells/μl before treatment. After treatment for 3, 6, 12, 18,24, 30 and 36 months, the percentage of undetectable HIV viral road (less than 50 copies/ml ) was 71.6%, 83.8%, 75.7%, 77.0%, 82.4%, 81.1% and 79.7% respectively, and CD4+T lymphocyte count ascended to ( 167 ± 105), ( 177 ± 129), (238 ± 137), (290 ± 158), (304 ± 191 ), (331 ± 175) and ( 352 ± 202 ) cells/μl. The increase in amplitude of CD4+ T lymphocyte count in different periods examined was different, with the period of 0-3 months post-treatment demonstrating the most obvious augmentation ( P ＜ 0. 01 ) . The most common adverse reactions were liver function injury ( 52/74,70. 3% ), hyperlipemia (52/74, 70. 3%), hematopoietic inhibition of the bone marrow (33/74, 44. 6% ),peripheral neuritis (32/74, 43.2% ) and lipoatrophy (26/74, 35. 1%). Clinical drug resistance were found in nine patients and HIV gene mutations were detected in these patients. Conclusions Chinese treatment-naive AIDS patients have achieved good virological and immunological response to generic-drugpredominant HAART regimes with low drug resistance, but relatively more side effects.