Transistor amplifier is the key and difficult points in the teaching of medical electronics,however,most of the teaching materials on this content is insufficient.Meanwhile,medical students have little knowledge of engineering,so it is difficult for them to grasp the related knowledge.We introduced ‘ superposition theorem’ into the relevant teaching.Teaching practice proved that this reform made it easier for medical students to have an in-depth understanding of the content and better teaching effect was achieved.

Objective To compare the success rate, operation time, complication rate and the degree of tolerance of two kinds of endoscopic placement of small intestine decompression tube. Method 68 intestinal obstruction patients treated with transnasal ileus tube were randomly divided into 2 groups, group A and group B, 34 cases in each. Patients in group A were treated by endoscopic placement, while in group B placement was guided by nasal endoscope. Results The catheterization success rate and complications between the two groups have no statistical significance (P > 0.05) while the differences of catheter operation time (P < 0.05) and placement tolerance (P < 0.01) have statistical significance. Conclusion Endoscopic placement of small intestinal decompression tube has clinical application value while placement guided by nasal endoscope has certain advantages.

Objective: To explore the diagnostic value of combined detection of blood osteopontin (OPN) and matrix metalloproteinase-9 (MMP-9) for in-stent restenosis (ISR) in patients after percutaneous coronary intervention (PCI). Methods: A total of 142 patients who received post-PCI coronary angiography (CAG) in our hospital were studied. The patients were divided into 2 groups based on if there were ISR condition: ISR group,n=21and Non-ISR group,n=121. The blood levels of OPN and MMP-9 were detected upon the follow-up CAG conduction and the basic clinical information with biochemical indexes were compared between 2 groups. Results: Blood levels of OPN and MMP-9 were signiifcantly higher in ISR group than those in Non-ISR group,P<0.001. Multivariate logistic regression analysis revealed that elevated levels of OPN and MMP-9 were the independent risk factors for post-PCI ISR occurrence (OR=2.861 and OR=3.343,P<0.01). The ROC area of OPN and MMP-9 for predicting post-PCI ISR occurrence were 0.821 and 0.887,P<0.001. Taking the optimal cut off value of OPN at 3.68 ng/ml and MMP-9 at 415.24 ng/ml, the combined detection could increase the sensitivity of detection (90.48%) and the negative predictive value (98.06%). Conclusion: Blood levels of OPN and MMP-9 are closely related to ISR occurrence in post-PCI patients, combined detection has certain predictive value for ISR occurrence, especially for negative predictive value.

Objective To evaluate the applicant effect of improved flushing suction method for SpyClass choledochoscope operation. Methods Seventy-three patients who underwent SpyGlass choledocho-scopy from February 2013 to January 2015 were enrolled. Negative pressure biopsy channel was used in group A(n= 34)during conducting SpyGlass choledochoscopy with the tube directly connected to the conveying pipe and combined with duodenoscope suction.In group B(n= 39),the biopsy channel of disposable syringe jacket was first connected to a delivery catheter,then the negative pressure pipe was put in the injector coat, combined with duodenoscope suction. Adverse reactions,theⅠ image acquisition time after the placement of SpyGlass delivery catheter to pancreaticobiliary duct,the total operation time,and the occurrence of compli-cations after operation were recorded. Results Sinus bradycardia,arrhythmia,agitation occurred in 7 cases (20. 6%),5 cases( 14. 7%),and 10 cases( 29. 4%) respectively in group A,those were 1 case (2. 6%),0 case(0/ 39),2 cases(5. 1%)respectively in group B with significant difference(P<0. 05). The time to acquire a clear image and the total operation time in group A were 6. 2 min and 24. 9 min,and 3. 3 min and 16. 8 minutes in B group with significant difference(P<0. 05),postoperative cholangitis oc-curred in 5 cases in group A(14. 7%),1 case(2. 6%)in group B with significant difference(P<0. 05). Conclusion New irrigation and suction method has obvious advantages in the SpyGlass system.

ObjectiveTo analyze the status of DACH1 gene promoter methylation and explore its association with the expression of DACH1 gene promoter methylation and clinical significance of endometrium carcinoma(EC).Methods From February 2004 to August 2008,a total of 80 EC tissue samples with comprehensive surgical pathology staging were collected and used for this study.Twenty normal endometrium tissues in 2008 were abtained from the fractional curettage because of dysfunctional uterine bleeding as control.All samples were confirmed pathologically.Methylation specific PCR (MSP) was performed to detect the promoter methylation of DACH1 gene,and analyze its influence on the expression of DACH1 and the relationship between DACH1 promoter methylation and clinicopathological factors in EC.DACH1 protein expression was detected by western blot.Chi-square test and Pearson test were used for statistical analysis.ResultsThe rate of promoter methylation of DACH1 gene in the EC tissues was significantly higher than that in the normal endometrium issues (30％ vs.5％,P ＜ 0.05).There was an association between the expression of DACH1 and DACH1 gene promoter methylation ( r =- 0.30,P ＜ 0.01 ).There was statistical difference between the methylation of DACH1 and the pathological grade ( P ＜ 0.05 ) or histological type ( P ＜0.05).But DACH1 gene methylation was not related with the age,stage,myometrial invasion depth and lymphnode metastasis (P ＞ 0.05 ).Conclusions DACH1gene promoter methylaion could lead to a decrease or absence in the DACH1 expression in EC.The promoter methylation of DACH1 gene may induce the inhibition of DACH1 expression,which might be one of the mechanisms of DACH1 gene inactivation in human EC.

Objectives To measure the microstructural differences in the brains of participants with amnestic mild cognitive impairment ( aMCI) and compare with a control group using a magnetic resonance diffusion tensor imaging ( DTI) technique with fully automated image analysis tools. Methods A standardized clinical and neuropsychological evaluation was conducted on each subject 31 participants (15 participants with aMCI, 16 healthy elderly adults) underwent magnetic resonance imaging (MRI)-based DTI. To control the effects of anatomical variation, the diffusion images of all participants were registered to standard anatomical space. Voxel-by-voxel comparisons showed significant regional reductions in white matter regions of fractional anisotropy (FA) in the participants with aMCI as compared with the controls. Results Significantly decreased FA value measurements (P<0. 001) were observed in the right frontal white matter in participants with aMCI. Moreover, there was a statistically significant difference between the patients with aMCI and controls in considering the small regions of bilateral superior frontal gyrus white matter (P < 0.001). Conclusions White matter damage of frontal lobe may play an important role in histopathologic changes associated with amnestic mild cognitive impairment

A new urine analysis core module based on high performance 32-bit microprocessor and high precision color sensor was presented. A novel optical structure and a specific circuit were applied to improve measurement precision and temperature was used to compensate for results in this core module. The information of urine test peice, such as all original data and color RGB value, reflectivity, semi-quantitative level, etc. can be output. The results showed that the measuring precision was about 95% or above with ideal stability and reliability using this presented core module, which can be conveniently applied in various urine analyzers, and can greatly decrease the cost of urine analyzers in development and production.
Color ; Equipment Design ; Microcomputers ; Reproducibility of Results ; Temperature ; Urinalysis ; instrumentation ; methods

Objective To evaluate accuracy,safety and clinical practicality of three measurements for the length of biliary stent.Methods A total of 120 patients with indwelling biliary stents were randomly divided into group A,B and C by the admission time,who then received endoscopic guide wire measurement (Group A),cutting knife measurement (Group B) and formula measurement (Group C) for biliary stent length.Results There were no statistical significance in sex,age,type of primary disease and biliary stent materials (P＞0.05).Operation time in group C (9.4 ± 2.47 min) was shorter than that in group A (15.8±1.71 min) and B (16.2 ± 2.22 min) with significant difference (P＜0.05).There was no significant difference in the incidence of postoperative cholangitis [7.5％ (3/40) VS 5.0％ (2/40) VS 5.0％ (2/40)]or the measurement accuracy of biliary stent length [100.0％ (40/40) VS 95.0％ (38/40) VS 97.5％(39/40)] (P＞0.05).Conclusion Three stent length measurements are accurate and safe,but formula measurement has more advantage in clinical practicality.

Purpose Recently the incidence of bone and joint degeneration is increased,with the increasing of cardiovascular disease complication.This study aims to utilize realtime three-dimensional echocardiography (RT-3DE) in evaluating left ventricular remodeling index (LVRI),to guide treatment and improve the survival rate.Materials and Methods Fifty-seven cases of healthy volunteers (normal control group) and sixty-seven patients with bone and joint degeneration (research group) were respectively divided into two subgroups according to the age.Both groups underwent conventional echocardiography and RT-3DE.The LVRI,left ventricular end diastolic volume index (LVEDVI),left ventricular mass index (LVMI),left ventricular end systolic volume index (LVESVI) and left ventricular ejection fraction (LVEF) measured by different methods were analyzed,and the differences and correlations between groups and within each group were compared.Results The age of normal control group and research group was not significantly different (P＞0.05).The LVMI and LVRI in research group were significantly higher than those in the normal control group with same age (P＜0.05).The LVEDVI,LVMI and LVRI measured by two-dimensional echocardiography and M-mode echocardiography were higher than those measured by RT-3DE,and the difference was statistically significant (P＜0.05).Bland-Altman agreement analysis showed good agreement of measured LVRI using 2D echocardiography and RT-3DE.Conclusion Patients with bone and joint degeneration have left ventricular remodeling.RT-3DE can accurately assess LVRI with the advantages of convenience and lack of radiation,which can be widely used in clinic.

Objective To explore the role of brain-derived neurotrophic factor (BDNF) in pathogenesis of autism. Methods 12.5 d pregnantWistar rats were injected sodium valproate (VPA) 600 mg/kg or normal saline (NS). Their newborn rats were observed ethologically.The expression of BDNF was measured in their temporal cortex with immunohistochemical stain. Results Compared with NS group, VPAgroup expressed less body mass (P<0.05), eyes opening delay (P<0.05), poorer coordination response (P<0.05), slower taxis response (P<0.05). The number of social behavior decreased (P<0.05), latency increased (P<0.05), duration shortened (P<0.05), repetitive activities increased(P<0.05). Purkinje cells reduced in cerebellum. The expression of BDNF increased significantly in temporal cortex 1 d, 7 d and 14 dpostnatally (P<0.01), but decreased 35 d and 49 d postnatally (P<0.01). Conclusion BDNF plays a role in the pathogenesis of autism.