1.Three-dimensional finite element numerical analysis of the Ni Ti shape memory alloy clutching internal fixator
Guoping CHEN ; Yubo FAN ; Daiquan ZHANG
Journal of Medical Biomechanics 2010;25(1):36-39
Objective Clutching internal fixtor(CIF)loose and the fixed part weakly heal up are often found in orthopedic clinic.In the present paper,biomechanics methods were used to try to explain and analyze these issues,providing a helpful suggestion for the application of CIF in clinic.Method Commerical finite element models(FEM)Program ANSYS was applied to set up the finite element models of orthopedic CIF and bone tissue to analyze and evaluate the biomechanical performances of the NiTi shape memory alloy CIF.Results There is an interaction force between embracing force of CIF and resistant force of bone tissue during the orthopedic clinical treatment.The embracing force along two semi-circular arms of CIF is increasing from the open position and reached the maximum value at the open symmetry position where the deformation of the bone occurred.Conclusion It is the key to choose the force loading position during the practical treatment,as the concentration force is the main force when there is an interactive force between the bone and the CIF.
2.Content Determination of Testosterone Propionate in Testosterone Propionate Paints by HPLC
Daiquan DENG ; Bimin FENG ; Hao ZHANG
China Pharmacy 1991;0(03):-
OBJECTIVE:To establish a HPLC method for the content determination of testosterone propionate in testosterone propionate paints.METHODS:The assaying was conducted on a Kromasil C 18 column with methanol-water solution(80∶20)as mobile phase,the detection wavelength was254nm and the flow rate was1.0ml/min.RESULTS:The linear concentration range of the testosterone propionate was100~400mg/ml(r=0.9997)with average recovery rate at98.5%(RSD=0.55%).CONCLUSION:The method is simple,accurate and reproducible,and it can be used for the quality control of testosterone propionate paints.
3.Numerical study on the stability of micro-implant with different pitchs for immediate loading
Yongqiang XU ; Daiquan ZHANG ; Wentao JIANG ; Yubo FAN
Journal of Medical Biomechanics 2009;24(6):439-443
Objective To study the stability of micro-implant orthodontic anchorage(MA)with different pitch in the case of immediate loading.Method Employing 3D finite element analysis method,the stress and dis-placement distribution on the bone interface of MIA with different pitch(0.3 mm、0.5 mm、0.7 mm and 1.0 mm,respectively),which was 1.47 N loaded vertically in the major axis direction,were analyzed.Result The pitch affected the stress distribution significantly,because the maximum stress increased with the pitch decreasing and the impact of pitch on stress distribution on neck and central locations of MIA were different;to decrease the pitch could reduce the max displacement of the jaw,but the impact of pitch on displacement distribution of MIA was not significant.Condusions In the case of immediate loading.MIA with pitch 0.5 mm-0.7 mm is suggested to be selected as orthodontic anchorage in the clinic.
4.Effect of C-erbB-2 shRNA on chemosensitivity of mouse lung adenocarcinoma cells and its mechanism
Xinmei CAO ; Daiquan ZHANG ; Xu WANG ; Jiyi XIA ; Li HUANG ; Yan GAO
Journal of Jilin University(Medicine Edition) 2014;(4):777-781
Objective To investigate the effect of C-erbB-2 shRNA on chemosensitivity of mouse lung adenocarcinoma cells and its mechanism,and to find new therapy method for non-small cell lung cancer,especial lung adenocarcinoma.Methods The mouse lung adenocarcinoma Lewis cells were cultured regularly and divided into non-transfected group, pGPU6/RFP/Neo-shNC group and pGPU6/RFP/Neo-erbB-2 group. The plasmids were synthesized and transfected into Lewis cells in each group by Lipofectamine 2000.The expression levels of C-erbB-2 mRNA and protein in the cells in various groups were tested by RT-PCR and Western blotting method, respectively. The Lewis cells were divided into non- transfected group, pGPU6/RFP/Neo-shNC group, carboplatin group, pGPU6/RFP/Neo-erbB-2 group, pGPU6/RFP/Neo-shNC+carboplatin group and pGPU6/RFP/Neo-erbB-2+ carboplatin group. The apoptotic rates of the cells in each group were detected by flow cytometry;the expression levels of Bcl-2 and Bax proteins in each group were determined by Western blotting method.Results The expression levels of C-erbB-2 mRNA and protein in pGPU6/RFP/Neo-erbB-2 group were lower than those in non-transfected group and pGPU6/RFP/Neo-shNC.The apoptotic rate of the cells in pGPU6/RFP/Neo-erbB-2+carboplatin group was the highest in all of the groups (P<0.01);compared with the others, the expression of Bax protein in pGPU6/RFP/Neo-erbB-2+carboplatin group was increased, while the expression level of Bcl-2 protein was decreased.Conclusion C-erbB-2 shRNA can increase the Lewis cells’sensitivity to carboplatin.The mechanism may be that it can enhance the Lewis cells’apoptosis induced by carboplatin through increasing the expression of Bax protein and decreasing the expression of Bcl-2 protein.
5.Compliance and effectiveness of the clinical practice guidelines for enteral nutrition support in acute stroke patients with dysphagia
Yingying SU ; Daiquan GAO ; Liansheng MA ; Huanhuan FENG ; Lin WANG ; Yunzhou ZHANG ; Ling WANG ; Fang LIU ; Xiuhai GUO ; Hong CHANG ; Min XU ; Limei FAN ; Qian ZHANG
Chinese Journal of Neurology 2012;(12):843-848
Objective To implement and evaluate evidence-based guidelines for enteral nutrition support in acute stroke patients with dysphagia.Methods This study is a prospective before and after comparison study.Collected 200 acute stroke patients with dysphagia and divided them into test group (trained medical staffs) and control group(untrained medical staffs) equally according to the time order.Two groups of 100 patients were surveyed using a checklist before and after implementation of 10 guidelines about nutrition support.Before the implementation of guidelines,the staffs were enforced training,and summarized regularly.Compliances with guidelines by doctors and nurses were compared,and outcomes of patients were assessed.Results Compared with the control group,the correct implementation of the project significantly improved in the experimental group on nutritional risk screening (92.0%,64.0%; x2 =22.840),nutritional supplements selection (80.0%,48.0%; x2 =22.220),nutrition infusion methods (90%,18% ; x2 =1.040) and nutrition infusion adjustment (abdominal distension/adjusted:21/10,6/4;x2 =9.634,constipation/adjusted:41/40,57/53 ; x2 =5.122,all P < 0.05).The mortality rate,poor prognosis and length of stay in department of neurology intensive care unit and in hospital were not significant different between the experimental group and the control group.The incidence of hospital-acquired pneumonia was significantly lower in the experimental group (44.3%) than that in the control group (67.5%,x2 =7.281,P =0.007),but other patient outcomes were unaffected significantly.Conclusion Implementation of evidence-based guidelines for enteral nutrition support in acute stroke patients with dysphagia is associated with improvements in clinical quality and selected patient outcomes.
6.Correlation between quantitative electroencephalography and prognoses of coma after cardio-pulmonary resuscitation
Qinglin YANG ; Yingying SU ; Weibi CHEN ; Hong YE ; Yan ZHANG ; Daiquan GAO
Chinese Journal of Neuromedicine 2017;16(11):1158-1162
Objective To study the correlation of quantitative electroencephalography (qEEG) parameters with outcomes of adults who sustained coma after cardio-pulmonary resuscitation.Methods The clinical data of coma patients after cardio-pulmonary resuscitation,admitted to our hospital from March 2008 to August 2014 were retrospectively analyzed.Glasgow coma scale (GCS) was performed.EEG was registered and recorded at least once within 7 d of coma after cardio-pulmonary resuscitation:electrodes were placed according to the international 10-20 system,using a 16-channel lay out.The qEEG parameters defined as burst suppression ratio (BSR),brain symmetry index (BSI),[delta+theta]/[alpha+beta] ratio (DTABR) were analyzed at the same time.Follow-up was performed 3 months after onset and the outcomes of these patients were assessed by Glasgow outcome scale (GOS).The correlations of GOS scores with qEEG parameters were analyzed.Results Sixty patients with GCS scores-< 8 after cardio-pulmonary resuscitation were included.BSR1 and BSR2 were negatively correlated with GOS scores 3 months after onset (r=-0.723,P=0.000;r=-0.651,P=0.000);DTABR was positively correlated with GOS scores 3 months after onset (r=0.270,P=0.037).BSI and DTABR were not correlated with GCS scores.BSR1 and BSR2 were negatively correlated with GCS scores (r=-0.562,P=0.000;r=-0.429,P=0.001).Conclusion The qEEG parameters are correlated with outcomes after cardio-pulmonary resuscitation.
7.Diagnosis of brain death: confirmatory tests after clinical test.
Yingying SU ; Qinglin YANG ; Gang LIU ; Yan ZHANG ; Hong YE ; Daiquan GAO ; Yunzhou ZHANG ; Weibi CHEN
Chinese Medical Journal 2014;127(7):1272-1277
BACKGROUNDThe brain death confirmation tests occupy a different position in each country's diagnostic criteria (or guideline); the choices of tests are also different. China brain death criteria include clinical judgment and confirmation tests. This study aimed to confirm the preferred confirmatory test and complementary confirmatory tests.
METHODSWe did a clinical brain death determination on deep coma patients, and then divided them into brain death group and non-brain death group. According to the Chinese standards for determining brain death, both the groups accepted confirmatory tests including electroencephalograph (EEG), somatosensory evoked potentials (SEP), and transcranial Doppler (TCD). The sensitivity, specificity, false positive rate, and false negative rate were calculated to evaluate the accuracy of the confirmatory tests.
RESULTSAmong the 131 cases of patients, 103 patients met the clinical criteria of brain death. Respiratory arrest provocation test was performed on 44 cases and 32 cases (73%) successfully completed and confirmed that they have no spontaneous breathing. Of the three confirmation tests, EEG had the highest completion rate (98%) and good sensitivity (83%) and specificity (97%); TCD had followed completion rate (54%) and not good sensitivity (73%) and specificity (75%); SEP had the lowest completion rate (49%), good sensitivity (100%), and not good specificity (78%). After the combination of SEP or TCD with EEG, the specificity can increase to 100%.
CONCLUSIONSThe completion rate of respiratory arrest provocation test remains a problem in the clinical diagnosis of brain death. If the test cannot be completed, whether to increase a confirmatory test is debatable. SEP had an ideal sensitivity, and the specificity will reach 100% after combining with TCD or EEG. When a confirmed test was uncertain, we suggest increasing another confirmatory test.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Brain Death ; diagnosis ; physiopathology ; Evoked Potentials, Somatosensory ; physiology ; Female ; Humans ; Male ; Middle Aged ; Ultrasonography, Doppler, Transcranial ; Young Adult