An experimental study on flowrate and stability of a type of control valve of 600MW supercritical steam-turbine was presented by measuring instruments of static, dynamic pressure and vibration in self-designed test rig. The investigation shows that flow coefficient is 30% up more than that of the control valve of GX-1 type used widely in domestic power plants now, as small-medium lifts. If the relative lift (h/D) is less than 20%, the valve can always work steadily in all the pressure ratios. When the h/D is between 20% to 24%, big vibration of valve stem occurs if the pressure ratio is between 0.7 to 0.8. When h/D is more than 25%, relatively great vibration happens in a wide range of pressure ratios of 0.4 to 0.85.

An experimental study on flowrate and stability of a type of control valve of 600MW supercritical steam-turbine was presented by measuring instruments of static, dynamic pressure and vibration in self-designed test rig. The investigation shows that flow coefficient is 30% up more than that of the control valve of GX-1 type used widely in domestic power plants now, as small-medium lifts. If the relative lift (h/D) is less than 20%, the valve can always work steadily in all the pressure ratios. When the h/D is between 20% to 24%, big vibration of valve stem occurs if the pressure ratio is between 0.7 to 0.8. When h/D is more than 25%, relatively great vibration happens in a wide range of pressure ratios of 0.4 to 0.85.

An experimental study on flowrate and stability of a type of control valve of 600MW supercritical steam-turbine was presented by measuring instruments of static, dynamic pressure and vibration in self-designed test rig. The investigation shows that flow coefficient is 30% up more than that of the control valve of GX-1 type used widely in domestic power plants now, as small-medium lifts. If the relative lift (h/D) is less than 20%, the valve can always work steadily in all the pressure ratios. When the h/D is between 20% to 24%, big vibration of valve stem occurs if the pressure ratio is between 0.7 to 0.8. When h/D is more than 25%, relatively great vibration happens in a wide range of pressure ratios of 0.4 to 0.85.

Objective To establish a method for the in-vitro culture of astrocytes from cerebral cortex of neonatal rats.Methods Astrocytes were isolated from cerebral cortex of the neonatal SD rats aged 24 hours,and then were cultured in the high-glucose DMEM medium with 10% fetal bovine serum added.The morphological features of astrocytes were examined under inverted microscope.The growth of the third generation of astrocytes was observed with counting plate method and methyl thiazolyl tetrazolium (MTT) assay.Results The astrocytes from cerebral cortex of neonatal rats grew well,the astrocytes showed typical morphological features,and no other kinds of cells was found.Conclusion A simple and practical in-vitro culture method for rats astrocytes is established.

Objective To analyze the stress state of magnetic attachment in mandibular complete overdenture supported by nature roots and implant, and to provide neference for designing of clinical prosthodentics. Methods Three-dimensional finite models (model,Ⅱ,Ⅲ)of three groups of mandibular overdentures depending on the different location of the implant and natural tooth root, placing three pairs of magnetic attachment, were constructed by application of CT scanning,computer photo processing system,and Solidworks finite element model building software.The natural teeth and implant neck bone stress of the models in three groups under different stress were calculated and compared.Results The stress of the bone around the implant in the area of molar teeth in model with both sides of the implants under oblique load (Model Ⅱ)was significantly increased compared with the model with one side of the implant (Model Ⅲ). The supporting bone stress of oblique load was increased compared with the vertical load;among them under the oblique load at one side’ s molar teeth, the stress of the bone around the implant in the area of molar teeth in modelⅠ,modelⅡ and model Ⅲ was increased about 30%, 43%,and 55%.Conclusion When there only one nature teeth remain,two implants should be at least added, one in the area of opposite cuspid, and the other in the area of molar teeth of the same side. The magnetic attachment is better than other kinds of attachment in preventing the damage of abutment when it suffers inclined load.

This retrospective analysis showed that the most frequent pathogen causing bacterial liver abscess was Klebsiella pneumoniae in 138 patients.Compared with the patients without diabetes mellitus,it was found that:( 1 ) the percentage of diabetic patients having typical abdominal pain was lower ( P ＜ 0.05 ) ; ( 2 ) neutrophilic granulocytosis was more marked,but albumin and hemoglobin levels were lower in diabetic patients( P＜0.05 ) ; ( 3 )more diabetic patients were complicated with urinary tract infection and suffered from septicemia( P＜0.05 ) ; (4) the clinical course of treatment in diabetic patients was much more prolonged( P＜0.05 ).

Objective To investigate the mediating effect of the positive and the negative strategy of cognitive emotion regulation on the relationship between life events and suicide ideation among college students,as well as the moderating effect of social support on the mediation model.Methods Participants were 2 471 college students in Hunan province,and they completed the Adolescent Self-rating Life Events Check List,the Cognitive Emotion Regulation Questionnaire, the Social Support Scale for university students and the Suicide Ideation Questionnaire for university students .Results Negative strategy of cognitive emo-tion regulation played a mediating role between life events and suicide ideation among college students (β=0.17, t=8.43, P<0.01).Mediating effect quoted 0.28×(0.18-0.05U).Social Support (U) played a moder-ating role on the second path of mediation (β=-0.05, t=-2.47, P<0.05) .When U changed one unit,medi-ating effect changed 0.05 unit.Conclusion Life events influence suicide ideation through negative strategy, and with social support increasing,the effect of negative strategy on suicidal ideation weakened.

Objective To evaluate the significance of high-frequency oscillatory ventilation(HFOV) used in acute hypoxic respiratory failure(AHRF) children,failing to conventional ventilation.Methods This was a retrospective study of AHRF children ventilated by HFOV from January 2011 to September,2013.All patients were initially treated by conventional mechanical ventilation (CMV),and changed to be treated by HFOV if the patient met to one of the following criteria after the CMV parameters of PIP ＞ 30 mmH2O(1cmH2O =0.098 kPa) or PEEP ＞ 10 cmH2O with FiO2 100％ ∶ (1) SpO2 ＜ 90％ or PaO2 ＜ 60 mmHg (1 mmHg =0.133 kPa) ; (2) severe respiratory acidosis (PaCO2 ＞ 80 mmHg) ; (3) serious air leakage (mediastinal emphysema or pneumothorax).The following parameters were recorded:patient's gender,age,living PICU time,CMV ventilation time,HFOV ventilation time.We reviewed ventilation parameter settings (MAP,△P,F,FiO2),oxygenation index(PaO2/FiO2,OI),arterial blood gas,heart rate,blood pressure at different time points including late CMV(H0),2 h after HFOV(H2),6 h after HFOV(H6),12 h after HFOV(H12),24 h after HFOV (H24) and 48 h after HFOV (H48),respectively.Various indexes at different time points were compared between survival group and death group,oncology group and no-oncology group.Results PaO2 at H2 compared with H0 had significant improvement[76.9(61.9 ～ 128.0) mmHg vs 50.1 (49.5 ～68.0) mmHg,P =0.006] . PaO2/FiO2 at H2,H48 had significant improvement compared with those at H0,H24 [94.9(66.8 ～ 138.9) mmHg vs 68.0(49.5 ～86.8) mmHg,P=0.039; 135.0(77.6～240.0) mmHg vs 90.7 (54.6 ～161.7) mmHg,P =0.023)].All children's systolic pressure,diastolic blood pressure,heart rate at various time points had no difference (P ＞0.05).Compared to death group(n =14),PaO2/FiO2,OI at H6,H12,H24,H48 in survival group (n =9) had significant improvement(P ＜ 0.05).Compared to oncology group (n =10),OI at H2,H6 in no-oncology group(n =10) had significant improvement [(19.2 (13.9 ～ 26.6) vs 33.8 (19.7 ～ 48.3),P =0.049 ; 16.0(8.4 ～27.1) vs 28.9(20.9 ～38.9),P =0.027)],and mean airway pressure between two groups at H2,H6,H12 had significant improvement(P ＜ 0.05).Mortality had no significant differcence between two groups (4/10 vs 10/13,P =0.086).Conelusion HFOV used in children with AHRF which had failed with CMV ventilation can improve the patient's PaO2 and OI.Heart rate and blood pressure are stable during HFOV treatment.Oncology group patients needed higher initial MAP to improve oxygenation than no-oncology group patients when changed to HFOV treatment,but the mortality showed no difference between two groups.

Objective To establish and validate a standard method using flow cytometry (FCM)in human ABO blood group antibody (Ab) detection. Methods Sera samples from 52 blood donors were incubated with standardize red blood cells (RBCs), and anti-A/B antibody (IgM/IgG) was measured by indirect flow cytometry after adding secondary isotype-specific fluoresce labeled Ab. The results were compared with those by using ELISA reader. Results The changes of anti-A/B IgM measured by both methods correlated well and an overall correlation coefficiency of 0.730 for IgM was obtained by Spearman's rank testing (P＜0.05). FCM showed better specificity, sensitivity and reproducibility over ELISA reader. In blood group A samples (n = 16) or B samples (n = 16) ,the antirespectively. IgG blood group Ab could only be detected in blood group O sera. Conclusion Compared with traditional methods,FCM is a more objective method to offer accurate detection of natural ABO blood group Ab (IgM/IgG) and allowed semi-quantitative measurement of antibody levels.

Objective To explore the efficacy and safety of endoscopic nasal vestibule cysts,lip gingival trench path nasal vestibule excision and low temperature plasma radiofrequency ablation under nasal endoscope in the treatment of nasal vestibule cyst.Methods From January 2013 to December 2017,ninety patients with nasal vestibule cyst admitted in Taiyuan Central Hospital were selected. According to different surgical methods,the patients were divided into nasal endoscope nasal vestibule cyst group( A group,26 cases),cleft lip gingival vestibule cyst excision group(B group,36 cases),low temperature plasma radiofrequency ablation group under nasal endoscopy( C group, 28 cases). The efficacy and safety of the three types of operation were compared. Results The operation time [(15.5 ± 3.6) min] and wound healing time [( 2. 3 ± 0. 9 ) d] in A group and the operation time [( 16. 3 ± 4.5)min],wound healing time[(2.1 ± 0.5)d] in C group were all significantly shorter than those in B group,the differences were statistically significant(t=5.268,4.698,5.624,4.267,all P<0.05).The amount of bleeding in C group[(9.3 ± 0.6)mL] was the least,followed by A group[(12.2 ± 1.7)mL],and the difference among the three groups was statistically significant(t=8.256,7.254,all P<0.05).The postoperative wound VAS score among the three groups was statistically significant(F=12.674,P<0.001),and the VAS score in C group[(1.6 ± 0.7)points]