1. On-line detecting of transformer winding deformation based on parameter identification of leakage inductance
Academic Journal of Xi'an Jiaotong University 2007;19(1):24-28
Transformers are required to demonstrate the ability to withstand short circuit currents. Over currents caused by short circuit can give rise to windings deformation. In this paper, a novel method is proposed to monitor the state of transformer windings, which is achieved through on-line detecting the leakage inductance of the windings. Specifically, the mathematical model is established for on-line identifying the leakage inductance of the windings by applying least square algorithm (LSA) to the equivalent circuit equations. The effect of measurement and model inaccuracy on the identification error is analyzed, and the corrected model is also given to decrease these adverse effect on the results. Finally, dynamic test is carried out to verify our method. The test results clearly show that our method is very accurate even under the fluctuation of load or power factor. Therefore, our method can be effectively used to on-line detect the windings deformation.
2.On-line detecting of transformer winding deformation based on parameter identification of leakage inductance
Zhiguo HAO ; Baohui ZHANG ; Peng LI
Journal of Pharmaceutical Analysis 2007;19(1):24-28
Transformers are required to demonstrate the ability to withstand short circuit currents. Over currents caused by short circuit can give rise to windings deformation. In this paper, a novel method is proposed to monitor the state of transformer windings, which is achieved through on-line detecting the leakage inductance of the windings. Specifically, the mathematical model is established for on-line identifying the leakage inductance of the windings by applying least square algorithm (LSA) to the equivalent circuit equations. The effect of measurement and model inaccuracy on the identification error is analyzed, and the corrected model is also given to decrease these adverse effect on the results. Finally, dynamic test is carried out to verify our method. The test results clearly show that our method is very accurate even under the fluctuation of load or power factor. Therefore, our method can be effectively used to on-line detect the windings deformation.
3.Simultaneous Determination of Peoniflorin, Campanulin and Ferulic Acid in Kangmin Granules by HPLC
Gaijin XUE ; Yunli ZHAO ; Jie HAO ; Xiaoxia GAO ; Zhiguo YU
China Pharmacy 2005;0(23):-
OBJECTIVE: To establish an HPLC method for simultaneous determination of peoniflorin,calycosin and ferulic acid in Kangmin granules.METHODS: The separation was performed on a Kromasil C18 column (250 mm?4.6 mm,5 ?m),and the mobile phase consisted of methanol-acetonitrile-0.4% phosphonic acid (20 ∶ 10 ∶ 70) with flow rate of 1.0 mL?min-1.The detection was performed at wavelength of 254 nm.Column temperature was room temperature and the injection volume was 10 ?L.RESULTS: The linear ranges of peoniflorin,calycosin and ferulic acid were 180~3 600 ?g?mL-1(r=0.999 2),4.6~92.0 ?g?mL-1(r=0.999 1) and 8.0~160.0 ?g?mL-1(r=0.999 4),respectively.The average recoveries were 98.3%(RSD=1.8%,n=9),99.0% (RSD=2.0%,n=9) and 100.5%(RSD=1.1%,n=9),respectively.CONCLUSION: The method is simple,accurate,sensitive and reproducible for the quality control of Kangmin granules.
4.Effect evaluation of acupoint massage and auricular point sticking cowherb seeds on blood pressure of hypertensive patients
Hongxia LIN ; Tong HUANG ; Xiaoling LI ; Zhiguo ZHONG ; Linduan HAO
Chinese Journal of Practical Nursing 2013;(9):38-40
Objective To observe the treatment effect of acupoint massage and auricular point sticking of cowherb seeds on blood pressure of hypertensive patients.Methods 100 cases of hypertensive patients were randomly divided into the observation group and the control group,50 cases in each.The observation group was given routine application of antihyportensive drags combined with acupoint massage and auricular point sticking of cowherb seeds.The control group received routine drug therapy.The blood pressure changes were compared between the two groups before and after treatment.Results The systolic blood pressure and diastolic blood pressure of both groups were lower after treatment compared with those before treatment.The total effective rate of blood pressure control was 98% in the observation group,88% in the control group,which showed no significant difference.Symptom control results showed that the total effective rate of the observation group was higher than that of the control group.Conclusions Acupoint massage and auricular point sticking of cowherb seeds in hypertensive patients can be an auxiliary pressure relief means,it can not only effectively lower blood pressure,but show good effect in alleviation of headache,vertigo,irritability.
5.Effects of Chinese herbal medicine Jinqi Jiangtang Tablet on serum matrix metalloproteinase-9 level and its expression in peripheral blood monocytes of rats with diabetes mellitus.
Hao WANG ; Lin SHEN ; Zhiguo WANG ; Yi CAO
Journal of Integrative Medicine 2011;9(4):442-446
Objective: To observe the effects of Jinqi Jiangtang Tablet, a compound Chinese herbal medicine, on serum matrix metalloproteinase-9 (MMP-9) level and MMP-9 expression in peripheral blood monocytes of rats with streptozocin-induced diabetes. Methods: Thirty Wistar rats were randomly divided into 3 groups: control group, untreated group and Jinqi Jiangtang Tablet group. Diabetes in rats was induced by a single intraperitoneal injection of streptozocin (70mg/kg body weight). After model building, rats in the Jinqi Jiangtang Tablet group were administered with Jinqi Jiangtang tablets at a dose of 0.8 g/(kg·d) for 6 weeks and rats in the control group and the untreated group were treated with normal saline. After treatment, level of fasting serum glucose was detected by hexokinas method; serum MMP-9 level was tested by enzyme-linked immunosorbent assay; MMP-9 expression in peripheral blood monocytes was measured by reverse transcription-polymerase chain reaction and Western blot method. Results: After treatment, fasting serum glucose level in the Jinqi Jiangtang Tablet group was less than that in the untreated group (P<0.05). After modeling, the serum MMP-9 level of rats in the untreated group was (9.11±3.55) μg/L and that in Jinqi Jiangtang Tablet group was (8.97±3.07) μg/L, which were higher than that in the control group ((4.39±1.44) μg/L) (P<0.01). After gavage, the level of serum MMP-9 was lower in Jinqi Jiangtang Tablet group than in the untreated group (P<0.05). The expression of MMP-9 in peripheral blood monocytes in the untreated group was higher than that in the control group (P<0.05). The MMP-9 expression in peripheral blood monocytes of rats with diabetes was down-regulated by Jinqi Jiangtang Tablet (P<0.05). Conclusion: Jinqi Jiangtang Tablet can decrease the level of serum MMP-9 and down-regulate the MMP-9 expression in peripheral blood monocytes at both mRNA and protein levels in rats with diabetes.
6.Clinical application of Hawkeye VG SPECT/CT imaging in the bleeding position of lower gastrointestinal
Guoxu ZHANG ; Wenwen ZHANG ; Shanhu HAO ; Zhiguo WANG ; Tong ZHANG
Chinese Journal of Nuclear Medicine and Molecular Imaging 2013;33(5):340-342
Objective To evaluate the clinical application of Hawkeye VG SPECT/CT imaging on diagnosing and locating lower gastrointestinal bleeding using in vivo labeling 99Tcm-RBC.Methods Fiftysix patients (42 males,14 females,age ranging from 10 to 76 years) who had definite lower gastrointestinal bleeding were studied retrospectively.All patients had intravenous injection with 370 MBq 99Tcm-RBC and then underwent planar,SPECT,and CT imaging respectively in the abdomen before exploratory laparotomy.Images from SPECT and CT were fused thereafter to locate the active bleeder,if any.x2 test was performed to show the differences of diagnostic sensitivity and accuracy between planar and SPECT/CT imaging.Results In 56 patients with lower gastrointestinal bleeding,50 patients showed abnormally concentrated radionuclide activity with planar images and 52 patients showed the similar imaging pattern with SPECT/CT.Among these patients,concordant bleeding with operation findings was found in 31 patients with planar images and 48 patients with SPECT/CT images.The sensitivity and accuracy were 89.3% (50/56) and 73.8% (31/42) in planar images,and 92.9% (52/56) and 92.3% (48/52) in SPECT/CT images (x2 =0.11,P>0.05 ;x2 =4.63,P<0.05).Conclusion Hawkeye VG SPECT/CT imaging shows an effective,simple and accurate method and could be used for diagnosing and locating lower gastrointestinal bleeding.
7.The Application of Multi-slice Spiral CT with Four Step Observation Method Diagnosing Rib Fine Fracture
Zhiguo ZHANG ; Changqing ZONG ; Jun LIU ; Jin ZHONG ; Caixian HAO
Journal of Practical Radiology 2009;25(12):1796-1799
Objective To approach the value of combination mode of different CT post-processing technique in diagnosing rib fine fracture.Methods 98 patients suspected with rib fractures underwent multislice spiral CT(MSCT) scanning,and CT features of rib fractures were observed with the combination of three different images:(A)volume rendering(VR),curved planar reformation(CPR) and axial view;(B)maximum intensity projection(MIP),CPR and sxial view;and(C) VR+MIP,CPR and axial view.The results were respectively recorded.Results 265 rib fine fractures were found among 98 patients.The detecting rate of fine fractures with C group was higher than that with A group (χ~2=6.67,P<0.01) and B group (χ~2=6.75,P<0.01).Conclusion MSCT four step observation method can improve the detecting rate of rib fine fracture,that is of important clinical value.
8.Clinical effect of second-look endoscopy in patients with early gastric cancer after ESD
Lijuan CHEN ; Lin MIAO ; Zhiguo GUO ; Hongsheng HAO
China Journal of Endoscopy 2017;23(6):87-91
Objective To evaluate whether second-look endoscopy could prevent endoscopic submucosal dissection complicated with delayed bleeding and to clarify what kind of lesions that need second-look endoscopy. Methods 98 patients with early gastric cancer by histological diagnosis from Oct. 2014 to Sep. 2016 were included in this study. Mucosal damage related bleeding within 24 h after ESD was considered delayed bleeding. Clinical data of patients, lesions, surgical factors, and the incidences of bleeding before and after the second endoscopy examination were retrospectively studied. Results The en bloc resection rate of 98 patients was 100.0%, and all incisal margins were negative. No gastrointestinal perforation, death or severe complications occurred. 5.1%of the patients (5/98) occurred delayed bleeding after ESD and had been successfully stopped in a second-look endoscopy, and none received operations. No delayed bleeding occurred in follow-ups of patients with negative delayed bleeding. 40.0 % of the patients (2/5) with delayed bleeding received blood transfusion. The median time of second-look endoscopy after ESD was the second day after operation (1 ~ 3 d). The median bleeding time of 5 patients with delayed bleeding after ESD was the first day after operation (1 ~ 10 d). The median duration of surgery was 75 min (60~150 min), and the prediction success rate was 94.9 %. The results of univariate analysis showed that age [(69.6 ± 7.9) vs (60.9 ± 10.1) years old, P = 0.003] and operation time [(90.0 ± 41.0) vs (66.0 ± 42.0) min, P = 0.000] were both the risk factors in delayed bleeding and non-bleeding group. Binary Logistic regression analysis showed that operation time (OR^ =1.07; 95%CI:0.73 ~ 14.63, P = 0.010) was the only predictor of delayed bleeding after ESD. Conclusions Second-look endoscopy might be effective in preventing delayed bleeding after gastric ESD, especially within 48 hours after ESD. The operation time was an independent risk factor for delayed bleeding after gastric ESD.
9.Diagnostic value of 18 F-FDG PET/CT imaging for primary pulmonary lymphoepithelioma-like carci-noma
Guoxu LU ; Shanhu HAO ; Zhiguo WANG ; Jia GUO ; Lanlan CHEN ; Wenwen ZHANG ; Yuning LIU ; Guoxu ZHANG
Chinese Journal of Nuclear Medicine and Molecular Imaging 2015;(6):438-441
Objective To assess the diagnostic value of 18 F?FDG PET/CT imaging for primary pul?monary lymphoepithelioma?like carcinoma (LELC). Methods A total of 19 patients (10 males, 9 fe?males;average age 56.4 years) with suspected primary pulmonary LELC undergone whole?body 18F?FDG PET/CT and chest contrast CT scan were enrolled in this retrospective study. The SUVmax and uptake pat?terns of FDG, the histological types and the clinical stages were recorded. Image characteristics of contrast CT and FDG PET/CT were observed, and the diagnostic efficiency was calculated. Two?sample t test and one?way analysis of variance were used to analyze the results. Results The diagnostic sensitivity and spe?cificity of LELC were 12/13 and 4/6 for FDG PET/CT. The SUVmax of LELC lesions was significantly differ?ent from that of other lung malignant tumors or lung benign lesions (F=3.67, P<0?05). The lesion had longer diameter, lower CT density, higher SUVmax in stage Ⅳ patients, compared with that in stageⅠ-Ⅲpatients ( F=7.01, P<0.05) . The significant difference of SUVmax was found between lesions with ring up?take and lesions with other uptake types (3.94±0.67 vs 2.86±0.35; t=4.07, P<0?05). The SUVmax was higher in Schmincke tumors when compared with that in tumors of Regaud subtype ( 3. 61 ± 0. 71 vs 2. 76 ± 0?29; t=2.99, P<0.05) . Conclusion 18 F?FDG PET/CT could be an accurate method in differential diag?noses of primary pulmonary LELC.
10.Myocardial glucose metabolism and perfusion following coronary artery bypass grafting and bone marrow CD34~+ cell transplantation: Dual-isotope imaging evaluation
Guoxu ZHANG ; Shanhu HAO ; Zhiguo WANG ; Tong ZHANG ; Huishan WANG ; Xianying CHEN
Chinese Journal of Tissue Engineering Research 2010;14(1):108-111
BACKGROUND: For patients with myocardial infarction occupied most of the heart, the effect of coronary artery bridge is not obvious. Currently, myocardial and vascular regeneration by stem cells has become a focus of ischemic cardiovascular disease. Myocardial survival directly correlates with improvement of blood perfusion following stem cell transplantation.OBJECTIVE: To investigate the feasibility of ~(18)F-FDG and ~(99)Tc~m-MIBI single photon emission computed tomography imaging in assessing myocardial glucose metabolism and perfusion with old myocardial infarction after coronary artery bypass grafting (CABG) and CD34~+ stem cell transplanting. METHODS: Bone marrow was extracted from the anterior superior iliac spine 1 day before surgery. Mononuclear cells were isolated by Ficoll density gradient centrifugation. CD34~+ cells were isolated and purified by immunomagnetic bead system. Coronary artery pathological changes were examined under general anesthesia. The end-to-side anastomosis of graft vessel and coronary artery was performed. 1×10~(11)/L CD34~+ cell suspension was extracted, and injected into the surrounding and center of the infarct (blood flow/metabolism matching depletion) at 6 points, with 0.2 mL in each point. According to preoperative perfusion/metabolism imaging, myocardium segments were divided into two groups: match group: blood perfusion and metabolism images were sparse or normal, i.e. infarction or normal myocardium; mismatch group: blood perfusion image displayed depletion, but metabolism images were normal or radially distributed, i.e. surviving myocardium. ~(18)F-FDG and ~(99)Tc~m-MIBI dual-isotopic imaging were performed before and 4 months after CABG. Circumferential count profiles from ~(18)F-FDG and ~(99)Tc~m-MIBI short axis slices were generated to assess myocardial blood perfusion and glucose metabolism. RESULTS AND CONCLUSION: The 31 patients were divided into 279 segments, and 145 segments were in myocardial perfusion-metabolism mismatch (MM). ~(99)Tc~m-MIBI and ~(18)F-FDG uptake fraction was significantly increased 4 months before operation (P < 0.01); match group without transplanting had 81 segments, and the ~(99)Tc~m-MIBI and ~(18)F-FDG uptake fraction remained unchanged after operation (P > 0.05). Match group undergoing transplanting had 54 segments, and their ~(99)Tc~m-MIBI and ~(18)F-FDG uptake fraction increased remarkably 4 months after operation (P < 0.01). CABG can improve the function of survival myocardial segments, but it is helpless to infraction myocardium. The autologous CD34~+ stem cell transplantation can improve myocardial blood perfusion and glucose metabolism of the distributions of infract myocardium.