1.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.
2.Design of electromagnetic compatibility in shelter hospital system
Peng HUANG ; Zhiguo LIU ; Jiancheng QI
Chinese Medical Equipment Journal 2015;(9):1-5
To explore the electromagnetic compatibility in the shelter hospital system to adapt it to the future complex electromagnetic environment. The factors for electromagnetic interference were analyzed, and some measures were put forward including separating the interference source from the sensitive device, setting up shielding space, applying grounding measures, eliminating interference signals by filtering and etc. The electromagnetic compatibility in the shelter hospital system was detected through electromagnetic self-compatibility test and electromagnetic environ-mental suitability test for external radio frequency. Simulations and tests proved that the failures and mal-re-sponse due to electromagnetic interference were avoided in the shelter hospital system. The electromagnetic compatibility scheme can meet the requirements of emergency medical facilities for electromagnetic protection in field conditions.
3.Urinary tract stone after kidney transplantation (report of 5 cases)
Wanling PENG ; Zhiguo ZHANG ; Guangce WANG
Chinese Journal of Urology 2001;0(10):-
Objective To study the diagnosis and trea tm ent of urolithiasis in patients after renal transplantation. Methods 5 cases of urinary tract stone in patients after renal transplantat ion were diagnosed and treated.In 1 case,the stone was a remnant of the stone in the donor kidney,in 3 cases,the stone was secondary to a sternotic ureterocysto stomy stoma,in the other case,a stent in the urinary tract was complicated by st one formation.Surgical removal of the stone with ureter-bladder reanastomosis w as carried out for 3,in one of which ESWL has failed.Conventional nonsurgical meas ures was adopted for 2. Results The patients have been f ollowed up for 1~13 years with all the patients and the transplants surviving.I n one of the patients with nonsurgical management,the transplanted kidney has al ready survived for 13 years. Conclusions The treatment o f urinary tract stone in a transplanted kidney is similar to the conventional pr inciples,relieving the block and removal of the stone.Risk factors of uric acid stone formation should be taken care of.
4.Mechanism of anti-tumor effect of dihydroartemisinin
Wenmiao PENG ; Hongxing FU ; Lifang YU ; Zhiguo RAO
Journal of International Oncology 2017;44(6):448-451
Dihydroartemisinin (DHA),the major active metabolite of artemisinin,participates in tumor progression through the following ways:forming free radicals to induce cancer cells death dependent on iron,inducing apoptosis,inhibiting angiogenesis,tumor cells invasion and metastasis,modulating muhidrug resistance,controlling intracellular Ca2+ concentration,regulating cell cycles,cell autophagy and the immune system and so on.Generally,it is considered to be a potential anti-tumor drug.
5.Application and safety of double balloon enteroscopy in patients with small bowel hemorrhage
Zhiguo GUO ; Zhaoyuan PENG ; Yi XIN ; Lin MIAO
China Journal of Endoscopy 2017;23(1):103-106
Objective To analyze the feasibility and the diagnostic yield of double-balloon enteroscopy (DBE) examinations for small bowel bleeding (SBB). Methods A retrospective analysis was conducted on 52 cases with small bowel bleeding between June 2015 and July 2016,and all was treated with DBE. therapeutic outcome, complications and follow-up were compared. Results The study included 52 patients (28 males and 24 females) with an average age of (51.0 ± 17.0) years (16~82 years) and onset time (8.3 ± 4.0) days (1~14 days) . 25 using oral route and 21 using the anal route, 1 using the colon ifstula route, a combination of using oral and anal (n=4).The bleeding source was identiifed in 40 of 52 patients (76.9%), complication rate was 5.8%(3/52), and rebleeding rate was 16.7%(2/12). The endoscopic treatments included polypectomies (n=5), argon plasma coagulation (APC, n=2), surgical treatment (n=14, 26.9%), and foreign-body extraction (n=1). Patients were diagnosed with the following:tumors (n=9, 17.3%), ulcers (n=9, 17.3%), Crohn’s disease (n=7, 13.5%), polyps (n=5, 9.6%), diverticulum (n=4, 7.7%). Patients with small bowel bleeding were followed up for a mean period of (8.3±2.0) months (range 4~10 months), 2 deaths were dying from small bowel cancer. Conclusions DBE is a safe endoscopic technique for patients with small bowel bleeding and can be safely carried out even after Roux-en-Y operation. Tumors, ulcers and Crohn’s disease are very common causes of SBB. The rebleeding rate after a negative DBE is considerable, especially small bowel vascular lesions.
6.Expendable Metallic Biliary Endoprosthesis Companied with Stereotactic Radiotherapy to Treat Malignant Biliary Obstuction
Zhiguo WU ; Qiang LI ; Liping LI ; Aiyun PENG
Journal of Practical Radiology 2001;0(06):-
Objective To evaluate the effect of treating malignant biliary obstruction by expandable metallic biliary endoprosthesis(EMBE) via percutaneous transhepatic approach companied with stereotactic radiotherapy(SRT). Methods We implanted total 19 stents via percutaneous transhepatic in 15 patients with malignant biliary obstuction, then the patients received stereotactic radiotherapy.Results The stent implanting in 15 cases was successful,and followed-up for 12 months .3 cases died in the third,fourth and eleventh month respectively without jaundice,others survied formore than one year.The survival rate for one year was 80%.Conclusion Implanting stent in bile ducts companied with stereotactic radiotherapy is an effective way in treating malignant biliary obstruction.
7.Endothelial progenitor cells combined implantation improves proliferation and suppresses apoptosis of neural stem cells and angiogenesis of MCAO/R rats
Qizhi FU ; Zhiguo QI ; Xiaofeng ZHU ; Peng XIE
Journal of Third Military Medical University 1988;0(06):-
Objective To investigate the effect of endothelial progenitor cells (EPCs) which complexed with neuron stem cells (NSCs) after transplanted into ischemia and reperfusion (I/R) rat model on the proliferation and apoptosis of the NSCs and vasal construction. Methods Totally 150 SD adult male rats were randomly and equally divided into 5 groups, sham-operation group, I/R group, I/R+NSCs group, I/R+EPCs group, and I/R+NSCs+EPCs group. The rats were further divided into 5 subgroups according to the time points of 3, 7, 14, 30 and 60 d after transplantation. I/R rat model was established by reversiblyligating middle cerebral artery occlusion. NSCs were derived from the hippocampus of SD rats born in 24 h and identified with Nestin staining. EPCs were obtained from the artery blood of SD rats and verified with immunocytochemical stainings of CD31, CD34 and KDR after culture. The complex of NSCs and EPCs was produced with aid of laminin. Then the complex were transplanted into the ischemia penumbra of corresponding model rat brain. The proliferation and apoptosis of NSCs, and the fomation of new vessels were observed through immunohistochemistry and double-labeled immunofluorescence staining. Results The proliferation of NSCs was increased, apoptosis cells were decreased and the new vessels were raised in the complex transplantation when compared with single NSCs or EPCs transplantation groups. Conclusion The complex of NSCs and EPCs transplantation improves the proliferation of NSCs, suppresses cell apoptosis and promotes the formation of new vessels.
8.Complex of neural stem cells and endothelial progenitor cells enhances differentiation of neural stem cells to neuron and formation of synapse after implanted in MCAO rats
Zhiguo QI ; Xiaofeng ZHU ; Qizhi FU ; Peng XIE
Journal of Third Military Medical University 2003;0(07):-
Objective To explore the effect of the complex containing neuron stem cells(NSCs)and endothelial progenitor cells(EPCs)after being transplanted to ischemia and reperfusion rat model on the differentiation of neural stem cells to neuron and synapse formation.MethodsTotally 300 SD adult male rats were randomly divided into sham operation group,middle cerebral artery occlusion(MACO)model group,MACO+NSCs group,MACO+EPCs group,and MACO+complex group,and every group were further divided into 6 subgroups according to time points 1,3,7,14,30 and 60 d after operation,NSCs were isolated from the hippocampus of neonatal SD rats born in 24 h and identified with Nestin staining.EPCs were obtained from the artery blood of SD rats and verified with immunocytochemical stainings of CD31 and CD34 after culture.NSCs and EPCs were cultured together to produce the complex with aid of laminin.Then normal saline,the NSCs,EPCs,or complex(2?1010/L)were transplanted into the ischemia penumbra of corresponding model rat brain,sham control or MACO rats.The differentiation of NSCs,the expression of P38,synapsin-I,mRNA of connexin 43 were observed with double label immunofluorescence technique,immunohistochemical method,RT-PCR and Western blot analysis in ischemic penumbra.ResultsCompared with other groups,there were more double Brdu and neural special enolase positive cells in MACO+complex group with the increased expression of P38.RT-PCR and Western blot analysis indicated that MACO+complex group had significantly higher expressions of synapsin-I at mRNA and protein levels in ischemic penumbra,and so did the mRNA expression of connexin 43.ConclusionThe transplantation of the complex of NSCs and EPCs improves the NSCs differentiation to neuron,synapse formation and reconstruction of neural network.
9.Different exogenous interventions in angiogenesis to repair neurological deficits in cerebral ischemia rats
Zhiguo QI ; Hongmei LIANG ; Xiaofeng ZHU ; Peng XIE
Journal of Third Military Medical University 2003;0(08):-
Objective To explore the relationship between angiogenesis and ischemic neurological deficit repair through exogenous interventions,and investigate optimal intervention routes for angiogenesis in cerebral ischemia rats.Methods Totally 240 SD rats were randomly divided into sham operation group,ischemic control group,ischemia and vascular endothelial growth factor(VEGF) group [1 653.3 ng/(g?d),i.p.,for 10 d],ischemia and endothelial progenitor cell transplantation(EPCs) group(2?1010/L,10 ?l),ischemia and anti-VEGF monoclonal antibody group [3 mg/(kg?d),i.p.,for 10 d].Cerebral microvessel density,somatosensory evoked potentials(SEP) and motor evoked potentials(MEP) and behavior were observed in 1,3,7,14,30 and 60 d after injury.Results New blood vessel density of ischemia and VEGF group,ischemia and EPCs group were significantly higher than ischemic control group in all time points besides 1 d after injury(P
10.Discussion on Assay of Geniposide in Fructus Gardeniae in Chinese Pharmacopoeia(2005 Edition)Volume I
Peng LEI ; Shao LIU ; Xinzhong LI ; Zhiguo TAN ; Jing LI
Traditional Chinese Drug Research & Clinical Pharmacology 1993;0(03):-
Objective To improve the method for determination of geniposide in Fructus Gardeniae.Methods The improved method was compared with the pharmacopoeia method.The content of geniposide was determined by HPLC at 238nm detection wavelength with acetonitrile-water(15:85)as mobile phase .Results The improved method in which 50 % methanol was used as solvent was superior to the pharmacopoeia method in which methanol was adopted as solvent.A higher geniposide content was abtained from the former.Conclusion The improved method is convenient and accurate,and can be used to supply reference evidence for the assay of Fructus Gardeniae in the new edition of pharmacopoeia.