1.Dynamic analysis of the periodontal ligament
Yanhuan PAN ; Da MA ; Fan WANG
Journal of Practical Stomatology 2000;0(06):-
Objective:To investigate the influences of material properties and damping effect on the dynamic response analysis of human periodontal ligament. Methods: A 3-D finite element model of human teeth and periodontal tissue was built from graphic information obtained by CT scanning. Dynamic analysis was performed to investigate the influence of different damping effects on the stresses of periodontal ligament by the finite element method. Results: (a) No significant difference of stress between small and large deformation assumption was found, the variation was no more than 1.4%.(b) Dynamic response was obtained under ? varies from 0 to 1.2. After one mastication period, the residual stress at interior surface was larger than that at exterior surface, with a maximum value of ? r = 0.34 MPa at labial cervical area. Conclusion: Appropriate assumptions on material properties may reduce the cost of analysis. After one mastication period, some levels of residual stresses are in periodontal ligament and influenced by material damp.
2."Lessons and illuminations of Tianjin port ""8 · 12"" explosion hazard"
Mengmeng CUI ; Da FAN ; Jinjun ZHANG
Chinese Journal of Emergency Medicine 2015;24(10):1078-1081
Objective To explore how to improve the capability of emergency rescue to cope with the explosion of hazardous chemicals through analyzing the rescue process of Tianjin port 8 · 12 explosion hazard.Methods The process of explosion emergency rescue on the hazardous chemicals warehouse of Ruihai company in Tianjin Port on the evening of August 12,2015,were analyzed,summarize the experience and lessons.Results There were some shortcomings on field assessment,safety zoning,EMSS,treatment in hospital,personal protection equipment and public knowledge on hazardous chemicals explosion in Tianjin port 8.12 explosion hazard.we should learn from the lessons,to provide reference for the future similar rescue.Conclusions The ability of emergency rescue team to deal with the major hazardous chemicals explosion should further improve,to protect the safety of society and health of common people.
3.Troubleshooting of bioinequivalence of compound valsartan tablets.
Da SHAO ; Yi-Fan ZHANG ; Yan ZHAN ; Xiao-Yan CHEN ; Da-Fang ZHONG
Acta Pharmaceutica Sinica 2014;49(4):524-529
The study aims to evaluate the bioequivalence of valsartan hydrochlorothiazide tablets, and to investigate the potential cause of bioinequivalence. This was a single-center study with an open, randomized double-way crossover design. Test and reference preparations containing 160 mg of valsartan and 25 mg of hydrochlorothiazide were given to 36 healthy male volunteers. Plasma concentrations of valsartan and hydrochlorothiazide were determined simultaneously by LC-MS/MS. The pharmacokinetic parameters and relative bioavailability were calculated, while the bioequivalence between test and reference preparations were evaluated. The dissolution profiles of test and reference preparations in four different mediums were determined via dissolution test and HPLC. The similarity was investigated according to the similarity factors (f2). The F(o-t) and F(0-infinity) were (139.4 +/- 65.2)% and (137.5 +/- 61.2)% for valsartan of test preparations. It led to get the conclusion that test and reference preparations were not bioequivalent for valsartan. A significant difference was observed between test and reference tablets in the valsartan dissolution test of pH 1.2 hydrochloric acid solution. The key factor of the bioinequivalence might be that dissolution of valsartan in acid medium has marked difference between two preparations.
Administration, Oral
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Adolescent
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Adult
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Angiotensin II Type 1 Receptor Blockers
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administration & dosage
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adverse effects
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blood
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pharmacokinetics
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Antihypertensive Agents
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administration & dosage
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adverse effects
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blood
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pharmacokinetics
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Area Under Curve
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Chromatography, Liquid
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Cross-Over Studies
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Drug Liberation
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Humans
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Hydrochlorothiazide
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administration & dosage
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adverse effects
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blood
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pharmacokinetics
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Male
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Tablets
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Tandem Mass Spectrometry
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Therapeutic Equivalency
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Valsartan
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administration & dosage
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adverse effects
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blood
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pharmacokinetics
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Young Adult
4.Surgical therapy and rehabilitation training for children with hyper-reflexic neuropathic urinary incontinence
Yingzhong FAN ; Da ZHANG ; Jiaxiang WANG ; Bianyun WANG ; Qian ZHANG
Chinese Journal of Tissue Engineering Research 2005;9(19):246-247
BACKGROUND: Myelodysplasia induced by spina bifida is one of the common developmental malformations of the nervous system in children, and neurogenic urinary incontinence induced by it can affect the children' s quality of life.OBJECTIVE: To observe the effects of surgical therapy and rehabilitation training for children with hyper-reflexic neuropathic urinary incontinence.DESIGN: A controlled follow-up observation.SETTING: Department of Pediatric Surgery, First Hospital Affiliated to Zhengzhou University.PARTICIPANTS: A total of 81 children(54 males and 27 females), aged 4 to 14 years treated for hyper-reflexic neuropathic urinary incontinence between January 1992 and October 2000 were selected. All the cases were confirmed loose pelvic floor muscle and smaller bladder capaeity before operation. Moreover, all cases with neuropathic urinary incontinence were proved to be hyper-reflexic neurogenic bladder by urodynamic examination.METHODS: Pelvic muscles of the 81 patients were strengthened with bilateral iliopsoas and the bladder was augmented on the basis of ileocystoplasty. Five patients had an additional bladder neck suspension. Wound healing was satisfactory after 3 weeks; therefore, rehabilitative exercise for coordination was performed. The improvements in symptoms and urodynamic results were followed up.RESULTS: Urinary catheters were removed in the 81 patients 2 weeks after operation. Forty patients had voiding desire before micturition, with linear urine current, more than 60 minutes' interval between micturitions, and almost normal or normal maximal bladder capacity and pressure and residual urine volume, which was regarded as significantly improved. Twenty-three patients had voiding desire before micturition, with linear urine current, more than 40 minutes' interval between micturitions, and reduced maximal bladder capacity and residual urine volume, but increased bladder pressure, which was regarded as improved. However, 18 patients were improved after regular bladder training. The postoperative urodynamic results in 9 patients showed that the average bladder pressure, average urethra pressure, residual urine volume and maximal bladder capacity were 1.2 kPa, 1.15 kPa, 30 - 50 mL and 300 -600 mL, respectively. Of the 81 cases, 63 cases were followed up completely for 6 months whereas the others had no complete follow-up data. The follow-up results showed significant outcomes in 56 cases, improvement in 5 and no effect in 2, with the total effective rate of 97%.CONCLUSION: Satisfactory results can be obtained by combined augmentative ileocystoplasty with strengthening of pelvic floor by iliopsoas for children with hyer-reflexic neuropathic urinary incontinence. The combination of micturition reflex and control training after operation produces obvious therapeutic effects.
5.Follow-up study of cystectasy using a demucosalized ileoseromuscular layer patch containing neurovascular pedicle for overactive neurogenic urinary incontinence
Jiaxiang WANG ; Da ZHANG ; Yingzhong FAN ; Qian ZHANG
Chinese Journal of Tissue Engineering Research 2005;9(14):190-192
BACKGROUND: There are various surgical treatments to neurogenic urinary incontinence, and the curative effects differ a lot. The present research was to study the effect of surgical treatment of neurogenic urinary incontinence.OBJECTIVE: To evaluate the therapeutic effect of cystectasy using a demucosalized ileoseromuscular layer patch containing neurovascular pedicle for the patients with overactive neurogenic urinary incontinence to suggest for improvement in operations.DESIGN: A retrospective case analysis based on the study of the patients.SETTING: Department of pediatric surgery of a university hospital.PARTICIPANTS: A follow-up study was conducted to 68 patients who were treated at the Department of Pediatric Surgery of the First Affiliated Hospital of Zhengzhou University from April 1998 to January 2004 for neurogenic urinary incontinence. There were 38 cases with full follow-up data.METHODS: All the 38 patients with overactive neurogenic urinary incotinence underwent bladder augmentation using a demucosalized ileoseromuscalar layer patch containing neurovascular pedicle and were followed up for 4to 69 months, and 17.2 months in average. Among the patients, 34 with pelvic diaphragm ptosis were treated with pelvic diaphragm strengthening at the same time.MAIN OUTCOME MEASURES: The preoperative and postoperative symptoms, bladder compliance and maximum bladder capacity and the relative safe bladder capacity were studied.RESULTS: Thirty of 38 patients showed improvement in the symptoms of urinary incontinence(micturition interval > 1 hour) after the operation. The results of urodynamics showed that the all patients with bladder augmentation using a demucosalized ileoseromuscular layer patch containing neurovascular pedicle urinated under abdominal pressure, and no active contraction of detrusor urinae was detected. The compliance, the maximum bladder capacity and the relative safe bladder capacity were increased by(27.43 ± 24.78) mL/kPa (P <0.01), (122. 18±79.99) mL(P <0.01) and(98.63 ±86.78) mL ( P < 0.01 ) respectively. No aggravation of upper urinary function injury was observed after the operation.CONCLUSION: The bladder augmentation using a demucosalized ileoseromuscular layer patch ontaining neurovascular pedicle can protect the upper urinary function, and it is an effective approach to treating overactive neurogenic urinary incontinence.
7.A clinical analysis of male patients with systemic lupus erythematosus
Zhanyun DA ; Jie QIAN ; Yaping FAN ; Tongsun QIAN
Chinese Journal of Rheumatology 2008;12(8):527-529
Objective To analyze the clinical characteristics of male patients with systemic lupus ery thematosus in a cohort of Chinese patients.Methods 325 lupus nephritis patients (38 male and 287 female patients) admitted to our hospital from January 1997 to December 2006 were summarized in this cohort.The difference in manifestations and laboratory features were analyzed between male and female lupus nephritis patients.Results ① Male lupus nephritis patients had more frequent episodes of serositis (P<0.05),while fe male lupus nephritis patients more frequently had arthralgia,malar rash,oral ulcers and neuropsychiatric lu pus.② The kidney was involved with early stage of the disease in male patients.The rate of misdiagnosis was higher in male lupus nephritis patients than that of the female patients.③ The prevalence of ANA positivity and thrombocytopenia was higher in male patients than that of the female patients.The prevanee of positive anti-ENA antibody,anti-Sin antibody,anemia and hypergammaglobulinemia was lower in male patients than those of female patients.No difference was found in the presence of positive anti-RNP antibody,hypocom plementemia,elevated erythrocyte sedimentation rate and leucoeytopenia between the two groups.Conclusion The clinical pictures of male systemic lupus erythematosus patients are atypical except for kidney involvement.The kidney involvement of male lupus patients is characterized by the early onset,rapid progression and high rate of misdiagnosis.Physicians should familiar with these differences.Early diagnosis and appropriate treat ment are essential for controlling disease progress.
8.Effects of the different sections of receptor-associated protein on the expression and distribution of TRPC6,synaptopodin and podocalyxin in passive Heymann nephritis
Haixia CAO ; Dayong LI ; Yaping FAN ; Zhanyun DA ; Feng WANG ; Xiaolan CHEN ; Yajun WU ; Lan SHI
Chinese Journal of Nephrology 2011;27(6):423-427
objective To investigate the effects of different sections of receptor associated protein (RAP) on the expression and distribution of TRPC6,synaptopodin and podocalyxin in passive Heymann nephritis(PHN). Methods Male Sprague-Dawley rats were injected with three kinds of antisera (anti-RAP full-length serum,anti-RAP N-terminal serum and anti-RAP C-terminal serum)to establish three kinds of PHN models.The control group was injected with normal rabbit serum.The quatitation of 24 h urinary protein,serum albumin and creatinine were taken before injection and one week after PHN model successfully induced.The histopathologic changes of renal tissues were observed by light microscopy.The expression and distribution of TRPC6,synaptopodin and podocalyxin in glomerular podocytes were observed by laser scanning confocal microscopy and analyzed by fluorescence quantitative software after indirect immunofluorescence double staining.Results The quantities of 24 h urinary protein in the three model groups were significantly higher than those of themselves before injection and control groups (P<0.01,respectively).The values of serum albumin and creatinine were not significantly different before and after injection (P>0.05).The expression of TRPC6 in podocytes was higher in the PHN model groups than that of control group.Fluorescence intensity of TRPC6 in RAP full-length group was stronger than that in RAP N-terminal or C-terminal groups.The expressions of synaptopodin and podocalyxin distributed along the glomerular basement membrane as spot,discontinuous short line and defect of some segments,and were lower in three PHN groups than those of control group.Fluorescence intensity of synaptopodin and podocalyxin among three PHN groups had no differences. Conclusions RAP full-length and N-terminal or C-terminal parts can increase the expression of podocyte TRPC6,but decrease the expressions of synaptopodin and podocalyxin,and alter their distribution,which may be associated with the proteinuria,however,their role in the PHN pathogenesis needs further study.
9.Effects of smoking and alcohol drinking on arsenic metabolism of people exposed to different concentrations of arsenic in drinking water
Bo-ying, LIU ; Da, WANG ; Qiang, ZHANG ; Quan-mei, ZHENG ; Gui-fan, SUN
Chinese Journal of Endemiology 2012;31(1):28-31
Objective To explore the effects of smoking and alcohol drinking on arsenic metabolism of people exposed to different concentrations of arsenic in drinking water.Methods Residents in Shanxi exposed to different concentrations of arsenic in drinking water and age ≥ 18 years old adults were chosen as the subjects for this study in 2008,the subjects were divided into three groups according to the concentrations of arsenic in drinking water: high-arsenic exposure group (more than 0.05 mg/L),low-arsenic exposure group (between 0.01 and 0.05 mg/L) and control group(less than 0.01 mg/L),excluded recently had eaten seafood and had poisoning symptoms of chronic arsenic in drinking water in the crowd.Smoking and alcohol drinking habits were investigated by questionnaire.Arsenic species in the urine samples were detected with hydride generation atomic absorption spectroscopy.Total arsenic(tAs) was the sum of iAs%,MMA% and DMA%.iAs%,MMA% and DMA% were calculated as iAs/tAs,MMA/tAs and DMA/tAs,respectively.The first methylation ratio(FMR) and the secondary methylation ratio(SMR) were calculated as (MMA + DMA)/tAs and DMA/(MMA + DMA),respectively.Results Three hundred and ninety-five adults were chosen in this study.In the high exposure group the alcohol drinking and smoking subjects had higher MMA%(16.24%) but lower SMR(82.19% ) than the non-drinking and non-smoking subjects (12.16% and 86.13%,respectively).The differences of both MMA% and SMR were significant(P < 0.05 ).No significant difference was observed between the non-smoking/non-drinking subjects and the smoking or the drinking subjects(all P > 0.05 ).In the low exposure group there were higher MMA%( 13.86%,13.99%) lower DMA%(72.87%,77.76%)and lower SMR (83.48%,83.90% ) in those with smoking or drinking/smoking compared with the non-drinking and non-smoking subjects (11.83%,80.35% and 86.54%,respectively,all P <0.05 ).No significant difference was observed between drinkers and non-drinking/non-smoking subjects(P > 0.05).In the control group there were a higher MMA%( 17.27%,17.06%) lower DMA% (73.89%,72.29%) and lower SMR (81.48%,82.58% ) in those with smoking or drinking/smoking compared with the non-drinking and nonsmoking subjects( 11.52%,79.68% and 87.19%,respectively,all P < 0.05).No significant difference was observed between drinkers and the non-drinking/non-smoking subjects (all P > 0.05).ConclusionThe arsenic methylation capacity of people with drinking and smoking is poorer than that of non-drinking and non-smoking subjects after arsenic exposure.
10.MRS application in temporal lobe epilepsy without hippocampal sclerosis
Zijian FAN ; Yongbo ZHANG ; Wenping JU ; Jie LIANG ; Da LI ; Xianliang WANG
Chinese Journal of Medical Imaging Technology 2017;33(9):1326-1330
Objective To investigate the application value of MRS in temporal lobe epilepsy (TLE) without hippocampal sclerosis.Methods A retrospective study was conducted in 23 unilateral TLE patients (TLE group) with absence of hippocampal sclerosis and 20 age-matched normal control subjects (control group).All of them underwent conventional MRI and MRS.N-acetyl aspartate (NAA)/creatine (Cr),choline (Cho)/Cr ratios of bilateral hippocampus in 2 groups were analyzed.Eleven of 23 patients underwent surgical treatment,pathological findings and surgical outcomes were evaluated.Results The NAA/Cr ratios of ipsilateral hippocampus significantly decreased compared with that in the contralateral hippocampus (t=-7.97,P<0.001) and the control group (t=-9.96,P<0.001).There was no significant difference between the contralateral hippocampus in patients and the control group (t=-1.21,P=0.12).The Cho/Cr ratios of ipsilateral hippocampus in TLE had no significant difference compared with contralateral hippocampus (t=0.50,P=0.31) and the control group (t=-0.59,P=0.28).The pathological findings of the 11 patients who underwent temporal lobe resection indicated small amounts of neuronal loss and unobvious gliosis.Conclusion MRS is helpful in clinical practice to lateralize and localize the epileptogenic foci in the absence of hippocampal sclerosis in patients with TLE.