The surface acoustic wave （SAW） propagating in a sample of steel is simulated by using finite element method （FEM）. The waves are excited by a load function with propagation properties such as phase velocity dispe...The surface acoustic wave （SAW） propagating in a sample of steel is simulated by using finite element method （FEM）. The waves are excited by a load function with propagation properties such as phase velocity disper- sion and wide bandwidth. A two-dimensional model consisting of surface defects loaded with a wideband 50--200 M Hz and short time 0.1 gs displacement function is investigated in the time and frequency domains. By transient dy- namic analysis, Fourier transform and dispersion calculation, snapshots of propagating wave and responses from sens- ing points are presented. It is indicated that this supervision approach is sensitive to the surface cracks and reflections.展开更多
Objectives: To explore the relationship betweenquantitative Treponema pallidum DNA (TP-DNA) PCR testingand the Toludine Red Unheated Serum Test (TRUST) inpatients with syphilis before and after treatment, and evaluate...Objectives: To explore the relationship betweenquantitative Treponema pallidum DNA (TP-DNA) PCR testingand the Toludine Red Unheated Serum Test (TRUST) inpatients with syphilis before and after treatment, and evaluatethe clinical value of quantitative TP-DNA testing in thediagnosis and treatment evaluation of syphilis. Methods: 29 patients with primary (12 cases) or secondary(17 cases) syphilis, who met the criteria set for this study wererecruited as subjects. All patients were treated with 2.4 millionunits benzathine penicillin IM weekly for 3 weeks.Quantitative tests of TP-DNA in the patients' plasma wereperformed using FQ-PCR before and after the treatment.Serologic tests including TRUST and TPPA were alsoperformed. Results: Before the treatment, 9 out of 12 primary syphilispatients (75%) and all secondary syphilis patients (17/17)tested positive for Treponema pallidum (TP) by TP-DNAtesting. The average quantitative test values of TP-DNA inprimary and secondary syphilis patients were (3.38±2.34)×10~4and (5.73±1.33)×10~6 copies/ml, respectively. After threemonths of treatment, 1 of the 9 primary and 5 out of 17secondary syphilis patients were positive upon TP-DNAtesting, respectively. The average quantities of TP-DNA were2.01×10~2 copies/ml in primary and 5.87×10~2 copies/ml insecondary syphilis patients with positive TRUST and TP-DNAtests, and 3.09×10~2 copies/ml for those with negative TRUSTrespectively. After nine months of treatment, all the primaryand secondary syphilis patients were negative upon TP-DNAtesting, while all primary and 14 of 17 (82.35%) secondarysyphilis patients showed negative TRUST results. Conclusion: That the results of TP-DNA tests are notconsistent with those or TRUST before and after treatmentindicates that quantitative TP-DNA testing may have valuableclinical significance in the early diagnosis and evaluation oftreatment regimens for syphilis.展开更多
Objectives: To characterize the distribution pattern of biovars and scrotypes or Ureaplasma urealyyicum in normalhealthy women, sexually transmitted infections clinic clients,and in sex workers. Methods: We cultured c...Objectives: To characterize the distribution pattern of biovars and scrotypes or Ureaplasma urealyyicum in normalhealthy women, sexually transmitted infections clinic clients,and in sex workers. Methods: We cultured cervical swabs taken from 261physical check-up clients, 599 STI clinic outpatients and 98 sexworkers using commercial selective medium. Some positivecultures were further biotyped and serotyped by PCR. Results: (1) U. urealyticum is more commonly isolated in sexworkers (90.8%) than in the physical check-up group (60.9%)or the STI outpatient group (61.3%) (P<0.001). (2) Biovar 1of U. 'realyticum (95.0%), especially single infection ofserotype 1. 3, and 6 of biovar 1, is commonly found in healthywomen. (3) Biovar 2 infection of U urealyticum is moreprevalent in sex workers (28.1%) and STI outpatients group(26.6%) than that in the physical check-up group (4.9%) (P<0.001). (4) Mixed infection caused by more than one serotypeof U urealyticum increased from physical check-up group(8.6%) to STI utpatients (12.4%) to sex workers (23.9%) (P<0.01). (5) There is no statistically significant difference in thedistribution of serotype 1, 3, and 6 of biovar 1 among thesethree groups (P=0.763). (6) The PCR method described here isrelatively simple, rapid and specific for the biotyping andserotyping of biovar 1 of U urealyticum. Conclusion: We should pay more attention to biovar 2 andmixed infections of U. urealyticum than single infection ofhiovar 1 in clinic practice. PCR is a good method for biotypingand serotvping.展开更多
Objectives: To evaluate the Vidas Chlamydia (CHL) assayfor detecting C.Trachomatis with swabs and first catch urine(FCU) specimens from STD patients and high riskpopulations. Methods: A total of 383 pahents were teste...Objectives: To evaluate the Vidas Chlamydia (CHL) assayfor detecting C.Trachomatis with swabs and first catch urine(FCU) specimens from STD patients and high riskpopulations. Methods: A total of 383 pahents were tested with tissueculture (TC), Vidas CHL and polymerase chain reaction (PCR)for C.trachomatis on male and female swabs, with Vidas CHLtesting male FCU specimens. CHL positive and equivocalresults were confirmed with a blocking assay (CHB). Truepositive were defined as either TC positive, or TC negtive butCHL and PCR positive. The performance of TC, CHL andPCR were evaluated according to this expanded goldstandard. Results: Compared with the expanded gold standard, 54 ofthe 232 male specimens were true positive results. For maleswabs, TC, CHL and PCR had sensitivities of 90.7%, 96.3%and 94.4%, and specificities of 100%, 98.3% and 97.2%,respectively. Differences were not statistically significant. Formale FCU specimens, CHL sensitivity and specificity were83.3% and 98.3%; there was little difference between theseresults and that of matched swabs. Compared with theexpanded gold standard, 28 of the 151 female swabs were truepositive; TC, CHL and PCR had sensitivities of 82.1%, 100%and 96.4%, and specificities of 100%, 98.4% and 97.6%,respectively. The difference was also not significant. Conclusions: Vidas CHL assay is very scnsitive and specificfor C.trachomatis detection with swab specimens of male andfemale STD patients. For male FCU specimens, the assay alsohad high sensitivity and specificity. CHB may not be needed inthe routine detection or Chlamydia infections. Populationswith higher incidence of C.trachomatis infection.展开更多
A deterministic model for evaluating the impact of voluntary testing and treatment on the transmission dynamics of tuberculosis is formulated and analyzed. The epidemio- logical threshold, known as the reproduction nu...A deterministic model for evaluating the impact of voluntary testing and treatment on the transmission dynamics of tuberculosis is formulated and analyzed. The epidemio- logical threshold, known as the reproduction number is derived and qualitatively used to investigate the existence and stability of the associated equilibrium of the model system. The disease-free equilibrium is shown to be locally-asymptotically stable when the reproductive number is less than unity, and unstable if this threshold parameter exceeds unity. It is shown, using the Centre Manifold theory, that the model undergoes the phenomenon of backward bifurcation where the stable disease-free equilibrium co- exists with a stable endemic equilibrium when the associated reproduction number is less than unity. The analysis of the reproduction number suggests that voluntary tuber- culosis testing and treatment may lead to effective control of tuberculosis. Furthermore, numerical simulations support the fact that an increase voluntary tuberculosis testing and treatment have a positive impact in controlling the spread of tuberculosis in the community.展开更多
基金Supported by National Natural Science Foundation of China (No. 51075296)Sate Key Laboratory of Precision Measuring Technology and Instruments Project (No. PILT1106)
文摘The surface acoustic wave （SAW） propagating in a sample of steel is simulated by using finite element method （FEM）. The waves are excited by a load function with propagation properties such as phase velocity disper- sion and wide bandwidth. A two-dimensional model consisting of surface defects loaded with a wideband 50--200 M Hz and short time 0.1 gs displacement function is investigated in the time and frequency domains. By transient dy- namic analysis, Fourier transform and dispersion calculation, snapshots of propagating wave and responses from sens- ing points are presented. It is indicated that this supervision approach is sensitive to the surface cracks and reflections.
文摘Objectives: To explore the relationship betweenquantitative Treponema pallidum DNA (TP-DNA) PCR testingand the Toludine Red Unheated Serum Test (TRUST) inpatients with syphilis before and after treatment, and evaluatethe clinical value of quantitative TP-DNA testing in thediagnosis and treatment evaluation of syphilis. Methods: 29 patients with primary (12 cases) or secondary(17 cases) syphilis, who met the criteria set for this study wererecruited as subjects. All patients were treated with 2.4 millionunits benzathine penicillin IM weekly for 3 weeks.Quantitative tests of TP-DNA in the patients' plasma wereperformed using FQ-PCR before and after the treatment.Serologic tests including TRUST and TPPA were alsoperformed. Results: Before the treatment, 9 out of 12 primary syphilispatients (75%) and all secondary syphilis patients (17/17)tested positive for Treponema pallidum (TP) by TP-DNAtesting. The average quantitative test values of TP-DNA inprimary and secondary syphilis patients were (3.38±2.34)×10~4and (5.73±1.33)×10~6 copies/ml, respectively. After threemonths of treatment, 1 of the 9 primary and 5 out of 17secondary syphilis patients were positive upon TP-DNAtesting, respectively. The average quantities of TP-DNA were2.01×10~2 copies/ml in primary and 5.87×10~2 copies/ml insecondary syphilis patients with positive TRUST and TP-DNAtests, and 3.09×10~2 copies/ml for those with negative TRUSTrespectively. After nine months of treatment, all the primaryand secondary syphilis patients were negative upon TP-DNAtesting, while all primary and 14 of 17 (82.35%) secondarysyphilis patients showed negative TRUST results. Conclusion: That the results of TP-DNA tests are notconsistent with those or TRUST before and after treatmentindicates that quantitative TP-DNA testing may have valuableclinical significance in the early diagnosis and evaluation oftreatment regimens for syphilis.
文摘Objectives: To characterize the distribution pattern of biovars and scrotypes or Ureaplasma urealyyicum in normalhealthy women, sexually transmitted infections clinic clients,and in sex workers. Methods: We cultured cervical swabs taken from 261physical check-up clients, 599 STI clinic outpatients and 98 sexworkers using commercial selective medium. Some positivecultures were further biotyped and serotyped by PCR. Results: (1) U. urealyticum is more commonly isolated in sexworkers (90.8%) than in the physical check-up group (60.9%)or the STI outpatient group (61.3%) (P<0.001). (2) Biovar 1of U. 'realyticum (95.0%), especially single infection ofserotype 1. 3, and 6 of biovar 1, is commonly found in healthywomen. (3) Biovar 2 infection of U urealyticum is moreprevalent in sex workers (28.1%) and STI outpatients group(26.6%) than that in the physical check-up group (4.9%) (P<0.001). (4) Mixed infection caused by more than one serotypeof U urealyticum increased from physical check-up group(8.6%) to STI utpatients (12.4%) to sex workers (23.9%) (P<0.01). (5) There is no statistically significant difference in thedistribution of serotype 1, 3, and 6 of biovar 1 among thesethree groups (P=0.763). (6) The PCR method described here isrelatively simple, rapid and specific for the biotyping andserotyping of biovar 1 of U urealyticum. Conclusion: We should pay more attention to biovar 2 andmixed infections of U. urealyticum than single infection ofhiovar 1 in clinic practice. PCR is a good method for biotypingand serotvping.
文摘Objectives: To evaluate the Vidas Chlamydia (CHL) assayfor detecting C.Trachomatis with swabs and first catch urine(FCU) specimens from STD patients and high riskpopulations. Methods: A total of 383 pahents were tested with tissueculture (TC), Vidas CHL and polymerase chain reaction (PCR)for C.trachomatis on male and female swabs, with Vidas CHLtesting male FCU specimens. CHL positive and equivocalresults were confirmed with a blocking assay (CHB). Truepositive were defined as either TC positive, or TC negtive butCHL and PCR positive. The performance of TC, CHL andPCR were evaluated according to this expanded goldstandard. Results: Compared with the expanded gold standard, 54 ofthe 232 male specimens were true positive results. For maleswabs, TC, CHL and PCR had sensitivities of 90.7%, 96.3%and 94.4%, and specificities of 100%, 98.3% and 97.2%,respectively. Differences were not statistically significant. Formale FCU specimens, CHL sensitivity and specificity were83.3% and 98.3%; there was little difference between theseresults and that of matched swabs. Compared with theexpanded gold standard, 28 of the 151 female swabs were truepositive; TC, CHL and PCR had sensitivities of 82.1%, 100%and 96.4%, and specificities of 100%, 98.4% and 97.6%,respectively. The difference was also not significant. Conclusions: Vidas CHL assay is very scnsitive and specificfor C.trachomatis detection with swab specimens of male andfemale STD patients. For male FCU specimens, the assay alsohad high sensitivity and specificity. CHB may not be needed inthe routine detection or Chlamydia infections. Populationswith higher incidence of C.trachomatis infection.
文摘A deterministic model for evaluating the impact of voluntary testing and treatment on the transmission dynamics of tuberculosis is formulated and analyzed. The epidemio- logical threshold, known as the reproduction number is derived and qualitatively used to investigate the existence and stability of the associated equilibrium of the model system. The disease-free equilibrium is shown to be locally-asymptotically stable when the reproductive number is less than unity, and unstable if this threshold parameter exceeds unity. It is shown, using the Centre Manifold theory, that the model undergoes the phenomenon of backward bifurcation where the stable disease-free equilibrium co- exists with a stable endemic equilibrium when the associated reproduction number is less than unity. The analysis of the reproduction number suggests that voluntary tuber- culosis testing and treatment may lead to effective control of tuberculosis. Furthermore, numerical simulations support the fact that an increase voluntary tuberculosis testing and treatment have a positive impact in controlling the spread of tuberculosis in the community.
