Vertical drains are used to accelerate consolidation of clays in ground improvement projects.Smear zones exist around these drains,where permeability is reduced due to soil disturbance caused by the installation proce...Vertical drains are used to accelerate consolidation of clays in ground improvement projects.Smear zones exist around these drains,where permeability is reduced due to soil disturbance caused by the installation process.Hansbo solution is widely used in practice to consider the effects of drain discharge capacity and smear on the consolidation process.In this study,a computationally efficient diameter reduction method(DRM)obtained from the Hansbo solution is proposed to consider the smear effect without the need to model the smear zone physically.Validated by analytical and numerical results,a diameter reduction factor is analytically derived to reduce the diameter of the drain,while achieving similar solutions of pore pressure dissipation profile as the classical full model of the smear zone and drain.With the DRM,the excess pore pressure u obtained from the reduced drain in the original un-disturbed soil zone is accurate enough for practical applications in numerical models.Such performance of DRM is independent of soil material property.Results also show equally accurate performance of DRM under conditions of multi-layered soils and coupled radial-vertical groundwater flow.展开更多
Pneumcystis jirovecii is a pathogen that causes Pneumocystis pneumonia (PCP), an infection in (HIV/ADS) and other immunocompromised patients. The rare reports of P. jirovecii pneumonia in sub-Saharan Africa are contro...Pneumcystis jirovecii is a pathogen that causes Pneumocystis pneumonia (PCP), an infection in (HIV/ADS) and other immunocompromised patients. The rare reports of P. jirovecii pneumonia in sub-Saharan Africa are controversial due to the high HIV/AIDS seropositivity. The study determined the significance of P. jirovecii in TB smear negative retreatment patients at the Coast General Teaching Referral Hospital-Mombasa. Sputum samples were subjected to toluidine blue O(TBO) stain for microscopy and polymerase chain reaction (PCR). A total of 100 TB smear negative participants were enrolled in the study and expectorated sputum was collected. Out of the 100 patients, 63 men and 37 women. Patients aged 31 to 53 made up 62% of the patients. The patients aged 31 to 53 made up 75% of the patients (Min = 11y, Max = 85y). The median age of the patients was 42 years. Nested PCR has a prevalence of 41% (41 instances). TBO staining has a prevalence of 29% (29 instances). Detecting an additional 13 more patients than toluidine O staining technique. The sensitivity of toluidine blue O staining was 33.82%, which indicates that it correctly identified 33.82% of true positive cases compared to PCR. The specificity of toluidine blue O staining was 97.82%, indicating that it had a high ability to correctly identify true negative cases compared to PCR, suggesting that it was good at ruling out non-P. jirovecii cases. The study confirms that P. jirovecii is as a significant cause of persistent symptoms in TB patients that could be responsible for persistent symptoms despite TB treatment. We recommend fungal diagnostics in such patients before retreatment.展开更多
Blood smear test is the basic method of blood cytology and is also a standard medical test that can help diagnose various conditions and diseases.Morphological examination is the gold stan-dard to determine pathologic...Blood smear test is the basic method of blood cytology and is also a standard medical test that can help diagnose various conditions and diseases.Morphological examination is the gold stan-dard to determine pathological changes in blood cell morphology.In the biology and medicine automation trend,blood smears'automated management and analysis is very necessary.An online blood smear automatic microscopic image detection system has been constructed.It includes an online blood smear automatic producing part and a blood smear automatic micro-scopic image detection part.Online identity authentication is at the core of the system.The identifiers printed online always present dot matrix digit code(DMDC)whose stroke is not continuous.Considering the particularities of DMDC and the complexities of online application environment,an online identity authentication method for blood smear with heterological theory is proposed.By synthesizing the certain regional features according to the heterological theory,high identification accuracy and high speed have been guaranteed with few features required.In the experiment,the suficient correct matches bet ween the tube barcode and the identification result verified its feasibility and validity.展开更多
To further extend study on celestial attitude determination with strapdown star sensor from static into dynamic field, one prerequisite is to generate precise dynamic simulating star maps. First a neat analytical solu...To further extend study on celestial attitude determination with strapdown star sensor from static into dynamic field, one prerequisite is to generate precise dynamic simulating star maps. First a neat analytical solution of the smearing trajectory caused by spacecraft attitude maneuver is deduced successfully, whose parameters cover the geometric size of optics, three-axis angular velocities and CCD integral time. Then for the first time the mathematical law and method are discovered about how to synthesize the two formulae of smearing trajectory and the static Gaussian distribution function （GDF） model, the key of which is a line integral with regard to the static GDF attenuated by a factor 1/Ls （Ls is the arc length of the smearing trajectory） along the smearing trajectory. The dynamic smearing model is then obtained, also in an analytical form. After that, three sets of typical simulating maps and data are simulated from this dynamic model manifesting the expected smearing effects, also compatible with the linear model as its special case of no boresight rotation. Finally, model validity tests on a rate turntable are carried out, which results in a mean correlation coefficient 0.920 0 between the camera images and the corresponding model simulated ones with the same parameters. The sufficient similarity verifies the validity of the dynamic smearing model. This model, after pa- rameter calibration, can serve as a front-end loop of the ground semi-physical simulation system for celestial attitude determination with strapdown star sensor.展开更多
Objective:To compare the sensitivity and specificity of direct fecal smear microscopy,culture,and polymerase chain reaction in the detection of Blastocystis sp.in human stool.Methods:Human stool samples were collected...Objective:To compare the sensitivity and specificity of direct fecal smear microscopy,culture,and polymerase chain reaction in the detection of Blastocystis sp.in human stool.Methods:Human stool samples were collected from a community in San Isidro,Rodriguez,Rizal,Philippines.These samples were subjected to direct fecal smear microscopy,culture and polymerase chain reaction to detect the presence of Blastocystis sp.Results:Of the 110 stool samples collected,28(25%)were detected positive for the presence of Blastocystis sp.by two or more tests.Culture method detected the highest number of Blastocystis-positive stool samples(n=36),followed by PCR of DNA extracted from culture(n=26),PCR of DNA extracted from stool(n=10),and direct fecal smear(n=9).Compared to culture,the sensitivity of the other detection methods were 66.7%for PCR from culture and 19.4%for both PCR from stool and direct fecal smear.Specificity of the methods was high,with PCR from culture and direct fecal smear having97.3%,while PCR from stool at 95.9%.Conclusions:In this study,in vitro culture is the best method for detecting Blastocystis sp.in human stool samples.展开更多
Damage smear method(DSM)is adopted to study trans-scale progressive rock failure process,based on statistical meso-damage model and finite element solver.The statistical approach is utilized to reflect the mesoscopic ...Damage smear method(DSM)is adopted to study trans-scale progressive rock failure process,based on statistical meso-damage model and finite element solver.The statistical approach is utilized to reflect the mesoscopic rock heterogeneity.The constitutive law of representative volume element(RVE)is established according to continuum damage mechanics in which double-damage criterion is considered.The damage evolution and accumulation of RVEs are used to reveal the macroscopic rock failure characteristics.Each single RVE will be represented by one unique element.The initiation,propagation and coalescence of meso-to macro-cracks are captured by smearing failed elements.The above ideas are formulated into the framework of the DSM and programed into self-developed rock failure process analysis(RFPA)software.Two laboratory-scale examples are conducted and the well-known engineering-scale tests,i.e.Atomic Energy of Canada Limited’s(AECL’s)Underground Research Laboratory(URL)tests,are used for verification.It shows that the simulation results match with other experimental results and field observations.展开更多
Summary： This study was aimed to evaluate the effectiveness of solution form of 17% ethylenediaminetetraacetic acid （EDTA） on removing smear layer of root canals at different exposure time periods and to provide sc...Summary： This study was aimed to evaluate the effectiveness of solution form of 17% ethylenediaminetetraacetic acid （EDTA） on removing smear layer of root canals at different exposure time periods and to provide scientific basis for EDTA as a choice of root canal irrigation in clinical practice. Twenty-five single-rooted teeth were randomly divided into 5 groups： control group （group A） was given 2.5% NaOC1, and 4 experimental groups were given 2.5% NaOC1 and 17% EDTA, including groups B, C, D and E with exposure time of 1, 3, 5 and 7 min, respectively. After preparation of the root canals, the teeth were split along their longitudinal axis, and the root sections were examined under scanning elec- tron microscope for evaluation of smear layer removal and erosion on the surface of the root canal walls. The specimens in group B showed presence of smear layer on the walls of the root canal with no statistical difference from that in group A （P〉0.05）. In groups C and D, partial removal of smear layer was obtained, and there was no significant difference between the two groups （P〉0.05）, but there was significant difference in removal of smear layer between group C and group B （P〈0.05）. Root canal walls in group E specimens showed almost complete removal of smear layer, and the removal of smear layer was significantly different from that in group D （P〈0.01）. There was no significant change in the structure of the surface of root canal for each sample. It was concluded that combined irrigation with 17% EDTA and 2.5% NaOC1 could remove the smear layer with no significant alteration in dentinal structure when the chelating agent was applied for 7 min. At 3 and 5 min of application, partial removal of smear layer was observed and at 1 min negligible removal of smear layer was achieved.展开更多
Objective To compare the performance of MTBDRplus V2 and Xpert MTB/RIF for detecting smear negative pulmonary tuberculosis （PTB）. Methods Clinical PTB suspects were enrolled consecutively in Anhui Chest Hospital and...Objective To compare the performance of MTBDRplus V2 and Xpert MTB/RIF for detecting smear negative pulmonary tuberculosis （PTB）. Methods Clinical PTB suspects were enrolled consecutively in Anhui Chest Hospital and Xi＇an Chest Hospital from January to December in 2014. The sputum samples of smear negative PTB suspects were collected and decontaminated. The sediment was used to conduct MTBDRplus V2, Xpert MTB/RIF and drug susceptibility test （DST）. All the samples with discrepant drug susceptibility result between molecular methods and phenotypic method were confirmed by DNA sequencing. Results A total of 1973 cases were enrolled in this study. The detection rates of Mycobacterium tuberculosis complex （MTBC） by MTBDRplus V2 and Xpert MTB/RIF were 27.67% and 27.98%, respectively. When setting MGIT culture result as a gold standard, the sensitivity and specificity of MTBDRplus V2 were 86.74% and 93.84%, and the sensitivity and specificity of Xpert MTB/RIF were 86.55% and 93.43%, respectively. For the detection of the resistance to rifampin, the sensitivity and specificity of MTBDRplus V2 were 94.34% and 96.62%, and the sensitivity and specificity of Xpert MTB/RIF were 88.68% and 95.96%, respectively. For the detection of the resistance to isoniazid, the sensitivity and specificity of MTBDRplus V2 were 77.38% and 98.02%, respectively. Conclusion MTBDRplus V2 and Xpert MTB/RIF can be used to detect MTBC in smear negative samples with satisfactory performance.展开更多
基金The authors wish to acknowledge the generous financial sup-port from the Singapore Maritime Institute(SMI)for this research within the project‘Evaluation of In-situ Consolidation of Dredged and Excavated Materials at Reclaimed Next Generation Tuas Port’(Project ID:SMI-2018-MA-01).
文摘Vertical drains are used to accelerate consolidation of clays in ground improvement projects.Smear zones exist around these drains,where permeability is reduced due to soil disturbance caused by the installation process.Hansbo solution is widely used in practice to consider the effects of drain discharge capacity and smear on the consolidation process.In this study,a computationally efficient diameter reduction method(DRM)obtained from the Hansbo solution is proposed to consider the smear effect without the need to model the smear zone physically.Validated by analytical and numerical results,a diameter reduction factor is analytically derived to reduce the diameter of the drain,while achieving similar solutions of pore pressure dissipation profile as the classical full model of the smear zone and drain.With the DRM,the excess pore pressure u obtained from the reduced drain in the original un-disturbed soil zone is accurate enough for practical applications in numerical models.Such performance of DRM is independent of soil material property.Results also show equally accurate performance of DRM under conditions of multi-layered soils and coupled radial-vertical groundwater flow.
文摘Pneumcystis jirovecii is a pathogen that causes Pneumocystis pneumonia (PCP), an infection in (HIV/ADS) and other immunocompromised patients. The rare reports of P. jirovecii pneumonia in sub-Saharan Africa are controversial due to the high HIV/AIDS seropositivity. The study determined the significance of P. jirovecii in TB smear negative retreatment patients at the Coast General Teaching Referral Hospital-Mombasa. Sputum samples were subjected to toluidine blue O(TBO) stain for microscopy and polymerase chain reaction (PCR). A total of 100 TB smear negative participants were enrolled in the study and expectorated sputum was collected. Out of the 100 patients, 63 men and 37 women. Patients aged 31 to 53 made up 62% of the patients. The patients aged 31 to 53 made up 75% of the patients (Min = 11y, Max = 85y). The median age of the patients was 42 years. Nested PCR has a prevalence of 41% (41 instances). TBO staining has a prevalence of 29% (29 instances). Detecting an additional 13 more patients than toluidine O staining technique. The sensitivity of toluidine blue O staining was 33.82%, which indicates that it correctly identified 33.82% of true positive cases compared to PCR. The specificity of toluidine blue O staining was 97.82%, indicating that it had a high ability to correctly identify true negative cases compared to PCR, suggesting that it was good at ruling out non-P. jirovecii cases. The study confirms that P. jirovecii is as a significant cause of persistent symptoms in TB patients that could be responsible for persistent symptoms despite TB treatment. We recommend fungal diagnostics in such patients before retreatment.
基金supported by the 863 National Plan Foundation of China under Grant No.2007AA01Z333 and Special Grand National Project of China under Grant No.2009ZX02204-008.
文摘Blood smear test is the basic method of blood cytology and is also a standard medical test that can help diagnose various conditions and diseases.Morphological examination is the gold stan-dard to determine pathological changes in blood cell morphology.In the biology and medicine automation trend,blood smears'automated management and analysis is very necessary.An online blood smear automatic microscopic image detection system has been constructed.It includes an online blood smear automatic producing part and a blood smear automatic micro-scopic image detection part.Online identity authentication is at the core of the system.The identifiers printed online always present dot matrix digit code(DMDC)whose stroke is not continuous.Considering the particularities of DMDC and the complexities of online application environment,an online identity authentication method for blood smear with heterological theory is proposed.By synthesizing the certain regional features according to the heterological theory,high identification accuracy and high speed have been guaranteed with few features required.In the experiment,the suficient correct matches bet ween the tube barcode and the identification result verified its feasibility and validity.
文摘To further extend study on celestial attitude determination with strapdown star sensor from static into dynamic field, one prerequisite is to generate precise dynamic simulating star maps. First a neat analytical solution of the smearing trajectory caused by spacecraft attitude maneuver is deduced successfully, whose parameters cover the geometric size of optics, three-axis angular velocities and CCD integral time. Then for the first time the mathematical law and method are discovered about how to synthesize the two formulae of smearing trajectory and the static Gaussian distribution function （GDF） model, the key of which is a line integral with regard to the static GDF attenuated by a factor 1/Ls （Ls is the arc length of the smearing trajectory） along the smearing trajectory. The dynamic smearing model is then obtained, also in an analytical form. After that, three sets of typical simulating maps and data are simulated from this dynamic model manifesting the expected smearing effects, also compatible with the linear model as its special case of no boresight rotation. Finally, model validity tests on a rate turntable are carried out, which results in a mean correlation coefficient 0.920 0 between the camera images and the corresponding model simulated ones with the same parameters. The sufficient similarity verifies the validity of the dynamic smearing model. This model, after pa- rameter calibration, can serve as a front-end loop of the ground semi-physical simulation system for celestial attitude determination with strapdown star sensor.
基金supported by a research grant from the Office of the Vice-Chancellor for Research and Development,University of the Philippines-Diliman(Grant No.101007 PNSE)to W.L.R.and H.J.S
文摘Objective:To compare the sensitivity and specificity of direct fecal smear microscopy,culture,and polymerase chain reaction in the detection of Blastocystis sp.in human stool.Methods:Human stool samples were collected from a community in San Isidro,Rodriguez,Rizal,Philippines.These samples were subjected to direct fecal smear microscopy,culture and polymerase chain reaction to detect the presence of Blastocystis sp.Results:Of the 110 stool samples collected,28(25%)were detected positive for the presence of Blastocystis sp.by two or more tests.Culture method detected the highest number of Blastocystis-positive stool samples(n=36),followed by PCR of DNA extracted from culture(n=26),PCR of DNA extracted from stool(n=10),and direct fecal smear(n=9).Compared to culture,the sensitivity of the other detection methods were 66.7%for PCR from culture and 19.4%for both PCR from stool and direct fecal smear.Specificity of the methods was high,with PCR from culture and direct fecal smear having97.3%,while PCR from stool at 95.9%.Conclusions:In this study,in vitro culture is the best method for detecting Blastocystis sp.in human stool samples.
基金supported in part by the National Natural Science Foundation of China (Grant Nos.51679028 and 51879034)Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology (Grant No. SKLGDUEK1804)the Fundamental Research Funds for the Central Universities (Grant No.DUT18JC10)
文摘Damage smear method(DSM)is adopted to study trans-scale progressive rock failure process,based on statistical meso-damage model and finite element solver.The statistical approach is utilized to reflect the mesoscopic rock heterogeneity.The constitutive law of representative volume element(RVE)is established according to continuum damage mechanics in which double-damage criterion is considered.The damage evolution and accumulation of RVEs are used to reveal the macroscopic rock failure characteristics.Each single RVE will be represented by one unique element.The initiation,propagation and coalescence of meso-to macro-cracks are captured by smearing failed elements.The above ideas are formulated into the framework of the DSM and programed into self-developed rock failure process analysis(RFPA)software.Two laboratory-scale examples are conducted and the well-known engineering-scale tests,i.e.Atomic Energy of Canada Limited’s(AECL’s)Underground Research Laboratory(URL)tests,are used for verification.It shows that the simulation results match with other experimental results and field observations.
基金supported by the Fundamental Research Funds for the Central Universities,China(No.2010JC030)
文摘Summary： This study was aimed to evaluate the effectiveness of solution form of 17% ethylenediaminetetraacetic acid （EDTA） on removing smear layer of root canals at different exposure time periods and to provide scientific basis for EDTA as a choice of root canal irrigation in clinical practice. Twenty-five single-rooted teeth were randomly divided into 5 groups： control group （group A） was given 2.5% NaOC1, and 4 experimental groups were given 2.5% NaOC1 and 17% EDTA, including groups B, C, D and E with exposure time of 1, 3, 5 and 7 min, respectively. After preparation of the root canals, the teeth were split along their longitudinal axis, and the root sections were examined under scanning elec- tron microscope for evaluation of smear layer removal and erosion on the surface of the root canal walls. The specimens in group B showed presence of smear layer on the walls of the root canal with no statistical difference from that in group A （P〉0.05）. In groups C and D, partial removal of smear layer was obtained, and there was no significant difference between the two groups （P〉0.05）, but there was significant difference in removal of smear layer between group C and group B （P〈0.05）. Root canal walls in group E specimens showed almost complete removal of smear layer, and the removal of smear layer was significantly different from that in group D （P〈0.01）. There was no significant change in the structure of the surface of root canal for each sample. It was concluded that combined irrigation with 17% EDTA and 2.5% NaOC1 could remove the smear layer with no significant alteration in dentinal structure when the chelating agent was applied for 7 min. At 3 and 5 min of application, partial removal of smear layer was observed and at 1 min negligible removal of smear layer was achieved.
文摘Objective To compare the performance of MTBDRplus V2 and Xpert MTB/RIF for detecting smear negative pulmonary tuberculosis （PTB）. Methods Clinical PTB suspects were enrolled consecutively in Anhui Chest Hospital and Xi＇an Chest Hospital from January to December in 2014. The sputum samples of smear negative PTB suspects were collected and decontaminated. The sediment was used to conduct MTBDRplus V2, Xpert MTB/RIF and drug susceptibility test （DST）. All the samples with discrepant drug susceptibility result between molecular methods and phenotypic method were confirmed by DNA sequencing. Results A total of 1973 cases were enrolled in this study. The detection rates of Mycobacterium tuberculosis complex （MTBC） by MTBDRplus V2 and Xpert MTB/RIF were 27.67% and 27.98%, respectively. When setting MGIT culture result as a gold standard, the sensitivity and specificity of MTBDRplus V2 were 86.74% and 93.84%, and the sensitivity and specificity of Xpert MTB/RIF were 86.55% and 93.43%, respectively. For the detection of the resistance to rifampin, the sensitivity and specificity of MTBDRplus V2 were 94.34% and 96.62%, and the sensitivity and specificity of Xpert MTB/RIF were 88.68% and 95.96%, respectively. For the detection of the resistance to isoniazid, the sensitivity and specificity of MTBDRplus V2 were 77.38% and 98.02%, respectively. Conclusion MTBDRplus V2 and Xpert MTB/RIF can be used to detect MTBC in smear negative samples with satisfactory performance.
