The Carboniferous reservoir in KJ oilfield is a carbonate reservoir with extremely low porosity and permeability and high-pressure. The reservoir has severe heterogeneity, is deeply buried, has complex master control ...The Carboniferous reservoir in KJ oilfield is a carbonate reservoir with extremely low porosity and permeability and high-pressure. The reservoir has severe heterogeneity, is deeply buried, has complex master control factors, is covered with thick salt, all of which result in the serious distortion of reflection time and amplitudes under the salt, the poor seismic imaging, and the low S/N ratio and resolution. The key to developing this kind of reservoir is to correctly predict the distribution of highly profitable oil zones. In this paper we start by analyzing the master control factors, perform seismic-log calibration, optimize the seismic attributes indicating the lithofacies, karst, petrophysical properties, and fractures, and combine these results with the seismic, geology, log, oil reservoir engineering, and well data. We decompose the seismic prediction into six key areas： structural interpretation, prediction of lithofacies, karst, petrophysical properties, fractures, and then perform an integrated assessment. First, based on building the models of faults and fractures, sedimentary facies, and karst, we predict the distribution of the most favorable reservoir zones qualitatively. Then, using multi-parameter inversion and integrated multi-attribute analysis, we predict the favorable reservoir distribution quantitatively and semi-quantitatively to clarify the distribution of high-yield zones. We finally have a reliable basis for optimal selection of exploration and development targets.展开更多
Background Identifying the transmural extent of myocardial necrosis and the degree of myocardial viability in acute myocardial infarction （AMI） is important clinically. The aim of this study was to assess myocardial...Background Identifying the transmural extent of myocardial necrosis and the degree of myocardial viability in acute myocardial infarction （AMI） is important clinically. The aim of this study was to assess myocardial viability using two-dimensional speckle tracking imaging （2D-STI） in patients with AMI. Methods 2D-STI was performed at initial presentation, three days, and six months after primary percutaneous coronary intervention （PCI） in 30 patients with AMI, who had a left anterior descending coronary artery （LAD） culprit lesion. In addition, 20 patients who had minimal stenotic lesions （〈 30% stenosis） on coronary angiography were also included in the control group. At six months dobutamine echocardiography was performed for viability assessment in seven segments of the LAD territory. According to the recovery of wall motion abnormality, segments were classified as viable or non-viable. Results A total of 131 segments were viable, and 44 were nonviable. Multivariate analysis revealed significant differences between the viable and nonviable segments in the peak systolic strain, the peak systolic strain rate at initial presentation, and peak systolic strain rate three days after primary PCI. Among these, the initial peak systolic strain rate had the highest predictive value for myocardial viability （hazard ratio： 31.22, P 〈 0.01）. Conclusions 2D-STI is feasible for assessing myocardial viability, and the peak systolic strain rate might be the most reliable predictor of myocardial viability in patients with AMI.展开更多
The heat generation behaviors of fatigue crack are deeply investigated under different preload forces combing numerical simulation and experiment.Firstly,a multi-contact simulation model is applied to stimulate the cr...The heat generation behaviors of fatigue crack are deeply investigated under different preload forces combing numerical simulation and experiment.Firstly,a multi-contact simulation model is applied to stimulate the crack surfaces contact and the horn-sample contact under ultrasonic excitation for calculating the temperature fields.Then,the ultrasonic infrared thermography testing and the microscope testing are carried out for the heat generation and the plastic deformation behaviors of crack region under different preload forces.On this basis,an indirect observation method based on dots distribution is proposed to estimate the plastic deformation on crack contact surfaces.The obtained results show that the temperature rise of crack region increases with the increase of preload force when the preload force is less than 250 N,while the temperature rise rapidly declines due to the plastic deformation on crack contact surfaces and the inhibition effect when the preload force is 280 N.Moreover,the plastic deformation does not lead to the crack propagation,but reduces the detection repeatability of fatigue crack.This work provides an effective method for optimizing testing conditions in practical testing processes,which will be helpful to the establishment of testing standards for batches of test objects in ultrasonic infrared thermography testing.展开更多
This study sought to investigate whether low dose dobutamine MRI can detect residual myocardial viability in patients with chronic myocardial infarction and left ventricular dysfunction. Methods. Eleven patients with ...This study sought to investigate whether low dose dobutamine MRI can detect residual myocardial viability in patients with chronic myocardial infarction and left ventricular dysfunction. Methods. Eleven patients with chronic myocardial infarction and left ventricular dysfunction were employed for identification of viable myocardium by cine MRI during dobutamine infusion. All patients underwent coronary angiography and left ventriculography, 18 FDG PET, MRI at rest and stress.The systolic wall thickening measured at rest and during stress was compared with the results of 18 FDG PET, respectively. Results. A significant difference of either dobutamine induced systolic wall thickening (SWth stress ) or dobutamine induced contractile reserve (ΔSWth= SWth stress - SWth rest ) was present between viable and scar regions (1 0±0 3 versus -0 3 ±0 1, P<0 01; 1 0±0 3 versus -0 2±0 2, P<0 01). Conclusions. Dobutamine induced contractile reserve can be predicted in the regions of akinesia or dyskinesia at rest when systolic wall thickening was 1 0 mm during dobutamine stimulation.展开更多
Clostridium septicum(C.septicum)gas gangrene is well documented in the literature,typically in the setting of trauma or immunosuppression.In this paper,we report a unique case of spontaneous clostridial myonecrosis in...Clostridium septicum(C.septicum)gas gangrene is well documented in the literature,typically in the setting of trauma or immunosuppression.In this paper,we report a unique case of spontaneous clostridial myonecrosis in a patient with Crohn's disease and sulfasalazineinduced neutropenia.The patient presented with left thigh pain,vomiting and diarrhea.Blood tests demonstrated a profound neutropenia,and magnetic resonance imaging of the thigh confirmed extensive myonecrosis.The patient underwent emergency hip disarticulation,followed by hemicolectomy.C.septicum was cultured from the blood.Following completion of antibiotic therapy,the patient developed myonecrosis of the right pectoral muscle necessitating further debridement,and remains on lifelong prophylactic antibiotic therapy.展开更多
The Torgiovannetto quarry(Assisi municipality,central Italy) is an example of a site where the natural equilibrium was altered by human activity,causing current slope instability phenomena which threaten two roadways ...The Torgiovannetto quarry(Assisi municipality,central Italy) is an example of a site where the natural equilibrium was altered by human activity,causing current slope instability phenomena which threaten two roadways important for the local transportation.The quarry front,having a height of about 140 m,is affected by a 182,000 m3 rockslide developed in intensely fractured limestone and is too large to be stabilized.In 2003 some tension cracks were detected in the vegetated area above the quarry upper sector.From then on,several monitoring campaigns were carried out by means of different instrumentations(topographic total station,extensometers,inclinometers,ground-based interferometric radar,laser scanner and infrared thermal camera),allowing researchers to accurately define the landslide area and volume.The latter's major displacements are localized in the eastern sector.The deformational field appears to be related to the seasonal rainfall.The landslide hazard associated with the worst case scenario was evaluated in terms of magnitude,intensity and triggering mechanism.For the definition of the possible runout process the DAN 3D code was employed.The simulation results were used in order to design and construct a retaining embankment.Furthermore,in order to preserve both the safety of the personnelinvolved in its realization and of the roadways users,an early warning system was implemented.The early warning system is based on daily-averaged displacement velocity thresholds.The alarm level is reached if the prediction based on the methods of Saito(1969) and Fukuzono(1985) forecasts an imminent rupture.展开更多
In view of the problem of false alarm in imaging space-based laser warning system, the effects of sunlight and lightning on the threaten laser detection and attack event determination are studied by analyzing and calc...In view of the problem of false alarm in imaging space-based laser warning system, the effects of sunlight and lightning on the threaten laser detection and attack event determination are studied by analyzing and calculating the radiant energy density and space-time feature of imaging spot, respectively. The results show that the main false alarm resourses of space- based laser warning system are sunlight and lightning. The sunlight should exposure the detector directly in one ninth of the satfllite orbital period, and the imaging spot of sun is similar to the attack laser. The lightning imaging spot is similar to the illumination laser. About 1.4 lightning events can occur in the field of view （FOV） of the warning system per second. It could not discriminate spots of sun, lightning and threaten laser by the frame subtraction technology.展开更多
Background Most incidental gastric polyps identified during upper endoscopy are considered low-risk.However,current guidelines recommend sampling all gastric polyps for histopathologic analysis.We aimed to devise a si...Background Most incidental gastric polyps identified during upper endoscopy are considered low-risk.However,current guidelines recommend sampling all gastric polyps for histopathologic analysis.We aimed to devise a simple narrow-band imaging(NBI)classification to reduce the need for routine biopsies of low-risk gastric polyps.Methods Pairs of NBI and white-light images were collected from 73 gastric polyps for which concurrent histopathologic diagnosis was available.A diagnostic accuracy cohort study was performed.Two blinded endoscopists independently analysed NBI features of each polyp for color,vessel pattern,surface pattern,and any combinations thereof to develop a classification scheme to differentiate low-risk polyps(fundic-gland or hyperplastic)from high-risk polyps(adenomatous or adenocarcinoma)and fundic-gland polyps(FGPs)from non-FGPs.Results An isolated lacy vessel pattern and a homogenous absence of surface pattern successfully differentiated low-risk from high-risk gastric polyps.Combining both descriptors into a single algorithm resulted in a negative predictive value(NPV)of 100%[95%confidence interval(CI):100%–100%],positive predictive value(PPV)of 13.7%(95%CI:2.6–24.8),sensitivity of 100%(95%CI:100%–100%),and specificity of 53.7%(95%CI:45.3%–62.0%)for high-risk polyps.This would reduce the number of polyps requiring biopsy by 50%,while still capturing all high-risk polyps.Regarding FGPs,using a rule not to biopsy polyps with isolated lacy vessels resulted in a 94.9%NPV(95%CI:89.2%–100%),63.2%PPV(95%CI:47.2%–79.2%),94.8%sensitivity(95%CI:89.5%–100%),and 63.6%specificity(95%CI:51.3%–76.0%)for non-FGPs.Conclusion In this derivation cohort study,NBI is helpful for differentiating between high-risk and low-risk gastric polyps,thereby reducing the need for routine sampling of low-risk polyps.These results need to be validated in a separate test population.展开更多
文摘The Carboniferous reservoir in KJ oilfield is a carbonate reservoir with extremely low porosity and permeability and high-pressure. The reservoir has severe heterogeneity, is deeply buried, has complex master control factors, is covered with thick salt, all of which result in the serious distortion of reflection time and amplitudes under the salt, the poor seismic imaging, and the low S/N ratio and resolution. The key to developing this kind of reservoir is to correctly predict the distribution of highly profitable oil zones. In this paper we start by analyzing the master control factors, perform seismic-log calibration, optimize the seismic attributes indicating the lithofacies, karst, petrophysical properties, and fractures, and combine these results with the seismic, geology, log, oil reservoir engineering, and well data. We decompose the seismic prediction into six key areas： structural interpretation, prediction of lithofacies, karst, petrophysical properties, fractures, and then perform an integrated assessment. First, based on building the models of faults and fractures, sedimentary facies, and karst, we predict the distribution of the most favorable reservoir zones qualitatively. Then, using multi-parameter inversion and integrated multi-attribute analysis, we predict the favorable reservoir distribution quantitatively and semi-quantitatively to clarify the distribution of high-yield zones. We finally have a reliable basis for optimal selection of exploration and development targets.
文摘Background Identifying the transmural extent of myocardial necrosis and the degree of myocardial viability in acute myocardial infarction （AMI） is important clinically. The aim of this study was to assess myocardial viability using two-dimensional speckle tracking imaging （2D-STI） in patients with AMI. Methods 2D-STI was performed at initial presentation, three days, and six months after primary percutaneous coronary intervention （PCI） in 30 patients with AMI, who had a left anterior descending coronary artery （LAD） culprit lesion. In addition, 20 patients who had minimal stenotic lesions （〈 30% stenosis） on coronary angiography were also included in the control group. At six months dobutamine echocardiography was performed for viability assessment in seven segments of the LAD territory. According to the recovery of wall motion abnormality, segments were classified as viable or non-viable. Results A total of 131 segments were viable, and 44 were nonviable. Multivariate analysis revealed significant differences between the viable and nonviable segments in the peak systolic strain, the peak systolic strain rate at initial presentation, and peak systolic strain rate three days after primary PCI. Among these, the initial peak systolic strain rate had the highest predictive value for myocardial viability （hazard ratio： 31.22, P 〈 0.01）. Conclusions 2D-STI is feasible for assessing myocardial viability, and the peak systolic strain rate might be the most reliable predictor of myocardial viability in patients with AMI.
基金Project(2019M650262)supported by the China Postdoctoral Science FoundationProject(92060106)supported by the Major Research Plan of National Natural Science Foundation of ChinaProject(201803U8003)supported by the China Aeronautical Science Foundation。
文摘The heat generation behaviors of fatigue crack are deeply investigated under different preload forces combing numerical simulation and experiment.Firstly,a multi-contact simulation model is applied to stimulate the crack surfaces contact and the horn-sample contact under ultrasonic excitation for calculating the temperature fields.Then,the ultrasonic infrared thermography testing and the microscope testing are carried out for the heat generation and the plastic deformation behaviors of crack region under different preload forces.On this basis,an indirect observation method based on dots distribution is proposed to estimate the plastic deformation on crack contact surfaces.The obtained results show that the temperature rise of crack region increases with the increase of preload force when the preload force is less than 250 N,while the temperature rise rapidly declines due to the plastic deformation on crack contact surfaces and the inhibition effect when the preload force is 280 N.Moreover,the plastic deformation does not lead to the crack propagation,but reduces the detection repeatability of fatigue crack.This work provides an effective method for optimizing testing conditions in practical testing processes,which will be helpful to the establishment of testing standards for batches of test objects in ultrasonic infrared thermography testing.
文摘This study sought to investigate whether low dose dobutamine MRI can detect residual myocardial viability in patients with chronic myocardial infarction and left ventricular dysfunction. Methods. Eleven patients with chronic myocardial infarction and left ventricular dysfunction were employed for identification of viable myocardium by cine MRI during dobutamine infusion. All patients underwent coronary angiography and left ventriculography, 18 FDG PET, MRI at rest and stress.The systolic wall thickening measured at rest and during stress was compared with the results of 18 FDG PET, respectively. Results. A significant difference of either dobutamine induced systolic wall thickening (SWth stress ) or dobutamine induced contractile reserve (ΔSWth= SWth stress - SWth rest ) was present between viable and scar regions (1 0±0 3 versus -0 3 ±0 1, P<0 01; 1 0±0 3 versus -0 2±0 2, P<0 01). Conclusions. Dobutamine induced contractile reserve can be predicted in the regions of akinesia or dyskinesia at rest when systolic wall thickening was 1 0 mm during dobutamine stimulation.
文摘Clostridium septicum(C.septicum)gas gangrene is well documented in the literature,typically in the setting of trauma or immunosuppression.In this paper,we report a unique case of spontaneous clostridial myonecrosis in a patient with Crohn's disease and sulfasalazineinduced neutropenia.The patient presented with left thigh pain,vomiting and diarrhea.Blood tests demonstrated a profound neutropenia,and magnetic resonance imaging of the thigh confirmed extensive myonecrosis.The patient underwent emergency hip disarticulation,followed by hemicolectomy.C.septicum was cultured from the blood.Following completion of antibiotic therapy,the patient developed myonecrosis of the right pectoral muscle necessitating further debridement,and remains on lifelong prophylactic antibiotic therapy.
基金the National Department of Civil Protection, the Perugia Province and the Umbria Region for funding the work behind this research
文摘The Torgiovannetto quarry(Assisi municipality,central Italy) is an example of a site where the natural equilibrium was altered by human activity,causing current slope instability phenomena which threaten two roadways important for the local transportation.The quarry front,having a height of about 140 m,is affected by a 182,000 m3 rockslide developed in intensely fractured limestone and is too large to be stabilized.In 2003 some tension cracks were detected in the vegetated area above the quarry upper sector.From then on,several monitoring campaigns were carried out by means of different instrumentations(topographic total station,extensometers,inclinometers,ground-based interferometric radar,laser scanner and infrared thermal camera),allowing researchers to accurately define the landslide area and volume.The latter's major displacements are localized in the eastern sector.The deformational field appears to be related to the seasonal rainfall.The landslide hazard associated with the worst case scenario was evaluated in terms of magnitude,intensity and triggering mechanism.For the definition of the possible runout process the DAN 3D code was employed.The simulation results were used in order to design and construct a retaining embankment.Furthermore,in order to preserve both the safety of the personnelinvolved in its realization and of the roadways users,an early warning system was implemented.The early warning system is based on daily-averaged displacement velocity thresholds.The alarm level is reached if the prediction based on the methods of Saito(1969) and Fukuzono(1985) forecasts an imminent rupture.
文摘In view of the problem of false alarm in imaging space-based laser warning system, the effects of sunlight and lightning on the threaten laser detection and attack event determination are studied by analyzing and calculating the radiant energy density and space-time feature of imaging spot, respectively. The results show that the main false alarm resourses of space- based laser warning system are sunlight and lightning. The sunlight should exposure the detector directly in one ninth of the satfllite orbital period, and the imaging spot of sun is similar to the attack laser. The lightning imaging spot is similar to the illumination laser. About 1.4 lightning events can occur in the field of view （FOV） of the warning system per second. It could not discriminate spots of sun, lightning and threaten laser by the frame subtraction technology.
文摘Background Most incidental gastric polyps identified during upper endoscopy are considered low-risk.However,current guidelines recommend sampling all gastric polyps for histopathologic analysis.We aimed to devise a simple narrow-band imaging(NBI)classification to reduce the need for routine biopsies of low-risk gastric polyps.Methods Pairs of NBI and white-light images were collected from 73 gastric polyps for which concurrent histopathologic diagnosis was available.A diagnostic accuracy cohort study was performed.Two blinded endoscopists independently analysed NBI features of each polyp for color,vessel pattern,surface pattern,and any combinations thereof to develop a classification scheme to differentiate low-risk polyps(fundic-gland or hyperplastic)from high-risk polyps(adenomatous or adenocarcinoma)and fundic-gland polyps(FGPs)from non-FGPs.Results An isolated lacy vessel pattern and a homogenous absence of surface pattern successfully differentiated low-risk from high-risk gastric polyps.Combining both descriptors into a single algorithm resulted in a negative predictive value(NPV)of 100%[95%confidence interval(CI):100%–100%],positive predictive value(PPV)of 13.7%(95%CI:2.6–24.8),sensitivity of 100%(95%CI:100%–100%),and specificity of 53.7%(95%CI:45.3%–62.0%)for high-risk polyps.This would reduce the number of polyps requiring biopsy by 50%,while still capturing all high-risk polyps.Regarding FGPs,using a rule not to biopsy polyps with isolated lacy vessels resulted in a 94.9%NPV(95%CI:89.2%–100%),63.2%PPV(95%CI:47.2%–79.2%),94.8%sensitivity(95%CI:89.5%–100%),and 63.6%specificity(95%CI:51.3%–76.0%)for non-FGPs.Conclusion In this derivation cohort study,NBI is helpful for differentiating between high-risk and low-risk gastric polyps,thereby reducing the need for routine sampling of low-risk polyps.These results need to be validated in a separate test population.
