The recovery factor from tight gas reservoirs is typically less than 15%, even with multistage hydrauhc tractunng stimulation. Such low recovery is exacerbated in tight gas condensate reservoirs, where the depletion o...The recovery factor from tight gas reservoirs is typically less than 15%, even with multistage hydrauhc tractunng stimulation. Such low recovery is exacerbated in tight gas condensate reservoirs, where the depletion of gas leaves the valuable condensate behind. In this paper, three enhanced gas recovery （EGR） methods including produced gas injection, CO2 injection and water injection are investigated to increase the well productivity for a tight gas condensate reservoir in the Montney Formation, Canada. The production performance of the three EGR methods is compared and their economic feasibility is evaluated. Sensitivity analysis of the key factors such as primary production duration, bottom-hole pressures, and fracture conductivity is conducted and their effects on the well production performance are analyzed. Results show that, compared with the simple depletion method, both the cumulative gas and condensate production increase with fluids injected. Produced gas injection leads to both a higher gas and condensate production compared with those of the CO2 injection, while waterflooding suffers from injection difficulty and the corresponding low sweep efficiency. Meanwhile, the injection cost is lower for the produced gas injection due to the on-site available gas source and minimal transport costs, gaining more economic benefits than the other EGR methods.展开更多
The mechanisms occurring when the switched temperature technique is applied, as an accelerated enhanced low dose rate sensitivity （ELDRS） test technique, are investigated in terms of a specially designed gate-contro...The mechanisms occurring when the switched temperature technique is applied, as an accelerated enhanced low dose rate sensitivity （ELDRS） test technique, are investigated in terms of a specially designed gate-controlled lateral PNP transistor （GLPNP） that used to extract the interface traps （Nit） and oxide trapped charges （Not）. Electrical characteristics in GLPNP transistors induced by 60Co gamma irradiation are measured in situ as a function of total dose, showing that generation of Nit in the oxide is the primary cause of base current variations for the GLPNP. Based on the analysis of the variations of Nit and Not, with switching the temperature, the properties of accelerated protons release and suppressed protons loss play critical roles in determining the increased Nit formation leading to the base current degradation with dose accumulation. Simultaneously the hydrogen cracking mechanisms responsible for additional protons release are related to the neutralization of Not extending enhanced Nit buildup. In this study the switched temperature irradiation has been employed to conservatively estimate the ELDRS of GLPNP, which provides us with a new insight into the test technique for ELDRS.展开更多
This study was undertaken to investigate the correlation of the enhancement degree on contrast-enhanced ultrasound(CEUS) with the histopathology of carotid plaques and the serum high sensitive C-reactive protein(hs-CR...This study was undertaken to investigate the correlation of the enhancement degree on contrast-enhanced ultrasound(CEUS) with the histopathology of carotid plaques and the serum high sensitive C-reactive protein(hs-CRP) levels in patients undergoing carotid endarterectomy(CEA). Carotid CEUS was performed preoperatively in 115 patients who would undergo CEA, and the enhancement degree of the carotid plaques was evaluated by both the visual semiquantitative analysis and the quantitative time-intensity curve analysis. Serum hs-CRP levels were detected using the particle-enhanced immunoturbidimetric assay also before the operation. Additionally, the carotid plaque samples were subjected to histopathological examination postoperatively. The density of neovessels and the number of macrophages in the plaques were assessed by immunohistochemistry. The results showed that among the 115 patients, grade 0 plaque contrast enhancement was noted in 35 patients, grade 1 in 48 patients and grade 2 in 32 patients. The degree of plaque enhancement, the density of neovessels, the number of macrophages, and the hs-CRP levels were highest in the grade 2 patients. Correlation analysis showed that the enhancement degree of the carotid plaques was closely related to the immunohistochemical parameters of the plaques and the serum hs-CRP levels. It was suggested that the carotid plaque enhancement on CEUS can be used to evaluate the vulnerability of carotid plaques.展开更多
Objective:Late gadolinium enhancement(LGE) patterns of cardiovascular magnetic resonance (CMR) relying on PSIR(phase-sensitive inversion recovery sequence) techniques had been used to determine the characteristics of ...Objective:Late gadolinium enhancement(LGE) patterns of cardiovascular magnetic resonance (CMR) relying on PSIR(phase-sensitive inversion recovery sequence) techniques had been used to determine the characteristics of LGE in apical hypertrophic cardiomyopathy(ApHCM). Methods:Forty patients pure ApHCM[age,(60.2±10.4) years,31 men]were enrolled.LGE images were acquired using PSIR,and analyzed using a 17-segment model.Summing the LGE areas in all short axis slices yielded the total volume of late enhancement,which was subsequently presented as a proportion of total LV myocardium(%LGE).Results:Mean maximal apical wall thickness was(17.9±2.3) mm,and mean left ventricular(LV) ejection fraction was(67.7±8.0)%.LGE was detected in 130 segments of 30 patients(75.0%),occupying(4.9±5.5)% of LV myocardium.LGE was mainly detected at the junction between left and right ventricles in 12(30%) and at the apex in 28(70%),although LGE-positive areas were widely distributed,and not limited to the apex.Focal LGE at the non-hypertrophic LV segments was found in some ApHCM patients,even without LGE of hypertrophied apical segments.Conclusions:LGE was frequently observed not only in the thickened apex of the heart but also in other LV segments,irrespective of the presence or absence of hypertrophy.The simple presence of LGE on CMR was not representative of adverse prognosis in this population.展开更多
In this article, the industrial process of CO_2 capture using monoethanolamine as an aqueous solvent was probed carefully from the mass transfer viewpoint. The simulation of this process was done using Rate-Base model...In this article, the industrial process of CO_2 capture using monoethanolamine as an aqueous solvent was probed carefully from the mass transfer viewpoint. The simulation of this process was done using Rate-Base model, based on two-film theory. The results were validated against real plant data. Compared to the operational unit, the error of calculating absorption percentage and CO_2 loading was estimated around 2%. The liquid temperature profiles calculated by the model agree well with the real temperature along the absorption tower, emphasizing the accuracy of this model. Operational sensitivity analysis of absorption tower was also done with the aim of determining sensitive parameters for the optimized design of absorption tower and optimized operational conditions. Hence,the sensitivity analysis was done for the flow rate of gas, the flow rate of solvent, flue gas temperature, inlet solvent temperature, CO_2 concentration in the flue gas, loading of inlet solvent, and MEA concentration in the solvent. CO_2 absorption percentage, the profile of loading, liquid temperature profile and finally profile of CO_2 mole fraction in gas phase along the absorption tower were studied. To elaborate mass transfer phenomena, enhancement factor, interfacial area, molar flux and liquid hold up were probed. The results show that regarding the CO_2 absorption, the most important parameter was the gas flow rate. Comparing liquid temperature profiles showed that the most important parameter affecting the temperature of the rich solvent was MEA concentration.展开更多
AIM:To compare the imaging results with histology and to evaluate the diagnostic sensitivity of imaging modalities for hepatocellular carcinoma(HCC)smaller than 2 cm.METHODS:Nodules smaller than 2 cm(n=34)revealed by ...AIM:To compare the imaging results with histology and to evaluate the diagnostic sensitivity of imaging modalities for hepatocellular carcinoma(HCC)smaller than 2 cm.METHODS:Nodules smaller than 2 cm(n=34)revealed by ultrasonography(US)in 29 patients with liver cirrhosis were analyzed.Histological diagnosis of HCC was performed by ultrasonographic guidance:moderately-differentiated HCC(n=24);well-differentiated HCC(n=10).The patterns disclosed by the four imaging modalities defined the conclusive diagnosis of HCC:(1)contrast-enhanced computed tomography(CECT),hypervascularity in the arterial phase and washout in the equilibrium phase;(2)Sonazoid contrast-enhanced US(CEUS),hypervascularity in the early vascular phase and defect in the Kupffer phase;(3)gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid(Gd-EOBDTPA)-enhanced magnetic resonance imaging(MRI),hypervascularity in the arterial phase and/or defect in the hepatobiliary phase;and(4)CT arterioportal angiography:hypervascularity by CT during arteriography and/ or perfusion defect by CT during arterial portography.RESULTS:Overall,the sensitivity of diagnosing HCC smaller than 2 cm was 52.9%(18/34)(95%CI:35.170.2)by CECT;67.6%(23/34)(95%CI:49.5-82.6)by Sonazoid CEUS;76.5%(26/34)(95%CI:58.8-89.3) by Gd-EOB-DTPA MRI;and 88.2%(30/34)(95%CI: 72.5-96.7)by CT arterioportal angiography.The diagnostic sensitivity of detecting moderately-differentiated HCC by CECT,Sonazoid CEUS,Gd-EOB-DTPA MRI and CT arterioportal angiography was 62.5%(15/24)(95%CI: 40.6-81.2),79.2%(19/24)(95%CI:57.8-92.9),75.0% (18/24)(95%CI:53.3-90.2)and 95.8%(23/24)(95% CI:78.9-99.9),respectively.A significant difference(P< 0.05)was observed between CECT and CT arterioportal angiography in all nodules.There was no difference between Sonazoid CEUS,Gd-EOB-DTPA MRI,and CT arterioportal angiography.The combined sensitivity of Sonazoid CEUS and Gd-EOB-DTPA MRI was 94.1%(32/34).CONCLUSION:Changing the main diagnostic modality for HCC smaller than 2 cm from CT arterioportal angiography to Sonazoid CEUS and Gd-EOB-DTPA MRI is recommended.展开更多
An exceptional-point(EP)enhanced fiber-optic bending sensor is reported.The sensor is implemented based on paritytime(PT)-symmetry using two coupled Fabry-Perot(FP)resonators consisting of three cascaded fiber Bragg g...An exceptional-point(EP)enhanced fiber-optic bending sensor is reported.The sensor is implemented based on paritytime(PT)-symmetry using two coupled Fabry-Perot(FP)resonators consisting of three cascaded fiber Bragg gratings(FBGs)inscribed in an erbium-ytterbium co-doped fiber(EYDF).The EP is achieved by controlling the pumping power to manipulate the gain and loss of the gain and loss FP resonators.Once a bending force is applied to the gain FP resonator to make the operation of the system away from its EP,frequency splitting occurs,and the frequency spacing is a nonlinear function of the bending curvature,with an increased slope near the EP.Thus,by measuring the frequency spacing,the bending information is measured with increased sensitivity.To achieve high-speed and high-resolution interrogation,the optical spectral response of the sensor is converted to the microwave domain by implementing a dual-passband microwave-photonic filter(MPF),with the spacing between the two passbands equal to that of the frequency splitting.The proposed sensor is evaluated experimentally.A curvature sensing range from 0.28 to 2.74 m^(−1) is achieved with an accuracy of 7.56×10^(−4 )m^(−1 )and a sensitivity of 1.32 GHz/m^(−1),which is more than 4 times higher than those reported previously.展开更多
目的:探讨3.0T磁共振流动敏感黑血序列三维T_(1)加权增强扫描(FSBB 3D CE-T_(1)WI)在脑转移瘤中的应用价值。方法:回顾性将2021年1月-2022年8月在本院就诊且经临床和影像检查证实的52例脑转移患者纳入研究。所有患者分别行颅脑FSBB 3D C...目的:探讨3.0T磁共振流动敏感黑血序列三维T_(1)加权增强扫描(FSBB 3D CE-T_(1)WI)在脑转移瘤中的应用价值。方法:回顾性将2021年1月-2022年8月在本院就诊且经临床和影像检查证实的52例脑转移患者纳入研究。所有患者分别行颅脑FSBB 3D CE-T_(1)WI、FSE CE-T_(1)WI和快速梯度回波序列三维T_(1)加权对比增强(FFE 3D CE-T_(1)WI)扫描,采用卡方检验或Fisher精确概率检验比较3个序列之间病灶检出率的差异。结果:经随访证实颅内转移灶总数为371个,FSBB 3D CE-T_(1)WI的检出率99.73%(370/371),FFE 3D CE-T_(1)WI的检出率为83.02%(308/371),FSE CE-T_(1)WI的检出率为78.44%(291/371),三者之间检出率的差异有统计学意义(χ^(2)=82.748,P<0.05)。分层分析:直径<3 mm的转移灶共160个,FSE CE-T_(1)WI、FFE 3D CE-T_(1)WI和FSBB 3D CE-T_(1)WI的检出率分别为50.62%、60.62%和99.37%,三个序列之间检出率的差异有统计学意义(χ^(2)=101.436,P<0.05);对于直径3~10 mm的转移灶,FSE CE-T_(1)WI、FFE 3D CE-T_(1)WI和FSBB 3D CE-T_(1)WI的检出率分别为99.38%、100%和100%,三个序列之间检出率的差异无统计学意义(P>0.05);对直径>10 mm的转移灶,三个序列的检出率均为100%,差异无统计学意义(P>0.05)。结论:FSBB 3D CE-T_(1)WI在检出脑转移瘤方面要优于常规和高分辨序列MR增强扫描,值得临床推广。展开更多
We investigate the sensitivity of the angular rotation measurement with the method of homodyne detection in SU(2) and SU(1,1) interferometers by employing orbital angular momentum(OAM). By combining a coherent beam wi...We investigate the sensitivity of the angular rotation measurement with the method of homodyne detection in SU(2) and SU(1,1) interferometers by employing orbital angular momentum(OAM). By combining a coherent beam with a vacuum beam in an SU(2) interferometer, we get the sensitivity of the angular rotation measurement as 1/(2N^(1/2)l). We can surpass the limit of the angular rotation measurement in an SU(1,1) interferometer by combining a coherent beam with a vacuum beam or a squeezed vacuum beam when the probe beam has OAM. Without injection, the sensitivity can reach 1/(2N^(1/2)l). In addition, by employing another construction of an SU(1,1) interferometer where the pump beam has OAM, with the same injection of an SU(1,1) interferometer, the sensitivity of the angular rotation measurement can be improved by a factor of 2, reaching 1/(4Nl). The results confirm the potential of this technology for precision measurements in angular rotation measurements.展开更多
Preoperative detection of lymph nodes（LNs） metastasis is always highly challenging for radiologists nowadays. The utility of quantitative dynamic contrast-enhanced magnetic resonance imaging（QDCE-MRI） in identifyi...Preoperative detection of lymph nodes（LNs） metastasis is always highly challenging for radiologists nowadays. The utility of quantitative dynamic contrast-enhanced magnetic resonance imaging（QDCE-MRI） in identifying LNs metastasis is not well understood. In the present study, 59 patients with histologically proven rectal carcinoma underwent preoperative QDCE-MRI. The short axis diameter ratio, long axis diameter ratio, short-to-long axis diameter ratio and QDEC-MRI parameters（Ktrans, Kep, fPV and Ve） values were compared between the non-metastatic（n=44） and metastatic（n=35） LNs groups based on pathological examination. Compared with the non-metastatic group, the metastatic group exhibited significantly higher short axis diameter（7.558±0.668 mm vs. 5.427±0.285 mm）, Ktrans（0.483±0.198 min-1 vs. 0.218±0.116 min^-1） and Ve（0.399±0.118 vs. 0.203±0.096） values（all P〈0.05）. The short-to-long axis diameter ratio, long axis diameter ratio, Kep and fPV values did not show significant differences between the two groups. In conclusion, our results showed that for LNs larger than 5 mm in rectal cancer, there are distinctive differences in the Ktrans and Ve values between the metastatic and non-metastatic LNs, suggesting that QDCE-MRI may be potentially helpful in identifying LNs status.展开更多
AIM: To assess the usefulness of contrast-enhanced harmonic endoscopic ultrasonography(CH-EUS) for lymph node metastasis in pancreatobiliary carcinoma.METHODS: All patients suspected of pancreatobiliary carcinoma with...AIM: To assess the usefulness of contrast-enhanced harmonic endoscopic ultrasonography(CH-EUS) for lymph node metastasis in pancreatobiliary carcinoma.METHODS: All patients suspected of pancreatobiliary carcinoma with visible lymph nodes after standard EUS between June, 2009 and January, 2012 were enrolled.In the primary analysis, patients with successful EUSfine needle aspiration(FNA) were included. The lymph nodes were assessed by several standard EUS variables(short and long axis lengths, shape, edge characteristic and echogenicity), color Doppler EUS variable [central intranodal blood vessel(CIV) presence] and CH-EUS variable(heterogeneous/homogeneous enhancement patterns). The diagnostic accuracy relative to EUSFNA was calculated. In the second analysis, N-stage diagnostic accuracy of CH-EUS was compared with EUS-FNA in patients who underwent surgical resection.RESULTS: One hundred and nine patients(143 lymph nodes) fulfilled the criteria. The short axis cutoff ≥ 13 mm predicted malignancy with a sensitivity and specificity of 72% and 85%, respectively. These values were 72% and 63% for the long axis cut-off ≥ 20 mm, 62% and 75% for the round shape variable, 81% and 30% for the sharp edge variable, 66% and 61% for the hypoechogenicity variable, 70% and 72% for the CIV-absent variable, and 83% and 91% for the heterogeneous CH-EUS-enhancement variable, respectively. CH-EUS was more accurate than standard and color Doppler EUS, except the short axis cut-off. Notably, three patients excluded because of EUS-FNA failure were correctly N-staged by CH-EUS.CONCLUSION: CH-EUS complements standard and color Doppler EUS and EUS-FNA for assessment of lymph node metastases.展开更多
The optical fibers,coated with plasmonic active metal films,represent the simple and unpretentious sensors,potentially useful for measurements of physical or chemical quantities and wide range of analytical applicatio...The optical fibers,coated with plasmonic active metal films,represent the simple and unpretentious sensors,potentially useful for measurements of physical or chemical quantities and wide range of analytical application.All fiber-based plasmonic sensors operate on the same physical principle based on changes in the position of the plasmon absorption peak induced by a variation of surrounding medium refractive index.However,the observed spectral differences are often weak,and thus an enhancement of sensor sensitivity is strongly required.In this paper,we propose the immobilization of gold nanoparticles with sharp edges on the thin gold layer,deposited on the multimode fiber surface for improvement of the sensor functionality.The morphological and compositional changes in the gold covered fiber surface were determined by using the atomic force microscopy,scanning electron microscopy,and energy-dispersive X-ray spectroscopy methods.As a result of gold nanoparticles immobilization,the pronounced plasmon energy concentration near the fiber surface occurred,thus enhancing the response of the proposed hybrid plasmonic system to the variation of ambient refractive index.The position of plasmon absorption in the case of the created plasmonic structure was shown to be more sensitive to the changes in the surrounding medium in comparison with the standard sensors based on the bare gold layer.展开更多
基金funding from Natural Sciences and Engineering Research Council of Canada (NSERC) for this researchsupport from the University of Calgary Beijing Research Site, a research initiative associated with the University of Calgary Global Research Initiative in Sustainable Low Carbon Unconventional Resources, the Kerui Group, and the Mitacs Accelerate program
文摘The recovery factor from tight gas reservoirs is typically less than 15%, even with multistage hydrauhc tractunng stimulation. Such low recovery is exacerbated in tight gas condensate reservoirs, where the depletion of gas leaves the valuable condensate behind. In this paper, three enhanced gas recovery （EGR） methods including produced gas injection, CO2 injection and water injection are investigated to increase the well productivity for a tight gas condensate reservoir in the Montney Formation, Canada. The production performance of the three EGR methods is compared and their economic feasibility is evaluated. Sensitivity analysis of the key factors such as primary production duration, bottom-hole pressures, and fracture conductivity is conducted and their effects on the well production performance are analyzed. Results show that, compared with the simple depletion method, both the cumulative gas and condensate production increase with fluids injected. Produced gas injection leads to both a higher gas and condensate production compared with those of the CO2 injection, while waterflooding suffers from injection difficulty and the corresponding low sweep efficiency. Meanwhile, the injection cost is lower for the produced gas injection due to the on-site available gas source and minimal transport costs, gaining more economic benefits than the other EGR methods.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U1532261 and 1630141)
文摘The mechanisms occurring when the switched temperature technique is applied, as an accelerated enhanced low dose rate sensitivity （ELDRS） test technique, are investigated in terms of a specially designed gate-controlled lateral PNP transistor （GLPNP） that used to extract the interface traps （Nit） and oxide trapped charges （Not）. Electrical characteristics in GLPNP transistors induced by 60Co gamma irradiation are measured in situ as a function of total dose, showing that generation of Nit in the oxide is the primary cause of base current variations for the GLPNP. Based on the analysis of the variations of Nit and Not, with switching the temperature, the properties of accelerated protons release and suppressed protons loss play critical roles in determining the increased Nit formation leading to the base current degradation with dose accumulation. Simultaneously the hydrogen cracking mechanisms responsible for additional protons release are related to the neutralization of Not extending enhanced Nit buildup. In this study the switched temperature irradiation has been employed to conservatively estimate the ELDRS of GLPNP, which provides us with a new insight into the test technique for ELDRS.
基金supported by the Natural Science Foundation of Zhejiang Province,China(No.LY13H180007)
文摘This study was undertaken to investigate the correlation of the enhancement degree on contrast-enhanced ultrasound(CEUS) with the histopathology of carotid plaques and the serum high sensitive C-reactive protein(hs-CRP) levels in patients undergoing carotid endarterectomy(CEA). Carotid CEUS was performed preoperatively in 115 patients who would undergo CEA, and the enhancement degree of the carotid plaques was evaluated by both the visual semiquantitative analysis and the quantitative time-intensity curve analysis. Serum hs-CRP levels were detected using the particle-enhanced immunoturbidimetric assay also before the operation. Additionally, the carotid plaque samples were subjected to histopathological examination postoperatively. The density of neovessels and the number of macrophages in the plaques were assessed by immunohistochemistry. The results showed that among the 115 patients, grade 0 plaque contrast enhancement was noted in 35 patients, grade 1 in 48 patients and grade 2 in 32 patients. The degree of plaque enhancement, the density of neovessels, the number of macrophages, and the hs-CRP levels were highest in the grade 2 patients. Correlation analysis showed that the enhancement degree of the carotid plaques was closely related to the immunohistochemical parameters of the plaques and the serum hs-CRP levels. It was suggested that the carotid plaque enhancement on CEUS can be used to evaluate the vulnerability of carotid plaques.
基金Supported by Haikou Key Science and Technology Project (2012-075)Haikou Science and Technology Planning Project(2009-049-1)Science and Technology Fund of Haikou Health Bureau(2010-SWY-13-058)
文摘Objective:Late gadolinium enhancement(LGE) patterns of cardiovascular magnetic resonance (CMR) relying on PSIR(phase-sensitive inversion recovery sequence) techniques had been used to determine the characteristics of LGE in apical hypertrophic cardiomyopathy(ApHCM). Methods:Forty patients pure ApHCM[age,(60.2±10.4) years,31 men]were enrolled.LGE images were acquired using PSIR,and analyzed using a 17-segment model.Summing the LGE areas in all short axis slices yielded the total volume of late enhancement,which was subsequently presented as a proportion of total LV myocardium(%LGE).Results:Mean maximal apical wall thickness was(17.9±2.3) mm,and mean left ventricular(LV) ejection fraction was(67.7±8.0)%.LGE was detected in 130 segments of 30 patients(75.0%),occupying(4.9±5.5)% of LV myocardium.LGE was mainly detected at the junction between left and right ventricles in 12(30%) and at the apex in 28(70%),although LGE-positive areas were widely distributed,and not limited to the apex.Focal LGE at the non-hypertrophic LV segments was found in some ApHCM patients,even without LGE of hypertrophied apical segments.Conclusions:LGE was frequently observed not only in the thickened apex of the heart but also in other LV segments,irrespective of the presence or absence of hypertrophy.The simple presence of LGE on CMR was not representative of adverse prognosis in this population.
文摘In this article, the industrial process of CO_2 capture using monoethanolamine as an aqueous solvent was probed carefully from the mass transfer viewpoint. The simulation of this process was done using Rate-Base model, based on two-film theory. The results were validated against real plant data. Compared to the operational unit, the error of calculating absorption percentage and CO_2 loading was estimated around 2%. The liquid temperature profiles calculated by the model agree well with the real temperature along the absorption tower, emphasizing the accuracy of this model. Operational sensitivity analysis of absorption tower was also done with the aim of determining sensitive parameters for the optimized design of absorption tower and optimized operational conditions. Hence,the sensitivity analysis was done for the flow rate of gas, the flow rate of solvent, flue gas temperature, inlet solvent temperature, CO_2 concentration in the flue gas, loading of inlet solvent, and MEA concentration in the solvent. CO_2 absorption percentage, the profile of loading, liquid temperature profile and finally profile of CO_2 mole fraction in gas phase along the absorption tower were studied. To elaborate mass transfer phenomena, enhancement factor, interfacial area, molar flux and liquid hold up were probed. The results show that regarding the CO_2 absorption, the most important parameter was the gas flow rate. Comparing liquid temperature profiles showed that the most important parameter affecting the temperature of the rich solvent was MEA concentration.
文摘AIM:To compare the imaging results with histology and to evaluate the diagnostic sensitivity of imaging modalities for hepatocellular carcinoma(HCC)smaller than 2 cm.METHODS:Nodules smaller than 2 cm(n=34)revealed by ultrasonography(US)in 29 patients with liver cirrhosis were analyzed.Histological diagnosis of HCC was performed by ultrasonographic guidance:moderately-differentiated HCC(n=24);well-differentiated HCC(n=10).The patterns disclosed by the four imaging modalities defined the conclusive diagnosis of HCC:(1)contrast-enhanced computed tomography(CECT),hypervascularity in the arterial phase and washout in the equilibrium phase;(2)Sonazoid contrast-enhanced US(CEUS),hypervascularity in the early vascular phase and defect in the Kupffer phase;(3)gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid(Gd-EOBDTPA)-enhanced magnetic resonance imaging(MRI),hypervascularity in the arterial phase and/or defect in the hepatobiliary phase;and(4)CT arterioportal angiography:hypervascularity by CT during arteriography and/ or perfusion defect by CT during arterial portography.RESULTS:Overall,the sensitivity of diagnosing HCC smaller than 2 cm was 52.9%(18/34)(95%CI:35.170.2)by CECT;67.6%(23/34)(95%CI:49.5-82.6)by Sonazoid CEUS;76.5%(26/34)(95%CI:58.8-89.3) by Gd-EOB-DTPA MRI;and 88.2%(30/34)(95%CI: 72.5-96.7)by CT arterioportal angiography.The diagnostic sensitivity of detecting moderately-differentiated HCC by CECT,Sonazoid CEUS,Gd-EOB-DTPA MRI and CT arterioportal angiography was 62.5%(15/24)(95%CI: 40.6-81.2),79.2%(19/24)(95%CI:57.8-92.9),75.0% (18/24)(95%CI:53.3-90.2)and 95.8%(23/24)(95% CI:78.9-99.9),respectively.A significant difference(P< 0.05)was observed between CECT and CT arterioportal angiography in all nodules.There was no difference between Sonazoid CEUS,Gd-EOB-DTPA MRI,and CT arterioportal angiography.The combined sensitivity of Sonazoid CEUS and Gd-EOB-DTPA MRI was 94.1%(32/34).CONCLUSION:Changing the main diagnostic modality for HCC smaller than 2 cm from CT arterioportal angiography to Sonazoid CEUS and Gd-EOB-DTPA MRI is recommended.
基金supported by the Guangdong Province Key Field R&D Program Project(2020B0101110002)National Key R&D Program of China(2021YFB2800804)the National Natural Science Foundation of China(61905095,62101214).
文摘An exceptional-point(EP)enhanced fiber-optic bending sensor is reported.The sensor is implemented based on paritytime(PT)-symmetry using two coupled Fabry-Perot(FP)resonators consisting of three cascaded fiber Bragg gratings(FBGs)inscribed in an erbium-ytterbium co-doped fiber(EYDF).The EP is achieved by controlling the pumping power to manipulate the gain and loss of the gain and loss FP resonators.Once a bending force is applied to the gain FP resonator to make the operation of the system away from its EP,frequency splitting occurs,and the frequency spacing is a nonlinear function of the bending curvature,with an increased slope near the EP.Thus,by measuring the frequency spacing,the bending information is measured with increased sensitivity.To achieve high-speed and high-resolution interrogation,the optical spectral response of the sensor is converted to the microwave domain by implementing a dual-passband microwave-photonic filter(MPF),with the spacing between the two passbands equal to that of the frequency splitting.The proposed sensor is evaluated experimentally.A curvature sensing range from 0.28 to 2.74 m^(−1) is achieved with an accuracy of 7.56×10^(−4 )m^(−1 )and a sensitivity of 1.32 GHz/m^(−1),which is more than 4 times higher than those reported previously.
文摘目的:探讨3.0T磁共振流动敏感黑血序列三维T_(1)加权增强扫描(FSBB 3D CE-T_(1)WI)在脑转移瘤中的应用价值。方法:回顾性将2021年1月-2022年8月在本院就诊且经临床和影像检查证实的52例脑转移患者纳入研究。所有患者分别行颅脑FSBB 3D CE-T_(1)WI、FSE CE-T_(1)WI和快速梯度回波序列三维T_(1)加权对比增强(FFE 3D CE-T_(1)WI)扫描,采用卡方检验或Fisher精确概率检验比较3个序列之间病灶检出率的差异。结果:经随访证实颅内转移灶总数为371个,FSBB 3D CE-T_(1)WI的检出率99.73%(370/371),FFE 3D CE-T_(1)WI的检出率为83.02%(308/371),FSE CE-T_(1)WI的检出率为78.44%(291/371),三者之间检出率的差异有统计学意义(χ^(2)=82.748,P<0.05)。分层分析:直径<3 mm的转移灶共160个,FSE CE-T_(1)WI、FFE 3D CE-T_(1)WI和FSBB 3D CE-T_(1)WI的检出率分别为50.62%、60.62%和99.37%,三个序列之间检出率的差异有统计学意义(χ^(2)=101.436,P<0.05);对于直径3~10 mm的转移灶,FSE CE-T_(1)WI、FFE 3D CE-T_(1)WI和FSBB 3D CE-T_(1)WI的检出率分别为99.38%、100%和100%,三个序列之间检出率的差异无统计学意义(P>0.05);对直径>10 mm的转移灶,三个序列的检出率均为100%,差异无统计学意义(P>0.05)。结论:FSBB 3D CE-T_(1)WI在检出脑转移瘤方面要优于常规和高分辨序列MR增强扫描,值得临床推广。
基金National Natural Science Foundation of China(NSFC)(11774286,11374238,11534008,11574247)
文摘We investigate the sensitivity of the angular rotation measurement with the method of homodyne detection in SU(2) and SU(1,1) interferometers by employing orbital angular momentum(OAM). By combining a coherent beam with a vacuum beam in an SU(2) interferometer, we get the sensitivity of the angular rotation measurement as 1/(2N^(1/2)l). We can surpass the limit of the angular rotation measurement in an SU(1,1) interferometer by combining a coherent beam with a vacuum beam or a squeezed vacuum beam when the probe beam has OAM. Without injection, the sensitivity can reach 1/(2N^(1/2)l). In addition, by employing another construction of an SU(1,1) interferometer where the pump beam has OAM, with the same injection of an SU(1,1) interferometer, the sensitivity of the angular rotation measurement can be improved by a factor of 2, reaching 1/(4Nl). The results confirm the potential of this technology for precision measurements in angular rotation measurements.
基金supported by the Provincial Key Clinical Specialty(Medical Imaging)Development Program from Health and Family Planning Commission of Hunan Province,China(No.2015/43)the Health and Family Planning Commission of Hunan Province,China(No.B2016060)the National Key Clinical Specialty(Oncology Department)Development Program from National Health and Family Planning Commission of China(No.2013/544)
文摘Preoperative detection of lymph nodes（LNs） metastasis is always highly challenging for radiologists nowadays. The utility of quantitative dynamic contrast-enhanced magnetic resonance imaging（QDCE-MRI） in identifying LNs metastasis is not well understood. In the present study, 59 patients with histologically proven rectal carcinoma underwent preoperative QDCE-MRI. The short axis diameter ratio, long axis diameter ratio, short-to-long axis diameter ratio and QDEC-MRI parameters（Ktrans, Kep, fPV and Ve） values were compared between the non-metastatic（n=44） and metastatic（n=35） LNs groups based on pathological examination. Compared with the non-metastatic group, the metastatic group exhibited significantly higher short axis diameter（7.558±0.668 mm vs. 5.427±0.285 mm）, Ktrans（0.483±0.198 min-1 vs. 0.218±0.116 min^-1） and Ve（0.399±0.118 vs. 0.203±0.096） values（all P〈0.05）. The short-to-long axis diameter ratio, long axis diameter ratio, Kep and fPV values did not show significant differences between the two groups. In conclusion, our results showed that for LNs larger than 5 mm in rectal cancer, there are distinctive differences in the Ktrans and Ve values between the metastatic and non-metastatic LNs, suggesting that QDCE-MRI may be potentially helpful in identifying LNs status.
基金Supported by Grants from the Japan Society for the Promotion of Science and the Japanese Foundation for the Research and Promotion of Endoscopy,No.22590764 and No.25461035
文摘AIM: To assess the usefulness of contrast-enhanced harmonic endoscopic ultrasonography(CH-EUS) for lymph node metastasis in pancreatobiliary carcinoma.METHODS: All patients suspected of pancreatobiliary carcinoma with visible lymph nodes after standard EUS between June, 2009 and January, 2012 were enrolled.In the primary analysis, patients with successful EUSfine needle aspiration(FNA) were included. The lymph nodes were assessed by several standard EUS variables(short and long axis lengths, shape, edge characteristic and echogenicity), color Doppler EUS variable [central intranodal blood vessel(CIV) presence] and CH-EUS variable(heterogeneous/homogeneous enhancement patterns). The diagnostic accuracy relative to EUSFNA was calculated. In the second analysis, N-stage diagnostic accuracy of CH-EUS was compared with EUS-FNA in patients who underwent surgical resection.RESULTS: One hundred and nine patients(143 lymph nodes) fulfilled the criteria. The short axis cutoff ≥ 13 mm predicted malignancy with a sensitivity and specificity of 72% and 85%, respectively. These values were 72% and 63% for the long axis cut-off ≥ 20 mm, 62% and 75% for the round shape variable, 81% and 30% for the sharp edge variable, 66% and 61% for the hypoechogenicity variable, 70% and 72% for the CIV-absent variable, and 83% and 91% for the heterogeneous CH-EUS-enhancement variable, respectively. CH-EUS was more accurate than standard and color Doppler EUS, except the short axis cut-off. Notably, three patients excluded because of EUS-FNA failure were correctly N-staged by CH-EUS.CONCLUSION: CH-EUS complements standard and color Doppler EUS and EUS-FNA for assessment of lymph node metastases.
基金supported by the(Grant no.P108/12/G108)Tomsk Polytechnic University(Grant no.VIU-RSCABS-196/2018)the European Structural and Investment Funds,OP RDE-funded project“ChemJets”(Grant no.CZ.02.2.69/0.0/0.0/16_027/0008351).
文摘The optical fibers,coated with plasmonic active metal films,represent the simple and unpretentious sensors,potentially useful for measurements of physical or chemical quantities and wide range of analytical application.All fiber-based plasmonic sensors operate on the same physical principle based on changes in the position of the plasmon absorption peak induced by a variation of surrounding medium refractive index.However,the observed spectral differences are often weak,and thus an enhancement of sensor sensitivity is strongly required.In this paper,we propose the immobilization of gold nanoparticles with sharp edges on the thin gold layer,deposited on the multimode fiber surface for improvement of the sensor functionality.The morphological and compositional changes in the gold covered fiber surface were determined by using the atomic force microscopy,scanning electron microscopy,and energy-dispersive X-ray spectroscopy methods.As a result of gold nanoparticles immobilization,the pronounced plasmon energy concentration near the fiber surface occurred,thus enhancing the response of the proposed hybrid plasmonic system to the variation of ambient refractive index.The position of plasmon absorption in the case of the created plasmonic structure was shown to be more sensitive to the changes in the surrounding medium in comparison with the standard sensors based on the bare gold layer.
