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Venous Doppler flow patterns,venous congestion,heart disease and renal dysfunction:A complex liaison 被引量:1
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作者 Alessio Di Maria Rossella Siligato +1 位作者 Marta Bondanelli Fabio Fabbian 《World Journal of Cardiology》 2024年第1期5-9,共5页
The World Journal of Cardiology published an article written by Kuwahara et al that we take the pleasure to comment on.We focused our attention on venous congestion.In intensive care settings,it is now widely accepted... The World Journal of Cardiology published an article written by Kuwahara et al that we take the pleasure to comment on.We focused our attention on venous congestion.In intensive care settings,it is now widely accepted that venous congestion is an important clinical feature worthy of investigation.Evaluating venous Doppler profile abnormalities at multiple sites could suggest adequate treatment and monitor its efficacy.Renal dysfunction could trigger or worsen fluid overload in heart disease,and cardio-renal syndrome is a well-characterized spectrum of disorders describing the complex interactions between heart and kidney diseases.Fluid overload and venous congestion,including renal venous hypertension,are major determinants of acute and chronic renal dysfunction arising in heart disease.Organ congestion from venous hypertension could be involved in the development of organ injury in several clinical situations,such as critical diseases,congestive heart failure,and chronic kidney disease.Ultrasonography and abnormal Doppler flow patterns diagnose clinically significant systemic venous congestion.Cardiologists and nephrologists might use this valuable,noninvasive,bedside diagnostic tool to establish fluid status and guide clinical choices. 展开更多
关键词 Cardio-renal syndrome Fluid overload Venous congestion Acute kidney injury ULTRASOUND doppler flow patterns
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Clinical Versus Doppler Based Assessment in Determining Amputation Level in Diabetic Foot Gangrene;A Prospective Cross-Sectional Study at Atbuth, Bauchi
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作者 Shaphat Shuaibu Ibrahim Stephen Yusuf +4 位作者 Abubakar Musa Shirama Yakubu Bababa Yusuf Aliyu Salihu Makama Baje Salihu Bukar Shehu 《Open Journal of Orthopedics》 2024年第8期366-373,共8页
Background: Amputation is defined as the surgical removal of a limb or part of a limb through the bone. If the amputation is done above or below the knee, they are termed major while minor amputations involve the part... Background: Amputation is defined as the surgical removal of a limb or part of a limb through the bone. If the amputation is done above or below the knee, they are termed major while minor amputations involve the partial removal of foot including forefoot resections, ray amputation of the digits or parts of the digits. Significant number of patients with diabetic foot ulcers end with amputations. In the past the amputation level was decided by clinical assessment alone, such as physical examination using color, temperature, peripheral pulses and wound bleeding during surgical procedure. The use of Doppler ultrasound to measure arterial blood pressure at the proposed amputation site has been advocated as a predictor of amputation success. An optimal choice of the level of amputation can reduce amputation complications. Methodology: A Prospective comparative randomized cross-sectional study carried out between 1st January 2022 and 1st January 2024 in ATBUTH, Bauchi amongst patients with diabetic foot Wagener stage IV and V scheduled for amputation. Outcome measures of wound break down, flap necrosis and re-amputation were assessed amongst the clinical based level assessment group and the doppler based level assessment group. Results: A total of 171 patients were recruited into the study. Males 103 and 68 are females, giving a male to female ratio of 1.5:1. mean age 47 years. There were 84 patients in the clinical based level assessment group and 87 patients in the doppler based level assessment. Conclusion: Diabetes mellitus foot disease is a significant risk factor for non-traumatic lower limb amputation and doppler level assessment is superior to clinical level in determining amputation level among diabetic patients scheduled for amputation. P-value 0.003. 展开更多
关键词 DIABETICS AMPUTATION Foot Gangrene doppler CLINICAL
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Remote sensing of air pollution incorporating integrated-path differential-absorption and coherent-Doppler lidar
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作者 Ze-hou Yang Yong Chen +5 位作者 Chun-li Chen Yong-ke Zhang Ji-hui Dong Tao Peng Xiao-feng Li Ding-fu Zhou 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期594-601,共8页
An innovative complex lidar system deployed on an airborne rotorcraft platform for remote sensing of atmospheric pollution is proposed and demonstrated.The system incorporates integrated-path differential absorption l... An innovative complex lidar system deployed on an airborne rotorcraft platform for remote sensing of atmospheric pollution is proposed and demonstrated.The system incorporates integrated-path differential absorption lidar(DIAL) and coherent-doppler lidar(CDL) techniques using a dual tunable TEA CO_(2)laser in the 9—11 μm band and a 1.55 μm fiber laser.By combining the principles of differential absorption detection and pulsed coherent detection,the system enables agile and remote sensing of atmospheric pollution.Extensive static tests validate the system’s real-time detection capabilities,including the measurement of concentration-path-length product(CL),front distance,and path wind speed of air pollution plumes over long distances exceeding 4 km.Flight experiments is conducted with the helicopter.Scanning of the pollutant concentration and the wind field is carried out in an approximately 1 km slant range over scanning angle ranges from 45°to 65°,with a radial resolution of 30 m and10 s.The test results demonstrate the system’s ability to spatially map atmospheric pollution plumes and predict their motion and dispersion patterns,thereby ensuring the protection of public safety. 展开更多
关键词 Differential absorption LIDAR COHERENT doppler lidar Remoting sensing Atmospheric pollution
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Observation of Doppler shift f_(D) modulated by the internal kink mode using conventional reflectometry in the EAST tokamak
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作者 李恭顺 张涛 +18 位作者 耿康宁 文斐 叶凯萱 徐立清 朱翔 张学习 钟富彬 周振 杨书琪 周子强 喻琳 兰婷 王守信 提昂 张寿彪 刘海庆 李国强 高翔 the EAST Team 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第3期1-9,共9页
In this paper we present a new experimental observation using a conventional reflectometry technique,poloidal correlation reflectometry(PCR),in the Experimental Advanced Superconducting Tokamak(EAST).The turbulence sp... In this paper we present a new experimental observation using a conventional reflectometry technique,poloidal correlation reflectometry(PCR),in the Experimental Advanced Superconducting Tokamak(EAST).The turbulence spectrum detected by the PCR system exhibits an asymmetry and induced Doppler shift f_(D)during the internal kink mode(IKM)rotation phase.This Doppler shift f_(D)is the target measurement of Doppler reflectometry,but captured by conventional reflectometry.Results show that the Doppler shift f_(D)is modulated by the periodic changes in the effective angle between the probing wave and cutoff layer normal,but not by plasma turbulence.The fishbone mode and saturated long-lived mode are typical IKMs,and this modulation phenomenon is observed in both cases.Moreover,the value of the Doppler shift f_(D)is positively correlated with the amplitude of the IKM,even when the latter is small.However,the positive and negative frequency components of the Doppler shift f_(D)can be asymmetric,which is related to the plasma configuration.A simulated analysis is performed by ray tracing to verify these observations.These results establish a clear link between f_(D)and IKM rotation,and are helpful for studying the characteristics of IKM and related physical phenomena. 展开更多
关键词 microwave reflectometry doppler shift internal kink mode
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Comparison and Verification of Coherent Doppler Wind Lidar and Radiosonde Data in the Beijing Urban Area
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作者 Zexu LUO Xiaoquan SONG +4 位作者 Jiaping YIN Zhichao BU Yubao CHEN Yongtao YU Zhenlu ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第11期2203-2214,共12页
As a new type of wind field detection equipment, coherent Doppler wind lidar(CDWL) still needs more relevant observation experiments to compare and verify whether it can achieve the accuracy and precision of tradition... As a new type of wind field detection equipment, coherent Doppler wind lidar(CDWL) still needs more relevant observation experiments to compare and verify whether it can achieve the accuracy and precision of traditional observation equipment in urban areas. In this experiment, a self-developed CDWL provided four months of observations in the southern Beijing area. After the data acquisition time and height match, the wind profile data obtained based on a Doppler beam swinging(DBS) five-beam inversion algorithm were compared with radiosonde data released from the same location. The standard deviation(SD) of wind speed is 0.8 m s^(–1), and the coefficient of determination R~2 is 0.95. The SD of the wind direction is 17.7° with an R~2 of 0.96. Below the height of the roughness sublayer(about 400 m), the error in wind speed and wind direction is significantly greater than the error above the height of the boundary layer(about 1500 m). For the case of wind speeds less than 4 m s^(–1), the error of wind direction is more significant and is affected by the distribution of surrounding buildings. Averaging at different height levels using suitable time windows can effectively reduce the effects of turbulence and thus reduce the error caused by the different measurement methods of the two devices. 展开更多
关键词 coherent doppler wind lidar RADIOSONDE wind measurement urban boundary layer
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Decoupling of temporal/spatial broadening effects in Doppler wind LiDAR by 2D spectral analysis
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作者 刘珍 张云鹏 +3 位作者 竹孝鹏 刘继桥 毕德仓 陈卫标 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期447-452,共6页
Pulse echo accumulation is commonly employed in coherent Doppler wind LiDAR(light detection and ranging)under the assumption of steady wind.Here,the measured spectral data are analyzed in the time dimension and freque... Pulse echo accumulation is commonly employed in coherent Doppler wind LiDAR(light detection and ranging)under the assumption of steady wind.Here,the measured spectral data are analyzed in the time dimension and frequency dimension to cope with the temporal wind shear and achieve the optimal accumulation time.A hardware-efficient algorithm combining the interpolation and cross-correlation is used to enhance the wind retrieval accuracy by reducing the frequency sampling interval and then reduce the spectral width calculation error.Moreover,the temporal broadening effect and spatial broadening effect are decoupled according to the strategy we developed. 展开更多
关键词 doppler wind LiDAR spectral analysis hardware efficiency spectrum broadening effects
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Abnormal Umbilical Doppler: Incidence and Neonatal Outcomes among Hypertensive Disorders in Pregnancy at KCMC: A Hospital-Based Prospective Cohort Study
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作者 Yusuph Mwidibo Pendo Mlay +11 位作者 Adnan Sadiq Gosbert George Bariki Mchome Nasra Batchu Glory Mangi Raziya Gaffur Rafiki Mjema Eusebius Maro Tom Kakumbi Doris Rwenyagila Gileard Masenga Patricia Swai 《Open Journal of Obstetrics and Gynecology》 2024年第8期1253-1266,共14页
Hypertensive disorders of pregnancy (HDP) are the most common maternal and perinatal health challenges. Globally, the incidence of HDP increased from 16.30 million to 18.08 million, with a total increase of about 10.9... Hypertensive disorders of pregnancy (HDP) are the most common maternal and perinatal health challenges. Globally, the incidence of HDP increased from 16.30 million to 18.08 million, with a total increase of about 10.9% from 1990 to 2019. Umbilical Doppler study in hypertensive disorders of pregnancy helps to predict neonatal outcomes and prevent neonatal and maternal morbidity and mortality. Objective: This study aims to determine the incidence of abnormal umbilical Doppler among hypertensive pregnant women, to identify the adverse neonatal outcomes associated with abnormal umbilical Doppler, and also to detect the diagnostic predictive values of umbilical Doppler to neonatal outcomes at KCMC. Material and methods: A hospital-based prospective cohort study included women with hypertensive disorders of pregnancy from the gestational age of 28 weeks and above, followed up to delivery during the study period from August 2022 to March 2023. Multivariate logistic regression analysis was used to determine the association between AUD and neonatal outcomes. Results: Out of 112 women with HDP, the incidence of abnormal umbilical Doppler was 38 (33.93%). Abnormal umbilical Doppler was associated with neonates with low birth weight aOR (95% of CI) of 4.52 (1.59 - 12.83) p = 0.005 and neonatal ICU admission 9.71 (2.90 - 32.43) p Conclusion: The incidence of abnormal umbilical Doppler is high in hypertensive disorders of pregnancy which is associated with an increase in neonatal low birth weight and neonatal ICU admissions, the sensitivity of abnormal umbilical Doppler in prediction of low birth weight and neonatal ICU admission is significant hence the routine use of umbilical Doppler assessment among hypertensive pregnant women is crucial. 展开更多
关键词 Hypertensive Disorders in Pregnancy Umbilical doppler Neonatal Outcomes KCMC
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Classification of birds and drones by exploiting periodical motions in Doppler spectrum series 被引量:1
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作者 DUAN Jia ZHANG Lei +3 位作者 WU Yifeng ZHANG Yue ZHAO Zeya GUO Xinrong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第1期19-27,共9页
With the rapidly growing abuse of drones, monitoring and classification of birds and drones have become a crucial safety issue. With similar low radar cross sections(RCSs), velocities, and heights, drones are usually ... With the rapidly growing abuse of drones, monitoring and classification of birds and drones have become a crucial safety issue. With similar low radar cross sections(RCSs), velocities, and heights, drones are usually difficult to be distinguished from birds in radar measurements. In this paper, we propose to exploit different periodical motions of birds and drones from highresolution Doppler spectrum sequences(DSSs) for classification.This paper presents an elaborate feature vector representing the periodic fluctuations of RCS and micro kinematics. Fed by the Doppler spectrum and feature sequence, the long to short-time memory(LSTM) is used to solve the time series classification.Different classification schemes to exploit the Doppler spectrum series are validated and compared by extensive real-data experiments, which confirms the effectiveness and superiorities of the proposed algorithm. 展开更多
关键词 target classification long-to-short memory(LSTM) drone discrimination doppler spectrum series
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Simultaneous measurement of velocity profile and liquid film thickness in horizontal gas–liquid slug flow by using ultrasonic Doppler method 被引量:1
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作者 Lusheng Zhai Bo Xu +1 位作者 Haiyan Xia Ningde Jin 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第6期323-340,共18页
Horizontal gas-liquid two-phase flows widely exist in chemical engineering,oil/gas production and other important industrial processes.Slug flow pattern is the main form of horizontal gas-liquid flows and characterize... Horizontal gas-liquid two-phase flows widely exist in chemical engineering,oil/gas production and other important industrial processes.Slug flow pattern is the main form of horizontal gas-liquid flows and characterized by intermittent motion of film region and slug region.This work aims to develop the ultrasonic Doppler method to realize the simultaneous measurement of the velocity profile and liquid film thickness of slug flow.A single-frequency single-channel transducer is adopted in the design of the field-programmable gate array based ultrasonic Doppler system.A multiple echo repetition technology is used to improve the temporal-spatial resolution for the velocity profile.An experiment of horizontal gas-liquid two-phase flow is implemented in an acrylic pipe with an inner diameter of 20 mm.Considering the aerated characteristics of the liquid slug,slug flow is divided into low-aerated slug flow,high-aerated slug flow and pseudo slug flow.The temporal-spatial velocity distributions of the three kinds of slug flows are reconstructed by using the ultrasonic velocity profile measurement.The evolution characteristics of the average velocity profile in slug flows are investigated.A novel method is proposed to derive the liquid film thickness based on the instantaneous velocity profile.The liquid film thickness can be effectively measured by detecting the position and the size of the bubbles nearly below the elongated gas bubble.Compared with the time of flight method,the film thickness measured by the Doppler system shows a higher accuracy as a bubble layer occurs in the film region.The effect of the gas distribution on the film thickness is uncovered in three kinds of slug flows. 展开更多
关键词 Gas–liquid flow Complex fluids Measurement Ultrasonic doppler Velocity profile Liquid film thickness
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Comparison of methods for turbulence Doppler frequency shift calculation in Doppler reflectometer
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作者 仲小明 邹晓岚 +16 位作者 周楚 刘阿娣 庄革 冯喜 张津 季佳旭 范泓锐 刘深 王士凡 高刘天 史文祥 兰涛 李弘 谢锦林 毛文哲 刘子奚 刘万东 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第9期42-50,共9页
The Doppler reflectometer(DR),a powerful diagnostic for the plasma perpendicular velocity(u⊥)and turbulence measurement,has been widely used in various fusion devices.Many efforts have been put into extracting the Do... The Doppler reflectometer(DR),a powerful diagnostic for the plasma perpendicular velocity(u⊥)and turbulence measurement,has been widely used in various fusion devices.Many efforts have been put into extracting the Doppler shift from the DR signal.There are several commonly used methods for Doppler shift extraction,such as the phase derivative,the center of gravity,and symmetric fitting(SFIT).However,the strong zero-order reflection component around 0 kHz may interfere with the calculation of the Doppler shift.To avoid the influence of the zerofrequency peak,the asymmetric fitting(AFIT)method was designed to calculate the Doppler shift.Nevertheless,the AFIT method may lead to an unacceptable error when the Doppler shift is relatively small compared to the half width at half maximum(HWHM).Therefore,an improved method,which can remove the zero-frequency peak and fit the remaining Doppler peak with a Gaussian function,is devised to extract the Doppler shift.This method can still work reliably whether the HWHM is larger than the Doppler shift or not. 展开更多
关键词 perpendicular velocity measurement doppler reflectometer doppler shift
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Color Doppler ultrasound imaging in varicoceles: Is the difference in venous diameter encountered during Valsalva predictive of palpable varicocele grade?
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作者 Kelly Lehner Catherine Ingram +7 位作者 Utsav Bansal Colleen Baca Adithya Balasubramanian Nannan Thirumavalavan Jason M.Scovell Saneal Rajanahally Matthew Pollard Larry I.Lipshultz 《Asian Journal of Urology》 CSCD 2023年第1期27-32,共6页
Objective:The clinical grading system for varicoceles is subjective and dependent on clinician experience.Color Doppler ultrasound(US)has not been standardized in the diagnosis of varicoceles.We aimed to determine if ... Objective:The clinical grading system for varicoceles is subjective and dependent on clinician experience.Color Doppler ultrasound(US)has not been standardized in the diagnosis of varicoceles.We aimed to determine if US measurement of varicocele could be predictive of World Health Organization(WHO)varicocele grade.Methods:Men who presented for either scrotal pain or infertility to a tertiary men’s health clinic underwent physical examination,and varicoceles were graded following WHO criteria(0Zsubclinical,1,2,3).US was used to measure largest venous diameter in the pampiniform plexus bilaterally at rest and during Valsalva maneuver.Receiver operator characteristic curve analysis was used to determine if resting diameter,diameter during Valsalva,or change in diameter between at rest and during Valsalva provided the highest sensitivity and specificity for determining clinical grade.Threshold values for diameter were determined from these receiver operator characteristic curves.Results:A total of 102 men(50 with clinical varicocele and 52 with subclinical varicocele)were included.Diameter at rest was the best ultrasonographic discriminator between subclinical and clinical varicoceles(area under the curve[AUC]Z0.67)with a diameter threshold of 3.0 mm(sensitivity 79%,specificity 42%).Diameter during Valsalva had the greatest AUC for determining clinical Grades 1 versus 2(AUCZ0.57)with diameter threshold of 5.7 mm(sensitivity 71%,specificity 33%).For differentiating between Grades 2 and 3,diameter at rest had the greatest AUC of 0.65 with a threshold of 3.6 mm(sensitivity 71%,specificity 58%).Conclusion:Our results corroborate other studies that have shown a weak correlation between US and clinical grading.The use of diameter during Valsalva was less predictive than diameter at rest and was only clinically significant in differentiating between Grade 1 and 2 varicocele.A standardized method for determining clinically relevant varicoceles on US would allow for improved patient counseling and clinical decision-making. 展开更多
关键词 VARICOCELE Ultrasound doppler Venous plexus INFERTILITY
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Investigation of phase modulation and propagation-route effect from unmatched large-scale structures for Doppler reflectometry measurement through 2D full-wave modeling
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作者 冯喜 刘阿娣 +20 位作者 周楚 邹晓岚 庄革 王守信 王明远 刘海庆 丁卫星 张寿彪 吴木泉 朱翔 郝保龙 张津 刘朝阳 季佳旭 仲小明 刘深 谢锦林 林晓东 黄建军 高翔 万元熙 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第11期55-65,共11页
To interpret the common symmetric peaks caused by the large-scale structure in the complex S(f)spectrum from the heterodyne Doppler reflectometry(DR)measurement in EAST,a 2D circular-shaped O-mode full-wave model base... To interpret the common symmetric peaks caused by the large-scale structure in the complex S(f)spectrum from the heterodyne Doppler reflectometry(DR)measurement in EAST,a 2D circular-shaped O-mode full-wave model based on the finite-difference time-domain method is built.The scattering characteristics and the influences on the DR signal from various scales are investigated.When the structure is located around the cutoff layer,a moving radial or poloidal large-scale structure k_(θ)k_(θ),match(k_(θ),match is the theoretic wavenumber of Bragg scattering)could both generate an oscillation phase term called‘phase modulation’,and symmetrical peaks in the complex S(f)spectrum.It was found that the image-rejection ratio A_(−1)/A_(+1)(A_(±1)represents the amplitudes of±1 order modulation peaks)could be a feasible indicator for experiment comparison.In the case when the structure is near the cutoff layer with the same arrangement as the experiment for the edge DR channel,the curve of A_(−1)/A_(+1)versus kθcan be divided into three regions,weak asymmetrical range with k_(θ)/k_(0)0.15(k_(0)is the vacuum wavenumber),harmonics range with 0.15k_(θ)/k_(0)0.4,and Bragg scattering range of 0.4k_(θ)/k_(0)0.7.In the case when the structure is located away from the cutoff layer,the final complex S(f)spectrum is the simple superimposing of modulation and Bragg scattering,and the modulation peaks have an amplitude response nearly proportional to the local density fluctuation,called the‘propagationroute effect’.Under the H-mode experiment arrangement for the core DR,a critical fluctuation amplitude Amp(n_(e,Mod.@route))/Amp(n_(e,Tur.@MSA)∼1.3–4.1(Amp(n_(e,Mod.@route))refers to the pedestal large-scale structure amplitude and Amp(ne,Tur.@MSA)refers to turbulence amplitude at the main scattering area)is needed for the structure in the pedestal to be observed by the core DR measurement.The simulations are well consistent with the experimental results.These effects need to be carefully considered during the DR signal analyses as the injecting beam passes through the plasma region with large-scale structures. 展开更多
关键词 doppler reflectometry full-wave simulation propagation-route effect
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A new model for Doppler shift of C-band echoes backscattered from sea surface
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作者 Jianbo Cui Yunhua Wang +4 位作者 Yanmin Zhang Huimin Li Wenzheng Jiang Yushi Zhang Xin Li 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第6期100-111,共12页
Within the framework of the two-scale scattering model,the Doppler shift of C-band radar return signals from the nonlinear sea surface are numerically evaluated.As an analytical approximation method,the Bragg resonanc... Within the framework of the two-scale scattering model,the Doppler shift of C-band radar return signals from the nonlinear sea surface are numerically evaluated.As an analytical approximation method,the Bragg resonance scattering method cannot accurately describe the backscattering field from sea surface.Therefore,in the twoscale scattering model,more accurate scattering coefficient(the normalized radar cross section,NRCS)evaluated by the C-band dual-polarized(HH/VV)empirical geophysical model function(CSAR model)is employed to replace the traditional Bragg NRCS to weight the Doppler shift.The numerical results indicate that there are obvious differences between the Doppler shift weighted by the CSAR NRCS and that weighted by the traditional Bragg NRCS.The hydrodynamic modulation of the large-scale waves is one of the important factors that affect the difference between the Doppler shift predicted in upwind and downwind directions.If the relaxation rate in the hydrodynamic modulation is set to be the angular frequency of the dominant water waves,the Doppler shift predicted by the numerical method can fit the results of the empirical model(C-band empirical geophysical model function,CDOP)well at moderate wind speed.Under low wind condition,the comparison shows that the empirical CDOP model appears to overestimate the Doppler shift.In order to facilitate the application,at the end of this paper a semi-empirical CSAR-DOP model,which is a polynomial fitting formula,is developed for evaluating the Doppler shift of C-band signals from time varying sea surface. 展开更多
关键词 doppler shift microwave scattering numerical simulation
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Predictive Value of Amniotic Fluid Index in Term Small for Gestational Age with Normal Doppler Studies for Perinatal Outcomes
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作者 Rajakarunage Madhuka Udantha Rajakaruna Samarathunga Madhava Gananatha Karunaratne Brahmanamudhiyanselage Nimesha Sajeewani Thennakoon 《Open Journal of Obstetrics and Gynecology》 2023年第8期1339-1349,共11页
Background and Aim: Delivery of a fetus with SGA is associated with increased risk of perinatal morbidity and mortality. Evidence is limited for the accuracy of Oligohydramnios to predict substantive perinatal morbidi... Background and Aim: Delivery of a fetus with SGA is associated with increased risk of perinatal morbidity and mortality. Evidence is limited for the accuracy of Oligohydramnios to predict substantive perinatal morbidity and mortality in non–anomalous SGA fetuses monitored with normal Doppler studies. The aim of this study is to determine the association between amniotic fluid index and adverse perinatal outcomes in term SGA fetuses with normal Doppler studies. Method: This is a prospective observational study carried out by 340 pregnant women who were admitted to obstetrics unit, Sri Jayewardenepura from January 2019 to January 2023. Singleton pregnancies at term who were diagnosed with SGA (EFW 10<sup>th</sup> centile or AC 10<sup>th</sup> centile) with normal umbilical artery and middle cerebral artery Doppler studies were included. AFI was assessed predelivery and data were collected according to demographic details, mode of delivery, time of delivery, intrapartum events, and neonatal outcomes. Results: A total of 340 term pregnant women were studied. Out of them, 44% were in AFI more than 10 groups and 37% and 19% were in AFI 5 - 10 and less than 5 groups respectively. More obstetrics interventions were reported in AFI 5 groupa in terms of induction of labor (P 0.04) and emergency caesarean sections (P 0.003). No significant deference in immediate neonatal outcome was detected between each group. (Meconium-stained liquor (P 0.634), 1 minute APGAR (P 0.575) and 5-minute APGAR P 0.165)). Neonatal unit admission (P 0.001) and long-term neonatal complications were <span style="font-family:Verdana;. 展开更多
关键词 Term SGA AFI doppler Perinatal Outcomes
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Theoretical analysis of the optical rotational Doppler effect under atmospheric turbulence by mode decomposition
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作者 马圣杰 徐世龙 +3 位作者 董骁 张鑫源 陈友龙 胡以华 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第10期459-467,共9页
The optical rotational Doppler effect associated with orbital angular momentum provides a new means for rotational velocity detection.In this paper,we investigate the influence of atmospheric turbulence on the rotatio... The optical rotational Doppler effect associated with orbital angular momentum provides a new means for rotational velocity detection.In this paper,we investigate the influence of atmospheric turbulence on the rotational Doppler effect.First,we deduce the generalized formula of the rotational Doppler shift in atmospheric turbulence by mode decomposition.It is found that the rotational Doppler signal frequency spectrum will be broadened,and the bandwidth is related to the turbulence intensity.In addition,as the propagation distance increases,the bandwidth also increases.And when C_(n)^(2)≤5×10^(-15)m^(-2/3)and 2z≤2 km,the rotational Doppler signal frequency spectrum width d and the spiral spectrum width d_(0)satisfy the relationship d=2d_(0-1).Finally,we analyze the influence of mode crosstalk on the rotational Doppler effect,and the results show that it destroys the symmetrical distribution of the rotational Doppler spectrum about 2l·Ω/2π.This theoretical model enables us to better understand the generation of the rotational Doppler frequency and may help us better analyze the influence of the complex atmospheric environment on the rotational Doppler frequency. 展开更多
关键词 optical rotational doppler effect atmospheric turbulence vortex beam mode decomposition mode crosstalk
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Investigation of lacrimal sac space-occupying lesions using color doppler ultrasound, computed tomography, and computed tomography dacryocystography
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作者 Zhen-Bin Qian Bo Yu +3 位作者 Ye Yang Wei Fang Jian-Li Dong Li-Qing Wei 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第8期1224-1230,共7页
AIM:To observe the imaging features of color Doppler ultrasound(CDU)and computed tomography(CT)or computed tomography dacryocystography(CT-DCG)in different types of lacrimal sac space-occupying lesions(SOLs).METHODS:T... AIM:To observe the imaging features of color Doppler ultrasound(CDU)and computed tomography(CT)or computed tomography dacryocystography(CT-DCG)in different types of lacrimal sac space-occupying lesions(SOLs).METHODS:This retrospective case series study included 21 patients with lacrimal sac SOLs who underwent lacrimal sac surgery between January 2018 and March 2022.The imaging features of CDU and CT or CT-DCG in these patients were extracted from the examination cloud system.The images were observed and analyzed.RESULTS:The detection rate of lacrimal SOLs between CDU(21/21,100%)and CT or CT-DCG(20/21,95.2%)had no statistically significant difference(P=1.0).CDU could detect the blood flow signals in all SOLs except mucocele and mucopeptide concretion.Among them,polyps had characteristic imaging changes on CDU and CT-DCG.The mucoceles and mucopeptide concretions had characteristic imaging changes on CDU,which could provide more information for differential diagnosis.CONCLUSION:The morphology and internal blood flow signals of lacrimal sac SOLs can be observed using CDU.CT or CT-DCG has advantages in observing structural damage around the lacrimal sac mass.Therefore,CDU may be used as a routine examination to exclude lacrimal sac SOLs before dacryocystorhinostomy in the absence of preoperative CT or CT-DCG. 展开更多
关键词 lacrimal sac computed tomography computed tomography dacryocystography color doppler ultrasound space-occupying lesions
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Metformin effect on internal carotid artery blood flow assessed by area under the curve of carotid artery Doppler in women with polycystic ovarian syndrome
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作者 Wisam Akram Wassan Nori Muna Abdul Ghani Zghair 《World Journal of Clinical Cases》 SCIE 2023年第6期1318-1329,共12页
BACKGROUND Insulin resistance(IR)was reported in most polycystic ovarian syndrome(PCOS)cases.Metformin,a biguanide drug,successfully reduced IR.Homeostatic Model Assessment for IR(HOMA-IR)and Doppler parameters assess... BACKGROUND Insulin resistance(IR)was reported in most polycystic ovarian syndrome(PCOS)cases.Metformin,a biguanide drug,successfully reduced IR.Homeostatic Model Assessment for IR(HOMA-IR)and Doppler parameters assessed metformin's effectiveness.AIM To verify whether the area under the curve of the internal carotid artery(AUC-ICA)Doppler wave can be a useful marker for assessing IR among PCOS cases who presented with menstrual irregularity and were treated with metformin over 6 mo.METHODS An observational,cross-sectional study recruited 54 eligible PCOS women;the anthropometrics were as follows:age,body mass index(BMI),menstrual cycle days,biochemical serum cholesterol,low and high-density lipoprotein,sex hormone-binding globulin,fasting blood glucose,and HOMA-IR,hormonal testosterone,luteinizing hormone over follicle-stimulating hormone ratio,and ultrasonic pulsatility index(PI)and resistance index(RI),carotid artery intima-media thickness(CIMT)and(AUC-ICA)parameters were initially recorded and repeated 3 mo and 6 mo later with metformin tab 500 mg;three times/day for 6 mo.In addition,AUC-ICA was assessed by taking repeated systolic and diastolic wave height measurements.RESULTS Metformin caused a progressive reduction in BMI,menstrual cycle days,biochemical hormonal,and Doppler parameters(CIMT,PI,RI,and AUC-ICA).AUC-ICA correlated strongly to all PCOS parameters.AUC-ICA correlated inversely with treatment time(r=-0.98,P<0.001)and positively with HOMA-IR(r=0.98,P<0.0001).Via the best subset regression model,the AUC-ICA had the highest predictive value for HOMA-IR.CONCLUSION AUC-ICA preceded PI,RI,and CIMT with a strong,meaningful correlation to all PCOS parameters,making it a reliable marker for the assessment of IR,especially during metformin therapy.Further studies are recommended to promote the application in practice. 展开更多
关键词 Carotid artery intima-media thickness Insulin resistance Internal carotid artery doppler METFORMIN Polycystic ovarian syndrome
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Doppler Radar Fault Judgment System and Remote Monitoring Platform
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作者 Yi ZHANG Xuejiao YAN 《Meteorological and Environmental Research》 CAS 2023年第4期32-33,共2页
The Doppler weather radar fault judging system and remote monitoring platform were introduced.Through the real-time scanning of radar alarm information coding,the platform can realize dynamic monitoring and real-time ... The Doppler weather radar fault judging system and remote monitoring platform were introduced.Through the real-time scanning of radar alarm information coding,the platform can realize dynamic monitoring and real-time alarm of Doppler radar equipment components,so as to improve the reliability of equipment operation,and truly realize"unattended"remote monitoring. 展开更多
关键词 doppler radar Alarm information Remote monitoring
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Ultrafast power Doppler imaging for ischemic encephalopathy:A case report
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作者 Li-Jie Huang Jian-Feng Jiao +2 位作者 Qiong He Jian-Wen Luo Yi Guo 《World Journal of Clinical Cases》 SCIE 2023年第31期7640-7646,共7页
BACKGROUND Severely elevated intracranial pressure due to various reasons,such as decreased cerebral perfusion,can lead to devastating neurological outcomes,such as brain herniation.Decompression craniectomy is a life... BACKGROUND Severely elevated intracranial pressure due to various reasons,such as decreased cerebral perfusion,can lead to devastating neurological outcomes,such as brain herniation.Decompression craniectomy is a life-saving procedure that is commonly performed for such a critical situation,but the changes in cerebral microvessels after brain herniation and decompression are unclear.Ultrafast power Doppler imaging(uPDI)is a new microvascular imaging technology that utilizes high frame rate plane/diverging wave transmission and advanced clutter filters.uPDI significantly improves Doppler sensitivity and can detect microvessels,which are usually invisible using traditional ultrasound Doppler imaging.CASE SUMMARY In this report,uPDI was used for the first time to observe the brain blood flow of a hypoperfusion area in a 4-year-old girl who underwent decompression craniectomy due to refractory intracranial hypertension(ICP)after malignant brain tumor surgery.B-mode imaging was used to verify the increased densities of the cerebral cortex and basal ganglia that were observed by computed tomography.CONCLUSION uPDI showed the local blood supplies and anatomical structures of the patient after decompressive craniectomy.uPDI is potentially a more intuitive and noninvasive method for evaluating the effects of severe ICP on cerebral microvessels. 展开更多
关键词 Decompression craniectomy Ultrafast power doppler imaging Cortical layer necrosis Luxury perfusion Case report
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Can the change of vasomotor activity in irritable bowel syndrome patients be detected via color Doppler ultrasound?
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作者 Omer Kazci Fahrettin Ege +2 位作者 Huseyin Aydemir Saliha Kazci Sonay Aydin 《World Journal of Radiology》 2023年第7期226-233,共8页
BACKGROUND Irritable bowel syndrome(IBS)is one of the most frequently referred conditions to the gastrointestinal outpatient clinic.The pathophysiology of IBS has not been determined with certainty.Visceral hypersensi... BACKGROUND Irritable bowel syndrome(IBS)is one of the most frequently referred conditions to the gastrointestinal outpatient clinic.The pathophysiology of IBS has not been determined with certainty.Visceral hypersensitivity is indicated as one of the pathophysiologies.The sympathetic nervous system is primarily in charge of controlling the arteries,and its effect is vasospasm in the medium and large arteries,resulting in decreased blood flow.AIM To demonstrate,using Doppler evaluation of the brachial artery,that sympathetic activity impairs vasomotor performance due to autonomic neuropathy,which we believe is associated with IBS.METHODS There were 58 participants in the study.The control group consisted of 29 healthy patients,while the remaining 29 patients had been diagnosed with IBS.Patients who met the Rome IV criteria and had IBS were included in the study.People with known polyneuropathy or non-IBS chronic conditions that can progress were excluded from the trial,as were those with essential hypertension,diabetes mellitus,cardiovascular disease,or peripheral arterial disease,and patients diagnosed with anxiety or depression.Those with moderate to severe carpal tunnel syndrome or a median nerve lesion due to trauma were also excluded from the trial.A Doppler probe was used to measure the baseline diameter and flow rates of the brachial artery from 2 cm superior to the antecubital fossa.The Doppler probe remained stationary throughout the experiment,allowing for continuous measurements.Then,to activate the sympathetic fibers,an electrical stimulus for 5 s with an intensity of 10 mA and a frequency of 1 Hz was applied to the median nerve at the wrist level via the bipolar stimulus electrode.The artery diameter and flow rates were measured again immediately following the fifth stimulus.RESULTS In healthy persons with no history of chronic illness,there was a statistically significant decrease in flow rate after stimulation(P<0.001).In addition,stimulation resulted in a statistically significant reduction in the diameter of the brachial artery(P<0.001).Patients diagnosed with IBS had statistically significant vasodilation and an increase in flow rate.CONCLUSION Sympathetic stimulation causes a reduction in vascular diameter and blood flow,whereas it has the reverse effect on IBS patients.In investigating the involvement of autonomic neuropathy in the development of IBS,significant changes in brachial artery Doppler parameters were observed before and after stimulation of the median nerve with low-current sensory stimulation.This method is thought to be more user-friendly and comfortable than other methods described in the literature. 展开更多
关键词 Irritable bowel syndrome doppler ultrasonography Brachial artery Median nerve Peripheral neuropathy Autonomic neuropathy
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