The purpose is to evaluate the feasibility of imaging mouse brain with high resolution ultrasound (HiRes US), and generation of mouse brain tumor (glioma) model under HiRes US guided implantation of glioma cells. Norm...The purpose is to evaluate the feasibility of imaging mouse brain with high resolution ultrasound (HiRes US), and generation of mouse brain tumor (glioma) model under HiRes US guided implantation of glioma cells. Normal mouse brain was imaged with 30 MHz HiRes US in six pups and ten adult nude mice. Glioma model was developed by injecting human glioma cells (5 × 105), U-87MG-luc, under HiRes US guidance, in three pups and five adult mice. Bioluminescence imaging, magnetic resonance imaging, and HiRes US were used for in vivo tumor imaging. In addition, brain imaging ex vivo with HiRes US were also performed in three tumor bearing and five normal brains. The brain parenchyma was seen as a homogeneous low echo on HiRes US without locoregional echo differences. An inverted U shaped linear echo structure (fissure) differentiated the telencephalon from the diencephalon. Bilaterally budding structure at the base of the skull represented the trigeminal nerve. The inserted needle, used to implant the glioma cells, was seen as a high linear echogenic reflection. Brain tumor on ex vivo HiRes US was well demarcated, homogeneous and hyperechoic compared to the surrounding healthy brain. In conclusion, imaging the brain with HiRes US in small animal model like mouse is possible and convenient. Real-time guiding is possible to perform any intervention from tumor implantation to percutaneous therapeutic procedures. Ex vivo, HiRes US is extremely useful to study the detailed anatomical features.展开更多
High-resolution ultrasound (HRU) imaging is a useful tool to study hyaluronic acid (HA) filler injection in the face. It is noninvasive, quick, well-tolerated, and can provide in vivo and dynamic information. The form...High-resolution ultrasound (HRU) imaging is a useful tool to study hyaluronic acid (HA) filler injection in the face. It is noninvasive, quick, well-tolerated, and can provide in vivo and dynamic information. The formations of pools or pearls in HA fillers could be observed real time during injection. The plane of injection could be determined accurately, and there were no specimen manipulation artifacts. It was observed that HA gel fillers with differing production technologies showed distinct spread and distribution patterns in the periocular tissues on HRU examination. The authors used HRU to assess deep injections of CHAP-Hyaluronic Acid (CHAP-HA) fillers for midface lift. 10 patients who underwent bilateral midface deep injections using CHAP-HA filler were examined with HRU before and immediately after treatment, and in 2 weeks and one month later. The CHAP-HA appeared as hypoechoic densities within the preperiosteal plane in HRU. CHAP-HA adopted variable morphology within the tissue depending on individual tissue densities and the compliance of the tissues in the plane of injection. CHAP-HA was unidentifiable with surrounding tissue after one month in 13 of the 20 injection sites. HRU allows in vivo study of CHAP-HA injection behavior and could be a tool for further studies of HA-tissue reactions.展开更多
High angular resolution X-ray imaging is always useful in astrophysics and solar physics. In principle, it can be performed by using coded-mask imaging with a very long mask-detector distance. Previously, the diffract...High angular resolution X-ray imaging is always useful in astrophysics and solar physics. In principle, it can be performed by using coded-mask imaging with a very long mask-detector distance. Previously, the diffraction-interference effect was thought to degrade coded-mask imaging performance dramatically at the low energy end with its very long mask-detector distance. The diffraction-interference effect is described with numerical calculations, and the diffraction-interference cross correlation reconstruction method （DICC） is developed in order to overcome the imaging performance degradation. Based on the DICC, a super-high angular resolution principle （SHARP） for coded-mask X-ray imaging is proposed. The feasibility of coded mask imaging beyond the diffraction limit of a single pinhole is demonstrated with simulations. With the specification that the mask element size is 50 × 50 μm^2 and the mask-detector distance is 50 m, the achieved angular resolution is 0.32arcsec above about 10keV and 0.36arcsec at 1.24keV （λ = 1 nm）, where diffraction cannot be neglected. The on-axis source location accuracy is better than 0.02 arcsec. Potential applications for solar observations and wide-field X-ray monitors are also briefly discussed.展开更多
High-resolution atomic-beam laser spectroscopy has been performed to study Stark effect of Ba atom. Stark spectra have been observed at various electric fields for Ba highly excited states. The scalar polarizability o...High-resolution atomic-beam laser spectroscopy has been performed to study Stark effect of Ba atom. Stark spectra have been observed at various electric fields for Ba highly excited states. The scalar polarizability of the transition from 6s5d3D2 to 5d6p3F3 at 728.0 nm and the tensor polarizability of the 3F3 level have been determined for the first time, to be αs = -89.8 (12) kHz/(kV/cm)2 and αt = -133.7 (20) kHz/(kV/cm)2, respectively.展开更多
Silicon isotope analysis traditionally uses a standard-sample bracketing （SSB） method that relies upon greater instrument stability than can be consistently expected. The following proposed method reduces the level ...Silicon isotope analysis traditionally uses a standard-sample bracketing （SSB） method that relies upon greater instrument stability than can be consistently expected. The following proposed method reduces the level of instrumental stability required for the analysis process and provides a valid solution for high-precision and accurate studies of Si isotopic compositions. Rock samples were dissolved by using alkali fusion and acidification. Silicon isotopes were purified with an ion exchange resin. Interfering peaks for isotopes were separated by using a Nu Plasma 1700 multi-collector inductively coupled plasma mass spectrometry （MS） system in high-resolution mode （M/AM 〉 8000 RP）. Two magnesium isotopes （25Mg and 26Mg） and three silicon isotopes （28Si, 29Si, and 3;Si） were analyzed in the same data collection cycle. Mg isotopes were used as an internal standard to calibrate the mass discrimination effects in MS analysis of Si isotopes in combination with the SSB method in order to reduce the effects of MS interference and instrumental mass dis- crimination on the accuracy of measurements. The conventional SSB method without the Mg internal standard and the proposed SSB method with Mg calibration delivered consistent results within two standard deviations. When Mg was used as an internal standard for calibration, the analysis precision was better than 0.05 %0 amu.展开更多
High-resolution images of human brain are critical for monitoring the neurological conditions in a portable and safe manner.Sound speed mapping of brain tissues provides unique information for such a purpose.In additi...High-resolution images of human brain are critical for monitoring the neurological conditions in a portable and safe manner.Sound speed mapping of brain tissues provides unique information for such a purpose.In addition,it is particularly important for building digital human acoustic models,which form a reference for future ultrasound research.Conventional ultrasound modalities can hardly image the human brain at high spatial resolution inside the skull due to the strong impedance contrast between hard tissue and soft tissue.We carry out numerical experiments to demonstrate that the time-domain waveform inversion technique,originating from the geophysics community,is promising to deliver quantitative images of human brains within the skull at a sub-millimeter level by using ultra-sound signals.The successful implementation of such an approach to brain imaging requires the following items:signals of sub-megahertz frequencies transmitting across the inside of skull,an accurate numerical wave equation solver simulating the wave propagation,and well-designed inversion schemes to reconstruct the physical parameters of targeted model based on the optimization theory.Here we propose an innovative modality of multiscale deconvolutional waveform inversion that improves ultrasound imaging resolution,by evaluating the similarity between synthetic data and observed data through using limited length Wiener filter.We implement the proposed approach to iteratively update the parametric models of the human brain.The quantitative imaging method paves the way for building the accurate acoustic brain model to diagnose associated diseases,in a potentially more portable,more dynamic and safer way than magnetic resonance imaging and x-ray computed tomography.展开更多
A high angular resolution near-infrared image that shows the intensity of polarization for the GG Tau A binary system was obtained with the Subaru Telescope. The image shows a circumbinary disk scattering the light fr...A high angular resolution near-infrared image that shows the intensity of polarization for the GG Tau A binary system was obtained with the Subaru Telescope. The image shows a circumbinary disk scattering the light from the central binary. The azimuthal profile of the intensity of polarization for the circumbinary disk is roughly reproduced by a simple disk model with the Henyey-Greenstein phase function and the Rayleigh function, indicating there are small dust grains at the surface of the disk. Combined with a previous observation of the circumbinary disk, our image indicates that the gap structure in the circumbinary disk orbits counterclockwise, but material in the disk orbits clockwise. We propose that there is a shadow caused by material located between the central binary and the circumbinary disk. The separations and position angles of the stellar components of the binary in the past 20 yr are consistent with the binary orbit with a = 33.4 AU and e = 0.34.展开更多
The study was conducted to determine the role of radiological investigation in assessing the severity of COVID-19 pneumonia with the help of chest X-ray (CXR), high resolution computed tomography (HRCT), and ultrasoun...The study was conducted to determine the role of radiological investigation in assessing the severity of COVID-19 pneumonia with the help of chest X-ray (CXR), high resolution computed tomography (HRCT), and ultrasound. This was a retrospective study conducted on 105 COVID-19 patients with symptoms of fever, cough, dyspnea, loss of sense of smell and taste, body ache. Diagnostic tests PCR were positive for COVID-19 included from Medicare Cardiac and General Hospital and Jinnah Medical College Hospital Korangi (JMCH) from April to November 2020. Written informed consent was taken from all participants. This study was approved by ethical review committee, Jinnah Medical & Dental College. Real time-PCR (RT-PCR) was done for the confirmation. Radiological imaging including Chest X-ray, HRCT chest, and ultrasound was done to study the severity of symptoms. Sixty-five patients had mild to moderate symptoms with oxygen saturation between 96% - 98% and 30 patients with severe pneumonia had between saturation 50% - 55%. Patients with mild symptoms were followed up by chest X-ray showing mostly normal chest X-rays but single or patches of ground glass opacities (HRCT). HRCT of 10 patients with low oxygen saturation 50% were already done showing bilateral peripheral patchy consolidation predominantly involving mid and lower lobes. 3 patients presented with patchy lung opacities and ultrasound showing similar findings with pleural effusion and ascites. Radiological imaging, specially CT-Scan was highly significant for diagnosing COVID-19 and severity of infection even in patients with negative PCR. Chest X-ray and ultrasound were also found to be a very useful tool.展开更多
Aim: The aim of this study was to determine the effect of training on endothelium-dependent vasodilatation in patients with coronary artery disease (CAD) after revascularization and healthy young men. Background: Impa...Aim: The aim of this study was to determine the effect of training on endothelium-dependent vasodilatation in patients with coronary artery disease (CAD) after revascularization and healthy young men. Background: Impaired endothelial function has been observed in patients with CAD and those with CAD risk factors. Studies have shown that exercise can enhance endothelial function. Methods: This experimental cross-sectional study was conducted on patients with CAD (3 months after CABG and PCI) and students of medical school in 2011. Endothelium dependent dilation of the brachial artery was determined by using high-resolution vascular ultrasonography through flow-mediated vasodilatation (FMD) after induction of ischemia, and the data were analyzed using SPSS, dependent t-test and ANCOVA. Findings: The findings showed that at baseline, FMD was reduced in revascularized patients, when compared with healthy young men, after 8 weeks, and exercise training significantly improved FMD in patients underwent training group [from 4.31 ± 1.45 (SD)% to 6.15 ± 0.773 (SD)%, p p ed unchanged, and even after aerobic training, it did not significantly modify the brachial artery diameter in these groups. Conclusion: Our study demonstrates that endothelial dysfunction persisting in CAD patients after revascularization and aerobic training can improve endothelial function in different vascular beds in CAD patients and healthy young men. This may contribute to the benefit of regular exercise in preventing and restricting cardiovascular disease.展开更多
Minimally invasive forehead augmentation is becoming increasingly popular in Asia. However, treatment of the glabella is associated with injection-related complications. The safety of injections can be increased throu...Minimally invasive forehead augmentation is becoming increasingly popular in Asia. However, treatment of the glabella is associated with injection-related complications. The safety of injections can be increased through a thorough understanding of the anatomy and precise injection planes. The authors propose a 3-point injection technique for forehead augmentation in Asian patients that uses CHAP-hyaluronic acid (CHAP-HA) filler. The longevity of the filler was assessed using high-resolution ultrasound (HRU) imaging. Fifteen patients were examined using HRU before and immediately after treatment and at 1 month, 3 months, 6 months, and 12 months. As evident in HRU imaging, CHAP-HA remained visible within surrounding tissue for 6.4 ± 3.7 months. The mean Global Aesthetic Improvement Scale rating was 2.4 ± 0.5 immediately after treatment, 2.8 ± 0.3 at 1 month, 2.7 ± 0.5 at 3 months, 2.1 ± 0.6 at 6 months, and 1.5 ± 0.6 at 12 months. Minimal side effects were reported. The authors demonstrated that CHAP-HA filler may be an optimal candidate for forehead filler augmentation using a 3-point injection technique.展开更多
文摘The purpose is to evaluate the feasibility of imaging mouse brain with high resolution ultrasound (HiRes US), and generation of mouse brain tumor (glioma) model under HiRes US guided implantation of glioma cells. Normal mouse brain was imaged with 30 MHz HiRes US in six pups and ten adult nude mice. Glioma model was developed by injecting human glioma cells (5 × 105), U-87MG-luc, under HiRes US guidance, in three pups and five adult mice. Bioluminescence imaging, magnetic resonance imaging, and HiRes US were used for in vivo tumor imaging. In addition, brain imaging ex vivo with HiRes US were also performed in three tumor bearing and five normal brains. The brain parenchyma was seen as a homogeneous low echo on HiRes US without locoregional echo differences. An inverted U shaped linear echo structure (fissure) differentiated the telencephalon from the diencephalon. Bilaterally budding structure at the base of the skull represented the trigeminal nerve. The inserted needle, used to implant the glioma cells, was seen as a high linear echogenic reflection. Brain tumor on ex vivo HiRes US was well demarcated, homogeneous and hyperechoic compared to the surrounding healthy brain. In conclusion, imaging the brain with HiRes US in small animal model like mouse is possible and convenient. Real-time guiding is possible to perform any intervention from tumor implantation to percutaneous therapeutic procedures. Ex vivo, HiRes US is extremely useful to study the detailed anatomical features.
文摘High-resolution ultrasound (HRU) imaging is a useful tool to study hyaluronic acid (HA) filler injection in the face. It is noninvasive, quick, well-tolerated, and can provide in vivo and dynamic information. The formations of pools or pearls in HA fillers could be observed real time during injection. The plane of injection could be determined accurately, and there were no specimen manipulation artifacts. It was observed that HA gel fillers with differing production technologies showed distinct spread and distribution patterns in the periocular tissues on HRU examination. The authors used HRU to assess deep injections of CHAP-Hyaluronic Acid (CHAP-HA) fillers for midface lift. 10 patients who underwent bilateral midface deep injections using CHAP-HA filler were examined with HRU before and immediately after treatment, and in 2 weeks and one month later. The CHAP-HA appeared as hypoechoic densities within the preperiosteal plane in HRU. CHAP-HA adopted variable morphology within the tissue depending on individual tissue densities and the compliance of the tissues in the plane of injection. CHAP-HA was unidentifiable with surrounding tissue after one month in 13 of the 20 injection sites. HRU allows in vivo study of CHAP-HA injection behavior and could be a tool for further studies of HA-tissue reactions.
基金Supported by the National Natural Science Foundation of China.
文摘High angular resolution X-ray imaging is always useful in astrophysics and solar physics. In principle, it can be performed by using coded-mask imaging with a very long mask-detector distance. Previously, the diffraction-interference effect was thought to degrade coded-mask imaging performance dramatically at the low energy end with its very long mask-detector distance. The diffraction-interference effect is described with numerical calculations, and the diffraction-interference cross correlation reconstruction method （DICC） is developed in order to overcome the imaging performance degradation. Based on the DICC, a super-high angular resolution principle （SHARP） for coded-mask X-ray imaging is proposed. The feasibility of coded mask imaging beyond the diffraction limit of a single pinhole is demonstrated with simulations. With the specification that the mask element size is 50 × 50 μm^2 and the mask-detector distance is 50 m, the achieved angular resolution is 0.32arcsec above about 10keV and 0.36arcsec at 1.24keV （λ = 1 nm）, where diffraction cannot be neglected. The on-axis source location accuracy is better than 0.02 arcsec. Potential applications for solar observations and wide-field X-ray monitors are also briefly discussed.
文摘High-resolution atomic-beam laser spectroscopy has been performed to study Stark effect of Ba atom. Stark spectra have been observed at various electric fields for Ba highly excited states. The scalar polarizability of the transition from 6s5d3D2 to 5d6p3F3 at 728.0 nm and the tensor polarizability of the 3F3 level have been determined for the first time, to be αs = -89.8 (12) kHz/(kV/cm)2 and αt = -133.7 (20) kHz/(kV/cm)2, respectively.
基金funded by the National Natural Science Foundation of China(Grant Nos.41427804,41421002,41373004)Beijing SHRIMP Center Open Foundation,and Program for Changjiang Scholars and Innovative Research Team in University(Grant No.IRT1281)the MOST Research Foundation from the State Key Laboratory of Continental Dynamics(BJ08132-1)
文摘Silicon isotope analysis traditionally uses a standard-sample bracketing （SSB） method that relies upon greater instrument stability than can be consistently expected. The following proposed method reduces the level of instrumental stability required for the analysis process and provides a valid solution for high-precision and accurate studies of Si isotopic compositions. Rock samples were dissolved by using alkali fusion and acidification. Silicon isotopes were purified with an ion exchange resin. Interfering peaks for isotopes were separated by using a Nu Plasma 1700 multi-collector inductively coupled plasma mass spectrometry （MS） system in high-resolution mode （M/AM 〉 8000 RP）. Two magnesium isotopes （25Mg and 26Mg） and three silicon isotopes （28Si, 29Si, and 3;Si） were analyzed in the same data collection cycle. Mg isotopes were used as an internal standard to calibrate the mass discrimination effects in MS analysis of Si isotopes in combination with the SSB method in order to reduce the effects of MS interference and instrumental mass dis- crimination on the accuracy of measurements. The conventional SSB method without the Mg internal standard and the proposed SSB method with Mg calibration delivered consistent results within two standard deviations. When Mg was used as an internal standard for calibration, the analysis precision was better than 0.05 %0 amu.
基金Project supported by the Goal-Oriented Project Independently Deployed by Institute of Acoustics,Chinese Academy of Sciences (Grant No.MBDX202113)。
文摘High-resolution images of human brain are critical for monitoring the neurological conditions in a portable and safe manner.Sound speed mapping of brain tissues provides unique information for such a purpose.In addition,it is particularly important for building digital human acoustic models,which form a reference for future ultrasound research.Conventional ultrasound modalities can hardly image the human brain at high spatial resolution inside the skull due to the strong impedance contrast between hard tissue and soft tissue.We carry out numerical experiments to demonstrate that the time-domain waveform inversion technique,originating from the geophysics community,is promising to deliver quantitative images of human brains within the skull at a sub-millimeter level by using ultra-sound signals.The successful implementation of such an approach to brain imaging requires the following items:signals of sub-megahertz frequencies transmitting across the inside of skull,an accurate numerical wave equation solver simulating the wave propagation,and well-designed inversion schemes to reconstruct the physical parameters of targeted model based on the optimization theory.Here we propose an innovative modality of multiscale deconvolutional waveform inversion that improves ultrasound imaging resolution,by evaluating the similarity between synthetic data and observed data through using limited length Wiener filter.We implement the proposed approach to iteratively update the parametric models of the human brain.The quantitative imaging method paves the way for building the accurate acoustic brain model to diagnose associated diseases,in a potentially more portable,more dynamic and safer way than magnetic resonance imaging and x-ray computed tomography.
基金supported by a Grant-in-Aid for Scientific Research (No. 24540231)supported by the U.S. National Science Foundation under Award (No. 1009203)
文摘A high angular resolution near-infrared image that shows the intensity of polarization for the GG Tau A binary system was obtained with the Subaru Telescope. The image shows a circumbinary disk scattering the light from the central binary. The azimuthal profile of the intensity of polarization for the circumbinary disk is roughly reproduced by a simple disk model with the Henyey-Greenstein phase function and the Rayleigh function, indicating there are small dust grains at the surface of the disk. Combined with a previous observation of the circumbinary disk, our image indicates that the gap structure in the circumbinary disk orbits counterclockwise, but material in the disk orbits clockwise. We propose that there is a shadow caused by material located between the central binary and the circumbinary disk. The separations and position angles of the stellar components of the binary in the past 20 yr are consistent with the binary orbit with a = 33.4 AU and e = 0.34.
文摘The study was conducted to determine the role of radiological investigation in assessing the severity of COVID-19 pneumonia with the help of chest X-ray (CXR), high resolution computed tomography (HRCT), and ultrasound. This was a retrospective study conducted on 105 COVID-19 patients with symptoms of fever, cough, dyspnea, loss of sense of smell and taste, body ache. Diagnostic tests PCR were positive for COVID-19 included from Medicare Cardiac and General Hospital and Jinnah Medical College Hospital Korangi (JMCH) from April to November 2020. Written informed consent was taken from all participants. This study was approved by ethical review committee, Jinnah Medical & Dental College. Real time-PCR (RT-PCR) was done for the confirmation. Radiological imaging including Chest X-ray, HRCT chest, and ultrasound was done to study the severity of symptoms. Sixty-five patients had mild to moderate symptoms with oxygen saturation between 96% - 98% and 30 patients with severe pneumonia had between saturation 50% - 55%. Patients with mild symptoms were followed up by chest X-ray showing mostly normal chest X-rays but single or patches of ground glass opacities (HRCT). HRCT of 10 patients with low oxygen saturation 50% were already done showing bilateral peripheral patchy consolidation predominantly involving mid and lower lobes. 3 patients presented with patchy lung opacities and ultrasound showing similar findings with pleural effusion and ascites. Radiological imaging, specially CT-Scan was highly significant for diagnosing COVID-19 and severity of infection even in patients with negative PCR. Chest X-ray and ultrasound were also found to be a very useful tool.
文摘Aim: The aim of this study was to determine the effect of training on endothelium-dependent vasodilatation in patients with coronary artery disease (CAD) after revascularization and healthy young men. Background: Impaired endothelial function has been observed in patients with CAD and those with CAD risk factors. Studies have shown that exercise can enhance endothelial function. Methods: This experimental cross-sectional study was conducted on patients with CAD (3 months after CABG and PCI) and students of medical school in 2011. Endothelium dependent dilation of the brachial artery was determined by using high-resolution vascular ultrasonography through flow-mediated vasodilatation (FMD) after induction of ischemia, and the data were analyzed using SPSS, dependent t-test and ANCOVA. Findings: The findings showed that at baseline, FMD was reduced in revascularized patients, when compared with healthy young men, after 8 weeks, and exercise training significantly improved FMD in patients underwent training group [from 4.31 ± 1.45 (SD)% to 6.15 ± 0.773 (SD)%, p p ed unchanged, and even after aerobic training, it did not significantly modify the brachial artery diameter in these groups. Conclusion: Our study demonstrates that endothelial dysfunction persisting in CAD patients after revascularization and aerobic training can improve endothelial function in different vascular beds in CAD patients and healthy young men. This may contribute to the benefit of regular exercise in preventing and restricting cardiovascular disease.
文摘Minimally invasive forehead augmentation is becoming increasingly popular in Asia. However, treatment of the glabella is associated with injection-related complications. The safety of injections can be increased through a thorough understanding of the anatomy and precise injection planes. The authors propose a 3-point injection technique for forehead augmentation in Asian patients that uses CHAP-hyaluronic acid (CHAP-HA) filler. The longevity of the filler was assessed using high-resolution ultrasound (HRU) imaging. Fifteen patients were examined using HRU before and immediately after treatment and at 1 month, 3 months, 6 months, and 12 months. As evident in HRU imaging, CHAP-HA remained visible within surrounding tissue for 6.4 ± 3.7 months. The mean Global Aesthetic Improvement Scale rating was 2.4 ± 0.5 immediately after treatment, 2.8 ± 0.3 at 1 month, 2.7 ± 0.5 at 3 months, 2.1 ± 0.6 at 6 months, and 1.5 ± 0.6 at 12 months. Minimal side effects were reported. The authors demonstrated that CHAP-HA filler may be an optimal candidate for forehead filler augmentation using a 3-point injection technique.
