388 results on '"J.J. Wang"'
Search Results
52. P416. Cerebral Blood Flow and Cardiovascular Risk Factor Effects on Resting Brain Regional Homogeneity
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Bhim Adhikari, L. Elliot Hong, Zhiwei Zhao, Danny J.J. Wang, Paul Thompson, Neda Jahanshad, Alyssa Zhu, Jessica A. Turner, Theo G.M. van Erp, Vince D. Calhoun, Kathryn S. Hatch, Heather Bruce, Stephanie Hare, Joshua Chiappelli, Eric L. Goldwaser, Mark D. Kvarta, Yizhou Ma, Xiaoming Du, Thomas Nichols, Shuo Chen, and Peter Kochunov
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Biological Psychiatry - Published
- 2022
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53. Optimization of pseudo-continuous arterial spin labeling at 7T with parallel transmission B1 shimming
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Lirong Yan, Xingfeng Shao, Kai Wang, Samantha J. Ma, Chenyang Zhao, Danny J.J. Wang, and Qinyang Shou
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Physics ,Intraclass correlation ,Perfusion Imaging ,Brain ,Shim (magnetism) ,Perfusion scanning ,Repeatability ,Arteries ,Nuclear magnetic resonance ,Amplitude ,Parallel communication ,Cerebrovascular Circulation ,Arterial spin labeling ,Humans ,Radiology, Nuclear Medicine and imaging ,Continuous arterial spin labeling ,Computer Simulation ,Spin Labels - Abstract
PURPOSE To optimize pseudo-continuous arterial spin labeling (pCASL) for 7 T, and to further improve the labeling efficiency with parallel RF transmission transmit B1 ( B1+ ) shimming. METHODS pCASL parameters were optimized based on B1+/B0 field distributions at 7 T with simulation. To increase labeling efficiency, the B1+ amplitude at inflowing arteries was increased with parallel RF transmission B1+ shimming. The "indv-shim" with shimming weights calculated for each individual subject, and the "univ-shim" with universal weights calculated on a group of 12 subjects, were compared with circular polarized (CP) shim. The optimized pCASL sequences with three B1+ shimming modes (indv-shim, univ-shim, and CP-shim) were evaluated in 6 subjects who underwent two repeated scans 24 hours apart, along with a pulsed ASL sequence. Quantitative metrics including mean B1+ amplitude, perfusion, and intraclass correlation coefficient were calculated. The optimized 7T pCASL was compared with standard 3T pCASL on 5 subjects, using spatial SNR and temporal SNR. RESULTS The optimal pCASL parameter set (RF duration/gap = 300/250 us, Gave=0.6mT/m,gRatio=10 ) achieved robust perfusion measurement in the presence of B1+/B0 inhomogeneities. Both indv-shim and univ-shim significantly increased B1+ amplitude compared with CP-shim in simulation and in vivo experiment (P < .01). Compared with CP-shim, perfusion signal was increased by 9.5% with indv-shim (P < .05) and by 5.3% with univ-shim (P = .35). All three pCASL sequences achieved fair to good repeatability (intraclass correlation coefficient ≥ 0.5). Compared with 3T pCASL, the optimized 7T pCASL achieved 78.3% higher spatial SNR and 200% higher temporal SNR. CONCLUSION The optimized pCASL achieved robust perfusion imaging at 7 T, while both indv-shim and univ-shim further increased labeling efficiency.
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- 2021
54. A review of transcranial direct current stimulation (tDCS) for the individualized treatment of depressive symptoms
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Katherine L. Narr, Mayank V. Jog, and Danny J.J. Wang
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medicine.medical_specialty ,Transcranial direct-current stimulation ,business.industry ,medicine.medical_treatment ,Neuropsychology ,Stimulation ,medicine.disease ,Article ,Neuromodulation (medicine) ,030227 psychiatry ,03 medical and health sciences ,Psychiatry and Mental health ,Clinical Psychology ,0302 clinical medicine ,Physical medicine and rehabilitation ,Medicine ,Major depressive disorder ,Antidepressant ,Neurology (clinical) ,business ,Treatment-resistant depression ,030217 neurology & neurosurgery ,Depression (differential diagnoses) - Abstract
Transcranial direct current stimulation (tDCS) is a low intensity neuromodulation technique shown to elicit therapeutic effects in a number of neuropsychological conditions. Independent randomized sham-controlled trials and meta- and mega-analyses demonstrate that tDCS targeted to the left dorsolateral prefrontal cortex can produce a clinically meaningful response in patients with major depressive disorder (MDD), but effects are small to moderate in size. However, the heterogeneous presentation, and the neurobiology underlying particular features of depression suggest clinical outcomes might benefit from empirically informed patient selection. In this review, we summarize the status of tDCS research in MDD with focus on the clinical, biological, and intrinsic and extrinsic factors shown to enhance or predict antidepressant response. We also discuss research strategies for optimizing tDCS to improve patient-specific clinical outcomes. TDCS appears suited for both bipolar and unipolar depression, but is less effective in treatment resistant depression. TDCS may also better target core aspects of depressed mood over vegetative symptoms, while pretreatment patient characteristics might inform subsequent response. Peripheral blood markers of gene and immune system function have not yet proven useful as predictors or correlates of tDCS response. Though further research is needed, several lines of evidence suggest that tDCS administered in combination with pharmacological and cognitive behavioral interventions can improve outcomes. Tailoring stimulation to the functional and structural anatomy and/or connectivity of individual patients can maximize physiological response in targeted networks, which in turn could translate to therapeutic benefits.
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- 2019
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55. Differences in high-definition transcranial direct current stimulation over the motor hotspot versus the premotor cortex on motor network excitability
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Allie Schmiesing, Danny J.J. Wang, Stéphanie Lefebvre, Sook-Lei Liew, Kaori L. Ito, Kay Jann, Mayank Jog, and Nicolas Schweighofer
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0301 basic medicine ,Premotor cortex ,Rest ,medicine.medical_treatment ,Science ,Stimulation ,Pilot Projects ,Electromyography ,Biology ,Transcranial Direct Current Stimulation ,050105 experimental psychology ,Article ,Motor network ,03 medical and health sciences ,0302 clinical medicine ,Reference Values ,Functional neuroimaging ,Connectome ,medicine ,Humans ,0501 psychology and cognitive sciences ,Biological Variation, Individual ,Multidisciplinary ,medicine.diagnostic_test ,Transcranial direct-current stimulation ,Functional Neuroimaging ,05 social sciences ,Motor Cortex ,Motor control ,Evoked Potentials, Motor ,Hand ,Magnetic Resonance Imaging ,030104 developmental biology ,medicine.anatomical_structure ,High definition ,Medicine ,Nerve Net ,Primary motor cortex ,Functional magnetic resonance imaging ,Neuroscience ,030217 neurology & neurosurgery - Abstract
The effectiveness of transcranial direct current stimulation (tDCS) placed over the motor hotspot (thought to represent the primary motor cortex (M1)) to modulate motor network excitability is highly variable. The premotor cortex—particularly the dorsal premotor cortex (PMd)—may be a promising alternative target to reliably modulate motor excitability, as it influences motor control across multiple pathways, one independent of M1 and one with direct connections to M1. This double-blind, placebo-controlled preliminary study aimed to differentially excite motor and premotor regions using high-definition tDCS (HD-tDCS) with concurrent functional magnetic resonance imaging (fMRI). HD-tDCS applied over either the motor hotspot or the premotor cortex demonstrated high inter-individual variability in changes on cortical motor excitability. However, HD-tDCS over the premotor cortex led to a higher number of responders and greater changes in local fMRI-based complexity than HD-tDCS over the motor hotspot. Furthermore, an analysis of individual motor hotspot anatomical locations revealed that, in more than half of the participants, the motor hotspot is not located over anatomical M1 boundaries, despite using a canonical definition of the motor hotspot. This heterogeneity in stimulation site may contribute to the variability of tDCS results. Altogether, these preliminary findings provide new considerations to enhance tDCS reliability.
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- 2019
56. Characterization of lenticulostriate arteries with high resolution black-blood T1-weighted turbo spin echo with variable flip angles at 3 and 7 Tesla
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Arthur W. Toga, Yonggang Shi, Danny J.J. Wang, Lirong Yan, Mona Sharifi Sarabi, Samantha J. Ma, Xingfeng Shao, Kay Jann, Qi Yang, and Yue Chen
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Adult ,Middle Cerebral Artery ,genetic structures ,Cognitive Neuroscience ,Black blood ,High resolution ,Tortuosity ,Article ,050105 experimental psychology ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,medicine.artery ,T1 weighted ,medicine ,Humans ,0501 psychology and cognitive sciences ,Aged ,Mathematics ,business.industry ,05 social sciences ,Significant difference ,Middle Aged ,Fast spin echo ,Magnetic Resonance Imaging ,nervous system diseases ,Neurology ,Middle cerebral artery ,Nuclear medicine ,business ,Magnetic Resonance Angiography ,030217 neurology & neurosurgery ,Shape analysis (digital geometry) - Abstract
Objectives The lenticulostriate arteries (LSAs) with small diameters of a few hundred microns take origin directly from the high flow middle cerebral artery (MCA), making them especially susceptible to damage (e.g. by hypertension). This study aims to present high resolution (isotropic ∼0.5 mm), black blood MRI for the visualization and characterization of LSAs at both 3 T and 7 T. Materials and methods T1-weighted 3D turbo spin-echo with variable flip angles (T1w TSE-VFA) sequences were optimized for the visualization of LSAs by performing extended phase graph (EPG) simulations. Twenty healthy volunteers (15 under 35 years old, 5 over 60 years old) were imaged with the T1w TSE-VFA sequences at both 3 T and 7 T. Contrast-to-noise ratio (CNR) was quantified, and LSAs were manually segmented using ITK-SNAP. Automated Reeb graph shape analysis was performed to extract features including vessel length and tortuosity. All quantitative metrics were compared between the two field strengths and two age groups using ANOVA. Results LSAs can be clearly delineated using optimized 3D T1w TSE-VFA at 3 T and 7 T, and a greater number of LSA branches can be detected compared to those by time-of-flight MR angiography (TOF MRA) at 7 T. The CNR of LSAs was comparable between 7 T and 3 T. T1w TSE-VFA showed significantly higher CNR than TOF MRA at the stem portion of the LSAs branching off the medial middle cerebral artery. The mean vessel length and tortuosity were greater on TOF MRA compared to TSE-VFA. The number of detected LSAs by both TSE-VFA and TOF MRA was significantly reduced in aged subjects, while the mean vessel length measured on 7 T TSE-VFA showed significant difference between the two age groups. Conclusion The high-resolution black-blood 3D T1w TSE-VFA sequence offers a new method for the visualization and quantification of LSAs at both 3 T and 7 T, which may be applied for a number of pathological conditions related to the damage of LSAs.
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- 2019
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57. A novel core-shell structure reinforced Zr-based metallic glass composite with combined high strength and good tensile ductility
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Jiaxin Rui, Jialin Cheng, Feng Li, Wei Zhao, J.J. Wang, and Yeling Yun
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Amorphous metal ,Materials science ,Mechanical Engineering ,Composite number ,Metals and Alloys ,Shell (structure) ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Core (optical fiber) ,Brittleness ,Mechanics of Materials ,Phase (matter) ,Materials Chemistry ,Composite material ,0210 nano-technology ,Ductility ,Hardenability - Abstract
Using the ZrO2 particles as precursor, a novel α-Zr/β-Zr core-shell structure reinforced Zr-based metallic glass (Zr-BMG) composite was fabricated. The oxygen is mainly concentrated in the α-Zr core, resulting in the very high hardness of α-Zr core. The β-Zr shell contained the relatively moderate amount of oxygen still has good ductility and work hardenability. The α-Zr/β-Zr core-shell structure reinforced Zr-BMG composite combined the advantages of the soft ductile and hard brittle phase reinforced BMG composites, and thereby exhibits the high strength and good tensile ductility. These findings give a new perspective to adjust the mechanical properties of the BMG composites.
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- 2019
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58. Recent Advances in Pediatric Brain, Spine, and Neuromuscular Magnetic Resonance Imaging Techniques
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Dimitrios C. Karampinos, Danny J.J. Wang, Barbara Cervantes, Eric E. Nelson, Aaron S. McAllister, Ramkumar Krishnamurthy, and Houchun H. Hu
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Central Nervous System ,Adolescent ,Neuroimaging ,Pediatrics ,03 medical and health sciences ,0302 clinical medicine ,Developmental Neuroscience ,030225 pediatrics ,Peripheral Nervous System ,medicine ,Humans ,Child ,Musculoskeletal System ,medicine.diagnostic_test ,Lumbar plexus ,business.industry ,Magnetic resonance neurography ,Simultaneous multislice ,Infant ,Magnetic resonance imaging ,Magnetic Resonance Imaging ,Review article ,Neurology ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,Angiography ,Arterial spin labeling ,Neurology (clinical) ,business ,Brachial plexus ,030217 neurology & neurosurgery ,Biomedical engineering - Abstract
Magnetic resonance imaging (MRI) is a powerful radiologic tool with the ability to generate a variety of proton-based signal contrast from tissues. Owing to this immense flexibility in signal generation, new MRI techniques are constantly being developed, tested, and optimized for clinical utility. In addition, the safe and nonionizing nature of MRI makes it a suitable modality for imaging in children. In this review article, we summarize a few of the most popular advances in MRI techniques in recent years. In particular, we highlight how these new developments have affected brain, spine, and neuromuscular imaging and focus on their applications in pediatric patients. In the first part of the review, we discuss new approaches such as multiphase and multidelay arterial spin labeling for quantitative perfusion and angiography of the brain, amide proton transfer MRI of the brain, MRI of brachial plexus and lumbar plexus nerves (i.e., neurography), and T2 mapping and fat characterization in neuromuscular diseases. In the second part of the review, we focus on describing new data acquisition strategies in accelerated MRI aimed collectively at reducing the scan time, including simultaneous multislice imaging, compressed sensing, synthetic MRI, and magnetic resonance fingerprinting. In discussing the aforementioned, the review also summarizes the advantages and disadvantages of each method and their current state of commercial availability from MRI vendors.
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- 2019
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59. Investigation of the effects of Al on the glass forming ability of Zr-Cu-Ni-Al alloys through their solidification characteristics
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W. Zhao, Feng Li, G. Chen, J.J. Wang, P. Li, and Jialin Cheng
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010302 applied physics ,Microstructural evolution ,Materials science ,Mechanical Engineering ,Al content ,Metallurgy ,Alloy ,Metals and Alloys ,02 engineering and technology ,General Chemistry ,engineering.material ,021001 nanoscience & nanotechnology ,medicine.disease_cause ,01 natural sciences ,Rod ,Glass forming ,Amorphous solid ,Mechanics of Materials ,Phase (matter) ,Mold ,0103 physical sciences ,Materials Chemistry ,engineering ,medicine ,0210 nano-technology - Abstract
The alloying addition was widely and effectively used to develop the new BMGs and improve the glass formation ability (GFA) of the BMG materials. In this study, using the Zr-Cu-Ni-Al system as a mold, the effects of Al addition on both the microstructural evolution and glass forming ability were studied experimentally. The results indicate that when the amount of added Al is less than 10 at. % in the present alloys, Al is dissolved into the phases of ZrCu and Zr2Cu, and does not change the phase competition. However, both the kinetic and thermodynamic conditions for the amorphous formation are enhanced with increasing Al content. The rods of at least 10 mm diameter can be cast fully amorphous for the alloy (Zr57.4Cu33.3Ni9.3)90Al10. When Al content is further increased to 12% or more, some Al-rich Zr51Cu28Al21 (τ3) and Zr38Cu36Al26 (τ5) phases precipitate firstly during solidification, thereby deteriorating the GFA of alloys. These findings give a new perspective to apply alloying addition in a way that enhances the GFA.
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- 2019
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60. 7-Tesla MRI of the brain in a research subject with bilateral, total knee replacement implants: Case report and proposed safety guidelines
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Meng Law, Danny J.J. Wang, Katherin Martin, Giuseppe Barisano, Bozena Culo, Frank G. Shellock, Mary Stevens, Farshid Sepehrband, and Arthur W. Toga
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medicine.medical_specialty ,Research Subjects ,Total knee replacement ,Biomedical Engineering ,Biophysics ,Article ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,7 tesla mri ,Radiology, Nuclear Medicine and imaging ,Medical physics ,Arthroplasty, Replacement, Knee ,Health professionals ,business.industry ,Brain ,Metallic implant ,Prostheses and Implants ,Middle Aged ,Magnetic Resonance Imaging ,Safety guidelines ,Magnetic Fields ,Metals ,Female ,Patient Safety ,Artifacts ,Knee Prosthesis ,business ,030217 neurology & neurosurgery - Abstract
Recently, the first 7-T MR system was approved for clinical use in the United States. Unfortunately, relatively few metallic implants have undergone testing to determine if they are acceptable or pose hazards to research subjects and patients at this ultra-high-field strength. Therefore, in lieu of not performing a research or clinical MRI exam at 7-T, the supervising physician may make a decision to scan the individual with an untested metallic implant based on an analysis of the risks vs. the benefits. We present a case report of a research subject with bilateral, total knee replacement implants that safely underwent MRI of the brain at 7-T and provide guidelines for healthcare professionals to follow in order to ensure safety in research subjects or patients with metallic implants referred for 7-T scans.
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- 2019
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61. Acicular martensite induced superior strength-ductility combination in a 20Cr2Ni2MoV steel
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Y.L. Wang, Y.F. Shen, N. Jia, J.J. Wang, and S.-X. Zhao
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,Condensed Matter Physics - Published
- 2022
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62. Ultrasonic nonlinear evaluation of tensile plastic damage in Nickel based single crystal superalloy
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J.J. Wang, Z.X. Wen, H.Q. Pei, C.J. Zhang, Y.M. Zhang, and Z.F. Yue
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Mechanical Engineering ,General Materials Science ,Condensed Matter Physics - Published
- 2022
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63. Strength of a compacted mudstone
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J.J. Wang and R.H. Chen
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- 2021
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64. Mapping human brain function with massively parallel high-speed three-dimensional photoacoustic computed tomography
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Li Lin, Shuai Na, Danny J.J. Wang, Kay Jann, Lirong Yan, Junhui Shi, Peng Hu, Jonathan J. Russin, Charles Y. Liu, Konstantin Maslov, Xiaoyun Yuan, and Lihong V. Wang
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Functional imaging ,medicine.anatomical_structure ,medicine.diagnostic_test ,Computer science ,medicine ,Photoacoustic imaging in biomedicine ,7 tesla mri ,Computed tomography ,Field of view ,Human brain ,Pact ,Massively parallel ,Biomedical engineering - Abstract
Photoacoustic computed tomography (PACT) has been extensively explored in animal brains but never in the human brain due to its limited field of view (FOV), imaging speed, penetration depth, and sensitivity. Here, we present the first application of PACT in functional human brain imaging. Motor and language functional tasks were employed and performed by post-hemicraniectomy patients. The brain activities were recorded at a 10-cm–diameter FOV, 350-μm/2-s spatiotemporal resolution, and ~2-cm penetration depth using a newly developed massively parallel three-dimensional PACT system. Quantitative validation of the PACT results against 7 Tesla MRI revealed comparable angiographic structures and functional activation in the same FOV. The obtained results represent a critical step toward broader-scope human brain imaging applications using PACT technology.
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- 2021
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65. Massively parallel functional photoacoustic computed tomography of the human brain
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Kay Jann, Lihong V. Wang, Jonathan J. Russin, Junhui Shi, Danny J.J. Wang, Shuai Na, Peng Hu, Charles Y. Liu, Konstantin Maslov, Lirong Yan, Xiaoyun Yuan, and Li Lin
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0301 basic medicine ,Transducers ,Biomedical Engineering ,Medicine (miscellaneous) ,Photoacoustic imaging in biomedicine ,Bioengineering ,Field of view ,Article ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Massively parallel ,Tomography ,Physics ,medicine.diagnostic_test ,Human head ,Brain ,Human brain ,equipment and supplies ,Magnetic Resonance Imaging ,Computer Science Applications ,Functional imaging ,030104 developmental biology ,medicine.anatomical_structure ,Ultrasonic sensor ,Functional magnetic resonance imaging ,Tomography, X-Ray Computed ,Head ,030217 neurology & neurosurgery ,Biotechnology ,Biomedical engineering - Abstract
Blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging of the human brain requires bulky equipment for the generation of magnetic fields. Photoacoustic computed tomography obviates the need for magnetic fields by using light and sound to measure deoxyhaemoglobin and oxyhaemoglobin concentrations to then quantify oxygen saturation and blood volumes. Yet, the available imaging speeds, fields of view (FOV), sensitivities and penetration depths have been insufficient for functional imaging of the human brain. Here, we show that massively parallel ultrasonic transducers arranged hemispherically around the human head can produce tomographic images of the brain with a 10-cm-diameter FOV and spatial and temporal resolutions of 350 µm and 2 s, respectively. In patients who had a hemicraniectomy, a comparison of functional photoacoustic computed tomography and 7 T BOLD functional magnetic resonance imaging showed a strong spatial correspondence in the same FOV and a high temporal correlation between BOLD signals and photoacoustic signals, with the latter enabling faster detection of functional activation. Our findings establish the use of photoacoustic computed tomography for human brain imaging. Massively parallel ultrasonic transducers arranged hemispherically around the human head enable functional photoacoustic computed tomography of the human brain with a 10-cm-diameter field of view and resolutions of 350 µm and 2 s.
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- 2021
66. Tributyrin supplementation in pasteurized waste milk: Effects on growth performance, health, and blood parameters of dairy calves
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Shuangtao Li, Wei Wang, J.Y. Ma, Gibson Maswayi Alugongo, Jie Zhou, Shuai Liu, J.H. Li, Zhijun Cao, Y. Wang, J.J. Wang, Jianxin Xiao, and J.D. Wu
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Globulin ,Tributyrin ,Pasteurization ,Weaning ,Feed conversion ratio ,law.invention ,chemistry.chemical_compound ,Animal science ,Starter ,law ,Genetics ,Animals ,Triglycerides ,biology ,Chemistry ,Body Weight ,Albumin ,Animal Feed ,Diet ,Milk ,Dietary Supplements ,biology.protein ,Hay ,Animal Science and Zoology ,Cattle ,Female ,Food Science - Abstract
This study evaluated the effects of incremental tributyrin supplementation in pasteurized waste milk on growth performance, health, and blood metabolism of dairy calves before and after weaning. Forty-eight newborn female Holstein dairy calves (39.6 ± 2.75 kg; mean ± standard deviation) were blocked by age and randomly assigned to 3 treatments: pasteurized waste milk (1) without supplementation, (2) with 1 g/L of tributyrin products (unprotected solid powder; containing 35% tributyrin), or (3) with 2 g/L of tributyrin products. The calves were weaned on d 56 and were raised until d 77. Data were analyzed for the preweaning, postweaning, and overall periods. The results showed that starter intake and hay intake were not different among treatments in any period of the trial, but the crude protein intake tended to increase linearly with tributyrin supplementation during the overall period. Although tributyrin supplementation had no effects on body weight during preweaning and overall periods, body weight increased linearly with tributyrin supplementation postweaning. The average daily gain tended to increase linearly during postweaning and overall periods. No effects were observed on feed efficiency in any period. A positive linear relationship between body length and tributyrin supplementation was observed during the postweaning period, but no differences were found for the other body structural measurements in any period. The results of diarrhea showed that tributyrin concentration had a negative linear relationship with diarrhea frequency during preweaning and overall periods. The rectal temperature did not differ among treatments in any period, but a treatment × week effect for rectal body temperature was observed. For blood metabolism, tributyrin supplementation had no effects on insulin, growth hormone, total protein, albumin, or globulin. No differences were found in serum amyloid A concentration in any of the periods, yet haptoglobin concentration decreased linearly with increasing tributyrin concentration during postweaning and overall periods. Endothelin concentration showed a tendency to decrease linearly during preweaning and postweaning periods and decreased linearly with tributyrin supplementation during the overall period. An increasing tributyrin concentration was associated with a negative linear relationship with IL-1β concentration during the preweaning period, and no differences were found in the other periods. The concentration of IL-6 and tumor necrosis factor α were not different among treatments in any of the periods. These data suggest that increasing the concentration of tributyrin in pasteurized waste milk could increase growth performance and health of dairy calves, and incremental tributyrin supplementation could linearly reduce haptoglobin, endothelin, and IL-1β concentrations, indicating a positive effect of tributyrin on alleviating oxidative stress and inflammatory status of dairy calves. Calves fed pasteurized waste milk supplemented with tributyrin products (containing 35% tributyrin) at 2 g/L compared with 1 g/L of milk had more improved growth and health.
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- 2021
67. MarkVCID cerebral small vessel consortium: II. Neuroimaging protocols
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Hanzhang Lu, Eric E. Smith, Karl G. Helmer, Brian T. Gold, Amir H. Kashani, Steven M. Greenberg, Herpreet Singh, Andre van der Kouwe, Kristin Schwab, Roderick A. Corriveau, Danny J.J. Wang, Claudia L. Satizabal, Bruce Fischl, Konstantinos Arfanakis, Arvind Caprihan, Pauline Maillard, Lara Stables, Yang Li, and Charles DeCarli
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Male ,Aging ,small vessel disease ,Epidemiology ,quality assurance ,Fluid-attenuated inversion recovery ,030218 nuclear medicine & medical imaging ,0302 clinical medicine ,acquisition protocol ,magnetic resonance imaging ,Stroke ,Tomography ,screening and diagnosis ,medicine.diagnostic_test ,Health Policy ,Angiography ,Brain ,Magnetic Resonance Imaging ,Psychiatry and Mental health ,Detection ,Neurological ,Biomarker (medicine) ,biomarker ,Biomedical Imaging ,Female ,Tomography, Optical Coherence ,4.2 Evaluation of markers and technologies ,medicine.medical_specialty ,optical computed tomography angiography ,MarkVCID Consortium ,Clinical Sciences ,Neuroimaging ,Article ,Imaging phantom ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,Developmental Neuroscience ,Clinical Research ,medicine ,Dementia ,Humans ,vascular contributions to cognitive impairment and dementia ,Medical physics ,Cognitive Dysfunction ,Aged ,Protocol (science) ,business.industry ,Neurosciences ,Magnetic resonance imaging ,medicine.disease ,Brain Disorders ,Optical Coherence ,Geriatrics ,Cerebral Small Vessel Diseases ,Neurology (clinical) ,Geriatrics and Gerontology ,business ,030217 neurology & neurosurgery ,Biomarkers - Abstract
The MarkVCID consortium was formed under cooperative agreements with the National Institute of Neurologic Diseases and Stroke (NINDS) and National Institute on Aging (NIA) in 2016 with the goals of developing and validating biomarkers for the cerebral small vessel diseases associated with the vascular contributions to cognitive impairment and dementia (VCID). Rigorously validated biomarkers have consistently been identified as crucial for multicenter studies to identify effective strategies to prevent and treat VCID, specifically to detect increased VCID risk, diagnose the presence of small vessel disease and its subtypes, assess prognosis for disease progression or response to treatment, demonstrate target engagement or mechanism of action for candidate interventions, and monitor disease progression during treatment. The seven project sites and central coordinating center comprising MarkVCID, working with NINDS and NIA, identified a panel of 11 candidate fluid- and neuroimaging-based biomarker kits and established harmonized multicenter study protocols (see companion paper "MarkVCID cerebral small vessel consortium: I. Enrollment, clinical, fluid protocols" for full details). Here we describe the MarkVCID neuroimaging protocols with specific focus on validating their application to future multicenter trials. MarkVCID procedures for participant enrollment; clinical and cognitive evaluation; and collection, handling, and instrumental validation of fluid samples are described in detail in a companion paper. Magnetic resonance imaging (MRI) has long served as the neuroimaging modality of choice for cerebral small vessel disease and VCID because of its sensitivity to a wide range of brain properties, including small structural lesions, connectivity, and cerebrovascular physiology. Despite MRI's widespread use in the VCID field, there have been relatively scant data validating the repeatability and reproducibility of MRI-based biomarkers across raters, scanner types, and time intervals (collectively defined as instrumental validity). The MRI protocols described here address the core MRI sequences for assessing cerebral small vessel disease in future research studies, specific sequence parameters for use across various research scanner types, and rigorous procedures for determining instrumental validity. Another candidate neuroimaging modality considered by MarkVCID is optical coherence tomography angiography (OCTA), a non-invasive technique for directly visualizing retinal capillaries as a marker of the cerebral capillaries. OCTA has theoretical promise as a unique opportunity to visualize small vessels derived from the cerebral circulation, but at a considerably earlier stage of development than MRI. The additional OCTA protocols described here address procedures for determining OCTA instrumental validity, evaluating sources of variability such as pupil dilation, and handling data to maintain participant privacy. MRI protocol and instrumental validation The core sequences selected for the MarkVCID MRI protocol are three-dimensional T1-weighted multi-echo magnetization-prepared rapid-acquisition-of-gradient-echo (ME-MPRAGE), three-dimensional T2-weighted fast spin echo fluid-attenuated-inversion-recovery (FLAIR), two-dimensional diffusion-weighted spin-echo echo-planar imaging (DWI), three-dimensional T2*-weighted multi-echo gradient echo (3D-GRE), three-dimensional T2 -weighted fast spin-echo imaging (T2w), and two-dimensional T2*-weighted gradient echo echo-planar blood-oxygenation-level-dependent imaging with brief periods of CO2 inhalation (BOLD-CVR). Harmonized parameters for each of these core sequences were developed for four 3 Tesla MRI scanner models in widespread use at academic medical centers. MarkVCID project sites are trained and certified for their instantiation of the consortium MRI protocols. Sites are required to perform image quality checks every 2 months using the Alzheimer's Disease Neuroimaging Initiative phantom. Instrumental validation for MarkVCID MRI-based biomarkers is operationally defined as inter-rater reliability, test-retest repeatability, and inter-scanner reproducibility. Assessments of these instrumental properties are performed on individuals representing a range of cerebral small vessel disease from mild to severe. Inter-rater reliability is determined by distribution of an independent dataset of MRI scans to each analysis site. Test-retest repeatability is determined by repeat MRI scans performed on individual participants on a single MRI scanner after a short (1- to 14-day) interval. Inter-scanner reproducibility is determined by repeat MRI scans performed on individuals performed across four MRI scanner models. OCTA protocol and instrumental validation The MarkVCID OCTA protocol uses a commercially available, Food and Drug Administration-approved OCTA apparatus. Imaging is performed on one dilated and one undilated eye to assess the need for dilation. Scans are performed in quadruplicate. MarkVCID project sites participating in OCTA validation are trained and certified by this biomarker's lead investigator. Inter-rater reliability for OCTA is assessed by distribution of OCTA datasets to each analysis site. Test-retest repeatability is assessed by repeat OCTA imaging on individuals on the same day as their baseline OCTA and a different-day repeat session after a short (1- to 14-day) interval. Methods were developed to allow the OCTA data to be de-identified by the sites before transmission to the central data management system. The MarkVCID neuroimaging protocols, like the other MarkVCID procedures, are designed to allow translation to multicenter trials and as a template for outside groups to generate directly comparable neuroimaging data. The MarkVCID neuroimaging protocols are available to the biomedical community and intended to be shared. In addition to the instrumental validation procedures described here, each of the neuroimaging MarkVCID kits will undergo biological validation to determine its ability to measure important aspects of VCID such as cognitive function. The analytic methods for the neuroimaging-based kits and the results of these validation studies will be published separately. The results will ultimately determine the neuroimaging kits' potential usefulness for multicenter interventional trials in small vessel disease-related VCID.
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- 2021
68. Retrospective motion artifact correction of structural MRI images using deep learning improves the quality of cortical surface reconstructions
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Farshid Sepehrband, Danny J.J. Wang, Arthur W. Toga, Hosung Kim, Ben A. Duffy, Joyce Min, Lu Zhao, and Yonggang Shi
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Adult ,Male ,Adolescent ,Databases, Factual ,Image quality ,Computer science ,Cognitive Neuroscience ,Parkinson's disease ,Convolutional neural network ,050105 experimental psychology ,Motion (physics) ,Article ,Cortical thickness ,lcsh:RC321-571 ,Cortical surface ,03 medical and health sciences ,Motion ,Young Adult ,0302 clinical medicine ,Quality (physics) ,Deep Learning ,Neuroimaging ,Motion artifacts ,Image Processing, Computer-Assisted ,Humans ,0501 psychology and cognitive sciences ,Autistic Disorder ,Child ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,Retrospective Studies ,Cerebral Cortex ,Artifact (error) ,T1 ,business.industry ,Deep learning ,05 social sciences ,Pattern recognition ,Middle Aged ,Magnetic Resonance Imaging ,Motion artifact ,Neurology ,Female ,Artificial intelligence ,business ,Artifacts ,030217 neurology & neurosurgery - Abstract
Head motion during MRI acquisition presents significant challenges for neuroimaging analyses. In this work, we present a retrospective motion correction framework built on a Fourier domain motion simulation model combined with established 3D convolutional neural network (CNN) architectures. Quantitative evaluation metrics were used to validate the method on three separate multi-site datasets. The 3D CNN was trained using motion-free images that were corrupted using simulated artifacts. CNN based correction successfully diminished the severity of artifacts on real motion affected data on a separate test dataset as measured by significant improvements in image quality metrics compared to a minimal motion reference image. On the test set of 13 image pairs, the mean peak signal-to-noise-ratio was improved from 31.7 to 33.3 dB. Furthermore, improvements in cortical surface reconstruction quality were demonstrated using a blinded manual quality assessment on the Parkinson's Progression Markers Initiative (PPMI) dataset. Upon applying the correction algorithm, out of a total of 617 images, the number of quality control failures was reduced from 61 to 38. On this same dataset, we investigated whether motion correction resulted in a more statistically significant relationship between cortical thickness and Parkinson's disease. Before correction, significant cortical thinning was found to be restricted to limited regions within the temporal and frontal lobes. After correction, there was found to be more widespread and significant cortical thinning bilaterally across the temporal lobes and frontal cortex. Our results highlight the utility of image domain motion correction for use in studies with a high prevalence of motion artifacts, such as studies of movement disorders as well as infant and pediatric subjects.
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- 2021
69. Advanced pCASL pediatric perfusion MRI
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Danny J.J. Wang, Xingfeng Shao, and Emily Kilroy
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Brain development ,Neuroimaging ,business.industry ,Medicine ,Transit time ,Blood flow ,Nuclear medicine ,business ,Perfusion ,Spin labeled ,Pediatric population - Abstract
Arterial spin labeled (ASL) perfusion MRI is an appealing neuroimaging technology to study brain development due to its entirely noninvasive nature and several physiological properties of a child brain. In this chapter, we discussed 1. How physiological parameter variations (blood T1, arterial transit time and blood flow velocity) of the pediatric population affect the accuracy of perfusion quantification; 2. Current research on perfusion across typical brain development and neurodevelopmental disorders; and 3. New technical developments to improve spatial resolution, quantification accuracy and robustness to motion for pediatric ASL studies.
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- 2021
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70. Laser dewetting mechanism and antibacterial properties of Cu-Al based medium entropy alloy films
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J.J. Wang, H.K. Lin, W.S. Chuang, C.Y. Chuang, Yi-Hsien Lin, J.C. Huang, and Ying-Hong Lin
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Mechanics of Materials ,Mechanical Engineering ,Materials Chemistry ,Metals and Alloys - Published
- 2022
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71. Assessment of carotid stiffness by measuring carotid pulse wave velocity using a single-slice oblique-sagittal phase-contrast MRI
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Danny J.J. Wang, Soroush Heidari Pahlavian, Xiaoming Bi, Steven Cen, Lirong Yan, and Helena Chang Chui
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Pulse Wave Analysis ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Vascular Stiffness ,Region of interest ,medicine.artery ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Common carotid artery ,Pulse wave velocity ,Aged ,Retrospective Studies ,business.industry ,medicine.disease ,Neurovascular bundle ,Magnetic Resonance Imaging ,Sagittal plane ,Peripheral ,medicine.anatomical_structure ,Carotid Arteries ,cardiovascular system ,Arterial stiffness ,Internal carotid artery ,Nuclear medicine ,business ,030217 neurology & neurosurgery ,Blood Flow Velocity - Abstract
PURPOSE Increased arterial stiffness has been shown to be one of the earliest markers of cerebrovascular dysfunction. As a surrogate marker of arterial stiffness, pulse wave velocity (PWV) quantifications are generally carried out on central and peripheral arteries. The purpose of this study was to develop and evaluate an MRI approach to assess carotid stiffness by measuring carotid PWV (cPWV) using a fast oblique-sagittal phase-contrast MRI sequence. METHODS In 29 volunteers, a single-slice oblique-sagittal phase-contrast MRI sequence with retrospective cardiac gating was used to quantify blood velocity waveforms along a vessel segment covering the common carotid artery (CCA) and the internal carotid artery (ICA). The CCA-ICA segment length was measured from a region of interest selected on the magnitude image. Phase-contrast MRI-measured velocities were also used to quantify the ICA pulsatility index along with cPWV quantification. RESULTS The mean value of cPWV calculated using the middle upslope area algorithm was 2.86 ± 0.71 and 3.97 ± 1.14 m/s in young and elderly subjects, respectively. Oblique-sagittal phase-contrast MRI-derived cPWV measurements showed excellent intrascan and interscan repeatability. cPWV and ICA pulsatility index were significantly greater in older subjects compared to those in the young subjects (P < .01 and P = .01, respectively). Also, increased cPWV values were associated with elevated systolic blood pressure (β = 0.05, P = .03). CONCLUSION This study demonstrated that oblique-sagittal phase-contrast MRI is a feasible technique for the quantification of both cPWV and ICA pulsatility index and showed their potential utility in evaluating cerebroarterial aging and age-related neurovascular disorders.
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- 2020
72. Plasma tau is negatively correlated with frontal lobe CBF in hypertensive adults on the AD spectrum
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Jared R. Brosch, Martin R. Farlow, Evgeny J. Chumin, John D. West, Shannon L. Risacher, Brenna C. McDonald, Sujuan Gao, Henrik Zetterberg, Rachael L. Deardorff, Yu-Chien Wu, Aaron P. Kamer, Kaj Blennow, Andrew J. Saykin, Liana G. Apostolova, Eileen F. Tallman, Danny J.J. Wang, Fred Unverzagt, and Cecily G. Swinford
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Psychiatry and Mental health ,Cellular and Molecular Neuroscience ,Nuclear magnetic resonance ,Developmental Neuroscience ,Frontal lobe ,Epidemiology ,business.industry ,Health Policy ,Medicine ,Neurology (clinical) ,Geriatrics and Gerontology ,business - Published
- 2020
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73. Blood‐brain barrier dysfunction and perioperative neurocognitive disorders: Cognitive Recovery after Elective Surgery (CREATES) study design and methods
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Danny J.J. Wang, Sharon K. Inouye, Sid E. O'Bryant, William G. Cioffi, Geoffrey Tremont, Mark C. Kendall, Lori A. Daiello, Richard N. Jones, Gildasio S. De Oliveira, Jerrold L. Boxerman, and Brian R. Ott
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medicine.medical_specialty ,Epidemiology ,business.industry ,Health Policy ,Cognition ,Perioperative ,Blood–brain barrier ,Psychiatry and Mental health ,Cellular and Molecular Neuroscience ,medicine.anatomical_structure ,Developmental Neuroscience ,Neuroimaging ,medicine ,Neurology (clinical) ,Geriatrics and Gerontology ,Elective surgery ,business ,Intensive care medicine ,Neurocognitive - Published
- 2020
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74. Detection of attenuated dynamic cerebrovascular function in aging and cognitive decline using a novel neuroimaging approach
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Aimee Gaubert, Yanrong Li, Anisa Marshall, Daniel A. Nation, Anna E. Blanken, Danny J.J. Wang, Belinda Yew, Xingfeng Shao, Isabel J. Sible, Jung Yun Jang, Shubir Dutt, and Jean K. Ho
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Epidemiology ,business.industry ,Health Policy ,media_common.quotation_subject ,Psychiatry and Mental health ,Cellular and Molecular Neuroscience ,Developmental Neuroscience ,Neuroimaging ,Medicine ,Neurology (clinical) ,Geriatrics and Gerontology ,Cognitive decline ,Function (engineering) ,business ,Neuroscience ,media_common - Published
- 2020
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75. Water exchange across blood‐brain barrier is associated with CSF amyloid‐42 level in healthy older adults
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Xingfeng Shao, Danny J.J. Wang, and Brian T. Gold
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medicine.medical_specialty ,Amyloid ,Epidemiology ,business.industry ,Health Policy ,Water exchange ,Blood–brain barrier ,Psychiatry and Mental health ,Cellular and Molecular Neuroscience ,Endocrinology ,medicine.anatomical_structure ,Developmental Neuroscience ,Internal medicine ,medicine ,Neurology (clinical) ,Geriatrics and Gerontology ,business - Published
- 2020
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76. Mean arterial pressure during cerebral perfusion MRI: An arterial spin‐labeling study in younger and older adults
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Isabel J. Sible, Anisa Marshall, Belinda Yew, Aimee Gaubert, Yanrong Li, Shubir Dutt, Arunima Kapoor, Jean K. Ho, Jung Yun Jang, Anna E. Blanken, Daniel A. Nation, Danny J.J. Wang, and Xingfeng Shao
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medicine.medical_specialty ,Mean arterial pressure ,Epidemiology ,business.industry ,Health Policy ,Psychiatry and Mental health ,Cellular and Molecular Neuroscience ,Developmental Neuroscience ,Internal medicine ,Arterial spin labeling ,medicine ,Cardiology ,Neurology (clinical) ,Geriatrics and Gerontology ,Cerebral perfusion pressure ,business - Published
- 2020
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77. Abstract 13327: Worse Cerebral Blood Flow in Single Right verses Left Ventricle After Fontan Completion
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Rajesh Kumar, Bhaswati Roy, Nancy A. Pike, Mary A. Woo, Danny J.J. Wang, Alan B. Lewis, and Nancy J Halnon
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medicine.medical_specialty ,Single left ventricle ,Heart disease ,business.industry ,Single right ventricle ,medicine.disease ,medicine.anatomical_structure ,Cerebral blood flow ,Ventricle ,Physiology (medical) ,Internal medicine ,medicine ,Cardiology ,Cardiology and Cardiovascular Medicine ,Cognitive impairment ,business - Abstract
Introduction: Single ventricle heart disease (SVHD) adolescents with a single right ventricle (RV) have worse cognition and mood function compared to single left ventricle (LV) which may result from variability in ventricular function or structure related sequela after Fontan completion. However, it is unclear whether RV SVHD has worse cerebral blood flow (CBF) in cognitive and mood regulatory areas over LV SVHD compared to healthy controls. Methods: Cross-sectional, comparative design, 14 adolescents with RV SVHD (age 16.1±1.5 years; 7 male), 6 LV SVHD (age, 16.3±1.0 years; 4 male), and 25 healthy controls (age, 15.9±1.4 years; 13 male) were studied. SVHD participants were recruited who have undergone surgical palliation with Fontan completion from local pediatric cardiology clinics. Self-reported healthy controls were recruited from the community. Brain MRI studies were performed using a 3.0-Tesla MRI scanner and 3D pseudo-continuous arterial spin labelling data were collected. We calculated whole-brain CBF maps, normalized to a common space, and assessed brain changes between RV and LV SVHD and controls [ANCOVA; covariates, age and sex; p Results: Regional brain CBF was reduced in single RV over LV SVHD. Multiple brain sites showed more widespread reduced CBF values in RV over LV SVHD compared to controls (Figure 1, p Conclusion: Single RV adolescents show more widespread reduced CBF than single LV in cognitive and mood regulatory sites, which may result from variable function or structure related sequela between ventricle types. The findings indicate that the therapeutic approach should recognize the differences in CBF based on ventricle type and investigate interventions to optimize CBF in single RV SVHD.
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- 2020
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78. Heavy Ion and Proton Induced Single Event Effects on Microchip RT PolarFire FPGA
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N. Rezzak, J.J. Wang, R. Chipana, C. Lao, G. Bakker, F. Hawley, and E. Hamdy
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- 2020
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79. Optimization of adiabatic pulses for pulsed arterial spin labeling at 7 tesla: Comparison with pseudo-continuous arterial spin labeling
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Samantha J. Ma, Xingfeng Shao, Jin Jin, Lirong Yan, Danny J.J. Wang, and Kai Wang
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Materials science ,Pulse (signal processing) ,Truncation ,Phantoms, Imaging ,Quantitative Biology::Tissues and Organs ,Physics::Medical Physics ,Specific absorption rate ,Arteries ,Signal ,Magnetic Resonance Imaging ,Imaging phantom ,Article ,030218 nuclear medicine & medical imaging ,Perfusion ,03 medical and health sciences ,0302 clinical medicine ,Nuclear magnetic resonance ,Amplitude ,Cerebrovascular Circulation ,Frequency offset ,Humans ,Radiology, Nuclear Medicine and imaging ,Spin Labels ,Wideband ,030217 neurology & neurosurgery - Abstract
PURPOSE To optimize and evaluate adiabatic pulses for pulsed arterial spin labeling at ultrahigh field 7 tesla. METHODS Four common adiabatic inversion pulses, including hyperbolic secant, wideband uniform rate smooth truncation, frequency offset corrected inversion, and time-resampled frequency offset corrected inversion pulses, were optimized based on a custom-defined loss function that included labeling efficiency and inversion band uniformity. The optimized pulses were implemented in flow-sensitive alternating inversion recovery sequences and tested on phantom and 11 healthy volunteers with 2 constraints: 1) specific absorption rate normalized; and 2) equal peak RF amplitude, respectively. A pseudo-continuous arterial spin labeling sequence was implemented for comparison. Quantitative metrics such as perfusion and relative labeling efficiency versus residual tissue signal were calculated. RESULTS Among the 4 pulses, the wideband uniform rate smooth truncation pulse yielded the lowest loss in simulation and achieved a good balance between labeling efficiency and residual tissue signal from both phantom and in vivo experiments. Wideband uniform rate smooth truncation-pulsed arterial spin labeling showed significantly higher relative labeling efficiency compared to the other sequences (P < .01), whereas the perfusion signal was increased by 40% when the highest B1+ amplitude was used. The 4 pulsed arterial spin labeling sequences yielded comparable perfusion signals compared to pseudo-continuous arterial spin labeling but with less than half the specific absorption rate. CONCLUSION Optimized wideband uniform rate smooth truncation pulse with the highest B1+ amplitude allowed was recommended for 7 tesla pulsed arterial spin labeling.
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- 2020
80. Reperfusion Into Severely Damaged Brain Tissue Is Associated With Occurrence of Parenchymal Hemorrhage for Acute Ischemic Stroke
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Songlin Yu, Samantha J. Ma, David S Liebeskind, Jeffrey L. Saver, Xin J Qiao, Lirong Yan, Noriko Salamon, and Danny J.J. Wang
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medicine.medical_specialty ,medicine.medical_treatment ,Infarction ,lcsh:RC346-429 ,03 medical and health sciences ,0302 clinical medicine ,Hematoma ,Internal medicine ,Parenchyma ,medicine ,030212 general & internal medicine ,Myocardial infarction ,hemorrhagic transformation (HT) ,lcsh:Neurology. Diseases of the nervous system ,Original Research ,business.industry ,Area under the curve ,Thrombolysis ,medicine.disease ,reperfusion injury ,reperfusion ,Neurology ,Cardiology ,acute ischemic stroke (AIS) ,Neurology (clinical) ,business ,Reperfusion injury ,030217 neurology & neurosurgery ,TIMI ,arterial spin labeling (ASL) - Abstract
Background and Purpose: This study aims to quantify the reperfusion status within severely damaged brain tissue and to evaluate its relationship with high grade of hemorrhagic transformation (HT).Methods: Pseudo-continuous ASL was performed along with DWI in 102 patients within 24 h post-treatments. The infarction core was identified using ADC values
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- 2020
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81. Concurrent Imaging of Markers of Current Flow and Neurophysiological Changes During tDCS
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Kay Jann, Yu Huang, Danny J.J. Wang, Lucas C. Parra, Lirong Yan, Marom Bikson, Mayank Jog, and Katherine L. Narr
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Computer science ,medicine.medical_treatment ,Blood oxygenation level dependent ,current mapping ,tDCS ,050105 experimental psychology ,Imaging phantom ,lcsh:RC321-571 ,03 medical and health sciences ,0302 clinical medicine ,resting-state ,Methods ,medicine ,Bold fmri ,0501 psychology and cognitive sciences ,BOLD fMRI ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,dual-echo echo planar imaging (DE-EPI) ,Group level ,Transcranial direct-current stimulation ,Resting state fMRI ,General Neuroscience ,05 social sciences ,Neurophysiology ,Neuromodulation (medicine) ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Despite being a popular neuromodulation technique, clinical translation of transcranial direct current stimulation (tDCS) is hampered by variable responses observed within treatment cohorts. Addressing this challenge has been difficult due to the lack of an effective means of mapping the neuromodulatory electromagnetic fields together with the brain’s response. In this study, we present a novel imaging technique that provides the capability of concurrently mapping markers of tDCS currents, as well as the brain’s response to tDCS. A dual-echo echo-planar imaging (DE-EPI) sequence is used, wherein the phase of the acquired MRI-signal encodes the tDCS current induced magnetic field, while the magnitude encodes the blood oxygenation level dependent (BOLD) contrast. The proposed technique was first validated in a custom designed phantom. Subsequent test–retest experiments in human participants showed that tDCS-induced magnetic fields can be detected reliably in vivo. The concurrently acquired BOLD data revealed large-scale networks characteristic of a brain in resting-state as well as a ‘cathodal’ and an ‘anodal’ resting-state component under each electrode. Moreover, ‘cathodal’s BOLD-signal was observed to significantly decrease with the applied current at the group level in all datasets. With its ability to image markers of electromagnetic cause as well as neurophysiological changes, the proposed technique may provide an effective means to visualize neural engagement in tDCS at the group level. Our technique also contributes to addressing confounding factors in applying BOLD fMRI concurrently with tDCS.
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- 2020
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82. Robust functional mapping of layer-selective responses in human lateral geniculate nucleus with high-resolution 7T fMRI
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Yan Zhuo, Zhentao Zuo, Yazhu Qian, Jing An, Danny J.J. Wang, Jinyou Zou, Peng Zhang, and Zihao Zhang
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Cell type ,Visual perception ,genetic structures ,Thalamus ,Biology ,Lateral geniculate nucleus ,General Biochemistry, Genetics and Molecular Biology ,030218 nuclear medicine & medical imaging ,Neuroscience and Cognition ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Vision, Ocular ,General Environmental Science ,Visual Cortex ,Brain Mapping ,Monocular ,General Immunology and Microbiology ,medicine.diagnostic_test ,Geniculate Bodies ,Cognition ,General Medicine ,Magnetic Resonance Imaging ,eye diseases ,Visual cortex ,medicine.anatomical_structure ,nervous system ,Visual Perception ,sense organs ,General Agricultural and Biological Sciences ,Functional magnetic resonance imaging ,Neuroscience ,030217 neurology & neurosurgery ,psychological phenomena and processes - Abstract
The lateral geniculate nucleus (LGN) of the thalamus is the major subcortical relay of retinal input to the visual cortex. It plays important roles in visual perception and cognition and is closely related with several eye diseases and brain disorders. Primate LGNs mainly consist of six layers of monocular neurons with distinct cell types and functions. The non-invasive measure of layer-selective activities of the human LGN would have broad scientific and clinical implications. Using high-resolution functional magnetic resonance imaging (fMRI) at 7 Tesla (T) and carefully designed visual stimuli, we achieved robust functional mapping of eye-specific and also magnocellular/parvocellular-specific laminar patterns of the human LGN. These laminar patterns were highly reproducible with different pulse sequences scanned on separate days, between different subjects, and were in remarkable consistency with the simulation from high-resolution histology of the human LGNs. These findings clearly demonstrate that 7T fMRI can robustly resolve layer-specific responses of the human LGN. This paves the way for future investigation of the critical roles of the LGN in human visual perception and cognition, as well as the neural mechanisms of many developmental and neurodegenerative diseases.
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- 2020
83. Editorial: Advances in Multi-Scale Analysis of Brain Complexity
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Christoph M. Michel, Danny J.J. Wang, Kay Jann, and Albert C. Yang
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medicine.diagnostic_test ,business.industry ,Computer science ,General Neuroscience ,brain ,multiscale (MS) modeling ,Electroencephalography ,Machine learning ,computer.software_genre ,fMRI — functional magnetic resonance imaging ,lcsh:RC321-571 ,Editorial ,Scale analysis (mathematics) ,medicine ,Artificial intelligence ,EEG ,business ,complexity ,computer ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,Neuroscience - Published
- 2020
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84. Human Placenta Blood Flow During Early Gestation With Pseudocontinuous Arterial Spin Labeling MRI
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Sherin U. Devaskar, Dapeng Liu, Alibek Danyalov, Danny J.J. Wang, Kyunghyun Sung, Carla Janzen, Xingfeng Shao, Teresa Chanlaw, and Rinat Masamed
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Wilcoxon signed-rank test ,Placenta ,Population ,Reproductive health and childbirth ,pseudocontinuous ASL ,Medical and Health Sciences ,Article ,placenta MRI ,Engineering ,Pregnancy ,Clinical Research ,Medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Placental Circulation ,Prospective Studies ,Stage (cooking) ,education ,Pediatric ,education.field_of_study ,screening and diagnosis ,business.industry ,Prevention ,Early gestation ,Blood flow ,medicine.disease ,Magnetic Resonance Imaging ,ischemic placental disease ,4.1 Discovery and preclinical testing of markers and technologies ,Detection ,Nuclear Medicine & Medical Imaging ,medicine.anatomical_structure ,Cerebrovascular Circulation ,Physical Sciences ,Gestation ,Biomedical Imaging ,Spin Labels ,Female ,perfusion MRI ,business ,Nuclear medicine - Abstract
BACKGROUND Noninvasive measurement of placental blood flow is the major technical challenge for predicting ischemic placenta (IPD). Pseudocontinuous arterial spin labeling (pCASL) MRI was recently shown to be promising, but the potential value in predicting the subsequence development of IPD is not known. PURPOSE To derive global and regional placental blood flow parameters from longitudinal measurements of pCASL MRI and to assess the associations between perfusion-related parameters and IPD. STUDY TYPE Prospective. POPULATION Eighty-four women completed two pCASL MRI scans (first; 14-18 weeks and second; 19-24 weeks) from prospectively recruited 118 subjects. A total of 69 subjects were included for the analysis, of which 15 subjects developed IPD. FIELD STRENGTH/SEQUENCE 3T/T2 -weighted half-Fourier single-shot turbo spin-echo (HASTE) and pCASL. ASSESSMENT Four perfusion-related parameters in the placenta were derived: placenta volume, placental blood flow (PBF), high PBF (hPBF), and relative hPBF. The longitudinal changes of the parameters and their association with IPD were tested after being normalizing to the 16th and 20th weeks of gestation. STATISTICAL TESTS Comparisons between two gestational ages within subjects were performed using the paired Wilcoxon tests, and comparisons between normal and IPD groups were performed using the unpaired Wilcoxon tests. RESULTS The difference between the first and second MRI scans was statistically significant for volume (156.6 cm3 vs. 269.7 cm3 , P
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- 2020
85. Layer-dependent multiplicative effects of spatial attention on contrast responses in human early visual cortex
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Danny J.J. Wang, Peng Zhang, Zihao Zhang, Sheng He, Chencan Qian, Kaibao Sun, Fanhua Guo, and Chengwen Liu
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0301 basic medicine ,Physics ,Brain Mapping ,General Neuroscience ,Middle layer ,media_common.quotation_subject ,Multiplicative function ,Magnetic Resonance Imaging ,03 medical and health sciences ,Neural activity ,030104 developmental biology ,0302 clinical medicine ,Visual cortex ,medicine.anatomical_structure ,Research Design ,Scaling effect ,Modulation (music) ,medicine ,Contrast (vision) ,Humans ,Neuroscience ,030217 neurology & neurosurgery ,Gradient echo ,media_common ,Visual Cortex - Abstract
Attention mechanisms at different cortical layers of human visual cortex remain poorly understood. Using submillimeter-resolution fMRI at 7T, we investigated the effects of top-down spatial attention on the contrast responses across different cortical depths in human early visual cortex. Gradient echo (GE) T2* weighted BOLD signal showed an additive effect of attention on contrast responses across cortical depths. Compared to the middle cortical depth, attention modulation was stronger in the superficial and deep depths of V1, and also stronger in the superficial depth of V2 and V3. Using ultra-high resolution (0.3mm in-plane) balanced steady-state free precession (bSSFP) fMRI, a multiplicative scaling effect of attention was found in the superficial and deep layers, but not in the middle layer of V1. Attention modulation of low contrast response was strongest in the middle cortical depths, indicating baseline enhancement or contrast gain of attention modulation on feedforward input. Finally, the additive effect of attention on T2* BOLD can be explained by strong nonlinearity of BOLD signals from large blood vessels, suggesting multiplicative effect of attention on neural activity. These findings support that top-down spatial attention mainly operates through feedback connections from higher order cortical areas, and a distinct mechanism of attention may also be associated with feedforward input through subcortical pathway.HighlightsResponse or activity gain of spatial attention in superficial and deep layersContrast gain or baseline shift of attention in V1 middle layerNonlinearity of large blood vessel causes additive effect of attention on T2* BOLD
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- 2020
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86. Deep Learning Detection of Penumbral Tissue on Arterial Spin Labeling in Stroke
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Fabien Scalzo, Danny J.J. Wang, Greg Zaharchuk, Yuan Xie, Qinyang Shou, Hosung Kim, Kai Wang, Samantha J. Ma, David S Liebeskind, Xin J Qiao, Jeffrey L. Saver, Yannan Yu, and Noriko Salamon
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Perfusion Imaging ,Clinical Sciences ,Perfusion scanning ,Bioengineering ,Cardiorespiratory Medicine and Haematology ,Article ,030218 nuclear medicine & medical imaging ,Brain Ischemia ,03 medical and health sciences ,0302 clinical medicine ,Deep Learning ,medicine ,Humans ,magnetic resonance imaging ,In patient ,Endovascular treatment ,Stroke ,Retrospective Studies ,Advanced and Specialized Nursing ,Neurology & Neurosurgery ,medicine.diagnostic_test ,business.industry ,Deep learning ,Neurosciences ,deep learning ,Magnetic resonance imaging ,medicine.disease ,arterial spin labeling ,stroke ,Brain Disorders ,Diffusion Magnetic Resonance Imaging ,Cerebrovascular Circulation ,Arterial spin labeling ,Biomedical Imaging ,Spin Labels ,Neurology (clinical) ,Artificial intelligence ,Cardiology and Cardiovascular Medicine ,business ,Nuclear medicine ,Perfusion ,030217 neurology & neurosurgery ,Magnetic Resonance Angiography - Abstract
Background and Purpose— Selection of patients with acute ischemic stroke for endovascular treatment generally relies on dynamic susceptibility contrast magnetic resonance imaging or computed tomography perfusion. Dynamic susceptibility contrast magnetic resonance imaging requires injection of contrast, whereas computed tomography perfusion requires high doses of ionizing radiation. The purpose of this work was to develop and evaluate a deep learning (DL)–based algorithm for assisting the selection of suitable patients with acute ischemic stroke for endovascular treatment based on 3-dimensional pseudo-continuous arterial spin labeling (pCASL). Methods— A total of 167 image sets of 3-dimensional pCASL data from 137 patients with acute ischemic stroke scanned on 1.5T and 3.0T Siemens MR systems were included for neural network training. The concurrently acquired dynamic susceptibility contrast magnetic resonance imaging was used to produce labels of hypoperfused brain regions, analyzed using commercial software. The DL and 6 machine learning (ML) algorithms were trained with 10-fold cross-validation. The eligibility for endovascular treatment was determined retrospectively based on the criteria of perfusion/diffusion mismatch in the DEFUSE 3 trial (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke). The trained DL algorithm was further applied on twelve 3-dimensional pCASL data sets acquired on 1.5T and 3T General Electric MR systems, without fine-tuning of parameters. Results— The DL algorithm can predict the dynamic susceptibility contrast–defined hypoperfusion region in pCASL with a voxel-wise area under the curve of 0.958, while the 6 ML algorithms ranged from 0.897 to 0.933. For retrospective determination for subject-level endovascular treatment eligibility, the DL algorithm achieved an accuracy of 92%, with a sensitivity of 0.89 and specificity of 0.95. When applied to the GE pCASL data, the DL algorithm achieved a voxel-wise area under the curve of 0.94 and a subject-level accuracy of 92% for endovascular treatment eligibility. Conclusions— pCASL perfusion magnetic resonance imaging in conjunction with the DL algorithm provides a promising approach for assisting decision-making for endovascular treatment in patients with acute ischemic stroke.
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- 2020
87. Advances in Multi-Scale Analysis of Brain Complexity
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Christoph M. Michel, Danny J.J. Wang, Albert C. Yang, and Kay Jann
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medicine.diagnostic_test ,Computer science ,business.industry ,Scale analysis (mathematics) ,medicine ,Artificial intelligence ,Electroencephalography ,Machine learning ,computer.software_genre ,business ,computer - Published
- 2020
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88. Lower retinal capillary density in minimal cognitive impairment among older Latinx adults
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Danny J.J. Wang, Hanzhang Lu, Kay Jann, Samantha J. Ma, Amir H. Kashani, Lina M. D'Orazio, John M. Ringman, Bright S. Ashimatey, and Xuejuan Jiang
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Retinal Imaging ,retina ,medicine.medical_specialty ,Clinical Dementia Rating ,lcsh:Geriatrics ,lcsh:RC346-429 ,capillary ,cerebrovascular reactivity ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,medicine.artery ,Internal medicine ,Fazekas scale ,Medicine ,Dementia ,Cognitive decline ,lcsh:Neurology. Diseases of the nervous system ,030304 developmental biology ,0303 health sciences ,medicine.diagnostic_test ,business.industry ,white matter hyperintensity ,Montreal Cognitive Assessment ,Magnetic resonance imaging ,Retinal ,vascular cognitive impairment and dementia (VCID) ,medicine.disease ,lcsh:RC952-954.6 ,Psychiatry and Mental health ,chemistry ,Middle cerebral artery ,optical coherence tomography angiography (OCTA) ,Cardiology ,clinical dementia rating (CDR) ,Neurology (clinical) ,Montreal Cognitive Assessment (MoCA) ,business ,Perfusion ,030217 neurology & neurosurgery ,Research Article - Abstract
Introduction We investigated the hypothesis that retinal capillary perfusion is a biomarker of early cognitive decline and cerebrovascular perfusion associated with small vessel disease in a pilot data set of Latinx adults at high risk for vascular cognitive impairment and dementia. Methods High‐resolution optical coherence tomography angiography (OCTA) images were acquired from dilated eyes of Latinx subjects using a 3 × 3 mm2 scan pattern from a commercially available device. A previously validated method was used to quantify the density of perfused retinal capillaries as the retinal vessel skeleton density (VSD). The association of VSD with Clinical Dementia Rating Sum of Boxes, total Montreal Cognitive Assessment (MoCA) score, and individual MoCA test elements were analyzed using multivariate statistics that adjusted for confounders. VSD was also compared with magnetic resonance imaging (MRI) measures of cerebrovascular reactivity (CVR) and perfusion in the middle cerebral artery perforator (MCA‐Perf) territory. Results The mean (± SD) age of the subjects was 68 (± 6) years. For every 0.01‐unit lower VSD, the risk of having a CDR‐SOB >0 was 20% higher (95%CI = 5%–90%; P = .031). Similarly, a lower VSD was associated with lower total MoCA score (r = 0.3; P = .038). The Visuospatial/Executive domain of the MoCA assessment showed the strongest association with VSD (β = 0.02; P = .022). Lower retinal VSD was associated with worse MRI measure of CVR (r = 0.7, P = .04) and less perfusion in the MCA‐Perf territory (r = 0.45, P = .02). Discussion Impaired retinal capillary perfusion is associated with cognitive impairment and abnormalities in cerebrovascular perfusion and function. OCTA‐based retinal capillary assessment holds promise for identifying and quantifying retinal correlates of neurovascular abnormalities associated with vascular cognitive impairment.
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- 2020
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89. Synergistically enhanced interface stability by graphene assisted copper surface reconstruction
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K.M. Yang, Q. Li, Q. Zhang, G.S. Liu, J.J. Wang, Y.F. Yang, C.X. Guo, J.M. Ni, J. Song, J. Zhang, Y. Liu, and T.X. Fan
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Polymers and Plastics ,Metals and Alloys ,Ceramics and Composites ,Electronic, Optical and Magnetic Materials - Published
- 2022
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90. Mapping water exchange across the blood-brain barrier using 3D diffusion-prepared arterial spin labeled perfusion MRI
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Samantha J. Ma, Danny J.J. Wang, Lina M. D'Orazio, Xingfeng Shao, John M. Ringman, and Marlene Casey
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Adult ,Male ,Materials science ,Clinical Dementia Rating ,Intraclass correlation ,Permeability ,Article ,030218 nuclear medicine & medical imaging ,Cohort Studies ,Diffusion ,White matter ,Young Adult ,03 medical and health sciences ,Imaging, Three-Dimensional ,0302 clinical medicine ,Nuclear magnetic resonance ,Risk Factors ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Diffusion (business) ,Aged ,Reproducibility ,Brain ,Reproducibility of Results ,Pulse sequence ,Middle Aged ,Mental Status and Dementia Tests ,Magnetic Resonance Imaging ,White Matter ,Healthy Volunteers ,medicine.anatomical_structure ,Blood-Brain Barrier ,Cerebral Small Vessel Diseases ,Spin echo ,Dementia ,Female ,Spin Labels ,Perfusion ,030217 neurology & neurosurgery - Abstract
Purpose To present a novel MR pulse sequence and modeling algorithm to quantify the water exchange rate (kw ) across the blood-brain barrier (BBB) without contrast, and to evaluate its clinical utility in a cohort of elderly subjects at risk of cerebral small vessel disease (SVD). Methods A diffusion preparation module with spoiling of non-Carr-Purcell-Meiboom-Gill signals was integrated with pseudo-continuous arterial spin labeling (pCASL) and 3D gradient and spin echo (GRASE) readout. The tissue/capillary fraction of the arterial spin labeling (ASL) signal was separated by appropriate diffusion weighting (b = 50 s/mm2 ). kw was quantified using a single-pass approximation (SPA) model with total generalized variation (TGV) regularization. Nineteen elderly subjects were recruited and underwent 2 MRIs to evaluate the reproducibility of the proposed technique. Correlation analysis was performed between kw and vascular risk factors, Clinical Dementia Rating (CDR) scale, neurocognitive assessments, and white matter hyperintensity (WMH). Results The capillary/tissue fraction of ASL signal can be reliably differentiated with the diffusion weighting of b = 50 s/mm2 , given ~100-fold difference between the (pseudo-)diffusion coefficients of the 2 compartments. Good reproducibility of kw measurements (intraclass correlation coefficient = 0.75) was achieved. Average kw was 105.0 ± 20.6, 109.6 ± 18.9, and 94.1 ± 19.6 min-1 for whole brain, gray and white matter. kw was increased by 28.2%/19.5% in subjects with diabetes/hypercholesterolemia. Significant correlations between kw and vascular risk factors, CDR, executive/memory function, and the Fazekas scale of WMH were observed. Conclusion A diffusion prepared 3D GRASE pCASL sequence with TGV regularized SPA modeling was proposed to measure BBB water permeability noninvasively with good reproducibility. kw may serve as an imaging marker of cerebral SVD and associated cognitive impairment.
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- 2018
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91. Detection of N-glycolylneuraminic acid biomarkers in sera from patients with ovarian cancer using an engineered N-glycolylneuraminic acid-specific lectin SubB2M
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James C. Paton, Christopher J. Day, Michael P. Jennings, Lucy K. Shewell, J.J. Wang, and Adrienne W. Paton
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0301 basic medicine ,Glycan ,Biophysics ,Context (language use) ,Disease ,Protein Engineering ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,N-Glycolylneuraminic acid ,Lectins ,Biomarkers, Tumor ,Humans ,Medicine ,Molecular Biology ,Neoplasm Staging ,Ovarian Neoplasms ,biology ,business.industry ,Lectin ,Cell Biology ,Surface Plasmon Resonance ,medicine.disease ,carbohydrates (lipids) ,030104 developmental biology ,chemistry ,CA-125 Antigen ,030220 oncology & carcinogenesis ,biology.protein ,Cancer research ,Biomarker (medicine) ,Female ,Neuraminic Acids ,Cancer biomarkers ,business ,Ovarian cancer - Abstract
N-glycolylneuraminic acid (Neu5Gc)-containing glycans are a prominent form of aberrant glycosylation found in human tumor cells and have been proposed as cancer biomarkers. The B subunit of the subtilase cytotoxin (SubB) produced by Shiga toxigenic Escherichia coli recognises Neu5Gc containing glycans. We have previously engineered this lectin, SubB2M, for greater specificity and enhanced recognition of Neu5Gc-containing glycans. Here we further explore the utility of SubB2M to detect Neu5Gc tumor biomarkers in sera from patients with ovarian cancer. Using surface plasmon resonance (SPR) we show that SubB2M can detect the established ovarian cancer biomarker, CA125, in a highly sensitive and specific fashion in the context of human serum. These studies established conditions for screening serum samples from patients with ovarian cancer for Neu5Gc glycans. We found that serum from patients with all stages of ovarian cancer had significantly elevated mean levels of Neu5Gc glycans compared to normal controls. Serum from patients with late stage disease (stages IIIC, IV) had uniformly elevated levels of Neu5Gc glycans. Detection of Neu5Gc-glycans using SubB2M has the potential to be used as a diagnostic ovarian cancer biomarker, as well as a tool for monitoring treatment and disease progression in late stage disease.
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- 2018
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92. Hypercapnia increases brain viscoelasticity
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Sebastian Hirsch, Ingolf Sack, Florian Dittmann, Axel Lipp, Stefan Hetzer, Karl Bormann, Danny J.J. Wang, and Jürgen Braun
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Adult ,Male ,medicine.medical_specialty ,Vasodilation ,Viscoelasticity ,Hypercapnia ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Humans ,Gray Matter ,Elasticity (economics) ,Brain function ,Intracranial pressure ,Viscosity ,business.industry ,Models, Cardiovascular ,Original Articles ,Elasticity ,Neurology ,Cerebral blood flow ,Cerebrovascular Circulation ,Cardiology ,Elasticity Imaging Techniques ,Neurology (clinical) ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business ,Perfusion ,030217 neurology & neurosurgery ,circulatory and respiratory physiology - Abstract
Brain function, the brain’s metabolic activity, cerebral blood flow (CBF), and intracranial pressure are intimately linked within the tightly autoregulated regime of intracranial physiology in which the role of tissue viscoelasticity remains elusive. We applied multifrequency magnetic resonance elastography (MRE) paired with CBF measurements in 14 healthy subjects exposed to 5-min carbon dioxide-enriched breathing air to induce cerebral vasodilatation by hypercapnia. Stiffness and viscosity as quantified by the magnitude and phase angle of the complex shear modulus, | G*| and ϕ, as well as CBF of the whole brain and 25 gray matter sub-regions were analyzed prior to, during, and after hypercapnia. In all subjects, whole-brain stiffness and viscosity increased due to hypercapnia by 3.3 ± 1.9% and 2.0 ± 1.1% which was accompanied by a CBF increase of 36 ± 15%. Post-hypercapnia, | G*| and ϕ reduced to normal values while CBF decreased by 13 ± 15% below baseline. Hypercapnia-induced viscosity changes correlated with CBF changes, whereas stiffness changes did not. The MRE-measured viscosity changes correlated with blood viscosity changes predicted by the Fåhræus–Lindqvist model and microvessel diameter changes from the literature. Our results suggest that brain viscoelastic properties are influenced by microvessel blood flow and blood viscosity: vasodilatation and increased blood viscosity due to hypercapnia result in an increase in MRE values related to viscosity.
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- 2018
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93. trans-10,cis-12 conjugated linoleic acid alters lipid metabolism of goat mammary epithelial cells by regulation of de novo synthesis and the AMPK signaling pathway
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Zhi Chen, Huibin Tian, H.P. Shi, Jiangtao Huang, Jun Luo, Yue Ma, Tianying Zhang, and J.J. Wang
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0301 basic medicine ,Cell signaling ,Conjugated linoleic acid ,AMP-Activated Protein Kinases ,03 medical and health sciences ,chemistry.chemical_compound ,Mammary Glands, Animal ,Downregulation and upregulation ,Genetics ,Animals ,Lactation ,Linoleic Acids, Conjugated ,Protein kinase A ,Fatty acid synthesis ,Goats ,Fatty Acids ,0402 animal and dairy science ,RNA ,Epithelial Cells ,Lipid metabolism ,04 agricultural and veterinary sciences ,Lipid Metabolism ,040201 dairy & animal science ,Milk ,030104 developmental biology ,chemistry ,Biochemistry ,Female ,Animal Science and Zoology ,Signal transduction ,Food Science - Abstract
The trans-10,cis-12 isomer of conjugated linoleic acid (t10c12-CLA) is a biohydrogenation intermediate in the rumen and has been shown to cause milk fat depression in dairy goats. However, few studies have focused on the in vitro molecular mechanisms involved in the response of the goat mammary gland to t10c12-CLA. In the present study, RNA sequencing technology was used to investigate the effects of t10c12-CLA on goat mammary epithelial cells. From the data, 25,153 annotated transcripts were obtained, and differentially expressed genes were selected based on a false discovery rate
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- 2018
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94. Implications of evidence-based understanding of benefits and risks for cancer prevention strategy
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Harry H.X. Wang and J.J. Wang
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medicine.medical_specialty ,Cancer prevention ,Evidence-based practice ,medicine.diagnostic_test ,business.industry ,MEDLINE ,Retrospective cohort study ,medicine.anatomical_structure ,Prostate ,Biopsy ,medicine ,Ultrasonography ,Risk assessment ,business ,Intensive care medicine - Published
- 2019
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95. Microstructure and optical properties of AgCuAl medium entropy films with nanoparticles induced by pulsed-laser dewetting
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J.J. Wang, Hsiung Chou, W. S. Chuang, W.H. Lu, J.C. Huang, H.K. Lin, and Chih-Yen Chen
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Materials science ,Analytical chemistry ,Nanoparticle ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,Substrate (electronics) ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Sputtering ,Materials Chemistry ,Dewetting ,Thin film ,Surface plasmon resonance ,0210 nano-technology ,Absorption (electromagnetic radiation) - Abstract
AgCuAl equimolar complex concentrated alloy (CCA) thin films are deposited on glass substrates using a high-vacuum sputtering system. The films are annealed at 400 °C for 5 min to stabilize the structure and are then dewetted using a NIR pulsed-laser system at various pulse powers, repetition rates and scan speeds to form nanoparticles. It is shown that the dewetting process prompts a diffusion of the Al atoms toward the glass substrate. The resulting low concentration of Al within the AgCuAl film results in the formation of CCA nanoparticles consisting mainly of Ag and Cu with neither elemental segregation nor phase separation. The nanoparticles exhibit local surface plasmon resonance (LSPR) peaks at wavelengths in the range of 510–550 nm. The nanoparticle size and peak wavelength vary linearly with the accumulated energy density, which is controllable through the dewetting parameters. Overall, the present results suggest that AgCuAl CCA thin films have significant potential for such applications as tuning the absorption wavelength peak.
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- 2021
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96. Noncontrast-enhanced time-resolved 4D dynamic intracranial MR angiography at 7T: A feasibility study
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Danny J.J. Wang, Yan Zhang, Xianchang Zhang, Fei Cong, Xinyuan Miao, Songlin Yu, Hee Kwon Song, Jing An, Shuo Wang, Yong Cao, Lirong Yan, and Yan Zhuo
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Image quality ,business.industry ,Study Type ,Mr angiography ,Arteriovenous malformation ,Radial trajectory ,medicine.disease ,eye diseases ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Cohen's kappa ,Arterial spin labeling ,cardiovascular system ,Medicine ,Radiology, Nuclear Medicine and imaging ,cardiovascular diseases ,Golden angle ,business ,Nuclear medicine ,030217 neurology & neurosurgery - Abstract
Background Arterial spin labeling (ASL) based-noncontrast-enhanced 4D MR angiography (NCE 4D MRA) shows potential in characterizing cerebrovascular hemodynamics in cerebrovascular disorders. Ultrahigh-field theoretically benefits ASL signal with increased inherent signal-to-noise ratio (SNR) and prolonged blood T1 , which may provide improved delineation of vasculature in 4D MRA. Purpose To investigate the feasibility of NCE 4D MRA using 3D Cartesian trajectory and stack-of-stars (SOS) golden angle radial trajectory at 7T. Study type A prospective study. Subjects Six normal volunteers and eight patients with arteriovenous malformation (AVM). Field strength/sequence NCE 4D MRA with Cartesian and radial trajectories were performed at 3T and 7T. Assessment Subjective image quality of 4D MRA was evaluated using a 4-point scale by two experienced neuroradiologists. The characterization of AVM components with 4D MRA and DSA was also graded using the Spetzler-Martin grading scale. Statistical tests Cohen's kappa coefficient was calculated to evaluate the agreement between two readers within each 4D MRA technique (Cartesian and Radial). A Wilcoxon signed-rank test was performed to compare the subjective image quality scores of 4D MRA between Cartesian and radial trajectories, and between 7T and 3T, respectively. Results Good-to-excellent image quality was achieved in 4D MRA with both Cartesian (3.83 ± 0.41) and radial (3.42 ± 0.49) acquisitions in healthy volunteers at 7T. However, markedly reduced scan time was needed with radial acquisition. 4D MRA at 7T (3.31 ± 0.59) shows better delineation of AVM lesion features, especially the vein drainage, compared with that of 3T (2.83 ± 0.75), although no statistical significance was achieved (P = 0.180). Data conclusion The feasibility of ASL based 4D MRA at 7T with Cartesian and SOS golden angle radial acquisition was demonstrated. The clinical evaluation of 4D MRA in AVMs between 3T and 7T suggested 7T 4D MRA images acquired with radial acquisition demonstrate excellent delineation of AVM features, especially the draining veins. Level of evidence 2 Technical Efficacy Stage 2 J. Magn. Reson. Imaging 2017.
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- 2017
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97. Low-dose CT perfusion with projection view sharing
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Jeff R. Alger, Thomas Martin, Danny J.J. Wang, Michael F. McNitt-Gray, and John M. Hoffman
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Radon transform ,business.industry ,Perfusion Imaging ,Reconstruction algorithm ,Perfusion scanning ,General Medicine ,Radiation Dosage ,Article ,Imaging phantom ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Undersampling ,Dynamic contrast-enhanced MRI ,Image Processing, Computer-Assisted ,Tomography, X-Ray Computed ,Nuclear medicine ,business ,Projection (set theory) ,030217 neurology & neurosurgery ,Projection View ,Mathematics - Abstract
Author(s): Martin, Thomas; Hoffman, John; Alger, Jeff R; McNitt-Gray, Michael; Wang, Danny Jj | Abstract: PurposeCT Perfusion (CTP) is a widely used clinical imaging modality. However, CTP typically involves the use of substantial radiation dose (CTDIvol ≥~200 mGy). The purpose of this study is to present a low-dose CTP technique using a projection view-sharing reconstruction algorithm originally developed for dynamic MRI - "K-space Weighted Image Contrast" (KWIC).MethodsThe KWIC reconstruction is based on an angle-bisection scheme. In KWIC, a Fourier transform was performed along each projection to form a "k-space"-like CT data space, based on the central-slice theorem. As a projection view-sharing technique, KWIC preserves the spatiotemporal resolution of undersampled CTP data by progressively increasing the number of projection views shared for more distant regions of "k-space". KWIC reconstruction was evaluated on a digital FORBILD head phantom with numerically simulated time-varying objects. The numerically simulated scans were undersampled using the angle-bisection scheme to achieve 50%, 25%, and 12.5% of the original dose (288, 144, and 72 projections, respectively). The area-under-the-curve (AUC), time-to-peak (TTP), and full width half maximum (FWHM) were measured in KWIC recons and compared to fully sampled filtered back projection (FBP) reconstructions. KWIC reconstruction and dose reduction was also implemented for three clinical CTP cases (45 s, 1156 projections per turn, 1 s/turn, CTDIvol 217 mGy). Quantitative perfusion metrics were computed and compared between KWIC reconstructed CTP data and those of standard FBP reconstruction.ResultsThe AUC, TTP, and FWHM in the numerical simzulations were unaffected by the undersampling/dose reduction (down to 12.5% dose) with KWIC reconstruction compared to the fully sampled FBP reconstruction. The normalized root-mean-square-error (NRMSE) of the AUC in the FORBILD head phantom is 0.04, 0.05, and 0.07 for 50%, 25%, and 12.5% KWIC, respectively, as compared to FBP reconstruction. The cerebral blood flow (CBF) and cerebral blood volume had no significant difference between FBP and 50%, 25%, and 12.5% KWIC reconstructions (P g 0.05).ConclusionsThis study demonstrates that KWIC preserves perfusion metrics for CTP with substantially reduced dose. Clinical implementation will require further investigation into methods of rapid switching of a CT x-ray source.
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- 2017
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98. Fabrication of single crystal diamond microchannels for micro-electromechanical systems
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Wei Wang, Wang Yanfeng, Hong-Xing Wang, Dan Zhao, Garuma Abdisa Denu, Xiaohui Chang, G.Q. Shao, Fengnan Li, Tianfei Zhu, Jiao Fu, J.J. Wang, Zongchen Liu, Xun Hou, Minghui Zhang, Jingwen Zhang, and Xiaofan Zhang
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010302 applied physics ,Microchannel ,Fabrication ,Materials science ,Scanning electron microscope ,Mechanical Engineering ,Nanotechnology ,02 engineering and technology ,General Chemistry ,Sputter deposition ,021001 nanoscience & nanotechnology ,Epitaxy ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,law.invention ,Tungsten film ,Optical microscope ,law ,0103 physical sciences ,Materials Chemistry ,Electrical and Electronic Engineering ,0210 nano-technology ,Layer (electronics) - Abstract
Fabrication of single crystal diamond microchannels on HPHT diamond substrate has been carried out successfully. Firstly, tungsten film was patterned on diamond substrate surface by conventional photolithography and magnetron sputtering methods. Secondly, single crystal diamond epitaxial layer was grown on the surface of the patterned substrate by microwave plasma chemical vapor deposition system. Then the tungsten film was etched out by acid to form microchannel. Finally, different color liquid was introduced to check the hollow of microchannels. The morphology of the microchannels has been investigated by optical microscope, scanning electron microscope and atomic force microscope. The crystallinity was evaluated by X-ray diffraction systems and Raman spectroscope technology.
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- 2017
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99. Collateral perfusion using arterial spin labeling in symptomatic versus asymptomatic middle cerebral artery stenosis
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Jinhao Lyu, Xin Lou, Lin Ma, David S Liebeskind, Xiaoxiao Ma, Chenglin Tian, Danny J.J. Wang, Xiaojing Long, and Ning Ma
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Male ,Middle Cerebral Artery ,medicine.medical_specialty ,Collateral Circulation ,Neuroimaging ,Constriction, Pathologic ,Asymptomatic ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,medicine.artery ,Middle cerebral artery stenosis ,Internal medicine ,medicine ,Humans ,Prospective Studies ,Aged ,business.industry ,Angiography, Digital Subtraction ,Original Articles ,Middle Aged ,medicine.disease ,Collateral circulation ,Magnetic Resonance Imaging ,Stenosis ,Neurology ,Cerebral blood flow ,Cerebrovascular Circulation ,Middle cerebral artery ,Arterial spin labeling ,cardiovascular system ,Cardiology ,Female ,Spin Labels ,Neurology (clinical) ,Radiology ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business ,Perfusion ,030217 neurology & neurosurgery ,circulatory and respiratory physiology - Abstract
The purpose was to assess the difference of collaterals in symptomatic versus asymptomatic patients with unilateral middle cerebral artery (MCA) stenosis by comparing cerebral blood flow (CBF) at two post labeling delays (PLD) using three-dimensional pseudo-continuous arterial spin labeling (3D pCASL). Eighty-one patients (49 symptomatic and 32 asymptomatic) with unilateral MCA stenosis ≥50% who underwent pCASL with two PLDs were included. Mean CBF and CBF subtraction images between two PLDs of MCA territories were compared in symptomatic and asymptomatic groups, respectively. Compared with the asymptomatic group, patients with symptomatic MCA stenosis had significantly lower CBF in the MCA territory of stenotic side at each PLD. The CBF of stenotic territory showed greater increase than that of normal side from PLD 1.5 to 2.5 s. The CBF of asymptomatic MCA territory increased similarly with that of symptomatic MCA territory from PLD of 1.5 to 2.5 s in stenotic side, while symptomatic patients experienced significantly slower antegrade flow. On CBF subtraction images, asymptomatic patients showed larger volume of differences between PLD of 1.5 and 2.5 s compared with those of symptomatic patients ( p = 0.037). The results suggest that more robust collateral perfusion on two-delay 3D pCASL is present in asymptomatic patients compared with symptomatic patients.
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- 2017
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100. Reduced regional cerebral blood flow in patients with heart failure
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Danny J.J. Wang, Gregg C. Fonarow, Mary A. Woo, Ronald M. Harper, Rajesh Kumar, and Bhaswati Roy
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Cardiac output ,medicine.diagnostic_test ,business.industry ,Thalamus ,Magnetic resonance imaging ,030204 cardiovascular system & hematology ,Corpus callosum ,medicine.disease ,White matter ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,nervous system ,Cerebral blood flow ,Neuroimaging ,Heart failure ,Anesthesia ,medicine ,Cardiology and Cardiovascular Medicine ,business ,030217 neurology & neurosurgery - Abstract
Aims Heart failure (HF) patients show significant lateralized neural injury, accompanied by autonomic, mood and cognitive deficits. Both gray and white matter damage occurs and probably develops from altered cerebral blood flow (CBF), a consequence of impaired cardiac output. However, the distribution of regional CBF changes in HF patients is unknown, but is an issue in determining mechanisms of neural injury. Our aim was to compare regional CBF changes in HF with CBF in control subjects using non-invasive pseudo-continuous arterial spin labelling (ASL) procedures. Methods and results We collected pseudo-continuous ASL data from 19 HF patients [mean age 55.5 ± 9.1 years; mean body mass index 27.7 ± 5.3 kg/m2; 13 male) and 29 control subjects (mean age 51.4 ± 5.3 years; mean body mass index 25.7 ± 3.6 kg/m2; 18 male), using a 3.0-Tesla magnetic resonance imaging (MRI) scanner. Whole-brain CBF maps were calculated, normalized to a common space, smoothed and compared between groups using ANCOVA (covariates; age, gender and gray matter volume). Reduced CBF appeared in multiple sites in HF patients in comparison with controls, with principally lateralized lower flow in temporal, parietal and occipital regions. Areas with decreased CBF included the bilateral prefrontal, frontal, temporal and occipital cortex, thalamus, cerebellum, corona radiate, corpus callosum, hippocampus and amygdala. Conclusions Heart failure patients showed lower, and largely lateralized, CBF in multiple autonomic, mood and cognitive regulatory sites. The reduced CBF is likely to contribute to the lateralized brain injury, leading to the autonomic and neuropsychological deficits found in the condition.
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- 2017
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