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https://www.readbyqxmd.com/read/29151545/-novel-perfusion-evaluation-method-using-phase-ratio-image-map-in-head-4d-ct
#1
Tomomi Ohmura, Yongbum Lee, Noriyuki Takahashi, Hideto Toyoshima
PURPOSE: CT perfusion (CTP) is a powerful tool for the assessment of cerebrovascular disease. However, CTP maps are significantly different depending on CTP software and algorithm, even when using identical image data. We developed a phase-ratio image map (PI map), which was a novel perfusion map, without using CTP software. The purpose of this study was to investigate the usefulness of the PI map by comparing it with a positron emission tomography (PET) image. METHODS: Twenty patients (16 men, 4 women; mean age: 61...
2017: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/29151217/covariance-nmr-processing-and-analysis-for-protein-assignment
#2
Bradley J Harden, Dominique P Frueh
During NMR resonance assignment it is often necessary to relate nuclei to one another indirectly, through their common correlations to other nuclei. Covariance NMR has emerged as a powerful technique to correlate such nuclei without relying on error-prone peak peaking. However, false-positive artifacts in covariance spectra have impeded a general application to proteins. We recently introduced pre- and postprocessing steps to reduce the prevalence of artifacts in covariance spectra, allowing for the calculation of a variety of 4D covariance maps obtained from diverse combinations of pairs of 3D spectra, and we have employed them to assign backbone and sidechain resonances in two large and challenging proteins...
2018: Methods in Molecular Biology
https://www.readbyqxmd.com/read/29151181/screening-hcv-genotype-specific-epitope-peptides-based-on-conserved-sequence-analysis-and-b-cell-epitope-prediction-in-hcv-e2-region
#3
Rui Hua, Xiaoyu Jiang, Lingxia Qi, Shanshan Guan, Ziyu Kuai, Yongbo Qiao, Yan Xu, Xin Gong, Yuhua Shi, Wei Kong, Junqi Niu, Hao Zhang, Yaming Shan
The high mutation rate of the hepatitis C virus (HCV) genome increases the genotype diversity and renders the detection of the virus more difficult. Therefore, prediction and assessment of highly conserved and strongly antigenic epitope polypeptide sequences have become a focus of current research. The E2 region is the target binding region of neutralizing antibodies. HCV genomics, especially the high mutation rate of E2 region sequence, makes its genotyping more and more diverse, and the detection of HCV and genotype is becoming more and more strict...
November 18, 2017: Immunologic Research
https://www.readbyqxmd.com/read/29148430/low-dose-4d-cardiac-imaging-in-small-animals-using-dual-source-micro-ct
#4
Matthew Holbrook, Darin P Clark, Cristian T Badea
Micro-CT is widely used in preclinical studies, generating substantial interest in extending its capabilities in functional imaging applications such as blood perfusion and cardiac function. However, imaging cardiac structure and function in mice is challenging due to their small size and rapid heart rate. To overcome these challenges, we propose and compare improvements on two strategies for cardiac gating in dual-source, preclinical micro-CT: fast prospective gating (PG) and uncorrelated retrospective gating (RG)...
November 17, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29143523/new-insights-into-electronic-structure-and-photoelectrochemical-property-of-nitrogen-doped-hnb3o8-behaviors-via-a-combined-in-situ-experimental-with-dft-investigation
#5
Xiaobin Liu, Zhenyu Wang, Peng Chen, Huanfu Zhou, Ling Bing Kong, Chunming Niu, Wenxiu Que
Nitrogen-doping approach has been intensively adopted to improve the various properties of metal oxides-especially for adjusting energy band structure and extending photo-response range of oxide photocatalyst. However, nitrogen doped behavior is still unintelligible and complex due to the diversity of the compositions and crystal structures. In this work, new insights into electronic structure and photoelectrochemical property of nitrogen-doping HNb3O8 behaviors were presented. On the one hand, we utilized an in-situ experimental strategy to ascertain the effect of nitrogen-doping on the energy band and photoelectrochemical (PEC) property of HNb3O8 and nitrogen-doped HNb3O8 (N-HNb3O8)...
November 16, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29142240/robust-segmentation-of-the-full-cerebral-vasculature-in-4d-ct-of-suspected-stroke-patients
#6
Midas Meijs, Ajay Patel, Sil C van de Leemput, Mathias Prokop, Ewoud J van Dijk, Frank-Erik de Leeuw, Frederick J A Meijer, Bram van Ginneken, Rashindra Manniesing
A robust method is presented for the segmentation of the full cerebral vasculature in 4-dimensional (4D) computed tomography (CT). The method consists of candidate vessel selection, feature extraction, random forest classification and postprocessing. Image features include among others the weighted temporal variance image and parameters, including entropy, of an intensity histogram in a local region at different scales. These histogram parameters revealed to be a strong feature in the detection of vessels regardless of shape and size...
November 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29142154/the-choroid-plexus-of-the-lateral-ventricle-as-the-origin-of-csf-pulsation-is-questionable
#7
Ken Takizawa, Mitsunori Matsumae, Naokazu Hayashi, Akihiro Hirayama, Fumiya Sano, Satoshi Yatsushiro, Kagayaki Kuroda
The advent of magnetic resonance imaging (MRI) enables noninvasive measurement of cerebrospinal fluid (CSF) motion, and new information about CSF motion has now been acquired. The driving force of the CSF has long been thought to be choroid plexus (CP) pulsation, but to investigate whether this phenomenon actually occurs, CSF motion was observed in the ventricular system and subarachnoid space using MRI. Eleven healthy volunteers, ranging in age from 23 to 58 years, participated in this study. The MRI sequences used were four-dimensional phase-contrast (4D-PC) and time-spatial labeling inversion pulse (t-SLIP)...
November 16, 2017: Neurologia Medico-chirurgica
https://www.readbyqxmd.com/read/29140316/hybrid-system-for-in-vivo-epifluorescence-and-4d-optoacoustic-imaging
#8
Zhenyue Chen, Xosé Luis Deán-Ben, Sven Gottschalk, Daniel Razansky
Epifluorescence imaging is widely used in cell and molecular biology due to its excellent sensitivity, contrast, and ease of implementation. Optoacoustic imaging has been shown to deliver a highly complementary and unique set of capabilities for biological discovery, such as high spatial resolution in noninvasive deep tissue observations, fast volumetric imaging capacity, and spectrally enriched contrast. In this Letter, we report on a hybrid system combining planar fluorescence and real-time volumetric four-dimensional optoacoustic imaging by means of a fiberscope integrated within a handheld hemispherical ultrasound detection array...
November 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/29139646/physical-fitness-and-digit-ratio-2d-4d-in-male-students-from-wroc%C3%A5-aw-poland
#9
Slawomir Koziel, Marek Kociuba Mail, Raja Chakraborty, Zofia Ignasiak
There is sex-difference in humans as regards aerobic efficiency, physical strength and endurance and the sex difference is greatly dependent upon differential concentration of testosterone during different phases of growth and development including the intrauterine phase or prenatal growth. Second-to-fourth digit lengths ratio (2D:4D) is an putative indicator of prenatal testosterone exposure. Lower 2D:4D indicates higher prenatal testosterone exposure and vice versa. Males generally have lower 2D:4D than females...
March 2017: Collegium Antropologicum
https://www.readbyqxmd.com/read/29139645/finger-length-ratio-and-body-composition-in-chuvashians
#10
Leonid Kalichman, Valery Batsevich, Eugene Kobyliansky
Very few studies that evaluated the association between fi nger length ratio and body composition in adult population showed very diverse results. We carried out a radiographic study on a large population sample who had participated in a Chuvashian skeletal aging study investigating different aspects of skeletal aging. The aims of this study were to evaluate the association between 2D:4D ratio and various indices of body composition in Chuvashian males and females. The study sample included 802 males (mean age 46...
March 2017: Collegium Antropologicum
https://www.readbyqxmd.com/read/29136282/principal-component-reconstruction-pcr-for-cine-cbct-with-motion-learning-from-2d-fluoroscopy
#11
Hao Gao, Yawei Zhang, Lei Ren, Fang-Fang Yin
PURPOSE: This work aims to generate cine CT images (i.e., 4D images with high temporal resolution) based on a novel principal component reconstruction (PCR) technique with motion learning from 2D fluoroscopic training images. METHODS: In the proposed PCR method, the matrix factorization is utilized as an explicit low-rank regularization of 4D images that are represented as a product of spatial principal components and temporal motion coefficients. The key hypothesis of PCR is that temporal coefficients from 4D images can be reasonably approximated by temporal coefficients learned from 2D fluoroscopic training projections...
November 14, 2017: Medical Physics
https://www.readbyqxmd.com/read/29135461/site-occupancy-composition-and-magnetic-structure-dependencies-of-martensitic-transformation-in-mn-sub-2-sub-ni-sub-1-x-sub-sn-sub-1-x-sub
#12
Ashis Kundu, Subhradip Ghosh
A delicate balance between various factors such as site occupancy, composition and magnetic ordering seems to affect the stability of the martensitic phase in Mn<sub>2</sub>Ni<sub>1+x</sub>Sn<sub>1-x</sub>. Using first-principles DFT calculations, we explore the impacts of each one of these factors on the martensitic stability of this system. Our results on total energies, magnetic moments and electronic structures upon changes in the composition, the magnetic configurations and the site occupancies show that the occupancies at the 4d sites in the Inverse Heusler crystal structure play the most crucial role...
November 14, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/29134747/no-sex-difference-in-digit-ratios-2d-4d-in-the-traditional-yali-of-papua-and-its-meaning-for-the-previous-hypotheses-on-the-inter-populational-variability-in-2d-4d
#13
Michalina Marczak, Michał Misiak, Agnieszka Sorokowska, Piotr Sorokowski
OBJECTIVES: The ratio between the 2nd and 4th digit (2D:4D) is considered to be a sexually dimorphic trait in humans, with males having on average lower 2D:4D values than females. However, significant inter- and intra-sexual differences in digit ratios across populations have been reported. In order to further explore factors influencing the variability of 2D:4D, we performed a study among the Yali, a traditional population from Papua. METHODS: We measured digit ratios of 79 adults (47 males) from the traditional Yali society, a polygamous group who inhabit a harsh high-mountain environment almost directly on the equator...
November 14, 2017: American Journal of Human Biology: the Official Journal of the Human Biology Council
https://www.readbyqxmd.com/read/29134472/real-time-wireless-tumor-tracking-during-breast-conserving-surgery
#14
Natasja Janssen, Roeland Eppenga, Marie-Jeanne Vrancken Peeters, Frederieke van Duijnhoven, Hester Oldenburg, Jos van der Hage, Emiel Rutgers, Jan-Jakob Sonke, Koert Kuhlmann, Theo Ruers, Jasper Nijkamp
PURPOSE: To evaluate a novel surgical navigation system for breast conserving surgery (BCS), based on real-time tumor tracking using the Calypso[Formula: see text] 4D Localization System (Varian Medical Systems Inc., USA). Navigation-guided breast conserving surgery (Nav-BCS) was compared to conventional iodine seed-guided BCS ([Formula: see text]I-BCS). METHODS: Two breast phantom types were produced, containing spherical and complex tumors in which wireless transponders (Nav-BCS) or a iodine seed ([Formula: see text]I-BCS) were implanted...
November 13, 2017: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/29131445/airyscan-super-resolution-microscopy-of-mitochondrial-morphology-and-dynamics-in-living-tumor-cells
#15
Vladimir L Kolossov, Mayandi Sivaguru, Joseph Huff, Katherine Luby, Kaviamuthan Kanakaraju, H Rex Gaskins
Mitochondrial morphology is regulated by continuous fusion-and-fission events that are essential for maintaining normal function. Despite the prominence of mitochondrial function in energy generation and cell signaling, understanding of processes of fusion and fission dynamics has been hampered by the lack of high-resolution optical systems that accommodate live-cell imaging. We have examined different confocal modalities in terms of resolution and signal-to-noise ratio (SNR) in a point scanning confocal microscope with Airyscan super-resolution (AS-SR)...
November 13, 2017: Microscopy Research and Technique
https://www.readbyqxmd.com/read/29129056/computational-analysis-of-transition-metal-terminal-boride-complexes
#16
Yavuz Ceylan, Thomas R Cundari
A computational analysis of model transition-metal terminal boride [MB(PNP(R))] complexes is reported. A combination of density functional theory methods, natural bond orbital analysis, and multiconfiguration self-consistent field calculations were employed to investigate the structure and bonding of terminal boride complexes, in particular, the extent of metal dπ-boron pπ bonding. Comparison of metal-boride, -borylene, and-boryl bond lengths confirms the presence of metal-boron π bonds, albeit the modest shortening (∼3%) of the metal-boron bond suggests that the π-bonding is very weak in terminal borides...
November 13, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/29128122/resilience-of-carbon-and-nitrogen-removal-due-to-aeration-interruption-in-aerated-treatment-wetlands
#17
Johannes Boog, Jaime Nivala, Thomas Aubron, Sibylle Mothes, Manfred van Afferden, Roland A Müller
Treatment wetlands have long been used for domestic and industrial wastewater treatment. In recent decades, treatment wetland technology has evolved and now includes intensified designs such as aerated treatment wetlands. Aerated treatment wetlands are particularly dependent on aeration, which requires reliable air pumps and, in most cases, electricity. Whether aerated treatment wetlands are resilient to disturbances such as an aeration interruption is currently not well known. In order to investigate this knowledge gap, we carried out a pilot-scale experiment on one aerated horizontal flow wetland and one aerated vertical flow wetland under warm (Twater>17°C) and cold (Twater<10°C) weather conditions...
November 8, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29127775/four-dimensional-computed-tomography-evaluation-of-condylar-movement-in-a-patient-with-temporomandibular-joint-osteoarthritis
#18
Masaya Akashi, Takumi Hasegawa, Satoru Takahashi, Takahide Komori
Temporomandibular joint (TMJ) osteoarthritis (OA) is a disease of the bone, cartilage, and supporting tissues of the joint. Patients with advanced TMJ-OA often have symptoms such as pain, swelling, and joint dysfunction, and they sometimes require surgical intervention when conservative treatment is not effective. The etiology of TMJ-OA remains elusive. The usefulness of 4-dimensional (4D) computed tomography (CT) in motion analysis of various joints has recently been reported. This article introduces a novel imaging technique of 4D CT that aims to identify kinematic features that may be associated with the etiology of TMJ-OA...
October 16, 2017: Journal of Oral and Maxillofacial Surgery
https://www.readbyqxmd.com/read/29122361/ventilation-measured-on-clinical-4d-cbct-increased-ventilation-accuracy-through-improved-image-quality
#19
Kasper R Jensen, Carsten Brink, Olfred Hansen, Uffe Bernchou
BACKGROUND AND PURPOSE: Ventilation measured on 4D cone-beam computed tomography (CBCT) using deformable image registration (DIR) may predict specific radiation sensitivity, but the measurement is affected by the current image quality. With 4D computed tomography (CT) measured ventilation acting as a gold standard the current study investigates if image improvements increase the accuracy of 4D-CBCT measured ventilation. MATERIAL AND METHODS: The study consists of 4D-CBCT and 4D-CT scans of 20 non-small-cell lung cancer patients...
November 6, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/29121945/potential-dosimetric-benefits-of-adaptive-tumor-tracking-over-the-internal-target-volume-concept-for-stereotactic-body-radiation-therapy-of-pancreatic-cancer
#20
Konstantina Karava, Stefanie Ehrbar, Oliver Riesterer, Johannes Roesch, Stefan Glatz, Stephan Klöck, Matthias Guckenberger, Stephanie Tanadini-Lang
BACKGROUND: Radiotherapy for pancreatic cancer has two major challenges: (I) the tumor is adjacent to several critical organs and, (II) the mobility of both, the tumor and its surrounding organs at risk (OARs). A treatment planning study simulating stereotactic body radiation therapy (SBRT) for pancreatic tumors with both the internal target volume (ITV) concept and the tumor tracking approach was performed. The two respiratory motion-management techniques were compared in terms of doses to the target volume and organs at risk...
November 9, 2017: Radiation Oncology
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