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https://www.readbyqxmd.com/read/28722604/classification-and-visualization-of-physical-and-chemical-properties-of-falsified-medicines-with-handheld-raman-spectroscopy-and-x-ray-computed-tomography
#1
Tomoko Kakio, Naoko Yoshida, Susan Macha, Kazunobu Moriguchi, Takashi Hiroshima, Yukihiro Ikeda, Hirohito Tsuboi, Kazuko Kimura
Analytical methods for the detection of substandard and falsified medical products (SFs) are important for public health and patient safety. Research to understand how the physical and chemical properties of SFs can be most effectively applied to distinguish the SFs from authentic products has not yet been investigated enough. Here, we investigated the usefulness of two analytical methods, handheld Raman spectroscopy (handheld Raman) and X-ray computed tomography (X-ray CT), for detecting SFs among oral solid antihypertensive pharmaceutical products containing candesartan cilexetil as an active pharmaceutical ingredient (API)...
June 19, 2017: American Journal of Tropical Medicine and Hygiene
https://www.readbyqxmd.com/read/28714854/evaluation-of-bone-formation-in-calcium-phosphate-scaffolds-with-%C3%A2%C2%B5ct-method-validation-using-sem
#2
Susanne Lewin, Albert Barba, Cecilia Persson, Jordi Franch Serracanta, Maria Pau Ginebra, Caroline Öhman
There is a plethora of Calcium phosphate (CaP) scaffolds used as synthetic substitutes to bone grafts. The scaffold performance is often evaluated from the quantity of bone formed within or in direct contact with the scaffold. Micro computed tomography (µCT) allows three-dimensional evaluation of bone formation inside scaffolds. However, the almost identical x-ray attenuation of CaP and bone obtrude the separation of these phases in µCT images. Commonly, segmentation of bone in µCT images is based on gray scale intensity, with manually determined global thresholds...
July 17, 2017: Biomedical Materials
https://www.readbyqxmd.com/read/28713589/super-resolution-imaging-in-a-multiple-layer-epid
#3
Haijian Chen, Joerg Rottmann, Stephen Sf Yip, Daniel Morf, Rony Füglistaller, Josh Star-Lack, George Zentai, Ross Berbeco
A new portal imager consisting of four vertically stacked conventional electronic portal imaging device (EPID) layers has been constructed in pursuit of improved detective quantum efficiency (DQE). We hypothesize that super-resolution (SR) imaging can also be achieved in such a system by shifting each layer laterally by half a pixel relative to the layer above. Super-resolution imaging will improve resolution and contrast-to-noise ratio (CNR) in megavoltage (MV) planar and cone beam computed tomography (MV-CBCT) applications...
April 2017: Biomedical Physics & Engineering Express
https://www.readbyqxmd.com/read/28712710/%C3%A3-tcp-bone-substitutes-in-tibial-plateau-depression-fractures
#4
Tim Rolvien, Florian Barvencik, Till Orla Klatte, Björn Busse, Michael Hahn, Johannes Maria Rueger, Martin Rupprecht
BACKGROUND: The use of beta-tricalciumphospate (ß-TCP, Cerasorb®) ceramics as an alternative for autologous bone-grafting has been outlined previously, however with no study focusing on both clinical and histological outcomes of ß-TCP application in patients with multi-fragment tibial plateau fractures. The aim of this study was to analyze the long-term results of ß-TCP in patients with tibial plateau fractures. METHODS: 52 patients were included in this study...
July 13, 2017: Knee
https://www.readbyqxmd.com/read/28711189/effective-atomic-number-estimation-using-kv-mv-dual-energy-source-in-linac
#5
Dousatsu Sakata, Akihiro Haga, Satoshi Kida, Toshikazu Imae, Shigeharu Takenaka, Keiichi Nakagawa
Dual-energy computed tomography (DECT) imaging can measure the effective atomic number (EAN) as well as the electron density, and thus its adoption may improve dose calculations in brachytherapy and external photon/particle therapy. An expanded energy gap in dual-energy sources is expected to yield more accurate EAN estimations than conventional DECT systems, which typically span less than 100kV. The aim of this paper is to assess a larger energy gap DECT by using a linear accelerator (LINAC) radiotherapy system with a kV X-ray imaging device, which are combined to provide X-rays in both the kV- and MV-energy ranges...
July 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28710378/sub-nanometer-surface-chemistry-and-orbital-hybridization-in-lanthanum-doped-ceria-nano-catalysts-revealed-by-3d-electron-microscopy
#6
Sean M Collins, Susana Fernandez-Garcia, José J Calvino, Paul A Midgley
Surface chemical composition, electronic structure, and bonding characteristics determine catalytic activity but are not resolved for individual catalyst particles by conventional spectroscopy. In particular, the nano-scale three-dimensional distribution of aliovalent lanthanide dopants in ceria catalysts and their effect on the surface electronic structure remains unclear. Here, we reveal the surface segregation of dopant cations and oxygen vacancies and observe bonding changes in lanthanum-doped ceria catalyst particle aggregates with sub-nanometer precision using a new model-based spectroscopic tomography approach...
July 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28703119/dna-double-strand-break-dsb-induction-and-cell-survival-in-iodine-enhanced-computed-tomography-ct
#7
Seth W Streitmatter, Robert D Stewart, Peter A Jenkins, Tatjana Jevremovic
A multi-scale Monte Carlo model is proposed to assess the dosimetric and biological impact of iodine-based contrast agents commonly used in computed tomography. As presented, the model integrates the general purpose MCNP6 code system for larger-scale radiation transport and dose assessment with the Monte Carlo damage simulation to determine the sub-cellular characteristics and spatial distribution of initial DNA damage. The repair-misrepair-fixation model is then used to relate DNA double strand break (DSB) induction to reproductive cell death...
July 13, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28701043/in-situ-x-ray-tomography-study-of-cement-exposed-to-co2-saturated-brine
#8
Elvia Anabela Chavez Panduro, Malin Torsæter, Kamila Gawel, Ruben Bjørge, Alain Gibaud, Yi Yang, Stefan Bruns, Yi Zheng, Henning Osholm Sørensen, Dag W Breiby
For successful CO2 storage in underground reservoirs, the potential problem of CO2 leakage needs to be addressed. A profoundly improved understanding of the behavior of fractured cement under realistic subsurface conditions including elevated temperature, high pressure and the presence of CO2 saturated brine is required. Here, we report in-situ X-ray micro computed tomography (µ-CT) studies visualizing the micro-structural changes upon exposure of cured Portland cement with a leak path to CO2 saturated brine at high pressure...
July 12, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28699890/changes-of-mitochondrial-ultrastructure-and-function-during-ageing-in-mice-and-drosophila
#9
Tobias Brandt, Arnaud Mourier, Luke S Tain, Linda Partridge, Nils-Göran Larsson, Werner Kühlbrandt
Ageing is a progressive decline of intrinsic physiological functions. We examined the impact of ageing on the ultrastructure and function of mitochondria in mouse and fruit flies (Drosophila melanogaster) by electron cryo-tomography and respirometry and discovered distinct age-related changes in both model organisms. Mitochondrial function and ultrastructure are maintained in mouse heart, whereas subpopulations of mitochondria from mouse liver show age-related changes in membrane morphology. Subpopulations of mitochondria from young and old mouse kidney resemble those described for apoptosis...
July 12, 2017: ELife
https://www.readbyqxmd.com/read/28699622/atom-probe-tomographic-assessment-of-the-distribution-of-germanium-atoms-implanted-in-a-silicon-matrix-through-nano-apertures
#10
Yuan Tu, Bin Han, Yasuo Shimizu, Koji Inoue, Yuiko Fukui, Maasa Yano, Takashi Tanii, Takahiro Shinada, Yasuyoshi Nagai
Ion implantation through nanometer-scale apertures (nano-apertures) is a promising method to precisely position ions in silicon matrices, which is a requirement for next generation electronic and quantum computing devices. This paper reports the first-ever use of atom probe tomography (APT) to investigate the three-dimensional distribution of germanium atoms in silicon after implantation through nano-aperture of 10 nm in diameter, for evaluation of the amount and spatial distribution of implanted dopants. The experimental results obtained by APT are consistent with a simple simulation with consideration to several effects during lithography and ion implantation, such as channeling and resist flow...
July 12, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28689080/3d-reconstruction-of-the-magnetic-vector-potential-using-model-based-iterative-reconstruction
#11
K C Prabhat, K Aditya Mohan, Charudatta Phatak, Charles Bouman, Marc De Graef
Lorentz transmission electron microscopy (TEM) observations of magnetic nanoparticles contain information on the magnetic and electrostatic potentials. Vector field electron tomography (VFET) can be used to reconstruct electromagnetic potentials of the nanoparticles from their corresponding LTEM images. The VFET approach is based on the conventional filtered back projection approach to tomographic reconstructions and the availability of an incomplete set of measurements due to experimental limitations means that the reconstructed vector fields exhibit significant artifacts...
July 3, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/28689056/patient-navigation-for-lung-cancer-screening-in-an-urban-safety-net-system-protocol-for-a-pragmatic-randomized-clinical-trial
#12
David E Gerber, Heidi A Hamann, Noel O Santini, Suhny Abbara, Hsienchang Chiu, Molly McGuire, Lisa Quirk, Hong Zhu, Simon J Craddock Lee
The National Lung Screening Trial demonstrated improved lung cancer mortality with annual low-dose computed tomography (CT) screening, leading to lung cancer screening endorsement by the United States Preventive Services Task Force and coverage by the Centers for Medicare and Medicaid. Adherence to annual CT screens in that trial was 95%, which may not be representative of real-world, particularly medically underserved populations. This pragmatic trial will determine the effect of patient-focused, telephone-based patient navigation on adherence to CT-based lung cancer screening in an urban safety-net population...
July 5, 2017: Contemporary Clinical Trials
https://www.readbyqxmd.com/read/28686305/nanoscopic-analysis-of-oxygen-segregation-at-tilt-boundaries-in-silicon-ingots-using-atom-probe-tomography-combined-with-tem-and-ab-initio-calculations
#13
Y Ohno, K Inoue, K Fujiwara, K Kutsukake, M Deura, I Yonenaga, N Ebisawa, Y Shimizu, K Inoue, Y Nagai, H Yoshida, S Takeda, S Tanaka, M Kohyama
We have developed an analytical method to determine the segregation levels on the same tilt boundaries (TBs) at the same nanoscopic location by a joint use of atom probe tomography and scanning transmission electron microscopy, and discussed the mechanism of oxygen segregation at TBs in silicon ingots in terms of bond distortions around the TBs. The three-dimensional distribution of oxygen atoms was determined at the typical small- and large-angle TBs by atom probe tomography with a low impurity detection limit (0...
July 7, 2017: Journal of Microscopy
https://www.readbyqxmd.com/read/28686286/3-d-microstructure-of-olivine-in-complex-geological-materials-reconstructed-by-correlative-x-ray-%C3%AE-ct-and-ebsd-analyses
#14
W-A Kahl, N Dilissen, K Hidas, C J Garrido, V López-Sánchez-Vizcaíno, M J Román-Alpiste
We reconstruct the 3-D microstructure of centimetre-sized olivine crystals in rocks from the Almirez ultramafic massif (SE Spain) using combined X-ray micro computed tomography (μ-CT) and electron backscatter diffraction (EBSD). The semidestructive sample treatment involves geographically oriented drill pressing of rocks and preparation of oriented thin sections for EBSD from the μ-CT scanned cores. The μ-CT results show that the mean intercept length (MIL) analyses provide reliable information on the shape preferred orientation (SPO) of texturally different olivine groups...
July 7, 2017: Journal of Microscopy
https://www.readbyqxmd.com/read/28685238/functional-in-situ-assessment-of-human-articular-cartilage-using-mri-a-whole-knee-joint-loading-device
#15
Sven Nebelung, Manuel Post, Stefan Raith, Horst Fischer, Matthias Knobe, Benedikt Braun, Andreas Prescher, Markus Tingart, Johannes Thüring, Philipp Bruners, Holger Jahr, Christiane Kuhl, Daniel Truhn
The response to loading of human articular cartilage as assessed by magnetic resonance imaging (MRI) remains to be defined in relation to histology and biomechanics. Therefore, an MRI-compatible whole-knee joint loading device for the functional in situ assessment of cartilage was developed and validated in this study. A formalin-fixed human knee was scanned by computed tomography in its native configuration and digitally processed to create femoral and tibial bone models. The bone models were covered by artificial femoral and tibial articular cartilage layers in their native configuration using cartilage-mimicking polyvinyl siloxane...
July 6, 2017: Biomechanics and Modeling in Mechanobiology
https://www.readbyqxmd.com/read/28683215/monitoring-lung-cancer-screening-utilization-and-outcomes-in-four-cancer-research-network-sites
#16
Michael K Gould, Lori C Sakoda, Debra P Ritzwoller, Michael J Simoff, Christine M Neslund-Dudas, Lawrence H Kushi, Lisa Carter-Harris, Heather Spencer Feigelson, George Minowada, V Paul Doria-Rose
RATIONALE: Lung cancer screening registries can monitor screening outcomes and improve quality of care. OBJECTIVES: To describe nascent lung cancer screening programs and share efficient data collection approaches for mandatory registry reporting in four integrated health care systems of the NCI-funded Cancer Research Network. METHODS: We documented the distinctive characteristics of lung cancer screening programs, provided examples of strategies to facilitate data collection, and described early challenges and possible solutions...
July 6, 2017: Annals of the American Thoracic Society
https://www.readbyqxmd.com/read/28679248/ultrasound-field-characterization-using-synthetic-schlieren-tomography
#17
Aki Pulkkinen, Jarkko J Leskinen, Aimo Tiihonen
Synthetic schlieren imaging, also known as background oriented schlieren imaging, is used to determine the acoustical field of a focused ultrasound transducer operating at 1.01 MHz frequency with peak pressure amplitude of 0.97 MPa. The measurement setup is composed of a commercial off-the-shelf digital single-lens reflex (DSLR) camera with an ordinary objective, a high power light-emitting diode driven in pulsating mode, water tank, ultrasound transducer, rotation stage, and driving electronics. Measurements are performed in tomographic fashion by rotating the ultrasound transducer within the water tank and photographing an imaged target behind the ultrasound field...
June 2017: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/28675848/the-micro-damage-process-zone-during-transverse-cortical-bone-fracture-no-ears-at-crack-growth-initiation
#18
Thomas Willett, David Josey, Rick Xing Ze Lu, Gagan Minhas, John Montesano
OBJECTIVE: Apply high-resolution benchtop micro-computed tomography (micro-CT) to gain greater understanding and knowledge of the formation of the micro-damage process zone formed during traverse fracture of cortical bone. METHODS: Bovine cortical bone was cut into single edge notch (bending) fracture testing specimens with the crack on the transverse plane and oriented to grow in the circumferential direction. We used a multi-specimen technique and deformed the specimens to various individual secant modulus loss levels (P-values) up to and including maximum load (Pmax)...
June 24, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28675816/expanding-the-boundaries-of-cryo-em-with-phase-plates
#19
REVIEW
Radostin Danev, Wolfgang Baumeister
Phase plates have long been considered as a means for improving the performance of cryo-electron microscopy (cryo-EM). But practical limitations, such as a short lifespan or cumbersome usage have prevented their widespread adoption. The recently developed Volta phase plate overcomes most of the practical issues and it is now commercially available. Results from both, electron cryo-tomography (cryo-ET) and single particle analysis (SPA), have demonstrated the benefits of using a phase plate. In CET phase plates have helped to visualize cellular ultrastructure in unprecedented detail...
July 1, 2017: Current Opinion in Structural Biology
https://www.readbyqxmd.com/read/28674379/the-reliability-of-panoramic-radiography-versus-cone-beam-computed-tomography-when-evaluating-the-distance-to-the-alveolar-nerve-in-the-site-of-lateral-teeth
#20
Gabrielė Česaitienė, Kęstutis Česaitis, Jonas Junevičius, Tadas Venskutonis
BACKGROUND The aim of this study was to compare the reliability of panoramic radiography (PR) and cone beam computed tomography (CBCT) in the evaluation of the distance of the roots of lateral teeth to the inferior alveolar nerve canal (IANC). MATERIAL AND METHODS 100 PR and 100 CBCT images that met the selection criteria were selected from the database. In PR images, the distances were measured using an electronic caliper with 0.01 mm accuracy and white light x-ray film reviewer. Actual values of the measurements were calculated taking into consideration the magnification used in PR images (130%)...
July 4, 2017: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
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