Shack-Hartmann Electron Densitometer (SHED): An Optical System for Diagnosing Free Electron Density in Laser-Produced Plasmas

DTIC Science & Technology

2016-11-01

a few nanoseconds. The challenge remains to diagnose plasmas via the free electron density in this short window of time and often in a small volume ...Free Electron Density in Laser-Produced Plasmas by Anthony R Valenzuela Approved for public release; distribution is...US Army Research Laboratory Shack-Hartmann Electron Densitometer (SHED): An Optical System for Diagnosing Free Electron Density in Laser

Radiation safety analysis of the ISS bone densitometer

NASA Astrophysics Data System (ADS)

Todd, Paul; Vellinger, John C.; Barton, Kenneth; Faget, Paul

A Bone Densitometer (BD) has been developed for installation on the International Space Station (ISS) with delivery by the Space-X Dragon spacecraft planned for mid 2014. After initial tests on orbit the BD will be used in longitudinal measurements of bone mineral density in experimental mice as a means of evaluating countermeasures to bone loss. The BD determines bone mineral density (and other radiographic parameters) by dual energy x-ray absorptiometry (DEXA). In a single mouse DEXA “scan” its 80 kV x-ray tube is operated for 15 seconds at 35 kV and 3 seconds at 80 kV in four repetitions, giving the subject a total dose of 2.5 mSv. The BD is a modification of a commercial mouse DEXA product known as PIXImus(TM). Before qualifying the BD for utilization on ISS it was necessary to evaluate its radiation safety features and any level of risk to ISS crew members. The BD design reorients the PIXImus so that it fits in an EXPRESS locker on ISS with the x-ray beam directed into the crew aisle. ISS regulation SSP 51700 considers the production of ionizing radiation to be a catastrophic-level hazard. Accidental exposure is prevented by three independent levels of on-off control as required for a catastrophic hazard. The ALARA (As Low as Reasonably Achievable) principle was applied to the BD hazard just as would be done on the ground, so deliberate exposure is limited by lead shielding according to ALARA. Hot spots around the BD were identified by environmental dosimetry using a Ludlum 9DP pressurized ionization chamber survey meter. Various thicknesses of lead were applied to the BD housing in areas where highest dose-per-scan readings were made. It was concluded that 0.4 mm of lead shielding at strategic locations, adding only a few kg of mass to the payload, would accomplish ALARA. With shielding in place the BD now exposes a crew member floating 40 cm away to less than 0.08 microSv per mouse scan. There is an upper limit of 20 scans per day, or 1.6 microSv per day

Design, fabrication and calibration of alpha particle densitometers for measuring planetary atmospheric density

NASA Technical Reports Server (NTRS)

Sellers, B.; Hunerwadel, J. L.; Hanser, F. A.

1972-01-01

An alpha particle densitometer was developed for possible application to measurement of the atmospheric density-altitude profile on Martian entry. The device uses an Am-241 radioactive-foil source, which emits a distributed energy spectrum, located about 25 to 75 cm from a semiconductor detector. System response - defined as the number of alphas per second reaching the detector with energy above a fixed threshold - is given for Ar and CO2. The altitude profile of density measurement accuracy is given for a pure CO2 atmosphere with 5 mb surface pressure. The entire unit, including dc-dc converters, requires less than 350 milliwatts of power from +28 volts, weighs about 0.85 lb and occupies less than 15 cubic inches volume.

Small animal bone density and morphometry analysis with a dual energy x-ray absorptiometry bone densitometer using a 2D digital radiographic detector

NASA Astrophysics Data System (ADS)

Boudousq, V.; Bordy, T.; Gonon, G.; Dinten, J. M.

2005-04-01

The LEXXOS (DMS, Montpellier, France) is the first axial and total body cone beam bone densitometer using a 2D digital radiographic detector. Technical principles and performances for BMD measurements have been presented in previous papers. Bone densitometers are also used on small animals for drug development. In this paper, we show how the LEXXOS system can be adapted to small animals examinations, and its performances are evaluated. At first, in order to take advantage of the whole area of the digital flat panel X-ray detector, the geometrical configuration has been adapted. Secondly, as small animals present low BMD, a specific dual energy calibration has been defined. This adapted system has then been evaluated on two sets of mice: six reference mice and six ovariectomized mice. Each month, these two populations have been examined and the total body BMD has been measured. This evaluation has shown that the right order of BMD magnitude has been obtained and, as expected, BMD increases on the two sets until age of puberty and after this period, decreases significantly for the ovariectomized set. Moreover, the bone image obtained by dual energy processing on LEXXOS presents a radiographic image quality providing with useful complementary information on bone morphometry and architecture.

Definition of osteoporosis by bone density criteria in men: effect of using female instead of male young reference data depends on skeletal site and densitometer manufacturer.

PubMed

Schousboe, John T; Tanner, S Bobo; Leslie, William D

2014-01-01

Whether to use young male or young female reference data to calculate bone mineral density (BMD) T-scores in men remains controversial. The third National Health and Nutrition Examination and Survey (NHANES III) data show that the mean and standard deviation of femoral neck and total hip BMD is greater in young men than young women, and therefore differences in T-scores at these sites using NHANES III female vs male norms becomes less as BMD decreases. In contrast, manufacturer-specific reference databases generally assume similar standard deviations of BMD in men and women. Using NHANES III reference data for the femoral neck and total hip, respectively we found that men with T-scores of -2.5 when young male norms are used have T-scores of -2.4 and -2.3 when young female norms are used. Using manufacturer-specific reference data, we found that men with T-scores of -2.5 when young male norms are used at the femoral neck, total hip, lumbar spine, or one-third of the forearm would have T-scores ranging from -2.4 to -0.4 when young female norms are used, depending on skeletal site and densitometer manufacturer. The change of proportions of men diagnosed with osteoporosis when young female norms are used instead of young male reference data differs substantially according to skeletal site and densitometer manufacturer. Copyright © 2014 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Outdoor solar UVA dose assessment with EBT2 radiochromic film using spectrophotometer and densitometer measurements.

PubMed

Abukassem, I; Bero, M A

2015-04-01

Direct measurements of solar ultraviolet radiations (UVRs) have an important role in the protection of humans against UVR hazard. This work presents simple technique based on the application of EBT2 GAFCHROMIC(®) film for direct solar UVA dose assessment. It demonstrates the effects of different parts of the solar spectrum (UVB, visible and infrared) on performed UVA field measurements and presents the measurement uncertainty budget. The gradient of sunlight exposure level permitted the authors to establish the mathematical relationships between the measured solar UVA dose and two measured quantities: the first was the changes in spectral absorbance at the wavelength 633 nm (A633) and the second was the optical density (OD). The established standard relations were also applied to calculate the solar UVA dose variations during the whole day; 15 min of exposure each hour between 8:00 and 17:00 was recorded. Results show that both applied experimental methods, spectrophotometer absorbance and densitometer OD, deliver comparable figures for EBT2 solar UVA dose assessment with relative uncertainty of 11% for spectral absorbance measurements and 15% for OD measurements. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparison of electrical capacitance tomography & gamma densitometer measurement in viscous oil-gas flows

NASA Astrophysics Data System (ADS)

Archibong Eso, A.; Zhao, Yabin; Yeung, Hoi

2014-04-01

Multiphase flow is a common occurrence in industries such as nuclear, process, oil & gas, food and chemical. A prior knowledge of its features and characteristics is essential in the design, control and management of such processes due to its complex nature. Electrical Capacitance Tomography (ECT) and Gamma Densitometer (Gamma) are two promising approaches for multiphase visualization and characterization in process industries. In two phase oil & gas flow, ECT and Gamma are used in multiphase flow monitoring techniques due to their inherent simplicity, robustness, and an ability to withstand wide range of operational temperatures and pressures. High viscous oil (viscosity > 100 cP) is of interest because of its huge reserves, technological advances in its production and unlike conventional oil (oil viscosity < 100 cP) and gas flows where ECT and Gamma have been previously used, high viscous oil and gas flows comes with certain associated concerns which include; increased entrainment of gas bubbles dispersed in oil, shorter and more frequent slugs as well as oil film coatings on the walls of flowing conduits. This study aims to determine the suitability of both devices in the visualization and characterization of high-viscous oil and gas flow. Static tests are performed with both devices and liquid holdup measurements are obtained. Dynamic experiments were also conducted in a 1 & 3 inch facility at Cranfield University with a range of nominal viscosities (1000, 3000 & 7500 cP). Plug, slug and wavy annular flow patterns were identified by means of Probability Mass Function and time series analysis of the data acquired from Gamma and ECT devices with high speed camera used to validate the results. Measured Liquid holdups for both devices were also compared.

Gender disparity in BMD conversion: a comparison between Lunar and Hologic densitometers.

PubMed

Ganda, Kirtan; Nguyen, Tuan V; Pocock, Nicholas

2014-01-01

Female-derived inter-conversion and standardised BMD equations at the lumbar spine and hip have not been validated in men. This study of 110 male subjects scanned on Hologic and Lunar densitometers demonstrates that published equations may not applicable to men at the lumbar spine. Male inter-conversion equations have also been derived. Currently, available equations for inter-manufacturer conversion of bone mineral density (BMD) and calculation of standardised BMD (sBMD) are used in both males and females, despite being derived and validated only in women. Our aim was to test the validity of the published equations in men. One hundred ten men underwent lumbar spine (L2-4), femoral neck (FN) and total hip (TH) dual X-ray absorptiometry (DXA) using Hologic and Lunar scanners. Hologic BMD was converted to Lunar using published equations derived from women for L2-4 and FN. Actual Lunar BMD (A-Lunar) was compared to converted (Lunar equivalent) Hologic BMD values (H-Lunar). sBMD was calculated separately using Hologic (sBMD-H) and Lunar BMD (sBMD-L) at L2-4, FN and TH. Conversion equations in men for Hologic to Lunar BMD were derived using Deming regression analysis. There was a strong linear correlation between Lunar and Hologic BMD at all skeletal sites. A-Lunar BMD was however significantly higher than derived H-Lunar BMD (p < 0.001) at L2-L4 (mean difference, 0.07 g/cm(2)). There was no significant difference at the FN (mean difference, 0.01 g/cm(2)). sBMD-L at the spine was significantly higher than sBMD-H (mean difference, 0.06 g/cm(2), p < 0.001), whilst there was little difference at the FN and TH (mean difference, 0.01 g/cm(2)). Published conversion equations for Lunar BMD to Hologic BMD, and formulae for lumbar spine sBMD, derived in women may not be applicable to men.

Comparison of electrical capacitance tomography and gamma densitometer measurement in viscous oil-gas flows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Archibong Eso, A.; Zhao, Yabin; Yeung, Hoi

2014-04-11

Multiphase flow is a common occurrence in industries such as nuclear, process, oil and gas, food and chemical. A prior knowledge of its features and characteristics is essential in the design, control and management of such processes due to its complex nature. Electrical Capacitance Tomography (ECT) and Gamma Densitometer (Gamma) are two promising approaches for multiphase visualization and characterization in process industries. In two phase oil and gas flow, ECT and Gamma are used in multiphase flow monitoring techniques due to their inherent simplicity, robustness, and an ability to withstand wide range of operational temperatures and pressures. High viscous oilmore » (viscosity > 100 cP) is of interest because of its huge reserves, technological advances in its production and unlike conventional oil (oil viscosity < 100 cP) and gas flows where ECT and Gamma have been previously used, high viscous oil and gas flows comes with certain associated concerns which include; increased entrainment of gas bubbles dispersed in oil, shorter and more frequent slugs as well as oil film coatings on the walls of flowing conduits. This study aims to determine the suitability of both devices in the visualization and characterization of high-viscous oil and gas flow. Static tests are performed with both devices and liquid holdup measurements are obtained. Dynamic experiments were also conducted in a 1 and 3 inch facility at Cranfield University with a range of nominal viscosities (1000, 3000 and 7500 cP). Plug, slug and wavy annular flow patterns were identified by means of Probability Mass Function and time series analysis of the data acquired from Gamma and ECT devices with high speed camera used to validate the results. Measured Liquid holdups for both devices were also compared.« less

Microdensitometer errors: Their effect on photometric data reduction

NASA Technical Reports Server (NTRS)

Bozyan, E. P.; Opal, C. B.

1984-01-01

The performance of densitometers used for photometric data reduction of high dynamic range electrographic plate material is analyzed. Densitometer repeatability is tested by comparing two scans of one plate. Internal densitometer errors are examined by constructing histograms of digitized densities and finding inoperative bits and differential nonlinearity in the analog to digital converter. Such problems appear common to the four densitometers used in this investigation and introduce systematic algorithm dependent errors in the results. Strategies to improve densitometer performance are suggested.

Rodent bone densitometer on the International Space Station: Instrument design and performance

NASA Astrophysics Data System (ADS)

Vellinger, John C.; Barton, Kenneth; Faget, Paul; Todd, Paul; Boland, Eugene

2016-07-01

The study of bone loss dynamics, mechanisms and countermeasures has been a publicly stated purpose of biomedical research aboard the International Space Station. Rodent research has always played a major role in terrestrial laboratories studying bone loss. The "gold standard" for assessing bone loss in human patients has been dual-energy x-ray absorptiometry (DEXA). DEXA is also widely applied to the study of bone loss in laboratory animals, so this technology has been added to the ISS inventory of analytical tools in the form of the ISS Bone Densitometer (BD) designed, constructed, tested and integrated by Techshot, Inc. (Greenville, Indiana, USA). The BD is a re-packaged COTS device known as PIXImus (GE-Lunar, USA), which was installed on ISS in November 2014 after launching on SpaceX-4. To facilitate operations in microgravity and to meet spaceflight facility and safety requirements the commercial x-ray source, control electronics and imaging system were modified and packaged by Techshot into a drawer that fits into a single EXPRESS Locker replacement. A space-rated "Exam Box" is also supplied for containment of the anesthetized subject during transfer into the BD and during exposure. The commercial software package controls four paired-energy exposures, 80 and 35 kV, and applies DEXA algorithms to the fluorescence images and displays bone mineral density (BMD), bone mineral content, lean mass, fat mass, total mass and per cent fat. The BD is therefore also a means for measuring mass and body composition making it a versatile tool for many types of rodent studies on orbit. The BD has been operated multiple times on orbit, and its performance has not differed significantly from its performance on the ground. It has been shown to measure body mass with a precision of +/- 0.1 g and on-orbit accuracy of -0.3 g. It is expected to detect BMD losses of approximately 2%. The image data are stored in a manner that allows post-test data analysis especially including the

Concordance of macular pigment measurements obtained using customized heterochromatic flicker photometry, dual-wavelength autofluorescence, and single-wavelength reflectance.

PubMed

Dennison, Jessica L; Stack, Jim; Beatty, Stephen; Nolan, John M

2013-11-01

This study compares in vivo measurements of macular pigment (MP) obtained using customized heterochromatic flicker photometry (cHFP; Macular Metrics Densitometer(™)), dual-wavelength fundus autofluorescence (Heidelberg Spectralis(®) HRA + OCT MultiColor) and single-wavelength fundus reflectance (Zeiss Visucam(®) 200). MP was measured in one eye of 62 subjects on each device. Data from 49 subjects (79%) was suitable for analysis. Agreement between the Densitometer and Spectralis was investigated at various eccentricities using a variety of quantitative and graphical methods, including: Pearson correlation coefficient to measure degree of scatter (precision), accuracy coefficient, concordance correlation coefficient (ccc), paired t-test, scatter and Bland-Altman plots. The relationship between max MP from the Visucam and central MP from the Spectralis and Densitometer was investigated using regression methods. Agreement was strong between the Densitometer and Spectralis at all central eccentricities (e.g. at 0.25° eccentricity: accuracy = 0.97, precision = 0.90, ccc = 0.87). Regression analysis showed a very weak relationship between the Visucam and Densitometer (e.g. Visucam max on Densitometer central MP: R(2) = 0.008, p = 0.843). Regression analysis also demonstrated a weak relationship between MP measured by the Spectralis and Visucam (e.g. Visucam max on Spectralis central MP: R(2) = 0.047, p = 0.348). MP values obtained using the Heidelberg Spectralis are comparable to MP values obtained using the Densitometer. In contrast, MP values obtained using the Zeiss Visucam are not comparable with either the Densitometer or the Spectralis MP measuring devices. Taking cHFP as the current standard to which other MP measuring devices should be compared, the Spectralis is suitable for use in a clinical and research setting, whereas the Visucam is not. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparison of Hybrid K-Edge Densitometer (HKED) Performance Operating with the Canberra Lynx MCA and the Canberra ICB-NIM Electronics

DOE Office of Scientific and Technical Information (OSTI.GOV)

McElroy, Robert Dennis

From the 1991 until 2008 the Canberra Hybrid K-Edge Densitometer systems were provided with ICB-NIM (Integrated Control Bus – Nuclear Instrument Module) acquisition electronics. Newer electronics modules, such as the Lynx, were not supported under the VMS based operating system. The LYNX module was provided as the standard acquisition electronics following the release of the Windows based CHKED software. This report compares the electronics dead-time, gain shifts, detector resolution and measurement performance of the HKED system operated with the two types of acquisition modules. The comparison was performed using measurements obtained with the ORNL HKED system. The original intent ofmore » this study was to take advantage of both the timing and energy outputs from the HPGE detector to acquire data with both sets of electronics in parallel. Although this approach has been applied successfully with other systems, in this case we found the timing output produced a significant amount of noise such that a comparison between the electronics would be invalid. So the comparative measurements were performed sequentially. The ICB-NIM data was acquired over the course of 12 months with 255 measurements while the LYNX data was acquired over a period of 10 months with 75 measurements. To simplify the comparison, all data used in this study was acquired using the Canberra CHKED (V1.0) software package. The performance analysis was based primarily on the peak locations, peak widths and concentration values reported by the CHKED software. The raw spectra from the XRF measurements were also examined to extract additional 109Cd peak location and width data for the hybrid measurements (the standard hybrid report template does not report these values).« less

75 FR 60614 - Airworthiness Directives; The Boeing Company Model 747-400, 747-400D, and 747-400F Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-01

... source outside the FQIS to the densitometer wiring from causing failure of the FQIS densitometer... wiring of the other systems as a result of implementing the actions required by this AD. Boeing requests... are implemented, then no further actions are required to separate the FQIS wire from the wiring of...

Online capacitive densitometer

DOEpatents

Porges, K.G.

1988-01-21

This invention is an apparatus for measuring fluid density of mixed phase fluid flow. The apparatus employs capacitive sensing of the mixed phased flow combined with means for uniformizing the electric field between the capacitor plates to account for flow line geometry. From measurement of fluid density, the solids feedrate can be ascertained. 7 figs.

Online capacitive densitometer

DOEpatents

Porges, Karl G.

1990-01-01

This invention is an apparatus for measuring fluid density of mixed phase fluid flow. The apparatus employs capacitive sensing of the mixed phased flow combined with means for uniformizing the electric field between the capacitor plates to account for flow line geometry. From measurement of fluid density, the solids feedrate can be ascertained.

DOE Office of Scientific and Technical Information (OSTI.GOV)

HUBER, J.H.

An Enraf Densitometer is installed on tank 241-AY-102. The Densitometer will frequently be tasked to obtain and log density profiles. The activity can be effected a number of ways. Enraf Incorporated provides a software package called ''Logger18'' to its customers for the purpose of in-shop testing of their gauges. Logger18 is capable of accepting an input file which can direct the gauge to obtain a density profile for a given tank level and bottom limit. Logger18 is a complex, DOS based program which will require trained technicians and/or tank farm entries to obtain the data. ALARA considerations have prompted themore » development of a more user-friendly, computer-based interface to the Enraf densitometers. This document records the plan by which this new Enraf data acquisition software will be developed, reviewed, verified, and released. This plan applies to the development and implementation of a one-time-use software program, which will be called ''Enraf Control Panel.'' The software will be primarily used for remote operation of Enraf Densitometers for the purpose of obtaining and logging tank product density profiles.« less

Flowmeter for gas-entrained solids flow

DOEpatents

Porges, Karl G.

1990-01-01

An apparatus and method for the measurement of solids feedrate in a gas-entrained solids flow conveyance system. The apparatus and method of the present invention include a vertical duct connecting a source of solids to the gas-entrained flow conveyance system, a control valve positioned in the vertical duct, and a capacitive densitometer positioned along the duct at a location a known distance below the control valved so that the solid feedrate, Q, of the gas entrained flow can be determined by Q=S.rho..phi.V.sub.S where S is the cross sectional area of the duct, .rho. is the density of the solid, .phi. is the solid volume fraction determined by the capacitive densitometer, and v.sub.S is the local solid velocity which can be inferred from the konown distance of the capacitive densitometer below the control valve.

An Investigation Into the Differences in Bone Density and Body Composition Measurements Between 2 GE Lunar Densitometers and Their Comparison to a 4-Component Model.

PubMed

Watson, Laura P E; Venables, Michelle C; Murgatroyd, Peter R

We describe a study to assess the precision of the GE Lunar iDXA and the agreement between the iDXA and GE Lunar Prodigy densitometers for the measurement of regional- and total-body bone and body composition in normal to obese healthy adults. We compare the whole-body fat mass by dual-energy X-ray absorptiometry (DXA) to measurements by a 4-component (4-C) model. Sixty-nine participants, aged 37 ± 12 yr, with a body mass index of 26.2 ± 5.1 kg/cm 2 , were measured once on the Prodigy and twice on the iDXA. The 4-C model estimated fat mass from body mass, total body water by deuterium dilution, body volume by air displacement plethysmography, and bone mass by DXA. Agreements between measurements made on the 2 instruments and by the 4-C model were analyzed by Bland-Altman and linear regression analyses. Where appropriate, translational cross-calibration equations were derived. Differences between DXA software versions were investigated. iDXA precision was less than 2% of the measured value for all regional- and whole-body bone and body composition measurements with the exception of arm fat mass (2.28%). We found significant differences between iDXA and Prodigy (p < 0.05) whole-body and regional bone, fat mass (FM), and lean mass, with the exception of hip bone mass, area and density, and spine area. Compared to iDXA, Prodigy overestimated FM and underestimated lean mass. However, compared to 4-C, iDXA showed a smaller bias and narrower limits of agreement than Prodigy. No significant differences between software versions in FM estimations existed. Our results demonstrate excellent iDXA precision. However, significant differences exist between the 2 GE Lunar instruments, Prodigy and iDXA measurement values. A divergence from the reference 4-C observations remains in FM estimations made by DXA even following the recent advances in technology. Further studies are particularly warranted in individuals with large FM contents. Copyright © 2017. Published

An index of refraction algorithm for seawater over temperature, pressure, salinity, density, and wavelength

NASA Astrophysics Data System (ADS)

Millard, R. C.; Seaver, G.

1990-12-01

A 27-term index of refraction algorithm for pure and sea waters has been developed using four experimental data sets of differing accuracies. They cover the range 500-700 nm in wavelength, 0-30°C in temperature, 0-40 psu in salinity, and 0-11,000 db in pressure. The index of refraction algorithm has an accuracy that varies from 0.4 ppm for pure water at atmospheric pressure to 80 ppm at high pressures, but preserves the accuracy of each original data set. This algorithm is a significant improvement over existing descriptions as it is in analytical form with a better and more carefully defined accuracy. A salinometer algorithm with the same uncertainty has been created by numerically inverting the index algorithm using the Newton-Raphson method. The 27-term index algorithm was used to generate a pseudo-data set at the sodium D wavelength (589.26 nm) from which a 6-term densitometer algorithm was constructed. The densitometer algorithm also produces salinity as an intermediate step in the salinity inversion. The densitometer residuals have a standard deviation of 0.049 kg m -3 which is not accurate enough for most oceanographic applications. However, the densitometer algorithm was used to explore the sensitivity of density from this technique to temperature and pressure uncertainties. To achieve a deep ocean densitometer of 0.001 kg m -3 accuracy would require the index of refraction to have an accuracy of 0.3 ppm, the temperature an accuracy of 0.01°C and the pressure 1 db. Our assessment of the currently available index of refraction measurements finds that only the data for fresh water at atmospheric pressure produce an algorithm satisfactory for oceanographic use (density to 0.4 ppm). The data base for the algorithm at higher pressures and various salinities requires an order of magnitude or better improvement in index measurement accuracy before the resultant density accuracy will be comparable to the currently available oceanographic algorithm.

Direct Comparison of the Precision of the New Hologic Horizon Model With the Old Discovery Model.

PubMed

Whittaker, LaTarsha G; McNamara, Elizabeth A; Vath, Savoun; Shaw, Emily; Malabanan, Alan O; Parker, Robert A; Rosen, Harold N

2017-11-22

Previous publications suggested that the precision of the new Hologic Horizon densitometer might be better than that of the previous Discovery model, but these observations were confounded by not using the same participants and technologists on both densitometers. We sought to study this issue methodically by measuring in vivo precision in both densitometers using the same patients and technologists. Precision studies for the Horizon and Discovery models were done by acquiring spine, hip, and forearm bone mineral density twice on 30 participants. The set of 4 scans on each participant (2 on the Discovery, 2 on the Horizon) was acquired by the same technologist using the same scanning mode. The pairs of data were used to calculate the least significant change according to the International Society for Clinical Densitometry guidelines. The significance of the difference between least significant changes was assessed using a Wilcoxon signed-rank test of the difference between the mean square error of the absolute value of the differences between paired measurements on the Discovery (Δ-Discovery) and the mean square error of the absolute value of the differences between paired measurements on the Horizon (Δ-Horizon). At virtually all anatomic sites, there was a nonsignificant trend for the precision to be better for the Horizon than for the Discovery. As more vertebrae were excluded from analysis, the precision deteriorated on both densitometers. The precision between densitometers was almost identical when reporting only 1 vertebral body. (1) There was a nonsignificant trend for greater precision on the new Hologic Horizon compared with the older Discovery model. (2) The difference in precision of the spine bone mineral density between the Horizon and the Discovery models decreases as fewer vertebrae are included. (3) These findings are substantially similar to previously published results which had not controlled as well for confounding from using different

Concordance of Macular Pigment Measurement Using Customized Heterochromatic Flicker Photometry and Fundus Autofluorescence in Age-Related Macular Degeneration.

PubMed

Akuffo, Kwadwo Owusu; Beatty, Stephen; Stack, Jim; Peto, Tunde; Leung, Irene; Corcoran, Laura; Power, Rebecca; Nolan, John M

2015-12-01

We compared macular pigment (MP) measurements using customized heterochromatic flicker photometry (Macular Metrics Densitometer) and dual-wavelength fundus autofluorescence (Heidelberg Spectralis HRA + OCT MultiColor) in subjects with early age-related macular degeneration (AMD). Macular pigment was measured in 117 subjects with early AMD (age, 44-88 years) using the Densitometer and Spectralis, as part of the Central Retinal Enrichment Supplementation Trial (CREST; ISRCTN13894787). Baseline and 6-month study visits data were used for the analyses. Agreement was investigated at four different retinal eccentricities, graphically and using indices of agreement, including Pearson correlation coefficient (precision), accuracy coefficient, and concordance correlation coefficient (ccc). Agreement was poor between the Densitometer and Spectralis at all eccentricities, at baseline (e.g., at 0.25° eccentricity, accuracy = 0.63, precision = 0.35, ccc = 0.22) and at 6 months (e.g., at 0.25° eccentricity, accuracy = 0.52, precision = 0.43, ccc = 0.22). Agreement between the two devices was significantly greater for males at 0.5° and 1.0° of eccentricity. At all eccentricities, agreement was unaffected by cataract grade. In subjects with early AMD, MP measurements obtained using the Densitometer and Spectralis are not statistically comparable and should not be used interchangeably in either the clinical or research setting. Despite this lack of agreement, statistically significant increases in MP, following 6 months of supplementation with macular carotenoids, were detected with each device, confirming that these devices are capable of measuring change in MP within subjects over time. (http://www.controlled-trials.com number, ISRCTN13894787.).

Miniature X-Ray Bone Densitometer

NASA Technical Reports Server (NTRS)

Charles, Harry K., Jr.

1999-01-01

The purpose of the Dual Energy X-ray Absorptiometry (DEXA) project is to design, build, and test an advanced X-ray absorptiometry scanner capable of being used to monitor the deleterious effects of weightlessness on the human musculoskeletal system during prolonged spaceflight. The instrument is based on the principles of dual energy x-ray absorptiometry and is designed not only to measure bone, muscle, and fat masses but also to generate structural information about these tissues so that the effects on mechanical integrity may be assessed using biomechanical principles. A skeletal strength assessment could be particularly important for an astronaut embarking on a remote planet where the consequences of a fragility fracture may be catastrophic. The scanner will employ multiple projection images about the long axis of the scanned subject to provide geometric properties in three dimensions, suitable for a three-dimensional structural analysis of the scanned region. The instrument will employ advanced fabrication techniques to minimize volume and mass (100 kg current target with a long-term goal of 60 kg) of the scanner as appropriate for the space environment, while maintaining the required mechanical stability for high precision measurement. The unit will have the precision required to detect changes in bone mass and geometry as small as 1% and changes in muscle mass as small as 5%. As the system evolves, advanced electronic fabrication technologies such as chip-on-board and multichip modules will be combined with commercial (off-the-shelf) parts to produce a reliable, integrated system which not only minimizes size and weight, but, because of its simplicity, is also cost effective to build and maintain. Additionally, the system is being designed to minimize power consumption. Methods of heat dissipation and mechanical stowage (for the unit when not in use) are being optimized for the space environment.

Enhanced Precision of the New Hologic Horizon Model Compared With the Old Discovery Model Is Less Evident When Fewer Vertebrae Are Included in the Analysis.

PubMed

McNamara, Elizabeth A; Kilim, Holly P; Malabanan, Alan O; Whittaker, LaTarsha G; Rosen, Harold N

The International Society for Clinical Densitometry guidelines recommend using locally derived precision data for spine bone mineral densities (BMDs), but do not specify whether data derived from L1-L4 spines correctly reflect the precision for spines reporting fewer than 4 vertebrae. Our experience suggested that the decrease in precision with successively fewer vertebrae is progressive as more vertebrae are excluded and that the precision for the newer Horizon Hologic model might be better than that for the previous model, and we sought to quantify. Precision studies were performed on Hologic densitometers by acquiring spine BMD in fast array mode twice on 30 patients, according to International Society for Clinical Densitometry guidelines. This was done 10 different times on various Discovery densitometers, and once on a Horizon densitometer. When 1 vertebral body was excluded from analysis, there was no significant deterioration in precision. When 2 vertebrae were excluded, there was a nonsignificant trend to poorer precision, and when 3 vertebrae were excluded, there was significantly worse precision. When 3 or 4 vertebrae were reported, the precision of the spine BMD measurement was significantly better on the Hologic Horizon than on the Discovery, but the difference in precision between densitometers narrowed and was no longer significant when 1 or 2 vertebrae were reported. The results suggest that (1) the measurement of in vivo spine BMD on the new Hologic Horizon densitometer is significantly more precise than on the older Discovery model; (2) the difference in precision between the Horizon and Discovery models decreases as fewer vertebrae are included; (3) the measurement of spine BMD is less precise as more vertebrae are excluded, but still quite reasonable even when only 1 vertebral body is included; and (4) when 3 vertebrae are reported, L1-L4 precision data can reasonably be used to report significance of changes in BMD. When 1 or 2 vertebrae are

Accommodating brightness and exposure levels in densitometry of stained polyacrylamide electrophoresis gels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tan, Han Yen; Ng, Tuck Wah; Liew, Oi Wah

2010-03-20

Flatbed scanner densitometers can be operated under various illumination and recording exposure levels. In this work, we show that optical density measurement accuracy, sensitivity, and stability of stained polyacrylamide electrophoresis gel densitometry are crucially dependent on these two factors (brightness and exposure level), notwithstanding that the source is monochromatic, spatially uniform, and the measurements are made using an accurately calibrated step wedge in tandem. We further outline a method to accommodate the intensity deviations over a range of illumination and exposure levels in order to maintain sensitivity and repeatability in the computed optical densities. Comparisons were also made with resultsmore » from a commercial densitometer.« less

RESTORATION OF ATMOSPHERICALLY DEGRADED IMAGES. VOLUME 3.

DTIC Science & Technology

AERIAL CAMERAS, LASERS, ILLUMINATION, TRACKING CAMERAS, DIFFRACTION, PHOTOGRAPHIC GRAIN, DENSITY, DENSITOMETERS, MATHEMATICAL ANALYSIS, OPTICAL SCANNING, SYSTEMS ENGINEERING, TURBULENCE, OPTICAL PROPERTIES, SATELLITE TRACKING SYSTEMS.

Simulation of Hanford Tank 241-C-106 Waste Release into Tank 241-Y-102

DOE Office of Scientific and Technical Information (OSTI.GOV)

KP Recknagle; Y Onishi

Waste stored in Hdord single-shell Tank 241-C-106 will be sluiced with a supernatant liquid from doubIe-shell Tank 241 -AY- 102 (AY-1 02) at the U.S. Department of Energy's Har@ord Site in Eastern Washington. The resulting slurry, containing up to 30 wtYo solids, will then be transferred to Tank AY-102. During the sluicing process, it is important to know the mass of the solids being transferred into AY- 102. One of the primary instruments used to measure solids transfer is an E+ densitometer located near the periphery of the tank at riser 15S. This study was undert.dcen to assess how wellmore » a densitometer measurement could represent the total mass of soiids transferred if a uniform lateral distribution was assumed. The study evaluated the C-1 06 slurry mixing and accumulation in Tank AY- 102 for the following five cases: Case 1: 3 wt'%0 slurry in 6.4-m AY-102 waste Case 2: 3 w-t% slurry in 4.3-m AY-102 waste Case 3: 30 wtYo slurry in 6.4-m AY-102 waste Case 4: 30 wt% slurry in 4.3-m AY-102 waste Case 5: 30 wt% slurry in 5. O-m AY-102 waste. The tirne-dependent, three-dimensional, TEMPEST computer code was used to simulate solid deposition and accumulation during the injection of the C-106 slurry into AY-102 through four injection nozzles. The TEMPEST computer code was applied previously to other Hanford tanks, AP-102, SY-102, AZ-101, SY-101, AY-102, and C-106, to model tank waste mixing with rotating pump jets, gas rollover events, waste transfer from one tank to another, and pump-out retrieval of the sluiced waste. The model results indicate that the solid depth accumulated at the densitometer is within 5% of the average depth accumulation. Thus the reading of the densitometer is expected to represent the total mass of the transferred solids reasonably well.« less

BD Maintenance

NASA Image and Video Library

2017-06-19

iss052e004198 (June 19, 2017) ---- Astronaut Peggy Whitson changes out the Imaging Unit on the Bone Densitometer inside the Harmony module. The SpaceX Dragon is attached to the Earth-facing port of Harmony.

AN EVALUATION OF TWO GROUND-BASED CROWN CLOSURE ESTIMATION TECHNIQUES COMPARED TO CROWN CLOSURE ESTIMATES DERIVED FROM HIGH RESOLUTION IMAGERY

EPA Science Inventory

Two ground-based canopy closure estimation techniques, the Spherical Densitometer (SD) and the Vertical Tube (VT), were compared for the effect of deciduous understory on dominant/co-dominant crown closure estimates in even-aged loblolly (Pinus taeda) pine stands located in the N...

AN EVALUATION OF TWO GROUND-BASED CROWN CLOSURE ESTIMATION TECHNIQUES COMPARED TO CROWN CLOSURE ESTIMATES DERIVED FROM HIGH RESOLUTION IMAGERY

EPA Science Inventory

Two ground-based canopy closure estimation techniques, the Spherical Densitometer (SD) and the Vertical Tube (VT), were compared for the effect of deciduous understory on dominantlco-dominant crown closure estimates in even-aged loblolly (Pinus taeda) pine stands located in the N...

Sounding rocket flight report, MUMP 9 and MUMP 10

NASA Technical Reports Server (NTRS)

Grassl, H. J.

1971-01-01

The results of the launching of two-Marshall-University of Michigan Probes (MUMP 9 and MUMP 10), Nike-Tomahawk sounding rocket payloads, are summarized. The MUMP is similar to the thermosphere probe, an ejectable instrument package for studying the variability of the earth's atmospheric parameters. The MUMP 9 payload included an omegatron mass analyzer, a molecular fluorescence densitometer, a mini-tilty filter, and a lunar position sensor. This complement of instruments permitted the determination of the molecular nitrogen density and temperature in the altitude range from approximately 143 to 297 km over Wallops Island, Virginia, during January 1971. The MUMP 10 payload included an omegatron mass analyzer, an electron temperature probe, a cryogenic densitometer, and a solar position sensor. These instruments permitted the determination of the molecular nitrogen density and temperature and the charged particle density and temperature in the altitude range from approximately 145 to 290 km over Wallops Island during the afternoon preceding the MUMP 9 launch.

40 CFR 63.11646 - What are my compliance requirements?

Code of Federal Regulations, 2012 CFR

2012-07-01

... with Method 29 must collect a minimum sample volume of 0.85 dry standard cubic meters (30 dry standard... weight measurement device, mass flow meter, or densitometer and volumetric flow meter to measure ore...) Measure the weight of concentrate (produced by electrowinning, Merrill Crowe process, gravity feed, or...

40 CFR 63.11646 - What are my compliance requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

... with Method 29 must collect a minimum sample volume of 0.85 dry standard cubic meters (30 dry standard... weight measurement device, mass flow meter, or densitometer and volumetric flow meter to measure ore...) Measure the weight of concentrate (produced by electrowinning, Merrill Crowe process, gravity feed, or...

40 CFR 63.11646 - What are my compliance requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

... with Method 29 must collect a minimum sample volume of 0.85 dry standard cubic meters (30 dry standard... weight measurement device, mass flow meter, or densitometer and volumetric flow meter to measure ore...) Measure the weight of concentrate (produced by electrowinning, Merrill Crowe process, gravity feed, or...

40 CFR 63.11646 - What are my compliance requirements?

Code of Federal Regulations, 2013 CFR

2013-07-01

... with Method 29 must collect a minimum sample volume of 0.85 dry standard cubic meters (30 dry standard... weight measurement device, mass flow meter, or densitometer and volumetric flow meter to measure ore...) Measure the weight of concentrate (produced by electrowinning, Merrill Crowe process, gravity feed, or...

Thin spray film thickness measuring technique

NASA Technical Reports Server (NTRS)

Jones, G.; Kurtz, G. W.

1971-01-01

Thin spray film application depths, in the 0.0002 cm to 0.002 cm range, are measured by portable, commercially available, light density measuring device used in conjunction with glass plate or photographic film. Method is automated by using mechanical/electrical control for shutting off film applicator at desired densitometer reading.

Liquid hydrogen densitometer utilizes open-ended microwave cavity

NASA Technical Reports Server (NTRS)

Smetana, J.; Wenger, N. C.

1967-01-01

Open-ended microwave cavity directly measures the density of flowing liquid, gaseous, or two-phase hydrogen. Its operation is based on derived relations between the cavity resonant frequency and the dielectric constant and density of hydrogen.

Use of a variable exposure photographic pyrometer to measure surface temperatures on a hemispherical-face model

NASA Technical Reports Server (NTRS)

Kantsios, A. G.; Henley, W. C., Jr.; Snow, W. L.

1982-01-01

The use of a photographic pyrometer for nonintrusive measurement of high temperature surfaces in a wind tunnel test is described. The advantages of the pyrometer for measuring surfaces whose unique shape makes use of thermocouples difficult are pointed out. The use of computer operated densitometers or optical processors for the data reduction is recommended.

Effect of poor control of film processors on mammographic image quality.

PubMed

Kimme-Smith, C; Sun, H; Bassett, L W; Gold, R H

1992-11-01

With the increasingly stringent standards of image quality in mammography, film processor quality control is especially important. Current methods are not sufficient for ensuring good processing. The authors used a sensitometer and densitometer system to evaluate the performance of 22 processors at 16 mammographic facilities. Standard sensitometric values of two films were established, and processor performance was assessed for variations from these standards. Developer chemistry of each processor was analyzed and correlated with its sensitometric values. Ten processors were retested, and nine were found to be out of calibration. The developer components of hydroquinone, sulfites, bromide, and alkalinity varied the most, and low concentrations of hydroquinone were associated with lower average gradients at two facilities. Use of the sensitometer and densitometer system helps identify out-of-calibration processors, but further study is needed to correlate sensitometric values with developer component values. The authors believe that present quality control would be improved if sensitometric or other tests could be used to identify developer components that are out of calibration.

Sounding rocket flight report: MUMP 9 and MUMP 10

NASA Technical Reports Server (NTRS)

Grassl, H. J.

1971-01-01

The results of the launching of two Marshall-University of Michigan Probes (MUMP 9 and MUMP 10), Nike-Tomahawk sounding rocket payloads, are summarized. The MUMP 9 paylaod included an omegatron mass analyzer, a molecular fluorescence densitometer, a mini-tilty filter, and a lunar position sensor. This complement of instruments permitted the determination of the molecular nitrogen density and temperature in the altitude range from approximately 143 to 297 km over Wallops Island, Virginia, during January 1971. The MUMP 10 payload included an omegatron mass analyzer, an electron temperature probe (Spencer, Brace, and Carignan, 1962), a cryogenic densitometer, and a solar position sensor. This complement of instruments permitted the determination of the molecular nitrogen density and temperature and the charged particle density and temperature in the altitude range from approximately 145 to 290 km over Wallops Island, Virginia, during the afternoon preceding the MUMP 9 launch in January 1971. A general description of the payload kinematics, orientation analysis, and the technique for the reduction and analysis of the data is given.

Adaptation of the Nelson-Somogyi reducing-sugar assay to a microassay using microtiter plates.

PubMed

Green, F; Clausen, C A; Highley, T L

1989-11-01

The Nelson-Somogyi assay for reducing sugars was adapted to microtiter plates. The primary advantages of this modified assay are (i) smaller sample and reagent volumes, (ii) elimination of boiling and filtration steps, (iii) automated measurement with a dual-wavelength scanning TLC densitometer, (iv) increased range and reproducibility, and (v) automated colorimetric readings by reflectance rather than absorbance.

Three-Dimensional Computer Graphics Brain-Mapping Project.

DTIC Science & Technology

1987-03-15

NEUROQUANT . This package was directed towards quantitative microneuroanatomic data acquisition and analysis. Using this interface, image frames captured...populations of brains. This would have been aprohibitive task if done manually with a densitometer and film, due to user error and bias. NEUROQUANT functioned...of cells were of interest. NEUROQUANT is presently being implemented with a more fully automatic method of localizing the cell bodies directly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jordan, K; University of Western Ontario, London, ON, CA

Purpose: Film densitometers optimized for radiochromic EBT3 film are not commercially available and flatbed document scanners are limited by broad spectral overlap of the red green and blue channels and polarization effects. Non-polarized, narrow bandwith, intensity stabilized light emitting diode (LED) light sources were constructed and transmission measurements compared for point, slot and full aperture geometries. Methods: LED’s with 10 nm bandwidths were focused to 1 mm spots for point scanning. The LED’s back-illuminated a 6 mm diameter diffuser near the focal point of a 25 cm diameter Fresnel lens for slot and full aperture transmission imaging. Films were locatedmore » at the aperture plane, 15 cm from the lens and imaged with a 16 bit digital camera with 50 mm lens. Sheets, 10×8 cm, were irradiated to 25 Gy with a 4×4 cm 6 MV photon beam. Transmission measurements with a 633nm, linearly polarized laser were used as lowacceptance angle reference geometry. Results: LED intensity stabilized to <1% within one minute of startup. The useful transmission range increased as the acceptance angle decreased, laser(∼2%)> spot(∼3%)> slot(∼5%)> full aperture(∼10%). The Fresnel lens introduced a 4-fold polarization symmetry that increased radially causing a 2% change in transmission at 10 cm from the optic axis for EBT3 film. Polarized spot densitometer and laser transmission were similar. Conclusion: Spectrally filtered LED sources were effective for transmission measurements of radiochromic films. Because of polarization sensitivity of EBT3 film, the scanning spot geometry is the most general for measuring unpolarised transmission of larger film sizes, ie > 15×15 cm. Due to EBT3 film scatter, spot scanning should provide the most accurate profiles of high dose gradients, for a given acceptance angle. The spot scanning densitometer provided useful transmission to ∼5, 25, >25 Gy with 635, 590 and 530 nm light respectively.« less

Measurement of humerus and radius bone mineral content in the term and preterm infant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vyhmeister, N.R.; Linkhart, T.A.

1988-07-01

We compared two anatomic sites for single-photon absorptiometric measurement of bone mineral content (BMC) in term and preterm infants. The distal one third of the radius and the midportion of the humerus were evaluated for measurements of BMC with an unmodified, commercially available bone densitometer. We assessed reproducibility of BMC and bone width (BW) measurements and defined normal at-birth ranges of BMC, BW, and BMC/BW ratio for infants with gestational ages of 24 to 42 weeks. Humerus BMC correlated with gestational age, birth weight, and BW of patients and did not differ from humerus BMC values determined over the samemore » range of gestational ages at another center. Representative serial measurements of two very low birth weight (VLBW) infants are presented to demonstrate the feasibility of using humerus BMC in longitudinal studies to assess changes in bone mineralization. We conclude that bone densitometer measurements of mid-humerus BMC can be successfully performed and are preferable to similar measurements of the radius for VLBW infants. Normal humerus BMC values were defined for use in diagnosis and evaluation of the efficacy of treatment in VLBW infants who are at high risk of developing osteopenia of prematurity.« less

Mouse Models for Bone Research to Assess Military Stress Fracture Risk

DTIC Science & Technology

2005-04-01

analyses. DEXA scanning by PIXImus: The PIXImus densitometer (GE-Lunar, Madison , WI) was used to assess whole body areal (a)BMD and body composition...between sexes in 18 of the 28 strains. Sex differences for whole body BMD (aBMD) and BcD of the lumbar spine are not congruent, consequently predicting...cannot be used to predict aBMD, either whole body or at the lumbar spine, or body cornposition compartments. It is important to note that in this

Visible absorption properties of radiation exposed XR type-T radiochromic film.

PubMed

Butson, Martin J; Cheung, Tsang; Yu, Peter K N

2004-10-07

The visible absorption spectra of Gafchromic XR type-T radiochromic film have been investigated to analyse the dosimetry characteristics of the film with visible light densitometers. Common densitometers can use photospectrometry, fluorescent light (broad-band visible), helium neon (632 nm), light emitting diode (LED) or other specific bandwidth spectra. The visible absorption spectra of this film when exposed to photon radiation show peaks at 676 nm and 618 nm at 2 Gy absorbed doses which shift to slightly lower wavelengths (662 nm and 612 nm at 8 Gy absorbed dose) at higher doses. This is similar to previous models of Gafchromic film such as MD-55-2 and HS but XR type-T also includes a large absorption at lower visible wavelengths due to 'yellow' dyes placed within the film to aid with visible recognition of the film exposure level. The yellow dye band pass is produced at approximately 520 nm to 550 nm and absorbs wavelengths lower than this value within the visible spectrum. This accounts for the colour change from yellow to brown through the added absorption in the red wavelengths with radiation exposure. The film produces a relatively high dose sensitivity with up to 0.25 OD units per Gy change at 672 nm at 100 kVp x-ray energy. Variations in dose sensitivity can be achieved by varying wavelength analysis.

Supine vs decubitus lateral patient positioning in vertebral fracture assessment.

PubMed

Paggiosi, Margaret Anne; Finigan, Judith; Peel, Nicola; Eastell, Richard; Ferrar, Lynne

2012-01-01

In vertebral fracture assessment (VFA), lateral scans are obtained with the patient positioned supine (C-arm densitometers) or lateral decubitus (fixed-arm densitometers). We aimed to determine the impact of positioning on image quality and fracture definition. We performed supine and decubitus lateral VFA in 50 postmenopausal women and used the algorithm-based qualitative method to identify vertebral fractures. We compared the 2 techniques for the identification of fractures (kappa analysis) and compared the numbers of unreadable vertebrae (indiscernible endplates) and vertebrae that were projected obliquely (Wilcoxon matched-pairs signed-rank test). The kappa score for agreement between the VFA techniques (to identify women with vertebral fractures) was 0.84 (95% confidence interval [CI]: 0.68-0.99), and for agreement with fracture assessments made from radiographs, kappa was 0.76 (95% CI: 0.57-0.94) for both supine and decubitus lateral VFA. There were more unreadable vertebrae with supine lateral (48 vertebrae in supine lateral compared with 14 in decubitus lateral; p=0.001), but oblique projection was less common (93 vertebrae compared with 145 in decubitus lateral; p=0.002). We conclude that there were significantly different projection effects with supine and decubitus lateral VFA, but these differences did not influence the identification of vertebral fractures in our study sample. Copyright © 2012 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Proposal to evaluate the use of ERTS-A imagery in mapping and managing soil and range resources in the Sand Hills Region of Nebraska

NASA Technical Reports Server (NTRS)

Drew, J. V. (Principal Investigator)

1973-01-01

The author has identified the following significant results. There appears to be a direct relationship between densitometry values obtained with MSS band 5 imagery and forage density for those range sites measured on the imagery, provided site category identification is indicated by other forms of imagery or ground truth. Overlap of density values for different site categories with differing forage condition classes does not allow assigning a given forage density value for a given densitometer value unless the range site category is known.

A DXA Whole Body Composition Cross-Calibration Experience: Evaluation With Humans, Spine, and Whole Body Phantoms.

PubMed

Krueger, Diane; Libber, Jessie; Sanfilippo, Jennifer; Yu, Hui Jing; Horvath, Blaine; Miller, Colin G; Binkley, Neil

2016-01-01

New densitometer installation requires cross-calibration for accurate longitudinal assessment. When replacing a unit with the same model, the International Society for Clinical Densitometry recommends cross-calibrating by scanning phantoms 10 times on each instrument and states that spine bone mineral density (BMD) should be within 1%, whereas total body lean, fat, and %fat mass should be within 2% of the prior instrument. However, there is limited validation that these recommendations provide adequate total body cross-calibration. Here, we report a total body cross-calibration experience with phantoms and humans. Cross-calibration between an existing and new Lunar iDXA was performed using 3 encapsulated spine phantoms (GE [GE Lunar, Madison, WI], BioClinica [BioClinica Inc, Princeton, NJ], and Hologic [Hologic Inc, Bedford, MA]), 1 total body composition phantom (BioClinica), and 30 human volunteers. Thirty scans of each phantom and a total body scan of human volunteers were obtained on each instrument. All spine phantom BMD means were similar (within 1%; <-0.010 g/cm2 bias) between the existing and new dual-energy X-ray absorptiometry unit. The BioClinica body composition phantom (BBCP) BMD and bone mineral content (BMC) values were within 2% with biases of 0.005 g/cm2 and -3.4 g. However, lean and fat mass and %fat differed by 4.6%-7.7% with biases of +463 g, -496 g, and -2.8%, respectively. In vivo comparison supported BBCP data; BMD and BMC were within ∼2%, but lean and fat mass and %fat differed from 1.6% to 4.9% with biases of +833 g, -860 g, and -1.1%. As all body composition comparisons exceeded the recommended 2%, the new densitometer was recalibrated. After recalibration, in vivo bias was lower (<0.05%) for lean and fat; -23 and -5 g, respectively. Similarly, BBCP lean and fat agreement improved. In conclusion, the BBCP behaves similarly, but not identical, to human in vivo measurements for densitometer cross-calibration. Spine phantoms, despite good

Volumetric and calorimetric properties of aqueous ionene solutions

PubMed Central

Lukšič, Miha; Hribar-Lee, Barbara

2016-01-01

The volumetric (partial and apparent molar volumes) and calorimetric properties (apparent heat capacities) of aqueous cationic polyelectrolyte solutions – ionenes – were studied using the oscillating tube densitometer and differential scanning calorimeter. The polyion’s charge density and the counterion properties were considered as variables. The special attention was put to evaluate the contribution of electrostatic and hydrophobic effects to the properties studied. The contribution of the CH2 group of the polyion’s backbone to molar volumes and heat capacities was estimated. Synergistic effect between polyion and counterions was found. PMID:28503012

Two-phase flow measurements with advanced instrumented spool pieces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turnage, K.C.

1980-09-01

A series of two-phase, air-water and steam-water tests performed with instrumented piping spool pieces is described. The behavior of the three-beam densitometer, turbine meter, and drag flowmeter is discussed in terms of two-phase models. Results from application of some two-phase mass flow models to the recorded spool piece data are shown. Results of the study are used to make recommendations regarding spool piece design, instrument selection, and data reduction methods to obtain more accurate measurements of two-phase flow parameters. 13 refs., 23 figs., 1 tab.

Two-phase flow measurements with advanced instrumented spool pieces and local conductivity probes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turnage, K.G.; Davis, C.E.

1979-01-01

A series of two-phase, air-water and steam-water tests performed with instrumented spool pieces and with conductivity probes obtained from Atomic Energy of Canada, Ltd. is described. The behavior of the three-beam densitometer, turbine meter, and drag flowmeter is discussed in terms of two-phase models. Application of some two-phase mass flow models to the recorded spool piece data is made and preliminary results are shown. Velocity and void fraction information derived from the conductivity probes is presented and compared to velocities and void fractions obtained using the spool piece instrumentation.

JAERI instrumented spool piece performance in two-phase flow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colson, J.B.; Gilbert, J.V.

1979-01-01

Instrumented spool pieces to be installed in horizontal piping on the Cylindrical Core Test Facility (CCTF) at the Japanese Atomic Energy Institute (JAERI) have been designed and tested. The instrumented spool pieces will provide measurements from which mass flow rates can be computed. The primary instruments included in the spool pieces are a full-flow turbine, a full-flow perforated drag plate, and a low energy three-beam photon densitometer. Secondary instruments are provided to measured absolute pressure, fluid temperature, and differential pressure across the full-flow perforated drag plate.

The curvature of sensitometric curves for Kodak XV-2 film irradiated with photon and electron beams.

PubMed

van Battum, L J; Huizenga, H

2006-07-01

Sensitometric curves of Kodak XV-2 film, obtained in a time period of ten years with various types of equipment, have been analyzed both for photon and electron beams. The sensitometric slope in the dataset varies more than a factor of 2, which is attributed mainly to variations in developer conditions. In the literature, the single hit equation has been proposed as a model for the sensitometric curve, as with the parameters of the sensitivity and maximum optical density. In this work, the single hit equation has been translated into a polynomial like function as with the parameters of the sensitometric slope and curvature. The model has been applied to fit the sensitometric data. If the dataset is fitted for each single sensitometric curve separately, a large variation is observed for both fit parameters. When sensitometric curves are fitted simultaneously it appears that all curves can be fitted adequately with a sensitometric curvature that is related to the sensitometric slope. When fitting each curve separately, apparently measurement uncertainty hides this relation. This relation appears to be dependent only on the type of densitometer used. No significant differences between beam energies or beam modalities are observed. Using the intrinsic relation between slope and curvature in fitting sensitometric data, e.g., for pretreatment verification of intensity-modulated radiotherapy, will increase the accuracy of the sensitometric curve. A calibration at a single dose point, together with a predetermined densitometer-dependent parameter ODmax will be adequate to find the actual relation between optical density and dose.

Molecular Genetic and Gene Therapy Studies of the Musculoskeletal System

DTIC Science & Technology

2005-10-01

00 A AA 0 A (C) (D) \\ " 5- Ŕ -.- o 0 AA .0 0 *A 000 L 0 000 SPearson r -0.6401 UW 2 ,_.p=0.0032, n=18 Pearsonr-72 p<O.01, n18 625 650 675 700 72 750...measured by dual-energy X-ray absorptiometry (DEXA) using a reached in the group with PIXImus soft-X-ray densitometer (Lunar, Madison WI) and analysis...dietary and lifestyle factors and their I 1q12-13 with low bone mineral density at the lumbar spine in the association with bone mass in men and women

Scanners for analytic print measurement: the devil in the details

NASA Astrophysics Data System (ADS)

Zeise, Eric K.; Williams, Don; Burns, Peter D.; Kress, William C.

2007-01-01

Inexpensive and easy-to-use linear and area-array scanners have frequently substituted as colorimeters and densitometers for low-frequency (i.e., large area) hard copy image measurement. Increasingly, scanners are also being used for high spatial frequency, image microstructure measurements, which were previously reserved for high performance microdensitometers. In this paper we address characteristics of flatbed reflection scanners in the evaluation of print uniformity, geometric distortion, geometric repeatability and the influence of scanner MTF and noise on analytic measurements. Suggestions are made for the specification and evaluation of scanners to be used in print image quality standards that are being developed.

Excimer Laser Research.

DTIC Science & Technology

1975-08-01

and sample cylinder were repeatedly allowed to outgas at room temperature (under vacuum but valved off) and then cooled with liquid N_ snd pumped...i i I i | I I I I i I i i i | I I i i i i i l i | I l I I I 320 330 340 350 360 E7470 WAVELENGTH (nm) 2 2 Fig. 9 Densitometer Trace of XeF...2, Xs are within 10%. eFor Arl, Nel, NeBr, NeCl, and the helium halides the inert-gas ionization potential is so large that the Coulomb curve does

ADVANCED CUTTINGS TRANSPORT STUDY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stefan Miska; Nicholas Takach; Kaveh Ashenayi

2004-07-31

We have tested the loop elevation system. We raised the mast to approximately 25 to 30 degrees from horizontal. All went well. However, while lowering the mast, it moved laterally a couple of degrees. Upon visual inspection, severe spalling of the concrete on the face of the support pillar, and deformation of the steel support structure was observed. At this time, the facility is ready for testing in the horizontal position. A new air compressor has been received and set in place for the ACTS test loop. A new laboratory has been built near the ACTS test loop Roughened cupsmore » and rotors for the viscometer (RS300) were obtained. Rheologies of aqueous foams were measured using three different cup-rotor assemblies that have different surface roughness. The relationship between surface roughness and foam rheology was investigated. Re-calibration of nuclear densitometers has been finished. The re-calibration was also performed with 1% surfactant foam. A new cuttings injection system was installed at the bottom of the injection tower. It replaced the previous injection auger. A mechanistic model for cuttings transport with aerated mud has been developed. Cuttings transport mechanisms with aerated water at various conditions were experimentally investigated. A total of 39 tests were performed. Comparisons between the model predictions and experimental measurements show a satisfactory agreement. Results from the ultrasonic monitoring system indicated that we could distinguish between different sand levels. We also have devised ways to achieve consistency of performance by securing the sensors in the caps in exactly the same manner as long as the sensors are not removed from the caps. A preliminary test was conducted on the main flow loop at 100 gpm flow rate and 20 lb/min cuttings injection rate. The measured bed thickness using the ultrasonic method showed a satisfactory agreement with nuclear densitometer readings. Thirty different data points were collected after

Method of high-precision microsampled blood and plasma mass densitometry

NASA Technical Reports Server (NTRS)

Hinghofer-Szalkay, H.

1986-01-01

The reliability of the mechanical oscillator technique for blood and plasma density measurements on samples of volumes less than 0.1 ml is examined, and a precision of 0.001 g/l is found if plasma-isodensic heparin solution and siliconized densitometers are employed. Sources of measurement errors in the density determinations include storage of plasma samples, inhomogeneity of blood samples, and density reading before adequate temperature equilibration. In tests of plasma sample storage, the best reproducibility was obtained with samples kept at 4 C. Linear correlations were found between plasma density and plasma protein concentration, blood density and blood hemoglobin concentration, and erythrocyte density and MCHC.

Moon Technology For A New Artform

NASA Technical Reports Server (NTRS)

1979-01-01

The keystone of the density slicing process is an instrument called a densitometer, which can "see" many subtle gradations not visible to the human eye. This instrument was integrated into a computerized system which analyzed the tonal density of a moon photo, assigned a color code to each of the various shades, and created on a video monitor a new picture in which each color represented a particular measurement, such as height or depth. Density slicing, applied to telescopic photos and later to close-up views acquired by unmanned spacecraft, provided the foundation for NASA's extensive study and selection of safe Apollo landing sites.

Comparison of instruments for dual-energy X-ray bone mineral densitometry.

PubMed

Vainio, P; Ahonen, E; Leinonen, K; Sievänen, H; Koski, E

1992-04-01

While bone mineral densitometry has become a common laboratory test, it is important to pay attention to the compatibility of the results from different instruments. In this study results from three commercially available bone densitometers are compared using both patient and phantom studies. Overall correlation between instruments was good but there were systematic discrepancies in the results. The three instruments provided bone mineral density (BMD) values that differed by as much as 13.5% due to differences as large as 6% in bone mineral content and as large as 7% in bone area. Thus, the BMD values obtained from different manufacturers' instruments are not directly comparable.

Express immunochromatographic detection of antibodies against Brucella abortus in cattle sera based on quantitative photometric registration and modulated cut-off level.

PubMed

Sotnikov, Dmitriy V; Byzova, Nadezhda A; Zherdev, Anatoly V; Eskendirova, Saule Z; Baltin, Kairat K; Mukanov, Kasim K; Ramankulov, Erlan M; Sadykhov, Elchin G; Dzantiev, Boris B

2015-01-01

An immunochromatographic test system was developed for rapid detection of the levels of specific IgG antibodies to Brucella abortus lipopolysaccharide, as a tool for diagnosis of brucellosis in cattle. The pilot test strips were examined using blood sera from sick (78 samples) and healthy (35 samples) cows. The results obtained by immunochromatographic assay, using a portable optical densitometer for digital video detection, correlate well with the results obtained by immunoenzyme assay and are in agreement with the results of the disease diagnosis. The new test system allows detection of antibodies within 10 min and can be proposed as an alternative to the methods available for serodiagnosis of brucellosis.

The use of near-infrared photography for biodegradable pollution monitoring of tidal rivers

NASA Technical Reports Server (NTRS)

Bressette, W. E.; Lear, D. E., Jr.

1973-01-01

On October 2, 1972, a pattern of chlorophyll a containing phytoplankton (algae) was detected from 3-km altitude in a series of near-infrared photographs of the Potomac River 'Salt Wedge Area.' Densitometer traces over the film images, related to in situ measurements of chlorophyll a concentrations that varied from 4 to more than 3000 micrograms/liter, revealed a phytoplankton 'bloom' threshold in the near infrared between the concentration of 34 and 51 micrograms/liter. The photography also revealed bottom features through two meters of water and made it possible to integrate chlorophyll a concentrations over a 16 sq km area to demonstrate this remote sensing technique for biodegradable pollution monitoring.

Prevalence of low bone health using quantitative ultrasound in Indian women aged 41-60 years: Its association with nutrition and other related risk factors.

PubMed

Shenoy, Shweta; Chawla, Jasmine Kaur; Gupta, Swati; Sandhu, Jaspal Singh

2017-01-01

The purpose of this study was to find the prevalence of low bone health conditions and assess associated nutritional and other risk factors in Indian women aged 41-60 years. A total of 1,911 women participated in this cross-sectional study. Bone health was assessed using an Omnisense multisite quantitative ultrasound bone densitometer on two sites (radius and tibia). Crude prevalence of osteopenia and osteoporosis was found to be 30.09% and 19.89%, respectively. The Indian women were deficient in a majority of nutrients. Postmenopause, hysterectomy, hyperthyroid, hypothyroid, hypertension, low physical activity, low sun exposure, high stress levels, and low calcium levels were found to be independent risk factors of low bone health.

Aerial photographic water color variations from the James River

NASA Technical Reports Server (NTRS)

Bressette, W. E.

1979-01-01

Photographic flights from 305 meters altitude were made throughout the day of May 17, 1977, over seven water data stations in the James River. The flights resulted in wide-angle, broadband, spectral radiance film exposure data between the wavelengths of 500 to 900 nanometers for sun elevation angles ranging from 37 to 64 deg and variable atmospheric haze conditions. It is shown from densitometer data that: (1) the dominant observed color from James River waters is determined by the optical properties of the total suspended solid load, (2) variability in observed color is produced by a changing solar elevation angle; and (3) the rate at which observed color changes is influenced by both solar elevation angle and atmospheric conditions.

21 CFR 862.2400 - Densitometer/scanner (integrating, reflectance, TLC, or radiochromatogram) for clinical use.

Code of Federal Regulations, 2013 CFR

2013-04-01

... ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND... element on a radiochromatogram. (b) Classification. Class I (general controls). The device is exempt from...

21 CFR 862.2400 - Densitometer/scanner (integrating, reflectance, TLC, or radiochromatogram) for clinical use.

Code of Federal Regulations, 2012 CFR

2012-04-01

... ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND... element on a radiochromatogram. (b) Classification. Class I (general controls). The device is exempt from...

21 CFR 862.2400 - Densitometer/scanner (integrating, reflectance, TLC, or radiochromatogram) for clinical use.

Code of Federal Regulations, 2014 CFR

2014-04-01

... ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND... element on a radiochromatogram. (b) Classification. Class I (general controls). The device is exempt from...

Development of a simplified densitometer for the determination of aflatoxins by thin-layer chromatography.

PubMed

Stroka, J; Anklam, E

2000-12-29

A simple, miniaturised and low power consuming (battery, fully semiconductor based) detector cell (SeBaDeC) was developed for the densitometric measurement of aflatoxins on TLC plates. A UV-light emitting diode (UV-LED) with a peak emission wavelength of 370 nm was used for fluorescence excitation, while a photo diode with a peak sensitivity of 440 nm in combination with a 418 nm cut-off filter was applied for detecting the fluorescence intensity. The resulting signal was further amplified by means of a commonly used operational amplifier integrated circuit (OA) and directly converted into a digital signal with a simple analogue-digital-converter (ADC). This signal was recorded at the serial (RS232) port of a portable PC and processed with a spreadsheet program. The software used for data recording is freeware and available in its source code, and the long lifetime of the UV-LED (up to 10 000 h) permits a maintenance free application of this device. This simplified device has shown to be able to detect concentrations of aflatoxins of 1 ng, thus offering a cheap and sensitive alternative to currently available TCL scanners.

Stiles—Crawford effect and the bleaching of cone pigments

PubMed Central

Coble, J. R.; Rushton, W. A. H.

1971-01-01

1. The efficiency of light entering the eye through various points in the pupil (Stiles—Crawford effect) was studied using two criteria: (a) visual brightness judged by flicker fusion and (b) the rate of cone pigment bleaching measured by reflexion densitometry. 2. Both measurements were made in the same apparatus with the same geometry of presentation and both gave the same Stiles—Crawford effect. 3. This suggests that the densitometer measures pigment deep in the outer segments of the cones where light is absorbed for vision. 4. Foveal cones seem all to point in the same direction, since the fraction of pigment bleached by light entering the pupil at any one point is the same when measured by light entering anywhere. PMID:5571926

Monitoring the growth or decline of vegetation on mine dumps

NASA Technical Reports Server (NTRS)

Gilbertson, B. P. (Principal Investigator)

1975-01-01

The author has identified the following signficant results. It was established that particular mine dumps throughout the entire test area can be detected and identified. It was also established that patterns of vegetative growth on the mine dumps can be recognized from a simple visual analysis of photographic images. Because vegetation tends to occur in patches on many mine dumps, it is unsatisfactory to classify complete dumps into categories of percentage vegetative cover. A more desirable approach is to classify the patches of vegetation themselves. The coarse resolution of conventional densitometers restricts the accuracy of this procedure, and consequently a direct analysis of ERTS CCT's is preferred. A set of computer programs was written to perform the data reading and manipulating functions required for basic CCT analysis.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Jay; Harris, Tequila

A novel bidirectional thickness profilometer based on transmission densitometry was designed to measure the localized thickness of semitransparent films on a dynamic manufacturing line. The densitometer model shows that, for materials with extinction coefficients between 0.3 and 2.9 D/mm, 100-500 {mu}m measurements can be recorded with less than {+-}5% error at more than 10,000 locations in real time. As a demonstration application, the thickness profiles of 75 mmx100 mm regions of polymer electrolyte membrane (PEM) were determined by converting the optical density of the sample to thickness with the Beer-Lambert law. The PEM extinction coefficient was determined to be 1.4more » D/mm, with an average thickness error of 4.7%.« less

SU-D-213-07: Initial Characterization of a Gel Patch Dosimeter for in Vivo Dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matrosic, C; Culberson, W; Rosen, B

Purpose: In vivo dosimetry, despite being the most direct method for monitoring the dose delivered during radiation therapy and being recommended by several national and international organizations (AAPM, ICRU, NACP), is underutilized in the clinic due to issues associated with dose sensitivity, feasibility, and cost. Given the increasing complexity of radiation therapy modern treatments, there is a compelling need for a robust, affordable in vivo dosimetry option. In this work we present the initial characterization of a novel gel patch in vivo dosimeter. Methods: DEFGEL (6%T) was used to make 1-cm thick small cylindrical patch dosimeters. The optical density ofmore » each dosimeter was read before and after irradiation by an in-house laser densitometer. The dosimeters were irradiated using a Varian Clinac EX linac. Three separate batches of gel patches were used to create dose response curves and evaluate repeatability. The development time of the dosimeter was also evaluated. Results: The dose response of the dosimeter was found to be linear from a range of approximately 1-Gy to 20-Gy, which is a larger window of linearity compared to other in vivo dosimeters. At doses below 1-Gy, the cumulative uncertainties were on the order of the measured data. When compared, the three batches demonstrated repeatability from 1-Gy to approximately 13-Gy, with some variation at higher doses. For doses of >8-Gy, the dosimeter reached full optical density after 4-hours, whereas low doses developed within an hour. Conclusion: Initial results indicate that the gel patch dosimeter is a reliable and simple way to measure a large range of doses, including high doses such as those delivered during hypofractionated treatments (e.g. SBRT or MR-guided radiotherapy). The simple fabrication method for the dosimeter and the use of a laser densitometer would allow for the dosimeter to used and read in-house, cheaply and easily.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lynch, Bart D.; Kozelka, Jakub; Ranade, Manisha K.

In this study, we present three significant artifacts that have the potential to negatively impact the accuracy and precision of film dosimetry measurements made using GAFCHROMIC[reg] EBT radiochromic film when read out with CCD flatbed scanners. Films were scanned using three commonly employed instruments: a Macbeth TD932 spot densitometer, an Epson Expression 1680 CCD array scanner, and a Microtek ScanMaker i900 CCD array scanner. For the two scanners we assessed the variation in optical density (OD) of GAFCHROMIC EBT film with scanning bed position, angular rotation of the film with respect to the scan line direction, and temperature inside themore » scanner due to repeated scanning. Scanning uniform radiochromic films demonstrated a distinct bowing effect in profiles in the direction of the CCD array with a nonuniformity of up to 17%. Profiles along a direction orthogonal to the CCD array demonstrated a 7% variation. A strong angular dependence was found in measurements made with the flatbed scanners; the effect could not be reproduced with the spot densitometer. An IMRT quality assurance film was scanned twice rotating the film 90 deg. between the scans. For films scanned on the Epson scanner, up to 12% variation was observed in unirradiated EBT films rotated between 0 deg. and 90 deg. , which decreased to approximately 8% for EBT films irradiated to 300 cGy. Variations of up to 80% were observed for films scanned with the Microtek scanner. The scanners were found to significantly increase the film temperature with repeated scanning. Film temperature between 18 and 33 deg. C caused OD changes of approximately 7%. Considering these effects, we recommend adherence to a strict scanning protocol that includes: maintaining the orientation of films scanned on flatbed scanners, limiting scanning to the central portion of the scanner bed, and limiting the number of consecutive scans to minimize changes in OD caused by film heating.« less

Spatially balanced provision of health equipment: a cross-sectional study oriented to the identification of challenges to access promotion.

PubMed

Amaral, Pedro Vasconcelos; Rocha, Thiago Augusto Hernandes; Barbosa, Allan Claudius Queiroz; Lein, Adriana; Vissoci, João Ricardo Nickenig

2017-12-04

Access to health services is in part defined by the spatial distribution of healthcare equipment. To ensure equity in the provision of health services, it is important to examine availability across different health care providers taking into account population demand. Given the importance of the equitable provision of health equipment, we evaluate its spatial distribution in Brazil. This study is classified as cross-sectional with an ecological design. We evaluate Brazilian data on distance to available health equipment considering: dialysis machines (385), magnetic resonance imaging (MRI) (257), hospital beds (3675) and bone densitometers (429). We define two distance thresholds (50 km and 200 km) from a municipality to the center of services provision. The balance between infrastructure capacity and potential demand was evaluated to identify a lack or surplus of health services. The distribution of dialysis equipment and bone densitometers is not balanced across Brazilian states, and unmet demand is high. With respect to MRIs, the large capacity of this equipment results in a large excess of supply. However, this characteristic alone cannot account for excesses of supply of over 700%, as is the case of the Federal District when the range is limited to 50 km. At the same time, four states in the Northeastern region of Brazil show a net excess of demand. Some regions do not meet the standard amount of supply defined by Brazilian Ministry of Health. The quantity and distribution of hospital beds are not sufficient to provide full coverage to the population. Our main focus was to evaluate the network of the provision of health equipment in Brazil, considering both private and public sectors conjointly. We take into account two main aspects of a spatially balanced health system: the regional availability of health equipment and the geographic distance between its demand and supply at the municipality level. Some regions do not meet the minimum requirement defined

Thermal and Electrical Characterization of Alumina Substrate for Microelectronic Applications

NASA Astrophysics Data System (ADS)

Ahmad, S.; Ibrahim, A.; Alias, R.; Shapee, S. M.; Ambak, Z.; Zakaria, S. Z.; Yahya, M. R.; Mat, A. F. A.

2010-03-01

This paper reports the effect of sintering temperature on thermal and electrical properties of alumina material as substrate for microelectronic devices. Alumina materials in the form of green sheet with 1 mm thickness were sintered at 1100° C, 1300° C and 1500° C for about 20 hours using heating and cooling rates of 2° C/min. The densities were measured using densitometer and the microstructures of the samples were analyzed using SEM micrographs. Meanwhile thermal and electrical properties of the samples were measured using flash method and impedance analyzer respectively. It was found that thermal conductivity and thermal diffusivity of the substrate increases as sintering temperature increases. It was found also that the dielectric constant of alumina substrate increases as the sintering temperature increases.

Remote sensing of effects of land-use practices on water quality. [environmental surveys using Landsat satellites

NASA Technical Reports Server (NTRS)

Graves, D. H.

1975-01-01

Research efforts are presented for the use of remote sensing in environmental surveys in Kentucky. Ground truth parameters were established that represent the vegetative cover of disturbed and undisturbed watersheds in the Cumberland Plateau of eastern Kentucky. Several water quality parameters were monitored of the watersheds utilized in the establishment of ground truth data. The capabilities of multistage-multispectral aerial photography and satellite imagery were evaluated in detecting various land use practices. The use of photographic signatures of known land use areas utilizing manually-operated spot densitometers was studied. The correlation of imagery signature data to water quality data was examined. Potential water quality predictions were developed from forested and nonforested watersheds based upon the above correlations. The cost effectiveness of predicting water quality values was evaluated using multistage and satellite imagery sampling techniques.

Gadolinium concentration analysis in brain phantom by X-ray fluorescence.

PubMed

Almalki, Musaed; Majid, Samir Abdul; Butler, Philip H; Reinisch, Lou

2010-06-01

We have measured the X-ray fluorescence from gadolinium as a function of concentration and position in tumors of different sizes and shapes in a head phantom. The gadolinium fluorescence was excited with a 36 GBq Am-241 source. The fluorescence signal was detected with a CdTe detector and a multi-channel analyzer. The fluorescence peak was clearly separated from the scattered X-rays. Concentrations of 5.62-78.63 mg/ml of Gd ion were used in 1, 2, and 3 cm diameter spherical tumors and a 2x4 cm oblate spheroid tumor. The data show trends approaching saturation for the highest concentrations, probably due to reabsorption in the tumor. A comparison of X-ray photographic imaging and densitometer measurements to determine concentration is also presented.

In vivo modulation of androgen receptor by androgens.

PubMed

Kumar, V L; Majumder, P K; Kumar, V

2002-09-01

To study the effect of androgen and antiandrogen on the level of androgen receptor (AR) mRNA. The total RNA was extracted from the prostate and analyzed by slot blot analysis. The blots were hybridized with AR cDNA probe and 1A probe (internal control) and autoradiography was performed. The intensity of signal was measured with a densitometer and the ratio of AR RNA and 1A RNA was calculated. Androgenic deprivation produced by castration decreased the weight of the prostate and increased the levels of AR mRNA. Treatment of the castrated rats with testostrone increased the weight of prostate and decreased the levels of AR mRNA. Treatment of normal rats with flutamide decreased the weight of the gland and increased the levels of AR mRNA. Androgens produce proliferative effect on the prostate and negatively regulate the AR transcription.

Modifying a Rodenstock scanning laser ophthalmoscope for imaging densitometry.

PubMed

Tornow, R P; Beuel, S; Zrenner, E

1997-08-01

The necessary modifications and technical requirements are described for using a commercially available scanning laser ophthalmoscope (Rodenstock Model 101 SLO) as an imaging densitometer to assess human photopigment distribution. The main requirements are a linear detector amplifier, fast shutters for the laser beams, and a trigger unit. Images must be compensated for varying laser intensity. Both rod and cone photopigments are measured with the 514-nm argon laser of the SLO. Discrimination is possible owing to the different spatial distribution. The cone pigment density peaks in the foveal center (D = 0.40) with a steep decrease with increasing eccentricity E (full width at half-maximum, 2.5 degrees ). Rod photopigment increases with increasing eccentricity (D = 0.23 for E = 11 degrees ). These values are in agreement with previous reported results obtained with scanning laser ophthalmoscopes specially designed for retinal densitometry and high stability.

Computer synthesis of high resolution electron micrographs

NASA Technical Reports Server (NTRS)

Nathan, R.

1976-01-01

Specimen damage, spherical aberration, low contrast and noisy sensors combine to prevent direct atomic viewing in a conventional electron microscope. The paper describes two methods for obtaining ultra-high resolution in biological specimens under the electron microscope. The first method assumes the physical limits of the electron objective lens and uses a series of dark field images of biological crystals to obtain direct information on the phases of the Fourier diffraction maxima; this information is used in an appropriate computer to synthesize a large aperture lens for a 1-A resolution. The second method assumes there is sufficient amplitude scatter from images recorded in focus which can be utilized with a sensitive densitometer and computer contrast stretching to yield fine structure image details. Cancer virus characterization is discussed as an illustrative example. Numerous photographs supplement the text.

Thermal indicating paints for ammunition health monitoring

NASA Astrophysics Data System (ADS)

Zunino, James L., III; Iqbal, Zafar

2010-04-01

Thermochromic semiconductive polymers that change color in response to external stimuli, such as heat and radiation, can be utilized to monitor the temperature range and elapsed time profiles of stored and prepositioned munitions. These polymers are being tailored to create paints and coatings that will alert Army logistic staff of dangerous temperature exposures. Irreversible indication via color change in multiple thermal bands, 145 F - 164 F (63o-73°C), 165 F - 184 F (74° - 84° C) and over 185 F (>85°C) are possible with these thermochromic polymers. The resulting active coating can be visually inspected to determine if safe temperatures were exceeded. More detailed information, including cumulative time of exposure in certain temperature bands through changes in optical chromaticity describing the vividness or dullness of a color, can be assessed using a hand-held optical densitometer.

The Prevalence of Osteopenia and Osteoporosis Among Malaysian Type 2 Diabetic Patients Using Quantitative Ultrasound Densitometer

PubMed Central

Abdulameer, Shaymaa Abdalwahed; Sahib, Mohanad Naji; Sulaiman, Syed Azhar Syed

2018-01-01

Background: Type 2 Diabetes Mellitus (T2DM) and osteoporosis are both chronic conditions and the relationship between them is complex. Objective: The aims of this study were to assess the prevalence of Low Bone Mineral density (LBMD, i.e., osteopenia and osteoporosis), as well as, the difference and associations between Quantitative Ultrasound Scan (QUS) parameters with socio-demographic data and clinical related data among T2DM in Penang, Malaysia. Method: An observational, cross-sectional study with a convenient sample of 450 T2DM patients were recruited from the outpatient diabetes clinic at Hospital Pulau Pinang (HPP) to measure Bone Mineral Density (BMD) at the heel bone using QUS. In addition, a self-reported structured questionnaire about the socio-demographic data and osteoporosis risk factors were collected. Moreover, the study included the retrospective collection of clinical data from patients’ medical records. Results: The mean value of T-score for normal BMD, osteopenic and osteoporotic patients’ were (-0.41±0.44), (-1.65±0.39) and (-2.76±0.27), respectively. According to QUS measurements, more than three quarters of T2DM patients (82%) were at high risk of abnormal BMD. The results showed that QUS scores were significantly associated with age, gender, menopausal duration, educational level and diabetic related data. Moreover, the QUS parameters and T-scores demonstrated significant negative correlation with age, menopausal duration, diabetic duration and glycaemic control, as well as, a positive correlation with body mass index and waist to hip ratio. The current study revealed that none of the cardiovascular disease risk factors appear to influence the prevalence of low BMD among T2DM Malaysian patients. Conclusion: The study findings revealed that the assessment of T2DM patients’ bone health and related factor are essential and future educational programs are crucial to improve osteoporosis management. PMID:29755605

Recent development of radiation measurement instrument for industrial and medical applications

NASA Astrophysics Data System (ADS)

Baba, Sueki; Ohmori, Koichi; Mito, Yoshio; Tanoue, Toshiya; Yano, Shigeki; Tokumori, Kenji; Toyofuku, Fukai; Kanda, Shigenobu

2001-02-01

Recently, computer imaging technology has developed very high-quality image and fast processing time. X-rays have been used for many purposes such as medical diagnosis and analyzing the structure of industrial materials. However, as X-rays are hazardous to the human body, it is desirable to reduce its exposed dose to a minimum. For this purpose, it is necessary to use a semiconductor radiation detector with a high efficiency for X-rays. We have developed photon-counting CdTe array detector system for medical and industrial use. The bone densitometer for Dual Energy X-ray Absorptometry (DEXA) has been developed to make diagnosis of osteoporosis, and it is developed to analyze a material element for industrial use. Recently, we have developed a monochromatic X-ray CT using a 256 ch CdTe array detector. We found that the array detector systems are very useful for medical and industrial applications.

LANDSAT applications to wetlands classification in the upper Mississippi River Valley. Ph.D. Thesis. Final Report

NASA Technical Reports Server (NTRS)

Lillesand, T. M.; Werth, L. F. (Principal Investigator)

1980-01-01

A 25% improvement in average classification accuracy was realized by processing double-date vs. single-date data. Under the spectrally and spatially complex site conditions characterizing the geographical area used, further improvement in wetland classification accuracy is apparently precluded by the spectral and spatial resolution restrictions of the LANDSAT MSS. Full scene analysis of scanning densitometer data extracted from scale infrared photography failed to permit discrimination of many wetland and nonwetland cover types. When classification of photographic data was limited to wetland areas only, much more detailed and accurate classification could be made. The integration of conventional image interpretation (to simply delineate wetland boundaries) and machine assisted classification (to discriminate among cover types present within the wetland areas) appears to warrant further research to study the feasibility and cost of extending this methodology over a large area using LANDSAT and/or small scale photography.

Experimental investigation on densification behavior and surface roughness of AlSi10Mg powders produced by selective laser melting

NASA Astrophysics Data System (ADS)

Wang, Lin-zhi; Wang, Sen; Wu, Jiao-jiao

2017-11-01

Effects of laser energy density (LED) on densities and surface roughness of AlSi10Mg samples processed by selective laser melting were studied. The densification behaviors of the SLM manufactured AlSi10Mg samples at different LEDs were characterized by a solid densitometer, an industrial X-ray and CT detection system. A field emission scanning electron microscope, an automatic optical measuring system, and a surface profiler were used for measurements of surface roughness. The results show that relatively high density can be obtained with the point distance of 80-105 μm and the exposure time of 140-160 μs. The LED has an important influence on the surface morphology of the forming part, too high LED may lead to balling effect, while too low LED tends to produce defects, such as porosity and microcrack, and then affect surface roughness and porosities of the parts finally.

The utilization of false color aerial photography for macrophyte biomass estimation in the Oosterschelde (the Netherlands)

NASA Astrophysics Data System (ADS)

Meulstee, C.; Vanstokkom, H.

1985-01-01

The correlation between the biomass of sea grass and seaweed samples in a sidebranch of the Oosterschelde delta (Netherlands) and density ratios of this area on color infrared aerial photographs was investigated. As the Oosterschelde will become more divided from the North Sea after pier dam completion, an increase of macrophytes is expected. In an area where the weeds Ulva, Cheatomorpha, Entermorpha, Cladophora, Fucus vesuculosis, and the grasses Zostera noltii and Zostera marina are found, 53 biomass samples of a 0.054 sq m surface each were collected. The relation between covering degree and biomass was estimated. Using a transmission-densitometer adjusted to 3 to 1 mm, densities on 1:10,000 and 1:20,000 scale photographs were measured. A gage line was determined in a density-biomass diagram. The method is shown to be useful for an efficient, accurate biomass determination in the Oosterschelde.

Prevalence of osteoporosis and osteopenia in advanced chronic obstructive pulmonary disease patients.

PubMed

Bhattacharyya, Parthasarathi; Paul, Rantu; Ghosh, Malabika; Dey, Ratna; Dey, Rana; Barooah, Nirjoo; Islam, Saidul; Acharya, Dipabali; Nag, Saikat; Bardhan, Sujan

2011-07-01

Reduction of bone mineral density (BMD) is a known and established phenomenon in chronic obstructive pulmonary disease (COPD). However, there have been no data regarding osteoporosis/osteopenia in COPD patients in India. To look for the degree and frequency of osteoporosis/osteopenia in our OPD patients being diagnosed as COPD. Thirty-seven randomly selected patients with COPD were assessed for BMD with commercially available ultrasound bone densitometer (HOLOGIC SAHARA) in a pulmonary OPD. Some cofactors for reduced BMD were also noted. Out of the 37 COPD (all belonging to the GOLD III/IV category) patients studied, the BMD was found to be normal in 10 (27%) patients, while 27 (73%) patients were found to have osteopenia/osteoporosis [19 (51.35%) and 8 (21.62%) patients having osteopenia and osteoporosis, respectively]. Frequency of osteoporosis and osteopenia was found to be very high (73%) in our population of advanced COPD. The data suggest a need for further in-depth study regarding the issue.

A comparison of five methods for monitoring the precision of automated x-ray film processors.

PubMed

Nickoloff, E L; Leo, F; Reese, M

1978-11-01

Five different methods for preparing sensitometric strips used to monitor the precision of automated film processors are compared. A method for determining the sensitivity of each system to processor variations is presented; the observed statistical variability is multiplied by the system response to temperature or chemical changes. Pre-exposed sensitometric strips required the use of accurate densitometers and stringent control limits to be effective. X-ray exposed sensitometric strips demonstrated large variations in the x-ray output (2 omega approximately equal to 8.0%) over a period of one month. Some light sensitometers were capable of detecting +/- 1.0 degrees F (+/- 0.6 degrees C) variations in developer temperature in the processor and/or about 10.0 ml of chemical contamination in the processor. Nevertheless, even the light sensitometers were susceptible to problems, e.g. film emulsion selection, line voltage variations, and latent image fading. Advantages and disadvantages of the various sensitometric methods are discussed.

Blast-wave density measurements

NASA Astrophysics Data System (ADS)

Ritzel, D. V.

Applications of a densitometer to obtain time-resolved data on the total density in blast-wave flows are described. A beta-source (promethium-147) is separated by a gap from a scintillator and a photomultiplier tube (PMT). Attenuation of the radiation beam by the passing blast wave is due to the total density in the gap volume during the wave passage. Signal conditioning and filtering methods permit the system to output linearized data. Results are provided from use of the system to monitor blast waves emitted by detonation of a 10.7 m diameter fiberglass sphere containing 609 tons of ammonium nitrate/fuel oil at a 50.6 m height. Blast wave density data are provided for peak overpressure levels of 245, 172 and 70 kPa and distances of 183, 201 and 314 m from ground zero. Data resolution was of high enough quality to encourage efforts to discriminate dust and gasdynamic phenomena within passing blast waves.

Interpretive Reporting of Protein Electrophoresis Data by Microcomputer

PubMed Central

Talamo, Thomas S.; Losos, Frank J.; Kessler, G. Frederick

1982-01-01

A microcomputer based system for interpretive reporting of protein electrophoretic data has been developed. Data for serum, urine and cerebrospinal fluid protein electrophoreses as well as immunoelectrophoresis can be entered. Patient demographic information is entered through the keyboard followed by manual entry of total and fractionated protein levels obtained after densitometer scanning of the electrophoretic strip. The patterns are then coded, interpreted, and final reports generated. In most cases interpretation time is less than one second. Misinterpretation by computer is uncommon and can be corrected by edit functions within the system. These discrepancies between computer and pathologist interpretation are automatically stored in a data file for later review and possible program modification. Any or all previous tests on a patient may be reviewed with graphic display of the electrophoretic pattern. The system has been in use for several months and is presently well accepted by both laboratory and clinical staff. It also allows rapid storage, retrieval and analysis of protein electrophoretic datab.

Monitoring of multiphase flows for superconducting accelerators and others applications

NASA Astrophysics Data System (ADS)

Filippov, Yu. P.; Kakorin, I. D.; Kovrizhnykh, A. M.; Miklayev, V. M.

2017-07-01

This paper is a review on implementation of measuring systems for two-phase helium, hydrogen, liquefied natural gas (LNG), and oil-formation/salty water flows. Two types of such systems are presented. The first type is based on two-phase flow-meters combining void fraction radio-frequency (RF) sensors and narrowing devices. They can be applied for superconducting accelerators cooled with two-phase helium, refueling hydrogen system for space ships and some applications in oil production industry. The second one is based on combination of a gamma-densitometer and a narrowing device. These systems can be used to monitor large two-phase LNG and oil-formation water flows. An electronics system based on a modular industrial computer is described as well. The metrological characteristics for different flow-meters are presented and the obtained results are discussed. It is also shown that the experience gained allows separationless flow-meter for three-phase oil-gas-formation water flows to be produced.

Applied photo interpretation for airbrush cartography

NASA Technical Reports Server (NTRS)

Inge, J. L.; Bridges, P. M.

1976-01-01

Lunar and planetary exploration has required the development of new techniques of cartographic portrayal. Conventional photo-interpretive methods employing size, shape, shadow, tone, pattern, and texture are applied to computer-processed satellite television images. Comparative judgements are affected by illumination, resolution, variations in surface coloration, and transmission or processing artifacts. The portrayal of tonal densities in a relief illustration is performed using a unique airbrush technique derived from hill-shading of contour maps. The control of tone and line quality is essential because the mid-gray to dark tone densities must be finalized prior to the addition of highlights to the drawing. This is done with an electric eraser until the drawing is completed. The drawing density is controlled with a reflectance-reading densitometer to meet certain density guidelines. The versatility of planetary photo-interpretive methods for airbrushed map portrayals is demonstrated by the application of these techniques to the synthesis of nonrelief data.

Crop identification and acreage measurement utilizing ERTS imagery

NASA Technical Reports Server (NTRS)

Vonsteen, D. H. (Principal Investigator)

1972-01-01

There are no author-identified significant results in this report. The microdensitometer will be used to analyze data acquired by ERTS-1 imagery. The classification programs and software packages have been acquired and are being prepared for use with the information as it is received. Photo and digital tapes have been acquired for coverage of virtually 100 percent of the test site areas. These areas are located in South Dakota, Idaho, Missouri, and Kansas. Hass 70mm color infrared, infrared, black and white high altitude aerial photography of the test sites is available. Collection of ground truth for updating the data base has been completed and a computer program written to count the number of fields and give total acres by size group for the segments in each test site. Results are given of data analysis performed on digitized data from densitometer measurements of fields of corn, sugar, beets, and alfalfa in Kansas.

Comparison of conventional and digital radiography for radiometric differentiation of dental cements.

PubMed

Baksi, B Güniz; Ermis, R Banu

2007-10-01

To test the efficacy of conventional radiometry with indirect digital image analysis in the assessment of the relative radiopacity of dental cements used as liners or bases compared to human enamel and dentin. Disks of 15 different dental cements, 5 mm in diameter and 2 mm thick, were exposed to radiation together with 2-mm-thick disks of enamel and dentin and an aluminum step wedge. Density was evaluated by digital transmission densitometry and with the histogram function of an image analysis program following digitization of the radiographs with a flatbed scanner. A higher number of dental cements were discriminated from both dentin and enamel with conventional radiographic densitometer. All the cements examined, except Ionoseal (Voco) and Ionobond (Voco), were more radiopaque than dentin. With both methods, Chelon-Silver (3M ESPE) had the highest radiopacity and glass-ionomer cements the lowest. Radiodensity of dental cements can be differentiated with a high probability with the conventional radiometric method.

Measurements of ultrasonic backscattered spectral centroid shift from spine in vivo: methodology and preliminary results.

PubMed

Garra, Brian S; Locher, Melanie; Felker, Steven; Wear, Keith A

2009-01-01

Ultrasonic backscatter measurements from vertebral bodies (L3 and L4) in nine women were performed using a clinical ultrasonic imaging system. Measurements were made through the abdomen. The location of a vertebra was identified from the bright specular reflection from the vertebral anterior surface. Backscattered signals were gated to isolate signal emanating from the cancellous interiors of vertebrae. The spectral centroid shift of the backscattered signal, which has previously been shown to correlate highly with bone mineral density (BMD) in human calcaneus in vitro, was measured. BMD was also measured in the nine subjects' vertebrae using a clinical bone densitometer. The correlation coefficient between centroid shift and BMD was r = -0.61. The slope of the linear fit was -160 kHz / (g/cm(2)). The negative slope was expected because the attenuation coefficient (and therefore magnitude of the centroid downshift) is known from previous studies to increase with BMD. The centroid shift may be a useful parameter for characterizing bone in vivo.

California coast nearshore processes study

NASA Technical Reports Server (NTRS)

Pirie, D. M. (Principal Investigator)

1972-01-01

The author has identified the following significant results. In the Santa Barbara Channel the effect of the California and the Anacapa Currents are clearly seen in image 1109-18073M. The large triangular shaped lobe of suspended particulate matter that stretches almost to Anacapa Island from the Ventura River area is disrupted approximately midchannel by the east-moving Anacapa Current. In the Point Conception area a lobe of suspended material approximately 20 miles long can be seen moving eastward as a result of the California Current. In the San Francisco Bay area the major results include the detection and delineation of the San Francisco Bay, the location and vector of suspended sediment in the San Francisco Bay, and the ability to differentiate morphologic units within the San Francisco Bay tidelands. Several densitometer line traces seaward of the Golden Gate Bridge on image 1075-18173-4 outline the San Francisco Bay and give evidence of good water penetration.

Quantitative Determination of Photosynthetic Pigments in Green Beans Using Thin-Layer Chromatography and a Flatbed Scanner as Densitometer

ERIC Educational Resources Information Center

Valverde, Juan; This, Herve; Vignolle, Marc

2007-01-01

A simple method for the quantitative determination of photosynthetic pigments extracted from green beans using thin-layer chromatography is proposed. Various extraction methods are compared, and it is shown how a simple flatbed scanner and free software for image processing can give a quantitative determination of pigments. (Contains 5 figures.)

Initial Characterization of a Gel Patch Dosimeter for In Vivo Dosimetry

PubMed Central

Matrosic, C; Culberson, W; Rosen, B; Madsen, E; Frank, G; Bednarz, B

2016-01-01

In vivo dosimetry is a greatly underutilized tool for patient safety in clinical external beam radiotherapy treatments, despite being recommended by several national and international organizations (AAPM, ICRU, IAEA, NACP). The reasons for this underutilization mostly relate to the feasibility and cost of in vivo dosimetry methods. Due to the increase in the number of beam angles and dose per fraction in modern treatments, there is a compelling need for a novel dosimeter that is robust and affordable while able to operate properly in these complex conditions. This work presents a gel patch dosimeter as a novel method of in vivo dosimetry. DEFGEL, a 6%T normoxic polyacrylamide gel, was injected into 1-cm thick acrylic molds to create 1-cm thick small cylindrical patch dosimeters. To evaluate the change in optical density due to radiation induced polymerization, dosimeters were scanned before and after irradiation using an in-house developed laser densitometer. The dose-responses of three separate batches of gel were evaluated and compared to check for linearity and repeatability. The response development time was evaluated to ensure that the patch dosimeter could be high throughput. Additionally, the potential of this system to be used as an in vivo dosimeter was tested with a clinically relevant end-to-end in vivo phantom test. All irradiations were performed with a Varian Clinac 21EX at the University of Wisconsin Medical Radiation Research Center (UWMRRC). The dose response of all three batches of gel was found to be linear within the range of 2–20 Gy. At doses below 0.5 Gy the statistical uncertainties were prohibitively large to make quantitative assessments of the results. The three batches demonstrated good repeatability in the range of 2 Gy to up to 10 Gy, with only slight variations in response at higher doses. For low doses the dosimeter fully developed within an hour while at higher doses they fully developed within four hours. During the in vivo

Initial characterization of a gel patch dosimeter for in vivo dosimetry

NASA Astrophysics Data System (ADS)

Matrosic, C.; Culberson, W.; Rosen, B.; Madsen, E.; Frank, G.; Bednarz, B.

2016-05-01

In vivo dosimetry is a greatly underutilized tool for patient safety in clinical external beam radiotherapy treatments, despite being recommended by several national and international organizations (AAPM, ICRU, IAEA, NACP). The reasons for this underutilization mostly relate to the feasibility and cost of in vivo dosimetry methods. Due to the increase in the number of beam angles and dose per fraction in modern treatments, there is a compelling need for a novel dosimeter that is robust and affordable while able to operate properly in these complex conditions. This work presents a gel patch dosimeter as a novel method of in vivo dosimetry. DEFGEL, a 6% T normoxic polyacrylamide gel, was injected into 1 cm thick acrylic molds to create 1 cm thick small cylindrical patch dosimeters. To evaluate the change in optical density due to radiation induced polymerization, dosimeters were scanned before and after irradiation using an in-house developed laser densitometer. The dose-responses of three separate batches of gel were evaluated and compared to check for linearity and repeatability. The response development time was evaluated to ensure that the patch dosimeter could be high throughput. Additionally, the potential of this system to be used as an in vivo dosimeter was tested with a clinically relevant end-to-end in vivo phantom test. All irradiations were performed with a Varian Clinac 21EX at the University of Wisconsin Medical Radiation Research Center (UWMRRC). The dose-response of all three batches of gel was found to be linear within the range of 2-20 Gy. At doses below 0.5 Gy the statistical uncertainties were prohibitively large to make quantitative assessments of the results. The three batches demonstrated good repeatability in the range of 2 Gy to up to 10 Gy, with only slight variations in response at higher doses. For low doses the dosimeter fully developed within an hour while at higher doses they fully developed within four hours. During the in vivo

[Rapid laboratory detection of antigens of infective agents of infections and technical means for their realization].

PubMed

Kal'noĭ, S M

2003-01-01

A system of new accelerated and rapid methods for the detection of the antigens of the infective agents of plague, cholera, tularemia and brucellosis were developed on the basis of solid phase immunosuspension tests: the passive hemagglutination (PHA) test and the latex agglutination (LA) test. The immunological and physico-chemical properties of suspensions in the PHA and LA tests made it possible to use extraneous sources of energy (centrifugal acceleration and the electric field) to accelerate these tests. The results of the PHA and LA tests were registered with the use of a densitometer, model Ultrascan 2202, and a tester, model C 34014.2. To apply centrifugal acceleration and the electric field, a laboratory centrifuge and an electrophoretic microchamber were designed. Densitometry was carried out on modified plates and conductometry, with the use of modified electrodes. The time of obtaining the results of the PHA and LA tests was 15-30 minutes with the use of centrifugation and 2-5 minutes in the electric field, which made it possible to regard these tests as rapid.

National protocol for quality assurance in DXA-bone densitometry

NASA Astrophysics Data System (ADS)

Slavchev, A.; Avramova-Cholakova, S.; Vassileva, J.

2008-01-01

Osteoporosis becomes largely one of the most important socially significant and costly diseases. Modern techniques (DXA, US) are applied for bone densitometry. The paper presents a protocol for quality assurance especially of DXA-bone densitometers including quality control made in compliance with international standards (ISCD, IOF). The methodology has been tested in practice by measurements on site-functional assessment, entrance dose, radiation protection, calibration, in-vitro precision. It is expected to raise the quality of the diagnostic process in concert with the EU Medical Directive 97/43 particularly for population screening and sensitive groups. The protocol is an essential part of the National Program for constraining osteoporosis which has been elaborated at the Ministry of Health and at present under implementation throughout the country. It aims at reducing the risk, factors spreading, at diminishing the fracture risk the morbidity and the mortality from osteoporosis. An integral multidisciplinary approach to the problem solving is applied as well as training on three levels — doctors, patients, population, which effectively will contribute for obtaining real results in preventing osteoporosis.

Film dosimetry using a smart device camera: a feasibility study for point dose measurements

NASA Astrophysics Data System (ADS)

Aland, Trent; Jhala, Ekta; Kairn, Tanya; Trapp, Jamie

2017-10-01

In this work, a methodology for using a smartphone camera, in conjunction with a light-tight box operating in reflective transmission mode, is investigated as a proof of concept for use as a film dosimetry system. An imaging system was designed to allow the camera of a smartphone to be used as a pseudo densitometer. Ten pieces of Gafchromic EBT3 film were irradiated to doses up to 16.89 Gy and used to evaluate the effects of reproducibility and orientation, as well as the ability to create an accurate dose response curve for the smartphone based dosimetry system, using all three colour channels. Results were compared to a flatbed scanner system. Overall uncertainty was found to be best for the red channel with an uncertainty of 2.4% identified for film irradiated to 2.5 Gy and digitised using the smartphone system. This proof of concept exercise showed that although uncertainties still exceed a flatbed scanner system, the smartphone system may be useful for providing point dose measurements in situations where conventional flatbed scanners (or other dosimetry systems) are unavailable or unaffordable.

Radiopacity of different resin-based and conventional luting cements compared to human and bovine teeth.

PubMed

Pekkan, Gürel; Ozcan, Mutlu

2012-02-03

This study evaluated the radiopacity of different resin-based luting materials and compared the results to human and bovine dental hard tissues. Disc specimens (N=130, n=10 per group) (diameter: 6 mm, thickness: 1 mm) were prepared from 10 resin-based and 3 conventional luting cements. Human canine dentin (n=10), bovine enamel (n=10), bovine dentin (n=10) and Aluminium (Al) step wedge were used as references. The optical density values of each material were measured from radiographic images using a transmission densitometer. Al step wedge thickness and optical density values were plotted and equivalent Al thickness values were determined for radiopacity measurements of each material. The radiopacity values of conventional cements and two resin luting materials (Rely X Unicem and Variolink II), were significantly higher than that of bovine enamel that could be preferred for restorations cemented on enamel. Since all examined resin-based luting materials showed radiopacity values equivalent to or greater than that of human and bovine dentin, they could be considered suitable for the restorations cemented on dentin.

Film dosimetry using a smart device camera: a feasibility study for point dose measurements.

PubMed

Aland, Trent; Jhala, Ekta; Kairn, Tanya; Trapp, Jamie

2017-10-03

In this work, a methodology for using a smartphone camera, in conjunction with a light-tight box operating in reflective transmission mode, is investigated as a proof of concept for use as a film dosimetry system. An imaging system was designed to allow the camera of a smartphone to be used as a pseudo densitometer. Ten pieces of Gafchromic EBT3 film were irradiated to doses up to 16.89 Gy and used to evaluate the effects of reproducibility and orientation, as well as the ability to create an accurate dose response curve for the smartphone based dosimetry system, using all three colour channels. Results were compared to a flatbed scanner system. Overall uncertainty was found to be best for the red channel with an uncertainty of 2.4% identified for film irradiated to 2.5 Gy and digitised using the smartphone system. This proof of concept exercise showed that although uncertainties still exceed a flatbed scanner system, the smartphone system may be useful for providing point dose measurements in situations where conventional flatbed scanners (or other dosimetry systems) are unavailable or unaffordable.

Spectral calibration of EBT3 and HD-V2 radiochromic film response at high dose using 20 MeV proton beams

NASA Astrophysics Data System (ADS)

Feng, Yiwei; Tiedje, Henry F.; Gagnon, Katherine; Fedosejevs, Robert

2018-04-01

Radiochromic film is used extensively in many medical, industrial, and scientific applications. In particular, the film is used in analysis of proton generation and in high intensity laser-plasma experiments where very high dose levels can be obtained. The present study reports calibration of the dose response of Gafchromic EBT3 and HD-V2 radiochromic films up to high exposure densities. A 2D scanning confocal densitometer system is employed to carry out accurate optical density measurements up to optical density 5 on the exposed films at the peak spectral absorption wavelengths. Various wavelengths from 400 to 740 nm are also scanned to extend the practical dose range of such films by measuring the response at wavelengths removed from the peak response wavelengths. Calibration curves for the optical density versus exposure dose are determined and can be used for quantitative evaluation of measured doses based on the measured optical densities. It was found that blue and UV wavelengths allowed the largest dynamic range though at some trade-off with overall accuracy.

Enhancement of Dose Response and Nuclear Magnetic Resonance Image of PAGAT Polymer Gel Dosimeter by Adding Silver Nanoparticles

PubMed Central

Sabbaghizadeh, Rahim; Shamsudin, Roslinda; Deyhimihaghighi, Najmeh; Sedghi, Arman

2017-01-01

In the present study, the normoxic polyacrylamide gelatin and tetrakis hydroxy methyl phosphoniun chloride (PAGAT) polymer gel dosimeters were synthesized with and without the presence of silver (Ag) nanoparticles. The amount of Ag nanoparticles varied from 1 to 3 ml with concentration 3.14 g/l, thus forming two types of PAGAT polymer gel dosimeters before irradiating them with 6 to 25 Gy produced by 1.25-MeV 60Co gamma rays. In this range, the predominant gamma ray interaction with matter is by Compton scattering effect, as the photoelectric absorption effect diminishes. MRI was employed when evaluating the polymerization of the dosimeters and the gray scale of the MRI film was determined via an optical densitometer. Subsequent analyses of optical densities revealed that the extent of polymerization increased with the increase in the absorbed dose, while the increase of penetration depth within the dosimeters has a reverse effect. Moreover, a significant increase in the optical density-dose response (11.82%) was noted for dosimeters containing 2 ml Ag nanoparticles. PMID:28060829

Geographic applications of ERTS-A imagery to rural landscape change

NASA Technical Reports Server (NTRS)

Rehder, J. B. (Principal Investigator)

1972-01-01

There are no author-identified significant results in this report. The study area, centered on Knoxville, Tennessee, encompasses nearly 20,000 square miles. The Knoxville Test Site, an 11 x 21 mile area over the city of Knoxville and the western portion of Knox County, has been chosen for the analysis of landscape change detection associated with urban growth. The second area, the Cumberland Plateau Test Site, exhibits landscape change through forest alterations and landform disturbances associated with strip mining in the area and was so chosen for its sharp contrasts in physical and human phenomena as well as its change dynamics. Accomplishments since reception of ERTS-1 imagery include: (1) basic cataloging and classifying of the data into a filling system; (2) a densitometer analysis; (3) first look analysis; and (4) preparation of results from the project. Examples of all four bands of the MSS have been received and analyses reveal distinctive positive and negative reactions. Band 5 has been found to be best for landscape analysis of contrasts between urban and rural landscapes, and band 7 for topographic features and water surfaces. Preliminary results are summarized.

Evaluation of the strength and radiopacity of Portland cement with varying additions of bismuth oxide.

PubMed

Saliba, E; Abbassi-Ghadi, S; Vowles, R; Camilleri, J; Hooper, S; Camilleri, J

2009-04-01

To study the effect of addition of various proportions of bismuth oxide on compressive strength and radiopacity of Portland cement. The compressive strength of white Portland cement and cement replaced with 10, 15, 20, 25 and 30% bismuth oxide was evaluated by testing cylinders 6 mm in diameter and 12 mm high. Twelve cylinders were tested for each material under study. The radiopacity of the cements tested was evaluated using an aluminium step-wedge and densitometer. The optical density was compared with the relevant thickness of aluminium (Al). Statistical analysis was performed using Analysis of Variance (ANOVA) with P = 0.05 and Tukey test to perform multiple comparison tests. Various additions of bismuth oxide had no significant effect on the strength of the material when compared with the unmodified Portland cement (P > 0.05). The radiopacity of the cements tested ranged from 2.02 mm Al for Portland cement to 9.79 mm Al for the highest bismuth replacement. Addition of bismuth oxide did not affect the compressive strength of Portland cement. All the bismuth oxide cement mixtures had radio-opacities higher than 3 mm thickness of aluminium.

The role of single immediate loading implant in long Class IV Kennedy mandibular partial denture.

PubMed

Mohamed, Gehan F; El Sawy, Amal A

2012-10-01

The treatment of long-span Kennedy class IV considers a prosthodontic challenge. This study evaluated the integrity of principle abutments in long Kennedy class IV clinically and radiographically, when rehabilitated with conventional metallic partial denture as a control group and mandibular partial overdentures supported with single immediately loaded implant in symphyseal as a study group. Twelve male patients were divided randomly allotted into two equal groups. First group patients received removable metallic partial denture, whereas in the second group, patients received partial overdentures supported with single immediately loaded implant in symphyseal region. The partial dentures design in both groups was the same. Long-cone paralleling technique and transmission densitometer were used at the time of denture insertion, 3, 6, and 12 months. Gingival index, bone loss, and optical density were measured for principle abutments during the follow-up. A significant reduction in bone loss and density were detected in group II comparing with group I. Gingival index had no significant change (p-value < 0.05). A single symphyseal implant in long span class IV Kennedy can play a pivotal role to improve the integrity of the principle abutments and alveolar bone support. © 2010 Wiley Periodicals, Inc.

[High prevalence of osteoporosis in asymptomatic postmenopausal Mapuche women].

PubMed

Ponce, Lucía; Larenas, Gladys; Riedemann, Pablo

2002-12-01

Genetic and environmental factors are responsible for variations in the frequency of osteoporosis. Prevalence of osteoporosis in Mapuche women (native Chileans) is unknown. To assess the prevalence and risk factors for osteoporosis in Mapuche women. A random sample of 95 asymptomatic postmenopausal Mapuche females, stratified by age, was studied. Women with diseases or medications that could interfere with calcium metabolism were excluded. Spine and femoral neck bone mass density was determined using a Lunar DPX Alpha densitometer. Seventeen percent of women had normal bone mineral density in both spine and femoral neck. In the spine, 25.3% had a normal bone mineral density, 17.9% had osteopenia and 56.8% had osteoporosis. In the femoral neck, 34.7% had a normal bone mineral density, 57.9% had osteopenia, and 7.4% had osteoporosis. There was a positive correlation between bone mineral density and body mass index. Women with more than one hour per day of physical activity, had a significantly lower proportion of osteopenia or osteoporosis. No association between bone mineral density and parity or calcium intake, was observed. There is a high prevalence of osteopenia and osteoporosis among Mapuche women. Osteoporosis was associated with low body mass index.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phillion, D.

This code enables one to display, take line-outs on, and perform various transformations on an image created by an array of integer*2 data. Uncompressed eight-bit TIFF files created on either the Macintosh or the IBM PC may also be read in and converted to a 16 bit signed integer image. This code is designed to handle all the formats used for PDS (photo-densitometer) files at the Lawrence Livermore National Laboratory. These formats are all explained by the application code. The image may be zoomed infinitely and the gray scale mapping can be easily changed. Line-outs may be horizontal or verticalmore » with arbitrary width, angled with arbitrary end points, or taken along any path. This code is usually used to examine spectrograph data. Spectral lines may be identified and a polynomial fit from position to wavelength may be found. The image array can be remapped so that the pixels all have the same change of lambda width. It is not necessary to do this, however. Lineouts may be printed, saved as Cricket tab-delimited files, or saved as PICT2 files. The plots may be linear, semilog, or logarithmic with nice values and proper scientific notation. Typically, spectral lines are curved.« less

Arterial input function of an optical tracer for dynamic contrast enhanced imaging can be determined from pulse oximetry oxygen saturation measurements

NASA Astrophysics Data System (ADS)

Elliott, Jonathan T.; Wright, Eric A.; Tichauer, Kenneth M.; Diop, Mamadou; Morrison, Laura B.; Pogue, Brian W.; Lee, Ting-Yim; St. Lawrence, Keith

2012-12-01

In many cases, kinetic modeling requires that the arterial input function (AIF)—the time-dependent arterial concentration of a tracer—be characterized. A straightforward method to measure the AIF of red and near-infrared optical dyes (e.g., indocyanine green) using a pulse oximeter is presented. The method is motivated by the ubiquity of pulse oximeters used in both preclinical and clinical applications, as well as the gap in currently available technologies to measure AIFs in small animals. The method is based on quantifying the interference that is observed in the derived arterial oxygen saturation (SaO2) following a bolus injection of a light-absorbing dye. In other words, the change in SaO2 can be converted into dye concentration knowing the chromophore-specific extinction coefficients, the true arterial oxygen saturation, and total hemoglobin concentration. A simple error analysis was performed to highlight potential limitations of the approach, and a validation of the method was conducted in rabbits by comparing the pulse oximetry method with the AIF acquired using a pulse dye densitometer. Considering that determining the AIF is required for performing quantitative tracer kinetics, this method provides a flexible tool for measuring the arterial dye concentration that could be used in a variety of applications.

Arterial input function of an optical tracer for dynamic contrast enhanced imaging can be determined from pulse oximetry oxygen saturation measurements.

PubMed

Elliott, Jonathan T; Wright, Eric A; Tichauer, Kenneth M; Diop, Mamadou; Morrison, Laura B; Pogue, Brian W; Lee, Ting-Yim; St Lawrence, Keith

2012-12-21

In many cases, kinetic modeling requires that the arterial input function (AIF)--the time-dependent arterial concentration of a tracer--be characterized. A straightforward method to measure the AIF of red and near-infrared optical dyes (e.g., indocyanine green) using a pulse oximeter is presented. The method is motivated by the ubiquity of pulse oximeters used in both preclinical and clinical applications, as well as the gap in currently available technologies to measure AIFs in small animals. The method is based on quantifying the interference that is observed in the derived arterial oxygen saturation (SaO₂) following a bolus injection of a light-absorbing dye. In other words, the change in SaO₂ can be converted into dye concentration knowing the chromophore-specific extinction coefficients, the true arterial oxygen saturation, and total hemoglobin concentration. A simple error analysis was performed to highlight potential limitations of the approach, and a validation of the method was conducted in rabbits by comparing the pulse oximetry method with the AIF acquired using a pulse dye densitometer. Considering that determining the AIF is required for performing quantitative tracer kinetics, this method provides a flexible tool for measuring the arterial dye concentration that could be used in a variety of applications.

Sensitivity and comparison evaluation of Saturn 5 liquid penetrants

NASA Technical Reports Server (NTRS)

Jones, G. H.

1973-01-01

Results of a sensitivity and comparison evaluation performed on six liquid penetrants that were used on the Saturn 5 vehicle and other space hardware to detect surface discontinuities are described. The relationship between penetrant materials and crack definition capabilities, the optimum penetrant materials evaluation method, and the optimum measurement methods for crack dimensions were investigated. A unique method of precise developer thickness control was envolved, utilizing clear radiographic film and a densitometer. The method of evaluation included five aluminum alloy, 2219-T87, specimens that were heated and then quenched in cold water to produce cracks. The six penetrants were then applied, one at a time, and the crack indications were counted and recorded for each penetrant for comparison purposes. Measurements were made by determining the visual crack indications per linear inch and then sectioning the specimens for a metallographic count of the cracks present. This method provided a numerical approach for assigning a sensitivity index number to the penetrants. Of the six penetrants evaluated, two were not satisfactory (one was not sufficiently sensitive and the other was to sensitive, giving false indications). The other four were satisfactory with approximately the same sensitivity in the range of 78 to 80.5 percent of total cracks detected.

Screening for osteoporosis among post-menopausal women in community pharmacy

PubMed Central

Barris Blundell, Damià; Rodríguez Zarzuelo, Carmen; Sabio Sánchez, Belén; Gutiérrez álvarez, José Luis; Navarro Visa, Elena; Muñoz Valdés, Oscar; Garrido Jiménez, Belén; Gómez, Rocío Sánchez

Objectives To identify postmenopausal women with risk of osteoporosis through quantitative ultrasound imaging (QUI) and to value the medical intervention after the determination of the bone mineral density (BMD). Methods Cross-sectional descriptive study developed in a community pharmacy. During the month of June of 2005 the community pharmacy enrolled postmenopausal women into the study. Women in treatment with calcium, vitamin D, hormone replacement therapy, estrogen receptor modulators, calcitonin or biphosphonates were considered criteria for exclusion. To all the women that consent to participate, the pharmacist measured BMD with the device Sahara Hologic Ultrasound Bone Densitometer at right calcaneus. Following the World Health Organization, women were classified as osteoporotic if their T-Score was less than -2.5 and as osteopenic if their T-Score ranged between -2.5 and -1.0. Results Of the 100 women screened, 11 (11%) presented risk of osteoporosis and 61 (61%) of osteopenia. The 18.5% postmenopausal women with body mass index lesser than 30 presented risk of osteoporosis and the 63.0% osteopenia. Conclusions The QUI constitutes a useful tool in community pharmacy for the screening of osteoporosis and it supposes a greater integration of the community pharmacy within the health care. PMID:25247006

Novel Proximal Sensing for Monitoring Soil Organic C Stocks and Condition.

PubMed

Viscarra Rossel, Raphael A; Lobsey, Craig R; Sharman, Chris; Flick, Paul; McLachlan, Gordon

2017-05-16

Soil information is needed for environmental monitoring to address current concerns over food, water and energy securities, land degradation, and climate change. We developed the Soil Condition ANalysis System (SCANS) to help address these needs. It integrates an automated soil core sensing system (CSS) with statistical analytics and modeling to characterize soil at fine depth resolutions and across landscapes. The CSS's sensors include a γ-ray attenuation densitometer to measure bulk density, digital cameras to image the measured soil, and a visible-near-infrared (vis-NIR) spectrometer to measure iron oxides and clay mineralogy. The spectra are also modeled to estimate total soil organic carbon (C), particulate, humus, and resistant organic C (POC, HOC, and ROC, respectively), clay content, cation exchange capacity (CEC), pH, volumetric water content, available water capacity (AWC), and their uncertainties. Measurements of bulk density and organic C are combined to estimate C stocks. Kalman smoothing is used to derive complete soil property profiles with propagated uncertainties. The SCANS provides rapid, precise, quantitative, and spatially explicit information about the properties of soil profiles with a level of detail that is difficult to obtain with other approaches. The information gained effectively deepens our understanding of soil and calls attention to the central role soil plays in our environment.

Fabric dependence of wave propagation in anisotropic porous media

PubMed Central

Cowin, Stephen C.; Cardoso, Luis

2012-01-01

Current diagnosis of bone loss and osteoporosis is based on the measurement of the Bone Mineral Density (BMD) or the apparent mass density. Unfortunately, in most clinical ultrasound densitometers: 1) measurements are often performed in a single anatomical direction, 2) only the first wave arriving to the ultrasound probe is characterized, and 3) the analysis of bone status is based on empirical relationships between measurable quantities such as Speed of Sound (SOS) and Broadband Ultrasound Attenuation (BUA) and the density of the porous medium. However, the existence of a second wave in cancellous bone has been reported, which is an unequivocal signature of poroelastic media, as predicted by Biot’s poroelastic wave propagation theory. In this paper the governing equations for wave motion in the linear theory of anisotropic poroelastic materials are developed and extended to include the dependence of the constitutive relations upon fabric - a quantitative stereological measure of the degree of structural anisotropy in the pore architecture of a porous medium. This fabric-dependent anisotropic poroelastic approach is a theoretical framework to describe the microarchitectural-dependent relationship between measurable wave properties and the elastic constants of trabecular bone, and thus represents an alternative for bone quality assessment beyond BMD alone. PMID:20461539

Evaluate ERTS imagery for mapping and detection of changes of snowcover on land and on glaciers. [Cascade Mountains

NASA Technical Reports Server (NTRS)

Meier, M. F. (Principal Investigator)

1974-01-01

The author has identified the following significant results. Snowlines on a small drainage basin were accurately identified on bulk ERTS-1 images without use of digital processing, and results checked with high altitude and ground-based photography. The area and approximate shape of snow patches as small as 20,000 sq m could be correctly identified with a magnifying scanning densitometer. The resolution of ERTS is more than ample for most snow mapping needs. Mount Baker, Washington, has a large crater south of the summit and an area north of the summit which emit considerable geothermal heat in the form of fumaroles and hot ground. Temperatures are being monitored using an ERTS DCS. Debris flows are occassionally released from the crater due to water saturation at the base of a heavy snowpack lying on hydrothermally altered hot ground. These debris flows present a possible hazard to life and property, as they are discharged down the Boulder Glacier toward Baker Lake, the upper of two major hydroelectric power reservoirs which are situated above the populated Skagit River Valley. ERTS-1 images show that the most recent debris flow (20-21 August 1973) can be clearly discerned and mapped. ERTS images provide another important tool for monitoring this potential hazard.

Calcaneal quantitative ultrasound value for middle-aged and elderly Malaysian Chinese men and its association with age and body anthropometry.

PubMed

Chin, Kok-Yong; Ima-Nirwana, Soelaiman; Isa Naina, Mohamed; Norazlina, Mohamed; Ahmad Nazrun, Shuid; Norliza, Muhammad; Faizah, Othman; Farihah, H Suhaimi; Elvy Suhana, Mohd Ramli; Wan Zurinah, Wan Ngah

2012-01-01

Quantitative ultrasound (QUS) is a relatively easy, reliable, and safe method for bone status assessment, but reference data for Asian males remain scarce. Our study aimed to determine the values for one QUS parameter, the speed of sound (SOS) at the calcaneus, in Malaysian Chinese men and to determine the association between the SOS and several demographic characteristics, such as age, weight, height, and body mass index. Three hundred forty-eight Malaysian Chinese men aged 40 yr and older were recruited, and their calcaneal QUS value was determined using the CM-200 densitometer (Furuno Electric, Nishinomiya City, Japan). The results indicated a significant correlation between SOS and age, and multiple stepwise regression analysis indicated that age and height were important predictors of SOS. A significant reduction in SOS value was observed when men 60 yr and older were compared with men aged 40-49 yr. Compared with the reference data for Japanese males, Chinese men in Malaysia showed higher SOS values across all the age groups studied. In conclusion, there is an age-related decrease in SOS values in Malaysian Chinese men, and the SOS values established in this study can be used as a reference for future studies. Copyright © 2012 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

A new device for acquiring ground truth on the absorption of light by turbid waters

NASA Technical Reports Server (NTRS)

Klemas, V. (Principal Investigator); Srna, R.; Treasure, W.

1974-01-01

The author has identified the following significant results. A new device, called a Spectral Attenuation Board, has been designed and tested, which enables ERTS-1 sea truth collection teams to monitor the attenuation depths of three colors continuously, as the board is being towed behind a boat. The device consists of a 1.2 x 1.2 meter flat board held below the surface of the water at a fixed angle to the surface of the water. A camera mounted above the water takes photographs of the board. The resulting film image is analyzed by a micro-densitometer trace along the descending portion of the board. This yields information on the rate of attenuation of light penetrating the water column and the Secchi depth. Red and green stripes were painted on the white board to approximate band 4 and band 5 of the ERTS MSS so that information on the rate of light absorption by the water column of light in these regions of the visible spectrum could be concurrently measured. It was found that information from a red, green, and white stripe may serve to fingerprint the composition of the water mass. A number of these devices, when automated, could also be distributed over a large region to provide a cheap method of obtaining valuable satellite ground truth data at present time intervals.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phillion, D.

This code enables one to display, take line-outs on, and perform various transformations on an image created by an array of integer*2 data. Uncompressed eight-bit TIFF files created on either the Macintosh or the IBM PC may also be read in and converted to a 16 bit signed integer image. This code is designed to handle all the formates used for PDS (photo-densitometer) files at the Lawrence Livermore National Laboratory. These formats are all explained by the application code. The image may be zoomed infinitely and the gray scale mapping can be easily changed. Line-outs may be horizontal or verticalmore » with arbitrary width, angled with arbitrary end points, or taken along any path. This code is usually used to examine spectrograph data. Spectral lines may be identified and a polynomial fit from position to wavelength may be found. The image array can be remapped so that the pixels all have the same change of lambda width. It is not necessary to do this, however. Lineouts may be printed, saved as Cricket tab-delimited files, or saved as PICT2 files. The plots may be linear, semilog, or logarithmic with nice values and proper scientific notation. Typically, spectral lines are curved. By identifying points on these lines and fitting their shapes by polyn.« less

Elevation of D4 dopamine receptor mRNA in postmortem schizophrenic brain.

PubMed

Stefanis, N C; Bresnick, J N; Kerwin, R W; Schofield, W N; McAllister, G

1998-01-01

The D4 dopamine (DA) receptor has been proposed to be a target for the development of a novel antipsychotic drug based on its pharmacological and distribution profile. There is much interest in whether D4 DA receptor levels are altered in schizophrenia, but the lack of an available receptor subtype-specific radioligand made this difficult to quantitate. In this study, we examined whether D4 mRNA levels are altered in different brain regions of schizophrenics compared to controls. Ribonuclease protection assays were carried out on total RNA samples isolated postmortem from frontal cortex and caudate brain regions of schizophrenics and matched controls. 32P-labelled RNA probes to the D4 DA receptor and to the housekeeping gene, glyceraldehyde-3-phosphate dehydrogenase (G3PDH), were hybridised with the RNA samples, digested with ribonucleases to remove unhybridised probe, and separated on 6% sequencing gels. Densitometer analysis on the subsequent autoradiogams was used to calculate the relative optical density of D4 mRNA compared to G3PDH mRNA. Statistical analysis of the data revealed a 3-fold higher level (P<0.011) of D4 mRNA in the frontal cortex of schizophrenics compared to controls. No increase was seen in caudate. D4 receptors could play a role in mediating dopaminergic activity in frontal cortex, an activity which may be malfunctioning in schizophrenia.

[MINERAL BONE DENSITY AND BODY COMPOSITION IN PARTICIPANTS IN EXPERIMENT MARS-500].

PubMed

Novikov, V E; Oganov, V S; Kabitskaya, O E; Murashko, L M; Naidina, V P; Chernikhova, E A

2016-01-01

Investigations of the bone system and body composition in Mars-500 test-subjects (prior to and on completion of the experiment) involved dual-energy X-ray absorptiometry (DXA) using the HOLOGIC Delphy densitometer and the protocol performed to examine cosmonauts. Bone density of lumber vertebrae and femoral proximal epiphysis, and body composition were measured. Reliable changes in vertebral density found in 3 test-subjects displayed different trends from +2.6 to -2.4%. At the same time, the experiment decreased significantly mineral density of the femoral proximal epiphysis, including the neck, in all test-subjects. Four test-subjects had cranial mineralization increased by 5-9%, same as in some cosmonauts after space flight. All tests-subjects incurred adipose loss from 2 to 7 kg; one test-subject lost 20 kg, i.e. his adipose mass became three times less. Changes in lean mass (1-3 kg) typically were negative; as for changes in lean mass of extremities, they could be linked with adherence to one or another type of physical activity. Therefore, extended exposure to confinement may affect mineralization of some parts of the skeleton. Unlike real space missions and long-term bedrest studies conducted at the Institute of Biomedical Problems in the past, Mars-500 did not cause clinically significant mineral losses (osteoporosis, osteopenia), probably because of the absence of effects of microgravity.

Radiopacity of conventional, resin-modified glass ionomer, and resin-based luting materials.

PubMed

Tsuge, Takuma

2009-06-01

The purpose of the present study was to evaluate the radiopacity of currently available dental luting materials. Five conventional cements, six resin-modified glass ionomers (RMGIs), two methyl methacrylate (MMA)-based acrylic resins (eight shades), and nine composite luting materials were evaluated. Radiographs of the specimens were taken together with tooth slices and aluminum step wedges. The density of the specimens was determined with a densitometer and was expressed in terms of the equivalent thickness of aluminum per 2.0-mm unit thickness of specimen. The radiopacity values for human enamel and dentin were 4.3 and 2.3 mm Al/2.0 mm specimen, respectively. The values for materials ranged from 5.1 to 12.9 for conventional luting materials, from 3.4 to 6.3 for RMGIs, from less than 0.5 to 7.3 for MMA resins, and from 2.3 to 9.9 for the composite luting materials. A zinc phosphate cement showed the highest value (12.9), whereas five shades of MMA resin resulted in the lowest value (less than 0.5). Two RMGIs and three composite luting materials exhibited radiopacity values between those of enamel (4.3) and dentin (2.3). It can be concluded that the radiopacity value of luting materials varies considerably, and that care must be taken when selecting luting materials, considering the material composition of restorations.

Measurements and calculations of water velocity, momentum flux, and related flow parameters obtaned from single-phase water integral acceptance tests of the PKL instrumented spool pieces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stein, W.

The operation of the emergency core cooling system and its related steam-binding problems in pressurized water reactors is the subject of a cooperative study by the United States, Germany, and Japan. Lawrence Livermore Laboratory and EG and G, Inc., San Ramon Operations, are responsible for the design, hardware, and software of the 80.8-mm and 113-mm spool piece measurement systems for the German Primarkreislauf (PKL) Test Facility at Kraftwerk Union in Erlangen, West Germany. This work was done for the US Nuclear Regulatory Commission, Division of Reactor Safety Research, under its 3-D Technical Support and Instrumentation Program. Four instrumented spools capablemore » of measuring individual phase parameters in two-phase flows were constructed. Each spool contains a flow turbine, drag screen, three-beam densitometer, and pressure and temperature probes. A computerized data acquisition system is also provided to store and analyze data from the four spools. The four spools were shipped to the PKL Test Facility in West Germany for acceptance testing in a water-flow loop. Spool measurements of velocity and momentum flux were compared to the values obtained from an orifice meter installed in the loop piping system. The turbine flowmeter velocity data for all tests were within allowable tolerances. Drag screen momentum flux measurements were also within tolerance with the exception of a few points.« less

Fan-beam densitometry of the growing skeleton: are we measuring what we think we are?

PubMed

Cole, Jacqueline H; Scerpella, Tamara A; van der Meulen, Marjolein C H

2005-01-01

Magnification error in fan-beam densitometers varies with distance from the X-ray source to the bone measured and might obscure bone mineral changes in the growing skeleton. Magnification was examined by scanning aluminum rods of different shapes (square, rectangular, solid round, and hollow round) at four distances above the X-ray source in two orientations, with rods aligned parallel (SI) and perpendicular (ML) to the longitudinal axis of the scanning table. Measured area (cm(2)) decreased linearly with distance above the X-ray source for all rods in the SI orientation (p < 0.005). Measured mineral content (g) decreased linearly with distance but only for SI round rods (p < 0.0001) and for ML hollow round rods (p < 0.005). Area and mineral content decreased 1.6-1.8% per centimeter above the source for round rods. Measured mineral density (g/cm(2)) decreased linearly with distance from the source only for ML hollow round rods (p < 0.005). Variation in area, mineral content, and mineral density measurements was 6.6-6.9%, 6.9-7.5%, and 1.9-2.3%, respectively, for SI round rods. Magnification errors of this magnitude are problematic for clinical studies using fan-beam densitometry. Particularly in pediatric subjects, increases in soft tissue during normal growth could increase a bone's distance from the fan-beam source and result in apparent reductions in area and bone mineral content.

Nonintrusive Measurements for High-Speed, Supersonic, and Hypersonic Flows

NASA Astrophysics Data System (ADS)

Bonnet, J. P.; Grésillon, D.; Taran, J. P.

The need to develop new diagnostics for turbulent flows at supersonic and hypersonic regimes is discussed. New experimental results can be obtained in supersonic flows by using the collective light scattering method. Typical results obtained by this method in a supersonic mixing layer are illustrated. The collective light scattering method is a directional densitometer (with a new type of spectral analysis of density fluctuations), a nonparticle anemometer, a Mach-meter (or thermometer), and a directional remote microphone. Various other optical techniques that can be applied for point, line-of-sight, or imaging measurements are reviewed. For point measurements, light-scattering methods such as Raman, Rayleigh, or electron beam fluorescence are discussed, but only briefly, since they are of little use, especially when enthalpy is very high and flow naturally bright. Emphasis is placed instead on nonlinear laser spectroscopy such as coherent anti-Stokes Raman scattering, which has recently been successful in determining temperature and density in high-enthalpy shocks. A description of diode laser absorption spectroscopy follows. A high data-rate instrument now routinely gives the static temperature and the velocity of the stream in the hot shot facility F4 of ONERA, at stagnation enthalpies in excess of 15 MJ/kg. Finally, electron beam fluorescence imaging in the same facility has made it possible to perform measurements of velocity across the external boundary layer into the flow core using a high-energy-pulsed electron gun.

Characterization of drug authenticity using thin-layer chromatography imaging with a mobile phone.

PubMed

Yu, Hojeong; Le, Huy M; Kaale, Eliangiringa; Long, Kenneth D; Layloff, Thomas; Lumetta, Steven S; Cunningham, Brian T

2016-06-05

Thin-layer chromatography (TLC) has a myriad of separation applications in chemistry, biology, and pharmacology due to its simplicity and low cost. While benchtop laboratory sample application and detection systems for TLC provide accurate quantitation of TLC spot positions and densities, there are many applications where inexpensive and portable instruments would greatly expand the applicability of the technology. In this work, we demonstrate identity verification and concentration determination of pharmaceutical compounds via TLC using a custom 3D-printed cradle that interfaces with an ordinary mobile phone. The cradle holds the mobile phone's internal, rear-facing camera in a fixed position relative to a UV lamp and a TLC plate that includes a phosphor in the stationary phase. Analysis of photographs thus reveals the locations and intensities of principal spots of UV--absorbing drugs. Automated image analysis software determines the center location and density of dark spots, which, using integrated calibration spots of known drug compounds and concentrations, can be used to determine if a drug has been diluted or substituted. Two independent image processing approaches have been developed that may be selected based upon the processing capabilities of the smartphone. Each approach is able to discern 5% drug concentration differences. Using single-component solutions of nevirapine, amodiaquine, and paracetamol that have been manually applied, the mobile phone-based detection instrument provides measurements that are equivalent to those obtained with a commercially available lab-based desktop TLC densitometer. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparison between wire mesh sensor and gamma densitometry void measurements in two-phase flows

NASA Astrophysics Data System (ADS)

Sharaf, S.; Da Silva, M.; Hampel, U.; Zippe, C.; Beyer, M.; Azzopardi, B.

2011-10-01

Wire mesh sensors (WMS) are fast imaging instruments that are used for gas-liquid and liquid-liquid two-phase flow measurements and experimental investigations. Experimental tests were conducted at Helmholtz-Zentrum Dresden-Rossendorf to test both the capacitance and conductance WMS against a gamma densitometer (GD). A small gas-liquid test facility was utilized. This consisted of a vertical round pipe approximately 1 m in length, and 50 mm internal diameter. A 16 × 16 WMS was used with high spatial and temporal resolutions. Air-deionized water was the two-phase mixture. The gas superficial velocity was varied between 0.05 m s-1 and 1.4 m s-1 at two liquid velocities of 0.2 and 0.7 m s-1. The GD consisted of a collimated source and a collimated detector. The GD was placed on a moving platform close to the plane of wires of the sensor, in order to align it accurately using a counter mechanism, with each of the wires of the WMS, and the platform could scan the full section of the pipe. The WMS was operated as a conductivity WMS for a half-plane with eight wires and as a capacitance WMS for the other half. For the cross-sectional void (time and space averaged), along each wire, there was good agreement between WMS and the GD chordal void fraction near the centre of the pipe.

Osteoporosis screening is unjustifiably low in older African-American women.

PubMed Central

Wilkins, Consuelo H.; Goldfeder, Jason S.

2004-01-01

BACKGROUND: More than one million Americans suffer osteoporotic fractures yearly, resulting in a marked increase in morbidity and mortality. Despite a decrease in bone mineral density with increasing age in all ethnic groups and both genders, preventative and therapeutics efforts in osteoporosis have been focused on caucasian and Asian women. This study assesses the osteoporosis screening practices and the frequency of low bone density in a primarily African-American population of older women. METHODS: Medical records of 252 women at risk for osteoporosis were reviewed for the diagnosis of osteoporosis, prior osteoporosis screening, prior breast cancer screening, and the use of calcium, vitamin D or estrogen. Subsequently, 128 women were assessed for risk factors for osteoporosis, and their bone mineral density was measured using a peripheral bone densitometer. RESULTS: Osteoporosis screening had been performed in 11.5% of the subjects. Of the women evaluated by peripheral bone densitometry, 44.5% of all women, 40.4% of African-American women, and 53.3% of caucasian women had abnormally low bone density measurements. The frequency of abnormal bone density increased with both increasing age and decreasing body mass index. CONCLUSIONS: Although few women in this population were previously screened for osteoporosis, low bone density occurred in African-American women at substantial rates. Increasing age and low body mass are important risk factors for low bone density in African-American women. Ethnicity should not be used as an exclusion criterion for screening for osteoporosis. PMID:15101666

Precocious Ossification of the Tympanoperiotic Bone in Fetal and Newborn Dolphins: An Evolutionary Adaptation to the Aquatic Environment?

PubMed

Cozzi, Bruno; Podestà, Michela; Vaccaro, Calogero; Poggi, Roberto; Mazzariol, Sandro; Huggenberger, Stefan; Zotti, Alessandro

2015-07-01

The present study, performed with a dual-energy X-ray (DXA) bone densitometer on a series of fetal and newborn striped and short-beaked common dolphins, shows that the bone density of the area of the tympanic bulla within the tympanoperiotic complex starts with 0.483 g cm(-2) in 5- to 6-month-old specimens of striped (or common) dolphin fetuses and reaches 1.841 g cm(-2) in newborn striped dolphins, with values consistently higher than in other parts of the skull or elsewhere in the skeleton. The same results apply to the common bottlenose dolphins, in which the area of the tympanic bulla has a density of 0.312 g cm(-2) in 5-month-old specimens and becomes four times as much in newborns. Regardless of the areal bone density results correlated to the DXA-technique, comparisons with DXA-bone density data in the literature referred to other mammals emphasize the presence of very high mineral deposition in the area of the tympanoperiotic bone in fetal and newborn dolphins and the most dense part of it belongs to the tympanic bulla. The early osseous maturation of the tympanic bulla area may be compared to what described in fin whales and may represent an unique ontogenetic and phylogenetic feature of cetaceans, possibly related to the development of essential acoustic sense and establishment of immediate post-natal mother-calf relationship. © 2015 Wiley Periodicals, Inc.

Recognizing Banknote Fitness with a Visible Light One Dimensional Line Image Sensor

PubMed Central

Pham, Tuyen Danh; Park, Young Ho; Kwon, Seung Yong; Nguyen, Dat Tien; Vokhidov, Husan; Park, Kang Ryoung; Jeong, Dae Sik; Yoon, Sungsoo

2015-01-01

In general, dirty banknotes that have creases or soiled surfaces should be replaced by new banknotes, whereas clean banknotes should be recirculated. Therefore, the accurate classification of banknote fitness when sorting paper currency is an important and challenging task. Most previous research has focused on sensors that used visible, infrared, and ultraviolet light. Furthermore, there was little previous research on the fitness classification for Indian paper currency. Therefore, we propose a new method for classifying the fitness of Indian banknotes, with a one-dimensional line image sensor that uses only visible light. The fitness of banknotes is usually determined by various factors such as soiling, creases, and tears, etc. although we just consider banknote soiling in our research. This research is novel in the following four ways: first, there has been little research conducted on fitness classification for the Indian Rupee using visible-light images. Second, the classification is conducted based on the features extracted from the regions of interest (ROIs), which contain little texture. Third, 1-level discrete wavelet transformation (DWT) is used to extract the features for discriminating between fit and unfit banknotes. Fourth, the optimal DWT features that represent the fitness and unfitness of banknotes are selected based on linear regression analysis with ground-truth data measured by densitometer. In addition, the selected features are used as the inputs to a support vector machine (SVM) for the final classification of banknote fitness. Experimental results showed that our method outperforms other methods. PMID:26343654

In vivo precision of the GE Lunar iDXA densitometer for the measurement of total-body, lumbar spine, and femoral bone mineral density in adults.

PubMed

Hind, Karen; Oldroyd, Brian; Truscott, John G

2010-01-01

Knowledge of precision is integral to the monitoring of bone mineral density (BMD) changes using dual-energy X-ray absorptiometry (DXA). We evaluated the precision for bone measurements acquired using a GE Lunar iDXA (GE Healthcare, Waukesha, WI) in self-selected men and women, with mean age of 34.8 yr (standard deviation [SD]: 8.4; range: 20.1-50.5), heterogeneous in terms of body mass index (mean: 25.8 kg/m(2); SD: 5.1; range: 16.7-42.7 kg/m(2)). Two consecutive iDXA scans (with repositioning) of the total body, lumbar spine, and femur were conducted within 1h, for each subject. The coefficient of variation (CV), the root-mean-square (RMS) averages of SDs of repeated measurements, and the corresponding 95% least significant change were calculated. Linear regression analyses were also undertaken. We found a high level of precision for BMD measurements, particularly for scans of the total body, lumbar spine, and total hip (RMS: 0.007, 0.004, and 0.007 g/cm(2); CV: 0.63%, 0.41%, and 0.53%, respectively). Precision error for the femoral neck was higher but still represented good reproducibility (RMS: 0.014 g/cm(2); CV: 1.36%). There were associations between body size and total-body BMD and total-hip BMD SD precisions (r=0.534-0.806, p<0.05) in male subjects. Regression parameters showed good association between consecutive measurements for all body sites (r(2)=0.98-0.99). The Lunar iDXA provided excellent precision for BMD measurements of the total body, lumbar spine, femoral neck, and total hip. Copyright © 2010 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Pediatric data for dual X-ray absorptiometric measures of normal lumbar bone mineral density in children under 5 years of age using the lunar prodigy densitometer.

PubMed

Manousaki, D; Rauch, F; Chabot, G; Dubois, J; Fiscaletti, M; Alos, N

2016-09-07

Knowledge of physiological variations of bone mineral density (BMD) in newborns and infants is necessary to evaluate pathological changes associated with fractures. Limited reference data for children under 5 years old are available. This study provides normative data of lumbar BMD for the Lunar Prodigy in young children under 5 years old. We assessed cross-sectionally 155 healthy children (77 boys, 80% Caucasian), ranging in age from newborn to the age of 5 years. Lumbar bone mineral content (BMC) and areal BMD were measured by dual-energy X-ray absorptiometry using a Lunar Prodigy absorptiometer. Volumetric BMD was calculated using the Kroeger and Carter methods. BMC and areal BMD increased from birth to 5 years (p<0.001). Volumetric BMD did not change with age. BMD and BMC correlated with age, weight and height (R(2)≥0.85 for all), with a maximum gain between the ages of 1 and 4 years, which did not follow the same pattern as height velocity. We did not find significant sex difference for any of the three measured parameters. This study provides normative data for lumbar spine densitometry of infants and young children using the Lunar Prodigy DXA system.

Mixed donor chimerism in non-malignant haematological diseases after allogeneic bone marrow transplantation.

PubMed

Shamshad, Ghassan Umair; Ahmed, Suhaib; Bhatti, Farhat Abbas; Ali, Nadir

2012-12-01

To determine the frequency of mixed donor chimerism in patients of non-malignant haematological diseases after allogeneic bone marrow transplant. A cross-sectional, observational study. Department of Haematology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, from July 2010 to June 2011. Donor chimerism was assessed in patients of aplastic anaemia and beta-thalassaemia major who underwent allogeneic bone marrow transplantation (BMT). Peripheral blood samples were used to assess chimerism status by analysis of short tandem repeats (STR). In patients where pre-transplant blood sample was not available, swab of buccal mucosa was used for pre-transplant STR profile. A standard set of primers for STR markers were used and the amplified DNA was resolved by gel electrophoresis and stained with silver nitrate. The percentage of donor origin DNA was estimated by densitometer. Out of 84 patients, 52 (62%) were males, while 32 (38%) were females. In patients of beta-thalassaemia major, 31 (62%) developed mixed donor chimerism (MC), 13 (26%) developed complete donor chimerism (CC) and 6 (12%) had graft failure. In aplastic anaemia, 17 patients (50%) achieved MC, 13 (38.2%) had CC and 4 (11.8%) developed graft failure. The combined frequency of mixed donor chimerism for both the diseases was 58.3%. D3S1358 was the most informative STR marker in these patients. Majority of the studied patients developed mixed donor chimerism following bone marrow transplantation, whereas only a minor percentage of the patients had graft failure. Analysis of D3S1358 was the most informative in assessing donor chimerism in patients who underwent BMT.

[Dietary patterns in college freshmen and its relation to bone mineral density].

PubMed

Wang, Sufang; Mu, Min; Zhao, Yan; Wang, Xiaoqin; Shu, Long; Li, Qingyan; Li, Yingchun

2012-07-01

In order to investigate the bone density of freshmen, and to analyze the association between dietary pattern and bone mineral density (BMD). A questionnaire survey on the situation of dietary pattern was conducted in 1414 freshmen. Effective dietary survey questionnaires and bone mineral density measurements were completed for 1319 participants. Bone mass was assessed by using an Ultrasound Bone Densitometer on the right calcaneus (CM-200, Furuno Electric Corporation, Japan), and the speed of sound (SOS, m/s) was used as an indicator for bone density. Factor analysis with varimax rotation was used to identify the dietary patterns. After adjusting for confounders, covariance with Bonferroni's was used to further examine the associations between dietary patterns and bone mineral density (BMD). (1) Four major dietary patterns were noticed. Western food pattern (high consumption in hamburger, fried food, nuts, biscuit, chocolate, cola, coffee, sugars). Animal protein pattern (high consumption in pork, mutton, beef, poultry meat, animal liver). Calcium pattern (high consumption in fresh fruits, eggs, fish and shrimps, kelp laver and sea fish, milk and dairy products, beans and bean products). Traditional Chinese pattern (high consumption in rice and grain, fresh fruits, fresh vegetables, pork). (2) No association was observed between the western food pattern and bone mineral density. High animal protein pattern showed lower SOS value compared with low animal protein pattern. High calcium pattern showed higher SOS value compared with low calcium pattern. High traditional Chinese pattern showed higher SOS value compared with the low traditional Chinese pattern. Dietary patterns are closely related with bone mineral density (BMD) of freshmen.

Importance of bioavailable calcium drinking water for the maintenance of bone mass in post-menopausal women.

PubMed

Costi, D; Calcaterra, P G; Iori, N; Vourna, S; Nappi, G; Passeri, M

1999-12-01

The aim of this research was to establish the importance of calcium intake through mineral water on vertebral bone density in women. To this purpose, we examined 255 women divided into two groups: those regularly drinking a high calcium content mineral water (group A; no.=175) and those using different type of water with a lower calcium content (group B; no.=80). Their dietary daily calcium intake was determined by means of a validated questionnaire (N.I.H. Consensus statement) and vertebral bone density was measured by Dual-Energy X-ray absorptiometry (Unigamma-plus ACN densitometer). Women in group A ingested a significantly higher quantity of calcium in water than women in group B (mean difference 258 mg; 95% confidence limits: 147-370 mg). The average bone density values were slightly but significantly higher in group A as compared to group B (mean+/-SD: 1.044+0,15 vs 1.002+0,14; p=0.03). In addition to age, BMI and menopausal status, calcium intake was a significant predictor of spinal BMD. These 4 variables explained about 35% of the spinal BMD variance. When the analysis was repeated separately for pre- and post-menopausal subjects, calcium remained a significant predictor in post-menopausal women (t=2.28; p=0.02), but not in premenopausal women. These results underline the importance of a lifelong daily calcium intake, resulting by the regular drinking of high bioavailable calcium water, in order to maintain bone mass after the menopause, in comparison to the use of a lower content calcium water.

Prediction of percent body fat in adult males using dual energy x-ray absorptiometry, skinfolds, and hydrostatic weighing.

PubMed

Clark, R R; Kuta, J M; Sullivan, J C

1993-04-01

The purpose of this study was to compare the prediction of percent body fat (%FAT) by dual energy x-ray absorptiometry (DXA), skinfolds (SF), and hydrostatic weighing (HW) in adult males. Subjects were 35 adult male Caucasians (mean +/- SD; age: 39.1 +/- 14.0 yr, height: 180.6 +/- 5.3 cm, weight: 81.0 +/- 11.1 kg). %FAT, determined by HW with residual volume determined via O2 dilution, served as the criterion. DXA %FAT was determined by the Norland XR-26 (XR-26) bone densitometer and by the SF equations of Jackson and Pollock (JP) (1978), and Lohman (LOH) (1981). Criterion referenced validation included analyzing mean (+/- SD) %FAT values using a one-way ANOVA for significance, comparison of mean differences (MD), correlations (r), standard error of estimates (SEE), and total errors (TE). Significant differences were found between means of each method. The r (0.91) and SEE (3.0 %FAT) for DXA compare favorably with the established SF methods of JP and LOH for predicting %FAT; however, DXA demonstrated the largest MD (3.9 %FAT) and TE (5.2 %FAT). Regression analysis yields HW = 0.79* DXA + 0.56. The results do not support earlier research that found no significant difference between HW and DXA %FAT in males. The study suggests the density of the fat-free body (DFFB) is not constant, and that the variation in bone mineral content affects the DFFB, which contributes to the differences between DXA and HW %FAT. We recommend further research to identify inconsistencies between manufacturers of DXA equipment in prediction of %FAT in males.

Does the use of ACE inhibitors or angiotensin receptor blockers affect bone loss in older men?

PubMed Central

Leung, J.; Zhang, Y. F.; Bauer, D.; Ensrud, K. E.; Barrett-Connor, E.; Leung, P. C.

2013-01-01

Summary In a prospective cohort study of 5,995 older American men (MrOS), users of angiotensin-converting enzyme (ACE) inhibitors had a small but significant increase in bone loss at the hip over 4 years after adjustment for confounders. Use of angiotensin II AT1 receptor blockers (ARB) was not significantly associated with bone loss. Introduction Experimental evidence suggests that angiotensin II promotes bone loss by its effects on osteoblasts. It is therefore plausible that ACE inhibitor and ARB may reduce rates of bone loss. The objective of this study is to examine the independent effects of ACE inhibitor and ARB on bone loss in older men. Methods Out of 5,995 American men (87.2%) aged ≥65 years, 5,229 were followed up for an average of 4.6 years in a prospective six-center cohort study—The Osteoporotic Fractures in Men Study (MrOS). Bone mineral densities (BMD) at total hip, femoral neck, and trochanter were measured by Hologic densitometer (QDR 4500) at baseline and year 4. Results Out of 3,494 eligible subjects with complete data, 1,166 and 433 subjects reported use of ACE inhibitors and ARBs, respectively. When compared with nonusers, continuous use of ACE inhibitors was associated with a small (0.004 g/cm2) but significant increase in the average rate of BMD loss at total hip and trochanter over 4 years after adjustment for confounders. Use of ARB was not significantly associated with bone loss. Conclusion Use of ACE inhibitors but not ARB may marginally increase bone loss in older men. PMID:22080379

Influence of obesity on bone mineral density in postmenopausal asthma patients undergoing treatment with inhaled corticosteroids.

PubMed

Yanik, Burcu; Ayrim, Aylin; Ozol, Duygu; Koktener, Asli; Gokmen, Derya

2009-01-01

The etiology of osteoporosis in asthma is complex as various factors contribute to its pathogenesis. The purpose of our study was to investigate the effects of obesity and inhaled steroids, as well as the severity and duration of asthma, on osteoporosis in postmenopausal asthma patients as compared to healthy controls. A total of 46 patients with asthma and 60 healthy female controls, all postmenopausal, were enrolled in our study. Bone mineral density was assessed at the lumbar spine and hip using a Lunar DPX-L densitometer. Bone mineral density (BMD) scores were comparable between the asthmatic and control groups, with average scores of 0.95 +/- 0.29 and 0.88 +/- 0.14 g/cm(2), respectively. Likewise, osteoporosis was diagnosed in a similar percentage of patients in the asthmatic (39.1%) and control (43.3%) groups. Bone fracture was identified in four patients with asthma (8.6%) and in six patients from the control group (10%). We could not detect any relationship between BMD and duration of asthma, asthma severity, inhaled steroids or body mass index (BMI). There was no difference between the two groups with respect to age or years since menopause. Although asthma patients were more likely to be overweight and presented higher BMD scores on average than the control subjects, these differences were not statistically significant. There is a slight positive protective effect of high BMI against osteoporosis in asthma patients, but this effect is overcome by time and menopause status. Therefore, the protective effect of obesity against osteoporosis in asthma patients seems to not be significant.

Evaluation of factors related to bone disease in Polish children and adolescents with cystic fibrosis.

PubMed

Sands, Dorota; Mielus, Monika; Umławska, Wioleta; Lipowicz, Anna; Oralewska, Beata; Walkowiak, Jarosław

2015-09-01

The aim of the study was to evaluate factors related to bone formation and resorption in Polish children and adolescents with cystic fibrosis and to examine the effect of nutritional status, biochemical parameters and clinical status on bone mineral density. The study group consisted of 100 children and adolescents with cystic fibrosis with a mean age 13.4 years old. Anthropometric measurements, included body height, body mass and body mass index (BMI); bone mineral densitometry and biochemical testing were performed. Bone mineral density was measured using a dual-energy X-ray absorption densitometer. Biochemical tests included serum calcium, phosphorus, parathyroid hormone and vitamin D concentrations, as well as 24-h urine calcium and phosphorus excretion. Pulmonary function was evaluated using FEV1%, and clinical status was estimated using the Shwachman-Kulczycki score. Standardized body height, body mass and BMI were significantly lower than in the reference population. Mean serum vitamin D concentration was decreased. Pulmonary disease was generally mild, with a mean FEV1% of 81%. Multivariate linear regression revealed that the only factors that had a significant effect on bone marrow density were BMI and FEV1%. There were no significant correlations between bone mineral density and the results of any of the biochemical tests performed. Nutritional status and bone mineral density were significantly decreased in children and adolescents with cystic fibrosis. In spite of abnormalities in biochemical testing, the factors that were found to have the strongest effect on bone mineral density were standardized BMI and clinical status. Copyright © 2015. Published by Elsevier Urban & Partner Sp. z o.o.

Body weight change since menopause and percentage body fat mass are predictors of subsequent bone mineral density change of the proximal femur in women aged 75 years and older: results of a 5 year prospective study.

PubMed

Blain, H; Carrière, I; Favier, F; Jeandel, C; Papoz, L

2004-07-01

Few studies have evaluated risk factors for bone loss in elderly women. We examined risk factors associated with a 5-year longitudinal change in bone mineral density (BMD) at the hip in healthy women aged 75 years and older. The BMD of 276 women from the French EPIDOS (Epidémiologie des Osteoporoses) study was assessed in Montpellier from 1992 to 1993 and again from 1997 to 1998. BMD was measured at the femoral neck, trochanter, and Ward's area using the same Lunar densitometer. We examined the relationship between clinical and behavioral factors at baseline and their variations during follow-up, with percentage BMD change adjusted for baseline BMD. Depending on the femur subregion studied, a significant decrease in BMD (exceeding the least significant difference, i.e., > 2.8 CV) was observed in 36.2% to 51.1% of women. Multivariate analysis showed that both postmenopausal weight change before baseline and baseline percentage of fat mass were positively correlated with BMD change at the Ward's triangle and the trochanter. Yearly absolute and relative weight changes over the follow-up period were significantly associated with change of trochanter and femoral neck BMD. Our results show that maintenance of body weight throughout the postmenopause period and body fat mass play protective roles against bone loss at the proximal femur in women aged 75 years and older and suggest the value in including assessment of weight change throughout postmenopause and percentage body fat mass in screening programs for elderly women who are at higher risk of accelerated bone loss.

Macular Pigment Optical Density Measured by Heterochromatic Modulation Photometry

PubMed Central

Huchzermeyer, Cord; Schlomberg, Juliane; Welge-Lüssen, Ulrich; Berendschot, Tos T. J. M.; Pokorny, Joel; Kremers, Jan

2014-01-01

Purpose To psychophysically determine macular pigment optical density (MPOD) employing the heterochromatic modulation photometry (HMP) paradigm by estimating 460 nm absorption at central and peripheral retinal locations. Methods For the HMP measurements, two lights (B: 460 nm and R: 660 nm) were presented in a test field and were modulated in counterphase at medium or high frequencies. The contrasts of the two lights were varied in tandem to determine flicker detection thresholds. Detection thresholds were measured for different R:B modulation ratios. The modulation ratio with minimal sensitivity (maximal threshold) is the point of equiluminance. Measurements were performed in 25 normal subjects (11 male, 14 female; age: 30±11 years, mean ± sd) using an eight channel LED stimulator with Maxwellian view optics. The results were compared with those from two published techniques – one based on heterochromatic flicker photometry (Macular Densitometer) and the other on fundus reflectometry (MPR). Results We were able to estimate MPOD with HMP using a modified theoretical model that was fitted to the HMP data. The resultant MPODHMP values correlated significantly with the MPODMPR values and with the MPODHFP values obtained at 0.25° and 0.5° retinal eccentricity. Conclusions HMP is a flicker-based method with measurements taken at a constant mean chromaticity and luminance. The data can be well fit by a model that allows all data points to contribute to the photometric equality estimate. Therefore, we think that HMP may be a useful method for MPOD measurements, in basic and clinical vision experiments. PMID:25354049

Macular pigment optical density measured by heterochromatic modulation photometry.

PubMed

Huchzermeyer, Cord; Schlomberg, Juliane; Welge-Lüssen, Ulrich; Berendschot, Tos T J M; Pokorny, Joel; Kremers, Jan

2014-01-01

To psychophysically determine macular pigment optical density (MPOD) employing the heterochromatic modulation photometry (HMP) paradigm by estimating 460 nm absorption at central and peripheral retinal locations. For the HMP measurements, two lights (B: 460 nm and R: 660 nm) were presented in a test field and were modulated in counterphase at medium or high frequencies. The contrasts of the two lights were varied in tandem to determine flicker detection thresholds. Detection thresholds were measured for different R:B modulation ratios. The modulation ratio with minimal sensitivity (maximal threshold) is the point of equiluminance. Measurements were performed in 25 normal subjects (11 male, 14 female; age: 30 ± 11 years, mean ± sd) using an eight channel LED stimulator with Maxwellian view optics. The results were compared with those from two published techniques - one based on heterochromatic flicker photometry (Macular Densitometer) and the other on fundus reflectometry (MPR). We were able to estimate MPOD with HMP using a modified theoretical model that was fitted to the HMP data. The resultant MPODHMP values correlated significantly with the MPODMPR values and with the MPODHFP values obtained at 0.25° and 0.5° retinal eccentricity. HMP is a flicker-based method with measurements taken at a constant mean chromaticity and luminance. The data can be well fit by a model that allows all data points to contribute to the photometric equality estimate. Therefore, we think that HMP may be a useful method for MPOD measurements, in basic and clinical vision experiments.

[Body profile and physical and cognitive function by age in ambulatory elderly women from the city of Córdoba].

PubMed

Asaduroglu, Ana V; Tablada, M; Cosiansi Bai, J; Carrillo, M; Canale, M; Gallerano, R

2015-01-01

Aging produces body changes such as redistribution of fat and loss of muscle mass and strength, predisposing to fragility, functional impairment and disability. To analyze the relationship between body profile and physical and cognitive function by age in in ambulatory elderly women from the city of Córdoba. 178 healthy older women (OW) ≥60 years free living were evaluated attending centers of retirees and day homes in the city of Córdoba. We evaluated body profile from: skeletal muscle mass index (SMMI), relative body adiposity (RBA) -dual X-ray absorptiometry- and muscle strength (MS) -dynamometry-. Categories: normal/(N) sarcopenia/(SP), obesity/(OB), sarcopenic obesity/(SO); Physical function: with/without physical limitation (PL); cognitive function: with/without cognitive impairment (CI). Lunar Prodigy Densitometer and Smedley dynamometer, Lawton and Brody and Minimental Examination of Folstein scales. SO prevailed and increased with age, contrary to OB. Most of the OW did not PL or CI. Only 2.25% had low SMMI and 48.3% dynapenia. 76.97% had elevated RBA. The SP - obese or not - had greater PL and CI. CI frequency doubled to PL (15.17% versus 6.74%). We found negative correlations and significant associations between age and MS (r= -0.279; p=0.0001), physical function (r=-0.164; p=0.0283) and cognitive function (r=-0.028; p=0.0002). In this group of healthy OW the dynapenia was responsible for the observed SP, not low SMMI. The OW with SP had more PL and CI, and increased with age.

TU-F-201-00: Radiochromic Film Dosimetry Update

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Since the introduction of radiochromic films (RCF) for radiation dosimetry, the scope of RCF dosimetry has expanded steadily to include many medical applications, such as radiation therapy and diagnostic radiology. The AAPM Task Group (TG) 55 published a report on the recommendations for RCF dosimetry in 1998. As the technology is advancing rapidly, and its routine clinical use is expanding, TG 235 has been formed to provide an update to TG-55 on radiochromic film dosimetry. RCF dosimetry applications in clinical radiotherapy have become even more widespread, expanding from primarily brachytherapy and radiosurgery applications, and gravitating towards (but not limited to)more » external beam therapy (photon, electron and protons), such as quality assurance for IMRT, VMAT, Tomotherapy, SRS/SRT, and SBRT. In addition, RCF applications now extend to measurements of radiation dose in particle beams and patients undergoing medical exams, especially fluoroscopically guided interventional procedures and CT. The densitometers/scanners used for RCF dosimetry have also evolved from the He-Ne laser scanner to CCD-based scanners, including roller-based scanner, light box-based digital camera, and flatbed color scanner. More recently, multichannel RCF dosimetry introduced a new paradigm for external beam dose QA for its high accuracy and efficiency. This course covers in detail the recent advancements in RCF dosimetry. Learning Objectives: Introduce the paradigm shift on multichannel film dosimetry Outline the procedures to achieve accurate dosimetry with a RCF dosimetry system Provide comprehensive guidelines on RCF dosimetry for various clinical applications One of the speakers has a research agreement from Ashland Inc., the manufacturer of Gafchromic film.« less

TU-F-201-01: General Aspects of Radiochromic Film Dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niroomand-Rad, A.

Since the introduction of radiochromic films (RCF) for radiation dosimetry, the scope of RCF dosimetry has expanded steadily to include many medical applications, such as radiation therapy and diagnostic radiology. The AAPM Task Group (TG) 55 published a report on the recommendations for RCF dosimetry in 1998. As the technology is advancing rapidly, and its routine clinical use is expanding, TG 235 has been formed to provide an update to TG-55 on radiochromic film dosimetry. RCF dosimetry applications in clinical radiotherapy have become even more widespread, expanding from primarily brachytherapy and radiosurgery applications, and gravitating towards (but not limited to)more » external beam therapy (photon, electron and protons), such as quality assurance for IMRT, VMAT, Tomotherapy, SRS/SRT, and SBRT. In addition, RCF applications now extend to measurements of radiation dose in particle beams and patients undergoing medical exams, especially fluoroscopically guided interventional procedures and CT. The densitometers/scanners used for RCF dosimetry have also evolved from the He-Ne laser scanner to CCD-based scanners, including roller-based scanner, light box-based digital camera, and flatbed color scanner. More recently, multichannel RCF dosimetry introduced a new paradigm for external beam dose QA for its high accuracy and efficiency. This course covers in detail the recent advancements in RCF dosimetry. Learning Objectives: Introduce the paradigm shift on multichannel film dosimetry Outline the procedures to achieve accurate dosimetry with a RCF dosimetry system Provide comprehensive guidelines on RCF dosimetry for various clinical applications One of the speakers has a research agreement from Ashland Inc., the manufacturer of Gafchromic film.« less

Distribution of withaferin A, an anticancer potential agent, in different parts of two varieties of Withania somnifera (L.) Dunal. grown in Sri Lanka.

PubMed

Siriwardane, A S; Dharmadasa, R M; Samarasinghe, Kosala

2013-02-01

Withania somnifera (L.) Dunal. (Family: Solanaceae) is a therapeutically important medicinal plant in traditional and Ayurveda systems of medicine in Sri Lanka. Witheferin A, is a potential anticancer compound found in W. somnifera. In the present study, attempts have been made to compare witheferin A content, in different parts of (root, stem, bark, leaf) two varieties of (LC1 and FR1) W. somnifera grown in same soil and climatic conditions. Ground sample (1g) of leaves, bark, stem and roots of two W. somnifera varieties were extracted with CHCl3 three times. Thin Layer Chromatographic analysis (TLC) of withaferin A in both plant extracts were performed on pre-coated Silica gel 60 GF254 plates in hexane: ethyl acetate: methanol (2: 14: 1) mobile phase. Densitometer scanning was performed at lambda(max) = 215 nm. HPLC of W. somnifera extracts was performed using Kromasil C18 reverse phase column. Both varieties of W. somnifera differed in withaferin A. After visualizing TLC plates with vanillin-sulphuric acid leaf and bark extracts of both varieties showed high intensity purple colour spots (R(f) 0.14) than in stem and roots. The highest amount of withaferin A (3812 ppm) was observed in leaves of variety LC1 while the lowest amount was observed in roots of variety FR1 (5 ppm). According to the results it could be concluded that content of Witheferin A was vary leaf > bark > stem > roots in both varieties. Therefore, there is a high potential of incorporation of leaves and bark of W. somnifera for the preparation of Ayurveda drug leading to anticancer activity instead of roots.

Stability-indicating methods for the determination of piretanide in presence of the alkaline induced degradates.

PubMed

Youssef, Nadia F

2005-10-04

Stability-indicating high performance liquid chromatography (HPLC), thin-layer chromatography (TLC) and first-derivative of ratio spectra (1DD) methods are developed for the determination of piretanide in presence of its alkaline induced degradates. HPLC method depends on separation of piretanide from its degradates on mu-Bondapak C18 column using methanol:water:acetic acid (70:30:1, v/v/v) as a mobile phase at flow rate 1.0 ml/min and UV detector at 275 nm. TLC densitometic method is based on the difference in Rf-values between the intact drug and its degradates on thin-layer silica gel. Iso-propanol:ammonia 33% (8:2, v/v) was used as a developing mobile phase and the chromatogram was scanned at 275 nm. The derivative of ratio spectra method (1DD) depends on the measurement of the absorbance at 288 nm in the first-derivative of ratio spectra for the determination of the cited drug in the presence of its degradates. Calibration graphs of the three suggested methods are linear in the concentration ranges 0.02-0.3 microg/20 microl, 0.5-10 microg/spot and 5-50 microg/ml, with mean percentage recovery 99.27+/-0.52, 99,17+/-1.01 and 99.65+/-1.01%, respectively. The three proposed methods were successfully applied for the determination of piretanide in bulk powder, laboratory-prepared mixtures and pharmaceutical dosage form with good accuracy and precision. The results were statistically analyzed and compared with those obtained by the official method. Validation of the method was determined with favourable specificity, linearity, precision, and accuracy was assessed by applying the standard addition technique.

Effect of High Impact or Non-impact Loading Activity on Bone Bending Stiffness and Mineral Density

NASA Technical Reports Server (NTRS)

Liang, Michael T. C.; Arnnud, Sara B.; Steele, Charles R.; Moreno, Alexjandro

2003-01-01

Material properties of conical bone, including mineral density (BMD) and its geometry is closely related to its load-carrying capacity. These two primary components determine the strength of conical bone. High impact loading involving acceleration and deceleration movements used in gymnastics induce higher BMD of the affected bone compared to the non-impact acceleration and deceleration movements used in swimming. Study of these two groups of athletes on bone bending stiffness has not been reported. The purpose of this study was to compare differences in bone bending stiffness and BMD between competitive female synchronized swimmers and female gymnasts. Thirteen world class female synchronized swimmers (SYN) and 8 female gymnasts (GYM), mean age 21 +/- 2.9 yr. were recruited for this study. We used a mechanical response tissue analyzer (Gaitscan, NJ) to calculate EI, where E is Young's modulus of elasticity and I is the cross-sectional moment of inertia. EI was obtained from tissue response to a vibration probe placed directly on the skin of the mid-region of tibia and ulna. BMD of the heel and wrist were measured with a probe densitometer (PIXI, Lunor, WI). The SYN were taller than (p < 0.05) the GYM but weighed the same as the GYM. EI obtained from tibia and ulna of the SYN (291 +/- 159 and 41 +/- 19.4, respectively) were not significantly different from thc GYM (285 +/- 140 and 44 +/- 18.3, respectively). BMD of the heel and wrist in GYM were higher than in SYN (p < 0.001). High impact weight-bearing activities promote similar bone strength but greater BMD response than non-impact activities performed in a buoyant environment.

Use of ultrasonography in the diagnosis of osteomalacia: preliminary results on experimental osteomalacia in the rat.

PubMed

Luisetto, G; Camozzi, V; De Terlizzi, F; Moschini, G; Ballanti, P

1999-03-01

This study was performed to investigate the ability of ultrasonographic technique to distinguish osteomalacia from normal bone with the same mineral content. Ten rats with experimentally induced osteomalacia (group A) and 12 control rats having similar body size and weight (group B) were studied. Histomorphometric analysis confirmed the presence of osteomalacia in two rats from group A and showed normally mineralized bone in two rats from group B. Whole body bone mineral density, measured by dual-energy x-ray absorptiometry, was similar in the two groups (86 +/- 6 mg/cm2 in group A and 89 +/- 4 mg/cm2 in group B). The velocity of the ultrasound beam in bone was measured by densitometer at the first caudal vertebra of each rat. The velocity was measured when the first peak of the waveform reached a predetermined minimum amplitude value (amplitude-dependent speed of sound) as well as at the lowest point of this curve before it reaches the predetermined minimum amplitude (first minimum speed of sound). Although the amplitude-dependent speed of sound was similar in the two groups (1381.9 +/- 11.8 m/s in group A and 1390.9 +/- 17.8 m/s in group B), the first minimum speed of sound was clearly different (1446.1 +/- 8.9 m/s in group A and 1503.3 +/- 10.9 m/s in group B; P < 0.001). This study shows that ultrasonography could be used to identify alterations in bone quality, such as osteomalacia, but further studies need to be carried out before this method can be introduced into clinical practice.

Influence of bone density on the cement fixation of femoral hip resurfacing components.

PubMed

Bitsch, Rudi G; Jäger, Sebastian; Lürssen, Marcus; Loidolt, Travis; Schmalzried, Thomas P; Clarius, Michael

2010-08-01

In clinical outcome studies, small component sizes, female gender, femoral shape, focal bone defects, bad bone quality, and biomechanics have been associated with failures of resurfacing arthroplasties. We used a well-established experimental setup and human bone specimens to analyze the effects of bone density on cement fixation of femoral hip resurfacing components. Thirty-one fresh frozen femora were prepared for resurfacing using the original instruments. ASR resurfacing prostheses were implanted after dual-energy X-ray densitometer scans. Real-time measurements of pressure and temperature during implantation, analyses of cement penetration, and measurements of micro motions under torque application were performed. The associations of bone density and measurement data were examined calculating regression lines and multiple correlation coefficients; acceptability was tested with ANOVA. We found significant relations between bone density and micro motion, cement penetration, cement mantle thickness, cement pressure, and interface temperature. Mean bone density of the femora was 0.82 +/- 0.13 g/cm(2), t-score was -0.7 +/- 1.0, and mean micro motion between bone and femoral resurfacing component was 17.5 +/- 9.1 microm/Nm. The regression line between bone density and micro motion was equal to -56.7 x bone density + 63.8, R = 0.815 (p < 0.001). Bone density scans are most helpful for patient selection in hip resurfacing, and a better bone quality leads to higher initial component stability. A sophisticated cementing technique is recommended to avoid vigorous impaction and incomplete seating, since increasing bone density also results in higher cement pressures, lower cement penetration, lower interface temperatures, and thicker cement mantles. Copyright 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popp, R.A.; Marsh, C.L.; Skow, L.C.

Hemoglobins of mouse embryos at 11.5 through 16.5 days of gestation were separated by electrophoresis on cellulose acetate and quantitated by a scanning densitometer to study the effects of two radiation-induced mutations on the expression of embryonic hemoglobin genes in mice. Normal mice produce three kinds of embryonic hemoglobins. In heterozygous ..cap alpha..-thalassemic embryos, expression of EI (x/sub 2/y/sub 2/) and EII (..cap alpha../sub 2/y/sub 2/) is deficient because the x- and ..cap alpha..-globin genes of one of the allelic pairs of Hba on chromosome 11 was deleted or otherwise inactivated by X irradiation. Simultaneous inactivation of the x- andmore » ..cap alpha..-globin genes indicates that these genes must be closely linked. Reduced x- and ..cap alpha..-chain synthesis results in an excess of y chains that associate as homotetramers. This unique y/sub 4/ hemoglobin also appears in ..beta..-duplication embryos where excess y chains are produced by the presence of three rather than two functional alleles of y- and ..beta..-globin genes. In double heterozygotes, which have a single functional allele of x- and ..cap alpha..-globin genes and three functional alleles of y- and ..beta..-globin genes, synthesis of ..cap alpha.. and non-..cap alpha.. chains is severely imbalanced and half of the total hemoglobin is y/sub 4/. Mouse y/sub 4/ has a high affinity for oxygen, P/sub 50/ of less than 10 mm Hg, but it lacks cooperativity so is inefficient for oxygen transport. The death of double heterozygotes in late fetal or neonatal life may be in large part to oxygen deprivation to the tissues.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiu-Tsao, S.

Since the introduction of radiochromic films (RCF) for radiation dosimetry, the scope of RCF dosimetry has expanded steadily to include many medical applications, such as radiation therapy and diagnostic radiology. The AAPM Task Group (TG) 55 published a report on the recommendations for RCF dosimetry in 1998. As the technology is advancing rapidly, and its routine clinical use is expanding, TG 235 has been formed to provide an update to TG-55 on radiochromic film dosimetry. RCF dosimetry applications in clinical radiotherapy have become even more widespread, expanding from primarily brachytherapy and radiosurgery applications, and gravitating towards (but not limited to)more » external beam therapy (photon, electron and protons), such as quality assurance for IMRT, VMAT, Tomotherapy, SRS/SRT, and SBRT. In addition, RCF applications now extend to measurements of radiation dose in particle beams and patients undergoing medical exams, especially fluoroscopically guided interventional procedures and CT. The densitometers/scanners used for RCF dosimetry have also evolved from the He-Ne laser scanner to CCD-based scanners, including roller-based scanner, light box-based digital camera, and flatbed color scanner. More recently, multichannel RCF dosimetry introduced a new paradigm for external beam dose QA for its high accuracy and efficiency. This course covers in detail the recent advancements in RCF dosimetry. Learning Objectives: Introduce the paradigm shift on multichannel film dosimetry Outline the procedures to achieve accurate dosimetry with a RCF dosimetry system Provide comprehensive guidelines on RCF dosimetry for various clinical applications One of the speakers has a research agreement from Ashland Inc., the manufacturer of Gafchromic film.« less

Reliability of analysis of the bone mineral density of the second and fifth metatarsals using dual-energy x-ray absorptiometry (DXA).

PubMed

Pritchard, N Stewart; Smoliga, James M; Nguyen, Anh-Dung; Branscomb, Micah C; Sinacore, David R; Taylor, Jeffrey B; Ford, Kevin R

2017-01-01

Metatarsal fractures, especially of the fifth metatarsal, are common injuries of the foot in a young athletic population, but the risk factors for this injury are not well understood. Dual-energy x-ray absorptiometry (DXA) provides reliable measures of regional bone mineral density to predict fracture risk in the hip and lumbar spine. Recently, sub-regional metatarsal reliability was established in fresh cadaveric specimens and associated with ultimate fracture force. The purpose of this study was to assess the reliability of DXA bone mineral density measurements of sub-regions of the second and fifth metatarsals in a young, active population. Thirty two recreationally active individuals participated in the study, and the bone density of the second (2MT) and fifth (5MT) metatarsals of each subject was measured using a Hologic QDR x-ray bone densitometer. Scans were analyzed separately by two raters, and regional bone mineral density, bone mineral content, and area measurements were calculated for the proximal, shaft, and distal regions of the bone. Intra-rater, inter-rater, and scan-rescan reliability were then determined for each region. Proximal and shaft bone mineral density measurements of the second and fifth metatarsal were reliable. ICC's were variable across regions and metatarsals, with the distal region being the poorest. Bone mineral density measurements of the metatarsals may be a better indicator of fracture risk of the metatarsals than whole body measurements. A reliable method for measuring the regional bone mineral densities of the metatarsals was found. However, inter-rater reliability and scan-rescan reliability for the distal regions were poor. Future research should examine the relationship between DXA bone mineral density measurements and fracture risk at the metatarsals.

Approach to the Child with Fractures

PubMed Central

Boyce, Alison M.

2011-01-01

Evaluation of the child with fractures is challenging, as no clear guidelines exist to distinguish traumatic from pathological fractures. Although most fractures in childhood are benign, recurrent fractures may be associated with a wide variety of primary skeletal diseases as well as secondary causes, necessitating a careful history and physical exam to guide the evaluation. There is no “gold standard” for the evaluation and treatment of children with fractures and low bone mineral density (BMD); therefore, the diagnosis of osteoporosis in a pediatric patient should be made using a combination of clinical and radiographic features. Interpretation of bone densitometry in growing patients presents a unique set of challenges because areal BMD measured by dual-energy x-ray absorptiometry depends on multiple dynamic variables. Interpretation of pediatric dual-energy x-ray absorptiometry should be based on Z-scores (sd scores compared to age, sex, and ethnicity-matched controls), using normative databases specific to the brand of densitometer and the patient population. Given the skeleton's ability to recover from low BMD through modeling and remodeling, optimizing management of underlying conditions leading to bone fragility is the initial step. Conservative measures including calcium and vitamin D supplementation and weight-bearing physical activity are important interventions that should not be overlooked. The use of bisphosphonates in children and adolescents is controversial due to lack of long-term efficacy and safety data and should be limited to clinical trials and compassionate therapy in children with significantly compromised quality of life. Close monitoring is required, and further study is necessary to assess their long-term safety and efficacy in children. PMID:21734001

Subcutaneous administration of insulin-like growth factor (IGF)-II/IGF binding protein-2 complex stimulates bone formation and prevents loss of bone mineral density in a rat model of disuse osteoporosis

NASA Technical Reports Server (NTRS)

Conover, Cheryl A.; Johnstone, Edward W.; Turner, Russell T.; Evans, Glenda L.; John Ballard, F. John; Doran, Patrick M.; Khosla, Sundeep

2002-01-01

Elevated serum levels of insulin-like growth factor binding protein-2 (IGFBP-2) and a precursor form of IGF-II are associated with marked increases in bone formation and skeletal mass in patients with hepatitis C-associated osteosclerosis. In vitro studies indicate that IGF-II in complex with IGFBP-2 has high affinity for bone matrix and is able to stimulate osteoblast proliferation. The purpose of this study was to determine the ability of the IGF-II/IGFBP-2 complex to increase bone mass in vivo. Osteopenia of the femur was induced by unilateral sciatic neurectomy in rats. At the time of surgery, 14-day osmotic minipumps containing vehicle or 2 microg IGF-II+9 microg IGFBP-2/100g body weight/day were implanted subcutaneously in the neck. Bone mineral density (BMD) measurements were taken the day of surgery and 14 days later using a PIXImus small animal densitometer. Neurectomy of the right hindlimb resulted in a 9% decrease in right femur BMD (P<0.05 vs. baseline). This loss in BMD was completely prevented by treatment with IGF-II/IGFBP-2. On the control limb, there was no loss of BMD over the 14 days and IGF-II/IGFBP-2 treatment resulted in a 9% increase in left femur BMD (P<0.05). Bone histomorphometry indicated increases in endocortical and cancellous bone formation rates and in trabecular thickness. These results demonstrate that short-term administration of the IGF-II/IGFBP-2 complex can prevent loss of BMD associated with disuse osteoporosis and stimulate bone formation in adult rats. Furthermore, they provide proof of concept for a novel anabolic approach to increasing bone mass in humans with osteoporosis.

Quantitative TLC-Image Analysis of Urinary Creatinine Using Iodine Staining and RGB Values.

PubMed

Kerr, Emily; West, Caroline; Kradtap Hartwell, Supaporn

2016-04-01

Digital image analysis of the separation results of colorless analytes on thin-layer chromatography (TLC) plates usually involves using specially tailored software to analyze the images generated from either a UV scanner or UV lamp station with a digital camera or a densitometer. Here, a low-cost alternative setup for quantitative TLC-digital image analysis is demonstrated using a universal staining reagent (iodine vapor), an office scanner and a commonly available software (Microsoft Paint) for analysis of red, green and blue colors (RGB values). Urinary creatinine is used as a model analyte to represent a sample in complicated biological matrices. Separation was carried out on a silica gel plate using a butanol-NH4OH-H2O (40 : 10 : 50, v/v) mobile phase with a 6-cm solvent front. It is important that the TLC plate be stained evenly and with sufficient staining time. Staining the TLC plate in a 23.4 × 18.8 × 6.8 cm chamber containing about 70 g iodine crystals yielded comparable results for the staining times of 30-60 min. The Green value offered the best results in the linear working range (0.0810-0.9260 mg/mL) and precision (2.03% RSD, n = 10). The detection limit was found to be 0.24 µg per 3 µL spot. Urinary creatinine concentrations determined by TLC-digital image analysis using the green value calibration graph agree well with results obtained from high-pressure liquid chromatography (HPLC). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosen, B. S., E-mail: bsrosen@wisc.edu; Hammer, C. G.; Kunugi, K. A.

Purpose: To evaluate a prototype densitometer traceable to primary optical standards and compare its performance to an EPSON Expression{sup ®} 10000XL flatbed scanner (the Epson) for quantitative radiochromic film (RCF) dosimetry. Methods: A prototype traceable laser densitometry system (LDS) was developed to mitigate common film scanning artifacts, such as positional scan dependence and high noise in low-dose regions, by performing point-based measurements of RCF suspended in free-space using coherent light. The LDS and the Epson optical absorbance scales were calibrated up to 3 AU, using reference materials calibrated at a primary standards laboratory and a scanner calibration factor (SCF). Calibratedmore » optical density (OD) was determined for 96 Gafchromic{sup ®} EBT3 film segments before and after irradiation to one of 16 dose levels between 0 and 10 Gy, exposed to {sup 60}Co in a polymethyl-methacrylate (PMMA) phantom. The sensitivity was determined at each dose level and at two rotationally orthogonal readout orientations to obtain the sensitometric response of each RCF dosimetry system. LDS rotational scanning dependence was measured at nine angles between 0°and 180°, due to the expected interference between coherent light and polarizing EBT3 material. The response curves were fit to the analytic functions predicted by two physical response models: the two-parameter single-hit model and the four-parameter percolation model. Results: The LDS and the Epson absorbance measurements were linear to primary optical standards to within 0.2% and 0.3% up to 2 and 1 AU, respectively. At higher densities, the LDS had an over-response (2.5% at 3 AU) and the Epson an under-response (3.1% and 9.8% at 2 and 3 AU, respectively). The LDS and the Epson SCF over the applicable range were 0.968% ± 0.2% and 1.561% ± 0.3%, respectively. The positional scan dependence was evaluated on each digitizer and shown to be mitigated on the LDS, as compared to the Epson. Maximum

Densitometric evaluation of three intra-oral radiographic films.

PubMed

Seeliger, J E; Prinsloo, J J

1989-05-01

The radiographic, or diagnostic, quality of the processed radiograph depends upon a number of factors, one of the most important being the characteristics of the film. The purpose of this study was to determine which of three intra-oral radiographic films, obtainable in this country, would give the best results in terms of density range, speed, contrast and base plus fog values. Agfa Dentus, Flow X-Ray and Kodak (all speed group D films) were exposed, using a calibrated G.E. 1000 x-ray generator at 65 kVp, 10 mA and 50 impulses (1 second) exposure time. The target-film-distance was 40 cm, the total filtration 2.0 mm Aluminium and the half-value layer 2.7 mm Aluminium equivalent. An aluminium step-wedge with 8 steps, in steps of 1.5 mm, and a natural premolar tooth, with a carious lesion, embedded in acrylic, were used as phantoms. An 8 mm-thick layer of base-plate wax and a 3 mm-thick lead plate were used to simulate tissue-scatter and prevent back-scatter, respectively. To determine the base plug fog value, an unexposed film from the same batch was processed simultaneously with each of the three films evaluated. All processing was done in a Dürr AC 245 L processor with automatic replenishment and a 6-minute cycle. The processing chemicals, viz., Kolchem High Stability X-ray developer and fixer, were mixed and used in strict accordance with the manufacturer's recommendations. The radiographic densities of each step of the step-wedge, and of carious and normal dentine of the phantom tooth, were determined by means of an RMI Digital Densitometer.(ABSTRACT TRUNCATED AT 250 WORDS)

[Relationship of GSTP1 lower expression and multidrug resistance reversing of curcumin on human colon carcinoma cells].

PubMed

Li, He; Li, Lei

2015-08-11

To explore the proteomic differences among with and without curcumin treatment of vincristine-resistance HCT-8/VCR cells of human colon carcinoma by using mass spectrometry and two-dimensional gel electrophore-sis (2-DE). The total proteins of the both groups were extracted from serum were run in immobilized pH gradient isoelectic focusing (IPG-IEF) at the first dimension.The proteins pots in gels were visualized by silver staining protocol, scanned by using a molecular imager GS-800 calibrated densitometer. The differentially expressed proteins were identified and analyzed by PDQuest 8.0 software. The diferentially displayed protein spots were searched and identifiyed by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF-MS), the interested proteins were further validated by RT-PCR and Western blot. The 2-DE HCT-8/VCR cells patterns were acquired with clear background, well-resolution and reproduction. And 1 070±96 protein spots were detected in control HCT-8/VCR cells and 1 030±69 in curcumin-treated HCT-8/VCR cells. Twenty-nine differential protein spots were found to be differentially expressed. Glutathione S-transferase pi1 gene (GSTP1), a diferentiaI expression protein was identified which one of these proteins. RT-PCR and Western blotting results showed that the expressions of GSTP1 mRNA (0.49±0.09) and protein (0.29±0.07) in curcumin-treated group were significantly lower than in control group (GSTP1 mRNA 1.19±0.21 and protein 0.70±0.13, both P<0.05), indicating that curcumin down regulated these expressions. The suppression of GSTP1 by curcumin could enhance the vincristine chemosensitivity in HCT-8/VCR. GSTP1 overexpression may be involved in the vincristine -resistance of human colon carcinoma cells.

Macular pigment levels do not influence C-Quant retinal straylight estimates in young Caucasians.

PubMed

Beirne, Raymond O

2014-03-01

Individuals with higher than normal levels of macular pigment optical density (MPOD) are less affected by disability glare, when using glare source lights with a strong short-wavelength component. The aim of this study was to investigate whether estimates of retinal straylight from the Oculus Cataract Quantifier (C-Quant), which corresponds to disability glare, are associated with estimates of macular pigment levels in young Caucasian eyes. Thirty-seven Caucasian individuals (aged 19 to 40 years) with good visual acuity, free from ocular disease and with clear ocular media participated. Macular pigment optical density was measured at 0.5 degrees eccentricity from the foveal centre using a heterochromatic flicker photometry-based densitometer instrument from MacularMetrics. Retinal straylight was estimated using the C-Quant, a commercially available device, which uses a psychophysical compensation comparison method. Mean MPOD was 0.39 ± 0.18 log units (range zero to 0.80) and was not significantly related to age (r = -0.07, p = 0.66). Mean straylight parameter (s) was 1.01 ± 0.09 log units (range 0.86 to 1.21) and was not significantly related to age (r = -0.03, p = 0.86). Although there was a small tendency for straylight measurements to be reduced in individuals with higher levels of MPOD, there was no statistically significant relationship between retinal straylight and MPOD (r = -0.17, p = 0.30). Ocular straylight, estimated by the Oculus C-Quant, is little influenced by macular pigment optical density. As the C-Quant uses balanced (white) lights, it is suggested that the previous findings on the effect of macular pigment critically depend on the use of blue-dominant glare sources. © 2013 The Author. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.

Modifying the baricity of local anesthetics for spinal anesthesia by temperature adjustment: model calculations.

PubMed

Heller, Axel R; Zimmermann, Katrin; Seele, Kristin; Rössel, Thomas; Koch, Thea; Litz, Rainer J

2006-08-01

Although local anesthetics (LAs) are hyperbaric at room temperature, density drops within minutes after administration into the subarachnoid space. LAs become hypobaric and therefore may cranially ascend during spinal anesthesia in an uncontrolled manner. The authors hypothesized that temperature and density of LA solutions have a nonlinear relation that may be described by a polynomial equation, and that conversion of this equation may provide the temperature at which individual LAs are isobaric. Density of cerebrospinal fluid was measured using a vibrating tube densitometer. Temperature-dependent density data were obtained from all LAs commonly used for spinal anesthesia, at least in triplicate at 5 degrees, 20 degrees, 30 degrees, and 37 degrees C. The hypothesis was tested by fitting the obtained data into polynomial mathematical models allowing calculations of substance-specific isobaric temperatures. Cerebrospinal fluid at 37 degrees C had a density of 1.000646 +/- 0.000086 g/ml. Three groups of local anesthetics with similar temperature (T, degrees C)-dependent density (rho) characteristics were identified: articaine and mepivacaine, rho1(T) = 1.008-5.36 E-06 T2 (heavy LAs, isobaric at body temperature); L-bupivacaine, rho2(T) = 1.007-5.46 E-06 T2 (intermediate LA, less hypobaric than saline); bupivacaine, ropivacaine, prilocaine, and lidocaine, rho3(T) = 1.0063-5.0 E-06 T (light LAs, more hypobaric than saline). Isobaric temperatures (degrees C) were as follows: 5 mg/ml bupivacaine, 35.1; 5 mg/ml L-bupivacaine, 37.0; 5 mg/ml ropivacaine, 35.1; 20 mg/ml articaine, 39.4. Sophisticated measurements and mathematic models now allow calculation of the ideal injection temperature of LAs and, thus, even better control of LA distribution within the cerebrospinal fluid. The given formulae allow the adaptation on subpopulations with varying cerebrospinal fluid density.

Homocysteine, folate, and vitamin B12 levels and vertebral fracture risk in postmenopausal women.

PubMed

El Maghraoui, Abdellah; Ghozlani, Imad; Mounach, Aziza; Rezqi, Asmaa; Oumghar, Khalid; Achemlal, Lahsen; Bezza, Ahmed; Ouzzif, Zhor

2012-01-01

The objective of this study was to examine the influence of homocysteine, vitamin B(12), and folate on the prevalence of asymptomatic osteoporotic vertebral fractures (VFs) using vertebral fracture assessment (VFA) in postmenopausal women. The study cohort consisted of 188 consecutive postmenopausal women (mean age, weight, and body mass index of 57.9 ± 8.5 [41-91]yr, 74.4 ± 13.5 [38-150]kg, and 30.4 ± 5.2 [17.1-50.7]kg/m(2), respectively). Lateral VFA images and scans of the lumbar spine and proximal femur were obtained using a Lunar Prodigy Vision densitometer (GE Healthcare Inc., Waukesha, WI). VFs were defined using a combination of Genant's semiquantitative approach and morphometry. Fifty-eight (30.9%) patients had densitometric osteoporosis. VFs were identified using VFA in 76 (40.4%) patients: 61 women had grade 1 VFs and 15 had grade 2 or 3 VFs. No statistical difference was shown between the 3 groups (absence of VFs, VFs grade 1, and VFs grade 2/3) concerning the biological parameters. Comparison of patients according to quartiles of homocysteine levels showed that women in the highest quartile were older and had a lower bone mineral density (BMD); however, the prevalence of VFs was not statistically different from that of women in the other quartile groups. Stepwise regression analysis showed that homocysteine was not independently associated with the presence of VFs, which was mainly related to the osteoporotic status. Although a weak association was observed between hyperhomocysteinemia and low BMD and a trend to higher prevalence of grade 2/3 VFs was observed, our study did not confirm that homocysteine, vitamin B(12), and folate status are important determinants of prevalent asymptomatic VFs in postmenopausal women. Copyright © 2012 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Vitamin D and Calcium Intakes, Physical Activity, and Calcaneus BMC among School-Going 13-Year Old Malaysian Adolescents.

PubMed

Suriawati, A A; Majid, Hazreen Abdul; Al-Sadat, Nabilla; Mohamed, Mohd Nahar Azmi; Jalaludin, Muhammad Yazid

2016-10-24

Dietary calcium and vitamin D are essential for bone development. Apart from diet, physical activity may potentially improve and sustain bone health. To investigate the relationship between the dietary intake of calcium and vitamin D, physical activity, and bone mineral content (BMC) in 13-year-old Malaysian adolescents. Cross-sectional. Selected public secondary schools from the central and northern regions of Peninsular Malaysia. The subjects were from the Malaysian Health and Adolescents Longitudinal Research Team Cohort study (MyHeARTs). The data included seven-day diet histories, anthropometric measurements, and the BMC of calcaneal bone using a portable broadband ultrasound bone densitometer. Nutritionist Pro software was used to calculate the dietary calcium and vitamin D intakes from the diet histories, based on the Nutrient Composition of Malaysian Food Database guidance for the dietary calcium intake and the Singapore Energy and Nutrient Composition of Food Database for vitamin D intake. A total of 289 adolescents (65.7% females) were recruited. The average dietary intakes of calcium and vitamin D were 377 ± 12 mg/day and 2.51 ± 0.12 µg/day, respectively, with the majority of subjects failing to meet the Recommended Nutrient Intake (RNI) of Malaysia for dietary calcium and vitamin D. All the subjects had a normal Z-score for the BMC (-2.00 or higher) with a mean of 0.55 ± 0.01. From the statistical analysis of the factors contributing to BMC, it was found that for those subjects with a higher intake of vitamin D, a higher combination of the intake of vitamin D and calcium resulted in significantly higher BMC quartiles. The regression analysis showed that the BMC might have been influenced by the vitamin D intake. A combination of the intake of vitamin D and calcium is positively associated with the BMC.

Organization and results of student pharmacist bone mineral density screenings in women.

PubMed

Harris, Adam C; Doucette, William R; Reist, Jeffery C; Nelson, Kathryn E

2011-01-01

To describe the organization and results of student pharmacist-run screenings of bone mineral density (BMD) among women living in the community. Iowa City from March 2008 to April 2009. Student pharmacists operated a BMD screening service at several community-based screening events, including university-sponsored health fairs and community pharmacy events. Interested individuals were invited to have their BMD screened; however, only women aged 21 years or older were asked to participate in the data collection. A risk factor form was completed by consenting participants before BMD screening using a quantitative ultrasound densitometer. Upon screening completion, T- and Z-scores were recorded and participants were counseled on their results. Student pharmacists worked to increase public awareness of bone health through the organization of BMD screenings. Working with faculty, a training process and screening-flow outline were developed to allow students to conduct the BMD screenings independently while adding to their education and increasing public health awareness in a community setting. T- and Z-scores from BMD screenings. Eight student pharmacist-organized BMD screenings were conducted during the course of 14 months. A total of 322 women participated in the screenings and data collection. The mean (±SD) T- and Z-scores for these participants were 0.03 ± 1.30 and 0.52 ± 1.13, respectively. A total of 62 (19.4%) women screened had an increased risk of fracture based on a T-score of -1 or less, whereas approximately two-thirds of all women had better-than-average BMD. Student pharmacists provided the community with free screenings that brought BMD scores to the attention of hundreds of women. Counseling sessions that accompanied the screenings contributed to the women learning more about their risks for osteoporosis. Based on these student pharmacist-run BMD screenings, we encourage other student pharmacist organizations to conduct similar screenings.

Evaluation of the radiopacity of calcium silicate cements containing different radiopacifiers.

PubMed

Camilleri, J; Gandolfi, M G

2010-01-01

To identify the suitable ratio of alternative radiopacifiers to impart the necessary radiopacity to calcium silicate cements (CSC) and assess the purity of the radiopacifying agents. Alternative radiopacifying materials for incorporation into CSC included barium sulphate, titanium oxide, zinc oxide, gold powder and silver/tin alloy. The chemical composition of the alternative radipacifying materials and bismuth oxide, which is used in mineral trioxide aggregate (MTA), was determined using energy dispersive X-ray analysis. In addition, using an aluminium step-wedge and densitometer, the radiopacity of each material was evaluated as recommended by international standards. The optical density was compared with the relevant thickness of aluminium (Al). A commercial MTA and CSC were used as controls. Statistical analysis comparing the radiodensity of the different cements to MTA was performed using anova with P = 0.05 and post hoc Tukey test. All percentage replacements of bismuth oxide, gold and silver-tin alloy powder, and the 25% and 30% replacements with barium sulphate and zinc oxide had radiopacities greater than 3 mm thickness of aluminium (Al) recommended by ISO 6876 (2002). The 25% replacement of cement with gold powder and 20% replacement of cement with silver/tin alloy powder exhibited radiopacity values of 8.04 mm Al and 7.52 mm Al, respectively, similar to MTA (P > 0.05). The cement replaced with 20% bismuth oxide showed a radiopacity of 6.83 mm Al, lower than MTA (P = 0.003). Silver/tin alloy and gold powder imparted the necessary radiopacity to a calcium silicate-based cement. Barium sulphate was also a suitable radiopacifier together with a lower concentration of silver/tin alloy and gold powder that achieved the radiodensity recommended by ISO 6876. Further research is required to investigate the broader properties of the calcium silicate-based cement with the different radiopacifiers.

SU-F-T-550: Radiochromic Plastic Thin Sheet Dosimeter: Initial Performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jordan, K; Adamovics, J

Purpose: Thin sheets, of a high sensitivity formulation of radiochromic dosimeter, Presage were prepared and evaluated for optical readout. Methods: Sheets of radiochromic polyurethane, 12 cm long, 10 cm wide and 0.2 cm thick were prepared with leuco crystal violet as the reporter molecule. Sample transmission was evaluated at a wavelength of 590 nm with in-house constructed instruments: optical cone beam laser CT scanner, fixed and scanning spot densitometers. Sample sequential irradiations to a total dose of 40 Gy were conducted with a modified, Theratron 60, cobalt radiotherapy machine at dose rates of 1 or 0.25 Gy per minute. Exposuremore » to ambient and readout light was minimized to limit background photochromic signals. Samples were stored at 4°C. Optical activity was assessed from linearly polarized transmission images. Comparison sensitivity measurements with EBT3 film were conducted. Results: Samples were transparent, smooth and pale purple before irradiation. Radiochromic reaction was completed in less than 5 minutes. A linear dose response with a sensitivity of 0.5 cm-1Gy-1 was observed. Micrometer measurements found sheet thickness variations up to 20%. Uniform dose, 2 Gy attenuation images, correlated with local sheet thicknesses. Comparable measurements with EBT3 film were 3 times more sensitive at 1 Gy but above 15 Gy, EBT3 film had lower sensitivity than 0.2 cm thick Presage sheet dosimeter due to its non-linear response. Conclusion: Dose sensitivity provided a 10% decrease in transmission for a 1 Gy dose. Improvements in mold design are expected to allow production of sheets with less than 5% variation in thickness. Above, 10 Gy, Presage sheet dosimeter performance expected to exceed EBT3 film based on linearity, sensitivity, transparency and smoothness of samples. J Adamovics is owner of Heuris Inc.« less

MUPUS --- a Suite of Small Instruments for the ROSETTA Surface Science Package to Measure the Thermal and Mechanical Properties of a Comet Nucleus

NASA Astrophysics Data System (ADS)

Spohn, T.; MUPUS Team

1996-09-01

The Surface Science Package, which will be deployed in course of the ROSETTA mission on the surface of the target comet, offers the unprecedented opportunity to study the physical properties and dominating processes of a comet nucleus in situ. While most SSP experiments focuse on composition and chemistry, the MUPUS instrument package is aimed to study the energy balance of the nucleus/coma interface and the evolution of key thermal and mechanical parameters. Unlike planetary evolution, cometary evolution is influenced by the energy input at the surface. The near surface layers are accessible with some effort and may thus be directly studied. A penetrator equipped with temperature sensors and heaters (MUPUS--PEN) aims to measure the vertical temperature distribution (PEN--TP) and the thermal conductivity (PEN--THC) in the first tens of centimeters of the nucleus as they evolve with time. A combined evaluation of the PEN--TP and PEN--THC data will allow to understand vertical surface heat flow into or from the comet nucleus and the energy balance of the comet. The surface temperature will be measured with an infrared thermal mapper (MUPUS TM). Both thermal sensors will provide a ground truth for IR data from the orbiter. The PEN--M sensor will measure mechanical properties like hardness and grain size during penetration. A compton backscatter densitometer (CBD) will be used to measure the density. Additional temperature sensors and penetrometers in the SSP's anchor(s) will supplement the data and expand the volume probed. The results will help to understand the onset of activity, gas and dust emission, which will be measured by the orbiter. Understanding the dominating processes and their time scales allows to determine the present state of the surface material ("Is the matter found close to the surface pristine?") as well as extrapolation both into the past and the future.

[Evaluation of preexposed step wedges in acceptance tests of film processing in mammography].

PubMed

Blendl, C

2003-03-01

It was tested with 5 different types of mammography films in which manner the values of "Lightspeed" (LS) and "Lightcontrast" (LC), according DIN V 6868-55 will be changed, when preexposed film strips are used, stored at different climates and spaces of time in comparison to strips, which are exposed immediately before processing. It was proved, that the value LS of preexposed film strips in general will be lowered with increasing storage time compared to freshly exposed film strips, when both strips are processed simultaneously. This drift will be enhanced with increasing rel.humidity levels during storage. The value of LC increases in general with longer storage time and higher rel.humidity levels. The tested film types have all individual drifts in LS and LC. The precision of a single measurement using preexposed film strips was established over all different types of films at in about: Delta LS=0.06 and Delta LC (%)=16% [in the borders of 2 sigma (sigma)]. This uncertainty includes solely the precision of sensitometer, densitometer, the method to establish sensitometric values and unavoidable statistical fluctuations. Even when the systematic drift of the used film type is well established, the required precision, restricted to the listed items and prescribed in DIN V 6868-55, table D.1 to determine the values of LS with Delta LS=0.039 and the values of LC with Delta LC=7.2% is overstepped in so far, that it is impossible to draw a precise conclusion from the measured values to the performance of the subsystem film and processing. If any exceeding of the dose in image receptor plane is monitored, there is no tracking possible to a misadjustment of the subsystem film and processing.

Application of the Minkowski-functionals for automated pattern classification of breast parenchyma depicted by digital mammography

NASA Astrophysics Data System (ADS)

Boehm, Holger F.; Fischer, Tanja; Riosk, Dororthea; Britsch, Stefanie; Reiser, Maximilian

2008-03-01

With an estimated life-time-risk of about 10%, breast cancer is the most common cancer among women in western societies. Extensive mammography-screening programs have been implemented for diagnosis of the disease at an early stage. Several algorithms for computer-aided detection (CAD) have been proposed to help radiologists manage the increasing number of mammographic image-data and identify new cases of cancer. However, a major issue with most CAD-solutions is the fact that performance strongly depends on the structure and density of the breast tissue. Prior information about the global tissue quality in a patient would be helpful for selecting the most effective CAD-approach in order to increase the sensitivity of lesion-detection. In our study, we propose an automated method for textural evaluation of digital mammograms using the Minkowski Functionals in 2D. 80 mammograms are consensus-classified by two experienced readers as fibrosis, involution/atrophy, or normal. For each case, the topology of graylevel distribution is evaluated within a retromamillary image-section of 512 x 512 pixels. In addition, we obtain parameters from the graylevel-histogram (20th percentile, median and mean graylevel intensity). As a result, correct classification of the mammograms based on the densitometic parameters is achieved in between 38 and 48%, whereas topological analysis increases the rate to 83%. The findings demonstrate the effectiveness of the proposed algorithm. Compared to features obtained from graylevel histograms and comparable studies, we draw the conclusion that the presented method performs equally good or better. Our future work will be focused on the characterization of the mammographic tissue according to the Breast Imaging Reporting and Data System (BI-RADS). Moreover, other databases will be tested for an in-depth evaluation of the efficiency of our proposal.

Rib fractures in chronic alcoholic men: Relationship with feeding habits, social problems, malnutrition, bone alterations, and liver dysfunction.

PubMed

González-Reimers, Emilio; García-Valdecasas-Campelo, Elena; Santolaria-Fernández, Francisco; Milena-Abril, Antonio; Rodríguez-Rodríguez, Eva; Martínez-Riera, Antonio; Pérez-Ramírez, Alina; Alemán-Valls, María Remedios

2005-10-01

Rib fractures are common in alcoholics. This high prevalence might be due to ethanol-associated malnutrition, bone disease, liver dysfunction, or the peculiar lifestyle of the alcoholic with frequent trauma and altercations. In this study we try to discern the role of these factors on rib fracture (assessed on a plain thoracic X-ray film) in 81 consecutive alcoholic patients, 25 of them cirrhotics. Serum albumin, prothrombin aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), gamma-glutamyl transpeptidase, C-terminal cross-linking telopeptide of type 1 collagen, osteocalcin, insulin growth factor 1, 1,25-dihydroxyvitamin D, parathyroid hormone, estradiol, free testosterone, and corticosterone were measured, and the patients also underwent assessment of bone mineral density by a HOLOGIC QDR-2000 bone densitometer (Waltham, MA, USA). Body mass index, triceps skinfold, and brachial perimeter were also determined, and the patients and their families were asked about tobacco consumption, social and familial links, consumption of ethanol by other members of the family, kind of job, and feeding habits. Forty-two male nondrinker sanitary workers of similar age served as controls. Forty of the 81 patients showed rib fractures. There was a statistically significant association between rib fractures and disruption of social and familial links, irregular feeding habits (in bars or pubs, not at home), ethanol consumption by close relatives, and intensity of tobacco consumption, but not between rib fractures and liver function tests, nutritional parameters, or bone mineral density, besides a nearly significant trend (p = .053) with the presence of osteopenia at the femoral neck. Patients with major withdrawal symptoms at admission also presented more frequent rib fractures. We conclude that rib fractures in alcoholics are related to the peculiar lifestyle of these patients rather than to bone alterations, liver dysfunction, or nutritional status.

Identification of vertebral deformities in the Polish population by morphometric X-ray absorptiometry - results of the EPOLOS study.

PubMed

Skowrońska-Jóźwiak, Elzbieta; Płudowski, Paweł; Karczmarewicz, Elzbieta; Lorenc, Roman; Lewiński, Andrzej

2009-01-01

The aim of the study was the determination of the prevalence of asymptomatic vertebral deformities in healthy persons of the Polish population, based on morphometric X-ray absorptiometry (MXA), and comparison of the results with data from literature, obtained by other techniques. The study involved 829 persons, including 520 women and 309 men, aged 18-79 years, untreated for osteoporosis before. The Th(4) to L(4) vertebrae were examined. Lateral scans of the thoracic-lumbar spine were made by an Expert-XL densitometer. Six point digitization was used to calculate the anterior (Ha), central (Hc), and posterior (Hp) height of the Th(4)-L(4) vertebral bodies. The vertebrae were defined as having prevalent deformities when at least one ratio value (Ha/Hp, Hc/Hp, Hp/Hp up, or Hp/Hp low) fell 3 SDs below or even more than the reference mean of that ratio at any vertebral level. The analysis was performed on 9629 vertebrae, of which 167 (1.75%), evaluated as deformed and considered as fractures, were observed in 113 patients (13.63 % of the examined patients). In 81 persons (74% of the patients with fractures; 9.7% of the studied population), single fractures were demonstrated, while in 28 persons, multiple deformities prevailed. Fractures occurred in 108 women (20.7% of the examined women) and 42 men (13.5% of the examined men). The highest incidence of deformities was observed in women over 55 years of age. First-degree deformities dominated. Deformities of the Th(8) and Th(6) vertebrae were most frequently observed. 1. Using MXA, it was found that in the Polish population deformities of vertebrae are common, as was demonstrated in X-ray morphometric studies in the European Vertebral Observation Study (EVOS). 2. Densitometric morphometry, as a non-invasive technique, may become a useful tool in the diagnostics of vertebral fractures.

Age-related proximal femur bone mineral loss in South Indian women: a dual energy X-ray absorptiometry study.

PubMed

Anburajan, M; Rethinasabapathi, C; Korath, M P; Ponnappa, B G; Kumar, K S; Panicker, T M; Govindan, A; Jagadeesan, G N

2001-04-01

i) To collect normative data for proximal femur bone mineral density (BMD) in South Indian women using dual energy X-ray absorptiometry (DXA) and ii) to study the rate and significance of hip bone mineral loss with advancing age in this population. Forty five women, whose age ranged from 16 to 84 years were studied. This sample was drawn randomly from general medical practice at KJ Hospital, Chennai, South India during November, 1997 to April, 1998. Of these 45 cases, 21 were pre-menopausal (mean +/- SD age = 30.9+/-8.8 years) and 24 post-menopausal (mean +/- SD age = 62.1+/-11.0 years). Subjects with secondary bone diseases were excluded. Also excluded were those taking any drugs known to affect calcium metabolism e.g., thiazide diuretics, oestrogen and calcium. Subjects were divided into seven decadal age groups from 15-24 years to 75-84 years. BMD of the right proximal femur was evaluated using a QDR-1000 DXA bone densitometer (Hologic Inc., Waltham, Massachusetts, USA). Data analysis was done with SPSS/PC statistical software package. Linear regression analysis showed significant (p < 0.001) negative correlations between all hip BMD variables at different regions of interest and patient's age. Relative to that at 30 years of age, rates of BMD loss in the neck of femur, trochanter, intertrochanter, total hip and Ward's triangle were 0.68%, 0.65%, 0.58%, 0.61% and 1.05% per annum respectively. Over the age of 65 years, the above mentioned regions BMD decreased by 0.91%, 0.84%, 0.72%, 0.78% and 1.66% per annum respectively. Normative data for proximal femur BMD in South India women have been evaluated and it may prove useful for diagnosing osteoporosis in the women of South India.

Nuclear DNA amounts in angiosperms: progress, problems and prospects.

PubMed

Bennett, M D; Leitch, I J

2005-01-01

The nuclear DNA amount in an unreplicated haploid chromosome complement (1C-value) is a key diversity character with many uses. Angiosperm C-values have been listed for reference purposes since 1976, and pooled in an electronic database since 1997 (http://www.kew.org/cval/homepage). Such lists are cited frequently and provide data for many comparative studies. The last compilation was published in 2000, so a further supplementary list is timely to monitor progress against targets set at the first plant genome size workshop in 1997 and to facilitate new goal setting. The present work lists DNA C-values for 804 species including first values for 628 species from 88 original sources, not included in any previous compilation, plus additional values for 176 species included in a previous compilation. 1998-2002 saw striking progress in our knowledge of angiosperm C-values. At least 1700 first values for species were measured (the most in any five-year period) and familial representation rose from 30 % to 50 %. The loss of many densitometers used to measure DNA C-values proved less serious than feared, owing to the development of relatively inexpensive flow cytometers and computer-based image analysis systems. New uses of the term genome (e.g. in 'complete' genome sequencing) can cause confusion. The Arabidopsis Genome Initiative C-value for Arabidopsis thaliana (125 Mb) was a gross underestimate, and an exact C-value based on genome sequencing alone is unlikely to be obtained soon for any angiosperm. Lack of this expected benchmark poses a quandary as to what to use as the basal calibration standard for angiosperms. The next decade offers exciting prospects for angiosperm genome size research. The database (http://www.kew.org/cval/homepage) should become sufficiently representative of the global flora to answer most questions without needing new estimations. DNA amount variation will remain a key interest as an integrated strand of holistic genomics.

Bioimpedence to Assess Breast Density as a Risk Factor for Breast Cancer in Adult Women and Adolescent Girls.

PubMed

Maskarinec, Gertraud; Morimoto, Yukiko; Laguana, Michelle B; Novotny, Rachel; Leon Guerrero, Rachael T

2016-01-01

Although high mammographic density is one of the strongest predictors of breast cancer risk, X-ray based mammography cannot be performed before the recommended screening age, especially not in adolescents and young women. Therefore, new techniques for breast density measurement are of interest. In this pilot study in Guam and Hawaii, we evaluated a radiation-free, bioimpedance device called Electrical Breast DensitometerTM (EBD; senoSENSE Medical Systems, Inc., Ontario, Canada) for measuring breast density in 95 women aged 31-82 years and 41 girls aged 8-18 years. Percent density (PD) was estimated in the women's most recent mammogram using a computer-assisted method. Correlation coefficients and linear regression were applied for statistical analysis. In adult women, mean EBD and PD values of the left and right breasts were 230±52 and 226±50 Ω and 23.7±15.1 and 24.2±15.2%, respectively. The EBD measurements were inversely correlated with PD (rSpearman=-0.52, p<0.0001); the correlation was stronger in Caucasians (rSpearman=-0.70, p<0.0001) than Asians (rSpearman=-0.54, p<0.01) and Native Hawaiian/Chamorro/Pacific Islanders (rSpearman=-0.34, p=0.06). Using 4 categories of PD (<10, 10-25, 26-50, 51-75%), the respective mean EBD values were 256±32, 249±41, 202±46, and 178±43 Ω (p<0.0001). In girls, the mean EBD values in the left and right breast were 148±40 and 155±54 Ω; EBD values decreased from Tanner stages 1 to 4 (204±14, 154±79, 136±43, and 119±16 Ω for stages 1-4, respectively) but were higher at Tanner stage 5 (165±30 Ω). With further development, this bioimpedance method may allow for investigations of breast development among adolescent, as well as assessment of breast cancer risk early in life and in populations without access to mammography.

RIKEN Integrated Sequence Analysis (RISA) System—384-Format Sequencing Pipeline with 384 Multicapillary Sequencer

PubMed Central

Shibata, Kazuhiro; Itoh, Masayoshi; Aizawa, Katsunori; Nagaoka, Sumiharu; Sasaki, Nobuya; Carninci, Piero; Konno, Hideaki; Akiyama, Junichi; Nishi, Katsuo; Kitsunai, Tokuji; Tashiro, Hideo; Itoh, Mari; Sumi, Noriko; Ishii, Yoshiyuki; Nakamura, Shin; Hazama, Makoto; Nishine, Tsutomu; Harada, Akira; Yamamoto, Rintaro; Matsumoto, Hiroyuki; Sakaguchi, Sumito; Ikegami, Takashi; Kashiwagi, Katsuya; Fujiwake, Syuji; Inoue, Kouji; Togawa, Yoshiyuki; Izawa, Masaki; Ohara, Eiji; Watahiki, Masanori; Yoneda, Yuko; Ishikawa, Tomokazu; Ozawa, Kaori; Tanaka, Takumi; Matsuura, Shuji; Kawai, Jun; Okazaki, Yasushi; Muramatsu, Masami; Inoue, Yorinao; Kira, Akira; Hayashizaki, Yoshihide

2000-01-01

The RIKEN high-throughput 384-format sequencing pipeline (RISA system) including a 384-multicapillary sequencer (the so-called RISA sequencer) was developed for the RIKEN mouse encyclopedia project. The RISA system consists of colony picking, template preparation, sequencing reaction, and the sequencing process. A novel high-throughput 384-format capillary sequencer system (RISA sequencer system) was developed for the sequencing process. This system consists of a 384-multicapillary auto sequencer (RISA sequencer), a 384-multicapillary array assembler (CAS), and a 384-multicapillary casting device. The RISA sequencer can simultaneously analyze 384 independent sequencing products. The optical system is a scanning system chosen after careful comparison with an image detection system for the simultaneous detection of the 384-capillary array. This scanning system can be used with any fluorescent-labeled sequencing reaction (chain termination reaction), including transcriptional sequencing based on RNA polymerase, which was originally developed by us, and cycle sequencing based on thermostable DNA polymerase. For long-read sequencing, 380 out of 384 sequences (99.2%) were successfully analyzed and the average read length, with more than 99% accuracy, was 654.4 bp. A single RISA sequencer can analyze 216 kb with >99% accuracy in 2.7 h (90 kb/h). For short-read sequencing to cluster the 3′ end and 5′ end sequencing by reading 350 bp, 384 samples can be analyzed in 1.5 h. We have also developed a RISA inoculator, RISA filtrator and densitometer, RISA plasmid preparator which can handle throughput of 40,000 samples in 17.5 h, and a high-throughput RISA thermal cycler which has four 384-well sites. The combination of these technologies allowed us to construct the RISA system consisting of 16 RISA sequencers, which can process 50,000 DNA samples per day. One haploid genome shotgun sequence of a higher organism, such as human, mouse, rat, domestic animals, and plants, can

New approach to probability estimate of femoral neck fracture by fall (Slovak regression model).

PubMed

Wendlova, J

2009-01-01

3,216 Slovak women with primary or secondary osteoporosis or osteopenia, aged 20-89 years, were examined with the bone densitometer DXA (dual energy X-ray absorptiometry, GE, Prodigy - Primo), x = 58.9, 95% C.I. (58.42; 59.38). The values of the following variables for each patient were measured: FSI (femur strength index), T-score total hip left, alpha angle - left, theta angle - left, HAL (hip axis length) left, BMI (body mass index) was calculated from the height and weight of the patients. Regression model determined the following order of independent variables according to the intensity of their influence upon the occurrence of values of dependent FSI variable: 1. BMI, 2. theta angle, 3. T-score total hip, 4. alpha angle, 5. HAL. The regression model equation, calculated from the variables monitored in the study, enables a doctor in praxis to determine the probability magnitude (absolute risk) for the occurrence of pathological value of FSI (FSI < 1) in the femoral neck area, i. e., allows for probability estimate of a femoral neck fracture by fall for Slovak women. 1. The Slovak regression model differs from regression models, published until now, in chosen independent variables and a dependent variable, belonging to biomechanical variables, characterising the bone quality. 2. The Slovak regression model excludes the inaccuracies of other models, which are not able to define precisely the current and past clinical condition of tested patients (e.g., to define the length and dose of exposure to risk factors). 3. The Slovak regression model opens the way to a new method of estimating the probability (absolute risk) or the odds for a femoral neck fracture by fall, based upon the bone quality determination. 4. It is assumed that the development will proceed by improving the methods enabling to measure the bone quality, determining the probability of fracture by fall (Tab. 6, Fig. 3, Ref. 22). Full Text (Free, PDF) www.bmj.sk.

Reliability of a two-wavelength autofluorescence technique by Heidelberg Spectralis to measure macular pigment optical density in Asian subjects.

PubMed

Obana, Akira; Gellermann, Werner; Gohto, Yuko; Seto, Takahiko; Sasano, Hiroyuki; Tanito, Masaki; Okazaki, Shigetoshi

2018-03-01

This study evaluates the accuracy of an objective two-wavelength fundus autofluorescence technique for the purpose of measuring the macular pigment optical density (MPOD) in Asian pigmented eyes. Potential differences between MPOD values obtained via autofluorescence technique and subjective heterochromatic photometry (HFP) were examined. Inter-examiner reproducibility between three examiners and test-retest reliability over five time points were also explored. Subjects were 27 healthy Japanese volunteers aged 24 to 58 (mean ± standard deviation, 40.2 ± 9.0) years. An MPOD module of the Spectralis MultiColor instrument configuration (Spectralis-MP) was used for the autofluorescence technique, and a Macular Metrics Densitometer (MM) was used for HFP. The mean MPOD values at 0.25° and 0.5° eccentricities using the Spectralis-MP were 0.51 ± 0.12 and 0.48 ± 0.13, respectively. In comparison, the MM based values were 0.72 ± 0.23 and 0.61 ± 0.25, respectively. High correlations between the Spectralis-MP and MM instrument were found (Pearson's correlation coefficients of 0.73 and 0.87 at 0.25° and 0.5° eccentricities, respectively), but there was a systematic bias: the MPOD values by MM method were significantly higher than those by Spectralis-MP at 0.25° eccentricity. High inter-examiner reproducibility and test-retest reliability were found for MM measurements at 0.5° eccentricity, but not at 0.25°. The Spectralis-MP showed less inter-examiner and test-retest variability than the MM instrument at 0.25° and 0.5° eccentricities. We conclude that the Spectralis-MP, given its high agreement with the HFP method and due to its higher reproducibility and reliability, is well suited for clinical measurements of MPOD levels in Asian pigmented eyes. Copyright © 2018. Published by Elsevier Ltd.

Vitamin D and Calcium Intakes, Physical Activity, and Calcaneus BMC among School-Going 13-Year Old Malaysian Adolescents

PubMed Central

Suriawati, A. A.; Abdul Majid, Hazreen; Al-Sadat, Nabilla; Mohamed, Mohd Nahar Azmi; Jalaludin, Muhammad Yazid

2016-01-01

Background: Dietary calcium and vitamin D are essential for bone development. Apart from diet, physical activity may potentially improve and sustain bone health. Objective: To investigate the relationship between the dietary intake of calcium and vitamin D, physical activity, and bone mineral content (BMC) in 13-year-old Malaysian adolescents. Design: Cross-sectional. Setting: Selected public secondary schools from the central and northern regions of Peninsular Malaysia. Participants: The subjects were from the Malaysian Health and Adolescents Longitudinal Research Team Cohort study (MyHeARTs). Methods: The data included seven-day diet histories, anthropometric measurements, and the BMC of calcaneal bone using a portable broadband ultrasound bone densitometer. Nutritionist Pro software was used to calculate the dietary calcium and vitamin D intakes from the diet histories, based on the Nutrient Composition of Malaysian Food Database guidance for the dietary calcium intake and the Singapore Energy and Nutrient Composition of Food Database for vitamin D intake. Results: A total of 289 adolescents (65.7% females) were recruited. The average dietary intakes of calcium and vitamin D were 377 ± 12 mg/day and 2.51 ± 0.12 µg/day, respectively, with the majority of subjects failing to meet the Recommended Nutrient Intake (RNI) of Malaysia for dietary calcium and vitamin D. All the subjects had a normal Z-score for the BMC (−2.00 or higher) with a mean of 0.55 ± 0.01. From the statistical analysis of the factors contributing to BMC, it was found that for those subjects with a higher intake of vitamin D, a higher combination of the intake of vitamin D and calcium resulted in significantly higher BMC quartiles. The regression analysis showed that the BMC might have been influenced by the vitamin D intake. Conclusions: A combination of the intake of vitamin D and calcium is positively associated with the BMC. PMID:27783041

Influence of obesity on vertebral fracture prevalence and vitamin D status in postmenopausal women.

PubMed

El Maghraoui, A; Sadni, S; El Maataoui, A; Majjad, A; Rezqi, A; Ouzzif, Z; Mounach, A

2015-01-01

It is well established that weight is an important determinant of bone health. Whereas obesity is associated with increased mortality and morbidity from diabetes and cardiovascular diseases, high body weight is widely believed to be associated to hypovitaminosis D and protective against the development of osteoporosis and fracture risk. The objective of the study was to evaluate the effect of BMI on vitamin D status and on densitometric vertebral fractures (VFs) in a large series of asymptomatic women aged over 50 who had a VFA examination during their bone mineral density (BMD) testing. We enrolled 429 postmenopausal women (mean age, weight and BMI of 59.5 ± 8.3 (50 to 83) years, 75.8 ± 13.3 (35 to 165) kgs and 29.9 ± 5.2 (14.6 to 50.8) kg/m(2), respectively. Lateral VFA images and scans of the lumbar spine and proximal femur were obtained using a Lunar Prodigy densitometer. VFs were defined using the Genant semiquantitative (SQ) approach. Clinical risk factors of osteoporosis were collected and 25-hydroxivitamin D was measured using electrochimiluminescence (Roche). Prevalence of osteoporosis and hypovitaminosis D (<20 ng/ml) was 21.0 % and 78.1 % respectively. VFs grade 2/3were identified in 76 (17.7 %). Comparison between women according to their BMI showed that obese women had a higher BMD and less proportion of women with osteoporosis and VFs grade 2/3 than lean and overweight women. The prevalence of VFs globally increased with age and as BMI and BMD declined. Stepwise regression analysis showed that the presence of osteoporosis was independently related to BMI and history of fractures while the presence of grade 2/3 VFs was independently related to age, hypovitaminosis D and years of menopause. Obese women had a higher BMD and lower prevalence of VFs. VFs were significantly related to age, hypovitaminosis D and years since menopause. However, among obese women, prevalence of VFs was increased in osteoporotic women.

Use of quantitative ultrasonography in differentiating osteomalacia from osteoporosis: preliminary study.

PubMed

Luisetto, G; Camozzi, V; De Terlizzi, F

2000-04-01

The aim of this work was to use ultrasonographic technology to differentiate osteoporosis from osteomalacia on the basis of different patterns of the graphic trace. Three patients with osteomalacia and three with osteoporosis, all with the same lumbar spine bone mineral density, were studied. The velocity of the ultrasound beam in bone was measured by a DBM Sonic 1,200/I densitometer at the proximal phalanges of the hands in all the patients. The ultrasound beam velocity was measured when the first peak of the waveform reached a predetermined minimum amplitude value (amplitude-dependent speed of sound) as well as at the lowest point prior to the first and second peaks, before they reached the predetermined minimum amplitude value (first and second minimum speeds of sound). The graphic traces were further analyzed by Fourier analysis, and both the main frequency (f0) and the width of the peak centered in the f0 (full width at half maximum) were measured. The first and second minimum speeds of sound were significantly lower in the patients with osteomalacia than in the osteoporosis group. The first minimum speed of sound was 2,169 +/- 73 m/s in osteoporosis and 1,983 +/- 61 m/s in osteomalacia (P < 0.0001); the second minimum peak speed of sound was 1,895 +/-59 m/s in osteoporosis and 1,748 +/- 38 m/s in osteomalacia (P < 0.0001). The f0 was similar in the two groups (osteoporosis, 0.85 +/- 0.14 MHz; osteomalacia, 0.9 +/- 0.22 MHz; P = 0.72), and the full width at half maximum was significantly higher in the osteomalacia patients (0.52 +/- 0.14 MHz) than in the osteoporosis patients (0.37 +/- 0.15 MHz) (P = 0.022). This study confirms that ultrasonography is a promising, noninvasive method that could be used to differentiate osteoporosis from osteomalacia, but further studies should be carried out before this method can be introduced into clinical practice.

The relationship between social deprivation, osteoporosis, and falls.

PubMed

Pearson, Derek; Taylor, Rachel; Masud, Tahir

2004-02-01

The aim of this study was to assess the relationship between heel BMD, risk factors for osteoporosis, falls history, and the Jarman Underprivileged Area Score in an older community population. From the general practice register, 1,187 women (mean age 70, range 60 to 94) were recruited. BMD of the heel was measured using the GE Lunar PIXI densitometer. A T-score cutoff for predicted osteoporosis at the spine or hip of -1.7 was used. A risk factor questionnaire was completed that included fracture history and falls history. The odds ratio (OR) with a 95% confidence interval (CI) was calculated for each risk factor for each quartile of Jarman score and for the diagnosis of osteoporosis. Logistic regression was used to identify the risk factors that predict lone bone mass in the heel. There were no significant differences between women in different quartiles of Jarman score in terms of age and body mass index (BMI). Women in the highest two quartiles of Jarman score (i.e., most deprived) had a significantly higher likelihood of osteoporosis (OR=1.82; 95% CI, 1.03 to 1.63; and OR=1.85; 95% CI, 1.04 to 1.64, respectively) and significantly lower BMD ( p=0.008). Women in these two quartiles were significantly more likely to have had a history of previous fracture (OR=1.66; 95% CI, 1.01 to 1.53), but there was no difference in falls history. Women in the lowest quartile (least deprived) were also significantly less likely to smoke ( p=0.011) but were not significantly different in terms of other risk factors (e.g., dietary calcium and activity). BMI, age, kyphosis, significant visual problems, and quartile of Jarman score were significant risk factors for low bone mass. Risk factors identified those with low bone mass at the heel with a sensitivity and specificity of 72%. In conclusion, women in the lowest quartile of Jarman score (i.e., least deprived) have significantly higher heel BMD compared with the rest of the population.

Vitamin D and nutritional status are related to bone fractures in alcoholics.

PubMed

González-Reimers, Emilio; Alvisa-Negrín, Julio; Santolaria-Fernández, Francisco; Candelaria Martín-González, M; Hernández-Betancor, Iván; Fernández-Rodríguez, Camino M; Viña-Rodríguez, J; González-Díaz, Antonieta

2011-01-01

Bone fractures are common in alcoholics. To analyse which factors (ethanol consumption; liver function impairment; bone densitometry; hormone changes; nutritional status, and disrupted social links and altered eating habits) are related to bone fractures in 90 alcoholic men admitted to our hospitalization unit because of organic problems. Bone homoeostasis-related hormones were measured in patients and age- and sex-matched controls. Whole-body densitometry was performed by a Hologic QDR-2000 (Waltham, MA, USA) densitometer, recording bone mineral density (BMD) and fat and lean mass; nutritional status and liver function were assessed. The presence of prevalent fractures was assessed by anamnesis and chest X-ray film. Forty-nine patients presented at least one fracture. We failed to find differences between patients with and without fractures regarding BMD parameters. Differences regarding fat mass were absent, but lean mass was lower among patients with bone fracture. The presence of fracture was significantly associated with impaired subjective nutritional evaluation (χ² = 5.79, P = 0.016), lower vitamin D levels (Z = 2.98, P = 0.003) and irregular eating habits (χ² = 5.32, P = 0.02). Reduced lean mass and fat mass, and altered eating habits were more prevalent among patients with only rib fractures (n = 36) than in patients with multiple fractures and/or fractures affecting other bones (n = 13). These last were more closely related to decompensated liver disease. Serum vitamin D levels showed a significant relationship with handgrip strength (ρ = 0.26, P = 0.023) and lean mass at different parts of the body, but not with fat mass. By logistic regression analysis, only vitamin D and subjective nutritional evaluation were significantly, independently related with fractures. Prevalent fractures are common among heavy alcoholics. Their presence is related more closely to nutritional status, lean mass and vitamin D levels than to BMD. Lean mass is more reduced

Bone loss from the hand in women following distal forearm fracture.

PubMed

Ingle, B M; Eastell, R

2001-01-01

Bone loss occurs after distal forearm fracture, but it is unclear if this bone loss is fully recovered. We designed a cross-sectional study to evaluate the time course of the bone loss from the hand after distal forearm fracture. We identified 40 women who had a fracture of the distal forearm within the previous 4.5 years. Their ages ranged from 42 to 81 (mean 64 years) and time since fracture 6 to 54 (mean 28 months). These were compared with 95 women (mean age 67, range 57 to 80 years) from a population-based cohort. Lumbar spine (LS) and hand bone mineral density (BMD) were measured in all subjects using a Hologic QDR 1000/W densitometer. Ultrasound of the fingers of both hands was measured in the forearm fracture group using a DBM Sonic 1200 R model. Compared to controls, LS BMD was decreased by 6.4% (p<0.001), non-fractured hand by 3.2% (p<0.001) and the fractured hand by 6.1% (p<0.001) in the forearm fracture group. The mean difference in bone density between the fractured and non-fractured hand was 0.0207 g/cm2, the average value for the non-fractured hand being 0.304 g/cm2. The decement in hand BMD was equivalent to 6.2% (p<0.0001). The difference in hand BMD between the fractured and non-fractured side was greatest when the time since fracture was short; there was no further difference in hand BMD after 2 years. Ultrasound showed a mean difference of 18.7 m/s in amplitude-dependent speed of sound (AD-SoS) with the average value being 1893 m/s. A 1.0% decrease was observed in the fractured hand AD-SoS (p<0.05). A strong relationship was observed between AD-SoS and BMD in both hands (r = 0.70, p<0.001). We conclude that distal forearm fracture results in a significant decrease in hand BMD that is partially reversible. The decrease in hand BMD is reflected in the ultrasound properties of the finger phalanx.

Photographic Method For Measurement Of Image Intensifier Tube Contrast

NASA Astrophysics Data System (ADS)

Moore, Robert J.

1981-07-01

An important parameter in an image intensifier-based imaging system is the contrast of the image intensifier tube itself. This paper presents a photographic method for the measurement of the large-scale contrast of an image intensifier tube at the system level which can be performed in the clinical setting with equipment normally found in a modern Radiology Department. A strip of Lead is positioned on-center at the bottom of the grid so that a line image of 100% contrast will be presented to the input phosphor of the image intensifier when the x-ray tube is energized at low kilovoltage. The output phosphor is photographed either with an existing fluorographic camera (photospot or cine) on the imaging tower, or with a 35-mm SLR camera loaded with orthochromatic cine film through the collimating lens of the system from the position normally occupied by the television camera, during fluoroscopy, if no other camera is present on the imaging tower. The resultant on-frame optical density is measured with a densitometer in the central part of the developed frame adjacent to and behind the image of the Lead strip. These optical density readings are converted into a ratio of light intensities from the corresponding regions on the output phosphor using the characteristic curve for the type of film employed, which is obtained by means of light sensitometry. The percent contrast is then calculated from (ratio of intensities - 1)/(ratio of intensities + 1)) X 100. Using data for a variety of CsI image intensifiers used for both gastrointestinal and vascular studies, the method is shown to give measured percent contrasts with a reproducibility of no worse than-2%, independent of type of camera used or type of sensitometer used. Standards of acceptable performance based on the author's experience with this technique over the past five years are presented for systems designed for Barium studies and for systems designed for Iodine studies. The relationship between the percent

Intra-annual variability of anatomical structure and δ13C values within tree rings of spruce and pine in alpine, temperate and boreal Europe

PubMed Central

Vaganov, Eugene A.; Skomarkova, Marina V.; Knohl, Alexander; Brand, Willi A.; Roscher, Christiane

2009-01-01

Tree-ring width, wood density, anatomical structure and 13C/12C ratios expressed as δ13C-values of whole wood of Picea abies were investigated for trees growing in closed canopy forest stands. Samples were collected from the alpine Renon site in North Italy, the lowland Hainich site in Central Germany and the boreal Flakaliden site in North Sweden. In addition, Pinus cembra was studied at the alpine site and Pinus sylvestris at the boreal site. The density profiles of tree rings were measured using the DENDRO-2003 densitometer, δ13C was measured using high-resolution laser-ablation-combustion-gas chromatography-infra-red mass spectrometry and anatomical characteristics of tree rings (tracheid diameter, cell-wall thickness, cell-wall area and cell-lumen area) were measured using an image analyzer. Based on long-term statistics, climatic variables, such as temperature, precipitation, solar radiation and vapor pressure deficit, explained <20% of the variation in tree-ring width and wood density over consecutive years, while 29–58% of the variation in tree-ring width were explained by autocorrelation between tree rings. An intensive study of tree rings between 1999 and 2003 revealed that tree ring width and δ13C-values of whole wood were significantly correlated with length of the growing season, net radiation and vapor pressure deficit. The δ13C-values were not correlated with precipitation or temperature. A highly significant correlation was also found between δ13C of the early wood of one year and the late wood of the previous year, indicating a carry-over effect of the growing conditions of the previous season on current wood production. This latter effect may explain the high autocorrelation of long-term tree-ring statistics. The pattern, however, was complex, showing stepwise decreases as well as stepwise increases in the δ13C between late wood and early wood. The results are interpreted in the context of the biochemistry of wood formation and its linkage

Habitual tea drinking and bone mineral density in postmenopausal Turkish women: investigation of prevalence of postmenopausal osteoporosis in Turkey (IPPOT Study).

PubMed

Hamdi Kara, Ismail; Aydin, Serpil; Gemalmaz, Ayfer; Aktürk, Zekeriya; Yaman, Hakan; Bozdemir, Nafiz; Kurdak, Hatice; Sitmapinar, Karanfil; Devran Sencar, Ilknur; Başak, Okay; Akdeniz, Melahat; Işildar, Hakan; Burgut, Erhan; Ozcan, Sevgi; Akça, Unal; Dağdeviren, Nezih; Ungan, Mehmet

2007-11-01

In this epidemiological report, we assessed the prevalence of osteopenia and osteoporosis (OP) in postmenopausal Turkish women and the relationship between body mass index (BMI), and some nutritional factors (habitual tea, coffee, tobacco, and milk product consumption) with OP. This multicenter study was done in postmenopausal women residing in five big cities, in four different regions of Turkey between August and November 2005. An inclusion criterion was being in the postmenopausal period for at least 12 months. A semi-structured questionnaire was completed by face-to-face interview, consisting of closed- and open-ended questions about demographic characteristics, nutritional status, and habits with two or more choices as possible responses. Bone mineral density (BMD) measurements were performed with a MetriScan Densitometer (Alara Inc., CA, USA). Seven hundred twenty-four women were included in the study. The mean age was 57.6 +/- 9.6 years, and mean age at natural menopause was 46.4 +/- 5.6 years. Of the participants, 51% were illiterate. According to WHO classification; 42.5% were normal in terms of BMD, 27.2% had osteopenia, and 30.2% had OP. Women with high education levels had better T-scores (p = 0.019). Increase in BMI also had a positive effect on T-scores (p < 0.0001). A linear correlation was found between age (r= -0.386, p < 0.0001), BMI (r = -0.175, p < 0.0001), and education (r = -0.317, p < 0.0001), with T-scores. The T-scores of women who consumed tea on a regular basis were found to be higher than non-consumers (-1.51 +/- 1.68 vs. -1.09 +/- 1.66; p = 0.070) [when smokers, those who received hormonal therapy (HT), and those > 65 years were excluded]. OP was determined in 1/3 of the women. Advanced age (> 65) and being illiterate were negative factors, while high education levels, being overweight, and being treated with HT had a positive effects on BMD. Habitual tea drinking also may have a positive effect on BMD. However, tea drinking was not

Prevalence and related risk factors of osteoporosis in peri- and postmenopausal Indian women.

PubMed

Aggarwal, Neelam; Raveendran, Ainharan; Khandelwal, Niranjan; Sen, Ramesh Kumar; Thakur, J S; Dhaliwal, Lakhbir Kaur; Singla, Veenu; Manoharan, Sakthivel Rajan Rajaram

2011-07-01

We undertook this study involving 200 peri- and postmenopausal women to determine the prevalence of osteoporosis, and in turn increase the awareness, education, prevention, and treatment of osteoporosis. Postgraduate Institute of Medical Education and Research, UT Chandigarh, India, and a clinical study. A detailed medical, obstetrical, menstrual, and drug history was recorded in a proforma designated for the study. Height and weight was measured, weight-bearing exercise was assessed, and sunlight exposure per day for each woman was recorded. Food intake was estimated by using the 24-hour dietary recall method, and calcium and vitamin D consumption pattern was assessed. Bone mineral density (BMD) at postero-anterior lumbar spine and dual femurs was assessed by densitometer. Women were classified according to the WHO criteria. Student's t-test, multiple logistic regression analysis. The prevalence of low BMD was found in more than half of this population (53%). The mean age in group I (normal BMD) was found to be 50.56 ± 5.74 years as compared to 52.50 ± 5.94 in group II with low BMD (P=0.02). The two groups were similar with respect to parity, education, socioeconomic status, family history of osteoporosis, hormone replacement therapy, and thyroid disorders. 46.8% of the women in group I and 33% of the women in group II had low physical activity and there was no statistically significant difference in sunlight exposure between the groups. Parity or the number of children and type of menopause was not seen to have much association with low BMD in our study. Lack of exercise and low calcium diet were significantly associated with low BMD. Multiple logistic regression analysis showed that age, exercise, menopause, and low calcium diet acted as significant predictors of low bone density. The findings from the study suggest the need for large community-based studies so that high-risk population can be picked up and early interventions and other life style changes can

Objective evaluation of slanted edge charts

NASA Astrophysics Data System (ADS)

Hornung, Harvey (.

2015-01-01

Camera objective characterization methodologies are widely used in the digital camera industry. Most objective characterization systems rely on a chart with specific patterns, a software algorithm measures a degradation or difference between the captured image and the chart itself. The Spatial Frequency Response (SFR) method, which is part of the ISO 122331 standard, is now very commonly used in the imaging industry, it is a very convenient way to measure a camera Modulation transfer function (MTF). The SFR algorithm can measure frequencies beyond the Nyquist frequency thanks to super-resolution, so it does provide useful information on aliasing and can provide modulation for frequencies between half Nyquist and Nyquist on all color channels of a color sensor with a Bayer pattern. The measurement process relies on a chart that is simple to manufacture: a straight transition from a bright reflectance to a dark one (black and white for instance), while a sine chart requires handling precisely shades of gray which can also create all sort of issues with printers that rely on half-toning. However, no technology can create a perfect edge, so it is important to assess the quality of the chart and understand how it affects the accuracy of the measurement. In this article, I describe a protocol to characterize the MTF of a slanted edge chart, using a high-resolution flatbed scanner. The main idea is to use the RAW output of the scanner as a high-resolution micro-densitometer, since the signal is linear it is suitable to measure the chart MTF using the SFR algorithm. The scanner needs to be calibrated in sharpness: the scanner MTF is measured with a calibrated sine chart and inverted to compensate for the modulation loss from the scanner. Then the true chart MTF is computed. This article compares measured MTF from commercial charts and charts printed on printers, and also compares how of the contrast of the edge (using different shades of gray) can affect the chart MTF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wainwright, W. W.

It is suggested that film speed is the most important single factor in reducing dental radiation exposure but has been given little attention. A necessary step in this direction is the application of quantitative film rating systems (of the type used in general radiography) to dental radiography and attention to exposure development factors. To this end, a sensitometric method is presented for measurement of undesired dental radiation overexposure resulting from underdevelopment. The method is based on a universal curve of density-log relative exposure for dental x-ray film. The curve is applicable to any given film and machine setting in intraoralmore » roentgenography. Correct exposure time can be predicted from the curve after exposure of only two dental films and use of a lead-aluminum penetrometer. This dental penetrometer and the universal sensitometric curve make it possible to conduct mass surveys of the amount of radiation overexposure from exposure-development factors in dental offices. An example of a typical determination of the effect of exposuredevelopment factors on radiation dose is given. The densities were measured with a densitometer in the range from 0 to 8. With an exposure of 1/2 sec and development for 1 1/2 min at 64 deg F, the hypothetical dentist obtained a density of 1.95 under aluminum. Full development gave a much greater density, 4.05, which was found by reference to the universal curve to represent a radiation exposure of 3.5 times normal. In other words, the underdevelopment (1 1/2 min at 64 deg F) was compensated by overexposure (1/2 sec), so that films of normal density could be obtained. The dentist was informed of the overexposure, and it was predicted that by dividing his time (1/2 sec) by the radiation exposure (3.5), with full development, he would be able to reduce exposure time from 0.5 to 0.143 sec. On the corrected film with an exposure time of 0.15 sec, the density is 1.72. By changing to full development, the dentist

Advanced radiochromic film methodologies for quantitative dosimetry of small and nonstandard fields

NASA Astrophysics Data System (ADS)

Rosen, Benjamin S.

Radiotherapy treatments with small and nonstandard fields are increasing in use as collimation and targeting become more advanced, which spare normal tissues while increasing tumor dose. However, dosimetry of small and nonstandard fields is more difficult than that of conventional fields due to loss of lateral charged-particle equilibrium, tight measurement setup requirements, source occlusion, and the volume-averaging effect of conventional dosimeters. This work aims to create new small and nonstandard field dosimetry protocols using radiochromic film (RCF) in conjunction with novel readout and analysis methodologies. It also is the intent of this work to develop an improved understanding of RCF structure and mechanics for its quantitative use in general applications. Conventional digitization techniques employ white-light, flatbed document scanners or scanning-laser densitometers which are not optimized for RCF dosimetry. A point-by-point precision laser densitometry system (LDS) was developed for this work to overcome the film-scanning artifacts associated with the use of conventional digitizers, such as positional scan dependence, off-axis light scatter, glass bed interference, and low signal-to-noise ratios. The LDS was shown to be optically traceable to national standards and to provide highly reproducible density measurements. Use of the LDS resulted in increased agreement between RCF dose measurements and the single-hit detector model of film response, facilitating traceable RCF calibrations based on calibrated physical quantities. GafchromicRTM EBT3 energy response to a variety of reference x-ray and gamma-ray beam qualities was also investigated. Conventional Monte Carlo methods are not capable of predicting film intrinsic energy response to arbitrary particle spectra. Therefore, a microdosimetric model was developed to simulate the underlying physics of the radiochromic mechanism and was shown to correctly predict the intrinsic response relative to a

Correlations between the MR Diffusion-weighted Image (DWI) and the bone mineral density (BMD) as a function of the soft tissue thickness-focus on phantom and patient

NASA Astrophysics Data System (ADS)

Kim, Myung-Sam; Cho, Jae-Hwan; Lee, Hae-Kag; Lee, Sang-Jeong; Park, Cheol-Soo; Dong, Kyung-Rae; Park, Yong-Soon; Chung, Woon-Kwan; Lee, Jong-Woong; Kim, Ho-Sung; Kim, Eun-Hye; Kweon, Dae Cheol; Yeo, Hwa-Yeon

2013-02-01

In this study we used lumbar phantoms to determine if the BMD (bone mineral density) changes when only the thickness of soft tissue is increased. Second, we targeted osteoporosis patients to analyze the dependences of the changes in the SNR (signal-to-noise ratio) and the ADC (apparent diffusion coefficient) on changes in T-score. We used a bone mineral densitometer, phantoms such as an aluminum spine phantom (ASP), a Hologic spine phantom (HSP), and a European spine phantom (ESP), five sheets of acrylic panel, and a water bath to study the effects of changes in the thickness of soft tissue. First, we measured the ASP, the HSP and the ESP. For the measurement of the ASP, we filled it with water to increase the height by 0.5 cm starting from the baseline height. We then did three measurements for each height. For the measurements of the HSP and the ESP, we placed an acrylic panel on the phantom and then did three measurements at each height. We used the ASP to calculate the degree of precision of the standard mode and the thick mode at the maximum height of the water bath. To assess the degree of precision in the measurements of the three types of phantoms, we calculated precision errors and analyzed the correlation between the change in the thickness of soft tissue and the variables of the BMD. Using DWIs (diffusion weighted images), we targeted 30 healthy persons without osteoporosis and 30 patients with a finding of osteoporosis and measured the T-scores for the L1 — L4 (lumbar spine) segments of by the spine using the dual-energy X-ray absorptiometry (DXA) before classifying the measurement at each part of the spine as osteopenia or osteoporosis. We measured the signal intensity on all four parts of L1-L4 in the DWIs obtained using a 1.5T MR scanner and measured the ADC in the ADC map image. We compared changes in the SNR and the ADC for each group. The study results confirmed that an increase in the thickness of the soft tissue had a significant correlation

Hologic QDR 2000 whole-body scans: a comparison of three combinations of scan modes and analysis software

NASA Technical Reports Server (NTRS)

Spector, E.; LeBlanc, A.; Shackelford, L.

1995-01-01

This study reports on the short-term in vivo precision and absolute measurements of three combinations of whole-body scan modes and analysis software using a Hologic QDR 2000 dual-energy X-ray densitometer. A group of 21 normal, healthy volunteers (11 male and 10 female) were scanned six times, receiving one pencil-beam and one array whole-body scan on three occasions approximately 1 week apart. The following combinations of scan modes and analysis software were used: pencil-beam scans analyzed with Hologic's standard whole-body software (PB scans); the same pencil-beam analyzed with Hologic's newer "enhanced" software (EPB scans); and array scans analyzed with the enhanced software (EA scans). Precision values (% coefficient of variation, %CV) were calculated for whole-body and regional bone mineral content (BMC), bone mineral density (BMD), fat mass, lean mass, %fat and total mass. In general, there was no significant difference among the three scan types with respect to short-term precision of BMD and only slight differences in the precision of BMC. Precision of BMC and BMD for all three scan types was excellent: < 1% CV for whole-body values, with most regional values in the 1%-2% range. Pencil-beam scans demonstrated significantly better soft tissue precision than did array scans. Precision errors for whole-body lean mass were: 0.9% (PB), 1.1% (EPB) and 1.9% (EA). Precision errors for whole-body fat mass were: 1.7% (PB), 2.4% (EPB) and 5.6% (EA). EPB precision errors were slightly higher than PB precision errors for lean, fat and %fat measurements of all regions except the head, although these differences were significant only for the fat and % fat of the arms and legs. In addition EPB precision values exhibited greater individual variability than PB precision values. Finally, absolute values of bone and soft tissue were compared among the three combinations of scan and analysis modes. BMC, BMD, fat mass, %fat and lean mass were significantly different between

Expression of serum insulin-like growth factors, insulin-like growth factor-binding proteins, and the growth hormone-binding protein in heterozygote relatives of Ecuadorian growth hormone receptor deficient patients.

PubMed

Fielder, P J; Guevara-Aguirre, J; Rosenbloom, A L; Carlsson, L; Hintz, R L; Rosenfeld, R G

1992-04-01

Recently, an isolated population of apparent GH-receptor deficient (GHRD) patients has been identified in the Loja province of southern Ecuador. These individuals presented many of the physical and biochemical phenotypes characteristic of Laron-Syndrome and are believed to have a defect in the GH-receptor gene. In this study, we have compared the biochemical phenotypes between the affected individuals and their parents, considered to be obligate heterozygotes for the disorder. Serum GH, insulin-like growth factor I and II (IGF-I and IGF-II) levels were measured by RIA Insulin-like growth factor binding proteins. (IGFBPs) were measured by Western ligand blotting (WLB) of serum samples, following separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and relative quantitation of serum IGFBPs was performed with a scanning laser densitometer. Serum GH-binding protein (GHBP) levels were measured with a ligand-mediated immunofunctional assay using a monoclonal antibody raised against the GHBP. These values were then compared to values obtained from normal, sex-matched adult Ecuadorian controls, to determine if the above parameters were abnormal in the heterozygotes. The serum IGF-I levels of the GHRD patients were less than 13% of control values for adults and 2% for children. However, the IGF-I levels of both the mothers and fathers were not significantly different from that of the control population. The serum IGF-II levels of the GHRD patients were approximately 20% of control values for adults and 12% for the children. The IGF-II levels of the mothers were reduced, but were not significantly different from that of the control population. However, IGF-II levels of the fathers were significantly lower than those of controls (64% of control male levels). WLB analysis of serum IGFBP levels of the affected subjects demonstrated increased IGFBP-2 and decreased IGFBP-3, suggesting an inverse relationship between these IGFBPs. The GHRD patients who had the

Validation of Long Bone Mechanical Properties from Densitometry

NASA Technical Reports Server (NTRS)

Whalen, R.; Katz, B.; Cleek, T.; Hargens, Alan R. (Technical Monitor)

1995-01-01

The objective of this study was to assess whether cross-sectional areal properties, calculated from densitometry, correlate to the true flexural properties. Right and left male embalmed tibiae were used in the study. Prior to scanning, the proximal end of each tibia was potted in a fixture with registration pins, flushed thoroughly with water under pressure to remove trapped air, and then placed in a constant thickness water bath attached to a precision indexer. Two sets of three scans of the entire tibia were taken with an Hologic QDR 1000/W densitometer at rotations of 0, 45, and 90 degrees about the tibia long axis. An aluminum step phantom and a bone step phantom, machined from bovine cortical bone, were also in the bath and scanned separately. Pixel attenuation data from the two sets of scans were averaged to reduce noise. Pixel data from the high energy beam were then converted to equivalent thicknesses using calibration equations. Cross-sectional areal properties (centroid, principal area moments and principal angle) along the length were computed from the three registered scans using methods developed in our laboratory. Flexural rigidities. Four strain gages were bonded around the circumference of each of 5 cross-sections encompassing the entire diaphysis. A known transverse load was then applied to the distal end and the bone was rotated 360 degrees in eight increments of 45 degrees each. Strains from the eight orientations were analyzed along with the known applied bending moments at each section to compute section centroids, curvatures, principal flexural rigidities and principal angle. Reference axes between the two methods were maintained within +/- 0.5 degrees using an electronic inclinometer. Principal angles (flexural - areal) differed by -2.0 +/- 4.0 degrees, and 1.0 +/- 2.5 degrees for the right and left tibia, respectively. Section principal flexural rigidities were highly correlated to principal areal moments (right: r(sup 2)= 0.997; left: r

Mobile Munitions Assessment System Field Capabilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

A. M. Snyder; D. A. Verrill; K. D. Watts

1999-05-27

The US has developed, stored, tested, and conducted disposal operations on various forms of chemical munitions for several decades. The remnants of these activities have resulted in the presence of suspect CWM at more than 200 sites in the US, the District of Columbia, and the US Virgin Islands. An advanced Mobile Munitions Assessment System (Phase II MMAS) has been designed, fabricated, assembled, and tested by the Idaho National Engineering and Environmental Laboratory under contract to the US Army's Project Manager for Non-Stockpile Chemical Materiel for use in the assessment and characterization of ''non-stockpile'' chemical warfare materiel (CWM). The Phasemore » II MMAS meets the immediate need to augment response equipment currently used by the US Army with a system that includes state-of-the-art assessment equipment and advanced sensors. The Phase II MMAS will be used for response to known storage and remediation sites. This system is designed to identify the munition type; evaluate the condition of the CWM; evaluate the environmental conditions in the vicinity of the CWM; determine if fuzes, bursters, or safety and arming devices are in place; identify the chemical fill; provide other data (e.g., meteorological data) necessary for assessing the risk associated with handling, transporting, and disposing of CWM; and record the data on a dedicated computer system. The Phase II MMAS is capable of over-the-road travel and air transport to any site for conducting rigorous assessments of suspect CWM. The Phase II MMAS utilizes a specially-designed commercial motor home to provide a means to transport an interactive network of non-intrusive characterization and assessment equipment. The assessment equipment includes radiography systems, a gamma densitometer system, a Portable Isotopic Neutron Spectroscopy (PINS) system, a Secondary Ion Mass Spectroscopy (SIMS) system, air monitoring equipment (i.e., M-90s and a field ion spectroscopy system), and a phase

[Sufficiency with water-soluble vitamins and state of bone in pregnant women].

PubMed

Vrzhesinskaya, O A; Pereverzeva, O G; Gmoshinskaya, M V; Kodentsova, V M; Safronova, A I; Korosteleva, M M; Aleshina, I V; Fandeeva, T A

2015-01-01

Vitamin status and bone strength have been estimated in 91 pregnant women (29.3 ± 4.6 years old) from Moscow by non-invasive methods. Sufficiency with vitamins C, B2, B6 has been evaluated by morning urinary excretion of ascorbic acid, riboflavin and 4-piridoxic acid determined by visual titration and fluorimetric methods. The rate of bone resorption has been measured by the ratio of urinary calcium and creatinine, determined by complexometric titration and spectrophotometrically. The study of the bone strength has been conducted using an ultrasonic densitometer (the speed of the ultrasonic waves along the cortical layer). The lack of vitamin C was found in 20.4% .of the women surveyed, vitamin B2--in 27.4%. Vitamin B6 deficiency was detected most frequently (90%). Excretion of vitamins B2 and B6 in women in the third trimester of pregnancy was lower as compared with the women in the first and second trimester. In 53.3% of the women surveyed an increase in urinary excretion of calcium per creatinine has been observed. Excretion of group B vitamins (especially vitamin B6, 1.75 fold, p < 0.05) in women taking vitamin supplements was higher compared to non-taking vitamins that indicates the better sufficiency of the organism with these vitamins. Among women who took vitamin complexes, inadequate supply with water-soluble vitamins C, B2 and B6 was detected less frequently (the difference was significant for vitamin B2) than among women who did not intake vitamin complexes (in 11.9, 27.7 and 42.4% vs 16.1, 54.8 and 48.8 %). The rate of bone resorption (Ca/creatinine) in women taking vitamins was smaller (0.19 ± 0.09 vs 0.24 ± 0.14, p > 0.05). Ca/creatinine ratio was within normal range in 40% of women who intake vitamins, while in women not taking vitamins--only in 22.2%; this value exceeded the upper limit of norm in the rest. The strength of bone was broken in women in the second and third trimester of pregnancy, having worse supply of vitamins. The percentage of

The dense gas mass fraction in the W51 cloud and its protoclusters

NASA Astrophysics Data System (ADS)

Ginsburg, Adam; Bally, John; Battersby, Cara; Youngblood, Allison; Darling, Jeremy; Rosolowsky, Erik; Arce, Héctor; Lebrón Santos, Mayra E.

2015-01-01

Context. The density structure of molecular clouds determines how they will evolve. Aims: We map the velocity-resolved density structure of the most vigorously star-forming molecular cloud in the Galactic disk, the W51 giant molecular cloud. Methods: We present new 2 cm and 6 cm maps of H2CO, radio recombination lines, and the radio continuum in the W51 star forming complex acquired with Arecibo and the Green Bank Telescope at ~ 50″ resolution. We use H2CO absorption to determine the relative line-of-sight positions of molecular and ionized gas. We measure gas densities using the H2CO densitometer, including continuous measurements of the dense gas mass fraction (DGMF) over the range 104cm-3 104cm-3, while it is low, f< 20%, in W51 B. We did not detect any H2CO emission throughout the W51 GMC; all gas dense enough to emit under normal conditions is in front of bright continuum sources and therefore is seen in absorption instead. Conclusions: (1) The dense gas fraction in the W51 A and B clouds shows that W51 A will continue to form stars vigorously, while star formation has mostly ended in W51 B. The lack of dense, star-forming gas around W51 C indicates that collect-and-collapse is not acting or is inefficient in W51. (2) Ongoing high-mass star formation is correlated with n ≳ 1 × 105cm-3 gas. Gas with n> 104cm-3 is weakly correlated with low and moderate mass star formation, but does not strongly correlate with high-mass star formation. (3) The nondetection of H2CO emission implies that the emission detected in other galaxies, e.g. Arp 220, comes from high-density gas that is not directly affiliated with already-formed massive stars. Either the non-star-forming ISM of these galaxies is very dense, implying the star formation density threshold is higher, or H ii regions

White spotting variant (Wv) mouse as an experimental model for ovarian aging and menopausal biology

PubMed Central

Smith, Elizabeth R.; Yeasky, Toni; Wei, Jain Qin; Miki, Roberto A.; Cai, Kathy Q.; Smedberg, Jennifer L.; Yang, Wan-Lin; Xu, Xiang-Xi

2011-01-01

Objective Menopause is a unique phenomenon in modern women, as most mammalian species possess a reproductive period comparable to their lifespan. Menopause is caused by the depletion of germ cell-containing ovarian follicles, and in laboratory studies is usually modeled in animals in which the ovarian function is removed by ovariectomy or chemical poisoning of the germ cells. Our objective was to explore and characterize the white spotting variant (Wv) mice that have reduced ovarian germ cell abundance, a result of a point mutation in the c-kit gene that decreases the kinase activity, as a genetic model for use in menopausal studies. Methods Physiological and morphological features associated with menopause were determined in female Wv/Wv mice compared to age-matched wildtype controls. Immunohistochemistry was used to evaluate the presence and number of follicles in paraffin-embedded ovaries. Bone density and body composition were evaluated using the PIXImus X-ray densitometer, and lipids, calcium, and hormone levels were determined in serum using antigen-specific EIAs. Heart and body weight were measured, and cardiac function was evaluated by transthoracic echocardiography. Results The ovaries of the Wv/Wv females have a greatly reduced number of normal germ cells at birth compared to wildtype mice. The remaining follicles are depleted by around 2 months, and the ovaries develop benign epithelial lesions that resemble morphological changes that occur during ovarian aging, whereas a normal mouse ovary has numerous follicles at all stages of development and retains some follicles even in advanced age. Wv mice have elevated plasma gonadotrophins and reduced estrogen and progesterone levels, a significant reduction in bone mass density, and elevated serum cholesterol and lipoprotein levels. Moreover, the Wv female mice have enlarged hearts and reduced cardiac function. Conclusions The reduction of c-kit activity in Wv mice leads to a substantially diminished

White spotting variant mouse as an experimental model for ovarian aging and menopausal biology.

PubMed

Smith, Elizabeth R; Yeasky, Toni; Wei, Jain Qin; Miki, Roberto A; Cai, Kathy Q; Smedberg, Jennifer L; Yang, Wan-Lin; Xu, Xiang-Xi

2012-05-01

Menopause is a unique phenomenon in modern women, as most mammalian species possess a reproductive period comparable with their life span. Menopause is caused by the depletion of germ cell-containing ovarian follicles and in laboratory studies is usually modeled in animals in which the ovarian function is removed through ovariectomy or chemical poisoning of the germ cells. Our objective was to explore and characterize the white spotting variant (Wv) mice that have reduced ovarian germ cell abundance, a result of a point mutation in the c-kit gene that decreases kinase activity, as a genetic model for use in menopause studies. Physiological and morphological features associated with menopause were determined in female Wv/Wv mice compared with age-matched wildtype controls. Immunohistochemistry was used to evaluate the presence and number of follicles in paraffin-embedded ovaries. Bone density and body composition were evaluated using the PIXImus x-ray densitometer, and lipids, calcium, and hormone levels were determined in serum using antigen-specific enzyme immunoassays. Heart and body weight were measured, and cardiac function was evaluated using transthoracic echocardiography. The ovaries of the Wv/Wv females have a greatly reduced number of normal germ cells at birth compared with wildtype mice. The remaining follicles are depleted by around 2 months, and the ovaries develop benign epithelial lesions that resemble morphological changes that occur during ovarian aging, whereas a normal mouse ovary has numerous follicles at all stages of development and retains some follicles even in advanced age. Wv mice have elevated plasma gonadotropins and reduced estrogen and progesterone levels, a significant reduction in bone mass density, and elevated serum cholesterol and lipoprotein levels. Moreover, the Wv female mice have enlarged hearts and reduced cardiac function. The reduction of c-kit activity in Wv mice leads to a substantially diminished follicular endowment in

Meta-Analysis of Genome-Wide Scans Provides Evidence for Sex- and Site-Specific Regulation of Bone Mass

PubMed Central

Sham, Pak C; Zintzaras, Elias; Lewis, Cathryn M; Deng, Hong-Wen; Econs, Michael J; Karasik, David; Devoto, Marcella; Kammerer, Candace M; Spector, Tim; Andrew, Toby; Cupples, L Adrienne; Duncan, Emma L; Foroud, Tatiana; Kiel, Douglas P; Koller, Daniel; Langdahl, Bente; Mitchell, Braxton D; Peacock, Munro; Recker, Robert; Shen, Hui; Sol-Church, Katia; Spotila, Loretta D; Uitterlinden, Andre G; Wilson, Scott G; Kung, Annie WC; Ralston, Stuart H

2014-01-01

Several genome-wide scans have been performed to detect loci that regulate BMD, but these have yielded inconsistent results, with limited replication of linkage peaks in different studies. In an effort to improve statistical power for detection of these loci, we performed a meta-analysis of genome-wide scans in which spine or hip BMD were studied. Evidence was gained to suggest that several chromosomal loci regulate BMD in a site-specific and sex-specific manner. Introduction BMD is a heritable trait and an important predictor of osteoporotic fracture risk. Several genome-wide scans have been performed in an attempt to detect loci that regulate BMD, but there has been limited replication of linkage peaks between studies. In an attempt to resolve these inconsistencies, we conducted a collaborative meta-analysis of genome-wide linkage scans in which femoral neck BMD (FN-BMD) or lumbar spine BMD (LS-BMD) had been studied. Materials and Methods Data were accumulated from nine genome-wide scans involving 11,842 subjects. Data were analyzed separately for LS-BMD and FN-BMD and by sex. For each study, genomic bins of 30 cM were defined and ranked according to the maximum LOD score they contained. While various densitometers were used in different studies, the ranking approach that we used means that the results are not confounded by the fact that different measurement devices were used. Significance for high average rank and heterogeneity was obtained through Monte Carlo testing. Results For LS-BMD, the quantitative trait locus (QTL) with greatest significance was on chromosome 1p13.3-q23.3 (p = 0.004), but this exhibited high heterogeneity and the effect was specific for women. Other significant LS-BMD QTLs were on chromosomes 12q24.31-qter, 3p25.3-p22.1, 11p12-q13.3, and 1q32-q42.3, including one on 18p11-q12.3 that had not been detected by individual studies. For FN-BMD, the strongest QTL was on chromosome 9q31.1-q33.3 (p = 0.002). Other significant QTLs were

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abraham, TJ

A testing facility (Cold Test Loop) was constructed and operated to demonstrate the efficacy of the Accelerated Waste Retrieval (AWR) Project's planned sluicing approach to the remediation of Silos 1 and 2 at the Fernald Environmental Management Project near Cincinnati, Ohio. The two silos contain almost 10,000 tons of radium-bearing low-level waste, which consists primarily of solids of raffinates from processing performed on ores from the Democratic Republic of Congo (commonly referred to as ''Belgium Congo ores'') for the recovery of uranium. These silos are 80 ft in diameter, 36 ft high to the center of the dome, and 26.75more » ft to the top of the vertical side walls. The test facility contained two test systems, each designed for a specific purpose. The first system, the Integrated Test Loop (ITL), a near-full-scale plant including the actual equipment to be installed at the Fernald Site, was designed to demonstrate the sluicing operation and confirm the selection of a slurry pump, the optimal sluicing nozzle operation, and the preliminary design material balance. The second system, the Component Test Loop (CTL), was designed to evaluate many of the key individual components of the waste retrieval system over an extended run. The major results of the initial testing performed during July and August 2002 confirmed that the AWR approach to sluicing was feasible. The ITL testing confirmed the following: (1) The selected slurry pump (Hazleton 3-20 type SHW) performed well and is suitable for AWR application. However, the pump's motor should be upgraded to a 200-hp model and be driven by a 150-hp variable-frequency drive (VFD). A 200-hp VFD is not much more expensive and would allow the pump to operate at full speed. (2) The best nozzle performance was achieved by using 15/16-in. nozzles operated alternately. This configuration appeared to most effectively mine the surrogate. (3) The Solartron densitometer, which was tested as an alternative mass flow

[Role and functional spectrum of HPTLC in a hospital pharmaceutical quality control program].

PubMed

Bourget, P; Perello, L; Demirdjian, S

2001-02-01

As part of the development of a quality assurance program (QAP), a high performance thin layer chromatography (HPTLC) analysis unit was installed in the pharmacy department at Gustave-Roussy. The HPTLC-CAMAG consists of: 1) an HPTLC-Vario development chamber for optimization of the mobile phases; 2) TLC Sampler III automated sample applicators; 3) solid teflon migration chambers, i.e., horizontal tanks that enable separation to be carried out either in sandwich or in saturation mode; 4) a TLC Scanner 3 densitometer controlled by CATS 4 software; and 5) a Pentium MMX 233 MHz personal computer with an external backup unit. HPTLC quantitative and qualitative analysis has now reached a remarkably high level of development and performance. The samples (aqueous or non-aqueous solutions) that are to be processed are automatically applied by spraying (50-300 nl) in calibrated bands of a few mm (with up to 64 3-mm bands per 10 x 20 cm plate) on high-performance stationary phases and of wide technological diversity. The chromatogram is obtained in 10 min, and run over a migration pathway of 5-6 cm. The plates are read by absorption-reflection or fluorescence-reflection at an ad hoc wavelength (190-800 nm), then the peak areas which have been scanned are calculated by the trapezoid method. The calibration curves are generated by Michaelis-Menten non-linear regression, and validated by internal quality control. The analytical yield is high, i.e., up to 50 assays and 250 determinations per day. HPTLC analysis covers a wide functional range, and can be used in the following ways: 1) as a teaching tool for separative analysis and GLP; 2) it is an invaluable method for the optimization of mobile phases and for the determination of absorption spectra and absorption maxima, with a view to developing HPLC methods in complex matrices; 3) it provides major support for post-production quality control of prescribed hospital preparations of all types, e.g., those connected with parenteral

Nuclear DNA Amounts in Angiosperms: Progress, Problems and Prospects

PubMed Central

BENNETT, M. D.; LEITCH, I. J.

2005-01-01

densitometers used to measure DNA C-values proved less serious than feared, owing to the development of relatively inexpensive flow cytometers and computer-based image analysis systems. New uses of the term genome (e.g. in ‘complete’ genome sequencing) can cause confusion. The Arabidopsis Genome Initiative C-value for Arabidopsis thaliana (125 Mb) was a gross underestimate, and an exact C-value based on genome sequencing alone is unlikely to be obtained soon for any angiosperm. Lack of this expected benchmark poses a quandary as to what to use as the basal calibration standard for angiosperms. The next decade offers exciting prospects for angiosperm genome size research. The database (http://www.kew.org/cval/homepage) should become sufficiently representative of the global flora to answer most questions without needing new estimations. DNA amount variation will remain a key interest as an integrated strand of holistic genomics. PMID:15596457

Utilization of DXA Bone Mineral Densitometry in Ontario: An Evidence-Based Analysis.

PubMed

2006-01-01

Systematic reviews and analyses of administrative data were performed to determine the appropriate use of bone mineral density (BMD) assessments using dual energy x-ray absorptiometry (DXA), and the associated trends in wrist and hip fractures in Ontario. DUAL ENERGY X-RAY ABSORPTIOMETRY BONE MINERAL DENSITY ASSESSMENT: Dual energy x-ray absorptiometry bone densitometers measure bone density based on differential absorption of 2 x-ray beams by bone and soft tissues. It is the gold standard for detecting and diagnosing osteoporosis, a systemic disease characterized by low bone density and altered bone structure, resulting in low bone strength and increased risk of fractures. The test is fast (approximately 10 minutes) and accurate (exceeds 90% at the hip), with low radiation (1/3 to 1/5 of that from a chest x-ray). DXA densitometers are licensed as Class 3 medical devices in Canada. The World Health Organization has established criteria for osteoporosis and osteopenia based on DXA BMD measurements: osteoporosis is defined as a BMD that is >2.5 standard deviations below the mean BMD for normal young adults (i.e. T-score <-2.5), while osteopenia is defined as BMD that is more than 1 standard deviation but less than 2.5 standard deviation below the mean for normal young adults (i.e. T-score< -1 & ≥-2.5). DXA densitometry is presently an insured health service in Ontario.   BURDEN OF DISEASE: The Canadian Multicenter Osteoporosis Study (CaMos) found that 16% of Canadian women and 6.6% of Canadian men have osteoporosis based on the WHO criteria, with prevalence increasing with age. Osteopenia was found in 49.6% of Canadian women and 39% of Canadian men. In Ontario, it is estimated that nearly 530,000 Ontarians have some degrees of osteoporosis. Osteoporosis-related fragility fractures occur most often in the wrist, femur and pelvis. These fractures, particularly those in the hip, are associated with increased mortality, and decreased functional capacity and quality of

Utilization of DXA Bone Mineral Densitometry in Ontario

PubMed Central

2006-01-01

Executive Summary Issue Systematic reviews and analyses of administrative data were performed to determine the appropriate use of bone mineral density (BMD) assessments using dual energy x-ray absorptiometry (DXA), and the associated trends in wrist and hip fractures in Ontario. Background Dual Energy X-ray Absorptiometry Bone Mineral Density Assessment Dual energy x-ray absorptiometry bone densitometers measure bone density based on differential absorption of 2 x-ray beams by bone and soft tissues. It is the gold standard for detecting and diagnosing osteoporosis, a systemic disease characterized by low bone density and altered bone structure, resulting in low bone strength and increased risk of fractures. The test is fast (approximately 10 minutes) and accurate (exceeds 90% at the hip), with low radiation (1/3 to 1/5 of that from a chest x-ray). DXA densitometers are licensed as Class 3 medical devices in Canada. The World Health Organization has established criteria for osteoporosis and osteopenia based on DXA BMD measurements: osteoporosis is defined as a BMD that is >2.5 standard deviations below the mean BMD for normal young adults (i.e. T-score <–2.5), while osteopenia is defined as BMD that is more than 1 standard deviation but less than 2.5 standard deviation below the mean for normal young adults (i.e. T-score< –1 & ≥–2.5). DXA densitometry is presently an insured health service in Ontario. Clinical Need   Burden of Disease The Canadian Multicenter Osteoporosis Study (CaMos) found that 16% of Canadian women and 6.6% of Canadian men have osteoporosis based on the WHO criteria, with prevalence increasing with age. Osteopenia was found in 49.6% of Canadian women and 39% of Canadian men. In Ontario, it is estimated that nearly 530,000 Ontarians have some degrees of osteoporosis. Osteoporosis-related fragility fractures occur most often in the wrist, femur and pelvis. These fractures, particularly those in the hip, are associated with increased