Peri-implant assessment via cone beam computed tomography and digital periapical radiography: an ex vivo study.

PubMed

Silveira-Neto, Nicolau; Flores, Mateus Ericson; De Carli, João Paulo; Costa, Max Dória; Matos, Felipe de Souza; Paranhos, Luiz Renato; Linden, Maria Salete Sandini

2017-11-01

This research evaluated detail registration in peri-implant bone using two different cone beam computer tomography systems and a digital periapical radiograph. Three different image acquisition protocols were established for each cone beam computer tomography apparatus, and three clinical situations were simulated in an ex vivo fresh pig mandible: buccal bone defect, peri-implant bone defect, and bone contact. Data were subjected to two analyses: quantitative and qualitative. The quantitative analyses involved a comparison of real specimen measures using a digital caliper in three regions of the preserved buccal bone - A, B and E (control group) - to cone beam computer tomography images obtained with different protocols (kp1, kp2, kp3, ip1, ip2, and ip3). In the qualitative analyses, the ability to register peri-implant details via tomography and digital periapical radiography was verified, as indicated by twelve evaluators. Data were analyzed with ANOVA and Tukey's test (α=0.05). The quantitative assessment showed means statistically equal to those of the control group under the following conditions: buccal bone defect B and E with kp1 and ip1, peri-implant bone defect E with kp2 and kp3, and bone contact A with kp1, kp2, kp3, and ip2. Qualitatively, only bone contacts were significantly different among the assessments, and the p3 results differed from the p1 and p2 results. The other results were statistically equivalent. The registration of peri-implant details was influenced by the image acquisition protocol, although metal artifacts were produced in all situations. The evaluators preferred the Kodak 9000 3D cone beam computer tomography in most cases. The evaluators identified buccal bone defects better with cone beam computer tomography and identified peri-implant bone defects better with digital periapical radiography.

Searching early bone metastasis on plain radiography by using digital imaging processing

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

Jaramillo-Nunez, A.; Perez-Meza, M.; Universidad de la Sierra Sur, C. P. 70800, Miahuatlan, Oax.

2012-10-23

Some authors mention that it is not possible to detect early bone metastasis on plain radiography. In this work we use digital imaging processing to analyze three radiographs taken from a patient with bone metastasis discomfort on the right shoulder. The time period among the first and second radiography was approximately one month and between the first and the third one year. This procedure is a first approach in order to know if in this particular case it was possible to detect an early bone metastasis. The obtained results suggest that by carrying out a digital processing is possible tomore » detect the metastasis since the radiography contains the information although visually it is not possible to observe it.« less

Next-generation biomedical implants using additive manufacturing of complex, cellular and functional mesh arrays.

PubMed

Murr, L E; Gaytan, S M; Medina, F; Lopez, H; Martinez, E; Machado, B I; Hernandez, D H; Martinez, L; Lopez, M I; Wicker, R B; Bracke, J

2010-04-28

In this paper, we examine prospects for the manufacture of patient-specific biomedical implants replacing hard tissues (bone), particularly knee and hip stems and large bone (femoral) intramedullary rods, using additive manufacturing (AM) by electron beam melting (EBM). Of particular interest is the fabrication of complex functional (biocompatible) mesh arrays. Mesh elements or unit cells can be divided into different regions in order to use different cell designs in different areas of the component to produce various or continually varying (functionally graded) mesh densities. Numerous design elements have been used to fabricate prototypes by AM using EBM of Ti-6Al-4V powders, where the densities have been compared with the elastic (Young) moduli determined by resonant frequency and damping analysis. Density optimization at the bone-implant interface can allow for bone ingrowth and cementless implant components. Computerized tomography (CT) scans of metal (aluminium alloy) foam have also allowed for the building of Ti-6Al-4V foams by embedding the digital-layered scans in computer-aided design or software models for EBM. Variations in mesh complexity and especially strut (or truss) dimensions alter the cooling and solidification rate, which alters the alpha-phase (hexagonal close-packed) microstructure by creating mixtures of alpha/alpha' (martensite) observed by optical and electron metallography. Microindentation hardness measurements are characteristic of these microstructures and microstructure mixtures (alpha/alpha') and sizes.

Electromagnetic pulses bone healing booster

NASA Astrophysics Data System (ADS)

Sintea, S. R.; Pomazan, V. M.; Bica, D.; Grebenisan, D.; Bordea, N.

2015-11-01

Posttraumatic bone restoration triggered by the need to assist and stimulate compensatory bone growth in periodontal condition. Recent studies state that specific electromagnetic stimulation can boost the bone restoration, reaching up to 30% decrease in recovery time. Based on the existing data on the electromagnetic parameters, a digital electronic device is proposed for intra oral mounting and bone restoration stimulation in periodontal condition. The electrical signal is applied to an inductive mark that will create and impregnate magnetic field in diseased tissue. The device also monitors the status of the electromagnetic field. Controlled wave forms and pulse frequency signal at programmable intervals are obtained with optimized number of components and miniaturized using surface mounting devices (SMD) circuits and surface mounting technology (SMT), with enhanced protection against abnormal current growth, given the intra-oral environment. The system is powered by an autonomous power supply (battery), to limit the problems caused by powering medical equipment from the main power supply. Currently the device is used in clinical testing, in cycles of six up to twelve months. Basic principles for the electrical scheme and algorithms for pulse generation, pulse control, electromagnetic field control and automation of current monitoring are presented, together with the friendly user interface, suitable for medical data and patient monitoring.

Battling Brittle Bones

NASA Technical Reports Server (NTRS)

2002-01-01

The accuDEXA(R) Bone Mineral Density Assessment System, manufactured by Schick Technologies, Inc., utilizes "camera on a chip" sensor technology invented and developed by NASA's Jet Propulsion Laboratory. Schick's accuDEXA system offers several advantages over traditional osteoporosis tests, which assess bone density loss in the hip and spine, and require specialized personnel to conduct. With accuDEXA, physicians can test the entire body's bone density at a peripheral site, such as the finger, without applying gels or having patients remove garments. Results are achieved in 30 seconds and printed out in less than a minute, compared to the estimated exam time of 15 minutes for hip and spine density analyses. Schick has also applied the CMOS APS technology to a new software product that performs dental radiography using up to 90 percent less radiation exposure than conventional X-rays. Called Computed Dental Radiography(R), the new digital imaging product utilizes an electronic sensor in place of X-ray film to generate sharp and clear images that appear on a computer screen within 3 seconds, and can be enlarged and enhanced to identify problems.

Surface structural damage study in cortical bone due to medical drilling.

PubMed

Tavera R, Cesar G; De la Torre-I, Manuel H; Flores-M, Jorge M; Hernandez M, Ma Del Socorro; Mendoza-Santoyo, Fernando; Briones-R, Manuel de J; Sanchez-P, Jorge

2017-05-01

A bone's fracture could be produced by an excessive, repetitive, or sudden load. A regular medical practice to heal it is to fix it in two possible ways: external immobilization, using a ferule, or an internal fixation, using a prosthetic device commonly attached to the bone by means of surgical screws. The bone's volume loss due to this drilling modifies its structure either in the presence or absence of a fracture. To observe the bone's surface behavior caused by the drilling effects, a digital holographic interferometer is used to analyze the displacement surface's variations in nonfractured post-mortem porcine femoral bones. Several nondrilled post-mortem bones are compressed and compared to a set of post-mortem bones with a different number of cortical drillings. During each compression test, a series of digital interferometric holograms were recorded using a high-speed CMOS camera. The results are presented as pseudo 3D mesh displacement maps for comparisons in the physiological range of load (30 and 50 lbs) and beyond (100, 200, and 400 lbs). The high resolution of the optical phase gives a better understanding about the bone's microstructural modifications. Finally, a relationship between compression load and bone volume loss due to the drilling was observed. The results prove that digital holographic interferometry is a viable technique to study the conditions that avoid the surgical screw from loosening in medical procedures of this kind.

Image database for digital hand atlas

NASA Astrophysics Data System (ADS)

Cao, Fei; Huang, H. K.; Pietka, Ewa; Gilsanz, Vicente; Dey, Partha S.; Gertych, Arkadiusz; Pospiech-Kurkowska, Sywia

2003-05-01

Bone age assessment is a procedure frequently performed in pediatric patients to evaluate their growth disorder. A commonly used method is atlas matching by a visual comparison of a hand radiograph with a small reference set of old Greulich-Pyle atlas. We have developed a new digital hand atlas with a large set of clinically normal hand images of diverse ethnic groups. In this paper, we will present our system design and implementation of the digital atlas database to support the computer-aided atlas matching for bone age assessment. The system consists of a hand atlas image database, a computer-aided diagnostic (CAD) software module for image processing and atlas matching, and a Web user interface. Users can use a Web browser to push DICOM images, directly or indirectly from PACS, to the CAD server for a bone age assessment. Quantitative features on the examined image, which reflect the skeletal maturity, are then extracted and compared with patterns from the atlas image database to assess the bone age. The digital atlas method built on a large image database and current Internet technology provides an alternative to supplement or replace the traditional one for a quantitative, accurate and cost-effective assessment of bone age.

Evaluation of Biological Properties of Electron Beam Melted Ti6Al4V Implant with Biomimetic Coating In Vitro and In Vivo

PubMed Central

Wang, Cheng-Tao; Li, Guo-Chen; Lei, Wei; Zhang, Zhi-Yong; Wang, Lin

2012-01-01

Background High strength porous titanium implants are widely used for the reconstruction of craniofacial defects because of their similar mechanical properties to those of bone. The recent introduction of electron beam melting (EBM) technique allows a direct digitally enabled fabrication of patient specific porous titanium implants, whereas both their in vitro and in vivo biological performance need further investigation. Methods In the present study, we fabricated porous Ti6Al4V implants with controlled porous structure by EBM process, analyzed their mechanical properties, and conducted the surface modification with biomimetic approach. The bioactivities of EBM porous titanium in vitro and in vivo were evaluated between implants with and without biomimetic apatite coating. Results The physical property of the porous implants, containing the compressive strength being 163 - 286 MPa and the Young’s modulus being 14.5–38.5 GPa, is similar to cortical bone. The in vitro culture of osteoblasts on the porous Ti6Al4V implants has shown a favorable circumstance for cell attachment and proliferation as well as cell morphology and spreading, which were comparable with the implants coating with bone-like apatite. In vivo, histological analysis has obtained a rapid ingrowth of bone tissue from calvarial margins toward the center of bone defect in 12 weeks. We observed similar increasing rate of bone ingrowth and percentage of bone formation within coated and uncoated implants, all of which achieved a successful bridging of the defect in 12 weeks after the implantation. Conclusions This study demonstrated that the EBM porous Ti6Al4V implant not only reduced the stress-shielding but also exerted appropriate osteoconductive properties, as well as the apatite coated group. The results opened up the possibility of using purely porous titanium alloy scaffolds to reconstruct specific bone defects in the maxillofacial and orthopedic fields. PMID:23272208

High resolution electron microscopy study of crystal growth mechanisms in chicken bone composites

NASA Astrophysics Data System (ADS)

Cuisinier, F. J. G.; Steuer, P.; Brisson, A.; Voegel, J. C.

1995-12-01

The present study describes the early stages of chicken bone crystal growth, followed by high resolution electron microscopy (HREM). We have developed an original analysis procedure to determine the crystal structure. Images were first digitalized and selected areas were fast Fourier transformed. Numerical masks were selected around the most intense spots and the filtered signal was retransformed back to real space. The filtered images were then compared to computer calculated images to identify the inorganic mineral phase. Nanometer-sized particles were observed on amorphous areas. These particles have a structure loosely related to hydroxyapatite (HA) and a specific orientation. In a more advanced situation, the nanoparticles appeared to grow in two dimensions and to form plate-like crystals. These crystals seem, in a last growth step, to fuse by their (100) faces. These experimental observations allowed us to propose a four-step model for the development and growth of chicken bone crystals. The two initial stages are the ionic adsorption onto the organic substrate followed by the nucleation of nanometer-sized particles. The two following steps, i.e. two-dimensional growth of the nanoparticles leading to the formation of needle-like crystals, and the lateral fusion of these crystals by their (100) faces, are controlled only by spatial constraints inside the extracellular organic matrix.

Digital image processing of bone - Problems and potentials

NASA Technical Reports Server (NTRS)

Morey, E. R.; Wronski, T. J.

1980-01-01

The development of a digital image processing system for bone histomorphometry and fluorescent marker monitoring is discussed. The system in question is capable of making measurements of UV or light microscope features on a video screen with either video or computer-generated images, and comprises a microscope, low-light-level video camera, video digitizer and display terminal, color monitor, and PDP 11/34 computer. Capabilities demonstrated in the analysis of an undecalcified rat tibia include the measurement of perimeter and total bone area, and the generation of microscope images, false color images, digitized images and contoured images for further analysis. Software development will be based on an existing software library, specifically the mini-VICAR system developed at JPL. It is noted that the potentials of the system in terms of speed and reliability far exceed any problems associated with hardware and software development.

Digital subtraction radiographic analysis of the combination of bioabsorbable membrane and bovine morphogenetic protein pool in human periodontal infrabony defects

PubMed Central

GUIMARÃES, Maria do Carmo Machado; PASSANEZI, Euloir; SANT’ANA, Adriana Campos Passanezi; GREGHI, Sebastião Luiz Aguiar; TABA JUNIOR, Mario

2010-01-01

Objectives This study assessed the bone density gain and its relationship with the periodontal clinical parameters in a case series of a regenerative therapy procedure. Material and Methods Using a split-mouth study design, 10 pairs of infrabony defects from 15 patients were treated with a pool of bovine bone morphogenetic proteins associated with collagen membrane (test sites) or collagen membrane only (control sites). The periodontal healing was clinically and radiographically monitored for six months. Standardized presurgical and 6-month postoperative radiographs were digitized for digital subtraction analysis, which showed relative bone density gain in both groups of 0.034 ± 0.423 and 0.105 ± 0.423 in the test and control group, respectively (p>0.05). Results As regards the area size of bone density change, the influence of the therapy was detected in 2.5 mm2 in the test group and 2 mm2 in the control group (p>0.05). Additionally, no correlation was observed between the favorable clinical results and the bone density gain measured by digital subtraction radiography (p>0.05). Conclusions The findings of this study suggest that the clinical benefit of the regenerative therapy observed did not come with significant bone density gains. Long-term evaluation may lead to a different conclusions. PMID:20835573

Effect of bone chip orientation on quantitative estimates of changes in bone mass using digital subtraction radiography.

PubMed

Mol, André; Dunn, Stanley M

2003-06-01

To assess the effect of the orientation of arbitrarily shaped bone chips on the correlation between radiographic estimates of bone loss and true mineral loss using digital subtraction radiography. Twenty arbitrarily shaped bone chips (dry weight 1-10 mg) were placed individually on the superior lingual aspect of the interdental alveolar bone of a dry dentate hemi-mandible. After acquiring the first baseline image, each chip was rotated 90 degrees and a second radiograph was captured. Follow-up images were created without the bone chips and after rotating the mandible 0, 1, 2, 4, and 6 degrees around a vertical axis. Aluminum step tablet intensities were used to normalize image intensities for each image pair. Follow-up images were registered and geometrically standardized using projective standardization. Bone chips were dry ashed and analyzed for calcium content using atomic absorption. No significant difference was found between the radiographic estimates of bone loss from the different bone chip orientations (Wilcoxon: P > 0.05). The correlation between the two series of estimates for all rotations was 0.93 (Spearman: P < 0.05). Linear regression analysis indicated that both correlates did not differ appreciably ( and ). It is concluded that the spatial orientation of arbitrarily shaped bone chips does not have a significant impact on quantitative estimates of changes in bone mass in digital subtraction radiography. These results were obtained in the presence of irreversible projection errors of up to six degrees and after application of projective standardization for image reconstruction and image registration.

Mechanics of evolutionary digit reduction in fossil horses (Equidae).

PubMed

McHorse, Brianna K; Biewener, Andrew A; Pierce, Stephanie E

2017-08-30

Digit reduction is a major trend that characterizes horse evolution, but its causes and consequences have rarely been quantitatively tested. Using beam analysis on fossilized centre metapodials, we tested how locomotor bone stresses changed with digit reduction and increasing body size across the horse lineage. Internal bone geometry was captured from 13 fossil horse genera that covered the breadth of the equid phylogeny and the spectrum of digit reduction and body sizes, from Hyracotherium to Equus To account for the load-bearing role of side digits, a novel, continuous measure of digit reduction was also established-toe reduction index (TRI). Our results show that without accounting for side digits, three-toed horses as late as Parahippus would have experienced physiologically untenable bone stresses. Conversely, when side digits are modelled as load-bearing, species at the base of the horse radiation through Equus probably maintained a similar safety factor to fracture stress. We conclude that the centre metapodial compensated for evolutionary digit reduction and body mass increases by becoming more resistant to bending through substantial positive allometry in internal geometry. These results lend support to two historical hypotheses: that increasing body mass selected for a single, robust metapodial rather than several smaller ones; and that, as horse limbs became elongated, the cost of inertia from the side toes outweighed their utility for stabilization or load-bearing. © 2017 The Author(s).

An automatic early stage alveolar-bone-resorption evaluation method on digital dental panoramic radiographs

NASA Astrophysics Data System (ADS)

Zhang, Min; Katsumata, Akitoshi; Muramatsu, Chisako; Hara, Takeshi; Suzuki, Hiroki; Fujita, Hiroshi

2014-03-01

Periodontal disease is a kind of typical dental diseases, which affects many adults. The presence of alveolar bone resorption, which can be observed from dental panoramic radiographs, is one of the most important signs of the progression of periodontal disease. Automatically evaluating alveolar-bone resorption is of important clinic meaning in dental radiology. The purpose of this study was to propose a novel system for automated alveolar-bone-resorption evaluation from digital dental panoramic radiographs for the first time. The proposed system enables visualization and quantitative evaluation of alveolar bone resorption degree surrounding the teeth. It has the following procedures: (1) pre-processing for a test image; (2) detection of tooth root apices with Gabor filter and curve fitting for the root apex line; (3) detection of features related with alveolar bone by using image phase congruency map and template matching and curving fitting for the alveolar line; (4) detection of occlusion line with selected Gabor filter; (5) finally, evaluation of the quantitative alveolar-bone-resorption degree in the area surrounding teeth by simply computing the average ratio of the height of the alveolar bone and the height of the teeth. The proposed scheme was applied to 30 patient cases of digital panoramic radiographs, with alveolar bone resorption of different stages. Our initial trial on these test cases indicates that the quantitative evaluation results are correlated with the alveolar-boneresorption degree, although the performance still needs further improvement. Therefore it has potential clinical practicability.

The Digital Astronaut Project Bone Remodeling Model

NASA Technical Reports Server (NTRS)

Pennline, James A.; Mulugeta, Lealem; Lewandowski, Beth E.; Thompson, William K.; Sibonga, Jean D.

2014-01-01

Under the conditions of microgravity, astronauts lose bone mass at a rate of 1% to 2% a month, particularly in the lower extremities such as the proximal femur: (1) The most commonly used countermeasure against bone loss has been prescribed exercise, (2) However, current exercise countermeasures do not completely eliminate bone loss in long duration, 4 to 6 months, spaceflight, (3,4) leaving the astronaut susceptible to early onset osteoporosis and a greater risk of fracture later in their lives. The introduction of the Advanced Resistive Exercise Device, coupled with improved nutrition, has further minimized the 4 to 6 month bone loss. But further work is needed to implement optimal exercise prescriptions, and (5) In this light, NASA's Digital Astronaut Project (DAP) is working with NASA physiologists to implement well-validated computational models that can help understand the mechanisms of bone demineralization in microgravity, and enhance exercise countermeasure development.

Data mining for average images in a digital hand atlas

NASA Astrophysics Data System (ADS)

Zhang, Aifeng; Cao, Fei; Pietka, Ewa; Liu, Brent J.; Huang, H. K.

2004-04-01

Bone age assessment is a procedure performed in pediatric patients to quickly evaluate parameters of maturation and growth from a left hand and wrist radiograph. Pietka and Cao have developed a Computer-aided diagnosis (CAD) method of bone age assessment based on a digital hand atlas. The aim of this paper is to extend their work by automatically select the best representative image from a group of normal children based on specific bony features that reflect skeletal maturity. The group can be of any ethnic origin and gender from one year to 18 year old in the digital atlas. This best representative image is defined as the "average" image of the group that can be augmented to Piekta and Cao's method to facilitate in the bone age assessment process.

Use of early tactile stimulation in rehabilitation of digital nerve injuries.

PubMed

Cheng, A S

2000-01-01

Digital nerves are the most frequently injured peripheral nerve. To improve the recovery of functional sensibility of digital nerve injuries, a prospective randomized controlled study was conducted to see the effect of using early tactile stimulation in rehabilitation of digital nerve injuries. Two specific tactile stimulators were made and prescribed for patients with digital nerve-injury. Twenty-four participants with 32 digital nerve injuries received the prescribed tactile stimulators (experimental group), and another 25 participants with 33 digital nerve injuries received only routine conventional therapy (control group). A significant difference (p < .05) was seen in the experimental group, although there were some variations between the different classes of associated injuries, with least benefit observed in the combined nerve, tendon, and bone injury class. Use of early tactile stimulation as described in this study can be considered an effective way to improve both quality and quantity of recovery of functional sensibility in digital nerve injuries without combined nerve, tendon, and bone injuries.

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.

Lead Levels in Utah Eagles

NASA Astrophysics Data System (ADS)

Arnold, Michelle

2006-10-01

Lead is a health hazard to most animals, causing adverse effects to the nervous and reproductive systems if in sufficient quantity. Found in most fishing jigs and sinkers, as well as some ammunition used in hunting, this metal can poison wildlife such as eagles. Eagles are raptors, or predatory birds, and their lead exposure would most likely comes from their food -- a fish which has swallowed a sinker or lead shot in carrion (dead animal matter). As part of an ongoing project to investigate the environment lead levels in Utah, the bone lead levels in the wing bones of eagles have been measured for eagle carcasses found throughout Utah. The noninvasive technique of x-ray fluorescence was used, consisting of a Cd-109 radioactive source to activate lead atoms and a HPGe detector with digital electronics to collect the gamma spectra. Preliminary results for the eagles measured to date will be presented.

Highly sensitive MYD88L265P mutation detection by droplet digital PCR in Waldenström Macroglobulinemia.

PubMed

Drandi, Daniela; Genuardi, Elisa; Dogliotti, Irene; Ferrante, Martina; Jiménez, Cristina; Guerrini, Francesca; Lo Schirico, Mariella; Mantoan, Barbara; Muccio, Vittorio; Lia, Giuseppe; Zaccaria, Gian Maria; Omedè, Paola; Passera, Roberto; Orsucci, Lorella; Benevolo, Giulia; Cavallo, Federica; Galimberti, Sara; García-Sanz, Ramón; Boccadoro, Mario; Ladetto, Marco; Ferrero, Simone

2018-03-22

We here describe a novel method for MYD88 L265P mutation detection and minimal residual disease monitoring in Waldenström Macroglobulinemia, by droplet digital PCR, in bone marrow and peripheral blood cells, as well as in circulating cell free DNA. Our method shows a sensitivity of 5.00E-05, by far superior to the widely used allele-specific polymerase chain reaction (1.00E-03). Overall, 291 unsorted samples from 148 patients (133 Waldenstrom 11 IgG-lymphoplasmacytic lymphoma and 4 IgM-monoclonal gammopathy of undetermined significance), 194 baseline and 97 follow-up, were analyzed. 122/128 (95.3%) bone marrow and 47/66 (71.2%) baseline peripheral blood samples scored positive for MYD88 L265P Moreover, to investigate whether MYD88 L265P by droplet digital PCR could be used for minimal residual disease monitoring, mutation levels were compared with IGH-based minimal residual disease analysis in 10 patients, showing to be as informative as to the classical, standardized but not yet validated in Waldenström Macroglobulinemia, IGH-based minimal residual disease assay (r 2 =0.64). Finally, MYD88 L265P detection performed by droplet digital PCR on plasmatic circulating tumor DNA from 60 patients showed a good correlation with bone marrow (bone marrow median mutational value 1.92E-02, plasmatic circulating tumor DNA value: 1.4E-02, peripheral blood value: 1.03E-03). This study indicates that droplet digital PCR MYD88 L265P assay is a feasible and sensitive tool for mutational screening and minimal residual disease monitoring in Waldenström Macroglobulinemia. Both unsorted bone marrow and peripheral blood samples can be reliably tested, as well as circulating tumor DNA, that represents an attractive, less invasive alternative to bone marrow for MYD88 L265P detection. Copyright © 2018, Ferrata Storti Foundation.

Prosthetically guided bone sculpturing for a maxillary complete-arch implant-supported monolithic zirconia fixed prosthesis based on a digital smile design: A clinical report.

PubMed

Rojas-Vizcaya, Fernando

2017-11-01

A digital smile design was used to create an average smile and to develop a removable interim restoration for an edentulous patient with a high smile line and different bone levels in the maxilla. The interim restoration was used as a guide to perform bone sculpturing to create space for the biological width and to restore a monolithic zirconia implant-supported fixed restoration. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Bone modeling and cell-material interface responses induced by nickel-titanium shape memory alloy after periosteal implantation.

PubMed

Ryhänen, J; Kallioinen, M; Tuukkanen, J; Lehenkari, P; Junila, J; Niemelä, E; Sandvik, P; Serlo, W

1999-07-01

The purpose of this study was to evaluate the new bone formation, modeling and cell-material interface responses induced by nickel-titanium shape memory alloy after periosteal implantation. We used a regional acceleratory phenomenon (RAP) model, in which a periosteal contact stimulus provokes an adaptive modelling response. NiTi has thermal shape memory and superelasticity properties uncommon in other implant alloys. So far, there are insufficient data concerning the biocompatibility of NiTi as a bone implant. NiTi was compared to stainless steel (stst) and Ti-6Al-4V. The test implant was placed in contact with the intact femur periosteum, but it was not fixed inside the bone. Histomorphometry with digital image analysis was used to determine the bone formation and resorption parameters. The ultrastructural features of cell-material adhesion were analysed with scanning electron microscopy (FESEM). A typical peri-implant bone wall modelation was seen due to the normal RAP. The maximum new woven bone formation started earlier (2 weeks) in the Ti-6Al-4V group than in the NiTi (P < 0.01) group, but also decreased earlier, and at 8 weeks the NiTi (P < 0.05) and stst (P < 0.005) groups had greater cortical bone width. At 12 and 26 weeks no statistical differences were seen in the histomorphometric values. The histological response of the soft tissues around the NiTi implant was also clearly non-toxic and non-irritating. Cell adhesion and focal contacts were similar between the materials studied by FESEM. We conclude that NiTi had no negative effect on total new bone formation or normal RAP after periosteal implantation during a 26-week follow-up.

Bone Age Assessment of Children using a Digital Hand Atlas

PubMed Central

Gertych, Arkadiusz; Zhang, Aifeng; Sayre, James; Pospiech-Kurkowska, Sylwia; Huang, H.K

2007-01-01

We have developed an automated method to assess bone age of children using a digital hand atlas. The hand Atlas consists of two components. The first component is a database which is comprised of a collection of 1,400 digitized left hand radiographs from evenly distributed normally developed children of Caucasian (CA), Asian (AS), African-American (AA) and Hispanic (HI) origin, male (M) and female (F), ranged from 1 to 18 year old; and relevant patient demographic data along with pediatric radiologists' readings of each radiograph. This data is separate into eight categories: CAM, CAF, AAM, AAF, HIM, HIF, ASM, and ASF. In addition, CAM, AAM, HIM, and ASM are combined as one male category; and CAF, AAF, HIF, and ASF are combined as one female category. The male and female are further combined as the F & M category. The second component is a computer-assisted diagnosis (CAD) module to assess a child bone age based on the collected data. The CAD method is derived from features extracted from seven regions of interest (ROIs): the carpal bone ROI, and six phanlangeal PROIs. The PROIs are six areas including the distal and middle regions of three middle fingers. These features were used to train the eleven category fuzzy classifiers: one for each race and gender, one for the female, one male, and one F & M, to assess the bone age of a child. The digital hand atlas is being integrated with a PACS for validation of clinical use. PMID:17387000

Is Greulich and Pyle atlas still a good reference for bone age assessment?

NASA Astrophysics Data System (ADS)

Zhang, Aifeng; Tsao, Sinchai; Sayre, James W.; Gertych, Arkadiusz; Liu, Brent J.; Huang, H. K.

2007-03-01

The most commonly used method for bone age assessment in clinical practice is the book atlas matching method developed by Greulich and Pyle in the 1950s. Due to changes in both population diversity and nutrition in the United States, this atlas may no longer be a good reference. An updated data set becomes crucial to improve the bone age assessment process. Therefore, a digital hand atlas was built with 1,100 children hand images, along with patient information and radiologists' readings, of normal Caucasian (CAU), African American (BLK), Hispanic (HIS), and Asian (ASI) males (M) and females (F) with ages ranging from 0 - 18 years. This data was collected from Childrens' Hospital Los Angeles. A computer-aided-diagnosis (CAD) method has been developed based on features extracted from phalangeal regions of interest (ROIs) and carpal bone ROIs from this digital hand atlas. Using the data collected along with the Greulich and Pyle Atlas-based readings and CAD results, this paper addresses this question: "Do different ethnicities and gender have different bone growth patterns?" To help with data analysis, a novel web-based visualization tool was developed to demonstrate bone growth diversity amongst differing gender and ethnic groups using data collected from the Digital Atlas. The application effectively demonstrates a discrepancy of bone growth pattern amongst different populations based on race and gender. It also has the capability of helping a radiologist determine the normality of skeletal development of a particular patient by visualizing his or her chronological age, radiologist reading, and CAD assessed bone age relative to the accuracy of the P&G method.

47 CFR 32.6212 - Digital electronic switching expense.

Code of Federal Regulations, 2014 CFR

2014-10-01

... with digital electronic switching equipment used to provide circuit switching. (c) This subaccount 6212... 47 Telecommunication 2 2014-10-01 2014-10-01 false Digital electronic switching expense. 32.6212... Digital electronic switching expense. (a) This account shall include expenses associated with digital...

47 CFR 32.6212 - Digital electronic switching expense.

Code of Federal Regulations, 2011 CFR

2011-10-01

... with digital electronic switching equipment used to provide circuit switching. (c) This subaccount 6212... 47 Telecommunication 2 2011-10-01 2011-10-01 false Digital electronic switching expense. 32.6212... Digital electronic switching expense. (a) This account shall include expenses associated with digital...

47 CFR 32.6212 - Digital electronic switching expense.

Code of Federal Regulations, 2013 CFR

2013-10-01

... with digital electronic switching equipment used to provide circuit switching. (c) This subaccount 6212... 47 Telecommunication 2 2013-10-01 2013-10-01 false Digital electronic switching expense. 32.6212... Digital electronic switching expense. (a) This account shall include expenses associated with digital...

47 CFR 32.6212 - Digital electronic switching expense.

Code of Federal Regulations, 2010 CFR

2010-10-01

... with digital electronic switching equipment used to provide circuit switching. (c) This subaccount 6212... 47 Telecommunication 2 2010-10-01 2010-10-01 false Digital electronic switching expense. 32.6212... Digital electronic switching expense. (a) This account shall include expenses associated with digital...

47 CFR 32.6212 - Digital electronic switching expense.

Code of Federal Regulations, 2012 CFR

2012-10-01

... with digital electronic switching equipment used to provide circuit switching. (c) This subaccount 6212... 47 Telecommunication 2 2012-10-01 2012-10-01 false Digital electronic switching expense. 32.6212... Digital electronic switching expense. (a) This account shall include expenses associated with digital...

Analysis of fractal dimensions of rat bones from film and digital images

NASA Technical Reports Server (NTRS)

Pornprasertsuk, S.; Ludlow, J. B.; Webber, R. L.; Tyndall, D. A.; Yamauchi, M.

2001-01-01

OBJECTIVES: (1) To compare the effect of two different intra-oral image receptors on estimates of fractal dimension; and (2) to determine the variations in fractal dimensions between the femur, tibia and humerus of the rat and between their proximal, middle and distal regions. METHODS: The left femur, tibia and humerus from 24 4-6-month-old Sprague-Dawley rats were radiographed using intra-oral film and a charge-coupled device (CCD). Films were digitized at a pixel density comparable to the CCD using a flat-bed scanner. Square regions of interest were selected from proximal, middle, and distal regions of each bone. Fractal dimensions were estimated from the slope of regression lines fitted to plots of log power against log spatial frequency. RESULTS: The fractal dimensions estimates from digitized films were significantly greater than those produced from the CCD (P=0.0008). Estimated fractal dimensions of three types of bone were not significantly different (P=0.0544); however, the three regions of bones were significantly different (P=0.0239). The fractal dimensions estimated from radiographs of the proximal and distal regions of the bones were lower than comparable estimates obtained from the middle region. CONCLUSIONS: Different types of image receptors significantly affect estimates of fractal dimension. There was no difference in the fractal dimensions of the different bones but the three regions differed significantly.

A light and scanning electron microscopic evaluation of electro-discharge-compacted porous titanium implants in rabbit tibia.

PubMed

Drummond, J F; Dominici, J T; Sammon, P J; Okazaki, K; Geissler, R; Lifland, M I; Anderson, S A; Renshaw, W

1995-01-01

This study used light and scanning electron microscopic (SEM) histomorphometric methods to quantitate the rate of osseointegration of totally porous titanium alloy (Ti-6Al-4V) implants prepared by a novel fabrication technique--electrodischarge compaction (EDC). EDC was used to fuse 150-250-micrometer spherical titanium alloy beads into 4 X 6 mm cylindrical implants through application of a 300-microsecond pulse of high-voltage/high-current density. Two sterilized implants were surgically placed into each tibia of 20 New Zealand white rabbits and left in situ for periods corresponding to 2, 4, 8, 12, and 24 weeks. At each time point, 4 rabbits were humanely killed, and the implants with surrounding bone were removed, fixed, and sectioned for light and SEM studies. The degree of osseointegration was quantitated by means of a True Grid Digitizing Pad and Jandel Scan Version 3.9 software on an IBM PS/2 computer. The total pore area occupied by bone was divided by the total pore area available for bone ingrowth, and a Bone Ingrowth Factor (BIF) was calculated as a percent. The light microscopic results showed BIFs of 4% at week 2, 47% at week 4, 62% at week 8, 84% at week 12, and greater than 90% at week 24. The SEM results showed BIFs of 5% at week 2, 34% at week 4, 69% at week 8, 75% at week 12, and in excess of 90% at week 24. The results of this study show that EDC implants are biocompatible and support rapid osseointegration in the rabbit tibia and suggest that, after additional studies, they may be suitable for use as dental implants in humans.

Correlation between radiographic analysis of alveolar bone density around dental implant and resonance frequency of dental implant

NASA Astrophysics Data System (ADS)

Prawoko, S. S.; Nelwan, L. C.; Odang, R. W.; Kusdhany, L. S.

2017-08-01

The histomorphometric test is the gold standard for dental implant stability quantification; however, it is invasive, and therefore, it is inapplicable to clinical patients. Consequently, accurate and objective alternative methods are required. Resonance frequency analysis (RFA) and digital radiographic analysis are noninvasive methods with excellent objectivity and reproducibility. To analyze the correlation between the radiographic analysis of alveolar bone density around a dental implant and the resonance frequency of the dental implant. Digital radiographic images for 35 samples were obtained, and the resonance frequency of the dental implant was acquired using Osstell ISQ immediately after dental implant placement and on third-month follow-up. The alveolar bone density around the dental implant was subsequently analyzed using SIDEXIS-XG software. No significant correlation was reported between the alveolar bone density around the dental implant and the resonance frequency of the dental implant (r = -0.102 at baseline, r = 0.146 at follow-up, p > 0.05). However, the alveolar bone density and resonance frequency showed a significant difference throughout the healing period (p = 0.005 and p = 0.000, respectively). Conclusion: Digital dental radiographs and Osstell ISQ showed excellent objectivity and reproducibility in quantifying dental implant stability. Nonetheless, no significant correlation was observed between the results obtained using these two methods.

Digital front end electronics design for the EUSO photon detector

NASA Astrophysics Data System (ADS)

Musico, P.; Pallavicini, M.; Petrolini, A.; Pratolongo, F.

2003-09-01

In this paper we will present the design status of the Digital Front End Electronic system (DFEE), that will be used for the EUSO photon detector. The DFEE is able to count the single photoelectrons coming form the detector for a given time period, store the numbers in a memory buffer and read them out after a trigger, using a serial communication line. Because of space, mass and power consumption constraints, the system will be implemented in an ASIC using a deep submicron technology. The actual design follows the original ideas of the system, though adding several new functionalities. A fully functional prototype chip has been submitted for fabrication in fall 2002. Extensive tests will be performed on it both with bench instrumentations and with the real sensor (the multi anode photomultiplier Hamamatsu R7600-M64), expecting significant results by early Summer 2003. Future work is needed to convert the design into a more robust RAD-hard technology, suitable for space applications and to include in the final die an additional circuit used to optimize the performances at high photons rates: the Analog Front End Electronics (AFEE). Moreover the base board used to house the multi anode photomultipliers is presented: it is the back-bone of the microcell and will be the basic block used to build up the EUSO focal surface.

The Digital Astronaut Project Bone Remodeling Model

NASA Technical Reports Server (NTRS)

Pennline, J. A.; Mulugeta, L.; Lewandowski, B. E.; Thompson, W. K.; Sibonga, J. D.

2013-01-01

One of the main objectives is to provide a tool to help HHC address Bone Gap Osteo 4: We don't know the contribution of each risk factor on bone loss and recovery of bone strength and which factors are the best targets for countermeasure application; and Osteo7: We need to identify options for mitigation of early onset osteoporosis before, during, and after spaceflight.

Is complex signal processing for bone conduction hearing aids useful?

PubMed

Kompis, Martin; Kurz, Anja; Pfiffner, Flurin; Senn, Pascal; Arnold, Andreas; Caversaccio, Marco

2014-05-01

To establish whether complex signal processing is beneficial for users of bone anchored hearing aids. Review and analysis of two studies from our own group, each comparing a speech processor with basic digital signal processing (either Baha Divino or Baha Intenso) and a processor with complex digital signal processing (either Baha BP100 or Baha BP110 power). The main differences between basic and complex signal processing are the number of audiologist accessible frequency channels and the availability and complexity of the directional multi-microphone noise reduction and loudness compression systems. Both studies show a small, statistically non-significant improvement of speech understanding in quiet with the complex digital signal processing. The average improvement for speech in noise is +0.9 dB, if speech and noise are emitted both from the front of the listener. If noise is emitted from the rear and speech from the front of the listener, the advantage of the devices with complex digital signal processing as opposed to those with basic signal processing increases, on average, to +3.2 dB (range +2.3 … +5.1 dB, p ≤ 0.0032). Complex digital signal processing does indeed improve speech understanding, especially in noise coming from the rear. This finding has been supported by another study, which has been published recently by a different research group. When compared to basic digital signal processing, complex digital signal processing can increase speech understanding of users of bone anchored hearing aids. The benefit is most significant for speech understanding in noise.

Removal of Dental Implants Using the Erbium,Chromium:Yttrium-Scandium-Gallium-Garnet Laser and the Conventional Trephine Bur: An in Vitro Comparative Study.

PubMed

Hajji, Mohammad; Franzen, Rene; Grümer, Stefan; Modabber, Ali; Nasher, Riman; Prescher, Andreas; Gutknecht, Norbert

2016-02-01

The purpose of this study was to compare the conventional trephine bur and the Erbium,chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser in removing implants in terms of the volume of removed bone, duration of the procedure, and morphological changes on the bone surface. Three human mandibles were utilized, and four implants were inserted in each mandible using a drilling handpiece and burs. The implants were divided into two groups (n = 6) in which two implants from each mandible were removed using a trephine bur running at 1200 rounds per minute (rpm) with water irrigation. The remaining implants (n = 6) were removed with Er,Cr:YSGG laser (power 6 W, frequency 20 Hz, pulse duration 50 μs, water 60, air 30). The volume of bone loss was calculated by filling the holes with mercury and measuring its volume. The preparation time was measured with a digital stopwatch and the postoperative bone surfaces were examined under a scanning electron microscope (SEM). The laser group exhibited a smaller amount of bone loss than the trephine bur group, whereas the latter required a shorter time of preparation. SEM revealed empty trabecular spaces with no signs of carbonization and well-defined edges in the laser group, whereas the trephine group displayed a surface covered with a smear layer and microcracks. The Er,Cr:YSGG laser provides superior results over the trephine bur in terms of bone preservation, thermal damage, and cutting efficiency.

Present and Future Applications of Digital Electronics in Nuclear Science - a Commercial Prospective

NASA Astrophysics Data System (ADS)

Tan, Hui

2011-10-01

Digital readout electronics instrumenting radiation detectors have experienced significant advancements in the last decade or so. This on one hand can be attributed to the steady improvements in commercial digital processing components such as analog-to-digital converters (ADCs), digital-to-analog converters (DACs), field-programmable-gate-arrays (FPGAs), and digital-signal-processors (DSPs), and on the other hand can also be attributed to the increasing needs for improved time, position, and energy resolution in nuclear physics experiments, which have spurred the rapid development of commercial off-the-shelf high speed, high resolution digitizers or spectrometers. Absent from conventional analog electronics, the capability to record fast decaying pulses from radiation detectors in digital readout electronics has profoundly benefited nuclear physics researchers since they now can perform detailed pulse processing for applications such as gamma-ray tracking and decay-event selection and reconstruction. In this talk, present state-of-the-art digital readout electronics and its applications in a variety of nuclear science fields will be discussed, and future directions in hardware development for digital electronics will also be outlined, all from the prospective of a commercial manufacturer of digital electronics.

Improving Bone Formation in a Rat Femur Segmental Defect by Controlling Bone Morphogenetic Protein-2 Release

DTIC Science & Technology

2011-04-01

tissue and polymer: mineralized tissue stained dark green, osteoid and collagen bright red, soft tissue pink to light green, and erythrocytes bright...of bone, soft tissue , and polymer, high-resolution digital images were acquired at 1.25 · or 20 · . The area of interest comprising the bone defect...bone, soft tissue , and polymer (when present) within the defect were quantified using Metamorph software (Molecular Devices, Inc.) and were calculated

Measurement of Strain Distributions in Mouse Femora with 3D-Digital Speckle Pattern Interferometry

PubMed Central

Yang, Lianxiang; Zhang, Ping; Liu, Sheng; Samala, Praveen R; Su, Min; Yokota, Hiroki

2007-01-01

Bone is a mechanosensitive tissue that adapts its mass, architecture and mechanical properties to external loading. Appropriate mechanical loads offer an effective means to stimulate bone remodeling and prevent bone loss. A role of in situ strain in bone is considered essential in enhancement of bone formation, and establishing a quantitative relationship between 3D strain distributions and a rate of local bone formation is important. Digital speckle pattern interferometry (DSPI) can achieve whole-field, non-contacting measurements of microscopic deformation for high-resolution determination of 3D strain distributions. However, the current system does not allow us to derive accurate strain distributions because of complex surface contours inherent to biological samples. Through development of a custom-made piezoelectric loading device as well as a new DSPI-based force calibration system, we built an advanced DSPI system and integrated local contour information to deformation data. Using a mouse femur in response to a knee loading modality as a model system, we determined 3D strain distributions and discussed effectiveness and limitations of the described system. PMID:18670581

47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Digital Electronic Message Service Nodal... AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES 24 GHz Service and Digital Electronic Message Service § 101.503 Digital Electronic Message Service Nodal Stations. 10.6 GHz DEMS Nodal Stations may be...

Novel digital imaging techniques to assess the outcome in oral rehabilitation with dental implants: a narrative review.

PubMed

Benic, Goran I; Elmasry, Moustafa; Hämmerle, Christoph H F

2015-09-01

To examine the literature on novel digital imaging techniques for the assessment of outcomes in oral rehabilitation with dental implants. An electronic search of Medline and Embase databases including studies published prior to 28th December 2014 was performed and supplemented by a manual search. A synthesis of the publications was presented describing the use of computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography, optical scanning, spectrophotometry or optical coherence tomography (OCT) related to the outcome measures in implant therapy. Most of the digital imaging techniques have not yet sufficiently been validated to be used for outcome measures in implant dentistry. In clinical research, cone beam CT (CBCT) is increasingly being used for 3D assessment of bone and soft tissue following augmentation procedures and implant placement. Currently, there are no effective methods for the reduction of artifacts around implants in CBCT. Optical scanning is being used for the 3D assessment of changes in the soft tissue contour. The combination of optical scan with pre-operative CBCT allows the determination of the implant position and its spatial relation to anatomical structures. Spectrophotometry is the method most commonly used to objectively assess the color match of reconstructions and peri-implant mucosa to natural dentition and gingiva. New optical imaging techniques may be considered possible approaches for monitoring peri-implant soft tissue health. MRI and ultrasonography appear promising non-ionizing radiation imaging modalities for the assessment of soft tissue and bone defect morphologies. Optical scanners and OCT may represent efficient clinical methods for accurate assessment of the misfit between the reconstructions and the implants. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Digital Video and the Internet: A Powerful Combination.

ERIC Educational Resources Information Center

Barron, Ann E.; Orwig, Gary W.

1995-01-01

Provides an overview of digital video and outlines hardware and software necessary for interactive training on the World Wide Web and for videoconferences via the Internet. Lists sites providing additional information on digital video, on CU-SeeMe software, and on MBONE (Multicast BackBONE), a technology that permits real-time transmission of…

Dose and diagnostic image quality in digital tomosynthesis imaging of facial bones in pediatrics

NASA Astrophysics Data System (ADS)

King, J. M.; Hickling, S.; Elbakri, I. A.; Reed, M.; Wrogemann, J.

2011-03-01

The purpose of this study was to evaluate the use of digital tomosynthesis (DT) for pediatric facial bone imaging. We compared the eye lens dose and diagnostic image quality of DT facial bone exams relative to digital radiography (DR) and computed tomography (CT), and investigated whether we could modify our current DT imaging protocol to reduce patient dose while maintaining sufficient diagnostic image quality. We measured the dose to the eye lens for all three modalities using high-sensitivity thermoluminescent dosimeters (TLDs) and an anthropomorphic skull phantom. To assess the diagnostic image quality of DT compared to the corresponding DR and CT images, we performed an observer study where the visibility of anatomical structures in the DT phantom images were rated on a four-point scale. We then acquired DT images at lower doses and had radiologists indicate whether the visibility of each structure was adequate for diagnostic purposes. For typical facial bone exams, we measured eye lens doses of 0.1-0.4 mGy for DR, 0.3-3.7 mGy for DT, and 26 mGy for CT. In general, facial bone structures were visualized better with DT then DR, and the majority of structures were visualized well enough to avoid the need for CT. DT imaging provides high quality diagnostic images of the facial bones while delivering significantly lower doses to the lens of the eye compared to CT. In addition, we found that by adjusting the imaging parameters, the DT effective dose can be reduced by up to 50% while maintaining sufficient image quality.

The RUDY study: using digital technologies to enable a research partnership

PubMed Central

Teare, Harriet J A; Hogg, Joanna; Kaye, Jane; Luqmani, Raashid; Rush, Elaine; Turner, Alison; Watts, Laura; Williams, Melanie; Javaid, M Kassim

2017-01-01

Patients have extensive experience of their disease that can enhance the design and execution of research leading to significant innovations and efficiencies in the research process. The research community on the whole have been slow to adopt practices that enable patients to become active partners in research. Digital technologies are providing the means to do this more easily and so are increasingly being used to interact with patients and involve them in the design and execution of research. The RUDY (Rare UK Diseases of bone, joints and blood vessels) study’s pioneering approach applies a custom-developed electronic platform where patients can contribute information over time about their disease experience, lifestyle and clinical history. This is combined with a state-of-the-art Dynamic Consent model and a commitment to patient-driven research, to further our understanding of rare diseases. This paper describes the RUDY study and the benefits that have been gained from adopting this partnership approach to research. PMID:28443622

Comparison of ossification of demineralized bone, hydroxyapatite, Gelfoam, and bone wax in cranial defect repair.

PubMed

Papay, F A; Morales, L; Ahmed, O F; Neth, D; Reger, S; Zins, J

1996-09-01

Demineralized bone allografts in the repair of calvarial defects are compared with other common bone fillers. This study uses a video-digitizing radiographic analysis of calvarial defect ossification to determine calcification of bone defects and its relation to postoperative clinical examination and regional controls. The postoperative clinical results at 3 months demonstrated that bony healing was greatest in bur holes filled with demineralized bone and hydroxyapatite. Radiographic analysis demonstrated calcification of demineralized bone-filled defects compared to bone wax- and Gelfoam-filled regions. Hydroxyapatite granules are radiographically dense, thus not allowing accurate measurement of true bone healing. The results suggest that demineralized bone and hydroxyapatite provide better structural support via bone healing to defined calvarial defects than do Gelfoam and bone wax.

78 FR 11680 - Notice of Intent To Repatriate Cultural Items: Grand Rapids Public Museum, Grand Rapids, MI

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-19

..., shell, and bone, early trade beads.'' Digital images of these objects were reviewed by the Chickasaw... unassociated funerary objects is identified in the Grand Rapids Public Museum's records as ``animal bone and...

Soft Tissue Alterations in Esthetic Postextraction Sites: A 3-Dimensional Analysis.

PubMed

Chappuis, V; Engel, O; Shahim, K; Reyes, M; Katsaros, C; Buser, D

2015-09-01

Dimensional alterations of the facial soft and bone tissues following tooth extraction in the esthetic zone play an essential role to achieve successful outcomes in implant therapy. This prospective study is the first to investigate the interplay between the soft tissue dimensions and the underlying bone anatomy during an 8-wk healing period. The analysis is based on sequential 3-dimensional digital surface model superimpositions of the soft and bone tissues using digital impressions and cone beam computed tomography during an 8-wk healing period. Soft tissue thickness in thin and thick bone phenotypes at extraction was similar, averaging 0.7 mm and 0.8 mm, respectively. Interestingly, thin bone phenotypes revealed a 7-fold increase in soft tissue thickness after an 8-wk healing period, whereas in thick bone phenotypes, the soft tissue dimensions remained unchanged. The observed spontaneous soft tissue thickening in thin bone phenotypes resulted in a vertical soft tissue loss of only 1.6 mm, which concealed the underlying vertical bone resorption of 7.5 mm. Because of spontaneous soft tissue thickening, no significant differences were detected in the total tissue loss between thin and thick bone phenotypes at 2, 4, 6, and 8 wk. More than 51% of these dimensional alterations occurred within 2 wk of healing. Even though the observed spontaneous soft tissue thickening in thin bone phenotypes following tooth extraction conceals the pronounced underlying bone resorption pattern by masking the true bone deficiency, spontaneous soft tissue thickening offers advantages for subsequent bone regeneration and implant therapies in sites with high esthetic demand (Clinicaltrials.gov NCT02403700). © International & American Associations for Dental Research.

Optical 3D surface digitizing in forensic medicine: 3D documentation of skin and bone injuries.

PubMed

Thali, Michael J; Braun, Marcel; Dirnhofer, Richard

2003-11-26

Photography process reduces a three-dimensional (3D) wound to a two-dimensional level. If there is a need for a high-resolution 3D dataset of an object, it needs to be three-dimensionally scanned. No-contact optical 3D digitizing surface scanners can be used as a powerful tool for wound and injury-causing instrument analysis in trauma cases. The 3D skin wound and a bone injury documentation using the optical scanner Advanced TOpometric Sensor (ATOS II, GOM International, Switzerland) will be demonstrated using two illustrative cases. Using this 3D optical digitizing method the wounds (the virtual 3D computer model of the skin and the bone injuries) and the virtual 3D model of the injury-causing tool are graphically documented in 3D in real-life size and shape and can be rotated in the CAD program on the computer screen. In addition, the virtual 3D models of the bone injuries and tool can now be compared in a 3D CAD program against one another in virtual space, to see if there are matching areas. Further steps in forensic medicine will be a full 3D surface documentation of the human body and all the forensic relevant injuries using optical 3D scanners.

Fabrication and test of digital output interface devices for gas turbine electronic controls

NASA Technical Reports Server (NTRS)

Newirth, D. M.; Koenig, E. W.

1978-01-01

A program was conducted to develop an innovative digital output interface device, a digital effector with optical feedback of the fuel metering valve position, for future electronic controls for gas turbine engines. A digital effector (on-off solenoids driven directly by on-off signals from a digital electronic controller) with optical position feedback was fabricated, coupled with the fuel metering valve, and tested under simulated engine operating conditions. The testing indicated that a digital effector with optical position feedback is a suitable candidate, with proper development for future digital electronic gas turbine controls. The testing also identified several problem areas which would have to be overcome in a final production configuration.

Optical phase analysis in drilled cortical porcine bones using digital holographic interferometry

NASA Astrophysics Data System (ADS)

Tavera R., César G.; De la Torre I., Manuel H.; Flores M., J. Mauricio; Luna H., Juan M.; Briones R., Manuel de J.; Mendoza S., Fernando

2016-03-01

A study in porcine femoral bones with and without the presence of cortical drilling is presented. An out of plane digital holographic interferometer is used to retrieve the optical phase during the controlled compression tests. These tests try to simulate physiological deformations in postmortem healthy bones and compare their mechanical response with those having a cortical hole. The cortical drilling technique is widely used in medical procedures to fix plaques and metallic frames to a bone recovering from a fracture. Several materials and drilling techniques are used for this purpose. In this work we analyze the superficial variations of the bone when different drilling diameters are used. By means of the optical phase it is possible to recover the superficial deformation of the tissue during a controlled deformation with high resolution. This information could give a better understand about the micro structural variations of the bone instead of a bulk response. As proof of principle, several tests were performed to register the modes and ranges of the displacements for compressive loads. From these tests notorious differences are observed between both groups of bones, having less structural stiffness the drilled ones as expected. However, the bone's characteristic to absorb and adjust itself due the load is also highly affected according to the number of holes. Results from different kind of samples (undrilled and drilled) are presented and discussed in this work.

Bone scintigraphy elucidates different metabolic stages of melorheostosis.

PubMed

Izadyar, Sina; Gholamrezanezhad, Ali

2012-01-01

Melorheostosis is a rare benign non-hereditary sclerosing dysplasia involving the bone, often in a sclerotomal distribution. we report the case of a 27 years old lady with painful swelling of the left hand and forearm lasting for almost 15 years. The patient experienced aggravation of symptoms and limitation of motion during the past two months. Radiographic assessment revealed hyperostosis involving the left 3(rd) and 4(th) metacarpal bones and corresponding digits as well as the left ulna and distal humerus, with no soft tissue ossification. Angiographic and blood pool images of bone scintigraphy showed increased activity of mid-metacarpal region, corresponding to the sclerotom C-8. Delayed static views showed increased radiotracer uptake of the left 4(th) metacarpal bone and the corresponding digit as well as the left ulna and humerus, but no abnormal osteoblastic activity of the 3(rd) left metacarpal and digit. Histopathologic assessment confirmed the diagnosis of Melorheostosis. The case confirms that even in the same sclerotomal distribution, the multiple foci of involvement can present in different metabolic stages. In fact, the disease does not progress uniformly and different lesions can be seen in dissimilar stages of activity. Hence, metabolic imaging can be important to unmask which of the radiographically detected bony lesions are metabolically active and have the potential to be the source of current patient's symptoms and which of them are old, metabolically inactive and silent lesions, which are not clinically relevant to the patient's complaints.

Bone scintigraphy elucidates different metabolic stages of melorheostosis

PubMed Central

Izadyar, Sina; Gholamrezanezhad, Ali

2012-01-01

Melorheostosis is a rare benign non-hereditary sclerosing dysplasia involving the bone, often in a sclerotomal distribution. we report the case of a 27 years old lady with painful swelling of the left hand and forearm lasting for almost 15 years. The patient experienced aggravation of symptoms and limitation of motion during the past two months. Radiographic assessment revealed hyperostosis involving the left 3rd and 4th metacarpal bones and corresponding digits as well as the left ulna and distal humerus, with no soft tissue ossification. Angiographic and blood pool images of bone scintigraphy showed increased activity of mid-metacarpal region, corresponding to the sclerotom C-8. Delayed static views showed increased radiotracer uptake of the left 4th metacarpal bone and the corresponding digit as well as the left ulna and humerus, but no abnormal osteoblastic activity of the 3rd left metacarpal and digit. Histopathologic assessment confirmed the diagnosis of Melorheostosis. The case confirms that even in the same sclerotomal distribution, the multiple foci of involvement can present in different metabolic stages. In fact, the disease does not progress uniformly and different lesions can be seen in dissimilar stages of activity. Hence, metabolic imaging can be important to unmask which of the radiographically detected bony lesions are metabolically active and have the potential to be the source of current patient's symptoms and which of them are old, metabolically inactive and silent lesions, which are not clinically relevant to the patient's complaints. PMID:22514755

Accuracy assessment of 3D bone reconstructions using CT: an intro comparison.

PubMed

Lalone, Emily A; Willing, Ryan T; Shannon, Hannah L; King, Graham J W; Johnson, James A

2015-08-01

Computed tomography provides high contrast imaging of the joint anatomy and is used routinely to reconstruct 3D models of the osseous and cartilage geometry (CT arthrography) for use in the design of orthopedic implants, for computer assisted surgeries and computational dynamic and structural analysis. The objective of this study was to assess the accuracy of bone and cartilage surface model reconstructions by comparing reconstructed geometries with bone digitizations obtained using an optical tracking system. Bone surface digitizations obtained in this study determined the ground truth measure for the underlying geometry. We evaluated the use of a commercially available reconstruction technique using clinical CT scanning protocols using the elbow joint as an example of a surface with complex geometry. To assess the accuracies of the reconstructed models (8 fresh frozen cadaveric specimens) against the ground truth bony digitization-as defined by this study-proximity mapping was used to calculate residual error. The overall mean error was less than 0.4 mm in the cortical region and 0.3 mm in the subchondral region of the bone. Similarly creating 3D cartilage surface models from CT scans using air contrast had a mean error of less than 0.3 mm. Results from this study indicate that clinical CT scanning protocols and commonly used and commercially available reconstruction algorithms can create models which accurately represent the true geometry. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Digital hand atlas for web-based bone age assessment: system design and implementation

NASA Astrophysics Data System (ADS)

Cao, Fei; Huang, H. K.; Pietka, Ewa; Gilsanz, Vicente

2000-04-01

A frequently used assessment method of skeletal age is atlas matching by a radiological examination of a hand image against a small set of Greulich-Pyle patterns of normal standards. The method however can lead to significant deviation in age assessment, due to a variety of observers with different levels of training. The Greulich-Pyle atlas based on middle upper class white populations in the 1950s, is also not fully applicable for children of today, especially regarding the standard development in other racial groups. In this paper, we present our system design and initial implementation of a digital hand atlas and computer-aided diagnostic (CAD) system for Web-based bone age assessment. The digital atlas will remove the disadvantages of the currently out-of-date one and allow the bone age assessment to be computerized and done conveniently via Web. The system consists of a hand atlas database, a CAD module and a Java-based Web user interface. The atlas database is based on a large set of clinically normal hand images of diverse ethnic groups. The Java-based Web user interface allows users to interact with the hand image database form browsers. Users can use a Web browser to push a clinical hand image to the CAD server for a bone age assessment. Quantitative features on the examined image, which reflect the skeletal maturity, is then extracted and compared with patterns from the atlas database to assess the bone age.

47 CFR 32.2212 - Digital electronic switching.

Code of Federal Regulations, 2012 CFR

2012-10-01

... shall include the original cost of digital electronic switching equipment used to provide circuit... electronic switching equipment used to provide both circuit and packet switching shall be recorded in the... 47 Telecommunication 2 2012-10-01 2012-10-01 false Digital electronic switching. 32.2212 Section...

47 CFR 32.2212 - Digital electronic switching.

Code of Federal Regulations, 2014 CFR

2014-10-01

... shall include the original cost of digital electronic switching equipment used to provide circuit... electronic switching equipment used to provide both circuit and packet switching shall be recorded in the... 47 Telecommunication 2 2014-10-01 2014-10-01 false Digital electronic switching. 32.2212 Section...

47 CFR 32.2212 - Digital electronic switching.

Code of Federal Regulations, 2011 CFR

2011-10-01

... shall include the original cost of digital electronic switching equipment used to provide circuit... electronic switching equipment used to provide both circuit and packet switching shall be recorded in the... 47 Telecommunication 2 2011-10-01 2011-10-01 false Digital electronic switching. 32.2212 Section...

47 CFR 32.2212 - Digital electronic switching.

Code of Federal Regulations, 2010 CFR

2010-10-01

... shall include the original cost of digital electronic switching equipment used to provide circuit... electronic switching equipment used to provide both circuit and packet switching shall be recorded in the... 47 Telecommunication 2 2010-10-01 2010-10-01 false Digital electronic switching. 32.2212 Section...

47 CFR 32.2212 - Digital electronic switching.

Code of Federal Regulations, 2013 CFR

2013-10-01

... shall include the original cost of digital electronic switching equipment used to provide circuit... electronic switching equipment used to provide both circuit and packet switching shall be recorded in the... 47 Telecommunication 2 2013-10-01 2013-10-01 false Digital electronic switching. 32.2212 Section...

Is there a relation between local bone quality as assessed on panoramic radiographs and alveolar bone level?

PubMed

Nackaerts, Olivia; Gijbels, Frieda; Sanna, Anna-Maria; Jacobs, Reinhilde

2008-03-01

The aim was to explore the relation between radiographic bone quality on panoramic radiographs and relative alveolar bone level. Digital panoramic radiographs of 94 female patients were analysed (mean age, 44.5; range, 35-74). Radiographic density of the alveolar bone in the premolar region was determined using Agfa Musica software. Alveolar bone level and bone quality index (BQI) were also assessed. Relationships between bone density and BQI on one hand and the relative loss of alveolar bone level on the other were assessed. Mandibular bone density and loss of alveolar bone level were weakly but significantly negatively correlated for the lower premolar area (r = -.27). The BQI did not show a statistically significant relation to alveolar bone level. Radiographic mandibular bone density on panoramic radiographs shows a weak but significant relation to alveolar bone level, with more periodontal breakdown for less dense alveolar bone.

Automatic segmentation of bones from digital hand radiographs

NASA Astrophysics Data System (ADS)

Liu, Brent J.; Taira, Ricky K.; Shim, Hyeonjoon; Keaton, Patricia

1995-05-01

The purpose of this paper is to develop a robust and accurate method that automatically segments phalangeal and epiphyseal bones from digital pediatric hand radiographs exhibiting various stages of growth. The algorithm uses an object-oriented approach comprising several stages beginning with the most general objects to be segmented, such as the outline of the hand from background, and proceeding in a succession of stages to the most specific object, such as a specific phalangeal bone from a digit of the hand. Each stage carries custom operators unique to the needs of that specific stage which will aid in more accurate results. The method is further aided by a knowledge base where all model contours and other information such as age, race, and sex, are stored. Shape models, 1-D wrist profiles, as well as an interpretation tree are used to map model and data contour segments. Shape analysis is performed using an arc-length orientation transform. The method is tested on close to 340 phalangeal and epiphyseal objects to be segmented from 17 cases of pediatric hand images obtained from our clinical PACS. Patient age ranges from 2 - 16 years. A pediatric radiologist preliminarily assessed the results of the object contours and were found to be accurate to within 95% for cases with non-fused bones and to within 85% for cases with fused bones. With accurate and robust results, the method can be applied toward areas such as the determination of bone age, the development of a normal hand atlas, and the characterization of many congenital and acquired growth diseases. Furthermore, this method's architecture can be applied to other image segmentation problems.

Electromagnetic interference of bone-anchored hearing aids by cellular phones.

PubMed

Kompis, M; Negri, S; Häusler, R

2000-10-01

We report a case of electromagnetic interference between a bone-anchored hearing aid (BAHA) and a cellular phone. A 54-year-old women was successfully treated for severe mixed conductive and sensorineural hearing loss with a BAHA. Five years after implantation, the patient experienced a sudden feeling of dizziness, accompanied by a loud buzzing sound and by a sensation of head pressure while examining a digital mobile phone. During a subsequent experiment, the buzzing sound could be reproduced and was identified as electromagnetic interference between the BAHA and digital cellular phones. Seventeen adult BAHA users from our clinic participated in a subsequent survey. Of the 13 patients with some experience of digital cellular phones, 11 reported hearing annoying noises elicited by these devices. However, no other sensation, such as dizziness, was described. Owing to the increasing number of users of both hearing aids and cellular phones, the incidence of electromagnetic interference must be expected to increase as well. Although to date there is no evidence that such interference may be harmful or dangerous to users of conventional or bone-anchored hearing aids, unexpected interference can be a frightening experience.

A novel method for pair-matching using three-dimensional digital models of bone: mesh-to-mesh value comparison.

PubMed

Karell, Mara A; Langstaff, Helen K; Halazonetis, Demetrios J; Minghetti, Caterina; Frelat, Mélanie; Kranioti, Elena F

2016-09-01

The commingling of human remains often hinders forensic/physical anthropologists during the identification process, as there are limited methods to accurately sort these remains. This study investigates a new method for pair-matching, a common individualization technique, which uses digital three-dimensional models of bone: mesh-to-mesh value comparison (MVC). The MVC method digitally compares the entire three-dimensional geometry of two bones at once to produce a single value to indicate their similarity. Two different versions of this method, one manual and the other automated, were created and then tested for how well they accurately pair-matched humeri. Each version was assessed using sensitivity and specificity. The manual mesh-to-mesh value comparison method was 100 % sensitive and 100 % specific. The automated mesh-to-mesh value comparison method was 95 % sensitive and 60 % specific. Our results indicate that the mesh-to-mesh value comparison method overall is a powerful new tool for accurately pair-matching commingled skeletal elements, although the automated version still needs improvement.

Effect of scaling and root planing on alveolar bone as measured by subtraction radiography.

PubMed

Hwang, You-Jeong; Fien, Matthew Jonas; Lee, Sam-Sun; Kim, Tae-Il; Seol, Yang-Jo; Lee, Yong-Moo; Ku, Young; Rhyu, In-Chul; Chung, Chong-Pyoung; Han, Soo-Boo

2008-09-01

Scaling and root planing of diseased periodontal pockets is fundamental to the treatment of periodontal disease. Although various clinical parameters have been used to assess the efficacy of this therapy, radiographic analysis of changes in bone density following scaling and root planing has not been extensively researched. In this study, digital subtraction radiography was used to analyze changes that occurred in the periodontal hard tissues following scaling and root planing. Thirteen subjects with a total of 39 sites that presented with >3 mm of vertical bone loss were included in this study. Clinical examinations were performed and radiographs were taken prior to treatment and were repeated 6 months following scaling and root planing. Radiographic analysis was performed with computer-assisted radiographic evaluation software. Three regions of interest (ROI) were defined as the most coronal, middle, and apical portions of each defect. A fourth ROI was used for each site as a control region and was placed at a distant, untreated area. Statistical analysis was carried out to evaluate changes in the mean gray level at the coronal, middle, and apical region of each treated defect. Digital subtraction radiography revealed an increase in radiographic density in 101 of the 117 test regions (83.3%). A 256 gray level was used, and a value >128 was assumed to represent a density gain in the ROI. The average gray level increase was 18.65. Although the coronal, middle, and apical regions displayed increases in bone density throughout this study, the bone density of the apical ROI (gray level = 151.27 +/- 20.62) increased significantly more than the bone density of the coronal ROI (gray level = 139.19 +/- 21.78). A significant increase in bone density was seen in probing depths >5 mm compared to those <5 mm in depth. No significant difference was found with regard to bone-density changes surrounding single- versus multiple-rooted teeth. Scaling and root planing of diseased periodontal pockets can significantly increase radiographic alveolar bone density as demonstrated through the use of digital subtraction radiography.

Scanning electron microscopy of bone.

PubMed

Boyde, Alan

2012-01-01

This chapter described methods for Scanning Electron Microscopical imaging of bone and bone cells. Backscattered electron (BSE) imaging is by far the most useful in the bone field, followed by secondary electrons (SE) and the energy dispersive X-ray (EDX) analytical modes. This chapter considers preparing and imaging samples of unembedded bone having 3D detail in a 3D surface, topography-free, polished or micromilled, resin-embedded block surfaces, and resin casts of space in bone matrix. The chapter considers methods for fixation, drying, looking at undersides of bone cells, and coating. Maceration with alkaline bacterial pronase, hypochlorite, hydrogen peroxide, and sodium or potassium hydroxide to remove cells and unmineralised matrix is described in detail. Attention is given especially to methods for 3D BSE SEM imaging of bone samples and recommendations for the types of resin embedding of bone for BSE imaging are given. Correlated confocal and SEM imaging of PMMA-embedded bone requires the use of glycerol to coverslip. Cathodoluminescence (CL) mode SEM imaging is an alternative for visualising fluorescent mineralising front labels such as calcein and tetracyclines. Making spatial casts from PMMA or other resin embedded samples is an important use of this material. Correlation with other imaging means, including microradiography and microtomography is important. Shipping wet bone samples between labs is best done in glycerol. Environmental SEM (ESEM, controlled vacuum mode) is valuable in eliminating -"charging" problems which are common with complex, cancellous bone samples.

77 FR 68829 - Certain Electronic Digital Media Devices and Components Thereof; Notice of Request for Statements...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-16

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-796] Certain Electronic Digital Media... electronic digital media devices and components thereof imported by respondents Samsung Electronics Co, Ltd... Samsung. FOR FURTHER INFORMATION CONTACT: Cathy Chen, Office of the General Counsel, U.S. International...

Radiographical and clinical evaluation of critical size defects in rabbit calvaria filled with allograft and autograft: a pilot study

PubMed Central

Oporto V, Gonzalo H; Fuentes, Ramón; Borie, Eduardo; del Sol, Mariano; Orsi, Iara Augusta; Engelke, Wilfried

2014-01-01

Regeneration of resorbed edentulous sites can be induced by bone grafts from the subject himself and/or by the use of biomaterials. At present, there has been an extensive search for biomaterials that are evaluated by artificially creating one or more critical defects. The aim of this work was to clinically and radiographically analyze bone formation by the use of some biomaterials in artificially created defects in the parietal bone of rabbits. Six rabbits were used, creating defects of 8 mm in diameter in parietal bones. One defect was maintained with coagulum only, and in others, freeze-dried bone allograft (FDBA), autologous bone, and a combination of autologous bone with FDBA respectively, were added. Animals were sacrificed at 15-90 days with 2 weeks interval each, and calvaria were analyzed macroscopically, measuring by digital caliper the lack of filling at the surface of defects, identifying limits at anteroposterior and coronal view, realizing a digital photograph register of their external surfaces. This was subsequently evaluated radiographically by occlusal film radiography used to quantify its density through software. In conclusion, autologous bone showed the best behavior, clinically as well as radiographically. However, FDBA is a good option as an alternative to autologous bone as its behavior was slightly lower over time. The combination of autologous bone and FDBA in the same defect showed results considerably inferior to grafts used separately. Low radiopacity and clear limits were observed through time for the control coagulum filled defect. PMID:25126163

Endogenous Bone Regeneration Is Dependent Upon a Dynamic Oxygen Event

DTIC Science & Technology

2014-01-01

endosteum and nail epithelium (Fig. 2G ). By DPA 21 hypoxyprobe signaling is still apparent in osteoblasts in the newly formed trabecular bone, but to a...affiliated with cells that surround the vascular lumen (Fig. 2G ’). This signal within the distal tip of P3 expands at DPA 21, associated...vivo (Fig. 3G -I). Digit slices were cultured at 21% oxygen and 5% CO2. Bone formation was assessed using Alizarin red staining. Bone morphology is

Comparison of flight results with digital simulation for a digital electronic engine control in an F-15 airplane

NASA Technical Reports Server (NTRS)

Myers, L. P.; Burcham, F. W., Jr.

1983-01-01

Substantial benefits of a full authority digital electronic engine control on an air breathing engine were demonstrated repeatedly in simulation studies, ground engine tests, and engine altitude test facilities. A digital engine electronic control system showed improvements in efficiency, performance, and operation. An additional benefit of full authority digital controls is the capability of detecting and correcting failures and providing engine health diagnostics.

Development of the NASA Digital Astronaut Project Muscle Model

NASA Technical Reports Server (NTRS)

Lewandowski, Beth E.; Pennline, James A.; Thompson, W. K.; Humphreys, B. T.; Ryder, J. W.; Ploutz-Snyder, L. L.; Mulugeta, L.

2015-01-01

This abstract describes development work performed on the NASA Digital Astronaut Project Muscle Model. Muscle atrophy is a known physiological response to exposure to a low gravity environment. The DAP muscle model computationally predicts the change in muscle structure and function vs. time in a reduced gravity environment. The spaceflight muscle model can then be used in biomechanical models of exercise countermeasures and spaceflight tasks to: 1) develop site specific bone loading input to the DAP bone adaptation model over the course of a mission; 2) predict astronaut performance of spaceflight tasks; 3) inform effectiveness of new exercise countermeasures concepts.

Gradual digital lengthening with autologous bone graft and external fixation for correction of flail toe in a patient with Raynaud's disease.

PubMed

Lamm, Bradley M; Ades, Joe K

2009-01-01

Iatrogenic flail toe is a complication of hammertoe surgery that occurs when an overaggressive resection of the proximal phalanx occurs. This can cause both functional and cosmetic concerns for the patient. We present a case report of the correction of a flail second toe in a patient with Raynaud's disease. The correction was achieved by means of gradual soft tissue lengthening with external fixation and an interposition autologous bone graft digital arthrodesis. After 5 months, this 2-stage procedure lengthened, stabilized, and restored the function of the toe. 4.

Development of Bone Remodeling Model for Spaceflight Bone Physiology Analysis

NASA Technical Reports Server (NTRS)

Pennline, James A.; Werner, Christopher R.; Lewandowski, Beth; Thompson, Bill; Sibonga, Jean; Mulugeta, Lealem

2015-01-01

Current spaceflight exercise countermeasures do not eliminate bone loss. Astronauts lose bone mass at a rate of 1-2% a month (Lang et al. 2004, Buckey 2006, LeBlanc et al. 2007). This may lead to early onset osteoporosis and place the astronauts at greater risk of fracture later in their lives. NASA seeks to improve understanding of the mechanisms of bone remodeling and demineralization in 1g in order to appropriately quantify long term risks to astronauts and improve countermeasures. NASA's Digital Astronaut Project (DAP) is working with NASA's bone discipline to develop a validated computational model to augment research efforts aimed at achieving this goal.

Plasma cell quantification in bone marrow by computer-assisted image analysis.

PubMed

Went, P; Mayer, S; Oberholzer, M; Dirnhofer, S

2006-09-01

Minor and major criteria for the diagnosis of multiple meloma according to the definition of the WHO classification include different categories of the bone marrow plasma cell count: a shift from the 10-30% group to the > 30% group equals a shift from a minor to a major criterium, while the < 10% group does not contribute to the diagnosis. Plasma cell fraction in the bone marrow is therefore critical for the classification and optimal clinical management of patients with plasma cell dyscrasias. The aim of this study was (i) to establish a digital image analysis system able to quantify bone marrow plasma cells and (ii) to evaluate two quantification techniques in bone marrow trephines i.e. computer-assisted digital image analysis and conventional light-microscopic evaluation. The results were compared regarding inter-observer variation of the obtained results. Eighty-seven patients, 28 with multiple myeloma, 29 with monoclonal gammopathy of undetermined significance, and 30 with reactive plasmocytosis were included in the study. Plasma cells in H&E- and CD138-stained slides were quantified by two investigators using light-microscopic estimation and computer-assisted digital analysis. The sets of results were correlated with rank correlation coefficients. Patients were categorized according to WHO criteria addressing the plasma cell content of the bone marrow (group 1: 0-10%, group 2: 11-30%, group 3: > 30%), and the results compared by kappa statistics. The degree of agreement in CD138-stained slides was higher for results obtained using the computer-assisted image analysis system compared to light microscopic evaluation (corr.coeff. = 0.782), as was seen in the intra- (corr.coeff. = 0.960) and inter-individual results correlations (corr.coeff. = 0.899). Inter-observer agreement for categorized results (SM/PW: kappa 0.833) was in a high range. Computer-assisted image analysis demonstrated a higher reproducibility of bone marrow plasma cell quantification. This might be of critical importance for diagnosis, clinical management and prognostics when plasma cell numbers are low, which makes exact quantifications difficult.

Digital tooth-based superimposition method for assessment of alveolar bone levels on cone-beam computed tomography images.

PubMed

Romero-Delmastro, Alejandro; Kadioglu, Onur; Currier, G Frans; Cook, Tanner

2014-08-01

Cone-beam computed tomography images have been previously used for evaluation of alveolar bone levels around teeth before, during, and after orthodontic treatment. Protocols described in the literature have been vague, have used unstable landmarks, or have required several software programs, file conversions, or hand tracings, among other factors that could compromise the precision of the measurements. The purposes of this article are to describe a totally digital tooth-based superimposition method for the quantitative assessment of alveolar bone levels and to evaluate its reliability. Ultra cone-beam computed tomography images (0.1-mm reconstruction) from 10 subjects were obtained from the data pool of the University of Oklahoma; 80 premolars were measured twice by the same examiner and a third time by a second examiner to determine alveolar bone heights and thicknesses before and more than 6 months after orthodontic treatment using OsiriX (version 3.5.1; Pixeo, Geneva, Switzerland). Intraexaminer and interexaminer reliabilities were evaluated, and Dahlberg's formula was used to calculate the error of the measurements. Cross-sectional and longitudinal evaluations of alveolar bone levels were possible using a digital tooth-based superimposition method. The mean differences for buccal alveolar crest heights and thicknesses were below 0.10 mm for the same examiner and below 0.17 mm for all examiners. The ranges of errors for any measurement were between 0.02 and 0.23 mm for intraexaminer errors, and between 0.06 and 0.29 mm for interexaminer errors. This protocol can be used for cross-sectional or longitudinal assessment of alveolar bone levels with low interexaminer and intraexaminer errors, and it eliminates the use of less reliable or less stable landmarks and the need for multiple software programs and image printouts. Standardization of the methods for bone assessment in orthodontics is necessary; this method could be the answer to this need. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Measurement accuracy and perceived quality of imaging systems for the evaluation of periodontal structures.

PubMed

Baksi, B Güniz

2008-07-01

The aim of this study was to compare the subjective diagnostic quality of F-speed film images and original and enhanced storage phosphor plate (SPP) digital images for the visualization of periodontal ligament space (PLS) and periapical (PB) and alveolar crestal bone (CB) and to assess the accuracy of these image modalities for the measurement of alveolar bone levels. Standardized images of six dried mandibles were obtained with film and Digora SPPs. Six evaluators rated the visibility of anatomical structures using a three-point scale. Alveolar bone levels were measured from the coronal-most tip of the marginal bone to a reference point. Results were compared by using Friedman and Wilcoxon signed-ranks tests. The kappa (kappa) statistic was used to measure agreement among observers. The measurements were compared using repeated measures analysis of variance and Bonferroni tests (P = 0.05). A paired t test was used for comparison with true bone levels (P = 0.05). Enhanced SPP images were rated superior, followed by film and then the original SPP images, for the evaluation of anatomical structures. The value of kappa rose from fair to substantial after the enhancement of the SPP images. Film and enhanced SPP images provided alveolar bone lengths close to the true bone lengths. Enhancement of digital images provided better visibility and resulted in comparable accuracy to film images for the evaluation of periodontal structures.

Application of a digital data acquisition system for time of flight Positron annihilation-induced Auger Electron Spectroscopy

NASA Astrophysics Data System (ADS)

Gladen, R. W.; Chirayath, V. A.; McDonald, A. D.; Fairchild, A. J.; Chrysler, M. D.; Imam, S. K.; Koymen, A. R.; Weiss, A. H.

We describe herein a digital data acquisition system for a time-of-flight Positron annihilation-induced Auger Electron Spectrometer. This data acquisition system consists of a high-speed digitizer collecting signals induced by Auger electrons and annihilation gammas in a multi-channel plate electron detector and a BaF2 gamma detector, respectively. The time intervals between these two signals is used to determine the times of flight of the Auger electrons, which are analyzed by algorithms based on traditional nuclear electronics methods. Ultimately, this digital data acquisition system will be expanded to incorporate the first coincidence measurements of Auger electron and annihilation gamma energies.

21 CFR 1311.15 - Limitations on CSOS digital certificates.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Limitations on CSOS digital certificates. 1311.15... ELECTRONIC ORDERS AND PRESCRIPTIONS Obtaining and Using Digital Certificates for Electronic Orders § 1311.15 Limitations on CSOS digital certificates. (a) A CSOS digital certificate issued by the DEA Certification...

Dose in bone and tissue near bone-tissue interface from electron beam.

PubMed

Shiu, A S; Hogstrom, K R

1991-08-01

This work has quantitatively studied the variation of dose both within bone and in unit density tissue near bone-tissue interfaces. Dose upstream of a bone-tissue interface is increased because of an increase in the backscattered electrons from the bone. The magnitude of this effect was measured using a thin parallel-plate ionization chamber upstream of a polymethyl methacrylate (PMMA)-hard bone interface. The electron backscatter factor (EBF) increased rapidly with bone thickness until a full EBF was achieved. This occurred at approximately 3.5 mm at 2 MeV and 6 mm at 13.1 MeV. The full EBF at the interface ranged from approximately 1.018 at 13.1 MeV to 1.05 at 2 MeV. It was also observed that the EBF had a dependence on the energy spectrum at the interface. The penetration of the backscattered electrons in the upstream direction of PMMA was also measured. The dose penetration fell off rapidly in the upstream direction of the interface. Dose enhancement to unit density tissue in bone was measured for an electron beam by placing thermoluminescent dosimeters (TLDs) in a PMMA-bone-PMMA phantom. The maximum dose enhancement in bone was approximately 7% of the maximum dose in water. However, the pencil-beam algorithm of Hogstrom et al. predicted an increase of only 1%, primarily owing to the inverse-square correction. Film was also used to measure the dose enhancement in bone. The film plane was aligned either perpendicular or parallel to the central axis of the beam. The film data indicated that the maximum dose enhancement in bone was approximately 8% for the former film alignment (which was similarly predicted by the TLD measurements) and 13% for the latter film alignment. These results confirm that the X ray film is not suitable to be irritated "edge on" in an inhomogeneous phantom without making perturbation corrections resulting from the film acting as a long narrow inhomogeneous cavity within the bone. In addition, the results give the radiotherapist a basis for clinical judgment when electron beams are used to treat lesions behind bone or near bony structures. We feel these data enhance the ability to recognize the shortcomings of the current dose calculation algorithm used clinically.

Combining Digital Image Correlation and Acoustic Emission for Monitoring of the Strain Distribution until Yielding During Compression of Bovine Cancellous Bone

NASA Astrophysics Data System (ADS)

Tsirigotis, Athanasios; Deligianni, Despoina D.

2017-12-01

In this work, the surface heterogeneity in mechanical compressive strain of cancellous bone was investigated with digital image correlation (DIC). Moreover, the onset and progression of failure was studied by acoustic emission (AE). Cubic cancellous bone specimens, with side of 15 mm, were obtained from bovine femur and kept frozen at -20ºC until testing. Specimen strain was analyzed by measuring the change of distance between the platens (crosshead) and via an optical method, by following the strain evolution with a camera. Simultaneously, AE monitoring was performed. The experiments showed that compressive Young’s modulus determined by crosshead strain is underestimated at 23% in comparison to optically determined strain. However, surface strain fields defined by DIC displayed steep strain gradients, which can be attributed to cancellous bone porosity and inhomogeneity. The cumulative number of events for the total AE activity recorded from the sensors showed that the activity started at a mean load level of 36% of the maximum load and indicated the initiation of micro-cracking phenomena. Further experiments, determining 3D strain with μCT apart from surface strain, are necessary to clarify the issue of strain inhomogeneity in cancellous bone.

Comparison of radiograph-based texture analysis and bone mineral density with three-dimensional microarchitecture of trabecular bone.

PubMed

Ranjanomennahary, P; Ghalila, S Sevestre; Malouche, D; Marchadier, A; Rachidi, M; Benhamou, Cl; Chappard, C

2011-01-01

Hip fracture is a serious health problem and textural methods are being developed to assess bone quality. The authors aimed to perform textural analysis at femur on high-resolution digital radiographs compared to three-dimensional (3D) microarchitecture comparatively to bone mineral density. Sixteen cadaveric femurs were imaged with an x-ray device using a C-MOS sensor. One 17 mm square region of interest (ROI) was selected in the femoral head (FH) and one in the great trochanter (GT). Two-dimensional (2D) textural features from the co-occurrence matrices were extracted. Site-matched measurements of bone mineral density were performed. Inside each ROI, a 16 mm diameter core was extracted. Apparent density (Dapp) and bone volume proportion (BV/TV(Arch)) were measured from a defatted bone core using Archimedes' principle. Microcomputed tomography images of the entire length of the core were obtained (Skyscan 1072) at 19.8 microm of resolution and usual 3D morphometric parameters were computed on the binary volume after calibration from BV/TV(Arch). Then, bone surface/bone volume, trabecular thickness, trabecular separation, and trabecular number were obtained by direct methods without model assumption and the structure model index was calculated. In univariate analysis, the correlation coefficients between 2D textural features and 3D morphological parameters reached 0.83 at the FH and 0.79 at the GT. In multivariate canonical correlation analysis, coefficients of the first component reached 0.95 at the FH and 0.88 at the GT. Digital radiographs, widely available and economically viable, are an alternative method for evaluating bone microarchitectural structure.

21 CFR 1311.15 - Limitations on CSOS digital certificates.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Limitations on CSOS digital certificates. 1311.15... ELECTRONIC ORDERS AND PRESCRIPTIONS (Eff. 6-1-10) Obtaining and Using Digital Certificates for Electronic Orders § 1311.15 Limitations on CSOS digital certificates. (a) A CSOS digital certificate issued by the...

Autoradiographic method for quantitation of deposition and distribution of radiocalcium in bone

PubMed Central

Lawrence Riggs, B; Bassingthwaighte, James B.; Jowsey, Jenifer; Peter Pequegnat, E

2010-01-01

A method is described for quantitating autoradiographs of bone-seeking isotopes in microscopic sections of bone. Autoradiographs of bone sections containing 45Ca and internal calibration standards are automatically scanned with a microdensitometer. The digitized optical density output is stored on magnetic tape and is converted by computer to equivalent activity of 45Ca per gram of bone. The computer determines the total 45Ca uptake in the bone section and, on the basis of optical density and anatomic position, quantitatively divides the uptake into 4 components, each representing a separate physiologic process (bone formation, secondary mineralization, diffuse long-term exchange, and surface short-term exchange). The method is also applicable for quantitative analysis of microradiographs of bone sections for mineral content and density. PMID:5416906

[Development of a digital chest phantom for studies on energy subtraction techniques].

PubMed

Hayashi, Norio; Taniguchi, Anna; Noto, Kimiya; Shimosegawa, Masayuki; Ogura, Toshihiro; Doi, Kunio

2014-03-01

Digital chest phantoms continue to play a significant role in optimizing imaging parameters for chest X-ray examinations. The purpose of this study was to develop a digital chest phantom for studies on energy subtraction techniques under ideal conditions without image noise. Computed tomography (CT) images from the LIDC (Lung Image Database Consortium) were employed to develop a digital chest phantom. The method consisted of the following four steps: 1) segmentation of the lung and bone regions on CT images; 2) creation of simulated nodules; 3) transformation to attenuation coefficient maps from the segmented images; and 4) projection from attenuation coefficient maps. To evaluate the usefulness of digital chest phantoms, we determined the contrast of the simulated nodules in projection images of the digital chest phantom using high and low X-ray energies, soft tissue images obtained by energy subtraction, and "gold standard" images of the soft tissues. Using our method, the lung and bone regions were segmented on the original CT images. The contrast of simulated nodules in soft tissue images obtained by energy subtraction closely matched that obtained using the gold standard images. We thus conclude that it is possible to carry out simulation studies based on energy subtraction techniques using the created digital chest phantoms. Our method is potentially useful for performing simulation studies for optimizing the imaging parameters in chest X-ray examinations.

In vitro attenuation of impact shock in equine digits.

PubMed

Lanovaz, J L; Clayton, H M; Watson, L G

1998-09-01

This study was designed to test the impact characteristics of the equine digit in vitro with the objective of providing a better understanding of the role of the digital structures in the attenuation of impact shock. Uni-axial accelerometers were mounted on cadaver digits on the distolateral hoof wall, the proximolateral hoof wall, the dorsal surface of the second phalanx, and the mid-lateral first phalanx. The hoof-mounted accelerometers were aligned with the hoof tubules while the bone-mounted accelerometers were oriented along the longitudinal axis of the bone. Each digit was mounted in a test apparatus designed to simulate impact of the hoof with the ground during locomotion. The digits were subjected to 3 impact trials against a barrier at each of 3 vertical impact velocities that simulated a forward trotting velocity in the range of 2.67 to 4.46 m/s. The impact deceleration tended to increase with impact velocity. Attenuation of the impact shock by the digital tissues resulted in a reduction in impact decleration in the more proximal measuring locations. The interphalangeal joints appeared to play a larger role in amplitude attenuation than the hoof wall or the soft tissue structures within the hoof wall. The signal frequency data showed that the soft tissues within the hoof acted as a 'lowpass' filter, attenuating the higher deceleration frequencies. The hoof wall and the interphalangeal joints showed little frequency attenuation.

[Bone defect replacement under conditions of transosseous osteosynthesis and titanium nickelide implant application].

PubMed

Ir'ianov, Iu M; Ir'ianova, T Iu

2012-01-01

In the experiment conducted on 30 Wistar rats, the peculiarities of tibial bone defect replacement under conditions of transosseous osteosynthesis and implantation of titanium nickelide mesh structures were studied using the methods of scanning electron microscopy and x-ray electron probe microanalysis. It was demonstrated that implant osseointegration occured 7 days after surgery, and after 30 days the defect was replaced with bone tissue by the type of primary bone wound healing, thus the organotypical remodeling of regenerated bone took place.

Design reflowable digital book template

NASA Astrophysics Data System (ADS)

Prasetya, Didik Dwi; Widiyaningtyas, Triyanna; Arifin, M. Zainal; Wahyu Sakti G., I.

2017-09-01

Electronic books (e-books or digital books) increasingly in demand and continue to grow in the form of future books. One of the standard format electronic books that potential is EPUB (electronic publication) published by the International Digital Publishing Forum (IDPF). This digital book has major advantages are able to provide interactive and reflowable content, which are not found in another book format, such as PDF. Reflowable content allows the book can be accessed through a variety of reader device, like desktop and mobile with a fit and comfort view. However, because the generating process of an EPUB digital book is not as easy a PDF, so this format is less popular. Therefore, in order to help overcome the existing problems, this paper develops digital reflowable text book templates to support electronic learning, especially in Indonesia. This template can be used by anyone to produce a standard digital book quickly and easily without requiring additional specialized knowledge.

Perceptual approaches to finding features in data

NASA Astrophysics Data System (ADS)

Rogowitz, Bernice E.

2013-03-01

Electronic imaging applications hinge on the ability to discover features in data. For example, doctors examine diagnostic images for tumors, broken bones and changes in metabolic activity. Financial analysts explore visualizations of market data to find correlations, outliers and interaction effects. Seismologists look for signatures in geological data to tell them where to drill or where an earthquake may begin. These data are very diverse, including images, numbers, graphs, 3-D graphics, and text, and are growing exponentially, largely through the rise in automatic data collection technologies such as sensors and digital imaging. This paper explores important trends in the art and science of finding features in data, such as the tension between bottom-up and top-down processing, the semantics of features, and the integration of human- and algorithm-based approaches. This story is told from the perspective of the IS and T/SPIE Conference on Human Vision and Electronic Imaging (HVEI), which has fostered research at the intersection between human perception and the evolution of new technologies.

A pathologist-designed imaging system for anatomic pathology signout, teaching, and research.

PubMed

Schubert, E; Gross, W; Siderits, R H; Deckenbaugh, L; He, F; Becich, M J

1994-11-01

Pathology images are derived from gross surgical specimens, light microscopy, immunofluorescence, electron microscopy, molecular diagnostic gels, flow cytometry, image analysis data, and clinical laboratory data in graphic form. We have implemented a network of desktop personal computers (PCs) that allow us to easily capture, store, and retrieve gross and microscopic, anatomic, and research pathology images. System architecture involves multiple image acquisition and retrieval sites and a central file server for storage. The digitized images are conveyed via a local area network to and from image capture or display stations. Acquisition sites consist of a high-resolution camera connected to a frame grabber card in a 486-type personal computer, equipped with 16 MB (Table 1) RAM, a 1.05-gigabyte hard drive, and a 32-bit ethernet card for access to our anatomic pathology reporting system. We have designed a push-button workstation for acquiring and indexing images that does not significantly interfere with surgical pathology sign-out. Advantages of the system include the following: (1) Improving patient care: the availability of gross images at time of microscopic sign-out, verification of recurrence of malignancy from archived images, monitoring of bone marrow engraftment and immunosuppressive intervention after bone marrow/solid organ transplantation on repeat biopsies, and ability to seek instantaneous consultation with any pathologist on the network; (2) enhancing the teaching environment: building a digital surgical pathology atlas, improving the availability of images for conference support, and sharing cases across the network; (3) enhancing research: case study compilation, metastudy analysis, and availability of digitized images for quantitative analysis and permanent/reusable image records for archival study; and (4) other practical and economic considerations: storing case requisition images and hand-drawn diagrams deters the spread of gross room contaminants and results in considerable cost savings in photographic media for conferences, improved quality assurance by porting control stains across the network, and a multiplicity of other advantages that enhance image and information management in pathology.

Diagnostic workstation for digital hand atlas in bone age assessment

NASA Astrophysics Data System (ADS)

Cao, Fei; Huang, H. K.; Pietka, Ewa; Gilsanz, Vicente; Ominsky, Steven

1998-06-01

Bone age assessment by a radiological examination of a hand and wrist image is a procedure frequently performed in pediatric patients to evaluate growth disorders, determine growth potential in children and monitor therapy effects. The assessment method currently used in radiological diagnosis is based on atlas matching of the diagnosed hand image with the reference set of atlas patterns, which was developed in 1950s and is not fully applicable for children of today. We intent to implement a diagnostic workstation for creating a new reference set of clinically normal images which will serve as a digital atlas and can be used for a computer-assisted bone age assessment. In this paper, we present the initial data- collection and system setup phase of this five-year research program. We describe the system design, user interface implementation and software tool development for collection, visualization, management and processing of clinically normal hand and wrist images.

A study of the progression of damage in an axially loaded Branta leucopsis femur using X-ray computed tomography and digital image correlation.

PubMed

Mustansar, Zartasha; McDonald, Samuel A; Sellers, William Irvin; Manning, Phillip Lars; Lowe, Tristan; Withers, Philip J; Margetts, Lee

2017-01-01

This paper uses X-ray computed tomography to track the mechanical response of a vertebrate (Barnacle goose) long bone subjected to an axial compressive load, which is increased gradually until failure. A loading rig was mounted in an X-ray computed tomography system so that a time-lapse sequence of three-dimensional (3D) images of the bone's internal (cancellous or trabecular) structure could be recorded during loading. Five distinct types of deformation mechanism were observed in the cancellous part of the bone. These were (i) cracking, (ii) thinning (iii) tearing of cell walls and struts, (iv) notch formation, (v) necking and (vi) buckling. The results highlight that bone experiences brittle (notch formation and cracking), ductile (thinning, tearing and necking) and elastic (buckling) modes of deformation. Progressive deformation, leading to cracking was studied in detail using digital image correlation. The resulting strain maps were consistent with mechanisms occurring at a finer-length scale. This paper is the first to capture time-lapse 3D images of a whole long bone subject to loading until failure. The results serve as a unique reference for researchers interested in how bone responds to loading. For those using computer modelling, the study not only provides qualitative information for verification and validation of their simulations but also highlights that constitutive models for bone need to take into account a number of different deformation mechanisms.

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

Ranjanomennahary, P.; Ghalila, S. Sevestre; Malouche, D

Purpose: Hip fracture is a serious health problem and textural methods are being developed to assess bone quality. The authors aimed to perform textural analysis at femur on high-resolution digital radiographs compared to three-dimensional (3D) microarchitecture comparatively to bone mineral density. Methods: Sixteen cadaveric femurs were imaged with an x-ray device using a C-MOS sensor. One 17 mm square region of interest (ROI) was selected in the femoral head (FH) and one in the great trochanter (GT). Two-dimensional (2D) textural features from the co-occurrence matrices were extracted. Site-matched measurements of bone mineral density were performed. Inside each ROI, a 16more » mm diameter core was extracted. Apparent density (D{sub app}) and bone volume proportion (BV/TV{sub Arch}) were measured from a defatted bone core using Archimedes' principle. Microcomputed tomography images of the entire length of the core were obtained (Skyscan 1072) at 19.8 {mu}m of resolution and usual 3D morphometric parameters were computed on the binary volume after calibration from BV/TV{sub Arch}. Then, bone surface/bone volume, trabecular thickness, trabecular separation, and trabecular number were obtained by direct methods without model assumption and the structure model index was calculated. Results: In univariate analysis, the correlation coefficients between 2D textural features and 3D morphological parameters reached 0.83 at the FH and 0.79 at the GT. In multivariate canonical correlation analysis, coefficients of the first component reached 0.95 at the FH and 0.88 at the GT. Conclusions: Digital radiographs, widely available and economically viable, are an alternative method for evaluating bone microarchitectural structure.« less

27 CFR 73.3 - What terms must I know to understand this part?

Code of Federal Regulations, 2010 CFR

2010-04-01

... and/or actions are both unique to that individual and measurable. Digital signature. An electronic... verified. A signer creates a digital signature by using public-key encryption to transform a message digest of an electronic message. If a recipient of the digital signature has an electronic message, message...

27 CFR 73.3 - What terms must I know to understand this part?

Code of Federal Regulations, 2011 CFR

2011-04-01

... and/or actions are both unique to that individual and measurable. Digital signature. An electronic... verified. A signer creates a digital signature by using public-key encryption to transform a message digest of an electronic message. If a recipient of the digital signature has an electronic message, message...

21 CFR 1311.50 - Requirements for recipients of digitally signed orders.

Code of Federal Regulations, 2011 CFR

2011-04-01

... REQUIREMENTS FOR ELECTRONIC ORDERS AND PRESCRIPTIONS Obtaining and Using Digital Certificates for Electronic... digital certificate has not expired by checking the expiration date against the date the order was signed...

Haptics in forensics: the possibilities and advantages in using the haptic device for reconstruction approaches in forensic science.

PubMed

Buck, Ursula; Naether, Silvio; Braun, Marcel; Thali, Michael

2008-09-18

Non-invasive documentation methods such as surface scanning and radiological imaging are gaining in importance in the forensic field. These three-dimensional technologies provide digital 3D data, which are processed and handled in the computer. However, the sense of touch gets lost using the virtual approach. The haptic device enables the use of the sense of touch to handle and feel digital 3D data. The multifunctional application of a haptic device for forensic approaches is evaluated and illustrated in three different cases: the representation of bone fractures of the lower extremities, by traffic accidents, in a non-invasive manner; the comparison of bone injuries with the presumed injury-inflicting instrument; and in a gunshot case, the identification of the gun by the muzzle imprint, and the reconstruction of the holding position of the gun. The 3D models of the bones are generated from the Computed Tomography (CT) images. The 3D models of the exterior injuries, the injury-inflicting tools and the bone injuries, where a higher resolution is necessary, are created by the optical surface scan. The haptic device is used in combination with the software FreeForm Modelling Plus for touching the surface of the 3D models to feel the minute injuries and the surface of tools, to reposition displaced bone parts and to compare an injury-causing instrument with an injury. The repositioning of 3D models in a reconstruction is easier, faster and more precisely executed by means of using the sense of touch and with the user-friendly movement in the 3D space. For representation purposes, the fracture lines of bones are coloured. This work demonstrates that the haptic device is a suitable and efficient application in forensic science. The haptic device offers a new way in the handling of digital data in the virtual 3D space.

21 CFR 1311.35 - Number of CSOS digital certificates needed.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Number of CSOS digital certificates needed. 1311... FOR ELECTRONIC ORDERS AND PRESCRIPTIONS Obtaining and Using Digital Certificates for Electronic Orders § 1311.35 Number of CSOS digital certificates needed. A purchaser of Schedule I and II controlled...

21 CFR 1311.20 - Coordinators for CSOS digital certificate holders.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Coordinators for CSOS digital certificate holders... REQUIREMENTS FOR ELECTRONIC ORDERS AND PRESCRIPTIONS (Eff. 6-1-10) Obtaining and Using Digital Certificates for Electronic Orders § 1311.20 Coordinators for CSOS digital certificate holders. (a) Each registrant...

[Basic concept in computer assisted surgery].

PubMed

Merloz, Philippe; Wu, Hao

2006-03-01

To investigate application of medical digital imaging systems and computer technologies in orthopedics. The main computer-assisted surgery systems comprise the four following subcategories. (1) A collection and recording process for digital data on each patient, including preoperative images (CT scans, MRI, standard X-rays), intraoperative visualization (fluoroscopy, ultrasound), and intraoperative position and orientation of surgical instruments or bone sections (using 3D localises). Data merging based on the matching of preoperative imaging (CT scans, MRI, standard X-rays) and intraoperative visualization (anatomical landmarks, or bone surfaces digitized intraoperatively via 3D localiser; intraoperative ultrasound images processed for delineation of bone contours). (2) In cases where only intraoperative images are used for computer-assisted surgical navigation, the calibration of the intraoperative imaging system replaces the merged data system, which is then no longer necessary. (3) A system that provides aid in decision-making, so that the surgical approach is planned on basis of multimodal information: the interactive positioning of surgical instruments or bone sections transmitted via pre- or intraoperative images, display of elements to guide surgical navigation (direction, axis, orientation, length and diameter of a surgical instrument, impingement, etc. ). And (4) A system that monitors the surgical procedure, thereby ensuring that the optimal strategy defined at the preoperative stage is taken into account. It is possible that computer-assisted orthopedic surgery systems will enable surgeons to better assess the accuracy and reliability of the various operative techniques, an indispensable stage in the optimization of surgery.

Critical appraisal of volumetric-modulated arc therapy compared with electrons for the radiotherapy of cutaneous Kaposi's sarcoma of lower extremities with bone sparing.

PubMed

Nicolini, G; Abraham, S; Fogliata, A; Jordaan, A; Clivio, A; Vanetti, E; Cozzi, L

2013-03-01

To evaluate the use of volumetric-modulated arc therapy [VMAT, RapidArc® (RA); Varian Medical Systems, Palo Alto, CA] for the treatment of cutaneous Kaposi's sarcoma (KS) of lower extremities with adequate target coverage and high bone sparing, and to compare VMAT with electron beam therapy. 10 patients were planned with either RA or electron beams. The dose was prescribed to 30 Gy, 10 fractions, to mean the planning target volume (PTV), and significant maximum dose to bone was limited to 30 Gy. Plans were designed for 6-MV photon beams for RA and 6 MeV for electrons. Dose distributions were computed with AcurosXB® (Varian Medical Systems) for photons and with a Monte Carlo algorithm for electrons. V(90%) was 97.3±1.2 for RA plans and 78.2±2.6 for electrons; similarly, V(107%) was 2.5±2.2 and 37.7±3.4, respectively. RA met coverage criteria. Concerning bone sparing, D(2%) was 29.6±1.1 for RA and 31.0±2.4 for electrons. Although acceptable for bone involvement, pronounced target coverage violations were obtained for electron plans. Monitor units were similar for electrons and RA, although for the latter they increased when superior bone sparing was imposed. Delivery times were 12.1±4.0 min for electrons and 4.8±1.3 min for the most modulated RA plans. High plan quality was shown for KS in the lower extremities using VMAT, and this might simplify their management in comparison with the more conventional usage of electrons, particularly in institutes with limited staff resources and heavy workloads. VMAT is also dosimetrically extremely advantageous in a typology of treatments where electron beam therapy is mainly considered to be effective owing to the limited penetration of the beams.

Optical Fourier diffractometry applied to degraded bone structure recognition

NASA Astrophysics Data System (ADS)

Galas, Jacek; Godwod, Krzysztof; Szawdyn, Jacek; Sawicki, Andrzej

1993-09-01

Image processing and recognition methods are useful in many fields. This paper presents the hybrid optical and digital method applied to recognition of pathological changes in bones involved by metabolic bone diseases. The trabecular bone structure, registered by x ray on the photographic film, is analyzed in the new type of computer controlled diffractometer. The set of image parameters, extracted from diffractogram, is evaluated by statistical analysis. The synthetic image descriptors in discriminant space, constructed on the base of 3 training groups of images (control, osteoporosis, and osteomalacia groups) by discriminant analysis, allow us to recognize bone samples with degraded bone structure and to recognize the disease. About 89% of the images were classified correctly. This method after optimization process will be verified in medical investigations.

Production of accurate skeletal models of domestic animals using three-dimensional scanning and printing technology.

PubMed

Li, Fangzheng; Liu, Chunying; Song, Xuexiong; Huan, Yanjun; Gao, Shansong; Jiang, Zhongling

2018-01-01

Access to adequate anatomical specimens can be an important aspect in learning the anatomy of domestic animals. In this study, the authors utilized a structured light scanner and fused deposition modeling (FDM) printer to produce highly accurate animal skeletal models. First, various components of the bovine skeleton, including the femur, the fifth rib, and the sixth cervical (C6) vertebra were used to produce digital models. These were then used to produce 1:1 scale physical models with the FDM printer. The anatomical features of the digital models and three-dimensional (3D) printed models were then compared with those of the original skeletal specimens. The results of this study demonstrated that both digital and physical scale models of animal skeletal components could be rapidly produced using 3D printing technology. In terms of accuracy between models and original specimens, the standard deviations of the femur and the fifth rib measurements were 0.0351 and 0.0572, respectively. All of the features except the nutrient foramina on the original bone specimens could be identified in the digital and 3D printed models. Moreover, the 3D printed models could serve as a viable alternative to original bone specimens when used in anatomy education, as determined from student surveys. This study demonstrated an important example of reproducing bone models to be used in anatomy education and veterinary clinical training. Anat Sci Educ 11: 73-80. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

[Scanning electron microscopy of heat-damaged bone tissue].

PubMed

Harsanyl, L

1977-02-01

Parts of diaphyses of bones were exposed to high temperature of 200-1300 degrees C. Damage to the bone tissue caused by the heat was investigated. The scanning electron microscopic picture seems to be characteristic of the temperature applied. When the bones heated to the high temperature of 700 degrees C characteristic changes appear on the periostal surface, higher temperatura on the other hand causes damage to the compact bone tissue and can be observed on the fracture-surface. Author stresses the importance of this technique in the legal medicine and anthropology.

Electron Microscopy and Analytical X-ray Characterization of Compositional and Nanoscale Structural Changes in Fossil Bone

NASA Astrophysics Data System (ADS)

Boatman, Elizabeth Marie

The nanoscale structure of compact bone contains several features that are direct indicators of bulk tissue mechanical properties. Fossil bone tissues represent unique opportunities to understand the compact bone structure/property relationships from a deep time perspective, offering a possible array of new insights into bone diseases, biomimicry of composite materials, and basic knowledge of bioapatite composition and nanoscale bone structure. To date, most work with fossil bone has employed microscale techniques and has counter-indicated the survival of bioapatite and other nanoscale structural features. The obvious disconnect between the use of microscale techniques and the discernment of nanoscale structure has prompted this work. The goal of this study was to characterize the nanoscale constituents of fossil compact bone by applying a suite of diffraction, microscopy, and spectrometry techniques, representing the highest levels of spatial and energy resolution available today, and capable of complementary structural and compositional characterization from the micro- to the nanoscale. Fossil dinosaur and crocodile long bone specimens, as well as modern ratite and crocodile femurs, were acquired from the UC Museum of Paleontology. Preserved physiological features of significance were documented with scanning electron microscopy back-scattered imaging. Electron microprobe wavelength-dispersive X-ray spectroscopy (WDS) revealed fossil bone compositions enriched in fluorine with a complementary loss of oxygen. X-ray diffraction analyses demonstrated that all specimens were composed of apatite. Transmission electron microscopy (TEM) imaging revealed preserved nanocrystallinity in the fossil bones and electron diffraction studies further identified these nanocrystallites as apatite. Tomographic analyses of nanoscale elements imaged by TEM and small angle X-ray scattering were performed, with the results of each analysis further indicating that nanoscale structure is highly conserved in these four fossil specimens. Finally, the results of this study indicate that bioapatite can be preserved in even the most ancient vertebrate specimens, further supporting the idea that fossilization is a preservational process. This work also underlines the importance of using appropriately selected characterization and analytical techniques for the study of fossil bone, especially from the perspective of spatial resolution and the scale of the bone structural features in question.

Long-term outcomes of bone augmentation on soft and hard-tissue stability: a systematic review.

PubMed

Lutz, Rainer; Neukam, Friedrich W; Simion, Massimo; Schmitt, Christian M

2015-09-01

Peri-implant hard-tissue augmentation is a widely used clinical procedure. The present review aimed to analyse the current literature regarding medium- and long-term data concerning the stability of peri-implant tissues after hard-tissue augmentation prior or immediately with implant placement. An electronic literature search was performed using Medline (PubMed) databases detecting clinical studies focusing on hard- and soft-tissue stability around dental implants placed either in augmented alveolar ridges or simultaneously with peri-implant bone grafting. The search was limited to articles published between 1995 and December 2014, focusing on clinical studies with a prospective study design assessing peri-implant bone and soft tissue stability over time with a minimum follow-up of 12 months. Recent publications were also searched manually to find any relevant studies that might have been missed using the search criteria noted above. Thirty-seven articles met the inclusion criteria and were included in this systematic review. Since the outcome measures and methods, as well as types of grafts and implants used were so heterogeneous, the performance of meta-analysis was impossible. The highest level of evidence was achieved by randomized clinical trials. Different hard-tissue augmentation procedures seem to show stable peri-implant tissues, although, up to now, long-term stability of the augmented buccal bone is assessed by only few studies. Further research should concentrate on combining three-dimensional radiographic data with non-invasive methods as digital surface measuring techniques or ultrasound evaluation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

21 CFR 1311.35 - Number of CSOS digital certificates needed.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Number of CSOS digital certificates needed. 1311... FOR ELECTRONIC ORDERS AND PRESCRIPTIONS (Eff. 6-1-10) Obtaining and Using Digital Certificates for Electronic Orders § 1311.35 Number of CSOS digital certificates needed. A purchaser of Schedule I and II...

21 CFR 1311.10 - Eligibility to obtain a CSOS digital certificate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Eligibility to obtain a CSOS digital certificate... REQUIREMENTS FOR ELECTRONIC ORDERS AND PRESCRIPTIONS (Eff. 6-1-10) Obtaining and Using Digital Certificates for Electronic Orders § 1311.10 Eligibility to obtain a CSOS digital certificate. The following persons are...

21 CFR 1311.40 - Renewal of CSOS digital certificates.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Renewal of CSOS digital certificates. 1311.40... ELECTRONIC ORDERS AND PRESCRIPTIONS (Eff. 6-1-10) Obtaining and Using Digital Certificates for Electronic Orders § 1311.40 Renewal of CSOS digital certificates. (a) A CSOS certificate holder must generate a new...

21 CFR 1311.25 - Requirements for obtaining a CSOS digital certificate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Requirements for obtaining a CSOS digital... REQUIREMENTS FOR ELECTRONIC ORDERS AND PRESCRIPTIONS (Eff. 6-1-10) Obtaining and Using Digital Certificates for Electronic Orders § 1311.25 Requirements for obtaining a CSOS digital certificate. (a) To obtain a...

An image-based skeletal dosimetry model for the ICRP reference adult female—internal electron sources

NASA Astrophysics Data System (ADS)

O'Reilly, Shannon E.; DeWeese, Lindsay S.; Maynard, Matthew R.; Rajon, Didier A.; Wayson, Michael B.; Marshall, Emily L.; Bolch, Wesley E.

2016-12-01

An image-based skeletal dosimetry model for internal electron sources was created for the ICRP-defined reference adult female. Many previous skeletal dosimetry models, which are still employed in commonly used internal dosimetry software, do not properly account for electron escape from trabecular spongiosa, electron cross-fire from cortical bone, and the impact of marrow cellularity on active marrow self-irradiation. Furthermore, these existing models do not employ the current ICRP definition of a 50 µm bone endosteum (or shallow marrow). Each of these limitations was addressed in the present study. Electron transport was completed to determine specific absorbed fractions to both active and shallow marrow of the skeletal regions of the University of Florida reference adult female. The skeletal macrostructure and microstructure were modeled separately. The bone macrostructure was based on the whole-body hybrid computational phantom of the UF series of reference models, while the bone microstructure was derived from microCT images of skeletal region samples taken from a 45 years-old female cadaver. The active and shallow marrow are typically adopted as surrogate tissue regions for the hematopoietic stem cells and osteoprogenitor cells, respectively. Source tissues included active marrow, inactive marrow, trabecular bone volume, trabecular bone surfaces, cortical bone volume, and cortical bone surfaces. Marrow cellularity was varied from 10 to 100 percent for active marrow self-irradiation. All other sources were run at the defined ICRP Publication 70 cellularity for each bone site. A total of 33 discrete electron energies, ranging from 1 keV to 10 MeV, were either simulated or analytically modeled. The method of combining skeletal macrostructure and microstructure absorbed fractions assessed using MCNPX electron transport was found to yield results similar to those determined with the PIRT model applied to the UF adult male skeletal dosimetry model. Calculated skeletal averaged absorbed fractions for each source-target combination were found to follow similar trends of more recent dosimetry models (image-based models) but did not follow results from skeletal models based upon assumptions of an infinite expanse of trabecular spongiosa.

Local electronic structure and nanolevel hierarchical organization of bone tissue: theory and NEXAFS study

NASA Astrophysics Data System (ADS)

Pavlychev, A. A.; Avrunin, A. S.; Vinogradov, A. S.; Filatova, E. O.; Doctorov, A. A.; Krivosenko, Yu S.; Samoilenko, D. O.; Svirskiy, G. I.; Konashuk, A. S.; Rostov, D. A.

2016-12-01

Theoretical and experimental investigations of native bone are carried out to understand relationships between its hierarchical organization and local electronic and atomic structure of the mineralized phase. The 3D superlattice model of a coplanar assembly of the hydroxyapatite (HAP) nanocrystallites separated by the hydrated nanolayers is introduced to account the interplay of short-, long- and super-range order parameters in bone tissue. The model is applied to (i) predict and rationalize the HAP-to-bone spectral changes in the electronic structure and (ii) describe the mechanisms ensuring the link of the hierarchical organization with the electronic structure of the mineralized phase in bone. To check the predictions the near-edge x-ray absorption fine structure (NEXAFS) at the Ca 2p, P 2p and O 1s thresholds is measured for native bone and compared with NEXAFS for reference compounds. The NEXAFS analysis has demonstrated the essential hierarchy induced HAP-to-bone red shifts of the Ca and P 2p-to-valence transitions. The lowest O 1s excitation line at 532.2 eV in bone is assigned with superposition of core transitions in the hydroxide OH-(H2O) m anions, Ca2+(H2O) n cations, the carboxyl groups inside the collagen and [PO4]2- and [PO4]- anions with unsaturated P-O bonds.

The electron microscope appearance of the subchondral bone plate in the human femoral head in osteoarthritis and osteoporosis

PubMed Central

LI, BAOHUA; MARSHALL, DEBORAH; ROE, MARTIN; ASPDEN, RICHARD M.

1999-01-01

The subchondral bone plate supports the articular cartilage in diarthrodial joints. It has a significant mechanical function in transmitting loads from the cartilage into the underlying cancellous bone and has been implicated in the destruction of cartilage in osteoarthritis (OA) and its sparing in osteoporosis (OP), but little is known of its composition, structure or material properties. This study investigated the microscopic appearance and mineral composition of the subchondral bone plate in femoral heads from patients with OA or OP to determine how these correspond to changes in composition and stiffness found in other studies. Freeze-fractured full-depth samples of the subchondral bone plate from the femoral heads of patients with osteoarthritis, osteoporosis or a matched control group were examined using back scattered and secondary emission scanning electron microscopy. Other samples were embedded and polished and examined using back-scattered electron microscopy and electron probe microanalysis. The appearances of the samples from the normal and osteoporotic patients were very similar, with the subchondral bone plate overlayed by a layer of calcified cartilage. Osteoporotic samples presented a more uniform fracture surface and the relative thicknesses of the layers appeared to be different. In contrast, the OA bone plate appeared to be porous and have a much more textured surface. There were occasional sites of microtrabecular bone formation between the trabeculae of the underlying cancellous bone, which were not seen in the other groups, and more numerous osteoclast resorption pits. The calcified cartilage layer was almost absent and the bone plate was apparently thickened. The appearance of the osteoarthritic subchondral bone plate was, therefore, considerably different from both the normal and the osteoporotic, strongly indicative of abnormal cellular activity. PMID:10473297

Radiographic evaluation of marginal bone levels adjacent to parallel-screw cylinder machined-neck implants and rough-surfaced microthreaded implants using digitized panoramic radiographs.

PubMed

Nickenig, Hans-Joachim; Wichmann, Manfred; Schlegel, Karl Andreas; Nkenke, Emeka; Eitner, Stephan

2009-06-01

The purpose of this split-mouth study was to compare macro- and microstructure implant surfaces at the marginal bone level during a stress-free healing period and under functional loading. From January to February 2006, 133 implants (70 rough-surfaced microthreaded implants and 63 machined-neck implants) were inserted in the mandible of 34 patients with Kennedy Class I residual dentitions and followed until February 2008. The marginal bone level was radiographically determined, using digitized panoramic radiographs, at four time points: at implant placement (baseline level), after the healing period, after 6 months of functional loading, and at the end of follow-up. The median follow-up time was 1.9 (range: 1.9-2.1) years. The machined-neck group had a mean crestal bone loss of 0.5 mm (range: 0-2.3) after the healing period, 0.8 mm after 6 months (range: 0-2.4), and 1.1 mm (range: 0-3) at the end of follow-up. The rough-surfaced microthreaded implant group had a mean bone loss of 0.1 mm (range: -0.4-2) after the healing period, 0.4 mm (range: 0-2.1) after 6 months, and 0.5 mm (range: 0-2.1) at the end of follow-up. The two implant types showed significant differences in marginal bone levels (healing period: P=0.01; end of follow-up: P<0.01). Radiographic evaluation of marginal bone levels adjacent to machined-neck or rough-surfaced microthreaded implants showed that implants with the microthreaded design caused minimal changes in crestal bone levels during healing (stress-free) and under functional loading.

The Use of Backscattered Electron Imaging and Transmission Electron Microscopy to Assess Bone Architecture and Mineral Loci: Effect of Intermittent Slow-Release Sodium Fluoride Therapy

NASA Astrophysics Data System (ADS)

Zerwekh, Joseph E.; Bellotto, Dennis; Prostak, Kenneth S.; Hagler, Herbert K.; Pak, Charles Y. C.

1996-04-01

Backscattered electron imaging (BEI) and transmission electron microscopy (TEM) were used to examine the effects of treatment with intermittent slow-release sodium fluoride (SRNaF) and continuous calcium citrate on bone architecture and crystallinity. Examination was performed in nondecalcified biopsies obtained from patients following up to four years of therapy (placebo or SRNaF) and compared to pretreatment biopsies from each patient, as well as to bone from young, normal subjects. BEI images disclosed increased areas of recent bone formation following fluoride administration. There was no evidence of a mineralization defect in any biopsy and both cortical and trabecular architecture remained normal. TEM analysis demonstrated intrafibrillar platelike crystals and extrafibrillar needlelike crystals for both the pre- and post-treatment biopsies as well as for the bone from young normal subjects. There was no evidence of increased crystal size or of an increase in extrafibrillar mineral deposition. These observations suggest that intermittent SRNaF and continuous calcium therapy exerts an anabolic action on the skeleton not accompanied by a mineralization defect or an alteration of bone mineral deposition. The use of BEI and TEM holds promise for the study of the pathophysiology and treatment of metabolic bone diseases.

A digital volumetric tomography (DVT) study in the mandibular molar region for miniscrew placement during mixed dentition

PubMed Central

Bhattad, Mayur S.; Baliga, Sudhindra; Vibhute, Pavan

2015-01-01

OBJECTIVE: To assess bone thickness for miniscrew placement in the mandible during mixed dentition by using digital volumetric tomograph (DVT). MATERIAL AND METHODS: A total of 15 healthy patients aged 8-10 years old, with early exfoliated mandibular second deciduous molar, were included. DVT images of one quadrant of the mandible were obtained using Kodak extraoral imaging systems and analyzed by Kodak dental imaging software. The error of the method (EM) was calculated using Dahlberg's formula. Mean and standard deviation were calculated at 6 and 8 mm from the cementoenamel junction (CEJ).Paired t-test was used to analyze the measurements. RESULTS: Buccal cortical bone thickness, mesiodistal width and buccolingual bone depth at 6 mm were found to be 1.73 + 0.41, 2.15 + 0.49 and 13.18 + 1.22 mm, respectively; while at 8 mm measurements were 2.42 + 0.34, 2.48 + 0.33 and 13.65 + 1.25 mm, respectively. EM for buccal cortical bone thickness, mesiodistal width and buccolingual bone depth was 0.58, 0.40 and 0.48, respectively. The difference in measurement at 6 and 8 mm for buccal cortical plate thickness (P < 0.05) and buccolingual bone thickness (P < 0.05) was found to be significant, whereas for mesiodistal width it was insignificant (P > 0.05). CONCLUSION: Bone thickness measurement has shown promising evidence for safe placement of miniscrews in the mandible during mixed dentition. The use of miniscrew is the best alternative, even in younger patients. PMID:25992988

Participatory Culture Gets Schooled: Reflections on a Digital Literacies Course

ERIC Educational Resources Information Center

Avila, JuliAnna

2013-01-01

This paper is a course description of a Digital Literacies class offered to both undergraduate and graduate students at an American university. The purpose of this paper is: (1) to describe the pedagogical bones of this course, drawing upon theories of learning in a participatory culture, including a discussion of how, and where, the course fell…

Implementation and Integration of a Finite Element Model into the Bone Remodeling Model to Characterize Skeletal Loading

NASA Technical Reports Server (NTRS)

Werner, C. R.; Lewandowski, B.; Boppana, A.; Pennline, J. A.

2017-01-01

NASA's Digital Astronaut Project is developing a bone physiology model to predict changes in bone mineral density over the course of a space mission. The model intends to predict bone loss due to exposure in microgravity as well as predicting bone maintenance due to mechanical stimulus generated by exercise countermeasures. These predictions will be used to inform exercise device efficacy and to help design exercise protocols that will maintain bone mineral density during long exposures to microgravity during spaceflight. The mechanical stimulus and the stresses that are exhibited on the bone are important factors for bone remodeling. These stresses are dependent on the types of exercise that are performed and vary throughout the bone due to the geometry. A primary area of focus for bone health is the proximal femur. This location is critical in transmitting loads between the upper and lower body and have been known to be a critical failure point in older individuals with conditions like osteoporosis.

Deep erosions of the palmar aspect of the navicular bone diagnosed by standing magnetic resonance imaging.

PubMed

Sherlock, C; Mair, T; Blunden, T

2008-11-01

Erosion of the palmar (flexor) aspect of the navicular bone is difficult to diagnose with conventional imaging techniques. To review the clinical, magnetic resonance (MR) and pathological features of deep erosions of the palmar aspect of the navicular bone. Cases of deep erosions of the palmar aspect of the navicular bone, diagnosed by standing low field MR imaging, were selected. Clinical details, results of diagnostic procedures, MR features and pathological findings were reviewed. Deep erosions of the palmar aspect of the navicular bone were diagnosed in 16 mature horses, 6 of which were bilaterally lame. Sudden onset of lameness was recorded in 63%. Radiography prior to MR imaging showed equivocal changes in 7 horses. The MR features consisted of focal areas of intermediate or high signal intensity on T1-, T2*- and T2-weighted images and STIR images affecting the dorsal aspect of the deep digital flexor tendon, the fibrocartilage of the palmar aspect, subchondral compact bone and medulla of the navicular bone. On follow-up, 7/16 horses (44%) had been subjected to euthanasia and only one was being worked at its previous level. Erosions of the palmar aspect of the navicular bone were confirmed post mortem in 2 horses. Histologically, the lesions were characterised by localised degeneration of fibrocartilage with underlying focal osteonecrosis and fibroplasia. The adjacent deep digital flexor tendon showed fibril formation and fibrocartilaginous metaplasia. Deep erosions of the palmar aspect of the navicular bone are more easily diagnosed by standing low field MR imaging than by conventional radiography. The lesions involve degeneration of the palmar fibrocartilage with underlying osteonecrosis and fibroplasia affecting the subchondral compact bone and medulla, and carry a poor prognosis for return to performance. Diagnosis of shallow erosive lesions of the palmar fibrocartilage may allow therapeutic intervention earlier in the disease process, thereby preventing progression to deep erosive lesions.

17 CFR 23.202 - Daily trading records.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., instant messaging, chat rooms, electronic mail, mobile device, or other digital or electronic media. Such...; (ii) Moneys borrowed and moneys loaned; (iii) The daily calculation of the value of each outstanding... rooms, electronic mail, mobile device, or other digital or electronic media; (2) Reliable timing data...

17 CFR 23.202 - Daily trading records.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., instant messaging, chat rooms, electronic mail, mobile device, or other digital or electronic media. Such...; (ii) Moneys borrowed and moneys loaned; (iii) The daily calculation of the value of each outstanding... rooms, electronic mail, mobile device, or other digital or electronic media; (2) Reliable timing data...

Fractal dimension analysis of weight-bearing bones of rats during skeletal unloading

NASA Technical Reports Server (NTRS)

Pornprasertsuk, S.; Ludlow, J. B.; Webber, R. L.; Tyndall, D. A.; Sanhueza, A. I.; Yamauchi, M.

2001-01-01

Fractal analysis was used to quantify changes in trabecular bone induced through the use of a rat tail-suspension model to simulate microgravity-induced osteopenia. Fractal dimensions were estimated from digitized radiographs obtained from tail-suspended and ambulatory rats. Fifty 4-month-old male Sprague-Dawley rats were divided into groups of 24 ambulatory (control) and 26 suspended (test) animals. Rats of both groups were killed after periods of 1, 4, and 8 weeks. Femurs and tibiae were removed and radiographed with standard intraoral films and digitized using a flatbed scanner. Square regions of interest were cropped at proximal, middle, and distal areas of each bone. Fractal dimensions were estimated from slopes of regression lines fitted to circularly averaged plots of log power vs. log spatial frequency. The results showed that the computed fractal dimensions were significantly greater for images of trabecular bones from tail-suspended groups than for ambulatory groups (p < 0.01) at 1 week. Periods between 1 and 4 weeks likewise yielded significantly different estimates (p < 0.05), consistent with an increase in bone loss. In the tibiae, the proximal regions of the suspended group produced significantly greater fractal dimensions than other regions (p < 0.05), which suggests they were more susceptible to unloading. The data are consistent with other studies demonstrating osteopenia in microgravity environments and the regional response to skeletal unloading. Thus, fractal analysis could be a useful technique to evaluate the structural changes of bone.

Spatial resolution and measurement uncertainty of strains in bone and bone-cement interface using digital volume correlation.

PubMed

Zhu, Ming-Liang; Zhang, Qing-Hang; Lupton, Colin; Tong, Jie

2016-04-01

The measurement uncertainty of strains has been assessed in a bone analogue (sawbone), bovine trabecular bone and bone-cement interface specimens under zero load using the Digital Volume Correlation (DVC) method. The effects of sub-volume size, sample constraint and preload on the measured strain uncertainty have been examined. There is generally a trade-off between the measurement uncertainty and the spatial resolution. Suitable sub-volume sizes have been be selected based on a compromise between the measurement uncertainty and the spatial resolution of the cases considered. A ratio of sub-volume size to a microstructure characteristic (Tb.Sp) was introduced to reflect a suitable spatial resolution, and the measurement uncertainty associated was assessed. Specifically, ratios between 1.6 and 4 appear to give rise to standard deviations in the measured strains between 166 and 620 με in all the cases considered, which would seem to suffice for strain analysis in pre as well as post yield loading regimes. A microscale finite element (μFE) model was built from the CT images of the sawbone, and the results from the μFE model and a continuum FE model were compared with those from the DVC. The strain results were found to differ significantly between the two methods at tissue level, consistent in trend with the results found in human bones, indicating mainly a limitation of the current DVC method in mapping strains at this level. Copyright © 2015 Elsevier Ltd. All rights reserved.

A study of the progression of damage in an axially loaded Branta leucopsis femur using X-ray computed tomography and digital image correlation

PubMed Central

Manning, Phillip Lars; Lowe, Tristan; Withers, Philip J.

2017-01-01

This paper uses X-ray computed tomography to track the mechanical response of a vertebrate (Barnacle goose) long bone subjected to an axial compressive load, which is increased gradually until failure. A loading rig was mounted in an X-ray computed tomography system so that a time-lapse sequence of three-dimensional (3D) images of the bone’s internal (cancellous or trabecular) structure could be recorded during loading. Five distinct types of deformation mechanism were observed in the cancellous part of the bone. These were (i) cracking, (ii) thinning (iii) tearing of cell walls and struts, (iv) notch formation, (v) necking and (vi) buckling. The results highlight that bone experiences brittle (notch formation and cracking), ductile (thinning, tearing and necking) and elastic (buckling) modes of deformation. Progressive deformation, leading to cracking was studied in detail using digital image correlation. The resulting strain maps were consistent with mechanisms occurring at a finer-length scale. This paper is the first to capture time-lapse 3D images of a whole long bone subject to loading until failure. The results serve as a unique reference for researchers interested in how bone responds to loading. For those using computer modelling, the study not only provides qualitative information for verification and validation of their simulations but also highlights that constitutive models for bone need to take into account a number of different deformation mechanisms. PMID:28652932

Hierarchy effect on electronic structure and core-to-valence transitions in bone tissue: perspectives in medical nanodiagnostics of mineralized bone

NASA Astrophysics Data System (ADS)

Samoilenko, Dmitrii O.; Avrunin, Alexander S.; Pavlychev, Andrey A.

2017-06-01

Electronic structure and core-to-valence transitions in bone tissue are examined in the framework of the morphological 3DSL model that takes into account (i) structural and functional organization of the skeleton in the normal and pathological conditions and (ii) peculiarities of electron wave propagation in a three-dimensional superlattice of "black-nanocrystallites-in-muddy-waters". Our focus is on the HAP-to-bone red shifts of core-to-valence transitions near Ca and P 2p and O 1s edges in single-crystal hydroxyapatite (HAP) Ca10(PO4)6(OH)2. The origin of the HAP-to-bone shift is discussed and the extended comparative analysis of the experimental data is performed. The detected spectral shift is assigned with the effect of hierarchical organization of bone tissue. This hierarchy effect on the core-to-valence transition energies is regarded as a promising tool for medical imaging and perspective pathway for nanodiagnostics of mineralized bone. Contribution to the Topical Issue "Dynamics of Systems at the Nanoscale", edited by Andrey Solov'yov and Andrei Korol.

Digital radiographic evaluation of hand-wrist bone maturation and prediction of age in South Indian adolescents.

PubMed

Mohammed, Rezwana Begum; Reddy, M Asha Lata; Jain, Megha; Singh, Johar Rajvinder; Sanghvi, Praveen; Thetay, Anshuj Ajay Rao

2014-09-01

In the growing years, indicators of the level of maturational development of the individual provide the best means for evaluating biologic age and the associated timing of skeletal growth. The relative stage of maturity of a child may be determined by comparing the child's hand-wrist radiograph to the known standards of skeletal development. In this study, we assessed various levels of skeletal maturation and also identified the relationship between chronological age (CA) and maturation stage using the hand-wrist radiographs in adolescents of Indian origin. Three hundred and thirty hand-wrist digital radiographs of individuals aged 8 to 18 years were evaluated for skeletal maturity levels using Fishman's method. The data was analysed using the SPSS software package (version 12, SPSS Inc., Chicago, IL, USA). Regression analysis was performed for calculating bone age of both males and females. Spearman's rank-order correlation coefficients were estimated separately for males and females to assess the relation between CA and maturation level. An association between skeletal maturation indicator stages and CA (r = 0.82) was significant. Interestingly, female subjects were observed to be advanced in skeletal maturity compared to males. Regression equations were derived to calculate bone age in males, females and the whole sample. The results of this study showed significant association between hand-wrist skeletal maturation levels and CA. Digital radiographic assessment of hand-wrist skeletal maturation can be used as a better choice for predicting average bone age of an individual because of its simplicity, reliability and lesser radiation exposure.

The Integrity of Digital Information: Mechanics and Definitional Issues.

ERIC Educational Resources Information Center

Lynch, Clifford A.

1994-01-01

Considers issues regarding the migration of a system of literature into electronic formats. Highlights include integrity in an information distribution system; digest technology; tracings that permit detection of copied digital objects; verifying sources; digital signature technology and cryptography; electronic publishing; and intellectual…

77 FR 50726 - Software Requirement Specifications for Digital Computer Software and Complex Electronics Used in...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-22

... Computer Software and Complex Electronics Used in Safety Systems of Nuclear Power Plants AGENCY: Nuclear...-1209, ``Software Requirement Specifications for Digital Computer Software and Complex Electronics used... Electronics Engineers (ANSI/IEEE) Standard 830-1998, ``IEEE Recommended Practice for Software Requirements...

A comparison between digital radiography, computed tomography, and magnetic resonance in the detection of gunshot residues in burnt tissues and bone.

PubMed

Amadasi, Alberto; Borgonovo, Simone; Brandone, Alberto; Di Giancamillo, Mauro; Cattaneo, Cristina

2014-05-01

The radiological search for GSR is crucial in burnt material although it has been rarely tested. In this study, thirty-one bovine ribs were shot at near-contact range and burnt to calcination in an oven simulating a real combustion. Computed tomography (CT) and magnetic resonance (MR) were performed before and after carbonization and compared with former analyses with DR (digital radiography); thus comparing the assistance, the radiological methods can provide in the search for GSR in fresh and burnt bone. DR demonstrated the greatest ability in the detection of metallic residues, CT showed lower abilities, while MR showed a high sensitivity only in soft tissues. Thus, DR can be considered as the most sensitive method in the detection of GSR in charred bones, whereas CT and MR demonstrated much less reliability. Nonetheless, the MR ameliorates the analysis of gunshot wounds in other types of remains with large quantities of soft tissues. © 2013 American Academy of Forensic Sciences.

Critical appraisal of volumetric-modulated arc therapy compared with electrons for the radiotherapy of cutaneous Kaposi’s sarcoma of lower extremities with bone sparing

PubMed Central

Abraham, S; Fogliata, A; Jordaan, A; Clivio, A; Vanetti, E; Cozzi, L

2013-01-01

Objective: To evaluate the use of volumetric-modulated arc therapy [VMAT, RapidArc® (RA); Varian Medical Systems, Palo Alto, CA] for the treatment of cutaneous Kaposi’s sarcoma (KS) of lower extremities with adequate target coverage and high bone sparing, and to compare VMAT with electron beam therapy. Methods: 10 patients were planned with either RA or electron beams. The dose was prescribed to 30 Gy, 10 fractions, to mean the planning target volume (PTV), and significant maximum dose to bone was limited to 30 Gy. Plans were designed for 6-MV photon beams for RA and 6 MeV for electrons. Dose distributions were computed with AcurosXB® (Varian Medical Systems) for photons and with a Monte Carlo algorithm for electrons. Results: V90% was 97.3±1.2 for RA plans and 78.2±2.6 for electrons; similarly, V107% was 2.5±2.2 and 37.7±3.4, respectively. RA met coverage criteria. Concerning bone sparing, D2% was 29.6±1.1 for RA and 31.0±2.4 for electrons. Although acceptable for bone involvement, pronounced target coverage violations were obtained for electron plans. Monitor units were similar for electrons and RA, although for the latter they increased when superior bone sparing was imposed. Delivery times were 12.1±4.0 min for electrons and 4.8±1.3 min for the most modulated RA plans. Conclusion: High plan quality was shown for KS in the lower extremities using VMAT, and this might simplify their management in comparison with the more conventional usage of electrons, particularly in institutes with limited staff resources and heavy workloads. Advances in knowledge: VMAT is also dosimetrically extremely advantageous in a typology of treatments where electron beam therapy is mainly considered to be effective owing to the limited penetration of the beams. PMID:23392192

Acid-etching technique of non-decalcified bone samples for visualizing osteocyte-lacuno-canalicular network using scanning electron microscope.

PubMed

Lampi, Tiina; Dekker, Hannah; Ten Bruggenkate, Chris M; Schulten, Engelbert A J M; Mikkonen, Jopi J W; Koistinen, Arto; Kullaa, Arja M

2018-01-01

The aim of this study was to define the acid-etching technique for bone samples embedded in polymethyl metacrylate (PMMA) in order to visualize the osteocyte lacuno-canalicular network (LCN) for scanning electron microscopy (SEM). Human jaw bone tissue samples (N = 18) were collected from the study population consisting of patients having received dental implant surgery. After collection, the bone samples were fixed in 70% ethanol and non-decalcified samples embedded routinely into polymethyl metacrylate (PMMA). The PMMA embedded specimens were acid-etched in either 9 or 37% phosphoric acid (PA) and prepared for SEM for further analysis. PMMA embedded bone specimens acid-etched by 9% PA concentration accomplishes the most informative and favorable visualization of the LCN to be observed by SEM. Etching of PMMA embedded specimens is recommendable to start with 30 s or 40 s etching duration in order to find the proper etching duration for the samples examined. Visualizing osteocytes and LCN provides a tool to study bone structure that reflects changes in bone metabolism and diseases related to bone tissue. By proper etching protocol of non-decalcified and using scanning electron microscope it is possible to visualize the morphology of osteocytes and the network supporting vitality of bone tissue.

Fundamentals handbook of electrical and computer engineering. Volume 1 Circuits fields and electronics

NASA Astrophysics Data System (ADS)

Chang, S. S. L.

State of the art technology in circuits, fields, and electronics is discussed. The principles and applications of these technologies to industry, digital processing, microwave semiconductors, and computer-aided design are explained. Important concepts and methodologies in mathematics and physics are reviewed, and basic engineering sciences and associated design methods are dealt with, including: circuit theory and the design of magnetic circuits and active filter synthesis; digital signal processing, including FIR and IIR digital filter design; transmission lines, electromagnetic wave propagation and surface acoustic wave devices. Also considered are: electronics technologies, including power electronics, microwave semiconductors, GaAs devices, and magnetic bubble memories; digital circuits and logic design.

Electronic health record meets digital library: a new environment for achieving an old goal.

PubMed

Humphreys, B L

2000-01-01

Linking the electronic health record to the digital library is a Web-era reformulation of the long-standing informatics goal of seamless integration of automated clinical data and relevant knowledge-based information to support informed decisions. The spread of the Internet, the development of the World Wide Web, and converging format standards for electronic health data and digital publications make effective linking increasingly feasible. Some existing systems link electronic health data and knowledge-based information in limited settings or limited ways. Yet many challenging informatics research problems remain to be solved before flexible and seamless linking becomes a reality and before systems become capable of delivering the specific piece of information needed at the time and place a decision must be made. Connecting the electronic health record to the digital library also requires positive resolution of important policy issues, including health data privacy, government encouragement of high-speed communications, electronic intellectual property rights, and standards for health data and for digital libraries. Both the research problems and the policy issues should be important priorities for the field of medical informatics.

Electronic Health Record Meets Digital Library

PubMed Central

Humphreys, Betsy L.

2000-01-01

Linking the electronic health record to the digital library is a Web-era reformulation of the long-standing informatics goal of seamless integration of automated clinical data and relevant knowledge-based information to support informed decisions. The spread of the Internet, the development of the World Wide Web, and converging format standards for electronic health data and digital publications make effective linking increasingly feasible. Some existing systems link electronic health data and knowledge-based information in limited settings or limited ways. Yet many challenging informatics research problems remain to be solved before flexible and seamless linking becomes a reality and before systems become capable of delivering the specific piece of information needed at the time and place a decision must be made. Connecting the electronic health record to the digital library also requires positive resolution of important policy issues, including health data privacy, government envouragement of high-speed communications, electronic intellectual property rights, and standards for health data and for digital libraries. Both the research problems and the policy issues should be important priorities for the field of medical informatics. PMID:10984463

What Do Digital Books Mean for Libraries?

ERIC Educational Resources Information Center

Lynch, Clifford

2001-01-01

Discusses digital books, or electronic books, and their relationship to libraries and communication between authors and readers. Topics include the scholarly market, for academic libraries, versus the consumer market; textbooks versus novels; digitization of older books; marketing; costs; and electronic books versus printed books. (LRW)

Highly integrated digital electronic control: Digital flight control, aircraft model identification, and adaptive engine control

NASA Technical Reports Server (NTRS)

Baer-Riedhart, Jennifer L.; Landy, Robert J.

1987-01-01

The highly integrated digital electronic control (HIDEC) program at NASA Ames Research Center, Dryden Flight Research Facility is a multiphase flight research program to quantify the benefits of promising integrated control systems. McDonnell Aircraft Company is the prime contractor, with United Technologies Pratt and Whitney Aircraft, and Lear Siegler Incorporated as major subcontractors. The NASA F-15A testbed aircraft was modified by the HIDEC program by installing a digital electronic flight control system (DEFCS) and replacing the standard F100 (Arab 3) engines with F100 engine model derivative (EMD) engines equipped with digital electronic engine controls (DEEC), and integrating the DEEC's and DEFCS. The modified aircraft provides the capability for testing many integrated control modes involving the flight controls, engine controls, and inlet controls. This paper focuses on the first two phases of the HIDEC program, which are the digital flight control system/aircraft model identification (DEFCS/AMI) phase and the adaptive engine control system (ADECS) phase.

Effect of age-dependent bone electron density on the calculated dose distribution from kilovoltage and megavoltage photon and electron radiotherapy in paediatric MRI-only treatment planning.

PubMed

Zeinali-Rafsanjani, B; Faghihi, R; Mosleh-Shirazi, M A; Saeedi-Moghadam, M; Jalli, R; Sina, S

2018-01-01

MRI-only treatment planning (TP) can be advantageous in paediatric radiotherapy. However, electron density extraction is necessary for dose calculation. Normally, after bone segmentation, a bulk density is assigned. However, the variation of bone bulk density in patients makes the creation of pseudo CTs challenging. This study aims to assess the effects of bone density variations in children on radiation attenuation and dose calculation for MRI-only TP. Bone contents of <15-year-old children were calculated, and substituted in the Oak Ridge National Laboratory paediatric phantoms. The percentage depth dose and beam profile of 150 kVp and 6 MV photon and 6 MeV electron beams were then calculated using Xcom, MCNPX (Monte Carlo N-particle version X) and ORLN phantoms. Using 150 kVp X-rays, the difference in attenuation coefficient was almost 5% between an 11-year-old child and a newborn, and ~8% between an adult and a newborn. With megavoltage radiation, the differences were smaller but still important. For an 18 MV photon beam, the difference of radiation attenuation between an 11-year-old child and a newborn was 4% and ~7.4% between an adult and a newborn. For 6 MeV electrons, dose differences were observed up to the 2 cm depth. The percentage depth dose difference between 1 and 10-year-olds was 18.5%, and between 10 and 15-year-olds was 24%. The results suggest that for MRI-only TP of photon- or electron-beam radiotherapy, the bone densities of each age group should be defined separately for accurate dose calculation. Advances in knowledge: This study highlights the need for more age-specific determination of bone electron density for accurate dose calculations in paediatric MRI-only radiotherapy TP.

An Educational Laboratory for Digital Control and Rapid Prototyping of Power Electronic Circuits

ERIC Educational Resources Information Center

Choi, Sanghun; Saeedifard, M.

2012-01-01

This paper describes a new educational power electronics laboratory that was developed primarily to reinforce experimentally the fundamental concepts presented in a power electronics course. The developed laboratory combines theoretical design, simulation studies, digital control, fabrication, and verification of power-electronic circuits based on…

A Comparative Study on Diagnostic Accuracy of Colour Coded Digital Images, Direct Digital Images and Conventional Radiographs for Periapical Lesions – An In Vitro Study

PubMed Central

Mubeen; K.R., Vijayalakshmi; Bhuyan, Sanat Kumar; Panigrahi, Rajat G; Priyadarshini, Smita R; Misra, Satyaranjan; Singh, Chandravir

2014-01-01

Objectives: The identification and radiographic interpretation of periapical bone lesions is important for accurate diagnosis and treatment. The present study was undertaken to study the feasibility and diagnostic accuracy of colour coded digital radiographs in terms of presence and size of lesion and to compare the diagnostic accuracy of colour coded digital images with direct digital images and conventional radiographs for assessing periapical lesions. Materials and Methods: Sixty human dry cadaver hemimandibles were obtained and periapical lesions were created in first and second premolar teeth at the junction of cancellous and cortical bone using a micromotor handpiece and carbide burs of sizes 2, 4 and 6. After each successive use of round burs, a conventional, RVG and colour coded image was taken for each specimen. All the images were evaluated by three observers. The diagnostic accuracy for each bur and image mode was calculated statistically. Results: Our results showed good interobserver (kappa > 0.61) agreement for the different radiographic techniques and for the different bur sizes. Conventional Radiography outperformed Digital Radiography in diagnosing periapical lesions made with Size two bur. Both were equally diagnostic for lesions made with larger bur sizes. Colour coding method was least accurate among all the techniques. Conclusion: Conventional radiography traditionally forms the backbone in the diagnosis, treatment planning and follow-up of periapical lesions. Direct digital imaging is an efficient technique, in diagnostic sense. Colour coding of digital radiography was feasible but less accurate however, this imaging technique, like any other, needs to be studied continuously with the emphasis on safety of patients and diagnostic quality of images. PMID:25584318

Simulation of bone resorption-repair coupling in vitro.

PubMed

Jones, S J; Gray, C; Boyde, A

1994-10-01

In the normal adult human skeleton, new bone formation by osteoblasts restores the contours of bone surfaces following osteoclastic bone resorption, but the evidence for resorption-repair coupling remains circumstantial. To investigate whether sites of prior resorption, more than the surrounding unresorbed surface, attract osteoblasts or stimulate them to proliferate or make new matrix, we developed a simple in vitro system in which resorption-repair coupling occurs. Resorption pits were produced in mammalian dentine or bone slabs by culturing chick bone-derived cells on them for 2-3 days. The chick cells were swept off and the substrata reseeded with rat calvarial osteoblastic cells, which make bone nodules in vitro, for periods of up to 8 weeks. Cell positions and new bone formation were investigated by ordinary light microscopy, fluorescence and reflection confocal laser microscopy, and SEM, in stained and unstained samples. There was no evidence that the osteoblasts were especially attracted to, or influenced by, the sites of resorption in dentine or bone before cell confluence was reached. Bone formation was identified by light microscopy by the accumulation of matrix, staining with alizarin and calcein and by von Kossa's method, and confirmed by scanning electron microscopy (SEM) by using backscattered electron (BSE) and transmitted electron imaging of unembedded samples and BSE imaging of micro-milled embedded material. These new bone patches were located initially in the resorption pits. The model in vitro system may throw new light on the factors that control resorption-repair coupling in the mineralised tissues in vivo.

Structural and Ultrastructural Characteristics of Bone-Tendon Junction of the Calcaneal Tendon of Adult and Elderly Wistar Rats

PubMed Central

Cury, Diego Pulzatto; Dias, Fernando José; Miglino, Maria Angélica; Watanabe, Ii-sei

2016-01-01

Tendons are transition tissues that transfer the contractile forces generated by the muscles to the bones, allowing movement. The region where the tendon attaches to the bone is called bone-tendon junction or enthesis and may be classified as fibrous or fibrocartilaginous. This study aims to analyze the collagen fibers and the cells present in the bone-tendon junction using light microscopy and ultrastructural techniques as scanning electron microscopy and transmission electron microscopy. Forty male Wistar rats were used in the experiment, being 20 adult rats at 4 months-old and 20 elderly rats at 20 months-old. The hind limbs of the rats were removed, dissected and prepared to light microscopy, transmission electron microscopy and scanning electron microscopy. The aging process showed changes in the collagen fibrils, with a predominance of type III fibers in the elderly group, in addition to a decrease in the amount of the fibrocartilage cells, fewer and shorter cytoplasmic processes and a decreased synthetic capacity due to degradation of the organelles involved in synthesis. PMID:27078690

Structural and Ultrastructural Characteristics of Bone-Tendon Junction of the Calcaneal Tendon of Adult and Elderly Wistar Rats.

PubMed

Cury, Diego Pulzatto; Dias, Fernando José; Miglino, Maria Angélica; Watanabe, Ii-sei

2016-01-01

Tendons are transition tissues that transfer the contractile forces generated by the muscles to the bones, allowing movement. The region where the tendon attaches to the bone is called bone-tendon junction or enthesis and may be classified as fibrous or fibrocartilaginous. This study aims to analyze the collagen fibers and the cells present in the bone-tendon junction using light microscopy and ultrastructural techniques as scanning electron microscopy and transmission electron microscopy. Forty male Wistar rats were used in the experiment, being 20 adult rats at 4 months-old and 20 elderly rats at 20 months-old. The hind limbs of the rats were removed, dissected and prepared to light microscopy, transmission electron microscopy and scanning electron microscopy. The aging process showed changes in the collagen fibrils, with a predominance of type III fibers in the elderly group, in addition to a decrease in the amount of the fibrocartilage cells, fewer and shorter cytoplasmic processes and a decreased synthetic capacity due to degradation of the organelles involved in synthesis.

F-15 digital electronic engine control system description

NASA Technical Reports Server (NTRS)

Myers, L. P.

1984-01-01

A digital electronic engine control (DEEC) was developed for use on the F100-PW-100 turbofan engine. This control system has full authority control, capable of moving all the controlled variables over their full ranges. The digital computational electronics and fault detection and accomodation logic maintains safe engine operation. A hydromechanical backup control (BUC) is an integral part of the fuel metering unit and provides gas generator control at a reduced performance level in the event of an electronics failure. The DEEC's features, hardware, and major logic diagrams are described.

Performance of the Fully Digital FPGA-Based Front-End Electronics for the GALILEO Array

NASA Astrophysics Data System (ADS)

Barrientos, D.; Bellato, M.; Bazzacco, D.; Bortolato, D.; Cocconi, P.; Gadea, A.; González, V.; Gulmini, M.; Isocrate, R.; Mengoni, D.; Pullia, A.; Recchia, F.; Rosso, D.; Sanchis, E.; Toniolo, N.; Ur, C. A.; Valiente-Dobón, J. J.

2015-12-01

In this work we present the architecture and results of a fully digital Front End Electronics (FEE) read out system developed for the GALILEO array. The FEE system, developed in collaboration with the Advanced Gamma Tracking Array (AGATA) collaboration, is composed of three main blocks: preamplifiers, digitizers and preprocessing electronics. The slow control system contains a custom Linux driver, a dynamic library and a server implementing network services. This work presents the first results of the digital FEE system coupled with a GALILEO germanium detector, which has demonstrated the capability to achieve an energy resolution of 1.530/00 at an energy of 1.33 MeV, similar to the one obtained with a conventional analog system. While keeping a good performance in terms of energy resolution, digital electronics will allow to instrument the full GALILEO array with a versatile system with high integration and low power consumption and costs.

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

Madaric, Juraj, E-mail: jurmad@hotmail.com; Klepanec, Andrej; Mistrik, Martin

Induction of therapeutic angiogenesis by autologous bone marrow mononuclear cell transplantation has been identified as a potential new option in patients with advanced lower-limb ischemia. There is little evidence of the benefit of intra-arterial cell application in upper-limb critical ischemia. We describe a patient with upper-extremity critical limb ischemia with digital gangrene resulting from hypothenar hammer syndrome successfully treated by intra-arterial autologous bone marrow mononuclear cell transplantation.

Digital X-ray radiogrammetry and its sensitivity and specificity for the identification of rheumatoid arthritis-related cortical hand bone loss.

PubMed

Pfeil, Alexander; Haugeberg, Glenn; Renz, Diane M; Reinhardt, Lisa; Jung, Christian; Franz, Marcus; Wolf, Gunter; Böttcher, Joachim

2017-03-01

Digital X-ray radiogrammetry (DXR) is a computer-assisted diagnosis technique for quantifying cortical hand bone mineral density (BMD) as well as the metacarpal index (MCI) in the metacarpal bones from radiographs. The objective was to compare DXR-BMD and DXR-MCI between healthy individuals and patients with rheumatoid arthritis (RA) and verify the sensitivity and specificity of this technique for the identification of cortical hand bone loss as an additional diagnostic approach in RA. 618 patients were enrolled and divided into two groups: those with RA (n = 309) and a healthy control group (n = 309) as a reference database. DXR-BMD and the DXR-MCI were measured by DXR using hand radiographs. The severity of RA was evaluated by the modified Larsen score. Mean values for DXR-BMD and DXR-MCI in RA patients were significantly lower compared to healthy subjects (-20.7 and -21.1 %, respectively). Depending on the severity of RA-related joint damage, DXR-BMD revealed a significant reduction of -28.1 % and DXR-MCI -28.2 %, comparing score 1 and score 5 of the modified Larsen score. Both DXR-BMD and DXR-MCI had a high sensitivity (DXR-BMD 91 %, DXR-MCI 87 %) and a moderate specificity (DXR-BMD 47 %, DXR-MCI 49 %) to identify RA-related cortical hand bone loss. The DXR technique seems to be able to quantify RA-related periarticular bone loss as a characteristic feature in the course of RA. Consequently, periarticular osteoporosis seems to function as a reliable diagnostic approach comparable to erosions and joint space narrowing in the diagnosis of RA and as a surrogate marker for the progression of bone loss in RA.

Bone scintigraphy of the aged patient. 1. /sup 99m/Tc-polyphosphate bone scintigraphy (in Japanese)

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

Yamamoto, M.; Chiba, K.; Tanno, M.

Application and evaluation of a new bone-seeking radiopharmaceuticai, / sup 99m/Tc-polyphosphate are reported. Analysis of the image by digital color display data analyzer (Phosdac) was performed. The subjects of the study were cases at Tokyo Metropolitan Geriatric Hospital ranging from 63 to 85 years old with several kinds of bone diseases. Polyphosphate kits (Diagnostic Isotopes, Inc.) were used to prepare /sup 99m/Tc, and a Rho/gamma HP gamma-camera was used for scintigraphy. The images obtained were analyzed by Phosdac to obtain clear image of the bone system. In the final preparation, presence of approximately 30% of free /sup 99m/Tc was noticedmore » by paper chromatography. /sup 99m/Tc- polyphosphate was cleared from the blood with a half time of about 60 min. Urinary excretion proved to be 40 to 60% within 24 hrs. The bone system was visualized rather clearly with high accumulation of the label in the diseased region in spite of the fact that geriatric cases had marked general osteoporotic tendencies. In some cases, ribs were clearly visualized, and different information from that of x-ray was obtained by scanning images. Data processing by Phosdac increased diagnostic accuracy by enhancing the difference of the density of the image as well as eliminating the background caused by free /sup 99m/TcO/sub 4/. In conclusion, /sup 99m/Tc-polyphosphate was proved to be useful for bone scanning in geriatric cases. A digital color display data analyzer was successfully applied for the processing of the original data. (auth)« less

Current Total Ionizing Dose Results and Displacement Damage Results for Candidate Spacecraft Electronics for NASA

NASA Technical Reports Server (NTRS)

Cochran, Donna J.; Kniffin, Scott D.; LaBel, Kenneth A.; OBryan, Martha V.; Reed, Robert A.; Ladbury, Ray L.; Howard, James W., Jr.; Poivey, Christian; Buchner, Stephen P.; Marshall, Cheryl J.

2004-01-01

We present data on the vulnerability of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage. Devices tested include optoelectronics, digital, analog, linear bipolar devices, hybrid devices, Analog-to-Digital Converters (ADCs), and Digital-to-Analog Converters (DACS), among others.

Total Ionizing Dose Results and Displacement Damage Results for Candidate Spacecraft Electronics for NASA

NASA Technical Reports Server (NTRS)

Cochran, Donna J.; Kniffin, Scott D.; LaBel, Kenneth A.; OBryan, Martha V.; Reed, Robert A.; Ladbury, Ray L.; Howard, James W., Jr.; Poivey, Christian; Buchner, Stephen P.; Marshall, Cheryl J.

2003-01-01

We present data on the vulnerability of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage. Devices tested include optoelectronics, digital, analog, linear bipolar devices, hybrid devices, Analog-to-Digital Converters (ADCs), and Digital-to-Analog Converters (DACs), among others.

Does bone debris in anterior cruciate ligament reconstruction really matter? A cohort study of a protocol for bone debris debridement

PubMed Central

Imam, Mohamed A.; Abdelkafy, Ashraf; Dinah, Feroz; Adhikari, Ajeya

2015-01-01

Background: The purpose of the current study was to determine whether a systematic five-step protocol for debridement and evacuation of bone debris during anterior cruciate ligament reconstruction (ACLR) reduces the presence of such debris on post-operative radiographs. Methods: A five-step protocol for removal of bone debris during arthroscopic assisted ACLR was designed. It was applied to 60 patients undergoing ACLR (Group 1), and high-quality digital radiographs were taken post-operatively in each case to assess for the presence of intra-articular bone debris. A control group of 60 consecutive patients in whom no specific bone debris protocol was applied (Group 2) and their post-operative radiographs were also checked for the presence of intra-articular bone debris. Results: In Group 1, only 15% of post-operative radiographs showed residual bone debris, compared to 69% in Group 2 (p < 0.001). Conclusion: A five-step systematic protocol for bone debris removal during arthroscopic assisted ACLR resulted in a significant decrease in residual bone debris seen on high-quality post-operative radiographs. PMID:27163060

Biomechanical considerations for distraction of the monobloc, Le Fort III, and Le Fort I segments.

PubMed

Figueroa, Alvaro A; Polley, John W; Figueroa, Aaron D

2010-09-01

Distraction osteogenesis is effective for correction of severe maxillary and midface hypoplasia. The vectors controlling the segment to be moved must be planned. This requires knowledge of the physical characteristics of the osteotomized bone segment, including the location of the center of mass (free body) and the center of resistance (restrained body). The purpose of this study was to determine the center of mass of the osteotomized monobloc, Le Fort III, and Le Fort I bone segments. A dry human skull was used to sequentially isolate three bone segments: monobloc, Le Fort III, and Le Fort I. Each segment was suspended from three different points, and digital photographs were obtained from each suspension. The photographs were digitally superimposed. The center of mass was determined by calculating the intersection of the suspension lines. The center of mass for the monobloc segment was located at a point 43.5 percent of the total height from the occlusal plane to the superior edge of the frontal bone supraorbital osteotomy. For the Le Fort III, it was located 38 percent of the total height from the occlusal plane to the superior edge of the osteotomized base of the nasal bones. For the Le Fort I, it was 53 percent of the total height from the occlusal plane to the superior edge of the osteotomized maxillary bone. Knowledge of the location of the center of mass in the monobloc, Le Fort III, and Le Fort I segments provides a starting point for the clinician when planning vectors for advancement with distraction.

Physical Activity and Bone Density in Women

NASA Technical Reports Server (NTRS)

Bowley, Susan M.; Whalen, R. T.

2000-01-01

A mathematical model of bone density regulation as a function of the daily tissue "effective" stress has been derived. Using the model, the influence of daily activity in the form of a daily loading history has been related to bone density of the calcaneus. The theory incorporates a stress exponent m to account for differences in the importance of magnitude and number of load cycles experienced during daily activity. We have derived a parameter from the model, the "Bone Density Index" (BDI). We have developed a method of collecting daily habitual loading histories using an insole force sensor interfaced to a portable digital data logger carried in a fanny pack. Our goal for this study was to determine a stress exponent, m, relating GRFz history to Calcaneal Bone Mineral Density (CBMD).

Free form fabricated features on CoCr implants with and without hydroxyapatite coating in vivo: a comparative study of bone contact and bone growth induction.

PubMed

Grandfield, Kathryn; Palmquist, Anders; Gonçalves, Stéphane; Taylor, Andy; Taylor, Mark; Emanuelsson, Lena; Thomsen, Peter; Engqvist, Håkan

2011-04-01

The current study evaluates the in vivo response to free form fabricated cobalt chromium (CoCr) implants with and without hydroxyapatite (HA) plasma sprayed coatings. The free form fabrication method allowed for integration of complicated pyramidal surface structures on the cylindrical implant. Implants were press fit into the tibial metaphysis of nine New Zealand white rabbits. Animals were sacrificed and implants were removed and embedded. Histological analysis, histomorphometry and electron microscopy studies were performed. Focused ion beam was used to prepare thin sections for high-resolution transmission electron microscopy examination. The fabricated features allowed for effective bone in-growth and firm fixation after 6 weeks. Transmission electron microscopy investigations revealed intimate bone-implant integration at the nanometre scale for the HA coated samples. In addition, histomorphometry revealed a significantly higher bone contact on HA coated implants compared to native CoCr implants. It is concluded that free form fabrication in combination with HA coating improves the early fixation in bone under experimental conditions.

NASA researchers in gold control room during an F-15 HiDEC flight

NASA Technical Reports Server (NTRS)

1993-01-01

NASA researchers monitor equipment in the mission control Gold room at the Dryden Flight Research Center, Edwards, California, during a flight of an F-15 Highly Integrated Digital Electronic Control (HIDEC) research aircraft. The system was developed on the F-15 to investigate and demonstrate methods of obtaining optimum aircraft performance. The major elements of HIDEC were a Digital Electronic Flight Control System (DEFCS), a Digital Electronic Engine Control (DEEC), an on-board general purpose computer, and an integrated architecture to allow all components to 'talk to each other.' Unlike standard F-15s, which have a mechanical and analog electronic flight control system, the HIDEC F-15 also had a dual-channel, fail-safe digital flight control system programmed in Pascal. It was linked to the Military Standard 1553B and a H009 data bus which tied all the other electronic systems together.

NASA researchers in gold control room during an F-15 HiDEC flight, John Orme and Gerard Schkolnik

NASA Technical Reports Server (NTRS)

1993-01-01

NASA researchers Gerard Schkolnik (left) and John Orme monitor equipment in the control room at the Dryden Flight Research Center, Edwards, California, during a flight of an F-15 Highly Integrated Digital Electronic Control (HIDEC) research aircraft. The system was developed on the F-15 to investigate and demonstrate methods of obtaining optimum aircraft performance. The major elements of HIDEC were a Digital Electronic Flight Control System (DEFCS), a Digital Electronic Engine Control (DEEC), an on-board general purpose computer, and an integrated architecture to allow all components to 'talk to each other.' Unlike standard F-15s, which have a mechanical and analog electronic flight control system, the HIDEC F-15 also had a dual-channel, fail-safe digital flight control system programmed in Pascal. It was linked to the Military Standard 1553B and a H009 data bus which tied all the other electronic systems together.

Computerized tomography magnified bone windows are superior to standard soft tissue windows for accurate measurement of stone size: an in vitro and clinical study.

PubMed

Eisner, Brian H; Kambadakone, Avinash; Monga, Manoj; Anderson, James K; Thoreson, Andrew A; Lee, Hang; Dretler, Stephen P; Sahani, Dushyant V

2009-04-01

We determined the most accurate method of measuring urinary stones on computerized tomography. For the in vitro portion of the study 24 calculi, including 12 calcium oxalate monohydrate and 12 uric acid stones, that had been previously collected at our clinic were measured manually with hand calipers as the gold standard measurement. The calculi were then embedded into human kidney-sized potatoes and scanned using 64-slice multidetector computerized tomography. Computerized tomography measurements were performed at 4 window settings, including standard soft tissue windows (window width-320 and window length-50), standard bone windows (window width-1120 and window length-300), 5.13x magnified soft tissue windows and 5.13x magnified bone windows. Maximum stone dimensions were recorded. For the in vivo portion of the study 41 patients with distal ureteral stones who underwent noncontrast computerized tomography and subsequently spontaneously passed the stones were analyzed. All analyzed stones were 100% calcium oxalate monohydrate or mixed, calcium based stones. Stones were prospectively collected at the clinic and the largest diameter was measured with digital calipers as the gold standard. This was compared to computerized tomography measurements using 4.0x magnified soft tissue windows and 4.0x magnified bone windows. Statistical comparisons were performed using Pearson's correlation and paired t test. In the in vitro portion of the study the most accurate measurements were obtained using 5.13x magnified bone windows with a mean 0.13 mm difference from caliper measurement (p = 0.6). Measurements performed in the soft tissue window with and without magnification, and in the bone window without magnification were significantly different from hand caliper measurements (mean difference 1.2, 1.9 and 1.4 mm, p = 0.003, <0.001 and 0.0002, respectively). When comparing measurement errors between stones of different composition in vitro, the error for calcium oxalate calculi was significantly different from the gold standard for all methods except bone window settings with magnification. For uric acid calculi the measurement error was observed only in standard soft tissue window settings. In vivo 4.0x magnified bone windows was superior to 4.0x magnified soft tissue windows in measurement accuracy. Magnified bone window measurements were not statistically different from digital caliper measurements (mean underestimation vs digital caliper 0.3 mm, p = 0.4), while magnified soft tissue windows were statistically distinct (mean underestimation 1.4 mm, p = 0.001). In this study magnified bone windows were the most accurate method of stone measurements in vitro and in vivo. Therefore, we recommend the routine use of magnified bone windows for computerized tomography measurement of stones. In vitro the measurement error in calcium oxalate stones was greater than that in uric acid stones, suggesting that stone composition may be responsible for measurement inaccuracies.

Skeletal dosimetry in a voxel-based rat phantom for internal exposures to photons and electrons

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

Xie Tianwu; Han Dao; Liu Yang

2010-05-15

Purpose: The skeleton makes a significant contribution to the whole body absorbed dose evaluation of rats, since the bone marrow and bone surface in the skeleton express high radiosensitivity and are considered to be important dose-limiting tissues. The bone marrow can be categorized as red bone marrow (RBM) and yellow bone marrow (YBM). It is important to investigate the bone marrow in skeletal dosimetry. Methods: Cryosectional color images of the skeleton of a 156 g rat were segmented into mineral bone (including cortical bone and trabecular bone), RBM, and YBM. These three tissue types were identified at 40 different bonemore » sites and integrated into a previously developed voxel-based rat computational phantom. Photon and electron skeletal absorbed fractions were then calculated using the MCNPX Monte Carlo code. Results: Absorbed fraction (AF) and specific absorbed fraction (SAF) for mineral bone, RBM, and YBM at the 40 different bone sites were established for monoenergetic photon and electron sources placed in 18 organs and seven bone sites. Discrete photon energy was varied from 0.01 to 5.0 MeV in 21 discrete steps, while 21 discrete electron energies were studied, from 0.1 to 10.0 MeV. The trends and values found were consistent with the results of other researchers [M. G. Stabin, T. E. Peterson, G. E. Holburn, and M. A. Emmons, ''Voxel-based mouse and rat models for internal dose calculations,'' J. Nucl. Med. 47, 655-659 (2006)]. S-factors for the radionuclides {sup 169}Er, {sup 143}Pr, {sup 89}Sr, {sup 32}P, and {sup 90}Y, located in 18 organs and seven bone sites for the skeleton, were calculated and are provided in detail. Conclusions: For internal dose calculations, the AF data reveal that the mineral bone in the rat skeletal system is responsible for significant attenuation of gamma rays, especially at low energies. The photon SAF curves of RBM show that, for photon energies greater than 0.6 MeV, there is an increase in secondary photons emitted from the mineral bone as photon energy increases. The SAF values calculated in this study can also be used to determine the absorbed dose to the skeletal system of rats. The S-factors generated here will be useful in preclinical targeted radiotherapy experiments.« less

Spatial relationship between bone formation and mechanical stimulus within cortical bone: Combining 3D fluorochrome mapping and poroelastic finite element modelling.

PubMed

Carrieroa, A; Pereirab, A F; Wilson, A J; Castagno, S; Javaheri, B; Pitsillides, A A; Marenzana, M; Shefelbine, S J

2018-06-01

Bone is a dynamic tissue and adapts its architecture in response to biological and mechanical factors. Here we investigate how cortical bone formation is spatially controlled by the local mechanical environment in the murine tibia axial loading model (C57BL/6). We obtained 3D locations of new bone formation by performing 'slice and view' 3D fluorochrome mapping of the entire bone and compared these sites with the regions of high fluid velocity or strain energy density estimated using a finite element model, validated with ex-vivo bone surface strain map acquired ex-vivo using digital image correlation. For the comparison, 2D maps of the average bone formation and peak mechanical stimulus on the tibial endosteal and periosteal surface across the entire cortical surface were created. Results showed that bone formed on the periosteal and endosteal surface in regions of high fluid flow. Peak strain energy density predicted only the formation of bone periosteally. Understanding how the mechanical stimuli spatially relates with regions of cortical bone formation in response to loading will eventually guide loading regime therapies to maintain or restore bone mass in specific sites in skeletal pathologies.

ERM Ideas and Innovations: Digital Repository Management as ERM

ERIC Educational Resources Information Center

Pinkas, María M.; Lin, Na

2014-01-01

This article describes the application of electronic resources management (ERM) to digital repository management at the Health Sciences and Human Services Library at the University of Maryland, Baltimore. The authors discuss electronic resources management techniques, through the application of "Techniques for Electronic Management,"…

Recent Total Ionizing Dose Results and Displacement Damage Results for Candidate Spacecraft Electronics for NASA

NASA Technical Reports Server (NTRS)

Cochran, Donna J.; Buchner, Stephen P.; Irwin, Tim L.; LaBel, Kenneth A.; Marshall, Cheryl J.; Reed, Robert A.; Sanders, Anthony B.; Hawkins, Donald K.; Flanigan, Ryan J.; Cox, Stephen R.

2005-01-01

We present data on the vulnerability of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage. Devices tested include optoelectronics, digital, analog, linear bipolar devices, hybrid devices, Analog-to- Digital Converters (ADCs), and Digital-to-Analog Converters (DACs), among others. T

Cigarette smoking and alveolar bone in young adults: a study using digitized radiographs.

PubMed

Rosa, Guillermo M; Lucas, Gabriela Q; Lucas, Oscar N

2008-02-01

Evidence indicates that cigarette smoking is one of the most significant risk factors for periodontal diseases; however, there have been few radiographic prospective studies of alveolar bone in young populations. The purpose of this study was to evaluate the effect of smoking on alveolar bone in young adults. Eighty-one dental students (mean age: 20.5 years), considered not to have periodontitis according to clinical criteria, participated in this study. Forty-two subjects were smokers (mean consumption was 14.1 cigarettes/day for > or =2 years), and 39 subjects had never smoked. A parallel-arm prospective design was used. All subjects took part in a dental hygiene program (DHP) that included oral hygiene instructions, mechanical debridement, and polishing. The following clinical variables were measured before and after the DHP: plaque index (PI), gingival crevicular fluid (GCF) flow rate, gingival index (GI), probing depth, and clinical attachment level (CAL). Standardized posterior vertical bitewing radiographs were taken and digitized preexperimentally and on days 180, 365, and 545. The following analyses were performed: bone height measurement (BHM), computer-assisted densitometric image analysis (CADIA), and qualitative analysis of digital subtraction radiography (DSR). Repeated-measures multiple-way analysis of variance (ANOVA) was performed between the groups, and one-way ANOVA was performed within the groups. The mean PI and GI were significantly greater in the smokers (P <0.01). The mean GCF flow rate was significantly lower in the smokers (P <0.01). CAL and the number of sites with recession were significantly greater in the smokers (P <0.001). The BHM indicated a significantly lower mean alveolar bone height in the smokers (P <0.01). The smokers showed significantly lower CADIA values, which indicated a lower bone density on days 0 (P <0.05), 180, 365, and 545 (P <0.01). CADIA values decreased during the study in the smokers, with significant differences on day 545 (P <0.05). The smokers had a significantly higher mean percentage of sites that had decreased density, as assessed by DSR (P <0.001). In the smokers, the mean percentage of sites with decreased density, as assessed by DSR, had increased significantly by days 365 (P <0.05) and 545 (P <0.01). Smoking produces an adverse effect on clinical periodontal variables and alveolar bone height and density, acting as a potential risk factor for alveolar bone loss, even at an early age with low tobacco consumption. It is very important to inform young smokers about the risk of this habit in relation to periodontal health.

KM3NeT Digital Optical Module electronics

NASA Astrophysics Data System (ADS)

Real, Diego

2016-04-01

The KM3NeT collaboration is currently building of a neutrino telescope with a volume of several cubic kilometres at the bottom of the Mediterranean Sea. The telescope consists of a matrix of Digital Optical Modules that will detect the Cherenkov light originated by the interaction of the neutrinos in the proximity of the detector. This contribution describes the main components of the read-out electronics of the Digital Optical Module: the Power Board, which delivers all the power supply required by the Digital Optical Molule electronics; the Central Logic Board, the main core of the read-out system, hosting 31 Time to Digital Converters with 1 ns resolution and the White Rabbit protocol embedded in the Central Logic Board Field Programmable Gate Array; the Octopus boards, that transfer the Low Voltage Digital Signals from the PMT bases to the Central Logic Board and finally the PMT bases, in charge of converting the analogue signal produced in the 31 3" PMTs into a Low Voltage Digital Signal.

AVIRIS onboard data handling and control

NASA Technical Reports Server (NTRS)

Steinkraus, Ronald E.; Hickok, Roger W.

1987-01-01

The timing and flow of detector and ancillary data for the Airborne Visible/Infrared imaging spectrometer (AVIRIS) are controlled within the instrument by its digital electronics assembly. In addition to providing detector and signal chain timing, the digital electronics receives, formats, and rate-buffers digitized science data; collects and formats ancillary (calibration and engineering) data; and merges both into a single tape record. Overall AVIRIS data handling is effected by a combination of dedicated digital electronics to control instrument timing, image data flow, and data rate buffering and a microcomputer programmed to handle real-time control of instrument mechanisms and the coordinated preparation of ancillary data.

Auger electron spectroscopy for the determination of sex and age related Ca/P ratio at different bone sites

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

Balatsoukas, Ioannis; Kourkoumelis, Nikolaos; Tzaphlidou, Margaret

The Ca/P ratio of normal cortical and trabecular rat bone was measured by Auger electron spectroscopy (AES). Semiquantitative analysis was carried out using ratio techniques to draw conclusions on how age, sex and bone site affect the relative composition of calcium and phosphorus. Results show that Ca/P ratio is not sex dependent; quite the opposite, bone sites exhibit variations in elemental stoichiometry where femoral sections demonstrate higher Ca/P ratio than rear and front tibias. Age-related changes are more distinct for cortical bone in comparison with the trabecular bone. The latter's Ca/P ratio remains unaffected from all the parameters under study.more » This study confirms that AES is able to successfully quantify bone mineral main elements when certain critical points, related to the experimental conditions, are addressed effectively.« less

Digital preparation and osteology of the skull of Lesothosaurus diagnosticus (Ornithischia: Dinosauria).

PubMed

Porro, Laura B; Witmer, Lawrence M; Barrett, Paul M

2015-01-01

Several skulls of the ornithischian dinosaur Lesothosaurus diagnosticus (Lower Jurassic, southern Africa) are known, but all are either incomplete, deformed, or incompletely prepared. This has hampered attempts to provide a comprehensive description of skull osteology in this crucial early dinosaurian taxon. Using visualization software, computed tomographic scans of the Lesothosaurus syntypes were digitally segmented to remove matrix, and identify and separate individual cranial and mandibular bones, revealing new anatomical details such as sutural morphology and the presence of several previously undescribed elements. Together with visual inspection of exposed skull bones, these CT data enable a complete description of skull anatomy in this taxon. Comparisons with our new data suggest that two specimens previously identified as Lesothosaurus sp. (MNHN LES 17 and MNHN LES 18) probably represent additional individuals of Lesothosaurus diagnosticus.

Upgraded Readout Electronics for the ATLAS Liquid Argon Calorimeters at the High Luminosity LHC

NASA Astrophysics Data System (ADS)

Andeen, Timothy R.; ATLAS Liquid Argon Calorimeter Group

2012-12-01

The ATLAS liquid-argon calorimeters produce a total of 182,486 signals which are digitized and processed by the front-end and back-end electronics at every triggered event. In addition, the front-end electronics sum analog signals to provide coarsely grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. However, the pile-up background expected during the high luminosity phases of the LHC will be increased by factors of 3 to 7. An improved spatial granularity of the trigger primitives is therefore proposed in order to improve the identification performance for trigger signatures, like electrons or photons, at high background rejection rates. For the first upgrade phase in 2018, new Liquid Argon Trigger Digitizer Boards are being designed to receive higher granularity signals, digitize them on detector and send them via fast optical links to a new, off-detector digital processing system. The digital processing system applies digital filtering and identifies significant energy depositions. The refined trigger primitives are then transmitted to the first level trigger system to extract improved trigger signatures. The general concept of the upgraded liquid-argon calorimeter readout together with the various electronics components to be developed for such a complex system is presented. The research activities and architectural studies undertaken by the ATLAS Liquid Argon Calorimeter Group are described, particularly details of the on-going design of mixed-signal front-end electronics, of radiation tolerant optical-links, and of the high-speed off-detector digital processing system.

Digital image analysis agrees with visual estimates of adult bone marrow trephine biopsy cellularity.

PubMed

Hagiya, A S; Etman, A; Siddiqi, I N; Cen, S; Matcuk, G R; Brynes, R K; Salama, M E

2018-04-01

Evaluation of cellularity is an essential component of bone marrow trephine biopsy examination. The standard practice is to report the results as visual estimates (VE). Digital image analysis (DIA) offers the promise of more objective measurements of cellularity. Adult bone marrow trephine biopsy sections were assessed for cellularity by VE. Sections were scanned using an Aperio AT2 Scanscope and analyzed using a Cytonuclear (version 1.4) algorithm on halo software. Intraclass correlation (ICC) was used to assess relatedness between VE and DIA, and between MRI and DIA for a separate subset of patients. Trephine biopsy sections from a subset of patients with bone marrow biopsies uninvolved by malignancy were assessed for age-related changes. Interobserver VE agreement was good to excellent. The ICC value was 0.81 for VE and DIA, and 0.50 for MRI and DIA. Linearity studies showed no statistically significant trend for age-related changes in cellularity in our cohort (r = -.29, P = .06). Agreement was good between VE and DIA. It may be possible to use DIA or VE to measure cellularity in the appropriate clinical scenario. The limited sample size precludes similar determinations for MRI calculations. Further studies examining healthy donors are necessary before making definitive conclusions regarding age and cellularity. © 2017 John Wiley & Sons Ltd.

Fault tolerant programmable digital attitude control electronics study

NASA Technical Reports Server (NTRS)

Sorensen, A. A.

1974-01-01

The attitude control electronics mechanization study to develop a fault tolerant autonomous concept for a three axis system is reported. Programmable digital electronics are compared to general purpose digital computers. The requirements, constraints, and tradeoffs are discussed. It is concluded that: (1) general fault tolerance can be achieved relatively economically, (2) recovery times of less than one second can be obtained, (3) the number of faulty behavior patterns must be limited, and (4) adjoined processes are the best indicators of faulty operation.

The Effects of Bio-Lubricating Molecules on Flexor Tendon Reconstruction in A Canine Allograft Model In Vivo

PubMed Central

Zhao, Chunfeng; Wei, Zhuang; Kirk, Ramona L.; Thoreson, Andrew R.; Jay, Gregory D.; Moran, Steven L.; An, Kai-Nan; Amadio, Peter C.

2014-01-01

Background Using allograft is an attractive alternative for flexor tendon reconstruction because of the lack of donor morbidity, and better matching to the intrasynovial environment. The purpose of this study was to use biolubricant molecules to modify the graft surface to decrease adhesions and improve digit function. Methods 28 flexor digitorum profundus (FDP) tendons from the 2nd and 5th digits of 14 dogs were first lacerated and repaired to create a model with repair failure and scar digit for tendon reconstruction. Six weeks after the initial surgery, the tendons were reconstructed with FDP allograft tendons obtained from canine cadavers. One graft tendon in each dog was treated with saline as a control and the other was treated with gelatin, carbodiimide derivatized, hyaluronic acid and lubricin (cd-HA-Lubricin). Six weeks postoperatively, digit function, graft mechanics, and biology were analyzed. Results Allograft tendons treated with cd-HA-Lubricin had decreased adhesions at the proximal tendon/graft repair and within flexor sheath, improved digit function, and increased graft gliding ability. The treatment also reduced the strength at the distal tendon to bone repair, but the distal attachment rupture rate was similar for both graft types. Histology showed that viable cells migrated to the allograft, but these were limited to the tendon surface. Conclusion cd-HA-Lubricin treatment of tendon allograft improves digit functional outcomes after flexor tendon reconstruction. However, delayed bone-tendon healing should be a caution. Furthermore, the cell infiltration into the allograft tendons substance should be a target for future studies, to shorten the allograft self-regeneration period. PMID:24445876

Recent Radiation Damage and Single Event Effect Results for Candidate Spacecraft Electronics

NASA Technical Reports Server (NTRS)

OBryan, Martha V.; LaBel, Kenneth A.; Reed, Robert A.; Ladbury, Ray L.; Howard, James W., Jr.; Buchner, Stephen P.; Barth, Janet L.; Kniffen, Scott D.; Seidleck, Christina M.; Marshall, Cheryl J.;

Current Single Event Effects and Radiation Damage Results for Candidate Spacecraft Electronics

NASA Technical Reports Server (NTRS)

OBryan, Martha V.; LaBel, Kenneth A.; Reed, Robert A.; Ladbury, Ray L.; Howard, James W., Jr.; Kniffin, Scott D.; Poivey, Christian; Buchner, Stephen P.; Bings, John P.; Titus, Jeff L.

2002-01-01

We present data on the vulnerability of a variety of candidate spacecraft electronics to proton and heavy ion induced single event effects, total ionizing dose and proton-induced damage. Devices tested include optoelectronics, digital, analog, linear bipolar, hybrid devices, Analog-to-Digital Converters (ADCs), Digital-to-Analog Converters (DACs), and DC-DC converters, among others.

Analysis and design of digital output interface devices for gas turbine electronic controls

NASA Technical Reports Server (NTRS)

Newirth, D. M.; Koenig, E. W.

1976-01-01

A trade study was performed on twenty-one digital output interface schemes for gas turbine electronic controls to select the most promising scheme based on criteria of reliability, performance, cost, and sampling requirements. The most promising scheme, a digital effector with optical feedback of the fuel metering valve position, was designed.

7 CFR 1770.15 - Supplementary accounts required of all borrowers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Switching—Circuit. 2212.2 2212.2 Digital Electronic Switching—Packet. 2230.11 Central Office Transmission... Retirement Work in Progress. Current Liabilities 2232.1 2232.1 Circuit Equipment—Electronic. 2232.2 2232.2... Expense—Circuit. 6212.2 6212.2 Digital Electronic Switching Expense—Packet. 6230.11 Radio Systems Expense...

7 CFR 1770.15 - Supplementary accounts required of all borrowers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Switching—Circuit. 2212.2 2212.2 Digital Electronic Switching—Packet. 2230.11 Central Office Transmission... Retirement Work in Progress. Current Liabilities 2232.1 2232.1 Circuit Equipment—Electronic. 2232.2 2232.2... Expense—Circuit. 6212.2 6212.2 Digital Electronic Switching Expense—Packet. 6230.11 Radio Systems Expense...

7 CFR 1770.15 - Supplementary accounts required of all borrowers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Switching—Circuit. 2212.2 2212.2 Digital Electronic Switching—Packet. 2230.11 Central Office Transmission... Retirement Work in Progress. Current Liabilities 2232.1 2232.1 Circuit Equipment—Electronic. 2232.2 2232.2... Expense—Circuit. 6212.2 6212.2 Digital Electronic Switching Expense—Packet. 6230.11 Radio Systems Expense...

Microscale Digital Vacuum Electronic Gates

NASA Technical Reports Server (NTRS)

Manohara, Harish (Inventor); Mojarradi, Mohammed M. (Inventor)

2014-01-01

Systems and methods in accordance with embodiments of the invention implement microscale digital vacuum electronic gates. In one embodiment, a microscale digital vacuum electronic gate includes: a microscale field emitter that can emit electrons and that is a microscale cathode; and a microscale anode; where the microscale field emitter and the microscale anode are disposed within at least a partial vacuum; where the microscale field emitter and the microscale anode are separated by a gap; and where the potential difference between the microscale field emitter and the microscale anode is controllable such that the flow of electrons between the microscale field emitter and the microscale anode is thereby controllable; where when the microscale anode receives a flow of electrons, a first logic state is defined; and where when the microscale anode does not receive a flow of electrons, a second logic state is defined.

Congenital deformity of the paw in a captive tiger: case report

PubMed Central

2012-01-01

Background The aim of this report was to describe the clinical signs, diagnostic approach, treatment and outcome in the case of a tiger with a deformity of the paw. Case presentation A 1.5-year-old tiger (Panthera tigris) was presented with lameness of the left thoracic limb. A deformity involving the first and second metacarpal bones, and a soft tissue separation between the second and third metacarpal bones of the left front paw were observed. The second digit constantly struck the ground during locomotion. Based on the physical and radiographic evaluations, a diagnosis of ectrodactyly was made. A soft tissue reconstruction of the cleft with excision of both the second digit and distal portion of the second metacarpal bone was performed. Marked improvement of the locomotion was observed after surgical treatment, although the tiger showed a low degree of lameness probably associated with the discrepancy in length between the thoracic limbs. Conclusion This report shows a rare deformity in an exotic feline that it is compatible to ectrodactyly. Reconstructive surgery of the cleft resulted in significant improvement of limb function. PMID:22747639

Descriptive Anatomy and Three-Dimensional Reconstruction of the Skull of the Early Tetrapod Acanthostega gunnari Jarvik, 1952

PubMed Central

Porro, Laura B.; Rayfield, Emily J.; Clack, Jennifer A.

2015-01-01

The early tetrapod Acanthostega gunnari is an iconic fossil taxon exhibiting skeletal morphology reflecting the transition of vertebrates from water onto land. Computed tomography data of two Acanthostega skulls was segmented using visualization software to digitally separate bone from matrix and individual bones of the skull from each other. A revised description of cranial and lower jaw anatomy in this taxon based on CT data includes new details of sutural morphology, the previously undescribed quadrate and articular bones, and the mandibular symphysis. Sutural morphology is used to infer loading regime in the skull during feeding, and suggests Acanthostega used its anterior jaws to initially seize prey while smaller posterior teeth were used to restrain struggling prey during ingestion. Novel methods were used to repair and retrodeform the skull, resulting in a three-dimensional digital reconstruction that features a longer postorbital region and more strongly hooked anterior lower jaw than previous attempts while supporting the presence of a midline gap between the nasals and median rostrals. PMID:25760343

Electron Micrographs of Quail Limb Bones formed in microgravity

NASA Technical Reports Server (NTRS)

2003-01-01

Electron micrographs of quail limb bones that formed under the influence of microgravity show decreased mineralization compared to bones formed in normal gravity. The letters B and C indicate bone and cartilage sides of the sample, respectively, with the arrows marking the junction between bone and cartilage cells. The asterisks indicate where mineralization begins. The bone that developed during spaceflight (top) shows less mineral compared to the control sample (bottom); the control sample clearly shows mineral deposits (dark spots) that are absent in the flight sample. Quail eggs are small and develop quickly, making them ideal for space experiments. In late 2001, the Avian Development Facility (ADF) made its first flight and carried eggs used in two investigations, development and function of the irner-ear balance system in normal and altered gravity environments, and skeletal development in embryonic quail.

Dose assessment of digital tomosynthesis in pediatric imaging

NASA Astrophysics Data System (ADS)

Gislason, Amber; Elbakri, Idris A.; Reed, Martin

2009-02-01

We investigated the potential for digital tomosynthesis (DT) to reduce pediatric x-ray dose while maintaining image quality. We utilized the DT feature (VolumeRadTM) on the GE DefiniumTM 8000 flat panel system installed in the Winnipeg Children's Hospital. Facial bones, cervical spine, thoracic spine, and knee of children aged 5, 10, and 15 years were represented by acrylic phantoms for DT dose measurements. Effective dose was estimated for DT and for corresponding digital radiography (DR) and computed tomography (CT) patient image sets. Anthropomorphic phantoms of selected body parts were imaged by DR, DT, and CT. Pediatric radiologists rated visualization of selected anatomic features in these images. Dose and image quality comparisons between DR, DT, and CT determined the usefulness of tomosynthesis for pediatric imaging. CT effective dose was highest; total DR effective dose was not always lowest - depending how many projections were in the DR image set. For the cervical spine, DT dose was close to and occasionally lower than DR dose. Expert radiologists rated visibility of the central facial complex in a skull phantom as better than DR and comparable to CT. Digital tomosynthesis has a significantly lower dose than CT. This study has demonstrated DT shows promise to replace CT for some facial bones and spinal diagnoses. Other clinical applications will be evaluated in the future.

Bone Ablation at 2.94 mm Using the Free-Electron Laser and Er:YAG Laser

NASA Astrophysics Data System (ADS)

Ivanov, Borislav; Hakimian, Arman; Peavy, G. M.; Haglund, Richard

2002-03-01

Bone Ablation at 2.94 microns Using the Free-Electron Laser and Er:YAG Laser in Perfluorocarbon Compounds B. Ivanov^1, A. M. Hakimian^1, G. M. Peavy^2, R. F. Haglund, Jr.1 1Department of Physics and Astronomy, W. M. Keck Foundation Free-Electron Laser Center, Vanderbilt University, Nashville, TN 37235 2Beckman Laser Institute and Medical Clinic, College of Medicine, University of California, Irvine, CA 92612 We report studies on the efficiency of mid-IR laser ablation of cow cortical bone using the Vanderbilt free-electron laser (FEL), when irrigating the ablation zone with an inert and biocompatible perfluorocarbon compounds (PFC). At 2.94 microns, the bone matrix (mainly by water) absorbs the radiation while the PFCs transmit this wavelength, dissipate heat and acoustical stress, and prevent carbonization of the bone sample. The ablation rate, as a function of laser fluence, scanning speed and the type of PFC, was investigated. The laser fluence was estimated to be 5 J/cm^2 - 100 J/cm^2 with a laser focal spot diameter of 160 microns 500 microns and a scanning speed of 40 microns/s 2960 microns/s. The ablation rate was estimated from scanning electron microscopy to be 0.5 mm/s 2.4 mm/s. Comparisons of ablation rates with the FEL and a Er:YAG laser at 2.94 microns are being evaluated.

Digital interface of electronic transformers based on embedded system

NASA Astrophysics Data System (ADS)

Shang, Qiufeng; Qi, Yincheng

2008-10-01

Benefited from digital interface of electronic transformers, information sharing and system integration in substation can be realized. An embedded system-based digital output scheme of electronic transformers is proposed. The digital interface is designed with S3C44B0X 32bit RISC microprocessor as the hardware platform. The μCLinux operation system (OS) is transplanted on ARM7 (S3C44B0X). Applying Ethernet technology as the communication mode in the substation automation system is a new trend. The network interface chip RTL8019AS is adopted. Data transmission is realized through the in-line TCP/IP protocol of uClinux embedded OS. The application result and character analysis show that the design can meet the real-time and reliability requirements of IEC60044-7/8 electronic voltage/current instrument transformer standards.

Propulsion controls

NASA Technical Reports Server (NTRS)

Harkney, R. D.

1980-01-01

Increased system requirements and functional integration with the aircraft have placed an increased demand on control system capability and reliability. To provide these at an affordable cost and weight and because of the rapid advances in electronic technology, hydromechanical systems are being phased out in favor of digital electronic systems. The transition is expected to be orderly from electronic trimming of hydromechanical controls to full authority digital electronic control. Future propulsion system controls will be highly reliable full authority digital electronic with selected component and circuit redundancy to provide the required safety and reliability. Redundancy may include a complete backup control of a different technology for single engine applications. The propulsion control will be required to communicate rapidly with the various flight and fire control avionics as part of an integrated control concept.

Electronics. Module 3: Digital Logic Application. Instructor's Guide.

ERIC Educational Resources Information Center

Carter, Ed; Murphy, Mark

This guide contains instructor's materials for a 10-unit secondary school course on digital logic application. The units are introduction to digital, logic gates, digital integrated circuits, combination logic, flip-flops, counters and shift registers, encoders and decoders, arithmetic circuits, memory, and analog/digital and digital/analog…

Digital Games for Young Children Ages Three to Six: From Research to Design

ERIC Educational Resources Information Center

Lieberman, Debra A.; Fisk, Maria Chesley; Biely, Erica

2009-01-01

Young children ages 3 to 6 play a wide range of digital games, which are now available on large screens, handheld screens, electronic learning systems, and electronic toys, and their time spent with games is growing. This article examines effects of digital games and how they could be designed to best serve children's needs. A small body of…

Evaluation of trabecular bone patterns on dental radiographic images: influence of cortical bone

NASA Astrophysics Data System (ADS)

Amouriq, Yves; Evenou, Pierre; Arlicot, Aurore; Normand, Nicolas; Layrolle, Pierre; Weiss, Pierre; Guédon, Jean-Pierre

2010-03-01

For some authors trabecular bone is highly visible in intraoral radiographs. For other authors, the observed intrabony trabecular pattern is a representation of only the endosteal surface of cortical bone, not of intermedullary striae. The purpose of this preliminary study was to investigate the true anatomical structures that are visible in routine dental radiographs and classically denoted trabecular bone. This is a major point for bone texture analysis on radiographs. Computed radiography (CR) images of dog mandible section in molar region were compared with simulations calculated from high-resolution micro-CT volumes. Calculated simulations were obtained using the Mojette Transform. By digitally editing the CT volume, the simulations were separated into trabecular and cortical components into a region of interest. Different images were compared and correlated, some bone micro-architecture parameters calculated. A high correlation was found between computed radiographs and calculated simulations from micro-CT. The Mojette transform was successful to obtain high quality images. Cortical bone did not contribute to change in a major way simulated images. These first results imply that intrabony trabecular pattern observed on radiographs can not only be a representation of the cortical bone endosteal surface and that trabecular bone is highly visible in intraoral radiographs.

Computed tomographic analysis of temporal maxillary stability and pterygomaxillary generate formation following pediatric Le Fort III distraction advancement.

PubMed

Hopper, Richard A; Sandercoe, Gavin; Woo, Albert; Watts, Robyn; Kelley, Patrick; Ettinger, Russell E; Saltzman, Babette

2010-11-01

Le Fort III distraction requires generation of bone in the pterygomaxillary region. The authors performed retrospective digital analysis on temporal fine-cut computed tomographic images to quantify both radiographic evidence of pterygomaxillary region bone formation and relative maxillary stability. Fifteen patients with syndromic midface hypoplasia were included in the study. The average age of the patients was 8.7 years; 11 had either Crouzon or Apert syndrome. The average displacement of the maxilla during distraction was 16.2 mm (range, 7 to 31 mm). Digital analysis was performed on fine-cut computed tomographic scans before surgery, at device removal, and at annual follow-up. Seven patients also had mid-consolidation computed tomographic scans. Relative maxillary stability and density of radiographic bone in the pterygomaxillary region were calculated between each scan. There was no evidence of clinically significant maxillary relapse, rotation, or growth between the end of consolidation and 1-year follow-up, other than a relatively small 2-mm subnasal maxillary vertical growth. There was an average radiographic ossification of 0.5 mm/mm advancement at the time of device removal, with a 25th percentile value of 0.3 mm/mm. The time during consolidation that each patient reached the 25th percentile of pterygomaxillary region bone density observed in this series of clinically stable advancements ranged from 1.3 to 9.8 weeks (average, 3.7 weeks). There was high variability in the amount of bone formed in the pterygomaxillary region associated with clinical stability of the advanced Le Fort III segment. These data suggest that a subsection of patients generate the minimal amount of pterygomaxillary region bone formation associated with advancement stability as early as 4 weeks into consolidation.

Musculoskeletal Modeling Component of the NASA Digital Astronaut Project

NASA Technical Reports Server (NTRS)

Lewandowski, B. E.; Pennline, J. A.; Stalker, A. R.; Mulugeta, L.; Myers, J. G.

2011-01-01

The NASA Digital Astronaut Project s (DAP) objective is to provide computational tools that support research of the physiological response to low gravity environments and analyses of how changes cause health and safety risks to the astronauts and to the success of the mission. The spaceflight risk associated with muscle atrophy is impaired performance due to reduced muscle mass, strength and endurance. Risks of early onset of osteoporosis and bone fracture are among the spaceflight risks associated with loss of bone mineral density. METHODS: Tools under development include a neuromuscular model, a biomechanical model and a bone remodeling model. The neuromuscular model will include models of neuromuscular drive, muscle atrophy, fiber morphology and metabolic processes as a function of time in space. Human movement will be modeled with the biomechanical model, using muscle and bone model parameters at various states. The bone remodeling model will allow analysis of bone turnover, loss and adaptation. A comprehensive trade study was completed to identify the current state of the art in musculoskeletal modeling. The DAP musculoskeletal models will be developed using a combination of existing commercial software and academic research codes identified in the study, which will be modified for use in human spaceflight research. These individual models are highly dependent upon each other and will be integrated together once they reach sufficient levels of maturity. ANALYSES: The analyses performed with these models will include comparison of different countermeasure exercises for optimizing effectiveness and comparison of task requirements and the state of strength and endurance of a crew member at a particular time in a mission. DISCUSSION: The DAP musculoskeletal model has the potential to complement research conducted on spaceflight induced changes to the musculoskeletal system. It can help with hypothesis formation, identification of causative mechanisms and supplementing small data samples.

Forensic microradiology: micro-computed tomography (Micro-CT) and analysis of patterned injuries inside of bone.

PubMed

Thali, Michael J; Taubenreuther, Ulrike; Karolczak, Marek; Braun, Marcel; Brueschweiler, Walter; Kalender, Willi A; Dirnhofer, Richard

2003-11-01

When a knife is stabbed in bone, it leaves an impression in the bone. The characteristics (shape, size, etc.) may indicate the type of tool used to produce the patterned injury in bone. Until now it has been impossible in forensic sciences to document such damage precisely and non-destructively. Micro-computed tomography (Micro-CT) offers an opportunity to analyze patterned injuries of tool marks made in bone. Using high-resolution Micro-CT and computer software, detailed analysis of three-dimensional (3D) architecture has recently become feasible and allows microstructural 3D bone information to be collected. With adequate viewing software, data from 2D slice of an arbitrary plane can be extracted from 3D datasets. Using such software as a "digital virtual knife," the examiner can interactively section and analyze the 3D sample. Analysis of the bone injury revealed that Micro-CT provides an opportunity to correlate a bone injury to an injury-causing instrument. Even broken knife tips can be graphically and non-destructively assigned to a suspect weapon.

NIAMS Kids Pages on Muscles, Joints, Skin and Bones

MedlinePlus

... this research; and the dissemination of information on research progress in these diseases. Contact Us NIAMS Archive Viewers and Players Social Media Moderation Policy FOIA Privacy Statement Accessibility Disclaimer Digital Strategy ...

General-Purpose Electronic System Tests Aircraft

NASA Technical Reports Server (NTRS)

Glover, Richard D.

1989-01-01

Versatile digital equipment supports research, development, and maintenance. Extended aircraft interrogation and display system is general-purpose assembly of digital electronic equipment on ground for testing of digital electronic systems on advanced aircraft. Many advanced features, including multiple 16-bit microprocessors, pipeline data-flow architecture, advanced operating system, and resident software-development tools. Basic collection of software includes program for handling many types of data and for displays in various formats. User easily extends basic software library. Hardware and software interfaces to subsystems provided by user designed for flexibility in configuration to meet user's requirements.

Data mining and visualization of average images in a digital hand atlas

NASA Astrophysics Data System (ADS)

Zhang, Aifeng; Gertych, Arkadiusz; Liu, Brent J.; Huang, H. K.

2005-04-01

We have collected a digital hand atlas containing digitized left hand radiographs of normally developed children grouped accordingly by age, sex, and race. A set of features stored in a database reflecting patient's stage of skeletal development has been calculated by automatic image processing procedures. This paper addresses a new concept, "average" image in the digital hand atlas. The "average" reference image in the digital atlas is selected for each of the groups of normal developed children with the best representative skeletal maturity based on bony features. A data mining procedure was designed and applied to find the average image through average feature vector matching. It also provides a temporary solution for the missing feature problem through polynomial regression. As more cases are added to the digital hand atlas, it can grow to provide clinicians accurate reference images to aid the bone age assessment process.

The osteoplastic effectiveness of the implants made of mesh titanium nickelide constructs.

PubMed

Mikhailovich Irianov, Iurii; Vladimirovna Diuriagina, Olga; Iurevna Karaseva, Tatiana; Anatolevich Karasev, Evgenii

2014-02-01

The purpose of the work was to study the features of reparative osteogenesis for filling the defect of tubular bone under implantation of mesh titanium nickelide constructs. Tibial fenestrated defect was modeled experimentally in 30 Wistar pubertal rats, followed by implant intramedullary insertion. The techniques of radiography, scanning electron microscopy and X-ray electron probe microanalysis were used. The mesh implant of titanium nickelide has been established to possess biocompatibility, osteoconductive and osteoinductive properties, the zone of osteogenesis and angiogenesis is created around it, bone cover is formed. Osteointegration of the implant occurs early, by 7 days after surgery, and by 30 days after surgery organotypical re-modelling of the regenerated bone takes place, as well as the defect is filled with lamellar bone tissue by the type of bone wound primary adhesion. By 30 days after surgery mineral content of the regenerated bone tissue approximates to the composition of intact cortex mineral phase.

Scanning electron microscopy of bone: instrument, specimen, and issues.

PubMed

Boyde, A; Jones, S J

1996-02-01

There are many ways available now to maximise and analyse the information that can be obtained on the structure and constitution of bone using SEM. This paper considers a range of methods and the problems that arise relating to instrumentation and methodology as they apply to the use of SEM in the study of bone. In addition to the review content, some novel technical approaches to the SEM of bone are considered here for the first time; these include low kV imaging for the detection of new surface bone packets (and residual demineralized matrix after resorption), low kV BSE imaging of uncoated, embedded, and unembedded samples, environmental SEM for the study of wet tissue, low distortion, very low magnification imaging for the study of cancellous bone architecture, the use of multiple detectors for fast electrons in improving the imaging of porous samples, and high resolution, low voltage imaging for the study of collagen degradation during bone resorption.

The anatomy of a World Wide Web library service: the BONES demonstration project. Biomedically Oriented Navigator of Electronic Services.

PubMed Central

Schnell, E H

1995-01-01

In 1994, the John A. Prior Health Sciences Library at Ohio State University began to develop a World Wide Web demonstration project, the Biomedically Oriented Navigator of Electronic Services (BONES). The initial intent of BONES was to facilitate the health professional's access to Internet resources by organizing them in a systematic manner. The project not only met this goal but also helped identify the resources needed to launch a full-scale Web library service. This paper discusses the tasks performed and resources used in the development of BONES and describes the creation and organization of documents on the BONES Web server. The paper also discusses the outcomes of the project and the impact on the library's staff and services. PMID:8547903

Shaping the Values of Youth: Sunday School Books in 19th Century America

Science.gov Websites

develop accessible digital/electronic collections, unfortunately, not all are. The MSU Libraries are able to provide remediated, accessible versions of digital/electronic library documents to library users

Flight evaluation of modifications to a digital electronic engine control system in an F-15 airplane

NASA Technical Reports Server (NTRS)

Burcham, F. W., Jr.; Myers, L. P.; Zeller, J. R.

1983-01-01

The third phase of a flight evaluation of a digital electronic engine control system in an F-15 has recently been completed. It was found that digital electronic engine control software logic changes and augmentor hardware improvements resulted in significant improvements in engine operation. For intermediate to maximum power throttle transients, an increase in altitude capability of up to 8000 ft was found, and for idle to maximum transients, an increase of up to 4000 ft was found. A nozzle instability noted in earlier flight testing was investigated on a test engine at NASA Lewis Research Center, a digital electronic engine control software logic change was developed and evaluated, and no instability occurred in the Phase 3 flight evaluation. The backup control airstart modification was evaluated, and gave an improvement of airstart capability by reducing the minimum airspeed for successful airstarts by 50 to 75 knots.

An image-based skeletal dosimetry model for the ICRP reference newborn—internal electron sources

NASA Astrophysics Data System (ADS)

Pafundi, Deanna; Rajon, Didier; Jokisch, Derek; Lee, Choonsik; Bolch, Wesley

2010-04-01

In this study, a comprehensive electron dosimetry model of newborn skeletal tissues is presented. The model is constructed using the University of Florida newborn hybrid phantom of Lee et al (2007 Phys. Med. Biol. 52 3309-33), the newborn skeletal tissue model of Pafundi et al (2009 Phys. Med. Biol. 54 4497-531) and the EGSnrc-based Paired Image Radiation Transport code of Shah et al (2005 J. Nucl. Med. 46 344-53). Target tissues include the active bone marrow (surrogate tissue for hematopoietic stem cells), shallow marrow (surrogate tissue for osteoprogenitor cells) and unossified cartilage (surrogate tissue for chondrocytes). Monoenergetic electron emissions are considered over the energy range 1 keV to 10 MeV for the following source tissues: active marrow, trabecular bone (surfaces and volumes), cortical bone (surfaces and volumes) and cartilage. Transport results are reported as specific absorbed fractions according to the MIRD schema and are given as skeletal-averaged values in the paper with bone-specific values reported in both tabular and graphic format as electronic annexes (supplementary data). The method utilized in this work uniquely includes (1) explicit accounting for the finite size and shape of newborn ossification centers (spongiosa regions), (2) explicit accounting for active and shallow marrow dose from electron emissions in cortical bone as well as sites of unossified cartilage, (3) proper accounting of the distribution of trabecular and cortical volumes and surfaces in the newborn skeleton when considering mineral bone sources and (4) explicit consideration of the marrow cellularity changes for active marrow self-irradiation as applicable to radionuclide therapy of diseased marrow in the newborn child.

Dual function seal: visualized digital signature for electronic medical record systems.

PubMed

Yu, Yao-Chang; Hou, Ting-Wei; Chiang, Tzu-Chiang

2012-10-01

Digital signature is an important cryptography technology to be used to provide integrity and non-repudiation in electronic medical record systems (EMRS) and it is required by law. However, digital signatures normally appear in forms unrecognizable to medical staff, this may reduce the trust from medical staff that is used to the handwritten signatures or seals. Therefore, in this paper we propose a dual function seal to extend user trust from a traditional seal to a digital signature. The proposed dual function seal is a prototype that combines the traditional seal and digital seal. With this prototype, medical personnel are not just can put a seal on paper but also generate a visualized digital signature for electronic medical records. Medical Personnel can then look at the visualized digital signature and directly know which medical personnel generated it, just like with a traditional seal. Discrete wavelet transform (DWT) is used as an image processing method to generate a visualized digital signature, and the peak signal to noise ratio (PSNR) is calculated to verify that distortions of all converted images are beyond human recognition, and the results of our converted images are from 70 dB to 80 dB. The signature recoverability is also tested in this proposed paper to ensure that the visualized digital signature is verifiable. A simulated EMRS is implemented to show how the visualized digital signature can be integrity into EMRS.

WE-E-BRE-01: An Image-Based Skeletal Dosimetry Model for the ICRP Reference Adult Female - Internal Electron Sources

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

O'Reilly, S; Maynard, M; Marshall, E

Purpose: Limitations seen in previous skeletal dosimetry models, which are still employed in commonly used software today, include the lack of consideration of electron escape and cross-fire from cortical bone, the modeling of infinite spongiosa, the disregard of the effect of varying cellularity on active marrow self-irradiation, and the lack of use of the more recent ICRP definition of a 50 micron surrogate tissue region for the osteoprogenitor cells - shallow marrow. These limitations were addressed in the present dosimetry model. Methods: Electron transport was completed to determine specific absorbed fractions to active marrow and shallow marrow of the skeletalmore » regions of the adult female. The bone macrostructure was obtained from the whole-body hybrid computational phantom of the UF series of reference phantoms, while the bone microstructure was derived from microCT images of skeletal region samples taken from a 45 year-old female cadaver. The target tissue regions were active marrow and shallow marrow. The source tissues were active marrow, inactive marrow, trabecular bone volume, trabecular bone surfaces, cortical bone volume and cortical bone surfaces. The marrow cellularity was varied from 10 to 100 percent for active marrow self-irradiation. A total of 33 discrete electron energies, ranging from 1 keV to 10 MeV, were either simulated or modeled analytically. Results: The method of combining macro- and microstructure absorbed fractions calculated using MCNPX electron transport was found to yield results similar to those determined with the PIRT model for the UF adult male in the Hough et al. study. Conclusion: The calculated skeletal averaged absorbed fractions for each source-target combination were found to follow similar trends of more recent dosimetry models (image-based models) and did not follow current models used in nuclear medicine dosimetry at high energies (due to that models use of an infinite expanse of trabecular spongiosa)« less

Multipurpose panel, phase 1, study report. [display utilizing multiplexing and digital techniques

NASA Technical Reports Server (NTRS)

Parkin, W.

1975-01-01

The feasibility of a multipurpose panel which provides a programmable electronic display for changeable panel nomenclature, multiplexes similar indicator display signals to the signal display, and demultiplexes command signals is examined. Topics discussed include: electronic display technology, miniaturized electronic and memory devices, and data management systems which employ digital address and multiplexing.

Propulsion control experience used in the Highly Integrated Digital Electronic Control (HIDEC) program

NASA Technical Reports Server (NTRS)

Myers, L. P.; Burcham, F. W., Jr.

1984-01-01

The highly integrated digital electronic control (HIDEC) program will integrate the propulsion and flight control systems on an F-15 airplane at NASA Ames Research Center's Dryden Flight Research Facility. Ames-Dryden has conducted several propulsion control programs that have contributed to the HIDEC program. The digital electronic engine control (DEEC) flight evaluation investigated the performance and operability of the F100 engine equipped with a full-authority digital electronic control system. Investigations of nozzle instability, fault detection and accommodation, and augmentor transient capability provided important information for the HIDEC program. The F100 engine model derivative (EMD) was also flown in the F-15 airplane, and airplane performance was significantly improved. A throttle response problem was found and solved with a software fix to the control logic. For the HIDEC program, the F100 EMD engines equipped with DEEC controls will be integrated with the digital flight control system. The control modes to be implemented are an integrated flightpath management mode and an integrated adaptive engine control system mode. The engine control experience that will be used in the HIDEC program is discussed.

Radiographic bone loss in a Scottish non-smoking Type 1 Diabetes mellitus population; a Bitewing Radiographic Study.

PubMed

Plessas, Anastasios; Robertson, Douglas P; Hodge, Penny J

2018-05-15

The dental complications of uncontrolled diabetes include reduced salivary flow rate, candidiasis and periodontal manifestations. A recent meta-analysis concluded that diabetes patients have a significantly higher severity, but not extent, of destructive periodontal disease than non-diabetes people. The authors reported that most type-1 diabetes studies using dental radiographic data have not controlled for confounding factors such as smoking. The aim of this cross-sectional study was to compare radiographic alveolar bone loss between type 1 diabetes (T1DM) and non-diabetes (NDM) participants in a Scottish non-smoking population. Digital bitewing radiographs for 174 Scottish adult never or ex-smoker (> 5 years) participants (108 T1DM, 66 NDS), recruited from outpatient clinics throughout Greater Glasgow and Clyde, were included in the analysis. A single blinded, trained and calibrated examiner recorded the radiographic bone loss seen on bitewing radiographs using the digital screen caliper. The bone loss was measured as the distance between the cemento-enamel junction (CEJ) and the deepest radiographic alveolar bone margin interproximally of each tooth. T1DM participants had more radiographic alveolar bone loss throughout the all teeth measured (median:1.27 mm vs 1.06 mm, P < 0.001) and more than a two fold increase in the risk of having sites with ≥2 mm periodontal destruction (OR = 2.297, 95%CI 1.058-4.986, P = 0.036) compared with non-diabetes subjects. Patients suffering from type 1 diabetes are at higher risk of periodontitis even when controlling for multiple possible confounding factors and this difference can be detected on routine dental radiographs at an early stage. These data confirm radiographically the previously reported association between T1DM and periodontal bone loss. This article is protected by copyright. All rights reserved. © 2018 American Academy of Periodontology.

Oreopithecus was a bipedal ape after all: Evidence from the iliac cancellous architecture

PubMed Central

Rook, Lorenzo; Bondioli, Luca; Köhler, Meike; Moyà-Solà, Salvador; Macchiarelli, Roberto

1999-01-01

Textural properties and functional morphology of the hip bone cancellous network of Oreopithecus bambolii, a 9- to 7-million-year-old Late Miocene hominoid from Italy, provide insights into the postural and locomotor behavior of this fossil ape. Digital image processing of calibrated hip bone radiographs reveals the occurrence of trabecular features, which, in humans and fossil hominids, are related to vertical support of the body weight, i.e., to bipedality. PMID:10411955

New 3D model for dynamics modeling

NASA Astrophysics Data System (ADS)

Perez, Alain

1994-05-01

The wrist articulation represents one of the most complex mechanical systems of the human body. It is composed of eight bones rolling and sliding along their surface and along the faces of the five metacarpals of the hand and the two bones of the arm. The wrist dynamics are however fundamental for the hand movement, but it is so complex that it still remains incompletely explored. This work is a part of a new concept of computer-assisted surgery, which consists in developing computer models to perfect surgery acts by predicting their consequences. The modeling of the wrist dynamics are based first on the static model of its bones in three dimensions. This 3D model must optimise the collision detection procedure which is the necessary step to estimate the physical contact constraints. As many other possible computer vision models do not fit with enough precision to this problem, a new 3D model has been developed thanks to the median axis of the digital distance map of the bones reconstructed volume. The collision detection procedure is then simplified for contacts are detected between spheres. The experiment of this original 3D dynamic model products realistic computer animation images of solids in contact. It is now necessary to detect ligaments on digital medical images and to model them in order to complete a wrist model.

Effect of macro-design of immediately loaded implants on micromotion and stress distribution in surrounding bone using finite element analysis.

PubMed

Fazel, Akbar; Aalai, Shima; Rismanchian, Mansour

2009-08-01

Macro-design influences the initial stability of implant and reduces micromotions. The aim of this study was to determine and compare micromotions and stress distribution in the bone around immediately loaded Maestro and Xive implants using finite element analysis. In this experimental study, accurate, clear photos were prepared of Xive and Maestro implants 12 and 13 mm long and 4 and 3.8 mm in diameter, respectively, using a Nikon Digital Camera with a resolution 5.24-megapixels with 8x Optical Zoom and 4x Digital Zoom. After accurate measurements, 3-D models of the implants inside the lower mandible (D2) were processed in Solidworks Version 2003 environment and transferred into Ansys for finite element analysis. After loading of 500 N angled at 70 degrees from the horizontal plane, the micromotion of the implant and Von Misses stresses around the bone were measured. The measured micromotion in Maestro implant was 148 mum and that in Xive was 284 mum. Stress distribution in the bone surrounding Maestro implant was better than Xive, but maximum stress surrounding Xive implants (30 MPa) was lower than Maestro (33 MPa). Based on the results obtained in the present study, maximum micromotion in maestro was less than that in Xive implants. This finding can guarantee the application of maestro implants for immediate loading.

Allogeneic adipose-derived stem cells regenerate bone in a critical-sized ulna segmental defect

PubMed Central

Wen, Congji; Yan, Hai; Fu, Shibo; Qian, Yunliang

2016-01-01

Adipose-derived stem cells (ASCs) with multilineage potential can be induced into osteoblasts, adipocytes and chondrocytes. ASCs as seed cell are widely used in the field of tissue engineering, but most studies either use autologous cells as the source or an immunodeficient animal as the host. In our present study, we explored the feasibility of applying allogeneic ASCs and demineralized bone matrix (DBM) scaffolds for repairing tubular bone defects without using immunosuppressive therapy. Allogeneic ASCs were expanded and seeded on DBM scaffolds and induced to differentiate along the osteogenic lineage. Eight Sprague–Dawley (SD) rats were used in this study and bilateral critical-sized defects (8 mm) of the ulna were created and divided into two groups: with ASC-DBM constructs or DBM alone. The systemic immune response and the extent of bone healing were evaluated post-operatively. Twenty-four weeks after implantation, digital radiography (DR) testing showed that new bones had formed in the experimental group. By contrast, no bone tissue formation was observed in the control group. This study demonstrated that allogeneic ASCs could promote bone regeneration and repair tubular bone defects combined with DBM by histologically typical bone without systemic immune response PMID:25819682

The nanometre-scale physiology of bone: steric modelling and scanning transmission electron microscopy of collagen–mineral structure

PubMed Central

Alexander, Benjamin; Daulton, Tyrone L.; Genin, Guy M.; Lipner, Justin; Pasteris, Jill D.; Wopenka, Brigitte; Thomopoulos, Stavros

2012-01-01

The nanometre-scale structure of collagen and bioapatite within bone establishes bone's physical properties, including strength and toughness. However, the nanostructural organization within bone is not well known and is debated. Widely accepted models hypothesize that apatite mineral (‘bioapatite’) is present predominantly inside collagen fibrils: in ‘gap channels’ between abutting collagen molecules, and in ‘intermolecular spaces’ between adjacent collagen molecules. However, recent studies report evidence of substantial extrafibrillar bioapatite, challenging this hypothesis. We studied the nanostructure of bioapatite and collagen in mouse bones by scanning transmission electron microscopy (STEM) using electron energy loss spectroscopy and high-angle annular dark-field imaging. Additionally, we developed a steric model to estimate the packing density of bioapatite within gap channels. Our steric model and STEM results constrain the fraction of total bioapatite in bone that is distributed within fibrils at less than or equal to 0.42 inside gap channels and less than or equal to 0.28 inside intermolecular overlap regions. Therefore, a significant fraction of bone's bioapatite (greater than or equal to 0.3) must be external to the fibrils. Furthermore, we observe extrafibrillar bioapatite between non-mineralized collagen fibrils, suggesting that initial bioapatite nucleation and growth are not confined to the gap channels as hypothesized in some models. These results have important implications for the mechanics of partially mineralized and developing tissues. PMID:22345156

Ultrasonographic assessment of the proximal digital annular ligament in the equine forelimb.

PubMed

Dik, K J; Boroffka, S; Stolk, P

1994-01-01

Ultrasonography was used with 6 normal cadaver forelimbs of Dutch Warmblood horses to delineate the ultrasonographic anatomy of the palmar pastern region, with emphasis on the proximal digital annular ligament. Using a 5.5 MHz sector scanner, the thin proximal digital annular ligament was not visible on offset sonograms. Only if the digital sheath in the normal limb was distended was the distal border of this ligament outlined. In all normal limbs the palmarodistal thickness of the combined skin-proximal digital annular ligament layer in the mid-pastern region was 2 mm. The flexor tendons and distal sesamoidean ligaments were easily identified as hyperechoic structures. Distension of the digital sheath in the normal limbs clearly outlined the anechoic digital sheath pouches. In 4 lame horses ultrasonography aided the diagnosis of functional proximal digital annular ligament constriction. In all 4 diseased forelimbs ultrasonography demonstrated thickening of the skin-proximal digital annular ligament layer and distension of the digital sheath. In one of these limbs the distended digital sheath was also thickened. The flexor tendons and distal sesamoidean ligaments were normal. There was no radiographic evidence of additional bone or joint lesions.

Fractographic examination of racing greyhound central (navicular) tarsal bone failure surfaces using scanning electron microscopy.

PubMed

Tomlin, J L; Lawes, T J; Blunn, G W; Goodship, A E; Muir, P

2000-09-01

The greyhound is a fatigue fracture model of a short distance running athlete. Greyhounds have a high incidence of central (navicular) tarsal bone (CTB) fractures, which are not associated with overt trauma. We wished to determine whether these fractures occur because of accumulation of fatigue microdamage. We hypothesized that bone from racing dogs would show site-specific microdamage accumulation, causing predisposition to structural failure. We performed a fractographic examination of failure surfaces from fractured bones using scanning electron microscopy and assessed microcracking observed at the failure surface using a visual analog scale. Branching arrays of microcracks were seen in failure surfaces of CTB and adjacent tarsal bones, suggestive of compressive fatigue failure. Branching arrays of microcracks were particularly prevalent in remodeled trabecular bone that had become compact. CTB fractures showed increased microdamage when compared with other in vivo fractures (adjacent tarsal bone and long bone fractures), and ex vivo tarsal fractures induced by monotonic loading (P < 0.02). It was concluded that greyhound racing and training often results in CTB structural failure, because of accumulation and coalescence of branching arrays of fatigue microcracks, the formation of which appears to be predisposed to adapted bone.

LC21-Hopes and Cautions for the Library of Congress; The NSF National Science, Mathematics, Engineering, and Technology Education Digital Library (NSDL) Program: A Progress Report; A Grammar of Dublin Core; Measuring the Impact of an Electronic Journal Collection on Library Costs: A Framework and Preliminary Observations; Emulation As a Digital Preservation Strategy.

ERIC Educational Resources Information Center

O'Donnell, James J.; Zia, Lee L.; Baker, Thomas; Montgomery, Carol Hansen; Granger, Stewart

2000-01-01

Includes five articles: (1) discusses Library of Congress efforts to include digital materials; (2) describes the National Science Foundation (NSF) digital library program to improve science, math, engineering, and technology education; (3) explains Dublin Core grammar; (4) measures the impact of electronic journals on library costs; and (5)…

Image acquisitions, processing and analysis in the process of obtaining characteristics of horse navicular bone

NASA Astrophysics Data System (ADS)

Zaborowicz, M.; Włodarek, J.; Przybylak, A.; Przybył, K.; Wojcieszak, D.; Czekała, W.; Ludwiczak, A.; Boniecki, P.; Koszela, K.; Przybył, J.; Skwarcz, J.

2015-07-01

The aim of this study was investigate the possibility of using methods of computer image analysis for the assessment and classification of morphological variability and the state of health of horse navicular bone. Assumption was that the classification based on information contained in the graphical form two-dimensional digital images of navicular bone and information of horse health. The first step in the research was define the classes of analyzed bones, and then using methods of computer image analysis for obtaining characteristics from these images. This characteristics were correlated with data concerning the animal, such as: side of hooves, number of navicular syndrome (scale 0-3), type, sex, age, weight, information about lace, information about heel. This paper shows the introduction to the study of use the neural image analysis in the diagnosis of navicular bone syndrome. Prepared method can provide an introduction to the study of non-invasive way to assess the condition of the horse navicular bone.

Development strategy and process models for phased automation of design and digital manufacturing electronics

NASA Astrophysics Data System (ADS)

Korshunov, G. I.; Petrushevskaya, A. A.; Lipatnikov, V. A.; Smirnova, M. S.

2018-03-01

The strategy of quality of electronics insurance is represented as most important. To provide quality, the processes sequence is considered and modeled by Markov chain. The improvement is distinguished by simple database means of design for manufacturing for future step-by-step development. Phased automation of design and digital manufacturing electronics is supposed. The MatLab modelling results showed effectiveness increase. New tools and software should be more effective. The primary digital model is proposed to represent product in the processes sequence from several processes till the whole life circle.

Digital Electronic Engine Control (DEEC) Flight Evaluation in an F-15 Airplane

NASA Technical Reports Server (NTRS)

1984-01-01

Flight evaluation in an F-15 aircraft by digital electronic engine control (DEEC) was investigated. Topics discussed include: system description, F100 engine tests, effects of inlet distortion on static pressure probe, flight tests, digital electronic engine control fault detection and accommodation flight evaluation, flight evaluation of a hydromechanical backup control, augmentor transient capability of an F100 engine, investigation of nozzle instability, real time in flight thrust calculation, and control technology for future aircraft propulsion systems. It is shown that the DEEC system is a powerful and flexible controller for the F100 engine.

Digital diffractive optics: Have diffractive optics entered mainstream industry yet?

NASA Astrophysics Data System (ADS)

Kress, Bernard; Hejmadi, Vic

2010-05-01

When a new technology is integrated into industry commodity products and consumer electronic devices, and sold worldwide in retail stores, it is usually understood that this technology has then entered the realm of mainstream technology and therefore mainstream industry. Such a leap however does not come cheap, as it has a double edge sword effect: first it becomes democratized and thus massively developed by numerous companies for various applications, but also it becomes a commodity, and thus gets under tremendous pressure to cut down its production and integration costs while not sacrificing to performance. We will show, based on numerous examples extracted from recent industry history, that the field of Diffractive Optics is about to undergo such a major transformation. Such a move has many impacts on all facets of digital diffractive optics technology, from the optical design houses to the micro-optics foundries (for both mastering and volume replication), to the final product integrators or contract manufacturers. The main causes of such a transformation are, as they have been for many other technologies in industry, successive technological bubbles which have carried and lifted up diffractive optics technology within the last decades. These various technological bubbles have been triggered either by real industry needs or by virtual investment hype. Both of these causes will be discussed in the paper. The adjective ""digital"" in "digital diffractive optics" does not refer only, as it is done in digital electronics, to the digital functionality of the element (digital signal processing), but rather to the digital way they are designed (by a digital computer) and fabricated (as wafer level optics using digital masking techniques). However, we can still trace a very strong similarity between the emergence of micro-electronics from analog electronics half a century ago, and the emergence of digital optics from conventional optics today.

Superconductor Digital Electronics: -- Current Status, Future Prospects

NASA Astrophysics Data System (ADS)

Mukhanov, Oleg

2011-03-01

Two major applications of superconductor electronics: communications and supercomputing will be presented. These areas hold a significant promise of a large impact on electronics state-of-the-art for the defense and commercial markets stemming from the fundamental advantages of superconductivity: simultaneous high speed and low power, lossless interconnect, natural quantization, and high sensitivity. The availability of relatively small cryocoolers lowered the foremost market barrier for cryogenically-cooled superconductor electronic systems. These fundamental advantages enabled a novel Digital-RF architecture - a disruptive technological approach changing wireless communications, radar, and surveillance system architectures dramatically. Practical results were achieved for Digital-RF systems in which wide-band, multi-band radio frequency signals are directly digitized and digital domain is expanded throughout the entire system. Digital-RF systems combine digital and mixed signal integrated circuits based on Rapid Single Flux Quantum (RSFQ) technology, superconductor analog filter circuits, and semiconductor post-processing circuits. The demonstrated cryocooled Digital-RF systems are the world's first and fastest directly digitizing receivers operating with live satellite signals, enabling multi-net data links, and performing signal acquisition from HF to L-band with 30 GHz clock frequencies. In supercomputing, superconductivity leads to the highest energy efficiencies per operation. Superconductor technology based on manipulation and ballistic transfer of magnetic flux quanta provides a superior low-power alternative to CMOS and other charge-transfer based device technologies. The fundamental energy consumption in SFQ circuits defined by flux quanta energy 2 x 10-19 J. Recently, a novel energy-efficient zero-static-power SFQ technology, eSFQ/ERSFQ was invented, which retains all advantages of standard RSFQ circuits: high-speed, dc power, internal memory. The voltage bias regulation, determined by SFQ clock, enables the zero-power at zero-activity regimes, indispensable for sensor and quantum bit readout.

Validation of a commercial TPS based on the VMC(++) Monte Carlo code for electron beams: commissioning and dosimetric comparison with EGSnrc in homogeneous and heterogeneous phantoms.

PubMed

Ferretti, A; Martignano, A; Simonato, F; Paiusco, M

2014-02-01

The aim of the present work was the validation of the VMC(++) Monte Carlo (MC) engine implemented in the Oncentra Masterplan (OMTPS) and used to calculate the dose distribution produced by the electron beams (energy 5-12 MeV) generated by the linear accelerator (linac) Primus (Siemens), shaped by a digital variable applicator (DEVA). The BEAMnrc/DOSXYZnrc (EGSnrc package) MC model of the linac head was used as a benchmark. Commissioning results for both MC codes were evaluated by means of 1D Gamma Analysis (2%, 2 mm), calculated with a home-made Matlab (The MathWorks) program, comparing the calculations with the measured profiles. The results of the commissioning of OMTPS were good [average gamma index (γ) > 97%]; some mismatches were found with large beams (size ≥ 15 cm). The optimization of the BEAMnrc model required to increase the beam exit window to match the calculated and measured profiles (final average γ > 98%). Then OMTPS dose distribution maps were compared with DOSXYZnrc with a 2D Gamma Analysis (3%, 3 mm), in 3 virtual water phantoms: (a) with an air step, (b) with an air insert, and (c) with a bone insert. The OMTPD and EGSnrc dose distributions with the air-water step phantom were in very high agreement (γ ∼ 99%), while for heterogeneous phantoms there were differences of about 9% in the air insert and of about 10-15% in the bone region. This is due to the Masterplan implementation of VMC(++) which reports the dose as "dose to water", instead of "dose to medium". Copyright © 2013 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

AMSARA: Accession Medical Standards Analysis & Research Activity 2008 Annual Report

DTIC Science & Technology

2009-02-01

service were prosthetic implants and diseases of the musculoskeletal system and impairments and diseases of the spine, skull, limbs, and extremities...waivers for deviations/curvature of the spine, and one had a waiver for a  15  fracture of the vertebral column (no mention of spinal cord injury). For...pathologic fractures , bone cysts, and aseptic necrosis. Please note, when a majority of codes examined out to the fourth digit do not have a fourth digit

Bone lengthening for congenital differences of the hands and digits in children.

PubMed

Matsuno, Takahiro; Ishida, Osamu; Sunagawa, Toru; Ichikawa, Makoto; Ikuta, Yoshikazu; Ochi, Mitsuo

2004-07-01

We investigated the growth of bones after lengthening to evaluate the effectiveness and usefulness of bone lengthening in congenital hand deficiencies. Bone lengthening was performed to treat congenital hand deficiencies including hypoplastic thumb, hypoplasia of the small finger, cleft hand, metacarpal synostosis, brachymetacarpia, symbrachydactyly, and amniotic band syndrome. A total of 15 patients (1-13 years old) underwent lengthening of 23 bones. The average of distraction was 10 mm. The mean follow-up period was 59 months. The length of the bones at follow-up evaluation was measured and then compared with the length of the bones immediately after lengthening. The bone growth after lengthening, the percentage of growth after lengthening, and the growth rate were compared among diagnostic groups. In the cases involving older patients the bone length changed little and the growth plates of these patients closed naturally soon after lengthening. In contrast, in the cases in which the patients were younger than 7 years old the lengthened bones grew continuously. The amount of bone growth was different for each disease in the younger patients. In patients with amniotic band syndrome the lengthened bones grew at the same rate as the bones in the hand. Other diagnoses such as symbrachydactyly had a different growth pattern in the hand. We conclude that bone lengthening is a reliable method for the correction of congenital differences of the hand. The indications for this procedure must be determined while considering the relationship between the specific disease and subsequent bone growth.

Stereomicroscopic evaluation of the joint cartilage and bone tissue in osteoporosis

NASA Astrophysics Data System (ADS)

Vasile, Liliana; Torok, Rodica; Deleanu, Bogdan; Marchese, Cristian; Valeanu, Adina; Bodea, Rodica

2012-06-01

Aim of the study. Assessment by stereomicroscopy of the severity of lesions in osteoporotic bone at both sexes and to correlate micro-and macro-bone fracture due to low bone density values with the disease evolution. Material and method: The study material consists of fragments of bone from the femoral head, vertebral bone, costal and iliac crest biopsy obtained from patients aged over 70 years, female and male, treated in the County Hospital of Timisoara, Department of Orthopedics. For the purpose of studying the samples in stereomicroscopy and trough polarized light it has been used the Olympus Microscope SZ ×7 and an Olympus camera with 2,5 × digital zoom and a 3× optical zoom in the Vest Politechnic Univesity. Results and discussions: Subchondral bone presents osteolysis associated with a osteoporotic bone transformation. Pseudocystic chondrolisis was noted in the osteoarticular cartilage, in addition with areas of hemorrhagic postfractural necrosis. The osteoporotic bone exhibits ischemic necrosis and focal hemorrhagic necrosis adjacent fracture. Microporosity pattern of the bone observed by stereomicroscopy correspond to the spongy bone osteoporosis images. Morphometry of the bone spiculi reveals length of 154.88 and 498.32 μ. In men we found a greater thickness of bone trabeculi compared with bone texture porosity in women. The subchondral bone supports and fulfills an important role in transmitting forces from the overlying articular cartilage inducing the bone resorbtion. The femoral head fracture may be the final event of many accumulated bone microcracks. Conclusions: Bone fragility depends not only of the spongy bone but also of the cortical bone properties. Osteolysis produced by loss of balance in the process of remodeling in favor of bone resorption leads to the thinning of the subchondral bone at both sexes.

Adaptive histogram equalization in digital radiography of destructive skeletal lesions.

PubMed

Braunstein, E M; Capek, P; Buckwalter, K; Bland, P; Meyer, C R

1988-03-01

Adaptive histogram equalization, an image-processing technique that distributes pixel values of an image uniformly throughout the gray scale, was applied to 28 plain radiographs of bone lesions, after they had been digitized. The non-equalized and equalized digital images were compared by two skeletal radiologists with respect to lesion margins, internal matrix, soft-tissue mass, cortical breakthrough, and periosteal reaction. Receiver operating characteristic (ROC) curves were constructed on the basis of the responses. Equalized images were superior to nonequalized images in determination of cortical breakthrough and presence or absence of periosteal reaction. ROC analysis showed no significant difference in determination of margins, matrix, or soft-tissue masses.

Histomorphometric reference data of transiliac bone biopsy in children from 8 to 17 years old.

PubMed

Velásquez-Forero, Francisco H; Jiménez-Brau, Daniel A; Esparza-García, Mariela

2018-01-01

Histomorphometric analysis of bone samples is a key tool for studying bone metabolism; however, only a few pediatric reference data exist. The aim of the present study is to report more reference data and to investigate if histomorphometric differences exist between age and gender. We obtained 19 transiliac bone samples previously marked with tetracycline, from children between 8 and 17 years (13 were male), with normal blood test results and urine biochemical bone markers. We evaluated bone histomorphometric parameters using a digitalizing table with osteomeasure to obtain normative data of means and standard deviations, as well as median and range. Due to the small sample, a Monte Carlo simulation was applied. Structural, static, dynamic, and resorptic histomorphometric parameters were evaluated by age and gender following the American Society for Bone and Mineral Research recommendations. Bone volume (in the older children) and mineral apposition rate (in the younger children), the eroded surface (in boys), and the new bone wall thickness (in girls) were significantly increased. On the trabecular area of mineralization front, the modeling and the remodeling bone formation were similar (16 and 18%). The rest of the histomorphometric bone parameters by age and gender showed no significant difference. In healthy children, these bone histomorphometric findings, with these techniques and for this ages could be used as reference values. Copyright: © 2018 Permanyer.

Automated bone age assessment of older children using the radius

NASA Astrophysics Data System (ADS)

Tsao, Sinchai; Gertych, Arkadiusz; Zhang, Aifeng; Liu, Brent J.; Huang, Han K.

2008-03-01

The Digital Hand Atlas in Assessment of Skeletal Development is a large-scale Computer Aided Diagnosis (CAD) project for automating the process of grading Skeletal Development of children from 0-18 years of age. It includes a complete collection of 1,400 normal hand X-rays of children between the ages of 0-18 years of age. Bone Age Assessment is used as an index of skeletal development for detection of growth pathologies that can be related to endocrine, malnutrition and other disease types. Previous work at the Image Processing and Informatics Lab (IPILab) allowed the bone age CAD algorithm to accurately assess bone age of children from 1 to 16 (male) or 14 (female) years of age using the Phalanges as well as the Carpal Bones. At the older ages (16(male) or 14(female) -19 years of age) the Phalanges as well as the Carpal Bones are fully developed and do not provide well-defined features for accurate bone age assessment. Therefore integration of the Radius Bone as a region of interest (ROI) is greatly needed and will significantly improve the ability to accurately assess the bone age of older children. Preliminary studies show that an integrated Bone Age CAD that utilizes the Phalanges, Carpal Bones and Radius forms a robust method for automatic bone age assessment throughout the entire age range (1-19 years of age).

Comparison between the effects of platelet-rich plasma and bone marrow concentrate on defect consolidation in the rabbit tibia

PubMed Central

Batista, Marco Antonio; Leivas, Tomaz Puga; Rodrigues, Consuelo Junqueira; Arenas, Géssica Cantadori Funes; Belitardo, Donizeti Rodrigues; Guarniero, Roberto

2011-01-01

OBJECTIVE: To perform a comparative analysis of the effects of platelet-rich plasma and centrifuged bone marrow aspirate on the induction of bone healing in rabbits. METHOD: Twenty adult, male New Zealand rabbits were randomly separated into two equal groups, and surgery was performed to create a bone defect (a cortical orifice 3.3 mm in diameter) in the proximal metaphysis of each rabbit's right tibia. In the first group, platelet-rich plasma was implanted in combination with β-tricalcium phosphate (platelet-rich plasma group), and in the second group, centrifuged bone marrow in combination with β-tricalcium phosphate (centrifuged bone marrow group) was implanted. After a period of four weeks, the animals were euthanized, and the tibias were evaluated using digital radiography, computed tomography, and histomorphometry. RESULTS: Seven samples from each group were evaluated. The radiographic evaluation confirmed the absence of fractures in the postoperative limb and identified whether bone consolidation had occurred. The tomographic evaluation revealed a greater amount of consolidation and the formation of a greater cortical bone thickness in the platelet-rich plasma group. The histomorphometry revealed a greater bone density in the platelet-rich plasma group compared with the centrifuged bone marrow group. CONCLUSION: After four weeks, the platelet-rich plasma promoted a greater amount of bone consolidation than the bone marrow aspirate concentrate. PMID:22012052

Digital Audio Radio Broadcast Systems Laboratory Testing Nearly Complete

NASA Technical Reports Server (NTRS)

2005-01-01

Radio history continues to be made at the NASA Lewis Research Center with the completion of phase one of the digital audio radio (DAR) testing conducted by the Consumer Electronics Group of the Electronic Industries Association. This satellite, satellite/terrestrial, and terrestrial digital technology will open up new audio broadcasting opportunities both domestically and worldwide. It will significantly improve the current quality of amplitude-modulated/frequency-modulated (AM/FM) radio with a new digitally modulated radio signal and will introduce true compact-disc-quality (CD-quality) sound for the first time. Lewis is hosting the laboratory testing of seven proposed digital audio radio systems and modes. Two of the proposed systems operate in two modes each, making a total of nine systems being tested. The nine systems are divided into the following types of transmission: in-band on-channel (IBOC), in-band adjacent-channel (IBAC), and new bands. The laboratory testing was conducted by the Consumer Electronics Group of the Electronic Industries Association. Subjective assessments of the audio recordings for each of the nine systems was conducted by the Communications Research Center in Ottawa, Canada, under contract to the Electronic Industries Association. The Communications Research Center has the only CCIR-qualified (Consultative Committee for International Radio) audio testing facility in North America. The main goals of the U.S. testing process are to (1) provide technical data to the Federal Communication Commission (FCC) so that it can establish a standard for digital audio receivers and transmitters and (2) provide the receiver and transmitter industries with the proper standards upon which to build their equipment. In addition, the data will be forwarded to the International Telecommunications Union to help in the establishment of international standards for digital audio receivers and transmitters, thus allowing U.S. manufacturers to compete in the world market.

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

Arentsen, L; Lopater, Z; Dusenbery, K

Purpose: Duputren’s contracture (DC) is a benign disease characterized by abnormal thickening of the fascial surfaces of the hands or feet causing curling of the surface, functional impairment, weakness, and pain. The purpose of the investigation is to describe the radiation treatment approaches, compare these techniques, and discuss the potential side effects and complications of these techniques. Methods: Early stage DC has been treated with 120 kVp X rays but also with high-energy electrons or photons. High-energy electrons have been the radiation of choice but severe contracture of the hand makes it difficult to produce a plan with acceptable dosemore » uniformity. High-energy photons can overcome this difficulty either by directing a beam onto the palmer or back of the surface of the hand, including bolus to maximize the surface dose. We calculated the dose to the bone for the 120 kVp treatment using published %DD data and mass energy absorption coefficients for bone and muscle. Results: The dose to underlying bone from megavoltage photons and electrons is essentially the same, but dose to the bone for using 120 kVp can be 4–5 times greater due to the photoelectric effect. For the 30 Gy dose deliver using this technique, the dose to the bone could be 84–105 Gy after taking the penetration of the beam into account. After radiotherapy, there is often decreased osteoblastic activity and vascular fibrosis that leads to osteitis, atrophy, and decreased metabolic bone activity. Incidence of fractures occurs routinely above 60 Gy with higher doses potentially leading to higher incidences of bone complications. Conclusion: Radiation therapy for DC using low-energy X rays can deliver a prohibitively high dose to the underlying bone potentially leading to severe bone complications.« less

Utilization of fish bone as adsorbent of Fe3+ ion by controllable removal of its carbonaceous component

NASA Astrophysics Data System (ADS)

Nurhadi, M.; Kusumawardani, R.; Widiyowati, I. I.; Wirhanuddin; Nur, H.

2018-05-01

The performance of fish bone to adsorb Fe3+ ion in solution was studied. Powdered fish bone and carbonized fish bone were used as adsorbent. All absorbents were characterized by X-ray diffraction (XRD), IR spectroscopy, nitrogen adsorption, scanning electron microscopy (SEM) and TG analysis. Powdered fish bone and carbonized fish bone were effective as adsorbent for removing Fe3+ ion in solution. The metal adsorptions of Fe3+ ion were 94 and 98% for powdered fish bone and fish bone which carbonized at 400 and 500 °C.

Changes in Mechanical Properties of Rat Bones under Simulated Effects of Microgravity and Radiation†

NASA Astrophysics Data System (ADS)

Walker, Azida H.; Perkins, Otis; Mehta, Rahul; Ali, Nawab; Dobretsov, Maxim; Chowdhury, Parimal

The aim of this study was to determine the changes in elasticity and lattice structure in leg bone of rats which were: 1) under Hind-Limb Suspension (HLS) by tail for 2 weeks and 2) exposed to a total radiation of 10 Grays in 10 days. The animals were sacrificed at the end of 2 weeks and the leg bones were surgically removed, cleaned and fixed with a buffered solution. The mechanical strength of the bone (elastic modulus) was determined from measurement of bending of a bone when under an applied force. Two methodologies were used: i) a 3-point bending technique and ii) classical bending where bending is accomplished keeping one end fixed. Three point bending method used a captive actuator controlled by a programmable IDEA drive. This allowed incremental steps of 0.047 mm for which the force is measured. The data is used to calculate the stress and the strain. In the second method a mirror attached to the free end of the bone allowed a reflected laser beam spot to be tracked. This provided the displacement measurement as stress levels changed. Analysis of stress vs. strain graph together with solution of Euler-Bernoulli equation for a cantilever beam allowed determination of the elastic modulus of the leg bone for (i) control samples, (ii) HLS samples and (iii) HLS samples with radiation effects. To ascertain changes in the bone lattice structure, the bones were cross-sectioned and imaged with a 20 keV beam of electrons in a Scanning Electron Microscope (SEM). A backscattered detector and a secondary electron detector in the SEM provided the images from well-defined parts of the leg bones. Elemental compositions in combination with mechanical properties (elastic modulus and lattice structure) changes indicated weakening of the bones under space-like conditions of microgravity and radiation.

Intra-operative digital imaging: assuring the alignment of components when undertaking total hip arthroplasty.

PubMed

Hambright, D; Hellman, M; Barrack, R

2018-01-01

The aims of this study were to examine the rate at which the positioning of the acetabular component, leg length discrepancy and femoral offset are outside an acceptable range in total hip arthroplasties (THAs) which either do or do not involve the use of intra-operative digital imaging. A retrospective case-control study was undertaken with 50 patients before and 50 patients after the integration of an intra-operative digital imaging system in THA. The demographics of the two groups were comparable for body mass index, age, laterality and the indication for surgery. The digital imaging group had more men than the group without. Surgical data and radiographic parameters, including the inclination and anteversion of the acetabular component, leg length discrepancy, and the difference in femoral offset compared with the contralateral hip were collected and compared, as well as the incidence of altering the position of a component based on the intra-operative image. Digital imaging took a mean of five minutes (2.3 to 14.6) to perform. Intra-operative changes with the use of digital imaging were made for 43 patients (86%), most commonly to adjust leg length and femoral offset. There was a decrease in the incidence of outliers when using intra-operative imaging compared with not using it in regard to leg length discrepancy (20% versus 52%, p = 0.001) and femoral offset inequality (18% versus 44%, p = 0.004). There was also a difference in the incidence of outliers in acetabular inclination (0% versus 7%, p = 0.023) and version (0% versus 4%, p = 0.114) compared with historical results of a high-volume surgeon at the same centre. The use of intra-operative digital imaging in THA improves the accuracy of the positioning of the components at THA without adding a substantial amount of time to the operation. Cite this article: Bone Joint J 2018;100B(1 Supple A):36-43. ©2018 The British Editorial Society of Bone & Joint Surgery.

Biomechanics and strain mapping in bone as related to immediately-loaded dental implants

PubMed Central

Du, Jing; Lee, Jihyun; Jang, Andrew; Gu, Allen; Hossaini-Zadeh, Mehran; Prevost, Richard; Curtis, Don; Ho, Sunita

2015-01-01

The effects of alveolar bone socket geometry and bone-implant contact on implant biomechanics, and resulting strain distributions in bone were investigated. Following extraction of lateral incisors on a cadaver mandible, immediate implants were placed and bone-implant contact area, stability and bone strain were measured. In situ biomechanical testing coupled with micro X-ray microscope (μ-XRM) illustrated less stiff bone-implant complexes (701-822 N/mm) compared with bone-periodontal ligament (PDL)-tooth complexes (791-913 N/mm). X-ray tomograms illustrated that the cause of reduced stiffness was due to reduced and limited bone-implant contact. Heterogeneous elemental composition of bone was identified by using energy dispersive X-ray spectroscopy (EDS). The novel aspect of this study was the application of a new experimental mechanics method, that is, digital volume correlation, which allowed mapping of strains in volumes of alveolar bone in contact with a loaded implant. The identified surface and subsurface strain concentrations were a manifestation of load transferred to bone through bone-implant contact based on bone-implant geometry, quality of bone, implant placement, and implant design. 3D strain mapping indicated that strain concentrations are not exclusive to the bone-implant contact regions, but also extend into bone not directly in contact with the implant. The implications of the observed strain concentrations are discussed in the context of mechanobiology. Although a plausible explanation of surgical complications for immediate implant treatment is provided, extrapolation of results is only warranted by future systematic studies on more cadaver specimens and/or in vivo small scale animal models. PMID:26162549

Bone age assessment in Hispanic children: digital hand atlas compared with the Greulich and Pyle (G&P) atlas

NASA Astrophysics Data System (ADS)

Fernandez, James Reza; Zhang, Aifeng; Vachon, Linda; Tsao, Sinchai

2008-03-01

Bone age assessment is most commonly performed with the use of the Greulich and Pyle (G&P) book atlas, which was developed in the 1950s. The population of theUnited States is not as homogenous as the Caucasian population in the Greulich and Pyle in the 1950s, especially in the Los Angeles, California area. A digital hand atlas (DHA) based on 1,390 hand images of children of different racial backgrounds (Caucasian, African American, Hispanic, and Asian) aged 0-18 years was collected from Children's Hospital Los Angeles. Statistical analysis discovered significant discrepancies exist between Hispanic and the G&P atlas standard. To validate the usage of DHA as a clinical standard, diagnostic radiologists performed reads on Hispanic pediatric hand and wrist computed radiography images using either the G&P pediatric radiographic atlas or the Children's Hospital Los Angeles Digital Hand Atlas (DHA) as reference. The order in which the atlas is used (G&P followed by DHA or vice versa) for each image was prepared before actual reading begins. Statistical analysis of the results was then performed to determine if a discrepancy exists between the two readings.

Toward identifying specification requirements for digital bone-anchored prosthesis design incorporating substructure fabrication: a pilot study.

PubMed

Eggbeer, Dominic; Bibb, Richard; Evans, Peter

2006-01-01

This paper is the first in a series that aims to identify the specification requirements for advanced digital technologies that may be used to design and fabricate complex, soft tissue facial prostheses. Following a review of previously reported techniques, appropriate and currently available technologies were selected and applied in a pilot study. This study uses a range of optical surface scanning, computerized tomography, computer-aided design, and rapid prototyping technologies to capture, design, and fabricate a bone-anchored auricular prosthesis, including the retentive components. The techniques are assessed in terms of their effectiveness, and the results are used to identify future research and specification requirements to direct developments. The case study identifies that while digital technologies may be used to design implant-retained facial prostheses, many limitations need to be addressed to make the techniques clinically viable. It also identifies the need to develop a more robust specification that covers areas such as resolution, accuracy, materials, and design, against which potential technologies may be assessed. There is a need to develop a specification against which potential technologies may be assessed for their suitability in soft tissue facial prosthetics. The specification will be developed using further experimental research studies.

Influence of Screw Length and Bone Thickness on the Stability of Temporary Implants

PubMed Central

Fernandes, Daniel Jogaib; Elias, Carlos Nelson; Ruellas, Antônio Carlos de Oliveira

2015-01-01

The purpose of this work was to study the influence of screw length and bone thickness on the stability of temporary implants. A total of 96 self-drilling temporary screws with two different lengths were inserted into polyurethane blocks (n = 66), bovine femurs (n = 18) and rabbit tibia (n = 12) with different cortical thicknesses (1 to 8 mm). Screws insertion in polyurethane blocks was assisted by a universal testing machine, torque peaks were collected by a digital torquemeter and bone thickness was monitored by micro-CT. The results showed that the insertion torque was significantly increased with the thickness of cortical bone from polyurethane (p < 0.0001), bovine (p = 0.0035) and rabbit (p < 0.05) sources. Cancellous bone improved significantly the mechanical implant stability. Insertion torque and insertion strength was successfully moduled by equations, based on the cortical/cancellous bone behavior. Based on the results, insertion torque and bone strength can be estimate in order to prevent failure of the cortical layer during temporary screw placement. The stability provided by a cortical thickness of 2 or 1 mm coupled to cancellous bone was deemed sufficient for temporary implants stability. PMID:28793582

The osteoplastic effectiveness of the implants made of mesh titanium nickelide constructs

PubMed Central

Irianov, Iurii Mikhailovich; Diuriagina, Olga Vladimirovna; Karaseva, Tatiana Iurevna; Karasev, Evgenii Anatolevich

2014-01-01

The purpose of the work was to study the features of reparative osteogenesis for filling the defect of tubular bone under implantation of mesh titanium nickelide constructs. Tibial fenestrated defect was modeled experimentally in 30 Wistar pubertal rats, followed by implant intramedullary insertion. The techniques of radiography, scanning electron microscopy and X-ray electron probe microanalysis were used. The mesh implant of titanium nickelide has been established to possess biocompatibility, osteoconductive and osteoinductive properties, the zone of osteogenesis and angiogenesis is created around it, bone cover is formed. Osteointegration of the implant occurs early, by 7 days after surgery, and by 30 days after surgery organotypical re-modelling of the regenerated bone takes place, as well as the defect is filled with lamellar bone tissue by the type of bone wound primary adhesion. By 30 days after surgery mineral content of the regenerated bone tissue approximates to the composition of intact cortex mineral phase. PMID:24579962

Computed tomographic anatomy of the equine foot.

PubMed

Claerhoudt, S; Bergman, E H J; Saunders, J H

2014-10-01

This study describes a detailed computed tomographic reference of the normal equine foot. Ten forefeet of five adult cadavers, without evidence of orthopaedic disease, were used. Computed tomography (CT) was performed on all feet. Two-millimetre thick transverse slices were obtained, and sagittal and dorsal planes were reformatted. The CT images were matched with the corresponding anatomic slices. The phalanges and the distal sesamoid bone showed excellent detail. The extensor and flexor tendons (including their attachments) could be clearly evaluated. The collateral (sesamoidean) ligaments could be readily located, but were difficult to delineate at their proximal attachment. The distal digital annular ligament could only be distinguished from the deep digital flexor tendon proximal to the distal sesamoid bone, and its proximal attachment could be identified, but not its distal insertion. Small ligaments (impar ligament, chondrosesamoidean, chondrocoronal and chondrocompedal ligaments, axial and abaxial palmar ligaments of the proximal inter-phalangeal joint) were seen with difficulty and not at all slices. The joint capsules could not be delineated from the surrounding soft tissue structures. The lateral and medial proprius palmar digital artery and vein could be visualized occasionally on some slices. The ungular cartilages, corium and hoof wall layering were seen. The nerves, the articular and fibrocartilage of the distal sesamoid bone and the chondroungular ligament could not be assessed. Computed tomography of the equine foot can be of great value when results of radiography and ultrasonography are inconclusive. Images obtained in this study may serve as reference for CT of the equine foot. © 2013 Blackwell Verlag GmbH.

Knee Images Digital Analysis (KIDA): a novel method to quantify individual radiographic features of knee osteoarthritis in detail.

PubMed

Marijnissen, A C A; Vincken, K L; Vos, P A J M; Saris, D B F; Viergever, M A; Bijlsma, J W J; Bartels, L W; Lafeber, F P J G

2008-02-01

Radiography is still the golden standard for imaging features of osteoarthritis (OA), such as joint space narrowing, subchondral sclerosis, and osteophyte formation. Objective assessment, however, remains difficult. The goal of the present study was to evaluate a novel digital method to analyse standard knee radiographs. Standardized radiographs of 20 healthy and 55 OA knees were taken in general practise according to the semi-flexed method by Buckland-Wright. Joint Space Width (JSW), osteophyte area, subchondral bone density, joint angle, and tibial eminence height were measured as continuous variables using newly developed Knee Images Digital Analysis (KIDA) software on a standard PC. Two observers evaluated the radiographs twice, each on two different occasions. The observers were blinded to the source of the radiographs and to their previous measurements. Statistical analysis to compare measurements within and between observers was performed according to Bland and Altman. Correlations between KIDA data and Kellgren & Lawrence (K&L) grade were calculated and data of healthy knees were compared to those of OA knees. Intra- and inter-observer variations for measurement of JSW, subchondral bone density, osteophytes, tibial eminence, and joint angle were small. Significant correlations were found between KIDA parameters and K&L grade. Furthermore, significant differences were found between healthy and OA knees. In addition to JSW measurement, objective evaluation of osteophyte formation and subchondral bone density is possible on standard radiographs. The measured differences between OA and healthy individuals suggest that KIDA allows detection of changes in time, although sensitivity to change has to be demonstrated in long-term follow-up studies.

ELECTRONIC DIGITAL COMPUTER

DOEpatents

Stone, J.J. Jr.; Bettis, E.S.; Mann, E.R.

1957-10-01

The electronic digital computer is designed to solve systems involving a plurality of simultaneous linear equations. The computer can solve a system which converges rather rapidly when using Von Seidel's method of approximation and performs the summations required for solving for the unknown terms by a method of successive approximations.

Early fixation of cobalt-chromium based alloy surgical implants to bone using a tissue-engineering approach.

PubMed

Ogawa, Munehiro; Tohma, Yasuaki; Ohgushi, Hajime; Takakura, Yoshinori; Tanaka, Yasuhito

2012-01-01

To establish the methods of demonstrating early fixation of metal implants to bone, one side of a Cobalt-Chromium (CoCr) based alloy implant surface was seeded with rabbit marrow mesenchymal cells and the other side was left unseeded. The mesenchymal cells were further cultured in the presence of ascorbic acid, β-glycerophosphate and dexamethasone, resulting in the appearance of osteoblasts and bone matrix on the implant surface. Thus, we succeeded in generating tissue-engineered bone on one side of the CoCr implant. The CoCr implants were then implanted in rabbit bone defects. Three weeks after the implantation, evaluations of mechanical test, undecalcified histological section and electron microscope analysis were performed. Histological and electron microscope images of the tissue engineered surface exhibited abundant new bone formation. However, newly formed bone tissue was difficult to detect on the side without cell seeding. In the mechanical test, the mean values of pull-out forces were 77.15 N and 44.94 N for the tissue-engineered and non-cell-seeded surfaces, respectively. These findings indicate early bone fixation of the tissue-engineered CoCr surface just three weeks after implantation.

Early Fixation of Cobalt-Chromium Based Alloy Surgical Implants to Bone Using a Tissue-engineering Approach

PubMed Central

Ogawa, Munehiro; Tohma, Yasuaki; Ohgushi, Hajime; Takakura, Yoshinori; Tanaka, Yasuhito

2012-01-01

To establish the methods of demonstrating early fixation of metal implants to bone, one side of a Cobalt-Chromium (CoCr) based alloy implant surface was seeded with rabbit marrow mesenchymal cells and the other side was left unseeded. The mesenchymal cells were further cultured in the presence of ascorbic acid, β-glycerophosphate and dexamethasone, resulting in the appearance of osteoblasts and bone matrix on the implant surface. Thus, we succeeded in generating tissue-engineered bone on one side of the CoCr implant. The CoCr implants were then implanted in rabbit bone defects. Three weeks after the implantation, evaluations of mechanical test, undecalcified histological section and electron microscope analysis were performed. Histological and electron microscope images of the tissue engineered surface exhibited abundant new bone formation. However, newly formed bone tissue was difficult to detect on the side without cell seeding. In the mechanical test, the mean values of pull-out forces were 77.15 N and 44.94 N for the tissue-engineered and non-cell-seeded surfaces, respectively. These findings indicate early bone fixation of the tissue-engineered CoCr surface just three weeks after implantation. PMID:22754313

Electronic simulation of a barometric pressure sensor for the meteorological monitor assembly

NASA Technical Reports Server (NTRS)

Guiar, C. N.; Duff, L. W.

1982-01-01

An analysis of the electronic simulation of barometric pressure used to self-test the counter electronics of the digital barometer is presented. The barometer is part of the Meteorological Monitor Assembly that supports navigation in deep space communication. The theory of operation of the digital barometer, the design details, and the verification procedure used with the barometric pressure simulator are presented.

Fractal-like hierarchical organization of bone begins at the nanoscale

NASA Astrophysics Data System (ADS)

Reznikov, Natalie; Bilton, Matthew; Lari, Leonardo; Stevens, Molly M.; Kröger, Roland

2018-05-01

The components of bone assemble hierarchically to provide stiffness and toughness. However, the organization and relationship between bone’s principal components—mineral and collagen—has not been clearly elucidated. Using three-dimensional electron tomography imaging and high-resolution two-dimensional electron microscopy, we demonstrate that bone mineral is hierarchically assembled beginning at the nanoscale: Needle-shaped mineral units merge laterally to form platelets, and these are further organized into stacks of roughly parallel platelets. These stacks coalesce into aggregates that exceed the lateral dimensions of the collagen fibrils and span adjacent fibrils as continuous, cross-fibrillar mineralization. On the basis of these observations, we present a structural model of hierarchy and continuity for the mineral phase, which contributes to the structural integrity of bone.

Digital Economy and Management in Spain.

ERIC Educational Resources Information Center

del Aguila, Ana R.; Padilla, Antonio; Serarols, Christian; Veciana, Jose M.

2003-01-01

Explains the digital economy and its impact on the firm. Highlights include subsectors of the digital economy, including infrastructure; analysis of the digital economy in Spain; analysis of the ICT (information and communication technology) sector in Spain; and electronic commerce through the Internet. (LRW)

Skeletal status and soft tissue composition in astronauts. Tissue and fluid changes by radionuclide absorptiometry in vivo

NASA Technical Reports Server (NTRS)

Cameron, J. R.; Mazess, R. B.; Wilson, C. R.

1973-01-01

A device has been constructed and tested which provides immediate readout of bone mineral content and bone width from absorptiometric scans with low energy radionuclides. The basis of this analog system is a logarithmic converter-integrator coupled with a precision linear ratemeter. The system provided accurate and reliable results on standards and ashed bone sections. Clinical measurements were made on about 100 patients with the direct readout system, and these were highly correlated with the results from digital scan data on the same patients. The direct readout system has been used successfully in field studies and surveys as well as for clinical observations.

Optically-synchronized encoder and multiplexer scheme for interleaved photonics analog-to-digital conversion

NASA Astrophysics Data System (ADS)

Villa, Carlos; Kumavor, Patrick; Donkor, Eric

2008-04-01

Photonics Analog-to-Digital Converters (ADCs) utilize a train of optical pulses to sample an electrical input waveform applied to an electrooptic modulator or a reverse biased photodiode. In the former, the resulting train of amplitude-modulated optical pulses is detected (converter to electrical) and quantized using a conversional electronics ADC- as at present there are no practical, cost-effective optical quantizers available with performance that rival electronic quantizers. In the latter, the electrical samples are directly quantized by the electronics ADC. In both cases however, the sampling rate is limited by the speed with which the electronics ADC can quantize the electrical samples. One way to increase the sampling rate by a factor N is by using the time-interleaved technique which consists of a parallel array of N electrical ADC converters, which have the same sampling rate but different sampling phase. Each operating at a quantization rate of fs/N where fs is the aggregated sampling rate. In a system with no real-time operation, the N channels digital outputs are stored in memory, and then aggregated (multiplexed) to obtain the digital representation of the analog input waveform. Alternatively, for real-time operation systems the reduction of storing time in the multiplexing process is desired to improve the time response of the ADC. The complete elimination of memories come expenses of concurrent timing and synchronization in the aggregation of the digital signal that became critical for a good digital representation of the analog signal waveform. In this paper we propose and demonstrate a novel optically synchronized encoder and multiplexer scheme for interleaved photonics ADCs that utilize the N optical signals used to sample different phases of an analog input signal to synchronize the multiplexing of the resulting N digital output channels in a single digital output port. As a proof of concept, four 320 Megasamples/sec 12-bit of resolution digital signals were multiplexed to form an aggregated 1.28 Gigasamples/sec single digital output signal.

Production of microscale particles from fish bone by gas flow assisted laser ablation

NASA Astrophysics Data System (ADS)

Boutinguiza, M.; Lusquiños, F.; Comesaña, R.; Riveiro, A.; Quintero, F.; Pou, J.

2007-12-01

Recycled wastes from fish and seafood can constitute a source of precursor material for different applications in the biomedical field such as bone fillers or precursor material for bioceramic coatings to improve the osteointegration of metallic implants. In this work, fish bones have been used directly as target in a laser ablation system. A pulsed Nd:YAG laser was used to ablate the fish bone material and a transverse air flow was used to extract the ablated material out of the interaction zone. The particles collected at a filter were in the micro and nanoscale range. The morphology as well as the composition of the obtained particles were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The results reveal that the composition of the analyzed particles is similar to that of the inorganic part of the fish bone.

Morphological and chemical analysis of bone substitutes by scanning electron microscopy and microanalysis by spectroscopy of dispersion energy.

PubMed

da Cruz, Gabriela Alessandra; de Toledo, Sérgio; Sallum, Enilson Antonio; de Lima, Antonio Fernando Martorelli

2007-01-01

This study evaluated the morphological and chemical composition of the following bone substitutes: cancellous and cortical organic bovine bone with macro and microparticle size ranging from 1.0 to 2.0 mm and 0.25 to 1.0 mm, respectively; inorganic bovine bone with particle size ranging from 0.25 to 1.0 mm; hydroxyapatite with particle size ranging from 0.75 to 1.0 mm; and demineralized freeze-dried bone allograft with particle size ranging from 0.25 to 0.5 mm. The samples were sputter-coated with gold in an ion coater, the morphology was observed and particle size was measured under vacuum by scanning electron microscopy (SEM). The chemical composition was evaluated by spectroscopy of dispersion energy (EDS) microanalysis using samples without coating. SEM analysis provided visual evidence that all examined materials have irregular shape and particle sizes larger than those informed by the manufacturer. EDS microanalysis detected the presence of sodium, calcium and phosphorus that are usual elements of the bone tissue. However, mineral elements were detected in all analyzed particles of organic bovine bone except for macro cancellous organic bovine bone. These results suggest that the examined organic bovine bone cannot be considered as a pure organic material.

Uncovering Information Hidden in Web Archives: Glimpse at Web Analysis Building on Data Warehouses; Towards Continuous Web Archiving: First Results and an Agenda for the Future; The Open Video Digital Library; After Migration to an Electronic Journal Collection: Impact on Faculty and Doctoral Students; Who Is Reading On-Line Education Journals? Why? And What Are They Reading?; Report on eLibrary@UBC4: Research, Collaboration and the Digital Library - Visions for 2010.

ERIC Educational Resources Information Center

Rauber, Andreas; Bruckner, Robert M.; Aschenbrenner, Andreas; Witvoet, Oliver; Kaiser, Max; Masanes, Julien; Marchionini, Gary; Geisler, Gary; King, Donald W.; Montgomery, Carol Hansen; Rudner, Lawrence M.; Gellmann, Jennifer S.; Miller-Whitehead, Marie; Iverson, Lee

2002-01-01

These six articles discuss Web archives and Web analysis building on data warehouses; international efforts at continuous Web archiving; the Open Video Digital Library; electronic journal collections in academic libraries; online education journals; and an electronic library symposium at the University of British Columbia. (LRW)

Peri-implant bone strains and micro-motion following in vivo service: a postmortem retrieval study of 22 tibial components from total knee replacements.

PubMed

Mann, Kenneth A; Miller, Mark A; Goodheart, Jacklyn R; Izant, Timothy H; Cleary, Richard J

2014-03-01

Biological adaptation following placement of a total knee replacements (TKRs) affects peri-implant bone mineral density (BMD) and implant fixation. We quantified the proximal tibial bone strain and implant-bone micro-motion for functioning postmortem retrieved TKRs and assessed the strain/micro-motion relationships with chronological (donor age and time in service) and patient (body weight and BMD) factors. Twenty-two tibial constructs were functionally loaded to one body weight (60% medial/40% lateral), and the bone strains and tray/bone micro-motions were measured using a digital image correlation system. Donors with more time in service had higher bone strains (p = 0.044), but there was not a significant (p = 0.333) contribution from donor age. Donors with lower peri-implant BMD (p = 0.0039) and higher body weight (p = 0.0286) had higher bone strains. Long term implants (>11 years) had proximal bone strains 900 µϵ that were almost twice as high as short term (<5 years) implants 570 µϵ. Micro-motion was greater for younger donors (p = 0.0161) and longer time in service (p = 0.0008). Increased bone strain with long term in vivo service could contribute to loosening of TKRs by failure of the tibial peri-implant bone. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Diagnostic Accuracy of Cone-beam Computed Tomography and Conventional Radiography on Apical Periodontitis: A Systematic Review and Meta-analysis.

PubMed

Leonardi Dutra, Kamile; Haas, Letícia; Porporatti, André Luís; Flores-Mir, Carlos; Nascimento Santos, Juliana; Mezzomo, Luis André; Corrêa, Márcio; De Luca Canto, Graziela

2016-03-01

Endodontic diagnosis depends on accurate radiographic examination. Assessment of the location and extent of apical periodontitis (AP) can influence treatment planning and subsequent treatment outcomes. Therefore, this systematic review and meta-analysis assessed the diagnostic accuracy of conventional radiography and cone-beam computed tomographic (CBCT) imaging on the discrimination of AP from no lesion. Eight electronic databases with no language or time limitations were searched. Articles in which the primary objective was to evaluate the accuracy (sensitivity and specificity) of any type of radiographic technique to assess AP in humans were selected. The gold standard was the histologic examination for actual AP (in vivo) or in situ visualization of bone defects for induced artificial AP (in vitro). Accuracy measurements described in the studies were transformed to construct receiver operating characteristic curves and forest plots with the aid of Review Manager v.5.2 (The Nordic Cochrane Centre, Copenhagen, Denmark) and MetaDisc v.1.4. software (Unit of Clinical Biostatistics Team of the Ramón y Cajal Hospital, Madrid, Spain). The methodology of the selected studies was evaluated using the Quality Assessment Tool for Diagnostic Accuracy Studies-2. Only 9 studies met the inclusion criteria and were subjected to a qualitative analysis. A meta-analysis was conducted on 6 of these articles. All of these articles studied artificial AP with induced bone defects. The accuracy values (area under the curve) were 0.96 for CBCT imaging, 0.73 for conventional periapical radiography, and 0.72 for digital periapical radiography. No evidence was found for panoramic radiography. Periapical radiographs (digital and conventional) reported good diagnostic accuracy on the discrimination of artificial AP from no lesions, whereas CBCT imaging showed excellent accuracy values. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The effect of total knee arthroplasty on body weight.

PubMed

Lee, Gwo-Chin; Cushner, Fred D; Cannella, Laura Y; Scott, W Norman

2005-03-01

This prospective study quantified the weight change in 20 consecutive patients undergoing total knee arthroplasty. Resected bone, soft tissues, and bone reamings were collected during surgery and weighed using a digital scale at the end of the procedure. Results were compared to the cumulative weights of the prosthesis, bone cement, patellar component, and polyethylene liner. Average weight of the resected bone and soft tissues was 167.71 g for men and 130.13 g for women. Mean weight of the implanted prosthesis and cement used was 509.92 g for men and 422.56 g for women. Men tended to receive a larger-sized prosthesis than women. Overall, the average weight gain as a result of knee arthroplasty was 345.54 g for men and 292.44 g for women. This translates to an insignificant increase in body weight.

A STUDY OF PREDICTED BONE MARROW DISTRIBUTION ON CALCULATED MARROW DOSE FROM EXTERNAL RADIATION EXPOSURES USING TWO SETS OF IMAGE DATA FOR THE SAME INDIVIDUAL

PubMed Central

Caracappa, Peter F.; Chao, T. C. Ephraim; Xu, X. George

2010-01-01

Red bone marrow is among the tissues of the human body that are most sensitive to ionizing radiation, but red bone marrow cannot be distinguished from yellow bone marrow by normal radiographic means. When using a computational model of the body constructed from computed tomography (CT) images for radiation dose, assumptions must be applied to calculate the dose to the red bone marrow. This paper presents an analysis of two methods of calculating red bone marrow distribution: 1) a homogeneous mixture of red and yellow bone marrow throughout the skeleton, and 2) International Commission on Radiological Protection cellularity factors applied to each bone segment. A computational dose model was constructed from the CT image set of the Visible Human Project and compared to the VIP-Man model, which was derived from color photographs of the same individual. These two data sets for the same individual provide the unique opportunity to compare the methods applied to the CT-based model against the observed distribution of red bone marrow for that individual. The mass of red bone marrow in each bone segment was calculated using both methods. The effect of the different red bone marrow distributions was analyzed by calculating the red bone marrow dose using the EGS4 Monte Carlo code for parallel beams of monoenergetic photons over an energy range of 30 keV to 6 MeV, cylindrical (simplified CT) sources centered about the head and abdomen over an energy range of 30 keV to 1 MeV, and a whole-body electron irradiation treatment protocol for 3.9 MeV electrons. Applying the method with cellularity factors improves the average difference in the estimation of mass in each bone segment as compared to the mass in VIP-Man by 45% over the homogenous mixture method. Red bone marrow doses calculated by the two methods are similar for parallel photon beams at high energy (above about 200 keV), but differ by as much as 40% at lower energies. The calculated red bone marrow doses differ significantly for simplified CT and electron beam irradiation, since the computed red bone marrow dose is a strong function of the cellularity factor applied to bone segments within the primary radiation beam. These results demonstrate the importance of properly applying realistic cellularity factors to computation dose models of the human body. PMID:19430219

A study of predicted bone marrow distribution on calculated marrow dose from external radiation exposures using two sets of image data for the same individual.

PubMed

Caracappa, Peter F; Chao, T C Ephraim; Xu, X George

2009-06-01

Red bone marrow is among the tissues of the human body that are most sensitive to ionizing radiation, but red bone marrow cannot be distinguished from yellow bone marrow by normal radiographic means. When using a computational model of the body constructed from computed tomography (CT) images for radiation dose, assumptions must be applied to calculate the dose to the red bone marrow. This paper presents an analysis of two methods of calculating red bone marrow distribution: 1) a homogeneous mixture of red and yellow bone marrow throughout the skeleton, and 2) International Commission on Radiological Protection cellularity factors applied to each bone segment. A computational dose model was constructed from the CT image set of the Visible Human Project and compared to the VIP-Man model, which was derived from color photographs of the same individual. These two data sets for the same individual provide the unique opportunity to compare the methods applied to the CT-based model against the observed distribution of red bone marrow for that individual. The mass of red bone marrow in each bone segment was calculated using both methods. The effect of the different red bone marrow distributions was analyzed by calculating the red bone marrow dose using the EGS4 Monte Carlo code for parallel beams of monoenergetic photons over an energy range of 30 keV to 6 MeV, cylindrical (simplified CT) sources centered about the head and abdomen over an energy range of 30 keV to 1 MeV, and a whole-body electron irradiation treatment protocol for 3.9 MeV electrons. Applying the method with cellularity factors improves the average difference in the estimation of mass in each bone segment as compared to the mass in VIP-Man by 45% over the homogenous mixture method. Red bone marrow doses calculated by the two methods are similar for parallel photon beams at high energy (above about 200 keV), but differ by as much as 40% at lower energies. The calculated red bone marrow doses differ significantly for simplified CT and electron beam irradiation, since the computed red bone marrow dose is a strong function of the cellularity factor applied to bone segments within the primary radiation beam. These results demonstrate the importance of properly applying realistic cellularity factors to computation dose models of the human body.

47 CFR 36.125 - Local switching equipment-Category 3.

Code of Federal Regulations, 2010 CFR

2010-10-01

... electronic analog or digital remote line locations. Equipment used for the identification, recording and... which has a common intermediate distributing frame, market group or other separately identifiable... composed of an electronic analog or digital host office and all of its remote locations. A host/remote...

21 CFR 1305.03 - Distributions requiring a Form 222 or a digitally signed electronic order.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Distributions requiring a Form 222 or a digitally signed electronic order. Either a DEA Form 222 or its... laboratory or its agent approved by DEA. (d) Delivery from a central fill pharmacy, as defined in § 1300.01(b...

21 CFR 1305.03 - Distributions requiring a Form 222 or a digitally signed electronic order.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Distributions requiring a Form 222 or a digitally signed electronic order. Either a DEA Form 222 or its... laboratory or its agent approved by DEA. (d) Delivery from a central fill pharmacy, as defined in § 1300.01(b...

Osteointegration of porous absorbable bone substitutes: A systematic review of the literature.

PubMed

Paulo, Maria Júlia Escanhoela; Dos Santos, Mariana Avelino; Cimatti, Bruno; Gava, Nelson Fabrício; Riberto, Marcelo; Engel, Edgard Eduard

2017-07-01

Biomaterials' structural characteristics and the addition of osteoinductors influence the osteointegration capacity of bone substitutes. This study aims to identify the characteristics of porous and resorbable bone substitutes that influence new bone formation. An Internet search for studies reporting new bone formation rates in bone defects filled with porous and resorbable substitutes was performed in duplicate using the PubMed, Web of Science, Scielo, and University of São Paulo Digital Library databases. Metaphyseal or calvarial bone defects 4 to 10 mm in diameter from various animal models were selected. New bone formation rates were collected from the histomorphometry or micro-CT data. The following variables were analyzed: animal model, bone region, defect diameter, follow-up time after implantation, basic substitute material, osteoinductor addition, pore size and porosity. Of 3,266 initially identified articles, 15 articles describing 32 experimental groups met the inclusion criteria. There were no differences between the groups in the experimental model characteristics, except for the follow-up time, which showed a very weak to moderate correlation with the rate of new bone formation. In terms of the biomaterial and structural characteristics, only porosity showed a significant influence on the rate of new bone formation. Higher porosity is related to higher new bone formation rates. The influence of other characteristics could not be identified, possibly due to the large variety of experimental models and methodologies used to estimate new bone formation rates. We suggest the inclusion of standard control groups in future experimental studies to compare biomaterials.

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

Merchant, Bion J.

The Seismo-Hydroacoustic Data Acquisition System (SHDAS) is undergoing evaluation in preparation for its engineering, development, and deployment by the U.S Navy as an ocean bottom seismic monitoring system. At the current stage of development, the production digitizers are being evaluated to confirm their performance prior to packaging and assembly for deployment. The testing of the digitizers is being conducted at Delta Group Electronics, the digitizer fabricator, in San Diego, California, performed by Sandia National Laboratories with the assistance of Leidos and Delta Group Electronics.

Designed cell consortia as fragrance-programmable analog-to-digital converters.

PubMed

Müller, Marius; Ausländer, Simon; Spinnler, Andrea; Ausländer, David; Sikorski, Julian; Folcher, Marc; Fussenegger, Martin

2017-03-01

Synthetic biology advances the rational engineering of mammalian cells to achieve cell-based therapy goals. Synthetic gene networks have nearly reached the complexity of digital electronic circuits and enable single cells to perform programmable arithmetic calculations or to provide dynamic remote control of transgenes through electromagnetic waves. We designed a synthetic multilayered gaseous-fragrance-programmable analog-to-digital converter (ADC) allowing for remote control of digital gene expression with 2-bit AND-, OR- and NOR-gate logic in synchronized cell consortia. The ADC consists of multiple sampling-and-quantization modules sensing analog gaseous fragrance inputs; a gas-to-liquid transducer converting fragrance intensity into diffusible cell-to-cell signaling compounds; a digitization unit with a genetic amplifier circuit to improve the signal-to-noise ratio; and recombinase-based digital expression switches enabling 2-bit processing of logic gates. Synthetic ADCs that can remotely control cellular activities with digital precision may enable the development of novel biosensors and may provide bioelectronic interfaces synchronizing analog metabolic pathways with digital electronics.

Tissue Engineering Whole Bones Through Endochondral Ossification: Regenerating the Distal Phalanx.

PubMed

Sheehy, Eamon J; Mesallati, Tariq; Kelly, Lara; Vinardell, Tatiana; Buckley, Conor T; Kelly, Daniel J

2015-01-01

Novel strategies are urgently required to facilitate regeneration of entire bones lost due to trauma or disease. In this study, we present a novel framework for the regeneration of whole bones by tissue engineering anatomically shaped hypertrophic cartilaginous grafts in vitro that subsequently drive endochondral bone formation in vivo. To realize this, we first fabricated molds from digitized images to generate mesenchymal stem cell-laden alginate hydrogels in the shape of different bones (the temporomandibular joint [TMJ] condyle and the distal phalanx). These constructs could be stimulated in vitro to generate anatomically shaped hypertrophic cartilaginous tissues that had begun to calcify around their periphery. Constructs were then formed into the shape of the distal phalanx to create the hypertrophic precursor of the osseous component of an engineered long bone. A layer of cartilage engineered through self-assembly of chondrocytes served as the articular surface of these constructs. Following chondrogenic priming and subcutaneous implantation, the hypertrophic phase of the engineered phalanx underwent endochondral ossification, leading to the generation of a vascularized bone integrated with a covering layer of stable articular cartilage. Furthermore, spatial bone deposition within the construct could be modulated by altering the architecture of the osseous component before implantation. These findings open up new horizons to whole limb regeneration by recapitulating key aspects of normal bone development.

The radiographic trabecular pattern of hips in patients with hip fractures and in elderly control subjects.

PubMed

Geraets, W G; Van der Stelt, P F; Lips, P; Van Ginkel, F C

1998-02-01

Due to the increasing number of osteoporotic fractures of hip, spine, and wrist there is a growing need for methods to track down the subjects with inferior bone structure and to monitor the effects of therapeutic measures. This study aims at a noninvasive diagnostic tool, deriving architectural properties of trabecular bone from in vivo measurements on plane radiographic films. Pelvic radiographs of the nonfractured hips of 81 patients with hip fractures and of the right hips of 74 controls were studied. The regions of interest, 2 x 2 cm2, located in the femoral neck, were sampled and digitized with a video camera connected to an image analysis system. Several geometrical and directional measurements were made. The measurements were evaluated by statistical comparison with fracture risk, gender, and Singh index. By discriminant analysis, type of fracture, as well as gender and Singh index could be predicted correctly for 58% of the subjects, whereas guessing would be correct in only 8%. It was found that the geometrical parameters discriminate between hips of controls and patients. With respect to the directional measurements associations were found with gender and Singh index. Although the new parameters assess fracture risk less accurately than bone density measurements, some parameters suggest by their behavior that they are relevant with respect to femoral bone architecture and its mechanical behavior. Although interpretation of the measurements in histological concepts requires methods that have been reported in literature only recently, it is concluded that digital analysis of the radiographic trabecular pattern is an interesting option to increase the diagnostic yield of plane film radiographs and to study the structure of bone in vivo.

Feasibility of using an inversion-recovery ultrashort echo time (UTE) sequence for quantification of glenoid bone loss.

PubMed

Ma, Ya-Jun; West, Justin; Nazaran, Amin; Cheng, Xin; Hoenecke, Heinz; Du, Jiang; Chang, Eric Y

2018-02-02

To utilize the 3D inversion recovery prepared ultrashort echo time with cones readout (IR-UTE-Cones) MRI technique for direct imaging of lamellar bone with comparison to the gold standard of computed tomography (CT). CT and MRI was performed on 11 shoulder specimens and three patients. Five specimens had imaging performed before and after glenoid fracture (osteotomy). 2D and 3D volume-rendered CT images were reconstructed and conventional T1-weighted and 3D IR-UTE-Cones MRI techniques were performed. Glenoid widths and defects were independently measured by two readers using the circle method. Measurements were compared with those made from 3D CT datasets. Paired-sample Student's t tests and intraclass correlation coefficients were performed. In addition, 2D CT and 3D IR-UTE-Cones MRI datasets were linearly registered, digitally overlaid, and compared in consensus by these two readers. Compared with the reference standard (3D CT), glenoid bone diameter measurements made on 2D CT and 3D IR-UTE-Cones were not significantly different for either reader, whereas T1-weighted images underestimated the diameter (mean difference of 0.18 cm, p = 0.003 and 0.16 cm, p = 0.022 for readers 1 and 2, respectively). However, mean margin of error for measuring glenoid bone loss was small for all modalities (range, 1.46-3.92%). All measured ICCs were near perfect. Digitally registered 2D CT and 3D IR-UTE-Cones MRI datasets yielded essentially perfect congruity between the two modalities. The 3D IR-UTE-Cones MRI technique selectively visualizes lamellar bone, produces similar contrast to 2D CT imaging, and compares favorably to measurements made using 2D and 3D CT.

Trabecular bone characterization on the continuum of plates and rods using in vivo MR imaging and volumetric topological analysis

NASA Astrophysics Data System (ADS)

Chen, Cheng; Jin, Dakai; Liu, Yinxiao; Wehrli, Felix W.; Chang, Gregory; Snyder, Peter J.; Regatte, Ravinder R.; Saha, Punam K.

2016-09-01

Osteoporosis is associated with increased risk of fractures, which is clinically defined by low bone mineral density. Increasing evidence suggests that trabecular bone (TB) micro-architecture is an important determinant of bone strength and fracture risk. We present an improved volumetric topological analysis algorithm based on fuzzy skeletonization, results of its application on in vivo MR imaging, and compare its performance with digital topological analysis. The new VTA method eliminates data loss in the binarization step and yields accurate and robust measures of local plate-width for individual trabeculae, which allows classification of TB structures on the continuum between perfect plates and rods. The repeat-scan reproducibility of the method was evaluated on in vivo MRI of distal femur and distal radius, and high intra-class correlation coefficients between 0.93 and 0.97 were observed. The method’s ability to detect treatment effects on TB micro-architecture was examined in a 2 years testosterone study on hypogonadal men. It was observed from experimental results that average plate-width and plate-to-rod ratio significantly improved after 6 months and the improvement was found to continue at 12 and 24 months. The bone density of plate-like trabeculae was found to increase by 6.5% (p  =  0.06), 7.2% (p  =  0.07) and 16.2% (p  =  0.003) at 6, 12, 24 months, respectively. While the density of rod-like trabeculae did not change significantly, even at 24 months. A comparative study showed that VTA has enhanced ability to detect treatment effects in TB micro-architecture as compared to conventional method of digital topological analysis for plate/rod characterization in terms of both percent change and effect-size.

Software Defined Radio (SDR) and Direct Digital Synthesizer (DDS) for NMR/MRI instruments at low-field.

PubMed

Asfour, Aktham; Raoof, Kosai; Yonnet, Jean-Paul

2013-11-27

A proof-of-concept of the use of a fully digital radiofrequency (RF) electronics for the design of dedicated Nuclear Magnetic Resonance (NMR) systems at low-field (0.1 T) is presented. This digital electronics is based on the use of three key elements: a Direct Digital Synthesizer (DDS) for pulse generation, a Software Defined Radio (SDR) for a digital receiving of NMR signals and a Digital Signal Processor (DSP) for system control and for the generation of the gradient signals (pulse programmer). The SDR includes a direct analog-to-digital conversion and a Digital Down Conversion (digital quadrature demodulation, decimation filtering, processing gain…). The various aspects of the concept and of the realization are addressed with some details. These include both hardware design and software considerations. One of the underlying ideas is to enable such NMR systems to "enjoy" from existing advanced technology that have been realized in other research areas, especially in telecommunication domain. Another goal is to make these systems easy to build and replicate so as to help research groups in realizing dedicated NMR desktops for a large palette of new applications. We also would like to give readers an idea of the current trends in this field. The performances of the developed electronics are discussed throughout the paper. First FID (Free Induction Decay) signals are also presented. Some development perspectives of our work in the area of low-field NMR/MRI will be finally addressed.

Melorheostosis: case report with 20-year follow-up.

PubMed

Pavone, Vito; Evola, Roberto Francesco; Di Giorgio, Angelo; Ruggieri, Martino; Ardito, Salvatore

2008-05-01

The authors report on a typical case of melorheostosis observed in an 18-year-old man, localized in the II digit of the right hand causing tumefaction and irregular pain. At 20-year follow-up, the patient showed a radiographical slight worsening of the lesion. Radiographic examination showed a mild increase in cortical and endosteal hyperostosis with bone shape alteration in the II digit of the right hand, slight cortical and endosteal hyperostosis at the level of right shoulder girdle involving the humerus. The other part of the skeleton was not affected. Clinical examination revealed swelling and tumefaction of the forefinger of the right hand and reduced articular motion both in proximal and distal interphalangeal joint and metacarpal phalangeal joint. The reminder of the clinical examination was normal. Melorheostosis is an uncommon mesenchymal disorder characterized by a chondral hyperostosis of the long bones associated to a sclerosis of the spongious bone. The etiology of this affection is unknown: the most accredited hypothesis is a developmental anomaly with a sequential sclerotomes distribution. Both genders may be affected, with the long tubular bones of the lower limbs more involved. This anomaly is often asymptomatic but maybe accompanied by pain with a smooth symptom progression and periodic exacerbations. Therapy is mainly symptomatic and comprises anti-inflammatory drugs or surgical approach for removal of soft tissue that may preclude daily activities. This case report demonstrates that melorheostosis is a relatively benign disorder with mildly progressive course.

An image-based skeletal dosimetry model for the ICRP reference adult male—internal electron sources

NASA Astrophysics Data System (ADS)

Hough, Matthew; Johnson, Perry; Rajon, Didier; Jokisch, Derek; Lee, Choonsik; Bolch, Wesley

2011-04-01

In this study, a comprehensive electron dosimetry model of the adult male skeletal tissues is presented. The model is constructed using the University of Florida adult male hybrid phantom of Lee et al (2010 Phys. Med. Biol. 55 339-63) and the EGSnrc-based Paired Image Radiation Transport code of Shah et al (2005 J. Nucl. Med. 46 344-53). Target tissues include the active bone marrow, associated with radiogenic leukemia, and total shallow marrow, associated with radiogenic bone cancer. Monoenergetic electron emissions are considered over the energy range 1 keV to 10 MeV for the following sources: bone marrow (active and inactive), trabecular bone (surfaces and volumes), and cortical bone (surfaces and volumes). Specific absorbed fractions are computed according to the MIRD schema, and are given as skeletal-averaged values in the paper with site-specific values reported in both tabular and graphical format in an electronic annex available from http://stacks.iop.org/0031-9155/56/2309/mmedia. The distribution of cortical bone and spongiosa at the macroscopic dimensions of the phantom, as well as the distribution of trabecular bone and marrow tissues at the microscopic dimensions of the phantom, is imposed through detailed analyses of whole-body ex vivo CT images (1 mm resolution) and spongiosa-specific ex vivo microCT images (30 µm resolution), respectively, taken from a 40 year male cadaver. The method utilized in this work includes: (1) explicit accounting for changes in marrow self-dose with variations in marrow cellularity, (2) explicit accounting for electron escape from spongiosa, (3) explicit consideration of spongiosa cross-fire from cortical bone, and (4) explicit consideration of the ICRP's change in the surrogate tissue region defining the location of the osteoprogenitor cells (from a 10 µm endosteal layer covering the trabecular and cortical surfaces to a 50 µm shallow marrow layer covering trabecular and medullary cavity surfaces). Skeletal-averaged values of absorbed fraction in the present model are noted to be very compatible with those weighted by the skeletal tissue distributions found in the ICRP Publication 110 adult male and female voxel phantoms, but are in many cases incompatible with values used in current and widely implemented internal dosimetry software.

Social Work in a Digital Age: Ethical and Risk Management Challenges

ERIC Educational Resources Information Center

Reamer, Frederic G.

2013-01-01

Digital, online, and other electronic technology has transformed the nature of social work practice. Contemporary social workers can provide services to clients by using online counseling, telephone counseling, video counseling, cybertherapy (avatar therapy), self-guided Web-based interventions, electronic social networks, e-mail, and text…

The Acquisition and Management of Electronic Resources: Can Use Justify Cost?

ERIC Educational Resources Information Center

Koehn, Shona L.; Hawamdeh, Suliman

2010-01-01

As library collections increasingly become digital, libraries are faced with many challenges regarding the acquisition and management of electronic resources. Some of these challenges include copyright and fair use, the first-sale doctrine, licensing versus ownership, digital preservation, long-term archiving, and, most important, the issue of…

The Art of Electronics

NASA Astrophysics Data System (ADS)

Horowitz, Paul; Hill, Winfield

2015-04-01

1. Foundations; 2. Bipolar transistors; 3. Field effect transistors; 4. Operational amplifiers; 5. Precision circuits; 6. Filters; 7. Oscillators and timers; 8. Low noise techniques and transimpedance; 9. Power regulation; 10. Digital electronics; 11. Programmable logic devices; 12. Logical interfacing; 13. Digital meets analog; 14. Computers, controllers, and data links; 15. Microcontrollers.

76 FR 25706 - Notice of Receipt of Complaint; Solicitation of Comments Relating to the Public Interest

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-05

... Certain Electronic Devices Having a Digital Television Receiver and Components Thereof, DN 2801; the... importation of certain electronic devices having a digital television receiver and components thereof. The... health and welfare in the United States, competitive conditions in the United States economy, the...

76 FR 12994 - In the Matter of Certain Digital Televisions and Components Thereof, and Certain Electronic...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-09

... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-764] In the Matter of Certain Digital Televisions and Components Thereof, and Certain Electronic Devices Having a Blu-Ray Disc Player and Components Thereof; Notice of Investigation AGENCY: U.S. International Trade Commission. ACTION: Institution of...

Using PBL to Deliver Course in Digital Electronics

ERIC Educational Resources Information Center

Mantri, Archana; Dutt, Sunil; Gupta, J. P; Chitkara, Madhu

2009-01-01

Problem Based Learning (PBL) has proven to be a highly successful pedagogical model in many educational fields, although it is comparatively uncommon in technical education. It goes beyond the typical teaching methodology by promoting student interaction. This paper presents a PBL trial applied to an undergraduate Digital Electronics course in the…

36 CFR 1235.44 - What general transfer requirements apply to electronic records?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Services Division (NWCS) for digital photographs, 8601 Adelphi Road, College Park, MD 20740, phone number..., Electronic/Special Media Records Services Division (NWME), 8601 Adelphi Road, College Park, MD 20740, phone number (301) 837-3420. (c) When transferring digital photographs and their accompanying metatdata, the...

36 CFR 1235.44 - What general transfer requirements apply to electronic records?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Services Division (NWCS) for digital photographs, 8601 Adelphi Road, College Park, MD 20740, phone number..., Electronic/Special Media Records Services Division (NWME), 8601 Adelphi Road, College Park, MD 20740, phone number (301) 837-3420. (c) When transferring digital photographs and their accompanying metatdata, the...

Industrial Electronics II for ICT. Student's Manual.

ERIC Educational Resources Information Center

Snider, Bob

This student manual contains the following six units for classroom and laboratory experiences in high school industrial electronics: (1) introduction and review of DC and AC circuits; (2) semiconductors; (3) integrated circuits; (4) digital basics; (5) complex digital circuits; and (6) computer circuits. The units include unit objectives, specific…

General-purpose readout electronics for white neutron source at China Spallation Neutron Source

NASA Astrophysics Data System (ADS)

Wang, Q.; Cao, P.; Qi, X.; Yu, T.; Ji, X.; Xie, L.; An, Q.

2018-01-01

The under-construction White Neutron Source (WNS) at China Spallation Neutron Source is a facility for accurate measurements of neutron-induced cross section. Seven spectrometers are planned at WNS. As the physical objectives of each spectrometer are different, the requirements for readout electronics are not the same. In order to simplify the development of the readout electronics, this paper presents a general method for detector signal readout. This method has advantages of expansibility and flexibility, which makes it adaptable to most detectors at WNS. In the WNS general-purpose readout electronics, signals from any kinds of detectors are conditioned by a dedicated signal conditioning module corresponding to this detector, and then digitized by a common waveform digitizer with high speed and high precision (1 GSPS at 12-bit) to obtain the full waveform data. The waveform digitizer uses a field programmable gate array chip to process the data stream and trigger information in real time. PXI Express platform is used to support the functionalities of data readout, clock distribution, and trigger information exchange between digitizers and trigger modules. Test results show that the performance of the WNS general-purpose readout electronics can meet the requirements of the WNS spectrometers.

Identification of resident and inflammatory bone marrow derived cells in the sclera by bone marrow and haematopoietic stem cell transplantation

PubMed Central

Hisatomi, Toshio; Sonoda, Koh‐hei; Ishikawa, Fumihiko; Qiao, Hong; Nakamura, Takahiro; Fukata, Mitsuhiro; Nakazawa, Toru; Noda, Kousuke; Miyahara, Shinsuke; Harada, Mine; Kinoshita, Shigeru; Hafezi‐Moghadam, Ali; Ishibashi, Tatsuro; Miller, Joan W

2007-01-01

Aims To characterise bone marrow derived cells in the sclera under normal and inflammatory conditions, we examined their differentiation after transplantation from two different sources, bone marrow and haematopoietic stem cells (HSC). Methods Bone marrow and HSC from green fluorescent protein (GFP) transgenic mice were transplanted into irradiated wild‐type mice. At 1 month after transplantation, mice were sacrificed and their sclera examined by histology, immunohistochemistry (CD11b, CD11c, CD45), and transmission and scanning electron microscopy. To investigate bone marrow derived cell recruitment under inflammatory conditions, experimental autoimmune uveitis (EAU) was induced in transplanted mice. Results GFP positive cells were distributed in the entire sclera and comprised 22.4 (2.8)% (bone marrow) and 28.4 (10.9)% (HSC) of the total cells in the limbal zone and 18.1 (6.7)% (bone marrow) and 26.3 (3.4)% (HSC) in the peripapillary zone. Immunohistochemistry showed that GFP (+) CD11c (+), GFP (+) CD11b (+) cells migrated in the sclera after bone marrow and HSC transplantation. Transmission and scanning electron microscopy revealed antigen presenting cells among the scleral fibroblasts. In EAU mice, vast infiltration of GFP (+) cells developed into the sclera. Conclusion We have provided direct and novel evidence for the migration of bone marrow and HSC cells into the sclera differentiating into macrophages and dendritic cells. Vast infiltration of bone marrow and HSC cells was found to be part of the inflammatory process in EAU. PMID:17035278

Rhinoceros Feet Step Out of a Rule-of-Thumb: A Wildlife Imaging Pioneering Approach of Synchronized Computed Tomography-Digital Radiography

PubMed Central

Saragusty, Joseph; Göritz, Frank; Potier, Romain; Mulot, Baptiste; Maillot, Alexis; Etienne, Pascal; Bernardino, Rui; Fernandes, Teresa; Mews, Jurgen; Hildebrandt, Thomas Bernd

2014-01-01

Currently, radiography is the only imaging technique used to diagnose bone pathology in wild animals situated under “field conditions”. Nevertheless, while chronic foot disease in captive mega-herbivores is widely reported, foot radiographic imaging is confronted with scarcity of studies. Numerous hindrances lead to such limited numbers and it became very clear that the traditional perspective on bone imaging in domestic animals based on extensive studies and elaborated statistical evaluations cannot be extrapolated to their non-domestic relatives. For these reasons, the authors initiated a multi-modality imaging study and established a pioneering approach of synchronized computed tomography (CT) and digital radiography (DR), based on X-ray projections derived from three-dimensional CT reconstructed images. Whereas this approach can be applied in any clinical field, as a case of outstanding importance and great concern for zoological institutions, we selected foot bone pathologies in captive rhinoceroses to demonstrate the manifold applications of the method. Several advances were achieved, endowing the wildlife clinician with all-important tools: prototype DR exposure protocols and a modus operandi for foot positioning, advancing both traditional projections and, for the first-time, species-related radiographic views; assessment of radiographic diagnostic value for the whole foot and, in premiere, for each autopodial bone; together with additional insights into radiographic appearance of bone anatomy and pathology with a unique, simultaneous CT-DR correlation. Based on its main advantages in availing a wide range of keystone data in wildlife imaging from a limited number of examined subjects and combining advantages of CT as the golden standard method for bone diseases' diagnostic with DR's clinical feasibility under field conditions, synchronized CT-DR presents a new perspective on wildlife's health management. With this we hope to provide veterinary clinicians with concrete imaging techniques and substantial diagnostic tools, which facilitate straightforward attainment and interpretation of field radiography images taken worldwide. PMID:24963807

Rhinoceros feet step out of a rule-of-thumb: a wildlife imaging pioneering approach of synchronized computed tomography-digital radiography.

PubMed

Galateanu, Gabriela; Hermes, Robert; Saragusty, Joseph; Göritz, Frank; Potier, Romain; Mulot, Baptiste; Maillot, Alexis; Etienne, Pascal; Bernardino, Rui; Fernandes, Teresa; Mews, Jurgen; Hildebrandt, Thomas Bernd

2014-01-01

Currently, radiography is the only imaging technique used to diagnose bone pathology in wild animals situated under "field conditions". Nevertheless, while chronic foot disease in captive mega-herbivores is widely reported, foot radiographic imaging is confronted with scarcity of studies. Numerous hindrances lead to such limited numbers and it became very clear that the traditional perspective on bone imaging in domestic animals based on extensive studies and elaborated statistical evaluations cannot be extrapolated to their non-domestic relatives. For these reasons, the authors initiated a multi-modality imaging study and established a pioneering approach of synchronized computed tomography (CT) and digital radiography (DR), based on X-ray projections derived from three-dimensional CT reconstructed images. Whereas this approach can be applied in any clinical field, as a case of outstanding importance and great concern for zoological institutions, we selected foot bone pathologies in captive rhinoceroses to demonstrate the manifold applications of the method. Several advances were achieved, endowing the wildlife clinician with all-important tools: prototype DR exposure protocols and a modus operandi for foot positioning, advancing both traditional projections and, for the first-time, species-related radiographic views; assessment of radiographic diagnostic value for the whole foot and, in premiere, for each autopodial bone; together with additional insights into radiographic appearance of bone anatomy and pathology with a unique, simultaneous CT-DR correlation. Based on its main advantages in availing a wide range of keystone data in wildlife imaging from a limited number of examined subjects and combining advantages of CT as the golden standard method for bone diseases' diagnostic with DR's clinical feasibility under field conditions, synchronized CT-DR presents a new perspective on wildlife's health management. With this we hope to provide veterinary clinicians with concrete imaging techniques and substantial diagnostic tools, which facilitate straightforward attainment and interpretation of field radiography images taken worldwide.

Composition and structure of porcine digital flexor tendon-bone insertion tissues.

PubMed

Chandrasekaran, Sandhya; Pankow, Mark; Peters, Kara; Huang, Hsiao-Ying Shadow

2017-11-01

Tendon-bone insertion is a functionally graded tissue, transitioning from 200 MPa tensile modulus at the tendon end to 20 GPa tensile modulus at the bone, across just a few hundred micrometers. In this study, we examine the porcine digital flexor tendon insertion tissue to provide a quantitative description of its collagen orientation and mineral concentration by using Fast Fourier Transform (FFT) based image analysis and mass spectrometry, respectively. Histological results revealed uniformity in global collagen orientation at all depths, indicative of mechanical anisotropy, although at mid-depth, the highest fiber density, least amount of dispersion, and least cellular circularity were evident. Collagen orientation distribution obtained through 2D FFT of histological imaging data from fluorescent microscopy agreed with past measurements based on polarized light microscopy. Results revealed global fiber orientation across the tendon-bone insertion to be preserved along direction of physiologic tension. Gradation in the fiber distribution orientation index across the insertion was reflective of a decrease in anisotropy from the tendon to the bone. We provided elemental maps across the fibrocartilage for its organic and inorganic constituents through time-of-flight secondary ion mass spectrometry (TOF-SIMS). The apatite intensity distribution from the tendon to bone was shown to follow a linear trend, supporting past results based on Raman microprobe analysis. The merit of this study lies in the image-based simplified approach to fiber distribution quantification and in the high spatial resolution of the compositional analysis. In conjunction with the mechanical properties of the insertion tissue, fiber, and mineral distribution results for the insertion from this may potentially be incorporated into the development of a structural constitutive approach toward computational modeling. Characterizing the properties of the native insertion tissue would provide the microstructural basis for developing biomimetic scaffolds to recreate the graded morphology of a fibrocartilaginous insertion. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3050-3058, 2017. © 2017 Wiley Periodicals, Inc.

Measurement of absorbed dose with a bone-equivalent extrapolation chamber.

PubMed

DeBlois, François; Abdel-Rahman, Wamied; Seuntjens, Jan P; Podgorsak, Ervin B

2002-03-01

A hybrid phantom-embedded extrapolation chamber (PEEC) made of Solid Water and bone-equivalent material was used for determining absorbed dose in a bone-equivalent phantom irradiated with clinical radiation beams (cobalt-60 gamma rays; 6 and 18 MV x rays; and 9 and 15 MeV electrons). The dose was determined with the Spencer-Attix cavity theory, using ionization gradient measurements and an indirect determination of the chamber air-mass through measurements of chamber capacitance. The collected charge was corrected for ionic recombination and diffusion in the chamber air volume following the standard two-voltage technique. Due to the hybrid chamber design, correction factors accounting for scatter deficit and electrode composition were determined and applied in the dose equation to obtain absorbed dose in bone for the equivalent homogeneous bone phantom. Correction factors for graphite electrodes were calculated with Monte Carlo techniques and the calculated results were verified through relative air cavity dose measurements for three different polarizing electrode materials: graphite, steel, and brass in conjunction with a graphite collecting electrode. Scatter deficit, due mainly to loss of lateral scatter in the hybrid chamber, reduces the dose to the air cavity in the hybrid PEEC in comparison with full bone PEEC by 0.7% to approximately 2% depending on beam quality and energy. In megavoltage photon and electron beams, graphite electrodes do not affect the dose measurement in the Solid Water PEEC but decrease the cavity dose by up to 5% in the bone-equivalent PEEC even for very thin graphite electrodes (<0.0025 cm). In conjunction with appropriate correction factors determined with Monte Carlo techniques, the uncalibrated hybrid PEEC can be used for measuring absorbed dose in bone material to within 2% for high-energy photon and electron beams.

Subchondral architecture in bones of the canine shoulder.

PubMed Central

Simkin, P A; Heston, T F; Downey, D J; Benedict, R S; Choi, H S

1991-01-01

The distal scapula and proximal humerus from each shoulder of nine adult dogs were slab-sectioned, cleaned of soft tissues, embedded in white plastic and stained black with a silver stain. These preparations were then photographed for automated, digital, morphometric analysis of subchondral bone structure. Comparison of transverse and coronal sections through the left and right shoulders demonstrated essential isometry of trabecular patterns within each bone. Comparison of the scapula and humerus revealed significant differences in bony architecture. The subchondral plate was an average of 5.6 times thicker under the glenoid fossa than in the opposing humeral head. Deeper trabecular structure also differed with the trabecular bone volume (density) in the humerus being greater than that in the scapula. This difference reflects a greater trabecular density in the humerus with comparable trabecular thickness in both bones. These structural differences are consistent with previous functional studies of the same two bones that revealed greater mechanical stiffness beneath the glenoid fossa and greater hydraulic resistance within the humeral head. Images Fig. 1 Fig. 2 (cont.) Fig. 2 Fig. 3 PMID:2050567

Sex determination using discriminant analysis of upper and lower extremity bones: New approach using the volume and surface area of digital model.

PubMed

Lee, U-Young; Kim, In-Beom; Kwak, Dai-Soon

2015-08-01

This study used 110 CT images taken from donated Korean cadavers to create 3-D models of the following upper and lower limb bones: the clavicle, scapula, humerus, radius, ulna, hip bone (os coxa), femur, patella (knee cap), tibia, talus, and calcaneus. In addition, the bone volume and surface area were calculated to determine sex differences using discriminant analysis. Significant sex differences were found in all bones with respect to volume and surface area (p<0.01). The order of volume was the same in females and males (femur>hip bone>tibia>humerus>scapula), although the order of surface area was different. The largest surface area in men was the femur and in women was the hip bone (p<0.01). An interesting finding of this study was that the ulna is the bone with the highest accuracy for sex determination (94%). When using the surface area of multiple bones, the maximum accuracy (99.4%) was achieved. The equation was as follows: (discriminant equation of surface area; female<0

Postnatal temporal bone ontogeny in Pan, Gorilla, and Homo, and the implications for temporal bone ontogeny in Australopithecus afarensis.

PubMed

Terhune, Claire E; Kimbel, William H; Lockwood, Charles A

2013-08-01

Assessments of temporal bone morphology have played an important role in taxonomic and phylogenetic evaluations of fossil taxa, and recent three-dimensional analyses of this region have supported the utility of the temporal bone for testing taxonomic and phylogenetic hypotheses. But while clinical analyses have examined aspects of temporal bone ontogeny in humans, the ontogeny of the temporal bone in non-human taxa is less well documented. This study examines ontogenetic allometry of the temporal bone in order to address several research questions related to the pattern and trajectory of temporal bone shape change during ontogeny in the African apes and humans. We further apply these data to a preliminary analysis of temporal bone ontogeny in Australopithecus afarensis. Three-dimensional landmarks were digitized on an ontogenetic series of specimens of Homo sapiens, Pan troglodytes, Pan paniscus, and Gorilla gorilla. Data were analyzed using geometric morphometric methods, and shape changes throughout ontogeny in relation to size were compared. Results of these analyses indicate that, despite broadly similar patterns, African apes and humans show marked differences in development of the mandibular fossa and tympanic portions of the temporal bone. These findings indicate divergent, rather than parallel, postnatal ontogenetic allometric trajectories for temporal bone shape in these taxa. The pattern of temporal bone shape change with size exhibited by A. afarensis showed some affinities to that of humans, but was most similar to extant African apes, particularly Gorilla. Copyright © 2013 Wiley Periodicals, Inc.

Back-scattered electron imaging of a non-vertebral case of hypervitaminosis A in a cat.

PubMed

Franch, J; Pastor, J; Franch, B; Durall, I; Manzanares, M C

2000-03-01

We describe a clinical case of hypervitaminosis A in a cat. The main lesions were bony fusions of both the hip and stifle joints, without spinal involvement. A post-mortem study using back-scattered scanning electron microscopy (BEI-SEM) revealed that exostoses had formed around the joints without articular surface involvement. The more recently formed areas of bony proliferation were composed mainly of chondroid tissue surrounded by different degrees of woven bone. As the bony reaction occurred, remodelling of the trabeculae was observed which lead to progressive substitution of chondroid tissue by woven bone surrounded by apposition of lamellar bone. No traces of calcified cartilage were observed in any of the bone sections evaluated. Copyright 2000 European Society of Feline Medicine.

European roadmap on superconductive electronics - status and perspectives

NASA Astrophysics Data System (ADS)

Anders, S.; Blamire, M. G.; Buchholz, F.-Im.; Crété, D.-G.; Cristiano, R.; Febvre, P.; Fritzsch, L.; Herr, A.; Il'ichev, E.; Kohlmann, J.; Kunert, J.; Meyer, H.-G.; Niemeyer, J.; Ortlepp, T.; Rogalla, H.; Schurig, T.; Siegel, M.; Stolz, R.; Tarte, E.; ter Brake, H. J. M.; Toepfer, H.; Villegier, J.-C.; Zagoskin, A. M.; Zorin, A. B.

2010-12-01

Executive SummaryFor four decades semiconductor electronics has followed Moore’s law: with each generation of integration the circuit features became smaller, more complex and faster. This development is now reaching a wall so that smaller is no longer any faster. The clock rate has saturated at about 3-5 GHz and the parallel processor approach will soon reach its limit. The prime reason for the limitation the semiconductor electronics experiences is not the switching speed of the individual transistor, but its power dissipation and thus heat. Digital superconductive electronics is a circuit- and device-technology that is inherently faster at much less power dissipation than semiconductor electronics. It makes use of superconductors and Josephson junctions as circuit elements, which can provide extremely fast digital devices in a frequency range - dependent on the material - of hundreds of GHz: for example a flip-flop has been demonstrated that operated at 750 GHz. This digital technique is scalable and follows similar design rules as semiconductor devices. Its very low power dissipation of only 0.1 μW per gate at 100 GHz opens the possibility of three-dimensional integration. Circuits like microprocessors and analogue-to-digital converters for commercial and military applications have been demonstrated. In contrast to semiconductor circuits, the operation of superconducting circuits is based on naturally standardized digital pulses the area of which is exactly the flux quantum Φ0. The flux quantum is also the natural quantization unit for digital-to-analogue and analogue-to-digital converters. The latter application is so precise, that it is being used as voltage standard and that the physical unit ‘Volt’ is defined by means of this standard. Apart from its outstanding features for digital electronics, superconductive electronics provides also the most sensitive sensor for magnetic fields: the Superconducting Quantum Interference Device (SQUID). Amongst many other applications SQUIDs are used as sensors for magnetic heart and brain signals in medical applications, as sensor for geological surveying and food-processing and for non-destructive testing. As amplifiers of electrical signals, SQUIDs can nearly reach the theoretical limit given by Quantum Mechanics. A further important field of application is the detection of very weak signals by ‘transition-edge’ bolometers, superconducting nanowire single-photon detectors, and superconductive tunnel junctions. Their application as radiation detectors in a wide frequency range, from microwaves to X-rays is now standard. The very low losses of superconductors have led to commercial microwave filter designs that are now widely used in the USA in base stations for cellular phones and in military communication applications. The number of demonstrated applications is continuously increasing and there is no area in professional electronics, in which superconductive electronics cannot be applied and surpasses the performance of classical devices. Superconductive electronics has to be cooled to very low temperatures. Whereas this was a bottleneck in the past, cooling techniques have made a huge step forward in recent years: very compact systems with high reliability and a wide range of cooling power are available commercially, from microcoolers of match-box size with milli-Watt cooling power to high-reliability coolers of many Watts of cooling power for satellite applications. Superconductive electronics will not replace semiconductor electronics and similar room-temperature techniques in standard applications, but for those applications which require very high speed, low-power consumption, extreme sensitivity or extremely high precision, superconductive electronics is superior to all other available techniques. To strengthen the European competitiveness in superconductor electronics research projects have to be set-up in the following field: Ultra-sensitive sensing and imaging. Quantum measurement instrumentation. Advanced analogue-to-digital converters. Superconductive electronics technology.

Registering 2D and 3D imaging data of bone during healing.

PubMed

Hoerth, Rebecca M; Baum, Daniel; Knötel, David; Prohaska, Steffen; Willie, Bettina M; Duda, Georg N; Hege, Hans-Christian; Fratzl, Peter; Wagermaier, Wolfgang

2015-04-01

PURPOSE/AIMS OF THE STUDY: Bone's hierarchical structure can be visualized using a variety of methods. Many techniques, such as light and electron microscopy generate two-dimensional (2D) images, while micro-computed tomography (µCT) allows a direct representation of the three-dimensional (3D) structure. In addition, different methods provide complementary structural information, such as the arrangement of organic or inorganic compounds. The overall aim of the present study is to answer bone research questions by linking information of different 2D and 3D imaging techniques. A great challenge in combining different methods arises from the fact that they usually reflect different characteristics of the real structure. We investigated bone during healing by means of µCT and a couple of 2D methods. Backscattered electron images were used to qualitatively evaluate the tissue's calcium content and served as a position map for other experimental data. Nanoindentation and X-ray scattering experiments were performed to visualize mechanical and structural properties. We present an approach for the registration of 2D data in a 3D µCT reference frame, where scanning electron microscopies serve as a methodic link. Backscattered electron images are perfectly suited for registration into µCT reference frames, since both show structures based on the same physical principles. We introduce specific registration tools that have been developed to perform the registration process in a semi-automatic way. By applying this routine, we were able to exactly locate structural information (e.g. mineral particle properties) in the 3D bone volume. In bone healing studies this will help to better understand basic formation, remodeling and mineralization processes.

Structure‐function relationships at the human spinal disc‐vertebra interface

PubMed Central

Berg‐Johansen, Britta; Fields, Aaron J.; Liebenberg, Ellen C.; Li, Alfred

2017-01-01

ABSTRACT Damage at the intervertebral disc‐vertebra interface associates with back pain and disc herniation. However, the structural and biomechanical properties of the disc‐vertebra interface remain underexplored. We sought to measure mechanical properties and failure mechanisms, quantify architectural features, and assess structure‐function relationships at this vulnerable location. Vertebra‐disc‐vertebra specimens from human cadaver thoracic spines were scanned with micro‐computed tomography (μCT), surface speckle‐coated, and loaded to failure in uniaxial tension. Digital image correlation (DIC) was used to calculate local surface strains. Failure surfaces were scanned using scanning electron microscopy (SEM), and adjacent sagittal slices were analyzed with histology and SEM. Seventy‐one percent of specimens failed initially at the cartilage endplate‐bone interface of the inner annulus region. Histology and SEM both indicated a lack of structural integration between the cartilage endplate (CEP) and bone. The interface failure strength was increased in samples with higher trabecular bone volume fraction in the vertebral endplates. Furthermore, failure strength decreased with degeneration, and in discs with thicker CEPs. Our findings indicate that poor structural connectivity between the CEP and vertebra may explain the structural weakness at this region, and provide insight into structural features that may contribute to risk for disc‐vertebra interface injury. The disc‐vertebra interface is the site of failure in the majority of herniation injuries. Here we show new structure‐function relationships at this interface that may motivate the development of diagnostics, prevention strategies, and treatments to improve the prognosis for many low back pain patients with disc‐vertebra interface injuries. © 2017 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 36:192–201, 2018. PMID:28590060

The effect of rigid fixation on growth of the neurocranium.

PubMed

Wong, L; Dufresne, C R; Richtsmeier, J T; Manson, P N

1991-09-01

The effects on skull growth of plating the coronal suture and frontal bone were studied in New Zealand White rabbits. Three-dimensional coordinate landmarks were digitized and analyzed to determine the differences in form between operated and unoperated animals using Euclidian distance matrix analysis. This method compares sets of interlandmark distances in three dimensions and was used to demonstrate changes induced by plating. We interpret these changes in morphology to be the result of differences in growth between the operated and unoperated groups. Periosteal elevation alone (n = 6) resulted in a minimal local growth increase. Coronal suture plating (n = 8) resulted in local growth restriction with contralateral and adjacent size increases. Frontal bone plating (n = 6) without crossing a suture line also resulted in local growth restriction and adjacent bone size increases. The timing of intervention in relation to the completion of bone growth may explain the magnitude of clinically apparent effects. Changes in bones adjacent to those directly manipulated may be an attempt to maintain a normal skull volume.

Analogous cellular contribution and healing mechanisms following digit amputation and phalangeal fracture in mice

PubMed Central

Dawson, Lindsay A.; Simkin, Jennifer; Sauque, Michelle; Pela, Maegan; Palkowski, Teresa

2016-01-01

Abstract Regeneration of amputated structures is severely limited in humans and mice, with complete regeneration restricted to the distal portion of the terminal phalanx (P3). Here, we investigate the dynamic tissue repair response of the second phalangeal element (P2) post amputation in the adult mouse, and show that the repair response of the amputated bone is similar to the proximal P2 bone fragment in fracture healing. The regeneration‐incompetent P2 amputation response is characterized by periosteal endochondral ossification resulting in the deposition of new trabecular bone, corresponding to a significant increase in bone volume; however, this response is not associated with bone lengthening. We show that cells of the periosteum respond to amputation and fracture by contributing both chondrocytes and osteoblasts to the endochondral ossification response. Based on our studies, we suggest that the amputation response represents an attempt at regeneration that ultimately fails due to the lack of a distal organizing influence that is present in fracture healing. PMID:27499878

Radiation Damage and Single Event Effect Results for Candidate Spacecraft Electronics

NASA Technical Reports Server (NTRS)

OBryan, Martha V.; LaBel, Kenneth A.; Reed, Robert A.; Howard, James W., Jr.; Ladbury, Ray L.; Barth, Janet L.; Kniffin, Scott D.; Seidleck, Christina M.; Marshall, Paul W.; Marshall, Cheryl J.;

Quiet Clean Short-haul Experimental Engine (QCSEE) over-the-wing control system design report

NASA Technical Reports Server (NTRS)

1977-01-01

A control system incorporating a digital electronic control was designed for the over-the-wing engine. The digital electronic control serves as the primary controlling element for engine fuel flow and core compressor stator position. It also includes data monitoring capability, a unique failure indication and corrective action feature, and optional provisions for operating with a new type of servovalve designed to operate in response to a digital-type signal and to fail with its output device hydraulically locked into position.

Poster - Thur Eve - 69: Electron beam dosimetry in heterogeneous phantoms using the MAGIC normoxic polymer gel.

PubMed

Nedaie, H A; Ghahraman, A R; Bolouri, B; Arbabi, A

2012-07-01

Recently, radiation sensitive polymer gels are being used as a reliable dosimetry method for three-dimensional (3D) verification of radiation doses in clinical use. Some properties of gel dosimeters have made them useful in verifying complex situations in electron therapy. The aim of this study was to experimentally evaluate the influence of tissue inhomogeneities on electron beam dose distributions by use of polymer gel dosimetry. Another purpose was to evaluate the appropriateness of polymer gels for electron beam dosimetry applications. A cylindrical phantom filled with MAGIC polymer gel with a polyacrilic wall (ρ = 1.18 g.cm -3 ) was placed in a Perspex water-filled tank exactly underneath the bone inhomogeneity region .Then, the slab phantom was irradiated with a dose of 5Gy of 8MeV electrons to measure the dose distribution beyond the heterogeneity region. Afterwards, another cylindrical gel phantom similar to the above was used and irradiated with the same dose of 15 MeV electrons to measure the dose distribution beyond the same heterogeneity region. The same mentioned setup was repeated for measurement of the dose distribution beneath the air heterogeneity and homogenous phantom. The results of gel dosimetry under bone inhomogeneity have shown a reduction in dose. This is related to the high mass stopping and mass scattering powers of bone tissue. In addition, dose enhancement is seen laterally near the bone-tissue interface, due to increased side scattering of electrons. Hot and cold scatter lobes under heterogeneity regions are other effects that can be seen. The results of gel dosimetry under the air inhomogeneity have shown an increase in dose. This is related to the low mass stopping and mass scattering powers of the air cavity. When a high energy beam passes through a low-density medium or an air cavity, electronic equilibrium is lost along the central axis of the beam .The dose rebuild up is a consequence of this electronic disequilibrium. An overall good agreement was found between measurements with gel and with a diode detector for the single beam experiment. Electron dose distributions are significantly altered in the presence of tissue inhomogeneities such as bone and air cavities which are related to mass stopping and mass scattering powers of heterogeneous materials. © 2012 American Association of Physicists in Medicine.

Digital Electronics for Nuclear Physics Experiments

NASA Astrophysics Data System (ADS)

Skulski, Wojtek; Hunter, David; Druszkiewicz, Eryk; Khaitan, Dev Ashish; Yin, Jun; Wolfs, Frank; SkuTek Instrumentation Team; Department of Physics; Astronomy, University of Rochester Team

2015-10-01

Future detectors in nuclear physics will use signal sampling as one of primary techniques of data acquisition. Using the digitized waveforms, the electronics can select events based on pulse shape, total energy, multiplicity, and the hit pattern. The DAQ for the LZ Dark Matter detector, now under development in Rochester, is a good example of the power of digital signal processing. This system, designed around 32-channel, FPGA-based, digital signal processors collects data from more than one thousand channels. The solutions developed for this DAQ can be applied to nuclear physics experiments. Supported by the Department of Energy Office of Science under Grant DE-SC0009543.

Flight test of a full authority Digital Electronic Engine Control system in an F-15 aircraft

NASA Technical Reports Server (NTRS)

Barrett, W. J.; Rembold, J. P.; Burcham, F. W.; Myers, L.

1981-01-01

The Digital Electronic Engine Control (DEEC) system considered is a relatively low cost digital full authority control system containing selectively redundant components and fault detection logic with capability for accommodating faults to various levels of operational capability. The DEEC digital control system is built around a 16-bit, 1.2 microsecond cycle time, CMOS microprocessor, microcomputer system with approximately 14 K of available memory. Attention is given to the control mode, component bench testing, closed loop bench testing, a failure mode and effects analysis, sea-level engine testing, simulated altitude engine testing, flight testing, the data system, cockpit, and real time display.

Development of the HIDEC inlet integration mode. [Highly Integrated Digital Electronic Control

NASA Technical Reports Server (NTRS)

Chisholm, J. D.; Nobbs, S. G.; Stewart, J. F.

1990-01-01

The Highly Integrated Digital Electronic Control (HIDEC) development program conducted at NASA-Ames/Dryden will use an F-15 test aircraft for flight demonstration. An account is presently given of the HIDEC Inlet Integration mode's design concept, control law, and test aircraft implementation, with a view to its performance benefits. The enhancement of performance is a function of the use of Digital Electronic Engine Control corrected engine airflow computations to improve the scheduling of inlet ramp positions in real time; excess thrust can thereby be increased by 13 percent at Mach 2.3 and 40,000 ft. Aircraft supportability is also improved through the obviation of inlet controllers.

Ultrasonography of the distal limbs in Nellore and Girolando calves 8 to 12 months of age

PubMed Central

2014-01-01

Background Ultrasonography can be used anywhere and allows rapid, noninvasive differentiation of soft tissue structures of the musculoskeletal system. The objectives of this study were to describe the ultrasonographic appearance of the structures of the metacarpo-/metatarsophalangeal and the interphalangeal joints, the appearance of the growth plates of the distal metacarpus/metatarsus and of the proximal phalanx and to measure the cross-sectional dimensions of the DDFT and SDFT in Nellore and Girolando calves eight to 12 months of age. Results In the longitudinal dorsal view the common digital extensor tendon and the digital extensor tendon were depicted as echogenic parallel fiber bundles located directly under the skin. The joint spaces appeared as anechoic interruptions of the hyperechogenic bone surfaces. The normal amount of synovial fluid could not be depicted. The growth plates were seen as anechoic interruptions of the bone surface proximal and distal to the fetlock joint space. In transverse sonograms of the distal palmar/plantar regions, the flexor tendons and branchs of the suspensory ligament were imaged as echogenic structures. The lumen of the digital flexor tendon sheath could not be imaged in these normal cattle. The thin digital distal annular ligament and the reversal of positions of the DDFT and SDFT could be appreciated. No significant differences were found between the cross-sectional measurements of the DDFT and the SDFT from Nellore and Girolando in any age, thoracic/pelvic limbs, right/left sides and lateral/medial digits. Conclusions The results of this study establish important ultrasonographic reference data of the normal structures of the distal limbs and the normal dimensions of the flexor tendons in Nellore and Girolando calves for use in clinical practice. PMID:24774582

Errors in quantitative backscattered electron analysis of bone standardized by energy-dispersive x-ray spectrometry.

PubMed

Vajda, E G; Skedros, J G; Bloebaum, R D

1998-10-01

Backscattered electron (BSE) imaging has proven to be a useful method for analyzing the mineral distribution in microscopic regions of bone. However, an accepted method of standardization has not been developed, limiting the utility of BSE imaging for truly quantitative analysis. Previous work has suggested that BSE images can be standardized by energy-dispersive x-ray spectrometry (EDX). Unfortunately, EDX-standardized BSE images tend to underestimate the mineral content of bone when compared with traditional ash measurements. The goal of this study is to investigate the nature of the deficit between EDX-standardized BSE images and ash measurements. A series of analytical standards, ashed bone specimens, and unembedded bone specimens were investigated to determine the source of the deficit previously reported. The primary source of error was found to be inaccurate ZAF corrections to account for the organic phase of the bone matrix. Conductive coatings, methylmethacrylate embedding media, and minor elemental constituents in bone mineral introduced negligible errors. It is suggested that the errors would remain constant and an empirical correction could be used to account for the deficit. However, extensive preliminary testing of the analysis equipment is essential.

Superconductor Digital-RF Receiver Systems

NASA Astrophysics Data System (ADS)

Mukhanov, Oleg A.; Kirichenko, Dmitri; Vernik, Igor V.; Filippov, Timur V.; Kirichenko, Alexander; Webber, Robert; Dotsenko, Vladimir; Talalaevskii, Andrei; Tang, Jia Cao; Sahu, Anubhav; Shevchenko, Pavel; Miller, Robert; Kaplan, Steven B.; Sarwana, Saad; Gupta, Deepnarayan

Digital superconductor electronics has been experiencing rapid maturation with the emergence of smaller-scale, lower-cost communications applications which became the major technology drivers. These applications are primarily in the area of wireless communications, radar, and surveillance as well as in imaging and sensor systems. In these areas, the fundamental advantages of superconductivity translate into system benefits through novel Digital-RF architectures with direct digitization of wide band, high frequency radio frequency (RF) signals. At the same time the availability of relatively small 4K cryocoolers has lowered the foremost market barrier for cryogenically-cooled digital electronic systems. Recently, we have achieved a major breakthrough in the development, demonstration, and successful delivery of the cryocooled superconductor digital-RF receivers directly digitizing signals in a broad range from kilohertz to gigahertz. These essentially hybrid-technology systems combine a variety of superconductor and semiconductor technologies packaged with two-stage commercial cryocoolers: cryogenic Nb mixed-signal and digital circuits based on Rapid Single Flux Quantum (RSFQ) technology, room-temperature amplifiers, FPGA processing and control circuitry. The demonstrated cryocooled digital-RF systems are the world's first and fastest directly digitizing receivers operating with live satellite signals in X-band and performing signal acquisition in HF to L-band at ˜30GHz clock frequencies.

Comparative evaluation of bovine derived hydroxyapatite and synthetic hydroxyapatite graft in bone regeneration of human maxillary cystic defects: a clinico-radiological study.

PubMed

Kattimani, Vivekanand S; Chakravarthi, Srinivas P; Neelima Devi, K Naga; Sridhar, Meka S; Prasad, L Krishna

2014-01-01

Bone grafts are frequently used in the treatment of bone defects. Bone harvesting can cause postoperative complications and sometimes does not provide a sufficient quantity of bone. Therefore, synthetic biomaterials have been investigated as an alternative to autogenous bone grafts. The aim of this study was to evaluate and compare bovine derived hydroxyapatite (BHA) and synthetic hydroxyapatite (SHA) graft material as bone graft substitute in maxillary cystic bony defects. Patients were analyzed by computerized densitometric study and digital radiography. In this study, 12 patients in each group were included randomly after clinical and radiological evaluation. The integration of hydroxyapatite was assessed with mean bone density, surgical site margin, and radiological bone formation characteristics, of the successful graft cases using computer densitometry and radio-visiograph. Statistical analysis was carried out using Mann-Whitney U-test, Wilcoxon matched pairs test and paired t-test. By the end of 24 th week, the grafted defects radiologically and statistically showed similar volumes of bone formation. However, the significant changes observed in the formation of bone and merging of material and surgical site margin at 1 st week to 1 st month. The results were significant and correlating with all the parameters showing the necessity of the grafting for early bone formation. However, the bone formation pattern is different in both BHA and SHA group at 3 rd month interval with significant P value. Both BHA and SHA graft materials are biocompatible for filling bone defects, showing less resorption and enhanced bone formation with similar efficacy. Our study showed maximum bone healing within 12 weeks of grafting of defects. The BHA is economical; however, price difference between the two is very nominal.

MDA-image: an environment of networked desktop computers for teleradiology/pathology.

PubMed

Moffitt, M E; Richli, W R; Carrasco, C H; Wallace, S; Zimmerman, S O; Ayala, A G; Benjamin, R S; Chee, S; Wood, P; Daniels, P

1991-04-01

MDA-Image, a project of The University of Texas M. D. Anderson Cancer Center, is an environment of networked desktop computers for teleradiology/pathology. Radiographic film is digitized with a film scanner and histopathologic slides are digitized using a red, green, and blue (RGB) video camera connected to a microscope. Digitized images are stored on a data server connected to the institution's computer communication network (Ethernet) and can be displayed from authorized desktop computers connected to Ethernet. Images are digitized for cases presented at the Bone Tumor Management Conference, a multidisciplinary conference in which treatment options are discussed among clinicians, surgeons, radiologists, pathologists, radiotherapists, and medical oncologists. These radiographic and histologic images are shown on a large screen computer monitor during the conference. They are available for later review for follow-up or representation.

Severe Foot Lesions in Dairy Goats Associated with Digital Dermatitis Treponemes.

PubMed

Crosby-Durrani, H E; Clegg, S R; Singer, E; Angell, J W; Evans, N J; Carter, S D; Blundell, R J; Duncan, J S

2016-05-01

Treponeme-associated foot disease has been described in cattle with digital dermatitis and sheep with contagious ovine digital dermatitis. In this study, severe foot lesions in dairy goats associated with digital dermatitis treponemes (i.e. Treponema medium, Treponema phagedenis and Treponema pedis) were characterized macroscopically, radiographically and histologically. The main macroscopic foot lesion was of extensive solar ulceration with or without exophytic papilliform hyperkeratosis. Radiographically, the distal phalanx and distal sesamoid bones were severely damaged and remodelled. Histologically, the lesion was categorized as a chronic lymphoplasmacytic, suppurative and ulcerative pododermatitis. Immunohistochemistry identified the spirochaetal microorganisms located extracellularly in the superficial horn. Study limitations mean that the treponeme bacteria could not be considered the sole or causal agents in the cases described. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Ex vivo accuracy of an apex locator using digital signal processing in primary teeth.

PubMed

Leonardo, Mário Roberto; da Silva, Lea Assed Bezerra; Nelson-Filho, Paulo; da Silva, Raquel Assed Bezerra; Lucisano, Marília Pacífico

2009-01-01

The purpose of this study was to evaluate ex vivo the accuracy an electronic apex locator during root canal length determination in primary molars. One calibrated examiner determined the root canal length in 15 primary molars (total=34 root canals) with different stages of root resorption. Root canal length was measured both visually with the placement of a K-file 1 mm short of the apical foramen or the apical resorption bevel, and electronically using an electronic apex locator (Digital Signal Processing). Data were analyzed statistically using the intraclass correlation (ICC) test. Comparing the actual and electronic root canal length measurements in the primary teeth showed a high correlation (ICC=0.95). The Digital Signal Processing apex locator is useful and accurate for apex foramen location during root canal length measurement in primary molars.

A Comparison of Patients Absorption Doses with Bone Deformity Due to the EOS Imaging and Digital Radiology

PubMed Central

Abrisham, Seyed Mohammad J.; Bouzarjomehri, Fathollah; Nafisi-Moghadam, Reza; Sobhan, Mohammad R.; Gadimi, Mahdie; Omidvar, Fereshte

2017-01-01

Background: This study has aimed to measure the patient dose in entire spine radiography by EOS system in comparison with the digital radiography. Methods: EOS stereo-radiography was used for frontal and lateral view spine imaging in 41 patients in a prospective analytical study. A calibrated dose area product (DAP) meter was used for calibration of the DAP in EOS system. The accuracy and precision of the system was confirmed according to the acceptance testing. The same procedure was used for 18 patients referred for lumbar spine digital radiology (overall 36 images). Results: Although radiation fields in the EOS were almost twice of that in digital radiology, and the average peak tube voltage (kVp), current supply to the tube (mA), and the average size and age of the patients referred for EOS imaging were greater than digital radiology, however, the average DAP in EOS was 1/5 of that in digital radiology system. Also, the average dose in the EOS was about 1/20 of that in digital radiology. Conclusion: The patient dose in EOS imaging system was lower in comparison with digital radiology (1/20). PMID:28656161

A Comparison of Patients Absorption Doses with Bone Deformity Due to the EOS Imaging and Digital Radiology.

PubMed

Abrisham, Seyed Mohammad J; Bouzarjomehri, Fathollah; Nafisi-Moghadam, Reza; Sobhan, Mohammad R; Gadimi, Mahdie; Omidvar, Fereshte

2017-05-01

This study has aimed to measure the patient dose in entire spine radiography by EOS system in comparison with the digital radiography. EOS stereo-radiography was used for frontal and lateral view spine imaging in 41 patients in a prospective analytical study. A calibrated dose area product (DAP) meter was used for calibration of the DAP in EOS system. The accuracy and precision of the system was confirmed according to the acceptance testing. The same procedure was used for 18 patients referred for lumbar spine digital radiology (overall 36 images). Although radiation fields in the EOS were almost twice of that in digital radiology, and the average peak tube voltage (kV p ), current supply to the tube (mA), and the average size and age of the patients referred for EOS imaging were greater than digital radiology, however, the average DAP in EOS was 1/5 of that in digital radiology system. Also, the average dose in the EOS was about 1/20 of that in digital radiology. The patient dose in EOS imaging system was lower in comparison with digital radiology (1/20).

Realization of Quantum Digital Signatures without the Requirement of Quantum Memory

NASA Astrophysics Data System (ADS)

Collins, Robert J.; Donaldson, Ross J.; Dunjko, Vedran; Wallden, Petros; Clarke, Patrick J.; Andersson, Erika; Jeffers, John; Buller, Gerald S.

2014-07-01

Digital signatures are widely used to provide security for electronic communications, for example, in financial transactions and electronic mail. Currently used classical digital signature schemes, however, only offer security relying on unproven computational assumptions. In contrast, quantum digital signatures offer information-theoretic security based on laws of quantum mechanics. Here, security against forging relies on the impossibility of perfectly distinguishing between nonorthogonal quantum states. A serious drawback of previous quantum digital signature schemes is that they require long-term quantum memory, making them impractical at present. We present the first realization of a scheme that does not need quantum memory and which also uses only standard linear optical components and photodetectors. In our realization, the recipients measure the distributed quantum signature states using a new type of quantum measurement, quantum state elimination. This significantly advances quantum digital signatures as a quantum technology with potential for real applications.

Realization of quantum digital signatures without the requirement of quantum memory.

PubMed

Collins, Robert J; Donaldson, Ross J; Dunjko, Vedran; Wallden, Petros; Clarke, Patrick J; Andersson, Erika; Jeffers, John; Buller, Gerald S

2014-07-25

Digital signatures are widely used to provide security for electronic communications, for example, in financial transactions and electronic mail. Currently used classical digital signature schemes, however, only offer security relying on unproven computational assumptions. In contrast, quantum digital signatures offer information-theoretic security based on laws of quantum mechanics. Here, security against forging relies on the impossibility of perfectly distinguishing between nonorthogonal quantum states. A serious drawback of previous quantum digital signature schemes is that they require long-term quantum memory, making them impractical at present. We present the first realization of a scheme that does not need quantum memory and which also uses only standard linear optical components and photodetectors. In our realization, the recipients measure the distributed quantum signature states using a new type of quantum measurement, quantum state elimination. This significantly advances quantum digital signatures as a quantum technology with potential for real applications.

An ultrastructural and immunogold localization study of proteoglycans associated with the osteocytes of fetal bone in osteogenesis imperfecta.

PubMed

Sarathchandra, P; Pope, F M; Ali, S Y

1996-06-01

Osteogenesis imperfecta (OI) is a rare, heterogeneous, inherited connective tissue disorder frequently caused by abnormalities of type I collagen. It is characterized by bone fragility, osteopenia, and progressive skeletal deformities. Electron microscopy of three OI type II fetal bone samples revealed numerous large osteocyte lacunae. In addition, there was a perilacunar osteoid-like band of collagen surrounding the osteocytes, which was unmineralized and morphologically unusual. Furthermore, large osteocyte lacunae contained fine particles and filamentous material similar to the expected ultrastructural appearance of proteoglycans. More detailed examination was carried out using histochemical and immunogold localization of proteoglycans at light and ultrastructural levels. These tests and the use of electron probe X-ray microanalysis confirmed that the material in the osteocyte lacunae was proteoglycan. In contrast, in the age- and site-matched normal fetal bone, all the osteocyte lacunae appeared negative for proteoglycan. Proteoglycans are regarded as inhibitors of calcification. Our observation of substantial amounts of proteoglycan in abnormally enlarged osteocytic lacunae of some OI fetal bone suggests association with the abnormal bone of this particular subtype of OI type II.

Reconstruction of radial bone defect in rat by calcium silicate biomaterials.

PubMed

Oryan, Ahmad; Alidadi, Soodeh

2018-05-15

Despite many attempts, an appropriate therapeutic method has not yet been found to enhance bone formation, mechanical strength and structural and functional performances of large bone defects. In the present study, the bone regenerative potential of calcium silicate (CS) biomaterials combined with chitosan (CH) as calcium silicate/chitosan (CSC) scaffold was investigated in a critical radial bone defect in a rat model. The bioimplants were bilaterally implanted in the defects of 20 adult Sprague-Dawley rats. The rats were euthanized and the bone specimens were harvested at the 56th postoperative day. The healed radial bones were evaluated by three-dimensional CT, radiology, histomorphometric analysis, biomechanics, and scanning electron microscopy. The XRD analysis of the CS biomaterial showed its similarity to wollastonite (β-SiCO 3 ). The degradation rate of the CSC scaffold was much higher and it induced milder inflammatory reaction when compared to the CH alone. More bone formation and higher biomechanical performance were observed in the CSC treated group in comparison with the CH treated ones in histological, CT scan and biomechanical examinations. Scanning electron microscopic observation demonstrated the formation of more hydroxyapatite crystals in the defects treated with CSC. This study showed that the CSC biomaterials could be used as proper biodegradable materials in the field of bone reconstruction and tissue engineering. Copyright © 2018 Elsevier Inc. All rights reserved.

The Comprehensive Evaluation of Electronic Learning Tools and Educational Software (CEELTES)

ERIC Educational Resources Information Center

Karolcík, Štefan; Cipková, Elena; Hrušecký, Roman; Veselský, Milan

2015-01-01

Despite the fact that digital technologies are more and more used in the learning and education process, there is still lack of professional evaluation tools capable of assessing the quality of used digital teaching aids in a comprehensive and objective manner. Construction of the Comprehensive Evaluation of Electronic Learning Tools and…

Local Places, Global Connections: Libraries in the Digital Age. What's Going On Series.

ERIC Educational Resources Information Center

Benton Foundation, Washington, DC.

Libraries have long been pivotal community institutions--public spaces where people can come together to learn, reflect, and interact. Today, information is rapidly spreading beyond books and journals to digital government archives, business databases, electronic sound and image collections, and the flow of electronic impulses over computer…

Electronic Current Transducer (ECT) for high voltage dc lines

NASA Astrophysics Data System (ADS)

Houston, J. M.; Peters, P. H., Jr.; Summerayes, H. R., Jr.; Carlson, G. J.; Itani, A. M.

1980-02-01

The development of a bipolar electronic current transducer (ECT) for measuring the current in a high voltage dc (HVDC) power line at line potential is discussed. The design and construction of a free standing ECT for use on a 400 kV line having a nominal line current of 2000 A is described. Line current is measured by a 0.0001 ohm shunt whose voltage output is sampled by a 14 bit digital data link. The high voltage interface between line and ground is traversed by optical fibers which carry digital light signals as far as 300 m to a control room where the digital signal is converted back to an analog representation of the shunt voltage. Two redundant electronic and optical data links are used in the prototype. Power to operate digital and optical electronics and temperature controlling heaters at the line is supplied by a resistively and capacitively graded 10 stage cascade of ferrite core transformers located inside the hollow, SF6 filled, porcelain support insulator. The cascade is driven by a silicon controlled rectifier inverter which supplies about 100 W of power at 30 kHz.

Deep Cryogenic Low Power 24 Bits Analog to Digital Converter with Active Reverse Cryostat

NASA Astrophysics Data System (ADS)

Turqueti, Marcos; Prestemon, Soren; Albright, Robert

LBNL is developing an innovative data acquisition module for superconductive magnets where the front-end electronics and digitizer resides inside the cryostat. This electronic package allows conventional electronic technologies such as enhanced metal-oxide-semiconductor to work inside cryostats at temperatures as low as 4.2 K. This is achieved by careful management of heat inside the module that keeps the electronic envelop at approximately 85 K. This approach avoids all the difficulties that arise from changes in carrier mobility that occur in semiconductors at deep cryogenic temperatures. There are several advantages in utilizing this system. A significant reduction in electrical noise from signals captured inside the cryostat occurs due to the low temperature that the electronics is immersed in, reducing the thermal noise. The shorter distance that signals are transmitted before digitalization reduces pickup and cross-talk between channels. This improved performance in signal-to-noise rate by itself is a significant advantage. Another important advantage is the simplification of the feedthrough interface on the cryostat head. Data coming out of the cryostat is digital and serial, dramatically reducing the number of lines going through the cryostat feedthrough interface. It is important to notice that all lines coming out of the cryostat are digital and low voltage, reducing the possibility of electric breakdown inside the cryostat. This paper will explain in details the architecture and inner workings of this data acquisition system. It will also provide the performance of the analog to digital converter when the system is immersed in liquid helium, and in liquid nitrogen. Parameters such as power dissipation, integral non-linearity, effective number of bits, signal-to-noise and distortion, will be presented for both temperatures.

Deep Cryogenic Low Power 24 Bits Analog to Digital Converter with Active Reverse Cryostat

DOE PAGES

Turqueti, Marcos; Prestemon, Soren; Albright, Robert

2015-07-15

LBNL is developing an innovative data acquisition module for superconductive magnets where the front-end electronics and digitizer resides inside the cryostat. This electronic package allows conventional electronic technologies such as enhanced metal–oxide–semiconductor to work inside cryostats at temperatures as low as 4.2 K. This is achieved by careful management of heat inside the module that keeps the electronic envelop at approximately 85 K. This approach avoids all the difficulties that arise from changes in carrier mobility that occur in semiconductors at deep cryogenic temperatures. There are several advantages in utilizing this system. A significant reduction in electrical noise from signalsmore » captured inside the cryostat occurs due to the low temperature that the electronics is immersed in, reducing the thermal noise. The shorter distance that signals are transmitted before digitalization reduces pickup and cross-talk between channels. This improved performance in signal-to-noise rate by itself is a significant advantage. Another important advantage is the simplification of the feedthrough interface on the cryostat head. Data coming out of the cryostat is digital and serial, dramatically reducing the number of lines going through the cryostat feedthrough interface. It is important to notice that all lines coming out of the cryostat are digital and low voltage, reducing the possibility of electric breakdown inside the cryostat. This paper will explain in details the architecture and inner workings of this data acquisition system. It will also provide the performance of the analog to digital converter when the system is immersed in liquid helium, and in liquid nitrogen. Parameters such as power dissipation, integral non-linearity, effective number of bits, signal-to-noise and distortion, will be presented for both temperatures.« less

Fractal analysis of mandibular trabecular bone: optimal tile sizes for the tile counting method.

PubMed

Huh, Kyung-Hoe; Baik, Jee-Seon; Yi, Won-Jin; Heo, Min-Suk; Lee, Sam-Sun; Choi, Soon-Chul; Lee, Sun-Bok; Lee, Seung-Pyo

2011-06-01

This study was performed to determine the optimal tile size for the fractal dimension of the mandibular trabecular bone using a tile counting method. Digital intraoral radiographic images were obtained at the mandibular angle, molar, premolar, and incisor regions of 29 human dry mandibles. After preprocessing, the parameters representing morphometric characteristics of the trabecular bone were calculated. The fractal dimensions of the processed images were analyzed in various tile sizes by the tile counting method. The optimal range of tile size was 0.132 mm to 0.396 mm for the fractal dimension using the tile counting method. The sizes were closely related to the morphometric parameters. The fractal dimension of mandibular trabecular bone, as calculated with the tile counting method, can be best characterized with a range of tile sizes from 0.132 to 0.396 mm.

Fractal analysis of mandibular trabecular bone: optimal tile sizes for the tile counting method

PubMed Central

Huh, Kyung-Hoe; Baik, Jee-Seon; Heo, Min-Suk; Lee, Sam-Sun; Choi, Soon-Chul; Lee, Sun-Bok; Lee, Seung-Pyo

2011-01-01

Purpose This study was performed to determine the optimal tile size for the fractal dimension of the mandibular trabecular bone using a tile counting method. Materials and Methods Digital intraoral radiographic images were obtained at the mandibular angle, molar, premolar, and incisor regions of 29 human dry mandibles. After preprocessing, the parameters representing morphometric characteristics of the trabecular bone were calculated. The fractal dimensions of the processed images were analyzed in various tile sizes by the tile counting method. Results The optimal range of tile size was 0.132 mm to 0.396 mm for the fractal dimension using the tile counting method. The sizes were closely related to the morphometric parameters. Conclusion The fractal dimension of mandibular trabecular bone, as calculated with the tile counting method, can be best characterized with a range of tile sizes from 0.132 to 0.396 mm. PMID:21977478

Cartilage Morphological and Histological Findings After Reconstruction of the Glenoid With an Iliac Crest Bone Graft.

PubMed

Auffarth, Alexander; Resch, Herbert; Matis, Nicholas; Hudelmaier, Martin; Wirth, Wolfgang; Forstner, Rosemarie; Neureiter, Daniel; Traweger, Andreas; Moroder, Philipp

2018-04-01

The J-bone graft is presumably representative of iliac crest bone grafts in general and allows anatomic glenoid reconstruction in cases of bone defects due to recurrent traumatic anterior shoulder dislocations. As a side effect, these grafts have been observed to be covered by some soft, cartilage-like tissue when arthroscopy has been indicated after such procedures. To evaluate the soft tissue covering of J-bone grafts by use of magnetic resonance imaging (MRI) and histological analysis. Case series; Level of evidence, 4. Patients underwent MRI at 1 year after the J-bone graft procedures. Radiological data were digitally processed and evaluated by segmentation of axial images. Independent from the MRI analysis, 2 biopsy specimens of J-bone grafts were harvested for descriptive histological analysis. Segmentation of the images revealed that all grafts were covered by soft tissue. This layer had an average thickness of 0.87 mm compared with 1.96 mm at the adjacent native glenoid. Of the 2 biopsy specimens, one exhibited evident hyaline-like cartilage and the other presented patches of chondrocytes embedded in a glycosaminoglycan-rich extracellular matrix. J-bone grafts are covered by soft tissue that can differentiate into fibrous and potentially hyaline cartilage. This feature may prove beneficial for delaying the onset of dislocation arthropathy of the shoulder.

Determination of in vivo mechanical properties of long bones from their impedance response curves

NASA Technical Reports Server (NTRS)

Borders, S. G.

1981-01-01

A mathematical model consisting of a uniform, linear, visco-elastic, Euler-Bernoulli beam to represent the ulna or tibia of the vibrating forearm or leg system is developed. The skin and tissue compressed between the probe and bone is represented by a spring in series with the beam. The remaining skin and tissue surrounding the bone is represented by a visco-elastic foundation with mass. An extensive parametric study is carried out to determine the effect of each parameter of the mathematical model on its impedance response. A system identification algorithm is developed and programmed on a digital computer to determine the parametric values of the model which best simulate the data obtained from an impedance test.

Periapical and endodontic status scale based on periapical bone lesions and endodontic treatment quality evaluation using cone-beam computed tomography.

PubMed

Venskutonis, Tadas; Plotino, Gianluca; Tocci, Luigi; Gambarini, Gianluca; Maminskas, Julius; Juodzbalys, Gintaras

2015-02-01

The purpose of this study was to present a new periapical and endodontic status scale (PESS) that is based on the complex periapical index (COPI), which was designed for the identification and classification of periapical bone lesions in cases of apical periodontitis, and the endodontically treated tooth index, which was designed for endodontic treatment quality evaluation by means of cone-beam computed tomographic (CBCT) analysis. Periapical and endodontic status parameters were selected from the already known indexes and scientific literature for radiologic evaluation. Radiographic images (CBCT imaging, digital orthopantomography [DOR], and digital periapical radiography) from 55 patients were analyzed. All parameters were evaluated on CBCT, DOR, and digital periapical radiographic images by 2 external observers. The statistical analysis was performed with software SPSS version 19.0 (SPSS Inc, Chicago, IL). Chi-square tests were used to compare frequencies of qualitative variables. The level of significance was set at P ≤ .05. Overall intraobserver and interobserver agreements were very good and good, respectively. CBCT analysis found more lesions and lesions of bigger dimension (P < .001). CBCT imaging was also superior in locating lesions in the apical part on the side compared with DOR and in the diagnosis of cortical bone destruction compared with both methods (P < .001). Through CBCT analysis, more root canals and more canals associated with lesions were found. The most informative and reproducible periapical and endodontic status parameters were selected, and a new PESS was proposed. The classification proposed in the present study seems to be reproducible and objective and adds helpful information with respect to the existing indexes. Future studies need to be conducted to validate PESS. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Towards the resolution of a long-standing evolutionary question: muscle identity and attachments are mainly related to topological position and not to primordium or homeotic identity of digits.

PubMed

Diogo, Rui; Walsh, Sean; Smith, Christopher; Ziermann, Janine M; Abdala, Virginia

2015-06-01

Signaling for limb bone development usually precedes that for muscle development, such that cartilage is generally present before muscle formation. It remains obscure, however, if: (i) tetrapods share a general, predictable spatial correlation between bones and muscles; and, if that is the case, if (ii) such a correlation would reflect an obligatory association between the signaling involved in skeletal and muscle morphogenesis. We address these issues here by using the results of a multidisciplinary analysis of the appendicular muscles of all major tetrapod groups integrating dissections, muscle antibody stainings, regenerative and ontogenetic analyses of fluorescently-labeled (GFP) animals, and studies of non-pentadactyl human limbs related to birth defects. Our synthesis suggests that there is a consistent, surprising anatomical pattern in both normal and abnormal phenotypes, in which the identity and attachments of distal limb muscles are mainly related to the topological position, and not to the developmental primordium (anlage) or even the homeotic identity, of the digits to which they are attached. This synthesis is therefore a starting point towards the resolution of a centuries-old question raised by authors such as Owen about the specific associations between limb bones and muscles. This question has crucial implications for evolutionary and developmental biology, and for human medicine because non-pentadactyly is the most common birth defect in human limbs. In particular, this synthesis paves the way for future developmental experimental and mechanistic studies, which are needed to clarify the processes that may be involved in the elaboration of the anatomical patterns described here, and to specifically test the hypothesis that distal limb muscle identity/attachment is mainly related to digit topology. © 2015 Anatomical Society.

Osteointegration of porous absorbable bone substitutes: A systematic review of the literature

PubMed Central

Paulo, Maria Júlia Escanhoela; dos Santos, Mariana Avelino; Cimatti, Bruno; Gava, Nelson Fabrício; Riberto, Marcelo; Engel, Edgard Eduard

2017-01-01

Biomaterials’ structural characteristics and the addition of osteoinductors influence the osteointegration capacity of bone substitutes. This study aims to identify the characteristics of porous and resorbable bone substitutes that influence new bone formation. An Internet search for studies reporting new bone formation rates in bone defects filled with porous and resorbable substitutes was performed in duplicate using the PubMed, Web of Science, Scielo, and University of São Paulo Digital Library databases. Metaphyseal or calvarial bone defects 4 to 10 mm in diameter from various animal models were selected. New bone formation rates were collected from the histomorphometry or micro-CT data. The following variables were analyzed: animal model, bone region, defect diameter, follow-up time after implantation, basic substitute material, osteoinductor addition, pore size and porosity. Of 3,266 initially identified articles, 15 articles describing 32 experimental groups met the inclusion criteria. There were no differences between the groups in the experimental model characteristics, except for the follow-up time, which showed a very weak to moderate correlation with the rate of new bone formation. In terms of the biomaterial and structural characteristics, only porosity showed a significant influence on the rate of new bone formation. Higher porosity is related to higher new bone formation rates. The influence of other characteristics could not be identified, possibly due to the large variety of experimental models and methodologies used to estimate new bone formation rates. We suggest the inclusion of standard control groups in future experimental studies to compare biomaterials. PMID:28793006

Young's modulus and SEM analysis of leg bones exposed to simulated microgravity by hind limb suspension (HLS)

NASA Astrophysics Data System (ADS)

Patel, Niravkumar D.; Mehta, Rahul; Ali, Nawab; Soulsby, Michael; Chowdhury, Parimal

2013-04-01

The aim of this study was to determine composition of the leg bone tissue of rats that were exposed to simulated microgravity by Hind-Limb Suspension (HLS) by tail for one week. The leg bones were cross sectioned, cleaned of soft tissues, dried and sputter coated, and then placed horizontally on the stage of a Scanning Electron Microscope (SEM) for analysis. Interaction of a 17.5 keV electron beam, incident from the vertical direction on the sample, generated images using two detectors. X-rays emitted from the sample during electron bombardment were measured with an Energy Dispersive Spectroscopy (EDS) feature of SEM using a liquid-nitrogen cooled Si(Li) detector with a resolution of 144 eV at 5.9 keV (25Mn Kα x-ray). Kα- x-rays from carbon, oxygen, phosphorus and calcium formed the major peaks in the spectrum. Relative percentages of these elements were determined using a software that could also correct for ZAF factors namely Z(atomic number), A(X-ray absorption) and F(characteristic fluorescence). The x-rays from the control groups and from the experimental (HLS) groups were analyzed on well-defined parts (femur, tibia and knee) of the leg bone. The SEM analysis shows that there are definite changes in the hydroxyl or phosphate group of the main component of the bone structure, hydroxyapatite [Ca10(PO4)6(OH)2], due to hind limb suspension. In a separate experiment, entire leg bones (both from HLS and control rats) were subjected to mechanical stress by mean of a variable force. The stress vs. strain graph was fitted with linear and polynomial function, and the parameters reflecting the mechanical strength of the bone, under increasing stress, were calculated. From the slope of the linear part of the graph the Young's modulus for HLS bones were calculated and found to be 2.49 times smaller than those for control bones.

Digital Natives Revisited: Developing Digital Wisdom in the Modern University

ERIC Educational Resources Information Center

Harris, David

2012-01-01

The seminal work of Prensky on "digital natives" and "digital wisdom" is used to launch a broader discussion on the relations between electronic communication, higher education, and popular and elite culture. Prensky's critics commonly contrast his polarisations and generational divisions with a more complex picture of types of engagement with…

Digital Tools: Enhancing Painting Skills among Malaysian Secondary School Students

ERIC Educational Resources Information Center

Samah, Azimah A.; Putih, Abu Talib; Hussin, Zaharah

2016-01-01

Digital tools refer to software applications in the production of artworks particularly in painting. Digital art work is materialized by using computers, software and a combination of computer peripherals such as tablet support. With the aid of electronic equipment, digital artists manipulate pixels or coloring with light to compose the work and…

A Digital View of History: Drawing and Discussing Models of Historical Concepts

ERIC Educational Resources Information Center

Manfra, Meghan McGlinn; Coven, Robert M.

2011-01-01

Digital history refers to "the study of the past using a variety of electronically reproduced primary source texts, images, and artifacts as well as the constructed narratives, accounts, or presentations that result from digital historical inquiry." Access to digitized primary sources can promote active instruction in historical thinking. A…

Secure communications system

NASA Technical Reports Server (NTRS)

Doland, G. D.

1977-01-01

System employs electronically randomized variant of quadraphase modulation and demodulation between two synchronized transceivers. System uses off-the-shelf components. It may be used with digital data, command signals, delta-modulated voice signals, digital television signals, or other data converted to digital form.

A front-end readout Detector Board for the OpenPET electronics system

NASA Astrophysics Data System (ADS)

Choong, W.-S.; Abu-Nimeh, F.; Moses, W. W.; Peng, Q.; Vu, C. Q.; Wu, J.-Y.

2015-08-01

We present a 16-channel front-end readout board for the OpenPET electronics system. A major task in developing a nuclear medical imaging system, such as a positron emission computed tomograph (PET) or a single-photon emission computed tomograph (SPECT), is the electronics system. While there are a wide variety of detector and camera design concepts, the relatively simple nature of the acquired data allows for a common set of electronics requirements that can be met by a flexible, scalable, and high-performance OpenPET electronics system. The analog signals from the different types of detectors used in medical imaging share similar characteristics, which allows for a common analog signal processing. The OpenPET electronics processes the analog signals with Detector Boards. Here we report on the development of a 16-channel Detector Board. Each signal is digitized by a continuously sampled analog-to-digital converter (ADC), which is processed by a field programmable gate array (FPGA) to extract pulse height information. A leading edge discriminator creates a timing edge that is ``time stamped'' by a time-to-digital converter (TDC) implemented inside the FPGA . This digital information from each channel is sent to an FPGA that services 16 analog channels, and then information from multiple channels is processed by this FPGA to perform logic for crystal lookup, DOI calculation, calibration, etc.

A front-end readout Detector Board for the OpenPET electronics system

DOE PAGES

Choong, W. -S.; Abu-Nimeh, F.; Moses, W. W.; ...

2015-08-12

Here, we present a 16-channel front-end readout board for the OpenPET electronics system. A major task in developing a nuclear medical imaging system, such as a positron emission computed tomograph (PET) or a single-photon emission computed tomograph (SPECT), is the electronics system. While there are a wide variety of detector and camera design concepts, the relatively simple nature of the acquired data allows for a common set of electronics requirements that can be met by a flexible, scalable, and high-performance OpenPET electronics system. The analog signals from the different types of detectors used in medical imaging share similar characteristics, whichmore » allows for a common analog signal processing. The OpenPET electronics processes the analog signals with Detector Boards. Here we report on the development of a 16-channel Detector Board. Each signal is digitized by a continuously sampled analog-to-digital converter (ADC), which is processed by a field programmable gate array (FPGA) to extract pulse height information. A leading edge discriminator creates a timing edge that is "time stamped" by a time-to-digital converter (TDC) implemented inside the FPGA. In conclusion, this digital information from each channel is sent to an FPGA that services 16 analog channels, and then information from multiple channels is processed by this FPGA to perform logic for crystal lookup, DOI calculation, calibration, etc.« less

Electron spin resonance (ESR) dose measurement in bone of Hiroshima A-bomb victim.

PubMed

Kinoshita, Angela; Baffa, Oswaldo; Mascarenhas, Sérgio

2018-01-01

Explosion of the bombs in Hiroshima and Nagasaki corresponds to the only historical moment when atomic bombs were used against civilians. This event triggered countless investigations into the effects and dosimetry of ionizing radiation. However, none of the investigations has used the victims' bones as dosimeter. Here, we assess samples of bones obtained from fatal victims of the explosion by Electron Spin Resonance (ESR). In 1973, one of the authors of the present study (SM) traveled to Japan and conducted a preliminary experiment on the victims' bone samples. The idea was to use the paramagnetism induced in bone after irradiation to measure the radiation dose. Technological advances involved in the construction of spectrometers, better knowledge of the paramagnetic center, and improvement in signal processing techniques have allowed us to resume the investigation. We obtained a reconstructed dose of 9.46 ± 3.4 Gy from the jawbone, which was compatible with the dose distribution in different locations as measured in non-biological materials such as wall bricks and roof tiles.

Scanning electron microscopy (SEM) and X-ray dispersive spectrometry evaluation of direct laser metal sintering surface and human bone interface: a case series.

PubMed

Mangano, Carlo; Piattelli, Adriano; Raspanti, Mario; Mangano, Francesco; Cassoni, Alessandra; Iezzi, Giovanna; Shibli, Jamil Awad

2011-01-01

Recent studies have shown that direct laser metal sintering (DLMS) produces structures with complex geometry and consequently that allow better osteoconductive properties. The aim of this patient report was to evaluate the early bone response to DLMS implant surface retrieved from human jaws. Four experimental DLMS implants were inserted in the posterior mandible of four patients during conventional dental implant surgery. After 8 weeks, the micro-implants and the surrounding tissue were removed and prepared for scanning electron microscopy (SEM) and histomorphometric analysis to evaluate the bone-implant interface. The SEM and EDX evaluations showed a newly formed tissue composed of calcium and phosphorus. The bone-to-implant contact presented a mean of 60.5 ± 11.6%. Within the limits of this patient report, data suggest that the DLMS surfaces presented a close contact with the human bone after a healing period of 8 weeks.

In vitro characterizations of mesoporous hydroxyapatite as a controlled release delivery device for VEGF in orthopedic applications.

PubMed

Poh, Chye Khoon; Ng, Suxiu; Lim, Tee Yong; Tan, Hark Chuan; Loo, Joachim; Wang, Wilson

2012-11-01

Following bone implant surgery, prolonged ischemic conditions at the implant site often result in postsurgical complications like failure of osseointegration at the bone-implant interface which can lead to implant failure. Thus, restoration of the vascular supply is paramount to the proper development of the bone. High surface area mesostructured materials have been shown to be attractive candidates for bone regeneration to enhance cell adhesion and cell proliferation. This study uses hydroxyapatite, a naturally occurring mineral in the bone, fabricated to a range of suitable pore sizes, infused with vascular endothelial growth factor (VEGF), to be progressively released to stimulate revascularization. In this study, several characterizations including nitrogen adsorption analysis, Fourier-transformed infrared spectroscopy, X-ray diffraction, field emission scanning electron microscope, and transmission electron microscope were used to evaluate the synthesized mesoporous hydroxyapatite (MHA). The results showed that MHA can gradually release VEGF for enhancing revascularization, which is beneficial for orthopedic applications. Copyright © 2012 Wiley Periodicals, Inc.

The Digital Astronaut Project Computational Bone Remodeling Model (Beta Version) Bone Summit Summary Report

NASA Technical Reports Server (NTRS)

Pennline, James; Mulugeta, Lealem

2013-01-01

Under the conditions of microgravity, astronauts lose bone mass at a rate of 1% to 2% a month, particularly in the lower extremities such as the proximal femur [1-3]. The most commonly used countermeasure against bone loss in microgravity has been prescribed exercise [4]. However, data has shown that existing exercise countermeasures are not as effective as desired for preventing bone loss in long duration, 4 to 6 months, spaceflight [1,3,5,6]. This spaceflight related bone loss may cause early onset of osteoporosis to place the astronauts at greater risk of fracture later in their lives. Consequently, NASA seeks to have improved understanding of the mechanisms of bone demineralization in microgravity in order to appropriately quantify this risk, and to establish appropriate countermeasures [7]. In this light, NASA's Digital Astronaut Project (DAP) is working with the NASA Bone Discipline Lead to implement well-validated computational models to help predict and assess bone loss during spaceflight, and enhance exercise countermeasure development. More specifically, computational modeling is proposed as a way to augment bone research and exercise countermeasure development to target weight-bearing skeletal sites that are most susceptible to bone loss in microgravity, and thus at higher risk for fracture. Given that hip fractures can be debilitating, the initial model development focused on the femoral neck. Future efforts will focus on including other key load bearing bone sites such as the greater trochanter, lower lumbar, proximal femur and calcaneus. The DAP has currently established an initial model (Beta Version) of bone loss due to skeletal unloading in femoral neck region. The model calculates changes in mineralized volume fraction of bone in this segment and relates it to changes in bone mineral density (vBMD) measured by Quantitative Computed Tomography (QCT). The model is governed by equations describing changes in bone volume fraction (BVF), and rates of changes in bone cell populations that remove and replace bone in packets within the bone region. The DAP bone model is unique in several respects. In particular in takes former models of volume fraction changes one step higher in fidelity and separates BVF into separate equations for mineralized and osteoid volume fractions governed by a mineralization rate. This more closely follows the physiology of the remodeling unit cycles where bone is first resorbed and then followed by the action of osteoblasts to lay down collagen matrix which eventually becomes mineralized. In another respect, the modules allow the functional description of the time rate of change of other parameters and variables in the model during a computational simulation. More detailed description of the model, preliminary validation results, current limitation and caveats, and planned advancements are provided in sections 2 through 5. The DAP bone model is being developed primarily as a research tool, and not as a clinical tool like QCT. Even if it transitions to a clinical tool, it is not intended to replace QCT or any other clinical tool. Moreover, the DAP bone model does not predict bone fracture. Its purpose is to provide valuable additional data via "forward prediction" simulations for during and after spaceflight missions to gain insight on, (1) mechanisms of bone demineralization in microgravity, and (2) the volumetric changes at the various bone sites in response to in-flight and post-flight exercise countermeasures. This data can then be used as input to the Keyak [8] (or equivalent) FE analysis method to gain insight on how bone strength may change during and after flight. This information can also be useful to help optimize exercise countermeasure protocols to minimize changes in bone strength during flight, and improve regain of bone strength post-flight. To achieve this goal, the bone model will be integrated with DAP's exercise countermeasure models to simulate the effect of exercise prescriptions on preserving bone. More specifically, the model will accept loading history due to muscle and joint force on bone and produce quantified remodeling within the bone region under influence of the applied stress. Furthermore, because they tend to respond differently, the bone remodeling model includes both trabecular bone and cortical bone.

Using virtual ridge augmentation and 3D printing to fabricate a titanium mesh positioning device: A novel technique letter.

PubMed

Al-Ardah, Aladdin; Alqahtani, Nasser; AlHelal, Abdulaziz; Goodacre, Brian; Swamidass, Rajesh; Garbacea, Antoanela; Lozada, Jaime

2018-05-02

This technique describes a novel approach for planning and augmenting a large bony defect using a titanium mesh (TiMe). A 3-dimensional (3D) surgical model was virtually created from a cone beam computed tomography (CBCT) and wax-pattern of the final prosthetic outcome. The required bone volume (horizontally and vertically) was digitally augmented and then 3D printed to create a bone model. The 3D model was then used to contour the TiMe in accordance with the digital augmentation. With the contoured / preformed TiMe on the 3D printed model a positioning jig was made to aid the placement of the TiMe as planned during surgery. Although this technique does not impact the final outcome of the augmentation procedure, it allows the clinician to virtually design the augmentation, preform and contour the TiMe, and create a positioning jig reducing surgical time and error.

Continuous Digital Light Processing (cDLP): Highly Accurate Additive Manufacturing of Tissue Engineered Bone Scaffolds.

PubMed

Dean, David; Jonathan, Wallace; Siblani, Ali; Wang, Martha O; Kim, Kyobum; Mikos, Antonios G; Fisher, John P

2012-03-01

Highly accurate rendering of the external and internal geometry of bone tissue engineering scaffolds effects fit at the defect site, loading of internal pore spaces with cells, bioreactor-delivered nutrient and growth factor circulation, and scaffold resorption. It may be necessary to render resorbable polymer scaffolds with 50 μm or less accuracy to achieve these goals. This level of accuracy is available using Continuous Digital Light processing (cDLP) which utilizes a DLP(®) (Texas Instruments, Dallas, TX) chip. One such additive manufacturing device is the envisionTEC (Ferndale, MI) Perfactory(®). To use cDLP we integrate a photo-crosslinkable polymer, a photo-initiator, and a biocompatible dye. The dye attenuates light, thereby limiting the depth of polymerization. In this study we fabricated scaffolds using the well-studied resorbable polymer, poly(propylene fumarate) (PPF), titanium dioxide (TiO(2)) as a dye, Irgacure(®) 819 (BASF [Ciba], Florham Park, NJ) as an initiator, and diethyl fumarate as a solvent to control viscosity.

Radiological and histopathological evaluation of experimentally-induced periapical lesion in rats

PubMed Central

TEIXEIRA, Renata Cordeiro; RUBIRA, Cassia Maria Fischer; ASSIS, Gerson Francisco; LAURIS, José Roberto Pereira; CESTARI, Tania Mary; RUBIRA-BULLEN, Izabel Regina Fischer

2011-01-01

Objective This study evaluated experimentally-induced periapical bone loss sites using digital radiographic and histopathologic parameters. Material and Methods Twenty-seven Wistar rats were submitted to coronal opening of their mandibular right first molars. They were radiographed at 2, 15 and 30 days after the operative procedure by two digital radiographic storage phosphor plates (Digora®). The images were analyzed by creating a region of interest at the periapical region of each tooth (ImageJ) and registering the corresponding pixel values. After the sacrifice, the specimens were submitted to microscopic analysis in order to confirm the pulpal and periapical status of the tooth. Results There was significant statistically difference between the control and test sides in all the experimental periods regarding the pixel values (two-way ANOVA; p<0.05). Conclusions The microscopic analysis proved that a periapical disease development occurred during the experimental periods with an evolution from pulpal necrosis to periapical bone resorption. PMID:21922123

Digital Libraries and the Problem of Purpose [and] On DigiPaper and the Dissemination of Electronic Documents [and] DFAS: The Distributed Finding Aid Search System [and] Best Practices for Digital Archiving: An Information Life Cycle Approach [and] Mapping and Converting Essential Federal Geographic Data Committee (FGDC) Metadata into MARC21 and Dublin Core: Towards an Alternative to the FGDC Clearinghouse [and] Evaluating Website Modifications at the National Library of Medicine through Search Log analysis.

ERIC Educational Resources Information Center

Levy, David M.; Huttenlocher, Dan; Moll, Angela; Smith, MacKenzie; Hodge, Gail M.; Chandler, Adam; Foley, Dan; Hafez, Alaaeldin M.; Redalen, Aaron; Miller, Naomi

2000-01-01

Includes six articles focusing on the purpose of digital public libraries; encoding electronic documents through compression techniques; a distributed finding aid server; digital archiving practices in the framework of information life cycle management; converting metadata into MARC format and Dublin Core formats; and evaluating Web sites through…

s48-e-007

NASA Image and Video Library

2013-01-15

S48-E-007 (12 Sept 1991) --- Astronaut James F. Buchli, mission specialist, catches snack crackers as they float in the weightless environment of the earth-orbiting Discovery. This image was transmitted by the Electronic Still Camera, Development Test Objective (DTO) 648. The ESC is making its initial appearance on a Space Shuttle flight. Electronic still photography is a new technology that enables a camera to electronically capture and digitize an image with resolution approaching film quality. The digital image is stored on removable hard disks or small optical disks, and can be converted to a format suitable for downlink transmission or enhanced using image processing software. The Electronic Still Camera (ESC) was developed by the Man- Systems Division at the Johnson Space Center and is the first model in a planned evolutionary development leading to a family of high-resolution digital imaging devices. H. Don Yeates, JSC's Man-Systems Division, is program manager for the ESC. THIS IS A SECOND GENERATION PRINT MADE FROM AN ELECTRONICALLY PRODUCED NEGATIVE

A nanocryotron comparator can connect single-flux-quantum circuits to conventional electronics

NASA Astrophysics Data System (ADS)

Zhao, Qing-Yuan; McCaughan, Adam N.; Dane, Andrew E.; Berggren, Karl K.; Ortlepp, Thomas

2017-04-01

Integration with conventional electronics offers a straightforward and economical approach to upgrading existing superconducting technologies, such as scaling up superconducting detectors into large arrays and combining single flux quantum (SFQ) digital circuits with semiconductor logic gates and memories. However, direct output signals from superconducting devices (e.g., Josephson junctions) are usually not compatible with the input requirements of conventional devices (e.g., transistors). Here, we demonstrate the use of a single three-terminal superconducting-nanowire device, called the nanocryotron (nTron), as a digital comparator to combine SFQ circuits with mature semiconductor circuits such as complementary metal oxide semiconductor (CMOS) circuits. Since SFQ circuits can digitize output signals from general superconducting devices and CMOS circuits can interface existing CMOS-compatible electronics, our results demonstrate the feasibility of a general architecture that uses an nTron as an interface to realize a ‘super-hybrid’ system consisting of superconducting detectors, superconducting quantum electronics, CMOS logic gates and memories, and other conventional electronics.

Multifocal Tubercular Dactylitis: A Rare Presentation of Skeletal Tuberculosis in an Adult.

PubMed

Thatoi, Pravat; Parida, Manoj; Barik, Rakesh; Das, Bidyut

2017-06-01

Tubercular dactylitis is an uncommon form of osteo-articular tuberculosis seen in children. Multifocal involvement, simultaneously involving hands and feet is extremely uncommon. Here we report an adult patient with tubercular dactylitis involving multiple digits of both hands and second digit of right foot in absence of any risk factors like immunodeficiency or any debilitating condition. The patient was successfully treated with anti-tubercular drugs for six months. Mycobacterium tuberculosis infection of bones and joints can present in an unusual way but early diagnosis and treatment caries a good prognosis.

Automated system for acquisition and image processing for the control and monitoring boned nopal

NASA Astrophysics Data System (ADS)

Luevano, E.; de Posada, E.; Arronte, M.; Ponce, L.; Flores, T.

2013-11-01

This paper describes the design and fabrication of a system for acquisition and image processing to control the removal of thorns nopal vegetable (Opuntia ficus indica) in an automated machine that uses pulses of a laser of Nd: YAG. The areolas, areas where thorns grow on the bark of the Nopal, are located applying segmentation algorithms to the images obtained by a CCD. Once the position of the areolas is known, coordinates are sent to a motors system that controls the laser to interact with all areolas and remove the thorns of the nopal. The electronic system comprises a video decoder, memory for image and software storage, and digital signal processor for system control. The firmware programmed tasks on acquisition, preprocessing, segmentation, recognition and interpretation of the areolas. This system achievement identifying areolas and generating table of coordinates of them, which will be send the motor galvo system that controls the laser for removal

Digital processing of radiographic images from PACS to publishing.

PubMed

Christian, M E; Davidson, H C; Wiggins, R H; Berges, G; Cannon, G; Jackson, G; Chapman, B; Harnsberger, H R

2001-03-01

Several studies have addressed the implications of filmless radiologic imaging on telemedicine, diagnostic ability, and electronic teaching files. However, many publishers still require authors to submit hard-copy images for publication of articles and textbooks. This study compares the quality digital images directly exported from picture archive and communications systems (PACS) to images digitized from radiographic film. The authors evaluated the quality of publication-grade glossy photographs produced from digital radiographic images using 3 different methods: (1) film images digitized using a desktop scanner and then printed, (2) digital images obtained directly from PACS then printed, and (3) digital images obtained from PACS and processed to improve sharpness prior to printing. Twenty images were printed using each of the 3 different methods and rated for quality by 7 radiologists. The results were analyzed for statistically significant differences among the image sets. Subjective evaluations of the filmless images found them to be of equal or better quality than the digitized images. Direct electronic transfer of PACS images reduces the number of steps involved in creating publication-quality images as well as providing the means to produce high-quality radiographic images in a digital environment.

Digital Signature Management.

ERIC Educational Resources Information Center

Hassler, Vesna; Biely, Helmut

1999-01-01

Describes the Digital Signature Project that was developed in Austria to establish an infrastructure for applying smart card-based digital signatures in banking and electronic-commerce applications. Discusses the need to conform to international standards, an international certification infrastructure, and security features for a public directory…

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

Choong, W. -S.; Abu-Nimeh, F.; Moses, W. W.

Here, we present a 16-channel front-end readout board for the OpenPET electronics system. A major task in developing a nuclear medical imaging system, such as a positron emission computed tomograph (PET) or a single-photon emission computed tomograph (SPECT), is the electronics system. While there are a wide variety of detector and camera design concepts, the relatively simple nature of the acquired data allows for a common set of electronics requirements that can be met by a flexible, scalable, and high-performance OpenPET electronics system. The analog signals from the different types of detectors used in medical imaging share similar characteristics, whichmore » allows for a common analog signal processing. The OpenPET electronics processes the analog signals with Detector Boards. Here we report on the development of a 16-channel Detector Board. Each signal is digitized by a continuously sampled analog-to-digital converter (ADC), which is processed by a field programmable gate array (FPGA) to extract pulse height information. A leading edge discriminator creates a timing edge that is "time stamped" by a time-to-digital converter (TDC) implemented inside the FPGA. In conclusion, this digital information from each channel is sent to an FPGA that services 16 analog channels, and then information from multiple channels is processed by this FPGA to perform logic for crystal lookup, DOI calculation, calibration, etc.« less

The Heinz Electronic Library Interactive Online System (HELIOS): Building a Digital Archive Using Imaging, OCR, and Natural Language Processing Technologies.

ERIC Educational Resources Information Center

Galloway, Edward A.; Michalek, Gabrielle V.

1995-01-01

Discusses the conversion project of the congressional papers of Senator John Heinz into digital format and the provision of electronic access to these papers by Carnegie Mellon University. Topics include collection background, project team structure, document processing, scanning, use of optical character recognition software, verification…

Aircraft Electronics Maintenance Training Simulator. Curriculum Outlines.

ERIC Educational Resources Information Center

Blackhawk Technical Coll., Janesville, WI.

Instructional materials are provided for nine courses in an aircraft electronics maintenance training program. Courses are as follows: aviation basic electricity, direct current and alternating current electronics, basic avionic installations, analog electronics, digital electronics, microcomputer electronics, radio communications, aircraft…

Cost effectiveness of a medical digital library.

PubMed

Roussel, F; Darmoni, S J; Thirion, B

2001-01-01

The rapid increase in the price of electronic journals has made the optimization of collection management an urgent task. As there is currently no standard procedure for the evaluation of this problem, we applied the Reading Factor (RF), an electronically computed indicator used for consultation of individual articles. The aim of our study was to assess the cost effective impact of modifications in our digital library (i.e. change of access from the Intranet to the Internet or change in editorial policy). The digital OVID library at Rouen University Hospital continues to be cost-effective in comparison with the interlibrary loan costs. Moreover, when electronic versions are offered alongside a limited amount of interlibrary loans, a reduction in library costs was observed.

Dedifferentiated Schwann Cell Precursors Secreting Paracrine Factors Are Required for Regeneration of the Mammalian Digit Tip.

PubMed

Johnston, Adam P W; Yuzwa, Scott A; Carr, Matthew J; Mahmud, Neemat; Storer, Mekayla A; Krause, Matthew P; Jones, Karen; Paul, Smitha; Kaplan, David R; Miller, Freda D

2016-10-06

Adult mammals have lost multi-tissue regenerative capacity, except for the distal digit, which is able to regenerate via mechanisms that remain largely unknown. Here, we show that, after adult mouse distal digit removal, nerve-associated Schwann cell precursors (SCPs) dedifferentiate and secrete growth factors that promote expansion of the blastema and digit regeneration. When SCPs were dysregulated or ablated, mesenchymal precursor proliferation in the blastema was decreased and nail and bone regeneration were impaired. Transplantation of exogenous SCPs rescued these regeneration defects. We found that SCPs secrete factors that promote self-renewal of mesenchymal precursors, and we used transcriptomic and proteomic analysis to define candidate factors. Two of these, oncostatin M (OSM) and platelet-derived growth factor AA (PDGF-AA), are made by SCPs in the regenerating digit and rescued the deficits in regeneration caused by loss of SCPs. As all peripheral tissues contain nerves, these results could have broad implications for mammalian tissue repair and regeneration. Copyright © 2016 Elsevier Inc. All rights reserved.

Quantification of Wilms' tumor 1 mRNA by digital polymerase chain reaction.

PubMed

Koizumi, Yuki; Furuya, Daisuke; Endo, Teruo; Asanuma, Kouichi; Yanagihara, Nozomi; Takahashi, Satoshi

2018-02-01

Wilms' tumor 1 (WT1) is overexpressed in various hematopoietic tumors and widely used as a marker of minimal residual disease. WT1 mRNA has been analyzed using quantitative real-time polymerase chain reaction (real-time PCR). In the present study, we analyzed 40 peripheral blood and bone marrow samples obtained from cases of acute myeloid leukemia, acute lymphoblastic leukemia, and myelodysplastic syndrome at Sapporo Medical University Hospital from April 2012 to January 2015. We performed quantification of WT1 was performed using QuantStudio 3D Digital PCR System (Thermo Fisher Scientific‎) and compared the results between digital PCR and real-time PCR technology. The correlation between digital PCR and real-time PCR was very strong (R = 0.99), and the detection limits of the two methods were equivalent. Digital PCR was able to accurately detect lower WT levels compared with real-time PCR. Digital PCR technology can thus be utilized to predict WT1/ABL1 expression level accurately and should thus be useful for diagnosis or the evaluation of drug efficiency in patients with leukemia.

Preaxial Polydactyly in Sost/Sostdc1 Double Knockouts

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

Yee, C M; Collette, N M; Loots, G G

2011-07-29

In the United States, {approx}5% are born with congenital birth defects due to abnormal function of cellular processes and interactions. Sclerosteosis, a rare autosomal recessive disease, causes hyperostosis of the axial and appendicular skeleton, and patients present radial deviation, digit syndactyly, nail dysplasia, and overall high bone mineral density. Sclerosteosis is due to a loss of function of sclerostin (Sost). Sost is a Wnt (abbrev.) antagonist; when mutated, nonfunctional Sost results in hyperactive osteoblast activity which leads to abnormal high bone mass. Previous studies have shown that Sost overexpression in transgenic mice causes reduced bone mineral density and a varietymore » of limb phenotypes ranging from lost, fused, and split phalanges. Consistent with clinical manifestations of Sclerosteosis, Sost knockout mice exhibit increased generalized bone mineral density and syndactyly of the digits. Sostdc1 is a paralog of Sost that has also been described as an antagonist of Wnt signaling, in developing tooth buds. Unlike Sost knockouts, Sostdc1 null mice do not display any limb abnormalities. To determine if Sost and Sostdc1 have redundant functions during limb patterning, we examined Sost; Sostdc1 mice determined that they exhibit a novel preaxial polydactyly phenotype with a low penetrance. LacZ staining, skeletal preparations, and in situ hybridization experiments were used to help characterize this novel phenotype and understand how this phenotype develops. We find Sost and Sostdc1 to have complementary expression patterns during limb development, and the loss of their expression alters the transcription of several key limb regulators, such as Fgf8, Shh and Grem.« less

Measurement of strain distribution in cortical bone around miniscrew implants used for orthodontic anchorage using digital speckle pattern interferometry

NASA Astrophysics Data System (ADS)

Kumar, Manoj; Agarwal, Rupali; Bhutani, Ravi; Shakher, Chandra

2016-05-01

An application of digital speckle pattern interferometry (DSPI) for the measurement of deformations and strain-field distributions developed in cortical bone around orthodontic miniscrew implants inserted into the human maxilla is presented. The purpose of this study is to measure and compare the strain distribution in cortical bone/miniscrew interface of human maxilla around miniscrew implants of different diameters, different implant lengths, and implants of different commercially available companies. The technique is also used to measure tilt/rotation of canine caused due to the application of retraction springs. The proposed technique has high sensitivity and enables the observation of deformation/strain distribution. In DSPI, two specklegrams are recorded corresponding to pre- and postloading of the retraction spring. The DSPI fringe pattern is observed by subtracting these two specklegrams. Optical phase was extracted using Riesz transform and the monogenic signal from a single DSPI fringe pattern. The obtained phase is used to calculate the parameters of interest such as displacement/deformation and strain/stress. The experiment was conducted on a dry human skull fulfilling the criteria of intact dental arches and all teeth present. Eight different miniscrew implants were loaded with an insertion angulation of 45 deg in the inter-radicular region of the maxillary second premolar and molar region. The loading of miniscrew implants was done with force level (150 gf) by nickel-titanium closed-coil springs (9 mm). The obtained results from DSPI reveal that implant diameter and implant length affect the displacement and strain distribution in cortical bone layer surrounding the miniscrew implant.

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

Safigholi, Habib; Meigooni, A S.; University of Nevada Las Vegas

Purpose: Recently, different applicators are designed for treatment of the skin cancer such as scalp and legs, using Ir-192 HDR Brachytherapy Sources (IR-HDRS), Miniature Electronic Brachytherapy Sources (MEBXS), and External Electron Beam Radiation Therapy (EEBRT). Although, all of these methodologies may deliver the desired radiation dose to the skin, the dose to the underlying bone may become the limiting factor for selection of the optimum treatment technique. In this project the radiation dose delivered to the underlying bone has been evaluated as a function of the radiation source and thickness of the underlying bone. Methods: MC simulations were performed usingmore » MCNP5 code. In these simulations, the mono-energetic and non-divergent photon beams of 30 keV, 50 keV, and 70 keV for MEBXS, 380 keV photons for IR-HDRS, and 6 MeV mono-energetic electron beam for EEBRT were modeled. A 0.5 cm thick soft tissue (0.3 cm skin and 0.2 cm adipose) with underlying 0.5 cm cortical bone followed by 14 cm soft tissue are utilized for simulations. Results: Dose values to bone tissue as a function of beam energy and beam type, for a delivery of 5000 cGy dose to skin, were compared. These results indicate that for delivery of 5000 cGy dose to the skin surface with 30 keV, 50 keV, 70 keV of MEBXS, IR-HDRS, and EEBRT techniques, bone will receive 31750 cGy, 27450 cGy, 18550 cGy, 4875 cGy, and 10450 cGy, respectively. Conclusion: The results of these investigations indicate that, for delivery of the same skin dose, average doses received by the underlying bone are 5.2 and 2.2 times larger with a 50 keV MEBXS and EEBRT techniques than IR-HDRS, respectively.« less

Quantification of Fibrosis and Osteosclerosis in Myeloproliferative Neoplasms: A Computer-Assisted Image Study

PubMed Central

Teman, Carolin J.; Wilson, Andrew R.; Perkins, Sherrie L.; Hickman, Kimberly; Prchal, Josef T.; Salama, Mohamed E.

2010-01-01

Evaluation of bone marrow fibrosis and osteosclerosis in myeloproliferative neoplasms (MPN) is subject to interobserver inconsistency. Performance data for currently utilized fibrosis grading systems are lacking, and classification scales for osteosclerosis do not exist. Digital imaging can serve as a quantification method for fibrosis and osteosclerosis. We used digital imaging techniques for trabecular area assessment and reticulin-fiber quantification. Patients with all Philadelphia negative MPN subtypes had higher trabecular volume than controls (p ≤0.0015). Results suggest that the degree of osteosclerosis helps differentiate primary myelofibrosis from other MPN. Numerical quantification of fibrosis highly correlated with subjective scores, and interobserver correlation was satisfactory. Digital imaging provides accurate quantification for osteosclerosis and fibrosis. PMID:20122729

Relative stability of deep- versus shallow-side bone levels in angular proximal infrabony defects.

PubMed

Heins, P; Hartigan, M; Low, S; Chace, R

1989-01-01

The relative changes with time, in the position of the coronal margin of the mesial and distal bone of proximal, angular infrabony defects, were investigated. Tracings of the radiographs of 51 mandibular posterior sites, treated by flap curettage, with a mean post-surgical duration of 11.8 years, were measured using a digitizer pad. The group consisting of shallow-side sites (N = 51), exhibited no significant change in the bone height with time; however, there was a significant decrease in bone height in the deep-side group (N = 51). The mean area of proximal bone decreased significantly with time. The defects were divided into early (N = 25) and advanced (N = 26) angular groups, and then into deep- and shallow-side subgroups. In the early defect group, there was a significant decrease in the mean bone height of the deep-side subgroup. There were no differences in the changes of mean bone level of the remaining 3 subgroups with time. There was no correlation between changes in bone levels of adjacent mesial and distal sides of angular defects with time (r = 0.27). There was no difference between the deep- and shallow-side groups in the number of sites which gained, lost or evidenced no change in bone height. In the study population, the bone height of 73% of the deep-side, and 84% of the shallow-side sites was either unchanged or in a more coronal position.(ABSTRACT TRUNCATED AT 250 WORDS)

21 CFR 1311.45 - Requirements for registrants that allow powers of attorney to obtain CSOS digital certificates...

Code of Federal Regulations, 2010 CFR

2010-04-01

... attorney to obtain CSOS digital certificates under their DEA registration. 1311.45 Section 1311.45 Food and... PRESCRIPTIONS (Eff. 6-1-10) Obtaining and Using Digital Certificates for Electronic Orders § 1311.45 Requirements for registrants that allow powers of attorney to obtain CSOS digital certificates under their DEA...

47 CFR 32.5999 - General.

Code of Federal Regulations, 2014 CFR

2014-10-01

... switching expense 6210 Non-digital switching expense 6211 Digital electronic switching expense 6212... Circuit equipment expense 6232 Information origination/termination expense 6310 Station apparatus expense...

47 CFR 32.5999 - General.

Code of Federal Regulations, 2012 CFR

2012-10-01

... switching expense 6210 Non-digital switching expense 6211 Digital electronic switching expense 6212... Circuit equipment expense 6232 Information origination/termination expense 6310 Station apparatus expense...

47 CFR 32.5999 - General.

Code of Federal Regulations, 2013 CFR

2013-10-01

... switching expense 6210 Non-digital switching expense 6211 Digital electronic switching expense 6212... Circuit equipment expense 6232 Information origination/termination expense 6310 Station apparatus expense...

Microbial pathways and palaeoenvironmental conditions involved in the formation of phosphorite grains, Safaga District, Egypt

NASA Astrophysics Data System (ADS)

Salama, Walid; El-Kammar, Ahmed; Saunders, Martin; Morsy, Rania; Kong, Charlie

2015-07-01

Phosphatic grains of the shallow marine phosphorite deposits of Egypt are classified as either phosphatic bioclasts preserving biological structure (e.g. skeletal fragments such as fish bones and teeth) or phosphatic peloids and intraclasts. This study describes the destructive and constructive microbial pathways represented by bioerosion of bones by endolithic cyanobacteria and accretion of phosphatic peloids by bacteria. The palaeoenvironmental conditions and post-depositional/diagenetic history of these grains have also been considered. Scanning and transmission electron microscopy showed that the phosphatic peloids under transmitted light microscopy are composed mainly of microspheres (0.5 to 2.5 μm) similar in shape and size to coccoid-like bacteria. Chemical mapping showed that these microspheres are composed of carbonate-fluorapatite (CFA) and surrounded by degraded carbonaceous matrix. These grains are suggested to be reworked from pre-existing microbial mats during transgressive-regressive cycles affecting the southern Tethyan Campanian-Maastrichtian shallow continental shelf. The bioerosion of phosphatic bones is characterized by a network of meandering microborings that penetrated inward from the bone surface by endolithic cyanobacteria. The bioerosion of bones resulted in a gradual centripetal digestion and conversion of bones into micritic phosphate peloids. The bioerosion mechanism is probably started in the acidic sheath surrounding cyanobacteria followed by supersaturation of PO4 and reprecipitation of crystalline CFA as electron dense remineralized rims. Electron microprobe microanalyses showed that the remineralized microbored areas are higher in CaO, P2O5, and F and depleted in Cl, relative to unaltered bones. A gradual demineralization of remineralized rims followed by dissolution of cyanobacterial cells is probably occurred during diagenesis and meteoric water alteration leaving behind empty microborings. Bone exposed to meteoric water alteration is lower in CaO and P2O5 and higher in F and Cl than the unaltered bones. Understanding bone bioerosion has significant implications for palaeoenvironmental and taphonomic reconstruction, archaeological applications and a regional correlation of the late Cretaceous to Palaeogene phosphogenic province extending from Middle East to North Africa.

Modeling from Local to Subsystem Level Effects in Analog and Digital Circuits Due to Space Induced Single Event Transients

NASA Technical Reports Server (NTRS)

Perez, Reinaldo J.

2011-01-01

Single Event Transients in analog and digital electronics from space generated high energetic nuclear particles can disrupt either temporarily and sometimes permanently the functionality and performance of electronics in space vehicles. This work first provides some insights into the modeling of SET in electronic circuits that can be used in SPICE-like simulators. The work is then directed to present methodologies, one of which was developed by this author, for the assessment of SET at different levels of integration in electronics, from the circuit level to the subsystem level.

Statistical EMC: A new dimension electromagnetic compatibility of digital electronic systems

NASA Astrophysics Data System (ADS)

Tsaliovich, Anatoly

Electromagnetic compatibility compliance test results are used as a database for addressing three classes of electromagnetic-compatibility (EMC) related problems: statistical EMC profiles of digital electronic systems, the effect of equipment-under-test (EUT) parameters on the electromagnetic emission characteristics, and EMC measurement specifics. Open area test site (OATS) and absorber line shielded room (AR) results are compared for equipment-under-test highest radiated emissions. The suggested statistical evaluation methodology can be utilized to correlate the results of different EMC test techniques, characterize the EMC performance of electronic systems and components, and develop recommendations for electronic product optimal EMC design.

In vivo performance of two different hydroxyapatite coatings on titanium prepared by discharging in electrolytes.

PubMed

Yamamoto, Hiroki; Shibata, Yo; Tachikawa, Tetsuhiko; Miyazaki, Takashi

2006-07-01

This study reports a discharging method for bone-like carbonated HA (cHA)-coating (Ca/P 1.71) and stoichiometric HA (sHA)-coating (Ca/P 1.67) with micrometer order thicknesses on titanium plates, using modified body fluid and acidic calcium phosphate solutions, respectively. In vivo histological performance of the HA coatings prepared by discharging in electrolytes was evaluated. Bone-contact indexes of HA coatings were measured microscopically. Additionally, bone-coating interface was analyzed by scanning electron microscopy and the use of an electron probe microanalyzer. Results demonstrated that there was no significant difference in contact index between HA coatings. However, the cHA coating was practically replaced by immature bone, and the titanium metal substrate was directly connected to the bone structure whereas the sHA coating layer remained and was partially detached from the titanium metal substrate. Since detached coating particles are pathogens, and can cause peri-implantitis, the cHA coating was more favorable than the sHA coating even if contact index was equivalent to that of the sHA coating. It is thought that coating thickness and chemical composition of coatings are important for biological stability of implants. In conclusion, since bone-like thin cHA coating showed high osteoconductivity and bone replacement, bone-like HA is superior to sHA coating for use in dental implants.

Clinical, Morphological, and Molecular Evaluations of Bone Regeneration With an Additive Manufactured Osteosynthesis Plate.

PubMed

Thor, Andreas; Palmquist, Anders; Hirsch, Jan-Michaél; Rännar, Lars-Erik; Dérand, Per; Omar, Omar

2016-10-01

There is limited information on the biological status of bone regenerated with microvascular fibula flap combined with biomaterials. This paper describes the clinical, histological, ultrastructural, and molecular picture of bone regenerated with patient-customized plate, used for mandibular reconstruction in combination with microvascular osteomyocutaneous fibula flap. The plate was virtually planned and additively manufactured using electron beam melting. This plate was retrieved from the patient after 33 months. Microcomputed tomography, backscattered-scanning electron microscopy, histology, and quantitative-polymerase chain reaction were employed to evaluate the regenerated bone and the flap bone associated with the retrieved plate. At retrieval, the posterior two-thirds of the plate were in close adaptation with the underlying flap, whereas soft tissue was observed between the native mandible and the anterior one-third. The histological and structural analyses showed new bone regeneration, ingrowth, and osseointegration of the posterior two-thirds. The histological observations were supported by the gene expression analysis showing higher expression of bone formation and remodeling genes under the posterior two-thirds compared with the anterior one-third of the plate. The observation of osteocytes in the flap indicated its viability. The present data endorse the suitability of the customized, additively manufactured plate for the vascularized fibula mandibular reconstruction. Furthermore, the combination of the analytical techniques provides possibilities to deduce the structural and molecular characteristics of bone regenerated using this procedure.

Relationship between the v2PO4/amide III ratio assessed by Raman spectroscopy and the calcium content measured by quantitative backscattered electron microscopy in healthy human osteonal bone

NASA Astrophysics Data System (ADS)

Roschger, Andreas; Gamsjaeger, Sonja; Hofstetter, Birgit; Masic, Admir; Blouin, Stéphane; Messmer, Phaedra; Berzlanovich, Andrea; Paschalis, Eleftherios P.; Roschger, Paul; Klaushofer, Klaus; Fratzl, Peter

2014-06-01

Raman microspectroscopy and quantitative backscattered electron imaging (qBEI) of bone are powerful tools to investigate bone material properties. Both methods provide information on the degree of bone matrix mineralization. However, a head-to-head comparison of these outcomes from identical bone areas has not been performed to date. In femoral midshaft cross sections of three women, 99 regions (20×20 μ) were selected inside osteons and interstitial bone covering a wide range of matrix mineralization. As the focus of this study was only on regions undergoing secondary mineralization, zones exhibiting a distinct gradient in mineral content close to the mineralization front were excluded. The same regions were measured by both methods. We found a linear correlation (R2=0.75) between mineral/matrix as measured by Raman spectroscopy and the wt. %Mineral/(100-wt. %Mineral) as obtained by qBEI, in good agreement with theoretical estimations. The observed deviations of single values from the linear regression line were determined to reflect biological heterogeneities. The data of this study demonstrate the good correspondence between Raman and qBEI outcomes in describing tissue mineralization. The obtained correlation is likely sensitive to changes in bone tissue composition, providing an approach to detect potential deviations from normal bone.

Digital Libraries and the Continuum of Scholarly Communication.

ERIC Educational Resources Information Center

Borgman, Christine L.

2000-01-01

Explores the relationship between scholarly communication, an established research area receiving renewed interest, and digital libraries, a relatively new area of research. Stakeholders agree that the relationship structure inherent in scholarship has become unbalanced with the advent of electronic publishing, digital libraries, computer…

Computational segmentation of collagen fibers in bone matrix indicates bone quality in ovariectomized rat spine.

PubMed

Daghma, Diaa Eldin S; Malhan, Deeksha; Simon, Paul; Stötzel, Sabine; Kern, Stefanie; Hassan, Fathi; Lips, Katrin Susanne; Heiss, Christian; El Khassawna, Thaqif

2018-05-01

Bone loss varies according to disease and age and these variations affect bone cells and extracellular matrix. Osteoporosis rat models are widely investigated to assess mechanical and structural properties of bone; however, bone matrix proteins and their discrepant regulation of diseased and aged bone are often overlooked. The current study considered the spine matrix properties of ovariectomized rats (OVX) against control rats (Sham) at 16 months of age. Diseased bone showed less compact structure with inhomogeneous distribution of type 1 collagen (Col1) and changes in osteocyte morphology. Intriguingly, demineralization patches were noticed in the vicinity of blood vessels in the OVX spine. The organic matrix structure was investigated using computational segmentation of collagen fibril properties. In contrast to the aged bone, diseased bone showed longer fibrils and smaller orientation angles. The study shows the potential of quantifying transmission electron microscopy images to predict the mechanical properties of bone tissue.

Osseointegration of a 3D Printed Stemmed Titanium Dental Implant: A Pilot Study

PubMed Central

Tedesco, James; Lee, Bryan E. J.; Lin, Alex Y. W.; Binkley, Dakota M.; Delaney, Kathleen H.; Kwiecien, Jacek M.

2017-01-01

In this pilot study, a 3D printed Grade V titanium dental implant with a novel dual-stemmed design was investigated for its biocompatibility in vivo. Both dual-stemmed (n = 12) and conventional stainless steel conical (n = 4) implants were inserted into the tibial metaphysis of New Zealand white rabbits for 3 and 12 weeks and then retrieved with the surrounding bone, fixed, dehydrated, and embedded into epoxy resin. The implants were analyzed using correlative histology, microcomputed tomography, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The histological presence of multinucleated osteoclasts and cuboidal osteoblasts revealed active bone remodeling in the stemmed implant starting at 3 weeks and by 12 weeks in the conventional implant. Bone-implant contact values indicated that the stemmed implants supported bone growth along the implant from the coronal crest at both 3- and 12-week time periods and showed bone growth into microporosities of the 3D printed surface after 12 weeks. In some cases, new bone formation was noted in between the stems of the device. Conventional implants showed mechanical interlocking but did have indications of stress cracking and bone debris. This study demonstrates the comparable biocompatibility of these 3D printed stemmed implants in rabbits up to 12 weeks. PMID:29527226

Storing Blood Cells

NASA Technical Reports Server (NTRS)

1976-01-01

The National Cancer Institute worked with Goddard Space Flight Center to propose a solution to the blood-cell freezing problem. White blood cells and bone marrow are stored for future use by leukemia patients as a result of Goddard and Jet Propulsion Laboratory expertise in electronics and cryogenics. White blood cell and bone marrow bank established using freezing unit. Freezing unit monitors temperature of cells themselves. Thermocouple placed against polyethylene container relays temperature signals to an electronic system which controls small heaters located outside container. Heaters allow liquid nitrogen to circulate at constant temperature and maintain consistent freezing rate. Ability to freeze, store, and thaw white cells and bone marrow without damage is important in leukemia treatment.

Material model of pelvic bone based on modal analysis: a study on the composite bone.

PubMed

Henyš, Petr; Čapek, Lukáš

2017-02-01

Digital models based on finite element (FE) analysis are widely used in orthopaedics to predict the stress or strain in the bone due to bone-implant interaction. The usability of the model depends strongly on the bone material description. The material model that is most commonly used is based on a constant Young's modulus or on the apparent density of bone obtained from computer tomography (CT) data. The Young's modulus of bone is described in many experimental works with large variations in the results. The concept of measuring and validating the material model of the pelvic bone based on modal analysis is introduced in this pilot study. The modal frequencies, damping, and shapes of the composite bone were measured precisely by an impact hammer at 239 points. An FE model was built using the data pertaining to the geometry and apparent density obtained from the CT of the composite bone. The isotropic homogeneous Young's modulus and Poisson's ratio of the cortical and trabecular bone were estimated from the optimisation procedure including Gaussian statistical properties. The performance of the updated model was investigated through the sensitivity analysis of the natural frequencies with respect to the material parameters. The maximal error between the numerical and experimental natural frequencies of the bone reached 1.74 % in the first modal shape. Finally, the optimised parameters were matched with the data sheets of the composite bone. The maximal difference between the calibrated material properties and that obtained from the data sheet was 34 %. The optimisation scheme of the FE model based on the modal analysis data provides extremely useful calibration of the FE models with the uncertainty bounds and without the influence of the boundary conditions.

Cellular Ti-6Al-4V structures with interconnected macro porosity for bone implants fabricated by selective electron beam melting.

PubMed

Heinl, Peter; Müller, Lenka; Körner, Carolin; Singer, Robert F; Müller, Frank A

2008-09-01

Selective electron beam melting (SEBM) was successfully used to fabricate novel cellular Ti-6Al-4V structures for orthopaedic applications. Micro computer tomography (microCT) analysis demonstrated the capability to fabricate three-dimensional structures with an interconnected porosity and pore sizes suitable for tissue ingrowth and vascularization. Mechanical properties, such as compressive strength and elastic modulus, of the tested structures were similar to those of human bone. Thus, stress-shielding effects after implantation might be avoided due to a reduced stiffness mismatch between implant and bone. A chemical surface modification using HCl and NaOH induced apatite formation during in vitro bioactivity tests in simulated body fluid under dynamic conditions. The modified bioactive surface is expected to enhance the fixation of the implant in the surrounding bone as well as to improve its long-term stability.

Dark-field transmission electron microscopy of cortical bone reveals details of extrafibrillar crystals.

PubMed

Schwarcz, Henry P; McNally, Elizabeth A; Botton, Gianluigi A

2014-12-01

In a previous study we showed that most of the mineral in bone is present in the form of "mineral structures", 5-6nm-thick, elongated plates which surround and are oriented parallel to collagen fibrils. Using dark-field transmission electron microscopy, we viewed mineral structures in ion-milled sections of cortical human bone cut parallel to the collagen fibrils. Within the mineral structures we observe single crystals of apatite averaging 5.8±2.7nm in width and 28±19nm in length, their long axes oriented parallel to the fibril axis. Some appear to be composite, co-aligned crystals as thin as 2nm. From their similarity to TEM images of crystals liberated from deproteinated bone we infer that we are viewing sections through platy crystals of apatite that are assembled together to form the mineral structures. Copyright © 2014 Elsevier Inc. All rights reserved.

Development of electronic cinema projectors

NASA Astrophysics Data System (ADS)

Glenn, William E.

2001-03-01

All of the components for the electronic cinema are now commercially available. Sony has a high definition progressively scanned 24 frame per second electronic cinema camera. This can be recorded digitally on tape or film on hard drives in RAID recorders. Much of the post production processing is now done digitally by scanning film, processing it digitally, and recording it on film for release. Fiber links and satellites can transmit cinema program material to theaters in real time. RAID or tape recorders can play programs for viewing at a much lower cost than storage on film. Two companies now have electronic cinema projectors on the market. Of all of the components, the electronic cinema projector is the most challenging. Achieving the resolution, light, output, contrast ratio, and color rendition all at the same time without visible artifacts is a difficult task. Film itself is, of course, a form of light-valve. However, electronically modulated light uses other techniques rather than changes in density to control the light. The optical techniques that have been the basis for many electronic light-valves have been under development for over 100 years. Many of these techniques are based on optical diffraction to modulate the light. This paper will trace the history of these techniques and show how they may be extended to produce electronic cinema projectors in the future.

[The effect of osteogenic inducer on healing of tooth extraction sockets].

PubMed

Chen, Junliang; Shan, Chuncheng; He, Yun; Xia, Delin

2012-06-01

To study the effect of osteogenic inducer (dexamethasone, beta-sodium glycerophosphate and Vitamin C) carried by gelatin sponge on healing and remodeling of tooth extraction sockets. Fifty rabbits were selected. After extracting the first premolars of bilateral maxillary, the right side tooth extraction sockets were filled with gelatin sponge containing osteogenic inducer as experimental side, tooth extraction sockets on left side were filled with gelatin sponge as control. Every ten rabbits were executed at the end of 1, 2, 4, 8, 12 weeks after tooth extraction. Bone density was measured through digital X-ray images. The specimens were examined by histology. The absorption height of alveolar bone at 12 weeks was measured. X-ray measurement showed that the bone density of experimental side was higher than that of control side at 2, 4, 8, 12 weeks, the difference had statistical significance (P<0.01). The histology examination showed that new bone formation in tooth extraction sockets of experimental side was earlier than that in control side. The absorptional height of alveolar bone had significant difference between experimental side and control side (P<0.01), of which experimental side was less. Filling the osteogenic inducer in tooth extraction sockets can promote the healing and new bone formation and prevent from alveolar bone absorption.

A potential new diagnostic tool to aid DNA analysis from heat compromised bone using colorimetry: A preliminary study.

PubMed

Fredericks, Jamie D; Ringrose, Trevor J; Dicken, Anthony; Williams, Anna; Bennett, Phil

2015-03-01

Extracting viable DNA from many forensic sample types can be very challenging, as environmental conditions may be far from optimal with regard to DNA preservation. Consequently, skeletal tissue can often be an invaluable source of DNA. The bone matrix provides a hardened material that encapsulates DNA, acting as a barrier to environmental insults that would otherwise be detrimental to its integrity. However, like all forensic samples, DNA in bone can still become degraded in extreme conditions, such as intense heat. Extracting DNA from bone can be laborious and time-consuming. Thus, a lot of time and money can be wasted processing samples that do not ultimately yield viable DNA. We describe the use of colorimetry as a novel diagnostic tool that can assist DNA analysis from heat-treated bone. This study focuses on characterizing changes in the material and physical properties of heated bone, and their correlation with digitally measured color variation. The results demonstrate that the color of bone, which serves as an indicator of the chemical processes that have occurred, can be correlated with the success or failure of subsequent DNA amplification. Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

Histomorphometric Parameters of the Growth Plate and Trabecular Bone in Wild-Type and Trefoil Factor Family 3 (Tff3)-Deficient Mice Analyzed by Free and Open-Source Image Processing Software.

PubMed

Bijelić, Nikola; Belovari, Tatjana; Stolnik, Dunja; Lovrić, Ivana; Baus Lončar, Mirela

2017-08-01

Trefoil factor family 3 (Tff3) peptide is present during intrauterine endochondral ossification in mice, and its deficiency affects cancellous bone quality in secondary ossification centers of mouse tibiae. The aim of this study was to quantitatively analyze parameters describing the growth plate and primary ossification centers in tibiae of 1-month-old wild-type and Tff3 knock-out mice (n=5 per genotype) by using free and open-source software. Digital photographs of the growth plates and trabecular bone were processed by open-source computer programs GIMP and FIJI. Histomorphometric parameters were calculated using measurements made with FIJI. Tff3 knock-out mice had significantly smaller trabecular number and significantly larger trabecular separation. Trabecular bone volume, trabecular bone surface, and trabecular thickness showed no significant difference between the two groups. Although such histomorphological differences were found in the cancellous bone structure, no significant differences were found in the epiphyseal plate histomorphology. Tff3 peptide probably has an effect on the formation and quality of the cancellous bone in the primary ossification centers, but not through disrupting the epiphyseal plate morphology. This work emphasizes the benefits of using free and open-source programs for morphological studies in life sciences.

On-top plasty using a free metacarpal head graft for lengthening of proximal phalanx in symbrachydactyly--a case report.

PubMed

Iba, Kousuke; Wada, Takuro; Yamashita, Toshihiko

2013-01-01

A three-year old patient with symbrachydactyly (didactyly type) presented with a little finger that was too short to allow pinching and consisting of a floppy soft-tissue envelope with hypoplastic phalanges, although the thumb was functional. As the proximal phalanx was too small to permit distraction lengthening or conventional bone grafting, on-top plasty using a 4th metacarpal graft with a cartilage head was undertaken for lengthening the proximal phalanx of the little finger for pinch reconstruction. At ten weeks after surgery, the patient achieved satisfactory pinch function due to the lengthened and bone-stabilised postoperative digit and reconstruction of functional proximal interphalangeal joint. In addition, the grafted metacarpal demonstrated satisfactory bone growth throughout the six-year follow-up period.

Supervised Coursework as a Way of Improving Motivation in the Learning of Digital Electronics

ERIC Educational Resources Information Center

Rengel, R.; Martin, M. J.; Vasallo, B. G.

2012-01-01

This paper presents a series of activities and educational strategies related to the teaching of digital electronics in computer engineering. The main objective of these methodologies was to develop a final tutored coursework to be carried out by the students in small teams. This coursework was conceived as consisting of advanced problems or small…

Alterations in mineral properties of zebrafish skeletal bone induced by liliput dtc232 gene mutation

NASA Astrophysics Data System (ADS)

Wang, Xiu-Mei; Cui, Fu-Zhai; Ge, Jun; Ma, Chen

2003-11-01

The alterations of mineral properties of bone by gene mutation in the zebrafish, which is associated with abnormal bone mineralization and bone diseases, were reported for the first time in this paper. Transmission electron microscope (TEM), Fourier transform infrared microspectroscopy (FTIRM) and thermogravimetric analysis (TGA) were used to investigate the changes in the mineral. Significant variations of the morphologies of the minerals and the mineral/matrix ratio after liliputdtc232(lil) gene mutation have been observed. The morphologies of the minerals, examined by TEM, revealed that the mutated mineral was in bigger size and the shape was block shaped but not plate shaped. The results of FTIRM indicated that the lil mutant zebrafish skeleton exhibited a greater mineral/matrix ratio (phosphate/matrix=4.86±0.28) than that of wild-type zebrafish bone (phosphate/matrix=4.17±0.67), which was confirmed by TGA analysis. Furthermore, the mineral of lil bone became less mature and crystalline with more ion substitutions. And the selected areas electron diffraction (SAED) patterns showed that the main crystal phases of the two type fishes were both hydroxyapatite. In addition, we have discussed the relationship among the mineral properties, nanomechanical properties and biomineralization process.

77 FR 14955 - DoD Information Assurance Scholarship Program (IASP)

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-14

... IA and information technology (IT) management, technical, digital and multimedia forensics, cyber..., digital and multimedia forensics, electrical engineering, electronics engineering, information security...

Digital cinema video compression

NASA Astrophysics Data System (ADS)

Husak, Walter

2003-05-01

The Motion Picture Industry began a transition from film based distribution and projection to digital distribution and projection several years ago. Digital delivery and presentation offers the prospect to increase the quality of the theatrical experience for the audience, reduce distribution costs to the distributors, and create new business opportunities for the theater owners and the studios. Digital Cinema also presents an opportunity to provide increased flexibility and security of the movies for the content owners and the theater operators. Distribution of content via electronic means to theaters is unlike any of the traditional applications for video compression. The transition from film-based media to electronic media represents a paradigm shift in video compression techniques and applications that will be discussed in this paper.

Computer-assisted analysis of cervical vertebral bone age using cephalometric radiographs in Brazilian subjects.

PubMed

Caldas, Maria de Paula; Ambrosano, Gláucia Maria Bovi; Haiter Neto, Francisco

2010-01-01

The aims of this study were to develop a computerized program for objectively evaluating skeletal maturation on cephalometric radiographs, and to apply the new method to Brazilian subjects. The samples were taken from the patient files of Oral Radiological Clinics from the North, Northeast, Midwest and South regions of the country. A total of 717 subjects aged 7.0 to 15.9 years who had lateral cephalometric radiographs and hand-wrist radiographs were selected. A cervical vertebral computerized analysis was created in the Radiocef Studio 2 computer software for digital cephalometric analysis, and cervical vertebral bone age was calculated using the formulas developed by Caldas et al.17 (2007). Hand-wrist bone age was evaluated by the TW3 method. Analysis of variance (ANOVA) and the Tukey test were used to compare cervical vertebral bone age, hand-wrist bone age and chronological age (P < 0.05). No significant difference was found between cervical vertebral bone age and chronological age in all regions studied. When analyzing bone age, it was possible to observe a statistically significant difference between cervical vertebral bone age and hand-wrist bone age for female and male subjects in the North and Northeast regions, as well as for male subjects in the Midwest region. No significant difference was observed between bone age and chronological age in all regions except for male subjects in the North and female subjects in the Northeast. Using cervical vertebral bone age, it might be possible to evaluate skeletal maturation in an objective manner using cephalometric radiographs.

Digital Health Services and Digital Identity in Alberta.

PubMed

McEachern, Aiden; Cholewa, David

2017-01-01

The Government of Alberta continues to improve delivery of healthcare by allowing Albertans to access their health information online. Alberta is the only province in Canada with provincial electronic health records for all its citizens. These records are currently made available to medical practitioners, but Alberta Health believes that providing Albertans access to their health records will transform the delivery of healthcare in Alberta. It is important to have a high level of assurance that the health records are provided to the correct Albertan. Alberta Health requires a way for Albertans to obtain a digital identity with a high level of identity assurance prior to releasing health records via the Personal Health Portal. Service Alberta developed the MyAlberta Digital ID program to provide a digital identity verification service. The Ministry of Health is leveraging MyAlberta Digital ID to enable Albertans to access their personal health records through the Personal Health Portal. The Government of Alberta is advancing its vision of patient-centred healthcare by enabling Albertans to access a trusted source for health information and their electronic health records using a secure digital identity.

Monitoring of bone regeneration process by means of texture analysis

NASA Astrophysics Data System (ADS)

Kokkinou, E.; Boniatis, I.; Costaridou, L.; Saridis, A.; Panagiotopoulos, E.; Panayiotakis, G.

2009-09-01

An image analysis method is proposed for the monitoring of the regeneration of the tibial bone. For this purpose, 130 digitized radiographs of 13 patients, who had undergone tibial lengthening by the Ilizarov method, were studied. For each patient, 10 radiographs, taken at an equal number of postoperative successive time moments, were available. Employing available software, 3 Regions Of Interest (ROIs), corresponding to the: (a) upper, (b) central, and (c) lower aspect of the gap, where bone regeneration was expected to occur, were determined on each radiograph. Employing custom developed algorithms: (i) a number of textural features were generated from each of the ROIs, and (ii) a texture-feature based regression model was designed for the quantitative monitoring of the bone regeneration process. Statistically significant differences (p < 0.05) were derived for the initial and the final textural features values, generated from the first and the last postoperatively obtained radiographs, respectively. A quadratic polynomial regression equation fitted data adequately (r2 = 0.9, p < 0.001). The suggested method may contribute to the monitoring of the tibial bone regeneration process.

Fracture characterization of human cortical bone under mode II loading using the end-notched flexure test.

PubMed

Silva, F G A; de Moura, M F S F; Dourado, N; Xavier, J; Pereira, F A M; Morais, J J L; Dias, M I R; Lourenço, P J; Judas, F M

2017-08-01

Fracture characterization of human cortical bone under mode II loading was analyzed using a miniaturized version of the end-notched flexure test. A data reduction scheme based on crack equivalent concept was employed to overcome uncertainties on crack length monitoring during the test. The crack tip shear displacement was experimentally measured using digital image correlation technique to determine the cohesive law that mimics bone fracture behavior under mode II loading. The developed procedure was validated by finite element analysis using cohesive zone modeling considering a trapezoidal with bilinear softening relationship. Experimental load-displacement curves, resistance curves and crack tip shear displacement versus applied displacement were used to validate the numerical procedure. The excellent agreement observed between the numerical and experimental results reveals the appropriateness of the proposed test and procedure to characterize human cortical bone fracture under mode II loading. The proposed methodology can be viewed as a novel valuable tool to be used in parametric and methodical clinical studies regarding features (e.g., age, diseases, drugs) influencing bone shear fracture under mode II loading.

Annulus Fibrosus Can Strip Hyaline Cartilage End Plate from Subchondral Bone: A Study of the Intervertebral Disk in Tension.

PubMed

Balkovec, Christian; Adams, Michael A; Dolan, Patricia; McGill, Stuart M

2015-10-01

Study Design Biomechanical study on cadaveric spines. Objective Spinal bending causes the annulus to pull vertically (axially) on the end plate, but failure mechanisms in response to this type of loading are poorly understood. Therefore, the objective of this study was to identify the weak point of the intervertebral disk in tension. Methods Cadaveric motion segments (aged 79 to 88 years) were dissected to create midsagittal blocks of tissue, with ∼10 mm of bone superior and inferior to the disk. From these blocks, 14 bone-disk-bone slices (average 4.8 mm thick) were cut in the frontal plane. Each slice was gripped by its bony ends and stretched to failure at 1 mm/s. Mode of failure was recorded using a digital camera. Results Of the 14 slices, 10 failed by the hyaline cartilage being peeled off the subchondral bone, with the failure starting opposite the lateral annulus and proceeding medially. Two slices failed by rupturing of the trabecular bone, and a further two failed in the annulus. Conclusions The hyaline cartilage-bone junction is the disk's weak link in tension. These findings provide a plausible mechanism for the appearance of bone and cartilage fragments in herniated material. Stripping cartilage from the bony end plate would result in the herniated mass containing relatively stiff cartilage that does not easily resorb.

Dentoalveolar mandibular changes with self-ligating versus conventional bracket systems: A CBCT and dental cast study

PubMed Central

de Almeida, Marcio Rodrigues; Futagami, Cristina; Conti, Ana Cláudia de Castro Ferreira; Oltramari-Navarro, Paula Vanessa Pedron; Navarro, Ricardo de Lima

2015-01-01

OBJECTIVE: The aim of the present study was to compare dentoalveolar changes in mandibular arch, regarding transversal measures and buccal bone thickness, in patients undergoing the initial phase of orthodontic treatment with self-ligating or conventional bracket systems. METHODS: A sample of 25 patients requiring orthodontic treatment was assessed based on the bracket type. Group 1 comprised 13 patients bonded with 0.022-in self-ligating brackets (SLB). Group 2 included 12 patients bonded with 0.022-in conventional brackets (CLB). Cone-beam computed tomography (CBCT) scans and a 3D program (Dolphin) assessed changes in transversal width of buccal bone (TWBB) and buccal bone thickness (BBT) before (T1) and 7 months after treatment onset (T2). Measurements on dental casts were performed using a digital caliper. Differences between and within groups were analyzed by Student's t-test; Pearson correlation coefficient was also calculated. RESULTS: Significant mandibular expansion was observed for both groups; however, no significant differences were found between groups. There was significant decrease in mandibular buccal bone thickness and transversal width of buccal bone in both groups. There was no significant correlation between buccal bone thickness and dental arch expansion. CONCLUSIONS: There were no significant differences between self-ligating brackets and conventional brackets systems regarding mandibular arch expansion and changes in buccal bone thickness or transversal width of buccal bone. PMID:26154456

Three-dimensional virtual bone bank system for selecting massive bone allograft in orthopaedic oncology.

PubMed

Wu, Zhigang; Fu, Jun; Wang, Zhen; Li, Xiangdong; Li, Jing; Pei, Yanjun; Pei, Guoxian; Li, Dan; Guo, Zheng; Fan, Hongbin

2015-06-01

Although structural bone allografts have been used for years to treat large defects caused by tumour or trauma, selecting the most appropriate allograft is still challenging. The objectives of this study were to: (1) describe the establishment of a visual bone bank system and workflow of allograft selection, and (2) show mid-term follow-up results of patients after allograft implantation. Allografts were scanned and stored in Digital Imaging and Communications in Medicine (DICOM) files. Then, image segmentation was conducted and 3D model reconstructed to establish a visual bone bank system. Based on the volume registration method, allografts were selected after a careful matching process. From November 2010 to June 2013, with the help of the Computer-assisted Orthopaedic Surgery (CAOS) navigation system, the allografts were implanted in 14 patients to fill defects after tumour resection. By combining the virtual bone bank and CAOS, selection time was reduced and matching accuracy was increased. After 27.5 months of follow-up, the mean Musculoskeletal Tumor Society (MSTS) 93 functional score was 25.7 ± 1.1 points. Except for two patients with pulmonary metastases, 12 patents were alive without evidence of disease at the time this report was written. The virtual bone bank system was helpful for allograft selection, tumour excision and bone reconstruction, thereby improving the safety and effectiveness of limb-salvage surgery.

[CLINICAL APPLICATION OF THREE DIMENSIONAL PRINTED NAVIGATION TEMPLATES FOR TREATMENT OF OSTEONECROSIS OF FEMORAL HEAD WITH PEDICLED ILIAC BONE GRAFT].

PubMed

Yu, Kaifu; Xu, Yongqing; Tan, Hongbo; He, Xiaoqing; Cai, Dixin; Zhou, Tianhua; Luo, Haotian; Duan, Jiazhang

2016-03-01

To investigate the feasibility and early effectiveness to treat osteonecrosis of the femoral head (ONFH) with pedicled iliac bone graft assisted by individual digital design and three dimensional (3D) printed navigation templates. Between February and June 2014, 15 patients (24 hips) with ONFH underwent pedicled iliac bone graft assisted by individual digital design and 3D printed navigation templates. There were 11 males (17 hips) and 4 females (7 hips) with a mean age of 38 years (range, 18-56 years) and a mean disease duration of 7.5 months (range, 1-24 months); the left hip was involved in 2 cases, the right hip in 4 cases, and both hips in 9 cases. There were 7 cases (12 hips) of steroid-induced ONFH, 5 cases (8 hips) of alcohol-induced ONFH, 1 case (1 hip) of traumatic ONFH, and 2 cases (3 hips) of idiopathic ONFH. The preoperative Harris score was 56.60 ± 6.97. According to Association Research Circulation Osseous (ARCO) staging system, 5 hips were classified as stage IIB, 8 hips as stage IIC, 6 hips as stage IIIB, and 5 hips as stage IIIC. The navigation templates were designed and printed to assist accurate location and debridement of necrosis area according to preoperative CT scanning at the beginning of pedicled iliac bone grafting procedure. The mean operation time was 135 minutes (range, 120-160 minutes), mean amount of bleeding was 255 mL (range, 200-300 mL). All the wounds healed primarily, no complication of deep vein thrombosis or infection was observed. All patients were followed up 12-16 months (mean, 14 months). The location of necrosis area was in accordance with preoperative design, which was removed completely without penetration of joint surface, pedicled iliac bone graft was performed at the right site according to postoperative imaging examination. Radiographically, graft fusion was achieved at 2.7 months (range, 2-3 months) in all patients. All the hips had no collapse during follow-up. Hip pain was relieved, and range of motion was improved. The Harris score was significantly improved to 89.53 ± 5.83 at last follow-up (t = 14.3 19, P = 0.000). The results were excellent in 12 hips, good in 10 hips, and fair in 2 hips according to Harris score standard. Pedicled iliac bone graft assisted by individual digital design and 3D printed navigation templates for treatment of adult ONFH has the advantages of accurate location and complete debridement of necrosis area, so satisfactory results can be obtained.

Cell Mechanisms of Bone Tissue Loss Under Space Flight Conditions

NASA Astrophysics Data System (ADS)

Rodionova, Natalia

Investigations on the space biosatellites has shown that the bone skeleton is one of the most im-portant targets of the effect space flight factors on the organism. Bone tissue cells were studied by electron microscopy in biosamples of rats' long bones flown on the board american station "SLS-2" and in experiments with modelling of microgravity ("tail suspension" method) with using autoradiography. The analysis of data permits to suppose that the processes of remod-eling in bone tissue at microgravity include the following succession of cell-to-cell interactions. Osteocytes as mechanosensory cells are first who respond to a changing "mechanical field". The next stage is intensification of osteolytic processes in osteocytes, leading to a volume en-largement of the osteocytic lacunae and removal of the "excess bone". Then mechanical signals have been transmitted through a system of canals and processes of the osteocytic syncitium to certain superficial bone zones and are perceived by osteoblasts and bone-lining cells (superficial osteocytes), as well as by the bone-marrow stromal cells. The sensitivity of stromal cells, pre-osteoblasts and osteoblasts, under microgravity was shown in a number of works. As a response to microgravity, the system of stromal cells -preosteoblasts -osteoblasts displays retardation of proliferation, differentiation and specific functions of osteogenetic cells. This is supported by the 3H-thymidine studies of the dynamics of differentiation of osteogenetic cells in remodeling zones. But unloading is not adequate and in part of the osteocytes are apoptotic changes as shown by our electron microscopic investigations. An osteocytic apoptosis can play the role in attraction the osteoclasts and in regulation of bone remodeling. The apoptotic bodies with a liquid flow through a system of canals are transferred to the bone surface, where they fulfil the role of haemoattractants for monocytes come here and form osteoclasts. The osteoclasts destroy bone tissue. The macrophages are incorporated into resorption lacunaes and utilize the organic matrix and cellular detritus. The products are secreted to remodeling zones and act as haemoattractants for recruiting and subsequent differentiation here of the osteogenic precursor cells. However, as shown by our results with 3H-glycine, in absence of mechanical stimulus the activization of osteoblastogenesis either doesn't occur, or takes place on a smaller scale. According to our electron-microscopic data a load deficit leads to an adaptive differentiation of fibroblasts and adipocytes in this remodeling zones. This sequence of events is considered as a mechanism of bone tissue loss which underlies the development of osteopenia and osteoporosis under space flight condition.

Consumer protection act for digital products

NASA Astrophysics Data System (ADS)

Hampel, Viktor E.

1996-03-01

This report proposes a `Consumer Protection Act for Digital Products' to support electronic commerce and to control the increasing abuse and lack of security on the national information highways. Patterned after the `Food and Drug Act of 1906 (21 USC)' and subsequent legislation, a new agency similar to that of the FDA would have the authority `to develop administrative policy with regard to the safety, effectiveness, and labeling of digital products and their communications for human use, and to review and evaluate new applications of such products.' Specifically, it is proposed that standards, originally developed by the defense industry for the labeling, enveloping, and authentication of digital products delivered to the Government, be extended to promote global electronic commerce by protecting the intellectual property rights of producers, establishing their liability for the end-use of digital products, and give consumers means for informed decision making and purchase.

Evidence for arrested bone formation during spaceflight

NASA Technical Reports Server (NTRS)

Turner, R. T.; Bobyn, J. D.; Duvall, P.; Morey, E. R.; Baylink, D. J.; Spector, M.

1982-01-01

Addressing the question of whether the bone formed in space is unusual, the morphology of bone made at the tibial diaphysis of rats before, during, and after spaceflight is studied. Evidence of arrest lines in the bone formed in space is reported suggesting that bone formation ceases along portions of the periosteum during spaceflight. Visualized by microradiography, the arrest lines are shown to be less mineralized than the surrounding bone matrix. When viewed by scanning electron microscopy, it is seen that bone fractures more readily at the site of an arrest line. These observations are seen as suggesting that arrest lines are a zone of weakness and that their formation may result in decreased bone strength in spite of normalization of bone formation after flight. The occurrence, location, and morphology of arrest lines are seen as suggesting that they are a visible result of the phenomenon of arrested bone formation.

Mark 3 wideband digital recorder in perspective

NASA Technical Reports Server (NTRS)

Hinteregger, H. F.

1980-01-01

The tape recorder used for the Mark 3 data acquisition and processing system is compared with earlier very long baseline interferometry recorders. Wideband 33-1/3 kbpi digital channel characteristics of instrumentation recorders and of a modern video cassette recorder are illustrated. Factors which influenced selection of the three major commercial components (transport, heads, and tape) are discussed. A brief functional description and the reasons for development of efficient signal electronics and necessary auxiliary control electronics are given. The design and operation of a digital bit synchronizer is illustrated as an example of the high degree of simplicity achieved.

In-Orbit Performance of the Digital Electronics for the X-Ray Microcalorimeter Onboard the Hitomi Satellite

NASA Astrophysics Data System (ADS)

Tsujimoto, M.; Tashiro, M. S.; Ishisaki, Y.; Yamada, S.; Seta, H.; Mitsuda, K.; Boyce, K. R.; Eckart, M. E.; Kilbourne, C. A.; Leutenegger, M. A.; Porter, F. S.; Kelley, R. L.

2018-03-01

The pulse shape processor is the onboard digital electronics unit of the X-ray microcalorimeter instrument—the soft X-ray spectrometer—onboard the Hitomi satellite. It processes X-ray events using the optimum filtering with limited resources. It was operated for 36 days in orbit continuously without issues and met the requirement of processing a 150 s^{-1} event rate during the observation of bright sources. Here, we present the results obtained in orbit, focusing on its performance as the onboard digital signal processing unit of an X-ray microcalorimeter.

75 FR 6704 - In the Matter of Certain Mobile Telephones and Wireless Communication Devices Featuring Digital...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-10

... Respondents Samsung Electronics Co., Ltd., Samsung Electronics America, Inc., and Samsung Telecommunications... with respect to Samsung Electronics Co., Ltd., Samsung Electronics America, Inc., and Samsung... Electronics Co., Ltd., Samsung Electronics America, Inc., Samsung Telecommunications America, LLC...

Advanced Electronic Systems. Curriculum Guide for Technology Education.

ERIC Educational Resources Information Center

Patrick, Dale R.

This curriculum for a 1-semester or 1-year course in electronics is designed to take students from basic through advanced electronic systems. It covers several electronic areas, such as digital electronics, communication electronics, industrial process control, instrumentation, programmable controllers, and robotics. The guide contains…

A Digital Library in the Mid-Nineties, Ahead or On Schedule?

ERIC Educational Resources Information Center

Dijkstra, Joost

1994-01-01

Discussion of the future possibilities of digital library systems highlights digital projects developed at Tilburg University (Netherlands). Topics addressed include online access to databases; electronic document delivery; agreements between libraries and Elsevier Science publishers to provide journal articles; full text document delivery; and…

Electronic Library: A TERI Experiment.

ERIC Educational Resources Information Center

Kar, Debal C.; Deb, Subrata; Kumar, Satish

2003-01-01

Discusses the development of Electronic Library at TERI (The Energy and Resources Institute, New Delhi). Highlights include: hardware and software used; the digital library/Virtual Electronic Library; directory of Internet journals; virtual reference resources; electronic collection/Physical Electronic Library; downloaded online full-length…

Tissue heterogeneity in the anterior chest wall and its influence on radiation therapy of the internal mammary lymph nodes.

PubMed

Lindskoug, B; Hultborn, A

1976-04-01

The density (g cm-3) and electron density (cm-3) of material from the anterior chest wall was determined. On the average, the difference in density between rib bone and intercostal soft tissue amounted to 17 per cent, while the difference in electron density was 7 per cent. The attenuation of high-energy electrons in specimens of rib bone, costal cartilage and sternum was determined by an experimental technique, using dosimeters of TLD material. The results of determinations of attenuation of 10 and 13 MeV electrons in fresh specimens are presented. It is concluded that electron radiation in the energy range of 10 to 13 MeV can be utilized for irradiation of lymph glands along the internal thoracic vessels without risk of underdosage.

Comparison of Two Methods for the Measurement of Medial and Lateral Metapodial Bones in Karagouniko Sheep (Ovis aries, L. 1758) and Hellenic Goat (Capra hircus, L. 1758)

PubMed Central

Pourlis, Aris; Chatzis, Theodoros; Katsoulos, Panagiotis

2014-01-01

The objective of this study was to compare the metapodial lengths of sheep and goats measured with a caliper with those measured using a 2-dimensional digital method. Complementarily, the lengths of medial and lateral metapodials in these species were compared. The limbs of 30 ewes and 30 goats were used. After preparation, the lateral and medial length of the metacarpals and metatarsals were measured twice with a caliper. Afterwards, each bone was scanned and the same lengths were digitally measured twice using commercial software. Data analysis revealed strong linear relationship between the two methods but the absolute relative deviation of the measurements with the caliper was significantly higher than those with the 2-dimensional method (P < 0.05). All lengths measured with the caliper were significantly higher compared to those measured with the 2-dimensional method (P < 0.05). In goats, the lateral length of both metacarpals and metatarsals was significantly higher than medial length (P < 0.05); in sheep the lateral length was significantly higher compared to the medial one only in metatarsal bones (P < 0.05). In conclusion, the 2-dimensional method is more accurate for the measurement of the metapodials' length than the caliper and there is asymmetry between the medial and lateral metapodials in these species. PMID:25530882

Real-time three-dimensional digital image correlation for biomedical applications

NASA Astrophysics Data System (ADS)

Wu, Rong; Wu, Hua; Arola, Dwayne; Zhang, Dongsheng

2016-10-01

Digital image correlation (DIC) has been successfully applied for evaluating the mechanical behavior of biological tissues. A three-dimensional (3-D) DIC system has been developed and applied to examining the motion of bones in the human foot. To achieve accurate, real-time displacement measurements, an algorithm including matching between sequential images and image pairs has been developed. The system was used to monitor the movement of markers which were attached to a precisely motorized stage. The accuracy of the proposed technique for in-plane and out-of-plane measurements was found to be -0.25% and 1.17%, respectively. Two biomedical applications were presented. In the experiment involving the foot arch, a human cadaver lower leg and foot specimen were subjected to vertical compressive loads up to 700 N at a rate of 10 N/s and the 3-D motions of bones in the foot were monitored in real time. In the experiment involving distal tibio fibular syndesmosis, a human cadaver lower leg and foot specimen were subjected to a monotonic rotational torque up to 5 Nm at a speed of 5 deg per min and the relative displacements of the tibia and fibula were monitored in real time. Results showed that the system could reach a frequency of up to 16 Hz with 6 points measured simultaneously. This technique sheds new lights on measuring 3-D motion of bones in biomechanical studies.

An evaluation of nasal bone and aperture shape among three South African populations.

PubMed

McDowell, Jennifer L; Kenyhercz, Michael W; L'Abbé, Ericka N

2015-07-01

Reliable and valid population specific standards are necessary to accurately develop a biological profile, which includes an estimation of peer-reported social identification (Hefner, 2009). During the last 300 years, colonialism, slavery and apartheid created geographic, physical and social divisions of population groups in South Africa. The purpose of this study was to evaluate variation in nasal bone and aperture shape in a modern population of black, white, and coloured South Africans using standard craniometric variables and geometric morphometrics, namely general Procrustes and elliptical Fourier analyses. Fourteen standard landmarks were digitally recorded or computationally derived from 310 crania using a 3D coordinate digitizer for discriminant function, principal components and generalized Procrustes analyses. For elliptical Fourier analysis, outlines of the nasal aperture were generated from standardized photographs. All classification accuracies were better than chance; the lowest accuracies were for coloured and the highest accuracies were for white South Africans. Most difficulties arose in distinguishing coloured and black South African groups from each other. Generally, misclassifications were noted between the sexes within each group rather than among groups, which suggests that sex has less influence on nasal bone and aperture shape than ancestry. Quantifiable variation in shape of the nasal aperture region between white and non-white South African groups was observed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Effect of nickel-titanium shape memory metal alloy on bone formation.

PubMed

Kapanen, A; Ryhänen, J; Danilov, A; Tuukkanen, J

2001-09-01

The aim of this study was to determine the biocompatibility of NiTi alloy on bone formation in vivo. For this purpose we used ectopic bone formation assay which goes through all the events of bone formation and calcification. Comparisons were made between Nitinol (NiTi), stainless steel (Stst) and titanium-aluminium (6%)-vanadium (4%) alloy (Ti-6Al-4V), which were implanted for 8 weeks under the fascia of the latissimus dorsi muscle in 3-month-old rats. A light-microscopic examination showed no chronic inflammatory or other pathological findings in the induced ossicle or its capsule. New bone replaced part of the decalcified matrix with mineralized new cartilage and bone. The mineral density was measured with peripheral quantitative computed tomography (pQCT). The total bone mineral density (BMD) values were nearly equal between the control and the NiTi samples, the Stst samples and the Ti-6Al-4V samples had lower BMDs. Digital image analysis was used to measure the combined area of new fibrotic tissue and original implanted bone matrix powder around the implants. There were no significant differences between the implanted materials, although Ti-6Al-4V showed the largest matrix powder areas. The same method was used for measurements of proportional cartilage and new bone areas in the ossicles. NiTi showed the largest cartilage area (p < or = 0.05). Between implant groups the new bone area was largest in NiTi. We conclude that NiTi has good biocompatibility, as its effects on ectopic bone formation are similar to those of Stst, and that the ectopic bone formation assay developed here can be used for biocompatibility studies.

Prevalence of Dental Implants and Evaluation of Peri-implant Bone Levels in Patients Presenting to a Dental School: A Radiographic Cross-Sectional 2-Year Study.

PubMed

Alkan, Eylem Ayhan; Mau, Lian Ping; Schoolfield, John; Guest, Gary F; Cochran, David L

To evaluate the number of patients with dental implants who present to a dental school clinic for screening and to report the prevalence of peri-implant bone level change detected on digital panoramic radiographs of those subjects. Patient screening files for 9,422 patients over a 2-year period were examined to see how many patients presented with dental implants. Those patients with at least one implant were further evaluated by measuring the bone level on the mesial and distal sides of the implant using the screening radiograph. A total of 187 patients (2%) had at least one implant. In regard to implants, 423 were examined and 146 (33%) had no detectable bone loss defined as bone level below the top of the implant. When thresholds of bone loss were evaluated, 109 implants (25%) had ≥ 2 mm of bone loss on either the mesial or distal sides or both. The median bone loss was 1.74 mm for the 277 implants with detectable bone loss and 2.97 mm for the 109 implants that had ≥ 2 mm bone loss. Interestingly, patients who were ≥ 70 years of age had significantly (P = .03) more bone loss in the mandible compared with the maxilla, while patients who were 60 to 69 years of age had significantly greater loss in the maxilla. These data reveal that for patients presenting to the dental school for a screening over a 2-year period, 1.98% had one or more dental implants. Furthermore, those patients with implants had a minimum amount of bone loss as measured from the top of the implant.

Synthesis and in vitro evaluation of bone-seeking superparamagnetic iron oxide nanoparticles as contrast agents for imaging bone metabolic activity.

PubMed

Panahifar, Arash; Mahmoudi, Morteza; Doschak, Michael R

2013-06-12

In this article, we report the synthesis and in vitro evaluation of a new class of nonionizing bone-targeting contrast agents based on bisphosphonate-conjugated superparamagnetic iron oxide nanoparticles (SPIONs), for use in imaging of bone turnover with magnetic resonance imaging (MRI). Similar to bone-targeting (99m)Technetium medronate, our novel contrast agent uses bisphosphonates to impart bone-seeking properties, but replaces the former radioisotope with nonionizing SPIONs which enables their subsequent detection using MRI. Our reported method is relatively simple, quick and cost-effective and results in BP-SPIONs with a final nanoparticle size of 17 nm under electron microscopy technique (i.e., TEM). In-vitro binding studies of our novel bone tracer have shown selective binding affinity (around 65%) for hydroxyapatite, the principal mineral of bone. Bone-targeting SPIONs offer the potential for use as nonionizing MRI contrast agents capable of imaging dynamic bone turnover, for use in the diagnosis and monitoring of metabolic bone diseases and related bone pathology.

Electron spin resonance (ESR) dose measurement in bone of Hiroshima A-bomb victim

PubMed Central

2018-01-01

Explosion of the bombs in Hiroshima and Nagasaki corresponds to the only historical moment when atomic bombs were used against civilians. This event triggered countless investigations into the effects and dosimetry of ionizing radiation. However, none of the investigations has used the victims’ bones as dosimeter. Here, we assess samples of bones obtained from fatal victims of the explosion by Electron Spin Resonance (ESR). In 1973, one of the authors of the present study (SM) traveled to Japan and conducted a preliminary experiment on the victims’ bone samples. The idea was to use the paramagnetism induced in bone after irradiation to measure the radiation dose. Technological advances involved in the construction of spectrometers, better knowledge of the paramagnetic center, and improvement in signal processing techniques have allowed us to resume the investigation. We obtained a reconstructed dose of 9.46 ± 3.4 Gy from the jawbone, which was compatible with the dose distribution in different locations as measured in non-biological materials such as wall bricks and roof tiles. PMID:29408890

Thermal and electron stimulated luminescence of natural bones, commercial hydroxyapatite and collagen.

PubMed

Roman-Lopez, J; Correcher, V; Garcia-Guinea, J; Rivera, T; Lozano, I B

2014-01-01

The luminescence (cathodoluminescence and thermoluminescence) properties of natural bones (Siberian mammoth and adult elephant), commercial hydroxyapatite and collagen were analyzed. Chemical analyses of the natural bones were determined using by Electron Probe Micro-Analysis (EMPA). Structural, molecular and thermal characteristics were determined by X-ray Diffraction (XRD), Raman spectroscopy and Differential Thermal and Thermogravimetric analysis (DTA-TG). Cathodoluminescence (CL) spectra of natural bones and collagen showed similar intense broad bands at 440 and 490 nm related to luminescence of the tetrahedral anion [Formula: see text] or structural defects. A weaker luminescence exhibited at 310 nm could be attributed to small amount of rare earth elements (REEs). Four luminescent bands at 378, 424, 468 and 576 nm were observed in the commercial hydroxyapatite (HAP). Both natural bones and collagen samples exhibited natural thermoluminescence (NTL) with well-defined glow curves whereas that the induced thermoluminescence (ITL) only appears in the samples of commercial hydroxyapatite and collagen. Additional explanations for the TL anomalous fading of apatite, as a crucial difficulty performing dosimetry and dating, are also considered. Copyright © 2013 Elsevier B.V. All rights reserved.

Carbon Fiber Biocompatibility for Implants

PubMed Central

Petersen, Richard

2016-01-01

Carbon fibers have multiple potential advantages in developing high-strength biomaterials with a density close to bone for better stress transfer and electrical properties that enhance tissue formation. As a breakthrough example in biomaterials, a 1.5 mm diameter bisphenol-epoxy/carbon-fiber-reinforced composite rod was compared for two weeks in a rat tibia model with a similar 1.5 mm diameter titanium-6-4 alloy screw manufactured to retain bone implants. Results showed that carbon-fiber-reinforced composite stimulated osseointegration inside the tibia bone marrow measured as percent bone area (PBA) to a great extent when compared to the titanium-6-4 alloy at statistically significant levels. PBA increased significantly with the carbon-fiber composite over the titanium-6-4 alloy for distances from the implant surfaces of 0.1 mm at 77.7% vs. 19.3% (p < 10−8) and 0.8 mm at 41.6% vs. 19.5% (p < 10−4), respectively. The review focuses on carbon fiber properties that increased PBA for enhanced implant osseointegration. Carbon fibers acting as polymer coated electrically conducting micro-biocircuits appear to provide a biocompatible semi-antioxidant property to remove damaging electron free radicals from the surrounding implant surface. Further, carbon fibers by removing excess electrons produced from the cellular mitochondrial electron transport chain during periods of hypoxia perhaps stimulate bone cell recruitment by free-radical chemotactic influences. In addition, well-studied bioorganic cell actin carbon fiber growth would appear to interface in close contact with the carbon-fiber-reinforced composite implant. Resulting subsequent actin carbon fiber/implant carbon fiber contacts then could help in discharging the electron biological overloads through electrochemical gradients to lower negative charges and lower concentration. PMID:26966555

Digital disruption ?syndromes.

PubMed

Sullivan, Clair; Staib, Andrew

2017-05-18

The digital transformation of hospitals in Australia is occurring rapidly in order to facilitate innovation and improve efficiency. Rapid transformation can cause temporary disruption of hospital workflows and staff as processes are adapted to the new digital workflows. The aim of this paper is to outline various types of digital disruption and some strategies for effective management. A large tertiary university hospital recently underwent a rapid, successful roll-out of an integrated electronic medical record (EMR). We observed this transformation and propose several digital disruption "syndromes" to assist with understanding and management during digital transformation: digital deceleration, digital transparency, digital hypervigilance, data discordance, digital churn and post-digital 'depression'. These 'syndromes' are defined and discussed in detail. Successful management of this temporary digital disruption is important to ensure a successful transition to a digital platform. What is known about this topic? Digital disruption is defined as the changes facilitated by digital technologies that occur at a pace and magnitude that disrupt established ways of value creation, social interactions, doing business and more generally our thinking. Increasing numbers of Australian hospitals are implementing digital solutions to replace traditional paper-based systems for patient care in order to create opportunities for improved care and efficiencies. Such large scale change has the potential to create transient disruption to workflows and staff. Managing this temporary disruption effectively is an important factor in the successful implementation of an EMR. What does this paper add? A large tertiary university hospital recently underwent a successful rapid roll-out of an integrated electronic medical record (EMR) to become Australia's largest digital hospital over a 3-week period. We observed and assisted with the management of several cultural, behavioural and operational forms of digital disruption which lead us to propose some digital disruption 'syndromes'. The definition and management of these 'syndromes' are discussed in detail. What are the implications for practitioners? Minimising the temporary effects of digital disruption in hospitals requires an understanding that these digital 'syndromes' are to be expected and actively managed during large-scale transformation.

Auger electron spectroscopy at high spatial resolution and nA primary beam currents

NASA Technical Reports Server (NTRS)

Todd, G.; Poppa, H.; Moorhead, D.; Bales, M.

1975-01-01

An experimental Auger microprobe system is described which incorporates a field-emission electron gun and total beam currents in the nanoampere range. The distinguishing characteristics of this system include a large multistation UHV specimen chamber, pulse counting and fully digital Auger signal-processing techniques, and digital referencing methods to eliminate the effects of beam instabilities. Some preliminary results obtained with this system are described, and it is concluded that field-emission electron sources can be used for high-resolution Auger electron spectroscopy with primary-beam spots of less than 100 nm and beam currents of the order of 1 nA.

Design and performance of the readout electronics chain of the Delphi Forward Ring Imaging Cherenkov Detector

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

Dam, P.; Nielsen, B.S.; Formenti, F.

1992-10-01

In this paper the Front End Readout electronics chain of the Forward Ring Imaging CHerenkov (FRICH) Detector used at the Delphi experiment of the Large Electron Positron (LEP) collider is presented. The system incorporates a wide band low noise preamplifier, mounted in the proximity of the MultiWire Proportional Chamber, an Amplifying-Discriminating-Multiple-xing FASTBUS unit for further signal amplification, discrimination and channel reduction and a LEP Time Digitizer FASTBUS unit for time digitization. The paper gives a general view of the detector and its electronics with particular emphasis on the novel characteristics and capabilities of the system.

Digital processing with single electrons for arbitrary waveform generation of current

NASA Astrophysics Data System (ADS)

Okazaki, Yuma; Nakamura, Shuji; Onomitsu, Koji; Kaneko, Nobu-Hisa

2018-03-01

We demonstrate arbitrary waveform generation of current using a GaAs-based single-electron pump. In our experiment, a digital processing algorithm known as delta-sigma modulation is incorporated into single-electron pumping to generate a density-modulated single-electron stream, by which we demonstrate the generation of arbitrary waveforms of current including sinusoidal, square, and triangular waves with a peak-to-peak amplitude of approximately 10 pA and an output bandwidth ranging from dc to close to 1 MHz. The developed current generator can be used as the precise and calculable current reference required for measurements of current noise in low-temperature experiments.

s48-e-013

NASA Image and Video Library

2012-11-08

S48-E-013 (15 Sept 1991) --- The Upper Atmosphere Research Satellite (UARS) in the payload bay of the earth- orbiting Discovery. UARS is scheduled for deploy on flight day three of the STS-48 mission. Data from UARS will enable scientists to study ozone depletion in the stratosphere, or upper atmosphere. This image was transmitted by the Electronic Still Camera (ESC), Development Test Objective (DTO) 648. The ESC is making its initial appearance on a Space Shuttle flight. Electronic still photography is a new technology that enables a camera to electronically capture and digitize an image with resolution approaching film quality. The digital image is stored on removable hard disks or small optical disks, and can be converted to a format suitable for downlink transmission or enhanced using image processing software. The Electronic Still Camera (ESC) was developed by the Man- Systems Division at the Johnson Space Center and is the first model in a planned evolutionary development leading to a family of high-resolution digital imaging devices. H. Don Yeates, JSC's Man-Systems Division, is program manager for the ESC. THIS IS A SECOND GENERATION PRINT MADE FROM AN ELECTRONICALLY PRODUCED NEGATIVE.

Coincidence electron/ion imaging with a fast frame camera

NASA Astrophysics Data System (ADS)

Li, Wen; Lee, Suk Kyoung; Lin, Yun Fei; Lingenfelter, Steven; Winney, Alexander; Fan, Lin

2015-05-01

A new time- and position- sensitive particle detection system based on a fast frame CMOS camera is developed for coincidence electron/ion imaging. The system is composed of three major components: a conventional microchannel plate (MCP)/phosphor screen electron/ion imager, a fast frame CMOS camera and a high-speed digitizer. The system collects the positional information of ions/electrons from a fast frame camera through real-time centroiding while the arrival times are obtained from the timing signal of MCPs processed by a high-speed digitizer. Multi-hit capability is achieved by correlating the intensity of electron/ion spots on each camera frame with the peak heights on the corresponding time-of-flight spectrum. Efficient computer algorithms are developed to process camera frames and digitizer traces in real-time at 1 kHz laser repetition rate. We demonstrate the capability of this system by detecting a momentum-matched co-fragments pair (methyl and iodine cations) produced from strong field dissociative double ionization of methyl iodide. We further show that a time resolution of 30 ps can be achieved when measuring electron TOF spectrum and this enables the new system to achieve a good energy resolution along the TOF axis.

Is Higher Education Ready to Switch to Digital Course Materials? The Cost of Textbooks Is Driving Electronic Solutions

ERIC Educational Resources Information Center

Nelson, Mark A.

2008-01-01

Each year one of the biggest debates in higher education seems to be: Is this the year that electronic textbooks take off? E-reader devices are getting better. The inventory of digital content is expanding. Business models are emerging to support the needs of students, faculty members, and publishers. People are getting more comfortable with new…

Young's modulus and SEM analysis of leg bones exposed to simulated microgravity by hind limb suspension (HLS)

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

Patel, Niravkumar D.; Mehta, Rahul; Ali, Nawab

2013-04-19

The aim of this study was to determine composition of the leg bone tissue of rats that were exposed to simulated microgravity by Hind-Limb Suspension (HLS) by tail for one week. The leg bones were cross sectioned, cleaned of soft tissues, dried and sputter coated, and then placed horizontally on the stage of a Scanning Electron Microscope (SEM) for analysis. Interaction of a 17.5 keV electron beam, incident from the vertical direction on the sample, generated images using two detectors. X-rays emitted from the sample during electron bombardment were measured with an Energy Dispersive Spectroscopy (EDS) feature of SEM usingmore » a liquid-nitrogen cooled Si(Li) detector with a resolution of 144 eV at 5.9 keV ({sub 25}Mn K{sub {alpha}} x-ray). K{sub {alpha}}- x-rays from carbon, oxygen, phosphorus and calcium formed the major peaks in the spectrum. Relative percentages of these elements were determined using a software that could also correct for ZAF factors namely Z(atomic number), A(X-ray absorption) and F(characteristic fluorescence). The x-rays from the control groups and from the experimental (HLS) groups were analyzed on well-defined parts (femur, tibia and knee) of the leg bone. The SEM analysis shows that there are definite changes in the hydroxyl or phosphate group of the main component of the bone structure, hydroxyapatite [Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}], due to hind limb suspension. In a separate experiment, entire leg bones (both from HLS and control rats) were subjected to mechanical stress by mean of a variable force. The stress vs. strain graph was fitted with linear and polynomial function, and the parameters reflecting the mechanical strength of the bone, under increasing stress, were calculated. From the slope of the linear part of the graph the Young's modulus for HLS bones were calculated and found to be 2.49 times smaller than those for control bones.« less

Murphy's law-if anything can go wrong, it will: Problems in phage electron microscopy.

PubMed

Ackermann, Hans-W; Tiekotter, Kenneth L

2012-04-01

The quality of bacteriophage electron microscopy appears to be on a downward course since the 1980s. This coincides with the introduction of digital electron microscopes and a general lowering of standards, possibly due to the disappearance of several world-class electron microscopists The most important problem seems to be poor contrast. Positive staining is frequently not recognized as an undesirable artifact. Phage parts, bacterial debris, and aberrant or damaged phage particles may be misdiagnosed as bacterial viruses. Digital electron microscopes often seem to be operated without magnification control because this is difficult and inconvenient. In summary, most phage electron microscopy problems may be attributed to human failure. Journals are a last-ditch defense and have a heavy responsibility in selecting competent reviewers and rejecting, or not, unsatisfactory articles.

In situ measurements of thunderstorm electrical properties

NASA Technical Reports Server (NTRS)

Marshall, T. C.

1982-01-01

An airplane sensor to measure the charge, size and two dimensional shape of precipitation particles and large cloud particles was developed. The basic design of the instrument includes: the transducers and analog electronics, the analog to digital conversion electronics and a microprocessor based system to run the electronics and load the digital data onto magnetic tape. Prototype instrumentation for the proposed lightning mapper satellite was tested by flying it in a U-2 aircraft over severe storms in Oklahoma. Flight data are compared to data from ground based instruments.

Distributed Interoperable Metadata Registry; How Do Physicists Use an E-Print Archive? Implications for Institutional E-Print Services; A Framework for Building Open Digital Libraries; Implementing Digital Sanborn Maps for Ohio: OhioLINK and OPLIN Collaborative Project.

ERIC Educational Resources Information Center

Blanchi, Christophe; Petrone, Jason; Pinfield, Stephen; Suleman, Hussein; Fox, Edward A.; Bauer, Charly; Roddy, Carol Lynn

2001-01-01

Includes four articles that discuss a distributed architecture for managing metadata that promotes interoperability between digital libraries; the use of electronic print (e-print) by physicists; the development of digital libraries; and a collaborative project between two library consortia in Ohio to provide digital versions of Sanborn Fire…

Linear Calibration of Radiographic Mineral Density Using Video-Digitizing Methods

NASA Technical Reports Server (NTRS)

Martin, R. Bruce; Papamichos, Thomas; Dannucci, Greg A.

1990-01-01

Radiographic images can provide quantitative as well as qualitative information if they are subjected to densitometric analysis. Using modem video-digitizing techniques, such densitometry can be readily accomplished using relatively inexpensive computer systems. However, such analyses are made more difficult by the fact that the density values read from the radiograph have a complex, nonlinear relationship to bone mineral content. This article derives the relationship between these variables from the nature of the intermediate physical processes, and presents a simple mathematical method for obtaining a linear calibration function using a step wedge or other standard.

Linear Calibration of Radiographic Mineral Density Using Video-Digitizing Methods

NASA Technical Reports Server (NTRS)

Martin, R. Bruce; Papamichos, Thomas; Dannucci, Greg A.

1990-01-01

Radiographic images can provide quantitative as well as qualitative information if they are subjected to densitometric analysis. Using modern video-digitizing techniques, such densitometry can be readily accomplished using relatively inexpensive computer systems. However, such analyses are made more difficult by the fact that the density values read from the radiograph have a complex, nonlinear relationship to bone mineral content. This article derives the relationship between these variables from the nature of the intermediate physical processes, and presents a simple mathematical method for obtaining a linear calibration function using a step wedge or other standard.

76 FR 78866 - Exemption to Prohibition on Circumvention of Copyright Protection Systems for Access Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-20

... initiated a rulemaking proceeding in accordance with provisions added by the Digital Millennium Copyright... available in digital copies. Proponent: The Open Book Alliance. 2. Literary works, distributed electronically, that: (1) Contain digital rights management and/or other access controls which either prevent the...

36 CFR 1235.48 - What documentation must agencies transfer with electronic records?

Code of Federal Regulations, 2010 CFR

2010-07-01

... digital geospatial data files can include metadata that conforms to the Federal Geographic Data Committee's Content Standards for Digital Geospatial Metadata, as specified in Executive Order 12906 of April... number (301) 837-2903 for digital photographs and metadata, or the National Archives and Records...

36 CFR 1235.48 - What documentation must agencies transfer with electronic records?

Code of Federal Regulations, 2012 CFR

2012-07-01

... digital geospatial data files can include metadata that conforms to the Federal Geographic Data Committee's Content Standards for Digital Geospatial Metadata, as specified in Executive Order 12906 of April... number (301) 837-2903 for digital photographs and metadata, or the National Archives and Records...

36 CFR § 1235.48 - What documentation must agencies transfer with electronic records?

Code of Federal Regulations, 2013 CFR

2013-07-01

... digital geospatial data files can include metadata that conforms to the Federal Geographic Data Committee's Content Standards for Digital Geospatial Metadata, as specified in Executive Order 12906 of April... number (301) 837-2903 for digital photographs and metadata, or the National Archives and Records...

36 CFR 1235.48 - What documentation must agencies transfer with electronic records?

Code of Federal Regulations, 2011 CFR

2011-07-01

... digital geospatial data files can include metadata that conforms to the Federal Geographic Data Committee's Content Standards for Digital Geospatial Metadata, as specified in Executive Order 12906 of April... number (301) 837-2903 for digital photographs and metadata, or the National Archives and Records...

36 CFR 1235.48 - What documentation must agencies transfer with electronic records?

Code of Federal Regulations, 2014 CFR

2014-07-01

... digital geospatial data files can include metadata that conforms to the Federal Geographic Data Committee's Content Standards for Digital Geospatial Metadata, as specified in Executive Order 12906 of April... number (301) 837-2903 for digital photographs and metadata, or the National Archives and Records...

75 FR 34782 - Exelon Generation Company, LLC, Braidwood Station, Independent Spent Fuel Installation Order...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-18

..., to request (1) a digital ID certificate, which allows the participant (or its counsel or... NRC- issued digital ID certificate). Based upon this information, the Secretary will establish an... electronic docket. Information about applying for a digital ID certificate is available on NRC's public Web...

Fundamentals of Digital Logic.

ERIC Educational Resources Information Center

Noell, Monica L.

This course is designed to prepare electronics personnel for further training in digital techniques, presenting need to know information that is basic to any maintenance course on digital equipment. It consists of seven study units: (1) binary arithmetic; (2) boolean algebra; (3) logic gates; (4) logic flip-flops; (5) nonlogic circuits; (6)…

[Morphofunctional properties of the peripheral blood and bone marrow cells of rats following a flight on board the Kosmos-936 biosatellite].

PubMed

Kozinets, G I; Korol'kov, V I; Britvan, I I; Bykova, I A; Spitsyna, N E

1983-01-01

Morphofunctional properties of peripheral blood cells of Cosmos-936 rats were examined, using morphological, interferometric and electron microscopic techniques. As follows from the morphological data, immediately after recovery the weightless rats showed symptoms of a stress reaction which disappeared by R+3. The centrifuged rats exhibited less expressed symptoms of this sort. The percentage of bone marrow cell distribution was shifted towards enhanced myelopoiesis and diminished erythropoiesis. By the end of the readaptation period the ratio of bone marrow cell composition returned to normal. Interferometric and electron microscopic examinations did not reveal any irreversible changes in the structure and function of cells that may be caused by zero-g.

Additively manufactured sub-periosteal jaw implants.

PubMed

Mommaerts, M Y

2017-07-01

Severe bone atrophy jeopardizes the success of endosseous implants. This technical note aims to present the innovative concept of additively manufactured sub-periosteal jaw implants (AMSJIs). Digital datasets of the patient's jaws and wax trial in occlusion are used to segment the bone and dental arches, for the design of a sub-periosteal frame and abutments in the optimal location related to the dental arch and for the design of the suprastructure. The implants and suprastructure are three-dimensionally (3D) printed in titanium alloy. The provisional denture is 3D-printed in polymer. AMSJIs offer an alternative approach for patients with extreme jaw bone atrophy. This report refers to the use of this technique for full maxillary rehabilitation, but partial defects in either jaw and extended post-resection defects may also be approached using the same technique. This customized, prosthesis-driven reverse-engineering approach avoids bone grafting and provides immediate functional restoration with one surgical session. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

INTERFRAGMENTARY SURFACE AREA AS AN INDEX OF COMMINUTION SEVERITY IN CORTICAL BONE IMPACT

PubMed Central

Beardsley, Christina L.; Anderson, Donald D.; Marsh, J. Lawrence; Brown, Thomas D.

2008-01-01

Summary A monotonic relationship is expected between energy absorption and fracture surface area generation for brittle solids, based on fracture mechanics principles. It was hypothesized that this relationship is demonstrable in bone, to the point that on a continuous scale, comminuted fractures created with specific levels of energy delivery could be discriminated from one another. Using bovine cortical bone segments in conjunction with digital image analysis of CT fracture data, the surface area freed by controlled impact fracture events was measured. The results demonstrated a statistically significant (p<0.0001) difference in measured de novo surface area between three specimen groups, over a range of input energies from 0.423 to 0.702 J/g. Local material properties were also incorporated into these measurements via CT Hounsfield intensities. This study confirms that comminution severity of bone fractures can indeed be measured on a continuous scale, based on energy absorption. This lays a foundation for similar assessments in human injuries. PMID:15885492

Bone bonding strength of diamond-structured porous titanium-alloy implants manufactured using the electron beam-melting technique.

PubMed

Hara, Daisuke; Nakashima, Yasuharu; Sato, Taishi; Hirata, Masanobu; Kanazawa, Masayuki; Kohno, Yusuke; Yoshimoto, Kensei; Yoshihara, Yusuke; Nakamura, Akihiro; Nakao, Yumiko; Iwamoto, Yukihide

2016-02-01

The present study examined the bone bonding strength of diamond-structured porous titanium-alloy (Porous-Ti-alloy) manufactured using the electron beam-melting technique in comparison with fiber mesh-coated or rough-surfaced implants. Cylindrical implants with four different pore sizes (500, 640, 800, and 1000μm) of Porous-Ti-alloy, titanium fiber mesh (FM), and surfaces roughened by titanium arc spray (Ti-spray) were implanted into the distal femur of rabbits. Bone bonding strength and histological bone ingrowth were evaluated at 4 and 12weeks after implantation. The bone bonding strength of Porous-Ti-alloy implants (640μm pore size) increased over time from 541.4N at 4weeks to 704.6N at 12weeks and was comparable to that of FM and Ti-spray implants at both weeks. No breakage of the porous structure after mechanical testing was found with Porous-Ti-alloy implants. Histological bone ingrowth that increased with implantation time occurred along the inner structure of Porous-Ti-alloy implants. There was no difference in bone ingrowth in Porous-Ti-alloy implants with pore sizes among 500, 640, and 800μm; however, less bone ingrowth was observed with the 1000μm pore size. These results indicated Porous-Ti-alloy implants with pore size under 800μm provided biologically active and mechanically stable surface for implant fixation to bone, and had potential advantages for weight bearing orthopedic implants such as acetabular cups. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of a novel load-bearing trabecular Nitinol scaffold on rabbit radius bone regeneration

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

Gotman, Irena, E-mail: gotman@technion.ac.il; Gutmanas, Elazar Y., E-mail: gutmanas@technion.ac.il; National Research Tomsk Polytechnic University, Tomsk, 634050

The research aim was to evaluate the bone regeneration capability of novel load-bearing NiTi alloy (Nitinol) scaffolds in a critical-size defect (CSD) model. High strength “trabecular Nitinol” scaffolds were prepared by PIRAC (Powder Immersion Reaction Assisted Coating) annealing of the highly porous Ni foam in Ti powder at 900°C. This was followed by PIRAC nitriding to mitigate the release of potentially toxic Ni ions. Scaffolds phase composition and microstructure were characterized by X-ray diffraction and scanning electron microscopy (SEM/EDS), and their mechanical properties were tested in compression. New Zealand white rabbits received bone defect in right radius and were dividedmore » in four groups randomly. In the control group, nothing was placed in the defect. In other groups, NiTi scaffolds were implanted in the defect: (i) as produced, (ii) loaded with bone marrow aspirate (BMA), and (iii) biomimetically CaP-coated. The animals were sacrificed after 12 weeks. The forelimbs with scaffolds were resected, fixed, sectioned and examined in SEM. New bone formation inside the scaffold was studied by EDS analysis and by the processing of backscattered electron images. Bone ingrowth into the scaffold was observed in all implant groups, mostly next to the ulna. New bone formation was strongly enhanced by BMA loading and biomimeatic CaP coating, the bone penetrating as much as 1–1.5 mm into the scaffold. The results of this preliminary study demonstrate that the newly developed high strength trabecular Nitinol scaffolds can be successfully used for bone regeneration in critical size defects.« less

Characterizing the composition of bone formed during fracture healing using scanning electron microscopy techniques.

PubMed

Perdikouri, Christina; Tägil, Magnus; Isaksson, Hanna

2015-01-01

About 5-10% of all bone fractures suffer from delayed healing, which may lead to non-union. Bone morphogenetic proteins (BMPs) can be used to induce differentiation of osteoblasts and enhance the formation of the bony callus, and bisphosphonates help to retain the newly formed callus. The aim of this study was to investigate if scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) can identify differences in the mineral composition of the newly formed bone compared to cortical bone from a non-fractured control. Moreover, we investigate whether the use of BMPs and bisphosphonates-alone or combined-may have an effect on bone mineralization and composition. Twelve male Sprague-Dawley rats at 9 weeks of age were randomly divided into four groups and treated with (A) saline, (B) BMP-7, (C) bisphosphonates (Zoledronate), and (D) BMP-7 + Zoledronate. The rats were sacrificed after 6 weeks. All samples were imaged using SEM and chemically analyzed with EDS to quantify the amount of C, N, Ca, P, O, Na, and Mg. The Ca/P ratio was the primary outcome. In the fractured samples, two areas of interest were chosen for chemical analysis with EDS: the callus and the cortical bone. In the non-fractured samples, only the cortex was analyzed. Our results showed that the element composition varied to a small extent between the callus and the cortical bone in the fractured bones. However, the Ca/P ratio did not differ significantly, suggesting that the mineralization at all sites is similar 6 weeks post-fracture in this rat model.

Whole slide images and digital media in pathology education, testing, and practice: the Oklahoma experience.

PubMed

Fung, Kar-Ming; Hassell, Lewis A; Talbert, Michael L; Wiechmann, Allan F; Chaser, Brad E; Ramey, Joel

2012-01-01

Examination of glass slides is of paramount importance in pathology training. Until the introduction of digitized whole slide images that could be accessed through computer networks, the sharing of pathology slides was a major logistic issue in pathology education and practice. With the help of whole slide images, our department has developed several online pathology education websites. Based on a modular architecture, this program provides online access to whole slide images, still images, case studies, quizzes and didactic text at different levels. Together with traditional lectures and hands-on experiences, it forms the back bone of our histology and pathology education system for residents and medical students. The use of digitized whole slide images has a.lso greatly improved the communication between clinicians and pathologist in our institute.

Digital circuits for computer applications: A compilation

NASA Technical Reports Server (NTRS)

1972-01-01

The innovations in this updated series of compilations dealing with electronic technology represent a carefully selected collection of digital circuits which have direct application in computer oriented systems. In general, the circuits have been selected as representative items of each section and have been included on their merits of having universal applications in digital computers and digital data processing systems. As such, they should have wide appeal to the professional engineer and scientist who encounter the fundamentals of digital techniques in their daily activities. The circuits are grouped as digital logic circuits, analog to digital converters, and counters and shift registers.

Barriers and facilitators to adoption of soft copy interpretation from the user perspective: Lessons learned from filmless radiology for slideless pathology

PubMed Central

Patterson, Emily S.; Rayo, Mike; Gill, Carolina; Gurcan, Metin N.

2011-01-01

Background: Adoption of digital images for pathological specimens has been slower than adoption of digital images in radiology, despite a number of anticipated advantages for digital images in pathology. In this paper, we explore the factors that might explain this slower rate of adoption. Materials and Method: Semi-structured interviews on barriers and facilitators to the adoption of digital images were conducted with two radiologists, three pathologists, and one pathologist's assistant. Results: Barriers and facilitators to adoption of digital images were reported in the areas of performance, workflow-efficiency, infrastructure, integration with other software, and exposure to digital images. The primary difference between the settings was that performance with the use of digital images as compared to the traditional method was perceived to be higher in radiology and lower in pathology. Additionally, exposure to digital images was higher in radiology than pathology, with some radiologists exclusively having been trained and/or practicing with digital images. The integration of digital images both improved and reduced efficiency in routine and non-routine workflow patterns in both settings, and was variable across the different organizations. A comparison of these findings with prior research on adoption of other health information technologies suggests that the barriers to adoption of digital images in pathology are relatively tractable. Conclusions: Improving performance using digital images in pathology would likely accelerate adoption of innovative technologies that are facilitated by the use of digital images, such as electronic imaging databases, electronic health records, double reading for challenging cases, and computer-aided diagnostic systems. PMID:21383925

In vivo performance of selective electron beam-melted Ti-6Al-4V structures.

PubMed

Ponader, Sabine; von Wilmowsky, Cornelius; Widenmayer, Martin; Lutz, Rainer; Heinl, Peter; Körner, Carolin; Singer, Robert F; Nkenke, Emeka; Neukam, Friedrich W; Schlegel, Karl A

2010-01-01

Highly porous titanium structures are widely used for maxillofacial and orthopedic surgery because of their excellent mechanical properties similar to those of human bone and their facilitation of bone ingrowth. In contrast to common methods, the generation of porous titaniumproducts by selective electron beam melting (SEBM), an additive manufacturing technology, overcomes difficulties concerning the extreme chemical affinity of liquid titanium to atmospheric gases which consequently leads to strongly reduced ductility of the metal. The purpose of this study was to assess the suitability of a smooth compact and a porous Ti-6Al-4V structure directly produced by the SEBM process as scaffolds for bone formation. SEBM-processed titanium implants were placed into defects in the frontal skull of 15 domestic pigs. To evaluate the direct contact between bone and implant surfaces and to assess the ingrowth of osseous tissue into the porous structure, microradiographs and histomorphometric analyses were performed 14, 30, and 60 days after surgery. Bone ingrowth increased significantly during the period of this study. After 14 days the most outer regions of the implants were already filled with newly formed bone tissue (around 14%). After 30 days the bone volume inside the implants reached almost 30% and after 60 days abundant bone formation inside the implants attained 46%. During the study only scarce bone-implant contact was found around all implants, which did not exceed 9% around compact specimens and 6% around porous specimens after 60 days. This work demonstrates that highly porous titanium implants with excellent interconnectivity manufactured using the SEBM method are suitable scaffolds for bone ingrowth. This technique is a good candidate for orthopedic and maxillofacial applications.

Biologically inspired rosette nanotubes and nanocrystalline hydroxyapatite hydrogel nanocomposites as improved bone substitutes

NASA Astrophysics Data System (ADS)

Zhang, Lijie; Rodriguez, Jose; Raez, Jose; Myles, Andrew J.; Fenniri, Hicham; Webster, Thomas J.

2009-04-01

Today, bone diseases such as bone fractures, osteoporosis and bone cancer represent a common and significant public health problem. The design of biomimetic bone tissue engineering materials that could restore and improve damaged bone tissues provides exciting opportunities to solve the numerous problems associated with traditional orthopedic implants. Therefore, the objective of this in vitro study was to create a biomimetic orthopedic hydrogel nanocomposite based on the self-assembly properties of helical rosette nanotubes (HRNs), the osteoconductive properties of nanocrystalline hydroxyapatite (HA), and the biocompatible properties of hydrogels (specifically, poly(2-hydroxyethyl methacrylate), pHEMA). HRNs are self-assembled nanomaterials that are formed from synthetic DNA base analogs in water to mimic the helical nanostructure of collagen in bone. In this study, different geometries of nanocrystalline HA were controlled by either hydrothermal or sintering methods. 2 and 10 wt% nanocrystalline HA particles were well dispersed into HRN hydrogels using ultrasonication. The nanocrystalline HA and nanocrystalline HA/HRN hydrogels were characterized by x-ray diffraction, transmission electron microscopy, and scanning electron microscopy. Mechanical testing studies revealed that the well dispersed nanocrystalline HA in HRN hydrogels possessed improved mechanical properties compared to hydrogel controls. In addition, the results of this study provided the first evidence that the combination of either 2 or 10 wt% nanocrystalline HA and 0.01 mg ml-1 HRNs in hydrogels greatly increased osteoblast (bone-forming cell) adhesion up to 236% compared to hydrogel controls. Moreover, this study showed that HRNs stimulated HA nucleation and mineralization along their main axis in a way that is very reminiscent of the HA/collagen assembly pattern in natural bone. In summary, the presently observed excellent properties of the biomimetic nanocrystalline HA/HRN hydrogel composites make them promising candidates for further study for bone tissue engineering applications.

Subjective and quantitative scintigraphic assessment of the equine foot and its relationship with foot pain.

PubMed

Dyson, S J

2002-03-01

It was hypothesised that in solar bone images of the front feet of clinically normal horses, or horses with lameness unrelated to the front feet, there would be less than a 10% difference in the ratio of uptake of radiopharmaceutical in either the region of the navicular bone, or the region of insertion of the deep digital flexor tendon (DDFT), compared to the peripheral regions of the distal phalanx. Nuclear scintigraphic examination of the front feet of 15 Grand Prix show jumping horses, all of which were free from detectable lameness, was performed using dorsal, lateral and solar images. The results were compared with the examinations of 53 horses with primary foot pain, 21 with foot pain accompanying another more severe cause of lameness and 49 with lameness or poor performance unrelated to foot pain. None of the horses with foot pain had radiological changes compatible with navicular disease. All the images were evaluated subjectively. The solar views were assessed quantitatively using regions of interest around the navicular bone, the region of insertion of the deep digital flexor tendon and the toe, medial and lateral aspects of the distal phalanx. In 97% of the feet of normal showjumpers, there was <10% variance of uptake of the radiopharmaceutical in the navicular bone, the region of insertion of the DDFT and the peripheral regions of the distal phalanx. There was a significant difference in uptake of radiopharmaceutical in the region of the navicular bone in horses with foot pain compared to normal horses. There was a large incidence of false positive results related to the region of insertion of the DDFT. Lateral pool phase images appeared more sensitive in identifying potentially important DDFT lesions. There was a good correlation between a positive response to intra-articular analgesia of the distal interphalangeal joint and intrathecal analgesia of the navicular bursa and increased uptake of radiopharmaceutical in the region of the navicular bone in the horses with primary foot pain. It is concluded that quantitative scintigraphic assessment of bone phase images of the foot, in combination with local analgesic techniques, can be helpful in the identification of the potential source of pain causing lameness related to the foot, but false positive results can occur, especially in horses with low heel conformation.

Determination of Small Animal Long Bone Properties Using Densitometry

NASA Technical Reports Server (NTRS)

Breit, Gregory A.; Goldberg, BethAnn K.; Whalen, Robert T.; Hargens, Alan R. (Technical Monitor)

1996-01-01

Assessment of bone structural property changes due to loading regimens or pharmacological treatment typically requires destructive mechanical testing and sectioning. Our group has accurately and non-destructively estimated three dimensional cross-sectional areal properties (principal moments of inertia, Imax and Imin, and principal angle, Theta) of human cadaver long bones from pixel-by-pixel analysis of three non-coplanar densitometry scans. Because the scanner beam width is on the order of typical small animal diapbyseal diameters, applying this technique to high-resolution scans of rat long bones necessitates additional processing to minimize errors induced by beam smearing, such as dependence on sample orientation and overestimation of Imax and Imin. We hypothesized that these errors are correctable by digital image processing of the raw scan data. In all cases, four scans, using only the low energy data (Hologic QDR-1000W, small animal mode), are averaged to increase image signal-to-noise ratio. Raw scans are additionally processed by interpolation, deconvolution by a filter derived from scanner beam characteristics, and masking using a variable threshold based on image dynamic range. To assess accuracy, we scanned an aluminum step phantom at 12 orientations over a range of 180 deg about the longitudinal axis, in 15 deg increments. The phantom dimensions (2.5, 3.1, 3.8 mm x 4.4 mm; Imin/Imax: 0.33-0.74) were comparable to the dimensions of a rat femur which was also scanned. Cross-sectional properties were determined at 0.25 mm increments along the length of the phantom and femur. The table shows average error (+/- SD) from theory of Imax, Imin, and Theta) over the 12 orientations, calculated from raw and fully processed phantom images, as well as standard deviations about the mean for the femur scans. Processing of phantom scans increased agreement with theory, indicating improved accuracy. Smaller standard deviations with processing indicate increased precision and repeatability. Standard deviations for the femur are consistent with those of the phantom. We conclude that in conjunction with digital image enhancement, densitometry scans are suitable for non-destructive determination of areal properties of small animal bones of comparable size to our phantom, allowing prediction of Imax and Imin within 2.5% and Theta within a fraction of a degree. This method represents a considerable extension of current methods of analyzing bone tissue distribution in small animal bones.

Fully digital data processing during cardiovascular implantable electronic device follow-up in a high-volume tertiary center.

PubMed

Staudacher, Ingo; Nalpathamkalam, Asha Roy; Uhlmann, Lorenz; Illg, Claudius; Seehausen, Sebastian; Akhavanpoor, Mohammadreza; Buchauer, Anke; Geis, Nicolas; Lugenbiel, Patrick; Schweizer, Patrick A; Xynogalos, Panagiotis; Zylla, Maura M; Scholz, Eberhard; Zitron, Edgar; Katus, Hugo A; Thomas, Dierk

2017-10-11

Increasing numbers of patients with cardiovascular implantable electronic devices (CIEDs) and limited follow-up capacities highlight unmet challenges in clinical electrophysiology. Integrated software (MediConnect ® ) enabling fully digital processing of device interrogation data has been commercially developed to facilitate follow-up visits. We sought to assess feasibility of fully digital data processing (FDDP) during ambulatory device follow-up in a high-volume tertiary hospital to provide guidance for future users of FDDP software. A total of 391 patients (mean age, 70 years) presenting to the outpatient department for routine device follow-up were analyzed (pacemaker, 44%; implantable cardioverter defibrillator, 39%; cardiac resynchronization therapy device, 16%). Quality of data transfer and follow-up duration were compared between digital (n = 265) and manual processing of device data (n = 126). Digital data import was successful, complete and correct in 82% of cases when early software versions were used. When using the most recent software version the rate of successful digital data import increased to 100%. Software-based import of interrogation data was complete and without failure in 97% of cases. The mean duration of a follow-up visit did not differ between the two groups (digital 18.7 min vs. manual data transfer 18.2 min). FDDP software was successfully implemented into the ambulatory follow-up of patients with implanted pacemakers and defibrillators. Digital data import into electronic patient management software was feasible and supported the physician's workflow. The total duration of follow-up visits comprising technical device interrogation and clinical actions was not affected in the present tertiary center outpatient cohort.

Flight evaluation of a digital electronic engine control system in an F-15 airplane

NASA Technical Reports Server (NTRS)

Myers, L. P.; Mackall, K. G.; Burcham, F. W., Jr.; Walter, W. A.

1982-01-01

Benefits provided by a full-authority digital engine control are related to improvements in engine efficiency, performance, and operations. An additional benefit is the capability of detecting and accommodating failures in real time and providing engine-health diagnostics. The digital electronic engine control (DEEC), is a full-authority digital engine control developed for the F100-PW-100 turbofan engine. The DEEC has been flight tested on an F-15 aircraft. The flight tests had the objective to evaluate the DEEC hardware and software over the F-15 flight envelope. A description is presented of the results of the flight tests, which consisted of nonaugmented and augmented throttle transients, airstarts, and backup control operations. The aircraft, engine, DEEC system, and data acquisition and reduction system are discussed.

Mechanical behavior of osteoporotic bone at sub-lamellar length scales

NASA Astrophysics Data System (ADS)

Jimenez-Palomar, Ines; Shipov, Anna; Shahar, Ron; Barber, Asa

2015-02-01

Osteoporosis is a disease known to promote bone fragility but the effect on the mechanical properties of bone material, which is independent of geometric effects, is particularly unclear. To address this problem, micro-beams of osteoporotic bone were prepared using focused ion beam (FIB) microscopy and mechanically tested in compression using an atomic force microscope (AFM) while observing using in situ electron microscopy. This experimental approach was shown to be effective at measuring the subtle changes in the mechanical properties of bone material required to evaluate the effects of osteoporosis. Osteoporotic bone material was found to have lower elastic modulus and increased strain to failure when compared to healthy bone material, while the strength of osteoporotic and healthy bone was similar. A mechanism is suggested based on these results and previous literature that indicates degradation of the organic material in osteoporosis bone is responsible for resultant mechanical properties.

Effects of lead and cadmium exposure from electronic waste on child physical growth.

PubMed

Yang, Hui; Huo, Xia; Yekeen, Taofeek Akangbe; Zheng, Qiujian; Zheng, Minghao; Xu, Xijin

2013-07-01

Many studies indicate that lead (Pb) and cadmium (Cd) exposure may alter bone development through both direct and indirect mechanisms, increasing the risk of osteoporosis later in life. The aim of this study was to investigate the association between Pb and Cd exposure, physical growth, and bone and calcium metabolism in children of an electronic waste (e-waste) processing area. We recruited 246 children (3-8 years) in a kindergarten located in Guiyu, China. Blood lead levels (BLLs) and blood cadmium levels (BCLs) of recruited children were measured as biomarkers for exposure. Serum calcium, osteocalcin, bone alkaline phosphatase, and urinary deoxypyridinoline were used as biomarkers for bone and calcium metabolism. Physical indexes such as height, weight, and head and chest circumference were also measured. The mean values of BLLs and BCLs obtained were 7.30 μg/dL and 0.69 μg/L, respectively. The average of BCLs increased with age. In multiple linear regression analysis, BLLs were negatively correlated with both height and weight, and positively correlated with bone resorption biomarkers. Neither bone nor calcium metabolic biomarkers showed significant correlation with cadmium. Childhood lead exposure affected both physical development and increased bone resorption of children in Guiyu. Primitive e-waste recycling may threaten the health of children with elevated BLL which may eventually cause adult osteoporosis.

Bone Response to Surface-Modified Titanium Implants: Studies on the Early Tissue Response to Implants with Different Surface Characteristics

PubMed Central

Larsson Wexell, C.; Thomsen, P.; Aronsson, B.-O.; Tengvall, P.; Rodahl, M.; Lausmaa, J.; Kasemo, B.; Ericson, L. E.

2013-01-01

In a series of experimental studies, the bone formation around systematically modified titanium implants is analyzed. In the present study, three different surface modifications were prepared and evaluated. Glow-discharge cleaning and oxidizing resulted in a highly stoichiometric TiO2 surface, while a glow-discharge treatment in nitrogen gas resulted in implants with essentially a surface of titanium nitride, covered with a very thin titanium oxide. Finally, hydrogen peroxide treatment of implants resulted in an almost stoichiometric TiO2, rich in hydroxyl groups on the surface. Machined commercially pure titanium implants served as controls. Scanning Auger Electron Spectroscopy, Scanning Electron Microscopy, and Atomic Force Microscopy revealed no significant differences in oxide thickness or surface roughness parameters, but differences in the surface chemical composition and apparent topography were observed. After surface preparation, the implants were inserted in cortical bone of rabbits and evaluated after 1, 3, and 6 weeks. Light microscopic evaluation of the tissue response showed that all implants were in contact with bone and had a large proportion of newly formed bone within the threads after 6 weeks. There were no morphological differences between the four groups. Our study shows that a high degree of bone contact and bone formation can be achieved with titanium implants of different surface composition and topography. PMID:24174936

Finite element analysis of steel fiber-reinforced concrete (SFRC): validation of experimental tensile capacity of dog-bone specimens

NASA Astrophysics Data System (ADS)

Islam, Md. Mashfiqul; Chowdhury, Md. Arman; Sayeed, Md. Abu; Hossain, Elsha Al; Ahmed, Sheikh Saleh; Siddique, Ashfia

2014-09-01

Finite element analyses are conducted to model the tensile capacity of steel fiber-reinforced concrete (SFRC). For this purpose dog-bone specimens are casted and tested under direct and uniaxial tension. Two types of aggregates (brick and stone) are used to cast the SFRC and plain concrete. The fiber volume ratio is maintained 1.5 %. Total 8 numbers of dog-bone specimens are made and tested in a 1000-kN capacity digital universal testing machine (UTM). The strain data are gathered employing digital image correlation technique from high-definition images and high-speed video clips. Then, the strain data are synthesized with the load data obtained from the load cell of the UTM. The tensile capacity enhancement is found 182-253 % compared to control specimen to brick SFRC and in case of stone SFRC the enhancement is 157-268 %. Fibers are found to enhance the tensile capacity as well as ductile properties of concrete that ensures to prevent sudden brittle failure. The dog-bone specimens are modeled in the ANSYS 10.0 finite element platform and analyzed to model the tensile capacity of brick and stone SFRC. The SOLID65 element is used to model the SFRC as well as plain concretes by optimizing the Poisson's ratio, modulus of elasticity, tensile strength and stress-strain relationships and also failure pattern as well as failure locations. This research provides information of the tensile capacity enhancement of SFRC made of both brick and stone which will be helpful for the construction industry of Bangladesh to introduce this engineering material in earthquake design. Last of all, the finite element outputs are found to hold good agreement with the experimental tensile capacity which validates the FE modeling.

Performance of a Deep-Learning Neural Network Model in Assessing Skeletal Maturity on Pediatric Hand Radiographs.

PubMed

Larson, David B; Chen, Matthew C; Lungren, Matthew P; Halabi, Safwan S; Stence, Nicholas V; Langlotz, Curtis P

2018-04-01

Purpose To compare the performance of a deep-learning bone age assessment model based on hand radiographs with that of expert radiologists and that of existing automated models. Materials and Methods The institutional review board approved the study. A total of 14 036 clinical hand radiographs and corresponding reports were obtained from two children's hospitals to train and validate the model. For the first test set, composed of 200 examinations, the mean of bone age estimates from the clinical report and three additional human reviewers was used as the reference standard. Overall model performance was assessed by comparing the root mean square (RMS) and mean absolute difference (MAD) between the model estimates and the reference standard bone ages. Ninety-five percent limits of agreement were calculated in a pairwise fashion for all reviewers and the model. The RMS of a second test set composed of 913 examinations from the publicly available Digital Hand Atlas was compared with published reports of an existing automated model. Results The mean difference between bone age estimates of the model and of the reviewers was 0 years, with a mean RMS and MAD of 0.63 and 0.50 years, respectively. The estimates of the model, the clinical report, and the three reviewers were within the 95% limits of agreement. RMS for the Digital Hand Atlas data set was 0.73 years, compared with 0.61 years of a previously reported model. Conclusion A deep-learning convolutional neural network model can estimate skeletal maturity with accuracy similar to that of an expert radiologist and to that of existing automated models. © RSNA, 2017 An earlier incorrect version of this article appeared online. This article was corrected on January 19, 2018.

Impaired rib bone mass and quality in end-stage cystic fibrosis patients.

PubMed

Mailhot, Geneviève; Dion, Natalie; Farlay, Delphine; Rizzo, Sébastien; Bureau, Nathalie J; Jomphe, Valérie; Sankhe, Safiétou; Boivin, Georges; Lands, Larry C; Ferraro, Pasquale; Ste-Marie, Louis-Georges

2017-05-01

Advancements in research and clinical care have considerably extended the life expectancy of cystic fibrosis (CF) patients. However, with this extended survival come comorbidities. One of the leading co-morbidities is CF-related bone disease (CFBD), which progresses with disease severity and places patients at high risk for fractures, particularly of the ribs and vertebrae. Evidence that CF patients with vertebral fractures had higher bone mineral density (BMD) than the nonfracture group led us to postulate that bone quality is impaired in these patients. We therefore examined rib specimens resected at the time of lung transplant in CF patients to measure parameters of bone quantity and quality. In this exploratory study, we analysed 19 end-stage CF and 13 control rib specimens resected from otherwise healthy lung donors. BMD, bone microarchitecture, static parameters of bone formation and resorption and microcrack density of rib specimens were quantified by imaging, histomorphometric and histological methods. Variables reflecting the mineralization of ribs were assessed by digitized microradiography. The degree of bone mineralization (g/cm 3 ) and the heterogeneity index of the mineralization (g/cm 3 ) were calculated for trabecular and cortical bone. Compared to controls, CF ribs exhibited lower areal and trabecular volumetric BMD, decreased trabecular thickness and osteoid parameters, and increased microcrack density, that was particularly pronounced in specimens from patients with CF-related diabetes. Static parameters of bone resorption were similar in both groups. Degree of mineralization of total bone, but not heterogeneity index, was increased in CF specimens. The combination of reduced bone mass, altered microarchitecture, imbalanced bone remodeling (maintained bone resorption but decreased formation), increased microdamage and a small increase of the degree of mineralization, may lead to decreased bone strength, which, when coupled with chronic coughing and chest physical therapy, may provide an explanation for the increased incidence of rib fractures previously reported in this population. Copyright © 2017 Elsevier Inc. All rights reserved.

SU-E-J-219: A Dixon Based Pseudo-CT Generation Method for MR-Only Radiotherapy Treatment Planning of the Pelvis and Head and Neck

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

Maspero, M.; Meijer, G.J.; Lagendijk, J.J.W.

2015-06-15

Purpose: To develop an image processing method for MRI-based generation of electron density maps, known as pseudo-CT (pCT), without usage of model- or atlas-based segmentation, and to evaluate the method in the pelvic and head-neck region against CT. Methods: CT and MRI scans were obtained from the pelvic region of four patients in supine position using a flat table top only for CT. Stratified CT maps were generated by classifying each voxel based on HU ranges into one of four classes: air, adipose tissue, soft tissue or bone.A hierarchical region-selective algorithm, based on automatic thresholding and clustering, was used tomore » classify tissues from MR Dixon reconstructed fat, In-Phase (IP) and Opposed-Phase (OP) images. First, a body mask was obtained by thresholding the IP image. Subsequently, an automatic threshold on the Dixon fat image differentiated soft and adipose tissue. K-means clustering on IP and OP images resulted in a mask that, via a connected neighborhood analysis, allowing the user to select the components corresponding to bone structures.The pCT was estimated through assignment of bulk HU to the tissue classes. Bone-only Digital Reconstructed Radiographs (DRR) were generated as well. The pCT images were rigidly registered to the stratified CT to allow a volumetric and voxelwise comparison. Moreover, pCTs were also calculated within the head-neck region in two volunteers using the same pipeline. Results: The volumetric comparison resulted in differences <1% for each tissue class. A voxelwise comparison showed a good classification, ranging from 64% to 98%. The primary misclassified classes were adipose/soft tissue and bone/soft tissue. As the patients have been imaged on different table tops, part of the misclassification error can be explained by misregistration. Conclusion: The proposed approach does not rely on an anatomy model providing the flexibility to successfully generate the pCT in two different body sites. This research is founded by ZonMw IMDI Programme, project name: “RASOR sharp: MRI based radiotherapy planning using a single MRI sequence”, project number: 10-104003010.« less

Investigation of composition and structure of spongy and hard bone tissue using FTIR spectroscopy, XRD and SEM

NASA Astrophysics Data System (ADS)

Al-Akhras, M.-Ali H.; Hasan Qaseer, M. K.; Albiss, B. A.; Alebrhim, M. Anwar; Gezawa, Umar S.

2018-02-01

Valuable structural and chemical features can be obtained for spongy and hard bone by infrared spectroscopy and X-ray diffraction. A better understanding of chemical and structural differences between spongy and hard bone is a very important contributor to bone quality. Our data according to IR data showed that the collagen cross-links occurred to be higher in spongy bone, and crystallinity was lower in spongy bone. Deconvolution of the infrared band near 870 cm-1 reveals evidence for A2-type carbonate substitution on hydroxyapatite of spongy bone in addition to the A and B type carbonate substitution that are also found in hard bone. IR and XRD data confirmed the results of each other since full width at half maximum of 002-apatite pattern of XRD showed that the crystallinity was lower in spongy bone. The microstructure was examined by using scanning electron microscope and the result showed that the lattice of thin threads in spongy bone and is less dense than hard bone.

Development of digital shade guides for color assessment using a digital camera with ring flashes.

PubMed

Tung, Oi-Hong; Lai, Yu-Lin; Ho, Yi-Ching; Chou, I-Chiang; Lee, Shyh-Yuan

2011-02-01

Digital photographs taken with cameras and ring flashes are commonly used for dental documentation. We hypothesized that different illuminants and camera's white balance setups shall influence color rendering of digital images and affect the effectiveness of color matching using digital images. Fifteen ceramic disks of different shades were fabricated and photographed with a digital camera in both automatic white balance (AWB) and custom white balance (CWB) under either light-emitting diode (LED) or electronic ring flash. The Commission Internationale d'Éclairage L*a*b* parameters of the captured images were derived from Photoshop software and served as digital shade guides. We found significantly high correlation coefficients (r² > 0.96) between the respective spectrophotometer standards and those shade guides generated in CWB setups. Moreover, the accuracy of color matching of another set of ceramic disks using digital shade guides, which was verified by ten operators, improved from 67% in AWB to 93% in CWB under LED illuminants. Probably, because of the inconsistent performance of the flashlight and specular reflection, the digital images captured under electronic ring flash in both white balance setups revealed less reliable and relative low-matching ability. In conclusion, the reliability of color matching with digital images is much influenced by the illuminants and camera's white balance setups, while digital shade guides derived under LED illuminants with CWB demonstrate applicable potential in the fields of color assessments.

Back-scattered electron imaging of skeletal tissues.

PubMed

Boyde, A; Jones, S J

The use of solid-state back-scattered electron (BSE) detectors in the scanning electron microscopic study of skeletal tissues has been investigated. To minimize the topographic element in the image, flat samples and a ring detector configuration with the sample at normal incidence to the beam and the detector are used. Very flat samples are prepared by diamond micromilling or diamond polishing plastic-embedded tissue. Density discrimination in the image is so good that different density phases within mineralized bone can be imaged. For unembedded spongy bone, cut surfaces can be discriminated from natural surfaces by a topographic contrast mechanism. BSE imaging also presents advantages for unembedded samples with rough topography, such as anorganic preparations of the mineralization zone in cartilage, which give rise to severe charging problems with conventional secondary electron imaging.

Analysis of dental supportive structures in orthodontic therapy.

PubMed

Pavicin, Ivana Savić; Ivosević-Magdalenić, Natasa; Badel, Tomislav; Basić, Kresimir; Keros, Jadranka

2012-09-01

The purpose was to define the impact of orthodontic appliances on the density of the underlying dental bone tissue. Radiographic images of teeth were made in 27 study subjects before and twelve months after fixed orthodontic appliances were carried. The radiographs were digitalized and the levels of gray at sites where the greatest bone resorption was expected were transformed into optic density. In the standardization and comparison of values from the first and the second measurements the copper calibration wedge--a stepwedge--was used. Optic densities in the observed sites were compared with optic densities of the calibration wedge and expressed as their thickness equivalent. The study results showed no statistically significant difference in bone densities, indicating that the orthodontic therapy was properly planned and carried out and that excessive forces were not used in the applied correctional procedures.

Understanding bone responses in B-mode ultrasound images and automatic bone surface extraction using a Bayesian probabilistic framework

NASA Astrophysics Data System (ADS)

Jain, Ameet K.; Taylor, Russell H.

2004-04-01

The registration of preoperative CT to intra-operative reality systems is a crucial step in Computer Assisted Orthopedic Surgery (CAOS). The intra-operative sensors include 3D digitizers, fiducials, X-rays and Ultrasound (US). Although US has many advantages over others, tracked US for Orthopedic Surgery has been researched by only a few authors. An important factor limiting the accuracy of tracked US to CT registration (1-3mm) has been the difficulty in determining the exact location of the bone surfaces in the US images (the response could range from 2-4mm). Thus it is crucial to localize the bone surface accurately from these images. Moreover conventional US imaging systems are known to have certain inherent inaccuracies, mainly due to the fact that the imaging model is assumed planar. This creates the need to develop a bone segmentation framework that can couple information from various post-processed spatially separated US images (of the bone) to enhance the localization of the bone surface. In this paper we discuss the various reasons that cause inherent uncertainties in the bone surface localization (in B-mode US images) and suggest methods to account for these. We also develop a method for automatic bone surface detection. To do so, we account objectively for the high-level understanding of the various bone surface features visible in typical US images. A combination of these features would finally decide the surface position. We use a Bayesian probabilistic framework, which strikes a fair balance between high level understanding from features in an image and the low level number crunching of standard image processing techniques. It also provides us with a mathematical approach that facilitates combining multiple images to augment the bone surface estimate.

Prediction of low bone mass using a combinational approach of cortical and trabecular bone measures from dental panoramic radiographs.

PubMed

Kathirvelu, D; Anburajan, M

2014-09-01

The aim of this study is to extract cortical and trabecular features of the mandible and to develop a novel combinational model of mandibular cortical thickness, trabecular bone area and age in order to predict low bone mineral density or osteoporosis from a dental panoramic radiograph. The study involved 64 south Indian women (age = 52.5 ± 12.7 years) categorised into two groups (normal and low bone mineral density) based on total femur bone mineral density. The dental panoramic radiographs were obtained by a digital scanner, and measurement of total bone mineral density at the right femur was performed by a dual-energy X-ray absorptiometry scanner. The mandibular cortical thickness and panoramic mandibular index were measured bilaterally, and the mean values were considered. The region of interest of 128 × 128 pixels around the mental foramen region was manually cropped and subjected to pre-processing, normalisation and average threshold-based segmentation to determine trabecular bone area. Multiple linear regression analyses of cortical and trabecular measures along with age were performed to develop a combinational model to classify subjects as normal and low bone mineral density. The proposed approach demonstrated strong correlation (r = 0.76; p < 0.01) against the total bone mineral density and resulted in accuracy, sensitivity and positive predictive values of 0.84, 0.92 and 0.85, respectively; the receiver operating characteristic outcomes disclosed that the area under the curve was 0.89.Our results suggest that the proposed combinational model could be useful to diagnose subjects with low bone mineral density. © IMechE 2014.

Strike Up the Score: Deriving Searchable and Playable Digital Formats from Sheet Music; Smart Objects and Open Archives; Building the Archives of the Future: Advanced in Preserving Electronic Records at the National Archives and Records Administration; From the Digitized to the Digital Library.

ERIC Educational Resources Information Center

Choudhury, G. Sayeed; DiLauro, Tim; Droettboom, Michael; Fujinaga, Ichiro; MacMillan, Karl; Nelson, Michael L.; Maly, Kurt; Thibodeau, Kenneth; Thaller, Manfred

2001-01-01

These articles describe the experiences of the Johns Hopkins University library in digitizing their collection of sheet music; motivation for buckets, Smart Object, Dumb Archive (SODA) and the Open Archives Initiative (OAI), and initial experiences using them in digital library (DL) testbeds; requirements for archival institutions, the National…

Comparison of Autograft and Allograft with Surface Modification for Flexor Tendon Reconstruction: A Canine in Vivo Model.

PubMed

Wei, Zhuang; Reisdorf, Ramona L; Thoreson, Andrew R; Jay, Gregory D; Moran, Steven L; An, Kai-Nan; Amadio, Peter C; Zhao, Chunfeng

2018-04-04

Flexor tendon injury is common, and tendon reconstruction is indicated clinically if the primary repair fails or cannot be performed immediately after tendon injury. The purpose of the current study was to compare clinically standard extrasynovial autologous graft (EAG) tendon and intrasynovial allogeneic graft (IAG) that had both undergone biolubricant surface modification in a canine in vivo model. Twenty-four flexor digitorum profundus (FDP) tendons from the second and fifth digits of 12 dogs were used for this study. In the first phase, a model of failed FDP tendon repair was created. After 6 weeks, the ruptured FDP tendons with a scarred digit were reconstructed with the use of either EAG or IAG tendons treated with carbodiimide-derivatized hyaluronic acid and lubricin. At 12 weeks after tendon reconstruction, the digits were harvested for functional, biomechanical, and histologic evaluations. The tendon failure model was a clinically relevant and reproducible model for tendon reconstruction. The IAG group demonstrated improved digit function with decreased adhesion formation, lower digit work of flexion, and improved graft gliding ability compared with the EAG group. However, the IAG group had decreased healing at the distal tendon-bone junction. Our histologic findings verified the biomechanical evaluations and, further, showed that cellular repopulation of allograft at 12 weeks after reconstruction is still challenging. FDP tendon reconstruction using IAG with surface modification has some beneficial effects for reducing adhesions but demonstrated inferior healing at the distal tendon-bone junction compared with EAG. These mixed results indicate that vitalization and turnover acceleration are crucial to reducing failure of reconstruction with allograft. Flexor tendon reconstruction is a common surgical procedure. However, postoperative adhesion formation may lead to unsatisfactory clinical outcomes. In this study, we developed a potential flexor tendon allograft using chemical and tissue-engineering approaches. This technology could improve function following tendon reconstruction.

OPTOELECTRONICS, FIBER OPTICS, AND OTHER ASPECTS OF QUANTUM ELECTRONICS: Nonlinear optical devices: basic elements of a future optical digital computer?

NASA Astrophysics Data System (ADS)

Fischer, R.; Müller, R.

1989-08-01

It is shown that nonlinear optical devices are the most promising elements for an optical digital supercomputer. The basic characteristics of various developed nonlinear elements are presented, including bistable Fabry-Perot etalons, interference filters, self-electrooptic effect devices, quantum-well devices utilizing transitions between the lowest electron states in the conduction band of GaAs, etc.

Effect of surface chemistry on the rate of osseointegration of sintered porous-surfaced Ti-6Al-4V implants.

PubMed

Taché, Alex; Gan, Lu; Deporter, Douglas; Pilliar, Robert M

2004-01-01

The effect of adding a thin sol-gel-formed calcium phosphate (CaP) coating to sintered porous-surfaced titanium alloy (Ti-6Al-4V) implants on rates of initial bone ingrowth was investigated. Control implants (as manufactured) and similar implants with sol-gel CaP coatings were randomly placed in distal femoral rabbit condyles (1 implant/leg). After healing for 6, 9, 12, and 16 days, 8 of 10 rabbits in each time group were assessed for maximum implant pullout force (N) and interface stiffness (N/mm). Selected extracted implants also were examined by secondary electron imaging to characterize affected surfaces. The implants of the remaining 2 rabbits in each group were examined by backscattered scanning electron microscopy (BSEM). Significantly greater pullout forces and interface stiffness were found for CaP-coated implants at 6 and 9 days. At 6 days, BSEM revealed bone ingrowth on CaP-coated implants but not on control implants. Secondary electron imaging and BSEM observations also suggested greater bone ingrowth with CaP-coated porous implants at 9, 12, and 16 days. Sol-gel-formed CaP surface films significantly enhance rates of bone ingrowth into sintered porous-surfaced implants. This surface treatment may have a number of clinical benefits, including shortening the period prior to functional loading of such implants and improving treatment outcomes in situations of poor bone quality and/or quantity. (More than 50 references).

TCP is hardly resorbed and not osteoconductive in a non-loading calvarial model.

PubMed

Handschel, Jörg; Wiesmann, Hans Peter; Stratmann, Udo; Kleinheinz, Johannes; Meyer, Ulrich; Joos, Ulrich

2002-04-01

Tricalciumphosphate (TCP) has been used as a ceramic bone substitute material in the orthopedic field as well as in craniofacial surgery. Some controversies exist concerning the osteoconductive potential of this material in different implantation sites. This study was designed to evaluate the biological response of calvarial bone towards TCP granules under non-loading conditions to assess the potential of TCP as a biodegredable and osteoconductive bone substitue material for the cranial vault. Full-thickness non-critical size defects were made bilaterally in the calvaria of 21 adult Wistar rats. One side was filled by TCP granules, the contralateral side was left empty and used as a control. Animals were sacrified in defined time intervals up to 6 months. Bone regeneration was analyzed with special respect toward the micromorphological and microanalytical features of the material-bone interaction by electron microscopy and electron diffraction analysis. Histologic examination revealed no TCP degradation even after 6 months of implantation. In contrast, a nearly complete bone regeneration of control defects was found after 6 months. At all times TCP was surrounded by a thin fibrous layer without presence of osteoblasts and features of regular mineralization. As far as degradation and substitution are concerned, TCP is a less favourable material tinder conditions of non-loading.

Flesh and Bone: Information Literacy, Teaching, and the Connected Classroom.

ERIC Educational Resources Information Center

Lant, Kathleen Margaret

This paper discusses information literacy, teaching, and online technology. The first section introduces the split between mind and body that is made possible by the Internet and related resources. The second section discusses distance learning, including the impact of digital environments in teaching, and the power of virtual education to permit…

Macrophages are required to coordinate mouse digit tip regeneration.

PubMed

Simkin, Jennifer; Sammarco, Mimi C; Marrero, Luis; Dawson, Lindsay A; Yan, Mingquan; Tucker, Catherine; Cammack, Alex; Muneoka, Ken

2017-11-01

In mammals, macrophages are known to play a major role in tissue regeneration. They contribute to inflammation, histolysis, re-epithelialization, revascularization and cell proliferation. Macrophages have been shown to be essential for regeneration in salamanders and fish, but their role has not been elucidated in mammalian epimorphic regeneration. Here, using the regenerating mouse digit tip as a mammalian model, we demonstrate that macrophages are essential for the regeneration process. Using cell-depletion strategies, we show that regeneration is completely inhibited; bone histolysis does not occur, wound re-epithelialization is inhibited and the blastema does not form. Although rescue of epidermal wound closure in the absence of macrophages promotes blastema accumulation, it does not rescue cell differentiation, indicating that macrophages play a key role in the redifferentiation of the blastema. We provide additional evidence that although bone degradation is a component, it is not essential to the overall regenerative process. These findings show that macrophages play an essential role in coordinating the epimorphic regenerative response in mammals. © 2017. Published by The Company of Biologists Ltd.

A novel interpolation approach for the generation of 3D-geometric digital bone models from image stacks

PubMed Central

Mittag, U.; Kriechbaumer, A.; Rittweger, J.

2017-01-01

The authors propose a new 3D interpolation algorithm for the generation of digital geometric 3D-models of bones from existing image stacks obtained by peripheral Quantitative Computed Tomography (pQCT) or Magnetic Resonance Imaging (MRI). The technique is based on the interpolation of radial gray value profiles of the pQCT cross sections. The method has been validated by using an ex-vivo human tibia and by comparing interpolated pQCT images with images from scans taken at the same position. A diversity index of <0.4 (1 meaning maximal diversity) even for the structurally complex region of the epiphysis, along with the good agreement of mineral-density-weighted cross-sectional moment of inertia (CSMI), demonstrate the high quality of our interpolation approach. Thus the authors demonstrate that this interpolation scheme can substantially improve the generation of 3D models from sparse scan sets, not only with respect to the outer shape but also with respect to the internal gray-value derived material property distribution. PMID:28574415

[INVITED] Laser-induced forward transfer: A high resolution additive manufacturing technology

NASA Astrophysics Data System (ADS)

Delaporte, Philippe; Alloncle, Anne-Patricia

2016-04-01

Among the additive manufacturing techniques, laser-induced forward transfer addresses the challenges of printing thin films in solid phase or small volume droplets in liquid phase with very high resolution. This paper reviews the physics of this process and explores the pros and cons of this technology versus other digital printing technologies. The main field of applications are printed electronics, organic electronics and tissue engineering, and the most promising short terms ones concern digital laser printing of sensors and conductive tracks. Future directions and emerging areas of interest are discussed such as printing solid from a liquid phase and 3D digital nanomanufacturing.

Investigation of a nozzle instability on an F100 engine equipped with a digital electronic engine control

NASA Technical Reports Server (NTRS)

Burcham, F. W., Jr.; Zeller, J. R.

1984-01-01

An instability in the nozzle of the F100 engine, equipped with a digital electronic engine control (DEEC), was observed during a flight evaluation on an F-15 aircraft. The instability occurred in the upper left hand corner (ULMC) of the flight envelope during augmentation. The instability was not predicted by stability analysis, closed-loop simulations of the the engine, or altitude testing of the engine. The instability caused stalls and augmentor blowouts. The nozzle instability and the altitude testing are described. Linear analysis and nonlinear digital simulation test results are presented. Software modifications on further flight test are discussed.

Flight testing the digital electronic engine control in the F-15 airplane

NASA Technical Reports Server (NTRS)

Myers, L. P.

1984-01-01

The digital electronic engine control (DEEC) is a full-authority digital engine control developed for the F100-PW-100 turbofan engine which was flight tested on an F-15 aircraft. The DEEC hardware and software throughout the F-15 flight envelope was evaluated. Real-time data reduction and data display systems were implemented. New test techniques and stronger coordination between the propulsion test engineer and pilot were developed which produced efficient use of test time, reduced pilot work load, and greatly improved quality data. The engine pressure ratio (EPR) control mode is demonstrated. It is found that the nonaugmented throttle transients and engine performance are satisfactory.

Overview of the CCITT Recommendations for Synchronous Digital Hierarchy

DTIC Science & Technology

1991-10-01

Recommendations for8 Synchronous Digital Hierarchy DCK RAPPORTENCEN’TRiLEAD-A245 680 Frederikkazerne, Geb. 140EN 1111 iNTelefcron: 070-3166394/6395... Synchronous Digital Hierarchy author(s) P.P. Copeland institute TNO Physics and Electronics Laboratory date October 1991 NDRO no A90KLu635 no in pow...recent International Consultative Committee for Telephone and Telegraph (CCITT) Recommendations for the Synchronous Digital Hierarchy (SDH). The

75 FR 24998 - In the Matter of Florida Power and Light Company: Turkey Point Nuclear Plant; Independent Spent...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-06

..., to request (1) a digital ID certificate, which allows the participant (or its counsel or... NRC- issued digital ID certificate). Based upon this information, the Secretary will establish an... electronic docket. Information about applying for a digital ID certificate is available on NRC's public Web...

Do You Hear What I See? Assessing Accessibility of Digital Commons and CONTENTdm

ERIC Educational Resources Information Center

Walker, Wendy; Keenan, Teressa

2015-01-01

This article discusses the accessibility of two content management systems, Berkeley Electronic Press's Digital Commons and OCLC's CONTENTdm, widely used in libraries to host institutional repository and digital collections content. Based on observations by a visually impaired student who used the JAWS screen reader to view the design and display…

A Typology for Analyzing Digital Curricula in Mathematics Education

ERIC Educational Resources Information Center

Choppin, Jeffrey; Carson, Cynthia; Borys, Zenon; Cerosaletti, Cathleen; Gillis, Rob

2014-01-01

Digital content is increasingly present in U.S. K-12 classrooms, with a current push by federal officials to increase the rate at which digital textbooks are adopted. While some teachers' use of electronic resources involves locating activities and lessons from various internet sites, textbook and educational software companies have begun to…

Digitizing a Cultural Heritage--The Key Issue for Preservation and Electronic Publishing.

ERIC Educational Resources Information Center

Bogen, Manfred; Bonkowski, Christian; Borowski, Marion; Loffler, Jobst

This paper describes a realization approach to evaluate the best fitting service provider in the context of "The Digital Beethoven House" pilot project, involving the digitizing of a composer-referred collection of colored manuscripts and other sources at the Beethoven House Association (Germany). Practical hints for museums are provided…

Empowering Student Voice through Interactive Design and Digital Making

ERIC Educational Resources Information Center

Kim, Yanghee; Searle, Kristin

2017-01-01

Over the last two decades online technology and digital media have provided space for students to participate and express their voices. This paper further explores how new digital technologies, such as humanoid robots and wearable electronics, can be used to offer additional spaces where students' voices are heard. In these spaces, young students…

IoT-Forensics Meets Privacy: Towards Cooperative Digital Investigations

PubMed Central

Lopez, Javier

2018-01-01

IoT-Forensics is a novel paradigm for the acquisition of electronic evidence whose operation is conditioned by the peculiarities of the Internet of Things (IoT) context. As a branch of computer forensics, this discipline respects the most basic forensic principles of preservation, traceability, documentation, and authorization. The digital witness approach also promotes such principles in the context of the IoT while allowing personal devices to cooperate in digital investigations by voluntarily providing electronic evidence to the authorities. However, this solution is highly dependent on the willingness of citizens to collaborate and they may be reluctant to do so if the sensitive information within their personal devices is not sufficiently protected when shared with the investigators. In this paper, we provide the digital witness approach with a methodology that enables citizens to share their data with some privacy guarantees. We apply the PRoFIT methodology, originally defined for IoT-Forensics environments, to the digital witness approach in order to unleash its full potential. Finally, we show the feasibility of a PRoFIT-compliant digital witness with two use cases. PMID:29414864

IoT-Forensics Meets Privacy: Towards Cooperative Digital Investigations.

PubMed

Nieto, Ana; Rios, Ruben; Lopez, Javier

2018-02-07

IoT-Forensics is a novel paradigm for the acquisition of electronic evidence whose operation is conditioned by the peculiarities of the Internet of Things (IoT) context. As a branch of computer forensics, this discipline respects the most basic forensic principles of preservation, traceability, documentation, and authorization. The digital witness approach also promotes such principles in the context of the IoT while allowing personal devices to cooperate in digital investigations by voluntarily providing electronic evidence to the authorities. However, this solution is highly dependent on the willingness of citizens to collaborate and they may be reluctant to do so if the sensitive information within their personal devices is not sufficiently protected when shared with the investigators. In this paper, we provide the digital witness approach with a methodology that enables citizens to share their data with some privacy guarantees. We apply the PRoFIT methodology, originally defined for IoT-Forensics environments, to the digital witness approach in order to unleash its full potential. Finally, we show the feasibility of a PRoFIT-compliant digital witness with two use cases.

Development of a digital method for neutron/gamma-ray discrimination based on matched filtering

NASA Astrophysics Data System (ADS)

Korolczuk, S.; Linczuk, M.; Romaniuk, R.; Zychor, I.

2016-09-01

Neutron/gamma-ray discrimination is crucial for measurements with detectors sensitive to both neutron and gamma-ray radiation. Different techniques to discriminate between neutrons and gamma-rays based on pulse shape analysis are widely used in many applications, e.g., homeland security, radiation dosimetry, environmental monitoring, fusion experiments, nuclear spectroscopy. A common requirement is to improve a radiation detection level with a high detection reliability. Modern electronic components, such as high speed analog to digital converters and powerful programmable digital circuits for signal processing, allow us to develop a fully digital measurement system. With this solution it is possible to optimize digital signal processing algorithms without changing any electronic components in an acquisition signal path. We report on results obtained with a digital acquisition system DNG@NCBJ designed at the National Centre for Nuclear Research. A 2'' × 2'' EJ309 liquid scintillator was used to register mixed neutron and gamma-ray radiation from PuBe sources. A dedicated algorithm for pulse shape discrimination, based on real-time filtering, was developed and implemented in hardware.

Slab fractures of the third tarsal bone: Minimally invasive repair using a single 3.5 mm cortex screw placed in lag fashion in 17 Thoroughbred racehorses.

PubMed

Barker, W H J; Wright, I M

2017-03-01

A technique for minimally invasive repair of slab fractures of the third tarsal bone has not previously been reported. Results of third tarsal bone slab fracture repair in Thoroughbred racehorses are lacking. To report the outcomes of repair of uniplanar frontal slab factures of the third tarsal bone using a single 3.5 mm cortex screw in lag fashion. Retrospective case series. Case records of horses that had undergone this procedure were reviewed. Seventeen horses underwent surgery. Eighteen percent of cases had wedge shaped third tarsal bones. A point midway between the long and lateral digital extensor tendons and centrodistal and tarsometatarsal joints created a suitable entry site for implants. The fracture location, configuration and curvature of the third tarsal bone and associated joints requires a dorsolateral proximal-plantaromedial distal trajectory for the screw, which was determined by preplaced needles. There were no complications and fractures healed in all cases at 4-6 months post surgery. Seventy-nine percent of horses returned to racing and, at the time of reporting, 3 are in post operative rehabilitation programmes. The technique reported provides a safe, appropriate and repeatable means of repairing slab fractures of the third tarsal bone. Surgical repair is a viable alternative to conservative management. © 2016 EVJ Ltd.

Does cone beam CT actually ameliorate stab wound analysis in bone?

PubMed

Gaudio, D; Di Giancamillo, M; Gibelli, D; Galassi, A; Cerutti, E; Cattaneo, C

2014-01-01

This study aims at verifying the potential of a recent radiological technology, cone beam CT (CBCT), for the reproduction of digital 3D models which may allow the user to verify the inner morphology of sharp force wounds within the bone tissue. Several sharp force wounds were produced by both single and double cutting edge weapons on cancellous and cortical bone, and then acquired by cone beam CT scan. The lesions were analysed by different software (a DICOM file viewer and reverse engineering software). Results verified the limited performances of such technology for lesions made on cortical bone, whereas on cancellous bone reliable models were obtained, and the precise morphology within the bone tissues was visible. On the basis of such results, a method for differential diagnosis between cutmarks by sharp tools with a single and two cutting edges can be proposed. On the other hand, the metrical computerised analysis of lesions highlights a clear increase of error range for measurements under 3 mm. Metric data taken by different operators shows a strong dispersion (% relative standard deviation). This pilot study shows that the use of CBCT technology can improve the investigation of morphological stab wounds on cancellous bone. Conversely metric analysis of the lesions as well as morphological analysis of wound dimension under 3 mm do not seem to be reliable.

Morphological texture assessment of oral bone as a screening tool for osteoporosis

NASA Astrophysics Data System (ADS)

Analoui, Mostafa; Eggertsson, Hafsteinn; Eckert, George

2001-07-01

Three classes of texture analysis approaches have been employed to assess the textural characteristic of oral bone. A set of linear structuring elements was used to compute granulometric features of trabecular bone. Multifractal analysis was also used to compute the fractal dimension of the corresponding tissues. In addition, some statistical features and histomorphometric parameters were computed. To assess the proposed approach we acquired digital intraoral radiographs of 47 subjects (14 males and 33 females). All radiographs were captured at 12 bits/pixel. Images were converted to binary form through a sliding locally adaptive thresholding approach. Each subject was scanned by DEXA for bone dosimetry. Subject were classified into one of the following three categories according World Health Organization (WHO) standard (1) healthy, (2) with osteopenia and (3) osteoporosis. In this study fractal dimension showed very low correlation with bone mineral density (BMD) measurements, which did not reach a level of statistical significance (p<0.5). However, entropy of pattern spectrum (EPS), along with statistical features and histomorphometric parameters, has shown correlation coefficients ranging from low to high, with statistical significance for both males and females. The results of this study indicate the utility of this approach for bone texture analysis. It is conjectured that designing a 2-D structuring element, specially tuned to trabecular bone texture, will increase the efficacy of the proposed method.

Growth-Associated Changes in the Periodontal Bone and Molar Teeth of Male Rats

PubMed Central

García, María F; Moreno, Hilda; Rigalli, Alfredo; Puche, Rodolfo C

2009-01-01

Here we report quantitative data associating periodontal bone variables of young conventional rats with the growth process. The hemimandibles of male rats (IIM/Fm stock, 2 to 15 wk of age.) were excised and submitted to conventional morphologic, radiologic, and histologic evaluation. The length, area, or X-ray absorbance of various regions or structures was measured on digital images of radiographs by using an image-analysis program. The sum of periodontal bone areas undergoing resorption (interproximal + intraradicular) increased until 9 or 10 wk of age and decreased thereafter. Mineral accretion rates and mineral density asymptotes were not significantly different among molars. The mineral density of resorption areas in alveolar bone fitted sinusoidal kinetics, indicative of the ‘instability’ of the tissue due to its high metabolic activity. Mineral accretion rates and mineral density asymptotes were not significantly different among molars. The proportion of root length within alveolar bone exhibited a biphasic curve (minimum at 5 wk of age), due to differences in the growth rates of variables involved in its calculation (distance between the cementoenamel junction to the apex and height of the resorption areas). The distance between the cementoenamel junction and alveolar bone crest over time fitted a sigmoidal function with a point of inflection that did not differ significantly from that of body or mandible dry weight. In summary, the growth process appears to affect periodontal bone support and the distance between the cementoenamel junction and alveolar bone crest in male rats. PMID:19807966

Electron absorbed fractions of energy and S-values in an adult human skeleton based on µCT images of trabecular bone

NASA Astrophysics Data System (ADS)

Kramer, R.; Richardson, R. B.; Cassola, V. F.; Vieira, J. W.; Khoury, H. J.; Lira, C. A. B. de O.; Robson Brown, K.

2011-03-01

When the human body is exposed to ionizing radiation, among the soft tissues at risk are the active marrow (AM) and the bone endosteum (BE) located in tiny, irregular cavities of trabecular bone. Determination of absorbed fractions (AFs) of energy or absorbed dose in the AM and the BE represent one of the major challenges of dosimetry. Recently, at the Department of Nuclear Energy at the Federal University of Pernambuco, a skeletal dosimetry method based on µCT images of trabecular bone introduced into the spongiosa voxels of human phantoms has been developed and applied mainly to external exposure to photons. This study uses the same method to calculate AFs of energy and S-values (absorbed dose per unit activity) for electron-emitting radionuclides known to concentrate in skeletal tissues. The modelling of the skeletal tissue regions follows ICRP110, which defines the BE as a 50 µm thick sub-region of marrow next to the bone surfaces. The paper presents mono-energetic AFs for the AM and the BE for eight different skeletal regions for electron source energies between 1 keV and 10 MeV. The S-values are given for the beta emitters 14C, 59Fe, 131I, 89Sr, 32P and 90Y. Comparisons with results from other investigations showed good agreement provided that differences between methodologies and trabecular bone volume fractions were properly taken into account. Additionally, a comparison was made between specific AFs of energy in the BE calculated for the actual 50 µm endosteum and the previously recommended 10 µm endosteum. The increase in endosteum thickness leads to a decrease of the endosteum absorbed dose by up to 3.7 fold when bone is the source region, while absorbed dose increases by ~20% when the beta emitters are in marrow.

Digital rights language support for evolving digital cinema requirements

NASA Astrophysics Data System (ADS)

Orri, Xavier; Mas, Joan-Maria; Macq, Benoit M. M.

2003-06-01

Digital cinema can be defined as the digital electronic distribution and display of theatrical film content or live material to the theatre. However, this simple definition does not reflect the complex mesh of balanced business relationships between the different parties involved in the worldwide cinematic distribution. Its transition from an analogue to a digital business will happen progressively, starting with only content being digitally distributed and going until an all-digital business. From these facts derive strong requirements on digital rights management (DRM) systems for digital cinema and therefore on the digital rights language supporting it. This paper explores the requirements imposed by the cinematic distribution model and by its progressive transition to digital, and the impact these have on digital rights languages. We analyze the support provided by different digital rights languages, identifying weaknesses and exploring solutions in fulfilling the requirements of the digital cinema distribution model.

CAD - CAM Procedures Used for Rapid Prototyping of Prosthetic Hip Joint Bone

NASA Astrophysics Data System (ADS)

Popa, Luminita I.; Popa, Vasile N.

2016-11-01

The article addresses the issue of rapid prototyping CAD/ CAM procedures, based on CT imaging, for custom implants dedicated to hip arthroplasty and the correlation study to be achieved between femoral canal shape, valued by modern imaging methods, and the prosthesis form. A set of CT images is transformed into a digital model using one of several software packages available for conversion. The purpose of research is to obtain prosthesis with compatible characteristics as close to the physiological, with an optimal adjustment of the prosthesis to the bone in which it is implanted, allowing the recovery of the patient physically, mentally and socially.

Applying 3D-printing technology in planning operations of cancer patients

NASA Astrophysics Data System (ADS)

Kashapov, L. N.; N, A. N. Rudyk A.; Kashapov, R. N.

2014-12-01

The purpose of this work was creation 3D model of the front part of the skull of the patient and evaluates the effectiveness of its use in the planning of the operation. To achieve this goal was chosen an operation to remove a tumor of the right eyelid, germinate in the zygomatic bone. 3D printing was performed at different peripheral devices using the method of layering creating physical objects by a digital 3D model as well as the recovery model of the skull with the entire right malar bone for fixation on her titanium frame to maintain the eyeball in a fixed state.