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Sample records for head scatter factors

  1. Linac head scatter factor for asymmetric radiation field

    NASA Astrophysics Data System (ADS)

    Soubra, Mazen Ahmed

    1997-11-01

    The head scatter factor, Sh is an important dosimetric quantity used in radiation therapy dose calculation. It is empirically determined and its field size dependence reflects changes in photon scatter from components in the linac treatment head. In this work a detailed study of the physical factors influencing the determination of Sh was performed with particular attention given to asymmetric field geometries. Ionization measurements for 6 and 18 MV photon beams were made to examine the factors which determine Sh. These include: phantom size and material, collimator backscatter, non-lateral electronic equilibrium (LEE) conditions, electron contamination, collimator-exchange, photon energy, flattening filter and off-axis distance (OAD). Results indicated that LEE is not required for Sh measurements if electron contamination is minimized. Brass caps or polystyrene miniphantoms can both be used in Sh measurements provided the phantom thickness is large enough to stop contaminant electrons. Backscatter radiation effects into the monitor chamber were found to be negligible for the Siemens linac. It was found that the presence and shape of the flattening filter had a significant effect on the empirically determined value of Sh was also shown to be a function of OAD, particularly for small fields. For fields larger than 12×12 cm2/ Sh was independent of OAD. A flattening filter mass model was introduced to explain qualitatively the above results. A detailed Monte Carlo simulation of the Siemens KD2 linac head in 6 MV mode was performed to investigate the sources of head scatter which contribute to the measured Sh. The simulated head components include the flattening filter, the electron beam stopper, the primary collimator, the photon monitor chamber and the secondary collimators. The simulations showed that the scatter from the head of the Siemens linac is a complex function of the head components. On the central axis the flattening filter played the dominant role in

  2. Study of head scatter factor in 4MV photon beam used in radiotherapy.

    PubMed

    Appasamy, Murugan; Xavier, Sidonia Valas; Kuppusamy, Thayalan; Velayudham, Ramasubramanian

    2013-06-01

    The 4 MV photon beam offers equal build-up region behavior like Co-60 beam and it plays a major role in head and neck and pediatric radiotherapy. In this study an attempt is made to study the head scatter factor (SC) for 4 MV photon beam using locally designed PMMA and Brass miniphantoms. The SC is measured in combination of PMMA miniphantom with 0.6 cc chamber and Brass miniphantom with 0.6 cc and 0.13 cc chambers. The measured SC is compared with the literature data and it agrees within ± 1.98%. The study reveals that either 0.13 cc or 0.6 cc chamber with PMMA or Brass phantom materials can be used for SC measurements in a 4 MV photon beam. The variation of SSD does not alter the head scatter factor. The collimator exchange effect is found to be within 1, and it is less than that of other linear accelerators. It is also found that the presence of internal wedge has significant contribution to head scatter factor. The Phantom scatter factor is also calculated and it agrees within ±1% with published data.

  3. Measurements of head-scatter factors with cylindrical build-up caps and columnar miniphantoms.

    PubMed

    Jursinic, P A; Thomadsen, B R

    1999-04-01

    Head-scatter factors, Sh, also referred to as output factors, are measured in-air with an ion chamber and a semiconductor diode fitted with cylindrical build-up caps and columnar miniphantoms fabricated from materials of different atomic number. Sh increases with field size less rapidly when cylindrical build-up caps are constructed from high atomic number materials. This is a consequence of a net scatter of contamination electrons away from the detector. Ion chambers and diodes give identical results when the same type of build-up caps are used. Contamination electrons can be avoided by the use of columnar miniphantoms that have sufficient wall thickness in the radial direction. This radial wall thickness is characterized in this work for 6, 10, and 18 MV x-ray beams. Sh increases with field size less rapidly when columnar miniphantoms are constructed from high atomic number materials. This is due to the decrease in the average energy of photons at large field sizes. It is concluded that to obtain Sh for dosimetry in water, cylindrical build-up caps and columnar miniphantoms should be constructed from material with an atomic number close to that of water.

  4. Measurement of Head Scatter Factor for Linear Accelerators using Indigenously Designed Columnar Mini Phantom

    NASA Astrophysics Data System (ADS)

    Appasamy, Murugan; Xavier, Sidonia; Kuppusamy, Thayalan; Velayudham, Ramasubramanian

    2011-01-01

    A columnar mini phantom is designed as recommended by ESTRO to measure the Head Scatter Factor (Sc) for 6 MV beam of two linear accelerators. The measurement of Sc at different orientations of the chamber, parallel and perpendicular at 1.5 cm depth predicts the deviation of 2.05% and 1.9% for Elekta and Siemens linear accelerators respectively. The measurement of Sc at 1.5 cm is higher compared to 10 cm depth for both the linear accelerators suggesting the electron contamination at 1.5 cm depth. The effect of wedges on Sc yields a significant contribution of 3.5% and 5% for Siemens and Elekta linear accelerators respectively. The collimator exchange effect reveals the opening of upper jaw increases the Sc irrespective of the linear accelerator. The result emphasizes the need of Sc measurement at 10 cm. The presence of wedge influences the Sc value and the SSD has no influence on Sc. The measured Sc values are in good agreement with the published data.

  5. Build-up cap materials for measurement of photon head-scatter factors.

    PubMed

    Weber, L; Nilsson, P; Ahnesjö, A

    1997-10-01

    The suitability of high-Z materials as build-up caps for head-scatter measurements has been investigated. Build-up caps are often used to enable characterization of fields too small for a mini-phantom. We have studied lead and brass build-up caps with sufficiently large wall thicknesses, as compared to the range of contaminating electrons originating in the accelerator head, and compared them with build-up caps made of ionization chamber equivalent materials, i.e. graphite. The results were also compared with measurements taken using square and cylindrical polystyrene mini-phantoms. Field sizes ranging from 3 cm x 3 cm up to 40 cm x 40 cm were studied for nominal photon energies of 4, 6, 10 and 18 MV. The results show that the use of lead and brass build-up caps produces normalized head-scatter data slightly different from graphite build-up caps for large fields at high photon energies. At lower energies, however, no significant differences were found. The intercomparison between the two different plastic mini-phantoms and graphite caps showed no differences.

  6. Measurement and comparison of head scatter factor for 7 MV unflattened (FFF) and 6 MV flattened photon beam using indigenously designed columnar mini phantom

    PubMed Central

    Ashokkumar, Sigamani; Nambiraj, Arunai; Sinha, Sujit Nath; Yadav, Girigesh; Raman, Kothanda; Bhushan, Manindra; Thiyagarajan, Rajesh

    2015-01-01

    Aim To measure and compare the head scatter factor for 7 MV unflattened and 6 MV flattened photon beam using a home-made designed mini phantom. Background The head scatter factor (Sc) is one of the important parameters for MU calculation. There are multiple factors that influence the Sc values, like accelerator head, flattening filter, primary and secondary collimators. Materials and methods A columnar mini phantom was designed as recommended by AAPM Task Group 74 with high and low atomic number material for measurement of head scatter factors at 10 cm and dmax dose water equivalent thickness. Results The Sc values measured with high-Z are higher than the low-Z mini phantoms observed for both 6MV-FB and 7MV-UFB photon energies. Sc values of 7MV-UFB photon beams were smaller than those of the 6MV-FB photon beams (0.6–2.2% (Primus), 0.2–1.4% (Artiste) and 0.6–3.7% (Clinac iX (2300CD))) for field sizes ranging from 10 cm × 10 cm to 40 cm × 40 cm. The SSD had no influence on head scatter for both flattened and unflattened beams. The presence of wedge filters influences the Sc values. The collimator exchange effects showed that the opening of the upper jaw increases Sc irrespective of FF and FFF. Conclusions There were significant differences in Sc values measured for 6MV-FB and unflattened 7MV-UFB photon beams over the range of field sizes from 10 cm × 10 cm to 40 cm × 04 cm. Different results were obtained for measurements performed with low-Z and high-Z mini phantoms. PMID:25949220

  7. Comparison of Head Scatter Factor for 6MV and 10MV flattened (FB) and Unflattened (FFF) Photon Beam using indigenously Designed Columnar Mini Phantom

    PubMed Central

    Ashokkumar, Sigamani; Nambi Raj, N Arunai; Sinha, Sujit Nath; Yadav, Girigesh; Thiyagarajan, Rajesh; Raman, Kothanda; Mishra, Manindra Bhushan

    2014-01-01

    To measure and compare the head scatter factor for flattened (FB) and unflattened (FFF) of 6MV and 10MV photon beam using indigenously designed mini phantom. A columnar mini phantom was designed as recommended by AAPM Task Group 74 with low and high atomic number materials at 10 cm (mini phantom) and at approximately twice the depth of maximum dose water equivalent thickness (brass build-up cap). Scatter in the accelerator (Sc) values of 6MV-FFF photon beams are lesser than that of the 6MV-FB photon beams (0.66-2.8%; Clinac iX, 2300CD) and (0.47-1.74%; True beam) for field sizes ranging from 10 × 10 cm2 to 40 × 40 cm2. Sc values of 10MV-FFF photon beams are lesser (0.61-2.19%; True beam) than that of the 10MV-FB photons beams for field sizes ranging from 10 × 10 cm2 to 40 × 40 cm2. The SSD had no influence on head scatter for both flattened and unflattened beams and irrespective of head design of the different linear accelerators. The presence of field shaping device influences the Sc values. The collimator exchange effect reveals that the opening of the upper jaw increases Sc irrespective of FB or FFF photon beams and different linear accelerators, and it is less significant in FFF beams. Sc values of 6MV-FB square field were in good agreement with that of AAPM, TG-74 published data for Varian (Clinac iX, 2300CD) accelerator. Our results confirm that the removal of flattening filter decreases in the head scatter factor compared to flattened beam. This could reduce the out-of-field dose in advanced treatment delivery techniques. PMID:25190997

  8. Comparison of Head Scatter Factor for 6MV and 10MV flattened (FB) and Unflattened (FFF) Photon Beam using indigenously Designed Columnar Mini Phantom.

    PubMed

    Ashokkumar, Sigamani; Nambi Raj, N Arunai; Sinha, Sujit Nath; Yadav, Girigesh; Thiyagarajan, Rajesh; Raman, Kothanda; Mishra, Manindra Bhushan

    2014-07-01

    To measure and compare the head scatter factor for flattened (FB) and unflattened (FFF) of 6MV and 10MV photon beam using indigenously designed mini phantom. A columnar mini phantom was designed as recommended by AAPM Task Group 74 with low and high atomic number materials at 10 cm (mini phantom) and at approximately twice the depth of maximum dose water equivalent thickness (brass build-up cap). Scatter in the accelerator (Sc) values of 6MV-FFF photon beams are lesser than that of the 6MV-FB photon beams (0.66-2.8%; Clinac iX, 2300CD) and (0.47-1.74%; True beam) for field sizes ranging from 10 × 10 cm(2) to 40 × 40 cm(2). Sc values of 10MV-FFF photon beams are lesser (0.61-2.19%; True beam) than that of the 10MV-FB photons beams for field sizes ranging from 10 × 10 cm(2) to 40 × 40 cm(2). The SSD had no influence on head scatter for both flattened and unflattened beams and irrespective of head design of the different linear accelerators. The presence of field shaping device influences the Sc values. The collimator exchange effect reveals that the opening of the upper jaw increases Sc irrespective of FB or FFF photon beams and different linear accelerators, and it is less significant in FFF beams. Sc values of 6MV-FB square field were in good agreement with that of AAPM, TG-74 published data for Varian (Clinac iX, 2300CD) accelerator. Our results confirm that the removal of flattening filter decreases in the head scatter factor compared to flattened beam. This could reduce the out-of-field dose in advanced treatment delivery techniques.

  9. Residue-based scattering factors.

    PubMed

    Xu, Hongliang

    2016-11-01

    A glob is defined as a group of atoms in the crystal which can be chosen in various ways. Globs themselves can be used as scattering elements in the theory of structure determination, just as atoms are used at present. In this paper, amino-acid residues are chosen to form globs and empirical formulas for residue-based scattering factors have been developed.

  10. [Prognostic factors in head injuries].

    PubMed

    Muñoz-Céspedes, J M; Paúl Laprediza, N M; Pelegrín-Valero, C; Tirapu-Ustarroz, J

    Establishment of the prognosis after traumatic brain damage is an important question for doctors, patients and their families, as well as for health organizations and insurers. The precision of the prognosis varies markedly according to the final objective of the prediction (mortality, severity and type of residual defects, return to work), apart from consideration of the many factors which may affect the clinical course after this type of lesion. Our study considers the current state of this question. We consider the main methodological difficulties in carrying out such studies and review the main variables affecting the prognosis in head injuries, divided into three general groups (severity and type of lesion, characteristics of the individual and variables depending on the context). Finally, we make general comments on the effect of multidisciplinary rehabilitation in relation to the functional prognosis and level of social and employment integration attained by the injured persons.

  11. Efficiency factors in Mie scattering

    NASA Astrophysics Data System (ADS)

    Nussenzveig, H. M.; Wiscombe, W. J.

    1980-11-01

    Asymptotic approximations to the Mie efficiency factors for extinction, absorption and radiation pressure are obtained and compared with the exact results. The approximations are derived from the complex-angular-momentum theory of Mie scattering and averaged oxygen ranges of the size parameter (the product of the wave number and the droplet radius) of approximately pi. The accuracy of the approximation with respect to the exact results is found to increase with increasing values of the size parameter and the real component of the refractive index, resulting in relative errors from 1-10% at a size parameter of 10 and from 0.01-0.001% at a size factor of 1000. Computing time with respect to exact computations is also found to be reduced by a factor on the order of the size parameter. It is thus concluded that the Mie formula can advantageously be replaced by the asymptotic ones in most applications.

  12. Scatter factor corrections for elongated fields.

    PubMed

    Higgins, P D; Sohn, W H; Sibata, C H; McCarthy, W A

    1989-01-01

    Measurements have been made to determine scatter factor corrections for elongated fields of Cobalt-60 and for nominal linear accelerator energies of 6 MV (Siemens Mevatron 67) and 18 MV (AECL Therac 20). It was found that for every energy the collimator scatter factor varies by 2% or more as the field length-to-width ratio increases beyond 3:1. The phantom scatter factor is independent of which collimator pair is elongated at these energies. For 18 MV photons it was found that the collimator scatter factor is complicated by field-size-dependent backscatter into the beam monitor.

  13. Scatter factor corrections for elongated fields

    SciTech Connect

    Higgins, P.D.; Sohn, W.H.; Sibata, C.H.; McCarthy, W.A. )

    1989-09-01

    Measurements have been made to determine scatter factor corrections for elongated fields of Cobalt-60 and for nominal linear accelerator energies of 6 MV (Siemens Mevatron 67) and 18 MV (AECL Therac 20). It was found that for every energy the collimator scatter factor varies by 2% or more as the field length-to-width ratio increases beyond 3:1. The phantom scatter factor is independent of which collimator pair is elongated at these energies. For 18 MV photons it was found that the collimator scatter factor is complicated by field-size-dependent backscatter into the beam monitor.

  14. Scatter factor and reliability of aircraft structures

    NASA Technical Reports Server (NTRS)

    Schueller, G. I.; Freudenthal, A. M.

    1972-01-01

    The concept of time to first failure is utilized to perform a parameter study of scatter factors of aircraft structures. The Weibull distribution is used for estimation of characteristic and certifiable lives. Scatter factors for various Weibull-shaped parameters, fleet sizes and level of reliabilities are calculated. It is concluded that the currently used range of scatter factors (2 through 4) is too narrow for the estimation of a safe life and that a safe and economical design for structural materials with shape parameters less than 2 does not seem feasible except for very small fleet sizes and low levels of reliability.

  15. Scatter factors assessment in microbeam radiation therapy

    SciTech Connect

    Prezado, Y.; Martinez-Rovira, I.; Sanchez, M.

    2012-03-15

    Purpose: The success of the preclinical studies in Microbeam Radiation Therapy (MRT) paved the way to the clinical trials under preparation at the Biomedical Beamline of the European Synchrotron Radiation Facility. Within this framework, an accurate determination of the deposited dose is crucial. With that aim, the scatter factors, which translate the absolute dose measured in reference conditions (2 x 2 cm{sup 2} field size at 2 cm-depth in water) to peak doses, were assessed. Methods: Monte Carlo (MC) simulations were performed with two different widely used codes, PENELOPE and GEANT4, for the sake of safety. The scatter factors were obtained as the ratio of the doses that are deposited by a microbeam and by a field of reference size, at the reference depth. The calculated values were compared with the experimental data obtained by radiochromic (ISP HD-810) films and a PTW 34070 large area chamber. Results: The scatter factors for different microbeam field sizes assessed by the two MC codes were in agreement and reproduced the experimental data within uncertainty bars. Those correction factors were shown to be non-negligible for the future MRT clinical settings: an average 30% lower dose was deposited by a 50 {mu}m microbeam with respect to the reference conditions. Conclusions: For the first time, the scatter factors in MRT were systematically studied. They constitute an essential key to deposit accurate doses in the forthcoming clinical trials in MRT. The good agreement between the different calculations and the experimental data confirms the reliability of this challenging micrometric dose estimation.

  16. Diffuse X-ray scatter from myosin heads in oriented synthetic filaments.

    PubMed Central

    Poulsen, F R; Lowy, J; Cooke, P H; Bartels, E M; Elliott, G F; Hughes, R A

    1987-01-01

    X-ray results are presented concerning the structural state of myosin heads of synthetic filaments in threads. These were made from purified rabbit skeletal muscle myosin and studied by x-ray diffraction and electron microscopy by Cooke et al. (Cooke, P. H., E. M. Bartels, G. F. Elliott, and R. A. Hughes, 1987, Biophys. J., 51:947-957). X-ray patterns show a meridional peak at a spacing of 14.4 nm. We concentrate here on the only other feature of the axial pattern: this is a central region of diffuse scatter, which we find to be similar to that obtained from myosin heads in solution (Mendelson, R. A., K. M. Kretzschmar, 1980, Biochemistry, 19:4103-4108). This means that the myosin heads have very large random displacements in all directions from their average positions, and that they are practically randomly oriented. The myosin heads do not contribute to the 14.4-nm peak, which must come entirely from the backbone. Comparison with x-ray data from the unstriated Taenia coli muscle of the guinea pig indicates that in this muscle at least 75% of the diffuse scatter comes from disordered myosin heads. The results confirm that the diffuse scatter in x-ray patterns from specimens that contain myosin filaments can yield information about the structural behavior of the myosin heads. Images FIGURE 1 PMID:3607214

  17. Scatter factor induces blood vessel formation in vivo.

    PubMed Central

    Grant, D S; Kleinman, H K; Goldberg, I D; Bhargava, M M; Nickoloff, B J; Kinsella, J L; Polverini, P; Rosen, E M

    1993-01-01

    Scatter factor (also known as hepatocyte growth factor) is a glycoprotein secreted by stromal cells that stimulates cell motility and proliferation. In vitro, scatter factor stimulates vascular endothelial cell migration, proliferation, and organization into capillary-like tubes. Using two different in vivo assays, we showed that physiologic quantities of purified native mouse scatter factor and recombinant human hepatocyte growth factor induce angiogenesis (the formation of new blood vessels). The angiogenic activity was blocked by specific anti-scatter factor antibodies. Scatter factor induced cultured microvascular endothelial cells to accumulate and secrete significantly increased quantities of urokinase, an enzyme associated with development of an invasive endothelial phenotype during angiogenesis. We further showed that immunoreactive scatter factor is present surrounding sites of blood vessel formation in psoriatic skin. These findings suggest that scatter factor may act as a paracrine mediator in pathologic angiogenesis associated with human inflammatory disease. Images Fig. 1 Fig. 2 Fig. 3 Fig. 5 PMID:7680481

  18. Scatter Factor Induces Blood Vessel Formation in vivo

    NASA Astrophysics Data System (ADS)

    Grant, Derrick S.; Kleinman, Hynda K.; Goldberg, Itzhak D.; Bhargava, Mahdu M.; Nickoloff, Brian J.; Kinsella, James L.; Polverini, Peter; Rosen, Eliot M.

    1993-03-01

    Scatter factor (also known as hepatocyte growth factor) is a glycoprotein secreted by stromal cells that stimulates cell motility and proliferation. In vitro, scatter factor stimulates vascular endothelial cell migration, proliferation, and organization into capillary-like tubes. Using two different in vivo assays, we showed that physiologic quantities of purified native mouse scatter factor and recombinant human hepatocyte growth factor induce angiogenesis (the formation of new blood vessels). The angiogenic activity was blocked by specific anti-scatter factor antibodies. Scatter factor induced cultured microvascular endothelial cells to accumulate and secrete significantly increased quantities of urokinase, an enzyme associated with development of an invasive endothelial phenotype during angiogenesis. We further showed that immunoreactive scatter factor is present surrounding sites of blood vessel formation in psoriatic skin. These findings suggest that scatter factor may act as a paracrine mediator in pathologic angiogenesis associated with human inflammatory disease.

  19. Coherent Raman Scattering Microscopy for Evaluation of Head and Neck Carcinoma.

    PubMed

    Hoesli, Rebecca C; Orringer, Daniel A; McHugh, Jonathan B; Spector, Matthew E

    2017-09-01

    Objective We aim to describe a novel, label-free, real-time imaging technique, coherent Raman scattering (CRS) microscopy, for histopathological evaluation of head and neck cancer. We evaluated the ability of CRS microscopy to delineate between tumor and nonneoplastic tissue in tissue samples from patients with head and neck cancer. Study Design Prospective case series. Setting Tertiary care medical center. Subjects and Methods Patients eligible were surgical candidates with biopsy-proven, previously untreated head and neck carcinoma and were consented preoperatively for participation in this study. Tissue was collected from 50 patients, and after confirmation of tumor and normal specimens by hematoxylin and eosin (H&E), there were 42 tumor samples and 42 normal adjacent controls. Results There were 42 confirmed carcinoma specimens on H&E, and CRS microscopy identified 37 as carcinoma. Of the 42 normal specimens, CRS microscopy identified 40 as normal. This resulted in a sensitivity of 88.1% and specificity of 95.2% in distinguishing between neoplastic and nonneoplastic images. Conclusion CRS microscopy is a unique label-free imaging technique that can provide rapid, high-resolution images and can accurately determine the presence of head and neck carcinoma. This holds potential for implementation into standard practice, allowing frozen margin evaluation even at institutions without a histopathology laboratory.

  20. Improved scatter correction with factor analysis for planar and SPECT imaging

    NASA Astrophysics Data System (ADS)

    Knoll, Peter; Rahmim, Arman; Gültekin, Selma; Šámal, Martin; Ljungberg, Michael; Mirzaei, Siroos; Segars, Paul; Szczupak, Boguslaw

    2017-09-01

    Quantitative nuclear medicine imaging is an increasingly important frontier. In order to achieve quantitative imaging, various interactions of photons with matter have to be modeled and compensated. Although correction for photon attenuation has been addressed by including x-ray CT scans (accurate), correction for Compton scatter remains an open issue. The inclusion of scattered photons within the energy window used for planar or SPECT data acquisition decreases the contrast of the image. While a number of methods for scatter correction have been proposed in the past, in this work, we propose and assess a novel, user-independent framework applying factor analysis (FA). Extensive Monte Carlo simulations for planar and tomographic imaging were performed using the SIMIND software. Furthermore, planar acquisition of two Petri dishes filled with 99mTc solutions and a Jaszczak phantom study (Data Spectrum Corporation, Durham, NC, USA) using a dual head gamma camera were performed. In order to use FA for scatter correction, we subdivided the applied energy window into a number of sub-windows, serving as input data. FA results in two factor images (photo-peak, scatter) and two corresponding factor curves (energy spectra). Planar and tomographic Jaszczak phantom gamma camera measurements were recorded. The tomographic data (simulations and measurements) were processed for each angular position resulting in a photo-peak and a scatter data set. The reconstructed transaxial slices of the Jaszczak phantom were quantified using an ImageJ plugin. The data obtained by FA showed good agreement with the energy spectra, photo-peak, and scatter images obtained in all Monte Carlo simulated data sets. For comparison, the standard dual-energy window (DEW) approach was additionally applied for scatter correction. FA in comparison with the DEW method results in significant improvements in image accuracy for both planar and tomographic data sets. FA can be used as a user

  1. Scatter estimation and removal of anti-scatter grid-line artifacts from anthropomorphic head phantom images taken with a high resolution image detector.

    PubMed

    Rana, R; Jain, A; Shankar, A; Bednarek, D R; Rudin, S

    2016-02-27

    In radiography, one of the best methods to eliminate image-degrading scatter radiation is the use of anti-scatter grids. However, with high-resolution dynamic imaging detectors, stationary anti-scatter grids can leave grid-line shadows and moiré patterns on the image, depending upon the line density of the grid and the sampling frequency of the x-ray detector. Such artifacts degrade the image quality and may mask small but important details such as small vessels and interventional device features. Appearance of these artifacts becomes increasingly severe as the detector spatial resolution is improved. We have previously demonstrated that, to remove these artifacts by dividing out a reference grid image, one must first subtract the residual scatter that penetrates the grid; however, for objects with anatomic structure, scatter varies throughout the FOV and a spatially differing amount of scatter must be subtracted. In this study, a standard stationary Smit-Rontgen X-ray grid (line density - 70 lines/cm, grid ratio - 13:1) was used with a high-resolution CMOS detector, the Dexela 1207 (pixel size - 75 micron) to image anthropomorphic head phantoms. For a 15 × 15cm FOV, scatter profiles of the anthropomorphic head phantoms were estimated then iteratively modified to minimize the structured noise due to the varying grid-line artifacts across the FOV. Images of the anthropomorphic head phantoms taken with the grid, before and after the corrections, were compared demonstrating almost total elimination of the artifact over the full FOV. Hence, with proper computational tools, anti-scatter grid artifacts can be corrected, even during dynamic sequences.

  2. Scatter estimation and removal of anti-scatter grid-line artifacts from anthropomorphic head phantom images taken with a high resolution image detector

    PubMed Central

    Rana, R.; Jain, A.; Shankar, A.; Bednarek, D.R.; Rudin, S.

    2017-01-01

    In radiography, one of the best methods to eliminate image-degrading scatter radiation is the use of anti-scatter grids. However, with high-resolution dynamic imaging detectors, stationary anti-scatter grids can leave grid-line shadows and moiré patterns on the image, depending upon the line density of the grid and the sampling frequency of the x-ray detector. Such artifacts degrade the image quality and may mask small but important details such as small vessels and interventional device features. Appearance of these artifacts becomes increasingly severe as the detector spatial resolution is improved. We have previously demonstrated that, to remove these artifacts by dividing out a reference grid image, one must first subtract the residual scatter that penetrates the grid; however, for objects with anatomic structure, scatter varies throughout the FOV and a spatially differing amount of scatter must be subtracted. In this study, a standard stationary Smit-Rontgen X-ray grid (line density - 70 lines/cm, grid ratio - 13:1) was used with a high-resolution CMOS detector, the Dexela 1207 (pixel size - 75 micron) to image anthropomorphic head phantoms. For a 15 × 15cm FOV, scatter profiles of the anthropomorphic head phantoms were estimated then iteratively modified to minimize the structured noise due to the varying grid-line artifacts across the FOV. Images of the anthropomorphic head phantoms taken with the grid, before and after the corrections, were compared demonstrating almost total elimination of the artifact over the full FOV. Hence, with proper computational tools, anti-scatter grid artifacts can be corrected, even during dynamic sequences. PMID:28649162

  3. Scatter and attenuation correction for brain SPECT using attenuation distributions inferred from a head atlas.

    PubMed

    Stodilka, R Z; Kemp, B J; Prato, F S; Kertesz, A; Kuhl, D; Nicholson, R L

    2000-09-01

    Sequential transmission scanning (TS)/SPECT is impractical for neurologically impaired patients who are unable to keep their heads motionless for the extended duration of the combined scans. To provide an alternative to TS, we have developed a method of inferring-attenuation distributions (IADs), from SPECT data, using a head atlas and a registration program. The validity of replacing TS with IAD was tested in 10 patients with mild dementia. TS was conducted with each patient using a collimated 99mTc line source and fanbeam collimator; this was followed by hexamethyl propyleneamine oxime-SPECT. IAD was derived by deformably registering the brain component of a digital head atlas to a preliminary SPECT reconstruction and then applying the resulting spatial transformation to the full head atlas. SPECT data were reconstructed with scatter and attenuation correction. Relative regional cerebral blood flow was quantified in 12 threshold-guided anatomic regions of interest, with cerebellar normalization. SPECT reconstructions using IAD were compared with those using TS (which is the "gold standard") in terms of these regions of interest. When we compared all regions of interest across the population, the correlation between IAD-guided and TS-guided SPECT scans was 0.92 (P < 0.0001), whereas the mean absolute difference between the scans was 7.5%. On average, IAD resulted in slight underestimation of relative regional cerebral blood flow; however, this underestimation was statistically significant for only the left frontal and left central sulcus regions (P = 0.001 and 0.002, respectively). Error analysis indicated that approximately 10.0% of the total error was caused by IAD scatter correction, 36.6% was caused by IAD attenuation correction, 27.0% was caused by discrepancies in region-of-interest demarcation from quantitative errors in IAD-guided reconstructions, and 26.5% was caused by patient motion throughout the imaging procedure. SPECT reconstructions guided by IAD

  4. Trust my face: cognitive factors of head fakes in sports.

    PubMed

    Kunde, Wilfried; Skirde, Stefanie; Weigelt, Matthias

    2011-06-01

    In many competitive sports, players try to deceive their opponents about their behavioral intentions by using specific body movements or postures called fakes. For example, fakes are performed in basketball when a player gazes in one direction but passes or shoots the ball in another direction to avert efficient defense actions. The present study aimed to identify the cognitive processes that underlie the effects of fakes. The paradigmatic situation studied was the head fake in basketball. Observers (basketball novices) had to decide as quickly as possible whether a basketball player would pass a ball to the left or to the right. The player's head and gaze were oriented in the direction of an intended pass or in the opposite direction (i.e., a head fake). Responding was delayed for incongruent compared to congruent directions of the player's gaze and the pass. This head fake effect was independent of response speed, the presence of a fake in the immediately preceding trial, and practice with the task. Five further experiments using additive-factors logic and locus-of-slack logic revealed a perceptual rather than motor-related origin of this effect: Turning the head in a direction opposite the pass direction appears to hamper the perceptual encoding of pass direction, although it does not induce a tendency to move in the direction of the head's orientation. The implications of these results for research on deception in sports and their relevance for sports practice are discussed.

  5. Scatter estimation and removal of anti-scatter grid-line artifacts from anthropomorphic head phantom images taken with a high resolution image detector

    NASA Astrophysics Data System (ADS)

    Rana, R.; Jain, A.; Shankar, A.; Bednarek, D. R.; Rudin, S.

    2016-03-01

    In radiography, one of the best methods to eliminate image-degrading scatter radiation is the use of anti-scatter grids. However, with high-resolution dynamic imaging detectors, stationary anti-scatter grids can leave grid-line shadows and moiré patterns on the image, depending upon the line density of the grid and the sampling frequency of the x-ray detector. Such artifacts degrade the image quality and may mask small but important details such as small vessels and interventional device features. Appearance of these artifacts becomes increasingly severe as the detector spatial resolution is improved. We have previously demonstrated that, to remove these artifacts by dividing out a reference grid image, one must first subtract the residual scatter that penetrates the grid; however, for objects with anatomic structure, scatter varies throughout the FOV and a spatially differing amount of scatter must be subtracted. In this study, a standard stationary Smit-Rontgen X-ray grid (line density - 70 lines/cm, grid ratio - 13:1) was used with a high-resolution CMOS detector, the Dexela 1207 (pixel size - 75 micron) to image anthropomorphic head phantoms. For a 15 x 15cm FOV, scatter profiles of the anthropomorphic head phantoms were estimated then iteratively modified to minimize the structured noise due to the varying grid-line artifacts across the FOV. Images of the anthropomorphic head phantoms taken with the grid, before and after the corrections, were compared demonstrating almost total elimination of the artifact over the full FOV. Hence, with proper computational tools, antiscatter grid artifacts can be corrected, even during dynamic sequences.

  6. The separation of the head and phantom scatter components from a phase space description.

    PubMed

    Sanz, Darío Esteban; Nelli, Flavio Enrico

    2004-09-21

    The formalism based on phantom and collimator scatter factors for high energy photon beams is deduced using a phase space description. The phantom scatter factors (Sp) depend on the field size and shape at the level of the phantom and are generally considered independent of the collimation details used to form the desired field provided the effect of contaminant electrons can be neglected. As demonstrated in this work, this behaviour leads to the applicability of the Clarkson method in irregular fields. However, for a given field formed with a tertiary collimator it is not a priori clear that the variations of extrafocal radiation due to secondary collimator setting do not affect the phantom scatter correction factors. In fact, the extrafocal radiation has a lower mean energy than that of unscattered photons, and this radiation can reach points well outside the radiation field increasing the irradiated phantom volume. Besides, transmission through the blocks contributes to phantom scatter. Therefore, for a given block-defined field, the associated phantom scatter dose, per unit of fluence in air on the central axis, should in principle increase when enlarging the secondary collimator field. To confirm this, isocentric Sp data for 6 MV photons were measured at 10 cm depth in water, reducing with cerrobend blocks several fields formed with the secondary collimators. In particular, when a 30 x 30 cm2 collimator field is reduced with blocks to a 7 x 7 cm2 field, the dose per unit of fluence in air is 1.4% higher than that of the square collimator field equating the given block field. Our calculations indicate that in this case the block transmission accounts for only 0.2% of this increment, showing that the remaining effect is due to extrafocal radiation. As a concluding remark, this work contributes to a better understanding of the classical Clarkson method for irregular fields giving, additionally, a formal interpretation of the commonly used quantities.

  7. [Prognostic factors about morbidity and lethality in head injury].

    PubMed

    Melo, José Roberto Tude; Oliveira Filho, Jamary; da Silva, Ricardo Araújo; Moreira Júnior, Edson Duarte

    2005-12-01

    To define the prognostic factors in head injury victims. Assessment and notification of 555 medical files from victims with head injury assisted at the General Hospital of Bahia during 2001. We verified morbidity rates of 19.6% and lethality rates of 22.9%, with most deaths occurring in men after the third decade of life; the injuries involved traffic accidents that were responsible for 64 (50.4%) deaths. Older age, traffic accidents and fever were predictors of death in the multivariable analysis. Fever was the only significant predictor of morbidity. Fever is an independent and modifiable predictor of death and morbidity in patients with traumatic brain injury.

  8. X-Ray Form Factor, Attenuation and Scattering Tables

    National Institute of Standards and Technology Data Gateway

    SRD 66 X-Ray Form Factor, Attenuation and Scattering Tables (Web, free access)   This database collects tables and graphs of the form factors, the photoabsorption cross section, and the total attenuation coefficient for any element (Z <= 92).

  9. Determination of light absorption, scattering and anisotropy factor of a highly scattering medium using backscattered circularly polarized light

    NASA Astrophysics Data System (ADS)

    Xu, M.; Alrubaiee, M.; Gayen, S. K.; Alfano, R. R.

    2007-02-01

    The absorption coefficient, the scattering coefficient and the anisotropy factor of a highly scattering medium are determined using the diffuse reflectance of an obliquely incident beam of circularly polarized light. This approach determines both the anisotropy factor and the cutoff size parameter for the fractal continuous scattering medium such as biological tissue and tissue phantoms from depolarization of the backscattered light.

  10. On the factorization and fitting of molecular scattering information

    NASA Technical Reports Server (NTRS)

    Goldflam, R.; Kouri, D. J.; Green, S.

    1977-01-01

    The reported analysis is based on the factored IOS T-matrix. It is shown that line shape measurements may be used over a range of temperatures to evaluate inelastic scattering cross sections. Basic factorization or parameterization relations are derived by considering the wavefunction equations. The parameterization of cross sections is considered, taking into account the differential scattering amplitude and cross section, integral cross sections, phenomenological cross sections for general relaxation processes, and viscosity and diffusion cross sections. Thermal averages and rates are discussed, giving attention to integral cross sections and rates, and general phenomenological cross sections. The results of computational studies are also presented.

  11. An effective field theory for forward scattering and factorization violation

    DOE PAGES

    Rothstein, Ira Z.; Stewart, Iain W.

    2016-08-03

    Starting with QCD, we derive an effective field theory description for forward scattering and factorization violation as part of the soft-collinear effective field theory (SCET) for high energy scattering. These phenomena are mediated by long distance Glauber gluon exchanges, which are static in time, localized in the longitudinal distance, and act as a kernel for forward scattering where |t| << s. In hard scattering, Glauber gluons can induce corrections which invalidate factorization. With SCET, Glauber exchange graphs can be calculated explicitly, and are distinct from graphs involving soft, collinear, or ultrasoft gluons. We derive a complete basis of operators whichmore » describe the leading power effects of Glauber exchange. Key ingredients include regulating light-cone rapidity singularities and subtractions which prevent double counting. Our results include a novel all orders gauge invariant pure glue soft operator which appears between two collinear rapidity sectors. The 1-gluon Feynman rule for the soft operator coincides with the Lipatov vertex, but it also contributes to emissions with ≥ 2 soft gluons. Our Glauber operator basis is derived using tree level and one-loop matching calculations from full QCD to both SCETII and SCETI. The one-loop amplitude’s rapidity renormalization involves mixing of color octet operators and yields gluon Reggeization at the amplitude level. The rapidity renormalization group equation for the leading soft and collinear functions in the forward scattering cross section are each given by the BFKL equation. Various properties of Glauber gluon exchange in the context of both forward scattering and hard scattering factorization are described. For example, we derive an explicit rule for when eikonalization is valid, and provide a direct connection to the picture of multiple Wilson lines crossing a shockwave. In hard scattering operators Glauber subtractions for soft and collinear loop diagrams ensure that we are not

  12. An effective field theory for forward scattering and factorization violation

    SciTech Connect

    Rothstein, Ira Z.; Stewart, Iain W.

    2016-08-03

    Starting with QCD, we derive an effective field theory description for forward scattering and factorization violation as part of the soft-collinear effective field theory (SCET) for high energy scattering. These phenomena are mediated by long distance Glauber gluon exchanges, which are static in time, localized in the longitudinal distance, and act as a kernel for forward scattering where |t| << s. In hard scattering, Glauber gluons can induce corrections which invalidate factorization. With SCET, Glauber exchange graphs can be calculated explicitly, and are distinct from graphs involving soft, collinear, or ultrasoft gluons. We derive a complete basis of operators which describe the leading power effects of Glauber exchange. Key ingredients include regulating light-cone rapidity singularities and subtractions which prevent double counting. Our results include a novel all orders gauge invariant pure glue soft operator which appears between two collinear rapidity sectors. The 1-gluon Feynman rule for the soft operator coincides with the Lipatov vertex, but it also contributes to emissions with ≥ 2 soft gluons. Our Glauber operator basis is derived using tree level and one-loop matching calculations from full QCD to both SCETII and SCETI. The one-loop amplitude’s rapidity renormalization involves mixing of color octet operators and yields gluon Reggeization at the amplitude level. The rapidity renormalization group equation for the leading soft and collinear functions in the forward scattering cross section are each given by the BFKL equation. Various properties of Glauber gluon exchange in the context of both forward scattering and hard scattering factorization are described. For example, we derive an explicit rule for when eikonalization is valid, and provide a direct connection to the picture of multiple Wilson lines crossing a shockwave. In hard scattering operators Glauber subtractions for soft and collinear loop diagrams ensure that we

  13. An effective field theory for forward scattering and factorization violation

    NASA Astrophysics Data System (ADS)

    Rothstein, Ira Z.; Stewart, Iain W.

    2016-08-01

    Starting with QCD, we derive an effective field theory description for forward scattering and factorization violation as part of the soft-collinear effective field theory (SCET) for high energy scattering. These phenomena are mediated by long distance Glauber gluon exchanges, which are static in time, localized in the longitudinal distance, and act as a kernel for forward scattering where | t| ≪ s. In hard scattering, Glauber gluons can induce corrections which invalidate factorization. With SCET, Glauber exchange graphs can be calculated explicitly, and are distinct from graphs involving soft, collinear, or ultrasoft gluons. We derive a complete basis of operators which describe the leading power effects of Glauber exchange. Key ingredients include regulating light-cone rapidity singularities and subtractions which prevent double counting. Our results include a novel all orders gauge invariant pure glue soft operator which appears between two collinear rapidity sectors. The 1-gluon Feynman rule for the soft operator coincides with the Lipatov vertex, but it also contributes to emissions with ≥ 2 soft gluons. Our Glauber operator basis is derived using tree level and one-loop matching calculations from full QCD to both SCETII and SCETI. The one-loop amplitude's rapidity renormalization involves mixing of color octet operators and yields gluon Reggeization at the amplitude level. The rapidity renormalization group equation for the leading soft and collinear functions in the forward scattering cross section are each given by the BFKL equation. Various properties of Glauber gluon exchange in the context of both forward scattering and hard scattering factorization are described. For example, we derive an explicit rule for when eikonalization is valid, and provide a direct connection to the picture of multiple Wilson lines crossing a shockwave. In hard scattering operators Glauber subtractions for soft and collinear loop diagrams ensure that we are not sensitive to

  14. Analytical evaluation of atomic form factors: Application to Rayleigh scattering

    SciTech Connect

    Safari, L.; Santos, J. P.; Amaro, P.; Jänkälä, K.; Fratini, F.

    2015-05-15

    Atomic form factors are widely used for the characterization of targets and specimens, from crystallography to biology. By using recent mathematical results, here we derive an analytical expression for the atomic form factor within the independent particle model constructed from nonrelativistic screened hydrogenic wave functions. The range of validity of this analytical expression is checked by comparing the analytically obtained form factors with the ones obtained within the Hartee-Fock method. As an example, we apply our analytical expression for the atomic form factor to evaluate the differential cross section for Rayleigh scattering off neutral atoms.

  15. Analytical evaluation of atomic form factors: Application to Rayleigh scattering

    NASA Astrophysics Data System (ADS)

    Safari, L.; Santos, J. P.; Amaro, P.; Jänkälä, K.; Fratini, F.

    2015-05-01

    Atomic form factors are widely used for the characterization of targets and specimens, from crystallography to biology. By using recent mathematical results, here we derive an analytical expression for the atomic form factor within the independent particle model constructed from nonrelativistic screened hydrogenic wave functions. The range of validity of this analytical expression is checked by comparing the analytically obtained form factors with the ones obtained within the Hartee-Fock method. As an example, we apply our analytical expression for the atomic form factor to evaluate the differential cross section for Rayleigh scattering off neutral atoms.

  16. Examining Protective Factors and Risk Factors in Urban and Rural Head Start Preschoolers

    ERIC Educational Resources Information Center

    Bender, Stacy L.; Fedor, Megan C.; Carlson, John S.

    2011-01-01

    This study examined a comprehensive screening model within children attending Head Start programs from urban (n = 232) and rural (n = 231) communities. The Devereux Early Childhood Assessment (DECA; LeBuffe & Naglieri, 1999) was used to measure social-emotional protective factors (i.e., Total Protective Factors [TPF]) and risk factors (i.e.,…

  17. Examining Protective Factors and Risk Factors in Urban and Rural Head Start Preschoolers

    ERIC Educational Resources Information Center

    Bender, Stacy L.; Fedor, Megan C.; Carlson, John S.

    2011-01-01

    This study examined a comprehensive screening model within children attending Head Start programs from urban (n = 232) and rural (n = 231) communities. The Devereux Early Childhood Assessment (DECA; LeBuffe & Naglieri, 1999) was used to measure social-emotional protective factors (i.e., Total Protective Factors [TPF]) and risk factors (i.e.,…

  18. Environmental and Genetic Factors Explain Differences in Intraocular Scattering.

    PubMed

    Benito, Antonio; Hervella, Lucía; Tabernero, Juan; Pennos, Alexandros; Ginis, Harilaos; Sánchez-Romera, Juan F; Ordoñana, Juan R; Ruiz-Sánchez, Marcos; Marín, José M; Artal, Pablo

    2016-01-01

    To study the relative impact of genetic and environmental factors on the variability of intraocular scattering within a classical twin study. A total of 64 twin pairs, 32 monozygotic (MZ) (mean age: 54.9 ± 6.3 years) and 32 dizygotic (DZ) (mean age: 56.4 ± 7.0 years), were measured after a complete ophthalmologic exam had been performed to exclude all ocular pathologies that increase intraocular scatter as cataracts. Intraocular scattering was evaluated by using two different techniques based on a straylight parameter log(S) estimation: a compact optical instrument based in the principle of optical integration and a psychophysical measurement. Intraclass correlation coefficients (ICC) were used as descriptive statistics of twin resemblance, and genetic models were fitted to estimate heritability. No statistically significant difference was found for MZ and DZ groups for age (P = 0.203), best-corrected visual acuity (P = 0.626), cataract gradation (P = 0.701), sex (P = 0.941), optical log(S) (P = 0.386), or psychophysical log(S) (P = 0.568), with only a minor difference in equivalent sphere (P = 0.008). Intraclass correlation coefficients between siblings were similar for scatter parameters: 0.676 in MZ and 0.471 in DZ twins for optical log(S); 0.533 in MZ twins and 0.475 in DZ twins for psychophysical log(S). For equivalent sphere, ICCs were 0.767 in MZ and 0.228 in DZ twins. Conservative estimates of heritability for the measured scattering parameters were 0.39 and 0.20, respectively. Correlations of intraocular scatter (straylight) parameters in the groups of identical and nonidentical twins were similar. Heritability estimates were of limited magnitude, suggesting that genetic and environmental factors determine the variance of ocular straylight in healthy middle-aged adults.

  19. Closure and Sensitivity Study of Scattering Enhancement Factor

    NASA Astrophysics Data System (ADS)

    Zhang, L.

    2016-12-01

    Scattering of solar radiation by aerosol particles is highly dependent on relative humidity (RH) as hygroscopic particles take up water with increasing RH. To achieve a better understanding of the effect of aerosol hygroscopic growth on light scattering properties and analyze the possible influence factors, the aerosol scattering coefficients at RH in the range of <40 to 90% were measured using a humidified nephelometer system in the Yangtze River Delta of China in March 2013. In addition, the aerosol size distribution and chemical composition were measured. During the observation period, the mean and standard deviation (SD) of enhancement factors at RH=85% for the scattering coefficient (f(85%)), backscattering coefficient (fb(85%)) and hemispheric backscatter fraction (fp(85%)) were 1.58±0.12, 1.25±0.07 and 0.79±0.04, respectively. The implementation of ISORROPIA II to predict f(RH) was achived. A log-normal distribution has been assumed to analyze the influence of particle number size distribution (PNSD) to f(RH). The result shows that number concentrations do not affect f(RH), f(RH) decreases with the increase of geometric mean diameter (Dp) and standard deviation (σ). Usually, the influence of pnsd on f(RH) mainly depend on the shape of the accumulation mode. Chemical compositions influences f(RH) by two ways: refractive index (n) and growth factor (g). f(RH) decreases with the increase of n. Thus, for organics, its influence on f(RH) has dual sides: increasing f(RH) by decreasing n and decreasing f(RH) by decreasing g. For BC, as a hydrophobic composition with large n, the effect is completely decrease.

  20. On empirical methods to determine scatter factors for irregular MLC shaped beams.

    PubMed

    Georg, Dietmar; Olofsson, Jörgen; Künzler, Thomas; Karlsson, Mikael

    2004-08-01

    Multileaf collimators (MLCs) are in clinical use for more than a decade and are a well accepted tool in radiotherapy. For almost each MLC design different empirical or semianalytical methods have been presented for calculating output ratios in air for irregularly shaped beams. However, until now no clear recommendations have been given on how to handle irregular fields shaped by multileaf collimators for independent monitor unit (MU) verification. The present article compares different empirical methods, which have been proposed for independent MU verification, to determine (1) output ratios in air (Sc) and (2) phantom scatter factors (Sp) for irregular MLC shaped fields. Ten dedicated field shapes were applied to five different types of MLCs (Elekta, Siemens, Varian, Scanditronix, General Electric). All calculations based on empirical relations were compared with measurements and with calculations performed by a treatment planning system with a fluence based algorithm. For most irregular MLC shaped beams output ratios in air could be adequately modeled with an accuracy of about 1%-1.5% applying a method based on the open field aperture defined by the leaf and jaw setting combined with the equivalent square formula suggested by Vadash and Bjärngard [P. Vadash and B. E. Bjärngard, Med. Phys. 20, 733-734 (1993)]. The accuracy of this approach strongly depends on the inherent head scatter characteristics of the accelerator in use and on the irregular field under consideration. Deviations of up to 3% were obtained for fields where leaves obscure central parts of the flattening filter. Simple equivalent square methods for Sp calculations in irregular fields did not provide acceptable results (deviations mostly >3%). Sp values derived from Clarkson integration, based on published tables of phantom scatter correction factors, showed the same accuracy level as calculations performed using a pencil beam algorithm of a treatment planning system (in a homogeneous media

  1. Collagen microstructural factors influencing optic nerve head biomechanics.

    PubMed

    Zhang, Liang; Albon, Julie; Jones, Hannah; Gouget, Cecile L M; Ethier, C Ross; Goh, James C H; Girard, Michaël J A

    2015-03-03

    Previous studies have suggested that the lamina cribrosa (LC) and its surrounding sclera are biomechanically important in the pathogenesis of glaucoma, but many were limited by assumptions of tissue isotropy and homogeneity. Here, we used an improved biomechanical model driven by experimental measurements of scleral and LC collagen fiber organization to more accurately evaluate optic nerve head (ONH) biomechanics. Collagen fiber organization was quantitatively mapped across human ONH cryosections (three normal and three glaucomatous) using small-angle light scattering (SALS) and fed into two-dimensional finite element models loaded under biaxial stress to simulate raised intraocular pressure. Effects of artificial variations in collagen fiber microstructure and stiffness on LC and scleral strains were also investigated. Scleral collagen fibers were circumferential and exhibited the highest alignment in a region not immediately adjacent to, but at a distance (400-500 μm) away from, the LC. In models, such a fiber arrangement yielded rings of low strain (second principal and effective) in the scleral region immediately adjacent to the LC. Further sensitivity analyses showed that scleral fiber alignment was crucial in determining LC strain levels. Moderate scleral anisotropy (as observed physiologically) was more effective than isotropy or high anisotropy in limiting LC and scleral strain magnitude. The presence of a heterogeneous collagen fiber organization in the peripapillary sclera appears effective in limiting LC strain and is able to reduce strain levels at the scleral canal boundary: a transition zone prone to LC disinsertion, focal lamina cribrosa defects, and optic disc hemorrhages in glaucoma. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

  2. Head and neck sarcomas: prognostic factors and implications for treatment.

    PubMed Central

    Eeles, R. A.; Fisher, C.; A'Hern, R. P.; Robinson, M.; Rhys-Evans, P.; Henk, J. M.; Archer, D.; Harmer, C. L.

    1993-01-01

    One hundred and thirty patients with soft tissue sarcoma of the head and neck were treated at the Royal Marsden Hospital between 1944 and 1988. Pathological review was possible in 103 of these cases; only pathologically reviewed cases have been analysed. The median age at presentation was 36 years, and 53% were male. Four had neurofibromatosis type I, and one previous bilateral retinoblastoma. Six had undergone previous radiotherapy, 12 to 45 years prior to developing sarcoma. The tumours were < or = 5 cm in 78% of cases and high grade in 48%. Only one patient presented with lymph node metastases and only one with distant metastases (to lung). Malignant fibrous histiocytoma was the commonest histological type, occurring in 30 cases. The overall 5 year survival was 50% (95% CI 39-60). Local tumour was the cause of death in 63% of cases and 5 year local control was only 47% (95% CI 36-58) with local recurrence occurring as late as 15 years after treatment. The only favourable independent prognostic factor for survival was the ability to perform surgery (other than biopsy), with or without radiotherapy, as opposed to radiotherapy alone (hazard ratio 0.39; P = 0.003). Only one patient had a biopsy with no further treatment. Favourable independent prognostic factors for local control at 5 years were site (tumours of the head as opposed to the neck, hazard ratio 0.42; P = 0.02) and modality of treatment (combined surgery and radiotherapy compared to either alone, hazard ratio 0.31; P = 0.002). Patients in the combined modality and single treatment modality groups were well balanced for T stage, grade and tumour site. The patients in the combined treatment group had less extensive surgery, yet their local recurrence-free survival was longer. Unlike soft tissue sarcomas at other sites, those in the head and neck region more often cause death by local recurrence. The addition of radiotherapy to surgery may result in longer local recurrence-free survival. PMID:8318414

  3. Multiple Scattering Debye-Waller Factors for Arsenate

    NASA Astrophysics Data System (ADS)

    Kim, E.; Chen, N.; Arthur, Z.; Warner, J.; Demopoulos, G. P.; Rowson, J. W.; Jiang, D. T.

    2013-04-01

    Debye-Waller factors for the As-O-O triangular multiple scattering paths within the arsenate in Na2HAsO4·7H2O are evaluated in terms of magnitude ratio with respect to the Debye-Waller factor of the nearest neighbour As-O shell (σ2As-0-0/σ2As-0). The arsenates are studied under two different levels of distortion from an ideal tetrahedron, i.e. a relatively high distortion in the powder form and a nearly ideal tetrahedron in an aqueous solution at pH 14. The Debye-Waller factor ratio σ2As-0-0/σ2As-0) is found to be 2.0 and 1.9 for the powder and liquid sample, respectively, appearing to be insensitive to the distortion of the arsenate tetrahedron.

  4. SU-E-T-08: A Convolution Model for Head Scatter Fluence in the Intensity Modulated Field

    SciTech Connect

    Chen, M; Mo, X; Chen, Y; Parnell, D; Key, S; Olivera, G; Galmarini, W; Lu, W

    2014-06-01

    Purpose: To efficiently calculate the head scatter fluence for an arbitrary intensity-modulated field with any source distribution using the source occlusion model. Method: The source occlusion model with focal and extra focal radiation (Jaffray et al, 1993) can be used to account for LINAC head scatter. In the model, the fluence map of any field shape at any point can be calculated via integration of the source distribution within the visible range, as confined by each segment, using the detector eye's view. A 2D integration would be required for each segment and each fluence plane point, which is time-consuming, as an intensity-modulated field contains typically tens to hundreds of segments. In this work, we prove that the superposition of the segmental integrations is equivalent to a simple convolution regardless of what the source distribution is. In fact, for each point, the detector eye's view of the field shape can be represented as a function with the origin defined at the point's pinhole reflection through the center of the collimator plane. We were thus able to reduce hundreds of source plane integration to one convolution. We calculated the fluence map for various 3D and IMRT beams and various extra-focal source distributions using both the segmental integration approach and the convolution approach and compared the computation time and fluence map results of both approaches. Results: The fluence maps calculated using the convolution approach were the same as those calculated using the segmental approach, except for rounding errors (<0.1%). While it took considerably longer time to calculate all segmental integrations, the fluence map calculation using the convolution approach took only ∼1/3 of the time for typical IMRT fields with ∼100 segments. Conclusions: The convolution approach for head scatter fluence calculation is fast and accurate and can be used to enhance the online process.

  5. SU-E-I-55: The Contribution to Skin Dose Due to Scatter From the Patient Table and the Head Holder During Fluoroscopy

    SciTech Connect

    Islam, N; Xiong, Z; Vijayan, S; Rudin, S; Bednarek, D

    2015-06-15

    Purpose: To determine contributions to skin dose due to scatter from the table and head holder used during fluoroscopy, and also to explore alternative design material to reduce the scatter dose. Methods: Measurements were made of the primary and scatter components of the xray beam exiting the patient table and a cylindrical head holder used on a Toshiba Infinix c-arm unit as a function of kVp for the various beam filters on the machine and for various field sizes. The primary component of the beam was measured in air with the object placed close to the x-ray tube with an air gap between it and a 6 cc parallel-plate ionization chamber and with the beam collimated to a size just larger than the chamber. The primary plus scatter radiation components were measured with the object moved to a position in the beam next to the chamber for larger field sizes. Both sets of measurements were preformed while keeping the source-to-chamber distance fixed. The scatter fraction was estimated by taking the ratio of the difference between the two measurements and the reading that included both primary and scatter. Similar measurements were also made for a 2.3 cm thick Styrofoam block which could substitute for the patient support. Results: The measured scatter fractions indicate that the patient table as well as the head holder contributes an additional 10–16% to the patient entrance dose depending on field size. Forward scatter was reduced with the Styrofoam block so that the scatter fraction was about 4–5%. Conclusion: The results of this investigation demonstrated that scatter from the table and head holder used in clinical fluoroscopy contribute substantially to the skin dose. The lower contribution of scatter from Styrofoam suggests that there is an opportunity to redesign patient support accessories to reduce the skin dose. Partial support from NIH grant R01EB002873 and Toshiba Medical Systems Corporation Equipment Grant.

  6. Longitudinal electron scattering form factors for 54,56Fe

    NASA Astrophysics Data System (ADS)

    Salman, A. D.; Kadhim, D. R.

    2014-09-01

    In this paper, inelastic longitudinal electron scattering form factors for C2 transition have been studied in 54Fe and 56Fe with the aid of shell model calculations. The GX1 effective interaction for the fp-shell is used with the nucleon-nucleon realistic interaction Michigan three-range Yukawa and Modified surface delta interaction as a two-body interactions. The core polarization effects is taken into account through the first-order perturbation theory with the effective charge, which is taken to the proton and the neutron. The effective charge along with the core effects up to 6 ℏw enhanced the calculation very well and improving good agreement with the experimental data.

  7. Frequency mismatch in stimulated scattering processes: An important factor for the transverse distribution of scattered light

    SciTech Connect

    Gong, Tao; Zheng, Jian; Li, Zhichao; Yang, Dong; Ding, Yongkun; Hu, Guangyue; Zhao, Bin

    2016-06-15

    A 2D cylindrically symmetric model with inclusion of both diffraction and self-focus effects is developed to deal with the stimulated scattering processes of a single hotspot. The calculated results show that the transverse distribution of the scattered light is sensitive to the longitudinal profiles of the plasma parameters. The analysis of the evolution of the scattered light indicates that it is the frequency mismatch of coupling due to the inhomogeneity of plasmas that determines the transverse distribution of the scattered light.

  8. Prevalence and associated factors of head lice infestation among primary schoolchildren in Kelantan, Malaysia.

    PubMed

    Bachok, Norsa'adah; Nordin, Rusli Bin; Awang, Che Wil; Ibrahim, Noor Aini; Naing, Lin

    2006-05-01

    Head lice infestation contributes a significant morbidity among schoolchildren in Malaysia. A cross-sectional study was designed to determine the prevalence and associated factors of head lice infestation among primary schoolchildren in Kelantan, Malaysia. Six schools were randomly selected from three sub-districts of Kuala Krai, Kelantan. A total of 463 eleven-year-old pupils were screened by visual scalp examination and fine-toothed combing. Self-administered questionnaire was used to collect data on socio-demography and associated factors of head lice infestation. The prevalence of head lice infestation was 35.0% (95% Cl: 30.6, 39.3) with 11.9% inactive, 23.1% active, 18.2% light and 16.8% heavy infestations. The associated factors were girls; family income of RM247 or less; head lice infestation of family member and having four or more siblings. The high prevalence of head lice infestation in this study indicates the need for regular school health program that emphasis on the eradication of head lice. The significant associated factors identified in this study reconfirm the importance of controlling the transmissibility of head lice. Pupils and parents should be informed regarding factors that may facilitate the transmission of head lice.

  9. Strange vector form factors from parity-violating electron scattering

    SciTech Connect

    Kent Paschke, Anthony Thomas, Robert Michaels, David Armstrong

    2011-06-01

    The simplest models might describe the nucleon as 3 light quarks, but this description would be incomplete without inclusion of the sea of glue and qbar q pairs which binds it. Early indications of a particularly large contribution from strange quarks in this sea to the spin and mass of the nucleon motivated an experimental program examining the role of these strange quarks in the nucleon vector form factors. The strangeness form factors can be extracted from the well-studied electromagnetic structure of the nucleon using parity-violation in electron-nuclear scattering to isolate the effect of the weak interaction. With high luminosity and polarization, and a very stable beam due to its superconducting RF cavities, CEBAF at Jefferson Lab is a precision instrument uniquely well suited to the challenge of measurements of the small parity-violating asymmetries. The techniques and results of the two major Jefferson Lab experimental efforts in parity-violation studies, HAPPEX and G0, as well as efforts to describe the strange form factors in QCD, will be reviewed.

  10. Characterisation of hydraulic head changes and aquifer properties in the London Basin using Persistent Scatterer Interferometry ground motion data

    NASA Astrophysics Data System (ADS)

    Bonì, R.; Cigna, F.; Bricker, S.; Meisina, C.; McCormack, H.

    2016-09-01

    In this paper, Persistent Scatterer Interferometry was applied to ERS-1/2 and ENVISAT satellite data covering 1992-2000 and 2002-2010 respectively, to analyse the relationship between ground motion and hydraulic head changes in the London Basin, United Kingdom. The integration of observed groundwater levels provided by the Environment Agency and satellite-derived displacement time series allowed the estimation of the spatio-temporal variations of the Chalk aquifer storage coefficient and compressibility over an area of ∼1360 km2. The average storage coefficient of the aquifer reaches values of 1 × 10-3 and the estimated average aquifer compressibility is 7.7 × 10-10 Pa-1 and 1.2 × 10-9 Pa-1 for the periods 1992-2000 and 2002-2010, respectively. Derived storage coefficient values appear to be correlated with the hydrogeological setting, where confined by the London Clay the storage coefficient is typically an order of magnitude lower than where the chalk is overlain by the Lambeth Group. PSI-derived storage coefficient estimates agree with the values obtained from pumping tests in the same area. A simplified one-dimensional model is applied to simulate the ground motion response to hydraulic heads changes at nine piezometers. The comparison between simulated and satellite-observed ground motion changes reveals good agreement, with errors ranging between 1.4 and 6.9 mm, and being 3.2 mm on average.

  11. Ranking Medical Subject Headings using a factor graph model.

    PubMed

    Wei, Wei; Demner-Fushman, Dina; Wang, Shuang; Jiang, Xiaoqian; Ohno-Machado, Lucila

    2015-01-01

    Automatically assigning MeSH (Medical Subject Headings) to articles is an active research topic. Recent work demonstrated the feasibility of improving the existing automated Medical Text Indexer (MTI) system, developed at the National Library of Medicine (NLM). Encouraged by this work, we propose a novel data-driven approach that uses semantic distances in the MeSH ontology for automated MeSH assignment. Specifically, we developed a graphical model to propagate belief through a citation network to provide robust MeSH main heading (MH) recommendation. Our preliminary results indicate that this approach can reach high Mean Average Precision (MAP) in some scenarios.

  12. Socioeconomic status, family background and other key factors influence the management of head lice in Norway.

    PubMed

    Rukke, Bjørn Arne; Soleng, Arnulf; Lindstedt, Heidi Heggen; Ottesen, Preben; Birkemoe, Tone

    2014-05-01

    How head lice infestations are managed by households is an important but generally neglected issue in head lice research. In the present study, we investigate actions taken against head lice by Norwegian households in association with socioeconomic status, family background, school-related variables and other key factors. Repeat questionnaires distributed to caretakers of the same elementary school children during a 2-year period enabled us to study both previous head lice management and any changes in this management through time. Households from 12 schools spanning the main socioeconomic variation found in Norway participated in the study. All students with active head lice infestation were treated in the four investigated periods. Most caretakers used a thorough head lice checking technique and informed others of own infestation. Checking frequency was low as most children were inspected less than monthly. The best determinant of increased checking frequency and thoroughness was personal experience with head lice. The increased awareness, however, seemed to be somewhat short-lived, as there was a decrease in checking frequency and thoroughness within 1 year after infestation. Personal experience with head lice also increased general knowledge related to the parasite. Parents born in developing countries checked their children for head lice more frequently, although less thoroughly, informed fewer contacts when infested, used pediculicides preventively more often and knew less about head lice than parents born in developed countries. Households with highly educated mothers had a lower checking frequency, but their knowledge and willingness to inform others was high. Single parents were more concerned about economic costs and kept children home from school longer while infested than other parents. As head lice management varied among socioeconomic groups and with parental background, differentiated advice should be considered in the control of head lice. The

  13. Electromagnetic Form Factors of the Nucleon and Compton Scattering

    SciTech Connect

    Charles Hyde-Wright; Cornelis De Jager

    2004-12-01

    We review the experimental and theoretical status of elastic electron scattering and elastic low-energy photon scattering (with both real and virtual photons) from the nucleon. As a consequence of new experimental facilities and new theoretical insights, these subjects are advancing with unprecedented precision. These reactions provide many important insights into the spatial distributions and correlations of quarks in the nucleon.

  14. Total scatter factors of small beams: A multidetector and Monte Carlo study

    SciTech Connect

    Francescon, Paolo; Cora, Stefania; Cavedon, Carlo

    2008-02-15

    The scope of this study was to estimate total scatter factors (s{sub c,p}) of the three smallest collimators of the Cyberknife radiosurgery system (5-10 mm in diameter), combining experimental measurements and Monte Carlo simulation. Two microchambers, a diode, and a diamond detector were used to collect experimental data. The treatment head and the detectors were simulated by means of a Monte Carlo code in order to calculate correction factors for the detectors and to estimate total scatter factors by means of a consistency check between measurement and simulation. Results for the three collimators were: s{sub c,p}(5 mm)=0.677{+-}0.004, s{sub c,p}(7.5 mm)=0.820{+-}0.008, s{sub c,p}(10 mm)=0.871{+-}0.008, all relative to the 60 mm collimator at 80 cm source-to-detector distance. The method also allows the full width at half maximum of the electron beam to be estimated; estimations made with different collimators and different detectors were in excellent agreement and gave a value of 2.1 mm. Correction factors to be applied to the detectors for the measurement of s{sub c,p} were consistent with a prevalence of volume effect for the microchambers and the diamond and a prevalence of scattering from high-Z material for the diode detector. The proposed method is more sensitive to small variations of the electron beam diameter with respect to the conventional method used to commission Monte Carlo codes, i.e., by comparison with measured percentage depth doses (PDD) and beam profiles. This is especially important for small fields (less than 10 mm diameter), for which measurements of PDD and profiles are strongly affected by the type of detector used. Moreover, this method should allow s{sub c,p} of Cyberknife systems different from the unit under investigation to be estimated without the need for further Monte Carlo calculation, provided that one of the microchambers or the diode detector of the type used in this study are employed. The results for the diamond are

  15. Environmental and Physiological Factors Affect Football Head Impact Biomechanics.

    PubMed

    Mihalik, Jason P; Sumrall, Adam Z; Yeargin, Susan W; Guskiewicz, Kevin M; King, Kevin B; Trulock, Scott C; Shields, Edgar W

    2017-10-01

    Recent anecdotal trends suggest a disproportionate number of head injuries in collegiate football players occur during preseason football camp. In warmer climates, this season also represents the highest risk for heat-related illness among collegiate football players. Because concussion and heat illnesses share many common symptoms, we need 1) to understand if environmental conditions, body temperature, and hydration status affect head impact biomechanics; and 2) to determine if an in-helmet thermistor could provide a valid measure of gastrointestinal temperature. A prospective cohort of 18 Division I college football players (age, 21.1 ± 1.4 yr; height, 187.7 ± 6.6 cm; mass, 114.5 ± 23.4 kg). Data were collected during one control and three experimental sessions. During each session, the Head Impact Telemetry System recorded head impact biomechanics (linear acceleration, rotational acceleration, and severity profile) and in-helmet temperature. A wet bulb globe device recorded environmental conditions, and CorTemp™ Ingestible Core Body Temperature Sensors recorded gastrointestinal temperature. Our findings suggest that linear acceleration (P = 0.57), rotational acceleration (P = 0.16), and Head Impact Technology severity profile (P = 0.33) are not influenced by environmental or physiological conditions. We did not find any single or combination of predictors for impact severity. Rotational acceleration was approaching significance between our early experimental sessions when compared with our control session. More research should be conducted to better understand if rotational accelerations are a component of impact magnitudes that are affected due to changes in environmental conditions, body temperature, and hydration status.

  16. An Analytical Method to Calculate Phantom Scatter Factor for Photon Beam Accelerators

    PubMed Central

    Birgani, Mohammad Javad Tahmasebi; Chegeni, Nahid; Behrooz, Mohammad Ali; Bagheri, Marziyeh; Danyaei, Amir; Shamsi, Azin

    2017-01-01

    Introduction One of the important input factors in the commissioning of the radiotherapy treatment planning systems is the phantom scatter factor (Sp) which requires the same collimator opening for all radiation fields. In this study, we have proposed an analytical method to overcome this issue. Methods The measurements were performed using Siemens Primus Plus with photon energy 6 MV for field sizes from 5×5cm2 to 40×40cm2. Phantom scatter factor was measured through the division of total scatter output factors (Scp), and collimator scatter factor (Sc). Results The mean percent difference between the measured and calculated Sp was 1.00% and -3.11% for 5×5, 40×40 cm2 field size respectively. Conclusion This method is applicable especially for small fields used in IMRT which, measuring collimator scatter factor is not reliable due to the lateral electron disequilibrium. PMID:28243402

  17. Robustness of the fractal regime for the multiple-scattering structure factor

    NASA Astrophysics Data System (ADS)

    Katyal, Nisha; Botet, Robert; Puri, Sanjay

    2016-08-01

    In the single-scattering theory of electromagnetic radiation, the fractal regime is a definite range in the photon momentum-transfer q, which is characterized by the scaling-law behavior of the structure factor: S(q) ∝ 1 /q df. This allows a straightforward estimation of the fractal dimension df of aggregates in Small-Angle X-ray Scattering (SAXS) experiments. However, this behavior is not commonly studied in optical scattering experiments because of the lack of information on its domain of validity. In the present work, we propose a definition of the multiple-scattering structure factor, which naturally generalizes the single-scattering function S(q). We show that the mean-field theory of electromagnetic scattering provides an explicit condition to interpret the significance of multiple scattering. In this paper, we investigate and discuss electromagnetic scattering by three classes of fractal aggregates. The results obtained from the TMatrix method show that the fractal scaling range is divided into two domains: (1) a genuine fractal regime, which is robust; (2) a possible anomalous scaling regime, S(q) ∝ 1 /qδ, with exponent δ independent of df, and related to the way the scattering mechanism uses the local morphology of the scatterer. The recognition, and an analysis, of the latter domain is of importance because it may result in significant reduction of the fractal regime, and brings into question the proper mechanism in the build-up of multiple-scattering.

  18. Estimating head and neck tissue dose from x-ray scatter to physicians performing x-ray guided cardiovascular procedures: a phantom study.

    PubMed

    Fetterly, Kenneth A; Schueler, Beth A; Grams, Michael P; Sturchio, Glenn M

    2017-03-20

    Physicians performing x-ray guided interventional procedures have a keen interest in radiation safety. Radiation dose to tissues and organs of the head and neck are of particular interest because they are not routinely protected by wearable radiation safety devices. This study was conducted to facilitate estimation of radiation dose to tissues of the head and neck of interventional physicians based on the dose recorded by a personal dosimeter worn on the left collar. Scatter beam qualities maximum energy and HVL were measured for 40 scatter beams emitting from an anthropomorphic patient phantom. Variables of the scatter beams included scatter angle (35° and 90°), primary beam peak tube potential (60, 80, 100, and 120 kVp), and 5 Cu spectral filter thicknesses (0-0.9 mm). Four reference scatter beam qualities were selected to represent the range of scatter beams realized in a typical practice. A general radiographic x-ray tube was tuned to produce scatter-equivalent radiographic beams and used to simultaneously expose the head and neck of an anthropomorphic operator phantom and radiochromic film. The geometric relationship between the x-ray source of the scatter-equivalent beams and the operator phantom was set to mimic that between a patient and physician performing an invasive cardiovascular procedure. Dose to the exterior surface of the operator phantom was measured with both 3 × 3 cm(2) pieces of film and personal dosimeters positioned at the location of the left collar. All films were scanned with a calibrated flatbed scanner, which converted the film's reflective density to dose. Films from the transverse planes of the operator phantom provided 2D maps of the dose distribution within the phantom. These dose maps were normalized by the dose at the left collar, providing 2D percent of left collar dose (LCD) maps. The percent LCD maps were overlain with bony anatomy CT images of the operator phantom and estimates of percent LCD to the left, right and whole

  19. General equation for the differential pathlength factor of the frontal human head depending on wavelength and age.

    PubMed

    Scholkmann, Felix; Wolf, Martin

    2013-10-01

    Continuous-wave near-infrared spectroscopy and near-infrared imaging enable the measurement of relative concentration changes in oxy- and deoxyhemoglobin and thus hemodynamics and oxygenation. The accuracy of determined changes depends mainly on the modeling of the light transport through the probed tissue. Due to the highly scattering nature of tissue, the light path is longer than the source-detector separation (d). This is incorporated in modeling by multiplying d by a differential pathlength factor (DPF) which depends on several factors such as wavelength, age of the subject, and type of tissue. In the present work, we derive a general DPF equation for the frontal human head, incorporating dependency on wavelength and age, based on published data. We validated the equation using different data sets of experimentally determined DPFs from six independent studies.

  20. Factors Influencing Helmet Use, Head Injury, and Hospitalization Among Children Involved in Skateboarding and Snowboarding Accidents.

    PubMed

    Sadeghian, Homa; Nguyen, Brian; Huynh, Nhan; Rouch, Joshua; Lee, Steven L; Bazargan-Hejazi, Shahrzad

    2017-01-01

    Up to 75% of skateboarders and snowboarders admitted to the hospital sustain head injuries. It is unclear why not all children and teenagers wear helmets while snowboarding and skateboarding given the protection they afford. To report on the prevalence of, and factors associated with, skateboarding and snowboarding in injured children and to explore factors that influence helmet use, head injury, and hospitalization in this sample. A cross-sectional study of skateboard- and snowboard-associated injuries from 2003 to 2012 among individuals younger than age 18 years using National Electronic Injury Surveillance System (NEISS) data from approximately 100 hospitals. Helmet use, head injury, and hospitalization. Of 1742 patients in the study, 852 (48.9%) and 890 (51.1%) were skateboarders and snowboarders, respectively. Overall, 907 (52.1%) did not use helmets, and 704 (40.4%) sustained head injuries. Multiple logistic regression analysis showed that age, race/ethnicity, location of boarding, and engaging in skateboarding influenced helmet use. Sex, race/ethnicity, helmet use, and skateboarding predicted head injury. Age, sex, skateboarding, and head injury predicted hospital admission. Statistically significant differences exist in helmet use, head injury, and hospitalization rates between skateboarders and snowboarders. Our findings suggest that injury prevention and outreach programs are needed to increase helmet use and reduce the risk of head injury and hospitalization in skateboarders and other at-risk groups. Further studies are needed to clarify the association between race/ethnicity and helmet use among skateboarders and snowboarders.

  1. Scatter factor binds to thrombospondin and other extracellular matrix components.

    PubMed Central

    Lamszus, K.; Joseph, A.; Jin, L.; Yao, Y.; Chowdhury, S.; Fuchs, A.; Polverini, P. J.; Goldberg, I. D.; Rosen, E. M.

    1996-01-01

    Scatter factor (SF) is an angiogenic growth factor that stimulates motility and invasion of carcinoma cells. SF is present in the extracellular matrix (ECM) of breast cancers, where it might act to promote tumor cell invasion and angiogenesis. To investigate how SF is incorporated into the ECM, we studied the binding of SF to various ECM components using a solid-phase binding assay based on the SF enzyme-linked immunosorbent assay. We found that SF binds to a variety of ECM molecules, with different binding capacities. The highest SF binding capacities were observed for thrombospondin-1 (TSP-1), fibronectin (Fn), and heparan sulfate proteoglycan, although SF did not bind to albumin. Mature two-chain SF and precursor single-chain SF bound approximately equally well to TSP-1 and Fn. Moreover, two SF alpha-chain peptides (NK1 and NK2) both bound to TSP-1 and Fn, suggesting that the whole SF molecule is not required for binding. Based on binding competition assays, TSP-1 exhibited higher affinity for SF than did nine other ECM molecules, including Fn and heparan sulfate proteoglycan. Although heparin in solution potently inhibited the binding of SF to TSP-1-coated surfaces, even very high concentrations of heparin could not elute SF already bound to TSP-1. SF binding was modulated by binding interactions among ECM molecules (TSP-1-Fn, TSP-1-collagen I, and Fn-collagen I), suggesting that the matrix capacity to bind SF depends upon its exact composition. SF bound in a dose-dependent fashion to ECMs secreted by three human breast carcinoma cell lines. Binding of SF to matrices from all three cell lines was significantly inhibited by preincubation of the matrices with antibodies against TSP-1, whereas antibodies against several other ECM components were less effective or ineffective in inhibiting SF binding. In addition, TSP-1 markedly inhibited chemotaxis of microvascular endothelial cells toward SF and SF-induced angiogenesis in the rat cornea neovascularization assay

  2. Purification of scatter factor, a fibroblast-derived basic protein that modulates epithelial interactions and movement.

    PubMed Central

    Gherardi, E; Gray, J; Stoker, M; Perryman, M; Furlong, R

    1989-01-01

    Scatter factor is a fibroblast-derived protein that causes separation of contiguous epithelial cells and increased local mobility of unanchored cells. Highly purified scatter factor has been obtained by a combination of ion-exchange and reverse-phase chromatography from serum-free medium conditioned by a ras-transformed clone (D4) of mouse NIH 3T3 fibroblasts. Under nonreducing conditions scatter factor has a pI of approximately 9.5 and migrates in SDS/polyacrylamide gels as a single band at approximately 62 kDa from which epithelial scatter activity can be recovered. Treatment with reducing agents destroys biological activity and is associated with the appearance of two major bands at approximately 57 and approximately 30 kDa. Whether both the 57-kDa and 30-kDa polypeptides are required for biological activity remains to be established. All the activities observed in crude medium conditioned by cells producing scatter factor are retained by highly purified preparations of scatter factor. These include (i) increased local movement, modulation of morphology, and inhibition of junction formation by single epithelial cells and (ii) disruption of epithelial interactions and cell scattering from preformed epithelial sheets. These changes occur with picomolar concentrations of purified scatter factor and without an effect on cell growth. Images PMID:2527367

  3. Analysis of factors affecting birthweight, birth length and head circumference: study of Japanese triplets.

    PubMed

    Yokoyama, Yoshie; Sugimoto, Masako; Ooki, Syuichi

    2005-12-01

    The aims of this study were to identify factors associated with birthweight, birth length and head circumference for triplets, and analyze these body size parameters at birth, especially head circumference, according to gestational age. The subjects of this study were 370 mothers and their 1109 triplet children (excluding one stillborn infant) who were born between 1978 and 2002. The gestational age proved to be the strongest contributing factor to birthweight, birth length and head circumference of the triplets. Moreover, sex was a significant factor affecting birthweight, birth length and head circumference. Male neonates had a higher birthweight, longer birth length and greater head circumference than female neonates. Birth order in triplets also had a significant effect on birthweight and head circumference. Lower birth-order neonates had a higher birthweight and greater head circumference. An effect of maternal pregravid body mass index (BMI) on both birthweight and birth length was observed. The birthweights of triplets born to women whose pregravid BMIs were more than 26.0 kg/m2 weighed an average of 150 g more than those of triplets born to women whose pregravid BMIs were less than 19.8 kg/m2, and the birth length of triplets born to women whose pregravid BMIs were more than 26.0 kg/m2 averaged 1.5 cm longer than those of triplets born to women whose pregravid BMIs were less than 19.8 kg/m2. Concerning head circumference, the median head circumference of male neonates was approximately 0.5 cm longer than female neonates. Compared to singleton neonates, the median head circumference of triplets was almost the same.

  4. A complete comparison of simulated electron diffraction patterns using different parameterizations of the electron scattering factors.

    PubMed

    Lobato, I; Van Dyck, D

    2015-08-01

    The steadily improving experimental possibilities in instrumental resolution as in sensitivity and quantization of the data recording put increasingly higher demands on the precision of the scattering factors, which are the key ingredients for electron diffraction or high-resolution imaging simulation. In the present study, we will systematically investigate the accuracy of fitting of the main parameterizations of the electron scattering factor for the calculation of electron diffraction intensities. It is shown that the main parameterizations of the electron scattering factor are consistent to calculate electron diffraction intensities for thin specimens and low angle scattering. Parameterizations of the electron scattering factor with the correct asymptotic behavior (Lobato and Dyck [5], Kirkland [4], and Weickenmeier and Kohl [2]) produce similar results for both the undisplaced lattice model and the frozen phonon model, except for certain thicknesses and reflections.

  5. Comparing the quality of passively-scattered proton and photon tomotherapy plans for brain and head and neck disease sites.

    PubMed

    Kainz, Kristofer; Firat, Selim; Wilson, J Frank; Schultz, Christopher; Siker, Malika; Wang, Andrew; Olson, Dan; Li, X Allen

    2015-03-21

    We compare the quality of photon IMRT (helical tomotherapy) with classic proton plans for brain, head and neck tumors, in terms of target dose uniformity and conformity along with organ-at-risk (OAR) sparing. Plans were created for twelve target volumes among eight cases. All patients were originally planned and treated using helical tomotherapy. Proton plans were generated using a passively-scattered beam model with a maximum range of 32 g cm(-2) (225 MeV), range modulation in 0.5 g cm(-2) increments and range compensators with 4.8 mm milling tool diameters. All proton plans were limited to two to four beams. Plan quality was compared using uniformity index (UI), conformation number (CN) and a EUD-based plan quality index (fEUD). For 11 of the 12 targets, UI was improved for the proton plan; on average, UI was 1.05 for protons versus 1.08 for tomotherapy. For 7 of the 12 targets, the tomotherapy plan exhibited more favorable CN. For proximal OARs, the improved dose conformity to the target volume from tomotherapy led to a lower maximum dose. For distal OARs, the maximum dose was much lower for proton plans. For 6 of the 8 cases, near-total avoidance for distal OARs provided by protons leads to improved fEUD. However, if distal OARs are excluded in the fEUD calculation, the proton plans exhibit better fEUD in only 3 of the 8 cases. The distal OAR sparing and target dose uniformity are generally better with passive-scatter proton planning than with photon tomotherapy; proton therapy may be preferred if the clinician deems those attributes critical. However, tomotherapy may serve equally as well as protons for cases where superior target dose conformity from tomotherapy leads to plan quality nearly identical to or better than protons and for cases where distal OAR sparing is not concerning.

  6. Proper factorization theorems in high-energy scattering near the endpoint

    NASA Astrophysics Data System (ADS)

    Chay, Junegone; Kim, Chul

    2013-09-01

    Consistent factorization theorems in high-energy scattering near the threshold are presented in the framework of the soft-collinear effective theory. Traditional factorization theorem separates the soft and collinear parts successfully, but a final step should be supplemented if each part encounters infrared divergence. We present factorization theorems in which the infrared divergences appear only in the parton distribution functions and the infrared divergence is removed by carefully separating and reorganizing collinear and soft parts. The underlying physical idea is to isolate and remove the soft contributions systematically from the collinear part in loop corrections order by order. After this procedure, each factorized term in the scattering cross sections is free of infrared divergence, and can be safely computed using perturbation theory. This factorization procedure can be applied to various high-energy scattering processes. We show factorization theorems in Drell-Yan processes, deep inelastic scattering and Higgs production near the endpoint.

  7. Hepatocyte growth factor/scatter factor is present in most pleural effusion fluids from cancer patients.

    PubMed Central

    Eagles, G.; Warn, A.; Ball, R. Y.; Baillie-Johnson, H.; Arakaki, N.; Daikuhara, Y.; Warn, R. M.

    1996-01-01

    Pleural effusion samples were obtained from 55 patients with malignant disease, including patients with primary lung cancers and those with a variety of other tumours metastatic to the pleura. The effusions were assayed for the presence of hepatocyte growth factor/scatter factor (HGF/SF), by both ELISA and bioassay. The presence of malignant cells in the effusions was also assessed. Detectable amounts of the factor, as judged by both criteria, were found in over 90% of all the effusions, including those from patients with a wide variety of carcinomas and also lymphomas. A wide range of HGF/SF levels were found for all tumour classes, some effusions containing high levels above 4 ng ml-1. It is concluded that tumours within the pleura and adjacent lung tissue are usually exposed to biologically significant levels of HGF/SF. PMID:8562345

  8. Altered sensory-motor control of the head as an etiological factor in space-motion sickness

    NASA Technical Reports Server (NTRS)

    Lackner, J. R.; DiZio, P.

    1989-01-01

    Mechanical unloading during head movements in weightlessness may be an etiological factor in space-motion sickness. We simulated altered head loading on Earth without affecting vestibular stimulation by having subjects wear a weighted helmet. Eight subjects were exposed to constant velocity rotation about a vertical axis with direction reversals every 60 sec. for eight reversals with the head loaded and eight with the head unloaded. The severity of motion sickness elicited was significantly higher when the head was loaded. This suggests that altered sensory-motor control of the head is also an etiological factor in space-motion sickness.

  9. Altered sensory-motor control of the head as an etiological factor in space-motion sickness

    NASA Technical Reports Server (NTRS)

    Lackner, J. R.; DiZio, P.

    1989-01-01

    Mechanical unloading during head movements in weightlessness may be an etiological factor in space-motion sickness. We simulated altered head loading on Earth without affecting vestibular stimulation by having subjects wear a weighted helmet. Eight subjects were exposed to constant velocity rotation about a vertical axis with direction reversals every 60 sec. for eight reversals with the head loaded and eight with the head unloaded. The severity of motion sickness elicited was significantly higher when the head was loaded. This suggests that altered sensory-motor control of the head is also an etiological factor in space-motion sickness.

  10. Factors associated with small head circumference at birth among infants born before the 28th week

    PubMed Central

    McElrath, Thomas F.; Allred, Elizabeth N.; Kuban, Karl; Hecht, Jonathan L.; Onderdonk, Andrew; O’Shea, T. Michael; Paneth, Nigel; Leviton, Alan

    2010-01-01

    OBJECTIVE We sought to identify risk factors for congenital microcephaly in extremely low gestational age newborns. STUDY DESIGN Demographic, clinical, and placental characteristics of 1445 infants born before the 28th week were gathered and evaluated for their relationship with congenital microcephaly. RESULTS Almost 10% of newborns (n = 138), rather than the expected 2.2%, had microcephaly defined as a head circumference >2 SD below the median. In multivariable models, microcephaly was associated with nonwhite race, severe intrauterine growth restriction, delivery for preeclampsia, placental infarction, and being female. The risk factors for a head circumference between <1 and >2 SD below the median were similar to those of microcephaly. CONCLUSION Characteristics associated with fetal growth restriction and preeclampsia are among the strongest correlates of microcephaly among children born at extremely low gestational ages. The elevated risk of a small head among nonwhites and females might reflect the lack of appropriate head circumference standards. PMID:20541727

  11. Scattering from phase-separated vesicles. I. An analytical form factor for multiple static domains

    SciTech Connect

    Heberle, Frederick A.; Anghel, Vinicius N. P.; Katsaras, John

    2015-08-18

    This is the first in a series of studies considering elastic scattering from laterally heterogeneous lipid vesicles containing multiple domains. Unique among biophysical tools, small-angle neutron scattering can in principle give detailed information about the size, shape and spatial arrangement of domains. A general theory for scattering from laterally heterogeneous vesicles is presented, and the analytical form factor for static domains with arbitrary spatial configuration is derived, including a simplification for uniformly sized round domains. The validity of the model, including series truncation effects, is assessed by comparison with simulated data obtained from a Monte Carlo method. Several aspects of the analytical solution for scattering intensity are discussed in the context of small-angle neutron scattering data, including the effect of varying domain size and number, as well as solvent contrast. Finally, the analysis indicates that effects of domain formation are most pronounced when the vesicle's average scattering length density matches that of the surrounding solvent.

  12. Factors Involved in Iranian Women Heads of Household's Health Promotion Activities: A Grounded Theory Study.

    PubMed

    Rafii, Forough; Seyedfatemi, Naima; Rezaei, Mahboubeh

    2013-01-01

    We aimed to explore and describe the factors involved in Iranian women heads of household's health promotion activities. Grounded theory was used as the method. Sixteen women heads of household were recruited. Data were generated by semi structured interviews. Our findings indicated that remainder of resources (money, time and energy) alongside perceived severity of health risk were two main factors whereas women's personal and socio-economic characteristics were two contextual factors involved in these women's health promotion activities. To help these women improve their health status, we recommended that the government, non-governmental organizations and health care professionals provide them with required resources and increase their knowledge by holding training sessions.

  13. Impurity scattering rate and coherence factor in vortex core of sign-reversing s -wave superconductors

    NASA Astrophysics Data System (ADS)

    Nagai, Yuki; Kato, Yusuke

    2010-11-01

    We investigate the impurity scattering rates for quasiparticles in vortex cores of sign-reversing s -wave superconductors as a probe to detect the internal phase difference of the order parameters among different Fermi surfaces. The impurity scattering rates and coherence factors are related to quasiparticle interference effect by the scanning tunneling microscopy and spectroscopy technique. With use of the Born and Kramer-Pesch approximations for the Andreev bound states, we show that the sign-reversed forward scatterings are dominant in vortex cores. Owing to the coherence factor in vortex cores of ±s -wave superconductors, the impurity scattering rate of the Andreev bound states has a characteristic distribution on the Fermi surfaces. For comparison, the impurity scattering rates in vortex cores of s -wave and d -wave superconductors are also discussed.

  14. Analysis of risk factors for femoral head necrosis after internal fixation in femoral neck fractures.

    PubMed

    Wang, Tao; Sun, Jun-Ying; Zha, Guo-Chun; Jiang, Tao; You, Zhen-Jun; Yuan, De-Jing

    2014-12-01

    Femoral head necrosis is a rare but devastating complication following femoral neck fracture. The reported incidence of avascular necrosis after femoral neck fracture fixation varies widely, and there is no consensus regarding its risk factors. The aim of this study was to analyze the risk factors for femoral head necrosis after internal fixation in femoral neck fracture. This retrospective study included 166 patients with femoral neck fractures treated with surgical reduction and internal fixation at the authors' institution from January 2004 to December 2008. Eight patients died for reasons unrelated to the surgery, and 12 patients were lost to follow-up. The remaining 146 patients (146 fractures) were followed until union or until conversion to total hip arthroplasty. The patients included 61 males and 85 females with an average age of 47.5 years (range, 18-68 years). The authors analyzed the following factors: age, sex, Garden classification, reduction quality, surgical methods, injury-to-surgery interval, preoperative traction, weight-bearing time, and implant removal. All patients were followed for a mean of 52 months (range, 6-90 months). The incidence of femoral head necrosis was 14.4% (21/146). Garden classification (P=.012), reduction quality (P=.008), implant removal (P=.020), and preoperative traction (P=.003) were significantly associated with femoral head necrosis. Patient age (P=.990), sex (P=.287), injury-to-surgery interval (P=.360), weight-bearing time (P=.868), and surgical methods (P=.987) were not significantly associated with femoral head necrosis. In multivariate logistic regression analysis, implant removal was not a significant risk factor for femoral head necrosis development (P=.498). Garden classification, reduction quality, and preoperative traction had a significant effect on femoral head necrosis development. Copyright 2014, SLACK Incorporated.

  15. Hepatocyte growth factor/scatter factor modulates cell motility, proliferation, and proteoglycan synthesis of chondrocytes.

    PubMed

    Takebayashi, T; Iwamoto, M; Jikko, A; Matsumura, T; Enomoto-Iwamoto, M; Myoukai, F; Koyama, E; Yamaai, T; Matsumoto, K; Nakamura, T

    1995-06-01

    Hepatocyte growth factor/scatter factor (HGF/SF) is a multifunctional growth factor that promotes proliferation, motility, and morphogenesis in epithelial cells. Recently the HGF receptor, c-met protooncogene product, has been shown to be expressed in developing limb buds (Sonnenberg, E., D. Meyer, M. Weidner, and C. Birchmeiyer, 1993. J. Cell Biol. 123: 223-235), suggesting that some populations of mesenchymal cells in limb buds respond to HGF/SF. To test the possibility that HGF/SF is involved in regulation of cartilage development, we isolated chondrocytes from knee joints and costal cartilages of 23-d embryonic and 4-wk-old rabbits, and analyzed the effects of HGF/SF on migration and proliferation of these cells. We found that HGF/SF stimulated migration of cultured articular chondrocytes but did not scatter limb mesenchymal fibroblasts or synovial fibroblasts in culture. HGF/SF also stimulated proliferation of chondrocytes; a maximum three-fold stimulation in DNA synthesis was observed at the concentration of 3 ng/ml of HGF/SF. Moreover, HGF/SF had the ability to enhance proteoglycan synthesis in chondrocytes. The responsiveness of chondrocytes to HGF/SF was also supported by the observation that they expressed the HGF/SF receptor. Addition of the neutralizing antibody to rat HGF/SF affected neither DNA synthesis nor proteoglycan synthesis in rat chondrocytes, suggesting a paracine mechanism of action of HGF/SF on these cells. In situ hybridization analysis showed that HGF/SF mRNA was restrictively expressed in the areas of future joint regions in developing limb buds and in the intercostal spaces of developing costal cartilages. These findings suggest that HGF/SF plays important roles in cartilage development through its multiple activities.

  16. Hepatocyte growth factor/scatter factor modulates cell motility, proliferation, and proteoglycan synthesis of chondrocytes

    PubMed Central

    1995-01-01

    Hepatocyte growth factor/scatter factor (HGF/SF) is a multifunctional growth factor that promotes proliferation, motility, and morphogenesis in epithelial cells. Recently the HGF receptor, c-met protooncogene product, has been shown to be expressed in developing limb buds (Sonnenberg, E., D. Meyer, M. Weidner, and C. Birchmeiyer, 1993. J. Cell Biol. 123: 223-235), suggesting that some populations of mesenchymal cells in limb buds respond to HGF/SF. To test the possibility that HGF/SF is involved in regulation of cartilage development, we isolated chondrocytes from knee joints and costal cartilages of 23-d embryonic and 4-wk-old rabbits, and analyzed the effects of HGF/SF on migration and proliferation of these cells. We found that HGF/SF stimulated migration of cultured articular chondrocytes but did not scatter limb mesenchymal fibroblasts or synovial fibroblasts in culture. HGF/SF also stimulated proliferation of chondrocytes; a maximum three-fold stimulation in DNA synthesis was observed at the concentration of 3 ng/ml of HGF/SF. Moreover, HGF/SF had the ability to enhance proteoglycan synthesis in chondrocytes. The responsiveness of chondrocytes to HGF/SF was also supported by the observation that they expressed the HGF/SF receptor. Addition of the neutralizing antibody to rat HGF/SF affected neither DNA synthesis nor proteoglycan synthesis in rat chondrocytes, suggesting a paracine mechanism of action of HGF/SF on these cells. In situ hybridization analysis showed that HGF/SF mRNA was restrictively expressed in the areas of future joint regions in developing limb buds and in the intercostal spaces of developing costal cartilages. These findings suggest that HGF/SF plays important roles in cartilage development through its multiple activities. PMID:7775584

  17. Influence of length and conformation of saccharide head groups on the mechanics of glycolipid membranes: Unraveled by off-specular neutron scattering

    SciTech Connect

    Yamamoto, Akihisa E-mail: tanaka@uni-heidelberg.de; Tanaka, Motomu E-mail: tanaka@uni-heidelberg.de; Abuillan, Wasim; Körner, Alexander; Burk, Alexandra S.; Ries, Annika; Werz, Daniel B.; Demé, Bruno

    2015-04-21

    The mechanical properties of multilayer stacks of Gb3 glycolipid that play key roles in metabolic disorders (Fabry disease) were determined quantitatively by using specular and off-specular neutron scattering. Because of the geometry of membrane stacks deposited on planar substrates, the scattered intensity profile was analyzed in a 2D reciprocal space map as a function of in-plane and out-of-plane scattering vector components. The two principal mechanical parameters of the membranes, namely, bending rigidity and compression modulus, can be quantified by full calculation of scattering functions with the aid of an effective cut-off radius that takes the finite sample size into consideration. The bulkier “bent” Gb3 trisaccharide group makes the membrane mechanics distinctly different from cylindrical disaccharide (lactose) head groups and shorter “bent” disaccharide (gentiobiose) head groups. The mechanical characterization of membranes enriched with complex glycolipids has high importance in understanding the mechanisms of diseases such as sphingolipidoses caused by the accumulation of non-degenerated glycosphingolipids in lysosomes or inhibition of protein synthesis triggered by the specific binding of Shiga toxin to Gb3.

  18. Influence of length and conformation of saccharide head groups on the mechanics of glycolipid membranes: Unraveled by off-specular neutron scattering

    NASA Astrophysics Data System (ADS)

    Yamamoto, Akihisa; Abuillan, Wasim; Burk, Alexandra S.; Körner, Alexander; Ries, Annika; Werz, Daniel B.; Demé, Bruno; Tanaka, Motomu

    2015-04-01

    The mechanical properties of multilayer stacks of Gb3 glycolipid that play key roles in metabolic disorders (Fabry disease) were determined quantitatively by using specular and off-specular neutron scattering. Because of the geometry of membrane stacks deposited on planar substrates, the scattered intensity profile was analyzed in a 2D reciprocal space map as a function of in-plane and out-of-plane scattering vector components. The two principal mechanical parameters of the membranes, namely, bending rigidity and compression modulus, can be quantified by full calculation of scattering functions with the aid of an effective cut-off radius that takes the finite sample size into consideration. The bulkier "bent" Gb3 trisaccharide group makes the membrane mechanics distinctly different from cylindrical disaccharide (lactose) head groups and shorter "bent" disaccharide (gentiobiose) head groups. The mechanical characterization of membranes enriched with complex glycolipids has high importance in understanding the mechanisms of diseases such as sphingolipidoses caused by the accumulation of non-degenerated glycosphingolipids in lysosomes or inhibition of protein synthesis triggered by the specific binding of Shiga toxin to Gb3.

  19. Factors Influencing Helmet Use, Head Injury, and Hospitalization Among Children Involved in Skateboarding and Snowboarding Accidents

    PubMed Central

    Sadeghian, Homa; Nguyen, Brian; Huynh, Nhan; Rouch, Joshua; Lee, Steven L; Bazargan-Hejazi, Shahrzad

    2017-01-01

    Context Up to 75% of skateboarders and snowboarders admitted to the hospital sustain head injuries. It is unclear why not all children and teenagers wear helmets while snowboarding and skateboarding given the protection they afford. Objectives To report on the prevalence of, and factors associated with, skateboarding and snowboarding in injured children and to explore factors that influence helmet use, head injury, and hospitalization in this sample. Design A cross-sectional study of skateboard- and snowboard-associated injuries from 2003 to 2012 among individuals younger than age 18 years using National Electronic Injury Surveillance System (NEISS) data from approximately 100 hospitals. Main Outcome Measures: Helmet use, head injury, and hospitalization. Results Of 1742 patients in the study, 852 (48.9%) and 890 (51.1%) were skateboarders and snowboarders, respectively. Overall, 907 (52.1%) did not use helmets, and 704 (40.4%) sustained head injuries. Multiple logistic regression analysis showed that age, race/ethnicity, location of boarding, and engaging in skateboarding influenced helmet use. Sex, race/ethnicity, helmet use, and skateboarding predicted head injury. Age, sex, skateboarding, and head injury predicted hospital admission. Conclusion Statistically significant differences exist in helmet use, head injury, and hospitalization rates between skateboarders and snowboarders. Our findings suggest that injury prevention and outreach programs are needed to increase helmet use and reduce the risk of head injury and hospitalization in skateboarders and other at-risk groups. Further studies are needed to clarify the association between race/ethnicity and helmet use among skateboarders and snowboarders. PMID:28406787

  20. A dynamic factor modeling framework for analyzing multiple groundwater head series simultaneously

    NASA Astrophysics Data System (ADS)

    Berendrecht, W. L.; van Geer, F. C.

    2016-05-01

    In this paper we present an approach in which we combine a dynamic factor model (DFM) and predefined response functions to analyze a set of groundwater head series simultaneously. Each groundwater head series is decomposed into: (a) one or more deterministic components as a response to known driving forces, (b) one or more common dynamic factors, representing spatial patterns not related to any of the input series and (c) one specific dynamic factor for each groundwater head series, describing unique variation for that series. The approach reduces the degrees of freedom for each response function, enables the application to irregular observed data, and exploits the correlation between residual series of a set of groundwater head series. The common dynamic factors may be interpreted as spatial patterns due to e.g. limitations in the model specification or concept, spatially correlated errors in input variables, or driving forces which have not been included in the model. In the latter case the model can be applied in the context of an alarming system, e.g. to monitor regional trends. The specific dynamic factor depicts the variation of a particular groundwater head series that cannot be related to any other time series of the set nor to any input series. Therefore the specific dynamic factor is suitable for analyzing local variations and detecting incidental measurement errors, for example in a quality control procedure. The DFM framework is illustrated with a set of 8 groundwater head series and applied for filling gaps in time series, reconstructing high-frequency data, and detecting outliers.

  1. [Prognostic factors in head and neck mucoepidermoid carcinoma].

    PubMed

    Villavicencio-Ayala, Beatriz; Reséndiz-Colosia, Jaime Alonso; Labastida-Almendaro, Sonia; Torres-Núñe, María Guadalupe; Peña-Torres, Leandro Miguel; Gallegos-Hernández, José Francisco

    2008-01-01

    In patients with mucoepidermoid carcinoma (MEC) originating in salivary glands, because of the relative rarity of these tumors and the remarkable variability in their biological behavior, opinions differ about appropriate classification, grading, and treatment. We undertook this study to analyze clinical and histological prognostic factors in a series of patients with MEC using univariate and multivariate survival analyses. We reviewed 47 patients with MEC treated at our institution from 1985 to 2000. Clinical, epidemiological, treatment and follow-up data were obtained from medical records. All cases were histologically reviewed. The influence of prognostic factors on 5- and 10-year disease-specific survival was analyzed using Kaplan-Meier actuarial method and log-rank test. Cox regression tests were used to analyze the impact of the prognostic factors on survival. Females represented 59.6% of the patients. The major salivary glands were affected in 74.5%. Overall survival at 5 and 10 years was 78.3% and 69.3%, respectively. Disease-free survival at 5 years was 73.9% and at 10 years was 67.5%. Multivariate survival analysis revealed that tumor size (T4) (p = 0.0008), regional metastasis (p = 0.000), high histological grade (p = 0.0002), perineural invasion (p = 0.000), positive margin (p = 0.000), necrosis (p = 0.005), and intracystic component <20% (p = 0.0002) were all correlated with a poor prognosis. Clinical stage and histological grade are the main prognostic factors in mucoepidermoid carcinoma. Nevertheless, our univariate and multivariate analyses showed that other clinical and histological prognostic factors are independent significant indicators.

  2. Pain in head and neck cancer: prevalence and possible predictive factors.

    PubMed

    Bianchini, Chiara; Maldotti, Francesco; Crema, Laura; Malagò, Mariasole; Ciorba, Andrea

    2014-01-01

    The purpose of this article was to review the main aspects of pain and its prevalence among head and neck cancer patients, as well as to identify the presence of possible pain predictive factors. For an integrated presentation of this topic a Pubmed database systematic search for relevant published studies was performed. When considering the prevalence of pain in head and neck cancer patients the studies available in this field show great variations in relation to the number of patients included, surgical procedures performed, and established approaches to analgesia. Despite the recognized association between cancer and pain, insufficient attention is paid in the head and neck pain problem, and to date, only few studies in the literature address the diagnosis of head and neck pain or its management. Further efforts are necessary in order to understand the real dimension of this problem in head and neck cancer patients, and therefore to recognize pain predictive factors and/or pain genetic factors aiming (i) to identify those subjects most at risk for pain, and (ii) to tailor, in a near future, 'targeted' analgesic interventions.

  3. Factors affecting head growth and intellectual function in children of drug addicts.

    PubMed

    Lifschitz, M H; Wilson, G S; Smith, E O; Desmond, M M

    1985-02-01

    The effect of maternal heroin and methadone use on head growth and neurodevelopmental performance was studied in preschool children of untreated heroin addicts (n = 25), women receiving methadone therapy (n = 26), and a drug-free comparison group (n = 41) who had been followed from birth. The mean birth head circumference of both groups of drug-exposed infants was significantly below that of the comparison group; however, the only factors determined by multiple regression analysis as associated with head size at birth were maternal nutritional status and birth weight. By preschool age, head size did not differ significantly among groups. The factors associated with postnatal head growth were birth weight, intrapartum risk score, and race. Data show an increased incidence of low-average and mildly retarded intellectual performance in the drug-exposed children. Regression analyses demonstrated that amount of prenatal care, prenatal risk score, and home environment were most predictive of intellectual performance and that the degree of maternal narcotic use was not a significant factor.

  4. Factors associated with malnutrition in patients with head and neck cancer.

    PubMed

    Takenaka, Yukinori; Yamamoto, Masashi; Nakahara, Susumu; Yamamoto, Yoshifumi; Yasui, Toshimichi; Hanamoto, Atshushi; Takemoto, Norihiko; Fukusumi, Takahito; Michiba, Takahiro; Cho, Hironori; Inohara, Hidenori

    2014-10-01

    Comorbidities as well as T classification were the primary determinants for the nutritional status of patients with head and neck cancer. We aimed to elucidate the underlying conditions of malnutrition in patients with head and neck cancer. We retrospectively reviewed 726 patients diagnosed with head and neck cancer between 2004 and 2013. Associations between malnutrition and clinical parameters were assessed using univariate and multivariate analyses. Median body mass index was 21.5 (range 11.6-38.0). According to World Health Organization criteria, the nutritional status of these patients was classified into four groups: underweight (18%), normal (63%), overweight (17%), and obese (1%). Comorbidities were detected in 40% of patients. Multivariate analysis revealed the following factors to be independent factors associated with malnutrition: advanced T stage, metachronous cancer, collagen disease, gastrointestinal disease, and pulmonary disease.

  5. Patient size and x-ray technique factors in head computed tomography examinations. I. Radiation doses.

    PubMed

    Huda, Walter; Lieberman, Kristin A; Chang, Jack; Roskopf, Marsha L

    2004-03-01

    We investigated how patient age, size and composition, together with the choice of x-ray technique factors, affect radiation doses in head computed tomography (CT) examinations. Head size dimensions, cross-sectional areas, and mean Hounsfield unit (HU) values were obtained from head CT images of 127 patients. For radiation dosimetry purposes patients were modeled as uniform cylinders of water. Dose computations were performed for 18 x 7 mm sections, scanned at a constant 340 mAs, for x-ray tube voltages ranging from 80 to 140 kV. Values of mean section dose, energy imparted, and effective dose were computed for patients ranging from the newborn to adults. There was a rapid growth of head size over the first two years, followed by a more modest increase of head size until the age of 18 or so. Newborns have a mean HU value of about 50 that monotonically increases with age over the first two decades of life. Average adult A-P and lateral dimensions were 186+/-8 mm and 147+/-8 mm, respectively, with an average HU value of 209+/-40. An infant head was found to be equivalent to a water cylinder with a radius of approximately 60 mm, whereas an adult head had an equivalent radius 50% greater. Adult males head dimensions are about 5% larger than for females, and their average x-ray attenuation is approximately 20 HU greater. For adult examinations performed at 120 kV, typical values were 32 mGy for the mean section dose, 105 mJ for the total energy imparted, and 0.64 mSv for the effective dose. Increasing the x-ray tube voltage from 80 to 140 kV increases patient doses by about a factor of 5. For the same technique factors, mean section doses in infants are 35% higher than in adults. Energy imparted for adults is 50% higher than for infants, but infant effective doses are four times higher than for adults. CT doses need to take into account patient age, head size, and composition as well as the selected x-ray technique factors.

  6. Time of elevation of head of bed for patients receiving mechanical ventilation and its related factors.

    PubMed

    Martí-Hereu, L; Arreciado Marañón, A

    2017-06-08

    The semirecumbent position is a widespread recommendation for the prevention of pneumonia associated with mechanical ventilation. To identify the time of elevation of head of bed for patients under mechanical ventilation and the factors related to such elevation in an intensive care unit. An observational, descriptive cross-sectional study. Conducted in an intensive care unit of a tertiary hospital from April to June 2015. The studied population were mechanically ventilated patients. Daily hours in which patients remained with the head of the bed elevated (≥30°), socio-demographic data and clinical variables were recorded. 261 head elevation measurements were collected. The average daily hours that patients remained at ≥30° was 16h28' (SD ±5h38'), equivalent to 68.6% (SD ±23.5%) of the day. Factors related to elevations ≥30° for longer were: enteral nutrition, levels of deep sedation, cardiac and neurocritical diagnostics. Factors that hindered the position were: sedation levels for agitation and abdominal pathologies. Sex, age and ventilation mode did not show a significant relationship with bed head elevation. Although raising the head of the bed is an easy to perform, economical and measurable preventive measure, its compliance is low due to specific factors specific related o the patient's clinical condition. Using innovations such as continuous measurement of the head position helps to evaluate clinical practice and allows to carry out improvement actions whose impact is beneficial to the patient. Copyright © 2017 Sociedad Española de Enfermería Intensiva y Unidades Coronarias (SEEIUC). Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Factors affecting the aluminium content of human femoral head and neck.

    PubMed

    Zioła-Frankowska, Anetta; Dąbrowski, Mikołaj; Kubaszewski, Łukasz; Rogala, Piotr; Frankowski, Marcin

    2015-11-01

    Tissues for the study were obtained intraoperatively during hip replacement procedures from 96 patients. In all the cases, the indication for this treatment was primary or secondary degenerative changes in the hip joint. The subject of the study was the head and neck of the femur, resected in situ. Aluminium concentrations measured in femoral head and neck samples from patients aged between 25 and 91 were varied. Statistical methods were applied to determine the variations in relation to the parameters from the background survey. Significant differences in the aluminium content of femoral head samples were observed between patients under and over 60 years of age. Based on the results, it was confirmed that the aluminium accumulates in bones over a lifetime. The study showed that the content of aluminium in the head and neck of the femur depends on the factors such as: type of medicines taken, contact with chemicals at work, differences in body anatomy and sex. The study on the levels of aluminium in bones and the factors affecting its concentration is a valuable source of information for further research on the role of aluminium in bone diseases. Based on the investigations, it was found that the GF-AAS technique is the best analytical tool for routine analysis of aluminium in complex matrix samples. The use of femoral heads in the investigations was approved by the Bioethics Committee of the University of Medical Sciences in Poznań (Poland). Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Risk factors for head injury events in professional rugby union: a video analysis of 464 head injury events to inform proposed injury prevention strategies.

    PubMed

    Tucker, Ross; Raftery, Martin; Kemp, Simon; Brown, James; Fuller, Gordon; Hester, Ben; Cross, Matthew; Quarrie, Ken

    2017-08-01

    The tackle is responsible for the majority of head injuries during rugby union. In order to address head injury risk, risk factors during the tackle must first be identified. This study analysed tackle characteristics in the professional game in order to inform potential interventions. 464 tackles resulting in a head injury assessment (HIA) were analysed in detail, with tackle type, direction, speed, acceleration, nature of head contact and player body position the characteristics of interest. Propensity to cause an HIA was significantly greater for active shoulder tackles, front-on tackles, high speeder tackles and an accelerating tackler. Head contact between a tackler's head and ball carrier's head or shoulder was significantly more likely to cause an HIA than contact below the level of the shoulder (incident rate ratio (IRR) 4.25, 95%-CI 3.38 to 5.35). The tackler experiences the majority (78%) of HIAs when head-to-head contact occurs. An upright tackler was 1.5 times more likely to experience an HIA than a bent at the waist tackler (IRR 1.44, 95% CI 1.18 to 1.76). This study confirms that energy transfer in the tackle is a risk factor for head injury, since direction, type and speed all influence HIA propensity. The study provides evidence that body position and the height of tackles should be a focus for interventions, since lowering height and adopting a bent at the waist body position is associated with reduced risk for both tacklers and ball carriers. To this end, World Rugby has implemented law change based on the present data. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  9. Factors that Impact West Virginia Head Start Parental Involvement in Early Literacy

    ERIC Educational Resources Information Center

    Clausell, Arlene Midget

    2010-01-01

    The research problem is: Many parents are not involved in their children's early literacy education. Some Head Start parents experience issues that keep them from teaching their children early literacy skills. The research questions were: What are the factors for parental involvement in the support of early literacy skill development for their…

  10. Factors Associated with Head Start Staff Participation in Classroom-Based Professional Development

    ERIC Educational Resources Information Center

    Trivette, Carol M.; Raab, Melinda; Dunst, Carl J.

    2014-01-01

    Factors associated with Head Start staff participation in a classroom-based professional development project to promote their use of evidence-based child learning opportunity practices and evidence-based responsive teaching procedures were examined in a study of 36 teachers and teacher assistants in 19 different classrooms. The factors…

  11. Assessment of Factors Resulting in Abuse Evaluations in Young Children with Minor Head Trauma

    ERIC Educational Resources Information Center

    Anderst, James D.

    2008-01-01

    Objective: The primary objective was to determine which of the examined factors prompted physicians to initiate a further abuse evaluation in young children with minor head injury. The recording of important historical elements in the charts of these patients was also evaluated. Methods: Charts of 349 children less than 3 years of age with minor…

  12. Assessment of Factors Resulting in Abuse Evaluations in Young Children with Minor Head Trauma

    ERIC Educational Resources Information Center

    Anderst, James D.

    2008-01-01

    Objective: The primary objective was to determine which of the examined factors prompted physicians to initiate a further abuse evaluation in young children with minor head injury. The recording of important historical elements in the charts of these patients was also evaluated. Methods: Charts of 349 children less than 3 years of age with minor…

  13. Finding electromagnetic and chemical enhancement factors of surface-enhanced Raman scattering.

    PubMed

    Dvoynenko, Mykhaylo M; Wang, Juen-Kai

    2007-12-15

    The authors report two methods to determine electromagnetic and chemical enhancement factors in surface-enhanced Raman scattering (SERS), which are based on saturation property and decay dynamics of photoluminescence and concurrent measurements of photoluminescence and resonance Raman scattering intensities. Considerations for experimental implementation are discussed. This study is expected to facilitate the understanding of SERS mechanisms and the advancement of the usage of SERS in chemical and biological sensor applications.

  14. Measurement of the neutron electric form factor GEn in quasielastic scattering

    SciTech Connect

    Donal Day

    2003-07-15

    We have measured the electric form factor of the neutron, GEn, at two momentum transfers (Q2= 0.5 and Q2= 1.0 GeV/c2) through quasielastic scattering in Jefferson Lab's Hall C. Longitudinally polarized electrons scattered from polarized deuterated ammonia and GEn was extracted from the beam-target asymmetry AVed which, in quasielastic kinematics, is particularly sensitive to GEn and insensitive to MEC and FSI.

  15. [Factors of avascular necrosis of femoral head and osteoporosis in SARS patients' convalescence].

    PubMed

    Li, Yu-ming; Wang, Shi-xin; Gao, Hong-sheng; Wang, Jing-gui; Wei, Chuan-she; Chen, Li-ming; Hui, Wu-li; Yuan, Shu-ling; Jiao, Zhen-shan; Yang, Zhen; Su, Bin

    2004-08-17

    To explore the factors affecting the pathogenesis of avascular necrosis of femoral head and osteoporosis of SARS patients during convalescent stage. The clinical data of 40 SARS patients, 12 males and 28 females, aged 29 +/- 9, hospitalized from April to June 2003, were reviewed, targeted on the use of glucocorticoids. Three months after the discharge ELISA and indirect immunofluorescent antibody (IFA) assay were used to detect the serum IgG. Magnetic resonance imaging (MRI) was used to detect the damage of the head of femur and quantitative ultrasound (QUS) was used to detect osteoporosis at the left heel. The average total dosage of methylprednisolone was (4949 +/- 2959) mg, and the average course of treatment was (24 +/- 5) days (16 to 30 days). Twenty-three patients underwent ictus therapy of corticosteroids for (8 +/- 4) days. The extenuation time of corticosteroid' dosage was (33 +/- 26) mg/d. Of the 40 patients, 36 were IgG positive with an average A value of (0.91 +/- 0.24) and 4 patients were IgG negative. Twelve patients (30%) were with type I avascular necrosis of femoral head, including 3 cases with unilateral left--necrosis and 9 cases of bilateral necrosis. The other 28 patients were without necrosis. Two patients were suffering from osteoporosis and 30 patients were with bone density decrement. The average Z values of the parameter BUA and VOS were (-1.26 +/- 0. 53) and (-0.53 +/- 0.30) respectively. The corresponding T values of the parameter BUA and VOS were (-1.49 +/- 0.59) and (-0.65 +/- 0.05) respectively. The influencing factors of femoral necrosis included the degree of healing activity, the dosage summation of corticosteroids, and length of ictus therapy. The influencing factors of bone density included age, dosage summation, and length of ictus therapy. The influencing factors of the bone fabric and flexibility included the use and length of ictus therapy. Statistics showed that serum IgG was not related with avascular necrosis of femoral

  16. Towards the estimation of the scattered energy spectra reaching the head of the medical staff during interventional radiology: A Monte Carlo simulation study

    NASA Astrophysics Data System (ADS)

    Zagorska, A.; Bliznakova, K.; Buchakliev, Z.

    2015-09-01

    In 2012, the International Commission on Radiological Protection has recommended a reduction of the dose limits to the eye lens for occupational exposure. Recent studies showed that in interventional rooms is possible to reach these limits especially without using protective equipment. The aim of this study was to calculate the scattered energy spectra distribution at the level of the operator's head. For this purpose, an in-house developed Monte Carlo-based computer application was used to design computational phantoms (patient and operator), the acquisition geometry as well as to simulate the photon transport through the designed system. The initial spectra from 70 kV tube voltage and 8 different filtrations were calculated according to the IPEM Report 78. An experimental study was carried out to verify the results from the simulations. The calculated scattered radiation distributions were compared to the initial incident on the patient spectra. Results showed that there is no large difference between the effective energies of the scattered spectra registered in front of the operator's head obtained from simulations of all 8 incident spectra. The results from the experimental study agreed well to simulations as well.

  17. Hepatocyte Growth Factor/Scatter Factor Released during Peritonitis Is Active on Mesothelial Cells

    PubMed Central

    Rampino, Teresa; Cancarini, Giovanni; Gregorini, Marilena; Guallini, Paola; Maggio, Milena; Ranghino, Andrea; Soccio, Grazia; Dal Canton, Antonio

    2001-01-01

    Peritonitis causes mesothelial detachment that may result in persistent peritoneal denudation and fibrosis. We investigated whether hepatocyte growth factor (HGF), a scatter factor that induces detachment from substrate and fibroblastic transformation of several cell types, is produced during peritonitis and is active on mesothelial cells. We studied 18 patients on peritoneal dialysis, 9 uncomplicated, 9 with peritonitis. HGF was measured in serum, peritoneal fluid, and supernatant of peripheral blood mononuclear cells and peritoneal mononuclear cells. Primary culture of human peritoneal mesothelial cells and the human mesothelial cell line MeT-5A were conditioned with recombinant HGF, serum, and peritoneal fluid. HGF levels were significantly higher in serum and peritoneal fluid of peritonitic than uncomplicated patients. Mononuclear cells of peritonitic patients produced more HGF than cells of uncomplicated patients. Recombinant HGF, serum, and peritoneal fluid of peritonitic patients caused mesothelial cell growth, detachment, transformation from epithelial to fibroblast-like shape, overexpression of vimentin, and synthesis of type I and III collagen. In conclusion, HGF released during peritonitis causes a change in mesothelial cell phenotype and function. HGF may affect the healing process facilitating repair through mesothelial cell growth, but may contribute to peritoneal fibrosis inducing cell detachment with mesothelial denudation and collagen synthesis. PMID:11583955

  18. Rhabdomyosarcoma of the head and neck: impact of demographic and clinicopathologic factors on survival.

    PubMed

    Lee, Robert J; Lee, Kevin K; Lin, Thomas; Arshi, Armin; Lee, Serena A; Christensen, Russell E

    2017-09-01

    To determine the survival factors for patients diagnosed with rhabdomyosarcoma of the head and neck. Data on patients diagnosed with rhabdomyosarcoma of the head and neck between 1973 and 2012 were extracted from the Surveillance, Epidemiology, and End Results database. Kaplan-Meier and Cox proportional hazard regression models were used to determine the demographic characteristics, prognostic factors, and treatment modalities that determine overall survival (OS) and disease-specific survival (DSS). Data on 503 patients diagnosed with rhabdomyosarcoma of the head and neck were analyzed; 51.3% were male and 48.7% were female, with a median OS of 4.9 years. Kaplan-Meier analysis determined 5-year survival rates of 30% for OS and 50% for DSS. Multivariate analysis found that age at diagnosis, tumor extent of disease, surgical resection, and radiation therapy were independent predictors of OS and DSS. To our knowledge, this is the largest year-span study to date to determine the factors of survival for rhabdomyosarcoma of the head and neck. Older age at diagnosis, histologic subtype of alveolar rhabdomyosarcoma, and further extent of disease were associated with decreased survival. Surgical resection improves survival in patients with localized or regional disease, and radiation therapy confers survival benefits in patients with distant extent. Published by Elsevier Inc.

  19. In-vivo Optical Tomography of Small Scattering Specimens: time-lapse 3D imaging of the head eversion process in Drosophila melanogaster

    PubMed Central

    Arranz, Alicia; Dong, Di; Zhu, Shouping; Savakis, Charalambos; Tian, Jie; Ripoll, Jorge

    2014-01-01

    Even though in vivo imaging approaches have witnessed several new and important developments, specimens that exhibit high light scattering properties such as Drosophila melanogaster pupae are still not easily accessible with current optical imaging techniques, obtaining images only from subsurface features. This means that in order to obtain 3D volumetric information these specimens need to be studied either after fixation and a chemical clearing process, through an imaging window - thus perturbing physiological development -, or during early stages of development when the scattering contribution is negligible. In this paper we showcase how Optical Projection Tomography may be used to obtain volumetric images of the head eversion process in vivo in Drosophila melanogaster pupae, both in control and headless mutant specimens. Additionally, we demonstrate the use of Helical Optical Projection Tomography (hOPT) as a tool for high throughput 4D-imaging of several specimens simultaneously. PMID:25471694

  20. Measurement of Total Scatter Factor for Stereotactic Cones with Plastic Scintillation Detector

    PubMed Central

    Chaudhari, Suresh H; Dobhal, Rishabh; Kinhikar, Rajesh A.; Kadam, Sudarshan S.; Deshpande, Deepak D.

    2017-01-01

    Advanced radiotherapy modalities such as stereotactic radiosurgery (SRS) and image-guided radiotherapy may employ very small beam apertures for accurate localized high dose to target. Accurate measurement of small radiation fields is a well-known challenge for many dosimeters. The purpose of this study was to measure total scatter factors for stereotactic cones with plastic scintillation detector and its comparison against diode detector and theoretical estimates. Measurements were performed on Novalis Tx™ linear accelerator for 6MV SRS beam with stereotactic cones of diameter 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm. The advantage of plastic scintillator detector is in its energy dependence. The total scatter factor was measured in water at the depth of dose maximum. Total scatter factor with plastic scintillation detector was determined by normalizing the readings to field size of 10 cm × 10 cm. To overcome energy dependence of diode detector for the determination of scatter factor with diode detector, daisy chaining method was used. The plastic scintillator detector was calibrated against the ionization chamber, and the reproducibility in the measured doses was found to be within ± 1%. Total scatter factor measured with plastic scintillation detector was 0.728 ± 0.3, 0.783 ± 0.05, 0.866 ± 0.55, 0.885 ± 0.5, and 0.910 ± 0.06 for cone sizes of 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. Total scatter factor measured with diode detector was 0.733 ± 0.03, 0.782 ± 0.02, 0.834 ± 0.07, 0.854 ± 0.02, and 0.872 ± 0.02 for cone sizes of 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. The variation in the measurement of total scatter factor with published Monte Carlo data was found to be −1.3%, 1.9%, −0.4%, and 0.4% for cone sizes of 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. We conclude that total scatter factor measurements for stereotactic cones can be adequately carried out with a plastic scintillation detector. Our results show

  1. Logistic regression analysis of risk factors for femoral head osteonecrosis after healed intertrochanteric fractures.

    PubMed

    Yin, Wenjing; Xu, Zhengliang; Sheng, Jiagen; Zhang, Changqing; Zhu, Zhenhong

    2016-05-16

    To evaluate the potential risk factors of the development of femoral head osteonecrosis after healed intertrochanteric fractures. We retrospectively reviewed all patients who were operated upon with closed reduction and internal fixation for intertrochanteric fractures by our medical group from December 1993 to December 2012. Patients with healed fractures were identified. Age, gender, comorbidities favouring osteonecrosis, causes of injuries, fracture patterns, the location of the primary fracture line, time from injury to surgery, fixation methods, and the development of femur head osteonecrosis of these patients were summarised. Univariate and multivariate logistic regression analysis were performed to evaluate the correlation between potential risk factors and the development of femoral head osteonecrosis. A total of 916 patients with healed intertrochanteric fractures were identified. Femoral head osteonecrosis was found in 8 cases (0.87%). According to the results of univariate logistic regression, a more proximal fracture line, fixation with dynamic hip screws and age were found to be statistically significant factors. The results of multivariate logistic regression analysis indicated that the statistically significant predictors of femoral head osteonecrosis were younger age (odds ratio [OR] = 17.103; 95% confidence interval [CI], 1.988-147.111), a more proximal fracture line (OR = 31.439; 95% CI, 3.700-267.119) and applying dynamic hip screw as the internal fixation (OR = 11.114; 95% CI, 2.064-59.854). Regular follow-up is commended in young patients with a proximal fracture line who underwent closed reduction and internal fixation with dynamic hip screw, even though the bone had healed.

  2. An analytical formalism to calculate phantom scatter factors for flattening filter free (FFF) mode photon beams.

    PubMed

    Chung, Heeteak; Prado, Karl L; Yi, Byong Yong

    2014-02-21

    Phantom Scatter Factors, Sp in the Khan formalism (Khan et al 1980 J. Radiat. Oncol. Biol. Phys. 6 745-51) describe medium-induced changes in photon-beam intensity as a function of size of the beam. According to the British Journal of Radiology, Supplement 25, megavoltage phantom scatter factors are invariant as a function of photon-beam energy. However, during the commissioning of an accelerator with flattening filter free (FFF) photon beams (Varian TrueBeam(TM) 6-MV FFF and 10-MV FFF), differences were noted in phantom scatter between the filtered beams and FFF-mode beams. The purpose of this work was to evaluate this difference and provide an analytical formalism to explain the phantom scatter differences between FFF-mode and the filtered mode. An analytical formalism was devised to demonstrate the source of phantom scatter differences between the filtered and the FFF-mode beams. The reason for the differences in the phantom scatter factors between the filtered and the FFF-mode beams is hypothesized to be the non-uniform beam profiles of the FFF-mode beams. The analytical formalism proposed here is based on this idea, taking the product of the filtered phantom scatter factors and the ratio of the off-axis ratio between the FFF-mode and the filtered beams. All measurements were performed using a Varian TrueBeam(TM) linear accelerator with photon energies of 6-MV and 10-MV in both filtered and FFF-modes. For all measurements, a PTW Farmer type chamber and a Scanditronix CC04 cylindrical ionization were used. The in-water measurements were made at depth dose maximum and 100 cm source-to-axis distance. The in-air measurements were done at 100 cm source-to-axis distance with appropriate build-up cap. From these measurements, the phantom scatter factors were derived for the filtered beams and the FFF-mode beams for both energies to be evaluated against the phantoms scatter factors calculated using the proposed algorithm. For 6-MV, the difference between the measured

  3. An analytical formalism to calculate phantom scatter factors for flattening filter free (FFF) mode photon beams

    NASA Astrophysics Data System (ADS)

    Chung, Heeteak; Prado, Karl L.; Yi, Byong Yong

    2014-02-01

    Phantom Scatter Factors, Sp in the Khan formalism (Khan et al 1980 J. Radiat. Oncol. Biol. Phys. 6 745-51) describe medium-induced changes in photon-beam intensity as a function of size of the beam. According to the British Journal of Radiology, Supplement 25, megavoltage phantom scatter factors are invariant as a function of photon-beam energy. However, during the commissioning of an accelerator with flattening filter free (FFF) photon beams (Varian TrueBeamTM 6-MV FFF and 10-MV FFF), differences were noted in phantom scatter between the filtered beams and FFF-mode beams. The purpose of this work was to evaluate this difference and provide an analytical formalism to explain the phantom scatter differences between FFF-mode and the filtered mode. An analytical formalism was devised to demonstrate the source of phantom scatter differences between the filtered and the FFF-mode beams. The reason for the differences in the phantom scatter factors between the filtered and the FFF-mode beams is hypothesized to be the non-uniform beam profiles of the FFF-mode beams. The analytical formalism proposed here is based on this idea, taking the product of the filtered phantom scatter factors and the ratio of the off-axis ratio between the FFF-mode and the filtered beams. All measurements were performed using a Varian TrueBeamTM linear accelerator with photon energies of 6-MV and 10-MV in both filtered and FFF-modes. For all measurements, a PTW Farmer type chamber and a Scanditronix CC04 cylindrical ionization were used. The in-water measurements were made at depth dose maximum and 100 cm source-to-axis distance. The in-air measurements were done at 100 cm source-to-axis distance with appropriate build-up cap. From these measurements, the phantom scatter factors were derived for the filtered beams and the FFF-mode beams for both energies to be evaluated against the phantoms scatter factors calculated using the proposed algorithm. For 6-MV, the difference between the measured and

  4. Inelastic electron scattering from a helical potential: transverse polarization and the structure factor in the single scattering approximation.

    PubMed

    Varela, Solmar; Medina, Ernesto; López, Floralba; Mujica, Vladimiro

    2014-01-08

    We analyze single scattering of unpolarized photoelectrons through a monolayer of chiral molecules modeled by a continuous hardcore helix and spin-orbit coupling. The molecular helix is represented by an optical contact potential containing a non-hermitian component describing inelastic events. Transmitted photoelectrons are transversely polarized at optimal angles, and separated into up and down spin with up to 20% efficiency. Such a process involves the interference of both spin-orbit and inelastic strengths, that are parameterized quantitatively to recent experiments in chiral self-assembled monolayers (SAMs). The structure factor of the model chiral molecule shows the energy dependence of the differential cross section which decays strongly as energy increases. Larger incident momenta reduce axial deviations from the forward direction and the spin-orbit interaction becomes less effective. Transverse electron polarization is then restricted to a characteristic energy window.

  5. [Air kerma transmission factors of Scattered X-rays in the maze of a Linac room for lead shield].

    PubMed

    Kato, Hideki

    2005-01-20

    Spectra of scattered X-rays in the maze of a Linac (X-ray energies of 4, 6, and 10 MV) room were estimated by means of the Monte Carlo simulation, and air kerma transmission factors of the X-rays scattered through a lead shield were evaluated based on those spectra. Spectra of scattered X-rays showed a maximum in the energy area below 200 keV. The higher the accelerated electron energy, also, the smaller the scattering angle that tended to spread to the higher energy area of the distribution of spectra. The air kerma transmission factor of 120 degrees scattered X-rays of 4 MV X-rays obtained in this study was larger than the transmission factors of 124 degrees scattered photons of (60)Co gamma rays through a lead shield given in ICRP. The air kerma transmission factors of 120 degrees scattered X-rays of 6 MV X-rays were smaller than the transmission factors of 90 degrees scattered photons of (60)Co gamma rays. The air kerma transmission factors of 120 degrees scattered X-rays of 10 MV X-rays was slightly larger than transmission factors of 90 degrees scattered photons of (60)Co gamma rays. Therefore, in the case of a 4 MV X-ray Linac room, the calculation method given in the "Manual of Practical Shield Calculation of Radiation Facilities (2000)" causes underestimation of leakage doses.

  6. Scattering from phase-separated vesicles. I. An analytical form factor for multiple static domains

    DOE PAGES

    Heberle, Frederick A.; Anghel, Vinicius N. P.; Katsaras, John

    2015-08-18

    This is the first in a series of studies considering elastic scattering from laterally heterogeneous lipid vesicles containing multiple domains. Unique among biophysical tools, small-angle neutron scattering can in principle give detailed information about the size, shape and spatial arrangement of domains. A general theory for scattering from laterally heterogeneous vesicles is presented, and the analytical form factor for static domains with arbitrary spatial configuration is derived, including a simplification for uniformly sized round domains. The validity of the model, including series truncation effects, is assessed by comparison with simulated data obtained from a Monte Carlo method. Several aspects ofmore » the analytical solution for scattering intensity are discussed in the context of small-angle neutron scattering data, including the effect of varying domain size and number, as well as solvent contrast. Finally, the analysis indicates that effects of domain formation are most pronounced when the vesicle's average scattering length density matches that of the surrounding solvent.« less

  7. Clinical Risk Factors for Head Impact During Falls in Older Adults: A Prospective Cohort Study in Long-Term Care.

    PubMed

    Yang, Yijian; Mackey, Dawn C; Liu-Ambrose, Teresa; Leung, Pet-Ming; Feldman, Fabio; Robinovitch, Stephen N

    To examine risk factors associated with head impact during falls in older adults in long-term care (LTC). Two LTC facilities in British Columbia, Canada. 160 LTC residents. Prospective cohort study. Between 2007 and 2014, we video captured 520 falls experienced by participants. Each fall video was analyzed to determine whether impact occurred to the head. Using generalized estimating equation models, we examined how head impact was associated with other fall characteristics and health status prior to the fall. Head impact occurred in 33% of falls. Individuals with mild cognitive impairment were at higher risk for head impact (odds ratio = 2.8; 95% confidence interval, 1.5-5.0) than those with more severe cognitive impairment. Impaired vision was associated with 2.0-fold (1.3-3.0) higher odds of head impact. Women were 2.2 times (1.4-3.3) more likely than men to impact their head during a fall. Head impact is common during falls in LTC, with less cognitively impaired, female residents who suffered from visual impairment, being most likely to impact their head. Future research should focus on improving our ability to detect neural consequences of head impact and evaluating the effect of interventions for reducing the risk for fall-related head injuries in LTC.

  8. Some physical factors influencing the accuracy of convolution scatter correction in SPECT.

    PubMed

    Msaki, P; Axelsson, B; Larsson, S A

    1989-03-01

    Some important physical factors influencing the accuracy of convolution scatter correction techniques in SPECT are presented. In these techniques scatter correction in the projection relies on filter functions, QF, evaluated by Fourier transforms, from measured scatter functions, Qp, obtained from point spread functions. The spatial resolution has a marginal effect on Qp. Thus a single QF can be used in the scatter correction of SPECT measurements acquired with the low energy high resolution or the low energy general purpose collimators and over a wide range of patient-collimator distances. However, it is necessary to examine the details of the shape of point spread functions during evaluation of Qp. QF is completely described by scatter amplitude AF, slope BF and filter sum SF. SF is obtained by summation of the values of QF occupying a 31 x 31 pixels matrix. Regardless of differences in amplitude and slope, two filter functions are shown to be equivalent in terms of scatter correction ability, whenever their sums are equal. On the basis of filter sum, the observed small influence of ellipticity on QF implies that an average function can be used in scatter correcting SPECT measurements conducted with elliptic objects. SF is shown to increase with a decrease in photon energy and with an increase in window size. Thus, scatter correction by convolution may be severely hampered by photon statistics when SPECT imaging is done with low-energy photons. It is pointless to use unnecessarily large discriminator windows, in the hope of improving photon statistics, since most of the extra events acquired will eventually be subtracted during scatter correction. Regardless of the observed moderate reduction in SF when a lung-equivalent material replaces a portion of a water phantom, further studies are needed to develop a technique that is capable of handling attenuation and scatter corrections simultaneously. Whenever superficial and inner radioactive distributions coexist the

  9. X-Ray Elastic and Inelastic Scattering Factors for Neutral Atoms Z = 2-92

    NASA Astrophysics Data System (ADS)

    Wang, J. H.; Sagar, R. P.; Schmider, H.; Smith, V. H.

    1993-03-01

    X-ray elastic and inelastic scattering factors are calculated for the ground states of the neutral atoms, helium to uranium, from the Roothaan-Hartree-Fock nonrelativistic self-consistent-field wave functions of Clementi and Roetti, (Atomic Data and Nuclear Data Tables 14, 177, 1974) and McLean and McLean (Atomic Data and Nuclear Data Tables 26, 197, 1981).

  10. Prognostic factors and epidemiological characteristics of cutaneous and mucosal head and neck melanoma.

    PubMed

    Berzina, Anna; Azarjana, Kristine; Cema, Ingrida; Pjanova, Dace; Rivosh, Alexander

    2011-01-01

    OBJECTIVE. To describe the prognostic factors and epidemiological characteristics of cutaneous and mucosal head and neck melanoma and to identify the variables associated with mortality from this disease. MATERIAL AND METHODS. Patients treated for head and neck melanoma in the Oncology Centre of Latvia, Riga during a 10-year period were identified. Records from 124 cases were analyzed in a descriptive, retrospective study. For each patient, information regarding age, sex, tumor anatomic site, as well as ulceration, histological tumor subtypes, Breslow thickness and Clark invasion level was viewed. Disease specific survival rates were calculated. The frequencies of all study variables and their 95% confidence intervals were determined. Kaplan-Meier survival curves were produced to illustrate the survival differences for each variable. RESULTS. The patients' mean age was 67.36 years. The study included 81 females (65.32%) and 43 males (34.67%). The prevalent anatomical site for cutaneous head and neck melanoma was the cheek - 49% (n=55) and the intraocular site for mucosal melanoma (61.5%). A high percentage of thick cutaneous melanoma was detected. In 53 cases (47.3%) out of 112 cutaneous melanoma the tumor ulceration was found. Nodular melanoma subtype was predominating (38%). The incidence of cutaneous melanoma has increased unequally whereas mucosal melanoma of the head and neck is an uncommon cancer and the incidence rates in Latvia during a ten year period are decreasing. CONCLUSION. Female sex, advanced age, facial skin, tumor thickness, nodular subtype and ulceration carried a relevant risk of poor prognosis.

  11. Pneumonia in patients with severe head injury: incidence, risk factors, and outcomes.

    PubMed

    Wang, Kuo-Wei; Chen, Han-Jung; Lu, Kang; Liliang, Po-Chou; Huang, Chun-Kai; Tang, Pi-Lien; Tsai, Yu-Duan; Wang, Hao-Kuang; Liang, Cheng-Loong

    2013-02-01

    The reported incidence of hospital-acquired bacterial pneumonia in critically ill trauma patients varies from as low as 4% to as high as 87%, with fatality rates varying from 6% to 59%. Clinical studies have identified the risk factors for pneumonia. The authors undertook this retrospective study to evaluate the incidence, risk factors, and outcomes of hospital-acquired bacterial pneumonia in a group of patients with severe head injuries. This was a retrospective review of consecutive adult patients admitted to the neurosurgical ICU in the authors' hospital because of severe head injury (Glasgow Coma Scale scores ≤ 8) between January 2008 and December 2010. During the study period, 290 patients were admitted to the neurosurgical ICU. Multivariate Cox regression analysis showed that age (HR 1.01, 95% CI 1.001-1.02), nasogastric tube insertion (HR 4.56, 95% CI 1.11-18.64), and hemiplegia or hemiparesis (HR 3.79, 95% CI 2.01-7.17) were significantly associated with the development of pneumonia. The authors identified 3 risk factors (age, nasogastric tube insertion, and hemiplegia or hemiparesis) associated with the development of pneumonia in patients with severe head injury. This finding constituted the basis for developing a simple screening tool that can be used to assess the risk of occurrence of pneumonia in such patients.

  12. Light-by-light scattering in the Lamb shift and the bound electron g factor

    NASA Astrophysics Data System (ADS)

    Czarnecki, Andrzej; Szafron, Robert

    2016-12-01

    We compute an O ( α2(Zα ) 6) contribution to the hydrogen-atom Lamb shift arising from light-by-light scattering. Analogous diagrams, with one atomic electric field insertion replaced by an external magnetic field, contribute to the gyromagnetic factor of the bound electron at O ( α2(Zα ) 4) . We also calculate the contribution to the gyromagnetic factor from the muon magnetic loop.

  13. Prevalence and risk factors of depressive disorder in caregivers of patients with head and neck cancer.

    PubMed

    Lee, Yu; Lin, Pao-Yen; Chien, Chih-Yen; Fang, Fu-Min

    2015-02-01

    The purpose of this study is to examine the prevalence and risk factors of depressive disorder in caregivers of patients with head and neck cancer. Study subjects were recruited from a multidisciplinary outpatient clinic for head and neck cancer in a medical center from February to July 2012. Caregivers of patients with head and neck cancer were enrolled and assessed using the Structured Clinical Interview for the DSM-IV, Clinician Version, the Short Form 36 Health Survey, and the Family APGAR index. The main aim of the study was to examine the difference in demographic data and clinical characteristics between the caregivers with and without depressive disorders. In addition, a stepwise forward model of logistic regression was used to test the possible risk factors. One hundred and forty-three caregivers were included in the study. The most prevalent psychiatric disorder was depressive disorder (14.7%), followed by adjustment disorder (13.3%). Nearly one-third of the caregivers had a psychiatric diagnosis. By using logistic regression analysis, it was found that unemployment (odds ratio (OR) = 3.16; 95% CI, 1.04-9.68), lower social functioning (OR = 1.43; 95% CI, 1.18-1.72), and lower educational level (OR = 1.16; 95% CI, 1.01-1.34) were significant risk factors for the depressive disorder. The clinical implication of our results is the value of using the standardized structured interview for early diagnosis of depressive disorder in caregivers of head and neck cancer patients. Early screening and management of depression in these caregivers will raise their quality of life and capability to care patients. Copyright © 2014 John Wiley & Sons, Ltd.

  14. The Role of Prothrombotic Factors in the Ocular Manifestations of Abusive and Non-Abusive Head Trauma: A Feasibility Study

    ERIC Educational Resources Information Center

    Yu, Anna; Stephens, Derek; Feldman, Brian M.; Parkin, Patricia C.; Kahr, Walter H. A.; Brandao, Leonardo R.; Shouldice, Michelle; Levin, Alex V.

    2012-01-01

    Objectives: Retinal hemorrhage is a cardinal manifestation of abusive head injury. Thrombophilia is relatively common in the general population and in adults can be associated with retinal hemorrhage. The specificity of retinal hemorrhage for abusive head trauma in the presence of prothrombotic factors, in particular following non-abusive head…

  15. The Role of Prothrombotic Factors in the Ocular Manifestations of Abusive and Non-Abusive Head Trauma: A Feasibility Study

    ERIC Educational Resources Information Center

    Yu, Anna; Stephens, Derek; Feldman, Brian M.; Parkin, Patricia C.; Kahr, Walter H. A.; Brandao, Leonardo R.; Shouldice, Michelle; Levin, Alex V.

    2012-01-01

    Objectives: Retinal hemorrhage is a cardinal manifestation of abusive head injury. Thrombophilia is relatively common in the general population and in adults can be associated with retinal hemorrhage. The specificity of retinal hemorrhage for abusive head trauma in the presence of prothrombotic factors, in particular following non-abusive head…

  16. Factors influencing repeated seed movements by scatter-hoarding rodents in an alpine forest

    PubMed Central

    Wang, Bo; Chen, Jin; Corlett, Richard T.

    2014-01-01

    Scatter-hoarding rodents are effective dispersal agents for many plant species. Several studies have shown that rodents repeatedly re-cache seeds. The re-caching process often has a significant impact on final seedling establishment, but the factors determining its occurrence are poorly understood. In this study, we followed the fate of 3564 artificial seeds that varied in size, nutrient content and tannin content. Seeds cached closer to their original releasing plots were more likely to be re-cached, and to a further distance. Larger seeds were more likely to be re-cached than smaller ones, while nutrient and tannin content had little effect. Most plant species that depend on scatter-hoarding rodents for seed dispersal bear relatively large seeds, and large seeds are usually more likely to be dispersed and to establish seedlings, suggesting that the caching preferences of scatter-hoarding rodents may have played an important role in the evolution of large seeds. PMID:24759374

  17. Factors influencing repeated seed movements by scatter-hoarding rodents in an alpine forest.

    PubMed

    Wang, Bo; Chen, Jin; Corlett, Richard T

    2014-04-24

    Scatter-hoarding rodents are effective dispersal agents for many plant species. Several studies have shown that rodents repeatedly re-cache seeds. The re-caching process often has a significant impact on final seedling establishment, but the factors determining its occurrence are poorly understood. In this study, we followed the fate of 3564 artificial seeds that varied in size, nutrient content and tannin content. Seeds cached closer to their original releasing plots were more likely to be re-cached, and to a further distance. Larger seeds were more likely to be re-cached than smaller ones, while nutrient and tannin content had little effect. Most plant species that depend on scatter-hoarding rodents for seed dispersal bear relatively large seeds, and large seeds are usually more likely to be dispersed and to establish seedlings, suggesting that the caching preferences of scatter-hoarding rodents may have played an important role in the evolution of large seeds.

  18. Head lice infestation in schoolchildren and related factors in Mafraq governorate, Jordan.

    PubMed

    Mohammed, A L Bashtawy

    2012-02-01

    Little is known about the effect of socioeconomic status on the infestation by head lice in schoolchildren in Jordan. A cross-sectional school-based study was conducted from December 2009 to February 2010. A list of all primary schools in Mafraq governorate was obtained (394 primary schools). Eight primary schools were randomly selected (four male schools and four female schools). Data were collected by five well-trained nurses. Hair was examined for head lice as well as for eggs/nits. Analysis of data was conducted by using SPSS software version 16. The chi-square test was used to assess statistical significance of subgroup differences in the prevalence of infestation, and multivariate logistic regression was used to control for potential confounding. Out of 1550 primary schoolchildren screened, 412 (26.6%) were infected with lice, 163 (19.6%) boys and 249 (34.7%) girls. The results showed significant variations in head lice infestation by factors such as gender, age, and socioeconomic variables (family income, father's education, mother's education, number of rooms, number of siblings younger than 15 years, frequency of hair washing per week, and bathing per week). There was no significant variation in lice infestation with parents' occupation (P > 0.05). Socioeconomic status is a major factor influencing the occurrence of pediculosis capitis among schoolchildren in both sexes. Improving standards of living and personal hygiene might significantly reduce pediculosis capitis in schoolchildren in Jordan. © 2012 The International Society of Dermatology.

  19. Factors Associated With External and Internal Lymphedema in Patients With Head-and-Neck Cancer

    SciTech Connect

    Deng Jie; Ridner, Sheila H.; Dietrich, Mary S.; Wells, Nancy; Wallston, Kenneth A.; Sinard, Robert J.; Cmelak, Anthony J.; Murphy, Barbara A.

    2012-11-01

    Purpose: The purpose of this study was to examine factors associated with the presence of secondary external and internal lymphedema in patients with head-and-neck cancer (HNC). Methods and Materials: The sample included 81 patients {>=}3 months after HNC treatment. Physical and endoscopic examinations were conducted to determine if participants had external, internal, and/or combined head-and-neck lymphedema. Logistic regression analysis was used to examine the factors associated with the presence of lymphedema. Results: The following factors were statistically significantly associated with presence of lymphedema: (1) location of tumor associated with presence of external (P=.009) and combined lymphedema (P=.032); (2) time since end of HNC treatment associated with presence of external (P=.004) and combined lymphedema (P=.005); (3) total dosage of radiation therapy (P=.010) and days of radiation (P=.017) associated with the presence of combined lymphedema; (4) radiation status of surgical bed was associated with the presence of internal lymphedema, including surgery with postoperative radiation (P=.030) and (salvage) surgery in the irradiated field (P=.008); and (5) number of treatment modalities associated with external (P=.002), internal (P=.039), and combined lymphedema (P=.004). No demographic, health behavior-related, or comorbidity factors were associated with the presence of lymphedema in the sample. Conclusions: Select tumor and treatment parameters are associated with increased occurrence of lymphedema in patients with HNC. Larger and longitudinal studies are needed to identify adjusted effects and causative risk factors contributing to the development of lymphedema in patients with HNC.

  20. New experimental method for lidar overlap factor using a CCD side-scatter technique.

    PubMed

    Wang, Zhenzhu; Tao, Zongming; Liu, Dong; Wu, Decheng; Xie, Chenbo; Wang, Yingjian

    2015-04-15

    In theory, lidar overlap factor can be derived from the difference between the particle backscatter coefficient retrieved from lidar elastic signal without overlap correction and the actual particle backscatter coefficient, which can be obtained by other measured techniques. The side-scatter technique using a CCD camera is testified to be a powerful tool to detect the particle backscatter coefficient in near ground layer during night time. A new experiment approach to determine the overlap factor for vertically pointing lidar is presented in this study, which can be applied to Mie lidars. The effect of overlap factor on Mie lidar is corrected by an iteration algorithm combining the retrieved particle backscatter coefficient using CCD side-scatter method and Fernald method. This method has been successfully applied to Mie lidar measurements during a routine campaign, and the comparison of experimental results in different atmosphere conditions demonstrated that this method is available in practice.

  1. X-ray coherent scattering form factors of tissues, water and plastics using energy dispersion

    NASA Astrophysics Data System (ADS)

    King, B. W.; Landheer, K. A.; Johns, P. C.

    2011-07-01

    A key requirement for the development of the field of medical x-ray scatter imaging is accurate characterization of the differential scattering cross sections of tissues and phantom materials. The coherent x-ray scattering form factors of five tissues (fat, muscle, liver, kidney, and bone) obtained from butcher shops, four plastics (polyethylene, polystyrene, lexan (polycarbonate), nylon), and water have been measured using an energy-dispersive technique. The energy-dispersive technique has several improvements over traditional diffractometer measurements. Most notably, the form factor is measured on an absolute scale with no need for scaling factors. Form factors are reported in terms of the quantity x = λ-1sin (θ/2) over the range 0.363-9.25 nm-1. The coherent form factors of muscle, liver, and kidney resemble those of water, while fat has a narrower peak at lower x, and bone is more structured. The linear attenuation coefficients of the ten materials have also been measured over the range 30-110 keV and parameterized using the dual-material approach with the basis functions being the linear attenuation coefficients of polymethylmethacrylate and aluminum.

  2. The Proton Coulomb Form Factor from Polarized Inclusive e-p Scattering

    SciTech Connect

    Harris, Christopher Matthew

    2001-05-01

    The proton form factors provide information on the fundamental properties of the proton and provide a test for models based on QCD. In 1998 at Jefferson Lab (JLAB) in Newport News, VA, experiment E93026 measured the inclusive e-p scattering cross section from a polarized ammonia (15NH3) target at a four momentum transfer squared of Q2 = 0.5 (GeV/c)2. Longitudinally polarized electrons were scattered from the polarized target and the scattered electron was detected. Data has been analyzed to obtain the asymmetry from elastically scattered electrons from hydrogen in 15NH3. The asymmetry, Ap, has been used to determine the proton elastic form factor GEp. The result is consistent with the dipole model and data from previous experiments. However, due to the choice of kinematics, the uncertainty in the measurement is large.

  3. Human epidermal growth factor receptor 3 in head and neck squamous cell carcinomas.

    PubMed

    Rysman, Bénédicte; Mouawad, François; Gros, Abigaëlle; Lansiaux, Amélie; Chevalier, Dominique; Meignan, Samuel

    2016-04-01

    Human epidermal growth factor receptor 3 (HER3) is a member of the human epidermal growth factor receptor (HER) family. The main characteristic of HER3 is that it does not possess tyrosine kinase activity, unlike other HERs. The role of HER3 in tumorigenesis has now been recognized, particularly in head and neck squamous cell carcinomas (HNSCCs). Despite conflicting studies, HER3 was found to be overexpressed in HNSCC samples, and correlates with disease progression and poor survival, especially when it is coexpressed with other HERs. HER3 is a significant factor in HNSCC treatment resistance. Indeed, HER3 is a major mechanism described for cetuximab resistance because of modification of epidermal growth factor receptor (EGFR) internalization and by phosphotidylinositol-3-kinase (PI3K)/AKT signaling pathway activation. HER3 also affects resistance to tyrosine kinase inhibitors (TKIs) and thereby promotes treatment escape and radiotherapy resistance by activation of the survival signaling pathway. To counteract this, pharmacologic inhibitors of HER3 are currently in development and could significantly improve HNSCC treatment. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2412-E2418, 2016.

  4. The scatter factor signaling pathways as therapeutic associated target in cancer treatment.

    PubMed

    Accornero, P; Pavone, L M; Baratta, M

    2010-01-01

    Receptor tyrosine kinases (RTKs) are key regulators of critical cellular processes such as proliferation, differentiation, neo-vascularization, and tissue repair. In addition to their importance in the regulation of normal physiology, aberrant expression of certain RTKs has also been associated to the development and progression of many types of cancer. c-Met and RON are two RTKs with closely related sequences, structural homology, and similar functional properties. Both these receptors, once activated by their respective ligands, the Hepatocyte Growth Factor/Scatter Factor (HGF/SF1) and the Macrophage Stimulating Protein/Scatter Factor 2 (MSP/SF2), can induce cell migration, invasion and proliferation. Soon after its discovery in the mid-1980s, c-Met attracted a great interest because of its role in modulating cell motility. Moreover, the causal role for c-Met activating mutations in human cancer propelled an intensive drug discovery effort throughout academic institutions and pharmaceutical companies. While c-Met is now a well-accepted target for anticancer drug design, less is known about the role of RON in cancer and less has been done to target this receptor. In this review we will discuss the biological relevance of c-Met and RON, their deregulation in human cancers and the progress, so far, in identifying c-Met and RON signaling inhibitors. Finally, we will focus on the development of therapeutic strategies and drug efficacy studies based on interfering the scatter factor signaling pathways.

  5. Parity-Violating Electron Scattering and the Electric and Magnetic Strange Form Factors of the Nucleon

    SciTech Connect

    Armstrong, David S.; McKeown, Robert

    2012-11-01

    Measurement of the neutral weak vector form factors of the nucleon provides unique access to the strange quark content of the nucleon. These form factors can be studied using parity-violating electron scattering. A comprehensive program of experiments has been performed at three accelerator laboratories to determine the role of strange quarks in the electromagnetic form factors of the nucleon. This article reviews the remarkable technical progress associated with this program, describes the various methods used in the different experiments, and summarizes the physics results along with recent theoretical calculations.

  6. Vehicle Related Factors that Influence Injury Outcome in Head-On Collisions

    PubMed Central

    Blum, Jeremy J.; Scullion, Paul; Morgan, Richard M.; Digges, Kennerly; Kan, Cing-Dao; Park, Shinhee; Bae, Hanil

    2008-01-01

    This study specifically investigated a range of vehicle-related factors that are associated with a lower risk of serious or fatal injury to a belted driver in a head-on collision. This analysis investigated a range of structural characteristics, quantities that describes the physical features of a passenger vehicle, e.g., stiffness or frontal geometry. The study used a data-mining approach (classification tree algorithm) to find the most significant relationships between injury outcome and the structural variables. The algorithm was applied to 120,000 real-world, head-on collisions, from the National Highway Traffic Safety Administration’s (NHTSA’s) State Crash data files, that were linked to structural attributes derived from frontal crash tests performed as part of the USA New Car Assessment Program. As with previous literature, the analysis found that the heavier vehicles were correlated with lower injury risk to their drivers. This analysis also found a new and significant correlation between the vehicle’s stiffness and injury risk. When an airbag deployed, the vehicle’s stiffness has the most statistically significant correlation with injury risk. These results suggest that in severe collisions, lower intrusion in the occupant cabin associated with higher stiffness is at least as important to occupant protection as vehicle weight for self-protection of the occupant. Consequently, the safety community might better improve self-protection by a renewed focus on increasing vehicle stiffness in order to improve crashworthiness in head-on collisions. PMID:19026230

  7. Vehicle related factors that influence injury outcome in head-on collisions.

    PubMed

    Blum, Jeremy J; Scullion, Paul; Morgan, Richard M; Digges, Kennerly; Kan, Cing-Dao; Park, Shinhee; Bae, Hanil

    2008-10-01

    This study specifically investigated a range of vehicle-related factors that are associated with a lower risk of serious or fatal injury to a belted driver in a head-on collision. This analysis investigated a range of structural characteristics, quantities that describes the physical features of a passenger vehicle, e.g., stiffness or frontal geometry. The study used a data-mining approach (classification tree algorithm) to find the most significant relationships between injury outcome and the structural variables. The algorithm was applied to 120,000 real-world, head-on collisions, from the National Highway Traffic Safety Administration's (NHTSA's) State Crash data files, that were linked to structural attributes derived from frontal crash tests performed as part of the USA New Car Assessment Program. As with previous literature, the analysis found that the heavier vehicles were correlated with lower injury risk to their drivers. This analysis also found a new and significant correlation between the vehicle's stiffness and injury risk. When an airbag deployed, the vehicle's stiffness has the most statistically significant correlation with injury risk. These results suggest that in severe collisions, lower intrusion in the occupant cabin associated with higher stiffness is at least as important to occupant protection as vehicle weight for self-protection of the occupant. Consequently, the safety community might better improve self-protection by a renewed focus on increasing vehicle stiffness in order to improve crashworthiness in head-on collisions.

  8. Head, face and neck injury in youth rugby: incidence and risk factors.

    PubMed

    McIntosh, A S; McCrory, P; Finch, C F; Wolfe, R

    2010-02-01

    In this study, the incidence of head, neck and facial injuries in youth rugby was determined, and the associated risk factors were assessed. Data were extracted from a cluster randomised controlled trial of headgear with the football teams as the unit of randomisation. No effect was observed for headgear use on injury rates, and the data were pooled. General school and club-based community competitive youth rugby in the 2002 and 2003 seasons. Young male rugby union football players participating in under-13, under 15, under 18 and under 21 years competitions. Eighty-two teams participated in year 1 and 87 in year 2. Injury rates for all body regions combined, head, neck and face calculated for game and missed game injuries. 554 head, face and neck injuries were recorded within a total of 28 902 h of rugby game exposure. Level of play and player position were related to injury risk. Younger players had the lowest rates of injury; forwards, especially the front row had the highest rate of neck injury; and inside backs had the highest rate of injuries causing the player to miss a game. Contact events, including the scrum and tackle, were the main events leading to injury. Injury prevention must focus on the tackle and scrum elements of a youth rugby game.

  9. [Impact of spermatozoid head anomalies as predictor factor of non-determined infertility].

    PubMed

    Ambe, Alberto Kably; Mondragón, Esperanza Carballo; González, Sergio Estévez

    2008-03-01

    To evaluate fertilization and pregnancy rates, and pregnancy outcome in women diagnosed with non-determined infertility, and its correlation with sperm head morphology anomalies. Retrospective study (ANOVA) including 126 patients diagnosed with non-determined infertility, attended from January 2002 to December 2006, admitted to embryo transference fertilization program, both conventional in vitro and intracytoplasmatic sperm injection. Spermatic morphology was analyzed in accordance with Kruger's strict criterion. All of patients had spermatic morphology higher than 5%, with 7.17% average. They were divided into three groups, in accordance with sperm head morphology anomalies percentage: group 1, less than 30%; group 2, 31 to 39%, and group 3, more than 40%. All of them had oocyte insemination: half conventional in vitro and half intracytoplasmatic sperm injection. Group 1 had higher percentage of fertilization, over groups 2 and 3 (65.44, 49.5 and 57.23%, respectively; p = 0.002). Abortion numbers showed meaningful differences too; group 1 had no abortions, meanwhile groups 2 and 3 had 30.77 and 22.22%, respectively. Evaluation of sperm head morphology anomalies must be a prognostic factor in pregnancy evolution, in women with nondetermined infertility.

  10. A human factors approach to snowsport safety: Novel research on pediatric participants' behaviors and head injury risk.

    PubMed

    Dickson, Tracey J; Trathen, Stephen; Waddington, Gordon; Terwiel, F Anne; Baltis, Daniel

    2016-03-01

    This study applied a human factors approach to snowsport resort systems to contribute to the understanding of the incidence and severity of pediatric snowsport head accelerations. Previous research indicates low magnitude head accelerations are common among snowsport participants. This study adds to the knowledge of snowsport safety by measuring aspects of participants' snowsport behavior and linking this with head acceleration data. School-aged students (n = 107) wore telemetry-fitted helmets and Global Positioning System (GPS) devices during snowsport activity. Data was collected over 159 sessions (total hours 701). Head accelerations recorded by the telemetry units were compared with GPS-generated data. This study found speeds attained normally exceed the testing rating for which helmets are designed; lower rates of head accelerations compared to earlier studies and that when head accelerations did occur they were generally below the threshold for concussions. Pediatric snowsport head accelerations are rare and are generally of low magnitude. Those most at risk of a head acceleration >40 g were male snowboarders. Given the recorded speeds in first time participants, increased targeting of novice snowsport participants to encourage education about the use of protective equipment, including helmets, is warranted. Post event recall was not a good indicator of having experienced a head impact. Consideration should be given to raising the standard design speed testing for snowsport helmet protective devices to reflect actual snowsport behaviors. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  11. Investigation of scattering coefficients and anisotropy factors of human cancerous and normal prostate tissues using Mie theory

    NASA Astrophysics Data System (ADS)

    Pu, Yang; Chen, Jun; Wang, Wubao

    2014-02-01

    The scattering coefficient, μs, the anisotropy factor, g, the scattering phase function, p(θ), and the angular dependence of scattering intensity distributions of human cancerous and normal prostate tissues were systematically investigated as a function of wavelength, scattering angle and scattering particle size using Mie theory and experimental parameters. The Matlab-based codes using Mie theory for both spherical and cylindrical models were developed and applied for studying the light propagation and the key scattering properties of the prostate tissues. The optical and structural parameters of tissue such as the index of refraction of cytoplasm, size of nuclei, and the diameter of the nucleoli for cancerous and normal human prostate tissues obtained from the previous biological, biomedical and bio-optic studies were used for Mie theory simulation and calculation. The wavelength dependence of scattering coefficient and anisotropy factor were investigated in the wide spectral range from 300 nm to 1200 nm. The scattering particle size dependence of μs, g, and scattering angular distributions were studied for cancerous and normal prostate tissues. The results show that cancerous prostate tissue containing larger size scattering particles has more contribution to the forward scattering in comparison with the normal prostate tissue. In addition to the conventional simulation model that approximately considers the scattering particle as sphere, the cylinder model which is more suitable for fiber-like tissue frame components such as collagen and elastin was used for developing a computation code to study angular dependence of scattering in prostate tissues. To the best of our knowledge, this is the first study to deal with both spherical and cylindrical scattering particles in prostate tissues.

  12. Baryon scattering at high energies: wave function, impact factor, and gluon radiation

    NASA Astrophysics Data System (ADS)

    Bartels, J.; Motyka, L.

    2008-05-01

    The scattering of a baryon consisting of three massive quarks is investigated in the high energy limit of perturbative QCD. A model of a relativistic proton-like wave function, dependent on valence quark longitudinal and transverse momenta and on quark helicities, is proposed, and we derive the baryon impact factors for two, three and four t-channel gluons. We find that the baryonic impact factor can be written as a sum of three pieces: in the first one a subsystem consisting of two of the three quarks behaves very much like the quark antiquark pair in γ* scattering, whereas the third quark acts as a spectator. The second term belongs to the odderon, whereas in the third (C-even) piece all three quarks participate in the scattering. This term is new and has no analogue in γ* scattering. We also study the small x evolution of gluon radiation for each of these three terms. The first term follows the same pattern of gluon radiation as the γ*-initiated quark antiquark dipole, and, in particular, it contains the BFKL evolution followed by the 2→4 transition vertex (triple pomeron vertex). The odderon term is described by the standard BKP evolution, and the baryon couples to both known odderon solutions, the Janik Wosiek solution and the BLV solution. Finally, the t-channel evolution of the third term starts with a three-reggeized gluon state, which then, via a new 3→4 transition vertex, couples to the four-gluon (two-pomeron) state. We briefly discuss a few consequences of these findings, in particular the pattern of unitarization of high energy baryon scattering amplitudes.

  13. Pectoralis major myocutaneous flap for head and neck reconstruction: risk factors for fistula formation.

    PubMed

    Leite, A K N; de Matos, L L; Belli, M; Kulcsar, M A V; Cernea, C R; Garcia Brandão, L; Pinto, F R

    2014-12-01

    The pectoralis major myocutaneous flap (PMMF) is a safe and versatile flap used widely for head and neck cancer reconstructions, but one of the major and most feared complications is oro- or pharyngocutaneous fistula. Herein, we attempt to establish risk factors for fistula formation in reconstructions of mucosal defects in the head and neck using PMMF through retrospective analysis of PMMF performed during 3 years at a single institution, with a total of 84 procedures. There were 69 men and 15 women, with a mean age of 59.5 years. There were 15 cases of partial flap loss, two total flap losses and 31 fistulas. The independent risk factors for fistula formation were preoperative serum hemoglobin < 13 g/dl, preoperative serum albumin < 3.4 g/dl and hypopharynx reconstruction. The PMMF is still a very useful flap and this is the first multivariate analysis analysing risk factors for fistula formation. These findings are helpful in selecting patients with elevated risk of fistula formation, and therefore preventive measures can be undertaken to avoid potentially serious complications.

  14. Female hormonal and reproductive factors and head and neck squamous cell carcinoma risk.

    PubMed

    Langevin, Scott M; Grandis, Jennifer R; Taioli, Emanuela

    2011-11-28

    Men are much more likely than women to develop head and neck squamous cell carcinoma (HNSCC), a discrepancy that is insufficiently explained by gender differences in smoking and alcohol consumption. It has been hypothesized that differential hormonal exposures may account for some of this risk but thus far the literature on female reproductive factors and HNSCC risk has been sparse. To address the association of HNSCC with female hormonal and reproductive factors, a case-control study was conducted on 149 women with head and neck cancer and 158 controls. After adjusting for potential confounding, postmenopausal women using female hormones for more than 5 years showed a borderline protective effect for HNSCC (adjusted OR = 0.47, 95% CI: 0.20-1.08), with a borderline trend across duration of use categories (P = 0.06). There was no association of HNSCC with age at menarche, hysterectomy/oophorectomy status, oral contraceptive use, history of fertility medication, or number of pregnancies, parity, or age at first pregnancy or live birth. The findings of this study do not support a link between HNSCC and reproductive factors, although the borderline association with HRT warrants further investigation.

  15. Factors affecting duration of gastrostomy tube retention in survivors following treatment for head and neck cancer.

    PubMed

    Blanchford, H; Hamilton, D; Bowe, I; Welch, S; Kumar, R; Moor, J W; Welch, A R; Paleri, V

    2014-03-01

    Many patients treated for head and neck cancer require nutritional support, which is often delivered using a gastrostomy tube. It is difficult to predict which patients will retain their gastrostomy tube in the long term. This study aimed to identify the factors which affect the duration of gastrostomy tube retention. In this retrospective study, 151 consecutive patients from one centre were audited. All patients had a mucosal tumour of the head and neck, and underwent gastrostomy tube insertion between 2003 and 2007. There were near-complete data sets for 132 patients. The gastrostomy tube was retained in survivors (n = 66) for a mean of 21.3 months and in non-survivors (n = 66) for 11.9 months. Univariate analysis showed that co-morbidity was the only factor which significantly increased duration of gastrostomy tube retention in survivors (p = 0.041). Co-morbidity alone was associated with a significant increase in gastrostomy tube retention. It is suggested that co-morbidity be included as a variable in future relevant research. Co-morbidity should also be considered when counselling patients about their long-term function following cancer treatment. Gastrostomy tube retention is likely to be affected by many factors, with few single variables having importance independently.

  16. Test of factorization in diffractive deep inelastic scattering and photoproduction at HERA

    SciTech Connect

    Polifka, Richard

    2015-04-10

    The QCD factorization theorem in diffraction is tested by comparing diffractive jet production data to QCD predictions based on fits to inclusive diffractive cross section data. H1 measured dijet production with a leading proton detected in the Very Forward Proton Spectrometer (VFPS), both in deep-inelastic scattering and in photoproduction. The DIS measurements are complemented by measurements of dijet production with an associated rapidity gap and in a data sample selected with a leading proton in the Forward Proton Spectrometer (FPS)

  17. Reliability-Based Scatter Factors. Volume 1. Theoretical and Empirical Results

    DTIC Science & Technology

    1978-03-01

    of S is given by s5 n FS(s) = [ s (6)(rn/n) + sCX In deriving Eq. 6, the fact has been used that 2n(ý/8)a is distributed as X2 with 2n degrees of...summarize such observations for selected values of R, a and n. The last column in Tables 1 - 3 lists the value of Freudenthal’s scatter factor

  18. Atomic Scattering Factor of the ASTRO-H (Hitomi) SXT Reflector Around the Gold's L Edges

    NASA Technical Reports Server (NTRS)

    Kikuchi, Naomichi; Kurashima, Sho; Ishida, Manabu; Iizuka, Ryo; Maeda, Yoshitomo; Hayashi, Takayuki; Okajima, Takashi; Matsumoto, Hironori; Mitsubishi, Ikuyuki; Saji, Shigetaka

    2016-01-01

    The atomic scattering factor in the energy range of 11.2 - 15.4 keV for the ASTRO-H Soft X-ray Telescope (SXT) is reported. The large effective area of the SXT makes use of photon spectra above 10 keV viable, unlike most other X-ray satellites with total-reflection mirror optics. Presence of gold's L-edges in the energy band is a major issue, as it complicates the function of the effective area. In order to model the area, the reflectivity measurements in the 11.2 - 15.4 keV band with the energy pitch of 0.4 - 0.7 eV were made in the synchrotron beam-line Spring-8 BL01B1. We obtained atomic scattering factors f1 and f2 by the curve fitting to the reflectivities of our witness sample. The edges associated with the L-I, II, and III transitions are identified, of which the depths are found to be roughly 60 shallower than those expected from the Henkes atomic scattering factor.

  19. Construct Validity of WAIS-R Factors: Neuropsychological Test Correlates in Adults Referred for Evaluation of Possible Head Injury.

    ERIC Educational Resources Information Center

    Sherman, Elisabeth M. S.; And Others

    1995-01-01

    A 3-factor solution of the Wechsler Adult Intelligence Scale--Revised (WAIS-R) in 260 adults with suspected head injury suggested relatively good construct validity for the factors, based on correlations with neuropsychological tests. Findings are discussed in terms of the multidimensional nature of neuropsychological tests and WAIS-R factors.…

  20. Water equivalent path length calculations using scatter-corrected head and neck CBCT images to evaluate patients for adaptive proton therapy

    NASA Astrophysics Data System (ADS)

    Kim, Jihun; Park, Yang-Kyun; Sharp, Gregory; Busse, Paul; Winey, Brian

    2017-01-01

    Proton therapy has dosimetric advantages due to the well-defined range of the proton beam over photon radiotherapy. When the proton beams, however, are delivered to the patient in fractionated radiation treatment, the treatment outcome is affected by delivery uncertainties such as anatomic change in the patient and daily patient setup error. This study aims at establishing a method to evaluate the dosimetric impact of the anatomic change and patient setup error during head and neck proton therapy. Range variations due to the delivery uncertainties were assessed by calculating water equivalent path length (WEPL) to the distal edge of tumor volume using planning CT and weekly treatment cone-beam CT (CBCT) images. Specifically, mean difference and root mean squared deviation (RMSD) of the distal WEPLs were calculated as the weekly range variations. To accurately calculate the distal WEPLs, an existing CBCT scatter correction algorithm was used. An automatic rigid registration was used to align the planning CT and treatment CBCT images, simulating a six degree-of-freedom couch correction at treatments. The authors conclude that the dosimetric impact of the anatomic change and patient setup error was reasonably captured in the differences of the distal WEPL variation with a range calculation uncertainty of 2%. The proposed method to calculate the distal WEPL using the scatter-corrected CBCT images can be an essential tool to decide the necessity of re-planning in adaptive proton therapy.

  1. An approximate factorization method for inverse medium scattering with unknown buried objects

    NASA Astrophysics Data System (ADS)

    Qu, Fenglong; Yang, Jiaqing; Zhang, Bo

    2017-03-01

    This paper is concerned with the inverse problem of scattering of time-harmonic acoustic waves by an inhomogeneous medium with different kinds of unknown buried objects inside. By constructing a sequence of operators which are small perturbations of the far-field operator in a suitable way, we prove that each operator in this sequence has a factorization satisfying the Range Identity. We then develop an approximate factorization method for recovering the support of the inhomogeneous medium from the far-field data. Finally, numerical examples are provided to illustrate the practicability of the inversion algorithm.

  2. Prospects for using coherent elastic neutrino-nucleus scattering to measure the nuclear neutron form factor

    NASA Astrophysics Data System (ADS)

    Patton, Kelly; McLaughlin, Gail; Scholberg, Kate; Engel, Jon; Schunck, Nicolas

    2017-01-01

    Coherent elastic neutrino-nucleus scattering is a potential probe of nuclear neutron form factors. We show that the neutron root-mean-square (RMS) radius can be measured with tonne-scale detectors of argon, germanium, or xenon. In addition, the fourth moment of the neutron distribution can be studied experimentally using this method. The impacts of both detector size and detector shape uncertainty on such a measurement were considered. The important limiting factor was found to be the detector shape uncertainty. In order to measure the neutron RMS radius to 5%, comparable to current experimental uncertainties, the detector shape uncertainty needs to be known to 1% or better.

  3. Proton form factors and two-photon exchange in elastic electron-proton scattering

    SciTech Connect

    Nikolenko, D. M.; Arrington, J.; Barkov, L. M.; Vries, H. de; Gauzshtein, V. V.; Golovin, R. A.; Gramolin, A. V.; Dmitriev, V. F.; Zhilich, V. N.; Zevakov, S. A.; Kaminsky, V. V.; Lazarenko, B. A.; Mishnev, S. I.; Muchnoi, N. Yu.; Neufeld, V. V.; Rachek, I. A.; Sadykov, R. Sh.; Stibunov, V. N.; Toporkov, D. K.; Holt, R. J.; and others

    2015-05-15

    Proton electromagnetic form factors are among the most important sources of information about the internal structure of the proton. Two different methods for measuring these form factors, the method proposed by Rosenbluth and the polarization-transfer method, yield contradictory results. It is assumed that this contradiction can be removed upon taking into account the hard part of the contribution of two-photon exchange to the cross section for elastic electron-proton scattering. This contribution can measured experimentally via a precision comparison of the cross sections for the elastic scattering of positrons and electrons on protons. Such a measurement, performed at the VEPP-3 storage ring in Novosibirsk at the beam energies of 1.6 and 1.0 GeV for positron (electron) scattering angles in the ranges of θ{sub e} = 15°–25° and 55°–75° in the first case and in the range of θ{sub e} = 65°–105° in the second case is described in the present article. Preliminary results of this experiment and their comparison with theoretical predictions are described.

  4. Towards a Resolution of the Proton Form Factor Problem: New Electron and Positron Scattering Data

    DOE PAGES

    Adikaram, D.; Rimal, D.; Weinstein, L. B.; ...

    2015-02-10

    There is a significant discrepancy between the values of the proton electric form factor, GpE, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of GpE from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (epsilon) and momentummore » transfer (Q2) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ε at Q2=1.45 GeV2. This measurement is consistent with the size of the form factor discrepancy at Q2≈1.75 GeV2 and with hadronic calculations including nucleon and Delta intermediate states, which have been shown to resolve the discrepancy up to 2-3 GeV2.« less

  5. Towards a Resolution of the Proton Form Factor Problem: New Electron and Positron Scattering Data

    SciTech Connect

    Adikaram, D.; Rimal, D.; Weinstein, L. B.; Raue, B.; Khetarpal, P.; Bennett, R.; Arrington, J.; Brooks, W.; Adhikari, K.; Afanasev, A.; Amaryan, M.; Anderson, M.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A.; Bono, J.; Boiarinov, S.; Briscoe, W.; Burkert, V.; Carman, D.; Careccia, S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dodge, G.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J.; Fradi, A.; Garillon, B.; Gilfoyle, G.; Giovanetti, K.; Girod, F.; Goetz, J.; Gohn, W.; Golovatch, E.; Gothe, R.; Griffioen, K.; Guegan, B.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S.; Hyde, C. E.; Ilieva, Y.; Ireland, D.; Ishkhanov, B.; Jenkins, D.; Jiang, H.; Jo, H.; Joo, K.; Joosten, S.; Kalantarians, N.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F.; Koirala, S.; Kubarovsky, V.; Kuhn, S.; Livingston, K.; Lu, H.; MacGregor, I.; Markov, N.; Mattione, P.; Mayer, M.; McKinnon, B.; Mestayer, M.; Meyer, C.; Mirazita, M.; Mokeev, V.; Montgomery, R.; Moody, C.; Moutarde, H.; Movsisyan, A.; Camacho, C. Munoz; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Osipenko, M.; Ostrovidov, A.; Park, K.; Pasyuk, E.; Pisano, S.; Pogorelko, O.; Price, J.; Procureur, S.; Prok, Y.; Protopopescu, D.; Puckett, A.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabati, F.; Salgado, C.; Schott, D.; Schumacher, R.; Seder, E.; Sharabian, Y.; Simonyan, A.; Skorodumina, I.; Smith, E.; Smith, G.; Sober, D.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tian, Ye; Trivedi, A.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N.; Watts, D.; Wei, X.; Wood, M.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z.; Zonta, I.

    2015-02-10

    There is a significant discrepancy between the values of the proton electric form factor, GpE, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of GpE from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (epsilon) and momentum transfer (Q2) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ε at Q2=1.45 GeV2. This measurement is consistent with the size of the form factor discrepancy at Q2≈1.75 GeV2 and with hadronic calculations including nucleon and Delta intermediate states, which have been shown to resolve the discrepancy up to 2-3 GeV2.

  6. Towards a resolution of the proton form factor problem: new electron and positron scattering data.

    PubMed

    Adikaram, D; Rimal, D; Weinstein, L B; Raue, B; Khetarpal, P; Bennett, R P; Arrington, J; Brooks, W K; Adhikari, K P; Afanasev, A V; Amaryan, M J; Anderson, M D; Anefalos Pereira, S; Avakian, H; Ball, J; Battaglieri, M; Bedlinskiy, I; Biselli, A S; Bono, J; Boiarinov, S; Briscoe, W J; Burkert, V D; Carman, D S; Careccia, S; Celentano, A; Chandavar, S; Charles, G; Colaneri, L; Cole, P L; Contalbrigo, M; Crede, V; D'Angelo, A; Dashyan, N; De Vita, R; De Sanctis, E; Deur, A; Djalali, C; Dodge, G E; Dupre, R; Egiyan, H; El Alaoui, A; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fegan, S; Filippi, A; Fleming, J A; Fradi, A; Garillon, B; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Gohn, W; Golovatch, E; Gothe, R W; Griffioen, K A; Guegan, B; Guidal, M; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Harrison, N; Hattawy, M; Hicks, K; Holtrop, M; Hughes, S M; Hyde, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Jenkins, D; Jiang, H; Jo, H S; Joo, K; Joosten, S; Kalantarians, N; Keller, D; Khandaker, M; Kim, A; Kim, W; Klein, A; Klein, F J; Koirala, S; Kubarovsky, V; Kuhn, S E; Livingston, K; Lu, H Y; MacGregor, I J D; Markov, N; Mattione, P; Mayer, M; McKinnon, B; Mestayer, M D; Meyer, C A; Mirazita, M; Mokeev, V; Montgomery, R A; Moody, C I; Moutarde, H; Movsisyan, A; Camacho, C Munoz; Nadel-Turonski, P; Niccolai, S; Niculescu, G; Osipenko, M; Ostrovidov, A I; Park, K; Pasyuk, E; Peña, C; Pisano, S; Pogorelko, O; Price, J W; Procureur, S; Prok, Y; Protopopescu, D; Puckett, A J R; Ripani, M; Rizzo, A; Rosner, G; Rossi, P; Roy, P; Sabatié, F; Salgado, C; Schott, D; Schumacher, R A; Seder, E; Sharabian, Y G; Simonyan, A; Skorodumina, I; Smith, E S; Smith, G D; Sober, D I; Sokhan, D; Sparveris, N; Stepanyan, S; Stoler, P; Strauch, S; Sytnik, V; Taiuti, M; Tian, Ye; Trivedi, A; Ungaro, M; Voskanyan, H; Voutier, E; Walford, N K; Watts, D P; Wei, X; Wood, M H; Zachariou, N; Zana, L; Zhang, J; Zhao, Z W; Zonta, I

    2015-02-13

    There is a significant discrepancy between the values of the proton electric form factor, G(E)(p), extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of G(E)(p) from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (ϵ) and momentum transfer (Q(2)) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ϵ at Q(2)=1.45  GeV(2). This measurement is consistent with the size of the form factor discrepancy at Q(2)≈1.75  GeV(2) and with hadronic calculations including nucleon and Δ intermediate states, which have been shown to resolve the discrepancy up to 2-3  GeV(2).

  7. Towards a Resolution of the Proton Form Factor Problem: New Electron and Positron Scattering Data

    NASA Astrophysics Data System (ADS)

    Adikaram, D.; Rimal, D.; Weinstein, L. B.; Raue, B.; Khetarpal, P.; Bennett, R. P.; Arrington, J.; Brooks, W. K.; Adhikari, K. P.; Afanasev, A. V.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A. S.; Bono, J.; Boiarinov, S.; Briscoe, W. J.; Burkert, V. D.; Carman, D. S.; Careccia, S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dodge, G. E.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J. A.; Fradi, A.; Garillon, B.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guegan, B.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S. M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Jenkins, D.; Jiang, H.; Jo, H. S.; Joo, K.; Joosten, S.; Kalantarians, N.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Koirala, S.; Kubarovsky, V.; Kuhn, S. E.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; Mattione, P.; Mayer, M.; McKinnon, B.; Mestayer, M. D.; Meyer, C. A.; Mirazita, M.; Mokeev, V.; Montgomery, R. A.; Moody, C. I.; Moutarde, H.; Movsisyan, A.; Camacho, C. Munoz; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Peña, C.; Pisano, S.; Pogorelko, O.; Price, J. W.; Procureur, S.; Prok, Y.; Protopopescu, D.; Puckett, A. J. R.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Sharabian, Y. G.; Simonyan, A.; Skorodumina, I.; Smith, E. S.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tian, Ye; Trivedi, A.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.; CLAS Collaboration

    2015-02-01

    There is a significant discrepancy between the values of the proton electric form factor, GEp, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of GEp from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (ɛ ) and momentum transfer (Q2) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ɛ at Q2=1.45 GeV2 . This measurement is consistent with the size of the form factor discrepancy at Q2≈1.75 GeV2 and with hadronic calculations including nucleon and Δ intermediate states, which have been shown to resolve the discrepancy up to 2 - 3 GeV2 .

  8. The epidermal growth factor receptor (EGFR) in head and neck cancer: its role and treatment implications

    PubMed Central

    Zimmermann, Michel; Zouhair, Abderrahim; Azria, David; Ozsahin, Mahmut

    2006-01-01

    Epidermal growth factor receptor (EGFR) is a member of the ErbB family of receptors. Its stimulation by endogenous ligands, EGF or transforming growth factor-alpha (TGF-α) results in activation of intracellular tyrosine kinase, therefore, cell cycle progression. High levels of EGFR expression are correlated with poor prognosis and resistance to radiation therapy in a variety of cancers, mostly in squamous-cell carcinoma of the head and neck (SCCHN). Blocking the EGFR by a monoclonal antibody results in inhibition of the stimulation of the receptor, therefore, in inhibition of cell proliferation, enhanced apoptosis, and reduced angiogenesis, invasiveness and metastases. The EGFR is a prime target for new anticancer therapy in SCCHN, and other agents in development include small molecular tyrosine kinase inhibitors and antisense therapies. PMID:16722544

  9. Expression of Epithelial-Mesenchymal Transition Regulating Transcription Factors in Head and Neck Squamous Cell Carcinomas.

    PubMed

    Göppel, Juliane; Möckelmann, Nikolaus; Münscher, Adrian; Sauter, Guido; Schumacher, Udo

    2017-10-01

    The transcription factors Twist, Snail, Slug, ZEB1 and ZEB2 regulate epithelial-mesenchymal transition (EMT) and their expression has been associated with a poor prognosis in several cancer entities. The aim of this analysis was to investigate in parallel the expression of all of these transcription factors in head and neck squamous cell carcinomas (HNSCCs) in order to gain insight into their possible co-expression. Tumor tissue samples were immunohistochemically stained using antibodies against these transcription factors. The staining intensity and cellular distribution of the immunoreactivity was recorded. In general, transcription factor immunoreactivity was noted in the nucleus of both cancer and stromal cells. The highest immunoreactivity was observed for Twist. Snail, Slug, ZEB1 and ZEB2 showed a much lesser immunoreactivity in cancer cells and they were expressed independently from each other. Twist is the major transcription factor active in HNSCC; the other transcription factors of EMT seem to be of less importance in this tumor entity. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  10. Seven years of aerosol scattering hygroscopic growth measurements from SGP: Factors influencing water uptake: Aerosol Scattering Hygroscopic Growth

    DOE PAGES

    Jefferson, A.; Hageman, D.; Morrow, H.; ...

    2017-09-11

    Long-term measurements of changes in the aerosol scattering coefficient hygroscopic growth at the U.S. Department of Energy Southern Great Plains site provide information on the seasonal as well as size and chemical dependence of aerosol water uptake. Annual average sub-10 μm fRH values (the ratio of aerosol scattering at 85%/40% relative humidity (RH)) were 1.78 and 1.99 for the gamma and kappa fit algorithms, respectively. Our study found higher growth rates in the winter and spring seasons that correlated with a high aerosol nitrate mass fraction. fRH exhibited strong, but differing, correlations with the scattering Ångström exponent and backscatter fraction,more » two optical size-dependent parameters. The aerosol organic mass fraction had a strong influence on fRH. Increases in the organic mass fraction and absorption Ångström exponent coincided with a decrease in fRH. Similarly, fRH declined with decreases in the aerosol single scatter albedo. The uncertainty analysis of the fit algorithms revealed high uncertainty at low scattering coefficients and increased uncertainty at high RH and fit parameters values.« less

  11. Arterial injuries after penetrating brain injury in civilians: risk factors on admission head computed tomography.

    PubMed

    Bodanapally, Uttam K; Saksobhavivat, Nitima; Shanmuganathan, Kathirkamanathan; Aarabi, Bizhan; Roy, Ashis K

    2015-01-01

    The object of this study was to determine the specific CT findings of the injury profile in penetrating brain injury (PBI) that are risk factors related to intracranial arterial injuries. The authors retrospectively evaluated admission head CTs and accompanying digital subtraction angiography (DSA) studies from patients with penetrating trauma to the head in the period between January 2005 and December 2012. Two authors reviewed the CT images to determine the presence or absence of 30 injury profile variables and quantified selected variables. The CT characteristics in patients with and without arterial injuries were compared using univariate analysis, multivariate analysis, and receiver operating characteristic (ROC) curve analysis to determine the respective risk factors, independent predictors, and optimal threshold values for the continuous variables. Fifty-five patients were eligible for study inclusion. The risk factors for an intracranial arterial injury on univariate analysis were an entry wound over the frontobasal-temporal regions, a bihemispheric wound trajectory, a wound trajectory in proximity to the circle of Willis (COW), a subarachnoid hemorrhage (SAH), a higher SAH score, an intraventricular hemorrhage (IVH), and a higher IVH score. A trajectory in proximity to the COW was the best predictor of injury (OR 6.8 and p = 0.005 for all penetrating brain injuries [PBIs]; OR 13.3 and p = 0.001 for gunshot wounds [GSWs]). Significant quantitative variables were higher SAH and IVH scores. An SAH score of 3 (area under the ROC curve [AUC] for all PBIs 0.72; AUC for GSWs 0.71) and an IVH score of 3 (AUC for all PBIs 0.65; AUC for GSWs 0.65) could be used as threshold values to suggest an arterial injury. The risk factors identified may help radiologists suggest the possibility of arterial injury and prioritize neurointerventional consultation and potential DSA studies.

  12. First results from light scattering enhancement factor over central Indian Himalayas during GVAX campaign.

    PubMed

    Dumka, U C; Kaskaoutis, D G; Sagar, Ram; Chen, Jianmin; Singh, Narendra; Tiwari, Suresh

    2017-12-15

    The present work examines the influence of relative humidity (RH), physical and optical aerosol properties on the light-scattering enhancement factor [f(RH=85%)] over central Indian Himalayas during the Ganges Valley Aerosol Experiment (GVAX). The aerosol hygroscopic properties were measured by means of DoE/ARM (US Department of Energy, Atmospheric Radiation Measurement) mobile facility focusing on periods with the regular instrumental operation (November-December 2011). The measured optical properties include aerosol light-scattering (σsp) and absorption (σap) coefficients and the intensive parameters i.e., single scattering albedo (SSA), scattering Ångström exponent (SAE), absorption Ångström exponent (AAE) and light scattering enhancement factor (f(RH)=σsp(RH, λ)/σsp(RHdry, λ)). The measurements were separated for sub-micron (<1μm, D1μm) and particles with diameter<10μm (D10μm) in order to examine the influence of particle size on f(RH) and enhancement rate (γ). The particle size affects the aerosol hygroscopicity since mean f(RH=85%) of 1.27±0.12 and 1.32±0.14 are found for D10μm and D1μm, respectively. These f(RH) values are relatively low suggesting the enhanced presence of soot and carbonaceous particles from biomass burning activities, which is verified via backward air-mass trajectories. Similarly, the light-scattering enhancement rates are ~0.20 and 0.17 for the D1μm and D10μm particles, respectively. However, a general tendency for increasing f(RH) and γ is shown for higher σsp and σap values indicating the presence of rather aged smoke plumes, coated with industrial aerosols over northern India, with mean SSA, SAE and AAE values of 0.92, 1.00 and 1.15 respectively. On the other hand, a moderate-to-small dependence of f(RH) and γ on SAE, AAE, and SSA was observed for both particle sizes. Furthermore, f(RH) exhibits an increasing tendency with the number of cloud condensation nuclei (NCCN) indicating larger particle hygroscopicity

  13. MARTINI bead form factors for the analysis of time-resolved X-ray scattering of proteins.

    PubMed

    Niebling, Stephan; Björling, Alexander; Westenhoff, Sebastian

    2014-08-01

    Time-resolved small- and wide-angle X-ray scattering (SAXS and WAXS) methods probe the structural dynamics of proteins in solution. Although technologically advanced, these methods are in many cases limited by data interpretation. The calculation of X-ray scattering profiles is computationally demanding and poses a bottleneck for all SAXS/WAXS-assisted structural refinement and, in particular, for the analysis of time-resolved data. A way of speeding up these calculations is to represent biomolecules as collections of coarse-grained scatterers. Here, such coarse-graining schemes are presented and discussed and their accuracies examined. It is demonstrated that scattering factors coincident with the popular MARTINI coarse-graining scheme produce reliable difference scattering in the range 0 < q < 0.75 Å(-1). The findings are promising for future attempts at X-ray scattering data analysis, and may help to bridge the gap between time-resolved experiments and their interpretation.

  14. Human brain factor 1, a new member of the fork head gene family

    SciTech Connect

    Murphy, D.B.; Wiese, S.; Burfeind, P.

    1994-06-01

    Analysis of cDNA clones that cross-hybridized with the fork head domain of the rat HNF-3 gene family revealed 10 cDNAs from human fetal brain and human testis cDNA libraries containing this highly conserved DNA-binding domain. Three of these cDNAs (HFK1, HFK2, and HFK3) were further analyzed. The cDNA HFK1 has a length of 2557 nucleotides and shows strong homology at the nucleotide level (91.2%) to brain factor 1 (BF-1) from rat. The HFK1 cDNA codes for a putative 476 amino acid protein. The homology to BF-1 from rat in the coding region at the amino acid level is 87.5%. The fork head homologous region includes 111 amino acids starting at amino acid 160 and has a 97.5% homology to BF-1. Southern hybridization revealed that HFK1 is highly conserved among mammalian species and possibly birds. Northern analysis with total RNA from human tissues and poly(A)-rich RNA from mouse revealed a 3.2-kb transcript that is present in human and mouse fetal brain and in adult mouse brain. In situ hybridization with sections of mouse embryo and human fetal brain reveals that HFK1 expression is restricted to the neuronal cells in the telencepthalon, with strong expression being observed in the developing dentate gyrus and hippocampus. HFK1 was chromosomally localized by in situ hybridization to 14q12. The cDNA clones HFK2 and HFK3 were analyzed by restriction analysis and sequencing. HFK2 and HFK3 were found to be closely related but different from HFK1. Therefore, it would appear that HFK1, HFK2, HFK3, and BF-1 form a new fork head related subfamily. 33 refs., 6 figs.

  15. Factors Associated with Recurrence and Regional Adenopathy for Head and Neck Cutaneous Squamous Cell Carcinoma.

    PubMed

    Harris, Brianna N; Bayoumi, Ahmed; Rao, Shyam; Moore, Michael G; Farwell, D Gregory; Bewley, Arnaud F

    2017-03-01

    Objective Cutaneous squamous cell carcinoma (CSCC) is one of the most common malignancies worldwide. With advanced CSCC of the head and neck, there is conflicting evidence on what constitutes high-risk disease. Our objective is to evaluate which factors are predictive of recurrence and nodal spread and survival. Study Design Case series with chart review. Setting Tertiary academic institution. Subjects and Methods Patients with advanced head and neck CSCC treated with primary resection identified by chart review. Results A total of 212 patients met inclusion criteria, with a mean age of 70.4 years; 87.3% were men. Mean tumor diameter was 3.65 cm, with an average depth of invasion of 1.38 cm. The mean follow-up time was 35 months (median, 21.5), and over that period 67 recurrences were recorded, 49 of which were local. The 5-year Kaplan-Meier estimate of disease-free survival for the cohort was 53.2%. On Cox multivariate analysis, recurrent disease, perineural invasion (PNI), and poorly differentiated histology were independent predictors of recurrence. On multinomial logistic regression, patients with primary tumors on the ear, cheek, temple, or lip, as well as those with PNI, were more likely to present with nodal metastasis. Conclusion For advanced CSCCs of the head and neck, patients with recurrent disease, PNI, and poorly differentiated tumors are at highest risk for local recurrence. Patients with tumors or the ear, cheek, temple, or lip, as well as those with PNI, are at increased risk of harboring nodal disease.

  16. Measurement of coherent Debye-Waller factor in in vivo deuterated C-phycocyanin by inelastic neutron scattering.

    PubMed

    Bellissent-Funel, M C; Filabozzi, A; Chen, S H

    1997-04-01

    Quasielastic neutron scattering measurements of dry and 35% D2O hydrated amorphous protein powder of C-phycocyanin were made as a function of temperature ranging from 313K down to 100K. The protein is grown from blue-green algae cultured in D2O and is deuterated up to 99%. The scattering is thus dominated by coherent scattering. Within the best energy resolution of the time-of-flight instrument, which is 28 mueV FWHM, the scattering appears entirely elastic. For this reason we are able to extract a coherent Debye-Waller factor by making an independent measurement of the static structure factor. We observe a considerable difference in the q dependence of the Debye-Waller factor between the dry and hydrated proteins; furthermore, there is an interesting temperature dependence of the Debye-Waller factor that is quite different from that predicted for dense hard-sphere liquids.

  17. [Nutritional risk factors in patients with head and neck cancer in oncology care center Michoacan state].

    PubMed

    García Rojas Vázquez, L E; Trujano-Ramos, L A; Pérez-Rivera, E

    2013-01-01

    The head and neck cancer in Michoacán, Mexico, ranks as the third most common cancer and accounts for 12% of deaths. The increase in malnutrition in a patient with this disease has been associated with increased mortality. We studied prospectively 30 patients of both sexes, aged 18 years with head and neck cancer in the Cancer Care Center of Michoacan. In the evaluation period since August 2010 to August 2011. Formats were used VGS-Oncology (Subjective Global Assessment), NRS 2002 (Nutritional risk screen) and Guss (Gugging Swallowing Screen), through which nutritional risk was determined, and established the swallowing capacity of the study population. In our study, 53.3% of the population had moderate malnutrition according to the VGS Oncology, 33% weight loss record. The NRS 2002 show that 43.3% is at risk of malnutrition. The degree of dysphagia is shown more often in older patients, cancer type and stage of illness. Nutritional risk scales relate directly proportional to tumor location and stage, as well, there are other different oncological factors involved in the patient's nutritional deterioration. Therefore it is of vital importance to have a nutritionist as part of the multidisciplinary team, to detect the nutritional risk and to be able to handle it in an opportune way. Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

  18. Using the Devereux Early Childhood Assessment to Identify Behavioral Risk and Protective Factors within a Head Start Population

    ERIC Educational Resources Information Center

    Brinkman, Tara M.; Wigent, Catherine A.; Tomac, Rachelle A.; Pham, Andy V.; Carlson, John S.

    2007-01-01

    The purpose of this study was to examine the prevalence of behavioral risk and protective factors among at-risk preschoolers. Parent-reported data ( N = 2,550) from the Devereux Early Childhood Assessment (DECA) indicated that Head Start preschoolers had significantly more behavior concerns and fewer protective factors than would be expected based…

  19. Gender and line size factors modulate the deviations of the subjective visual vertical induced by head tilt

    PubMed Central

    2012-01-01

    Background The subjective visual vertical (SVV, the visual estimation of gravitational direction) is commonly considered as an indicator of the sense of orientation. The present study examined the impact of two methodological factors (the angle size of the stimulus and the participant's gender) on deviations of the SVV caused by head tilt. Forty healthy participants (20 men and 20 women) were asked to make visual vertical adjustments of a light bar with their head held vertically or roll-tilted by 30° to the left or to the right. Line angle sizes of 0.95° and 18.92° were presented. Results The SVV tended to move in the direction of head tilt in women but away from the direction of head tilt in men. Moreover, the head-tilt effect was also modulated by the stimulus' angle size. The large angle size led to deviations in the direction of head-tilt, whereas the small angle size had the opposite effect. Conclusions Our results showed that gender and line angle size have an impact on the evaluation of the SVV. These findings must be taken into account in the growing body of research that uses the SVV paradigm in disease settings. Moreover, this methodological issue may explain (at least in part) the discrepancies found in the literature on the head-tilt effect. PMID:22420467

  20. Factors predicting 'time to distant metastasis' in radically treated head and neck cancer.

    PubMed

    Krishnatry, R; Gupta, T; Murthy, V; Ghosh-Laskar, S; Budrukkar, A; Chaturvedi, P; Nair, S; Nair, D; Kumar, P; Joshi, A; Agarwal, J P

    2014-01-01

    Context: Various studies have shown the important risk factors for distant metastasis in head and neck cancer (HNC) which are present in most of the patients in developing countries. Identification of factors on the basis of time to distant metastasis (TDM) can help in future trials targeting smaller subgroups. Aims and Objectives: To identify the factors that predict TDM in radically treated HNC patients. Settings and Design: Retrospective audit. Materials and Methods: Retrospective audit of the prospectively maintained electronic database of a single HNC radiotherapy clinic from 1990 to 2010 was done to identify radically treated patients of HNC who developed distant metastasis. Univariate and multivariate analysis were done to identify baseline (demographic, clinical, pathological, and treatment) factors which could predict TDM, early time to metastasis (ETM; <12 months), intermediate time to metastasis (ITM; 12-24 months), and late time to metastasis (LTM; >2 years) using Kaplan Meier and Cox regression analysis, respectively. Results: One hundred patients with distant metastasis were identified with a median TDM of 7.4 months; 66 had ETM, 17 had ITM, and 17 had LTM. On multivariate analysis, the nodal stage 2-3 (N2/3) was the only baseline factor independently predicting TDM, ETM, and ITM, whereas none of the baseline factors predicted LTM. Conclusions: Higher nodal burden (N2/3) is associated with both ETM and ITM, and calls for aggressive screening, systemic therapy options, and surveillance. It is difficult to predict patients who are at a risk of developing LTM with baseline factors alone and evaluation of biological data is needed.

  1. Enhanced phonon scattering by nanovoids in high thermoelectric power factor polysilicon thin films

    NASA Astrophysics Data System (ADS)

    Dunham, Marc T.; Lorenzi, Bruno; Andrews, Sean C.; Sood, Aditya; Asheghi, Mehdi; Narducci, Dario; Goodson, Kenneth E.

    2016-12-01

    The ability to tune the thermal conductivity of semiconductor materials is of interest for thermoelectric applications, in particular, for doped silicon, which can be readily integrated in electronic microstructures and have a high thermoelectric power factor. Here, we examine the impact of nanovoids on the thermal conductivity of highly doped, high-power factor polysilicon thin films using time-domain thermoreflectance. Voids are formed through ion implantation and annealing, evolving from many small (˜4 nm mean diameter) voids after 500 °C anneal to fewer, larger (˜29 nm mean diameter) voids with a constant total volume fraction after staged thermal annealing to 1000 °C. The thermal conductivity is reduced to 65% of the non-implanted reference film conductivity after implantation and 500 °C anneal, increasing with anneal temperature until fully restored after 800 °C anneal. The void size distributions are determined experimentally using small-angle and wide-angle X-ray scattering. While we believe multiple physical mechanisms are at play, we are able to corroborate the positive correlation between measurements of thermal conductivity and void size with Monte Carlo calculations and a scattering probability based on Matthiessen's rule. The data suggest an opportunity for thermal conductivity suppression combined with the high power factor for increased material zT and efficiency of nanostructured polysilicon as a thermoelectric material.

  2. Four-jet production in single- and double-parton scattering within high-energy factorization

    NASA Astrophysics Data System (ADS)

    Kutak, Krzysztof; Maciula, Rafal; Serino, Mirko; Szczurek, Antoni; van Hameren, Andreas

    2016-04-01

    We perform a first study of 4-jet production in a complete high-energy factorization (HEF) framework. We include and discuss contributions from both single-parton scattering (SPS) and double-parton scattering (DPS). The calculations are performed for kinematical situations relevant for two experimental measurements (ATLAS and CMS) at the LHC. We compare our results to those reported by the ATLAS and CMS collaborations for different sets of kinematical cuts. The results of the HEF approach are compared with their counterparts for collinear factorization. For symmetric cuts the DPS HEF result is considerably smaller than the one obtained with collinear factorization. The mechanism leading to this difference is of kinematical nature. We conclude that an analysis of inclusive 4-jet production with asymmetric p T -cuts below 50 GeV would be useful to enhance the DPS contribution relative to the SPS contribution. In contrast to the collinear approach, the HEF approach nicely describes the distribution of the Δ S variable, which involves all four jets and their angular correlations.

  3. Parity-Violating Electron Deuteron Scattering and the Proton's Neutral Weak Axial Vector Form Factor

    SciTech Connect

    Ito, Takeyasu; Averett, Todd; Barkhuff, David; Batigne, Guillaume; Beck, Douglas; Beise, Elizabeth; Blake, A.; Breuer, Herbert; Carr, Robert; Clasie, Benjamin; Covrig, Silviu; Danagoulian, Areg; Dodson, George; Dow, Karen; Dutta, Dipangkar; Farkhondeh, Manouchehr; Filippone, Bradley; FRANKLIN, W.; Furget, Christophe; Gao, Haiyan; Gao, Juncai; Gustafsson, Kenneth; Hannelius, Lars; Hasty, R.; Allen, Alice; Herda, M.C.; Jones, CE; King, Paul; Korsch, Wolfgang; Kowalski, Stanley; Kox, Serge; Kramer, Kevin; Lee, P.; Liu, Jinghua; Martin, Jeffery; McKeown, Robert; Mueller, B.; Pitt, Mark; Plaster, Bradley; Quemener, Gilles; Real, Jean-Sebastien; Ritter, J.; Roche, Julie; Savu, V.; Schiavilla, Rocco; Seely, Charles; Spayde, Damon; Suleiman, Riad; Taylor, S.; Tieulent, Raphael; Tipton, Bryan; Tsentalovich, E.; Wells, Steven; Yang, Bin; Yuan, Jing; Yun, Junho; Zwart, Townsend

    2004-03-01

    We report on a new measurement of the parity-violating asymmetry in quasielastic electron scattering from the deuteron at backward angles at Q2 = 0.038 (GeV/c)2. This quantity provides a determination of the neutral weak axial vector form factor of the nucleon, which can potentially receive large electroweak corrections. The measured asymmetry A = z3.51±0.57 (stat)±0.58 (syst) ppm is consistent with theoretical predictions. We also report on updated results of the previous experiment at Q2 = 0.091 (GeV/c)2, which are also consistent with theoretical predictions.

  4. Extracting scattering coefficient and anisotropy factor of tissue using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Choudhury, Niloy; Jacques, Steven L.

    2012-03-01

    Determination of tissue optical properties is important as it will lead to better design of optical diagnostic tools, improvement in laser therapy, photo dynamic therapy dosimetry, drug pharmacokinetics, etc. We have developed a theoretical model for OCT signal using Monte Carlo simulation that allows us to fit values extracted from the OCT signal, namely, reflectance, ρ, and the total optical attenuation coefficient, μt, to obtain optical properties of tissue (scattering coefficient, μs, and anisotropy factor, g). Using this method we have extracted optical properties of different tissue types, e.g., skin, muscle, liver, and brain of mouse.

  5. Head-up displays and their automotive application: an overview of human factors issues affecting safety.

    PubMed

    Ward, N J; Parkes, A

    1994-12-01

    In response to the recent innovations to use head-up displays (HUDs) in vehicles, this paper discusses the relevant human factors issues arising from this display format and the potential safety implications. A review is made of the relevant HUD literature, primarily from the aviation field. The primary issues for automotive HUDs relevant to system performance and safety in the driving task involve interference from background scene complexity, system novelty, user perceptual style, cognitive disruption, and perceptual tunnelling. Basic research is necessary to investigate the extent of these issues as well as to resolve fundamental design specifications (e.g. HUD size, shape, placement, information content). It is suggested that the introduction of HUDs into vehicles be carefully considered. This will necessitate not only the reconsideration what constitutes an in-vehicle display, but also what constitutes the information to be conveyed.

  6. Derivation of factors for estimating the scatter of diagnostic x-rays from walls and ceiling slabs.

    PubMed

    Martin, C J; Sutton, D G; Magee, J; McVey, S; Williams, J R; Peet, D

    2012-12-01

    Computed tomography (CT) scanning rooms and interventional x-ray facilities with heavy workloads may require the installation of shielding to protect against radiation scattered from walls or ceiling slabs. This is particularly important for the protection of those operating x-ray equipment from within control cubicles who may be exposed to radiation scattered from the ceiling over the top of the protective barrier and round the side if a cubicle door is not included. Data available on the magnitude of this tertiary scatter from concrete slabs are limited. Moreover, there is no way in which tertiary scatter levels can be estimated easily for specific facilities. There is a need for a suitable method for quantification of tertiary scatter because of the increases in workloads of complex x-ray facilities. In this study diagnostic x-ray air kerma levels scattered from concrete and brick walls have been measured to verify scatter factors. The results have been used in a simulation of tertiary scatter for x-ray facilities involving summation of scatter contributions from elements across concrete ceiling slabs. The majority of the ceiling scatter air kerma to which staff behind a barrier will be exposed arises from the area between the patient/x-ray tube and the staff. The level depends primarily on the heights of the ceiling and protective barrier. A method has been developed to allow tertiary scatter levels to be calculated using a simple equation based on a standard arrangement for rooms with different ceiling and barrier heights. Coefficients have been derived for a CT facility and an interventional suite to predict tertiary scatter levels from the workload, so that consideration can be given to the protection options available.

  7. Factors Influencing the Incidence of Severe Complications in Head and Neck Free Flap Reconstructions

    PubMed Central

    Broome, Martin; Juilland, Naline; Litzistorf, Yann; Monnier, Yan; Sandu, Kishore; Pasche, Philippe; Plinkert, Peter K.; Federspil, Philippe A.

    2016-01-01

    Background: Complications after head and neck free-flap reconstructions are detrimental and prolong hospital stay. In an effort to identify related variables in a tertiary regional head and neck unit, the microvascular reconstruction activity over the last 5 years was captured in a database along with patient-, provider-, and volume-outcome–related parameters. Methods: Retrospective cohort study (level of evidence 3), a modified Clavien-Dindo classification, was used to assess severe complications. Results: A database of 217 patients was created with consecutively reconstructed patients from 2009 to 2014. In the univariate analysis of severe complications, we found significant associations (P < 0.05) between type of flap used, American Society of Anesthesiologists classification, T-stage, microscope use, surgeon, flap frequency, and surgeon volume. Within a binomial logistic regression model, less frequently versus frequently performed flap (odds ratio [OR] = 3.2; confidence interval [CI] = 2.9–3.5; P = 0.000), high-volume versus low-volume surgeon (OR = 0.52; CI = −0.22 to 0.82; P = 0.007), and ASA classification (OR = 2.9; CI = 2.4–3.4; P = 0.033) were retained as independent predictors of severe complications. In a Cox-regression model, surgeon (P = 0.011), site of reconstruction (P = 0.000), T-stage (P = 0.001), and presence of severe complications (P = 0.015) correlated with a prolonged hospitalization. Conclusions: In this study, we identified a correlation of patient-related factors with severe complications (ASA score) and prolonged hospital stay (T-stage, site). More importantly, we identified several provider- (surgeon) and volume-related (frequency with which a flap was performed and high-volume surgeon) factors as predictors of severe complications. Our data indicate that provider- and volume-related parameters play an important role in the outcome of microvascular free-flap procedures in the head and neck region. PMID:27826458

  8. SU-F-BRD-12: When Does Pencil Beam Scanning Become Superior to Passive Scattered Proton Therapy for Pediatric Head and Neck Cancers?

    SciTech Connect

    Moteabbed, M; Depauw, N; Kooy, H; Yock, T; Paganetti, H

    2015-06-15

    Purpose: To investigate the dosimetric benefits of pencil beam scanning (PBS) compared with passive scattered (PS) proton therapy for treatment of pediatric head&neck patients as a function of the PBS spot size and explore the advantages of using apertures in PBS. Methods: Ten pediatric patients with head&neck cancers treated by PS proton therapy at our institution were retrospectively selected. The histologies included rhabdomyosarcoma, ependymoma, astrocytoma, craniopharyngioma and germinoma. The prescribed dose ranged from 36 to 54 Gy(RBE). Five PBS plans were created for each patient using variable spot size (average sigma at isocenter) and choice of beam specific apertures: (1) 10mm spots, (2) 10mm spots with apertures, (3) 6mm spots, (4) 6mm spots with apertures, and (5) 3mm spots. The plans were optimized for intensity modulated proton therapy (IMPT) with no single beam uniformity constraints. Dose volume indices as well as equivalent uniform dose (EUD) were compared between PS and PBS plans. Results: Although target coverage was clinically adequate for all cases, the plans with largest (10mm) spots provide inferior quality compared with PS in terms of dose to organs-at-risk (OAR). However, adding apertures to these plans ensured lower OAR dose than PS. The average EUD difference between PBS and PS plans over all patients and organs at risk were (1) 2.5%, (2) −5.1%, (3) -5%, (4) −7.8%, and (5) −9.5%. As the spot size decreased, more conformal plans were achieved that offered similar target coverage but lower dose to the neighboring healthy organs, while alleviating the need for using apertures. Conclusion: The application of PBS does not always translate to better plan qualities compared to PS depending on the available beam spot size. We recommend that institutions with spot size larger than ∼6mm at isocenter consider using apertures to guarantee clinically comparable or superior dosimetric efficacy to PS treatments.

  9. X-ray Intermolecular Structure Factor (XISF): separation of intra- and intermolecular interactions from total X-ray scattering data

    SciTech Connect

    Mou, Q.; Benmore, C. J.; Yarger, J. L.

    2015-06-01

    XISF is a MATLAB program developed to separate intermolecular structure factors from total X-ray scattering structure factors for molecular liquids and amorphous solids. The program is built on a trust-region-reflective optimization routine with the r.m.s. deviations of atoms physically constrained. XISF has been optimized for performance and can separate intermolecular structure factors of complex molecules.

  10. Parental anxiety and affecting factors in acute paediatric blunt head injury.

    PubMed

    Serinken, M; Kocyigit, A; Karcioglu, O; Sengül, C; Hatipoğlu, C; Elicabuk, H

    2014-08-01

    This study is designed to investigate the factors affecting parental anxiety regarding their children with head injury in the emergency department (ED). This prospective observational study enrolled all consecutive paediatric patients admitted to the university-based ED with the presenting chief complaint of paediatric blunt head injury (PBHI). The parents were asked to respond to the 10-item questionnaire during both presentation and discharge. Anxiety and persuasion scores of the parents were calculated and magnitudes of the decreases in anxiety and persuasion scores were analysed with respect to sociodemographic and clinical variables. The study sample included 341 patients admitted to the ED. The anxiety and persuasion scores of mothers and fathers were not significantly different from each other on presentation while the extent of decrease in anxiety scores of mothers were significantly smaller than that of the fathers (p=0.003). The parents' education levels had significant impact on anxiety and persuasion scores recorded on presentation. The anxiety and persuasion scores were inversely related to education levels of the parents on presentation (p=0.002 and p=0.000, respectively). In addition, lower education levels were found to be associated with a greater decrease in anxiety and persuasion scores. Neurosurgical consultation also affected the magnitude of the decrease in anxiety and persuasion scores of the parents. The changes in the scores were affected negatively by the parents' age. Radiological investigations had no significant impact on the decrease in anxiety and persuasion scores of the parents by themselves, while neurosurgical consultation had significant impact on them. Emergency physicians should tailor their strategy to institute effective communication with the parents of children to cut down unnecessary investigations in PBHI. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence

  11. [Factors Contributing to Surgical Intervention for Subacute Subdural Hematoma Enlargement in Patients with Mild Head Injuries].

    PubMed

    Akamatsu, Yosuke; Sasaki, Tohru; Kanamori, Masayuki; Suzuki, Shinsuke; Uenohara, Hiroshi; Tominaga, Teiji

    2017-09-01

    Delayed neurological deterioration following mild head injury(MHI)usually occurs within 24 hours. However, some cases require delayed surgical evacuation of an acute subdural hematoma(ASDH), owing to subacute progressive hematoma enlargement. This study aimed to determine radiological or clinical parameters associated with surgical intervention in ASDH cases in which surgery was not initially considered necessary. From 2010 to 2015, 64 patients were non-surgically treated for ASDH following MHI. We evaluated the various outcomes of eventual surgical ASDH evacuation after the first 48 hours following injury, due to hematoma enlargement and clinical deterioration. Univariate and multivariate analyses were applied to both the demographic and initial radiographic features to identify risk factors for ASDH progression and surgery. Overall, at the time of their last follow-up computed tomography, 57 patients(89%)demonstrated minimal ASDH or spontaneous hematoma resolution with conservative non-surgical management. The remaining 7 patients(11%)received delayed surgical ASDH evacuation a median of 5.1 days after the head trauma. There were no significant differences between the two groups for baseline characteristics, including age, prior history of anticoagulants, the presence of cerebral contusions, or subarachnoid hemorrhages. On multivariate analysis, use of antiplatelet drugs(p=0.013, OR=28, 95%CI=1.82-24)was independently associated with delayed hematoma evacuation. These data indicate that as much as 11% of patients with minimal ASDHs after MHI can deteriorate over the course of a week and then require surgical intervention, and that patients on concurrent antiplatelet medication require especially careful monitoring of hematoma progression.

  12. Predictive factors for surgical site infection in head and neck cancer surgery: A case-control study.

    PubMed

    Henry, J S; Buffet-Bataillon, S; Deberge, S; Jegoux, F

    2014-01-01

    Surgical Site Infection (SSI) after head and neck cancer surgery may be life threatening and induces increasing in healthcare cost. The objective of this present study was to identify predictive factors associated to surgical site infection in head and neck cancer surgery. Numerous predictive factors were analyzed with univariate case-control method, then with multivariate method. This retrospective study included 71 patients who have been hospitalized in our department during 2010 for a head and neck cancer surgery. The incidence of surgical site infection was 15.5%. The T3-T4 stages were identified as an independent predictive factor (p = 0.04). Our study does not find other predictive factor for a SSI. The NNIS index (National Nosocomial Infections Surveillance), used by the Center for disease control and prevention as predictive factor, was not valid in our study. A specific predictive index should include the tumor stage for Head and Neck Cancer surgery and should be taken into account for the management of a preventive antibiotic treatment.

  13. Stepwise Progress in Epidermal Growth Factor Receptor/Radiation Studies for Head and Neck Cancer

    SciTech Connect

    Harari, Paul M.

    2007-10-01

    The U.S. Food and Drug Administration approval of four new epidermal growth factor receptor (EGFR) inhibitors for cancer therapy (cetuximab, panitumumab, gefitinib, and erlotinib) over the last 3 years is a remarkable milestone in oncology. Indeed, molecular inhibition of EGFR signaling represents one of the most promising current arenas for the development of molecular-targeted cancer therapies. Epidermal growth factor receptor inhibitors from both the monoclonal antibody and tyrosine kinase inhibitor class have demonstrated clinical activity in the treatment of a broad spectrum of common human malignancies. For the discipline of radiation oncology, the 2006 report of a phase III trial demonstrating a survival advantage for advanced head and neck cancer patients with the addition of weekly cetuximab during a 7-week course of radiation is particularly gratifying. Indeed, this is the first phase III trial to confirm a survival advantage with the addition of a molecular-targeted agent to radiation. Furthermore, this result seems to have been achieved with only a modest increment in overall treatment toxicity and with very high compliance to the prescribed treatment regimen. Nevertheless, much remains to be learned regarding the rational integration of EGFR inhibitors into cancer treatment regimens, as well as methods to optimize the selection of patients most likely to benefit from EGFR inhibitor strategies.

  14. Nuclear epidermal growth factor receptor and p16 expression in head and neck squamous cell carcinoma.

    PubMed

    Husain, Hatim; Psyrri, Amanda; Markovic, Ana; Rampias, Theodore; Pectasides, Eirini; Wang, Hao; Slebos, Robbert; Yarbrough, Wendell G; Burtness, Barbara; Chung, Christine H

    2012-12-01

    Epidermal growth factor receptor (EGFR) and p16 (a surrogate marker of human papillomavirus [HPV] infection) expression are strong prognostic factors in patients with head and neck squamous cell carcinoma (HNSCC). We examined expression levels of total and nuclear EGFR as well as p16 status based on evidence that nuclear EGFR may have a role in DNA damage repair. An HPV-negative (SQ20B) and an HPV-positive (UMSCC47) HNSCC cell line were examined for EGFR and γH2AX expression. A tissue microarray containing 123 cores obtained from 101 HNSCC tumors was analyzed for EGFR expression by automated quantitative analysis and p16 expression by immunohistochemical staining, and these results were correlated with available clinical data. SQ20B had higher EGFR expression than UMSCC47. Nuclear localization of EGFR on activation with transforming growth factor-α was observed in SQ20B, but not in UMSCC47. SQ20B also had increased γH2AX foci compared to UMSCC47, suggesting that SQ20B has more DNA damage compared to UMSCC47. Total and nuclear EGFR was reliably obtained from 80 of 101 patients. p16 levels were determined in 87 of 101 patients. p16 levels were strongly associated with the oropharyngeal subsite and poorly differentiated histology. Expression of total and nuclear EGFR was higher in p16-negative tumors compared to p16-positive tumors (Wilcoxon rank test, P = .038 and P = .014, respectively). Further studies are required to determine a mechanistic link between these two prognostic factors and the significance of EGFR localization to nucleus in DNA damage repair pathway activation. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

  15. Socioeconomic factors and survival in patients with non-metastatic head and neck squamous cell carcinoma.

    PubMed

    Xu, Cheng; Chen, Yu-Pei; Liu, Xu; Tang, Ling-Long; Chen, Lei; Mao, Yan-Ping; Zhang, Yuan; Guo, Rui; Zhou, Guan-Qun; Li, Wen-Fei; Lin, Ai-Hua; Sun, Ying; Ma, Jun

    2017-04-06

    The effect of socioeconomic factors on receipt of definitive treatment and survival outcomes in non-metastatic head and neck squamous cell carcinoma (HNSCC) remains unclear. Eligible patients (n = 37,995) were identified from the United States Surveillance, Epidemiology and End Results (SEER) database between 2007 and 2012. Socioeconomic factors (i.e., median household income, education level, unemployment rate, insurance status, marital status and residence) were included in univariate/multivariate Cox regression analysis; validated factors were used to generate nomograms for cause-specific survival (CSS) and overall survival (OS), and a prognostic score model for risk stratification. Low- and high-risk groups were compared for all cancer subsites. Impact of race/ethnicity on survival was investigated in each risk group. Marital status, median household income and insurance status were included in the nomograms for CSS and OS, which had higher c-indexes than the 6th edition TNM staging system (all P-values < 0.001). Based on three disadvantageous socioeconomic factors (i.e., unmarried status, uninsured status, median household income < US $65,394), the prognostic score model generated four risk subgroups with scores of 0, 1, 2 or 3, which had significantly separated CSS/OS curves (all P-values < 0.001). Low-risk patients (score 0-1) were more likely to receive definitive treatment and obtain better CSS/OS than high-risk patients (score 2-3). Chinese and non-Hispanic black patients with high-risk socioeconomic status had best and poorest CSS/OS, respectively. Therefore, marital status, median household income and insurance status have significance for predicting survival outcomes. Low-risk socioeconomic status and Chinese race/ethnicity confer protective effects in HNSCC. This article is protected by copyright. All rights reserved.

  16. [Measuring the calibration factor of a light scattering dust monitor for CO2 arc welding fumes].

    PubMed

    Ojima, Jun

    2002-12-01

    In Japan, a light scattering type digital dust monitor is most commonly used for dust concentration measurement in a working environment. In this study, the calibration factors of a digital dust monitor (K-factor) for several welding fumes were measured in a laboratory. During the experiment, fumes were generated from CO2 arc welding performed by an automatic welding robot. The examined welding wires were JIS Z 3312, Z 3313, Z 3315, Z 3317 and Z 3320. The mass and relative concentrations of the welding fumes were measured simultaneously by a total/respirable (TR) dust sampler and a digital dust monitor at a welding current of 100 A, 150 A, 200 A, 250 A and 300 A. The particle size distributions of welding fumes were measured by a low pressure impactor at a welding current of 100 A and 300 A. A significant effect of the welding current on the K-factor was recognized for all the examined wires. In the most remarkable case, a four-fold difference in the K-factors was found when the fumes were generated from a flux cored wire for mild steel (JIS Z 3313). The particle size distributions of fumes were also affected by the welding current. The coefficients of variation in the measured K-factor were 7.8-40.5%.

  17. The potential lymphangiogenic effects of hepatocyte growth factor/scatter factor in vitro and in vivo.

    PubMed

    Jiang, Wen G; Davies, Gaynor; Martin, Tracey A; Parr, Christian; Watkins, Gareth; Mansel, Robert E; Mason, Malcolm D

    2005-10-01

    Lymphangiogenesis is key to the lymphatic spread of cancer cells. The current study examined the potential effect of hepatocyte growth factor (HGF), a factor known to have strong biological effects on endothelial cells, on the lymphangiogenic function of endothelial cells and the formation of lymphatic vessels using both in vitro and in vivo models. Human endothelial cells that have lymphatic characteristics, human prostate and breast cancer cells PC-3 and MDA MB 231, were used. Expression of lymphatic markers, podoplanin, Prox-1, vascular endothelial growth factor receptor 3 (VEGF-R3) and LYVE-1 was determined using reverse transcription polymerase reaction and quantitative PCR. In nude mice prostate and breast xenograft tumour models, either HGF or an HGF-producing fibroblast cell line MRC-5 was given with or without the HGF antagonist, NK4. The lymphangiogenic marker and lymphatic vessels in tumour tissues were also assessed using quantitative PCR and immunohistochemistry, respectively. In the mice tumour models, infusion of rhHGF significantly increased the levels of podoplanin and LYVE-1 in the tumour (p=0.05 for podoplanin and p<0.05 for LYVE-1 vs. without HGF in the prostate tumour model, p<0.05 for podoplanin and p<0.01 for LYVE-1 vs. without HGF for the breast tumour model; p<0.05 for podoplanin and p<0.01 for LYVE-1 vs. without HGF in the breast tumour model). The increased level of LYVE-1 transcript was supported by an increase in the number of LYVE-1-positive lymphatic vessels in tumours, using immunohistochemical analysis. Co-injection of MRC5 cells also increased the levels of LYVE-1 and number of LYVE-1-positive vessels in tumour tissues. The effects of HGF and MRC5 were significantly reduced by the HGF antagonist, NK4. In the in vitro models, rhHGF significantly increased the level of both podoplanin and LYVE-1, as shown by quantitative PCR analysis. Hepatocyte growth factor has potential lymphangiogenic activities, and this may have important

  18. Head injury as a risk factor for Alzheimer's disease: the evidence 10 years on; a partial replication

    PubMed Central

    Fleminger, S; Oliver, D; Lovestone, S; Rabe-Hesketh, S; Giora, A

    2003-01-01

    Objective: To determine, using a systematic review of case-control studies, whether head injury is a significant risk factor for Alzheimer's disease. We sought to replicate the findings of the meta-analysis of Mortimer et al (1991). Methods: A predefined inclusion criterion specified case-control studies eligible for inclusion. A comprehensive and systematic search of various electronic databases, up to August 2001, was undertaken. Two independent reviewers screened studies for eligibility. Fifteen case-control studies were identified that met the inclusion criteria, of which seven postdated the study of Mortimer et al. Results: We partially replicated the results of Mortimer et al. The meta-analysis of the seven studies conducted since 1991 did not reach significance. However, analysis of all 15 case-control studies was significant (OR 1.58, 95% CI 1.21 to 2.06), indicating an excess history of head injury in those with Alzheimer's disease. The finding of Mortimer et al that head injury is a risk factor for Alzheimer's disease only in males was replicated. The excess risk of head injury in those with Alzheimer's disease is only found in males (males: OR 2.29, 95% CI 1.47 to 2.06; females: OR 0.91, 95% CI 0.56 to 1.47). Conclusions: This study provides support for an association between a history of previous head injury and the risk of developing Alzheimer's disease. PMID:12810767

  19. Architectural constraints are a major factor reducing path integration accuracy in the rat head direction cell system.

    PubMed

    Page, Hector J I; Walters, Daniel; Stringer, Simon M

    2015-01-01

    Head direction cells fire to signal the direction in which an animal's head is pointing. They are able to track head direction using only internally-derived information (path integration)In this simulation study we investigate the factors that affect path integration accuracy. Specifically, two major limiting factors are identified: rise time, the time after stimulation it takes for a neuron to start firing, and the presence of symmetric non-offset within-layer recurrent collateral connectivity. On the basis of the latter, the important prediction is made that head direction cell regions directly involved in path integration will not contain this type of connectivity; giving a theoretical explanation for architectural observations. Increased neuronal rise time is found to slow path integration, and the slowing effect for a given rise time is found to be more severe in the context of short conduction delays. Further work is suggested on the basis of our findings, which represent a valuable contribution to understanding of the head direction cell system.

  20. Architectural constraints are a major factor reducing path integration accuracy in the rat head direction cell system

    PubMed Central

    Page, Hector J. I.; Walters, Daniel; Stringer, Simon M.

    2015-01-01

    Head direction cells fire to signal the direction in which an animal's head is pointing. They are able to track head direction using only internally-derived information (path integration)In this simulation study we investigate the factors that affect path integration accuracy. Specifically, two major limiting factors are identified: rise time, the time after stimulation it takes for a neuron to start firing, and the presence of symmetric non-offset within-layer recurrent collateral connectivity. On the basis of the latter, the important prediction is made that head direction cell regions directly involved in path integration will not contain this type of connectivity; giving a theoretical explanation for architectural observations. Increased neuronal rise time is found to slow path integration, and the slowing effect for a given rise time is found to be more severe in the context of short conduction delays. Further work is suggested on the basis of our findings, which represent a valuable contribution to understanding of the head direction cell system. PMID:25705190

  1. Hepatocyte growth factor/scatter factor enhances the invasion of mesothelioma cell lines and the expression of matrix metalloproteinases

    PubMed Central

    Harvey, P; Clark, I M; Jaurand, M-C; Warn, R M; Edwards, D R

    2000-01-01

    Hepatocyte growth factor/scatter factor (HGF/SF) is a multifunctional factor involved both in development and tissue repair, as well as pathological processes such as cancer and metastasis. It has been identified in vivo in many types of tumours together with its tyrosine kinase receptor, Met. We show here that exogenous HGF/SF acts as a strong chemoattractant for human mesothelioma cell lines. The factor also enhanced cell adhesion to and invasion into Matrigel. The mesothelioma cell lines synthesized a panel of matrix metalloproteinases critical for tumour progression such as MMP-1, 2, 3, 9 and membrane-bound MT1-MMP. HGF/SF stimulated the expression of MMP-1, 9 and MT1-MMP and had a slight effect on expression of the MMP inhibitor TIMP-1 but not TIMP-2. However, there was no simple correlation between the levels of MMPs and TIMPs of the cell lines and their different invasion properties or between HGF/SF stimulatory effects on MMP expression and invasion. In addition, effects of protease inhibitors on invasion suggested that serine proteases were also expressed in human mesothelioma cell lines and were involved in HGF/SF-induced invasion. The results show a predominant role for HGF/SF in mesothelioma cell invasion, stimulating simultaneously adhesion, motility, invasion and regulation of MMP and TIMP levels. © 2000 Cancer Research Campaign PMID:11027427

  2. Examining Risk and Protective Factors in Head Start Populations Located in High- and Low-Violence Communities

    ERIC Educational Resources Information Center

    Fedor, Megan C.; Bender, Stacy L.; Carlson, John S.

    2010-01-01

    This study examined parental reports of children attending Head Start programs in high- (N = 200) and low- (N = 188) violence communities to determine whether differences existed in the level of risk and protective factors as measured by the Devereux Early Childhood Assessment (P. A. LeBuffe & J. A. Naglieri, 1999). Previous research has indicated…

  3. HGF/scatter factor selectively promotes cell invasion by increasing integrin avidity.

    PubMed

    Trusolino, L; Cavassa, S; Angelini, P; Andó, M; Bertotti, A; Comoglio, P M; Boccaccio, C

    2000-08-01

    Hepatocyte growth factor/scatter factor (HGF/SF) controls a genetic program known as 'invasive growth', which involves as critical steps cell adhesion, migration, and trespassing of basement membranes. We show here that in MDA-MB-231 carcinoma cells, these steps are elicited by HGF/SF but not by epidermal growth factor (EGF). Neither factor substantially alters the production or activity of extracellular matrix proteases. HGF/SF, but not EGF, selectively promotes cell adhesion on laminins 1 and 5, fibronectin, and vitronectin through a PI3-K-dependent mechanism. Increased adhesion is followed by enhanced invasiveness through isolated matrix proteins as well as through reconstituted basement membranes. Inhibition assays using function-blocking antibodies show that this phenomenon is mediated by multiple integrins including beta1, beta3, beta4, and beta5. HGF/SF triggers clustering of all these integrins at actin-rich adhesive sites and lamellipodia but does not quantitatively modify their membrane expression. These data suggest that HGF/SF promotes cell adhesion and invasiveness by increasing the avidity of integrins for their specific ligands.

  4. Factors affecting breeding season survival of red-headed woodpeckers in South Carolina

    Treesearch

    John C. Kilgo; Mark Vukovich

    2012-01-01

    Red-headed woodpecker (Melanerpes erythrocephalus) populations have declined in the United States and Canada over the past 40 years. However, few demographic studies have been published on the species and none have addressed adult survival. During 2006¨C2007, we estimated survival probabilities of 80 radio-tagged red-headed woodpeckers during the breeding season in...

  5. Family Factors Associated with High Academic Competence among Former Head Start Children.

    ERIC Educational Resources Information Center

    Robinson, Nancy M.; Weinberg, Richard A.; Redden, David; Ramey, Sharon L.; Ramey, Craig T.

    1998-01-01

    A study of 154 Head Start children with high academic achievement found that their families reported higher educational and income levels, had fewer children, were more likely to be Caucasian, reported less prolonged depression, and had more responsive, flexible, and less restrictive parenting practices than other Head Start children. (Author/CR)

  6. Outcomes and factors associated with infant abusive head trauma in the US.

    PubMed

    Nuño, Miriam; Pelissier, Lindsey; Varshneya, Kunal; Adamo, Matthew A; Drazin, Doniel

    2015-07-31

    OBJECT Head trauma is the leading cause of death in abused children, particularly prior to the age of 2 years. An awareness of factors associated with this condition as well as with a higher risk of mortality is important to improve outcomes and prevent the occurrence of these events. The objective of this study was to evaluate outcomes and factors associated with poor outcomes in infants with diagnosed abusive head trauma (AHT). Patient characteristics, socioeconomic factors, and secondary conditions such as retinal bleeding, contusion, and fractures were considered. METHODS Data were obtained from the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality. From the Kids' Inpatient Database (KID) sample, the authors identified infants no older than 23 months who had been diagnosed with AHT in 2000, 2003, 2006, and 2009. All statistical analyses were conducted in SAS 9.2. Descriptive statistics were provided, and multivariate logistic regression models were applied to evaluate factors associated with mortality and nonroutine discharge. RESULTS A total of 5195 infants were analyzed in this study. Most infants (85.5%) had ages ranging between 0 and 11 months and were male (61.6%). Overall mortality was 10.8%, with a rate of 9.8% in the 0- to 11-month-old cohort and 16.5% in the 12- to 23-month-olds (p = 0.0003). The overall nonroutine discharge rate of 25.6% increased significantly from 23.3% to 39.0% with increasing age (0-11 vs 12-23 months of age, p < 0.0001). Assuming a multivariate model that adjusted for multiple confounders, the authors found that older infants (12-23 vs 0-11 months, OR 1.81, 95% CI 1.18-2.77) with a secondary diagnosis of retinal bleeding (OR 2.85, 95% CI 2.02-4.00) or shaken baby syndrome (OR 2.09, 95% CI 1.48-2.94) had an increased risk of mortality; these factors were similarly associated with an increased odds of a nonroutine discharge. A higher income ($30,001-$35,000 vs $1-$24,999) was associated with

  7. Factorizations in special relativity and quantum scattering on the line II

    NASA Astrophysics Data System (ADS)

    Brezov, Danail S.; Mladenova, Clementina D.; Mladenov, Ivaïlo M.

    2016-12-01

    The present paper may be regarded as a continuation of both [1] and [2]: we discuss the same physical context as in the former, while applying a specific decomposition technique initially proposed in the latter. The method used in [1], however, is completely different (based on repetitive conjugation) and has more in common with the familiar Wigner decomposition [3]. Here we obtain in a dynamical manner a compact two-factor decomposition, which in the Euclidean case allows for convenient parametrizations in rigid body kinematics and quantum-mechanical angular momenta. Applied to the group Spin(2, 1) ≅ SL(2, ℝ), this technique yields numerous applications in hyperbolic geometry and 2 + 1 dimensional special relativity. However, we choose to illustrate it with a particular problem arising in quantum mechanical scattering theory. The extension to SO(3, 1) and SO(2, 2) is discussed as well and numerical examples are provided in the former case.

  8. Bilateral choroidal neovascularization associated with optic nerve head drusen treated by antivascular endothelial growth factor therapy

    PubMed Central

    Delas, Barbara; Almudí, Lorena; Carreras, Anabel; Asaad, Mouafk

    2012-01-01

    Objective To report a good clinical outcome in a patient with bilateral choroidal neovascularization (CNV) associated with optic nerve head drusen (ONHD) treated with intravitreal ranibizumab injection. Methods A 12-year-old girl was referred for loss of right eye vision detected in a routine check-up. Best-corrected visual acuity (BCVA) was hand movements in the right eye and 0.9 in the left eye. Funduscopy revealed the presence of superficial and buried bilateral ONHD, which was confirmed by ultrasonography and computed tomography, and the study was completed with perimetry. The presence of bilateral CNV, active in the right eye, was observed and subsequently confirmed using fluorescein angiography and optical coherence tomography. Results Treatment with two consecutive injections of intravitreal ranibizumab resulted in inactivation of the neovascular membrane with subretinal fluid reabsorption and improved right eye BCVA. After 12 months’ follow-up, this was 20/60 and stable. Conclusion Although there are no published studies of safety in children, antiangiogenic therapy for CNV secondary to ONHD may be useful and safe. A search of the literature produced only one previously reported case of ONHD-associated CNV treated with antivascular endothelial growth factor alone. PMID:22368440

  9. Overexpression and activation of hepatocyte growth factor/scatter factor in human non-small-cell lung carcinomas.

    PubMed Central

    Olivero, M.; Rizzo, M.; Madeddu, R.; Casadio, C.; Pennacchietti, S.; Nicotra, M. R.; Prat, M.; Maggi, G.; Arena, N.; Natali, P. G.; Comoglio, P. M.; Di Renzo, M. F.

    1996-01-01

    Hepatocyte growth factor/scatter factor (HGF/SF) stimulates the invasive growth of epithelial cells via the c-MET oncogene-encoded receptor. In normal lung, both the receptor and the ligand are detected, and the latter is known to be a mitogenic and a motogenic factor for both cultured bronchial epithelial cells and non-small-cell carcinoma lines. Here, ligand and receptor expression was examined in 42 samples of primary human non-small-cell lung carcinoma of different histotype. Each carcinoma sample was compared with adjacent normal lung tissue. The Met/HGF receptor was found to be 2 to 10-fold increased in 25% of carcinoma samples (P = 0.0113). The ligand, HGF/SF, was found to be 10 to 100-fold overexpressed in carcinoma samples (P < 0.0001). Notably, while HGF/SF was occasionally detectable and found exclusively as a single-chain inactive precursor in normal tissues, it was constantly in the biologically-active heterodimeric form in carcinomas. Immunohistochemical staining showed homogeneous expression of both the receptor and the ligand in carcinoma samples, whereas staining was barely detectable in their normal counterparts. These data show that HGF/SF is overexpressed and consistently activated in non-small-cell lung carcinomas and may contribute to the invasive growth of lung cancer. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:8980383

  10. Evaluation of time-resolved multi-distance methods to retrieve absorption and reduced scattering coefficients of adult heads in vivo: Optical parameters dependences on geometrical structures of the models used to calculate reflectance

    NASA Astrophysics Data System (ADS)

    Tanifuji, T.

    2016-03-01

    Time-resolved multi-distance measurements are studied to retrieve absorption and reduced scattering coefficients of adult heads, which have enough depth sensitivity to determine the optical parameters in superficial tissues and brain separately. Measurements were performed by putting the injection and collection fibers on the left semi-sphere of the forehead, with the injection fiber placed toward the temporal region, and by moving the collection fiber between 10 and 60 mm from the central sulcus. It became clear that optical parameters of the forehead at all collection fibers were reasonably determined by selecting the appropriate visibility length of the geometrical head models, which is related to head surface curvature at each position.

  11. Is MDM2 SNP309 Variation a Risk Factor for Head and Neck Carcinoma?

    PubMed Central

    Zhuo, Xianlu; Ye, Huiping; Li, Qi; Xiang, Zhaolan; Zhang, Xueyuan

    2016-01-01

    Abstract Murine double minute-2 (MDM2) is a negative regulator of P53, and its T309G polymorphism has been suggested as a risk factor for a variety of cancers. Increasing evidence has shown the association of MDM2 T309G polymorphism with head and neck carcinoma (HNC) risk. However, the results are inconsistent. Thus, we performed a meta-analysis to elucidate the association. The meta-analysis retrieved studies published up to August 2015, and essential information was extracted for analysis. Separate analyses on ethnicity, source of controls, sample size, detection method, and cancer types were also conducted. Odds ratios (ORs) and their 95% confidence intervals (CIs) were used to estimate the association. Pooled data from 16 case–control studies including 4625 cases and 6927 controls failed to indicate a significant association. However, in the subgroup analysis of sample sizes, an increased risk was observed in the largest sample size group (>1000) under a recessive model (OR = 1.52; 95% CI = 1.08–2.13). Increased risks were also found in the nasopharyngeal cancer in the subgroup analysis of cancer types (GG vs TT: OR = 2.07; 95% CI = 1.38–3.12; dominant model: OR = 1.48; 95% CI = 1.13–1.93; recessive model: OR = 1.76; 95% CI = 1.17–2.65). The results suggest that homozygote GG alleles of MDM2 SNP309 may be a low-penetrant risk factor for HNC, and G allele may confer nasopharyngeal cancer susceptibility. PMID:26945408

  12. Investigation of electron-loss and photon scattering correction factors for FAC-IR-300 ionization chamber

    NASA Astrophysics Data System (ADS)

    Mohammadi, S. M.; Tavakoli-Anbaran, H.; Zeinali, H. Z.

    2017-02-01

    The parallel-plate free-air ionization chamber termed FAC-IR-300 was designed at the Atomic Energy Organization of Iran, AEOI. This chamber is used for low and medium X-ray dosimetry on the primary standard level. In order to evaluate the air-kerma, some correction factors such as electron-loss correction factor (ke) and photon scattering correction factor (ksc) are needed. ke factor corrects the charge loss from the collecting volume and ksc factor corrects the scattering of photons into collecting volume. In this work ke and ksc were estimated by Monte Carlo simulation. These correction factors are calculated for mono-energy photon. As a result of the simulation data, the ke and ksc values for FAC-IR-300 ionization chamber are 1.0704 and 0.9982, respectively.

  13. Factors Involved in Iranian Women Heads of Household’s Health Promotion Activities: A Grounded Theory Study

    PubMed Central

    Rafii, Forough; Seyedfatemi, Naima; Rezaei, Mahboubeh

    2013-01-01

    We aimed to explore and describe the factors involved in Iranian women heads of household’s health promotion activities. Grounded theory was used as the method. Sixteen women heads of household were recruited. Data were generated by semi structured interviews. Our findings indicated that remainder of resources (money, time and energy) alongside perceived severity of health risk were two main factors whereas women’s personal and socio-economic characteristics were two contextual factors involved in these women's health promotion activities. To help these women improve their health status, we recommended that the government, non-governmental organizations and health care professionals provide them with required resources and increase their knowledge by holding training sessions. PMID:24039645

  14. The risk factors of head and neck cancer and their general patterns in Australia: a descriptive review and update.

    PubMed

    Singh, Jagtar; Ramamoorthi, Ramya; Baxi, Siddhartha; Jayaraj, Rama; Thomas, Mahiban

    2014-01-01

    The purpose of this article is to provide a descriptive review of risk factors of head and neck cancer (HNC), with particular interest in their general patterns in Australia. All these risk factors are deeply perplexing, with socioeconomic, cultural, and geographic variables. We reviewed articles from PubMed, MEDLINE, and Google Scholar by using keywords such as risk factors, alcohol, tobacco, human papilloma virus (HPV), environmental risk factors, and other risk factors. We selected relevant articles after they completely fit into the inclusion criteria for this review. Previous reports highlight that smoking tobacco, consuming alcohol, and HPV infection are the major risk factors for HNC. Geographical variations in incidence rates are indicative of differences in the prevalence of risk factors among countries. HNC could be prevented by reducing the prevalence of established risk factors.

  15. Confounding factors associated with oral mucositis assessment in patients receiving chemoradiotherapy for head and neck cancer.

    PubMed

    Chung, Yih-Lin; Pui, Newman N M

    2017-09-01

    The aim of this study was to identify patient-centered, mucositis-associated adverse impact factors and events that might confound physician-assessed oral mucositis (OM) in head and neck cancer (HNC) patients receiving chemoradiotherapy. This was a post hoc analysis of a previously conducted randomized trial to determine the efficacy of 5% phenylbutyrate mouthwash in preventing chemoradiotherapy-induced OM. This analysis identified patient-centered symptomatic, observable, and measurable factors that may confound physician scoring of the severity of OM during chemoradiotherapy. Confounding factors were then combined with physician-rated OM scores according to World Health Organization (WHO) and OM Assessment Scale (OMAS) criteria to investigate the therapeutic implications of OM treatment. The original analysis found no significant differences between experimental and placebo groups with respect to the cumulative incidence of physician-recorded severe OM (WHO ≥3 or OMAS ≥2), patient-reported adverse events, and opioid use. However, patients in the experimental arm had relatively lower rates of OM-associated adverse clinical issues including unplanned short radiation breaks, skipping of chemotherapy, nausea/vomiting, late loss of body weight, and early opioid use, all of which could potentially interfere with physician-assessed OM scoring. When WHO OM grade (functional impact and pain), OMAS ulceration size (organic impact), and prolonged radiation treatment time (cancer treatment impact) were combined, there were significantly fewer interruptions of chemoradiotherapy treatment in symptomatic OM patients in the experimental compared to the placebo group. The benefits conferred by reducing the amount of chemoradiotherapy-related, OM-associated adverse impacts in the experimental group were reflected by better 5-year locoregional recurrence-free survival. This exploratory study raises questions as to whether the severity reflected by physician-rated OM scores is

  16. Electron scattering form factors of stretched transitions using Woods-Saxon wave functions

    NASA Astrophysics Data System (ADS)

    Clausen, B. L.; Peterson, R. J.; Lindgren, R. A.

    1988-08-01

    Electron scattering form factors for stretched transitions are computed using radial wave functions from realistic nuclear potentials, including the unbound nature of final states above particle decay thresholds. The calculated form factors are compared to data for 4- states in 12C, 14C, and 16O, 6- states in 24Mg, 26Mg, and 28Si, 8- states in 48Ca, 54Fe, 58Ni, and 60Ni, the 10- state in 90Zr, and the 14- state in 208Pb. We assess the fraction of the single-particle sum rule strengths using these realistic nuclear potentials in place of the standard results using harmonic oscillator wave functions. Appreciably greater fractions are obtained for low mass nuclei in the present work, totalling 105% of the sum strength for 12C and 81% for 16O. Much less damping of the magnetic strength is thus experimentally observed than is the case when oscillator wave functions are used for comparison. The results of including meson exchange currents in the analysis are also discussed.

  17. An uncleavable form of pro–scatter factor suppresses tumor growth and dissemination in mice

    PubMed Central

    Mazzone, Massimiliano; Basilico, Cristina; Cavassa, Silvia; Pennacchietti, Selma; Risio, Mauro; Naldini, Luigi; Comoglio, Paolo M.; Michieli, Paolo

    2004-01-01

    Scatter factor (SF), also known as hepatocyte growth factor, is ubiquitously present in the extracellular matrix of tissues in the form of an inactive precursor (pro-SF). In order to acquire biological activity, pro-SF must be cleaved by specific proteases present on the cell surface. The mature form of SF controls invasive cues in both physiological and pathological processes through activation of its receptor, the Met tyrosine kinase. By substituting a single amino acid in the proteolytic site, we engineered an unprocessable form of pro-SF (uncleavable SF). Using lentivirus vector technology, we achieved local or systemic delivery of uncleavable SF in mice. We provide evidence that (a) uncleavable SF inhibits both protease-mediated pro-SF conversion and active SF–induced Met activation; (b) local expression of uncleavable SF in tumors suppresses tumor growth, impairs tumor angiogenesis, and prevents metastatic dissemination; and (c) systemic expression of uncleavable SF dramatically inhibits the growth of transplanted tumors and abolishes the formation of spontaneous metastases without perturbing vital physiological functions. These data show that proteolytic activation of pro-SF is a limiting step in tumor progression, thus suggesting a new strategy for the treatment or prevention of the malignant conversion of neoplastic lesions. PMID:15545993

  18. An uncleavable form of pro-scatter factor suppresses tumor growth and dissemination in mice.

    PubMed

    Mazzone, Massimiliano; Basilico, Cristina; Cavassa, Silvia; Pennacchietti, Selma; Risio, Mauro; Naldini, Luigi; Comoglio, Paolo M; Michieli, Paolo

    2004-11-01

    Scatter factor (SF), also known as hepatocyte growth factor, is ubiquitously present in the extracellular matrix of tissues in the form of an inactive precursor (pro-SF). In order to acquire biological activity, pro-SF must be cleaved by specific proteases present on the cell surface. The mature form of SF controls invasive cues in both physiological and pathological processes through activation of its receptor, the Met tyrosine kinase. By substituting a single amino acid in the proteolytic site, we engineered an unprocessable form of pro-SF (uncleavable SF). Using lentivirus vector technology, we achieved local or systemic delivery of uncleavable SF in mice. We provide evidence that (a) uncleavable SF inhibits both protease-mediated pro-SF conversion and active SF-induced Met activation; (b) local expression of uncleavable SF in tumors suppresses tumor growth, impairs tumor angiogenesis, and prevents metastatic dissemination; and (c) systemic expression of uncleavable SF dramatically inhibits the growth of transplanted tumors and abolishes the formation of spontaneous metastases without perturbing vital physiological functions. These data show that proteolytic activation of pro-SF is a limiting step in tumor progression, thus suggesting a new strategy for the treatment or prevention of the malignant conversion of neoplastic lesions.

  19. Measuring the neutral weak form factors in e-N scattering: the G^0 Expriment

    NASA Astrophysics Data System (ADS)

    King, Paul

    2001-10-01

    The G^0 experiment(JLab experiment E00-006, D.H. Beck, spokesperson.) will measure the parity-violating asymmetries in elastic electron-nucleon scattering. The experiment will be performed in Hall C at Jefferson Lab using a dedicated apparatus, with the first running period planned to begin in the summer of 2002. Using measurements of the electron-proton asymmetries at forward and backward angles and the electron-deuteron asymmetries at backward angles over the momentum transfer range of 0.1 - 1.0 GeV^2/c^2, the vector neutral weak form factors, G_E^Z and G_M^Z, and the effective axial current of the nucleon, G_A^e, will be extracted. Combining the neutral weak and the known electromagnetic form factors allows one to experimentally extract the contributions of u, d, and s quarks to the proton's charge and magnetization distributions. An overview of the physics of the G^0 experiment will be presented.

  20. Measuring the Low Energy Nuclear Quenching Factor in Liquid Argon for a Coherent Neutrino Scatter Detector

    NASA Astrophysics Data System (ADS)

    Foxe, M.; Bernstein, A.; Hagmann, C.; Joshi, T.; Jovanovic, I.; Kazkaz, K.; Sangiorgio, S.

    2012-08-01

    Coherent neutrino-nucleus scattering (CNS) is an as-yet undetected, flavor-independent neutrino interaction predicted by the Standard Model [D. Freedman, Phys. Rev. D 9 (5) (1974) 1389-1392]. One of the primary reasons the CNS interaction has yet to be observed is the very low energy depositions (less than 1 keV for MeV-energy neutrinos) [A. Drukier, L. Stodolsky, Phys. Rev. D 30 (11) (1984) 2295-2309]. An additional challenge in detecting CNS is nuclear quenching, which is a phenomenon encountered in many detection materials in which nuclear recoils produce less observable energy per unit energy deposited than electronic recoils. The ratio observed signal for nuclear recoils to electronic recoils or nuclear ionization quench factor, is presently unknown in argon at typical CNS energies [C. Hagmann, A. Bernstein, IEEE Trans. on Nucl. Sci. 51 (5) (2004) 2151-2155]. Here we present plans for using the Gamma or Neutron Argon Recoils Resulting in Liquid Ionization (G/NARRLI) detector to measure the nuclear ionization quench factor at ˜8 keV.

  1. Scattering cross-section emission factors for visibility and radiative transfer applications: military vehicles traveling on unpaved roads.

    PubMed

    Moosmüller, Hans; Varma, Ravi; Arnott, W Patrick; Kuhns, Hampden D; Etyemezian, Vicken; Gillies, John A

    2005-11-01

    Emission factors for particulate matter (PM) are generally reported as mass emission factors (PM mass emitted per time or activity) as appropriate for air quality standards based on mass concentration. However, for visibility and radiative transfer applications, scattering, absorption, and extinction coefficients are the parameters of interest, with visibility standards based on extinction coefficients. These coefficients (dimension of inverse distance) equal cross-section concentrations, and, therefore, cross-section emission factors are appropriate. Scattering cross-section emission factors were determined for dust entrainment by nine vehicles, ranging from light passenger vehicles to heavy military vehicles, traveling on an unpaved road. Each vehicle made multiple passes at multiple speeds while scattering and absorption coefficients, wind velocity and dust plume profiles, and additional parameters were measured downwind of the road. Light absorption of the entrained PM was negligible, and the light extinction was primarily caused by scattering. The resulting scattering cross-section emission factors per vehicle kilometer traveled (vkt) range from 12.5 m2/vkt for a slow (16 km/ hr), light (1176 kg) vehicle to 3724 m2/vkt for a fast (64 km/hr), heavy (17,727 kg) vehicle and generally increase with vehicle speed and mass. The increase is approximately linear with speed, yielding emission factors per vkt and speed ranging from 4.2 m2/(vkt km/hr) to 53 m2/(vkt km/hr). These emission factors depend approximately linearly on vehicle mass within the groups of light (vehicle mass < or =3100 kg) and heavy (vehicle mass >8000 kg) vehicles yielding emission factors per vkt, speed, and mass of 0.0056 m2/(vkt km/hr kg) and 0.0024 m2/(vkt km/hr kg), respectively. Comparison of the scattering cross-section and PM mass emission factors yields average mass scattering efficiencies of 1.5 m2/g for the light vehicles and of 0.8 m2/g for the heavy vehicles indicating that the heavy

  2. Simulation of the shape of chaperonins using the small-angle x-ray scattering curves and torus form factor

    SciTech Connect

    Amarantov, S. V.; Naletova, I. N.; Kurochkina, L. P.

    2011-08-15

    The inverse scattering problem has been solved for protein complexes whose surfaces can be described by a set of the simplest doubly connected surfaces in the uniform approximation (a scattering potential inside the molecule is a constant). Solutions of two proteins-well-known GroEL bacterial chaperonin and poor-studied bacteriophage chaperonin, which is a product of 146 gene (gp146)-were taken for the experiment. The shapes of protein complexes have been efficiently reconstructed from the experimental scattering curves. The shell method, the method of the rotation of amino acid sequences with the use of the form factor of an amino acid, and the method of seeking the model parameters of a protein complex with the preliminarily obtained form factor of the model have been used to reconstruct the shape of these particles.

  3. Dose-volume factors correlating with trismus following chemoradiation for head and neck cancer

    PubMed Central

    RAO, SHYAM D.; SALEH, ZIAD H.; SETTON, JEREMY; TAM, MOSES; MCBRIDE, SEAN M.; RIAZ, NADEEM; DEASY, JOSEPH O.; LEE, NANCY Y.

    2016-01-01

    Background To investigate the dose-volume factors in mastication muscles that are implicated as possible causes of trismus in patients following treatment with intensity-modulated radiotherapy (IMRT) and concurrent chemotherapy for head and neck cancers. Material and methods All evaluable patients treated at our institution between January 2004 and April 2009 with chemotherapy and IMRT for squamous cell cancers of the oropharynx, nasopharynx, hypopharynx or larynx were included in this analysis (N = 421). Trismus was assessed using CTCAE 4.0. Bi-lateral masseter, temporalis, lateral pterygoid and medial pterygoid muscles were delineated on axial computed tomography (CT) treatment planning images, and dose-volume parameters were extracted to investigate univariate and multimetric correlations. Results Forty-six patients (10.9%) were observed to have chronic trismus of grade 1 or greater. From analysis of baseline patient characteristics, toxicity correlated with primary site and patient age. From dose-volume analysis, the steepest dose thresholds and highest correlations were seen for mean dose to ipsilateral masseter (Spearman’s rank correlation coefficient Rs = 0.25) and medial pterygoid (Rs = 0.23) muscles. Lyman-Kutcher-Burman modeling showed highest correlations for the same muscles. The best correlation for multimetric logistic regression modeling was with V68Gy to the ipsilateral medial pterygoid (Rs = 0.29). Conclusion Chemoradiation-induced trismus remains a problem particularly for patients with oropharyngeal carcinoma. Strong dose-volume correlations support the hypothesis that limiting dose to the ipsilateral masseter muscle and, in particular, the medial pterygoid muscle may reduce the likelihood of trismus. PMID:25920361

  4. Dose-volume factors correlating with trismus following chemoradiation for head and neck cancer.

    PubMed

    Rao, Shyam D; Saleh, Ziad H; Setton, Jeremy; Tam, Moses; McBride, Sean M; Riaz, Nadeem; Deasy, Joseph O; Lee, Nancy Y

    2016-01-01

    To investigate the dose-volume factors in mastication muscles that are implicated as possible causes of trismus in patients following treatment with intensity-modulated radiotherapy (IMRT) and concurrent chemotherapy for head and neck cancers. All evaluable patients treated at our institution between January 2004 and April 2009 with chemotherapy and IMRT for squamous cell cancers of the oropharynx, nasopharynx, hypopharynx or larynx were included in this analysis (N = 421). Trismus was assessed using CTCAE 4.0. Bi-lateral masseter, temporalis, lateral pterygoid and medial pterygoid muscles were delineated on axial computed tomography (CT) treatment planning images, and dose-volume parameters were extracted to investigate univariate and multimetric correlations. Forty-six patients (10.9%) were observed to have chronic trismus of grade 1 or greater. From analysis of baseline patient characteristics, toxicity correlated with primary site and patient age. From dose-volume analysis, the steepest dose thresholds and highest correlations were seen for mean dose to ipsilateral masseter (Spearman's rank correlation coefficient Rs = 0.25) and medial pterygoid (Rs = 0.23) muscles. Lyman-Kutcher-Burman modeling showed highest correlations for the same muscles. The best correlation for multimetric logistic regression modeling was with V68Gy to the ipsilateral medial pterygoid (Rs = 0.29). Chemoradiation-induced trismus remains a problem particularly for patients with oropharyngeal carcinoma. Strong dose-volume correlations support the hypothesis that limiting dose to the ipsilateral masseter muscle and, in particular, the medial pterygoid muscle may reduce the likelihood of trismus.

  5. Trismus in head and neck cancer patients in Sweden: incidence and risk factors.

    PubMed

    Johnson, Joakim; van As-Brooks, Corina J; Fagerberg-Mohlin, Bodil; Finizia, Caterina

    2010-06-01

    The aim was to retrospectively investigate trismus (reduced mandible mobility) development in specified head and neck (H&N) cancer diagnosis according to different radiotherapy dosage regimens. Sixty-nine out of 246 patients with different H&N cancer diagnoses and available maximum interincisal opening (MIO) measurements before and after treatment were analyzed according to age, gender, radiation dose, tumor site and stage, and Karnofsky Performance Status Scale index. MIO was measured over time (range: 3-48 months), with a cutoff criterion for trismus of 35 mm. Overall, 42% of the patients had post-treatment MIO <35 mm, and trismus incidence was highest in patients treated for parotid gland tumors followed by those treated for nasopharyngeal cancers. The mean MIO values at baseline were significantly different (p=0.0078) between patients who developed trismus (i.e. MIO <35 mm; mean: 43 mm) and those who did not (mean: 51 mm). The trismus patients also had significantly larger tumors (p=0.0437), poorer physical function before start of treatment (p=0.0344), and had more often received a higher total tumor radiation dose (p=0.0418). This study reports a high incidence of trismus in H&N cancer patients after treatment. Furthermore, it was found that poor physical function before the start of treatment and high external beam radiation therapy (EBRT) dosages (>50 Gy) were related to significantly more trismus. Future prospective studies are needed to provide a better understanding of different risk factors associated with trismus development, the impact on health-related quality of life, and the effects of early treatment.

  6. Treatment of Femoral Head Necrosis With Bone Marrow Mesenchymal Stem Cells Expressing Inducible Hepatocyte Growth Factor.

    PubMed

    Pan, Zhi-Min; Zhang, Yu; Cheng, Xi-Gao; Gao, Gui-Cheng; Wang, Xiang-Rui; Cao, Kai

    Our study assessed the effect of bone marrow mesenchymal stem cells (BMSCs) expressing inducible hepatocyte growth factor (HGF) on the recovery of femoral head necrosis (FHN). BMSCs were isolated by density gradient centrifugation. A recombinant AdTRE-HGF was constructed as the response plasmid and Adeno-X Tet-on as the regulator vector. The regulator and the response vectors were coinfected into BMSCs and induced at 0, 200, 500, 1000, and 1200 ng/mL doxycycline (Dox). After 3 days, the concentration of HGF was determined using enzyme-linked immunosorbent assay. Forty rabbits were selected to establish the FHN model and divided into 4 experimental groups. After the rabbits were killed by ketamine overdose, the restoration of FHN was assessed. The distribution of HGF-positive cells was observed by immunohistochemical method. Enzyme-linked immunosorbent assay results showed that 1000 ng/mL Dox induced the highest HGF expression level, even higher than the 1200 ng/mL Dox induction. The highest osteonecrosis incidence and empty lacunae percentage were found in group A compared with all the other groups (all P < 0.05). Furthermore, dramatically lower osteonecrosis incidence and empty lacunae percentage were found in group C compared with those of groups B and D (all P < 0.05). A significantly higher level of HGF protein was detected in group C compared with the other groups (all P < 0.05). Our study successfully developed the AdTRE-HGF, a recombinant adenovirus carrying HGF gene, for high expression of HGF in BMSCs. Importantly, introduction of BMSCs expressing HGF successfully produced the desired therapeutic effect in reversing FHN, in a Dox-dependent manner.

  7. Epidermal growth factor receptor targeted therapy in stages III and IV head and neck cancer.

    PubMed

    Cripps, C; Winquist, E; Devries, M C; Stys-Norman, D; Gilbert, R

    2010-06-01

    What are the benefits associated with the use of anti-epidermal growth factor receptor (anti-EGFR) therapies in squamous cell carcinoma of the head and neck (HNSCC)? Anti-EGFR therapies of interest included cetuximab, gefitinib, lapatinib, zalutumumab, erlotinib, and panitumumab. Head-and-neck cancer includes malignant tumours arising from a variety of sites in the upper aerodigestive tract. The most common histologic type is squamous cell carcinoma, and most common sites are the oral cavity, the oropharynx, the hypopharynx, and the larynx. Worldwide, HNSCC is the sixth most common neoplasm, and despite advances in therapy, long-term survival in HNSCC patients is poor. Primary surgery followed by chemoradiation, or primary chemoradiation, are the standard treatment options for patients with locally advanced (stages III-IVB) HNSCC; however, meta-analytic data indicate that the benefit of concurrent platinum-based chemotherapy disappears in patients over the age of 70 years. Cetuximab is a monoclonal antibody approved for use in combination with radiation in the treatment of patients with untreated locally advanced HNSCC and as monotherapy for patients with recurrent or metastatic (stage IVC) HNSCC who have progressed on platinum-based therapy. Given the interest in anti-EGFR agents in advanced HNSCC, the Head and Neck Cancer Disease Site Group (DSG) of Cancer Care Ontario's Program in Evidence-Based Care (PEBC) chose to systematically review the literature pertaining to this topic so as to develop evidence-based recommendations for treatment. Outcomes of interest included overall and progression-free survival, quality of life, tumour response rate and duration, and the toxicity associated with the use of anti-EGFR therapies. The medline, embase, and Cochrane Library databases, the American Society of Clinical Oncology online conference proceedings, the Canadian Medical Association InfoBase, and the National Guidelines Clearinghouse were systematically searched to

  8. Microscopic analysis of the cellular events during scatter factor/hepatocyte growth factor-induced epithelial tubulogenesis.

    PubMed

    Williams, M J; Clark, P

    2003-11-01

    Scatter factor/hepatocyte growth factor (SF/HGF), a large multifunctional polypeptide growth and motility factor, is known to play important roles during embryonic development, adult tissue growth and repair. In an established three-dimensional type I collagen model, SF/HGF induces Madin-Darby canine kidney (MDCK) epithelial cysts to form long, branching tubules (tubulogenesis). In addition, the composition of the surrounding extracellular matrix (ECM) has been shown to modulate SF/HGF-induced morphogenesis, where tubulogenesis was completely abrogated in Matrigel basement membrane. Many cellular events that occur during SF/HGF-mediated remodelling, and its modulation by the ECM, remain unclear. We have investigated these mechanisms through microscopic examination of the time-course of SF/HGF-induced responses in MDCK cysts cultured in type I collagen or Matrigel. We found that early responses to SF/HGF were matrix-independent. Changes included increased paracellular spacing between normally closely apposed lateral membranes, and the formation of filopodial processes, indicating a partial motile response. Cell-cell contact was maintained, with the persistence of cell junctions. Therefore, while one or a number of ECM components are preventing SF/HGF-primed cells from undergoing an invasive and/or migratory programme, non-permissive matrices are not preventing SF/HGF signalling to the cell. Later matrix-dependent responses, which occurred in type I collagen but not Matrigel, included the formation of basal protrusions that comprise two or more neighbouring cells, which extend to form nascent tubules. Modified polarity of cells comprising the basal protrusions was evident, with a marker for the apical membrane being found in the same region as adherens junctions and desmosomes, typically localized at lateral membranes. We propose a model for SF/HGF-induced tubulogenesis in which tubules form from basal protrusions of adjacent cells. This mechanism of in vitro tubule

  9. Chiral dynamics in form factors, spectral-function sum rules, meson-meson scattering and semilocal duality

    NASA Astrophysics Data System (ADS)

    Guo, Zhi-Hui; Oller, J. A.; de Elvira, J. Ruiz

    2012-09-01

    In this work, we perform the one-loop calculation of the scalar and pseudoscalar form factors in the framework of U(3) chiral perturbation theory with explicit tree level exchanges of resonances. The meson-meson scattering calculation from Guo and Oller [Phys. Rev. DPRVDAQ1550-7998 84, 034005 (2011)10.1103/PhysRevD.84.034005] is extended as well. The spectral functions of the nonet scalar-scalar (SS) and pseudoscalar-pseudoscalar (PP) correlators are constructed by using the corresponding form factors. After fitting the unknown parameters to the scattering data, we discuss the resonance content of the resulting scattering amplitudes. We also study spectral-function sum rules in the SS-SS, PP-PP, and SS-PP sectors as well as semilocal duality from scattering. The former relate the scalar and pseudoscalar spectra between themselves while the latter mainly connects the scalar spectrum with the vector one. Finally we investigate these items as a function of NC for NC>3. All these results pose strong constraints on the scalar dynamics and spectroscopy that are discussed. They are successfully fulfilled by our meson-meson scattering amplitudes and spectral functions.

  10. Predictive Factors of Survival and 6-Month Favorable Outcome of Very Severe Head Trauma Patients; a Historical Cohort Study

    PubMed Central

    Vathanalaoha, Karin; Oearsakul, Thakul; Tunthanathip, Thara

    2017-01-01

    Introduction: Very severe head trauma cases, defined as Glasgow Coma Scale (GCS) scores of less than 6, have a higher mortality rate and poorer outcome. The purpose of this study was to recognize factors associated with survival and 6-month favorable outcome of very severe head trauma patients presenting to emergency department. Methods: In this historical cohort study, the authors retrospectively reviewed medical records of head trauma patients who were admitted to the emergency department with post-resuscitation GCS scores of less than 6. Both univariate and multivariate analyses were used to test the association between various parameters with survival and 6-month outcome. Results: 103 cases with the mean age of 39 ± 16.5 years were studied (80% male). The overall survival rate was 41.7% and the rate of 6-month favorable outcome was 28.2%. In multivariate analysis, brisk pupil light reaction on admission and patent basal cistern on brain computed tomography (CT) scan were significant factors associated with both survival (OR 5.20, 95% CI 1.57-17.246, p = 0.007 and OR 3.65, 95% CI 1.22-10.91, p=0.02 respectively) and favorable outcome (OR 4.07, 95% CI 1.35-12.24, p=0.01 and OR 3.54, 95% CI 1.22-10.26, p 0.02), respectively. Conclusion: Based on the results of present study, the survival rate of patients with very severe head trauma (GCS < 6) was 41.7%. The strong predictors of survival and 6-month favorable outcome of these patients were brisk pupillary reactivity and patent cistern on brain CT scan. It seems that very severe head trauma patients still have a reasonable chance to survive and aggressive management should be continued. PMID:28286831

  11. Context-specific function of the LIM homeobox 1 transcription factor in head formation of the mouse embryo.

    PubMed

    Fossat, Nicolas; Ip, Chi Kin; Jones, Vanessa J; Studdert, Joshua B; Khoo, Poh-Lynn; Lewis, Samara L; Power, Melinda; Tourle, Karin; Loebel, David A F; Kwan, Kin Ming; Behringer, Richard R; Tam, Patrick P L

    2015-06-01

    Lhx1 encodes a LIM homeobox transcription factor that is expressed in the primitive streak, mesoderm and anterior mesendoderm of the mouse embryo. Using a conditional Lhx1 flox mutation and three different Cre deleters, we demonstrated that LHX1 is required in the anterior mesendoderm, but not in the mesoderm, for formation of the head. LHX1 enables the morphogenetic movement of cells that accompanies the formation of the anterior mesendoderm, in part through regulation of Pcdh7 expression. LHX1 also regulates, in the anterior mesendoderm, the transcription of genes encoding negative regulators of WNT signalling, such as Dkk1, Hesx1, Cer1 and Gsc. Embryos carrying mutations in Pcdh7, generated using CRISPR-Cas9 technology, and embryos without Lhx1 function specifically in the anterior mesendoderm displayed head defects that partially phenocopied the truncation defects of Lhx1-null mutants. Therefore, disruption of Lhx1-dependent movement of the anterior mesendoderm cells and failure to modulate WNT signalling both resulted in the truncation of head structures. Compound mutants of Lhx1, Dkk1 and Ctnnb1 show an enhanced head truncation phenotype, pointing to a functional link between LHX1 transcriptional activity and the regulation of WNT signalling. Collectively, these results provide comprehensive insight into the context-specific function of LHX1 in head formation: LHX1 enables the formation of the anterior mesendoderm that is instrumental for mediating the inductive interaction with the anterior neuroectoderm and LHX1 also regulates the expression of factors in the signalling cascade that modulate the level of WNT activity.

  12. Patterns, aetiology and risk factors of intimate partner violence-related injuries to head, neck and face in Chinese women

    PubMed Central

    2014-01-01

    Background Intimate partner violence (IPV) related injuries have been recognized among health care professionals. However, few studies have provided detailed information on injuries to the head, neck and face regions in Chinese women. As abused Chinese women are generally unwilling to disclose IPV and there are differences in socio-demographic characteristics, societal norms and behaviours, the women may exhibit different patterns, aetiology and risk factors of IPV-related HNF injuries. This study aims to examine the patterns of head, neck and face injuries presenting to Accident and Emergency departments, including the anatomical regions, types, severity, aetiology and demographic and non-demographic risk factors of injuries inflicted by intimate partners in Chinese context. Methods Medical charts of 223 women presented to the Accident and Emergency departments of two regional hospitals in Hong Kong between January 2010 and December 2011 were reviewed independently by two reviewers. Results Head, neck and face injuries remained the most common injuries found in abused Chinese women (77.6%), and punching with a fist was the most common aetiology (60.2%). In particular, punching with a fist was significantly associated on the upper third of the maxillofacial region (p = .01) and the back part of the head (p = .03). Moreover, cohabiting and separated women were more likely to have multiple injuries than those who were married (OR = 3.3, 95% CI = 1.4, 7.8; OR = 2.1, 95% CI = .4, 11.9). Conclusions The findings enhance the understanding of head, neck and face injuries and inform clinicians about the linkage among injuries and risks in abused Chinese women. PMID:24410868

  13. Risk factors for cervical lymph node metastasis in superficial head and neck squamous cell carcinoma.

    PubMed

    Sasaki, Toru; Kishimoto, Seiji; Kawabata, Kazuyoshi; Sato, Yukiko; Tsuchida, Tomohiro

    2015-03-30

    The necessity of transoral surgery for head and neck carcinoma is increasing, but its indications for the treatment of superficial head and neck carcinomas have not yet been established. This study was intended to help establish the standard indications for transoral surgery and additional therapy in patients with superficial head and neck carcinoma. Sixty-two patients with 83 superficial head and neck carcinoma underwent transoral tumor resection at the Cancer Institute Hospital between June 2006 and September 2011. We measured the tumor size and thickness, examined the gross appearance, permeation of vessels, and droplet infiltration, and analyzed the correlations between each parameter. Sessile type of tumor on gross appearance showed a significantly higher incidence of thickness≥1000 µm than the other types. Tumor thickness≥1000 µm was associated with higher incidences of permeation of vessels, droplet infiltration, and cervical lymph node metastasis. In superficial head and neck carcinoma, if the endoscopic gross appearance is the sessile type, tumor thickness is likely to be ≥1000 µm and risk of cervical lymph node metastasis is increased.

  14. Cubilin, a High Affinity Receptor for Fibroblast Growth Factor 8, Is Required for Cell Survival in the Developing Vertebrate Head*

    PubMed Central

    Cases, Olivier; Perea-Gomez, Aitana; Aguiar, Diego P.; Nykjaer, Anders; Amsellem, Sabine; Chandellier, Jacqueline; Umbhauer, Muriel; Cereghini, Silvia; Madsen, Mette; Collignon, Jérôme; Verroust, Pierre; Riou, Jean-François; Creuzet, Sophie E.; Kozyraki, Renata

    2013-01-01

    Cubilin (Cubn) is a multiligand endocytic receptor critical for the intestinal absorption of vitamin B12 and renal protein reabsorption. During mouse development, Cubn is expressed in both embryonic and extra-embryonic tissues, and Cubn gene inactivation results in early embryo lethality most likely due to the impairment of the function of extra-embryonic Cubn. Here, we focus on the developmental role of Cubn expressed in the embryonic head. We report that Cubn is a novel, interspecies-conserved Fgf receptor. Epiblast-specific inactivation of Cubn in the mouse embryo as well as Cubn silencing in the anterior head of frog or the cephalic neural crest of chick embryos show that Cubn is required during early somite stages to convey survival signals in the developing vertebrate head. Surface plasmon resonance analysis reveals that fibroblast growth factor 8 (Fgf8), a key mediator of cell survival, migration, proliferation, and patterning in the developing head, is a high affinity ligand for Cubn. Cell uptake studies show that binding to Cubn is necessary for the phosphorylation of the Fgf signaling mediators MAPK and Smad1. Although Cubn may not form stable ternary complexes with Fgf receptors (FgfRs), it acts together with and/or is necessary for optimal FgfR activity. We propose that plasma membrane binding of Fgf8, and most likely of the Fgf8 family members Fgf17 and Fgf18, to Cubn improves Fgf ligand endocytosis and availability to FgfRs, thus modulating Fgf signaling activity. PMID:23592779

  15. Cubilin, a high affinity receptor for fibroblast growth factor 8, is required for cell survival in the developing vertebrate head.

    PubMed

    Cases, Olivier; Perea-Gomez, Aitana; Aguiar, Diego P; Nykjaer, Anders; Amsellem, Sabine; Chandellier, Jacqueline; Umbhauer, Muriel; Cereghini, Silvia; Madsen, Mette; Collignon, Jérôme; Verroust, Pierre; Riou, Jean-François; Creuzet, Sophie E; Kozyraki, Renata

    2013-06-07

    Cubilin (Cubn) is a multiligand endocytic receptor critical for the intestinal absorption of vitamin B12 and renal protein reabsorption. During mouse development, Cubn is expressed in both embryonic and extra-embryonic tissues, and Cubn gene inactivation results in early embryo lethality most likely due to the impairment of the function of extra-embryonic Cubn. Here, we focus on the developmental role of Cubn expressed in the embryonic head. We report that Cubn is a novel, interspecies-conserved Fgf receptor. Epiblast-specific inactivation of Cubn in the mouse embryo as well as Cubn silencing in the anterior head of frog or the cephalic neural crest of chick embryos show that Cubn is required during early somite stages to convey survival signals in the developing vertebrate head. Surface plasmon resonance analysis reveals that fibroblast growth factor 8 (Fgf8), a key mediator of cell survival, migration, proliferation, and patterning in the developing head, is a high affinity ligand for Cubn. Cell uptake studies show that binding to Cubn is necessary for the phosphorylation of the Fgf signaling mediators MAPK and Smad1. Although Cubn may not form stable ternary complexes with Fgf receptors (FgfRs), it acts together with and/or is necessary for optimal FgfR activity. We propose that plasma membrane binding of Fgf8, and most likely of the Fgf8 family members Fgf17 and Fgf18, to Cubn improves Fgf ligand endocytosis and availability to FgfRs, thus modulating Fgf signaling activity.

  16. Risk factors for free flap failure: a retrospective analysis of 881 free flaps for head and neck defect reconstruction.

    PubMed

    Zhou, W; Zhang, W-B; Yu, Y; Wang, Y; Mao, C; Guo, C-B; Yu, G-Y; Peng, X

    2017-08-01

    The aim of this study was to identify the risk factors for free flap failure after head and neck reconstructive surgery. The data of 881 consecutive patients who underwent free flap surgery at the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, between January 2013 and November 2016, were reviewed retrospectively. All surgeries were performed by a single head and neck surgical team. Patient demographic and surgical data that may have an influence on free flap outcomes were recorded. The χ(2) test and multivariate logistic regression analysis were used to identify relevant risk factors. In total, 881 free tissue transfer surgeries were included in this study. Free flap failure occurred in 26 of 881 flaps (2.9%). A history of irradiation (odds ratio 0.205, 95% confidence interval 0.07-0.56; P=0.002) was a statistically significant risk factor for free flap failure. Age, diabetes mellitus, history of previous neck surgery to the anastomosis side, donor site, choice of recipient vein, use of a coupler device, and postoperative anticoagulation were not associated with free flap outcomes. Thus, it is concluded that when performing head and neck reconstructive surgery, special attention should be paid to patients who have previously undergone irradiation. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  17. Myofascial pain syndrome after head and neck cancer treatment: Prevalence, risk factors, and influence on quality of life.

    PubMed

    Cardoso, Leticia Rodrigues; Rizzo, Cláudia Carvalho; de Oliveira, Cleyton Zanardo; dos Santos, Carlos Roberto; Carvalho, André Lopes

    2015-12-01

    Patients undergoing treatment for head and neck cancer may develop myofascial pain syndrome as sequelae. The purpose of this study was to determine the prevalence, risk factors, and quality of life (QOL) related to myofascial pain syndrome. This was a prospective study including patients with head and neck cancer with at least a 1-year disease-free interval. One hundred sixty-seven patients were analyzed, and myofascial pain syndrome was diagnosed in 20 (11.9%). In the multivariate analysis, hypopharyngeal tumors (odds ratio [OR] = 6.35; 95% confidence interval [CI] = 1.58-25.56) and neck dissection (OR = 3.43; 95% CI = 1.16-10.17) were independent factors for myofascial pain syndrome. The pain (p < .001) and shoulder domain (p < .001) as well as overall University of Washington Quality of Life (UW-QOL) score (p = .006) were significantly lower in the patients with myofascial pain syndrome. Myofascial pain syndrome was observed in 1 of 9 patients after head and neck cancer treatment and a worse QOL was observed among them. Tumor site and neck dissection were found to be risk factors for myofascial pain syndrome. © 2014 Wiley Periodicals, Inc.

  18. Impact of targeting insulin-like growth factor signaling in head and neck cancers.

    PubMed

    Limesand, Kirsten H; Chibly, Alejandro Martinez; Fribley, Andrew

    2013-10-01

    The IGF system has been shown to have either negative or negligible impact on clinical outcomes of tumor development depending on specific tumor sites or stages. This review focuses on the clinical impact of IGF signaling in head and neck cancer, the effects of IGF targeted therapies, and the multi-dimensional role of IRS 1/2 signaling as a potential mechanism in resistance to targeted therapies. Similar to other tumor sites, both negative and positive correlations between levels of IGF-1/IGF-1-R and clinical outcomes in head and neck cancer have been reported. In addition, utilization of IGF targeted therapies has not demonstrated significant clinical benefit; therefore the prognostic impact of the IGF system on head and neck cancer remains uncertain.

  19. Roles of hepatocyte growth factor/scatter factor and the met receptor in the early development of the metanephros

    PubMed Central

    1995-01-01

    Several lines of evidence suggest that hepatocyte growth factor/scatter factor (HGF/SF), a soluble protein secreted by embryo fibroblasts and several fibroblast lines, may elicit morphogenesis in adjacent epithelial cells. We investigated the role of HGF/SF and its membrane receptor, the product of the c-met protooncogene, in the early development of the metanephric kidney. At the inception of the mouse metanephros at embryonic day 11, HGF/SF was expressed in the mesenchyme, while met was expressed in both the ureteric bud and the mesenchyme, as assessed by reverse transcription PCR, in situ hybridization, and immunohistochemistry. To further investigate the expression of met in renal mesenchyme, we isolated 13 conditionally immortal clonal cell lines from transgenic mice expressing a temperature-sensitive mutant of the SV-40 large T antigen. Five had the HGF/SF+/met+ phenotype and eight had the HGF/SF-/met+ phenotype. None had the HGF/SF+/met- nor the HGF/SF-/met- phenotypes. Thus the renal mesenchyme contains cells that express HGF/SF and met or met alone. When metanephric rudiments were grown in serum-free organ culture, anti- HGF/SF antibodies (a) inhibited the differentiation of metanephric mesenchymal cells into the epithelial precursors of the nephron; (b) increased cell death within the renal mesenchyme; and (c) perturbed branching morphogenesis of the ureteric bud. These data provide the first demonstration for coexpression of the HGF/SF and met genes in mesenchymal cells during embryonic development and also imply an autocrine and/or paracrine role for HGF/SF and met in the survival of the renal mesenchyme and in the mesenchymal-epithelial transition that occurs during nephrogenesis. They also confirm the postulated paracrine role of HGF/SF in the branching of the ureteric bud. PMID:7822413

  20. Hepatocyte growth factor/scatter factor induces a variety of tissue- specific morphogenic programs in epithelial cells

    PubMed Central

    1995-01-01

    Hepatocyte growth factor/scatter factor (HGF/SF) is the mesenchymal ligand of the epithelial tyrosine kinase receptor c-Met. In vitro, HGF/SF has morphogenic properties, e.g., induces kidney epithelial cells to form branching ducts in collagen gels. Mutation of the HGF/SF gene in mice results in embryonic lethality due to severe liver and placenta defects. Here, we have evaluated the morphogenic activity of HGF/SF with a large variety of epithelial cells grown in three- dimensional collagen matrices. We found that HGF/SF induces SW 1222 colon carcinoma cells to form crypt-like structures. In these organoids, cells exhibit apical/basolateral polarity and build a well- developed brush border towards the lumen. Capan 2 pancreas carcinoma cells, upon addition of HGF/SF, develop large hollow spheroids lined with a tight layer of polarized cells. Collagen inside the cysts is digested and the cells show features of pancreatic ducts. HGF/SF induces EpH4 mammary epithelial cells to form long branches with end- buds that resemble developing mammary ducts. pRNS-1-1 prostate epithelial cells in the presence of HGF/SF develop long ducts with distal branching as found in the prostate. Finally, HGF/SF simulates alveolar differentiation in LX-1 lung carcinoma cells. Expression of transfected HGF/SF cDNA in LX-1 lung carcinoma and EpH4 mammary epithelial cells induce morphogenesis in an autocrine manner. In the cell lines tested, HGF/SF activated the Met receptor by phosphorylation of tyrosine residues. These data show that HGF/SF induces intrinsic, tissue-specific morphogenic activities in a wide variety of epithelial cells. Apparently, HGF/SF triggers respective endogenous programs and is thus an inductive, not an instructive, mesenchymal effector for epithelial morphogenesis. PMID:8522613

  1. Parity-Violating Electron Scattering from 4He and the Strange Electric Form Factor of the Nucleon

    NASA Astrophysics Data System (ADS)

    Aniol, K. A.; Armstrong, D. S.; Averett, T.; Benaoum, H.; Bertin, P. Y.; Burtin, E.; Cahoon, J.; Cates, G. D.; Chang, C. C.; Chao, Y.-C.; Chen, J.-P.; Choi, Seonho; Chudakov, E.; Craver, B.; Cusanno, F.; Decowski, P.; Deepa, D.; Ferdi, C.; Feuerbach, R. J.; Finn, J. M.; Frullani, S.; Fuoti, K.; Garibaldi, F.; Gilman, R.; Glamazdin, A.; Gorbenko, V.; Grames, J. M.; Hansknecht, J.; Higinbotham, D. W.; Holmes, R.; Holmstrom, T.; Humensky, T. B.; Ibrahim, H.; de Jager, C. W.; Jiang, X.; Kaufman, L. J.; Kelleher, A.; Kolarkar, A.; Kowalski, S.; Kumar, K. S.; Lambert, D.; Laviolette, P.; Lerose, J.; Lhuillier, D.; Liyanage, N.; Margaziotis, D. J.; Mazouz, M.; McCormick, K.; Meekins, D. G.; Meziani, Z.-E.; Michaels, R.; Moffit, B.; Monaghan, P.; Munoz-Camacho, C.; Nanda, S.; Nelyubin, V.; Neyret, D.; Paschke, K. D.; Poelker, M.; Pomatsalyuk, R.; Qiang, Y.; Reitz, B.; Roche, J.; Saha, A.; Singh, J.; Snyder, R.; Souder, P. A.; Subedi, R.; Suleiman, R.; Sulkosky, V.; Tobias, W. A.; Urciuoli, G. M.; Vacheret, A.; Voutier, E.; Wang, K.; Wilson, R.; Wojtsekhowski, B.; Zheng, X.

    2006-01-01

    We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from He4 at an average scattering angle ⟨θlab⟩=5.7° and a four-momentum transfer Q2=0.091GeV2. From these data, for the first time, the strange electric form factor of the nucleon GEs can be isolated. The measured asymmetry of APV=(6.72±0.84(stat)±0.21(syst))×10-6 yields a value of GEs=-0.038±0.042(stat)±0.010(syst), consistent with zero.

  2. Parity-violating electron scattering from 4He and the strange electric form factor of the nucleon.

    PubMed

    Aniol, K A; Armstrong, D S; Averett, T; Benaoum, H; Bertin, P Y; Burtin, E; Cahoon, J; Cates, G D; Chang, C C; Chao, Y-C; Chen, J-P; Choi, Seonho; Chudakov, E; Craver, B; Cusanno, F; Decowski, P; Deepa, D; Ferdi, C; Feuerbach, R J; Finn, J M; Frullani, S; Fuoti, K; Garibaldi, F; Gilman, R; Glamazdin, A; Gorbenko, V; Grames, J M; Hansknecht, J; Higinbotham, D W; Holmes, R; Holmstrom, T; Humensky, T B; Ibrahim, H; de Jager, C W; Jiang, X; Kaufman, L J; Kelleher, A; Kolarkar, A; Kowalski, S; Kumar, K S; Lambert, D; LaViolette, P; LeRose, J; Lhuillier, D; Liyanage, N; Margaziotis, D J; Mazouz, M; McCormick, K; Meekins, D G; Meziani, Z-E; Michaels, R; Moffit, B; Monaghan, P; Munoz-Camacho, C; Nanda, S; Nelyubin, V; Neyret, D; Paschke, K D; Poelker, M; Pomatsalyuk, R; Qiang, Y; Reitz, B; Roche, J; Saha, A; Singh, J; Snyder, R; Souder, P A; Subedi, R; Suleiman, R; Sulkosky, V; Tobias, W A; Urciuoli, G M; Vacheret, A; Voutier, E; Wang, K; Wilson, R; Wojtsekhowski, B; Zheng, X

    2006-01-20

    We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from 4He at an average scattering angle = 5.7 degrees and a four-momentum transfer Q2 = 0.091 GeV2 . From these data, for the first time, the strange electric form factor of the nucleon G(E)s can be isolated. The measured asymmetry of A(PV) = (6.72 +/- 0.84(stat) +/- 0.21(syst) x 10(-6) yields a value of G(E)s = -0.038 +/- 0.042(stat) +/- 0.010(syst), consistent with zero.

  3. Head Trauma as a Precipitating Factor for Late-onset Leigh Syndrome: a Case Report

    PubMed Central

    Ashrafi, Farzad; Pakdaman, Hossein; Arabahmadi, Mehran; Behnam, Behdad

    2017-01-01

    Leigh syndrome is a severe progressive neurodegenerative disorder with different clinical presentationsthat usually becomes apparent in the first year of life and rarely in late childhood and elderly years. It is causedby failure of mitochondrial respiratory chain and often results in regression of both mental and motor skills and might even lead to death. In some of the inherited neurodegenerative diseases like Alexander disease, head trauma is reported as a trigger for onset of the disease. We present a late onset Leigh syndrome in a 14-year-old girl whose symptoms were initiating following head trauma. PMID:28286850

  4. Limits of metastability in amorphous ices: the neutron scattering Debye-Waller factor.

    PubMed

    Amann-Winkel, Katrin; Löw, Florian; Handle, Philip H; Knoll, Wiebke; Peters, Judith; Geil, Burkhard; Fujara, Franz; Loerting, Thomas

    2012-12-21

    Recently, it became clear that relaxation effects in amorphous ices play a very important role that has previously been overlooked. The thermodynamic history of amorphous samples strongly affects their transition behavior. In particular, well-relaxed samples show higher thermal stability, thereby providing a larger window to investigate their glass transitions. We here present neutron scattering experiments using fixed elastic window scans on relaxed forms of amorphous ice, namely expanded high density amorphous ice (eHDA), a variant of low density amorphous ice (LDA-II) and hyperquenched glassy water (HGW). These amorphous ices are expected to be true glassy counterparts of deeply supercooled liquid water, therefore fast precursor dynamics of structural relaxation are expected to appear below the calorimetric glass transition temperature. The Debye-Waller factor shows a very weak sub-T(g) anomaly in some of the samples, which might be the signature of such fast precursor dynamics. However, we cannot find this behavior consistently in all samples at all reciprocal length scales of momentum transfer.

  5. Enhancement factor statistics of surface enhanced Raman scattering in multiscale heterostructures of nanoparticles

    NASA Astrophysics Data System (ADS)

    Zito, Gianluigi; Rusciano, Giulia; Sasso, Antonio

    2016-08-01

    Suitable metal nanostructures may induce surface-enhanced Raman scattering (SERS) enhancement factors (EFs) large-enough to reach single-molecule sensitivity. However, the gap hot-spot EF probability density function (PDF) has the character of a long-tail distribution, which dramatically mines the reproducibility of SERS experiments. Herein, we carry out electrodynamic calculations based on a 3D finite element method of two plasmonic nanostructures, combined with Monte Carlo simulations of the EF statistics under different external conditions. We compare the PDF produced by a homodimer of nanoparticles with that provided by a self-similar trimer. We show that the PDF is sensitive to the spatial distribution of near-field enhancement specifically supported by the nanostructure geometry. Breaking the symmetry of the plasmonic system is responsible for inducing particular modulations of the PDF tail resembling a multiple Poisson distribution. We also study the influence that molecular diffusion towards the hottest hot-spot, or selective hot-spot targeting, might have on the EF PDF. Our results quantitatively assess the possibility of designing the response of a SERS substrate so as to contain the intrinsic EF PDF variance and significantly improving, in principle, the reproducibility of SERS experiments.

  6. Covariant Spectator Theory of np scattering: Deuteron magnetic moment and form factors

    SciTech Connect

    Gross, Franz L.

    2014-06-01

    The deuteron magnetic moment is calculated using two model wave functions obtained from 2007 high precision fits to $np$ scattering data. Included in the calculation are a new class of isoscalar $np$ interaction currents which are automatically generated by the nuclear force model used in these fits. After normalizing the wave functions, nearly identical predictions are obtained: model WJC-1, with larger relativistic P-state components, gives 0.863(2), while model WJC-2 with very small $P$-state components gives 0.864(2) These are about 1\\% larger than the measured value of the moment, 0.857 n.m., giving a new prediction for the size of the $\\rho\\pi\\gamma$ exchange, and other purely transverse interaction currents that are largely unconstrained by the nuclear dynamics. The physical significance of these results is discussed, and general formulae for the deuteron form factors, expressed in terms of deuteron wave functions and a new class of interaction current wave functions, are given.

  7. Form factors of the isovector scalar current and the [Formula: see text] scattering phase shifts.

    PubMed

    Albaladejo, M; Moussallam, B

    A model for S-wave [Formula: see text] scattering is proposed which could be realistic in an energy range from threshold up to above 1 GeV, where inelasticity is dominated by the [Formula: see text] channel. The T-matrix, satisfying two-channel unitarity, is given in a form which matches the chiral expansion results at order [Formula: see text] exactly for the [Formula: see text], [Formula: see text] amplitudes and approximately for [Formula: see text]. It contains six phenomenological parameters. Asymptotic conditions are imposed which ensure a minimal solution of the Muskhelishvili-Omnès problem, thus allowing one to compute the [Formula: see text] and [Formula: see text] form factor matrix elements of the [Formula: see text] scalar current from the T-matrix. The phenomenological parameters are determined such as to reproduce the experimental properties of the [Formula: see text], [Formula: see text] resonances, as well as the chiral results of the [Formula: see text] and [Formula: see text] scalar radii, which are predicted to be remarkably small at [Formula: see text]. This T-matrix model could be used for a unified treatment of the [Formula: see text] final-state interaction problem in processes such as [Formula: see text], [Formula: see text], or the [Formula: see text] initial-state interaction in [Formula: see text].

  8. Factorization and Momentum-Space Resummation in Deep-Inelastic Scattering

    SciTech Connect

    Becher, Thomas; Neubert, Matthias; Pecjak, Ben D.; /Siegen U.

    2006-07-01

    Renormalization-group methods in soft-collinear effective theory are used to perform the resummation of large perturbative logarithms for deep-inelastic scattering in the threshold region x {yields} 1. The factorization theorem for the structure function F{sub 2}(x,Q{sup 2}) for x {yields} 1 is rederived in the effective theory, whereby contributions from the hard scale Q{sup 2} and the jet scale Q{sup 2}(1 - x) are encoded in Wilson coefficients of effective-theory operators. Resummation is achieved by solving the evolution equations for these operators. Simple analytic results for the resummed expressions are obtained directly in momentum space, and are free of the Landau-pole singularities inherent to the traditional moment-space results. We show analytically that the two methods are nonetheless equivalent order by order in the perturbative expansion, and perform a numerical comparison up to next-to-next-to-leading order in renormalization-group improved perturbation theory.

  9. Post-operative pain management in head and neck cancer patients: predictive factors and efficacy of therapy.

    PubMed

    Bianchini, C; Malagò, M; Crema, L; Aimoni, C; Matarazzo, T; Bortolazzi, S; Ciorba, A; Pelucchi, S; Pastore, A

    2016-04-01

    There is increasing interest about all aspects of pain sensation for patients undergoing head and neck surgery, and efforts have been made to better assess, monitor and reduce the occurrence of pain. The aetiology of pain is considered to be "multifactorial", as it is defined by several features such as personal experience, quality perception, location, intensity and emotional impact. The aim of this paper is: (i) to evaluate the efficacy of analgesic treatment in patients with head and neck cancer treated by surgery, and (ii) to study the variables and predictive factors that can influence the occurrence of pain. A total of 164 patients, affected by head and neck cancer and surgically treated, between December 2009 and December 2013, were included in this study. Data collected include age, gender, assessment of anaesthetic risk, tumour localisation, pathological cancer stage, TNM stage, type of surgery performed, complexity and duration of surgery, post-operative complications, postoperative days of hospital stay and pain evaluation on days 0, 1, 3 and 5 post-surgery. We studied the appropriateness of analgesic therapy in terms of incidence and prevalence of post-operative pain; we also related pain to patient characteristics, disease and surgical treatment to determine possible predictive factors. The population studied received adequate pain control through analgesic therapy immediately post-surgery and in the following days. No associations between gender, age and post-operative pain were found, whereas pathological cancer stage, complexity of surgery and tumour site were significantly associated with the risk of post-operative pain. Adequate pain control is essential in oncological patients, and particularly in head and neck cancer patients as the prevalence of pain in this localisation is reported to be higher than in other anatomical sites. Improved comprehension of the biological and psychological factors that characterise pain perception will help to

  10. Weak charge form factor and radius of 208Pb through parity violation in electron scattering

    DOE PAGES

    Horowitz, C. J.; Ahmed, Z.; Jen, C. -M.; ...

    2012-03-26

    We use distorted wave electron scattering calculations to extract the weak charge form factor FW(more » $$\\bar{q}$$), the weak charge radius RW, and the point neutron radius Rn, of 208Pb from the PREX parity violating asymmetry measurement. The form factor is the Fourier transform of the weak charge density at the average momentum transfer $$\\bar{q}$$ = 0.475 fm-1. We find FW($$\\bar{q}$$) = 0.204 ± 0.028(exp) ± 0.001(model). We use the Helm model to infer the weak radius from FW($$\\bar{q}$$). We find RW = 5.826 ± 0.181(exp) ± 0.027(model) fm. Here the exp error includes PREX statistical and systematic errors, while the model error describes the uncertainty in RW from uncertainties in the surface thickness σ of the weak charge density. The weak radius is larger than the charge radius, implying a 'weak charge skin' where the surface region is relatively enriched in weak charges compared to (electromagnetic) charges. We extract the point neutron radius Rn = 5.751 ± 0.175 (exp) ± 0.026(model) ± 0.005(strange) fm, from RW. Here there is only a very small error (strange) from possible strange quark contributions. We find Rn to be slightly smaller than RW because of the nucleon's size. As a result, we find a neutron skin thickness of Rn-Rp = 0.302 ± 0.175 (exp) ± 0.026 (model) ± 0.005 (strange) fm, where Rp is the point proton radius.« less

  11. Early Head Start: Factors Associated with Caregiver Knowledge of Child Development, Parenting Behavior, and Parenting Stress

    ERIC Educational Resources Information Center

    Belcher, Harolyn M. E.; Watkins, Katara; Johnson, Elizabeth; Ialongo, Nicholas

    2007-01-01

    This study investigates the role of socioeconomic status, parental mental health, and knowledge of child development on parenting styles and perceived parenting stress in caregivers of children, ages 3 months to 3 years, enrolled in Early Head Start (EHS). Caregivers of EHS students were interviewed using the Knowledge of Infant Development…

  12. Factors affecting access to head and neck cancer care after a natural disaster: a post-Hurricane Katrina survey.

    PubMed

    Loehn, Bridget; Pou, Anna M; Nuss, Daniel W; Tenney, Justin; McWhorter, Andrew; DiLeo, Michael; Kakade, Anagha C; Walvekar, Rohan R

    2011-01-01

    Our aim was to survey the factors affecting access to cancer care in patients with head and neck cancer after Hurricane Katrina. In this cross-sectional survey, 207 patients with head and neck cancer were identified post-Hurricane Katrina, but only 83 patients completed the questionnaires and were analyzed. Clinical, demographic, and socioeconomic data were recorded. Chi-square test and t test were used for comparisons. Patients who felt that there was a lack of access to cancer care would have sought treatment earlier had they had better access to cancer care (chi-square[1] = 32; p < .0001). Patients who felt that there was a lack of access to cancer care also had difficulty receiving treatment (chi-square[1] = 48; p < .0001). Availability of transportation affected access to cancer care in patients with early-stage cancers (chi-square[1] = 4; p < .035). In the postdisaster environment, patients who felt the lack of access to cancer care post-Hurricane Katrina would have sought treatment earlier with better access to cancer care. These patients also reported difficulty obtaining cancer treatment. Availability of transportation affected access to cancer care in patients with early-stage cancers. Clinical, demographic, and socioeconomic factors did not influence access to cancer care. © 2010 Wiley Periodicals, Inc. Head Neck, 2011.

  13. [Predict factors associated with malnutrition from patient generated subjective global assessment (PG-SGA) in head and neck cancer patients].

    PubMed

    Arribas, L; Hurtós, L; Milà, R; Fort, E; Peiró, I

    2013-01-01

    Patient Generated Subjective Global Assessment (PG-SGA) is a validated tool for nutrition evaluation in patients with cancer. The aim of our study was to estimate the prevalence of malnutrition in head and neck cancer patients at diagnosis and evaluate the independent prognostic factors for malnutrition from PG-SGA. All outpatients attending at the Head and Neck Cancer Multidisciplinary Meeting for primary diagnosis, staging and treatment were evaluated by an oncology dietitian using the patient generated subjective global assessment (PG-SGA). Patients with recurrences or secondary tumours will be excluded. 64 patients were evaluated (55 men and 9 women) with an average age of 63 years and body mass index (BMI) of 25.3 kg/m(2) (SD ± 5.18). After the nutritional assessment we observed that 43.8% of patients were malnourished or at risk of malnutrition. The most frequent symptom at diagnosis was dysphagia (48.4%) and anorexia (26.6%). From PG-SGA, the main prognostic factors (p<0,001) were the percentage of weight loss, serum albumin levels, BMI and the presence of dysphagia or/and anorexia prior diagnosis. Parameters as BMI, weight loss and low albumin levels at the time of diagnosis in head and neck cancer patients are independent predictors for malnutrition as well as the presence of anorexia or dysphagia.reaffirms the need for sustainability of interventions over time. Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

  14. Factors influencing in vitro respiratory burst assays with head kidney leucocytes from rainbow trout, Oncorhynchus mykiss (Walbaum).

    PubMed

    Chettri, J K; Holten-Andersen, L; Buchmann, K

    2010-07-01

    Abstract Head kidney leucocytes are central elements in a number of in vivo and in vitro assays elucidating innate and adaptive immune mechanisms in teleosts following stimulation with various antigens. These systems are sensitive to several factors affecting the outcome of the assays. The present work describes the importance of temperature, cell concentration, exposure time and immune-modulatory molecules on the respiratory burst activity (RBA) of rainbow trout head kidney leucocytes in vitro. Some variation in RBA was observed among individual fish. However, use of cells pooled from four individuals produced satisfactory results following exposure to phorbol 12-myristate 13-acetate, zymosan and beta-glucan. Temperature was shown to have a significant effect on production of reactive radicals as illustrated by a high activity in cells maintained at 15-20 degrees C and a reduced activity at temperature extremes (1, 4 and 30 degrees C). Highest activity was found at a cell concentration of 1 x 10(7) cells mL(-1). Reactivity showed a clear decline when cells were exposed for more than 4 h. Moreover, incubation of cells with inhibitory substances viz., DiMePE2, cortisol and superoxide dismutase decreased the RBA. It is concluded that several biotic and abiotic factors should be taken into account when conducting RBA assays with head kidney leucocytes for elucidation of rainbow trout immune responses.

  15. Head-to-head comparison of serial soluble ST2, growth differentiation factor-15, and highly-sensitive troponin T measurements in patients with chronic heart failure.

    PubMed

    Gaggin, Hanna K; Szymonifka, Jackie; Bhardwaj, Anju; Belcher, Arianna; De Berardinis, Benedetta; Motiwala, Shweta; Wang, Thomas J; Januzzi, James L

    2014-02-01

    This analysis aimed to perform a head-to-head comparison of 3 of the promising biomarkers of cardiovascular (CV) outcomes in heart failure (HF)-soluble ST2 (sST2), growth differentiation factor (GDF)-15, and highly-sensitive troponin T (hsTnT)-and to evaluate the role of serial measurement of these biomarkers in patients with chronic HF. sST2, GDF-15, and hsTnT are strongly associated with CV outcomes in HF. This post-hoc analysis used data from a study in which 151 patients with chronic HF due to left ventricular systolic dysfunction were followed up over 10 months. At each visit, N-terminal pro-B-type natriuretic peptide (NT-proBNP), sST2, GDF-15, and hsTnT were measured and any major CV events were recorded. Baseline values of all 3 novel biomarkers independently predicted total CV events even after adjusting for clinical and biochemical characteristics, including NT-proBNP, with the best model including all 3 biomarkers (p < 0.001). Adding serial measurement to the base model appeared to improve the model's predictive ability (with sST2 showing the most promise), but it is not clear whether this addition is a unique contribution. However, when time-dependent factors were included, only sST2 serial measurement independently added to the risk model (odds ratio: 3.64; 95% confidence interval: 1.37 to 9.67; p = 0.009) and predicted reverse myocardial remodeling (odds ratio: 1.22; 95% confidence interval: 1.04 to 1.43; p = 0.01). In patients with chronic HF, baseline measurement of novel biomarkers added independent prognostic information to clinical variables and NT-proBNP. Only serial measurement of sST2 appeared to add prognostic information to baseline concentrations and predicted change in left ventricular function. (Use of NT-proBNP Testing to Guide Heart Failure Therapy in the Outpatient Setting (PROTECT)]; NCT00351390). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  16. Stable Binding of the Conserved Transcription Factor Grainy Head to its Target Genes Throughout Drosophila melanogaster Development.

    PubMed

    Nevil, Markus; Bondra, Eliana R; Schulz, Katharine N; Kaplan, Tommy; Harrison, Melissa M

    2017-02-01

    It has been suggested that transcription factor binding is temporally dynamic, and that changes in binding determine transcriptional output. Nonetheless, this model is based on relatively few examples in which transcription factor binding has been assayed at multiple developmental stages. The essential transcription factor Grainy head (Grh) is conserved from fungi to humans, and controls epithelial development and barrier formation in numerous tissues. Drosophila melanogaster, which possess a single grainy head (grh) gene, provide an excellent system to study this conserved factor. To determine whether temporally distinct binding events allow Grh to control cell fate specification in different tissue types, we used a combination of ChIP-seq and RNA-seq to elucidate the gene regulatory network controlled by Grh during four stages of embryonic development (spanning stages 5-17) and in larval tissue. Contrary to expectations, we discovered that Grh remains bound to at least 1146 genomic loci over days of development. In contrast to this stable DNA occupancy, the subset of genes whose expression is regulated by Grh varies. Grh transitions from functioning primarily as a transcriptional repressor early in development to functioning predominantly as an activator later. Our data reveal that Grh binds to target genes well before the Grh-dependent transcriptional program commences, suggesting it sets the stage for subsequent recruitment of additional factors that execute stage-specific Grh functions.

  17. A descriptive review of the factors contributing to nutritional compromise in patients with head and neck cancer.

    PubMed

    Chasen, Martin R; Bhargava, Ravi

    2009-11-01

    Malnutrition has been known to be associated with adverse outcomes in cancer patients. Patients who have been and/or are being treated for head and neck cancer have a compromised nutritional status. Nutritional deficits have a significant impact on mortality, morbidity, and quality of life. The wasting in cancer cachexia involves loss of muscle and fat and reflects a catabolic metabolism induced by an abnormal host response to tumor presence and/or tumor factors. Disturbances of various physiological functions like taste, smell, dysphagia, xerostomia apart from cachexia can contribute to long-term nutritional complications and outcome. Improved management of patients in posttreatment for head and neck cancer may require a multimodal approach by a multidisciplinary team and is best commenced earlier in the trajectory of the disease.

  18. Evaluating Elastic Network Models of Crystalline Biological Molecules with Temperature Factors, Correlated Motions, and Diffuse X-Ray Scattering

    PubMed Central

    Riccardi, Demian; Cui, Qiang; Phillips, George N.

    2010-01-01

    In this study, the variance-covariance matrix of protein motions is used to compare several elastic network models within the theoretical framework of x-ray scattering from crystals. A set of 33 ultra-high resolution structures is used to characterize the average scaling behavior of the vibrational density of states and make comparisons between experimental and theoretical temperature factors. Detailed investigations of the vibrational density of states, correlations, and predicted diffuse x-ray scatter are carried out for crystalline Staphylococcal nuclease; correlations and diffuse x-ray scatter are also compared to predictions from the translation, libration, screw model and a liquid-like dynamics model. We show that elastic network models developed to best predict temperature factors without regard for the crystal environment have relatively strong long-range interactions that yield very short-ranged atom-atom correlations. Further, we find that the low-frequency modes dominate the variance-covariance matrix only for those models with a physically reasonable vibrational density of states, and the fraction of modes required to converge the correlations is higher than that typically used for elastic network model studies. The practical implications are explored using computed diffuse x-ray scatter, which can be measured experimentally. PMID:20959103

  19. Factors associated with long-term speech and swallowing outcomes after chemoradiotherapy for locoregionally advanced head and neck cancer.

    PubMed

    Mouw, Kent W; Haraf, Daniel J; Stenson, Kerstin M; Cohen, Ezra E; Xi, Xi; Witt, Mary Ellyn; List, Marcy; Blair, Elizabeth A; Vokes, Everett E; Salama, Joseph K

    2010-12-01

    to identify factors that influence patient-centered measures of speech and swallowing function after successful use of chemoradiotherapy to treat cancers of the head and neck. patients previously enrolled in a phase 2 trial using induction chemotherapy consisting of carboplatin and paclitaxel followed by chemoradiotherapy with paclitaxel, fluorouracil, hydroxyurea, and 1 of 3 radiation dose levels were assigned speaking and swallowing scores at follow-up ranging from 1 to 4, with 1 representing normal speech or swallowing and 4 representing significant sustained deficits. one hundred eighty-four patients with locoregionally advanced head and neck cancer. speech and swallowing function after chemoradiotherapy. of the 222 patients originally enrolled in the trial, 184 were alive and free of locoregional recurrence at the outset of this study. Of these eligible patients, 163 (88.6%) were assigned a speaking score of 1 through 4 at an average of 34.8 (range, 1.5-76.4) months after completion of treatment, whereas 166 patients (90.2%) were assigned a swallowing score of 1 through 4 at an average of 34.5 (range, 1.0-76.4) months after completion of treatment. Most patients (84.7% with speaking scores and 63.3% with swallowing scores) had no residual deficit and were assigned scores of 1. Factors that were associated with worse speaking outcomes included female sex, smoking history, hypopharyngeal or laryngeal primary sites, and poor response to induction chemotherapy; factors associated with worse swallowing outcomes included advanced patient age, poor performance status, primary site, and neck dissection. among patients successfully treated for locoregionally advanced cancers of the head and neck, several factors correlate with speaking and swallowing outcomes. Because advances in therapy have led to improved survival in these patients, understanding and controlling adverse effects of treatment should continue to be an active area of investigation.

  20. Evaluation of calculation methods of collimator scatter factors in a linear accelerator equipped with MLC instead of lower collimators.

    PubMed

    Kojima, Tomo; Sasaki, Koji

    2009-09-20

    In the monitor unit verification for high-energy radiation therapy, we evaluated methods of calculation of collimator scatter factors (S(c)) in a linear accelerator equipped with MLC instead of lower collimators. Routinely,S(c) is calculated from rectangular fields shaped by upper and lower jaws in the linear accelerator. However, this calculation method should not be used for the linear accelerator equipped with MLC instead of lower collimators. Consequently, we used a backprojected field at the flattening filter plane projected by calculation point's eye view on each MLC. We then attempted to deviseS(c) by using Clarkson's integration for these backprojected irregular fields. This method makes it possible to calculate collimator scatter factors in error of less than +/-0.3% in all of sixteen measured irregular fields.

  1. Mouse Y-Encoded Transcription Factor Zfy2 Is Essential for Sperm Head Remodelling and Sperm Tail Development

    PubMed Central

    Vernet, Nadege; Mahadevaiah, Shantha K.; Decarpentrie, Fanny; Longepied, Guy; de Rooij, Dirk G.; Burgoyne, Paul S.; Mitchell, Michael J.

    2016-01-01

    A previous study indicated that genetic information encoded on the mouse Y chromosome short arm (Yp) is required for efficient completion of the second meiotic division (that generates haploid round spermatids), restructuring of the sperm head, and development of the sperm tail. Using mouse models lacking a Y chromosome but with varying Yp gene complements provided by Yp chromosomal derivatives or transgenes, we recently identified the Y-encoded zinc finger transcription factors Zfy1 and Zfy2 as the Yp genes promoting the second meiotic division. Using the same mouse models we here show that Zfy2 (but not Zfy1) contributes to the restructuring of the sperm head and is required for the development of the sperm tail. The preferential involvement of Zfy2 is consistent with the presence of an additional strong spermatid-specific promotor that has been acquired by this gene. This is further supported by the fact that promotion of sperm morphogenesis is also seen in one of the two markedly Yp gene deficient models in which a Yp deletion has created a Zfy2/1 fusion gene that is driven by the strong Zfy2 spermatid-specific promotor, but encodes a protein almost identical to that encoded by Zfy1. Our results point to there being further genetic information on Yp that also has a role in restructuring the sperm head. PMID:26765744

  2. Seven years of aerosol scattering hygroscopic growth measurements from SGP: Factors influencing water uptake

    NASA Astrophysics Data System (ADS)

    Jefferson, A.; Hageman, D.; Morrow, H.; Mei, F.; Watson, T.

    2017-09-01

    Long-term measurements of changes in the aerosol scattering coefficient hygroscopic growth at the U.S. Department of Energy Southern Great Plains site provide information on the seasonal as well as size and chemical dependence of aerosol water uptake. Annual average sub-10 μm fRH values (the ratio of aerosol scattering at 85%/40% relative humidity (RH)) were 1.78 and 1.99 for the gamma and kappa fit algorithms, respectively. The study found higher growth rates in the winter and spring seasons that correlated with a high aerosol nitrate mass fraction. fRH exhibited strong, but differing, correlations with the scattering Ångström exponent and backscatter fraction, two optical size-dependent parameters. The aerosol organic mass fraction had a strong influence on fRH. Increases in the organic mass fraction and absorption Ångström exponent coincided with a decrease in fRH. Similarly, fRH declined with decreases in the aerosol single scatter albedo. Uncertainty analysis of the fit algorithms revealed high uncertainty at low scattering coefficients and increased uncertainty at high RH and fit parameters values.

  3. Factors Associated With Long-Term Dysphagia After Definitive Radiotherapy for Locally Advanced Head-and-Neck Cancer

    SciTech Connect

    Caudell, Jimmy J.; Schaner, Philip E.; Meredith, Ruby F.; Locher, Julie L.; Nabell, Lisle M.; Carroll, William R.; Magnuson, J. Scott; Spencer, Sharon A.; Bonner, James A.

    2009-02-01

    Purpose: The use of altered fractionation radiotherapy (RT) regimens, as well as concomitant chemotherapy and RT, to intensify therapy for locally advanced head-and-neck cancer can lead to increased rates of long-term dysphagia. Methods and Materials: We identified 122 patients who had undergone definitive RT for locally advanced head-and-neck cancer, after excluding those who had been treated for a second or recurrent head-and-neck primary, had Stage I-II disease, developed locoregional recurrence, had <12 months of follow-up, or had undergone postoperative RT. The patient, tumor, and treatment factors were correlated with a composite of 3 objective endpoints as a surrogate for severe long-term dysphagia: percutaneous endoscopic gastrostomy tube dependence at the last follow-up visit; aspiration on a modified barium swallow study or a clinical diagnosis of aspiration pneumonia; or the presence of a pharyngoesophageal stricture. Results: A composite dysphagia outcome occurred in 38.5% of patients. On univariate analysis, the primary site (p = 0.01), use of concurrent chemotherapy (p = 0.01), RT schedule (p = 0.02), and increasing age (p = 0.04) were significantly associated with development of composite long-term dysphagia. The use of concurrent chemotherapy (p = 0.01), primary site (p = 0.02), and increasing age (p = 0.02) remained significant on multivariate analysis. Conclusion: The addition of concurrent chemotherapy to RT for locally advanced head-and-neck cancer resulted in increased long-term dysphagia. Early intervention using swallowing exercises, avoidance of nothing-by-mouth periods, and the use of intensity-modulated RT to reduce the dose to the uninvolved swallowing structures should be explored further in populations at greater risk of long-term dysphagia.

  4. High enhancement factor of Au nano triangular prism structure for surface enhanced coherent anti-Stokes Raman scattering

    NASA Astrophysics Data System (ADS)

    Zhang, Zuyin; Song, Guofeng

    2017-02-01

    Coherent anti-Stokes Raman scattering spectroscopy (CARS) is a well-known detecting tool in biosensing and nonlinear spectroscopy. It can provide a non-invasive alternative without the need for exogenous labels, while the enhancement factor for surface plasmon resonances (SPR) are extensively used to increase the local field close to the oscillators and which can obtain high enhancement. In this work, we investigate the enhancement factor of our structure for surface-enhanced coherent anti-Stokes Raman scattering. The absorption spectrum of the structure has been studied, a wide range of absorption has been realized. The enhancement can be as high as 10{16} over standard CARS. Our design is very useful for improving the enhancement factor of surface-enhanced coherent anti-Stokes Raman scattering. Project supported by the National Key Research Program of China (No. 2011ZX01015-001) and the National Basic Research Program of China (Nos. 2011CBA00608, 2012CB619203, 2015CB351902, 2015CB932402).

  5. [Mandibular osteoradionecrosis (ORN) as a side effect of head and neck cancer treatment: Factors that induce it].

    PubMed

    Gallegos-Hernández, José Francisco; Reyes-Vivanco, Alejandro; Arias-Ceballos, Héctor; Minauro-Muñoz, Gerardo Gabriel; Ortiz-Maldonado, Alma Lilia; García-Ruiz, Daniel Israel; Hernández-Sanjuán, Martín

    Osteoradionecrosis of the mandible is a relatively common complication in patients with head and neck cancer undergoing radiotherapy or concomitant chemoradiotherapy, characterized by exposure of the mandibular bone either in the mouth or in the facial skin, with no improvement with conservative treatment for six months. The risk factors are radiotherapy in head and neck region, lack of dental prophylaxis before treatment and dental extraction. Retrospective observational study analyzing incidence and etiologic factors of osteoradionecrosis in 250 patients undergoing radiotherapy or combined treatment of cervicofacial area between 2002 and 2010. 25 patients were included; the horizontal branch was the most affected area, followed by the anterior arch. Associated factors were: stage (T4a and T4b), tumor location (oral cavity), dental extraction pre or post-radiotherapy, and radiotherapy time (pre-or postoperative); 72% had association with tooth extraction. Only five patients had control with conservative measures, and 20 required some type of mandibulectomy, only three of them were candidates for reconstruction with fibular free flap; none received treatment in a hyperbaric chamber. The data suggest that osteoradionecrosis has a multifactorial origin, and prevention is the best alternative and includes pretreatment dental prophylaxis to avoid tooth extractions and close monitoring and surveillance in order to identify early osteoradionecrosis. Most patients require mandible resection as definitive treatment.

  6. [Analysis of Factors Influencing the Development of Hypomagnesemia in Patients Receiving Cetuximab Therapy for Head and Neck Cancer].

    PubMed

    Inose, Ryo; Takahashi, Katsuyuki; Nishikawa, Takeshi; Nagayama, Katsuya

    2015-01-01

    Cetuximab was approved in Japan as the only clinically available molecular targeted drug for the treatment of head and neck cancer. Hypomagnesemia associated with cetuximab is considered one of the most serious adverse events. However, the factors influencing the development of hypomagnesemia are not clear, although the drug was previously approved for the treatment of patients with colorectal cancer. Thus, we studied the factors involved in the development of hypomagnesemia in patients receiving cetuximab therapy for head and neck cancer. Patients' background data and laboratory values before starting cetuximab therapy did not affect the development of hypomagnesemia. Among patients who had never been treated with cisplatin (NT group), 36.4% developed hypomagnesemia. In contrast, all patients who had previously been treated with cisplatin (T group) developed hypomagnesemia (p=0.034). Magnesium is reabsorbed by transient receptor potential subfamily melastatin 6 (TRPM6) in the distal convoluted tubule. The expression level of TRPM6 is controlled by the epidermal growth factor (EGF) pathway. Cetuximab is an EGF receptor inhibitor and reduces the expression of TRPM6. Additionally, recent studies have shown that the expression of TRPM6 is reduced by cisplatin. Therefore, we considered that the serum magnesium level was cumulatively reduced by cetuximab and cisplatin. In conclusion, the T group was more likely to develop hypomagnesemia than the NT group, and therefore the serum magnesium level in the T group requires careful monitoring so that magnesium supplementation can be provided to patients when the level decreases.

  7. Use of novel fibre-coupled radioluminescence and RADPOS dosimetry systems for total scatter factor measurements in small fields.

    PubMed

    Ploquin, N; Kertzscher, G; Vandervoort, E; Cygler, J E; Andersen, C E; Francescon, P

    2015-01-07

    A dosimetry system based on Al2O3:C radioluminescence (RL), and RADPOS, a novel 4D dosimetry system using microMOSFETs, were used to measure total scatter factors, (S(c,p))(f(clin))(det), for the CyberKnife robotic radiosugery system. New Monte Carlo calculated correction factors are presented and applied for the RL detector response for the 5, 7.5 and 10 mm collimators in order to correct for the detector geometry and increased photoelectric cross section of Al2O3:C relative to water. For comparison, measurements were also carried out using a micro MOSFET, PTW60012 diode and GAFCHROMIC(®) film (EBT and EBT2). Uncorrected (S(c,p))(f(clin))(det) were obtained by taking the ratio of the detector response for each collimator to that for the 60 mm diameter reference field. Published Monte Carlo calculated correction factors were applied to the RADPOS, microMOSFET and diode detector measurements to yield corrected field factors, Ω(f(clin),f(msr))(Q(clin),Q(msr)), following the terminology of a recent formalism introduced for small and composite field relative dosimetry. With corrections, the RL measured Ω(f(clin),f(msr))(Q(clin),Q(msr)) were 0.656  ±  0.002, 0.815  ±  0.002 and 0.865  ±  0.003 for the 5, 7.5 and 10 mm collimators, respectively. This was in good agreement with RADPOS corrected field factors of 0.650  ±  0.010, 0.816  ±  0.024 and 0.867  ±  0.010 for the 5, 7.5 and 10 mm collimators, respectively. Both RL and RADPOS total scatter factors agreed within approximately two standard deviations of the GAFCHROMIC film values (average of EBT and EBT2) of 0.640  ±  0.006, 0.806  ±  0.007 and 0.859  ±  0.09. Corrected total scatter factors for all dosimetry systems agreed within one standard deviation for collimator sizes 10-60 mm. Our study suggests that the microMOSFET/RADPOS and optical fibre-coupled RL dosimetry system are well suited for total scatter factor measurements over the entire range of field

  8. Use of novel fibre-coupled radioluminescence and RADPOS dosimetry systems for total scatter factor measurements in small fields

    NASA Astrophysics Data System (ADS)

    Ploquin, N.; Kertzscher, G.; Vandervoort, E.; Cygler, J. E.; Andersen, C. E.; Francescon, P.

    2015-01-01

    A dosimetry system based on Al2O3:C radioluminescence (RL), and RADPOS, a novel 4D dosimetry system using microMOSFETs, were used to measure total scatter factors, ≤ft({{S}c,p}\\right)\\text{det}{{f\\text{clin}}}, for the CyberKnife robotic radiosugery system. New Monte Carlo calculated correction factors are presented and applied for the RL detector response for the 5, 7.5 and 10 mm collimators in order to correct for the detector geometry and increased photoelectric cross section of Al2O3:C relative to water. For comparison, measurements were also carried out using a micro MOSFET, PTW60012 diode and GAFCHROMIC® film (EBT and EBT2). Uncorrected ≤ft({{S}c,p}\\right)\\text{det}{{f\\text{clin}}}, were obtained by taking the ratio of the detector response for each collimator to that for the 60 mm diameter reference field. Published Monte Carlo calculated correction factors were applied to the RADPOS, microMOSFET and diode detector measurements to yield corrected field factors, Ω {{Q\\text{clin}},{{Q}\\text{msr}}}{{f\\text{clin}},{{f}\\text{msr}}}, following the terminology of a recent formalism introduced for small and composite field relative dosimetry. With corrections, the RL measured Ω {{Q\\text{clin}},{{Q}\\text{msr}}}{{f\\text{clin}},{{f}\\text{msr}}}, were 0.656  ±  0.002, 0.815  ±  0.002 and 0.865  ±  0.003 for the 5, 7.5 and 10 mm collimators, respectively. This was in good agreement with RADPOS corrected field factors of 0.650  ±  0.010, 0.816  ±  0.024 and 0.867  ±  0.010 for the 5, 7.5 and 10 mm collimators, respectively. Both RL and RADPOS total scatter factors agreed within approximately two standard deviations of the GAFCHROMIC film values (average of EBT and EBT2) of 0.640  ±  0.006, 0.806  ±  0.007 and 0.859  ±  0.09. Corrected total scatter factors for all dosimetry systems agreed within one standard deviation for collimator sizes 10-60 mm. Our study suggests that the micro

  9. IMC-C225, an anti-epidermal growth factor receptor monoclonal antibody for treatment of head and neck cancer.

    PubMed

    Herbst, Roy S; Hong, Waun Ki

    2002-10-01

    Squamous cell carcinoma of the head and neck remains a clinical challenge because of the high rate of locoregional disease recurrence. The importance of the epidermal growth factor receptor (EGFR) in the development and progression of many solid tumors, including squamous cell carcinoma of the head and neck, is well understood; increased expression is associated with enhanced tumor invasiveness, resistance to chemotherapy, and a lower patient survival rate. Several approaches have been developed to achieve EGFR blockade as an anticancer treatment strategy, including the anti-EGFR monoclonal antibody IMC-C225, which competitively binds to the extracellular receptor site and prevents binding by the natural EGFR ligands EGF and transforming growth factor-alpha. Preclinical studies to evaluate IMC-225 in human cancer cell lines in vitro and human tumor xenografts in vivo have shown its potent antitumor activity. Clinical efficacy of IMC-C225 appears to involve multiple mechanisms, including inhibition of cell cycle progression, induction of apoptosis, inhibition of angiogenesis, inhibition of metastasis, and enhancement of the response to chemotherapy and radiation therapy. Phase I studies of IMC-C225 combined with chemotherapy or radiation showed promising response rates in patients with recurrent or refractory squamous cell carcinoma of the head and neck. Phase II and III trials to examine the efficacy and safety of these combinations are currently underway. To date, IMC-C225 has been well tolerated, with skin rashes and allergic reactions being the most clinically important adverse events reported. IMC-C225 displays dose-dependent elimination characteristics and a half-life of approximately 7 days. Current recommendations for dosing include a 400 mg/m(2) loading dose, followed by weekly infusions at 250 mg/m(2). Copyright 2002, Elsevier Science (USA). All rights reserved.

  10. ππ scattering, pion form factors and chiral perturbation theory

    NASA Astrophysics Data System (ADS)

    Colangelo, Gilberto

    2005-04-01

    I discuss recent progress in our understanding of the ππ scattering amplitude at low energy thanks to the combined use of chiral perturbation theory and dispersion relations. I also comment on the criticism raised by Peláez and Ynduráin on this work.

  11. Impact of p16 status on pro- and anti-angiogenesis factors in head and neck cancers

    PubMed Central

    Baruah, P; Lee, M; Wilson, P O G; Odutoye, T; Williamson, P; Hyde, N; Kaski, J C; Dumitriu, I E

    2015-01-01

    Background: Head and neck cancers (HNC) are aggressive tumours. Overexpression of p16 in HNC correlates with human papilloma virus (HPV)-associated HNC that carry a better prognosis than HPV-negative tumours. Angiogenesis is an important factor in tumour progression. Our aim was to dissect the impact of p16 expression on angiogenesis factors in HNC. Methods: Eighteen newly diagnosed HNC patients and controls were analysed. Eleven pro- and anti-angiogenesis factors were quantified using multiplex ELISA in HNC patients and controls. Angiogenesis factors were analysed in tumour tissue using immunohistochemistry. Results: Circulating levels of endostatin (anti-angiogenesis factor) were higher in the HNC group compared with healthy donors. Interestingly, the pro-angiogenesis factors angiopoietin-1 and vascular endothelial growth factor (VEGF) were significantly higher in patients with p16-negative compared with p16-positive HNC. Moreover, the major source of VEGF in p16-positive HNC tissue was tumour stromal cells. In contrast, both tumour cells and stromal cells expressed VEGF in p16-negative tissue. Conclusions: We show that p16-negative tumours associate with increased circulating levels of pro-angiogenic VEGF and angiopoietin-1. Tissue expression of VEGF differs between p16-positive and p16-negative tumours. These findings may explain differences in the biological behaviour of p16-positive and p16-negative HNC. Better understanding of mechanisms by which the p16 status influences tumour angiogenesis may guide the development of targeted therapies. PMID:26171937

  12. Risk factors for thirty-day readmission following flap reconstruction of oncologic defects of the head and neck.

    PubMed

    Osborn, Heather A; Rathi, Vinay K; Tjoa, Tjoson; Goyal, Neerav; Yarlagadda, Bharat B; Rich, Debbie L; Emerick, Kevin S; Lin, Derrick T; Deschler, Daniel G; Durand, Marlene L

    2017-08-29

    Unplanned 30-day readmission rate following hospital discharge is an important metric of healthcare quality. This study sought to characterize the rate, risk factors, and common causes of readmission in head and neck cancer patients following free or pedicled flap reconstruction. Retrospective cohort study. Charts were reviewed of all patients who underwent free or pedicled flap reconstruction following resection of head and neck cancer at the Massachusetts Eye and Ear Infirmary 2009 to 2014. Readmission risk factors were evaluated by univariate and multivariate analysis. Of 682 patients with free (76%) or pedicled flap reconstruction, 135 patients (19.8%) were readmitted. Factors not associated with readmission included age, gender, American Society of Anesthesiologists status, operative time, prior radiation therapy, primary cancer site, and free (vs. pedicled) flap type. Significant readmission risk factors included surgical site infections (SSI) (45.2% vs. 9.9%), use of hardware (18.5% vs. 11.3%), and clean-contaminated or contaminated surgery (15.2% vs. clean 8.2%). Surgical site infections (P < 0.001) and use of hardware (P = 0.03) remained predictive of readmission on multiple regression analysis. Primary reasons for readmission included wound complications (61.5%) and supportive care (15.6%). The median time to readmission was 8 days, and 41% of readmissions occurred within 1 week. Seventy percent of readmissions occurred within 2 weeks, including 77% of readmissions for SSIs and 86% for supportive care. Readmissions occurred in nearly one-fifth of patients following flap surgery. SSIs and use of hardware were risk factors, whereas wound complications were the most common cause of readmission. 4. Laryngoscope, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  13. Mania following head injury.

    PubMed

    Yatham, L N; Benbow, J C; Jeffers, A M

    1988-03-01

    A case of mania following head injury in an individual with a genetic predisposition to schizophrenia is reported. It is argued that the head injury is probably causative in his case and suggested that head injury should be considered as one of the aetiological factors in secondary mania.

  14. Fast method of retrieving the asymmetry factor and scattering albedo from the maximum time-resolved reflectance of participating media.

    PubMed

    Qi, Hong; Ren, Ya-Tao; Chen, Qin; Ruan, Li-Ming

    2015-06-01

    This research presents a parametric study of the time-resolved hemispherical reflectance of a semi-infinite plane-parallel slab of homogeneous, nonemitting, absorbing, and anisotropic scattering medium exposed to a collimated Gaussian pulse. The one-dimensional transient radiative transfer equation was solved by using the finite volume method. The internal reflection at the medium-air interface caused by the mismatch of the refractive indices was considered. In particular, this work focused on the maximum diffuse hemispherical reflectance. Three different optical regions were identified according to the dimensionless pulsewidth βctp. The correlation between the normalized maximum hemispherical reflectance and βctp was conformed to the Boltzmann function. The coefficients in the correlating functions of the match and mismatch refractive index cases were fitted as polynomial fitting functions of the single scattering albedo ω and Henyey-Greenstein asymmetric factor g. Thus, ω and g can be simultaneously reconstructed by the semi-empirical correlations without solving the forward model. In conclusion, the proposed method can potentially retrieve the asymmetry factor and single scattering albedo of participating media accurately and efficiently.

  15. Impact of Time Factors on Outcome in Patients with Head and Neck Cancer Treated with Definitive Radio(Chemo)Therapy.

    PubMed

    Dahlke, Sören; Steinmann, Diana; Christiansen, Hans; Durisin, Martin; Eckardt, Andre; Wegener, Gerd; Bremer, Michael; Meyer, Andreas

    2017-01-01

    To evaluate treatment-related factors such as overall treatment time (OTT) and radiation treatment time (RTT) in head-and-neck cancer. A total of 216 patients with locoregionally advanced inoperable head and neck cancer were treated with definitive radio(chemo)therapy. Mean follow-up was 37 months. Median time from diagnosis to start of radiotherapy (total waiting time) was 34 days, and comprised of referral waiting time and time for preparatory work. Median RTT was 40 days, and median OTT was 91 days. At 6, 12 and 24 months local recurrence-free survival (LRFS) was 75%, 65% and 60%; metastasis-free survival (MFS) was 84%, 77% and 70%; overall survival (OS) was 72%, 58% and 40%. Tumor stage, boost and chemotherapy were significant for OS, waiting time for preparatory work and RTT were significant for MFS, and referral waiting time and total radiotherapy dose for LRFS. RTT ≤40 days was a prognostic factor for better MFS. Prolonged waiting time had a converse effect for radiotherapy with better outcome on MFS and LRFS. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  16. Determination of 16O and 18O sensitivity factors and charge-exchange processes in low-energy ion scattering

    NASA Astrophysics Data System (ADS)

    Téllez, H.; Chater, R. J.; Fearn, S.; Symianakis, E.; Brongersma, H. H.; Kilner, J. A.

    2012-10-01

    Quantitative analysis in low-energy ion scattering (LEIS) requires an understanding of the charge-exchange processes to estimate the elemental sensitivity factors. In this work, the neutralization of He+ scattered by 18O-exchanged silica at energies between 0.6 and 7 keV was studied. The process is dominated by Auger neutralization for Ei < 0.8 keV. An additional mechanism starts above the reionization threshold. This collision-induced neutralization becomes the dominant mechanism for Ei > 2 keV. The ion fractions P+ were determined for Si and O using the characteristic velocity method to quantify the surface density. The 18O/16O sensitivity ratio indicates an 18% higher sensitivity for the heavier O isotope.

  17. Parity-Violating Electron Scattering from {sup 4}He and the Strange Electric Form Factor of the Nucleon

    SciTech Connect

    Aniol, Konrad; Armstrong, David; Averett, Todd; Benaoum, Hachemi; Bertin, Pierre; Burtin, Etienne; Cahoon, Jason; Cates, Gordon; Chang, C; Chao, Yu-Chiu; Chen, Jian-Ping; Choi, Seonho; Chudakov, Eugene; Craver, Brandon; Cusanno, Francesco; Decowski, Piotr; Deepa, Deepa; Ferdi, Catherine; Feuerbach, Robert; Finn, John; Frullani, Salvatore; Fuoti, Kirsten; Garibaldi, Franco; Gilman, Ronald; Glamazdin, Oleksandr; Gorbenko, V; Grames, Joseph; Hansknecht, John; Higinbotham, Douglas; Holmes, Richard; Holmstrom, Timothy; Humensky, Thomas; Ibrahim, Hassan; Jager, Cornelis De; Jiang, Xiaodong; Kaufman, Lisa; Kelleher, Aidan; Kolarkar, Ameya; Kowalski, Stanley; Kumar, Krishna; Lambert, Daniel; Laviolette, Peter; LeRose, John; Lhuillier, David; Liyanage, Nilanga; Margaziotis, Demetrius; Mazouz, Malek; McCormick, Kathy; Meekins, David; Meziani, Zein-Eddine; Michaels, Robert; Moffit, Bryan; Monaghan, Peter; Camacho, Carlos Munoz; Nanda, Sirish; Nelyubin, Vladimir; Neyret, Damien; Paschke, Kent; Poelker, Benard; Pomatsalyuk, Roman; Qiang, Yi; Reitz, Bodo; Roche, Julie; Saha, Arunava; Singh, Jaideep; Snyder, Ryan; Souder, Paul; Subedi, Ramesh; Suleiman, Riad; Sulkosky, Vincent; Tobias, William; Urciuoli, Guido; Vacheret, Antonin; Voutier, Eric; Wang, Kebin; Wilson, R; Wojtsekhowski, Bogdan; Zheng, Xiaochao

    2005-06-01

    We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from {sup 4}He at an average scattering angle {theta}{sub lab} = 5.7 degrees and a four-momentum transfer Q{sup 2} = 0.091 GeV{sup 2}. From these data, for the first time, the strange electric form factor of the nucleon G{sub E}{sup s} can be isolated. The measured asymmetry of A{sub PV} = 6.72 {+-} 0.84 (stat) {+-} 0.21 (syst) parts per million yields a value of G{sub E}{sup s} = -0.038 {+-} 0.042 (stat) {+-} 0.010 (syst), consistent with zero.

  18. Meson exchange effects in elastic ep scattering at loop level and the electromagnetic form factors of the proton

    NASA Astrophysics Data System (ADS)

    Chen, Hong-Yu; Zhou, Hai-Qing

    2014-10-01

    A new form of two-photon exchange (TPE) effect is studied to explain the discrepancy between unpolarized and polarized experimental data in elastic ep scattering. The mechanism is based on a simple idea that apart from the usual TPE effects from box and crossed-box diagrams, the mesons may also be exchanged in elastic ep scattering by two-photon coupling at loop level. The detailed study shows such contributions to reduced unpolarized cross section (σun) and polarized observables (Pt,Pl) at fixed Q2 are only dependent on proton's electromagnetic form factors GE ,M and a new unknown universal parameter g. After combining this contribution with the usual TPE contributions from box and crossed-box diagrams, the ratio μpGE/GM extracted from the recent precise unpolarized and polarized experimental data can be described consistently.

  19. Parity-Violating Electron Scattering from {sup 4}He and the Strange Electric Form Factor of the Nucleon

    SciTech Connect

    Aniol, K.A.; Margaziotis, D.J.; Armstrong, D.S.; Averett, T.; Finn, J.M.; Holmstrom, T.; Kelleher, A.; Moffit, B.; Sulkosky, V.; Benaoum, H.; Holmes, R.; Souder, P.A.; Bertin, P.Y.; Ferdi, C.

    2006-01-20

    We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from {sup 4}He at an average scattering angle <{theta}{sub lab}>=5.7 deg. and a four-momentum transfer Q{sup 2}=0.091 GeV{sup 2}. From these data, for the first time, the strange electric form factor of the nucleon G{sub E}{sup s} can be isolated. The measured asymmetry of A{sub PV}=(6.72{+-}0.84{sub (stat)}{+-}0.21{sub (syst)})x10{sup -6} yields a value of G{sub E}{sup s}=-0.038{+-}0.042{sub (stat)}{+-}0.010{sub (syst)}, consistent with zero.

  20. Heading and head injuries in soccer.

    PubMed

    Kirkendall, D T; Jordan, S E; Garrett, W E

    2001-01-01

    In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the

  1. Risk factors for wound complications in head and neck reconstruction: 773 free jejunal reconstruction procedures after total pharyngolaryngoesophagectomy.

    PubMed

    Sugiyama, Narushi; Takao, Soshi; Suzuki, Etsuji; Kimata, Yoshihiro

    2017-10-01

    Most studies that examined risk factors for wound complications after head and neck reconstruction analyzed various complications collectively. Moreover, they included a wide variety of resection areas and reconstruction materials. To overcome these limitations, both the resection area and reconstruction method were constrained in the present study. Patients who underwent free jejunal graft reconstruction after pharyngolaryngoesophagectomy for hypopharyngeal cancer were enrolled. The outcomes of interest were abscesses, fistulas, and cervical skin flap necrosis. Abscesses, fistulas, and cervical skin flap necrosis developed in 19.3%, 11.3%, and 8.2% of 773 patients, respectively. A significant relationship was found between use of an open drain and abscess formation and between a longer operation time and cervical skin flap necrosis. Our findings suggest that use of an open drain, cardiovascular disease, and a longer operation time are significant risk factors for abscess formation, fistula formation, and cervical skin flap necrosis, respectively. © 2017 Wiley Periodicals, Inc.

  2. Risk and Protective Factors for Adult and Child Hunger Among Low-Income Housed and Homeless Female-Headed Families

    PubMed Central

    Wehler, Cheryl; Weinreb, Linda F.; Huntington, Nicholas; Scott, Richard; Hosmer, David; Fletcher, Kenneth; Goldberg, Robert; Gundersen, Craig

    2004-01-01

    Objectives. We sought to identify factors associated with adult or child hunger. Methods. Low-income housed and homeless mothers were interviewed about socioeconomic, psychosocial, health, and food sufficiency information. Multinomial logistic regression produced models predicting adult or child hunger. Results. Predictors of adult hunger included mothers’ childhood sexual molestation and current parenting difficulties, or “hassles.” Risk factors for child hunger included mothers’ childhood sexual molestation, housing subsidies, brief local residence, having more or older children, and substandard housing. Conclusions. This study found that the odds of hunger, although affected by resource constraints in low-income female-headed families, were also worsened by mothers’ poor physical and mental health. Eliminating hunger thus may require broader interventions than food programs. PMID:14713707

  3. Risk and protective factors for adult and child hunger among low-income housed and homeless female-headed families.

    PubMed

    Wehler, Cheryl; Weinreb, Linda F; Huntington, Nicholas; Scott, Richard; Hosmer, David; Fletcher, Kenneth; Goldberg, Robert; Gundersen, Craig

    2004-01-01

    We sought to identify factors associated with adult or child hunger. Low-income housed and homeless mothers were interviewed about socioeconomic, psychosocial, health, and food sufficiency information. Multinomial logistic regression produced models predicting adult or child hunger. Predictors of adult hunger included mothers' childhood sexual molestation and current parenting difficulties, or "hassles." Risk factors for child hunger included mothers' childhood sexual molestation, housing subsidies, brief local residence, having more or older children, and substandard housing. This study found that the odds of hunger, although affected by resource constraints in low-income female-headed families, were also worsened by mothers' poor physical and mental health. Eliminating hunger thus may require broader interventions than food programs.

  4. Factors affecting breeding season survival of Red-Headed Woodpeckers in South Carolina.

    SciTech Connect

    Kilgo, John, C.; Vukovich, Mark

    2011-11-18

    Red-headed woodpecker (Melanerpes erythrocephalus) populations have declined in the United States and Canada over the past 40 years. However, few demographic studies have been published on the species and none have addressed adult survival. During 2006-2007, we estimated survival probabilities of 80 radio-tagged red-headed woodpeckers during the breeding season in mature loblolly pine (Pinus taeda) forests in South Carolina. We used known-fate models in Program MARK to estimate survival within and between years and to evaluate the effects of foliar cover (number of available cover patches), snag density treatment (high density vs. low density), and sex and age of woodpeckers. Weekly survival probabilities followed a quadratic time trend, being lowest during mid-summer, which coincided with the late nestling and fledgling period. Avian predation, particularly by Cooper's (Accipiter cooperii) and sharp-shinned hawks (A. striatus), accounted for 85% of all mortalities. Our best-supported model estimated an 18-week breeding season survival probability of 0.72 (95% CI = 0.54-0.85) and indicated that the number of cover patches interacted with sex of woodpeckers to affect survival; females with few available cover patches had a lower probability of survival than either males or females with more cover patches. At the median number of cover patches available (n = 6), breeding season survival of females was 0.82 (95% CI = 0.54-0.94) and of males was 0.60 (95% CI = 0.42-0.76). The number of cover patches available to woodpeckers appeared in all 3 of our top models predicting weekly survival, providing further evidence that woodpecker survival was positively associated with availability of cover. Woodpecker survival was not associated with snag density. Our results suggest that protection of {ge}0.7 cover patches per ha during vegetation control activities in mature pine forests will benefit survival of this Partners In Flight Watch List species.

  5. An exploration of factors predicting malnutrition in patients with advanced head and neck cancer.

    PubMed

    Silander, Ewa; Nyman, Jan; Hammerlid, Eva

    2013-10-01

    Malnutrition is common among head and neck cancer patients and negatively impacts on survival and quality of life. This study aimed to identify predictors of malnutrition at time of diagnosis in order to identify patients at risk and enable early nutritional support and prevent malnutrition. A total of 134 patients with advanced oral and pharyngeal cancer were included in the study. Weight, body mass index (BMI), fat free mass (FFM), dysphagia, and quality of life were measured at diagnosis and after 6 months. Two definitions for malnutrition were applied: >10% weight loss and BMI <20 after 6 months. Six months after diagnosis, 66% of the patients were malnourished as per the >10% weight loss definition, and 26% of the patients were malnourished as per the BMI < 20 weight loss definition. In multivariate analysis, low BMI followed by low FFM and dysphagia were the strongest predictors for malnutrition using BMI <20. Chemotherapy and high BMI at diagnosis were the strongest predictors of malnutrition using the 10% weight loss definition. For patients treated with chemotherapy, the risk for malnutrition was very high both for patients with normal BMI (67%) and for patients with BMI 30 (89%). Unintended weight loss more than 10% seems to be the most reasonable definition of malnutrition for identifying predictors of this in head and neck cancer patients. The weight loss correlated significantly to a loss of FFM. Treatment with chemotherapy was a strong predictor, as was a high BMI at time of diagnosis. This is an important finding since overweight patients might not be considered at high risk for developing malnutrition, and consequently nutritional support for them might be delayed. Copyright © 2013 The American Laryngological, Rhinological, and Otological Society, Inc.

  6. New relativistic S-matrix results for scattering -- beyond the usual anomalous factors/beyond impulse approximation

    SciTech Connect

    Pratt, R.H.; Bergstrom, P.M. Jr.; Kissel, L. |

    1993-08-01

    The relativistic second-order S-matrix elements for photon-atom scattering have been successfully calculated with numerical methods within the independent particle approximation (IPA). This permits an assessment of the validity of simpler approximate predictions which are commonly used and it offers the possibility of improved tabulations of theoretical predictions. A variety of unresolved issues remain, some associated with the relativistic theory, some with IPA. The systematic use of the second-order S-matrix in calculations of Rayleigh scattering from isolated atoms has led to significant progress in understanding this process and to a wide range of agreement with experiment. The energy and angular dependence of anomalous factors and the importance of relativistic, higher-multipole and bound-bound contributions in their calculation is better understood. However correlation effects must also be included to obtain predictions for the near-edge region, such extensions of the present S-matrix calculation have been discussed but few results are sofar available. Existing empirical approaches can be assessed in regard to their success in dealing with known IPA features. We have recently calculated the relativistic second-order S-matrix element for Compton scattering and have begun to try to understand this process in different regions. We can discuss when the more complete calculation confirms the standard Compton peak. In the softer part of the spectrum impulse approximation fails. There can be resonant Raman peaks, and in the soft-photon region the spectrum is infrared divergent, proportional to the photoeffect angular distribution. This means the traditional incoherent scattering factor is undefined in the absence of a low-energy detector efficiency cutoff.

  7. Radial Head Subluxation: Factors Associated with Its Recurrence and Radiographic Evaluation in a Tertiary Pediatric Emergency Department.

    PubMed

    Wong, Kei; Troncoso, Alex B; Calello, Diane P; Salo, David; Fiesseler, Fred

    2016-12-01

    Radial head subluxation (RHS) is a common complaint seen in the pediatric emergency department in children ages 6 months to 4 years. Classically, injury occurs due to axial traction on the arm, but this mechanism is not universal. Some patients will have recurrent RHS; some may undergo x-ray (XR) evaluation for alternative diagnosis. To determine factors associated with recurrences and radiographic evaluations in RHS. A retrospective study with inclusion criteria: under 10 years of age with discharge diagnosis "nursemaid," "radial head," or "subluxation." We examined factors associated with RHS recurrences, circumstances when radiographic evaluations performed, physician's training background (pediatric vs. general emergency medicine), mechanisms of injury, and demographic factors including age, gender, and arm involved. In 246 visits, median age was 27 months (interquartile range 16.1), with females comprising 55.7% (n = 137), and left-sided predominance (52%, n = 130). Mechanisms of injury were classified as "pull" (65.9%, n = 162), "non-pull" (15.9%, n = 39), and "unknown" (18.3%, n = 45). Eighteen patients with recurring RHS were more likely to be male (p = 0.008). In 61 visits where radiography was performed, patients were older (p = 0.03), with a higher frequency seen in non-pull and unknown mechanism (p = 0.0001). No significant difference was found in frequency of radiographs obtained in regard to physician training (p = 0.4660). RHS can result from a myriad of mechanisms. We found that recurrence was more likely in male patients. Factors associated with radiographic evaluation included atypical mechanism, older age, and unclear history, regardless of physician training background. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Electron g-factor for cubic Zn1-xCdxSe determined by spin-flip Raman scattering

    NASA Astrophysics Data System (ADS)

    Karimov, O. Z.; Wolverson, D.; Davies, J. J.; Stepanov, S. I.; Ruf, T.; Ivanov, S. V.; Sorokin, S. V.; O'donnell, C. B.; Prior, K. A.

    2000-12-01

    We present spin-flip Raman-scattering measurements of the g-factor for electrons bound at neutral donors in cubic Zn1-xCdxSe (0<=x<=1) grown by molecular-beam epitaxy. Excitation in resonance with the donor-bound exciton luminescence transition in the presence of a magnetic field produces Raman signals associated with transitions between the spin states of the bound electron. The dependence of the Raman shift of the signals on the magnetic field allows an accurate determination of the electron g-factor. For the particular case of cubic CdSe, the g-factor was measured to be +0.42+/-0.01. Five-band k.p perturbation theory was successfully used to reproduce the experimental dependence of the g-factor on Cd content, which can be approximated well by g(x)=1.16-0.56x-0.18x2.

  9. Inelastic x-ray scattering studies on dynamic structure factor of polymeric liquid Se under pressure

    SciTech Connect

    Inui, Masanori; Kajihara, Yukio; Kimura, Koji; Matsuda, Kazuhiro; Ohara, Koji; Tsutsui, Satoshi; Ishikawa, Daisuke

    2015-08-17

    Inelastic X-ray scattering measurements at 25 MPa using synchrotron radiation were carried out for semiconducting liquid Se at high temperatures up to 1673 K. The excitation energy of the acoustic mode disperses approximately 10-50 % faster than the ultrasonic sound velocity in the observed temperature range while the ultrasonic sound rapidly slows down with increasing temperature. We carried out X-ray scattering measurements and found that the average coordination number at 1673 K is 1.3, indicating that the high temperature liquid consists of short chain molecules. These results suggest that weakening of the interatomic interaction is correlated with breaking of polymeric chain molecules.

  10. Two-Photon Exchange in Elastic Electron-Proton Scattering: A QCD Factorization Approach

    SciTech Connect

    Kivel, Nikolai; Vanderhaeghen, Marc

    2009-08-28

    We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer Q{sup 2}. It is shown that the leading two-photon exchange amplitude behaves as 1/Q{sup 4}, and can be expressed in a model independent way in terms of the leading twist nucleon distribution amplitudes. Using several models for the nucleon distribution amplitudes, we provide estimates for existing data and for ongoing experiments.

  11. Dosimetric Factors Associated With Long-Term Dysphagia After Definitive Radiotherapy for Squamous Cell Carcinoma of the Head and Neck

    SciTech Connect

    Caudell, Jimmy J.; Schaner, Philip E.; Desmond, Renee A.; Meredith, Ruby F.; Spencer, Sharon A.; Bonner, James A.

    2010-02-01

    Purpose: Intensification of radiotherapy and chemotherapy for head-and-neck cancer may lead to increased rates of dysphagia. Dosimetric predictors of objective findings of long-term dysphagia were sought. Methods and Materials: From an institutional database, 83 patients were identified who underwent definitive intensity-modulated radiotherapy for squamous cell carcinoma of the head and neck, after exclusion of those who were treated for a second or recurrent head-and-neck primary lesion, had locoregional recurrence at any time, had less than 12 months of follow-up, or had postoperative radiotherapy. Dosimetric parameters were analyzed relative to three objective endpoints as a surrogate for severe long-term dysphagia: percutaneous endoscopic gastrostomy (PEG) tube dependence at 12 months, aspiration on modified barium swallow, or pharyngoesophageal stricture requiring dilation. Results: Mean dose greater than 41 Gy and volume receiving 60 Gy (V{sub 60}) greater than 24% to the larynx were significantly associated with PEG tube dependence and aspiration. V{sub 60} greater than 12% to the inferior pharyngeal constrictor was also significantly associated with increased PEG tube dependence and aspiration. V{sub 65} greater than 33% to the superior pharyngeal constrictor or greater than 75% to the middle pharyngeal constrictor was associated with pharyngoesophageal stricture requiring dilation. Conclusions: Doses to the larynx and pharyngeal constrictors predicted long-term swallowing complications, even when controlled for other clinical factors. The addition of these structures to intensity-modulated radiotherapy optimization may reduce the incidence of dysphagia, although cautious clinical validation is necessary.

  12. Clinical and biological factors affecting response to radiotherapy in patients with head and neck cancer: a review.

    PubMed

    Silva, P; Homer, J J; Slevin, N J; Musgrove, B T; Sloan, P; Price, P; West, C M L

    2007-10-01

    The main aim of this article was to review the clinical and biological factors that have been shown to influence the response of the head and neck squamous cell carcinoma (HNSCC) to primary radiotherapy and briefly discuss how some of these factors could be exploited to improve outcome. Medline based search covering 1982-2006 to identify the HNSCC literature where the effect of clinical and biological factors on locoregional control and overall survival were investigated. Clinical factors are routinely used in management decisions. Nevertheless, identically staged tumours receiving the same treatment may have different outcomes. Biological factors such as hypoxia, proliferation and radio-sensitivity play an important role in radiation response. However, these are not currently used in practise because tests that are clinically reliable and feasible are not available. High-quality translational research will allow us to develop biological tests that can be used in routine clinical practise to tailor individual treatment, with the ability to improve patient outcome further by modifying the underlying tumour biology.

  13. Differential Mitogenic Effects of Single Chain Hepatocyte Growth Factor (HGF)/Scatter Factor and HGF/NK1 following Cleavage by Factor Xa*

    PubMed Central

    Pediaditakis, Peter; Monga, Satdarshan P. S.; Mars, Wendy M.; Michalopoulos, George K.

    2007-01-01

    Hepatocyte growth factor/scatter factor (HGF/SF) is a multifunctional cytokine that is involved in many normal as well as pathological conditions. HGF/NK1, a splice variant of HGF/SF, has been reported to have either antagonistic or agonistic effects with regard to c-Met signaling depending on the cell type. In these experiments, we have determined that HGF/NK1 is a potent mitogen for rat hepatocytes in culture. Furthermore, we have found that coagulation factor Xa (fXa) is capable of cleaving HGF/NK1 and single chain HGF/SF (scHGF/SF). The products resulting from cleavage of HGF/NK1 or scHGF/SF by fXa appear as single bands under non-reducing conditions. The reaction products from the digestion of HGF/NK1 by fXa were separated under reducing conditions, and the cleavage site, as determined by N-terminal sequencing, was located C-terminal to arginine 134. Previous work established that the heparin-binding domain for HGF/SF is located in the N domain of HGF/SF. Additionally, the dimerization of the HGF/SF receptor (c-Met) by the ligand HGF/NK1 is facilitated by heparin and related sulfonated sugars on the cell surface, whereas heparin is not required for HGF/SF-mediated dimerization. Cleavage of single chain HGF/SF or HGF/NK1 by factor Xa does not alter the affinity of the respective molecules for heparin, but it did variably affect the associated mitogenic activity of these factors. The associated mitogenic activity of HGF/NK1 was reduced by more than 90%, whereas the mitogenic activity of scHGF/SF was unaffected. This suggests mandatory maintenance of a steric interaction of the N domain and the first kringle domain for HGF/NK1 to act as an agonist for rat hepatocyte growth but is not required by full-length HGF/SF. PMID:11832492

  14. Dysphagia in Head and Neck Cancer Patients: Pretreatment Evaluation, Predictive Factors, and Assessment during Radio-Chemotherapy, Recommendations.

    PubMed

    Denaro, Nerina; Merlano, Marco C; Russi, Elvio G

    2013-09-01

    Progress in head and neck cancer (HNC) therapies has improved tumor response, loco-regional control, and survival. However, treatment intensification also increases early and late toxicities. Dysphagia is an underestimated symptom in HNC patients. Impairment of swallowing process could cause malnutrition, dehydration, aspiration, and pneumonia. A comprehensive literature review finalized in May 2012 included searches of electronic databases (Medline, Embase, and CAB abstracts) and scientific societies meetings materials (American Society of Clinical Oncology, Associazione Italiana Radioterapia Oncologica, Associazione Italiana di Oncologia Cervico-Cefalica, American Head and Neck Society, and European Society for Medical Oncology). Hand-searches of HNC journals and reference lists were carried out. Approximately one-third of dysphagia patients developed pneumonia requiring treatment. Aspiration pneumonia associated mortality ranged from 20% to 65%. Unidentified dysphagia caused significant morbidity, increased mortality, and decreased the quality of life. In this review we underline definition, causes, predictive factors of dysphagia and report on pretreatment and on-treatment evaluation, suggesting some key points to avoid underestimation. A multi-parameter assessment of swallowing problems may allow an earlier diagnosis. An appropriate evaluation might lead to a better treatment of both symptoms and cancer.

  15. Head injury attenders in the emergency department: the impact of advice and factors associated with early symptom outcome.

    PubMed

    McMillan, T M; McKenzie, P; Swann, I J; Weir, C J; McAviney, A

    2009-06-01

    Many who attend hospital after head injury are not admitted to a hospital bed. This study explores the views of hospital attenders about advice received, predictors of memory for and compliance with advice and factors associated with early symptom persistence and outcome that might identify those requiring follow-up. A single group prospective follow-up design. Relationships between information obtained by emergency department (ED) staff during admission and about satisfaction with and memory for advice and about symptom persistence was compared in 200 attenders with head injury who were not admitted to hospital. The telephone interview comprised a structured interview and the Post-Concussional Symptoms Checklist. Satisfaction with advice was high. Despite this, a minority remembered advice (alcohol/drugs 44%; medication 38%; rest/sleep 56%; work 36%; sport 36%). At follow-up, symptom complaints were not predicted by information obtained in the ED. Attenders with retrospectively assessed post-traumatic amnesia (PTA) for more than 5 minutes reported more symptoms and poorer memory for advice at follow-up. Although satisfaction with advice was high, memory for advice was relatively poor and was associated with longer durations of PTA. Attenders with PTA > 5 minutes should be targeted for follow-up or inpatient admission.

  16. Dysphagia in Head and Neck Cancer Patients: Pretreatment Evaluation, Predictive Factors, and Assessment during Radio-Chemotherapy, Recommendations

    PubMed Central

    Merlano, Marco C.; Russi, Elvio G.

    2013-01-01

    Progress in head and neck cancer (HNC) therapies has improved tumor response, loco-regional control, and survival. However, treatment intensification also increases early and late toxicities. Dysphagia is an underestimated symptom in HNC patients. Impairment of swallowing process could cause malnutrition, dehydration, aspiration, and pneumonia. A comprehensive literature review finalized in May 2012 included searches of electronic databases (Medline, Embase, and CAB abstracts) and scientific societies meetings materials (American Society of Clinical Oncology, Associazione Italiana Radioterapia Oncologica, Associazione Italiana di Oncologia Cervico-Cefalica, American Head and Neck Society, and European Society for Medical Oncology). Hand-searches of HNC journals and reference lists were carried out. Approximately one-third of dysphagia patients developed pneumonia requiring treatment. Aspiration pneumonia associated mortality ranged from 20% to 65%. Unidentified dysphagia caused significant morbidity, increased mortality, and decreased the quality of life. In this review we underline definition, causes, predictive factors of dysphagia and report on pretreatment and on-treatment evaluation, suggesting some key points to avoid underestimation. A multi-parameter assessment of swallowing problems may allow an earlier diagnosis. An appropriate evaluation might lead to a better treatment of both symptoms and cancer. PMID:24069513

  17. Treatment choice for locally advanced head and neck cancers on the basis of risk factors: biological risk factors.

    PubMed

    Braakhuis, B J M; Brakenhoff, R H; Leemans, C René

    2012-09-01

    Patients with locally advanced head and neck squamous cell carcinoma often experience relapse, the cause of poor survival statistics. Relapse occurs following the three main types of treatment, surgery with or without post-operative (chemo)radiotherapy, or chemoradiation (containing cisplatin). Cancer relapse can result from (i) outgrowth of residual tumour cells, sometimes with a number too small to be detected by routine histopathology or (ii) development of another carcinoma in a field of pre-neoplastic cells that has remained after treatment of the primary carcinoma. At this moment, clinical staging is not enough to identify patients who will develop relapse and who need tailored treatment. This review describes the latest knowledge of mechanisms of cancer relapse, addresses the biomarkers of potential interest detectable in the tissue of the tumour or its surgical margins and discusses three biomarkers, human papillomavirus, TP53 and epidermal growth receptor in more detail. Once a marker panel has been established, treatment should be focussed on the patients at risk of relapse by improved tailoring of existing treatment modalities. Also, the implementation of more targeting therapies based on the characteristics of the discovered markers should lead to better survival rates.

  18. Epidermal growth factor receptor (EGFR) polymorphisms and survival in head and neck cancer patients.

    PubMed

    Bandrés, Eva; Barricarte, Rubén; Cantero, Cristina; Honorato, Beatriz; Malumbres, Raquel; Zárate, Ruth; Alcalde, Juan; García-Foncillas, Jesús

    2007-08-01

    EGFR overexpression has been implicated in the development of head and neck squamous cell carcinoma (HNSCC). This study evaluates the prognostic ability of four polymorphisms in EGFR gene for patients diagnosed with HNSCC and treated with chemoradiation. EGFR polymorphisms in the promoter region were not associated with clinical or pathological characteristics. In relation to R497K polymorphism, patients with the Arg/Arg genotype showed the highest risk of disease-specificity mortality and none of the patients with the Lys/Lys genotype died throughout the follow-up period of the study. Patients with (CA)(n) repeats <17 in both alleles tended toward inferior overall survival compared with those with (CA)(n) repeats > or = 17 in both alleles (p=0.07). Moreover, the distribution of patients with any (CA)(n) repeats > or = 17 and both alleles <17 was statistically different across patients who were recorded as having partial response or no response to therapy (p=0.034). Combination analysis of both polymorphisms, (CA)(n) repeats and R497K, suggests that these polymorphisms may be associated with clinical outcome in patients treated with chemoradiation.

  19. Regional neural tube closure defined by the Grainy head-like transcription factors.

    PubMed

    Rifat, Yeliz; Parekh, Vishwas; Wilanowski, Tomasz; Hislop, Nikki R; Auden, Alana; Ting, Stephen B; Cunningham, John M; Jane, Stephen M

    2010-09-15

    Primary neurulation in mammals has been defined by distinct anatomical closure sites, at the hindbrain/cervical spine (closure 1), forebrain/midbrain boundary (closure 2), and rostral end of the forebrain (closure 3). Zones of neurulation have also been characterized by morphologic differences in neural fold elevation, with non-neural ectoderm-induced formation of paired dorso-lateral hinge points (DLHP) essential for neural tube closure in the cranial and lower spinal cord regions, and notochord-induced bending at the median hinge point (MHP) sufficient for closure in the upper spinal region. Here we identify a unifying molecular basis for these observations based on the function of the non-neural ectoderm-specific Grainy head-like genes in mice. Using a gene-targeting approach we show that deletion of Grhl2 results in failed closure 3, with mutants exhibiting a split-face malformation and exencephaly, associated with failure of neuro-epithelial folding at the DLHP. Loss of Grhl3 alone defines a distinct lower spinal closure defect, also with defective DLHP formation. The two genes contribute equally to closure 2, where only Grhl gene dosage is limiting. Combined deletion of Grhl2 and Grhl3 induces severe rostral and caudal neural tube defects, but DLHP-independent closure 1 proceeds normally in the upper spinal region. These findings provide a molecular basis for non-neural ectoderm mediated formation of the DLHP that is critical for complete neuraxis closure. (c) 2010 Elsevier Inc. All rights reserved.

  20. Is absolute hypovolemia a risk factor for vasovagal response to head-up tilt?

    PubMed

    Jaeger, F J; Maloney, J D; Castle, L W; Fouad-Tarazi, F M

    1993-04-01

    To test the hypothesis that hypovolemia is associated with an increased incidence of vasovagal syncope during head-up tilt (HUT) 45 patients with history of syncope or presyncope were studied. Blood volume (radio-iodinated serum albumin) was determined, then subjects underwent a graded HUT (from 15 degrees-60 degrees HUT) with cuff blood pressure and ECG monitoring. All patients were kept on their own medications during evaluation. Thirty patients (12 male, 18 female, mean age 50 +/- 19 [SD] years) had hypovolemia, defined as blood volume < 90% of lab normal for corresponding sex, while 15 patients (7 male, 8 female, mean age 52 +/- 21 years) were normovolemic with blood volume ranging from 91%-110% of sex-matched normal subjects. The normovolemic patients served as controls. During HUT, a vasovagal response was elicited in 5 of the 30 hypovolemics and in 4 of the 15 normovolemic (16.7% and 26.7%, respectively, P = NS). In those who developed vasovagal response, the changes of heart rate and blood pressure during HUT were not significantly different between hypovolemics and normovolemics, neither at the endpoint (vasovagal response) nor immediately before the development of the vasovagal response. In patients with nonvasovagal events, four types of hemodynamic responses to tilt were observed: normal blood pressure response associated with normal heart rate increase, normal blood pressure response in association with accentuated increase in heart rate, orthostatic hypotension with normal acceleration of heart rate, and orthostatic hypotension with accelerated increase in heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Interleaved segment correction achieves higher improvement factors in using genetic algorithm to optimize light focusing through scattering media

    NASA Astrophysics Data System (ADS)

    Li, Runze; Peng, Tong; Liang, Yansheng; Yang, Yanlong; Yao, Baoli; Yu, Xianghua; Min, Junwei; Lei, Ming; Yan, Shaohui; Zhang, Chunmin; Ye, Tong

    2017-10-01

    Focusing and imaging through scattering media has been proved possible with high resolution wavefront shaping. A completely scrambled scattering field can be corrected by applying a correction phase mask on a phase only spatial light modulator (SLM) and thereby the focusing quality can be improved. The correction phase is often found by global searching algorithms, among which Genetic Algorithm (GA) stands out for its parallel optimization process and high performance in noisy environment. However, the convergence of GA slows down gradually with the progression of optimization, causing the improvement factor of optimization to reach a plateau eventually. In this report, we propose an interleaved segment correction (ISC) method that can significantly boost the improvement factor with the same number of iterations comparing with the conventional all segment correction method. In the ISC method, all the phase segments are divided into a number of interleaved groups; GA optimization procedures are performed individually and sequentially among each group of segments. The final correction phase mask is formed by applying correction phases of all interleaved groups together on the SLM. The ISC method has been proved significantly useful in practice because of its ability to achieve better improvement factors when noise is present in the system. We have also demonstrated that the imaging quality is improved as better correction phases are found and applied on the SLM. Additionally, the ISC method lowers the demand of dynamic ranges of detection devices. The proposed method holds potential in applications, such as high-resolution imaging in deep tissue.

  2. DNA-Directed Assembly of Nanogold Dimers: A Unique Dynamic Light Scattering Sensing Probe for Transcription Factor Detection

    NASA Astrophysics Data System (ADS)

    Seow, Nianjia; Tan, Yen Nee; Yung, Lin-Yue Lanry; Su, Xiaodi

    2015-12-01

    We have developed a unique DNA-assembled gold nanoparticles (AuNPs) dimer for dynamic light scattering (DLS) sensing of transcription factors, exemplified by estrogen receptor (ER) that binds specifically to a double-stranded (ds) DNA sequence containing estrogen response element (ERE). Here, ERE sequence is incorporated into the DNA linkers to bridge the AuNPs dimer for ER binding. Coupled with DLS, this AuNP dimer-based DLS detection system gave distinct readout of a single ‘complex peak’ in the presence of the target molecule (i.e., ER). This unique signature marked the first time that such nanostructures can be used to study transcription factor-DNA interactions, which DLS alone cannot do. This was also unlike previously reported AuNP-DLS assays that gave random and broad distribution of particles size upon target binding. In addition, the ERE-containing AuNP dimers could also suppress the light-scattering signal from the unbound proteins and other interfering factors (e.g., buffer background), and has potential for sensitive detection of target proteins in complex biological samples such as cell lysates. In short, the as-developed AuNP dimer probe coupled with DLS is a simple (mix and test), rapid (readout in ~5 min) and sensitive (low nM levels of ER) platform to detect sequence-specific protein-DNA binding event.

  3. DNA-Directed Assembly of Nanogold Dimers: A Unique Dynamic Light Scattering Sensing Probe for Transcription Factor Detection

    PubMed Central

    Seow, Nianjia; Tan, Yen Nee; Yung, Lin-Yue Lanry; Su, Xiaodi

    2015-01-01

    We have developed a unique DNA-assembled gold nanoparticles (AuNPs) dimer for dynamic light scattering (DLS) sensing of transcription factors, exemplified by estrogen receptor (ER) that binds specifically to a double-stranded (ds) DNA sequence containing estrogen response element (ERE). Here, ERE sequence is incorporated into the DNA linkers to bridge the AuNPs dimer for ER binding. Coupled with DLS, this AuNP dimer-based DLS detection system gave distinct readout of a single ‘complex peak’ in the presence of the target molecule (i.e., ER). This unique signature marked the first time that such nanostructures can be used to study transcription factor-DNA interactions, which DLS alone cannot do. This was also unlike previously reported AuNP-DLS assays that gave random and broad distribution of particles size upon target binding. In addition, the ERE-containing AuNP dimers could also suppress the light-scattering signal from the unbound proteins and other interfering factors (e.g., buffer background), and has potential for sensitive detection of target proteins in complex biological samples such as cell lysates. In short, the as-developed AuNP dimer probe coupled with DLS is a simple (mix and test), rapid (readout in ~5 min) and sensitive (low nM levels of ER) platform to detect sequence-specific protein-DNA binding event. PMID:26678946

  4. Individual cell-based models of cell scatter of ARO and MLP-29 cells in response to hepatocyte growth factor.

    PubMed

    Scianna, Marco; Merks, Roeland M H; Preziosi, Luigi; Medico, Enzo

    2009-09-07

    The different behaviors of colonies of two cell lines, ARO (thyroid carcinoma-derived cells) and MLP-29 (mouse liver progenitor cells), in response to hepatocyte growth factor (HGF) are described deducing suitable cellular Potts models (CPM). It is shown how increased motility and decreased adhesiveness are responsible for cell-cell dissociation and tissue invasion in the ARO cells. On the other hand, it is shown that, in addition to the biological mechanisms above, it is necessary to include directional persistence in cell motility and HGF diffusion to describe the scattering and the branching processes characteristic of MLP-29 cells.

  5. Influence of electron-neutral collisions on the Compton scattering cross section and the Salpeter structure factor in warm collisional plasmas

    SciTech Connect

    Song, Mi-Young; Yoon, Jung-Sik; Jung, Young-Dae

    2015-03-15

    The electron-neutral collision effects on the Compton scattering process are investigated in warm collisional plasmas. The Compton scattering cross section in warm collisional plasmas is obtained by the Salpeter structure factor with the fluctuation-dissipation theorem and the plasma dielectric function as a function of the electron-neutral collision frequency, Debye length, and wave number. It is shown that the influence of electron-neutral collision strongly suppresses the Compton scattering cross section in warm collisional plasmas. It is also found that the electron-neutral collision effect on the differential Compton scattering cross section is more significant in forward scattering directions. We show that the differential Compton scattering cross section has a maximum at the scattering angle φ=π/2. In addition, we find that the electron-neutral collision effect on the total Compton scattering cross section increases with increasing Debye length and wave number. The variation of the Compton scattering cross section due to the change of collision frequency and plasma parameters is also discussed.

  6. Jaundice: an important, poorly recognized risk factor for diminished survival in patients with adenocarcinoma of the head of the pancreas

    PubMed Central

    Strasberg, Steven M; Gao, Feng; Sanford, Dominic; Linehan, David C; Hawkins, William G; Fields, Ryan; Carpenter, Danielle H; Brunt, Elizabeth M; Phillips, Carolyn

    2014-01-01

    Objectives: Jaundice impairs cellular immunity, an important defence against the dissemination of cancer. Jaundice is a common mode of presentation in pancreatic head adenocarcinoma. The purpose of this study was to determine whether there is an association between preoperative jaundice and survival in patients who have undergone resection of such tumours. Methods: Thirty possible survival risk factors were evaluated in a database of over 400 resected patients. Univariate analysis was used to determine odds ratio for death. All factors for which a P-value of <0.30 was obtained were entered into a multivariate analysis using the Cox model with backward selection. Results: Preoperative jaundice, age, positive node status, poor differentiation and lymphatic invasion were significant indicators of poor outcome in multivariate analysis. Absence of jaundice was a highly favourable prognostic factor. Interaction emerged between jaundice and nodal status. The benefit conferred by the absence of jaundice was restricted to patients in whom negative node status was present. Five-year overall survival in this group was 66%. Jaundiced patients who underwent preoperative stenting had a survival advantage. Conclusions: Preoperative jaundice is a negative risk factor in adenocarcinoma of the pancreas. Additional studies are required to determine the exact mechanism for this effect. PMID:23600768

  7. Psychological Factors Associated with Head and Neck Cancer Treatment and Survivorship: Evidence and Opportunities for Behavioral Medicine

    PubMed Central

    Howren, M. Bryant; Christensen, Alan J.; Karnell, Lucy Hynds; Funk, Gerry F.

    2012-01-01

    Individuals diagnosed with head and neck cancer (HNC) face not only a potentially life-threatening diagnosis, but must endure treatment that often results in significant, highly visible disfigurement and disruptions of essential functioning, such as deficits or complications in eating, swallowing, breathing, and speech. Each year, approximately 650,000 new cases are diagnosed, making HNC the sixth most common type of cancer in the world. Despite this, however, HNC remains understudied in behavioral medicine. In this article, the authors review available evidence regarding several important psychosocial and behavioral factors associated with HNC diagnosis, treatment, and recovery, as well as various psychosocial interventions conducted in this patient population, before concluding with opportunities for behavioral medicine research and practice. PMID:22963591

  8. Role of macrophage migration inhibitory factor in head and neck cancer and novel therapeutic targets: A systematic review.

    PubMed

    Lechien, Jérôme R; Nassri, Amir; Kindt, Nadege; Brown, David N; Journe, Fabrice; Saussez, Sven

    2017-09-30

    Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine involved in systemic, autoimmune, and inflammatory diseases, such as obesity, rheumatoid arthritis, and systemic lupus erythematosus. For the 2 past decades, MIF has been reported to participate in carcinogenesis, disease prognosis, tumor cell proliferation, invasion, and tumor-induced angiogenesis in many cancers. The purpose of this article is to review published experimental and clinical data for MIF and its involvement in upper aerodigestive tract cancers. Based on the current literature, we propose a biomolecular model describing the mechanisms underlying the involvement of MIF in the initiation, progression, apoptosis, and proliferation of head and neck tumor cells. In reference to this model, potential therapeutic approaches based on the use of MIF antagonists and neutralizing antibodies are described. It is concluded that MIF is a promising target for future therapeutic strategies, both with and without chemoradiation strategies. © 2017 Wiley Periodicals, Inc.

  9. Factors influencing survival of free-flap in reconstruction for cancer of the head and neck: a literature review.

    PubMed

    Kruse, Astrid L D; Luebbers, Heinz T; Grätz, Klaus W; Obwegeser, Joachim A

    2010-01-01

    Microvascular free tissue transfer is a reliable technique for head and neck reconstruction with success rates of 90-99%. Currently, there is no consensus concerning antithrombotic agents, antibiotics, or monitoring techniques. Therefore, the aim of this study was to review current literature dealing with microvascular free-tissue transfer and factors influencing the outcome. In addition to excellent microsurgical techniques, coupling devices are a promising new technique, but are not useful in all arteries. Antibiotics should be given in three doses, as a more lengthy dosage time seems to have no advantage. The risk for elderly patients can be best assessed by the American Society of Anesthesiologists (ASA) score, but early mobilization, including intense chest physiotherapy, is important. Anticoagulation can be considered in cases of small vessels, significant size mismatch, vein graft, or vessels of poor quality. Monitoring should be done hourly during the first 24 hours and then every 4 hours for the next 2 postoperative days.

  10. Quality of life associated factors in head and neck cancer patients in a developing country using the FACT-H&N.

    PubMed

    Bilal, Sobia; Doss, Jennifer Geraldine; Cella, David; Rogers, Simon N

    2015-03-01

    Health-related quality of life (HRQoL) associated factors are vital considerations prior to treatment decision-making for head and neck cancer patients. The study aimed to identify potential socio-demographic and clinical prognostic value of HRQoL in head and neck cancer patients in a developing country. The Functional Assessment of Cancer Therapy-Head and Neck (FACT-H&N)-V4 in Urdu language was administered among 361 head and neck cancer patients. Data were statistically tested through multivariate analysis of variance (MANOVA) and regression modeling to identify the potentially associated factors. Treatment status, tumor stage and tumor site had the strongest negative impact on patients HRQoL, with a statistically significant decrement in FACT summary scales (effect size >0.15). Moderate associated factors of HRQoL included treatment type, marital status, employment status and age (effect size range 0.06-0.15). Weak associated factors of HRQoL with a small effect size (>0.01-0.06) included tumor size and type, gender, education level and ethnicity. This study reports 12 socio-demographic and clinical variables that have a significant impact on HRQoL of head, and neck cancer patients, and that should be considered during treatment decision-making by multidisciplinary teams and also in future HRQoL studies conducted in other developing countries. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. All rights reserved.

  11. Sensitivity of scattering and absorbing aerosol direct radiative forcing to physical climate factors

    NASA Astrophysics Data System (ADS)

    Ocko, Ilissa B.; Ramaswamy, V.; Ginoux, Paul; Ming, Yi; Horowitz, Larry W.

    2012-10-01

    The direct radiative forcing of the climate system includes effects due to scattering and absorbing aerosols. This study explores how important physical climate characteristics contribute to the magnitudes of the direct radiative forcings (DRF) from anthropogenic sulfate, black carbon, and organic carbon. For this purpose, we employ the GFDL CM2.1 global climate model, which has reasonable aerosol concentrations and reconstruction of twentieth-century climate change. Sulfate and carbonaceous aerosols constitute the most important anthropogenic aerosol perturbations to the climate system and provide striking contrasts between primarily scattering (sulfate and organic carbon) and primarily absorbing (black carbon) species. The quantitative roles of cloud coverage, surface albedo, and relative humidity in governing the sign and magnitude of all-sky top-of-atmosphere (TOA) forcings are examined. Clouds reduce the global mean sulfate TOA DRF by almost 50%, reduce the global mean organic carbon TOA DRF by more than 30%, and increase the global mean black carbon TOA DRF by almost 80%. Sulfate forcing is increased by over 50% as a result of hygroscopic growth, while high-albedo surfaces are found to have only a minor (less than 10%) impact on all global mean forcings. Although the radiative forcing magnitudes are subject to uncertainties in the state of mixing of the aerosol species, it is clear that fundamental physical climate characteristics play a large role in governing aerosol direct radiative forcing magnitudes.

  12. High triglyceride is a risk factor for silent osteonecrosis of the femoral head in systemic lupus erythematosus.

    PubMed

    Kuroda, Takeshi; Tanabe, Naohito; Wakamatsu, Ayako; Takai, Chinatsu; Sato, Hiroe; Nakatsue, Takeshi; Wada, Yoko; Nakano, Masaaki; Narita, Ichiei

    2015-12-01

    The purpose of this study was to clarify the factors related to silent osteonecrosis of the femoral head (ONFH) in patients with systemic lupus erythematosus (SLE). Seventy-eight patients with SLE were selected on the basis of having been newly diagnosed and requiring high-dose prednisolone, including pulse therapy with methylprednisolone, as the initial treatment. All the patients initially underwent MRI at 3 months after the start of corticosteroid treatment to detect any early changes in the femoral head. These examinations were then performed again 3 months later. Laboratory parameters were evaluated at the start of steroid treatment and at 1 month thereafter. By 3 months after the start of corticosteroid treatment, silent ONFH was diagnosed by MRI in 21 patients (26.9 %), being bilateral in 11 patients and unilateral in 10. The occurrence of silent ONFH was not related to SLE disease activity index, serological activity, or renal function; it was also unrelated to body mass index (BMI), body surface area (BSA), and the initial dose of prednisolone per unit body weight. However, the total cholesterol level at 4 weeks after the start of steroid treatment tended to be higher in patients with silent ONFH. Patients with a higher triglyceride level showed a significantly higher frequency of silent ONFH both before (p = 0.002) and 4 weeks after (p = 0.036) steroid initiation.A high triglyceride level is an important risk factor for silent ONFH in patients with SLE, and large-scale epidemiologic surveys of such early events are needed in this patient population.

  13. Differential optical absorption spectroscopy (DOAS) and air mass factor concept for a multiply scattering vertically inhomogeneous medium: theoretical consideration

    NASA Astrophysics Data System (ADS)

    Rozanov, V. V.; Rozanov, A. V.

    2010-06-01

    The Differential Optical Absorption Spectroscopy (DOAS) technique is widely used to retrieve amounts of atmospheric species from measurements of the direct solar light transmitted through the Earth's atmosphere as well as of the solar light scattered in the atmosphere or reflected from the Earth's surface. For the transmitted direct solar light the theoretical basis of the DOAS technique represented by the Beer-Lambert law is well studied. In contrast, scarcely investigated is the theoretical basis and validity range of the DOAS method for those cases where the contribution of the multiple scattering processes is not negligible. Our study is intended to fill this gap by means of a theoretical investigation of the applicability of the DOAS technique for the retrieval of amounts of atmospheric species from observations of the scattered solar light with a non-negligible contribution of the multiple scattering. Starting from the expansion of the intensity logarithm in the functional Taylor series we formulate the general form of the DOAS equation. The thereby introduced variational derivative of the intensity logarithm with respect to the variation of the gaseous absorption coefficient, which is often referred to as the weighting function, is demonstrated to be closely related to the air mass factor. Employing some approximations we show that the general DOAS equation can be rewritten in the form of the weighting function (WFDOAS), the modified (MDOAS), and the standard DOAS equations. For each of these forms a specific equation for the air mass factor follows which, in general, is not suitable for other forms of the DOAS equation. Furthermore, the validity range of the standard DOAS equation is quantitatively investigated using a suggested criterion of a weak absorption. The results presented in this study are intended to provide a basis for a better understanding of the applicability range of different forms of the DOAS equation as well as of the relationship between

  14. Differential optical absorption spectroscopy (DOAS) and air mass factor concept for a multiply scattering vertically inhomogeneous medium: theoretical consideration

    NASA Astrophysics Data System (ADS)

    Rozanov, V. V.; Rozanov, A. V.

    2010-02-01

    The Differential Optical Absorption Spectroscopy (DOAS) technique is widely used to retrieve amounts of atmospheric species from measurements of the direct solar light transmitted through the Earth's atmosphere as well as of the solar light scattered in the atmosphere or reflected from the Earth's surface. For the transmitted direct solar light the theoretical basis of the DOAS technique represented by the Beer-Lambert law is well studied. In contrast, scarcely investigated is the theoretical basis and validity range of the DOAS method for those cases where the contribution of the multiple scattering processes is not negligible. Our study is intended to fill this gap by means of a theoretical investigation of the applicability of the DOAS technique for the retrieval of amounts of atmospheric species from observations of the scattered solar light with a non-negligible contribution of the multiple scattering. Starting from the expansion of the intensity logarithm in the functional Taylor series we formulate the general form of the DOAS equation. The thereby introduced variational derivative of the intensity logarithm with respect to the variation of the gaseous absorption coefficient, which is often referred to as the weighting function, is demonstrated to be closely related to the air mass factor. Employing some approximations we show that the general DOAS equation can be rewritten in the form of the weighting function (WFDOAS), the modified (MDOAS), and the standard DOAS equations. For each of these forms a specific equation for the air mass factor follows which, in general, is not suitable for other forms of the DOAS equation. Furthermore, the validity range of the standard DOAS equation is quantitatively investigated using a suggested criterion of a weak absorption. The results presented in this study are intended to provide a basis for a better understanding of the applicability range of different forms of the DOAS equation as well as of the relationship between

  15. Parental Factors Correlated with Developmental Outcome in the Migrant Head Start Child.

    ERIC Educational Resources Information Center

    Siantz, Mary Lou de Leon; Smith, M. Shelton

    1994-01-01

    Examined parental factors correlated with developmental outcomes among 60 Mexican American migrant farmworker children. Found that maternal parenting style accounted for a significant amount of the variance in child behavior problems reported by the mothers, whereas maternal social support helped to explain the variance in peer acceptance reported…

  16. Parental Factors Correlated with Developmental Outcome in the Migrant Head Start Child.

    ERIC Educational Resources Information Center

    Siantz, Mary Lou de Leon; Smith, M. Shelton

    1994-01-01

    Examined parental factors correlated with developmental outcomes among 60 Mexican American migrant farmworker children. Found that maternal parenting style accounted for a significant amount of the variance in child behavior problems reported by the mothers, whereas maternal social support helped to explain the variance in peer acceptance reported…

  17. New Measurement of Parity Violation in Elastic Electron-Proton Scattering and Implications for Strange Form Factors

    SciTech Connect

    Konrad Aniol; David Armstrong; Todd Averett; Maud Baylac; Etienne Burtin; John Calarco; Gordon Cates; Christian Cavata; Zhengwei Chai; C. Chang; Jian-Ping Chen; Eugene Chudakov; Evaristo Cisbani; Marius Coman; Daniel Dale; Alexandre Deur; Pibero Djawotho; Martin Epstein; Stephanie Escoffier; Lars Ewell; Nicolas Falletto; John Finn; A. Fleck; Bernard Frois; Salvatore Frullani; Juncai Gao; Franco Garibaldi; Ashot Gasparian; G. M. Gerstner; Ronald Gilman; Oleksandr Glamazdin; Javier Gomez; Viktor Gorbenko; Jens-ole Hansen; F. Hersman; Douglas Higinbotham; Richard Holmes; Maurik Holtrop; Thomas Humensky; Sebastien Incerti; Mauro Iodice; Cornelis De Jager; Johann Jardillier; Xiaodong Jiang; Mark Jones; J. Jorda; Christophe Jutier; W. Kahl; James Kelly; Donghee Kim; M. -J. Kim; Minsuk Kim; Ioannis Kominis; Edgar Kooijman; Kevin Kramer; Krishna Kumar; Michael Kuss; John LeRose; Raffaele De Leo; M. Leuschner; David Lhuillier; Meihua Liang; Nilanga Liyanage; R. Lourie; Richard Madey; Sergey Malov; Demetrius Margaziotis; Frederic Marie; Pete Markowitz; Jacques Martino; Peter Mastromarino; Kathy McCormick; Justin McIntyre; Zein-Eddine Meziani; Robert Michaels; Brian Milbrath; Gerald Miller; Joseph Mitchell; Ludyvine Morand; Damien Neyret; Gerassimos Petratos; Roman Pomatsalyuk; John Price; David Prout; Thierry Pussieux; Gilles Quemener; Ronald Ransome; David Relyea; Yves Roblin; Julie Roche; Gary Rutledge; Paul Rutt; Marat Rvachev; Franck Sabatie; Arunava Saha; Paul Souder; Marcus Spradlin; Steffen Strauch; Riad Suleiman; Jeffrey Templon; T. Teresawa; James Thompson; Raphael Tieulent; Luminita Todor; Baris Tonguc; Paul Ulmer; Guido Urciuoli; Branislav Vlahovic; Krishni Wijesooriya; R. Wilson; Bogdan Wojtsekhowski; Rhett Woo; Wang Xu; Imran Younus; C. Zhang

    2001-06-01

    We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton. The result is A = -15.05 +- 0.98(stat) {+-} 0.56(syst) ppm at the kinematic point theta{sub lab} = 12.3 degrees and Q{sup 2} = 0.477 (GeV/c){sup 2}. The measurement implies that the value for the strange form factor (G{sub E}{sup s} + 0.392 G{sub M}{sup s})/(G{sub M}{sup p} {mu}{sub p}) = 0.069 +- 0.056 +- 0.039, where the first error is experimental and the second arises from the uncertainties in electromagnetic form factors. This measurement is the first fixed-target parity violation experiment that used either a ''strained'' GaAs photocathode to produce highly polarized electrons or a Compton polarimeter to continuously monitor the electron beam polarization.

  18. Surface-enhanced Raman scattering enhancement factor distribution for nanoparticles of arbitrary shapes using surface integral equation method

    NASA Astrophysics Data System (ADS)

    Ying Huang, Shao; Wu, Bae-Ian; Foong, Shaohui

    2013-01-01

    Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) surface integral equation method is applied for the first time to accurately estimate the surface-enhanced Raman scattering (SERS) enhancement factor distribution for arbitrary nanoparticles and nano-aggregates. It is the first time in literature that the distributions of SERS enhancement factors of nanoparticles of a large variety are reported. It is shown that not every SERS substrate exhibits a long-tail distribution as a dimer consisting of two spheres in close proximity. Generic methods are proposed to evaluate the performance of nanoparticles on SERS substrates. A cumulative distribution is proposed to examine the contributions of hot and warm spots around the nanoparticles. It is used to identify the importance of warm spots on a SERS substrate. A parameter q is proposed to describe the likelihood of a randomly positioned molecule that can be activated. This study provides guidance and insights for the optimization of SERS substrate fabrication techniques.

  19. The control of male fertility by spermatid-specific factors: searching for contraceptive targets from spermatozoon's head to tail

    PubMed Central

    Chen, Su-Ren; Batool, Aalia; Wang, Yu-Qian; Hao, Xiao-Xia; Chang, Chawn-Shang; Cheng, C Yan; Liu, Yi-Xun

    2016-01-01

    Male infertility due to abnormal spermatozoa has been reported in both animals and humans, but its pathogenic causes, including genetic abnormalities, remain largely unknown. On the other hand, contraceptive options for men are limited, and a specific, reversible and safe method of male contraception has been a long-standing quest in medicine. Some progress has recently been made in exploring the effects of spermatid-specifical genetic factors in controlling male fertility. A comprehensive search of PubMed for articles and reviews published in English before July 2016 was carried out using the search terms ‘spermiogenesis failure', ‘globozoospermia', ‘spermatid-specific', ‘acrosome', ‘infertile', ‘manchette', ‘sperm connecting piece', ‘sperm annulus', ‘sperm ADAMs', ‘flagellar abnormalities', ‘sperm motility loss', ‘sperm ion exchanger' and ‘contraceptive targets'. Importantly, we have opted to focus on articles regarding spermatid-specific factors. Genetic studies to define the structure and physiology of sperm have shown that spermatozoa appear to be one of the most promising contraceptive targets. Here we summarize how these spermatid-specific factors regulate spermiogenesis and categorize them according to their localization and function from spermatid head to tail (e.g., acrosome, manchette, head-tail conjunction, annulus, principal piece of tail). In addition, we emphatically introduce small-molecule contraceptives, such as BRDT and PPP3CC/PPP3R2, which are currently being developed to target spermatogenic-specific proteins. We suggest that blocking the differentiation of haploid germ cells, which rarely affects early spermatogenic cell types and the testicular microenvironment, is a better choice than spermatogenic-specific proteins. The studies described here provide valuable information regarding the genetic and molecular defects causing male mouse infertility to improve our understanding of the importance of spermatid

  20. The pathogenic role of transforming growth factor-β2 in glaucomatous damage to the optic nerve head.

    PubMed

    Fuchshofer, Rudolf

    2011-08-01

    In patients with primary open angle glaucoma (POAG), the optic nerve head (ONH) shows characteristic cupping correlated with visual field defects. The progressive optic neuropathy is characterized by irreversible loss of retinal ganglion cells (RGC). The critical risk factor for axonal damage at the ONH is an elevated intraocular pressure (IOP). The increase in IOP correlates with axonal loss in the ONH, which might be due to an impaired axoplasmatic flow leading to the loss of RGCs. Damage to the optic nerve is thought to occur in the lamina cribrosa (LC) region of the ONH, which is composed of characteristic sieve-like connective tissue cribriform plates through which RGC axons exit the eye. The cupping of the optic disc, and the compression and excavation of LC are characteristic signs of glaucomatous ONH remodelling. In ONH of POAG patients a disorganized distribution and deposition of elastic fibers and a typical pronounced thickening of the connective tissue septae surrounding the optic nerve fibers is found. Transforming growth factor (TGF)-β2 could be one of the pathogenic factors responsible for the structural alterations in POAG patients as the TGF-β2 levels in the ONH of glaucomatous eyes are elevated as well as in the aqueous homour. TGF-β2 leads to an increased synthesis of extracellular matrix (ECM) molecules mediated by connective tissue growth factor and to an impaired ECM degradation in cultured ONH astrocytes. Bone morphogenetic protein (BMP)-4 effectively antagonizes the effects of TGF-β2 on matrix deposition. The BMP antagonist gremlin blocks this inhibition, allowing TGF-β2 stimulation of ECM synthesis. Overall, the ECM in the ONH is kept in balance in the OHN by factors that augment or block the activity of TGF-β2.

  1. Lifestyle Factors in Cancer Survivorship: Where We Are and Where We Are Headed

    PubMed Central

    Vijayvergia, Namrata; Denlinger, Crystal S.

    2015-01-01

    Advances in early detection and curative therapies have led to an increased number of cancer survivors over the last twenty years. With this population comes the need to evaluate the late and long term effects of cancer treatment and develop recommendations about how to optimally care for these survivors. Lifestyle factors (diet, body weight, physical activity, and smoking) have been linked to a higher risk of many medical comorbidities (cardiovascular, metabolic, etc.). There is increasing evidence linking these factors to the risk of developing cancer and likely cancer-related outcomes. This link has been studied extensively in common cancers like breast, colon, prostate, and lung cancers through observational studies and is now being prospectively evaluated in interventional studies. Realizing that survivors are highly motivated to improve their overall health after a diagnosis of cancer, healthy lifestyle recommendations from oncology providers can serve as a strong tool to motivate survivors to adopt health behavior changes. Our article aims to review the evidence that links lifestyle factors to cancer outcomes and provides clinical recommendations for cancer survivors. PMID:26147495

  2. Head Lice

    MedlinePlus

    Head lice are parasitic wingless insects. They live on people's heads and feed on their blood. An adult louse ... Children ages 3-11 and their families get head lice most often. Personal hygiene has nothing to ...

  3. Head Lice

    MedlinePlus

    ... Schedules Nutrient Shortfall Questionnaire Home Diseases and Conditions Head Lice Head Lice Condition Family HealthKids and Teens Share Head Lice Table of Contents1. Overview2. Symptoms3. Causes4. Prevention5. ...

  4. Head circumference

    MedlinePlus

    ... a child's head circumference. Normal ranges for a child's sex and age (weeks, months), based on values that experts have obtained for normal growth rates of infants' and children's heads. Measurement of the head circumference is an ...

  5. Internal scatter, the unavoidable major component of the peripheral dose in photon-beam radiotherapy.

    PubMed

    Chofor, Ndimofor; Harder, Dietrich; Willborn, Kay C; Poppe, Björn

    2012-03-21

    In clinical photon beams, the dose outside the geometrical field limits is produced by photons originating from (i) head leakage, (ii) scattering at the beam collimators and the flattening filter (head scatter) and (iii) scattering from the directly irradiated region of the patient or phantom (internal scatter). While the first two components can be modified, e.g. by reinforcement of shielding components or by re-modeling the filter system, internal scatter remains an unavoidable contributor to the peripheral dose. Its relative magnitude compared to the other components, its numerical variation with beam energy, field size and off-axis distance as well as its spectral distribution are evaluated in this study. We applied a detailed Monte Carlo (MC) model of our 6/15 MV Siemens Primus linear accelerator beam head, provided with ideal head leakage shielding conditions (multi-leaf collimator without gaps) to assess the head scatter contribution. Experimental values obtained under real shielding conditions were used to evaluate the head leakage contribution. It was found that the MC-computed internal scatter doses agree with the results of our previous measurements, that internal scatter is the major contributor to the peripheral dose in the near periphery while head leakage prevails in the far periphery, and that the lateral decline of the internal scatter dose can be represented by the sum of two exponentials, with an asymptotic tenth value of 18 to 19 cm. Internal scatter peripheral doses from various elementary beams are additive, so that their sum increases approximately in proportion with field size. The ratio between normalized internal scatter doses at 6 and 15 MV is approximately 2:1. The energy fluence spectra of the internal scatter component at all points of interest outside the field have peaks near 500 keV. The fact that the energy-shifted internal scatter constitutes the major contributor to the dose in the near periphery has a general bearing for

  6. Internal scatter, the unavoidable major component of the peripheral dose in photon-beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Chofor, Ndimofor; Harder, Dietrich; Willborn, Kay C.; Poppe, Björn

    2012-03-01

    In clinical photon beams, the dose outside the geometrical field limits is produced by photons originating from (i) head leakage, (ii) scattering at the beam collimators and the flattening filter (head scatter) and (iii) scattering from the directly irradiated region of the patient or phantom (internal scatter). While the first two components can be modified, e.g. by reinforcement of shielding components or by re-modeling the filter system, internal scatter remains an unavoidable contributor to the peripheral dose. Its relative magnitude compared to the other components, its numerical variation with beam energy, field size and off-axis distance as well as its spectral distribution are evaluated in this study. We applied a detailed Monte Carlo (MC) model of our 6/15 MV Siemens Primus linear accelerator beam head, provided with ideal head leakage shielding conditions (multi-leaf collimator without gaps) to assess the head scatter contribution. Experimental values obtained under real shielding conditions were used to evaluate the head leakage contribution. It was found that the MC-computed internal scatter doses agree with the results of our previous measurements, that internal scatter is the major contributor to the peripheral dose in the near periphery while head leakage prevails in the far periphery, and that the lateral decline of the internal scatter dose can be represented by the sum of two exponentials, with an asymptotic tenth value of 18 to 19 cm. Internal scatter peripheral doses from various elementary beams are additive, so that their sum increases approximately in proportion with field size. The ratio between normalized internal scatter doses at 6 and 15 MV is approximately 2:1. The energy fluence spectra of the internal scatter component at all points of interest outside the field have peaks near 500 keV. The fact that the energy-shifted internal scatter constitutes the major contributor to the dose in the near periphery has a general bearing for

  7. Expression and clinical significance of connective tissue growth factor in advanced head and neck squamous cell cancer.

    PubMed

    Kikuchi, Ryoko; Kikuchi, Yoshihiro; Tsuda, Hitoshi; Maekawa, Hitoshi; Kozaki, Ken-Ichi; Imoto, Issei; Tamai, Seiichi; Shiotani, Akihiro; Iwaya, Keiichi; Sakamoto, Masaru; Sekiya, Takao; Matsubara, Osamu

    2014-07-01

    Connective tissue growth factor (CTGF) has been reported to play critical roles in the tumorigenesis of several human malignancies. This study was performed to evaluate CTGF protein expression in head and neck squamous cell carcinoma (HNSCC). Surgical specimens from 76 primary HNSCC were obtained with written informed consents and the expression level of CTGF was immunohistochemically evaluated. The cytoplasmic immunoreactivity of CTGF in cancer cells was semiquantitatively classified into low and high expression. Among all 76 cases with or without neoadjuvant therapy, low CTGF showed significantly longer (P = 0.0282) overall survival (OS), but not disease-free survival (DFS) than high CTGF. Although low CTGF in patients with stage I, II and III did not result in any significant difference of the OS and DFS, stage IV HNSCC patients with low CTGF showed significantly longer OS (P = 0.032) and DFS (P = 0.0107) than those with high CTGF. These differences in stage IV cases were also confirmed using multivariate analyses. These results suggest that low CTGF in stage IV HNSCC is an independent prognostic factor, despite with or without neoadjuvant therapy.

  8. Age at menopause and hormone replacement therapy as risk factors for head and neck and oesophageal cancer (Review).

    PubMed

    McCarthy, Caroline E; Field, John K; Marcus, Michael W

    2017-10-01

    There were ~986,000 cases of head and neck cancer (HNC) and oesophageal cancer diagnosed worldwide in 2012. The incidence of these types of cancer is much higher in males than females, although this disparity decreases in the elderly population, suggesting a role for hormones as a risk factor. This systematic review investigates the potential role of female hormones [age at menopause and use of hormone replacement therapy (HRT)] as risk factors for HNC/oesophageal squamous cell carcinoma (SCC). The electronic databases MEDLINE, Web of Science, EMBASE and Cochrane were searched. Only studies with at least 50 cases of HNC/oesophageal SCC, with data on age at menopause, smoking, alcohol, age and socioeconomic status or educational attainment, were included. The Newcastle Ottawa Scale was used for assessing risk of bias. Eight studies met the inclusion criteria (5 oesophageal SCC, 2 HNC and 1 combined oesophageal SCC and HNC). HRT was shown to reduce the risk of HNC (HR, 0.78; 95% CI, 0.61-0.99) in one study. Our results showed that earlier age at menopause is a risk factor for oesophageal SCC, with women entering menopause at <45 years having double the risk of those entering menopause at age >50 years. Similar, but less striking, results were observed for HNC. HRT was found to reduce the risk of HNC/oesophageal SCC, but the evidence is inconclusive. We, therefore, recommend that consideration should be given to collecting data on reproductive factors and exposure to HRT, as routine practice, in future epidemiological and clinical studies of these cancers. The concept of oestrogen deficiency as a risk for HNC/oesophageal SCC deserves further exploration in future laboratory and clinical studies.

  9. Investigation of Factors Affecting Body Temperature Changes During Routine Clinical Head Magnetic Resonance Imaging

    PubMed Central

    Kim, Myeong Seong

    2016-01-01

    Background Pulsed radiofrequency (RF) magnetic fields, required to produce magnetic resonance imaging (MRI) signals from tissue during the MRI procedure have been shown to heat tissues. Objectives To investigate the relationship between body temperature rise and the RF power deposited during routine clinical MRI procedures, and to determine the correlation between this effect and the body’s physiological response. Patients and Methods We investigated 69 patients from the Korean national cancer center to identify the main factors that contribute to an increase in body temperature (external factors and the body’s response) during a clinical brain MRI. A routine protocol sequence of MRI scans (1.5 T and 3.0 T) was performed. The patient’s tympanic temperature was recorded before and immediately after the MRI procedure and compared with changes in variables related to the body’s physiological response to heat. Results Our investigation of the physiological response to RF heating indicated a link between increasing age and body temperature. A higher increase in body temperature was observed in older patients after a 3.0-T MRI (r = 0.07, P = 0.29 for 1.5-T MRI; r = 0.45, P = 0.002 for 3.0-T MRI). The relationship between age and body heat was related to the heart rate (HR) and changes in HR during the MRI procedure; a higher RF power combined with a reduction in HR resulted in an increase in body temperature. Conclusion A higher magnetic field strength and a decrease in the HR resulted in an increase in body temperature during the MRI procedure. PMID:27895872

  10. Investigation of Factors Affecting Body Temperature Changes During Routine Clinical Head Magnetic Resonance Imaging.

    PubMed

    Kim, Myeong Seong

    2016-10-01

    Pulsed radiofrequency (RF) magnetic fields, required to produce magnetic resonance imaging (MRI) signals from tissue during the MRI procedure have been shown to heat tissues. To investigate the relationship between body temperature rise and the RF power deposited during routine clinical MRI procedures, and to determine the correlation between this effect and the body's physiological response. We investigated 69 patients from the Korean national cancer center to identify the main factors that contribute to an increase in body temperature (external factors and the body's response) during a clinical brain MRI. A routine protocol sequence of MRI scans (1.5 T and 3.0 T) was performed. The patient's tympanic temperature was recorded before and immediately after the MRI procedure and compared with changes in variables related to the body's physiological response to heat. Our investigation of the physiological response to RF heating indicated a link between increasing age and body temperature. A higher increase in body temperature was observed in older patients after a 3.0-T MRI (r = 0.07, P = 0.29 for 1.5-T MRI; r = 0.45, P = 0.002 for 3.0-T MRI). The relationship between age and body heat was related to the heart rate (HR) and changes in HR during the MRI procedure; a higher RF power combined with a reduction in HR resulted in an increase in body temperature. A higher magnetic field strength and a decrease in the HR resulted in an increase in body temperature during the MRI procedure.

  11. Review of scattering and extinction cross-sections, damping factors, and resonance frequencies of a spherical gas bubble.

    PubMed

    Ainslie, Michael A; Leighton, Timothy G

    2011-11-01

    Perhaps the most familiar concepts when discussing acoustic scattering by bubbles are the resonance frequency for bubble pulsation, the bubbles' damping, and their scattering and extinction cross-sections, all of which are used routinely in oceanography, sonochemistry, and biomedicine. The apparent simplicity of these concepts is illusory: there exist multiple, sometimes contradictory definitions for their components. This paper reviews expressions and definitions in the literature for acoustical cross-sections, resonance frequencies, and damping factors of a spherically pulsating gas bubble in an infinite liquid medium, deriving two expressions for "resonance frequency" that are compared and reconciled with two others from the reviewed literature. In order to prevent errors, care is needed by researchers when combining results from different publications that might have used internally correct but mutually inconsistent definitions. Expressions are presented for acoustical cross-sections associated with forced pulsations damped by liquid shear and (oft-neglected) bulk or dilatational viscosities, gas thermal diffusivity, and acoustic re-radiation. The concept of a dimensionless "damping coefficient" is unsuitable for radiation damping because different cross-sections would require different functional forms for this parameter. Instead, terms based on the ratio of bubble radius to acoustic wavelength are included explicitly in the cross-sections where needed.

  12. Determination of the scattering coefficient of biological tissue considering the wavelength and absorption dependence of the anisotropy factor

    NASA Astrophysics Data System (ADS)

    Fukutomi, Daichi; Ishii, Katsunori; Awazu, Kunio

    2016-04-01

    The anisotropy factor g, one of the optical properties of biological tissues, has a strong influence on the calculation of the scattering coefficient μ s in inverse Monte Carlo (iMC) simulations. It has been reported that g has the wavelength and absorption dependence; however, few attempts have been made to calculate μ s using g values by taking the wavelength and absorption dependence into account. In this study, the angular distributions of scattered light for biological tissue phantoms containing hemoglobin as a light absorber were measured by a goniometric optical setup at strongly (405 nm) and weakly (664 nm) absorbing wavelengths to obtain g. Subsequently, the optical properties were calculated with the measured values of g by integrating sphere measurements and an iMC simulation, and compared with the results obtained with a conventional g value of 0.9. The μ s values with measured g were overestimated at the strongly absorbing wavelength, but underestimated at the weakly absorbing wavelength if 0.9 was used in the iMC simulation.

  13. Determination of scattering coefficient considering wavelength and absorption dependence of anisotropy factor measured by polarized beam for biological tissues

    NASA Astrophysics Data System (ADS)

    Fukutomi, D.; Ishii, K.; Awazu, K.

    2015-12-01

    Anisotropy factor g, one of the optical properties of biological tissues, is the most important parameter to accurately determine scattering coefficient μs in the inverse Monte Carlo (iMC) simulation. It has been reported that g has wavelength and absorption dependence, however, there are few attempts in order to calculate μs of biological tissue considering the wavelength and absorption dependence of g. In this study, the scattering angular distributions of biological tissue phantoms were measured in order to determine g by using goniometric measurements with three polarization conditions at strongly and weakly absorbing wavelengths of hemoglobin. Then, optical properties, especially, μs were measured by integrating sphere measurements and iMC simulation in order to confirm the influence of measured g on optical properties in comparison of with general value of g (0.9) for soft biological tissue. Consequently, it was found that μs was overestimated at strongly absorbing wavelength, however, μs was underestimated at weakly absorbing wavelength if the g was not considered its wavelength and absorption dependence.

  14. The prevalence of food insecurity and associated factors among households with children in Head Start programs in Houston, Texas and Birmingham, Alabama

    USDA-ARS?s Scientific Manuscript database

    This study measured food security and hunger of households enrolled in Head Start in Houston, Texas, and Birmingham, Alabama and assessed factors that could affect food security. Interviewers collected data from primary caregivers on demographic characteristics, dietary intake, and the six-item US f...

  15. The distinctive profile of risk factors of nasopharyngeal carcinoma in comparison with other head and neck cancer types

    PubMed Central

    Abdulamir, AS; Hafidh, RR; Abdulmuhaimen, N; Abubakar, F; Abbas, KA

    2008-01-01

    Background Nasopharyngeal carcinoma (NPC) and other head and neck cancer (HNCA) types show a great epidemiological variation in different regions of the world. NPC has multifactorial etiology and many interacting risk factors are involved in NPC development mainly Epstein Barr virus (EBV). There is a need to scrutinize the complicated network of risk factors affecting NPC and how far they are different from that of other HNCA types. Methods 122 HNCA patients and 100 control subjects were studied in the region of the Middle East. Three types of HNCA were involved in our study, NPC, carcinoma of larynx (CL), and hypopharyngeal carcinoma (HPC). The risk factors studied were the level of EBV serum IgG and IgA antibodies measured by ELISA, age, sex, smoking, alcohol intake, histology, and family history of the disease. Results EBV serum level of IgG and IgA antibodies was higher in NPC than CL, HPC, and control groups (p < 0.01). NPC was associated with lymphoepithelioma (LE) tumors, males, regular alcohol intake, and regular smoking while CL and HPC were not (p < 0.05). CL and HPC were associated with SCC tumors (p < 0.05). Furthermore, NPC, unlike CL and HPC groups, was not affected by the positive family history of HNCA (p > 0.05). The serum levels of EBV IgG and IgA antibodies were higher in LE tumors, regular smokers, younger patients, and negative family history groups of NPC patients than SCC tumors, non-regular smokers, older patients and positive family history groups respectively (p < 0.05) while this was not found in the regular alcoholics (p > 0.05). Conclusion It was concluded that risk factors of NPC deviate much from that of other HNCA. EBV, smoking, alcohol intake, LE tumors, male patient, and age > 54 years were hot risk factors of NPC while SCC and positive family history of the disease were not. Earlier incidence, smoking, LE tumors, and negative family history of the disease in NPC patients were associated much clearly with EBV. It is proposed that

  16. Quasi-conformal shape of the BFKL kernel and impact factors for scattering of colourless particles

    NASA Astrophysics Data System (ADS)

    Fadin, V. S.; Fiore, R.; Grabovsky, A. V.; Papa, A.

    2011-07-01

    The NLO BFKL kernel in the Möbius representation is transformed to the quasi-conformal shape in theories containing fermions and scalars in arbitrary representations of the colour group. Corresponding transformations of impact factors of colourless particles are discussed.

  17. Evaluation of beam hardening and photon scatter by brass compensator for IMRT.

    PubMed

    Hashimoto, Shimpei; Karasawa, Katsuyuki; Fujita, Yukio; Miyashita, Hisayuki; Chang, Weishan; Kawachi, Toru; Katayose, Tetsurou; Kobayashi, Nao; Kunieda, Etsuo; Saitoh, Hidetoshi

    2012-11-01

    When a brass compensator is set in a treatment beam, beam hardening may take place. This variation of the energy spectrum may affect the accuracy of dose calculation by a treatment planning system and the results of dose measurement of brass compensator intensity modulated radiation therapy (IMRT). In addition, when X-rays pass the compensator, scattered photons are generated within the compensator. Scattered photons may affect the monitor unit (MU) calculation. In this study, to evaluate the variation of dose distribution by the compensator, dose distribution was measured and energy spectrum was simulated using the Monte Carlo method. To investigate the influence of beam hardening for dose measurement using an ionization chamber, the beam quality correction factor was determined. Moreover, to clarify the effect of scattered photons generated within the compensator for the MU calculation, the head scatter factor was measured and energy spectrum analyses were performed. As a result, when X-rays passed the brass compensator, beam hardening occurred and dose distribution was varied. The variation of dose distribution and energy spectrum was larger with decreasing field size. This means that energy spectrum should be reproduced correctly to obtain high accuracy of dose calculation for the compensator IMRT. On the other hand, the influence of beam hardening on k(Q) was insignificant. Furthermore, scattered photons were generated within the compensator, and scattered photons affect the head scatter factor. These results show that scattered photons must be taken into account for MU calculation for brass compensator IMRT.

  18. The Expression of Checkpoint and DNA Repair Genes in Head and Neck Cancer as Possible Predictive Factors.

    PubMed

    Rusz, Orsolya; Pál, Margit; Szilágyi, Éva; Rovó, László; Varga, Zoltán; Tomisa, Bernadett; Fábián, Gabriella; Kovács, Levente; Nagy, Olga; Mózes, Petra; Reisz, Zita; Tiszlavicz, László; Deák, Péter; Kahán, Zsuzsanna

    2017-04-01

    DNA damage response failure may influence the efficacy of DNA-damaging treatments. We determined the expression of 16 genes involved in distinct DNA damage response pathways, in association with the response to standard therapy. Twenty patients with locoregionally advanced, squamous cell head and neck carcinoma were enrolled. The treatment included induction chemotherapy (iChT) with docetaxel, cisplatin and 5-fluorouracil followed by concomitant chemoradiotherapy (ChRT) or radiotherapy (RT) alone. The volumetric metabolic therapeutic response was determined by [18F]FDG-PET/CT. In the tumor and matched normal tissues collected before treatment, the gene expressions were examined via the quantitative real-time polymerase chain reaction (qRT-PCR). The down-regulation of TP53 was apparently associated with a poor response to iChT, its up-regulation with complete regression in 2 cases. 7 cases with down-regulated REV1 expression showed complete regression after ChRT/RT, while 1 case with REV1 overexpression was resistant to RT. The overexpression of WRN was an independent predictor of tumor relapse. Our results suggest that an altered expression of REV1 predicts sensitivity to RT, while WRN overexpression is an unfavorable prognostic factor.

  19. Honokiol inhibits the growth of head and neck squamous cell carcinoma by targeting epidermal growth factor receptor.

    PubMed

    Singh, Tripti; Gupta, Nirzari A; Xu, Su; Prasad, Ram; Velu, Sadanandan E; Katiyar, Santosh K

    2015-08-28

    Here, we report the chemotherapeutic effect of honokiol, a phytochemical from Magnolia plant, on human head and neck squamous cell carcinoma (HNSCC). Treatment of HNSCC cell lines from different sub-sites, SCC-1 (oral cavity), SCC-5 (larynx), OSC-19 (tongue) and FaDu (pharynx) with honokiol inhibited their cell viability, which was associated with the: (i) induction of apoptosis, (ii) correction of dysregulatory cell cycle proteins of G0/G1 phase. Honokiol decreased the expression levels of epidermal growth factor receptor (EGFR), mTOR and their downstream signaling molecules. Treatment of FaDu and SCC-1 cell lines with rapamycin, an inhibitor of mTOR pathway, also reduced cell viability of HNSCC cells. Administration of honokiol by oral gavage (100 mg/kg body weight) significantly (P < 0.01-0.001) inhibited the growth of SCC-1 and FaDu xenografts in athymic nude mice, which was associated with: (i) inhibition of tumor cell proliferation, (ii) induction of apoptosis, (iii) reduced expressions of cyclins and Cdks, and (iv) inhibition of EGFR signaling pathway. Molecular docking analysis of honokiol in EGFR binding site indicated that the chemotherapeutic effect of honokiol against HNSCC is mediated through its firm binding with EGFR, which is better than that of gefitinib, a commonly used drug for HNSCC treatment.

  20. Honokiol inhibits the growth of head and neck squamous cell carcinoma by targeting epidermal growth factor receptor

    PubMed Central

    Singh, Tripti; Gupta, Nirzari A.; Xu, Su; Prasad, Ram; Velu, Sadanandan E.; Katiyar, Santosh K.

    2015-01-01

    Here, we report the chemotherapeutic effect of honokiol, a phytochemical from Magnolia plant, on human head and neck squamous cell carcinoma (HNSCC). Treatment of HNSCC cell lines from different sub-sites, SCC-1 (oral cavity), SCC-5 (larynx), OSC-19 (tongue) and FaDu (pharynx) with honokiol inhibited their cell viability, which was associated with the: (i) induction of apoptosis, (ii) correction of dysregulatory cell cycle proteins of G0/G1 phase. Honokiol decreased the expression levels of epidermal growth factor receptor (EGFR), mTOR and their downstream signaling molecules. Treatment of FaDu and SCC-1 cell lines with rapamycin, an inhibitor of mTOR pathway, also reduced cell viability of HNSCC cells. Administration of honokiol by oral gavage (100 mg/kg body weight) significantly (P < 0.01-0.001) inhibited the growth of SCC-1 and FaDu xenografts in athymic nude mice, which was associated with: (i) inhibition of tumor cell proliferation, (ii) induction of apoptosis, (iii) reduced expressions of cyclins and Cdks, and (iv) inhibition of EGFR signaling pathway. Molecular docking analysis of honokiol in EGFR binding site indicated that the chemotherapeutic effect of honokiol against HNSCC is mediated through its firm binding with EGFR, which is better than that of gefitinib, a commonly used drug for HNSCC treatment. PMID:26020804

  1. Connective tissue growth factor activates pluripotency genes and mesenchymal-epithelial transition in head and neck cancer cells.

    PubMed

    Chang, Cheng-Chi; Hsu, Wen-Hao; Wang, Chen-Chien; Chou, Chun-Hung; Kuo, Mark Yen-Ping; Lin, Been-Ren; Chen, Szu-Ta; Tai, Shyh-Kuan; Kuo, Min-Liang; Yang, Muh-Hwa

    2013-07-01

    The epithelial-mesenchymal transition (EMT) is a key mechanism in both embryonic development and cancer metastasis. The EMT introduces stem-like properties to cancer cells. However, during somatic cell reprogramming, mesenchymal-epithelial transition (MET), the reverse process of EMT, is a crucial step toward pluripotency. Connective tissue growth factor (CTGF) is a multifunctional secreted protein that acts as either an oncoprotein or a tumor suppressor among different cancers. Here, we show that in head and neck squamous cell carcinoma (HNSCC), CTGF promotes the MET and reduces invasiveness. Moreover, we found that CTGF enhances the stem-like properties of HNSCC cells and increases the expression of multiple pluripotency genes. Mechanistic studies showed that CTGF induces c-Jun expression through αvβ3 integrin and that c-Jun directly activates the transcription of the pluripotency genes NANOG, SOX2, and POU5F1. Knockdown of CTGF in TW2.6 cells was shown to reduce tumor formation and attenuate E-cadherin expression in xenotransplanted tumors. In HNSCC patient samples, CTGF expression was positively correlated with the levels of CDH1, NANOG, SOX2, and POU5F1. Coexpression of CTGF and the pluripotency genes was found to be associated with a worse prognosis. These findings are valuable in elucidating the interplay between epithelial plasticity and stem-like properties during cancer progression and provide useful information for developing a novel classification system and therapeutic strategies for HNSCC.

  2. Synovectomy of the elbow and radial head excision in rheumatoid arthritis. Predictive factors and long-term outcome.

    PubMed

    Gendi, N S; Axon, J M; Carr, A J; Pile, K D; Burge, P D; Mowat, A G

    1997-11-01

    We carried out a survival analysis of elbow synovectomy (ES) and excision of the radial head (RHE) performed on 171 rheumatoid elbows. The failure criteria were revision surgery (performed or desired) and/or the presence of significant or severe pain. The cumulative survival was 81% at one year which thereafter decreased by an average of 2.6% per year. The strongest predictor for success was a low preoperative range of supination-pronation when corresponding survival curves were compared. A low range of flexion-extension also predicted failure. Combining both factors gave better prediction (failure: 6.3% v 67%), but a long duration of elbow symptoms before surgery predicted failure (72%, p = 0.04). At review, there was a mean gain of 50 degrees in supination-pronation and 11 degrees in flexion-extension; both correlated with success. Failure correlated with recurrence of synovitis, elbow instability, ulnar neuropathy, poor general mobility and poor upper-limb function. The last was independently affected by the severity of RA in the ipsilateral shoulder. Our findings show that although the short-term result of ES and RHE in rheumatoid arthritis is good, the long-term outcome is poor except in a subgroup with more than 50% limitation of forearm rotation.

  3. Transforming growth factor β1 enhances stemness of head and neck squamous cell carcinoma cells through activation of Wnt signaling.

    PubMed

    Bae, Woo-Jin; Lee, Sang-Hyuk; Rho, Young-Soo; Koo, Bon-Seok; Lim, Young-Chang

    2016-12-01

    Transforming growth factor β (TGFβ) ligands, including TGFβ1, are multifunctional cytokines known as key regulators of cell growth, differentiation and inflammation. Dysregulated TGFβ signaling is common in numerous solid tumors, including head and neck squamous cell carcinoma (HNSCC). Previously, TGFβ ligands were also reported to be associated with an enhancement of stemness in glioma stem-like cells. However, their role in HNSCC cancer stem cells (CSCs) has not been explored. The present study demonstrated that TGFβ1 enriches the properties of HNSCC CSCs. TGFβ1 promoted sphere formation and increased stemness-associated gene expression (Oct4 and Sox2) of primary HNSCC CSCs. Additionally, the population of aldehyde dehydrogenase (ALDH)-positive cells was increased subsequent to exogenous treatment of cells with TGFβ1. In addition, following stimulation with TGFβ1, the cells exhibited more resistance to cisplatin and elevated expression of Twist, Snail and Slug. Mechanistically, TGFβ1 acts as an upstream stimulator of Wnt/β-catenin signaling. Collectively, the present findings provide insights toward the development of TGFβ1 signaling inhibition strategies for treating HNSCC CSCs.

  4. Nanoparticle Properties and Synthesis Effects on Surface-Enhanced Raman Scattering Enhancement Factor: An Introduction

    PubMed Central

    2015-01-01

    Raman spectroscopy has enabled researchers to map the specific chemical makeup of surfaces, solutions, and even cells. However, the inherent insensitivity of the technique makes it difficult to use and statistically complicated. When Raman active molecules are near gold or silver nanoparticles, the Raman intensity is significantly amplified. This phenomenon is referred to as surface-enhanced Raman spectroscopy (SERS). The extent of SERS enhancement is due to a variety of factors such as nanoparticle size, shape, material, and configuration. The choice of Raman reporters and protective coatings will also influence SERS enhancement. This review provides an introduction to how these factors influence signal enhancement and how to optimize them during synthesis of SERS nanoparticles. PMID:25884017

  5. Virtual light-by-light scattering and the g factor of a bound electron

    SciTech Connect

    Lee, R.N.; Milstein, A.I.; Terekhov, I.S.; Karshenboim, S.G.

    2005-05-15

    The contribution of the light-by-light diagram to the g factor of an electron and muon bound in a Coulomb field is obtained. For an electron in a ground state, our results are in good agreement with the results of other authors obtained numerically for large Z. For relatively small Z our results have essentially higher accuracy as compared to the previous ones. For muonic atoms, the contribution is obtained with a high accuracy in the whole region of Z.

  6. Numerical investigation of the enhancement factor of Raman scattering using plasmonic properties of gold nanorhomb arrays

    NASA Astrophysics Data System (ADS)

    Mehrvar, L.; Dizaji, Z. V.; Tavassoli, S. H.

    2017-03-01

    Plasmonic nanostructures with sharp tips like nanorhomb array provide strong electric field enhancement and consequently meaningful Raman signal enhancement. In this study, the near-field electromagnetic enhancement of the gold nanorhomb array formed by a new proposed approach has been investigated using the finite element method (FEM). Feasibility and ease of fabrication, which are very important in practical applications, are intended in this approach. This nanorhomb array is achieved by arranging holes tangentially together in a square lattice. In other words, nanorhombs are formed by transition from nanohole to nanoparticle array. Optimization of this structure for a surface-enhanced Raman spectroscopy (SERS) substrate is performed by sweeping through the geometric parameters. The most privileged nanorhomb array substrate with highest hot spot density and EM field enhancement is obtained by calculating the enhancement factor (EF) and normalized EF (EFN) for Raman lines of pyridine. Our simulations indicate that the localized surface plasmon resonance (LSPR) mode of such nanorhomb array leads to high electromagnetic enhancement factor (EMEF) and average surface integral of field enhancement factor (\\overlineEF), which are hundreds of times greater than the nanohole arrays. It is found that this LSPR mode is thickness-dependent besides being periodicity-dependent. Finally, accurate EF is calculated by considering local incident field enhancement in terms of the excitation process and local density of states (LDOS) enhancements on emission process and then the best structure with highest EF is obtained.

  7. RhoC Mediates Epidermal Growth Factor-Stimulated Migration and Invasion in Head and Neck Squamous Cell Carcinoma

    PubMed Central

    Tumur, Zohra; Katebzadeh, Shahbaz; Guerra, Carlos; Bhushan, Lokesh; Alkam, Tursun; Henson, Bradley S.

    2015-01-01

    Epidermal growth factor receptor (EGFR) is overexpressed in head and neck squamous cell carcinoma (HNSCC) where it has been shown to promote tumor cell invasion upon phosphorylation. One mechanism by which EGFR promotes tumor progression is by activating signal cascades that lead to loss of E-cadherin, a transmembrane glycoprotein of the cell-cell adherence junctions; however mediators of these signaling cascades are not fully understood. One such mediator, RhoC, is activated upon a number of external stimuli, such as epidermal growth factor (EGF), but its role as a mediator of EGF-stimulated migration and invasion has not been elucidated in HNSCC. In the present study, we investigate the role of RhoC as a mediator of EGF-stimulated migration and invasion in HNSCC. We show that upon EGF stimulation, EGFR and RhoC were strongly activated in HNSCC. This resulted in activation of the phosphatidylinositol 3-Kinase Akt pathway (PI3K-Akt), phosphorylation of GSK-3β at the Ser9 residue, and subsequent down regulation of E-cadherin cell surface expression resulting in increased tumor cell invasion. Knockdown of RhoC restored E-cadherin expression and inhibited EGF-stimulated migration and invasion. This is the first report in HNSCC demonstrating the role RhoC plays in mediating EGF-stimulated migration and invasion by down-regulating the PI3K-Akt pathway and E-cadherin expression. RhoC may serve as a treatment target for HNSCC. PMID:25622907

  8. Fibroblast Growth Factor Receptors Are Components of Autocrine Signaling Networks in Head and Neck Squamous Cell Carcinoma Cells

    PubMed Central

    Marshall, Marianne E.; Hinz, Trista K.; Kono, Scott A.; Singleton, Katherine R.; Bichon, Brady; Ware, Kathryn E.; Marek, Lindsay; Frederick, Barbara A.; Raben, David; Heasley, Lynn E.

    2011-01-01

    Purpose We previously reported that a fibroblast growth factor (FGF) receptor (FGFR) signaling pathway drives growth of lung cancer cell lines of squamous and large cell histologies. Herein, we explored FGFR dependency in cell lines derived from the tobacco-related malignancy, head and neck squamous cell carcinoma (HNSCC). Experimental Design FGF and FGFR mRNA and protein expression was assessed in nine HNSCC cell lines. Dependence on secreted FGF2 for cell growth was tested with FP-1039, an FGFR1-Fc fusion protein. FGFR and EGFR-dependence was defined by sensitivity to multiple inhibitors selective for FGFRs or EGFR. Results FGF2 was expressed in eight of the nine HNSCC cell lines examined. Also, FGFR2 and FGFR3 were frequently expressed while only two lines expressed FGFR1. FP-1039 inhibited growth of HNSCC cell lines expressing FGF2, identifying FGF2 as an autocrine growth factor. FGFR inhibitors selectively reduced in vitro growth and ERK signaling in three HNSCC cell lines while three distinct lines exhibited responsiveness to both EGFR and FGFR inhibitors. Combinations of these drugs yielded additive growth inhibition. Finally, three cell lines were highly sensitive to EGFR TKIs with no contribution from FGFR pathways. Conclusions FGFR signaling was dominant or co-dominant with EGFR in six HNSCC lines while three lines exhibited little or no role for FGFRs and were highly EGFR-dependent. Thus, the HNSCC cell lines can be divided into subsets defined by sensitivity to EGFR and FGFR-specific TKIs. FGFR inhibitors may represent novel therapeutics to deploy alone or in combination with EGFR inhibitors in HNSCC. PMID:21673064

  9. Positive Factors Influencing the Advancement of Women to the Role of Head Athletic Trainer in the National Collegiate Athletic Association Divisions II and III

    PubMed Central

    Mazerolle, Stephanie M.; Eason, Christianne M.

    2016-01-01

    Context:  Research suggests that women do not pursue leadership positions in athletic training due to a variety of reasons, including family challenges, organizational constraints, and reluctance to hold the position. The literature has been focused on the National Collegiate Athletic Association Division I setting, limiting our full understanding. Objective:  To examine factors that help women as they worked toward the position of head athletic trainer. Design:  Qualitative study. Setting:  Divisions II and III. Patients or Other Participants:  Seventy-seven women who were employed as head athletic trainers at the Division II or III level participated in our study. Participants were 38 ± 9 (range = 24−57) years old and had an average of 14 ± 8 (range = 1−33) years of athletic training experience. Data Collection and Analysis:  We conducted online interviews. Participants journaled their reflections to a series of open-ended questions pertaining to their experiences as head athletic trainers. Data were analyzed using a general inductive approach. Credibility was secured by peer review and researcher triangulation. Results:  Three organizational facilitators emerged from the data, workplace atmosphere, mentors, and past work experiences. These organizational factors were directly tied to aspects within the athletic trainer's employment setting that allowed her to enter the role. One individual-level facilitator was found: personal attributes that were described as helpful for women in transitioning to the role of the head athletic trainer. Participants discussed being leaders and persisting toward their career goals. Conclusions:  Women working in Divisions II and III experience similar facilitators to assuming the role of head athletic trainer as those working in the Division I setting. Divisions II and III were viewed as more favorable for women seeking the role of head athletic trainer, but like those in the role in the Division I setting

  10. Positive Factors Influencing the Advancement of Women to the Role of Head Athletic Trainer in the National Collegiate Athletic Association Divisions II and III.

    PubMed

    Mazerolle, Stephanie M; Eason, Christianne M

    2016-07-01

    Research suggests that women do not pursue leadership positions in athletic training due to a variety of reasons, including family challenges, organizational constraints, and reluctance to hold the position. The literature has been focused on the National Collegiate Athletic Association Division I setting, limiting our full understanding. To examine factors that help women as they worked toward the position of head athletic trainer. Qualitative study. Divisions II and III. Seventy-seven women who were employed as head athletic trainers at the Division II or III level participated in our study. Participants were 38 ± 9 (range = 24-57) years old and had an average of 14 ± 8 (range = 1-33) years of athletic training experience. We conducted online interviews. Participants journaled their reflections to a series of open-ended questions pertaining to their experiences as head athletic trainers. Data were analyzed using a general inductive approach. Credibility was secured by peer review and researcher triangulation. Three organizational facilitators emerged from the data, workplace atmosphere, mentors, and past work experiences. These organizational factors were directly tied to aspects within the athletic trainer's employment setting that allowed her to enter the role. One individual-level facilitator was found: personal attributes that were described as helpful for women in transitioning to the role of the head athletic trainer. Participants discussed being leaders and persisting toward their career goals. Women working in Divisions II and III experience similar facilitators to assuming the role of head athletic trainer as those working in the Division I setting. Divisions II and III were viewed as more favorable for women seeking the role of head athletic trainer, but like those in the role in the Division I setting, women must have leadership skills.

  11. Study of 19 MeV region of /sup 12/C by 180/sup 0/ electron scattering. [196 MeV, transverse form factors

    SciTech Connect

    Flanz, J. B.; Hicks, R. S.; Lindgren, R. A.; Peterson, G. A.; Fagg, L.; Sober, D.

    1980-01-01

    Back-angle, 180/sup 0/ electron scattering was used to measure the transverse form factors squared of transitions to the 19 MeV excitation region of /sup 12/C. Data were obtained in a momentum transfer range from 0.5 to 2.5 fm/sup -1/. The high resolution of the data enabled a decomposition of this complex into five distinct peaks. Analysis of the data includes a comparison with form factors predicted in a shell model calculation. In addition, an interpretation using isospin mixing of 4/sup -/ states, as suggested by recent pion scattering work, is discussed. The two interpretations are not entirely compatible.

  12. Scatter factor/hepatocyte growth factor and its receptor, the c-met tyrosine kinase, can mediate a signal exchange between mesenchyme and epithelia during mouse development

    PubMed Central

    1993-01-01

    Scatter factor/hepatocyte growth factor (SF/HGF) has potent motogenic, mitogenic, and morphogenetic activities on epithelial cells in vitro. The cell surface receptor for this factor was recently identified: it is the product of the c-met protooncogene, a receptor-type tyrosine kinase. We report here the novel and distinct expression patterns of SF/HGF and its receptor during mouse development, which was determined by a combination of in situ hybridization and RNase protection experiments. Predominantly, we detect transcripts of c-met in epithelial cells of various developing organs, whereas the ligand is expressed in distinct mesenchymal cells in close vicinity. In addition, transient SF/HGF and c-met expression is found at certain sites of muscle formation; transient expression of the c-met gene is also detected in developing motoneurons. SF/HGF and the c-met receptor might thus play multiple developmental roles, most notably, mediate a signal given by mesenchyme and received by epithelial. Mesenchymal signals are known to govern differentiation and morphogenesis of many epithelia, but the molecular nature of the signals has remained poorly understood. Therefore, the known biological activities of SF/HGF in vitro and the embryonal expression pattern reported here indicate that this mesenchymal factor can transmit morphogenetic signals in epithelial development and suggest a molecular mechanism for mesenchymal epithelial interactions. PMID:8408200

  13. X-ray Intermolecular Structure Factor ( XISF ): separation of intra- and intermolecular interactions from total X-ray scattering data

    SciTech Connect

    Mou, Q.; Benmore, C. J.; Yarger, J. L.

    2015-05-09

    XISFis a MATLAB program developed to separate intermolecular structure factors from total X-ray scattering structure factors for molecular liquids and amorphous solids. The program is built on a trust-region-reflective optimization routine with the r.m.s. deviations of atoms physically constrained.XISFhas been optimized for performance and can separate intermolecular structure factors of complex molecules.

  14. Experience of head and neck theatre staff and attitudes to human factors using an aviation-based analysis and classification system--a pilot survey.

    PubMed

    Konieczny, Katarzyna M; Seager, Leonie; Scott, Jim; Colbert, Serryth; Dale, Trevor; Brennan, Peter A

    2014-01-01

    The role that human factors have in contributing to air crashes is well known and is included as an essential part of training. Awareness of human factors in surgery is increasingly being recognised but surprisingly few papers have come from head and neck specialties. We circulated a questionnaire on human factors based on an aviation model to 140 head and neck medical and ancillary staff who work in operating theatres in 3 large UK hospitals. Most positive responses were found in the consultant group followed by trainee doctors and support staff. A significant difference was found in the subcategories of Unsafe Supervision (p=0.002) and Preconditions to Unsafe Acts (p=0.001). This work will help to identify multi-system deficiencies that can be corrected, and highlights aspects that may yield the greatest reduction in surgical errors.

  15. Constraints on hard spectator scattering and annihilation corrections in Bu,d → PV decays within QCD factorization

    NASA Astrophysics Data System (ADS)

    Sun, Junfeng; Chang, Qin; Hu, Xiaohui; Yang, Yueling

    2015-04-01

    In this paper, we investigate the contributions of hard spectator scattering and annihilation in B → PV decays within the QCD factorization framework. With available experimental data on B → πK* , ρK , πρ and Kϕ decays, comprehensive χ2 analyses of the parameters XA,Hi,f (ρA,Hi,f, ϕA,Hi,f) are performed, where XAf (XAi) and XH are used to parameterize the endpoint divergences of the (non)factorizable annihilation and hard spectator scattering amplitudes, respectively. Based on χ2 analyses, it is observed that (1) The topology-dependent parameterization scheme is feasible for B → PV decays; (2) At the current accuracy of experimental measurements and theoretical evaluations, XH = XAi is allowed by B → PV decays, but XH ≠ XAf at 68% C.L.; (3) With the simplification XH = XAi, parameters XAf and XAi should be treated individually. The above-described findings are very similar to those obtained from B → PP decays. Numerically, for B → PV decays, we obtain (ρA,Hi ,ϕA,Hi [ ° ]) = (2.87-1.95+0.66 , -145-21+14) and (ρAf, ϕAf [ ° ]) = (0.91-0.13+0.12 , -37-9+10) at 68% C.L. With the best-fit values, most of the theoretical results are in good agreement with the experimental data within errors. However, significant corrections to the color-suppressed tree amplitude α2 related to a large ρH result in the wrong sign for ACPdir (B- →π0K*-) compared with the most recent BABAR data, which presents a new obstacle in solving "ππ" and "πK" puzzles through α2. A crosscheck with measurements at Belle (or Belle II) and LHCb, which offer higher precision, is urgently expected to confirm or refute such possible mismatch.

  16. Light scattering by a rough surface of human skin. 1. The luminance factor of reflected light

    SciTech Connect

    Barun, V V; Ivanov, A P

    2013-08-31

    Based on the analytical solution of Maxwell's equations, we have studied the angular structure of the luminance factor of light reflected by the rough skin surface with large-scale relief elements, illuminated by a directed radiation beam incident at an arbitrary angle inside or outside the medium. The parameters of the surface inhomogeneities are typical of human skin. The calculated angular dependences are interpreted from the point of view of the angular distribution function of micro areas. The results obtained can be used for solving direct and inverse problems in biomedical optics, in particular for determining the depth of light penetration into a biological tissue, for studying the light action spectra on tissue chromophores under the in vivo conditions, for developing diagnostic methods of structural and biophysical parameters of a medium, and for optimising the mechanisms of interaction of light with biological tissues under their noninvasive irradiation through skin. (biomedical optics)

  17. Light scattering by a rough surface of human skin. 1. The luminance factor of reflected light

    NASA Astrophysics Data System (ADS)

    Barun, V. V.; Ivanov, A. P.

    2013-08-01

    Based on the analytical solution of Maxwell's equations, we have studied the angular structure of the luminance factor of light reflected by the rough skin surface with large-scale relief elements, illuminated by a directed radiation beam incident at an arbitrary angle inside or outside the medium. The parameters of the surface inhomogeneities are typical of human skin. The calculated angular dependences are interpreted from the point of view of the angular distribution function of micro areas. The results obtained can be used for solving direct and inverse problems in biomedical optics, in particular for determining the depth of light penetration into a biological tissue, for studying the light action spectra on tissue chromophores under the in vivo conditions, for developing diagnostic methods of structural and biophysical parameters of a medium, and for optimising the mechanisms of interaction of light with biological tissues under their noninvasive irradiation through skin.

  18. Cross sections and partial kerma factors for elastic and inelastic neutron scattering from nitrogen, oxygen and calcium at En = 21.6 MeV.

    PubMed

    Olsson, N; Ramström, E; Trostell, B

    1990-09-01

    The Studsvik high-resolution, low-background time-of-flight facility has been used to measure differential neutron scattering cross sections for nitrogen, oxygen and calcium at a neutron energy of 21.6 MeV. Angular distributions in the range 10 degrees-160 degrees have been measured for both elastic and inelastic scattering from some low-lying levels in the three nuclei. Angle-integrated cross sections have been determined by fitting Legendre polynomial expansions to the differential data. Partial kerma factors for elastic and inelastic scattering have been deduced from these fits. Analyses in terms of the spherical optical model and the distorted-wave Born approximation have provided information on potential parameters and deformations, which have been used to calculate cross sections and partial kerma factors. Comparisons have been made with other recent data sets and model predictions, as well as with the evaluated neutron data file ENDF/B-V.

  19. Critical assessment of enhancement factor measurements in surface-enhanced Raman scattering on different substrates.

    PubMed

    Rodrigues, Daniel C; de Souza, Michele L; Souza, Klester S; dos Santos, Diego P; Andrade, Gustavo F S; Temperini, Marcia L A

    2015-09-07

    The SERS enhancement factor (SERS-EF) is one of the most important parameters that characterizes the ability of a given substrate to enhance the Raman signal for SERS applications. The comparison of SERS intensities and SERS-EF values across different substrates is a common practice to unravel the performance of a given substrate. In this study, it is shown that such a comparison may lack significance if we compare substrates of very distinct nature and optical properties. It is specifically shown that the SERS-EF values for static substrates (e.g. immobilized metallic nanostructures) cannot be compared to those of dynamic ones (e.g. colloidal metal nanoparticle solutions), and that the optical properties for the latter show strong dependence on the metal-molecule interaction dynamics. The most representative experimental results concerning the dynamic substrates have been supported by generalized Mie theory simulations, which are tools used to describe the substrate complexity and the microscopic information not usually taken into account.

  20. Head erosion with emittance growth in PWFA

    SciTech Connect

    Li, S. Z.; Adli, E.; England, R. J.; Frederico, J.; Gessner, S. J.; Hogan, M. J.; Litos, M. D.; Walz, D. R.; Muggli, P.; An, W.; Clayton, C. E.; Joshi, C.; Lu, W.; Marsh, K. A.; Mori, W.; Vafaei, N.

    2012-12-21

    Head erosion is one of the limiting factors in plasma wakefield acceleration (PWFA). We present a study of head erosion with emittance growth in field-ionized plasma from the PWFA experiments performed at the FACET user facility at SLAC. At FACET, a 20.3 GeV bunch with 1.8 Multiplication-Sign 10{sup 10} electrons is optimized in beam transverse size and combined with a high density lithium plasma for beam-driven plasma wakefield acceleration experiments. A target foil is inserted upstream of the plasma source to increase the bunch emittance through multiple scattering. Its effect on beamplasma interaction is observed with an energy spectrometer after a vertical bend magnet. Results from the first experiments show that increasing the emittance has suppressed vapor field-ionization and plasma wakefields excitation. Plans for the future are presented.

  1. Head lice

    PubMed Central

    2015-01-01

    Introduction Head louse infection is diagnosed by finding live lice, as eggs take 7 days to hatch (but a few may take longer, up to 13 days) and may appear viable for weeks after death of the egg. Infestation may be more likely in school children, with risks increased in children with more siblings or of lower socioeconomic group. Factors such as longer hair make diagnosis and treatment more difficult. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical question: What are the effects of physically acting treatments for head lice? We searched: Medline, Embase, The Cochrane Library, and other important databases up to March 2014 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found six studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review, we present information relating to the effectiveness and safety of the following interventions: 1,2-octanediol, dimeticone, herbal and essential oils, and isopropyl myristate. PMID:25587918

  2. A Community-Based Oral Health Intervention in Navajo Nation Head Start: Participation Factors and Contextual Challenges

    PubMed Central

    Bryant, Lucinda L.; Quissell, David O.; Braun, Patricia A.; Henderson, William G.; Johs, Nikolas; George, Carmen; Smith, Vong; Toledo, Nikola; Thomas, Jacob; Albino, Judith E.

    2015-01-01

    Successful interventions require consistent participation by intended recipients. We utilized mixed methods to describe participation of 518 parent-child dyads enrolled in a randomized cluster trial of a 2-year oral health intervention for Head Start (HS) families across Navajo Nation delivered by native Community Oral Health Specialists (COHS). We quantitatively assessed factors that contributed to participation and qualitatively examined barriers and strategies. The intervention offered fluoride varnish (FV) and oral health promotion (OHP) activities for two cohorts (enrolled in 2011, N=286, or 2012, N=232) of children in the HS classrooms and OHP for parents outside the classroom. Child participation was good: FV: 79.7% (Cohort 1) and 85.3% (Cohort 2) received at least 3 of 4 applications; OHP: 74.5% (Cohort 1) and 78.4% (Cohort 2) attended at least 3 of 5 events. Parent participation was low: 10.5% (Cohort 1) and 29.8% (Cohort 2) attended at least 3 of 4 events. Analysis of survey data found significant effects on parent participation from fewer people in the household, Cohort 2 membership, greater external-locus of control, and a greater perception that barriers existed to following recommended oral health behaviors. Qualitative analysis of reports from native field staff, COHS, community members, and the research team identified barriers (e.g., geographic expanse, constraints of a research trial) and suggested strategies to improve parent participation (e.g., improve communication between COHS and parents/community). Many challenges to participation exist when conducting interventions in rural areas with underserved populations. Working with community partners to inform the development and delivery of interventions is critical. PMID:26467679

  3. A Community-Based Oral Health Intervention in Navajo Nation Head Start: Participation Factors and Contextual Challenges.

    PubMed

    Bryant, Lucinda L; Quissell, David O; Braun, Patricia A; Henderson, William G; Johs, Nikolas; George, Carmen; Smith, Vong; Toledo, Nikola; Thomas, Jacob; Albino, Judith E

    2016-04-01

    Successful interventions require consistent participation by intended recipients. We utilized mixed methods to describe participation of 518 parent-child dyads enrolled in a randomized cluster trial of a 2-year oral health intervention for Head Start (HS) families across Navajo Nation delivered by native Community Oral Health Specialists (COHS). We quantitatively assessed factors that contributed to participation and qualitatively examined barriers and strategies. The intervention offered fluoride varnish (FV) and oral health promotion (OHP) activities for two cohorts (enrolled in 2011, N = 286, or 2012, N = 232) of children in the HS classrooms and OHP for parents outside the classroom. Child participation was good: FV: 79.7 (Cohort 1) and 85.3 % (Cohort 2) received at least 3 of 4 applications; OHP: 74.5 (Cohort 1) and 78.4 % (Cohort 2) attended at least 3 of 5 events. Parent participation was low: 10.5 (Cohort 1) and 29.8 % (Cohort 2) attended at least three of four events. Analysis of survey data found significant effects on parent participation from fewer people in the household, Cohort 2 membership, greater external-locus of control, and a greater perception that barriers existed to following recommended oral health behaviors. Qualitative analysis of reports from native field staff, COHS, community members, and the research team identified barriers (e.g., geographic expanse, constraints of a research trial) and suggested strategies to improve parent participation (e.g., improve communication between COHS and parents/community). Many challenges to participation exist when conducting interventions in rural areas with underserved populations. Working with community partners to inform the development and delivery of interventions is critical.

  4. Clinical features and prognostic factors in patients with head and neck cancer: Results from a multicentric study.

    PubMed

    Leoncini, Emanuele; Vukovic, Vladimir; Cadoni, Gabriella; Pastorino, Roberta; Arzani, Dario; Bosetti, Cristina; Canova, Cristina; Garavello, Werner; La Vecchia, Carlo; Maule, Milena; Petrelli, Livia; Pira, Enrico; Polesel, Jerry; Richiardi, Lorenzo; Serraino, Diego; Simonato, Lorenzo; Ricciardi, Walter; Boccia, Stefania

    2015-06-01

    The purpose of this study is to evaluate whether demographics, lifestyle habits, clinical data and alcohol dehydrogenase polymorphisms rs1229984 and rs1573496 associated with first primary head and neck (HNC) are associated with overall survival, recurrence, and second primary cancer (SPC). We conducted a follow-up study in five centres including 801 cases. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for overall survival, recurrence and SPC. Five-years overall survival was 62% for HNC cases, 55% for oral cavity, 53% for oropharynx, 41% for hypopharynx, and 71% for larynx. Predictors of survival were older ages (HR=1.18 for 5 years increase; CI: 1.07-1.30), higher tumour stage (HR=4.16; CI: 2.49-6.96), and high alcohol consumption (HR=3.93; CI: 1.79-8.63). A combined therapy (HR=3.29; CI: 1.18-9.13) was associated with a worst prognosis for oral cavity cancer. The only predictor was higher tumour stage (HR=2.25; CI: 1.26-4.03) for recurrence, and duration of smoking (HR=1.91; CI: 1.00-3.68) for SPC. ADH1B rs1229984 polymorphism HRs for HNC and oesophageal cancer death and for alcohol related cancer death were 0.67 (95% CI: 0.42-1.08), and 0.64 (95% CI: 0.40-1.03), respectively. The survival expectation differs among HNC sites. Increasing age and stage, and high alcohol consumption were unfavourable predictors of HNC survival overall. Duration of tobacco consumption before the first primary tumour was a risk factor for SPC. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. IMC-C225, an anti-epidermal growth factor receptor monoclonal antibody, for treatment of head and neck cancer.

    PubMed

    Herbst, R S; Kim, E S; Harari, P M

    2001-07-01

    Squamous cell carcinoma (SCC) of the head and neck (H&N) remains a clinical challenge due to its high rate of locoregional disease recurrence. The importance of the epidermal growth factor receptor (EGFR) in the development and progression of many solid tumours (including SCC of the H&N) is well understood; increased expression is associated with enhanced tumour invasion, resistance to chemotherapy and decreased patient survival. Several approaches have been developed to achieve EGFR blockade as an anticancer treatment strategy, including an anti-EGFR monoclonal antibody (mAb), IMC-C225, which competitively binds to the extracellular receptor site to prevent binding by natural EGFR ligands (EGF and TGF-alpha). Preclinical studies evaluating this chimeric mAb in human cancer cell lines in vitro and human tumour xenografts in vivo have demonstrated its potent antitumour activity. The clinical efficacy of IMC-C225 appears to involve multiple anticancer mechanisms, including inhibition of cell cycle progression, induction of apoptosis, anti-angiogenesis, inhibition of metastasis and its ability to enhance the response to chemotherapy and radiation therapy. Phase I studies of IMC-C225 combined with chemotherapy or radiation for SCC of the H&N demonstrate excellent response rates in patients with recurrent or refractory disease. Phase II and III trials examining the efficacy and safety of these combinations are currently underway. To date, IMC-C225 has been well-tolerated, with skin rashes and allergic reactions being the most clinically important adverse events reported. IMC-C225 displays dose-dependent elimination characteristics and a half-life of approximately 7 days. Current recommendations for dosing include a 400 mg/m2 loading dose, followed by weekly infusions of 250 mg/m2.

  6. Molecular phenotype predicts sensitivity of squamous cell carcinoma of the head and neck to epidermal growth factor receptor inhibition.

    PubMed

    Young, Natalie R; Liu, Jing; Pierce, Carolyn; Wei, Tai-Fen; Grushko, Tatyana; Olopade, Olufunmilayo I; Liu, Wanqing; Shen, Christine; Seiwert, Tanguy Y; Cohen, Ezra E W

    2013-06-01

    Despite nearly universal expression of the wild-type epidermal growth factor receptor (EGFR) and reproducible activity of EGFR inhibitors in patients with squamous cell carcinoma of the head and neck (SCCHN), the majority of patients will not have objective responses. The mechanisms of this intrinsic resistance are not well established. We hypothesized that sensitivity to EGFR inhibitors can be predicted based on the inhibitors' effects on downstream signaling. Cell viability assays were used to assess sensitivity to the EGFR inhibitor gefitinib (ZD1839) in 8 SCCHN cell lines. Fluorescence in-situ hybridization showed the two most sensitive lines to be highly gene-amplified for EGFR. Western blotting confirmed that phosphoEGFR was inhibited at low concentrations of gefitinib in all lines tested. Phosphorylation of downstream signaling protein AKT was inhibited in sensitive lines while inhibition of phosphoERK displayed no relationship to gefitinib efficacy. Phosphatase and tensin homolog (PTEN) expression was evident in all cell lines. Activating PIK3CA mutations were found in two resistant cell lines where pAKT was not inhibited by gefitinib. In resistant cell lines harboring PIK3CA mutations, a PI3K inhibitor, LY294002, or AKT siRNA reduced cell viability with an additive effect demonstrated in combination with gefitinib. Additionally, LY294002 alone and in combination with gefitinib, was effective at treating PIK3CA mutated tumors xenografted into nude mice. Taken together this suggests that constitutively active AKT is a mechanism of intrinsic gefitinib resistance in SCCHN. This resistance can be overcome through targeting of the PI3K/AKT pathway in combination with EGFR inhibition.

  7. The opioid growth factor (OGF)-OGF receptor axis uses the p16 pathway to inhibit head and neck cancer.

    PubMed

    Cheng, Fan; Zagon, Ian S; Verderame, Michael F; McLaughlin, Patricia J

    2007-11-01

    Head and neck squamous cell carcinoma (HNSCC) represents 5.5% of malignancies worldwide, with approximately 30,000 new cases and approximately 11,000 deaths reported in the United States annually. The opioid growth factor (OGF; [Met(5)]-enkephalin) and the OGF receptor (OGFr) form an endogenous growth regulating system; the OGF-OGFr axis influences the G(0)-G(1) phase of the cell cycle in HNSCC. Cells treated with small interfering RNA (siRNA) for OGFr no longer responded to the growth inhibitory effects of OGF or the growth stimulatory effects of naltrexone, indicating that these activities are entirely mediated by OGFr. In this investigation, we examined the precise target of OGF in the cell cycle. Using SCC-1 cells, OGF decreased the phosphorylation of retinoblastoma protein. This change was correlated with reduced Cdk4, but not Cdk2, kinase activity. OGF treatment increased cyclin-dependent kinase inhibitor p16 protein expression. Importantly, p16 complexed with Cdk4 was increased by OGF treatment at all time points, consistent with the hypothesis that OGF mediated growth inhibition through p16. Blockade of OGF-OGFr interactions with naloxone abolished the increased expression of p16 protein by OGF. Inhibition of p16 (INK4a) activation by p16-specific siRNA blocked OGF's repressive action on proliferation of SCC-1, CAL-27, and SCC-4 HNSCC cells. These data are the first to reveal that the target of cell proliferative inhibitory action of OGF in human HNSCC is a cyclin-dependent kinase inhibitory pathway, and this may be useful in the diagnosis and treatment of HNSCC.

  8. Modulation of the opioid growth factor ([Met(5)]-enkephalin)-opioid growth factor receptor axis: novel therapies for squamous cell carcinoma of the head and neck.

    PubMed

    McLaughlin, Patricia J; Stucki, Jaimon K; Zagon, Ian S

    2012-04-01

    The opioid growth factor (OGF)-OGF receptor (OGFr) axis is a constitutively expressed biologic pathway regulating cell proliferation of squamous cell carcinoma of the head and neck (SCCHN). This study investigated modulation of the OGF-OGFr system by (1) exogenous OGF, (2) upregulation of OGFr using imiquimod, or (3) intermittent opioid receptor blockade with a low dose of naltrexone on progression of established SCCHN. Nude mice with visible human SCCHN SCC-1 tumors received (1) OGF or low-dose naltrexone either 1, 3, or 7 times/week or (2) imiquimod 1 or 3 times/week. Tumor growth and DNA synthesis were monitored. OGF and low-dose naltrexone increased the latency from visible to measurable tumors up to 1.6-fold. OGF, low-dose naltrexone, and imiquimod treatment markedly reduced tumor volume and weight, and decreased DNA synthesis in tumors. Modulation of the native OGF-OGFr regulatory network in SCCHN represents a novel nontoxic and highly efficacious approach for treatment of SCCHN. Copyright © 2011 Wiley Periodicals, Inc.

  9. Heads Up

    MedlinePlus

    ... Us HEADS UP Apps Reshaping the Culture Around Concussion in Sports Get HEADS UP on Your Web Site Concussion ... fit, and maintain the right helmet for specific sports. Concussion Laws Learn about Return to Play and other ...

  10. Head MRI

    MedlinePlus

    ... the head; MRI - cranial; NMR - cranial; Cranial MRI; Brain MRI; MRI - brain; MRI - head ... the test, tell your provider if you have: Brain aneurysm clips An artificial heart valves Heart defibrillator ...

  11. Rayleigh Scattering.

    ERIC Educational Resources Information Center

    Young, Andrew T.

    1982-01-01

    The correct usage of such terminology as "Rayleigh scattering,""Rayleigh lines,""Raman lines," and "Tyndall scattering" is resolved during an historical excursion through the physics of light-scattering by gas molecules. (Author/JN)

  12. Rayleigh Scattering.

    ERIC Educational Resources Information Center

    Young, Andrew T.

    1982-01-01

    The correct usage of such terminology as "Rayleigh scattering,""Rayleigh lines,""Raman lines," and "Tyndall scattering" is resolved during an historical excursion through the physics of light-scattering by gas molecules. (Author/JN)

  13. Head lice.

    PubMed

    Frankowski, Barbara L; Weiner, Leonard B

    2002-09-01

    Head lice infestation is associated with little morbidity but causes a high level of anxiety among parents of school-aged children. This statement attempts to clarify issues of diagnosis and treatment of head lice and makes recommendations for dealing with head lice in the school setting.

  14. Identification of independent risk factors for flap failure: A retrospective analysis of 1530 free flaps for breast, head and neck and extremity reconstruction.

    PubMed

    Las, David E; de Jong, Tim; Zuidam, J Michiel; Verweij, Norbert M; Hovius, Steven E R; Mureau, Marc A M

    2016-07-01

    Reconstructive microsurgery is a powerful method of treating various complex defects. However, flap loss remains a possibility, leading to additional surgery, hospitalisation and costs. Consequently, it is important to know which factors lead to an increased risk of flap failure, so that measures can be undertaken to reduce this risk. Therefore, we analysed our results over a 20-year period to identify risk factors for flap failure after breast, head and neck and extremity reconstruction. The medical files of all patients treated between 1992 and 2012 were reviewed. Patient characteristics, surgical data and post-operative complications were scored, and independent risk factors for flap loss were identified. Reconstruction with a total of 1530 free flaps was performed in 1247 patients. Partial and total flap loss occurred in 5.5% and 4.4% of all free flaps, respectively. In all flaps, signs of compromised flap circulation were a risk factor for flap failure. More specifically, the risk factors for flap failure in breast reconstruction were previous radiotherapy, venous anastomosis revision, gluteal artery perforator (GAP) flap choice and post-operative bleeding. In head and neck reconstruction, pulmonary co-morbidity and anastomosis to the lingual vein or superficial temporal artery were risk factors, whereas a radial forearm flap reduced the risk. In extremity reconstruction, diabetes, prolonged anaesthesia time and post-operative wound infection were risk factors. Independent pre-, intra- and post-operative risk factors for flap failure after microvascular breast, head and neck and extremity reconstruction were identified. These results may be used to improve patient counselling and to adjust treatment algorithms to further reduce the chance of flap failure.

  15. [Effects of promoting blood circulation to remove meridian obstruction combined with medicinal guides on related osteogenesis factors in rabbits with femoral head necrosis].

    PubMed

    Wang, Rong-tian; Kong, Xiang-ying; Tian, Neng; Lin, Na; Chen, Wei-heng

    2013-07-01

    To observe effects of blood circulation promoting compounds combined with medicinal guides on content of bone glaprotein (BGP), bone morphogenetic protein-2 (BPM-2) and expression of BMP-2 mRNA in rabbits with femoral head necrosis, and explore its mechanism. Ninety-eight healthy Spragur-Dawley male rabbits were collected and weighted 2.2 to 2.8 kg. Eighty-four rabbits were built femoral head necrosis model by freezing left femoral head in liquid nitrogen, then randomly divided into 6 groups, 14 in each group. The 6 groups included model group,promoting blood circulation to remove meridian obstruction group,promoting blood circulation to remove meridian obstruction combined with achyranthes bidentata group,radix angelicae pubescentis, asarum group, and platycodon grandiflorum group,other 14 rabbits were sham operation group. While drug groups were administrated corresponding Chinese herb after molding,model group and shamp operation group were given saline. Recombinant human granulocyte-colony stimulating factor ( 30 microg x kg(-1) x d(-1))were injected into all rabbits for 7 days. Samples were taken on the second and fourth week,the content of BGP and BMP-2 were detected by enzyme-linked immunosorbent assay (ELSA) and radioimmunoassay (RIA), histopathological changes of left femoral head were observed by Hematoxylin and Eeosin staining (HE), and expression of BMP-2 mRNA were tested by fluorescence in situ hybridization. Compared with sham operation group, the rate of empty lacunae femoral head were obviously increased in model group, and the content of BGP were increased on the second week, and BMP-2 and BMP-2 mRNA were decreased on the fourth week. Compared with model group, the content of BGP, BMP-2 and BMP-2 mRNA were higher both of the second and fourth week in promoting blood circulation to remove meridian obstruction group. The rate of empty la- cunae femoral head were lower in achyranthes bidentata group, BGP, BMP-2 and BMP-2 mRNA were higher on the fourth

  16. Rapid growth of invasive metastatic melanoma in carcinogen-treated hepatocyte growth factor/scatter factor-transgenic mice carrying an oncogenic CDK4 mutation.

    PubMed

    Tormo, Damia; Ferrer, Aleix; Gaffal, Evelyn; Wenzel, Jörg; Basner-Tschakarjan, Etiena; Steitz, Julia; Heukamp, Lukas C; Gütgemann, Ines; Buettner, Reinhard; Malumbres, Marcos; Barbacid, Mariano; Merlino, Glenn; Tüting, Thomas

    2006-08-01

    Currently, novel mouse models of melanoma are being generated that recapitulate the histopathology and molecular pathogenesis observed in human disease. Impaired cell-cycle control, which is a hallmark of both familial and sporadic melanoma, promotes slowly growing carcinogen-induced melanomas in the skin of mice carrying a mutated cyclin-dependent kinase 4 (CDK4(R24C)). Deregulated receptor tyrosine kinase signaling, which is another important feature of human melanoma, leads to spontaneous development of metastatic melanoma after a long latency period in mice overexpressing hepatocyte growth factor/scatter factor (HGF/SF mice). Here we report that treatment with 7,12-dimethylbenz[a]anthracene and 12-O-tetradecanoylphorbol-13-acetate induced metastatic melanomas in all HGF/SF mice on the C57BL/6 background, which histologically resemble human melanoma. Importantly, mutant CDK4 dramatically increased the number and the growth kinetics of carcinogen-induced primary melanomas in the skin and promoted the growth of spontaneous metastases in lymph nodes and lungs in all HGF/SF mice within the first 3 months of life. Apart from very few skin papillomas, we did not observe tumors of other histology in carcinogen-treated HGF/SF x CDK4(R24C) mice. This new experimental mouse model can now be exploited to study further the biology of melanoma and evaluate new treatment modalities.

  17. Vascular endothelial growth factor/bone morphogenetic protein-2 bone marrow combined modification of the mesenchymal stem cells to repair the avascular necrosis of the femoral head

    PubMed Central

    Ma, Xiao-Wei; Cui, Da-Ping; Zhao, De-Wei

    2015-01-01

    Vascular endothelial cell growth factor (VEGF) combined with bone morphogenetic protein (BMP) was used to repair avascular necrosis of the femoral head, which can maintain the osteogenic phenotype of seed cells, and effectively secrete VEGF and BMP-2, and effectively promote blood vessel regeneration and contribute to formation and revascularization of tissue engineered bone tissues. To observe the therapeutic effect on the treatment of avascular necrosis of the femoral head by using bone marrow mesenchymal stem cells (BMSCs) modified by VEGF-165 and BMP-2 in vitro. The models were avascular necrosis of femoral head of rabbits on right leg. There groups were single core decompression group, core decompression + BMSCs group, core decompression + VEGF-165/BMP-2 transfect BMSCs group. Necrotic bone was cleared out under arthroscope. Arthroscopic observation demonstrated that necrotic bone was cleared out in each group, and fresh blood flowed out. Histomorphology determination showed that blood vessel number and new bone area in the repair region were significantly greater at various time points following transplantation in the core decompression + VEGF-165/BMP-2 transfect BMSCs group compared with single core decompression group and core decompression + BMSCs group (P < 0.05). These suggested that VEGF-165/BMP-2 gene transfection strengthened osteogenic effects of BMSCs, elevated number and quality of new bones and accelerated the repair of osteonecrosis of the femoral head. PMID:26629044

  18. Field calibration of multi-scattering correction factor for aethalometer aerosol absorption coefficient during CAPMEX Campaign, 2008

    NASA Astrophysics Data System (ADS)

    Kim, J. H.; Kim, S. W.; Yoon, S. C.; Park, R.; Ogren, J. A.

    2014-12-01

    Filter-based instrument, such as aethalometer, is being widely used to measure equivalent black carbon(EBC) mass concentration and aerosol absorption coefficient(AAC). However, many other previous studies have poited that AAC and its aerosol absorption angstrom exponent(AAE) are strongly affected by the multi-scattering correction factor(C) when we retrieve AAC from aethalometer EBC mass concentration measurement(Weingartner et al., 2003; Arnott et al., 2005; Schmid et al., 2006; Coen et al., 2010). We determined the C value using the method given in Weingartner et al. (2003) by comparing 7-wavelngth aethalometer (AE-31, Magee sci.) to 3-wavelength Photo-Acoustic Soot Spectrometer (PASS-3, DMT) at Gosan climate observatory, Korea(GCO) during Cheju ABC plume-asian monsoon experiment(CAPMEX) campaign(August and September, 2008). In this study, C was estimated to be 4.04 ± 1.68 at 532 nm and AAC retrieved with this value was decreased as approximately 100% as than that retrieved with soot case value from Weingartner et al (2003). We compared the AAC determined from aethalomter measurements to that from collocated Continuous Light Absorption Photometer (CLAP) measurements from January 2012 to December 2013 at GCO and found good agreement in both AAC and AAE. This result suggests the determination of site-specific C is crucially needed when we calculate AAC from aethalometer measurements.

  19. Weak charge form factor and radius of 208Pb through parity violation in electron scattering

    SciTech Connect

    Horowitz, C. J.; Ahmed, Z.; Jen, C. -M.; Rakhman, A.; Souder, P. A.; Dalton, M. M.; Liyanage, N.; Paschke, K. D.; Saenboonruang, K.; Silwal, R.; Franklin, G. B.; Friend, M.; Quinn, B.; Kumar, K. S.; McNulty, D.; Mercado, L.; Riordan, S.; Wexler, J.; Michaels, R. W.; Urciuoli, G. M.

    2012-03-26

    We use distorted wave electron scattering calculations to extract the weak charge form factor FW($\\bar{q}$), the weak charge radius RW, and the point neutron radius Rn, of 208Pb from the PREX parity violating asymmetry measurement. The form factor is the Fourier transform of the weak charge density at the average momentum transfer $\\bar{q}$ = 0.475 fm-1. We find FW($\\bar{q}$) = 0.204 ± 0.028(exp) ± 0.001(model). We use the Helm model to infer the weak radius from FW($\\bar{q}$). We find RW = 5.826 ± 0.181(exp) ± 0.027(model) fm. Here the exp error includes PREX statistical and systematic errors, while the model error describes the uncertainty in RW from uncertainties in the surface thickness σ of the weak charge density. The weak radius is larger than the charge radius, implying a 'weak charge skin' where the surface region is relatively enriched in weak charges compared to (electromagnetic) charges. We extract the point neutron radius Rn = 5.751 ± 0.175 (exp) ± 0.026(model) ± 0.005(strange) fm, from RW. Here there is only a very small error (strange) from possible strange quark contributions. We find Rn to be slightly smaller than RW because of the nucleon's size. As a result, we find a neutron skin thickness of Rn-Rp = 0.302 ± 0.175 (exp) ± 0.026 (model) ± 0.005 (strange) fm, where Rp is the point proton radius.

  20. Use of Persistent Scatterer Interferometry to Assess Land Deformation in the Nile Delta and its Controlling Factors

    NASA Astrophysics Data System (ADS)

    Gebremichael, E.; Sultan, M.; Becker, R.; Emil, M.; Ahmed, M.; Chouinard, K.

    2015-12-01

    We applied Persistent scatterer interferometry (PSInSAR) to assess land deformation (subsidence and uplift) across the entire Nile delta and its surroundings and to identify possible causes of the observed deformation. For the purpose of the present study, 100 Envisat Advanced Synthetic Aperture Radar (ASAR; level 0) scenes that were acquired along four tracks and covering a time span of seven years (2004 to 2010) were used. The scenes extend from the Mediterranean coast in the north to Cairo city in the south. These scenes were focused using Repeat Orbit Interferometry PACkage (ROI_PAC) software and the subsequent PSI processing was done using the Stanford Method for Persistent Scatterers (StaMPS) method. A low coherence threshold (0.2) was used to decrease the impact of vegetation-related poor coherence and decorrelation of the scenes over the investigated time span. Subsidence was observed over: (1) the Demietta Nile River branch (3 to 14 mm/yr) where it intersects the Mediterranean coastline, (2) thick (~ 40 m) Holocene sediments in lake Manzala (up to 9 mm/yr), (3) reclaimed desert areas (west of Nile Delta; up to 12 mm/yr) of high groundwater extraction, (4) along parts of a previously proposed flexure line (up to 10 mm/yr), and (5) along the eastern sections of the Mediterranean coastline (up to 15.7 mm/yr). The city of Alexandria (underlain by carbonate platform) and the terminus of the Rosetta branch of the Nile River seem to experience almost no ground movement (mean subsidence of 0.28 mm/yr and 0.74 mm/yr respectively) while the cities of Ras Elbar and Port Said (underlain by thick Holocene sediment) exhibit the highest subsidence values (up to 14 mm/yr and 8.5 mm/yr respectively). The city of Cairo has also experienced subsidence in limited areas of up to 7.8 mm/yr. High spatial correlation was also observed between the subsiding areas and the Abu Madi incised valley; the largest gas field in the Nile Delta. Most of the area undergoing subsidence in the

  1. Evaluation of risk factors and development of acute kidney injury in aneurysmal subarachnoid hemorrhage, head injury, and severe sepsis/septic shock patients during ICU treatment.

    PubMed

    Kamar, Ceren; Ali, Achmet; Altun, Demet; Orhun, Günseli; Sabancı, Akın; Sencer, Altay; Akıncı, İbrahim Özkan

    2017-01-01

    There are few studies examining development of acute kidney injury (AKI) in the various types of patients in intensive care units (ICUs). Presently described is evaluation of risk factors and development of AKI in different groups of ICU patients. Present study was performed in 3 different ICUs. Development of AKI was measured using Acute Kidney Injury Network (AKIN) classification system. Total of 300 patients who were treated in trauma, neurosurgery, or general ICU departments (due to head injury, aneurysmal subarachnoid hemorrhage [aSAH], or severe sepsis/septic shock, respectively) were assessed for incidence, risk factors, and development of AKI. AKI did not develop in aSAH patients when evaluated based on serum creatinine level; however, it was observed in 5% of aSAH patients according to volume adjusted creatinine (VACr) level. AKI developed in 76% of sepsis group, and in 20% of head injury group, based on AKIN classification, according to both serum and VACr levels. Incidence of AKI was significantly higher in sepsis group (p<0.001). Only use of vasopressor was significantly related to AKI development in sepsis and head injury groups. Mortality rate was 8%, 22%, and 42% in aSAH, head injury, and sepsis groups, respectively. AKI development and vasopressor use were significantly related to mortality in sepsis group. Despite similar characteristics and risk factors, there were fewer instances of AKI in aSAH group. Hypertension or hydration therapy used to treat vasospasm and polyuria due to cerebral salt-wasting syndrome may prevent aSAH patients from developing AKI.

  2. Effective scatterer diameter estimates for broad scatterer size distributions.

    PubMed

    Nordberg, Eric P; Hall, Timothy J

    2015-01-01

    Acoustic form factors have been used to model the frequency dependence of acoustic scattering in phantoms and tissues. This work demonstrates that a broad range of scatterer sizes, individually well represented by Faran theory or a Gaussian form factor, is not accurately described by a single effective scatterer from either of these models. Contributions from a distribution of discrete scatterer sizes for two different form factor functions (Gaussian form factors and scattering functions from Faran's theory) were calculated and linearly combined. Composite form factors created from Gaussian distributions of scatterer sizes centered at 50 µm with standard deviations of up to σ = 40 µm were fit to each scattering model between 2 and 12 MHz. Scatterer distributions were generated using one of two assumptions: the number density of the scatterer diameter distribution was Gaussian distributed, or the volume fraction of each scatterer diameter in the distribution was Gaussian distributed. Each simulated form factor was fit to a single-diameter form factor model for Gaussian and exponential form factors. The mean-squared error (MSE) between the composite simulated data and the best-fit single-diameter model was smaller with an exponential form factor model, compared with a Gaussian model, for distributions with standard deviations larger than 30% of the centroid value. In addition, exponential models were shown to have better ability to distinguish between Faran scattering model-based distributions with varying center diameters than the Gaussian form factor model. The evidence suggests that when little is known about the scattering medium, an exponential scattering model provides a better first approximation to the scattering correlation function for a broad distribution of spherically symmetric scatterers than when a Gaussian form factor model is assumed.

  3. Analysis of time-dose factors in clinically positive neck nodes treated with irradiation alone in squamous cell carcinoma of the head and neck

    SciTech Connect

    Mendenhall, W.M.; Million, R.R.; Bova, F.J.

    1984-05-01

    This is a retrospective analysis of time-dose factors in 139 patients with 238 evaluable clinically positive lymph nodes treated with external beam radiation therapy alone to the primary lesion and neck for squamous cell carcinoma of the head and neck at the University of Florida from October 1964 through April 1980. Lymph node control was also influenced by dose, overall treament time, and fractionation schedule; these factors were interrelated and appeared to increase in importance as the size of the lymph node increased.

  4. Psychological Factors Associated with Head and Neck Cancer Treatment and Survivorship : Evidence and Opportunities for Behavioral Medicine

    ERIC Educational Resources Information Center

    Howren, M. Bryant; Christensen, Alan J.; Karnell, Lucy Hynds; Funk, Gerry F.

    2013-01-01

    Individuals diagnosed with head and neck cancer (HNC) not only face a potentially life-threatening diagnosis but must endure treatment that often results in significant, highly visible disfigurement and disruptions of essential functioning, such as deficits or complications in eating, swallowing, breathing, and speech. Each year, approximately…

  5. Psychological Factors Associated with Head and Neck Cancer Treatment and Survivorship : Evidence and Opportunities for Behavioral Medicine

    ERIC Educational Resources Information Center

    Howren, M. Bryant; Christensen, Alan J.; Karnell, Lucy Hynds; Funk, Gerry F.

    2013-01-01

    Individuals diagnosed with head and neck cancer (HNC) not only face a potentially life-threatening diagnosis but must endure treatment that often results in significant, highly visible disfigurement and disruptions of essential functioning, such as deficits or complications in eating, swallowing, breathing, and speech. Each year, approximately…

  6. Distinct Factors Associated with Head Start Mothers' Self-Report of Perceived Low Positive and High Negative Maternal Expressiveness

    ERIC Educational Resources Information Center

    Edwards, Nicole Megan

    2014-01-01

    Research Findings: There is growing acknowledgment of the need for parenting interventions to address early-onset behavior and emotional concerns. Favorable child outcomes have been linked to parents' responsiveness and positive expressiveness. Given the theoretical and empirical link between perceptions and actual behavior, Head Start mothers…

  7. Distinct Factors Associated with Head Start Mothers' Self-Report of Perceived Low Positive and High Negative Maternal Expressiveness

    ERIC Educational Resources Information Center

    Edwards, Nicole Megan

    2014-01-01

    Research Findings: There is growing acknowledgment of the need for parenting interventions to address early-onset behavior and emotional concerns. Favorable child outcomes have been linked to parents' responsiveness and positive expressiveness. Given the theoretical and empirical link between perceptions and actual behavior, Head Start mothers…

  8. Head injuries, heading, and the use of headgear in soccer.

    PubMed

    Niedfeldt, Mark W

    2011-01-01

    Soccer has more than 265 million players around the world and is the only contact sport with purposeful use of the head for controlling and advancing the ball. Head contact in soccer has the potential to cause acute traumatic brain injury including concussion or, potentially, a pattern of chronic brain injury. Although early retrospective research on the effects of soccer heading seemed to suggest that purposeful heading may contribute to long-term cognitive impairment, prospective controlled studies do not support this and, in fact, suggest that purposeful heading may not be a risk factor for cognitive impairment. Headgear has not been shown to be effective in reducing ball impact but may be helpful in reducing the force of non-ball-related impacts to the head. There are concerns that universal use of headgear may cause more aggressive heading and head challenges, leading to increased risk of injury.

  9. Small angle X-ray scattering data and structure factor fitting for the study of the quaternary structure of the spermidine N-acetyltransferase SpeG.

    PubMed

    Weigand, Steven; Filippova, Ekaterina V; Kiryukhina, Olga; Anderson, Wayne F

    2016-03-01

    Here we describe the treatment of the small-angle X-ray Scattering (SAXS) data used during SpeG quaternary structure study as part of the research article "Substrate induced allosteric change in the quaternary structure of the spermidine N-acetyltransferase SpeG" published in Journal of Molecular Biology [1]. These data were collected on two separate area detectors as separate dilution series of the SpeG and the SpeG with spermine samples along with data from their companion buffers. The data were radially integrated, corrected for incident beam variation, and scaled to absolute units. After subtraction of volume-fraction scaled buffer scattering and division by the SpeG concentration, multiple scattering curves free of an inter-molecular structure factor were derived from the dilution series. Rather than extrapolating to infinite dilution, the structure factor contribution was estimated by fitting to the full set of data provided by dividing the scattering curves of a dilution series by the curve from the most dilute sample in that series.

  10. Small angle X-ray scattering data and structure factor fitting for the study of the quaternary structure of the spermidine N-acetyltransferase SpeG

    PubMed Central

    Weigand, Steven; Filippova, Ekaterina V.; Kiryukhina, Olga; Anderson, Wayne F.

    2015-01-01

    Here we describe the treatment of the small-angle X-ray Scattering (SAXS) data used during SpeG quaternary structure study as part of the research article “Substrate induced allosteric change in the quaternary structure of the spermidine N-acetyltransferase SpeG” published in Journal of Molecular Biology [1]. These data were collected on two separate area detectors as separate dilution series of the SpeG and the SpeG with spermine samples along with data from their companion buffers. The data were radially integrated, corrected for incident beam variation, and scaled to absolute units. After subtraction of volume-fraction scaled buffer scattering and division by the SpeG concentration, multiple scattering curves free of an inter-molecular structure factor were derived from the dilution series. Rather than extrapolating to infinite dilution, the structure factor contribution was estimated by fitting to the full set of data provided by dividing the scattering curves of a dilution series by the curve from the most dilute sample in that series. PMID:26793756

  11. Modelling of the serine-proteinase fold by X-ray and neutron scattering and sedimentation analyses: occurrence of the fold in factor D of the complement system.

    PubMed Central

    Perkins, S J; Smith, K F; Kilpatrick, J M; Volanakis, J E; Sim, R B

    1993-01-01

    directly utilized to calculate sedimentation coefficients. X-ray scattering on factor D showed from its RG of 1.78 nm that this is monomeric and very similar in structure to beta-trypsin. The X-ray-scattering curve of factor D was readily modelled using the beta-trypsin crystal structure after allowance for sequence changes. The success of these modellings provides a basis for the constrained modelling of solution scattering data for the multidomain proteins of complement. PMID:8216242

  12. Effect of demographic and injury etiologic factors on intensive care unit mortality after severe head injury in a low middle income country.

    PubMed

    Jaja, Blessing N R; Eghwrudjakpor, Patrick O

    2014-01-01

    Low- and middle-income countries bear the mortality burden of head injury compared with high-income countries. Not much has been studied about predictors of poor outcome after head injury in these countries. This study describes and quantifies the effect of demographics and injury causative factors on mortality in a cohort managed in a Nigerian tertiary hospital intensive care. A retrospective study was undertaken of all patients admitted into intensive care with severe head injury at the University of Port Harcourt Teaching Hospital, Nigeria between 1 st January, 1997 and 31 st December, 2006. Logistic regression analysis was performed to examine the effect of age, gender and injury etiology on risk of intensive care unit (ICU) mortality. The number of ICU admission for severe head injury was 231 patients with a male to female ratio of 2.8:1. Patients' mean age and standard deviation was 31.2 ± 15.5 years. The mortality rate was 52.8%. Road traffic injury was the most common etiologic factor (84%). Logistic regression analysis indicated a 56% increase in the risk of ICU mortality between the ages of 21 and 40 years. The effect of age was found to be nonlinear (likelihood ratio P = 0.033). On multivariable analysis, patient's gender (odds ratio 1.07; 95% confidence interval: 0.56-1.97) and etiology of injury were not significantly associated with risk of mortality. Gender was not a modifier of the effect of age (P = 0.218). The study indicated a strong prognostic effect of age. Gender and etiology of injury had no effect on ICU mortality among study cohort.

  13. SU-E-T-463: Impact to Total Scatter Factors On the Calculated Dose Distribution in Radiosurgery

    SciTech Connect

    Garcia, O; Larraga-Gutierrez, J

    2015-06-15

    Purpose: To assess the impact of relative measurements: off axis ratios (OAR), tissue phantom ratios (TPR) and especially total scatter factor (TSF) on the calculated dose distribution in stereotactic radiosurgery with circular cones. Methods: Six detectors were employed to characterize circular collimated photon beams of 6 MV: three diodes (SFD, E, SRS), one ionization chamber (CC01) and two radiochromic films (EBT, EBT2). The relative measurements were incorporated in the treatment planning system (TPS) in order to compare and analyze the calculated dose distributions (DD). Each dose distribution was re-scaled by the TSF to observe its effect in the final dose distribution. The comparison was performed by using the gamma index. A Monte Carlo generated dosimetry was used as reference. Results: The results showed that in terms of relative dosimetry all the detectors have a good agreement within 2%, with the exception of the CC01 and EBT2 film. However, the analysis performed with the dose distributions re-scaled relative to the TSF for each detector showed that the impact it was not only to the isocenter dose. The dose to the PTV and normal tissue showed differences up to 13% depending of the dosimeter used for TSF measurements. Conclusion: With the exception of the CC01 ionization chamber and EBT2 radiochromic film, all the studied dosimeters were adequate for the measurement of OAR and TPR. However, attention must be put in the measurement of TSF. The use of the wrong detector does not only affect the isocenter dose, it may have an impact in the PTV and normal tissue dose.

  14. The Difference in Backscatter Factors of Diagnostic X-rays by the Difference in the Scattering Medium and in the Objective Dose.

    PubMed

    Kato, Hideki; Sakai, Keita; Uchiyama, Mizuki; Suzuki, Kentaro

    The diagnostic reference levels (DRLs) of the general X-ray radiography are defined by the absorbed dose of air at the entrance surface with backscattered radiation from a scattering medium. Generally, the entrance surface dose of the general X-ray radiography is calculated from measured air kerma of primary X-ray multiplied by a backscatter factor (BSF). However, the BSF data employed at present used water for scattering medium, and was calculated based on the water-absorbed dose by incident primary photons and backscattered photons from the scattering medium. In the calculation of air dose at the entrance surface defined in DRLs, there are no theoretical consistencies for using BSF based on water dose, and this may be a cause of calculation error. In this paper, we verified the difference in BSF by the difference in the scattering medium and by the difference in the objective dose by means of the Monte Carlo simulation. In this calculation, the scattering medium was set as water and the soft-tissue, and the objective dose was set as air dose, water dose, soft-tissue dose, and skin dose. The difference in BSF calculated by the respective combination was at most about 1.3% and was less than 1% in most cases. In conclusion, even if the entrance surface dose defined by DRLs of general X-ray radiography is calculated using BSF, which set both the scattering medium and the object substance of the absorbed dose as water, a so big error doesn't show.

  15. A study-level meta-analysis of efficacy data from head-to-head first-line trials of epidermal growth factor receptor inhibitors versus bevacizumab in patients with RAS wild-type metastatic colorectal cancer.

    PubMed

    Heinemann, Volker; Rivera, Fernando; O'Neil, Bert H; Stintzing, Sebastian; Koukakis, Reija; Terwey, Jan-Henrik; Douillard, Jean-Yves

    2016-11-01

    Head-to-head trials comparing first-line epidermal growth factor receptor inhibitor (EGFRI) versus vascular endothelial growth factor inhibitor (bevacizumab) therapy yielded differing results, and debate remains over optimal first-line therapy for patients with RAS wild-type (WT) metastatic colorectal cancer (mCRC). A PubMed search identified first-line mCRC trials comparing EGFRI plus chemotherapy versus bevacizumab plus chemotherapy; data were subsequently updated using recent congress presentations. This study-level meta-analysis estimated the overall survival (OS) treatment effect of first-line chemotherapy plus EGFRIs or bevacizumab in patients with RAS WT mCRC. Secondary end-points were progression-free survival (PFS), objective response rate (ORR), resection rate and safety. Early tumour shrinkage (ETS) of ≥20% at week 8 was an exploratory end-point. Three trials comprising data from 1096 patients with RAS WT mCRC were included. OS (hazard ratio [HR]: 0.80 [95% confidence interval: 0.68-0.93]), ORR (odds ratio [OR]: 0.57) and ETS (OR: 0.48) favoured EGFRIs plus chemotherapy versus bevacizumab plus chemotherapy. PFS (HR: 0.98) and resections (OR: 0.93) were similar between treatments. For patients with KRAS exon 2 WT/'other' RAS mutant mCRC the OS HR was 0.70. A safety meta-analysis was not possible due to a lack of data; in the individual studies, skin toxicities and hypomagnesaemia were more common with EGFRIs, nausea and hypertension were more common with bevacizumab. This meta-analysis supports a potential benefit for first-line EGFRI plus chemotherapy versus bevacizumab plus chemotherapy with respect to OS, ORR and ETS in patients with RAS WT mCRC. A patient-level meta-analysis is awaited. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. A Butterfly-Based Direct Integral-Equation Solver Using Hierarchical LU Factorization for Analyzing Scattering From Electrically Large Conducting Objects

    NASA Astrophysics Data System (ADS)

    Guo, Han; Liu, Yang; Hu, Jun; Michielssen, Eric

    2017-09-01

    A butterfly-based direct combined-field integral equation (CFIE) solver for analyzing scattering from electrically large, perfect electrically conducting objects is presented. The proposed solver leverages the butterfly scheme to compress blocks of the hierarchical LU-factorized discretized CFIE operator and uses randomized butterfly reconstruction schemes to expedite the factorization. The memory requirements and computational cost of the direct butterfly-CFIE solver scale as $O(N\\mathrm{log}^2N)$ and $O(N^{1.5}\\mathrm{log}N)$, respectively. These scaling estimates permit significant memory and CPU savings when compared to those realized by low-rank (LR) decomposition-based solvers. The efficacy and accuracy of the proposed solver are demonstrated through its application to the analysis of scattering from canonical and realistic objects involving up to 14 million unknowns.

  17. Risk factors for head and neck cancer in young adults: a pooled analysis in the INHANCE consortium

    PubMed Central

    Toporcov, Tatiana Natasha; Znaor, Ariana; Zhang, Zuo-Feng; Yu, Guo-Pei; Winn, Deborah M; Wei, Qingyi; Vilensky, Marta; Vaughan, Thomas; Thomson, Peter; Talamini, Renato; Szeszenia-Dabrowska, Neonila; Sturgis, Erich M; Smith, Elaine; Shangina, Oxana; Schwartz, Stephen M; Schantz, Stimson; Rudnai, Peter; Richiardi, Lorenzo; Ramroth, Heribert; Purdue, Mark P; Olshan, Andrew F; Eluf-Neto, José; Muscat, Joshua; Moyses, Raquel Ajub; Morgenstern, Hal; Menezes, Ana; McClean, Michael; Matsuo, Keitaro; Mates, Dana; Macfarlane, Tatiana V; Lissowska, Jolanta; Levi, Fabio; Lazarus, Philip; Vecchia, Carlo La; Lagiou, Pagona; Koifman, Sergio; Kjaerheim, Kristina; Kelsey, Karl; Holcatova, Ivana; Herrero, Rolando; Healy, Claire; Hayes, Richard B; Franceschi, Silvia; Fernandez, Leticia; Fabianova, Eleonora; Daudt, Alexander W; Curioni, Otávio Alberto; Maso, Luigino Dal; Curado, Maria Paula; Conway, David I; Chen, Chu; Castellsague, Xavier; Canova, Cristina; Cadoni, Gabriella; Brennan, Paul; Boccia, Stefania; Antunes, José Leopoldo Ferreira; Ahrens, Wolfgang; Agudo, Antonio; Boffetta, Paolo; Hashibe, Mia; Lee, Yuan-Chin Amy; Filho, Victor Wünsch

    2015-01-01

    Background: Increasing incidence of head and neck cancer (HNC) in young adults has been reported. We aimed to compare the role of major risk factors and family history of cancer in HNC in young adults and older patients. Methods: We pooled data from 25 case-control studies and conducted separate analyses for adults ≤45 years old (‘young adults’, 2010 cases and 4042 controls) and >45 years old (‘older adults’, 17 700 cases and 22 704 controls). Using logistic regression with studies treated as random effects, we estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs). Results: The young group of cases had a higher proportion of oral tongue cancer (16.0% in women; 11.0% in men) and unspecified oral cavity / oropharynx cancer (16.2%; 11.1%) and a lower proportion of larynx cancer (12.1%; 16.6%) than older adult cases. The proportions of never smokers or never drinkers among female cases were higher than among male cases in both age groups. Positive associations with HNC and duration or pack-years of smoking and drinking were similar across age groups. However, the attributable fractions (AFs) for smoking and drinking were lower in young when compared with older adults (AFs for smoking in young women, older women, young men and older men, respectively, = 19.9% (95% CI = 9.8%, 27.9%), 48.9% (46.6%, 50.8%), 46.2% (38.5%, 52.5%), 64.3% (62.2%, 66.4%); AFs for drinking = 5.3% (−11.2%, 18.0%), 20.0% (14.5%, 25.0%), 21.5% (5.0%, 34.9%) and 50.4% (46.1%, 54.3%). A family history of early-onset cancer was associated with HNC risk in the young [OR = 2.27 (95% CI = 1.26, 4.10)], but not in the older adults [OR = 1.10 (0.91, 1.31)]. The attributable fraction for family history of early-onset cancer was 23.2% (8.60% to 31.4%) in young compared with 2.20% (−2.41%, 5.80%) in older adults. Conclusions: Differences in HNC aetiology according to age group may exist. The lower AF of cigarette smoking and alcohol drinking in young

  18. A summary of the low angle x-ray atomic scattering factors which have been measured by the critical voltage effect in High Energy Electron Diffraction (HEED)

    SciTech Connect

    Fox, A.G.; Fisher, R.M.

    1987-08-01

    A tabulated summary of all the accurate (/approximately/0.1%) low-angle x-ray atomic scattering (form) factors which have been determined by the systematic critical voltage technique in HEED is presented. For low atomic number elements (Z/approx lt/40) the low angle form factors can be significantly different to best free atom values, and so the best band structure calculated and/or x-ray measured form factors consistent with the critical voltage measurements are also indicated. At intermediate atomic numbers Zapprox. =40..-->..50 only the very low-angle form factors appear to be different to the best free atom values, and even then only by a small amount. For heavy elements (Z/approx lt/70) the best free atom form factors appear to agree very closely with the critical voltage measured values and so, in this case, critical voltage measurements give very accurate measurements of Debye-Waller factors. 48 refs.

  19. Investigation of nutritional status using the Mini Nutritional Assessment-Short Form and analysis of the relevant factors in patients with head and neck tumour.

    PubMed

    Yanagi, Ayaka; Murase, Mai; Sumita, Yuka I; Taniguchi, Hisashi

    2017-06-01

    The aims of this study were to reveal the nutritional status of patients after head and neck tumour treatment by using the Mini Nutritional Assessment-Short Form (MNA-SF) and to analyse the factors affecting nutritional status in patients with head and neck tumour. Elderly patients with loss of teeth and maxillary/mandibular bone due to head and neck tumour treatment could be at high risk of malnutrition. However, there are few reports on the nutritional status of these patients. Forty-six participants (average age 74.7 years) were selected from patients who visited the maxillofacial prosthetics clinic of Tokyo Medical and Dental University Hospital Faculty of Dentistry in Japan. Nutritional status was evaluated using the MNA-SF. Multiple regression analysis was used to identify predictors affecting MNA-SF score. The candidate explanatory variables were age, sex, maxillofacial prosthesis use, number of residual teeth, resection side, neck dissection and treatment option. The results showed that approximately half of the patients were at risk of malnutrition, and a regression equation for MNA-SF score was developed using two predictors: maxillofacial prosthesis use and neck dissection. Use of a maxillofacial prosthesis can improve nutritional status. On the other hand, a medical history of neck dissection can decrease nutritional status. © 2016 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

  20. Model of beam head erosion

    SciTech Connect

    Lee, E.P.

    1980-08-08

    An analytical model of beam head dynamics is presented, leading to an estimate of the erosion rate due to the combined effects of Ohmic dissipation and scattering. Agreement with the results of a computer simulation and detailed one-dimensional computations is good in all respects except for the scaling of the erosion rate with net current.

  1. Accurate optimization of amino acid form factors for computing small-angle X-ray scattering intensity of atomistic protein structures

    SciTech Connect

    Tong, Dudu; Yang, Sichun; Lu, Lanyuan

    2016-06-20

    Structure modellingviasmall-angle X-ray scattering (SAXS) data generally requires intensive computations of scattering intensity from any given biomolecular structure, where the accurate evaluation of SAXS profiles using coarse-grained (CG) methods is vital to improve computational efficiency. To date, most CG SAXS computing methods have been based on a single-bead-per-residue approximation but have neglected structural correlations between amino acids. To improve the accuracy of scattering calculations, accurate CG form factors of amino acids are now derived using a rigorous optimization strategy, termed electron-density matching (EDM), to best fit electron-density distributions of protein structures. This EDM method is compared with and tested against other CG SAXS computing methods, and the resulting CG SAXS profiles from EDM agree better with all-atom theoretical SAXS data. By including the protein hydration shell represented by explicit CG water molecules and the correction of protein excluded volume, the developed CG form factors also reproduce the selected experimental SAXS profiles with very small deviations. Taken together, these EDM-derived CG form factors present an accurate and efficient computational approach for SAXS computing, especially when higher molecular details (represented by theqrange of the SAXS data) become necessary for effective structure modelling.

  2. Contribution of Coulomb explosion to form factors and mosaicity spread in single particle X-ray scattering.

    PubMed

    Debnarova, Andrea; Techert, Simone; Schmatz, Stefan

    2014-01-14

    The Coulomb explosion of the octamer water cluster has been studied employing time-dependent density functional theory explicitly accounting for the laser field and thus not imposing any constraint on the interaction between the laser pulse and the cluster. We focus on the effects of electron density changes in the system under high-intensity (10(16) and 10(15) W cm(-2)) soft X-ray laser pulses and their fingerprint in the reciprocal space, namely the ultrafast changes in X-ray diffuse scattering signals in k-space (in the investigated k-space range from 10(-3) up to 10 Å(-1)). The present simulations indicate that diffusional components in X-ray intensity changes propagate from low reciprocal resolution (resembling the small-angle X-ray scattering regime) to very high resolution (the wide-angle X-ray scattering regime) during the Coulomb explosion process.

  3. Comparison of techniques that use the single scattering model to compute the quality factor Q from coda waves

    USGS Publications Warehouse

    Novelo-Casanova, D. A.; Lee, W.H.K.

    1991-01-01

    Using simulated coda waves, the resolution of the single-scattering model to extract coda Q (Qc) and its power law frequency dependence was tested. The back-scattering model of Aki and Chouet (1975) and the single isotropic-scattering model of Sato (1977) were examined. The results indicate that: (1) The input Qc models are reasonably well approximated by the two methods; (2) almost equal Qc values are recovered when the techniques sample the same coda windows; (3) low Qc models are well estimated in the frequency domain from the early and late part of the coda; and (4) models with high Qc values are more accurately extracted from late code measurements. ?? 1991 Birkha??user Verlag.

  4. An Analysis of Heavy-Ion Elastic Scattering Processes Using Numerical Model Based on the Partial Wave Parameterised S-Matrix with Regge Pole Factor

    NASA Astrophysics Data System (ADS)

    Badran, R. I.; Al-Lehyani, I. H.

    2016-06-01

    Analyses of the angular distributions in the elastic scattering processes of 9, 10, 11Be by the target nucleus 64Zn at the laboratory energies of 27.95 MeV, and 4, 6, 8He by the target nucleus 208Pb at the laboratory energy of 22 MeV are performed. These analyses rely on a numerical model based on a parameterised scattering matrix (S-matrix) derived from Frahn and Venter. They confirm the absence of the Coulomb rainbow peak in angular distributions of elastic scattering in collisions of halo nuclei at energies around the Coulomb barrier. The correlation between the total reaction cross section and the halo structure for each scattering that involves a halo nucleus is discussed, and values of the total reaction cross section are found comparable with those of others. The diffractive features of the systems 16, 18O + 19F at specific laboratory energies are examined, and the effect of exchanging the projectile and target nuclei at such energies on these features are inspected. The incorporation of the Regge pole factor into the parameterised S-matrix calculations, which is found important in some cases, is employed in order to account for the oscillatory structure (if available) at backward angles. The theoretical results are found reasonable, reproducing the general pattern of the data. The trend of the extracted parameters meets the requirements proposed by the adopted models.

  5. Anthropogenic Factors Are the Major Cause of Hospital Admission of a Threatened Species, the Grey-Headed Flying Fox (Pteropus poliocephalus), in Victoria, Australia.

    PubMed

    Scheelings, Titus Franciscus; Frith, Sarah Elizabeth

    2015-01-01

    To determine the reasons for presentation and outcomes of hospitalised grey-headed flying foxes (Pteropus poliocephalus) in Victoria, Australia, a retrospective analysis was performed on 532 records from two wildlife hospitals. Cases were categorised based on presenting signs and outcomes determined. Anthropogenic factors (63.7%) were a major cause of flying fox admissions with entanglement in fruit netting the most significant risk for bats (36.8%). Overall the mortality rate for flying fox admissions was 59.3%. This study highlights the effects of urbanisation on wild animal populations and a need for continued public education in order to reduce morbidity and mortality of wildlife, especially threatened species.

  6. Anthropogenic Factors Are the Major Cause of Hospital Admission of a Threatened Species, the Grey-Headed Flying Fox (Pteropus poliocephalus), in Victoria, Australia

    PubMed Central

    Scheelings, Titus Franciscus; Frith, Sarah Elizabeth

    2015-01-01

    To determine the reasons for presentation and outcomes of hospitalised grey-headed flying foxes (Pteropus poliocephalus) in Victoria, Australia, a retrospective analysis was performed on 532 records from two wildlife hospitals. Cases were categorised based on presenting signs and outcomes determined. Anthropogenic factors (63.7%) were a major cause of flying fox admissions with entanglement in fruit netting the most significant risk for bats (36.8%). Overall the mortality rate for flying fox admissions was 59.3%. This study highlights the effects of urbanisation on wild animal populations and a need for continued public education in order to reduce morbidity and mortality of wildlife, especially threatened species. PMID:26207984

  7. Prevalence of fibroblast growth factor receptor 1 (FGFR1) amplification in squamous cell carcinomas of the head and neck.

    PubMed

    Clauditz, Till Sebastian; Böttcher, Arne; Hanken, Henning; Borgmann, Kerstin; Sauter, Guido; Wilczak, Waldemar; Grob, Tobias; Münscher, Adrian

    2017-10-11

    FGFR1 is a receptor tyrosine kinases involved in tumor growth signaling, survival, and differentiation in many solid cancer types. There is growing evidence that FGFR1 amplification might predict therapy response to FGFR1 inhibitors in squamous cell lung cancers. To estimate the potential applicability of anti FGFR1 therapies in squamous cell carcinomas of the head and neck, we studied patterns of FGFR1 amplification using fluorescence in situ hybridization (FISH). A tissue microarray was constructed from 453 primary treatment-naive squamous cell carcinomas of the head and neck regions with histopathological and clinical follow-up data [including oral cavity (n = 222), oropharynx (n = 126), and larynx (n = 105)]. FGFR1 and centromere 8 copy numbers were assessed by dual-color FISH. FGFR1 amplification was defined as a copy number ratio FGFR1: centromere 8 ≥ 2.0. HPV sequencing and p16 immunohistochemistry (IHC) were applied to FGFR1-amplified cancers. FISH analysis was successful in 297 (66%) of the 453 cancers. FGFR1 amplification was found in 6% of analyzable tumors, and was more frequent in tumors of the oral cavity (13/133 amplified, 10%), than cancers of other localizations (1/79 oropharynx, 4/85 larynx; p = 0.007 and 0.159, respectively). One out of 18 FGFR1 amplified cancers was HPV positive. No associations were found between FGFR1 amplification and tumor phenotype or p16 IHC. Head and neck cancers are recurrently affected by FGFR1 amplification, with a predominance in cancers of the oral cavity. Finding only one HPV positive and FGFR1 amplified cancer argues against a causal relationship between HPV and FGFR1 amplifications.

  8. Ethnicity, location, age, and fluoridation factors in baby bottle tooth decay and caries prevalence of Head Start children.

    PubMed Central

    Barnes, G P; Parker, W A; Lyon, T C; Drum, M A; Coleman, G C

    1992-01-01

    Baby bottle tooth decay (BBTD) is a term applied to a specific form of rampant decay associated with inappropriate bottle or breast feeding of infants and young children. Although the prevalence of BBTD has been studied in individual ethnic groups, comparison studies are rare. Head Start children have frequently served as study subjects for assessing the prevalence of BBTD. The purpose of this study was to compare BBTD and caries prevalence among Head Start children who are members of four ethnic groups in five southwestern States. Age, residence, and fluoridation status were also compared for the total sample and ethnic categories. The sampling process was a stratified random site selection; it was used to obtain data on 1,230 children. This number constituted 3 percent of the children enrolled in Head Start in Public Health Service Region VI (Arkansas, Louisiana, New Mexico, Oklahoma, and Texas) where the study was conducted. The criterion for determining the presence of BBTD was based on the number of carious deciduous maxillary incisors observed. The severity of the condition was reported as two of four and three of four of the target teeth affected. Thus, two levels of severity are reported. BBTD was prevalent in approximately 24 percent and 15 percent of the total sample, depending on the severity criterion used. Native American children had a significantly higher (P less than 0.05) prevalence than Hispanic, white, and black subjects. Rural children had significantly higher (P less than 0.05) prevalence of BBTD than nonrural children for all ethnic groups except whites.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 1. PMID:1561298

  9. Pretreatment count of peripheral neutrophils, monocytes, and lymphocytes as independent prognostic factor in patients with head and neck cancer.

    PubMed

    Valero, Cristina; Pardo, Laura; López, Montserrat; García, Jacinto; Camacho, Mercedes; Quer, Miquel; León, Xavier

    2017-02-01

    The purpose of this study was to analyze the prognostic value of pretreatment count of peripheral neutrophils, lymphocytes, monocytes, and neutrophil-to-lymphocyte ratio (NLR) in patients with head and neck squamous cell carcinoma (HNSCC). Local, regional, and distant recurrence-free survival and disease-specific survival were analyzed according to the count of neutrophils, lymphocytes, monocytes, and NLR. We observed a decrease in disease-specific survival as the quartile category of neutrophils, monocytes, and NLR increased. In the case of lymphocytes, patients in the lower quartile had lower disease-specific survival. Considering the disease-specific survival as the dependent variable, a recursive partitioning analysis classified the patients according to the neutrophil and monocyte counts. High pretreatment count of peripheral neutrophils and/or monocytes was independently related with worse prognosis in patients with HNSCC. Classification based on pretreatment neutrophil and monocyte counts enabled the identification of different prognostic profiles. © 2016 Wiley Periodicals, Inc. Head Neck 39: 219-226, 2017. © 2016 Wiley Periodicals, Inc.

  10. Lifetime Prevalence and Factors Associated with Head Injury among Older People in Low and Middle Income Countries: A 10/66 Study

    PubMed Central

    Khan, A.; Prince, M.; Brayne, C.; Prina, A. M.

    2015-01-01

    Introduction Traumatic brain injury (TBI) is a growing public health problem around the world, yet there is little information on the prevalence of head injury in low and middle income countries (LMICs). We utilised data collected by the 10/66 research group to investigate the lifetime prevalence of head injury in defined sites in low and middle income countries, its risk factors and its relationship with disability. Methods We analysed data from one-phase cross-sectional surveys of all residents aged 65 years and older (n = 16430) distributed across twelve sites in eight low and middle income countries (China, Cuba, Dominican Republic, India, Venezuela, Mexico, Peru, and Puerto Rico). Self-reported cases of head injury with loss of consciousness were identified during the interview. A sensitivity analysis including data provided by informants of people with dementia was also used to estimate the impact of this information on the estimates. Prevalence ratios (PR) from Poisson regressions were used to identify associated risk factors. Results The standardised lifetime prevalence of TBI ranged from 0.3% in China to 14.6% in rural Mexico and Venezuela. Being male (PR: 1.6, 95% CI: 1.29–1.82), younger (PR: 0.95, 95% CI: 0.92–0.99), with lower education (PR 0.91, 95% CI: 0.86–0.96), and having fewer assets (PR 0.92, 95% CI: 0.88–0.96), was associated with a higher prevalence of TBI when pooling estimates across sites. Discussion Our analysis revealed that the prevalence of TBI in LMICs is similar to that of developed nations. Considering the growing impact of TBI on health resources in these countries, there is an urgent need for further research. PMID:26146992

  11. Lifetime Prevalence and Factors Associated with Head Injury among Older People in Low and Middle Income Countries: A 10/66 Study.

    PubMed

    Khan, A; Prince, M; Brayne, C; Prina, A M

    2015-01-01

    Traumatic brain injury (TBI) is a growing public health problem around the world, yet there is little information on the prevalence of head injury in low and middle income countries (LMICs). We utilised data collected by the 10/66 research group to investigate the lifetime prevalence of head injury in defined sites in low and middle income countries, its risk factors and its relationship with disability. We analysed data from one-phase cross-sectional surveys of all residents aged 65 years and older (n = 16430) distributed across twelve sites in eight low and middle income countries (China, Cuba, Dominican Republic, India, Venezuela, Mexico, Peru, and Puerto Rico). Self-reported cases of head injury with loss of consciousness were identified during the interview. A sensitivity analysis including data provided by informants of people with dementia was also used to estimate the impact of this information on the estimates. Prevalence ratios (PR) from Poisson regressions were used to identify associated risk factors. The standardised lifetime prevalence of TBI ranged from 0.3% in China to 14.6% in rural Mexico and Venezuela. Being male (PR: 1.6, 95% CI: 1.29-1.82), younger (PR: 0.95, 95% CI: 0.92-0.99), with lower education (PR 0.91, 95% CI: 0.86-0.96), and having fewer assets (PR 0.92, 95% CI: 0.88-0.96), was associated with a higher prevalence of TBI when pooling estimates across sites. Our analysis revealed that the prevalence of TBI in LMICs is similar to that of developed nations. Considering the growing impact of TBI on health resources in these countries, there is an urgent need for further research.

  12. [Analysis of Scattered Radiation in an Irradiated Body by Means of the Monte Carlo Simulation: Back-scatter Factors of Diagnostic X-rays in the Incident Surface Which is Not Flat].

    PubMed

    Kato, Hideki; Minami, Kazuyuki; Asada, Yasuki; Suzuki, Shoichi

    2016-05-01

    To obtain patient entrance surface dose in X-ray photography, a calculation method based on measured exposure or air kerma radiated from X-ray tube is generally used. Two factors are necessary for this calculation: (1) exposure/air kerma to absorb dose conversion factor and (2) back-scatter factor (BSF) based on X-ray quality and on field size. These BSFs are commonly obtained by interpolation from existent data which were given for a water phantom whose entrance surface is flat. Since patient's surface in X-ray photograph is not flat, some error may occur when existent BSF is used in this calculation. In this article, BSF for water phantom with cylindrical surface and elliptic cylinder surface were calculated by means of the Monte Carlo simulation. And these BSFs were compared with BSF for flat surface phantom. As a result (1) radius of curvature of cylindrical phantom or horizontal axis of elliptic cylinder phantom is smaller, (2) half value layer of X-ray is larger, (3) field size is larger, difference of these BSF with that for flat surface phantom tends to be larger. Maximum difference by calculation condition assumed in this article was more than 10%. The cause of this difference is because scattering volume in irradiated body of cylindrical or elliptic cylinder phantom is smaller than flat surface phantom. To obtain patient entrance surface dose more precisely, it is necessary to use BSF respectively calculated for phantom resembling patient's body such as cylindrical or elliptic cylinder phantom by means of the Monte Carlo simulation.

  13. Determination of {sup 16}O and {sup 18}O sensitivity factors and charge-exchange processes in low-energy ion scattering

    SciTech Connect

    Tellez, H.; Chater, R. J.; Fearn, S.; Symianakis, E.; Kilner, J. A.; Brongersma, H. H.

    2012-10-08

    Quantitative analysis in low-energy ion scattering (LEIS) requires an understanding of the charge-exchange processes to estimate the elemental sensitivity factors. In this work, the neutralization of He{sup +} scattered by {sup 18}O-exchanged silica at energies between 0.6 and 7 keV was studied. The process is dominated by Auger neutralization for E{sub i} < 0.8 keV. An additional mechanism starts above the reionization threshold. This collision-induced neutralization becomes the dominant mechanism for E{sub i} > 2 keV. The ion fractions P{sup +} were determined for Si and O using the characteristic velocity method to quantify the surface density. The {sup 18}O/{sup 16}O sensitivity ratio indicates an 18% higher sensitivity for the heavier O isotope.

  14. Head Injuries

    MedlinePlus

    ... won't stop crying complains of head and neck pain (younger or nonverbal children may be more fussy) ... vision pupils of unequal size weakness or paralysis neck pain or stiffness seizure If your child is unconscious: ...

  15. Head Noises.

    ERIC Educational Resources Information Center

    Senior, Tom

    2000-01-01

    Explains how a toy called "Sound Bites" can be modified to demonstrate the transmission of sound waves. Students can hear music from the toy when they press it against any bone in their heads or shoulders. (WRM)

  16. Head Injuries

    MedlinePlus

    ... before. Often, the injury is minor because your skull is hard and it protects your brain. But ... injuries can be more severe, such as a skull fracture, concussion, or traumatic brain injury. Head injuries ...

  17. Head Noises.

    ERIC Educational Resources Information Center

    Senior, Tom

    2000-01-01

    Explains how a toy called "Sound Bites" can be modified to demonstrate the transmission of sound waves. Students can hear music from the toy when they press it against any bone in their heads or shoulders. (WRM)

  18. Head Tilt

    MedlinePlus

    ... Throat Emotional Problems Eyes Fever From Insects or Animals Genitals and Urinary Tract Glands & Growth Head Neck & Nervous System Heart Infections Learning Disabilities Obesity Orthopedic Prevention Sexually Transmitted Skin Tobacco ...

  19. Head Injuries

    MedlinePlus

    ... object that's stuck in the wound. previous continue Concussions Concussions — the temporary loss of normal brain function due ... also a type of internal head injury. Repeated concussions can permanently damage the brain. In many cases, ...

  20. Pro-osteogenic effects of fibrin glue in treatment of avascular necrosis of the femoral head in vivo by hepatocyte growth factor-transgenic mesenchymal stem cells

    PubMed Central

    2014-01-01

    Background Autologous transplantation of modified mesenchymal stem cells (MSCs) is a promising candidate for the treatment of the refractory clinical disease, avascular necrosis of the femoral head (ANFH). Our previous attempts by compounding MSCs with medical fibrin glue to treat ANFH in animal model have achieved excellent effects. However, the underlying molecular mechanism is unclear, especially on the transgenic gene expression. Methods Rabbit MSCs were isolated and compounded with fibrin glue. Following degrading of fibrin glue, proliferation, viability, expression of transgenic hepatocyte growth factor gene as well as osteogenic differentiation of MSCs were evaluated together with that of uncompounded MSCs. Fibrin glue-compounded MSCs were transplanted into the lesion of ANFH model, and the therapeutic efficacy was compared with uncompounded MSCs. One-Way ANOVA was used to determine the statistical significance among treatment groups. Results Fibrin glue compounding will not affect molecular activities of MSCs, including hepatocyte growth factor (HGF) secretion, cell proliferation and viability, and osteogenic differentiation in vitro. When applying fibrin glue-compounded MSCs for the therapy of ANFH in vivo, fibrin glue functioned as a drug delivery system and provided a sustaining microenvironment for MSCs which helped the relatively long-term secretion of HGF in the femoral head lesion and resulted in improved therapeutic efficacy when compared with uncompounded MSCs as indicated by hematoxylin-eosin staining and immunohistochemistry of osteocalcin, CD105 and HGF. Conclusion Transplantation of fibrin glue-compounding MSCs is a promising novel method for ANFH therapy. PMID:24885252

  1. Mild pulmonary emphysema a risk factor for interstitial lung disease when using cetuximab for squamous cell carcinoma of the head and neck.

    PubMed

    Okamoto, Isaku; Tsukahara, Kiyoaki; Sato, Hiroki; Motohashi, Ray; Yunaiyama, Daisuke; Shimizu, Akira

    2017-12-01

    Interstitial lung disease (ILD) is an occasionally fatal adverse event associated with cetuximab (Cmab) therapy. Our objective was to clarify to what degree pulmonary emphysema is a risk factor in the treatment of head and neck cancer with Cmab through a retrospective analysis. Subjects were 116 patients who were administered Cmab for head and neck squamous cell carcinoma. The degree of pulmonary emphysema before initiating treatment with Cmab was visually assessed retrospectively, with scoring according to the Goddard classification used in Japanese chronic obstructive pulmonary disease (COPD) guidelines for chest computed tomography (CT). Scoring was conducted by two diagnostic radiologists and mean scores were used. Cutoffs for the development and nondevelopment of ILD were examined by receiver operating characteristic (ROC) analysis and Fisher's exact test. Values of p < .05 were considered to indicate a significant difference. Among the 116 patients, 11 (9.5%) developed ILD, and 105 (90.5%) did not. In ROC analysis, the optimal Goddard score cut-off of <3.0 offered 55% sensitivity and 81% specificity (p = .015). With a cutoff of <3.0, even very mild pulmonary emphysema would represent a risk factor for ILD when using Cmab.

  2. Factors influencing the quality of undergraduate clinical restorative dentistry in the UK and ROI: the views of heads of units.

    PubMed

    Martin, N; Fairclough, A; Smith, M; Ellis, L

    2010-06-01

    In the light of concerns regarding expanded student intakes and reported workforce difficulties, a 2008 survey of heads of departments of restorative dentistry in UK and ROI dental schools sought to clarify the current situation with regard to: workforce configuration; barriers and facilitators of quality undergraduate clinical restorative dentistry; and, implications of the above for programme delivery. The response rate was 100% for the workforce statistics and 65% for the remainder of the survey. Findings were largely consistent across the 14 schools. Workforces were increasingly part-time with a shortage of full-time academics. While resources had generally expanded to meet increased student numbers and outreach teaching had augmented clinical learning, difficulties in recruiting patients and communicating with a fragmented workforce were risking the quality of undergraduate curricula. Issues to be addressed include a pervading sense of teaching being undervalued and staffing being sub-optimal.

  3. g-factor and quadrupole moment of the 21/2- isomeric state in 131La: Signature for a weakly-deformed magnetic rotational band head

    NASA Astrophysics Data System (ADS)

    Kaur, Jasmeet; Bansal, Neeraj; Bhati, A. K.; Kumar, R.; Sharma, Vijay R.; Kapoor, K.; Kumar, V.; Kaur, Navneet

    2017-02-01

    The g-factor and the static quadrupole moment of a magnetic rotational band head 21/2- at 2121 keV in 131La have been determined by means of the time-differential perturbed angular distribution technique. The measured value of the g-factor, + 1.060 (4), is in agreement with the theoretical value for a three quasi-proton, π3 {11/2- [ 505 ] ⊗5/2+ [ 422 ] ⊗5/2+ [ 413 ] } Nilsson configuration assignment. The observed spectroscopic quadrupole moment ratio, Qs (21/2- ,131 La)/Qs (19/2- ,137 La) = 0.457 (4), supports the collective oblate shape (γ ∼ - 60 °) with quadrupole deformation β2 < 0.07. The half-life of the 21/2- state, 37.2(1) ns, is re-measured with better accuracy.

  4. A Measurement of the neutron electric form factor at very large momentum transfer using polaried electrions scattering from a polarized helium-3 target

    SciTech Connect

    Kelleher, Aidan

    2010-02-01

    Knowledge of the electric and magnetic elastic form factors of the nucleon is essential for an understanding of nucleon structure. Of the form factors, the electric form factor of the neutron has been measured over the smallest range in Q2 and with the lowest precision. Jefferson Lab experiment 02-013 used a novel new polarized 3 He target to nearly double the range of momentum transfer in which the neutron form factor has been studied and to measure it with much higher precision. Polarized electrons were scattered off this target, and both the scattered electron and neutron were detected. Gn E was measured to be 0.0242 ± 0.0020(stat) ± 0.0061(sys) and 0.0247 ± 0.0029(stat) ± 0.0031(sys) at Q2 = 1.7 and 2.5 GeV2 , respectively.

  5. SU-E-T-59: Calculations of Collimator Scatter Factors (Sc) with and Without Custom-Made Build-Up Caps for CyberKnife

    SciTech Connect

    Wokoma, S; Yoon, J; Jung, J; Lee, S

    2014-06-01

    Purpose: To investigate the impact of custom-made build-up caps for a diode detector in robotic radiosurgery radiation fields with variable collimator (IRIS) for collimator scatter factor (Sc) calculation. Methods: An acrylic cap was custom-made to fit our SFD (IBA Dosimetry, Germany) diode detector. The cap has thickness of 5 cm, corresponding to a depth beyond electron contamination. IAEA phase space data was used for beam modeling and DOSRZnrc code was used to model the detector. The detector was positioned at 80 cm source-to-detector distance. Calculations were performed with the SFD, with and without the build-up cap, for clinical IRIS settings ranging from 7.5 to 60 mm. Results: The collimator scatter factors were calculated with and without 5 cm build-up cap. They were agreed within 3% difference except 15 mm cone. The Sc factor for 15 mm cone without buildup was 13.2% lower than that with buildup. Conclusion: Sc data is a critical component in advanced algorithms for treatment planning in order to calculate the dose accurately. After incorporating build-up cap, we discovered differences of up to 13.2 % in Sc factors in the SFD detector, when compared against in-air measurements without build-up caps.

  6. Head Injuries in Children

    PubMed Central

    Craft, A. W.; Shaw, D. A.; Cartlidge, N. E. F.

    1972-01-01

    Two-hundred children with head injury admitted consecutively to paediatric wards in the two main hospitals in Newcastle upon Tyne have been studied. Eight children required neurosurgical operation. There were two deaths. Details of the cause and consequences of the accidents have been analysed and an attempt has been made to identify psychological or physical factors that may predispose to injury. There was a slightly higher proportion of children with what are regarded as adverse personality factors among the head injuries than in a control group and there were more left-handed children than would be expected in the general population. The results suggest that the modern “high-rise” bicycle may carry a special risk of head injury. PMID:5082547

  7. Is trauma transfer influenced by factors other than medical need? An examination of insurance status and transfer in patients with mild head injury.

    PubMed

    Babu, Maya A; Nahed, Brian V; Demoya, Marc A; Curry, William T

    2011-09-01

    The Emergency Medical Treatment and Active Labor Act was meant to provide access to emergency medical care irrespective of financial resources. Yet, many Level I trauma Centers have raised concerns about the financial drivers influencing transfer. : To study the relationship between insurance status and transfer, we focused on patients with mild head injury to tease apart the medical necessity for transfer from other potential drivers, such as financial factors. Using the 2002 to 2006 American College of Surgeons National Trauma Databank and Massachusetts General Hospital's Trauma Databank from 1993 to 2009, we conducted a retrospective study and limited our population to patients with mild head injuries and mild to moderate systemic injuries as determined by the Glasgow Coma Scale, Abbreviated Injury Scale, or Injury Severity Score. Statistical analyses were conducted with STATA software. In a nationalized database, (1) uninsured patients with mild head injury are more likely to be transferred out of a Level II or III facility (adjusted odds ratio [OR]: 2.07; P = .000) compared with privately insured patients and (2) uninsured patients are less likely to be accepted by a Level II or III facility for transfer compared with privately insured patients (adjusted OR: = .143; P = .000l). For transfers received by 1 Level I trauma center (Massachusetts General Hospital), uninsured patients are more likely to be transferred to (1) Massachusetts General Hospital between midnight and 6 am (adjusted OR: 5.201; P = .000) compared with other time periods throughout the day and (2) Massachusetts General Hospital on Sunday (adjusted OR: 1.09; P = .000) compared with other days of the week. Insurance status appears to influence transfer patterns.

  8. Confirmatory factor analysis of the Wechsler Memory Scale-Revised in a sample of head-injured patients.

    PubMed

    Roth, D L; Conboy, T J; Reeder, K P; Boll, T J

    1990-12-01

    As part of a standard evaluation of neuropsychological sequelae, the Wechsler Memory Scale-Revised (WMS-R) was administered to 107 patients with a history of traumatic brain injury. Confirmatory factor analyses were conducted on the 12 subtests of the WMS-R to examine the fit of various hypothesized factor patterns, including patterns identified in previous exploratory factor analytic studies. Because part of the correlation between immediate and delayed recall trials of the same material is attributable to a common measurement procedure, this correlation due to measurement commonality was partialled out of the conceptual factor structure. The results suggested the presence of 3 distinct but highly correlated factors: attention/concentration, immediate memory, and delayed recall. Models that posited separate verbal and nonverbal memory processes failed to improve fit over more parsimonious models. Comparisons with previous factor analytic studies and implications for clinical assessment are discussed.

  9. A comparative study of small field total scatter factors and dose profiles using plastic scintillation detectors and other stereotactic dosimeters: The case of the CyberKnife

    SciTech Connect

    Morin, J.; Beliveau-Nadeau, D.; Chung, E.; Seuntjens, J.; Theriault, D.; Archambault, L.; Beddar, S.; Beaulieu, L.

    2013-01-15

    Purpose: Small-field dosimetry is challenging, and the main limitations of most dosimeters are insufficient spatial resolution, water nonequivalence, and energy dependence. The purpose of this study was to compare plastic scintillation detectors (PSDs) to several commercial stereotactic dosimeters by measuring total scatter factors and dose profiles on a CyberKnife system. Methods: Two PSDs were developed, having sensitive volumes of 0.196 and 0.785 mm{sup 3}, and compared with other detectors. The spectral discrimination method was applied to subtract Cerenkov light from the signal. Both PSDs were compared to four commercial stereotactic dosimeters by measuring total scatter factors, namely, an IBA dosimetry stereotactic field diode (SFD), a PTW 60008 silicon diode, a PTW 60012 silicon diode, and a microLion. The measured total scatter factors were further compared with those of two independent Monte Carlo studies. For the dose profiles, two commercial detectors were used for the comparison, i.e., a PTW 60012 silicon diode and Gafchromics EBT2. Total scatter factors for a CyberKnife system were measured in circular fields with diameters from 5 to 60 mm. Dose profiles were measured for the 5- and 60-mm cones. The measurements were performed in a water tank at a 1.5-cm depth and an 80-cm source-axis distance. Results: The total scatter factors measured using all the detectors agreed within 1% with the Monte Carlo values for cones of 20 mm or greater in diameter. For cones of 10-20 mm in diameter, the PTW 60008 silicon diode was the only dosimeter whose measurements did not agree within 1% with the Monte Carlo values. For smaller fields (<10 mm), each dosimeter type showed different behaviors. The silicon diodes over-responded because of their water nonequivalence; the microLion and 1.0-mm PSD under-responded because of a volume-averaging effect; and the 0.5-mm PSD was the only detector within the uncertainties of the Monte Carlo simulations for all the cones. The

  10. Monte Carlo simulations of neutron spectral fluence, radiation weighting factor and ambient dose equivalent for a passively scattered proton therapy unit

    NASA Astrophysics Data System (ADS)

    Zheng, Yuanshui; Fontenot, Jonas; Taddei, Phil; Mirkovic, Dragan; Newhauser, Wayne

    2008-01-01

    Stray neutron exposures pose a potential risk for the development of secondary cancer in patients receiving proton therapy. However, the behavior of the ambient dose equivalent is not fully understood, including dependences on neutron spectral fluence, radiation weighting factor and proton treatment beam characteristics. The objective of this work, therefore, was to estimate neutron exposures resulting from the use of a passively scattered proton treatment unit. In particular, we studied the characteristics of the neutron spectral fluence, radiation weighting factor and ambient dose equivalent with Monte Carlo simulations. The neutron spectral fluence contained two pronounced peaks, one a low-energy peak with a mode around 1 MeV and one a high-energy peak that ranged from about 10 MeV up to the proton energy. The mean radiation weighting factors varied only slightly, from 8.8 to 10.3, with proton energy and location for a closed-aperture configuration. For unmodulated proton beams stopped in a closed aperture, the ambient dose equivalent from neutrons per therapeutic absorbed dose (H*(10)/D) calculated free-in-air ranged from about 0.3 mSv/Gy for a small scattered field of 100 MeV proton energy to 19 mSv/Gy for a large scattered field of 250 MeV proton energy, revealing strong dependences on proton energy and field size. Comparisons of in-air calculations with in-phantom calculations indicated that the in-air method yielded a conservative estimation of stray neutron radiation exposure for a prostate cancer patient.

  11. SU-E-T-536: Is BJR Supplement #25 Recommendation for Megavoltage Energy Independent Scatter Factor Still Valid for Flattening Filter Free Photon Beams?

    PubMed

    Chung, H; Yi, B; Prado, K

    2012-06-01

    In the process of measuring and validating fundamental dosimetry data prior to the clinical use of a treatment unit, it is prudent to compare measurements with previously published equivalent data. During the commissioning of an accelerator with flattening filter free (FFF) photon beams (Varian True Beam 6 MV FFF and 10 MV FFF) we compared measured Phantom Scatter Factors (Sp) with the Normalized Peak Scatter Factors (NPSFs) from the British Journal of Radiology Supplement 25 (BJR #25). The purpose of this work was to determine whether the energy independent NPSFs BJR#25 are valid for comparison with FFF photon beams. All measurements were performed using a Varian TrueBeam linear accelerator with photon energies of 6-MV, 6-MV FFF and 10-MV FFF modes. For all measurements, a Scanditronix CC04 ionization chamber was used. Both water and in-air measurements were made to obtain NPSFs normalized to the 10 × 10 cm(2) field size. For measurements in water, the chamber was positioned at 100 cm source-to-axis distance at the depth of dose maximum. For in-air measurements, the chamber was positioned at 100 cm source-to-axis distance with appropriate build-up cap. From BJR #25, NPSFs were obtained for comparison with the measurements. The NPSF agreement between the 6-MV and 6-MV FFF with the BJR#25 were all within ±0.5%. The agreement ranged from 0.996 to 1.004 and 0.995 to 1.002 for 6-MV and 6-MV FFF, respectively. We also found that 10-MV FFF showed very similar trend. The scatter factors reported in BJR #25 are valid for comparison for 6-MV, 6-MV FFF, and 10-MV. Additional investigation is needed to further understand the dosimetric characteristics of FFF mode. © 2012 American Association of Physicists in Medicine.

  12. Effects of Modified Qing'e Pill () on expression of adiponectin, bone morphogenetic protein 2 and coagulation-related factors in patients with nontraumatic osteonecrosis of femoral head.

    PubMed

    Li, Cheng-Gang; Shen, Lin; Yang, Yan-Ping; Xu, Xiao-Juan; Shuai, Bo; Ma, Chen

    2017-03-01

    To observe the regulation of Chinese herbal medicine, Modifified Qing'e Pill (, MQEP), on the expression of adiponectin, bone morphogenetic protein 2 (BMP2), osteoprotegerin (OPG) and other potentially relevant risk factors in patients with nontraumatic osteonecrosis of the femoral head (ONFH). A total of 96 patients with nontraumatic ONFH were unequal randomly divided into treatment group (60 cases) and control group (36 cases). The treatment group were treated with MQEP while the control group were treated with simulated pills. Both groups were given caltrate D. Six months were taken as a treatment course. Patients were followed up every 2 months. The levels of plasma adiponectin, BMP2, OPG, von Willebrand factor (vWF), von Willebrand factor cleaving protease (vWF-cp), plasminogen activator inhibitor 1 (PAI-1), tissue plasminogen activator (tPA), C-reactive protein (CRP), blood rheology, bone mineral density (BMD) of the femoral head and Harris Hip Score were measured before and after treatment. After 6 months of treatment, compared with the control group, patients in the treatment group had signifificantly higher adiponectin and BMP2 levels (P<0.01 and P=0.013, respectively), lower vWF, PAI-1 and CRP levels (P=0.019, P<0.01 and P<0.01, respectively), and lower blood rheology parameters. BMD of the femoral neck, triangle area and Harris Hip Score in the treatment group were signifificantly higher than those in the control group. Moreover, plasma adiponectin showed a positive association with BMP2 (r=0.231, P=0.003) and a negative association with PAI-1 (r=-0.159, P<0.05). MQEP may play a protective role against nontraumatic ONFH by increasing the expression of adiponectin, regulating bone metabolism and improving the hypercoagulation state, which may provide an experimental base for its clinical effects.

  13. Wound-healing factors can prime head and neck cancer cells to increase their tumor-forming capacity.

    PubMed

    Lindgren, Gustaf; Kjellén, Elisabeth; Wennerberg, Johan; Ekblad, Lars

    2016-06-01

    We investigated whether exposing a wound-healing-sensitive cell line to human wound fluid (HWF) could prime the cells to increase their tumor-forming ability in nude mice and, if so, whether this ability can be inhibited by pharmacological substances. Experimental animal model. Take rate was measured in BALB/c nude mice after pretreatment of the cells with HWF using human serum and fetal bovine serum as controls. Inhibition of signal transducer and activator of transcription 3 (STAT3) with S3I-201 tocilizumab, and of interleukin 6 receptor (IL6R) with tocilizumab was performed. Preincubation with HWF resulted in a significant increase in take rate compared to controls. The increase in take rate could be decreased by both STAT3 and IL6R inhibition. The results indicate that head and neck squamous cell cancer cells might be stimulated to increase their tumor-forming ability both close to a surgical wound and at more distant locations, as a consequence of the wound-healing response. The work also suggests new treatment modalities aimed at decreasing these stimulatory effects. NA Laryngoscope, 126:E213-E217, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  14. Influence of inoculum and climatic factors on the severity of Fusarium head blight in German spring and winter barley.

    PubMed

    Linkmeyer, Andrea; Hofer, Katharina; Rychlik, Michael; Herz, Markus; Hausladen, Hans; Hückelhoven, Ralph; Hess, Michael

    2016-01-01

    Fusarium head blight (FHB) of small cereals is a disease of global importance with regard to economic losses and mycotoxin contamination harmful to human and animal health. In Germany, FHB is predominantly associated with wheat and F. graminearum is recognised as the major causal agent of the disease, but little is known about FHB of barley. Monitoring of the natural occurrence of FHB on Bavarian barley revealed differences for individual Fusarium spp. in incidence and severity of grain infection between years and between spring and winter barley. Parallel measurement of fungal DNA content in grain and mycotoxin content suggested the importance of F. graminearum in winter barley and of F. langsethiae in spring barley for FHB. The infection success of these two species was associated with certain weather conditions and barley flowering time. Inoculation experiments in the field revealed different effects of five Fusarium spp. on symptom formation, grain yield and mycotoxin production. A significant association between fungal infection of grain and mycotoxin content was observed following natural or artificial infection with the type B trichothecene producer F. culmorum, but not with the type A trichothecene-producing species F. langsethiae and F. sporotrichioides. Trichothecene type A toxin contamination also occurred in the absence of significant damage to grain and did not necessarily promote fungal colonisation.

  15. Equilibrium Iron Isotope Fractionation Factors of Minerals: Reevaluation from the Data of Nuclear Inelastic Resonant X-ray Scattering and Mossbauer Spectroscopy

    SciTech Connect

    Polyakov, Dr. V. B.; Clayton, R. N.; Horita, Juske; Mineev, S. D.

    2007-01-01

    We have critically reevaluated equilibrium iron isotope fractionation factors for oxide and sulfide minerals using recently acquired data obtained by Moessbauer spectroscopy and inelastic nuclear resonant X-ray scattering (INRXS) synchrotron radiation. Good agreement was observed in the iron {beta}-factors of metallic iron ({alpha}-Fe) and hematite calculated using both Moessbauer- and INRXS-derived data, which supports the validity and reliability of the calculations. Based on this excellent agreement, we suggest the use of the present data on the iron {beta}-factors of hematite as a reference. The previous Moessbauer-derived iron {beta}-factor for magnetite has been modified significantly based on the Fe-sublattice density of states obtained from the INRXS experiments. This resolves the disagreement between naturally observed iron isotope fractionation factors for mineral pairs involving magnetite and those obtained from the calculated {beta}-factors. The correctness of iron {beta}-factor for pyrite has been corroborated by the good agreement with experimental data of sulfur isotope geothermometers of pyrite-galena and pyrite-sphalerite. A good correlation between the potential energy of the cation site, the oxidation state of iron and the iron {beta}-factor value has been established. Specifically, ferric compounds, which have a higher potential energy of iron than ferrous compounds, have higher {beta}-factors. A similar dependence of b-factors on the oxidation state and potential energy could be extended to other transition metals. Extremely low values of INRXS-derived iron {beta}-factors for troilite and Fe{sub 3}S significantly widen the range of iron b-factors for covalently bonded compounds.

  16. Small-angle scattering from phospholipid nanodiscs: derivation and refinement of a molecular constrained analytical model form factor.

    PubMed

    Skar-Gislinge, Nicholas; Arleth, Lise

    2011-02-28

    Nanodiscs™ consist of small phospholipid bilayer discs surrounded and stabilized by amphiphilic protein belts. Nanodiscs and their confinement and stabilization of nanometer sized pieces of phospholipid bilayer are highly interesting from a membrane physics point of view. We demonstrate how the detailed structure of Di-Lauroyl-Phosphatidyl Choline (DLPC) nanodiscs may be determined by simultaneous fitting of a structural model to small-angle scattering data from the nanodiscs as investigated in three different contrast situations, respectively two SANS contrasts and one SAXS contrast. The article gives a detailed account of the underlying structural model for the nanodiscs and describe how additional chemical and biophysical information can be incorporated in the model in terms of molecular constraints. We discuss and quantify the contribution from the different elements of the structural model and provide very strong experimental support for the nanodiscs as having an elliptical cross-section and with poly-histidine tags protruding out from the rim of the protein belt. The analysis also provides unprecedented information about the structural conformation of the phospholipids when these are localized in the nanodiscs. The model paves the first part of the way in order to reach our long term goal of using the nanodiscs as a platform for small-angle scattering based structural investigations of membrane proteins in solution.

  17. Evidence for integrity of the growth hormone/insulin-like growth factor-1 axis in patients with severe head trauma during rehabilitation.

    PubMed

    Bondanelli, Marta; Ambrosio, Maria Rosaria; Margutti, Angelo; Boldrini, Paolo; Basaglia, Nino; Franceschetti, Paola; Zatelli, Maria Chiara; Degli Uberti, Ettore C

    2002-10-01

    Severe traumatic head injury has been recognized to be associated with hypothalamo-hypophyseal impairment and subsequent abnormalities in hormone secretion, which can contribute to a prolonged clinical course and to hampered recovery in many head-injured patients. Most of the data on the growth hormone/insulin-like growth factor -1 (GH/IGF-1) axis function have been obtained early after head injury, whereas GH secretory pattern has not been fully elucidated after patients had left the intensive care unit. We examined the activity of the GH/IGF-1 axis in 16 severely closed head-injured (CHI) patients (14 males; age range, 17 to 47 years; body mass index [BMI], 21.4 +/- 0.8 kg/m(2)) during the rehabilitation period at least 1 month after leaving the intensive care unit and in 12 sex-, age-, and weight-matched healthy controls. The severity of trauma was assessed by the Glasgow Coma Scale (GCS) score (8 or less), posttraumatic amnesia (PTA, more than 24 hours), and initial computed tomography (CT) scan. The clinical picture at time of the study was evaluated by the Rancho Los Amigos Scale of Cognitive Functioning (CFS) and the Functional Independence Measure (FIM). In all subjects, we evaluated basal levels of anterior pituitary hormones, IGF-1, insulin-like growth factor-binding protein (IGFBP)-3, and IGFBP-1, as well as the GH responses to intravenous (IV) infusion of growth hormone-releasing hormone (GHRH) alone, GHRH plus arginine (ARG), and the GH release evoked by somatostatin (SRIH) infusion withdrawal, which is related to endogenous GHRH tone. In all subjects, nutritional parameters and nitrogen balance were normal. Basal plasma concentrations of GH, IGF-1, IGFBP-3, and IGFBP-1 did not significantly differ between CHI patients and controls. The GH responses to GHRH and GHRH plus ARG did not significantly differ between CHI patients (GH peak, 10.7 +/- 3.0 microg/L; area under the curve [AUC], 5.9 +/- 1.5 microg/L. min; and GH peak, 34.7 +/- 6.1 microg/L; AUC

  18. Kinetic factors of vertical jumping for heading a ball in flexible flatfooted amateur soccer players with and without insole adoption.

    PubMed

    Arastoo, Ali Asghar; Aghdam, Esmaeil Moharrami; Habibi, Abdoul Hamid; Zahednejad, Shahla

    2014-06-01

    According to literature, little is known regarding the effects of orthotic management of flatfoot on kinetics of vertical jump. To compare the kinetic and temporal events of two-legged vertical jumping take-off from a force plate for heading a ball in normal and flexible flatfoot subjects with and without insole. A functional based interventional controlled study. Random sampling method was employed to draw a control group of 15 normal foot subjects to a group of 15 flatfoot subjects. A force platform was used to record kinetics of two-legged vertical jump shots. Results indicate that insole did not lead to a significant effect on kinetics regarding anterior-posterior and mediolateral directions (p > 0.05). Results of kinetics related to vertical direction for maximum force due to take-off and stance duration revealed significant differences between the normal and flexible flatfoot subjects without insole (p < 0.05) and no significant differences between the normal foot and flexible flatfoot subjects with insole adoption (p > 0.05). These results suggest that the use of an insole in the flexible flatfoot subjects led to improved stance time and decrease of magnitude of kinetics regarding vertical direction at take-off as the main feature of two-legged vertical jumping function. Adoption of the insole improved the design of the shoe-foot interface support for the flexible flatfoot athletes, enabling them to develop more effective take-off kinetics for vertical jumping in terms of ground reaction force and stance duration similar to that of normal foot subjects without insole. © The International Society for Prosthetics and Orthotics 2013.

  19. Classical risk factors, but not HPV status, predict survival after chemoradiotherapy in advanced head and neck cancer patients.

    PubMed

    Descamps, Géraldine; Karaca, Yasemin; Lechien, Jérôme R; Kindt, Nadège; Decaestecker, Christine; Remmelink, Myriam; Larsimont, Denis; Andry, Guy; Hassid, Samantha; Rodriguez, Alexandra; Khalife, Mohammad; Journe, Fabrice; Saussez, Sven

    2016-10-01

    Despite the advent of concomitant chemoradiotherapy (CCRT), the prognosis of advanced head and neck squamous cell carcinoma (HNSCC) patients remains particularly poor. Classically, HNSCC, especially oropharyngeal carcinomas, associated with human papillomavirus (HPV) exhibits better treatment outcomes than HNSCCs in non-infected patients, eliciting a call for the de-escalation of current therapies. To improve the management of HNSCC patients, we aimed to determine the impact of active HPV infection on patient response, recurrence and survival after CCRT in a population of heavy tobacco and alcohol consumers. Paraffin-embedded samples from 218 advanced HNSCC patients, mostly smokers and/or drinkers treated by CCRT, were tested for the presence of HPV DNA by surrogate type-specific E6/E7 qPCR and p16 immunohistochemistry. Associations between the response to CCRT and patient outcomes according to HPV status and clinical data were evaluated by Kaplan-Meier analysis and both univariate and multivariate Cox regression. Type-specific E6/E7 PCR demonstrated HPV positivity in 20 % of HNSCC. Regarding HPV status, we did not find any significant relation with response to therapy in terms of progression-free survival or overall survival. However, we observed a significantly worse prognosis for consumers of alcohol and tobacco compared to nondrinkers (p = 0.003) and non-smokers (p = 0.03). Survival analyses also revealed that the outcome is compromised in stage IV patients (p = 0.007) and, in particular, for oral cavity, hypopharynx and oropharynx carcinoma patients (p = 0.001). The risk of death from HNSCC significantly increases when patients are exposed to tobacco and alcohol during their therapy, regardless of HPV status.

  20. Risk Factors for Hearing Loss in Patients Treated With Intensity-Modulated Radiotherapy for Head-and-Neck Tumors

    SciTech Connect

    Zuur, Charlotte L.; Dreschler, Wouter A.; Balm, Alfons J.; Rasch, Coen R.

    2009-06-01

    Purpose: Radiotherapy (RT) is a common treatment of head-and-neck carcinoma. The objective of this study was to perform a prospective multivariate assessment of the dose-effect relationship between intensity-modulated RT and hearing loss. Methods and Materials: Pure tone audiometry at 0.250-16 kHz was obtained before and after treatment in 101 patients (202 ears). All patients received full-course intensity-modulated RT (range, 56-70 Gy), with a median cochlear dose of 11.4 Gy (range, 0.2-69.7). Results: Audiometry was performed 1 week before and a median of 9 weeks (range, 1-112) after treatment. The mean hearing deterioration at pure tone average air-conduction 1-2-4 kHz was small (from 28.6 dB HL to 30.1 dB HL). However, individual patients showed clinically significant hearing loss, with 10-dB threshold shift incidences of 13% and 18% at pure tone averages air-conduction 1-2-4 kHz and 8-10-12.5 kHz, respectively. Post-treatment hearing capability was unfavorable in the case of greater inner ear radiation doses (p <0.0001), unfavorable baseline hearing capability (p <0.0001), green-eyed patients (p <0.0001), and older age (p <0.0001). Using multivariate analysis, a prediction of individual hearing capabiltity after treatment was made. Conclusion: RT-induced hearing loss in the mean population is modest. However, clinically significant hearing loss was observed in older patients with green eyes and unfavorable pretreatment hearing. In these patients, the intended radiation dose may be adjusted according to the proposed predictive model, aiming to decrease the risk of ototoxicity.

  1. Prevalence of Nontraumatic Osteonecrosis of the Femoral Head and its Associated Risk Factors in the Chinese Population: Results from a Nationally Representative Survey.

    PubMed

    Zhao, De-Wei; Yu, Mang; Hu, Kai; Wang, Wei; Yang, Lei; Wang, Ben-Jie; Gao, Xiao-Hong; Guo, Yong-Ming; Xu, Yong-Qing; Wei, Yu-Shan; Tian, Si-Miao; Yang, Fan; Wang, Nan; Huang, Shi-Bo; Xie, Hui; Wei, Xiao-Wei; Jiang, Hai-Shen; Zang, Yu-Qiang; Ai, Jun; Chen, Yuan-Liang; Lei, Guang-Hua; Li, Yu-Jin; Tian, Geng; Li, Zong-Sheng; Cao, Yong; Ma, Li

    2015-11-05

    Nontraumatic osteonecrosis of the femoral head (NONFH) is a debilitating disease that represents a significant financial burden for both individuals and healthcare systems. Despite its significance, however, its prevalence in the Chinese general population remains unknown. This study aimed to investigate the prevalence of NONFH and its associated risk factors in the Chinese population. A nationally representative survey of 30,030 respondents was undertaken from June 2012 to August 2013. All participants underwent a questionnaire investigation, physical examination of hip, and bilateral hip joint X-ray and/or magnetic resonance imaging examination. Blood samples were taken after overnight fasting to test serum total cholesterol, triglyceride, and high-density lipoprotein (HDL) and low-density lipoprotein (LDL) levels. We then used multivariate logistic regression analysis to investigate the associations between various metabolic, demographic, and lifestyle-related variables and NONFH. NONFH was diagnosed in 218 subjects (0.725%) and the estimated NONFH cases were 8.12 million among Chinese people aged 15 years and over. The prevalence of NONFH was significantly higher in males than in females (1.02% vs. 0.51%, χ2 = 24.997, P < 0.001). Among NONFH patients, North residents were subjected to higher prevalence of NONFH than that of South residents (0.85% vs. 0.61%, χ 2 = 5.847, P = 0.016). Our multivariate regression analysis showed that high blood levels of triglycerides, total cholesterol, LDL-cholesterol, and non-HDL-cholesterol, male, urban residence, family history of osteonecrosis of the femoral head, heavy smoking, alcohol abuse and glucocorticoid intake, overweight, and obesity were all significantly associated with an increased risk of NONFH. Our findings highlight that NONFH is a significant public health challenge in China and underscore the need for policy measures on the national level. Furthermore, NONFH shares a number of risk factors with

  2. Head Start.

    ERIC Educational Resources Information Center

    Greenman, Geri

    2000-01-01

    Discusses an art project in which students created drawings of mop heads. Explains that the approach of drawing was more important than the subject. States that the students used the chiaroscuro technique, used by Rembrandt and Caravaggio, in which light appears out of the darkness. (CMK)

  3. Cone Heads

    ERIC Educational Resources Information Center

    Coy, Mary

    2005-01-01

    The author, a middle school art teacher, describes a sculpture project lesson involving Cone Heads (sculptures made from cardboard cones). Discussion of caricatures with exaggerated facial features and interesting profiles helped students understand that the more expressive the face, the better. This project took approximately four to five…

  4. Magnetic Heads

    NASA Astrophysics Data System (ADS)

    Yokoshima, Tokihiko

    Figure 6.1 shows how rapidly the areal density of hard disk drives (HDD) has been increasing over the past 20 years [1]. Several critical innovations were necessary to bring about such rapid progress in the field of magnetic recording [2]. One of the most significant innovations from the viewpoint of material improvement was the electrodeposition of permalloy (Ni80Fe20), which was introduced by IBM in 1979 as the core material of a thin-film inductive head to increase the magnetic recording density [3]. After the introduction of the magneto-resistive (MR) element as the read head and the electrodeposited permalloy as the write head by IBM in 1991 [4], the rate of increase in the recording density of HDDs jumped from 30% per year to 60% per year. Recently, a giant magneto-resistive (GMR) element has been used for the read element instead of the MR element. The rate of increase in the recording density jumped to over 100% per year in 1999, which is an incredible rate of increase. Since 2002, however, the rate of increase has decreased to 30%; thus, new innovations are required to maintain the rate of increase. In 2004, the practical use of perpendicular magnetic recording instead of longitudinal magnetic recording was announced [5]. This system is a critical innovation for developing high-performance HDD systems with high-recording density. The design of the magnetic recording head was changed because of the change of the recording system.

  5. Gelsolin-mediated activation of PI3K/Akt pathway is crucial for hepatocyte growth factor-induced cell scattering in gastric carcinoma

    PubMed Central

    Huang, Baohua; Deng, Shuo; Loo, Ser Yue; Datta, Arpita; Yap, Yan Lin; Yan, Benedict; Ooi, Chia Huey; Dinh, Thuy Duong; Zhuo, Jingli; Tochhawng, Lalchhandami; Gopinadhan, Suma; Jegadeesan, Tamilarasi; Tan, Patrick; Salto-Tellez, Manuel; Yong, Wei Peng; Soong, Richie; Yeoh, Khay Guan; Goh, Yaw Chong; Lobie, Peter E.; Yang, Henry; Kumar, Alan Prem; Maciver, Sutherland K.; So, Jimmy B.Y.; Yap, Celestial T.

    2016-01-01

    In gastric cancer (GC), the main subtypes (diffuse and intestinal types) differ in pathological characteristics, with diffuse GC exhibiting early disseminative and invasive behaviour. A distinctive feature of diffuse GC is loss of intercellular adhesion. Although widely attributed to mutations in the CDH1 gene encoding E-cadherin, a significant percentage of diffuse GC do not harbor CDH1 mutations. We found that the expression of the actin-modulating cytoskeletal protein, gelsolin, is significantly higher in diffuse-type compared to intestinal-type GCs, using immunohistochemical and microarray analysis. Furthermore, in GCs with wild-type CDH1, gelsolin expression correlated inversely with CDH1 gene expression. Downregulating gelsolin using siRNA in GC cells enhanced intercellular adhesion and E-cadherin expression, and reduced invasive capacity. Interestingly, hepatocyte growth factor (HGF) induced increased gelsolin expression, and gelsolin was essential for HGF-medicated cell scattering and E-cadherin transcriptional repression through Snail, Twist and Zeb2. The HGF-dependent effect on E-cadherin was found to be mediated by interactions between gelsolin and PI3K-Akt signaling. This study reveals for the first time a function of gelsolin in the HGF/cMet oncogenic pathway, which leads to E-cadherin repression and cell scattering in gastric cancer. Our study highlights gelsolin as an important pro-disseminative factor contributing to the aggressive phenotype of diffuse GC. PMID:27058427

  6. Gelsolin-mediated activation of PI3K/Akt pathway is crucial for hepatocyte growth factor-induced cell scattering in gastric carcinoma.

    PubMed

    Huang, Baohua; Deng, Shuo; Loo, Ser Yue; Datta, Arpita; Yap, Yan Lin; Yan, Benedict; Ooi, Chia Huey; Dinh, Thuy Duong; Zhuo, Jingli; Tochhawng, Lalchhandami; Gopinadhan, Suma; Jegadeesan, Tamilarasi; Tan, Patrick; Salto-Tellez, Manuel; Yong, Wei Peng; Soong, Richie; Yeoh, Khay Guan; Goh, Yaw Chong; Lobie, Peter E; Yang, Henry; Kumar, Alan Prem; Maciver, Sutherland K; So, Jimmy B Y; Yap, Celestial T

    2016-05-03

    In gastric cancer (GC), the main subtypes (diffuse and intestinal types) differ in pathological characteristics, with diffuse GC exhibiting early disseminative and invasive behaviour. A distinctive feature of diffuse GC is loss of intercellular adhesion. Although widely attributed to mutations in the CDH1 gene encoding E-cadherin, a significant percentage of diffuse GC do not harbor CDH1 mutations. We found that the expression of the actin-modulating cytoskeletal protein, gelsolin, is significantly higher in diffuse-type compared to intestinal-type GCs, using immunohistochemical and microarray analysis. Furthermore, in GCs with wild-type CDH1, gelsolin expression correlated inversely with CDH1 gene expression. Downregulating gelsolin using siRNA in GC cells enhanced intercellular adhesion and E-cadherin expression, and reduced invasive capacity. Interestingly, hepatocyte growth factor (HGF) induced increased gelsolin expression, and gelsolin was essential for HGF-medicated cell scattering and E-cadherin transcriptional repression through Snail, Twist and Zeb2. The HGF-dependent effect on E-cadherin was found to be mediated by interactions between gelsolin and PI3K-Akt signaling. This study reveals for the first time a function of gelsolin in the HGF/cMet oncogenic pathway, which leads to E-cadherin repression and cell scattering in gastric cancer. Our study highlights gelsolin as an important pro-disseminative factor contributing to the aggressive phenotype of diffuse GC.

  7. [Analyses of clinicopathologic factors affecting neck control after postoperative radiation as adjuvant treatment for lymph node metastasis in head and neck squamous cell carcinoma].

    PubMed

    Di, B; Li, X M; Zhang, J J; Liu, S; Song, Q; Tao, Z F; Fan, C

    2016-07-07

    To investigate the clinicopathologic factors associated with neck control and distant metastasis in patients with neck metastases in head and neck squamous cell carcinoma (HNSCC) after postoperative radiation as adjuvant treatment. Clinicopathologic data of 208 pathologic N+ (pN+ ) patients with HNSCC initially treated with neck dissection and postoperative radiation in Bethune International Peace Hospital of China from January 2004 to December 2009 were reviewed. The clinicopathologic factors, includeding age, sex, primary tumor site, pathologic T and N stage, tumor growth pattern, histological grade, tumor resection margin, size and number of positive lymph node, number of levels with positive lymph node, and extracapsular nodal spread (ECS), were evaluated for their association with neck control and distant metastasis in patients with HNSCC after postoperative radiation. Univariate χ(2) test and multiple stepwise logistic regression model were used for the analysis. Overall 5-year neck control rate after postoperative radiotherapy was 72.6% (151/208), with 84.0% (63/75) for SND, 72.9% (78/107) for MRND, and 38.5% (10/26) for RND, respectively. Univariate analysis showed that neck control after postoperative radiation was related with following factors: primary tumor site, pathologic N stage, size of positive node, number of levels with positive node, number of positive node, and ECS. Pathologic N stage and number of levels with positive lymph node were associated with distant metastasis. Multivariate analysis indicated that ECS was the most significant risk factor for neck metastasis after surgery and postoperative radiotherapy and the number of levels with positive node was the most significant risk factor for distant metastasis. ECS is the most important pathologic factor in planning postoperative adjuvant treatment for pN+ patients with HNSCC, therefore ECS should be evaluated routinely after neck dissection. The value of postoperative radiotherapy in

  8. Electromagnetic Enhancement Factor of Surface-enhanced Raman Scattering of Rh6G Molecules on Au Nanoparticles

    NASA Astrophysics Data System (ADS)

    Seo, Jaetae; Kim, Wanjoong; Jung, Sungsoo

    2009-05-01

    Surface-enhanced Raman spectroscopy (SERS) of molecules on nanometals has been intensively studied for technical application of bio-chemical sensing. Among physical origins of SERS enhancement, the electromagnetic effect is the most fundamental contribution of SERS enhancement. Relevant REF of C-C stretching mode of Rh6G near 1511 cm-1 was shown two-order enhancement with 5-nm Au colloidal nanoparticles. The REF was greatly enhanced up to ˜six orders with ˜35 nm Au particles, and was enhanced ˜five orders with 40-nm Au nanoparticles. The reduction of REF with smaller sizes is possibly due to the scattering of conduction electrons on particles surfaces; that with larger sizes is probably due to tips or complex structures. This work at Hampton University was supported by the National Science Foundation (HRD-0734635, HRD-0630372, and ESI-0426328/002) and the U.S. Army Research Office (W911NF-07-1-0608).

  9. Asymptotic behavior of the deuteron form factors in the two-nucleon model and electron scattering experiments at GeV energies at JLab

    SciTech Connect

    Krutov, A. F.; Tsirova, N. A.; Troitsky, V. E.

    2008-10-15

    Using the instant form dynamics of Poincare invariant quantum mechanics and the modified relativistic impulse approximation proposed previously, we calculate asymptotic behavior of electromagnetic form factors for the deuteron considered as a two-nucleon system. We show that today, experimentation on elastic ed scattering has reached the asymptotic regime. We also estimate the possible range of momentum transfer in which the quark degrees of freedom will possibly be seen in future JLab experiments. The explicit relation between the behavior of the deuteron wave function at r=0 and the form factors asymptotic behavior is obtained, and the conditions of wave functions that give the asymptotic behavior predicted by QCD and quark counting rules are formulated.

  10. CORRECTION FACTORS FOR ATTENUATION AND SCATTERING OF THE WALL OF A CYLINDRICAL IONIZATION CHAMBER IN THE 6-7 MeV HIGH-ENERGY PHOTON REFERENCE FIELD.

    PubMed

    Kowatari, M; Zutz, H; Hupe, O

    2017-06-07

    In high-energy photon reference fields the value of the air kerma rate is determined by using ionization chambers (ICs). From the charge collected inside the IC the dose can be calculated using a set of calibration and correction factors according to ISO 4037-2. A crucial parameter is the correction for the attenuation and scattering of the primary radiation due to the chamber wall. This parameter can be determined using Monte Carlo calculations. The evaluation of the factor was performed for a commercially available IC of the type Victoreen 550-3 under different build-up conditions. The results were verified by measurements in the R-F high-energy photon fields according to ISO 4037-1 at the Physikalisch-Technische Bundesanstalt (PTB) and the Japan Atomic Energy Agency (JAEA). © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Adolescent motherhood and developmental outcomes of children in early head start: the influence of maternal parenting behaviors, well-being, and risk factors within the family setting.

    PubMed

    Rafferty, Yvonne; Griffin, Kenneth W; Lodise, Michelle

    2011-04-01

    This longitudinal study examined the influence of parenting behaviors, well-being, and risk factors of low-income adolescent mothers on the cognitive and language abilities of children from infancy to age 3. Participants consisted of 1,240 mother-child dyads enrolled in the Early Head Start Research and Evaluation Project. Data were collected using structured interviews with the mothers and from videotaped mother-child interactions during play activities when children were approximately 14 months old and again at 36 months of age. Positive parenting behaviors exhibited toward the 14-month-old children predicted gains in both cognitive and language abilities more so than did maternal well-being, risk factors within the family setting, and demographic risk factors. Gains in cognitive abilities from infancy to age 3 were predicted by supportive parenting, higher family resources, and lower family conflict when children were infants. Gains in language abilities were predicted by supportive parenting, support for language and learning in the home environment, and higher family resources when children were infants. Finally, path analyses showed that maternal age had an indirect effect on child cognitive and language abilities at age 3 through effects on parenting behaviors. Older mothers were more likely to be supportive during play at age 14 months, which in turn promoted enhanced developmental outcomes at age 3. Implications for intervention and future research are discussed.

  12. Factors associated with healthcare professional's rating of disfigurement and self-perceived body image in female patients with head and neck cancer.

    PubMed

    Chen, S-C; Huang, C-Y; Huang, B-S; Lin, C-Y; Fan, K-H; Chang, J T-C; Wu, S-C; Lai, Y-H

    2017-05-09

    The purpose of this study was to determine factors associated with self-perceived body image in female patients with head and neck cancer (HNC), and factors associated with healthcare professional's rating of disfigurement, as well as the correlation between patient and observer ratings. This cross-sectional study recruited 105 women with HNC at a large medical centre. Measures of facial disfigurement and body image, as well as demographic and clinical characteristics, were collected. Multivariate multiple linear regression modelling was used to identify factors associated with healthcare professional's rating of disfigurement and patient self-perceived body image. Disfigurement ratings by healthcare professionals were positively associated with patient self-perceived body image. Medical treatment, cancer stage, radiation dose and cancer site were significantly associated with disfigurement. Medical treatment was an important predictor of perceived body image. These findings indicate a moderate prevalence of disfigurement among women with HNCs. Patients with more disfigurement were more likely to have dissatisfaction with their body image. Nursing professionals need to carefully assess the appearance of women with HNC. Camouflage interventions can be used to help appropriately cope with the disfigurement, and to achieve improved satisfaction with their body image. © 2017 John Wiley & Sons Ltd.

  13. Alteration of the serum levels of the epidermal growth factor receptor and its ligands in patients with non-small cell lung cancer and head and neck carcinoma.

    PubMed

    Lemos-González, Y; Rodríguez-Berrocal, F J; Cordero, O J; Gómez, C; Páez de la Cadena, M

    2007-05-21

    Serum levels of the soluble epidermal growth factor receptor (sEGFR) and its ligands epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha) and amphiregulin (AR) were measured in healthy donors and patients with non-small cell lung cancer (NSCLC) and head and neck carcinoma (HNC). In NSCLC, we found sEGFR and EGF levels significantly lowered in patients with respect to healthy donors. In HNC patients, significantly diminished levels were found in the case of sEGFR, EGF and also AR. In both malignancies, no significant association was found between the serum levels of the molecules and the patients' gender, age or smoking habit. Only a significant association was found between the decrease of sEGFR and the absence of distant metastasis in NSCLC and the tumour stage in HNC. The most interesting result was that combining sEGFR and EGF, sensitivities of 88% in NSCLC and 100% in HNC were reached without losing specificity (97.8% in both cases). The use of discriminant analysis and logistic regression improved the sensitivity for NSCLC and the specificity for HNC. These data demonstrate a potentially interesting value of the serum levels of sEGFR and EGF, especially when combined, as markers for NSCLC and HNC.

  14. DAF-16/Forkhead Box O Transcription Factor: Many Paths to a Single Fork(head) in the Road

    PubMed Central

    Yen, Kelvin; Narasimhan, Sri Devi

    2011-01-01

    Abstract The Caenorhabditis elegans Forkhead box O transcription factor (FOXO) homolog DAF-16 functions as a central mediator of multiple biological processes such as longevity, development, fat storage, stress resistance, and reproduction. In C. elegans, similar to other systems, DAF-16 functions as the downstream target of a conserved, well-characterized insulin/insulin-like growth factor (IGF)-1 signaling pathway. This cascade is comprised of an insulin/IGF-1 receptor, which signals through a conserved PI 3-kinase/AKT pathway that ultimately downregulates DAF-16/FOXO activity. Importantly, studies have shown that multiple pathways intersect with the insulin/IGF-1 signaling pathway and impinge on DAF-16 for their regulation. Therefore, in C. elegans, the single FOXO family member, DAF-16, integrates signals from several pathways and then regulates its many downstream target genes. Antioxid. Redox Signal. 14, 623–634. PMID:20673162

  15. Treatment factors influencing the use of recombinant platelet-derived growth factor (Regranex) for head and lateral line erosion syndrome in ocean surgeonfish (Acanthurus bahianus).

    PubMed

    Fleming, Gregory J; Corwin, Allison; McCoy, A Jeanene; Stamper, M Andrew

    2008-06-01

    The clinical efficacy of becaplermin (Regranex, Ortho-McNeil Pharmaceutical, Inc., Raritan, New Jersey 08869) on head and lateral line erosion syndrome (HLLES) in ocean surgeonfish (Acanthurus bahianus) was examined in a two-part study to determine suitable application frequencies of the drug and the effects of the environment on outcome of treatments. In the first part of the study, 12 ocean surgeonfish with prior HLLES were equally divided into three treatment groups, varying in application frequency of becaplermin: 1) one application, 2) three applications every 3 wk, and 3) no applications. After 9 wk, it was determined through photograph and computer analysis that fish treated with becaplermin did heal significantly more than the fish that were not treated. No significant difference was found when comparing the two treatment regimes; therefore, a one-time treatment of becaplermin was just as effective as the three-time application, reducing cost of the treatment, staff labor, and stress to the animals. In the second part of the study, the effect of the water environment on HLLES development was documented before and after a one-time treatment of becaplermin. When fish were treated and placed into a system known to cause HLLES, the becaplermin treatment had no effect on reducing the HLLES progression, whereas treated fish that were placed into a system that did not cause HLLES showed a significant decrease in erosion after the treatment. Therefore, treating fish being placed into a HLLES-causing system serves no beneficial purpose to healing HLLES.

  16. The Head-Injured College Student.

    ERIC Educational Resources Information Center

    Holmes, Cooper B.

    Intended for use by professionals as well as head-injured college students and their families, the text provides basic information about head injuries, brain anatomy, the effects of injury to the various areas of the brain, and the major factors in recovery and rehabilitation. It examines the viability of college attendance for the head-injured…

  17. The Head-Injured College Student.

    ERIC Educational Resources Information Center

    Holmes, Cooper B.

    Intended for use by professionals as well as head-injured college students and their families, the text provides basic information about head injuries, brain anatomy, the effects of injury to the various areas of the brain, and the major factors in recovery and rehabilitation. It examines the viability of college attendance for the head-injured…

  18. RISK-FACTORS, PATHOGENESIS, AND PHARMACEUTICAL APPROACHES FOR TREATMENT OF STEROID-INDUCED BONE INFARCTION OF FEMORAL HEAD.

    PubMed

    Wang, Fei; Wang, Yang; Hu, Ningning; Miao, Xuman

    2016-01-01

    During first year of steroid usage, osteocyte necrosis and blood vessel blockage may occur, which subsequently may produce steroid-induced bone infarction (SIBI) resulting in painful movement of patient. For treatment of SIBI, pharmaceutical strategy is the basic approach. It involves the use of various pharmacologically active compounds including bisphosphonates, hyperbaric oxygen (HBO), coenzyme Q10, erythropoietin, antihyperlipidemics, anticoagulants, antioxidants, and tissue repair protein. Out of these, there is no pharmaceutical agent that may completely treat this disease because many factors are found to be responsible for SIBI development; therefore, there are multiple biomarkers of this disease. This situation argues for need of new therapeutic agents for SIEB1.

  19. Prognosis in head injury.

    PubMed

    Jane, J A; Rimel, R W

    1982-01-01

    The prognosis of head injury when viewed from the perspective of the Glasgow Coma Scale confirms the utility of this measure. In particular, decrease in mortality is associated with an increase in GCS. In addition, the motor score portion of the GCS was of predictive value when taken alone. The outcome of patients in coma (GCS less than 8) was closely related to three preventable or treatable factors, namely, hypoxia, shock, and increased intracranial pressure. These three factors, when considered in combination, powerfully predicted mortality. Of considerable interest was the finding that moderate head injury (GCS 9-12) was associated with a small but perhaps preventable mortality. The morbidity was intermediate between that of severe and minor and was surprisingly high. Minor head injury, while not associated with significant mortality, also resulted in considerable morbidity. Neuropsychological evaluation of the patients and an experimental study suggests that an organic component may be involved even in this group. To deal with head injury, distinctions must be made between grades of severity. The Glasgow Coma Scale is suited for this task. Nonetheless, the recognition of this basic continuity should elicit the further recognition that different health providers may be involved in the case of, say, severe, as opposed to mild, injury, and that different outcome measures are suitable for one group but not another.

  20. PD-L1 expression on immune cells, but not on tumor cells, is a favorable prognostic factor for head and neck cancer patients

    PubMed Central

    Kim, Hye Ryun; Ha, Sang-Jun; Hong, Min Hee; Heo, Su Jin; Koh, Yoon Woo; Choi, Eun Chang; Kim, Eun Kyung; Pyo, Kyoung Ho; Jung, Inkyung; Seo, Daekwan; Choi, Jaewoo; Cho, Byoung Chul; Yoon, Sun Och

    2016-01-01

    To investigate the expression of programmed death-ligand 1 (PD-L1) and immune checkpoints and their prognostic value for resected head and neck squamous cell cancer (HNSCC). PD-L1 expression on tumor cells (TC) and tumor-infiltrating immune cells (IC), abundance of tumor-infiltrating lymphocytes (TILs), and expression of the immune checkpoints were investigated in 402 HNSCC patients. PD-L1 expression on TC and IC was categorized into four groups according to the percentage of PD-L1-positive cells. PD-L1 positivity was defined as ≥5% of cells based on immunohistochemistry. High PD-L1 expression on IC, but not TC, was an independent favorable prognostic factor for RFS and OS adjusted for age, gender, smoking, stage, and HPV. High frequencies of CD3+ or CD8+ TILs, Foxp3+ Tregs, and PD-1+ TILs were strongly associated with favorable prognosis. PD-L1 was exclusively expressed on either TC or IC. Transcriptome analysis demonstrated that IC3 expressed higher levels of the effector T cell markers than TC3, suggesting that PD-L1 expression is regulated via an adaptive IFNγ-mediated mechanism. High PD-L1 expression on IC, but not TC, and high abundance of PD-1+ T cells and Foxp3+ Tregs are favorable prognostic factors for resected HNSCC. This study highlights the importance of comprehensive assessment of both TC and IC. PMID:27841362

  1. Evaluation of incidence, significance, and prognostic role of circulating tumor microemboli and transforming growth factor-β receptor I in head and neck cancer.

    PubMed

    Fanelli, Marcello Ferretti; Oliveira, Thiago Bueno; Braun, Alexcia Camila; Corassa, Marcelo; Abdallah, Emne Ali; Nicolau, Ulisses Ribaldo; da Silva Alves, Vanessa; Garcia, Daniel; Calsavara, Vinicius F; Kowalski, Luiz Paulo; Chinen, Ludmilla Thomé Domingos

    2017-08-17

    Circulating tumor microemboli (CTM) are clusters of circulating tumor cells (CTCs), involved in metastasis, as also transforming growth factor-β (TGF-β). The purpose of this study was to verify their role in progression-free survival (PFS). Blood from patients with locally advanced head and neck squamous cell carcinoma (HNSCC; n = 53) was analyzed in 2 moments. TGF-β receptor I (TGF-βRI) expression was evaluated by immunocytochemistry. Comparing CTM1 (baseline) with CTM2 (first follow-up), patients with CTM1-positive disease who became CTM2-negative were classified as favorable (PFS 20 months). Patients with unfavorable evolution (CTM1-negative/CTM2-positive), had PFS of 17.5 months. Patients always CTM-negative showed PFS of 22.4 months, those always positive, 4.7 months (P < .001). The TGF-βRI expression in the first follow-up correlated with poor PFS (12 × 26 months; P = .007), being an independent prognostic factor (hazard ratio [HR] = 6.088; P =  .033). CTM1/2, TGF-βRI expression, and unfavorable CTM kinetics may represent poor prognosis in locally advanced HNSCC. © 2017 Wiley Periodicals, Inc.

  2. High Surface-Enhanced Raman Scattering (SERS) Amplification Factor Obtained with Silver Printed Circuit Boards and the Influence of Phenolic Resins for the Characterization of the Pesticide Thiram.

    PubMed

    Silva de Almeida, Francylaine; Bussler, Larissa; Marcio Lima, Sandro; Fiorucci, Antonio Rogério; da Cunha Andrade, Luis Humberto

    2016-07-01

    In this work, low-cost substrates with rough silver surfaces were prepared from commercial copper foil-covered phenolic board (CPB) and an aqueous solution of AgNO3, and were used for surface-enhanced Raman scattering (SERS) and surface-enhanced resonance Raman scattering (SERRS) measurements. A maximum SERS amplification factor of 1.2 × 10(7) was obtained for Rhodamine 6G (R6G), and use of the CPB resulted in a detection limit for Thiram pesticide of 0.5 µmol L(-1) The minimum detection level was limited by residual traces of phenolic groups that originated from the substrate resin, which became solubilized in the aqueous Ag(+) solution. It was found that the bands corresponding to the impurities had less influence in the Thiram analysis, which could be explained by the high affinity of sulfur for Ag surfaces. The influence of impurities in the SERS analyses therefore depended on the linkage between the rough silver surface and the analyte. The findings demonstrated the ease and effectiveness of using CPB to prepare a nanostructured surface for SERS.

  3. Irradiation-Induced Regulation of Plasminogen Activator Inhibitor Type-1 and Vascular Endothelial Growth Factor in Six Human Squamous Cell Carcinoma Lines of the Head and Neck

    SciTech Connect

    Artman, Tuuli; Schilling, Daniela; Multhoff, Gabriele

    2010-02-01

    Purpose: It has been shown that plasminogen activator inhibitor type-1 (PAI-1) and vascular endothelial growth factor (VEGF) are involved in neo-angiogenesis. The aim of this study was to investigate the irradiation-induced regulation of PAI-1 and VEGF in squamous cell carcinomas of the head and neck (SCCHN) cell lines of varying radiation sensitivity. Methods and Materials: Six cell lines derived from SCCHN were investigated in vitro. The colorimetric AlamarBlue assay was used to detect metabolic activity of cell lines during irradiation as a surrogate marker for radiation sensitivity. PAI-1 and VEGF secretion levels were measured by enzyme-linked immunosorbent assay 24, 48, and 72 h after irradiation with 0, 2, 6, and 10 Gy. The direct radioprotective effect of exogenous PAI-1 was measured using the clonogenic assay. For regulation studies, transforming growth factor-beta1 (TGF-beta1), hypoxia-inducible factor-1alpha (HIF-1alpha), hypoxia-inducible factor-2alpha (HIF-2alpha), or both HIF-1alpha and HIF-2alpha were downregulated using siRNA. Results: Although baseline levels varied greatly, irradiation led to a comparable dose-dependent increase in PAI-1 and VEGF secretion in all six cell lines. Addition of exogenous stable PAI-1 to the low PAI-1-expressing cell lines, XF354 and FaDu, did not lead to a radioprotective effect. Downregulation of TGF-beta1 significantly decreased VEGF secretion in radiation-sensitive XF354 cells, and downregulation of HIF-1alpha and HIF-2alpha reduced PAI-1 and VEGF secretion in radiation-resistant SAS cells. Conclusions: Irradiation dose-dependently increased PAI-1 and VEGF secretion in all SCCHN cell lines tested regardless of their basal levels and radiation sensitivity. In addition, TGF-beta1 and HIF-1alpha could be partly responsible for VEGF and PAI-1 upregulation after irradiation.

  4. SU-E-T-246: MU Model Implementation for a Passively Scattered Proton Beam: Inclusion of the Bolus Gap and Nozzle Extension Factors

    SciTech Connect

    Simpson, R; Ghebremedhin, A; Gordon, I; Patyal, B; Piskulich, F.; LeMaster, Brett

    2014-06-01

    Purpose: To develop and implement an MU model for a passively scattered proton beam, and eliminate the need for patient specific calibrations for field sizes from 3cm to 15cm. This would enable consistent and timely calibrations for a wide variety of patient portals, streamlining the treatment process. Methods: Measurements were initially made using a Standard Imaging A-16 ion chamber and a modified water tank to determine the bolus gap factors (BGF) for multiple combinations of aperture size, bolus thickness, and air gap. The BGF was then separated into two component factors: the bolus thickness factor (BTF) and the nozzle extension factor (NEF). Polynomial curves were generated using the measured data to produce BTF tables for air gaps from 0cm to 30cm and for bolus thicknesses from 0cm to 10cm, and NEF tables for the full range of clinically used nozzle extensions. Additionally, data tables were created for every factor that affects beam output in the MU model. The MUs were then modeled for 487 patient portals and retrospectively compared to the MUs generated from the physical calibrations previously performed. Results: Of the 487 patient portals tested, 100% of the portals used for the comparison were within 2.5% from the MUs generated using a physical calibration, and 95.9% of the MU model portals tested were within 2%. The patient portals tested had field sizes ranging from 2.1cm to 10.1cm, with air gaps from 2cm to 25cm. Output factors for field sizes below 3cm with irregularly shaped fields demonstrated inconsistent results and will be further studied. Conclusion: The most problematic output factor, the BGF, was modeled accurately and consistently using the lowest order polynomial curve fits and interpolation between measured data. The study results demonstrate the robustness of the MU model and the potential for saving valuable personnel and beam time.

  5. Factors to Consider When Deciding on the Type of Free-Flap Reconstruction of Head and Neck Soft Tissue Defects.

    PubMed

    Aladimi, Mohammed Thabet; Han, Bo; Li, Chunjie; Helal, Hussein; Gao, Zhenjie; Li, Longjiang

    2017-01-01

    The aim of the study was to evaluate the functional and aesthetic outcomes on donor and recipient sites and to determine the effects of technical factors including flap thickness and vessel diameters measured by ultrasonography as well as the size of the defect and postoperative volume reduction of the flaps measured by magnetic resonance imaging (MRI). In patients who had undergone soft tissue reconstructive surgery between March 2013 and March 2016 using 55 anterolateral thigh flaps (ALTFs), 30 radial forearm flaps (RFFs), and 18 latissimus dorsi flaps (LDFs), color Doppler ultrasonography was performed to measure the thickness of the flap at the site of the perforator. Preoperative color Doppler ultrasound examinations of the blood vessel diameters of donor and recipient sites were carried out. 97.1% of flaps showed complete survival and 2.9% complete failure (2 ALTFs and 1 LDF). The difference in flap volume of ALTFs, RFFs, and LDFs between MRI 1 (3-6 weeks) and MRI 2 (6-18 months) was 27.6, 17.9, and 36.1%, respectively. Proper selection of the flap is important for the optimization of the aesthetic and functional outcomes. Ultrasound, the surgeon's experience and the extension and nature of the defect play a key role in the selection of the flap. © 2017 S. Karger AG, Basel.

  6. A Preliminary Report on X-Ray Photoabsorption Coefficients andAtomic Scattering Factors for 92 Elements in the 10-10,000 eVRegion

    SciTech Connect

    Henke, B.L.; Davis, J.C.; Gullikson, E.M.; Perera, R.C.C.

    1988-11-01

    Based on currently available photoabsorption measurements and recent theoretical calculations by Doolen and Liberman (Physica Scripta 36, 77 (1987)), a revised (from ADNDT 27, 1 (1982)) best-fit determination of the photoabsorption cross sections is presented here for the elements Z=1 to Z=92 in the 10-10,000 eV range. The photoabsorption data used include those described in the Lockheed and DOE listings of research abstracts for the past ten years and those which have been recently added to the comprehensive NBS Measured Data Base (NBSIR 86-3461, Hubbell et al.). The best-fit curves are compared with both the compilation of measurements and the calculations by Doolen and Liberman. Using the photoabsorption curves, the atomic scattering factors have been calculated for the energy range 50-10,000 eV and are also presented in this report.

  7. Inelastic electron scattering form factors involving the second excited 2+ levels in the nuclei 48Ti and 50Cr

    NASA Astrophysics Data System (ADS)

    Mukherjee, G.; Sharma, S. K.

    1985-02-01

    A microscopic description of the recent data on the Coulomb form factors for the 0g.s.+-->2+2 transitions in the nuclei 48Ti and 50Cr is attempted in terms of the prolate and oblate intrinsic states resulting from realistic effective interactions operating in the 2p-1f shell. The results for the higher momentum-transfer region show significant improvements compared to the form factor estimates obtained in some recent shell model calculations involving the fn7/2+fn-17/2p3/2 configurations.

  8. Microcavity Enhanced Raman Scattering

    NASA Astrophysics Data System (ADS)

    Petrak, Benjamin J.

    Raman scattering can accurately identify molecules by their intrinsic vibrational frequencies, but its notoriously weak scattering efficiency for gases presents a major obstacle to its practical application in gas sensing and analysis. This work explores the use of high finesse (≈50 000) Fabry-Perot microcavities as a means to enhance Raman scattering from gases. A recently demonstrated laser ablation method, which carves out a micromirror template on fused silica--either on a fiber tip or bulk substrates-- was implemented, characterized, and optimized to fabricate concave micromirror templates ˜10 mum diameter and radius of curvature. The fabricated templates were coated with a high-reflectivity dielectric coating by ion-beam sputtering and were assembled into microcavities ˜10 mum long and with a mode volume ˜100 mum 3. A novel gas sensing technique that we refer to as Purcell enhanced Raman scattering (PERS) was demonstrated using the assembled microcavities. PERS works by enhancing the pump laser's intensity through resonant recirculation at one longitudinal mode, while simultaneously, at a second mode at the Stokes frequency, the Purcell effect increases the rate of spontaneous Raman scattering by a change to the intra-cavity photon density of states. PERS was shown to enhance the rate of spontaneous Raman scattering by a factor of 107 compared to the same volume of sample gas in free space scattered into the same solid angle subtended by the cavity. PERS was also shown capable of resolving several Raman bands from different isotopes of CO2 gas for application to isotopic analysis. Finally, the use of the microcavity to enhance coherent anti-Stokes Raman scattering (CARS) from CO2 gas was demonstrated.

  9. Working memory units are all in your head: Factors that influence whether features or objects are the favored units.

    PubMed

    Vergauwe, Evie; Cowan, Nelson

    2015-09-01

    We compared two contrasting hypotheses of how multifeatured objects are stored in visual working memory (vWM); as integrated objects or as independent features. A new procedure was devised to examine vWM representations of several concurrently held objects and their features and our main measure was reaction time (RT), allowing an examination of the real-time search through features and/or objects in an array in vWM. Response speeds to probes with color, shape, or both were studied as a function of the number of memorized colored shapes. Four testing groups were created by varying the instructions and the way in which probes with both color and shape were presented. The instructions explicitly either encouraged or discouraged the use of binding information and the task-relevance of binding information was further suggested by presenting probes with both color and shapes as either integrated objects or independent features. Our results show that the unit used for retrieval from vWM depends on the testing situation. Search was fully object-based only when all factors support that basis of search, in which case retrieving 2 features took no longer than retrieving a single feature. Otherwise, retrieving 2 features took longer than retrieving a single feature. Additional analyses of change detection latency suggested that, even though different testing situations can result in a stronger emphasis on either the feature dimension or the object dimension, neither one disappears from the representation and both concurrently affect change detection performance. (c) 2015 APA, all rights reserved).

  10. Working Memory Units are All in Your Head: Factors that Influence Whether Features or Objects Are the Favored Units

    PubMed Central

    Vergauwe, Evie; Cowan, Nelson

    2015-01-01

    We compared two contrasting hypotheses of how multi-featured objects are stored in visual working memory (vWM): as integrated objects or as independent features. A new procedure was devised to examine vWM representations of several concurrently-held objects and their features and our main measure was reaction time (RT), allowing an examination of the real-time search through features and/or objects in an array in vWM. Response speeds to probes with color, shape or both were studied as a function of the number of memorized colored shapes. Four testing groups were created by varying the instructions and the way in which probes with both color and shape were presented. The instructions explicitly either encouraged or discouraged the use of binding information and the task-relevance of binding information was further suggested by presenting probes with both color and shapes as either integrated objects or independent features. Our results show that the unit used for retrieval from vWM depends on the testing situation. Search was fully object-based only when all factors support that basis of search, in which case retrieving two features took no longer than retrieving a single feature. Otherwise, retrieving two features took longer than retrieving a single feature. Additional analyses of change detection latency suggested that, even though different testing situations can result in a stronger emphasis on either the feature dimension or the object dimension, neither one disappears from the representation and both concurrently affect change detection performance. PMID:25705873

  11. Risk Factors of Ototoxicity After Cisplatin-Based Chemo-Irradiation in Patients With Locally Advanced Head-and-Neck Cancer: A Multivariate Analysis

    SciTech Connect

    Zuur, Charlotte L. . E-mail: cl.zuur@vumc.nl; Simis, Yvonne J.; Lansdaal, Pauline E.; Hart, Augustinus A.; Rasch, Coen R.; Schornagel, Jan H.; Dreschler, Wouter A.; Balm, Alfons J.

    2007-08-01

    Purpose: Cisplatin chemo-irradiation is increasingly used in locally advanced squamous cell carcinoma of the head and neck. The objective of this study is to determine risk factors of ototoxicity due to intra-arterial high-dose cisplatin chemoradiation. Methods and Materials: A prospective analysis of hearing thresholds at low and (ultra) high frequencies obtained before, during, and after treatment in 146 patients. Treatment consisted of intra-arterial infusion of high-dose cisplatin (150 mg/m{sup 2}, four courses) with sodium thiosulfate rescue and concurrent radiation therapy (70 Gy). Patient and chemoradiation variables were studied in a multivariate analysis. Results: After treatment, 23% of the ears were under consideration for hearing aids because of therapy. Twenty-two percent of the patients developed an increase in air-bone gap >10 dB during or after therapy. In the multivariate explanatory analysis, cumulative dose of cisplatin and radiation therapy, and young age displayed a causal relationship with increased sensorineural hearing loss during and after therapy (p < 0.001). In the multivariate prediction analysis, pretreatment hearing level of the concerning ear was identified as an independent predictive factor for hearing capability after therapy (p < 0.0001). Conclusions: Both cisplatin and radiation therapy were proven to induce sensorineural hearing loss, in this study with short-term follow-up. Of all patient and treatment variables studied, the patients pretreatment hearing level appeared to be the main predictive factor for hearing capability after high-dose intra-arterial cisplatin chemoradiation.

  12. Lidar multiple scattering factors inferred from CALIPSO lidar and IIR retrievals of semi-transparent cirrus cloud optical depths over oceans

    NASA Astrophysics Data System (ADS)

    Garnier, A.; Pelon, J.; Vaughan, M. A.; Winker, D. M.; Trepte, C. R.; Dubuisson, P.

    2015-07-01

    Cirrus cloud absorption optical depths retrieved at 12.05 μm are compared to extinction optical depths retrieved at 0.532 μm from perfectly co-located observations of single-layered semi-transparent cirrus over ocean made by the Imaging Infrared Radiometer (IIR) and the Cloud and Aerosol Lidar with Orthogonal Polarization (CALIOP) flying on board the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) satellite. IIR infrared absorption optical depths are compared to CALIOP visible extinction optical depths when the latter can be directly derived from the measured apparent two-way transmittance through the cloud. An evaluation of the CALIOP multiple scattering factor is inferred from these comparisons after assessing and correcting biases in IIR and CALIOP optical depths reported in version 3 data products. In particular, the blackbody radiance taken in the IIR version 3 algorithm is evaluated, and IIR retrievals are corrected accordingly. Numerical simulations and IIR retrievals of ice crystal sizes suggest that the ratios of CALIOP extinction and IIR absorption optical depths should remain roughly constant with respect to temperature. Instead, these ratios are found to increase quasi-linearly by about 40 % as the temperature at the layer centroid altitude decreases from 240 to 200 K. It is discussed that this behavior can be explained by variations of the multiple scattering factor ηT applied to correct the measured apparent two-way transmittance for contribution of forward-scattering. While the CALIOP version 3 retrievals hold ηT fixed at 0.6, this study shows that ηT varies with temperature (and hence cloud particle size) from ηT = 0.8 at 200 K to ηT = 0.5 at 240 K for single-layered semi-transparent cirrus clouds with optical depth larger than 0.3. The revised parameterization of ηT introduces a concomitant temperature dependence in the simultaneously derived CALIOP lidar ratios that is consistent with observed changes in CALIOP

  13. Folded-back solution structure of monomeric factor H of human complement by synchrotron X-ray and neutron scattering, analytical ultracentrifugation and constrained molecular modelling.

    PubMed

    Aslam, M; Perkins, S J

    2001-06-22

    Factor H (FH) is a regulatory cofactor for the protease factor I in the breakdown of C3b in the complement system of immune defence, and binds to heparin and other polyanionic substrates. FH is composed of 20 short consensus/complement repeat (SCR) domains, for which the overall arrangement in solution is unknown. As previous studies had shown that FH can form monomeric or dimeric structures, X-ray and neutron scattering was accordingly performed with FH in the concentration range between 0.7 and 14 mg ml(-1). The radius of gyration of FH was determined to be 11.1-11.3 nm by both methods, and the radii of gyration of the cross-section were 4.4 nm and 1.7 nm. The distance distribution function P(r) showed that the overall length of FH was 38 nm. The neutron data showed that FH was monomeric with a molecular mass of 165,000(+/-17,000) Da. Analytical ultracentrifugation data confirmed this, where sedimentation equilibrium curve fits gave a mean molecular mass of 155,000(+/-3,000) Da. Sedimentation velocity experiments using the g*(s) derivative method showed that FH was monodisperse and had a sedimentation coefficient of 5.3(+/-0.1) S. In order to construct a full model of FH for scattering curve and sedimentation coefficient fits, homology models were constructed for 17 of the 20 SCR domains using knowledge of the NMR structures for FH SCR-5, SCR-15 and SCR-16, and vaccinia coat protein SCR-3 and SCR-4. Molecular dynamics simulations were used to generate a large conformational library for each of the 19 SCR-SCR linker peptides. Peptides from these libraries were combined with the 20 SCR structures in order to generate stereochemically complete models for the FH structure. Using an automated constrained fit procedure, the analysis of 16,752 possible FH models showed that only those models in which the 20 SCR domains were bent back upon themselves were able to account for the scattering and sedimentation data. The best-fit models showed that FH had an overall length

  14. NUTRITIONAL, MICROBIOLOGICAL, AND THERAPEUTIC FACTORS RELATED TO MUCOSITIS IN HEAD AND NECK CANCER PATIENTS: A COHORT STUDY.

    PubMed

    Vidal-Casariego, Alfonso; Fernández-Natal, Isabel; Calleja-Fernández, Alicia; Parras-Padilla, Trinidad; Cano-Rodríguez, Isidoro; Prieto-Alonso, Begoña; Ballesteros-Pomar, María D

    2015-09-01

    Objetivo: el objetivo fue demostrar si la modalidad de tratamiento, el estado nutricional y la flora orofaríngea contribuyen al desarrollo de mucositis en pacientes con cáncer de cabeza y cuello tratados con radioterapia. Métodos: estudio de cohorte de pacientes con cáncer de cabeza y cuello (CyC) tratados con radioterapia. El estado nutricional se evaluó utilizando VGS, IMC e IMM. Se realizó un frotis bucal antes de la radioterapia para el cultivo de bacterias y levaduras. Se evaluó la mucositis usando los criterios de la OMS. Se calcularon el riesgo relativo (RR) y su IC del 95%. Resultados: el estudio incluyó a 35 pacientes, 74,3% hombres, 63,8 (9,9) años de edad, y 34,3% desnutridos. Los tumores estaban localizados en laringe (40,0%), boca (25,7%) y faringe (11,4%). El tratamiento consistió en 66,0 Gy de radiación, quimioterapia (60,0%) y cirugía (57,1%). Se encontraron bacterias en 28,6%, incluyendo Staphylococcus aureus (8,6%) y Escherichia coli (8,6%). Se encontró Candida spp. en el 35,3%. La mucositis fue más frecuente en los pacientes con radioterapia radical [100% vs. 65%, p = 0,01; RR = 1,54 (IC95% 1,12 a 2,12)]. Ni VGS, IMC ni IMM se relacionaron con el desarrollo o la gravedad de la mucositis. Los cultivos positivos para bacterias antes de la radioterapia se relacionaron con mucositis severa [44,4% vs. 12%, p = 0,039; RR = 4,17 (IC95% 1,22 a 14,24)], pero no hubo ninguna relación con la presencia de levaduras. La cirugía no se asoció con la aparición de las cepas estudiadas de bacterias. Conclusión: la colonización bacteriana de la orofaringe antes de la radioterapia puede ser un factor para la mucositis graves en pacientes con cáncer CyC.

  15. Head lice.

    PubMed

    Burgess, Ian F

    2011-05-16

    Head lice can only be diagnosed by finding live lice, as eggs take 7 days to hatch and may appear viable for weeks after death of the egg. Infestation may be more likely in school children, with risks increased in children with more siblings, longer hair, and of lower socioeconomic group. We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments for head lice? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We found 26 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. In this systematic review, we present information relating to the effectiveness and safety of the following interventions: benzyl alcohol, dimeticone, herbal and essential oils, insecticide combinations, isopropyl myristate, ivermectin, lindane, malathion, mechanical removal by combing ("bug busting"), oral trimethoprim-sulfamethoxazole (co-trimoxazole, TMP-SMX), permethrin, phenothrin, pyrethrum, and spinosad.

  16. Head lice

    PubMed Central

    2011-01-01

    Introduction Head lice can only be diagnosed by finding live lice, as eggs take 7 days to hatch and may appear viable for weeks after death of the egg. Infestation may be more likely in school children, with risks increased in children with more siblings, longer hair, and of lower socioeconomic group. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments for head lice? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 26 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review, we present information relating to the effectiveness and safety of the following interventions: benzyl alcohol, dimeticone, herbal and essential oils, insecticide combinations, isopropyl myristate, ivermectin, lindane, malathion, mechanical removal by combing ("bug busting"), oral trimethoprim–sulfamethoxazole (co-trimoxazole, TMP-SMX), permethrin, phenothrin, pyrethrum, and spinosad. PMID:21575285

  17. Scattering amplitudes and static atomic correction factors for the composition-sensitive 002 reflection in sphalerite ternary III-V and II-VI semiconductors.

    PubMed

    Schowalter, M; Müller, K; Rosenauer, A

    2012-01-01

    Modified atomic scattering amplitudes (MASAs), taking into account the redistribution of charge due to bonds, and the respective correction factors considering the effect of static atomic displacements were computed for the chemically sensitive 002 reflection for ternary III-V and II-VI semiconductors. MASAs were derived from computations within the density functional theory formalism. Binary eight-atom unit cells were strained according to each strain state s (thin, intermediate, thick and fully relaxed electron microscopic specimen) and each concentration (x = 0, …, 1 in 0.01 steps), where the lattice parameters for composition x in strain state s were calculated using continuum elasticity theory. The concentration dependence was derived by computing MASAs for each of these binary cells. Correction factors for static atomic displacements were computed from relaxed atom positions by generating 50 × 50 × 50 supercells using the lattice parameter of the eight-atom unit cells. Atoms were randomly distributed according to the required composition. Polynomials were fitted to the composition dependence of the MASAs and the correction factors for the different strain states. Fit parameters are given in the paper.

  18. Dasatinib blocks cetuximab- and radiation-induced nuclear translocation of the epidermal growth factor receptor in head and neck squamous cell carcinoma

    PubMed Central

    Li, Chunrong; Iida, Mari; Dunn, Emily F.; Wheeler, Deric L.

    2010-01-01

    Background and Purpose The aberrant expression of epidermal growth factor receptor (EGFR) has been linked to the etiology of head and neck squamous cell carcinoma (HNSCC). The first major phase III trial combining cetuximab with radiation confirmed a strong survival advantage. However, both cetuximab and radiation can promote EGFR translocation to the nucleus where it enhances resistance to both of these modalities. In this report we sought to determine how to block cetuximab and radiation–induced translocation of EGFR to the nucleus in HNSCC cell lines. Material and Methods We utilized three established HNSCC cell lines, SCC1, SCC6 and SCC1483 and measured nuclear translocation of EGFR after treatment with cetuximab or radiation. We then utilized dasatinib (BMS-354825), a potent, orally bioavailable inhibitor of several tyrosine kinases, including the Src Family Kinases, to determine if SFKs blockade could abrogate cetuximab and radiation-induced nuclear EGFR translocation. Results Cetuximab and radiation treatment of all three HNSCC lines lead to translocation of the EGFR to the nucleus. Blockade of SFKs abrogated cetuximab and radiation-induced EGFR translocation to the nucleus. Conclusions The data presented in this report suggests that both cetuximab and radiation can promote EGFR translocation to the nucleus and dasatinib can inhibit this process. Collectively these findings may suggest that dasatinib can limit EGFR translocation to the nucleus and may enhance radiotherapy plus cetuximab in HNSCC. PMID:20667610

  19. DHQZ-17, a potent inhibitor of the transcription factor HNF4A, suppresses tumorigenicity of head and neck squamous cell carcinoma in vivo.

    PubMed

    Tentu, Shilpa; Nandarapu, Kumarswamyreddy; Muthuraj, Prakash; Venkitasamy, Kesavan; Venkatraman, Ganesh; Rayala, Suresh K

    2017-08-07

    A series of 2, 3-dihydroquinazolinone derivatives were synthesized, characterized and their anticancer activity was determined. Among the compounds synthesized and screened, one compound (17) showed potent anticancer activity against human head and neck squamous cell carcinoma cell line, SCC131 and was non-toxic to normal cells. The compound inhibited the growth of SCC131 cells, with an IC50 of 1.75 μM, triggered apoptotic mode of cell death and caused tumor regression of SCC131 tumor xenografts in athymic mice. To decipher the target for the lead compound, a high throughput qPCR array was performed. Results showed that the compound 17, inhibited the expression of a vital transcription factor HNF4A, involved in regulation of metabolic pathways. Thus, the present work has identified a lead compound 17, with potent anticancer activity, minimal normal cell toxicity and a plausible target and hence definitely holds future prospects as an anticancer agent. © 2017 Wiley Periodicals, Inc.

  20. HRAS Mutations and Resistance to the Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Erlotinib in Head and Neck Squamous Cell Carcinoma Cells

    PubMed Central

    Hah, J. Hun; Zhao, Mei; Pickering, Curtis R.; Frederick, Mitchell J.; Andrews, Genevieve A.; Jasser, Samar A.; Fooshee, David R.; Milas, Zvonimir L.; Galer, Chad; Sano, Daisuke; William, William N.; Kim, Edward; Heymach, John; Byers, Lauren A.; Papadimitrakopoulou, Vali; Myers, Jeffrey N.

    2014-01-01

    Background This was to identify mechanisms of innate resistance to an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, erlotinib, in a panel of head and neck squamous cell carcinoma (HNSCC) cell lines. Specifically, we analyzed the role of HRAS mutations in erlotinib resistance. Methods Erlotinib sensitivity was determined by MTT assays. Molecular signaling pathways and somatic mutations were examined. Changes in sensitivity after modulation of HRAS expression were evaluated. Results All seven cell lines were wild-type for EGFR and KRAS regardless of erlotinib sensitivity; however, one erlotinib-resistant cell line (HN31) harbored an HRAS G12D mutation. Down regulation of HRAS expression by siRNA or shRNA in HN31 led to increased erlotinib sensitivity in vitro and in vivo. Transfection of activating HRAS-mutant (G12D and G12V) constructs into erlotinib-sensitive cell lines made them more resistant to erlotinib. Conclusion Activating HRAS mutations can confer erlotinib resistance in an HRAS mutant HNSCC cell line. PMID:24123531

  1. SU-E-T-72: Commissioning of a Standardized SRS Cone Set: Determination of the Bolus Gap Factors in a Passively Scattered Proton Beam

    SciTech Connect

    Simpson, R; Gordon, I; Ghebremedhin, A; Wroe, A; Schulte, R; Bush, D; Slater, J; Patyal, B

    2014-06-01

    Purpose: To determine the proton output factors for an SRS cone set using standardized apertures and varied range compensators (bolus blanks); specifically, to determine the best method for modeling the bolus gap factor (BGF) and eliminate the need for patient specific calibrations. Methods: A Standard Imaging A-16 chamber was placed in a Plastic Water phantom to measure the change in dose/MU with different treatment combinations for a proton SRS cone, using standardized apertures and range compensators. Measurements were made with all apertures in the SRS cone set, with four different range compensator thicknesses and five different air gaps between the end of the SRS cone and the surface of the phantom. The chamber was located at iso-center and maintained at a constant depth at the center of modulation for all measurements. Each aperture was placed in the cone to measure the change in MU needed to maintain constant dose at the chamber, as the air gap was increased with different thicknesses of bolus. Results: The dose/MU varied significantly with decreasing aperture size, increasing bolus thickness, or increasing air gap. The measured data was fitted with the lowest order polynomials that accurately described the data, to create a model for determining the change in output for any potential combination of devices used to treat a patient. For a given standardized aperture, the BGF could be described by its constituent factors: the bolus thickness factor (BTF) and the nozzle extension factor (NEF). Conclusion: The methods used to model the dose at the calibration point could be used to accurately predict the change in output for SRS proton beams due to the BGF, eliminating the need for patient specific calibrations. This method for modeling SRS treatments could also be applied to model other treatments using passively scattered proton beams.

  2. Influence of G308A polymorphism of tumor necrosis factor-alpha gene on inflammatory markers in postsurgical head and neck cancer patients with early enteral nutrition.

    PubMed

    de Luis, Daniel Antonio; Sagrado, Manue Gonzalez; Vallejo, Luis Angel; Carcedo, Luis María Gil; Izaola, Olatz; Cuellar, Luis; Terroba, María Concepción; Aller, Rocío

    2007-01-01

    Although immune dysfunction in patients with cancer could be multifactorial, the immune system may be modulated by nutritional substrates and genetic background. Our study evaluated the effect of G308A polymorphism of the tumor necrosis factor-alpha (TNF-alpha) gene on inflammatory markers in patients after surgery for head and neck cancer who received early enteral nutrition. A population of 60 patients with oral and laryngeal cancer was enrolled. At surgery patients were treated with a hyperproteic enteral diet. Perioperatively and on postoperative day 6 the following parameters were evaluated: serum values of prealbumin, transferrin, total number of lymphocytes, interleukin-6, TNF-alpha, and C-reactive protein. In addition, genotyping of G308A gene polymorphism was assessed. Patients' mean age was 61.1 +/- 14.6 y (four women, 56 men) with a body mass index of 25.4 +/- 5.2 kg/m(2) and a previous weight loss of 0.35 +/- 0.2 kg. Forty patients (37 men, 3 women; 66.6%) had the genotype G308/G308 (wild group) and 20 patients (19 men, 1 woman; 23.4%) had the genotype G308/A308 (mutant group). A significant increase in prealbumin and transferrin levels was detected in both groups. C-reactive protein decreased in both groups (wild group: 105.1 +/- 60 versus 53.8 +/- 62.3 mg/dL, P < 0.05; mutant group: 99.5 +/- 46 versus 43.9 +/- 51.9 mg/dL, P < 0.05). Interleukin-6 decreased in both groups (wild group: 20.1 +/- 22 versus 6.2 +/- 4.1 pg/mL, P < 0.05; mutant group: 22.3 +/- 38 versus 9.2 +/- 7.4 pg/mL, P = NS). Lymphocytes increased in both groups (wild group: 1102 +/- 468 versus 1600 +/- 537 10(3)/mL, P = NS; mutant group: 1441 +/- 739 10(3)/mL versus 1669 +/- 614 10(6)/mL, P = NS). TNF-alpha showed no changes. The G308A polymorphism of the TNF-alpha gene did not affect levels of inflammatory markers in patients after surgery for head and neck cancer who were treated with early enteral nutrition.

  3. a Global Test of Factorization for Nucleon-Nucleon γp and γγ Scattering

    NASA Astrophysics Data System (ADS)

    Block, Martin M.; Kang, Kyungsik

    The purpose of this paper is to show that the cross-section factorization relation σnn(s)/σγp(s) = σγp(s)/σγγ(s) is satisfied experimentally in the energy domain 8<=√ s<= 2000 GeV, where the σ's are total cross-sections and nn denotes the even portion of the pp and bar pp total cross-section. A convenient phenomenological parametrization for a global simultaneous fit to the pp, bar pp, γp and γγ total cross-section data together with the ρ-value data for pp and bar pp is provided by using real analytic amplitudes. Within experimental errors, we show that factorization is satisfied when we unfold the published γγ data which had averaged the cross-sections obtained by using the two different PHOJET and PYTHIA Monte Carlo results. Our analysis clearly favors the PHOJET results and suggests that the additive quark model, together with vector meson dominance, allows one to compute σγp(s) and σγγ(s) from σnn(s) with essentially no free parameters. The universal ρ-value predicted by our fit, i.e. ρnn = ργp = ργγ, is compared to the ρ-value obtained by a QCD-inspired analysis of bar pp and pp data, including the p-air cross-sections from cosmic rays. The ρ-values obtained from the two techniques are essentially indistinguishable in the energy region 8<=√ s<= 2000 GeV, giving us increased confidence in our parametrization of the cross-sections needed for the factorization relation.

  4. Cutaneous head and neck melanoma in OPTiM, a randomized phase 3 trial of talimogene laherparepvec versus granulocyte‐macrophage colony‐stimulating factor for the treatment of unresected stage IIIB/IIIC/IV melanoma

    PubMed Central

    Agarwala, Sanjiv S.; Ollila, David W.; Hallmeyer, Sigrun; Milhem, Mohammed; Amatruda, Thomas; Nemunaitis, John J.; Harrington, Kevin J.; Chen, Lisa; Shilkrut, Mark; Ross, Merrick; Kaufman, Howard L.

    2016-01-01

    Abstract Background Cutaneous head and neck melanoma has poor outcomes and limited treatment options. In OPTiM, a phase 3 study in patients with unresectable stage IIIB/IIIC/IV melanoma, intralesional administration of the oncolytic virus talimogene laherparepvec improved durable response rate (DRR; continuous response ≥6 months) compared with subcutaneous granulocyte‐macrophage colony‐stimulating factor (GM‐CSF). Methods Retrospective review of OPTiM identified patients with cutaneous head and neck melanoma given talimogene laherparepvec (n = 61) or GM‐CSF (n = 26). Outcomes were compared between talimogene laherparepvec and GM‐CSF treated patients with cutaneous head and neck melanoma. Results DRR was higher for talimogene laherparepvec–treated patients than for GM‐CSF treated patients (36.1% vs 3.8%; p = .001). A total of 29.5% of patients had a complete response with talimogene laherparepvec versus 0% with GM‐CSF. Among talimogene laherparepvec–treated patients with a response, the probability of still being in response after 12 months was 73%. Median overall survival (OS) was 25.2 months for GM‐CSF and had not been reached with talimogene laherparepvec. Conclusion Treatment with talimogene laherparepvec was associated with improved response and survival compared with GM‐CSF in patients with cutaneous head and neck melanoma. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1752–1758, 2016 PMID:27407058

  5. Risk factors of avascular necrosis of the femoral head and fixation failure in patients with valgus angulated femoral neck fractures over the age of 50 years.

    PubMed

    Song, Hyung Keun; Choi, Ho June; Yang, Kyu Hyun

    2016-12-01

    The aim of our study was to identify the risk factors for avascular necrosis of the femoral head (AVN) and fixation failure (FF) after screw osteosynthesis in patients with valgus angulated femoral neck fractures. We conducted a retrospective study of 308 patients (mean age, 72.5 years, range, 50-97 years), with a mean follow-up of 21.4 months (range, 12-64 months). The risk for failure in treatment (FIT) associated with patient- and fracture-related factors was evaluated by logistic regression analyses. FIT was identified in 32 cases (10.3%): 22 cases (7.1%) of AVN and 10 cases (3.2%) of FF. Initial valgus tilt>15° (p=0.023), posterior tilt>15° (p=0.012), and screw sliding distance (p=0.037) were significantly associated with FIT. FIT occurred in 7 patients (5.2%) with B1.2.1 fractures and 17 patients (48.6%) with B1.1.2 fractures (p<0.001). The odds of FIT were 17-fold higher in patients with initial valgus and posterior tilts>15° (B1.1.2) compared to patients with <15° of tilt in both planes (B1.2.1). The severity of initial deformity predicts AVN and FF in patients with valgus angulated femoral neck fractures. Patients with an initial valgus and posterior tilt>15° are reasonable candidates for primary arthroplasty due to high risk of FIT. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Risk factors for second primary neoplasia of esophagus in newly diagnosed head and neck cancer patients: a case–control study

    PubMed Central

    2013-01-01

    Background The prevalence of esophageal neoplasia in head and neck (H&N) cancer patients is not low; however, routine esophageal surveillance is not included in staging of newly-diagnosed H&N cancers. We aimed to investigate the risk factors for synchronous esophageal neoplasia and the impact of endoscopy on management of H&N cancer patients. Methods A total of 129 newly diagnosed H&N cancer patients who underwent endoscopy with white-light imaging, narrow-band imaging (NBI) with magnifying endoscopy (ME), and chromoendoscopy with 1.5% Lugol’s solution, before definite treatment were enrolled prospectively. Results 60 esophageal lesions were biopsied from 53 (41.1%) patients, including 11 low-grade, 14 high-grade intraepithelial neoplasia and 12 invasive carcinoma in 30 (23.3%) patients. Alcohol consumption [odds ratio (OR) 5.90, 95% confidence interval (CI) 1.23-26.44], advanced stage (stage III and IV) of index H&N cancers (OR 2.98, 95% CI 1.11-7.99), and lower body mass index (BMI) (every 1-kg/m2 increment with OR 0.87, 95% CI 0.76-0.99) were independent risk factors for synchronous esophageal neoplasia. NBI with ME was the ideal screening tool (sensitivity, specificity, and accuracy of 97.3%, 94.1%, and 96.3%, respectively, for detection of dysplastic and cancerous esophageal lesions). The treatment strategy was modified after endoscopy in 20 (15.5%) patients. The number needed to screen was 6.45 (95% CI 4.60-10.90). Conclusions NBI-ME surveillance of esophagus should be done in newly-diagnosed H&N cancer patients, especially those with alcohol drinking, lower BMI, and advanced stage of primary tumor. PMID:24456340

  7. Basic helix-loop-helix transcription factor BcbHLHpol functions as a positive regulator of pollen development in non-heading Chinese cabbage.

    PubMed

    Liu, Tongkun; Li, Ying; Zhang, Changwei; Duan, Weike; Huang, Feiyi; Hou, Xilin

    2014-12-01

    Cytoplasmic male sterility (CMS) is a common trait in higher plants, and several transcription factors regulate pollen development. Previously, we obtained a basic helix-loop-helix transcription factor, BcbHLHpol, via suppression subtractive hybridization in non-heading Chinese cabbage. However, the regulatory function of BcbHLHpol during anther and pollen development remains unclear. In this study, BcbHLHpol was cloned, and its tissue-specific expression profile was analyzed. The results of real-time polymerase chain reaction showed that BcbHLHpol was highly expressed in maintainer buds and that the transcripts of BcbHLHpol significantly decreased in the buds of pol CMS. A virus-induced gene silencing vector that targets BcbHLHpol was constructed and transformed into Brassica campestris plants to further explore the function of BcbHLHpol. Male sterility and short stature were observed in BcbHLHpol-silenced plants. The degradation of tapetal cells was inhibited in BcbHLHpol-silenced plants, and nutrients were insufficiently supplied to the microspore. These phenomena resulted in pollen abortion. This result indicates that BcbHLHpol functions as a positive regulator in pollen development. Yeast two-hybrid and bimolecular fluorescence complementation assays revealed that BcbHLHpol interacted with BcSKP1 in the nucleus. This finding suggests that BcbHLHpol and BcSKP1 are positive coordinating regulators of pollen development. Quantitative real-time PCR indicated that BcbHLHpol and BcSKP1 can be induced at low temperatures. Thus, we propose that BcbHLHpol is necessary for meiosis. This study provides insights into the regulatory functions of the BcbHLHpol network during anther development.

  8. Head trauma after instrumental births.

    PubMed

    Doumouchtsis, Stergios K; Arulkumaran, Sabaratnam

    2008-03-01

    Instrumental vaginal delivery involves the use of the vacuum extractor or obstetric forceps to facilitate delivery of the fetus. It is associated with substantial risk of head injury, including hemorrhage, fractures, and, rarely, brain damage or fetal death. This review article describes the different types, etiology, pathophysiology, risk factors, and clinical features of head trauma after instrumental birth, along with their management and prevention strategies.

  9. Monte Carlo study of the effects of system geometry and antiscatter grids on cone-beam CT scatter distributions

    PubMed Central

    Sisniega, A.; Zbijewski, W.; Badal, A.; Kyprianou, I. S.; Stayman, J. W.; Vaquero, J. J.; Siewerdsen, J. H.

    2013-01-01

    Purpose: The proliferation of cone-beam CT (CBCT) has created interest in performance optimization, with x-ray scatter identified among the main limitations to image quality. CBCT often contends with elevated scatter, but the wide variety of imaging geometry in different CBCT configurations suggests that not all configurations are affected to the same extent. Graphics processing unit (GPU) accelerated Monte Carlo (MC) simulations are employed over a range of imaging geometries to elucidate the factors governing scatter characteristics, efficacy of antiscatter grids, guide system design, and augment development of scatter correction. Methods: A MC x-ray simulator implemented on GPU was accelerated by inclusion of variance reduction techniques (interaction splitting, forced scattering, and forced detection) and extended to include x-ray spectra and analytical models of antiscatter grids and flat-panel detectors. The simulator was applied to small animal (SA), musculoskeletal (MSK) extremity, otolaryngology (Head), breast, interventional C-arm, and on-board (kilovoltage) linear accelerator (Linac) imaging, with an axis-to-detector distance (ADD) of 5, 12, 22, 32, 60, and 50 cm, respectively. Each configuration was modeled with and without an antiscatter grid and with (i) an elliptical cylinder varying 70–280 mm in major axis; and (ii) digital murine and anthropomorphic models. The effects of scatter were evaluated in terms of the angular distribution of scatter incident upon the detector, scatter-to-primary ratio (SPR), artifact magnitude, contrast, contrast-to-noise ratio (CNR), and visual assessment. Results: Variance reduction yielded improvements in MC simulation efficiency ranging from ∼17-fold (for SA CBCT) to ∼35-fold (for Head and C-arm), with the most significant acceleration due to interaction splitting (∼6 to ∼10-fold increase in efficiency). The benefit of a more extended geometry was evident by virtue of a larger air gap—e.g., for a 16 cm

  10. Monte Carlo study of the effects of system geometry and antiscatter grids on cone-beam CT scatter distributions.

    PubMed

    Sisniega, A; Zbijewski, W; Badal, A; Kyprianou, I S; Stayman, J W; Vaquero, J J; Siewerdsen, J H

    2013-05-01

    The proliferation of cone-beam CT (CBCT) has created interest in performance optimization, with x-ray scatter identified among the main limitations to image quality. CBCT often contends with elevated scatter, but the wide variety of imaging geometry in different CBCT configurations suggests that not all configurations are affected to the same extent. Graphics processing unit (GPU) accelerated Monte Carlo (MC) simulations are employed over a range of imaging geometries to elucidate the factors governing scatter characteristics, efficacy of antiscatter grids, guide system design, and augment development of scatter correction. A MC x-ray simulator implemented on GPU was accelerated by inclusion of variance reduction techniques (interaction splitting, forced scattering, and forced detection) and extended to include x-ray spectra and analytical models of antiscatter grids and flat-panel detectors. The simulator was applied to small animal (SA), musculoskeletal (MSK) extremity, otolaryngology (Head), breast, interventional C-arm, and on-board (kilovoltage) linear accelerator (Linac) imaging, with an axis-to-detector distance (ADD) of 5, 12, 22, 32, 60, and 50 cm, respectively. Each configuration was modeled with and without an antiscatter grid and with (i) an elliptical cylinder varying 70-280 mm in major axis; and (ii) digital murine and anthropomorphic models. The