WorldWideScience

Sample records for monochrome dbs halftoning

  1. Steganography in clustered-dot halftones using orientation modulation and modification of direct binary search

    Science.gov (United States)

    Chen, Yung-Yao; Hong, Sheng-Yi; Chen, Kai-Wen

    2015-03-01

    This paper proposes a novel message-embedded halftoning scheme that is based on orientation modulation (OM) encoding. To achieve high image quality, we employ a human visual system (HVS)-based error metric between the continuous-tone image and a data-embedded halftone, and integrate a modified direct binary search (DBS) framework into the proposed message-embedded halftoning method. The modified DBS framework ensures that the resulting data-embedded halftones have optimal image quality from the viewpoint of the HVS.

  2. Oriented modulation for watermarking in direct binary search halftone images.

    Science.gov (United States)

    Guo, Jing-Ming; Su, Chang-Cheng; Liu, Yun-Fu; Lee, Hua; Lee, Jiann-Der

    2012-09-01

    In this paper, a halftoning-based watermarking method is presented. This method enables high pixel-depth watermark embedding, while maintaining high image quality. This technique is capable of embedding watermarks with pixel depths up to 3 bits without causing prominent degradation to the image quality. To achieve high image quality, the parallel oriented high-efficient direct binary search (DBS) halftoning is selected to be integrated with the proposed orientation modulation (OM) method. The OM method utilizes different halftone texture orientations to carry different watermark data. In the decoder, the least-mean-square-trained filters are applied for feature extraction from watermarked images in the frequency domain, and the naïve Bayes classifier is used to analyze the extracted features and ultimately to decode the watermark data. Experimental results show that the DBS-based OM encoding method maintains a high degree of image quality and realizes the processing efficiency and robustness to be adapted in printing applications.

  3. Microscopic Halftone Image Segmentation

    Institute of Scientific and Technical Information of China (English)

    WANG Yong-gang; YANG Jie; DING Yong-sheng

    2004-01-01

    Microscopic halftone image recognition and analysis can provide quantitative evidence for printing quality control and fault diagnosis of printing devices, while halftone image segmentation is one of the significant steps during the procedure. Automatic segmentation on microscopic dots by the aid of the Fuzzy C-Means (FCM) method that takes account of the fuzziness of halftone image and utilizes its color information adequately is realized. Then some examples show the technique effective and simple with better performance of noise immunity than some usual methods. In addition, the segmentation results obtained by the FCM in different color spaces are compared, which indicates that the method using the FCM in the f1f2f3 color space is superior to the rest.

  4. Halftone visual cryptography.

    Science.gov (United States)

    Zhou, Zhi; Arce, Gonzalo R; Di Crescenzo, Giovanni

    2006-08-01

    Visual cryptography encodes a secret binary image (SI) into n shares of random binary patterns. If the shares are xeroxed onto transparencies, the secret image can be visually decoded by superimposing a qualified subset of transparencies, but no secret information can be obtained from the superposition of a forbidden subset. The binary patterns of the n shares, however, have no visual meaning and hinder the objectives of visual cryptography. Extended visual cryptography [1] was proposed recently to construct meaningful binary images as shares using hypergraph colourings, but the visual quality is poor. In this paper, a novel technique named halftone visual cryptography is proposed to achieve visual cryptography via halftoning. Based on the blue-noise dithering principles, the proposed method utilizes the void and cluster algorithm [2] to encode a secret binary image into n halftone shares (images) carrying significant visual information. The simulation shows that the visual quality of the obtained halftone shares are observably better than that attained by any available visual cryptography method known to date.

  5. Mirror monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Mankos, Marian [Electron Optica, Inc., Palo Alto, CA (United States); Shadman, Khashayar [Electron Optica, Inc., Palo Alto, CA (United States)

    2014-12-02

    In this SBIR project, Electron Optica, Inc. (EOI) is developing a mirror electron monochromator (MirrorChrom) attachment to new and retrofitted electron microscopes (EMs) for improving the energy resolution of the EM from the characteristic range of 0.2-0.5 eV to the range of 10-50 meV. This improvement will enhance the characterization of materials by imaging and spectroscopy. In particular, the monochromator will refine the energy spectra characterizing materials, as obtained from transmission EMs [TEMs] fitted with electron spectrometers, and it will increase the spatial resolution of the images of materials taken with scanning EMs (SEMs) operated at low voltages. EOI’s MirrorChrom technology utilizes a magnetic prism to simultaneously deflect the electron beam off the axis of the microscope column by 90° and disperse the electrons in proportional to their energies into a module with an electron mirror and a knife-edge. The knife-edge cuts off the tails of the energy distribution to reduce the energy spread of the electrons that are reflected, and subsequently deflected, back into the microscope column. The knife-edge is less prone to contamination, and thereby charging, than the conventional slits used in existing monochromators, which improves the reliability and stability of the module. The overall design of the MirrorChrom exploits the symmetry inherent in reversing the electron trajectory in order to maintain the beam brightness – a parameter that impacts how well the electron beam can be focused downstream onto a sample. During phase I, EOI drafted a set of candidate monochromator architectures and evaluated the trade-offs between energy resolution and beam current to achieve the optimum design for three particular applications with market potential: increasing the spatial resolution of low voltage SEMs, increasing the energy resolution of low voltage TEMs (beam energy of 5-20 keV), and increasing the energy resolution of conventional TEMs (beam

  6. Halftone Coding with JBIG2

    DEFF Research Database (Denmark)

    Martins, Bo; Forchhammer, Søren

    2000-01-01

    of a halftone pattern dictionary.The decoder first decodes the gray-scale image. Then for each gray-scale pixel looks up the corresponding halftonepattern in the dictionary and places it in the reconstruction bitmap at the position corresponding to the gray-scale pixel. The coding method is inherently lossy......The emerging international standard for compression of bilevel images and bi-level documents, JBIG2,provides a mode dedicated for lossy coding of halftones. The encoding procedure involves descreening of the bi-levelimage into gray-scale, encoding of the gray-scale image, and construction...... and care must be taken to avoid introducing artifacts in the reconstructed image. We describe how to apply this coding method for halftones created by periodic ordered dithering, by clustered dot screening (offset printing), and by techniques which in effect dithers with blue noise, e.g., error diffusion...

  7. Halftone Coding with JBIG2

    DEFF Research Database (Denmark)

    Martins, Bo; Forchhammer, Søren

    2000-01-01

    The emerging international standard for compression of bilevel images and bi-level documents, JBIG2,provides a mode dedicated for lossy coding of halftones. The encoding procedure involves descreening of the bi-levelimage into gray-scale, encoding of the gray-scale image, and construction...... and care must be taken to avoid introducing artifacts in the reconstructed image. We describe how to apply this coding method for halftones created by periodic ordered dithering, by clustered dot screening (offset printing), and by techniques which in effect dithers with blue noise, e.g., error diffusion....... Besides descreening and construction of the dictionary, we address graceful degradationand artifact removal....

  8. Thermodynamics-inspired inverse halftoning via multiple halftone images

    Institute of Scientific and Technical Information of China (English)

    SAIKA Yohei; AOKI Toshizumi

    2012-01-01

    Based on an analogy between thermodynamics and Bayesian inference,inverse halftoning was formulated using multiple halftone images based on Bayesian inference using the maximizer of the posterior marginal (MPM) estimate.Applying Monte Carlo simulation to a set of snapshots of the Q-Ising model,it was demonstrated that optimal performance is achieved around the Bayes-optimal condition within statistical uncertainty and that the performance of the Bayes-optimal solution is superior to that of the maximum-aposteriori (MAP) estimation which is a deterministic limit of the MPM estimate.These properties were qualitatively confirmed by the mean-field theory using an infinite-range model established in statistical mechanics.Additionally,a practical and useful method was constructed using the statistical mechanical iterative method via the Bethe approximation.Numerical simulations for a 256-grayscale standard image show that Bethe approximation works as good as the MPM estimation if the parameters are set appropriately.

  9. Polyomino-Based Digital Halftoning

    CERN Document Server

    Vanderhaeghe, David

    2008-01-01

    In this work, we present a new method for generating a threshold structure. This kind of structure can be advantageously used in various halftoning algorithms such as clustered-dot or dispersed-dot dithering, error diffusion with threshold modulation, etc. The proposed method is based on rectifiable polyominoes -- a non-periodic hierarchical structure, which tiles the Euclidean plane with no gaps. Each polyomino contains a fixed number of discrete threshold values. Thanks to its inherent non-periodic nature combined with off-line optimization of threshold values, our polyomino-based threshold structure shows blue-noise spectral properties. The halftone images produced with this threshold structure have high visual quality. Although the proposed method is general, and can be applied on any polyomino tiling, we consider one particular case: tiling with G-hexominoes. We compare our polyomino-based threshold structure with the best known state-of-the-art methods for generation threshold matrices, and conclude con...

  10. DBS for Obesity

    Science.gov (United States)

    Franco, Ruth; Fonoff, Erich T.; Alvarenga, Pedro; Lopes, Antonio Carlos; Miguel, Euripides C.; Teixeira, Manoel J.; Damiani, Durval; Hamani, Clement

    2016-01-01

    Obesity is a chronic, progressive and prevalent disorder. Morbid obesity, in particular, is associated with numerous comorbidities and early mortality. In patients with morbid obesity, pharmacological and behavioral approaches often have limited results. Bariatric surgery is quite effective but is associated with operative failures and a non-negligible incidence of side effects. In the last decades, deep brain stimulation (DBS) has been investigated as a neurosurgical modality to treat various neuropsychiatric disorders. In this article we review the rationale for selecting different brain targets, surgical results and future perspectives for the use of DBS in medically refractory obesity. PMID:27438859

  11. DBS for Obesity

    Directory of Open Access Journals (Sweden)

    Ruth Franco

    2016-07-01

    Full Text Available Obesity is a chronic, progressive and prevalent disorder. Morbid obesity, in particular, is associated with numerous comorbidities and early mortality. In patients with morbid obesity, pharmacological and behavioral approaches often have limited results. Bariatric surgery is quite effective but is associated with operative failures and a non-negligible incidence of side effects. In the last decades, deep brain stimulation (DBS has been investigated as a neurosurgical modality to treat various neuropsychiatric disorders. In this article we review the rationale for selecting different brain targets, surgical results and future perspectives for the use of DBS in medically refractory obesity.

  12. Data compression of scanned halftone images

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Jensen, Kim S.

    1994-01-01

    A new method for coding scanned halftone images is proposed. It is information-lossy, but still preserving the image quality, compression rates of 16-35 have been achieved for a typical test image scanned on a high resolution scanner. The bi-level halftone images are filtered, in phase...... with the halftone grid, and converted to a gray level representation. A new digital description of (halftone) grids has been developed for this purpose. The gray level values are coded according to a scheme based on states derived from a segmentation of gray values. To enable real-time processing of high resolution...... scanner output, the coding has been parallelized and implemented on a transputer system. For comparison, the test image was coded using existing (lossless) methods giving compression rates of 2-7. The best of these, a combination of predictive and binary arithmetic coding was modified and optimized...

  13. Demystifying the Halftoning Process: Conventional, Stochastic, and Hybrid Halftone Dot Structures

    Science.gov (United States)

    Oliver, Garth R.; Waite, Jerry J.

    2006-01-01

    For more than 150 years, printers have been faithfully reproducing continuous tone originals using halftoning techniques. For about 120 years, printers could only use the AM halftoning technique invented by Henry Talbot. In recent years, the advent of powerful raster image processors and high-resolution output devices has increased the variety of…

  14. Recent trends in digital halftoning

    Science.gov (United States)

    Delabastita, Paul A.

    1997-02-01

    Screening is perhaps the oldest form of image processing. The word refers to the mechanical cross line screens that were used at the beginning of this century for the purpose of photomechanical reproduction. Later on, these mechanical screens were replaced by photographic contact screens that enabled significantly improved process control. In the early eighties, the optical screening on graphic arts scanners was replaced by a combination of laser optics and electronic screening. The algorithms, however, were still digital implementations of the original optical methods. The printing needs in the fast growing computer and software industry gave birth to a number of alternative printing technologies such as electrophotographic and inkjet printing. Originally these deices were only designed for printing text, but soon people started experimenting and using them for printing images. The relatively low spatial resolutions of these new devices however made complete review of 'the screening issue' necessary to achieve an acceptable image quality. In this paper a number of recent developments in screening technology are summarized. Special attention is given to the interaction that exists between a halftone screen and the printing devices on which they are rendered including the color mixing behavior. Improved screening techniques are presented that take advantage of modeling the physical behavior of the rendering device.

  15. HIRDLS monochromator calibration equipment

    Science.gov (United States)

    Hepplewhite, Christopher L.; Barnett, John J.; Djotni, Karim; Whitney, John G.; Bracken, Justain N.; Wolfenden, Roger; Row, Frederick; Palmer, Christopher W. P.; Watkins, Robert E. J.; Knight, Rodney J.; Gray, Peter F.; Hammond, Geoffory

    2003-11-01

    A specially designed and built monochromator was developed for the spectral calibration of the HIRDLS instrument. The High Resolution Dynamics Limb Sounder (HIRDLS) is a precision infra-red remote sensing instrument with very tight requirements on the knowledge of the response to received radiation. A high performance, vacuum compatible monochromator, was developed with a wavelength range from 4 to 20 microns to encompass that of the HIRDLS instrument. The monochromator is integrated into a collimating system which is shared with a set of tiny broad band sources used for independent spatial response measurements (reported elsewhere). This paper describes the design and implementation of the monochromator and the performance obtained during the period of calibration of the HIRDLS instrument at Oxford University in 2002.

  16. HALFTONING: REVISIÓN Y ANÁLISIS HALFTONING: REVIEW AND ANALYSIS

    Directory of Open Access Journals (Sweden)

    Fernando Pelcastre

    2012-12-01

    Full Text Available Halftoning es una técnica indispensable para mostrar imágenes digitales en pantalla e imprimirlas en papel usando cualquier tipo de impresora tales como Inkjet y láser. Además de lo anterior, la técnica de halftoning se ha empleado recientemente en diversas aplicaciones en el campo de computación y comunicación, tales como compresión y autenticación de imágenes, criptografía visual, etc. Este artículo proporciona una revisión detallada de los métodos principales de halftoning, los cuales son ordered dither, difusión de error, difusión de error con enfatización de borde, difusión de puntos, ruido verde y búsqueda binaria directa. Para el análisis de las ventajas y desventajas de cada método de halftoning se realizó una comparación de calidad de imagen halftone generada por los métodos mencionados anteriormente usando medición MOS (Mean Opinion Score. Asimismo, se consideró la complejidad computacional de cada método de halftoning.Halftoning is an indispensable technique used for showing digital images on screen and printing them on paper using any kind of printer such as Inkjet and Laser. Additionally, halftoning technique has been employed recently in several applications in the computation and communication fields, such as compression and authentication of images, visual cryptography, etc. This article provides as detailed review of the main halftoning methods, such as ordered dither, error diffusion, error diffusion with edge emphasis, dot diffusion, green noise, and direct binary search. For analyzing advantages and disadvantages of each halfoning method, a quality comparison of the halftone image generated by the already named methods was performed using Mean Opinion Score (MOS measurement. Likewise, computational complexity of each halftoning method was taken into consideration.

  17. Neural net classification and LMS reconstruction to halftone images

    Science.gov (United States)

    Chang, Pao-Chi; Yu, Che-Sheng

    1998-01-01

    The objective of this work is to reconstruct high quality gray-level images from halftone images, or the inverse halftoning process. We develop high performance halftone reconstruction methods for several commonly used halftone techniques. For better reconstruction quality, image classification based on halftone techniques is placed before the reconstruction process so that the halftone reconstruction process can be fine tuned for each halftone technique. The classification is based on enhanced 1D correlation of halftone images and processed with a three- layer back propagation neural network. This classification method reached 100 percent accuracy with a limited set of images processed by dispersed-dot ordered dithering, clustered-dot ordered dithering, constrained average, and error diffusion methods in our experiments. For image reconstruction, we apply the least-mean-square adaptive filtering algorithm which intends to discover the optimal filter weights and the mask shapes. As a result, it yields very good reconstruction image quality. The error diffusion yields the best reconstructed quality among the halftone methods. In addition, the LMS method generates optimal image masks which are significantly different for each halftone method. These optimal masks can also be applied to more sophisticated reconstruction methods as the default filter masks.

  18. Evaluation of Graininess for Digital Halftone Images

    Institute of Scientific and Technical Information of China (English)

    Shigeru Kitakubo

    2004-01-01

    Some results of image recognition tests are given, in which a testee looks at an image and tell if he/she can recognize a certain figure in it or not. When studying digital halftoning process, it is important to discuss the resolution of the human eye, or eye and brain, from the viewpoint of image recognition.

  19. Parallel halftoning technique using dot diffusion optimization

    Science.gov (United States)

    Molina-Garcia, Javier; Ponomaryov, Volodymyr I.; Reyes-Reyes, Rogelio; Cruz-Ramos, Clara

    2017-05-01

    In this paper, a novel approach for halftone images is proposed and implemented for images that are obtained by the Dot Diffusion (DD) method. Designed technique is based on an optimization of the so-called class matrix used in DD algorithm and it consists of generation new versions of class matrix, which has no baron and near-baron in order to minimize inconsistencies during the distribution of the error. Proposed class matrix has different properties and each is designed for two different applications: applications where the inverse-halftoning is necessary, and applications where this method is not required. The proposed method has been implemented in GPU (NVIDIA GeForce GTX 750 Ti), multicore processors (AMD FX(tm)-6300 Six-Core Processor and in Intel core i5-4200U), using CUDA and OpenCV over a PC with linux. Experimental results have shown that novel framework generates a good quality of the halftone images and the inverse halftone images obtained. The simulation results using parallel architectures have demonstrated the efficiency of the novel technique when it is implemented in real-time processing.

  20. Reflectance and transmittance model for recto-verso halftone prints

    OpenAIRE

    Hebert, M.; R. D. Hersch

    2006-01-01

    We propose a spectral prediction model for predicting the reflectance and transmittance of recto-verso halftone prints. A recto-verso halftone print is modeled as a diffusing substrate surrounded by two inked interfaces in contact with air (or with another medium). The interaction of light with the print comprises three components: (a) the attenuation of the incident light penetrating the print across the inked interface, (b) the internal reflectance and internal transmittance that accounts f...

  1. Impact of Electrostatic Assist on Halftone Mottle in Shrink Films

    Directory of Open Access Journals (Sweden)

    Akshay V. Joshi

    2015-09-01

    Full Text Available Gravure printing delivers intricate print quality and exhibit better feasibility for printing long run packaging jobs. PVC and PETG are widely used shrink films printed by gravure process. The variation in ink transfer from gravure cells on to the substrate results in print mottle. The variation is inevitable and requires close monitoring with tight control on process parameters to deliver good dot fidelity. The electrostatic assist in gravure improves the ink transfer efficiency but is greatly influenced by ESA parameters such as air gap (distance between charge bar and impression roller and voltage. Moreover, it is imperative to study the combined effect of ESA and gravure process parameters such as line screen, viscosity and speed for the minimization of half-tone mottle in shrink films. A general full factorial design was performed for the above mentioned parameters to evaluate half-tone mottle. The significant levels of both the main and interactions were studied by ANOVA approach. The statistical analysis revealed the significance of all the process parameters with viscosity, line screen and voltage being the major contributors in minimization of half-tone mottle. The optimized setting showed reduction in halftone mottle by 33% and 32% for PVC and PET-G respectively. The developed regression model was tested that showed more than 95% predictability. Furthermore, the uniformity of dot was measured by image to non-image area (ratio distribution. The result showed reduction in halftone mottle with uniform dot distribution.

  2. Disrupting neuronal transmission: Mechanism of DBS?

    Directory of Open Access Journals (Sweden)

    Satomi eChiken

    2014-03-01

    Full Text Available Applying high-frequency stimulation to deep brain rain structure, known as deep brain stimulation (DBS, has now been recognized an effective therapeutic option for a wide range of neurological and psychiatric disorders. DBS targeting the basal ganglia thalamo-cortical loop, especially the internal segment of the globus pallidus, subthalamic nucleus and thalamus, has been widely employed as a successful surgical therapy for movement disorders, such as Parkinson’s disease, dystonia and tremor. However, the neurophysiological mechanism underling the action of DBS remains unclear and is still under debate: does DBS inhibit or excite local neuronal elements? In this review, we will examine this question and propose the alternative interpretation: DBS dissociates inputs and outputs, resulting in disruption of abnormal signal transmission.

  3. Practical aspects of monochromators developed for transmission electron microscopy

    Science.gov (United States)

    Kimoto, Koji

    2014-01-01

    A few practical aspects of monochromators recently developed for transmission electron microscopy are briefly reviewed. The basic structures and properties of four monochromators, a single Wien filter monochromator, a double Wien filter monochromator, an omega-shaped electrostatic monochromator and an alpha-shaped magnetic monochromator, are outlined. The advantages and side effects of these monochromators in spectroscopy and imaging are pointed out. A few properties of the monochromators in imaging, such as spatial or angular chromaticity, are also discussed. PMID:25125333

  4. APS high heat load monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Lee, W.K.; Mills, D.

    1993-02-01

    This document contains the design specifications of the APS high heat load (HHL) monochromator and associated accessories as of February 1993. It should be noted that work is continuing on many parts of the monochromator including the mechanical design, crystal cooling designs, etc. Where appropriate, we have tried to add supporting documentation, references to published papers, and calculations from which we based our decisions. The underlying philosophy behind performance specifications of this monochromator was to fabricate a device that would be useful to as many APS users as possible, that is, the design should be as generic as possible. In other words, we believe that this design will be capable of operating on both bending magnet and ID beamlines (with the appropriate changes to the cooling and crystals) with both flat and inclined crystal geometries and with a variety of coolants. It was strongly felt that this monochromator should have good energy scanning capabilities over the classical energy range of about 4 to 20 keywith Si (111) crystals. For this reason, a design incorporating one rotation stage to drive both the first and second crystals was considered most promising. Separate rotary stages for the first and second crystals can sometimes provide more flexibility in their capacities to carry heavy loads (for heavily cooled first crystals or sagittal benders of second crystals), but their tuning capabilities were considered inferior to the single axis approach.

  5. Yule-Nielsen based multi-angle reflectance prediction of metallic halftones

    Science.gov (United States)

    Babaei, Vahid; Hersch, Roger D.

    2015-01-01

    Spectral prediction models are widely used for characterizing classical, almost transparent ink halftones printed on a diffuse substrate. Metallic-ink prints however reflect a significant portion of light in the specular direction. Due to their opaque nature, multi-color metallic halftones require juxtaposed halftoning methods where halftone dots of different colors are laid out side-by-side. In this work, we study the application of the Yule-Nielsen spectral Neugebauer (YNSN) model on metallic halftones in order to predict their reflectances. The model is calibrated separately at each considered illumination and observation angle. For each measuring geometry, there is a different Yule-Nielsen n-value. For traditional prints on paper, the n-value expresses the amount of optical dot gain. In the case of the metallic prints, the optical dot gain is much smaller than in paper prints. With the fitted n-values, we try to better understand the interaction of light and metallic halftones.

  6. Evaluation of digital halftones image by vector error diffusion

    Science.gov (United States)

    Kouzaki, Masahiro; Itoh, Tetsuya; Kawaguchi, Takayuki; Tsumura, Norimichi; Haneishi, Hideaki; Miyake, Yoichi

    1998-12-01

    The vector error diffusion (VED) method is applied to proudce the digital halftone images by an electrophotographic printer with 600 dpi. Objective image quality of those obtained images is evaluated and analyzed. As a result, in the color reproduction of halftone image by the VED method, it was clear that there are large color difference between target color and printed color typically in the mid-tone colors. We consider it is due to the printer properties including dot-gain. It was also clear that the color noise of the VED method is larger compared with that of the conventional scalar error diffusion method in some patches. It was remarkable that ununiform patterns are generated by the VED method.

  7. IMPACT OF ERROR FILTERS ON SHARES IN HALFTONE VISUAL CRYPTOGRAPHY

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    Sunil Agrawal

    2012-05-01

    Full Text Available Visual cryptography encodes a secret binary image (SI into shares of random binary patterns. If the shares are xeroxed onto transparencies, the secret image can be visually decoded by superimposing a qualified subset of transparencies, but no secret information can be obtained from the superposition of a forbidden subset. The binary patterns of the shares, however, have no visual meaning and hinder the objectives of visual cryptography. Halftone visual cryptography encodes a secret binary image into n halftone shares (images carrying significant visual information. When secrecy is important factor rather than the quality of recovered image the shares must be of better visual quality. Different filters such as Floyd-Steinberg, Jarvis, Stuki, Burkes, Sierra, and Stevenson’s-Arce are used and their impact on visual quality of shares is seen. The simulation shows that error filters used in error diffusion lays a great impact on the visual quality of the shares.

  8. IMPACT OF ERROR FILTERS ON SHARES IN HALFTONE VISUAL CRYPTOGRAPHY

    OpenAIRE

    Sunil Agrawal; Anshul Sharma

    2012-01-01

    Visual cryptography encodes a secret binary image (SI) into shares of random binary patterns. If the shares are xeroxed onto transparencies, the secret image can be visually decoded by superimposing a qualified subset of transparencies, but no secret information can be obtained from the superposition of a forbidden subset. The binary patterns of the shares, however, have no visual meaning and hinder the objectives of visual cryptography. Halftone visual cryptography encodes a s...

  9. Statistical Modelling of Print half-tone mottle in PET-G and PVC Shrink Films

    Directory of Open Access Journals (Sweden)

    Akshay V Joshi

    2016-11-01

    Full Text Available PVC and PET-G (Glycol modified polyethylene terephthalate have the highest consumption in the shrink sleeve market due to its high shrink abilities and cost effectiveness. The reproductions of fine tone details on these films are challenging as the occurrence of graininess and image-noise results in print defect such as print half-tone mottle. The presence of print half-tone mottle is visually disturbing leading to wastage of ink, substrate and time. The purpose of this study is to investigate the effect of gravure process parameters viz. ink viscosity, press speed, impression hardness and line screen and develop statistical model for print half-tone mottle in shrink films. The base line for print half-tone mottle was determined by conducting production runs on press with a defined set of process parameters and the target was set to minimize it from the baseline. The half-tone area was scanned and processed through SFDA algorithm to calculate print half-tone mottle. The design of experiments (DOE was generated for above-mentioned process parameters and was analysed by analysis of variance (ANOVA to find the significant factor affecting the print half-tone mottle. The analysis revealed line screen, viscosity and hardness as significant factors in minimizing print half-tone mottle. The results showed minimization of print half-tone mottle by 28% for both PVC and PET-G films. Furthermore, regression model was developed and validated for print half-tone mottle and a correlation coefficient (R2 of 0.8696 and 0.879 was achieved for PET-G and PVC respectively. The proposed model is helpful in determining the impact of gravure process parameters and prediction of print half-tone mottle in shrink films.

  10. Ink-constrained halftoning with application to QR codes

    Science.gov (United States)

    Bayeh, Marzieh; Compaan, Erin; Lindsey, Theodore; Orlow, Nathan; Melczer, Stephen; Voller, Zachary

    2014-01-01

    This paper examines adding visually significant, human recognizable data into QR codes without affecting their machine readability by utilizing known methods in image processing. Each module of a given QR code is broken down into pixels, which are halftoned in such a way as to keep the QR code structure while revealing aspects of the secondary image to the human eye. The loss of information associated to this procedure is discussed, and entropy values are calculated for examples given in the paper. Numerous examples of QR codes with embedded images are included.

  11. Multimedia Data Hiding and Authentication via Halftoning and Coordinate Projection

    Directory of Open Access Journals (Sweden)

    Wu Chai Wah

    2002-01-01

    Full Text Available We present image data hiding and authentication schemes based on halftoning and coordinate projection. The proposed data hiding scheme can embed images of the same size and similar bit depth into the cover image and robustness against compression is demonstrated. The image authentication scheme is based on the data hiding scheme and can detect, localize, and repair the tampered area of the image. Furthermore, the self-repairing feature of the authentication scheme has a hologram-like quality; any portion of the image can be used to reconstruct the entire image, with a greater quality of reconstruction as the portion size increases.

  12. The RAI DBS experiment with Olympus

    Science.gov (United States)

    Castelli, Enzo

    The Italian broadcasting network (RAI) has studied the development of a national DBS service in an effort to outline a proposal for a space segment configuration compatible with development of new services, including HDTV. Proposals so far considered feature the integration of RAI's channel on Olympus in a future operational system and after extensive experimental use. Contents of the experimental program are discussed, and need for a broadcasting standard which considers projected introduction of HDTV is noted. The debate between RAI and consumer electronic industries on the use of broadcasting standards is outlined. The position of RAI in the context of HDTV and DBS is defined and the issue of determining the most effective transmission standard during the experimental stage is raised. It is pointed out that, in the absence of new production facilities for HDTV, the maximum quality which MAC will yield will be that of PAL since programs must be produced in PAL and then converted into MAC. Two alternatives for strategy on the use of broadcasting standards for DBS are offered. Finally, technical experiments and a market survey are discussed.

  13. Novel approaches to the design of halftone masks for analog lithography.

    Science.gov (United States)

    Teschke, Marcel; Sinzinger, Stefan

    2008-09-10

    We report novel approaches to the design of halftone masks for analog lithography. The approaches are derived from interferometric phase contrast. In a first step we show that the interferometric phase-contrast method with detour holograms can be reduced into a single binary mask. In a second step we introduce the interferometric phase-contrast method by interference of the object wavefront with the conjugate object wavefront. This method also allows for a design of a halftone mask. To use kinoform holograms as halftone phase masks, we show in a third step the combination of the zeroth-order phase-contrast technique with the interferometric phase-contrast method.

  14. Classification of Error-Diffused Halftone Images Based on Spectral Regression Kernel Discriminant Analysis

    Directory of Open Access Journals (Sweden)

    Zhigao Zeng

    2016-01-01

    Full Text Available This paper proposes a novel algorithm to solve the challenging problem of classifying error-diffused halftone images. We firstly design the class feature matrices, after extracting the image patches according to their statistics characteristics, to classify the error-diffused halftone images. Then, the spectral regression kernel discriminant analysis is used for feature dimension reduction. The error-diffused halftone images are finally classified using an idea similar to the nearest centroids classifier. As demonstrated by the experimental results, our method is fast and can achieve a high classification accuracy rate with an added benefit of robustness in tackling noise.

  15. Progressive halftone watermarking using multilayer table lookup strategy.

    Science.gov (United States)

    Guo, Jing-Ming; Lai, Guo-Hung; Wong, Koksheik; Chang, Li-Chung

    2015-07-01

    In this paper, a halftoning-based multilayer watermarking of low computational complexity is proposed. An additional data-hiding technique is also employed to embed multiple watermarks into the watermark to be embedded to improve the security and embedding capacity. At the encoder, the efficient direct binary search method is employed to generate 256 reference tables to ensure the output is in halftone format. Subsequently, watermarks are embedded by a set of optimized compressed tables with various textural angles for table lookup. At the decoder, the least mean square metric is considered to increase the differences among those generated phenotypes of the embedding angles and reduce the required number of dimensions for each angle. Finally, the naïve Bayes classifier is employed to collect the possibilities of multilayer information for classifying the associated angles to extract the embedded watermarks. These decoded watermarks can be further overlapped for retrieving the additional hidden-layer watermarks. Experimental results show that the proposed method requires only 8.4 ms for embedding a watermark into an image of size 512×512 , under the 32-bit Windows 7 platform running on 4GB RAM, Intel core i7 Sandy Bridge with 4GB RAM and IDE Visual Studio 2010. Finally, only 2 MB is required to store the proposed compressed reference table.

  16. Application of Modified Digital Halftoning Techniques to Data Hiding in Personalized Stamps

    Institute of Scientific and Technical Information of China (English)

    Hsi-Chun Wang; Chi-Ming Lian; Pei-Chi Hsiao

    2004-01-01

    The objective of this research is to embed information in personalized stamps by modified digital halftoning techniques. The displaced and deformed halftone dots are used to encode data in the personalized stamps. Hidden information can be retrieved by either an optical decoder or digital image processing techniques.The results show that personalized stamps with value-added features like data hiding or digital watermarking can be successfully implemented.

  17. A young scientists' perspective on DBS: A plea for an international DBS organization

    NARCIS (Netherlands)

    Sommers, R.P.; Dings, R.P.J.M.; Neijenhuijs, K.I.; Andringa, H.; Arts, S.; Bult, D. van de; Klockenbusch, L.; Wanningen, E.; Bruin, L.C. de; Haselager, W.F.G.

    2015-01-01

    Our think tank tasked by the Dutch Health Council, consisting of Radboud University Nijmegen Honours Academy students with various backgrounds, investigated the implications of Deep Brain Stimulation (DBS) for psychiatric patients. During this investigation, a number of methodological, ethical and s

  18. Metal nanoparticles in DBS card materials modification

    Science.gov (United States)

    Metelkin, A.; Frolov, G.; Kuznetsov, D.; Kolesnikov, E.; Chuprunov, K.; Kondakov, S.; Osipov, A.; Samsonova, J.

    2015-11-01

    In the recent years the method of collecting and storing Dried Blood Spots (DBS) on special cellulose membrane (paper) has gained wide popularity. But possible damage of biosamples caused by microorganisms in case of their incomplete drying is a disadvantage of the method. It can be overcome by treating sample-collection membranes with colloidal solutions of metal nanoparticles, having antibacterial effect. The team studied antibacterial properties of nonwoven material samples with various coatings (alcohol sols of copper, aluminium, iron, titanium, silver and vanadium nanoparticles). Colloidal solutions of nanoparticles were obtained by means of electroerosion method with further low-temperature plasma condensation. Antibacterial activity of fiberglass and cellulose membrane samples with nanoparticle coatings was studied using B. cereus and plaque bacteria cultures. It was revealed that nanostructured coatings can suppress bacterial activity; in addition they can diffuse from the membrane surface into medium which leads to widening the areas of inhibiting testing cultures’ growth. Thus, membrane materials treatment with alcohol-sols of metal nanoparticles can be seen as promising for conferring antibacterial properties to DBS carriers.

  19. Large monochromator systems at PETRA III

    Energy Technology Data Exchange (ETDEWEB)

    Horbach, J., E-mail: Jan.Horbach@desy.de [Deutsches Elektronen-Synchrotron Hamburg, Notkestrasse 85, 22607 Hamburg (Germany); Degenhardt, M.; Hahn, U.; Heuer, J.; Peters, H.B.; Schulte-Schrepping, H. [Deutsches Elektronen-Synchrotron Hamburg, Notkestrasse 85, 22607 Hamburg (Germany); Donat, A.; Luedecke, H. [Deutsches Elektronen-Synchrotron Zeuthen, Platanenallee 6, 15738 Zeuthen (Germany)

    2011-09-01

    For the beamlines of the new synchrotron radiation source PETRA III, fixed exit double crystal monochromators with specific features were developed. To achieve a compact arrangement of the canted undulator beamlines at Sectors 2 and 6, it is necessary to shift one of the two beamlines in vertical direction. This is done by Large Offset Monochromators (LOM). One of these monochromators (LOM500, installed at beamline P03) is cooled with liquid nitrogen as it accepts the white beam. LOM1250 (installed at beamline P08) accepts a monochromatic beam and therefore needs no cooling system. The challenge with this monochromator is its large beam offset by 1.25 m. The energy range in combination with this large vertical beam offset demands for a relative crystal movement of roughly 3 m along the beam direction. This is solved by translating each crystal by up to 1.5 m. LOM1250 is equipped with a laser-based stabilisation, which allows compensating the thermal drift of the mechanical components involved in the positioning of the crystals. This is done by piezo actors below the crystals using the laser beam position after passing each crystal as feedback. With this approach we provide a closed loop system without attenuation of the X-ray beam by position monitors. The third monochromator at beamline P06 shifts the beam only by 21 mm upwards but has a linear travel of one crystal by 3.9 m. This is due to its large energy range of 4.4-90 keV using multilayer crystals. The technical design and mechanical engineering issues of the three Large Monochromator Systems at beamlines P03, P06 and P08 are highlighted in this article.

  20. Check the special moves Halftone a central sun sunspot different angles using local correlation tracking

    Directory of Open Access Journals (Sweden)

    Monireh Askarikhah

    2016-03-01

    Full Text Available Sunspots, solar magnetic field effect on a large scale are outstanding. In this research field study of surface movement (special move in a Lightening Solar Shade Halftone sphere central angle of the sun in three different here. The evolution of current research and special horizontal movement in a sunspot on the basis of time-series observations imaging data in the blue spectral range with a wavelength continuum Central line spots active area of 4504 angstroms During the 3 day 10933NOAA dated 7 January (9.0 hours (UT 12:35 until (UT 12: 56, 8 January (8.0 hours (UT 06: 00 to (UT 06 21, Jan 9 (6/0 of the time (UT 05: 00 to (UT 05: 21, 2007 were obtained by using LCT (local correlation tracking has studied. Halftone stains in the three-averaged (averaged over 10 consecutive images and averaged over 20 consecutive images flow rate for each of the three categories Map angles (total 9 speed stream map obtained, as well as a lot of speed graph speed on the map, each of which is for an angle we examined. What is clear in some parts of the maps quickly climb (eruption in plasma and in some places fall (collapse plasma-level Halftone be observed. The maps quickly, the (current intensity Halftone patterns toward the inner penumbra shadow and movement patterns foreign to the outside strongly suggest Halftone That resulted in the dismissal of this shift is the dividing line that location is reached. Due to the frequency graph maps quickly we realized all three angles to this topic Slick passing moves quickly, especially given that the three angles of the half shadow has fallen. As well as speed of movement of the intensity of the Halftone patterns of the dividing line within the shadows of the reductions in external Halftone dividing line toward the photosphere increases.

  1. Monochromator design for the HADAS reflectometer in Jülich

    Science.gov (United States)

    Rücker, U.; Alefeld, B.; Kentzinger, E.; Brückel, Th

    2000-06-01

    A reflectometer with polarization analysis is being built on the basis of the HADAS spectrometer in the neutron guide hall at the research reactor FRJ-2 (DIDO) in Jülich. For obtaining the optimal flux at the sample position, the performances of several monochromator designs have been calculated, e.g. focusing mirrors, mosaic monochromator crystals and bent perfect crystal monochromators. Under the given geometrical limitations a double monochromator with bent perfect Si crystals and vertical focusing has the best performance.

  2. Effective temperature and exergy of monochromic blackbody radiation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new parameter named monochromic effective temperature Tλ is proposed, which represents the thermodynamic quality of monochromic blackbody radiation. The exergy of the monochromic blackbody radiation is expressed by Tλ. The monochromic effective temperature equation is developed, which shows that the produci of Tλ and the wavelength is constant, which equals 5.33016×10-3 tion in photosynthesis can be explained by the results of this work.

  3. Halftone biasing OPC technology: an approach for achieving fine bias control on raster-scan systems

    Science.gov (United States)

    Nakagawa, Kent H.; Chen, J. Fung; Socha, Robert J.; Laidig, Thomas L.; Wampler, Kurt E.; Van Den Broeke, Douglas J.; Dusa, Mircea V.; Caldwell, Roger F.

    1999-08-01

    As the semiconductor roadmap continues to require imaging of smaller features on wafers, we continue to explore new approaches in OPC strategies to enhance existing technology. Advanced reticle design, intended for printing sub-wavelength features, requires the support of very fine-increment biases on semi-densely-pitched lines, where the CD correction requires only a fraction of the spot size of an e-beam system. Halftone biasing, a new OPC strategy, has been proposed to support these biases on a raster-scan e-beam system without the need for a reduced address unit and the consequent write time penalty. The manufacturability and inspectability of halftone-biased lines are explored, using an OPC characterization reticle. Pattern fidelity is examined using both optical and SEM tools. Printed DUV resist line edge profiles are compared for both halftone and non-halftone feature edges. Halftone biasing was applied to an SRAM-type simulation reticle, to examine its impact on data volume, write time reduction, and printing performance.

  4. Angular vibrations of cryogenically cooled double-crystal monochromators.

    Science.gov (United States)

    Sergueev, I; Döhrmann, R; Horbach, J; Heuer, J

    2016-09-01

    The effect of angular vibrations of the crystals in cryogenically cooled monochromators on the beam performance has been studied theoretically and experimentally. A simple relation between amplitude of the vibrations and size of the focused beam is developed. It is shown that the double-crystal monochromator vibrations affect not only the image size but also the image position along the optical axis. Several methods to measure vibrations with the X-ray beam are explained and analyzed. The methods have been applied to systematically study angular crystal vibrations at monochromators installed at the PETRA III light source. Characteristic values of the amplitudes of angular vibrations for different monochromators are presented.

  5. New method for spectrofluorometer monochromator wavelength calibration.

    Science.gov (United States)

    Paladini, A A; Erijman, L

    1988-09-01

    A method is presented for wavelength calibration of spectrofluorometer monochromators. It is based on the distortion that the characteristic absorption bands of glass filters (holmium or didymium oxide), commonly used for calibration of spectrophotometers, introduce in the emitted fluorescence of fluorophores like indole, diphenyl hexatriene, xylene or rhodamine 6G. Those filters or a well characterized absorber with sharp bands like benzene vapor can be used for the same purpose. The wavelength calibration accuracy obtained with this method is better than 0.1 nm, and requires no modification in the geometry of the spectrofluorometer sample compartment.

  6. Medical image of the week: DBS polysomnogram artifact

    Directory of Open Access Journals (Sweden)

    Shetty S,

    2015-10-01

    Full Text Available A 79-year-old man with known Parkinson’s disease and status post deep brain stimulator (DBS implantation underwent an overnight polysomnogram for clinical suspicion of obstructive sleep apnea. Artifact was seen on the polysomnogram recording (Figures 1 & 2. Patient-related electrical artifacts may be seen from devices such as pacemakers, deep brain stimulators and vagal nerve simulators. Abrupt discontinuation of DBS is associated with a high likelihood of worsening of symptoms in patients with Parkinson’s disease (1. Patients with DBS are most commonly programmed in monopolar mode. Bipolar configuration, forms a short electrical dipole that affects a relatively smaller volume of tissue and generates far less artifact, suggesting that this may be an effective option in a Parkinsonian patient with indications for polysomnography (2.

  7. Fatal hemorrhage from AVM after DBS surgery: case report.

    Science.gov (United States)

    Fukaya, Chikashi; Shimoda, Kentaro; Watanabe, Mitsuru; Morishita, Takashi; Sumi, Koichiro; Otaka, Toshiharu; Obuchi, Toshiki; Toshikazu, Kano; Kobayashi, Kazutaka; Oshima, Hideki; Yamamoto, Takamitsu; Katayama, Yoichi

    2013-01-01

    Intracranial hemorrhage is a crucial complication of deep brain stimulation (DBS) surgery. The bleeding caused by mechanical tissue injury due to microelectrode and/or DBS electrode lead insertion has been well studied. However, hemorrhage caused by a congenital underlying disease such as vascular malformation has not been examined carefully. We encountered a case of intracerebral hemorrhage from arteriovenous malformation (AVM) after DBS surgery. Preoperative magnetic resonance (MR) imaging did not show any abnormality in the patient. Computed tomography (CT) images taken immediately after the surgery did not show any intracranial hematoma and other abnormal findings. However, the patient did not recover from the general anesthesia, and hemorrhage in the left occipital lobe was detected by CT performed a day after the surgery. The location of the hematoma was markedly distant from the trajectory of DBS leads. Evacuation of the hematoma under general anesthesia was immediately performed. As an intraoperative finding, we noted the presence of abnormal vessels inside the hematoma in the occipital lobe. Tissue specimens including the abnormal vessels were obtained for histopathological analysis, results of which led to the diagnosis was AVM. Despite its low incidence, we would like to advise that such a type of hemorrhage could occur and measures should be taken to prevent its occurrence as much as possible. Preoperative detection of abnormal vessels by MR angiography and/or CT angiography might be helpful. Moreover, paying close attention to the possible leakage of cerebrospinal fluid during surgery might be important. © 2012 International Neuromodulation Society.

  8. DBS Radio: Deathstar or Dud? Info. Packets No. 24.

    Science.gov (United States)

    Pizzi, Skip

    The Federal Communications Commission (FCC) has been progressing over the past 5 years toward the institution of Direct Broadcast Satellite Radio (DBS-R) which would institute a new type of radio service. The FCC refers to the service as Satellite DARS (Digital Audio Radio Service), and it would provide reliable, high-fidelity satellite-delivered…

  9. Yule-Nielsen based recto-verso color halftone transmittance prediction model.

    Science.gov (United States)

    Hébert, Mathieu; Hersch, Roger D

    2011-02-01

    The transmittance spectrum of halftone prints on paper is predicted thanks to a model inspired by the Yule-Nielsen modified spectral Neugebauer model used for reflectance predictions. This model is well adapted for strongly scattering printing supports and applicable to recto-verso prints. Model parameters are obtained by a few transmittance measurements of calibration patches printed on one side of the paper. The model was verified with recto-verso specimens printed by inkjet with classical and custom inks, at different halftone frequencies and on various types of paper. Predictions are as accurate as those obtained with a previously developed reflectance and transmittance prediction model relying on the multiple reflections of light between the paper and the print-air interfaces. Optimal n values are smaller in transmission mode compared with the reflection model. This indicates a smaller amount of lateral light propagation in the transmission mode.

  10. Edge-Directed Error Diffused Digital Halftoning: A Steerable Filter Approach

    Directory of Open Access Journals (Sweden)

    Pardeep Garg

    2009-09-01

    Full Text Available In this paper the edge-directed error diffused digital halftoning in noisy media is analyzed. It is known that there occurs error in transmitting data through a communication channel due toaddition of noise, generally additive white Gaussian noise (AWGN. The proposed work employs Steerable stochastic error diffusion (SSED approach, a hybrid scheme that utilizes the advantages of Steerable filter for edge detection purpose and five neighbor stochastic error diffusion (FNSED approach for error diffusion purpose. Analysis of different methods of edgedetectionand error diffusion in the presence of zero mean AWGN with different values of variance has also been made. The results show that the proposed scheme produces halftones of better quality in the presence of even large value of noise variance compared to other approaches of edge detection and error diffusion.

  11. Filters involving derivatives with application to reconstruction from scanned halftone images

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Jensen, Kim S.

    1995-01-01

    This paper presents a method for designing finite impulse response (FIR) filters for samples of a 2-D signal, e.g., an image, and its gradient. The filters, which are called blended filters, are decomposable in three filters, each separable in 1-D filters on subsets of the data set. Optimality...... filters are developed and applied to the problem of gray value image reconstruction from bilevel (scanned) clustered-dot halftone images, which is an application useful in the graphic arts. Reconstruction results are given, showing that reconstruction with higher resolution than the halftone grid...... in the minimum mean square error sense (MMSE) of blended filtering is shown for signals with separable autocorrelation function. Relations between correlation functions for signals and their gradients are derived. Blended filters may be composed from FIR Wiener filters using these relations. Simple blended...

  12. Spectral reflectance and transmittance of stacks of nonscattering films printed with halftone colors

    OpenAIRE

    Hébert, Mathieu; Machizaud, Jacques

    2012-01-01

    International audience; This paper combines and extends two optical models based on a two-collimated-flux approach that we previously proposed for the reflectance and transmittance of nonscattering elements, i.e., stacked nonscattering plastic films on the one hand, and films printed in halftone on the other hand. Those two models are revisited and combined by introducing different reflectances and transmittances on the two sides of a printed film, a common situation in practice. We then addr...

  13. Comparison of weight changes following unilateral and staged bilateral STN DBS for advanced PD

    OpenAIRE

    Lee, Eric M; Kurundkar, Ashish; Cutter, Gary R.; Huang, He; Guthrie, Barton L.; Watts, Ray L; Walker, Harrison C.

    2011-01-01

    Unilateral and bilateral subthalamic nucleus deep brain stimulation (STN DBS) in Parkinson's disease (PD) result in weight gain in the initial postoperative months, but little is known about the changes in weight following unilateral and staged bilateral STN DBS over longer time intervals. A case–control comparison evaluated weight changes over 2 years in 43 consecutive unilateral STN DBS patients, among whom 25 elected to undergo staged bilateral STN DBS, and 21 age-matched and disease sever...

  14. A multicarrier TDM transmission system for DBS-A

    Science.gov (United States)

    Campanella, S. J.

    1992-03-01

    Satellite communications service for space based broadcasting has been suggested by the National Research Council's Technical Operation's Committee for the Voice of America. The service is referred to as direct broadcast from space-audio (DBS-A). This paper presents a concept incorporating low bit rate source coding for voice and music, digital modulation, forward error correction coding and Viterbi decoding, multiple satellite beams, and multiple carrier time division multiplexed (TDM) transmission to provide a system capable of world wide coverage. The system provides the capability to narrow cast to specific geographically clustered audiences. Emphasis is on the space segment (transmitter) and earth segment (receiver) using the techniques mentioned above.

  15. Should DBS for Psychiatric Disorders be Considered a Form of Psychosurgery? Ethical and Legal Considerations.

    Science.gov (United States)

    Stahl, Devan; Cabrera, Laura; Gibb, Tyler

    2017-06-26

    Deep brain stimulation (DBS), a surgical procedure involving the implantation of electrodes in the brain, has rekindled the medical community's interest in psychosurgery. Whereas many researchers argue DBS is substantially different from psychosurgery, we argue psychiatric DBS-though a much more precise and refined treatment than its predecessors-is nevertheless a form of psychosurgery, which raises both old and new ethical and legal concerns that have not been given proper attention. Learning from the ethical and regulatory failures of older forms of psychosurgery can help shed light on how to address the regulatory gaps that exist currently in DBS research. To show why it is important to address the current regulatory gaps within psychiatric DBS, we draw on the motivations underlying the regulation of earlier forms of psychosurgery in the US. We begin by providing a brief history of psychosurgery and electrical brain stimulation in the US. Against this backdrop, we introduce psychiatric DBS, exploring current research and ongoing clinical trials. We then draw out the ethical and regulatory similarities between earlier forms of psychosurgery and psychiatric DBS. As we will show, the factors that motivated strict regulation of earlier psychosurgical procedures mirror concerns with psychiatric DBS today. We offer three recommendations for psychiatric DBS regulation, which echo earlier motivations for regulating psychosurgery, along with new considerations that reflect the novel technologies used in DBS.

  16. Monochromator development at 4W1B beamline of BSRF

    Science.gov (United States)

    Xie, Yaning; Yan, Y.; Hu, T. D.; Liu, T.; Xian, D. C.

    2001-07-01

    The 4W1B is a X-ray monochromator beamline for XAFS at BSRF. During the upgrading phase, we have redesigned the monochromator to improve the performance of the beamline. It is a goniometer based, fixed exit double crystal monochromator. A mechanical linkage is employed to adjust the distance between the surfaces of the two crystals as the Bragg angle is changed to keep the outgoing beam direction constant. The whole mechanism is driven by only one stepping motor. The testing result shows that over the scanning range of 5-30°, the shift of outgoing beam position is less then 70 μm in the vertical direction. The basic principle, the mechanical realization, and the error analysis are discussed in detail. The performance and the testing results are also presented in this paper.

  17. Monochromator development at 4W1B beamiline of BSRF

    Institute of Scientific and Technical Information of China (English)

    YaningXie; Y.Yan; T.D.Hu; T.Liu; D.C.Xian

    2001-01-01

    The 4W1B is a X-ary monochromator beamline for XAFS at BSRF.During the upgrading phase,we have redsigned the monochromator to improve the performnce of beamline.It is a goniometer based,fixed exit double crystal monochromator.A mechanical linkage is employed to adjust the distance between the surfaces of the two crystals as the Bragg angle is changed to keep the outgoing beam direction constant.The whole mechanism is driven by only one stepping motor.The testing result shows that over the scanning range of 5-30°,the shift of outgoing beam position is less then 70μm in the vertical direction.The basic principle,the mechanical realization,and the error analysis are discussed in detail.The performance and the testing results are also presented in this paper.2001 Elsevier Science B.V.All rights reserved.

  18. Yule-Nielsen effect in halftone prints: graphical analysis method and improvement of the Yule-Nielsen transform

    Science.gov (United States)

    Hébert, Mathieu

    2014-01-01

    The well-known Yule-Nielsen modified spectral Neugebauer model is one of the most accurate predictive models for the spectral reflectance of printed halftone colors which expresses the spectral reflectance of halftones raised to the power 1/n as a linear combination of the spectral reflectance of the fulltone colors (Neugebauer primaries) also raised to the power 1/n, where n is a tunable real number. The power 1/n transform, characteristic of the Yule-Nielsen transform, empirically models the nonlinear relationship between the spectral reflectances of halftones and fulltones due to the internal propagation of light by scattering into the printing support, a phenomenon known as "optical dot gain" or "Yule- Nielsen effect". In this paper, we propose a graphical method permitting to observe this non-linear relationship in the case of single-ink halftones and to experimentally check the capacity of the Yule-Nielsen model to predict it accurately. In the case where the Yule-Nielsen transform is not well adapted to the considered type of prints, we propose alternative transforms in order to improve the prediction accuracy.

  19. A hard X-ray laboratory for monochromator characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Hamelin, B. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    Since their installation at ILL during the 1970`s the ILL {gamma}-ray diffractometers have been intensively used in the development of neutron monochromators. However, the ageing of the sources and new developments in hard X-ray diffractometry lead to a decision at the end of 1995 to replace the existing {gamma}-ray laboratory with a hard X-ray laboratory, based on a 420 keV generator, making available in the long term several beam-lines for rapid characterisation of monochromator crystals. The facility is now installed and its characteristics and advantages are outlined. (author). 2 refs.

  20. Deutsche Bibliotheksstatistik (DBS: Konzept, Umsetzung und Perspektiven für eine umfassende Datenbasis zum Bibliothekswesen in Deutschland: 10 Fragen von Bruno Bauer an Ronald M. Schmidt, Leiter der DBS / Deutsche Bibliotheksstatistik (DBS: Concept, implementation and prospect for a comprehensive database on library statistics in Germany: 10 questions interview with Ronald M. Schmidt, head of DBS, by Bruno Bauer

    Directory of Open Access Journals (Sweden)

    Schmidt, Ronald M.

    2008-06-01

    Full Text Available The DBS, Deutsche Bibliotheksstatistik (German Library Statistics, http://www.bibliotheksstatistik.de, reports since 1974. Around 9000 libraries file data on facilities, equipment, holdings, usage, budget and staff.Data collection, evaluation, and presentation today are carried out online only. Aim of DBS is the formation of a national data pool containing statistical data on all types of libraries.The interview informs about the concept of DBS and its differentation of public, university and specialised libraries. It covers at length the increasing important topic of data collection of holdings and usage in digital libraries. The DBS process of data evaluation and publication will be described and connections between DBS and the library benchmark index BIX will be explained. Finally international cooperation options for DBS will be discussed.

  1. DBSproc: An open source process for DBS electrode localization and tractographic analysis.

    Science.gov (United States)

    Lauro, Peter M; Vanegas-Arroyave, Nora; Huang, Ling; Taylor, Paul A; Zaghloul, Kareem A; Lungu, Codrin; Saad, Ziad S; Horovitz, Silvina G

    2016-01-01

    Deep brain stimulation (DBS) is an effective surgical treatment for movement disorders. Although stimulation sites for movement disorders such as Parkinson's disease are established, the therapeutic mechanisms of DBS remain controversial. Recent research suggests that specific white-matter tract and circuit activation mediates symptom relief. To investigate these questions, we have developed a patient-specific open-source software pipeline called 'DBSproc' for (1) localizing DBS electrodes and contacts from postoperative CT images, (2) processing structural and diffusion MRI data, (3) registering all images to a common space, (4) estimating DBS activation volume from patient-specific voltage and impedance, and (5) understanding the DBS contact-brain connectivity through probabilistic tractography. In this paper, we explain our methodology and provide validation with anatomical and tractographic data. This method can be used to help investigate mechanisms of action of DBS, inform surgical and clinical assessments, and define new therapeutic targets.

  2. Comparison of weight changes following unilateral and staged bilateral STN DBS for advanced PD.

    Science.gov (United States)

    Lee, Eric M; Kurundkar, Ashish; Cutter, Gary R; Huang, He; Guthrie, Barton L; Watts, Ray L; Walker, Harrison C

    2011-09-01

    Unilateral and bilateral subthalamic nucleus deep brain stimulation (STN DBS) in Parkinson's disease (PD) result in weight gain in the initial postoperative months, but little is known about the changes in weight following unilateral and staged bilateral STN DBS over longer time intervals. A case-control comparison evaluated weight changes over 2 years in 43 consecutive unilateral STN DBS patients, among whom 25 elected to undergo staged bilateral STN DBS, and 21 age-matched and disease severity matched PD controls without DBS. Regression analyses incorporating age, gender, and baseline weight in case or control were conducted to assess weight changes 2 years after the initial unilateral surgery. Unilateral STN DBS and staged bilateral STN DBS patients gained 3.9 ± 2.0 kg and 5.6 ± 2.1 kg versus their preoperative baseline weight (P weight gain in staged bilateral STN DBS patients versus unilateral patients, we found no evidence for an equivalent or synergistic increase in body weight following placement of the second DBS electrode.

  3. Dependence of Dbl and Dbs Transformation on MEK and NF-κB Activation

    OpenAIRE

    Whitehead, Ian P; Lambert, Que T.; Glaven, Judith A.; Abe, Karon; Rossman, Kent L.; Mahon, Gwendolyn M.; Trzaskos, James M.; Kay, Robert; Campbell, Sharon L; Der, Channing J.

    1999-01-01

    Dbs was identified initially as a transforming protein and is a member of the Dbl family of proteins (>20 mammalian members). Here we show that Dbs, like its rat homolog Ost and the closely related Dbl, exhibited guanine nucleotide exchange activity for the Rho family members RhoA and Cdc42, but not Rac1, in vitro. Dbs transforming activity was blocked by specific inhibitors of RhoA and Cdc42 function, demonstrating the importance of these small GTPases in Dbs-mediated growth deregulation. Al...

  4. Composite germanium monochromators - results for the TriCS

    Energy Technology Data Exchange (ETDEWEB)

    Schefer, J.; Fischer, S.; Boehm, M.; Keller, L.; Horisberger, M.; Medarde, M.; Fischer, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Composite germanium monochromators are in the beginning of their application in neutron diffraction. We show here the importance of the permanent quality control with neutrons on the example of the 311 wafers which will be used on the single crystal diffractometer TriCS at SINQ. (author) 2 figs., 3 refs.

  5. Monochromator on a synchrotron undulator source for liquid surface studies

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage; Freund, A.K.

    1992-01-01

    a monochromator made of a beryllium mosaic crystal using the (002) reflection in Laue geometry placed in undulator beams of DORIS III at the Hamburger Synchrotronstrahlungslabor and of the European Synchrotron Radiation Facility. An analysis of the diffraction properties in terms of mosaic spread, heat load...

  6. T2-relaxometry predicts outcome of DBS in idiopathic Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Tarja Lönnfors-Weitzel, MD

    2016-01-01

    Conclusions: The lower boundaries of T2r in the STN predict motor outcome in DBS. T2r asymmetry in the STN is not associated with increased clinical symptoms, but with response to therapy. Thus, patients with very low T2r may be inappropriate candidates for DBS.

  7. Two-flux transfer matrix model for predicting the reflectance and transmittance of duplex halftone prints.

    Science.gov (United States)

    Mazauric, Serge; Hébert, Mathieu; Simonot, Lionel; Fournel, Thierry

    2014-12-01

    We introduce a model allowing convenient calculation of the spectral reflectance and transmittance of duplex prints. It is based on flux transfer matrices and enables retrieving classical Kubelka-Munk formulas, as well as extended formulas for nonsymmetric layers. By making different assumptions on the flux transfers, we obtain two predictive models for the duplex halftone prints: the "duplex Clapper-Yule model," which is an extension of the classical Clapper-Yule model, and the "duplex primary reflectance-transmittance model." The two models can be calibrated from either reflectance or transmittance measurements; only the second model can be calibrated from both measurements, thus giving optimal accuracy for both reflectance and transmittance predictions. The conceptual differences between the two models are deeply analyzed, as well as their advantages and drawbacks in terms of calibration. According to the test carried out in this study with paper printed in inkjet, their predictive performances are good provided appropriate calibration options are selected.

  8. A vacuum ultraviolet filtering monochromator for synchrotron-based spectroscopy

    Science.gov (United States)

    Janik, Ireneusz; Marin, Timothy W.

    2013-01-01

    We describe the design, characterization, and implementation of a vacuum ultraviolet (VUV) monochromator for use in filtering stray and scattered light from the principal monochromator output of the Stainless Steel Seya VUV synchrotron beam line at the Synchrotron Radiation Center, University of Wisconsin-Madison. We demonstrate a reduction of three orders of magnitude of stray and scattered light over the wavelength range 1400-2000 Å with minimal loss of light intensity, allowing for over six orders of magnitude of dynamic range in light detection. We suggest that a similar filtering scheme can be utilized in any variety of spectroscopic applications where a large dynamic range and low amount of background signal are of import, such as in transmittance experiments with very high optical density.

  9. Design and performance of the ALS double-crystal monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Jones, G.; Ryce, S.; Perera, R.C.C. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    A new {open_quotes}Cowan type{close_quotes} double-crystal monochromator, based on the boomerang design used at NSLS beamline X-24A, has been developed for beamline 9.3.1 at the ALS, a windowless UHV beamline covering the 1-6 keV photon-energy range. Beamline 9.3.1 is designed to simultaneously achieve the goals of high energy resolution, high flux, and high brightness at the sample. The mechanical design has been simplified, and recent developments in technology have been included. Measured mechanical precision of the monochromator shows significant improvement over existing designs. In tests with x-rays at NSLS beamline X-23 A2, maximum deviations in the intensity of monochromatic light were just 7% during scans of several hundred eV in the vicinity of the Cr K edge (6 keV) with the monochromator operating without intensity feedback. Such precision is essential because of the high brightness of the ALS radiation and the overall length of beamline 9.3.1 (26 m).

  10. Deep brain stimulation during pregnancy and delivery: experience from a series of DBS babies

    Directory of Open Access Journals (Sweden)

    Emma eSCELZO

    2015-09-01

    Full Text Available Introduction: Deep brain stimulation (DBS is widely used to improve quality of life in movement disorders and psychiatric diseases. Even though the ability to have children has a big impact on patients’ life, only a few studies describe the role of DBS in pregnancy. Objective: To describe risks and management of women treated by DBS for disabling movement disorders (MD or psychiatric diseases during pregnancy and delivery. Methods: We report a retrospective case series of women, followed in two DBS centers, who became pregnant and went on to give birth to a child while suffering from disabling MD or psychiatric diseases (Parkinson’s disease (PD, dystonia, Tourette’s syndrome (TS, Obsessive Compulsive Disorder (OCD treated by DBS. Clinical status, complications and management before, during and after pregnancy are reported. Two illustrative cases are described in greater detail.Results: DBS improved motor and behavioural disorders in all patients and allowed reduction in, or even total interruption of disease-specific medication during pregnancy. With the exception of the spontaneous early abortion of one fetus in a twin pregnancy, all pregnancies were uneventful in terms of obstetric and pediatric management. DBS parameters were adjusted in five patients in order to limit clinical worsening during pregnancy. Implanted material limited breast-feeding in one patient because of local pain at submammal stimulator site and led to local discomfort related to stretching of the cable with increasing belly size in another patient whose stimulator was implanted in the abdominal wall. Conclusions: Not only is it safe for young women with MD, TS and OCD who have a DBS-System implanted to become pregnant and give birth to a baby but DBS seems to be the key to becoming pregnant, having children, and thus greatly improves quality of life.

  11. Quantitative analysis of methyl and propyl parabens in neonatal DBS using LC-MS/MS.

    Science.gov (United States)

    Yakkundi, Shirish; Mulla, Hussain; Pandya, Hitesh; Turner, Mark A; McElnay, James

    2016-06-01

    Excipients are used to overcome the chemical, physical and microbiological challenges posed by developing formulated medicines. Both methyl and propyl paraben are commonly used in pediatric liquid formulations. There is no data on systemic exposure to parabens in neonates. The European Study of Neonatal Exposure to Excipients project has investigated this. Results & methodology: DBS sampling was used to collect opportunistic blood samples. Parabens were extracted from the DBS and analyzed using a validated LC-MS/MS assay. The above assay was applied to analyze neonatal DBS samples. The blood concentrations of parabens in neonates confirm systemic exposure to parabens following administration of routine medicines.

  12. Articulatory Changes in Vowel Production following STN DBS and Levodopa Intake in Parkinson’s Disease

    National Research Council Canada - National Science Library

    Martel Sauvageau, Vincent; Roy, Johanna-Pascale; Cantin, Léo; Prud’Homme, Michel; Langlois, Mélanie; Macoir, Joël

    2015-01-01

    ...) and levodopa intake on vowel articulation in dysarthric speakers with Parkinson’s disease (PD). Methods. Vowel articulation was assessed in seven Quebec French speakers diagnosed with idiopathic PD who underwent STN DBS...

  13. Articulatory Changes in Vowel Production following STN DBS and Levodopa Intake in Parkinson's Disease

    National Research Council Canada - National Science Library

    Martel Sauvageau, Vincent; Roy, Johanna-Pascale; Cantin, Léo; Prud'Homme, Michel; Langlois, Mélanie; Macoir, Joël

    2015-01-01

    ...) and levodopa intake on vowel articulation in dysarthric speakers with Parkinson's disease (PD). Methods. Vowel articulation was assessed in seven Quebec French speakers diagnosed with idiopathic PD who underwent STN DBS...

  14. Comparison of blood microsampling with DBS and conventional blood collection techniques used in a midazolam biostudy.

    Science.gov (United States)

    Lachance, Sylvain; Théberge, Marie-Claude; Havard, Guy; Anctil, Dominique; Barrière, Olivier; Croteau, Sara; Pellerin, Brigitte; Lévesque, Ann

    2016-04-01

    Quantitative DBS LC-MS/MS assay for midazolam was used to compare two sample collection techniques (venipuncture and finger prick) and the midazolam concentrations measured in plasma samples, DBS and dried plasma spots. Midazolam was extracted from DBS cards and compared with whole blood collected from usual venipuncture. Dried plasma spots were also compared with plasma. The blood volume used as well as the temperature impact during the blood and plasma deposits was evaluated. Midazolam was administrated to six healthy subjects during a clinical trial to obtained blood and plasma samples for the statistical comparison. The method for midazolam using DBS was validated and showed an excellent performance. Excellent correlations were observed when the same collection procedures were used.

  15. Quantitative analysis of methyl and propyl parabens in neonatal DBS using LC–MS/MS

    OpenAIRE

    Yakkundi, Shirish; Mulla, Hussain; Pandya, Hitesh; Turner, Mark A.; McElnay, James

    2016-01-01

    Aim: Excipients are used to overcome the chemical, physical and microbiological challenges posed by developing formulated medicines. Both methyl and propyl paraben are commonly used in pediatric liquid formulations. There is no data on systemic exposure to parabens in neonates. The European Study of Neonatal Exposure to Excipients project has investigated this. Results & methodology: DBS sampling was used to collect opportunistic blood samples. Parabens were extracted from the DBS and ana...

  16. Articulatory Changes in Vowel Production following STN DBS and Levodopa Intake in Parkinson’s Disease

    OpenAIRE

    Vincent Martel Sauvageau; Johanna-Pascale Roy; Léo Cantin; Michel Prud’Homme; Mélanie Langlois; Joël Macoir

    2015-01-01

    Purpose. To investigate the impact of deep brain stimulation of the subthalamic nucleus (STN DBS) and levodopa intake on vowel articulation in dysarthric speakers with Parkinson's disease (PD). Methods. Vowel articulation was assessed in seven Quebec French speakers diagnosed with idiopathic PD who underwent STN DBS. Assessments were conducted on- and off-medication, first prior to surgery and then 1 year later. All recordings were made on-stimulation. Vowel articulation was measured using ac...

  17. Characterisation of a Sr-90 based electron monochromator

    CERN Document Server

    Arfaoui, S; CERN; Casella, C; ETH Zurich

    2015-01-01

    This note describes the characterisation of an energy filtered Sr-90 source to be used in laboratory studies that require Minimum Ionising Particles (MIP) with a kinetic energy of up to approx. 2 MeV. The energy calibration was performed with a LYSO scintillation crystal read out by a digital Silicon Photomultiplier (dSiPM). The LYSO/dSiPM set-up was pre-calibrated using a Na-22 source. After introducing the motivation behind the usage of such a device, this note presents the principle and design of the electron monochromator as well as its energy and momentum characterisation.

  18. Passive Copy-Move Forgery Detection Using Halftoning-based Block Truncation Coding Feature

    Science.gov (United States)

    Harjito, Bambang; Prasetyo, Heri

    2017-06-01

    This paper presents a new method on passive copy-move forgery detection by exploiting the effectiveness and usability of Halftoning-based Block Truncation Coding (HBTC) image feature. Copy-move forgery detection precisely locates the large size or flat tampered regions of an image. On our method, the tampered input image is firstly divided into several overlapping image blocks to construct the image feature descriptors. Each image block is further divided into several non-overlapping image blocks for processing HBTC. Two image feature descriptors, namely Color Feature (CF) and Bit Pattern Feature (BF) are computed from the HBTC compressed data-stream of each image block. Lexicography sorting rearranges the image feature descriptors in ascending manner for whole image. The similarity between some tampered image regions is measured based on their CF and BF under specific shift frequency threshold. As documented in the experimental results, the proposed method yields a promising result for detecting the tampered or copy-move forgery regions. It has proved that the HBTC is not only suitable for image compression, but it can also be used in the copy-move forgery detection.

  19. Vibrational stability of a cryocooled horizontal double-crystal monochromator

    Science.gov (United States)

    Kristiansen, Paw; Johansson, Ulf; Ursby, Thomas; Jensen, Brian Norsk

    2016-01-01

    The vibrational stability of a horizontally deflecting double-crystal monochromator (HDCM) is investigated. Inherently a HDCM will preserve the vertical beam stability better than a ‘normal’ vertical double-crystal monochromator as the vibrations of a HDCM will almost exclusively affect the horizontal stability. Here both the relative pitch vibration between the first and second crystal and the absolute pitch vibration of the second crystal are measured. All reported measurements are obtained under active cooling by means of flowing liquid nitrogen (LN2). It is found that it is favorable to circulate the LN2 at high pressures and low flow rates (up to 5.9 bar and down to 3 l min−1 is tested) to attain low vibrations. An absolute pitch stability of the second crystal of 18 nrad RMS, 2–2500 Hz, and a relative pitch stability between the two crystals of 25 nrad RMS, 1–2500 Hz, is obtained under cryocooling conditions that allow for 1516 W to be adsorbed by the LN2 before it vaporizes. PMID:27577758

  20. Validation of the Use of Dried Blood Spot (DBS Method to Assess Vitamin A Status

    Directory of Open Access Journals (Sweden)

    Elham Fallah

    2012-12-01

    Full Text Available Background: Vitamin A deficiency is an important dietary deficiency in the world. Thus, the ne-cessity of screening for deficient populations is obvious. This paper introduces a fast, cheap and relatively reliable method called “dried blood spot” (DBS method in screening the deficient populations. The validity of this method for retinol measurement was investigated.Method: The “precision” and “agreement” criteria of the DBS method were assessed. The preci-sion was calculated and compared with those of plasma using F-test. The agreement was eva-luated using Bland-Altman plot.Results: The imprecision of retinol measurements in dried spots was not significantly different from those of the control (plasma. A good correlation coefficient (r2=0.78 was obtained for dried spots’ retinol measurements versus plasma’s retinol analysis (P < 0.01. Paired t-test showed no significant difference between the DBS and retinol methods on a group level. Imprecision of DBS measurement was acceptable, compared to that of the plasma method. The difference be-tween these two methods was not statistically significant on a group level.Conclusion: Application of DBS standard samples, in which a part of the plasma was replaced with the artificial plasma, was shown to be a reliable calibration mean for retinol measurements in DBS samples. Retinol in dried spots was stable for 90 days. Overall, the DBS method provided a precise measurement of retinol, showing results that were comparable with the measurement of retinol in plasma.

  1. Performance of a beam-multiplexing diamond crystal monochromator at the Linac Coherent Light Source

    DEFF Research Database (Denmark)

    Zhu, Diling; Feng, Yiping; Stoupin, Stanislav

    2014-01-01

    A double-crystal diamond monochromator was recently implemented at the Linac Coherent Light Source. It enables splitting pulses generated by the free electron laser in the hard x-ray regime and thus allows the simultaneous operations of two instruments. Both monochromator crystals are High-Pressu...

  2. Microcontroller-based servo for two-crystal X-ray monochromators.

    Science.gov (United States)

    Siddons, D P

    1998-05-01

    Microcontrollers have become increasingly easy to incorporate into instruments as the architectures and support tools have developed. The PIC series is particularly easy to use, and this paper describes a controller used to stabilize the output of a two-crystal X-ray monochromator at a given offset from its peak intensity position, as such monochromators are generally used.

  3. Verbal Memory Decline following DBS for Parkinson’s Disease: Structural Volumetric MRI Relationships

    Science.gov (United States)

    Geevarghese, Ruben; Lumsden, Daniel E.; Costello, Angela; Hulse, Natasha; Ayis, Salma; Samuel, Michael; Ashkan, Keyoumars

    2016-01-01

    Background Parkinson’s disease is a chronic degenerative movement disorder. The mainstay of treatment is medical. In certain patients Deep Brain Stimulation (DBS) may be offered. However, DBS has been associated with post-operative neuropsychology changes, especially in verbal memory. Objectives Firstly, to determine if pre-surgical thalamic and hippocampal volumes were related to verbal memory changes following DBS. Secondly, to determine if clinical factors such as age, duration of symptoms or motor severity (UPDRS Part III score) were related to verbal memory changes. Methods A consecutive group of 40 patients undergoing bilateral Subthalamic Nucleus (STN)-DBS for PD were selected. Brain MRI data was acquired, pre-processed and structural volumetric data was extracted using FSL. Verbal memory test scores for pre- and post-STN-DBS surgery were recorded. Linear regression was used to investigate the relationship between score change and structural volumetric data. Results A significant relationship was demonstrated between change in List Learning test score and thalamic (left, p = 0.02) and hippocampal (left, p = 0.02 and right p = 0.03) volumes. Duration of symptoms was also associated with List Learning score change (p = 0.02 to 0.03). Conclusion Verbal memory score changes appear to have a relationship to pre-surgical MRI structural volumetric data. The findings of this study provide a basis for further research into the use of pre-surgical MRI to counsel PD patients regarding post-surgical verbal memory changes. PMID:27557088

  4. Articulatory Changes in Vowel Production following STN DBS and Levodopa Intake in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Vincent Martel Sauvageau

    2015-01-01

    Full Text Available Purpose. To investigate the impact of deep brain stimulation of the subthalamic nucleus (STN DBS and levodopa intake on vowel articulation in dysarthric speakers with Parkinson’s disease (PD. Methods. Vowel articulation was assessed in seven Quebec French speakers diagnosed with idiopathic PD who underwent STN DBS. Assessments were conducted on- and off-medication, first prior to surgery and then 1 year later. All recordings were made on-stimulation. Vowel articulation was measured using acoustic vowel space and formant centralization ratio. Results. Compared to the period before surgery, vowel articulation was reduced after surgery when patients were off-medication, while it was better on-medication. The impact of levodopa intake on vowel articulation changed with STN DBS: before surgery, levodopa impaired articulation, while it no longer had a negative effect after surgery. Conclusions. These results indicate that while STN DBS could lead to a direct deterioration in articulation, it may indirectly improve it by reducing the levodopa dose required to manage motor symptoms. These findings suggest that, with respect to speech production, STN DBS and levodopa intake cannot be investigated separately because the two are intrinsically linked. Along with motor symptoms, speech production should be considered when optimizing therapeutic management of patients with PD.

  5. Articulatory Changes in Vowel Production following STN DBS and Levodopa Intake in Parkinson's Disease.

    Science.gov (United States)

    Martel Sauvageau, Vincent; Roy, Johanna-Pascale; Cantin, Léo; Prud'Homme, Michel; Langlois, Mélanie; Macoir, Joël

    2015-01-01

    Purpose. To investigate the impact of deep brain stimulation of the subthalamic nucleus (STN DBS) and levodopa intake on vowel articulation in dysarthric speakers with Parkinson's disease (PD). Methods. Vowel articulation was assessed in seven Quebec French speakers diagnosed with idiopathic PD who underwent STN DBS. Assessments were conducted on- and off-medication, first prior to surgery and then 1 year later. All recordings were made on-stimulation. Vowel articulation was measured using acoustic vowel space and formant centralization ratio. Results. Compared to the period before surgery, vowel articulation was reduced after surgery when patients were off-medication, while it was better on-medication. The impact of levodopa intake on vowel articulation changed with STN DBS: before surgery, levodopa impaired articulation, while it no longer had a negative effect after surgery. Conclusions. These results indicate that while STN DBS could lead to a direct deterioration in articulation, it may indirectly improve it by reducing the levodopa dose required to manage motor symptoms. These findings suggest that, with respect to speech production, STN DBS and levodopa intake cannot be investigated separately because the two are intrinsically linked. Along with motor symptoms, speech production should be considered when optimizing therapeutic management of patients with PD.

  6. DBS imaging and GMTI in a wideband airborne mechanic scanning radar

    Institute of Scientific and Technical Information of China (English)

    LI Yan-ping; XING Meng-dao; BAO Zheng

    2006-01-01

    A principle for choosing the coherent integration number and an improved Doppler beam sharpening (DBS)imaging algorithm for mechanic scanning radar are presented in this paper.By compensating the range migration in wideband airborne mechanic scanning radar,the proposed DBS imaging algorithm can efficiently improve the resolution of a DBS image.In addition,based on the characteristic that the echo from the moving target will be modulated by the antenna pattern,a novel method used to locate the moving target is also presented,which begins with the sub-aperture moving target detection followed by the sliding window detection.Proper location can be achieved by using this method.Finally,the results on real radar data are provided to demonstrate the effectiveness of these proposed methods.

  7. Links to Other DBs (based on PubChem) - NBDC NikkajiRDF | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available imple search URL - Data acquisition method The data was created from the mapping ...List Contact us NBDC NikkajiRDF Links to Other DBs (based on PubChem) Data detail Data name Links to Other D...ckathon ). Data file File name: NBDC_NikkajiRDF_link2OtherDBs_basedOnPubChem.tar.gz File URL: ftp://ftp.bios...ciencedbc.jp/archive/nikkaji/LATEST/NBDC_NikkajiRDF_link2OtherDBs_basedOnPubChem.tar.gz File size: 46.1 MB S... Policy | Contact Us Links to Other DBs (based on PubChem) - NBDC NikkajiRDF | LSDB Archive ...

  8. MACS low-background doubly focusing neutron monochromator

    CERN Document Server

    Smee, S A; Scharfstein, G A; Qiu, Y; Brand, P C; Anand, D K; Broholm, C L

    2002-01-01

    A novel doubly focusing neutron monochromator has been developed as part of the Multi-Analyzer Crystal Spectrometer (MACS) at the NIST Center for Neutron Research. The instrument utilizes a unique vertical focusing element that enables active vertical and horizontal focusing with a large, 357-crystal (1428 cm sup 2), array. The design significantly reduces the amount of structural material in the beam path as compared to similar instruments. Optical measurements verify the excellent focal performance of the device. Analytical and Monte Carlo simulations predict that, when mounted at the NIST cold-neutron source, the device should produce a monochromatic beam (DELTA E=0.2 meV) with flux phi>10 sup 8 n/cm sup 2 s. (orig.)

  9. SUMS: synchronous undulator-monochromator scans at Synchrotron Soleil.

    Science.gov (United States)

    Izquierdo, Manuel; Hardion, Vincent; Renaud, Guillaume; Chapuis, Lilian; Millet, Raphael; Langlois, Florent; Marteau, Fabrice; Chauvet, Christian

    2012-07-01

    A strategy for performing synchronous undulator-monochromator scans (SUMS) compatible with the control system of Synchrotron Soleil has been developed. The implementation of the acquisition scheme has required the development of an electronic interface between the undulator and the beamline. The characterization of delays and jitters in the synchronous movement of various motor axes has motivated the development of a new electronic synchronization scheme among various axes, including the case when one of the axes is electronically accessible in `read-only' mode. A software prototype has been developed to allow the existing hard continuous software to work in user units. The complete strategy has been implemented and successfully tested at the TEMPO beamline.

  10. Monochromator-Based Absolute Calibration of Radiation Thermometers

    Science.gov (United States)

    Keawprasert, T.; Anhalt, K.; Taubert, D. R.; Hartmann, J.

    2011-08-01

    A monochromator integrating-sphere-based spectral comparator facility has been developed to calibrate standard radiation thermometers in terms of the absolute spectral radiance responsivity, traceable to the PTB cryogenic radiometer. The absolute responsivity calibration has been improved using a 75 W xenon lamp with a reflective mirror and imaging optics to a relative standard uncertainty at the peak wavelength of approximately 0.17 % ( k = 1). Via a relative measurement of the out-of-band responsivity, the spectral responsivity of radiation thermometers can be fully characterized. To verify the calibration accuracy, the absolutely calibrated radiation thermometer is used to measure Au and Cu freezing-point temperatures and then to compare the obtained results with the values obtained by absolute methods, resulting in T - T 90 values of +52 mK and -50 mK for the gold and copper fixed points, respectively.

  11. My 25 Stimulating Years with DBS in Parkinson’s Disease

    Science.gov (United States)

    Hariz, Marwan

    2017-01-01

    The year 2017 marks the 30th anniversary of the birth of modern deep brain stimulation (DBS), which was introduced by Benabid, Pollak et al. in 1987, initially targeting the motor thalamus to treat tremor, and subsequently targeting the subthalamic nucleus (STN) for treatment of symptoms of advanced Parkinson’s disease (PD). STN DBS is undoubtedly “the most important discovery since levodopa”, as stated by David Marsden in 1994. In 2014, The Lasker– DeBakey Clinical Medical Research Award to “honor two scientists who developed deep brain stimulation of the subthalamic nucleus”, was bestowed upon Benabid and DeLong. STN DBS remains today the main surgical procedure for PD, due to its effectiveness in ameliorating PD symptoms and because it is the only surgical procedure for PD that allows a radical decrease in medication. Future improvements of DBS include the possibility to deliver a “closed-loop”, “on demand” stimulation, as highly preliminary studies suggest that it may improve both axial and appendicular symptoms and reduce side effects such as dysarthria. Even though DBS of the subthalamic nucleus is the main surgical procedure used today for patients with PD, all patients are not suitable for STN DBS; as a functional neurosurgeon performing since more than 25 years various surgical procedures the aim of which is not to save life but to improve the patient’s quality of life, I consider that the surgery should be tailored to the patient’s individual symptoms and needs, and that its safety is paramount. PMID:28282816

  12. Thalamic DBS with a constant-current device in essential tremor: A controlled clinical trial.

    Science.gov (United States)

    Wharen, Robert E; Okun, Michael S; Guthrie, Barton L; Uitti, Ryan J; Larson, Paul; Foote, Kelly; Walker, Harrison; Marshall, Frederick J; Schwalb, Jason; Ford, Blair; Jankovic, Joseph; Simpson, Richard; Dashtipour, Khashayar; Phibbs, Fenna; Neimat, Joseph S; Stewart, R Malcolm; Peichel, DeLea; Pahwa, Rajesh; Ostrem, Jill L

    2017-07-01

    This study of thalamic deep brain stimulation (DBS) investigated whether a novel constant-current device improves tremor and activities of daily living (ADL) in patients with essential tremor (ET). A prospective, controlled, multicenter study was conducted at 12 academic centers. We investigated the safety and efficacy of unilateral and bilateral constant-current DBS of the ventralis intermedius (VIM) nucleus of the thalamus in patients with essential tremor whose tremor was inadequately controlled by medications. The primary outcome measure was a rater-blinded assessment of the change in the target limb tremor score in the stimulation-on versus stimulation-off state six months following surgery. Multiple secondary outcomes were assessed at one-year follow-up, including motor, mood, and quality-of-life measures. 127 patients were implanted with VIM DBS. The blinded, primary outcome variable (n = 76) revealed a mean improvement of 1.25 ± 1.26 points in the target limb tremor rating scale (TRS) score in the arm contralateral to DBS (p < 0.001). Secondary outcome variables at one year revealed significant improvements (p ≤ 0.001) in quality of life, depression symptoms, and ADL scores. Forty-seven patients had a second contralateral VIM-DBS, and this group demonstrated reduction in second-sided tremor at 180 days (p < 0.001). Serious adverse events related to the surgery included infection (n = 3), intracranial hemorrhage (n = 3), and device explantation (n = 3). Unilateral and bilateral constant-current VIM DBS significantly improves upper extremity tremor, ADL, quality of life, and depression in patients with severe ET. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Analysis of benzodiazepines and their metabolites using DBS cards and LC-MS/MS.

    Science.gov (United States)

    Lee, Heesang; Park, Yujin; Jo, Jiyeong; In, Sangwhan; Park, Yonghoon; Kim, Eunmi; Pyo, Jaesung; Choe, Sanggil

    2015-10-01

    Dried Blood Spot (DBS) has been used a blood extraction method for inherited metabolic disorder screening since 1960s. With introduction of LC-MS/MS, not only DBS could be used to analysis drugs in small blood volume, but in various fields, such as toxicology, drug therapeutic monitoring, drug diagnostic screening, and illicit drugs. In toxicology field, many drugs (e.g. benzodiazepines, acetaminophen, small molecule drugs) have been tested with DBS. Compared with earlier blood extraction methods (SPE and LLE), DBS has lots of advantages; lower blood volume (less than 50μL), shorter analysis time caused by a more concise analysis procedure and lower cost. We optimized the DBS procedure and LC-MS/MS conditions for 18 benzodiazepines, seven benzodiazepine metabolites, and one z-drug (zolpidem) analysis in blood. 30μL of whole blood was spotted on FTA DMPK card C and dried for 2h in a desiccator. A 6-mm disk was punched and vortexed for 1min in a centrifuge tube with 300μL methanol/acetonitrile mixture (1:1, v/v). After evaporation, redissolved in 100μL mobile phase of LC-MS/MS and 5μL was injected. In the analysis for 26 target compounds in blood, all of the method validation parameters - LLOD, LLOQ, accuracy (intra- and inter-assay), and precision (intra- and inter-assay) - were satisfied with method validation criteria, within 15%. The results of matrix effect, recovery, and process efficiency were good. We developed a fast and reliable sample preparation method using DBS for 26 benzodiazepines, benzodiazepine metabolites, and z-drug (zolpidem).

  14. Electrochemical Behaviour of a PPy(DBS)/Polyacrylonitrile (PAN):LITF:EC:PC/ Li Cell

    DEFF Research Database (Denmark)

    Vidanapathirana, K.; Skaarup, Steen; West, K.

    2006-01-01

    The electrochemical behaviour of Li rechargeable cells with Polypyrrole (PPy) as the cathode material was investigated using cyclic voltammetry. The PPy used was doped with the large surfactant anion dodecyl benzenesulphonate (DBS-). The cells were constructed with PAN:LiTF:EC:PC gel electrolyte...... with Li as anode. The results indicate that during the first reduction, cations are inserted into the PPy film forming LiDBS neutral salt. During the next oxidation/reduction cycles, the mechanism then switches to anion movement. Cyclic voltammetry studies also verified that complete electrochemical...

  15. Using STN DBS and medication reduction as a strategy to treat pathological gambling in Parkinson's disease.

    Science.gov (United States)

    Bandini, Fabio; Primavera, Alberto; Pizzorno, Matteo; Cocito, Leonardo

    2007-08-01

    We describe two patients with Parkinson's disease (PD) who developed clinical criteria of pathological gambling addiction in the setting of increased dopamine replacement therapy (levodopa and dopamine agonist medications). The second patient showed also signs of dopamine dysregulation syndrome, with an addiction to dopaminergic medication. Neither patients responded to the standard therapy for gambling behavior, but dramatically improved after bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) and early postoperative withdrawal of dopaminergic therapy. The possible therapeutic role of subthalamic nucleus deep brain stimulation (STN-DBS) on such a disabling behavior needs to be investigated prospectively.

  16. Double-crystal monochromator as the first optical element in BESSRC-CAT beamlines (abstract)

    Science.gov (United States)

    Beno, Mark A.; Ramanathan, Mohan

    1996-09-01

    The first optical element in the BESSRC-CAT beamlines at the Advanced Photon Source will be a monochromator, so that a standard design for this critical component is advantageous. The monochromator we have designed is a double-crystal, fixed-exit scheme with a constant offset designed for UHV operation, thereby allowing windowless operation of the beamlines. The crystals are mounted on a turntable with the first crystal at the center of rotation. A mechanical linkage is used to correctly position the second crystal and maintain a constant offset. The main drive for the rotary motion is provided by a vacuum-compatible Huber goniometer isolated from the main vacuum chamber. Rotary motion of the primary monochromator stage is accomplished by using two adjacent vacuum chambers connected only by the small annular opening around a hollow stainless steel shaft, which connects the Huber goniometer to the turntable on which the crystals are mounted. The design of the monochromator is such that it can accommodate both water and liquid nitrogen cooling for the crystal optics. The basic design for the monochromator linkage mechanism will be presented along with details of the monochromator chamber. The results of initial optical tests of the monochromator system using tilt sensors and a precision autocollimator will also be given.

  17. The development of a 200 kV monochromated field emission electron source

    Energy Technology Data Exchange (ETDEWEB)

    Mukai, Masaki, E-mail: mmukai@jeol.co.jp [JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo 196-8558 (Japan); Kim, Judy S. [University of Oxford, Department of Materials, Parks Road, Oxford, OX1 3PH (United Kingdom); Omoto, Kazuya; Sawada, Hidetaka; Kimura, Atsushi; Ikeda, Akihiro; Zhou, Jun; Kaneyama, Toshikatsu [JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo 196-8558 (Japan); Young, Neil P.; Warner, Jamie H.; Nellist, Peter D.; Kirkland, Angus I. [University of Oxford, Department of Materials, Parks Road, Oxford, OX1 3PH (United Kingdom)

    2014-05-01

    We report the development of a monochromator for an intermediate-voltage aberration-corrected electron microscope suitable for operation in both STEM and TEM imaging modes. The monochromator consists of two Wien filters with a variable energy selecting slit located between them and is located prior to the accelerator. The second filter cancels the energy dispersion produced by the first filter and after energy selection forms a round monochromated, achromatic probe at the specimen plane. The ultimate achievable energy resolution has been measured as 36 meV at 200 kV and 26 meV at 80 kV. High-resolution Annular Dark Field STEM images recorded using a monochromated probe resolve Si–Si spacings of 135.8 pm using energy spreads of 218 meV at 200 kV and 217 meV at 80 kV respectively. In TEM mode an improvement in non-linear spatial resolution to 64 pm due to the reduction in the effects of partial temporal coherence has been demonstrated using broad beam illumination with an energy spread of 134 meV at 200 kV. - Highlights: • Monochromator for 200 kV aberration corrected TEM and STEM was developed. • Monochromator produces monochromated and achromatic probe at specimen plane. • Ultimate energy resolution was measured to be 36 meV at 200 kV and 26 meV at 80 kV. • Atomic resolution STEM images were recorded using monochromated electron probe. • Improvements of TEM resolution were confirmed using monochromated illumination.

  18. Realisation of a novel crystal bender for a fast double crystal monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Zaeper, R.; Richwin, M. E-mail: richwin@uni-wuppertal.de; Wollmann, R.; Luetzenkirchen-Hecht, D.; Frahm, R

    2001-07-21

    A novel crystal bender for an X-ray undulator beamline as part of a fast double crystal monochromator development for full EXAFS energy range was characterized. Rocking curves of the monochromator crystal system were recorded under different heat loads and bending forces of the indirectly cooled first Si(1 1 1) crystal. The monochromator development implements new piezo-driven tilt tables with wide angular range to adjust the crystals' Bragg angles and a high pressure actuated bender mechanism for the first crystal.

  19. Realisation of a novel crystal bender for a fast double crystal monochromator

    CERN Document Server

    Zaeper, R; Wollmann, R; Luetzenkirchen-Hecht, D; Frahm, R

    2001-01-01

    A novel crystal bender for an X-ray undulator beamline as part of a fast double crystal monochromator development for full EXAFS energy range was characterized. Rocking curves of the monochromator crystal system were recorded under different heat loads and bending forces of the indirectly cooled first Si(1 1 1) crystal. The monochromator development implements new piezo-driven tilt tables with wide angular range to adjust the crystals' Bragg angles and a high pressure actuated bender mechanism for the first crystal.

  20. Optimization of Monochromated TEM for Ultimate Resolution Imaging and Ultrahigh Resolution Electron Energy Loss Spectroscopy

    KAUST Repository

    Lopatin, Sergei

    2017-09-01

    The performance of a monochromated transmission electron microscope with Wien type monochromator is optimized to achieve an extremely narrow energy spread of electron beam and an ultrahigh energy resolution with spectroscopy. The energy spread in the beam is improved by almost an order of magnitude as compared to specified values. The optimization involves both the monochromator and the electron energy loss detection system. We demonstrate boosted capability of optimized systems with respect to ultra-low loss EELS and sub-angstrom resolution imaging (in a combination with spherical aberration correction).

  1. Intraoperative MR-guided DBS implantation for treating PD and ET

    Science.gov (United States)

    Liu, Haiying; Maxwell, Robert E.; Truwit, Charles L.

    2001-05-01

    Deep brain stimulator (DBS) implantation is a promising treatment alternative for suppressing the motor tremor symptoms in Parkinson disease (PD) patient. The main objective is to develop a minimally invasive approach using high spatial resolution and soft-tissue contrast MR imaging techniques to guide the surgical placement of DBS. In the MR-guided procedure, the high spatial resolution MR images were obtained intra-operatively and used to target stereotactically a specific deep brain location. The neurosurgery for craniotomy was performed in the front of the magnet outside of the 10 Gauss line. Aided with positional registration assembly for the stereotactic head frame, the target location (VIM or GPi or STN) in deep brain areas was identified and measured from the MR images in reference to the markers in the calibration assembly of the head frame before the burrhole prep. In 20 patients, MR- guided DBS implantations have been performed according to the new methodology. MR-guided DBS implantation at high magnetic field strength has been shown to be feasible and desirable. In addition to the improved outcome, this offers a new surgical approach in which intra-operative visualization is possible during intervention, and any complications such as bleeding can be assessed in situ immediately prior to dural closure.

  2. MRI-Based Multiscale Model for Electromagnetic Analysis in the Human Head with Implanted DBS

    Directory of Open Access Journals (Sweden)

    Maria Ida Iacono

    2013-01-01

    Full Text Available Deep brain stimulation (DBS is an established procedure for the treatment of movement and affective disorders. Patients with DBS may benefit from magnetic resonance imaging (MRI to evaluate injuries or comorbidities. However, the MRI radio-frequency (RF energy may cause excessive tissue heating particularly near the electrode. This paper studies how the accuracy of numerical modeling of the RF field inside a DBS patient varies with spatial resolution and corresponding anatomical detail of the volume surrounding the electrodes. A multiscale model (MS was created by an atlas-based segmentation using a 1 mm3 head model (mRes refined in the basal ganglia by a 200 μm2 ex-vivo dataset. Four DBS electrodes targeting the left globus pallidus internus were modeled. Electromagnetic simulations at 128 MHz showed that the peak of the electric field of the MS doubled (18.7 kV/m versus 9.33 kV/m and shifted 6.4 mm compared to the mRes model. Additionally, the MS had a sixfold increase over the mRes model in peak-specific absorption rate (SAR of 43.9 kW/kg versus 7 kW/kg. The results suggest that submillimetric resolution and improved anatomical detail in the model may increase the accuracy of computed electric field and local SAR around the tip of the implant.

  3. Tremor recording and analysis as a tool for target localisation in thalamotomy and DBS for tremor

    NARCIS (Netherlands)

    Journee, HL; Hamoen, DJ; Staal, MJ; Sclabassi, R; Haaxma, R; Elands, A; Hummel, JJJ; Boom, H; Robinson, C; Rutten, W; Neuman, M; Wijkstra, H

    1997-01-01

    The objective of this work was to design and use a tremor and analysis system for stereotactic thalamotomy and thalamus stimulation (DBS). A notebook PC based system was developed. The tremor was measured by accelero-transducers or EMG. The method was used to confirm the definitive localization of

  4. MRI-Based Multiscale Model for Electromagnetic Analysis in the Human Head with Implanted DBS

    Science.gov (United States)

    Iacono, Maria Ida; Makris, Nikos; Mainardi, Luca; Angelone, Leonardo M.; Bonmassar, Giorgio

    2013-01-01

    Deep brain stimulation (DBS) is an established procedure for the treatment of movement and affective disorders. Patients with DBS may benefit from magnetic resonance imaging (MRI) to evaluate injuries or comorbidities. However, the MRI radio-frequency (RF) energy may cause excessive tissue heating particularly near the electrode. This paper studies how the accuracy of numerical modeling of the RF field inside a DBS patient varies with spatial resolution and corresponding anatomical detail of the volume surrounding the electrodes. A multiscale model (MS) was created by an atlas-based segmentation using a 1 mm3 head model (mRes) refined in the basal ganglia by a 200 μm2 ex-vivo dataset. Four DBS electrodes targeting the left globus pallidus internus were modeled. Electromagnetic simulations at 128 MHz showed that the peak of the electric field of the MS doubled (18.7 kV/m versus 9.33 kV/m) and shifted 6.4 mm compared to the mRes model. Additionally, the MS had a sixfold increase over the mRes model in peak-specific absorption rate (SAR of 43.9 kW/kg versus 7 kW/kg). The results suggest that submillimetric resolution and improved anatomical detail in the model may increase the accuracy of computed electric field and local SAR around the tip of the implant. PMID:23956789

  5. Predictors of cognitive and psychosocial outcome after STN DBS in Parkinson's Disease

    NARCIS (Netherlands)

    Smeding, H.M.M.; Speelman, J.D.; Huizenga, H.M.; Schuurman, P.R.; Schmand, B.

    2011-01-01

    Objective: To find predictors of cognitive decline and quality of life one year after bilateral subthalamic nucleus stimulation (STN DBS) in Parkinson’s disease (PD). Methods: A total of 105 patients were evaluated with a comprehensive neuropsychological assessment before and 12 months after surgery

  6. Tremor recording and analysis as a tool for target localisation in thalamotomy and DBS for tremor

    NARCIS (Netherlands)

    Journee, HL; Hamoen, DJ; Staal, MJ; Sclabassi, R; Haaxma, R; Elands, A; Hummel, JJJ; Boom, H; Robinson, C; Rutten, W; Neuman, M; Wijkstra, H

    1997-01-01

    The objective of this work was to design and use a tremor and analysis system for stereotactic thalamotomy and thalamus stimulation (DBS). A notebook PC based system was developed. The tremor was measured by accelero-transducers or EMG. The method was used to confirm the definitive localization of t

  7. Effect of Deep Brain Stimulation on Parkinson's Nonmotor Symptoms following Unilateral DBS: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Nelson Hwynn

    2011-01-01

    Full Text Available Parkinson’s disease (PD management has traditionally focused largely on motor symptoms. Deep brain stimulation (DBS of the subthalamic nucleus (STN and globus pallidus internus (GPi are effective treatments for motor symptoms. Nonmotor symptoms (NMSs may also profoundly affect the quality of life. The purpose of this pilot study was to evaluate NMS changes pre- and post-DBS utilizing two recently developed questionnaires. Methods. NMS-Q (questionnaire and NMS-S (scale were administered to PD patients before/after unilateral DBS (STN/GPi targets. Results. Ten PD patients (9 STN implants, 1 GPi implant were included. The three most frequent NMS symptoms identified utilizing NMS-Q in pre-surgical patients were gastrointestinal (100%, sleep (100%, and urinary (90%. NMS sleep subscore significantly decreased (−1.6 points ± 1.8, =0.03. The three most frequent NMS symptoms identified in pre-surgical patients using NMS-S were gastrointestinal (90%, mood (80%, and cardiovascular (80%. The largest mean decrease of NMS scores was seen in miscellaneous symptoms (pain, anosmia, weight change, and sweating (−7 points ± 8.7, and cardiovascular/falls (−1.9, =0.02. Conclusion. Non-motor symptoms improved on two separate questionnaires following unilateral DBS for PD. Future studies are needed to confirm these findings and determine their clinical significance as well as to examine the strengths/weaknesses of each questionnaire/scale.

  8. An Inter-Comparison Study of Multi- and DBS Lidar Measurements in Complex Terrain

    DEFF Research Database (Denmark)

    Pauscher, Lukas; Vasiljevic, Nikola; Callies, Doron

    2016-01-01

    WindScanners were focused on one point next to a reference mast in complex terrain. This multi-lidar (ML) technique is also compared to a profiling lidar using the Doppler beam swinging (DBS) method. First- and second-order statistics of the radial wind velocities from the individual instruments...

  9. Aberration corrected and monochromated environmental transmission electron microscopy: challenges and prospects for materials science

    DEFF Research Database (Denmark)

    Hansen, Thomas Willum; Wagner, Jakob Birkedal; Dunin-Borkowski, Rafal E.

    2010-01-01

    The latest generation of environmental transmission electron microscopes incorporates aberration correctors and monochromators, allowing studies of chemical reactions and growth processes with improved spatial resolution and spectral sensitivity. Here, we describe the performance of such an instr......The latest generation of environmental transmission electron microscopes incorporates aberration correctors and monochromators, allowing studies of chemical reactions and growth processes with improved spatial resolution and spectral sensitivity. Here, we describe the performance...

  10. IMCA-CAT BM first monochromator crystal optimization

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, I.N.; Cimpoes, S.; Chrzas, J. [CSRRI, Illinois Institute of Technology, 3301 S. Dearborn Street, Chicago, Il 60616 (United States)

    1996-09-01

    The high heat load at the surfaces of the first x-ray optical elements at the APS requires special measures to be taken to more completely utilize the beam. A conceptually new design for such an element, proposed, realized, and tested by M. Hart and conveniently called {open_quote}{open_quote}matchbox,{close_quote}{close_quote} is to be implemented at the IMCA-CAT BM beamline as the first monochromator crystal. The requirements of the IMCA-CAT companies for the BM beamline dictate that an optimization of the design is made for a given x-ray energy range E=13 keV {plus_minus}1 keV. A modification of the original design to improve the vacuum compatibility of the device was made in collaboration with M. Hart. A FEA optimization of the geometry is made using the ALGOR and ABAQUS programs. Determination of the resulting slopes and the useful crystal surface after the best compensation of the thermal distortions are also made. The surface profile obtained by the FEA study was used to perform a ray-tracing analysis of the IMCA-CAT BM beamline. The results of the ray-tracing study will be presented. {copyright} {ital 1996 American Institute of Physics.}

  11. Monochromator-Based Absolute Calibration of a Standard Radiation Thermometer

    Science.gov (United States)

    Mantilla, J. M.; Hernanz, M. L.; Campos, J.; Martín, M. J.; Pons, A.; del Campo, D.

    2014-04-01

    Centro Español de Metrología (CEM) is disseminating the International Temperature Scale (ITS-90), at high temperatures, by using the fixed points of Ag and Cu and a standard radiation thermometer. However, the future mise-en-pratique for the definition of the kelvin ( MeP-K) will include the dissemination of the kelvin by primary methods and by indirect approximations capable of exceptionally low uncertainties or increased reliability. Primary radiometry is, at present, able to achieve uncertainties competitive with the ITS-90 above the silver point with one of the possible techniques the calibration for radiance responsivity of an imaging radiometer (radiance method). In order to carry out this calibration, IO-CSIC (Spanish Designated Institute for luminous intensity and luminous flux) has collaborated with CEM, allowing traceability to its cryogenic radiometer. A monochromator integrating sphere-based spectral comparator facility has been used to calibrate one of the CEM standard radiation thermometers. The absolute calibrated standard radiation thermometer has been used to determine the temperatures of the fixed points of Cu, Co-C, Pt-C, and Re-C. The results obtained are 1357.80 K, 1597.10 K, 2011.66 K, and 2747.64 K, respectively, with uncertainties ranging from 0.4 K to 1.1 K.

  12. Moessbauer-Fresnel zone plate as nuclear monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Mooney, T.M.; Alp, E.E.; Yun, W.B.

    1992-06-01

    Zone plates currently used in x-ray optics derive their focusing power from (a spatial variation of) the electronic refractive index -- that is, from the collective effect of electronic x-ray-scattering amplitudes. Nuclei also scatter x rays, and resonant nuclear-scattering amplitudes, particularly those associated with Moessbauer fluorescence, can dominate the refractive index for x-rays whose energies are very near the nuclear-resonance energy. A zone plate whose Fresnel zones are filled alternately with {sup 57}Fe and {sup 56}Fe ({sup 57}Fe has a nuclear resonance of natural width {Gamma} = 4.8 nano-eV at 14.413 keV; {sup 56}Fe has no such resonance) has a resonant focusing efficiency; it focuses only those x-rays whose energies are within several {Gamma} of resonance. When followed by an absorbing screen with a small pinhole, such a zone plate can function as a synchrotron-radiation monochromator with an energy resolution of a few parts in 10{sup 12}. The energy-dependent focusing efficiency and the resulting time-dependent response of a resonant zone plate are discussed.

  13. Liquid-crystal displays for medical imaging: a discussion of monochrome versus color

    Science.gov (United States)

    Wright, Steven L.; Samei, Ehsan

    2004-05-01

    A common view is that color displays cannot match the performance of monochrome displays, normally used for diagnostic x-ray imaging. This view is based largely on historical experience with cathode-ray tube (CRT) displays, and does not apply in the same way to liquid-crystal displays (LCDs). Recent advances in color LCD technology have considerably narrowed performance differences with monochrome LCDs for medical applications. The most significant performance advantage of monochrome LCDs is higher luminance, a concern for use under bright ambient conditions. LCD luminance is limited primarily by backlight design, yet to be optimized for color LCDs for medical applications. Monochrome LCDs have inherently higher contrast than color LCDs, but this is not a major advantage under most conditions. There is no practical difference in luminance precision between color and monochrome LCDs, with a slight theoretical advantage for color. Color LCDs can provide visualization and productivity enhancement for medical applications, using digital drive from standard commercial graphics cards. The desktop computer market for color LCDs far exceeds the medical monitor market, with an economy of scale. The performance-to-price ratio for color LCDs is much higher than monochrome, and warrants re-evaluation for medical applications.

  14. High-heat-load monochromator options for the RIXS beamline at the APS with the MBA lattice

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zunping, E-mail: zpliu@anl.gov; Gog, Thomas, E-mail: gog@aps.anl.gov; Stoupin, Stanislav A.; Upton, Mary H.; Ding, Yang; Kim, Jung-Ho; Casa, Diego M.; Said, Ayman H.; Carter, Jason A.; Navrotski, Gary [Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Ave, Lemont, IL 60439 (United States)

    2016-07-27

    With the MBA lattice for APS-Upgrade, tuning curves of 2.6 cm period undulators meet the source requirements for the RIXS beamline. The high-heat-load monochromator (HHLM) is the first optical white beam component. There are four options for the HHLM such as diamond monochromators with refrigerant of either water or liquid nitrogen (LN{sub 2}), and silicon monochromators of either direct or indirect cooling system. Their performances are evaluated at energy 11.215 keV (Ir L-III edge). The cryo-cooled diamond monochromator has similar performance as the water-cooled diamond monochromator because GaIn of the Cu-GaIn-diamond interface becomes solid. The cryo-cooled silicon monochromators perform better, not only in terms of surface slope error due to thermal deformation, but also in terms of thermal capacity.

  15. 单色半色调墨点非规整Clapper-Yule分程模型%Extended Clapper-Yule Spectral Reflectance Model of Monochrome Halftone Image with Irregular Ink Dot

    Institute of Scientific and Technical Information of China (English)

    何晓敏; 王颖; 柯能; 张逸新

    2015-01-01

    目的 研究非规整的墨点(非二值理想墨点)形态对光谱反射率的影响,为预测模型的理论研究提供一个新的思路.方法 通过讨论墨点的非规整形态对网点大小、厚度及油墨透射率的影响,采用二维高斯函数模拟墨点表面的形态,由此建立一个Clapper-Yule扩展模型.结果 模型的数值模拟结果表明墨点的非规整性导致了网点的物理扩大,增加了油墨对光的吸收,降低了最终的光谱反射率.结论 采用Clapper-Yule分程模型对颜色进行预测时需考虑墨点的非规整所带来的物理网点扩大,该模型适用于单色半色调的颜色预测与控制.

  16. SEVERAL PROBLEMS IN DESIGNING DBS SYSTEMS FOR AIRBORNE PULSE DOPPLER RADAR

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Some bases are presented for determining and calculating the airborne pulse doppler radar's DBS system parameters.Major problems discussed here are the limitation to the beam sharpening ratio and azimuth resolution, and the limitation to maximum pitch angle and minimum azimuth angle.Some basic formulas are given for calculating the batch processing period, framescan time and antenna rotating speed.Also discussed are the limiting condition and determining principle of the pulse repetition frequency.

  17. Predictors of cognitive and psychosocial outcome after STN DBS in Parkinson's Disease

    OpenAIRE

    Smeding, H M M; Speelman, J D; Huizenga, H.M.; Schuurman, P R; Schmand, B

    2011-01-01

    Objective: To find predictors of cognitive decline and quality of life one year after bilateral subthalamic nucleus stimulation (STN DBS) in Parkinson’s disease (PD). Methods: A total of 105 patients were evaluated with a comprehensive neuropsychological assessment before and 12 months after surgery. A control group of 40 PD patients was included to control for effects of repeated testing and disease progression. We determined individual changes in cognition, mood and quality of life using a ...

  18. Intraoperative CT verification of electrode localization in DBS surgery in Parkinson's disease

    Directory of Open Access Journals (Sweden)

    P. Sokal

    2015-03-01

    Conclusions: Intraoperative CT is a helpful tool in DBS procedures and enables comparison of preoperative plans with the final trajectory and localization of the tip of electrode visualized in CT in appropriate target. It eliminates necessity of post-op verification outside the operating room. All changes can be done during the procedure. It also allows to rule out the intracerebral haematoma caused by implantation.

  19. Automated assessment of symptom severity changes during deep brain stimulation (DBS) therapy for Parkinson's disease.

    Science.gov (United States)

    Angeles, Paolo; Tai, Yen; Pavese, Nicola; Wilson, Samuel; Vaidyanathan, Ravi

    2017-07-01

    Deep brain stimulation (DBS) is currently being used as a treatment for symptoms of Parkinson's disease (PD). Tracking symptom severity progression and deciding the optimal stimulation parameters for people with PD is extremely difficult. This study presents a sensor system that can quantify the three cardinal motor symptoms of PD - rigidity, bradykinesia and tremor. The first phase of this study assesses whether data recorded from the system during physical examinations can be used to correlate to clinician's severity score using supervised machine learning (ML) models. The second phase concludes whether the sensor system can distinguish differences before and after DBS optimisation by a clinician when Unified Parkinson's Disease Rating Scale (UPDRS) scores did not change. An average accuracy of 90.9 % was achieved by the best ML models in the first phase, when correlating sensor data to clinician's scores. Adding on to this, in the second phase of the study, the sensor system was able to pick up discernible differences before and after DBS optimisation sessions in instances where UPDRS scores did not change.

  20. Obscured clusters.IV. The most massive stars in [DBS2003]179

    CERN Document Server

    Borissova, J; Hanson, M M; Clarke, J R A; Kurtev, R; Ivanov, V D; Penaloza, F; Hillier, D J; Zsargo, J

    2012-01-01

    Aims. We report new results for the massive evolved and main sequence members of the young galactic cluster DBS2003 179. We determine the physical parameters and investigate the high-mass stellar content of the cluster, as well as of its close vicinity. Methods. Our analysis is based on ISAAC/VLT moderate-resolution (R\\approx4000) infrared spectroscopy of the brightest cluster members. We derive stellar parameters for sixteen of the stellar members, using full non-LTE modeling of the obtained spectra. Results. The cluster contains three late WN or WR/LBV stars (Obj 4, Obj 15, and Obj 20:MDM32) and at least 5 OIf and 5 OV stars. According to the Hertzsprung-Russell diagram for DBS2003 179, the WR stars show masses above 85Msun, the OIf stars are between 40 and 80Msun, and the main sequence O stars are >20Msun. There are indications of binarity for Obj 4 and Obj 11, and Obj 3 shows a variable spectrum. The cluster is surrounded by a continuous protostar formation region most probably triggered by DBS2003 179. C...

  1. Double crystal monochromator controlled by integrated computing on BL07A in New SUBARU, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Okui, Masato, E-mail: okui@kohzu.co.jp [Kohzu Precision Co., Ltd., 2-6-15, Kurigi, Asao-ku, Kawasaki-shi, Kanagawa 215-8521 (Japan); Laboratory of Advanced Science and Technology for Industry, University of Hyogo (Japan); Yato, Naoki; Watanabe, Akinobu; Lin, Baiming; Murayama, Norio [Kohzu Precision Co., Ltd., 2-6-15, Kurigi, Asao-ku, Kawasaki-shi, Kanagawa 215-8521 (Japan); Fukushima, Sei, E-mail: FUKUSHIMA.Sei@nims.go.jp [Laboratory of Advanced Science and Technology for Industry, University of Hyogo (Japan); National Institute for Material Sciences (Japan); Kanda, Kazuhiro [Laboratory of Advanced Science and Technology for Industry, University of Hyogo (Japan)

    2016-07-27

    The BL07A beamline in New SUBARU, University of Hyogo, has been used for many studies of new materials. A new double crystal monochromator controlled by integrated computing was designed and installed in the beamline in 2014. In this report we will discuss the unique features of this new monochromator, MKZ-7NS. This monochromator was not designed exclusively for use in BL07A; on the contrary, it was designed to be installed at low cost in various beamlines to facilitate the industrial applications of medium-scale synchrotron radiation facilities. Thus, the design of the monochromator utilized common packages that can satisfy the wide variety of specifications required at different synchrotron radiation facilities. This monochromator can be easily optimized for any beamline due to the fact that a few control parameters can be suitably customized. The beam offset can be fixed precisely even if one of the two slave axes is omitted. This design reduces the convolution of mechanical errors. Moreover, the monochromator’s control mechanism is very compact, making it possible to reduce the size of the vacuum chamber can be made smaller.

  2. Cascade self-seeding scheme with wake monochromator for narrow-bandwidth X-ray FELs

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2010-01-01

    Three different approaches have been proposed so far for production of highly monochromatic X-rays from a baseline XFEL undulator: (i) single-bunch self-seeding scheme with a four crystal monochromator in Bragg reflection geometry; (ii) double-bunch self-seeding scheme with a four-crystal monochromator in Bragg reflection geometry; (iii) single-bunch self-seeding scheme with a wake monochromator. A unique element of the X-ray optical design of the last scheme is the monochromatization of X-rays using a single crystal in Bragg-transmission geometry. A great advantage of this method is that the monochromator introduces no path delay of X-rays. This fact eliminates the need for a long electron beam bypass, or for the creation of two precisely separated, identical electron bunches, as required in the other two self-seeding schemes. In its simplest configuration, the self-seeded XFEL consists of an input undulator and an output undulator separated by a monochromator. In some experimental situations this simplest t...

  3. On the influence of monochromator thermal deformations on X-ray focusing

    Science.gov (United States)

    Antimonov, M. A.; Khounsary, A. M.; Sandy, A. R.; Narayanan, S.; Navrotski, G.

    2016-06-01

    A cooled double crystal monochromator system is used on many high heat load X-ray synchrotron radiation beamlines in order to select, by diffraction, a narrow spectrum of the beam. Thermal deformation of the first crystal monochromator - and the potential loss of beam brightness - is often a concern. However, if downstream beam focusing is planned, the lensing effect of the monochromator must be considered even if thermal deformations are small. In this paper we report on recent experiments at an Advanced Photon Source (APS) beamline that focuses the X-ray beam using compound refractive lenses downstream of an X-ray monochromator system. Increasing the X-ray beam power by increasing the storage ring current from 100 mA to 130 mA resulted in an effective doubling of the focal distance. We show quantitatively that this is due to a lensing effect of the distorted monochromator that results in the creation of a virtual source downstream of the actual source. An analysis of the defocusing and options to mitigate this effect are explored.

  4. On the influence of monochromator thermal deformations on X-ray focusing

    Energy Technology Data Exchange (ETDEWEB)

    Antimonov, M.A. [Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL 60607 (United States); X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Peter the Great St. Petersburg Polytechnic University, Saint Petersburg 195251 (Russian Federation); Khounsary, A.M., E-mail: amk@iit.edu [Department of Physics, Illinois Institute of Technology, Chicago, IL 60616 (United States); Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL 60607 (United States); Sandy, A.R.; Narayanan, S.; Navrotski, G. [X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2016-06-01

    A cooled double crystal monochromator system is used on many high heat load X-ray synchrotron radiation beamlines in order to select, by diffraction, a narrow spectrum of the beam. Thermal deformation of the first crystal monochromator – and the potential loss of beam brightness – is often a concern. However, if downstream beam focusing is planned, the lensing effect of the monochromator must be considered even if thermal deformations are small. In this paper we report on recent experiments at an Advanced Photon Source (APS) beamline that focuses the X-ray beam using compound refractive lenses downstream of an X-ray monochromator system. Increasing the X-ray beam power by increasing the storage ring current from 100 mA to 130 mA resulted in an effective doubling of the focal distance. We show quantitatively that this is due to a lensing effect of the distorted monochromator that results in the creation of a virtual source downstream of the actual source. An analysis of the defocusing and options to mitigate this effect are explored.

  5. The residual stress instrument with optimized Si(220) monochromator and position-sensitive detector at HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang-Hee [Korea Atomic Energy Research Institute, Yusung, Daejon 305-600 (Korea, Republic of); Moon, Myung-Kook [Korea Atomic Energy Research Institute, Yusung, Daejon 305-600 (Korea, Republic of)]. E-mail: moonmk@kaeri.re.kr; Em, Vyacheslav T. [Korea Atomic Energy Research Institute, Yusung, Daejon 305-600 (Korea, Republic of); Choi, Young-Hyun [Korea Atomic Energy Research Institute, Yusung, Daejon 305-600 (Korea, Republic of); Cheon, Jong-Kyu [Korea Atomic Energy Research Institute, Yusung, Daejon 305-600 (Korea, Republic of); Nam, Uk-Won [Korea Astronomy Observatory, Yusung, Daejon 305-348 (Korea, Republic of); Kong, Kyung-Nam [Korea Astronomy Observatory, Yusung, Daejon 305-348 (Korea, Republic of)

    2005-06-11

    An upgraded residual stress instrument at the HANARO reactor of the KAERI is described. A horizontally focusing bent perfect crystal Si(220) monochromator (instead of a mosaic vertical focusing Ge monochromator) is installed in a drum with a tunable (2{theta}{sub M}=0-60{sup o}) take-off angle/wavelength. A specially designed position-sensitive detector (60% efficiency for {lambda}=1.8A) with 200mm (instead of 100mm) high-active area is used. There are no Soller type collimators in the instrument. The minimum possible monochromator to sample distance, L{sub MS}=2m, and sample to detector distance, L{sub SD}=1.2m, were found to be optimal. The new PSD and bent Si(220) monochromator combined with the possibility of selecting an appropriate wavelength resulted in about a ten-fold gain in data collection rate. The optimal reflections of austenitic and ferritic steels, aluminum and nickel for stress measurements with a Si(220) monochromator were chosen experimentally. The ability of the instrument to make strain measurements deep inside the austenitic and ferritic steels has been tested. For the chosen reflections and wavelengths, no shift of peak position (apparent strain) was observed up to 56mm length of path.

  6. DBS-偶氮胂与钍(Ⅳ)显色反应研究%Studies on the Color Reaction of DBS-Arsenazo and Thorium(Ⅳ)

    Institute of Scientific and Technical Information of China (English)

    胡伟华; 陆训海

    2011-01-01

    钍(Ⅳ)与DBS-偶氮胂在硫酸介质中反应生成组成比为1∶2络合物,由此建立了一个测定钍的新体系.本方法测定钍(Ⅳ)的线性范围为0~2μg·mL-1,在628nm处方法表观摩尔吸光系数为ε=1.02×105L·mol-1·cm-1,检出限为7.6ng·mL-1.本法用于海带和紫菜样品中钍含量的测定,相对标准偏差分别为4.07%、4.74%,回收率分别为101.3%、101.0%.%It is found that in sulfuric acid, medium thorium(Ⅳ) and DBS-ASA react to generate the composition ratio 1:2 complex. Based on this phenomenon, a new system was developed for the determination of thorium. In this method, the linear calibration was 0-2 μg· mL-1 for the determination of thorium.the apparent molar absorptivity is ε = 1.02× 105 L· mol -1 · cm-1. and the detection limit is 7.6 ng· mL-1, respectively and 628nmThe method was applied to determine the content of thorium in the kelp and laver samples. Their relative standard deviations are 4.07% and 4.74%, respectively. Their recoveries are 101.3% and 101.0%, respectively.

  7. A double multilayer monochromator for the B16 Test beamline at the Diamond Light Source

    Science.gov (United States)

    Sawhney, K. J. S.; Dolbnya, I. P.; Scott, S. M.; Tiwari, M. K.; Preece, G. M.; Alcock, S. G.; Malandain, A. W.

    2011-09-01

    The B16 Test beamline at the Diamond Light Source is in user operation. It has been recently upgraded with the addition of a double multilayer monochromator (DMM), which provides further functionality and versatility to the beamline. The multilayer monochromator is equipped with two pairs of multilayer optics (Ni/B4C and Ru/B4C) to cover the wide photon energy range of 2 - 20 keV, with good efficiency. The DMM provides a broad bandpass / high flux operational mode for the beamline and, when used in tandem with the Si (111) double crystal monochromator, it gives a very high higher-order harmonics suppression. The design details of the DMM and the first commissioning results obtained using the DMM are presented.

  8. Performance of a beam-multiplexing diamond crystal monochromator at the Linac Coherent Light Source

    OpenAIRE

    Zhu, Diling; Feng, Yiping; Stoupin, Stanislav; Terentyev, Sergey A.; Lemke, Henrik T.; Fritz, David M.; Chollet, Matthieu; Glownia, J. M.; Alonso-Mori, Roberto; Sikorski, Marcin; Song, Sanghoon; Brandt van Driel, Tim; Williams, Garth J; Messerschmidt, Marc; Boutet, Sébastien

    2014-01-01

    A double-crystal diamond monochromator was recently implemented at the Linac Coherent Light Source. It enables splitting pulses generated by the free electron laser in the hard x-ray regime and thus allows the simultaneous operations of two instruments. Both monochromator crystals are High-Pressure High-Temperature grown type-IIa diamond crystal plates with the (111) orientation. The first crystal has a thickness of ∼100 μm to allow high reflectivity within the Bragg bandwidth and good transm...

  9. Comparison of Color LCD and Medical-grade Monochrome LCD Displays in Diagnostic Radiology

    OpenAIRE

    2007-01-01

    In diagnostic radiology, medical-grade monochrome displays are usually recommended because of their higher luminance. Standard color displays can be used as a less expensive alternative, but have a lower luminance. The aim of the present study was to compare image quality for these two types of displays. Images of a CDRAD contrast-detail phantom were read by four radiologists using a 2-megapixel (MP) color display (143 cd/m2 maximum luminance) as well as 2-MP (295 cd/m2) and 3-MP monochrome d...

  10. A diffracted-beam monochromator for long linear detectors in X-ray diffractometers with Bragg-Brentano parafocusing geometry

    NARCIS (Netherlands)

    Van der Pers, N.M.; Hendrikx, R.W.A.; Delhez, R.; Böttger, A.J.

    2013-01-01

    A new diffracted-beam monochromator has been developed for Bragg-Brentano X-ray diffractometers equipped with a linear detector. The monochromator consists of a cone-shaped graphite highly oriented pyrolytic graphite crystal oriented out of the equatorial plane such that the parafocusing geometry is

  11. Corticomuscular coherence during hand gripping with DBS and medication in PD patients

    DEFF Research Database (Denmark)

    Sridharan, Kousik Sarathy; Højlund, Andreas; Johnsen, Erik Lisbjerg

    (MEG) from six PD patients performing hand gripping during DBS ON and medicated (levodopa, MED ON) conditions and from ten age-matched healthy controls. Participants performed isotonic contractions (hand gripping) with their right hand, and electromyography (EMG) was recorded from the extensor...... digitorum communis muscle with a belly-tendon montage. We calculated the mean-squared coherence between MEG and the rectified EMG signals. For each group and condition, we selected the maximum CMC value in the beta range (13-30 Hz) within the average of an a priori selection of nine left sensorimotor...

  12. Study of DBS-PPy as cathode material for lithium-ion batteries%DBS-PPy作为锂离子电池正极材料的性能研究

    Institute of Scientific and Technical Information of China (English)

    田方华; 刘黎; 杨振华; 王先友; 陈权启

    2011-01-01

    通过化学氧化法合成了掺杂十二烷基苯磺酸阴离子(DBS-)的聚吡咯( PPy).采用FTIR、SEM对其结构及形貌进行了表征,并采用恒流充放电、循环伏安、交流阻抗等电化学测试手段对其用作锂离子电池正极材料时的电化学性能进行了系统研究.探讨了氧化剂三氯化铁的量对其电化学性能的影响.结果表明,当FeCl3/Py摩尔比为0.75时,材料具有最佳的电化学性能.%DBS-Ppy (dodecylbenzene sulfonate-polypyrrole) was chemically synthesized by an oxidative polymerization of pyrrole monomer using ferric chloride as oxidizing agent. The structure and morphology of DBS-Ppy were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The electrochemical performance of DBS-Ppy was studied by galvanostatic cycling tests, cyclic voltammetry (CV) and electrochemical impedance spectra. The effect of the mass of ferric chloride on electrochemical properties was researched. The results show that DBS-Ppy has the best electrochemical performances when n (FeCI3)/n (Py) is 0.75.

  13. Nanoscale mapping of optical band gaps using monochromated electron energy loss spectroscopy

    Science.gov (United States)

    Zhan, W.; Granerød, C. S.; Venkatachalapathy, V.; Johansen, K. M. H.; Jensen, I. J. T.; Kuznetsov, A. Yu; Prytz, Ø.

    2017-03-01

    Using monochromated electron energy loss spectroscopy in a probe-corrected scanning transmission electron microscope we demonstrate band gap mapping in ZnO/ZnCdO thin films with a spatial resolution below 10 nm and spectral precision of 20 meV.

  14. Measurement & Minimization of Mount Induced Strain on Double Crystal Monochromator Crystals

    Science.gov (United States)

    Kelly, J.; Alcock, S. G.

    2013-03-01

    Opto-mechanical mounts can cause significant distortions to monochromator crystals and mirrors if not designed or implemented carefully. A slope measuring profiler, the Diamond-NOM [1], was used to measure the change in tangential slope as a function of crystal clamping configuration and load. A three point mount was found to exhibit the lowest surface distortion (Diamond Light Source.

  15. Comparison of color LCD and medical-grade monochrome LCD displays in diagnostic radiology.

    Science.gov (United States)

    Geijer, Håkan; Geijer, Mats; Forsberg, Lillemor; Kheddache, Susanne; Sund, Patrik

    2007-06-01

    In diagnostic radiology, medical-grade monochrome displays are usually recommended because of their higher luminance. Standard color displays can be used as a less expensive alternative, but have a lower luminance. The aim of the present study was to compare image quality for these two types of displays. Images of a CDRAD contrast-detail phantom were read by four radiologists using a 2-megapixel (MP) color display (143 cd/m(2) maximum luminance) as well as 2-MP (295 cd/m(2)) and 3-MP monochrome displays. Thirty lumbar spine radiographs were also read by four radiologists using the color and the 2-MP monochrome display in a visual grading analysis (VGA). Very small differences were found between the displays when reading the CDRAD images. The VGA scores were -0.28 for the color and -0.25 for the monochrome display (p = 0.24; NS). It thus seems possible to use color displays in diagnostic radiology provided that grayscale adjustment is used.

  16. Locating the STN-DBS electrodes and resolving their subsequent networks using coherent source analysis on EEG.

    Science.gov (United States)

    Muthuraman, M; Paschen, S; Hellriegel, H; Groppa, S; Deuschl, G; Raethjen, J

    2012-01-01

    The deep brain stimulation (DBS) of the subthalamic nucleus (STN) is the most effective surgical therapy for Parkinson's disease (PD). The first aim of the study was to locate the STN-DBS electrode by applying source analysis on EEG. Secondly, to identify tremor related areas which are associated with the STN. The Dynamic imaging of coherent sources (DICS) was used to find the coherent sources in the brain. The capability of the source analysis to detect deep sources like STN in the brain using EEG data was tested with two model dipole simulations. The simulations were concentrated on two aspects, the angle of the dipole orientation and the disturbance of the cortical areas on locating subcortical regions. In all the DBS treated Parkinsonian tremor patients the power spectrum showed a clear peak at the stimulated frequency and followed by there harmonics. The DBS stimulated frequency constituted a network of primary sensory motor cortex, supplementary motor area, prefrontal cortex, diencephalon, cerebellum and brainstem. Thus the STN was located in the region of the diencephalon. The resolved network may give better understanding to the pathophysiology of the effected tremor network in PD patients with STN-DBS.

  17. Self-seeding scheme with gas monochromator for narrow-bandwidth soft X-ray FELs

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-03-15

    Self-seeding schemes, consisting of two undulators with a monochromator in between, aim at reducing the bandwidth of SASE X-ray FELs. We recently proposed to use a new method of monochromatization exploiting a single crystal in Bragg transmission geometry for self-seeding in the hard X-ray range. Here we consider a possible extension of this method to the soft X-ray range using a cell filled with resonantly absorbing gas as monochromator. The transmittance spectrum in the gas exhibits an absorbing resonance with narrow bandwidth. Then, similarly to the hard X-ray case, the temporal waveform of the transmitted radiation pulse is characterized by a long monochromatic wake. In fact, the FEL pulse forces the gas atoms to oscillate in a way consistent with a forward-propagating, monochromatic radiation beam. The radiation power within this wake is much larger than the equivalent shot noise power in the electron bunch. Further on, the monochromatic wake of the radiation pulse is combined with the delayed electron bunch and amplified in the second undulator. The proposed setup is extremely simple, and composed of as few as two simple elements. These are the gas cell, to be filled with noble gas, and a short magnetic chicane. The installation of the magnetic chicane does not perturb the undulator focusing system and does not interfere with the baseline mode of operation. In this paper we assess the features of gas monochromator based on the use of He and Ne.We analyze the processes in the monochromator gas cell and outside it, touching upon the performance of the differential pumping system as well. We study the feasibility of using the proposed self-seeding technique to generate narrow bandwidth soft X-ray radiation in the LCLS-II soft X-ray beam line. We present conceptual design, technical implementation and expected performances of the gas monochromator self-seeding scheme. (orig.)

  18. EEG power asymmetry and functional connectivity as a marker of treatment effectiveness in DBS surgery for depression.

    Science.gov (United States)

    Quraan, Maher A; Protzner, Andrea B; Daskalakis, Zafiris J; Giacobbe, Peter; Tang, Chris W; Kennedy, Sidney H; Lozano, Andres M; McAndrews, Mary P

    2014-04-01

    Recently, deep brain stimulation (DBS) has been evaluated as an experimental therapy for treatment-resistant depression. Although there have been encouraging results in open-label trials, about half of the patients fail to achieve meaningful benefit. Although progress has been made in understanding the neurobiology of MDD, the ability to characterize differences in brain dynamics between those who do and do not benefit from DBS is lacking. In this study, we investigated EEG resting-state data recorded from 12 patients that have undergone DBS surgery. Of those, six patients were classified as responders to DBS, defined as an improvement of 50% or more on the 17-item Hamilton Rating Scale for Depression (HAMD-17). We compared hemispheric frontal theta and parietal alpha power asymmetry and synchronization asymmetry between responders and non-responders. Hemispheric power asymmetry showed statistically significant differences between responders and non-responders with healthy controls showing an asymmetry similar to responders but opposite to non-responders. This asymmetry was characterized by an increase in frontal theta in the right hemisphere relative to the left combined with an increase in parietal alpha in the left hemisphere relative to the right in non-responders compared with responders. Hemispheric mean synchronization asymmetry showed a statistically significant difference between responders and non-responders in the theta band, with healthy controls showing an asymmetry similar to responders but opposite to non-responders. This asymmetry resulted from an increase in frontal synchronization in the right hemisphere relative to the left combined with an increase in parietal synchronization in the left hemisphere relative to the right in non-responders compared with responders. Connectivity diagrams revealed long-range differences in frontal/central-parietal connectivity between the two groups in the theta band. This pattern was observed irrespective of

  19. Prediction of STN-DBS Electrode Implantation Track in Parkinson's Disease by Using Local Field Potentials

    Science.gov (United States)

    Telkes, Ilknur; Jimenez-Shahed, Joohi; Viswanathan, Ashwin; Abosch, Aviva; Ince, Nuri F.

    2016-01-01

    Optimal electrophysiological placement of the DBS electrode may lead to better long term clinical outcomes. Inter-subject anatomical variability and limitations in stereotaxic neuroimaging increase the complexity of physiological mapping performed in the operating room. Microelectrode single unit neuronal recording remains the most common intraoperative mapping technique, but requires significant expertise and is fraught by potential technical difficulties including robust measurement of the signal. In contrast, local field potentials (LFPs), owing to their oscillatory and robust nature and being more correlated with the disease symptoms, can overcome these technical issues. Therefore, we hypothesized that multiple spectral features extracted from microelectrode-recorded LFPs could be used to automate the identification of the optimal track and the STN localization. In this regard, we recorded LFPs from microelectrodes in three tracks from 22 patients during DBS electrode implantation surgery at different depths and aimed to predict the track selected by the neurosurgeon based on the interpretation of single unit recordings. A least mean square (LMS) algorithm was used to de-correlate LFPs in each track, in order to remove common activity between channels and increase their spatial specificity. Subband power in the beta band (11–32 Hz) and high frequency range (200–450 Hz) were extracted from the de-correlated LFP data and used as features. A linear discriminant analysis (LDA) method was applied both for the localization of the dorsal border of STN and the prediction of the optimal track. By fusing the information from these low and high frequency bands, the dorsal border of STN was localized with a root mean square (RMS) error of 1.22 mm. The prediction accuracy for the optimal track was 80%. Individual beta band (11–32 Hz) and the range of high frequency oscillations (200–450 Hz) provided prediction accuracies of 72 and 68% respectively. The best

  20. Design and optimization of the grating monochromator for soft X-ray self-seeding FELs

    Energy Technology Data Exchange (ETDEWEB)

    Serkez, Svitozar

    2015-10-15

    The emergence of Free Electron Lasers (FEL) as a fourth generation of light sources is a breakthrough. FELs operating in the X-ray range (XFEL) allow one to carry out completely new experiments that probably most of the natural sciences would benefit. Self-amplified spontaneous emission (SASE) is the baseline FEL operation mode: the radiation pulse starts as a spontaneous emission from the electron bunch and is being amplified during an FEL process until it reaches saturation. The SASE FEL radiation usually has poor properties in terms of a spectral bandwidth or, on the other side, longitudinal coherence. Self-seeding is a promising approach to narrow the SASE bandwidth of XFELs significantly in order to produce nearly transformlimited pulses. It is achieved by the radiation pulse monochromatization in the middle of an FEL amplification process. Following the successful demonstration of the self-seeding setup in the hard X-ray range at the LCLS, there is a need for a self-seeding extension into the soft X-ray range. Here a numerical method to simulate the soft X-ray self seeding (SXRSS) monochromator performance is presented. It allows one to perform start-to-end self-seeded FEL simulations along with (in our case) GENESIS simulation code. Based on this method, the performance of the LCLS self-seeded operation was simulated showing a good agreement with an experiment. Also the SXRSS monochromator design developed in SLAC was adapted for the SASE3 type undulator beamline at the European XFEL. The optical system was studied using Gaussian beam optics, wave optics propagation method and ray tracing to evaluate the performance of the monochromator itself. Wave optics analysis takes into account the actual beam wavefront of the radiation from the coherent FEL source, third order aberrations and height errors from each optical element. The monochromator design is based on a toroidal VLS grating working at a fixed incidence angle mounting without both entrance and exit

  1. A critical reflection on the technological development of deep brain stimulation (DBS

    Directory of Open Access Journals (Sweden)

    Christian eIneichen

    2014-09-01

    Full Text Available Since the translational research findings of Benabid and colleagues, which partly led to their seminal paper regarding the treatment of mainly tremor-dominant Parkinson patients through thalamic high-frequency-stimulation (HFS in 1987, we still struggle with identifying a satisfactory mechanistic explanation of the underlying principles of Deep Brain Stimulation. Furthermore, the technological advance of DBS devices (electrodes and implantable pulse generators, IPG's has shown a distinct lack of dynamic progression. In light of this we argue that it is time to leave the paleolithic age and enter hellenistic times: the device-manufacturing industry and the medical community together should put more emphasis on advancing the technology rather than resting on their laurels.

  2. A magnetically adsorbed fine adjustment mechanism of the second crystal in a double-crystal monochromator

    Institute of Scientific and Technical Information of China (English)

    CAO Chong-Zhen; GAO Xue-Guan; MA Pei-Sun; WANG Feng-Qin; HE Dong-Qing; HUANG Yu-Ying; LIU Peng

    2005-01-01

    In a fine adjustment mechanism of the second crystal in a double-crystal monochromator, a compression spring is usually used as a return force element, but it often produces permanent deform after some time. A novel fine adjustment mechanism is put forward, which utilizes permanent-magnet as the return force element instead of a compression spring. Its principle and advantages of adjusting the pitch angle and the roll angle are analyzed, and the structure parameters of the permanent-magnet, which is the key pa rt of the fine adjustment mechanism, are optimized. The magnetically adsorbed fine adjustment mechanism has been testified and applied successfully in the double-crystal monochromator of 4W1B beam line in Beijing Synchrotron Radiation Facility (BSRF).

  3. Stress mitigation of x-ray beamline monochromators using topography test unit.

    Energy Technology Data Exchange (ETDEWEB)

    Maj, J.; Waldschmidt, G.; Baldo, P.; Macrander, A.; Koshelev, I.; Huang, R.; Maj, L.; Maj, A.; Univ. of Chicago; Northeastern Ohio Univ. Coll. of Medicine; Rosalind Franklin Univ. of Medicine and Science

    2007-01-01

    Silicon and diamond monochromators (crystals), often used in the Advanced Photon Source X-ray beamlines, require a good quality surface finish and stress-free installation to ensure optimal performance. The device used to mount the crystal has been shown to be ajor contributing source of stress. In this case, an adjustable mounting device is an effective method of reducing stresses and improve the rocking curve to levels much closer to ideal. Analysis by a topography test unit has been used to determine the distribution of stresses and to measure the rocking curve, as well as create CCD images of the crystal. This paper describes the process of measuring these stresses and manipulating the mounting device and crystal to create a substantially improved monochromator.

  4. Alignment and characterization of the two-stage time delay compensating XUV monochromator

    CERN Document Server

    Eckstein, Martin; Kubin, Markus; Yang, Chung-Hsin; Frassetto, Fabio; Poletto, Luca; Vrakking, Marc J J; Kornilov, Oleg

    2016-01-01

    We present the design, implementation and alignment procedure for a two-stage time delay compensating monochromator. The setup spectrally filters the radiation of a high-order harmonic generation source providing wavelength-selected XUV pulses with a bandwidth of 300 to 600~meV in the photon energy range of 3 to 50~eV. XUV pulses as short as $12\\pm3$~fs are demonstrated. Transmission of the 400~nm (3.1~eV) light facilitates precise alignment of the monochromator. This alignment strategy together with the stable mechanical design of the motorized beamline components enables us to automatically scan the XUV photon energ in pump-probe experiments that require XUV beam pointing stability. The performance of the beamline is demonstrated by the generation of IR-assisted sidebands in XUV photoionization of argon atoms.

  5. Grating monochromator for soft X-ray self-seeding the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Serkez, Svitozar; Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany)

    2013-02-15

    Self-seeding is a promising approach to significantly narrow the SASE bandwidth of XFELs to produce nearly transform-limited pulses. The implementation of this method in the soft X-ray wavelength range necessarily involves gratings as dispersive elements. We study a very compact self-seeding scheme with a grating monochromator originally designed at SLAC, which can be straightforwardly installed in the SASE3 type undulator beamline at the European XFEL. The monochromator design is based on a toroidal VLS grating working at a fixed incidence angle mounting without entrance slit. It covers the spectral range from 300 eV to 1000 eV. The optical system was studied using wave optics method (in comparison with ray tracing) to evaluate the performance of the self-seeding scheme. Our wave optics analysis takes into account the actual beam wavefront of the radiation from the coherent FEL source, third order aberrations, and errors from each optical element. Wave optics is the only method available, in combination with FEL simulations, for the design of a self-seeding monochromator without exit slit. We show that, without exit slit, the self-seeding scheme is distinguished by the much needed experimental simplicity, and can practically give the same resolving power (about 7000) as with an exit slit. Wave optics is also naturally applicable to calculations of the self-seeding scheme efficiency, which include the monochromator transmittance and the effect of the mismatching between seed beam and electron beam. Simulations show that the FEL power reaches 1 TW and that the spectral density for a TW pulse is about two orders of magnitude higher than that for the SASE pulse at saturation.

  6. Fast continuous energy scan with dynamic coupling of the monochromator and undulator at the DEIMOS beamline.

    Science.gov (United States)

    Joly, L; Otero, E; Choueikani, F; Marteau, F; Chapuis, L; Ohresser, P

    2014-05-01

    In order to improve the efficiency of X-ray absorption data recording, a fast scan method, the Turboscan, has been developed on the DEIMOS beamline at Synchrotron SOLEIL, consisting of a software-synchronized continuous motion of the monochromator and undulator motors. This process suppresses the time loss when waiting for the motors to reach their target positions, as well as software dead-time, while preserving excellent beam characteristics.

  7. Focusing characteristics of diamond crystal x-ray monochromators. An experimental and theoretical comparison

    DEFF Research Database (Denmark)

    Rio, M.S. del; Grübel, G.; Als-Nielsen, J.

    1995-01-01

    Perfect crystals in transmission (Laue) geometry can be used effectively for x-ray monochromators, and moreover, perfect Laue crystals show an interesting focusing effect when the incident beam is white and divergent. This focusing is directly dependent on the incident beam divergence and on the ...... from a diamond crystal in Lane geometry, and we analyze and explain the results by comparison with ray-tracing simulations. (C) 1995 American Institute of Physics....

  8. Effects of Co-addition of DBS and PEG on Wetting Performance of TiO2 Film

    Institute of Scientific and Technical Information of China (English)

    QU Yi-chun; JING Li-qiang; WANG Wen-xin; FU Hong-gang; LIU Yang

    2011-01-01

    Nanocrystalline anatase TiO2 films with indium tin oxide(ITO) coated glass as the film substrate were fabricated through spin-coating technique. The TiO2 pastes were prepared with sodium dodecylbenzenesulfonate(DBS)modified TiO2 nanocrystals, synthesized by sol-hydrothermal processes in advance, together with different amounts of polyethylene glycol(PEG) macromolecules. The as-prepared films were mainly characterized by ultraviolet-visible (UV-Vis) spectroscopy, field emission scanning electron microscopy(FE-SEM) and water contact angle(WCA) measurement. Effects of the addition of DBS and PEG on the wetting performance of the resulting films and relevant mechanisms were principally investigated. The results show that the as-prepared film displays super-hydrophilic property after co-addition of DBS and PEG although it is not exposed to ultraviolet light prior to the WCA measurement. This appealing result is mainly attributed to the produced micro- and nanometer-scale hierarchical surface structure with uniformly dispersed micro papillae. Each papilla was made up of a great number of TiO2 nanoparticles.The possible formation mechanisms related to the DBS amphiphilic property of the characteristic surface were also suggested. Moreover, the resulting film also exhibits considerable durability in the superhydrophilicity, which is very useful for practical application in self-cleaning, anti-fogging, and bacteria-resistant fields.

  9. Effects of DBS, premotor rTMS, and levodopa on motor function and silent period in advanced Parkinson's disease

    DEFF Research Database (Denmark)

    Bäumer, Tobias; Hidding, Ute; Hamel, Wolfgang

    2009-01-01

    Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a widely used and highly effective treatment for patients with advanced Parkinson's disease (PD). Repetitive TMS (rTMS) applied to motor cortical areas has also been shown to improve symptoms in PD and modulate motor cortical...

  10. 47 CFR 73.756 - System specifications for double-sideband (DBS) modulated emissions in the HF broadcasting service.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false System specifications for double-sideband (DBS) modulated emissions in the HF broadcasting service. 73.756 Section 73.756 Telecommunication FEDERAL... broadcasting service. (a) Channel spacing. The nominal spacing for DSB shall be 10 kHz. However,...

  11. Did my brain implant make me do it? Questions raised by DBS regarding psychological continuity, responsibility for action and mental competence

    NARCIS (Netherlands)

    Klaming, L.; Haselager, W.F.G.

    2011-01-01

    Deep brain stimulation (DBS) is a wellaccepted treatment for movement disorders and is currently explored as a treatment option for various neurological and psychiatric disorders. Several case studies suggest that DBS may, in some patients, influence mental states critical to personality to such an

  12. In search of optimal DBS paradigms to treat epilepsy: bilateral versus unilateral hippocampal stimulation in a rat model for temporal lobe epilepsy

    NARCIS (Netherlands)

    Van Nieuwenhuyse, B.; Raedt, R.; Delbeke, J.; Wadman, W.J.; Boon, P; Vonck, K.

    2015-01-01

    BACKGROUND: In many temporal lobe epilepsy (TLE) patients both hippocampi are seizure onset zones. These patients are unsuitable candidates for epilepsy surgery but may be amenable to hippocampal deep brain stimulation (DBS). The optimal DBS parameters for these patients are unknown. Recent observat

  13. FEA analysis of diamond as IMCA{close_quote}s monochromator crystal

    Energy Technology Data Exchange (ETDEWEB)

    Chrzas, J.; Cimpoes, S.; Ivanov, I.N. [CSRRI, Illinois Institute of Technology, 3301 S. Dearborn Street, Chicago, IL 60616 (United States)

    1996-09-01

    A great deal of effort has been make in recent years in the field of undulator high heat load optics, and currently there are several tractable options [Rev. Sci. Instrum. {bold 69}, 2792 (1994); Nucl. Instrum. Methods A {bold 266}, 517 (1988); Nucl. Instrum. Methods A {bold 239}, 555 (1993)]. Diamond crystals offer some attractive options{endash}water as the coolant, the use of established monochromator mechanisms, simpler monochromator design as compared to the use of liquid nitrogen or gallium. The use of diamond crystals as the optical elements in a double-crystal monochromator for the IMCA-CAT and MR-CAT ID beamlines has been studied. A first crystal mounting scheme using an indium-gallium eutectic as the heat transfer medium developed in collaboration with DND-CAT and M. Hart will be presented. A FEA analysis of the IMCA-CAT ID beamline arrangement using the APS undulator A as the radiaiton source will be presented. {copyright} {ital 1996 American Institute of Physics.}

  14. Optimization of the polyplanar optical display electronics for a monochrome B-52 display

    Energy Technology Data Exchange (ETDEWEB)

    DeSanto, L.

    1998-04-01

    The Polyplanar Optical Display (POD) is a unique display screen which can be used with any projection source. The prototype ten-inch display is two inches thick and has a matte black face which allows for high contrast images. The prototype being developed is a form, fit and functional replacement display for the B-52 aircraft which uses a monochrome ten-inch display. In order to achieve a long lifetime, the new display uses a new 200 mW green solid-state laser (10,000 hr. life) at 532 nm as its light source. To produce real-time video, the laser light is being modulated by a Digital Light Processing (DLP{trademark}) chip manufactured by Texas Instruments (TI). In order to use the solid-state laser as the light source and also fit within the constraints of the B-52 display, the Digital Micromirror Device (DMD{trademark}) chip is operated remotely from the Texas Instruments circuit board. In order to achieve increased brightness a monochrome digitizing interface was investigated. The operation of the DMD{trademark} divorced from the light engine and the interfacing of the DMD{trademark} board with the RS-170 video format specific to the B-52 aircraft will be discussed, including the increased brightness of the monochrome digitizing interface. A brief description of the electronics required to drive the new 200 mW laser is also presented.

  15. Bent Crystal Monochromator with Constant Crystal Center Position and 2-theta Arm for a Dispersive Beamline

    Science.gov (United States)

    Neuenschwander, Regis T.; Tolentino, Hélio C. N.

    2004-05-01

    For the new LNLS dispersive beam line it was designed a single-crystal monochromator and a 2-theta arm. The monochromator uses a new bender design assembled on the top of an in-vacuum HUBER goniometer. This bender is able to apply independent torque on each extremity of the crystal in a way that changes in the curvature radius do not affect the position of the center of the crystal. It also has a twist mechanism, based on eccentric bearings and elastic components. The crystal extremities are clamped to the bender using two water-cooled copper blocks, for thermal stabilization. All the bender's movements are done with vacuum compatible stepping-motors. The vacuum chamber was built with enough space to allow future installation of another bender for crystals with different Bragg planes. The internal mechanics is isolated from the vacuum chamber and can move up and down with three high precision jacks. The design of the 2-theta arm is based on two linear translation stages and some special bearings. The two stages are equipped with linear encoders, ball screws end linear bearings. With a proper alignment procedure, it is possible to find the equations that controls each translation stage in order to get a virtual rotation referenced to the monochromator center. The main arm is composed of a steel frame, a 3m long granite block, a central aluminum optical rail and two auxiliary side rails.

  16. Milli-electronvolt monochromatization of hard X-rays with a sapphire backscattering monochromator

    Science.gov (United States)

    Sergueev, I.; Wille, H.-C.; Hermann, R. P.; Bessas, D.; Shvyd’ko, Yu. V.; Zając, M.; Rüffer, R.

    2011-01-01

    A sapphire backscattering monochromator with 1.1 (1) meV bandwidth for hard X-rays (20–40 keV) is reported. The optical quality of several sapphire crystals has been studied and the best crystal was chosen to work as the monochromator. The small energy bandwidth has been obtained by decreasing the crystal volume impinged upon by the beam and by choosing the crystal part with the best quality. The monochromator was tested at the energies of the nuclear resonances of 121Sb at 37.13 keV, 125Te at 35.49 keV, 119Sn at 23.88 keV, 149Sm at 22.50 keV and 151Eu at 21.54 keV. For each energy, specific reflections with sapphire temperatures in the 150–300 K region were chosen. Applications to nuclear inelastic scattering with these isotopes are demonstrated. PMID:21862862

  17. A bent Laue-Laue monochromator for a synchrotron-based computed tomography system

    CERN Document Server

    Ren, B; Chapman, L D; Ivanov, I; Wu, X Y; Zhong, Z; Huang, X

    1999-01-01

    We designed and tested a two-crystal bent Laue-Laue monochromator for wide, fan-shaped synchrotron X-ray beams for the program multiple energy computed tomography (MECT) at the National Synchrotron Light Source (NSLS). MECT employs monochromatic X-ray beams from the NSLS's X17B superconducting wiggler beamline for computed tomography (CT) with an improved image quality. MECT uses a fixed horizontal fan-shaped beam with the subject's apparatus rotating around a vertical axis. The new monochromator uses two Czochralski-grown Si crystals, 0.7 and 1.4 mm thick, respectively, and with thick ribs on their upper and lower ends. The crystals are bent cylindrically, with the axis of the cylinder parallel to the fan beam, using 4-rod benders with two fixed rods and two movable ones. The bent-crystal feature of the monochromator resolved the difficulties we had had with the flat Laue-Laue design previously used in MECT, which included (a) inadequate beam intensity, (b) excessive fluctuations in beam intensity, and (c) i...

  18. Resolution enhancement in transmission electron microscopy with 60-kV monochromated electron source

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, Shigeyuki; Mukai, Masaki; Sawada, Hidetaka [JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo 196-8558 (Japan); Suenaga, Kazutomo [National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan)

    2016-01-04

    Transmission electron microscopy (TEM) at low accelerating voltages is useful to obtain images with low irradiation damage. For a low accelerating voltage, linear information transfer, which determines the resolution for observation of single-layered materials, is largely limited by defocus spread, which improves when a narrow energy spread is used in the electron source. In this study, we have evaluated the resolution of images obtained at 60 kV by TEM performed with a monochromated electron source. The defocus spread has been evaluated by comparing diffractogram tableaux from TEM images obtained under nonmonochromated and monochromated illumination. The information limits for different energy spreads were precisely measured by using diffractograms with a large beam tilt. The result shows that the information limit reaches 0.1 nm with an energy width of 0.10 eV. With this monochromated source and a higher-order aberration corrector, we have obtained images of single carbon atoms in a graphene sheet by TEM at 60 kV.

  19. High heat flux x-ray monochromators: What are the limits?

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, C.S.

    1997-06-01

    First optical elements at third-generation, hard x-ray synchrotrons, such as the Advanced Photon Source (APS), are subjected to immense heat fluxes. The optical elements include crystal monochromators, multilayers and mirrors. This paper presents a mathematical model of the thermal strain of a three-layer (faceplate, heat exchanger, and baseplate), cylindrical optic subjected to narrow beam of uniform heat flux. This model is used to calculate the strain gradient of a liquid-gallium-cooled x-ray monochromator previously tested on an undulator at the Cornell High Energy Synchrotron Source (CHESS). The resulting thermally broadened rocking curves are calculated and compared to experimental data. The calculated rocking curve widths agree to within a few percent of the measured values over the entire current range tested (0 to 60 mA). The thermal strain gradient under the beam footprint varies linearly with the heat flux and the ratio of the thermal expansion coefficient to the thermal conductivity. The strain gradient is insensitive to the heat exchanger properties and the optic geometry. This formulation provides direct insight into the governing parameters, greatly reduces the analysis time, and provides a measure of the ultimate performance of a given monochromator.

  20. DBS-platform for biomonitoring and toxicokinetics of toxicants: proof of concept using LC-MS/MS analysis of fipronil and its metabolites in blood

    Science.gov (United States)

    Raju, Kanumuri Siva Rama; Taneja, Isha; Rashid, Mamunur; Sonkar, Ashish Kumar; Wahajuddin, Muhammad; Singh, Sheelendra Pratap

    2016-03-01

    A simple, sensitive and high throughput LC-MS/MS method was developed and validated for quantification of fipronil, fipronil sulfone and fipronil desulfinyl in rat and human dried blood spots (DBS). DBS samples were prepared by spiking 10 μl blood on DMPK-C cards followed by drying at room temperature. The whole blood spots were then punched from the card and extracted using acetonitrile. The total chromatographic run time of the method was only 2 min. The lower limit of quantification of the method was 0.1 ng/ml for all the analytes. The method was successfully applied to determine fipronil desulfinyl in DBS samples obtained from its toxicokinetic study in rats following intravenous dose (1 mg/kg). In conclusion, the proposed DBS methodology has significant potential in toxicokinetics and biomonitoring studies of environmental toxicants. This microvolume DBS technique will be an ideal tool for biomonitoring studies, particularly in paediatric population. Small volume requirements, minimally invasive blood sampling method, easier storage and shipping procedure make DBS a suitable technique for such studies. Further, DBS technique contributes towards the principles of 3Rs resulting in significant reduction in the number of rodents used and refinement in sample collection for toxicokinetic studies.

  1. Translation and cross-cultural adaptation of the Brazilian Portuguese version of the Driving Behavior Survey (DBS

    Directory of Open Access Journals (Sweden)

    Jessye Almeida Cantini

    2013-12-01

    Full Text Available BACKGROUND: Fear of driving has been recognized as a complex diagnostic entity. For this reason, the use of psychometric instruments is fundamental to advancing research in this area. Psychometric instruments are also necessary for clinical care, as they can help conceptualize the disorder and plan adequate treatment. OBJECTIVE: To describe the cross-cultural adaptation of a Brazilian version of the Driving Behavior Survey (DBS. Methods: The process consisted of: 1 two translations and back-translations carried out by independent evaluators; 2 development of a brief version by four bilingual experts in mental health; 3 experimental application; and 4 investigation of operational equivalence. RESULTS: The adaptation process is described and a final Brazilian version of the DBS is presented. CONCLUSION: A new instrument is now available to assess the driving behaviors of the Brazilian population, facilitating research in this field.

  2. Does suppression of oscillatory synchronisation mediate some of the therapeutic effects of DBS in patients with Parkinson’s disease?

    Directory of Open Access Journals (Sweden)

    Alexandre eEusebio

    2012-07-01

    Full Text Available There is growing evidence for exaggerated oscillatory neuronal synchronisation in patients with Parkinson’s disease. In particular, oscillations at around 20 Hz, in the so-called beta frequency band, relate to the cardinal symptoms of bradykinesia and rigidity. Deep brain stimulation of the subthalamic nucleus can significantly improve these motor impairments. Recent evidence has demonstrated reduction of beta oscillations concurrent with alleviation of PD motor symptoms, raising the possibility that suppression of aberrant activity may mediate the effects of DBS. Here we review the evidence supporting suppression of pathological oscillations during stimulation and discuss how this might underlie the efficacy of DBS. We also consider how beta activity may provide a feedback signal suitable for next generation closed loop and intelligent stimulators.

  3. The embedded clusters DBS 77, 78, 102, and 160-161 and their link with the interstellar medium

    CERN Document Server

    Corti, M A; Panei, J A; Suad, L A; Testori, J C; Borissova, J; Kurtev, R; Chené, A N; Alegría, S Ramirez

    2016-01-01

    Aims. We report a study of the global properties of some embedded clusters placed in the fourth quadrant of the Milky Way to clarify some issues related with their location into the Galaxy and their stellar formation processes. Methods. We performed BVI photometric observations in the region of DBS 77, 78, 102, 160, and 161 clusters and infrared spectroscopy in DBS 77 region. They were complemented with JHK data from VVV survey combined with 2MASS catalogue, and used mid-infrared information from GLIMPSE catalogue. We also searched for HI data from SGPS and PMN radio surveys, and previous spectroscopic stellar classification. The spectroscopic and photometric information allowed us to estimate the spectral classification of the brightest stars of each studied region. On the other hand, we used the radio data to investigate the interstellar material parameters and the continuum sources probably associated with the respective stellar components. Results. We estimated the basic physical parameters of the cluster...

  4. Study of a scattering shield in a high heat load monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Rong, E-mail: rh66@cornell.edu [IMCA-CAT, Hauptman-Woodward Institute (United States); Meron, Mati [CARS, The University of Chicago (United States)

    2013-07-11

    The techniques for the cooling of the first crystal of a monochromator are by now mature and are used routinely to deal with the heat loads resulting from the intense beams generated by third generation synchrotron insertion device sources. However, the thermal stability of said monochromators, which crucially depends on proper shielding of X-ray scattering off the first crystal, remains a serious consideration. This will become even more so in the near future, as many synchrotron facilities are upgrading to higher beam currents and energies. During a recent upgrade of the 17-ID beamline at the APS it was recognized that accurate simulation of the spatial distribution of the power scattered off the first crystal was essential for the understanding and remediation of the observed large temperature increase of the first crystal's scattering shield. The calculation is complex, due to the broad energy spectrum of the undulator and the prevalence of multiple X-ray scattering events within the bulk of the crystal, thus the Monte Carlo method is the natural tool for such a task. A successful simulation was developed, for the purpose of the 17-ID upgrade, and used to significantly improve the design of the first crystal's scattering shield. -- Highlights: • We use the Monte Carlo method to simulate X-ray scattering from monochromator crystals. • Scattered X-ray power on each surface of the scattering shield has been calculated. • Overheating on the original shield is well explained with simulated scattering power. • The thermal stability of the modified scattering shield is satisfactory.

  5. 1-40-keV fixed-exit monochromator for a wafer mapping TXRF facility

    Science.gov (United States)

    Comin, Fabio; Apostolo, G.; Freund, Andreas K.; Mangiagalli, P.; Navizet, M.; Troxel, C. L.

    1998-12-01

    An industrial facility for the mapping of trace impurities on the surface of 300 mm Silicon wafers will be commissioned at the end of 1998. The elements to be detected range from Na to Hg with a target routine detection limit of 108 atoms/cm2. The monochromator of the facility plays a central role and fulfills the following requirements: ease of operations and fast tuning (one single motor); extended energy range (1 - 40 KeV covered by a fixed exit Si(111) channel cut and multilayer pair); smooth and reliable running (water cooling even in the powerful ESRF undulator beams at high energies). The mechanical structure of the monochromator is based on well-established concepts: an external goniometer transfers the main rotation to the in-vacuum plateau via a hollow differentially pumped feed-through. The optical arrangement shows some novelties: the plateau can be cooled either by water or liquid nitrogen and it holds the convex- concave machined Si(111) channel-cut for fixed exit performances. The shape of the machined surfaces of the crystal helps also on to spread the power density of the beam on the silicon surface. A set of two identical multilayers are also mounted on the plateau and the transition from the Si(111) crystal to the multilayer operation is performed by rotating the wafer main axis by about 180 degrees. The whole facility is centered around the three main components: the monochromator, the wafer handling robots and the two linear arrays of solid state fluorescence detectors.

  6. Comparison of the commercial color LCD and the medical monochrome LCD using randomized object test patterns.

    Directory of Open Access Journals (Sweden)

    Jay Wu

    Full Text Available Workstations and electronic display devices in a picture archiving and communication system (PACS provide a convenient and efficient platform for medical diagnosis. The performance of display devices has to be verified to ensure that image quality is not degraded. In this study, we designed a set of randomized object test patterns (ROTPs consisting of randomly located spheres with various image characteristics to evaluate the performance of a 2.5 mega-pixel (MP commercial color LCD and a 3 MP diagnostic monochrome LCD in several aspects, including the contrast, resolution, point spread effect, and noise. The ROTPs were then merged into 120 abdominal CT images. Five radiologists were invited to review the CT images, and receiver operating characteristic (ROC analysis was carried out using a five-point rating scale. In the high background patterns of ROTPs, the sensitivity performance was comparable between both monitors in terms of contrast and resolution, whereas, in the low background patterns, the performance of the commercial color LCD was significantly poorer than that of the diagnostic monochrome LCD in all aspects. The average area under the ROC curve (AUC for reviewing abdominal CT images was 0.717±0.0200 and 0.740±0.0195 for the color monitor and the diagnostic monitor, respectively. The observation time (OT was 145±27.6 min and 127±19.3 min, respectively. No significant differences appeared in AUC (p = 0.265 and OT (p = 0.07. The overall results indicate that ROTPs can be implemented as a quality control tool to evaluate the intrinsic characteristics of display devices. Although there is still a gap in technology between different types of LCDs, commercial color LCDs could replace diagnostic monochrome LCDs as a platform for reviewing abdominal CT images after monitor calibration.

  7. Comparison of the commercial color LCD and the medical monochrome LCD using randomized object test patterns.

    Science.gov (United States)

    Wu, Jay; Wu, Tung H; Han, Rou P; Chang, Shu J; Shih, Cheng T; Sun, Jing Y; Hsu, Shih M

    2012-01-01

    Workstations and electronic display devices in a picture archiving and communication system (PACS) provide a convenient and efficient platform for medical diagnosis. The performance of display devices has to be verified to ensure that image quality is not degraded. In this study, we designed a set of randomized object test patterns (ROTPs) consisting of randomly located spheres with various image characteristics to evaluate the performance of a 2.5 mega-pixel (MP) commercial color LCD and a 3 MP diagnostic monochrome LCD in several aspects, including the contrast, resolution, point spread effect, and noise. The ROTPs were then merged into 120 abdominal CT images. Five radiologists were invited to review the CT images, and receiver operating characteristic (ROC) analysis was carried out using a five-point rating scale. In the high background patterns of ROTPs, the sensitivity performance was comparable between both monitors in terms of contrast and resolution, whereas, in the low background patterns, the performance of the commercial color LCD was significantly poorer than that of the diagnostic monochrome LCD in all aspects. The average area under the ROC curve (AUC) for reviewing abdominal CT images was 0.717±0.0200 and 0.740±0.0195 for the color monitor and the diagnostic monitor, respectively. The observation time (OT) was 145±27.6 min and 127±19.3 min, respectively. No significant differences appeared in AUC (p = 0.265) and OT (p = 0.07). The overall results indicate that ROTPs can be implemented as a quality control tool to evaluate the intrinsic characteristics of display devices. Although there is still a gap in technology between different types of LCDs, commercial color LCDs could replace diagnostic monochrome LCDs as a platform for reviewing abdominal CT images after monitor calibration.

  8. A New Flexible Monochromator Setup for Quick Scanning X-ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Stotzel, J.; Lutzenkirchen-Hecht, D; Frahm, R

    2010-01-01

    A new monochromator setup for quick scanning x-ray absorption spectroscopy in the subsecond time regime is presented. Novel driving mechanics allow changing the energy range of the acquired spectra by remote control during data acquisition for the first time, thus dramatically increasing the flexibility and convenience of this method. Completely new experiments are feasible due to the fact that time resolution, edge energy, and energy range of the acquired spectra can be changed continuously within seconds without breaking the vacuum of the monochromator vessel and even without interrupting the measurements. The advanced mechanics are explained in detail and the performance is characterized with x-ray absorption spectra of pure metal foils. The energy scale was determined by a fast and accurate angular encoder system measuring the Bragg angle of the monochromator crystal with subarcsecond resolution. The Bragg angle range covered by the oscillating crystal can currently be changed from 0{sup o} to 3.0{sup o} within 20 s, while the mechanics are capable to move with frequencies of up to ca. 35 Hz, leading to ca. 14 ms/spectrum time resolution. A new software package allows performing programmed scan sequences, which enable the user to measure stepwise with alternating parameters in predefined time segments. Thus, e.g., switching between edges scanned with the same energy range is possible within one in situ experiment, while also the time resolution can be varied simultaneously. This progress makes the new system extremely user friendly and efficient to use for time resolved x-ray absorption spectroscopy at synchrotron radiation beamlines.

  9. A new flexible monochromator setup for quick scanning x-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Stoetzel, J.; Luetzenkirchen-Hecht, D.; Frahm, R. [Fachbereich C, Physik, Bergische Universitaet Wuppertal, Gaussstr. 20, 42097 Wuppertal (Germany)

    2010-07-15

    A new monochromator setup for quick scanning x-ray absorption spectroscopy in the subsecond time regime is presented. Novel driving mechanics allow changing the energy range of the acquired spectra by remote control during data acquisition for the first time, thus dramatically increasing the flexibility and convenience of this method. Completely new experiments are feasible due to the fact that time resolution, edge energy, and energy range of the acquired spectra can be changed continuously within seconds without breaking the vacuum of the monochromator vessel and even without interrupting the measurements. The advanced mechanics are explained in detail and the performance is characterized with x-ray absorption spectra of pure metal foils. The energy scale was determined by a fast and accurate angular encoder system measuring the Bragg angle of the monochromator crystal with subarcsecond resolution. The Bragg angle range covered by the oscillating crystal can currently be changed from 0 deg. to 3.0 deg. within 20 s, while the mechanics are capable to move with frequencies of up to ca. 35 Hz, leading to ca. 14 ms/spectrum time resolution. A new software package allows performing programmed scan sequences, which enable the user to measure stepwise with alternating parameters in predefined time segments. Thus, e.g., switching between edges scanned with the same energy range is possible within one in situ experiment, while also the time resolution can be varied simultaneously. This progress makes the new system extremely user friendly and efficient to use for time resolved x-ray absorption spectroscopy at synchrotron radiation beamlines.

  10. 一种简单的六色打印数字半调算法%A Simple Digital Halftone Algorithm for Six Color Inkjet Printer

    Institute of Scientific and Technical Information of China (English)

    田玉敏; 吴自力; 柯丽芳

    2004-01-01

    Traditional ink-jet printer with CMYK inks has limited color gamut. To improve the quality of printing images, many plotters added two inter-grade colors Lc and Lm, which makes it more color-levels achieved.The color images printed with six-color printer have less artificial textures produced by halftone. The advantages of six-color printing are introduced. A new pattern and halftone algorithm for six-color printer is presented. Research has proved that the algorithm is simple and practical.%传统的喷墨打印机通常采用四色墨水(CMYK)打印,但CMYK四色墨水所能提供的色彩有限,为进一步提高彩色图像的输出质量,目前很多新型打印机在原有CMYK墨水的基础上增加了浅品红(Lm)和浅青墨水(Lc),从而使打印机可实现的色阶更加丰富.使用六色墨水打印不仅提高了输出图像的分辨率和清晰度,增强了图像细节,而且还使图像的色调过渡更平滑,降低了半调技术产生的图样干扰,极大地提高了打印图像质量.简单介绍了六色打印的优点,提出了一种适用六色打印的模板和误差分散数字半调算法,实验表明,该算法简单实用.

  11. The pedunculopontine tegmental nucleus: from basic neuroscience to neurosurgical applications: Arousal from slices to humans: implications for DBS

    OpenAIRE

    Garcia-Rill, Edgar; Simon, Christen; Smith, Kristen; Kezunovic, Nebosja; Hyde, James

    2010-01-01

    One element of the reticular activating system (RAS) is the pedunculopontine nucleus (PPN), which projects to the thalamus to trigger thalamocortical rhythms and the brainstem to modulate muscle tone and locomotion. The PPN is a posterior midbrain site known to induce locomotion in decerebrate animals when activated at 40–60 Hz, and has become a target for DBS in disorders involving gait deficits. We developed a research program using brainstem slices containing the PPN to study the cellular ...

  12. SYNTHESIS AND INTERFACIAL STRUCTURE OF NANOPARTICLESγ-Fe2O3 COATED WITH SURFACTANT DBS AND CTAB

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The γ-Fe2O3 nanoparticles coated with DBS and CTAB were prepared by the microemulsion method.The coated samples show enhanced nonlinear optical properties compared with their bulk couterpart.The.Moessbauer spectra at room temperature were measured for the coated ferric oxides.The monolayers of the organic molecule are found to have a strong chemical bond with the surface atoms and thus have a significant influence on the electron structure of particle surface.@ 1999 Acta Metallurgica Inc.

  13. A crystallographic view of interactions between Dbs and Cdc42: PH domain-assisted guanine nucleotide exchange

    OpenAIRE

    Rossman, Kent L.; Worthylake, David K.; Snyder, Jason T; Siderovski, David P.; Campbell, Sharon L; Sondek, John

    2002-01-01

    Dbl-related oncoproteins are guanine nucleotide exchange factors (GEFs) specific for Rho guanosine triphosphatases (GTPases) and invariably possess tandem Dbl (DH) and pleckstrin homology (PH) domains. While it is known that the DH domain is the principal catalytic subunit, recent biochemical data indicate that for some Dbl-family proteins, such as Dbs and Trio, PH domains may cooperate with their associated DH domains in promoting guanine nucleotide exchange of Rho GTPases. In order to gain ...

  14. A new gradient monochromator for the IN13 back-scattering spectrometer

    Science.gov (United States)

    Ciampolini, L.; Bove, L. E.; Mondelli, C.; Alianelli, L.; Labbe-Lavigne, S.; Natali, F.; Bée, M.; Deriu, A.

    2005-06-01

    We present new McStas simulations of the back-scattering thermal neutron spectrometer IN13 to evaluate the advantages of a new temperature gradient monochromator relative to a conventional one. The simulations show that a flux gain up to a factor 7 can be obtained with just a 10% loss in energy resolution and a 20% increase in beam spot size at the sample. The results also indicate that a moderate applied temperature gradient (ΔT≃16 K) is sufficient to obtain this significant flux gain.

  15. A new gradient monochromator for the IN13 back-scattering spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Ciampolini, L. [Istituto Nazionale per la Fisica della Materia, Unita di Parma (Italy)]. E-mail: ciampolinil@ieee.org; Bove, L.E. [Istituto Nazionale per la Fisica della Materia, OGG, ILL Grenoble (France); Mondelli, C. [Istituto Nazionale per la Fisica della Materia, OGG, ILL Grenoble (France); Alianelli, L. [Istituto Nazionale per la Fisica della Materia, OGG, ILL Grenoble (France); Institut Laue Langevin, Grenoble (France); Labbe-Lavigne, S. [CNRS, Grenoble (France); Natali, F. [Istituto Nazionale per la Fisica della Materia, OGG, ILL Grenoble (France); Bee, M. [Universite Joseph Fourier, Grenoble (France); Deriu, A. [Istituto Nazionale per la Fisica della Materia, Unita di Parma (Italy); Dipartimento di Fisica, Universita di Parma (Italy)

    2005-06-01

    We present new McStas simulations of the back-scattering thermal neutron spectrometer IN13 to evaluate the advantages of a new temperature gradient monochromator relative to a conventional one. The simulations show that a flux gain up to a factor 7 can be obtained with just a 10% loss in energy resolution and a 20% increase in beam spot size at the sample. The results also indicate that a moderate applied temperature gradient ({delta}T{approx}16K) is sufficient to obtain this significant flux gain. n.

  16. Synchronous scanning of undulator gap and monochromator for XAFS measurements in soft x-ray region.

    Science.gov (United States)

    Tanaka, T; Matsubayashi, N; Imamura, M; Shimada, H

    2001-03-01

    Synchronous scanning of the undulator gap and a monochromator was done to obtain smooth profiles of incident x-rays that are suitable for XAFS measurements. By changing the gap from 150 mm(B=0.12 T) to 140 mm (B=0.15 T) with the use of the 3rd to 11th harmonic peaks, soft x-rays with energy from 200 eV to 1200 eV were obtained. The smooth profile of the incident x-rays provided high-quality measurement of XANES and EXAFS spectra in the soft x-ray region. Issues that would improve the synchronous scanning system are discussed.

  17. Ultra high energy resolution focusing monochromator for inelastic X-ray scattering spectrometer

    CERN Document Server

    Suvorov, A; Chubar, O; Cai, Y Q

    2015-01-01

    A further development of a focusing monochromator concept for X-ray energy resolution of 0.1 meV and below is presented. Theoretical analysis of several optical layouts based on this concept was supported by numerical simulations performed in the "Synchrotron Radiation Workshop" software package using the physical-optics approach and careful modeling of partially-coherent synchrotron (undulator) radiation. Along with the energy resolution, the spectral shape of the energy resolution function was investigated. It was shown that under certain conditions the decay of the resolution function tails can be faster than that of the Gaussian function.

  18. A soft X-ray plane-grating monochromator optimized for elliptical dipole radiation from modern sources

    Energy Technology Data Exchange (ETDEWEB)

    Kachel, Torsten, E-mail: torsten.kachel@helmholtz-berlin.de; Eggenstein, Frank [Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Follath, Rolf [Paul Scherrer Institute, 5232 Villigen (Switzerland)

    2015-07-14

    The utilization of elliptical dipole radiation in a collimated plane-grating monochromator at BESSY II is described. A new but yet well proven way of making elliptically polarized dipole radiation from the BESSY II storage ring applicable to the SX700-type collimated plane-grating monochromator PM3 is described. It is shown that due to the limited vertical acceptance of the grating a simple use of vertical apertures is not possible in this case. Rather, deflecting the beam upwards or downwards by rotating the vertically collimating toroidal mirror M1 around the light axis leads to excellent performance. The resulting detuning of the photon energy can be taken into account by a readjustment of the monochromator internal plane mirror M2. The energy resolution of the beamline is not affected by the non-zero ‘roll’ of the collimating mirror.

  19. Optimisation and fabrication of a composite pyrolytic graphite monochromator for the Pelican instrument at the ANSTO OPAL reactor

    Science.gov (United States)

    Freund, A. K.; Yu, D. H.

    2011-04-01

    The triple monochromator for the TOF neutron spectrometer Pelican at ANSTO has been fully optimised in terms of overall performance, including the determination of the thickness of the pyrolytic graphite crystals. A total of 24 composite crystals were designed and fabricated. The calculated optimum thickness of 1.3 mm and the length of 15 cm of the monochromator crystals, that are not available commercially, were obtained by cleaving and soldering with indium. An extensive characterisation of the crystals using X-ray and neutron diffraction was conducted before and after the cleaving and bonding processes. The results proved that no damage was introduced during fabrication and showed that the design goals were fully met. The measured peak reflectivity and rocking curve widths were indeed in an excellent agreement with theory. In addition to the superior efficiency of the triple monochromator achieved by this novel approach, the amount of the crystal material required could be reduced by 1/3.

  20. Self-seeding scheme with gas monochromator for narrow-bandwidth soft X-ray FELs

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2011-01-01

    Self-seeding schemes, consisting of two undulators with a monochromator in between, aim at reducing the bandwidth of SASE X-ray FELs. We recently proposed to use a new method of monochromatization exploiting a single crystal in Bragg-transmission geometry for self-seeding in the hard X-ray range. Here we consider a possible extension of this method to the soft X-ray range using a cell filled with resonantly absorbing gas as monochromator. The transmittance spectrum in the gas exhibits an absorbing resonance with narrow bandwidth. Then, similarly to the hard X-ray case, the temporal waveform of the transmitted radiation pulse is characterized by a long monochromatic wake. In fact, the FEL pulse forces the gas atoms to oscillate in a way consistent with a forward-propagating, monochromatic radiation beam. The radiation power within this wake is much larger than the equivalent shot noise power in the electron bunch. Further on, the monochromatic wake of the radiation pulse is combined with the delayed electron b...

  1. $YB_{66} a new soft X-ray monochromator for synchrotron radiation

    CERN Document Server

    Wong, J; Rowen, M; Schäfers, F; Müller, B R; Rek, Z U

    1999-01-01

    For pt.I see Nucl. Instrum. Methods Phys. Res., vol.A291, p.243-8, 1990. YB/sub 66/, a complex boron-rich man-made crystal, has been singled out as a potential monochromator material to disperse synchrotron soft X-rays in the 1-2 keV region. Results of a series of systematic property characterizations pertinent for this application are presented in this paper. These include Laue diffraction patterns and high-precision lattice-constant determination, etch rate, stoichiometry, thermal expansion, soft X-ray reflectivity and rocking-curve measurements, thermal load effects on monochromator performance, nature of intrinsic positive glitches and their reduction. The 004 reflection of YB/sub 66/ has a reflectance of ~3 in this spectral region. The width of the rocking curve varies from 0.25 eV at 1.1 keV to 1.0 eV at 2 keV, which is a factor of two better than that of beryl(1010) in the same energy range, and enables measurements of high-resolution XANES spectra at the Mg, Al and Si K- edges. The thermal bump on the...

  2. An independent survey of monochrome and color low light level TV cameras

    Science.gov (United States)

    Preece, Bradley L.; Tomkinson, David M.; Reynolds, Joseph P.

    2015-05-01

    Using the latest models from the U.S. Army Night Vision Electronic Sensors Directorate (NVESD), a survey of monochrome and color imaging systems at daylight and low light levels is conducted. Each camera system is evaluated and compared under several different assumptions, such as equivalent field of view with equal and variable f/#, common lens focal length and aperture, with high dynamic range comparisons and over several light levels. The modeling is done by use of the Targeting Task Performance (TTP) metric using the latest version of the Night Vision Integrated Performance Model (NV⁸IPM). The comparison is performed over the V parameter, the main output of the TTP metric. Probability of identification (PID) versus range predictions are a direct non-linear mapping of the V parameter as a function of range. Finally, a comparison between the performance of a Bayer-filtered color camera, the Bayer-filtered color camera with the IR block filter removed, and a monochrome version of the same camera is also conducted.

  3. Grating monochromator for soft X-ray self-seeding the European XFEL

    CERN Document Server

    Serkez, Svitozar; Kocharyan, Vitali; Saldin, Evgeni

    2013-01-01

    Self-seeding is a promising approach to significantly narrow the SASE bandwidth of XFELs to produce nearly transform-limited pulses. The implementation of this method in the soft X-ray wavelength range necessarily involves gratings as dispersive elements. We study a very compact self-seeding scheme with a grating monochromator originally designed at SLAC, which can be straightforwardly installed in the SASE3 type undulator beamline at the European XFEL. The monochromator design is based on a toroidal VLS grating working at a fixed incidence angle mounting without entrance slit. It covers the spectral range from 300 eV to 1000 eV. The optical system was studied using wave optics method (in comparison with ray tracing) to evaluate the performance of the self-seeding scheme. Our wave optics analysis takes into account the actual beam wavefront of the radiation from the coherent FEL source, third order aberrations, and errors from each optical element. Wave optics is the only method available, in combination with...

  4. Vibration measurements of high-heat-load monochromators for DESY PETRA III extension

    Energy Technology Data Exchange (ETDEWEB)

    Kristiansen, Paw, E-mail: paw.kristiansen@fmb-oxford.com [FMB Oxford Ltd, Unit 1 Ferry Mills, Oxford OX2 0ES (United Kingdom); Horbach, Jan; Döhrmann, Ralph; Heuer, Joachim [DESY, Deutsches Elektronen-Synchrotron Hamburg, Notkestrasse 85, 22607 Hamburg (Germany)

    2015-05-09

    Vibration measurements of a cryocooled double-crystal monochromator are presented. The origins of the vibrations are identified. The minimum achieved vibration of the relative pitch between the two crystals is 48 nrad RMS and the minimum achieved absolute vibration of the second crystal is 82 nrad RMS. The requirement for vibrational stability of beamline optics continues to evolve rapidly to comply with the demands created by the improved brilliance of the third-generation low-emittance storage rings around the world. The challenge is to quantify the performance of the instrument before it is installed at the beamline. In this article, measurement techniques are presented that directly and accurately measure (i) the relative vibration between the two crystals of a double-crystal monochromator (DCM) and (ii) the absolute vibration of the second-crystal cage of a DCM. Excluding a synchrotron beam, the measurements are conducted under in situ conditions, connected to a liquid-nitrogen cryocooler. The investigated DCM utilizes a direct-drive (no gearing) goniometer for the Bragg rotation. The main causes of the DCM vibration are found to be the servoing of the direct-drive goniometer and the flexibility in the crystal cage motion stages. It is found that the investigated DCM can offer relative pitch vibration down to 48 nrad RMS (capacitive sensors, 0–5 kHz bandwidth) and absolute pitch vibration down to 82 nrad RMS (laser interferometer, 0–50 kHz bandwidth), with the Bragg axis brake engaged.

  5. Italian panoramic monochromator for the THEMIS telescope: the first results and instrument evaluation

    Science.gov (United States)

    Cavallini, Fabio; Berrilli, Francesco; Caccin, Bruno; Cantarano, Sergio; Ceppatelli, Guido; Egidi, Alberto; Righini, Alberto

    1998-07-01

    We briefly describe the design and the characteristics of the Italian Panoramic Monochromator installed at the focal plane of the THEMIS telescope built in Izana by a joint venture of the French and Italian National Research Councils. The Panoramic Monochromator substantially is a narrow band filter (approximately equals 22 mAngstrom bandwidth) tunable on the visible spectrum for quasi simultaneous bidimensional spectrometry of the solar atmosphere. The narrow bandwidth is obtained by using a non standard birefringent filter and a Fabry Perot interferometer mounted in series. This assembly has the advantage of the spectral purity of one channel of the Fabry Perot interferometer and a very large free spectral range. Moreover the spectral stability depends on the interferometer, the environment of which may be carefully controlled. The design of this instrument is not really new, but, only now it has been possible to build it thanks to the development of servo controlled Fabry Perot interferometers, which are stable in time and may easily be tuned. The system seems to perform well. It is stable in wavelength and the spectral pass band and stray light are within the expected values, as it may be deduced by very preliminary tests performed at the THEMIS Telescope and in Arcetri (Firenze) at the 'G. B. Donati' solar tower.

  6. Design and fabrication of an active polynomial grating for soft-X-ray monochromators and spectrometers

    CERN Document Server

    Chen, S J; Perng, S Y; Kuan, C K; Tseng, T C; Wang, D J

    2001-01-01

    An active polynomial grating has been designed for use in synchrotron radiation soft-X-ray monochromators and spectrometers. The grating can be dynamically adjusted to obtain the third-order-polynomial surface needed to eliminate the defocus and coma aberrations at any photon energy. Ray-tracing results confirm that a monochromator or spectrometer based on this active grating has nearly no aberration limit to the overall spectral resolution in the entire soft-X-ray region. The grating substrate is made of a precisely milled 17-4 PH stainless steel parallel plate, which is joined to a flexure-hinge bender shaped by wire electrical discharge machining. The substrate is grounded into a concave cylindrical shape with a nominal radius and then polished to achieve a roughness of 0.45 nm and a slope error of 1.2 mu rad rms. The long trace profiler measurements show that the active grating can reach the desired third-order polynomial with a high degree of figure accuracy.

  7. Design and fabrication of an active polynomial grating for soft-X-ray monochromators and spectrometers

    Science.gov (United States)

    Chen, S.-J.; Chen, C. T.; Perng, S. Y.; Kuan, C. K.; Tseng, T. C.; Wang, D. J.

    2001-07-01

    An active polynomial grating has been designed for use in synchrotron radiation soft-X-ray monochromators and spectrometers. The grating can be dynamically adjusted to obtain the third-order-polynomial surface needed to eliminate the defocus and coma aberrations at any photon energy. Ray-tracing results confirm that a monochromator or spectrometer based on this active grating has nearly no aberration limit to the overall spectral resolution in the entire soft-X-ray region. The grating substrate is made of a precisely milled 17-4 PH stainless steel parallel plate, which is joined to a flexure-hinge bender shaped by wire electrical discharge machining. The substrate is grounded into a concave cylindrical shape with a nominal radius and then polished to achieve a roughness of 0.45 nm and a slope error of 1.2 μrad rms. The long trace profiler measurements show that the active grating can reach the desired third-order polynomial with a high degree of figure accuracy.

  8. High-resolution monochromator for iron nuclear resonance vibrational spectroscopy of biological samples

    Science.gov (United States)

    Yoda, Yoshitaka; Okada, Kyoko; Wang, Hongxin; Cramer, Stephen P.; Seto, Makoto

    2016-12-01

    A new high-resolution monochromator for 14.4-keV X-rays has been designed and developed for the Fe nuclear resonance vibrational spectroscopy of biological samples. In addition to high resolution, higher flux and stability are especially important for measuring biological samples, because of the very weak signals produced due to the low concentrations of Fe-57. A 24% increase in flux while maintaining a high resolution better than 0.9 meV is achieved in the calculation by adopting an asymmetric reflection of Ge, which is used as the first crystal of the three-bounce high-resolution monochromator. A 20% increase of the exit beam size is acceptable to our biological applications. The higher throughput of the new design has been experimentally verified. A fine rotation mechanics that combines a weak-link hinge with a piezoelectric actuator was used for controlling the photon energy of the monochromatic beam. The resulting stability is sufficient to preserve the intrinsic resolution.

  9. A coded structured light system based on primary color stripe projection and monochrome imaging.

    Science.gov (United States)

    Barone, Sandro; Paoli, Alessandro; Razionale, Armando Viviano

    2013-10-14

    Coded Structured Light techniques represent one of the most attractive research areas within the field of optical metrology. The coding procedures are typically based on projecting either a single pattern or a temporal sequence of patterns to provide 3D surface data. In this context, multi-slit or stripe colored patterns may be used with the aim of reducing the number of projected images. However, color imaging sensors require the use of calibration procedures to address crosstalk effects between different channels and to reduce the chromatic aberrations. In this paper, a Coded Structured Light system has been developed by integrating a color stripe projector and a monochrome camera. A discrete coding method, which combines spatial and temporal information, is generated by sequentially projecting and acquiring a small set of fringe patterns. The method allows the concurrent measurement of geometrical and chromatic data by exploiting the benefits of using a monochrome camera. The proposed methodology has been validated by measuring nominal primitive geometries and free-form shapes. The experimental results have been compared with those obtained by using a time-multiplexing gray code strategy.

  10. A Coded Structured Light System Based on Primary Color Stripe Projection and Monochrome Imaging

    Directory of Open Access Journals (Sweden)

    Armando Viviano Razionale

    2013-10-01

    Full Text Available Coded Structured Light techniques represent one of the most attractive research areas within the field of optical metrology. The coding procedures are typically based on projecting either a single pattern or a temporal sequence of patterns to provide 3D surface data. In this context, multi-slit or stripe colored patterns may be used with the aim of reducing the number of projected images. However, color imaging sensors require the use of calibration procedures to address crosstalk effects between different channels and to reduce the chromatic aberrations. In this paper, a Coded Structured Light system has been developed by integrating a color stripe projector and a monochrome camera. A discrete coding method, which combines spatial and temporal information, is generated by sequentially projecting and acquiring a small set of fringe patterns. The method allows the concurrent measurement of geometrical and chromatic data by exploiting the benefits of using a monochrome camera. The proposed methodology has been validated by measuring nominal primitive geometries and free-form shapes. The experimental results have been compared with those obtained by using a time-multiplexing gray code strategy.

  11. Optimization of a constrained linear monochromator design for neutral atom beams.

    Science.gov (United States)

    Kaltenbacher, Thomas

    2016-04-01

    A focused ground state, neutral atom beam, exploiting its de Broglie wavelength by means of atom optics, is used for neutral atom microscopy imaging. Employing Fresnel zone plates as a lens for these beams is a well established microscopy technique. To date, even for favorable beam source conditions a minimal focus spot size of slightly below 1μm was reached. This limitation is essentially given by the intrinsic spectral purity of the beam in combination with the chromatic aberration of the diffraction based zone plate. Therefore, it is important to enhance the monochromaticity of the beam, enabling a higher spatial resolution, preferably below 100nm. We propose to increase the monochromaticity of a neutral atom beam by means of a so-called linear monochromator set-up - a Fresnel zone plate in combination with a pinhole aperture - in order to gain more than one order of magnitude in spatial resolution. This configuration is known in X-ray microscopy and has proven to be useful, but has not been applied to neutral atom beams. The main result of this work is optimal design parameters based on models for this linear monochromator set-up followed by a second zone plate for focusing. The optimization was performed for minimizing the focal spot size and maximizing the centre line intensity at the detector position for an atom beam simultaneously. The results presented in this work are for, but not limited to, a neutral helium atom beam.

  12. Inductively coupled plasma-atomic emission spectroscopy: a computer controlled, scanning monochromator system for the rapid determination of the elements

    Energy Technology Data Exchange (ETDEWEB)

    Floyd, M.A.

    1980-03-01

    A computer controlled, scanning monochromator system specifically designed for the rapid, sequential determination of the elements is described. The monochromator is combined with an inductively coupled plasma excitation source so that elements at major, minor, trace, and ultratrace levels may be determined, in sequence, without changing experimental parameters other than the spectral line observed. A number of distinctive features not found in previously described versions are incorporated into the system here described. Performance characteristics of the entire system and several analytical applications are discussed.

  13. A diffracted-beam monochromator for long linear detectors in X-ray diffractometers with Bragg-Brentano parafocusing geometry.

    Science.gov (United States)

    van der Pers, N M; Hendrikx, R W A; Delhez, R; Böttger, A J

    2013-04-01

    A new diffracted-beam monochromator has been developed for Bragg-Brentano X-ray diffractometers equipped with a linear detector. The monochromator consists of a cone-shaped graphite highly oriented pyrolytic graphite crystal oriented out of the equatorial plane such that the parafocusing geometry is preserved over the whole opening angle of the linear detector. In our standard setup a maximum wavelength discrimination of 3% is achieved with an overall efficiency of 20% and a small decrease in angular resolution of only 0.02 °2θ. In principle, an energy resolution as low as 1.5% can be achieved.

  14. Probing the Role of Medication, DBS Electrode Position, and Antidromic Activation on Impulsivity Using a Computational Model of Basal Ganglia.

    Science.gov (United States)

    Mandali, Alekhya; Chakravarthy, V Srinivasa

    2016-01-01

    Everyday, we encounter situations where available choices are nearly equally rewarding (high conflict) calling for some tough decision making. Experimental recordings showed that the activity of Sub Thalamic Nucleus (STN) increases during such situations providing the extra time needed to make the right decision, teasing apart the most rewarding choice from the runner up closely trailing behind. This prolonged deliberation necessary for decision making under high conflict was absent in Parkinson's disease (PD) patients who underwent Deep Brain Stimulation (DBS) surgery of STN. In an attempt to understand the underlying cause of such adverse response, we built a 2D spiking network model (50 × 50 lattice) of Basal ganglia incorporating the key nuclei. Using the model we studied the Probabilistic learning task (PLT) in untreated, treated (L-Dopa and Dopamine Agonist) and STN-DBS PD conditions. Based on the experimental observation that dopaminergic activity is analogous to temporal difference (TD) and induces cortico-striatal plasticity, we introduced learning in the cortico-striatal weights. The results show that healthy and untreated conditions of PD model were able to more or less equally select (avoid) the rewarding (punitive) choice, a behavior that was absent in treated PD condition. The time taken to select a choice in high conflict trials was high in normal condition, which is in agreement with experimental results. The treated PD (Dopamine Agonist) patients made impulsive decisions (small reaction time) which in turn led to poor performance. The underlying cause of the observed impulsivity in DBS patients was studied in the model by (1) varying the electrode position within STN, (2) causing antidromic activation of GPe neurons. The effect of electrode position on reaction time was analyzed by studying the activity of STN neurons where, a decrease in STN neural activity was observed for certain electrode positions. We also observed that a higher antidromic

  15. Multispectral integral imaging acquisition and processing using a monochrome camera and a liquid crystal tunable filter.

    Science.gov (United States)

    Latorre-Carmona, Pedro; Sánchez-Ortiga, Emilio; Xiao, Xiao; Pla, Filiberto; Martínez-Corral, Manuel; Navarro, Héctor; Saavedra, Genaro; Javidi, Bahram

    2012-11-01

    This paper presents an acquisition system and a procedure to capture 3D scenes in different spectral bands. The acquisition system is formed by a monochrome camera, and a Liquid Crystal Tunable Filter (LCTF) that allows to acquire images at different spectral bands in the [480, 680]nm wavelength interval. The Synthetic Aperture Integral Imaging acquisition technique is used to obtain the elemental images for each wavelength. These elemental images are used to computationally obtain the reconstruction planes of the 3D scene at different depth planes. The 3D profile of the acquired scene is also obtained using a minimization of the variance of the contribution of the elemental images at each image pixel. Experimental results show the viability to recover the 3D multispectral information of the scene. Integration of 3D and multispectral information could have important benefits in different areas, including skin cancer detection, remote sensing and pattern recognition, among others.

  16. The sapphire backscattering monochromator at the Dynamics beamline P01 of PETRA III

    Science.gov (United States)

    Alexeev, P.; Asadchikov, V.; Bessas, D.; Butashin, A.; Deryabin, A.; Dill, F.-U.; Ehnes, A.; Herlitschke, M.; Hermann, R. P.; Jafari, A.; Prokhorov, I.; Roshchin, B.; Röhlsberger, R.; Schlage, K.; Sergueev, I.; Siemens, A.; Wille, H.-C.

    2016-12-01

    We report on a high resolution sapphire backscattering monochromator installed at the Dynamics beamline P01 of PETRA III. The device enables nuclear resonance scattering experiments on Mössbauer isotopes with transition energies between 20 and 60 keV with sub-meV to meV resolution. In a first performance test with 119Sn nuclear resonance at a X-ray energy of 23.88 keV an energy resolution of 1.34 meV was achieved. The device extends the field of nuclear resonance scattering at the PETRA III synchrotron light source to many further isotopes like 151Eu, 149Sm, 161Dy, 125Te and 121Sb.

  17. A high-precision cryogenically-cooled crystal monochromator for the APS diagnostics beamline

    Energy Technology Data Exchange (ETDEWEB)

    Rotela, E.; Yang, B.; Sharma, s.; Barcikowski, A.

    2000-07-24

    A high-precision cryogenically-cooled crystal monochromator has been developed for the APS diagnostics beamline. The design permits simultaneous measurements of the particle beam size and divergence. It provides for a large rotation angle, {minus}15{degree} to 180{degree}, with a resolution of 0.0005{degree}. The roll angle of the crystal can be adjusted by up to {+-}3{degree} with a resolution of 0.0001{degree}. A vertical translational stage, with a stroke of {+-}25 mm and resolution of 8 {micro}m, is provided to enable using different parts of the same crystal or to retract the crystal from the beam path. The modular design will allow optimization of cooling schemes to minimize thermal distortions of the crystal under high heat loads.

  18. Flux-enhanced monochromator by ultrasound excitation of annealed Czochralski-grown silicon crystals

    CERN Document Server

    Koehler, S; Seitz, C; Magerl, A; Mashkina, E; Demin, A

    2003-01-01

    The neutron flux from monochromator crystals can be increased by ultrasound excitation or by strain fields. Rocking curves of both a perfect float-zone silicon crystal and an annealed Czochralski silicon crystal with oxygen precipitates were measured at various levels of ultrasound excitation on a cold-neutron backscattering spectrometer. We find that the effects of the dynamic strain field from the ultrasound and the static strain field from the defects are not additive. Rocking curves were also taken at different ultrasound frequencies near resonance of the crystal/ultrasound-transducer system with a time resolution of 1 min. Pronounced effects of crystal heating are observed, which render the conditions for maximum neutron reflectivity delicate. (orig.)

  19. Measuring the criticality of the `magic condition' for a beam-expanding monochromator.

    Science.gov (United States)

    Martinson, Mercedes; Chapman, Dean

    2016-11-01

    It has been established that for cylindrically bent crystals the optimal beam characteristics occur when the geometric and single-ray foci are matched. In the beam-expanding monochromator developed for the BioMedical Imaging and Therapy beamlines at the Canadian Light Source, it was unclear how critical this `magic condition' was for preserving the transverse coherence of the beam. A study was conducted to determine whether misalignments away from the ideal conditions would severely affect the transverse coherence of the beam, thereby limiting phase-based imaging techniques. The results were that the magic condition has enough flexibility to accommodate deviations of about ±1° or ±5 keV.

  20. Adaptive silicon monochromators for high-power wigglers; design, finite-element analysis and laboratory tests.

    Science.gov (United States)

    Quintana, J P; Hart, M

    1995-05-01

    Multipole wigglers in storage rings already produce X-ray power in the range up to a few kilowatts and planned devices at third-generation facilities promise up to 30 kW. Although the power density at the monochromator position is an order of magnitude lower than that from undulators, the thermal strain field in the beam footprint can still cause severe loss of performance in X-ray optical systems. For an optimized adaptive design, the results of finite-element analysis are compared with double-crystal rocking curves obtained with a laboratory X-ray source and, in a second paper [Quintana, Hart, Bilderback, Henderson, Richter, Setterson, White, Hausermann, Krumrey & Schulte-Schrepping (1995). J. Synchotron Rad. 2, 1-5], successful tests at wiggler sources at CHESS and ESRF and in an undulator source at HASYLAB are reported.

  1. A methodology for visually lossless JPEG2000 compression of monochrome stereo images.

    Science.gov (United States)

    Feng, Hsin-Chang; Marcellin, Michael W; Bilgin, Ali

    2015-02-01

    A methodology for visually lossless compression of monochrome stereoscopic 3D images is proposed. Visibility thresholds are measured for quantization distortion in JPEG2000. These thresholds are found to be functions of not only spatial frequency, but also of wavelet coefficient variance, as well as the gray level in both the left and right images. To avoid a daunting number of measurements during subjective experiments, a model for visibility thresholds is developed. The left image and right image of a stereo pair are then compressed jointly using the visibility thresholds obtained from the proposed model to ensure that quantization errors in each image are imperceptible to both eyes. This methodology is then demonstrated via a particular 3D stereoscopic display system with an associated viewing condition. The resulting images are visually lossless when displayed individually as 2D images, and also when displayed in stereoscopic 3D mode.

  2. Image-quality assessment of monochrome monitors for medical soft copy display

    Science.gov (United States)

    Weibrecht, Martin; Spekowius, Gerhard; Quadflieg, Peter; Blume, Hartwig R.

    1997-05-01

    Soft-copy presentation of medical images is becoming part of the medical routine as more and more health care facilities are converted to digital filmless hospital and radiological information management. To provide optimal image quality, display systems must be incorporated when assessing the overall system image quality. We developed a method to accomplish this. The proper working of the method is demonstrated with the analysis of four different monochrome monitors. We determined display functions and veiling glare with a high-performance photometer. Structure mottle of the CRT screens, point spread functions and images of stochastic structures were acquired by a scientific CCD camera. The images were analyzed with respect to signal transfer characteristics and noise power spectra. We determined the influence of the monitors on the detective quantum efficiency of a simulated digital x-ray imaging system. The method follows a physical approach; nevertheless, the results of the analysis are in good agreement with the subjective impression of human observers.

  3. A Drabkin-type spin resonator as tunable neutron beam monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Piegsa, F.M., E-mail: florian.piegsa@phys.ethz.ch [ETH Zürich, Institute for Particle Physics, CH-8093 Zürich (Switzerland); Ries, D. [ETH Zürich, Institute for Particle Physics, CH-8093 Zürich (Switzerland); Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Filges, U.; Hautle, P. [Paul Scherrer Institute, CH-5232 Villigen (Switzerland)

    2015-09-11

    A Drabkin-type spin resonator was designed and successfully implemented at the multi-purpose beam line BOA at the spallation neutron source SINQ at the Paul Scherrer Institute. The device selectively acts on the magnetic moment of neutrons within an adjustable velocity band and hence can be utilized as a tunable neutron beam monochromator. Several neutron time-of-flight (TOF) spectra have been recorded employing various settings in order to characterize its performance. In a first test application the velocity dependent transmission of a beryllium filter was determined. In addition, we demonstrate that using an exponential current distribution in the spin resonator coil the side-maxima in the TOF spectra usually associated with a Drabkin setup can be strongly suppressed.

  4. Diffraction imaging for in-situ characterization of double-crystal x-ray monochromators

    CERN Document Server

    Stoupin, Stanislav; Heald, Steve M; Brewe, Dale; Meron, Mati

    2015-01-01

    Imaging of the Bragg reflected x-ray beam is proposed and validated as an in-situ method for characterization of performance of double-crystal monochromators under the heat load of intense synchrotron radiation. A sequence of images is collected at different angular positions on the reflectivity curve of the second crystal and analyzed. The method provides rapid evaluation of the wavefront of the exit beam, which relates to local misorientation of the crystal planes along the beam footprint on the thermally distorted first crystal. The measured misorientation can be directly compared to results of finite element analysis. The imaging method offers an additional insight on the local intrinsic crystal quality over the footprint of the incident x-ray beam.

  5. Bragg prism monochromator and analyser for super ultra-small angle neutron scattering studies

    Indian Academy of Sciences (India)

    Apoorva G Wagh; Sohrab Abbas; Markus Strobl; Wolfgang Treimer

    2008-11-01

    We have designed, fabricated and operated a novel Bragg prism monochromator–analyser combination. With a judicious choice of the Bragg reflection, its asymmetry and the apex angle of the silicon single crystal prism, the monochromator has produced a neutron beam with sub-arcsec collimation. A Bragg prism analyser with the opposite asymmetry has been tailored to accept a still sharper angular profile. With this optimized monochromator–analyser pair, we have attained the narrowest and sharpest neutron angular profile to date. At this facility, we have recorded the first SUSANS spectra spanning wave vector transfers ∼ 10−6 Å-1 to characterize samples containing agglomerates up to tens of micrometres in size.

  6. On the sagittal focusing of synchrotron radiation with a double crystal monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Kushnir, V.I.; Quintana, J.P.; Georgopoulos, P. (DUNU Synchrotron Research Center, Robert R. McCormick School of Engineering and Applied Science, Northwestern Univ., Evanston, IL (United States))

    1993-05-01

    A method to avoid the anticlastic bending of the second crystal in a two-crystal monochromator for synchrotron radiation is proposed. It is analytically shown that the anticlastic curvature is zero at the center of the crystal for a simply supported isotropic crystal loaded with a constant moment provided that the crystal's aspect ratio is equal to a 'golden value' dependent on the Poisson coefficient [nu]. For [nu]=0.262 (equal to [nu] in the Si(111) plane) this ratio is 2.360. Finite element results are presented on the case of the clamped crystal and show that there is a similar 'golden value' approximately equal to 1.42 for [nu]=0.262. (orig.).

  7. High-aperture monochromator-reflectometer and its usefulness for CCD calibration

    Science.gov (United States)

    Vishnyakov, Eugene A.; Shcherbakov, Alexander V.; Pertsov, Andrei A.; Polkovnikov, Vladimir N.; Pestov, Alexey E.; Pariev, Dmitry E.; Chkhalo, Nikolai I.

    2017-05-01

    We present a laboratory high-aperture monochromator-reflectometer employing laser-plasma radiation source and three replaceable Schwarzschild objectives for a certain range of applications in the soft X-ray spectral waveband. Three sets of X-ray multilayer mirrors for the Schwarzschild objectives enable operation of the reflectometer at the wavelengths of 135, 171 and 304 Å, while a goniometer with three degrees of freedom allows different measurement modes. We have used the facility for a laboratory CCD calibration at the wavelengths specified. Combined with the results of the CCD sensitivity measurements conducted in the VUV spectral waveband, the total outcome provides a more comprehensive understanding of the CCD effectivity in a wide spectral range.

  8. A water-cooled x-ray monochromator for using off-axis undulator beam.

    Energy Technology Data Exchange (ETDEWEB)

    Khounsary, A.; Maser, J.

    2000-12-11

    Undulator beamlines at third-generation synchrotrons x-ray sources are designed to use the high-brilliance radiation that is contained in the central cone of the generated x-ray beams. The rest of the x-ray beam is often unused. Moreover, in some cases, such as in the zone-plate-based microfocusing beamlines, only a small part of the central radiation cone around the optical axis is used. In this paper, a side-station branch line at the Advanced Photon Source that takes advantage of some of the unused off-axis photons in a microfocusing x-ray beamline is described. Detailed information on the design and analysis of a high-heat-load water-cooled monochromator developed for this beamline is provided.

  9. High-resolution monochromated electron energy-loss spectroscopy of organic photovoltaic materials.

    Science.gov (United States)

    Alexander, Jessica A; Scheltens, Frank J; Drummy, Lawrence F; Durstock, Michael F; Hage, Fredrik S; Ramasse, Quentin M; McComb, David W

    2017-09-01

    Advances in electron monochromator technology are providing opportunities for high energy resolution (10 - 200meV) electron energy-loss spectroscopy (EELS) to be performed in the scanning transmission electron microscope (STEM). The energy-loss near-edge structure in core-loss spectroscopy is often limited by core-hole lifetimes rather than the energy spread of the incident illumination. However, in the valence-loss region, the reduced width of the zero loss peak makes it possible to resolve clearly and unambiguously spectral features at very low energy-losses (photovoltaics (OPVs): poly(3-hexlythiophene) (P3HT), [6,6] phenyl-C61 butyric acid methyl ester (PCBM), copper phthalocyanine (CuPc), and fullerene (C60). Data was collected on two different monochromated instruments - a Nion UltraSTEM 100 MC 'HERMES' and a FEI Titan(3) 60-300 Image-Corrected S/TEM - using energy resolutions (as defined by the zero loss peak full-width at half-maximum) of 35meV and 175meV, respectively. The data was acquired to allow deconvolution of plural scattering, and Kramers-Kronig analysis was utilized to extract the complex dielectric functions. The real and imaginary parts of the complex dielectric functions obtained from the two instruments were compared to evaluate if the enhanced resolution in the Nion provides new opto-electronic information for these organic materials. The differences between the spectra are discussed, and the implications for STEM-EELS studies of advanced materials are considered. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Rotation of X-ray polarization in the glitches of a silicon crystal monochromator.

    Science.gov (United States)

    Sutter, John P; Boada, Roberto; Bowron, Daniel T; Stepanov, Sergey A; Díaz-Moreno, Sofía

    2016-08-01

    EXAFS studies on dilute samples are usually carried out by collecting the fluorescence yield using a large-area multi-element detector. This method is susceptible to the 'glitches' produced by all single-crystal monochromators. Glitches are sharp dips or spikes in the diffracted intensity at specific crystal orientations. If incorrectly compensated, they degrade the spectroscopic data. Normalization of the fluorescence signal by the incident flux alone is sometimes insufficient to compensate for the glitches. Measurements performed at the state-of-the-art wiggler beamline I20-scanning at Diamond Light Source have shown that the glitches alter the spatial distribution of the sample's quasi-elastic X-ray scattering. Because glitches result from additional Bragg reflections, multiple-beam dynamical diffraction theory is necessary to understand their effects. Here, the glitches of the Si(111) four-bounce monochromator of I20-scanning just above the Ni K edge are associated with their Bragg reflections. A fitting procedure that treats coherent and Compton scattering is developed and applied to a sample of an extremely dilute (100 micromolal) aqueous solution of Ni(NO3)2. The depolarization of the wiggler X-ray beam out of the electron orbit is modeled. The fits achieve good agreement with the sample's quasi-elastic scattering with just a few parameters. The X-ray polarization is rotated up to ±4.3° within the glitches, as predicted by dynamical diffraction. These results will help users normalize EXAFS data at glitches.

  11. Annealing effects on conductivity and optical properties of the PAni layer in ITO/PAni/PPV+DBS/Al polymer light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Pocas, L C [Instituto de Fisica, Universidade Federal de Uberlandia, CP 593, 38400-902 Uberlandia-MG (Brazil); Travain, S A [Departamento de Fisica, Instituto de Ciencias Exatas e Biologicas, Universidade de Ouro Preto, R Diogo de Vasconcelos 122, 35.400-000 Ouro Preto-MG (Brazil); Duarte, J L [Departamento de Fisica, Universidade Estadual de Londrina, CP 6001, 86051-990 Londrina-PR (Brazil); Silva, R A [Instituto de Fisica, Universidade Federal de Uberlandia, CP 593, 38400-902 Uberlandia-MG (Brazil); Giacometti, Jose A [Faculdade de Ciencias e Tecnologia, Universidade do Estado de Sao Paulo, CP 467, 19060-900, Presidente Prudente-SP (Brazil); Marletta, Alexandre [Instituto de Fisica, Universidade Federal de Uberlandia, CP 593, 38400-902 Uberlandia-MG (Brazil)

    2007-10-31

    In this work we present the electrical and optical characterization of polymer light-emitting diodes (PLEDs) using indium-tin oxide (ITO), polyaniline (PAni), poly(p-phenylene vinylene) (PPV) + dodecylbenzenesulfonate (DBS) and aluminum (Al). To minimize the conversion temperature and reduce the structural defects of PPV layers, we introduced the counter-ion DBS in the PPV precursor polymer. The best PLED electrical properties were achieved at the PPV conversion temperature of 150 deg. C. Under this condition, the ITO/PAni/PPV+DBS/Al PLED operating voltage decreases to less than a third of the value obtained with the conventional structure ITO/PPV/Al. In addition, the electrical conductivity increases and the thermal degradation decreases in the PAni layer. The line shape of the PPV electroluminescence spectrum shows no influence of the PAni layer at relatively low electrical field (12 MV m{sup -1})

  12. Thermal and structural finite element analysis of water cooled silicon monochromator for synchrotron radiation comparison of two different cooling schemes

    CERN Document Server

    Artemiev, A I; Busetto, E; Hrdy, J; Mrazek, D; Plesek, I; Savoia, A

    2001-01-01

    The article describes the results of Finite Element Analysis (FEA) of the first Si monochromator crystal distortions due to Synchrotron Radiation (SR) heat load and consequent analysis of the influence of the distortions on a double crystal monochromator performance. Efficiencies of two different cooling schemes are compared. A thin plate of Si crystal is lying on copper cooling support in both cases. There are microchannels inside the cooling support. In the first model the direction of the microchannels is parallel to the diffraction plane. In the second model the direction of the microchannels is perpendicular to the diffraction plane or in other words, it is a conventional cooling scheme. It is shown that the temperature field along the crystal volume is more uniform and more symmetrical in the first model than in the second (conventional) one.

  13. Optimization of bent perfect Si(220)-crystal monochromator for residual strain/stress instrument-Part II

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Myung-Kook [Neutron Beam Application, Korea Atomic Energy Research Institute, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of)]. E-mail: moonmk@kaeri.re.kr; Em, Vyacheslav T. [Neutron Beam Application, Korea Atomic Energy Research Institute, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of); Lee, Chang-Hee [Neutron Beam Application, Korea Atomic Energy Research Institute, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of); Mikula, Pavol [Nuclear Physics Institute and Research Centre Rez Ltd., 250 68 Rez (Czech Republic); Hong, Kwang-Pyo [Neutron Beam Application, Korea Atomic Energy Research Institute, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of); Choi, Young-Hyun [Neutron Beam Application, Korea Atomic Energy Research Institute, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of); Cheon, Jong-Kyu [Neutron Beam Application, Korea Atomic Energy Research Institute, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of); Nam, Uk-Won [Nuclear Physics Institute and Research Centre Rez Ltd., 250 68 Rez (Czech Republic); Kong, Kyung-Nam [Nuclear Physics Institute and Research Centre Rez Ltd., 250 68 Rez (Czech Republic); Korea Astronomy Observatory, Yusung, Daejeon 305-348 (Korea, Republic of); Jin, Kyung-Chan [Korea Institute of Industrial Technology, 35-3 Hongchon-Ri, Ipchang-Myun, Chonan-Si, Chungnam, 330-825 (Korea, Republic of)

    2005-11-01

    Optimized diffractometer arrangements for residual strain measurements employing curved crystal monochromators provide good luminosity and a high {delta}d/d resolution in the vicinity of usually used scattering angle 2{theta}{sub S}{approx}+/-90{sup o}. Due to a variety of designs of the diffractometers which could be installed at a constant or different take-off angles, except a few attempts, there is a lack of experimental evidence providing a help in a choice of parameters for an optimum performance. In addition to our earlier investigations with curved Si(311) monochromator employed in different diffraction geometries (see paper I [M.K. Moon et al., Physica B, submitted [1

  14. Design, Build & Test of a Double Crystal Monochromator for Beamlines I09 & I23 at the Diamond Light Source

    Science.gov (United States)

    Kelly, J.; Lee, T.; Alcock, S.; Patel, H.

    2013-03-01

    A high stability Double Crystal Monochromator has been developed at The Diamond Light Source for beamlines I09 and I23. The design specification was a cryogenic, fixed exit, energy scanning monochromator, operating over an energy range of 2.1 - 25 keV using a Si(111) crystal set. The novel design concepts are the direct drive, air bearing Bragg axis, low strain crystal mounts and the cooling scheme. The instrument exhibited superb stability and repeatability on the B16 Test Beamline. A 20 keV Si(555), 1.4 μrad rocking curve was demonstrated. The DCM showed good stability without any evidence of vibration or Bragg angle nonlinearity.

  15. 基于图像阶调与人眼视觉模型的彩色误差扩散网目调方法%Color Error Diffusion Halftoning Method Based on Image Tone and Human Visual System

    Institute of Scientific and Technical Information of China (English)

    易尧华; 于晓庆

    2009-01-01

    In the process of color error diffusion halfioning, the quality of the color halftoning image will be affected directly by the design of the error diffusion filter with different color channels. This paper studied the method of error diffusion based on tone and the human visual system(HVS), optimized the filter coefficient and the threshold by applying the luminance and chrominance HVS, and the color error diffusion halftoning method based on the image tone and HVS had been received. The results showed that this method can reduce the artifacts in color halftoning images effectively and improve the accuracy of color rendition.%在彩色误差扩散网目调处理过程中,各色通道不同的误差滤波器设计将直接影响彩色网目调图像的质量.本文对基于阶调的误差扩散方法以及人眼视觉特性进行了分析研究,应用亮度和色度人眼视觉模型对误差扩散过程中的滤波器系数和阈值进行优化,实现了基于图像阶调与人眼视觉模型的彩色误差扩散网目调方法.实验结果表明,该方法能够有效地减少彩色网目调图像的人工纹理,并显著提高再现彩色图像的色彩还原精度.

  16. Direct Spectrophotometric Determination of the Total Amount of Light Rare Earths with Arsenazo-DBS as a Chelator

    Institute of Scientific and Technical Information of China (English)

    Yuan Fuzhen

    1999-01-01

      A direct spectrophotometric method for the determination of the total light rare earths has been developed. In this method, arsenazo-DBS is used as a chelating agent with light rare earth elements in strong acidic medium (0.04-0.48 mol l-1 of acidity). The concentrations of total rare earths in 0-15 μg /(25 ml) range can be determined accurately by this method. An absorption maximum was observed at 630 nm at which a molar absorptivity of 1.14x105 l mol-1 cm-1 was determined. The method offers high selectivity and good sensitivity towards light rare earths and features simplicity and rapidity in operation. It has been applied to the determination of light rare earths in cast iron and Ni-Fe alloys.

  17. The pedunculopontine tegmental nucleus: from basic neuroscience to neurosurgical applications: arousal from slices to humans: implications for DBS.

    Science.gov (United States)

    Garcia-Rill, Edgar; Simon, Christen; Smith, Kristen; Kezunovic, Nebosja; Hyde, James

    2011-10-01

    One element of the reticular activating system (RAS) is the pedunculopontine nucleus (PPN), which projects to the thalamus to trigger thalamocortical rhythms and the brainstem to modulate muscle tone and locomotion. The PPN is a posterior midbrain site known to induce locomotion in decerebrate animals when activated at 40-60 Hz, and has become a target for DBS in disorders involving gait deficits. We developed a research program using brainstem slices containing the PPN to study the cellular and molecular organization of this region. We showed that PPN neurons preferentially fire at gamma band frequency (30-60 Hz) when maximally activated, accounting for the effects of electrical stimulation. In addition, we developed the P13 midlatency auditory evoked potential, which is generated by PPN outputs, in freely moving rats. This allows the study of PPN cellular and molecular mechanisms in the whole animal. We also study the P50 midlatency auditory evoked potential, which is the human equivalent of the rodent P13 potential, allowing us to study PPN-related processes detected in vitro, confirmed in the whole animal, and tested in humans. Previous findings on the P50 potential in PD suggest that PPN output in this disorder is overactive. This translational research program led to the discovery of a novel mechanism of sleep-wake control based on electrical coupling, pointing the way to a number of new clinical applications in the development of novel stimulants (e.g., modafinil) and anesthetics. In addition, it provides methods for monitoring therapeutic efficacy of DBS in humans and animal models.

  18. All-diamond optical assemblies for a beam-multiplexing X-ray monochromator at the Linac Coherent Light Source

    CERN Document Server

    Stoupin, S; Blank, V D; Shvyd'ko, Yu V; Goetze, K; Assoufid, L; Polyakov, S N; Kuznetsov, M S; Kornilov, N V; Katsoudas, J; Alonso-Mori, R; Chollet, M; Feng, Y; Glownia, J M; Lemke, H; Robert, A; Song, S; Sikorski, M; Zhu, D

    2014-01-01

    A double-crystal diamond (111) monochromator recently implemented at the Linac Coherent Light Source (LCLS) enables splitting of the primary X-ray beam into a pink (transmitted) and a monochromatic (reflected) branch. The first monochromator crystal with a thickness of 100 um provides sufficient X-ray transmittance to enable simultaneous operation of two beamlines. Here we report on the design, fabrication, and X-ray characterization of the first and second (300-um-thick) crystals utilized in the monochromator and the optical assemblies holding these crystals. Each crystal plate has a region of about 5 X 2 mm2 with low defect concentration, sufficient for use in X-ray optics at the LCLS. The optical assemblies holding the crystals were designed to provide mounting on a rigid substrate and to minimize mounting-induced crystal strain. The induced strain was evaluated using double-crystal X-ray topography and was found to be small over the 5 X 2 mm2 working regions of the crystals.

  19. Double-crystal monochromator for a PF 60-period soft x-ray undulator (abstract)

    Science.gov (United States)

    Ishikawa, T.; Maezawa, H.; Nomura, M.; Ando, M.

    1989-07-01

    Since undulator light is sharply collimated itself, it can be effectively monochromatized by a perfect crystal. An x-ray double-crystal monochromator with a fixed exit has been designed and built for the use of undulator light from a 60-period undulator at Photon Factory (beamline 2A). Available Bragg angle ranges from 7° to 80°. Angle scan is made by means of a goniometer outside the vacuum chamber, with the finest step of 0.1 arcsec. Magnetic fluid is used as the vacuum seal of the feedthrough. The fixed exit beam position is kept by translating the second crystal along the two mechanical guides: one for normal and the other for parallel to the crystal surface. Adjustment of the parallelity of two crystals is made manually with flexible wires. Since a total power in the central coherent portion which is limited by a 1×1-mm2 slit is not so much, a stable operation is possible without cooling the crystal. Currently, InSb (111) reflection is used. The diffracting planes of the first cyrstal is 1° off from the surface and the second is the symmetric reflection. At its fifth harmonics, brilliant undulator light of approximately 1012 photons/s mm2 with 1-eV energy resolution is available (E=2 keV).

  20. Quick scanning monochromator for millisecond in situ and in operando X-ray absorption spectroscopy

    Science.gov (United States)

    Müller, O.; Lützenkirchen-Hecht, D.; Frahm, R.

    2015-09-01

    The design and capabilities of a novel Quick scanning Extended X-ray Absorption Fine Structure (QEXAFS) monochromator are presented. The oscillatory movement of the crystal stage is realized by means of a unique open-loop driving scheme operating a direct drive torque motor. The entire drive mechanics are installed inside of a goniometer located on the atmospheric side of the vacuum chamber. This design allows remote adjustment of the oscillation frequency and spectral range, giving complete control of QEXAFS measurements. It also features a real step-scanning mode, which operates without a control loop to prevent induced vibrations. Equipped with Si(111) and Si(311) crystals on a single stage, it facilitates an energy range from 4.0 keV to 43 keV. Extended X-ray absorption fine structure spectra up to k = 14.4 Å-1 have been acquired within 17 ms and X-ray absorption near edge structure spectra covering more than 200 eV within 10 ms. The achieved data quality is excellent as shown by the presented measurements.

  1. Design, Fabrication and Measurement of Ni/Ti Multilayer Used for Neutron Monochromator

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhong; WANG Zhan-Shan; ZHU Jing-Tao; WU Yong-Rong; MU Bao-Zhong; WANG Feng-Li; QIN Shu-Ji; CHEN Ling-Yan

    2007-01-01

    Ni/Ti multilayers.which can be used for neutron monochromators,are designed,fabricated and measured.Firstly,their reflectivities are simulated based on the Nevot-Croce model.Reflectivities of two Ni/Ti multilayer mirrors with periods d=10.3nm(M1)and d=7.8nm(M2) are calculated.In the calculation,the reflectivity of the Ni/Ti multilayer is taken as a function of the gazing angle with different roughness factors δ=1.0nm and δ=1.5nm.Secondly,these two multilayers are fabricated by the direct current magnetron sputtering technology.Thirdly their structures are characterized by small-angle x-ray diffraction.The roughness factors are fitted to be O.68nm and 1.16nm for M1 and M2.respectively.Finally their reflective performances are measured on the V14 neutron beam line at the Bedin Neutron Scattering Centre(BENSC),Germany.The experimental data show that the grazing angle of the reflected neutron intensity peak increases,but the reflected neutron intensity decreases.with the decreasing periods of the multilayers.

  2. Vibration measurements of high-heat-load monochromators for DESY PETRA III extension

    Science.gov (United States)

    Kristiansen, Paw; Horbach, Jan; Döhrmann, Ralph; Heuer, Joachim

    2015-01-01

    The requirement for vibrational stability of beamline optics continues to evolve rapidly to comply with the demands created by the improved brilliance of the third-generation low-emittance storage rings around the world. The challenge is to quantify the performance of the instrument before it is installed at the beamline. In this article, measurement techniques are presented that directly and accurately measure (i) the relative vibration between the two crystals of a double-crystal monochromator (DCM) and (ii) the absolute vibration of the second-crystal cage of a DCM. Excluding a synchrotron beam, the measurements are conducted under in situ conditions, connected to a liquid-nitrogen cryocooler. The investigated DCM utilizes a direct-drive (no gearing) goniometer for the Bragg rotation. The main causes of the DCM vibration are found to be the servoing of the direct-drive goniometer and the flexibility in the crystal cage motion stages. It is found that the investigated DCM can offer relative pitch vibration down to 48 nrad RMS (capacitive sensors, 0–5 kHz bandwidth) and absolute pitch vibration down to 82 nrad RMS (laser interferometer, 0–50 kHz bandwidth), with the Bragg axis brake engaged. PMID:26134790

  3. The performance of a cryogenically cooled monochromator for an in-vacuum undulator beamline.

    Science.gov (United States)

    Zhang, Lin; Lee, Wah Keat; Wulff, Michael; Eybert, Laurent

    2003-07-01

    The channel-cut silicon monochromator on beamline ID09 at the European Synchrotron Radiation Facility is indirectly cooled from the sides by liquid nitrogen. The thermal slope error of the diffracting surface is calculated by finite-element analysis and the results are compared with experiments. The slope error is studied as a function of cooling coefficients, beam size, position of the footprint and power distribution. It is found that the slope error versus power curve can be divided into three regions: (i). The linear region: the thermal slope error is linearly proportional to the power. (ii). The transition region: the temperature of the Si crystal is close to 125 K; the thermal slope error is below the straight line extrapolated from the linear curve described above. (iii). The non-linear region: the temperature of the Si crystal is higher than 125 K and the thermal slope error increases much faster than the power. Heat-load tests were also performed and the measured rocking-curve widths are compared with those calculated by finite-element modeling. When the broadening from the intrinsic rocking-curve width and mounting strain are included, the calculated rocking-curve width versus heat load is in excellent agreement with experiment.

  4. Mechanical design aspects of a soft X-ray plane grating monochromator

    CERN Document Server

    Vasina, R; Dolezel, P; Mynar, M; Vondracek, M; Chab, V; Slezak, J A; Comicioli, C; Prince, K C

    2001-01-01

    A plane grating monochromator based on the SX-700 concept has been constructed for the Materials Science Beamline, Elettra, which is attached to a bending magnet. The tuning range is from 35 to 800 eV with calculated spectral resolving power epsilon/DELTA epsilon better than 4000 in the whole range. The optical elements consist of a toroidal prefocusing mirror, polarization aperture, entrance slit, plane pre-mirror, single plane grating (blazed), spherical mirror, exit slit and toroidal refocusing mirror. The plane grating is operated in the fixed focus mode with C sub f sub f =2.4. Energy scanning is performed by rotation of the plane grating and simultaneous translation and rotation of the plane pre-mirror. A novel solution is applied for the motion of the plane pre-mirror, namely by a translation and mechanically coupling the rotation by a cam. The slits have no moving parts in vacuum to reduce cost and increase ruggedness, and can be fully closed without risk of damage. In the first tests, a resolving pow...

  5. Beryllium, zinc and lead single crystals as a thermal neutron monochromators

    Energy Technology Data Exchange (ETDEWEB)

    Adib, M.; Habib, N. [Reactor Physics Department, NRC, Atomic Energy Authority, Cairo (Egypt); Bashter, I.I. [Physics Department, Faculty of Science, Zagazig University (Egypt); Morcos, H.N.; El-Mesiry, M.S. [Reactor Physics Department, NRC, Atomic Energy Authority, Cairo (Egypt); Mansy, M.S., E-mail: drmohamedmansy88@hotmail.com [Physics Department, Faculty of Science, Zagazig University (Egypt)

    2015-03-15

    Highlights: •Monochromatic features of Be, Zn and Pb single crystals. •Calculations of neutron reflectivity using a computer program MONO. •Optimum mosaic spread, thickness and cutting plane of single crystals. -- Abstract: The monochromatic features of Be, Zn and Pb single crystals are discussed in terms of orientation, mosaic spread, and thickness within the wavelength band from 0.04 up to 0.5 nm. A computer program MONO written in “FORTRAN-77”, has been adapted to carry out the required calculations. Calculations show that a 5 mm thick of beryllium (HCP structure) single crystal cut along its (0 0 2) plane having 0.6° FWHM are the optimum parameters when it is used as a monochromator with high reflected neutron intensity from a thermal neutron flux. Furthermore, at wavelengths shorter than 0.16 nm it is free from the accompanying higher order ones. Zinc (HCP structure) has the same parameters, with intensity much less than the latter. The same features are seen with lead (FCC structure) cut along its (3 1 1) plane with less reflectivity than the former. However, Pb (3 1 1) is more preferable than others at neutron wavelengths ⩽ 0.1 nm, since the glancing angle (θ ∼ 20°) is more suitable to carry out diffraction experiments. For a cold neutron flux, the first-order neutrons reflected from beryllium is free from the higher orders up to 0.36 nm. While for Zn single crystal is up to 0.5 nm.

  6. New high-brightness monochrome monitor based on color CRT technology

    Science.gov (United States)

    Spekowius, Gerhard; Weibrecht, Martin; D'Adda, Carlo; Antonini, Antonio; Casale, Carlo; Blume, Hartwig R.

    1997-05-01

    With increasing availability of medical image communication infrastructures, medical images are more and more displayed as soft-copies rather than as hard-copies. Often however, the image viewing environment is characterized by high ambient light, such as in surgery rooms or offices illuminated by daylight. We are describing a very-high- brightness cathode-ray-tube (CRT) monitor which accommodates these viewing conditions without the typical deterioration in resolution due to electron focal spot blooming. The three guns of a standard color CRT are used to create a high brightness monochrome monitor. The CRT has no shadow-mask, and a homogeneous P45 phosphor layer has been deposited instead of the structured red-green-blue color phosphor screen. The electron spots of the three guns are dynamically matched by applying appropriate waveforms to four additional multiple magnetic fields around the gun assembly. We evaluated the image quality of the triple-gun CRT monitor concerning parameters which are especially relevant for medical imaging applications. We have measured characteristic curves, dynamic range, veiling glare, resolution, spot profiles, and screen noise. The monitor can provide a high luminance of more than 200 fL. Due to nearly perfect matching of the three spots, the resolution is mainly determined by the beam profile of a single gun and is remarkably high even at these high luminance values. The P45 phosphor shows very little structure noise, which is an advantage for medical desktop applications. Since all relevant monitor parameters are digitally controlled, the status of the monitor can be fully characterized at any time. This feature particularly facilitates the reproduction of brightness and contrast values and hence allows easy implementation of a display function standard or to return to a desired display function that has been found useful for a given application in the past.

  7. Soil-Structure Interaction Analysis of Jack-up Platforms Subjected to Monochrome and Irregular Waves

    Institute of Scientific and Technical Information of China (English)

    Maziar Gholami KORZANI; Ali Akbar AGHAKOUCHAK

    2015-01-01

    As jack-up platforms have recently been used in deeper and harsher waters, there has been an increasing demand to understand their behaviour more accurately to develop more sophisticated analysis techniques. One of the areas of significant development has been the modelling of spudcan performance, where the load-displacement behaviour of the foundation is required to be included in any numerical model of the structure. In this study, beam on nonlinear winkler foundation (BNWF) modeling—which is based on using nonlinear springs and dampers instead of a continuum soil media—is employed for this purpose. A regular monochrome design wave and an irregular wave representing a design sea state are applied to the platform as lateral loading. By using the BNWF model and assuming a granular soil under spudcans, properties such as soil nonlinear behaviour near the structure, contact phenomena at the interface of soil and spudcan (such as uplifting and rocking), and geometrical nonlinear behaviour of the structure are studied. Results of this study show that inelastic behaviour of the soil causes an increase in the lateral displacement at the hull elevation and permanent unequal settlement in soil below the spudcans, which are increased by decreasing the friction angle of the sandy soil. In fact, spudcans and the underlying soil cause a relative fixity at the platform support, which changes the dynamic response of the structure compared with the case where the structure is assumed to have a fixed support or pinned support. For simulating this behaviour without explicit modelling of soil-structure interaction (SSI), moment-rotation curves at the end of platform legs, which are dependent on foundation dimensions and soil characteristics, are obtained. These curves can be used in a simplified model of the platform for considering the relative fixity at the soil-foundation interface.

  8. Design of DBS system based on nRF24L01%基于nRF24L01的脑深部电刺激器(DBS)通信系统设计

    Institute of Scientific and Technical Information of China (English)

    王晨光; 孙运强

    2009-01-01

    脑深部电刺激器(DBS)是一个体外可编程的植入式脉冲电刺激器,通过体外控制器的参数设置,刺激相关靶点以达到医学治疗的目的.根据DBS的基本原理及设计要求,对DBS通信方式的选择及实现方案进行了分析,选用短距离无线通信模块nRF24L01设计了一种以ATmega48单片机为核心的无线通信系统.文中给出了相关软件控制流程.通过生物实验,证明了nRF24L01通信的可行性.本文设计的硬件系统简单可靠,软件编程容易,可方便的移植到其他控制系统中.

  9. A method for evaluating image quality of monochrome and color displays based on luminance by use of a commercially available color digital camera

    Energy Technology Data Exchange (ETDEWEB)

    Tokurei, Shogo, E-mail: shogo.tokurei@gmail.com, E-mail: junjim@med.kyushu-u.ac.jp [Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan and Department of Radiology, Yamaguchi University Hospital, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Morishita, Junji, E-mail: shogo.tokurei@gmail.com, E-mail: junjim@med.kyushu-u.ac.jp [Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582 (Japan)

    2015-08-15

    Purpose: The aim of this study is to propose a method for the quantitative evaluation of image quality of both monochrome and color liquid-crystal displays (LCDs) using a commercially available color digital camera. Methods: The intensities of the unprocessed red (R), green (G), and blue (B) signals of a camera vary depending on the spectral sensitivity of the image sensor used in the camera. For consistent evaluation of image quality for both monochrome and color LCDs, the unprocessed RGB signals of the camera were converted into gray scale signals that corresponded to the luminance of the LCD. Gray scale signals for the monochrome LCD were evaluated by using only the green channel signals of the camera. For the color LCD, the RGB signals of the camera were converted into gray scale signals by employing weighting factors (WFs) for each RGB channel. A line image displayed on the color LCD was simulated on the monochrome LCD by using a software application for subpixel driving in order to verify the WF-based conversion method. Furthermore, the results obtained by different types of commercially available color cameras and a photometric camera were compared to examine the consistency of the authors’ method. Finally, image quality for both the monochrome and color LCDs was assessed by measuring modulation transfer functions (MTFs) and Wiener spectra (WS). Results: The authors’ results demonstrated that the proposed method for calibrating the spectral sensitivity of the camera resulted in a consistent and reliable evaluation of the luminance of monochrome and color LCDs. The MTFs and WS showed different characteristics for the two LCD types owing to difference in the subpixel structure. The MTF in the vertical direction of the color LCD was superior to that of the monochrome LCD, although the WS in the vertical direction of the color LCD was inferior to that of the monochrome LCD as a result of luminance fluctuations in RGB subpixels. Conclusions: The authors

  10. Development of a bent Laue beam-expanding double-crystal monochromator for biomedical X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Martinson, Mercedes, E-mail: mercedes.m@usask.ca [University of Saskatchewan, 116 Science Place, Room 163, Saskatoon, Saskatchewan (Canada); Samadi, Nazanin [University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan (Canada); Belev, George [Canadian Light Source, 44 Innovation Boulevard, Saskatoon, Saskatchewan (Canada); Bassey, Bassey [University of Saskatchewan, 116 Science Place, Room 163, Saskatoon, Saskatchewan (Canada); Lewis, Rob [University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan (Canada); Monash University, Clayton, Victoria 3800 (Australia); Aulakh, Gurpreet [University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan (Canada); Chapman, Dean [University of Saskatchewan, 116 Science Place, Room 163, Saskatoon, Saskatchewan (Canada); University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan (Canada)

    2014-03-13

    A bent Laue beam-expanding double-crystal monochromator was developed and tested at the Biomedical Imaging and Therapy beamline at the Canadian Light Source. The expander will reduce scanning time for micro-computed tomography and allow dynamic imaging that has not previously been possible at this beamline. The Biomedical Imaging and Therapy (BMIT) beamline at the Canadian Light Source has produced some excellent biological imaging data. However, the disadvantage of a small vertical beam limits its usability in some applications. Micro-computed tomography (micro-CT) imaging requires multiple scans to produce a full projection, and certain dynamic imaging experiments are not possible. A larger vertical beam is desirable. It was cost-prohibitive to build a longer beamline that would have produced a large vertical beam. Instead, it was proposed to develop a beam expander that would create a beam appearing to originate at a source much farther away. This was accomplished using a bent Laue double-crystal monochromator in a non-dispersive divergent geometry. The design and implementation of this beam expander is presented along with results from the micro-CT and dynamic imaging tests conducted with this beam. Flux (photons per unit area per unit time) has been measured and found to be comparable with the existing flat Bragg double-crystal monochromator in use at BMIT. This increase in overall photon count is due to the enhanced bandwidth of the bent Laue configuration. Whilst the expanded beam quality is suitable for dynamic imaging and micro-CT, further work is required to improve its phase and coherence properties.

  11. Integration and validation testing for PhEDEx, DBS and DAS with the PhEDEx LifeCycle agent

    CERN Document Server

    Wildish, Anthony

    2013-01-01

    The ever-increasing amount of data handled by the CMS dataflow and workflow management tools poses new challenges for cross-validation among different systems within CMS experiment at LHC. To approach this problem we developed an integration test suite based on the LifeCycle agent, a tool originally conceived for stress-testing new releases of PhEDEx, the CMS data-placement tool. The LifeCycle agent provides a framework for customising the test workflow in arbitrary ways, and can scale to levels of activity well beyond those seen in normal running. This means we can run realistic performance tests at scales not likely to be seen by the experiment for some years, or with custom topologies to examine particular situations that may cause concern some time in the future.The LifeCycle agent has recently been enhanced to become a general purpose integration and validation testing tool for major CMS services (PhEDEx, DBS, DAS). It allows cross-system integration tests of all three components to be performed in contr...

  12. Intact lexicon running slowly--prolonged response latencies in patients with subthalamic DBS and verbal fluency deficits.

    Science.gov (United States)

    Ehlen, Felicitas; Krugel, Lea K; Vonberg, Isabelle; Schoenecker, Thomas; Kühn, Andrea A; Klostermann, Fabian

    2013-01-01

    Verbal Fluency is reduced in patients with Parkinson's disease, particularly if treated with deep brain stimulation. This deficit could arise from general factors, such as reduced working speed or from dysfunctions in specific lexical domains. To test whether DBS-associated Verbal Fluency deficits are accompanied by changed dynamics of word processing. 21 Parkinson's disease patients with and 26 without deep brain stimulation of the subthalamic nucleus as well as 19 healthy controls participated in the study. They engaged in Verbal Fluency and (primed) Lexical Decision Tasks, testing phonemic and semantic word production and processing time. Most patients performed the experiments twice, ON and OFF stimulation or, respectively, dopaminergic drugs. Patients generally produced abnormally few words in the Verbal Fluency Task. This deficit was more severe in patients with deep brain stimulation who additionally showed prolonged response latencies in the Lexical Decision Task. Slowing was independent of semantic and phonemic word priming. No significant changes of performance accuracy were obtained. The results were independent from the treatment ON or OFF conditions. Low word production in patients with deep brain stimulation was accompanied by prolonged latencies for lexical decisions. No indication was found that the latter slowing was due to specific lexical dysfunctions, so that it probably reflects a general reduction of cognitive working speed, also evident on the level of Verbal Fluency. The described abnormalities seem to reflect subtle sequelae of the surgical procedure for deep brain stimulation rather than of the proper neurostimulation.

  13. Changes in GABA and glutamate concentrations during memory tasks in patients with Parkinson's disease undergoing DBS surgery.

    Science.gov (United States)

    Buchanan, Robert J; Darrow, David P; Meier, Kevin T; Robinson, Jennifer; Schiehser, Dawn M; Glahn, David C; Nadasdy, Zoltan

    2014-01-01

    Until now direct neurochemical measurements during memory tasks have not been accomplished in the human basal ganglia. It has been proposed, based on both functional imaging studies and psychometric testing in normal subjects and in patients with Parkinson's disease (PD), that the basal ganglia is responsible for the performance of feedback-contingent implicit memory tasks. To measure neurotransmitters, we used in vivo microdialysis during deep brain stimulation (DBS) surgery. We show in the right subthalamic nucleus (STN) of patients with PD a task-dependent change in the concentrations of glutamate and GABA during an implicit memory task relative to baseline, while no difference was found between declarative memory tasks. The five patients studied had a significant decrease in the percent concentration of GABA and glutamate during the performance of the weather prediction task (WPT). We hypothesize, based on current models of basal ganglia function, that this decrease in the concentration is consistent with expected dysfunction in basal ganglia networks in patients with PD.

  14. Changes in GABA and Glutamate concentrations during Memory Tasks in Patients with Parkinson’s disease undergoing DBS Surgery

    Directory of Open Access Journals (Sweden)

    Robert J Buchanan

    2014-03-01

    Full Text Available Until now direct neurochemical measurements during memory tasks have not been accomplished in the human basal ganglia. It has been proposed, based on both functional imaging studies and psychometric testing in normal subjects and in patients with Parkinson’s disease (PD, that the basal ganglia is responsible for the performance of feedback-contingent implicit memory tasks. To measure neurotransmitters, we used in-vivo microdialysis during deep brain stimulator (DBS surgery. We show in the right subthalamic nucleus (STN of patients with PD a task-dependent change in the concentrations of glutamate and GABA during an implicit memory task relative to baseline, while no difference was found between declarative memory tasks. The five patients studied had a significant decrease in the percent concentration of GABA and glutamate during the performance of the Weather Prediction Task (WPT. We hypothesize, based on current models of basal ganglia function, that this decrease in the concentration is consistent with expected dysfunction in basal ganglia networks in patients with Parkinson’s disease.

  15. Characterization of InGaN/GaN quantum well growth using monochromated valence electron energy loss spectroscopy

    OpenAIRE

    Palisaitis, J.; Lundskog, A.; Forsberg, U.; Janzén, E.; Birch, J.; Hultman, L.; Persson, P. O. Å.

    2014-01-01

    The early stages of InGaN/GaN quantum wells growth for In reduced conditions have been investigated for varying thickness and composition of the wells. The structures were studied by monochromated STEM–VEELS spectrum imaging at high spatial resolution. It is found that beyond a critical well thickness and composition, quantum dots (>20 nm) are formed inside the well. These are buried by compositionally graded InGaN, which is formed as GaN is grown while residual In is incorporated into the...

  16. Replacement of monochromator and proportional gas counter by mercuric iodide detector in X-ray powder diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Nissenbaum, J.; Levi, A.; Burger, A.; Schieber, M. (Hebrew Univ., Jerusalem (Israel). School of Applied Science and Technology)

    1983-02-01

    Low resolution and therefore low-cost mercuric iodide detectors have successfully been applied to replace the combination of a graphite monochromator and a proportional gas radiation counter used in X-ray diffractometers. The mercuric iodide detector requires a lower DC bias of only 200 V rather than the 1500 V bias needed for the proportional gas counter. The much better stopping power of HgI/sub 2/ allows higher counting efficiency and therefore a better signal-to-noise ratio. Results are shown for X-ray powder diffractions of polycrystalline cubic silicon and tetragonal HgI/sub 2/.

  17. Holographically recorded ion-etched varied line spacing grating for a monochromator at the Photon Factory BL19B

    CERN Document Server

    Fujisawa, M; Shin, S

    2001-01-01

    Holographically recorded, ion etched ruled gratings can be obtained for the varied line spacing plane grating (VPG) monochromator at the Photon Factory BL19B. A new holographic recording method makes it possible to manufacture VPGs with large varied line coefficients for reducing the aberration terms in the optical path function. The efficiency at higher photon energies and the quantity of stray light are improved in comparison with mechanically ruled gratings. The calculation shows that the much lower efficiency at higher photon energies is not intrinsic for saw-tooth type gratings. It seems to be caused instead by carbon contamination, radiation damage, deformation at manufacturing and so on.

  18. Multipurpose monochromator for the Basic Energy Science Synchrotron Radiation Center Collaborative Access Team beamlines at the Advanced Photon Source x-ray facility

    Science.gov (United States)

    Ramanathan, M.; Beno, M. A.; Knapp, G. S.; Jennings, G.; Cowan, P. L.; Montano, P. A.

    1995-02-01

    The Basic Energy Science Synchrotron Radiation Center (BESSRC) Collaborative Access Team (CAT) will construct x-ray beamlines at two sectors of the Advanced Photon Source facility. In most of the beamlines the first optical element will be a monochromator, so that a standard design for this critical component is advantageous. The monochromator is a double-crystal, fixed exit scheme with a constant offset designed for ultrahigh vacuum windowless operation. In this design, the crystals are mounted on a turntable with the first crystal at the center of rotation. Mechanical linkages are used to correctly position the second crystal and maintain a constant offset. The main drive for the rotary motion is provided by a vacuum compatible Huber goniometer isolated from the main vacuum chamber. The design of the monochromator is such that it can accommodate water, gallium, or liquid-nitrogen cooling for the crystal optics.

  19. Optimization of the bent perfect Si(311)-crystal monochromator for a residual strain/stress instrument at the HANARO reactor-Part I

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Myung-Kook [Korea Atomic Energy Research Institute, Neutron Beam Application, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of)]. E-mail: moonmk@kaeri.re.kr; Lee, Chang-Hee [Korea Atomic Energy Research Institute, Neutron Beam Application, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of); Em, Vyacheslav T. [Korea Atomic Energy Research Institute, Neutron Beam Application, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of); Mikula, Pavol [Nuclear Physics Institute and Research Centre Rez, Ltd., 250 68 Rez (Czech Republic); Hong, Kwang-Pyo [Korea Atomic Energy Research Institute, Neutron Beam Application, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of); Choi, Young-Hyun [Korea Atomic Energy Research Institute, Neutron Beam Application, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of); Cheon, Jong-Kyu [Korea Atomic Energy Research Institute, Neutron Beam Application, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of); Choi, Young-Nam [Korea Atomic Energy Research Institute, Neutron Beam Application, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of); Kim, Shin-Ae [Korea Atomic Energy Research Institute, Neutron Beam Application, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of); Kim, Sung-Kyu [Korea Atomic Energy Research Institute, Neutron Beam Application, 150 Duckjin-Dong, Yusung, Daejon 305-600 (Korea, Republic of); Jin, Kyung-Chan [Korea Institute of Industrial Technology 35-3 Hongchon-Ri, Ipchang-Myun, Chonan-Si, Chungnam 330-825 (Korea, Republic of)

    2005-12-01

    Reflectivity and resolution properties of a variety of optimized focusing monochromator performances based on cylindrically bent perfect Si-crystals were tested with the aim of evaluating their possible use in a strain/stress diffractometer. It has been found that the optimized monochromator performances of the curved Si(311) crystals (for the take-off angle 2{theta}{sub M}=60 deg.) provide a good luminosity and a sufficiently high resolution (full width at half maximum (FWHM) of the instrumental {delta}d/d-profile can be about 2x10{sup -3} in the vicinity of the lattice spacing d=0.117nm for 2{theta}{sub S}{approx}90 deg.) of the strain/stress diffractometer with the figure of merit more than one order of magnitude larger than that related to the conventional flat mosaic Ge(220) monochromator of {eta}=15{sup '}.

  20. Wake monochromator in asymmetric and symmetric Bragg and Laue geometry for self-seeding the European X-ray FEL

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni; Serkez, Svitozar; Tolkiehn, Martin

    2013-01-01

    We discuss the use of self-seeding schemes with wake monochromators to produce TW power, fully coherent pulses for applications at the dedicated bio-imaging bealine at the European X-ray FEL, a concept for an upgrade of the facility beyond the baseline previously proposed by the authors. We exploit the asymmetric and symmetric Bragg and Laue reflections (sigma polarization) in diamond crystal. Optimization of the bio-imaging beamline is performed with extensive start-to-end simulations, which also take into account effects such as the spatio-temporal coupling caused by the wake monochromator. The spatial shift is maximal in the range for small Bragg angles. A geometry with Bragg angles close to pi/2 would be a more advantageous option from this viewpoint, albeit with decrease of the spectral tunability. We show that it will be possible to cover the photon energy range from 3 keV to 13 keV by using four different planes of the same crystal with one rotational degree of freedom.

  1. Wake monochromator in asymmetric and symmetric Bragg and Laue geometry for self-seeding the European X-ray FEL

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni; Serkez, Svitozar; Tolkiehn, Martin [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-01-15

    We discuss the use of self-seeding schemes with wake monochromators to produce TW power, fully coherent pulses for applications at the dedicated bio-imaging beamline at the European X-ray FEL, a concept for an upgrade of the facility beyond the baseline previously proposed by the authors. We exploit the asymmetric and symmetric Bragg and Laue reflections (sigma polarization) in diamond crystal. Optimization of the bio-imaging beamline is performed with extensive start-to-end simulations, which also take into account effects such as the spatio-temporal coupling caused by the wake monochromator. The spatial shift is maximal in the range for small Bragg angles. A geometry with Bragg angles close to {pi}/2 would be a more advantageous option from this viewpoint, albeit with decrease of the spectral tunability. We show that it will be possible to cover the photon energy range from 3 keV to 13 keV by using four different planes of the same crystal with one rotational degree of freedom.

  2. Design and analysis of a high heat load pin-post monochromator crystal with an integral water manifold

    Energy Technology Data Exchange (ETDEWEB)

    Schildkamp, W. [Consortium for Advanced Radiation Sources, University of Chicago, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Tonnessen, T. [Rocketdyne Albuquerque Operations, 2511 C. Broadbent Parkway, N.E., Albuquerque, NM 87107 (United States)

    1996-09-01

    Conventional minichannel water cooling geometry will not perform satisfactorily for x-radiation from a wiggler source at the Advanced Photon Source. For closed-gap wiggler operation, cryogenic silicon appears to be the only option for crystals in Bragg-Bragg geometry. For operation of the wiggler at more modest critical energies ({lt}17 keV), the first crystal can be cooled by a pin-post cooling scheme, using water at room temperature as a coolant. In order to limit the water consumption to 4 gpm and hence the risk of introducing vibrations to the crystal, the intensely cooled area of the crystal was matched to the footprint of the beam, leaving a less cooled area of the crystal subject to survival in a missteered beam but not to perform as a monochromator. The manifold design avoids large areas of high water pressure that would bow the crystal. We present here the design of a pin-post monochromator consisting of a four-layer silicon manifold system and an integrally bonded 39{percent} nickel-iron alloy base plate. A transparent prototype of the design will be exhibited. Fabrication techniques and design advantages will be discussed. {copyright} {ital 1996 American Institute of Physics.}

  3. A medium-resolution monochromator for 73 keV x-rays - Nuclear resonant scattering of synchrotron radiation from 193-Ir

    CERN Document Server

    Alexeev, Pavel; Wille, Hans-Christian; Sergeev, Ilya; Herlitschke, Marcus; Leupold, Olaf; McMorrow, Desmond F; Röhlsberger, Ralf

    2016-01-01

    We report on the development and characterization of a medium resolution monochromator for synchrotron-based hyperfine spectroscopy at the 73 keV nuclear resonance of 193-Ir. The device provides high throughput of 6*10^8 ph/s in an energy bandwidth of 300(20) meV. We excited the nuclear resonance in 193-Ir at 73.04 keV and observed nuclear fluorescence of 193-Ir in Iridium metal. The monochromator allows for Nuclear Forward Scattering spectroscopy on Ir and its compounds.

  4. Non-DBS DNA Repair Genes Regulate Radiation-induced Cytogenetic Damage Repair and Cell Cycle Progression

    Science.gov (United States)

    Zhang, Ye; Rohde, Larry H.; Emami, Kamal; Casey, Rachael; Wu, Honglu

    2008-01-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in DSB repair, and its impact on cytogenetic responses has not been systematically studied. In the present study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by transfection with small interfering RNA in human fibroblast cells. The purpose of this study is to identify new roles of these selected genes on regulating DSB repair and cell cycle progression , as measured in the micronuclei formation and chromosome aberration. In response to IR, the formation of MN was significantly increased by suppressed expression of 5 genes: Ku70 in the DSB repair pathway, XPA in the NER pathway, RPA1 in the MMR pathway, and RAD17 and RBBP8 in cell cycle control. Knocked-down expression of 4 genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Furthermore, loss of XPA, P21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Most of the 11 genes that affected cytogenetic responses are not known to have clear roles influencing DBS repair. Nine of these 11 genes were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate the biological consequences after IR.

  5. Non-DBS DNA Repair Genes Regulate Radiation-induced Cytogenetic Damage Repair and Cell Cycle Progression

    Science.gov (United States)

    Zhang, Ye; Rohde, Larry H.; Emami, Kamal; Casey, Rachael; Wu, Honglu

    2008-01-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in DSB repair, and its impact on cytogenetic responses has not been systematically studied. In the present study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by transfection with small interfering RNA in human fibroblast cells. The purpose of this study is to identify new roles of these selected genes on regulating DSB repair and cell cycle progression , as measured in the micronuclei formation and chromosome aberration. In response to IR, the formation of MN was significantly increased by suppressed expression of 5 genes: Ku70 in the DSB repair pathway, XPA in the NER pathway, RPA1 in the MMR pathway, and RAD17 and RBBP8 in cell cycle control. Knocked-down expression of 4 genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Furthermore, loss of XPA, P21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Most of the 11 genes that affected cytogenetic responses are not known to have clear roles influencing DBS repair. Nine of these 11 genes were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate the biological consequences after IR.

  6. From IBS to DBS

    Directory of Open Access Journals (Sweden)

    Peter Benno MD, PhD

    2016-05-01

    Full Text Available Irritable bowel syndrome is a chronic gastrointestinal disorder characterized by abdominal pain and altered bowel habits in the absence of organic disease. We present 2 cases where diarrhea-predominant irritable bowel syndrome occurred in association with earlier intestinal infection or antibiotic treatment. Both were successfully treated with instillation of an anaerobic cultivated human intestinal microbiota. Thereafter, they were symptom free for at least 12 months. We now introduce the term dysbiotic bowel syndrome covering cases where a disturbed intestinal microbiota is assumed to be present. We recommend that restoration of the dysbiotic gut microbiota should be first-line treatment in these conditions.

  7. Comparison of detectability of a simple object with low contrast displayed on a high-brightness color LCD and a monochrome LCD.

    Science.gov (United States)

    Takahashi, Keita; Morishita, Junji; Hiwasa, Takeshi; Hatanaka, Shiro; Sakai, Shuji; Hashimoto, Noriyuki; Nakamura, Yasuhiko; Toyofuku, Fukai; Higashida, Yoshiharu; Ohki, Masafumi

    2010-07-01

    The goal of this study was to investigate the effect of the different luminance settings of a high-brightness color liquid-crystal display (LCD) on the detectability of a simple grayscale object with low contrast by use of receiver operating characteristic (ROC) analysis. The detectability of a high-brightness color LCD with two maximum-luminance settings (500 and 170 cd/m(2)) was compared with the detectability of a monochrome LCD (500 cd/m(2)). The two LCDs used in this study were calibrated to the grayscale standard display function. The average areas under the ROC curve (AUCs) and the standard deviations for all thirteen observers for the 500 cd/m(2) color LCD, 500 cd/m(2) monochrome LCD, and 170 cd/m(2) color LCD were 0.937 +/- 0.040, 0.924 +/- 0.056, and 0.915 +/- 0.068, respectively. There were no statistically significant differences in the average AUCs among the three LCD monitor conditions. On the other hand, the total observation time for the 170 cd/m(2) color LCD was significantly shorter than that for the 500 cd/m(2) color and monochrome LCDs (p LCD provided a performance comparable to the monochrome LCD for detection of a simple grayscale object with low contrast.

  8. First experimental test of a new monochromated and aberration-corrected 200 kV field-emission scanning transmission electron microscope.

    Science.gov (United States)

    Walther, T; Quandt, E; Stegmann, H; Thesen, A; Benner, G

    2006-01-01

    The first 200 kV scanning transmission electron microscope (STEM) with an imaging energy filter, a monochromator and a corrector for the spherical aberration (Cs-corrector) of the illumination system has been built and tested. The STEM/TEM concept with Koehler illumination allows to switch easily between STEM mode for analytical and TEM mode for high-resolution or in situ studies. The Cs-corrector allows the use of large illumination angles for retaining a sufficiently high beam current despite the intensity loss in the monochromator. With the monochromator on and a 3 microm slit in the dispersion plane that gives 0.26 eV full-width at half-maximum (FWHM) energy resolution we have obtained so far an electron beam smaller than 0.20 nm in diameter (FWHM as measured by scanning the spot quickly over the CCD) which contains 7 pA current and, according to simulations, should be around 0.12 nm in true size. A high-angle annular dark field (ADF) image with isotropic resolution better than 0.28 nm has been recorded with the monochromator in the above configuration and the Cs-corrector on. The beam current is still somewhat low for electron energy-loss spectroscopy (EELS) but is expected to increase substantially by optimising the condenser set-up and using a somewhat larger condenser aperture.

  9. First experimental test of a new monochromated and aberration-corrected 200 kV field-emission scanning transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Walther, T. [Center of Advanced European Studies and Research (caesar), Ludwig-Erhard-Allee 2, D-53175 Bonn (Germany)]. E-mail: walther@caesar.de; Quandt, E. [Center of Advanced European Studies and Research (caesar), Ludwig-Erhard-Allee 2, D-53175 Bonn (Germany); Stegmann, H. [Carl Zeiss Nano Technology Systems GmbH, Carl-Zeiss-Str. 56, D-73447 Oberkochen (Germany); Thesen, A. [Carl Zeiss Nano Technology Systems GmbH, Carl-Zeiss-Str. 56, D-73447 Oberkochen (Germany); Benner, G. [Carl Zeiss Nano Technology Systems GmbH, Carl-Zeiss-Str. 56, D-73447 Oberkochen (Germany)

    2006-10-15

    The first 200 kV scanning transmission electron microscope (STEM) with an imaging energy filter, a monochromator and a corrector for the spherical aberration (C {sub s}-corrector) of the illumination system has been built and tested. The STEM/TEM concept with Koehler illumination allows to switch easily between STEM mode for analytical and TEM mode for high-resolution or in situ studies. The C{sub s}-corrector allows the use of large illumination angles for retaining a sufficiently high beam current despite the intensity loss in the monochromator. With the monochromator on and a 3 {mu}m slit in the dispersion plane that gives 0.26 eV full-width at half-maximum (FWHM) energy resolution we have obtained so far an electron beam smaller than 0.20 nm in diameter (FWHM as measured by scanning the spot quickly over the CCD) which contains 7 pA current and, according to simulations, should be around 0.12 nm in true size. A high-angle annular dark field (ADF) image with isotropic resolution better than 0.28 nm has been recorded with the monochromator in the above configuration and the C {sub s}-corrector on. The beam current is still somewhat low for electron energy-loss spectroscopy (EELS) but is expected to increase substantially by optimising the condenser set-up and using a somewhat larger condenser aperture.

  10. The young stellar cluster [DBS2003] 157 associated with the H II region GAL 331.31-00.34

    Science.gov (United States)

    Pinheiro, M. C.; Abraham, Z.; Copetti, M. V. F.; Ortiz, R.; Falceta-Gonçalves, D. A.; Roman-Lopes, A.

    2012-07-01

    We report a study of the stellar content of the near-infrared (NIR) cluster [DBS2003] 157 embedded in the extended H II region GAL 331.31-00.34, which is associated with the IRAS source 16085-5138. JHK photometry was carried out in order to identify potential ionizing candidates, and the follow-up NIR spectroscopy allowed the spectral classification of some sources, including two O-type stars. A combination of NIR photometry and spectroscopy data was used to obtain the distance of these two stars, with the method of spectroscopic parallax: IRS 298 (O6 V, 3.35 ± 0.61 kpc) and IRS 339 (O9 V, 3.24 ± 0.56 kpc). Adopting the average distance of 3.29 ± 0.58 kpc and comparing the Lyman continuum luminosity of these stars with that required to account for the radio continuum flux of the H II region, we conclude that these two stars are the ionizing sources of GAL 331.31-00.34. Young stellar objects (YSOs) were searched by using our NIR photometry and mid-infrared (MIR) data from the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) survey. The analysis of NIR and MIR colour-colour diagrams resulted in 47 YSO candidates. The GLIMPSE counterpart of IRAS 16085-5138, which presents IRAS colour indices compatible with an ultracompact H II region, has been identified. The analysis of its spectral energy distribution between 2 and ?m revealed that this source shows a spectral index α= 3.6 between 2 and ?m, which is typical of a YSO immersed in a protostellar envelope. Lower limits to the bolometric luminosity and the mass of the embedded protostar have been estimated as L= 7.7 × 103 L⊙ and M= 10 M⊙, respectively, which correspond to a B0-B1 V zero-age main sequence star. Based on observations carried at the Southern Observatory for Astrophysical Research (SOAR) observatory, a joint project of the Ministério de Ciência, Tecnologia e Inovação (MCTI) of the República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the

  11. Interface of the transport systems research vehicle monochrome display system to the digital autonomous terminal access communication data bus

    Science.gov (United States)

    Easley, W. C.; Tanguy, J. S.

    1986-01-01

    An upgrade of the transport systems research vehicle (TSRV) experimental flight system retained the original monochrome display system. The original host computer was replaced with a Norden 11/70, a new digital autonomous terminal access communication (DATAC) data bus was installed for data transfer between display system and host, while a new data interface method was required. The new display data interface uses four split phase bipolar (SPBP) serial busses. The DATAC bus uses a shared interface ram (SIR) for intermediate storage of its data transfer. A display interface unit (DIU) was designed and configured to read from and write to the SIR to properly convert the data from parallel to SPBP serial and vice versa. It is found that separation of data for use by each SPBP bus and synchronization of data tranfer throughout the entire experimental flight system are major problems which require solution in DIU design. The techniques used to accomplish these new data interface requirements are described.

  12. Vibratory response of a precision double-multi-layer monochromator positioning system using a generic modeling program with experimental verification.

    Energy Technology Data Exchange (ETDEWEB)

    Barraza, J.

    1998-07-29

    A generic vibratory response-modeling program has been developed as a tool for designing high-precision optical positioning systems. The systems are modeled as rigid-body structures connected by linear non-rigid elements such as complex actuators and bearings. The full dynamic properties of each non-rigid element are determined experimentally or theoretically, then integrated into the program as inertial and stiffness matrices. Thus, it is possible to have a suite of standardize structural elements for modeling many different positioning systems that use standardized components. This paper will present the application of this program to a double-multi-layer monochromator positioning system that utilizes standardized components. Calculated results are compared to experimental modal analysis results.

  13. Measurement of vibrational spectrum of liquid using monochromated scanning transmission electron microscopy-electron energy loss spectroscopy.

    Science.gov (United States)

    Miyata, Tomohiro; Fukuyama, Mao; Hibara, Akihide; Okunishi, Eiji; Mukai, Masaki; Mizoguchi, Teruyasu

    2014-10-01

    Investigations on the dynamic behavior of molecules in liquids at high spatial resolution are greatly desired because localized regions, such as solid-liquid interfaces or sites of reacting molecules, have assumed increasing importance with respect to improving material performance. In application to liquids, electron energy loss spectroscopy (EELS) observed with transmission electron microscopy (TEM) is a promising analytical technique with the appropriate resolutions. In this study, we obtained EELS spectra from an ionic liquid, 1-ethyl-3-methylimidazolium bis (trifluoromethyl-sulfonyl) imide (C2mim-TFSI), chosen as the sampled liquid, using monochromated scanning TEM (STEM). The molecular vibrational spectrum and the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap of the liquid were investigated. The HOMO-LUMO gap measurement coincided with that obtained from the ultraviolet-visible spectrum. A shoulder in the spectrum observed ∼0.4 eV is believed to originate from the molecular vibration. From a separately performed infrared observation and first-principles calculations, we found that this shoulder coincided with the vibrational peak attributed to the C-H stretching vibration of the [C2mim(+)] cation. This study demonstrates that a vibrational peak for a liquid can be observed using monochromated STEM-EELS, and leads one to expect observations of chemical reactions or aids in the analysis of the dynamic behavior of molecules in liquid. © The Author 2014. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. In-situ metrology for the optimization of bent crystals used in hard-X-ray monochromators: Comparison between measurement and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Thomasset, Muriel, E-mail: muriel.thomasset@synchrotron-soleil.f [Synchrotron SOLEIL, L' orme des Merisiers, BP 48, 91192 Gif sur Yvette (France); Moreno, Thierry; Capitanio, Blandine; Idir, Mourad [Synchrotron SOLEIL, L' orme des Merisiers, BP 48, 91192 Gif sur Yvette (France); Bucourt, Samuel [Imagine Optic, 18 rue Charles de Gaulle, Orsay 91400 (France)

    2010-05-01

    Crystal sagittal focusing is known as one of the most efficient way of focusing synchrotron X-ray radiation from bending magnet sources, thus delivering increases photon flux at the sample position. To optimize the performance of a sagittaly bent crystal inside a monochromator, it is necessary to have knowledge of its radius of curvature. However, this measurement is not very easy to obtain. Even though the use of the X-ray beam is the ultimate source for optimizing the system, it is still necessary to have a prior knowledge of the radius of curvature as a function of the motor bender positions to avoid any catastrophic failure. In this paper, we describe a simple, efficient and accurate method of measuring the radius of curvature of sagitally bent monochromator crystals at several bending magnet beamlines at synchrotron SOLEIL. To optimize the crystal bending inside these monochromators, we used a Shack-Hartmann sensor (HP 26) developed by the Imagine Optic Company (Orsay/France). This high accuracy two-dimensional metrology tool was originally designed to be installed on a Long Trace Profiler translation stage to measure the mirrors profiles. During a period where the SOLEIL synchrotron was in shutdown, this instrument was directly mounted inside the monochromator so that the radius of curvature could be measured in-situ. This method allows us to optimize the curvature and eliminate twist before bending strongly the crystal below radii of curvature of less than 2 m. The second step in the optimization process was to use the X-ray beam for the final adjustments of the bending system, where X-ray images are then used to analyse the residual defaults of the system. Using SpotX, a ray-tracing simulation tool, these errors can be fully analysed and a fully optimized system can then be obtained. Overall, five beamlines at synchrotron SOLEIL have used in this method to optimize their monochromators.

  15. Stratifying Parkinson's Patients With STN-DBS Into High-Frequency or 60 Hz-Frequency Modulation Using a Computational Model.

    Science.gov (United States)

    Khojandi, Anahita; Shylo, Oleg; Mannini, Lucia; Kopell, Brian H; Ramdhani, Ritesh A

    2017-07-01

    High frequency stimulation (HFS) of the subthalamic nucleus (STN) is a well-established therapy for Parkinson's disease (PD), particularly the cardinal motor symptoms and levodopa induced motor complications. Recent studies have suggested the possible role of 60 Hz stimulation in STN-deep brain stimulation (DBS) for patients with gait disorder. The objective of this study was to develop a computational model, which stratifies patients a priori based on symptomatology into different frequency settings (i.e., high frequency or 60 Hz). We retrospectively analyzed preoperative MDS-Unified Parkinson's Disease Rating Scale III scores (32 indicators) collected from 20 PD patients implanted with STN-DBS at Mount Sinai Medical Center on either 60 Hz stimulation (ten patients) or HFS (130-185 Hz) (ten patients) for an average of 12 months. Predictive models using the Random Forest classification algorithm were built to associate patient/disease characteristics at surgery to the stimulation frequency. These models were evaluated objectively using leave-one-out cross-validation approach. The computational models produced, stratified patients into 60 Hz or HFS (130-185 Hz) with 95% accuracy. The best models relied on two or three predictors out of the 32 analyzed for classification. Across all predictors, gait and rest tremor of the right hand were consistently the most important. Computational models were developed using preoperative clinical indicators in PD patients treated with STN-DBS. These models were able to accurately stratify PD patients into 60 Hz stimulation or HFS (130-185 Hz) groups a priori, offering a unique potential to enhance the utilization of this therapy based on clinical subtypes. © 2017 International Neuromodulation Society.

  16. Development of a novel biosensor based on a polypyrrole-dodecylbenzene sulphonate (PPy-DBS) film for the determination of amperometric cholesterol.

    Science.gov (United States)

    Özer, Bayram Oğuz; Çete, Servet

    2017-06-01

    Herein a novel amperometric biosensor based on a conducting polymer with anionic dopant modified electrode was successfully developed for detection of cholesterol. Polypyrrole is deposited on a platinum surface and the sodium dodecylbenzene sulphonate (DBS) ion-doped polypyrrole film was electrochemically prepared by scanning the electrode potential between -0.8 and +0.8 V at a scan rate of 20 mV/s. The present electrochemical biosensor was optimized in terms of working potential, number of cycles, concentrations of monomer, and anionic dopant. Cholesterol oxidase (ChOx) was physically entrapped in PPy-DBS to construct an amperometric cholesterol biosensor. Amperometric determination is based on the electrochemical detection of H2O2 generated in the enzymatic reaction of cholesterol. Kinetic parameters, operational and storage stabilities, pH, and temperature dependencies were determined. Km and Imax were calculated as 0.11 μM and 0.967 nM/min, respectively. The operational stability results showed that 90.0% of the response current was retained after 30 activity assays. Morphology of electrodes was characterized by SEM and AFM. Additionally, contact angle measurements were made with 1 μL water of polymer film and enzyme electrode. As a result, the cholesterol biosensor suggested in this study is easy to prepare and is highly cost-effective. This composite (PPy-DBS) can supply a biocompatible and electrochemical microenvironment for immobilization of the enzyme, making this material a good candidate for the fabrication of highly sensitive and selective cholesterol biosensors.

  17. Photometric and Spectroscopic Survey of the Cluster [DBS2003] 156 Associated with the H II Region G331.1-0.5

    Science.gov (United States)

    Pinheiro, M. C.; Ortiz, R.; Abraham, Z.; Copetti, M. V. F.

    2016-05-01

    The Norma section of the Milky Way is especially interesting because it crosses three spiral arms: Sagittarius-Carina, Scutum-Crux and the Norma arm itself. Distance determinations of embedded young stellar clusters can contribute to define the spiral structure in this part of the Galaxy. However, spectrophotometric distances were obtained for only a few of these clusters in Norma. We present a photometric and spectroscopic study in the NIR of the [DBS2003] 156 stellar cluster, associated with the H II region G331.1-0.5. We aim to find the ionizing sources of the H II region and determine its distance. The cluster was observed in the J, H, and {K}{{s}} bands and eight potential massive stars were chosen among the detected sources according to color criteria; subsequent spectroscopy of these candidates was performed with the Ohio State Infrared Imager/Spectrometer spectrograph attached to the Southern Observatory for Astrophysical Research 4.1 m telescope. We identified and classified spectroscopically four early-type stars: IRS 176 (O8 V), IRS 308 (O-type), IRS 310 (O6 V), and IRS 71 (B1 Iab). Based on the proximity of IRS 176 and 308 with the radio continuum emission peaks and their relative positions with respect to the warm dust mid-infrared emission, we concluded that these two stars are the main ionizing sources of the H ii region G331.1-0.5. The mean spectrophotometric distance of IRS 176 and 310 of 3.38 ± 0.58 kpc is similar to that obtained in a previous work for two early-type stars of the neighbor cluster [DBS2003] 157 of 3.29 ± 0.58 kpc. The narrow range of radial velocities of radio sources in the area of the clusters [DBS2003] 156 and 157 and their similar visual extinction indicate that these clusters are physically associated. A common distance of 3.34 ± 0.34 kpc is derived for the system [DBS2003] 156 and 157. Based on observations obtained at the Southern Observatory for Astrophysical Research (SOAR), a joint project of the Ministério de Ci

  18. Fully automated determination of nicotine and its major metabolites in whole blood by means of a DBS online-SPE LC-HR-MS/MS approach for sports drug testing.

    Science.gov (United States)

    Tretzel, Laura; Thomas, Andreas; Piper, Thomas; Hedeland, Mikael; Geyer, Hans; Schänzer, Wilhelm; Thevis, Mario

    2016-05-10

    Dried blood spots (DBS) represent a sample matrix collected under minimal-invasive, straightforward and robust conditions. DBS specimens have been shown to provide appropriate test material for different analytical disciplines, e.g., preclinical drug development, therapeutic drug monitoring, forensic toxicology and diagnostic analysis of metabolic disorders in newborns. However, the sample preparation has occasionally been reported as laborious and time consuming. In order to minimize the manual workload and to substantiate the suitability of DBS for high sample-throughput, the automation of sample preparation processes is of paramount interest. In the current study, the development and validation of a fully automated DBS extraction method coupled to online solid-phase extraction using the example of nicotine, its major metabolites nornicotine, cotinine and trans-3'-hydroxycotinine and the tobacco alkaloids anabasine and anatabine is presented, based on the rationale that the use of nicotine-containing products for performance-enhancing purposes has been monitored by the World Anti-Doping Agency (WADA) for several years. Automation-derived DBS sample extracts were directed online to liquid chromatography high resolution/high mass accuracy tandem mass spectrometry, and target analytes were determined with support of four deuterated internal standards. Validation of the method yielded precise (CV 0.998) results. The limit of detection was established at 5 ng mL(-1) for all studied compounds, the extraction recovery ranged from 25 to 44%, and no matrix effects were observed. To exemplify the applicability of the DBS online-SPE LC-MS/MS approach for sports drug testing purposes, the method was applied to authentic DBS samples obtained from smokers, snus users, and e-cigarette users. Statistical evaluation of the obtained results indicated differences in metabolic behavior depending on the route of administration (inhalative versus buccal absorption) in terms of the

  19. Backscattering analyzer geometry as a straightforward and precise method for monochromator characterization at third-generation synchrotron-radiation sources (abstract)

    Science.gov (United States)

    Snigirev, A. A.; Lequien, S.; Suvorov, A. Yu.

    1995-02-01

    With the assessment of the third generation of synchrotron-radiation sources, insertion devices (ID) are going to become extensively used. The choice of the ID field configuration allows the optimization of the photon flux at the desired energy. This attractive situation results in a much higher flux on optical elements, mainly on monochromators for which new cooling schemes have to be developed. These latter must be characterized under operating conditions and generally, the figure of merit for monochromators is the rocking curve (RC) measurement. By varying the ID field, the monochromator may be fully characterized with regard to the heat load. To achieve this aim, we have proposed and tested a double-crystal setup where a Si analyzer crystal installed in backscattering geometry (BSG) is coupled with a silicon p-i-n photodiode as the detection system (Fig. 1). The analyzer was a standard Si wafer (111) orientation, from which we used the following Bragg reflections: 333, 444, 555, 777, 888, 999, ... to measure the RCs of monochromators keeping the analyzer fixed. We were then able to probe the formers at the respective energies 5.9, 7.9, 9.9, 13.8, 15.8, 17.8 keV, etc. Setting the analyzer crystal in BSG, we get several-fold benefits from the method: (1) A very good angular resolution (˜10-6 rad) when one combines the BSG analyzer with narrow slits (˜100 μm). (2) A high-energy resolution yielding to a calibration of the monochromator with an accuracy better than 1 eV. (3) The analyzer crystal attenuates the reflected intensity which avoids the use of any scatterer foil to count the number of photons. We directly used photodiodes which are well known to respond linearly to radiation intensities and to have a high dynamic range (more than 6 decades). (4) No fine mechanics is needed for the analyzer, just a simple manual turntable can be used to set the analyzer in BSG through the utilization of a laser beam. Results on different tests for operating liquid-N2

  20. Merging DBS with viral vector or stem cell implantation: “hybrid” stereotactic surgery as an evolution in the surgical treatment of Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Nathan C Rowland

    2016-01-01

    Full Text Available Parkinson's disease (PD is a complex neurodegenerative disorder that is currently managed using a broad array of symptom-based strategies. However, targeting its molecular origins represents the potential to discover disease-modifying therapies. Deep brain stimulation (DBS, a highly successful treatment modality for PD symptoms, addresses errant electrophysiological signaling pathways in the basal ganglia. In contrast, ongoing clinical trials testing gene and cell replacement therapies propose to protect or restore neuronal-based physiologic dopamine transmission in the striatum. Given promising new platforms to enhance target localization'such as interventional MRI-guided stereotaxy'the opportunity now exists to create hybrid therapies that combine DBS with gene therapy and/or cell implantation. In this mini-review, we discuss approaches used for central nervous system biologic delivery in PD patients in previous trials and propose a new set of strategies based on novel molecular targets. A multifaceted approach, if successful, may not only contribute to our understanding of PD pathology but could introduce a new era of disease modification.

  1. 直播卫星地面实际场强覆盖测试探析%Probe into the Practical Coverage Effect of the DBS System

    Institute of Scientific and Technical Information of China (English)

    赵琰

    2015-01-01

    我国开展卫星直播业务是为了解决全国广大农村,尤其是边远地区的广大民众收听收看广播电视难的问题,是对有线电视覆盖网的有益补充。调查其在全国的实际覆盖情况,特别是对我国边界地区的覆盖情况进行测试调查十分必要和重要。%The application of DBS ( Direct Broadcast Satellite ) system is intended to improve the coverage of TV broadcasting mainly in the country areas of China.It is an efficient way for people living in the undeveloped country side to solve the problem of watching TV.It is important and necessary to study on the methods of supervision that is suitable for this new DBS system.

  2. Application of inductively coupled plasma atomic emission spectroscopy analysis with a polychromator/monochromator combination the byproducts of coal-fired power stations

    Science.gov (United States)

    Weers, C. A.

    The by-products of coal-fired power plants may be hazardous for the environment. Good analysis methods are therefore required in order to establish either a possible usage of the by-products or their possible storage. Preliminary experiments performed with inductively coupled plasma atomic emission spectroscopy have proven very successful. Moreover, the method is cost-effective. A short description is given of the optimized system for routine analysis. The system consists of a 2- and a 15-channel polychromator in combination with a monochromator. The opportunities is provides are also described. Use of the monochromator to analyze coal and run-off water from the flue-gases desulphurization, and of the polychromators to analyze coal fly-ash is described separately.

  3. A possibility of parallel and anti-parallel diffraction measurements on neutron diffractometer employing bent perfect crystal monochromator at the monochromatic focusing condition

    Indian Academy of Sciences (India)

    Yong Nam Choi; Shin Ae Kim; Sung Kyu Kim; Sung Baek Kim; Chang-Hee Lee; Pivel Mikula

    2004-07-01

    In a conventional diffractometer having single monochromator, only one position, parallel position, is used for the diffraction experiment (i.e. detection) because the resolution property of the other one, anti-parallel position, is very poor. However, a bent perfect crystal (BPC) monochromator at monochromatic focusing condition can provide a quite flat and equal resolution property at both parallel and anti-parallel positions and thus one can have a chance to use both sides for the diffraction experiment. From the data of the FWHM and the / measured on three diffraction geometries (symmetric, asymmetric compression and asymmetric expansion), we can conclude that the simultaneous diffraction measurement in both parallel and anti-parallel positions can be achieved.

  4. DBS in the baso-lateral amygdala improves symptoms of autism and related self-injurious behaviourA case report and hypothesis on the pathogenesis of the disorder

    Directory of Open Access Journals (Sweden)

    Volker eSturm

    2013-01-01

    Full Text Available We treated a thirteen year old boy for life-threatening self-injurious behavior (SIB and severe Kanner’s autism with Deep Brain Stimulation (DBS in the amygdaloid complex as well as in the supra-amygdaloid projection system. Two DBS-electrodes were placed in both structures of each hemisphere. The stimulation contacts targeted the paralaminar, the basolateral, the central amygdala as well as the supra-amygdaloid projection system. DBS was applied to each of these structures, but only stimulation of the baso-lateral part proved effective in improving SIB and core symptoms of the autism spectrum in the emotional, social and even cognitive domains over a follow up of now 24 months. These results, which have been gained for the first time in a patient, support hypotheses, according to which the amygdala may be pivotal in the pathogeneses of autism and point to the special relevance of the baso-lateral part.

  5. 中子单色器模拟分析研究%Simulation and Analysis of Spectrum Selection Affected by Neutron Monochromator's Parameters

    Institute of Scientific and Technical Information of China (English)

    霍合勇; 唐科; 唐彬; 刘斌; 曹超

    2014-01-01

    为研究单色器对中子能谱的选择规律,本文利用MCSTAS程序模拟分析了机械速度选择器与晶体单色器几个特征参数对中子能量选择影响。分析结果显示经机械速度选择器单色选择中子注量率要下降1~2个量级,而晶体单色器要下降2~3个量级。因此,对于单色化要求比较高选用晶体单色器,对于实验时间要求较高的选用机械速度选择器。%To comprehend the selective rule of monochromator for neutron spectrum , the paper analyzes the effects of several characteristic parameters on neutron energy selection .The simulated results indicate that ve-locity selector could get high neutron flux , whose energy width -broadening becomes larger along with selected neutron peak wavelength , and crystal monochromator could get high energy resolution , whose energy width -broadening becomes narrower along with selected neutron peak wavelength .So it is suggested that crystal mono-chromator can be selected if high energy resolution is required , and mechanical velocity selector can be used if high neutron flux is required .

  6. Experimental study on the first domestic Chinese implantable DBS device%国产脑深部电刺激系统动物试验研究

    Institute of Scientific and Technical Information of China (English)

    马羽; 刘焕光; 杨岸超; 陈宁; 李路明; 郝红伟; 张建国

    2013-01-01

    目的 验证清华大学航天航空学院自主研发的国产化脑深部电刺激(DBS)系统的各项性能,为临床应用提供实验依据.方法 选取6只雄性恒河猴,年龄8 ~ 12岁,体质量10 ~ 15kg,制成偏侧恒河猴帕金森病模型,对其实施国产DBS植入相关手术,对该系统的整体性能进行了验证.结果 从2008年1月至2009年12月进行了近24个月的动物实验验证的结果显示:整套系统组织相容性良好.术中电极入脑组织顺畅,路径无偏移,电极无回缩现象.电极与延长导线连接时,对位良好,无变形,目视标志点清晰.延伸导线和脉冲发生器连接时,延伸导线插入脉冲发生器操作方便,手术操作性良好.通过对恒河猴术后近3-18个月的长期监测与观察,系统运转正常,刺激电极电阻恒定,恒河猴对刺激反应情况稳定,效果明显,系统稳定性和功能性良好.结论 清华大学研发的国产DBS系统的生物安全性、组织相容性、系统稳定性以及刺激作用有效性均已符合国家相关规定,能够满足临床推广应用的要求.%Objective To evaluate the properties of domestic deep brain stimulation (DBS) system developed by Aerospace school of Tsinghua University,which could provide experimental basis for its clinical application.Methods Six male rhesus monkeys,aged 8 to 12 years old,weighing 10 to 15 kg were choosen to be made unilateral rhesus monkey model of Parkinson's disease,and then DBS-related surgeries were performed for more than 20 times,therefore the overall system properties were testified.Results According to the results generated from the animal verification experimental,which lasted for nearly 24 months (from January 2008 to December 2009),the histocompatibility of entire system is very well.The lead could get into brain tissue smoothly without deviation during the operation,and the lead was not retracted.Leads connected well with extension in good alignment,with no distortion and clear

  7. Noite e dia e alguns monocromos psíquicos Night and day - and some psychical monochromes

    Directory of Open Access Journals (Sweden)

    Edson Luiz André de Sousa

    2006-06-01

    Full Text Available O artigo apresenta uma leitura do conto de Jack London "A sombra e o brilho" mostrando o funcionamento do princípio da mímesis no processo de identificação. Propõe-se a expressão monocromos psíquicos para esses espaços mentais de indiferenciação entre o eu e o Outro. Adota-se a tese de Caillois, que afirma que o eu é permeável ao espaço. Nessa perspectiva, o tema do duplo, amplamente desenvolvido por Freud, é fundamental. Partindo-se de notas sobre o trabalho do fotógrafo cego Bavcar, procura-se mostrar alguns traços da estrutura do olhar. O artigo finaliza mostrando as conexões possíveis dessas reflexões para a prática psicanalítica.The paper presents a reading of Jack London's tale "The Shadow and the brightness", showing how the principle of mimesis works in the process of the identification. We propose to call psychical monochromes the spaces of mental indifference between the self and the other. We follow the thesis of Roger Caillois: "the self is permeable in the space". In this perspective, the subject of the double, developped by Freud is essential. We try to show the dialectic of the structure of the look based in some notes about the work of the blind photographer Bavcar. The article finish with showing the possibles connections of all these points with the clinical work.

  8. 1,3:2,4-Dibenzylidene-D-sorbitol (DBS) and its derivatives--efficient, versatile and industrially-relevant low-molecular-weight gelators with over 100 years of history and a bright future.

    Science.gov (United States)

    Okesola, Babatunde O; Vieira, Vânia M P; Cornwell, Daniel J; Whitelaw, Nicole K; Smith, David K

    2015-06-28

    Dibenzylidene-D-sorbitol (DBS) has been a well-known low-molecular-weight gelator of organic solvents for over 100 years. As such, it constitutes a very early example of a supramolecular gel--a research field which has recently developed into one of intense interest. The ability of DBS to self-assemble into sample-spanning networks in numerous solvents is predicated upon its 'butterfly-like' structure, whereby the benzylidene groups constitute the 'wings' and the sorbitol backbone the 'body'--the two parts representing the molecular recognition motifs underpinning its gelation mechanism, with the nature of solvent playing a key role in controlling the precise assembly mode. This gelator has found widespread applications in areas as diverse as personal care products and polymer nucleation/clarification, and has considerable potential in applications such as dental composites, energy technology and liquid crystalline materials. Some derivatives of DBS have also been reported which offer the potential to expand the scope and range of applications of this family of gelators and endow the nansocale network with additional functionality. This review aims to explain current trends in DBS research, and provide insight into how by combining a long history of application, with modern methods of derivatisation and analysis, the future for this family of gelators is bright, with an increasing number of high-tech applications, from environmental remediation to tissue engineering, being within reach.

  9. A belief-propagation-based decoding method for two-dimensional barcodes with monochrome auxiliary lines robust against non-uniform geometric distortion

    Science.gov (United States)

    Kamizuru, Kohei; Nakamura, Kazuya; Kawasaki, Hiroshi; Ono, Satoshi

    2017-03-01

    Two-dimensional (2D) codes are widely used for various fields such as production, logistics, and marketing thanks to their larger capacity than one-dimensional barcodes. However, they are subject to distortion when printed on non-rigid materials, such as papers and clothes. Although general 2D code decoders correct uniform distortion such as perspective distortion, it is difficult to correct non-uniform and irregular distortion of the 2D code itself. This paper proposes a decoding method for the 2D code, which models monochrome auxiliary line recognition as Markov random field, and solves it using belief propagation.

  10. Synchrotron X-ray adaptative monochromator: study and realization of a prototype; Monochromateur adaptatif pour rayonnement X synchrotron: etude et realisation d`un prototype

    Energy Technology Data Exchange (ETDEWEB)

    Dezoret, D.

    1995-12-12

    This work presents a study of a prototype of a synchrotron X-ray monochromator. The spectral qualities of this optic are sensitive to the heat loads which are particularly important on third synchrotron generation like ESRF. Indeed, powers generated by synchrotron beams can reach few kilowatts and power densities about a few tens watts per square millimeters. The mechanical deformations of the optical elements of the beamlines issue issue of the heat load can damage their spectral efficiencies. In order to compensate the deformations, wa have been studying the transposition of the adaptive astronomical optics technology to the x-ray field. First, we have considered the modifications of the spectral characteristics of a crystal induced by x-rays. We have established the specifications required to a technological realisation. Then, thermomechanical and technological studies have been required to transpose the astronomical technology to an x-ray technology. After these studies, we have begun the realisation of a prototype. This monochromator is composed by a crystal of silicon (111) bonded on a piezo-electric structure. The mechanical control is a loop system composed by a infrared light, a Shack-Hartmann CDD and wave front analyser. This system has to compensate the deformations of the crystal in the 5 kcV to 60 kcV energy range with a power density of 1 watt per square millimeters. (authors).

  11. A spherical grating monochromator and beamline optimised for the provision of polarised synchrotron radiation in the photon energy range 20-200 eV

    Energy Technology Data Exchange (ETDEWEB)

    Finetti, P.; Holland, D.M.P. E-mail: d.m.p.holland@dl.ac.uk; Latimer, C.J.; Binns, C.; Quinn, F.M.; Bowler, M.A.; Grant, A.F.; Mythen, C.S

    2001-12-01

    The design and performance of a spherical grating monochromator and beamline optimised for experiments requiring polarised radiation are described. The beamline is mounted on a bending magnet source at the Synchrotron Radiation Source at Daresbury Laboratory, and the monochromator incorporates three gratings to cover the photon energy range 20-200 eV. The relative first- and higher-order grating efficiencies have been measured by means of photoelectron spectroscopy and have been compared to theoretical predictions. A movable aperture, placed in the optical path between the source and the first mirror, defines the photon emission directions of the beam entering the beamline. The polarisation of the radiation leaving the beamline is determined both by the vertical position of this aperture and by the modifications introduced by the beamline geometry and the optical components. The modification to the polarisation is difficult to calculate analytically, and a satisfactory quantitative assessment can only be accomplished through a combination of reflectivity and ray-tracing analysis. A reflection polarimeter has been used to obtain a full characterisation of the polarisation in the energy range 20-40 eV. These measurements have enabled the Stokes parameters to be deduced. The degree of linear polarisation has also been investigated through angle resolved photoelectron spectroscopy measurements.

  12. Cryogenically cooled bent double-Laue monochromator for high-energy undulator X-rays (50-200 keV).

    Science.gov (United States)

    Shastri, S D; Fezzaa, K; Mashayekhi, A; Lee, W K; Fernandez, P B; Lee, P L

    2002-09-01

    A liquid-nitrogen-cooled monochromator for high-energy X-rays consisting of two bent Si(111) Laue crystals adjusted to sequential Rowland conditions has been in operation for over two years at the SRI-CAT sector 1 undulator beamline of the Advanced Photon Source (APS). It delivers over ten times more flux than a flat-crystal monochromator does at high energies, without any increase in energy width (DeltaE/E approximately 10(-3)). Cryogenic cooling permits optimal flux, avoiding a sacrifice from the often employed alternative technique of filtration - a technique less effective at sources like the 7 GeV APS, where considerable heat loads can be deposited by high-energy photons, especially at closed undulator gaps. The fixed-offset geometry provides a fully tunable in-line monochromatic beam. In addition to presenting the optics performance, unique crystal design and stable bending mechanism for a cryogenically cooled crystal under high heat load, the bending radii adjustment procedures are described.

  13. Calculations and surface quality measurements of high-asymmetry angle x-ray crystal monochromators for advanced x-ray imaging and metrological applications

    Science.gov (United States)

    Zápražný, Zdenko; Korytár, Dušan; Jergel, Matej; Šiffalovič, Peter; Dobročka, Edmund; Vagovič, Patrik; Ferrari, Claudio; Mikulík, Petr; Demydenko, Maksym; Mikloška, Marek

    2015-03-01

    We present the numerical optimization and the technological development progress of x-ray optics based on asymmetric germanium crystals. We show the results of several basic calculations of diffraction properties of germanium x-ray crystal monochromators and of an analyzer-based imaging method for various asymmetry factors using an x-ray energy range from 8 to 20 keV. The important parameter of highly asymmetric monochromators as image magnifiers or compressors is the crystal surface quality. We have applied several crystal surface finishing methods, including advanced nanomachining using single-point diamond turning (SPDT), conventional mechanical lapping, chemical polishing, and chemomechanical polishing, and we have evaluated these methods by means of atomic force microscopy, diffractometry, reciprocal space mapping, and others. Our goal is to exclude the chemical etching methods as the final processing technique because it causes surface undulations. The aim is to implement very precise deterministic methods with a control of surface roughness down to 0.1 nm. The smallest roughness (˜0.3 nm), best planarity, and absence of the subsurface damage were observed for the sample which was machined using an SPDT with a feed rate of 1 mm/min and was consequently polished using a fine polishing 15-min process with a solution containing SiO2 nanoparticles (20 nm).

  14. A point-focusing small angle x-ray scattering camera using a doubly curved monochromator of a W/Si multilayer

    Science.gov (United States)

    Sasanuma, Yuji; Law, Robert V.; Kobayashi, Yuji

    1996-03-01

    A point-focusing small angle x-ray scattering (SAXS) camera using a doubly curved monochromator of a W/Si multilayer has been designed, constructed, and tested. The two radii of curvature of the monochromator are 20 400 and 7.6 mm. The reflectivity of its first-order Bragg reflection for CuKα radiation was calculated to be 0.82, being comparable to that (0.81) of its total reflection. By only 10 s x-ray exposure, scattering from a high-density polyethylene film was detected on an imaging plate (IP). A rotating-anode x-ray generator operated at 40 kV and 30 mA was used. Diffraction from rat-tail collagen has shown that the optical arrangement gives the Bragg spacing up to, at least, 30 nm for CuKα radiation. Combined with IPs, the camera may permit us to carry out time-resolved SAXS measurements for phase behaviors of liquid crystals, lipids, polymer alloys, etc., on conventional x-ray generators available in laboratories.

  15. Design,Simulation and Test for Double Focusing Si Monochromator of Neutron Residual Stress Diff ractometer%中子应力谱仪双聚焦 Si 单色器设计、模拟与测试

    Institute of Scientific and Technical Information of China (English)

    胡瑞; 刘蕴韬; 王玮; 刘中孝; 李峻宏; 高建波; 王洪立; 陈东风

    2015-01-01

    The double focusing Si monochromator was designed ,simulated and tested for the neutron residual stress diffractometer on China Advanced Research Reactor .T he optimal vertical curvature and the optimal thickness of Si wafers were obtained by SIMRES simulation program .In addition ,the figure of merit in dependence on the scattering angle ,monochromator horizontal curvature and wavelength was also deter‐mined by this program . The neutron beam test results indicate that the intensity of neutron increases by 15 times by using double focusing Si monochromator in comparison with Cu monochromator .%本文对中国先进研究堆中子应力谱仪使用的双聚焦 Si单色器进行了设计、模拟和测试。采用SIM RES模拟程序确定了单色器垂直曲率及Si片厚度的最优值,并得到品质因数与散射角、单色器水平曲率和波长的依赖关系。实际测试结果表明,与平板Cu单色器相比,使用双聚焦Si单色器样品处中子强度提高了15倍。

  16. High-Pressure-Hydrogen-Induced Spin Reconfiguration in GdFe2 Observed by 57Fe-Polarized Synchrotron Radiation Mössbauer Spectroscopy with Nuclear Bragg Monochromator

    Science.gov (United States)

    Mitsui, Takaya; Imai, Yasuhiko; Hirao, Naohisa; Matsuoka, Takahiro; Nakamura, Yumiko; Sakaki, Kouji; Enoki, Hirotoshi; Ishimatsu, Naoki; Masuda, Ryo; Seto, Makoto

    2016-12-01

    57Fe-polarized synchrotron radiation Mössbauer spectroscopy (PSRMS) with an X-ray phase plate and a nuclear Bragg monochromator was used to study ferrimagnetic GdFe2 in high-pressure hydrogen. The pressure-dependent spectra clearly showed a two-step magnetic transition of GdFe2. 57Fe-PSRMS with circular polarization gave direct evidence that the Fe moment was directed parallel to the net magnetization of the GdFe2 hydride at 20 GPa. This spin configuration was opposite to that of the initial GdFe2, suggesting an extreme weakening of the antiferromagnetic interaction between Fe and Gd. 57Fe-PSRMS enables the characterization of the nonuniform properties of iron-based polycrystalline powder alloys. The excellent applicability of 57Fe-PSRMS covers a wide range of scientific fields.

  17. A table-top monochromator for tunable femtosecond XUV pulses generated in a semi-infinite gas cell: Experiment and simulations.

    Science.gov (United States)

    von Conta, A; Huppert, M; Wörner, H J

    2016-07-01

    We present a new design of a time-preserving extreme-ultraviolet (XUV) monochromator using a semi-infinite gas cell as a source. The performance of this beamline in the photon-energy range of 20 eV-42 eV has been characterized. We have measured the order-dependent XUV pulse durations as well as the flux and the spectral contrast. XUV pulse durations of ≤40 fs using 32 fs, 800 nm driving pulses were measured on the target. The spectral contrast was better than 100 over the entire energy range. A simple model based on the strong-field approximation is presented to estimate different contributions to the measured XUV pulse duration. On-axis phase-matching calculations are used to rationalize the variation of the photon flux with pressure and intensity.

  18. A compact low cost “master–slave” double crystal monochromator for x-ray cameras calibration of the Laser MégaJoule Facility

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, S., E-mail: sebastien.hubert@cea.fr; Prévot, V.

    2014-12-21

    The Alternative Energies and Atomic Energy Commission (CEA-CESTA, France) built a specific double crystal monochromator (DCM) to perform calibration of x-ray cameras (CCD, streak and gated cameras) by means of a multiple anode diode type x-ray source for the MégaJoule Laser Facility. This DCM, based on pantograph geometry, was specifically modeled to respond to relevant engineering constraints and requirements. The major benefits are mechanical drive of the second crystal on the first one, through a single drive motor, as well as compactness of the entire device. Designed for flat beryl or Ge crystals, this DCM covers the 0.9–10 keV range of our High Energy X-ray Source. In this paper we present the mechanical design of the DCM, its features quantitatively measured and its calibration to finally provide monochromatized spectra displaying spectral purities better than 98%.

  19. Application of human DBS system in establishment of the deep brain stimulation monkey model%人用DBS系统在脑深部电刺激猴模型构建中的应用

    Institute of Scientific and Technical Information of China (English)

    曹依群; 殷佩浩; 周晓平; 陈鑫; 葛忆秦

    2013-01-01

    目的 探讨人用脑深部电刺激(DBS)系统在构建猴脑深部电刺激模型中的应用.方法 4只偏侧帕金森病(PD)猴模型,按照猴脑立体定向图谱,在右侧丘脑底核(STN)植入脑深部刺激电极(Medtronic3389),其中刺激组2只猴同期皮下植入Medtronic 7495型连接导线和Soletra TM7426型脉冲发生器,术后一周给予慢性高频电刺激.另2只偏侧PD模型猴仅在右侧STN植入电极,不植入脉冲发生器,作为对照组.连续观察12个月,进行运动障碍评分观察和阿朴吗啡(APO)诱发旋转实验.结果 术后影像学观察电极前端均位于STN核范围内;刺激组同期植入脉冲发生器给予慢性高频电刺激,猴偏侧帕金森样症状明显改善,有效高频电刺激可以立即停止APO所诱发的旋转,而对照组在观察期内症状无明显缓解.结论 人用DBS系统通过立体定向技术植入猴脑内特定靶点,可以有效的建立DBS动物模型,为DBS在神经系统疾病中的应用研究提供了良好的实验模型.%Objective To investigate application of human deep brain stimulation (DBS) system in establishment of deep brain stimulation monkey model.Methods Four hemiparkinsonian monkeys were implanted with DBS leads in right subthalamic nucleus (STN) according to stereotaxic atlas of monkey brain.Two monkeys (stimulating group) were implanted subcutaneous internal pulse generators (IPG) in back and connected with leads by extension wires.Another two monkeys were served as control group without IPG implanted.One week later,the IPG was turned on to determine the optimal stimulating parameters,using apomorphine (APO)-induced rotation as a behavioral readout.Animal behavior was scored over a 12-month period using the modified disability rating scale of hemiparkinsonian monkeys (DRSH).Results Post-operative imaging studies confirmed optimal locations of lead contacts.The behavioral observation and APO-induced rotation test indicate that Parkinson disease (PD

  20. Estimulação cerebral contínua (DBS talâmica para controle do tremor Deep brain stimulation of VIM thalamic nucleus for tremor control

    Directory of Open Access Journals (Sweden)

    José Augusto Nasser

    2002-06-01

    Full Text Available OBJETIVO: Apresentamos resultados da estimulação contínua do núcleo ventral intermédio (VIM talâmico para o controle do tremor. MÉTODO: Quatro pacientes foram selecionados no período de outubro de 1999 a janeiro de 2001 com tremor incapacitante refratário à farmacoterapia. Dois pacientes apresentavam tremor essencial (TE bilateral e 2 pacientes tremor de repouso por doença de Parkinson (DP, um à direita e outro à esquerda. Após avaliação sistemática, foram submetidos ao implante de eletrodo talâmico, modelo DBS 3387(Medtronic, para estimulação cerebral profunda (ECP com alta frequência, sendo este bilateral nos casos de TE e unilateral nos casos com tremor por DP. RESULTADOS: Os pacientes tiveram seu seguimente clínico até o presente, com média de 12 meses, sendo observada a eficácia da estimulação do núcleo VIM no controle dos disparos das células do tremor. As complicações temporárias do tipo parestesias, disartrias e discreto aumento do tônus foram revertidas após o ajuste dos parâmetros de estimulação. CONCLUSÃO: Os resultados confirmam os achados da literatura, de que a estimulação talâmica é excelente opção terapêutica no tratamento do tremor, havendo possibilidade de estimulação talâmica bilateral simultânea com segurança.PURPOSE: We present our results in 4 patients with tremor, in whom electrodes (uni and bilateral for Deep Brain Stimulation (DBS were implanted in the ventral intermediate nucleus (VIM of the thalamus. METHOD: Four patients with disabling tremor, with drug-resistant spite of optimum therapeutic trials with poor response were referred to do surgery. Two patients had bilateral essential tremor. These patients were implanted with electrodes for DBS 3387 (Medtronic. Two patients had unilateral parkinsonian tremor and they received unilateral implantation of model 3387 DBS. RESULTS: All four patients showed relieve of the tremor symptoms with significant tremor control seen at

  1. Method for characterization of a spherically bent crystal for K.alpha. X-ray imaging of laser plasmas using a focusing monochromator geometry

    Science.gov (United States)

    Kugland, Nathan; Doeppner, Tilo; Glenzer, Siegfried; Constantin, Carmen; Niemann, Chris; Neumayer, Paul

    2015-04-07

    A method is provided for characterizing spectrometric properties (e.g., peak reflectivity, reflection curve width, and Bragg angle offset) of the K.alpha. emission line reflected narrowly off angle of the direct reflection of a bent crystal and in particular of a spherically bent quartz 200 crystal by analyzing the off-angle x-ray emission from a stronger emission line reflected at angles far from normal incidence. The bent quartz crystal can therefore accurately image argon K.alpha. x-rays at near-normal incidence (Bragg angle of approximately 81 degrees). The method is useful for in-situ calibration of instruments employing the crystal as a grating by first operating the crystal as a high throughput focusing monochromator on the Rowland circle at angles far from normal incidence (Bragg angle approximately 68 degrees) to make a reflection curve with the He-like x-rays such as the He-.alpha. emission line observed from a laser-excited plasma.

  2. Electrodos poliméricos de PPy/PVS y PPy/DBS cómo cátodos en baterías de Zinc y Magnesio

    OpenAIRE

    Granados García, Jorge Enrique

    2012-01-01

    En este proyecto se estudia la respuesta de los polímero PPy/PVS y PPy/DBS al ser usados como cátodos en baterías poliméricas con ánodos de Zinc y Magnesio. Se tratará de obtener las mejores películas poliméricas que incorporen estos cationes durante la descarga y los expulsen durante la recarga de la batería. Este esquema conjuga las buenas características del Zn y Mg metálico para ser usado como ánodo de baterías con las buenas propiedades de los polímeros conductores y la po...

  3. The effect in Sodium Dodecylbenzenesulfonate(DBS) on the population quantity of Paramecium aurelia%十二烷基苯磺酸钠对双小核草履虫种群数量的影响

    Institute of Scientific and Technical Information of China (English)

    李莉; 娄玉乾; 王文彬; 冯金儒; 张茜

    2011-01-01

    在实验条件下,研究了十二烷基苯磺酸钠(DBS)对双小核草履虫(Paramecium aurelia)种群数量的影响.结果表明,较高浓度的DBS对双小核草履虫具有急性毒性效应,其24 h-LC50为9.74 mg/L;仿生活污水的DBS浓度(0.2~1.0 mg/L)和0 mg/L中双小核草履虫增长率之间无显著性差异(P>0.05),说明含有1.0 mg/L以下浓度DBS的生活污水对双小核草履虫的种群数量增长无显著影响.

  4. An efficient plane-grating monochromator based on conical diffraction for continuous tuning in the entire soft X-ray range including tender X-rays (2-8 keV).

    Science.gov (United States)

    Jark, Werner

    2016-01-01

    Recently it was verified that the diffraction efficiency of reflection gratings with rectangular profile, when illuminated at grazing angles of incidence with the beam trajectory along the grooves and not perpendicular to them, remains very high for tender X-rays of several keV photon energy. This very efficient operation of a reflection grating in the extreme off-plane orientation, i.e. in conical diffraction, offers the possibility of designing a conical diffraction monochromator scheme that provides efficient continuous photon energy tuning over rather large tuning ranges. For example, the tuning could cover photon energies from below 1000 eV up to 8 keV. The expected transmission of the entire instrument is high as all components are always operated below the critical angle for total reflection. In the simplest version of the instrument a plane grating is preceded by a plane mirror rotating simultaneously with it. The photon energy selection will then be made using the combination of a focusing mirror and exit slit. As is common for grating monochromators for soft X-ray radiation, the minimum spectral bandwidth is source-size-limited, while the bandwidth can be adjusted freely to any larger value. As far as tender X-rays (2-8 keV) are concerned, the minimum bandwidth is at least one and up to two orders of magnitude larger than the bandwidth provided by Si(111) double-crystal monochromators in a collimated beam. Therefore the instrument will provide more flux, which can even be increased at the expense of a bandwidth increase. On the other hand, for softer X-rays with photon energies below 1 keV, competitive relative spectral resolving powers of the order of 10000 are possible.

  5. Quantification de la Charge Virale et tests de résistance du VIH-1 aux ARV à partir d’échantillons DBS (Dried Blood Spots chez des patients Guinéens sous traitement antirétroviral

    Directory of Open Access Journals (Sweden)

    Nestor Bangoura

    2015-05-01

    Full Text Available Problématique: Comme dans plusieurs pays du Sud, le suivi virologique des patients sous traitement antirétroviral (TARV en Guinée est timide voire inexistant dans certaines localités. Le but de cette étude était d’évaluer la faisabilité technique et logistique de l’utilisation des DBS dans les tests de charge virale (CV et de génotypage.Méthode: De septembre à octobre 2010, les DBS ont été préparés à partir de prélèvements sanguins de patients adultes sous TARV. Le délai d’envoi des échantillons au laboratoire de référence était de 30 jours maximum après le prélèvement et se faisait à température ambiante. La CV a été quantifiée et les échantillons de patients en échec virologique (CV ≥ 3 log10 copies/mL ont été génotypés selon le protocole de l’ANRS. L’algorithme de Stanford version 6.0.8 a été utilisé pour l’analyse et l’interprétation des mutations de résistance.Résultats: Parmi les 136 patients inclus, 129 et 7 étaient respectivement sous première et deuxième ligne de traitement avec une médiane de suivi de 35 mois [IQR: 6-108]. L’échec virologique a été noté chez 33 patients. Parmi eux, 84.8% (n = 28/33 ont bénéficié d’ungénotypage. Le taux de résistance global était de 14% (n = 19/136. Le CRF02_AG était le sous type viral le plus prévalent (82%; n = 23.Conclusion: En plus de montrer la faisabilité technique et logistique des tests de CV et de génotypage à partir des DBS, ces résultats montrent l’intérêt de leurs utilisations dans le suivi virologique des patients sous TARV. Cette étude a permis également de documenter l’échec virologique, la résistance aux ARV et la diversité génétique du VIH-1 en Guinée.Mots clés: VIH-1, Résistance aux ARV, DBS (Dried Blood Spots, Guinée Conakry, Génotypage,Charge Virale. Quantification of Viral load and resistance tests of HIV-1 to ARVs from dried blood spotssamples in Guinean patients undergoing

  6. High-efficiency B₄C/Mo₂C alternate multilayer grating for monochromators in the photon energy range from 0.7 to 3.4 keV.

    Science.gov (United States)

    Choueikani, Fadi; Lagarde, Bruno; Delmotte, Franck; Krumrey, Michael; Bridou, Françoise; Thomasset, Muriel; Meltchakov, Evgueni; Polack, François

    2014-04-01

    An alternate multilayer (AML) grating has been prepared by coating an ion etched lamellar grating with a B4C/Mo2C multilayer (ML) having a layer thickness close to the groove depth. Such a structure behaves as a 2D synthetic crystal and can reach very high efficiencies when the Bragg condition is satisfied. This AML coated grating has been characterized at the SOLEIL Metrology and Tests Beamline between 0.7 and 1.7 keV and at the four-crystal monochromator beamline of Physikalisch-Technische Bundesanstalt (PTB) at BESSY II between 1.75 and 3.4 keV. A peak diffraction efficiency of nearly 27% was measured at 2.2 keV. The measured efficiencies are well reproduced by numerical simulations made with the electromagnetic propagation code CARPEM. Such AML gratings, paired with a matched ML mirror, constitute efficient monochromators for intermediate energy photons. They will extend the accessible energy for many applications as x-ray absorption spectroscopy or x-ray magnetic circular dichroism experiments.

  7. Extension of self-seeding scheme with single crystal monochromator to lower energy < 5 keV as a way to generate multi-TW scale pulses at the European XFEL

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2012-01-01

    We propose a use of the self-seeding scheme with single crystal monochromator to produce high power, fully-coherent pulses for applications at a dedicated bio-imaging beamline at the European X-ray FEL in the photon energy range between 3.5 keV and 5 keV. We exploit the C(111) Bragg reflection (pi-polarization) in diamond crystals with a thickness of 0.1 mm, and we show that, by tapering the 40 cells of the SASE3 type undulator the FEL power can reach up to 2 TW in the entire photon energy range. The present design assumes the use of a nominal electron bunch with charge 0.1 nC at nominal electron beam energy 17.5 GeV. The main application of the scheme proposed in this work is for single shot imaging of individual protein molecules.

  8. Structure Design and Accuracy Testing of Monochromator in a Soft X-Ray Spectromicroscopic Beamline%软X射线谱学显微光束线单色器结构设计及精度测试

    Institute of Scientific and Technical Information of China (English)

    龚学鹏; 卢启鹏; 彭忠琦

    2013-01-01

    In order to satisfy the technical requirement of soft X-ray microscopy beamline in Shanghai Synchrotron Radiation Facility (SSRF), whose key assembly monochromator is designed. Wavelength scanning movement principle of monochromator is described. Design scheme of wavelength scanning mechanism is discussed, and factors affecting the angular repeatability of plane mirror and plane grating are analyzed in detail; switching mechanism of plane grating is described, and horizontal deviation, vertical deviation, roll angle precision, yaw angle precision and pitch angle precision are analyzed in detail; six-bar parallel mechanism is used for adjusting the UHV-chamber, and adjusting range and resolution of the bar are analyzed. The entire structure of monochromator is presented, and its precision testing is performed. Results show that the angular repeatability of plane mirror and plane grating are 0.166" and 0.149", and roll, yaw and pitch angular repeatability of plane grating switching mechanism are 0. 08", 0.12" and 0.05", indicating that structure design and precision of monochromator satisfy the technical demand.%针对上海光源谱学显微光束线站的性能要求,对其核心部件单色器进行结构设计.阐述了单色器的扫描运动原理,论述了波长扫描机构的设计方案,具体分析平面镜和光栅的转角重复精度影响因素;描述光栅切换机构,着重分析其水平偏差、垂直偏差、滚角、摆角和投角的精度问题;采用六杆并联机构的方案完成镜箱调节机构的设计,分析其支杆的调节范围和分辨力情况.给出了单色器的结构,并且对其精度进行了测试.测试结果表明,平面镜和光栅的转角重复精度分别为0.166″和0.149″;光栅切换机构的滚角、摆角和投角的重复精度分别为0.08″、0.12″和0.05″.这说明了单色器的结构设计方案和机械精度满足技术要求.

  9. 变包含角平面光栅单色器及其关键技术%The variable included angle plane grating monochromator and the key technology

    Institute of Scientific and Technical Information of China (English)

    陈家华; 薛松; 卢启鹏; 彭忠琦; 邰仁忠; 王勇; 陈明; 吴坤

    2011-01-01

    This article discusses the design of a variable included angle plane grating monochromator (VAPGM) on the soft X-ray spectromicroscopy beam-line at Shanghai Synchrotron Radiation Facility (SSRF).The precision scanning system of sin-bar meets the requirements through resolving the high precision repeatability of mechanical transmission system; the inner path water cooling structure of the plane mirror controls the thermal deformation of the mirror surface; the huge dimension and quadrate flange chamber ensures the ultra high vacuum (UHV) which the VAPGM requires.Finally, the main capabilities of the monochromator, including the energy range, energy resolution and energy repeatability, reach the design requirements completely.%分析设计并研制了上海光源软X射线谱学显微光束线站的变包含角平面光栅单色器,经过精密加工调试,保证了扫描系统的转角重复精度;采用多孔腔内部通道水冷方法,控制了镜子表面热变形;完成真空箱体大尺寸方法兰加工与密封,达到了单色器工作所需的超高真空.通过上述关键部件的精确掌控,确保了单色器主要性能--光子能量范围、能量分辨率和能量重复性,均优于设计指标.

  10. 脑脊液蛋白四连接素在脑深部电刺激治疗前后的表达变化%Expression of tetranectin in the cerebrospinal fluid of patients with Parkinson disease pre- and post-DBS

    Institute of Scientific and Technical Information of China (English)

    王尔松; 胡锦; 匡雄辉; 奚才华; 姚海军; 胡杰; 呼建文; 江澄川

    2011-01-01

    Objective To know whether or not tetranectin in cerebrospinal fluid (CSF) might serve as a potential biomarker in assessing and following therapeutic efficacy of deep brain stimulation ( DBS) in Parkinson disease ( PD) patients. Methods Two-dimensional difference gel electrophoresis ( DIGE) technique, in combination with matrix-assisted laser desorption/ionization-time of flight mass spectrometry ( MALDI-TOF MS) , was used to determine the differentially expressed tetranectin and apolipoprotein A - I ( apo A- I ) during the perioperative period in the CSF of PD patients who underwent bilateral subthalamic nucleus ( STN ) DBS procedures. Western blotting was used to validate the data of proteomic analysis from the perioperative period, and also to determine the exact changes of these proteins in follow -up period. Results DIGE and Western blotting analysis both showed that the expression levels of tetranectin and apo A- I were not significantly changed in perioperative period. In follow-up period, the expression level of apo A- I remained stable whereas tetranectin was significantly increased , and interestingly, while the DBS was ceased in one patient because of suicide attempt , the level of tetranectin was significantly decreased . These changes of tetranectin paralleled the observed clinical effects of DBS . Conclusions Our preliminary results suggest that the variation of the expression level of tetranectin is related to the STN DBS , and tetranectin in CSF might thereby serve as a potential biomarker for DBS.%目的 研究帕金森病(PD)患者脑脊液蛋白四连接素在脑深部电刺激(DBS)治疗前后的表达变化,了解四连接素有无可能成为DBS治疗PD的生物标记物.方法 采用荧光差异凝胶电泳(DICE)和基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)鉴定技术分析PD患者脑脊液中四连接素和载脂蛋白A-I在DBS治疗围手术期的表达变化,应用Western blotting验证围手术期的变化及

  11. 极高分辨变包含角平面光栅单色器关键技术及检测方法研究%Key technologies and the performance measuring methods in variable included angle plane grating monochromator

    Institute of Scientific and Technical Information of China (English)

    卢启鹏; 宋源; 龚学鹏; 马磊

    2016-01-01

    变包含角平面光栅单色器具有分辨率高和光通量高等优点,被广泛应用于各科研领域,并且随着相关领域研究的不断深入,迫切需要提高其光谱分辨率,以满足使用需求。为研究探索极高分辨率变包含角平面光栅单色器,结合上海同步辐射光源光束线,重点研究影响单色器分辨率的关键因素;对单色器光学元件表面热负载进行分析,设计冷却系统,降低热负载产生的影响;研究变包含角平面光栅单色器转角精度等检测方法。结果表明,根据推导出的变包含角平面光栅单色器光学放大倍数与单色器分辨率的关系式,达到优选极高分辨率工作模式的目的;加入冷却系统后,单色器前置平面镜因受热负载影响而产生的最大斜率误差由8.1μrad降到3.1μrad;设计可应用于变包含角光栅单色器分辨率达5×104的转角精度检测方法,检测精度可达0.026″。该研究将为第三代同步辐射光源中建造极高分辨变包含角单色器提供帮助。%The variable-included-angle plane grating monochromator is broadly used in high performance soft X-ray due to its superior performance,such as high throughput and high resolution.With the development of Science,improving and optimizing the resolution of variables-included-angle plane grating monochromator is necessary and urgently.In order to study and explore the ultra-high resolution of variables-included-angle plane grating monochromator in synchrotron radiation,some issues were researched in this work.Firstly,the relationship between working modes of variables-included-angle plane grating monochromator with different cf is emphatically researched.According to the relationship,the high resolution working modes of the mono-chromator can be selected.Secondly,we studied the effects of high heat load on the optical system by using the simulation software and designed an appropriate cooling system in

  12. Comment on {open_quote}{open_quote}Comments on the use of asymmetric monochromators for x-ray diffraction on a synchrotron source{close_quote}{close_quote} [Rev. Sci. Instrum. {bold 66}, 2174 (1995)

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez del Rio, M. [European Synchrotron Radiation Facility, B.P. 220, 38043 Grenoble-Cedex (France); Cerrina, F. [Center for X-ray Lithography, 3731 Schneider Dr., Stoughton, Wisconsin 53589 (United States)

    1996-10-01

    In the article {open_quote}{open_quote}Comments on the use of asymmetric monochromators for x-ray diffraction on a synchrotron source,{close_quote}{close_quote} by Colin Nave, Ana Gonzalez, Graham Clark, Sean McSweeney, Stewart Cummings, and Michael Hart, Rev. Sci. Instrum. {bold 66}, 2174 (1995), paragraph II, the authors{close_quote} unfamiliarity with our modeling codes leads them to claim that our approach to treat bent-asymmetrically cut crystals in ray tracing calculations is incorrect. Since SHADOW is a widely used code, it is important to correct any misunderstandings, and we give here arguments to demonstrate that our approach is perfectly valid, and the arguments used by the authors to criticize our method are based on an unwarranted conclusion extracted from one of our previous articles. We show that SHADOW, when properly run, treats the cases raised exactly. Indeed, their arguments provide a nice benchmark test for verifying the accuracy of SHADOW {copyright} {ital 1996 American Institute of Physics.}

  13. Half-Tone Video Images Of Drifting Sinusoidal Gratings

    Science.gov (United States)

    Mulligan, Jeffrey B.; Stone, Leland S.

    1991-01-01

    Digital technique for generation of slowly moving video image of sinusoidal grating avoids difficulty of transferring full image data from disk storage to image memory at conventional frame rates. Depends partly on trigonometric identity by which moving sinusoidal grating decomposed into two stationary patterns spatially and temporally modulated in quadrature. Makes motion appear smooth, even at speeds much less than one-tenth picture element per frame period. Applicable to digital video system in which image memory consists of at least 2 bits per picture element, and final brightness of picture element determined by contents of "lookup-table" memory programmed anew each frame period and indexed by coordinates of each picture element.

  14. Cooling and positioning of DIRSP: a half-ton gorilla

    Science.gov (United States)

    Higham, Dave; Frodsham, D. Gary; Waugh, Paul; Tomisino, Fred

    1999-07-01

    The Dynamic InfraRed Scene Projector (DIRSP) meets Army requirements for low-background hardware-in-the-loop testing of imaging infrared sensors. These requirements are met using cryogenic, vacuum technology to cool optical elements and emitter array sources. This paper discusses design and fabrication of two DIRSP subsystems, the Environmental Conditioning Subsystem, and the Mounting Platform Subsystem. These two subsystems enclose and support the Projection Optics Subsystem, and the Infrared Emitter Subsystem.

  15. Reply to {open_quote}{open_quote}Comment on {open_quote}Comments on the use of asymmetric monochromators for x-ray diffraction on a synchrotron source{close_quote}{close_quote}{close_quote} [Rev. Sci. Instrum. {bold 66}, 2174 (1995)

    Energy Technology Data Exchange (ETDEWEB)

    Nave, C.; Clark, G. [Council for the Central Laboratory of the Research Councils, Daresbury Laboratory, Daresbury, Warrington WA44AD (United Kingdom); McSweeney, S. [European Molecular Biology Laboratory, 156X, 30842 Grenoble, Cedex 9 (France)

    1996-10-01

    The issue raised in Nave {ital et} {ital al}. [Rev. Sci. Instrum. {bold 66}, 2174 (1995)] is the description and results given by Sanchez del Rio and Cerrina [Nucl. Instrum. Methods A {bold 301}, 589 (1991)] and has no bearing on our understanding or otherwise of the SHADOW code (we do not refer to SHADOW in our article). The problem is whether Sanchez del Rio and Cerrina demonstrate that a demagnified image is obtained from asymmetric monochromators when operating in the white beam on a synchrotron source. {copyright} {ital 1996 American Institute of Physics.}

  16. DBS method with traditional samPling method for comParative study of human Pharmacokinetics test%DBS法与传统采样法用于人体药物代谢动力学试验的比较研究

    Institute of Scientific and Technical Information of China (English)

    倪天庆; 司端运; 胡思源; 魏广力; 夏媛媛

    2015-01-01

    Objective] Application of DBS method in Reduning injection pharmacokinetics test, and comparison of plasma collection results of traditional methods. [Methods] The elbow vein blood taken from the volunteers, some blood was quantitative analysis by LC-MS/MS quantitative analysis. We separated of the remaining blood plasma, analysis of blood drug concentration of geniposide and genipin, shanzhiside gentian diglucoside. Chromatographic column Ecosil C18 (150 mm×7.6 mm, 5μm), the mobile phase methanol, 20 mM ammonium formate, 0.1%formic acid, 10%methanol, Velocity 0.5 mL/min, sample size 10μL. Mass spectrometric detection using ESI ion source, the MRM positive ion detection mode, acquisition time of 11 min. [Results] A single intravenous infusion of Reduning injection, the blood concentration of blood cell volume determination of three kinds of gardenia component with DBS after correction, geniposide, shanzhiside, genipin gentian diglucoside in peak time (Tmax) were 1.71, 1.77, 1.77 h. The peak concentration (Cmax) were 7.580, 0.285, 0.550μg/mL. The area under the concentration time curve (AUC0-t) were 9.060, 0.638, 1.200(μg•h)/mL. The average dwell time (MRT0-t) were 1.52, 1.79, 1.75 h. [Conclusion] It is consistent of blood drug concentration and pharmacokinetic parameters about the shanzhiside, genipin gentian diglucoside plasma method and DBS method (after correction). It indicates that DBS method can replace the traditional plasma processing method in pharmacokinetic studies of drug stability ingredient.%[目的]探讨干血点采样(DBS)法在热毒宁注射液药物代谢动力学试验中的应用,并与传统的血浆采集方法结果进行比较。[方法]从志愿者肘静脉取血,一部分进行LC-MS/MS定量分析,剩余全血分离血浆,进行栀子苷、山栀苷以及京尼平龙胆双糖苷的血药浓度分析。色谱柱Ecosil C18(150 mm×7.6 mm,5μm),流动相甲醇,20 mmol/L甲酸铵,0.1%甲酸,10

  17. NoSQL Key-Value DBs Riak and Redis

    Directory of Open Access Journals (Sweden)

    Cristian Andrei BARON

    2016-05-01

    Full Text Available In the context of today's business needs we must focus on the NoSQL databases because they are the only alternative to the RDBMS that can resolve the modern problems related to storing different data structures, processing continue flows of data and fault tolerance. The object of the paper is to explain the NoSQL databases, the needs behind their appearance, the different types of NoSQL databases that current exist and to focus on two key-value databases, Riak and Redis.

  18. NoSQL Key-Value DBs Riak and Redis

    National Research Council Canada - National Science Library

    Cristian Andrei BARON

    2016-01-01

    In the context of today's business needs we must focus on the NoSQL databases because they are the only alternative to the RDBMS that can resolve the modern problems related to storing different data...

  19. Applying Genetic Algorithms to Test JUH DBs Exceptions

    Directory of Open Access Journals (Sweden)

    Mohammad Alshraideh

    2013-08-01

    Full Text Available Database represents an essential part of software applications. Many organizations use database as a repository for large amount of current and historical information. With this context testing database applications is a key issue that deserves attention. SQL Exception handling mechanism can increase the reliability of the system and improve the robustness of the software. But the exception handling code that is used to respond to exceptional conditions tends to be the source of the systems failure. It is difficult to test the exception handling by traditional methods. This paper presents a new technique that combines mutation testing and global optimization based search algorithm to test exceptions code in Jordan University Hospital (JUH database application. Thus, using mutation testing to speed the raising of exception and global optimization technique in order to automatically generate test cases, we used fitness function depends on range of data related to each query. We try to achieve the coverage of three types of PL/SQL exceptions, which are No_Data_Found (NDF, Too_Many_Rows (TMR and Others exceptions. The results show that TMR exception is not always covered this due to existence of primary key in the query, also uncovered status appear in nested exceptions.

  20. High efficiency diffraction grating for EUV lithography beamline monochromator

    Science.gov (United States)

    Voronov, D. L.; Warwick, T.; Gullikson, E. M.; Salmassi, F.; Naulleau, P.; Artemiev, N. A.; Lum, P.; Padmore, H. A.

    2016-09-01

    A blazed diffraction grating for the EUV lithography Beamline 12.0.1 of the Advanced Light Source has been fabricated using optical direct write lithography and anisotropic wet etching technology. A variable line spacing pattern was recorded on a photoresist layer and transferred to a hard mask layer of the grating substrate by a plasma etch. Then anisotropic wet etching was applied to shape triangular grating grooves with precise control of the ultralow blaze angle. Variation of the groove density along the grating length was measured with a Long Trace Profiler (LTP). Fourier analysis of the LTP data confirmed high groove placement accuracy of the grating. The grating coated with a Ru coating demonstrated diffraction efficiency of 69.6% in the negative first diffraction order which is close to theoretical efficiency at the wavelength of 13.5 nm. This work demonstrates an alternative approach to fabrication of highly efficient and precise x-ray diffraction gratings with ultra-low blaze angles.

  1. Advances on the Brazilian toroidal grating monochromator (TGM) beamline

    Energy Technology Data Exchange (ETDEWEB)

    Cavasso Filho, R.L. [Laboratorio Nacional de Luz Sincrotron, Box 6192, Campinas, SP 13084-971 (Brazil); Homem, M.G.P. [Laboratorio Nacional de Luz Sincrotron, Box 6192, Campinas, SP 13084-971 (Brazil); Landers, R. [Instituto de Fisica ' Gleb Wataghin' , Universidade Estadual de Campinas, Box 6165, Campinas, SP 13083-970 (Brazil); Naves de Brito, A. [Laboratorio Nacional de Luz Sincrotron, Box 6192, Campinas, SP 13084-971 (Brazil)]. E-mail: arnaldo@lnls.br

    2005-06-15

    We report on an important advance for the vacuum ultraviolet and soft X-ray TGM beamline at Laboratorio Nacional de Luz Sincrotron (LNLS). This beamline provides photons in the energy range 12-330 eV using three gratings. It is well known that TGMs deliver relatively high flux at these energies but harmonic contamination can be a serious problem. Of special interest for the users is the range between 12 and 21 eV covered by one of the gratings for studies of outer and inner valence ionization processes in gases as well as solids. Here, we report a solution to the harmonic contamination problems based on a noble gas phase filter combined with thin metal foil barriers.

  2. Color Restoration of Monochrome Image Formatted by Y800

    National Research Council Canada - National Science Library

    Jun Luo; Rui Su; Ying Chen

    2013-01-01

    ...) directly, we design a Bayer mode color filter array start with specific pixels to satisfy the imaging condition and then we use bilinear interpolation algorithm to restore the color of original...

  3. Applying a Trochoidal Electron Monochromator in Dissociative Electron Attachment Scattering

    Science.gov (United States)

    Arreola, Esmeralda

    2016-03-01

    Since the pioneering work of Boudiaffa et al., it has been understood that electrons, even with energies near or below the ionization threshold, are capable of initiating strand-breaks in human DNA. This discovery raised important questions for cancer treatments, since sub-ionizing electrons are known to be the most copiously produced secondary product of radiation therapy. But even to date these factors are largely excluded from dosimetry calculations. This lack of inclusion is, at least in part, certainly due to the dearth of fundamental data describing low-energy electron interactions with nucleotide molecules that form the basis of DNA. Understanding of how such slow electrons are able to damage DNA remains incomplete, but the strongly peaked nature of Boudiaffa et al.'s data gives strong hints at resonantly driven collision processes. DNA damage is therefore most likely driven by ``dissociative electron attachment'' (DEA). DEA is a rather complicated process to model due to the coupling of electronic and nuclear degrees of freedom in the molecule. At the California State University Fullerton, we are currently commissioning a new spectrometer to study dissociation channels, reaction rates and orientation effects in DEA collisions between slow electrons and nucleotide molecules. At the meeting we will present design parameters and commissioning data for this new apparatus.

  4. Consumer response to monochrome Guideline Daily Amount nutrition labels

    DEFF Research Database (Denmark)

    Boztuğ, Yasemin; Juhl, Hans Jørn; Ossama Elshiewy, Ossama x

    2015-01-01

    Front-of-pack (FOP) nutrition labelling has received extensive political attention in recent years. Most studies assessing the influence of nutrition labelling focus on consumer attention to labels, while few concentrate on its effects on actual purchase behaviour. In this study, we present results...... in terms of market share but does not affect product choice behaviour. Instead, price and habit exhibit a greater impact on purchase behaviour and product choice than the GDA label introduction....

  5. Digital halftoning methods for selectively partitioning error into achromatic and chromatic channels

    Science.gov (United States)

    Mulligan, Jeffrey B.

    1990-01-01

    A method is described for reducing the visibility of artifacts arising in the display of quantized color images on CRT displays. The method is based on the differential spatial sensitivity of the human visual system to chromatic and achromatic modulations. Because the visual system has the highest spatial and temporal acuity for the luminance component of an image, a technique which will reduce luminance artifacts at the expense of introducing high-frequency chromatic errors is sought. A method based on controlling the correlations between the quantization errors in the individual phosphor images is explored. The luminance component is greatest when the phosphor errors are positively correlated, and is minimized when the phosphor errors are negatively correlated. The greatest effect of the correlation is obtained when the intensity quantization step sizes of the individual phosphors have equal luminances. For the ordered dither algorithm, a version of the method can be implemented by simply inverting the matrix of thresholds for one of the color components.

  6. Surprising volume change in PPy(DBS): An atomic force microscopy study

    DEFF Research Database (Denmark)

    Smela, E.; Gadegaard, N.

    1999-01-01

    Communication: Conjugated polymers such as polypyrrole (PPy) have potential use as artificial muscles or in microsystems such as valves for micro-fluid handling. One of the most important parameters in such uses is the magnitude of volume change during associated redox processes; however, until now...

  7. Clapper-Yule Spectral Prediction Model of Halftone Print%Clapper-Yule光谱预测模型

    Institute of Scientific and Technical Information of China (English)

    臧冬娟; 张逸新; 刘春林

    2007-01-01

    详细介绍了经典的Clapper-Yule模型以及其改善的模型--分程Clapper-Yule模型和点扩散Clapper-Yule模型,并在此基础上介绍了Clapper-Yule模型的扩展应用:将Clapper-Yule模型扩展到粗糙承基质和荧光半色调印品上,同时分析了各个模型的特点,最后进行前景展望.

  8. [Logarithmic attachment to a monochromator for recording small changes in absorption].

    Science.gov (United States)

    Erygin, G D; Kosov, N A; Eremin, V A

    1978-01-01

    The paper describes a device consisting of a spectrophotometer (SP-4, SP-4A, SP-16), logarithmic amplifier, recording instrument and a flow-type cuvette that allows quantitative registration of biological substances during their separation on chromatographic columns.

  9. 78 FR 32424 - Notice of Issuance of Final Determination Concerning Monochrome Laser Printers

    Science.gov (United States)

    2013-05-30

    ... is the extent of the operations performed and whether the parts lose their identity and become an... minor one that leaves the identity of the imported article intact, a substantial transformation has not... incorporated into the units. The control boards were then programmed in Japan with Japanese firmware...

  10. Influence of higher harmonics of the undulator in X-ray polarimetry and crystal monochromator design.

    Science.gov (United States)

    Marx-Glowna, Berit; Schulze, Kai S; Uschmann, Ingo; Kämpfer, Tino; Weber, Günter; Hahn, Christoph; Wille, Hans Christian; Schlage, Kai; Röhlsberger, Ralf; Förster, Eckhart; Stöhlker, Thomas; Paulus, Gerhard G

    2015-09-01

    The spectrum of the undulator radiation of beamline P01 at Petra III has been measured after passing a multiple reflection channel-cut polarimeter. Odd and even harmonics up to the 15th order, as well as Compton peaks which were produced by the high harmonics in the spectrum, could been measured. These additional contributions can have a tremendous influence on the performance of the polarimeter and have to be taken into account for further polarimeter designs.

  11. Effect of Color and Monochrome Versions of a Film on Incidental and Task Relevant Learning.

    Science.gov (United States)

    Chute, Alan G.

    1980-01-01

    This study found that color in a film helped fourth- and fifth-grade students of all ability levels learn incidental information, but affected learning of task-relevant information differently depending on ability level. (Author/JEG)

  12. HORACE: Presentation-Level Protocol Standard for Digital Transmission of Monochrome Television Images

    Science.gov (United States)

    1993-11-01

    3 4.4.6 DS- 1C [Half-DS-2) (3.156 mb/s) ............ 4-3 4.4.7 DS-2 (6.312 mb/s) ........................... 4-3 4.4.8 DS-A (Two DS-2) (12.624 mb/s...skip at 15:1 or 7:1. 4.4.5 DS-1 (1.544 mb/s). Fixed or variable skip modes up to 3:1 can be used at this rate. 4.4.6 DS- 1C (Half-DS-2) (3.156 mb/sL...Rieger and Edward K. Tipler . NWC Technical Publication 5837. China Lake: NWC, October 1976. 25. - - -. - - -. Integrated Range Television System. By

  13. Performance of synchrotron X-ray monochromators under heat load Part 1 finite element modeling

    CERN Document Server

    Zhang, L; Migliore, J S; Mocella, V; Ferrero, C; Freund, A K

    2001-01-01

    In this paper we present the details of the finite element modeling (FEM) procedure used to calculate the thermal deformation generated by the X-ray power absorbed in silicon crystals. Different parameters were varied systematically such as the beam footprint on the crystal, the reflection order and the white beam slit settings. Moreover, the influence of various cooling parameters such as the cooling coefficient and the temperature of the coolant were studied. The finite element meshing was carefully optimized to generate a deformation output that could be easily read by a diffraction simulation code. Comparison with the experiments shows that the peak-to-valley slope error calculated by the FEM is an excellent approximation of the rocking curve width for a liquid nitrogen cooled silicon (3 3 3) crystal, and a quite good approximation for significantly deformed silicon (1 1 1) crystals.

  14. Long-term effects of STN DBS on mood: psychosocial profiles remain stable in a 3-year follow-up

    Directory of Open Access Journals (Sweden)

    Brücke Thomas

    2008-11-01

    Full Text Available Abstract Background Deep brain stimulation of the subthalamic nucleus significantly improves motor function in patients with severe Parkinson's disease. However, the effects on nonmotor aspects remain uncertain. The present study investigated the effects of subthalamic nucleus deep brain stimulation on mood and psychosocial functions in 33 patients with advanced Parkinson's disease in a three year follow-up. Methods Self-rating questionnaires were administered to 33 patients prior to surgery as well as three, six, twelve and 36 months after surgery. Results In the long run, motor function significantly improved after surgery. Mood and psychosocial functions transiently improved at one year but returned to baseline at 36 months after surgery. In addition, we performed cluster and discriminant function analyses and revealed four distinct psychosocial profiles, which remained relatively stable in the course of time. Two profiles featured impaired psychosocial functioning while the other two of them were characterized by greater psychosocial stability. Conclusion Compared to baseline no worsening in mood and psychosocial functions was found three years after electrode implantation. Moreover, patients can be assigned to four distinct psychosocial profiles that are relatively stable in the time course. Since these subtypes already exist preoperatively the extent of psychosocial support can be anticipatory adjusted to the patients' needs in order to enhance coping strategies and compliance. This would allow early detection and even prevention of potential psychiatric adverse events after surgery. Given adequate psychosocial support, these findings imply that patients with mild psychiatric disturbances should not be excluded from surgery.

  15. The relation of the number of hydrogen-bond acceptors with recoveries of immunosuppressants in DBS analysis

    NARCIS (Netherlands)

    Koster, Remco A.; Alffenaar, Jan-Willem C.; Botma, Rixt; Greijdanus, Ben; Uges, Donald R. A.; Kosterink, Jos G. W.; Touw, Daan J.

    2015-01-01

    BACKGROUND: We investigated the influence of the number of hydrogen-bond acceptors on the recovery of immunosuppressant drugs and their structural analogs. This hypothesis was tested by evaluation of the extraction recoveries of tacrolimus, ascomycin, sirolimus, everolimus and temsirolimus with 12,

  16. Links to Other DBs (based on UniChem) - NBDC NikkajiRDF | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available s and chemical substances registered in other databases* by using skos:closeMatch. This is based on a work a...hemical substances in other databases which were acquired using UniChem FTP service ( ftp://ftp.ebi.ac.uk/pub/databases

  17. Clapper-Yule Color Prediction Model of Recto-verso Halftone Images%半色调双面图像的色彩预测Clapper-Yule模型

    Institute of Scientific and Technical Information of China (English)

    张逸新; 臧冬娟; 葛惊寰

    2008-01-01

    为了准确地预测印刷图像的光谱反射率,在假定油墨是非散射介质以及油墨的折射率与纸张的折射率近似相等的近似下,利用考虑光在纸基内多次内反射的Clapper-Yule理论和描述多重内反射的网状结构分析模型,建立了同色不同加网周期双面墨像的光谱反射色彩预测模型.同时给出了包含纸基的向下体反射和反面纸基-空气构成界面定向反射作用的单面墨像Clapper-Yule色彩预测修正新模型.

  18. 油墨渗透下荧光半色调印刷品的预测模型%Prediction Model of Fluorescent Halftone Presswork under Ink Penetration

    Institute of Scientific and Technical Information of China (English)

    孟庆峰; 张逸新; 李中

    2008-01-01

    旨在普通油墨渗透条件下,建立能预测不同浓度的均匀荧光油墨半色调印刷品的呈色规律的理论模型;在假定油墨是非散射介质以及油墨的折射率与纸张的折射率近似相等的近似下,利用光在油墨与纸张中散射迁移路径长短不同的分程理论,建立了油墨渗透下荧光油墨半色调图像的分程Clapper-Yule光谱反射率模型.

  19. Color Prediction Model for Halftone Prints Based on Clapper-Yule Model%基于Clapper-Yule模型的半色调印品颜色预测

    Institute of Scientific and Technical Information of China (English)

    景翠宁; 张二虎

    2008-01-01

    首先详细介绍了经典的Clapper-Yule模型以及其改进模型,然后结合半色调印品对这两种模型进行了验证.实验表明:改进的Clapper-Yule模型具有较高的颜色预测精度,可以精确的预测出半色调印品的颜色,从而指导颜色工作者进行颜色参数调节,达到提高印品质量的目的.

  20. Murray-Davies Reflectance Model of Halftone Fluorescent Prints%半色调荧光油墨印刷品的Murray-Davies反射模型

    Institute of Scientific and Technical Information of China (English)

    宁元元; 张逸新; 白春燕; 秦承红

    2008-01-01

    荧光油墨防伪印刷的色彩预测是防伪印刷质量控制领域十分关心的课题.通过分析光在荧光油墨层中的传播时的吸收、散射和荧光辐射规律,分别研究油墨层中存在的3类传播光束在传播过程中的消长规律,利用反映光半色调墨层中传播规律的Murray-Davies模型,建立了半色调荧光油墨印刷品的Murray-Davies反射新模型.

  1. 基于最大后验概率的逆半调改进方法%Improved Inverse Halftoning Method via Maximum A Posteriori

    Institute of Scientific and Technical Information of China (English)

    郑海红; 曾平

    2005-01-01

    针对Bayesian算法以误差分散核为先验、时空复杂度高的缺点,提出一种逆半调改进算法. 首先根据误差分散半调图的噪声特性设计去噪预处理器,然后以预处理图像为初始值,依据最大后验概率准则,采用基于矩阵运算的迭代方法估计逆半调图像. 所构造的逆半调算法与Bayesian算法相比,逆半调图像平滑且边缘清晰,时空复杂度大大降低. 仿真结果表明:N×N维图像的空间复杂度由8N2降至81N,运行时间降为原来的15%左右;采用Floyd-Steinberg 半调图,该算法的峰值信噪比(PSNR)与小波算法相当,采用Jarvis半调图,PSNR值较小波算法提高了0.3~3 dB.

  2. New measuring concepts using integrated online analysis of color and monochrome digital high-speed camera sequences

    Science.gov (United States)

    Renz, Harald

    1997-05-01

    High speed sequences allow a subjective assessment of very fast processes and serve as an important basis for the quantitative analysis of movements. Computer systems help to acquire, handle, display and store digital image sequences as well as to perform measurement tasks automatically. High speed cameras have been used since several years for safety tests, material testing or production optimization. To get the very high speed of 1000 or more images per second, three have been used mainly 16 mm film cameras, which could provide an excellent image resolution and the required time resolution. But up to now, most results have been only judged by viewing. For some special applications like safety tests using crash or high-g sled tests in the automobile industry there have been used image analyzing techniques to measure also the characteristic of moving objects inside images. High speed films, shot during the short impact, allow judgement of the dynamic scene. Additionally they serve as an important basis for the quantitative analysis of the very fast movements. Thus exact values of the velocity and acceleration, the dummies or vehicles are exposed to, can be derived. For analysis of the sequences the positions of signalized points--mostly markers, which are fixed by the test engineers before a test--have to be measured frame by frame. The trajectories show the temporal sequence of the test objects and are the base for calibrated diagrams of distance, velocity and acceleration. Today there are replaced more and more 16 mm film cameras by electronic high speed cameras. The development of high-speed recording systems is very far advanced and the prices of these systems are more and more comparable to those of traditional film cameras. Also the resolution has been increased very greatly. The new cameras are `crashproof' and can be used for similar tasks as the 16 mm film cameras at similar sizes. High speed video cameras now offer an easy setup and direct access to digital image data. An integrated software solution (MOTION HRC ImageServer) for interfacing the camera will be presented: it controls the recording and the transfer of the images to a PC and contains tools for sequence processing, display, storage and database handling. A corresponding viewing software enables a comfortable visualization of film sequences from standard desktop pc's, replacing the presentation of 16 mm films or video tapes. The new analysis software MOTION LC was designed in cooperation with the automotive industry specially for the use with high speed video cameras. It automizes all necessary steps to measure the positions of signalled points within an image sequence and to derive calibrated trajectories. These tools now allow new integrated analyzing concept, with a very fast processing time starting with the test up to the print out of result diagrams. The system supports a lot of image sources and shows an open interface for data in- and output.

  3. Transmission Photoelectron Microscopy Of Diatoms At The Multilayer Monochromator Beamline U125-1/ML At BESSY II

    Science.gov (United States)

    Pohl, M.; Kleineberg, U.; Heinzmann, U.

    2004-05-01

    A new setup for Transmission Photoelectron Microscopy (T-PEEM) at the 3rd generation Berlin electron storage ring BESSY II is reported and initial results on imaging of dried diatom algae immobilized on a thin silicon membrane are described. The T-PEEM images recorded at a photon energy of 95 eV display a spatial resolution of better than 65 nm. Furthermore spectroscopic imaging is enabled by tuning the illuminating photon energy in the vicinity of x-ray absorption edges.

  4. High efficiency multilayer gratings for monochromators in the energy range from 500 eV to 2500 eV

    Science.gov (United States)

    Lagarde, B.; Choueikani, F.; Capitanio, B.; Ohresser, P.; Meltchakov, E.; Delmotte, F.; Krumrey, M.; Polack, F.

    2013-03-01

    Multilayer (ML) gratings have been prepared by coating shallow ion etched lamellar gratings with a Mo2C/B4C multilayer having a layer thickness close to the groove depth. It was shown that such a structure behaves as a 2D synthetic crystal and can reach very high efficiencies when the Bragg condition is satisfied. A ML coated grating has been characterized at the SOLEIL Metrology beamline between 700 and 1700 eV and a beamline of PTB at BESSY II between 1750 and 3500 eV. A peak diffraction efficiency of nearly 27 % was measured at 2200 eV. The measured efficiencies are well reproduced by numerical simulations made with the electromagnetic propagation code CARPEM, This grating will be used in the Deimos beamline at SOLEIL together with a matched multilayer mirror.

  5. Recognition of Monochrome Thermal Images of Synchronous Motor with the Application of Skeletonization and Classifier Based on Words

    Directory of Open Access Journals (Sweden)

    Glowacz A.

    2015-04-01

    Full Text Available Thermography is a technology that enables recognition of objects in the specific area. The goal of using thermographic techniques for ironworks is to diagnose electrical equipment. These techniques can be also use to increase safety and quality control in ironworks. Faulty equipment can be dangerous for engineers. Article describes the method of the recognition of imminent failure states of synchronous motor. Thermal images of the stator are used for an analysis of electrical machine. Researches of image processing techniques have been carried out for three states of motor. Proposed approach uses patterns recognition. Using of medial axis transformation and classifier based on words gave good results. In the future electrical machines and metallurgical equipment will use diagnostic systems based on recognition of thermal images.

  6. Discussion on CATV Network Company Reaction of DBS Competition%网络公司应对直播卫星竞争的几点探讨

    Institute of Scientific and Technical Information of China (English)

    杨韬

    2008-01-01

    直播卫星的成功发射,使免费收看数字电视而带来电视革命性的变化,对有线网络公司是强有力的竞争和冲击,如何应对?重点探讨阐述了网络公司有线数字电视的竞争优势及应对直播卫星竞争的办法.

  7. Development of FM screens

    Directory of Open Access Journals (Sweden)

    Ivan Pinćjer

    2012-05-01

    Full Text Available What is a satisfactory quality when it comes to graphic arts industry? Acceptable quality of halftone image is becomesame as photographic picture. There are many different ways in which one can try to reach the desired quality.Different methods of halftoning (lpi and diferent methods of forming halftone dot, scanning, prepress, platemaking are just some ways to influence the final printing result. Knowing the advantages and disadvantages of acertain halftoning technique will give us more ability to choose the right process path.

  8. 彩色半色调墨点边缘羽化的Clapper-Yule扩展模型%Extending the Clapper-Yule Spectral Reflectance Model of Color Halftone Image with the Feathering of Ink Dot Edge

    Institute of Scientific and Technical Information of China (English)

    何晓敏; 王颖; 柯能; 张逸新

    2016-01-01

    研究了墨点边缘发生羽化现象(非二值理想墨点)对印品光谱反射率的影响,为色彩预测模型的理论研究提供一个新的思路.采用二维高斯函数模拟墨点表面的形态,利用多重积分计算出墨点羽化后的体积,根据体积的恒常性即羽化前后墨点体积相等,推导出含边缘坡度因子σ的网点面积率以及含墨层相对厚度因子的油墨透射率,由此建立了一个Clapper-Yule扩展模型.模型的数值模拟结果表明墨点边缘油墨铺展所导致的网点物理扩大,增加了油墨对光的吸收,从而降低了最终的光谱反射率.采用Clapper-Yule分程模型对颜色进行预测时需考虑墨点边缘羽化所带来的物理网点扩大,该模型适用于彩色半色调印品的颜色预测与控制.

  9. Clapper-Yule Color Prediction Model for Recto-Verso Halftone Images%双面半色调图像的Clapper-Yule色彩预测分程模型

    Institute of Scientific and Technical Information of China (English)

    张逸新; 臧冬娟; 葛惊寰

    2008-01-01

    通过印刷品光谱反射比预测半色调图像色彩是印刷质量控制与设备检测研制领域十分关注的课题.在假定油墨是非散射介质以及油墨的折射率与纸张的折射率近似相等的条件下,利用光在油墨与纸张中散射迁移路径长短不同的分程理论和多重内反射的网状结构分析方法,研究了光照射在双面印刷品上的光谱反射规律,建立了双面印刷品的光谱反射色彩预测模型.并在此基础上通过理论分析,论证了新建双面印刷品的Clapper-Yule色彩分程预测模型的合理性.新模型为双面印刷品的呈色规律分析与印刷品在线检测仪的研制提供了理论依据.

  10. Clapper-Yule Spectral Color Prediction Model of Ground Color Ink Halftone Prints%具有打底油墨的半色调印刷品的Clapper-Yule模型

    Institute of Scientific and Technical Information of China (English)

    林朝荣

    2009-01-01

    通过经典的Clapper-Yule模型的应用,对已有的点对点的半色调印刷品进行扩展,在忽略油墨渗透的条件下,建立起能具有打底油墨的半色调印刷品的呈色规律的理论模型.在假定油墨是非散射介质以及油墨的折射率与纸张的折射率近似相等的近似下,利用光在油墨与纸张中散射迁移路径长短不同的分程理论,建立了具有打底油墨的半色调图像的分程Clapper-Yule光谱反射率模型.

  11. 荧光基半色调彩色图像的Clapper-Yule光学反射率%Clapper-Yule Reflectivity of Halftone Color-Imaging on Fluorescent Supports

    Institute of Scientific and Technical Information of China (English)

    张逸新; 易丽芳

    2007-01-01

    在假定成像基的吸收光谱与其荧光发射光谱不重合的近似下,采用考虑图像基多重内反射效应的半色调图像反射率预测Clapper-Yule方法研究了荧光基半色调图像的光强反射规律,得出彩色半色调图像反射率新模型.同时考虑了构成半色调图像网点的物理扩大对反射率的影响.

  12. A Theory Version of the Enhanced Clapper-Yule Model for Halftone Prints by Considering the Optical Dot Gain%考虑光学网点扩大的分程CLAPPER-YULE理论预测模型

    Institute of Scientific and Technical Information of China (English)

    何晓敏; 王颖; 柯能; 张逸新

    2015-01-01

    定量研究了半色调印刷品的光谱反射率规律.在分程Clapper-Yule光谱反射率模型的基础上,通过引入光学网点扩大参数w修正了纸张和油墨的反射率与网点面积率之间的非线性关系,建立了考虑光学网点扩大的新光谱预测模型.数值计算表明:新模型的预测值修正了原分程模型预测值低于实验值的缺陷.半色调印刷品的墨点和纸基反射率是网点面积率和光学网点扩大参数w的函数,采用分程Clapper-Yule模型预测印刷品色彩必须考虑网点面积率和参数w对反射率的影响.

  13. 双面半色调印刷品Kubelka-Munk色彩预测模型%The Color Prediction for Halftone Recto-Verso Print based on Kubelka-Munk Model

    Institute of Scientific and Technical Information of China (English)

    施国运; 董娜; 张逸新

    2009-01-01

    建立双面印刷品的色彩预测模型一直是印刷中的一个重要课题.将入射到印刷品的光根据其在垂直于印刷品中所走过的路径的不同,将其分成四大部分,即:从正面油墨进入,经过纸张,再从反面油墨出射;从正面油墨进入,从纸张出射;从正面空白区域入射,从反面油墨出射以及直接穿过纸张.所建立的相关的模型以Kubelka-Munk四能流理论为基础,通过对上述四部分的反射率与透射率相加便得到了整个双面印刷品的反射率与透射率.

  14. 基于Kubelka-Munk理论的半色调印刷品光谱反射预测模型%Spectral Reflective Prediction Model for Halftone Prints Based on Kubelka-Munk Theory

    Institute of Scientific and Technical Information of China (English)

    葛惊寰; 张逸新

    2007-01-01

    首先介绍了经典的Kubelka-Munk理论及其Saunderson校正,并在此基础上推广到半色调印刷品中,考虑到光在印刷品中的横向散射,引入了散射概率函数描述光子从一个界面元进入而从另一个界面元射出的概率,建立了一个统一的半色调印刷品光谱反射预测模型.

  15. 运用Roland彩色喷绘机制作网版印刷分色片的实验%Halftone Separating Films Output by Roland Ink-Jet Printer

    Institute of Scientific and Technical Information of China (English)

    吕砺

    2002-01-01

    介绍了使用Roland彩色喷绘机制作网印制版用的加网分色片的方法.用该方法制作的加网分色片,网点边缘清晰、密度近2.9,满足网版印刷制版要求.该技术可应用于大幅面广告招贴画的制版分色,工艺操作简单,投资及制作成本低.

  16. An Image Quality Assessment Algorithm on Color Inverse Halftoning Based on CIE DE2000 Formula%一种基于色差的逆半调图像质量评价方法

    Institute of Scientific and Technical Information of China (English)

    孔月萍; 姜楠

    2008-01-01

    鉴于CIE 1976L色差公式在小色差计算上表现出的不均匀性,将CIE DE2000色差公式与人眼视觉系统特性相结合,改进了一种基于CIE 1976L色差公式的彩色逆半调图像质量评价算法.实验验证,改进后的评价算法较原算法不仅更符合HVS特性,而且计算精度更高,生成的色差图能够比较直观、准确地反映重建图像质量.

  17. 调频网印品图像的微观色彩预测模型研究%Research of Microscopic Color Prediction Model of FM Halftone Image

    Institute of Scientific and Technical Information of China (English)

    史公程; 张逸新; 徐遵燕; 倪文虎

    2011-01-01

    在考虑网点扩大的情况下,研究了基于Murray-Davies方程的调频网半色调印品色彩预测模型.分析了调频网印品图像的微观结构和特征,建立了理想状态下调频网的反射率模型;考虑到光在纸基中的散射,采用光散射概率理论构建了墨点与墨点间的局部反射与透射关系;最后,建立了基于扩展的Murray-Davies方程的调频网半色调图像的微观色彩预测模型.

  18. No Offset Press? No Problem--Teach Duotone Production with Screen Printing

    Science.gov (United States)

    Hersey, Cara L.

    2006-01-01

    Teachers can integrate halftone or duotone production into a graphic communications class even if they lack access to an offset press. The approach described in this article, in fact, offers a benefit in that the dots involved in screen printing halftones and dutones can be enlarged to make them easily visible, while those used in offset printing…

  19. Possibilities and limitations of synchrotron X-ray powder diffraction with double crystal and double multilayer monochromators for microscopic speciation studies

    Energy Technology Data Exchange (ETDEWEB)

    De Nolf, Wout [Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610, Antwerpen (Wilrijk) (Belgium)], E-mail: wout.denolf@ua.ac.be; Jaroszewicz, Jakub [Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610, Antwerpen (Wilrijk) (Belgium); Terzano, Roberto [Dipartimento di Biologia e Chimica Agro-forestale ed Ambientale, Via Amendola 165/A, I-70126, University of Bari, Bari (Italy); Lind, Ole Christian; Salbu, Brit [Isotope Laboratory, Norwegian University of Life Sciences, PO Box 5003, N-1432 As (Norway); Vekemans, Bart [Department of Analytical Chemistry, Ghent University, Krijgslaan 281 S12, B-9000 Gent (Belgium); Janssens, Koen [Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610, Antwerpen (Wilrijk) (Belgium); Falkenberg, Gerald [HASYLAB at DESY, Beamline L, Notkestraat 85, D-22603, Hamburg (Germany)

    2009-08-15

    The performance of a combined microbeam X-ray fluorescence/X-ray powder diffraction (XRF/XRPD) measurement station at Hamburger Synchrotronstrahlungslabor (HASYLAB) Beamline L is discussed in comparison to that at European Synchrotron Radiation Facility (ESRF) ID18F/ID22. The angular resolution in the X-ray diffractograms is documented when different combinations of X-ray source, optics and X-ray diffraction detectors are employed. Typical angular resolution values in the range 0.3-0.5 deg. are obtained at the bending magnet source when a 'pink' beam form of excitation is employed. A similar setup at European Synchrotron Radiation Facility beamlines ID18F and ID22 allows to reach angular resolution values of 0.1-0.15 deg. In order to document the possibilities and limitations for speciation of metals in environmental materials by means of Hamburger Synchrotronstrahlungslabor Beamline L X-ray fluorescence/X-ray powder diffraction setup, two case studies are discussed, one involved in the identification of the crystal phases in which heavy metals such as chromium, iron, barium and lead are present in polluted soils of an industrial site (Val Basento, Italy) and another involved in the speciation of uranium in depleted uranium particles (Ceja Mountains, Kosovo). In the former case, the angular resolution is sufficient to allow identification of most crystalline phases present while in the latter case, it is necessary to dispose of an angular resolution of ca. 0.2 deg. to distinguish between different forms of oxidized uranium.

  20. Pulse-front tilt caused by the use of a grating monochromator and self-seeding of soft X-ray FELs

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2012-01-01

    Self-seeding is a promising approach to significantly narrow the SASE bandwidth of XFELs to produce nearly transform-limited pulses. The development of such schemes in the soft X-ray wavelength range necessarily involves gratings as dispersive elements. These introduce, in general, a pulse-front tilt, which is directly proportional to the angular dispersion. Pulse-front tilt may easily lead to a seed signal decrease by a factor two or more. Suggestions on how to minimize the pulse-front tilt effect in the self-seeding setup are given.

  1. A novel generalized DCT-based JND profile based on an elaborate CM-JND model for variable block-sized transforms in monochrome images.

    Science.gov (United States)

    Bae, Sung-Ho; Kim, Munchurl

    2014-08-01

    In this paper, we propose a new DCT-based just noticeable difference (JND) profile incorporating the spatial contrast sensitivity function, the luminance adaptation effect, and the contrast masking (CM) effect. The proposed JND profile overcomes two limitations of conventional JND profiles: 1) the CM JND models in the conventional JND profiles employed simple texture complexity metrics, which are not often highly correlated with perceived complexity, especially for unstructured patterns. So, we proposed a new texture complexity metric that considers not only contrast intensity, but also structureness of image patterns, called the structural contrast index. We also newly found out that, as the structural contrast index of a background texture pattern increases, the modulation factors for CM-JND show a bandpass property in frequency. Based on this observation, a new CM-JND is modeled as a function of DCT frequency and the proposed structural contrast index, showing significantly high correlations with measured CM-JND values and 2) while the conventional DCT-based JND profiles are only applicable for specific transform block sizes, our proposed DCT-based JND profile is first designed to be applicable to any size of transform by deriving a new summation effect function, which can also be appropriately applied for quad-tree transform of high efficiency video coding. For the overall performance, the proposed DCT-based JND profile shows more tolerance for distortions with better perceptual quality than other JND profiles under comparison.

  2. High Precision, Absolute Total Column Ozone Measurements from the Pandora Spectrometer System: Comparisons with Data from a Brewer Double Monochromator and Aura OMI

    Science.gov (United States)

    Tzortziou, Maria A.; Herman, Jay R.; Cede, Alexander; Abuhassan, Nader

    2012-01-01

    We present new, high precision, high temporal resolution measurements of total column ozone (TCO) amounts derived from ground-based direct-sun irradiance measurements using our recently deployed Pandora single-grating spectrometers. Pandora's small size and portability allow deployment at multiple sites within an urban air-shed and development of a ground-based monitoring network for studying small-scale atmospheric dynamics, spatial heterogeneities in trace gas distribution, local pollution conditions, photochemical processes and interdependencies of ozone and its major precursors. Results are shown for four mid- to high-latitude sites where different Pandora instruments were used. Comparisons with a well calibrated double-grating Brewer spectrometer over a period of more than a year in Greenbelt MD showed excellent agreement and a small bias of approximately 2 DU (or, 0.6%). This was constant with slant column ozone amount over the full range of observed solar zenith angles (15-80), indicating adequate Pandora stray light correction. A small (1-2%) seasonal difference was found, consistent with sensitivity studies showing that the Pandora spectral fitting TCO retrieval has a temperature dependence of 1% per 3K, with an underestimation in temperature (e.g., during summer) resulting in an underestimation of TCO. Pandora agreed well with Aura-OMI (Ozone Measuring Instrument) satellite data, with average residuals of <1% at the different sites when the OMI view was within 50 km from the Pandora location and OMI-measured cloud fraction was <0.2. The frequent and continuous measurements by Pandora revealed significant short-term (hourly) temporal changes in TCO, not possible to capture by sun-synchronous satellites, such as OMI, alone.

  3. Text And Graphics Electronic Processing For The Printing-Publishing Industry

    Science.gov (United States)

    Harris, Barry V.

    1980-08-01

    In 1880, Stephen Horgan introduced a new dimension to the world of printing when under his direction the first published halftone, named "Shantytown", appeared on the front page of the New York Daily Graphic,.

  4. A complete manual of amateur astronomy tools and techniques for astronomical observations

    CERN Document Server

    Sherrod, P Clay

    2003-01-01

    Concise, highly readable book discusses the selection, set-up, and maintenance of a telescope; amateur studies of the sun; lunar topography and occultations; and more. 124 figures. 26 halftones. 37 tables.

  5. [Book review] Skua and penguin: Predator and prey, by Euan Young

    Science.gov (United States)

    Pietz, P.J.

    1995-01-01

    Review of: Skua and Penguin: Predator and Prey. Euan Young. 1994. Cambridge University Press, Cambridge, United Kingdom. xvi + 452 pp., 53 line diagrams, 44 half-tones. ISBN 0-521-32251-0. $99.95 cloth

  6. Post-mortem Findings in Huntington’s Deep Brain Stimulation: A Moving Target Due to Atrophy

    Science.gov (United States)

    Vedam-Mai, Vinata; Martinez-Ramirez, Daniel; Hilliard, Justin D.; Carbunaru, Samuel; Yachnis, Anthony T.; Bloom, Joshua; Keeling, Peyton; Awe, Lisa; Foote, Kelly D.; Okun, Michael S.

    2016-01-01

    Background Deep brain stimulation (DBS) has been shown to be effective for Parkinson’s disease, essential tremor, and primary dystonia. However, mixed results have been reported in Huntington’s disease (HD). Case Report A single case of HD DBS was identified from the University of Florida DBS Brain Tissue Network. The clinical presentation, evolution, surgical planning, DBS parameters, clinical outcomes, and brain pathological changes are summarized. Discussion This case of HD DBS revealed that chorea may improve and be sustained. Minimal histopathological changes were noted around the DBS leads. Severe atrophy due to HD likely changed the DBS lead position relative to the internal capsule. PMID:27127722

  7. Disparate detection outcomes for anti-HCV IgG and HCV RNA in dried blood spots.

    Science.gov (United States)

    Tejada-Strop, Alexandra; Drobeniuc, Jan; Mixson-Hayden, Tonya; Forbi, Joseph C; Le, Ngoc-Thao; Li, Lixia; Mei, Joanne; Terrault, Norah; Kamili, Saleem

    2015-02-01

    Dried blood spots (DBS) expedite the collection, storage and shipping of blood samples, thereby facilitating large-scale serologic studies. We evaluated the sensitivity of anti-HCV IgG testing and HCV-RNA quantitation using freshly prepared and stored DBS derived from HCV-infected patients. Protocols for elution were optimized using DBS prepared from plasma of 52 HCV-infected persons and 51 uninfected persons (control DBS), then applied to DBS from 33 chronic hepatitis C patients that had been stored at -20°C for 5 years (stored DBS). Control and stored DBS, and their corresponding plasma, were processed for anti-HCV IgG testing using the VITROS chemiluminescence assay (CIA) and the HCV 3.0 enzyme immunoassay (EIA) (Ortho-Clinical Diagnostics), and for HCV RNA quantitation by quantitative (q) RT-PCR. HCV genotyping was conducted by nucleotide sequencing. The sensitivity of CIA and EIA in control DBS was 92% and 90%, respectively, compared to 100% and 97%, respectively, in stored DBS. The sensitivity of HCV RNA detection was 88% in control DBS, compared to 36% in stored DBS. Specificity was 100% for all the assays in both control and stored DBS. Genotypes 1, 2 and 3 were detected in 16 (62%), 6 (23.1%), and 4 (15.3%) samples, respectively. Sequences generated from DBS and their corresponding plasma samples were identical. Whereas the sensitivity of anti-HCV IgG detection in stored DBS was equivalent to that in recently prepared DBS, the sensitivity of HCV RNA detection was markedly lower in stored DBS compared to recently prepared DBS. Stored DBS may be reliably used for anti-HCV detection but for HCV-RNA-based testing freshly prepared DBS is preferable to stored DBS.

  8. AcEST: BP917757 [AcEST

    Lifescience Database Archive (English)

    Full Text Available 1|A0DBS1_PARTE Chromosome undetermined scaffold_44, whole genome shotgun sequence OS=Paramecium tetraurelia ...ing significant alignments: (bits) Value tr|A0DBS1|A0DBS1_PARTE Chromosome undetermined scaffold_44, whol...... 33 9.2 >tr|A0DBS1|A0DBS1_PARTE Chromosome undetermined scaffold_44, whole genome shotgun sequence OS=Parame

  9. 基于虚拟仪器的彩色图像单色背景透明化处理%The transparent treatment research of color image with monochrome background which is based on the virtual instrument

    Institute of Scientific and Technical Information of China (English)

    陈晓龙; 陈万培; 刘时; 范冠杰

    2012-01-01

    In the application of synthetic images,it is necessary to achieve local transparent image processing. This thesis describes a method of image processing with the background color of monochromatic characters which is based on the virtual instrument technology. Decomposing every pixel of the color image into the red,green,blue three colors and then compare that with the extraction of characteristic points. And structuring new image mask by a new processing method of each pixel to achieve the purpose of the reconstruction of the original image, consequently finishing the background transparent process of the original color images. This method can be used to the image processing with relatively single background color and the characters of the big color difference . It works good.%在图片的合成应用中需要对图片进行局部的透明化处理.提出了通过虚拟仪器技术,对具有单色背景的彩色人物图像进行处理的一种算法研究.通过将彩色图像的每个像素点分解成RGB三基色后与提取的特征点比对,对每个像素点灰度值运算构建新的图像掩码集,来重构原图像,完成对原彩色图像背景的透明化处理过程.该方法可以应用与背景颜色较为单一并且与人物图像颜色差异性大的图片处理,效果显著.

  10. Disposal of metal artifacts by monochrome virtual images generated by TC dual power planning in radiation therapy; Eliminacion de artefactos metalicos mediante imagenes virtuales nonocromaticas generadas mediante TC de energia dual para planificacion en radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Perez, V.; Bartres Salido, A.; Arana Fernandez Moya, E.; Crispin Contreras, V.; Dolores Alemany, V. de los; Campo Sanmartin, V.; Moratal Perez, D.

    2015-07-01

    Using monochromatic high-energy virtual images reconstructed by a scanner TCED is viable for planning radiotherapy treatments and improves image quality. Such images using the DICOM standard, and have been successfully exported to the planning system XiO treatments. (Author)

  11. Simulation and Comparison of General Focusing Monochromators for Neutron Diffractometer for Stress Measurement%中子应力谱仪常用聚焦单色器的模拟与比较

    Institute of Scientific and Technical Information of China (English)

    陈华; 黄朝强; 孙光爱; 陈波

    2010-01-01

    用蒙特卡罗中子射线追踪程序McStas对中子衍射应力谱仪单色器部件进行模拟优化:以Cu(220)比较了单色器起飞角和准直系统对样品处中子注量率、分辨率的影响;计算得到给定条件下单色器最佳单晶条数和镶嵌度;单晶条倾角精度建议好于0.1°;计算了Cu(222)、(220)和(002)在不同起飞角情况下获得的中子注量率;相同条件下,Cu和Ge常用晶体单色器中以Cu(220)获得的中子注量率最大,而Cu(222)获得的波长分辨率最佳.

  12. 应力测量中子衍射谱仪聚焦单色器的模拟%Simulation Study on Focused Monochromator of Neutron Diffractometer for Stress Measurement

    Institute of Scientific and Technical Information of China (English)

    郭立平; 李际周; 孙凯; 李峻宏; 陈东风

    2008-01-01

    为提高样品处入射中子束强度,满足高分辨和小体积标样测量的需要,应用MCSTAS软件对中国先进研究堆上应力测量中子衍射谱仪的核心部件垂直聚焦单色器进行模拟和优化设计,得到了单色器在不同起飞角下的最佳聚焦条件,即所需的曲率半径和相邻单晶条之间的最佳倾角.在此条件下,可获得相对于平板单色器6~7倍的强度增益,样品处中子注量率达10 7 cm -2 ·s -1 以上.在使用聚焦单色器的情形下,对标准的α-Fe多晶样品在无应变、拉应变和压应变下的(211)衍射峰进行了模拟.结果表明:该谱仪的分辨水平至少能测量500 με以上的应变,且应变测量最高精度约为20 με.

  13. 中子衍射应力谱仪垂直聚焦单色器的优化设计%Optimal simulation of vertical monochromator of neutron diffraction residual stress instrument

    Institute of Scientific and Technical Information of China (English)

    王晓影; 李建; 谢超美; 刘荣

    2008-01-01

    为提高应力谱仪样品处的中子注量率,对垂直聚焦单色器进行了优化设计.应用蒙特卡罗模拟程序MCSTAS对中子衍射应力谱仪的垂直聚焦Ge(511)单色器进行优化计算,得到了垂直聚焦单色器的高度与单晶片之间的倾角等参数的最佳值.然后,对比分析了在垂直聚焦单色器与平板单色器两种情况下样品处的中子注量率.最后,讨论了单色器起飞角对谱仪分辨率的影响.计算结果表明:单色器尺寸为50 mm×150 mm;垂直单色器在样品台中心位置的中子注入量是平板单色器的4.99倍,表明利用垂直单色器可以显著提高应力谱仪样品处的中子注量率.

  14. Clapper-Yule Front Reflectance Model of for Recto-verso Halftone Image Printed on Fluorescent Paper Substrate%荧光纸基的双面彩色半色调印刷品Clapper-Yule正面反射率模型

    Institute of Scientific and Technical Information of China (English)

    王颖; 柯能; 何晓敏; 张逸新

    2015-01-01

    目的 研究荧光纸基对双面彩色半色调印刷品反射率的影响.方法 假设油墨与纸张的折射率相似,考虑到荧光部分可以吸收光线中不可见的紫外光,经过能量转换散发出可见光从而影响总反射率,将这部分影响等效于正、反面油墨的透射率,以及纸张内部向正、反面反射率的改变;考虑光学网点扩大因子,利用Clapper-Yule分程理论进行分析;通过数值模拟,对新、旧模型进行比较,验证新模型的合理性和准确性.结果 建立了荧光纸基的双面彩色半色调印刷品Clapper-Yule正面反射率模型.结论 色彩预测Clapper-Yule反射率模型必须考虑荧光纸基的影响.

  15. Tailored deep brain stimulation optimization for improved airway protective outcomes in Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Michelle S. Troche

    2016-09-01

    Full Text Available There is no consensus regarding the effects of deep brain stimulation (DBS surgery on swallowing outcomes in Parkinson's disease (PD. No prospective studies have compared airway protective outcomes following DBS to the subthalamic nucleus (STN versus globus pallidus interna (GPi. A recent retrospective study described swallowing outcomes pre- and post-STN vs. GPi DBS in a cohort of 34 patients with PD. The results revealed that the patients who received GPi DBS maintained their swallowing function post-DBS, while those in the STN group significantly worsened in swallowing safety. As DBS surgery becomes a common management option in PD it is important to understand the impact of DBS on airway protective outcomes; especially given that aspiration pneumonia is the leading cause of death in this population. We present a case report in which optimizing DBS settings with the goal of improving laryngeal function resulted in immediate improvements to swallowing safety.

  16. Strong Correlation Between Concentrations of Tenofovir (TFV) Emtricitabine (FTC) in Hair and TFV Diphosphate and FTC Triphosphate in Dried Blood Spots in the iPrEx Open Label Extension: Implications for Pre-exposure Prophylaxis Adherence Monitoring.

    Science.gov (United States)

    Gandhi, Monica; Glidden, David V; Liu, Albert; Anderson, Peter L; Horng, Howard; Defechereux, Patricia; Guanira, Juan V; Grinsztejn, Beatriz; Chariyalertsak, Suwat; Bekker, Linda-Gail; Grant, Robert M

    2015-11-01

    Self-reported adherence to pre-exposure prophylaxis (PrEP) has limitations, raising interest in pharmacologic monitoring. Drug concentrations in hair and dried blood spots (DBS) are used to assess long-term-exposure; hair shipment/storage occurs at room temperature. The iPrEx Open Label Extension collected DBS routinely, with opt-in hair collection; concentrations were measured with liquid chromatography/tandem mass spectrometry. In 806 hair-DBS pairs, tenofovir (TFV) hair levels and TFV diphosphate (DP) in DBS were strongly correlated (Spearman coefficient r = 0.734; P hair TFV/DBS emtricitabine (FTC) triphosphate (TP) (r = 0.781; P hair FTC/DBS TFV-DP (r = 0.74; P hair FTC/DBS FTC-TP (r = 0.587; P Hair TFV/FTC concentrations correlate strongly with DBS levels, which are predictive of PrEP outcomes.

  17. Satellite Communications Industry

    Science.gov (United States)

    1993-04-01

    LDBS 1 Loral Local-DBS /95 LDBS 2 Loral Local-DBS /96 LDBS 3 Loral Local-DBS /97 ".ASAT Hughes Bina Riang ( Malaysia )/95 Ariane $25m .xico (DBS) GE SCT...loom SatcomC3 GE GE Americom 09/92 Ariane $50m HISPASAT 1A Matra Spain 09/92 Ariane DFSKopernikus GESAT/Siemens/MBB DBP Telekom 10/92 MDSSC Galaxy 7

  18. Stability of dried blood spots for HIV-1 drug resistance analysis.

    Science.gov (United States)

    Hearps, Anna C; Ryan, Claire E; Morris, Lisa M; Plate, Megan M; Greengrass, Vicki; Crowe, Suzanne M

    2010-03-01

    The wide scale application of dried blood spots (DBS) as a collection tool for low-cost HIV drug resistance testing requires a greater understanding of the accuracy of DBS for genotype analysis and the stability of DBS under various environmental conditions. Analysis of a 50microl DBS via a single amplicon, nested PCR-based in-house assay (the Burnet genotyping assay) showed an average nucleotide concordance of 98.9% with plasma samples, although only 65% of nucleotide mixtures detected in plasma were also detected within DBS. The analysis of three DBS resulted in the detection of a greater number of nucleotide mixtures (72 and 109 mixtures detected within one and three DBS, respectively, n=10). Two DBS extraction protocols (silica particle; NucliSENS, bioMerieux and spin column extraction; High Pure, Roche) were assessed and found to be equivalent (79% and 84% recovery success respectively, n=19). FTA Elute paper (Whatman) was an inferior DBS collection medium compared to Whatman 903 paper. DBS appeared relatively tolerant to multiple freeze/thaw cycles, with 79% of DBS subjected to ten freeze/thaw cycles successfully amplified compared to 93% of DBS defrosted once (n=14). High temperature (37 degrees C) and high humidity (>90%) substantially impaired DBS recovery within two weeks of storage (38%, n=8), whilst storage at -20 degrees C or 4 degrees C adequately preserved DBS for this period (100% recovery, n=8). Therefore, whilst DBS are suitable for HIV drug resistance surveillance, the use of multiple DBS may be required to ensure accurate detection of minor HIV quasispecies and short-term storage of samples at either 4 degrees C or -20 degrees C is recommended.

  19. Laser cutting eliminates nucleic acid cross-contamination in dried-blood-spot processing.

    Science.gov (United States)

    Murphy, Sean C; Daza, Glenda; Chang, Ming; Coombs, Robert

    2012-12-01

    Dried blood spots (DBS) are useful for molecular assays but are prone to false positives from cross-contamination. In our malaria DBS assay, cross-contamination was encountered despite cleaning techniques suitable for HIV-1. We therefore developed a contact-free laser cutting system that effectively eliminated cross-contamination during DBS processing.

  20. Bilateral adaptive deep brain stimulation is effective in Parkinson's disease

    NARCIS (Netherlands)

    Little, Simon; Beudel, Martijn; Zrinzo, Ludvic; Foltynie, Thomas; Limousin, Patricia; Hariz, Marwan; Neal, Spencer; Cheeran, Binith; Cagnan, Hayriye; Gratwicke, James; Aziz, Tipu Z.; Pogosyan, Alex; Brown, Peter

    2016-01-01

    Introduction & objectives Adaptive deep brain stimulation (aDBS) uses feedback from brain signals to guide stimulation. A recent acute trial of unilateral aDBS showed that aDBS can lead to substantial improvements in contralateral hemibody Unified Parkinson's Disease Rating Scale (UPDRS) motor score

  1. IDENTIFICATION OF APPROPRIATE QUALIFICATION TESTING AND END-OF-LIFE WASTE STORAGE CONSIDERATIONS FOR DEEP BED SAND FILTERS

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, K.

    2010-06-02

    Deep bed sand (DBS) filters have filtered radioactive particulates at two United States Department of Energy (DOE) sites since 1948. Some early DBS filters experienced issues with chemical attack on support tiles, requiring significant repairs. Designs of DBS filters constructed since 1970 paid greater attention to chemical compatibility, resulting in decades of reliable performance since 1975.

  2. Dried blood spot analysis of creatinine with LC-MS/MS in addition to immunosuppressants analysis

    NARCIS (Netherlands)

    Koster, Remco A.; Greijdanus, Ben; Alffenaar, Jan-Willem C.; Touw, Daan J.

    2015-01-01

    In order to monitor creatinine levels or to adjust the dosage of renally excreted or nephrotoxic drugs, the analysis of creatinine in dried blood spots (DBS) could be a useful addition to DBS analysis. We developed a LC-MS/MS method for the analysis of creatinine in the same DBS extract that was use

  3. Olfactory Functioning in Parkinson's Disease: The Effects of Deep Brain Stimulation

    DEFF Research Database (Denmark)

    van Hartevelt, Tim Johannes

    2014-01-01

    the long-term effects of DBS for PD are investigated. The results show that after five months of continuous DBS, olfactory areas known to be affected in PD show significant structural changes. The fourth study uses advanced whole-brain computational modeling to uncover the mechanisms of continuous DBS...

  4. Suppression of hippocampal epileptic seizures in the kainate rat by Poisson distributed stimulation

    NARCIS (Netherlands)

    Wyckhuys, T.; Boon, P.; Raedt, R.; Van Nieuwenhuyse, B.; Vonck, K.; Wadman, W.

    2010-01-01

    Purpose:  Hippocampal deep brain stimulation (DBS) is an experimental therapy for patients with pharmacoresistant temporal lobe epilepsy (TLE). Despite the successful clinical application of DBS, the optimal stimulation parameters are undetermined. We evaluate the efficacy of a new form of DBS, usin

  5. Digital grayscale printing for patterned transparent conducting Ag electrodes and their applications in flexible electronics

    DEFF Research Database (Denmark)

    Gupta, Ritu; Hösel, Markus; Jensen, Jacob

    2014-01-01

    Grayscale (halftone) laser printing is developed as a low-cost and solution processable fabrication method for ITO-free, semi-transparent and conducting Ag electrodes extendable over large area on a flexible substrate. The transmittance and sheet resistance is easily tunable by varying the graysc......Grayscale (halftone) laser printing is developed as a low-cost and solution processable fabrication method for ITO-free, semi-transparent and conducting Ag electrodes extendable over large area on a flexible substrate. The transmittance and sheet resistance is easily tunable by varying...

  6. Una solución paralela simple al método de difusión de error

    OpenAIRE

    Abdala, G.; Guerrero, Roberto A.; Piccoli, María Fabiana

    2006-01-01

    El Halftoning o Mediotonado Digital se utiliza para plasmar imágenes en escala de grises en dispositivos electrónicos que sólo pueden reproducir elementos binarios creando la ilusión de tonos continuo. A pesar de los numerosos métodos de halftoning existentes, todos ellos comparten la problemática de que su tiempo de procesamiento es dependiente de las características de la imagen y el algoritmo utilizado. Es de interés la generación de propuestas para acelerar los tiempos de procesamiento...

  7. Facilitating effects of deep brain stimulation on feedback learning in Parkinson's disease.

    Science.gov (United States)

    Meissner, Sarah Nadine; Südmeyer, Martin; Keitel, Ariane; Pollok, Bettina; Bellebaum, Christian

    2016-10-15

    Deep brain stimulation (DBS) of the subthalamic nucleus (STN) provides an effective treatment for Parkinson's disease (PD) motor symptoms. However, findings of effects on cognitive function such as feedback learning remain controversial and rare. The aim of the present study was to gain a better understanding of cognitive alterations associated with STN-DBS. Therefore, we investigated effects of STN-DBS on active and observational feedback learning in PD. 18 PD patients with STN-DBS and 18 matched healthy controls completed active and observational feedback learning tasks. Patients were investigated ON and OFF STN-DBS. Tasks consisted of learning (with feedback) and test phases (without feedback). STN-DBS improved active learning during feedback trials and PD patients ON (but not OFF) STN-DBS showed comparable performance patterns as healthy controls. No STN-DBS effect was found when assessing performance during active test trials without feedback. In this case, however, STN-DBS effects were found to depend on symptom severity. While more impaired patients benefited from STN-DBS, stimulation had no facilitating effect on patients with less severe symptoms. Along similar lines, the severity of motor symptoms tended to be significantly correlated with differences in active test performance due to STN-DBS. For observational feedback learning, there was a tendency for a positive STN-DBS effect with patients reaching the performance level of healthy controls only ON STN-DBS. The present data suggest that STN-DBS facilitates active feedback learning in PD patients. Furthermore, they provide first evidence that STN-DBS might not only affect learning from own but also from observed actions and outcomes.

  8. Efeito da estimulação cerebral profunda (DBS) no comportamento de camundongos, após lesão unilateral do feixe prosencefálico medial com 6-hidroxidopamina (6-OHDA), como modelo animal da doença de parkinson

    OpenAIRE

    Araujo, Ricardo Saravy de

    2016-01-01

    A doença de Parkinson (DP) é primariamente uma doença da função motora extrapiramidal, causada por degeneração severa de neurônios dopaminérgicos da substância negra. O tratamento sintomático da DP com L-dopa e drogas agonistas de dopamina predominam a terapia desta doença, e elas são altamente efetivas em tratar os estágios iniciais da doença. Todavia, a introdução de drogas dopaminérgicas está associada com efeitos colaterais agudos. Mais recentemente, a eletroestimulação cerebral vem sendo...

  9. Evaluation of the human immunodeficiency virus type 1 and 2 antibodies detection in dried whole blood spots (dbs samples Pesquisa de anticorpos contra o vírus da imunodeficiência humana tipos 1 e 2 em amostras de sangue seco coletadas em papel filtro

    Directory of Open Access Journals (Sweden)

    Andréa Cauduro de Castro

    2008-06-01

    Full Text Available Human Immunodeficiency Vírus Type 1 and 2 antibodies detection was performed in 457 dried whole blood spots samples (S&S 903. Q-Preven HIV 1+2 was the screening test used. The results were compared with the gold standard serum tests by ELISA (Cobas Core e Axsym HIV1/2 gO and imunofluorescence was the definitive confirmatory test. The samples were obtained from the Hospital Nossa Senhora da Conceição in Porto Alegre, RS - Brazil, through whole blood transfer to filter paper card and sent to Caxias do Sul, RS - Brazil where the tests were performed. The dried whole blood spot stability was evaluated with two different panels. The first one was composed of five negative and five positive samples stored at room temperature, 4 ºC, -20 ºC and -70 ºC, while the second was composed of two negative and three positive samples stored at 37 ºC (humidity Foram realizados 457 testes para detectar anticorpos contra o Vírus da Imunodeficiência Humana tipos 1 e 2, em amostras de sangue total seco coletadas em papel filtro (S&S 903, com o teste de triagem Q-Preven HIV 1+2, comparando-se com os resultados dos testes de triagem no soro (Cobas Core e Axsym HIV1/2 gO, sendo a imunofluorescência indireta o teste confirmatório. As amostras foram obtidas no Hospital Conceição em Porto Alegre, pela transferência de sangue total para cartão de papel filtro e encaminhadas para Caxias do Sul para a realização dos testes. Foi analisada a estabilidade da amostra em papel filtro com a utilização de dois painéis: o primeiro com cinco amostras negativas e cinco positivas armazenadas por seis semanas à temperatura ambiente, 4 ºC, -20 ºC e -70 ºC; o segundo com duas negativas e três positivas armazenadas por seis semanas com avaliações semanais a 37 ºC (umidade <50%. Os resultados de todas as amostras testadas foram mantidos. A sensibilidade foi de 100%, a especificidade de 99,6%, o valor preditivo positivo de 99,5% e o valor preditivo negativo de 100%. O excelente desempenho observado na análise da utilização de sangue seco em papel filtro, abre uma nova perspectiva no diagnóstico da infecção pelo HIV.

  10. Dried blood spots for the diagnosis and quantitation of HIV-1: stability studies and evaluation of sensitivity and specificity for the diagnosis of infant HIV-1 infection in Thailand.

    Science.gov (United States)

    Leelawiwat, W; Young, N L; Chaowanachan, T; Ou, C Y; Culnane, M; Vanprapa, N; Waranawat, N; Wasinrapee, P; Mock, P A; Tappero, J; McNicholl, J M

    2009-02-01

    Molecular methods for HIV-1 infection using dried blood-spot (DBS) for HIV-1 CRF01_AE subtypes have not been fully optimized. In this study assays for HIV-1 diagnosis or quantitation were evaluated using infant DBS from Thailand. Paired DBS and whole blood samples from 56 HIV-1 CRF01_AE or B'-infected infants were tested for infant diagnosis using modified Amplicor DNA PCR and NucliSens RNA NASBA and an in-house real-time PCR assay. The Amplicor Monitor viral load (VL) assay, with modifications for DBS, was also evaluated. DBS VL were hematocrit corrected. Stability studies were done on DBS stored at -70 degrees C to 37 degrees C for up to 1 year. The DBS diagnostic assays were 96-100% sensitive and 100% specific for HIV-1 diagnosis. DBS HIV-1 VL were highly correlated with plasma VL when corrected using the actual or an assumed hematocrit factor (r(c)=0.88 or 0.93, respectively). HIV-1 DNA in DBS appeared to be more stable than RNA and could be detected after up to 9 months at most temperatures. DBS VL could be consistently determined when stored frozen. These results show that DBS can be used accurately instead of whole blood for the diagnosis of HIV-1 infection and VL quantitation, particularly if samples are appropriately stored.

  11. Organogel Formation Due to the Self-Assembly of Dibenzylidene Sorbitol

    Science.gov (United States)

    Wilder, Elizabeth; Hall, Carol; Khan, Saad; Spontak, Richard

    2002-03-01

    Dibenzylidene sorbitol (DBS) is a small organic molecule that is capable of inducing gelation in a variety of organic solvents and polymers at low concentrations. In this study, a combination of rheological studies, electron microscopy, and computational methods were employed to probe the mechanisms involved in DBS-induced gelation. Rheological tests on DBS/poly(ethylene glycol) (PEG) gels reveal that as DBS concentration is increased, the gels exhibit greater elastic moduli, shorter gelation times, and maintain their connectivity at higher temperatures. Comparison of methoxy-capped PEG gels with hydroxy-capped PEG gels reveals that polar end groups interfere with network formation resulting in slower gelation times. Electron microscopy and tomography on DBS networks in poly(ethyl methacrylate) show that at low concentrations, DBS associates into small aggregates, while at higher concentrations fibrillar growth is evident. Molecular mechanical energy calculations suggest that DBS networks may form through a combination of intermolecular hydrogen bonding and pi-interactions.

  12. State of the Art for Deep Brain Stimulation Therapy in Movement Disorders: A Clinical and Technological Perspective.

    Science.gov (United States)

    Wagle Shukla, Aparna; Okun, Michael S

    2016-01-01

    Deep brain stimulation (DBS) therapy is a widely used brain surgery that can be applied for many neurological and psychiatric disorders. DBS is American Food and Drug Administration approved for medication refractory Parkinson's disease, essential tremor and dystonia. Although DBS has shown consistent success in many clinical trials, the therapy has limitations and there are well-recognized complications. Thus, only carefully selected patients are ideal candidates for this surgery. Over the last two decades, there have been significant advances in clinical knowledge on DBS. In addition, the surgical techniques and technology related to DBS has been rapidly evolving. The goal of this review is to describe the current status of DBS in the context of movement disorders, outline the mechanisms of action for DBS in brief, discuss the standard surgical and imaging techniques, discuss the patient selection and clinical outcomes in each of the movement disorders, and finally, introduce the recent advancements from a clinical and technological perspective.

  13. Deep brain stimulation reveals a dissociation of consummatory and motivated behaviour in the medial and lateral nucleus accumbens shell of the rat.

    Directory of Open Access Journals (Sweden)

    Geoffrey van der Plasse

    Full Text Available Following the successful application of deep brain stimulation (DBS in the treatment of Parkinson's disease and promising results in clinical trials for obsessive compulsive disorder and major depression, DBS is currently being tested in small patient-populations with eating disorders and addiction. However, in spite of its potential use in a broad spectrum of disorders, the mechanisms of action of DBS remain largely unclear and optimal neural targets for stimulation in several disorders have yet to be established. Thus, there is a great need to examine site-specific effects of DBS on a behavioural level and to understand how DBS may modulate pathological behaviour. In view of the possible application of DBS in the treatment of disorders characterized by impaired processing of reward and motivation, like addiction and eating disorders, we examined the effect of DBS of the nucleus accumbens (NAcc on food-directed behavior. Rats were implanted with bilateral stimulation electrodes in one of three anatomically and functionally distinct sub-areas of the NAcc: the core, lateral shell (lShell and medial shell (mShell. Subsequently, we studied the effects of DBS on food consumption, and the motivational and appetitive properties of food. The data revealed a functional dissociation between the lShell and mShell. DBS of the lShell reduced motivation to respond for sucrose under a progressive ratio schedule of reinforcement, mShell DBS, however, profoundly and selectively increased the intake of chow. DBS of the NAcc core did not alter any form of food-directed behavior studied. DBS of neither structure affected sucrose preference. These data indicate that the intake of chow and the motivation to work for palatable food can independently be modulated by DBS of subregions of the NAcc shell. As such, these findings provide important leads for the possible future application of DBS as a treatment for eating disorders such as anorexia nervosa.

  14. Color Reproduction System Based on Color Appearance Model and Gamut Mapping

    Science.gov (United States)

    2000-07-01

    perception is usually different. Basically, the influence factors are device calibration and characterization, viewing condition, device gamut and human...Halftone Reproduction", TAGA Proceedings, 65-76 [7] R. W. G. Hunt, "The Reproduction of Color in Photography, Printing, & Televison ". FOUNTAIN PRESS, 4 ed

  15. Trying Leviathan: The Nineteenth-Century New York Court Case that Put the Whale and Challenged the Order of Nature

    Directory of Open Access Journals (Sweden)

    E. N. Anderson

    2010-08-01

    Full Text Available Review of Trying Leviathan: The Nineteenth-Century New York Court Case that Put the Whale and Challenged the Order of Nature. D. Graham Burnett. 2007. Princeton University Press. Pp. 304 color plates, halftones, bibliography, index. $29.95(cloth. ISBN 9780691129501.

  16. Temporary deep brain stimulation in Gilles de la Tourette syndrome: A feasible approach?

    Science.gov (United States)

    Zekaj, Edvin; Saleh, Christian; Porta, Mauro; Servello, Domenico

    2015-01-01

    Background: Gilles de la Tourette Syndrome (GTS) is a complex neuropsychiatric disorder, characterized by chronic motor and vocal tics, associated in 50–90% of cases with psychiatric comorbidities. Patients with moderate and severe clinical picture are treated with psychotherapy and pharmacological therapy. Deep brain stimulation (DBS) is reserved for pharmacological refractory GTS patients. As GTS tends to improve with time and potentially resolves in the second decade of life, the major concern of DBS in GTS is the age at which the patient undergoes surgical procedure. Some authors suggest performing DBS after 18 years, others after 25 years of age. Case Description: We present a 25-year-old patient with GTS, who was aged 17 years and was treated with thalamic DBS. DBS resulted in progressive and sustained improvement of tics and co-morbidities. After 6 years of DBS treatment, it was noted that the clinical improvement was maintained also in OFF stimulation setting, so it was decided to keep it off. After 2 years in off-setting and stable clinical picture the entire DBS device was removed. Six months after DBS device removal the patient remained symptom-free. Conclusions: DBS is a therapeutic option reserved for severe and refractory GTS cases. In our opinion DBS might be considered as a temporary application in GTS. PMID:26290773

  17. Explaining clinical effects of deep brain stimulation through simplified target-specific modeling of the volume of activated tissue.

    Science.gov (United States)

    Mädler, B; Coenen, V A

    2012-06-01

    Although progress has been made in understanding the optimal anatomic structures as target areas for DBS, little effort has been put into modeling and predicting electromagnetic field properties of activated DBS electrodes and understanding their interactions with the adjacent tissue. Currently, DBS is performed with the patient awake to assess the effectiveness and the side effect spectrum of stimulation. This study was designed to create a robust and rather simple numeric and visual tool that provides sufficient and practical relevant information to visualize the patient's individual VAT. Multivariate polynomial fitting of previously obtained data from a finite-element model, based on a similar DBS system, was used. The model estimates VAT as a first-approximation sphere around the active DBS contact, using stimulation voltages and individual tissue-electrode impedances. Validation uses data from 2 patients with PD by MR imaging, DTI, fiber tractography, and postoperative CT data. Our model can predict VAT for impedances between 500 and 2000 Ω with stimulation voltages up to 10 V. It is based on assumptions for monopolar DBS. Evaluation of 2 DBS cases showed a convincing correspondence between predicted VAT and neurologic (side) effects (internal capsule activation). Stimulation effects during DBS can be readily explained with this simple VAT model. Its implementation in daily clinical routine might help in understanding the types of tissues activated during DBS. This technique might have the potential to facilitate DBS implantations with the patient under general anesthesia while yielding acceptable clinical effectiveness.

  18. Medial Forebrain Bundle Deep Brain Stimulation has Symptom-specific Anti-depressant Effects in Rats and as Opposed to Ventromedial Prefrontal Cortex Stimulation Interacts With the Reward System.

    Science.gov (United States)

    Edemann-Callesen, Henriette; Voget, Mareike; Empl, Laura; Vogel, Martin; Wieske, Franziska; Rummel, Julia; Heinz, Andreas; Mathé, Aleksander A; Hadar, Ravit; Winter, Christine

    2015-01-01

    In recent years, deep brain stimulation (DBS) has emerged as a promising treatment option for patients suffering from treatment-resistant depression (TRD). Several stimulation targets have successfully been tested in clinical settings, including the subgenual cingulum (Cg25) and the medial forebrain bundle (MFB). MFB-DBS has led to remarkable results, surpassing the effect of previous targets in terms of response latency and number of responders. However, the question remains as to which mechanisms underlie this difference. The aim of the present study was to thoroughly study the anti-depressant effect of MFB-DBS in the Flinders sensitive line (FSL) rat model of depression as well as to investigate whether MFB-DBS and Cg25-DBS operate through the same neurobiological circuits. FSL and control rats received bilateral high-frequency stimulation to the MFB at the level of the lateral hypothalamus, while being subjected to a variety of depression- and anxiety-related behavioral paradigms. To further compare the effects of MFB-DBS and Cg25-DBS on reward-related behavior, animals were stimulated in either the MFB or ventromedial prefrontal cortex (vmPFC, rodent analog to Cg25), while being tested in the intra-cranial self-stimulation paradigm. A marked symptom-specific anti-depressant effect of MFB-DBS was demonstrated. The ICSS-paradigm revealed that MFB-DBS, as opposed to vmPFC-DBS interacts with the reward system. Our data suggest that MFB-DBS and Cg25-DBS do not operate via the same neurobiological circuits. This differentiation might be of interest when selecting patients for either Cg25- or MFB-DBS. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Quadruple deep brain stimulation in Huntington's disease, targeting pallidum and subthalamic nucleus: case report and review of the literature.

    Science.gov (United States)

    Gruber, D; Kuhn, A A; Schoenecker, T; Kopp, U A; Kivi, A; Huebl, J; Lobsien, E; Mueller, B; Schneider, G-H; Kupsch, A

    2014-10-01

    Deep brain stimulation (DBS) represents an established treatment option in a growing number of movement disorders. Recent case reports suggest beneficial effect of globus pallidus internus (GPi)-DBS in selected patients suffering from Huntington's disease with marked disabling chorea. We present a 41-year-old man with genetically confirmed HD following quadruple GPi- and subthalamic nucleus (STN)-DBS. Motor function was assessed by Abnormal Involuntary Movement Scale (AIMS) and by Unified Huntington Disease Rating Scale (UHDRS) presurgery and postsurgery for up to 4 years. Furthermore, cognitive, neuropsychiatric state and quality of life (QoL) including life satisfaction (QLS) were annually evaluated. Chorea assessed by AIMS and UHDRS subscores improved by 52 and 55 %, 45 and 60 %, 35 and 45 % and 55-66 % at 1-4 years, respectively, compared to presurgical state following GPi-STN-DBS. During these time periods bradykinesia did not increase following separate STN- and combined GPi-STN-DBS compared to presurgical state. Mood, QoL and QLS were ameliorated. However, dysexecutive symptoms increased at 4 years postsurgery. The present case report suggests that bilateral GPi- and STN-DBS may represent a new treatment avenue in selected HD patients. Clinically, GPi-DBS attenuated chorea and was associated with a larger effect-adverse effect window compared to STN-DBS. However, GPi-DBS-induced bradykinesia may emerge as one main limitation of GPi-DBS in HD. Thus, quadruple GPi-STN-DBS may be indicated, if separate GPi-DBS does not result in sufficient control of motor symptoms. Future controlled studies need to confirm if the present anecdotal observation of additive beneficial effects of GPi- and STN-DBS in a HD patient with severe generalized chorea and relatively intact cognitive and affective functions indeed represents a new therapeutic option.

  20. Target Selection Recommendations Based on Impact of Deep Brain Stimulation Surgeries on Nonmotor Symptoms of Parkinson's Disease

    Institute of Scientific and Technical Information of China (English)

    Xiao-Houg Wang; Lin Zhang; Laura Sperry; John Olichney; Sarah Tomaszewski Farias; Kiarash Shahlaie; Norika Malhado Chang

    2015-01-01

    Objective: This review examines the evidence that deep brain stimulation (DBS) has extensive impact on nonmotor symptoms (NMSs) of patients with Parkinson's disease (PD).Data Sources: We retrieved information from the PubMed database up to September, 2015, using various search terms and their combinations including PD, NMSs, DBS, globus pallidus intemus (GPi), subthalamic nucleus (STN), and ventral intermediate thalamic nucleus.Study Selection: We included data from peer-reviewed journals on impacts of DBS on neuropsychological profiles, sensory function, autonomic symptoms, weight changes, and sleep disturbances.For psychological symptoms and cognitive impairment, we tried to use more reliable proofs: Random, control, multicenter, large sample sizes, and long period follow-up clinical studies.We categorized the NMSs into four groups: those that would improve definitively following DBS;those that are not significantly affected by DBS;those that remain controversial on their surgical benefit;and those that can be worsened by DBS.Results: In general, it seems to be an overall beneficial effect of DBS on NMSs, such as sensory, sleep, gastrointestinal, sweating, cardiovascular, odor, urological symptoms, and sexual dysfunction, GPi-DBS may produce similar results;Both STN and Gpi-DBS are safe with regard to cognition and psychology over long-term follow-up, though verbal fluency decline is related to DBS;The impact of DBS on behavioral addictions and dysphagia is still uncertain.Conclusions: As the motor effects of STN-DBS and GPi-DBS are similar, NMSs may determine the target choice in surgery of future patients.

  1. Why dried blood spots are an ideal tool for CYP1A2 phenotyping.

    Science.gov (United States)

    De Kesel, Pieter M M; Lambert, Willy E; Stove, Christophe P

    2014-08-01

    Dried blood spot (DBS) sampling has gained wide interest in bioanalysis during the last decade and has already been successfully applied in pharmacokinetic and phenotyping studies. However, all of the available phenotyping studies used small datasets and did not include a systematic evaluation of DBS-specific parameters. The latter is important since several of these factors still challenge the breakthrough of DBS in routine practice. In this study, caffeine and paraxanthine are determined in capillary DBS, venous DBS, whole blood and plasma for cytochrome P450 (CYP) 1A2 phenotyping. The aim of this study was to explore the usefulness of DBS as a tool for CYP1A2 phenotyping. A CYP1A2 phenotyping study was conducted in 73 healthy volunteers who received a 150 mg oral dose of caffeine. Six hours post-administration, caffeine and paraxanthine concentrations and paraxanthine:caffeine molar concentration ratios, i.e., the actual CYP1A2 phenotyping indices, were determined in capillary DBS (obtained by non-volumetric application, direct from the fingertip), venous DBS, whole blood, and plasma. Furthermore, the impact of DBS-specific parameters, including hematocrit, volume spotted, and punch location, was evaluated. Concentrations of caffeine and paraxanthine in capillary DBS were, respectively, on average 12.7 and 13.8% lower than those in venous DBS and 31.5 and 33.1% lower than those in plasma. While these differences were statistically significant (p phenotyping study to date, we have demonstrated that CYP1A2 phenotyping in capillary DBS is a valid and convenient alternative for the classical plasma-based approach. Additionally, we have provided an objective basis as to why DBS are an ideal tool for CYP1A2 phenotyping.

  2. Improved electrode material for deep brain stimulation.

    Science.gov (United States)

    Petrossians, A; Whalen, J J; Weiland, J D

    2016-08-01

    Deep brain stimulation (DBS) devices have been implanted for treatment of basic tremor, Parkinson's disease and dystonia. These devices use electrodes in contact with tissue to deliver electrical pulses to targeted cells, to elicit specific therapeutic responses. In general, the neuromodulation industry has been evolving towards smaller, less invasive electrodes. However, current electrode materials do not support small sizes without severely restricting the stimulus output. Hence, an improved electrode material will benefit present and future DBS systems. In this study, five DBS leads were modified using a cost-effective and materials-efficient process for applying an ultra-low impedance platinum-iridium alloy coating. One DBS lead was used for insertion test and four DBS leads were chronically pulsed for 12 weeks. The platinum-iridium alloy significantly improved the electrical properties of the DBS electrodes and was robust to insertion into brain and to 12 weeks of chronic pulsing.

  3. State of the Art: Novel Applications for Deep Brain Stimulation.

    Science.gov (United States)

    Roy, Holly A; Green, Alexander L; Aziz, Tipu Z

    2017-05-17

    Deep brain stimulation (DBS) is a rapidly developing field of neurosurgery with potential therapeutic applications that are relevant to conditions traditionally viewed as beyond the limits of neurosurgery. Our objective, in this review, is to highlight some of the emerging applications of DBS within three distinct but overlapping spheres, namely trauma, neuropsychiatry, and autonomic physiology. An extensive literature review was carried out in MEDLINE, to identify relevant studies and review articles describing applications of DBS in the areas of trauma, neuropsychiatry and autonomic neuroscience. A wide range of applications of DBS in these spheres was identified, some having only been tested in one or two cases, others much better studied. We have identified various avenues for DBS to be applied for patient benefit in cases relevant to trauma, neuropsychiatry and autonomic neuroscience. Further developments in DBS technology and clinical trial design will enable these novel applications to be effectively and rigorously assessed and utilized most effectively. © 2017 International Neuromodulation Society.

  4. Abnormal thalamocortical dynamics may be altered by deep brain stimulation: using magnetoencephalography to study phantom limb pain.

    Science.gov (United States)

    Ray, N J; Jenkinson, N; Kringelbach, M L; Hansen, P C; Pereira, E A; Brittain, J S; Holland, P; Holliday, I E; Owen, S; Stein, J; Aziz, T

    2009-01-01

    Deep brain stimulation (DBS) is used to alleviate chronic pain. Using magnetoencephalography (MEG) to study the mechanisms of DBS for pain is difficult because of the artefact caused by the stimulator. We were able to record activity over the occipital lobe of a patient using DBS for phantom limb pain during presentation of a visual stimulus. This demonstrates that MEG can be used to study patients undergoing DBS provided control stimuli are used to check the reliability of the data. We then asked the patient to rate his pain during and off DBS. Correlations were found between these ratings and power in theta (6-9) and beta bands (12-30). Further, there was a tendency for frequencies under 25 Hz to correlate with each other after a period off stimulation compared with immediately after DBS. The results are interpreted as reflecting abnormal thalamocortical dynamics, previously implicated in painful syndromes.

  5. Catatonia after deep brain stimulation successfully treated with lorazepam and right unilateral electroconvulsive therapy: a case report.

    Science.gov (United States)

    Quinn, Davin K; Rees, Caleb; Brodsky, Aaron; Deligtisch, Amanda; Evans, Daniel; Khafaja, Mohamad; Abbott, Christopher C

    2014-09-01

    The presence of a deep brain stimulator (DBS) in a patient who develops neuropsychiatric symptoms poses unique diagnostic challenges and questions for the treating psychiatrist. Catatonia has been described only once, during DBS implantation, but has not been reported in a successfully implanted DBS patient. We present a case of a patient with bipolar disorder and renal transplant who developed catatonia after DBS for essential tremor. The patient was successfully treated for catatonia with lorazepam and electroconvulsive therapy after careful diagnostic workup. Electroconvulsive therapy has been successfully used with DBS in a handful of cases, and certain precautions may help reduce potential risk. Catatonia is a rare occurrence after DBS but when present may be safely treated with standard therapies such as lorazepam and electroconvulsive therapy.

  6. Role of adenosine in the antiepileptic effects of deep brain stimulation

    Science.gov (United States)

    Miranda, Maisa F.; Hamani, Clement; de Almeida, Antônio-Carlos G.; Amorim, Beatriz O.; Macedo, Carlos E.; Fernandes, Maria José S.; Nobrega, José N.; Aarão, Mayra C.; Madureira, Ana Paula; Rodrigues, Antônio M.; Andersen, Monica L.; Tufik, Sergio; Mello, Luiz E.; Covolan, Luciene

    2014-01-01

    Despite the effectiveness of anterior thalamic nucleus (AN) deep brain stimulation (DBS) for the treatment of epilepsy, mechanisms responsible for the antiepileptic effects of this therapy remain elusive. As adenosine modulates neuronal excitability and seizure activity in animal models, we hypothesized that this nucleoside could be one of the substrates involved in the effects of AN DBS. We applied 5 days of stimulation to rats rendered chronically epileptic by pilocarpine injections and recorded epileptiform activity in hippocampal slices. We found that slices from animals given DBS had reduced hippocampal excitability and were less susceptible to develop ictal activity. In live animals, AN DBS significantly increased adenosine levels in the hippocampus as measured by microdialysis. The reduced excitability of DBS in vitro was completely abolished in animals pre-treated with A1 receptor antagonists and was strongly potentiated by A1 receptor agonists. We conclude that some of the antiepileptic effects of DBS may be mediated by adenosine. PMID:25324724

  7. Sterically stabilized water based magnetic fluids: Synthesis, structure and properties

    Science.gov (United States)

    Bica, Doina; Vékás, Ladislau; Avdeev, Mikhail V.; Marinică, Oana; Socoliuc, Vlad; Bălăsoiu, Maria; Garamus, Vasil M.

    2007-04-01

    Magnetic fluids (MFs), prepared by chemical co-precipitation followed by double layer steric and electrostatic (combined) stabilization of magnetite nanoparticles dispersed in water, are presented. Several combinations of surfactants with different chain lengths (lauric acid (LA), myristic acid (MA), oleic acid (OA) and dodecyl-benzene-sulphonic acid (DBS)) were used, such as LA+LA, MA+MA, LA+DBS, MA+DBS, OA+DBS, OA+OA and DBS+DBS. Static light scattering, transmission electron microscopy, small angle neutron scattering, magnetic and magneto-rheological measurements revealed that MFs with MA+MA or LA+LA biocompatible double layer covered magnetite nanoparticles are the most stable colloidal systems among the investigated samples, and thus suitable for biomedical applications.

  8. Sterically stabilized water based magnetic fluids: Synthesis, structure and properties

    Energy Technology Data Exchange (ETDEWEB)

    Bica, Doina [Laboratory of Magnetic Fluids, Center for Fundamental and Advanced Technical Research, Romanian Academy, Timisoara Division, Bd. Mihai Viteazul 24, 300223 Timisoara (Romania); Vekas, Ladislau [Laboratory of Magnetic Fluids, Center for Fundamental and Advanced Technical Research, Romanian Academy, Timisoara Division, Bd. Mihai Viteazul 24, 300223 Timisoara (Romania) and National Centre for Engineering of Systems with Complex Fluids, University Politehnica Timisoara, Bd. Mihai Viteazul 1, 300222 Timisoara (Romania)]. E-mail: vekas@acad-tim.tm.edu.ro; Avdeev, Mikhail V. [Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); Marinica, Oana [National Centre for Engineering of Systems with Complex Fluids, University Politehnica Timisoara, Bd. Mihai Viteazul 1, 300222 Timisoara (Romania); Socoliuc, Vlad [National Institute R and D for Electrochemistry and Condensed Matter, Str. Diaconu Coressi 144, 300588 Timisoara (Romania); Balasoiu, Maria [Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); Garamus, Vasil M. [GKSS Research Centre, Geesthacht (Germany)

    2007-04-15

    Magnetic fluids (MFs), prepared by chemical co-precipitation followed by double layer steric and electrostatic (combined) stabilization of magnetite nanoparticles dispersed in water, are presented. Several combinations of surfactants with different chain lengths (lauric acid (LA), myristic acid (MA), oleic acid (OA) and dodecyl-benzene-sulphonic acid (DBS)) were used, such as LA+LA, MA+MA, LA+DBS, MA+DBS, OA+DBS, OA+OA and DBS+DBS. Static light scattering, transmission electron microscopy, small angle neutron scattering, magnetic and magneto-rheological measurements revealed that MFs with MA+MA or LA+LA biocompatible double layer covered magnetite nanoparticles are the most stable colloidal systems among the investigated samples, and thus suitable for biomedical applications.

  9. Clinical relevance of the discrepancy in phenylalanine concentrations analyzed using tandem mass spectrometry compared with ion-exchange chromatography in phenylketonuria

    Directory of Open Access Journals (Sweden)

    Bridget M. Stroup

    2016-03-01

    Conclusion: Use of DBS analyzed using MS/MS to monitor blood phe concentrations in individuals with PKU yields significantly lower phe levels compared to plasma phe levels analyzed using IEC. Optimization of current testing methodologies for measuring phe in DBS, along with patient education regarding the appropriate technique for spotting blood on filter paper is needed to improve the accuracy of using DBS to measure phe concentrations in PKU management.

  10. Effets de la stimulation cérébrale profonde sur l’équilibre et la marche chez les patients atteints de la maladie de Parkinson : une revue systématique neurophysiologique

    OpenAIRE

    Collomb-Clerc, Antoine; Welter, Marie-Laure

    2015-01-01

    International audience; Deep brain stimulation (DBS) of the subthalamic nucleus (STN) and internal globus pallidus (GPi) deep brain stimulation (DBS) provides an efficient treatment for the alleviation of motor signs in patients with Parkinson's disease. The effects of DBS on gait and balance disorders are less successful and may even lead to an aggravation of freezing of gait and imbalance. The identification of a substantia nigra pars reticulata (SNr)-mesencephalic locomotor region (MLR) ne...

  11. Systematic review of the use of dried blood spots for monitoring HIV viral load and for early infant diagnosis.

    Directory of Open Access Journals (Sweden)

    Pieter W Smit

    Full Text Available BACKGROUND: Dried blood spots (DBS have been used as alternative specimens to plasma to increase access to HIV viral load (VL monitoring and early infant diagnosis (EID in remote settings. We systematically reviewed evidence on the performance of DBS compared to plasma for VL monitoring and EID. METHODS AND FINDINGS: Thirteen peer reviewed HIV VL publications and five HIV EID papers were included. Depending on the technology and the viral load distribution in the study population, the percentage of DBS samples that are within 0.5 log of VL in plasma ranged from 52-100%. Because the input sample volume is much smaller in a blood spot, there is a risk of false negatives with DBS. Sensitivity of DBS VL was found to be 78-100% compared to plasma at VL below 1000 copies/ml, but this increased to 100% at a threshold of 5000 copies/ml. Unlike a plasma VL test which measures only cell free HIV RNA, a DBS VL also measures proviral DNA as well as cell-associated RNA, potentially leading to false positive results when using DBS. The systematic review showed that specificity was close to 100% at DBS VL above 5000 copies/ml, and this threshold would be the most reliable for predicting true virologic failure using DBS. For early infant diagnosis, DBS has a sensitivity of 100% compared to fresh whole blood or plasma in all studies. CONCLUSIONS: Although limited data are available for EID, DBS offer a highly sensitive and specific sampling strategy to make viral load monitoring and early infant diagnosis more accessible in remote settings. A standardized approach for sampling, storing, and processing DBS samples would be essential to allow successful implementation. TRIAL REGISTRATION: PROSPERO Registration #: CRD42013003621.

  12. Systematic Review of the Use of Dried Blood Spots for Monitoring HIV Viral Load and for Early Infant Diagnosis

    Science.gov (United States)

    Smit, Pieter W.; Sollis, Kimberly A.; Fiscus, Susan; Ford, Nathan; Vitoria, Marco; Essajee, Shaffiq; Barnett, David; Cheng, Ben; Crowe, Suzanne M.; Denny, Thomas; Landay, Alan; Stevens, Wendy; Habiyambere, Vincent; Perriens, Joseph H.; Peeling, Rosanna W.

    2014-01-01

    Background Dried blood spots (DBS) have been used as alternative specimens to plasma to increase access to HIV viral load (VL) monitoring and early infant diagnosis (EID) in remote settings. We systematically reviewed evidence on the performance of DBS compared to plasma for VL monitoring and EID. Methods and Findings Thirteen peer reviewed HIV VL publications and five HIV EID papers were included. Depending on the technology and the viral load distribution in the study population, the percentage of DBS samples that are within 0.5 log of VL in plasma ranged from 52–100%. Because the input sample volume is much smaller in a blood spot, there is a risk of false negatives with DBS. Sensitivity of DBS VL was found to be 78–100% compared to plasma at VL below 1000 copies/ml, but this increased to 100% at a threshold of 5000 copies/ml. Unlike a plasma VL test which measures only cell free HIV RNA, a DBS VL also measures proviral DNA as well as cell-associated RNA, potentially leading to false positive results when using DBS. The systematic review showed that specificity was close to 100% at DBS VL above 5000 copies/ml, and this threshold would be the most reliable for predicting true virologic failure using DBS. For early infant diagnosis, DBS has a sensitivity of 100% compared to fresh whole blood or plasma in all studies. Conclusions Although limited data are available for EID, DBS offer a highly sensitive and specific sampling strategy to make viral load monitoring and early infant diagnosis more accessible in remote settings. A standardized approach for sampling, storing, and processing DBS samples would be essential to allow successful implementation. Trial Registration PROSPERO Registration #: CRD42013003621. PMID:24603442

  13. Fornix deep brain stimulation enhances acetylcholine levels in the hippocampus

    OpenAIRE

    2015-01-01

    Deep brain stimulation (DBS) of the fornix has gained interest as a potential therapy for advanced treatment-resistant dementia, yet the mechanism of action remains widely unknown. Previously, we have reported beneficial memory effects of fornix DBS in a scopolamine-induced rat model of dementia, which is dependent on various brain structures including hippocampus. To elucidate mechanisms of action of fornix DBS with regard to memory restoration, we performed c-Fos immunohistochemistry in the...

  14. Discussion boards: boring no more!

    Science.gov (United States)

    Adelman, Deborah S; Nogueras, Debra J

    2013-01-01

    Creating discussion boards (DBs) that capture student imaginations and contain meaningful interactions can be a difficult process. Traditional DBs use a question-and-answer format that often is boring for both the student and instructor. The authors present creative approaches to DBs that result in lively debates and student-to-student and student-to-faculty interactions, including role playing, blogging, wikis, and the use of voice.

  15. A 5-year journey with cutis laxa in an Indian child: The de barsy syndrome revisited

    Directory of Open Access Journals (Sweden)

    Abhijit Dutta

    2016-01-01

    Full Text Available De Barsy syndrome (DBS, synonymously known as autosomal recessive cutis laxa type III, is an extremely rare condition clinically characterized by cutis laxa, a progeroid appearance, and ophthalmologic abnormalities. We present here an account of 5-year follow-up since the birth of an Indian boy with DBS, who had a few rare and unusual manifestations. In addition, our case probably represents the first reported case of DBS from India.

  16. Deep Brain Stimulation in Tourette’s Syndrome

    OpenAIRE

    Fraint, Avram; Pal, Gian

    2015-01-01

    Objective Tourette’s syndrome (TS) is defined by 1 year of persistent motor and vocal tics. Often, the tics are refractory to conventional pharmacologic and psychobehavioral interventions. In these patients, deep brain stimulation (DBS) may be an appropriate intervention. This paper reviews different DBS targets in TS, discusses existing evidence on the efficacy of DBS in TS, highlights adverse effects of the procedure, discusses indications and patient selection as well as future directio...

  17. Hypomania with hypersexuality following bilateral anterior limb stimulation in obsessive-compulsive disorder.

    Science.gov (United States)

    Chang, Chun-Hung; Chen, Shin-Yuan; Hsiao, Yi-Ling; Tsai, Sheng-Tzung; Tsai, Hsin-Chi

    2010-06-01

    This 28-year-old Chinese man was referred for deep brain stimulation (DBS) evaluation for an 8-year history of refractory obsessive-compulsive disorder. After the patient had signed an informed consent, the authors implanted DBS leads. Hypomania with hypersexuality was noted on stimulation at Contact 2 and became aggravated with a higher voltage (> or = 3 V) during chronic bilateral DBS. After the voltage was decreased to 1 V, the patient's hypomanic symptoms subsided and his libido returned to baseline.

  18. Long-term follow-up study on the safety of deep brain stimulation for treating Parkinson's disease

    OpenAIRE

    Xi WU; Jian-chun CHEN; Wan-lu WANG; Hao, Bin; Chen, Xin; Xiao-wu HU

    2015-01-01

    Objective To evaluate the safety of deep brain stimulation (DBS) for treating Parkinson's disease (PD) under long-term follow-up and modify the surgical procedure. Methods A total of 362 PD patients underwent DBS, and almost 613 electrodes were implanted into these patients. Both surgical and hardware-related complications of DBS were retrospectively analyzed. Results Perioperative complications included postoperative confusion or delirium in 21 cases (5.80%), intracranial hemorrhage i...

  19. Motor Cortex Stimulation in Parkinson's Disease

    OpenAIRE

    Marisa De Rose; Giusy Guzzi; Domenico Bosco; Mary Romano; Serena Marianna Lavano; Massimiliano Plastino; Giorgio Volpentesta; Rosa Marotta; Angelo Lavano

    2012-01-01

    Motor Cortex Stimulation (MCS) is less efficacious than Deep Brain Stimulation (DBS) in Parkinson's disease. However, it might be proposed to patients excluded from DBS or unresponsive to DBS. Ten patients with advanced PD underwent unilateral MCS contralaterally to the worst clinical side. A plate electrode was positioned over the motor cortex in the epidural space through single burr hole after identification of the area with neuronavigation and neurophysiological tests. Clinical assessment...

  20. Deep brain stimulation for cluster headache

    DEFF Research Database (Denmark)

    Grover, Patrick J; Pereira, Erlick A C; Green, Alexander L

    2009-01-01

    Cluster headache is a severely debilitating disorder that can remain unrelieved by current pharmacotherapy. Alongside ablative neurosurgical procedures, neuromodulatory treatments of deep brain stimulation (DBS) and occipital nerve simulation have emerged in the last few years as effective...... circumstances to intervene. Here we review current data on neurosurgical interventions for chronic cluster headache focusing upon DBS and occipital nerve stimulation, and discuss the indications for and putative mechanisms of DBS including translational insights from functional neuroimaging, diffusion weighted...

  1. Current Topics in Deep Brain Stimulation for Parkinson Disease

    Science.gov (United States)

    UMEMURA, Atsushi; OYAMA, Genko; SHIMO, Yasushi; NAKAJIMA, Madoka; NAKAJIMA, Asuka; JO, Takayuki; SEKIMOTO, Satoko; ITO, Masanobu; MITSUHASHI, Takumi; HATTORI, Nobutaka; ARAI, Hajime

    2016-01-01

    There is a long history of surgical treatment for Parkinson disease (PD). After pioneering trials and errors, the current primary surgical treatment for PD is deep brain stimulation (DBS). DBS is a promising treatment option for patients with medically refractory PD. However, there are still many problems and controversies associated with DBS. In this review, we discuss current issues in DBS for PD, including patient selection, clinical outcomes, complications, target selection, long-term outcomes, management of axial symptoms, timing of surgery, surgical procedures, cost-effectiveness, and new technology. PMID:27349658

  2. Nonmotor Symptoms and Subthalamic Deep Brain Stimulation in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Han-Joon Kim

    2015-05-01

    Full Text Available Subthalamic deep brain stimulation (STN DBS is an established treatment for the motor symptoms in patients with advanced Parkinson’s disease (PD. In addition to improvements in motor symptoms, many studies have reported changes in various nonmotor symptoms (NMSs after STN DBS in patients with PD. Psychiatric symptoms, including depression, apathy, anxiety, and impulsivity, can worsen or improve depending on the electrical stimulation parameters, the locations of the stimulating contacts within the STN, and changes in medications after surgery. Global cognitive function is not affected by STN DBS, and there is no increase in the incidence of dementia after STN DBS compared to that after medical treatment, although clinically insignificant declines in verbal fluency have been consistently reported. Pain, especially PD-related pain, improves with STN DBS. Evidence regarding the effects of STN DBS on autonomic symptoms and sleep-related problems is limited and remains conflicting. Many symptoms of nonmotor fluctuations, which are occasionally more troublesome than motor fluctuations, improve with STN DBS. Although it is clear that NMSs are not target symptoms for STN DBS, NMSs have a strong influence on the quality of life of patients with PD, and clinicians should thus be aware of these NMSs when deciding whether to perform surgery and should pay attention to changes in these symptoms after STN DBS to ensure the optimal care for patients.

  3. Potentiometric study of polyaniline film synthesized with various dopants and composite-dopant: A comparative study

    Indian Academy of Sciences (India)

    P D Gaikwad; D J Shirale; V K Gade; P A Savale; K P Kakde; H J Kharat; M D Shirsat

    2006-08-01

    The potentiometric study of polyaniline (PANI) film synthesized with dopants viz. polyvinyl sulfonic acid (PVS), -toluene sulfonic acid (TS), dodecyl benzene sulfonic acid (DBS) and composite-dopants viz. PVS–TS and PVS–DBS, has been carried out. The synthesized PANI films were characterized by electrochemical technique, UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and conductivity measurement. It was found that the PANI doped with PVS gives good electrochemical properties, conductivity as well as surface morphology as compared to TS and DBS, whereas in composite dopants the PANI doped with PVS–TS gives good polymer matrix as compared to PVS–DBS.

  4. Introduction to the programming of deep brain stimulators.

    Science.gov (United States)

    Volkmann, Jens; Herzog, Jan; Kopper, Florian; Deuschl, Güntner

    2002-01-01

    The clinical success of deep brain stimulation (DBS) for treating Parkinson's disease, tremor, or dystonia critically depends on the quality of postoperative neurologic management. Movement disorder specialists becoming involved with this therapy need to acquire new skills to optimally adapt stimulation parameters and medication after implantation of a DBS system. In clinical practice, the infinite number of possible parameter settings in DBS can be reduced to few relevant combinations. In this article, the authors describe a general scheme of selecting stimulation parameters in DBS and provide clinical and neurophysiological arguments for such a standardized algorithm. They also describe noninvasive technical trouble shooting by using programming features of the commercially available neurostimulation devices.

  5. Antibiotic impregnated catheter coverage of deep brain stimulation leads facilitates lead preservation after hardware infection.

    Science.gov (United States)

    Dlouhy, Brian J; Reddy, Ambur; Dahdaleh, Nader S; Greenlee, Jeremy D W

    2012-10-01

    Deep brain stimulation (DBS) has become a reliable and effective treatment for many disorders. However, the risk of long-term hardware-related complications is notable, and most concerning is hardware-related infections. Given the risk of hardware removal in the setting of infection, we retrospectively examined the implementation of a novel technique using antibiotic covered catheter protection of DBS leads after infection. The effect on hardware salvage and ease of reimplantation of the DBS extension and implantable pulse generator (IPG) was examined. A total of nine (9%) out of 100 DBS patients met the inclusion criteria with 11 DBS hardware-related infections at either the frontal, parietal, or IPG sites, from June 2003 to November 2010, at our institution. Subsequent to the initial patient in the series, a total of eight patients had placement of a short segment (approx. 4 cm long) of antibiotic impregnated catheter (Bactiseal, Codman, Johnson & Johnson, Raynham, MA, USA) over the distal end of the DBS leads at the parietal incision. Seven of these eight patients presented with pus and deep tissue infections around the hardware at either the frontal, parietal, or chest incisions. In seven of these eight patients (87.5%) we were able to protect and salvage their DBS leads without need for removal. In conclusion, this novel technique provides a simple reimplantation operation, with a decreased risk of DBS lead damage. It may improve the preservation of DBS leads when hardware infection occurs, is inexpensive, and confers no additional risks to patients.

  6. Impulse Control Disorders Following Deep Brain Stimulation of the Subthalamic Nucleus in Parkinson's Disease: Clinical Aspects

    Directory of Open Access Journals (Sweden)

    Polyvios Demetriades

    2011-01-01

    literature search identified four original studies examining a total of 182 patients for ICDs and nine case reports of 39 patients that underwent DBS and developed ICDs at some point. Data analysis from the original studies did not identify a significant difference in ICDs between patients receiving dopaminergic medication and patients on DBS, whilst the case reports showed that 56% of patients undergoing DBS had poor outcome with regards to ICDs. We discuss these ambivalent findings in the light of proposed pathogenetic mechanisms. Longitudinal, prospective studies with larger number of patients are required in order to fully understand the role of DBS on ICDs in patients with PD.

  7. Caracterización de músculos artificiales con capacidades sensores/actuadores e intercambio mayoritario de cationes

    OpenAIRE

    Valero Conzuelo, Laura Luz

    2015-01-01

    [SPA] En esta tesis se describe la síntesis electroquímica de películas gruesas de polipirrol/DBS. Las películas se despegan del electrodo y se usan como electrodos autosoportados, para construir bicapas (pPy/DBS-cinta adhesiva) o tricapas (pPy/DBS-cinta-pPy/DBS). El comportamiento electroquímico de la película polimérica, utilizada como electrodo autosoportado, es caracterizado mediante diferentes técnicas electroquímicas. Repitiendo la caracterización variando ahora la concentración del med...

  8. Authenticity or autonomy? When deep brain stimulation causes a dilemma.

    Science.gov (United States)

    Kraemer, Felicitas

    2013-12-01

    While deep brain stimulation (DBS) for patients with Parkinson's disease has typically raised ethical questions about autonomy, accountability and personal identity, recent research indicates that we need to begin taking into account issues surrounding the patients' feelings of authenticity and alienation as well. In order to bring out the relevance of this dimension to ethical considerations of DBS, I analyse a recent case study of a Dutch patient who, as a result of DBS, faced a dilemma between autonomy and authenticity. This case study is meant to point out the normatively meaningful tension patients under DBS experience between authenticity and autonomy.

  9. Stable cognitive functioning with improved perceptual reasoning in children with dyskinetic cerebral palsy and other secondary dystonias after deep brain stimulation.

    Science.gov (United States)

    Owen, Tamsin; Adegboye, Dolapo; Gimeno, Hortensia; Selway, Richard; Lin, Jean-Pierre

    2017-01-01

    Dystonia is characterised by involuntary movements (twisting, writhing and jerking) and postures. Secondary dystonias are described as a heterogeneous group of disorders with both exogenous and endogenous causes. There is a growing body of literature on the effects of deep brain stimulation (DBS) surgery on the motor function in childhood secondary dystonias, however research on cognitive function after DBS is scarce. Cognitive function was measured in a cohort of 40 children with secondary dystonia following DBS surgery using a retrospective repeated measures design. Baseline pre-DBS neuropsychological measures were compared to scores obtained at least one year following DBS. Cognitive function was assessed using standardised measures of intellectual ability and memory. There was no significant change in the assessed domains of cognitive function following DBS surgery. A significant improvement across the group was found on the Picture Completion subtest, measuring perceptual reasoning ability, following DBS. Cognition remained stable in children with secondary dystonia following DBS surgery, with some improvements noted in a domain of perceptual reasoning. Further research with a larger sample is necessary to further explore this, in particular to further subdivide this group to account for its heterogeneity. This preliminary data has potentially positive implications for the impact of DBS on cognitive functioning within the childhood secondary dystonia population. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  10. Effects of dopaminergic and subthalamic stimulation on musical performance.

    Science.gov (United States)

    van Vugt, Floris T; Schüpbach, Michael; Altenmüller, Eckart; Bardinet, Eric; Yelnik, Jérôme; Hälbig, Thomas D

    2013-05-01

    Although subthalamic-deep brain stimulation (STN-DBS) is an efficient treatment for Parkinson's disease (PD), its effects on fine motor functions are not clear. We present the case of a professional violinist with PD treated with STN-DBS. DBS improved musical articulation, intonation and emotional expression and worsened timing relative to a timekeeper (metronome). The same effects were found for dopaminergic treatment. These results suggest that STN-DBS, mimicking the effects of dopaminergic stimulation, improves fine-tuned motor behaviour whilst impairing timing precision.

  11. Amino acid management of Parkinson's disease: a case study [Corrigendum

    Directory of Open Access Journals (Sweden)

    Hinz M

    2016-06-01

    Full Text Available Hinz M, Stein A, Uncini T. Int J Gen Med. 2011:4 165–174 On page 173, Disclosure section, “MH discloses ownership of DBS Labs, Duluth, MN, USA. TU discloses directorship of DBS Labs, Duluth, MN, USA. AS reports no conflicts of interest in this work.” should have read “MH discloses his relationship with West Duluth Distribution Company which terminated June 2011 and ownership of DBS Labs, Duluth, MN, USA. TU discloses directorship of DBS Labs, Duluth, MN, USA. AS reports no conflicts of interest in this work.”Read the original article.

  12. Proceedings of the Third Annual Deep Brain Stimulation Think Tank: A Review of Emerging Issues and Technologies.

    Science.gov (United States)

    Rossi, P Justin; Gunduz, Aysegul; Judy, Jack; Wilson, Linda; Machado, Andre; Giordano, James J; Elias, W Jeff; Rossi, Marvin A; Butson, Christopher L; Fox, Michael D; McIntyre, Cameron C; Pouratian, Nader; Swann, Nicole C; de Hemptinne, Coralie; Gross, Robert E; Chizeck, Howard J; Tagliati, Michele; Lozano, Andres M; Goodman, Wayne; Langevin, Jean-Philippe; Alterman, Ron L; Akbar, Umer; Gerhardt, Greg A; Grill, Warren M; Hallett, Mark; Herrington, Todd; Herron, Jeffrey; van Horne, Craig; Kopell, Brian H; Lang, Anthony E; Lungu, Codrin; Martinez-Ramirez, Daniel; Mogilner, Alon Y; Molina, Rene; Opri, Enrico; Otto, Kevin J; Oweiss, Karim G; Pathak, Yagna; Shukla, Aparna; Shute, Jonathan; Sheth, Sameer A; Shih, Ludy C; Steinke, G Karl; Tröster, Alexander I; Vanegas, Nora; Zaghloul, Kareem A; Cendejas-Zaragoza, Leopoldo; Verhagen, Leonard; Foote, Kelly D; Okun, Michael S

    2016-01-01

    The proceedings of the 3rd Annual Deep Brain Stimulation Think Tank summarize the most contemporary clinical, electrophysiological, imaging, and computational work on DBS for the treatment of neurological and neuropsychiatric disease. Significant innovations of the past year are emphasized. The Think Tank's contributors represent a unique multidisciplinary ensemble of expert neurologists, neurosurgeons, neuropsychologists, psychiatrists, scientists, engineers, and members of industry. Presentations and discussions covered a broad range of topics, including policy and advocacy considerations for the future of DBS, connectomic approaches to DBS targeting, developments in electrophysiology and related strides toward responsive DBS systems, and recent developments in sensor and device technologies.

  13. The Third Annual Deep Brain Stimulation Think Tank: A Review of Emerging Issues and Technologies

    Directory of Open Access Journals (Sweden)

    P. Justin eRossi

    2016-04-01

    Full Text Available This review summarizes the most contemporary clinical, electrophysiological, imaging, and computational work on DBS for the treatment of neurological and neuropsychiatric disease. Significant innovations of the past year are emphasized; these advances were presented at the 3rd Annual Deep Brain Stimulation Think Tank. The Think Tank’s contributors represent a unique multidisciplinary ensemble of expert neurologists, neurosurgeons, neuropsychologists, psychiatrists, scientists, engineers, and members of industry. Presentations and discussions covered a broad range of topics, including policy and advocacy considerations for the future of DBS, connectomic approaches to DBS targeting, developments in electrophysiology and related strides toward responsive DBS systems, and recent developments in sensor and device technologies.

  14. Emerging subspecialties in neurology: deep brain stimulation and electrical neuro-network modulation.

    Science.gov (United States)

    Hassan, Anhar; Okun, Michael S

    2013-01-29

    Deep brain stimulation (DBS) is a surgical therapy that involves the delivery of an electrical current to one or more brain targets. This technology has been rapidly expanding to address movement, neuropsychiatric, and other disorders. The evolution of DBS has created a niche for neurologists, both in the operating room and in the clinic. Since DBS is not always deep, not always brain, and not always simply stimulation, a more accurate term for this field may be electrical neuro-network modulation (ENM). Fellowships will likely in future years evolve their scope to include other technologies, and other nervous system regions beyond typical DBS therapy.

  15. Multiple station beamline at an undulator x-ray source

    DEFF Research Database (Denmark)

    Als-Nielsen, J.; Freund, A.K.; Grübel, G.

    1994-01-01

    -ray transparent monochromator crystals. Diamond in particular is an attractive monochromator as it is rather X-ray transparent and can be fabricated to a high degree of crystal perfection. Moreover, it has a very high heat conductivity and a rather small thermal expansion so the beam X-ray heat load problem...

  16. Demographic Data, U.S. Census 1990 Rhode Island Data; Sample Count & Source Data ;s44dbs92; U.S. Census 1990 pop, housing, economic, education, ethnic origin, and employment information by town, tract, and block group level as derived from U.S. Census STF3a, Published in 1992, 1:100000 (1in=8333ft) scale, State of Rhode Island and Providence Plantations.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Demographic Data dataset, published at 1:100000 (1in=8333ft) scale, was produced all or in part from Other information as of 1992. It is described as 'U.S....

  17. Disruption in proprioception from long-term thalamic deep brain stimulation: A pilot study

    Directory of Open Access Journals (Sweden)

    Jennifer A Semrau

    2015-05-01

    Full Text Available Deep brain stimulation (DBS is an excellent treatment for tremor and is generally thought to be reversible by turning off stimulation. For tremor, DBS is implanted in the ventrointermedius (Vim nucleus of the thalamus, a region that relays proprioceptive information for movement sensation (kinaesthesia. Gait disturbances have been observed with bilateral Vim DBS, but the long-term effects on proprioceptive processing are unknown. We aimed to determine whether Vim DBS surgical implantation or stimulation leads to proprioceptive deficits in the upper limb. We assessed two groups of tremor subjects on measures of proprioception (kinaesthesia, position sense and motor function using a robotic exoskeleton. In the first group (Surgery, we tested patients before and after implantation of Vim DBS, but before DBS was turned on to determine if proprioceptive deficits were inherent to tremor or caused by DBS implantation. In the second group (Stim, we tested subjects with chronically implanted Vim DBS ON and OFF stimulation. Compared to controls, there were no proprioceptive deficits before or after DBS implantation in the Surgery group. Surprisingly, those that received chronic long-term stimulation (LT-stim, 3-10 years displayed significant proprioceptive deficits ON and OFF stimulation not present in subjects with chronic short-term stimulation (ST-stim, 0.5-2 years. LT-stim had significantly larger variability and reduced workspace area during the position sense assessment. During the kinesthetic assessment, LT-stim made significantly larger directional errors and consistently underestimated the speed of the robot, despite generating normal movement speeds during motor assessment. Chronic long-term Vim DBS may potentially disrupt proprioceptive processing, possibly inducing irreversible plasticity in the Vim nucleus and/or its network connections. Our findings in the upper limb may help explain some of the gait disturbances seen by others following Vim

  18. Disruption in proprioception from long-term thalamic deep brain stimulation: a pilot study.

    Science.gov (United States)

    Semrau, Jennifer A; Herter, Troy M; Kiss, Zelma H; Dukelow, Sean P

    2015-01-01

    Deep brain stimulation (DBS) is an excellent treatment for tremor and is generally thought to be reversible by turning off stimulation. For tremor, DBS is implanted in the ventrointermedius (Vim) nucleus of the thalamus, a region that relays proprioceptive information for movement sensation (kinaesthesia). Gait disturbances have been observed with bilateral Vim DBS, but the long-term effects on proprioceptive processing are unknown. We aimed to determine whether Vim DBS surgical implantation or stimulation leads to proprioceptive deficits in the upper limb. We assessed two groups of tremor subjects on measures of proprioception (kinaesthesia, position sense) and motor function using a robotic exoskeleton. In the first group (Surgery), we tested patients before and after implantation of Vim DBS, but before DBS was turned on to determine if proprioceptive deficits were inherent to tremor or caused by DBS implantation. In the second group (Stim), we tested subjects with chronically implanted Vim DBS ON and OFF stimulation. Compared to controls, there were no proprioceptive deficits before or after DBS implantation in the Surgery group. Surprisingly, those that received chronic long-term stimulation (LT-stim, 3-10 years) displayed significant proprioceptive deficits ON and OFF stimulation not present in subjects with chronic short-term stimulation (ST-stim, 0.5-2 years). LT-stim had significantly larger variability and reduced workspace area during the position sense assessment. During the kinesthetic assessment, LT-stim made significantly larger directional errors and consistently underestimated the speed of the robot, despite generating normal movement speeds during motor assessment. Chronic long-term Vim DBS may potentially disrupt proprioceptive processing, possibly inducing irreversible plasticity in the Vim nucleus and/or its network connections. Our findings in the upper limb may help explain some of the gait disturbances seen by others following Vim DBS.

  19. Alterations in blood glucose and plasma glucagon concentrations during deep brain stimulation in the shell region of the nucleus accumbens in rats

    Directory of Open Access Journals (Sweden)

    Charlene eDiepenbroek

    2013-12-01

    Full Text Available Deep brain stimulation (DBS of the nucleus accumbens (NAc is an effective therapy for obsessive compulsive disorder (OCD and is currently under investigation as a treatment for eating disorders. DBS of this area is associated with altered food intake and pharmacological treatment of OCD is associated with the risk of developing type 2 diabetes. Therefore we examined if DBS of the NAc-shell (sNAc influences glucose metabolism. Male Wistar rats were subjected to DBS, or sham stimulation, for a period of one hour. To assess the effects of stimulation on blood glucose and glucoregulatory hormones, blood samples were drawn before, during and after stimulation. Subsequently, all animals were used for quantitative assessment of Fos immunoreactivity in the lateral hypothalamic area (LHA using computerized image analysis. DBS of the sNAc rapidly increased plasma concentrations of glucagon and glucose while sham stimulation and DBS outside the sNAc were ineffective. In addition, the increase in glucose was dependent on DBS intensity. In contrast, the DBS-induced increase in plasma corticosterone concentrations was independent of intensity and region, indicating that the observed DBS-induced metabolic changes were not due to corticosterone release. Stimulation of the sNAc with 200 μA increased Fos immunoreactivity in the LHA compared to sham or 100 μA stimulated animals. These data show that DBS of the sNAc alters glucose metabolism in a region- and intensity dependent manner in association with neuronal activation in the LHA. Moreover, these data illustrate the need to monitor changes in glucose metabolism during DBS-treatment of OCD patients.

  20. Moving forward: advances in the treatment of movement disorders with deep brain stimulation

    Directory of Open Access Journals (Sweden)

    Terry K Schiefer

    2011-11-01

    Full Text Available The modern era of stereotactic and functional neurosurgery has ushered in state of the art technologies for the treatment of movement disorders, particularly Parkinson’s disease (PD, tremor, and dystonia. After years of experience with various surgical therapies, the eventual shortcomings of both medical and surgical treatments, and several serendipitous discoveries, deep brain stimulation (DBS has risen to the forefront as a highly effective, safe, and reversible treatment for these conditions. Idiopathic advanced Parkinson’s disease can be treated with thalamic, globus pallidus internus (GPi, or subthalamic nucleus (STN DBS. Thalamic DBS primarily relieves tremor while GPi and STN DBS alleviate a wide range of Parkinsonian symptoms. Thalamic DBS is also used in the treatment of other types of tremor, particularly essential tremor, with excellent results. Both primary and various types of secondary dystonia can be treated very effectively with GPi DBS. The variety of anatomical targets for these movement disorders is indicative of the network-level dysfunction mediating these movement disturbances. Despite an increasing understanding of the clinical benefits of DBS, little is known about how DBS can create such wide sweeping neuromodulatory effects. The key to improving this therapeutic modality and discovering new ways to treat these and other neurologic conditions lies in better understanding the intricacies of DBS. Here we review the history and pertinent clinical data for DBS treatment of PD, tremor, and dystonia. Our search criteria for PubMed included combinations of the following terms: DBS, neuromodulation, movement disorders, PD, tremor, dystonia, and history. Dates were not restricted.

  1. Sixty hertz neurostimulation amplifies subthalamic neural synchrony in Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Zack Blumenfeld

    Full Text Available High frequency subthalamic nucleus (STN deep brain stimulation (DBS improves the cardinal motor signs of Parkinson's disease (PD and attenuates STN alpha/beta band neural synchrony in a voltage-dependent manner. While there is a growing interest in the behavioral effects of lower frequency (60 Hz DBS, little is known about its effect on STN neural synchrony. Here we demonstrate for the first time that during intra-operative 60 Hz STN DBS, one or more bands of resting state neural synchrony were amplified in the STN in PD. We recorded intra-operative STN resting state local field potentials (LFPs from twenty-eight STNs in seventeen PD subjects after placement of the DBS lead (model 3389, Medtronic, Inc. before and during three randomized neurostimulation sets (130 Hz/1.35V, 130 Hz/2V, 60 Hz/2V. During 130 Hz/2V DBS, baseline (no DBS STN alpha (8-12 Hz and beta (13-35 Hz band power decreased (N=14, P < 0.001 for both, whereas during 60 Hz/2V DBS, alpha band and peak frequency power increased (P = 0.012, P = 0.007, respectively. The effect of 60 Hz/2V DBS opposed that of power-equivalent (130 Hz/1.35V DBS (alpha: P < 0.001, beta: P = 0.006. These results show that intra-operative 60 Hz STN DBS amplified whereas 130 Hz STN DBS attenuated resting state neural synchrony in PD; the effects were frequency-specific. We demonstrate that neurostimulation may be useful as a tool to selectively modulate resting state resonant bands of neural synchrony and to investigate its influence on motor and non-motor behaviors in PD and other neuropsychiatric diseases.

  2. History of grating images

    Science.gov (United States)

    Iwata, Fujio

    2001-06-01

    Toppan Printing Co., Ltd. originated the name of 'grating image'. It means an image that consists of diffraction grating dots that look similar to the halftone dots of conventional printing. We proposed this new display method using simple gratings in order to enhance the visual effects when illumination is made by a fluorescent lamp. We considered the use of simple gratings as elemental dots, and used a number of elemental dots to display a 2D image. This method produces an effect something like the halftone dots of printing. The grating image technology grows from its starting to become able to produce 3D images and a 3D-video system using an electron beam grating-writing system.

  3. GlossmarkTM Technology:An Innovative Digital Watermark

    Institute of Scientific and Technical Information of China (English)

    Beilei Xu; Shen-ge Wang; Chuheng Liu

    2004-01-01

    GlossmarkTM technology is a digital watermark process that embeds a visually striking gloss image within a high quality color print without the need of special papers or toners. It utilizes the angular dependence of gloss to create a differential-gloss image through the modulation of halftone structures. Both the primary image and the embedded GlossmarkTM image can be distinctively viewed from different perspectives with little interference. The strong directional nature of the gloss and the subtle halftone modulation process make GlossmarkTM images very difficult to detect by a scanner and even more challenging to reproduce through scanning and printing. The GlossmarkTM technology is ideally suitable for document authentication and graphics enhancement. Its digital implementation provides a capability to embed variable data as digital watermarks into individual prints quickly and economically.

  4. Pulsed laser ablation of polymers for display applications

    Science.gov (United States)

    Pedder, James E. A.; Holmes, Andrew S.; Booth, Heather J.

    2008-02-01

    Laser micromachining by ablation is a well established technique used for the production of 2.5D and 3D features in a wide variety of materials. The fabrication of stepped, multi-level, structures can be achieved using a number of binary mask projection techniques using excimer lasers. Alternatively, direct-writing of complex 2.5D features can easily be achieved with solid-state lasers. Excimer laser ablation using half-tone masks allows almost continuous surface relief and the generation of features with low surface roughness. We have developed techniques to create large arrays of repeating micro-optical structures on polymer substrates. Here, we show our recent developments in laser structuring with the combination of half-tone and binary mask techniques.

  5. Modeling coverage-dependent ink thickness in ink-jet printing.

    Science.gov (United States)

    Coppel, Ludovic G; Slavuj, Radovan; Hardeberg, Jon Yngve

    2016-02-10

    We propose a simple extension of the Murray-Davis halftone reflectance model that accounts for the change of ink dot reflectance due to ink spreading. Significant improvement of the prediction accuracy is obtained for a range of paper substrates and printer combinations compared to the classical Yule-Nielsen and Clapper-Yule models. The results show that ink dot thickness dependency is the main factor limiting the validity of the Murray-Davis model and that optical dot gain can be neglected when the model is calibrated for one specific printer, ink, and substrate combination. The proposed model provides a better understanding of the reflectance from halftone prints that contributes to the development of physical models for simpler and faster printer calibration to different substrates.

  6. Profile of Neuropsychiatric Symptoms in Parkinson's Disease: Surgical Candidates Compared to Controls

    NARCIS (Netherlands)

    Lamberti, V.M.; Pereira, B.; Lhommee, E.; Bichon, A.; Schmitt, E.; Pelissier, P.; Kistner, A.; Fraix, V.; Castrioto, A.; Esselink, R.A.; Durif, F.; Krack, P.

    2016-01-01

    BACKGROUND: Subthalamic nucleus deep brain stimulation (STN-DBS) improves motor symptoms of Parkinson's disease (PD) and motor complications of dopaminergic treatment. Whether STN-DBS should be considered when PD patients experience neuropsychiatric symptoms is controversial. Lack of systematic beha

  7. Deep brain stimulation of the subthalamic nucleus and globus pallidus internus for advanced Parkinson’s disease

    NARCIS (Netherlands)

    Odekerken, V.J.J.

    2016-01-01

    Deep Brain Stimulation (DBS) for Parkinson’s disease is a treatment option in patients with medication-induced motor response fluctuations, when medication schedule adjustments are no longer able to sustain optimal functioning in daily life. DBS mainly improves motor symptoms that initially responde

  8. Cost-effectiveness of neurostimulation in Parkinson's disease with early motor complications

    NARCIS (Netherlands)

    Dams, J.; Balzer-Geldsetzer, M.; Siebert, U.; Deuschl, G.; Schuepbach, W.M.; Krack, P.; Timmermann, L.; Schnitzler, A.; Reese, J.P.; Dodel, R.; Post, B.

    2016-01-01

    BACKGROUND: Recent research efforts have focused on the effects of deep brain stimulation of the subthalamic nucleus (STN DBS) for selected patients with mild-to-moderate PD experiencing motor complications. OBJECTIVES: We assessed the cost utility of subthalamic DBS compared with the best medical t

  9. Increase in body weight is a non-motor side effect of deep brain stimulation of the subthalamic nucleus in Parkinson's disease.

    Science.gov (United States)

    Novakova, Lucie; Ruzicka, Evzen; Jech, Robert; Serranova, Tereza; Dusek, Petr; Urgosik, Dusan

    2007-02-01

    Deep brain stimulation of the subthalamic nucleus (DBS STN) is an effective treatment method in advanced Parkinson's disease (PD) providing marked improvement of its major motor symptoms. In addition, non-motor effects have been reported including weight gain in PD patients after DBS STN. Using retrospective survey, we aimed to evaluate weight changes in our patients with advanced PD treated with DBS STN. We inquired 25 PD patients (16 men, 9 women), of mean age 55 (42-65) years, mean PD duration 15 (9-21) years, who previously received bilateral DBS STN. We obtained valid data from 23 patients. In the first survey, 1 to 45 months after DBS, weight gain was found in all patients comparing to pre-DBS period. The mean increase was 9.4 kg (from 1 to 25 kg). The patients' mean body mass index (BMI) increased from 23.7 to 27.0 kg/m2, i.e. by 3.3 kg/m2 (+2 to +6.1 kg/m2). In the repeated survey one year later, in 12 of the patients body weight moderately decreased, 3 did not change, and 6 patients further increased their weight. Possible explanations of body weight gain after DBS STN include a reduction of energy output related to elimination of dyskinesias, improved alimentation or direct influence on function of lateral hypothalamus by DBS STN.

  10. Functional Magnetic Resonance Imaging of Electrical and Optogenetic Deep Brain Stimulation at the Rat Nucleus Accumbens

    Science.gov (United States)

    Albaugh, Daniel L.; Salzwedel, Andrew; van den Berge, Nathalie; Gao, Wei; Stuber, Garret D.; Shih, Yen-Yu Ian

    2016-09-01

    Deep brain stimulation of the nucleus accumbens (NAc-DBS) is an emerging therapy for diverse, refractory neuropsychiatric diseases. Although DBS therapy is broadly hypothesized to work through large-scale neural modulation, little is known regarding the neural circuits and networks affected by NAc-DBS. Using a healthy, sedated rat model of NAc-DBS, we employed both evoked- and functional connectivity (fc) MRI to examine the functional circuit and network changes achieved by electrical NAc stimulation. Optogenetic-fMRI experiments were also undertaken to evaluate the circuit modulation profile achieved by selective stimulation of NAc neurons. NAc-DBS directly modulated neural activity within prefrontal cortex and a large number of subcortical limbic areas (e.g., amygdala, lateral hypothalamus), and influenced functional connectivity among sensorimotor, executive, and limbic networks. The pattern and extent of circuit modulation measured by evoked-fMRI was relatively insensitive to DBS frequency. Optogenetic stimulation of NAc cell bodies induced a positive fMRI signal in the NAc, but no other detectable downstream responses, indicating that therapeutic NAc-DBS might exert its effect through antidromic stimulation. Our study provides a comprehensive mapping of circuit and network-level neuromodulation by NAc-DBS, which should facilitate our developing understanding of its therapeutic mechanisms of action.

  11. Fornix deep brain stimulation induced long-term spatial memory independent of hippocampal neurogenesis.

    Science.gov (United States)

    Hescham, Sarah; Temel, Yasin; Schipper, Sandra; Lagiere, Mélanie; Schönfeld, Lisa-Maria; Blokland, Arjan; Jahanshahi, Ali

    2017-03-01

    Deep brain stimulation (DBS) is an established symptomatic treatment modality for movement disorders and constitutes an emerging therapeutic approach for the treatment of memory impairment. In line with this, fornix DBS has shown to ameliorate cognitive decline associated with dementia. Nonetheless, mechanisms mediating clinical effects in demented patients or patients with other neurological disorders are largely unknown. There is evidence that DBS is able to modulate neurophysiological activity in targeted brain regions. We therefore hypothesized that DBS might be able to influence cognitive function via activity-dependent regulation of hippocampal neurogenesis. Using stimulation parameters, which were validated to restore memory loss in a previous behavioral study, we here assessed long-term effects of fornix DBS. To do so, we injected the thymidine analog, 5-bromo-2'-deoxyuridine (BrdU), after DBS and perfused the animals 6.5 weeks later. A week prior to perfusion, memory performance was assessed in the water maze. We found that acute stimulation of the fornix improved spatial memory performance in the water maze when the probe trial was performed 1 h after the last training session. However, no evidence for stimulation-induced neurogenesis was found in fornix DBS rats when compared to sham. Our results suggest that fornix DBS improves memory functions independent of hippocampal neurogenesis, possibly through other mechanisms such as synaptic plasticity and acute neurotransmitter release.

  12. LCMV Beamforming for a Novel Wireless Local Positioning System: Nonstationarity and Cyclostationarity Analysis

    Directory of Open Access Journals (Sweden)

    Seyed A. Zekavat

    2007-01-01

    Full Text Available This paper investigates the implementation of a novel wireless local positioning system (WLPS. WLPS main components are: (a a dynamic base station (DBS and (b a transponder, both mounted on mobiles. The DBS periodically transmits ID request signals. As soon as the transponder detects the ID request signal, it sends its ID (a signal with a limited duration back to the DBS. Hence, the DBS receives noncontinuous signals periodically transmitted by the transponder. The noncontinuous nature of the WLPS leads to nonstationary received signals at the DBS receiver, while the periodic signal structure leads to the fact that the DBS received signal is also cyclostationary. This work discusses the implementation of linear constrained minimum variance (LCMV beamforming at the DBS receiver. We demonstrate that the nonstationarity of the received signal causes the sample covariance to be an inaccurate estimate of the true signal covariance. The errors in this covariance estimate limit the applicability of LCMV beamforming. A modified covariance matrix estimator, which exploits the cyclostationarity property of WLPS system is introduced to solve the nonstationarity problem. The cyclostationarity property is discussed in detail theoretically and via simulations. It is shown that the modified covariance matrix estimator significantly improves the DBS performance. The proposed technique can be applied to periodic-sense signaling structures such as the WLPS, RFID, and reactive sensor networks.

  13. Deep brain stimulation of pedunculopontine tegmental nucleus: role in sleep modulation in advanced Parkinson disease patients: one-year follow-up.

    Science.gov (United States)

    Peppe, Antonella; Pierantozzi, Mariangela; Baiamonte, Valentina; Moschella, Vincenzo; Caltagirone, Carlo; Stanzione, Paolo; Stefani, Alessandro

    2012-12-01

    Sleep disorders are frequent non-motor symptoms in Parkinson disease (PD), probably due to multifactorial pathogeneses including disease progression, dopaminergic drugs, or concomitant illness. In recent years, the pedunculopontine tegmental (PPTg) nucleus has been considered a surgical target for deep brain stimulation (DBS) in advanced PD patients. As it is involved in controlling the sleep-wake cycle, we investigated the long-lasting effects of PPTg-DBS on the sleep of five PD patients implanted in both the PPTg and the subthalamic nucleus (STN) by rating two subjective clinical scales for sleep: the Parkinson's Disease Sleep Scale (PDSS), and the Epworth Sleepiness Scale (ESS). Sleep scales were administered a week before surgery (T0), three months after DBS (T1), and one year later (T2). In this study, STN-DBS was kept constantly in ON, and three different patterns of PPTg-DBS were investigated: STN-ON (PPTg switched off); PPTg-ON (PPTg stimulated 24 h/day); PPTg-cycle (PPTg stimulated only at night). In post-surgery follow-up, PD patients reported a marked improvement of sleep quality in all DBS conditions. In particular, stimulation of the PPTg nucleus produced not only a remarkable long-term improvement of nighttime sleep, but unlike STN-DBS, also produced significant amelioration of daytime sleepiness. Our study suggests that PPTg-DBS plays an important role in reorganizing regular sleep in PD patients.

  14. Dried blood spot analysis for therapeutic drug monitoring of pazopanib.

    Science.gov (United States)

    de Wit, Djoeke; den Hartigh, Jan; Gelderblom, Hans; Qian, Yanwen; den Hollander, Margret; Verheul, Henk; Guchelaar, Henk-Jan; van Erp, Nielka P

    2015-12-01

    Dried blood spot (DBS) sampling is potentially a more patient-friendly and flexible alternative to venous sampling of pazopanib. This study determined the agreement between pazopanib DBS and plasma concentrations to facilitate implementation of pazopanib DBS sampling into clinical practice. Paired DBS and plasma samples were collected in 12 patients. Pazopanib plasma concentrations were calculated from DBS concentrations using the formula: plasma concentration = DBSconcentration /(1 - hematocrit). Passing-Bablok and Bland-Altman analyses were used to determine the agreement between calculated and measured plasma concentrations. We predefined a clinical acceptance limit of 25% for the Bland-Altman analysis. Passing-Bablok analysis showed a small constant (intercept estimate, -8.53 [95%CI, -12.22 to -4.41]) and slightly proportional (slope estimate, 1.15 [95%CI, 1.04-1.24]) bias between calculated and measured concentrations. This bias was clinically nonrelevant, as shown by Bland-Altman analysis; the mean ratio of calculated to measured concentrations was 0.94 (95%CI, 0.65-1.23). The clinical acceptance limits were well within these 95% limits of agreement. More specifically, 92.6% of the data points were within the predefined acceptance limits. Pazopanib plasma concentrations can be accurately calculated from DBS concentrations. Although validation of DBS cards prepared by patients themselves is required, these results show that DBS sampling can be used to monitor pazopanib therapy in clinical practice.

  15. Pitch Variability in Patients with Parkinson's Disease: Effects of Deep Brain Stimulation of Caudal Zona Incerta and Subthalamic Nucleus

    Science.gov (United States)

    Karlsson, Fredrik; Olofsson, Katarina; Blomstedt, Patric; Linder, Jan; van Doorn, Jan

    2013-01-01

    Purpose: The purpose of the present study was to examine the effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) and the caudal zona incerta (cZi) pitch characteristics of connected speech in patients with Parkinson's disease (PD). Method: The authors evaluated 16 patients preoperatively and 12 months after DBS surgery. Eight…

  16. Evidence from a rare case-study for Hebbian-like changes in structural connectivity induced by long-term deep brain stimulation

    Directory of Open Access Journals (Sweden)

    Tim J Van Hartevelt

    2015-06-01

    Full Text Available It is unclear whether Hebbian-like learning occurs at the level of long-range white matter connections in humans, i.e. where measurable changes in structural connectivity are correlated with changes in functional connectivity. However, the behavioral changes observed after deep brain stimulation (DBS suggest the existence of such Hebbian-like mechanisms occurring at the structural level with functional consequences. In this rare case study, we obtained the full network of white matter connections of one patient with Parkinson's disease before and after long-term DBS and combined it with a computational model of ongoing activity to investigate the effects of DBS-induced long-term structural changes. The results show that the long-term effects of DBS on resting-state functional connectivity is best obtained in the computational model by changing the structural weights from the subthalamic nucleus to the putamen and the thalamus in a Hebbian-like manner. Moreover, long-term DBS also significantly changed the structural connectivity towards normality in terms of model-based measures of segregation and integration of information processing, two key concepts of brain organization. This novel approach using computational models to model the effects of Hebbian-like changes in structural connectivity allowed us to causally identify the possible underlying neural mechanisms of long-term DBS using rare case study data. In time, this could help predict the efficacy of individual DBS targeting and identify novel DBS targets.

  17. The application of deep brain stimulation in the treatment of psychiatric disorders

    NARCIS (Netherlands)

    Graat, Ilse; Figee, Martijn; Denys, D.

    2017-01-01

    Deep brain stimulation (DBS) is a last-resort treatment for neurological and psychiatric disorders that are refractory to standard treatment. Over the last decades, the progress of DBS in psychiatry has been slower than in neurology, in part owing to the heterogenic symptomatology and complex

  18. Descomposición fotoquímica de soluciones acuosas de dodecilbenceno sulfonato sódico en un fotoreactor anular contínuo de mezcla perfecta

    OpenAIRE

    Costa López, José; Esplugas Vidal, Santiago; Ibarz Ribas, Alberto

    1980-01-01

    La fotodescomposición de dodecilbencenosulfato sódico (DBS) se ha estudiado como un proceso de purificación del agua. Soluciones acuosas de DBS han sido irradiadas en un fotorreactor anular de mezcla perfecta, aplicándose el modelo de radiación cilíndrico esférico extenso.

  19. Performance of an app measuring spot quality in dried blood spot sampling

    NARCIS (Netherlands)

    Veenhof, Herman

    2016-01-01

    Introduction: The Dried Blood Spot sampling (DBS) method gives patients and health care workers the opportunity for remote sampling using a drop of blood from a fingerprick on a sampling card which can be send to the laboratory by mail. Laboratory analysts frequently reject DBS samples because of

  20. Subthalamic Nucleus Deep Brain Stimulation Changes Velopharyngeal Control in Parkinson's Disease

    Science.gov (United States)

    Hammer, Michael J.; Barlow, Steven M.; Lyons, Kelly E.; Pahwa, Rajesh

    2011-01-01

    Purpose: Adequate velopharyngeal control is essential for speech, but may be impaired in Parkinson's disease (PD). Bilateral subthalamic nucleus deep brain stimulation (STN DBS) improves limb function in PD, but the effects on velopharyngeal control remain unknown. We tested whether STN DBS would change aerodynamic measures of velopharyngeal…

  1. The International Deep Brain Stimulation Registry and Database for Gilles de la Tourette Syndrome: How Does It Work?

    Science.gov (United States)

    Deeb, Wissam; Rossi, Peter J.; Porta, Mauro; Visser-Vandewalle, Veerle; Servello, Domenico; Silburn, Peter; Coyne, Terry; Leckman, James F.; Foltynie, Thomas; Hariz, Marwan; Joyce, Eileen M.; Zrinzo, Ludvic; Kefalopoulou, Zinovia; Welter, Marie-Laure; Karachi, Carine; Mallet, Luc; Houeto, Jean-Luc; Shahed-Jimenez, Joohi; Meng, Fan-Gang; Klassen, Bryan T.; Mogilner, Alon Y.; Pourfar, Michael H.; Kuhn, Jens; Ackermans, L.; Kaido, Takanobu; Temel, Yasin; Gross, Robert E.; Walker, Harrison C.; Lozano, Andres M.; Khandhar, Suketu M.; Walter, Benjamin L.; Walter, Ellen; Mari, Zoltan; Changizi, Barbara K.; Moro, Elena; Baldermann, Juan C.; Huys, Daniel; Zauber, S. Elizabeth; Schrock, Lauren E.; Zhang, Jian-Guo; Hu, Wei; Foote, Kelly D.; Rizer, Kyle; Mink, Jonathan W.; Woods, Douglas W.; Gunduz, Aysegul; Okun, Michael S.

    2016-01-01

    Tourette Syndrome (TS) is a neuropsychiatric disease characterized by a combination of motor and vocal tics. Deep brain stimulation (DBS), already widely utilized for Parkinson's disease and other movement disorders, is an emerging therapy for select and severe cases of TS that are resistant to medication and behavioral therapy. Over the last two decades, DBS has been used experimentally to manage severe TS cases. The results of case reports and small case series have been variable but in general positive. The reported interventions have, however, been variable, and there remain non-standardized selection criteria, various brain targets, differences in hardware, as well as variability in the programming parameters utilized. DBS centers perform only a handful of TS DBS cases each year, making large-scale outcomes difficult to study and to interpret. These limitations, coupled with the variable effect of surgery, and the overall small numbers of TS patients with DBS worldwide, have delayed regulatory agency approval (e.g., FDA and equivalent agencies around the world). The Tourette Association of America, in response to the worldwide need for a more organized and collaborative effort, launched an international TS DBS registry and database. The main goal of the project has been to share data, uncover best practices, improve outcomes, and to provide critical information to regulatory agencies. The international registry and database has improved the communication and collaboration among TS DBS centers worldwide. In this paper we will review some of the key operation details for the international TS DBS database and registry. PMID:27199634

  2. Electronic Conductivity of Polypyrrole−Dodecyl Benzene Sulfonate Complexes

    DEFF Research Database (Denmark)

    West, Keld; Bay, Lasse; Nielsen, Martin Meedom

    2004-01-01

    The electronic conductivity of the electroactive polymer polypyrrole-dodecyl benzene sulfonate (PPy-DBS) has been characterized as function of the redox level. The polymer was synthesized with different isomers of the dopant anions: the common mixed DBS tenside and three well-defined synthetic...

  3. Me, Myself and My Brain Implant: Deep Brain Stimulation Raises Questions of Personal Authenticity and Alienation.

    Science.gov (United States)

    Kraemer, Felicitas

    2013-01-01

    In this article, I explore select case studies of Parkinson patients treated with deep brain stimulation (DBS) in light of the notions of alienation and authenticity. While the literature on DBS has so far neglected the issues of authenticity and alienation, I argue that interpreting these cases in terms of these concepts raises new issues for not only the philosophical discussion of neuro-ethics of DBS, but also for the psychological and medical approach to patients under DBS. In particular, I suggest that the experience of alienation and authenticity varies from patient to patient with DBS. For some, alienation can be brought about by neurointerventions because patients no longer feel like themselves. But, on the other hand, it seems alienation can also be cured by DBS as other patients experience their state of mind as authentic under treatment and retrospectively regard their former lives without stimulation as alienated. I argue that we must do further research on the relevance of authenticity and alienation to patients treated with DBS in order to gain a deeper philosophical understanding, and to develop the best evaluative criterion for the behavior of DBS patients.

  4. What parents think and feel about deep brain stimulation in paediatric secondary dystonia including cerebral palsy: A qualitative study of parental decision-making.

    Science.gov (United States)

    Austin, Allana; Lin, Jean-Pierre; Selway, Richard; Ashkan, Keyoumars; Owen, Tamsin

    2017-01-01

    Dystonia is characterised by involuntary movements and postures. Deep Brain Stimulation (DBS) is effective in reducing dystonic symptoms in primary dystonia in childhood and to lesser extent in secondary dystonia. How families and children decide to choose DBS surgery has never been explored. To explore parental decision-making for DBS in paediatric secondary dystonia. Data was gathered using semi-structured interviews with eight parents of children with secondary dystonia who had undergone DBS. Interviews were analysed using Interpretative Phenomenological Analysis. For all parents the decision was viewed as significant, with life altering consequences for the child. These results suggested that parents were motivated by a hope for a better life and parental duty. This was weighed against consideration of risks, what the child had to lose, and uncertainty of DBS outcome. Decisions were also influenced by the perspectives of their child and professionals. The decision to undergo DBS was an ongoing process for parents, who ultimately were struggling in the face of uncertainty whilst trying to do their best as parents for their children. These findings have important clinical implications given the growing referrals for consideration of DBS childhood dystonia, and highlights the importance of further quantitative research to fully establish the efficacy of DBS in secondary dystonia to enhance informed decision-making. Copyright © 2016. Published by Elsevier Ltd.

  5. Comparison of S. stercoralis serology performed on dried blood spots and on conventional serum samples.

    Directory of Open Access Journals (Sweden)

    Fabio Formenti

    2016-11-01

    Full Text Available Background. Dried blood spots (DBS are used for epidemiological surveys on infectious diseases in settings with limited resources. In fact, DBS can help to overcome logistic difficulties for the collection, transport and storage of biological specimens. Objective. To evaluate the accuracy of S. stercoralis serology performed on DBS. Methods. A survey was proposed to children attending a school in the village of Borbon, Ecuador, and to their parents/guardians. Each participant gave consent to the collection of both serum and DBS specimens. DBS absorbed on filter papers were analyzed with a commercially-available ELISA test for Strongyloides stercoralis antibodies, in parallel to the standard serology. The agreement between the two methods was assessed through the Cohen’s kappa coefficient. Results. The study sample was composed by 174 children and 61 adults, for a total of 235 serum and 235 DBS samples. The serology was positive in 31/235 (13% serum samples, and in 27/235 (11% DBS: 4 samples resulted discordant (positive at standard serology. Cohen’s kappa resulted 0.921 (95% CI 0.845 - 0.998, indicating a high rate of concordance. Conclusion. DBS are suitable for in field-surveys requiring serological testing for S. stercoralis.

  6. Comparison of S. stercoralis Serology Performed on Dried Blood Spots and on Conventional Serum Samples

    Science.gov (United States)

    Formenti, Fabio; Buonfrate, Dora; Prandi, Rosanna; Marquez, Monica; Caicedo, Cintia; Rizzi, Eleonora; Guevara, Angel G.; Vicuña, Yosselin; Huerlo, Francisco R.; Perandin, Francesca; Bisoffi, Zeno; Anselmi, Mariella

    2016-01-01

    Background: Dried blood spots (DBS) are used for epidemiological surveys on infectious diseases in settings where limited resources are available. In fact, DBS can help to overcome logistic difficulties for the collection, transport and storage of biological specimens. Objective: To evaluate the accuracy of Strongyloides stercoralis serology performed on DBS. Methods: A survey was proposed to children attending a school in the village of Borbon, Ecuador, and to their parents/guardians. Each participant gave consent to the collection of both serum and DBS specimens. DBS absorbed on filter papers were analyzed with a commercially available ELISA test for S. stercoralis antibodies, as well as with standard serology. The agreement between the two methods was assessed through the Cohen’s kappa coefficient. Results: The study sample was composed of 174 children and 61 adults, for a total of 235 serum and 235 DBS samples. The serology was positive in 31/235 (13%) serum samples, and in 27/235 (11%) DBS: 4 samples resulted discordant (positive at standard serology). Cohen’s kappa coefficient was 0.921 (95% CI 0.845 – 0.998), indicating a high rate of concordance. Conclusion: DBS are suitable for in field-surveys requiring serological testing for S. stercoralis. PMID:27877170

  7. SRPDB

    DEFF Research Database (Denmark)

    Rosenblad, Magnus Alm; Gorodkin, Jan; Knudsen, Bjarne

    2003-01-01

    The Signal Recognition Particle Database (SRPDB) at http://psyche.uthct.edu/dbs/SRPDB/SRPDB.html and http://bio.lundberg.gu.se/dbs/SRPDB/SRPDB.html assists in the better understanding of the structure and function of the signal recognition particle (SRP), a ribonucleoprotein complex that recognizes...

  8. Application of a Null-Beamformer to Source Localisation in MEG Data of Deep Brain Stimulation

    DEFF Research Database (Denmark)

    Mohseni, Hamid R.; Kringelbach, Morten L.; Smith, Penny Probert;

    2010-01-01

    to reconstruct the neural activity of interest is challenging because of interference to the signal from the DBS device. We demonstrate that a null-beamformer can be used to localise neural activity despite artefacts caused by the presence of DBS electrodes and stimulus pulses. We subsequently verified...

  9. Situating the self: understanding the effects of deep brain stimulation

    NARCIS (Netherlands)

    Dings, R.P.J.M.; Bruin, L.C. de

    2015-01-01

    The article proposes a theoretical model to account for changes in self due to Deep Brain Stimulation (DBS). First, we argue that most existing models postulate a very narrow conception of self, and thus fail to capture the full range of potentially relevant DBS-induced changes. Second, building on

  10. Deep Brain Stimulation for Movement Disorders of Basal Ganglia Origin: Restoring Function or Functionality?

    Science.gov (United States)

    Wichmann, Thomas; DeLong, Mahlon R

    2016-04-01

    Deep brain stimulation (DBS) is highly effective for both hypo- and hyperkinetic movement disorders of basal ganglia origin. The clinical use of DBS is, in part, empiric, based on the experience with prior surgical ablative therapies for these disorders, and, in part, driven by scientific discoveries made decades ago. In this review, we consider anatomical and functional concepts of the basal ganglia relevant to our understanding of DBS mechanisms, as well as our current understanding of the pathophysiology of two of the most commonly DBS-treated conditions, Parkinson's disease and dystonia. Finally, we discuss the proposed mechanism(s) of action of DBS in restoring function in patients with movement disorders. The signs and symptoms of the various disorders appear to result from signature disordered activity in the basal ganglia output, which disrupts the activity in thalamocortical and brainstem networks. The available evidence suggests that the effects of DBS are strongly dependent on targeting sensorimotor portions of specific nodes of the basal ganglia-thalamocortical motor circuit, that is, the subthalamic nucleus and the internal segment of the globus pallidus. There is little evidence to suggest that DBS in patients with movement disorders restores normal basal ganglia functions (e.g., their role in movement or reinforcement learning). Instead, it appears that high-frequency DBS replaces the abnormal basal ganglia output with a more tolerable pattern, which helps to restore the functionality of downstream networks.

  11. Strong Correlation Between Concentrations of Tenofovir (TFV) Emtricitabine (FTC) in Hair and TFV Diphosphate and FTC Triphosphate in Dried Blood Spots in the iPrEx Open Label Extension: Implications for Pre-exposure Prophylaxis Adherence Monitoring

    Science.gov (United States)

    Gandhi, Monica; Glidden, David V.; Liu, Albert; Anderson, Peter L.; Horng, Howard; Defechereux, Patricia; Guanira, Juan V.; Grinsztejn, Beatriz; Chariyalertsak, Suwat; Bekker, Linda-Gail; Grant, Robert M.

    2015-01-01

    Self-reported adherence to pre-exposure prophylaxis (PrEP) has limitations, raising interest in pharmacologic monitoring. Drug concentrations in hair and dried blood spots (DBS) are used to assess long-term-exposure; hair shipment/storage occurs at room temperature. The iPrEx Open Label Extension collected DBS routinely, with opt-in hair collection; concentrations were measured with liquid chromatography/tandem mass spectrometry. In 806 hair-DBS pairs, tenofovir (TFV) hair levels and TFV diphosphate (DP) in DBS were strongly correlated (Spearman coefficient r = 0.734; P < .001), as were hair TFV/DBS emtricitabine (FTC) triphosphate (TP) (r = 0.781; P < .001); hair FTC/DBS TFV-DP (r = 0.74; P < .001); hair FTC/DBS FTC-TP (r = 0.587; P < .001). Drug detectability was generally concordant by matrix. Hair TFV/FTC concentrations correlate strongly with DBS levels, which are predictive of PrEP outcomes. PMID:25895984

  12. Whole-genome amplified DNA from stored dried blood spots is reliable in high resolution melting curve and sequencing analysis

    DEFF Research Database (Denmark)

    Winkel, Bo G; Hollegaard, Mads Vilhelm; Olesen, Morten S;

    2011-01-01

    The use of dried blood spots (DBS) samples in genomic workup has been limited by the relative low amounts of genomic DNA (gDNA) they contain. It remains to be proven that whole genome amplified DNA (wgaDNA) from stored DBS samples, constitutes a reliable alternative to gDNA.We wanted to compare m...

  13. The Dominance Behavioral System and Psychopathology: Evidence from Self-Report, Observational, and Biological Studies

    Science.gov (United States)

    Johnson, Sheri L.; Leedom, Liane J.; Muhtadie, Luma

    2012-01-01

    The dominance behavioral system (DBS) can be conceptualized as a biologically based system that guides dominance motivation, dominant and subordinate behavior, and responsivity to perceptions of power and subordination. A growing body of research suggests that problems with the DBS are evident across a broad range of psychopathologies. We begin by…

  14. European clinical guidelines for Tourette syndrome and other tic disorders. Part IV : deep brain stimulation

    NARCIS (Netherlands)

    Mueller-Vahl, Kirsten R.; Cath, Danielle C.; Cavanna, Andrea E.; Dehning, Sandra; Porta, Mauro; Robertson, Mary M.; Visser-Vandewalle, Veerle

    2011-01-01

    Ten years ago deep brain stimulation (DBS) has been introduced as an alternative and promising treatment option for patients suffering from severe Tourette syndrome (TS). It seemed timely to develop a European guideline on DBS by a working group of the European Society for the Study of Tourette Synd

  15. 47 CFR 25.148 - Licensing provisions for the Direct Broadcast Satellite Service.

    Science.gov (United States)

    2010-10-01

    ... authorized orbital location. This requirement does not apply to DBS satellites authorized to operate at the 61.5° W.L. orbital location. DBS applicants seeking to operate from locations other than 61.5° W.L... criteria and technical characteristics contained in Appendices 30 and 30A of the ITU's Radio...

  16. Functional Magnetic Resonance Imaging of Electrical and Optogenetic Deep Brain Stimulation at the Rat Nucleus Accumbens

    Science.gov (United States)

    Albaugh, Daniel L.; Salzwedel, Andrew; Van Den Berge, Nathalie; Gao, Wei; Stuber, Garret D.; Shih, Yen-Yu Ian

    2016-01-01

    Deep brain stimulation of the nucleus accumbens (NAc-DBS) is an emerging therapy for diverse, refractory neuropsychiatric diseases. Although DBS therapy is broadly hypothesized to work through large-scale neural modulation, little is known regarding the neural circuits and networks affected by NAc-DBS. Using a healthy, sedated rat model of NAc-DBS, we employed both evoked- and functional connectivity (fc) MRI to examine the functional circuit and network changes achieved by electrical NAc stimulation. Optogenetic-fMRI experiments were also undertaken to evaluate the circuit modulation profile achieved by selective stimulation of NAc neurons. NAc-DBS directly modulated neural activity within prefrontal cortex and a large number of subcortical limbic areas (e.g., amygdala, lateral hypothalamus), and influenced functional connectivity among sensorimotor, executive, and limbic networks. The pattern and extent of circuit modulation measured by evoked-fMRI was relatively insensitive to DBS frequency. Optogenetic stimulation of NAc cell bodies induced a positive fMRI signal in the NAc, but no other detectable downstream responses, indicating that therapeutic NAc-DBS might exert its effect through antidromic stimulation. Our study provides a comprehensive mapping of circuit and network-level neuromodulation by NAc-DBS, which should facilitate our developing understanding of its therapeutic mechanisms of action. PMID:27601003

  17. Successful deep brain stimulation of the nucleus accumbens in severe alcohol dependence is associated with changed performance monitoring

    NARCIS (Netherlands)

    Kuhn, J.; Gründler, T.O.J.; Bauer, R.; Huff, W.; Fischer, A.G.; Lenartz, D.; Maarouf, M.; Bührle, C.; Klosterkötter, J.; Ullsperger, M.; Sturm, V.

    2011-01-01

    Following recent advances in neuromodulation therapy for mental disorders, we treated one patient with severe alcohol addiction with deep brain stimulation (DBS) of the nucleus accumbens (NAc). Before and one year following the surgery, we assessed the effects of DBS within the NAc on the addiction

  18. Successful deep brain stimulation of the nucleus accumbens in severe alcohol dependence is associated with changed performance monitoring

    NARCIS (Netherlands)

    Kuhn, J.; Gründler, T.O.J.; Bauer, R.; Huff, W.; Fischer, A.G.; Lenartz, D.; Maarouf, M.; Bührle, C.; Klosterkötter, J.; Ullsperger, M.; Sturm, V.

    2011-01-01

    Following recent advances in neuromodulation therapy for mental disorders, we treated one patient with severe alcohol addiction with deep brain stimulation (DBS) of the nucleus accumbens (NAc). Before and one year following the surgery, we assessed the effects of DBS within the NAc on the addiction

  19. Extending Kubelka-Munk's Theory with Lateral Light Scattering

    OpenAIRE

    Mourad, Safer; Emmel, Patrick; Simon, Klaus; Hersch, Roger David

    2001-01-01

    Due to its simplicity, the theory of KUBELKA-MUNK [1] has found a wide acceptance for modeling the optical properties of light scattering materials. However, the concept is not explicitly adapted to predict halftone prints on paper. In this respect, a recent improvement was given by BERG. Our approach is an extension of BERG'S model in order to reduce the gap between the mathematical description of the paper's point spread function and the experimental results of simple reflectance measurements.

  20. Document watermarking based on digital holographic principle

    CERN Document Server

    Kim, Chol-Su; Im, Song-Jin

    2013-01-01

    A new method for document watermarking based on the digital Fourier hologram is proposed. It applies the methods of digital image watermarking based on holographic principle presented previously in several papers into printed documents. Experimental results show that the proposed method can not only meet the demand on invisibility, robustness and non-reproducibility of the document watermark, and but also has other advantages compared with the conventional methods for document securities such as embossed hologram, Lippmann photograph and halftone modulation.

  1. Wavelet transform based watermark for digital images.

    Science.gov (United States)

    Xia, X G; Boncelet, C; Arce, G

    1998-12-07

    In this paper, we introduce a new multiresolution watermarking method for digital images. The method is based on the discrete wavelet transform (DWT). Pseudo-random codes are added to the large coefficients at the high and middle frequency bands of the DWT of an image. It is shown that this method is more robust to proposed methods to some common image distortions, such as the wavelet transform based image compression, image rescaling/stretching and image halftoning. Moreover, the method is hierarchical.

  2. Initial Conceptualization and Characterization of a Navy Automated Publishing System. Volume 1. Executive Summary.

    Science.gov (United States)

    1980-01-01

    Comunications 21 3.3.6 Output 21 4. Conclusions 22 S. hecemendat ions 23 6. References 26 Voluse 2. WCHNICAL REPORT Volume 3. APPENDICES iii LUST OF...1977, all line art, half-tones and screen tint backgrounds (including colored screens and spot color) have been digitized and stored in the text... digitize and transmit color separations -- but this will come within the next few months. In early 1979, because of the cost of the equipment used to

  3. Packaging Printing Today

    OpenAIRE

    Bolanča, Stanislav; Majnarić, Igor; Golubović, Kristijan

    2015-01-01

    Printing packaging covers today about 50% of all the printing products. Among the printing products there are printing on labels, printing on flexible packaging, printing on folding boxes, printing on the boxes of corrugated board, printing on glass packaging, synthetic and metal ones. The mentioned packaging are printed in flexo printing technique, offset printing technique, intaglio halftone process, silk – screen printing, ink ball printing, digital printing and hybrid print...

  4. Gray tone image watermarking with complementary computer generated holography.

    Science.gov (United States)

    Martinez, Christophe; Laulagnet, Fabien; Lemonnier, Olivier

    2013-07-01

    We present herein an original approach for the watermarking of holograms in gray tone images for use in microscopic halftone image archiving. Our concept is based on the principle of complementary holography presented in a previous contribution. The efficiency of the concept is evaluated theoretically and experimentally. We demonstrate the interest of elliptical diffraction patterns as an alternative to the usual rectangular diffraction patterns and confirm the subsidiary role of the hologram amplitude in the hologram recovery process.

  5. Lossless/Lossy Compression of Bi-level Images

    DEFF Research Database (Denmark)

    Martins, Bo; Forchhammer, Søren

    1997-01-01

    .g. halftoning and text without any segmentation of the image. The decoding is analoguous to the decoder of JBIG which means that software implementations easily have a through-put of 1 Mpixels per second.In general, the flipping method can target the lossy image for a given not-too-large distortion ornot-too......, an emerging international standard for lossless/lossy compression of bi-level images....

  6. Deep brain stimulation of pallidal versus subthalamic for patients with Parkinson's disease: a meta-analysis of controlled clinical trials

    Directory of Open Access Journals (Sweden)

    Xu F

    2016-06-01

    Full Text Available Fan Xu,1 Wenbin Ma,2 Yongmin Huang,1 Zhihai Qiu,1 Lei Sun11Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, People’s Republic of China; 2Department of Neurology, Binzhou Medical University Hospital, Binzhou, Shandong, People’s Republic of ChinaBackground: Parkinson's disease (PD is a common neurodegenerative disorder that affects many people every year. Deep brain stimulation (DBS is an effective nonpharmacological method to treat PD motor symptoms. This meta-analysis was conducted to evaluate the efficacy of subthalamic nucleus (STN-DBS versus globus pallidus internus (GPi-DBS in treating advanced PD.Methods: Controlled clinical trials that compared STN-DBS to GPi-DBS for short-term treatment of PD in adults were researched up to November 2015. The primary outcomes were the Unified Parkinson’s Disease Rating Scale Section (UPDRS III score and the levodopa-equivalent dosage (LED after DBS. The secondary outcomes were the UPDRS II score and the Beck Depression Inventory (BDI score.Results: Totally, 13 studies containing 1,148 PD patients were included in this meta-analysis to compare STN-DBS versus GPi-DBS. During the off-medication state, the pooled weighted mean difference (WMD of UPDRS III and II scores were −2.18 (95% CI =−5.11 to 0.74 and −1.96 (95% CI =−3.84 to −0.08, respectively. During the on-medication state, the pooled WMD of UPDRS III and II scores were 0.15 (95% CI =−1.14 to 1.44 and 1.01 (95% CI =0.12 to 1.89, respectively. After DBS, the pooled WMD of LED and BDI were −254.48 (95% CI =−341.66 and 2.29 (95% CI =0.83 to 3.75, respectively.Conclusion: These results indicate that during the off-medication state, the STN-DBS might be superior to GPi-DBS in improving the motor function and activities of daily living for PD patients; but during the on-medication state, the opposite result is observed. Meanwhile, the STN-DBS is superior at reducing

  7. Effects of subthalamic nucleus deep brain stimulation and levodopa on energy production rate and substrate oxidation in Parkinson's disease.

    Science.gov (United States)

    Perlemoine, Caroline; Macia, Frédéric; Tison, François; Coman, Isabelle; Guehl, Dominique; Burbaud, Pierre; Cuny, Emmanuel; Baillet, Laurence; Gin, Henri; Rigalleau, Vincent

    2005-02-01

    Patients with Parkinson's disease (PD) often lose weight, but after subthalamic nucleus deep brain stimulation (STN-DBS), they gain weight. We compared daily energy intake (DEI), resting energy expenditure (REE) and substrate oxidation rates (measured by indirect calorimetry) in nineteen STN-DBS-treated patients (Group S), thirteen others on pharmacologic treatment by levodopa (Group L) and eight control subjects. We also determined the acute effects of STN-DBS and levodopa on REE and substrate oxidation rates. STN-DBS treated patients gained 9.7 (SEM 7.1) kg after surgery, whereas patients on pharmacologic treatment lost 3.8 (SEM 10.0) kg since diagnosis. In STN-DBS-treated patients, REE (-16.5 %; Pweight gain on glycaemia.

  8. Parkinson's disease patients with bilateral subthalamic deep brain stimulation gain weight.

    Science.gov (United States)

    Macia, Frédéric; Perlemoine, Caroline; Coman, Irène; Guehl, Dominique; Burbaud, Pierre; Cuny, Emmanuel; Gin, Henri; Rigalleau, Vincent; Tison, François

    2004-02-01

    Weight, body mass index (BMI) and energy expenditure/energy intake (EE/EI) was studied in 19 Parkinson's disease (PD) patients after subthalamic deep brain stimulation (STN-DBS) versus 14 nonoperated ones. Operated patients had a significant weight gain (WG, + 9.7 +/- 7 kg) and BMI increase (+ 4.7 kg/m2). The fat mass was higher after STN-DBS. Resting EE (REE; offdrug/ON stimulation) was significantly decreased in STN-DBS patients, while their daily energy expenditure (DEI) was not significantly different. A significant correlation was found among WG, BMI increase, and pre-operative levodopa-equivalent daily dose, their reduction after STN-DBS, and the differential REE related to stimulation and the REE in the offdrug/OFF stimulation condition. In conclusion, STN-DBS in PD induces a significant WG associated with a reduction in REE without DEI adjustment.

  9. Early application of deep brain stimulation: clinical and ethical aspects.

    Science.gov (United States)

    Woopen, Christiane; Pauls, K Amande M; Koy, Anne; Moro, Elena; Timmermann, Lars

    2013-11-01

    Deep brain stimulation (DBS) has proven to be a successful therapeutic approach in several patients with movement disorders such as Parkinson's disease and dystonia. Hitherto its application was mainly restricted to advanced disease patients resistant to medication or with severe treatment side effects. However, there is now growing interest in earlier application of DBS, aimed at improving clinical outcomes, quality of life, and avoiding psychosocial consequences of chronic disease-related impairments. We address the clinical and ethical aspects of two "early" uses of DBS, (1) DBS early in the course of the disease, and (2) DBS early in life (i.e. in children). Possible benefits, risks and burdens are discussed and thoroughly considered. Further research is needed to obtain a careful balance between exposing vulnerable patients to potential severe surgical risks and excluding them from a potentially good outcome. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Subthalamic Nucleus Deep Brain Stimulation in Early Stage Parkinson's Disease Is Not Associated with Increased Body Mass Index.

    Science.gov (United States)

    Millan, Sarah H; Hacker, Mallory L; Turchan, Maxim; Molinari, Anna L; Currie, Amanda D; Charles, David

    2017-01-01

    Previous studies suggest that deep brain stimulation of the subthalamic nucleus (STN-DBS) for Parkinson's disease (PD) leads to weight gain. This study analyzes changes in body mass index (BMI) in 29 subjects from a prospective, single-blind trial of DBS in early stage PD (age 50-75, Hoehn & Yahr stage II off medication, treated with antiparkinsonian medications for ≥6 months but 0.05). BMI change over two years was not different between the groups (p = 0.62, ODT = -0.89; DBS+ODT = -0.17). This study suggests that STN-DBS is not associated with weight gain in subjects with early stage PD. This finding will be tested in an upcoming FDA-approved phase III multicenter, randomized, double-blind, placebo-controlled, pivotal clinical trial evaluating DBS in early stage PD (ClinicalTrials.gov identifier NCT00282152).

  11. Engineering the next generation of clinical deep brain stimulation technology.

    Science.gov (United States)

    McIntyre, Cameron C; Chaturvedi, Ashutosh; Shamir, Reuben R; Lempka, Scott F

    2015-01-01

    Deep brain stimulation (DBS) has evolved into a powerful clinical therapy for a range of neurological disorders, but even with impressive clinical growth, DBS technology has been relatively stagnant over its history. However, enhanced collaborations between neural engineers, neuroscientists, physicists, neurologists, and neurosurgeons are beginning to address some of the limitations of current DBS technology. These interactions have helped to develop novel ideas for the next generation of clinical DBS systems. This review attempts collate some of that progress with two goals in mind. First, provide a general description of current clinical DBS practices, geared toward educating biomedical engineers and computer scientists on a field that needs their expertise and attention. Second, describe some of the technological developments that are currently underway in surgical targeting, stimulation parameter selection, stimulation protocols, and stimulation hardware that are being directly evaluated for near term clinical application. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Older Candidates for Subthalamic Deep Brain Stimulation in Parkinson's Disease Have a Higher Incidence of Psychiatric Serious Adverse Events

    Science.gov (United States)

    Cozac, Vitalii V.; Ehrensperger, Michael M.; Gschwandtner, Ute; Hatz, Florian; Meyer, Antonia; Monsch, Andreas U.; Schuepbach, Michael; Taub, Ethan; Fuhr, Peter

    2016-01-01

    Objective: To investigate the incidence of serious adverse events (SAE) of subthalamic deep brain stimulation (STN-DBS) in elderly patients with Parkinson's disease (PD). Methods: We investigated a group of 26 patients with PD who underwent STN-DBS at mean age 63.2 ± 3.3 years. The operated patients from the EARLYSTIM study (mean age 52.9 ± 6.6) were used as a comparison group. Incidences of SAE were compared between these groups. Results: A higher incidence of psychosis and hallucinations was found in these elderly patients compared to the younger patients in the EARLYSTIM study (p < 0.01). Conclusions: The higher incidence of STN-DBS-related psychiatric complications underscores the need for comprehensive psychiatric pre- and postoperative assessment in older DBS candidates. However, these psychiatric SAE were transient, and the benefits of DBS clearly outweighed its adverse effects. PMID:27375478

  13. Star on the horizon: The emergence of the direct broadcast satellite in American mass communications

    Science.gov (United States)

    Thomas, J. H.

    1984-12-01

    The purpose of this thesis is to describe the concept of broadcasting from satellites directly to the viewer equipped with a small, inexpensive receiving antenna, and the evolution of this technology as a means of commercial broadcast. Emphasis is placed on the problems of developing a regulatory framework for DBS by the Federal Communications Commission. The opposition of the existing broadcasters to the unregulated development of direct broadcast satellite (DBS) is explored in light of the possible effect that DBS may have on the economic base, audience, and advertising revenue of existing broadcasters. The information for this study was obtained from government documents, legal journals, books and the popular press. Two basic conclusions are drawn from this study: First, that the existing broadcasters have opposed the marketplace development of DBS, and second, that DBS does not pose as great a threat, at least in the near term, as the broadcasters fear.

  14. The effects of subthalamic deep brain stimulation on metaphor comprehension and language abilities in Parkinson's disease.

    Science.gov (United States)

    Tremblay, Christina; Macoir, Joël; Langlois, Mélanie; Cantin, Léo; Prud'homme, Michel; Monetta, Laura

    2015-02-01

    The effects of subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson's disease (PD) on different language abilities are still controversial and its impact on high-level language abilities such as metaphor comprehension has been overlooked. The aim of this study was to determine the effects of STN electrical stimulation on metaphor comprehension and language abilities such as lexical and semantic capacities. Eight PD individuals with bilateral STN-DBS were first evaluated OFF-DBS and, at least seven weeks later, ON-DBS. Performance on metaphor comprehension, lexical decision, word association and verbal fluency tasks were compared ON and OFF-DBS in addition to motor symptoms evaluation. STN stimulation had a significant beneficial effect on motor symptoms in PD. However, this stimulation did not have any effect on metaphor comprehension or any other cognitive ability evaluated in this study. These outcomes suggest that STN stimulation may have dissociable effects on motor and language functions.

  15. Mixed effects of deep brain stimulation on depressive symptomatology in Parkinson’s disease: a review of randomized clinical trials

    Directory of Open Access Journals (Sweden)

    N. Simay eGokbayrak

    2014-08-01

    Full Text Available Although ~50% of patients with Parkinson’s disease (PD experience depression, treatment for this important and debilitating comorbitidy is relatively understudied. Deep brain stimulation (DBS has been increasingly utilized for the management of tremors in progressive PD. Several preliminary studies have shown the potential benefit of DBS for non-motor PD symptoms such as depression. Here, we critically evaluate seven recent randomized controlled trials (RCT of the effectiveness of DBS in reducing depressive symptomatology among individuals with PD. Findings are mixed for the effectiveness of DBS as a treatment for depression in PD. Our review suggests that is due, in large part, to the anatomical and methodological variation across the DBS studies. We provide a comprehensive discussion of these variations and highlight the need to conduct larger, more controlled studies aimed specifically at evaluating the treatment of depression in PD patients.

  16. The influence of the dried blood spot drying time on the recoveries of six immunosuppressants

    Directory of Open Access Journals (Sweden)

    Remco A. Koster

    2015-10-01

    Full Text Available Investigation of the drying time of dried blood spots (DBS is currently not included in DBS validations. The influence of the DBS drying time on the recovery of tacrolimus, ascomycin, sirolimus, everolimus, cyclosporin A and temsirolimus was evaluated by measuring DBS with a fixed blood volume at a hematocrit range between 0.1 and 0.6 L/L at 3, 24 and 48 hours of drying time. Results showed that the recovery of sirolimus, everolimus, temsirolimus and cyclosporin A was influenced by the DBS drying time, while the recovery of tacrolimus and ascomycin was not. A drying time of at least 24 hours is advised in order to stabilize hematocrit and concentration related recovery effects of sirolimus, everolimus, temsirolimus and cyclosporin A.

  17. A Review of Social and Relational Aspects of Deep Brain Stimulation in Parkinson's Disease Informed by Healthcare Provider Experiences

    Directory of Open Access Journals (Sweden)

    Emily Bell

    2011-01-01

    Full Text Available Background. Although the clinical effectiveness of deep brain stimulation (DBS in Parkinson's disease is established, there has been less examination of its social aspects. Methods and Results. Building on qualitative comments provided by healthcare providers, we present four different social and relational issues (need for social support, changes in relationships (with self and partner and challenges with regards to occupation and the social system. We review the literature from multiple disciplines on each issue. We comment on their ethical implications and conclude by establishing the future prospects for research with the possible expansion of DBS for psychiatric indications. Conclusions. Our review demonstrates that there are varied social issues involved in DBS. These issues may have significant impacts on the perceived outcome of DBS by patients. Moreover, the fact that the social impact of DBS is still not well understood in emerging psychiatric indications presents an important area for future examination.

  18. Surgery insight: Deep brain stimulation for movement disorders.

    Science.gov (United States)

    Anderson, William S; Lenz, Frederick A

    2006-06-01

    Over the past two decades, deep brain stimulation (DBS) has supplanted lesioning techniques for the treatment of movement disorders, and has been shown to be safe and efficacious. The primary therapeutic indications for DBS are essential tremor, dystonia and Parkinson's disease. In the case of Parkinson's disease, DBS is effective for treating the primary symptoms--tremor, bradykinesia and rigidity--as well as the motor complications of drug treatment. Progress has been made in understanding the effects of stimulation at the neuronal level, and this knowledge should eventually improve the effectiveness of this therapy. Preliminary studies also indicate that DBS might be used to treat Tourette's syndrome, obsessive-compulsive disorder, depression and epilepsy. As we will discuss in this review, the success of DBS depends on an appropriate rationale for the procedure, and on collaborations between neurologists and neurosurgeons in defining outcomes.

  19. Synergism between cerium nitrate and sodium dodecylbenzenesulfonate on corrosion of AA5052 aluminium alloy in 3 wt.% NaCl solution

    Science.gov (United States)

    Liu, Jie; Wang, Dapeng; Gao, Lixin; Zhang, Daquan

    2016-12-01

    The synergistic inhibition effect of rare earth cerium nitrate and sodium dodecylbenzenesulfonate (DBS) on corrosion of AA5052 aluminium alloy in 3 wt.% NaCl solution was investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curve, scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR). The results show that the single cerium nitrate or DBS has a limited inhibition effect against corrosion of AA5052 alloy. The combination cerium ions with DBS produced strong synergistic effect on corrosion inhibition for AA5052 alloy and rendered a negaitve shift of the corrosion potential. The formation of the complex of Al(DBS)3 and Ce(DBS)3 stabilized the passive film of Al2O3 and CeO2, retarding both the cathodic and anodic processes of AA5052 alloy corrosion reaction significantly.

  20. Magnetic resonance imaging safety of deep brain stimulator devices.

    Science.gov (United States)

    Oluigbo, Chima O; Rezai, Ali R

    2013-01-01

    Magnetic resonance imaging (MRI) has become the standard of care for the evaluation of different neurological disorders of the brain and spinal cord due to its multiplanar capabilities and excellent soft tissue resolution. With the large and increasing population of patients with implanted deep brain stimulation (DBS) devices, a significant proportion of these patients with chronic neurological diseases require evaluation of their primary neurological disease processes by MRI. The presence of an implanted DBS device in a magnetic resonance environment presents potential hazards. These include the potential for induction of electrical currents or heating in DBS devices, which can result in neurological tissue injury, magnetic field-induced device migration, or disruption of the operational aspects of the devices. In this chapter, we review the basic physics of potential interactions of the MRI environment with implanted DBS devices, summarize results from phantom studies and clinical series, and discuss present recommendations for safe MRI in patients with implanted DBS devices.

  1. Dicty_cDB: Contig-U12691-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 1 AE009441_2344( AE009441 |pid:none) Pyrobaculum aerophilum str. IM2... 35 4.1 FJ611395_1( FJ611395 |pid:none) Plethodon... fourchensis voucher DBS ... 34 5.4 FJ611471_1( FJ611471 |pid:none) Plethodon fourchensis vouche...r DBS ... 34 5.4 FJ611385_1( FJ611385 |pid:none) Plethodon fourchensis voucher DB...S ... 34 5.4 FJ611465_1( FJ611465 |pid:none) Plethodon fourchensis voucher DBS ... 34 5.4 FJ611400_1( FJ611400 |pid:none) Plethodon... fourchensis voucher DBS ... 34 5.4 FJ611415_1( FJ611415 |pid:none) Plethodon fourche

  2. The change in cerebral glucose metabolism after electroacupuncture: a possible marker to predict the therapeutic effect of deep brain stimulation for refractory anorexia nervosa.

    Science.gov (United States)

    Liu, Tao-Tao; Hong, Qing-Xiong; Xiang, Hong-Bing

    2015-01-01

    Some reports have demonstrated that deep brain stimulation (DBS) is a promising treatment for patients who suffer from intractable anorexia nervosa. However, the nature of DBS may not be viewed as a standard clinical treatment option for anorexia nervosa because of the unpredictable outcome before DBS. Just like DBS in the brain, electroacupuncture at acupoints is also efficient in treating refractory anorexia nervosa. Some neuroimaging studies using functional magnetic resonance imaging, single-photon emission computed tomography (SPECT), and positron emission tomography (PET) had revealed that both DBS and electroacupuncture at acupoints with electrical stimulation are related to the changes in cerebral glucose metabolism. Therefore, we hypothesize that the changes in cerebral glucose metabolism after electroacupuncture might be useful to predict the therapeutic effect of deep brain stimulation for refractory anorexia nervosa.

  3. Anaesthetic management of shoulder arthroscopic repair in Parkinson′s disease with deep brain stimulator

    Directory of Open Access Journals (Sweden)

    Ranju Gandhi

    2014-01-01

    Full Text Available We describe the anaesthetic management of arthroscopic repair for complete rotator cuff tear of shoulder in a 59-year-old female with Parkinson′s disease (PD with deep brain stimulator (DBS using a combination of general anaesthesia with interscalene approach to brachial plexus block. The DBS consists of implanted electrodes in the brain connected to the implantable pulse generator (IPG normally placed in the anterior chest wall subcutaneously. It can be programmed externally from a hand-held device placed directly over the battery stimulator unit. In our patient, IPG with its leads was located in close vicinity of the operative site with potential for DBS malfunction. Implications of DBS in a patient with PD for shoulder arthroscopy for anaesthesiologist are discussed along with a brief review of DBS.

  4. CYP1A2 phenotyping in dried blood spots and microvolumes of whole blood and plasma.

    Science.gov (United States)

    De Kesel, Pieter M M; Lambert, Willy E; Stove, Christophe P

    2014-01-01

    Phenotyping, using caffeine as probe substrate, is a proper method to assess CYP1A2 activity. We evaluated the utility of dried blood spots (DBS) for CYP1A2 phenotyping. LC-MS/MS methods were developed and validated for quantitation of caffeine and its metabolite paraxanthine in DBS, whole blood and plasma. All parameters met the pre-established criteria. While recovery, matrix effects and precision were unaffected by hematocrit (Hct), there was a Hct effect on accuracy, although for the evaluated Hct interval (0.36-0.50) it remained within acceptable limits. The phenotyping methods were successfully applied in healthy volunteers. Excellent method performance and highly comparable phenotyping indices in DBS, whole blood and plasma, combined with the benefits of DBS sampling, illustrate the suitability of DBS-based CYP1A2 phenotyping.

  5. Meaningful Share Generation for Increased Number of Secrets in Visual Secret-Sharing Scheme

    Directory of Open Access Journals (Sweden)

    Mustafa Ulutas

    2010-01-01

    Full Text Available This paper presents a new scheme for hiding two halftone secret images into two meaningful shares created from halftone cover images. Meaningful shares are more desirable than noise-like (meaningless shares in Visual Secret Sharing because they look natural and do not attract eavesdroppers' attention. Previous works in the field focus on either increasing number of secrets or creating meaningful shares for one secret image. The method outlined in this paper both increases the number of secrets and creates meaningful shares at the same time. While the contrast ratio of shares is equal to that of Extended Visual Cryptography, two secrets are encoded into two shares as opposed to one secret in the Extended Visual Cryptography. Any two natural-looking images can be used as cover unlike the Halftone Visual Cryptography method where one cover should be the negative of the other cover image and can only encode one secret. Effectiveness of the proposed method is verified by an experiment.

  6. Therapeutic subthalamic nucleus deep brain stimulation reverses cortico-thalamic coupling during voluntary movements in Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Josh Kahan

    Full Text Available Deep brain stimulation of the subthalamic nucleus (STN DBS has become an accepted treatment for patients experiencing the motor complications of Parkinson's disease (PD. While its successes are becoming increasingly apparent, the mechanisms underlying its action remain unclear. Multiple studies using radiotracer-based imaging have investigated DBS-induced regional changes in neural activity. However, little is known about the effect of DBS on connectivity within neural networks; in other words, whether DBS impacts upon functional integration of specialized regions of cortex. In this work, we report the first findings of fMRI in 10 subjects with PD and fully implanted DBS hardware receiving efficacious stimulation. Despite the technical demands associated with the safe acquisition of fMRI data from patients with implanted hardware, robust activation changes were identified in the insula cortex and thalamus in response to therapeutic STN DBS. We then quantified the neuromodulatory effects of DBS and compared sixteen dynamic causal models of effective connectivity between the two identified nodes. Using Bayesian model comparison, we found unequivocal evidence for the modulation of extrinsic (between region, i.e. cortico-thalamic and thalamo-cortical connections. Using Bayesian model parameter averaging we found that during voluntary movements, DBS reversed the effective connectivity between regions of the cortex and thalamus. This casts the therapeutic effects of DBS in a fundamentally new light, emphasising a role in changing distributed cortico-subcortical interactions. We conclude that STN DBS does impact upon the effective connectivity between the cortex and thalamus by changing their sensitivities to extrinsic afferents. Furthermore, we confirm that fMRI is both feasible and is tolerated well by these patients provided strict safety measures are adhered to.

  7. Hepatitis B viral load in dried blood spots: a validation study in Zambia

    Science.gov (United States)

    Vinikoor, Michael J.; Zürcher, Samuel; Musukuma, Kalo; Kachuwaire, Obert; Rauch, Andri; Chi, Benjamin H.; Gorgievski, Meri; Zwahlen, Marcel; Wandeler, Gilles

    2016-01-01

    Background Access to hepatitis B viral load (VL) testing is poor in sub-Saharan Africa (SSA) due to economic and logistical reasons. Objectives To demonstrate the feasibility of testing dried blood spots (DBS) for hepatitis B virus (HBV) VL in a laboratory in Lusaka, Zambia, and to compare HBV VLs between DBS and plasma samples. Study design Paired plasma and DBS samples from HIV-HBV co-infected Zambian adults were analyzed for HBV VL using the COBAS AmpliPrep/COBAS TaqMan HBV test (Version 2.0) and for genotype by direct sequencing. We used Bland-Altman analysis to compare VLs between sample types and by HBV genotype. Logistic regression analysis was conducted to assess the probability of an undetectable DBS result by plasma VL. Results Among 68 participants, median age was 34 years, 61.8% were men, and median plasma HBV VL was 3.98 log IU/ml (interquartile range, 2.04–5.95). Among sequenced viruses, 28 were genotype A1 and 27 were genotype E. Bland-Altman plots suggested strong agreement between DBS and plasma VLs. DBS VLs were on average 1.59 log IU/ml lower compared to plasma with 95% limits of agreement of −2.40 to −0.83 log IU/ml. At a plasma VL ≥2,000 IU/ml, the probability of an undetectable DBS result was 1.8% (95% CI: 0.5–6.6). At plasma VL ≥20,000 IU/ml this probability reduced to 0.2% (95% CI: 0.03–1.7). Conclusions In a Zambian laboratory, we observed strong agreement between DBS and plasma VLs and high sensitivity in DBS at plasma VL ≥2,000 IU/ml. As HBV treatment expands, DBS could increase access to HBV VL testing in SSA settings. PMID:26356987

  8. Hypothalamic deep brain stimulation reduces weight gain in an obesity-animal model.

    Science.gov (United States)

    Melega, William P; Lacan, Goran; Gorgulho, Alessandra A; Behnke, Eric J; De Salles, Antonio A F

    2012-01-01

    Prior studies of appetite regulatory networks, primarily in rodents, have established that targeted electrical stimulation of ventromedial hypothalamus (VMH) can alter food intake patterns and metabolic homeostasis. Consideration of this method for weight modulation in humans with severe overeating disorders and morbid obesity can be further advanced by modeling procedures and assessing endpoints that can provide preclinical data on efficacy and safety. In this study we adapted human deep brain stimulation (DBS) stereotactic methods and instrumentation to demonstrate in a large animal model the modulation of weight gain with VMH-DBS. Female Göttingen minipigs were used because of their dietary habits, physiologic characteristics, and brain structures that resemble those of primates. Further, these animals become obese on extra-feeding regimens. DBS electrodes were first bilaterally implanted into the VMH of the animals (n = 8) which were then maintained on a restricted food regimen for 1 mo following the surgery. The daily amount of food was then doubled for the next 2 mo in all animals to produce obesity associated with extra calorie intake, with half of the animals (n = 4) concurrently receiving continuous low frequency (50 Hz) VMH-DBS. Adverse motoric or behavioral effects were not observed subsequent to the surgical procedure or during the DBS period. Throughout this 2 mo DBS period, all animals consumed the doubled amount of daily food. However, the animals that had received VMH-DBS showed a cumulative weight gain (6.1±0.4 kg; mean ± SEM) that was lower than the nonstimulated VMH-DBS animals (9.4±1.3 kg; p<0.05), suggestive of a DBS-associated increase in metabolic rate. These results in a porcine obesity model demonstrate the efficacy and behavioral safety of a low frequency VMH-DBS application as a potential clinical strategy for modulation of body weight.

  9. Hypothalamic deep brain stimulation reduces weight gain in an obesity-animal model.

    Directory of Open Access Journals (Sweden)

    William P Melega

    Full Text Available Prior studies of appetite regulatory networks, primarily in rodents, have established that targeted electrical stimulation of ventromedial hypothalamus (VMH can alter food intake patterns and metabolic homeostasis. Consideration of this method for weight modulation in humans with severe overeating disorders and morbid obesity can be further advanced by modeling procedures and assessing endpoints that can provide preclinical data on efficacy and safety. In this study we adapted human deep brain stimulation (DBS stereotactic methods and instrumentation to demonstrate in a large animal model the modulation of weight gain with VMH-DBS. Female Göttingen minipigs were used because of their dietary habits, physiologic characteristics, and brain structures that resemble those of primates. Further, these animals become obese on extra-feeding regimens. DBS electrodes were first bilaterally implanted into the VMH of the animals (n = 8 which were then maintained on a restricted food regimen for 1 mo following the surgery. The daily amount of food was then doubled for the next 2 mo in all animals to produce obesity associated with extra calorie intake, with half of the animals (n = 4 concurrently receiving continuous low frequency (50 Hz VMH-DBS. Adverse motoric or behavioral effects were not observed subsequent to the surgical procedure or during the DBS period. Throughout this 2 mo DBS period, all animals consumed the doubled amount of daily food. However, the animals that had received VMH-DBS showed a cumulative weight gain (6.1±0.4 kg; mean ± SEM that was lower than the nonstimulated VMH-DBS animals (9.4±1.3 kg; p<0.05, suggestive of a DBS-associated increase in metabolic rate. These results in a porcine obesity model demonstrate the efficacy and behavioral safety of a low frequency VMH-DBS application as a potential clinical strategy for modulation of body weight.

  10. Dried blood spot sampling for hepatitis B virus serology and molecular testing.

    Directory of Open Access Journals (Sweden)

    Sofiane Mohamed

    Full Text Available BACKGROUND AIMS: Dried blood spots (DBS on filter paper have been successfully used to diagnose and monitor several infectious diseases. The aim was to investigate the performance of DBS in hepatitis B virus (HBV diagnosis using commercial tests in comparison to standard methods. METHODS: Paired DBS and plasma samples were collected from 200 patients: 100 patients with HBsAg negative status and 100 patients with HBsAg positive status. In the latter patient, HBeAg reactivity was tested. Ten samples of anti-HBs were collected from people vaccinated against HBV. We also studied 50 patients with positive HBV DNA viral load in plasma and 10 HBV DNA negative patients. HBV genotypes and gene polymerase mutations were determined in 10 randomly selected HBV-infected patients. The DBS sample consisted of 50 µL of whole blood, i.e. a 12-mm paper card. RESULTS: The sensitivity thresholds of HBsAg and anti-HBs antibody were 0.30 ± 0.08 IU/mL and 18.11 ± 6.05 IU/mL, respectively, for DBS with 98% sensitivity and 100% specificity. Sensitivity was 98% and specificity 100% for the detection of HBV DNA on a blotter, considering an HBV DNA threshold of 914.1 ± 157.8 IU/ml. Ten patients had an HBeAg positive status in plasma, all were detected positive using DBS. HBV genotyping and mutation detection were successfully performed on DBS, with full concordance between the 10 paired DBS and plasma samples. CONCLUSION: This study shows DBS is a reliable alternative to plasma specimens for quantifying and detecting HBsAg, anti-HBs, HBeAg and genotyping. DBS may increase the opportunities for HBV testing and treatment follow-up in hard-to-reach individuals.

  11. Increased dopamine receptor expression and anti-depressant response following deep brain stimulation of the medial forebrain bundle.

    Science.gov (United States)

    Dandekar, Manoj P; Luse, Dustin; Hoffmann, Carson; Cotton, Patrick; Peery, Travis; Ruiz, Christian; Hussey, Caroline; Giridharan, Vijayasree V; Soares, Jair C; Quevedo, Joao; Fenoy, Albert J

    2017-08-01

    Among several potential neuroanatomical targets pursued for deep brain stimulation (DBS) for treating those with treatment-resistant depression (TRD), the superolateral-branch of the medial forebrain bundle (MFB) is emerging as a privileged location. We investigated the antidepressant-like phenotypic and chemical changes associated with reward-processing dopaminergic systems in rat brains after MFB-DBS. Male Wistar rats were divided into three groups: sham-operated, DBS-Off, and DBS-On. For DBS, a concentric bipolar electrode was stereotactically implanted into the right MFB. Exploratory activity and depression-like behavior were evaluated using the open-field and forced-swimming test (FST), respectively. MFB-DBS effects on the dopaminergic system were evaluated using immunoblotting for tyrosine hydroxylase (TH), dopamine transporter (DAT), and dopamine receptors (D1-D5), and high-performance liquid chromatography for quantifying dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) in brain homogenates of prefrontal cortex (PFC), hippocampus, amygdala, and nucleus accumbens (NAc). Animals receiving MFB-DBS showed a significant increase in swimming time without alterations in locomotor activity, relative to the DBS-Off (p<0.039) and sham-operated groups (p<0.014), indicating an antidepressant-like response. MFB-DBS led to a striking increase in protein levels of dopamine D2 receptors and DAT in the PFC and hippocampus, respectively. However, we did not observe appreciable differences in the expression of other dopamine receptors, TH, or in the concentrations of dopamine, DOPAC, and HVA in PFC, hippocampus, amygdala, and NAc. This study was not performed on an animal model of TRD. MFB-DBS rescues the depression-like phenotypes and selectively activates expression of dopamine receptors in brain regions distant from the target area of stimulation. Copyright © 2017. Published by Elsevier B.V.

  12. Deep brain stimulation exacerbates hypokinetic dysarthria in a rat model of Parkinson's disease.

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    King, Nathaniel O; Anderson, Collin J; Dorval, Alan D

    2016-02-01

    Motor symptoms of Parkinson's disease (PD) follow the degeneration of dopaminergic neurons in the substantia nigra pars compacta. Deep brain stimulation (DBS) treats some parkinsonian symptoms, such as tremor, rigidity, and bradykinesia, but may worsen certain medial motor symptoms, including hypokinetic dysarthria. The mechanisms by which DBS exacerbates dysarthria while improving other symptoms are unclear and difficult to study in human patients. This study proposes an animal model of DBS-exacerbated dysarthria. We use the unilateral, 6-hydroxydopamine (6-OHDA) rat model of PD to test the hypothesis that DBS exacerbates quantifiable aspects of vocalization. Mating calls were recorded from sexually experienced male rats under healthy and parkinsonian conditions and during DBS of the subthalamic nucleus. Relative to healthy rats, parkinsonian animals made fewer calls with shorter and less complex vocalizations. In the parkinsonian rats, putatively therapeutic DBS further reduced call frequency, duration, and complexity. The individual utterances of parkinsonian rats spanned a greater bandwidth than those of healthy rats, potentially reducing the effectiveness of the vocal signal. This utterance bandwidth was further increased by DBS. We propose that the parkinsonism-associated changes in call frequency, duration, complexity, and dynamic range combine to constitute a rat analog of parkinsonian dysarthria. Because DBS exacerbates the parkinsonism-associated changes in each of these metrics, the subthalamic stimulated 6-OHDA rat is a good model of DBS-induced hypokinetic dysarthria in PD. This model will help researchers examine how DBS alleviates many motor symptoms of PD while exacerbating parkinsonian speech deficits that can greatly diminish patient quality of life.

  13. Performance and Storage Integrity of Dried Blood Spots for PCB, BFR and Pesticide Measurements

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    Batterman, Stuart; Chernyak, Sergei

    2014-01-01

    Dried blood spots (DBS) can provide accurate and valuable estimates of exposure to environmental toxicants, and the use of information derived from archived newborn DBS information has enormous potential to open up new research on the impacts of early chemical exposure on disease. Broad application of DBS for the purpose of quantitative exposure estimation requires robust and validated methods. This study investigates the suitability of DBS analyses for population studies of exposure to three chemical groups: polychlorinated biphenyls (PCBs), brominated flame retardants (BFRs), and chlorinated pesticides. It examines background (matrix) contamination, recovery and extraction variability, sensitivity, and storage stability. DBS samples prepared using 50 μL of adult blood were analyzed by GC/MS, and method performance was confirmed by using certified materials and paired DBS-blood samples from six volunteers. Several of the target compounds and their degradation products have not been previously measured in DBS. All target compounds were detected in DBS samples collected from the volunteers. Sample DBS cards showed background contamination of several compounds. When stored at room temperature, target compounds, excluding PBDEs, were stable for up to one month. When refrigerated or frozen, stability was acceptable for all compounds up to one year, and multiyear storage appears acceptable at colder (e.g., −80 °C) temperatures. Multicompartment models may be used to estimate or correct for storage losses. Considering concentrations of contaminants for adults and children reported in the literature, and experimental values of detection limits and background contamination, DBS samples are suitable for quantifying exposures to many PCBs, BFRs and persistent pesticides. PMID:25058892

  14. Subthalamic Nucleus Deep Brain Stimulation May Reduce Medication Costs in Early Stage Parkinson’s Disease

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    Hacker, Mallory L.; Currie, Amanda D.; Molinari, Anna L.; Turchan, Maxim; Millan, Sarah M.; Heusinkveld, Lauren E.; Roach, Jonathon; Konrad, Peter E.; Davis, Thomas L.; Neimat, Joseph S.; Phibbs, Fenna T.; Hedera, Peter; Byrne, Daniel W.; Charles, David

    2016-01-01

    Background: Subthalamic nucleus deep brain stimulation (STN-DBS) is well-known to reduce medication burden in advanced stage Parkinson’s disease (PD). Preliminary data from a prospective, single blind, controlled pilot trial demonstrated that early stage PD subjects treated with STN-DBS also required less medication than those treated with optimal drug therapy (ODT). Objective: The purpose of this study was to analyze medication cost and utilization from the pilot trial of DBS in early stage PD and to project 10 year medication costs. Methods: Medication data collected at each visit were used to calculate medication costs. Medications were converted to levodopa equivalent daily dose, categorized by medication class, and compared. Medication costs were projected to advanced stage PD, the time when a typical patient may be offered DBS. Results: Medication costs increased 72% in the ODT group and decreased 16% in the DBS+ODT group from baseline to 24 months. This cost difference translates into a cumulative savings for the DBS+ODT group of $7,150 over the study period. Projected medication cost savings over 10 years reach $64,590. Additionally, DBS+ODT subjects were 80% less likely to require polypharmacy compared with ODT subjects at 24 months (p <  0.05; OR = 0.2; 95% CI: 0.04–0.97). Conclusions: STN-DBS in early PD reduced medication cost over the two-year study period. DBS may offer substantial long-term reduction in medication cost by maintaining a simplified, low dose medication regimen. Further study is needed to confirm these findings, and the FDA has approved a pivotal, multicenter clinical trial evaluating STN-DBS in early PD. PMID:26967937

  15. Evaluation of a single round polymerase chain reaction assay using dried blood spots for diagnosis of HIV-1 infection in infants in an African setting

    Directory of Open Access Journals (Sweden)

    Ng'ayo Musa

    2011-02-01

    Full Text Available Abstract Background The aim of this study was to develop an economical 'in-house' single round polymerase chain reaction (PCR assay using filter paper-dried blood spots (FP-DBS for early infant HIV-1 diagnosis and to evaluate its performance in an African setting. Methods An 'in-house' single round PCR assay that targets conserved regions in the HIV-1 polymerase (pol gene was validated for use with FP-DBS; first we validated this assay using FP-DBS spiked with cell standards of known HIV-1 copy numbers. Next, we validated the assay by testing the archived FP-DBS (N = 115 from infants of known HIV-1 infection status. Subsequently this 'in-house' HIV-1 pol PCR FP-DBS assay was then established in Nairobi, Kenya for further evaluation on freshly collected FP-DBS (N = 186 from infants, and compared with findings from a reference laboratory using the Roche Amplicor® HIV-1 DNA Test, version 1.5 assay. Results The HIV-1 pol PCR FP-DBS assay could detect one HIV-1 proviral copy in 38.7% of tests, 2 copies in 46.9% of tests, 5 copies in 72.5% of tests and 10 copies in 98.1% of tests performed with spiked samples. Using the archived FP-DBS samples from infants of known infection status, this assay was 92.8% sensitive and 98.3% specific for HIV-1 infant diagnosis. Using 186 FP-DBS collected from infants recently defined as HIV-1 positive using the commercially available Roche Amplicor v1.5 assay, 178 FP-DBS tested positive by this 'in-house' single-round HIV-1 pol PCR FP-DBS PCR assay. Upon subsequent retesting, the 8 infant FP-DBS samples that were discordant were confirmed as HIV-1 negative by both assays using a second blood sample. Conclusions HIV-1 was detected with high sensitivity and specificity using both archived and more recently collected samples. This suggests that this 'in-house' HIV-1 pol FP-DBS PCR assay can provide an alternative cost-effective, reliable and rapid method for early detection of HIV-1 infection in infants.

  16. Validation of Cobas AmpliPrep/Cobas TaqMan HIV-1 Test on dried blood spots

    Directory of Open Access Journals (Sweden)

    N Ruiz

    2012-11-01

    Full Text Available The plasma specimen is the gold standard for viral load monitoring, the key method to assess the effect of antiviral chemotherapy and to monitor progression of the disease toward AIDS. Nevertheless, several works endorse the use of dried blood spots (DBS on filter paper for the reliable quantification of the levels needed to take therapeutic decisions, detect of treatment failure and monitor the occurrence of drug resistance. The purpose of this study was to validate the use of Cobas AmpliPrep/Cobas TaqMan HIV-1 test version 2.0, with DBS. To evaluate the performance of the above mentioned kit, three stages were involved: 1- Standardization of DBS working conditions, 2- Stability studies at three temperature conditions and 3- Performance evaluation of the kit using this alternative specimen. Additionally, the viral load was quantified in parallel (plasma and DBS to 43 genetically characterized samples, with different levels of viral load. The Pearson correlation coefficient was calculated and the prediction of the value of RNA in plasma starting from the obtained value in DBS was made. Linear regression analysis was performed and coefficients of variation in precision assays were calculated. The best conditions pickups to the work with DBS were: 100 µL of blood (2 spots/50 µl, dried time between 16 and 18 hours at room temperature and, elution of the blood, 2 hours, between 2 and 8°C; in TRIS-EDTA buffer. The samples on DBS proved to be stable during the study periods. A strong correlation was attained between the measurements of viral load in plasma and DBS samples (r=0.96. The detection rate was 90.7 and the coefficient of variation between the values obtained in plasma-DBS sample pairs averaged 3.42%. The CAP/CTM HIV-1 test provided a linear response in DBS, from 330 copies/mL to 420 000 copies/mL. Overall, coefficients of variation in precision tests were below 10%. Cobas AmpliPrep/Cobas TaqMan HIV-1 test version 2.0 had a good

  17. Information virtual indicator with combination of diffractive optical elements

    Science.gov (United States)

    Grad, Y. A.; Drozdova, E. A.; Nayden, L. A.; Nikolaev, V. V.; Odinokov, S. B.; Solomashenko, A. B.

    2016-08-01

    A combination of diffractive optical elements for monochrome information virtual indicators is described. To reduce the spectral "blurring" of image in monochrome indicators with OLED-display or LCD-display with LED backlight the possibility of using the volume reflection hologram as a spectral filter is investigated. The theoretical and experimental results show that the volume reflection hologram can be used as part of a monochrome virtual indicator containing OLED-, LCOS- or LCD-display with LED-backlight and relief-phase gratings for output of radiation from substrate to reduce the spectral "blurring" of image.

  18. Effects of deep brain stimulation on vocal fold immobility in Parkinson's disease

    Science.gov (United States)

    Arocho-Quinones, Elsa V.; Hammer, Michael J.; Bock, Jonathan M.; Pahapill, Peter A.

    2017-01-01

    Background: Vocal fold (VF) immobility is a rare, potentially fatal complication of advanced Parkinson's disease (PD). Previous reports suggest that subthalamic nucleus deep brain stimulation (STN-DBS) may influence laryngeal function, yet the role of STN-DBS on VF immobility remains unexplored. Case Description: We report a case of a patient with advanced PD and bilateral VF immobility ultimately requiring a tracheostomy. To assess the effects of STN-DBS on vocal cord function and to correlate these effects with peripheral motor symptoms at different stimulation settings, the patient was evaluated before and after initiation of bilateral STN-DBS. Measures included direct observation of VF mobility via transnasal laryngoscopy, levodopa equivalent dose of anti-PD medication, and motor scores. High frequency (150 Hz) STN-DBS resulted in improved motor scores, reduced medication requirement, and modestly improved right VF abduction although insufficient for safe decannulation. Low frequency (60 Hz) stimulation resulted in lower motor scores, but without worsening VF abduction. Conclusions: STN-DBS may play an important role in the neuromodulation of PD-induced laryngeal dysfunction, including VF mobility. Characterization of these axial symptoms is important when programming and evaluating responsiveness to DBS. PMID:28303202

  19. Self-Reported Executive Functioning in Everyday Life in Parkinson's Disease after Three Months of Subthalamic Deep Brain Stimulation.

    Science.gov (United States)

    Pham, Uyen Ha Gia; Andersson, Stein; Toft, Mathias; Pripp, Are Hugo; Konglund, Ane Eidahl; Dietrichs, Espen; Malt, Ulrik Fredrik; Skogseid, Inger Marie; Haraldsen, Ira Ronit Hebolt; Solbakk, Anne-Kristin

    2015-01-01

    Objective. Studies on the effect of subthalamic deep brain stimulation (STN-DBS) on executive functioning in Parkinson's disease (PD) are still controversial. In this study we compared self-reported daily executive functioning in PD patients before and after three months of STN-DBS. We also examined whether executive functioning in everyday life was associated with motor symptoms, apathy, and psychiatric symptoms. Method. 40 PD patients were examined with the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A), the Symptom Checklist 90-Revised (SCL-90-R), and the Apathy Evaluation Scale (AES-S). Results. PD patients reported significant improvement in daily life executive functioning after 3 months of STN-DBS. Anxiety scores significantly declined, while other psychiatric symptoms remained unchanged. The improvement of self-reported executive functioning did not correlate with motor improvement after STN-DBS. Apathy scores remained unchanged after surgery. Only preoperative depressed mood had predictive value to the improvement of executive function and appears to prevent potentially favorable outcomes from STN-DBS on some aspects of executive function. Conclusion. PD patients being screened for STN-DBS surgery should be evaluated with regard to self-reported executive functioning. Depressive symptoms in presurgical PD patients should be treated. Complementary information about daily life executive functioning in PD patients might enhance further treatment planning of STN-DBS.

  20. Sensitization effects of supramolecular assemblies on the luminescence of terbium-ion prulifloxacin complexes

    Energy Technology Data Exchange (ETDEWEB)

    Wang Hong; Yi Chongyue; Li Xue; Fang Fang [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Yang Yajiang, E-mail: yjyang@mail.hust.edu.c [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2011-04-15

    Luminescence enhancement of terbium-ion prulifloxacin complexes (Tb(III)-PUFX) in supramolecular hydrogels formed by assembly of 1,3:2,4-di-O-benzylidene-D-sorbitol (DBS) was investigated by steady-state fluorescence, varying temperature fluorescence and time-resolved fluorescence. The luminescence images show that Tb(III)-PUFX were dispersed in the DBS gels. The luminescence intensity of Tb(III)-PUFX in the DBS gels was significantly increased in comparison with that in corresponding aqueous solutions. The varying temperature fluorescent spectra show that the luminescence intensity of Tb(III)-PUFX decreased with an increase in the temperature. This implies that the luminescence enhancement of Tb(III)-PUFX is related to the dissociation and the formation of the DBS assemblies. Time-resolved fluorescence measurements show slower rotational motion in DBS gels in comparison with that in the corresponding aqueous solutions. This may be ascribed to a unique microstructure of three-dimensional network formed by DBC aggregates, resulting in deactivation of the nonradiative relaxation. The images of field emission scanning electron microscopy and polarized optical microscopy indicate that the morphology of the DBS assemblies was not influenced upon addition of Tb(III)-PUFX to the DBS gels.