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BACKGROUND: Many physicians do not consider the diagnosis of bile acid malabsorption in patients with chronic diarrhea, or do not have access to testing. We examined yield of 23-seleno-25-homo-tauro-cholic acid (SeHCAT) scanning in chronic diarrhea patients, and attempted to identify predictors of a positive test. METHODS: Consecutive patients with chronic diarrhea undergoing SeHCAT scan over a 7-year period were identified retrospectively. Bile acid malabsorption was defined as present at a retention of <15%. Medical records were reviewed to obtain information regarding proposed risk factors. Gastrointestinal symptoms were recorded, and patients were classified as having diarrhea-predominant irritable bowel syndrome (IBS-D) if they reported abdominal pain or discomfort. Independent risk factors were assessed using multivariate logistic regression, and odds ratios (ORs) with 99% confidence intervals (CIs) were calculated. KEY RESULTS: Of 373 patients, 190 (50.9%) had bile acid malabsorption. Previous cholecystectomy (OR 2.51; 99% CI 1.10-5.77), terminal ileal resection or right hemicolectomy for Crohn's disease (OR 12.4; 99% CI 2.42-63.8), and terminal ileal resection or right hemicolectomy for other reasons (OR 7.94; 99% CI 1.02-61.6) were associated with its presence. Seventy-seven patients had IBS-D, and 21 (27.3%) tested positive. There were 168 patients with no risk factors for a positive SeHCAT scan, other than chronic diarrhea, and 63 (37.5%) had bile acid malabsorption. CONCLUSIONS & INFERENCES: Bile acid malabsorption was present in 50% of patients undergoing SeHCAT scanning. Almost 40% of those without risk factors had evidence of bile acid malabsorption, and in those meeting criteria for IBS-D prevalence was almost 30%.
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Diarrea/etiología , Esteatorrea/complicaciones , Esteatorrea/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Ácidos y Sales Biliares/metabolismo , Diarrea/complicaciones , Diarrea/epidemiología , Femenino , Humanos , Enfermedades Inflamatorias del Intestino/complicaciones , Enfermedades Inflamatorias del Intestino/epidemiología , Masculino , Persona de Mediana Edad , Pacientes Ambulatorios , Prevalencia , Factores de Riesgo , Adulto JovenRESUMEN
OBJECTIVE: To examine clinical correlates of juvenile-onset OCD across the lifespan. METHOD: Data collected at the intake interview from 257 consecutive participants with juvenile-onset OCD (20 children, 44 adolescents and 193 adults) in a naturalistic study of the clinical course of OCD were examined. Participants and parents of juvenile participants completed a structured diagnostic interview, rater-administered severity measures and self-report questionnaires. RESULTS: Children and adolescents (i.e. juveniles) shared similar features with the exception of age at onset and OCD symptom expression. Clinically meaningful differences between juvenile and adult participants were also found. Compared with adults, juveniles were more likely to be male, recall an earlier age at OCD onset and have different lifetime comorbidity patterns. CONCLUSION: Juvenile-onset OCD symptom expression is remarkably similar across the lifespan. However, findings also suggest clinically meaningful differences between juveniles and adults. Future work using a prospective design will improve our understanding of course patterns of juvenile-onset OCD.
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Trastorno Obsesivo Compulsivo/epidemiología , Adolescente , Adulto , Edad de Inicio , Anciano , Trastorno por Déficit de Atención con Hiperactividad/diagnóstico , Trastorno por Déficit de Atención con Hiperactividad/epidemiología , Trastorno por Déficit de Atención con Hiperactividad/psicología , Niño , Comorbilidad , Estudios Transversales , Trastornos de Alimentación y de la Ingestión de Alimentos/diagnóstico , Trastornos de Alimentación y de la Ingestión de Alimentos/epidemiología , Trastornos de Alimentación y de la Ingestión de Alimentos/psicología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Trastornos del Humor/diagnóstico , Trastornos del Humor/epidemiología , Trastornos del Humor/psicología , Trastorno Obsesivo Compulsivo/diagnóstico , Trastorno Obsesivo Compulsivo/psicología , Padres/psicología , Escalas de Valoración Psiquiátrica/estadística & datos numéricos , Estudios Retrospectivos , Autorrevelación , Índice de Severidad de la Enfermedad , Distribución por Sexo , Trastornos Relacionados con Sustancias/diagnóstico , Trastornos Relacionados con Sustancias/epidemiología , Trastornos Relacionados con Sustancias/psicología , Encuestas y CuestionariosRESUMEN
We introduce a novel two-dimensional (2D) homodyne and heterodyne technique for imaging objects through or embedded in a scattering medium. Our imaging approach is based on heterodyning of light with different Doppler broadenings that is scattered from objects of two different textures or from an opaque object and a textured scattering medium. We report on the initial demonstration of pulling signals out of noise for an object hidden behind a scattering medium. Enhancements of signal-to-noise ratio of the order of 50 have been achieved by use of a 2D holographic phase-sensitive detector. We also discuss the experimental feasibility of this approach for objects embedded in a scattering medium.
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An interlaboratory study describing the assignment of reference values to the extractable concentrations of metals in industrial sludge using NJDEP and USEPA methods is presented. Industrial waste containing high concentrations of alkali, alkaline earth, ferrous and transition metals was dried, size-reduced and homogenized. Multiple aliquots of this material were analyzed in two different government laboratories by several different combinations of extraction and analysis methodologies. Reference values for the acid-extractable concentrations of more than 15 metals were determined and will be included in the NIST Certificate of Analysis for SRM 2782, Industrial Sludge.
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A novel smart pixel-based neural network was realized experimentally. The matrix multiplication is split into positive and negative components and computed optically. The necessary subtraction, binarization, and transmission of the resulting matrices is accomplished via a prototype smart pixel spatial light modulator. The result is a neural network that performs truly parallel computation without requiring the use of an external processor.
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The development of reference materials to verify the determination of metals in sludge is described. Effluents from domestic and industrial treatment facilities were dried, size-reduced and homogenized. Multiple aliquots of each material were analyzed in two different government laboratories to determine reference values for the acid-extractable concentrations of more than 15 metals. These acid-extractable concentrations are distinct from total metal values. Different sample preparation and instrumental methods, along with internal quality assurance protocols, were used to confirm the results. The data show good agreement for most metals in the domestic material. Reference values for the leachable concentrations of several toxic metals and major constituents will become part of the Certificate of Analysis for Standard Reference Material (SRM) 2781 issued by the National Institute of Standards and Technology (NIST). Data for the candidate industrial sludge reference material are also presented and discussed.
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A method of implementing optical logic has been realized experimentally with a novel liquid crystal on silicon spatial light modulator with an integrated lens arrays. The device allows for three optical inputs and one optical output per pixel. The different logic functions realized, OR, and, nor, nand, and xor, are discussed.
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In this paper we present an analog winner-take-all MOS VLSI (metal-oxide semiconductor/very large scale integration) optoelectronic network. By varying either the input current or circuit parameters, the circuit can evidence several different behaviors such as contrast enhancement, strict winner-take-all, or winner-take-all with hysteresis. Simulation and experimental results from the prototype circuit are also discussed.
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The multiplicative and low-bandpass filtering characteristics of real-time holograms in photorefractive media are used as a basis for a baseband frequency demodulator by means of holographic homodyne detection. We experimentally demonstrate the demodulation of spatial bandpass signals in the kilohertz regime and homodyne detection in the gigahertz regime.
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We present the first all-optical nonlinear joint transform correlator based on a square-law receiver in the Fourier plane. Our device uses a photorefractive limiting quadratic processor. The compressional nonlinearity associated with the transfer function of the limiting quadratic processor enables the correlator to detect signals embedded in Gaussian and non-Gaussian noise. In the limiting region this device correlates the phase-only information of the input. This is the first time to our knowledge that photorefractives or real-time holography has been used in the correlation of the phase-only information. We demonstrate the operation of this device experimentally, and we evaluate its performance throughcomputer simulation for various forms of noise.
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Adaptive resonance architectures are neural nets that are capable of classifying arbitrary input patterns into stable category representations. A hybrid optoelectronic implementation utilizing an optical joint transform correlator is proposed and demonstrated. The resultant optoelectronic system is able to reduce the number of calculations compared to a strictly computer-based approach. The result is that, for larger images, the optoelectronic system is faster than the computer-based approach.
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An associative memory is implemented by using a binary phase-only filter as the memory element in a two-focal-length (2-f) correlator architecture. A sharp autocorrelation peak, combined with the 2-f architecture, allows the noise to be separated adequately from the signal such that a simple plane mirror can be used in the correlation plane instead of a nonlinearity.
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We describe a method for measuring the accuracy of aligners used to align lithographic patterns on opposite sides of a substrate (back-to-front aligners). The method, with minor modifications, can also be used as an aid in performing back-to-front alignments. The method is based on interferometric principles, is insensitive to manufacturing errors, and is simple to implement. The version described in this paper is fabricated by using binary optics technology and can measure the accuracy of aligners to +/-0.2 microm.
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We report self-pumped optical phase conjugation in which the pumps are self-induced as standing waves in a linear Raman laser. Self-pumped reflectivities approaching 5% are obtained for input intensities of 20 W/cm(2). This low optical input intensity combined with predicted submicrosecond response times suggests that the resonant Raman interaction may provide the basis for a promising new class of nonlinear-optical material.