1,345 research outputs found

    Search for the Lepton-Number-Violating Decay Ξ-→pμ-μ-

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    A sensitive search for the lepton-number-violating decay Ξ-→pμ-μ- has been performed using a sample of ∼109  Ξ- hyperons produced in 800  GeV/c p-Cu collisions. We obtain B(Ξ-→pμ-μ-)\u3c4.0×10-8 at 90% confidence, improving on the best previous limit by 4 orders of magnitude

    Novel Approach for Diagnosis of Brain Diseases byUsing Mixed Scheme on MRI and CT Images

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    Now days, multimodal medical image has growing interest in the field of analysis and diagnosis of brain diseases. In order to obtain complementary information from multimodal input images, multimodal image fusion become widely popular. Here fusion of the input multimodal images is done either by Spatial Domain or by Transform Domain method. Limitations of Spatial domain method force us to use transform domain fusion method. Discrete Wavelet Transform is one of the popular real valued wavelet transform method of transform domain fusion, but it has disadvantages like shift sensitivity and lack of phase information. These disadvantages motivate us to use the complex Wavelet Transform. In the present work we prefer New Daubechies Complex Wavelet Transform (DCxWT) Method for multimodal image fusion.shift invariance and availability of phase information properties of DCxWT create an output fused image of greater quality. In this work we apply two separate image fusion rule for approximation and detailed coefficient

    Redox and catalytic chemistry of Ti in titanosilicate molecular sieves: an EPR investigation

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    An EPR study of Ti3+ in titanosilicate molecular sieves, TS-1, TiMCM-41, ETS-10 and ETS-4 is reported. Ti4+ is reduced to Ti3+ by dry hydrogen above 673 K. Ti ions in TS-1 and TiMCM-41 are located in tetragonally elongated Td and those of ETS-10 and ETS-4 in a tetragonally compressed Oh geometric positions. Reduction at 873 K revealed the presence of two non-equivalent Ti3+ sites in TS-1 and TiMCM-41. Ti4+ ions in a tetrahedral geometry are more difficult to reduce than in an octahedral symmetry. The effects of cation exchange and Pt impregnation, on the geometry and reducibility of titanium in ETS-10, are also examined. Interaction of a tetrahedrally coordinated Ti3+ with O2 or H2O2 results in a diamagnetic titanium(IV) hydroperoxo species. Under the same conditions, an octahedrally coordinated Ti3+ forms a paramagnetic titanium(IV) superoxo species. The higher catalytic activity of TS-1 and TiMCM-41 in selective oxidation reactions is probably a consequence of the formation of the hydroperoxy species on their surface during the catalytic reaction. The presence of Pt in the vicinity of Ti enables the use of H2 and O2 (instead of H2O2) to generate the active hydroperoxy site. The absence of formation of titanium hydroperoxy species in ETS-4 and ETS-10 is the cause of their inactivity in selective oxidation reactions

    Characterization of proliferative, glial and angiogenic responses after a CoCl2-induced injury of photoreceptor cells in the adult zebrafish retina

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    The adult zebrafish is considered a useful model for studying mechanisms involved in tissue growth and regeneration. We have characterized cytotoxic damage to the retina of adult zebrafish caused by the injection of cobalt chloride (CoCl2) into the vitreous cavity. The CoCl2 concentration we used primarily caused injury to photoreceptors. We observed the complete disappearance of cones, followed by rods, across the retina surface from 28 to 96 hr after CoCl2 injury. The loss of 30% of bipolar cells was also observed by 50 hr after lesion (hpl). CoCl2 injury provoked a strong induction of the proliferative activity of multipotent Müller glia and derived progenitors. The effect of CoCl2 on retina cells was significantly reduced by treatment with glutamate ionotropic receptor antagonists. Cone photoreceptor regeneration occurred 25 days after injury. Moreover, a single dose of CoCl2 induced vascular damage and regeneration, whereas three injections of CoCl2 administered weekly provoked neovascular-like changes 20 days after injury. CoCl2 injury also caused microglial reactivity in the optic disc, retina periphery and fibre layer. CoCl2-induced damage enhanced pluripotency and proneural transcription factor gene expression in the mature retina 72 hpl. Tumour necrosis factor alpha, vascular endothelial growth factor (VEGF) and VEGF receptor mRNA levels were also significantly enhanced by 72 hpl. The injury paradigm we have described in this work may be useful for the discovery of signalling molecules and pathways that participate in the regenerative response and it may serve as a model to screen for compounds that could potentially treat aberrant angiogenesis.Fil: Medrano, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Pisera Fuster, Antonella. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Sanchis, Pablo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Paez, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Bernabeu, Ramon Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Faillace, Maria Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; Argentin

    Commelina badamica (Commelinaceae), a new species from India

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    A new species, Commelina badamica from the sandstone plateaus of Badami, Karnataka, India is described and illustrated. C. badamica is similar to C. clavata and C. diffusa, but differs in indefinite habit; linear–narrowly lanceolate leaves; puberulous or velutinous to tomentose spathes; clawless petals; velutinous ovary; radiately tri-lobed stigma; one capsule per spathe and trapezoidal, ventrally truncate seeds

    Non-invasive methods for the estimation of mPAP in COPD using Cardiovascular Magnetic Resonance Imaging

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    Purpose Pulmonary hypertension (PH) is associated with a poor outcome in chronic obstructive pulmonary disease (COPD) and is diagnosed invasively. We aimed to assess the diagnostic accuracy and prognostic value of non-invasive cardiovascular magnetic resonance (CMR) models. Methods Patients with COPD and suspected PH, who underwent CMR and right heart catheter (RHC) were identified. Three candidate models were assessed: 1, CMR-RV model, based on right ventricular (RV) mass and interventricular septal angle; 2, CMR PA/RV includes RV mass, septal angle and pulmonary artery (PA) measurements; 3, the Alpha index, based on RV ejection fraction and PA size. Results Of 102 COPD patients, 87 had PH. The CMR-PA/RV model had the strongest diagnostic accuracy (sensitivity 92%, specificity 80%, positive predictive value 96% and negative predictive value 63%, AUC 0.93, p<0.0001). Splitting RHCmPAP, CMR-RV and CMR-PA/RV models by 35mmHg gave a significant difference in survival, with log-rank chi-squared 5.03, 5.47 and 7.10. RV mass and PA relative area change were the independent predictors of mortality at multivariate Cox regression (p=0.002 and 0.030). Conclusion CMR provides diagnostic and prognostic information in PH-COPD. The CMR-PA/RV model is useful for diagnosis, the RV mass index and PA relative area change are useful to assess prognosis. Key Points • Pulmonary hypertension is a marker of poor outcome in COPD. • MRI can predict invasively measured mean pulmonary artery pressure. • Cardiac MRI allows for estimation of survival in COPD. • Cardiac MRI may be useful for follow up or future trials. • MRI is potentially useful to assess pulmonary hypertension in patients with COPD
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