Scintillating properties of frozen new liquid scintillators

The light emission from scintillators which are liquid at room temperature was studied in the interval between $+20$~$^{\circ}$C and $-120$~$^{\circ}$C, where the phase transition from liquid to solid takes place. The light yield measured at $-120$~$^{\circ}$C is about twice as much as that observed at $+20$~$^{\circ}$C. By cooling the scintillator from $+20$~$^{\circ}$C to $-120$~$^{\circ}$C and then heating it from $-120$~$^{\circ}$C to $+20$~$^{\circ}$C, the light yield varies in steps at well defined temperatures, which are different for the cooling and heating processes. These hysteresis phenomena appear to be related to the solvent rather than to the dopant. The decay time of scintillation light was measured at $+20$~$^{\circ}$C and $-120$~$^{\circ}$C. Whilst at room temperature most of the light is emitted with a decay time of 6--8 ns, at $-120$~$^{\circ}$C a slower component, with a decay time of 25--35 ns, becomes important

Ressecção parcial e omentalização de cisto prostático de retenção em três cães

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Insecure adult attachment and reflective functioning as mechanisms of the relationship between traumatic life events and suicidal ideation: A path analysis

The relationship between traumatic life events and increased suicide risk has been well reported in literature. However, the complex nature of suicidality phenomena still hinders our ability to comprehend the mediation mechanism underlying this association. In this study, we examined the mediating role of adult attachment and reflective functioning in the relationship between traumatic life events and suicidal ideation. Nine hundred and fifty Italian adults completed an online survey evaluating traumatic life events, adult attachment, reflective functioning and suicidal ideation. The path analysis showed that the positive relationship between traumatic life events and suicidal ideation was partially mediated by attachment anxiety and reflective functioning. From a clinical point of view, these results support the relevance of evaluating and improving patients’ ability to mentalize as a part of psychotherapeutic intervention aimed at reducing suicidality in people with a history of traumatic experiences and attachment anxiety

Peritonite biliar como complicação de colecistectomia

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Ureterotomia como tratamento de obstrução ureteral em dois cães

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The Megapixel EBCCD: a high-resolution imaging tube sensitive to single photons

A hybrid image-intensifier tube, suitable for extremely low-light imaging, has been tested. This device is based on an Electron-Bombarded CCD chip (EBCCD) with $1024 \times 1024$ sensitive pixe ls. The tube, which has a photocathode diameter of 40 mm, is gateable and zoomable, with an image magnification varying from 0.62 to 1.3. The high gain (about 4000 collected electrons per photo electron at the operational voltage of 15 kV) and the relatively low noise (180 electrons per pixel at 10 MHz pixel-readout frequency), allows single-photoelectron signals to be separated from n oise with a signal-to-noise ratio greater than 10. By applying an appropriate threshold on the signal amplitude, the background can almost be eliminated, with a loss of few percent in single-ph otoelectron counting. High inner gain, low noise, single-photoelectron sensitivity, and high spatial resolution make the EBCCD imaging tube a unique device, attractive for many applications in h igh-energy physics, astrophysics, biomedical diagnostics

Direct measurement of the L/K ratio in the electron capture decay of 7Be7Be with cryogenic micro-calorimeters

Using a cryogenic micro-calorimeter originally developed for x-ray astrophysics, we have the performed the first direct investigation of the L/K capture ratio in 7Be7Be electron capture decay. The low background and excellent energy resolution clearly resolve capture from the individual shells, resulting in a direct determination of the L/K ratio. © 2002 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87662/2/473_1.pd

Aspectos ultra-sonográficos modo B, doppler colorido e power doppler nas alterações focais e/ou multifocais do parênquima esplênico de cães com suspeita de processos neoplásicos não linfóides

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A Study of Time-Dependent CP-Violating Asymmetries and Flavor Oscillations in Neutral B Decays at the Upsilon(4S)

We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample consists of 29.7 ${\rm fb}^{-1}$ recorded at the $\Upsilon(4S)$ resonance and 3.9 ${\rm fb}^{-1}$ off-resonance. One of the neutral B mesons, which are produced in pairs at the $\Upsilon(4S)$, is fully reconstructed in the CP decay modes $J/\psi K^0_S$, $\psi(2S) K^0_S$, $\chi_{c1} K^0_S$, $J/\psi K^{*0}$ ($K^{*0}\to K^0_S\pi^0$) and $J/\psi K^0_L$, or in flavor-eigenstate modes involving $D^{(*)}\pi/\rho/a_1$ and $J/\psi K^{*0}$ ($K^{*0}\to K^+\pi^-$). The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. The proper time elapsed between the decays is determined by measuring the distance between the decay vertices. A maximum-likelihood fit to this flavor eigenstate sample finds $\Delta m_d = 0.516\pm 0.016 {\rm (stat)} \pm 0.010 {\rm (syst)} {\rm ps}^{-1}$. The value of the asymmetry amplitude $\sin2\beta$ is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor-eigenstate sample and about 642 tagged $B^0$ decays in the CP-eigenstate modes. We find $\sin2\beta=0.59\pm 0.14 {\rm (stat)} \pm 0.05 {\rm (syst)}$, demonstrating that CP violation exists in the neutral B meson system. (abridged)Comment: 58 pages, 35 figures, submitted to Physical Review

Measurement of the Branching Fraction for B- --> D0 K*-

We present a measurement of the branching fraction for the decay B- --> D0 K*- using a sample of approximately 86 million BBbar pairs collected by the BaBar detector from e+e- collisions near the Y(4S) resonance. The D0 is detected through its decays to K- pi+, K- pi+ pi0 and K- pi+ pi- pi+, and the K*- through its decay to K0S pi-. We measure the branching fraction to be B.F.(B- --> D0 K*-)= (6.3 +/- 0.7(stat.) +/- 0.5(syst.)) x 10^{-4}.Comment: 7 pages, 1 postscript figure, submitted to Phys. Rev. D (Rapid Communications