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1.
Phys Rev Lett ; 121(22): 221301, 2018 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-30547645

RESUMEN

We present results from an analysis of all data taken by the bicep2/Keck CMB polarization experiments up to and including the 2015 observing season. This includes the first Keck Array observations at 220 GHz and additional observations at 95 and 150 GHz. The Q and U maps reach depths of 5.2, 2.9, and 26 µK_{CMB} arcmin at 95, 150, and 220 GHz, respectively, over an effective area of ≈400 square degrees. The 220 GHz maps achieve a signal to noise on polarized dust emission approximately equal to that of Planck at 353 GHz. We take auto and cross spectra between these maps and publicly available WMAP and Planck maps at frequencies from 23 to 353 GHz. We evaluate the joint likelihood of the spectra versus a multicomponent model of lensed-ΛCDM+r+dust+synchrotron+noise. The foreground model has seven parameters, and we impose priors on some of these using external information from Planck and WMAP derived from larger regions of sky. The model is shown to be an adequate description of the data at the current noise levels. The likelihood analysis yields the constraint r_{0.05}<0.07 at 95% confidence, which tightens to r_{0.05}<0.06 in conjunction with Planck temperature measurements and other data. The lensing signal is detected at 8.8σ significance. Running a maximum likelihood search on simulations we obtain unbiased results and find that σ(r)=0.020. These are the strongest constraints to date on primordial gravitational waves.

2.
Phys Rev Lett ; 116(3): 031302, 2016 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-26849583

RESUMEN

We present results from an analysis of all data taken by the BICEP2 and Keck Array cosmic microwave background (CMB) polarization experiments up to and including the 2014 observing season. This includes the first Keck Array observations at 95 GHz. The maps reach a depth of 50 nK deg in Stokes Q and U in the 150 GHz band and 127 nK deg in the 95 GHz band. We take auto- and cross-spectra between these maps and publicly available maps from WMAP and Planck at frequencies from 23 to 353 GHz. An excess over lensed ΛCDM is detected at modest significance in the 95×150 BB spectrum, and is consistent with the dust contribution expected from our previous work. No significant evidence for synchrotron emission is found in spectra such as 23×95, or for correlation between the dust and synchrotron sky patterns in spectra such as 23×353. We take the likelihood of all the spectra for a multicomponent model including lensed ΛCDM, dust, synchrotron, and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r) using priors on the frequency spectral behaviors of dust and synchrotron emission from previous analyses of WMAP and Planck data in other regions of the sky. This analysis yields an upper limit r_{0.05}<0.09 at 95% confidence, which is robust to variations explored in analysis and priors. Combining these B-mode results with the (more model-dependent) constraints from Planck analysis of CMB temperature plus baryon acoustic oscillations and other data yields a combined limit r_{0.05}<0.07 at 95% confidence. These are the strongest constraints to date on inflationary gravitational waves.

3.
Phys Rev Lett ; 112(24): 241101, 2014 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-24996078

RESUMEN

We report results from the BICEP2 experiment, a cosmic microwave background (CMB) polarimeter specifically designed to search for the signal of inflationary gravitational waves in the B-mode power spectrum around ℓ∼80. The telescope comprised a 26 cm aperture all-cold refracting optical system equipped with a focal plane of 512 antenna coupled transition edge sensor 150 GHz bolometers each with temperature sensitivity of ≈300 µK(CMB)√s. BICEP2 observed from the South Pole for three seasons from 2010 to 2012. A low-foreground region of sky with an effective area of 380 square deg was observed to a depth of 87 nK deg in Stokes Q and U. In this paper we describe the observations, data reduction, maps, simulations, and results. We find an excess of B-mode power over the base lensed-ΛCDM expectation in the range 30 < ℓ < 150, inconsistent with the null hypothesis at a significance of >5σ. Through jackknife tests and simulations based on detailed calibration measurements we show that systematic contamination is much smaller than the observed excess. Cross correlating against WMAP 23 GHz maps we find that Galactic synchrotron makes a negligible contribution to the observed signal. We also examine a number of available models of polarized dust emission and find that at their default parameter values they predict power ∼(5-10)× smaller than the observed excess signal (with no significant cross-correlation with our maps). However, these models are not sufficiently constrained by external public data to exclude the possibility of dust emission bright enough to explain the entire excess signal. Cross correlating BICEP2 against 100 GHz maps from the BICEP1 experiment, the excess signal is confirmed with 3σ significance and its spectral index is found to be consistent with that of the CMB, disfavoring dust at 1.7σ. The observed B-mode power spectrum is well fit by a lensed-ΛCDM+tensor theoretical model with tensor-to-scalar ratio r = 0.20_(-0.05)(+0.07), with r = 0 disfavored at 7.0σ. Accounting for the contribution of foreground, dust will shift this value downward by an amount which will be better constrained with upcoming data sets.

4.
Eur Neuropsychopharmacol ; 8(4): 297-302, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9928920

RESUMEN

The antinociceptive effects of the tetracyclic antidepressant mianserin and its interaction with various opioid receptor subtypes was evaluated. Mice were tested with a hotplate analgesia meter. Mianserin elicited an antinociceptive effect in a dose-dependent manner following doses from 1-25 mg/kg. As the mianserin dose increased beyond 30 mg/kg, latencies returned to baseline, yielding a biphasic effect. This effect of mianserin was antagonized by naloxone (P<0.005), implying a possible opioid mechanism of action involved in the mianserin induced antinociceptive effect. When administered with various opioid antagonists, the sensitivity of mianserin to selective opioid antagonists was found significant for mu and kappa1 opioid receptor subtypes (P<0.005), but not for delta-receptor. At the next stage mianserin was administered together with various agonists of opioid receptors. When administered together with opiates, mianserin significantly potentiates analgesia at the mu, kappa1 and kappa3 opioid receptor subtype (P<0.005) and to a lesser extent, at the delta opioid receptors. These results suggest a potential use of mianserin in the management of some pain syndromes. However, further research is needed in order to establish both the exact clinical indications and the effective doses of mianserin when prescribed for pain.


Asunto(s)
Antidepresivos de Segunda Generación/farmacología , Mianserina/farmacología , Receptores Opioides/efectos de los fármacos , Animales , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Masculino , Ratones , Ratones Endogámicos ICR , Antagonistas de Narcóticos/farmacología , Dimensión del Dolor
5.
Am Surg ; 67(8): 772-3, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11510581

RESUMEN

Nasoenteral tubes are placed routinely for feeding in patients in intensive care units and medical-surgical floor settings. Safe placement in the stomach/postpyloric location is performed by a wide array of medical personnel. We report a patient with placement of a nasoenteral tube into the pleural cavity.


Asunto(s)
Nutrición Enteral/efectos adversos , Neumotórax/etiología , Anciano , Femenino , Humanos , Neumotórax/diagnóstico
6.
J Laparoendosc Adv Surg Tech A ; 11(4): 255-8, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11569518

RESUMEN

BACKGROUND: Crohn's disease confined to the appendix is rare but has been well described in the literature. It can mimic acute appendicitis clinically. After surgical treatment, recurrences of Crohn's disease are rare. We report the first case of treatment by laparoscopic appendectomy of Crohn's disease confined to the appendix. METHODS: A healthy 32-year old man presented with a week-long history of vague lower abdominal pain. Diagnostic work-up, which included CT, enteroclysis, and routine blood work, revealed a patent appendiceal lumen with an inflammatory mass in the right lower quadrant. RESULTS: Diagnostic laparoscopy revealed an inflamed appendix, and a laparoscopic appendectomy was performed, with frozen-section examination revealing Crohn's disease of the appendix. Two years after surgery, the patient has not had a recurrence of symptoms. CONCLUSIONS: Crohn's disease of the appendix can mimic acute appendicitis, although often with a more indolent course. The disease may be treated successfully by laparoscopic appendectomy, with good long-term results.


Asunto(s)
Apendicectomía/métodos , Apendicitis/cirugía , Enfermedad de Crohn/cirugía , Laparoscopía , Enfermedad Aguda , Adulto , Apendicitis/etiología , Enfermedad de Crohn/complicaciones , Humanos , Masculino
9.
Dig Surg ; 18(2): 142-6, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11351161

RESUMEN

BACKGROUND/AIMS: Inflammatory fibrous polyps (IFPs), also known as inflammatory pseudotumors, occur rarely in the gastrointestinal tract. IFPs have variable presentations, often presenting as small bowel obstruction due to intussusception or, less commonly, as an incidental finding on radiological examinations or screening colonoscopies. The diagnosis and management of IFPs will be discussed through a review of the literature and a series of cases from our own institution. METHODS: A retrospective analysis of the diagnosis, management and complications of IFPs was performed by a literature review. This was accompanied by a series of 3 cases of IFPs, 2 of which causing intussusception, diagnosed and treated in our own institution. CONCLUSIONS: IFP is a rare disease and has a variable presentation, from asymptomatic to small bowel obstruction due to intussusception. IFPs cannot be differentiated from malignancy without histological examination. Therefore, whether diagnosed incidentally or in the setting of intussusception, the treatment of IFPs is surgical resection of the involved bowel.


Asunto(s)
Enfermedades del Colon/complicaciones , Enfermedades del Colon/diagnóstico , Granuloma de Células Plasmáticas/complicaciones , Granuloma de Células Plasmáticas/diagnóstico , Enfermedades del Íleon/complicaciones , Enfermedades del Íleon/diagnóstico , Intususcepción/etiología , Enfermedades del Yeyuno/complicaciones , Enfermedades del Yeyuno/diagnóstico , Adulto , Biopsia , Enfermedades del Colon/cirugía , Colonoscopía , Femenino , Granuloma de Células Plasmáticas/cirugía , Humanos , Enfermedades del Íleon/cirugía , Enfermedades del Yeyuno/cirugía , Laparoscopía , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos X
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