RESUMO
Electrically charged particles can be created by the decay of strong enough electric fields, a phenomenon known as the Schwinger mechanism1. By electromagnetic duality, a sufficiently strong magnetic field would similarly produce magnetic monopoles, if they exist2. Magnetic monopoles are hypothetical fundamental particles that are predicted by several theories beyond the standard model3-7 but have never been experimentally detected. Searching for the existence of magnetic monopoles via the Schwinger mechanism has not yet been attempted, but it is advantageous, owing to the possibility of calculating its rate through semi-classical techniques without perturbation theory, as well as that the production of the magnetic monopoles should be enhanced by their finite size8,9 and strong coupling to photons2,10. Here we present a search for magnetic monopole production by the Schwinger mechanism in Pb-Pb heavy ion collisions at the Large Hadron Collider, producing the strongest known magnetic fields in the current Universe11. It was conducted by the MoEDAL experiment, whose trapping detectors were exposed to 0.235 per nanobarn, or approximately 1.8 × 109, of Pb-Pb collisions with 5.02-teraelectronvolt center-of-mass energy per collision in November 2018. A superconducting quantum interference device (SQUID) magnetometer scanned the trapping detectors of MoEDAL for the presence of magnetic charge, which would induce a persistent current in the SQUID. Magnetic monopoles with integer Dirac charges of 1, 2 and 3 and masses up to 75 gigaelectronvolts per speed of light squared were excluded by the analysis at the 95% confidence level. This provides a lower mass limit for finite-size magnetic monopoles from a collider search and greatly extends previous mass bounds.
RESUMO
PURPOSE: The aim of this study was to evaluate the 5-year recurrence rate of pilonidal sinus disease (PSD) after endoscopic sinusectomy and identify risk factors for recurrence. METHODS: All consecutive patients from September 2011 through December 2017 who underwent endoscopic sinusectomy at seven referral centres for pilonidal sinus treatment were retrospectively analysed from a prospectively maintained database. RESULTS: Out of 290 patients (185 males versus 105 female, with a mean age of 25.5±6.9), 73 presented recurrence at 5-year follow-up with a recurrence rate of 25.2%. The number of pilonidal sinus with pits off the midline (p = 0.001) and the mean (SD) distance from the most lateral orifice to the midline (p = 0.001) were higher in the group of patients with recurrence at 5-year follow-up. Multivariate analysis demonstrated that the position of the pits off the midline (p = 0.001) and the distance of the most lateral orifice from the midline (p = 0.001) were independent risk factors for recurrence at 5-year follow-up. Receiver operating characteristic (ROC) curve analysis showed that the distance of lateral orifice from midline predicted an 82.2% possibility of recurrence at 5-year follow-up and Youden's test identified the best cut-off as 2 cm for this variable. Out of 195 cases with the most lateral orifice less than 2 cm from the midline, 13 presented recurrence at 5-year follow-up with a recurrence rate of 6.7%. Out of 95 cases with the most lateral orifice more than 2 cm from midline, 60 showed recurrence at 5-year follow-up with a recurrence rate of 63.2%. CONCLUSIONS: This data may help guide which disease characteristics predict the optimal use of an endoscopic pilonidal sinus technique.
Assuntos
Seio Pilonidal , Dermatopatias , Masculino , Humanos , Feminino , Adolescente , Adulto Jovem , Adulto , Seio Pilonidal/cirurgia , Estudos Retrospectivos , Bases de Dados Factuais , Análise MultivariadaRESUMO
The MoEDAL trapping detector consists of approximately 800 kg of aluminum volumes. It was exposed during run 2 of the LHC program to 6.46 fb^{-1} of 13 TeV proton-proton collisions at the LHCb interaction point. Evidence for dyons (particles with electric and magnetic charge) captured in the trapping detector was sought by passing the aluminum volumes comprising the detector through a superconducting quantum interference device (SQUID) magnetometer. The presence of a trapped dyon would be signaled by a persistent current induced in the SQUID magnetometer. On the basis of a Drell-Yan production model, we exclude dyons with a magnetic charge ranging up to five Dirac charges (5g_{D}) and an electric charge up to 200 times the fundamental electric charge for mass limits in the range 870-3120 GeV and also monopoles with magnetic charge up to and including 5g_{D} with mass limits in the range 870-2040 GeV.
RESUMO
MoEDAL is designed to identify new physics in the form of stable or pseudostable highly ionizing particles produced in high-energy Large Hadron Collider (LHC) collisions. Here we update our previous search for magnetic monopoles in Run 2 using the full trapping detector with almost four times more material and almost twice more integrated luminosity. For the first time at the LHC, the data were interpreted in terms of photon-fusion monopole direct production in addition to the Drell-Yan-like mechanism. The MoEDAL trapping detector, consisting of 794 kg of aluminum samples installed in the forward and lateral regions, was exposed to 4.0 fb^{-1} of 13 TeV proton-proton collisions at the LHCb interaction point and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges equal to or above the Dirac charge are excluded in all samples. Monopole spins 0, ½, and 1 are considered and both velocity-independent and-dependent couplings are assumed. This search provides the best current laboratory constraints for monopoles with magnetic charges ranging from two to five times the Dirac charge.
RESUMO
Neutrino telescopes are designed to search for neutrino sources in the Universe, exploiting the Cherenkov light emitted along the path of the charged particles produced in interactions occurring close to the detector volume. Their huge size and the shield offered by large water or ice overburden make them excellent tools to search for exotic and rare particles in the cosmic radiation. In particular, they are sensitive to particles not predicted by the Standard Model that could be messenger of new physics. An overview of the experimental scenario and the relevant results obtained looking for magnetic monopoles, dark matter candidates and other exotic relic particles with neutrino telescopes is given, together with the description of possible new perspectives. This article is part of a discussion meeting issue 'Topological avatars of new physics'.
RESUMO
MoEDAL is designed to identify new physics in the form of long-lived highly ionizing particles produced in high-energy LHC collisions. Its arrays of plastic nuclear-track detectors and aluminium trapping volumes provide two independent passive detection techniques. We present here the results of a first search for magnetic monopole production in 13 TeV proton-proton collisions using the trapping technique, extending a previous publication with 8 TeV data during LHC Run 1. A total of 222 kg of MoEDAL trapping detector samples was exposed in the forward region and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges exceeding half the Dirac charge are excluded in all samples and limits are placed for the first time on the production of magnetic monopoles in 13 TeV pp collisions. The search probes mass ranges previously inaccessible to collider experiments for up to five times the Dirac charge.
RESUMO
OBJECTIVES: to evaluate the differences in clinical characteristics and risk factors of delirium in elderly medical inpatients according to the presence or not of dementia. DESIGN: cross-sectional, observational study. SETTING: acute medical care unit (ACU) of a general hospital. PARTICIPANTS: 330 patients aged 65 and older consecutively admitted on a 24-week period. MEASUREMENTS: Functional status, cognitive abilities, severity of acute illness (Acute Physiology, Age and Chronic Health Evaluation (APACHE II) score), Confusion Assessment Method (CAM), Delirium Rating Scale (DRS) and One Day Fluctuation Scale (ODFS). RESULTS: patients with delirium represent 19.1% of the sample, 41.0% of which had also dementia. Hyperactive form of delirium was 41.0%; hypoactive 11.0% and mixed 48.0%. In non demented patients, the delirious patients showed higher APACHE II score, more severe functional decline, poorer cognitive status respect to not delirious. In demented patients no differences were found in APACHE II score and cognitive status among delirious and not delirious subjects. In this group, functional decline (p = .012), acute infection (p = .007), psychotropic drugs use (p = .028) and severe hypoalbuminemia (p = .036) represented risk factors for the onset of delirium. Demented patients had higher perceptual disturbances (p = .040) and less severe delusions (p = .001), while total DRS score do not differs in the two groups. According to ODFS, delirium episode was more fluctuating in patients with dementia. CONCLUSION: clinical characteristics and risk factors of delirium are different in demented and not demented elderly inpatients. Patients with dementia are vulnerable to delirium at lower levels of medical acuity than non-demented patients.
Assuntos
Cognição/fisiologia , Delírio/epidemiologia , Demência/epidemiologia , Avaliação Geriátrica , Transtornos Psicomotores/epidemiologia , APACHE , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Estudos Transversais , Feminino , Hospitalização , Humanos , Tempo de Internação , Masculino , Escalas de Graduação Psiquiátrica , Fatores de RiscoRESUMO
The improvement of results and patients quality life is the aim of surgical technique. Mini-laparoscopic cholecystectomy brings not only to a better cosmetic results, but also to a decrease of post operative pain, analgesic use, hospital stay and an early return to normal activities. In this study, Authors report their own experience about mini-laparoscopic cholecystectomy using 5 mm and 3 mm trocar. Patients suffering from biliary sludge, microscopic lithiasis and mild or moderate gallbladder inflammation can undergo this procedure.
Assuntos
Colecistectomia Laparoscópica , Colecistectomia Laparoscópica/instrumentação , Colecistectomia Laparoscópica/métodos , Colelitíase/cirurgia , Doenças da Vesícula Biliar/cirurgia , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos , Qualidade de VidaAssuntos
Clareamento Dental/métodos , Adulto , Cor , Feminino , Géis , Humanos , Concentração de Íons de Hidrogênio , Luz , Masculino , Pessoa de Meia-Idade , Oxidantes/administração & dosagem , Oxidantes/uso terapêutico , Satisfação do Paciente , Peróxidos/administração & dosagem , Peróxidos/uso terapêutico , Fotografação , Fatores de Tempo , Clareamento Dental/instrumentação , Descoloração de Dente/terapiaRESUMO
A histopathological study of 125 cases of basal cell carcinoma (BCC; out of 5,475 over a period of 5 years) occurring on the leg was performed. Nodular and superficial BCC were the most common patterns. No sclerosing type was observed, although prominent fibrosis was present in some cases of BCC associated with severe stasis changes. Stasis changes were found only in 25% of the cases suggesting that they do not represent a predisposing factor for the development of BCC on the leg.