Computation of the conformal algebra of 1+3 decomposable spacetimes

The conformal algebra of a 1+3 decomposable spacetime can be computed from the conformal Killing vectors (CKV) of the 3-space. It is shown that the general form of such a 3-CKV is the sum of a gradient CKV and a Killing or homothetic 3-vector. It is proved that spaces of constant curvature always admit such conformal Killing vectors. As an example, the complete conformal algebra of a G\"odel-type spacetime is computed. Finally it is shown that this method can be extended to compute the conformal algebra of more general non-decomposable spacetimes.Comment: 15 pages Latex, no figures. Minor mistakes correcte

Intensive Care Management of The Critically Ill Elderly Population: The Case of ‘Sotiria’ Regional Chest Diseases Hospital of Athens, Greece

The aim of this study was to assess the characteristics and short-term outcome of elderly patients admitted to the ICU of ‘Sotiria’ Regional Chest Diseases Hospital of Athens. We examined retrospectively the records of 344 patients aged ≥70 years old admitted to the ICU of a tertiary hospital during a five-year period, from 2009-2013. We reported demographic and clinical data, length of ICU stay, need for mechanical ventilation and ICU mortality. Among 1730 admitted to the ICU during this period, the elderly comprised 344 (19.8%). The main causes of ICU admission were Chronic Obstructive Pulmonary Disease (COPD) exacerbation (n=169), postoperative respiratory failure (n=78), acute respiratory failure of various etiologies (n=76) and cardiogenic pulmonary edema (n=25). Overall mortality rate of elderly patients was 41.5%. According to age groups, 200 patients were 70-74 years old with a mortality rate of 47%, 42 patients were 80-84 years old presenting a mortality rate of 28.5%, while 14 patients aged over 85 years old, presented a mortality of 42.8%. The mean length of ICU stay (LOS) for the elderly patients was 11.2 days, while the corresponding LOS value for younger patients was 8.1 days. Elderly patients present highest mortality than younger population. However, mortality does not correlate exclusively with advancing age over 70 years, but mostly with the underlying disease. Therefore, age should not be the sole determinant of ICU admission

Strong-field effects induced in the extreme ultraviolet domain

Motivated by the achieved high intensities of novel extreme ultraviolet (XUV) radiation sources, such as free electron lasers and laser-driven high harmonic generation beamlines, we elaborate on their perspective in inducing observable strong field effects. The feasibility of extending such effects from the infrared and visible spectral regimes in the XUV domain is supported through numerically calculated models of near-future experiments. We highlight the advancement of performing studies in the time domain, using ultra-short XUV pulses, which allows for the temporal evolution of such effects to be followed. Experimental and theoretical obstacles and limitations are further discussed. © The Author(s), 2020. Published by Cambridge University Press in association with Chinese Laser Press

Large infrapatellar ganglionic cyst of the knee fat pad: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Large ganglionic cystic formations arising from the infrapatellar fat pad are quite uncommon and only a few are mentioned in the literature. An open excision in these cases is mandatory.</p> <p>Case presentation</p> <p>We report the case of a large infrapatellar fat pad ganglion in a 37-year-old Greek man with chronic knee discomfort. The ganglionic cyst originated from the infrapatellar fat pad and had no intrasynovial extension. The final diagnosis was determined with magnetic resonance imaging of the knee, and the lesion was treated with surgery.</p> <p>Conclusions</p> <p>These lesions are asymptomatic in most cases but often are misdiagnosed as meniscal or ligamentous lesions of the knee joint. Nowadays, the therapeutic trend for such lesions is arthroscopic excision, but when there is a large ganglion, as in this case report, the treatment should be an open and thorough resection. This report is intended mostly but not exclusively for clinical physicians and radiologists.</p

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Physiological parameters for Prognosis in Abdominal Sepsis (PIPAS) Study : a WSES observational study

BackgroundTiming and adequacy of peritoneal source control are the most important pillars in the management of patients with acute peritonitis. Therefore, early prognostic evaluation of acute peritonitis is paramount to assess the severity and establish a prompt and appropriate treatment. The objectives of this study were to identify clinical and laboratory predictors for in-hospital mortality in patients with acute peritonitis and to develop a warning score system, based on easily recognizable and assessable variables, globally accepted.MethodsThis worldwide multicentre observational study included 153 surgical departments across 56 countries over a 4-month study period between February 1, 2018, and May 31, 2018.ResultsA total of 3137 patients were included, with 1815 (57.9%) men and 1322 (42.1%) women, with a median age of 47years (interquartile range [IQR] 28-66). The overall in-hospital mortality rate was 8.9%, with a median length of stay of 6days (IQR 4-10). Using multivariable logistic regression, independent variables associated with in-hospital mortality were identified: age > 80years, malignancy, severe cardiovascular disease, severe chronic kidney disease, respiratory rate >= 22 breaths/min, systolic blood pressure 4mmol/l. These variables were used to create the PIPAS Severity Score, a bedside early warning score for patients with acute peritonitis. The overall mortality was 2.9% for patients who had scores of 0-1, 22.7% for those who had scores of 2-3, 46.8% for those who had scores of 4-5, and 86.7% for those who have scores of 7-8.ConclusionsThe simple PIPAS Severity Score can be used on a global level and can help clinicians to identify patients at high risk for treatment failure and mortality.Peer reviewe