180 research outputs found
Clinical Characteristics and prognostic factors for Intensive Care Unit Admission of Patients With COVID-19. Retrospective Study Using Machine Learning and Natural Language Processing.
13 p.Background: Many factors involved in the onset and clinical course of the ongoing COVID-19 pandemic are still unknown. Although big data analytics and artificial intelligence are widely used in the realms of health and medicine, researchers are only beginning to use these tools to explore the clinical characteristics and predictive factors of patients with COVID-19. Objective: Our primary objectives are to describe the clinical characteristics and determine the factors that predict intensive care unit (ICU) admission of patients with COVID-19. Determining these factors using a well-defined population can increase our understanding of the real-world epidemiology of the disease. Methods: We used a combination of classic epidemiological methods, natural language processing (NLP), and machine learning (for predictive modeling) to analyze the electronic health records (EHRs) of patients with COVID-19. We explored the unstructured free text in the EHRs within the Servicio de Salud de Castilla-La Mancha (SESCAM) Health Care Network (Castilla-La Mancha, Spain) from the entire population with available EHRs (1,364,924 patients) from January 1 to March 29, 2020. We extracted related clinical information regarding diagnosis, progression, and outcome for all COVID-19 cases. Results: A total of 10,504 patients with a clinical or polymerase chain reaction?confirmed diagnosis of COVID-19 were identified; 5519 (52.5%) were male, with a mean age of 58.2 years (SD 19.7). Upon admission, the most common symptoms were cough, fever, and dyspnea; however, all three symptoms occurred in fewer than half of the cases. Overall, 6.1% (83/1353) of hospitalized patients required ICU admission. Using a machine-learning, data-driven algorithm, we identified that a combination of age, fever, and tachypnea was the most parsimonious predictor of ICU admission; patients younger than 56 years, without tachypnea, and temperature 39 ºC without respiratory crackles) were not admitted to the ICU. In contrast, patients with COVID-19 aged 40 to 79 years were likely to be admitted to the ICU if they had tachypnea and delayed their visit to the emergency department after being seen in primary care. Conclusions: Our results show that a combination of easily obtainable clinical variables (age, fever, and tachypnea with or without respiratory crackles) predicts whether patients with COVID-19 will require ICU admissio
Impact of the COVID-19 pandemic in mortality due to respiratory diseases: A comparative analysis of 2021 and 2020 vs 2019 in Spain.
Introduction: We previously reported an increase in respiratory mortality in 2020 in Spain after COVID-19. It is unclear if this rise is sustained in the longer-term. We aimed to determine whether respiratory mortality in 2021 in Spain returned to pre-pandemic levels. Material and methods: In an observational, large study using official National Institute of Statistics data, we explored deaths due to respiratory diseases, that is, all causes of death by the standard WHO list of diseases of the respiratory system plus COVID-19, tuberculosis and lung cancer. Using the latest available official data of Spain, we analyzed changes in the mortality pattern in Spain from January 2019 to December 2021. We endorsed STROBE guidance for observational research. Results: There were 98,714 deaths due to respiratory diseases in 2021 in Spain, corresponding to 21.9% of all deaths, becoming second in the ranking of causes of death. Respiratory diseases mortality in Spain has not returned to pre-pandemic levels in 2021, still with an increase of 30.3% (95% CI 30.2-30.4) compared to rates in 2019. All respiratory-specific causes of death decreased in 2021, except for lung cancer, that increased in women and decreased in men compared to 2019 (both p<0.05). In a multivariate analysis some established risk factors for respiratory diseases mortality were confirmed, such as male gender and older age; further, an association with reduced mortality in rural Spain was observed, still with a large geographical variability. Conclusions: The COVID-19 pandemic has had a lasting impact on deaths due to respiratory diseases and certain specific causes of death in 2021, and it has disproportionately affected certain regions
Face Mask Exemptions, Respiratory Patients, and COVID-19 in Spain. Data From the 2021 ITC EUREST-PLUS Spain Survey
Dear Editor, During the initial waves of the COVID-19 pandemic, respiratory patients received confusing messages by several patient associations and the World Health Organization1, 2 to be exempted from wearing face masks. Allegedly, many assumed that difficult breathing through face masks might exacerbate their respiratory condition, producing asthma attacks or chronic obstructive pulmonary disease (COPD) exacerbations. In its December 2020 Interim Guidance on Mask use in the context of COVID-19, WHO cited studies suggesting that masks might have an adverse impact on respiratory disease patients, but they did not provide any guidance about whether respiratory disease patients should or should not wear masks; explicitly, it reads in page 10 of 22 the following paragraph and references
Space-Dependent Probabilities for Oscillations
We analyze oscillations in space in terms of propagating wave
packets with coherent and components. The oscillation probabilities
and depending only on the
distance , are defined through the time integration of a current density
. The definition is such that it coincides with the experimental
setting, thus avoiding some ambiguities and clarifying some controversies that
have been discussed recently.Comment: 11 pages, late
Invariants of Lie Algebras with Fixed Structure of Nilradicals
An algebraic algorithm is developed for computation of invariants
('generalized Casimir operators') of general Lie algebras over the real or
complex number field. Its main tools are the Cartan's method of moving frames
and the knowledge of the group of inner automorphisms of each Lie algebra.
Unlike the first application of the algorithm in [J. Phys. A: Math. Gen., 2006,
V.39, 5749; math-ph/0602046], which deals with low-dimensional Lie algebras,
here the effectiveness of the algorithm is demonstrated by its application to
computation of invariants of solvable Lie algebras of general dimension
restricted only by a required structure of the nilradical.
Specifically, invariants are calculated here for families of real/complex
solvable Lie algebras. These families contain, with only a few exceptions, all
the solvable Lie algebras of specific dimensions, for whom the invariants are
found in the literature.Comment: LaTeX2e, 19 page
Characteristics and prognosis of COVID-19 in patients with COPD
Patients with Chronic Obstructive Pulmonary Disease (COPD) have a higher prevalence
of coronary ischemia and other factors that put them at risk for COVID-19-related complications.
We aimed to explore the impact of COVID-19 in a large population-based sample of patients with
COPD in Castilla-La Mancha, Spain. We analyzed clinical data in electronic health records from
1 January to 10 May 2020 by using Natural Language Processing through the SAVANA Manager®
clinical platform. Out of 31,633 COPD patients, 793 had a diagnosis of COVID-19. The proportion
of patients with COVID-19 in the COPD population (2.51%; 95% CI 2.33–2.68) was significantly
higher than in the general population aged >40 years (1.16%; 95% CI 1.14–1.18); p < 0.001. Compared
with COPD-free individuals, COPD patients with COVID-19 showed significantly poorer disease
prognosis, as evaluated by hospitalizations (31.1% vs. 39.8%: OR 1.57; 95% CI 1.14–1.18) and mortality
(3.4% vs. 9.3%: OR 2.93; 95% CI 2.27–3.79). Patients with COPD and COVID-19 were significantly
older (75 vs. 66 years), predominantly male (83% vs. 17%), smoked more frequently, and had more
comorbidities than their non-COPD counterparts. Pneumonia was the most common diagnosis
among COPD patients hospitalized due to COVID-19 (59%); 19% of patients showed pulmonary
infiltrates suggestive of pneumonia and heart failure. Mortality in COPD patients with COVID-19 was
associated with older age and prevalence of heart failure (p < 0.05). COPD patients with COVID-19
showed higher rates of hospitalization and mortality, mainly associated with pneumonia. This clinical
profile is different from exacerbations caused by other respiratory viruses in the winter seasonGrant COVID-19 UAH 2019/00003/016/001/005 from Alcalá Universit
All solvable extensions of a class of nilpotent Lie algebras of dimension n and degree of nilpotency n-1
We construct all solvable Lie algebras with a specific n-dimensional
nilradical n_(n,2) (of degree of nilpotency (n-1) and with an (n-2)-dimensional
maximal Abelian ideal). We find that for given n such a solvable algebra is
unique up to isomorphisms. Using the method of moving frames we construct a
basis for the Casimir invariants of the nilradical n_(n,2). We also construct a
basis for the generalized Casimir invariants of its solvable extension s_(n+1)
consisting entirely of rational functions of the chosen invariants of the
nilradical.Comment: 19 pages; added references, changes mainly in introduction and
conclusions, typos corrected; submitted to J. Phys. A, version to be
publishe
Bell-inequalities for Pairs from -Resonance Decays
We analyze the premises of recent propositions to test local realism via
Bell-inequalities using neutral kaons from -resonance decays as entangled
EPR-pairs. We pay special attention to the derivation of Bell-inequalities, or
related expressions, for unstable and oscillating kaon `quasi-spin' states and
to the possibility of the actual identification of these states through their
associated decay modes. We discuss an indirect method to extract probabilities
to find these states by combining experimental information with theoretical
input. However, we still find inconsistencies in previous derivations of
Bell-inequalities. We show that the identification of the quasi-spin states via
their associated decay mode does not allow the free choice to perform different
tests on them, a property which is crucial to establish the validity of any
Bell-inequality in the context of local realism. In view of this we propose a
different kind of Bell-inequality in which the free choice or adjustability of
the experimental set-up is guaranteed. We also show that the proposed
inequalities are violated by quantum mechanics.Comment: 22 pages. Late
Three-party entanglement from positronium
The decay of ortho-positronium into three photons produces a physical
realization of a pure state with three-party entanglement. Its quantum
correlations are analyzed using recent results on quantum information theory,
looking for the final state which has the maximal amount of GHZ-like
correlations. This state allows for a statistical dismissal of local realism
stronger than the one obtained using any entangled state of two spin one-half
particles.Comment: REVTEX, 13 pages, 3 figure
Neutrino oscillations from relativistic flavor currents
By resorting to recent results on the relativistic currents for mixed
(flavor) fields, we calculate a space-time dependent neutrino oscillation
formula in Quantum Field Theory. Our formulation provides an alternative to
existing approaches for the derivation of space dependent oscillation formulas
and it also accounts for the corrections due to the non-trivial nature of the
flavor vacuum. By exploring different limits of our formula, we recover already
known results. We study in detail the case of one-dimensional propagation with
gaussian wavepackets both in the relativistic and in the non-relativistic
regions: in the last case, numerical evaluations of our result show significant
deviations from the standard formula.Comment: 16 pages, 4 figures, RevTe
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