Pseudo-Fubini Real-Entire Functions on the Plane Bernal-González, Luis; Calderón-Moreno, María del Carmen; Jung, Andreas
Mediterranean journal of mathematics,
10/2022, Letnik:
19, Številka:
5
Journal Article
Recenzirano
Odprti dostop
In this note, it is proved the existence of a
c
-dimensional vector space of real-entire functions all of whose nonzero members are non-integrable in the sense of Lebesgue but yet their two iterated ...integrals exist as real numbers and coincide. Moreover, it is shown that this vector space can be chosen to be dense in the space of all real
C
∞
-functions on the plane endowed with the topology of uniform convergence on compacta for all derivatives of all orders. If the condition of being entire is dropped, then a closed infinite dimensional subspace satisfying the same properties can be obtained.
Undominated Sequences of Integrable Functions Bernal-González, Luis; del Carmen Calderón-Moreno, María; Murillo-Arcila, Marina ...
Mediterranean journal of mathematics,
12/2020, Letnik:
17, Številka:
6
Journal Article
Recenzirano
Odprti dostop
In this paper, we investigate to what extent the conclusion of the Lebesgue dominated convergence theorem holds if the assumption of dominance is dropped. Specifically, we study both topological and ...algebraic genericity of the family of all null sequences of functions that, being continuous on a locally compact space and integrable with respect to a given Borel measure in it, are not controlled by an integrable function.
It is shown in this short note the existence, for each nonzero member of the ideal of D-multiples of convolution operators acting on the space of entire functions, of a scalar multiple of it ...supporting a hypercyclic algebra.
In this note, the linear structure of the family He(G) of holomorphic functions in a domain G of a complex Banach space that are not holomorphically continuable beyond the boundary of G is analyzed. ...More particularly, we prove that He(G) contains, except for zero, a closed (and a dense) vector space having maximal dimension, as well as a maximally generated free algebra. The results obtained complete a number of previous ones by several authors.
Abstract
Background
Advanced age is a well-known risk factor for poor prognosis in COVID-19. However, few studies have specifically focused on very old inpatients with COVID-19. This study aims to ...describe the clinical characteristics of very old inpatients with COVID-19 and identify risk factors for in-hospital mortality at admission.
Methods
We conducted a nationwide, multicenter, retrospective, observational study in patients ≥ 80 years hospitalized with COVID-19 in 150 Spanish hospitals (SEMI-COVID-19) Registry (March 1–May 29, 2020). The primary outcome was in-hospital mortality. A uni- and multivariate logistic regression was performed to assess predictors of mortality at admission.
Results
A total of 2772 consecutive patients (49.4% men, median age 86.3 years) were analyzed. Rates of atherosclerotic cardiovascular disease, diabetes mellitus, dementia, and Barthel Index < 60 were 30.8%, 25.6%, 30.5%, and 21.0%, respectively. The overall case-fatality rate was 46.9% (n: 1301) and increased with age (80–84 years: 41.6%; 85–90 years: 47.3%; 90–94 years: 52.7%; ≥95 years: 54.2%). After analysis, male sex and moderate-to-severe dependence were independently associated with in-hospital mortality; comorbidities were not predictive. At admission, independent risk factors for death were: oxygen saturation < 90%; temperature ≥ 37.8°C; quick sequential organ failure assessment (qSOFA) score ≥ 2; and unilateral–bilateral infiltrates on chest x-rays. Some analytical findings were independent risk factors for death, including estimated glomerular filtration rate < 45 mL/min/1.73 m2; lactate dehydrogenase ≥ 500 U/L; C-reactive protein ≥ 80 mg/L; neutrophils ≥ 7.5 × 103/μL; lymphocytes < 0.8 × 103/μL; and monocytes < 0.5 × 103/μL.
Conclusions
This first large, multicenter cohort of very old inpatients with COVID-19 shows that age, male sex, and poor preadmission functional status—not comorbidities—are independently associated with in-hospital mortality. Severe COVID-19 at admission is related to poor prognosis.
Anti M-Weierstrass function sequences Calderón-Moreno, María del Carmen; Gerlach-Mena, Pablo José; Prado-Bassas, José Antonio
Journal of mathematical analysis and applications,
11/2020, Letnik:
491, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Large algebraic structures are found inside the space of sequences of continuous functions on a compact interval having the property that, the series defined by each sequence converges absolutely and ...uniformly on the interval but the series of the upper bounds diverges. So showing that there exist many examples satisfying the conclusion but not the hypothesis of the Weierstrass M-test.
In this note, a vector space of real-analytic functions on the plane is explicitly constructed such that all its nonzero functions are non-integrable but yet their two iterated integrals exist as ...real numbers and coincide. Moreover, it is shown that this vector space is dense in the space of all real continuous functions on the plane endowed with the compact-open topology.
Anti-L’Hôpital Differentiable Functions Bernal-González, Luis; Calderón-Moreno, María del Carmen
Mediterranean journal of mathematics,
02/2017, Letnik:
14, Številka:
1
Journal Article
Recenzirano
Large algebraic structures are found inside the family of those real differentiable functions
f
on the real line having the property that, for a prescribed subset
Z
, the continuity of
f
′
fails at ...the points of
Z
, so showing that, even in the easiest case, the L’Hôpital rule should be used carefully.
midregional proadrenomedullin (MR-proADM) is a prognostic biomarker in patients with community-acquired pneumonia (CAP). We sought to confirm whether MR-proADM added to Pneumonia Severity Index (PSI) ...improves the potential prognostic value of PSI alone, and tested to what extent this combination could be useful in predicting poor outcome of patients with CAP in an Emergency Department (ED).
Consecutive patients diagnosed with CAP were enrolled in this prospective, single-centre, observational study. We analyzed the ability of MR-proADM added to PSI to predict poor outcome using receiver operating characteristic (ROC) curves, logistic regression and risk reclassification and comparing it with the ability of PSI alone. The primary outcome was "poor outcome", defined as the incidence of an adverse event (ICU admission, hospital readmission, or mortality at 30 days after CAP diagnosis).
226 patients were included; 33 patients (14.6%) reached primary outcome. To predict primary outcome the highest area under curve (AUC) was found for PSI (0.74 0.64-0.85), which was not significantly higher than for MR-proADM (AUC 0.72 0.63-0.81, p > 0.05). The combination of PSI and MR-proADM failed to improve the predictive potential of PSI alone (AUC 0.75 0.65-0.85, p=0.56). Ten patients were appropriately reclassified when the combined PSI and MR-proADM model was used as compared with the model of PSI alone. Net reclassification improvement (NRI) index was statistically significant (7.69%, p = 0.03) with an improvement percentage of 3.03% (p = 0.32) for adverse event, and 4.66% (P = 0.02) for no adverse event.
MR-proADM in combination with PSI may be helpful in individual risk stratification for short-term poor outcome of CAP patients, allowing a better reclassification of patients compared with PSI alone.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Display omitted
•A new nitrite sensing platform based on SnO2 was designed, fabricated and tested.•SnO2 coatings exhibited good electrocatalytic properties toward nitrite oxidation.•Nitrite detection ...was proved in real samples with satisfactory recovery.•The sensing platform demonstrated good sensitivity, selectivity and stability.
Our work aims to develop a novel electrochemical sensing platform based on SnO2/Pt/Ti/SiO2/Si for selective nitrite detection. SnO2 coatings were prepared by classic sol-gel and microwave assisted sol-gel technique. In order to establish the best preparation conditions and electrocatalytic properties of the SnO2/Pt/Ti/SiO2/Si a complex investigation using X-ray diffraction (XRD), atomic force (AFM), scanning electron microscopy (SEM) as well as electrochemical methods like cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), differential pulse voltammetry (DPV) and chronoamperometry (CA) was accomplished. The proposed platform demonstrated high sensitivity, selectivity and good stability for nitrite detection being a proper tool in nitrite sensing in real samples. A linear response was obtained on concentration range between 10 and 400 μM with the limits of detection and quantification of 1.7 (± 0.1) μM and 5.6 (± 0.2) μM, respectively.
PDF
