A process mining- deep learning approach to predict survival in a cohort of hospitalized COVID-19 patients.

BACKGROUND: Various machine learning and artificial intelligence methods have been used to predict outcomes of hospitalized COVID-19 patients. However, process mining has not yet been used for COVID-19 prediction. We developed a process mining/deep learning approach to predict mortality among COVID-19 patients and updated the prediction in 6-h intervals during the first 72 h after hospital admission. METHODS: The process mining/deep learning model produced temporal information related to the variables and incorporated demographic and clinical data to predict mortality. The mortality prediction was updated in 6-h intervals during the first 72 h after hospital admission. Moreover, the performance of the model was compared with published and self-developed traditional machine learning models that did not use time as a variable. The performance was compared using the Area Under the Receiver Operator Curve (AUROC), accuracy, sensitivity, and specificity. RESULTS: The proposed process mining/deep learning model outperformed the comparison models in almost all time intervals with a robust AUROC above 80% on a dataset that was imbalanced. CONCLUSIONS: Our proposed process mining/deep learning model performed significantly better than commonly used machine learning approaches that ignore time information. Thus, time information should be incorporated in models to predict outcomes more accurately.

Initial survival of the Isis® total trapeziometacarpal prosthesis with conical trunk threaded cups. / Supervivencia inicial de la prótesis total trapeciometacarpiana de cúpula roscada Isis®.

INTRODUCTION: The treatment of trapeziometacarpal osteoarthritis through the implantation of total trapeziometacarpal prostheses is in continuous expansion. The Isis® prosthesis is a trunk-conical threaded anchorage prosthesis. Our objective was to assess the functional results and survival of this implant for at least one year of follow-up. MATERIAL AND METHOD: Prospective study on 53 Isis® prosthesis, implanted from april 2014 to january 2019. The Van Cappelle functional test, pain, strength, mobility, return to previous activity, radiological variables and placement of the trapezial component were evaluated. The surgical technique was performed with a guide wirefocused on the trapezius and control of the scopia. Observed complications were recorded and statistical analysis was performed. RESULTS: Fifty-one implants (49 patients) were reviewed. Mean follow-up was 2.1 years (1-5.7). Van Cappelle's test, pain, mobility, and grip and clamp strength improved significantly, as did the distance between the metacarpal head and the trapezius base; 96% of the patients returned in less than 6 months to their activities. Minor complications, 3 De Quervain's tendinopathy and 2 intra-operative metacarpal and 2 trapezium fractures were recorded, and one carpal tunnel syndrome. There was no dislocation, mobilization, or implant infection. CONCLUSIONS: The functional results of the Isis® prosthesis are excellent in the short term, far exceeding the first year of 100% of survival. The complications that arose were minor and few. The anchorage and placement of the trapezial component guided by scopia seem to be crucial for the good result.

Spontaneous coronary artery dissection.

Spontaneous coronary artery dissection is an underdiagnosed entity. It has been recognized as an important cause of acute coronary syndrome and sudden death, particularly among young women and individuals with few conventional atherosclerotic risk factors. This document provides an exhaustive review of the pathophysiology and etiology of this disease. In addition, we describe the main clinical characteristics of these patients, the diagnostic tests that must be performed, and the most appropriate treatment.

Disección coronaria espontánea / Spontaneous coronary artery dissection

La disección coronaria espontánea es una entidad infradiagnosticada, que ha resultado ser una causa importante de síndrome coronario agudo y muerte súbita, en particular, en mujeres jóvenes y personas con pocos factores de riesgo cardiovascular convencionales. Este documento ofrece una revisión actualizada sobre la fisiopatología y etiología de esta enfermedad; se describen las principales características clínicas de estos pacientes, así como las pruebas diagnósticas que se deben realizar y el tratamiento más adecuado (AU)

Spontaneous coronary artery dissection is an underdiagnosed entity. It has been recognized as an important cause of acute coronary syndrome and sudden death, particularly among young women and individuals with few conventional atherosclerotic risk factors. This document provides an exhaustive review of the pathophysiology and etiology of this disease. In addition, we describe the main clinical characteristics of these patients, the diagnostic tests that must be performed, and the most appropriate treatment (AU)

Spontaneous coronary artery dissection. / Disección coronaria espontánea.

Spontaneous coronary artery dissection is an underdiagnosed entity. It has been recognized as an important cause of acute coronary syndrome and sudden death, particularly among young women and individuals with few conventional atherosclerotic risk factors. This document provides an exhaustive review of the pathophysiology and etiology of this disease. In addition, we describe the main clinical characteristics of these patients, the diagnostic tests that must be performed, and the most appropriate treatment.

Breakdown of the coherence effects and Fermi liquid behavior in YbAl3 nanoparticles.

A change in the Kondo lattice behavior of bulk YbAl3 has been observed when the alloy is shaped into nanoparticles (≈12 nm). Measurements of the electrical resistivity show inhibited coherence effects and deviation from the standard Fermi liquid behavior (T 2-dependence). These results are interpreted as being due to the effect of the disruption of the periodicity of the array of Kondo ions provoked by the size reduction process. Additionally, the ensemble of randomly placed nanoparticles also triggers an extra source of electronic scattering at very low temperatures (≈15 K) due to quantum interference effects.

Effect of 3basic life support training programs in future primary school teachers. A quasi-experimental design. / Efecto de 3métodos de enseñanza en soporte vital básico en futuros maestros de Educación Primaria. Un diseño cuasiexperimental.

AIM: To evaluate the learning of basic life support (BLS) measures on the part of laypersons after 3different teaching programs. DESIGN: A quasi-experimental before-after study involving a non-probabilistic sample without a control group was carried out. SCOPE: Primary school teacher students from the University of Santiago (Spain). PARTICIPANTS: A total of 124 students (68.8% women and 31.2% men) aged 20-39 years (M=22.23; SD=3.79), with no previous knowledge of BLS, were studied. INTERVENTIONS: Three teaching programs were used: a traditional course, an audio-visual approach and feedback devices. MAIN VARIABLES OF INTEREST: Chest compressions as sole cardiopulmonary resuscitation skill evaluation: average compression depth, compression rate, chest recoil percentage and percentage of correct compressions. Automated external defibrillator: time needed to apply a shock before and after the course. RESULTS: There were significant differences in the results obtained after 2minutes of chest compressions, depending on the training program received, with feedback devices having a clear advantage referred to average compression depth (p<0.001), compression rate (p<0.001), chest recoil percentage (p<0.001) and percentage of correct compressions (p<0.001). Regarding automated external defibrillator, statistically significant differences were found in Tafter (p=0.025). CONCLUSIONS: The teaching course using feedback devices obtained the best results in terms of the quality of chest compressions, followed by the traditional course and audio-visual approach. These favorable results were present in both men and women. All 3teaching methods reached the goal of reducing defibrillation time.

Chemical characterization of diesel and hydrotreated vegetable oil (HVO) soot after reactive gas probing using diffuse reflectance FTIR spectroscopy (DRIFTS).

A chemical characterization of diesel and hydrotreated vegetable oil (HVO) soot has been developed using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) before and after the reaction with different probe gases. Samples were generated under combustion conditions corresponding to an urban operation mode of a diesel engine and were reacted with probe gas-phase molecules in a Knudsen flow reactor. Specifically, NH2OH, O3 and NO2 were used as reactants (probes) and selected according to their reactivities towards specific functional groups on the sample surface. Samples of previously ground soot were diluted with KBr and were introduced in a DRIFTS accessory. A comparison between unreacted and reacted soot samples was made in order to establish chemical changes on the soot surface upon reaction. It was concluded that the interface of diesel and HVO soot before reaction mainly consists polycyclic aromatic hydrocarbons, nitro and carbonyl compounds, as well as ether functionalities. The main difference between both soot samples was observed in the band of the C=O groups that in diesel soot was observed at 1719 cm-1 but not in HVO soot. After reaction with probe gases, it was found that nitro compounds remain on the soot surface, that the degree of unsaturation decreases for reacted samples, and that new spectral bands such as hydroxyl groups are observed.

Molecular Characterization of the Gas-Particle Interface of Soot Sampled from a Diesel Engine Using a Titration Method.

Surface functional groups of two different types of combustion aerosols, a conventional diesel (EN 590) and a hydrotreated vegetable oil (HVO) soot, have been investigated using heterogeneous chemistry (i.e., gas-particle surface reactions). A commercial sample of amorphous carbon (Printex XE2-B) was analyzed as a reference substrate. A Knudsen flow reactor was used to carry out the experiments under molecular flow conditions. The selected gases for the titration experiments were: N(CH3)3 for the identification of acidic sites, NH2OH for the presence of carbonyl groups, CF3COOH and HCl for basic sites of different strength, and O3 and NO2 for reducing groups. Reactivity with N(CH3)3 indicates a lower density of acidic functionalities for Printex XE2-B in relation to diesel and HVO soot. Results for NH2OH experiments indicates that commercial amorphous carbon exhibits a lower abundance of available carbonyl groups at the interface compared to the results from diesel and HVO soot, the latter being the one with the largest abundance of carbonyl functions. Reactions with acids indicate the presence of weak basic oxides on the particle surface that preferentially interact with the strong acid CF3COOH. Finally, reactions with O3 and NO2 reveal that diesel and especially HVO have a significantly higher reactivity with both oxidizers compared to that of Printex XE2-B because they have more reducing sites by roughly a factor of 10 and 30, respectively. The kinetics of titration reactions have also been investigated.

Magnetic phase diagram of superantiferromagnetic TbCu2 nanoparticles.

The structural state and static and dynamic magnetic properties of TbCu2 nanoparticles are reported to be produced by mechanical milling under inert atmosphere. The randomly dispersed nanoparticles as detected by TEM retain the bulk symmetry with an orthorhombic Imma lattice and Tb and Cu in the 4e and 8h positions, respectively. Rietveld refinements confirm that the milling produces a controlled reduction of particle sizes reaching ≃6 nm and an increase of the microstrain up to ≃0.6%. The electrical resistivity indicates a metallic behavior and the presence of a magnetic contribution to the electronic scattering which decreases with milling times. The dc-susceptibility shows a reduction of the Néel transition (from 49 K to 43 K) and a progressive increase of a peak (from 9 K to 15 K) in the zero-field-cooled magnetization with size reduction. The exchange anisotropy is very weak (a bias field of ≃30 Oe) and is due to the presence of a disordered (thin) shell coupled to the antiferromagnetic core. The dynamic susceptibility evidences a critical slowing down in the spin-disordered state for the lowest temperature peak associated with a spin glass-like freezing with a tendency of zv and ß exponents to increase when the size becomes 6 nm (zv ≃ 6.6 and ß ≃ 0.85). A Rietveld analysis of the neutron diffraction patterns 1.8 ≤ T ≤ 60 K, including the magnetic structure determination, reveals that there is a reduction of the expected moment (≃80%), which must be connected to the presence of the disordered particle shell. The core magnetic structure retains the bulk antiferromagnetic arrangement. The overall interpretation is based on a superantiferromagnetic behavior which at low temperatures coexists with a canting of surface moments and a mismatch of the antiferromagnetic sublattices of the nanoparticles. We propose a novel magnetic phase diagram where changes are provoked by a combination of the decrease of size and the increase of microstrain.

Interplay between microstructure and magnetism in NiO nanoparticles: breakdown of the antiferromagnetic order.

The possibility of tuning the magnetic behaviour of nanostructured 3d transition metal oxides has opened up the path for extensive research activity in the nanoscale world. In this work we report on how the antiferromagnetism of a bulk material can be broken when reducing its size under a given threshold. We combined X-ray diffraction, high-resolution transmission electron microscopy, extended X-ray absorption fine structure and magnetic measurements in order to describe the influence of the microstructure and morphology on the magnetic behaviour of NiO nanoparticles (NPs) with sizes ranging from 2.5 to 9 nm. The present findings reveal that size effects induce surface spin frustration which competes with the expected antiferromagnetic (AFM) order, typical of bulk NiO, giving rise to a threshold size for the AFM phase to nucleate. Ni(2+) magnetic moments in 2.5 nm NPs seem to be in a spin glass (SG) state, whereas larger NPs are formed by an uncompensated AFM core with a net magnetic moment surrounded by a SG shell. The coupling at the core-shell interface leads to an exchange bias effect manifested at low temperature as horizontal shifts of the hysteresis loop (~1 kOe) and a coercivity enhancement (~0.2 kOe).

Sulphur tracer experiments in laboratory animals using 34S-labelled yeast.

We have evaluated the use of (34)S-labelled yeast to perform sulphur metabolic tracer experiments in laboratory animals. The proof of principle work included the selection of the culture conditions for the preparation of sulphur labelled yeast, the study of the suitability of this labelled yeast as sulphur source for tracer studies using in vitro gastrointestinal digestion and the administration of the (34)S-labelled yeast to laboratory animals to follow the fate and distribution of (34)S in the organism. For in vitro gastrointestinal digestion, the combination of sodium dodecyl sulphate-polyacrylamide gel electrophoresis and high-performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC-ICP-MS) showed that labelled methionine, cysteine and other low molecular weight sulphur-containing biomolecules were the major components in the digested extracts of the labelled yeast. Next, in vivo kinetic experiments were performed in healthy Wistar rats after the oral administration of (34)S-labelled yeast. The isotopic composition of total sulphur in tissues, urine and faeces was measured by double-focusing inductively coupled plasma mass spectrometry after microwave digestion. It was observed that measurable isotopic enrichments were detected in all samples. Finally, initial investigations on sulphur isotopic composition of serum and urine samples by HPLC-ICP-MS have been carried out. For serum samples, no conclusive data were obtained. Interestingly, chromatographic analysis of urine samples showed differential isotope enrichment for several sulphur-containing biomolecules.

Magnetic properties of TbAl2 nanometric alloys.

The magnetic properties of nanometric TbAI2 alloys have been investigated. The Curie temperature (T(c)) of these nanometric alloys is strongly size dependent and decreases from 103 K for the bulk alloy down to 98 K for the 14 nm alloy, as the particle volume is reduced. This reduction of T(c) has been explained by a finite-size scaling law of type [T(c)(D) -T(c)(infinity)]/T(c)(infinity) = -(D/D0)-(1/vp), with v = 0.7 and D0 = 2.2a (a, the lattice parameter), in agreement with the three-dimensional Heisenberg model. The size dependence of the coercivity has also been established. An increase of the coercivity from 0.08 kOe (bulk) to 1 kOe for 10 h milled alloy, indicates the crossover from multidomain to single domain behavior around 85 nm, as expected from the estimate of the critical size of monodomain particles. The field dependence of the magnetization indicates a faster thermal reduction of the magnetization of the nanosized alloys (17% in 300 h milled alloy with mean particle size of 14 nm) related to the bulk (3%), in the temperature range between 5 K and 30 K. The results can be explained as a direct consequence of the competing effects of the surface and the purely finite-size effects, in an ensemble of nanometric particles suffering interactions.

Spin-glass freezing in a Ni-vermiculite intercalation compound.

We report on the magnetic properties of a Ni(2+)-vermiculite intercalation compound from Santa Olalla, Huelva (Spain). This modified vermiculite was studied by means of DC and AC magnetic measurements. The existence of two maxima in magnetic susceptibility below 10 K was interpreted in terms of the Cole-Cole formalism as being due to spin-glass freezing in this material. The temperature, frequency and external magnetic field dependences of these anomalies located at temperatures around 2-3 K and 8-10 K in the imaginary part of the magnetic susceptibility, χ″, seem to suggest the existence of spin-relaxation phenomena between the magnetic moments of the Ni(2+) ions. A dynamic study of the relaxation processes associated with these phenomena considering the Cole-Cole formalism allows us to interpret the anomaly found at 2-3 K according to a law of activated dynamics, obtaining values for the critical exponent, ψν < 1, characteristic of a d = 2 spin-glass-like system, while the maximum observed in χ″ at 8-10 K can be described by means of a law of standard dynamics with a value of the exponent z of around 5, representative of a d = 3 spin-glass-like system.

Transformation behavior of Ni-Mn-Ga in the low-temperature limit.

The magnetic, magnetocaloric and thermal characteristics have been studied in a Ni(50.3)Mn(20.8)Ga(27.6)V(1.3) ferromagnetic shape memory alloy (FSMA) transforming martensitically at around 40 K. The alloy shows first a transformation from austenite to an intermediate phase and then a partial transformation to an orthorhombic martensite, all the phases being ferromagnetically ordered. The thermomagnetization dependences enabled observation of the magnetocaloric effect in the vicinity of the martensitic transformation (MT). The Debye temperature and the density of states at the Fermi level are equal to θ(D) = (276 ± 4) K and 1.3 states/atom eV , respectively, and scarcely dependent on the magnetic field. The MT exhibited by Ni-Mn-Ga FSMAs at very low temperatures is distinctive in the sense that it is accompanied by a hardly detectable entropy change as a sign of a small driving force. The enhanced stability of the cubic phase and the low driving force of the MT stem from the reduced density of states near the Fermi level.

Technical advance: Surface plasmon resonance-based analysis of CXCL12 binding using immobilized lentiviral particles.

Use of SPR-based biosensors is an established method for measuring molecular interactions. Their application to the study of GPCRs is nonetheless limited to detergent-solubilized receptors that can then be reconstituted into a lipid environment. Using the chemokine receptor CXCR4 and its specific ligand CXCL12, we outline here a highly reproducible biosensor method based on receptor presentation on the surface of lentiviral particles; the approach is simple and does not require the use of antibodies to achieve correct receptor orientation on the sensorchip surface. We measured the kinetic parameters of CXCR4/CXCL12 binding in a single step and in real time and evaluated the effect of GAG presentation of chemokines on this interaction. The data indicate that at low concentrations, soluble heparin modulates CXCR4/CXCL12 interaction and at high concentrations, abrogates binding. These observations suggest that in addition to their known role in modulating local chemokine availability, GAG affect the receptor/ligand interaction, although their influence on affinity parameters is very limited. The method will also be useful for quantifying these biomarkers in biological fluids and for the development of high-throughput screening for their antagonists.

Prevalence of donor-transmitted coronary artery disease and its influence on heart transplant outcomes.

BACKGROUND: It is uncertain whether donor-transmitted coronary artery disease (DTCAD) affects heart transplant (HT) recipients. METHODS: This retrospective analysis includes records of all patients who underwent a HT at our center over an 8-year period, who survived for at least 1 month, and who were examined by coronary angiography within 2 months post-HT. We distinguished angiographically from keep ultrasonography (IVUS) detected DTCAD. Major adverse cardiovascular events (MACE) comprised death, myocardial infarction, unstable angina, coronary revascularization, and admission because of heart failure not due to an acute rejection episode. RESULTS: Among the 171 patients of mean age 53±13 years and including 83% men, 65 (38%) were evaluated by IVUS. Donors were aged 40±14 years (range=14-73). Angiographic DTCAD affected seven patients (4.1%), and IVUS-detected DTCAD, 35 (53.8% of those examined by IVUS). DTCAD donors were older than non-DTCAD donors, by an average of 13 years (P=.001) for angiographic DTCAD and 18 years (P<.0001) for IVUS-detected DTCAD. Two patients underwent percutaneous revascularization upon detection of angiographic DTCAD. The angiographic- and IVUS-detected DTCAD groups did not differ significantly from the corresponding non-DTCAD groups as regards MACE incidence during 54±41 and 38±20 months follow-up, respectively. Cox regression analysis with adjustment for relevant confounders confirmed that IVUS-detected DTCAD was not a predictor of MACE (hazard ratio 1.2, 95% confidence interval 0.2-8.1). CONCLUSIONS: Among HT patients surviving≥1 month, angiographic- and IVUS-detected DTCAD showed prevalences of <10% and >50%, respectively. Neither detection method was associated with a greater long-term incidence of MACE.

Efficacy and tolerance of different types of prophylaxis for prevention of early aspergillosis after heart transplantation.

BACKGROUND: The incidence of aspergillosis (ASP) after heart transplantation (HTx) is low (<4%-5%), but the mortality is high (>78%). AIM: To determine the incidence of ASP in the first 3 months post-HTx according to the type of prophylaxis and assess the tolerance to these regimens. METHODS: This retrospective study of 571 adult HTx patients engrafted from 1991 to December 2009 included 83% males with an overall group age of 54.9±11 years. Three types of prophylaxis were compared: group A was no prophylaxis (n=99; 1991-1994); group B, itraconazole for 3 months (n=352; 1995-November 2004); and group C, inhaled amphotericin for 3 months (n=120; December 2004-2009). The dependent variables were the presence and severity or tracheobronchitis and invasive/disseminated disease as well as, prognosis of Aspergillus infection and tolerance to the regimen. RESULTS: The incidences of aspergillosis were 5% in group A (n=5); 1.4% in group B (n=5); and 0% in group C. Significant differences were observed between groups A versus B (P=.030) and between groups A versus C (P=.013), but there were no differences between groups B versus C. In terms of severity, there were no significant differences among the five cases of tracheobronchitis (20% group A/80% group B), five of invasive/disseminated disease (80% group A/20% group B). There were two deaths (20%) from invasive/disseminated ASP at 0.67 months after diagnosis. The mean time from HTx to ASP was 0.98±0.40 months. There were no adverse effects associated with itraconazole, but they occurred in 3/120 patients (2.5%) treated with inhaled amphotericin, all of whom were on mechanical ventilation, developing respiratory failure requiring amphotericin withdrawal. CONCLUSIONS: Prophylaxis with itraconazole or inhaled amphotericin was effective for the prevention and severity of pulmonary ASP in the first 3 months post-HTx. Although the incidence of early ASP was low in our series, the 20% mortality rate justified the use of preventive measures. Tolerance to both prophylactic treatments was good.

Phonon softening on the specific heat of nanocrystalline metals.

Specific heat enhancement in several common nanocrystalline metals is established by comparison with their bulk counterparts. Measurements were carried out in Fe, Cu, Ni and binary alloy LaAl(2). The excess specific heat is evidenced as a low temperature peak below 65 K and a high temperature slope above 150 K. The experimental data are in good agreement with a model which considers contributions from the grain boundary and core atoms in the nanoparticles. This model is supported by Raman spectroscopy measurements, showing a softening of the frequency phonon modes associated with a size reduction and increase of the atomic disorder.

CdEr2Se4: a new erbium spin ice system in a spinel structure.

Here we present a detailed study of the spinel CdEr2Se4 and show it to be a new instance of spin ice, the first one in an erbium material and the first one in a spinel. Definitive experimental evidence comes from the temperature dependence of the magnetic entropy, which shows an excellent agreement with the predicted behavior for a spin ice state. Crystal field calculations demonstrate that the change in the local environment from that of the titanates completely alters the rare-earth anisotropy giving rise, in the case of Er3+, to the required Ising anisotropy, when Er2Ti2O7 behaves as an XY antiferromagnet. This finding opens up the possibility of new exotic ground states within the CdR2Se4 and CdR2Se4 families.