Interplay of self, epiphany, and positive actions in shaping individual careers.

In this work, we model an individual social career by a finite-size trajectory along a hexagonal lattice moving only forward. At each bifurcation, the individual makes a free-will choice to follow one or the other branch within an uncertain outcome. Considering that those choices are determined by an individual self built from endogenous characteristics, we assume they are random following a binomial distribution. As a result, the individual ascends or descends on the social scale via random progress through the series of bifurcations made at the encountered junctions. The related stochastic process is found to be diffusive. For different selves coming from different points on the social scale, progress does overlap. In addition, we include the possibility of continuous transition across the lattice caused external influences as an epiphany. The occurrence of a quantum leap resulting from an affirmative action opportunity is also included. We also treat the case of a social group being acted by a collective epiphany as with education. The results highlight the key effect of epiphanies and quantum leaps to promote upward mobility across social classes.

Mortality predictors in patients with COVID-19 pneumonia: a machine learning approach using eXtreme Gradient Boosting model.

Recently, global health has seen an increase in demand for assistance as a result of the COVID-19 pandemic. This has prompted many researchers to conduct different studies looking for variables that are associated with increased clinical risk, and find effective and safe treatments. Many of these studies have been limited by presenting small samples and a large data set. Using machine learning (ML) techniques we can detect parameters that help us to improve clinical diagnosis, since they are a system for the detection, prediction and treatment of complex data. ML techniques can be valuable for the study of COVID-19, especially because they can uncover complex patterns in large data sets. This retrospective study of 150 hospitalized adult COVID-19 patients, of which we established two groups, those who died were called Case group (n = 53) while the survivors were Control group (n = 98). For analysis, a supervised learning algorithm eXtreme Gradient Boosting (XGBoost) has been used due to its good response compared to other methods because it is highly efficient, flexible and portable. In this study, the response to different treatments has been evaluated and has made it possible to accurately predict which patients have higher mortality using artificial intelligence, obtaining better results compared to other ML methods.

Determination of the direct bandgap value in In4Se3thin films.

The value and the nature of the bandgap of In4Se3are still not well defined, with a large spread of the experimental data between 0.42 and 1.68 eV and an uncertain nature, predicted to be indirect byab initioband structure calculations. Here we report on the optical transmission and photoluminescence (PL) performed in In4Se3thin films grown by coevaporation on (0001)-oriented sapphire wafers. The quality of the polycrystalline layers allows the first detection of the excitonic-like transition in the optical absorption of this compound at low temperature. The PL detected under weak laser excitation shows a bound exciton emission at 0.75 eV. Strong laser irradiation reveals a quadratic dependence of the PL intensity on the optical excitation, which demonstrates a stimulated emission at 0.79 eV in relation with an exciton-exciton scattering process. On the basis of a reasonable estimate of the exciton energy, equal to10-15meV, we evaluate the direct bandgap of In4Se3to0.82±0.01eV at low temperature.

A data-driven model for COVID-19 pandemic - Evolution of the attack rate and prognosis for Brazil.

We introduce a compartmental model SEIAHRV (Susceptible, Exposed, Infected, Asymptomatic, Hospitalized, Recovered, Vaccinated) with age structure for the spread of the SARAS-CoV virus. In order to model current different vaccines we use compartments for individuals vaccinated with one and two doses without vaccine failure and a compartment for vaccinated individual with vaccine failure. The model allows to consider any number of different vaccines with different efficacies and delays between doses. Contacts among age groups are modeled by a contact matrix and the contagion matrix is obtained from a probability of contagion p c per contact. The model uses known epidemiological parameters and the time dependent probability p c is obtained by fitting the model output to the series of deaths in each locality, and reflects non-pharmaceutical interventions. As a benchmark the output of the model is compared to two good quality serological surveys, and applied to study the evolution of the COVID-19 pandemic in the main Brazilian cities with a total population of more than one million. We also discuss with some detail the case of the city of Manaus which raised special attention due to a previous report of We also estimate the attack rate, the total proportion of cases (symptomatic and asymptomatic) with respect to the total population, for all Brazilian states since the beginning of the COVID-19 pandemic. We argue that the model present here is relevant to assessing present policies not only in Brazil but also in any place where good serological surveys are not available.

Non-Arrhenius behavior and fragile-to-strong transition of glass-forming liquids.

Characterization of the non-Arrhenius behavior of glass-forming liquids is a broad avenue for research toward the understanding of the formation mechanisms of noncrystalline materials. In this context, this paper explores the main properties of the viscosity of glass-forming systems, considering super-Arrhenius diffusive processes. We establish the viscous activation energy as a function of the temperature, measure the degree of fragility of the system, and characterize the fragile-to-strong transition through the standard Angell's plot. Our results show that the non-Arrhenius behavior observed in fragile liquids can be understood through the non-Markovian dynamics that characterize the diffusive processes of these systems. Moreover, the fragile-to-strong transition corresponds to a change in the spatiotemporal range of correlations during the glass transition process.

Characterization of the non-Arrhenius behavior of supercooled liquids by modeling nonadditive stochastic systems.

The characterization of the formation mechanisms of amorphous solids is a large avenue for research, since understanding its non-Arrhenius behavior is challenging to overcome. In this context, we present one path toward modeling the diffusive processes in supercooled liquids near glass transition through a class of nonhomogeneous continuity equations, providing a consistent theoretical basis for the physical interpretation of its non-Arrhenius behavior. More precisely, we obtain the generalized drag and diffusion coefficients that allow us to model a wide range of non-Arrhenius processes. This provides a reliable measurement of the degree of fragility of the system and an estimation of the fragile-to-strong transition in glass-forming liquids, as well as a generalized Stokes-Einstein equation, leading to a better understanding of the classical and quantum effects on the dynamics of nonadditive stochastic systems.

InSe as a case between 3D and 2D layered crystals for excitons.

InSe is a promising material in many aspects where the role of excitons is decisive. Here we report the sequential appearance in its luminescence of the exciton, the biexciton, and the P-band of the exciton-exciton scattering while the excitation power increases. The strict energy and momentum conservation rules of the P-band are used to reexamine the exciton binding energy. The new value ≥20 meV is markedly higher than the currently accepted one (14 meV), being however well consistent with the robustness of the excitons up to room temperature. A peak controlled by the Sommerfeld factor is found near the bandgap (~1.36 eV). Our findings supported by theoretical calculations taking into account the anisotropic material parameters question the pure three-dimensional character of the exciton in InSe, assumed up to now. The refined character and parameters of the exciton are of paramount importance for the successful application of InSe in nanophotonics.

Rapid screening for lipid storage disorders using biochemical markers. Expert center data and review of the literature.

BACKGROUND: In patients suspected of a lipid storage disorder (sphingolipidoses, lipidoses), confirmation of the diagnosis relies predominantly on the measurement of specific enzymatic activities and genetic studies. New UPLC-MS/MS methods have been developed to measure lysosphingolipids and oxysterols, which, combined with chitotriosidase activity may represent a rapid first tier screening for lipid storage disorders. MATERIAL AND METHODS: A lysosphingolipid panel consisting of lysoglobotriaosylceramide (LysoGb3), lysohexosylceramide (LysoHexCer: both lysoglucosylceramide and lysogalactosylceramide), lysosphingomyelin (LysoSM) and its carboxylated analogue lysosphingomyelin-509 (LysoSM-509) was measured in control subjects and plasma samples of predominantly untreated patients affected with lipid storage disorders (n=74). In addition, the oxysterols cholestane-3ß,5α,6ß-triol and 7-ketocholesterol were measured in a subset of these patients (n=36) as well as chitotriosidase activity (n=43). A systematic review of the literature was performed to assess the usefulness of these biochemical markers. RESULTS: Specific elevations of metabolites, i.e. without overlap between controls and other lipid storage disorders, were found for several lysosomal storage diseases: increased LysoSM levels in acid sphingomyelinase deficiency (Niemann-Pick disease type A/B), LysoGb3 levels in males with classical phenotype Fabry disease and LysoHexCer (i.e. lysoglucosylceramide/lysogalactosylceramide) in Gaucher and Krabbe diseases. While elevated levels of LysoSM-509 and cholestane-3ß,5α,6ß-triol did not discriminate between Niemann Pick disease type C and acid sphingomyelinase deficiency, LysoSM-509/LysoSM ratio was specifically elevated in Niemann-Pick disease type C. In Gaucher disease type I, mild increases in several lysosphingolipids were found including LysoGb3 with levels in the range of non-classical Fabry males and females. Chitotriosidase showed specific elevations in symptomatic Gaucher disease, and was mildly elevated in all other lipid storage disorders. Review of the literature identified 44 publications. Most findings were in line with our cohort. Several moderate elevations of biochemical markers were found across a wide range of other, mainly inherited metabolic, diseases. CONCLUSION: Measurement in plasma of LysoSLs and oxysterols by UPLC-MS/MS in combination with activity of chitotriosidase provides a useful first tier screening of patients suspected of lipid storage disease. The LysoSM-509/LysoSM ratio is a promising parameter in Niemann-Pick disease type C. Further studies in larger groups of untreated patients and controls are needed to improve the specificity of the findings.

Formation of exceptionally weak C-C bonds by metal-templated pinacol coupling.

The ability of the bis(imidazolyl)ketone ligand BMdiPhIK (bis(1-methyl-4,5-diphenylimidazolyl)ketone) to function as a redox active ligand has been investigated. The reduction of [M(BMdiPhIK)Cl2] (M = Fe and Zn) complexes resulted in a pinacol-type coupling to form dinuclear complexes featuring very weak and abnormally elongated C-C bonds (1.729(5) and 1.708(3) Å for Fe and Zn, respectively). Oxidation of these complexes using ferrocenium in the presence of Cl- ions regenerated the original [M(BMdiPhIK)Cl2] complexes, showing the reversibility of the coupling process. This makes it a potentially interesting approach for the storage of electrons and application of the BMdiPhIK ligand as a redox active ligand.

Epitaxy of oligothiophenes on alkali metal hydrogen phthalates: Simulations and experiments.

Three alkali metal hydrogen phthalate salts (denoted as XAP, X = K+, Rb+, and Cs+) are chosen as substrates for the growth of quaterthiophene (4T) and hexathiophene (6T) thin films by organic molecular beam epitaxy to study the influence of gradual changes of surface unit cell parameters on the epitaxialgrowth. The increment of substrate lattice parameters increases the distance between the planes that define the furrows where oligothiophene molecules lie, while keeping unmodified the interactions between the overlayer and the substrate. Atom-atom potential simulations predict the preferential azimuthal orientations of the overlayer, which are compared with those experimentally observed. The agreement between simulations and experiments about contact planes and orientation of the crystalline domains in the films is satisfactory for both 4T/XAP and 6T/XAP. The increasing width of the surface furrows existing on moving from KAP to RbAP and CsAP does not cause any significant variation of the orientation and density of the overlayer domains, demonstrating that the interaction between overlayer and substrate is the key factor guiding organic epitaxialgrowth.

[Internal medicine in the hospital setting]. / Médecine interne hospitalière: l'année en revue.

Management of all pathologies, and in particular that of the most frequent ones, should whenever possible be based on robust evidence and arguments. New studies published this year enable rationalizing of screening in certain clinical situations, more adequate treatment of others, and open the way for novel and apparently very effective treatments. Whether it be the screening of carotid stenosis, the treatment of pericarditis, of heart failure, of chronic obstructive lung disease or spontaneous bacterial peritonitis, paradigm changes are conceivable. This selective review of the literature summarizes certain studies published this year.

["Mobile" ECMO]. / Extracorporeal membrane oxygenation "mobile".

ECMO (extracorporeal membrane oxygenation) is a cardiac or respiratory support which uses the principle of extracorporeal circulation (ECC). It consists of a pump generating an output as well as a membrane oxygenating blood and removing CO2. Thanks to an ECMO mobile team, expert caregivers can now perform the circulatory support in primary centers and then transfer patients under assistance to the referral center. After a brief summary of the two different anatomical approaches (veno-arterial and veno-venous) as well as their indications, the authors will share their experience of two transferred patients under ECMO to Geneva. Referral center and ECMO mobile team concepts will then be detailed focusing on the present situation in Switzerland.

Nonextensivity and self-affinity in the mammalian neuromuscular junction.

We study time series and the spontaneous miniature end-plate potentials (MEPPs) of mammals recorded at neuromuscular junctions using two different approaches: generalized thermostatistics and detrended fluctuation analysis (DFA). Classical concepts establish that the magnitude of these potentials is characterized by Gaussian statistics and that their intervals are randomly displayed. First we show that MEPP distributions adequately satisfy the q-Gaussian distributions that maximize the Tsallis entropy, indicating their nonextensive and nonequilibrium behavior. We then examine the intervals between the miniature potentials via DFA, where the profile of the intervals between events configures a deviation from the expected random behavior. Some possible physiological substrates for these findings are discussed.

LDL from obese patients with the metabolic syndrome show increased lipid peroxidation and activate platelets.

AIMS/HYPOTHESIS: This study assessed oxidative stress in LDL from obese patients with the metabolic syndrome and compared it with that in LDL from type 2 diabetic patients or control volunteers. It also determined the effect on platelets of LDL from the three groups. METHODS: The profiles of lipids, fatty acids and fatty acid oxidation products were determined in LDL isolated from plasma of patients with the metabolic syndrome, patients with type 2 diabetes and volunteers (n = 10 per group). The effects of LDL from the participant groups on the platelet arachidonic acid signalling cascade and aggregation were investigated. RESULTS: Compared with LDL from control volunteers, LDL from obese metabolic syndrome and type 2 diabetic patients had lower cholesteryl ester, higher triacylglycerol and lower ethanolamine plasmalogen levels. Proportions of linoleic acid were decreased in phosphatidylcholine and cholesteryl esters in LDL from both patient groups. Among the markers of lipid peroxidation, oxidation products of linoleic acid (hydroxy-octadecadienoic acids) and malondialdehyde were increased by 59% and twofold, respectively in LDL from metabolic syndrome and type 2 diabetic patients. LDL from metabolic syndrome and type 2 diabetic patients were equally potent in activating the platelet arachidonic acid signalling cascade through increased phosphorylation of p38 mitogen-activated protein kinase and cytosolic phospholipase A(2), and through increased thromboxane B(2) formation. LDL from patients with the metabolic syndrome and type 2 diabetes potentiated platelet aggregation by threefold and 3.5-fold respectively, whereas control LDL had no activating effects on platelets. CONCLUSIONS/INTERPRETATION: The metabolic syndrome in obese patients, without or with diabetes, is associated with increased oxidative stress in LDL, which triggers platelet activation.

The role of stochasticity on compactness of the native state of protein peptide backbone.

A restricted angular random-walk model to build up polypeptide structures, which encompasses properties of the dihedral-angle Ramachandran map of folded proteins, is proposed to study the role of stochasticity on the compactness of the native state of proteins. Sample structures will be built with lengths ranging from 125 up to 400 amino acids for the different fractions of secondary structure motifs, from which dihedral angles were randomly chosen according to narrow Gaussian probability distributions. Physical properties of these polypeptide protein backbones such as the radius of gyration, the compactness parameter, the number of contacts, and the associated energy were computed and analyzed from an ensemble of thousands of realizations of protein peptide chains built with different rates of alpha-helix or beta-strand motifs. Such geometric and physical parameters are compared to data from several globular proteins extracted from the Protein Data Bank indicating that a certain (small fraction) randomness is an essential ingredient for achieving the folded state of proteins, suggesting that they are neither driven by deterministic nor random-walk processes.

Self-similarity and protein compactness.

The hydrophobic effect is the major factor that drives a protein toward collapse and folding. As a consequence of the folding process a hydrophobic core is shielded by the solvent-accessible surface area of the protein. We analyze the solvent-accessible surface area of 1825 nonhomolog protein chains deposited in the Brookhaven Protein Data Bank. This solvent-accessible surface area presents an intrinsic self-similarity behavior. The comparison between the accessible surface area as function of the number of amino acids and the accessible surface area as function of gyration radius supplies a measure of the scaling exponent close to the one observed by volume as function of radius of gyration or by mass-size exponent. The present finding indicates that the fractal analysis describes the protein compactness as an object packing between random spheres in percolation threshold and crumpled wires.

Ultrafast gaseous "half-wave plate".

We demonstrate that filaments generated by ultrashort laser pulses can induce a remarkably large birefringence in Argon over its whole length, resulting in an ultrafast "half-wave plate" for a copropagating probe beam. This birefringence originates from the difference between the nonlinear refractive indices induced by the filament on the axes parallel and orthogonal to its polarization. An angle of 45 degrees between the filament and the probe polarizations allows the realization of ultrafast Kerr-gates, with a switching time ultimately limited by the duration of the filamenting pulse.

Amino acid hydrophobicity and accessible surface area.

It is well known that the hydrophobic effect is the major factor that drives a protein toward collapse and folding. We analyze the variation of the solvent-accessible surface area of amino acids in small fragments of protein (3N45) . In this way, we look into 5526 protein chains deposited in the Brookhaven Protein Data Bank. The accessible surface area behaves as a power law for N9 . The comparison between the loss of accessible area and the self-similar behavior gives us a measure of the possibility of an amino acid to have apolar or polar side chain. It is therefore possible to infer about amino acid hydrophobicity, i.e., if one amino acid has a hydrophobic side chain or if it has a hydrophilic one. Furthermore, the present findings indicate that the variation of the accessible surface area describes an alternative hydrophobicity scale.