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1.
Pharmacol Res ; 203: 107183, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38631619

RESUMO

INTRODUCTION: Data on positive rechallenge in idiosyncratic drug-induced liver injury (DILI) are scarce. We aim to analyse the clinical presentation, outcome and drugs associated with positive rechallenge in two DILI registries. METHODS: Cases from the Spanish and Latin American DILI registries were included. Demographics, clinical characteristics and outcome of cases with positive rechallenge according to CIOMS/RUCAM and current definitions were analysed. RESULTS: Of 1418 patients with idiosyncratic DILI, 58 cases had positive rechallenge (4.1%). Patients with positive rechallenge had shorter duration of therapy (p=0.001) and latency (p=0.003). In patients with rechallenge, aspartate transaminase levels were increased (p=0.026) and showed a prolonged time to recovery (p=0.020), albeit no differences were seen in terms of fatal outcomes. The main drug implicated in rechallenge was amoxicillin-clavulanate (17%). The majority of re-exposure events were unintentional (71%). Using both existing definitions of positive rechallenge, there were four cases which exclusively fulfilled the current criteria and five which only meet the historical definition. All cases of positive rechallenge, irrespective of the pattern of damage, fulfilled the criteria of either alanine transaminase (ALT) ≥3 times the upper limit of normal (ULN) and/or alkaline phosphatase (ALP) ≥2 times ULN. CONCLUSIONS: Episodes of rechallenge were characterised by shorter duration of therapy and latency, and longer time to resolution, but did not show an increased incidence of fatal outcome. Based on our findings, ALT ≥3 times ULN and/or ALP ≥2 times ULN, regardless of the pattern of damage, is proposed as a new definition of rechallenge in DILI.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Sistema de Registros , Humanos , Doença Hepática Induzida por Substâncias e Drogas/epidemiologia , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/sangue , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Idoso , Estudos Prospectivos , Espanha/epidemiologia , Aspartato Aminotransferases/sangue , Combinação Amoxicilina e Clavulanato de Potássio/efeitos adversos
2.
Phys Rev E ; 108(4-1): 044102, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37978615

RESUMO

We study the probability distribution function of the long-time values of observables being time-evolved by Hamiltonians modeling clean and disordered one-dimensional chains of many spin-1/2 particles. In particular, we analyze the return probability and its version for a completely extended initial state, the so-called spectral form factor. We complement our analysis with the spin autocorrelation and connected spin-spin correlation functions, both of interest in experiments with quantum simulators. We show that the distribution function has a universal shape provided the central limit theorem holds. Explicitly, the shape is exponential for the return probability and spectral form factor, meanwhile it is Gaussian for the few-body observables. We also discuss implications over the so-called many-body localization. Remarkably, our approach requires only a single sample of the dynamics and small system sizes, which could be quite advantageous when dealing specially with disordered systems.

3.
Rev Gastroenterol Mex (Engl Ed) ; 88(4): 381-391, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37833134

RESUMO

Point-of-care ultrasound (POCUS) refers to the use of ultrasound imaging through pocket-sized sonographic devices at the patient's bedside, to make a diagnosis or direct a procedure and immediately answer a clinical question. Its goal is to broaden the physical examination, not to replace conventional ultrasound studies. POCUS has evolved as a complement to physical examination and has been adopted by different medical specialties, including hepatology. A narrative synthesis of the evidence on the applications of POCUS in hepatology was carried out, describing its usefulness in the diagnosis of cirrhosis of the liver, metabolic dysfunction-associated steatotic liver disease (MASLD), decompensated cirrhosis, and portal hypertension. The review also encompasses more recent applications in the hemodynamic evaluation of the critically ill patient with cirrhosis of the liver, patients with other liver diseases, as well as in the ultrasound guidance of procedures. POCUS could make up part of the daily clinical practice of gastroenterologists and hepatologists, simplifying the initial evaluation of patients and optimizing clinical management. Its accessibility, ease of use, and low adverse event profile make POCUS a useful tool for the properly trained physician in the adequate clinical setting. The aim of this review was to describe the available evidence on the usefulness of POCUS in the daily clinical practice of gastroenterologists and hepatologists.


Assuntos
Gastroenterologia , Sistemas Automatizados de Assistência Junto ao Leito , Humanos , Ultrassonografia/métodos , Cirrose Hepática , Exame Físico
4.
Sci Rep ; 13(1): 8312, 2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37221188

RESUMO

We present a Lie algebraic approach to a Hamiltonian class covering driven, parametric quantum harmonic oscillators where the parameter set-mass, frequency, driving strength, and parametric pumping-is time-dependent. Our unitary-transformation-based approach provides a solution to our general quadratic time-dependent quantum harmonic model. As an example, we show an analytic solution to the periodically driven quantum harmonic oscillator without the rotating wave approximation; it works for any given detuning and coupling strength regime. For the sake of validation, we provide an analytic solution to the historical Caldirola-Kanai quantum harmonic oscillator and show that there exists a unitary transformation within our framework that takes a generalized version of it onto the Paul trap Hamiltonian. In addition, we show how our approach provides the dynamics of generalized models whose Schrödinger equation becomes numerically unstable in the laboratory frame.

5.
Entropy (Basel) ; 25(2)2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36832572

RESUMO

Survival probability measures the probability that a system taken out of equilibrium has not yet transitioned from its initial state. Inspired by the generalized entropies used to analyze nonergodic states, we introduce a generalized version of the survival probability and discuss how it can assist in studies of the structure of eigenstates and ergodicity.

6.
Occup Med (Lond) ; 73(3): 128-132, 2023 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-36719103

RESUMO

BACKGROUND: Antibody (Ab) tests for SARS-CoV-2 virus allows for the estimation of incidence, level of exposure and duration of immunity acquired by a previous infection. In health workers, the hospital setting might convey a greater risk of infection. AIMS: To describe the frequency of immunoglobulin G (IgG) Abs (IgG-Abs) to the SARS-CoV-2 virus among workers at a third-level university hospital in Colombia. METHODS: In this cross-sectional study, we included medical and non-medical personnel with at least one real-time polymerase chain reaction (RT-PCR)/antigen test between March 2020 and March 2021. In April 2021, an IgG-Ab test against SARS-CoV-2 was conducted for all participants and replicated 2 weeks later in a random sample (10%). The frequency of IgG-Abs is presented based on status (positive/negative) and time elapsed since RT-PCR/antigen test (<3 months, 3-6 months, >6 months). RESULTS: We included 1021 workers (80% women, median age 34 years (interquartile range 28-42), 73% medical personnel, 23% with previous positive RT-PCR/antigen). The overall seroprevalence was 35% (95% CI 31.6-37.4, 35% in medical and 33% in non-medical personnel). For those with a previous positive RT-PCR/antigen test, the seroprevalence was 90% (<3 months), 82% (3-6 months) and 48% (>6 months). In participants with a previous negative RT-PCR/antigen test, the seroprevalence was 17% (<3 months), 21% (3-6 months) and 29% (>6 months). CONCLUSIONS: High IgG-Ab positivity was found in hospital personnel, regardless of work activities. The prevalence of detectable Abs differed by previous RT-PCR/antigen status and time elapsed since the diagnostic test.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Feminino , Adulto , Masculino , COVID-19/epidemiologia , Colômbia/epidemiologia , Estudos Soroepidemiológicos , Estudos Transversais , Imunoglobulina G , Pessoal de Saúde , Recursos Humanos em Hospital , Hospitais
7.
SEMERGEN, Soc. Esp. Med. Rural Gen. (Ed. Impr.) ; 48(1): 3-13, Ene. - Feb. 2022. ilus, tab, graf
Artigo em Espanhol | IBECS | ID: ibc-205195

RESUMO

Objetivo: Valorar la interpretación de ApnealinkTM® (AL) por médicos de atención primaria (MAP), y la alcanzada mediante poligrafía respiratoria (PGR) en la Unidad de Sueño Hospitalaria (USH) en pacientes con alta probabilidad de síndrome de apnea e hipopnea del sueño (SAHS). Métodos: Se recogen aleatoriamente, durante tres meses, pacientes seleccionados en USH para estudio mediante PGR, con elevada probabilidad de SAHS que aceptaron repetir estudio mediante AL. La USH corregía la PGR según normativa SEPAR; el MAP corregía el AL y planteaba manejo. Se analizaron los pacientes con estudios válidos(tiempo registro ≥ 240 min) para ambos dispositivos, comparándose resultados. Se consideró el estudio AL automático y corregido, considerando un índice de desaturación de oxihemoglobina (ODI) al 4% (ODI 4%), (AL 4%) y al 3% (ODI 3%), (AL 3%). Cuando ODI 4% era ≥ 12/h, se estableció diagnóstico SAHS moderado/grave, suponiendo un IAH ≥ 15/h. Para interpretar AL con ODI 3% y tratamiento, se siguieron criterios SEPAR. Se compararon los resultados para las mismas variables del AL frente a PGR. Resultados: Se incluyeron 43 pacientes válidos para AL, 45 para PGR y 41 válidos para ambos estudios. El estudio AL 4% mostró 27 (62,8%) positivos (OR 5,5, p < 0,05), que el AL 3% corroboró con IAH ≥ 15/h. La PGR detectó 19 (42,2%) con IAH ≥ 15/h; el AL 3% detectó 31 (72%). El análisis del AL 4% y AL 3% comparado con PGR no mostró diferencias de diagnóstico o manejo. Se compararon los resultados para las mismas variables del AL frente a PGR.Conclusiones: Existe equivalencia entre las decisiones del MAP y la USH. El AL sería un buen método diagnóstico de SAHS en atención primaria, en pacientes seleccionados con alta probabilidad de SAHS (AU)


Objectives: To assess diagnosis and therapeutic decisions-making by General Practitioners (GP) using ApnealinkTM® (AL) in patients with high suspicion of obstructive sleep apnea (OSA), in comparison with conclusions of Hospital Sleep Unit (HSU) specialists based on home respiratory polygraphy (PGR) results. Methods: This study involved patients previously selected by HSU for sleep testing by PGR. After it, patients were offered to complete AL test. PGR was checked at HSU; AL was checked by hemoglobin desaturation index of 4% (4% ODI), (4% AL) and 3% (3% ODI) patients with positive test to proceed with CPAP; and those with negative test for further testing. Automatically adjusted 4% AL, was considered valid as it was demonstrated to be equivalent to manual AL. Results were compared by automatically adjusted 3%AL against PGR results. Results: 48 patients were collected. 43 had AL valid test, 45 had PGR valid study, and 41 had both valid test. 27 patients (62,8%) had positive 4% AL (OR 5,51, p < 0,05), that showed AHI ≥ 15/h at 3% AL test; and 19 patients (42,2%) had a positive PGR test. 31 (72%) patients had a positive 3% AL. AL had shown to be a good screening method of SAHS. Conclusions: There is equivalence between the decisions of GP and HSU. AL is a good diagnostic tool and screening method for OSA in primary care when it is used in patients with high suspicion of moderate-severe OSA (AU)


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Apneia Obstrutiva do Sono/diagnóstico , Atenção Primária à Saúde , Clínicos Gerais , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Estudos Transversais , Polissonografia , Oximetria
8.
Semergen ; 48(1): 3-13, 2022.
Artigo em Espanhol | MEDLINE | ID: mdl-34454826

RESUMO

OBJECTIVES: To assess diagnosis and therapeutic decisions-making by General Practitioners (GP) using ApnealinkTM® (AL) in patients with high suspicion of obstructive sleep apnea (OSA), in comparison with conclusions of Hospital Sleep Unit (HSU) specialists based on home respiratory polygraphy (PGR) results. METHODS: This study involved patients previously selected by HSU for sleep testing by PGR. After it, patients were offered to complete AL test. PGR was checked at HSU; AL was checked by hemoglobin desaturation index of 4% (4% ODI), (4% AL) and 3% (3% ODI) patients with positive test to proceed with CPAP; and those with negative test for further testing. Automatically adjusted 4% AL, was considered valid as it was demonstrated to be equivalent to manual AL. Results were compared by automatically adjusted 3%AL against PGR results. RESULTS: 48 patients were collected. 43 had AL valid test, 45 had PGR valid study, and 41 had both valid test. 27 patients (62,8%) had positive 4% AL (OR 5,51, p < 0,05), that showed AHI ≥ 15/h at 3% AL test; and 19 patients (42,2%) had a positive PGR test. 31 (72%) patients had a positive 3% AL. AL had shown to be a good screening method of SAHS. CONCLUSIONS: There is equivalence between the decisions of GP and HSU. AL is a good diagnostic tool and screening method for OSA in primary care when it is used in patients with high suspicion of moderate-severe OSA.


Assuntos
Clínicos Gerais , Síndromes da Apneia do Sono , Apneia Obstrutiva do Sono , Humanos , Oximetria , Polissonografia , Atenção Primária à Saúde , Síndromes da Apneia do Sono/diagnóstico , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/terapia
9.
Prog Lipid Res ; 81: 101082, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33383022

RESUMO

During development, the human fetus accrues the highest proportion of fat of all mammals. Precursors of fat lobules can be found at week 14 of pregnancy. Thereafter, they expand, filling with triacylglycerols during pregnancy. The resultant mature lipid-filled adipocytes emerge from a developmental programme of embryonic stem cells, which is regulated differently than adult adipogenesis. Fetal triacylglycerol synthesis uses glycerol and fatty acids derived predominantly from glycolysis and lipogenesis in liver and adipocytes. The fatty acid composition of fetal adipose tissue at the end of pregnancy shows a preponderance of palmitic acid, and differs from the mother. Maternal diabetes mellitus does not influence this fatty acid profile. Glucose oxidation is the main source of energy for the fetus, but mitochondrial fatty acid oxidation also contributes. Indirect evidence suggests the presence of lipoprotein lipase in fetal adipose tissue. Its activity may be increased under hyperinsulinemic conditions as in maternal diabetes mellitus and obesity, thereby contributing to increased triacylglycerol deposition found in the newborns of such pregnancies. Fetal lipolysis is low. Changes in the expression of genes controlling metabolism in fetal adipose tissue appear to contribute actively to the increased neonatal fat mass found in diabetes and obesity. Many of these processes are under endocrine regulation, principally by insulin, and show sex-differences. Novel fatty acid derived signals such as oxylipins are present in cord blood with as yet undiscovered function. Despite many decades of research on fetal lipid deposition and metabolism, many key questions await answers.


Assuntos
Diabetes Mellitus , Metabolismo dos Lipídeos , Adipogenia , Tecido Adiposo/metabolismo , Animais , Diabetes Mellitus/metabolismo , Feminino , Feto/metabolismo , Humanos , Recém-Nascido , Obesidade/metabolismo , Gravidez
10.
J Mycol Med ; 31(2): 101047, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33087307

RESUMO

PURPOSE: In this paper, we reported three distinct cases of tinea, including tenia ungulum, tenia pedis, and tenia cruris caused by the infection of Nannizzia nana in the immunocompetent patients who were also the residents of Guatemala. Dermatophytes were identified phenotypically and genotypically. Thereafter, DNA was extracted from the fungal isolates and a fragment of the ITS1-5.8S-ITS2 region was amplified and sequenced. The direct visual examination revealed the presence of fungal hyphae and arthroconidia. These characteristic morphological features resembled with the general features of the species, Nannizzia nana. Furthermore, nucleotide sequences that were amplified from the fungal isolates, confirmed the species identification. Thereafter, all the patients were treated with Terbinafine (250mg) through oral route for two weeks, except the patient with onychomycosis, who received the same treatment but for an extended period of three months. All the patients showed complete recovery from dermatophytosis. This study contributes to a better understanding of the epidemiology of human infections that are caused by dermatophytes, often misdiagnosed. Dermatophytes are currently less known but are now being more frequently identified due to the improvements in the diagnostic techniques.


Assuntos
Arthrodermataceae/genética , Dermatomicoses/diagnóstico , Adulto , Antifúngicos/uso terapêutico , Arthrodermataceae/patogenicidade , DNA Fúngico/genética , Dermatomicoses/tratamento farmacológico , Dermatomicoses/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular , Terbinafina/uso terapêutico
11.
J Eur Acad Dermatol Venereol ; 35(4): 844-883, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32976663

RESUMO

Dermatophyte infections are the most common fungal infections in humans; among them, tinea capitis (TC) - the most contagious fungal infection - is caused by anthropophilic, zoophilic and geophilic dermatophytes. The purpose of this systematic review was to determine the different aetiological variants involved in TC and the overall epidemiology of the causes of this infection in the last two decades. We searched the MEDLINE (PubMed) and Embase databases for articles published from July 2000 to August 2019 using the following search terms: 'Tinea capitis', 'Africa', 'America', 'Asia', 'Europe', 'Oceania', and the names of the countries on each continent. The flow of information through the different phases in this systematic review was depicted using a PRISMA flow diagram, which mapped the number of records identified, included and excluded, and the reasons for exclusion. Our findings indicate that the frequency of different aetiologic agents of TC in the reported studies varied globally, from 0.4-87.7% in Africa, 0.2-74.0% in North America, 0.0-91.2% in Eastern Asia, 0.0-69.0% in Eastern Europe and 2.9-86.4% in Oceania. Microsporum canis is the most frequent reported zoophilic agent worldwide, while Trichophyton violaceum and Trichophyton tonsurans are the predominant anthropophilic agents. Over time, the frequency of these latter fungal infections has increased globally, and these fungi have become the major species globally. Anthropophilic transmission - the most prevalent type of transmission - could be explained by two factors: (i) the socioeconomic status of affected countries and population groups with associated risk factors and (ii) movement of populations importing new causes of infection to areas where they had not been encountered previously. We observed that intercontinental migration and travel; globalization; environmental, climatic and ecological changes; and accelerated evolution of health technologies may influence the observed epidemiological changes and, consequently, contributed to the variations in the global status of TC.


Assuntos
Tinha do Couro Cabeludo , Arthrodermataceae , Ásia , Europa (Continente) , Europa Oriental , Humanos , Microsporum , Tinha do Couro Cabeludo/epidemiologia , Trichophyton
12.
J Appl Physiol (1985) ; 129(1): 152-161, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32584666

RESUMO

Most mammals have a poor tolerance to hypoxia, and prolonged O2 restriction can lead to organ injury, particularly during fetal and early postnatal life. Nevertheless, the llama (Lama Glama) has evolved efficient mechanisms to adapt to acute and chronic perinatal hypoxia. One striking adaptation is the marked peripheral vasoconstriction measured in the llama fetus in response to acute hypoxia, which allows efficient redistribution of cardiac output toward the fetal heart and adrenal glands. This strong peripheral vasoconstrictor tone is triggered by a carotid body reflex and critically depends on α-adrenergic signaling. A second adaptation is the ability of the llama fetus to protect its brain against hypoxic damage. During hypoxia, in the llama fetus there is no significant increase in brain blood flow. Instead, there is a fall in brain O2 consumption and temperature, together with a decrease of Na+-K+-ATPase activity and Na+ channels expression, protecting against seizures and neuronal death. Finally, the newborn llama does not develop pulmonary hypertension in response to chronic hypoxia. In addition to maintaining basal pulmonary arterial pressure at normal levels the pulmonary arterial pressor response to acute hypoxia is lower in highland than in lowland llamas. The protection against hypoxic pulmonary arterial hypertension and pulmonary contractile hyperreactivity is partly due to increased hemoxygenase-carbon monoxide signaling and decreased Ca2+ sensitization in the newborn llama pulmonary vasculature. These three striking physiological adaptations of the llama allow this species to live and thrive under the chronic influence of the hypobaric hypoxia of life at high altitude.


Assuntos
Camelídeos Americanos , Aclimatação , Adaptação Fisiológica , Altitude , Animais , Feminino , Humanos , Hipóxia , Recém-Nascido , Gravidez
13.
Clin Microbiol Infect ; 26(8): 1092.e1-1092.e6, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31901492

RESUMO

OBJECTIVE: To evaluate the effectiveness and tolerability of secnidazole combined with high-dose mebendazole for treatment of 5-nitroimidazole-resistant giardiasis. METHOD: Adults with microscopically verified Giardia intestinalis monoinfection attending a secondary level hospital in Matanzas City, Cuba were prospectively included in a cohort. A recently introduced treatment ladder consisting of metronidazole as first-line treatment, followed by secnidazole, tinidazole, secnidazole plus mebendazole and quinacrine as second-to fifth-line treatments, respectively, was used. Adverse events and treatment success were determined by questioning and microscopy on concentrated stool samples, respectively on days 3, 5 and 7 after the end of treatment. If G. intestinalis was detected on day 3, 5 or 7, then the infection was classified as refractory and no further microscopy was performed. RESULTS: A total of 456 individuals were included. Metronidazole, 500 mg three times daily for 5 days, cured 248/456 (54%) patients. A single 2-g secnidazole dose as second-line treatment cured 50/208 (24%) patients. A single 2-g tinidazole dose as third-line treatment cured 43/158 (27%) patients. Three rounds of 5-nitroimidazole therapy therefore cured 341/456 (75%) patients. Secnidazole plus mebendazole (200 mg every 8 hours for 3 days) cured 100/115 (87%) of nitroimidazole refractory infections. Quinacrine cured the remaining 15 patients. All treatments were well tolerated. CONCLUSIONS: 5-Nitroimidazole refractory giardiasis was common, indicating that an alternative first-line treatment may be needed. Retreatment of metronidazole refractory giardiasis with an alternative 5-nitroimidazole was suboptimal, indicating cross-resistance. Mebendazole plus secnidazole were well tolerated and effective for the treatment of 5-nitroimidazole refractory G. intestinalis infection in this setting.


Assuntos
Antiprotozoários/administração & dosagem , Giardíase/tratamento farmacológico , Mebendazol/administração & dosagem , Metronidazol/análogos & derivados , Quinacrina/administração & dosagem , Adulto , Idoso , Antiprotozoários/farmacologia , Cuba , Esquema de Medicação , Resistência a Medicamentos/efeitos dos fármacos , Quimioterapia Combinada , Fezes/parasitologia , Feminino , Giardia lamblia/efeitos dos fármacos , Giardia lamblia/isolamento & purificação , Humanos , Masculino , Mebendazol/farmacologia , Metronidazol/administração & dosagem , Metronidazol/farmacologia , Pessoa de Meia-Idade , Nitroimidazóis/uso terapêutico , Estudos Prospectivos , Quinacrina/farmacologia , Resultado do Tratamento , Adulto Jovem
14.
Phys Rev E ; 102(6-1): 062126, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33465957

RESUMO

In a disordered system, a quantity is self-averaging when the ratio between its variance for disorder realizations and the square of its mean decreases as the system size increases. Here, we consider a chaotic disordered many-body quantum system and search for a relationship between self-averaging behavior and the properties of the distributions over disorder realizations of various quantities and at different timescales. An exponential distribution, as found for the survival probability at long times, explains its lack of self-averaging, since the mean and the dispersion are equal. Gaussian distributions, however, are obtained for both self-averaging and non-self-averaging quantities. Our studies show also that one can make conclusions about the self-averaging behavior of one quantity based on the distribution of another related quantity. This strategy allows for semianalytical results, and thus circumvents the limitations of numerical scaling analysis, which are restricted to few system sizes.

15.
Phys Rev E ; 100(2-1): 022142, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31574697

RESUMO

This work shows that dynamical features typical of full random matrices can be observed also in the simple finite one-dimensional (1D) noninteracting Anderson model with nearest-neighbor couplings. In the thermodynamic limit, all eigenstates of this model are exponentially localized in configuration space for any infinitesimal on-site disorder strength W. But this is not the case when the model is finite and the localization length is larger than the system size L, which is a picture that can be experimentally investigated. We analyze the degree of energy-level repulsion, the structure of the eigenstates, and the time evolution of the finite 1D Anderson model as a function of the parameter ξ∝(W^{2}L)^{-1}. As ξ increases, all energy-level statistics typical of random matrix theory are observed. The statistics are reflected in the corresponding eigenstates and also in the dynamics. We show that the probability in time to find a particle initially placed on the first site of an open chain decays as fast as in full random matrices and much faster than when the particle is initially placed far from the edges. We also see that at long times, the presence of energy-level repulsion manifests in the form of the correlation hole. In addition, our results demonstrate that the hole is not exclusive to random matrix statistics, but emerges also for W=0, when it is in fact deeper.

16.
Phys Rev E ; 100(1-1): 012218, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31499773

RESUMO

Quantum systems whose classical counterparts are chaotic typically have highly correlated eigenvalues and level statistics that coincide with those from ensembles of full random matrices. A dynamical manifestation of these correlations comes in the form of the so-called correlation hole, which is a dip below the saturation point of the survival probability's time evolution. In this work, we study the correlation hole in the spin-boson (Dicke) model, which presents a chaotic regime and can be realized in experiments with ultracold atoms and ion traps. We derive an analytical expression that describes the entire evolution of the survival probability and allows us to determine the time scales of its relaxation to equilibrium. This expression shows remarkable agreement with our numerical results. While the initial decay and the time to reach the minimum of the correlation hole depend on the initial state, the dynamics beyond the hole up to equilibration is universal. We find that the relaxation time of the survival probability for the Dicke model increases linearly with system size.

17.
Enferm. univ ; 16(2): 157-170, abr.-jun. 2019. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS, BDENF - Enfermagem | ID: biblio-1012019

RESUMO

Resumen Introducción: En Chile, las enfermeras/os tienen respaldo legal para gestionar el cuidado, esto facilita el desarrollo de competencias para ejercer autonomía y liderazgo. Actualmente persisten barreras para transitar hacia un reconocimiento real de la independencia profesional. Objetivo: Develar la experiencia vivida de enfermeras con cargos en niveles de jefatura respecto al propio desarrollo para lograr el liderazgo y autonomía profesional. Metodología: Estudio cualitativo, descriptivo-interpretativo, desde la trayectoria fenomenológica de Edmund Husserl. Muestreo selectivo de caso homogéneo de tres enfermeras que desempeñaban rol de jefatura en instituciones de salud, región Valparaíso, Chile. Participación consentida. Entrevista no estructurada. Análisis del discurso utilizando el modelo de liderazgo integral de Ken Wilber. Resultados: Categorías: Conciencia del líder «ser inquieta...intelectualmente¼. Construyendo competencias «el liderazgo se aprende¼. Transitando hacia el ejercicio de la autonomía y el liderazgo, "para el posicionamiento hay que luchar". El peso de las estructuras organizacionales «tu rol es parte de un hospital¼. Interpretación: El ejercicio del liderazgo y la autonomía se fundamenta en competencias actitudinales por sobre las cognitivas y técnicas. Existe mayor apoyo y reconocimiento a nivel institucional, que al interior del equipo de salud. Persisten limitaciones para lograr máxima expresión del liderazgo y autonomía, por persistencia de modelos institucionales hegemónicos, centrados en decisiones médicas y desconocimiento del rol integrado. Conclusión: El líder se mueve en un escenario dual, entre un menor reconocimiento del equipo y un creciente empoderamiento del rol autónomo y visibilidad a nivel directivo institucional.


Abstract Introduction: In Chile, nurses have legal support to manage care, a situation which facilitates the development of competencies to perform with autonomy and leadership; however, barriers still persist while moving towards a real acknowledgement of professional independency. Objective: To unveil the lived experience of nurses in executive roles regarding their own development towards leadership and professional autonomy. Methodology: This is a descriptive and interpretative qualitative study framed by the Edmund Husserl phenomenological approach. The sample by homogeneous case included three nurses in executive roles in health institutions in Valparaiso, Chile. The participation was by consent. An unstructured interview was used. For the discourse analysis, the Ken Wilber integral leadership model was followed. Results: Categories: Leadership awareness <being inquiring… intellectually>… Building Competencies <leadership is learned>. Moving towards the practice of autonomy and leadership, "positioning requires striving". Weight of the organizational structures <your role is part of a hospital>. Interpretation: A practice of leadership and autonomy is based on attitude competencies over the cognitive and technical ones. Nevertheless, there still persist limitations to achieve a maximal expression of leadership and autonomy due to hegemonic institutional models which focus on medical decisions and neglect the integrated roles. Conclusion: The leader moves in a dual setting between a lower acknowledgement from the team, and a higher empowerment of the autonomous role and the visibility at the institutional directive level.


Resumo Introdução: No Chile, as enfermeiras/os têm apoio legal para gerenciar o cuidado, isto facilita o desenvolvimento de competências para exercer autonomia e liderança. Atualmente, persistem barreiras para transitar em direção a um reconhecimento real da independência profissional. Objetivo: Desvendar a experiência vivida de enfermeiras com cargos em níveis de chefia ao respeito do próprio desenvolvimento, para atingir a liderança e autonomia profissional. Metodologia: Estudo qualitativo, descritivo-interpretativo, desde a trajetória fenomenológica de Edmund Husserl. Amostragem seletiva de caso homogéneo de três enfermeiras que desempenhavam papel de chefia em instituições de saúde, região Valparaíso, Chile. Participação consentida. Entrevista não estruturada. Análise de discurso, utilizou-se o modelo de liderança integral de Ken Wilber. Resultados: Categorias: Consciência do líder «ser irrequieta...intelectualmente¼. Ir construindo competências «a liderança se aprende¼. Transitar em direção ao exercício da autonomia e a liderança, "para o posicionamento tem que lutar". O peso das estruturas organizacionais «seu rolo é parte de um hospital¼. Interpretação: O Exercício da liderança e a autonomia fundamenta-se em competências atitudinais, sobre as cognitivas e técnicas. Existe maior apoio e reconhecimento a nível institucional, que no interior da equipe de saúde. Persistem limitações para atingir a máxima expressão de liderança e autonomia, por persistência de modelos institucionais hegemónicos, centrados em decisões médicas e desconhecimento do rolo integrado. Conclusão: O líder movimenta-se em um cenário dual, entre um menor reconhecimento da equipe e um empoderamento crescente do rolo autónomo e visibilidade a nível diretivo institucional.

18.
J Neuroimmunol ; 333: 476964, 2019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-31112803

RESUMO

It has been hypothesized that anterior chamber-associated immune deviation (ACAID) to neural antigens induced prior to central nervous system injury can inhibit self-reactivity and lessen secondary degeneration. This work evaluated the effect of ACAID induced to three neural tissue-derived extracts (whole extract, cytosolic extract, CE; or organelle-membrane extract) prior to optic nerve injury on retinal ganglion cell (RGC) survival. The results show that only ACAID to the CE increased RGC survival at 7 and14 days post-injury (dpi). This effect was achieved by retinal polarization towards an anti-inflammatory profile, driven by regulatory T cells and M2-type macrophages at 7 dpi.


Assuntos
Câmara Anterior/imunologia , Autoantígenos/imunologia , Privilégio Imunológico/imunologia , Traumatismos do Nervo Óptico/imunologia , Retina/imunologia , Animais , Autoimunidade , Citosol/imunologia , Feminino , Hipersensibilidade Tardia/imunologia , Macrófagos/imunologia , Compressão Nervosa , Fatores de Crescimento Neural/biossíntese , Fatores de Crescimento Neural/genética , Ratos , Ratos Wistar , Células Ganglionares da Retina/imunologia , Linfócitos T Reguladores/imunologia
19.
Annu Int Conf IEEE Eng Med Biol Soc ; 2019: 1159-1162, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31946099

RESUMO

Acetylcholine is a neurotransmitter and a neuromodulator found in the autonomic, peripheral and central nervous systems. Diazinon is a pesticide with toxic effects on humans, such as the inhibition of acetylcholine. In this paper, a biosensor is proposed for the detection of acetylcholine (range 70 - 1000 µM) and diazinon (range 0.3 - 20000 ppb). This biosensor combines a pH-sensitive layer of reduced graphene oxide functionalized with 4-aminobenzoic acid and acetylcholinesterase. This enzyme was immobilized on reduced graphene oxide and it catalyzed the conversion of acetylcholine into choline and acetic acid, locally decreasing the pH value and triggering the sensor response. The limit of detection for the acetylcholine and diazinon were 70 µM and 0.3 ppb, respectively.


Assuntos
Acetilcolina , Técnicas Biossensoriais , Diazinon , Acetilcolina/análise , Diazinon/análise , Eletrodos , Enzimas Imobilizadas , Humanos
20.
J Helminthol ; 93(2): 187-194, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29386074

RESUMO

In the Pampa region of Argentina, farming activities have been performed since the beginning of the 20th century, but in the 1990s, land-use patterns rapidly changed towards intensive agriculture and poultry breeding. This study compares the helminth community of Akodon azarae (Rodentia) among three habitats with different land use in pampean agroecosystems: poultry farms, mono-cultivated fields and abandoned fields (not used for 35 years), under the prediction that there will be greater helminth richness and diversity in mice from abandoned fields compared to those from the other habitats. Nevertheless, the highest abundance of A. azarae occurred on poultry farms, the habitat most disturbed by human activity, while cultivated fields showed the lowest. Helminth richness and diversity were significantly higher on poultry farms than in the other habitats, due to the presence of Trichuris laevitestis, Protospirura numidica criceticola and cysts of Taenia taeniaeformis. We suggest that the helminth fauna of A. azarae can survive on poultry farms despite disturbance from farming activities, because rodents can move and get shelter within farm perimeter fences, where dense and high vegetation grows. This farm area could offer good conditions for geohelminth development, while chicken sheds could attract insects that are intermediate hosts of helminths with indirect life cycles. On the contrary, agrochemicals applied in cultivated fields would negatively influence helminth diversity and composition, by decreasing host populations (arthropods and rodents) and affecting free larval stages of geohelminths.


Assuntos
Agricultura , Ecossistema , Helmintos/isolamento & purificação , Roedores/parasitologia , Sigmodontinae/parasitologia , Animais , Argentina , Fazendas , Estágios do Ciclo de Vida , Aves Domésticas , Doenças dos Roedores/parasitologia , Estações do Ano , Taenia , Trichuris
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