Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters










Publication year range
1.
Sci Rep ; 13(1): 15304, 2023 Sep 18.
Article in English | MEDLINE | ID: mdl-37723191

ABSTRACT

The application of a periodic nonresonant drive to a system allows the Floquet engineering of effective fields described by a broad class of quantum simulated Hamiltonians. The Floquet evolution is based on two different elements. The first one is a time-independent or stroboscopic evolution with an effective Hamiltonian corresponding to the quantum simulation target. The second element is the time evolution at the frequencies of the nonresonant driving and of its harmonics, denoted as micromotion. We examine experimentally and theoretically the harmonic dual-dressing Floquet engineering of a cold atomic two-level sample. Our focus is the dressing operation with small bare energies and large Rabi frequencies, where frequencies and amplitudes of the stroboscopic/micromotion time evolutions are comparable. At the kHz range of our dressed atom oscillations, we probe directly both the stroboscopic and micromotion components of the qubit global time evolution. We develop ad-hoc monitoring tools of the Floquet space evolution. The direct record of the time evolution following a pulsed excitation demonstrates the interplay between the two components of the spin precession in the Floquet space. From the resonant pumping of the dressed system at its evolution frequencies, Floquet eigenenergy spectra up to the fifth order harmonic of the dressing frequency are precisely measured as function of dressing parameters. Dirac points of the Floquet eigenenergies are identified and, correspondingly, a jump in the dynamical phase shift is measured. The stroboscopic Hamiltonian eigenfrequencies are measured also from the probe of the micromotion sidebands.These monitoring tools are appropriate for quantum simulation/computation investigations. Our results evidence that the stroboscopic phase shift of the qubit wavefunction contains an additional information that opens new simulation directions.

2.
Diabetol Metab Syndr ; 15(1): 2, 2023 Jan 02.
Article in English | MEDLINE | ID: mdl-36593495

ABSTRACT

INTRODUCTION: For individuals diagnosed with diabetes mellitus, the practice of properly oriented physical exercises brings significant benefits to the individual's health and is considered an indispensable tool for metabolic management. The individualization of exercise routines is an essential aspect for therapeutic success, despite the need to consider some general recommendations. This review is an authorized literal translation of the Brazilian Society of Diabetes (SBD) Guidelines 2021-2022, which is based on scientific evidence and provides guidance on physical activities and exercises aimed at individuals with type 1 and 2 diabetes. METHODS: SBD designated 9 specialists from its "Department of Diabetes, Exercise & Sports" to author chapters on physical activities and exercises directed to individuals with type 1 and 2 diabetes. The aim of these chapters was to highlight recommendations in accordance with Evidence Levels, based on what is described in the literature. These chapters were analyzed by the SBD Central Committee, which is also responsible for the SBD 2021-2022 guidelines. Main clinical inquiries were selected to perform a narrated review by using MEDLINE via PubMed. Top available evidence, such as high-quality clinical trials, large observational studies and meta-analyses related to physical activity and exercise advisory, were analyzed. The adopted MeSh terms were [diabetes], [type 1 diabetes], [type 2 diabetes], [physical activity] [physical exercise]. RESULTS: 17 recommendations were defined by the members. For this review, it was considered different Evidence Levels, as well as different Classes of Recommendations. As to Evidence Levels, the following levels were contemplated: Level A) More than one randomized clinical trial or a randomized clinical trial meta-analysis with low heterogeneity. Level B) Meta analysis with observational studies, one randomized clinical trial, sizeable observational studies and sub-groups analysis. Level C) Small non-randomized studies, cross-sectional studies, case control studies, guidelines or experts' opinions. In respect to Recommendation Classes, the following criteria were adopted: I. "Recommended": Meaning there was a consent of more than 90% of the panel; IIa. "Must be considered": meaning there is a general preference of the panel which 70-90% agrees; IIb. "Can be considered". 50-70% agrees; III Not recommended: There is a consensus that the intervention should not be performed. CONCLUSION: Physical exercise aids on the glycemic control of type 2 diabetes individuals while also decreasing cardiovascular risk in individuals with type 1 and 2 diabetes. Individuals diagnosed with diabetes should perform combined aerobic and resistance exercises in order to manage the disease. In addition, exercises focusing on flexibility and balance should be specially addressed on elderly individuals. Diabetes individuals using insulin as therapeutic treatment should properly monitor glycemia levels before, during and after exercise sessions to minimize health incidents, such as hypoglycemia.

3.
Opt Lett ; 42(15): 2930-2933, 2017 Aug 01.
Article in English | MEDLINE | ID: mdl-28957210

ABSTRACT

We demonstrate high-contrast electromagnetically induced absorption (EIA) bright resonances on the D1 line of K39 with characteristics comparable to those of the electromagnetically induced transparency (EIT) dark resonances observed in the same conditions. EIA is produced by the interaction of a weak probe beam with the atomic ground state driven in a degenerate coherent superposition by either a co- or counter-propagating pump beam. We have obtained an order of magnitude increase of the EIA's contrast with respect to previous similar experiments, performed with other alkalis, without compromising its linewidth. Furthermore, we show that the magneto-optic resonances can be continuously tuned from EIT to EIA by changing the relative handedness of circular polarizations of pump and probe beams, or depending on whether they co- or counter-propagate. This opens new perspectives in the use of EIA in a broad range of physical domains and in a large wealth of potential applications in optics and photonics.

4.
Arq. bras. endocrinol. metab ; 42(1): 76-81, fev. 1998.
Article in Portuguese | LILACS | ID: lil-214546

ABSTRACT

Apesar das grandes controvérsias a respeito dos efeitos benéficos do exercício na tolerância à glicose e no controle metabólico, admite-se, atualmente, que a prática de uma atividade física deva ser indicada em associaçao à dieta e ao uso de hipoglicemiantes orais ou insulina no tratamento de pacientes diabéticas. Nos diabéticos do tipo 2 (nao dependentes de insulina exógena) pouco propensos a hipoglicemia, frequentemente obesos e portadores de dislipidemias e doenças cardiovasculares, os efeitos benéficos do exercício sao óbvios. Já nos diabéticos do tipo 1 (dependentes de insulina exógena), o exercício pode provocar tanto hipo como hiperglicemia caso o paciente nao esteja adequadamente compensado. Para prevení-las, assim como para evitar o agravamento de complicaçoes neurológicas e oftálmicas já existentes, deve-se escolher adequadamente o tipo de exercício e promover os ajustes adequados na dieta e na dose da medicaçao. Nessa revisao, discutiremos os aspectos básicos da prescriçao do exercício (tipo, duraçao, intensidade e modalidade esportiva) e as peculiaridades dessa prescriçao para indivíduos diabéticos.


Subject(s)
Humans , Diabetes Mellitus/therapy , Exercise , Diabetes Mellitus, Type 2/therapy , Diabetes Mellitus, Type 1/therapy , Prescriptions
SELECTION OF CITATIONS
SEARCH DETAIL
...