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1.
Sleep Med Rev ; 47: 28-38, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31252334

RESUMO

An ever-growing number of electromagnetic (EM) emission sources elicits health concerns, particularly stemming from the ubiquitous low to extremely low frequency fields from power lines and appliances, and the radiofrequency fields emitted from telecommunication devices. In this article we review the state of knowledge regarding possible impacts of electromagnetic fields on melatonin secretion and on sleep structure and the electroencephalogram of humans. Most of the studies on the effects of melatonin on humans have been conducted in the presence of EM fields, focusing on the effects of occupational or residential exposures. While some of the earlier studies indicated that EM fields may have a suppressive effect on melatonin, the results cannot be generalized because of the large variability in exposure conditions and other factors that may influence melatonin. For instance, exposure to radiofrequency EM fields on sleep architecture show little or no effect. However, a number of studies show that pulsating radiofrequency electromagnetic fields, such as those emitted from cellular phones, can alter brain physiology, increasing the electroencephalogram power in selective bands when administered immediately prior to or during sleep. Additional research is necessary that would include older populations and evaluate the interactions of EM fields in different frequency ranges to examine their effects on sleep in humans.


Assuntos
Campos Eletromagnéticos , Sono/efeitos da radiação , Eletroencefalografia , Humanos , Magnetoterapia , Sono/fisiologia , Transtornos do Sono-Vigília/terapia
2.
J Phys Chem B ; 119(52): 15892-900, 2015 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-26643863

RESUMO

We have measured the quasi-elastic neutron scattering (QENS) of an electrohydrodynamic liquid bridge formed between two beakers of pure water when a high voltage is applied, a setup allowing to investigate water under high-voltage without high currents. From this experiment two proton populations were distinguished: one consisting of protons strongly bound to oxygen atoms (immobile population, elastic component) and a second one of quasi-free protons (mobile population, inelastic component) both detected by QENS. The diffusion coefficient of the quasi-free protons was found to be D = (26 ± 10) × 10(-5) cm(2) s(-1) with a jump length lav ∼ 3 Å and an average residence time of τ0 = 0.55 ± 0.08 ps. The associated proton mobility in the proton channel of the bridge is ∼9.34 × 10(-7) m(2) V(-1) s(-1), twice as fast as diffusion-based proton mobility in bulk water. It also matches the so-called electrohydrodynamic or "apparent" charge mobility, an experimental quantity which so far has lacked molecular interpretation. These results further corroborate the proton channel model for liquid water under high voltage and give new insights into the molecular mechanisms behind electrohydrodynamic charge transport phenomena and delocalization of protons in liquid water.

3.
Int J Environ Res Public Health ; 8(6): 1936-56, 2011 06.
Artigo em Inglês | MEDLINE | ID: mdl-21776211

RESUMO

Prior to major earthquakes many changes in the environment have been documented. Though often subtle and fleeting, these changes are noticeable at the land surface, in water, in the air, and in the ionosphere. Key to understanding these diverse pre-earthquake phenomena has been the discovery that, when tectonic stresses build up in the Earth's crust, highly mobile electronic charge carriers are activated. These charge carriers are defect electrons on the oxygen anion sublattice of silicate minerals, known as positive holes, chemically equivalent to O- in a matrix of O2-. They are remarkable inasmuch as they can flow out of the stressed rock volume and spread into the surrounding unstressed rocks. Travelling fast and far the positive holes cause a range of follow-on reactions when they arrive at the Earth's surface, where they cause air ionization, injecting massive amounts of primarily positive air ions into the lower atmosphere. When they arrive at the rock-water interface, they act as •O radicals, oxidizing water to hydrogen peroxide. Other reactions at the rock-water interface include the oxidation or partial oxidation of dissolved organic compounds, leading to changes of their fluorescence spectra. Some compounds thus formed may be irritants or toxins to certain species of animals. Common toads, Bufo bufo, were observed to exhibit a highly unusual behavior prior to a M6.3 earthquake that hit L'Aquila, Italy, on April 06, 2009: a few days before the seismic event the toads suddenly disappeared from their breeding site in a small lake about 75 km from the epicenter and did not return until after the aftershock series. In this paper we discuss potential changes in groundwater chemistry prior to seismic events and their possible effects on animals.


Assuntos
Comportamento Animal , Terremotos , Água Subterrânea/química , Animais , Previsões
4.
Eye (Lond) ; 19(2): 163-70, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15218517

RESUMO

PURPOSE: To report on visual outcome of patients receiving an intravitreal injection of triamcinolone acetonide as treatment of progressive exudative age-related macular degeneration. METHODS: The prospective comparative nonrandomized clinical interventional study included 187 consecutive patients with progressive exudative age-related macular degeneration, divided into a study group of 115 patients receiving an intravitreal injection of 25 mg triamcinolone acetonide, and a control group of 72 patients without treatment. The mean follow-up was 6.0+/-4.2 months. RESULTS: Visual acuity increased significantly (P=0.03) in the study group, and decreased significantly (P=0.01) in the control group, at 1 month and 3 months after start of the study. Between the study group and control group, the differences in change of visual acuity were significant (P=0.001). In the study group, the number of patients with an increase in visual acuity of 2 or more Snellen lines was significantly (P=0.001) larger than in the control group. Correspondingly, the number of patients with a decrease of 2 or more Snellen lines was significantly (P=0.007) smaller in the study group. In all, 43 (37.4%) patients of the study group experienced an increase in best visual acuity by 2 or more Snellen lines. CONCLUSIONS: Visual acuity increased in patients with exudative age-related macular degeneration at 1 month and 3 months after an intravitreal injection of 25 mg triamcinolone acetonide.


Assuntos
Glucocorticoides/uso terapêutico , Degeneração Macular/tratamento farmacológico , Triancinolona Acetonida/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Anti-Inflamatórios/uso terapêutico , Progressão da Doença , Feminino , Seguimentos , Humanos , Injeções Intralesionais , Pressão Intraocular/efeitos dos fármacos , Degeneração Macular/fisiopatologia , Masculino , Estudos Prospectivos , Resultado do Tratamento , Acuidade Visual/efeitos dos fármacos , Corpo Vítreo
6.
Nucleic Acids Res ; 16(5): 1857-9, 1988 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-3353224

RESUMO

BIONET has made considerable progress in developing communication links among molecular biologists and biochemists worldwide. We describe these efforts and also note the many new enhancements to the BIONET system itself.


Assuntos
Redes de Comunicação de Computadores/métodos , Sistemas Computacionais/métodos , Biologia Molecular/métodos , Sequência de Aminoácidos , Sequência de Bases , Europa (Continente) , Sistemas de Informação , Biologia Molecular/instrumentação , Automação de Escritório , Software , Estados Unidos
7.
Nature ; 309(5970): 719-22, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6547210

RESUMO

Atrial extracts contain factors which induce potent natriuresis changes in renal haemodynamics, and relax pre-contracted vascular smooth muscle. Low-molecular-weight peptides which mimic these actions have now been purified by several groups, including ours (see accompanying paper), and higher-molecular-weight proteins with similar but less potent biological activities have also been identified and are presumed to be precursors. If released into the circulation, these peptides, collectively called atrial natriuretic factor (ANF), may play a significant part in blood-pressure homeostasis, regulation of extracellular fluid volume and as antagonists to the hypertensive effects of the renin-angiotensin system and other hormonal and neurotransmitter systems. We describe here the isolation and characterization of rat atrial cDNA clones which encode ANF. Nucleotide sequence analysis shows that auriculin corresponds to the 25 amino acids located close to the C-terminus of a 152-amino acid ANF precursor. Analysis of the in vitro translation products of precursor ANF mRNA suggests that multiple forms of the precursor may exist.


Assuntos
Clonagem Molecular , DNA/análise , Genes , Coração/fisiologia , Proteínas Musculares/genética , Natriurese , Precursores de Proteínas/genética , Sequência de Aminoácidos , Animais , Função Atrial , Fator Natriurético Atrial , Sequência de Bases , Peso Molecular , Proteínas Musculares/isolamento & purificação , Hibridização de Ácido Nucleico , Biossíntese de Proteínas , Precursores de Proteínas/isolamento & purificação , RNA Mensageiro/genética , Ratos
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