Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 60
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
J Environ Radioact ; 218: 106267, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32421583

RESUMO

We present here the first attempt to understand the fast dynamics of an active basaltic volcano, namely Mt. Etna using soil gas radon measured in some sites located in strategic places around the volcano. Data were measured continuously from July 2015 to February 2017 and the raw signals were treated in order to filter out all possible periodic components that are normally due to non-volcanic factors, applying a method that does not require acquisition of other parameters, which are not always available. The residual signals highlighted seven anomalous changes, with radon values reaching levels from 2 to 5 times higher than the normal background. In six out of seven cases, anomalies were almost contemporaneous in all or almost all of the sites, indicating a common source for the observed radon variations. The pattern of anomalies suggests a transient wave-like propagation in the space/time domain, compatible with pressure-induced displacement of the gas. The observed patterns are most probably caused by the rapid upward motion of gas-rich magma into the volcano conduits, as almost all anomalies precede or accompany major volcanic events. In some cases, an alternative explanation could be the strong and sudden strain releases through earthquakes swarms, with consequent variations in the permeability of rocks at a large scale, given the apparent correlation between those anomalies and intense seismicity.


Assuntos
Monitoramento de Radiação , Radônio , Poluentes Radioativos do Solo , Itália , Solo
3.
Radiat Prot Dosimetry ; 160(1-3): 70-3, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24729558

RESUMO

Although there are many methods for investigating tectonic structures, many faults remain hidden, and they can endanger the life and property of people living along them. The slopes of volcanoes are covered with such hidden faults, near which strong earthquakes and gas releases can appear. Revealing hidden faults can therefore contribute significantly to the protection of people living in volcanic areas. In the study, seven different techniques were used for making measurements of in-soil radon concentrations in order to search for hidden faults on the SE flank of the Mt. Etna volcano. These reported methods had previously been proved to be useful tools for investigating fault structures. The main aim of the experiment presented here was to evaluate the usability of these methods in the geological conditions of the Mt. Etna region, and to find the best place for continual radon monitoring using a permanent station in the near future.


Assuntos
Gases/análise , Sedimentos Geológicos/análise , Monitoramento de Radiação , Radônio/análise , Poluentes Radioativos do Solo/análise , Erupções Vulcânicas , Humanos , Espectrometria gama
4.
Appl Radiat Isot ; 67(1): 178-85, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18986811

RESUMO

Three different methodologies were used to measure Radon ((222)Rn) in soil, based on both passive and active detection system. The first technique consisted of solid-state nuclear track detectors (SSNTD), CR-39 type, and allowed integrated measurements. The second one consisted of a portable device for short time measurements. The last consisted of a continuous measurement device for extended monitoring, placed in selected sites. Soil (222)Rn activity was measured together with soil Thoron ((220)Rn) and soil carbon dioxide (CO(2)) efflux, and it was compared with the content of radionuclides in the rocks. Two different soil-gas horizontal transects were investigated across the Pernicana fault system (NE flank of Mount Etna), from November 2006 to April 2007. The results obtained with the three methodologies are in a general agreement with each other and reflect the tectonic settings of the investigated study area. The lowest (222)Rn values were recorded just on the fault plane, and relatively higher values were recorded a few tens of meters from the fault axis on both of its sides. This pattern could be explained as a dilution effect resulting from high rates of soil CO(2) efflux. Time variations of (222)Rn activity were mostly linked to atmospheric influences, whereas no significant correlation with the volcanic activity was observed. In order to further investigate regional radon distributions, spot measurements were made to identify sites having high Rn emissions that could subsequently be monitored for temporal radon variations. SSNTD measurements allow for extended-duration monitoring of a relatively large number of sites, although with some loss of temporal resolution due to their long integration time. Continuous monitoring probes are optimal for detailed time monitoring, but because of their expense, they can best be used to complement the information acquired with SSNTD in a network of monitored sites.


Assuntos
Radônio/análise , Solo/análise , Terremotos , Itália , Métodos
5.
Eur Respir J ; 26(3): 398-405, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16135719

RESUMO

The leptin-leptin receptor system might be up-regulated in the airways of chronic obstructive pulmonary disease (COPD). In bronchial biopsies obtained from normal subjects and smokers, with and without COPD, the present study examined leptin and leptin-receptor expression and their co-localisation in airway and inflammatory cells. Combining immunohistochemistry with terminal deoxynucleotidyl transferase dUTP nick end-labelling techniques, apoptosis in airway and inflammatory cells and in leptin and leptin-receptor expressing cells was investigated. In the epithelial cells both leptin and leptin-receptor expression was higher in normal subjects than in smokers and COPD subjects. By contrast, in the sub-mucosa, leptin was over-expressed in COPD when compared with normal subjects and smokers. Leptin and its receptor were co-localised, mainly with activated T cells (CD45R0) and CD8+ T lymphocytes. In smokers, apoptosis was found in some inflammatory cells, whereas in COPD inflammatory cells, leptin and leptin-receptor positive cells were not apoptotic. Leptin expression was related to COPD severity and assessed using the Global initiative for Chronic Obstructive Lung Disease classification. In conclusion, the present study shows an increased leptin expression in bronchial mucosa of chronic obstructive pulmonary disease patients, associated with airway inflammation and airflow obstruction.


Assuntos
Brônquios/metabolismo , Leptina/metabolismo , Doença Pulmonar Obstrutiva Crônica/metabolismo , Receptores de Superfície Celular/metabolismo , Mucosa Respiratória/metabolismo , Fumar/metabolismo , Adulto , Idoso , Apoptose/fisiologia , Brônquios/patologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/patologia , Receptores para Leptina , Testes de Função Respiratória , Mucosa Respiratória/patologia , Linfócitos T/fisiologia
6.
Panminerva Med ; 47(4): 245-57, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16489323

RESUMO

Polyunsaturated fatty acids (PUFAs) have an important role in human diet, both for the prevention and the therapy of different pathologies. In this review, a critical evaluation of PUFAs dietary sources and biological functions in human organism has been done. In particular, the efficacy of omega-3 fatty acids in the improvement of the lipidic pattern and in the excitability of myocardium has been analyzed, and, therefore, their usefulness in the prevention of cardiovascular diseases and postinfarction arrhythmias. As PUFAs are precursors of prostaglandins and leucotriens, which are involved in phlogosis and immune response, a diet rich in fish oil reduces the production of PGE2 involved in many phlogosis events. Moreover, an increase in the eicosapentaenoic acid (EPA) intake leads to a reduction in the production of inflammatory cytokines (interleukin 1, 2, 6 and tumor necrosis factor); so, it is important to use omega-3 in chronic inflammatory diseases, as the rheumatoid arthritis. It seems that omega-3 could prevent the onset of hormone-dependent tumours (i.e. breast and prostatic cancer); in vitro observations, in fact, have shown that the PG of the series 2, derived from omega-6, have a carcinogenic action; instead, the anticancer effect of omega-3 could derive from their effect in antagonizing the formation of such PG; it can be useful, therefore, to increase the dietary omega-3/omega-6 ratio. Moreover, the effects of omega-3 on the anatomic and functional central nervous system development and of their possible therapeutical use in some psychiatric pathologies were evaluated.


Assuntos
Ácidos Graxos Ômega-3/farmacologia , Antialérgicos/farmacologia , Anti-Inflamatórios/farmacologia , Anti-Hipertensivos/farmacologia , Gorduras Insaturadas na Dieta/administração & dosagem , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/uso terapêutico , Ácidos Graxos Insaturados/classificação , Ácidos Graxos Insaturados/fisiologia , Humanos , Neoplasias/prevenção & controle , Sistema Nervoso/efeitos dos fármacos , Sistema Nervoso/embriologia
7.
Arch Physiol Biochem ; 105(5): 445-9, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9439781

RESUMO

Cerebral serotonin level influences luteinizing hormone release and, consequently, ovulation. The present study evaluated the effects of precooked maize meal (polenta), a diet almost devoid of tryptophan the serotonin precursor on the alterations of the estrus cycle as measured by vaginal smears analysis in Wistar rats. Several conditions of environmental lighting were used in order to modify ovarian cycle: 1) natural alternating light/dark cycle; 2) continuous darkness; 3) continuous light by sodium steams: 4) continuous light by fluorescent neon tubes. Rats bred in continuous lighting showed estrus-proestrus rate significantly greater than rats bred in normal lighting or in continuous darkness. The feeding with precooked maize meal suppressed persistent estrus in rats bred in continuous lighting, and significantly cut down the estrus-proestrus frequency in any condition of environmental lighting. Our results lead to hypothesize that polenta diet, for its low tryptophan content, cutting down both tryptophan plasma content and serotonin neuronal synthesis, promotes luteinizing hormone peak.


Assuntos
Dieta , Estro/fisiologia , Iluminação/efeitos adversos , Triptofano/deficiência , Animais , Anovulação/etiologia , Anovulação/fisiopatologia , Escuridão , Estro/efeitos da radiação , Feminino , Ratos , Ratos Wistar , Zea mays
8.
In. Spagna, Valerio, ed; Schiavon, Enrico, ed. Scientific meeting on the Seismic Protection : Proceedings. Venezia, Italia. Regione del Veneto. Dipartimento per la Geologia e le Attivita Estrattive, 1993. p.176-84, ilus, tab.
Monografia em En | Desastres | ID: des-7821

RESUMO

The results of the investigations show interesting correlations between gases in the soils and in the waters (CO2-Rn) and changes in the chemical composition of the natural gas exhalations (He, CH4) probably related to the earthquake. The geochemical surveys allowed us to define the most interesting areas for seismic monitoring aimed at earthquake prediction.(AU)


Assuntos
Terremotos , Pesquisa , Itália , Elementos Radioativos , Gases
9.
Arch Int Physiol Biochim ; 98(1): 19-21, 1990 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1692689

RESUMO

Effects of different conditions of environmental lighting on the appearance of the muricidal behaviour in male Wistar rats have been studied. The animals were kept under different conditions of environmental lighting: 1) natural day light alternated with the dark of the night; 2) sodium, continuous light emitted by a sodium steam lamp; 3) neon, continuous light emitted by fluorescent neon tubes. The continuous sodium steam light increased the percentage of animals becoming muricide when compared to animals bred in a natural environment with a normal succession of day-night lighting. On the contrary, this percentage decreased if the rats of the same group are exposed to continuous light emitted by fluorescent neon tubes. As the exposure of rats to an environment under continuous light causes a reduction of the cerebral content of serotonin, the muricidal behaviour provoked in naturally non-muricide rats by this type of lighting could be related to this depletion.


Assuntos
Agressão , Comportamento Agonístico , Iluminação , Animais , Masculino , Camundongos , Ratos , Ratos Endogâmicos
10.
Arch Int Physiol Biochim ; 98(1): 23-6, 1990 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1692690

RESUMO

The content of tryptophan in a precooked corn meal and in 4 types of selected corn seeds: Zea mays indurata, identata, opaque/2 and Marano synth., has been determined by three different methods: ion-exchange chromatography, spectrofluorometry and spectrophotometry. This content is very low, less than 0.080% d.w. Alimentation for 4 d with a diet composed of precooked corn meal with a tryptophan content less than 0.025% induced the appearance of aggressive-cidal or aggressive non-cidal behaviour towards the mouse in more than half of Wistar rats bred in a room constantly lighted by a sodium steam light. The appearance of this behaviour is probably connected with a decrease in brain serotonin.


Assuntos
Agressão , Dieta , Triptofano/deficiência , Zea mays/análise , Animais , Masculino , Camundongos , Ratos , Ratos Endogâmicos , Fatores de Tempo , Triptofano/análise
11.
Boll Soc Ital Biol Sper ; 65(3): 211-7, 1989 Mar.
Artigo em Italiano | MEDLINE | ID: mdl-2765243

RESUMO

The aim of this research is to study the effects of different modalities of environment lighting on the appearance of the muricide behaviour in the Wistar male Rat. Indeed it is known that the exposition of Rats in environment to continuous light determine a reduction of the cerebral content of serotonin, which is known to unchain the muricide behaviour in naturally not muricide Rats. The animals are kept in different situations of environment lighting: 1) L/D = the natural light of the day alternated with the dark of the night; 2) L/L sodium = continuous light emitted by a sodium steam lamp; 3) L/L neon = continuous light issued from fluorescent neon tubes. The muricide behaviour is studied by comparison Rat-Mouse. The results obtained show that the continuous sodium steam light (L/L, sodium) remarkably increase the percentage of the animals which become muricide compared to the control animals bred in natural environment with a normal succession day-night (L/D). On the contrary the percentage is remarkably reduced compared to the control animals in Rats of the same group when these animals are exposed to continuous light issued from fluorescent neon tubes (L/L, neon).


Assuntos
Agressão/efeitos da radiação , Comportamento Animal/efeitos da radiação , Iluminação/efeitos adversos , Animais , Iluminação/métodos , Masculino , Ratos , Ratos Endogâmicos , Fatores de Tempo
12.
Boll Soc Ital Biol Sper ; 65(3): 219-26, 1989 Mar.
Artigo em Italiano | MEDLINE | ID: mdl-2765244

RESUMO

The aim of this research is to observe if the lack of cerebral serotonin, obtained by a diet almost devoid of tryptophan (precooked yellow corn meal) is able to trigger the muricide behaviour in male Rats naturally non-muricide. To determine the tryptophan content in the food used and in 4 types of selected maize flour (Zea mays: indurata, indentata, opaque/2 and synt. marano), 3 different methods have been used (ion-exchange chromatography, spectrofluorometry, spectrophotometry). The muricide behaviour, or the interspecific attack, has been tested by comparison Rat-Mouse. The results show that the feeding with a diet "short term" (4 days), composed of precooked corn meal, with a very low content of tryptophan, induces the appearance of muricide or aggressive behaviour towards the Mouse in more than half of the Wistar Rats, bred in a room constantly lighted by sodium steam light. The appearance of the above-mentioned behaviour is connected with the decrease in cerebral serotonin.


Assuntos
Agressão/fisiologia , Comportamento Animal/fisiologia , Dieta , Farinha , Animais , Masculino , Camundongos , Ratos , Ratos Endogâmicos , Fatores de Tempo , Triptofano/fisiologia , Zea mays
13.
Boll Soc Ital Biol Sper ; 65(3): 227-33, 1989 Mar.
Artigo em Italiano | MEDLINE | ID: mdl-2765245

RESUMO

The aim of this research is to study the effects of a diet almost devoid of tryptophan, which is given by a feeding with precooked yellow corn meal (corn mush), on the alterations of the estrous cycle of animals in several conditions of environmental lighting. Indeed, it is known that cerebral serotonin influences the releasing of LH and consequently the ovulation. The different types of environmental lighting are: 1) Natural (alternating Day-Night = L/D). 2) Continuous dark (D/D). 3) Continuous light by sodium steams (L/L sodium). 4) Continuous light by fluorescent neon tubes (L/L neon). The muricide behaviour is studied by comparison rat-mouse. The feeding with precooked yellow corn meal (diet lacking of tryptophan) unchains in the 100% of the observations the CEA (Constant Estrous Anovulatory), and significantly shrinks the estral cycle in the female Wistar Rat in several conditions of environmental lighting.


Assuntos
Dieta , Estro/fisiologia , Farinha , Iluminação , Animais , Ritmo Circadiano , Feminino , Ratos , Ratos Endogâmicos , Fatores de Tempo , Zea mays
16.
Arch Int Physiol Biochim ; 87(5): 943-7, 1979 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-94825

RESUMO

The results we have got on the mouse-killing behaviour of the rat point out the remarkable percentage difference between control males and control females, between integral males and males castrated at birth, and between normal females and females under the effects of androgens. Such results make us believe that the appearance of the killer behaviour is affected by the presence of testosterone in the first days of life of the rat.


Assuntos
Agressão/efeitos dos fármacos , Castração , Testosterona/farmacologia , Animais , Animais Recém-Nascidos , Feminino , Humanos , Masculino , Camundongos , Ratos , Fatores Sexuais
17.
Arch Int Physiol Biochim ; 87(5): 949-53, 1979 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-94826

RESUMO

Data demonstrate exactly that testosterone favour above all the killing behaviour of castrate males at birth in comparison with control males while ciproterone acetate turns out to be more effective in diminishing the killing behaviour of males having integral testicle and of androgenized females at birth in comparison with castrated males. The results point out that the killing behaviour of rats is affected by the presence of testosterone in the first days of life, and in the grown-up animal.


Assuntos
Agressão/efeitos dos fármacos , Ciproterona/farmacologia , Testosterona/farmacologia , Animais , Castração , Feminino , Humanos , Masculino , Camundongos , Ratos , Fatores Sexuais
18.
Boll Soc Ital Biol Sper ; 55(9): 854-9, 1979 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-553609

RESUMO

We have developed a project for biological radio-controlled electrostimulation, consisting in a three channel telestimulator, which has been used in our laboratories on animals unrestrained and complete freedom of movements. The system has been tested and used in many experiments which excellent results.


Assuntos
Encéfalo/fisiologia , Rádio/instrumentação , Animais , Gatos , Estimulação Elétrica/instrumentação
19.
Boll Soc Ital Biol Sper ; 55(9): 860-5, 1979 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-553610

RESUMO

Our purpose in this work has been to carry out experiment of electric stimulation of the dorsal hippocampus, by measuring exactly the quantity of stimulating current, expressed in mA, in order to ascertain the actual quantities of electric charges, expressed in microcoulombs and conveyed to the examined structure and able to cause "an after discharge". the optimum stimulation frequency involving supply of the lowest quantity of electric charges and such frequency is more or less equal to the frequency of discharge of the paroxysmal bioelectric activity (about 20 c/sec). The optimum length of the train of stimulation is very short, but non shorter than 1 sec; consequently the length of the train of stimuli of 2, 5 sec, corresponding to a current intensity inferior to 1 mA and to a sufficiently low quantity fo charges, is to be regarded as the optimum length. The optimum length of the single stimulus is very short too, but it cannot be too short, since, also in this case, the intensity of current necessary to reach the threshold for the "after discharge" would reach such values as to cause lesions in the stimulated structure; consequently the length of the single stimulus corresponding to 0, 4 msec is to be considered as to optimum length.


Assuntos
Estimulação Elétrica/métodos , Hipocampo/fisiologia , Animais , Eletrodos Implantados , Coelhos
20.
Boll Soc Ital Biol Sper ; 55(9): 866-70, 1979 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-553611

RESUMO

The 20% of male 5-6 month-old Wistar rats SM prove to be natural killers. A four-month long insulation of "surely non-killer" rats has not allowed to notice a mouse-killing behaviour in any animal. The total bilateral removal of olfactory bulbs in "non-killer rats" causes a "mouse-killing behaviour" in all the animal 24 hours after the operation, but with a latency of response that has proved different in the various rats. Precisely, while 24 hours and 15 days after the bulb operation the rats can be distinguished into "rapid killers" and "slow killers", after 30 days all the animals become "rapid killers" with a remarkably shortened period of mouse-killing latency (1 - 60 seconds).


Assuntos
Agressão/fisiologia , Bulbo Olfatório/fisiologia , Animais , Humanos , Camundongos , Ratos , Isolamento Social , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...