Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Talanta ; 271: 125639, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38219327

RESUMO

Moonmilk-type deposits exemplify carbonated Martian analogues existing in the subsurface of Earth, an endokarstic speleothem with a possible biochemical origin composed principally by carbonates, mainly huntite and dolomite. In this work, samples of moonmilk located in Nerja Cave (southern Spain) have been studied by LIBS with the aim of identifying carbon of biogenic origin by establishing a relationship between a molecular emission indicator, CN signal, and the organic carbon content. The characterization of this kind of carbonate deposit with a multiple mineralogical composition has been completed using scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction techniques for qualitative and semi-quantitative analysis. The information attained from LIBS regarding energy thresholds and time-resolved kinetics of CN emissions provides useful insight into the identification of different molecular emitters, namely organic and inorganic CN, depending on the laser irradiance and time settings conditions. These promising results are of application in the search and identification of biosignatures in upcoming planetary missions with astrobiological purposes.

2.
Sci Total Environ ; 883: 163693, 2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37100125

RESUMO

Following the declaration of the COVID-19 pandemic, the Spanish Government restricted non-essential movements of all citizens and closed all public spaces, such as the Nerja Cave, until May 31, 2020. This particular condition of the closure of the cave provided a unique opportunity to study the micro-climate conditions and carbonate precipitation in this tourist cave without the presence of visitors. Our results show the significant effect of visitors on the air isotopic signature of the cave and on the genesis of the extensive dissolution features affecting the carbonate crystals formed in the tourist sector of the cave, alerting us to the possible corrosion of the speleothems located there. The movement of visitors within the cave also favours the mobilisation of aerial fungi and bacterial spores and their subsequent sedimentation simultaneously with the abiotic precipitation of carbonates from the drip water. The traces of these biotic elements could be the origin of the micro-perforations previously described in the carbonate crystals formed in the tourist galleries of the cave, but they are subsequently enlarged due to abiotic dissolution of the carbonates through these weaker zones.


Assuntos
COVID-19 , Pandemias , Humanos , Espanha , Efeitos Antropogênicos , COVID-19/epidemiologia , Cavernas , Carbonatos/química
3.
Sci Total Environ ; 730: 139147, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32417530

RESUMO

Microclimate and geophysical studies are commonly applied to the characterization of karst systems although they are usually used separately. The main purpose of this manuscript is to show how the analysis of the data from both these research methods is a useful tool in the characterization of karst systems and we present the analysis of a specific case study: the Nerja- Pintada caves system. The joint analysis of the Nerja Cave and external air data (mainly temperatures) and the pre-existing gravimetric data of its surroundings (residual gravity anomaly map) have allowed us: 1) to postulate the existence of an unknown great cavity located near to the Nerja Cave and with direct influence in its ventilation and 2) to propose a new model of the Nerja-Pintada caves ventilation based on the changing connection between a "main cavity" system (Nerja Cave), with basically a transmissive function of airflows and an "annex cavities" sub-system, with different functioning as far as the airflow is concerned: transmissive in the case of Pintada Cave and capacitive in the case of the geophysically-located cave.

4.
Sci Total Environ ; 631-632: 1268-1278, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29727951

RESUMO

This study shows the utilization of the air CO2 exhaled by a very high number of visitors in the Nerja Cave as both a tracer and an additional tool to precisely evaluate the air circulation through the entire karst system, which includes non-touristic passages, originally free of anthropogenic CO2. The analysis of the temporal - spatial evolution of the CO2 content and other monitoring data measured from January 2015 to December 2016 in the Nerja-Pintada system, including air microbiological controls, has allowed us to define a new general ventilation model, of great interest for the conservation of the subterranean environment. During the annual cycle four different ventilation regimes and two ventilation modes (UAF-mode and DAF-mode) exist which determine the significance of the anthropogenic impact within the caves. During the winter regime, the strong ventilation regime and the airflow directions from the lowest to the highest entrance (UAF-mode) contribute to the rapid elimination of anthropogenic CO2, and this affects the whole karstic system. During the summer regime the DAF-mode ventilation (with airflows from the highest to the lowest entrances) is activated. Although the number of visitors is maximum and the natural ventilation of the karstic system is the lowest of the annual cycle, the anthropogenic impact only affects the Tourist Galleries. The transitional ventilation regimes -spring and autumn- are the most complex of the annual cycle, with changing air-flow directions (from UAF-mode to DAF-mode and vice versa) at diurnal and poly diurnal scale, which conditions the range of the anthropogenic impact in each sector of the karst system. The activation of the DAF-mode has been observed when the temperature difference between the external and air cave is higher than 5°C.

5.
Pain ; 153(7): 1382-1389, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22465047

RESUMO

Functional defects in growth hormone (GH) secretion and its efficacy as a complementary treatment have been suggested for fibromyalgia. This study investigated the efficacy and safety of low-dose GH as an add-on therapy in patients with both severe FM and low insulin-like growth factor 1 levels. A total of 120 patients were enrolled in a multicenter, placebo-controlled study for 18 months. They were randomly assigned to receive either 0.006 mg/kg/day of GH subcutaneously (group A, n=60) or placebo (group B, n=60) for 6 months (blind phase). The placebo arm was switched to GH treatment from month 6 to month 12 (open phase), and a follow-up period after GH discontinuation was performed until month 18. Standard treatment for fibromyalgia (selective serotonin re-uptake inhibitors, opioids, and amitriptyline) was maintained throughout the study. Number and intensity of tender points, Fibromyalgia Impact Questionnaire (FIQ) with its subscales, and EuroQol 5 dimensions test (EQ5D) with visual analogue scale (VAS) were assessed at different time points. At the end of the study, 53% of group A patients obtained fewer than 11 positive tender points, vs 33% of group B patients (P<.05). 39.1% vs 22.4% reached more than 50% improvement in VAS (P<.05). Group A patients showed significantly improved FIQ scores (P=.01) compared with group B. Although GH discontinuation worsened all scores in both groups during follow-up, impairment in pain perception was less pronounced in the GH-treated group (P=.05). In this largest and longest placebo-controlled trial performed in FM (NCT00933686), addition of GH to the standard treatment is effective in reducing pain, showing sustained action over time.


Assuntos
Fibromialgia/tratamento farmacológico , Hormônio do Crescimento/uso terapêutico , Dor/tratamento farmacológico , Qualidade de Vida , Adulto , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Medição da Dor , Resultado do Tratamento , Adulto Jovem
6.
Eur J Contracept Reprod Health Care ; 8(4): 225-8, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15006270

RESUMO

Reports of ectopic gestation after failure of emergency contraceptive pills have thus far been rare, although the use of various types of emergency contraceptive pills is becoming more and more popular world-wide. We report two cases of ectopic gestation following failure of levonorgestrel as over-the-counter emergency contraceptive pills. The women personally purchased the pills over-the-counter at a drugstore and took them routinely. Clinicians should be aware of the possibility of an ectopic gestation when an emergency contraceptive pill fails. We recommend to women the full use of established service networks to enhance education and dissemination of information on emergency contraception. Additionally, health providers should advise women very clearly that, if treatment fails, pregnancy could occur, including ectopic gestation.


Assuntos
Anticoncepcionais Sintéticos Pós-Coito/efeitos adversos , Anticoncepcionais Pós-Coito , Levanogestrel/efeitos adversos , Gravidez Tubária/etiologia , Aborto Induzido , Adulto , Anticoncepcionais Sintéticos Pós-Coito/administração & dosagem , Feminino , Seguimentos , Humanos , Levanogestrel/administração & dosagem , Gravidez , Gravidez Tubária/terapia , Medição de Risco
7.
Artigo em Inglês | MEDLINE | ID: mdl-8066097

RESUMO

Prostaglandin (PG) dehydrogenase inactivates PGs by oxidising the 15-hydroxyl group and thus plays a key role in controlling their effective local concentrations. This enzyme is thought to be under the control of steroid hormones and is found in human endometrium at high levels in the secretory phase of the menstrual cycle but is absent during the proliferative phase. We have examined the PG dehydrogenase activity in human endometrium from women who had been treated with the anti-oestrogen clomiphene at an earlier stage of the cycle and found high levels of the enzyme in the proliferative phase. This data was supported by the culture of endometrium from clomiphene treated women which showed both high PG production and extensive inactivation comparable to that seen in the secretory phase. This effect of clomiphene on the PG inactivating ability of endometrium could be of clinical use in management of disorders where elevated PGs are present.


Assuntos
Clomifeno/farmacologia , Endométrio/efeitos dos fármacos , Endométrio/metabolismo , Antagonistas de Prostaglandina/metabolismo , Adulto , Técnicas de Cultura , Indução Enzimática/efeitos dos fármacos , Feminino , Fase Folicular/metabolismo , Humanos , Hidroxiprostaglandina Desidrogenases/biossíntese , Fase Luteal/metabolismo , Prostaglandinas E/metabolismo , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA