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1.
Chemistry ; 24(25): 6564-6571, 2018 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-29447431

RESUMO

The hydrogen bonds involving sulfur in the furfuryl mercaptan monohydrate are compared with the interactions originating from the hydroxyl group in furfuryl alcohol. The dimers with water were created in a supersonic jet expansion and characterized using microwave spectroscopy and supporting molecular orbital calculations. In furfuryl alcohol-water, a single isomer is observed, in which the water molecule forms an insertion complex with two simultaneous hydrogen bonds to the alcohol (O-H⋅⋅⋅Ow ) and the ring oxygen (Ow -H⋅⋅⋅Or ). When the alcohol is replaced by a thiol group in furfuryl mercaptan-water, two isomers are observed, with the thiol group preferentially behaving as proton donor to water. The first isomer is topologically equivalent to the alcohol analog but the stronger hydrogen bond is now established by water and the ring oxygen, assisted by a thiol S-H⋅⋅⋅Ow hydrogen bond. In the second isomer the sulfur group accepts a proton from water, forming a Ow -H⋅⋅⋅S hydrogen bond. Binding energies for the mercaptan-water dimer are predicted around 12 kJ mol-1 weaker than in the alcohol hydrate (B3LYP-D3(BJ)). The non-covalent interactions in the furfuryl dimers are dominantly electrostatic according to a SAPT(0) energy decomposition, but with increasing dispersion components in the mercaptan dimers, which are larger for the isomer with the weaker Ow -H⋅⋅⋅S interaction.

2.
Viruses ; 16(1)2024 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-38257787

RESUMO

The introduction of three single nucleotide mutations into the genome of the virulent RVFV ZH548 strain allows for the rescue of a fully attenuated virus in mice (ZH548-rA2). These mutations are located in the viral genes encoding the RdRp and the non-structural protein NSs. This paper shows the results obtained after the subcutaneous inoculation of ZH548-rA2 in adult sheep and the subsequent challenge with the parental virus (ZH548-rC1). Inoculation with the ZH548-rA2 virus caused no detectable clinical or pathological effect in sheep, whereas inoculation of the parental rC1 virus caused lesions compatible with viral infection characterised by the presence of scattered hepatic necrosis. Viral infection was confirmed via immunohistochemistry, with hepatocytes within the necrotic foci appearing as the main cells immunolabelled against viral antigen. Furthermore, the inoculation of sheep with the rA2 virus prevented the liver damage expected after rC1 virus inoculation, suggesting a protective efficacy in sheep which correlated with the induction of both humoral and cell-mediated immune responses.


Assuntos
Vírus da Febre do Vale do Rift , Viroses , Animais , Camundongos , Ovinos , Vírus da Febre do Vale do Rift/genética , Antígenos Virais , Genes Virais , Hepatócitos
3.
Anal Chim Acta ; 1209: 339003, 2022 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-35569840

RESUMO

The 2020s could be called, with little doubt, the "Mars decade". No other period in space exploration history has experienced such interest in placing orbiters, rovers and landers on the Red Planet. In 2021 alone, the Emirates' first Mars Mission (the Hope orbiter), the Chinese Tianwen-1 mission (orbiter, lander and rover), and NASA's Mars 2020 Perseverance rover reached Mars. The ExoMars mission Rosalind Franklin rover is scheduled for launch in 2022. Beyond that, several other missions are proposed or under development. Among these, MMX to Phobos and the very important Mars Sample Return can be cited. One of the key mission objectives of the Mars 2020 and ExoMars 2022 missions is the detection of traces of potential past or present life. This detection relies to a great extent on the analytical results provided by complementary spectroscopic techniques. The development of these novel instruments has been carried out in step with the analytical study of terrestrial analogue sites and materials, which serve to test the scientific capabilities of spectroscopic prototypes while providing crucial information to better understand the geological processes that could have occurred on Mars. Being directly involved in the development of three of the first Raman spectrometers to be validated for space exploration missions (Mars 2020/SuperCam, ExoMars/RLS and RAX/MMX), the present review summarizes some of the most relevant spectroscopy-based analyses of terrestrial analogues carried out over the past two decades. Therefore, the present work describes the analytical results gathered from the study of some of the most distinctive terrestrial analogues of Martian geological contexts, as well as the lessons learned mainly from ExoMars mission simulations conducted at representative analogue sites. Learning from the experience gained in the described studies, a general overview of the scientific outcome expected from the spectroscopic system developed for current and forthcoming planetary missions is provided.


Assuntos
Marte , Voo Espacial , Meio Ambiente Extraterreno/química , Análise Espectral Raman/métodos
4.
Radiat Prot Dosimetry ; 153(4): 485-95, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22807496

RESUMO

This paper is a study of the radiological impact of a coal-fired power plant in Spain. Activity concentrations of six natural radionuclides were determined in coal, ash, mine wastes and sediments by gamma-ray spectrometry. The average activity concentrations of (238)U, (226)Ra, (224)Ra, (210)Pb, (232)Th and (40)K in coal were 24, 30, 28, 41, 23 and 242 Bq kg(-1)  and in ash were 103, 128, 101, 124, 88 and 860 Bq kg(-1), respectively. The enrichment factor, radium equivalent activity and alpha index in the ash sample have been estimated. For the five waste pile samples, the absorbed dose rate was higher than the world average dose rate (60 nGy h(-1)). The dependence of radionuclide concentration on the grain size of nine sediments was also studied. The analysis of the radionuclides in waste and sediment samples will demonstrate the distribution and mobility of these elements through the environment, where a potential risk of contamination can be detected.


Assuntos
Centrais Elétricas , Radioisótopos/análise , Poluentes Radioativos do Solo/análise , Absorção , Carvão Mineral/análise , Meio Ambiente , Geografia , Sedimentos Geológicos , Radioisótopos de Chumbo/análise , Radioisótopos de Potássio/análise , Doses de Radiação , Monitoramento de Radiação/métodos , Rádio (Elemento)/análise , Espanha , Espectrometria gama/métodos , Tório/análise , Urânio/análise
5.
Chemosphere ; 90(2): 488-96, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22967929

RESUMO

The study of the vertical distribution of seven radionuclides in soils around a coal fired power plant in a mountain region in the north of Spain has been performed, in order to know if some deposition and migration of these radionuclides has taken place. Thirteen profiles of 30 cm depth have been selected, and every fraction of 5 cm has been analyzed until of a total of 72 soil samples. The activity concentration of (238)U, (226)Ra, (210)Pb, (232)Th, (224)Ra, (40)K and (137)Cs has been measured by gamma-ray spectrometry. The data were analyzed using multivariate statistical techniques, founding the best result when using a simple two-factor model, which can explain the 81.1% of the total variance. Additionally, on the basis of the significant differences found in the concentration of lead in the soil top and deep layers, the evaluation of excess of (210)Pb and the K-parameter was done. A good correlation between the excess of (210)Pb and the concentration of anthropogenic radionuclide (137)Cs in surface soil was found. These results confirm the atmospheric deposition of lead as a decay product of exhaled Rn.


Assuntos
Centrais Elétricas , Monitoramento de Radiação , Radioisótopos/análise , Poluentes Radioativos do Solo/análise , Solo/química , Carvão Mineral , Espanha
6.
J Environ Radioact ; 124: 84-92, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23680923

RESUMO

Coal-fired power-plants (CFPP) can be a source of contamination because the coal contains trace amounts of natural radionuclides, such as (40)K and (238)U, (232)Th and their decay products. These radionuclides can be released as fly ash from the CFPP and deposited from the atmosphere on the nearby top soils, therefore modifying the natural radioactivity background levels, and subsequently increasing the total radioactive dose received for the nearby population. In this paper, an area of 64 km(2) around the CFPP of Velilla del Río Carrión (Spain) has been studied by collecting 67 surface soil samples and measuring the activities of one artificial and six natural radionuclides by gamma spectrometry. The found results are similar to the background natural levels and ranged from 0 to 209 for (137)Cs, 11 to 50 for (238)U, 14 to 67 for (226)Ra, 29 to 380 for (210)Pb, 15 to 68 for (232)Th, 17 to 78 for (224)Ra, 97 to 790 for (40)K (all values in Bq kg(-1)). Besides the classical radiochemical tools, Analysis of Variance (ANOVA), Principal Component Analysis (PCA), Hierarchical Clustering Analysis (HCA), and kriging mapping have been used to the experimental dataset, allowing us to find the existence of two different models of spatial distribution around the CFPP. The first, followed by (238)U, (226)Ra, (232)Th, (224)Ra and (40)K can be assigned to 'natural background radioactivity', whereas the second model, followed by (210)Pb and (137)Cs, is based on 'atmospheric fallout radioactivity'. The main conclusion of this work is that CFPP has not influence on the radioactivity levels measured in the studied area, with has a mean annual outdoor effective dose E = 71 ± 22 µSv, very close to the average UNSCEAR value of 70 µSv, thus confirming the almost non-existent radioactive risk posed by the presence of the CFPP.


Assuntos
Centrais Elétricas , Radioisótopos/análise , Poluentes Radioativos do Solo/análise , Análise de Variância , Análise por Conglomerados , Carvão Mineral , Humanos , Análise de Componente Principal , Doses de Radiação , Monitoramento de Radiação/estatística & dados numéricos , Medição de Risco , Espanha , Análise Espacial
7.
Horiz. enferm ; 4(1): 40-1, 1993.
Artigo em Espanhol | LILACS, BDENF | ID: lil-140867

RESUMO

Este artículo pretende presentar una visión general a nivel personal, colectivo y formativo del presente y futuro de enfermería en nuestro país


Assuntos
Currículo/tendências , Enfermagem , Escolas de Enfermagem , Espanha
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