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1.
Nat Commun ; 14(1): 4536, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37669984

RESUMO

Classical novae are thermonuclear explosions in stellar binary systems, and important sources of 26Al and 22Na. While γ rays from the decay of the former radioisotope have been observed throughout the Galaxy, 22Na remains untraceable. Its half-life (2.6 yr) would allow the observation of its 1.275 MeV γ-ray line from a cosmic source. However, the prediction of such an observation requires good knowledge of its nucleosynthesis. The 22Na(p, γ)23Mg reaction remains the only source of large uncertainty about the amount of 22Na ejected. Its rate is dominated by a single resonance on the short-lived state at 7785.0(7) keV in 23Mg. Here, we propose a combined analysis of particle-particle correlations and velocity-difference profiles to measure femtosecond nuclear lifetimes. The application of this method to the study of the 23Mg states, places strong limits on the amount of 22Na produced in novae and constrains its detectability with future space-borne observatories.

2.
Appl Radiat Isot ; 166: 109397, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33091860
3.
Oncotarget ; 7(22): 31723-37, 2016 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-27166270

RESUMO

Current larynx preservation treatments have achieved an improvement of laryngoesophageal dysfunction-free survival (LDS) but lead to significant toxicities and recurrences. At present, there is no evidence to select the group of patients that may benefit from preservation approaches instead of surgery. Therefore, laryngeal biomarkers could facilitate pretreatment identification of patients who could respond to chemoradiation-based therapy. In this study, we evaluated retrospectively 53 patients with larynx cancer to determine whether gH2AX phosphorylation (pH2AX) alone or in combination with the membrane protein MAP17 (PDZK1IP1) could be used as prognostic biomarkers. We also evaluated whether the completion of cisplatin treatment and radiotherapy could predict survival in combination with pH2AX.We found that the dose of cisplatin received but not the length of the radiotherapy influenced LDS. High-pH2AX expression was associated with prolonged LDS (HR 0.26, p = 0.02) while MAP17 correlated with overall survival (OS) (HR 0.98, p = 0.05). High-MAP17 and high-pH2AX combined analysis showed improved LDS (with 61.35 months vs 32.2 months, p = 0.05) and OS (with 66.6 months vs 39.8 months, p = 0.01). Furthermore, the subgroup of high-pH2AX and optimal dose of cisplatin was also associated with OS (72 months vs 38.6 months, p = 0.03) and LDS (66.9 months vs 27 months, p = 0.017). These findings suggest that pH2AX alone or better in combination with MAP17 may become a novel and valuable prognostic biomarker for patients with laryngeal carcinoma treated with preservation approaches.


Assuntos
Biomarcadores Tumorais/análise , Carcinoma de Células Escamosas/química , Carcinoma de Células Escamosas/terapia , Quimiorradioterapia , Neoplasias de Cabeça e Pescoço/química , Neoplasias de Cabeça e Pescoço/terapia , Histonas/análise , Neoplasias Laríngeas/química , Neoplasias Laríngeas/terapia , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/secundário , Quimiorradioterapia/efeitos adversos , Quimiorradioterapia/mortalidade , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Progressão da Doença , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Feminino , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Estimativa de Kaplan-Meier , Antígeno Ki-67/análise , Neoplasias Laríngeas/mortalidade , Neoplasias Laríngeas/patologia , Masculino , Proteínas de Membrana/análise , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Fosforilação , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Carcinoma de Células Escamosas de Cabeça e Pescoço , Fatores de Tempo , Resultado do Tratamento , Proteína Supressora de Tumor p53/análise
4.
Food Chem Toxicol ; 50(9): 3234-42, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22735498

RESUMO

Gamma radiation has been used as a post-harvest food preservation process for many years. Chestnuts are a seasonal product consumed fresh or processed, and gamma irradiation emerged recently as a possible alternative technology for their post-harvest processing, to fulfil the requirements of international phytosanitary trade laws. After harvest and storage, several problems may occur, such as the presence of infestations and development of microorganisms, namely rotting and fungi. These diminish the quality and safety of the product, decreasing the yield along the production chain. In fruits, gamma irradiation treatment is for two main purposes: conservation (ripening delay) and insect disinfestation (phytosanitary treatment). In this review, the application of gamma irradiation to chestnuts is discussed, including production data, the irradiated species and the effects on biological (sprouting, rotting, respiration rate, insects, worms and fungi), physico-chemical (color, texture, and drying rate), nutritional (energetic value, proteins, sugars and fatty acids) and antioxidant (tocopherols, ascorbic acid, phenolics, flavonoids and antioxidant activity) parameters. These changes are the basis for detecting if the food product has been irradiated or not. The validation of standards used for detection of food irradiation, as applied to chestnuts, is also discussed.


Assuntos
Raios gama , Valor Nutritivo , Nozes , Nozes/química
5.
Artif Organs ; 34(2): 136-40, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19817728

RESUMO

We propose a new, low-cost pulsatile ventricular assist device (VAD) for short-term applications. The new device could prove very useful in emergency ventricular failure in which patient survival is not assured. In these cases, the device allows ventricular function to be maintained as the patient's situation is evaluated and a decision is made on whether to perform a heart transplant or to replace the device with a long-term VAD. The device has a pneumatic tubular blood chamber, clip valves over the cannulae, and a compliant input chamber that improves filling of the pump. Clip valves and all other functions of the device are controlled by means of a computerized console. The use of clip valves reduces the cost of the disposable part of the device.


Assuntos
Desenho de Equipamento/economia , Insuficiência Cardíaca/cirurgia , Coração Auxiliar/economia , Circulação Assistida/economia , Humanos , Fluxo Pulsátil
6.
J Environ Radioact ; 98(3): 229-50, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17611005

RESUMO

(210)Pb and (137)Cs dating methods, accompanied by a high-resolution geochemical study, were applied to intertidal sediments containing both fine and coarse-grained particles and also, anthropogenic Pb in order to establish sedimentation rates and historical trends in heavy metal input. Sedimentation rates were established according to the "Constant Flux:Constant Sedimentation" (CF:CS) (210)Pb dating model, which was preferred rather than the "Constant Rate of Supply-Minimum Variance" (CRS-MV) model. Variations in sediment grain-size were accounted for by application of several normalization procedures. Al was selected for grain-size correction. Corrected sedimentation rates obtained from (210)Pb dating were corroborated through a second independent radionuclide tracer and by comparison of peak trace metal inputs into the environment with peaks in the sediment. The Chernobyl maximum was identified in the normalized (137)Cs activity profile. Sedimentation rates of 6.2+/-1.2 mm y(-1) and 3.1+/-0.5 mm y(-1) for the upper (two muddy layers) and 6.0+/-2.0 mm y(-1) for the lower (sandy) intertidal mud flat deposits of San Simón Bay were determined. According to the established chronology, human-induced environmental changes were detected in total metal concentrations (Cu, Pb, Zn) and in sediment grain-size and composition.


Assuntos
Sedimentos Geológicos/análise , Metais Pesados/análise , Água do Mar/análise , Poluentes Radioativos da Água/análise , Radioisótopos de Césio/análise , Monitoramento Ambiental , Geografia , Radioisótopos de Chumbo/análise , Metais Pesados/química , Espanha , Espectrometria gama , Poluentes Radioativos da Água/química
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