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1.
J Am Soc Mass Spectrom ; 30(2): 278-288, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30291556

RESUMO

The integration of the liquid sampling-atmospheric pressure glow discharge (LS-APGD) ion source with Orbitrap mass spectrometers has resulted in new opportunities in the field of isotope ratio mass spectrometry. In a field that has been dominated by thermal ionization mass spectrometry (TIMS) and inductively coupled plasma mass spectrometry (ICP-MS) on quadrupole and scanning-mode sector field analyzer platforms for highly accurate and precise measurements, the LS-APGD-Orbitrap system offers a benchtop instrument capable of meeting the rigorous International Target Values for measurement uncertainty for uranium (U). In order to benchmark the LS-APGD-Orbitrap, a series of U certified reference materials with increasing 235U isotopic composition were analyzed. By using U samples ranging in enrichment from 1 to 80%, the ability of the system to measure isotope ratios over a wide range is demonstrated. This analysis represents the first time that the LS-APGD-Orbitrap system has been used to analyze highly enriched U samples, allowing for the measurement of each of the U isotopes, including 234U and 236U-related species, which had not been achieved previously. Ultimately, the LS-APGD-Orbitrap system was able to measure CRM U-800 (assayed as 235U / 238U = 4.265622) as 4.266922, with a combined uncertainty, (uc), of 0.040%. These results are compared to those obtained using traditional elemental mass spectrometers including TIMS and ICP-MS-based instruments. The effectiveness of the LS-APGD-Orbitrap MS system for measuring U isotopes shows excellent promise in nuclear forensics, safeguards, and other nuclear weapon-based applications. Graphical Abstract ᅟ.

2.
East Asian Arch Psychiatry ; 27(3): 97-105, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28993542

RESUMO

INTRODUCTION: Understanding and perceptions about mental illness vary among individuals based on their experience with the illness or their contact with the people affected by it. These may be further influenced by the individuals' sociocultural background. This study aimed to understand the differences in the beliefs about, understanding of, and explanations for mental illness between different population groups of Jharkhand, India. METHODS: During July 2014 to February 2016, we recruited the following 3 groups of individuals aged between 18 and 60 years: individuals with mental illness (group 1, n = 240), relatives of individuals with mental illness (group 2, n = 240), and the general public (group 3, n = 240). Qualitative and quantitative findings were combined in this study, and participants were asked about their beliefs about, understanding of, and explanations about mental illness. RESULTS: Individuals with mental illness and their relatives shared similar beliefs whereas the general public held a different opinion in various domains. There were significant differences among all groups in their understanding of various aspects of mental illnesses including the definition, causes, signs and symptoms, treatment, and outcomes. CONCLUSION: Individuals' perception towards different aspects of mental illness varies, despite they are sharing the same sociocultural milieu. Differences in beliefs, understanding, and explanations may lead to conflicts in treatment goals and expectations, and hamper the intervention strategies that promote mental health and patient care. Focused strategies to develop uniformity in beliefs and explanations about various aspects of mental illness may help to develop collaboration with different community groups that may in turn help in developing effective interventions and treatment.


Assuntos
Família/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Transtornos Mentais/psicologia , Opinião Pública , Adolescente , Adulto , Feminino , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
4.
Geophys Res Lett ; 25(23): 4293-6, 1998 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-11542821

RESUMO

Stepwise etching of lunar soil ilmenite grains reveals that the 15N/14N ratio of implanted nitrogen decreases with increasing implantation depth within the ilmenite grains, i.e., with increasing energy of implantation. These results show that N derived from solar energetic particles, NSEP, is enriched in the light isotope, 14N, relative to solar-wind nitrogen, NSW. This is in striking contrast to the neon isotopic record: NeSEP is depleted in the light isotope, 20Ne, relative to NeSW. These data suggest either distinct signatures in the respective solar source regions, or fractionation in the acceleration mechanism(s). However, the observed opposite fractionation trends for light N and Ne isotopes do not agree with model predictions.


Assuntos
Lua , Neônio , Nitrogênio , Solo/análise , Atividade Solar , Meio Ambiente Extraterreno , Ferro , Isótopos , Modelos Químicos , Isótopos de Nitrogênio , Temperatura , Titânio
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