Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Eur J Clin Nutr ; 74(5): 834-841, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31685967

RESUMO

BACKGROUND/OBJECTIVES: Although dietary calcium intake is associated with a risk of cardiovascular disease (CVD), it has not been studied extensively in Asian populations. We therefore investigated the association between dietary calcium intake and CVD among Korean adults and the effect of obesity on this association. SUBJECTS/METHODS: In total, 9186 participants were included in the analysis after excluding 844 with prevalent CVD/cancer or implausible energy intake. Nutrient intake, including dietary calcium, was estimated using a validated semi-quantitative food frequency questionnaire. CVD included myocardial infarction, coronary artery disease, and stroke per the World Health Organization criteria. Cox proportional hazards models were used to calculate multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: In the fully adjusted model, HRs of CVD across increasing quintiles of dietary calcium intake were 1.0 (reference), 0.85 (95% CI: 0.66-1.10), 0.77 (95% CI: 0.58-1.02), 0.59 (95% CI: 0.42-0.83), and 0.72 (95% CI: 0.48-1.08); a significant linear trend was detected (p for trend = 0.04). However, this association varied according to the obesity status. High dietary calcium intake was associated with a reduced CVD risk among nonobese participants (body mass index [BMI] < 25 kg/m2; p for trend = 0.02), whereas this was not significant among obese participants (BMI ≥ 25 kg/m2; p for trend = 0.88). CONCLUSIONS: The association between dietary calcium intake and incident CVD may be influenced by obesity status. We provide evidence for developing dietary calcium intake guidelines for Koreans, allowing for the effects of obesity.


Assuntos
Cálcio da Dieta/administração & dosagem , Doenças Cardiovasculares/epidemiologia , Dieta/estatística & dados numéricos , Adulto , Idoso , Doenças Cardiovasculares/dietoterapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Modelos de Riscos Proporcionais , República da Coreia/epidemiologia , Fatores de Risco , Inquéritos e Questionários
2.
Phys Rev Lett ; 121(5): 051101, 2018 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-30118264

RESUMO

We present the precision measurement from May 2011 to May 2017 (79 Bartels rotations) of the proton fluxes at rigidities from 1 to 60 GV and the helium fluxes from 1.9 to 60 GV based on a total of 1×10^{9} events collected with the Alpha Magnetic Spectrometer aboard the International Space Station. This measurement is in solar cycle 24, which has the solar maximum in April 2014. We observed that, below 40 GV, the proton flux and the helium flux show nearly identical fine structures in both time and relative amplitude. The amplitudes of the flux structures decrease with increasing rigidity and vanish above 40 GV. The amplitudes of the structures are reduced during the time period, which started one year after solar maximum, when the proton and helium fluxes steadily increase. Above ∼3 GV the p/He flux ratio is time independent. We observed that below ∼3 GV the ratio has a long-term decrease coinciding with the period during which the fluxes start to rise.

3.
Phys Rev Lett ; 121(5): 051102, 2018 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-30118287

RESUMO

We present high-statistics, precision measurements of the detailed time and energy dependence of the primary cosmic-ray electron flux and positron flux over 79 Bartels rotations from May 2011 to May 2017 in the energy range from 1 to 50 GeV. For the first time, the charge-sign dependent modulation during solar maximum has been investigated in detail by leptons alone. Based on 23.5×10^{6} events, we report the observation of short-term structures on the timescale of months coincident in both the electron flux and the positron flux. These structures are not visible in the e^{+}/e^{-} flux ratio. The precision measurements across the solar polarity reversal show that the ratio exhibits a smooth transition over 830±30 days from one value to another. The midpoint of the transition shows an energy dependent delay relative to the reversal and changes by 260±30 days from 1 to 6 GeV.

4.
Phys Rev Lett ; 120(2): 021101, 2018 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-29376729

RESUMO

We report on the observation of new properties of secondary cosmic rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary cosmic rays has also been observed in the AMS measurement of primary cosmic rays He, C, and O but the rigidity dependences of primary cosmic rays and of secondary cosmic rays are distinctly different. In particular, above 200 GV, the secondary cosmic rays harden more than the primary cosmic rays.

5.
Phys Rev Lett ; 119(25): 251101, 2017 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-29303302

RESUMO

We report the observation of new properties of primary cosmic rays He, C, and O measured in the rigidity (momentum/charge) range 2 GV to 3 TV with 90×10^{6} helium, 8.4×10^{6} carbon, and 7.0×10^{6} oxygen nuclei collected by the Alpha Magnetic Spectrometer (AMS) during the first five years of operation. Above 60 GV, these three spectra have identical rigidity dependence. They all deviate from a single power law above 200 GV and harden in an identical way.

6.
Phys Rev Lett ; 117(23): 231102, 2016 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-27982618

RESUMO

Knowledge of the rigidity dependence of the boron to carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. The precise measurement of the B/C ratio from 1.9 GV to 2.6 TV, based on 2.3 million boron and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. The detailed variation with rigidity of the B/C spectral index is reported for the first time. The B/C ratio does not show any significant structures in contrast to many cosmic ray models that require such structures at high rigidities. Remarkably, above 65 GV, the B/C ratio is well described by a single power law R^{Δ} with index Δ=-0.333±0.014(fit)±0.005(syst), in good agreement with the Kolmogorov theory of turbulence which predicts Δ=-1/3 asymptotically.

7.
Phys Rev Lett ; 117(9): 091103, 2016 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-27610839

RESUMO

A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49×10^{5} antiproton events and 2.42×10^{9} proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500 GV, the antiproton p[over ¯], proton p, and positron e^{+} fluxes are found to have nearly identical rigidity dependence and the electron e^{-} flux exhibits a different rigidity dependence. Below 60 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios each reaches a maximum. From ∼60 to ∼500 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.

8.
Phys Rev Lett ; 115(21): 211101, 2015 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-26636836

RESUMO

Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.

9.
Phys Rev Lett ; 114(17): 171103, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25978222

RESUMO

A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of cosmic rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.

10.
Phys Rev Lett ; 113(22): 221102, 2014 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-25494065

RESUMO

We present a measurement of the cosmic ray (e^{+}+e^{-}) flux in the range 0.5 GeV to 1 TeV based on the analysis of 10.6 million (e^{+}+e^{-}) events collected by AMS. The statistics and the resolution of AMS provide a precision measurement of the flux. The flux is smooth and reveals new and distinct information. Above 30.2 GeV, the flux can be described by a single power law with a spectral index γ=-3.170±0.008(stat+syst)±0.008(energy scale).

11.
Phys Rev Lett ; 113(12): 121102, 2014 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-25279617

RESUMO

Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ∼30 GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The determination of the differing behavior of the spectral indices versus energy is a new observation and provides important information on the origins of cosmic-ray electrons and positrons.

12.
Phys Rev Lett ; 113(12): 121101, 2014 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-25279616

RESUMO

A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200 GeV the positron fraction no longer exhibits an increase with energy.

13.
Gene Ther ; 21(1): 106-14, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24225639

RESUMO

For successful clinical tumor immunotherapy outcomes, strong immune responses against tumor antigens must be generated. Cell-based vaccines compromise one strategy with which to induce appropriate strong immune responses. Previously, we established a natural killer T-cell (NKT) ligand-loaded, adenoviral vector-transduced B-cell-based anticancer cellular vaccine. To enhance tumor antigen delivery to B cells, we established a modified adenoviral vector (Ad-k35) that encoded a truncated form of the breast cancer antigen Her2/neu (Ad-k35HM) in which fiber structure was substituted with adenovirus serotype 35. We observed increased tumor antigen expression with Ad-k35HM in both human and murine B cells. In addition, an Ad-k35HM-transduced B-cell vaccine elicited strong antigen-specific cellular and humoral immune responses that were further enhanced with the additional loading of soluble NKT ligand KBC009. An Ad-k35HM-transduced, KBC009-loaded B-cell vaccine efficiently suppressed the in vivo growth of established tumors in a mouse model. Moreover, the vaccine elicited human leukocyte antigen (HLA)-A2 epitope-specific cytotoxic T-cell responses in B6.Cg (CB)-Tg (HLA-A/H2-D) 2Enge/Jat mice. These findings indicated that the Ad-k35 could be appropriate for the preclinical and clinical development of B-cell-based anticancer immunotherapies.


Assuntos
Linfócitos B/imunologia , Vacinas Anticâncer , Dependovirus/genética , Neoplasias Mamárias Experimentais/terapia , Receptor ErbB-2/genética , Animais , Linfócitos B/virologia , Vacinas Anticâncer/imunologia , Células Cultivadas , Dependovirus/metabolismo , Feminino , Vetores Genéticos , Antígeno HLA-A2/imunologia , Humanos , Imunoterapia , Neoplasias Mamárias Experimentais/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Células T Matadoras Naturais/imunologia , Receptor ErbB-2/metabolismo , Linfócitos T Citotóxicos/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto
14.
J Food Sci ; 74(2): M62-6, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19323759

RESUMO

This study investigated temperature effects on depuration for reducing Vibrio parahaemolyticus and Vibrio vulnificus in American oyster (Crassostrea virginica). Raw oysters were inoculated with 5-strain cocktail of V. parahaemolyticus or V. vulnificus to levels of 10(4) to 10(5) MPN (most probable number)/g and depurated in artificial seawater (ASW) at 22, 15, 10, and 5 degrees C. Depuration of oysters at 22 degrees C had limited effects on reducing V. parahaemolyticus or V. vulnificus in the oysters. Populations of V. parahaemolyticus and V. vulnificus were reduced by 1.2 and 2.0 log MPN/g, respectively, after 48 h of depuration at 22 degrees C. Decreasing water temperature to 15 degrees C increased the efficacy of depuration in reducing V. parahaemolyticus and V. vulnificus in oysters. Reductions of V. parahaemolyticus and V. vulnificus in oysters increased to 2.1 and 2.9 log MPN/g, respectively, after 48 h of depuration at 15 degrees C. However, depurations at 10 and 5 degrees C were less effective than at 15 degrees C in reducing the Vibrio spp. in oysters. Extended depuration at 15 degrees C for 96 h increased reductions of V. parahaemolyticus and V. vulnificus in oysters to 2.6 and 3.3 log MPN/g, respectively.


Assuntos
Ostreidae/microbiologia , Vibrioses/prevenção & controle , Vibrio/fisiologia , Animais , Culinária , Contaminação de Alimentos/prevenção & controle , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/prevenção & controle , Humanos , Alimentos Marinhos/microbiologia , Temperatura , Vibrio/isolamento & purificação , Vibrio parahaemolyticus/isolamento & purificação , Vibrio vulnificus/isolamento & purificação
15.
J Neurobiol ; 45(1): 14-29, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10992253

RESUMO

Molecular genetic analysis indicates that rhythmic changes in the abundance of the Drosophila lark RNA-binding protein are important for circadian regulation of adult eclosion (the emergence or ecdysis of the adult from the pupal case). To define the tissues and cell types that might be important for lark function, we have characterized the spatial and developmental patterns of lark protein expression. Using immunocytochemical or protein blotting methods, lark can be detected in late embryos and throughout postembryonic development, from the third instar larval stage to adulthood. At the late pupal (pharate adult) stage, lark protein has a broad pattern of tissue expression, which includes two groups of crustacean cardioactive peptide (CCAP)-containing neurons within the ventral nervous system. In other insects, the homologous neurons have been implicated in the physiological regulation of ecdysis. Whereas lark has a nuclear distribution in most cell types, it is present in the cytoplasm of the CCAP neurons and certain other cells, which suggests that the protein might execute two different RNA-binding functions. Lark protein exhibits significant circadian changes in abundance in at least one group of CCAP neurons, with abundance being lowest during the night, several hours prior to the time of adult ecdysis. Such a temporal profile is consistent with genetic evidence indicating that the protein serves a repressor function in mediating the clock regulation of adult ecdysis. In contrast, we did not observe circadian changes in CCAP neuropeptide abundance in late pupae, although CCAP amounts were decreased in newly-emerged adults, presumably because the peptide is released at the time of ecdysis. Given the cytoplasmic localization of the lark RNA-binding protein within CCAP neurons, and the known role of CCAP in the control of ecdysis, we suggest that changes in lark abundance may regulate the translation of a factor important for CCAP release or CCAP cell excitability.


Assuntos
Ritmo Circadiano/fisiologia , Proteínas de Drosophila , Proteínas de Insetos/metabolismo , Neurônios/química , Neuropeptídeos/análise , Proteínas de Ligação a RNA/análise , Proteínas de Ligação a RNA/metabolismo , Animais , Drosophila , Proteínas de Insetos/fisiologia , Muda/fisiologia , Mutação , Neurônios/fisiologia , Neuropeptídeos/fisiologia , Neurossecreção/fisiologia , Pupa/química , Pupa/fisiologia , Proteínas de Ligação a RNA/fisiologia
16.
J Neurosci ; 19(10): 3665-73, 1999 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-10233998

RESUMO

Photic entrainment of insect circadian rhythms can occur through either extraretinal (brain) or retinal photoreceptors, which mediate sensitivity to blue light or longer wavelengths, respectively. Although visual transduction processes are well understood in the insect retina, almost nothing is known about the extraretinal blue light photoreceptor of insects. We now have identified and characterized a candidate blue light photoreceptor gene in Drosophila (DCry) that is homologous to the cryptochrome (Cry) genes of mammals and plants. The DCry gene is located in region 91F of the third chromosome, an interval that does not contain other genes required for circadian rhythmicity. The protein encoded by DCry is approximately 50% identical to the CRY1 and CRY2 proteins recently discovered in mammalian species. As expected for an extraretinal photoreceptor mediating circadian entrainment, DCry mRNA is expressed within the adult brain and can be detected within body tissues. Indeed, tissue in situ hybridization demonstrates prominent expression in cells of the lateral brain, which are close to or coincident with the Drosophila clock neurons. Interestingly, DCry mRNA abundance oscillates in a circadian manner in Drosophila head RNA extracts, and the temporal phasing of the rhythm is similar to that documented for the mouse Cry1 mRNA, which is expressed in clock tissues. Finally, we show that changes in DCry gene dosage are associated predictably with alterations of the blue light resetting response for the circadian rhythm of adult locomotor activity.


Assuntos
Proteínas de Drosophila , Proteínas do Olho , Flavoproteínas/química , Proteínas de Insetos/química , Células Fotorreceptoras de Invertebrados/química , Complexo de Proteínas do Centro de Reação Fotossintética/química , Sequência de Aminoácidos , Animais , Relógios Biológicos , Encéfalo/metabolismo , Mapeamento Cromossômico , Ritmo Circadiano/fisiologia , Criptocromos , Drosophila , Genes de Insetos , Humanos , Camundongos , Dados de Sequência Molecular , Oscilometria , RNA Mensageiro/biossíntese , Receptores Acoplados a Proteínas G , Homologia de Sequência de Aminoácidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...