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1.
Am J Kidney Dis ; 83(3): 350-359.e1, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37777059

RESUMO

RATIONALE & OBJECTIVE: Atrial fibrillation (AF) and chronic kidney disease (CKD) often coexist. However, it is not known whether CKD is an independent risk factor for incident AF. Therefore, we evaluated the association between markers of CKD-estimated glomerular filtration rate (eGFR) and albuminuria-and incident AF. STUDY DESIGN: Systematic review and meta-analysis of cohort studies and randomized controlled trials. SETTING & STUDY POPULATIONS: Participants with measurement of eGFR and/or albuminuria who were not receiving dialysis. SELECTION CRITERIA FOR STUDIES: Cohort studies and randomized controlled trials were included that reported incident AF risk in adults according to eGFR and/or albuminuria. ANALYTICAL APPROACH: Age- or multivariate-adjusted risk ratios (RRs) for incident AF were extracted from cohort studies, and RRs for each trial were derived from event data. RRs for incident AF were pooled using random-effects models. RESULTS: 38 studies involving 28,470,249 participants with 530,041 incident AF cases were included. Adjusted risk of incident AF was greater among participants with lower eGFR than those with higher eGFR (eGFR<60 vs≥60mL/min/1.73m2: RR, 1.43; 95% CI, 1.30-1.57; and eGFR<90 vs≥90mL/min/1.73m2: RR, 1.42; 95% CI, 1.26-1.60). Adjusted incident AF risk was greater among participants with albuminuria (any albuminuria vs no albuminuria: RR, 1.43; 95% CI, 1.25-1.63; and moderately to severely increased albuminuria vs normal to mildly increased albuminuria: RR, 1.64; 95% CI, 1.31-2.06). Subgroup analyses showed an exposure-dependent association between CKD and incident AF, with the risk increasing progressively at lower eGFR and higher albuminuria categories. LIMITATIONS: Lack of patient-level data, interaction between eGFR and albuminuria could not be evaluated, possible ascertainment bias due to variation in the methods of AF detection. CONCLUSIONS: Lower eGFR and greater albuminuria were independently associated with increased risk of incident AF. CKD should be regarded as an independent risk factor for incident AF. PLAIN-LANGUAGE SUMMARY: Irregular heartbeat, or atrial fibrillation (AF), is the commonest abnormal heart rhythm. AF occurs commonly in people with chronic kidney disease (CKD), and CKD is also common in people with AF. However, CKD in not widely recognized as a risk factor for new-onset or incident AF. In this research, we combined data on more than 28 million participants in 38 studies to determine whether CKD itself increases the chances of incident AF. We found that both commonly used markers of kidney disease (estimated glomerular filtration rate and albuminuria, ie, protein in the urine) were independently associated with a greater risk of incident AF. This finding suggests that CKD should be recognized as an independent risk factor for incident AF.


Assuntos
Fibrilação Atrial , Insuficiência Renal Crônica , Adulto , Humanos , Fibrilação Atrial/epidemiologia , Fibrilação Atrial/etiologia , Fibrilação Atrial/diagnóstico , Albuminúria , Insuficiência Renal Crônica/diagnóstico , Taxa de Filtração Glomerular , Fatores de Risco , Rim
3.
Phys Rev Lett ; 129(22): 222501, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36493444

RESUMO

The Cryogenic Underground Observatory for Rare Events (CUORE) at Laboratori Nazionali del Gran Sasso of INFN in Italy is an experiment searching for neutrinoless double beta (0νßß) decay. Its main goal is to investigate this decay in ^{130}Te, but its ton-scale mass and low background make CUORE sensitive to other rare processes as well. In this Letter, we present our first results on the search for 0νßß decay of ^{128}Te, the Te isotope with the second highest natural isotopic abundance. We find no evidence for this decay, and using a Bayesian analysis we set a lower limit on the ^{128}Te 0νßß decay half-life of T_{1/2}>3.6×10^{24} yr (90% CI). This represents the most stringent limit on the half-life of this isotope, improving by over a factor of 30 the previous direct search results, and exceeding those from geochemical experiments for the first time.


Assuntos
Granisetron , Meia-Vida , Teorema de Bayes
4.
Phys Rev Lett ; 126(17): 171801, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33988435

RESUMO

We measured two-neutrino double beta decay of ^{130}Te using an exposure of 300.7 kg yr accumulated with the CUORE detector. Using a Bayesian analysis to fit simulated spectra to experimental data, it was possible to disentangle all the major background sources and precisely measure the two-neutrino contribution. The half-life is in agreement with past measurements with a strongly reduced uncertainty: T_{1/2}^{2ν}=7.71_{-0.06}^{+0.08}(stat)_{-0.15}^{+0.12}(syst)×10^{20} yr. This measurement is the most precise determination of the ^{130}Te 2νßß decay half-life to date.

5.
Neurobiol Dis ; 142: 104959, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32512151

RESUMO

Fragile X Syndrome (FXS) is a neurodevelopmental disorder instigated by the absence of a key translation regulating protein, Fragile X Mental Retardation Protein (FMRP). The loss of FMRP in the CNS leads to abnormal synaptic development, disruption of critical periods of plasticity, and an overall deficiency in proper sensory circuit coding leading to hyperexcitable sensory networks. However, little is known about how this hyperexcitable environment affects inhibitory synaptic plasticity. Here, we show that in vivo layer 2/3 of the primary somatosensory cortex of the Fmr1 KO mouse exhibits basal hyperexcitability and an increase in neuronal firing rate suppression during whisker activation. This aligns with our in vitro data that indicate an increase in GABAergic spontaneous activity, a faulty mGluR-mediated inhibitory input and impaired inhibitory plasticity processes. Specifically, we find that mGluR activation sensitivity is overall diminished in the Fmr1 KO mouse leading to both a decreased spontaneous inhibitory postsynaptic input to principal cells and a disrupted form of inhibitory long-term depression (I-LTD). These data suggest an adaptive mechanism that acts to homeostatically counterbalance the cortical hyperexcitability observed in FXS.


Assuntos
Síndrome do Cromossomo X Frágil/fisiopatologia , Homeostase/fisiologia , Inibição Neural/fisiologia , Plasticidade Neuronal/fisiologia , Células Piramidais/fisiologia , Córtex Somatossensorial/fisiopatologia , Animais , Modelos Animais de Doenças , Potenciais Pós-Sinápticos Excitadores/fisiologia , Proteína do X Frágil da Deficiência Intelectual/genética , Síndrome do Cromossomo X Frágil/genética , Potenciais Pós-Sinápticos Inibidores/fisiologia , Camundongos , Camundongos Knockout
6.
Phys Rev Lett ; 124(12): 122501, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32281829

RESUMO

We report new results from the search for neutrinoless double-beta decay in ^{130} Te with the CUORE detector. This search benefits from a fourfold increase in exposure, lower trigger thresholds, and analysis improvements relative to our previous results. We observe a background of (1.38±0.07)×10^{-2} counts/(keV kg yr)) in the 0νßß decay region of interest and, with a total exposure of 372.5 kg yr, we attain a median exclusion sensitivity of 1.7×10^{25} yr. We find no evidence for 0νßß decay and set a 90% credibility interval Bayesian lower limit of 3.2×10^{25} yr on the ^{130} Te half-life for this process. In the hypothesis that 0νßß decay is mediated by light Majorana neutrinos, this results in an upper limit on the effective Majorana mass of 75-350 meV, depending on the nuclear matrix elements used.

7.
Heart Lung Circ ; 26(9): 880-886, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28623064

RESUMO

Atrial fibrillation (AF) is the most common cardiac arrhythmia, with a lifetime risk of one in four of developing AF over the age of 40 years. Around 40% of patients are asymptomatic, which is of concern as AF is a major risk factor for stroke. Early detection and appropriate management reduces stroke risk by two-thirds. Atrial fibrillation screening is now recommended in international guidelines, but there are some common arguments against screening. Overall, to be of value any screening program must fulfil the World Health Organization (WHO) Wilson and Jungner criteria for screening programs. In this paper we address the common arguments, and determine if AF screening fulfils the WHO criteria.


Assuntos
Diagnóstico Precoce , Programas de Rastreamento , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/epidemiologia , Eletrocardiografia , Saúde Global , Humanos , Morbidade/tendências , Fatores de Risco
8.
Heart Lung Circ ; 26(2): 150-156, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27469897

RESUMO

AIMS AND OBJECTIVES: To investigate whether using the 'think aloud' technique during standard quality of life surveys provides useful additional information about patients' experiences of living with atrial fibrillation (AF) and health related quality of life (HRQoL). BACKGROUND: Atrial fibrillation is the most common cardiac arrhythmia and has serious health consequences, particularly ischaemic stroke, high rates of morbidity and mortality and poor HRQoL. Standard quality-of-life questionnaires are often used but may not provide sufficient detail of patients' experiences living with AF. DESIGN: A qualitative interpretative study based on semi-structured interviews. METHODS: Patients with AF (n=12) were recruited from the Choice of Health Options in Prevention of Cardiovascular Events-in Atrial Fibrillation (CHOICE-AF), a risk factor management program. Participants were interviewed using a 'think aloud' technique with questions guided by the AF Effects on Quality Of Life Questionnaire (AFEQT) and the Short Form-12 (SF-12). Interviews were audio-recorded, transcribed and analysed thematically. RESULTS: Participants had a median age of 71 years (interquartile range 52 to 77 years), and included four women and eight men. Four themes were identified related to experiences of living with AF and HRQoL including: (1) the adverse impact of atrial fibrillation symptoms, treatments, and related knowledge; (2) loss of function or independence; (3) the influence of age; and (4) approach to life. CONCLUSIONS: Atrial fibrillation, especially in older adults, creates an additional layer of requirements for self-management onto existing self-care needs. Even for patients with relatively high HRQoL, the 'think aloud' technique together with standard HRQoL questionnaires can help identify additional issues that can be addressed by health professionals to improve the HRQoL of these patients.


Assuntos
Fibrilação Atrial , Qualidade de Vida , Inquéritos e Questionários , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
Europace ; 18(1): 37-50, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26481149

RESUMO

At least 30 million people worldwide carry a diagnosis of atrial fibrillation (AF), and many more suffer from undiagnosed, subclinical, or 'silent' AF. Atrial fibrillation-related cardiovascular mortality and morbidity, including cardiovascular deaths, heart failure, stroke, and hospitalizations, remain unacceptably high, even when evidence-based therapies such as anticoagulation and rate control are used. Furthermore, it is still necessary to define how best to prevent AF, largely due to a lack of clinical measures that would allow identification of treatable causes of AF in any given patient. Hence, there are important unmet clinical and research needs in the evaluation and management of AF patients. The ensuing needs and opportunities for improving the quality of AF care were discussed during the fifth Atrial Fibrillation Network/European Heart Rhythm Association consensus conference in Nice, France, on 22 and 23 January 2015. Here, we report the outcome of this conference, with a focus on (i) learning from our 'neighbours' to improve AF care, (ii) patient-centred approaches to AF management, (iii) structured care of AF patients, (iv) improving the quality of AF treatment, and (v) personalization of AF management. This report ends with a list of priorities for research in AF patients.


Assuntos
Fibrilação Atrial/diagnóstico , Fibrilação Atrial/terapia , Cardiologia/normas , Procedimentos Clínicos/normas , Guias de Prática Clínica como Assunto , Melhoria de Qualidade/normas , Europa (Continente) , Humanos
10.
Phys Rev Lett ; 115(10): 102502, 2015 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-26382673

RESUMO

We report the results of a search for neutrinoless double-beta decay in a 9.8 kg yr exposure of (130)Te using a bolometric detector array, CUORE-0. The characteristic detector energy resolution and background level in the region of interest are 5.1±0.3 keV FWHM and 0.058±0.004(stat)±0.002(syst)counts/(keV kg yr), respectively. The median 90% C.L. lower-limit half-life sensitivity of the experiment is 2.9×10(24) yr and surpasses the sensitivity of previous searches. We find no evidence for neutrinoless double-beta decay of (130)Te and place a Bayesian lower bound on the decay half-life, T(1/2)(0ν)>2.7×10(24) yr at 90% C.L. Combining CUORE-0 data with the 19.75 kg yr exposure of (130)Te from the Cuoricino experiment we obtain T(1/2)(0ν)>4.0×10(24) yr at 90% C.L. (Bayesian), the most stringent limit to date on this half-life. Using a range of nuclear matrix element estimates we interpret this as a limit on the effective Majorana neutrino mass, m(ßß)<270-760 meV.

11.
Phys Rev Lett ; 110(1): 012504, 2013 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-23383785

RESUMO

The MuCap experiment at the Paul Scherrer Institute has measured the rate Λ(S) of muon capture from the singlet state of the muonic hydrogen atom to a precision of 1%. A muon beam was stopped in a time projection chamber filled with 10-bar, ultrapure hydrogen gas. Cylindrical wire chambers and a segmented scintillator barrel detected electrons from muon decay. Λ(S) is determined from the difference between the µ(-) disappearance rate in hydrogen and the free muon decay rate. The result is based on the analysis of 1.2 × 10(10) µ(-) decays, from which we extract the capture rate Λ(S) = (714.9 ± 5.4(stat) ± 5.1(syst)) s(-1) and derive the proton's pseudoscalar coupling g(P)(q(0)(2) = -0.88 m(µ)(2)) = 8.06 ± 0.55.

12.
Phys Rev Lett ; 110(6): 062502, 2013 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-23432237

RESUMO

We present results from the first phase of the KamLAND-Zen double-beta decay experiment, corresponding to an exposure of 89.5 kg yr of (136)Xe. We obtain a lower limit for the neutrinoless double-beta decay half-life of T(1/2)(0ν)>1.9×10(25) yr at 90% C.L. The combined results from KamLAND-Zen and EXO-200 give T(1/2)(0ν)>3.4×10(25) yr at 90% C.L., which corresponds to a Majorana neutrino mass limit of <(120-250) meV based on a representative range of available matrix element calculations. Using those calculations, this result excludes the Majorana neutrino mass range expected from the neutrinoless double-beta decay detection claim in (76)Ge, reported by a part of the Heidelberg-Moscow Collaboration, at more than 97.5% C.L.

13.
Clin Exp Pharmacol Physiol ; 40(9): 662-70, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23819722

RESUMO

In the present study, we tested whether serum amyloid A (SAA) protein, an established biomarker of inflammation, also plays a role in stimulating neovascularization. To evaluate this possibility, human carotid artery endothelial (HCtAE) cells were cultured and cellular migration and the proinflammatory and/or thrombotic activity of SAA (0, 1 or 10 µg/mL) on vascular endothelial cells was verified by determining gene regulation relative to control (in the absence of SAA). Exposure of HCtAE cells to SAA increased expression of the transcription factor nuclear factor-κB (NFKB), tumour necrosis factor (TNF) and pro-coagulative tissue factor (F3), and stimulated phosphorylation of the P65 subunit of the NFKB complex. Enhanced production of TNF and NFKB was paralleled by increased vascular endothelial growth factor (VEGF) mRNA and protein expression, as demonstrated by quantitative polymerase chain reaction, western blotting and ELISA. Administration of 10 µg/mL SAA enhanced endothelial cell migration (1.6-fold vs control), stimulated regrowth of HCtAE cells after mechanical injury (~1.2-fold vs control) and increased endothelial tube formation relative to control after 6 h. The SAA-mediated enhancement of endothelial cell migration, proliferation and tube formation were markedly inhibited by pretreatment of HCtAE cells with the multi-angiokinase receptor inhibitor BIBF1120 (100 nmol/L), although SAA-stimulated gene responses for F3 and NFKB were unaffected by 100 nmol/L BIBF1120 pretreatment. Overall, BIBF1120 inhibited the pro-angiogenic activity of SAA on vascular endothelial cells in this experimental model of inflammation.


Assuntos
Movimento Celular/genética , Células Endoteliais/metabolismo , Indóis/farmacologia , Proteína Amiloide A Sérica/metabolismo , Artérias Carótidas/efeitos dos fármacos , Artérias Carótidas/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Células Endoteliais/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Humanos , Inflamação/genética , Inflamação/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , NF-kappa B/genética , NF-kappa B/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Fosforilação/efeitos dos fármacos , Fosforilação/genética , Proteína Amiloide A Sérica/genética , Tromboplastina/genética , Tromboplastina/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
14.
J Neuroophthalmol ; 33(4): 370-2, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23845997

RESUMO

A 54-year-old woman with relapsing-remitting multiple sclerosis (MS) developed visual loss in her left eye due to a macular hemorrhage 11 months after starting fingolimod. Visual acuity was 20/80 in the left eye, with a dense retinal hemorrhage involving the fovea with adjacent hard exudate and macular thickening confirmed by spectral domain optical coherence tomography. Three months after stopping fingolimod, vision in the left eye improved to 20/30 with resolution of the macular hemorrhage and exudates. Fingolimod has been associated with macular edema, but prior to this report, the authors are unaware of it causing a macular hemorrhage in a MS patient. The authors speculate that the macular hemorrhage may be due to a disruption of cellular adhesions between vascular endothelial cells that maintain the inner blood-retinal barrier.


Assuntos
Cegueira/etiologia , Hemorragia/tratamento farmacológico , Hemorragia/patologia , Imunossupressores/uso terapêutico , Macula Lutea/patologia , Propilenoglicóis/uso terapêutico , Esfingosina/análogos & derivados , Feminino , Cloridrato de Fingolimode , Angiofluoresceinografia , Hemorragia/etiologia , Humanos , Pessoa de Meia-Idade , Esclerose Múltipla Recidivante-Remitente/complicações , Esfingosina/uso terapêutico , Tomografia de Coerência Óptica
16.
Phys Rev Lett ; 107(10): 102301, 2011 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-21981496

RESUMO

We report the results of an improved determination of the triple correlation DP·(p(e)×p(v)) that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the standard model. Our result is D=[-0.96±1.89(stat)±1.01(sys)]×10(-4). The corresponding phase between gA and gV is ϕAV=180.013°±0.028° (68% confidence level). This result represents the most sensitive measurement of D in nuclear ß decay.

17.
Eur J Cardiovasc Prev Rehabil ; 18(2): 278-86, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20606594

RESUMO

OBJECTIVE: To determine if the improved risk factor profile at 1 year attributed to the Choice of Health Options In prevention of Cardiovascular Events (CHOICE) program was maintained at 4 years. DESIGN: Single-blind randomized controlled trial with post-hoc 476 months follow-up (76% complete). SETTING: Australian tertiary referral hospital. PATIENTS: Two hundred and eight acute coronary syndrome survivors. INTERVENTIONS: Acute coronary syndrome survivors not accessing cardiac rehabilitation (CR) were randomized to control (n=72) or CHOICE (n=72) comprising the tailored risk factor reduction packaged as a clinic visit and 3 months phone support. A contemporary CR reference group were also recruited (n=64). Blinded risk assessment occurred at baseline, 1 and 4 years. MAIN OUTCOME MEASURES: Total cholesterol, systolic blood pressure, smoking status, physical activity. RESULTS: One year improvements in all the modifiable risk factors achieved in CHOICE were maintained at 4 years. CHOICE and control were well-matched at baseline. At 4 years, there was a trend towards lower total cholesterol in CHOICE compared with controls (mean 4.0±0.1 vs. 4.2±0.1 mmol/l, P=0.05), significantly better systolic blood pressure (mean 132.2±2.1 vs. 136.8±2.0 mmHg, P=0.01), physical activity scores (1200±209 vs. 968±196 metabolic equivalent min/week, P=0.02) and proportion with three or more risk factors above national targets (20 vs. 42%,P=0.02). Participants in CHOICE were at higher baseline risk than CR but at 4 years they had similar risk factor profiles. CONCLUSION: Participants in CHOICE maintained favorable changes in coronary risk profile at 4 years compared with control, indicating that CHOICE is an effective long-term intervention among those not accessing facility-based CR.


Assuntos
Síndrome Coronariana Aguda/terapia , Administração de Caso , Prevenção Secundária/métodos , Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/etiologia , Síndrome Coronariana Aguda/fisiopatologia , Síndrome Coronariana Aguda/prevenção & controle , Biomarcadores/sangue , Pressão Sanguínea , Índice de Massa Corporal , Distribuição de Qui-Quadrado , Colesterol/sangue , Exercício Físico , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , New South Wales , Medição de Risco , Fatores de Risco , Método Simples-Cego , Abandono do Hábito de Fumar , Fatores de Tempo , Resultado do Tratamento
18.
J Immunol ; 183(1): 593-603, 2009 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-19542470

RESUMO

Macrophages, cytokines, and matrix metalloproteinases (MMP) play important roles in atherogenesis. The Ca(2+)-binding protein S100A12 regulates monocyte migration and may contribute to atherosclerosis by inducing proinflammatory cytokines in macrophages. We found significantly higher S100A12 levels in sera from patients with coronary artery disease than controls and levels correlated positively with C-reactive protein. S100A12 was released into the coronary circulation from ruptured plaque in acute coronary syndrome, and after mechanical disruption by percutaneous coronary intervention in stable coronary artery disease. In contrast to earlier studies, S100A12 did not stimulate proinflammatory cytokine production by human monocytes or macrophages. Similarly, no induction of MMP genes was found in macrophages stimulated with S100A12. Because S100A12 binds Zn(2+), we studied some functional aspects that could modulate atherogenesis. S100A12 formed a hexamer in the presence of Zn(2+); a novel Ab was generated that specifically recognized this complex. By chelating Zn(2+), S100A12 significantly inhibited MMP-2, MMP-9, and MMP-3, and the Zn(2+)-induced S100A12 complex colocalized with these in foam cells in human atheroma. S100A12 may represent a new marker of this disease and may protect advanced atherosclerotic lesions from rupture by inhibiting excessive MMP-2 and MMP-9 activities by sequestering Zn(2+).


Assuntos
Aterosclerose/metabolismo , Doença das Coronárias/metabolismo , Proteínas S100/fisiologia , Adulto , Idoso , Aterosclerose/patologia , Biomarcadores/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Doença das Coronárias/patologia , Feminino , Humanos , Mediadores da Inflamação/sangue , Mediadores da Inflamação/fisiologia , Macrófagos/enzimologia , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Inibidores de Metaloproteinases de Matriz , Pessoa de Meia-Idade , Ruptura Espontânea/enzimologia , Ruptura Espontânea/metabolismo , Ruptura Espontânea/prevenção & controle , Proteínas S100/sangue , Proteína S100A12 , Zinco/fisiologia
19.
Nature ; 436(7050): 499-503, 2005 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-16049478

RESUMO

The detection of electron antineutrinos produced by natural radioactivity in the Earth could yield important geophysical information. The Kamioka liquid scintillator antineutrino detector (KamLAND) has the sensitivity to detect electron antineutrinos produced by the decay of 238U and 232Th within the Earth. Earth composition models suggest that the radiogenic power from these isotope decays is 16 TW, approximately half of the total measured heat dissipation rate from the Earth. Here we present results from a search for geoneutrinos with KamLAND. Assuming a Th/U mass concentration ratio of 3.9, the 90 per cent confidence interval for the total number of geoneutrinos detected is 4.5 to 54.2. This result is consistent with the central value of 19 predicted by geophysical models. Although our present data have limited statistical power, they nevertheless provide by direct means an upper limit (60 TW) for the radiogenic power of U and Th in the Earth, a quantity that is currently poorly constrained.

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