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1.
Proc Natl Acad Sci U S A ; 118(22)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34039712

RESUMO

Although ultrafast manipulation of magnetism holds great promise for new physical phenomena and applications, targeting specific states is held back by our limited understanding of how magnetic correlations evolve on ultrafast timescales. Using ultrafast resonant inelastic X-ray scattering we demonstrate that femtosecond laser pulses can excite transient magnons at large wavevectors in gapped antiferromagnets and that they persist for several picoseconds, which is opposite to what is observed in nearly gapless magnets. Our work suggests that materials with isotropic magnetic interactions are preferred to achieve rapid manipulation of magnetism.

2.
J Community Health ; 45(1): 154-160, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31446542

RESUMO

Knowledge of cardiovascular health (CVH) status in rural communities is essential to implement cost-effective strategies aimed to address the growing burden of cardiovascular diseases in these settings. Here, we report on the CVH status and health metrics of 1508 community-dwellers aged ≥ 40 years in three neighboring rural villages of Coastal Ecuador (Atahualpa, El Tambo, and Prosperidad). According to the American Heart Association, a poor CVH status is designated when at least one cardiovascular health metric is in the poor range. About 70% of individuals in the villages studied had a poor CVH status, with no overall differences across villages. However, the relative prevalence of poor health metrics varied. Using Atahualpa as the referent village, a multinomial logistic regression model showed that El Tambo residents were more often smokers and had a worse diet, while Prosperidad residents had more high blood pressure but better fasting glucose levels. Probabilities of having poor health metrics were lower in Atahualpa than in El Tambo (p < 0.001), but not better than in Prosperidad (p = 0.097). Predictive estimates of having poor health metrics were significantly higher in El Tambo than in Atahualpa or in Prosperidad. This comparative study demonstrates that the CVH status of rural populations of coastal Ecuador is basically similar. However, individual health metrics in the poor range were found to vary across villages. While the three villages are generally comparable, interventions should be tailored according to local priorities. The same may occur in other rural communities, but more studies are needed to confirm our findings.


Assuntos
Doenças Cardiovasculares/epidemiologia , Nível de Saúde , População Rural/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Dieta/estatística & dados numéricos , Equador , Feminino , Humanos , Vida Independente , Masculino , Pessoa de Meia-Idade , Fatores de Risco
3.
Vascular ; 28(4): 405-412, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32228175

RESUMO

OBJECTIVE: Information on the associations among arterial stiffness, carotid intima-media thickness (cIMT) and carotid plaques as biomarkers of atherosclerosis is limited in diverse populations. We aimed to assess whether aortic pulse wave velocity (aPWV) - as a surrogate of arterial stiffness - is associated with increased cIMT and the presence of carotid plaques in a cohort of older adults of Amerindian ancestry. METHODS: Atahualpa residents aged ≥60 years (n = 320) underwent aPWV determinations, and carotid ultrasounds for cIMT and plaque assessment. Multivariate models were fitted to assess the independent association between the aPWV, and cIMT and carotid plaques, after adjusting for relevant confounders. Differences in risk factors across these biomarkers were investigated. RESULTS: Mean values of aPWV were 10.3 ± 1.8 m/s, and those of cIMT were 0.91 ± 0.21 mm (24% had a cIMT >1 mm). Carotid plaques were observed in 118 (37%) subjects. In univariate analyses, risk factors associated with an increased aPWV included age, female gender, poor physical activity and high blood pressure. An increased cIMT was associated with age, male gender, a poor diet, high blood pressure and severe tooth loss. The presence of carotid plaques was associated with increasing age, poor physical activity and high blood pressure. Multivariate models showed a significant association between aPWV and cIMT (ß: 0.028; 95% C.I.: 0.001-0.056; p = 0.047) but not between aPWV and carotid plaques (OR: 1.14; 95% C.I.: 0.83-1.56; p = 0.423). CONCLUSIONS: This study shows an independent association between aPWV and cIMT but not with carotid plaques. These biomarkers may indicate distinct phenotypes for atherosclerosis.


Assuntos
Doenças das Artérias Carótidas/diagnóstico , Espessura Intima-Media Carotídea , Placa Aterosclerótica , Análise de Onda de Pulso , Rigidez Vascular , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/etnologia , Doenças das Artérias Carótidas/fisiopatologia , Equador , Feminino , Nível de Saúde , Humanos , Vida Independente , Indígenas Sul-Americanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Valor Preditivo dos Testes , Medição de Risco , Fatores de Risco
4.
Phys Rev Lett ; 111(9): 096404, 2013 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-24033056

RESUMO

The temperature evolution of structural effects associated with charge order (CO) and spin order in La1.67Sr0.33NiO4 has been investigated using neutron powder diffraction. We report an anomalous shrinking of the c/a lattice parameter ratio that correlates with T(CO). The sign of this change can be explained by the change in interlayer Coulomb energy between the static-stripe-ordered state and the fluctuating-stripe-ordered state or the charge-disordered state. In addition, we identify a contribution to the mean-square displacements of Ni and in-plane O atoms whose width correlates quite well with the size of the pseudogap extracted from the reported optical conductivity, with a non-Debye-like component that persists below and well above T(CO). We infer that dynamic charge-stripe correlations survive to T∼2T(CO).

5.
J Prim Care Community Health ; 11: 2150132720928670, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32476552

RESUMO

Background: Arterial hypertension has been associated with severe tooth loss, but differential associations with individual components of blood pressure (BP) have scarcely been investigated. We assessed the independent associations between pulsatile/steady components of BP and severe tooth loss in community-dwelling adults residing in 3 rural Ecuadorian villages. Methods: Individuals aged ≥40 years living in Atahualpa, El Tambo, and Prosperidad were identified during door-to-door surveys. Data collection focused on the number of remaining teeth and measurements of pulsatile/steady components of BP. Multivariate models were fitted to assess independent associations between pulsatile/steady BP components and severe tooth loss, after adjusting for relevant covariates. Results: A total of 1543 individuals were included. Oral exams identified 426 (28%) individuals with severe tooth loss. BP levels ≥140/90 mm Hg were determined in 481 (31%) individuals. The mean pulse pressure (PP) level was 55.3 ± 19 mm Hg. For systolic BP (SBP), the mean level was 133.1 ± 23.5 mm Hg, and for diastolic BP (DBP) it was 77.8 ± 11.5 mm Hg. Univariate models showed significant associations between severe tooth loss and SBP and PP, but not with DBP. However, the significance was taken away in fully adjusted generalized linear models. Age remained as an independent significant covariate in models using SBP and PP. Causal mediation analyses disclosed that percentages of the effect of severe tooth loss mediated by age were 99.5% for SBP and 98.9% for PP. Conclusion: This study shows that age captures most of the effect of the association between pulsatile components of BP and severe tooth loss.


Assuntos
Hipertensão , Perda de Dente , Adulto , Pressão Sanguínea , Equador/epidemiologia , Humanos , Hipertensão/complicações , Hipertensão/epidemiologia , População Rural , Perda de Dente/epidemiologia , Perda de Dente/etiologia
6.
Clin Neurol Neurosurg ; 194: 105795, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32220695

RESUMO

OBJECTIVE: Cerebral small vessel disease (cSVD) and large artery atherosclerosis (LAA) are related to different pathogenetic mechanisms. However, relationships between single biomarkers of cSVD and LAA affecting isolated vascular beds have been reported. Using the Atahualpa Project cohort, we aimed to assess the association between cSVD score categories and LAA burden in community-dwelling older adults. PATIENTS AND METHODS: Atahualpa individuals aged ≥60 years undergoing assessment of the cSVD score and LAA in the peripheral, carotid extracranial, and intracranial vascular beds (n = 333) were included. Multivariate models were fitted to assess independent associations between the cSVD score and LAA burden. RESULTS: The cSVD score was 0 points in 62 % individuals, 1 point in 19 %, 2 points in 13 %, and 3-4 points in 7 %. LAA involved the extracranial carotid bed in 43 % individuals, the intracranial bed in 36 %, and the peripheral bed in 20 %. One vascular bed was involved in 111 (33 %) individuals, two beds in 75 (23 %), and three beds in 23 (7 %). The remaining 124 (37 %) had no atherosclerosis. Ordinal logistic regression models showed progressively greater associations between higher categories of cSVD score and the odds of having more beds involved with LAA. Multinomial logistic regression models showed associations between categories of cSVD score and LAA burden, but only when two or three vascular beds were involved. CONCLUSION: This study demonstrates robust associations between the cSVD score and LAA, which become evident at the upper end of the spectrum of cSVD score (3-4 points) and LAA burden (2-3 vascular beds involved).


Assuntos
Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Doenças de Pequenos Vasos Cerebrais/epidemiologia , Arteriosclerose Intracraniana/diagnóstico por imagem , Arteriosclerose Intracraniana/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/epidemiologia , Infarto Cerebral/diagnóstico por imagem , Infarto Cerebral/epidemiologia , Circulação Cerebrovascular , Estudos de Coortes , Efeitos Psicossociais da Doença , Equador/epidemiologia , Feminino , Inquéritos Epidemiológicos , Humanos , Vida Independente , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Fatores de Risco , Ultrassonografia
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