Sulfur-mediated photochemical energy harvesting in nanoporous carbons

This work provides new insights in the field of applied photochemistry based on semiconductor-free nanoporous carbons and its application to sunlight energy harvesting. Using carbon materials of increasing average pore size, chemical functionalization to introduce a variety of O- and S-containing functional groups and monochromatic light, we have shown the dependence of the photochemical conversion of phenol in the confinement of the carbons nanopore space with the wavelength of the irradiation source, the dimensions of the pore voids and their surface chemistry. The photochemical conversion of phenol inside the carbons pore space was found to be very sensitive to the nature of the S-containing groups and the confinement state of the adsorbed pollutant.COA thanks the financial support of the European Research Council through a Consolidator Grant (ERC-CoG-648161-PHOROSOL) and the Spanish MINECO (CTM2014/56770-R). AGB thanks her PhD fellowship (BES-2012-060410). TJB acknowledges the NSF support (CBET 1133112)

Sulfur-mediated photochemical energy harvesting in nanoporous carbons

This work provides new insights in the field of applied photochemistry based on semiconductor-free nanoporous carbons and its application to sunlight energy harvesting. Using carbon materials of increasing average pore size, chemical functionalization to introduce a variety of O- and S-containing functional groups and monochromatic light, we have shown the dependence of the photochemical conversion of phenol in the confinement of the carbons nanopore space with the wavelength of the irradiation source, the dimensions of the pore voids and their surface chemistry. The photochemical conversion of phenol inside the carbons pore space was found to be very sensitive to the nature of the S-containing groups and the confinement state of the adsorbed pollutant.COA thanks the financial support of the European Research Council through a Consolidator Grant (ERC-CoG-648161-PHOROSOL) and the Spanish MINECO (CTM2014/56770-R). AGB thanks her PhD fellowship (BES-2012-060410). TJB acknowledges the NSF support (CBET 1133112).Peer reviewe

Determinantes do desmatamento em pequenas propriedades na Amazônia: um estudo de caso em Uruará - PA

The main objective of this paper was to analyse the factors that influence deforestation in small rural farms of a colonization area in Brazil’s Amazon Region. It was used data from 138 small farms distribuited over the transamazonic road in the municipality of Uruará, PA. The data was collected during july and august of 2002. A Tobit model with sample selectivity with etimation in two stages (Heckman) was used. In the first stage, the probability of deforestation was explained mainly by the presence of cattle in the farm. In the second stage, the deforestation area was modeled as a function of various factors. The results showed that the main determinants of deforestation are the amount paid for lired labor, the distance from the main road, the number of cattle heads and the number of people that live in the lot of land.Brasilian Amazon, Deforestation, Colonization, Tobit model, Environmental Economics and Policy,

Clinical Correlates of Early-Onset Hypertension

BACKGROUNDEarly-onset hypertension has been established as a heritable trait and a risk factor for cardiovascular disease outcomes. However, the clinical correlates of early-onset hypertension remain unidentified.METHODSIn this study, we assessed the demographic characteristics and lifestyle factors related to hypertension onset age in a sample of 3,286 Coronary Artery Risk Development in Young Adults (CARDIA) study participants (mean baseline age 25 4 years, 57% women). We examined the association between the participants' baseline characteristics and age of hypertension onset subgroups (= 45 years) using a multinomial logistic regression model with those who did not develop hypertension as the reference group. Hypertension onset was defined as blood pressure >= 140/90 mm Hg or antihypertensive medication use on 2 consecutively attended follow-up visits.RESULTSIn the multinomial logistic regression model, individuals who were black (odds ratio [OR], 5.08; 95% confidence interval [CI], 3.17-8.14), were more obese (OR, 1.57; 95% CI, 1.32-1.88), or had higher total cholesterol (OR, 1.34; 95% CI, 1.13-1.60 per SD) had increased odds of early-onset hypertension (onset at CONCLUSIONSOur findings suggest that individuals who are black, obese, have higher total cholesterol, or have lower HDL-cholesterol level, are potentially at an increased risk of having early-onset hypertension.</p

Association of Left Ventricular Hypertrophy With Incident Hypertension: The Multi-Ethnic Study of Atherosclerosis

Increased left ventricular (LV) mass and changes in LV geometry may precede hypertension onset. The authors examined the associations of LV mass and geometry, assessed by cardiac magnetic resonance imaging, with hypertension incidence in 2,567 normotensive participants enrolled in 2000–2002 in the Multi-Ethnic Study of Atherosclerosis, an ethnically diverse, population-based, US study. Over a median follow-up of 4.8 years, 745 (29%) participants developed hypertension. In a fully adjusted model including baseline blood pressure, the relative risks of incident hypertension from the lowest to highest LV mass quartile were 1.00 (referent), 1.13 (95% confidence interval (CI): 0.89, 1.43), 1.28 (95% CI: 1.00, 1.63), and 1.78 (95% CI: 1.38, 2.30) (P < 0.001 for linear trend). Higher levels of LV concentric geometry, defined by higher LV mass to end-diastolic volume quartiles, were associated with higher risk of incident hypertension in a fully adjusted model (P = 0.044 for linear trend). In a final model containing both quartiles of LV mass and LV mass/volume along with all covariates including baseline blood pressure, higher LV mass quartiles were associated with incident hypertension (P < 0.001 for linear trend), whereas higher LV mass/volume quartiles were not (P = 0.643 for linear trend). In this multiethnic cohort, alterations in LV mass preceded hypertension onset among normotensive individuals

Associations of Aortic Distensibility and Arterial Elasticity With Long-Term Visit-to-Visit Blood Pressure Variability: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND Although higher visit-to-visit variability (VVV) of blood pressure (BP) is associated with increased cardiovascular disease risk, the physiological basis for VVV of BP is incompletely understood. METHODS We examined the associations of aortic distensibility (assessed by magnetic resonance imaging) and artery elasticity indices (determined by radial artery pulse contour analysis) with VVV of BP in 2,640 and 4,560 participants, respectively, from the Multi-Ethnic Study of Atherosclerosis. Arterial measures were obtained at exam 1. BP readings were taken at exam 1 and at 3 follow-up visits at 18-month intervals (exams 2, 3, and 4). VVV was defined as the SD about each participant’s mean systolic BP (SBP) across visits. RESULTS The mean SDs of SBP were inversely associated with aortic distensibility: 7.7, 9.9, 10.9, and 13.2mm Hg for quartiles 4, 3, 2, and 1 of aortic distensibility, respectively (P trend < 0.001). This association remained significant after adjustment for demographics, cardiovascular risk factors, mean SBP, and antihypertensive medication use (P trend < 0.01). In a fully adjusted model, lower quartiles of large artery and small artery elasticity (LAE and SAE) indices were also associated with higher mean SD of SBP (P trend = 0.02 for LAE; P trend < 0.001 for SAE). CONCLUSIONS In this multiethnic cohort, functional alterations of central and peripheral arteries were associated with greater long-term VVV of SBP