Band structure and reflectance for a nonlinear one-dimensional photonic crystal

We consider a model for a one-dimensional photonic crystal formed by a succession of Kerr-type equidistant spaceless interfaces immersed in a linear medium. We calculate the band structure and reflectance of this structure as a function of the incident wave intensity, and find two main behaviors: the appearance of prohibited bands, and the separation and narrowing of these bands. A system with these features is obtained by alternating very thin slabs of a soft matter material with thicker solid films, which can be used to design a device to control light propagation for specific wavelength intervals and light intensities.Comment: 6 pages, 6 figure

Design of 3D Macroporous Inverse Opal TiO2 Binary and Ternary Composites Sensitized with Gold Nanoparticles and CdS Quantum Dots for Photocatalysis

Materials composed of titanium (IV) oxide (TiO2) have received enormous scientific interest due to titania’s abundance, non-toxicity, and photocatalytic proficiency, however its large band gap limits its applicability under ambient conditions. Various attempts have been made to incorporate titania into composite systems to sensitize it for activity under a broader range of wavelengths. One such method includes utilizing narrow band gap semiconductors to form an electron transfer process analogous to photosynthesis referred to as a Z-scheme. Z-scheme systems can catalyze the decomposition of aqueous pollutants via generation of reactive oxygen species after input of sunlight. This work reports the design of a photocatalyst consisting of macroporous inverse opal (io) TiO2 embedded with gold nanoparticles (AuNPs) and cadmium sulfide quantum dots (CdS QDs) into binary and ternary systems. These composites, labeled ioTiO2-Au, ioTiO2-CdS, and ioTiO2-Au-CdS are characterized via SEM, EDX, solid-state UV-vis, and Raman, and are subsequently evaluated for their photocatalytic efficiency against the pollutant analog trypan blue (TryB) under UV and white light LED lighting conditions. It was found that binary ioTiO2-CdS exhibits the best photocatalytic performance, with a rate constant 7.8, 5.2, 6.5, and 1.6 times faster than singular ioTiO2 and CdS, binary ioTiO2-Au, and ternary ioTiO2-Au-CdS under UV, respectively. Under white light LED all systems exhibit reduced activity, with ioTiO2-Au-CdS and ioTiO2-CdS showing no statistical difference, however, the ternary system performed most consistently across both light sources, retaining 92% of its UV performance. Loss of CdS due to photocorrosion limits recyclability of the thin films

The Mediterranean diet protects against waist circumference enlargement in 12Ala carriers for the PPARgamma gene: 2 years' follow-up of 774 subjects at high cardiovascular risk.

The PPARgamma gene regulates insulin sensitivity and adipogenesis. The Pro12Ala polymorphism of this gene has been related to fat accumulation. Our aim was to analyse the effects of a 2-year nutritional intervention with Mediterranean-style diets on adiposity in high-cardiovascular risk patients depending on the Pro12Ala polymorphism of the PPARgamma gene. The population consisted of a substudy (774 high-risk subjects aged 55-80 years) of the Prevención con Dieta Mediterránea (PREDIMED) randomised trial aimed at assessing the effect of the Mediterranean diet for CVD prevention. There were three nutritional intervention groups: two of them of a Mediterranean-style diet and the third was a control group advised to follow a conventional low-fat diet. All the participants were genotyped by PCR-restriction fragment length polymorphism (RFLP). The results showed that carriers of the 12Ala allele allocated to the control group had a statistically significant higher change in waist circumference (adjusted difference coefficient = 2.37 cm; P = 0.014) compared with wild-type subjects after 2 years of nutritional intervention. This adverse effect was not observed among 12Ala carriers allocated to both Mediterranean diet groups. In diabetic patients a statistically significant interaction between Mediterranean diet and the 12Ala allele regarding waist circumference change was observed ( - 5.85 cm; P = 0.003). In conclusion, the Mediterranean diet seems to be able to reduce waist circumference in a high-cardiovascular risk population, reversing the negative effect that the 12Ala allele carriers of the PPARgamma gene appeared to have. The beneficial effect of this dietary pattern seems to be higher among type 2 diabetic subjects

Selection bias due to conditioning on a collider

Effect estimates may be biased when the study design or the data analysis is conditional on a collider—a variable that is caused by two other variables. Causal directed acyclic graphs are a helpful tool to identify colliders that may introduce selection bias in observational research.S

Was there a common hydrological pattern in the Iberian Peninsula region during the medieval Climate anomaly?

Climate variability reconstructions for the last millennium from several Iberian lake and marine records shed light on the spatial and temporal hydroclimate and associated climate mechanisms during the Medieval Climate Anomaly

Olive oil intake and risk of cardiovascular disease and mortality in the PREDIMED Study

Background: It is unknown whether individuals at high cardiovascular risk sustain a benefit in cardiovascular disease from increased olive oil consumption. The aim was to assess the association between total olive oil intake, its varieties (extra virgin and common olive oil) and the risk of cardiovascular disease and mortality in a Mediterranean population at high cardiovascular risk. Methods: We included 7,216 men and women at high cardiovascular risk, aged 55 to 80 years, from the PREvención con DIeta MEDiterránea (PREDIMED) study, a multicenter, randomized, controlled, clinical trial. Participants were randomized to one of three interventions: Mediterranean Diets supplemented with nuts or extra-virgin olive oil, or a control low-fat diet. The present analysis was conducted as an observational prospective cohort study. The median follow-up was 4.8 years. Cardiovascular disease (stroke, myocardial infarction and cardiovascular death) and mortality were ascertained by medical records and National Death Index. Olive oil consumption was evaluated with validated food frequency questionnaires. Multivariate Cox proportional hazards and generalized estimating equations were used to assess the association between baseline and yearly repeated measurements of olive oil intake, cardiovascular disease and mortality. Results: During follow-up, 277 cardiovascular events and 323 deaths occurred. Participants in the highest energy-adjusted tertile of baseline total olive oil and extra-virgin olive oil consumption had 35% (HR: 0.65; 95% CI: 0.47 to 0.89) and 39% (HR: 0.61; 95% CI: 0.44 to 0.85) cardiovascular disease risk reduction, respectively, compared to the reference. Higher baseline total olive oil consumption was associated with 48% (HR: 0.52; 95% CI: 0.29 to 0.93) reduced risk of cardiovascular mortality. For each 10 g/d increase in extra-virgin olive oil consumption, cardiovascular disease and mortality risk decreased by 10% and 7%, respectively. No significant associations were found for cancer and all-cause mortality. The associations between cardiovascular events and extra virgin olive oil intake were significant in the Mediterranean diet intervention groups and not in the control group. Conclusions: Olive oil consumption, specifically the extra-virgin variety, is associated with reduced risks of cardiovascular disease and mortality in individuals at high cardiovascular risk. Trial registration This study was registered at controlled-trials.com (http://www.controlled-trials.com/ISRCTN35739639). International Standard Randomized Controlled Trial Number (ISRCTN): 35739639. Registration date: 5 October 2005

Impact of Consuming Extra-Virgin Olive Oil or Nuts within a Mediterranean Diet on DNA Methylation in Peripheral White Blood Cells within the PREDIMED-Navarra Randomized Controlled Trial: A Role for Dietary Lipids

DNA methylation could be reversible and mouldable by environmental factors, such as dietary exposures. The objective was to analyse whether an intervention with two Mediterranean diets, one rich in extra-virgin olive oil (MedDiet + EVOO) and the other one in nuts (MedDiet + nuts), was influencing the methylation status of peripheral white blood cells (PWBCs) genes. A subset of 36 representative individuals were selected within the PREvención con DIeta MEDiterránea (PREDIMED-Navarra) trial, with three intervention groups in high cardiovascular risk volunteers: MedDiet + EVOO, MedDiet + nuts, and a low-fat control group. Methylation was assessed at baseline and at five-year follow-up. Ingenuity pathway analysis showed routes with differentially methylated CpG sites (CpGs) related to intermediate metabolism, diabetes, inflammation, and signal transduction. Two CpGs were specifically selected: cg01081346–CPT1B/CHKB-CPT1B and cg17071192–GNAS/GNASAS, being associated with intermediate metabolism. Furthermore, cg01081346 was associated with PUFAs intake, showing a role for specific fatty acids on epigenetic modulation. Specific components of MedDiet, particularly nuts and EVOO, were able to induce methylation changes in several PWBCs genes. These changes may have potential benefits in health; especially those changes in genes related to intermediate metabolism, diabetes, inflammation and signal transduction, which may contribute to explain the role of MedDiet and fat quality on health outcomes

Polyphenol intake and mortality risk: a re-analysis of the PREDIMED trial

Background: Polyphenols may lower the risk of cardiovascular disease (CVD) and other chronic diseases due to their antioxidant and anti-inflammatory properties, as well as their beneficial effects on blood pressure, lipids and insulin resistance. However, no previous epidemiological studies have evaluated the relationship between the intake of total polyphenols intake and polyphenol subclasses with overall mortality. Our aim was to evaluate whether polyphenol intake is associated with all-cause mortality in subjects at high cardiovascular risk. Methods: We used data from the PREDIMED study, a 7,447-participant, parallel-group, randomized, multicenter, controlled five-year feeding trial aimed at assessing the effects of the Mediterranean Diet in primary prevention of cardiovascular disease. Polyphenol intake was calculated by matching food consumption data from repeated food frequency questionnaires (FFQ) with the Phenol-Explorer database on the polyphenol content of each reported food. Hazard ratios (HR) and 95% confidence intervals (CI) between polyphenol intake and mortality were estimated using time-dependent Cox proportional hazard models. Results: Over an average of 4.8 years of follow-up, we observed 327 deaths. After multivariate adjustment, we found a 37% relative reduction in all-cause mortality comparing the highest versus the lowest quintiles of total polyphenol intake (hazard ratio (HR) = 0.63; 95% CI 0.41 to 0.97; P for trend = 0.12). Among the polyphenol subclasses, stilbenes and lignans were significantly associated with reduced all-cause mortality (HR =0.48; 95% CI 0.25 to 0.91; P for trend = 0.04 and HR = 0.60; 95% CI 0.37 to 0.97; P for trend = 0.03, respectively), with no significant associations apparent in the rest (flavonoids or phenolic acids). Conclusions: Among high-risk subjects, those who reported a high polyphenol intake, especially of stilbenes and lignans, showed a reduced risk of overall mortality compared to those with lower intakes. These results may be useful to determine optimal polyphenol intake or specific food sources of polyphenols that may reduce the risk of all-cause mortality. Clinical trial registration ISRCTN35739639

A Polymorphism in a Gene Encoding Perilipin 4 Is Associated with Height but not with Bone Measures in Individuals from the Framingham Osteoporosis Study

There is increasing interest in identifying new pathways and candidate genes that confer susceptibility to osteoporosis. There is evidence that adipogenesis and osteogenesis may be related, including a common bone marrow progenitor cell for both adipocytes and osteoblasts. Perilipin 1 (PLIN1) and Perilipin 4 (PLIN4) are members of the PATS family of genes and are involved in lipolysis of intracellular lipid deposits. A previous study reported gender-specific associations between one polymorphism of PLIN1 and bone mineral density (BMD) in a Japanese population. We hypothesized that polymorphisms in PLIN1 and PLIN4 would be associated with bone measures in adult Caucasian participants of the Framingham Osteoporosis Study (FOS). We genotyped 1,206 male and 1,445 female participants of the FOS for four single-nucleotide polymorphism (SNPs) in PLIN1 and seven SNPs in PLIN4 and tested for associations with measures of BMD, bone ultrasound, hip geometry, and height. We found several gender-specific significant associations with the measured traits. The association of PLIN4 SNP rs8887, G>A with height in females trended toward significance after simulation testing (adjusted P = 0.07) and remained significant after simulation testing in the combined-sex model (adjusted P = 0.033). In a large study sample of men and women, we found a significant association between one SNP in PLIN4 and height but not with bone traits, suggesting that PATS family genes are not important in the regulation of bone. Identification of genes that influence human height may lead to a better understanding of the processes involved in growth and development

Lifestyles and risk factors associated with adherence to the Mediterranean diet: a baseline assessment of the PREDIMED Trial

Background: The traditional Mediterranean dietary pattern (MedDiet) is associated with longevity and low rates of cardiovascular disease (CVD). However, there is little information on who is more likely to follow this food pattern. Aim: To evaluate how different factors are associated with lower MedDiet adherence in older Spanish subjects. Methods: We included 7305 participants (men aged 55-80 y, women 60-80 y) at high-risk of CVD recruited into the PREDIMED trial (ISRCTN35739639). Socioeconomic, anthropometric, lifestyle characteristics and CVD risk factors were recorded. A validated 14-item questionnaire was used to evaluate MedDiet adherence at baseline. Multivariate models were used to estimate odds ratios (OR) and 95% confidence intervals for lower adherence to the MedDiet (<9 points out of 14) and ascertain factors independently associated with it. Results: Former smoking (OR = 0.87; 95% CI, 0.78-0.98), physical activity (OR for the 3rd vs. the 1sttertile: 0.69; 0.62-0.78), and higher educational level (OR for university vs. less than primary school: 0.54; 0.38-0.77) were associated with higher MedDiet adherence. Conversely, having a larger waist-to-height ratio (OR for 0.1 units, 1.35; 1.22-1.49), being diabetic (OR = 1.13; 1.03-1.24), being single (OR = 1.27; 1.01-1.61) or divorced or separated (OR = 1.44; 1.09-1.89), and current smoking (OR = 1.28; 1.11-1.47) were associated with lower adherence. Conclusions: Participants with little education, a larger waist-to-height ratio, or diabetes and those who were less physically active, single, divorced or separated, or smokers were less likely to adhere to the MedDiet, an ideal model for food choices. Stronger efforts of health promotion are needed in these groups to foster adoption of the MedDiet