Publications

Introduction: The 2015-2020 Dietary Guidelines for Americans (DGAs) recommend three major healthy dietary patterns: the Healthy US-Style Eating Pattern, the Healthy Mediterranean-Style Eating Pattern, and the Healthy Vegetarian Eating Pattern, for all Americans with diverse cultural and personal food traditions. However, few studies have systematically examined the potential differences in associations of adherence to these recommended dietary patterns with long-term risk of cardiovascular disease (CVD). Hypothesis: We hypothesized that all three DGA-recommended dietary patterns were associated with lower risk of CVD, coronary heart disease (CHD), and stroke. Method: We evaluated data on 74 661 women in the Nurses’ Health Study (NHS), 90 864 women in NHS II, and 41 837 men in the Health Professionals Follow-Up Study (HPFS), who had repeated dietary data and had no history of type 2 diabetes, CVD, or cancer at baseline. Using the food and nutrient components, we calculated the Healthy Eating Index (HEI)-2015, Alternate Mediterranean Diet score (AMED), Healthful Plant-based Diet Index (HPDI), to measure adherence to the Healthy US-Style Eating Pattern, Healthy Mediterranean-Style Eating Pattern, and Healthy Vegetarian Eating Pattern, respectively. Multivariable Cox proportional-hazards regression was used to assess the associations of healthy eating index with CVD risk. Results: We documented 9 262 incident CVD cases (6 628 CHD and 2 701 stroke) during 1 976 026 person years of follow-up in the NHS, 1 916 CVD cases (1 267 CHD and 660 stroke) during 2 173 162 person years of follow-up in NHS II, and 10 203 CVD cases (8 750 CHD and 1 775 stroke) during 873 053 person years of follow-up in HPFS. When comparing the highest to the lowest quintiles, the pooled HRs (95% CIs) of CVD were 0.80 (0.77 to 0.84) for HEI-2015, 0.83 (0.79 to 0.87) for AMED, and 0.85 (0.81 to 0.89) for HPDI (all P for trend <0.001). In addition, a 25-percentile increase in healthy eating scores was associated with 10% to 22% lower risk of CVD (pooled HR: HEI-2015, 0.78 [0.75 to 0.82]; AMED, 0.90 [0.88 to 0.92]; HPDI, 0.84 [0.81 to 0.88]). For CHD, the pooled HRs (95% CIs) per 20-percentile increase were 0.76 (0.73 to 0.80) for HEI-2015, 0.90 (0.87 to 0.92) for AMED, and 0.83 (0.79 to 0.87) for HPDI. For stroke, the pooled HRs (95% CIs) per 20-percentile increase were 0.86 (0.78 to 0.94) for HEI-2015, 0.90 (0.85 to 0.95) for AMED, and 0.90 (0.83 to 0.98) for HPDI. The inverse associations between healthy eating index and CVD risk persisted in analyses stratified by potential risk factors. Conclusions: In three large prospective cohorts with up to 32 years of follow-up, higher adherence to various healthy eating patterns was associated with lower risk of CVD, CHD, and stroke. Our findings support the DGA recommendations for multiple healthy eating patterns.

Reliable modelling of fracture on a structural scale restricts the type of the finite elements used in the analyses to shell elements with in-plane dimension larger than the thickness. Thus, we consider a comprehensive constitutive formulation embedded in the shell mechanics framework. We propose a three-invariant plasticity model that accounts for dependence of the strain at fracture on both stress triaxiality and the third invariant of the deviatoric stress, which has a significant influence for shear-dominated stress states. This is achieved through a phenomenological damage evolution equation that includes both the dilatational term and plastic deviatoric energy term. The latter is dependent on the omega parameter, which can be considered a normalization of the Lode angle. A consistent calibration procedure is also developed based on a small number of carefully selected coupon-level experimental tests.

Abstract Maternal smoking during pregnancy is associated with adverse offspring health outcomes across their life course. We hypothesize that DNA methylation is a potential mediator of this relationship. To test this, we examined the association of prenatal maternal smoking with DNA methylation in 2,821 individuals (age 16 to 48 years) from five prospective birth cohort studies and perform Mendelian randomization and mediation analyses to assess, whether methylation markers have causal effects on disease outcomes in the offspring. We identify 69 differentially methylated CpGs in 36 genomic regions (P < 1×10 −7 ), and show that DNA methylation may represent a biological mechanism through which maternal smoking is associated with increased risk of psychiatric morbidity in the exposed offspring.

This letter describes the formation of two-dimensional (2D) crystals of dipolar particles (TN) made of electrostatically charged, joined, millimeter-scale Teflon (T) and nylon-6,6 (N) spheres, and the separation of these crystals, as a distinct phase, from a mixture of TN and similar, capacitively charged particles that were coated with gold (Au2). The extent of separation increased with increasing amplitude of agitation, and with decreasing density of particles. Above a threshold in the amplitude of agitation, the crystals broke apart and the particles remixed. This system is a 2D model of the nucleation of crystals of polar molecules in a polarizable liquid.

The hemochromatosis gene (HFE) has been involved in the etiology of type 2 diabetes mellitus and investigated in numerous epidemiologic studies. The current meta-analysis was conducted to evaluate the gene-disease association in relevant studies. Electronic literature search was performed on June 18, 2011, from databases of PubMed/MEDLINE, EMBASE, and HuGE Navigator. Articles were inspected by 2 authors independently, and data were extracted by identical extraction form. A total of 5,528 type 2 diabetes cases and 6,920 controls in relation to HFE polymorphisms (a cysteine to tyrosine substitution at amino acid position 282 (C282Y) and a histidine to aspartate substitution at amino acid position 63 (H63D)) were included in the meta-analysis (1997-2011). A fixed- or random-effect model was used to calculate the pooled odds ratios based on the results from the heterogeneity tests. An increased odds ratio for type 2 diabetes mellitus was observed in persons carrying a D allele at the H63D polymorphism compared with those with an H allele (odds ratio (OR) = 1.21, 95% confidence interval (CI): 1.03, 1.41; P = 0.02). Moreover, carriers of a D allele had a modestly increased risk compared with persons with the wild genotype (OR = 1.12, 95% CI: 1.00, 1.25; P = 0.04). The C282Y variant was not significantly associated with diabetes risk. In summary, persons with a D allele may have a moderately increased risk of type 2 diabetes mellitus.

This paper describes torque-actuated valves for controlling the flow of fluids in microfluidic channels. The valves consist of small machine screws (≥500 μm) embedded in a layer of polyurethane cast above microfluidic channels fabricated in poly(dimethylsiloxane) (PDMS). The polyurethane is cured photochemically with the screws in place; on curing, it bonds to the surrounding layer of PDMS and forms a stiff layer that retains an impression of the threads of the screws. The valves were separated from the ceiling of microfluidic channels by a layer of PDMS and were integrated into channels using a simple procedure compatible with soft lithography and rapid prototyping. Turning the screws actuated the valves by collapsing the PDMS layer between the valve and channel, controlling the flow of fluids in the underlying channels. These valves have the useful characteristic that they do not require power to retain their setting (on/off). They also allow settings between "on" and "off" and can be integrated into portable, disposable microfluidic devices for carrying out sandwich immunoassays.

This paper describes a new method of reducing the size of the metal features made by electroless deposition, and a new method to fabricate complex shaped, patterned surfaces. Microcontact printing ({mu}CP) was used to pattern oriented glassy polymers with tetraoctadecylammonium bromide stabilized palladium colloids that serve as catalysts for the selective electroless deposition of copper. Annealing of the activated polymer at a temperature slightly above its glass transition temperature led to a shrinkage of the substrate. Immersion of the shrunken substrate in the plating bath yielded the metal features. The maximum shrinkage of the feature size achieved was in the order of a factor of {approximately}4 in one direction of the oriented polymer and of {approximately}7 in the perpendicular direction. Control of the extent and direction of shrinkage allowed the fabrication of metal features with sizes and shapes different from those on the PDMS stamp used for the patterning of the substrate and from the draw ratios. Free standing metal structures were produced by dissolving the substrate after the metal film had reached the desired thickness. Complex shaped, patterned surfaces could be fabricated by wrapping the activated polymer film around a scaffolding; during the annealing, the polymer adapted the shapemore » of the underlying scaffolding. Metallization of the activated, shaped substrate resulted in patterned three dimensional structures.« less

Small, 3D, polyhedral structures based on existing 2D microfabrication technology have been fabricated by a novel technique. The method is based on self-folding of a 2D structure into the final 3D form due to the surface tension of solder, which covers the joints. Patterned polyhedra (see Figure) and structures with silicon single crystal chips on each face are accessible.

We discuss how resonance micro-Raman spectroscopy can determine the electronic and structural properties of individual isolated single-wall carbon nanotubes (SWNTs) that can be further used for potential nanodevices or studied by different experimental techniques. We show that it is possible to mark the surface of the Si/SiO2 substrate for localization of the isolated SWNTs by using a diamond tip. By timing the growth procedure, a low density of SWNTs on the substrate can be obtained so that the SWNT localization by atomic force microscopy (AFM) is trivial. We also characterize a SWNT by resonance Raman spectroscopy at the edge of a Si-SWNT-AFM tip. There results show that it is possible to make joint experiments on the same isolated SWNT.

A mid-infrared sensor for label-free on-chip chemical detection was developed using an engineered nanofluidic channel consisting of a Si-liquid-Si slot-structure. A sensitivity with 75 times improvement was achieved compared to conventional evanescent-wave sensing.

Background-Smoking is an important cardiovascular disease risk factor, but the mechanisms linking smoking to blood pressure are poorly understood. Methods and Results-Data on 141 317 participants (62 666 never, 40 669 former, 37 982 current smokers) from 23 population-based studies were included in observational and Mendelian randomization meta-analyses of the associations of smoking status and smoking heaviness with systolic and diastolic blood pressure, hypertension, and resting heart rate. For the Mendelian randomization analyses, a genetic variant rs16969968/rs1051730 was used as a proxy for smoking heaviness in current smokers. In observational analyses, current as compared with never smoking was associated with lower systolic blood pressure and diastolic blood pressure and lower hypertension risk, but with higher resting heart rate. In observational analyses among current smokers, 1 cigarette/day higher level of smoking heaviness was associated with higher (0.21 bpm; 95% confidence interval 0.19; 0.24) resting heart rate and slightly higher diastolic blood pressure (0.05 mm Hg; 95% confidence interval 0.02; 0.08) and systolic blood pressure (0.08 mm Hg; 95% confidence interval 0.03; 0.13). However, in Mendelian randomization analyses among current smokers, although each smoking increasing allele of rs16969968/rs1051730 was associated with higher resting heart rate (0.36 bpm/allele; 95% confidence interval 0.18; 0.54), there was no strong association with diastolic blood pressure, systolic blood pressure, or hypertension. This would suggest a 7 bpm higher heart rate in those who smoke 20 cigarettes/day. Conclusions-This Mendelian randomization meta-analysis supports a causal association of smoking heaviness with higher level of resting heart rate, but not with blood pressure. These findings suggest that part of the cardiovascular risk of smoking may operate through increasing resting heart rate.