Shape and morphology of polymeric particles are of great importance in controlling their optical properties or self-assembly into unusual superstructures. Confinement of block copolymers (BCPs) in evaporative emulsions affords particles with diverse structures, including prolate ellipsoids, onion-like spheres, oblate ellipsoids, and others. Herein, we report that the evaporation rate of solvent from emulsions encapsulating symmetric polystyrene-b-polybutadiene (PS-b-PB) determines the shape and internal nanostructure of micron-sized BCP particles. A distinct morphological transition from the ellipsoids with striped lamellae to the onion-like spheres was observed with decreasing evaporation rate. Experiments and dissipative particle dynamics (DPD) simulations showed that the evaporation rate affected the organization of BCPs at the particle surface, which determined the final shape and internal nanostructure of the particles. Differences in the solvent diffusion rates in PS and PB at rapid evaporation rates induced alignment of both domains perpendicular to the particle surface, resulting in ellipsoids with axial lamellar stripes. Slower evaporation rates provided sufficient time for BCP organization into onion-like structures with PB as the outermost layer, owing to the preferential interaction of PB with the surroundings. BCP molecular weight was found to influence the critical evaporation rate corresponding to the morphological transition from ellipsoid to onion-like particles, as well as the ellipsoid aspect ratio. DPD simulations produced morphologies similar to those obtained from experiments and thus elucidated the mechanism and driving forces responsible for the evaporation-induced assembly of BCPs into particles with well-defined shapes and morphologies.

The paradigm shift in dye sensitized solar cells (DSCs) – towards donor- π bridge-acceptor (D-π-A) dyes – increases the performances of DSCs and challenges established design principles. Framed by this shifting landscape, a series of four diketopyrrolopyrrole (DPP)-based sensitizers utilizing the donor-chromophore-anchor (D-C-A) motif were investigated computationally, spectroscopically, and fabricated by systematic evaluation of finished photovoltaic cells. In all cases, the [Co(bpy)3]3+/2+ redox-shuttle afforded superior performance compared to I3−/I−. Aesthetically, careful molecular engineering of the DPP chromophore yielded the first example of a high-performance blue DSC – a challenge unmet since the inception of this photovoltaic technology: DPP17 yields over 10% power conversion efficiency (PCE) with the [Co(bpy)3]3+/2+ electrolyte at full AM 1.5 G simulated sun light.

BackgroundThe association between body mass index (BMI) and cognitive function is a public health issue. This study investigated the relationship between obesity and cognitive impairment which was assessed by the Korean version of the Mini-mental state examination (K-MMSE) among mid- and old-aged people in South Korea.MethodsA cohort of 5,125 adults, age 45 or older with normal cognitive function (K-MMSE≥24) at baseline (2006), was derived from the Korean Longitudinal Study of Aging (KLoSA) 2006~2012. The association between baseline BMI and risk of cognitive impairment was assessed using multiple logistic regression models. We also assessed baseline BMI and change of cognitive function over the 6-year follow-up using multiple linear regressions.ResultsDuring the follow-up, 358 cases of severe cognitive impairment were identified. Those with baseline BMI≥25 kg/m2 than normal-weight (18.5≤BMI<23 kg/m2) were marginally less likely to experience the development of severe cognitive impairment (adjusted odds ratio [aOR] = 0.73, 95% CI = 0.52 to 1.03; Ptrend = 0.03). This relationship was stronger among female (aOR = 0.63, 95% CI = 0.40 to 1.00; Ptrend = 0.01) and participants with low-normal K-MMSE score (MMSE: 24–26) at baseline (aOR = 0.59, 95% CI = 0.35 to 0.98; Ptrend<0.01). In addition, a slower decline of cognitive function was observed in obese individuals than those with normal weight, especially among women and those with low-normal K-MMSE score at baseline.ConclusionIn this nationally representative study, we found that obesity was associated with lower risk of cognitive decline among mid- and old-age population.

A novel, asymmetric DPP bridge/core was synthesized and tested in DSC devices. By desymmetrising the DPP core/bridge, a remarkable IPCE of >80% and a maximum power conversion efficiency of 7.7% were achieved. With the use of a wide-bandgap co-sensitizer, 8.6% PCE was realized under standard AM1.5G sunlight.

Epidemiologic studies have shown inconsistent conclusions about the effect of caffeine intake during pregnancy on the risk of low birth weight (LBW). We performed a meta-analysis and linear-dose response analysis examining the association between caffeine consumption during pregnancy and risk of LBW. PubMed and EMBASE were searched for relevant articles published up to March 2014. Eight cohort and four case-control studies met all inclusion criteria. Using a random-effects model of the twelve studies, the pooled odds ratio (OR) for the risk of LBW comparing the highest versus lowest level of caffeine intake during pregnancy was 1.38 (95% CI: 1.10, 1.73). Linear dose-response analysis showed that every additional 100 mg of caffeine intake (1 cup of coffee or 2 cups of tea) per day during pregnancy was associated with a 3.0% increase in OR for LBW. There was a moderate level of overall heterogeneity with an I-squared value of 55% (95% CI: 13, 76%), and no evidence of publication bias based on Egger’s test (P = 0.20) and the funnel plot. Thus, high caffeine intake during pregnancy is associated with a significant increase in the risk of LBW, and this risk appears to increase linearly as caffeine intake increases.

Classification of PAPs on the basis of angiographic findings and determination of treatment options according to these findings are useful for the endovascular management of PAPs associated with massive hemoptysis.

Background In contemporary Western settings, higher occupational class is associated with lower risk for cardiovascular disease ( CVD ) incidence, including coronary heart disease ( CHD ) and stroke. However, in non‐Western settings (including Japan), the occupational class gradient for cardiovascular disease risk has not been characterized. Methods and Results Using a nationwide, multicenter hospital inpatient data set (1984–2016) in Japan, we conducted a matched hospital case‐control study with ≈1.1 million study subjects. Based on a standard national classification, we coded patients according to their longest‐held occupational class (blue‐collar, service, professional, manager) within each industrial sector (blue‐collar, service, white‐collar). Using blue‐collar workers in blue‐collar industries as the referent group, odds ratios and 95% CI s were estimated by conditional logistic regression with multiple imputation, matched for sex, age, admission date, and admitting hospital. Smoking and drinking were additionally controlled. Higher occupational class (professionals and managers) was associated with excess risk for CHD . Even after controlling for smoking and drinking, the excess odds across all industries remained significantly associated with CHD , being most pronounced among managers employed in service industries (odds ratio, 1.19; 95% CI , 1.08–1.31). On the other hand, the excess CHD risk in higher occupational class was offset by their lower risk for stroke (eg, odds ratio for professionals in blue‐collar industries, 0.77; 95% CI , 0.70–0.85). Conclusions The occupational “gradient” in cardiovascular disease (with lower risk observed in higher status occupations) may not be a universal phenomenon. In contemporary Japanese society, managers and professionals may experience higher risk for CHD .

Conjugated polymer-based block copolymers (BCPs) offer great potential to provide beneficial nanostructures for efficient organic optoelectronics. However, their complicated self-assembly behavior, which is attributed to the strong crystallization of conjugated blocks, is still not well understood due to the lack of a model BCP system. Herein, we develop a series of novel conjugated polymer-based BCPs, poly­(3-hexyl­thiophene)-block-poly­(2-vinylpyridine) (P3HT-b-P2VP), in which the regioregularity (RR) of the P3HT block was varied from 95 to 73%. The tunable RR content allows for precise regulation of P3HT crystallization with minimal influence on the microphase-separation force between the P3HT and P2VP blocks. When RR is high (i.e., 95 or 85%), structure formation is controlled by crystallization of P3HT, and the ultimate structure is characterized by nanoscale P3HT fibrils in an amorphous matrix. In contrast, as RR decreases to 78 and 73%, P3HT crystallization is suppressed. The self-assembly is controlled by the enthalpic interaction between P3HT and P2VP blocks, much like typical BCPs having two flexible blocks, and thermal annealing drives the formation of well-ordered lamellar or cylindrical phases. This morphological behavior is consistent with a Monte Carlo simulation based on a newly developed coarse-grained model. Significantly, this novel class of RR-controlled P3HT-based BCPs provides a simple method to tune bulk and thin film morphology for a variety of applications in nanostructured organic electronics.