Size-Dependent Optical Properties of Dendronized Perylenediimide Nanoparticle Prepared by Laser Ablation in Water

Fluorescent nanoparticles of dendronized perylenediimide (DPDI) were fabricated by laser ablation in water. We succeeded in the preparation of colloidal nanoparticles of different sizes (150–400 nm) and examined their size-dependent optical absorption and fluorescence properties. The size-dependent extinction spectra can be explained by the effect of light scattering loss, and it was confirmed that their absorption spectrum is similar to that of molecules in solution. The very weak interchromophoric interaction is also confirmed by fluorescence spectral measurement. On the other hand, we found that the fluorescence quantum yield decreases with decreasing of the particle size, and we propose a new mechanism for the size-dependent reduction of emission intensity in organic nanoparticles. On the basis of the size dependent-fluorescence quantum yield and solvent polarity dependence of DPDI fluorescence in organic solvents, we considered that, while the interchromophoric interactions are weak in the nanoparticle, the excited singlet state migrates in a nanoparticle owing to energy hopping and is quenched at the surface, leading to the observed size-dependent fluorescence quantum yield (Φ_f) and a smaller value of Φ_f for nanoparticles than for the molecules in nonpolar solvents

ABCA1 gene-physical activity interaction for HDL-C

Few studies have investigated the interactions between HDL-C-related SNPs identified by genome-wide association (GWA) study and physical activity (PA) on HDL-C. First, we conducted a sex-stratified GWA study in a discovery sample (2,231 men and 2,431 women) and replication sample (2,599 men and 3,109 women) to identify SNPs influencing log-transformed HDL-C in Japanese participants in the baseline survey of the Japan Multi-Institutional Collaborative Cohort Study. We also replicated previously reported HDL-C-related SNPs in a combined (discovery plus replication) sample (4,830 men and 5,540 women). We then analyzed the interactions of the HDL-C-related SNPs with PA on HDL-C. The sex-stratified GWA analyses identified 11 and 10 HDL-C-related SNPs in men and women as targets for an interaction analysis. Among these, only one interaction of ABCA1 rs1883025 with PA was statistically significant in men, after Bonferroni correction [P-interaction = 0.001 (α = 0.05/21 = 0.002)]. The per-major-allele (C allele) increase in log-transformed HDL-C was lost in men with low PA (β = 0.008) compared with those with medium (β = 0.032) or high PA (β = 0.034). These findings suggest that the benefit of carrying a C allele of ABCA1 rs1883025 on enhancing HDL-C may be attenuated in inactive men

A genome-wide association study in the Japanese population identifies the 12q24 locus for habitual coffee consumption : The J-MICC Study

Coffee is one of the most widely consumed beverages worldwide, and its role in human health has received much attention. Although genome-wide association studies (GWASs) have investigated genetic variants associated with coffee consumption in European populations, no such study has yet been conducted in an Asian population. Here, we conducted a GWAS to identify common genetic variations that affected coffee consumption in a Japanese population of 11,261 participants recruited as a part of the Japan Multi-Institutional Collaborative Cohort (J-MICC) study. Coffee consumption was collected using a self-administered questionnaire, and converted from categories to cups/day. In the discovery stage (n = 6,312), we found 2 independent loci (12q24.12–13 and 5q33.3) that met suggestive significance (P < 1 × 10−6). In the replication stage (n = 4,949), the lead variant for the 12q24.12–13 locus (rs2074356) was significantly associated with habitual coffee consumption (P = 2.2 × 10−6), whereas the lead variant for the 5q33.3 locus (rs1957553) was not (P = 0.53). A meta-analysis of the discovery and replication populations, and the combined analysis using all subjects, revealed that rs2074356 achieved genome-wide significance (P = 2.2 × 10−16 for a meta-analysis). These findings indicate that the 12q24.12-13 locus is associated with coffee consumption among a Japanese population

Development of Risk Prediction Equations for Incident Chronic Kidney Disease

IMPORTANCE ‐ Early identification of individuals at elevated risk of developing chronic kidney disease  could improve clinical care through enhanced surveillance and better management of underlying health  conditions.  OBJECTIVE – To develop assessment tools to identify individuals at increased risk of chronic kidney  disease, defined by reduced estimated glomerular filtration rate (eGFR).  DESIGN, SETTING, AND PARTICIPANTS – Individual level data analysis of 34 multinational cohorts from  the CKD Prognosis Consortium including 5,222,711 individuals from 28 countries. Data were collected  from April, 1970 through January, 2017. A two‐stage analysis was performed, with each study first  analyzed individually and summarized overall using a weighted average. Since clinical variables were  often differentially available by diabetes status, models were developed separately within participants  with diabetes and without diabetes. Discrimination and calibration were also tested in 9 external  cohorts (N=2,253,540). EXPOSURE Demographic and clinical factors.  MAIN OUTCOMES AND MEASURES – Incident eGFR <60 ml/min/1.73 m2.  RESULTS – In 4,441,084 participants without diabetes (mean age, 54 years, 38% female), there were  660,856 incident cases of reduced eGFR during a mean follow‐up of 4.2 years. In 781,627 participants  with diabetes (mean age, 62 years, 13% female), there were 313,646 incident cases during a mean follow‐up of 3.9 years. Equations for the 5‐year risk of reduced eGFR included age, sex, ethnicity, eGFR, history of cardiovascular disease, ever smoker, hypertension, BMI, and albuminuria. For participants  with diabetes, the models also included diabetes medications, hemoglobin A1c, and the interaction  between the two. The risk equations had a median C statistic for the 5‐year predicted probability of  0.845 (25th – 75th percentile, 0.789‐0.890) in the cohorts without diabetes and 0.801 (25th – 75th percentile, 0.750‐0.819) in the cohorts with diabetes. Calibration analysis showed that 9 out of 13 (69%) study populations had a slope of observed to predicted risk between 0.80 and 1.25. Discrimination was  similar in 18 study populations in 9 external validation cohorts; calibration showed that 16 out of 18 (89%) had a slope of observed to predicted risk between 0.80 and 1.25. CONCLUSIONS AND RELEVANCE – Equations for predicting risk of incident chronic kidney disease developed in over 5 million people from 34 multinational cohorts demonstrated high discrimination and  variable calibration in diverse populations

Stress Corrosion Cracking of Amorphous Iron Base Alloys

The stress corrosion cracking behaviour at room temperature of amorphous Fe-Cr-Ni-P-C alloys subjected to constant strain rates was studied in some acidic solutions containing Cl- ions. Hydrogen embrittlement of the alloys occurred in the potential region lower than -300 mV relative to the corrosion potential in acidic solutions regardless of Cl- concentration. In the passive potential region no embrittlement was observed during tests in neutral NaCl solutions and in acidic solutions with low concentrations of Cl- ions. Only when tensile stress was applied to the specimen in relatively strong acidic solutions containing a certain amount of Cl- ions, fracture stress decreased in this potential region. The lowering of the fracture stress can also be attributed to hydrogen embrittlement