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QT interval length is an important risk factor for adverse cardiovascular outcomes; however, the genetic architecture of QT interval remains incompletely understood. We conducted a genome-wide association study of 76,995 ancestrally diverse Kaiser Permanente Northern California members enrolled in the Genetic Epidemiology Research on Adult Health and Aging cohort using 448,517 longitudinal QT interval measurements, uncovering 9 novel variants, most replicating in 40,537 individuals in the UK Biobank and Population Architecture using Genomics and Epidemiology studies. A meta-analysis of all 3 cohorts (n = 117,532) uncovered an additional 19 novel variants. Conditional analysis identified 15 additional variants, 3 of which were novel. Little, if any, difference was seen when adjusting for putative QT interval lengthening medications genome-wide. Using multiple measurements in Genetic Epidemiology Research on Adult Health and Aging increased variance explained by 163%, and we show that the 6 measurements in Genetic Epidemiology Research on Adult Health and Aging was equivalent to a 2.4 increase in sample size of a design with a single measurement. The array heritability was estimated at 17%, approximately half of our estimate of 36% from family correlations. Heritability enrichment was estimated highest and most significant in cardiovascular tissue (enrichment 7.2, 95% CI= 5.7–8.7, P = 2.1e-10), and many of the novel variants included expression quantitative trait loci in heart and other relevant tissues. Comparing our results to other cardiac function traits, it appears that QT interval has a multifactorial genetic etiology. [ABSTRACT FROM AUTHOR]

Aim Serum C-peptide is an active peptide that has important physiological functions and characteristics in the elderly. The present study aimed to investigate the association between physical activity and serum C-peptide level independent of insulin level among the elderly. Methods The study included 1700 elderly participants aged ≥65 years. Stratified analysis of covariance was used to compare serum C-peptide levels in participants with different physical activity levels. Two separate multiple linear regression models were created to estimate the association between physical activity and serum C-peptide level. Results The results of analysis of covariance stratified by sex, body mass index and serum insulin level showed that those who engaged in vigorous physical activity had lower serum C-peptide levels than those who engaged in light or no physical activity. Separate multiple linear regression analysis showed that in those with low serum C-peptide levels (≤0.621 nmol/L), physical activity was significantly positively associated with the serum C-peptide level. In contrast, physical activity was negatively associated with the serum C-peptide level among those with serum C-peptide level >0.621 nmol/L. Conclusions The serum C-peptide level showed a significant two-way association with physical activity. The present findings suggest that physical activity modification is important for improving serum C-peptide levels among the elderly. Geriatr Gerontol Int 2014; 14: 647-653. [ABSTRACT FROM AUTHOR]

The protein structural entries grew far slower than the sequence entries. This is partly due to the bottleneck in obtaining diffraction quality protein crystals for structural determination using X-ray crystallography. The first step to achieve protein crystallization is to find out suitable chemical reagents. However, it is not an easy task. Exhausting trial and error tests of numerous combinations of different reagents mixed with the protein solution are usually necessary to screen out the pursuing crystallization conditions. Therefore, any attempts to help find suitable reagents for protein crystallization are helpful. In this paper, an analysis of the relationship between the protein sequence similarity and the crystallization reagents according to the information from the existing databases is presented. We extracted information of reagents and sequences from the Biological Macromolecule Crystallization Database (BMCD) and the Protein Data Bank (PDB) database, classified the proteins into different clusters according to the sequence similarity, and statistically analyzed the relationship between the sequence similarity and the crystallization reagents. The results showed that there is a pronounced positive correlation between them. Therefore, according to the correlation, prediction of feasible chemical reagents that are suitable to be used in crystallization screens for a specific protein is possible. [ABSTRACT FROM AUTHOR]

Over the hinterland of the Taklimakan Desert (TD), the diurnal and seasonal cycles of the air temperature (AT) and horizontal sand-dust flux (HSDF) were investigated, based on in situ data including sand saltation counts and meteorological parameters in the period 2008–2010. In particular, the relationship between AT and HSDF was determined. It was found that 74.7% of HSDF was observed between 10:00 and 20:00, and HSDF in spring and summer accounted for 92.3% of the annual flux. Further, the diurnal and annual cycles of HSDF and AT presented an exponential distribution, with correlation coefficients (R) of 0.97 and 0.93, respectively. Additionally, when AT was 0 °C or lower, the frequency of sand saltation was only 4.3%. The maximum sand saltation frequency was 70.1%, which occurred at 33–34 °C, while 67.6% of the total HSDF occurred at 24–34 °C. Finally, a Gauss equation was established over the TD: Q = 250.2 + 1368.5e−2 × [(T−30.8)/7.3]^2, with R = 0.90. Results revealed a strong correlation between HSDF and AT, indicating that AT should be noticeable in HSDF parameterization schemes. [ABSTRACT FROM AUTHOR]

In this study, a new strategy combining mass spectrometric (MS) techniques with partial least squares regression (PLSR) was proposed to identify and quantify closely related adulterant herbal materials. This strategy involved preparation of adulterated samples, data acquisition and establishment of PLSR model. The approach was accurate, sensitive, durable and universal, and validation of the model was done by detecting the presence of Fritillaria Ussuriensis Bulbus in the adulteration of the bulbs of Fritillaria unibracteata. Herein, three different MS techniques, namely wooden-tip electrospray ionization mass spectrometry (wooden-tip ESI/MS), ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) and UPLC-triple quadrupole tandem mass spectrometry (UPLC-TQ/MS), were applied to obtain MS profiles for establishing PLSR models. All three models afforded good linearity and good accuracy of prediction, with correlation coefficient of prediction ( r p 2 ) of 0.9072, 0.9922 and 0.9904, respectively, and root mean square error of prediction (RMSEP) of 0.1004, 0.0290 and 0.0323, respectively. Thus, this strategy is very promising in tracking the supply chain of herb-based pharmaceutical industry, especially for identifying adulteration of medicinal materials from their closely related herbal species. [ABSTRACT FROM AUTHOR]

Objective: Although many studies worldwide have focused on the relationship between vitamin D and insulin resistance, results remain controversial. Furthermore, concentrations of serum 25-hydroxyvitamin D (25(OH)D) in the Chinese population are unclear. We aimed to investigate vitamin D status and its correlation with insulin resistance among a Chinese adult population.Design: Serum 25(OH)D, fasting blood glucose, fasting insulin, glycated Hb (HbA1c) and other metabolic parameters were assessed. Neck circumference, waist circumference, hip circumference, weight and height were also measured. Lifestyle factors including smoking and drinking status were obtained. Diabetes mellitus was diagnosed by HbA1c according to the 2010 American Diabetes Association criteria.Setting: Eastern China.Subjects: Of 7200 residents included, 6597 individuals were ultimately analysed.Results: We enrolled 2813 males (mean age 52·7 (sd 13·5) years) and 3784 females (52·3 (sd 13·5) years); mean serum 25(OH)D concentration was 43·1 (sd 11·6) and 39·6 (sd 9·8) nmol/l, respectively. Additionally, 83·3 % of participants were 25(OH)D deficient. A significant difference in 25(OH)D was observed between males and females in winter and spring (P<0·001). Furthermore, 25(OH)D concentrations were inversely associated with the homeostasis model assessment of insulin resistance (HOMA-IR) in the overweight and pre-diabetic populations. After adjusting for several variables, 25(OH)D was significantly associated with HOMA-IR in winter. When 25(OH)D values were categorized into quartiles, HOMA-IR was significantly associated with decreasing 25(OH)D.Conclusions: The majority of the Chinese population was vitamin D deficient and this deficiency was negatively associated with insulin resistance, particularly in the overweight and pre-diabetic populations. Moreover, these associations might be more evident in the winter. [ABSTRACT FROM AUTHOR]