Search

In order to observe meso-destruction process of coal in real-time, CT scan test on coal bearing uni-axial compression was implemented in State Key Laboratory of China University of Mining and Technology (Beijing). CT images were analyzed based on the fractal theory. Fractal dimension of CT images which include indications of crack expansion and rupture process of coal samples were calculated. Calculation result shows that the changing trend of CT images' fractal dimension with the stress matches the one of stress-strain curve obtained from the coal uni-axial compression test. It also indicates that the half-Gauss function could well describe the variation of fractal dimension with the change of coal loading under uni-axial compression CT test. The results of this research have important significance for providing intuitive observation data on coal meso-damage model and evaluating the performance of coal materials. [ABSTRACT FROM AUTHOR]

• White blood cell count mediates the relationship between depression and all-cause mortality among the elderly. • This study was the first to examine whether white blood cell count meditated the depression-death association. • Mediation analysis is used to test the potential mechanism between two variables and whether mediator affects the relationship. One possible pathway by which depressive symptoms influence all-cause mortality is through their relationship with markers of inflammatory response. We aimed to examine whether white blood cell (WBC) count mediated the relationship between the presence of depressive symptoms and all-cause mortality among older Chinese people. This community-based cohort study targeted 4053 individuals aged 60 years or over. A bootstrapping approach was applied to examine whether WBC count mediated the relationship between the presence of depressive symptoms and all-cause mortality. WBC count was evaluated as a mediator. The presence of depressive symptoms was assessed by the nine-item Patient Health Questionnaire (PHQ-9). The mediating effect was considered significant if the 95% confidence interval (CI) did not include 0. Mediation analysis indicated that WBC count played an important mediating role in the relationship between PHQ-9 score and all-cause mortality based on the significance of indirect effect (β = -0.0039, 95% CI = -0.01, -0.0009). The direct effect from PHQ-9 score to all-cause mortality was not statistically significant (P = 0.11) after adjusting for WBC count. WBC count was associated with depressive symptoms and all-cause mortality. The association of depressive symptoms with all-cause mortality was fully mediated by WBC count. [ABSTRACT FROM AUTHOR]

• Elevated neutrophil to lymphocyte ratio was associated with an increased risk of cognitive impairment. • Adding neutrophil to lymphocyte ratio to a conventional risk factor model did not increase the predictive value of cognitive impairment. • Whether neutrophil to lymphocyte ratio may act as a clinically relevant predictor for cognitive impairment is unclear. Previous studies have assessed the association of neutrophil to lymphocyte ratio (NLR) with cognitive impairment (COI) in clinical settings. Whether NLR is associated with COI among free-living seniors at population level remains unknown. We aimed to assess the relationship between NLR and COI among community-dwelling older adults and the predictive value of NLR for COI screening in the community. Data of 4579 older adults aged 60 or older in Weitang Geriatric Diseases study, a community-based cross-sectional study conducted in Suzhou located in the east part of China, were analyzed. The NLR was calculated as the absolute neutrophil count divided by the absolute lymphocyte count. Cognitive function of the participants was assessed using the Abbreviated Mental Test. Compared to those in the first quartile of NLR, older adults in the 4th quartile of NLR had a greater risk of COI (odds ratio = 1.34, 95 % confidence interval = 1.06–1.69). Elevated NLR quartile was associated with increasing risk of COI (p value for trend = 0.02). Addition of NLR to the conventional risk factors model could improve the correct reclassification of COI about 9.0 % (p = 0.02) and integrated discrimination improvement value was 0.0012 (p = 0.09). We found that elevated NLR was associated with an increased risk of COI and whether NLR may act as a clinically relevant predictor for COI among community-dwelling older adults could not be determined. [ABSTRACT FROM AUTHOR]

Purpose: Our aim was to investigate the association between sleep and the development of metabolic syndrome (MetS) in Chinese older adults and to accumulate evidence for the prevention of MetS through sleep management.Methods: This prospective study followed 3005 participants aged over 60 derived from the Weitang Geriatric Diseases Study who were without MetS at baseline. MetS was defined according to the Adult Treatment Panel III (ATP III) criteria. Logistic regression models were fit to assess the association between sleep and MetS incident and a linear regression model was used to examine the impact of sleep duration on every component of MetS. Data on sleep-related parameters were obtained based on a self-reported questionnaire.Results: After five-year follow-up, 13.51% participants developed MetS, of which 46.86% were women. The incidence of MetS was highest among adults who slept 6 h or less and lowest among those who slept 7 h after adjusted for multiple variables. Subgroup analyses showed no gender specificity. The variation of fasting plasma glucose (FBG) for ≥9 h per night was significantly lower than that for 7.01-7.99 h per night (β = -0.18, P < 0.05). Sleeping for 8-8.99 h also decreased the variation of diastolic blood pressure (DBP) compared to 7.01-7.99 h (β = -0.84, P < 0.05).Conclusion: We conclude that both short and long sleep duration are risk factors for MetS incident in older adults. [ABSTRACT FROM AUTHOR]

Purpose: There is a lack of data on the role of sleep in the development of metabolic syndrome (MetS) in older adults. We aimed to examine the associations of sleep durations at night and other sleep-related parameters with the presence of MetS in older Chinese adults., Methods: Data of 4579 individuals aged 60 years or older from the Weitang Geriatric Disease Study were analyzed. MetS was diagnosed based on the Adult Treatment Panel III (ATP III) criteria. Information regarding sleep durations and other sleep-related parameters was collected by questionnaires., Results: Compared with those with daytime napping, individuals without daytime napping were at an increased risk of MetS (odds ratio [OR] = 1.23; 95% confidence interval [CI] = 1.03-1.47). Each hour increase in daytime napping increased the risk of MetS by 33% (OR = 1.33; 95% CI = 1.15-1.52). After adjusting for the effect of age and gender, a J-shaped association between sleep durations at night and the presence of MetS was observed. The risk of MetS was lowest among those who slept 7-8 h at night. Gender-stratified analysis indicated that the J-shaped relationship between sleep durations at night and MetS remained significant in men but not in women., Conclusions: In older Chinese adults, sleep durations at night might have a dual effect on the risk of MetS and this effect was particularly pronounced in men. The results indicated that circadian rhythm might play an important role in the development of MetS in older populations.

Purpose: Observational studies have suggested a possible relationship between disordered sleep and myopia, but the association may be subject to selection biases. We aimed to minimize selection biases and assess the association by applying a propensity score matching (PSM) approach., Methods: The study was designed as a school-based cross-sectional study on a Chinese cohort aged 13-14 years in rural areas of China. The Chinese version of the Children's Sleep Habits Questionnaire was used for the measurement of sleep quality and a score of 41 or more was used to define the presence of disordered sleep. Each participant's refractive status was measured after cycloplegia using an autorefractor and myopia was defined as spherical equivalent <-0.50 D. The propensity scores for disordered sleep were formulated using nine potential confounders. We matched the propensity scores for subjects with and without disordered sleep within a caliper of 0.01 of logit function of propensity scores., Results: In this study, 474 pairs (1 subject with vs. 1 subject without disordered sleep) were successfully matched based on propensity scores. The odds ratio (OR) of myopia for disordered sleep before PSM reached conventional levels of statistical significance (OR: 1.43 95% confidence interval [CI] 1.05, 2.58, p = 0.01). After matching, the magnitude of association was reduced and the OR of myopia was not significant (OR: 1.54 95% CI 0.90, 2.57, p = 0.46)., Conclusions: At current stage, there are insufficient evidence indicating that disordered sleep could affect the development of myopia in adolescents.