Metamaterial beam with bistable and monostable-hardening attachments for broad-band vibration attenuation and energy harvesting

Dynamic local resonating (LR) metastructures possess the ability to suppress the propagation of vibrations within a specific frequency range known as a bandgap. However, metastructures with pure linear local resonators have limited bandgap size and inevitably form new resonating peaks close to the bandgap. This paper proposes a metastructure that features alternatively arranged oscillators with bistable and monostable cubic hardening nonlinearities, as well as electromechanical coupling. This design effectively suppresses high-amplitude resonating transmission peaks near the bandgap and maintains the bandgap at high excitation levels. In addition, it can create a broad bandwidth with high power output, which can be applied as a practical source of electrical energy, thereby forming a well-balanced and performance-enhanced dual-functional metastructure for vibration suppression and energy harvesting. The proposed metastructure is established and calculated using a distributed-parameter model. The influence of nonlinearity stiffness and electrical-mechanical coupling index are investigated. Results show that enhanced performance of both vibration attenuation and energy harvesting can be realized with the proposed metastructure at a large range of excitation level. The parametric results offer a valuable reference for the development of dual-functional metastructures for simultaneous vibration suppression and energy harvesting

Hepatic Carboxylesterase 1 Is Induced by Glucose and Regulates Postprandial Glucose Levels

Metabolic syndrome, characterized by obesity, hyperglycemia, dyslipidemia and hypertension, increases the risks for cardiovascular disease, diabetes and stroke. Carboxylesterase 1 (CES1) is an enzyme that hydrolyzes triglycerides and cholesterol esters, and is important for lipid metabolism. Our previous data show that over-expression of mouse hepatic CES1 lowers plasma glucose levels and improves insulin sensitivity in diabetic ob/ob mice. In the present study, we determined the physiological role of hepatic CES1 in glucose homeostasis. Hepatic CES1 expression was reduced by fasting but increased in diabetic mice. Treatment of mice with glucose induced hepatic CES1 expression. Consistent with the in vivo study, glucose stimulated CES1 promoter activity and increased acetylation of histone 3 and histone 4 in the CES1 chromatin. Knockdown of ATP-citrate lyase (ACL), an enzyme that regulates histone acetylation, abolished glucose-mediated histone acetylation in the CES1 chromatin and glucose-induced hepatic CES1 expression. Finally, knockdown of hepatic CES1 significantly increased postprandial blood glucose levels. In conclusion, the present study uncovers a novel glucose-CES1-glucose pathway which may play an important role in regulating postprandial blood glucose levels

Association between monocyte lymphocyte ratio and abdominal aortic calcification in US adults: A cross-sectional study

Background This study aimed to evaluate the association between Monocyte Lymphocyte Ratio (MLR) and Abdominal Aortic Calcification (AAC) in adults over 40 years of age in the United States. Methods Data were collected from the 2013–2014 National Health and Nutrition Examination Survey (NHANES). AAC was quantified by the Kauppila score system based on dual-energy X-Ray absorptiometry. Severe AAC was defined as a total AAC score > 6. The lymphocyte count and monocyte count can be directly obtained from laboratory data files. Multivariable logistic regression models were used to determine the association between MLR and the AAC score and severe AAC. Results A total of 3,045 participants were included in the present study. After adjusting for multiple covariates, MLR was positively associated with higher AAC score (β = 0.21, 95% CI 0.07, 0.34, p = 0.0032) and the odds of severe AAC increased by 14% per 0.1 unit increase in the MLR (OR = 1.14, 95% CI 1.00, 1.31, p = 0.0541). The Odds Ratio (OR) (95% CI) of severe AAC for participants in MLR tertile 3 was 1.88 (1.02, 3.47) compared with those in tertile 1 (p for trend = 0.0341). Subgroup analyses showed that a stronger association was detected in the elderly compared with non-elderly (p for interaction = 0.0346) and diabetes compared with non-diabetes (borderline significant p for interaction = 0.0578). Conclusion In adults in the United States, MLR was associated with higher AAC scores and a higher probability of severe AAC. MLR may become a promising tool to predict the risk of AAC