Melatonin concentrations in serum of primary glaucoma patients

AIM： To determine whether glaucoma patients exhibit an abnormal melatonin concentration in serum and the effects of psychiatric disorders caused by glaucoma in melatonin secretion.METHODS： A sample of 80 primary angle-closure glaucoma（PACG） patients, 120 primary open angle glaucoma（POAG） patients, and 120 normal controls were enrolled in this study. All the participants were asked to complete the following questionnaires： Pittsburgh sleep quality index（PSQI）, self-rating anxiety scale（SAS）, and self-rating depression scale（SDS）. Variance analysis was used to compare the subscores between the groups. After that, we chose 58 patients with primary glaucoma and 20 nonglaucoma control patients to collect their serum samples at 7-10 a.m. Serum melatonin levels were measured using enzyme linked immunosorbent assay（ELISA）. RESULTS： Of all participants, the scores of PSQI, SAS, and SDS in PACG and POAG group were 9.38±0.40, 46.08±8.99, 51.11±10.72 and 7.43±0.35, 45.42±9.87, 49.04±12.24 respectively, significantly higher than those in control group（4.16±0.28, 35.49±9.18, 40.31±13.08）. The serum melatonin levels in PACG（37.29±2.99 pg/mL） and POAG（35.97±3.64 pg/mL） were significantly higher than the controls（29.96±3.94 pg/m L）（P〈0.001）. But no difference was found between the PACG and POAG（P=0.216）. Glaucoma patients with sleep disorders, anxiety and depression were more likely resulting in the increase of melatonin levels.CONCLUSION： There is a significant increase in serum melatonin levels in glaucoma patients compared to the controls especially in glaucoma patients with psychiatric disorders such as sleep disorders, anxiety and depression.

Ferroelectric composite-based piezoelectric energy harvester for selfpowered detection of obstructive sleep

Lead-free piezoelectric ceramic is a promising material for energy harvesters,as they have superior electromechanical,ferroelectric,and piezoelectric properties.In addition,piezoelectric ceramics can be blended with polymer to achieve high-flexibility polymer-ceramic composites,providing mechanical robustness and stability.In this context,a new lead-free ferroelectric material,having the chemical formula SrTi_(2)O_(5)(STO),was synthesized using a high-temperature solid-state reaction.Detailed analyses of the structural,morphological,and electrical properties of the synthesized material were performed.STO crystallizes with orthorhombic symmetry and space group of Cmm2.The frequency and temperature-dependent dielectric parameters were evaluated,and impedance spectroscopy shed light on the charge dynamics.The PDMS-STO composites at different mass fraction of the STO were prepared using a solvent casting route,and a corresponding piezoelectric nanogenerator(PENG)was developed.The electrical output of the different PENG by varying massfractions of STO in PDMS and varying force were investigated.The 15%(in mass)PENG device delivered the highest peak-to-peak voltage,current,and power density of 25 V,92 nA,and 0.64 mW@500 MU,respectively.The biomechanical energy harvesting using the PENG device by daily human motions,bending of the device,and attaching the device to laboratory equipment was demonstrated.Later the PENG device was attached to the human throat region,and snoring signals were recorded.A classification model was designed employing the convolutional neural network(CNN)model.Efforts have been laid to differentiate between normal and abnormal snores,which could help the patient with screening and early disease detection,contributing to self-powered healthcare applications.