A new approach to HR monitoring using photoplethysmographic signals during intensive physical exercise.

The use of photoplethysmography (PPG) on the wrist to measure physiological indicators has attracted wide attention because of the portability and real-time characteristic of this technology. However, accurate estimation of the heart rate (HR) is difficult to realize using PPG because of the interference of motion artifacts. To address this problem, a method combining multichannel PPG signals is proposed. By using a peak selection method that combines several factors based on scores, the appropriate frequency is selected from the spectrum of the PPG signals. The chosen frequency is then considered as the HR. The approach exhibits high accuracy and speed. Experimental results for 12 training sets showed that with the proposed method, an average absolute error of 1.16 beats per minute (BPM) (standard deviation: 1.56 BPM) was obtained. Therefore, the proposed approach is reliable for HR monitoring from PPG during high-intensity physical activities. It can be applied to smart wearable devices for fitness tracking and health information tracking.

Formation of disinfection by-products during chlorination of organic matter from phoenix tree leaves and Chlorella vulgaris.

To better understand the precursor of disinfection by-products (DBPs) and provide useful information for water utilities to manage the drinking water, a study of DBP formation was conducted through chlorination of leaf organic matter (OM) from phoenix tree and algal OM from Chlorella vulgaris. DBPs investigated include trichloromethane (TCM), trichloroacetic acid (TCAA), dichloroacetic acid (DCAA), chloroacetic acid (CAA), dichloroacetonitrile (DCAN) and trichloroacetonitrile (TCNM). Results show that the specific yields (µg/mg C) of C-DBPs (TCM, CAA, DCAA and TCAA) from leaf OM were higher but the specific yields of N-DBPs (DCAN and TCNM) were lower than those from algal OM. Correlation analysis revealed that C-DBPs yields (µg/L) were significantly (p < 0.01) interrelated with each other (r = 0.937-0.996), and for each C-DBP, the hydrophobic OM contributed more to their formation (61-90% of total yields) as compared with hydrophilic OM. In spite of these characteristics, an in-depth examination was conducted revealing that the hydrophobicity and aromaticity of C-DBPs precursors were in the order of TCAA > DCAA & TCM > CAA. DCAN precursors were highly variable: they were dominated by hydrophobic OM (leaf OM: 86%) or hydrophilic OM (algal OM: 61%). Hydrophilic OM was the most important precursor for TCNM (76-79% of total yields), followed by hydrophobic neutral and base substances (29-45% of total yields), but the hydrophobic acids exhibited an inhibition role in TCNM formation.

Bromine incorporation into five DBP classes upon chlorination of water with extremely low SUVA values.

The main objective of this study was to assess the effects of disinfection conditions on bromine incorporation into disinfection by-products (DBPs) during chlorination of water with low specific UV absorbance (SUVA). Five classes of DBPs were included: trihalomethanes (THMs), dihaloacetic acids (di-HAAs), trihaloacetic acids (tri-HAAs), dihaloacetonitriles (DHANs) and trihalonitromethanes (THNMs). Results showed that the bromine utilization in DBPs formation was positive related with reaction time, pH and temperature. On the other hand, the bromine substitution factors (BSFs) of DBPs were generally increased with pH (except tri-HAAs) and bromide concentration, but decreased with the reaction time, temperature and chlorine dose. Moreover, the BSFs values varied with DBP classes with the ranking being as following: THNMs≫DHANs≫tri-HAAs>THM≈di-HAAs. These results were mostly similar with the references, yet the pH effect on BSFs as well as the rank of BSFs for different DBP classes may differ with the specific UV absorbance of organic matter.

MicroRNA-125a/b-5p inhibits endothelin-1 expression in vascular endothelial cells.

BACKGROUND: Endothelin-1 (ET-1) is considered to be one of the most potent and long-lasting vasoconstrictive peptides, but the mechanisms on the regulation of ET-1 expression are not fully understood. METHOD AND RESULTS: In this study, we found that microRNA (miR)-125a-5p and miR-125b-5p are highly expressed in vascular endothelial cells (VECs), which can be regulated by oxidized low-density lipoprotein (oxLDL). To explore the function of miR-125a/b-5p in VECs, we examined the roles of potential targets of miR-125a/b-5p that could influence endothelium function. We found that both miR-125a/b-5p can suppress oxLDL-induced ET-1 expression by directly targeting 3' untranslated region of prepro-endothelin-1 (preproET-1) mRNA determined by luciferase reporter assay, western blot, and enzyme immunometric assay. Consistently, inhibitors of miR-125a/b-5p can directly enhance preproET-1 expression. The decreased expressions of miR-125a-5p and miR-125b-5p are negatively associated with upregulation of preproET-1 expression in aorta of stroke-prone spontaneously hypertensive rats (SHR-SPs). CONCLUSION: Our finding demonstrated that endothelial miR-125a/b-5p inhibits ET-1 expression in VECs, which revealed a novel miRNA-mediated mechanism in vasomotor homeostasis.