Effect of Local Floor Heating System on Occupants’ Thermal Comfort and Energy Consumption Using Computational Fluid Dynamics (CFD)

In this article, the influence of splitting a local underfloor air distribution system (UFAD) on indoor thermal comfort for three occupants was studied numerically. A validated computational fluid dynamics (CFD) model was employed in this investigation. The proposed heating system was evaluated and analyzed for different values of air temperature and supply velocity. Providing suitable thermal comfort and saving energy are considered the main evaluation indexes for this study. Three cases, cases 2, 3, and 4, of the proposed local UFAD system were compared with a traditional heating system case, case 1. The supplying air velocity and air temperature in the reference case were 0.5 m/s and 29 °C, while in cases 2, 3, and 4, they were 0.4 m/s and 29 °C, 28 °C, and 27 °C, respectively. The results show that acceptable indoor human thermal comfort and energy demand reduction were achieved by using the splitting UFAD concept

Pulmonary-arterial-hypertension (PAH)-on-a-chip: fabrication, validation and application

Currently used animal and cellular models for pulmonary arterial hypertension (PAH) only partially recapitulate its pathophysiology in humans and are thus inadequate in reproducing the hallmarks of the disease, inconsistent in portraying the sex-disparity, and unyielding to combinatorial study designs. Here we sought to deploy the ingenuity of microengineering in developing and validating a tissue chip model for human PAH. We designed and fabricated a microfluidic device to emulate the luminal, intimal, medial, adventitial, and perivascular layers of a pulmonary artery. By growing three types of pulmonary arterial cells (PACs)-endothelial, smooth muscle, and adventitial cells, we recreated the PAH pathophysiology on the device. Diseased (PAH) PACs, when grown on the chips, moved of out their designated layers and created phenomena similar to the major pathologies of human PAH: intimal thickening, muscularization, and arterial remodeling and show an endothelial to mesenchymal transition. Flow-induced stress caused control cells, grown on the chips, to undergo morphological changes and elicit arterial remodeling. Our data also suggest that the newly developed chips can be used to elucidate the sex disparity in PAH and to study the therapeutic efficacy of existing and investigational anti-PAH drugs. We believe this miniaturized device can be deployed for testing various prevailing and new hypotheses regarding the pathobiology and drug therapy in human PAH

Association between pet ownership and cardiovascular risks and mortality: a systematic review and meta-analysis

The aim of the study was to determine the association between pet ownership and cardiovascular risk factors and mortality. Electronic search was conducted through nine databases including PubMed for relevant publications reporting cardiovascular events and mortality among pet owners. Meta-analysis was used to pool the results. Of a total of 2818 reports screened, 26 studies were included in our systematic review and meta-analysis. Higher survival rate was observed in the pet owners group after pooling nonadjusted and adjusted hazard ratios for cardiovascular mortality at 0.73 [95% confidence interval (CI) 0.62–0.86] and 0.81 (0.68–0.97), respectively. A similar trend was observed for the pooled nonadjusted hazard ratio for overall mortality 0.73 (0.62–0.87) but not the adjusted hazard ratio 0.40 (0.04–3.78). Cat owners have a reduction in cardiovascular mortality but not overall mortality after pooling the adjusted hazard ratio 0.79 (0.63–0.99) and 1.04 (0.90–1.21), respectively. However, no significant association between dog owners and survival rate was observed for overall and cardiovascular-specific mortality. Pet owners had significantly lower heart rate (mean difference 95% CI: −2.32 (−3.07 to −1.57), mean arterial pressure −2.60 (−4.25 to −0.95) and SBP −1.69 (−3.06 to −0.31) but not DBP −0.23 (−1.05 to 0.60). No significant difference was observed between pet owners and nonpet owners in prevalence of hypertension. Our study draws attention to the beneficial effects of the human--pet bond; therefore, we recommend pet acquisition for better cardiovascular outcomes after controlling for zoonotics and pet-induced allergies