Evaluation of thermal environment and human thermal comfort in 8 types of public places from 2019 to 2021 / 中华劳动卫生职业病杂志

Objective: To evaluate the thermal environment of different types of public places and the thermal comfort of employees, so as to provide scientific basis for the establishment of microclimate standards and health supervision requirements. Methods: From June 2019 to December 2021, 50 public places (178 times) of 8 categories in Wuxi were selected, including hotels, swimming pools (gymnasiums), bathing places, shopping malls (supermarkets), barber shops, beauty shops, waiting rooms (bus station) and gyms. In summer and winter, microclimate indicators such as temperature and wind speed were measured in all kinds of places, combined with the work attire and physical activity of employees in the places. Fanger thermal comfort equation and center for the built environment (CBE) thermal comfort calculation tool were used to evaluate the predicted mean vote (PMV), predicted percent dissatisfied (PPD) and standard effective temperature (SET) according to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 55-2020. The modification effects of seasonal and temperature control conditions on thermal comfort were analyzed. The consistency of GB 37488-2019 "Hygienic Indicators and Limits in Public Places" and ASHRAE 55-2020 evaluation results on thermal environment was compared. Results: The thermal sensation of hotel, barber shop staff and the gym front-desk staff were moderate, while the thermal sensation of swimming place lifeguard, bathing place cleaning staff and gym trainer were slightly warm in summer and winter. Waiting room (bus station) cleaning and working staff, shopping mall staff felt slightly warm in summer and moderate in winter. Service staff in bathing places felt slightly warm in winter, while staff in beauty salons felt slightly cool in winter. The thermal comfort compliance of hotel cleaning staff and shopping mall staff in summer was lower than that in winter (χ(2)=7.01, 7.22, P=0.008, 0.007). The thermal comfort compliance of shopping mall staff in the condition of air conditioning off was higher than that in the condition of air conditioning on (χ(2)=7.01, P=0.008). The SET values of front-desk staff in hotels with different health supervision levels were significantly different (F=3.30, P=0.024). The PPD value and SET value of the front-desk staff, and the PPD value of cleaning staff of hotels above three stars were lower than those of hotels below three stars (P<0.05). The thermal comfort compliance of front-desk staff and cleaning staff in hotels above three stars was higher than that in hotels below three stars (χ(2)=8.33, 8.09, P=0.016, 0.018). The consistency of the two criteria was highest among waiting room (bus station) staff (100.0%, 1/1) and lowest among gym front-desk staff (0%, 0/2) and waiting room (bus station) cleaning staff (0%, 0/1) . Conclusion: There are different degrees of thermal discomfort in different seasons, under the condition of air conditioning and health supervision, and the microclimate indicators can not fully reflect the thermal comfort of human body. The health supervision of microclimate should be strengthened, the applicability of health standard limit value should be evaluated in many aspects, and the thermal comfort of occupational group should be improved.

Reversible changes in aqueous outflow facility, hydrodynamics, and morphology following acute intraocular pressure variation in bovine eyes / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Elevated intraocular pressure (IOP) is primarily due to increased aqueous outflow resistance, but how aqueous outflow resistance is generated and regulated are still not fully understood. The aim of this study is to determine whether changes in outflow facility, outflow pattern, and morphology following acute IOP elevation were reversible when the IOP was returned to a normal level in bovine eyes using a two-color tracer technique to label outflow patterns within the same eye.</p><p><b>METHODS</b>Twelve fresh enucleated bovine eyes were perfused with Dulbecco's phosphate buffer saline (PBS) containing 5.5 mmol/L glucose (DBG) at 30 mmHg first to establish the baseline outflow facility followed by a fixed volume of red fluorescent microspheres (0.5 µm, 0.002% v/v). After the red tracer being replaced with DBG in the anterior chamber, perfusion was continued at 7 mmHg with the same volume of green tracer, followed by a fixative. In two control groups, the eyes were constantly perfused at either 30 mmHg (n = 6) or 7 mmHg (n = 6) using the same methods. The outflow facility (C, µl × min × (-1)mmHg(-1)), was continuously recorded. Confocal images were taken along the inner wall (IW) of the aqueous plexus (AP) in frontal sections. The percent of the effective filtration length (PEFL, PEFL = IW length exhibiting tracer labeling/total length of IW) was measured. Sections with AP were processed and examined by light microscopy. The total length of IW and the length exhibiting separation (SL) in the juxtacanalicular connective tissue (JCT) were measured. A minimum of eight collector channel (CC) ostia per eye were analyzed for herniations.</p><p><b>RESULTS</b>In the experimental (30 - 7 mmHg) group, the outflow facility was significantly higher at 7 mmHg ((4.81 - 1.33) µl × min × (-1)mmHg(-1)) than that at 30 mmHg ((0.99 ± 0.15) µl × min × (-1)mmHg(-1), P = 0.002), corresponding to a significant increase in the PEFL (P = 0.0003). The percent of CC ostia exhibiting herniations in the experimental group ((67.40 ± 8.90) µl × min × (-1)mmHg(-1)) decreased significantly compared to that in the control at 30 mmHg ((94.44 ± 3.33) µl × min × (-1)mmHg(-1), P = 0.03), but higher than that in the control at 7 mmHg ((29.43 ± 4.60) µl × min × (-1)mmHg(-1), P = 0.01). Washout-associated separation between the IW and JCT was found by light microscopy and percent separation length (PSL, PSL = SL/total length of IW) was decreased in the control at 30 mmHg compared to that in the experimental group and control at 7 mmHg.</p><p><b>CONCLUSIONS</b>The pressure-induced morphological and hydrodynamic changes were reversible. Changes (collapse of AP, separation between the JCT and IW, and herniation into CC ostia) influence the effective filtration area that regulates outflow facility.</p>