Thermal comfort and energy performance of chilled ceiling systems

Chilled ceiling systems are a relatively new approach to cooling and they have been applied in Europe and other countries for many years. The technology is based on ceiling-based radiant cooling panels coupled with chilled water pipes or coils. By combing convection and radiation, these systems have the potential to enhance thermal comfort and reduce energy use in air-conditioned buildings. This research studied the basic principles and key characteristics of chilled ceiling systems in order to assess their potential benefits on thermal comfort and energy performance. Field studies in two pilot projects in Hong Kong were carried out to investigate the system performance and practical considerations. Building energy simulation was applied to assess the potential benefits of the system on building energy performance. It is found from the field studies that the thermal comfort can be maintained in most of the time but some occupants feel that the air movement is sometimes too low. As compared with the conventional all-air systems, the chilled ceiling systems can reduce energy requirements by increasing chilled water temperature, decreasing supply air flow, downsizing air handling equipment and promoting higher room temperature. The results of building energy simulation show that the fan energy saving is the most important component and the percentages of energy saving for the HVAC system (19.8%) and the whole building (12.1%) are significant. 冷却吊顶系统是一个相对较新的冷却方法，在欧洲和其他国家已应用多年。该技术是基于冷冻水管道或盘管联结的天花板辐射冷却面板。这些系统通过结合对流和辐射，有潜力以提高热舒适度，并减少空调建筑物的能源使用。本研究探讨冷却吊顶系统的基本原理和主要特点，以评估其对热舒适性和节能性能潜在的好处。在香港的两个试点项目，进行了系统性能的调查和实际的考虑。并且应用建筑能耗模拟，来评估系统性能的潜在建筑节能好处。从研究试点项目发现，系统可以在大部分时间保持热舒适性，但也一些用户感到空气的流动有时过低。冷却吊顶系统与传统的全空气系统相比，可降低冷冻水温度增加的能源需求，减少空调供应送风量，削减空气处理设备，并促进更高的室温。建筑节能模拟分析结果表明，风机节能是最重要的组成部分，对空调系统(19.8%)和整个建筑(12.1%)的节能百分比结果是显著的。postprin

Influenza A(H5N1) Virus Infection in a Child With Encephalitis Complicated by Obstructive Hydrocephalus

A 2-year-old boy with highly pathogenic avian influenza A(H5N1) virus infection with minimal respiratory symptoms developed encephalitis complicated by obstructive hydrocephalus. Viral RNA was detectable in cerebrospinal fluid. The virus belonged to H5N1 clade 2.3.2.1b and had acquired the mammalian adaptation mutation PB2 Q591K.published_or_final_versio

Obstetric professionals’ perceptions of non-invasive prenatal testing for Down syndrome: clinical usefulness compared with existing tests and ethical implications

Background: While non-invasive prenatal testing (NIPT) for fetal aneuploidy is commercially available in many countries, little is known about how obstetric professionals in non-Western populations perceive the clinical usefulness of NIPT in comparison with existing first-trimester combined screening (FTS) for Down syndrome (DS) or invasive prenatal diagnosis (IPD), or perceptions of their ethical concerns arising from the use of NIPT. Methods: A cross-sectional survey among 327 obstetric professionals (237 midwives, 90 obstetricians) in Hong Kong. Results: Compared to FTS, NIPT was believed to: provide more psychological benefits and enable earlier consideration of termination of pregnancy. Compared to IPD, NIPT was believed to: provide less psychological stress for high-risk women and more psychological assurance for low-risk women, and offer an advantage to detect chromosomal abnormalities earlier. Significant differences in perceived clinical usefulness were found by profession and healthcare sector: (1) obstetricians reported more certain views towards the usefulness of NIPT than midwives and (2) professionals in the public sector perceived less usefulness of NIPT than the private sector. Beliefs about earlier detection of DS using NIPT were associated with ethical concerns about increasing abortion. Participants believing that NIPT provided psychological assurance among low-risk women were less likely to be concerned about ethical issues relating to informed decision-making and pre-test consultation for NIPT. Conclusions: Our findings suggest the need for political debate initially on how to ensure pregnant women accessing public services are informed about commercially available more advanced technology, but also on the potential implementation of NIPT within public services to improve access and equity to DS screening services

Enhancing disaster preparedness among pre-clinical year medical students with a 1-day concentrated curriculum with a blended learning approach: a mixed method feasibility study

Organizer: Hong Kong College of Emergency Medicine (HKCEM

Sexual function, self-esteem, and general well-being in Chinese adult survivors of childhood cancers : a cross-sectional survey

202002 bcrcVersion of RecordPublishe

Risk factors for community-associated methicillin-resistant Staphylococcus aureus infection in Hong Kong

OBJECTIVES: The risk factors for community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infection were not well understood. The objective of this study was to identify risk factors associated with CA-MRSA infection in Hong Kong. METHODS: We carried out a matched case control study. Cases and controls were recruited from 14 acute public hospitals in Hong Kong. One control was individually matched to one case based on sex, age, admission date and ward location. We interviewed each case and control by telephone using a standard questionnaire. We used a conditional logistic regression model for multivariate analysis. RESULTS: We successfully recruited 127 pairs of matched case and control. We found that sharing of personal items with other persons had a higher risk of CA-MRSA infection (Adjusted matched odds ratio [aOR]: 4.71, 95% confidence interval [CI] 1.43-15.59). On the other hand, patients who had frequent hand washing practice (aOR: 0.21, 95%CI 0.06-0.72) and those who reported history of acne (aOR: 0.12, 95%CI 0.02-0.74) had a lower risk of CA-MRSA infection. CONCLUSIONS: We concluded that sharing of personal items with other persons is a risk factor for CA-MRSA infection while frequent hand washing is a protective factor against the infection.link_to_subscribed_fulltex

Reversal of multidrug resistance in cancer cells by pyranocoumarins isolated from Radix Peucedani

The pyranocoumarins, (±)-3′-angeloyl-4′-acetoxy-cis-khellactone, were isolated from Radix Peucedani, the dry root of Peucedanum praeruptorum Dunn, through bioassay-guided fractionation. The chemical structure of pyranocoumarins was determined by mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy. X-ray crystallography showed that there are eight molecules (i.e. two each of four conformers) in each unit cell with their optical activities equally cancelled out. The four conformers are 3′(R)-angeloyl-4′(R)-acetoxy-khellactone in two conformational forms, and 3′(S)-angeloyl-4′(S)-acetoxy-khellactone in two conformational forms. Pyranocoumarins caused apoptotic cell death with IC50 of 41.9±2.8 and 17.3±8.2 μM for drug-sensitive KB-3-1 and multidrug resistant (MDR) KB-V1, respectively. The two- to threefold sensitivity difference between the two cell lines is interesting considering that the same ratio for doxorubicin is 50-300. Strong synergistic interactions were demonstrated when pyranocoumarins were combined with common anti-tumor drugs including doxorubicin, paclitaxel, puromycin or vincristine in MDR KB-V1 cell line, but not in drug-sensitive KB-3-1 cells. Pyranocoumarins increased doxorubicin accumulation in KB-V1 cells by about 25% after 6 h of incubation. Pyranocoumarins treatment for 24 h down-regulated the expression of P-glycoprotein in KB-V1 cells at both protein and mRNA levels. Pyranocoumarins also transiently reduced the cellular ATP contents in KB-V1 cells in a dose-dependent manner. Our results suggest that pyranocoumarins could be a potential MDR reversing agent. © 2003 Elsevier B.V. All rights reserved.link_to_subscribed_fulltex

Age-friendliness and life satisfaction of young-old and old-old in Hong Kong

2016-2017 > Academic research: refereed > Publication in refereed journalbcrcVersion of RecordPublishe