14,306 research outputs found
Some new nonlinear retarded sum-difference inequalities with applications
The main objective of this paper is to establish some new retarded nonlinear sum-difference inequalities with two independent variables, which provide explicit bounds on unknown functions. These inequalities given here can be used as handy tools in the study of boundary value problems in partial difference equations. © 2011 Wang et al; licensee Springer.published_or_final_versio
Finite-temperature Gutzwiller projection for strongly correlated electron systems
We generalized the Gutzwiller projectional variational method for the ground state of strongly correlated electron systems to the case of finite temperature. Under the Gutzwiller approximation, we show that this maps to a finite temperature renormalized mean-field theory. As one of the key ingredients in the theory, we obtained an explicit expression of the projection entropy or the entropy change due to the projection. We illustrate the application of the theory to the Anderson impurity problem and the half-filled Hubbard model and compare the theory to more elaborate techniques. We find qualitative agreement. The theory can be applied to a wide variety of Hubbard, t-J, and Anderson impurity models. © 2010 The American Physical Society.published_or_final_versio
Overestimation of peer smoking prevalence predicts smoking initiation among primary school students in Hong Kong
Purpose: To investigate the relationship between perceived prevalence of smoking and smoking initiation among Hong Kong primary second- to fourth-grade-students. Methods: A cohort of 2,171 students was surveyed in 2006 and again in 2008. Students who perceived ever-smoking prevalence in peers as "none" or "some" were considered as correct (reference group), whereas those who perceived it as "half" (overestimation) or "most/all" (gross overestimation) were considered as incorrect. Results: At baseline, overestimation was found to be cross-sectionally associated with ever-smoking (p < .01). At follow-up, 7.2% of never-smoking students with incorrect estimation at baseline had started smoking, which was 79% (95% confidence interval: 3%-213%), greater than that of 3.7% for those with correct estimation. Among the never-smoking students with incorrect estimation, subsequent correct estimation was associated with 70% (95% confidence interval: 47%-83%) lower risk of smoking initiation compared with persistent incorrect estimation. Conclusion: Overestimation of the prevalence of peer smoking predicted smoking initiation among children. Interventions should be carried out to evaluate whether correcting children's overestimation of peer smoking could reduce smoking initiation. © 2011 Society for Adolescent Health and Medicine.postprin
The impact of green buildings accreditation on construction and demolition waste minimization: A study of Hong Kong Building Environment Assessment Method using big data.
Workshop 8: WS8.12Construction and demolition (C&D) waste often constitutes a prodigious portion of the total municipal solid waste in contributing to the environment degradation. C&D waste minimization, which is a sustainable activity for both environment and material resources, serves as an indispensible element of green building assessment systems worldwide. How green building accreditation impacts on C&D waste minimization is a valid and important research question for green building award applicants, policy-makers and other stakeholders, which was seldom studied using a quantitative approach. Therefore, this paper aims to quantify the waste minimization which existing green building assessment system can be used to achieve by analyzing a big dataset of C&D waste management recorded in 2011, 2012, 2013, 2014 and 2015 in Hong Kong. The waste generation rates are compared between buildings awarded with and without Hong Kong Building Environment Assessment Method (HK-BEAM) prizes to illustrate the impact of HK-BEAM on C&D waste minimization. The research findings will not only present accurately quantified effect on CWM led by green building accreditation, but also provide stakeholders with a reference for making strategies and policies on C&D waste management and green building.preprin
The association of cytoplasmic overexpression of cyclin d1 and tumor metastasis in Hepatocellular Carcinoma
published_or_final_versio
Independent association between parental smoking and non-authoritative parenting style as reported by Chinese adolescents in Hong Kong
Poster Discussion 35. Engaging New Partners: no. PD-1005-20Conference Theme: Tobacco and Non-Communicable DiseasesBACKGROUND: Both parental smoking and non-authoritative parenting style predict adolescent smoking, but the association between the two risk factors was seldom studied. We investigated this association in Chinese parents of adolescents in Hong Kong, where smoking is socially undesirable, especially in females. DESIGN/METHODS: In the Hong Kong Student Obesity Surveillance project 2006/07, 33692 adolescents aged 11-18 (44.9% boys, mean age 14.8, SD 1.9 years) from 42 randomly selected schools reported smoking status (yes vs no) and the level (frequent/sometimes as high; seldom/none as low) of care and control of each parent. Parenting style (dependent variable) was defined as authoritative …published_or_final_versio
Alternative antibody for the detection of CA19-9 antigen: a European multicenter study for the evaluation of the analytical and clinical performance of the Access (R) GI Monitor assay on the UniCel (R) Dxl 800 Immunoassay System
Background: Gastrointestinal cancer antigen CA19-9 is known as a valuable marker for the management of patients with pancreatic cancer. Methods: The analytical and clinical performance of the Access(R) GI Monitor assay (Beckman Coulter) was evaluated on the UniCel(R) Dxl 800 Immunoassay System at five different European sites and compared with a reference method, defined as CA19-9 on the Elecsys System (Roche Diagnostics). Results: Total imprecision (%CV) of the GI Monitor ranged between 3.4% and 7.7%, and inter-laboratory reproducibility between 3.6% and 4.0%. Linearity upon dilution showed a mean recovery of 97.4% (SD+7.2%). Endogenous interferents had no influence on GI Monitor levels (mean recoveries: hemoglobin 103%, bilirubin 106%, triglycerides 106%). There was no high-dose hook effect up to 115,000 kU/L. Clinical performance investigated in sera from 1811 individuals showed a good correlation between the Access' GI Monitor and Elecsys CA19-9 (R = 0.959, slope = 1.004, intercept +0.17). GI Monitor serum levels were low in healthy individuals (n = 267, median = 6.0 kU/L, 95th percentile = 23.1 kU/L), higher in individuals with various benign diseases (n = 550, medians = 5.8-13.4 kU/L, 95th percentiles = 30.1-195.5 kU/L) and even higher in individuals suffering from various cancers (n = 995, medians = 8.4-233.8 kU/L, 95th percentiles = 53.7-13,902 kU/L). Optimal diagnostic accuracy for cancer detection against the relevant benign control group by the GI Monitor was found for pancreatic cancer {[}area under the curve (AUC) 0.83]. Results for the reference CA19-9 assay were comparable (AUC 0.85). Conclusions: The Access(R) GI Monitor provides very good methodological characteristics and demonstrates an excellent analytical and clinical correlation with the Elecsys CA19-9. The GI Monitor shows the best diagnostic accuracy in pancreatic cancer. Our results also suggest a clinical value of the GI Monitor in other cancers
Secondhand Smoke Exposure and Health Services Use among Adolescent Current Smokers
Background:To investigate the associations of secondhand smoke (SHS) exposure with medical consultation and hospitalisation among adolescents in Hong Kong.Methods:A total of 35827 secondary 1 (US grade 7) to secondary 5 students from 85 randomly selected schools completed an anonymous questionnaire on smoking, SHS at home, SHS outside home, medical consultation in the past 14 days, hospitalisation in the past 12 months, and socio-demographic characteristics. Current smoking was defined as any smoking in the past 30 days. SHS exposure was classified as none (reference), 1-4 and 5-7 days/week. Logistic regression yielded adjusted odds ratios (AORs) for medical consultation and hospitalisation in relation to SHS exposure at home and outside home in current smokers. Analyses were also done among never-smokers for comparison.Results:Among all students, 15.9% had medical consultation and 5.2% had been hospitalised. Any SHS exposure at home was associated with AORs (95% CI) for medical consultation and hospitalisation of 1.69 (1.14-2.51) and 2.85 (1.47-5.52) in current smokers, and 1.03 (0.91-1.15) and 1.25 (1.02-1.54) in never-smokers, respectively, (P<0.01 for interaction between smoking status and SHS exposure at home). SHS exposure outside home was generally not associated with medical consultation and hospitalisation in smokers and never-smokers.Conclusions:SHS exposure at home was associated with health services use among adolescent current smokers. Adolescent smokers should be aware of the harm of SHS in addition to that from their own smoking. The evidence helps health care professionals to advise adolescent smokers to avoid SHS exposure and stop smoking. © 2013 Wang et al.published_or_final_versio
Impact of glycaemic control on circulating endothelial progenitor cells and arterial stiffness in patients with type 2 diabetes mellitus
Topics: Basic science, translational and clinical researchPoster PresentationThis journal supplement contains abstracts from the 17th MRC; Dept. of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong KongINTRODUCTION: Patients with type 2 diabetes mellitus (DM) have increased risk of endothelial dysfunction and arterial stiffness. Levels of circulating endothelial progenitor cells (EPCs) are also reduced in hyperglycaemic states. However, the relationships between glycaemic control, levels of EPCs and arterial stiffness are unknown. METHODS: We measured circulating EPCs and …published_or_final_versionThe 17th Medical Research Conference (MRC), Department of Medicine, University of Hong Kong, Hong Kong, 14 January 2012. In Hong Kong Medical Journal, 2012, v. 18 suppl. 1, p. 63, abstract no. 10
Exposure to secondhand smoke from neighbours and respiratory symptoms in never-smoking adolescents in Hong Kong: a cross-sectional study
published_or_final_versio
- …
