Associations of birth order with early adolescent growth, pubertal onset, blood pressure and size: Evidence from Hong Kong’s “Children of 1997” birth cohort

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Depolarization of a piezoelectric film under an alternating current field

2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Dynamic conductance of mesoscopic waveguides

We report a theoretical investigation of dynamic conductance G(), for general ac frequency , of two-dimensional mesoscopic waveguides whose transport is characterized by antiresonances. We calculate G() by numerically evaluating nonequilibrium Green's functions. By tuning the ac frequency we observe photon-assisted resonant transport as well as a gradual smearing out of the antiresonances. The antiresonance causes the dynamic response to vary between capacitive-like behavior to that of the inductive-like behavior. © 2001 American Institute of Physics.published_or_final_versio

Early life infections and pubertal onset: evidence from Hong Kong’s “children of 1997” birth cohort

Conference Theme: Changing populations, changing diseases: Epidemiology for Tomorrow’s WorldPoster session 2: Chronic disease: P2-148This journal suppl. contain programme and abstracts of the IEA World Congress of Epidemiology, 2011published_or_final_versionThe IEA World Congress of Epidemiology, Edinburgh, Scotland, 7–11 August 2011. In Journal of Epidemiology & Community Health, 2011, v. 65 suppl. 1, p. A261-A262, abstract no. P2-14

Is pre- or post-natal secondhand smoke exposure associated with childhood overweight? Hong Kong’s “Children of 1997” birth cohort

Poster presentation: abstract no. P-9C-422published_or_final_versio

Breast-feeding and childhood hospitalizations for infections

Background: Infectious disease is a leading cause of morbidity and hospitalization for infants and children. During infancy, breast-feeding protects against infectious diseases, particularly respiratory infections, gastrointestinal infections, and otitis media. Little is known about the longer-term impact of breast-feeding on infectious disease in children. Methods: We investigated the relationship between infant feeding and childhood hospitalizations from respiratory and gastrointestinal infections in a population-based birth cohort of 8327 children born in 1997 and followed for 8 years. The main outcomes were public hospital admissions for respiratory infections, gastrointestinal infections, and all infectious diseases. Cox regression was used to assess time to first hospitalization. Results: Breast-feeding only (no formula-feeding) for 3 or more months was associated with a lower risk of hospital admission in the first 6 months of life for respiratory infections (hazard ratio = 0.64 [95% confidence interval = 0.42-0.97]), gastrointestinal infections (0.51 [0.25-1.05]), and any infection (0.61 [0.44-0.85]), adjusted for sex, type of hospital at birth, and household income. Partial breast-feeding (both breast-feeding and formula-feeding) in the first 3 months also reduced hospitalizations from infections but with smaller effect sizes. Beyond 6 months of age, there was no association between breast-feeding status at 3 months and hospitalization for infectious disease. Conclusions: Giving breast milk and no formula for at least 3 months substantially reduced hospital admissions for many infectious diseases in the first 6 months of life, when children are most vulnerable. © 2010 by Lippincott Williams & Wilkins.postprin

The Role of Dairy Products and Milk in Adolescent Obesity: Evidence from Hong Kong's "Children of 1997" Birth Cohort

Background: Observational studies, mainly from Western populations, suggest dairy consumption is inversely associated with adiposity. However, in these populations the intake range is limited and both diet and obesity may share social patterning. Evidence from non-Western developed settings with different social patterning, is valuable in distinguishing whether observed associations are biologically mediated or socially confounded. Objective: To examine the associations of milk or other dairy product consumption with adolescent obesity. Methods: We used multivariable linear regression models to examine the associations of milk or other dairy product consumption, obtained from a food frequency questionnaire, at 11 years with body mass index (BMI) z-scores at 13 years and waist hip ratio (WHR) at 11 years, in 5,968 adolescents from a Chinese birth cohort, comprising 88% of births in April and May 1997. We used multiple imputation for missing exposures and confounders. Results: Only 65.7% regularly consumed milk and 72.4% other dairy products. Milk and other dairy product consumption was positively associated with socio-economic position but not with BMI z-score or WHR, with or without adjustment for sex, mother's birthplace, parental education, physical activity and other food consumption. Conclusions: The lack of association of milk and other dairy product consumption with adiposity in a non-Western setting was not consistent with the majority of evidence from Western settings. Observed anti-obesigenic effects in Western settings may be due to socially patterned confounding. © 2012 Lin et al.published_or_final_versio

Divergent secular trends in blood pressure and body mass index in children and adolescents in Hong Kong

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Practical computational toolkits for dendrimers and dendrons structure design

Dendrimers and dendrons offer an excellent platform for developing novel drug delivery systems and medicines. The rational design and further development of these repetitively branched systems are restricted by difficulties in scalable synthesis and structural determination, which can be overcome by judicious use of molecular modelling and molecular simulations. A major difficulty to utilise in silico studies to design dendrimers lies in the laborious generation of their structures. Current modelling tools utilise automated assembly of simpler dendrimers or the inefficient manual assembly of monomer precursors to generate more complicated dendrimer structures. Herein we describe two novel graphical user interface (GUI) toolkits written in Python that provide an improved degree of automation for rapid assembly of dendrimers and generation of their 2D and 3D structures. Our first toolkit uses the RDkit library, SMILES nomenclature of monomers and SMARTS reaction nomenclature to generate SMILES and mol files of dendrimers without 3D coordinates. These files are used for simple graphical representations and storing their structures in databases. The second toolkit assembles complex topology dendrimers from monomers to construct 3D dendrimer structures to be used as starting points for simulation using existing and widely available software and force fields. Both tools were validated for ease-of-use to prototype dendrimer structure and the second toolkit was especially relevant for dendrimers of high complexity and size.Peer reviewe