Quasi-linear viscoelastic properties of fibrotic neck tissues obtained from ultrasound indentation tests in vivo

Author name used in this publication: Sing-Fai Leung2004-2005 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Reliability of measurement of skin ultrasonic properties in vivo : a potential technique for assessing irradiated skin

Author name used in this publication: Y. P. HuangAuthor name used in this publication: Y. P. ZhengAuthor name used in this publication: A. F. T. MakAuthor name used in this publication: S. F. Leung2006-2007 > Academic research: refereed > Publication in refereed journalAuthor’s OriginalPublishe

High frequency ultrasound assessment of skin fibrosis : clinical results

Author name used in this publication: Y. P. HuangAuthor name used in this publication: Y. P. ZhengAuthor name used in this publication: S. F. LeungAuthor name used in this publication: A. P. C. Choi2007-2008 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Secondhand smoke exposure and maternal action to protect children from secondhand smoke: Pre- and post-smokefree legislation in Hong Kong

Background: Smokefree legislation may protect children from secondhand smoke (SHS) in the home from smoking parent(s). We examined the effect of the 2007 smokefree legislation on children's exposure to SHS in the home and maternal action to protect children from SHS exposure in Hong Kong. Methods: Families with a smoking father and a non-smoking mother were recruited from public clinics before (2005-2006, n = 333) and after the legislation (2007-2008, n = 742) which led to a major extension of smokefree places in Hong Kong. Main outcomes included children's SHS exposure in the home, nicotine level in mothers' and children's hair and home environment, mothers' action to protect children from SHS, and their support to the fathers to quit. Results: Fewer mothers post-legislation reported children's SHS exposure in the home (87.2% versus 29.3%, p<0.01), which was consistent with their hair nicotine levels (0.36ng/mg versus 0.04ng/mg, p<0.01). More mothers post-legislation in the last month took their children away from cigarette smoke (6.3% versus 92.2%; p<0.01) and advised fathers to quit over 3 times (8.3% versus 33.8%; p<0.01). No significant change was found in the content of smoking cessation advice and the proportion of mothers who took specific action to support the fathers to quit. Conclusions: SHS exposure in the home decreased and maternal action to protect children from SHS increased after the 2007 smokefree legislation. Maternal support to fathers to quit showed moderate improvement. Cessation services for smokers and specific interventions for smoking families should be expanded together with smokefree legislation. © 2014 Chan et al.published_or_final_versio

Effectiveness of smoking reduction intervention for hardcore smokers

© 2015 Lam et al.; licensee BioMed Central.Background: The prevalence and correlates of hardcore smokers, who have high daily cigarette consumption, no quitting history and no intention to quit, have been studied in several western developed countries, but no previous trials of smoking cessation have tested intervention effectiveness for these smokers. The current study examined if hardcore smokers can benefit from smoking reduction intervention to achieve cessation, and explored the underlying reasons. Methods: A posteriori analysis was conducted on data from a randomized controlled trial of smoking reduction intervention on 1,154 smokers who did not want to quit. Odds ratios of 7-day point prevalence of abstinence, smoking reduction by at least 50% and quit attempt at the 6-month follow-up comparing subgroups of smokers were analyzed. Results: In hardcore smokers, the odds ratio comparing the quit rate between the intervention and control group was 4.18 (95% CI: 0.51-34.65), which was greater than non-hardcore smokers (OR = 1.58, 95% CI: 0.98-2.54). The number needed to treat for hardcore and non-hardcore smokers was 8.33 (95% CI: 5.56-16.67) and 16.67 (95% CI: 8.33-233.64), respectively. In smokers who did not have quit attempt experience and those who smoked more than 15 cigarettes daily, the odds ratio comparing intervention and control group was 3.29 (95% CI: 0.72-14.98) and 1.36 (95% CI: 0.78-2.36), respectively. Conclusions: The a posteriori analysis provided pilot results that smoking reduction intervention may be effective to help hardcore smokers to quit and reduce smoking. Having no previous quit attempt was identified as more important than having large cigarette consumption in explaining the greater effectiveness of the intervention.published_or_final_versio

Self-catalytic ZnSe nanorods on grains synthesized using thermal evaporation method

In this paper, ZnSe nanorods grown on in-situ synthesized ZnSe grains are reported. The ZnSe products are synthesized through thermal evaporation of elementary materials of Zn and Se powders in a horizontal resistance furnace. It is interesting to note that the ZnSe nanorods of nearly the same diameter and length are obtained, and they grow in the same direction on a facet of the ZnSe grain. The ZnSe grains are random in shape, with well-defined bounded facets. The ZnSe grains can be synthesized in various growth conditions while the ZnSe nanorods can be synthesized on the ZnSe grains with the fulfillment of the Zn enriched condition. The growth of ZnSe nanorods can be described by the self-catalytic vapor-liquid-solid (VLS) mechanism.postprin

Synthesis of wurtzite ZnSe nanorings by thermal evaporation

In this study, free standing crystalline ZnSe nanorings and nanowires have been fabricated on Au coated Si substrates by simple thermal evaporation of ZnSe powders. Ring- or wirelike morphology can be achieved in a controllable manner by using different reactor pressures during growth, while all the other conditions remain the same. Our results show that the ZnSe nanorings are wurtzite phase instead of the zinc-blende phase, observed in typical one-dimensional ZnSe nanostructures. The growth mechanism of the nanorings has been discussed, and the cathodoluminescence of the nanorings has been described. © 2006 American Institute of Physics.published_or_final_versio

Synthesis and analysis of abnormal wurtzite ZnSe nanowheels

An abnormal structure of the ZnSe nanowheels composed of teethlike extended patterns on nanoring bases has been successfully synthesized by thermal evaporation method. It is interesting to note that the as-synthesized ZnSe nanowheels are metastable wurtzite phase with the dominant exposed surfaces of ± (2 1- 1- 0) while the stable ZnSe is typically zinc blende phase. A full picture of the growth mechanism of the metastable wurtzite phase ZnSe nanostructures will be proposed from the thermodynamic point of view. Meanwhile, the formation of the nanowheels is also explained by a two-stage mechanism. In the first stage, the base of the nanowheel begins to form by vapor-solid mechanism, while in the second stage, the teethlike extended structures grow through the self-catalyzed growth process. The cathodoluminescence spectrum of ZnSe nanowheel exhibited a band edge transition at about 460 nm and a strong self-activated luminescence at 610 nm. It is important to note that the discussions of the nanostructure thermodynamics and stability can be applied to understand the growth mechanism of other nanostructures which are critical for optimization of the nanostructures. © 2007 American Institute of Physics.published_or_final_versio

Rho GTPase-activating protein deleted in liver cancer suppresses cell proliferation and invasion in hepatocellular carcinoma

Deleted in liver cancer (DLC1) is a candidate tumor suppressor gene recently isolated from human hepatocellular carcinoma. Structurally, DLC1 protein contains a conserved GTPase-activating protein for Rho family protein (RhoGAP) domain, which has been thought to regulate the activity of Rho family proteins. Previous studies indicated that DLC1 was frequently inactivated in cancer cells. In the present study, we aimed to characterize the tumor suppressor roles of DLC1 in hepatocellular carcinoma. We showed that DLC1 significantly inhibited cell proliferation, anchorage-independent growth, and in vivo tumorigenicity when stably expressed in hepatocellular carcinoma cells. Moreover, DLC1 expression greatly reduced the motility and invasiveness of hepatocellular carcinoma cells. With RhoGAP-deficient DLC1 mutant (DLC1-K714E), we showed that the RhoGAP activity was essential for DLC1-mediated tumor suppressor function. Furthermore, the 292- to 648-amino acid region and the steroidogenic acute regulatory related lipid transfer domain played an auxiliary role to RhoGAP and tumor suppressor function of DLC1. Taken together, our findings showed that DLC1 functions as a tumor suppressor in hepatocellular carcinoma and provide the first evidence to support the hypothesis that DLC1 suppresses cancer cell growth by negatively regulating the activity of Rho proteins. ©2005 American Association for Cancer Research.postprin

Real-time ultrasonic assessment of progressive proteoglycan depletion in articular cartilage

2008-2009 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe