Effect of sintering holding time on the properties and low-temperature degradation behaviour of manganese oxide-doped Y-TZP ceramic

S.M. Kwa,S. Ramesh,L.T. Bang,Y.H. Wong,W.J. Kelvin Chew,C.Y. Tan,J. Purbolaksono,H. Misran,W.D. Teng 한양대학교 세라믹연구소 2015 Journal of Ceramic Processing Research Vol.16 No.2

The sintering of yttria-tetragonal zirconia polycrystals (Y-TZP) is commonly carried at a predefined temperature using a long holding time of 2 hours. This often has resulted in grain coarsening which affects the mechanical properties of the sintered body and low temperature degradation (LTD) behaviour of the ceramic when exposed to moist environment. In this research, the effect of using a short holding time of 1 min. during sintering coupled with small amounts (0.5 and 1 wt%) of manganese oxide, MnO2 as dopant on the mechanical properties and LTD behaviour of 3 mol% Y-TZP were investigated. The results showed that the mechanical properties improved significantly with the addition of 0.5 wt% MnO2 for the 1-min. and 12-min. holding time samples when compared to 2 hours holding time sintered at the same temperature of 1350 ℃. Nevertheless, regardless of the holding time employed, the 1 wt% MnO2 addition was not effective in improving the mechanical properties and ageing resistance of Y-TZP ceramic.

Is Adjuvant Transarterial Chemoembolization Useful for Hepatocellular Carcinoma?

( Wong Hoi She ),( Cheung Tan To ),( Simon H. Y. Tsang ),( Wing Chiu Dai ),( Albert C. Y. Chan ),( Kenneth S. H. Chok ),( Kelvin K. C. Ng ),( Chung Mau Lo ) 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: Hepatectomy is the well-established curative treatment for hepatocellular carcinoma (HCC). However, adjuvant therapy is still controversial. This study tried to look into the effect of transarterial chemoembolization (TACE) in patients receiving hepatectomy for HCC. Methods: This is a retrospective study held in a single institution using prospectively maintained database for all the patients who underwent hepatectomy for HCC between January 2000 - December 2015. The perioperative details, pathological data and outcome were studied. Patients were matched at 1:10 ratio with comparable tumor size, number, indocyanine green retention test at 15 minutes, Child’s grading and tumor staging. The Kaplan-Meier method was used for survival analysis. The log-rank test was used for survival comparison. Results: There were total 1316 patients underwent hepatectomy for HCC. 38 patients with TACE were identified, and matched with 380 patients without TACE. The patients’ characteristics including age, sex, comorbidity, Child’s grading, ICG, tumor size and numbers were the same. The median sizes of the tumor were similar (9cm in TACE vs 8cm). There was no difference in terms of intraoperative management, extent of hepatectomy and postoperative complications. There were more patients with margin involvement in TACE group (23.7% vs 7.9%, p=0.004). The staging of the disease showed no significant difference in both groups. The disease free survival was similar (12.6 (TACE) vs 10.1months, p=0.794). There was no difference in overall survival with median survival of 27.8 (TACE) vs 36.9 months (5-year overall survival of 27.9% vs 41.2%, p=0.941). Conclusions: Margin involvement was known to be adverse factor for survival. Adjuvant TACE may benefit high-risk HCC patients with margin involvement as shown to have similar survival for those patients without margin involvement.

Assessment Of Robot Training for Social Cognitive Learning

H. Y. A. Wong,Z. W. Zhong 제어로봇시스템학회 2016 제어로봇시스템학회 국제학술대회 논문집 Vol.2016 No.10

The number of children diagnosed with autism spectrum disorders (ASD) is on the rise internationally. Most of these children require some degree of special education provision, whether they are educated in regular or specialized settings. Most if not all children with ASD exhibit some impairments with social communication skills. Yet, these skills are associated with outcomes in cognitive functioning and communication. One area employed is social robots to impart social skills in children with ASD. One reason for using social robots is that children with ASD tend to exhibit social behaviors such as eye contact when interacting with robots. This study seeks to examine the extent to which a small and portable robotic platform may be developed to impart social communication skills among children with ASD in specialized educational settings. This study seeks to adapt the social robot for learning social communication skills among children with ASD. In particular, the degree to which these goals can be taught, the speed of skill acquisition, and the degree of intervention will be measured. This research had contributed in three areas. Firstly, this study expounded the idea of “Model of Communication” that could be utilized for constructing social robots that correspond with people and teach social skills. Secondly we found significant improvements in turn-taking skills and more importantly, joint attention. Thirdly, we identified longer duration in eye contact engagement.

ELECTRON TRAPPING AND DETRAPPING BEHAVIORS OF THIN THERMALLY NITRIDED OXIDES

ChEng, Y. C.,Wong, H.,Lo, H. B.,Lai, P. T.,Liu, Z. H. 대한전자공학회 1989 ICVC : International Conference on VLSI and CAD Vol.1 No.1

This work reports the electron trapping and de trapping behaviors of thin ($lt;300Å) thermally grown oxide annealed in pure ammonia at high temperature ($gt;1000℃). The phenomena are investigated by using the low-frequency noise measurement on MOSFETs, monitoring the flatband-voltage shift of MOS capacitor subjected to electron injection and shift of Fowler-Nordheim (FN) curve in high field region. Results indicate that the nitrided samples have particularly higher interface trap density at 0.43eV (below the conduction band of silicon) and a larger capture cross section than the conventional oxides, and the estimated centroid of the trap distribution is very close to the silicon-oxide interface. In addition, the trapped charge density is found to have a strong dependence on the nitridation conditions, and is lower for higher oxide field due to an increase of detrapping rate. On the other hand, electron conduction in the nitrided oxide films is mainly governed by the FN mechanism in low field ($lt;7 MV/cm) region and by the Pool-Frankel mechanism in highfield region where the traps assist the conduction.

Use of glecaprevir/pibrentasvir in patients with chronic hepatitis C virus infection and severe renal impairment

Desmond Y. H. Yap,Kevin S. H. Liu,Yu-Chun Hsu,Grace L. H. Wong,Ming-Chang Tsai,Chien-Hung Chen,Ching-Sheng Hsu,Yee Tak Hui,Michael K. K. Li,Chen-Hua Liu,Yee-Man Kan,Ming-Lung Yu,Man-Fung Yuen 대한간학회 2020 Clinical and Molecular Hepatology(대한간학회지) Vol.26 No.4

Background/Aims: Data on treatment efficacy and safety of glecaprevir/pibrentasvir (GLE/PIB) for chronic hepatitis C virus (HCV) infection in Asian patients with severe renal impairment are limited. This study aimed to study the treatment and side effects of GLE/PIB in these patients infected with non-1 genotype (GT) HCV. Methods: We prospectively recruited patients with Child’s A cirrhosis and eGFR <30 mL/min/1.73 m2 in Hong Kong and Taiwan during 2017–2018 to receive GLE/PIB treatment. Results: Twenty-one patients (GT2, n=7; GT3, n=6; and GT6, n=8) received GLE/PIB for 11.2±1.8 weeks. All except one were treatment-naïve. GLE/PIB was initiated in 16 patients while on dialysis (seven on peritoneal dialysis [PD] and nine on hemodialysis) and in five patients before dialysis. One patient died of PD-related peritonitis during treatment and two were lost to follow up. The SVR12 rate in the remaining 18 patients was 100%. All patients achieved undetectable levels at 4-, 12-, 24- and 48-week after treatment. Patients with deranged alanine aminotransferase showed normalization after 4 weeks and the response was sustained for 48 weeks. No significant adverse event was observed. Conclusions: GLE/PIB treatment was associated with high efficacy and tolerability in HCV-infected patients with severe renal impairment.

Brain metastases in Asian HER2-positive breast cancer patients: anti-HER2 treatments and their impact on survival

Yap, Y S,Cornelio, G H,Devi, B C R,Khorprasert, C,Kim, S B,Kim, T Y,Lee, S C,Park, Y H,Sohn, J H,Sutandyo, N,Wong, D W Y,Kobayashi, M,Landis, S H,Yeoh, E M,Moon, H,Ro, J Nature Publishing Group 2012 The British journal of cancer Vol.107 No.7

<P><B>Background:</B></P><P>In Asia, large-scale studies on anti-HER2 treatment in HER2-positive breast cancer patients with brain metastases are limited. We studied the treatment patterns of these patients in Asia to evaluate the impact of anti-HER2 treatment on the time to occurrence of brain metastases (TTBM) and survival after brain metastasis (BM).</P><P><B>Methods:</B></P><P>A retrospective study of HER2-positive breast cancer patients diagnosed with BM between January 2006 and December 2008 in six Asian countries was conducted. Demographics, tumour characteristics, treatment details, and events dates were collected from medical records.</P><P><B>Results:</B></P><P>Data from 280 patients were analysed. Before BM, 63% received anti-HER2 treatment. These patients had significantly longer TTBM than those without anti-HER2 treatment (median 33 <I>vs</I> 19 months; <I>P</I><0.002). After BM, 93% received radiotherapy, 57% received chemotherapy, and 41% received anti-HER2 treatment (trastuzumab and/or lapatinib). Use of both anti-HER2 agents, primarily sequentially, after BM demonstrated the longest survival after BM and was associated with a significant survival benefit over no anti-HER2 treatment (median 26 <I>vs</I> 6 months; hazard ratio 0.37; 95% CI 0.19–0.72).</P><P><B>Conclusion:</B></P><P>Anti-HER2 treatment before BM was associated with longer TTBM. Anti-HER2 treatment after BM was associated with a survival benefit, especially when both trastuzumab and lapatinib were utilised.</P>

MOLECULAR AND ATOMIC GAS IN THE LARGE MAGELLANIC CLOUD. II. THREE-DIMENSIONAL CORRELATION BETWEEN CO AND H I

Fukui, Y.,Kawamura, A.,Wong, T.,Murai, M.,Iritani, H.,Mizuno, N.,Mizuno, Y.,Onishi, T.,Hughes, A.,Ott, J.,Muller, E.,Staveley-Smith, L.,Kim, S. IOP Publishing 2009 The Astrophysical journal Vol.705 No.1

<P>We compare the CO (J = 1-0) and HI emission in the Large Magellanic Cloud in three dimensions, i.e., including a velocity axis in addition to the two spatial axes, with the aim of elucidating the physical connection between giant molecular clouds (GMCs) and their surrounding Hi gas. The CO J = 1-0 data set is from the second NANTEN CO survey and the HI data set is from the merged Australia Telescope Compact Array ( ATCA) and Parkes Telescope surveys. The major findings of our analysis are as follows: (1) GMCs are associated with an envelope of HI emission, (2) in GMCs [average CO intensity] proportional to [ average Hi intensity](1.1 +/- 0.1), and (3) the HI intensity tends to increase with the star formation activity within GMCs, from Type I to Type III. An analysis of the HI envelopes associated with GMCs shows that their average line width is 14 km s(-1) and the mean density in the envelope is 10 cm(-3). We argue that the HI envelopes are gravitationally bound by GMCs. These findings are consistent with a continual increase in the mass of GMCs via HI accretion at an accretion rate of 0.05 M-circle dot yr(-1) over a timescale of 10 Myr. The growth of GMCs is terminated via dissipative ionization and/or stellar-wind disruption in the final stage of GMC evolution.</P>

Party Competition and Ideology in Hong Kong: A New Manifesto Coding Dataset

Mathew Y. H. Wong 동아시아연구원 2020 Journal of East Asian Studies Vol.20 No.2

This study provides a new dataset on the ideological positions of political parties in Hong Kong, which is a hybrid regime with electoral elements. Using this dataset, the study challenges the non-ideological view of party competition in Hong Kong by identifying an ideological dimension to the elections held between 1998 and 2016. It is shown that parties do position themselves along an identifiable left–right spectrum, with shifts that can be meaningfully interpreted, and that the aggregate ideology of the electorate appears to be linked to the level of economic growth. The ideological dimension provides a novel perspective on local politics that looks beyond the dominant pro-democracy versus pro-Beijing divide while also shedding light on the recent changes underlying the latter. This study provides valuable objective data for analyzing political competition dynamics and contributes to the comparative literature by incorporating Hong Kong into the framework of the manifesto coding project.

Predictors of urosepsis in struvite stone patients after percutaneous nephrolithotomy

Justin Y.H. Chan,Victor K.F. Wong,Julie Wong,Ryan F. Paterson,Dirk Lange,Ben H. Chew,Kymora B. Scotland 대한비뇨의학회 2021 Investigative and Clinical Urology Vol.62 No.2

Purpose: This study aims to identify clinical factors that may predispose struvite stone patients to urosepsis following percutaneous nephrolithotomy (PCNL). Materials and Methods: A retrospective review was conducted on patients who received PCNL for struvite stones. The Systemic Inflammatory Response Syndrome (SIRS) criteria and quick-Sepsis Related Organ Failure Assessment (q-SOFA) criteria were used to identify patients who were at an increased risk for urosepsis. Statistical analysis was performed using Fisher's exactness test, Wilcoxon rank test, and logistic regression. Results: Chart review identified 99 struvite stone patients treated with PCNL. Post-operatively, 40 patients were SIRS positive (≥2 criteria) and/or q-SOFA positive (score ≥2). Using SIRS as an approximation for urosepsis, longer operative times (p<0.001), higher pre-operative white blood cell counts (p=0.01), greater total stone surface area (p<0.0001), and pre-operative stenting (OR, 5.75; p=0.01) were identified as independent risk factors for urosepsis. Multivariate analysis demonstrated pre-operative stenting (OR, 1.46; p=0.01) to be a risk factor. With q-SOFA, univariable analysis found that antibiotic use within 3 months prior to a PCNL (OR, 4.44; p=0.04), medical comorbidities (OR, 4.80; p=0.02), longer operative times (p<0.001), lengthier post-operative hospitalization (p<0.01), and greater total stone surface area (p<0.0001) were risk factors for urosepsis. Multivariate analysis revealed that bladder outlet obstruction (OR, 2.74; p<0.003) and pre-operative stenting (OR, 1.27; p=0.01) significantly increased odds of being q-SOFA positive. Conclusions: Several risk factors for urosepsis following PCNL for struvite stones have been identified. These risk factors should be taken into consideration in peri-operative care to mitigate the risks of urosepsis.

What attracts young people to become teachers? A comparative study of pre-service student teachers’ motivation to become teachers in Hong Kong and Macau

Tang Sylvia Y. F.,Wong P. M.,Wong Angel K. Y.,Cheng May M. H. 서울대학교 교육연구소 2018 Asia Pacific Education Review Vol.19 No.3

This article reports a comparative study on the reasons for pre-service student teachers becoming teachers in Hong Kong and Macau. The study adopted a mixed methods research design, with 459 and 137 student teachers completing a questionnaire on teaching motivation and 35 and 15 student teachers joining a follow-up interview in Hong Kong and Macau, respectively. The study found that student teachers in both societies share commonality in their altruistic and intrinsic motivations, i.e. a sense of vocation. The difference in student teachers’ motivation reflects the contrasting perceptions of teachers’ work and the teaching profession in connection with the different educational systemic factors in Macau and Hong Kong. Government-initiated quantitative expansion and quality enhancement in education set the backdrop of an aspiring teaching profession with promising prospects as perceived by the student teachers in Macau. In contrast, the move towards "centralized-decentralization" with a focus on excellence, competition and accountability in education at a time of teacher surplus results in a demanding profession with gloomy prospects as perceived by the Hong Kong student teachers. These differences add to our understanding of how the development trajectories of different education systems and teaching professions influence young people’s motivation to become teachers in different societies. The study also provides insights for initial teacher education and offers suggestions for the education communities of the two societies.