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Fulltext Prevalence and correlates of chronic diseases in an elderly population: A community-based survey in Haikou

Zhao C, Wong L, Zhu Q, Yang H

PLoS One, 2018;13(6):e0199006.
PMID: 29902222 DOI: 10.1371/journal.pone.0199006

BACKGROUND: The escalating problem of multiple chronic conditions among older adults in China draws public health attention due to increasing proportion of the elderly population. This study sought to assess the prevalence of and factors associated with four chronic diseases in older adults in Haikou, the capital city of Hainan Province, China.
METHOD: In this cross-sectional study, 9432 community-dwelling elderly people aged 60 years and older living in rural or urban areas in Haikou were investigated. The interviews collected self-reported information on the presence of four major chronic diseases, as well as socio-demographic characteristics, lifestyle factors and self-reported height and weight.
FINDINGS: Overall, 31.7% (2961/9344) reported at least one of the four chronic diseases. The prevalence of hypertension, diabetes mellitus, COPD, and stroke was 26.0% (2449/9407), 8.0% (749/9371), 1.0% (95/9360), and 1.9% (175/9382), respectively. Common correlates of the four major chronic diseases were older age, being engaged in intellectual work, currently being a smoker and obesity. Gender, locality of residence, and alcohol consumptions were also found to be associated to some of the chronic conditions.
CONCLUSION: This finding indicates that multiple chronic conditions among elderly people in Haikou are prevalent and warrant special attention to reduce diseases burden and align health care services to cater the holistic elderly patients' need.
Effective Response Metric: a novel tool to predict relapse in childhood acute lymphoblastic leukaemia using time-series gene expression profiling

Yeoh AE, Li Z, Dong D, Lu Y, Jiang N, Trka J, et al.

Br J Haematol, 2018 Jun;181(5):653-663.
PMID: 29808917 DOI: 10.1111/bjh.15252

Accurate risk assignment in childhood acute lymphoblastic leukaemia is essential to avoid under- or over-treatment. We hypothesized that time-series gene expression profiles (GEPs) of bone marrow samples during remission-induction therapy can measure the response and be used for relapse prediction. We computed the time-series changes from diagnosis to Day 8 of remission-induction, termed Effective Response Metric (ERM-D8) and tested its ability to predict relapse against contemporary risk assignment methods, including National Cancer Institutes (NCI) criteria, genetics and minimal residual disease (MRD). ERM-D8 was trained on a set of 131 patients and validated on an independent set of 79 patients. In the independent blinded test set, unfavourable ERM-D8 patients had >3-fold increased risk of relapse compared to favourable ERM-D8 (5-year cumulative incidence of relapse 38·1% vs. 10·6%; P = 2·5 × 10-3 ). ERM-D8 remained predictive of relapse [P = 0·05; Hazard ratio 4·09, 95% confidence interval (CI) 1·03-16·23] after adjusting for NCI criteria, genetics, Day 8 peripheral response and Day 33 MRD. ERM-D8 improved risk stratification in favourable genetics subgroups (P = 0·01) and Day 33 MRD positive patients (P = 1·7 × 10-3 ). We conclude that our novel metric - ERM-D8 - based on time-series GEP after 8 days of remission-induction therapy can independently predict relapse even after adjusting for NCI risk, genetics, Day 8 peripheral blood response and MRD.
Fulltext Risk of all-cause and CHD mortality in women versus men with type 2 diabetes: a systematic review and meta-analysis

Xu G, You D, Wong L, Duan D, Kong F, Zhang X, et al.

Eur J Endocrinol, 2019 Apr;180(4):243-255.
PMID: 30668524 DOI: 10.1530/EJE-18-0792

Objective: Previous studies have shown sex-specific differences in all-cause and CHD mortality in type 2 diabetes. We performed a systematic review and meta-analysis to provide a global picture of the estimated influence of type 2 diabetes on the risk of all-cause and CHD mortality in women vs men.
Methods: We systematically searched PubMed, EMBASE and Web of Science for studies published from their starting dates to Aug 7, 2018. The sex-specific hazard ratios (HRs) and their pooled ratio (women vs men) of all-cause and CHD mortality associated with type 2 diabetes were obtained through an inverse variance-weighted random-effects meta-analysis. Subgroup analyses were used to explore the potential sources of heterogeneity.
Results: The 35 analyzed prospective cohort studies included 2 314 292 individuals, among whom 254 038 all-cause deaths occurred. The pooled women vs men ratio of the HRs for all-cause and CHD mortality were 1.17 (95% CI: 1.12-1.23, I2 = 81.6%) and 1.97 (95% CI: 1.49-2.61, I2 = 86.4%), respectively. The pooled estimate of the HR for all-cause mortality was approximately 1.30 in articles in which the duration of follow-up was longer than 10 years and 1.10 in articles in which the duration of follow-up was less than 10 years. The pooled HRs for all-cause mortality in patients with type 2 diabetes was 2.33 (95% CI: 2.02-2.69) in women and 1.91 (95% CI: 1.72-2.12) in men, compared with their healthy counterparts.
Conclusions: The effect of diabetes on all-cause and CHD mortality is approximately 17 and 97% greater, respectively, for women than for men.
Fulltext Acceptance and Preference for COVID-19 Vaccine among Japanese Residents at Early Stage of the Epidemic in Japan

Wu J, Cai G, Fan Y, Arima K, Lin Y, Wong L, et al.

Vaccines (Basel), 2023 Jan 11;11(1).
PMID: 36680002 DOI: 10.3390/vaccines11010157

Background: This study aimed to survey the attitudes toward COVID-19 vaccines and their acceptability among the Japanese public as soon as the United States Food and Drug Administration (FDA) authorized vaccines and their rollouts started around the world. Methods: An anonymous cross-sectional survey was conducted in Japan between 4 January and 5 March 2021. A questionnaire was administered to evaluate attitudes toward COVID-19 vaccines according to demographic characteristics, vaccine characteristics, and vaccine production. Results: A total of 1037 completed responses were received. More than half (63.5%) of the participants responded positively (extremely likely/likely) toward COVID-19 vaccines. The highest acceptance to be vaccinated was discovered among the youngest age group. As expected, participants who had never delayed acceptance or refused the vaccine in their history of vaccination had a significantly higher willingness to be vaccinated against COVID-19 (p < 0.001). Females (OR = 2.66, 95% CI: 1.99−3.58) and participants who had ever delayed acceptance or refuse the vaccine (OR = 3.49, 95% CI: 2.42−5.05) had higher odds of COVID-19 vaccine hesitancy. Participants with a postgraduate degree (OR = 0.64, 95% CI: 0.40−1.00) presented the highest willingness to be vaccinated against COVID-19. More than two-thirds (72.9%, 95% CI: 70.4%−75.8%) of the participants did not mind a booster dose required following primary vaccination. A total of 63.2% (95% CI: 60.0%−66.0%) of the participants only accepted a nearly 90% effective or above vaccine at preventing COVID-19. At the same, 86.4% (95% CI: 84.4%−88.4%) of the participants reported only accepting a vaccine with minor side effects. Conclusions: The moderate levels of COVID-19 vaccine acceptance found in the early phase of the pandemic demonstrate that it is important to improve the implementation of effective management for vaccine promotion and the acceptability of the vaccine to slow or delay transmission.
Fulltext Knowledge, belief and barriers to adult influenza and pneumococcal vaccination among primary care doctors in Sarawak

Wong, L. K. S., Muthupalaniappen, L., Tie, S. T.

Medicine & Health, 2017;12(2):275-285.
MyJurnal

Adult influenza and pneumococcal vaccinations are grossly underutilized although there is clear benefit in reducing mortality and morbidity among those at risk. The aim of the study was to assess primary care physician’s knowledge on adult influenza and pneumococcal vaccinations, their beliefs and barriers to vaccination. A cross-sectional study using self-administered questionnaires was conducted at eight primary care centres in Kuching, Sarawak. A total of 108 primary care physicians participated in this study. Median age of participants was 29 years (IQR 4.0). The median knowledge score for influenza vaccine was 9 (IQR 3) and for pneumococcal vaccine was 8 (IQR 4). Female participants scored higher compared to their male counterparts for influenza and pneumococcal vaccines (P = 0.005 & 0.007). The highest percentage of correct responses for influenza vaccination was for side effects (75.3%) while the lowest was for contraindications (9.3%). The highest percentage of correct responses for pneumococcal vaccination was for side effects (69.1%) while the lowest was for advocated target groups (6.2%). Most participants believed that pneumococcal and influenza vaccines were safe (92.8 & 99%) and beneficial for patients (89.7 & 93.8%). Cost of influenza and pneumococcal vaccines (94.8% & 96.9%) and their availability (86.6% & 89.7%) were the main barriers to prescribing them. Primary care physicians in the public sector have moderate knowledge of both adult vaccinations. Areas of knowledge paucity and barriers need to be addressed to ensure a more comprehensive health care delivery to the aging Malaysian population.
Keywords: adult, belief, influenza vaccines, knowledge, pneumococcal vaccines
Fulltext Germinoma of the basal ganglia and thalamus--CT and MRI findings

Wong LW, Jayakumar CR

Singapore Med J, 1997 Oct;38(10):444-6.
PMID: 9529959

A case of germinoma originating in the basal ganglia and thalamus is presented. This tumour most commonly originates during childhood and adolescence, at pineal and suprasellar regions. In the early stages, the diagnosis of germinoma in the basal ganglion and thalamus is difficult because of its rarity and non-specific findings. The computed tomography (CT) and magnetic resonance imaging (MRI) findings though non-diagnostic, are discussed here. A few differential diagnoses had been discussed with radiological abnormality. Open biopsy done in this case proved to be two-cell pattern germinoma. Early detection of the tumour is desirable, since this tumour is highly sensitive to radio and chemotherapy and is potentially curable. Our patient was treated with combined chemotherapy and the response was well and no residual tumour or recurrence was seen on the repeated imaging modality, however his neurological deficits remained unchanged.
Management of velopharyngeal insufficiency by modified Furlow palatoplasty with pharyngeal flap: a retrospective outcome review

Wong LS, Lim E, Lu TC, Chen PKT

Int J Oral Maxillofac Surg, 2019 Jun;48(6):703-707.
PMID: 30755357 DOI: 10.1016/j.ijom.2019.01.010

The surgical approach for the correction of residual velopharyngeal insufficiency requiring secondary surgery at Chang Gung Memorial Hospital is the modified Furlow palatoplasty with pharyngeal flap (mFP-PF). The aim of this study was to describe the mFP-PF technique and to determine the results obtained with regard to improvements in velopharyngeal function in patients undergoing this surgery. This retrospective analysis included 58 non-syndromic patients treated during the period 1992-2015 who complained of hypernasal speech after primary cleft palate repair and failed postoperative speech therapy. All of them underwent mFP-PF surgery. Preoperative and postoperative perceptual speech assessment results were obtained. The male to female ratio in the study group was 1.2:1, and the mean patient age at the time of surgery was 8.27 years. The patients underwent nasoendoscopic examination and the velar closing ratio was categorized as 0.1-0.4 in 53.4% and 0.5-0.7 in 46.6%. The assessment of speech after mFP-PF showed statistically significant changes for all perceptual speech outcomes. The incidence of repeat surgery was 3.4%. This study revealed that 96.6% of patients did not require second surgery for velopharyngeal insufficiency. Further studies on obstructive sleep apnoea in post-mFP-PF patients and improvements to the surgical technique should be considered.
Fulltext Vaccine hesitancy and the resurgence of vaccine preventable diseases: the way forward for Malaysia, a Southeast Asian country

Wong LP, Wong PF, AbuBakar S

Hum Vaccin Immunother, 2020 07 02;16(7):1511-1520.
PMID: 31977285 DOI: 10.1080/21645515.2019.1706935

This study engaged health professionals in in-depth, semi-structured interviews to explore their opinions concerning the issues surrounding vaccine hesitancy in Malaysia and strategies to improve vaccination to stamp the rise of vaccine preventable diseases (VPDs). Opinions on how to address the resurgence of VPDs in the era of increasing vaccine hesitancy were obtained. Eight health professionals, including geriatricians, pediatricians, microbiologists, public health specialists, and family medicine specialists were interviewed. The influence of anti-vaccination propaganda, past-experience of adverse event following immunization (AEFI), perceived religious prohibition, a belief that traditional complementary and alternative medicine (TCAM) use is safer, pseudoscience beliefs, and anti-vaccine conspiracy theories were identified as reasons for refusing to vaccinate. The interplay of social, cultural and religious perspectives in influencing perceived religious prohibition, pseudoscience beliefs, and the use of TCAM contributing to vaccine refusal was found. Five broad themes emerged from the health professionals regarding strategies to address vaccine hesitancy, including establishing an electronic vaccination registry, increasing public awareness initiatives, providing feedback to the public on the findings of AEFI, training of front-line healthcare providers, and banning the dissemination of anti-vaccine information via social media. With regards to identifying strategies to address the resurgence of VPDs, mandatory vaccination received mixed opinions; many viewed supplementary immunization activity and the prevention of travel and migration of unvaccinated individuals as being necessary. In conclusion, the present study identified unique local cultural, traditional and religious beliefs that could contribute to vaccine hesitancy in addition to issues surrounding vaccination refusal similarly faced by other countries around the world. This information are important for the formulation of targeted intervention strategies to stamp vaccine hesitancy in Malaysia which are also a useful guide for other countries especially in the Southeast Asia region facing similar vaccine hesitancy issues.
Are Boys Ready for Human Papillomavirus Vaccine? A National Study of Boys in Malaysia

Wong LP, Alias H, Yusoff RNARM, Sam IC, Zimet GD

Sex Transm Dis, 2019 09;46(9):617-624.
PMID: 31181035 DOI: 10.1097/OLQ.0000000000001024

BACKGROUND: The aim of this study was to investigate factors associated with the willingness of boys to accept the human papillomavirus (HPV) vaccine.
METHODS: A nationwide cross-sectional survey among Secondary One male students in Malaysia.
RESULTS: Among 2823 respondents, knowledge about HPV infection and the HPV vaccine was extremely poor. The mean total knowledge score was only 3.17 (SD ± 2.14), out of a possible score of 10. The majority of respondents were unaware that vaccinating boys can help protect girls against HPV infection (81.6%), and HPV is a sexually transmitted infection (70.1%). Many had the misconception that only females get HPV (78.9%). In multivariable analysis, the factors associated with the intention to receive the HPV vaccination were: agreeing boys need to be vaccinated against HPV infection (odds ratio [OR], 2.05; 95% confidence interval [CI], 1.57-2.68), perceiving their parents might allow them to get the HPV vaccine (OR, 1.66; 95% CI, 1.18-2.34), perceived susceptibility to HPV infection (OR, 1.63; 95% CI, 1.06-2.52), and attending a rural school (OR, 1.49; 95% CI, 1.14-1.95).
CONCLUSIONS: Public health educational programs that are focused and tailored on parents consenting to HPV vaccination for boys at a young age can be useful in improving HPV vaccination rates among boys. There is also a pressing need to educate boys about the benefits of HPV vaccination in males and about HPV disease susceptibility to facilitate adoption of the HPV vaccine by young adults in the future.
Government Dental Services in Sarawak, East Malaysia

Wong LM

Dent Update, 1992 Dec;19(10):430-2.
PMID: 1303358

As part of the student elective, the author organized a small research project into Government Dental Services in Sarawak, East Malaysia. The resulting article gives an insight into dentistry in this country.
Fulltext Neuroendocrine tumour masquerading as intussusception: A case report

Wong L, Kanthasamy SV, Durairaj G, Thangaratnam RR

Int J Surg Case Rep, 2020;77:48-52.
PMID: 33137672 DOI: 10.1016/j.ijscr.2020.10.091

INTRODUCTION: Intussusception usually occurs in the paediatric population. When it occurs in the adult population, it is normally caused by a malignant intraluminal pathology.
PRESENTATION OF CASE: A 72-year-old female presented to us with right-sided abdominal pain for 3 weeks, associated with vomiting and diarrhoea. She had an appendectomy done 30 years ago and a recent myocardial infarction. Abdominal examination revealed a previous appendectomy scar and tenderness over the right lumbar region. Computed tomography showed ileocaecal intussusception. Right hemicolectomy with a double barrel stoma was performed as she was unstable intraoperatively. Histopathological examination of the tumour showed a well-differentiated neuroendocrine tumour. Subsequent PET scan showed no systemic disease and a reversal of the stoma was done. She remained disease free for a year.
DISCUSSION: Our patient had undergone a right hemicolectomy despite the high risk of mortality, as there is a high chance of malignancy. Double barrel stoma was done, as she was unstable intraoperatively. Fortunately, she recovered well and had her stoma reversed without any further recurrence of her disease.
CONCLUSION: Adult patients who present with intussusception should be managed with resection, as there is a high possibility of a malignancy. Early resection should be planned to prevent further spread of the tumour.
Promotion of Adolescent Mental Health in Hong Kong-The Role of a Comprehensive Child Health Policy

Wong L, Chan CW

J Adolesc Health, 2019 06;64(6S):S14-S18.
PMID: 31122544 DOI: 10.1016/j.jadohealth.2019.01.033
Systematic review of excision and grafting in burns: Comparing outcomes of early and late surgery in low and high-income countries

Wong L, Rajandram R, Allorto N

Burns, 2021 Jul 07.
PMID: 34303572 DOI: 10.1016/j.burns.2021.07.001

INTRODUCTION: While the benefits of early excision in burn surgery are clear, the advantages may be lost in low income countries with limited resources. It is important to identify the right timing of excision in different groups of patients, particularly those in low-income countries (LIC), as the burden of disease contributes to the highest global mortality and has the least resources. This systematic review and meta-analysis aims to determine the timing of excision in LICs and the outcomes associated with surgery: (1) mortality, (2) sepsis and (3) length of stay (LOS) compared to high income countries (HICs).
METHODOLOGY: The PRISMA guidelines and MOOSE checklist were followed for this review. Publications in English from year 1990 to 2017 that included data on the timing and type of burn surgery and outcomes were included. Searches were done using Web of Science, Cochrane collaboration and Pubmed using keywords "Burn and surgery", "Burn and excision", "Burn and excision and grafting" and "burn and skin grafting". Trial quality was evaluated using the Newcastle-Ottawa scale. Outcomes compared for early and late excisions were length of stay (LOS), sepsis and mortality between LICs and HICs.
RESULTS: From 278 citations, we selected 41 for full text evaluation, and identified 16 eligible trials. LOS is shorter in early excision compared to late excision in both LICs and HICs. Mortality is lower in late excision compared to early excision in both LICs and HICs. Further subgroup analysis of elderly patients in HICs confirmed that mortality is lower in late excision and unchanged if the elderly are excluded. Early excision reduces sepsis in both LIC and HIC.
DISCUSSION: The variable definitions of age, timing of excision, variable nature of % TBSA comparison, mixed inclusion of inhalation injury, co-morbidities and unquantified access to resources make the data difficult to interpret and it is not possible to draw accurate conclusions on the role of early excision for burns in low-middle income countries. A prospective study is needed in order to answer this question.
Data analysis in qualitative research: a brief guide to using nvivo

Wong L

Malays Fam Physician, 2008;3(1):14-20.
PMID: 25606106 MyJurnal

Qualitative data is often subjective, rich, and consists of in-depth information normally presented in the form of words. Analysing qualitative data entails reading a large amount of transcripts looking for similarities or differences, and subsequently finding themes and developing categories. Traditionally, researchers 'cut and paste' and use coloured pens to categorise data. Recently, the use of software specifically designed for qualitative data management greatly reduces technical sophistication and eases the laborious task, thus making the process relatively easier. A number of computer software packages has been developed to mechanise this 'coding' process as well as to search and retrieve data. This paper illustrates the ways in which NVivo can be used in the qualitative data analysis process. The basic features and primary tools of NVivo which assist qualitative researchers in managing and analysing their data are described.
A curious case of neuromyelitis optica spectrum disorder co-existing with idiopathic intracranial hypertension

Viswanathan S, Wong LC

J Clin Neurosci, 2017 07;41:104-106.
PMID: 28343917 DOI: 10.1016/j.jocn.2017.03.026
Fulltext Clinical Significance of BCL2, C-MYC, and BCL6 Genetic Abnormalities, Epstein-Barr Virus Infection, CD5 Protein Expression, Germinal Center B Cell/Non-Germinal Center B-Cell Subtypes, Co-expression of MYC/BCL2 Proteins and Co-expression of MYC/BCL2/BCL6 Proteins in Diffuse Large B-Cell Lymphoma: A Clinical and Pathological Correlation Study of 120 Patients

Ting CY, Chang KM, Kuan JW, Sathar J, Chew LP, Wong OJ, et al.

Int J Med Sci, 2019;16(4):556-566.
PMID: 31171907 DOI: 10.7150/ijms.27610

Background: Clinical significance of germinal center B-cell (GCB) and non-GCB sub-categorization, expression of MYC, BCL2, BCL6, CD5 proteins and Epstein Barr virus encoded RNA (EBER) positivity in diffuse large B-cell lymphoma (DLBCL) remain controversial. Could these biomarkers accurately identify high risk DLBCL patients? Are MYC, BCL2 and BCL6 proteins expression feasible as baseline testing to predict c-Myc, BCL2 or BCL6 gene rearrangements? Aims: To investigate prognostic values of GCB/non-GCB sub-categorization, Double Protein Expression Lymphoma (DPL), Triple Protein Expression Lymphoma (TPL), positivity of CD5 protein and EBER in patients with DLBCL disease. To evaluate correlation between BCL2 , c-Myc and BCL6 gene rearrangements with BCL2, MYC and BCL6 proteins expression. Methods: Diagnostic tissue samples of 120 DLBCL patients between January 2012 to December 2013 from four major hospitals in Malaysia were selected. Samples were subjected to immunohistochemical staining, fluorescent in-situ hybridization (FISH) testing, and central pathological review. Pathological data were correlated with clinical characteristics and treatment outcome. Results: A total of 120 cases were analysed. Mean age of diagnosis was 54.1 years ± 14.6, 64 were males, 56 were females, mean follow up period was 25 months (ranged from 1 to 36 months). Of the 120 cases, 74.2% were non-GCB whereas 25.8% were GCB, 6.7% were EBER positive, 6.7% expressed CD5 protein, 13.3% were DPL and 40% were TPL. The prevalence of c-Myc, BCL2, BCL6 gene rearrangements were 5.8%, 5.8%, and 14.2%, respectively; and 1.6% were Double Hit Lymphoma (DHL). EBER positivity, DPL, TPL, c-Myc gene rearrangement, BCL2 gene rearrangement, extra copies of BCL2 gene and BCL6 gene rearrangement were associated with shorter median overall survival (P<0.05). IPI score was the significant determinants of median overall survival in DPL and TPL (P<0.05). CD5 protein expression and GCB/non-GCB sub-categorization did not affect treatment outcome (P>0.05). Overall, c-Myc, BCL2 and BCL6 gene rearrangements showed weak correlation with expression of MYC, BCL2 and BCL6 proteins (P>0.05). Fluorescent in situ hybridization is the preferred technique for prediction of treatment outcome in DLBCL patients. Conclusion:c-Myc, BCL2, and BCL6 gene rearrangements, EBER expression, DHL, TPL and IPI score are reliable risk stratification tools. MYC, BCL2 and BCL6 proteins expression are not applicable as baseline biomarkers to predict c-Myc, BCL2, and BCL6 gene rearrangements.
Molecular basis of transfusion dependent beta-thalassemia major patients in Sabah

Teh LK, George E, Lai MI, Tan JA, Wong L, Ismail P

J Hum Genet, 2014 Mar;59(3):119-23.
PMID: 24369358 DOI: 10.1038/jhg.2013.131

Beta-thalassemia is one of the most prevalent inherited diseases and a public health problem in Malaysia. Malaysia is geographically divided into West and East Malaysia. In Sabah, a state in East Malaysia, there are over 1000 estimated cases of β-thalassemia major patients. Accurate population frequency data of the molecular basis of β-thalassemia major are needed for planning its control in the high-risk population of Sabah. Characterization of β-globin gene defects was done in 252 transfusion dependent β-thalassemia patients incorporating few PCR techniques. The study demonstrates that β-thalassemia mutations inherited are ethnically dependent. It is important to note that 86.9% of transfusion-dependent β-thalassemia major patients in Sabah were of the indigenous population and homozygous for a single mutation. The Filipino β(0)-deletion was a unique mutation found in the indigenous population of Sabah. Mutations common in West Malaysia were found in 11 (4.3%) patients. Four rare mutations (Hb Monroe, CD 8/9, CD 123/124/125 and IVS I-2) were also found. This study is informative on the population genetics of β-thalassemia major in Sabah.
Calculation of energy recovery and greenhouse gas emission reduction from palm oil mill effluent treatment by an anaerobic granular-sludge process

Show KY, Ng CA, Faiza AR, Wong LP, Wong LY

Water Sci Technol, 2011;64(12):2439-44.
PMID: 22170839 DOI: 10.2166/wst.2011.824

Conventional aerobic and low-rate anaerobic processes such as pond and open-tank systems have been widely used in wastewater treatment. In order to improve treatment efficacy and to avoid greenhouse gas emissions, conventional treatment can be upgraded to a high performance anaerobic granular-sludge system. The anaerobic granular-sludge systems are designed to capture the biogas produced, rendering a potential for claims of carbon credits under the Kyoto Protocol for reducing emissions of greenhouse gases. Certified Emission Reductions (CERs) would be issued, which can be exchanged between businesses or bought and sold in international markets at the prevailing market prices. As the advanced anaerobic granular systems are capable of handling high organic loadings concomitant with high strength wastewater and short hydraulic retention time, they render more carbon credits than other conventional anaerobic systems. In addition to efficient waste degradation, the carbon credits can be used to generate revenue and to finance the project. This paper presents a scenario on emission avoidance based on a methane recovery and utilization project. An example analysis on emission reduction and an overview of the global emission market are also outlined.
Smile Attractiveness and Treatment Needs of Maxillary Midline Diastema with Various Widths: Perception among Laypersons, Dental Students, and Dentists in Malaysia

Sabri NABM, Ridzwan SBB, Soo SY, Wong L, Tew IM

Int J Dent, 2023;2023:9977868.
PMID: 37095900 DOI: 10.1155/2023/9977868

Smile attractiveness and the need for treatment of maxillary midline diastema with various widths are perceived differently between dentally trained and nondentally trained individuals of different sociodemographic backgrounds. This study aims to evaluate how laypersons, dental students, and dentists in Malaysia differ in their perceptions on smile attractiveness and treatment needs of maxillary midline diastema. A smiling photograph with well-aligned maxillary central incisors with proportionate width-to-height ratio and healthy gingival tissues was selected and digitally manipulated to create maxillary midline diastema with 0.5, 2.0, and 4.0 mm widths. The smile attractiveness and the perceived need for treatment of varying widths of maxillary midline diastemas were rated by laypersons, dental students, and dentists using the Likert scale via a single set of self-administered questionnaires. The impact of sociodemographic variables on aesthetic perception of different gap widths was tested using univariate analysis followed by a multiple linear regression model. A total of 158 laypersons, 118 dental students, and 138 dentists participated in this study. Both laypersons and dentists showed significantly higher mean aesthetic scores for 0.5 mm maxillary midline diastema, lower mean aesthetic scores, and hence higher mean treatment needs scores for 4.0 mm maxillary midline diastema as compared with dental students (p < 0.05). In general, female respondents perceived a gap width of up to 2.0 mm as aesthetically pleasing. Higher educational group and the Malay ethnicity had tolerance threshold of 0.5 mm gap width. The older group considered 4.0 mm gap width as aesthetically unpleasing. In conclusion, both laypersons and dentists accepted a 0.5 mm maxillary midline diastema as an attractive smile but considered 4.0 mm maxillary midline diastema as unpleasing smile which required treatment. Perceptions of laypersons and dentists were significantly different from dental students. Educational level, gender, ethnicity, and age were significantly associated with smile attractiveness of maxillary midline diastema at different investigated widths.
Fulltext Thermal and Flame Retardant Behavior of Neem and Banyan Fibers When Reinforced with a Bran Particulate Epoxy Hybrid Composite

Raja T, Mohanavel V, Sathish T, Djearamane S, Velmurugan P, Karthick A, et al.

Polymers (Basel), 2021 Nov 09;13(22).
PMID: 34833158 DOI: 10.3390/polym13223859

Awareness of environmental concerns influences researchers to develop an alternative method of developing natural fiber composite materials, to reduce the consumption of synthetic fibers. This research attempted testing the neem (Azadirachta indica) fiber and the banyan (Ficus benghalensis) fiber at different weight fractions, under flame retardant and thermal testing, in the interest of manufacturing efficient products and parts in real-time applications. The hybrid composite consists of 25% fiber reinforcement, 70% matrix material, and 5% bran filler. Their thermal properties-short-term heat deflection, temperature, thermal conductivity, and thermal expansion-were used to quantify the effect of potential epoxy composites. Although natural composite materials are widely utilized, their uses are limited since many of them are combustible. As a result, there has been a lot of focus on making them flame resistant. The thermal analysis revealed the sample B was given 26% more short-term heat resistance when the presence of banyan fiber loading is maximum. The maximum heat deflection temperature occurred in sample A (104.5 °C) and sample B (99.2 °C), which shows a 36% greater thermal expansion compared with chopped neem fiber loading. In sample F, an increased chopped neem fiber weight fraction gave a 40% higher thermal conductivity, when compared to increasing the bidirectional banyan mat of this hybrid composite. The maximum flame retardant capacity occurred in samples A and B, with endurance up to 12.9 and 11.8 min during the flame test of the hybrid composites.

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