MyMedR

Fulltext Numerical modelling of molten carbonate fuel cell: effects of gas flow direction in anode and cathode

Tay C. L., Law M. C.

Pertanika Journal of Science & Technology, 2014;22(2):645-655.

MyJurnal

The modelling of a three-dimensional (3-D) molten carbonate fuel cell (MCFC) was developed to study the effects of gas flow direction (co-flow and counter-flow) in anode and cathode on the generated power density by solving the mass and momentum conservation equations, electrochemical reaction and heat transfer. The simulation result of the co-flow temperature distribution was compared with the experimental data obtained from open literature. The molar fraction distribution of gases in the anode and cathode gas channels and temperature distribution across the cell were compared between two different flow directions. Furthermore, the performance of MCFC, which operates in the temperature range of 823 - 1023 K, was analysed by comparing the generated power density. The results showed that MCFC with co-flow attained higher power density compared to that of counter-flow at 873 K. However, at higher temperature of 1023 K, the generated power density was the same for both gas flow directions.

Reliability Assessment and Activation Energy Study of Au and Pd-Coated Cu Wires Post High Temperature Aging in Nanoscale Semiconductor Packaging

Gan CL, Hashim U

Journal of electronic packaging, 2013 Jun;135(2):0210101-210107.

PMID: 24891811

Wearout reliability and high temperature storage life (HTSL) activation energy of Au and Pd-coated Cu (PdCu) ball bonds are useful technical information for Cu wire deployment in nanoscale semiconductor device packaging. This paper discusses the influence of wire type on the wearout reliability performance of Au and PdCu wire used in fine pitch BGA package after HTSL stress at various aging temperatures. Failure analysis has been conducted to identify the failure mechanism after HTSL wearout conditions for Au and PdCu ball bonds. Apparent activation energies (Eaa) of both wire types are investigated after HTSL test at 150 °C, 175 °C and 200 °C aging temperatures. Arrhenius plot has been plotted for each ball bond types and the calculated Eaa of PdCu ball bond is 0.85 eV and 1.10 eV for Au ball bond in 110 nm semiconductor device. Obviously Au ball bond is identified with faster IMC formation rate with IMC Kirkendall voiding while PdCu wire exhibits equivalent wearout and or better wearout reliability margin compare to conventional Au wirebond. Lognormal plots have been established and its mean to failure (t50) have been discussed in this paper.

Prevalence and clinical significance of antibodies to ribonucleoproteins in systemic lupus erythematosus in Malaysia

Wang CL, Ooi L, Wang F

Br J Rheumatol, 1996 Feb;35(2):129-32.

PMID: 8612023

One hundred and seventy patients with systemic lupus erythematosus (SLE) were studied for the prevalence of antibodies to the small RNA-associated proteins Ro/SSA, La/SSB, Sm, U1RNP and Sm. The relationship of these autoantibodies to different races, sexes and clinical manifestations of SLE was evaluated. Passive immunodiffusion was employed using human spleen extract as antigen source for Ro and rabbit thymus extract for La, Sm and U1RNP. We found the prevalence of antibodies to be as follows: anti-Ro/SSA, 36%; anti-La/SSB, 8%; anti-Sm, 15% ; anti-U1RNP, 21%. Except for a low prevalence of anti-La, the prevalence of these antibodies was similar to that in Western studies, The prevalence of anti-Ro/SSA is similar to that reported in the Western studies, but lower than that reported in the Oriental patients from Singapore and Hong Kong. Linkages of anti-Ro with anti-La antibodies were usual; however, although anti-Sm antibodies were usually associated with anti-U1RNP, they were more frequently associated with anti-Ro antibodies. The Malay patients had a high prevalence of anti U1RNP compared to other races. No gender difference was detected. Anti-Sm antibody was associated with serositis and anti-U1RNP antibodies with Raynaud's phenomenon. No association was found between the presence of skin renal or cerebral manifestations and any specific antibodies or combination of antibodies.

Changes in body fluid distribution in experimental protein malnutrition

Chandrasekharan N, Ho CL

Med J Malaysia, 1976 Jun;30(4):266-72.

PMID: 824533

A clinicopathologic study of 173 odontogenic tumours in Northern Peninsular Malaysia (2007-2014)

Ismail S, Saw CL

Malays J Pathol, 2018 Aug;40(2):129-135.

PMID: 30173229 MyJurnal

INTRODUCTION: The objectives of this study were to analyse, compare and contrast the demographic, clinical and pathological data of odontogenic tumours seen at a regional oral pathology centre in the Northern part of Peninsular Malaysia with other international data as an aid to clinicians in diagnosing odontogenic tumours.

MATERIALS AND METHODS: This was a descriptive, retrospective study of odontogenic tumours diagnosed from January 2007 to December 2014 at this centre. The odontogenic tumours were classified using the 2005 World Health Organization classification system.

RESULTS: Among 2,733 biopsy specimens, 173 cases were diagnosed as odontogenic tumours (6.3%), of which 171 (98.8%) are benign and 2 (1.2%) are malignant. The most frequently encountered tumour was ameloblastoma (n=96, 55.5%), followed by keratocystic odontogenic tumour (KCOT) (n=38, 22.0%) and odontomas (n=16, 9.2%). Malignant tumours accounted for 1.2% of the tumours. Most ameloblastomas and KCOTs affected the mandible preferentially. The mean age was 33.5 (± 17.8) years and 64.7% of patients were in the age group of 10 to 39. Odontogenic tumours were slightly more common in males, with a male to female ratio of 1.4:1.

CONCLUSION: The findings of this study are similar to the other studies in Asia in which the most common tumour encountered is the ameloblastoma, followed by KCOT. The most common signs and symptoms are pain and swelling, while paraesthesia and root resorption are less frequently reported. Such clinical and radiographic features should alert the clinician of a possible odontogenic tumour and though rare, malignant tumours should also be included in the differential diagnoses.

Fulltext Spirit possession in an Indian family--a case report

Teoh CL, Dass D

Singapore Med J, 1973 Mar;14(1):62-4.

PMID: 4713020

Spirit possession in an Indian family is described. Its importance as a culture-bound phenomenon is stressed. Its nature as a hysteria, and as a culturally sanctioned and accepted means of expression of emotions and feelings, are discussed.

August 1993 theme issues: tuberculosis

Teng CL, Kuppusamy I, Ahmad Mahayiddin A

Family Physician, 1994;6:47-8.

Pain and culture: a brief review

Teng CL, Kamil MA, Abu Hassan Z

Family Physician, 2005;13:2-4.

Fulltext HbA1c as an indicator of diabetic control in the Family Practice Clinic

Wong KC, Teng CL, Krishnan R

Family Physician, 1996;9(3):3-6.

A quality assurance exercise for non-insulin dependent diabetes mellitus in the Family Practice Clinic, University Hospital Kuala Lumpur, was conducted using HbA1c as an indicator. We found that about 60% of the 163 patients with non-insulin dependent diabetes mellitus had fair to optimal control. The HbA1c correlated well with fasting and post-prandial blood glucose level (r=0.79 and r=0.54, respectively, p<0.001). The mean HbA1c was significantly higher in Malay compared to the other races, in those with longer duration of diabetes and in patients on two types of oral hypoglycaemic agent.
Study site: Family Practice Clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia

The development of an enterococcal phage assay for water samples

Ngeow YF, Loh CL, Wang CW

JUMMEC, 1996;1:25-28.

Preliminary work was carried out f o r the development of a rapid method for the detection and enumeration of enterococcal phages in natural water. Eight enterococcal phages were isolated after amplification from water obtained from 2 local ponds. These were plaque-purified and used to test the phage susceptibility of 34 strains of enterococci isolated from pristine and polluted waters. Eight strains with the widest phage susceptibility were used as hosts in a double agar layer (DAL) and a single agar layer (SAL) assay for phage enumeration without pre-assay amplification. N o phages were obtained with the DAL method with all 8 hosts. Usingthe SALmethod, 2 phages were obtained with 1 of the 2 hosts used. Phage isolation was not improved by incubation at 44.5°C. For rapid quantitative testing, the sensitivity of the assays has to be increased to enable phage isolation without the need for prior amplification. KEYWORDS: Enterococci, phage, enumeration

A prospective audit of Desflurane anaesthesia in the University of Malaya Medical Centre Day Surgery Unit

Chiu CL, Mansor M, Wang CY

JUMMEC, 2005;8:45-49.

We evaluated the use of Desflurane anaesthesia in this prospective observational audit in the University of Malaya Medical Centre Day Surgery Unit. Fifty ASA I-II unpremedicated day surgery patients received fentanyl and propofol induction after preoxygenation. Desflurane was introduced initially at 2% and the concentration was increased gradually to 4%, then 6%, 8% and 10% in nitrous oxide and oxygen. Patients breathed spontaneously throughout the surgery. Desflurane was switched off at the end of surgery and patients breathed 100% oxygen. The haemodynamic effect, perioperative complications and recovery profiles were recorded. Systolic arterial pressure and heart rate decreased after induction of anaesthesia but returned to baseline value at discharge. Adverse airway event such as coughing and postoperative nausea and vomiting are two unwanted complications. KEYWORDS: Desflurane, day surgery, propofol induction

Molecular defense response of oil palm to Ganoderma infection

Ho CL, Tan YC

Phytochemistry, 2015 Jun;114:168-77.

PMID: 25457484 DOI: 10.1016/j.phytochem.2014.10.016

Basal stem rot (BSR) of oil palm roots is due to the invasion of fungal mycelia of Ganoderma species which spreads to the bole of the stem. In addition to root contact, BSR can also spread by airborne basidiospores. These fungi are able to break down cell wall components including lignin. BSR not only decreases oil yield, it also causes the stands to collapse thus causing severe economic loss to the oil palm industry. The transmission and mode of action of Ganoderma, its interactions with oil palm as a hemibiotroph, and the molecular defence responses of oil palm to the infection of Ganoderma boninense in BSR are reviewed, based on the transcript profiles of infected oil palms. The knowledge gaps that need to be filled in oil palm-Ganoderma molecular interactions i.e. the associations of hypersensitive reaction (HR)-induced cell death and reactive oxygen species (ROS) kinetics to the susceptibility of oil palm to Ganoderma spp., the interactions of phytohormones (salicylate, jasmonate and ethylene) at early and late stages of BSR, and cell wall strengthening through increased production of guaiacyl (G)-type lignin, are also discussed.

Antiphospholipid syndrome in Sarawak: real world experience in a developing country

Teh CL, Leong TS

Clin Rheumatol, 2015 Jan;34(1):175-8.

PMID: 24831689 DOI: 10.1007/s10067-014-2671-6

We performed a cross-sectional study of all antiphospholipid syndrome (APS) patients during an 8-year period (2006-2013) to describe the clinical features, serology profiles, treatment regimes, and outcomes in our center. There were a total of 59 patients in our study with the female to male ratio of 9:1. They have a mean age of 41.6 ± 12.1 years and a mean duration of illness of 38.4 ± 68.5 months. The majority of patients presented with vascular thrombosis (69.5 %) with equal arterial and venous involvements. Twenty-six patients (44.1 %) presented with obstetric complications with recurrent abortions (32.2 %) as the main manifestation. Most patients were on daily warfarin doses of 2-6 mg (91.0 %) with target INR of 2-3. There was neither recurrent thrombosis nor bleeding complications documented. There were 80 % live births following treatment in our patients.

Causes and predictors of mortality in hospitalized lupus patient in Sarawak General Hospital, Malaysia

Teh CL, Ling GR

Lupus, 2013 Jan;22(1):106-11.

PMID: 23112253 DOI: 10.1177/0961203312465780

Systemic lupus erythematosus (SLE) is a serious autoimmune disease that can be life threatening and fatal if left untreated. Causes and prognostic indicators of death in SLE have been well studied in developed countries but lacking in developing countries. We aimed to investigate the causes of mortality in hospitalized patients with SLE and determine the prognostic indicators of mortality during hospitalization in our center. All SLE patients who were admitted to Sarawak General Hospital from January 1, 2006 to December 31, 2010, were followed up in a prospective study using a standard protocol. Demographic data, clinical features, disease activities and damage indices were collected. Logistic regression and Cox regression analysis were used to determine the prognostic indicators of mortality in our patients. There were a total of 251 patients in our study, with the female to male ratio 10 to 1. Our study patients were of multiethnic origins. They had a mean age of 30.5 ± 12.2 years and a mean duration of illness of 36.5 ± 51.6 months. The main involvements were hematologic (73.3%), renal (70.9%) and mucocutaneous (67.3%). There were 26 deaths (10.4%), with the main causes being: infection and flare (50%), infection alone (19%), flare alone (19%) and others (12%). Independent predictors of mortality in our cohort of SLE patients were the presence of both infection and flare of disease (hazard ratio (HR) 5.56) and high damage indices at the time of admission (HR 1.91). Infection and flare were the main causes of death in hospitalized Asian patients with SLE. The presence of infection with flare and high damage indices at the time of admission were independent prognostic indicators of mortality.

Effects of microwave radiation on house dust mites, Dermatophagoides pteronyssinus and Dermatophagoides farinae (Astigmata: Pyroglyphidae)

Ernieenor FC, Ho TM

Southeast Asian J. Trop. Med. Public Health, 2010 Nov;41(6):1335-41.

PMID: 21329308

Dermatophagoides pteronyssinus and Dermatophagoides farinae mites are commonly found in house dust, and are important sources of allergens affecting humans. Various approaches to killing the mites have been examined. This study investigated the mortalities of adult mites exposed to 2,450 MHz microwave radiation produced by 3 ovens at various exposure times and power settings. The ovens all had 3 power settings. The average maximum water temperatures generated at high, medium and low power settings were 99.4 +/- 0.2, 84.1 +/- 0.4 and 44.8 +/- 0.9 degrees C, respectively. At high and medium settings, there was 100.0% mortality in both species when exposed for 300 seconds. The mean mortality rates at low power were 10.8 +/- 0.7% for D. pteronyssinus and 9.7 +/- 2.6% for D. farinae. When mites were exposed in the presence of culture media, the mortality rates decreased with increasing weight of media. The mean mortality with the largest amount of media tested at high power setting was 61.4%.

The pattern and clinical manifestations of rheumatoid arthritis in Sarawak General Hospital

Teh CL, Wong JS

Clin Rheumatol, 2008 Nov;27(11):1437-40.

PMID: 18773254 DOI: 10.1007/s10067-008-0945-6

The aim of our study is to describe the pattern, clinical features, treatment regimes, and disease activity among the patients treated for rheumatoid arthritis (RA) in the Sarawak General Hospital. We performed a cross-sectional study of all patients with a diagnosis of RA who received treatment at the General Medical Clinic and the Rheumatology Clinic in Sarawak General Hospital over a 1-year period from 1st June 2006 to 31st May 2007. Demographic data, clinical features, and disease activity of all 154 patients were collected for statistical analysis. Rheumatoid arthritis afflicts all the major racial groups in Sarawak including the native population. Our patients have a mean disease duration of 5.4 years (SD 5.69) and a mean duration of delay in diagnosis RA and initiation of disease-modifying antirheumatic drug (DMARD) treatment of 42.9 months (SD 60.1). They have a low rate of interstitial lung disease (6.5%) and rheumatoid nodules (4.5%). Rheumatoid factor was positive in 65.5% of our patients. They have a mean Disease Activity Score (DAS) 28 score of 4.28 (SD 1.33). Only 12.5% of our patients are in remission with DAS 28 < 2.6 and 30.9% of our patients are having high disease activity with DAS 28 > 5.1. Despite the high usage of DMARDs in Sarawak (>80%), our patients have severe disease with high disease activity indices. This is most likely due to delay in diagnosis and initiating DMARDs in RA patients in Sarawak.

Study site: General Medical Clinic and the Rheumatology Clinic in Sarawak General Hospital

Fulltext Imaging of Osteo-odontokeratoprosthesis(OOKP) Using Multidetector Computed Tomography: A UKMMC Experience

Abu Bakar N, Lee CL

Med J Malaysia, 2013;68(1):73-5.

PMID: 23466774

Osteo-odontokeratoprosthesis (OOKP) surgery is a technique used to replace damaged cornea in blind patients for whom cadaveric transplantation is not feasible. OOKP surgery is a complex procedure requiring lifetime follow-up. The preservation of the osteo-odontolamina is the vital feature in maintaining the stability of the OOKP. Early detection of lamina resorption enables early prophylactic measures to be taken and prevent resorption-related complications. This case illustrates the radiological findings of the first OOKP surgery in Malaysia and the role of multidetector computed tomography (MDCT) in postoperative management of OOKP surgery.

Sevoflurane for dental extraction in children with Tetralogy of Fallot

Chiu CL, Wang CY

Paediatr Anaesth, 1999;9(3):268-70.

PMID: 10320610

Two children with Tetralogy of Fallot presented for dental extraction. Anaesthesia was induced rapidly and smoothly by inhalation of sevoflurane. We discussed the advantages of sevoflurane as an induction agent as compared to halothane in these children.

The use of modified VBM laryngeal tube compared to Laryngeal Mask Airway during spontaneous ventilation

Chiu CL, Murugasu J, Chan L

Anaesth Intensive Care, 2003 Apr;31(2):187-92.

PMID: 12712784

We have compared the use of the laryngeal mask airway with the new modified laryngeal tube in a prospective randomized controlled study. Sixty ASA 1 or 2 patients, aged 18 to 65 years, scheduled for elective surgery and breathing spontaneously under general anaesthesia, were studied. After preoxygenation, anaesthesia was induced with fentanyl and propofol. The patients were randomized to receive either a laryngeal mask airway or a laryngeal tube. Anaesthesia was maintained with nitrous oxide, oxygen and isoflurane. We recorded the speed and the ease of insertion, the number of attempts needed to successfully secure the airway and intraoperative complications, such as partial airway obstruction needing airway manipulation. The airway devices were removed with the patients fully awake at the end of surgery. Systolic arterial blood pressure, heart rate and end-tidal CO2 were recorded at various time intervals. Postoperative complications were recorded. We found that the incidence of partial airway obstruction needing intraoperative airway manipulation was higher with the laryngeal tube than with the laryngeal mask airway. We conclude that during spontaneous ventilation the modified laryngeal tube is not as reliable in providing a satisfactory airway and we consider it is not a suitable alternative to the laryngeal mask airway.

Subcutaneous emphysema and pneumomediastinum after endotracheal anaesthesia

Chiu CL, Ong GS

Ann Acad Med Singap, 2000 Mar;29(2):256-8.

PMID: 10895351

INTRODUCTION: We report a case of subcutaneous emphysema and pneumomediastinum that presented postoperatively after tracheal extubation.

CLINICAL PICTURE: A 51-year-old man had an uneventful anaesthesia lasting about 6.5 hours. Intubation was performed by a very junior medical officer and was considered difficult. He developed sore throat, chest pain, numbness of both hands and palpable crepitus around the neck postoperatively. Chest X-ray revealed diffuse subcutaneous emphysema, pneumomediastinum and possible pneumopericardium.

TREATMENT: He was treated conservatively with bed rest, oxygen, analgesia, antibiotic prophylaxis, reassurance and close monitoring.

OUTCOME: The patient made an uneventful recovery.

CONCLUSIONS: We discussed the possible causes.

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