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Fulltext Unsupervised bivariate data clustering for damage assessment of carbon fiber composite laminates

May Z, Alam MK, Mahmud MS, Rahman NAA

PLoS One, 2020;15(11):e0242022.
PMID: 33186372 DOI: 10.1371/journal.pone.0242022

Damage assessment is a key element in structural health monitoring of various industrial applications to understand well and predict the response of the material. The big uncertainty in carbon fiber composite materials response is because of variability in the initiation and propagation of damage. Developing advanced tools to design with composite materials, methods for characterizing several damage modes during operation are required. While there is a significant amount of work on the analysis of acoustic emission (AE) from different composite materials and many loading cases, this research focuses on applying an unsupervised clustering method for separating AE data into several groups with distinct evolution. In this paper, we develop an adaptive sampling and unsupervised bivariate data clustering techniques to characterize the several damage initiations of a composite structure in different lay-ups. An adaptive sampling technique pre-processes the AE features and eliminates redundant AE data samples. The reduction of unnecessary AE data depends on the requirements of the proposed bivariate data clustering technique. The bivariate data clustering technique groups the AE data (dependent variable) with respect to the mechanical data (independent variable) to assess the damage of the composite structure. Tensile experiments on carbon fiber reinforced composite laminates (CFRP) in different orientations are carried out to collect mechanical and AE data and demonstrate the damage modes. Based on the mechanical stress-strain data, the results show the dominant damage regions in different lay-ups of specimens and the definition of the different states of damage. In addition, the states of the damage are observed using Scanning Electron Microscope (SEM) analysis. Based on the AE data, the results show that the strong linear correlation between AE and mechanical energy, and the classification of various modes of damage in all lay-ups of specimens forming clusters of AE energy with respect to the mechanical energy. Furthermore, the validation of the cluster-based characterization and improvement of the sensitivity of the damage modes classification are observed by the combined knowledge of AE and mechanical energy and time-frequency spectrum analysis.
Group B streptococcus: maternal carriage rate and early neonatal septicaemia

Lim CT, Thong MK, Parasakthi N, Ngeow YF

Ann Acad Med Singap, 1997 Jul;26(4):421-5.
PMID: 9395802

Between January 1984 and December 1994, 30 cases of early neonatal group B streptococcus (GBS) septicaemia were managed in the Neonatal Unit, University Hospital, Kuala Lumpur. Two neonates were outborn and 28 were inborn, giving an average annual incidence of neonatal GBS septicaemia of 0.4/1000 livebirths among inborn babies. In a separate survey over a three-month period, GBS genital carriage rate among 196 parturients was found to be 9.7%. Of the infants with GBS septicaemia, the mean gestational age was 37.5 +/- 3.8 weeks and the mean birthweight was 2540 +/- 716 g. Twelve (40%) were preterm infants and 14 (47%) were low birthweight infants. Male and female infants were almost equally affected. Prolonged rupture of membranes and maternal pyrexia accounted for only 5 (17%) and 3 (10%) of the cases respectively. Twenty-four (80%) neonates had onset of symptoms within 6 hours of life and respiratory symptoms were observed in 24 (80%) of the cases, while meningitis was uncommon. Six (20%) neonates died. Preterm and low birthweight infants had higher mortality than their term counterparts: 42% versus 6% and 36% versus 6% respectively. Of those who died, 4 (67%) required respiratory support right from birth and the mean time of onset of symptoms was 4 hours (range 0 to 21 hours) and the duration of survival was only 28.8 hours (range 12 to 38 hours). As the incidence of neonatal GBS septicaemia was low, mass screening and chemoprophylaxis for GBS were not recommended. All the GBS isolates were sensitive to penicillin and ampicillin, thus one of these antibiotics should be included in the antimicrobial therapy of septic neonates.
Dengue-associated adult respiratory distress syndrome

Lum LC, Thong MK, Cheah YK, Lam SK

Ann Trop Paediatr, 1995 Dec;15(4):335-9.
PMID: 8687212 DOI: 10.1080/02724936.1995.11747794

In dengue shock syndrome, an acute increase in capillary permeability results in leakage of plasma into the interstitial space. Pleural effusion is commonly seen in dengue shock syndrome. We report three cases of dengue-associated adult respiratory distress syndrome (ARDS) in children, in all of whom dengue haemorrhagic fever, presenting with grade 3 or grade 4 dengue shock syndrome with disseminated intravascular coagulopathy, was confirmed. The criteria for the diagnosis of ARDS were based on the expanded definition of ARDS by Murray et al. Treatment consisted of fluid resuscitation, correction of coagulopathy and mechanical ventilation. All three children had multi-organ impairment, but it was more severe in the two who died. The one survivor was well at discharge.
Early post-traumatic seizures in children: clinical and radiological aspects of injury

Ong LC, Dhillon MK, Selladurai BM, Maimunah A, Lye MS

J Paediatr Child Health, 1996 Apr;32(2):173-6.
PMID: 9156530

OBJECTIVE: To determine the type and outcome of early post-traumatic seizures in children and the factors associated with it.
METHODOLOGY: A prospective observational study on all consecutive children with head injuries at the General Hospital Kuala Lumpur between November 1993 and December 1994. The onset, type and frequency of seizures occurring within the first week of injury were documented. Using inpatients as a cohort, logistic regression analysis was used to determine clinical and radiological variables significantly associated with seizures. The outcome 6 months post-injury was assessed using the Glasgow Outcome Scale.
RESULTS: Fifty-three of 966 children (5.5%) developed seizures within the first week of trauma. Seven (13.2%) occurred within 1 h of injury, 30 (56.6%) between 1 and 24 h and 16 (30.2%) after 24 h. Factors significantly associated with early post-traumatic seizures were female sex, age less than 2 years, loss of consciousness for more than 24h and acute subdural haematoma (P<0.01). Children with seizures had a poorer outcome (death or severe disability) than inpatients without seizures (21/53 vs 19/182, P<0.001). The outcome was worst in children with recurrent partial seizures, who had a longer injury-seizure interval and were more likely to have focal neurologic deficits compared to those with sporadic or generalized seizures.
CONCLUSIONS: Anticonvulsant prophylaxis to minimize the adverse effects of early seizures in head injury should be considered for young children (less than 2 years old) with subdural haematoma and a prolonged duration of coma. Prompt and effective control of recurrent seizures is recommended.
The prognostic value of the Glasgow Coma Scale, hypoxia and computerised tomography in outcome prediction of pediatric head injury

Ong L, Selladurai BM, Dhillon MK, Atan M, Lye MS

Pediatr Neurosurg, 1996 Jun;24(6):285-91.
PMID: 8988493

The outcome of 151 children less than 15 years of age and admitted within 24 h of head injury was studied in relation to clinical and computed tomography (CT) scan features. Thirty one (20.5%) had a poor outcome (24 died, 6 were severely disabled at 6 months after injury and 1 was in a persistent vegetative state) while 120 (79.5%) had a good outcome (89 recovered well and 31 were moderately disabled). Factors associated with a poor outcome were Glasgow Coma Scale (GCS) score 24 h following injury, presence of hypoxia on admission and CT scan features of subarachnoid haemorrhage, diffuse axonal injury and brain swelling. GCS scores alone, in the absence of other factors, had limited predictive value. The prognostic value of GCS scores < 8 was enhanced two-to fourfold by the presence of hypoxia. The additional presence of the CT scan features mentioned above markedly increased the probability of a poor outcome to > 0.8, modified only by the presence of GCS scores > 12. Correct predictions were made in 90.1% of patients, indicating that it is possible to estimate the severity of a patient's injury based on a small subset of clinical and radiological criteria that are readily available.
Treatment with flecainide for symptomatic and refractory tachyarrhythmias in children

Ismail Z, Alwi M, Lim MK, Murtazam HA, Jamaluddin A

Acta Paediatr Jpn, 1994 Feb;36(1):44-8.
PMID: 8165907

Nine children, aged 2.5 months to 16 years, presenting with tachyarrhythmias were treated with intravenous (i.v.) flecainide, a type 1C antiarrhythmic drug. There were four boys and five girls; seven were supraventricular and two ventricular tachycardias and three had structural cardiac abnormalities. The i.v. dose required to terminate the arrhythmias ranged from 1.0 to 2.4 mg/kg (mean 1.55 mg/kg) although a mean of 1.94 mg/kg per dose was required to maintain sustained sinus rhythm after a single i.v. dose. Eight of the patients--six supraventricular and two ventricular tachyarrhythmias, required maintenance oral flecainide. Oral dosages of 6.7-9.5 mg/kg per day (mean of 7.97 mg/kg per day in three divided doses) were required to effectively prevent the tachyarrhythmias. Intravenous and oral flecainide are safe and effective in terminating supraventricular and ventricular tachyarrhythmias. No evidence of proarrhythmia was found in the patients during follow up of between 5 and 9 months. The present limitation of performing radiofrequency ablation on infants and small children justifies the important place of medical therapy for re-entrant supraventricular tachyarrhythmias.
Fulltext Moyamoya disease in Malaysia: two documented cases

Ng WK, Tan CT, George J, Lee MK, Loh TG

Med J Malaysia, 1995 Jun;50(2):186-8.
PMID: 7565194

Moyamoya disease is a rare cause of young strokes. The definitive diagnosis of moyamayo disease is made by cerebral angiography. We report two cases of moyamoya disease in Malaysia.
Seasonal prevalence of air-borne pollen and spores in Kuala Lumpur, Malaysia

Ho TM, Tan BH, Ismail S, Bujang MK

Asian Pac J Allergy Immunol, 1995 Jun;13(1):17-22.
PMID: 7488339

Aerosampling using Rotorod samplers was conducted in the Institute for Medical Research, Kuala Lumpur, Malaysia, from December 1991 to November 1993. Samples were collected twice a week between 10.00 hours to 12.00 hours. Rods were stained and examined microscopically. A total of 8 and 20 types of pollens and mold spores were collected, respectively. More mold spores were collected than pollens. Grass pollen constituted more than 40 percent of total pollen counts. Gramineae pollen counts peaked in March and September. The most abundant mold spore was Cladosporium followed by Rust, Nigrospora, Curvularia and Smut. Cladosporium counts peaked in February and August. Rust counts peaked in June and December whereas counts for Nigrospora peaked in February and October. Highest counts of Smut were recorded in March and October. Curvularia counts peaked in January, June and September.
Fulltext Education and myopia in 110,236 young Singaporean males

Au Eong KG, Tay TH, Lim MK

Singapore Med J, 1993 Dec;34(6):489-92.
PMID: 8153707

Computerised data of 110,236 Singaporean males aged 15 to 25 (mean 17.75) years who underwent compulsory medical examination from April 1987 to January 1992 were used to estimate the prevalence and severity of myopia among young Chinese, Malay, Indian and Eurasian Singaporean males with different educational levels. The prevalence and severity of myopia amongst the groups with different educational levels were compared. These groups were fairly well-matched for important known confounding factors such as age, sex, race and degree of urbanisation of place of residence. Our data showed a positive association between educational attainment and both the prevalence and severity of myopia. Both the prevalence of myopia and the proportion of myopes with severe myopia were in general higher among those with more years of formal education.
The impact of a modified ileal neobladder on the lifestyle and voiding patterns in Asian patients

Lee KT, Li MK, Cheng WS, Foo KT

Br J Urol, 1998 May;81(5):705-8.
PMID: 9634045 DOI: 10.1046/j.1464-410x.1998.00586.x

OBJECTIVE: To evaluate the impact of the modified ileal neobladder reconstruction on lifestyle, voiding habits and functional outcome in Asian patients.

PATIENTS AND METHODS: Twenty-seven Asian patients (25 men and two women, mean age 59 years, range 41-76) underwent modified ileal neobladder reconstruction after radical cystectomy for carcinoma of the bladder. The mean (range) follow-up was 21 (3-75) months. All patients were evaluated retrospectively using case notes, reviews, interviews and voiding charts; 18 patients underwent urodynamic studies.

RESULT: Twenty-five patients (93%) achieved diurnal and 23 (85%) nocturnal continence within 6 months. Of the 19 patients who were in employment before surgery, 15 continued to be economically active afterward; 26 patients (96%) reported no change in their daily living activities. Of 16 men who reported being potent pre-operatively only four retained some residual erectile function. Twenty-three patients were interviewed about their voiding habits and satisfaction with the outcome of surgery. Fourteen patients had no sensation of reservoir fullness and of the 21 men, 13 had to squat or sit to void effectively. The mean (range) voiding frequency was 5 (4-8) during the day and 2 (0-4) during sleep. Twenty-two patients were satisfied with the overall outcome.

CONCLUSIONS: The modified ileal bladder provides a high urinary continence rate with minimal changes in daily living activities and occupational status. The functional outcome was very satisfactory and accepted well, despite some changes in reservoir sensation, voiding posture and erectile function. The method is a viable option for reconstruction after cystectomy in Asian patients.
Effects of des-aspartate-angiotensin I on the actions of angiotensin III in the renal and mesenteric vasculature of normo- and hypertensive rats

Mustafa MR, Dharmani M, Kunheen NK, Sim MK

Regul. Pept., 2004 Aug 15;120(1-3):15-22.
PMID: 15177916

An earlier study showed that des-aspartate-angiotensin I (DAA-I) attenuated the pressor action of angiotensin III in aortic rings of the spontaneously hypertensive rat (SHR) but not the normotensive Wistar Kyoto (WKY) rat. The present study investigated similar properties of DAA-I in isolated perfused kidneys and mesenteric beds of WKY and SHR. In the renal vasculature, angiotensin III induced a dose-dependent pressor response, which was more marked in the SHR than WKY in terms of significant greater magnitude of response and lower threshold. DAA-I attenuated the pressor action of angiotensin III in both the WKY and SHR. The attenuation in SHR was much more marked, occurring at doses as low as 10(-15) M DAA-I, while effective attenuation was only seen with 10(-9) M in WKY. The effects of DAA-I was not inhibited by PD123319 and indomethacin, indicating that its action was not mediated by angiotensin AT2 receptors and prostaglandins. However, the direct pressor action of angiotensin III in the SHR but not the WKY was attenuated by indomethacin suggesting that this notable difference could be due to known decreased response of renal vasculature to vasodilator prostaglandins in the SHR. Pressor responses to angiotensin III in the mesenteric vascular bed was also dose dependent, but smaller in magnitude compared to the renal response. The responses in the SHR, though generally smaller, were not significantly different from those of the WKY. This trend is in line with the similar observations with angiotensin III and II by other investigators. In terms of the effect of DAA-I, indomethacin and PD123319 on angiotensin III action, similar patterns to those of the renal vasculature were observed. This reaffirms that in the perfused kidney and mesenteric bed, where the majority of the vessels are contractile, femtomolar concentrations of DAA-I attenuates the pressor action of angiotensin III. The attenuation is not indomethacin sensitive and does not involve the angiotensin AT2 receptor. The findings suggest that DAA-I possesses protective vascular actions and is involved in the pathophysiology of hypertension.
Fulltext Spinal cord injury without radiological abnormality (SCIWORA)

Izma MKO, Zulkharnain I, Ramli B, Muhamad AR, Harwant S

Med J Malaysia, 2003 Mar;58(1):105-10.
PMID: 14556334

SCIWORA or Spinal Cord Injury Without Radiological Abnormality; is a pre-MRI term that includes injuries to the spinal cord in the absence of radiological (plain radiographs, tomographs and CT scans) evidence of injury to the spinal column or cord. It occurs in skeletally immature spines because of the inherent plasticity of the bony structures in this age group. The prognosis is dependent on the extent of cord damage, and the role of active management is limited. A high index of suspicion is needed to establish a diagnosis. This diagnostic accuracy can be improved with the free availability of MRI scanning for the spines. We describe three cases of SCIWORA with a minimum follow-up of three years and a review of current literature.
Fulltext APACHE II: preliminary report on 100 intensive care unit cases in University Hospital, Kuala Lumpur

Teoh GS, Mah KK, Majid S, Streram, Yee MK

Med J Malaysia, 1991 Mar;46(1):72-81.
PMID: 1836042

A good overall assessment of the severity of illnesses of patients admitted to a general intensive care unit (ICU) is not without problems. The APACHE (acute physiology and chronic health evaluation) prognostic scoring system enables us to stratify acutely ill patients and compare efficiency of ICU therapy in different hospitals. This preliminary study carried out on 100 consecutive admissions to the ICU in University Hospital, Kuala Lumpur showed the spectrum of ICU admissions and the direct relationship between APACHE II score and mortality.
Fulltext Neuroleptic malignant syndrome in Malaysia: a university hospital experience

Lee MK, Ong SB, Tan CT, Loh TG

Med J Malaysia, 1992 Sep;47(3):200-7.
PMID: 1362794

The neuroleptic malignant syndrome (NMS) is a potentially fatal complication of antipsychotic therapy. A retrospective study of nine patients seen over six years at the University Hospital, Kuala Lumpur (UHKL), is described. The estimated annualised incidence was 1.2 per 1000 in-patients with psychosis. No ethnic difference was detected. Clinical features were similar to experiences elsewhere, with wide variability seen in the severity of illness. The neuroleptic drugs implicated were haloperidol, trifluoperazine, chlorpromazine, fluphenazine and clopenthixol. Treatment consisted of withdrawal of offending drugs and supportive measures. Specific therapy was given to five patients. There was one death. At follow-up no deterioration was detected. A different neuroleptic drug was successfully re-introduced in four patients. In view of the wide usage of major tranquillizers, a high degree of clinical awareness of this serious complication is necessary for early diagnosis to reduce morbidity and mortality.
Bancroftian filariasis and malaria in island and hinterland populations in Sabah, Malaysia

Hii J, Kan S, Pereira M, Parmar SS, Campos RL, Chan MK

Trop Geogr Med, 1985 Jun;37(2):93-101.
PMID: 3898498

An epidemiological survey of filariasis and malaria in Banggi Island and Upper Kinabatangan, Sabah, revealed microfilarial rates of 7.2% and 8.6% respectively and malaria prevalence of 9.7% and 16.9% respectively. Wuchereria bancrofti was a rural nocturnally periodic type with a periodicity index of 137.2 and average peak hour at 01.32 hrs; 9.2% of microfilaremic carriers as compared to 2.4% amicrofilaremic subjects had clinical filariasis. The Plasmodium falciparum: P. vivax: P. malariae ratios were 1:1:0.17 and 1.4:1:0.12 for Banggi and Upper Kinabatangan respectively. Anopheles flavirostris was incriminated as a new malaria vector in Banggi where the well-known primary malaria vector is An. balabacensis. The latter was also found for the first time to be a vector of rural W. bancrofti in Upper Kinabatangan. Experimental feeding also showed that L3 larvae of W. bancrofti were recovered at low rates from An. balabacensis. Aedes togoi appeared to be a suitable laboratory vector for W. bancrofti.
Fulltext Comparison of the efficacy of single and multiple regimens of carbimazole in the treatment of thyrotoxicosis

Mafauzy M, Wan Mohamad WB, Zahary MK, Mustafa BE

Med J Malaysia, 1993 Mar;48(1):71-5.
PMID: 8341175

Carbimazole, in 3 divided daily doses, is commonly prescribed for the treatment of thyrotoxicosis. However, based on its long intra-thyroid half-life, the drug may be effective when used as a single or twice daily dose. This study was undertaken to determine the effect of once, twice or thrice daily doses of carbimazole on thyroid function in patients with thyrotoxicosis. Seventy previously untreated thyrotoxic patients were randomly allocated to receive carbimazole 30 mg once (group 1), 15 mg twice (group 2) and 10 mg thrice (group 3) daily. All patients were also prescribed propranolol 20 mg thrice daily for the first 4 weeks. Blood was taken for total T3, T4, TSH, blood counts and liver enzymes determinations at the beginning and at 6 weeks of treatment. Only 48 (68.6%) patients were included in the analysis, as the rest defaulted follow-up (20.0%) or blood samples were not available at review (11.4%). Of the 48 patients, 17 were in group 1, 16 in group 2 and 15 in group 3. Following 6 weeks of treatment, there was no significant difference in the mean serum levels of total T3 and T4 between the 3 groups. However, there was a significant decrease in the mean serum levels of total T3 and T4 as compared to the start of the treatment. Four patients (23.5%) in group 1, 4 patients (25%) in group 2 and 3 patients (20%) in group 3 were still thyrotoxic at 6 weeks of treatment, whilst 10 patients (58.8%) in group 1, 6 patients (37.5%) in group 2 and 3 (20%) in group 3 were biochemically hypothyroid.(ABSTRACT TRUNCATED AT 250 WORDS)
Nutritional status of Kadazan children in a rural district in Sabah, Malaysia

Gan CY, Chin B, Teoh ST, Chan MK

Southeast Asian J Trop Med Public Health, 1993 Jun;24(2):293-301.
PMID: 8266232

The nutritional status of 896 Kadazan children below 6 years of age from 23 villages of Tambunan District were studied. When stunting and wasting were defined as those who were below two standard deviations of height-for-age and weight-for-height (Waterlow et al, 1977) and based on the National Center for Health Statistics reference population, 67.6% of boys and 66.8% of girls were stunted while 12.3% of boys and 8.3% of girls were wasted. Weaning foods and toddler feeding practices were unsatisfactory. The role of health education on child care and feeding practices is emphasized.
Melioidosis, the great mimicker: a report of 10 cases from Malaysia

Yee KC, Lee MK, Chua CT, Puthucheary SD

J Trop Med Hyg, 1988 Oct;91(5):249-54.
PMID: 3184245

Between 1981 and 1986, 10 consecutive cases of melioidosis were seen at the University Hospital, Kuala Lumpur, Malaysia. They illustrate the amazing guises of melioidosis presenting as: abscesses of the supraspinatus muscle, psoas muscle, brain and liver; three different pulmonary forms; an acute suppurative dermal lesion; an acute septicaemia; and chronic lymphadenitis. The majority had underlying diseases: diabetes mellitus, the commonest, was present in six, out of whom three had previous pulmonary tuberculosis; other predisposing conditions were renal failure, corticosteroid therapy and malnutrition. Three patients who died had pre-existing renal impairment and developed renal failure later, suggesting that the former is a bad prognostic sign. Clinical diagnosis was difficult: all cases were diagnosed bacteriologically. A high level of clinical awareness is necessary, especially when presentation simulates pulmonary or extrapulmonary tuberculosis in patients with diabetes or other compromised states.
Anopheles (Cellia) balabacensis Baisas is a vector of Wuchereria bancrofti in Sabah, Malaysia

Hii JL, Kan S, Foh CK, Chan MK

Trans R Soc Trop Med Hyg, 1984;78(2):281-2.
PMID: 6380019
Fulltext Hepatitis B markers in heterosexuals involved in promiscuous sexual activity

Rajakumar MK, Ton SH, Lim KF, Oorloff KH

Med J Malaysia, 1984 Mar;39(1):65-8.
PMID: 6513842

179 heterosexuals, selected for VDRL testing on the basis of a history of involvement in promiscuous sexual activity, mainly prostitution, had their serum also tested for hepatitis B infection markers, HBsAg, HBeAg and anti-HBe. 51 samples (29%) were found to be positive for at least one of the three markers, at levels higher than the already high levels in voluntary random blood donors in Malaysia.

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