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Showing papers by "National University of Malaysia published in 1991"


Journal ArticleDOI
TL;DR: This paper introduces a four point explicit decoupled group (EDG) iterative method as a new Poisson solver and is shown to be very much faster compared to existing explicit group (EG) methods.
Abstract: The aim of this paper is to introduce a four point explicit decoupled group (EDG) iterative method as a new Poisson solver. The method is shown to be very much faster compared to existing explicit group (EG) methods due to D. J. Evans and M. J. Biggins (1982) and W. Yousif and D. J. Evans (1985). Some numerical experiments are included to confirm our recommendation.

209 citations


Journal ArticleDOI
TL;DR: It is suggested that tocotrienols administered to AAF-treated rats reduce the severity of hepatocarcinogenesis.

91 citations


Journal ArticleDOI
TL;DR: In this paper, an elongated basin was proposed for the deposition of Middle Eocene-Early Miocene sediments in Sabah during the Middle Oligocene-Middle Miocene.

91 citations


Journal ArticleDOI
TL;DR: Avoiding regular exposure to mosquito coil smoke and passive smoking could reduce the prevalences of persistent wheeze, asthma and chest illness by up to 29%.
Abstract: The effects of indoor environmental factors on respiratory illness were studied in 15017-12 year old school children in Kuala Lumpur. Exposure to mosquito coil smoke for at least three nights a week was independently associated with asthma and persistent wheeze. Passive smoking, defined as sharing a bedroom with an adult smoker, was independently associated with a chest illness in the past year. No relationships were found between exposure to kerosene stoves, wood stoves, fumigation mat mosquito repellents or aerosol insecticides and respiratory illness. Host factors predictive of at least one respiratory outcome included family history of chest illness, history of allergy, male sex, hospitalization in the neonatal period and low paternal education. With 95% confidence, avoidance of regular exposure to mosquito coil smoke and passive smoking could reduce the prevalences of persistent wheeze, asthma and chest illness by up to 29%. Measurements of lung function confirmed the validity of questions pertaining to wheezing and asthma in the study questionnaire.

72 citations


Journal ArticleDOI
TL;DR: The major alkaloids present in very young leaves of Mitragyna speciosa from Malaysia were shown to be highly conjugated indoles, mitragynaline and corynantheidaline, and two others were isolated and characterized.

51 citations


Journal ArticleDOI
TL;DR: A more realistic model of the variation of tree-ring widths is developed and the question of the development and use of national or regional chronologies is addressed.

50 citations


Journal ArticleDOI
TL;DR: Two major compounds have been isolated and characterized from the roots of Goniothalamus uvaroides : goniothalamin, a biologically active styryl dihydropyrone, and its derivative, 5-acetyl goni hypothalamin.

49 citations


Journal ArticleDOI
01 Nov 1991
TL;DR: The expert system is used as a preprocessor as well as a postprocessor to the truncated dynamic-programming based unit commitment program to obtain an operationally feasible and/or preferable solution.
Abstract: An expert system has been developed by combining the knowledge of experienced power system operators and unit commitment experts to assist operators in scheduling thermal generating units. The expert system is used as a preprocessor as well as a postprocessor to the truncated dynamic-programming based unit commitment program to obtain an operationally feasible and/or preferable solution. The operator's interaction with the expert system is minimised by transferring all the relevant data and results of the unit commitment program to the expert system as a knowledge base. Some of the complex operating constraints that are not violated frequently and/or are difficult to include in the unit commitment program are enforced by the expert system.

46 citations


Journal ArticleDOI
TL;DR: In this article, the effects of blanching and predrying treatments on the stability of carotenoids and anthocyanins in papaya ( Carica papaya var Subang) and pineapple ( Ananas comosus var Mauritius) were investigated.

36 citations


Journal ArticleDOI
TL;DR: In this paper, the standard homogeneous metathesis catalyst consisting of WCl 6 and Me 4 Sn in chlorobenzene as solvent was used for the transesterification of palm oil.

25 citations



Journal ArticleDOI
TL;DR: It is suggested that glucocorticoids but not mineralocortioid relieve bronchospasm at least partly by reducing the cholinergic hypersensitivity.
Abstract: 1. Glucocorticosteroid may relieve bronchospasm by mediating changes in the muscarinic receptor concentration and/or its affinity. 2. Cholinergic muscarinic receptors were determined by using Scatchard's plots from radioligand binding assays of 0.13-3.2 nM [3H]quinuclidinyl benzylate binding to the membrane fraction of bronchial smooth muscle (BSM). 3. The concentration of muscarinic receptor in BSM of normal rat was 57 +/- 3 fmol mg protein and the dissociation constant was 0.07 +/- 0.02 nM. Dexamethasone and corticosterone reduced muscarinic receptor concentration to 50-60% of basal with no changes in receptor affinity. No changes were found in rat treated with deoxycorticosterone. 4. These findings suggest that glucocorticoids but not mineralocorticoid relieve bronchospasm at least partly by reducing the cholinergic hypersensitivity.

Journal ArticleDOI
TL;DR: There is a need for better assessment of fetal size and maternal pelvimetry to enable earlier diagnosis of cephalo-pelvic disproportion, and review of the indications and techniques of breech delivery to reduce the occurrence of brachial plexus injuries.
Abstract: A prospective study was carried out on 26,176 Malaysian neonates born in the Maternity Hospital, Kuala Lumpur over a 12-month period to determine the incidence and associated risk factors of brachial plexus injuries. This condition was found in 42/26,176 neonates (1.6 per 1000 livebirths). Multiple logistic regression analysis of affected and control neonates from a nested case-control study showed that increasing birth weights and breech deliveries were the significant risk factors. Our study suggests that to reduce the occurrence of this condition, there is a need for: (i) better assessment of fetal size and maternal pelvimetry to enable earlier diagnosis of cephalo-pelvic disproportion, and (ii) review of the indications and techniques of breech delivery.

Journal ArticleDOI
TL;DR: A preliminary study on heavy metals contamination in fiddler crabs and hermit crabs was carried out as mentioned in this paper, which showed Pb and Cd concentrations were high whereas Zn and Cu concentrations were within the permissible limits.
Abstract: A preliminary study on heavy metals contamination in fiddler crabs and hermit crabs was carried out. As they are easily found in river mouth areas, they can probably serve as good indicators for heavy metals pollution. The results show Pb and Cd concentrations were high whereas Zn and Cu concentrations were within the permissible limits.

Journal Article
TL;DR: Two cases of acute renal failure that followed the ingestion of jering were reported, with clinical presentation of bilateral loin pain, fever, nausea, vomiting, oligo-anuria, haematuria and passage of sandy particles in the urine.
Abstract: We report two cases of acute renal failure that followed the ingestion of jering. Features of jering poisoning included clinical presentation of bilateral loin pain, fever, nausea, vomiting, oligo-anuria, haematuria and passage of sandy particles in the urine. Blood urea (40.8 mmol/l; 21.9 mmol/l) and serum creatinine (1249 mumols/l; 693 mumols/l) were markedly elevated. With conservative therapy which included rehydration with normal saline and alkalinisation of the urine with sodium bicarbonate, the acute renal failure resolved.

Journal ArticleDOI
TL;DR: In this article, a preliminary investigation on some concrete properties has been carried out, and it has been observed that, even though the required concrete strength in hot-humid climate is obtained, the elastic modulus could be reduced by a small extent.

Journal ArticleDOI
TL;DR: The gentamicin levels reached at the end of the thirtieth cycle were observed to be low and the risk of acute ototoxicity was considered to be minimal, and the absence of clinical audiometric or vestibulometric evidence of toxicity was confirmed.
Abstract: In a prospective study on 47 patients, 16 mg of gentamicin per two litres dialysate was administered intraperitoneally at every cycle of intermittent peritoneal dialysis, carried out over the course of several days. Serum gentamicin sampling, pure tone audiometry and caloric tests were performed before and during the treatment. The gentamicin levels reached at the end of the thirtieth cycle were observed to be low. In view of this, the risk of acute ototoxicity was considered to be minimal. This was confirmed by the absence of clinical audiometric or vestibulometric evidence of toxicity.



Journal Article
TL;DR: The difference in terms of smoking, drinking habit and dietary intake may determine the distribution of disease in both communities.
Abstract: Summary The socioeconomic, social behaviour and dietary pattern of 100 Aborigines and Malays, aged 7 years and above from Kuala Pangsoon , Selangor Malaysia were studied by using pretested questionnaires. The individual's dietary intake was estimated using 24 hour recall for 3 days within one week which was chosen at random. The household's food consumption pattern was evaluated using food frequency questionnaires. There was no difference in the total income per month for both communities, as well as the educational attainment of the head of household and property ownership. The proportion of smokers among the Aborigines and the Malays was almost similar ( 33 % ) but the percentage of heavy smokers was higher among Aborigines compared to Malays. One third of the Aborigines regularl y consume alcohol. The main energy source for both communities was rice, sugar and cooking oil whilst fish and eggs were the main sources of protein. More than 50 % of the Aborigines take tapioca or tapioca leaves at least once a week compared to less than 20 % among the Malays. There was no significant different in the intake of energy, protein and carbohydrate between the groups. However the Aborigines take less fats and iron compared to the Malays. The difference in terms of smoking, drinking habit and dietary intake may determine the distribution of disease in both communities.

Journal ArticleDOI
TL;DR: In this paper, a matching of red tide outbreaks with total monthly rainfall, monthly-averaged index of wind-induced surface water mixing, and monthlyaveraged upwelling index for the period from 1975 to 1989 failed to show any definite pattern.
Abstract: . Red tides of the toxic dinoflagellate Pyrodinium bahamense var. compressum have occurred almost annually since 1976 in the coastal waters of the west coast of Sabah, Malaysia. Field obServations have indicated that the timings of these outbreaks could be linked to meteorological forcings. All the red tides have occurred during either the northeast or southwest monsoon periods. Matching of red tide outbreaks with total monthly rainfall, monthly-averaged index of wind-induced surface water mixing, and monthly-averaged upwelling index for the period from 1975 to 1989 failed to show any definite pattern. However, more red tide events occurred in months with high mixing index values. The absence of definable patterns could be due to the use of monthly, rather than daily, values in the calculations.


Journal Article
TL;DR: There was significant difference in mortality rates among the Malay, Chinese and Indian babies born in this hospital: the Indians had the highest and the Chinese the lowest rates.
Abstract: A 2-year study was carried out in the Maternity Hospital, Kuala Lumpur to determine the neonatal mortality rates. This Hospital functions both as the local service centre as well as the national referral centre in Malaysia. Its neonatal services, however, were equipped and manned at those below Level III perinatal centre. During the study period 52, 877 livebirths took place in the Hospital. In 1987 and 1988 respectively, the low birthweight (less than 2500 gm) rates were: 112.8 and 101.9 per 1000 livebirths, very low birthweight (less than 1500 gm) rates: 11.1 and 8.8 per 1000 livebirths, neonatal mortality rates: 12.5 and 10.7 per 1000 livebirths and neonatal mortality risk ratio: 1.15 and 1.27. There was significant difference in mortality rates among the Malay, Chinese and Indian babies born in this hospital: the Indians had the highest and the Chinese the lowest rates. Babies delivered by breech or lower segment Caesarean section (LSCS) also had significantly higher mortality than those delivered by other modes of delivery. Low birthweight neonates constituted less than 45% of the total special care nursery admission but contributed to more than 70% of the total neonatal deaths. The common causes of neonatal deaths were problems of prematurity, infection, asphyxia and congenital malformations. Preterm and low birthweight neonates died primarily from problems of prematurity or infection. Term and larger neonates died mainly from asphyxia. More than 75% of the neonatal deaths occurred before 7 days of life. Improvement of antenatal care in the community and upgrading of perinatal services in this Hospital could help to lower the morbidity and mortality due to preventable causes.

Journal ArticleDOI
TL;DR: Forty-one compounds have been identified in the essential oil of Ruta angustifolia, including piperonyl acetone and a novel olefinic derivative 8-(3,4-methylenedioxyphenyl)-1-octene.
Abstract: Forty-one compounds have been identified in the essential oil of Ruta angustifolia. Besides the already known compounds, seven derivatives possessing the 3,4-methylenedioxyphenyl moiety were identified, including piperonyl acetone and a novel olefinic derivative 8-(3,4-methylenedioxyphenyl)-1-octene.

Journal Article
TL;DR: When compared with predicted levels for white American and Australian children the predicted levels of PEFR of Malaysian children were found to be lower; these differences could be clinically important and the use of standards for Western children when assessing Malaysian children might not be appropriate.
Abstract: Prediction equations for peak expiratory flow rate (PEFR) of Malay, Chinese and Indian children were obtained by analysing 1020 PEFR recordings of children free of respiratory symptoms and illnesses. Boys had significantly higher PEFR than girls. For both sexes the highest levels of PEFR were observed in Malays and the lowest in Indians. The differences between Malay and Chinese boys were not statistically significant but the levels of PEFR for Malay and Chinese boys were significantly higher than those for Indian boys. In girls the differences among the ethnic groups were not statistically significant. Although ethnic differences were observed in boys these differences might not be clinically important. A common prediction equation for each sex should be both practical and accurate. When compared with predicted levels for white American and Australian children the predicted levels of PEFR of Malaysian children were found to be lower; these differences could be clinically important and the use of standards for Western children when assessing Malaysian children might not be appropriate.

Journal Article
TL;DR: Lambda-cyhalothrin was found to be the most effective pyrethroid when tested against Aedes albopictus adult females and larvae compared with that of deltamethrin and permethrin.
Abstract: Three pyrethroids were evaluated in the laboratory against Aedes albopictus females by exposure to insecticide impregnated papers, and to 4th instar Ae. albopictus larvae as insecticide solutions. Lambda-cyhalothrin was found to be the most effective pyrethroid when tested against Aedes albopictus adult females and larvae compared with that of deltamethrin and permethrin.

Journal ArticleDOI
TL;DR: The results indicate that exotoxin is produced in vivo during infection by P. pseudomallei in sheep sera exposed to natural infection.

Journal ArticleDOI
TL;DR: The results show that at most sampling stations, particularly those within the Seremban municipality, the level of phenols was found to exceed the recommended Malaysian standard of 2.0 μg/L-1 for raw water, which indicates the unhealthy state of the Linggi river.
Abstract: Phenolic chemicals with their very low taste and odour thresholds, high persistence and toxicity, are of growing concern as water pollutants. The compounds are known to exist in raw water as well as in treated water. The level of phenolic priority pollutants in water within the catchment area of the Linggi River Treatment Plant in Negeri Sembilan, Malaysia, which includes the Linggi river basin, was monitored. The 4-aminoantipyrin colourimetric method was used to determine total phenols whereas capillary column gas chromatography was used to determine the individual compounds. The results show that at most sampling stations, particularly those within the Seremban municipality, the level of phenols was found to exceed the recommended Malaysian standard of 2.0 µg/L-1 for raw water. This is seen as the direct impact of industrial and urbanization of the area and clearly indicates the unhealthy state of the Linggi river. The results also indicate the need to improve the water quality if the river is going to be used as a source of raw water.

Journal Article
TL;DR: Sodium citrate was found to increase the gastric pH significantly in both Group II and III patients when compared with Group I patients who underwent emergency caesarean section, and tends to be associated with an increase in gastric volume.
Abstract: The effectiveness of sodium citrate as a prophylaxis against acid aspiration syndrome was studied in 3 groups of obstetric patients. Group I was the control group which consisted of 20 patients in established labour who were not likely to require caesarean section. No antacid had been given to these patients. Group II consisted of 20 patients who underwent elective caesarean section, while Group III consisted of another 20 patients who underwent emergency caesarean section. Group II and III were given 30ml of 0.3M sodium citrate as soon as they arrived in the operation theatre. The gastric content was aspirated after the induction of anaesthesia and at the end of surgery just before extubation. The volume was measured and a sample sent for pH analysis. Sodium citrate was found to increase the gastric pH significantly in both Group II and III patients when compared with Group I patients who underwent emergency caesarean section. We conclude that 30ml of 0.3M sodium citrate is effective in increasing gastric pH though it tends to be associated with an increase in gastric volume.

Journal ArticleDOI
TL;DR: A random survey of 400 doctors was carried out over a period of 3 months to determine the factors that would facilitate or inhibit the participation of doctors in continuing medical education (CME) in Malaysia.
Abstract: Summary. A random survey of 400 doctors was carried out over a period of 3 months to determine the factors that would facilitate or inhibit the participation of doctors in continuing medical education (CME) in Malaysia. Regular participation in CME was defined as participation in any activity (self-directed reading or attending organized activities) at least once a month during the past year. It was found that 78% of doctors regularly participated in CME. Working in a hospital environment and being members of the Malaysian Medical Association and at least one specialty organization appeared to be important facilitatory factors in CME participation. These doctors also read the local medical journals regularly and subscribed to other journals. In addition, they were more likely to possess postgraduate qualifications and would have teaching, research, diagnostic or clinical responsibilities as major components of their work. They were more likely to practise in the big cities and would tend to be active in at least one voluntary or social organization. If they were in the Government sector, they were more likely to work in the Universities or in the Hospital Division of the Ministry of Health. The 22% who were less likely to participate in CME were general practitioners in the private sector. They worked long hours with day, evening and/or night shifts every day. If the doctors were in the Government sector, they were more likely to be in the Health Division, working in administration and public health, or they were in the armed forces and other organizations such as local councils. They worked in the smaller towns or in the districts. They were not likely to possess any postgraduate qualification. They did not read local journals regularly nor did they subscribe to other journals. They were members of the Malaysian Medical Association only or belonged to no professional organization. They were unlikely to be actively involved in voluntary non-professional organizations.