In this paper a study on the wideband double-pass Raman fibre amplifier with mirror as the pump reflector is reported. The pump lights at 1435 nm and 1455 nm were launched in a co-directional manner with respect to the input signal. The double-pass direction of the signal was achieved through a fibre loop mirror constructed using an optical circulator. It was shown that multiple signal amplification was achieved without any disturbance of stimulated Brillouin scattering.
A four-stage erbium-doped fibre amplifier with the gain bandwidth of 35 nm is demonstrated. The amplifier was designed to include a dispersion compensating module to compensate the accumulated dispersion by signals. The amplifier design permited some dynamic features such as the amplifier’s gain could be adjusted from 15 dB to 30 dB by varying the input signal power from –26 dBm to 8 dBm. The maximum output power of 23 dBm was obtained with a maximum allowable gain flatness of 1.5 dB.
A distributed feedback fibre laser made of highly Er-Yb co-doped phosphate glass fibre was demonstrated experimentally. The 45 mm long fibre laser device operated at 1540 nm with more than 50 dB side mode suppression ratio. However, the output power was still relatively lower due to un-optimized grating structure and thermal management.
An optical code generating device for a portable optical access-card system was constructed using the plastic optical fibre (POF) waveguide coupler. The newly constructed device provided output light intensities which were used as optical codes in a portable optical access-card system. The construction of a basic 1 × 2 waveguide design combined two major components which were the asymmetric Y-junction splitter and the linear taper. A hollow waveguide structure was utilized as it provided more flexibility in guiding light rays. A basic 1 × 2 waveguide coupler was designed using the CAD tool and then the ray was traced using the non-sequential ray tracing tool. A linear relationship between the tap-off ratio and the waveguide tap-width enabled a higher-level hollow waveguide coupler to be designed using the simple cascading technique. Construction of a 1 × 4 and higher level waveguide coupler was easily realized using the basic 1 × 2 waveguide coupler design together with a simple cascading technique.
The laser technology laboratory (LTL) of the Physics Department, University of Technology Malaysia was established in 1989 to support research and development activities. The laboratory provides activities for short- and long-term projects to serve final year undergraduate and post-graduate students in masters and PhD programmes.
MeSH terms: Laboratories; Malaysia; Physics; Research; Students
In this paper, the tuning range characteristics of a multiwavelength L-band Brillouin-erbium fibre laser utilizing a linear cavity is described. The dependency of the Stokes signal tuning range on the laser’s pumping power and single mode fibre length is elaborated. The proposed laser configuration exhibited a wide tuning range of 11 nm from 1599 nm to 1610 nm. The maximum number of 28 output channels with a spacing of 10.5 GHz was achieved by setting the Brillouin pump wavelength and power at 1603.1 nm and 1.1 mW, respectively. The wider tuning range and higher number of Brillouin Stokes contributed to the higher efficiency of doublepass amplification in the erbium gain medium and also to the bidirectional generation of Brillouin Stokes in the single-mode fibre.
The operating principle and the performance of chromatic dispersion (CD) measurement technique are discussed through developed numerical models. The performance of the CD measurement technique was studied in terms of the measurement range and sensitivity as the wavelength separation was varied. Based on the numerical model, the technique sensitivity increased with wavelength separation. However, this increase in sensitivity was traded off with a narrower measurement range. The measurement technique was optimized at 5.0 GHz wavelength separation with a sensitivity of 0.009 (dB/ps/nm) and measurement range of 2500 ps/nm.
A descriptive study was conducted to evaluate the prevalence of Blastocystis hominis in children aged between 1-12 years old from randomly selected villages in Alor Gajah district Melaka. The sampling was carried out from 1st to 7th of July of 2006. A total of 48 faecal samples were obtained from the children in those studied villages. The faecal specimens were examined by direct saline wet moun, formalin ethyl acetate concentration and trichrome staining method. It was found that 45.8% (22 out of 48) of the examined children were infected with Blastocystis hominis . Based on the results, the cumulative prevalence of three methods used showed that Blastocystis hominis infection in female children higher compared to male children. Whilst the schooling children aged of 6 to 12 years had a higher prevalence than pre school children at the age of 1-5 years. In term of diagnosis, formalin ethyl acetate concentration method showed prevalence of detection at 60.9%. It was followed by direct saline wet mount (43.5%) and trichrome staining at 34.8%.
MeSH terms: Acetates; Child; Feces; Female; Formaldehyde; Humans; Male; Sodium Chloride; Staining and Labeling; Prevalence; Blastocystis Infections; Blastocystis hominis
This study was aimed at identifying the effectiveness of hospital-based pulmonary rehabilitation programme as compared to home-based pulmonary programme in improving the condition of the chronic obstructive pulmonary disease (COPD) patients of Universiti Kebangsaan Malaysia Hospital. A total of 35 patients aging between 17 to 78 years old were randomised either to hospital (48.6%, n = 20) or home (43%, n = 15) -based pulmonary rehabilitation by the Physiotherapists. For the hospital-based rehabilitation programme, the patients were scheduled to come to the hospital twice a week for eight weeks. For home-based rehabilitation programme, subjects were scheduled to come to the Physiotherapy Department twice to learn on the exercises that need to be carried out before they are allowed to do on their own at home. Each subject was given a diary to record the exercises that have been done. A telephone call is made once a week for monitoring purpose. Assessment of lung function, six-minute-walk test and Borg score were carried out before and after the eight-week rehabilitation is conducted. The Results showed that there was no significant change in lung function for both groups before and after rehabilitation. There is a significant different (p < 0.05) in 6MWT before and after rehabilitation for hospital-based pulmonary rehabilitation patients. However, the difference is not significant (p > 0.05) for home-base pulmonary rehabilitation patients. The results also show that there exist no significant correlation between lung function and 6MWT even though there is an increase in walking distance at baseline or the eighth week. In conclusion, hospitalbased pulmonary rehabilitation is more effective than the home-based pulmonary rehabilitation in improving the exercise endurance which would helps in reduce dyspnoea among COPD patients.
Keywords: Home-based pulmonary programme; Hospital-based pulmonary programme; COPD; Lung function
A preliminary study was conducted to determine the level of oxidative DNA damage, fruits and vegetables intake among 50 breast cancer patients (cases) as compared to 50 healthy women (controls) with no known medical history of breast cancer in Klang Valley. Both groups were matched for age and ethnicity. Data on socio-demographic, health status and medical history, fruits and vegetables intake, and supplements intake were obtained through an interviewbased questionnaire. Anthropometry measurements included weight, height, and waist and hip circumference were also carried out on subjects. A total of 3mL fasting venous blood was drawn to assess lymphocytes oxidative DNA damage using Alkaline Comet Assay. Results indicated that the mean intake of fruits and vegetables was lower in cases (4.09 ± 1.17 servings/d) than controls (4.77 ± 0.90 servings/d)(p < 0.05) The intake of fruits and vegetables from family groups of solanaceae, myrtaceae, caricaceae, apiaceae, brinjal, rutaceae, broccoli, orange, carrot, watermelon were 0.5 - 1 servings/week significantly higher among controls as compared to cases (p < 0.05 for all parameters). However, the intake of fruits from rosaceae family and apple was higher among controls than cases (p < 0.05). The estimated intake of ß-carotene, carotenoids, vitamin A, vitamin C (p < 0.001), a-carotene and lycopene (p < 0.05) from fruits and vegetables were higher among controls than cases. Mean DNA damage level of cases (4.55 ± 1.78 % DNA in tail, %TD; 0.35 ± 0.21 tail moment, TM) were 3.5 and 3.9 times higher than the value of controls (1.3 ± 0.70% TD; 0.09 ± 0.09 TM) (p < 0.001) and the damage increased with higher values of waist hip ratio (% TD, r = 0.396, p < 0.05; TM, r = 0.349, p < 0.05) and waist circumference (% TD, r = 0.334, p < 0.05; TM, r = 0.360, p < 0.05). There was an inverse relationship between oxidative DNA damage with intake of total fruits and vegetables, cauliflowers and water convolvulus and also consumption from rutaceae and solanaceae families. Similar trend was noted for estimated intake of vitamin A, carotenoids, vitamin C, ß-carotene and lycopene. In conclusion, the intake of fruits and vegetables of five servings/d and the consumption of specific families and types of fruits and vegetables might protect against oxidative DNA damage and further reduce breast cancer risk.
A functional magnetic resonance imaging (fMRI) study was conducted on 4 healthy male and female subjects to investigate brain activation during passive and active listening. Two different experimental conditions were separately used in this study. The first condition requires the subjects to listen to a simple arithmetic instruction (e.g. one-plus-two-plus-three-plus-four) - passive listening. In the second condition, the subjects were given the same series of arithmetic instruction and were required to listen and perform the calculation - active listening. The data were then analysed using the Statistical Parametric Mapping (SPM5) and the MATLAB 7.4 (R2007a) programming softwares. The results obtained from the fixed (FFX) and random effects analyses (RFX) show that the active-state signal intensity was significantly higher (p < 0.05) than the resting-state signal intensity for both conditions. The results also indicate significant differences (p < 0.001) in brain activation between passive and active listening. The activated cortical regions during passive listening, as obtained from the FFX of the first condition is symmetrical in the left and right temporal and frontal lobes covering the cortical auditory areas. However, for the second condition, which was active listening, more activation occurs in the left hemisphere with a reduction in the number of activated voxels and their signal intensity in the right hemisphere. Activation mainly occurs in the middle temporal gyrus, precentral gyrus, middle frontal gyrus, superior temporal gyrus and several other areas in the frontal lobes. The point of maximum signal intensity has been shifted to a new coordinates during active listening. It is also observed that the magnetic resonance signal intensity and the number of activated voxel in the right and left superior temporal lobes for the second condition have been reduced as compared to that of the first condition. The results obtained strongly suggest the existence of functional specialisation. The results also indicate different networks for the two conditions. These networks clearly pertain to the existence of functional connectivity between activation areas during listening and listening while performing a simple arithmetic task.
MeSH terms: Auditory Cortex; Auditory Perception; Female; Frontal Lobe; Magnetic Resonance Imaging; Male; Magnetic Resonance Spectroscopy; Software; Temporal Lobe
Low-molecular-weight heparins (LMWHs) are antithrombotic agents utilised in the treatment of acute coronary syndromes. They have been shown to be more effective than unfractionated heparins (UFHs) in reducing ischeamic events, which include death, myocardial infarction (MI) and urgent revascularisation. Enoxaparin is one of the products of LMWHs. Its safety and efficacy has been proven in the ESSENCE and TIMI IIB studies. This study was carried out to identify risk factors that may affect bleeding complications associated with the use of enoxaparin for non-ST-elevation MI (NSTEMI) or unstable angina (UA) in Universiti Kebangsaan Malaysia Hospital (HUKM). This observational, longitudinal study was conducted on patients who were admitted to the Coronary Care Unit (CCU), Coronary Rehabilitation Ward (CRW), Medical 1 and Medical 2 wards at HUKM and initiated on enoxaparin for NSTEMI/UA from 22nd of March until 22nd of April 2004. A total of 40 patients were included in the study with median age of 65 years, male to female ratio of 3:1, diagnosed with NSTEMI (55%) and UA (45%). 45% of patients developed an episode of bleeding and among them 83.3% (15 patients) characterised by haematuria. Higher percentages of women (80%) and those with creatinine clearance of < 30ml/min (100%) had incidence of bleeding as compared to men (50%) and those with creatinine clearance = 30 ml/min, respectively (p < 0.05 for both parameters). Age, enoxaparin dose and duration of therapy, smoking and concomitant aspirin/ticlopidine therapy did not significantly affect the incidence of bleeding. In conclusion, renal impairment and gender were associated with bleeding in relation with the use of enoxaparin that may require dose adjustments.
The accumulation of tear film proteins as well as microbes colonization onto worn contact lenses can be eliminated conventionally by mechanical rubbing during the cleaning process. Lens2® functions in rotation manner to loosen the deposits on the contact lens and has antimicrobial coating to keep lenses away from contamination. The objective of this study was to determine the efficiency of Lens2® to remove deposited protein and reduce microbial contamination compared to conventional method. Twenty-eight subjects each wore a pair of contact lens FDA Group 1 (Polymacon, SoftLens® 38, Bausch & Lomb) for one month and cleaned them using multipurpose solution (COMPLETE® MoisturePLUSTM, Advanced Medical Optics) separately using two different methods. The right lens was cleaned conventionally while the left lens were cleaned using the Lens2®. The control group of thirteen subjects each wore a pair of contact lens for the same period and cleaned both conventionally. These lenses and its cases were then analyzed for protein deposition using Bichinchoninic Acid Assay (BCA) Kit (Sigma, USA) in 96-well plate. Microbial contamination was determined by culturing the samples on nutrient agar for bacteria and fungi and non-nutrient agar for amoeba isolation. The mean of total protein on control lenses (17.014 ± 13.246 µg/mL) was not significantly different from those on the Lens2® (21.623 ± 19.127 µg/mL). There were also low growth numbers of amoeba in each group of samples. Interestingly, there were no growths of amoeba from all Lens2® samples collected. There was also low growth numbers of bacteria in each sample group whereby Lens2® had the lowest growth of bacteria. No growth of fungi was obtained from all samples. The automatic lens cleaner, Lens2® was found to be as efficient as the conventional cleaning method. However, the Lens2® has additional advantage because of its antimicrobial material and need shorter time in the cleaning process as well as easy and effective.
MeSH terms: Agar; Amoeba; Anti-Infective Agents; Bacteria; Contact Lenses; Eye Proteins; Fungi; Polyhydroxyethyl Methacrylate; Rotation; Pharmaceutical Solutions; Hydrogels; Control Groups
White and whole meal breads have been classified as high glycemic index (GI) foods which in turn produce the greatest rise in blood glucose. One of the commercial bread products in Malaysia known as Brown breads (BB) has been recently marketed as a healthy choice for diabetics due to its low GI value. This study was conducted to examine the effect of BB when eaten with different fillings on blood glucose response among healthy individuals and to describe the influences of these fillings in reducing blood glucose response. Five test meals using BB (BB eaten with baked beans, BB eaten with vegetable, BB eaten with apple, BB eaten with roast chicken and BB eaten with seaweeds) had been prepared for this study. Postprandial blood glucose response was determined for each test meal and reference food (glucose) that contained 50 g carbohydrate respectively. A total of 21 healthy subjects were recruited by advertisement to participate. Only 20 subjects (15 males, 5 females, Mean + SD Age : 24.4 + 3.7 years; BMI 23.4 + 3.0 kgm-2) completed this study. After an overnight fast, subjects consumed BB eaten with fillings according to the assigned group given and three repeated tests of reference food (glucose). Fasting capillary blood glucose samples were taken at time 0 and at 15, 30, 45, 60, 90 and 120 min respectively after the meal began. The blood glucose response was obtained by calculating the incremental area under the curve (AUC). Blood glucose response after consuming reference food (251.8 + 12.1 mmol.min/L) was significantly higher than all the test meals (p < 0.05). Among the test meals, BB eaten with baked beans produced the highest rise in blood glucose (97.0 + 16.9 mmol.min/L) whereas BB eaten with seaweeds demonstrated the lowest response in blood glucose (33.3 + 6.5 mmol.min/L) and the difference was statistically significant (p < 0.05). The postprandial blood glucose response after ingestion of BB when eaten with vegetable was 73.3 + 19.1 mmol.min/L followed by BB eaten with apple (58.9 + 12.2 mmol.min/L) and BB eaten with roast chicken (56.5 + 10.1 mmol.min/L). Generally, BB when eaten with fillings produced a slow rise in blood glucose response than the reference food. Combining this BB with fillings had the effect of reducing the postprandial blood glucose further.
MeSH terms: Animals; Blood Glucose; Bread; Chickens; Diabetes Mellitus; Eating; Fasting; Female; Glucose; Humans; Hypoglycemia; Malaysia; Male; Seaweed; Vegetables; Body Mass Index; Postprandial Period; Area Under Curve; Malus; Glycemic Index; Meals; Healthy Volunteers
This study was carried out in Agricultural Park, Teluk Cempedak and Bukit Pelindung at Kuantan, Pahang in October 2007. These three areas were different in ecological characteristic, Agricultural Park is a lowland region in Kuantan rural area, Teluk Cempedak is Kuantan’s most famous beach, and Bukit Pelindung is a reserved rainforest which is 200 meters from the sea level. Fly specimens were collected using four different kinds of baits: dry prawn, salted fish, pork and mango. Each of these baits was placed in a plastic container and exposed for one hour to attract flies. Within 5 minutes, flies started swarming around the baits. The flies were more attracted to the pork and salted fish compared to the other two baits. Fifty one flies, one moth (Lepidoptera) and one wasp (Hymenoptera) were collected. In Agricultural Park, two Lucilia cuprina, one Chrysomya megacephala and one Sarcophaga sp. were collected. For Teluk Cempedak beach, there were two Sarcophagids, 31 Chrysomya megacephala, five Musca domestica, one Lucilia cuprina and one moth were caught. Flies collected from Bukit Pelindung included five C.megacephala, two Sarcophagids, one Musca domestica and one wasp. Most C.megacephala were attracted to the pork and salted fish.
Food frequency questionnaire (FFQ) is a practical tool for the measurement of usual food intake in large surveys because it gives a quick approximation to 'true' dietary intake. This study was carried out to compare the semiquantitative FFQ with three day 24-hour diet recalls (24-hr DR) in assessing intake of energy, total fat, fatty acids and vitamin A, C and E among Malaysian women. This semi-quantitative FFQ which was developed specifically for the Malay and Indian ethnicities has 200 food items and categorized according to three mealtimes namely breakfast, lunch or dinner and morning or afternoon snacks. A total of 51 Malay and 28 Indian women aged between 30 to 60 years were selected as study subjects. The result of the study shows that majority of study subjects were within the normal EI/BMR ratio when their energy intake was assessed by semi-quantitative FFQ (70%) and 24-hr DR (74%). However, 10% of study subjects became over-reporters when their intakes were assessed using the semi-quantitative FFQ. Analysis of t-test shows there is no significant difference (p > 0.05) on the mean intake of energy, total fats, saturated, monounsaturated and polyunsaturated fatty acids and vitamin A, C and E between semi-quantitative FFQ and 24-hr DR. Percent mean differences were also less than 10% for all nutrients included in this study. This indicates that the semi-quantitative FFQ can produce comparable results with 24-hr DR. Energy adjusted correlation coefficient values for all studied nutrients were total fat (r = 0.64, p = 0.02), saturated fatty acids (r = 0.59, p = 0.01), monounsaturated fatty acids (r = 0.52, p = 0.03), polyunsaturated fatty acids (r = 0.57, p = 0.02), vitamin A (r = 0.69, p = 0.01), retinol (r = 0.55, p = 0.01), beta carotene (r = 0.74, p = 0.01), vitamin C (r = 0.64, p = 0.02) and vitamin E (r = 0.69, p = 0.01). Cross-classification for both methods into quartiles of intake resulted in correct classification into the same or adjacent quartile from 82% to 96% of the study subjects. Only 3% of the subjects were grossly misclassified. As a conclusion, this semi-quantitative FFQ gives estimation as good as 24-hr DR for intakes of energy, total fat, fatty acids and vitamin A, C and E among Malaysian women specifically for the Malay and Indian ethnicities. This semi-quantitative FFQ is a useful tool in dietary intake assessment for research use especially for epidemiological study on diet and disease relationship such as cardiovascular, cancer and diabetes.
The abdominal pelvic cavity has always been regarded as one of the most vulnerable regions of the body. Injuries to this part have been known to be very serious. Based on this a retrospective study was performed on postmortem cases with abdominal and pelvic trauma from 1 October 2002 to 31 January 2003 at the Forensic Institute, Hospital Kuala Lumpur to determine the common pattern of abdomino-pelvic injuries, the injury’s relationship to epidemiological and socio-economic factors, risk organ within the abdominopelvic region and relationship between injuries and survival period. A total of 122 cases abdomino-pelvic were obtained stemming from medico legal postmortems procedures. Results indicated that those aged between 21 to 30 years (38.5%) had the highest incidence of this type of injury. Categorization based on gender showed that males (90.2%) dominated most of the cases. Prevalence based on socio-economic status showed that lower socioeconomy class (52.5%) had the highest incident. This was followed by the middle income (39.3%) and finally the higher income group. The most numerous type of trauma was non-penetrating trauma (94.3%). It was also found that victims with low injury severity score (ISS) had a longer survival period as compared to those with high ISS. It was also noted that victims with two or more region injuries either were spot dead or brought dead. The most common combination of injuries was abdomen, pelvic, chest and limb. In most blunt trauma cases majority of victims had one or two organ involvement while penetrating injuries were difficult to asses. The most common organ involved in this type of trauma was liver (72.1%), pelvic bone (47.5%) and spleen (43.4%). In conclusion, abdomino-pelvic injury is a serious condition and should not be overlooked. Proper attention towards their diagnosis and management is important and so any patient of head injury with coma must be considered as having intra-abdominal injury until proven otherwise.
When medical and surgical intervention cannot alleviate all of the impairments resulting from diseases of the eye, visual rehabilitation can help reduce the disability and increase the quality of life. Data from 169 patients seen at the UKM Low Vision Clinic (UKM LVC) over the past 2 years were examined and analysed. The age ranged from 6 to 87 years of age. The main cause of ocular pathological categories was conduction (63.9%), media (24.9%) and congenital (11.2%) related problems. The main causes of low vision at UKM LVC were congenital cataract, retinitis pigmentosa, glaucoma, cataract and diabetic retinopathy. 84% of these patients received low vision devices to improve their near or/and distance vision. The most common optical devices dispensed at UKM LVC were near high addition spectacle, hand magnifiers and stand magnifiers. Medical, vision care and rehabilitation professionals working together can offer a comprehensive treatment plan for the visually impaired, offering these patients the very best services to increase their quality of life.
This paper reports the nutrition knowledge of Malaysian elderly, as part of a nationwide study to evaluate the status of nutrition knowledge, attitude and practice (KAP) of food and nutrition among various communities in Malaysia. A total of 906 elderly, age ranging between 60 to 96 years old, with mean age 67.4 ± 6.7 years representing all states in Malaysia participated in the study. An interview administered questionnaire was used to assess the nutrition knowledge and to collect demographic data of the elderly. Subjects were in the 60-65 years (51%) and more than 65 years (49%) age category. There were 46% Malays, 32% Chinese, 6% Indians while the remaining 16% comprised of other minority groups in Malaysia such as Iban, Kadazan, Melanau, Orang Asli and others. More than half of the elderly (54%) had no formal education, 36% completed primary schooling and only 9% finished secondary education. Overall 73% elderly were categorized as having poor nutrition knowledge, 18% moderate and only 9% good. The minority groups had the highest percentage of poor nutrition knowledge (91%) while the Chinese had the highest percentage of good nutrition knowledge (11%). More female (78%) than male (67%) had poor nutrition knowledge, in contrast to more male (10%) than female (8%) with good nutrition knowledge. Chi square test showed that there was a significant correlation between educational status and nutrition knowledge. This was reflected in the results which showed that 81% elderly with no formal education were categorized in the poor nutrition knowledge group. Majority of the elderly did not know about foods to be consumed most (88%), or to be eaten least (87%). Only a quarter to a third of the elderly responded correctly to questions on nutrient function and content. The question on foods with high salt was well responded by the elderly (65%). It is quite discouraging to show that a majority of Malaysian elderly had poor nutrition knowledge. This study indicated that appropriate nutrition education interventions need to be implemented to improve the shortcomings of nutrition knowledge among the Malaysian elderly.
The anatomical structures of the first, second and third instars of Chrysomya rufifacies (Macquart) were examined by light microscopy. Observations were documented on the three main characteristics; the cephalopharyngeal skeleton, anterior spiracle and posterior spiracle. The first instar larva bore cornuae of fairly pigmented delineation with slim hypostomal sclerite and distinct dental sclerite. First instar did not have obscured anterior spiracle but posterior spiracles were obscured with thin lining of opened peritreme. Intersegmental spines were evident. The second instar larva displayed a prominent anterodorsal process approaching closer to hypostomal sclerite while upper margin of the dorsal cornua was slightly pigmented. Each anterior spiracle consisted of nine to ten papillae, arranged in a single row. Peritreme of the posterior spiracle thick, opening at the end of peritreme was not wide and confined to two spiracular slits. The third instar larva showed a prominent arch of the ventral cornua with broad and bold appearance. It approached the dorsal cornua and became narrow at the incision median. The anterior spiracle consisted of a single row of nine to ten papillae while intersegmental spine could be identified with one to three dark pigmented tips. A dark pigmented and wide periterime was observed confining three short and thick spiracular slits while button was poorly pigmented. The most distinctive feature of this second and third instar larva was the slender, thorn-like tubercle with numerous spined tips on the middle line segment of the body. These findings provide identification features of C. rufifacies larvae instars.