Tunable passively Q-switched thulium-fluoride fiber laser in the S+/S band (1450.0 to 1512.0 nm) region using a single-walled carbon-nanotube-based saturable absorber.

A tunable passively Q-switched for S+/S band thulium-fluoride fiber (TFF) laser using single-walled carbon nanotubes as a saturable absorber is proposed and demonstrated. The tunability of the proposed laser covers a wavelength region of 1450.0-1512.0 nm, with a range of 62.0 nm. Stable Q-switched operation can be obtained at a pump power of 115.7-229.9 mW at 1492.0 nm. The resulting pulses have a measured repetition rate and pulse width of 12.0-36.4 kHz and 6.2-3.6 µs, respectively. The maximum pulse energy that was achieved in this experiment is 122.8 nJ. To the author's knowledge, this is the first reported tunable passively Q-switched TFF laser that covers the S+/S region that has been demonstrated.

Knowledge, attitude and perception of second-hand smoke and factors promoting smoking in Malaysian adolescents.

OBJECTIVE: To identify the relationship between knowledge, attitude and perception regarding environmental tobacco smoke (ETS) and smoking among Malaysian adolescents living in states with complete or partial smoke-free legislation (SFL). METHODS: A total of 898 respondents aged 13-14 years were randomly selected from 21 secondary schools. The Malay version of the modified Global Youth Tobacco Survey questionnaire was used. Hierarchical logistic regression was performed in examining predictors of smoking attempt among adolescents. RESULTS: Participants exposed to ETS >5 h/day were more likely to have smoked compared to those exposed to ETS <1 h/day (OR 4.1, 95%CI 1.03-16.0). Living in a state with partial SFL was associated with a two-fold increase in self-reported smoking attempts (OR 1.95, 95%CI 1.10-3.43) compared to living in a state with complete SFL. Negative attitudes and perceptions towards smoking and ETS exposure were linked to lower smoking attempts in states with complete SFL. CONCLUSIONS: Adolescents with limited ETS exposure who lived in a state with complete SFL were less likely to attempt smoking compared to those exposed more regularly to ETS and living in a state with partial SFL. Preventing adolescents from becoming smokers is the key to reducing national prevalence rates in smoking. There is a need to implement comprehensive smoke-free legislation nationally across Malaysia.

Ultrasonographic findings in eyes with retinopathy of prematurity in malaysia.

RetCam is an excellent screening tool for the detection of retinopathy of prematurity (ROP). However, affordability is a barrier when adopting the use of RetCam in developing countries. We aimed to describe different stages of ROP using ultrasonographic B-scan and to evaluate the association between funduscopic examinations and ultrasonographic B-scan findings in premature neonates with ROP in Malaysia. A descriptive cross sectional study was conducted in 90 eyes of 47 premature neonates with different stages of ROP in three tertiary hospitals in Malaysia. Experienced ophthalmologists performed detailed funduscopic examinations using binocular indirect ophthalmoscopy (BIO). A masked examiner performed a 10 MHz ultrasonographic B-scan evaluation with 12 meridian position images within 48 hours of clinical diagnosis. Data from the clinical examination and ultrasonographic findings were collected and analysed. We recruited 37 eyes (41.1%) with stage 1 ROP, 29 eyes (32.3%) with stage 2, 18 eyes (20.0%) with stage 3, and 3 eyes (3.3%) with stages 4 and 5 based on the clinical assessment. Ultrasonography correctly identified 3 (8.1%) stage 1 eyes, 17 (58.6%) stage 2 eyes, 13 (72.2%) stage 3 eyes, and 3 each (100%) of the stage 4 and 5 eyes. There was a significant association between the funduscopic signs and the ultrasound findings for stage 2 ROP and above (Fisher's exact test, p <0.001). In conclusion, all stages of ROP were detected and described with a 10 MHz ultrasonic B-scan system. A significant association was observed between funduscopic signs and ultrasonographic findings in premature Malaysian neonates with stage 2 ROP and above.

Prediction error and accuracy of intraocular lens power calculation in pediatric patient comparing SRK II and Pediatric IOL Calculator.

BACKGROUND: Despite growing number of intraocular lens power calculation formulas, there is no evidence that these formulas have good predictive accuracy in pediatric, whose eyes are still undergoing rapid growth and refractive changes. This study is intended to compare the prediction error and the accuracy of predictability of intraocular lens power calculation in pediatric patients at 3 month post cataract surgery with primary implantation of an intraocular lens using SRK II versus Pediatric IOL Calculator for pediatric intraocular lens calculation. Pediatric IOL Calculator is a modification of SRK II using Holladay algorithm. This program attempts to predict the refraction of a pseudophakic child as he grows, using a Holladay algorithm model. This model is based on refraction measurements of pediatric aphakic eyes. Pediatric IOL Calculator uses computer software for intraocular lens calculation. METHODS: This comparative study consists of 31 eyes (24 patients) that successfully underwent cataract surgery and intraocular lens implantations. All patients were 12 years old and below (range: 4 months to 12 years old). Patients were randomized into 2 groups; SRK II group and Pediatric IOL Calculator group using envelope technique sampling procedure. Intraocular lens power calculations were made using either SRK II or Pediatric IOL Calculator for pediatric intraocular lens calculation based on the printed technique selected for every patient. Thirteen patients were assigned for SRK II group and another 11 patients for Pediatric IOL Calculator group. For SRK II group, the predicted postoperative refraction is based on the patient's axial length and is aimed for emmetropic at the time of surgery. However for Pediatric IOL Calculator group, the predicted postoperative refraction is aimed for emmetropic spherical equivalent at age 2 years old. The postoperative refractive outcome was taken as the spherical equivalent of the refraction at 3 month postoperative follow-up. The data were analysed to compare the mean prediction error and the accuracy of predictability of intraocular lens power calculation between SRK II and Pediatric IOL Calculator. RESULTS: There were 16 eyes in SRK II group and 15 eyes in Pediatric IOL Calculator group. The mean prediction error in the SRK II group was 1.03 D (SD, 0.69 D) while in Pediatric IOL Calculator group was 1.14 D (SD, 1.19 D). The SRK II group showed lower prediction error of 0.11 D compared to Pediatric IOL Calculator group, but this was not statistically significant (p = 0.74). There were 3 eyes (18.75%) in SRK II group achieved accurate predictability where the refraction postoperatively was within ± 0.5 D from predicted refraction compared to 7 eyes (46.67%) in the Pediatric IOL Calculator group. However the difference of the accuracy of predictability of postoperative refraction between the two formulas was also not statistically significant (p = 0.097). CONCLUSIONS: The prediction error and the accuracy of predictability of postoperative refraction in pediatric cataract surgery are comparable between SRK II and Pediatric IOL Calculator. The existence of the Pediatric IOL Calculator provides an alternative to the ophthalmologist for intraocular lens calculation in pediatric patients. Relatively small sample size and unequal distribution of patients especially the younger children (less than 3 years) with a short time follow-up (3 months), considering spherical equivalent only.

The WHO dose pole for the administration of praziquantel is also accurate in non-African populations.

In 2001, WHO developed a pole for the administration of praziquantel without the use of weighing scales, with encouraging results in African populations. In the present study, the pole was tested on height/weight data from 9354 individuals from 11 non-African countries. In more than 98% of the individuals (95% CI 97.8-98.4) the pole estimated an acceptable dosage (30-60 mg/kg), a performance statistically similar to that observed in African populations. Reproducing the present pole in the form of a strip of paper and including it in each container of praziquantel would greatly facilitate the administration of the drug in large-scale interventions.

The timing and stability of choice of medical specialty among Malaysian doctors.

A total of 356 doctors responded to a survey on the timing and stability of choice of medical specialty. The majority of doctors made their final decision while working as a medical officer. One hundred (48.5%) of the doctors had made an earlier choice as medical students, 63 (30.6%) during their internship and 43 (20.9%) made their final choice while they were medical officers. Working experience in the specialty was the most important factor in determining final choice of specialty. Advice from consultants/seniors, better financial prospects and parental influence were more important for the male doctors while marriage and family considerations were more important for the female doctors in making their final choice.

The prevalence of malnutrition and geo-helminth infections among primary schoolchildren in rural Kelantan.

A cross-sectional study of the nutritional status of schoolchildren aged 7-10 years from the Kuala Betis Resettlement Scheme in Gua Musang, Kelantan was done. A total of 291 schoolchildren were examined but only 183 (62.9%) fecal samples were returned for geo-helminth infection analysis. The prevalence of stunting was 40.4% and underweight was 28.4%. A total of 127 schoolchildren (69.4%) were positive for at least one of the 3 geo-helminth infections. The most common geo-helminth was Ascaris lumbricoides (62.8%), followed by Trichuris trichiura (38.9%), and hookworm infection was relatively low (12.6%). All the anthropometric indices measured were lower in the geo-helminth infected children compared to the uninfected childen, except for the weight-for-height z-score. However the differences were insignificant Geo-helminth infections may not be a significant factor in malnutrition of these schoolchildren. However, with the availability of safe, efficacious and cheap broad spectrum anthelmintics, regular mass treatment should be given in selected areas where the prevalence of geo-helminth infections is still high, so that these schoolchildren will be able to achieve their growth potential during their school years.

The nutritional status of children in resettlement villages in Kelantan.

A cross-sectional survey of the nutritional status of children aged 1-10 years old from the Kuala Betis resettlement villages was carried out. A total of 620 children were examined, of which 329 were preschool children and 291 were schoolchildren. The age was determined and anthropometric measurements such as weight, height and MUAC were taken. The nutritional status was assessed by looking at the distributions of the z-scores of weight-for-age (WAZ), height-for-age (HAZ) and weight-for-height (WHZ) in relation to the growth charts of the National Center for Health Statistics reference population. It was found that the nutritional status of the Orang Asli children was poor, with a prevalence of 33.7-65.3% underweight, 55.3-74.4% stunting and 4.4-29.7% wasting based on the NCHS reference values. The prevalence of malnutrition among the Malay children was lower, underweight--7.3-34.1%, stunting--9.8-34.1% and wasting--1.7-17.1%. The nutritional status of the Orang Asli children were poorer compared to the Malay children. More preschool Orang Asli children were stunted compared to the Orang Asli schoolchildren. This may be due to the poor economic base of the Orang Asli community during the transformation period after resettlement. A comprehensive primary health care program is essential, especially targeting the preschool Orang Asli children in these resettlement villages.

The prevalence and intensity of soil-transmitted helminthiasis among pre-school children in Orang Asli resettlement villages in Kelantan.

A study of the prevalence and intensity of soil-transmitted helminthiasis among pre-school children aged 0 to 7 years from an Orang Asli village resettlement scheme in Gua Musang, Kelantan was undertaken. The overall prevalence of soil transmitted helminthic (STH) infections was 56.0%. The predominant helminth found was Ascaris lumbricoides while the commonest type of infection was a mixed infection with Ascaris lumbricoides and Trichuris trichiura. The prevalence rates of Ascaris, Trichuris and hookworm infections were 47.5%, 33.9% and 6.2% respectively. The intensity of Ascaris infections were 64.5% light, 27.3% moderate and 8.3% heavy whilst the intensity of Trichuris infections were 80.5% light, 18.3% moderate and 1.2% heavy. However, the intensity of hookworm infections were 86.7% light, 13.3% moderate and no heavy infection. The prevalence of helminthiasis (STH) shows an-age dependent relationship, with the lowest prevalence in 0-< 1 year age group and highest in the 6-< 7 year age group.

Specialty choices of male and female doctors in Malaysia.

A survey of specialisation choices was conducted for two batches of medical officers applying to the local medical schools for specialisation in Malaysia. A total of 359 doctors responded, giving a response rate of 71%, with 169 male (44.4%) and 187 female (55.6%) respondents. Surgery ranked highest among the male doctors followed by orthopaedic surgery and internal medicine. Family medicine ranked highest among female doctors followed by public health and anaesthesiology. Among the other specialties, the male doctors preferred otorhinolaryngology while female doctors preferred Pathology. Both male and female doctors chose to be a clinical consultant in a general hospital as the first choice. They prefer to work in or near their hometowns.

Career preferences of male and female medical students in Malaysia.

A survey of career choices were conducted for three batches of final year medical students at Universiti Sains Malaysia. A total of 241 students responded, giving a response rate of 76%, with 107 males (44.4%) and 134 females (55.6%). Surgery ranked highest among the male students while obstetrics and gynaecology ranked highest among female students. Internal medicine was the second choice for both males and females. Among the other specialties, the male students shows preferred Hospital Administration and Radiology while female students preferred Community Medicine, Psychiatry and Pathology. Both male and female students chose to be a clinical consultant in a general hospital as the first choice. They prefer to work in or near their hometowns.

Health status of senior civil servants in Kuala Lumpur.

733 senior civil servants comprising 520 males and 213 females with a mean age of 44 years (range 25-56 years) were screened for their health status. The sample population comprised of 67.9% Malays, 22.5% Chinese, 9.1% Indians and 0.4% other ethnic origins. The subjects' medical histories were recorded and a full medical examination including anthropometric measurements (weight, height, waist and hip circumference), blood biochemistry and urine analysis, chest X-ray and electrocardiograms were done. The results obtained showed that 36.0% of the study population were overweight with 6.5% being obese. Of this 32.0% had central obesity. 15.2% of the subjects had systolic hypertension (systolic BP > or = 140 mmHg) whilst 27.6% had diastolic hypertension (diastolic BP > or = 90 mmHg). Hyperlipidaemia was common, with 75.2% subjects having raised cholesterol, 19.9% raised triglycerides, 50.2% raised LDL-C, 74.6% raised TC:HDL-C and 26.6% raised LDL:HDL-C. An elevated blood glucose was found in 8.4% subjects, whilst urine sugar was detected in only 2.6%, and a raised uric acid was found in 2.8% subjects. The prevalence of hypertension, raised blood glucose and hyperlipidaemia increased with age with more males affected than females. Although hypercholesterolaemia appeared more frequently amongst the Malays, the Indians, by comparison had the highest prevalence for a raised LDL:HDL-C ratio, a reflection of the increase in LDL-C and a concomitant decrease in HDL-C. The latter findings indicate that the Indians are at greater risk for the development of coronary heart disease than the Chinese and Malays. In addition, the mean levels of serum cholesterol found in this study seemed to have exceeded the levels found in populations in the industrialised countries such as the USA. There is thus an urgent need for more public health campaigns aimed at the reduction and control of such coronary risk factors.

Risk profile of pregnant mothers in Kelantan.

A demographic and obstetric profile of pregnant mothers attending antenatal clinics in kelantan over period of one year was determined by a retrospective study of 10,032 registered pregnant mothers. The prevalence of risk factors related to the age of the mother, parity, weight, haemoglobin level, bad obstetric history and pregnancy related diseases were determined. Prevalence of teenage pregnancy and primigravida accounted for 4.3 and 17.2 percent respectively. Nearly 3.9 percent of the mothers weighed less than 40 kg and 44.5 percent of mothers were found to be anaemic (Hb less than 11g/d) at the first antenatal visit. Only 3.2 percent of the mothers did not have any designated risk factor. Previous bad obstetric history and pregnancy related disease accounted for 17.1 and 3.5 percent of mothers respectively.

A study of the fasting diabetic patients during the month of Ramadan.

Twenty two Muslim diabetic patients on oral hypoglycaemic agents were studied during the fasting month of Ramadan to determine the effect of fasting on their diabetic control. All the patients completed their fast during the month. Their mean (+/- standard deviation) blood glucose, serum fructosamine and body weight before the fasting month were 10.7 +/- 4.6 mmol/l, 6.64 +/- 3.64 mmol/l and 60.5 +/- 12.6 kg and by the end of the fasting month were 10.9 +/- 4.4 mmol/1,4.34 +/- 1.08 mmol/l and 59.8 +/- 12.3 kg respectively. There was no significant difference between the blood glucose levels but there were significant reductions in the mean body weight and fructosamine values (p = 0.01 and p = 0.03 respectively). The mean decrease in body weight and fructosamine were 0.7 +/- 1.3 kg and 2.29 +/- 3.09 mmol/l respectively. There were also statistically significant differences between the mean daily calorie content before the fasting and during the fasting month (1480 +/- 326 vs 1193 +/- 378 Cal/day - p less than 0.005) and between the mean daily carbohydrate content (389 +/- 298 vs 187 +/- 46 gm/day - p less than 0.005). In conclusion, fasting was safe for diabetic patients on oral hypoglycaemic agents and it was associated with weight reduction and improvement in the overall diabetic control. This was most likely due to decrease in food intake.