Optically stimulated Al2O3:C luminescence dosimeters for teletherapy: Hp(10) performance evaluation.

The performance of optically stimulated luminescence dosimeters (OSLDs, Al2O3:C) was evaluated in terms of the operational quantity of HP(10) in Co-60 external beam teletherapy unit. The reproducibility, signal depletion, and dose linearity of each dosimeter was investigated. For ten repeated readouts, each dosimeter exposed to 50mSv was found to be reproducible below 1.9 ± 3% from the mean value, indicating good reader stability. Meanwhile, an average signal reduction of 0.5% per readout was found. The dose response revealed a good linearity within the dose range of 5-50mSv having nearly perfect regression line with R2 equals 0.9992. The accuracy of the measured doses were evaluated in terms of operational quantity HP(10), wherein the trumpet curve method was used respecting the 1990 International Commission on Radiological Protection (ICRP) standard. The accuracy of the overall measurements from all dosimeters was discerned to be within the trumpet curve and devoid of outlier. It is established that the achieved OSL Al2O3:C dosimeters are greatly reliable for equivalent dose assessment.

Effect of co-doping of sodium on the thermoluminescence dosimetry properties of copper-doped zinc lithium borate glass system.

The effect of sodium as a co-dopant on the thermoluminescence (TL) properties of copper-doped zinc lithium borate (ZLB: Cu) subjected to Co-60 gamma radiation is reported in this study. TL intensity is enhanced with the introduction of sodium in ZLB: Cu. The obtained glow curve is simple with a single peak. The annealing procedure and the best heating rate for the proposed thermoluminescent dosimeter (TLD) are established, and the phosphor is reusable. The TL response within the dose range of 0.5-1000Gy is investigated. The results show that the thermal fading behaviour is improved significantly.

Thermoluminescence dosimetry properties and kinetic parameters of lithium potassium borate glass co-doped with titanium and magnesium oxides.

Lithium potassium borate (LKB) glasses co-doped with TiO2 and MgO were prepared using the melt quenching technique. The glasses were cut into transparent chips and exposed to gamma rays of (60)Co to study their thermoluminescence (TL) properties. The TL glow curve of the Ti-doped material featured a single prominent peak at 230 °C. Additional incorporation of MgO as a co-activator enhanced the TL intensity threefold. LKB:Ti,Mg is a low-Z material (Z(eff)=8.89) with slow signal fading. Its radiation sensitivity is 12 times lower that the sensitivity of TLD-100. The dose response is linear at doses up to 10(3) Gy. The trap parameters, such as the kinetics order, activation energy, and frequency factor, which are related to the glow peak, were determined using TolAnal software.

Risk factors for suicidal ideation, plans and attempts in Malaysia--results of an epidemiological survey.

OBJECTIVE: This is an epidemiological study to determine the prevalence of suicidal behavior and its association with generalised anxiety disorder (GAD) and major depressive disorder (MDD) in a nationally representative sample. METHOD: Suicidal ideation, plans and attempts were assessed in face-to-face interviews of respondents selected by a multistage probability sampling using items on suicidality from the WHO SUPRE-MISS questionnaire. The Mini International Neuropsychiatric Interview (MINI) was used to generate DSM-IV diagnoses of GAD and MDD. A total of 19309 subjects were studied. Multivariate regression analysis was conducted controlling for demographic characteristics such as age, gender and ethnicity. RESULTS: The prevalence estimates for suicide ideation, plans and attempts were 1.7% (95% CI: 1.4-1.9), 0.9% (CI: 0.7-1.1) and 0.5% (CI: 0.4-0.7) respectively. Younger people (16-24 years) had higher risk of suicidal behavior (OR: 2.6, CI: 1.08-6.2). Females (OR: 1.6, CI: 1.2-2.1) and Indians (OR: 3.3, CI: 2.2-4.9) also had higher risk. CONCLUSION: The prevalence of suicidal behavior in Malaysia is low, but it broadly corresponds to the pattern described in other countries. This national study confirms that Malaysians of Indian descent have much higher rates of suicidal behavior than other groups. The younger age group, females and the Indian ethnic group would need focused preventive efforts.

Suicide prevention program for at-risk groups: pointers from an epidemiological study.

OBJECTIVES: The aim of this paper is to identify at-risk groups for a focused suicide prevention program for Malaysia. METHODS: Data from 20,552 persons aged 16 years and above (males 45.9%), was obtained using stratified, random sampling in a national survey of psychiatric morbidity using locally validated General Health Questionnaire (GHQ-28) which included questions on suicidal ideation. RESULTS: The overall prevalence of suicidal ideation (SI) was 6.3%, CI 6.1-6.8 (n=1288). Logistic regression analysis was performed with age, ethnicity, gender, urban/rural residence, age group, marital status, household income, type of household, presence of chronic pain, social dysfunction, somatic, anxiety or depressive symptoms, obesity, and chronic medical illnesses as independent variables. Only Insomnia, Religion, Marital Status, Depression, Social Dysfunction and Anxiety were seen to be significant predictors. Prevalence of SI was significantly higher among Indians (11.0%, CI 9.5-12.5), especially those of the Hindu faith (12.2%, CI 10.5-14.0), Chinese (9.7%, CI 8.8-10.7) and those having depressive symptoms. CONCLUSION: In a developing country with competing priorities, prudent allocation of resources requires focusing suicide prevention efforts on treating depression in vulnerable groups.

The National Mental Health Registry (NMHR).

The National Mental Health Registry (NMHR) collects information about patients with mental disorder in Malaysia. This information allows us to estimate the incidence of selected mental disorders, and to evaluate risk factors and treatment in the country. The National Mental Health Registry (NMHR) presented its first report in 2004, a year after its establishment. The report focused on schizophrenia as a pioneer project for the National Mental Health Registry. The development of the registry has progressed with data collected from government-based facilities, the academia and the private sector. The 2003-2005 report was recently published and distributed. Since then the registry has progressed to include suicides and other mental illnesses such as depression. The NMHR Report 2003-2005 provides detailed information about the profile of persons with Schizophrenia who presented for the first time to various psychiatry and mental health providers throughout Malaysia. More detailed description regarding pharmacotherapy is reported and few cross tabulations done in an effort to provide better understanding and more clinically meaningful reports.

Prevalence of emotional and behavioural problems in Johor Bahru District school children--comparing three geographical areas.

This is a cross sectional community study in Johor Bahru District. The aim of this study is to estimate the overall prevalence of emotional and behavioural deviance among the school children in three different geographical areas, and to identify their correlates. This paper presents the findings of phase one of a two-stage procedure involving a total of 589 children aged 10-12 years. Using the cut-off point validated locally, the prevalence of deviance on the parental scale was 40% in the rural school, 30.2% in the agricultural resettlement (Felda) school and 32.3% in the urban school. On the teachers' assessment, the prevalence of deviance was 40.8% in the rural school, 10.8% in the Felda School and 8.9% in the urban school. There was significantly higher prevalence of deviance in the rural school on the teachers' scale. In the rural school, significantly higher prevalence of deviance was found among boys.

Audit of new long-stay patients in Permai Mental Hospital, Johor.

We report a cross-sectional descriptive study of 90 new long-stay patients (NLS) (i.e. those who had been resident for six months to three years in Permai Mental Hospital, Johor) and studied from April to June, 1995. The age of this sample ranged from 18 to 85 years. Two subgroups were observed (i.e. younger NLS patients aged 18 to 34 years and older NLS patients aged 35 to 85 years). Among the younger NLS patients, the commonest diagnosis was schizophrenia (51.2%), followed by mental retardation with related problems (24.4%). Sixty-one percent of these younger patients had a history of serious violence or dangerous behaviour. Older NLS patients were likely to have a diagnosis of schizophrenia (79.6%), followed by mood disorder (6.1%) and dementia (4.1%). Forty seven percent of these older group had history of danger to others and 57.1% were at moderate or severe risk of non-deliberate self-harm. Focusing on the schizophrenic patients, all of them had some form of psychopathology, either positive, negative or general symptoms and about one-fourth were assessed to pose a risk for aggression.

Characteristics of psychiatric admissions and aspects of overcrowding at the general Hospital, Kuala Lumpur.

This study examined admissions, final diagnoses and mean duration of stay of patients in the Psychiatric Wards at the General Hospital, Kuala Lumpur. The male ward was severely overcrowded by 125% over the maximum bed capacity. The majority were psychotic, mainly schizophrenic. The female ward had 76% occupancy, also mainly psychotic. Neurotics, alcohol dependents and personality disorders formed less than 5% of the admissions. There was no difference in the mean duration of stay of patients of both UKM and GHKL Units stratified for diagnosis and disposal except for newly diagnosed schizophrenics. There is an urgent need for more male psychiatric beds/wards.