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Spatial distributions of (137)Cs and (239+240)Pu in surface seawater within the Exclusive Economic Zone of East Coast Peninsular Malaysia

Ahmad Z, Mei-Wo Y, Abu Bakar AS, Shahar H

Appl Radiat Isot, 2010 Sep;68(9):1839-45.
PMID: 20430636 DOI: 10.1016/j.apradiso.2010.04.012

The studies of (137)Cs and (239+240)Pu distributions in surface seawater at South China Sea within the Exclusive Economic Zone (EEZ) of Peninsular Malaysia were carried out in June 2008. The analysis results will serve as additional information to the expanded baseline data for Malaysia's marine environment. Thirty locations from extended study area were identified in the EEZ from which large volumes of surface seawater samples were collected. Different co-precipitation techniques were employed to concentrate cesium and plutonium separately. A known amount of (134)Cs and (242)Pu tracers were used as yield determinant. The precipitate slurry was collected and oven dried at 60(o)C for 1-2 days. Cesium precipitate was fine-ground and counted using gamma-ray spectrometry system at 661.62keV, while plutonium was separated from other radionuclides using anion exchange, electrodeposited and counted using alpha spectrometry. The activity concentrations of (137)Cs and (239+240)Pu were in the range of 3.40-5.89Bq/m(3) and 2.3-7.9mBq/m(3), respectively. The (239+240)Pu/(137)Cs ratios indicate that there are no new inputs of these radionuclides into the area.
Fulltext Impact of sandwiched strain periodic multilayer AlN/GaN on strain and crystalline quality of a-plane GaN

Kamarundzaman A, Abu Bakar AS, Azman A, Omar AZ, Talik NA, Supangat A, et al.

Sci Rep, 2021 May 06;11(1):9724.
PMID: 33958689 DOI: 10.1038/s41598-021-89201-8

We demonstrated high-quality single crystalline a-plane undoped-gallium nitride grown on a nonpatterned r-plane sapphire substrate via metal-organic chemical vapor deposition. The effect of four different numbers of sandwiched strain-periodic AlN/GaN multilayers on the strain state, crystal quality, optical and electrical properties was investigated. Field emission scanning electron microscopy and atomic force microscopy showed that the surface morphology was improved upon insertion of 120 pairs of AlN/GaN thin layers with a root-mean-square roughness of 2.15 nm. On-axis X-ray ω-scan rocking curves showed enhanced crystalline quality: the full width at half maximum decreased from 1224 to 756 arcsec along the [0001] direction and from 2628 to 1360 arcsec along the [1-100] direction for a-GaN grown with 120 pairs of AlN/GaN compared to a-GaN without AlN/GaN pairs. Reciprocal space mapping showed that a-plane GaN with a high number of AlN/GaN pairs exhibits near-relaxation strain states. Room-temperature photoluminescence spectra showed that the sample with the highest number of AlN/GaN pairs exhibited the lowest-intensity yellow and blue luminescence bands, indicating a reduction in defects and dislocations. The a-plane InGaN/GaN LEDs with 120 pairs of SSPM-L AlN/GaN exhibited a significant increase (~ 250%) in light output power compared to that of LEDs without SSPM-L AlN/GaN pairs.
Fulltext Author Correction: Impact of sandwiched strain periodic multilayer AlN/GaN on strain and crystalline quality of a-plane GaN

Kamarundzaman A, Abu Bakar AS, Azman A, Omar AZ, Talik NA, Supangat A, et al.

Sci Rep, 2021 Aug 11;11(1):16639.
PMID: 34381162 DOI: 10.1038/s41598-021-96016-0
A study on level of physical activity, depression, anxiety and stress symptoms among adolescents

Tajik E, Abd Latiff L, Adznam SN, Awang H, Yit Siew C, Abu Bakar AS

J Sports Med Phys Fitness, 2017 Oct;57(10):1382-1387.
PMID: 28004901 DOI: 10.23736/S0022-4707.16.06658-5

BACKGROUND: Inadequate physical activity has adverse health consequences among adolescents. Mental health problem can be developed by lack of physical activity however it is controversial. The current study aimed to examine the association between level of physical activity with depression, anxiety and stress symptoms among adolescents.
METHODS: A representative sample of 1747 adolescents (13-14 years) was randomly selected from 6 schools in a south part of Malaysia. Respondents were asked to fill consent form, and questionnaires including Depression Anxiety and Stress Scale-21 and Physical Activity Questionnaire for Adolescents.
RESULTS: Majority of respondents (71.9%) was Malay and more than half of the adolescents had low physical activity. About 40% had depression symptoms, followed by anxiety symptoms (65.9%) and stress symptoms (38.5%). Level of physical activity was significantly associated with gender, anxiety and stress (P<0.001). There were no associations with race, religion and depression symptom.
CONCLUSIONS: This study provides some evidence among school-going adolescents related to anxiety and stress symptoms and low physical activities. Further studies are needed to show the protection effects of higher physical activity for depression, anxiety and stress symptoms in adolescents.
Fulltext Connective tissue growth factor: Role in trabecular meshwork remodeling and intraocular pressure lowering

Hassan MDS, Razali N, Abu Bakar AS, Abu Hanipah NF, Agarwal R

Exp Biol Med (Maywood), 2023 Aug;248(16):1425-1436.
PMID: 37873757 DOI: 10.1177/15353702231199466

Connective tissue growth factor (CTGF) is a distinct signaling molecule modulating many physiological and pathophysiological processes. This protein is upregulated in numerous fibrotic diseases that involve extracellular matrix (ECM) remodeling. It mediates the downstream effects of transforming growth factor beta (TGF-β) and is regulated via TGF-β SMAD-dependent and SMAD-independent signaling routes. Targeting CTGF instead of its upstream regulator TGF-β avoids the consequences of interfering with the pleotropic effects of TGF-β. Both CTGF and its upstream mediator, TGF-β, have been linked with the pathophysiology of glaucomatous optic neuropathy due to their involvement in the regulation of ECM homeostasis. The excessive expression of these growth factors is associated with glaucoma pathogenesis via elevation of the intraocular pressure (IOP), the most important risk factor for glaucoma. The raised in the IOP is due to dysregulation of ECM turnover resulting in excessive ECM deposition at the site of aqueous humor outflow. It is therefore believed that CTGF could be a potential therapeutic target in glaucoma therapy. This review highlights the CTGF biology and structure, its regulation and signaling, its association with the pathophysiology of glaucoma, and its potential role as a therapeutic target in glaucoma management.
Fulltext Susceptibility of Aedes albopictus, Ae. aegypti and human populations to Ross River virus in Kuala Lumpur, Malaysia

Fu JYL, Chua CL, Abu Bakar AS, Vythilingam I, Wan Sulaiman WY, Alphey L, et al.

PLoS Negl Trop Dis, 2023 Jun;17(6):e0011423.
PMID: 37307291 DOI: 10.1371/journal.pntd.0011423

BACKGROUND: Emerging arboviruses such as chikungunya and Zika viruses have unexpectedly caused widespread outbreaks in tropical and subtropical regions recently. Ross River virus (RRV) is endemic in Australia and has epidemic potential. In Malaysia, Aedes mosquitoes are abundant and drive dengue and chikungunya outbreaks. We assessed risk of an RRV outbreak in Kuala Lumpur, Malaysia by determining vector competence of local Aedes mosquitoes and local seroprevalence as a proxy of human population susceptibility.
METHODOLOGY/PRINCIPAL FINDINGS: We assessed oral susceptibility of Malaysian Ae. aegypti and Ae. albopictus by real-time PCR to an Australian RRV strain SW2089. Replication kinetics in midgut, head and saliva were determined at 3 and 10 days post-infection (dpi). With a 3 log10 PFU/ml blood meal, infection rate was higher in Ae. albopictus (60%) than Ae. aegypti (15%; p<0.05). Despite similar infection rates at 5 and 7 log10 PFU/ml blood meals, Ae. albopictus had significantly higher viral loads and required a significantly lower median oral infectious dose (2.7 log10 PFU/ml) than Ae. aegypti (4.2 log10 PFU/ml). Ae. albopictus showed higher vector competence, with higher viral loads in heads and saliva, and higher transmission rate (RRV present in saliva) of 100% at 10 dpi, than Ae. aegypti (41%). Ae. aegypti demonstrated greater barriers at either midgut escape or salivary gland infection, and salivary gland escape. We then assessed seropositivity against RRV among 240 Kuala Lumpur inpatients using plaque reduction neutralization, and found a low rate of 0.8%.
CONCLUSIONS/SIGNIFICANCE: Both Ae. aegypti and Ae. albopictus are susceptible to RRV, but Ae. albopictus displays greater vector competence. Extensive travel links with Australia, abundant Aedes vectors, and low population immunity places Kuala Lumpur, Malaysia at risk of an imported RRV outbreak. Surveillance and increased diagnostic awareness and capacity are imperative to prevent establishment of new arboviruses in Malaysia.
Fulltext Sexual dysfunction in patients with polycystic ovary syndrome in Malaysia

Dashti S, Latiff LA, Hamid HA, Sani SM, Akhtari-Zavare M, Abu Bakar AS, et al.

Asian Pac J Cancer Prev, 2016;17(8):3747-51.
PMID: 27644611

BACKGROUND: Polycystic ovary syndrome (PCOS) is a combination of chronic anovulation, obesity, and hyperandrogenism and can affect sexual function in women of reproductive age. It is also associated with endometrial cancer. Our aim was to evaluate the frequency and predisposing factors of sexual dysfunction in PCOS patients.

MATERIALS AND METHODS: In this cross-sectional study, 16 married women with a definite diagnosis of PCOS were recruited. Sexual function was assessed in the domains of desire, arousal, lubrication, orgasm, satisfaction and pain using the female sexual function index (FSFI) questionnaire. Patients were also assessed for mental health using the depression, anxiety and stress (DASS-21) questionnaire. Presence of hirsutism was assessed using the Ferriman-Gallwey (FG) scoring system. Demographic data were obtained from patients during in-person interview.

RESULTS: Sexual dysfunction was present in 62.5% of patients with the domains of arousal and lubrication particularly affected (93.8% and 87.5%, respectively). Patients with symptoms of depression and anxiety were significantly more likely to suffer sexual dysfunction than those without these symptoms (p=0.04 and p=0.03 respectively). Patients with stress symptoms reported higher orgasm dysfunction than those without (p=0.02). No significant difference in any of the FSFI score domains was observed between patients with and without hirsutism.

CONCLUSIONS: PCOS patients markedly suffer from sexual dysfunction and therefore it seems appropriate to be screened for intervention. Poor mental health conditions that may be the result of infertility or other complications of PCOS should also be considered as curable causes of sexual dysfunction in these patients.
Fulltext A review on the assessment of the efficacy of common treatments in polycystic ovarian syndrome on prevention of diabetes mellitus

Dashti S, Latiff LA, Zulkefli NABM, Baharom AB, Minhat HS, Hamid HA, et al.

J Family Reprod Health, 2017 Jun;11(2):56-66.
PMID: 29282412

Objective: Polycystic ovarian syndrome (PCOS) is a common condition amongst women of reproductive age that can result in increased mortality and morbidity in women due to increased risk of diabetes mellitus and cardiovascular diseases. The aim of this systematic review was to assess the effectiveness of common treatments of PCOS on the predictors of diabetes in non-diabetic PCOS women. Materials and methods: An extensive search was performed on the publications in three medical databases including pubmed, scopus and google scholar from 1995 till 2017. The articles were screened based on their quality and included in this systematic review. A total of 25 articles including cohort, randomised controlled trial, review and meta-analysis were included in the review. Results: This systematic review revealed that the effect of lifestyle modification might be low in PCOS subjects due to high drop-out rate while the benefits of this intervention including weight and fat reduction may not be achieved by medical interventions. Metformin treatment may result in improvements in insulin sensitivity while its weight reduction effect is still not documented in PCOS subjects. Thiazolidendiones might be tolerated by the PCOS subjects and may result in similar effects as metformin but this effect should be documented by further studies. Conclusion: Combination of lifestyle modification with metformin or thiazolidinedions might improve the outcome of the prevention strategies. On the other hand this study revealed a different response to treatments in non-obese compared with obese PCOS subjects.