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Fulltext Mechanical and Morphological Properties of Bio-Phenolic/Epoxy Polymer Blends

Ismail AS, Jawaid M, Hamid NH, Yahaya R, Hassan A

Molecules, 2021 Feb 03;26(4).
PMID: 33546097 DOI: 10.3390/molecules26040773

Polymer blends is a well-established and suitable method to produced new polymeric materials as compared to synthesis of a new polymer. The combination of two different types of polymers will produce a new and unique material, which has the attribute of both polymers. The aim of this work is to analyze mechanical and morphological properties of bio-phenolic/epoxy polymer blends to find the best formulation for future study. Bio-phenolic/epoxy polymer blends were fabricated using the hand lay-up method at different loading of bio-phenolic (5 wt%, 10 wt%, 15 wt%, 20 wt%, and 25 wt%) in the epoxy matrix whereas neat bio-phenolic and epoxy samples were also fabricated for comparison. Results indicated that mechanical properties were improved for bio-phenolic/epoxy polymer blends compared to neat epoxy and phenolic. In addition, there is no sign of phase separation in polymer blends. The highest tensile, flexural, and impact strength was shown by P-20(biophenolic-20 wt% and Epoxy-80 wt%) whereas P-25 (biophenolic-25 wt% and Epoxy-75 wt%) has the highest tensile and flexural modulus. Based on the finding, it is concluded that P-20 shows better overall mechanical properties among the polymer blends. Based on this finding, the bio-phenolic/epoxy blend with 20 wt% will be used for further study on flax-reinforced bio-phenolic/epoxy polymer blends.
Fulltext Child and adolescent mental health service, Terengganu, Malaysia: how we are thinking about making a difference

Dahlan R, Abd Ghani MN, Yahaya R, Tuan Hadi TS

London J Prim Care (Abingdon), 2018;10(4):118-120.
PMID: 30083246 DOI: 10.1080/17571472.2018.1484333
Fulltext Bridging exhibitionism and internet pornography: is there a link?

Lee SC, Sidi H, Zakaria H, Loo JL, Yahaya R

Malaysian Journal of Medicine and Health Sciences, 2018;14(3):51-53.
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Exhibitionism is a distressing condition which may have a link with the increasing availability and usage of online sexual activities (OSA). We highlight a 42-year-old man who presented with a constant craving for OSA to achieve his sexual satisfaction which included exposing his genitalia to virtual partners, unsuspected strangers, and colleagues in public areas. His sexual behaviours were further reinforced by an online video chatting with genitalia exposure, which ended commonly with an exchange of masturbatory acts. He denied any problem with his erection and able to achieve orgasm via common sexual acts. There was no past psychiatric history nor family history of mental disorder. He volunteered to seek psychiatric help and subsequently given a psycho education on his illness and how to cope with the distress associated with his sexual acts. He was scheduled for an intensive psychotherapy to instil insight and hope to deal with his sexual difficulties.
Fulltext Child and Adolescent Mental Health Service (CAMHS), Terengganu, Malaysia: milestones so far and the paths to the future

Dahlan R, Abd Ghani MN, Yahaya R, Tuan Hadi TS

London J Prim Care (Abingdon), 2018;10(4):113-117.
PMID: 30083245 DOI: 10.1080/17571472.2018.1484318

This study aims to provide an overview of mental health problems of children and adolescents in Malaysia in general and the state of Terengganu in particular. It also highlights the challenges and the opportunities in the establishment of child and adolescent mental health services (CAMHS). CAMHS in Malaysia are developing slowly but have not reached the standards found in developed countries. Significant improvements are needed to ensure that the service can provide optimal help to children and adolescent as well as their families. Constraining factors such as a lack of trained workers, limited financial resources for training and inadequate facilities are among the challenges. Despite all these challenges, specific strategies are required to optimally utilise the potential existing resources. The Ministry of Health initiatives in creating and implementing the national mental health policy and increasing mental health awareness campaigns for children and adolescents are of paramount importance. To overcome the lack of resources in the implementation of CAMH services, in-service education and training, integration of mental health services with the existing primary health care facilities and cultivation of cooperative and communicative networks between primary care professionals, mental health workers and other relevant agencies are crucial steps.
Verification of MCNP simulation of neutron flux parameters at TRIGA MK II reactor of Malaysia

Yavar AR, Khalafi H, Kasesaz Y, Sarmani S, Yahaya R, Wood AK, et al.

Appl Radiat Isot, 2012 Oct;70(10):2488-93.
PMID: 22885391 DOI: 10.1016/j.apradiso.2012.06.015

A 3-D model for 1 MW TRIGA Mark II research reactor was simulated. Neutron flux parameters were calculated using MCNP-4C code and were compared with experimental results obtained by k(0)-INAA and absolute method. The average values of φ(th),φ(epi), and φ(fast) by MCNP code were (2.19±0.03)×10(12) cm(-2)s(-1), (1.26±0.02)×10(11) cm(-2)s(-1) and (3.33±0.02)×10(10) cm(-2)s(-1), respectively. These average values were consistent with the experimental results obtained by k(0)-INAA. The findings show a good agreement between MCNP code results and experimental results.
Fulltext Enhanced Thermal and Dynamic Mechanical Properties of Synthetic/Natural Hybrid Composites with Graphene Nanoplateletes

Jesuarockiam N, Jawaid M, Zainudin ES, Thariq Hameed Sultan M, Yahaya R

Polymers (Basel), 2019 Jun 26;11(7).
PMID: 31247898 DOI: 10.3390/polym11071085

The aim of the present research work is to enhance the thermal and dynamic mechanical properties of Kevlar/Cocos nucifera sheath (CS)/epoxy composites with graphene nano platelets (GNP). Laminates were fabricated through the hand lay-up method followed by hot pressing. GNP at different wt.% (0.25, 0.5, and 0.75) were incorporated with epoxy resin through ultra-sonication. Kevlar/CS composites with different weight ratios (100/0, 75/25, 50/50, 25/75, 0/100) were fabricated while maintaining a fiber/matrix weight ratio at 45/55. Thermal degradation and viscoelastic properties were evaluated using thermogravimetric analysys (TGA), differential scanning calorimetric (DSC) analysis, and a dynamic mechanical analyser (DMA). The obtained results revealed that Kevlar/CS (25/75) hybrid composites at 0.75 wt.% of GNP exhibited similar thermal stability compared to Kevlar/epoxy (100/0) composites at 0 wt.% of GNP. It has been corroborated with DSC observation that GNP act as a thermal barrier. However, DMA results showed that the Kevlar/CS (50/50) hybrid composites at 0.75 wt.% of GNP exhibited almost equal viscoelastic properties compared to Kevlar/epoxy (100/0) composites at 0 wt.% GNP due to effective crosslinking, which improves the stress transfer rate. Hence, this research proved that Kevlar can be efficiently (50%) replaced with CS at an optimal GNP loading for structural applications.
Fulltext Improved Mechanical and Moisture-Resistant Properties of Woven Hybrid Epoxy Composites by Graphene Nanoplatelets (GNP)

Naveen J, Jawaid M, Zainudin ES, Thariq Hameed Sultan M, Yahaya R

Materials (Basel), 2019 Apr 16;12(8).
PMID: 30988270 DOI: 10.3390/ma12081249

This research investigated the effect of adding different wt.% (0, 0.25, 0.50, and 0.75) of GNP (graphene nanoplatelets) to improve the mechanical and moisture resistant properties of Kevlar (K)/cocos nucifera sheath (CS)/epoxy hybrid composites. The laminates were fabricated with different K/CS weight ratios such as 100/0 (S1), 75/25 (S2), 50/50 (S3), 25/75 (S4), and 0/100 (S5). The results revealed that the addition of GNP improved the tensile, flexural, and impact properties of laminated composites. However, the optimal wt.% of GNP varies with different laminates. A moisture diffusion analysis showed that the laminates with a 0.25 wt.% of GNP content efficiently hindered water uptake by closing all the unoccupied pores inside the laminate. Morphological investigations (SEM and FE-SEM (Field Emission Scanning Electron Microscope)) proved that the addition of GNP improved the interfacial adhesion and dispersion. Structural (XRD and FTIR) analyses reveals that at 0.25 wt.% of GNP, all the hybrid composites showed a better crystallinity index and the functional groups presents in the GNP can form strong interactions with the fibers and matrix. A statistical analysis was performed using One-way ANOVA, and it corroborates that the mechanical properties of different laminates showed a statistically significant difference. Hence, these GNP-modified epoxy hybrid composites can be efficiently utilized in load-bearing structures.
Fulltext Brain-derived neurotrophic factor (BDNF) in schizophrenia research: a quantitative review and future directions

Ahmad R, Azman KF, Yahaya R, Shafin N, Omar N, Ahmad AH, et al.

AIMS Neurosci, 2023;10(1):5-32.
PMID: 37077958 DOI: 10.3934/Neuroscience.2023002

This review aims to perform a bibliometric analysis of the research related to brain-derived neurotrophic factor (BDNF) in schizophrenia and offer suggestions for further work. Based on the keywords used, our study retrieved 335 documents for further analysis using a combination of three bibliometric techniques: co-word analysis, document co-citation analysis, and bibliographic coupling. A general rising trend in the number of publications was found in BDNF and schizophrenia research. Researchers from China and the United States have mostly researched BDNF and schizophrenia. Molecular Psychiatry is the most prestigious journal in the field of BDNF and schizophrenia research. The main topics and important research areas are cognition and the involvement of BDNF as a neurobiological marker (pathogenesis, therapy monitoring, and risk factors). Future research is anticipated to concentrate on relevant subjects, such as factors that affect BDNF levels or are connected to BDNF dysfunction in schizophrenia, as well as animal models of schizophrenia, in addition to cognition in schizophrenia.
Serum adiponectin and resistin: Correlation with metabolic syndrome and its associated criteria among temiar subtribe in Malaysia

Zahary MN, Harun NS, Yahaya R, Nik Him NAS, Rohin MAK, Ridzwan NH, et al.

Diabetes Metab Syndr, 2019 04 25;13(3):2015-2019.
PMID: 31235129 DOI: 10.1016/j.dsx.2019.04.048

BACKGROUND AND OBJECTIVES: Metabolic syndrome (MetS) is characterized as a cluster of metabolic disorder including increased blood pressure, elevated blood glucose level, high cholesterol level and visceral fat obesity. Polypeptide hormones such as adiponectin and resistin play a significant role in glucose and lipids metabolism, liver and pancreas function. This study aimed to investigate the relationship between serum adiponectin and resistin with MetS criteria among Temiar subtribe in Kuala Betis.
MATERIALS AND METHODS: This cross sectional study involved 123 subjects from Temiar subtribe in Kuala Betis, Gua Musang, Kelantan. MetS criteria were measured according to standard protocol by modified National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) guideline. Anthropometric and biochemical measurements were performed including serum adiponectin and resistin for every study subjects.
RESULTS: Serum adiponectin was significantly lower in MetS subjects (7.98 ± 5.65 ng/ml) but serum resistin was found to be significantly higher in MetS subjects (11.22 ± 6.34 ng/ml) compared to non-MetS subjects with p 
Fulltext Tualang honey supplementation as cognitive enhancer in patients with schizophrenia

Yahaya R, Zahary MN, Othman Z, Ismail R, Nik Him NAS, Abd Aziz A, et al.

Heliyon, 2020 May;6(5):e03948.
PMID: 32426546 DOI: 10.1016/j.heliyon.2020.e03948

Introduction: Schizophrenia is a chronic mental illness with clusters of symptoms, including cognitive impairment. This study aimed to explore the effect of Tualang Honey (TH) on cognitive domains, especially as it pertained to the verbal memory of schizophrenia patients.
Method: This was a cross-sectional study involved 80 individuals, diagnosed with schizophrenia. The Malay Version Auditory Verbal Learning Test (MVAVLT) was used. Data were analysed using SPSS 20.0 software. Intention to treat analysis was applied.
Result: A comparison of the total learning score at eight weeks between the two groups based on time effect and time-treatment interaction favoured TH group.
Conclusion: This study concludes that by supplementing schizophrenia patients with 8-week of TH did improve total learning performance across domains in the immediate memory among patients with schizophrenia.