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Fulltext A Review of Circularly Polarized Dielectric Resonator Antennas: Recent Developments and Applications

Abd Rahman NA, Mohd Yasin MN, Ibrahim IM, Jusoh M, Noor SK, Ekscalin Emalda Mary MR, et al.

Micromachines (Basel), 2022 Dec 08;13(12).
PMID: 36557477 DOI: 10.3390/mi13122178

A comprehensive review on recent developments and applications of circularly polarized (CP) dielectric resonator antennas (DRAs) is proposed in this paper. DRAs have received more considerations in various applications due to their advantages such as wide bandwidth, high gain, high efficiency, low losses, and low profile. A broad justification for circular polarization and DRAs is stated at the beginning of the review. Various techniques such as single feed, dual, or multiple feeds used by different researchers for generating circular polarization in DRAs are briefly studied in this paper. Multiple-input-multiple-output (MIMO) CP DRAs, which can increase channel capacity, link reliability, and data rate, have also been analyzed. Additionally, innovative design solutions for broadening the circular polarization bandwidth and reducing mutual coupling are studied. Several applications of DRA are also discussed comprehensively. This paper finishes with concluding remarks.
Fulltext Relationship between serum methadone concentration and cold pressor pain sensitivity in patients undergoing methadone maintenance therapy

Zahari Z, Lee CS, Ibrahim MA, Musa N, Mohd Yasin MA, Lee YY, et al.

Iran J Pharm Res, 2018;17(Suppl):8-16.
PMID: 29796025

Hyperalgesia is a common clinical phenomenon among opioid dependent patients on methadone maintenance therapy (MMT) and it may be associated with undertreated pain and/or therapeutic failure. This study aimed to investigate association between serum methadone concentration (SMC) and cold pressor pain responses. Cold pressor pain responses in 147 opioid dependent patients on MMT were assessed using cold pressor test (CPT) at 0 h and at 2, 4, 8, 12, and 24 h after the dose intake. Blood samples were collected at 24 h after the dose. Serum methadone concentrations were measured using the Methadone ELISA kit and classified into two categories: < 400 ng/mL and ≥ 400 ng/mL. Eighty-eight patients (59.9%) had trough concentrations of < 400 ng/mL and 40.1% had trough concentrations of ≥ 400 ng/mL. There were significant effects of SMC on the cold pressor pain threshold (p = 0.019). Patients with concentrations < 400 ng/mL had significantly higher (almost 60% higher) cold pressor pain threshold (adjusted mean (95% CI) = 30.15 (24.29, 36.01) s) compared to those with concentrations of ≥ 400 ng/mL (18.93 (11.77, 26.08) seconds). There was also a 20% difference in pain tolerance, and 6% difference in cold pressor pain intensity score, neither of which were significant statistically (p > 0.05). Our results suggest an association of trough methadone concentration with the cold pressor pain threshold among opioid dependent patients on MMT. It would be useful to study the mechanisms underlying this association to help managing pain in such a population.
Study site: Psychiatric Clinic, Hospital Universiti Sains Malaysia (HUSM); Psychiatric Clinic, Hospital Raja Perempuan Zainab II; and eight other government MMT clinics in Kelantan, Malaysia
POPULATION GENETICS OF LONGTAIL TUNA (Thunnus tonggol) (BLEEKER, 1851) FROM EAST MALAYSIA BASED ON MITOCHONDRIAL DNA D-LOOP MARKER

NURUL AZLIANA MOHD YASIN, NOORHANI SYAHIDA KASIM, TUN NURUL AIMI MAT JAAFAR, RUMEAIDA MAT PIAH, WAHIDAH MOHD ARSHAAD, SITI AZIZAH MOHD NOR, et al.

UMT Journal of Undergraduate Research, 2020;2(2):49-56.
MyJurnal

Present study investigates the genetic diversity and genetic distribution of the longtail tuna Thunnus tonggol collected from east Malaysia (Borneo states of Sabah and Sarawak) based on mitochondrial DNA D-loop sequence analysis. 58 fish samples were obtained, specifically from Kota Kinabalu, KK (n = 22), Miri, MR (n=20) and Bintulu, BT (n = 17). DNA template was isolated using the salt extraction method. Final length of 404 base pair (bp) D-loop sequences revealed 52 haplotypes that comprise of 77 variable sites (38 of parsimony informative and 39 singleton). A total of 20 haplotypes were found in KK, 19 haplotypes in MR and 16 haplotypes in BT. Molecular diversity indices revealed high haplotype diversity and low nucleotide diversity in all populations; KK (h = 0.9913 ± 0.0165, π = 0.00239 ± 0.0127), MR (h = 0.9942 ± 0.0193, π = 0.0226 ± 0.0121) and BT (h = 0.9926 ± 0.0230, π = 0.0196 ± 0.0171). Population comparison pairwise FST show that KK and BT were significantly genetically differentiated. The result from this study will be beneficial for fisheries management and also to provide information on the population genetics of T. tonggol in East Malaysian waters.
Fulltext Global energy security and North America: a review

Muhammad Adil Khattak, Nurul Syahrizzat Mohd Yasin, Hannah Natasha Andjani, Puteri Nurailah Husna Mohd Tajuddin, Sakeshraj Narajah, See, Zhi Fei, et al.

Journal of Advanced Research in Applied Sciences and Engineering Technology, 2018;11(1):82-98.
MyJurnal

Geopolitical risks will less affect the oil supply in the United States due to its stability
and widespread oil sectors since 1970s. Nevertheless, energy prosperity in the United
States appears differently in relation to a fuller period for conventional energy export
states where geopolitical challenges have been intensified by monetary pressure and
escalating energy demand in residential areas. The relationship between the United
States and other energy export states will continue to change as the United States
becomes more independent and non-OPEC resources become worthwhile especially
in Western Hemisphere. With expansion of global economic growth, maintained
multilateral relationship among countries and technological development are two
prominent concerns to secure long-term energy supplies and to enable further
exploration of new energy sources.
Integrated palm oil mill effluent treatment and co2 sequestration by microalgae

Nur Anira Syafiqah Hazman, Hassimi Abu Hasan, Kamrul Fakir Kamarudin, Nazlina Haiza Mohd Yasin, Mohd Sobri Takriff, Noor Irma Nazashida Mohd Hakimi

Sains Malaysiana, 2018;47:1455-1464.

Malaysian economy relies on palm oil industries as a driver for rural development. However, palm oil mill effluent
(POME) that is generated from palm oil processing stages causes major environmental challenges. Before being
released to the environment, POME treatment is crucial to comply with standard discharge limit. Microalgae have
demonstrated excellent potential for phycoremediating POME and capturing CO2
. In this study, local microalgae isolate
such as Chlamydomonas sp. UKM 6 and Chlorella spp. UKM 8 were used for POME treatment in 21 days with different
inoculum sizes (5%, 10% and 15%). In addition, an integrated treatment process was performed by taking the treated
POME supernatant for cultivation of Chorella spp. UKM 2, Chorella sorokiniana UKM 3 and Chlorella vulgaris for CO2
sequestration study. Different CO2
concentrations (5%, 10% and 15%) were used and the experiments were carried
out in 10 days under continuous illumination. The results showed that among two species involves in POME treatment,
Chlamydomonas sp. UKM 6 showed a great potential to remove pollutant such as COD (56%), nitrogen (65%) and
phosphorus (34%). The biomass after POME treatment and CO2
biofixation content high lipid (90 mg lipid/g biomass)
which can be the potential source for biodiesel production. In CO2
sequestration study, C. sorokininana UKM3 able
to takes up to 15% CO2
with CO2
uptake rate of 273 mgL-1d-1. In this study, the integrated system of POME treatment
and CO2
sequestration were feasible using microalgae.
Fulltext Prevalence and risk factors associated with Entamoeba histolytica/dispar/moshkovskii infection among three Orang Asli ethnic groups in Malaysia

Shahrul Anuar T, M Al-Mekhlafi H, Abdul Ghani MK, Osman E, Mohd Yasin A, Nordin A, et al.

PLoS One, 2012;7(10):e48165.
PMID: 23133561 DOI: 10.1371/journal.pone.0048165

BACKGROUND: Entamoeba histolytica/Entamoeba dispar/Entamoeba moshkovskii infection is still prevalent in rural Malaysia especially among Orang Asli communities. Currently, information on prevalence of this infection among different ethnic groups of Orang Asli is unavailable in Malaysia. To contribute to a better comprehension of the epidemiology of this infection, a cross-sectional study aimed at providing the first documented data on the prevalence and risk factors associated with E. histolytica/E. dispar/E. moshkovskii infection was carried out among three Orang Asli ethnic groups (Proto-Malay, Negrito, and Senoi) in selected villages in Negeri Sembilan, Perak, and Pahang states, Malaysia.
METHODS/FINDINGS: Faecal samples were examined by formalin-ether sedimentation and trichrome staining techniques. Of 500 individuals, 8.7% (13/150) of Proto-Malay, 29.5% (41/139) of Negrito, and 18.5% (39/211) of Senoi were positive for E. histolytica/E. dispar/E. moshkovskii, respectively. The prevalence of this infection showed an age-dependency relationship, with higher rates observed among those aged less than 15 years in all ethnic groups studied. Multivariate analysis confirmed that not washing hands after playing with soils or gardening and presence of other family members infected with E. histolytica/E. dispar/E. moshkovskii were significant risk factors of infection among all ethnic groups. However, eating with hands, the consumption of raw vegetables, and close contact with domestic animals were identified as significant risk factors in Senoi.
CONCLUSIONS: Essentially, the findings highlighted that E. histolytica/E. dispar/E. moshkovskii parasites are still prevalent in Malaysia. Further studies using molecular approaches to distinguish the morphologically identical species of pathogenic, E. histolytica from the non-pathogenic, E. dispar and E. moshkovskii are needed. The establishment of such data will be beneficial for the public health authorities in the planning and implementation of specific prevention and control strategies of this infection in different Orang Asli ethnic groups in Malaysia.
Fulltext Optimized Intelligent Classifier for Early Breast Cancer Detection Using Ultra-Wide Band Transceiver

Halim AAA, Andrew AM, Mustafa WA, Mohd Yasin MN, Jusoh M, Veeraperumal V, et al.

Diagnostics (Basel), 2022 Nov 19;12(11).
PMID: 36428930 DOI: 10.3390/diagnostics12112870

Breast cancer is the most common cancer diagnosed in women and the leading cause of cancer-related deaths among women worldwide. The death rate is high because of the lack of early signs. Due to the absence of a cure, immediate treatment is necessary to remove the cancerous cells and prolong life. For early breast cancer detection, it is crucial to propose a robust intelligent classifier with statistical feature analysis that considers parameter existence, size, and location. This paper proposes a novel Multi-Stage Feature Selection with Binary Particle Swarm Optimization (MSFS-BPSO) using Ultra-Wideband (UWB). A collection of 39,000 data samples from non-tumor and with tumor sizes ranging from 2 to 7 mm was created using realistic tissue-like dielectric materials. Subsequently, the tumor models were inserted into the heterogeneous breast phantom. The breast phantom with tumors was imaged and represented in both time and frequency domains using the UWB signal. Consequently, the dataset was fed into the MSFS-BPSO framework and started with feature normalization before it was reduced using feature dimension reduction. Then, the feature selection (based on time/frequency domain) using seven different classifiers selected the frequency domain compared to the time domain and continued to perform feature extraction. Feature selection using Analysis of Variance (ANOVA) is able to distinguish between class-correlated data. Finally, the optimum feature subset was selected using a Probabilistic Neural Network (PNN) classifier with the Binary Particle Swarm Optimization (BPSO) method. The research findings found that the MSFS-BPSO method has increased classification accuracy up to 96.3% and given good dependability even when employing an enormous data sample.
Chondrogenesis of adipose-derived stem cells with chondrocytes in low serum towards clinical application

Adila A Hamid, Satish Vaarman Jeyabalan, Aleza Omar, Nik Zattil Hanan Mohd Yasin, Wong TL, Liau LL, et al.

Sains Malaysiana, 2018;47:2369-2379.

Currently, fetal bovine serum (FBS) have been widely use in culture media to promote human cell proliferation. However,
the usage of FBS for cell therapy in clinical application was associated with the risk of viral and prion transmission as
well as immune rejection. To provide an option for this risk, this study was conducted to determine the effect of adipose
derived stem cells (ADSCs) co-culture with chondrocyte in promoting cell proliferation and chondrogenesis toward
FBS free condition. ADSCs co-cultured with chondrocyte at the ratio of 1:1, 2:1 and 1:2 were tested. Cell morphology
changes, cell proliferation and gene expression level of stemness (Oct4, FGF-4, Nanog) and chondrogenic (Collagen
Type II, ACP) were assessed. The results showed ADSCs in all co-culture groups changed morphology from fibroblastic
spindle to polygonal shape which resembled chondrocytes. The morphological changes were accompanied with increased
expression of chondrogenic genes; denoted chondrogenesis process. While maintaining expression of stemness genes
indicated continuation of cell proliferation. From the three co-culture groups tested; ADSCs and chondrocytes (1:1 ratio)
have been shown to exert better effects in promoting cell proliferation and chondrogenesis. In conclusion, ADSCs could
replace FBS to grow sufficient number of chondrogenic cells to repair cartilage injury in the near future. Further in vivo
study should be performed to test the effectiveness of this co-culture technique in cartilage injury repair.
Rare coinheritance of hemoglobin vancleave with severe beta-thalassemia mutation in a patient with secondary erythrocytosis

Aziz NA, Musa NH, Mathews M, Rajenderan KT, Abdul Hamid FS, Hassan S, et al.

Hum Genome Var, 2024 Apr 23;11(1):19.
PMID: 38653961 DOI: 10.1038/s41439-024-00275-y

Hemoglobin (Hb) Vancleave (NM_000518.5:c.431 A > T; dbSNP: rs33918338) is an extremely rare structural hemoglobin variant worldwide, and studies are limited. This report describes the case of a 16-year-old male patient who presented with secondary erythrocytosis. The diagnosis of Hb Vancleave, in combination with codon 41/42 (-TTCT) (NM_000518.5:c.126_129del; dbSNP: rs80356821), was confirmed by direct sequencing. This report highlights the importance of sequencing in the differential diagnosis of beta-thalassemia syndrome in Malaysia.
Global Globin Network and adopting genomic variant database requirements for thalassemia

Halim-Fikri H, Zulkipli NN, Alauddin H, Bento C, Lederer CW, Kountouris P, et al.

Database (Oxford), 2024 Sep 04;2024.
PMID: 39231257 DOI: 10.1093/database/baae080

Thalassemia is one of the most prevalent monogenic disorders in low- and middle-income countries (LMICs). There are an estimated 270 million carriers of hemoglobinopathies (abnormal hemoglobins and/or thalassemia) worldwide, necessitating global methods and solutions for effective and optimal therapy. LMICs are disproportionately impacted by thalassemia, and due to disparities in genomics awareness and diagnostic resources, certain LMICs lag behind high-income countries (HICs). This spurred the establishment of the Global Globin Network (GGN) in 2015 at UNESCO, Paris, as a project-wide endeavor within the Human Variome Project (HVP). Primarily aimed at enhancing thalassemia clinical services, research, and genomic diagnostic capabilities with a focus on LMIC needs, GGN aims to foster data collection in a shared database by all affected nations, thus improving data sharing and thalassemia management. In this paper, we propose a minimum requirement for establishing a genomic database in thalassemia based on the HVP database guidelines. We suggest using an existing platform recommended by HVP, the Leiden Open Variation Database (LOVD) (https://www.lovd.nl/). Adoption of our proposed criteria will assist in improving or supplementing the existing databases, allowing for better-quality services for individuals with thalassemia. Database URL: https://www.lovd.nl/.