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Fulltext Liquid-Based Reconfigurable Antenna Technology: Recent Developments, Challenges and Future

Abu Bakar H, Abd Rahim R, Soh PJ, Akkaraekthalin P

Sensors (Basel), 2021 Jan 26;21(3).
PMID: 33530534 DOI: 10.3390/s21030827

Advances in reconfigurable liquid-based reconfigurable antennas are enabling new possibilities to fulfil the requirements of more advanced wireless communication systems. In this review, a comparative analysis of various state-of-the-art concepts and techniques for designing reconfigurable antennas using liquid is presented. First, the electrical properties of different liquids at room temperature commonly used in reconfigurable antennas are identified. This is followed by a discussion of various liquid actuation techniques in enabling high frequency reconfigurability. Next, the liquid-based reconfigurable antennas in literature used to achieve the different types of reconfiguration will be critically reviewed. These include frequency-, polarization-, radiation pattern-, and compound reconfigurability. The current concepts of liquid-based reconfigurable antennas can be classified broadly into three basic approaches: altering the physical (and electrical) dimensions of antennas using liquid; applying liquid-based sections as reactive loads; implementation of liquids as dielectric resonators. Each concept and their design approaches will be examined, outlining their benefits, limitations, and possible future improvements.
Fulltext Learning environment assessments of a single curriculum being taught at two medical schools 10,000 miles apart

Tackett S, Shochet R, Shilkofski NA, Colbert-Getz J, Rampal K, Abu Bakar H, et al.

BMC Med Educ, 2015;15:105.
PMID: 26081751 DOI: 10.1186/s12909-015-0388-0

Perdana University Graduate School of Medicine (PUGSOM), the first graduate-entry medical school in Malaysia, was established in 2011 in collaboration with Johns Hopkins University School of Medicine (JHUSOM), an American medical school. This study compared learning environments (LE) at these two schools, which shared the same overarching curriculum, along with a comparator Malaysian medical school, Cyberjaya University College of Medical Sciences (CUCMS). As a secondary aim, we compared 2 LE assessment tools - the widely-used Dundee Ready Educational Environment Measure (DREEM) and the newer Johns Hopkins Learning Environment Scale (JHLES).
Antimicrobial and cytotoxic activities of Malaysian endophytes

Ramasamy K, Lim SM, Abu Bakar H, Ismail N, Ismail MS, Ali MF, et al.

Phytother Res, 2010 May;24(5):640-3.
PMID: 19468989 DOI: 10.1002/ptr.2891

Endophytes, which are receiving increasing attention, have been found to be potential sources of bioactive metabolites following the discovery of paclitaxel producing endophytic fungi. In the present study, a total of 348 endophytes were isolated from different parts of 24 Malaysian medicinal plants. Three selected endophytes (HAB10R12, HAB11R3 and HAB21F25) were investigated for their antimicrobial and cytotoxic activities. For antimicrobial activity, HAB10R12 and HAB11R3 were found to be most active against bacteria and fungi, respectively. Their antimicrobial effects were comparable to, if not better than, a number of current commercial antibacterial and antifungal agents. Both HAB10R12 and HAB21F25 were found to be potential anticancer drug candidates, having potent activity against MCF-7 and HCT116 cell lines and warrant further investigation.
Diketopiperazine and isoindolinone alkaloids from the endophytic fungus Aspergillus sp. HAB10R12

Al-Khdhairawi AAQ, Loo JSE, Abd Mutalib N, Abd Latip N, Manshoor N, Abu Bakar H, et al.

Phytochemistry, 2023 Jul;211:113685.
PMID: 37088350 DOI: 10.1016/j.phytochem.2023.113685

Four previously undescribed alkaloids, aspergillinine A-D, and four known diterpene pyrones were isolated from the potato dextrose agar (PDA) culture of Aspergillus sp. HAB10R12. The chemical structures of the isolated compounds were elucidated based on a detailed analysis of their NMR and MS data. The absolute configuration of the isolated compounds was determined by Electronic Circular Dichroism analysis coupled with computational methods. Aspergillinine A represents the first example of a diketopiperazine dipeptide containing the unnatural amino acid N-methyl kynurenine. Its absolute configuration revealed that it adopts a rather unusual conformation. Aspergillinine B represents a previously unencountered skeleton containing an isoindolinone ring. Aspergillinine C and D were similar to previously isolated diketopiperazine alkaloids, namely, lumpidin and brevianamide F, respectively. The diterpene pyrones were isolated twice previously, once from a soil-derived Aspergillus species, and once from the liquid culture of Aspergillus sp. HAB10R12. The alkaloids isolated in this study showed no antiproliferative activity when tested against HepG2 and A549 cancer cell lines.
Retrospective review of the prevalence and risk factors of anaemia among antenatal mothers attending health clinics in Alor Gajah, Melaka

Ali N, Nur Kalmi Z, Sanusi NS, Ahad A, Mohd Khairuddin NA, Rosman SR, et al.

Malays Fam Physician, 2022 Nov 30;17(3):137-143.
PMID: 36606167 DOI: 10.51866/oa.135

INTRODUCTION: Anaemia is common during pregnancy and can lead to miscarriage, intrauterine growth retardation, premature labour and antepartum haemorrhage. Anaemia in pregnancy is defined as a haemoglobin (Hb) level of <11 g/dL.
METHOD: This retrospective review included 407 antenatal mothers diagnosed with anaemia at 36±1 weeks of gestation at all 10 health clinics in Alor Gajah between January and December 2018.
RESULTS: According to the district annual returns, 2,407 antenatal mothers (36 weeks of gestation) were registered in the health clinics in Alor Gajah in 2018. Among them, the prevalence of anaemia was 18.6% (n=448). However, there were only 407 cards found. Most participants were Malays (89.4%), aged 20-40 years (93.6%) and married (96.3%). Almost all anaemia cases (96.5%) were mild (Hb level of 9-10.9 g/dL). Approximately 34.4% of the mothers were already anaemic at booking; 77.6% belonged to the B40 income group; and 31.6% had poor pregnancy spacing of <2 years. Iron deficiency anaemia was the most common type of anaemia (51.0%), followed by dilutional anaemia (34.0%), which did not normalise at 36 weeks of gestation. Anaemia was associated with lower educational (p<0.05) and Hb levels at booking (p<0.001).
CONCLUSION: Having normal maternal Hb levels in early pregnancy especially at booking is crucial, as it may reduce the possibility of anaemia during pregnancy. Early screening and supplementation of at-risk pregnancies may be applied as a preventive strategy. Suitable methods of iron treatment and investigation need further exploration.