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The effects of metamaterial on electromagnetic fields absorption characteristics of human eye tissues

Gasmelseed A, Yunus J

Prog Biophys Mol Biol, 2014 Jan;114(1):8-12.
PMID: 24239501 DOI: 10.1016/j.pbiomolbio.2013.10.004

The interaction of a dipole antenna with a human eye model in the presence of a metamaterial is investigated in this paper. The finite difference time domain (FDTD) method with convolutional perfectly matched layer (CPML) formulation have been used. A three-dimensional anatomical model of the human eye with resolution of 1.25 mm × 1.25 mm × 1.25 mm was used in this study. The dipole antenna was driven by modulated Gaussian pulse and the numerical study is performed with dipole operating at 900 MHz. The analysis has been done by varying the size and value of electric permittivity of the metamaterial. By normalizing the peak SAR (1 g and 10 g) to 1 W for all examined cases, we observed how the SAR values are not affected by the different permittivity values with the size of the metamaterial kept fixed.
Assessing Auditory Discrimination Skill of Malay Children Using Computer-based Method

Ting H, Yunus J, Mohd Nordin MZ

Conf Proc IEEE Eng Med Biol Soc, 2007 2 7;2005:2498-501.
PMID: 17282745

The purpose of this paper is to investigate the auditory discrimination skill of Malay children using computer-based method. Currently, most of the auditory discrimination assessments are conducted manually by Speech-Language Pathologist. These conventional tests are actually general tests of sound discrimination, which do not reflect the client's specific speech sound errors. Thus, we propose computer-based Malay auditory discrimination test to automate the whole process of assessment as well as to customize the test according to the specific speech error sounds of the client. The ability in discriminating voiced and unvoiced Malay speech sounds was studied for the Malay children aged between 7 and 10 years old. The study showed no major difficulty for the children in discriminating the Malay speech sounds except differentiating /g/-/k/ sounds. Averagely the children of 7 years old failed to discriminate /g/-/k/ sounds.
Chlorogenic acid ameliorates muscle wasting by upregulating mRNA expressions of calcineurin and PGC-1α in diabetic rat model

Siwi K, Tejosukmono A, Anggorowati N, Arfian N, Yunus J

Med J Malaysia, 2024 Aug;79(Suppl 4):23-30.
PMID: 39215411

INTRODUCTION: Muscle health in diabetes mellitus (DM) is often neglected, which leads to muscle wasting. Increased reactive oxygen species in DM could decrease antioxidant enzymes such as superoxide dismutase-1 (SOD-1) and -2 (SOD-2) and inhibit calcineurin (CN) and PGC-1α signalling pathways. Chlorogenic acid (CGA) is known as a potent antioxidant and activators of CN and PGC-1α. This study aimed to determine the effect of CGA on mRNA expressions of SOD-1, SOD-2, CN and PGC-1α in inhibiting the progression of DM to muscle wasting.
MATERIALS AND METHODS: This study was conducted at Department of Anatomy, Faculty of Medicine, Public Health, and Nursing, Universitas Gadjah Mada starting on July 20th, 2020. A total of 24 male Wistar rats were randomly divided into six groups (four rats per group), i.e., control, DM 1.5 months (DM1.5), and DM 2 months (DM2); and DM groups treated with CGA in three different doses, namely CGA1 (12.5 mg/kg BW), CGA2 (25 mg/kg BW), and CGA3 (50 mg/kg BW). Control group was only injected with normal saline, while diabetic model was induced by intraperitoneal injection of streptozotocin. Blood glucose levels were measured twice (one week after diabetic induction and before termination). The soleus muscle tissue was harvested to analyse the mRNA expressions of SOD-1, SOD- 2, CN and PGC-1α using RT-PCR. In addition, the tissue samples were stained with immunohistochemistry for CN and haematoxylin-eosin (HE) for morphologic analysis under light microscopy.
RESULTS: The mRNA expressions of SOD-1 and SOD-2 in the CGA1 group were relatively higher compared to the DM2 groups. The mRNA expression of CN in the CGA1 group was significantly higher compared to the DM2 group (p = 0.008). The mRNA expression of PGC-1α in the CGA1 group was significantly higher compared to the DM2 group (p = 0.025). Immunohistochemical staining showed that CNimmunopositive expression in the CGA1 group was more evident compared to the other groups. Haematoxylin-eosin staining showed that muscle tissue morphology in the CGA1 group was similar to that in the control group.
CONCLUSION: Chlorogenic acid at a dose of 12.5 mg/kg BW shows lower blood glucose level, good skeletal muscle tissue morphology and higher mRNA expressions of SOD-1, SOD-2, CN and PGC-1α compared to the DM groups.
Extraction of dynamic features from hand drawn data for the identification of children with handwriting difficulty

Khalid PI, Yunus J, Adnan R

Res Dev Disabil, 2010 Jan-Feb;31(1):256-62.
PMID: 19854613 DOI: 10.1016/j.ridd.2009.09.009

Studies have shown that differences between children with and without handwriting difficulties lie not only in the written product (static data) but also in dynamic data of handwriting process. Since writing system varies among countries and individuals, this study was conducted to determine the feasibility of using quantitative outcome measures of children's drawing to identify children who are at risk of handwriting difficulties. A sample of 143 first graders of a normal primary school was investigated regarding their handwriting ability. The children were divided into two groups: test and control. Ten children from test group and 40 children from control group were individually tested for their Visual Motor Integration skills. Analysis on dynamic data indicated significant differences between the two groups in temporal and spatial measures of the drawing task performance. Thus, kinematic analysis of children's drawing is feasible to provide performance characteristic of handwriting ability, supporting its use in screening for handwriting difficulty.
Fulltext The effect of Ramadan fasting on spatial attention through emotional stimuli

Molavi M, Yunus J, Utama NP

Psychol Res Behav Manag, 2016;9:105-14.
PMID: 27307772 DOI: 10.2147/PRBM.S100495

Fasting can influence psychological and mental states. In the current study, the effect of periodical fasting on the process of emotion through gazed facial expression as a realistic multisource of social information was investigated for the first time. The dynamic cue-target task was applied via behavior and event-related potential measurements for 40 participants to reveal the temporal and spatial brain activities - before, during, and after fasting periods. The significance of fasting included several effects. The amplitude of the N1 component decreased over the centroparietal scalp during fasting. Furthermore, the reaction time during the fasting period decreased. The self-measurement of deficit arousal as well as the mood increased during the fasting period. There was a significant contralateral alteration of P1 over occipital area for the happy facial expression stimuli. The significant effect of gazed expression and its interaction with the emotional stimuli was indicated by the amplitude of N1. Furthermore, the findings of the study approved the validity effect as a congruency between gaze and target position, as indicated by the increment of P3 amplitude over centroparietal area as well as slower reaction time from behavioral response data during incongruency or invalid condition between gaze and target position compared with those during valid condition. Results of this study proved that attention to facial expression stimuli as a kind of communicative social signal was affected by fasting. Also, fasting improved the mood of practitioners. Moreover, findings from the behavioral and event-related potential data analyses indicated that the neural dynamics of facial emotion are processed faster than that of gazing, as the participants tended to react faster and prefer to relay on the type of facial emotions than to gaze direction while doing the task. Because of happy facial expression stimuli, right hemisphere activation was more than that of the left hemisphere. It indicated the consistency of the emotional lateralization concept rather than the valence concept of emotional processing.
Debridement efficacy of serine protease and formulated cream by In Vitro assessment against artificial wound eschar

Yunus J, Jamaluddin H, Wan Dagang WRZ

Enzyme Microb Technol, 2024 Jul 11;180:110478.
PMID: 39074421 DOI: 10.1016/j.enzmictec.2024.110478

Chronic wounds typically comprise of necrotic tissue and dried secretions, often culminating in the formation of a thick and tough layer of dead skin known as eschar. Removal of eschar is imperative to facilitate wound healing. Conventional approach for eschar removal involves surgical excision and grafting, which can be traumatic and frequently leads to viable tissue damage. There has been growing interest in the use of enzymatic agents for a gentler approach to debridement, utilizing proteolytic enzymes. In this study, a purified intracellular recombinant serine protease from Bacillus sp. (SPB) and its cream formulation were employed to evaluate their ability to degrade artificial wound eschar; composed of collagen, fibrin, and elastin. Degradation was assessed based on percentage weight reduction of eschar biomass, analysis via sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), and scanning electron microscopy (SEM). Both SPB and its cream formulation were able to degrade up to 50 % artificial wound eschar, with the SPB cream maintaining its degradation efficiency for up to 24 hours. Additionally, the SPB-based cream demonstrated the ability to hydrolyze proteinaceous components of eschars individually (fibrin and collagen) as determined through qualitative assessment. These findings suggest that SPB holds promise for the debridement of wound eschar.
Outcomes of children with long-segment and total colon Hirschsprung disease following pull-through

Wardhani AK, Dwiantama K, Iskandar K, Yunus J, Gunadi

Med J Malaysia, 2024 Aug;79(Suppl 4):1-5.
PMID: 39215407

INTRODUCTION: Hirschsprung disease (HSCR) is a congenital disorder caused by the absence of ganglion cells, which leads to a functional obstruction in infants. HSCR is divided into short, long and total colon aganglionosis (TCA). However, post-operative outcome assessment of patients with long-segment and TCA is scarce. We determined the functional outcomes, Hirschsprung-associated enterocolitis (HAEC) and complications of long-segment and TCA HSCR's children following pull-through surgery.
MATERIALS AND METHODS: Descriptive analysis research was done for children with HSCR long-segment and TCA who underwent an operation at our institutionfrom 2013 to 2020. We assessed the functional outcome and HAEC by the Krickenbeck and the HAEC scoring, respectively.
RESULTS: We ascertained 13 HSCR long-segment and six TCA. We performed the following surgical procedures: Duhamel (n=7), Martin (n=4), Kimura (n=1), transabdominal Yancey-Soave (n=3) and transanal endorectal pull-through (n=4). All long-segment patients revealed good functional outcomes, whereas two TCA children suffered soiling and failed to achieve voluntary bowel movement. HAEC was noted in three long-segment and four TCA patients. Furthermore, surgical site infection and diaper rash were noticed in 10 and two patients, respectively.
CONCLUSION: Long-segment patients might have better functional outcomes TCA group, whereas the frequency of HAEC is compatible among arms. Long-term follow-up is important and necessary to identify complications early and define the proper treatment. Our study comprehensively analyzes functional outcomes, HAEC and complications of children with HSCR long-segment and TCA after definitive surgery in a developing country.
Fulltext Upregulation of p16, Bax and Bcl-2 mRNA Expression Associated with Epithelial Apoptosis and Myofibroblast Proliferation in Kidney Fibrosis Model in Mice

Sulistiyowati I, Yunus J, Sari DCR, Arfian N

Malays J Med Sci, 2020 Mar;27(2):37-44.
PMID: 32788839 DOI: 10.21315/mjms2020.27.2.4

BACKGROUND: Cellular senescence may play a role in the development of kidney fibrosis, but its specific association with apoptosis or proliferation have yet to be determined.
OBJECTIVES: This study aims to determine the effects of unilateral ureteral obstruction (UUO) on proliferation, cellular senescence and apoptosis in kidney fibrosis.
METHODS: A unilateral ureteral obstruction (UUO) procedure was performed to induce kidney fibrosis in 24 Swiss mice (3 months old, 30 g-40 g). Mice were sacrificed on day 3 (UUO3, n = 6), day 7 (UUO7, n = 6) and day 14 (UUO14, n = 6). Sham operation (SO) procedures were performed on the control group. The expression of Bcl-2, p16 and Bax mRNA was quantified with reverse transcription polymerase chain reaction (RT-PCR). Immunohistochemical (IHC) staining with anti-Bcl-2 and p53 antibodies was used to determine the localisation of proliferation and apoptosis. Data were analysed using one-way ANOVA followed by a post hoc least significant difference (LSD) test (P < 0.05).
RESULTS: RT-PCR analysis showed higher mRNA expression of Bcl-2, p16 and Bax in the UUO groups compared with SO group (P < 0.05). Immunostaining showed that Bcl-2 and p53 expression in tubular epithelium in the UUO groups, except Bcl-2 expression was found in interstitial areas of UUO14 group.
CONCLUSION: Senescence in UUO might be associated with epithelial apoptosis and myofibroblast proliferation.
Fulltext Expression of an organic solvent stable lipase from Staphylococcus epidermidis AT2

Rahman RN, Kamarudin NH, Yunus J, Salleh AB, Basri M

Int J Mol Sci, 2010;11(9):3195-208.
PMID: 20957088 DOI: 10.3390/ijms11093195

An organic solvent tolerant lipase gene from Staphylococcus epidermidis AT2 was successfully cloned and expressed with pTrcHis2 in E. coli TOP10. Sequence analysis revealed an open reading frame (ORF) of 1,933 bp in length which coded for a polypeptide of 643 amino acid residues. The polypeptide comprised of a signal peptide (37 amino acids), pro-peptide and a mature protein of 390 amino acids. Expression of AT2 lipase resulted in an 18-fold increase in activity, upon the induction of 0.6 mM IPTG after a 10 h incubation period. Interestingly, this lipase was stable in various organic solvents (25% (v/v), mainly toluene, octanol, p-xylene and n-hexane). Literature shows that most of the organic solvent stable bacterial lipases were produced by Pseudomonas sp. and Bacillus sp., but very few from Staphylococcus sp. This lipase demonstrates great potential to be employed in various industrial applications.
The use of graphic rules in grade one to help identify children at risk of handwriting difficulties

Khalid PI, Yunus J, Adnan R, Harun M, Sudirman R, Mahmood NH

Res Dev Disabil, 2010 Nov-Dec;31(6):1685-93.
PMID: 20554150 DOI: 10.1016/j.ridd.2010.04.005

Previous researches on elementary grade handwriting revealed that pupils employ certain strategy when writing or drawing. The relationship between this strategy and the use of graphic rules has been documented but very little research has been devoted to the connection between the use of graphic rules and handwriting proficiency. Thus, this study was conducted to investigate the relative contribution of the use of graphic rules to the writing ability. A sample of 105 first graders who were average printers and 65 first graders who might experience handwriting difficulty, as judged by their teachers, of a normal primary school were individually tested on their use of graphic rules. It has been found that pupils who are below average printers use more non-analytic strategy than average printers to reproduce the figures. The results also reveal that below average printers do not acquire the graphic principles that foster an analytic approach to production skills. Although the findings are not sufficient to allow definitive conclusions about handwriting ability, it can be considered as one of the screening measures in identifying pupils who are at risk of handwriting difficulties.
Thermal distribution analysis of three-dimensional tumor-embedded breast models with different breast density compositions

Wahab AA, Salim MI, Ahamat MA, Manaf NA, Yunus J, Lai KW

Med Biol Eng Comput, 2016 Sep;54(9):1363-73.
PMID: 26463520 DOI: 10.1007/s11517-015-1403-7

Breast cancer is the most common cancer among women globally, and the number of young women diagnosed with this disease is gradually increasing over the years. Mammography is the current gold-standard technique although it is known to be less sensitive in detecting tumors in woman with dense breast tissue. Detecting an early-stage tumor in young women is very crucial for better survival chance and treatment. The thermography technique has the capability to provide an additional functional information on physiological changes to mammography by describing thermal and vascular properties of the tissues. Studies on breast thermography have been carried out to improve the accuracy level of the thermography technique in various perspectives. However, the limitation of gathering women affected by cancer in different age groups had necessitated this comprehensive study which is aimed to investigate the effect of different density levels on the surface temperature distribution profile of the breast models. These models, namely extremely dense (ED), heterogeneously dense (HD), scattered fibroglandular (SF), and predominantly fatty (PF), with embedded tumors were developed using the finite element method. A conventional Pennes' bioheat model was used to perform the numerical simulation on different case studies, and the results obtained were then compared using a hypothesis statistical analysis method to the reference breast model developed previously. The results obtained show that ED, SF, and PF breast models had significant mean differences in surface temperature profile with a p value <0.025, while HD breast model data pair agreed with the null hypothesis formulated due to the comparable tissue composition percentage to the reference model. The findings suggested that various breast density levels should be considered as a contributing factor to the surface thermal distribution profile alteration in both breast cancer detection and analysis when using the thermography technique.
Chlorogenic acid attenuates kidney fibrosis via antifibrotic action of BMP-7 and HGF

Yunus J, Salman M, Lintin GBR, Muchtar M, Sari DCR, Arfian N, et al.

Med J Malaysia, 2020 05;75(Suppl 1):5-9.
PMID: 32471962

BACKGROUND: Kidney fibrosis, characterised by tubulointerstitial fibrosis, is a histological landmark of chronic kidney disease. The body attempts to compensate for progressive detrimental process of kidney fibrosis by producing antifibrotic substances, such as bone morphogenetic protein-7 (BMP-7) and hepatocyte growth factor (HGF). Chlorogenic acid is known to have renoprotective and antifibrotic properties. This study aims to evaluate the effect of chlorogenic acid on unilateral ureteral obstruction (UUO)-induced kidney fibrosis mice model.
METHODS: This study was a quasi-experimental with posttestonly control group design. Twenty-five adult male Swiss Webster mice were randomly divided into five groups: shamoperated group (SO), UUO-control day-7 (U7), UUO-control day-14 (U14), UUO-chlorogenic acid day-7 (UC7), and UUOchlorogenic acid day 14 (UC14). Myofibroblasts were identified by immunohistochemical staining of alphasmooth muscle actin (α-SMA) while collagen fibers were identified by Sirius Red staining. Both data were presented as area fraction. BMP-7 and HGF mRNA expressions were assessed by reverse transcription PCR (RT-PCR). Data were quantified using ImageJ software.
RESULTS: UUO-control groups (U7 and U14) showed higher α- SMA-immunopositive (6.52±1.33, 18.24±1.39 vs. 0.22±0.01; p<0.05) and Sirius Red-positive area fractions (6.61±0.8, 12.98±2.31 vs. 0.62±0.10; p<0.05), lower BMP-7 (1.02±0.47, 1.18±0.65 vs. 2.09±0.87; p<0.05) and HGF mRNA expressions (1.06±0.31, 0.89±0.14 vs. 1.88±0.81; p<0.05) compared to SO group. UUO-chlorogenic acid groups (UC7 and UC14) showed lower α-SMA-immunopositive (1.24±0.37, 4.58±0.61; p<0.05) and Sirius Red-positive area fractions (4.76±1.03, 3.72±0.54; p<0.05), higher BMP-7 (1.84±0.49, 2.19±0.43; p<0.05) and HGF (1.58±0.38; p>0.05, 1.84±0.42; p<0.05) mRNA expressions compared to UUO-control groups. UUOchlorogenic acid groups showed BMP-7 and HGF mRNA expressions that were not significantly different from the SO group.
CONCLUSION: Chlorogenic acid administration prevents kidney fibrosis in UUO mice model through modulating antifibrotic pathway.
Fulltext Erratum: Solitonic conduction of electrotonic signals in neuronal branchlets with polarized microstructure

Poznanski RR, Cacha LA, Al-Wesabi YMS, Ali J, Bahadoran M, Yupapin PP, et al.

Sci Rep, 2017 09 06;7(1):10675.
PMID: 28878253 DOI: 10.1038/s41598-017-07626-6

A correction to this article has been published and is linked from the HTML version of this paper. The error has been fixed in the paper.
Fulltext Solitonic conduction of electrotonic signals in neuronal branchlets with polarized microstructure

Poznanski RR, Cacha LA, Al-Wesabi YMS, Ali J, Bahadoran M, Yupapin PP, et al.

Sci Rep, 2017 May 31;7(1):2746.
PMID: 28566682 DOI: 10.1038/s41598-017-01849-3

A model of solitonic conduction in neuronal branchlets with microstructure is presented. The application of cable theory to neurons with microstructure results in a nonlinear cable equation that is solved using a direct method to obtain analytical approximations of traveling wave solutions. It is shown that a linear superposition of two oppositely directed traveling waves demonstrate solitonic interaction: colliding waves can penetrate through each other, and continue fully intact as the exact pulses that entered the collision. These findings indicate that microstructure when polarized can sustain solitary waves that propagate at a constant velocity without attenuation or distortion in the absence of synaptic transmission. Solitonic conduction in a neuronal branchlet arising from polarizability of its microstructure is a novel signaling mode of electrotonic signals in thin processes (<0.5 μm diameter).
Bacterial biofilm growth and perturbation by serine protease from Bacillus sp

Yunus J, Wan Dagang WRZ, Jamaluddin H, Jemon K, Mohamad SE, Jonet MA

Arch Microbiol, 2024 Mar 04;206(4):138.
PMID: 38436775 DOI: 10.1007/s00203-024-03857-0

In nature, bacteria are ubiquitous and can be categorized as beneficial or harmless to humans, but most bacteria have one thing in common which is their ability to produce biofilm. Biofilm is encased within an extracellular polymeric substance (EPS) which provides resistance against antimicrobial agents. Protease enzymes have the potential to degrade or promote the growth of bacterial biofilms. In this study, the effects of a recombinant intracellular serine protease from Bacillus sp. (SPB) on biofilms from Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa were analyzed. SPB was purified using HisTrap HP column and concentrated using Amicon 30 ultra-centrifugal filter. SPB was added with varying enzyme activity and assay incubation period after biofilms were formed in 96-well plates. SPB was observed to have contrasting effects on different bacterial biofilms, where biofilm degradations were observed for both 7-day-old A. baumannii (37.26%) and S. aureus (71.51%) biofilms. Meanwhile, SPB promoted growth of P. aeruginosa biofilm up to 176.32%. Compatibility between protein components in S. aureus biofilm with SPB as well as a simpler membrane structure morphology led to higher biofilm degradation for S. aureus compared to A. baumannii. However, SPB promoted growth of P. aeruginosa biofilm due likely to its degrading protein factors that are responsible for biofilm detachment and dispersion, thus resulting in more multi-layered biofilm formation. Commercial protease Savinase which was used as a comparison showed degradation for all three bacterial biofilms. The results obtained are unique and will expand our understanding on the effects that bacterial proteases have toward biofilms.
Fulltext A Review on the Bioinformatics Tools for Neuroimaging

Man MY, Ong MS, Mohamad MS, Deris S, Sulong G, Yunus J, et al.

Malays J Med Sci, 2015 Dec;22(Spec Issue):9-19.
PMID: 27006633 MyJurnal

Neuroimaging is a new technique used to create images of the structure and function of the nervous system in the human brain. Currently, it is crucial in scientific fields. Neuroimaging data are becoming of more interest among the circle of neuroimaging experts. Therefore, it is necessary to develop a large amount of neuroimaging tools. This paper gives an overview of the tools that have been used to image the structure and function of the nervous system. This information can help developers, experts, and users gain insight and a better understanding of the neuroimaging tools available, enabling better decision making in choosing tools of particular research interest. Sources, links, and descriptions of the application of each tool are provided in this paper as well. Lastly, this paper presents the language implemented, system requirements, strengths, and weaknesses of the tools that have been widely used to image the structure and function of the nervous system.

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