Displaying publications 281 - 300 of 527 in total

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  1. Adeyemi KD, Ebrahimi M, Samsudin AA, Alimon AR, Karim R, Karsani SA, et al.
    Anim Sci J, 2015 Mar;86(3):270-8.
    PMID: 25377536 DOI: 10.1111/asj.12279
    The study appraised the effects of Carotino oil on in vitro rumen fermentation, gas production, metabolism and apparent biohydrogenation of oleic, linoleic and linolenic acids. Carotino oil was added to a basal diet (50% concentrate and 50% oil palm frond) at the rate of 0, 2, 4, 6 and 8% dry matter of the diet. Rumen inoculum was obtained from three fistulated Boer bucks and incubated with 200 mg of each treatment for 24 h at 39°C. Gas production, fermentation kinetics, in vitro organic matter digestibility (IVOMD), volatile fatty acids (VFA), in vitro dry matter digestibility (IVDMD), metabolizable energy and free fatty acids were determined. Carotino oil did not affect (P > 0.05) gas production, metabolizable energy, pH, IVOMD, IVDMD, methane, total and individual VFAs. However, Carotino oil decreased (P < 0.05) the biohydrogenation of linoleic and linolenic acids but enhanced (P < 0.05) the biohydrogenation of oleic acid. After 24 h incubation, the concentrations of stearic, palmitic, pentadecanoic, myristic, myristoleic and lauric acids decreased (P < 0.05) while the concentration of linolenic, linoleic, oleic and transvaccenic acids and conjugated linoleic acid (CLAc9t11) increased (P < 0.05) with increasing levels of Carotino oil. Carotino oil seems to enhance the accumulation of beneficial unsaturated fatty acids without disrupting rumen fermentation.
  2. Nugroho KC, Ubaidillah U, Arilasita R, Margono M, Priyambodo BH, Purnama B, et al.
    Materials (Basel), 2021 Jul 01;14(13).
    PMID: 34279258 DOI: 10.3390/ma14133684
    This study investigated the effect of adding strontium (Sr)-doped cobalt ferrite (CoFe2O4) nanoparticles in carbonyl iron particle (CIP)-based magnetorheological fluids (MRFs). Sr-CoFe2O4 nanoparticles were fabricated at different particle sizes using co-precipitation at calcination temperatures of 300 and 400 °C. Field emission scanning electron microscopy (FESEM) was used to evaluate the morphology of the Sr-CoFe2O4 nanoparticles, which were found to be spherical. The average grain sizes were 71-91 nm and 118-157 nm for nanoparticles that had been calcinated at 300 and 400 °C, respectively. As such, higher calcination temperatures were found to produce larger-sized Sr-CoFe2O4 nanoparticles. To investigate the rheological effects that Sr-CoFe2O4 nanoparticles have on CIP-based MRF, three MRF samples were prepared: (1) CIP-based MRF without nanoparticle additives (CIP-based MRF), (2) CIP-based MRF with Sr-CoFe2O4 nanoparticles calcinated at 300 °C (MRF CIP+Sr-CoFe2O4-T300), and (3) CIP-based MRF with Sr-CoFe2O4 nanoparticles calcinated at 400 °C (MRF CIP+Sr-CoFe2O4-T400). The rheological properties of these MRF samples were then observed at room temperature using a rheometer with a parallel plate at a gap of 1 mm. Dispersion stability tests were also performed to determine the sedimentation ratio of the three CIP-based MRF samples.
  3. Syafruddin SE, Nazarie WFWM, Moidu NA, Soon BH, Mohtar MA
    BMC Cancer, 2021 Jul 23;21(1):850.
    PMID: 34301218 DOI: 10.1186/s12885-021-08591-0
    BACKGROUND: Glioblastoma multiforme (GBM) is a highly lethal, stage IV brain tumour with a prevalence of approximately 2 per 10,000 people globally. The cell surface proteins or surfaceome serve as information gateway in many oncogenic signalling pathways and are important in modulating cancer phenotypes. Dysregulation in surfaceome expression and activity have been shown to promote tumorigenesis. The expression of GBM surfaceome is a case in point; OMICS screening in a cell-based system identified that this sub-proteome is largely perturbed in GBM. Additionally, since these cell surface proteins have 'direct' access to drugs, they are appealing targets for cancer therapy. However, a comprehensive GBM surfaceome landscape has not been fully defined yet. Thus, this study aimed to define GBM-associated surfaceome genes and identify key cell-surface genes that could potentially be developed as novel GBM biomarkers for therapeutic purposes.

    METHODS: We integrated the RNA-Seq data from TCGA GBM (n = 166) and GTEx normal brain cortex (n = 408) databases to identify the significantly dysregulated surfaceome in GBM. This was followed by an integrative analysis that combines transcriptomics, proteomics and protein-protein interaction network data to prioritize the high-confidence GBM surfaceome signature.

    RESULTS: Of the 2381 significantly dysregulated genes in GBM, 395 genes were classified as surfaceome. Via the integrative analysis, we identified 6 high-confidence GBM molecular signature, HLA-DRA, CD44, SLC1A5, EGFR, ITGB2, PTPRJ, which were significantly upregulated in GBM. The expression of these genes was validated in an independent transcriptomics database, which confirmed their upregulated expression in GBM. Importantly, high expression of CD44, PTPRJ and HLA-DRA is significantly associated with poor disease-free survival. Last, using the Drugbank database, we identified several clinically-approved drugs targeting the GBM molecular signature suggesting potential drug repurposing.

    CONCLUSIONS: In summary, we identified and highlighted the key GBM surface-enriched repertoires that could be biologically relevant in supporting GBM pathogenesis. These genes could be further interrogated experimentally in future studies that could lead to efficient diagnostic/prognostic markers or potential treatment options for GBM.

  4. Sattar K, Yusoff MSB, Arifin WN, Yasin MAM, Nor MZM
    Pak J Med Sci, 2021 7 23;37(4):1221-1229.
    PMID: 34290812 DOI: 10.12669/pjms.37.4.4004
    Background and Objectives: Medical Professionalism (MP) establishes the trust between society and doctors. We aimed at finding frequently highlighted qualities of MP in the literature.

    Methods: We searched PubMed and Scopus for attributes of MP, using terms, "Professionalism," "Medical Students," and "Undergraduate Medical Education". We included English language, original research articles with MP attributes from the perspective of undergraduate medical education, any nationality, race, gender, and age range, as the central topic of the article. Papers published from January 1st 1986 to 29th February 2020 were included.

    Results: From 1349 identified articles, finally, 18 were included, authored in 10 countries, collectively contributing to answering the scoping review question. Two themes were identified: (1) Nurturing of MP, 11 (61.11%) out of 18 included articles, highlighted "respect" as the most dominant attribute as it appeared in 6 (54.55%) out of 11 reviews, "communication" 5 (45.45 %) studies and "honesty" and "integrity" 4 (36.36%). (2) Assessment of MP, 7 (38.89%) studies, and majority, 4 (57.14 %) assessed MP using American Board of Internal Medicine's elements of MP, viz, "altruism, accountability, excellence, duty, honor and integrity, respect for others."

    Conclusions: Themes exemplified MP's most discoursed issues. The attributes are frequently used worldwide. MP deliberates as a commitment toward the individual patient, society, and necessitates transforming from its present generic form to more explicit details.

  5. Mohamad SNK, Ramli I, Abdullah LC, Mohamed NH, Islam MS, Ibrahim NA, et al.
    Polymers (Basel), 2021 Jun 02;13(11).
    PMID: 34199389 DOI: 10.3390/polym13111839
    In this work, to fabricate a novel composite consisting of chitosan/poly-lactic acid doped with graphene oxide (CS/PLA-GO), composites were prepared via solution blending method to create various compositions of CS and PLA (90/10, 70/30 and 50/50CS/PLA-GO). Graphene oxide (GO) was added into a PLA solution prior to blending it with chitosan (CS). The surface morphology and structural properties of synthesized composites were characterized using FT-IR, SEM and XRD analysis. The performances of synthesized composites on thermal strength, mechanical strength, water absorption, and microbial activity were also evaluated through standard testing methods. The morphology of 70/30CS/PLA-GO became smoother with the addition of GO due to enhanced interfacial adhesion between CS, PLA and GO. The presence of GO has also improved the miscibility of CS and PLA and has superior properties compared to CS/PLA composites. Moreover, the addition of GO has boosted the thermal stability of the composite, with a significant enhancement of Td and Tg. The highest Td and Tg were accomplished at 389 °C and 76.88 °C, respectively, for the 70/30CS/PLA-GO composite in comparison to the CS and PLA that recorded Td at 272 °C and 325 °C and Tg at 61 °C and 60 °C, respectively. In addition, as reinforcement, GO provided a significant influence on the tensile strength of composites where the tensile modulus showed remarkable improvement compared to pure CS and CS/PLA composites. Furthermore, CS/PLA-GO composites showed excellent water-barrier properties. Among other compositions, 70/30CS/PLA revealed the greatest decrement in water absorption. From the antibacterial results, it was observed that 90/10CS/PLA-GO and 70/30CS/PLA-GO showed an inhibitory effect and had wide inhibition zones which were 8.0 and 8.5 mm, respectively, against bacteria Bacillus Subtillis B29.
  6. Doyan A, Leong CL, Bilad MR, Kurnia KA, Susilawati S, Prayogi S, et al.
    Polymers (Basel), 2021 Jun 08;13(12).
    PMID: 34201192 DOI: 10.3390/polym13121907
    The increasing rate of oil and gas production has contributed to a release of oil/water emulsion or mixtures to the environment, becoming a pressing issue. At the same time, pollution of the toxic cigarette butt has also become a growing concern. This study explored utilization of cigarette butt waste as a source of cellulose acetate-based (CA) polymer to develop a phase inverted membrane for treatment of oil/water emulsion and compare it with commercial polyvinylidene difluoride (PVDF) and polysulfone (PSF). Results show that the CA-based membrane from waste cigarette butt offers an eco-friendly material without compromising the separation efficiency, with a pore size range suitable for oil/water emulsion filtration with the rejection of >94.0%. The CA membrane poses good structural property similar to the established PVDF and PSF membranes with equally asymmetric morphology. It also poses hydrophilicity properties with a contact angle of 74.5°, lower than both PVDF and PSF membranes. The pore size of CA demonstrates that the CA is within the microfiltration range with a mean flow pore size of 0.17 µm. The developed CA membrane shows a promising oil/water emulsion permeability of 180 L m-2 h-1 bar-1 after five filtration cycles. However, it still suffers a high degree of irreversible fouling (>90.0%), suggesting potential future improvements in terms of membrane fouling management. Overall, this study demonstrates a sustainable approach to addressing oil/water emulsion pollution treated CA membrane from cigarette butt waste.
  7. Abu Bakar N, Lau Yii Chung B, Smykla J, Karsani SA, Alias SA
    Environ Microbiol, 2021 Sep 16.
    PMID: 34528369 DOI: 10.1111/1462-2920.15776
    Proteome changes can be used as an instrument to measure the effects of climate change, predict the possible future state of an ecosystem and the direction in which is headed. In this study, proteomic and GO functional enrichment analysis of six Pseudogymnoascus spp. isolated from various global biogeographical regions were carried out to determine their response to heat stress. In total, 2,122 proteins were identified with high confidence. Comparative quantitative analysis showed that changes in proteome profiles varied greatly between isolates from different biogeographical regions. Although the identities of the proteins that changed varied between the different regions, the functions they governed were similar. Gene Ontology analysis showed enrichment of proteins involved in multiple protective mechanisms, including the modulation of protein homeostasis, regulation of energy production, and activation of DNA damage and repair pathways. Our proteomic analysis did not show any clear relationship between protein changes and the strains' biogeographical origins. This article is protected by copyright. All rights reserved.
  8. Samad MA, Saiman MZ, Abdul Majid N, Karsani SA, Yaacob JS
    Molecules, 2021 Jan 13;26(2).
    PMID: 33450878 DOI: 10.3390/molecules26020376
    Colorectal cancer (CRC) is the most common cancer among males and females, which is associated with the increment of telomerase level and activity. Some plant-derived compounds are telomerase inhibitors that have the potential to decrease telomerase activity and/or level in various cancer cell lines. Unfortunately, a deeper understanding of the effects of telomerase inhibitor compound(s) on CRC cells is still lacking. Therefore, in this study, the aspects of telomerase inhibitors on a CRC cell line (HCT 116) were investigated. Screening on HCT 116 at 48 h showed that berberine (10.30 ± 0.89 µg/mL) is the most effective (lowest IC50 value) telomerase inhibitor compared to boldine (37.87 ± 3.12 µg/mL) and silymarin (>200 µg/mL). Further analyses exhibited that berberine treatment caused G0/G1 phase arrest at 48 h due to high cyclin D1 (CCND1) and low cyclin-dependent kinase 4 (CDK4) protein and mRNA levels, simultaneous downregulation of human telomerase reverse transcriptase (TERT) mRNA and human telomerase RNA component (TERC) levels, as well as a decrease in the TERT protein level and telomerase activity. The effect of berberine treatment on the cell cycle was time dependent as it resulted in a delayed cell cycle and doubling time by 2.18-fold. Telomerase activity and level was significantly decreased, and telomere erosion followed suit. In summary, our findings suggested that berberine could decrease telomerase activity and level of HCT 116, which in turn inhibits the proliferative ability of the cells.
  9. Syafruddin SE, Mohtar MA, Wan Mohamad Nazarie WF, Low TY
    Biomolecules, 2020 09 28;10(10).
    PMID: 32998281 DOI: 10.3390/biom10101378
    The Krüppel-like factors (KLFs) family of proteins control several key biological processes that include proliferation, differentiation, metabolism, apoptosis and inflammation. Dysregulation of KLF functions have been shown to disrupt cellular homeostasis and contribute to disease development. KLF6 is a relevant example; a range of functional and expression assays suggested that the dysregulation of KLF6 contributes to the onset of cancer, inflammation-associated diseases as well as cardiovascular diseases. KLF6 expression is either suppressed or elevated depending on the disease, and this is largely due to alternative splicing events producing KLF6 isoforms with specialised functions. Hence, the aim of this review is to discuss the known aspects of KLF6 biology that covers the gene and protein architecture, gene regulation, post-translational modifications and functions of KLF6 in health and diseases. We put special emphasis on the equivocal roles of its full-length and spliced variants. We also deliberate on the therapeutic strategies of KLF6 and its associated signalling pathways. Finally, we provide compelling basic and clinical questions to enhance the knowledge and research on elucidating the roles of KLF6 in physiological and pathophysiological processes.
  10. Noorsal E, Arof S, Yahaya SZ, Hussain Z, Kho D, Mohd Ali Y
    Micromachines (Basel), 2021 Aug 16;12(8).
    PMID: 34442590 DOI: 10.3390/mi12080968
    Functional electrical stimulation (FES) device has been widely used by spinal cord injury (SCI) patients in their rehab exercises to restore motor function to their paralysed muscles. The major challenge of muscle contraction induced by FES is early muscle fatigue due to the open-loop stimulation strategy. To reduce the early muscle fatigue phenomenon, a closed-loop FES system is proposed to track the angle of the limb's movement and provide an accurate amount of charge according to the desired reference angle. Among the existing feedback controllers, fuzzy logic controller (FLC) has been found to exhibit good control performance in handling complex non-linear systems without developing any complex mathematical model. Recently, there has been considerable interest in the implementation of FLC in hardware embedded systems. Therefore, in this paper, a digital fuzzy feedback controller (FFC) embedded in a field-programmable gate array (FPGA) board was proposed. The digital FFC mainly consists of an analog-to-digital converter (ADC) Data Acquisition and FLC sub-modules. The FFC was designed to monitor and control the progress of knee extension movement by regulating the stimulus pulse width duration to meet the target angle. The knee is expected to extend to a maximum reference angle setting (70°, 40° or 30°) from its normal position of 0° once the stimulus charge is applied to the muscle by the FES device. Initially, the FLC was modelled using MATLAB Simulink. Then, the FLC was hardcoded into digital logic using hardware description language (HDL) Verilog codes. Thereafter, the performance of the digital FLC was tested with a knee extension model using the HDL co-simulation technique in MATLAB Simulink. Finally, for real-time verification, the designed digital FFC was downloaded to the Intel FPGA (DE2-115) board. The digital FFC utilized only 4% of the total FPGA (Cyclone IV E) logic elements (LEs) and required 238 µs to regulate stimulus pulse width data, including 3 µs for the FLC computation. The high processing speed of the digital FFC enables the stimulus pulse width duration to be updated every stimulation cycle. Furthermore, the implemented digital FFC has demonstrated good control performance in accurately controlling the stimulus pulse width duration to reach the desired reference angle with very small overshoot (1.4°) and steady-state error (0.4°). These promising results are very useful for a real-world closed-loop FES application.
  11. Syed Musa SMS, Md Noorani MS, Abdul Razak F, Ismail M, Alias MA, Hussain SI
    Sci Rep, 2021 03 31;11(1):7234.
    PMID: 33790391 DOI: 10.1038/s41598-021-86739-5
    Flood early warning systems (FLEWSs) contribute remarkably to reducing economic and life losses during a flood. The theory of critical slowing down (CSD) has been successfully used as a generic indicator of early warning signals in various fields. A new tool called persistent homology (PH) was recently introduced for data analysis. PH employs a qualitative approach to assess a data set and provide new information on the topological features of the data set. In the present paper, we propose the use of PH as a preprocessing step to achieve a FLEWS through CSD. We test our proposal on water level data of the Kelantan River, which tends to flood nearly every year. The results suggest that the new information obtained by PH exhibits CSD and, therefore, can be used as a signal for a FLEWS. Further analysis of the signal, we manage to establish an early warning signal for ten of the twelve flood events recorded in the river; the two other events are detected on the first day of the flood. Finally, we compare our results with those of a FLEWS constructed directly from water level data and find that FLEWS via PH creates fewer false alarms than the conventional technique.
  12. Fazil FN, Azzimi NS, Yahaya BH, Kamalaldin NA, Zubairi SI
    ScientificWorldJournal, 2016;2016:7370536.
    PMID: 28105464 DOI: 10.1155/2016/7370536
    Clinacanthus nutans is widely grown in tropical Asia and locally known "belalai gajah" or Sabah snake grass. It has been used as a natural product to treat skin rashes, snake bites, lesion caused by herpes, diabetes, fever, and cancer. Therefore, the objectives of this research are to determine the maximum yield and time of exhaustive flavonoids extraction using Peleg's model and to evaluate potential of antiproliferative activity on human lung cancer cell (A549). The extraction process was carried out on fresh and dried leaves at 28 to 30°C with liquid-to-solid ratio of 10 mL/g for 72 hrs. The extracts were collected intermittently analysed using mathematical Peleg's model and RP-HPLC. The highest amount of flavonoids was used to evaluate the inhibitory concentration (IC50) via 2D cell culture of A549. Based on the results obtained, the predicted maximum extract density was observed at 29.20 ± 14.54 hrs of extraction (texhaustive). However, the exhaustive time of extraction to acquire maximum flavonoids content exhibited approximately 10 hrs earlier. Therefore, 18 hrs of extraction time was chosen to acquire high content of flavonoids. The best antiproliferative effect (IC50) on A549 cell line was observed at 138.82 ± 0.60 µg/mL. In conclusion, the flavonoids content in Clinacanthus nutans water extract possesses potential antiproliferative properties against A549, suggesting an alternative approach for cancer treatment.
  13. Mat Pa MN, Ab Rahman A, Abdul Rahim AF, Yusoff MSB, Yaacob NA
    MyJurnal
    The community placement programme was first introduced to our medical students in 2007. The objectives of this community service programme are to enable students to explore and understand the importance of various skills such as leadership, teamwork and interest towards community services, as well as to improve their skills in those areas for becoming better students and future doctors. The first year medical students were tasked to plan, organize and implement activities in selected communities such as disabled people, orphans, neglected elderly, the poor, HIV positive single mothers and children. Amongst the activities conducted were sharing experiences and thoughts, games, donation and ‘gotong-royong’. The objective of this study was to evaluate the students’ perception on the successfulness of the community placement programme in building their professional qualities. A cross-sectional study was conducted among the first year medical students using a self-administered questionnaire. The questionnaire consists of 5 elements of professional qualities such as leadership and team work skills, interest towards community services, volunteerism and empathy. Self-reflection sessions were also held to explore the learning points gained. A total of 147 students answered the questionnaires. The students rated the overall programme as highly useful (80.6%) and as achieving the objectives (80.1%). They perceived that this programme helped them to improve their personal and professional skills such as leadership (70.0%), team work (71.4%), interest towards community services (87.1%), volunteerism (85.0%), and empathy (89.1%). Self-reflection revealed that the programme made them realize the role of doctors in a community, appreciate the spirit of teamwork and helped them to understand the need of vulnerable groups. As a conclusion, this programme was well-accepted and perceived as assisting medical students to build professional qualities to become caring and competent doctors.
  14. Yahaya SN, Wahab SFA, Yusoff MSB, Yasin MAM, Rahman MAA
    World J Emerg Med, 2018;9(3):178-186.
    PMID: 29796141 DOI: 10.5847/wjem.j.1920-8642.2018.03.003
    BACKGROUND: Demanding profession has been associated with poor psychological health due to multiple factors such as overworking hours and night shifts. This study is to determine prevalence and associated factors of depression, anxiety and stress among medical officers working at emergency department in Malaysian hospitals.

    METHODS: A cross-sectional study was conducted on 140 emergency department medical officers working at general hospitals from seven Malaysia regions. They were randomly selected and their depression, anxiety and stress level were measured by the 21-item Depression, Anxiety, Stress Scale.

    RESULTS: The highest prevalence was anxiety (28.6%) followed by depression (10.7%) and stress (7.9%). Depression, anxiety and stress between seven hospitals were not significantly different (P>0.05). Male medical officers significantly experienced more anxiety symptoms than female medical officers (P=0.0022), however depression and stress symptoms between male and female medical officers were not significantly different (P>0.05). Depression, anxiety and stress were not associated with age, working experience, ethnicity, marital status, number of shifts and type of system adopted in different hospitals (P>0.05).

    CONCLUSION: The prevalence of anxiety was high, whereas for depression and stress were considerably low. Gender was the only factor significantly associated with anxiety. Other factors were not associated with depression, anxiety and stress. Future research should aim to gain better understanding on unique factors that affect female and male medical officers' anxiety level in emergency setting, thus guide authorities to chart strategic plans to remedy this condition.

  15. Johari SA, Mohtar M, Syed Mohamad SA, Mohammat MF, Sahdan R, Mohamed A, et al.
    Biomed Res Int, 2017;2017:8032865.
    PMID: 28536702 DOI: 10.1155/2017/8032865
    Previously we have discovered a synthetically derived pyrrolidone alkaloid, MFM501, exhibiting good inhibitory activity against 53 MRSA and MSSA isolates with low cytotoxicity against three normal cell-lines with IC50 values at >625 µg/ml. Time-kill assay, scanning electron microscopy (SEM) analysis, in vivo oral acute toxicity test, and mice peritonitis model were carried out in this study. In the time-kill study, MFM501 showed a less than 3 log10 decrease in bacterial colony concentration value (CFU/ml) which represented a bacteriostatic action while displaying a time-dependent inhibitory mechanism. Following that, SEM analysis suggested that MFM501 may exert its inhibitory activity via cytoplasmic membrane disruption. Moreover, MFM501 showed no toxicity effect on treated mice at an estimated median acute lethal dose (LD50) value of more than 300 mg/kg and less than 2000 mg/kg. For the efficacy test, a mean effective dose (ED50) of 87.16 mg/kg was obtained via a single dose oral administration. Our data demonstrated that MFM501 has the potential to be developed further as a new, safe, and effective oral-delivered antibacterial agent against MRSA isolates.
  16. Md Sani SS, Han WH, Bujang MA, Ding HJ, Ng KL, Amir Shariffuddin MA
    BMC Infect Dis, 2017 07 21;17(1):505.
    PMID: 28732476 DOI: 10.1186/s12879-017-2601-8
    BACKGROUND: Existing biomarkers such as AST, ALT and hematocrit have been associated with severe dengue but evidence are mixed. Recently, interests in creatine kinase as a dengue biomarker have risen. These biomarkers represent several underlying pathophysiological processes in dengue. Hence, we aimed to assess AST, ALT, CK and hematocrit in identification of severe dengue and to assess the correlational relationship amongst common biomarkers of dengue.

    METHODS: This was a retrospective cohort study of confirmed dengue patients who were warded in Kuala Lumpur Hospital between December 2014 and January 2015. CK, AST, ALT, hematocrit, platelet count, WBC and serum albumin were taken upon ward admission and repeated at timed intervals. Composite indices based on admission AST and ALT were analyzed. Correlation coefficients and coefficients of determination were computed.

    RESULTS: Among the 365 cases reviewed, twenty-two (6%) patients had severe dengue. AST and ALT were found to be good at identification of severe dengue. The AST2/ALT composite index was the most accurate (AUC 0.83; 95% CI 0.73 - 0.93). Optimal cutoff was 402 with a sensitivity of 59.1% (95% CI: 36.4 - 79.3%) and specificity of 92.4% (95% CI: 89.1 - 95.0%). Modified cutoff of 653 had a sensitivity of 40.9% (95% CI: 20.7 - 63.7%) and specificity of 97.4% (95% CI: 95.1 - 98.8%). Our analyses also suggested that several underlying biological processes represented by biomarkers tested were unrelated despite occurring in the same disease entity. Also, markers of plasma leakage were discordant and AST was likely hepatic in origin.

    CONCLUSIONS: The composite index AST2/ALT may be used as a marker for identification of severe dengue based on admission AST and ALT, with two choices of cutoff values, 402 and 653. AST is most likely of liver origin and CK does not provide additional value.

  17. Mohan D, Sajab MS, Kaco H, Bakarudin SB, Noor AM
    Nanomaterials (Basel), 2019 Dec 03;9(12).
    PMID: 31817002 DOI: 10.3390/nano9121726
    The recognition of nanocellulose has been prominent in recent years as prospect materials, yet the ineffectiveness of nanocellulose to disperse in an organic solvent has restricted its utilization, especially as a reinforcement in polymer nanocomposite. In this study, cellulose has been isolated and defibrillated as cellulose nanofibrils (CNF) from oil palm empty fruit bunch (EFB) fibers. Subsequently, to enhance its compatibility with UV-curable polyurethane (PU)-based resin, the surface hydrophilicity of CNF has been tailored with polyethylene glycol (PEG), as well as reduced graphene oxide (rGO). The dispersibility of reinforced modified CNF in UV-curable PU was examined through the transmittance interruption of resin, chemical, and mechanical properties of the composite printed using the stereolithographic technique. Evidently, the enhanced compatibility of modified CNF and UV-curable PU was shown to improve the tensile strength and hardness of the composites by 37% and 129%, respectively.
  18. Khalil M, Aulia G, Budianto E, Mohamed Jan B, Habib SH, Amir Z, et al.
    ACS Omega, 2019 Dec 17;4(25):21477-21486.
    PMID: 31867543 DOI: 10.1021/acsomega.9b03174
    Superparamagnetic nanoparticles (SPNs) have been considered as one of the most studied nanomaterials for subsurface applications, including in enhanced oil recovery (EOR), due to their unique physicochemical properties. However, a comprehensive understanding of the effect of surface functionalization on the ability of the nanoparticles to improve secondary and tertiary oil recoveries remains unclear. Therefore, investigations on the application of bare and surface-functionalized SPNs in EOR using a sand pack were carried out in this study. Here, the as-prepared SPNs were functionalized using oleic acid (OA) and polyacrylamide (PAM) to obtain several types of nanostructure architectures such as OA-SPN, core-shell SPN@PAM, and SPN-PAM. Based on the result, it is found that both the viscosity and mobility of the nanofluids were significantly affected by not only the concentration of the nanoparticles but also the type and architecture of the surface modifier, which dictated particle hydrophilicity. According to the sand pack tests, the nanofluid containing SPN-PAM was able to recover as much as 19.28% of additional oil in a relatively low concentration (0.9% w/v). The high oil recovery enhancement was presumably due to the ability of suspended SPN-PAM to act as a mobility control and wettability alteration agent and facilitate the formation of a Pickering emulsion and disjoining pressure.
  19. Mohamad N, Ubaidillah, Mazlan SA, Choi SB, Abdul Aziz SA, Sugimoto M
    Int J Mol Sci, 2019 Mar 27;20(7).
    PMID: 30934679 DOI: 10.3390/ijms20071525
    The transient response of magnetorheological (MR) materials, in general, is very important for design consideration in MR-based devices. Better response to magnetic fields is beneficial for a better response rate to the electrical current applied in the electromagnetic coil. As a result, MR-based devices would have a high response to external stimuli. In this work, the principal characteristics of magnetorheological greases (MRGs) which have two different particle shapes are experimentally investigated. One type of particle distributed in the grease medium is conventional spherical-shaped carbonyl iron (CI) particles, while the other is plate-like CI particles made using a high-energy rotary ball mill from spherical CI particles. A set of bidisperse MRG samples are firstly prepared by adjusting the weight percentage of the plate-like CI particles and mixing with the spherical CI particles. Subsequently, three important properties of MRGs in terms of their practical application are measured and compared between the two different particle shapes. The field-dependent apparent viscoelastic properties of the prepared MRG samples are measured, followed by the field-dependent storage and loss moduli using an oscillatory shear rheometer. In addition, the transient response time, which indicates the speed in the actuating period of MRGs, is measured by changing the strain amplitude. Then, a comparative assessment on the three properties are undertaken between two different particle shapes by presenting the corresponding results in the same plot. It is shown that the bidisperse MRG with plate-like CI particles exhibits an increase in the initial apparent viscosity as well as stiffness property compared to the MRG with spherical particles only.
  20. Yunus NA, Mazlan SA, Ubaidillah, Abdul Aziz SA, Tan Shilan S, Abdul Wahab NA
    Int J Mol Sci, 2019 Feb 10;20(3).
    PMID: 30744210 DOI: 10.3390/ijms20030746
    Determination of the thermal characteristics and temperature-dependent rheological properties of the magnetorheological elastomers (MREs) is of paramount importance particularly with regards to MRE applications. Hitherto, a paucity of temperature dependent analysis has been conducted by MRE researchers. In this study, an investigation on the thermal and rheological properties of epoxidized natural rubber (ENR)-based MREs was performed. Various percentages of carbonyl iron particles (CIPs) were blended with the ENR compound using a two roll-mill for the preparation of the ENR-based MRE samples. The morphological, elemental, and thermal analyses were performed before the rheological test. Several characterizations, as well as the effects of the strain amplitude, temperature, and magnetic field on the rheological properties of ENR-based MRE samples, were evaluated. The micrographs and elemental results were well-correlated regarding the CIP and Fe contents, and a uniform distribution of CIPs was achieved. The results of the thermal test indicated that the incorporation of CIPs enhanced the thermal stability of the ENR-based MREs. Based on the rheological analysis, the storage modulus and loss factor were dependent on the CIP content and strain amplitude. The effect of temperature on the rheological properties revealed that the stiffness of the ENR-based MREs was considered stable, and they were appropriate to be employed in the MRE devices exposed to high temperatures above 45 °C.
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