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  1. Biomechanical evaluation of three different configurations of external fixators for treating distal third tibia fracture: Finite element analysis in axial, bending and torsion load
    Abdul Wahab AH, Wui NB, Abdul Kadir MR, Ramlee MH
    Comput Biol Med, 2020 12;127:104062.
    PMID: 33096298 DOI: 10.1016/j.compbiomed.2020.104062
    External fixators have been widely used in treating open fractures and have produced excellent outcomes, as they could successfully heal bones. The stability of external fixators lies greatly in their construction. Factors that associated with the stability of the external fixators includes stress, displacement, and relative micromotion. Three-dimensional (3D) models of bone and external fixators were constructed by using 3D modelling software, namely Materialise and SolidWorks, respectively. Three different configurations of external fixators namely Model 1, Model 2, and Model 3 were analysed. Three load cases were simulated to assess the abovementioned factors at the bone, specifically at the fracture site and at the external fixator. Findings showed that the double-cross configuration (Model 3) was the most promising in axial, bending, and torsion load cases as compared to the other two configurations. The no-cross configuration (Model 1) had the highest risk of complication due to high stress, relative micromotion, and displacement in the bending and torsion load cases. On the other hand, the single-cross configuration (Model 2) had the highest risk of complication when applied with axial load. In conclusion, the double-cross locking construct (Model 3) showed the biggest potential to be a new option for medical surgeons in treating patients associated with bone fracture. This new double-cross locking construct showed superior biomechanical stability as compared to single-cross and no-cross configurations in the axial, bending, and torsion load cases.
  2. Biomechanical analysis of three different types of fixators for anterior cruciate ligament reconstruction via finite element method: a patient-specific study
    Zainal Abidin NA, Abdul Wahab AH, Abdul Rahim RA, Abdul Kadir MR, Ramlee MH
    Med Biol Eng Comput, 2021 Sep;59(9):1945-1960.
    PMID: 34392448 DOI: 10.1007/s11517-021-02419-6
    Complication rates of anterior cruciate ligament reconstruction (ACL-R) were reported to be around 15% although it is a common arthroscopic procedure with good outcomes. Breakage and migration of fixators are still possible even months after surgery. A fixator with optimum stability can minimise those two complications. Factors that affect the stability of a fixator are its configuration, material, and design. Thus, this paper aims to analyse the biomechanical effects of different types of fixators (cross-pin, interference screw, and cortical button) towards the stability of the knee joint after ACL-R. In this study, finite element modelling and analyses of a knee joint attached with double semitendinosus graft and fixators were carried out. Mimics and 3-Matic softwares were used in the development of the knee joint models. Meanwhile, the graft and fixators were designed by using SolidWorks software. Once the meshes of all models were finished in 3-Matic, simulation of the configurations was done using MSC Marc Mentat software. A 100-N anterior tibial load was applied onto the tibia to simulate the anterior drawer test. Based on the findings, cross-pin was found to have optimum stability in terms of stress and strain at the femoral fixation site for better treatment of ACL-R.
  3. A rapid MCM-41 dispersive micro-solid phase extraction coupled with LC/MS/MS for quantification of ketoconazole and voriconazole in biological fluids
    Yahaya N, Sanagi MM, Abd Aziz N, Wan Ibrahim WA, Nur H, Loh SH, et al.
    Biomed Chromatogr, 2017 Feb;31(2).
    PMID: 27474795 DOI: 10.1002/bmc.3803
    A rapid dispersive micro-solid phase extraction (D-μ-SPE) combined with LC/MS/MS method was developed and validated for the determination of ketoconazole and voriconazole in human urine and plasma samples. Synthesized mesoporous silica MCM-41 was used as sorbent in d-μ-SPE of the azole compounds from biological fluids. Important D-μ-SPE parameters, namely type desorption solvent, extraction time, sample pH, salt addition, desorption time, amount of sorbent and sample volume were optimized. Liquid chromatographic separations were carried out on a Zorbax SB-C18 column (2.1 × 100 mm, 3.5 μm), using a mobile phase of acetonitrile-0.05% formic acid in 5 mm ammonium acetate buffer (70:30, v/v). A triple quadrupole mass spectrometer with positive ionization mode was used for the determination of target analytes. Under the optimized conditions, the calibration curves showed good linearity in the range of 0.1-10,000 μg/L with satisfactory limit of detection (≤0.06 μg/L) and limit of quantitation (≤0.3 μg/L). The proposed method also showed acceptable intra- and inter-day precisions for ketoconazole and voriconazole from urine and human plasma with RSD ≤16.5% and good relative recoveries in the range 84.3-114.8%. The MCM-41-D-μ-SPE method proved to be rapid and simple and requires a small volume of organic solvent (200 μL); thus it is advantageous for routine drug analysis.
  4. Equilibrium, kinetic and mechanism studies of Cu(II) and Cd(II) ions adsorption by modified chitosan beads
    Sutirman ZA, Sanagi MM, Abd Karim KJ, Wan Ibrahim WA, Jume BH
    Int J Biol Macromol, 2018 Sep;116:255-263.
    PMID: 29746971 DOI: 10.1016/j.ijbiomac.2018.05.031
    In this study, the Cu(II) and Cd(II) ions removal behavior of crosslinked chitosan beads grafted poly(methacrylamide) (abbreviated as crosslinked chitosan-g-PMAm) from single metal ion solutions was investigated. The modified chitosan beads presented a remarkable improvement in acid resistance. The batch experiments demonstrated that pH of solution played a significant role in adsorption. It was found that the adsorption of Cu(II) and Cd(II) were optimum at pH 4 and pH 5, respectively. The maximum adsorption capacities for Cu(II) and Cd(II) based on Langmuir equation were 140.9 mg g-1 and 178.6 mg g-1, respectively. Pseudo-second order gave a better fit for adsorption data with respect to linearity coefficients than pseudo-first order suggesting that chemisorption or electron transfer is the dominant mechanism of the metal ions onto crosslinked chitosan-g-PMAm. In addition, X-ray photoelectron spectroscopy (XPS) investigations revealed that adsorption of both metal ions took place on the surfaces of crosslinked chitosan-g-PMAm by chelation through CNH2, CO and CO groups. Overall, the modified chitosan has proved a promising adsorbent for removal of metal ions.
  5. Elastic constant determination of hardwoods using ultrasonic insertion technique
    Mat Daud AN, Jaafar R, Ayop SK, Yaacob MIH, Rohani MS
    Ultrasonics, 2017 03;75:194-198.
    PMID: 28006660 DOI: 10.1016/j.ultras.2016.11.025
    Ultrasonic insertion technique (IT) is an ultrasonic technique which involves sample immersion in a solution to determine its acoustic properties. IT is normally used to determine the acoustic properties of a medical phantom. We proposed the use of IT as an alternative technique to the common contact ultrasonic technique: through-transmission technique (TT) for determining the elastic constant of hardwoods in longitudinal, tangential and radial directions. The elastic constant of twelve rectangular-shaped Malaysian hardwoods from three different categories; heavy, medium and light with the density ranging from 602 to 992kgm-3 were determined using IT and TT. Both techniques were carried out at 24.0°C surrounding temperature and utilized 2.25MHz ultrasonic transducers. Data from both techniques were compared to validate the use of the proposed technique. Findings indicated that IT offers consistent and accurate results for, tangential and radial elastic constants (TEC and REC) within 8.89% and 5.86% differences, respectively compared to TT for all tested hardwoods. IT offers an alternative technique for TEC and REC determinations of precious wood samples.
  6. Association Between Severity of Obstructive Sleep Apnea and Number and Sites of Upper Airway Operations With Surgery Complications
    Asha'ari ZA, Rahman JA, Mohamed AH, Abdullah K, Leman WI
    JAMA Otolaryngol Head Neck Surg, 2017 03 01;143(3):239-246.
    PMID: 27893073 DOI: 10.1001/jamaoto.2016.3268
    Importance: In patients with obstructive sleep apnea (OSA), operative risks depend on the severity of the underlying OSA and the invasiveness of the surgical procedure.

    Objective: To investigate the nature of the associations between the severity of OSA and the number and anatomical sites of upper airway operations with operative complications.

    Design, Setting, and Participants: This retrospective study included adult patients diagnosed with OSA (apnea-hypopnea index [AHI], >5) who underwent upper airway surgery at a single tertiary referral hospital between October 1, 2008, and October 1, 2015.

    Interventions: All patients underwent single or combination surgery on the nose, palatopharyngeal (tonsils, adenoids, and soft palate), and tongue base as a treatment of OSA.

    Main Outcomes and Measures: Pulmonary, surgical, and cardiovascular complications within the first 30 postoperative days were analyzed according to OSA severity and types of upper airway surgery. Logistic regression was used to assess the multivariable association of OSA, age, sex, body mass index, medical comorbidities, and types of upper airway surgery with short-term operative complications.

    Results: The study included 95 patients (87 males [91.6%]; 83 were Malay [87.4%]; mean [SD] age, 37.7 [1.6] years) with complete data and follow-up who underwent upper airway surgery to treat OSA. Patients with more severe OSA had greater body mass index (Cohen d, 0.27; 95% CI, -0.28 to 0.82), longer surgical time (Cohen d, 1.57; 95% CI, 0.95-2.15), and older age (Cohen d, 3.06; 95% CI, 2.29-3.77). At least 1 operative complication occurred in 48 of 95 patients (51%). In a multivariable model, the overall complication rate was increased with age and body mass index. Complication rates were not associated with AHI severity, type of procedure performed, and whether the surgery was single or combination surgery. Lowest oxygen desaturation (odds ratio, 1.03; 95% CI, 0.96-1.45; P = .04) and longest apnea duration (odds ratio, 1.03; 95% CI, 0.99-1.08; P = .02) were polysomnographic variables that predict the short-term operative complications.

    Conclusions and Relevance: In patients with OSA undergoing upper airway surgery, the severity of OSA as assessed by AHI, and the sites and numbers of concurrent operations performed were not associated with the rate of short-term operative complications.

  7. Fulltext Cycloartane triterpenoid (23R, 24E)-23-acetoxymangiferonic acid inhibited proliferation and migration in B16-F10 melanoma via MITF downregulation caused by inhibition of both β-catenin and c-Raf-MEK1-ERK signaling axis
    Kaneda T, Matsumoto M, Sotozono Y, Fukami S, Nugroho AE, Hirasawa Y, et al.
    J Nat Med, 2019 Jan;73(1):47-58.
    PMID: 30084054 DOI: 10.1007/s11418-018-1233-7
    We recently reported that (23R, 24E)-23-acetoxymangiferonic acid (23R-AMA), a cycloartane triterpenoid isolated by activity-guided separation from a methanol extract of Garcinia sp. bark, inhibited melanin production via inhibition of tyrosinase (TYR) expression in the B16-F10 melanoma cell line. Since 23R-AMA also inhibited microphthalmia-associated transcription factor (MITF) expression, an upstream factor of TYR, these features of 23R-AMA were thought to be appropriate for development of whitening cosmetics. However, 23R-AMA exhibited growth inhibition other than inhibition of melanin production in B16-F10 cells. Therefore, we investigated biological activities of 23R-AMA in detail, focused on its application as an anti-melanoma compound. In this study, we demonstrated that 23R-AMA inhibited cell proliferation and basic FGF (bFGF)-induced migration in B16-F10 cells. Furthermore, 23R-AMA promoted ser45/thr41 phosphorylation of β-catenin and suppressed its intranuclear accumulation, which was suggested to be related to inhibition of MITF expression. The transcriptional activity of MITF is known to be regulated by phosphorylation via activated ERK. Further investigation revealed that 23R-AMA inhibited phosphorylation of c-Raf, MEK-1, and ERK, and also that of upstream molecules including FAK and c-Src. These results suggested that 23R-AMA inhibited growth and migration of B16-F10 melanoma by regulating both MITF expression and its activity. The activities of 23R-AMA reported in this study are new aspects of cycloartane triterpenoids.
  8. Fulltext One-Dimensional-Like Titania/4'-Pentyl-4-Biphenylcarbonitrile Composite Synthesized Under Magnetic Field and its Structure-Photocatalytic Activity Relationship
    Abu Bakar NI, Chandren S, Attan N, Leaw WL, Nur H
    Front Chem, 2018;6:370.
    PMID: 30255010 DOI: 10.3389/fchem.2018.00370
    The demonstration of the structure-properties relationship of shape-dependent photocatalysts remains a challenge today. Herein, one-dimensional (1-D)-like titania (TiO2), as a model photocatalyst, has been synthesized under a strong magnetic field in the presence of a magnetically responsive liquid crystal as the structure-aligning agent to demonstrate the relationship between a well-aligned structure and its photocatalytic properties. The importance of the 1-D-like TiO2 and its relationship with the electronic structures that affect the electron-hole recombination and the photocatalytic activity need to be clarified. The synthesis of 1-D-like TiO2 with liquid crystal as the structure-aligning agent was carried out using the sol-gel method under a magnetic field (0.3 T). The mixture of liquid crystal, 4'-pentyl-4-biphenylcarbonitrile (5CB), tetra-n-butyl orthotitanate (TBOT), 2-propanol, and water, was subjected to slow hydrolysis under a magnetic field. The TiO2-5CB took a well-aligned whiskerlike shape when the reaction mixture was placed under the magnetic field, while irregularly shaped TiO2-5CB particles were formed when no magnetic field was applied. It shows that the strong interaction between 5CB and TBOT during the hydrolysis process under a magnetic field controls the shape of titania. The intensity of the emission peaks in the photoluminescence spectrum of 1-D-like TiO2-5CB was lowered compared with the TiO2-5CB synthesized without the magnetic field, suggesting the occurrence of electron transfer from 5CB to the 1-D-like TiO2-5CB during ultraviolet irradiation. Apart from that, direct current electrical conductivity and Hall effect studies showed that the 1-D-like TiO2 composite enhanced electron mobility. Thus, the recombination of electrons and holes was delayed due to the increase in electron mobility; hence, the photocatalytic activity of the 1-D-like TiO2 composite in the oxidation of styrene in the presence of aqueous hydrogen peroxide under UV irradiation was enhanced. This suggests that the 1-D-like shape of TiO2 composite plays an important role in its photocatalytic activity.
  9. Fulltext Synthesis of Ge1-xSnx Alloy Thin Films by Rapid Thermal Annealing of Sputtered Ge/Sn/Ge Layers on Si Substrates
    Mahmodi H, Hashim MR, Soga T, Alrokayan S, Khan HA, Rusop M
    Materials (Basel), 2018 Nov 12;11(11).
    PMID: 30424494 DOI: 10.3390/ma11112248
    In this work, nanocrystalline Ge1-xSnx alloy formation from a rapid thermal annealed Ge/Sn/Ge multilayer has been presented. The multilayer was magnetron sputtered onto the Silicon substrate. This was followed by annealing the layers by rapid thermal annealing, at temperatures of 300 °C, 350 °C, 400 °C, and 450 °C, for 10 s. Then, the effect of thermal annealing on the morphological, structural, and optical characteristics of the synthesized Ge1-xSnx alloys were investigated. The nanocrystalline Ge1-xSnx formation was revealed by high-resolution X-ray diffraction (HR-XRD) measurements, which showed the orientation of (111). Raman results showed that phonon intensities of the Ge-Ge vibrations were improved with an increase in the annealing temperature. The results evidently showed that raising the annealing temperature led to improvements in the crystalline quality of the layers. It was demonstrated that Ge-Sn solid-phase mixing had occurred at a low temperature of 400 °C, which led to the creation of a Ge1-xSnx alloy. In addition, spectral photo-responsivity of a fabricated Ge1-xSnx metal-semiconductor-metal (MSM) photodetector exhibited its extending wavelength into the near-infrared region (820 nm).
  10. Fulltext Space-Time Clustering Characteristics of Tuberculosis in Khyber Pakhtunkhwa Province, Pakistan, 2015-2019
    Ullah S, Daud H, Dass SC, Fanaee-T H, Kausarian H, Khalil A
    Int J Environ Res Public Health, 2020 02 21;17(4).
    PMID: 32098247 DOI: 10.3390/ijerph17041413
    The number of tuberculosis (TB) cases in Pakistan ranks fifth in the world. The National TB Control Program (NTP) has recently reported more than 462,920 TB patients in Khyber Pakhtunkhwa province, Pakistan from 2002 to 2017. This study aims to identify spatial and space-time clusters of TB cases in Khyber Pakhtunkhwa province Pakistan during 2015-2019 to design effective interventions. The spatial and space-time cluster analyses were conducted at the district-level based on the reported TB cases from January 2015 to April 2019 using space-time scan statistics (SaTScan). The most likely spatial and space-time clusters were detected in the northern rural part of the province. Additionally, two districts in the west were detected as the secondary space-time clusters. The most likely space-time cluster shows a tendency of spread toward the neighboring districts in the central part, and the most likely spatial cluster shows a tendency of spread toward the neighboring districts in the south. Most of the space-time clusters were detected at the start of the study period 2015-2016. The potential TB clusters in the remote rural part might be associated to the dry-cool climate and lack of access to the healthcare centers in the remote areas.
  11. Fulltext Correction to: Cycloartane triterpenoid (23R, 24E)-23-acetoxymangiferonic acid inhibited proliferation and migration in B16-F10 melanoma via MITF downregulation caused by inhibition of both β-catenin and c-Raf-MEK1-ERK signaling axis
    Kaneda T, Matsumoto M, Sotozono Y, Fukami S, Nugroho AE, Hirasawa Y, et al.
    J Nat Med, 2020 06;74(3):612.
    PMID: 32274681 DOI: 10.1007/s11418-020-01401-0
    The article Cycloartane triterpenoid (23R, 24E)-23-acetoxymangiferonic acid inhibited proliferation and migration in B16-F10 melanoma via MITF downregulation caused by inhibition of both β-catenin.
  12. Fulltext Public knowledge, attitudes and practices towards COVID-19: A cross-sectional study in Malaysia
    Azlan AA, Hamzah MR, Sern TJ, Ayub SH, Mohamad E
    PLoS One, 2020;15(5):e0233668.
    PMID: 32437434 DOI: 10.1371/journal.pone.0233668
    In an effort to mitigate the outbreak of COVID-19, many countries have imposed drastic lockdown, movement control or shelter in place orders on their residents. The effectiveness of these mitigation measures is highly dependent on cooperation and compliance of all members of society. The knowledge, attitudes and practices people hold toward the disease play an integral role in determining a society's readiness to accept behavioural change measures from health authorities. The aim of this study was to determine the knowledge levels, attitudes and practices toward COVID-19 among the Malaysian public. A cross-sectional online survey of 4,850 Malaysian residents was conducted between 27th March and 3rd April 2020. The survey instrument consisted of demographic characteristics, 13 items on knowledge, 3 items on attitudes and 3 items on practices, modified from a previously published questionnaire on COVID-19. Descriptive statistics, chi-square tests, t-tests and one-way analysis of variance (ANOVA) were conducted. The overall correct rate of the knowledge questionnaire was 80.5%. Most participants held positive attitudes toward the successful control of COVID-19 (83.1%), the ability of Malaysia to conquer the disease (95.9%) and the way the Malaysian government was handling the crisis (89.9%). Most participants were also taking precautions such as avoiding crowds (83.4%) and practising proper hand hygiene (87.8%) in the week before the movement control order started. However, the wearing of face masks was less common (51.2%). This survey is among the first to assess knowledge, attitudes and practice in response to the COVID-19 pandemic in Malaysia. The results highlight the importance of consistent messaging from health authorities and the government as well as the need for tailored health education programs to improve levels of knowledge, attitudes and practices.
  13. Fulltext Hierarchical Structure and Magnetic Behavior of Zn-Doped Magnetite Aqueous Ferrofluids Prepared from Natural Sand for Antibacterial Agents
    Taufiq A, Yuliantika D, Sunaryono S, Saputro RE, Hidayat N, Mufti N, et al.
    An Acad Bras Cienc, 2021;93(4):e20200774.
    PMID: 34705939 DOI: 10.1590/0001-3765202120200774
    This study performs natural sand-based synthesis using the sonochemical route for preparing Zn-doped magnetite nanoparticles. The nanoparticles were dispersed in water as a carrier liquid to form Zn-doped magnetite aqueous ferrofluids. Structural data analysis indicated that the Zn-doped magnetite nanoparticles formed a nanosized spinel structure. With an increase in the Zn content, the lattice parameters of the Zn-doped magnetite nanoparticles tended to increase because Zn2+ has a larger ionic radius than those of Fe3+ and Fe2+. The existence of Zn-O and Fe-O functional groups in tetrahedral and octahedral sites were observed in the wavenumber range of 400-700 cm-1. The primary particles of the Zn-doped magnetite ferrofluids tended to construct chain-like structures with fractal dimensions of 1.2-1.9. The gas-like compression (GMC) plays as a better model than the Langevin theory to fit the saturation magnetization of the ferrofluids. The ferrofluids exhibited a superparamagnetic character, with their magnetization was contributed by aggregation. The Zn-doped magnetite ferrofluids exhibited excellent antibacterial activity against gram-positive and negative bacteria. It is suggested that the presence of the negatively charged surface and the nanoparticle size may contribute to the high antibacterial activity of Zn-doped magnetite ferrofluids and making them potentially suitable for advanced biomedical.
  14. Efficient Synthesis and Characterization of Polyaniline@Aluminium-Succinate Metal-Organic Frameworks Nanocomposite and Its Application for Zn(II) Ion Sensing
    Alsafrani AE, Adeosun WA, Marwani HM, Khan I, Jawaid M, Asiri AM, et al.
    Polymers (Basel), 2021 Sep 30;13(19).
    PMID: 34641198 DOI: 10.3390/polym13193383
    A new class of conductive metal-organic framework (MOF), polyaniline- aluminum succinate (PANI@Al-SA) nanocomposite was prepared by oxidative polymerization of aniline monomer using potassium persulfate as an oxidant. Several analytical techniques such as FTIR, FE-SEM, EDX, XRD, XPS and TGA-DTA were utilized to characterize the obtained MOFs nanocomposite. DC electrical conductivity of polymer-MOFs was determined by four probe method. A bare glassy carbon electrode (GCE) was modified by nafion/PANI@Al-SA, and examined for Zn (II) ion detection. Modified electrode showed improved efficiency by 91.9%. The modified electrode (PANI@Al-SA/nafion/GCE) exhibited good catalytic property and highly selectivity towards Zn(II) ion. A linear dynamic range of 2.8-228.6 µM was obtained with detection limit of LOD 0.59 µM and excellent sensitivity of 7.14 µA µM-1 cm-2. The designed procedure for Zn (II) ion detection in real sample exhibited good stability in terms of repeatability, reproducibility and not affected by likely interferents. Therefore, the developed procedure is promising for quantification of Zn(II) ion in real samples.
  15. Fulltext Neoadjuvant Therapy Using Checkpoint Inhibitors before Radical Cystectomy for Muscle Invasive Bladder Cancer: A Systematic Review
    Shsm H, Fahmy UA, Alhakamy NA, Khairul-Asri MG, Fahmy O
    J Pers Med, 2021 Nov 13;11(11).
    PMID: 34834547 DOI: 10.3390/jpm11111195
    BACKGROUND: Neoadjuvant chemotherapy is the standard of care before radical cystectomy for muscle invasive bladder cancer. Recently, checkpoint inhibitors have been investigated as a neoadjuvant treatment after the reported efficacy of checkpoint inhibitors in metastatic urothelial carcinoma.

    OBJECTIVES: The aim of this systematic review is to investigate the role of checkpoint inhibitors as a neoadjuvant treatment for muscle invasive bladder cancer before radical cystectomy.

    METHODS: Based on the PRISMA statement, a systematic review of the literature was conducted through online databases and the American Society of Clinical Oncology (ASCO) Meeting Library. Suitable publications were subjected to full-text assessment. The primary outcome of this review was to identify the impact of neoadjuvant immunotherapy on the oncological outcomes and survival benefits.

    RESULTS: From the retrieved 254 results, 8 studies including 404 patients were included. Complete response varied between 30% and 50%. Downstaging varied between 50% and 74%. ≥Grade 3 AEs were recorded in 8.6% of patients who received monotherapy with either Atezolizumab or Pembrolizumab. In patients who received combination treatment, the incidence of ≥Grade 3 AEs was 16.3% for chemoimmunotherapy and 36.5% for combined immunotherapy. A total of 373 patients (92%) underwent radical cystectomy. ≥Grade 3 Clavien-Dindo surgical complications were reported in 21.7% of the patients. One-year overall survival (OS) and relapse-free survival (RFS) varied between 81% and 92%, and 70% and 88%, respectively.

    CONCLUSION: The evidence on the use of immune checkpoint inhibitors in the setting of pre-radical cystectomy is quite limited, with noted variability within published trials. Combination with chemotherapy or another checkpoint inhibitor may boost response, although prospective studies with extended follow-up are needed to report on the survival advantages.

  16. Insight into the bioabsorption of Fe-based materials and their current developments in bone applications
    Md Yusop AH, Ulum MF, Al Sakkaf A, Hartanto D, Nur H
    Biotechnol J, 2021 Dec;16(12):e2100255.
    PMID: 34520117 DOI: 10.1002/biot.202100255
    Iron (Fe) and Fe-based materials have been vigorously explored in orthopedic applications in the past decade mainly owing to their promising mechanical properties including high yield strength, elastic modulus and ductility. Nevertheless, their corrosion products and low corrosion kinetics are the major concerns that need to be improved further despite their appealing mechanical strengths. The current studies on porous Fe-based scaffolds show an improved corrosion rate but the in vitro biocompatibility is still problematic in general. Unlike the Mg implants, the biodegradation and bioabsorption of Fe-based implants are still not well described. This vague issue could implicate the development of Fe-based materials as potential medical implants as they have not reached the clinical trial stage yet. Thus, there is a need to understand in-depth the Fe corrosion behavior and its bioabsorption mechanism to facilitate the material design of Fe-based scaffolds and further improve its biocompatibility. This manuscript provides an important insight into the basic bioabsorption of the multi-ranged Fe-based corrosion products with a review of the latest progress on the corrosion & in vitro biocompatibility of porous Fe-based scaffolds together with the remaining challenges and the perspective on the future direction.
  17. Fulltext Intelligent systems for additive manufacturing-based repair in remanufacturing: a systematic review of its potential
    Mad Yusoh SS, Abd Wahab D, Adil Habeeb H, Azman AH
    PeerJ Comput Sci, 2021;7:e808.
    PMID: 34977355 DOI: 10.7717/peerj-cs.808
    The conventional component repair in remanufacturing involves human decision making that is influenced by several factors such as conditions of incoming cores, modes of failure, severity of damage, features and geometric complexities of cores and types of reparation required. Repair can be enhanced through automation using additive manufacturing (AM) technology. Advancements in AM have led to the development of directed energy deposition and laser cladding technology for repair of damaged parts and components. The objective of this systematic literature review is to ascertain how intelligent systems can be integrated into AM-based repair, through artificial intelligence (AI) approaches capable of supporting the nature and process of decision making during repair. The integration of intelligent systems in AM repair is expected to enhance resource utilization and repair efficiency during remanufacturing. Based on a systematic literature review of articles published during 2005-2021, the study analyses the activities of conventional repair in remanufacturing, trends in the applications of AM for repair using the current state-of-the-art technology and how AI has been deployed to facilitate repair. The study concludes with suggestions on research areas and opportunities that will further enhance the automation of component repair during remanufacturing using intelligent AM systems.
  18. Degradation-triggered release from biodegradable metallic surfaces
    Md Yusop AH, Alsakkaf A, Noordin MA, Idris H, Nur H, Szali Januddi F
    J Biomed Mater Res B Appl Biomater, 2021 12;109(12):2184-2198.
    PMID: 33983686 DOI: 10.1002/jbm.b.34866
    This work is dedicated to the investigation of drug-release control by a direct effect of degradation from biodegradable metallic surfaces. Degradation behaviors characterized by surface morphology, immersion, and electrochemical techniques demonstrated that curcumin-coated zinc (c-Zn) had a higher degradation rate compared to curcumin-coated Fe (c-Fe). High anodic dissolution rate due to the higher degradation rate and widely extended groove-like degradation structure of c-Zn propelled a higher curcumin release. On the other hand, a slower curcumin release rate shown by c-Fe scaffolds is ascribed to its lower anodic dissolution and to its pitting degradation regime with relatively smaller pits. These findings illuminate the remarkable advantage of different degradation behaviors of degradable metallic surfaces in directly controlling the drug release without the need for external electrical stimulus.
  19. Fulltext Associations between health literacy and sociodemographic factors: A cross-sectional study in Malaysia utilising the HLS-M-Q18
    Azlan AA, Hamzah MR, Tham JS, Ayub SH, Ahmad AL, Mohamad E
    Int J Environ Res Public Health, 2021 05 02;18(9).
    PMID: 34063294 DOI: 10.3390/ijerph18094860
    Health literacy is progressively seen as an indicator to describe a nation's health status. To improve health literacy, countries need to address health inequalities by examining different social demographic factors across the population. This assessment is crucial to identify and evaluate the strengths and limitations of a country in addressing health issues. By addressing these health inequalities, a country would be better informed to take necessary steps to improve the nation's health literacy. This study examines health literacy levels in Malaysia and analyses socio-demographic factors that are associated with health literacy. A cross-sectional survey was carried out using the HLS-M-Q18 instrument, which was validated for the Malaysian population. Multi-stage random sampling strategy was used in this study, utilising several sampling techniques including quota sampling, cluster sampling, and simple random sampling to allow random data collection. A total of 855 respondents were sampled. Our results showed that there were significant associations between health literacy and age, health status, and health problems. Our findings also suggest that lower health literacy levels were associated with the younger generation. This study's findings have provided baseline data on Malaysians' health literacy and provide evidence showing potential areas of intervention.
  20. Effects of conform, non-conform, and hybrid conformity toward stress distribution at the glenoid implant and cement: A finite element study
    Abdul Wahab AH, Mohamad Azmi NA, Abdul Kadir MR, Md Saad AP
    Int J Artif Organs, 2022 Feb;45(2):200-206.
    PMID: 33645338 DOI: 10.1177/0391398821999391
    Glenoid conformity is one of the important aspects that could contribute to implant stability. However, the optimal conformity is still being debated among the researchers. Therefore, this study aims to analyze the stress distribution of the implant and cement in three types of conformity (conform, non-conform, and hybrid) in three load conditions (central, anterior, and posterior). Glenoid implant and cement were reconstructed using Solidwork software and a 3D model of scapula bone was done using MIMICS software. Constant load, 750 N, was applied at the central, anterior, and posterior region of the glenoid implant which represents average load for daily living activities for elder people, including, walking with a stick and standing up from a chair. The results showed that, during center load, an implant with dual conformity (hybrid) showed the best (Max Stress-3.93 MPa) and well-distributed stress as compared to other conformity (Non-conform-7.21 MPa, Conform-9.38 MPa). While, during eccentric load (anterior and posterior), high stress was located at the anterior and posterior region with respect to the load applied. Cement stress for non-conform and hybrid implant recorded less than 5 MPa, which indicates it had a very low risk to have cement microcracks, whilst, conform implant was exposed to microcrack of the cement. In conclusion, hybrid conformity showed a promising result that could compromise between conform and non-conform implant. However, further enhancement is required for hybrid implants when dealing with eccentric load (anterior and posterior).
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