Displaying publications 61 - 80 of 153 in total

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  1. Khosravi Y, Loke MF, Chua EG, Tay ST, Vadivelu J
    ScientificWorldJournal, 2012;2012:654939.
    PMID: 22792048 DOI: 10.1100/2012/654939
    Carbapenems are the primary choice of treatment for severe Pseudomonas aeruginosa infection. However, the emergence of carbapenem resistance due to the production of metallo-β-lactamases (MBLs) is of global concern. In this study, 90 imipenem- (IPM- or IP-) resistant P. aeruginosa (IRPA) isolates, including 32 previously tested positive and genotyped for MBL genes by PCR, were subjected to double-disk synergy test (DDST), combined disk test (CDT), and imipenem/imipenem-inhibitor (IP/IPI) E-test to evaluate their MBLs detection capability. All three methods were shown to have a sensitivity of 100%. However, DDST was the most specific of the three (96.6%), followed by IP/IPI E-test interpreted based on the single criteria of IP/IPI ≥8 as positive (62.1%), and CDT was the least specific (43.1%). Based on the data from this evaluation, we propose that only IRPA with IP MIC >16 μg/mL and IP/IPI ≥8 by IP/IPI E-test should be taken as positive for MBL activity. With the new dual interpretation criteria, the MBL IP/IPI E-test was shown to achieve 100% sensitivity as well as specificity for the IRPA in this study. Therefore, the IP/IPI E-test is a viable alternative phenotypic assay to detect MBL production in IRPA in our population in circumstances where PCR detection is not a feasible option.
  2. Mariappan V, Vellasamy KM, Thimma JS, Hashim OH, Vadivelu J
    Vaccine, 2010 Feb 3;28(5):1318-24.
    PMID: 19944788 DOI: 10.1016/j.vaccine.2009.11.027
    Burkholderia cepacia is an opportunistic human pathogen associated with lung infections. Secretory proteins of B. cepacia are known to be involved in virulence and may mediate important host-pathogen interactions. In the present study, secretory proteins isolated from B. cepacia culture supernatant were separated using two-dimensional gel electrophoresis, followed by Western blot analysis to identify the immunogenic proteins. Mice antibodies raised to B. cepacia inactivated whole bacteria, outer membrane protein and culture filtrate antigen detected 74, 104 and 32 immunogenic proteins, respectively. Eighteen of these immunogenic proteins which reacted with all three antibodies were identified and might be potential molecules as a diagnostic marker or a putative candidate vaccine against B. cepacia infections.
  3. Appanna R, Huat TL, See LL, Tan PL, Vadivelu J, Devi S
    Clin. Vaccine Immunol., 2007 Aug;14(8):969-77.
    PMID: 17567768
    Dengue virus infections are a major cause of morbidity and mortality in tropical and subtropical areas in the world. Attempts to develop effective vaccines have been hampered by the lack of understanding of the pathogenesis of the disease and the absence of suitable experimental models for dengue viral infection. The magnitude of T-cell responses has been reported to correlate with dengue disease severity. Sixty Malaysian adults with dengue viral infections were investigated for their dengue virus-specific T-cell responses to 32 peptides antigens from the structural and nonstructural regions from a dengue virus isolate. Seventeen different peptides from the C, E, NS2B, NS3, NS4A, NS4B, and NS5 regions were found to evoke significant responses in a gamma interferon enzyme-linked immunospot (ELISPOT) assay of samples from 13 selected patients with dengue fever (DF) and dengue hemorrhagic fever (DHF). NS3 and predominantly NS3(422-431) were found to be important T-cell targets. The highest peaks of T-cell responses observed were in responses to NS3(422-431) and NS5(563-571) in DHF patients. We also found almost a sevenfold increase in T-cell response in three DHF patients compared to three DF patient responses to peptide NS3(422-431). A large number of patients' T cells also responded to the NS2B(97-106) region. The ELISPOT analyses also revealed high frequencies of T cells that recognize both serotype-specific and cross-reactive dengue virus antigens in patients with DHF.
  4. Sim JH, Tong WT, Hong WH, Vadivelu J, Hassan H
    Med Educ Online, 2015;20:28612.
    PMID: 26511792 DOI: 10.3402/meo.v20.28612
    INTRODUCTION: Assessment environment, synonymous with climate or atmosphere, is multifaceted. Although there are valid and reliable instruments for measuring the educational environment, there is no validated instrument for measuring the assessment environment in medical programs. This study aimed to develop an instrument for measuring students' perceptions of the assessment environment in an undergraduate medical program and to examine the psychometric properties of the new instrument.
    METHOD: The Assessment Environment Questionnaire (AEQ), a 40-item, four-point (1=Strongly Disagree to 4=Strongly Agree) Likert scale instrument designed by the authors, was administered to medical undergraduates from the authors' institution. The response rate was 626/794 (78.84%). To establish construct validity, exploratory factor analysis (EFA) with principal component analysis and varimax rotation was conducted. To examine the internal consistency reliability of the instrument, Cronbach's α was computed. Mean scores for the entire AEQ and for each factor/subscale were calculated. Mean AEQ scores of students from different academic years and sex were examined.
    RESULTS: Six hundred and eleven completed questionnaires were analysed. EFA extracted four factors: feedback mechanism (seven items), learning and performance (five items), information on assessment (five items), and assessment system/procedure (three items), which together explained 56.72% of the variance. Based on the four extracted factors/subscales, the AEQ was reduced to 20 items. Cronbach's α for the 20-item AEQ was 0.89, whereas Cronbach's α for the four factors/subscales ranged from 0.71 to 0.87. Mean score for the AEQ was 2.68/4.00. The factor/subscale of 'feedback mechanism' recorded the lowest mean (2.39/4.00), whereas the factor/subscale of 'assessment system/procedure' scored the highest mean (2.92/4.00). Significant differences were found among the AEQ scores of students from different academic years.
    CONCLUSIONS: The AEQ is a valid and reliable instrument. Initial validation supports its use to measure students' perceptions of the assessment environment in an undergraduate medical program.
    KEYWORDS: assessment environment; development; instrument; psychometric properties; validation
  5. Vale FF, Vadivelu J, Oleastro M, Breurec S, Engstrand L, Perets TT, et al.
    Sci Rep, 2015;5:14333.
    PMID: 26387443 DOI: 10.1038/srep14333
    Prophages of Helicobacter pylori, a bacterium known to co-evolve in the stomach of its human host, were recently identified. However, their role in the diversity of H. pylori strains is unknown. We demonstrate here and for the first time that the diversity of the prophage genes offers the ability to distinguish between European populations, and that H. pylori prophages and their host bacteria share a complex evolutionary history. By comparing the phylogenetic trees of two prophage genes (integrase and holin) and the multilocus sequence typing (MLST)-based data obtained for seven housekeeping genes, we observed that the majority of the strains belong to the same phylogeographic group in both trees. Furthermore, we found that the Bayesian analysis of the population structure of the prophage genes identified two H. pylori European populations, hpNEurope and hpSWEurope, while the MLST sequences identified one European population, hpEurope. The population structure analysis of H. pylori prophages was even more discriminative than the traditional MLST-based method for the European population. Prophages are new players to be considered not only to show the diversity of H. pylori strains but also to more sharply define human populations.
  6. See JX, Samudi C, Saeidi A, Menon N, Choh LC, Vadivelu J, et al.
    PLoS Negl Trop Dis, 2016 Mar;10(3):e0004503.
    PMID: 26974441 DOI: 10.1371/journal.pntd.0004503
    Burkholderia pseudomallei (B. pseudomallei), the causative agent of melioidosis, is a deadly pathogen endemic across parts of tropical South East Asia and Northern Australia. B. pseudomallei can remain latent within the intracellular compartment of the host cell over prolonged periods of time, and cause persistent disease leading to treatment difficulties. Understanding the immunological mechanisms behind persistent infection can result in improved treatment strategies in clinical melioidosis.
  7. Khosravi Y, Loke MF, Chua EG, Tay ST, Vadivelu J
    ScientificWorldJournal, 2016;2016:9562039.
    PMID: 27314061
    [This corrects the article DOI: 10.1100/2012/654939.].
  8. Chow TK, Eu LC, Chin KF, Ong KC, Pailoor J, Vadivelu J, et al.
    Am J Trop Med Hyg, 2016 Mar 2;94(3):522-4.
    PMID: 26787155 DOI: 10.4269/ajtmh.15-0774
    We report a rare case of an asymptomatic latent melioidosis lesion in a posttraumatic splenectomy specimen from a diabetic patient. The 2-cm yellowish, lobulated lesion was found in the splenic parenchyma well away from the traumatized areas. Microscopically, it consisted of a central area of necrosis and exudate surrounded by macrophages, epithelioid cells, lymphocytes, and occasional multinucleated giant cells. Burkholderia bacilli were detected by a novel in situ hybridization (ISH) assay, and confirmed by polymerase chain reaction and sequencing to be Burkholderia pseudomallei. As melioidosis was not suspected initially, bacterial culture was not done but electron microscopy showed morphologically viable and dividing bacilli in the lesion. Moreover, the surgical wound became infected with B. pseudomallei several days post-surgery. After treatment with ceftazidime and trimethoprim/sulfamethoxazole, the wound infection cleared. We believe this could be a unique case of asymptomatic latent melioidosis in the spleen. In endemic countries, chronic granulomas should be investigated for B. pseudomallei infection, and if available, ISH may be helpful for diagnosis.
  9. Rafieerad AR, Bushroa AR, Nasiri-Tabrizi B, Fallahpour A, Vadivelu J, Musa SN, et al.
    J Mech Behav Biomed Mater, 2016 08;61:182-196.
    PMID: 26874249 DOI: 10.1016/j.jmbbm.2016.01.028
    PVD process as a thin film coating method is highly applicable for both metallic and ceramic materials, which is faced with the necessity of choosing the correct parameters to achieve optimal results. In the present study, a GEP-based model for the first time was proposed as a safe and accurate method to predict the adhesion strength and hardness of the Nb PVD coated aimed at growing the mixed oxide nanotubular arrays on Ti67. Here, the training and testing analysis were executed for both adhesion strength and hardness. The optimum parameter combination for the scratch adhesion strength and micro hardness was determined by the maximum mean S/N ratio, which was 350W, 20 sccm, and a DC bias of 90V. Results showed that the values calculated in the training and testing in GEP model were very close to the actual experiments designed by Taguchi. The as-sputtered Nb coating with highest adhesion strength and microhardness was electrochemically anodized at 20V for 4h. From the FESEM images and EDS results of the annealed sample, a thick layer of bone-like apatite was formed on the sample surface after soaking in SBF for 10 days, which can be connected to the development of a highly ordered nanotube arrays. This novel approach provides an outline for the future design of nanostructured coatings for a wide range of applications.
  10. Tan GM, Looi CY, Fernandez KC, Vadivelu J, Loke MF, Wong WF
    Sci Rep, 2015;5:11046.
    PMID: 26078204 DOI: 10.1038/srep11046
    Helicobacter pylori at multiplicity of infection (MOI ≥ 50) have been shown to cause apoptosis in RAW264.7 monocytic macrophage cells. Because chronic gastric infection by H. pylori results in the persistence of macrophages in the host's gut, it is likely that H. pylori is present at low to moderate, rather than high numbers in the infected host. At present, the effect of low-MOI H. pylori infection on macrophage has not been fully elucidated. In this study, we investigated the genome-wide transcriptional regulation of H. pylori-infected RAW264.7 cells at MOI 1, 5 and 10 in the absence of cellular apoptosis. Microarray data revealed up- and down-regulation of 1341 and 1591 genes, respectively. The expression of genes encoding for DNA replication and cell cycle-associated molecules, including Aurora-B kinase (AurkB) were down-regulated. Immunoblot analysis verified the decreased expression of AurkB and downstream phosphorylation of Cdk1 caused by H. pylori infection. Consistently, we observed that H. pylori infection inhibited cell proliferation and progression through the G1/S and G2/M checkpoints. In summary, we suggest that H. pylori disrupts expression of cell cycle-associated genes, thereby impeding proliferation of RAW264.7 cells, and such disruption may be an immunoevasive strategy utilized by H. pylori.
  11. Vadivelu J, Puthucheary SD, Mifsud A, Drasar BS, Dance DA, Pitt TI
    Trans R Soc Trop Med Hyg, 1997 5 1;91(3):358-60.
    PMID: 9231217
    Forty-nine isolates of Burkholderia pseudomallei from sporadic cases of melioidosis in Malaysia over the past 18 years were examined by BamHI ribotyping and pulsed-field gel electrophoresis (PFGE) of XbaI digests of total deoxyribonucleic acid (DNA). Twenty-four patients had septicaemic melioidosis with a mortality of 70%; mortality in the non-septicaemic disease was 16%. Five ribotype patterns were identified, 2 of which accounted for 90% of all isolates. PFGE revealed a number of different strains within these ribotypes, but some pairs of isolates from unrelated cases gave closely similar DNA profiles. These results are in agreement with Australian studies which showed a high prevalence of a few ribotypes of B. pseudomallei which are further divisible by genotyping, in areas where melioidosis is endemic.
  12. Vadivelu J, Feachem RG, Drasar BS, Harrison TJ, Parasakthi N, Thambypillai V, et al.
    Epidemiol Infect, 1989 Dec;103(3):497-511.
    PMID: 2691267
    The membrane-filter assay, GM1-ELISA, and DNA-DNA hybridization assay, were used to detect enterotoxigenic Escherichia coli (ETEC) in samples of water, weaning food, food preparation surface swabs, fingerprints of mothers, and the fingerprints and stools of children under 5 years of age, in 20 households in a Malaysian village. Weaning food and environmental samples were frequently contaminated by faecal coliforms, including ETEC. The membrane-filter assay detected and enumerated faecal coliforms and LT-ETEC in all types of water and weaning food samples. Highest concentrations of faecal coliforms and LT-ETEC were found in weaning food, followed by well-water, stored water and stored drinking water. The GM1-ELISA detected LT-ETEC in weaning food, food preparation surfaces, fingerprints and stool samples. The DNA-DNA hybridization assay detected a larger proportion of STa2-ETEC than the other toxotypes, either singly or in combination. All the assays in combination detected the presence of ETEC in all types of samples on at least one occasion in each household. It was not possible to classify households as consistently more or less contaminated with ETEC. On individual occasions it was possible to show a significant association of the presence of LT-ETEC between the fingerprints of children and their stools, fingerprints of mothers and children, and weaning food and the stools of the child consuming the food.
  13. Sidahmed HMA, Vadivelu J, Loke MF, Arbab IA, Abdul B, Sukari MA, et al.
    Phytomedicine, 2019 Mar 01;55:31-39.
    PMID: 30668441 DOI: 10.1016/j.phymed.2018.06.036
    BACKGROUND: Clausena excavata Burm.f. (Rutaceae) has been used for the treatment of stomach disorders including peptic ulcer.

    PURPOSE: In this study, we aimed to investigate dentatin isolated from C. excavata Burm.f., for anti-ulcer activity against ethanol ulcer model in rats.

    METHODS: Gastric acid output, ulcer index, serum profile, histological evaluation using Hematoxylin and eosin (HE), periodic acid Schiff base stainings and immunohistochemical localization for heat shock proteins 70 (HSP70) were all investigated. Possible involvement of reduced glutathione (GSH), lipid peroxidation, prostaglandin E2 (PGE2), superoxide dismutase (SOD) enzymes, radical scavenging, and anti-Helicobacter pylori activity were investigated.

    RESULTS: Dentatin showed anti-secretory activity against the pylorus ligature model and protected the gastric mucosa from ethanol ulceration, as revealed by the improved macroscopic and histological appearance. Dentatin significantly increased the gastric homogenate content of PGE2 GSH and SOD. Dentatin inhibited the lipid peroxidation as revealed by the reduced gastric content of malondialdehyde (MDA). Moreover, dentatin up-regulated HSP70 expression. However, dentatin showed insignificant anti-H. pylori activity.

    CONCLUSION: Dentatin possesses gastro-protective activity, which could be attributed to the anti-secretory, mucus production, anti-oxidant, and HSP70 activities.

  14. Al-Maleki AR, Vellasamy KM, Mariappan V, Venkatraman G, Tay ST, Vadivelu J
    Genomics, 2020 01;112(1):501-512.
    PMID: 30980902 DOI: 10.1016/j.ygeno.2019.04.002
    Differences in expression of potential virulence and survival genes were associated with B. pseudomallei colony morphology variants. Microarray was used to investigate B. pseudomallei transcriptome alterations among the wild type and small colony variant (SCV) pre- and post-exposed to A549 cells. SCV pre- and post-exposed have lower metabolic requirements and consume lesser energy than the wild type pre- and post-exposed to A549. However, both the wild type and SCV limit their metabolic activities post- infection of A549 cells and this is indicated by the down-regulation of genes implicated in the metabolism of amino acids, carbohydrate, lipid, and other amino acids. Many well-known virulence and survival factors, including T3SS, fimbriae, capsular polysaccharides and stress response were up-regulated in both the wild type and SCV pre- and post-exposed to A549 cells. Microarray analysis demonstrated essential differences in bacterial response associated with virulence and survival pre- and post-exposed to A549 cells.
  15. Muthusami S, Vidya B, Shankar EM, Vadivelu J, Ramachandran I, Stanley JA, et al.
    Curr Protein Pept Sci, 2020;21(1):52-65.
    PMID: 31702489 DOI: 10.2174/1389203720666191106113435
    Hormones are known to influence various body systems that include skeletal, cardiac, digestive, excretory, and immune systems. Emerging investigations suggest the key role played by secretions of endocrine glands in immune cell differentiation, proliferation, activation, and memory attributes of the immune system. The link between steroid hormones such as glucocorticoids and inflammation is widely known. However, the role of peptide hormones and amino acid derivatives such as growth and thyroid hormones, prolactin, dopamine, and thymopoietin in regulating the functioning of the immune system remains unclear. Here, we reviewed the findings pertinent to the functional role of hormone-immune interactions in health and disease and proposed perspective directions for translational research in the field.
  16. Barathan M, Zulpa AK, Vellasamy KM, Mariappan V, Shivashekaregowda NKH, Ibrahim ZA, et al.
    In Vivo, 2021 8 20;35(5):2675-2685.
    PMID: 34410956 DOI: 10.21873/invivo.12551
    BACKGROUND/AIM: Isoniazid is an antibiotic used for the treatment of tuberculosis. Previously, we found that the isoniazid derivative (E)-N'-(2,3,4-trihydroxybenzylidene) isonicotinohydrazide (ITHB4) could be developed as novel antimycobacterial agent by lead optimization. We further explored the ability of this compound compared to zerumbone in inhibiting the growth of MCF-7 breast cancer cells.

    MATERIALS AND METHODS: Cytotoxicity was measured by the MTT assay and further confirmed via apoptosis, ROS, cell cycle, DNA fragmentation and cytokine assays.

    RESULTS: ITHB4 demonstrated a lower IC50 compared to zerumbone in inhibiting the proliferation of MCF-7 cells. ITHB4 showed no toxicity against normal breast and human immune cells. Apoptosis assay revealed that ITHB4, at a concentration equal to the IC50, induces apoptosis of MCF-7 cells and cell cycle arrest at the sub-G1 and G2/M phases. ITHB4 triggered accumulation of intracellular ROS and nuclear DNA fragmentation. Secretion of pro-inflammatory cytokines induced inflammation and potentially immunogenic cell death.

    CONCLUSION: ITHB4 has almost similar chemotherapeutic properties as zerumbone in inhibiting MCF-7 growth, and hence provide the basis for further experiments in animal models.

  17. Lee SS, Samarasekera DD, Sim JH, Hong WH, Foong CC, Pallath V, et al.
    Med Sci Educ, 2020 Mar;30(1):271-280.
    PMID: 34457667 DOI: 10.1007/s40670-019-00894-z
    Purpose: Research has shown that many undergraduate students struggle with self-regulated learning (SRL) in clinical year as they are insufficiently supported by the staff in the early year to prepare them for the transition. Hence, this study aims to find out the SRL strategies and the approaches that could promote SRL among pre-clinical students in two medical schools.

    Method: This is a mixed-method study. The Motivated Strategies for Learning Questionnaire (MSLQ) was used to collect student SRL strategies while semi-structured interviews with faculty members and focus group discussions with students were used to gather data on the approaches that promote SRL. Student MSLQ was analysed using descriptive statistics while interviews were transcribed verbatim and thematically analysed.

    Results: A pilot using MSLQ with 413 students recorded a Cronbach's alpha of 0.928 for the questionnaire. The actual study involved 457 Years 1 & 2 students. Students from both institutions are motivated by the Task Value, and they use Elaboration and Organisation strategies the most in their pre-clinical year. Three themes emerged from the qualitative analysis of this study: characteristics of strategies that promote SRL, hindrance in promoting SRL, and opportunities in promoting SRL.

    Conclusions: Our findings indicate that students' intrinsic motivation is generally high in pre-clinical year. However, metacognition and critical thinking strategies will need to be enhanced among students. Despite knowing teaching and learning approaches could promote these strategies, many teachers are still not confident in doing so and hence training dang sharing best practices might be helpful in promoting SRL.

  18. Mariappan V, Vellasamy KM, Barathan M, Girija ASS, Shankar EM, Vadivelu J
    Front Immunol, 2021;12:718719.
    PMID: 34456925 DOI: 10.3389/fimmu.2021.718719
    Burkholderia pseudomallei (B. pseudomallei) causes melioidosis, a potentially fatal disease for which no licensed vaccine is available thus far. The host-pathogen interactions in B. pseudomallei infection largely remain the tip of the iceberg. The pathological manifestations are protean ranging from acute to chronic involving one or more visceral organs leading to septic shock, especially in individuals with underlying conditions similar to COVID-19. Pathogenesis is attributed to the intracellular ability of the bacterium to 'step into' the host cell's cytoplasm from the endocytotic vacuole, where it appears to polymerize actin filaments to spread across cells in the closer vicinity. B. pseudomallei effectively evades the host's surveillance armory to remain latent for prolonged duration also causing relapses despite antimicrobial therapy. Therefore, eradication of intracellular B. pseudomallei is highly dependent on robust cellular immune responses. However, it remains ambiguous why certain individuals in endemic areas experience asymptomatic seroconversion, whereas others succumb to sepsis-associated sequelae. Here, we propose key insights on how the host's surveillance radars get commandeered by B. pseudomallei.
  19. Guang-Han O, Leang-Chung C, Vellasamy KM, Mariappan V, Li-Yen C, Vadivelu J
    PLoS One, 2016;11(7):e0158213.
    PMID: 27387381 DOI: 10.1371/journal.pone.0158213
    Burkholderia pseudomallei is an intracellular Gram-negative bacterial pathogen intrinsically resistant to a variety of antibiotics. Phages have been developed for use as an alternative treatment therapy, particularly for bacterial infections that do not respond to conventional antibiotics. In this study, we investigated the use of phages to treat cells infected with B. pseudomallei. Phage C34 isolated from seawater was purified and characterised on the basis of its host range and morphology using transmission electron microscopy (TEM). Phage C34 was able to lyse 39.5% of B. pseudomallei clinical strains. Due to the presence of contractile tail, phage C34 is classified as a member of the family Myoviridae, a tailed double-stranded DNA virus. When 2 × 105 A549 cells were exposed to 2 × 107 PFU of phage C34, 24 hours prior to infection with 2 × 106 CFU of B. pseudomallei, it was found that the survivability of the cells increased to 41.6 ± 6.8% as compared to 22.8 ± 6.0% in untreated control. Additionally, application of phage successfully rescued 33.3% of mice infected with B. pseudomallei and significantly reduced the bacterial load in the spleen of the phage-treated mice. These findings indicate that phage can be a potential antimicrobial agent for B. pseudomallei infections.
  20. Rafieerad AR, Bushroa AR, Nasiri-Tabrizi B, Kaboli SHA, Khanahmadi S, Amiri A, et al.
    J Mech Behav Biomed Mater, 2017 May;69:1-18.
    PMID: 28027481 DOI: 10.1016/j.jmbbm.2016.11.019
    Recently, the robust optimization and prediction models have been highly noticed in district of surface engineering and coating techniques to obtain the highest possible output values through least trial and error experiments. Besides, due to necessity of finding the optimum value of dependent variables, the multi-objective metaheuristic models have been proposed to optimize various processes. Herein, oriented mixed oxide nanotubular arrays were grown on Ti-6Al-7Nb (Ti67) implant using physical vapor deposition magnetron sputtering (PVDMS) designed by Taguchi and following electrochemical anodization. The obtained adhesion strength and hardness of Ti67/Nb were modeled by particle swarm optimization (PSO) to predict the outputs performance. According to developed models, multi-objective PSO (MOPSO) run aimed at finding PVDMS inputs to maximize current outputs simultaneously. The provided sputtering parameters were applied as validation experiment and resulted in higher adhesion strength and hardness of interfaced layer with Ti67. The as-deposited Nb layer before and after optimization were anodized in fluoride-base electrolyte for 300min. To crystallize the coatings, the anodically grown mixed oxide TiO2-Nb2O5-Al2O3 nanotubes were annealed at 440°C for 30min. From the FESEM observations, the optimized adhesive Nb interlayer led to further homogeneity of mixed nanotube arrays. As a result of this surface modification, the anodized sample after annealing showed the highest mechanical, tribological, corrosion resistant and in-vitro bioactivity properties, where a thick bone-like apatite layer was formed on the mixed oxide nanotubes surface within 10 days immersion in simulated body fluid (SBF) after applied MOPSO. The novel results of this study can be effective in optimizing a variety of the surface properties of the nanostructured implants.
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