19672 research outputs found
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Performance impact of relay selection in WiMAX IEEE 802.16j multi-hop relay networks
No full textWorldwide Interoperability for Microwave Access network accepts the challenge of last mile wireless access for internet. IEEE 802.16 standard, commercially known as WiMAX provide wireless broadband experience to the end subscribers and challenges many wired solutions like Digital Subscriber Line (DSL) and cable internet. Wireless network has many inherent issues like coverage holes; capacity optimization and mobility are few of them. Adding relays to multi-hop WiMAX IEEE 802.16j network present an effective solution to address them to some extent but this amendment does not elaborate any algorithm regarding the relay selection and narrate no performance guarantees. In this work, we proposed linear model that fairly allocates wireless resources among subscribers in 802.16j network. A relay selection algorithm is also presented to optimally select nodes with higher signal-to-noise ratio as relay station for nodes with lower signal-to-noise ratio objectively maximize overall network capacity. This scheme further extends network coverage area and improves network availability. We also did extensive performance evaluation of the proposed linear model. Results show that optimal relays selection scheme do provide a substantial increase of up to 66% in overall network capacity in the fixed WiMAX network. This improvement is substantial at places where network condition is not optimal. Investigating the problem further leads to the conclusion that the relay selection criterion is the key to achieve maximum network capacity. © 2018 The Science and Information (SAI) Organization Limited
Influence of solution pH on the formation of iron oxide nanoparticles
No full textIron oxide phase orientation were highly influenced by solution pH, crystalline structure, purity, surface enrichment, particle size, and morphology. This paper investigates the influence of pHchanges by varying the precursor anions of chloride (FeCl2) and sulphate (FeSO4) on the formation of iron oxide nanoparticles using one step controlled precipitation technique. The obtained titration curve provided vital information on the reaction mechanism whereby different hydrolysis rate of
precursor leads to different iron oxide phases. It was determined that at pH 4, goethite (α-FeOOH) was obtained. Continuous addition of hydroxyl ions (OH−) then forms iron hydroxides (Fe(OH)2) which will then subsequently react with the goethite precipitating magnetite (Fe3O4) nanoparticles (35–45 nm) atpH 10 with ferromagnetic behavior. By the use of Cl− anion, the slower hydrolysis
process induced requires more hydroxyl ions to reach pHequilibrium leading to larger maghemite nanoparticles (50–60 nm). Spectroscopic analysis via Raman and FTIR analysis confirms the phases obtained. SEM andTEMimaging shows the correlation of structure orientation anisotropy which influenced the magnetic properties. Spherical magnetite nanoparticles strong dipolar interaction have
higher coercivity (117G) and remanence (12 emu g−1) compared to the synthesised maghemite spinel needle-like structure nanoparticles. The understanding of the iron oxide structure directing effect by complex pH solution mechanism was essential for not only to prepare different forms of iron oxide and hydroxides but also controlled synthesis reproducibility
Inhibition of Oncogenic Kinases: An In Vitro Validated Computational Approach Identified Potential Multi-Target Anticancer Compounds
No full textTumorigenesis in humans is a multistep progression that imitates genetic changes leading to cell transformation and malignancy. Oncogenic kinases play a central role in cancer progression, rendering them putative targets for the design of anti-cancer drugs. The presented work aims to identify the potential multi-target inhibitors of oncogenic receptor tyrosine kinases (RTKs) and serine/threonine kinases (STKs). For this, chemoinformatics and structure-based virtual screening approaches were combined with an in vitro validation of lead hits on both cancerous and noncancerous cell lines. A total of 16 different kinase structures were screened against ~739,000 prefiltered compounds using diversity selection, after which the top hits were filtered for promising pharmacokinetic properties. This led to the identification of 12 and 9 compounds against RTKs and STKs, respectively. Molecular dynamics (MD) simulations were carried out to better comprehend the stability of the predicted hit kinase-compound complexes. Two top-ranked compounds against each kinase class were tested in vitro for cytotoxicity, with compound F34 showing the most promising inhibitory activity in HeLa, HepG2, and Vero cell lines with IC50 values of 145.46 μM, 175.48 μM, and 130.52 μM, respectively. Additional docking of F34 against various RTKs was carried out to support potential multi-target inhibition. Together with reliable MD simulations, these results suggest the promising potential of identified multi-target STK and RTK scaffolds for further kinase-specific anti-cancer drug development toward combinatorial therapies. © 2019 by the authors. Licensee MDPI, Basel, Switzerland
Noncoding CGG repeat expansions in neuronal intranuclear inclusion disease, oculopharyngodistal myopathy and an overlapping disease
No full textNoncoding repeat expansions cause various neuromuscular diseases, including myotonic dystrophies, fragile X tremor/ataxia syndrome, some spinocerebellar ataxias, amyotrophic lateral sclerosis and benign adult familial myoclonic epilepsies. Inspired by the striking similarities in the clinical and neuroimaging findings between neuronal intranuclear inclusion disease (NIID) and fragile X tremor/ataxia syndrome caused by noncoding CGG repeat expansions in FMR1, we directly searched for repeat expansion mutations and identified noncoding CGG repeat expansions in NBPF19 (NOTCH2NLC) as the causative mutations for NIID. Further prompted by the similarities in the clinical and neuroimaging findings with NIID, we identified similar noncoding CGG repeat expansions in two other diseases: oculopharyngeal myopathy with leukoencephalopathy and oculopharyngodistal myopathy, in LOC642361/NUTM2B-AS1 and LRP12, respectively. These findings expand our knowledge of the clinical spectra of diseases caused by expansions of the same repeat motif, and further highlight how directly searching for expanded repeats can help identify mutations underlying diseases. © 2019, The Author(s), under exclusive licence to Springer Nature America, Inc
Synthesis, cytotoxicity and antineoplastic activities of novel acridine-based platinum(II) organometallic complexes
No full textTwo new platinum(II) complexes incorporating acridine ligands with aniline moieties were successfully synthesised and characterised. The acridine-based ligands were synthesised by means of Ullmann's condensation. The reaction of cis-[PtCl2(DMSO)2] with the aforementioned ligand in a specified mol ratio gives 9-phenylaminoacridine cis-dichloro(dimethylsulfoxide)-platinum(II), 2a, and bis-[N-(3,5-dimethoxyphenyl) acridin-9-amine)]chloro platinum(II), 2b. Apparently, both complexes were slightly planar and in discrete asymmetrical units. Cytotoxicity and antineoplastic activity evaluations were conducted using WRL-68, MCF-7, HT-29, and HL60 cell lines. The novel complexes exhibited potent activity towards the cell lines. Concurrently, the MTT cytotoxicity assay revealed that all complexes significantly inhibited the proliferation of MCF-7 and HL60 cells. © 2019 Elsevier B.V
In vivo dosimetry using MOSkin detector during Cobalt-60 high-dose-rate (HDR) brachytherapy of skin cancer
No full textThe MOSkin, a metal–oxide semiconductor field-effect transistor based detector, is suitable for evaluating skin dose due to its water equivalent depth (WED) of 0.07 mm. This study evaluates doses received by target area and unavoidable normal skin during a the case of skin brachytherapy. The MOSkin was evaluated for its feasibility as detector of choice for in vivo dosimetry during skin brachytherapy. A high-dose rate Cobalt-60 brachytherapy source was administered to the tumour located at the medial aspect of the right arm, complicated with huge lymphedema thus limiting the arm motion. The source was positioned in the middle of patients’ right arm with supine, hands down position. A 5 mm lead and 5 mm bolus were sandwiched between the medial aspect of the arm and lateral chest to reduce skin dose to the chest. Two calibrated MOSkin detectors were placed on the target and normal skin area for five treatment sessions for in vivo dose monitoring. The mean dose to the target area ranged between 19.9 and 21.1 Gy and was higher in comparison with the calculated dose due to contribution of backscattered dose from lead. The mean measured dose at normal skin chest area was 1.6 Gy (1.3–1.9 Gy), less than 2 Gy per fraction. Total dose in EQD2 received by chest skin was much lower than the recommended skin tolerance. The MOSkin detector presents a reliable real-time dose measurement. This study has confirmed the applicability of the MOSkin detector in monitoring skin dose during brachytherapy treatment due to its small sensitive volume and WED 0.07 mm. © 2019, Australasian College of Physical Scientists and Engineers in Medicine
Relationship between team culture and team performance through lens of knowledge sharing and team emotional intelligence
No full textPurpose: The purpose of this study is to investigate the relationship between team culture and team performance through the mediating role of knowledge sharing and team emotional intelligence. Design/methodology/approach: The study advocated that team culture influences the knowledge sharing behavior of team members and the development of emotional intelligence skill at the team level. Further, it is hypothesized that knowledge sharing and team emotional intelligence positively influence team performance. By adopting a quantitative research design, data were gathered by using a survey questionnaire from 535 respondents representing 95 teams working in private health-care institutions. Findings: The findings significantly indicated that knowledge sharing and team emotional intelligence influence team working. Furthermore, this study confirms the strong association between team culture and team performance through the lens of knowledge sharing and team emotional intelligence. Practical implications: This investigation offers observational proof to health-care services to familiarize workers with the ability of emotional intelligence and urge them to share knowledge for enhanced team performance. The study provides in-depth understanding to managers and leaders in health-care institutions to decentralize culture at the team level for endorsement of knowledge sharing behavior. Originality/value: This is amongst one of the initial studies investigating team members making a pool of knowledge to realize potential gains enormously and influenced by the emotional intelligence. Team culture set a platform to share knowledge which is considered one of the principal execution conduct essential for accomplishing and managing team adequacy in a sensitive health-care environment. © 2018, Emerald Publishing Limited
Feasibility of a Gait Phase Identification Tool for Transfemoral Amputees Using Piezoelectric- Based In-Socket Sensory System
No full textGait detection is crucial especially in active prosthetic leg control mechanism. Vision system, floor sensors, and wearable sensors are the popular methods proposed to collect data for gait detection. However, in active prosthetic leg control, a tool that is practical in its implementation and is able to provide rich gait information is important for effective manipulation of the prosthetic leg. This paper aims to ascertain the feasibility of the piezoelectric-based in-socket sensory system that is hypothesized to be practical in implementation and provide sufficient information as a wearable gait detection tool for transfemoral prosthetic users. Fifteen sensors were instrumented to the anterior and posterior internal wall of a quadrilateral socket. One transfemoral amputee subject donned the instrumented socket and performed two walking routines; single stride and continuous walking. The sensors' responses from both routines were analyzed with respect to the gait phases. The results suggested that the sensors output signal corresponds to the force components behavior of the stump while performing gait. All sensors were seen active during the first double support period (DS1). The anterior sensors were prominent during the initial swing (Sw), while posterior sensors were active during terminal Sw. These findings correspond with the muscle activity during the respective phases. Besides, the sensors also show significant pattern during single support and the second double support (DS2) phase. Thus, it can be deduced that the proposed sensory system is feasible to be used as a gait phase identification tool. © 2019 IEEE
Intraosseous lesion of phalanx: Two similar cases but not the same
No full textIntraosseous lesions at phalanges are rare. They frequently present with pain and swelling. Fortunately, the majority of the lesions are benign. However, some lesions are destructive and early interventions are required. We report two cases of similar presentations of swelling and discomfort at the little finger for six months. The lytic lesions involved the whole middle phalanx with cortical breach sparing the joints. A provisional diagnosis of osteomyelitis was made, although unlikely. Bone biopsy was performed early to plan for definitive treatment and surgery. Patient 1 was diagnosed for intraosseous gout whereas Patient 2 for epithelioid hemangioma. Both were benign destructive bone lesions. Thus, we counselled the patients for curettage of lesion, bone grafting and spanning external fixation in view of extensive lesion. Patient 1 defaulted treatment. Patient 2 had an uneventful surgery. She regained her grip strength. In two years follow up, there was no evidence of infection, recurrence or malignant transformation. © 2019, Faculty of Medicine, University of Malaya. All rights reserved
Trends in mortality among ART-treated HIV-infected adults in the Asia-Pacific region between 1999 and 2017: results from the TREAT Asia HIV Observational Database (TAHOD) and Australian HIV Observational Database (AHOD) of IeDEA Asia-Pacific
No full textIntroduction: AIDS-related deaths in people living with HIV/AIDS have been decreasing in number since the introduction of combination antiretroviral treatment (cART). However, data on recent causes of death in the Asia-Pacific region are limited. Hence, we analysed and compared AIDS-related and non-AIDS–related mortality in high- and low-income settings in the region. Methods: Patients from the TREAT Asia HIV Observational Database (TAHOD) and Australian HIV Observational Database (AHOD) receiving cART between 1999 and 2017 were included. Causes of death verification were based on review of the standardized Cause of Death (CoDe) form designed by the D:A:D group. Cohorts were grouped as AHOD (all high-income sites), TAHOD-high (high/upper-middle income countries) and TAHOD-low (lower-middle income countries). TAHOD sites were split into high/upper-middle income and lower-middle income country settings based on World Bank classifications. Competing risk regression was used to analyse factors associated with AIDS and non-AIDS–related mortality. Results: Of 10,386 patients, 522 died; 187 from AIDS-related and 335 from non-AIDS–related causes. The overall incidence rate of deaths during follow-up was 0.28 per 100 person-years (/100 PYS) for AIDS and 0.51/100 PYS for non-AIDS. Analysis indicated that the incidence rate of non-AIDS mortality decreased from 0.78/100 PYS to 0.37/100 PYS from year groups 2003 to 2007 to 2013 to 2017 (p < 0.001). Similarly, incidence rates of AIDS-related deaths decreased from 0.51/100 PYS to 0.09/100 PYS from year groups 2003 to 2007 to 2013 to 2017 (p < 0.001). More recent years of follow-up were associated with reduced hazard for non-AIDS mortality (2008 to 2012: aSHR (adjusted sub-hazard ratio) 0.72, 95% confidence interval (CI) 0.54 to 0.96, p = 0.027; 2013 to 2017: aSHR 0.64, 95% CI 0.47 to 0.87, p = 0.004) compared to years 2003 to 2007. The AHOD cohort had almost twice the hazard of non-AIDS mortality compared to TAHOD-low (lower-middle income sites) (aSHR 1.72, 95% CI, 1.20 to 2.46, p = 0.003); there were no differences between cohorts for AIDS-related mortality (p = 0.834). Conclusion: AIDS and non-AIDS–related mortality rates have decreased over the past years in the Asia-Pacific region. There is a greater risk for non-AIDS–associated deaths in the AHOD cohort compared to lower-middle income settings in TAHOD. © 2019 The Authors. Journal of the International AIDS Society published by John Wiley & Sons Ltd on behalf of the International AIDS Society