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Fulltext Subcutaneous metastasis of olfactory neuroblastoma - an uncommon presentation

Chew YK, Cheong JP, Brito-Mutunayagam S, Khir A, Prepageran N, Mun KS

Med J Malaysia, 2011 Mar;66(1):62-3.
PMID: 23765147

Olfactory neuroblastoma is a rare, slow growing, malignant tumour of neuroectodermal origin that begins in neuroepithelial cells of the olfactory membrane. A metastatic rate of 20% to 60% is reported with the most common site being the cervical lymph node. Other sites include the parotid glands, skin, lungs, bone, liver, orbit, spinal cord and spinal canal. We describe a case of olfactory neuroblastoma presented to us with scalp metastasis.
Fulltext Pulmonary modulation of benzo[a]pyrene-induced hemato- and hepatotoxicity in broilers

Latif IK, Karim AJ, Zuki AB, Zamri-Saad M, Niu JP, Noordin MM

Poult Sci, 2010 Jul;89(7):1379-88.
PMID: 20548065 DOI: 10.3382/ps.2009-00622

Aftermath in several air pollution episodes with high concentrations of polycyclic aromatic hydrocarbons did not significantly affect health and performance of broilers despite its renowned sensitivity to polycyclic aromatic hydrocarbons. The aim of the study was to elucidate the previous lack of response in birds exposed to such severe episodes of air pollution. Benzo[a]pyrene (BaP) was used to simulate the influence of air pollution on hematology, selected organ function, and oxidative stress in broilers. One-day-old chicks were assigned to 5 equal groups composed of a control group, tricaprylin group, and 3 groups treated with BaP (at 1.5 microg, 150 microg, or 15 mg/kg of BW). The BaP was intratracheally administered to 1-d-old chicks for 5 consecutive days. The hematology, liver and kidney function, P450 activity, and malondialdehyde level especially in the group receiving 15 mg of BaP/kg of BW demonstrated evidence of hemato- and hepatoxicity via BaP-induced oxidative stress. The deleterious effect of exposure to high concentration of BaP in broiler chickens was probably due to the anatomy of this species and the half-life of BaP. Although the effect of BaP may be transient or irreversible, pathogen challenges faced during the period of suppression may prove fatal.
Islet autoimmunity status in Asians with young-onset diabetes (12-40 years): association with clinical characteristics, beta cell function and cardio-metabolic risk factors

Thai AC, Mohan V, Khalid BA, Cockram CS, Pan CY, Zimmet P, et al.

Diabetes Res Clin Pract, 2008 May;80(2):224-30.
PMID: 18207602 DOI: 10.1016/j.diabres.2007.12.003

In this paper, the islet autoimmunity status and relation to clinical characteristics, beta cell function and cardio-metabolic risk factors in young-onset Asian diabetic patients are evaluated at baseline. The study population consisted of 912 patients (from China, India, Malaysia and Singapore) with age 12-40 years and diabetes duration <12 months. Autoantibodies to glutamic acid decarboxylase (GADA) and tyrosine phosphatase (IA-2A), beta cell function and cardio-metabolic risk parameters were assessed. Among our young patient cohort, 105 (11.5%) patients were GADA and/or IA-2A positives (Ab +ve). Ab +ve patients were younger, leaner, had more severe hyperglycaemia and lower beta cell function. The frequency of metabolic syndrome was significantly lower in Ab +ve patients (27%) compared to Ab -ve patients (54%). However, a substantial proportion of patients in both groups of patients had atherogenic dyslipidaemia, hypertension and albuminuria (micro or macro). In our study cohort, only one in 10 Asian youth with new-onset diabetes had evidence of islet autoimmunity. At least 60% of Ab +ve and 50% of Ab -ve patients demonstrated classical features of type 1 and type 2 diabetes respectively. Regardless of autoimmunity status, the cardio-metabolic risk factors, in particular atherogenic dyslipidaemia, hypertension and albuminuria were common in our patients with young-onset diabetes.
Fulltext Third ventricular cavernous angioma

Zakaria MA, Abdullah JM, George JP, Mutum SS, Lee NN

Med J Malaysia, 2006 Jun;61(2):229-32.
PMID: 16898318 MyJurnal

Third ventricular cavernous angiomas are rare vascular malformations of the brain. We report an eight-year old boy with a rare third ventricular cavernous angioma that hemorrhaged presenting with symptoms of acute hydrocephalus. Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) showed a heterogenous ill-defined, solid and cystic intraventricular mass in the third ventricle which was mildly enhanced with contrast and there was associated hydrocephalus. The mass was removed with success and follow up after two years revealed no neurological abnormalities.
Fulltext Does clinical exposure to patients in medical school affect trainee doctors' attitudes towards mental disorders and patients?--A pilot study

Tan SMK, Azmi MT, Reddy JP, Shaharom MH, Rosdinom R, Maniam T, et al.

Med J Malaysia, 2005 Aug;60(3):328-37.
PMID: 16379188

Stigmatising attitudes towards mental illness may improve with clinical exposure during medical school training. Attitudes of 48 fourth year medical students in Universiti Kebangsaan Malaysia were assessed before and after their compulsory attachment in Psychiatry, using the Attitude Towards Psychiatry-30 (ATP) and the Attitude towards Mental Illness (AMI) questionnaires. ATP scores improved significantly with training (104.8 and 114.4, pre- and post-attachment respectively) as did AMI scores (63.4 and 68.1 respectively). Both improvements were statistically significant. (ATP: z = 4.55, p < 0.0005) (AMI: z = 3.75, p < 0.0005). Attitudes towards mental illness appeared to have become more favourable with clinical training in psychiatry.
Molecular epidemiology and evolution of enterovirus 71 strains isolated from 1970 to 1998

Brown BA, Oberste MS, Alexander JP, Kennett ML, Pallansch MA

J Virol, 1999 Dec;73(12):9969-75.
PMID: 10559310

Enterovirus 71 (EV71) (genus Enterovirus, family Picornaviridae), a common cause of hand, foot, and mouth disease (HFMD), may also cause severe neurological diseases, such as encephalitis and poliomyelitis-like paralysis. To examine the genetic diversity and rate of evolution of EV71, we have determined and analyzed complete VP1 sequences (891 nucleotides) for 113 EV71 strains isolated in the United States and five other countries from 1970 to 1998. Nucleotide sequence comparisons demonstrated three distinct EV71 genotypes, designated A, B, and C. The genetic variation within genotypes (12% or fewer nucleotide differences) was less than the variation between genotypes (16.5 to 19.7%). Strains of all three genotypes were at least 94% identical to one another in deduced amino acid sequence. The EV71 prototype strain, BrCr-CA-70, isolated in California in 1970, is the sole member of genotype A. Strains isolated in the United States and Australia during the period from 1972 to 1988, a 1994 Colombian isolate, and isolates from a large HFMD outbreak in Malaysia in 1997 are all members of genotype B. Although strains of genotype B continue to circulate in other parts of the world, none have been isolated in the United States since 1988. Genotype C contains strains isolated in 1985 or later in the United States, Canada, Australia, and the Republic of China. The annual rate of evolution within both the B and C genotypes was estimated to be approximately 1.35 x 10(-2) substitutions per nucleotide and is similar to the rate observed for poliovirus. The results indicate that EV71 is a genetically diverse, rapidly evolving virus. Its worldwide circulation and potential to cause severe disease underscore the need for additional surveillance and improved methods to identify EV71 in human disease.
Antimitotic and cytotoxic flavonols from Zieridium pseudobtusifolium and Acronychia porteri

Lichius JJ, Thoison O, Montagnac A, Païs M, Guéritte-Voegelein F, Sévenet T, et al.

J Nat Prod, 1994 Jul;57(7):1012-6.
PMID: 7964782

Bioassay-guided fractionation of the extracts of Zieridium pseudobtusifolium and Acronychia porteri led to the isolation of 5,3'-dihydroxy-3,6,7,8,4'-pentamethoxyflavone [1], which showed activity against (KB) human nasopharyngeal carcinoma cells (IC50 0.04 micrograms/ml) and inhibited tubulin assembly into microtubules (IC50 12 microM). Two other known flavonols, digicitrin [2] and 5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone [5], were also isolated together with three new ones, 3-O-demethyldigicitrin [3], 3,5,3'-trihydroxy-6,7,8,4'-tetramethoxyflavone [4], and 3,5-dihydroxy-6,7,8,3',4'-pentamethoxyflavone [6]. All of these flavonols showed cytotoxic activity against KB cells.
Nutrition in adverse environments, 3. The metabolic effects of a restricted food intake on men working in a tropical environment

Crowdy JP, Consolazio CF, Forbes AL, Haisman MF, Worsley DE

Hum Nutr Appl Nutr, 1982 Oct;36(5):325-44.
PMID: 7141879

As part of a research programme concerned with the need to lighten the load carried by soldiers engaged in long foot patrols, a field experiment was undertaken in West Malaysia. For 12 d a group of 15 men consumed 7.4 MJ/d (1770 kcal/d) whilst a control group of 14 men ate 12.9 MJ/d (3080 kcal/d); both groups expended on average about 15.8 MJ/d (3770 kcal/d). The low-energy group incurred an energy deficit of 98 MJ (23 410 kcal) with a weight loss of 3.9 kg, whereas corresponding figures for the control group were 37 MJ (8840 kcal) and 2.4 kg. Before, during and after the energy deprivation phase, assessment was made of work capacity (estimated VO2 max), vigilance and military skills but no difference was found between the groups.
Fulltext Group B adenovirus enadenotucirev infects polarised colorectal cancer cells efficiently from the basolateral surface expected to be encountered during intravenous delivery to treat disseminated cancer

Chia SL, Lei J, Ferguson DJP, Dyer A, Fisher KD, Seymour LW

Virology, 2017 05;505:162-171.
PMID: 28260622 DOI: 10.1016/j.virol.2017.02.011

Enadenotucirev (EnAd) is a group B oncolytic adenovirus developed for systemic delivery and currently undergoing clinical evaluation for advanced cancer therapy. For differentiated carcinomas, systemic delivery would likely expose virus particles to the basolateral surface of cancer cells rather than the apical surface encountered during natural infection. Here, we compare the ability of EnAd and adenovirus type-5 (Ad5) to infect polarised colorectal carcinoma cells from the apical or basolateral surfaces. Whereas Ad5 infection was more efficient via the apical than basolateral surface, EnAd readily infected cells from either surface. Progeny particles from EnAd were released preferentially via the apical surface for all cell lines and routes of infection. These data further support the utility of group B adenoviruses for systemic delivery and suggest that progeny virus are more likely to be released into the tumour rather than back through the basolateral surface into the blood stream.
Fulltext Physiologically Relevant Alternative Carbon Sources Modulate Biofilm Formation, Cell Wall Architecture, and the Stress and Antifungal Resistance of Candida glabrata

Chew SY, Ho KL, Cheah YK, Sandai D, Brown AJP, Than LTL

Int J Mol Sci, 2019 Jun 28;20(13).
PMID: 31261727 DOI: 10.3390/ijms20133172

Flexibility in carbon metabolism is pivotal for the survival and propagation of many human fungal pathogens within host niches. Indeed, flexible carbon assimilation enhances pathogenicity and affects the immunogenicity of Candida albicans. Over the last decade, Candida glabrata has emerged as one of the most common and problematic causes of invasive candidiasis. Despite this, the links between carbon metabolism, fitness, and pathogenicity in C. glabrata are largely unexplored. Therefore, this study has investigated the impact of alternative carbon metabolism on the fitness and pathogenic attributes of C. glabrata. We confirm our previous observation that growth on carbon sources other than glucose, namely acetate, lactate, ethanol, or oleate, attenuates both the planktonic and biofilm growth of C. glabrata, but that biofilms are not significantly affected by growth on glycerol. We extend this by showing that C. glabrata cells grown on these alternative carbon sources undergo cell wall remodeling, which reduces the thickness of their β-glucan and chitin inner layer while increasing their outer mannan layer. Furthermore, alternative carbon sources modulated the oxidative stress resistance of C. glabrata as well as the resistance of C. glabrata to an antifungal drug. In short, key fitness and pathogenic attributes of C. glabrata are shown to be dependent on carbon source. This reaffirms the perspective that the nature of the carbon sources available within specific host niches is crucial for C. glabrata pathogenicity during infection.
Khat (Catha edulis) upregulates lipolytic genes in white adipose tissue of male obese mice (C57BL/6J)

Alshagga MA, Mohamed Z, Seyedan A, Ebling FJP, Alshawsh MA

J Ethnopharmacol, 2020 Nov 15;262:113187.
PMID: 32730892 DOI: 10.1016/j.jep.2020.113187

ETHNOPHARMACOLOGICAL RELEVANCE: Khat (Catha edulis (Vahl) Forssk.) is a herb from the Celastraceae family (also known as qat, gaad, or mirra) that is widely-consumed in East Africa and in the Arabian peninsula. The green leaves and small stems are consumed primarily at recreational and social gatherings, and medicinally for their antidiabetic and appetite-suppression effects.
AIMS: The objectives of this study were to determine the effects of khat and its active alkaloid, cathinone, on food intake and body weight in mice maintained on a high-fat diet, and to investigate its mechanism of action in white adipose tissue and in the hypothalamus.
MATERIALS & METHOD: Adult male mice (C57BL/6J) were fed a high fat diet (HFD) for 8 weeks (n = 30), then divided into 5 groups and treated daily for a further 8 weeks with HFD + vehicle [control (HFD)], HFD + 15 mg/kg orlistat (HFDO), HFD + 200 mg/kg khat extract (HFDK200), HFD + 400 mg/kg khat extract (HFDK400) and HFD + 3.2 mg/kg cathinone (HFDCAT). Treatments were carried out once daily by gastric gavage. Blood and tissue samples were collected for biochemical, hormonal and gene expression analyses.
RESULTS: Khat extracts and orlistat treatment significantly reduced weight gain as compared to control mice on HFD, and cathinone administration completely prevented weight gain in mice fed on HFD. Khat treatment caused a marked reduction in body fat and in serum triglycerides. A dose-dependent effect of khat was observed in reducing serum leptin concentrations. Analysis of gene expression in adipose tissue revealed a significant upregulation of two lipolysis pathway genes:(adipose triglyceride lipase (PNPLA-2) and hormone-sensitive lipase (LIPE). In the hypothalamic there was a significant (P
Classification of diabetes in young Asians based on islet autoimmunity and beta-cell function. [Abstract]

Thai AC, Mohan V, Khalid BAK, Cockram C, Pan CY, Zimmet P, et al.

Diabetologia, 2004 Aug;47(Suppl 1):A294.
PMID: 27770180

Backgrounds and aims: The Asian Young Diabetes (ASDIAB) project is a five-year prospective study on the clinical and immunological characterisation of diabetes in newly diagnosed young Asians. This paper aims at evaluating the aetiological classification of diabetes in these patients based on presence/absence of islet autoantibodies and beta cell function at disease presentation and one year.
Materials and methods: A total of 919 patients (from Beijing, Shanghai, Hong Kong, India, Malaysia and Singapore) with age at diagnosis 12-40 years and diabetes duration <12 months were recruited between 1997 and 1999. Complete information on autoantibodies to glutamic acid decarboxylase (GAD) and IA-2 and fasting C-peptide at baseline and 1 year were available in 633 patients. Antibody positivity (Ab+) was defined by presence of GADab and/or IA-2 abo Poor beta-cell function was defined with fasting C-peptide <0.3nM at one year. TlDM was identified in patients Ab+ at diagnosis (irregardless of p cell function status) and in those Ab- at diagnosis and I-year, but demonstrated poor beta-cell function at I-year. Patients who were Ab- at diagnosis and I-year but had good beta cell function (fasting C-peptide >=0.3nM) at I-year were classified as having type 2 diabetes (T2DM).
Results: 139 patients (22%) were classified as having T1DM. Of these, 90 were Ab+ and 49 were Ab- and had poor beta cell function. The remainder 494 patients (78%) were classified as having T2DM. The ethnic distribution of T1DM patients (73% Chinese, 16% Indians and 11 % Malays) was similar to the T2DM. Compared to T2DM, T1DM patients were significantly younger at diagnosis (mean age 28.0 vs 32.9 yrs), leaner (mean BMI 21.5 kg/m' vs 25.9 kg/m' at diagnosis, 22.0 kg/m2 vs 26.1 kg/m2 at 1 year), and had significantly higher HbA1 , (11.8% vs 9.7% at diagnosis; 8.9% vs 8.0% at 1 year) . Median fasting C-peptides were significantly lower in T1DM than T2DM patients (0.2 vs 0.7 nM at diagnosis; 0.2 vs 0.8 nM at 1 year). T2DM were more insulin resistant than T1DM patients as assessed by HOMA index (median 5.8 vs 4.4 at diagnosis, 4.9 vs 3.4 at 1 year).
Conclusions: In Asians with young onset diabetes, assessment at diagnosis and one year for islet autoantibodies (GADab and lor IA-2Aab), together with estimation of p-cell function with fasting serum C-peptide levels, were useful for classifying patients as having T1DM and T2DM .
Grant from Novo Nordisk Asia Pacific, Singapore
40th EASD Annual Meeting of the European Association for the Study of Diabetes : Munich, Germany, 5-9 September 2004
Fulltext Lightweight and Efficient Dynamic Cluster Head Election Routing Protocol for Wireless Sensor Networks

Yagoub MFS, Khalifa OO, Abdelmaboud A, Korotaev V, Kozlov SA, Rodrigues JJPC

Sensors (Basel), 2021 Jul 31;21(15).
PMID: 34372449 DOI: 10.3390/s21155206

Wireless Sensor Networks (WSNs) have gained great significance from researchers and industry due to their wide applications. Energy and resource conservation challenges are facing the WSNs. Nevertheless, clustering techniques offer many solutions to address the WSN issues, such as energy efficiency, service redundancy, routing delay, scalability, and making WSNs more efficient. Unfortunately, the WSNs are still immature, and suffering in several aspects. This paper aims to solve some of the downsides in existing routing protocols for WSNs; a Lightweight and Efficient Dynamic Cluster Head Election routing protocol (LEDCHE-WSN) is proposed. The proposed routing algorithm comprises two integrated methods, electing the optimum cluster head, and organizing the re-clustering process dynamically. Furthermore, the proposed protocol improves on others present in the literature by combining the random and periodic electing method in the same round, and the random method starts first at the beginning of each round/cycle. Moreover, both random and periodic electing methods are preceded by checking the remaining power to skip the dead nodes and continue in the same way periodically with the rest of the nodes in the round. Additionally, the proposed protocol is distinguished by deleting dead nodes from the network topology list during the re-clustering process to address the black holes and routing delay problems. Finally, the proposed algorithm's mathematical modeling and analysis are introduced. The experimental results reveal the proposed protocol outperforms the LEACH protocol by approximately 32% and the FBCFP protocol by 8%, in terms of power consumption and network lifetime. In terms of Mean Package Delay, LEDCHE-WSN improves the LEACH protocol by 42% and the FBCFP protocol by 15%, and regarding Loss Ratio, it improves the LEACH protocol by approximately 46% and FBCFP protocol by 25%.
Eating patterns and prevalence of obesity. Lessons learned from the Malaysian Food Barometer

Fournier T, Tibère L, Laporte C, Mognard E, Ismail MN, Sharif SP, et al.

Appetite, 2016 12 01;107:362-371.
PMID: 27521166 DOI: 10.1016/j.appet.2016.08.009

The Malaysian society is experiencing and coping with a fast modernization process, which is characterized by a rapid urbanization and rural exodus, an important reduction of the size of households, and the emergence of a new middle class. The Malaysian Food Barometer launched in 2013 has provided better understanding how these macro issues have affected the lifestyles and especially the food habits of the Malaysians. The country has indeed undergone a transition period from under-nutrition to over-nutrition in a few decades, with the prevalence of overweight and obesity having markedly and rapidly increased. A quantitative survey (n = 2000), elaborated from a qualitative preliminary phase, was carried out with the aim of analyzing the transformation of food habits at the national level. The present article focuses on the BMI issue in Malaysia, and investigates its relationships with the socio-demographic variables of the population, as well as their eating patterns. The mean BMI is 23.64 kg/m2, with 9.5% of the sample being obese, and 22% overweight. Strong statistical associations have been identified between BMI and independent variables such as size of the living area, ethnicity, level of education, gender, and age. Contrary to general believe, overweight and obesity were neither associated with the number of food intakes taken per day (including snacks) nor with the frequency of eating out. Nonetheless, obesity is over-represented in people who have dissonant eating behaviors, i.e. who declare having fewer food intakes a day (food norms) than they do actually (food practices). This process testifies that the Malaysians are experiencing a "food transition", which is linked with socio-economic development.
Surface-state dependent optical properties of OH-, F-, and H-terminated 4H-SiC quantum dots

Rashid M, Tiwari AK, Goss JP, Rayson MJ, Briddon PR, Horsfall AB

Phys Chem Chem Phys, 2016 Aug 03;18(31):21676-85.
PMID: 27430278 DOI: 10.1039/c6cp03775e

Density functional calculations are performed for OH-, F- and H-terminated 4H-SiC 10-20 Å diameter clusters to investigate the effect of surface species upon the optical absorption properties. H-termination results in a pronounced size-dependent quantum-confinement in the absorption, whereas F- and OH-terminations exhibit much reduced size dependent absorption due to surface states. Our findings are in good agreement with recent experimental studies, and are able to explain the little explored dual-feature photoluminescence spectra of SiC quantum dots. We propose that along with controlling the size, suitable surface termination is the key for optimizing optical properties of 4H-SiC quantum structures, such as might be exploited in optoelectronics, photovoltaics and biological applications.
In vitro assessment of ribose modified two-step etch-and-rinse dentine adhesive

Daood U, Tsoi JKH, Neelakantan P, Matinlinna JP, Omar HAK, Al-Nabulsi M, et al.

Dent Mater, 2018 08;34(8):1175-1187.
PMID: 29779627 DOI: 10.1016/j.dental.2018.05.005

OBJECTIVE: Collagen fibrils aid in anchoring resin composite restorations to the dentine substrate. The aim of the study was to investigate effect of non-enzymatic glycation on bond strength and durability of demineralized dentine specimens in a modified two-step etch-and-rinse dentine adhesive.
METHODS: Dentine surfaces were etched with 37% phosphoric acid, bonded with respective in vitro ethanol and acetone adhesives modified with (m/m, 0, 1%, 2% and 3% ribose), restored with restorative composite-resin, and sectioned into resin-dentine slabs and beams to be stored for 24h or 12 months in artificial saliva. Bond-strength testing was performed with bond failure analysis. Pentosidine assay was performed on demineralized ribose modified dentine specimens with HPLC sensitive fluorescent detection. The structural variations of ribose-modified dentine were analysed using TEM and human dental pulpal cells were used for cell viability. Three-point bending test of ribose-modified dentine beams were performed and depth of penetration of adhesives evaluated with micro-Raman spectroscopy. The MMP-2 and cathepsin K activities in ribose-treated dentine powder were also quantified using ELISA. Bond strength data was expressed using two-way ANOVA followed by Tukey's test. Paired T tests were used to analyse the specimens for pentosidine crosslinks. The modulus of elasticity and dentinal MMP-2 and cathepsin K concentrations was separately analyzed using one-way ANOVA.
RESULTS: The incorporation of RB in the experimental two-step etch-and-rinse adhesive at 1% improved the adhesive bond strength without adversely affecting the degree of polymerisation. The newly developed adhesive increases the resistance of dentine collagen to degradation by inhibiting endogenous matrix metalloproteinases and cysteine cathepsins. The application of RB to acid-etched dentine helps maintain the mechanical properties.
SIGNIFICANCE: The incorporation of 1%RB can be considered as a potential candidate stabilizing resin dentine bond.
Information-Centric Network-Based Vehicular Communications: Overview and Research Opportunities

Din IU, Kim BS, Hassan S, Guizani M, Atiquzzaman M, Rodrigues JJPC

Sensors (Basel), 2018 Nov 15;18(11).
PMID: 30445723 DOI: 10.3390/s18113957

Information Centric Network (ICN) is expected to be the favorable deployable future Internet paradigm. ICN intends to replace the current IP-based model with the name-based content-centric model, as it aims at providing better security, scalability, and content distribution. However, it is a challenging task to conceive how ICN can be linked with the other most emerging paradigm, i.e., Vehicular Ad hoc Network (VANET). In this article, we present an overview of the ICN-based VANET approach in line with its contributions and research challenges.In addition, the connectivity issues of vehicular ICN model is presented with some other emerging paradigms, such as Software Defined Network (SDN), Cloud, and Edge computing. Moreover, some ICN-based VANET research opportunities, in terms of security, mobility, routing, naming, caching, and fifth generation (5G) communications, are also covered at the end of the paper.
An in vitro study of a novel quaternary ammonium silane endodontic irrigant

Daood U, Parolia A, Elkezza A, Yiu CK, Abbott P, Matinlinna JP, et al.

Dent Mater, 2019 09;35(9):1264-1278.
PMID: 31201019 DOI: 10.1016/j.dental.2019.05.020

OBJECTIVE: To analyze effect of NaOCl+2% quaternary ammonium silane (QAS)-containing novel irrigant against bacteria impregnated inside the root canal system, and to evaluate its antimicrobial and mechanical potential of dentine substrate.
METHODS: Root canal was prepared using stainless steel K-files™ and ProTaper™ and subjected to manual and ultrasonic irrigation using 6% NaOCl+2% CHX, 6% NaOCl+2% QAS and saline as control. For confocal-microscopy, Raman spectroscopy and SEM analysis before and after treatment, Enterococcus faecalis cultured for 7 days. Raman spectroscopy analysis was done across cut section of gutta percha/sealer-dentine to detect resin infiltration. Indentation of mechanical properties was evaluated using a Berkovich indenter. The contact angle of irrigants and surface free energy were evaluated. Mineralization nodules were detected through Alazarin red after 14 days.
RESULTS: Control biofilms showed dense green colonies. Majority of E. faecalis bacteria were present in biofilm fluoresced red in NaOCl+2% QAS group. There was reduction of 484cm-1 Raman band and its intensity reached lowest with NaOCl+2% QAS. There was an increase in 1350-1420cm-1 intensity in the NaOCl+2% CHX groups. Gradual decrease in 1639cm-1 and 1609cm-1 Raman signal ratios were seen in the resin-depth region of 17μm>, 14.1μm> and 13.2μm for NaOCl+2% QAS, NaOCl+2% CHX and control groups respectively. All obturated groups showed an intact sealer/dentine interface with a few notable differences. 0.771 and 83.5% creep indentation distance for NaOCl+2% QAS ultrasonic groups were observed. Highest proportion of polar component was significantly found in the NaOCl+2% QAS groups which was significantly higher as compared to other groups. Mineralized nodules were increased in NaOCl+2% QAS.
SIGNIFICANCE: Favorable antimicrobial and endodontic profile of the NaOCl+2% QAS solution might suggest clinical use for it for more predictable reduction of intracanal bacteria.
Fulltext TARS: A Novel Mechanism for Truly Autonomous Resource Selection in LTE-V2V Mode 4

Khan IA, Shah SAA, Akhunzada A, Gani A, Rodrigues JJPC

Sensors (Basel), 2021 Nov 09;21(22).
PMID: 34833507 DOI: 10.3390/s21227431

Effective communication in vehicular networks depends on the scheduling of wireless channel resources. There are two types of channel resource scheduling in Release 14 of the 3GPP, i.e., (1) controlled by eNodeB and (2) a distributed scheduling carried out by every vehicle, known as Autonomous Resource Selection (ARS). The most suitable resource scheduling for vehicle safety applications is the ARS mechanism. ARS includes (a) counter selection (i.e., specifying the number of subsequent transmissions) and (b) resource reselection (specifying the reuse of the same resource after counter expiry). ARS is a decentralized approach for resource selection. Therefore, resource collisions can occur during the initial selection, where multiple vehicles might select the same resource, hence resulting in packet loss. ARS is not adaptive towards vehicle density and employs a uniform random selection probability approach for counter selection and reselection. As a result, it can prevent some vehicles from transmitting in a congested vehicular network. To this end, the paper presents Truly Autonomous Resource Selection (TARS) for vehicular networks. TARS considers resource allocation as a problem of locally detecting the selected resources at neighbor vehicles to avoid resource collisions. The paper also models the behavior of counter selection and resource block reselection on resource collisions using the Discrete Time Markov Chain (DTMC). Observation of the model is used to propose a fair policy of counter selection and resource reselection in ARS. The simulation of the proposed TARS mechanism showed better performance in terms of resource collision probability and the packet delivery ratio when compared with the LTE Mode 4 standard and with a competing approach proposed by Jianhua He et al.
Fulltext DC-GAN-based synthetic X-ray images augmentation for increasing the performance of EfficientNet for COVID-19 detection

Shah PM, Ullah H, Ullah R, Shah D, Wang Y, Islam SU, et al.

Expert Syst, 2021 Oct 19.
PMID: 34898799 DOI: 10.1111/exsy.12823

Currently, many deep learning models are being used to classify COVID-19 and normal cases from chest X-rays. However, the available data (X-rays) for COVID-19 is limited to train a robust deep-learning model. Researchers have used data augmentation techniques to tackle this issue by increasing the numbers of samples through flipping, translation, and rotation. However, by adopting this strategy, the model compromises for the learning of high-dimensional features for a given problem. Hence, there are high chances of overfitting. In this paper, we used deep-convolutional generative adversarial networks algorithm to address this issue, which generates synthetic images for all the classes (Normal, Pneumonia, and COVID-19). To validate whether the generated images are accurate, we used the k-mean clustering technique with three clusters (Normal, Pneumonia, and COVID-19). We only selected the X-ray images classified in the correct clusters for training. In this way, we formed a synthetic dataset with three classes. The generated dataset was then fed to The EfficientNetB4 for training. The experiments achieved promising results of 95% in terms of area under the curve (AUC). To validate that our network has learned discriminated features associated with lung in the X-rays, we used the Grad-CAM technique to visualize the underlying pattern, which leads the network to its final decision.

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