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The effect of fiber post location on fracture resistance of endodontically treated maxillary premolars
Get PDFBackground. There is no sufficient literature on the effect of post location on endodontically treated premolar teeth with 2 roots. Objectives. The aim of the study was to evaluate the effect of fiber post location on fracture resistance and failure mode of endodontically treated premolars with 2 roots. Material and methods. Fifty extracted maxillary first premolars with 2 roots were divided randomly into 5 groups. Group 1 was comprised of sound teeth, which received only metal crowns (control). Teeth from groups 2, 3, 4, and 5 were decoronated 2 mm above the cementoenamel junction (CEJ) and were endodontically treated. No post was placed in group 2 teeth. Teeth from groups 3, 4 and 5 were given a fiber post placed in the buccal canal, palatal canal, and both buccal and palatal canals, respectively. All teeth in groups 2, 3, 4, and 5 were built up with composite and full coverage metal crowns. A compressive static load was applied at an angle of 25 degrees to the crowns with a crosshead speed of 0.5 mm/min, until fracture. Results. One-way analysis of variance (ANOVA) showed significant differences among the groups (p = 0.002). A post hoc test showed significantly lower fracture resistance of group 4 compared to group 5 (p = 0.011). Furthermore, group 2 had significantly less fracture resistance compared to group 1 (p = 0.021) and group 5 (p = 0.002). According to Fisher's exact test, different post locations are non-significantly associated with fracture mode (p = 0.256). Conclusions. Fiber post location has a significant effect on fracture resistance of severely damaged, endodontically treated maxillary premolars with 2 roots. However, post placement in the palatal root is preferred, as it maintains the restorability of the tooth
A new species of black fly with a yellow thorax in the genus Prosimulium (Diptera: Simuliidae) in Japan
No full textA new species of black fly, Prosimulium kazukii, is described based on female, male and pupal specimens collected from central Honshu, Japan. It is placed in the Prosimulium magnum species-group, and is characterized in the female and male by yellow thoraces, and in the pupa by the frons and dorsal surface of the thorax without distinct tubercles. By these characters, it is distinguished from all four related species (P. apoina Ono, P. kalibaense Ono, P. sarurense Ono, and P. yezoense Shiraki) of the same species-group in Japan. The female of this new species was previously known as an aberrant form of P. yezoense
Tuberculous optochiasmatic arachnoiditis and optochiasmatic tuberculoma in Malaysia
No full textBackground & Objectives: Arachnoiditis which involves the optic chiasm and optic nervecan rarely occurs in the patients with tuberculous meningitis (TBM). The primary objective of this study was to determine the incidence, assess the clinical and neuroimaging findings, and associations, understand its pathogenesis of these patients, and determine its prognosis. Methods: The patients admitted with TBM in the neurology wards of two tertiary care hospitals from 2009 to 2017 in Kuala Lumpur, Malaysia were screened. The patients with OCA and optochiasmatic tuberculoma were included in this study. We assessed the clinical, cerebrospinal fluid (CSF), imaging findings of the study subjects and compared with other patients without OCA or optochiasmatic tuberculoma. Results: Eighty-eight patients with TBM were seen during the study period. Seven (8.0%) had OCA and one (1.1%) had optochiasmatic tuberculoma. Five out of seven (71.4%) patients with OCA were newly diagnosed cases of TBM. The other two (28.6%) had involvement while on treatment with antituberculous treatment (paradoxical manifestation). The mean age of the patients with OCA was 27.3 ± 11.7. All the OCA patients had leptomeningeal enhancement at other sites. All had hydrocephalus and cerebral infarcts on brain neuroimaging. Three (42.9%) patients had cerebral tuberculoma at sites other than suprasellar and optic chiasm areas. On univariate analysis, the presence of OCA and optochiasmatic tuberculoma was associated with raised CSF opening pressure (p=0.014), younger age (p=0.024), cerebral infarcts (p=0.018) and hydrocephalus (p= 0.046). There was no statistically significant association on logistic regression. Only one (14.3%) patient had visual impairment. Conclusion: OCA and optochiasmatic tuberculoma were seen in 9% of a cohort of Malaysian TBM patients. They were more likely to be younger, have raised CSF opening pressure, cerebral infarcts and hydrocephalus, suggesting the association with a more severe exudative disease
Evaluation of h and h-type Indices for Research Performance at Researcher's Level
No full textVarious new performance evaluation indices for impact have been proposed and studied in various contexts. This study carried out a quantitative evaluation of the case of Malaysian engineering researchers at the micro level using a scientometric approach. In order to understand the behavior of new developments, a comparative performance evaluation is carried out of h-index, a set of h-type indices along with publication and citation metrics. Findings are compared with earlier major studies. We looked for institutional h-index and researchers’ h-index scores and did not find any relationship. Exploratory Factor Analysis is employed to examine the valid categorization and to study the underlying dimensions of the studied metrics and indices. The inter-correlation among h-index, its variants, and traditional metrics is probed in detail. The h, q and g-indices along with publication and citation hold the position on ‘quantity of the productive core’, while the R index showed equal loading on both cores. For the case of Malaysian engineering researchers, two conspicuous findings are observed about the total citation and g-index. These have association with the first component named as ‘quantity of the productive core.’ Our findings strengthen the point that citation count has a strong association with the ‘quantity of the productive core’ and cannot be used as sole impact evaluation measure
Preparation of Biodiesel from Hibiscus sabdariffa Seeds Oil using Calcium Oxide Catalyst from Waste Egg Shells
Get PDFThe aim of this study is to optimize the transesterification process for conversion of Hibiscus sabdariffa seed oils (HSO) into biodiesel. Conversion of HSO into biodiesel were obtained at optimum parameters of methanol to oil ratio 6:1, temperature 67.5oC, 1% calcium oxide (CaO) catalyst derived from waste egg shells and agitation speed of 750 rpm. The yield achieved was 95.01%. The results showed that all of the fuel properties such as kinematic viscosity 4.55 mm2/s acid value 0.027 mg KOH/g, cloud point 3oC, pour point 1oC, flash point 161oC, cetane index 49 min and density 856 kg/m3 of the Hibiscus sabdariffa methyl esters (HSME), are in compliance within the range of ASTM D6751 and EN 14214 standard specifications except for oxidation stability which was at 3.48 hours. The results suggested that Hibiscus sabdariffa seed oil could be a potential feedstock for biodiesel
Complete mitochondrial genome of Bactrocera ritsemai (Insecta: Tephritidae) and phylogenetic relationship with its congeners and related tephritid taxa
No full textBactrocera ritsemai is a dacine fruit fly found in Indonesia. We report here the complete mitogenome of this fruit fly from Lombok, Indonesia determined by Illumina MiSeq sequencing and its phylogenetic relationship with its congeners and related tephritid taxa. The whole mitogenome of B. ritsemai had a total length of 15,927 bp, comprising 37 genes – 13 protein-coding genes (PCGs), 2 ribosomal ribonucleic acid (rRNA) and 22 transfer ribonucleic acid (tRNA) genes – and a control region (D-loop). Of the PCGs, 6 (atp6, cob, cox2, cox3, nad4, nad4l) had ATG start codon, 4 (nad2, nad3, nad5, nad6) had ATT, and one each had ATA (nad1), GTG (atp8) and TCG (cox1). Seven PCGs (atp6, atp8, cox2, cox3, nad2, nad4l, nad6) had TAA stop codon, 3 (cob, nad3, nad4) had TAG, and 3 had incomplete stop codon (cox1 – TA; nad1, nad5 – T). The TΨC-loop of tRNA was absent in trnF while trnS1 lacked the DHU-loop. Phylogenetic analysis based on 15 mt-genes (13 PCGs + 2 rRNA genes) indicated B. ritsemai forming a sister group with B. umbrosa and the subgenus Bactrocera was monophyletic. The genera Bactrocera and Zeugodacus were monophyletic while the subfamilies Dacinae and Tephritinae were paraphyletic. A broader taxa sampling of the Tephritidae is needed to better elucidate the phylogenetics and systematics of the tribes and subfamilies of tephritid fruit flies
Functional Role of Tyr12 in the Catalytic Activity of Novel Zeta-like Glutathione S-transferase from Acidovorax sp. KKS102
No full textGlutathione S-transferases (GSTs) are a family of enzymes that function in the detoxification of variety of electrophilic substrates. In the present work, we report a novel zeta-like GST (designated as KKSG9) from the biphenyl/polychlorobiphenyl degrading organism Acidovorax sp. KKS102. KKSG9 possessed low sequence similarity but similar biochemical properties to zeta class GSTs. Functional analysis showed that the enzyme exhibits wider substrate specificity compared to most zeta class GSTs by reacting with 1-chloro-2,4-dinitrobenzene (CDNB), p-nitrobenzyl chloride (NBC), ethacrynic acid (EA), hydrogen peroxide, and cumene hydroperoxide. The enzyme also displayed dehalogenation function against dichloroacetate, permethrin, and dieldrin. The functional role of Tyr12 was also investigated by site-directed mutagenesis. The mutant (Y12C) displayed low catalytic activity and dehalogenation function against all the substrates when compared with the wild type. Kinetic analysis using NBC and GSH as substrates showed that the mutant (Y12C) displayed a higher affinity for NBC when compared with the wild type, however, no significant change in GSH affinity was observed. These findings suggest that the presence of tyrosine residue in the motif might represent an evolutionary trend toward improving the catalytic activity of the enzyme. The enzyme as well could be useful in the bioremediation of various types of organochlorine pollutants
Sentiment Analysis of Big Data: Methods, Applications, and Open Challenges
No full textThe development of IoT technologies and the massive admiration and acceptance of social media tools and applications, new doors of opportunity have been opened for using data analytics in gaining meaningful insights from unstructured information. The application of opinion mining and sentiment analysis (OMSA) in the era of big data have been used a useful way in categorizing the opinion into different sentiment and in general evaluating the mood of the public. Moreover, different techniques of OMSA have been developed over the years in different data sets and applied to various experimental settings. In this regard, this paper presents a comprehensive systematic literature review, aims to discuss both technical aspect of OMSA (techniques and types) and non-technical aspect in the form of application areas are discussed. Furthermore, this paper also highlighted both technical aspects of OMSA in the form of challenges in the development of its technique and non-technical challenges mainly based on its application. These challenges are presented as a future direction for research
Review of Hans Volker Wolf, Looi Wai Ling, Stefanie Pillai, and Adriana Phillip (eds), The Mousedeer and the Crocodiles: A Malaysian Folktale in 111 Languages
Get PDFHans Volker Wolf, Looi Wai Ling, Stefanie Pillai, and Adriana Phillip (eds). The Mousedeer and the Crocodiles: A Malaysian Folktale in 111 Languages. Kuala Lumpur: University of Malaya Press, 2017. xxvi + 300 pp. ISBN: 978-983-100-941-3
The development of a soft skill questionnaire for compulsory university courses based on blended learning
Get PDFThis study focuses on enrichment of soft skills elements embedded in a compulsory university course, namely, the Ethnic Relations through blended learning. A questionnaire was developed to measure the embedded soft skills elements i.e. teamwork, communication skills and problem-solving & critical thinking. A pilot study was done to test the reliability and validity of the instrument amongst first year students enrolled in the Ethnic Relations course. It also aims to measure the early stage of soft skills embedment amongst students. The questionnaire contains 5 parts, part A consist of demography information, part B on communication skills, part C on critical thinking & problem solving, part D team work skills and Part E – an open ended question on the respondents experiences and reflection. A total of 232 completed questionnaire were analysed using Statistical Package for Social Science (SPSS) version 22 and structure equation modelling (SEM). The findings of the study showed that the validity and reliability of the questionnaire was suitable in measuring the level of soft skills amongst the students