565 research outputs found

    A practical approach to synthesize polyamide thin film nanocomposite (TFN) membranes with improved separation properties for water/wastewater treatment

    Get PDF
    TFN membranes containing 0.05 or 0.10 w/v% surface-functionalized TNTs in a PA selective layer were synthesized for better performances in water/wastewater treatment.</p

    Demographics Characteristics and Analysis of Malocclusions of Orthodontic Patients Seen at IIUM Dental Specialist Clinic, Kuantan, Pahang

    Get PDF
    Introduction: Malocclusion is one of the most common dental problems observed. Limited data is currently available regarding the demographics of malocclusion observed locally. Materials And Methods: This is a retrospective study where 770 patients were recruited from May 2009 till December 2014. 560 orthodontic study models that met the inclusion criteria were examined and the malocclusions were classified according to the British Standard Institute (BSI) incisor classification.&nbsp; Demographic pattern and their relationship were analysed by structural equation modelling using SPSS (version 23.0). Results: From 560 study models analysed, 72% were female. The age of the patients ranges from 7-12 years old (17.1%), 13-17 years old (55.9%) and &gt;18 years old (27.0%). Majority of the patients were Malay followed by Chinese (5.7%), Indian (1.8%) and other races (1.8%) Treatments received were fixed appliances (FA) (60.0%), removable appliances (RA) (12.5%), functional appliances (FnA) (1.1%), combination of RA and FA (16.1%), combination of FnA and FA (2.1%) and consultation (8.2%). Types of malocclusions observed were Class I (25.7%), Class II/1(32.7%), Class II/2 (7.5%) and Class III (34.1%). There was significant association (p&lt;0.05) between age and gender towards the types of malocclusions and treatments received were observed. Conclusion: Age and gender play significant role in determining the types of treatment received by patients with malocclusion. Data obtained will be beneficial for departmental future management and clinical planning.&nbsp

    Developing argumentation skills in mathematics through computer-supported collaborative learning: the role of transactivity

    Get PDF
    Collaboration scripts and heuristic worked examples are effective means to scaffold university freshmen’s mathematical argumentation skills. Yet, which collaborative learning processes are responsible for these effects has remained unclear. Learners presumably will gain the most out of collaboration if the collaborators refer to each other’s contributions in a dialectic way (dialectic transactivity). Learners also may refer to each other’s contributions in a dialogic way (dialogic transactivity). Alternatively, learners may not refer to each other’s contributions at all, but still construct knowledge (constructive activities). This article investigates the extent to which constructive activities, dialogic transactivity, and dialectic transactivity generated by either the learner or the learning partner can explain the positive effects of collaboration scripts and heuristic worked examples on the learners’ disposition to use argumentation skills. We conducted a 2 × 2 experiment with the factors collaboration script and heuristic worked examples with N = 101 math teacher students. Results showed that the learners’ engagement in self-generated dialectic transactivity (i.e., responding to the learning partner’s contribution in an argumentative way by critiquing and/or integrating their learning partner’s contributions) mediated the effects of both scaffolds on their disposition to use argumentation skills, whereas partner-generated dialectic transactivity or any other measured collaborative learning activity did not. To support the disposition to use argumentation skills in mathematics, learning environments should thus be designed in a way to help learners display dialectic transactivity. Future research should investigate how learners might better benefit from the dialectic transactivity generated by their learning partners

    Interference management for moving networks in ultra-dense urban scenarios

    Get PDF
    The number of users relying on broadband wireless connectivity while riding public transportation vehicles is increasing significantly. One of the promising solutions is to deploy moving base stations on public transportation vehicles to form moving networks (MNs) that serve these vehicular users inside the vehicles. In this study, we investigated the benefits and challenges in deploying MNs in ultra-dense urban scenarios. We identified that the key challenge limiting the performance of MNs in ultra-dense urban scenarios is inter-cell interference, which is exacerbated by the urban canyon effects. To address this challenge, we evaluated different inter-cell interference coordination and multi-antenna interference suppression techniques for MNs. We showed that in using MNs together with effective interference management approaches, the quality of service for users in vehicles can be significantly improved, with negligible impacts on the performance of regular outdoor users

    Elemental hydrochemistry assessment on its variation and quality status in Langat River, Western Peninsular Malaysia.

    Get PDF
    This paper discusses the hydrochemistry variation and its quality status in Langat River, based on the chemistry of major ions, metal concentrations and suitability for drinking purposes. Water samples were collected from 30 different stations to assess their hydrochemical characteristics. The physico-chemical parameters selected were temperature, electrical conductivity, total dissolved solids (TDS), salinity, dissolved oxygen , pH, redox potential, HCO3, Cl, SO4, NO3, Ca, Na, K, Mg, 27Al, 138Ba, 9Be, 111Cd, 59Co, 63Cu, 52Cr, 57Fe, 55Mn, 60Ni, 208Pb, 80Se and 66Zn to investigate the variation of the constituents in the river water. Most of the parameters comply with the Drinking Water Quality Standard of the World Health Organization and the Malaysian National Standard for Drinking Water Quality by the Malaysia Ministry of Health except for EC, TDS, Cl, HCO3, SO4, Na, Mg, Al, Fe and Se. The results show that the Langat River is unsuitable for drinking purposes directly without treatment

    Efficient Photoelectrochemical Performance of Gamma Irradiated gC3N4 and its g-C3N4@BiVO4 Heterojunction for Solar Water Splitting

    Get PDF
    This is the author accepted manuscript. The final version is available from the American Chemical Society via the DOI in this recordComprehensive experimental and density functional theory simulations have been performed for the enhanced photoelectrochemical performance of gamma irradiated g-C3N4 and its heterojunction with BiVO4. The structure and morphology of g-C3N4@BiVO4 as a heterojunction were analyzed and verified from the correlation of experimental and theoretical data. It is found that gamma radiations have changed the bonding structure of g-C3N4 which ultimately reduces the optical bandgap energy. Moreover, the performance of gamma-irradiated g-C3N4 is two-fold, compared to that of non-irradiated one; increases from 3.59 to 5.86 µAcm-2 at 1.23 V versus Ag/AgCl in 0.5 M Na2SO4 electrolyte solution (pH 7). Finally, it is observed that the performance of gamma irradiated g-C3N4 in g-C3N4@BiVO4 heterojunction increased from 0.53 mA cm-2 to 1.38 mA cm-2, compared to that of the non–irradiated one. In summary, it has been concluded that gamma-irradiated g-C3N4 and its heterojunction is potentially be applied in PEC solar water splitting.National University of Malaysi

    Safety of trastuzumab (Herceptin®) during pregnancy: two case reports

    Get PDF
    We report on two cases of women on trastuzumab therapy for breast cancer who became pregnant and delivered healthy live infants. At the time of reporting the children are growing and developing normally (ages 3 and 2)

    Body mass index and dental caries in children and adolescents : a systematic review of literature published 2004 to 2011

    Get PDF
    The objectiveThe authors undertook an updated systematic review of the relationship between body mass index and dental caries in children and adolescents.MethodThe authors searched Medline, ISI, Cochrane, Scopus, Global Health and CINAHL databases and conducted lateral searches from reference lists for papers published from 2004 to 2011, inclusive. All empirical papers that tested associations between body mass index and dental caries in child and adolescent populations (aged 0 to 18 years) were included.ResultsDental caries is associated with both high and low body mass index.ConclusionA non-linear association between body mass index and dental caries may account for inconsistent findings in previous research. We recommend future research investigate the nature of the association between body mass index and dental caries in samples that include a full range of body mass index scores, and explore how factors such as socioeconomic status mediate the association between body mass index and dental caries.<br /

    Improving ‘lipid productivity’ in microalgae by bilateral enhancement of biomass and lipid contents: A review

    Full text link
    © 2020 by the authors. Licensee MDPI, Basel, Switzerland. Microalgae have received widespread interest owing to their potential in biofuel production. However, economical microalgal biomass production is conditioned by enhancing the lipid accumulation without decreasing growth rate or by increasing both simultaneously. While extensive investigation has been performed on promoting the economic feasibility of microalgal-based biofuel production that aims to increase the productivity of microalgae species, only a handful of them deal with increasing lipid productivity (based on lipid contents and growth rate) in the feedstock production process. The purpose of this review is to provide an overview of the recent advances and novel approaches in promoting lipid productivity (depends on biomass and lipid contents) in feedstock production from strain selection to after-harvesting stages. The current study comprises two parts. In the first part, bilateral improving biomass/lipid production will be investigated in upstream measures, including strain selection, genetic engineering, and cultivation stages. In the second part, the enhancement of lipid productivity will be discussed in the downstream measure included in the harvesting and after-harvesting stages. An integrated approach involving the strategies for increasing lipid productivity in up-and down-stream measures can be a breakthrough approach that would promote the commercialization of market-driven microalgae-derived biofuel production

    Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

    Get PDF
    BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112
    corecore