19672 research outputs found
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Microstructural investigation and durability performance of high volume industrial by-products-based masonry mortars
No full textThe use of eco-efficient building materials in construction has become a trend in regard to the effort of mitigating the effect of global warming which include CO2 emission, energy demand, and natural resources depletion that lead to negative environmental impacts. The present study was attempts to investigate the microstructure behaviour and durability performance of masonry mortars. In this context, palm oil clinker powder (POCP) was utilised to replace cement up to 80%, while the incinerated bottom ash aggregates (IBAA) was utilised to replace mining sand up to 100%. Eventually, further investigation was carried out on the durability performance through water absorption, sorptivity, sulphate attack, and electrical resistivity on the ideal mixtures of 40% of POCP (CLP) and IBAA with 50% (CLPI50) & 100% (CLPI) mixtures. As a result, irregular shape of POCP particles in SEM and the presence of high silica in POCP were observed to produce the peaks of portlandite as well as early occurrence of calcite. In this case, IBAA particles have angular, while porous microstructure in SEM and the XRD results showed high peaks of quartz and calcite. The final mixes containing CLP, CLPI50, and CLPI respectively obtained 51, 56, and 61% of 28-day compressive strength of control mix (CL) that was greater than the requisite 12.4 MPa. On another note, the mix- CLP showed better durability performance (6% water absorption, 84 mm/100 cm2 of IRA) compared to CLPI50 (7%, 89 mm/100 cm2), while the drying shrinkage performance of CLP possessed similar trend to that of the CL (0.064%). Finally, the mix CLP managed to produce extremely good electrical resistivity
The influence of self-drive on the development of Malay language programme: Non-native adults’ perspective
No full textPurpose: The purpose of the study is to analyse non-native adults’ self-drive and ways that has influenced towards the development of Malay language programme in which the programme caters to their needs, expectations and self-drive in University of Malaya for Continuing Education. Methodology: This study aims to analyse non-native adults’ self-drive in an informal adult education at a higher learning institution in Malaysia using an action research method comprising 58 non-native adult learners which was implemented from January 2014 to December 2017. The evidence gathered through feedback, observation and continuous assessment. Findings: The outcome of this study reveals that strong self-drive among non-native adult learners encouraged and increased the effort towards the introduction of a Malay language programme that suits their needs and expectations. Research Limitations/Implications: It was reported that the development of new Malay programme would have been more successful and benefits more language instructors and academicians. Their involvement would provide more support and critical views in the research in order to validate the formulation of the Malay programme. Social Implications: The improvement in teaching and learning process undertaken has also accelerated adult learners’ attainment and competency in Malay language. As a result of non-native adult leaners’ excellent attainment has reinforced the Malay language educator to attract and increase the enrolment for continuing education at higher learning institutions that offer Malay programme as lifelong learning programme. Originality/Value: The study on self-drive among non-native adults and how it has influenced towards the development of a Malay programme that caters to their needs, interests and expectations is still new, and it is a first-hand study of its kind. The results will be useful for those who are involved in adult teaching and in steering Malay as Modern Foreign Language programme at higher education
Measuring Human Capital in Small and Medium Manufacturing Enterprises: What Matters?
No full textThis study proposes a framework that quantifies and integrates both the tangible and intangible aspects of HC to comprehensively measure the overall level of human capital index (HCI) in small and medium manufacturing enterprises (SMEs). Data were collected from 100 SME experts through the use of questionnaires in two stages. The data collected were first, used for selection purpose, and second, for the prioritization of relevant dimensions and sub-dimensions of HC. The analytic hierarchy process was adopted to prioritize and assign dimension and sub-dimension weights to HC to derive the HCI. The results indicate that not all dimensions and sub-dimensions of HC are important for the HCI. Namely, the HCI can be best represented by 9 dimensions and 35 sub-dimensions of HC. The core dimensions are experience, skills, education, abilities and training. Indeed, within experience, the main sub-dimensions are work-related experience and organizational tenure. The results suggest the importance of experience relative to skills and education. The proposed framework can also be applied to derive industry specific HCI
Caffeoylquinic acids induce cell death and cell cycle arrest on HCT 116 cells via formation of extracellular H2O2and quinones
No full textCaffeoylquinic acids are frequently present in variety of medicinal plants, fruits, vegetables and beverages. These phenolic acids are widely accepted as antioxidants but have pro-oxidant activity under certain condition. The cell death and cell cycle arrest on HCT 116 human colon carcinoma cells were observed by flow cytometry when treated with 5-O-caffeoylquinic acid (CQ) and 3,5-dicaffeoylquinic acid (DCQ) at 1 and 2 mg/ml. The addition of cell impermeable catalase and reduced glutathione (GSH) could protect HCT 116 cells from cell death and cell cycle arrest effect of CQ and DCQ. It was observed that CQ and DCQ generated extracellular hydrogen peroxide (H2O2) and quinones in the culture medium. These in vitro data showed that caffeoylquinic acids have to undergo oxidative mechanism in order to induce anti-proliferation effect on colon cancer cells and this may be beneficial in prevention or treatment of colorectal cancer
Effect of Piezoelectric Sutural Ostectomies on Accelerated Bone-Borne Sutural Expansion
No full textPurpose
The present study investigated the effect of piezoelectric sutural ostectomies on accelerated bone-borne sutural expansion.
Materials and Methods
Sixteen male New Zealand white rabbits (20 to 24 weeks old) were randomly divided into 4 experimental groups (n = 4): group 1, conventional rapid sutural expansion; group 2, accelerated sutural expansion; group 3, accelerated sutural expansion with continuous ostectomy; and group 4, accelerated sutural expansion with discontinuous ostectomy. All sutural ostectomies were performed using a piezoelectric instrument (Woodpecker DTE, DS-II, Guangxi, China) before expander application with the rabbits under anesthesia. Modified hyrax expanders were placed across the midsagittal sutures of the rabbits and secured with miniscrew implants located bilaterally in the frontal bone. The hyrax expanders were activated 0.5 mm/day for 12 days (group 1) or with a 2.5-mm initial expansion, followed by 0.5 mm/day for 7 days (groups 2 to 4). After 6 weeks of retention, the bone volume fraction, sutural separation, and new bone formation were evaluated using micro-computed tomography and histomorphometry. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U tests and Spearman's rho correlation (P < .05).
Results
Ranking of the median sutural separation was as follows: group 1, 3.05 mm; group 2, 3.97 mm; group 4, 4.78 mm; and group 3, 5.66 mm. The least and most bone formation were observed in groups 1 (63.63%) and 3 (75.93%), respectively. Spearman's correlation showed a strong, positive, and significant correlation (r = 0.932; P < .01) between the new sutural bone formation and amount of sutural separation.
Conclusions
Piezoelectric sutural ostectomies increased the rate of sutural separation and promoted new sutural bone formation/osteogenesis. Continuous ostectomy gave better results than discontinuous ostectomy
Crouzon Syndrome: A Case Series of Craniomaxillofacial Distraction Osteogenesis for Functional Rehabilitation
No full textCrouzon syndrome (CS) is the most common craniosynostosis syndrome and requires a comprehensive management strategy for the optimization of care and functional rehabilitation. This report presents a case series of 6 pediatric patients diagnosed with CS who were treated with distraction osteogenesis (DO) to treat serious functional issues involving severe orbital proptosis, an obstructed nasopharyngeal airway, and increased intracranial pressure (ICP). Three boy and 3 girls were 8 months to 6 years old at the time of the operation. The mean skeletal advancement was 16.1 mm (range, 10 to 27 mm) with a mean follow-up of 31.7 months (range, 13 to 48 months). Reasonable and successful outcomes were achieved in most patients as evidenced by adequate eye protection, absence of signs and symptoms of increased ICP, and tracheostomy tube decannulation except in 1 patient. Complications were difficult fixation of external stabilizing pins in the distraction device (n = 1) and related to surgery (n = 4). Although DO can be considered very technical and can have potentially serious complications, the technique produces favorable functional and clinical outcomes in treating severe CS. (C) 2017 American Association of Oral and Maxillofacial Surgeon
All-carbon suspended nanowire sensors as a rapid highly-sensitive label-free chemiresistive biosensing platform
No full textNanowire sensors offer great potential as highly sensitive electrochemical and electronic biosensors because of their small size, high aspect ratios, and electronic properties. Nevertheless, the available methods to fabricate carbon nanowires in a controlled manner remain limited to expensive techniques. This paper presents a simple fabrication technique for sub-100 nm suspended carbon nanowire sensors by integrating electrospinning and photolithography techniques. Carbon Microelectromechanical Systems (C-MEMS) fabrication techniques allow fabrication of high aspect ratio carbon structures by patterning photoresist polymers into desired shapes and subsequent carbonization of resultant structures by pyrolysis. In our sensor platform, suspended nanowires were deposited by electrospinning while photolithography was used to fabricate support structures. We have achieved suspended carbon nanowires with sub-100 nm diameters in this study. The sensor platform was then integrated with a microfluidic chip to form a lab-on-chip device for label-free chemiresistive biosensing. We have investigated this nanoelectronics label-free biosensor's performance towards bacterial sensing by functionalization with Salmonella-specific aptamer probes. The device was tested with varying concentrations of Salmonella Typhimurium to evaluate sensitivity and various other bacteria to investigate specificity. The results showed that the sensor is highly specific and sensitive in detection of Salmonella with a detection limit of 10 CFU mL−1. Moreover, this proposed chemiresistive assay has a reduced turnaround time of 5 min and sample volume requirement of 5 µL which are much less than reported in the literature
Five decades of scientific development on "attachment theory": Trends and future landscape
No full textAttachment Theory is one of the most frequently used frameworks which revolutionised the understanding of human behaviour, from early childhood to adulthood. Attachment Theory's scholarly output was examined using a quantitative bibliometric approach, based on rigorous facts extracted from the WoS databases from 1970 to 2017. Overall, 1,700 documents in the category "Psychology" with the topic "Attachment Theory" were analysed to find trends of publications, networking coupling, keywords frequencies, top authors, and highly cited papers. A qualitative content analysis of the top 20 documents with the highest average citation per year was done to provide insight on document approaches. The results show that the scientific productivity in "attachment theory" is highly skewed. The authors recommend publishing attachment theory related articles in an open access journal. There is a need for further interdisciplinary research and practice collaboration to move beyond the sole psychological approach and realise the importance of multi-disciplinary approaches
Potential of field crickets meal (Gryllus bimaculatus) in the diet of African catfish (Clarias gariepinus)
No full textThis study was conducted to evaluate the effect of dietary replacement of fishmeal (FM) by using field crickets (CM) and on growth performance and feed utilization of African catfish fingerlings. Five isonitrogenous diets (28% crude protein) were used containing 0% (control), 25%, 50%, 75% or 100% of FM substituted by CM. Triplicate group of fish (n = 15) were fed with their respective diets with initial mean body weight (BW) of 4.00 ± 0.8 g (mean ± SE) for 56 days. Fish fed with 100% CM exhibited significantly lower food conversion ratio than the lower inclusion level. Values of specific growth rate and protein efficiency ratio increased gradually with increasing amount of CM inclusion level from 50% to 100%. All compounds of essential amino acids were present in experimental diets although methionine, lysine and tryptophan were comparatively less than the required amount of amino acid for African catfish. Whole-body crude protein composition was significantly higher in fish fed with diet 50% to 100% CM compared to initial fish. These results indicated that CM is capable of serving as an alternative protein replacement for FM in the diet of farmed African catfish up to 100% without affecting body composition and feed utilization
Trophic discrimination factor and the significance of mangrove litter to benthic detritivorous gastropod, Ellobium aurisjudae (Linnaeus)
No full textIn stable isotope analysis, the estimation of proportional contribution of carbon and nitrogen from mangrove to benthic invertebrates requires knowledge of the food-consumer trophic discrimination factor (∆ δ13C and ∆ δ15N). This study tested the hypothesis that the mangrove gastropod Ellobium aurisjudae can assimilate low quality refractory mangrove litter and aimed to determine the trophic discrimination values (TDV) of C and N isotopes between gastropod and the mangrove producer. The mean ∆ δ13C for gastropods fed senescent leaves of the mangrove Bruguiera parviflora (Roxb) Wight & Arn and decomposing mangrove (unknown species from the same site) wood were estimated at 5.3 ± 0.3‰ and 3.2 ± 0.5‰ respectively, whereas for ∆ δ15N, these values were 4.2 ± 0.2‰ and 6.0 ± 0.2‰ respectively. The gastropod assimilated refractory carbon from mangrove leaf and wood litter with 49% and 18% efficiency respectively. Rearing experiment of gastropods (n = 25) fed only mangrove wood litter over 5months in the laboratory, showed mean weight increments of 14.8–74.4% depending on the initial animal weight. Significant deviation of the TDVs for E. aurisjudae from the generalized discrimination values for herbivory underscores the need to use specific TDV for the detritivory link