265 research outputs found

    Establishment and characterization of two human breast carcinoma cell lines by spontaneous immortalization: Discordance between Estrogen, Progesterone and HER2/neu receptors of breast carcinoma tissues with derived cell lines

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    Background: Breast cancer is one of the most common cancers among women throughout the world. Therefore, established cell lines are widely used as in vitro experimental models in cancer research.Methods: Two continuous human breast cell lines, designated MBC1 and MBC2, were successfully established and characterized from invasive ductal breast carcinoma tissues of Malaysian patients. MBC1 and MBC2 have been characterized in terms of morphology analysis, population doubling time, clonogenic formation, wound healing assay, invasion assay, cell cycle, DNA profiling, fluorescence immunocytochemistry, Western blotting and karyotyping.Results: MBC1 and MBC2 exhibited adherent monolayer epithelial morphology at a passage number of 150. Receptor status of MBC1 and MBC2 show (ER+, PR+, HER2+) and (ER+, PR-, HER2+), respectively. These results are in discordance with histopathological studies of the tumoral tissues, which were triple negative and (ER-, PR-, HER2+) for MBC1 and MBC2, respectively. Both cell lines were capable of growing in soft agar culture, which suggests their metastatic potential. The MBC1 and MBC2 metaphase spreads showed an abnormal karyotype, including hyperdiploidy and complex rearrangements with modes of 52-58 chromosomes per cell.Conclusions: Loss or gain in secondary properties, deregulation and specific genetic changes possibly conferred receptor changes during the culturing of tumoral cells. Thus, we hypothesize that, among heterogenous tumoral cells, only a small minority of ER+/PR+/HER2+ and ER+/PR-/HER2+ cells with lower energy metabolism might survive and adjust easily to in vitro conditions. These cell lines will pave the way for new perspectives in genetic and biological investigations, drug resistance and chemotherapy studies, and would serve as prototype models in Malaysian breast carcinogenesis investigations. © 2012 Kamalidehghan et al.; licensee BioMed Central Ltd

    Factors affecting the accumulation of 9-methoxycanthin-6-one in callus cultures of Eurycoma longifolia.

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    A study was conducted to improve 9-methoxycanthin-6-one productivity (potential anti-tumour compound) from callus cultures of Eurycoma longifolia (Tongkat Ali). Several factors affecting 9-methoxycanthin-6-one production in callus cultures such as different medium compositions and physical factors were investigated and analyzed. Results show that a higher production of 9-methoxycanthin-6-one (3.84 mg'g-1 DW (Dry Weight)) is obtained from callus cultured in ¼ MS basal media. At fructose of 2% (w/v), the production of 9-methoxycanthin-6-one (4.59 mg'g-1 DW) is promoted to gain the highest yield, compared to other carbon sources tested. The addition of 2.0-mg'L-1 dicamba also increases 9-methoxycanthin-6-one production (12.3 mg'g-1 DW). Higher production of 9-methoxycanthin-6-one was obtained at pH 5.5 (1.53 mg'g-1 DW). Production of 9-methoxycanthin-6-one (2.34 mg'g-1 DW) in callus cultures is also increased when the medium is added with 1×10-1 μM phenylalanine. This study suggests that the successful production of 9-methoxycanthin-6-one in vitro cultures has a potential in large-scale production using bioreactor technology

    Optical properties of diamond like carbon films prepared by DC-PECVD

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    Diamond-like carbon (DLC) thin films were deposited at different substrate temperatures using methane and hydrogen gas in DC-PECVD at 2x10-1Torr. From the light transmission using UV-VIS spectroscopy it was found that the optical transition had changed from allowed indirect transition to allowed direct transition as the substrate temperature increased. The Optical gap increased with temperature, highest of 3.034 eV was observed at 573 K, beyond which it dropped. Colour of the film changed from light brownish to a colourless transparent film in the higher temperature. The Urbach energy decreased from 1.25 eV to 0.75 eV with increasing substrate temperature till 573 K and a slight increase after it. This trend is attributed to change in sp3/sp2 ratio or change in structure. The cluster size decreases with temperature, resulting in larger band gap and the structure more ordered. Similar pattern is also witnessed in the emission spectrum of the photoluminescence

    Mathematical HOTS cultivation via online learning environment and 5E inquiry model: cognitive impact and the learning activities

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    An ideal education is the one that enhance cognitive ability. In Malaysia, educators are currently putting enormous effort to uplift higher order thinking skills (HOTS) among students at various educational levels. The advancement of technology enables educators to apply online learning environment to further catalyze the effort. Integration of correct pedagogy is essential, 5E inquiry model by Bybee was implemented to 5E online learning environment-a learning environment developed for this research. The purpose of this research is to enhance HOTS among the samples. Thus, the cognitive impact of the learning environment was studied. The current gap of the learning activities that improve HOTS was addressed by probing into the activities done by samples. Samples are thirty-three secondary school students and had treatment with the learning environment for 4 weeks. T-test conducted found that samples' HOTS statistically significant higher after treatment compared to prior to the treatment, t (32) =-20.95, p < 0.05 that indicates the treatment improve samples' HOTS. The learning activities that materialize HOTS improvement is engaging learning module and HOTS related video. This research proves that human HOTS ability can be nurtured by using technology enhanced learning environment with the appropriate pedagogical approach. Deeper fundamental research regarding the process of learning that nurture HOTS is highly recommended in the future-one of the authors is currently working on

    Effect of Contrast, Stimulus Density, and Viewing Distance on Multifocal Steady-State Visual Evoked Potentials (MSVs)

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    We investigated the effects of image contrast, stimulus density, and viewing distance upon a multifocal steady-state visual evoked potential (MSV) method. Fourteen adults with normal vision (mean age = 27.0 ± 6.6 years; 6 males) participated in the stud

    The Effect of Pleurotus sajor-caju (PSC) Addition on the Nutritional Composition and Sensory Properties of Poultry-Based Patty

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    The nutrient composition and sensory properties of poultry-based patties (PBPs) incorporated with various levels of grey oyster mushroom (Pleurotus sajor-caju, PSC) were studied. The PBPs were formulated with either 0%, 25% or 50% of fresh ground PSC. Results show poultry patty formulated with 25% PSC had protein content of 17.46% lower than the control patty which had 18.13% but it was not significant. Meanwhile, both cooked poultry patties containing 25% and 50% PSC significantly recorded lower concentration of fat at 10.67% and 7.15%, respectively. On the other hand, poultry patty added with 50% ground PSC shows the highest concentration of total dietary fibre (TDF) of 4.90 g/100g compared to poultry patty containing 25% of mushroom (3.40 g/100g) and to the control (1.90g/100g). In addition, patty incorporated with 25% PSC had moisture content of 57.91% which is significantly lower than patty formulated with 50% which had moisture of 61.80%. In the sensory evaluation, there were no differences recorded in all sensory attributes of PSC-based patties judged by untrained panelists. In conclusion, the addition of PSC to replace poultry meat can be recommended for the purpose of lowering production cost, enhancing nutritional composition and maintaining the acceptability of poultry patties

    Morphology and composition of strontium calcium aluminate matrix doped with Dy3+

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    The aim of the present study was to determine the influence of doping rare earth ion on strontium calcium aluminate (CaO-SrO-SiO2-Al2O3). Therefore, the authors have manufactured luminescent material consisting of 40CaO-5SrO-5SiO2-50Al2O3 doped with Dy3+. The compositions have been selected on the basis of chemical stability. Five pellets were prepared with different calcination temperatures and times, namely 400 and 600°C for 1 and 2 h, in order to shed light on their luminescence behaviour. X-ray diffraction, energy dispersive X-ray analysis and scanning electron microscopy elaborate and characterise the formation of small particle of photoluminescent material in the phosphor matrix host material

    Development of a risk assessment model for Oman construction industry

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    Oman as one of the Arabian Gulf countries which have invested billions of dollars in the construction industries, infrastructural services and real estate, but it is clearly identified that risk assessment was not applied for once on these awarded contracts. Lack of knowledge and awareness of risk management or assessment procedures in the construction industry in Oman caused additional cost and time delay in most of the awarded construction projects. This paper aimed at developing a model for risk assessment in the Oman construction industry to save huge amounts of millions of money wasted due to this problem. A field survey of semi-structured questionnaire with face-to-face interviews was carried out in the Oman construction industry including public, contractors and consultants. The research approach relies on data collected from primary and secondary sources. Combination of quantitative and qualitative data analysis was used in analysing the data for the Model development. The risk factors in the Oman construction industry varies from one category to another, the risk factors in government category are more than the consultant category and contractor’s category. Overall, the Oman construction industry has no very high risk factors, which means it has good opportunities for investment. It is expected that the output of this research will have a good and beneficial contribution to save time and money for both public and private sectors in Oman due to expected awareness and improvements in the risk assessment procedure

    Oil viscosity effects on lubricant oil film behaviour under minimum quantity lubrication

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    Minimum Quantity Lubrication is a great alternative to flood coolant in many perspective such as economic perspective, safety and health perspective and others. In addition, natural biodegradable oils have been widely used as lubricant oil to meet the environmental-friendly machining environment. The study of lubricant oil fundamental nature during MQL machining is highly important to really identify how the lubricant oil behaviour does affects the lubricating process. Nevertheless, the study is still scarce probably due to the complexity of experimental setup and the natural flow of the lubricant oil cannot be disrupted during the machining operation. To cater this issue, the behaviour of MQL lubricant oil was investigated so a non-intrusive method called as Laser-induced Fluorescence method is applied onto Al6061 workpiece .This research was operated by different oil viscosity represented by different oil type i.e. mixed esters oil, sunflower oil, olive oil and calophyllum inophyllum oil to analyse the lubricant oil film thickness. Overall study showed that, the average of lubricant oil film thickness were significantly decreased as the oil viscosity increased affected by the spreadability of lubricant oil onto the milled surface. At all conditions for oil viscosities, the lubricant oil film showed similar downturn trend due to rise up of built-up edge formation and chips accumulation towards the milling point. Hence, the effects of MQL system parameter on the machining performance has been clarified in details through the observation on the MQL lubricant behaviour

    Faktor penggunaan e-pembelajaran di kalangan pelajar sarjana teknologi pendidikan Universiti Teknologi Malaysia

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    The purpose of this study is to study the frequency of e-Learning usage as well to study its usage factors. The research instrument being uses is a set of questionnaire containing three sections which are sample demographic, e-Learning usage frequency, and e-Learning usage factors. About 70 samples undergoing Educational Technology Educational Master Degree in Faculty of Education, Universiti Teknologi Malaysia, Johor Bahru had involved in this research. E-Learning usage factors are divided into four which are technology factor, exposure factor, content factor and social influence factor. The Alpha Cronbach’s value retrieved from the reliability test for the questionnaire instrument is 0.8806. Research finding shows the frequency of application usage in e-Learning at a moderate level which having the mean value of 2.49. Lastly, a number of recommendations has been put forward to the relating party for further action
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