Green tea polyphenol-reduced graphene oxide: derivatisation, reduction efficiency, reduction mechanism and cytotoxicity

This paper reports on the derivatisation, reduction efficiency, reduction mechanism and cytotoxicity of green tea polyphenol-reduced graphene oxide (GTP-RGO). The reduction of graphene oxide (GO) at 90°C using a weight ratio (WR) of GTP/GO=1 resulted in the production of a stable GTP-RGO dispersion in aqueous media, as indicated by the results of ultravioletvisible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and the measurement of zeta potential and electrophoretic mobility. In addition, the results from UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis indicated the comparable reduction ability of GTP relative to the standard reducing agent, hydrazine (N2H4). The removal mechanism of epoxy group from GO via reduction reaction with GTP was investigated by implementing hybrid functional method of Becke-3-parameters-Lee-Yang-Parr (B3LYP)using Gaussian 09 software. The energy and frequency calculations showed that the GO reduction using GTP was more spontaneous and relatively took place faster than the reduction using N2H4, as evidenced by higher entropy change (ΔS) (0.039 kcal/mol·K) and lower Gibbs free energy (ΔG) barrier (58.880 kcal/mol).The cytotoxicities of GO and GTP-RGO samples were evaluated against human colonic fibroblasts cells (CCD-18Co). The GO sample was determined to be toxic even at low concentration (6.25 μg/mL), while the GTP-RGO sample possesses notably low toxicity at the same concentration. The cell culture experiments revealed that the incorporation of GTP led to a decrease in the toxicity of GTP-RGO samples

Pengaruh Penilaian Kinerja Perusahaan terhadap Return Saham

Penelitian ini bertujuan untuk melihat apakah terdapat pengaruh Penilaian kinerjaPerusahaan yang diukur dengan rasio PER terhadap return saham. Metode penelitian inimenggunakan metode kuantitatif. Pengujian hipotesis dilakukan menggunakan modelregresi. Sampel menggunakan Perusahaan terbaik menurut OJK pada tahun 2013 danmengambil data Perusahaan tersebut dalam kurun waktu selama 2009-2013. Hasilpenelitian ini memberikan bukti empiris bahwa kinerja Perusahaan yang diproksi denganrasio PER berpengaruh positif dan signifikan terhadap Return Saham

Aplikasi E-Commerce Sebagai Jembatan Perancang Dan Konsumen Pada T-Shirt Design

— In Indonesia, there is still not a special website that accommodates designers to design, to sell t-shirts with their own design, most websites only sell t-shirts. Abroad, some websites have been selling design t-shirts such as Teespring. Teespring makes it easy to create, sell, and order custom t-shirts, but has the disadvantage that the price is less affordable for the people of Indonesia. T-Shirt Design is an e-commerce website that makes it easy to create, sell and order custom t-shirts with affordable prices. T-Shirt Design embraces designers as sellers with their own design products and accomodate selling their custom t-shirts. T-Shirt Design will process orders from designer/seller and display t-shirt products that have ready to sell to consumer. Consumer can order, buy t-shirt product, and pay it. After receiving the product, consumer will give the feedback that use to improve serving, accuration, expedition. Designer/Seller get selling report, inventory report and list of consumer for each shop. Keywords—Custom T-Shirt, E-commerce, T-Shirt Desig

Development of a Multimedia Courseware as a Teaching Aid for Children with Dyslexia

Dyslexia is a language based learning disability resulting in people experiencing difficulties in reading, spelling, writing and speaking. These problems are sometimes compounded by short term memory difficulties, a lack of organisational skills and time management issues which all have an impact on learning. This paper focuses on the planning, analysis and design of an e-learning courseware to teach dyslexics to read using the ‘picture thinking’ model. The development of this e-learning courseware involves transforming the traditional content of printed books from passive prints and illustrations into interactive multimedia content. The interactive multimedia content will focus on clear presentation of materials, good navigational assistance and a variety of multimedia options to tap into visual, auditory and kinaesthetic skills to support dyslexics. The targeted users will be children with dyslexia and pre-schoolers aged 5 to 7 learning to read Bahasa Melayu. A successful implementation of this courseware will be useful to the dyslexic learners as it will use picture thinking model and multisensory approach to the best of their ability instead of approaching them with the same teaching approaches used to teach their non- dyslexic counterparts

Pemanfaatan Limbah Plastik Simpul Sebagai Pengganti Agregat Kasar Pada Beton

HDPE or High Density Polyethylene is a type of white plastic milk / white. Used for pocket tissue, detergent bottles, oil, anti-heat plastic, plastic pipes, plastic shopping bag and a regular bag for vegetable food as flexible with high strength. This plastic is non-degregdable, so it needs special attention to handle these types of plastic waste. Therefore, in this study used HDPE plastic waste created node types to be used as a substitute for gravel coarse aggregate in concrete. The study was conducted on concrete with coarse aggregate to subtitude made from waste plastic bags made of HDPE node types with higher levels of 0%, 50% and 100% of the volume of broken stone. Mix proportions used is the ratio of volume 1 PC: 2 Fine aggregate: 2 coarse aggregate. Analysis on testing coarse aggregate made from waste plastic bags made of HDPE knot types obtained specific gravity of 0.570, loose bulk density of 0.24 gram/cm3 and solid content of 0.3 weight gram/cm3. The aggregate categorized as mild as it has a specific gravity by B

The Adoption of E-learning 2.0 in Higher Education by Teachers and Students: An investigation using Mixed Methods Approach

This paper describes an approach to investigate the adoption of Web 2.0 in the classroom using a mixed methods study. By using a combination of qualitative or quantitative data collection and analysis techniques, we attempt to synergize the results and provide a more valid understanding of Web 2.0 adoption for learning by both teachers and students. This approach is expected to yield a better holistic view on the adoption issues associated with the e-learning 2.0 concept in current higher education as opposed to single method studies done previously. This paper also presents some early findings of e-learning 2.0 adoption using this research method

Role of vascular endothelial growth factor (VEGF) in diagnosis of pleural effusion of different origins

AbstractBackgroundThe undiagnosed pleural effusions are an important clinical problem so scientists spent much effort and time in searching for a new parameter to help in the diagnosis of pleural effusions. Vascular endothelial growth factor (VEGF) helps in differentiation between malignant and inflammatory pleural effusions and might play an important role in tumor progression and the formation of malignant effusions.Aim of the workTo determine the level of pleural fluid VEGF in order to evaluate its value as a marker for differentiation between different types of pleural effusions.Subjects and methodsThe present study was conducted on 73 patients with pleural effusion, admitted to Kasr Elaini Hospital (Chest Department) during the period from August 2011 to October 2012, after having their written consent. All patients were subjected basically to full history taking, thorough clinical examination, routine laboratory investigations, plain chest radiography thoracentesis. Medical thoracoscopy was carried out for cases with undiagnosed exudative pleural effusion (n=46).ResultsPleural fluid VEGF, and pleural fluid VEGF/serum VEGF ratio both are highest in malignant pleural effusion with statistically high significance (p<0.001), followed by infectious effusion then tuberculous one. Using ROC curve analysis, the cut-off used for VEGF in pleural fluid in discriminating malignant from other groups is 1800pg/ml with sensitivity of 95% and specificity of 96%.ConclusionVEGF is highest in malignant pleural effusion. The differential diagnosis of effusions might be further improved by including vascular endothelial growth factor concentrations into the diagnostic armentarium available to the clinician