Antioxidant and antiproliferative activities of Malaysian sea cucumber, (Holothuria edulis Lesson), extracts

Sea cucumber is a marine invertebrate of the phylum Echinodermata and the class Holothuroidea that found on the sea floor worldwide. In Asia, many of sea cucumber species are considered as traditional food items and have been used in featment of numerous diseases such as eczema, arthritis and hypertension. Previous scientific studies have shown multiple biological activities of sea cucumber species as antinociceptive, antimicrobial and antifungal properties. This study was conducted to investigate the antioxidant and antiproliferative activities of aqueous and organic extracts from sea cucumber, Holothuria edulis. Two different free radical systems were used to evaluate antioxidant activity of H. edulis, stable radical l,l-diphenyl-2- picrylhydrazyl (DPPH.) and linoleic acid free radical mediated p-carotene bleaching. In addition, Folin-Ciocalteau reagent was used to determine the total phenolic content of the exfacts. The inhibitory effect of the exfacts on proliferation of MCF-7 (human breast adenocarcinoma) and TEI (Human esophageal squamous cell carcinoma) human cancer cell lines were demonstrated by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Our data showed that the gallic acid equivalent (GAE) of the total phenolic content in aqueous extract (GAE : 7.33 mglg) is higher than an organic extact (GAE = 2.17 mglg). An aqueous extract also exhibited higher.antioxidant capacity by using DPPH assay (ICso = 2.04 mg/ml vs. 8.73 mlmL in organic extract), as well as by using p-carotene bleaching assay (Antioxidant Activity : 42.69 %o vs. 28.52 % in organic extract). On the other hand, an organic extact showed higher antiproliferative effect against MCF-7 and TEI cancer cells, giving ICso : 28.0 and 17.5 pdmL, respectively than aqueous extract, that gave ICso : 133.0 pilmL against MCF- '7 and76.0 pgmL against TEl. In conclusion, frndings of this study revealed that H. edulis as a promising source ofnatural antioxidants and anticancer products

Delaminating control on drilling the medium density fiber board with robust optimization

Drilling the medium density fiber (MDF) board always emerge the occurrence of delaminating, as the unwanted result of the process. The defect will moderate the aesthetical value of the finished products particularly if the product is a furniture product. This work optimizes the control factor of delamination using robust engineering technique founded by Genichi Taguchi, father of robust engineering. The optimum drilling parameter which based on smallest the better is optimized and it is confirmed by the confirmation experiment that the imperfections is minimized. Three control factors are investigated in the study: feed rate, cutting speed, and drill bits diameter. The response plot of the control factor shows a drill bit diameter is the highest contributing control factor that influences delaminating as the different of the robustness is 2.047 dB. The optimum parameter shows that the variability of the noise factor is improved as compared to the initial parameter by means of the dB gain of 1.308 dB and 1.451 dB for the prediction and confirmation respectively. The robust assessment of the optimization has indicates that the drilling parameter is less sensitive to the noise factor

Analysis of surface deformation under static and ultrasonic compression of aluminium

The quantitative assessment of the topographic features of surfaces is important for interpreting a wide variety of problems in surface contact. The mechanism of friction depends on the nature of the real contact between die and specimen interface and also upon the distributions, sizes and shapes of the asperities. Measurement of these features provides an essential insight into the contact friction. In this present study, the ring aluminium specimens were initially compressed under static upsetting, longitudinal ultrasonic (LU) and radial ultrasonic (RU) vibration applied on the lower die. Five different lubrication conditions were appiled to investigate the effects of friction in the ring compression test: dry surface, chemically pure oleic acid, Lubrodal, Molyslip, and a thin soft solid film of PTFE (polytetrafluoroethylene). This ring test was purposely carried out in our previous work to estimate the coefficient of friction between die and specimen. Subsequently the surface texture of the deformed aluminium ring specimens was assessed by a roughness measurement and topographic evaluation. To evaluate the surface, two common surface evaluation procedures were carried out; (1) Surface roughness measurement using a 2D-profilometer and, (2) surface topographic imaging using scanning electron microscopy (SEM). It was expected that these measurement could provide some further evidence or explanations of the coefficients of friction measured in the LU and RU ring tests. It was observed that the roughness of each surface has been well correlated with its surface texture. Generally, for all compression methods, a smoother surface was achieved by using dry and liquid lubricants and a rougher surface was presented by using Molyslip and PTFE. The application of the ultrasonic excitation during a compression test was effectively to reduce the surface roughness for dry and liquid lubricants. However for the surfaces that were coated with Molyslip and soft solid film of PTFE, the LU and RU loadings created an uneven surface texture. Keywords: Surface analysis, SEM, Ultrasonic compression, Ring test, Frictio

Human factor issue in quality management

Quality management is very important in every business to ensure success of the business. As promoted by many quality experts, people are the most important factor in assuring quality of products and services. Managing human factors has significant impact on the quality performance of an organization. In this study, deterioration human factors management was identified as main contribution of the high number of customer complaints in a electronic packaging company. A survey was conducted among the target departments to determine the reasons of the deterioration in human factors and to identify the area for improvement. Pareto chart was used to prioritize the area for improvement. Human factors are important elements of quality management, therefore regular assessment, review and continuous improvement are required

Conceptual knowledge in three dimensional computer aided design (3D CAD) modeling: a literature review and conceptual framework

The advancement of computing technology and widespread adoption on the use of 3D CAD modeling system has led the development of techniques and approaches to facilitate learning of relevant techniques in virtual modeling. This paper presents a review of literature on knowledge representation in CAD and proposed a new framework of conceptual knowledge in 3D CAD modeling. Findings of studies reviewed suggest that conception of knowledge representation in 3D CAD modeling has been dominated by approaches stressing on the development of a model within a single platform, not on variations of the modeling techniques and the way the system is used. A new knowledge representation in 3D CAD modeling is proposed to assist students to become a capable engineer

The dynamics of daylighting at a residential college building with the internal courtyard arrangement

Dayasari residential college building was designed with the internal courtyard that allows for numerous implementations of bioclimatic design strategies, especially on daylighting. The field measurement was conducted at eight unoccupied student rooms, selected as samples to represent ten scenarios and orientations that concerned with the level of radiation and penetration of sunlight. This study reveals the contribution of the internal courtyard in the residential college which allows the daylight penetration at the corridor areas and interior of the rooms through the transom over the entrance door, up to ten hours daily. Different amounts of daylight were measured in specific room scenarios to suggest on the most comfortable indoor living space. The recorded mean value for indoor varied from 37 to 286 lux, while in the corridor area 192 to 3,848 lux. However, the use of the large overhangs over the windows, wall openings in the room and trees with large canopy in the landscape setting should critically justify when the adequacy of daylight was drastically reduced in certain rooms

Statistics for sciences and engineering

Statistics for Sciences and Engineering is a textbook that emphasizes statistical concepts and applications. All major aspects of statistic for sciences and engineering are covered including descriptive statistics, probability and probability distributions, statistical tests and confidence intervals for one and two samples, building regression models, one-way classification and analyzing contingency tables. To ensure that the content presented in this book is consistent with the future workplace environment, Microsoft Excel intruction is integrated within chapters one, six, seven and eight. This plays an integral part in providing an application orientation

The Malay dilemma on organ donation in Malaysia

Organ donation among the world community today is not a new phenomenon.The noble act of organ donation by donors that at times, has no blood relations has enabled many patients with chronic diseases to earn a second chance in life. The same scenario also takes place in Malaysia in which awareness of organ donation to help parties in need is not new.Many citizen of Malaysia is aware that their contribution gives "new life" to the needy.This little “scarifies” indirectly shows that Malaysian people put a high value for the social development in their country.The Malays in Malaysia is the largest ethnic group, but unfortunately, the statistics show that the Malays are the least to sign up for organ donation.Thus, the objective of this study is to identify the causes that prevented them from doing so. This study was conducted by taking into account three factors; religion, awareness, as well as perception or views on organ donation willingness among the Malays.Of the three factors studied, only two significant factors contributed to the main question of why the Malays shy away from organ donation and they are religion and perception.This shows that the Malays are aware that organ donation is a noble practice, but limited perception and knowledge of religion limit their participation.Therefore, it is recommended that a comprehensive discussion among religious leaders in changing the perception and explain the laws of religion on the issue of organ donation is carried out continuously in various mediums so that the awareness of the Malays in organ donation can be fully utilized for the benefit of everyone

Study on methanolic extracts of Nuclea subdita (Korth) steud. Heartwood parts for the total phenolic contents and free radical scavenging activities

The present study investigated the Total Phenolic Content (TPC) and free radical scavenging activity of Nauclea subdita (Korth) Steud. which might reflect the potency of the plant extract as antioxidant. Young and matured trees of N. subdita were harvested and cut into three heartwood parts (top, middle and bottom) and grounded into powdered forms. Soxhlet extraction of the heartwood samples using polar (methanol) and non-polar (hexane) solvents and phytochemical screening tests were carried out. The total phenolic contents of the methanolic crude extracts from heartwood parts were determined by colorimetry at 760 nm using Folin-Ciocalteau’s reagent and gallic acid was used as standard. The methanolic extracts were also checked for primary antioxidant activities using an in vitro method, measured by free radical scavenging activity of 2, 2’-Diphenyl-1- Picrylhydrazyl (DPPH) radical. The absorbances were measured at 517 nm by UV/VIS spectrophotometer and compared with standards Trolox and Butylated Hydroxyanisole (BHA). The results from this study suggest that N. subdita heartwood extract may serve as a potential source of natural antioxidant for future development in food and nutraceutical applications