Anti-proliferative effects of pandan leaves (Pandanus amarylfolius), kantan flower(Etlingera elatior) and turmeric leaves (Curcuma longa).

Purpose – The purpose of this paper is to screen cytotoxic activities of commonly used culinary plants in Malaysia, Pandanus amaryllifolius (daun pandan), Curcuma longa (turmeric leaves) and Etlingera elatior (kantan flower) against selected cancer cell lines. Design/methodology/approach – Plant samples were extracted exhaustively with ethanol and concentrated under rotary evaporator. Cytotoxic evaluation was carried out with plant extracts(0-100mg/ml) using 72-h MTT assay. Findings – Exposure of plant extracts reduced cell viability of HepG2 (hepatocellular carcinoma),HT-29 (colon carcinoma), MDA-MB-231 (non-hormone-dependent breast cancer), MCF-7(hormone-dependent breast cancer) and HeLa (cervical cancer); 50 percent inhibitory values (IC50) were obtained for MDA-MB-231, HepG2, HT-29. Extracts within the concentrations of 10-100mg/ml were found not to be effective against proliferation of MCF-7 and HeLa

Antibody prevalence and factors associated with exposure to Orientia tsutsugamushi in different aboriginal subgroups in West Malaysia

Background: Limited data is available on the current status of scrub typhus infection in the aboriginal population in Malaysia. This study was aimed to provide recent data on the degree of exposure of 280 individuals from seven aboriginal subgroups to Orientia tsutsugamushi (causative agent of scrub typhus) in West Malaysia. The environment, socioeconomic and behavioural risk factors associated with the disease were also investigated. Methods/Findings: The antibody prevalence to O. tsutsugamushi ranged from 0 to 36.4% in seven subgroups, with high prevalence rates noted in subgroups involved in agricultural activity and the lowest prevalence rates noted in subgroups whose main occupations were associated to fishing. Univariate analysis indicated populations with age above 18 years (OR = 1.15, 95% CI = 1.02–1.30, P = 0.015), working (OR = 1.99, 95% CI = 1.01–3.92, P = 0.044), working at agriculture area (OR = 1.18, 95% CI = 0.98–1.42, P = 0.031), receiving household income less than US$166.7 (RM500) per month (OR = 2.43, 95$ 166.7 (RM500) per month and having close contact with animal pets are 3.6 times (95% CI = 1.81–7.03, P,0.001), 1.3 times (95% CI = 1.14–1.64, P = 0.002) and 1.2 times (95% CI = 1.05–1.06, P = 0.006) more likely to have exposure to O. tsutsugamushi, respectively. Conclusion: The present study indicates that scrub typhus is still an important disease in the aboriginal population in Malaysia. Awareness about the disease and education on the preventive measures are important in reducing the risk of acquiring scrub typhus in the population studied

Seroprevalence of dengue amongst inhabitants of the semi-forested and forest fringe areas of peninsular Malaysia

Dengue is an endemic disease in the urban areas of the tropics and subtropics regions of the world. Its significance in the semi-forested and forest fringe areas, however, has not been well described. The present study investigated the seroprevalence of dengue amongst the indigenous or Orang Asli communities of peninsular Malaysia and correlated it with the population, socio-economic and geographical attributes of the communities’ surroundings

Roles of MAPK and Spindle Assembly Checkpoint in Spontaneous Activation and MIII Arrest of Rat Oocytes

Rat oocytes are well known to undergo spontaneous activation (SA) after leaving the oviduct, but the SA is abortive with oocytes being arrested in metaphase III (MIII) instead of forming pronuclei. This study was designed to investigate the mechanism causing SA and MIII arrest. Whereas few oocytes collected from SD rats at 13 h after hCG injection that showed 100% of mitogen-activated protein kinase (MAPK) activities activated spontaneously, all oocytes recovered 19 h post hCG with MAPK decreased to below 75% underwent SA during in vitro culture. During SA, MAPK first declined to below 45% and then increased again to 80%; the maturation-promoting factor (MPF) activity fluctuated similarly but always began to change ahead of the MAPK activity. In SA oocytes with 75% of MAPK activities, microtubules were disturbed with irregularly pulled chromosomes dispersed over the spindle and the spindle assembly checkpoint (SAC) was activated. When MAPK decreased to 45%, the spindle disintegrated and chromosomes surrounded by microtubules were scattered in the ooplasm. SA oocytes entered MIII and formed several spindle-like structures by 6 h of culture when the MAPK activity re-increased to above 80%. While SA oocytes showed one Ca2+ rise, Sr2+-activated oocytes showed several. Together, the results suggested that SA stimuli triggered SA in rat oocytes by inducing a premature MAPK inactivation, which led to disturbance of spindle microtubules. The microtubule disturbance impaired pulling of chromosomes to the spindle poles, caused spindle disintegration and activated SAC. The increased SAC activity reactivated MPF and thus MAPK, leading to MIII arrest

Abstract

Many classification problems in real-world applications involve class labels derived from an underlying continuous variable typically with certain notion of utility attached, e.g., future profit contribution by individual customers determining the customer class, future price of a stock determining the buy/sell class, quantity of back orders determining the restocking decision, etc. When learning a classifier in such a context, for each data instance the underlying continuous variable, referred to as the utility index, is also available in addition to the class label. We refer to this problem as the utility-based classification problem, which essentially deals with classification using the regression data. This paper introduces this problem and discusses drawbacks of both classification and regression approaches to this problem. We propose the transformed regression approach, which involves an s-curve transformation function, to unify both the classification and regression approaches and to exploit the special structure of this problem for improved performance. Classification accuracy improvements achieved by the proposed approach were demonstrated across several classification/regression algorithms with simulation data and a real-world dataset. Keywords: Utility-based data mining, Regression, Classification, Transformation. 1

Diffusion trapped oxygen in oxide derived Copper electrocatalyst in CO2 reduction

Oxide-derived Cu (OD-Cu) catalysts have shown an excellent ability to ensure C-C coupling in the electrochemical carbon dioxide reduction reaction (eCO2RR). However, these materials extensively rearrange under reaction conditions, thus the nature of the active site remains controversial. Here, we studied the reduction process of OD-Cu via large-scale molecular dynamics at first-principles accuracy introducing experimental conditions. The oxygen concentration in the most stable OD-Cu materials increases with the increase of the pH/potential/specific surface area. In long electrochemical experiments, the catalyst would be fully reduced to Cu, but it takes a considerable amount of time to remove all the trapped oxygen, and the highly reconstructed Cu surface provides various sites to adsorb oxygen under relatively stronger reduction potentials (U = –0.58 VSHE at pH=14, 0.25 VRHE). This work provides insight into the evolution of OD-Cu catalysts and residual oxygen during the reaction conditions and a deep understanding of the nature of active sites

Spiral Coil Inserts for Heat Transfer Enhancement in a Parallel-plate Channel

The flow fields and heat transfer characteristics in a parallel-plate channel with a transversely placed spiral coil insert were investigated by three-dimensional numerical simulation. The structure of multi-longitudinal-vortices (MLVs) induced by the spiral coil and the effects of MLVs on velocity and temperature fields were studied. The three-dimensional spiral coil induces a series of longitudinal vortices in the channel including leading longitudinal vortex, mainstream longitudinal vortices, near-wall longitudinal vortices, and rear central longitudinal vortex. Transport by the longitudinal vortices can increase the mass exchange between the boundary layer and the mainstream, which speeds up the heat migration from the channel walls and enhances the heat diffusion in the mainstream