19672 research outputs found
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Styryl lactones from roots and barks goniothalamus lanceolatus
No full textA new styryl lactone, 5R,6R-5-hydroxy-6-styryltetrahydropyrane-2-one 2 was isolated from the roots of an endemic Goniothalamus lanceolatus Miq. of Sarawak, Malaysia. Furthermore, seven previously undescribed diastereomers, 5R,6R-5-hydroxygoniothalamin 3, 5R,6R-5-acetylgoniothalamin 4, 6S,7S,8S-goniodiol-7-monoacetate 5, 6S,7S,8S-goniodiol-8-monoacetate 6, goniofupyrone B 7, deoxygoniopypyrone B 8 and 1S,5S,7R,8S,3-endo,7-endo-(+)-8-epi-9-deoxygoniopypyrone acetate 9, along with six known styryl lactones (1, 10-15) were also isolated and characterized. 6S-goniothalamin 1 is reported for the first time from a Goniothalamus species. 1, 11 and 12 showed cytotoxic activity against human colon and lung cancer cell lines with IC 50 values ranging from 2.38-7.59 µM
Load deflection analysis of rectangular graphene diaphragm for MEMS intracranial pressure sensor applications
No full textThere is a need to establish an ultra-small micro pressure sensors in dynamic performance for intracranial monitoring which can reduce the risk of inflammation and infection and allow for its insertion through a catheter into small vessels and cavities. The need for small, lightweight and highly sensitive sensors seem to be aligned with the properties owned by graphene based sensor that have been overwhelmingly researched for their applications in biomedical engineering, sensor technology and electronic applications. The work described in this report aims to fill this gap and presents the deflection analysis and internal stress of pressurized rectangular graphene diaphragm having various b/a (length/width) ratio and thicknesses. The sensing structure of MEMS intracranial pressure sensor consists of a rectangular graphene diaphragm suspended over a cavity that is formed on silicon substrate. The deflection and sensitivity analysis was done using COMSOL Multiphysics software by applying various micron thicknesses of multilayered graphene. For the rectangular graphene diaphragm with b/a ratio of 2 and 4, results shows that the internal stress is associated with the thickness of the graphene diaphragm and the effect of thickness become less significant when thickness reaching 0.25 µm for graphene diaphragm with b/a ratio of 6. Due to the influence of this internal force, multilayer graphene diaphragms with higher thickness are more sensitive than monolayer. This study has shown the feasibility of graphene diaphragm in piezoresistive MEMS intracranial pressure sensor application
Dynamically Adjustable Moving Average (AMA’) technical analysis indicator to forecast Asian Tigers’ futures markets
No full textTo determine the predictability of futures time series, the daily stock market indices’ futures returns from the Asia Tigers countries, namely Hong Kong's Hang Seng Futures (HSF), South Korea's KOSPI Futures (KOSPIF), Singapore's SiMSCI Futures (SiMSCIF) and Taiwan's TAIEX Futures (TAIEXF) from 2006 to 2013 are examined for profitability results using technical analysis indicators. A dynamic volatility indicator, named Adjustable Moving Average (AMA’) is used as a trade timing devise to seek returns above the threshold buy and hold strategy. Using the information learnt during this in-sample period, further tests are conducted on an out-of-sample period, 2014–2015 to validate the viability of AMA’. AMA’ adjusts to the prevailing market conditions, to avoid some whipsaws (trading losses) in range trading and capture a larger portion of profit by entering into the new trends early. Using the trading signals from AMA’ and the other moving averages rules, evidence of returns after transaction costs above those of the threshold passive buy and hold strategy are found in these time series’ returns, especially more so for AMA’. The results here suggest that it is worthwhile to investigate the profitability of moving averages trading rules, especially the more adjustable ones
Education inequality in West African countries: Does investment in education matter?
No full textThe paper examines whether education investment has an impact on the high quantity of education inequality in the West African (WA) countries. The paper considers inflation as a constraint to government capability to invest in education. In consequence, the study used a balanced panel data of twelve countries where education inequality is the dependent variable, and that education index serves as a proxy for education inequality since it is a measure of disparity regarding human development. The research used panel time series data from Human Development Indicators and World Bank databases, with panel data analytical techniques. The data have 16 data points that covered 1999 to 2014 with a total sample size of 192. With the presence of missing completely at random (MCAR) of the data, expectation maximisation (EM) technique was employed to replace the missing values. Although existing official data indicated that the governments of the WA countries invested 4.58% of the gross domestic product (GDP) of public expenditure that goes to education sector, which is higher than OECD countries, this research results indicate that the cumulative public expenditure that goes to education significantly increases the volume of education inequality in the WA countries. Therefore, the study concludes that amount invested seems insufficient to reduce education inequality for the countries to catch-up with the desired skill, knowledge and growth. So, the researchers propose and suggest UNESCO to have a higher rate of education expenditure as a ratio of GDP for education financing should be strictly followed in the annual government budgeting. The researchers further suggest that the region is expected to consistently develop a five-year expenditure rolling plan (ERP) on education to increase human capital stock leading to a knowledge-based economy
Yohimbine-related Alkaloids from Tabernaemontana corymbosa
No full textFive new yohimbine-type indole alkaloids were isolated from the leaves of Tabernaemontana corymbosa. Their structures were determined on the basis of the NMR and Circular Dichroism (CD) spectroscopy
Measuring Human, Physical and Structural Capital Efficiency Performance of Insurance Companies
No full textBased on the strategy perspective of intellectual capital, this paper proposes an integrated framework that is practical to estimate the human, physical, and structural capitals (intellectual capital) efficiency performance, at firm level. This paper uses a dynamic network data envelopment analysis model to estimate the intellectual capital efficiency at three levels in the insurance industry over the period of 2005–2012. Within the insurance industry, deficiencies occurred in the human and structural capital stages as opposed to the physical capital stage. A further investigation indicates that total investment is the major concern for the deficiencies. Moreover, the cluster analysis highlights the strengths and weaknesses of the insurers based on their inherently similar efficiencies. Malaysian insurance industry need to translate and promote the existing knowledge-based economy agenda lauded by the government to improve the intellectual capital efficiency, particularly at the human capital level
Dental students as smoking cessation counsellors: Patients' and providers' perspective
No full textIntroduction: This study assesses dental students' and patients' perceptions on the role of dental students as smoking cessation counsellors as well as the patient's quit rate at the University of XX. Materials and methods: Self-administered questionnaires were distributed to all senior dental students (n=154) in XX University and telephone call interviews were conducted on their patients (n=169) who received smoking cessation counselling from September 2010 to June 2013. Results: Response rates for dental students and patients were 68.2% and 67.3% respectively. Most of the dental students in this study were females (72.3%) whereas the majority of patients were males (97.6%). An average of six months follow up indicated that 22.5% of patients had quit smoking, 65.3% reduced the number of cigarettes smoked and 6.5% had relapsed. About a third of patients surveyed (33.1%) believed that smoking cessation counselling was extremely helpful compared to what students perceived (5.7%, p<0.01). A higher percentage of patients (89.9%) rated the smoking cessation counselling performance as "excellent", as compared to students' rating (58.1%, p<0.01). The majority of the dental students and patients agreed that students should enquire about patients tobacco usage, information regarding the effects of smoking on oral health should be transmitted to patients and that quit smoking assistance should be offered. Conclusion: Smoking cessation counselling conducted by dental students seemed to be effective in assisting patients to reduce the number of cigarettes smoked and in quitting smoking. To some extent, both patients and students had positive attitudes towards smoking cessation counselling
Anti-infective activities of 11 plants species used in traditional medicine in Malaysia
No full textTreatment of drug resistant protozoa, bacteria, and viruses requires new drugs with alternative chemotypes. Such compounds could be found from Southeast Asian medicinal plants. The present study examines the cytotoxic, antileishmanial, and antiplasmodial effects of 11 ethnopharmacologically important plant species in Malaysia. Chloroform extracts were tested for their toxicity against MRC-5 cells and Leishmania donovani by MTT, and chloroquine-resistant Plasmodium falciparum K1 strain by Histidine-Rich Protein II ELISA assays. None of the extract tested was cytotoxic to MRC-5 cells. Extracts of Uvaria grandiflora, Chilocarpus costatus, Tabernaemontana peduncularis, and Leuconotis eugenifolius had good activities against L. donovani with IC50 < 50 μg/mL. Extracts of U. grandiflora, C. costatus, T. peduncularis, L. eugenifolius, A. subulatum, and C. aeruginosa had good activities against P. falciparum K1 with IC50 < 10 μg/mL. Pinoresinol isolated from C. costatus was inactive against L. donovani and P. falciparum. C. costatus extract and pinoresinol increased the sensitivity of Staphylococcus epidermidis to cefotaxime. Pinoresinol demonstrated moderate activity against influenza virus (IC50 = 30.4 ± 11 μg/mL) and was active against Coxsackie virus B3 (IC50 = 7.1 ± 3.0 μg/mL). β-Amyrin from L. eugenifolius inhibited L. donovani with IC50 value of 15.4 ± 0.01 μM. Furanodienone from C. aeruginosa inhibited L. donovani and P. falciparum K1 with IC50 value of 39.5 ± 0.2 and 17.0 ± 0.05 μM, respectively. Furanodienone also inhibited the replication of influenza and Coxsackie virus B3 with IC50 value of 4.0 ± 0.5 and 7.2 ± 1.4 μg/mL (Ribavirin: IC50: 15.6 ± 2.0 μg/mL), respectively. Our study provides evidence that medicinal plants in Malaysia have potentials as a source of chemotypes for the development of anti-infective leads
Double gene targeting multiplex PCR-RFLP detects Crocodylus porosus in chicken meatball and traditional medicine
No full textCrocodiles have been hunted and consumed for centuries for skins, nutrients, and medicines. These indomitable trends have overpowered restrictions from wildlife and conservation agencies, continuing the illegal trades of crocodiles across the world. This paper described the development of a very stable, fast, and secured polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay for the confirmed detection of Crocodylus porosus under any matrices and decomposing treatments. Two very short-sites (77 and 127-bp) of atp6 and cytb genes of C. porosus were controlled digested with AciI enzyme; producing distinctive RFLP patterns (83, 54, 44 & 23 bp). The enzyme digested assay was stable following extreme boiling, autoclaving, and microwaving treatments that break down DNA. The sensitivity was tested and validated in model meatballs and it was suitable for detecting 0.01% crocodile meatball matrices. The optimized RFLP assay was used to screen 3 commercial meatballs and 21 traditional medicines (TM). While no crocodile DNA was found in commercial chicken meatballs, 4/21 TM products were found correctly labelled to contain C. porosus DNA. The novel assay demonstrated sufficient merit to be used by regulatory agencies for any forensic and/or archaeological identification of C. porosus even under the state of decomposition
Oral Cryotherapy: Prevention of Oral Mucositis and Pain Among Patients With Colorectal Cancer Undergoing Chemotherapy
No full textBACKGROUND: Evidence remains mixed on the benefits of oral cryotherapy in the prevention of oral mucositis and pain associated with fluorouracil-based chemotherapy. OBJECTIVES: The intent of this article is to evaluate the effect of oral cryotherapy on the prevention of oral mucositis and pain among patients with colorectal cancer undergoing fluorouracil-based chemotherapy. METHODS: Using an experimental study design, the authors randomly assigned 80 patients to either the intervention (n = 40) or usual care group (n = 40). Intervention group participants received oral cryotherapy in the form of ice chips held in their mouths during chemotherapy infusion. Both groups used sodium bicarbonate mouthwash postchemotherapy until the next cycle. FINDINGS: In the usual care group, most participants reported grade 2 (moderate to life-threatening) or greater mucositis. Pain associated with mucositis was lower using oral cryotherapy, with the majority of participants in the intervention group reporting no pain