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Silver nanoparticles decorated polyaniline nanocomposite based electrochemical sensor for the determination of anticancer drug 5-fluorouracil
No full textA highly efficient electrochemical sensor for the analysis of anticancer drug 5-fluorouracil (5-FU), is fabricated based on silver nanoparticles-polyaniline nanotube (AgNPs@PANINTs). AgNPs@PANINTs nanocomposite has been synthesized by a simple one-step method. Synthesized AgNPs@PANINTs nanocomposite was studied by Fourier transform infrared spectrometry, Scanning Electron Microscopy and Energy Dispersive X-ray. The fabricated PANINTs@AgNPs PGE was applied to the electrochemical sensing of 5-FU. Cyclic voltammetry and differential pulse voltammetry experiments illustrated high electro activity for the AgNPs@PANINTs nanocomposite. The study was explored using the Taguchi experimental design method. Electrochemical measurements using differential pulse voltammetry showed a wide linear relationship between 5-FU concentration and peak height within the range 1.0–300.0 μM with a low detection limit (0.06 μM). Also, the fabricated sensor showed excellent selectivity in the presence of two anticancer drugs and a number of other interfering compounds. The as-prepared sensor showed to be a promising device for a simple, rapid, and direct analysis of 5-FU
Adventitious Root Cultures of Boesenbergia rotunda as a Source of Pinostrobin
No full textPinostrobin is the major bioactive compound from the roots of Boesenbergia rotunda, and it possesses activities against HIV, Helicobacter pylori, ulcer, leukemia and inflammatory. The present study aimed to optimize the conditions for the production of adventitious roots from B. rotunda on Murashige and Skoog (MS) solid medium. The effects of the MS strength and sucrose concentration on adventitious root growth were studied as well as the production of pinostrobin. Adventitious roots were initiated from bud explant of B. rotunda, on MS solid medium supplemented with 2.0 mg/L 1-Naphthaleneacetic acid (NAA) and were used to establish root suspension cultures. The optimum biomasses of 1.83 ± 0.21 g fresh weight were obtained with a 1/2 strength of MS medium. High pinostrobin production (3.54 mg/g) was obtained with 50 g/L of sucrose concentration. These results suggest that adventitious root cultures are suitable for the raw material for the large-scale production, which contain a high yield of the pinostrobin compound. The results also revealed that the culture condition is a good strategy for enhancing the pinostrobin content in the adventitious root cultures
The tunable permittivity of multi-walled carbon nanotubes/silver nanoparticles reinforced polyvinyl alcohol (PVA) nanocomposites at low frequency
No full textThis paper is about tailoring high permittivity of multi-walled carbon nanotubes/silver nanoparticles (MWNT-AgNP) filled polyvinyl alcohol (PVA) nanocomposites at low frequency. PVA/MWNT-AgNP nanocomposites were synthesized via solution-casting technique at low MWNT content with different loading of AgNP. The nanocomposites showed a significant increment in ac conductivity, σ ac, and dielectric permittivity, ϵ′ by two orders of magnitude as compared to pure PVA. The maximum ϵ′ value was achieved about 600 at 1.0 wt% of AgNP due to the increased charge carriers density and high interfacial polarization within the nanocomposites. The relaxation frequency was shifted towards a higher value with the increased of AgNP content while the relaxation time was decreased by 40%. Field emission scanning electron microscopy (FESEM) images showed the enhanced distribution of MWNT in the presence of AgNP to provide conductive pathways in the matrix. This was confirmed by energy-dispersive x-ray (EDX) analysis and ultraviolet-visible (UV-vis) spectroscopy. As a result, PVA/MWNT-AgNP nanocomposites have great potential for electrical applications such as cable accessories, high charge-storage capacitor and electromagnetic interference shielding materials
Law and the judiciary: Divides and dissent in Malaysia
No full textMalaysia is a common law country, and as such the decisions of its courts have a binding and law-making force. This means that the Malaysian judiciary is highly influential in setting the tenor of governance. In this article I examine and analyze some key decisions that had an influence on divisiveness and dissent in the country. I point out that the courts have been poor in ensuring that the legal system protects the nation from divisive elements, and the legal system does not do enough to guarantee the fundamental rights and democratic principles that were envisioned by the founding fathers for the citizenry. The article closes with an attempt to understand why this is the case
Relationships between cornell musculoskeletal discomfort questionnaire and online rapid office strain assessment questionnaire
No full textBackground: The Rapid Office Strain Assessment (ROSA) is a tool employed online to screen office workstations, which may require modification to decrease musculoskeletal discomfort of workers. This study aimed to examine if the ROSA is able to evaluate pain severity in the lower back, shoulder and neck of office workers accurately. Methods: Overall, 142 participants (height: 1.80 ± 0.15 m, BMI: 26.08± 6.70, age: 35±15 yr) with at least a year of working experience completed both questionnaires, the online ROSA and the Cornell musculoskeletal discomfort, in 2016 in Malaysia. Results: Relationship between the total scores of both questionnaires for lower back, shoulder and neck pain were significant but exhibited a weak to moderate relationship (range of r values from 0.012 (CI 95%,-0.153-0.176) to 0.503 (CI 95%, 0.369-0.616). Conclusion: The online ROSA does not appear to be a reasonable tool for evaluating the severity of lower back, shoulder and neck pain among office workers as the correlations were low. We suggest continued use of the musculoskeletal discomfort questionnaire. Additional studies are required to further examine the ROSA for other anatomical regions
Curing of epoxy/alkyd blends in self-healing coating
No full textSelf-healing of polymeric material using microcapsules has been developed to repair microcracks within the materials. The self-healing character is reflected from the curing behavior of the material. In this work, curing study of alkyd/epoxy blend was carried out by replacing part of amine hardener with alkyd in the epoxy formulation. The inclusion of alkyd in the epoxy blend resulted in higher degree of curing and higher thermal stability compared to the alkyd-free blend, as evidenced from higher heat of reaction values of differential scanning calorimetry and maximum degradation temperature at 379°C, respectively. Self-healing reaction of epoxy coating as evaluated by Fourier-transform spectroscopy revealed that the 914 cm−1 peak attributed to C–O–C of epoxy has decreased, as the epoxide group was consumed in the reaction. Appearance of a new peak at 1631–1632 cm−1 in the cured coating confirmed that the epoxide has reacted with the carboxylic acid group of alkyd to form ester
First-principle calculations of structural, electronic and magnetic investigations of Mn2RuGe1-xSnx quaternary Heusler alloys
No full textFirst-principles calculations were used to calculate the structural, electronic and half-metallic ferromagnetism of Mn2RuGe1-xSnx (x = 0, 0.25, 0.50, 0.75, 1) Heusler alloys. The Hg2CuTi-type structure is found to be energetic more than Cu2MnAl-type structure for both Mn2RuGe and Mn2RuSn compounds. The calculated lattice constants for Mn2RuGe and Mn2RuSn are 5.91 Å and 6.17 Å, respectively. The electronic band structures and density of states of Mn2RuGe show a half metallic character with total magnetic moments, 2 μB per formula unit that are in good agreement with Slater-Pauling rule with indirect band gap, 0.31 eV along the direction Γ –X. It is observed that the total magnetic moment per cell increases as Sn concentration increases in the Heusler alloys
Evaluation of Psychometric Properties of the Second Version of the Taqwa (Piety) Questionnaire in Bahasa Melayu
No full textThe aim of the study is to evaluate the psychometric properties of the Bahasa Melayu version of the Taqwa (piety) questionnaire, used for the measurement of behaviour of Drug Dependency Syndrome (DDS), in Malay patients. A sample of 98 males with a psychiatric diagnosis (DSM-IV-R) as the DDS was randomly selected from Kajang Khafidz Polyclinic Kuala Lumpur, Malaysia. After receiving their agreement to attend the study, they completed the Taqwa (piety) questionnaire. The reliability was assessed by determining the Cronbach’s α to measure the consistency of related questions for all four dimensions (subscales), including individual, social, cognitional, and emotional Taqwa behaviour. In the next step to evaluate the composite reliability, convergent, and discrimination validity, a measurement model was determined via Conformity Factor Analysis (CFA) based on Partial List Square method (Smart- PLS Ver: 2M3). The reliability of four dimensions of the questionnaire was acceptable (α1=0.881,α2-0.862,α3=0.86,andα4=0.90)and correlated to each other. However, according to the CFA method, the items with low loading factor (<0.5) were excluded from each dimension. Item 24 and 35 that were related to individual Taqwa, and item 35 that belonged to emotional Taqwa were excluded from the analysis. The composite reliability and convergent, and discrimination validity were satisfied in all conformity factor loading that exceeded 0/05. The psychometric properties of the Taqwa questionnaire are acceptable, and the scale is a good instrument for assessing the Islamic attitude, beliefs, and behaviour of the Bahasa Melayu DDS patients
Is coronary arteritis a feature in secondary haemophagocytic lymphohistiocytosis?
No full textHaemophagocytic lymphohistiocytosis (HLH) is rare. Although Kawasaki disease (KD) has been reported as a precursor to HLH, coronary arteritis occurring at the onset of secondary HLH, not in association with KD, has not been reported. An 8-year-old girl presented with virus-induced secondary HLH associated with a giant aneurysm and ectasia of the coronary arteries which was detected incidentally at onset of the disease. She did not fulfill the criteria for diagnosis of KD. The coronary lesions improved after 6 months of treatment with dexamethasone and etoposide. Echocardiography early in the course of HLH is a useful tool to detect the unusual finding of coronary arteritis which may carry significant clinical sequelae
Highly-ordered TiO 2 nanotubes decorated with Ag 2 O nanoparticles for improved biofunctionality of Ti6Al4V
No full textThe nanotubular arrays of titanium dioxide (TiO2 NTs) have recently received considerable interest for fabrication of dental and orthopedic implants. However, their antibacterial activity requires substantial improvement for the potential infections minimization, without compromise of their biocompatibility. In this work, TiO2 NTs were developed on Ti6Al4V substrates via anodization at a constant potential of 60 V for 60 min, followed by heat treatment at 500 °C for 90 min. Physical vapor deposition (PVD) was further employed to decorate silver oxide nanoparticles (Ag2O NPs) on the nanotubular edges. The results indicated that the highly-ordered TiO2 NTs with decorated Ag2O NPs could promote the apatite formation and kill 100% of the Escherichia coli (E. coli) bacteria within 2 h. Moreover, proliferation of the human osteoblast cells (HOb) was continuously stimulated throughout culture on the Ag2O NPs-decorated TiO2 NTs. The variation in the viability of HOb cells was statistically insignificant at differed cultivation intervals, indicating the negligible effect of the decorated Ag2O NPs on the osseointegration of these implant materials