Dye-sensitized solar cell (DSSC) is the third generation of thin film solar cell. In this work, carrot fruit dye was prepared and used in DSSC as a sensitizer. TiO2–ZrO2 fine binary oxide was mechanochemically prepared and made paste. TiO2–ZrO2 paste (colloidal) was deposited onto FTO/glass in two ways, i.e. as single and double coatings by rolling method. It was immersed in the carrot solution to get dyed cell. The dyed TiO2-ZrO2-FTO/glass cell was offset with the FTO/glass cell coated with adhesive carbon paste. Photovoltaic properties of prepared TiO2–ZrO2 DSSC cell were measured. Results showed that the efficiency of double coating cell was greater than that of the single coating cell. According to the fill factor from the experiments, both the DSSC cells were acceptable for industrial requirement. Hence, it can be concluded that the results obtained were acceptable in the use of cost-effective and eco-favourable dye-sensitized solar cell.
In this paper, a mathematical model is developed based on mass and momentum balance for carbon dioxide absorption into aqueous ammonia solution. The model is simplified based on the assumption that the CO2 absorption into aqueous ammonia is a pseudo-first-order reaction. Laplace transform method is applied in order to solve the partial differential model equation. Finally, the CO2 molar flux is expressed as a function of partial pressure of CO2, concentration of aqueous ammonia, temperature and gas-liquid contact area. Variation of CO2 molar flux with partial pressure of CO2 and temperature is discussed and a comparison is performed with experimental data from literature. Variation of CO2 molar flux is also shown with gas-liquid contact area. The calculated flux from the model follows the same trend as that of the experimental data reported in literature and the accuracy is within the accepted limit. The mathematical model is very helpful to predict the CO2 molar flux as a function of partial pressure of CO2, concentration of aqueous ammonia, temperature and gas-liquid contact area.
Formalin is a clear solution of 37% formaldehyde in water. It is used in dentistry as a disinfectant, antiseptic and mainly as tissue fixative for preserving biologic specimens for histopathologic examination. The human knowledge on systemic formaldehyde intoxication is inadequate as only few cases of formalin ingestion have been reported. This paper presents a brief communication of the adverse effect of formalin to the human tissue.
Composite resins Amaris is claimed to have hydrophobic effect which minimizes the staining intake. This study is to investigate the colour stability of Amaris compared to Filtek Z250 in coffee solution. Sixty discs of composite resins Filtek Z250 (3M ESPE) and Amaris (Voco) with diameter of 5mm and depth of 2mm were fabricated by packing in a drinking straw and sectioned with hard tissue cutter (Exakt, Japan). The surfaces of the specimens were polished with Sof-Lex disc before each group of the samples is immersed in coffee solution. They were kept in the solution for 4 days at 370C and assessed at the period of 2 hours, 1 day, 2 days, 3 days, and 4 days. The staining was assessed visually and recorded using Lobene (1968) Stain Index and score was given accordingly. The colour changes of both groups were not statistically significant (p
The removal of heavy metals like lead, copper and cadmium from wastewater streams is an important environmental issue. The capability of immobilized Pycnoporus sanguineus (P. sanguineus), a white-rot macrofungi to remove heavy metals from aqueous solution in a packed bed column was investigated. Lead (Pb (II)) biosorption by immobilized cells of P. sanguineus was investigated in a packed bed column. The experiments were carried out by considering the effect of bed height (5-13 cm), flow rate (4-12 ml min-1) and initial lead (II) concentration (50-300 mg L-1). The breakthrough profiles showed that the saturation of metal ions was achieved faster for 5 cm bed height and 12 ml min-1 influent flow rate. However, the breakthrough time decreased as the initial metal concentration increased from 50 to 300 mg L-1. The column was regenerated using 0.1M HCl solution and biosorptiondesorption studies were carried out for 2 cycles. The results showed that the breakthrough time decreased as the number of cycle was proceeded.
Konjac glucomannan (KGM) was treated with or without sonication and/or hydrochloric acid (HCl).
Hydrolysis effects on KGM were studied for properties such as degree of hydrolysis, fluidity, molecular mass, and creep properties. The degree of hydrolysis for sonicated KGM and acid treated KGM were not significantly different. However, the combination treatment of acid hydrolysis and sonication was found effective in yielding a smaller molecular weight fraction of KGM and solution with higher fluidity. From the creep analysis, KGM treated with combination treatment exhibited the highest compliance among samples tested. In general, ultrasound mediated acid hydrolysis was found to be a promising technique in degrading high molecular weight biopolymer. This could be attributed to a localized high temperature and high shear forces generated during cavitation that facilitated the endothermic acid hydrolysis.
Side effects such as abrasion of the dental hard tissue have been frequently observed following the extensive use of mechanical cleansing. As promising antiseptics like chlorhexidine produces extrinsic dental staining on long term usage, there has been increasing interest and research generated towards chemically based stain removing agents. This invitro studyexamined whether some commercial oral hygiene products could inhibit chlorhexidine derived stain independent of any mechanical cleansing action. Perspex blocks were soaked in triplicate in chlorhexidine solution for 2 minutesand stain inhibition by these products was determined by further soaking the blocks in productl water slurries for 2 minutes and finally in tea solution for I hourly periods. The optical density (OD) of each specimen was determined at each hourly interval by spectrophotometry at 395 nm and the mean values obtained. At the end of the study, most of the products inhibited stain compared to water control and there was a variation in the stain inhibitingefficacyof the products. It is thus concluded that oral hygiene products like dentifricesand mouthrinses can inhibit chlorhexidine derived extrinsic dental stain to a variable degree through a chemical action by contained ingredients.
Introduction: The aim of treatment for hyperemesis gravidarum is to stop vomiting, correction of dehydration, starvation and electrolytes imbalance. The common types of fluid used for fluid replacement are isotonic solutions like normal saline and hartman's solutions. The absence of potassium in normal saline makes hartman's solution superior but there is a possibility that the lactate component in hartman's solution could worsen the starvation state of the patients. This study is to evaluate which of these two solutions is more effective for fluid replacement in hyperemesis gravidarum. The objectives are to compare which solution corrects dehydration, hypokalaemia and acetonuria faster and to evaluate whether the ketosis state is aggravated by lactate component in hartman's solution. Materials and Methods: Patients with hyperemesis gravidarum were randomised to receive either Hartman's solution or normal saline at the rate of 125mls/hour. Blood urea and serum electrolytes, haematocrit, lactate and urine acetone were taken during admission and repeated every 12 hours. The volume of fluid required to correct dehydration, hypokalaemia and acetonuria were compared. Comparison of the pre and post treatment level of serum lactate were also done. Results: Both hartman's solution and normal saline are both effective in correcting dehydration (11.52±3.28 pints versus 11.94 ± 2.30pints respectively) and acetonuria (11.64 ± 2.75 pints versus 11.64 ± 2.54 pints respectively).
A lower volume of hartman's solution was needed to correct hypokalaemia (8.34 ± 2.44 pints versus 8.88 ± 2.63 pints) but was not statistically significant. Ketonaemia was not made worse after treatment with hartman's solution. Conclusion: Normal saline and hartman's solution are equally effective in treating complications of hyperemesis gravidarum.
The impact of good assessment in medical education depends on how appropriately the tools measure the clinical performance and how reliable, valid and feasible they are to achieve the logical decision. The traditional methods of clinical examination using long and short cases and orals are often argued for its subjectivity, low reliability and inadequate context specificity. Oral test though comparatively more valid due to its face-to-face questions are considered less reliable for problems of unstandardized questions, inconsistent marking and lack of sufficient testing time. Development of an “objective structured clinical examination” (OSCE) was sought as a solution to these problems. But the fragmented representation of the context in a number of stations in OSCE makes it less authentic for an integrated judgment of performance. Yet another method to thought of, was the workplace-based assessment (WPBA) but it takes a snapshot as a predefined attribute of a more complex integrated assessment such as long case. However due to the problem of feasibility it is less likely that high stakes examination as summative assessment will ever be able to attain workplace-based assessment such as Mini-CEX and DOPS. A TOACS (task oriented assessment of clinical skills) format currently used in high stakes fellowship examination in one of the center and claimed to have more active role for examiners was analyzed and compared with OSCE. Author however, did not find a difference except the difference of acronyms of the two formats. Both have multiple, fragmented static or interactive stations of 5-10 minutes duration with or without examiners, patients or exhibits and a marking scheme comprising of checklist or global rating. In the backdrop of this context a new assessment format named the ‘task integrated objective structured clinical examination” or TIOSCE modified from OSCE is currently developed in School of Medical Sciences (SMS) at USM. However, it is a different version of OSCE in which though the principle concept is the same as that of an OSCE, the continuum of clinical skill’s work up of the same patient’s is followed through to test multiple short attributes of clinical competences. As it retains most of the favorable features, TIOSCE also addresses some of the odds features of OSCE.
The effect of ribose-induced Maillard reaction on the physical and mechanical properties of gelatin films was investigated. Bovine gelatin solution (5 g/100 mL) containing glycerol and sorbitol (1:1) was mixed with 20% (R20), 40% ribose (R40), or 40% sucrose (S40) (weight % is based on gelatin dry weight) followed by heating (90ºC, 2 h) and oven drying to produce dried gelatin films. R20 and R40 films were brownish in color with lower light transparency, while CF (control film; without sugars) and S40 were colorless and had higher transparency. Tensile strength and Young Modulus values of the films were in the order; CF > R20 > R40 > S40, while elongation at break was in the order; R40 > S40 > R20 > CF. Water solubility and swelling percentages of the films were in the order; CF > S40 > R20 > R40, indicating the occurrence of insoluble “Maillard complexes” within R20 and R40 films. R20 and R40 films showed maximum light absorption at wavelength of 200 − 350 nm, whilst S40 and CF showed maximum absorbance at 200 − 250 nm. The addition of ribose yielded gelatin films with increased protection against UV light, even though the presence of sugars might had disrupted the inter connection of junction zones and decrease in mechanical properties. Occurrence of the Maillard reaction within R20 and R40 films could be the main reason for differences in physical and mechanical properties of films containing ribose that were formed from heated film-forming solutions.
Xiang Sha Yang Wei Wan (XSYWW) is a Chinese traditional medicine that is used for gastrointestinal disorders, specifically gastric ulcer in many countries of South-East Asia. The aim of the study was to evaluate the potential effects of XSYWW on ethanol-induced gastric ulcer in rats by means of histological Study. On a similar basis of treatment, ranitidine, a conventional medication was used as gold standard. Methods: Fifty five male Sprague-Dawley rats (250-300 gm) were divided into four groups. Group I (ethanol treated group) was the control group and gastric ulcers were induced by administering 100% ethanol (1 ml/200 g). Group II (Pre-treatment group) was divided into two subgroups; they were orally fed with 1.0 gm/kg and 2.0 gm/kg respectively of XSYWW solution. Thirty minutes later they were administered with absolute ethanol as in group I. Group III, was given an oral dose of 2gm/kg of XSYWW solution after one hour of ethanol administration. Group IV was given an oral dose of 200mg/kg ranitidine solution after one hour of ethanol administration. Five rats from groups I, III and IV were sacrificed on day 1, 2 and 3 while the animals of group II were sacrificed one hour after ethanol administration. Results: Histological study of the stomachs from ethanol treated rats showed multiple ulcers of various depths that reached the muscularis and the serosa. Conclusion: Pre or post-treated rats with XSYWW showed that XSYWW has protective effect against ethanol-induced gastric mucosal lesion. However, there was a faster and more complete healing process in the ranitidine treated group when compared to the XSYWW treated subjects.
α-Mangostin was extracted from the pericarp of the Malaysian local Garcinia mangostana linn., The structure was characterised by Infrared red, UV-Visible and Nuclear Magnetic Resonance spectroscopic data. The fluorescence peak at 500nm in ethanol was not observed in PNIPAM microgel solution. The increase of colloidal size of the gel in the presence of α-mangostin was studied by Dynamic Light Scattering and Transmission Electron Microscope. The size of the particle also increases with increasing temperature up to 45⁰C after which it began to shrink. The TEM micrograph at 45°C showed a uniformly structured pattern of the gel occurs in the range of the lowest solution critical temperature.
Carbon-11 labeled radiotracers, such as 11C-acetate and
11C-palmitate are widely used in positron
emission tomography (PET) for noninvasive evaluation of myocardial metabolism under varied
physiological conditions.These tracers are attractive probes of tissue physiology, because they are
simply radiolabled versions of the native biochemical substrates. One of the major metabolites
generated by these tracers upon the administration is 11CO2 produced via the citric acid cycle. In
quantitative modeling of
11C-acetate and
11C-palmitate PET data, the fraction of blood
11C
radioactivity present as
11CO2 needs to be measured to obtain a correct radiotracer arterial
input function. Accordingly, the literature describes a method whereby the total blood
11C-activity
is counted in blood samples treated with base solution, while the fraction of
1 1CO2 is measured
after the blood is treated with acid followed by a 10 minutes gas-purge. However, a detailed
description of the experimental validation of this method was not provided. The goal of this study
was to test the reliability of a 10 minute gas purging method used to assay
11CO2 radioactivity in
blood
The accumulation of tear film proteins as well as microbes colonization onto worn contact lenses can be eliminated conventionally by mechanical rubbing during the cleaning process. Lens2® functions in rotation manner to loosen the deposits on the contact lens and has antimicrobial coating to keep lenses away from contamination. The objective of this study was to determine the efficiency of Lens2® to remove deposited protein and reduce microbial contamination compared to conventional method. Twenty-eight subjects each wore a pair of contact lens FDA Group 1 (Polymacon, SoftLens® 38, Bausch & Lomb) for one month and cleaned them using multipurpose solution (COMPLETE® MoisturePLUSTM, Advanced Medical Optics) separately using two different methods. The right lens was cleaned conventionally while the left lens were cleaned using the Lens2®. The control group of thirteen subjects each wore a pair of contact lens for the same period and cleaned both conventionally. These lenses and its cases were then analyzed for protein deposition using Bichinchoninic Acid Assay (BCA) Kit (Sigma, USA) in 96-well plate. Microbial contamination was determined by culturing the samples on nutrient agar for bacteria and fungi and non-nutrient agar for amoeba isolation. The mean of total protein on control lenses (17.014 ± 13.246 µg/mL) was not significantly different from those on the Lens2® (21.623 ± 19.127 µg/mL). There were also low growth numbers of amoeba in each group of samples. Interestingly, there were no growths of amoeba from all Lens2® samples collected. There was also low growth numbers of bacteria in each sample group whereby Lens2® had the lowest growth of bacteria. No growth of fungi was obtained from all samples. The automatic lens cleaner, Lens2® was found to be as efficient as the conventional cleaning method. However, the Lens2® has additional advantage because of its antimicrobial material and need shorter time in the cleaning process as well as easy and effective.
The in vitro cytotoxic potential of locally produced dental porcelain was evaluated in this study. The cellular response of human osteoblast and fibroblast cell lines were assessed using MTT assay by incubating with the fluid extract of dental porcelain powder and dental porcelain discs (direct test). Aging process was carried out by submerging the discs into 3% bovine serum albumin (BSA) solution. Tests on extracts showed that dental porcelain was significantly different from the control at a concentration of 250 mg/ml. Direct test showed that dental porcelain after aging was not significantly different from the control with a mean (SD) of 89.2 (13.4)%, whereas, it was significantly different from the control before conditioning of BSA with a mean (SD) of 88.5 (12.1)%. However, the dental porcelain caused mild suppression of succinate dehydrogenase activity (
In this present study, a series of polymer electrolyte thin films were synthesized by incorporating different ratios of lithium triflate (LiCF3SO3) in a low molecular weight polyvinyl chloride (PVC) matrix by the solution casting technique. The incorporation of LiCF3SO3 suppressed the high degree of crystallinity in PVC enabling the system to possess an appreciable ionic conductivity. The ionic conductivity of the samples, with different LiCF3SO3 content, was determined by the aid of ac impedance spectroscopy. The highest ionic conductivity of 4.04 10–9 S cm–1 was identified for the composition of PVC: LiCF3SO3 (75:25). Further understanding of the ionic conductivity mechanism was based on temperature-dependent conductivity data which obeyed Arrhenius theory, indicating that the ionic conductivity enhancement was thermally assisted. The possible dipole-dipole interaction between the chemical constituents was confirmed with changes in cage peak, analysed using Fourier transform infrared spectroscopy.
Layered double hydroxide (LDH) with Mg/Al molar ratio of 4/1 (MAN-4) was synthesized by co-precipitation and followed by hydrothermal method. The compound was allowed to undergo ion exchange with K2HPO4 for 48 hours to produce MgAlHPO4 (MAHP-4). The solid produced was characterized using X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR). Adsorption of copper solution by MAHP-4 was carried out using batch experiment by mixing the copper solution and the sorbent MAHP-4. The effects of
various parameters such as contact time, pH, adsorbent dosage and initial concentration were investigated. The optimum pH for copper removal was found to be 4 and the optimum time of copper removal was found at 4 hours. The isotherm data was analysed using model isotherm Langmuir with the correlation coefficient of 0.999 was recorded. The maximum adsorption capacity, Qo (mg/g) of 142.8 mg/g was also recorded from the Langmuir isotherm. The remaining copper solution was determined by using EDXRF (Energy Dispersive XRay Fluorescence spectrometry) model MiniPal 4 (PAN analytical). The results in this study indicate that MAHP-4 has potential as an effective adsorbent for removing copper from aqueous solution.
Melaleuca cajuputi and Acacia auriculiformis trees are major sources of nectar and pollen for Apis dorsata and the colonies are a major source of honey to the rural poor, honey hunters. Honey is a supplementary income to many of these people (including school children) in the Marang district, Terengganu. In this study, Marang area with 270 square kilometers was chosen as pilot study area in Terengganu state for mapping M. cajuputi and A. auriculiformis as two dominant species in low land secondary forest in Terengganu state.To inventory and produce land use map of Melaleuca forest in Marang area, in this study SPOT-5 satellite image in multispectral mode with 10 meter resolution which is acquired in 2007 as optical satellite was utilized. Most images from optical satellites have some null data from ground because of clouds and shadow of clouds. To solve this problem, Hue, Saturation and value (HSV) and Principal Component Analysis (PCA) were used as fusion techniques to replace null data with microwave data which taken from Radarsat-1 image in C-band with 25 meter resolution image. Accordingly, fusion technique which was used in this research not only was a technique to improve information but also caused the accuracy increasing than land use map by just only SPOT-5 image. Also between two different fusion techniques, PCA shows the better result than HSV as two different fusion techniques.
Background: Social support is the perception that one is cared for, has assistance available from friends and significant others. Social support can be measured by The Multidimensional Scale of Perceived Social Support. This scale has been widely used and validated in different languages. Objective: To determine the factor structure of The Multidimensional Scale of Perceived Social Support scale and find its reliability. Method: The study was conducted in one of the Universities in Malaysia. The undergraduate students who volunteered to participate in the study were explained about the purpose of the study and implications. The English version of Multidimensional Scale of Perceived Social Support scale (MSPSS) that was administered. In all 313 undergraduate students were studied. Exploratory factor analysis, with varimax rotation, was applied to the data Results: The three factor solution accounted for 80.51 % of the total variance. The procedure output has an overall alpha of 0.921. Conclusion: The MSPSS appears to be good enough to be used in Malaysia however more studies are required.
Silver catfish (Pangasius sutchi) skin gelatin was extracted to determine the effects of extraction time on the functional properties of the gelatin in terms of solubility, protein solubility as a function of pH and sodium chloride concentration, emulsifying capacity and stability, water holding capacity, fat binding capacities and foaming properties. Silver catfish skins were washed in sodium chloride (NaCl) solution prior to pre-treatment in sodium hydroxide (NaOH) and acetic acid solution. Gelatin was extracted at 50ºC for 6, 8, 10 and 12 hours extraction time followed by freeze drying. The extraction of silver catfish skin gelatin at 50 ºC for 12 hours was more effective than extraction at 6, 8 and 10 hours where the gelatin was characterized by higher emulsifying capacity (52.63%), emulsifying stability (47.83%), water holding capacity (31.78 mL/g), fat binding capacities (54.76%), foaming capacity (41.47 mL) and foaming stability (56.42%) than gelatins extracted at other extraction time. The longer the extraction time, the better the functional properties of the gelatin. Based on its good functional properties, silver catfish skin gelatin may be useful in various food applications such as soups, sauces and gravies.