Material designs that use donor and acceptor units are often found in organic optoelectronic devices. Molecular level insight into the interactions between donors and acceptors are crucial for understanding how such interactions can modify the optical properties of the organic optoelectronic materials. In this paper, tris(4-(tert-butyl)phenyl)amine (pTPA) was synthesized as a donor in order to compare with unmodified triphenylamine (TPA) in a donor-acceptor system by having 2,4,6-triphenyl-1,3,5-triazine (TRZ) as an acceptor. Dimerization of donors and acceptors occurred in solvent when the concentration of solute is high. At 0 K, using a polarizable continuum model, the nitrogen atom of TPA is found to stack on top of the center of triazine of TRZ, whereas such alignment is offset in pTPA and TRZ. We attributed such alignment in TPA-TRZ as the result of attractive interactions between partial localization of 2pz electrons at the nitrogen atom of TPA and the π deficiency of triazine in TPA-TRZ. By taking into account random motions of the solvent effect at 300 K in quantum molecular dynamics and classical molecular dynamics simulations to interpret the marked difference in emission spectra between TPA-TRZ and pTPA-TRZ, it was revealed that the attractive interaction between pTPA and TRZ in toluene is weaker than TPA and TRZ. Because of the weaker attractive interaction between pTPA and TRZ in toluene, the dimers adopted numerous ground state conformations resulting in broad emission bands superimposed with multiple small Gaussian peaks. This is in contrast to TPA-TRZ which has only one dominant dimer conformation. This study demonstrates that the strength of intermolecular interactions between donors and acceptors should be taken into consideration in designing supramolecular structures.
Accidental poisoning in children is a preventable condition. It is a problem mainly in children aged 1 to 4 years. This is a descriptive study of accidental poisoning in children below 12 years old admitted to Hospital Seremban from October 15, 1994 to October 14, 1995. A major cause of household accidental poisoning was kerosene ingestion (25%) followed by ingestion of medications (22%), liniment methyl salicylate (12 %), mothballs (12%) and hypochlorinate solution (9%). There was a higher incidence of poisoning in males (50.8%), among Indians (41.2%) and in children from lower social classes (67%). A greater proportion of the accident occurred when the child was taken care by the parents (53 %) and in the house (80%). Most of the poison was ingested from its original package (81%). The immediate action taken was sending the child to the hospital (75%) without carrying out other actions such as washing the child’s mouth. The delay of sending the child to hospital was due to husband not at home (57%). Most of the cases (72.1 %) were discharged well within 1-2 days following admission.
Introduction: Knowledge, attitude as well as adoption of pharmacogenomics in clinical practice among the pharmacists and physicians in Malaysia have not been reported. This cross-sectional study explores various facets of the two professions as related to pharmacogenomics to determine the need and preferred method to improve education among them. This study also aims to identify the current state of pharmacogenomics practice in Malaysia to help identify barrier and solution to reap advantages from pharmacogenomics practices. Methods: A questionnaire consisting of 38 questions in five parts was adopted and validated. It explores the respondents’ characteristics, attitude, knowledge, adoption and education. It was distributed online to 1500 pharmacists and physicians over five months. Results: Pharmacists differed from the physicians in terms of attitude, knowledge, adoption and education. Overall, adoption rate of pharmacogenomics was found to be low but its anticipation for future adoption is high, and benefits were reported by healthcare professionals who have used the test in a clinical setting. Majority of respondents had poor to fair knowledge and nearly half have had no prior formal teaching on pharmacogenomics. Interest in the education is very high, and most of them preferred to learn pharmacogenomics via continuous professional education programs. Conclusion: Pharmacogenomics is a field that promises many benefits, but to reap these benefits require its implementation in clinical setting. Pharmacists and physicians need to be equipped with adequate knowledge and positive attitude towards pharmacogenomics.
Utilization of palm kernel expeller (PKE), a palm oil milling by-product, may be diversified through the exploitation of its protein component. The PKE protein could be effectively extracted using an alkaline
solution and followed by enzymatic hydrolysis to produce PKE protein hydrolysates or crude PKE peptide. The extraction of PKE protein was successfully carried out using an alkaline solution at pH11, at ratio of 1:10 (g/ml), PKE powder to alkaline solution with continuous shaking, 150 rpm, in a water bath operating at 50°C for 30 min. The extracted protein powder (PKEP) had 68.50±3.08% crude protein, 0.54±0.03% fat and 0.73±0.02% ash. The freeze-dried PKEP was re-suspend in particular buffer and hydrolyzed with proteolytic enzymes (Alcalase® 2.4L, Flavourzyme® 500MG, pepsin or trypsin) to obtain PKEP hydrolysate (PKEPH). The effect of enzyme concentration (0, 2, 4, 6, 8 & 10%) and time of hydrolysis (0, 6, 12, 24, 48 h) was studied to determine the most efficient hydrolytic conditions. Results showed that all enzymes tested were capable of hydrolyzing the PKEP and producing hydrolysates with different degree of hydrolysis (DH%). At 8.0% concentration, Alcalase®2.4L hydrolyzed PKEP into the highest DH (75.96%) hydrolysate (PKEPH) after 1h hydrolysis. Although only with 2.0% Alcalase 2.4 L concentration, it was sufficient to produce PKEP hydrolysate of 81.35% DH %, but it required 12 h to hydrolyze the protein. Pepsin was relatively the least efficient protease to hydrolyze the PKEP.
This work aims at optimizing the media constituents for citric acid production from oil palm empty fruit bunches (EFB) as renewable resource using artificial neural networks (ANN) approach. The bioconversion process was done through solid state bioconversion using Aspergillus niger. ANN model was built using MATLAB software. A dataset consists of 20 runs from our previous work was used to develop ANN. The predictive and generalization ability of ANN and the results of RSM were compared. The determination coefficients (R2-value) for ANN and RSM models were 0.997 and 0.985, respectively, indicating the superiority of ANN in capturing the non-linear behavior of the system. Validation process was done and the maximum citric acid production (147.74 g/kg-EFB) was achieved using the optimal solution from ANN which consists of 6.1% sucrose, 9.2% mineral solution and 15.0% inoculum.
Microbial keratitis is one of the most challenging complications of contact lens (CL) wear. Proper CL practice plays an important role to reduce the risk for contact lens related microbial keratitis (CLRMK). Methods: This multi-centre case-control study was conducted from January 2008 until June 2009 to determine the risk factors associated with CLRMK. Cases were defined as respondents who were treated for CLRMK, whilst controls were respondents who were contact lens wearers without microbial keratitis. Ninety four cases were compared to 94 controls to determine the risk factors for
CLRMK. Results: The predictors for CLRMK were: Not washing hands with soap before handling CL (aOR 2.979, CI 1.020, 8.701 p=0.046), not performing rubbing technique whilst cleaning the CL (aOR 3.006, CI 1.198, 7.538 p=0.019) and, not cleaning the lens case with multipurpose solution daily (aOR 3.242 CI 1.463, 7.186 p=0.004). Sleeping overnight with the CL in the eye (aOR 2.864, CI 0.978, 8.386 p=0.049) and overall non-compliance with lens care procedures (aOR 2.590, CI 1.003, 6.689 p=0.049) contributed significantly to CLRMK. Conclusion: Health education and promotion in contact lens care are important and should be conducted by eye care practitioners to reduce the occurrence of CLRMK.
Pectins are a diverse family of biopolymers with an anionic polysaccharide backbone of α-1,4-linked d-galacturonic acids in common. They have been widely used as emulsifiers, gelling agents, glazing agents, stabilizers, and/or thickeners in food, pharmaceutical, personal care and polymer products. Commercial pectin is classified as high methoxy pectin (HMP) with a degree of methylation (DM) >50% and low methoxy pectin (LMP) with a DM <50%. Amidated low methoxy pectins (ALMP) can be obtained through aminolysis of HMP. Gelation of HMP occurs by cross-linking through hydrogen bonds and hydrophobic forces between the methyl groups, assisted by a high co-solute concentration and low pH. In contrast, gelation of LMP occurs by the formation of ionic linkages via calcium bridges between two carboxyl groups from two different chains in close proximity, known as the 'egg-box' model. Pectin gels exhibit Newtonian behaviour at low shear rates and shear-thinning behaviour when the shear rate is increased. An overview of pectin from its origin to its physicochemical properties is presented in this review.
Patient safety is a serious global healthcare issue. Harm can be caused by a range of errors or adverse events. Therefore, it is vital that the commissioning of a new operating theatre should comply to the highest standard before it is allowed to function. This paper accounts our experience in the commissioning of the University Malaya Medical Centre (UMMC) trauma centre operating theatre(OT) complex in July 2008. We highlighted the problems we faced in adhering to the international standard guidelines. Unanticipated events were handled professionally and solved. With this experience, we hope that the identified problems would provide suggestions for commissioning an operating theatre in the local setting in the future.
Texture evolution of NiO formed during oxidation of polycrystalline single oriented (100) Ni-Cr was investigated. This foil was also termed rolling assisted biaxially textured substrate (RABiTS). X-ray diffractograms of oxidized Ni-Cr RABiTS foil showed the existence of mostly (200) NiO indicating (100)-type NiO formed exclusively on (100) singly oriented Ni-Cr grains. Epitaxial relationship between the two layers is observed. However the dual-in-plane texture was recorded.
The in-plane texture was assessed by conducting phi scan and plotting series of pole figures measured at (111) NiO peak. The mechanism of the oxides formation was proposed to take into account the formation of (100)-type NiO. Cross section morphology of the oxidised foils reveals two oxidation layers; fast growing external layer consisting of the (100)-type NiO and an internal layer consisted of mostly Cr2O3 and maybe NiCr2O4. The thickness of NiO was ~ 10Pm. Cr2O3 formed as needle-like oxides embedded in a matrix of Ni foil. Inward diffusion of oxygen is believed to have caused this to happen. The external NiO layer was consisted of duplex microstructure characterised by columnar layer growing vertical on the surface of the metal and a few micron thick of equiaxed NiO. Delamination of the outer NiO layer often occurred at the columnarequiaxed interface which could be cured by CeO2 deposition on the foil prior to the oxidation process. CeO2 was deposited by conversion immersion using Ce(NO3)3.6H2O solution. (200) NiO formed on this coated sample as well.
Tetragonal Y2O3 stabilized Zirconia (t-Y-ZrO2) powders were doped with Nb2O5 to seek a possibility if electronics doping would enhance the electronics conductivity of the insulating oxide. In this work Y2O3 was added as a stabilizer to produce tetragonal ZrO2 whereas Nb2O5 was added for the electronic doping. Several compositions of powders were prepared by thermal decomposition method and were post annealed at different temperatures. Precursor solutions were prepared from the mixture of zirconyl nitrate, yttrium nitrate and niobium tartarate as well as TEA (triethanolamine). The mixed solution were evaporated, pyrolysed and calcined to produce nanosized powders. The phase formation of the as-made powders was investigated by x-ray diffractometer. The additions of 7% Y2O3 were found to stabilize the tetragonal phase of zirconia.
The addition of Nb2O5 did not alter the stability of the tetragonal phase but it was found that the conductivity of the material has changed. The band gap as measured by the UV-Visible Spectrometer gave a value in the range of 2.97 to 5.01 eV. XRD was also used to deduce the crystallite size (by using Scherer’s equation) and transmission electron microcopy was used to view the particle sizes and shapes. The Nb doped t-Y-ZrO2 prepared in this work was to be nanosized crystal with size ranges from 7 nm to 15 nm.
The agricultural industry scenario in many industrialized countries has adopted an image processing system as a solution to automate the grading process in order to provide accurate, reliable, consistent and quantitative information in addition to the large volumes, which human graders are not able to perform. In Malaysia, the grading of palm oil Fresh Fruit Bunches (FFB) is still performed manually through visual inspection using the surface color as the main quality attribute. It is the intention here to introduce an automated grading system for palm oil FFB using a computer assisted photogrammetric methodology which correlate the surface color of fruit bunches, not the fruitlets, to their ripeness and eventually sorts the fruit to two predefined fruit categories. The methodology consists of five main phases, i.e. image acquisition, image pre-processing, image segmentation, calculation of color Digital Numbers (DN) (data manipulation) and finally the classification of ripeness. This computerized photogrammetric image processing technique using MATLAB® package which is integrated to a sorting system differs in various aspects from other digital imaging technique or machine vision system adopted for classifying fruit ripeness. A comprehensive discussion will be presented based on the results achieved through actual fruit testing on the prototype grading system. The main concern was to ensure the reliability of the computerized photogrammetric technique achievable and the system’s mechanism working as intended. The fruit classification ability of the system yields above 90% accuracy and taking not more than 25 seconds to classify and sort each fruit.
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.
Fifty Non Insulin Dependent Diabetes Mellitus (NIDDM) patients undergoing surgery under epidural anaesthesia were studied. All patients received dextrose 5% infusion at 100 ml/hr from the period of fasting until upon arrival to the operation room. Patients were randomly divided into two groups. Patients in Group 1 (n=25) received normal saline while patients in Group 2 (n=25) were given Ringer’s lactate. Both groups received their infusion throughout the operative period up to four hours postoperatively. Blood glucose level was measured at baseline, 45 minutes intra operatively and postoperatively at 30 minutes and four hours by using a glucometer. Patients in Group 2 has a larger mean increase in blood glucose level of 1.5 mmol/L between 4 hours postoperatively and baseline compared to 0.96 mmol/L in Group 1. However, this was not statistically significant. There was no difference in the increase of mean glucose level at 30 minutes when compared to baseline. There was a significant increase in mean blood glucose level in both groups in the postoperative period when compared to baseline. This study demonstrated that patients with NIDDM receiving Ringer’s lactate has a larger increase in mean blood glucose level compared to those receiving normal saline, but the magnitude is not statistically significant.
This was a prospective randomized double blind controlled study to compare intubating conditions at 60 seconds with rocuronium 0.6 mg/kg by using three different induction techniques: propofol-placebo (PP), propofol-ephedrine (PE) and propofol-placebo-crystalloid (PC). Ninety patients were included and randomly allocated to receive one of the three combinations. The patients were induced using fentanyl 2 µg/kg, followed by propofol 2.5 mg/kg with normal saline as placebo (Group PP and Group PC) or ephedrine 70 µg/kg (Group PE) given over 30 seconds. Subsequently, rocuronium 0.6 mg/kg was given over five seconds and endotracheal intubations were performed 60 seconds later. Intubating conditions were clinically acceptable in all patients except in four patients in PP group, who had poor intubating conditions. The proportion of excellent intubating conditions was significantly highest in Group PE (94%) followed by Group PC (81%) and lowest in Group PP (50%). In conclusion, induction with propofol-ephedrine and propofol-placebo-crystalloid combinations rovided significantly better intubating conditions than propofol alone, when rocuronium 0.6 mg/kg was used for intubation at 60 seconds.
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
Lymphangiomas are hamartomatous congenital malformations of the lymphatic system that usually involve subcutaneous tissues of cervico-facial region. Rarely, it can be found in subcutaneous tissue of proximal extremities, the buttocks and the trunk. Magnetic Resonance Imaging (MRI) is the best modality to assess the tumor specification and extension. We report a case of lymphangioma at a rare site with its radiological features and patient responsed to the sclerosant therapy.
Cervico facial cystic hygroma and tongue lymphagioma is rare representative of spectrum of lymphatic malformations. Conservative management with sclerosants alone has proven to be successful. However, sudden enlargement of these cervico facial lymphangiomas leads to catastrophic airway obstruction leading to debility in feeding and speech. Therefore, surgery is indicated in such case to prevent such a catastrophic problem. We report here the case of a 3-yearold boy with cervico facial hygroma involving the tongue. We successfully treated him with a combination of surgery and OK432 injection.
Lovastatin (LVS) is an effective therapeutic and prophylactic agent in several cardiovascular disorders. However, it has low bioavailability. This study investigated solute-solvent and solute-cosolute interactions and assessed thermodynamic parameters that contributed to LVS solubility enhancement in the presence of arginine (ARG) as a hydrotropic agent. The electrolytic conductance of LVS-ARG binary system was measured at temperatures from 298.15 K to 313.15 K. Conductometric parameters such as limiting molar conductance was evaluated. Additionally, thermodynamic parameters (ΔG0, ΔH0, ΔS0 and ES) involved in the association process of the solute in the aqueous solution of ARG solution were determined systematically. Solubility markedly improved 43-fold in the LVS-ARG complex compared to LVS alone. The analysed data from values of molar conductance and activation energy suggested favourable solubilisation, with a stronger solute-solvent interaction between LVS-ARG in water at higher temperatures. ARG and LVS complexation caused by strong molecular interactions was confirmed by spectral results. Hence, the addition of ARG as a co-solute was proven to enhance LVS solubility in water. The obtained data will ultimately enable the development of desired highly soluble, more efficient and safer LVS preparations.
In this work, a novel membrane crystallization system was used to crystallize micro-sized seeds of piroxicam monohydrate by reverse antisolvent addition. Membrane crystallization seeds were compared with seeds produced by conventional antisolvent addition and polymorphic transformation of a fine powdered sample of piroxicam form I in water. The membrane crystallization process allowed for a consistent production of pure monohydrate crystals with narrow size distribution and without significant agglomeration. The seeds were grown in 350 g of 20:80w/wacetone-water mixture. Different seeding loads were tested and temperature cycling was applied in order to avoid agglomeration of the growing crystals during the process. Focused beam reflectance measurement (FBRM); and particle vision and measurement (PVM) were used to monitor crystal growth; nucleation and agglomeration during the seeded experiments. Furthermore; Raman spectroscopy was used to monitor solute concentration and estimate the overall yield of the process. Membrane crystallization was proved to be the most convenient and consistent method to produce seeds of highly agglomerating compounds; which can be grown via cooling crystallization and temperature cycling.