Garlic has been a favorite additive in food for many years in various cultures. It is known that garlic
(Allium sativum) possesses antimicrobial, antiprotozoal, antimutagenic, antiplatelet and antihyperlipidemic
properties. Allicin, a thiosulfinate extract of garlic, has been presumed to be a very strong antioxidant. High performance liquid chromatography (HPLC) analysis of raw garlic extract was not conclusive to determine allicin’s presence. However, using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging methods to determine the antioxidant activity of raw garlic extract shows a color change from deep violet to yellow, indicating antioxidant activity. Thus, raw garlic can be a source of antioxidant based on the results of the DPPH scavenging analysis.
Matched MeSH terms: Chromatography, High Pressure Liquid
Characterization and quantification of carotenoid compound is complicated, costly and timeconsuming. The accuracy and reliability of the data depend solely on the standard and to High Performance Liquid Chromatography (HPLC) analysis but the major constraint is to acquire and to maintain the pure standards. Carotenoid standards are commercially available but they are expensive and are prone to isomerization and oxidation. Thus, the purpose of this study is to establish an analytical method for isolating β-carotene by using open column chromatography (OCC) from pumpkin (Cucurbita moschata) to be used as one of the carotenoid standards for determination of total and individual carotenoid. Pumpkin with orange flesh has been chosen due to the non-seasonal nature and its availability all year-round. This study demonstrated that the purity of β-carotene standard; determined by HPLC was ranged from 92.21 to 97.95%. The standard curves with five different concentrations of β-carotene extract from pumpkins in triplicate were constructed by plotting the peak area against the concentration. The coefficient of correlation was 0.9936. Therefore, this study established that pumpkin can be a reliable source of beta-carotene standard as it is cheap and commonly available throughout the year.
Matched MeSH terms: Chromatography, High Pressure Liquid
Glaucoma, recognized as optic neuropathy is the second largest cause of blindness worldwide. The disease is characterized by progressive loss of retinal ganglion cells and visual field defects. The pathophysiological factors involved in the onset and progression of glaucoma are not fully understood. However, it is now well accepted that elevated intraocular pressure is not the only causative factor. The pathophysiology of glaucoma involves multiple factors that interact in a highly complex manner to favor development of glaucomatous optic neuropathy. As the knowledge of molecular mechanisms involved is expanding, more and more therapeutic targets are being recognized for the development of safe and effective pharmacotherapy of glaucoma. Although at present the intraocular pressure lowering drugs are still the first line of treatment, the prospect of introducing neuroprotective therapies that can directly protect and perhaps stimulate regeneration of dying and dead retinal ganglion cells, shows considerable promise. This review presents recent developments in the pathophysiology and pharmacotherapy of glaucoma.
The level of total lipid and oryzanol content, an important antioxidant compound in locally produced bran was investigated. Total lipid in rice bran was extracted using 3:2 chloroform:methanol mixture yielding 16.4% fat. Oryzanol content was determined without saponification using a reverse-phase HPLC. Four fractions of oryzanol were successfully separated and quantitated. The 4 isomers were cycloartenyl ferulate, 24-methylene cycloartanyl ferulate, campestryl ferulate and mixtures of β–sitosteryl ferulate and cycloartanyl ferulate. The oryzanol content of local mixed varieties ranged from 23.7–43.0 mg g-1. The oryzanol concentration may depend on factors such as plant varieties, processing methods employed, extracting solvent used and ratio of extracting solvent to bran as well as extracting solvent temperatures. This study showed the potential of oryzanol extract from rice bran as a source of antioxidant.
Matched MeSH terms: Chromatography, High Pressure Liquid
Keupayaan Centella asiatica (CA) untuk bertindak sebagai antioksidan dan agen anti-radang telah banyak dilaporkan. Namun begitu, kaedah pengekstrakan CA untuk memperoleh hasil yang terbaik masih dipersoalkan. Dalam kajian ini, kami menilai tiga kaedah pengekstrakan CA dan membuat perbandingan ekstrak dari segi aktiviti antioksidan dan anti-radang, dan juga kandungan sebatian bioaktif, asiaticoside dan madecassoside. Centella asiatica diekstrak menggunakan pelarut etanol, metanol dan juga air. Kandungan sebatian fenolik ekstrak diukur menggunakan kaedah reagen Folin-Ciocalteu. Kandungan asiaticoside dan madecassoside ditentukan dengan kaedah HPLC. Aktiviti antioksidan diukur dengan asai 2,2-diphenyl-1-picrylhydrazyl (DPPH) dan asai penurunan kuasa Ferric Reducing Antioxidant Power (FRAP). Aktiviti anti-radang ditentukan dengan kebolehan ekstrak untuk merencatkan enzim tapakjalan keradangan, COX-1 dan COX-2, serta kebolehan ekstrak melindungi sel fibroblas aruhan 12-O-tetradecanoylphorbol-13-acetate (TPA) daripada menghasilkan prostaglandin E2 (PGE2 ). Hasil kajian menunjukkan aras sebatian fenolik, asiaticoside dan madecassoside tertinggi dalam ekstrak etanol, diikuti metanol dan esktrak akues (masing-masing 17.76 g/100g, 15.52 g/100g, 13.16 g/100g untuk sebatian fenolik, 42.86 mg/g, 36.37 mg/g, 2.82 mg/g untuk asiaticoside and 18.66 mg/g, 15.87 mg/g, 3.75 mg/g untuk madecassoside). Ketiga-tiga ekstrak menunjukkan aktiviti antioksidan sederhana berbanding kawalan positif. Kesemua ekstrak, asiaticoside dan madecassoside merencat COX-1 dan COX-2 dan menyekat penghasilan PGE2 -aruhan TPA. Ekstrak etanol dan metanol merupakan perencat COX yang lebih kuat dan lebih poten daripada ekstrak akues. Oleh itu, walaupun ekstrak akues menunjukkan kebolehan antioksidan yang lebih tinggi, dari segi aktiviti anti-radang, pelarut hidrofobik iaitu etanol dan metanol ternyata lebih baik untuk mengekstrak Centella asiatica.
Matched MeSH terms: Chromatography, High Pressure Liquid
The treatment of large ulcers is a problem. Closure with flaps and even skin grafts in compromised patients is often fraught with risks. Dressing these large wounds is also a problem, as they are often heavily exudative. We report our experience using the vacuum-assisted closure technique in managing difficult ulcers in four patients. A modification of the technique using cheap, easily available materials is described. The vacuum-assisted suction is an effective treatment for large ulcers in compromised patients. It facilitates considerable contraction of the wound, and in smaller wounds; the vacuum-assisted closure allows sufficient contracture to enable delayed primary closure. We recommend the use of this method of wound dressing and closure in large wounds particularly, in high-risk patients where extensive flap coverage or even split skin graft would incur considerable risk.
Thermodynamic chemical equilibrium analysis using, total Gibbs energy minimization method, was carried out for methane oxidation to higher hydrocarbons. For a large methane conversion and a high selectivity to higher hydrocarbons, the system temperature and oxygen concentration played a vital role, whereas, the system pressure only slightly influenced the two variables. Numerical results showed that the conversion of methane increased with the concentration of oxygen and reaction temperature, but it decreased with pressure. Nevertheless, the presence of oxygen suppressed the formation of higher hydrocarbons which mostly consisted of aromatics, but enhanced the formation of hydrogen. As the system pressure increased, the aromatics, olefins and hydrogen yields diminished, but the paraffin yield improved. Carbon monoxide seemed to be the major oxygen-containing equilibrium product from methane oxidation, whilst almost no H2O, CH3OH and HCOH were detected although traces amount of carbon dioxide were formed at relatively lower temperature and higher pressure. The total Gibbs energy minimization method is useful to theoretically analyze the feasibility of methane conversion to higher hydrocarbons and syngas at the selected temperature and pressure.
The extraction of phenolics from Citrus hystrix leaf was carried out using supercritical fluid extraction and was optimized using response surface methodology (RSM). The effects of CO2 flow rate, extraction pressure and extraction temperature on yield, total phenolic content and diphenyl-picrylhydrazyl-IC50 were evaluated and compared with ethanol extraction. The extraction pressure was the most significant factor affecting the yield, TPC and DPPH-IC50 of the extracts, followed by CO2 flow rate and the extraction temperature. The optimum conditions of pressure, CO2 flow rate and temperature were at 267 bars, 18 g/min and 50°C, respectively. The yield, TPC and DPPH-IC50 obtained were 5.06%, 116.53 mg GAE/g extract and IC50 of 0.063 mg/ml, respectively. These values were not significantly different (p
Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD) analysis were performed in this work in order to obtain the best design for safety and aerodynamic performance of the bicycle cycling helmet. FEA analysis was computed on two different helmet designs to determine the critical area subjected to impact. A pressure load was applied on the helmets’ outer surface to simulate oblique loading. The critical areas of the helmets were then highlighted and identified, enabling design improvements to be made on both designs. CFD analysis was then executed in order to obtain the lowest drag coefficient number in reducing the air resistance induced by both of the helmet designs, inherently increasing cyclist performance and ensuring competition success.
Chronic obstructive pulmonary disease (COPD) patients are reported to have cardiovascular instability which leads to greater limitation for activities there by leads to poor quality of life. Physical training proved to be one of the moderators of these limitations. However, uncertainty prevails among the protocol and duration. The present study investigated the effect of physical training on blood pressure, heart rate and Rate pressure Product (RPP) among COPD patients. A total of thirty COPD patients aged between 40 to 55 years were recruited for the study based on the inclusion and exclusion criteria and were assigned in to experimental group (15 patients) and control group (15 patients). The mean difference of blood pressure, heart rate and RPP were analyzed using paired t-test. There was significant difference between the pre and post test values of all parameters between experimental and control group with p< 0.05. Diastolic blood pressure showed to be less significant compared to the systolic blood pressure. This showed that specifically designed physical improved the cardiovascular fitness among COPD patients.
etrocaval ureter is a relatively rare anomaly where ureteric obstruction may occur as a result of ureter passes behind the inferior vena cava (IVC), hence, compressing it between the IVC and the vertebrae. We report 2 cases of retrocaval ureter with different presentations. One patient was managed surgically with minimally invasive approach and the other was managed conservatively.
Anion clay hydrotalcite MgA1C0 3 with a Mg/A1 molar ratio of 3:1 was synthesized by co-precipitation at room temperature and pressure. The physicochemical properties were evaluated using Powder X-Ray Diffraction (PXRD), Fourier Transform Infrared (FTIR) spectroscopy and Thermogravimetric Analysis (TGA). The efficacy of anion clay hydrotalcite in the removal ofCcf- from aqueous solutions was investigated with respect to contact time, initial concentration, pH, adsorbent dosage and temperature. The Cd2- removal increased with the increased in contact time, adsorbent dosage, pH and initial concentration. Adsorption decreases with increasing initial concentration and temperature, for which the latter is indicative of an exothermic process. The equilibrium adsorption capacity of MgA1C0 3 was evaluated using linear Langmuir and Freundlich isotherms with respect to the separation factor, RL.
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.
A Pressurized Liquid Extraction (PLE) method was developed by using conventional High Performance
Liquid Chromatography (HPLC). It was found that all of the PAHs have been successfully extracted with dichloromethane-acetone with high percentage recovery. A high temperature of 180°C gave the highest recovery for fluoranthene (94.4%). Meanwhile, fluorene showed the highest recovery at 150 bar, with 94.6% recovery. It is noted that there is no significant day-to-day difference in the efficiency of the developed method, with the R.S.D. values averaging at 0.02. The optimized conditions applied to the soil samples were analysed using the High Temperature High Performance Liquid Chromatography (HT-HPLC) with chromatographic conditions: Octadecylsilyl-silica (ODSsilica) column (100 mm × 4.6 mm I.D.); mobile phase acetonitrile:water 40:60 (v/v); flow rate 2.5 mL/min; temperature 70°C; UV absorbance 254 nm; injection volume 5µL.
Matched MeSH terms: Chromatography, High Pressure Liquid
In nature, environmental factors highly influence the carotenoid composition in pumpkin plants and these factors were difficult to control; thus, carotenoid content is varied quantitatively and qualitatively. However, certain parameters can be controlled and this can be conducted in the laboratory through biogenesis manipulation. This approach uses environmental stress as a tool to alter the carotenoid pathway in the plants. The main objective of this study was to observe the inhibiting and enhancing effect of abiotic stress on individual carotenoid accumulation in pumpkin plants under light and dark conditions. The abiotic stresses used were plant elicitors which consisted of Ultra Violet light exposure, Polyethylene Glycol 4000, Salicylic Acid, and half strength nutrients using Murashige and Skoog Salt. After two weeks of treatments, the pumpkin leaves and stems were harvested, freeze dried and extracted to determine the carotenoids compound using High-Performance Liquid Chromatography (HPLC). Results showed that there was a significant difference (p
Matched MeSH terms: Chromatography, High Pressure Liquid
Aluminium foam tube is a metal that consists of porous medium with special characteristics such as good energy absorption, good heat transfer and high thermal conductivity. These make it suitable to be used in a wide range of applications such as in heat exchangers. The aim of this project is to identify and analyse mechanical behaviour and microstructure aluminium foam tube produced and fabricated with infiltration method with vacuum-gas. The density of aluminium foam tube was also determined and an average aluminium foam tube with porosity 50% - 80% with the average NaCl particle size 2mm, 3mm and 4mm was produced. Foams with porosity 60%-75% NaCl has higher energy absorption. These was based on foam structure, density and maximum compressive load test result.
A study has been conducted on trans,trans-muconic acid (t,t-MA) as the biomarker for benzene exposure among
oil and gas petrol tanker drivers. The objectives of this study are to determine the significant difference and the
correlation between Benzene personal exposure and urinary t,t-MA among exposed and non-exposed workers. A total
of 92 questionnaires were distributed to obtain demographic and descriptive data. Benzene personal exposure was
sampled using SKC passive samplers and the data was analyzed using GC-FID. Urinary t,t-MA was collected at end of
work shift and analyzed using HPLC-UV detector. A total of 30 non-exposed workers were also sampled. The averages
of urinary t,t-MA were 96.65 ug/g creatinine for exposed workers and 0.51 ug/g creatinine for non-exposed workers.
Meanwhile, the averages of Benzene personal exposure were 0.37 mg/m3 and 0.01 mg/m3 for exposed workers and
non-exposed workers respectively. No significant correlation was found between exposure to benzene with excreted
urinary t,t-MA of workers occupationally exposed (p-value > 0.05) as well as to workers non-exposed to benzene
(p-value > 0.05). In conclusion, there is no significant correlation found between Benzene personal exposure and
urinary t,t-MA among exposed and non-exposed workers. Applicability of using t,t-MA as the biomarker of benzene
exposure shall be further discussed with all the other confounding factors to be taken into account.
Matched MeSH terms: Chromatography, High Pressure Liquid
Pineapple waste is a by-product resulting from canning processing of pineapple that produce about 35% of fruit waste and lead to serious environmental pollution. Pineapple waste contains valuable nutrient components of simple sugar such as sucrose, glucose and fructose. Analysis of sugar content is important for further processing such as fermentation. The aim of this study was to determine the amount of sugar in different parts of pineapple waste (peel, core and crown) from variety N36. The selected pineapple waste for maturity indices 1, 2 and 3 was cut into small pieces before crushed in a food processor. The crushed waste was then filtered through muslin cloth followed by membrane filter 0.45μm to produce pineapple waste extract. Sugar content was determined using High Performance Liquid Chromatography. It was found that fructose content was significantly higher in core (2.24%) followed by peel (2.04%) and crown (0.87%). It was also found that glucose content was significantly higher in core (2.56%) followed by peel (2.18%) and crown (0.53%). Significant difference (p < 0.05) was found for sucrose content between pineapple core and peel extract with the value of 8.92% and 3.87%, respectively. However, sucrose was not detected in pineapple crown. It means that pineapple core extract had the highest values of fructose, glucose and sucrose compared to the other parts of pineapple waste extract. Besides, it was found that sucrose content was significantly higher in pineapple core for index 3 as compared to indices 1 and 2. Glucose and fructose was significantly higher in pineapple core for index 2 compared to indices 1 and 3.
Matched MeSH terms: Chromatography, High Pressure Liquid
Leaves from three varieties of Ficus deltoidea, colloquially termed small- (FDS), medium- (FDM), and big-type leaf (FDB), were subjected to water extraction. The crude extracts were fractionated using water (WF) and ethyl acetate (EAF). The phenolic and flavonoid content, antioxidant activity, and cytotoxicity of the fractions were investigated. The EAF had the highest phenolic and flavonoid content compared to the other FDS fractions. Conversely, the FDM crude extract had the highest phenolic and flavonoid content compared to the other FDM samples. Antioxidant activity was highest in the FDB crude extract. Ultra-high-performance liquid chromatography showed that two compounds, vitexin and coumaric acid, were present in the FDB crude extract. Additionally, the F. deltoidea leaves caused no signs of toxicity in a normal liver cell line. Our findings show that F. deltoidea varieties have excellent antioxidant activity with no cytotoxic effects on normal liver cells.
Matched MeSH terms: Chromatography, High Pressure Liquid
Cloud point extraction (CPE) is a separation and preconcentration of non-ionic surfactant from one liquid phase to another. In this study, Sylgard 309 and three different types of additives for CPE, namely CPE-Sylgard, CPE-Sylgard-BMIMBr and CPE-Sylgard-GLDA, are investigated to extract methylphenol from water samples. The methylphenols are well separated by reversed-phase high-performance liquid chromatography (HPLC) with isocratic elution of acetonitrile : water; 60 : 40 (v/v) and detection at 260 nm. The optimized parameters for the effect of salt, surfactant, temperature, time of extraction, pH, interference study and the performance of different additives on methylphenol extraction are investigated. CPE-Sylgard-GLDA is chosen because it gives us a high peak and good peak area compared with CPE-Sylgard and CPE-Sylgard-BMIMBr. The recovery extractions of CPE-Sylgard-GLDA are obtained in the range of 80-99% as the percentage of relative standard deviation (RSD) is less than 10. The LOD and LOQ are 0.05 ppm and 0.18 ppm, respectively. The method developed for CPE-Sylgard-GLDA coupled with HPLC is feasible for the determination of methylphenol because it is simple, effective, cheap, and produces a high percentage of recovery.
Matched MeSH terms: Chromatography, High Pressure Liquid