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Anti-inflammatory and analgesic effects of ketoprofen in palm oil esters nanoemulsion

Sakeena MH, Yam MF, Elrashid SM, Munavvar AS, Azmin MN

J Oleo Sci, 2010;59(12):667-71.
PMID: 21099145

Ketoprofen is a potent non-steroidal anti-inflammatory drug has been used in the treatment of various kinds of pains, inflammation and arthritis. However, oral administration of ketoprofen produces serious gastrointestinal adverse effects. One of the promising methods to overcome these adverse effects is to administer the drug through the skin. The aim of the present work is to evaluate the anti-inflammatory and analgesic effects from topically applied ketoprofen entrapped palm oil esters (POEs) based nanoemulsion and to compare with market ketoprofen product, Fastum(®) gel. The novelty of this study is, use of POEs for the oil phase of nanoemulsion. The anti-inflammatory and analgesic studies were performed on rats by carrageenan-induced rat hind paw edema test and carrageenan-induced hyperalgesia pain threshold test to compare the ketoprofen entrapped POEs based nanoemulsion formulation and market formulation. Results indicated that there are no significant different between ketoprofen entrapped POEs nanoemulsion and market formulation in carrageenan-induced rat hind paw edema study and carrageenan-induced hyperalgesia pain threshold study. However, it shows a significant different between POEs nanoemulsion formulation and control group in these studies at p<0.05. From these results it was concluded that the developed nanoemulsion have great potential for topical application of ketoprofen.

Matched MeSH terms: Analgesics/chemistry; Anti-Inflammatory Agents, Non-Steroidal/chemistry; Emulsions/chemistry; Esters/chemistry*; Ketoprofen/chemistry; Plant Oils/chemistry*; Nanostructures/chemistry*
Enzymatic synthesis of palm olein-based fatty thiohydroxamic acids

Al-Mulla EA, Yunus WM, Ibrahim NA, Rahman MZ

J Oleo Sci, 2010;59(11):569-73.
PMID: 20972356

Fatty thiohydroxamic acids (FTAs) have been successfully synthesized from palm olein and thiohydroxamic acid by a one-step lipase catalyzed reaction. The use of immobilized lipase (Lipozyme RMIM) as the catalyst for the preparation reaction provides an easy isolation of the enzyme from the products and other components in the reaction mixture. The FTAs were characterized using Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance ((1)H NMR) technique and elemental analysis. The highest conversion percentage (95 %) was obtained when the process was carried out for 30 hours using urea to palm oil ratio of 6.0: 1.0 at 40 °C. The method employed offers several advantages such as renewable and abundant of the raw material, simple reaction procedure, environmentally friendly process and high yield of the product.

Matched MeSH terms: Hydroxamic Acids/chemistry
Soy sauce and its umami taste: a link from the past to current situation

Lioe HN, Selamat J, Yasuda M

J Food Sci, 2010 Apr;75(3):R71-6.
PMID: 20492309 DOI: 10.1111/j.1750-3841.2010.01529.x

Soy sauce taste has become a focus of umami taste research. Umami taste is a 5th basic taste, which is associated to a palatable and pleasurable taste of food. Soy sauce has been used as an umami seasoning since the ancient time in Asia. The complex fermentation process occurred to soy beans, as the raw material in the soy sauce production, gives a distinct delicious taste. The recent investigation on Japanese and Indonesian soy sauces revealed that this taste is primarily due to umami components which have molecular weights lower than 500 Da. Free amino acids are the low molecular compounds that have an important role to the taste, in the presence of sodium salt. The intense umami taste found in the soy sauces may also be a result from the interaction between umami components and other tastants. Small peptides are also present, but have very low, almost undetected umami taste intensities investigated in their fractions.

Matched MeSH terms: Flavoring Agents/chemistry
Fulltext Phytochemical and cytotoxic investigations of Alpinia mutica rhizomes

Malek SN, Phang CW, Ibrahim H, Norhanom AW, Sim KS

Molecules, 2011 Jan 14;16(1):583-9.
PMID: 21240148 DOI: 10.3390/molecules16010583

The methanol and fractionated extracts (hexane, ethyl acetate and water) of Alpinia mutica (Zingiberaceae) rhizomes were investigated for their cytotoxic effect against six human carcinoma cell lines, namely KB, MCF7, A549, Caski, HCT116, HT29 and non-human fibroblast cell line (MRC 5) using an in vitro cytotoxicity assay. The ethyl acetate extract possessed high inhibitory effect against KB, MCF7 and Caski cells (IC₅₀ values of 9.4, 19.7 and 19.8 µg/mL, respectively). Flavokawin B (1), 5,6-dehydrokawain (2), pinostrobin chalcone (3) and alpinetin (4), isolated from the active ethyl acetate extract were also evaluated for their cytotoxic activity. Of these, pinostrobin chalcone (3) and alpinetin (4) were isolated from this plant for the first time. Pinostrobin chalcone (3) displayed very remarkable cytotoxic activity against the tested human cancer cells, such as KB, MCF7 and Caski cells (IC₅₀ values of 6.2, 7.3 and 7.7 µg/mL, respectively). This is the first report of the cytotoxic activity of Alpinia mutica.

Matched MeSH terms: Alpinia/chemistry*
Investigation on thermochemical behaviour of low rank Malaysian coal, oil palm biomass and their blends during pyrolysis via thermogravimetric analysis (TGA)

Idris SS, Abd Rahman N, Ismail K, Alias AB, Abd Rashid Z, Aris MJ

Bioresour Technol, 2010 Jun;101(12):4584-92.
PMID: 20153633 DOI: 10.1016/j.biortech.2010.01.059

This study aims to investigate the behaviour of Malaysian sub-bituminous coal (Mukah Balingian), oil palm biomass (empty fruit bunches (EFB), kernel shell (PKS) and mesocarp fibre (PMF)) and their respective blends during pyrolysis using thermogravimetric analysis (TGA). The coal/palm biomass blends were prepared at six different weight ratios and experiments were carried out under dynamic conditions using nitrogen as inert gas at various heating rates to ramp the temperature from 25 degrees C to 900 degrees C. The derivative thermogravimetric (DTG) results show that thermal decomposition of EFB, PMF and PKS exhibit one, two and three distinct evolution profiles, respectively. Apparently, the thermal profiles of the coal/oil palm biomass blends appear to correlate with the percentage of biomass added in the blends, thus, suggesting lack of interaction between the coal and palm biomass. First-order reaction model were used to determine the kinetics parameters for the pyrolysis of coal, palm biomass and their respective blends.

Matched MeSH terms: Plant Oils/chemistry*
Fulltext Classification of agarwood oil using an electronic nose

Hidayat W, Shakaff AY, Ahmad MN, Adom AH

Sensors (Basel), 2010;10(5):4675-85.
PMID: 22399899 DOI: 10.3390/s100504675

Presently, the quality assurance of agarwood oil is performed by sensory panels which has significant drawbacks in terms of objectivity and repeatability. In this paper, it is shown how an electronic nose (e-nose) may be successfully utilised for the classification of agarwood oil. Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA), were used to classify different types of oil. The HCA produced a dendrogram showing the separation of e-nose data into three different groups of oils. The PCA scatter plot revealed a distinct separation between the three groups. An Artificial Neural Network (ANN) was used for a better prediction of unknown samples.

Matched MeSH terms: Thymelaeaceae/chemistry*
Survey of aflatoxins in retail samples of whole and ground black and white peppercorns

Adzahan N, Jalili M, Jinap S

Food Addit Contam Part B Surveill, 2009;2(2):178-82.
PMID: 24785182 DOI: 10.1080/19440040903384190

A total of 126 local and imported samples of commercial white and black pepper in Malaysia were analysed for aflatoxins B1, B2, G1 and G2 (AFB1, AFB2, AFG1, AFG2) content using high-performance liquid chromatography (HPLC) with a fluorescence detector (FD). An acetonitrile-methanol-water (17 : 29 : 54; v/v) mixture was used as a mobile phase and clean-up was using an immunoaffinity column (IAC). Seventy out of 126 (55.5%) samples were contaminated with total aflatoxins, although only low levels of aflatoxins were found ranging from 0.1 to 4.9 ng g(-1). Aflatoxin B1 showed the highest incidence of contamination and was found in all contaminated samples. There was a significant difference between type of samples and different brands (p < 0.05). The results showed black peppers were more contaminated than white peppers.

Matched MeSH terms: Piper nigrum/chemistry*
Mo (VI) reduction to molybdenum blue by Serratia marcescens strain Dr.Y9

Yunus SM, Hamim HM, Anas OM, Aripin SN, Arif SM

Pol J Microbiol, 2009;58(2):141-7.
PMID: 19824398

In this work we report on the isolation of a local molybdenum-reducing bacterium. The bacterium reduced molybdate or Mo(6+) to molybdenum blue (oxidation states between 5+ to 6+). Electron donors that supported cellular growth were sucrose, maltose, mannitol, fructose, glucose and starch (in decreasing order) with sucrose supporting formation of the highest amount of molybdenum blue at 10 g/l after 24 hours of static incubation. The optimum molybdate and phosphate concentrations that supported molybdate reduction were 20 and 5 mM, respectively. Molybdate reduction was optimal at 37 degrees C. The molybdenum blue produced from cellular reduction exhibited a unique absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. The isolate was tentatively identified as S. marcescens strain Dr.Y9 based on carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. No inhibition of molybdenum-reducing activity was seen using electron transport system (ETS) inhibitors such as antimycin A, 1HQNO (Hydroxyquinoline-N-Oxide), sodium azide and cyanide suggesting that the ETS of this bacterium is not the site of molybdate reduction.

Matched MeSH terms: Environmental Pollutants/chemistry
Optimization of processing parameters for the preparation of phytosterol microemulsions by the solvent displacement method

Leong WF, Che Man YB, Lai OM, Long K, Misran M, Tan CP

J Agric Food Chem, 2009 Sep 23;57(18):8426-33.
PMID: 19694442 DOI: 10.1021/jf901853y

The purpose of this study was to optimize the parameters involved in the production of water-soluble phytosterol microemulsions for use in the food industry. In this study, response surface methodology (RSM) was employed to model and optimize four of the processing parameters, namely, the number of cycles of high-pressure homogenization (1-9 cycles), the pressure used for high-pressure homogenization (100-500 bar), the evaporation temperature (30-70 degrees C), and the concentration ratio of microemulsions (1-5). All responses-particle size (PS), polydispersity index (PDI), and percent ethanol residual (%ER)-were well fit by a reduced cubic model obtained by multiple regression after manual elimination. The coefficient of determination (R(2)) and absolute average deviation (AAD) value for PS, PDI, and %ER were 0.9628 and 0.5398%, 0.9953 and 0.7077%, and 0.9989 and 1.0457%, respectively. The optimized processing parameters were 4.88 (approximately 5) homogenization cycles, homogenization pressure of 400 bar, evaporation temperature of 44.5 degrees C, and concentration ratio of microemulsions of 2.34 cycles (approximately 2 cycles) of high-pressure homogenization. The corresponding responses for the optimized preparation condition were a minimal particle size of 328 nm, minimal polydispersity index of 0.159, and <0.1% of ethanol residual. The chi-square test verified the model, whereby the experimental values of PS, PDI, and %ER agreed with the predicted values at a 0.05 level of significance.

Matched MeSH terms: Phytosterols/chemistry*
Fulltext Proficiency testing of Hb A1c: a 4-year experience in Taiwan and the Asian Pacific region

Shiesh SC, Wiedmeyer HM, Kao JT, Vasikaran SD, Lopez JB, Laboratory Management Committee for the Asian-Pacific Federation of Clinical Biochemistry

Clin Chem, 2009 Oct;55(10):1876-80.
PMID: 19617287 DOI: 10.1373/clinchem.2009.129726

BACKGROUND: The correlation between hemoglobin A(1c) (Hb A(1c)) and risk for complications in diabetic patients heightens the need to measure Hb A(1c) with accuracy. We evaluated the current performance for measuring Hb A(1c) in the Asian and Pacific region by examining data submitted by laboratories participating in the Taiwan proficiency-testing program.
METHODS: Five fresh-pooled blood samples were sent to participating laboratories twice each year. The results were evaluated against target values assigned by the National Glycohemoglobin Standardization Program network laboratories; a passing criterion of +/-7% of the target value was used. Measurement uncertainty at Hb A(1c) concentrations of 7.0% and 8.0% were determined.
RESULTS: A total of 276 laboratories from 11 countries took part in the Hb A(1c) survey. At the Hb A(1c) concentrations tested method-specific interlaboratory imprecision (CVs) were 1.1%-13.9% in 2005, 1.3%-10.1% in 2006, 1.2%-8.2% in 2007, and 1.1%-6.1% in 2008. Differences between target values and median values from the commonly used methods ranged from -0.24% to 0.22% Hb A(1c) in 2008. In 2005 83% of laboratories passed the survey, and in 2008 93% passed. At 7.0% Hb A(1c), measurement uncertainty was on average 0.49% Hb A(1c).
CONCLUSIONS: The use of accuracy-based proficiency testing with stringent quality criteria has improved the performance of Hb A(1c) testing in the Asian and Pacific laboratories during the 4 years of assessment.

Matched MeSH terms: Clinical Chemistry Tests/standards*
A short review of activated carbon assisted electrosorption process: an overview, current stage and future prospects

Foo KY, Hameed BH

J Hazard Mater, 2009 Oct 30;170(2-3):552-9.
PMID: 19501461 DOI: 10.1016/j.jhazmat.2009.05.057

Stepping into the new globalizes and paradigm shifted era, a huge revolution has been undergone by the electrochemical industry. From a humble candidate of the superconductor resources, today electrosorption has demonstrated its wide variety of usefulness, almost in every part of the environmental conservation. With the renaissance of activated carbon (AC), there has been a steadily growing interest in this research field. The paper presents a state of art review of electrosorption technology, its background studies, fundamental chemistry and working principles. Moreover, recent development of the activated carbon assisted electrosorption process, its major challenges together with the future expectation are summarized and discussed. Conclusively, the expanding of electrosorption in the field of adsorption science represents a potentially viable and powerful tool, leading to the superior improvement of pollution control and environmental preservation.

Matched MeSH terms: Charcoal/chemistry*; Electrochemistry*
Fulltext Global standardisation of HbA1c

Lai LC

Malays J Pathol, 2008 Dec;30(2):67-71.
PMID: 19291914 MyJurnal

HbA1c is used for assessing glycaemic control in patients with diabetes. It is also used for treatment goals and as a target for therapeutic intervention. The Direct Control and Complications Trial in the USA showed that HbA1c can be used to predict the risk of complications. Hence, it is important for HbA1c assays to be standardised. The National Glycohemoglobin Standardization Program (NGSP) in the USA was formed in 1996 so that HbA1c results from different laboratories would be comparable to those reported in the DCCT study. There were also HbA1c standardisation programmes in Sweden and Japan. These three standardisation programmes are, in fact, direct comparison methods (DCMs), and yield different HbA1c results. In 1994, the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) established a Working Group on Standardisation of HbA1c. This working group has developed a global HbA1c reference system with very much improved intra-assay and inter-assay coefficients of variation. Recommendations have been made to report HbA1c results as IFCC-HbA1c values in SI units (mmol HbA1c/mol Hb) and NGSP-HbA1c (%) as well as estimated average glucose (eAG), once a tight relationship has been shown to exist between eAG and HbA1c.

Matched MeSH terms: Chemistry, Clinical/standards*
Investigation on the effect of EDFA location in ring cavity Brillouin-Erbium fiber laser

Hambali NA, Mahdi MA, Al-Mansoori MH, Abas AF, Saripan MI

Opt Express, 2009 Jul 06;17(14):11768-75.
PMID: 19582091

We have investigated the characteristics of Brillouin-Erbium fiber laser (BEFL) with variation of Erbium-doped fiber amplifier (EDFA) locations in a ring cavity configuration. Three possible locations of the EDFA in the laser cavity have been studied. The experimental results show that the location of EDFA plays vital role in determining the output power and the tuning range. Besides the Erbium gain, Brillouin gain also contributes to the performance of the BEFL. By placing the EDFA next to the Brillouin gain medium (dispersion compensating fiber), the Brillouin pump signal is amplified thereby generating higher intensities of Brillouin Stokes line. This efficient process suppresses the free running self-lasing cavity modes from oscillating in cavity as a result of higher Stokes laser power and thus provide a wider tuning range. At the injected Brillouin pump power of 1.6 mW and the maximum 1480 nm pump power of 135 mW, the maximum Stokes laser power of 25.1 mW was measured and a tuning range of 50 nm without any self-lasing cavity modes was obtained.

Matched MeSH terms: Erbium/chemistry*
An overview of landfill leachate treatment via activated carbon adsorption process

Foo KY, Hameed BH

J Hazard Mater, 2009 Nov 15;171(1-3):54-60.
PMID: 19577363 DOI: 10.1016/j.jhazmat.2009.06.038

Water scarcity and pollution rank equal to climate change as the most urgent environmental issue for the 21st century. To date, the percolation landfill leachate into the groundwater tables and aquifer systems which poses a potential risk and potential hazards towards the public health and ecosystems, remains an aesthetic concern and consideration abroad the nations. Arising from the steep enrichment of globalization and metropolitan growth, numerous mitigating approaches and imperative technologies have currently drastically been addressed and confronted. Confirming the assertion, this paper presents a state of art review of leachate treatment technologies, its fundamental background studies, and environmental implications. Moreover, the key advance of activated carbons adsorption, its major challenges together with the future expectation are summarized and discussed. Conclusively, the expanding of activated carbons adsorption represents a potentially viable and powerful tool, leading to the superior improvement of environmental conservation.

Matched MeSH terms: Carbon/chemistry*
Enhanced toluene removal using granular activated carbon and a yeast strain Candida tropicalis in bubble-column bioreactors

Ahmed Z, Hwang SJ, Shin SK, Song J

J Hazard Mater, 2010 Apr 15;176(1-3):849-55.
PMID: 20031312 DOI: 10.1016/j.jhazmat.2009.11.114

The yeast strain Candida tropicalis was used for the biodegradation of gaseous toluene. Toluene was effectively treated by a liquid culture of C. tropicalis in a bubble-column bioreactor, and the toluene removal efficiency increased with decreasing gas flow rate. However, toluene mass transfer from the gas-to-liquid phase was a major limitation for the uptake of toluene by C. tropicalis. The toluene removal efficiency was enhanced when granular activated carbon (GAC) was added as a fluidized material. The GAC fluidized bioreactor demonstrated toluene removal efficiencies ranging from 50 to 82% when the inlet toluene loading was varied between 13.1 and 26.9 g/m(3)/h. The yield value of C. tropicalis ranged from 0.11 to 0.21 g-biomass/g-toluene, which was substantially lower than yield values for bacteria reported in the literature. The maximum elimination capacity determined in the GAC fluidized bioreactor was 172 g/m(3)/h at a toluene loading of 291 g/m(3)/h. Transient loading experiments revealed that approximately 50% of the toluene introduced was initially adsorbed onto the GAC during an increased loading period, and then slowly desorbed and became available to the yeast culture. Hence, the fluidized GAC mediated in improving the gas-to-liquid mass transfer of toluene, resulting in a high toluene removal capacity. Consequently, the GAC bubble-column bioreactor using the culture of C. tropicalis can be successfully applied for the removal of gaseous toluene.

Matched MeSH terms: Charcoal/chemistry
Hollow fiber gas-liquid membrane contactors for acid gas capture: a review

Mansourizadeh A, Ismail AF

J Hazard Mater, 2009 Nov 15;171(1-3):38-53.
PMID: 19616376 DOI: 10.1016/j.jhazmat.2009.06.026

Membrane contactors using microporous membranes for acid gas removal have been extensively reviewed and discussed. The microporous membrane acts as a fixed interface between the gas and the liquid phase without dispersing one phase into another that offers a flexible modular and energy efficient device. The gas absorption process can offer a high selectivity and a high driving force for transport even at low concentrations. Using hollow fiber gas-liquid membrane contactors is a promising alternative to conventional gas absorption systems for acid gas capture from gas streams. Important aspects of membrane contactor as an efficient energy devise for acid gas removal including liquid absorbents, membrane characteristics, combination of membrane and absorbent, mass transfer, membrane modules, model development, advantages and disadvantages were critically discussed. In addition, current status and future potential in research and development of gas-liquid membrane contactors for acid gas removal were also briefly discussed.

Matched MeSH terms: Acids/chemistry*
[Over one hundred year sedimentary record of polycyclic aromatic hydrocarbons in the Andaman Sea, Malaysia]

Wu YL, Wang XH, Li YY, Hong HS, Li HY, Yin MD

Huan Jing Ke Xue, 2009 Sep 15;30(9):2512-9.
PMID: 19927796

Polycyclic aromatic hydrocarbons (PAHs) in a sediment core collected from Langkawi Island of the Andaman Sea, Malaysia were determined by GC/MS, the vertical variations of concentration and distributions of PAHs were investigated. In combining with 210Pb-dating, the PAHs sedimentary record in the last 100 years was reconstructed and their possible sources were also discussed. The sigmaPAH concentration ranged from 13.2-60.1 ng x g(-1) in the whole sedimentary section (0-56 cm) with the dominant compounds of phenanthrene, naphthalene and perylene. The sediments contaminated to a lesser extent comparing with the surrounding waters. Before the 1920s, the concentrations of PAHs were considered to be the background level, which was implied from the natural inputs. The historical records of PAHs in the core showed that two distinct peaks which represented the input time of 1960s and 1980s, respectively, inferred that there were some relatively dramatically land-based inputs, and human activities leaded a clear impact to these waters during these periods. Furthermore, PAHs diagnostic ratios indicated that PAHs in the core sediments were mainly of pyrolytic origin (combustion), accompanied with minor petroleum origin. These were related with agriculture, industry, ocean import and export, and shipping activities in the surrounding regions. Meanwhile as the vital communication line, the marine transportation of the Strait of Malacca had influenced the environmental quality of the Andaman Sea. Meanwhile, based on the sedimentary record, PAHs concentrations were found to correlate positively with humanism activities and socioeconomic development (Gross Domestic Production) in the surrounding regions.

Matched MeSH terms: Geologic Sediments/chemistry*
Effects of washing pre-treatment on mercury concentration in fish tissue

Hajeb P, Jinap S

Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2009 Oct;26(10):1354-61.
PMID: 19690999 DOI: 10.1080/02652030903150567

The objective of this study was to examine the effect of washing pre-treatment on mercury concentration in fish fillet. Response surface methodology was used to investigate the influence of three variables, pH (1-6.5), NaCl (0-1% w/v) and exposure time (5-30 min) by using a three-factor central composite design. The aim was to obtain the best possible combination of these variables in order to reduce mercury in fish fillet. The experimental data were adequately fitted into a second-order polynomial model with multiple regression coefficients (R(2)) of 0.961. The results indicated that the reduction of mercury in fish flesh significantly depends on the pH of the solution used. The overall optimal condition resulting in the maximum mercury reduction in fish fillet was obtained at a combined level pH of 2.79, NaCl of 0.5% and exposure time of 13.5 min. The optimized protocol produced a solution that can reduce mercury from raw fish fillet up to 81%.

Matched MeSH terms: Mercury/chemistry*
Simultaneous enantioseparation of cyproconazole, bromuconazole, and diniconazole enantiomers by CD-modified MEKC

Wan Ibrahim WA, Warno SA, Aboul-Enein HY, Hermawan D, Sanagi MM

Electrophoresis, 2009 Jun;30(11):1976-82.
PMID: 19517438 DOI: 10.1002/elps.200800499

An efficient method for the simultaneous enantioseparation of cyproconazole, bromuconazole, and diniconazole enantiomers was developed by CD-modified MEKC using a dual mixture of neutral CDs as chiral selector. Three neutral CDs namely hydroxypropyl-beta-CD, hydroxypropyl-gamma-CD, and gamma-CD were tested as chiral selectors at different concentrations ranging from 10, 20, 30 and 40 mM, but enantiomers of the studied fungicides were not completely separated. The best dual chiral recognition mode for the simultaneous separation of cyproconazole, bromuconazole, and diniconazole enantiomers was achieved with a mixture of 27 mM hydroxypropyl-beta-CD and 3 mM hydroxypropyl-gamma-CD in 25 mM phosphate buffer (pH 3.0) containing 40 mM SDS to which methanol-acetonitrile (10%:5% v/v) was added as organic modifiers. The best separation was based on the appearance of 10 peaks simultaneously, with good resolution (R(s) 1.1-15.9), and peak efficiency (N>200,000). Good repeatabilities in the migration time, peak area, and peak height were obtained in terms of RSD ranging from (0.72 to 1.06)%, (0.39 to 3.49)%, and (1.90 to 4.84)%, respectively.

Matched MeSH terms: Cyclodextrins/chemistry*
Simplified ASE correction algorithm for variable gain-flattened erbium-doped fiber amplifier

Mahdi MA, Sheih SJ, Adikan FR

Opt Express, 2009 Jun 08;17(12):10069-75.
PMID: 19506658

We demonstrate a simplified algorithm to manifest the contribution of amplified spontaneous emission in variable gain-flattened Erbium-doped fiber amplifier (EDFA). The detected signal power at the input and output ports of EDFA comprises of both signal and noise. The generated amplified spontaneous emission from EDFA cannot be differentiated by photodetector which leads to underestimation of the targeted gain value. This gain penalty must be taken into consideration in order to obtain the accurate gain level. By taking the average gain penalty within the dynamic gain range, the targeted output power is set higher than the desired level. Thus, the errors are significantly reduced to less than 0.15 dB from 15 dB to 30 dB desired gain values.

Matched MeSH terms: Erbium/chemistry*

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