Gelatins extracted from two edible insects Aspongubus viduatus （melon bug） and Agonoscelis pubescens （sorghum bug） were studied. The two insects showed 27.0 and 28.2% crude protein, respectively. Extraction of gel...Gelatins extracted from two edible insects Aspongubus viduatus （melon bug） and Agonoscelis pubescens （sorghum bug） were studied. The two insects showed 27.0 and 28.2% crude protein, respectively. Extraction of gelatin using hot water gave high yield followed by mild acid and distilled water extraction, respectively. SDS-PAGE pattern showed low molecular weight chains, and the two gelatins contained protein with molecular weight of 40 kDa as main component. The differential scanning calorimetry thermograms results confirm no difference between extraction methods concerning the extracted gelatin quality. FTIR spectra of melon and sorghum bug gelatins were similar and the absorption bands were situated in more than 6 bands in melon bug gelatin and only 6 bands in sorghum bug gelatin. Amide II bands of gelatins from both melon and sorghum bug appeared at around 1554 cm^-1, while Amide I bands （1734-1632 cmt） appeared only in melon bug method 2 （MB2） and melon bug method3 （MB3）. Microstructures of the insect gelatin examined with the scanning electron microscope showed that melon bug exhibited the finest gelatin network with very small voids. Melon bug gelatin showed finer structure with smaller protein strands and voids than sorghum bug gelatin.展开更多
A sensitive and specific high performance liquid chromatography （HPLC） method was developed and validated for the simultaneous determination of metformin hydrochloride （HCI） in human plasma. The HPLC method consis...A sensitive and specific high performance liquid chromatography （HPLC） method was developed and validated for the simultaneous determination of metformin hydrochloride （HCI） in human plasma. The HPLC method consists of isocratic eluation with a mixture of 60% buffer （10 mM sodium dihyrogenphosphate-10 mM sodium dodecyl sulphate） and 40% acetonitrile with final pH 7.0 with flow rate of 1.0 mL/min on a Kromasil~ Akzo Nobel RP-18 （4.6 mm ID ~ 250 mm, 5 ~tm） column at an ambient temperature. Photo diode array detection was performed in program mode at 234 rim. The analyte and diazepam as internal standard （IS） were extracted from plasma using 10% trichloroacetic acid. The assay was linear over the therapeutic concentration range of 20-2,500 ng/mL for metformin HCI with correlation coefficient of r = 0.9999. Limit of quantitation was 20 ng/mL. The results obtained for intraJinter day accuracy and precision complied very well with the generally accepted criteria for bio-analytical assay. The method was applied to bioequivalence （BE） study of metformin HCI in healthy Indonesian volunteers after treatment with 750 mg XR metformin HCI. This BE study shows that the two formulations are equivalent so that they were therapeutically interchangeable for each other.展开更多
The inability of the gas rate to overcome the gas critical(minimum)flow rate leads to liquid loading in a gas well.To avoid premature well shut-in,the injection of surfactants is one of the standard methods used in ga...The inability of the gas rate to overcome the gas critical(minimum)flow rate leads to liquid loading in a gas well.To avoid premature well shut-in,the injection of surfactants is one of the standard methods used in gas well deliquification,although many commercial surfactants pose environmental toxicity concerns.This project investigates the suitability of biosurfactants in generating foam that will reduce the surface tension of the liquid by adsorbing at the liquid-gas interface to create a more significant mass than the liquid droplets which can be easily extracted from the walls of the wellbore.An experimental setup simulating gas well conditions introduce a surfactant derived from soybean oil,subjecting it to tests for foam stability,unloading efficiency,and dynamic surface tension.The results from the modified ASTM D-892 test show that Soybean Oil Derived Surfactant(SODS)exhibits promising surface tension reduction properties and effectively alters the gas-liquid interface.With the increase in concentration from 200 ppm,400 ppm,and 600 ppm,the expelled water increased from 17%,28%,and 70%respec-tively.Similarly,Gao-Rosen adsorption isotherms confirmed SODS appropriate for the prediction of the adsorption from solution with the R 2 values of approximately 1.0.This study introduces a cost-effective and environmentally friendly surfactant that performs favorably for gas well deliquification.展开更多
文摘Gelatins extracted from two edible insects Aspongubus viduatus （melon bug） and Agonoscelis pubescens （sorghum bug） were studied. The two insects showed 27.0 and 28.2% crude protein, respectively. Extraction of gelatin using hot water gave high yield followed by mild acid and distilled water extraction, respectively. SDS-PAGE pattern showed low molecular weight chains, and the two gelatins contained protein with molecular weight of 40 kDa as main component. The differential scanning calorimetry thermograms results confirm no difference between extraction methods concerning the extracted gelatin quality. FTIR spectra of melon and sorghum bug gelatins were similar and the absorption bands were situated in more than 6 bands in melon bug gelatin and only 6 bands in sorghum bug gelatin. Amide II bands of gelatins from both melon and sorghum bug appeared at around 1554 cm^-1, while Amide I bands （1734-1632 cmt） appeared only in melon bug method 2 （MB2） and melon bug method3 （MB3）. Microstructures of the insect gelatin examined with the scanning electron microscope showed that melon bug exhibited the finest gelatin network with very small voids. Melon bug gelatin showed finer structure with smaller protein strands and voids than sorghum bug gelatin.
文摘A sensitive and specific high performance liquid chromatography （HPLC） method was developed and validated for the simultaneous determination of metformin hydrochloride （HCI） in human plasma. The HPLC method consists of isocratic eluation with a mixture of 60% buffer （10 mM sodium dihyrogenphosphate-10 mM sodium dodecyl sulphate） and 40% acetonitrile with final pH 7.0 with flow rate of 1.0 mL/min on a Kromasil~ Akzo Nobel RP-18 （4.6 mm ID ~ 250 mm, 5 ~tm） column at an ambient temperature. Photo diode array detection was performed in program mode at 234 rim. The analyte and diazepam as internal standard （IS） were extracted from plasma using 10% trichloroacetic acid. The assay was linear over the therapeutic concentration range of 20-2,500 ng/mL for metformin HCI with correlation coefficient of r = 0.9999. Limit of quantitation was 20 ng/mL. The results obtained for intraJinter day accuracy and precision complied very well with the generally accepted criteria for bio-analytical assay. The method was applied to bioequivalence （BE） study of metformin HCI in healthy Indonesian volunteers after treatment with 750 mg XR metformin HCI. This BE study shows that the two formulations are equivalent so that they were therapeutically interchangeable for each other.
文摘The inability of the gas rate to overcome the gas critical(minimum)flow rate leads to liquid loading in a gas well.To avoid premature well shut-in,the injection of surfactants is one of the standard methods used in gas well deliquification,although many commercial surfactants pose environmental toxicity concerns.This project investigates the suitability of biosurfactants in generating foam that will reduce the surface tension of the liquid by adsorbing at the liquid-gas interface to create a more significant mass than the liquid droplets which can be easily extracted from the walls of the wellbore.An experimental setup simulating gas well conditions introduce a surfactant derived from soybean oil,subjecting it to tests for foam stability,unloading efficiency,and dynamic surface tension.The results from the modified ASTM D-892 test show that Soybean Oil Derived Surfactant(SODS)exhibits promising surface tension reduction properties and effectively alters the gas-liquid interface.With the increase in concentration from 200 ppm,400 ppm,and 600 ppm,the expelled water increased from 17%,28%,and 70%respec-tively.Similarly,Gao-Rosen adsorption isotherms confirmed SODS appropriate for the prediction of the adsorption from solution with the R 2 values of approximately 1.0.This study introduces a cost-effective and environmentally friendly surfactant that performs favorably for gas well deliquification.
