Judul: Korelasi Kadar Seskuiterpena dengan Mutu Gaharu Standar Nasional Indonesia
Abstrak: Sesquiterpene content of agarwoods (Aquilaria malaccensis) of 3 different commercial grades, namely kemedangan, super tanggung A and, super A, representing low to high grades, has been identified. However, parameters designated in Indonesia National Standard (SNI) are merely qualitative, based on some physical properties of this commodity. The purpose of this study was to obtain quantitative chemical parameters in order to complement the existing parameters of SNI. In the identification step, agarwood samples were extracted using 2 different solvents, i.e. ethyl acetate and acetone. Gas chromatography-mass spectrophotometer analyses indicated that sesquiterpenes were present in all agarwood grades. Resin contents in acetone extract for kemedangan, super tanggung A, and super A were 8.5%, 13.3%, and 19.9%, respectively. Sesquiterpene content of acetone extract for kemedangan, super tanggung A, and super A were 6.1%, 7.1%, and 11.9%, respectively, and for ethyl acetate extract were 5.4%, 9.6%, and 13.4%. Resin and sesquiterpene content in acetone extracts consistently increased corresponding to the quality of commercial gaharu. A marker compound obtained in all the quality of agarwoods and agarwood extract was aromadendrene. Aromadendrene content in acetone extract from the lowest to the highest grades of commercial agarwoods were 1.2%, 1.6%, and 2.2%, respectively.
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Judul: Identifikasi komponen kimia empat tingkat mutu gaharu
Abstrak: Agarwoods (Aquilaria malaccensis) with 4 different commercial grades has been identified, namely kacangan B, teri B, medang A, and medang B, from the highest to the lowest grade. In this work, resin content tends to increase as the grade increases. However, the resin content does not have correlation with the content of sesquiterpene and chromone which determine the grade of agarwoods. In isolation step, the agarwood samples were fractionated using gradient column chromatography method with hexaneethyl acetate as eluent and were grouped according to its Rf point. Identification of samples using gas chromatography-mass spectrophotometer showed the presence of 10 sesquiterpenes and 3 chromones in various levels.
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Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model