Judul: Karakterisasi dan aktivitas antioksidan nanopartikel ekstrak kulit kayu mahoni (Swietenia macrophylla King.) tersalut kitosan
Abstrak: Ekstrak kulit kayu mahoni (Swietenia macrophylla King.) berkhasiat sebagai antioksidan. Upaya untuk mengoptimalkan efisiensi penyerapan ekstrak kulit kayu mahoni oleh tubuh adalah dengan penyalutan menggunakan enkapsulasi. Penelitian ini bertujuan untuk membuat nanopartikel ekstrak kulit kayu mahoni, melakukan karakterisasi nanopartikel yang diperoleh, dan menentukan aktivitas antioksidan nanopartikel ekstrak kulit kayu mahoni. Pembuatan nanopartikel ekstrak kulit kayu mahoni menggunakan utrasonikator dengan variasi waktu ultrasonikasi (30 dan 60 menit). Sampel kemudian dikeringkan dengan pengering semprot. Rendemen yang diperoleh untuk nanopartikel dengan waktu ultrasonikasi 30 dan 60 menit secara berturut-turut sebesar 3.104% dan 4.149%. Ukuran nanopartikel ekstrak kulit kayu mahoni dengan waktu ultrasonikasi 30 dan 60 menit berkisar pada rentang 480-2000 nm dan 240-1000 nm. Karakterisasi FTIR menunjukkan bahwa gugus fungsi khas yang terdapat pada ekstrak kulit kayu mahoni terdeteksi pada sampel nanopartikel ekstrak kulit kayu mahoni dengan waktu ultrasonikasi 30 menit, tetapi tidak terdeteksi pada nanopartikel ekstrak kulit kayu mahoni dengan waktu ultrasonikasi 60 menit. Hasil XRD menunjukkan bahwa nanopartikel berstruktur amorf. Nilai derajat kristalinitas nanopartikel dengan waktu ultrasonikasi 30 dan 60 sebesar 46.593% dan 58.677%. Antioksidan nanopartikel ekstrak kulit kayu mahoni dengan waktu ultrasonikasi 30 dan 60 memiliki aktivitas penghambatan DPPH yang lebih rendah dibandingkan ekstrak kulit kayu mahoni.
Keyword: Nanoparticles, Mahogany, Antioxidant

Judul: Aktivitas Antioksidan dan Penghambatan α-Glukosidase Ekstrak dan Nanopartikel Ekstrak Kulit Kayu Mahoni (Swietenia macrophylla King)
Abstrak: Mahogany (Swietenia macrophylla King) bark is waste disposal industry manufacture of bark. Mahogany bark have catechin, epicatechin, and swietemacrophyllanin contents which useful as an antioxidants and antidiabetic of rats induced alloxan. This study aimed to determine the antioxidant activity and inhibition of α-glucosidase in the extract and nanoparticle extract of mahogany bark. Extraction method use aquades as solution, antioxidant activity assays was caried using 2,2-diphenyl-1-picrilhidrazyl (DPPH) and reducing power. Inhbition of α-glucosidase was measured with a spectrophotometric method. Mahogany moisture content was 4.87%. Extract yield of 9.46% and yield of nanoparticle 51.11% were obtained. The DPPH resulted that of the rutin compound, extract, and nanoparticles obtained by IC50 DPPH method sequentially 17.33 ± 1.17 ppm, 9.62 ± 0.72 ppm, and more than 2500 ppm. Respectively, power reduction of the rutin compound has a 67.03% at 25 ppm, the extract 67.41% at 20 ppm, and nanoparticle 31.47% at 20 ppm. IC50 values inhibition of α-glucosidase extract was 17.25 ppm, nanoparticles were more than 200 ppm, and acarbose was 0.37 ppm. The test results showed that the extract capable of acting as antioxidant and antidiabetic based on IC50 values. As for nanoparticles mahogany bark extract did not able to act as antioxidants and antidiabetics based on the method tested.
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Judul: Implementation of Spatio-Temporal Change Query in Relational Database.
Abstrak: Geographic object changes in various views. Object changes are recorded using a model of static storage. No historical connection between old version data and new version data has been built. For that, a storage model of spatio-temporal queries that can analyze spatio-temporal changes has been developed. The object changes the geometry are grouped according to the taxonomy of Spatio-Temporal Pattern Change. This research has been able to apply the query patterns change including born, expand, merge, contract, split, normal and die. This query based on geometric (area) changes. The implementation of spatio-temporal change queries represents an object changes continuously with easy, change detection is done by comparing two versions of data. Keyword: spatio-temporal change query, spatio-temporal change pattern.
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