Judul: Potensi Antioksidan Ekstrak Nanopartikel Kulit Kayu Mahoni Pada Tikus Dengan Prakondisi Diet Kaya Lipid
Abstrak: The aim of this research is to explore the antioxidant potency of nanoparticles of mahogany bark extracts in vivo. Thirty five rats were divided into three groups: normal rats (5), nanoparticle extracts- and crude extracts-treated rats (15 rats for each groups). Nanoparticle extracts- and crude extratcs- treated rats were preconditioned with high-lipid diet for 12 weeks. The research period was extended for 15 weeks hence the rats were all old animals (41 weeks old). Crude extracts and nanoparticles extracts groups were gavaged orally with dose of 300 mg/Kg BW. Lipid peroxide of blood serum was analyzed with thiobarbituric acid method (TBA) using spectrophotometer at 553 nm. Antioxidant potency of nanoparticles extracts of mahogany’s bark is showed by 44% reduction of rat’s blood lipid peroxide whereas the crude extracts only reduce 35%.
Keyword: nanoparticles, mahogany bark, antioxidant

Judul: Khasiat antioksidasi ekstrak kulit kayu mahoni (Swietenia macrophylla King) terhadap peroksidasi lipid pada hati tikus hiperurisemia
Abstrak: The bark of mahogany (Swietenia macrophylla King) contains bioactive compounds, which has been reported as an antioxidant. But there had been very few in vivo evidence of the antioxidant effectiveness on the liver lipid peroxidation in hyperuricemic rats. This study aimed to test the effect of mahogany (Swietenia macrophylla King) bark extracts against lipid peroxidation in hyperuricemic rat liver. Thirty three rats were divided into 5 groups, namely normal, hyperuricemic (HU), allopurinol (HU I), aqueous extract (HU II) and methanol extract (HU III). Hyperuricemic induction was carried out by giving the juices of chicken liver and sodium carboxyl methyl cellulose 0.5%. The induction was administered orally for 4 weeks with dosage of 25 g/kg BW. Afterwards, rat were administered by aqueous extract and methanol extract at 500 mg/Kg BW day for 7 days. Liver lipid peroxides analysis was determined by using thiobarbituric acid (TBA) method. The results showed that the lipid peroxide concentrations of hyperuriemic, allopurinol and methanol extracts group were 101.51 ± 54.74 nmol/gram, 108.55 ± 45, nmol/g and 101.04 ± 26.68 nmol/gram, respectively. The aqueous extract has the antioxidants effect on rat liver lipid peroxidation with the concentration of 63.57 ± 16.84 nmol/g, smaller than that of the normal group (93.83 ± 29.55 nmol/gram). Statistically, the aqueous extract tend to decrease the liver lipid peroxide concentration of hiperuricemic rat by 32.25% (p = 0.054).
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Judul: Gelombang soliter internal pada lapisan atmosfiri yang memiliki perubahan kecepatan angin yang cepat
Abstrak: Gelombang internal adalah suatu gelombang yang terjadi di dalam suatu fluida. Gelombang ini muncul karena adanya perubahan rapat massa di setiap lapisan di dalam fluida. Salah satu gelombang internal yang ditemui di lappisan atmosfir adalah gelombang soliter internal, seperti yang terjadi pada fenomena "morning glory" di Australia. pada fenomena "Morning glory" terjadi penurunan tekanan hingga bebrapa milibar.
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