Judul: Aktivitas Antioksidan Ekstrak Etanol Biji Mahoni (Swietenia mahagoni Jacq.) pada jaringan Hati dan Ginjal Tikus Model Diabetes: Studi Imunohistokimia
Abstrak: Diabetes mellitus (DM) is a syndrome metabolic disease that can be indicated with high of blood glucose levels. The decreasing of carbohydrate metabolism, protein, and lipid in DM caused by deficiency and resistance of insulin. The DM condition has increased production of free radical and reactive oxygen spesies (ROS) that create a situation of known as oxidative stress, which antioxidant is lower than the amount of free radicals. As an alternative to handle oxidative stress condition, the patients of DM can consume high antioxidant plant to prevent the complication of the disease due to diabetes and to help lower of blood sugar. Any one of plant which has the antioxidant is the mahogany seeds (Swietenia mahagoni Jacq.). The mahogany seeds were conducted from the Leuwiliang, Bogor Districts, West Java. The aim of this research were to: (1) analyze the antioxidant activity of an ethanol mahogany seeds extract, (2) measure the amount of feed consumption, body weight, and blood glucose levels of diabetic rats, (3) measure of malondialdehyde levels (MDA) of the liver and kidney tissues of diabetic rats, and (4) analyze the content of antioxidant Cu,Zn-SOD of the liver and kidney tissues of diabetic rats using immunohistochemical technique. The study was used male Rattus norvegicus strain Sprague Dawley. The rats were divided into 5 groups: (i) negative control group/ non DM (K-), (ii) positive control group/ DM (K+), (iii) DM group was treated with 500 mg/kgBW of the ethanol mahogany seeds extract (EM), (iv) DM group was treated with 2 mg/kgBW of acarbose (KO), and (v) non DM group was treated with 500 mg/kgBW of the ethanol mahogany seeds extract (KE). The condition of DM was obtained by alloxan (110 mg/kgBW) induction that injected by intraperitoneal. The the measurement of blood glucose levels was used glucometer two days after alloxan induced. The blood has taken with piercing the tip of tail rats using a frank needle. Furthermore, each group has given extract treatment once a day in the morning for 28 days. The treatment has given using sonde needle. The extracts was used an ethanol mahogany seed extract macerated with 96% ethanol solvent. The weight of feed consumption was conducted every day, while the measurement of blood glucose levels and body weight of rats was conducted every four days. The weight of feed number, body weight and measurement of blood glucose levels should be done every morning before the provision of extract treatment. At the end of the treatment, the rats were anesthetized with ketamine (75 mg/kgBW) and xylazine (8 mg/kgBW). The liver and kidney tissues were conducted and analyzed for (a) the content of malondialdehyde (MDA) using thiobarbiturate acid reactive substance (TBARS) method and (b) the content of antioxidant Cu,Zn-SOD using immunohistochemical technique. The results showed that an ethanol mahogany seeds extract that macerated with 96% ethanol solvent have a weak in antioxidant activity. The DM rats that has given an ethanol mahogany seeds extract (EM) have the similiar number of feeds consumption (P>0.05) with K- group. This condition was followed by the increasing of body weight on the EM group
Keyword: diabetic experimental rats, malondialdehyde, superoxide dismutase, Swietenia mahagoni Jacq

Judul: Pengaruh Pemberian Ekstrak Etanol Biji Mahoni (Swietenia mahagoni Jacq.) Terhadap Profil Sel β Pankreas pada Tikus Diabetes Mellitus.
Abstrak: The aim of this research was to analyze the effect of ethanol mahogany seeds extract on body weight, total feed consumtion, blood glucose level, the number of beta cells and the islets of Langerhans in the pancreatic tissue of diabetic rats.This study used 25 male rats (Sprague Dawley). The rats were divided into 5 groups: (i) negative control group (K-), (ii) positive control group/diabetes mellitus (DM) (K+), (iii) DM group that was treated with 500 mg/kgBW of the ethanol mahagony seeds extract (EM), (iv) DM group that was treated with acarbose (KO), and (v) non DM group that was treated with 500 mg/kgBW of the ethanol mahagony seed extract (KE). DM condition was obtained by alloxan induction (110 mg/kgBW). The treatments were done for 28 days. Body weight, total feed intake, and blood glucose level were measured during the treatments. At the end of treatments, the pancreas tissues were then obtained and analyzed for the number of beta cells. This study showed that ethanol Swietenia mahagony seeds extract increased body weight, decrease blood glucose level and inhibit the rate of pancreatic β cells damage in the experimental diabetic rats.
Keyword: Mahogany seed extract, diabetes mellitus, beta cells, islets of Langerhans, rats

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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