Judul: The Potency of Biflavonoid Compounds in the Araucaria Genus as Anticancer Agent Using 2D-QSAR Method via 20S Proteasome Inhibition
Abstrak: Kanker adalah penyakit yang disebabkan oleh perubahan gen yang mengendalikan fungsi sel. Hingga saat ini obat kanker masih terus dikembangkan dan proteasom 20S telah diidentifikasi sebagai target obat antikanker terutama pada subunit chymotrypsin-like activities (ß5). Senyawa isoginkgetin berasal dari daun pohon Ginkgo biloba L. dan dilaporkan memiliki sifat antikanker. Untuk memprediksi senyawa terbaik, Two Dimension-Quantitative Structure-Activity Relationship (2D-QSAR) digunakan dalam penelitian ini. Saat memprediksi dibutuhkan sebuah model dengan memvalidasi memakai cross-validation dan validasi eksternal, serta melihat faktor lain seperti nilai koefisien determinasi (R2), mean square error (MSE), root mean square error (RMSE), dan mean absolute error (MAE). Model support vector machine (SVM) dipilih menjadi model terbaik. Prediksi senyawa menggunakan data biflavonoid dari genus Araucaria menunjukkan bahwa urutan senyawa terbaik dengan IC50 menurut prediksi model SVM adalah morelloflavon dan oknaflavon.
Keyword: Antikanker, biflavonoid, ic50, pemodelan, QSAR

Judul: Literature Review of the Araucariaceae Family and  Biflavonoid Compounds in Araucaria cunninghamii Leaves with Potential as  Anticancer
Abstrak: Meningkatnya penderita kanker di Indonesia juga meningkatkan kebutuhan obat. Kemoterapi dan radioterapi banyak dipilih dalam pengobatan kanker secara modern. Namun, pengobatan tersebut menimbulkan efek samping dan biaya tinggi sehingga perlu dikembangkan obat dari bahan alam yang mengandung senyawa dengan aktivitas antikanker yang baik. Salah satu senyawa tumbuhan yang memiliki aktivitas antikanker adalah biflavonoid. Biflavonoid dapat ditemukan pada famili Araucariaceae, salah satunya pada genus Araucaria. Telaah pustaka ini bertujuan menganalisis berbagai senyawa biflavonoid pada famili Araucariaceae dan memahami biogenesis maupun sintesis biflavonoid, serta menganalisis struktur biflavonoid pada daun A. cunninghamii yang memiliki potensi antikanker. Biflavonoid yang ditemukan ialah amentoflavon dan kupresuflavon, yang dapat disarankan menjadi kandidat senyawa antikanker dengan mekanismenya menghambat proliferasi sel. Kemampuannya sebagai antikanker dipengaruhi oleh jumlah dan letak substituen pada kerangka biflavonoid., The increase in cancer patients in Indonesia makes the need for drugs also increase. Chemotherapy and radiotherapy are widely chosen as modern cancer treatments. However, these treatments cause side effects and high costs, so developing drugs from natural ingredients containing compounds with good anticancer activity is necessary. One of the plant compounds that have anticancer activity is biflavonoid. Biflavonoids can be found in the family Araucariaceae, one of which is the genus Araucaria. This literature review aims to analyze various biflavonoids compounds in the Araucariaceae family, understand biflavonoid biogenesis and synthesis, and explore the structure of biflavonoids in Araucaria cunninghamii leaves, which have potential as anticancer. The biflavonoids are amentoflavones and cupresuflavones that can be suggested as anticancer candidates with their mechanism in inhibiting cell proliferation. Their abilities as anticancer agents are influenced by the number and location of substituents in the biflavonoid structure.
Keyword: antikanker, Araucariaceae, Araucaria cunninghamii, biflavonoid, anticancer, biflavonoids

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.
Keyword: