Journal of Mathematical and Fundamental Sciences
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Molecular modeling on the identification of potential Janus Kinase 3 (JAK3) inhibitor based on the Indonesian Medicinal Plant Database
Get PDFThe Janus tyrosine kinases (JAKs) have shown great promise as therapeutic protein targets in the treatment of cancer and inflammation diseases. This study used pharmacophore modeling to identify potential inhibitors of Janus kinase 3 (JAK3). A pharmacophore model was developed based on a known JAK3 inhibitor (1NX) and was employed to search for potential JAK3 inhibitors against Indonesian herbal compounds. Among 28 hit molecules that were identified and subjected to a molecular docking protocol against JAK3, the three compounds that had the highest affinities toward JAK3 were camelliaside B, 3-O-galloylepicatechin-(4beta-6)-epicatechin-3-O-gallate, and mesuaferrone B. These were then each subjected to a 50-ns molecular dynamics (MD) simulation. Analysis of RMSD and RMSF values indicated that the three compounds reached stability during the MD simulation. Interestingly, all three compounds had lower binding energies than 1NX against JAK3, as predicted by the MM-PBSA binding energy calculation
Improved Variational Iteration Solutions to the SIR Model of Dengue Fever Disease for the Case of South Sulawesi
Get PDFThe susceptible-infected-recovered (SIR) model of the spread of dengue fever for the case of South Sulawesi is considered. Rangkuti's variational iteration method (RVIM) is recalled. This paper makes four contributions. The first one is to provide a successive approximation method (SAM) for solving the considered model. The second one is to show that SAM and RVIM are identical. Thirdly, a modification of RVIM is proposed. Fourthly, it is shown that the modification leads to an improvement of the accuracy of the method. Both RVIM and the improved version are quite accurate for short time periods. However, the improved version is more accurate and is able to provide more realistic explicit solutions to the model
Classification and Dynamics of Class of ξ(as)-QSO
Get PDFThe current study provides a new class of ξ(as)-QSO defined on 2D simplex and classifies it into 18 non-conjugate (isomorphic) classes. This classification is based on their conjugacy and the remuneration of coordinates. The current study also examines the limiting points associated with the behavior of trajectories for four classes defined on 2D simplex
P-properties in Near-rings
Get PDFIn this paper, assuming that N is a near-ring and P is an ideal of N, the P-center of N, the P-center of an element in N, the P-identities of N are defined. Their properties and relations are investigated. It is shown that the set of all P-identities in N is a multiplicative subsemigroup of N. Also, P-right and P-left permutable and P-medial near-rings are defined and some properties and connections are given. P-regular and P-strongly regular near-rings are studied. P-completely prime ideals are introduced and some characterizations of -completely prime near-rings are provided. Also, some properties of P-idempotents, P-centers, P-identities in P-completely prime near-rings are investigated. The results that were obtained in this study are illustrated with many examples
Direct Method Solution of 3-D Magnetotelluric Modeling Using Vector Finite Element Method
Get PDFAs exploration is forced into more difficult areas with complex three-dimensional (3-D) structural environments, the importance of 3-D magnetotelluric (MT) modeling is essential for the correct interpretation of MT data. To reduce the complexity of the calculations introduced by 3-D models, iterative forward calculation of MT response functions is used as basis for inversion of 3-D MT data. This paper proposes an alternative procedure for making reliable 3-D MT modeling codes for forward calculation that is not only effective but also accurate. This is accomplished by using a direct method to solve the linear systems arising from the discretization process in the vector finite element approach. The vector finite element method is known for its capability of overcoming difficulties in modeling caused by possible jumps of normal components across discontinuities of material properties. Meanwhile, by using a direct method rather than an iterative method, the process of solving the linear equations does not suffer from slow convergence. Here, we present a comparison between our modeling codes and codes based on a different approach. In the resulting 3-D MT responses it was found that the proposed method has high accuracy
Suatu Senyawa Stilbene Terprenilasi dari Kayu Akar Tumbuhan Artocarpus Altilis
No full textSuatu stilben terprenilasi, trans-4-(3-metil-E-but-l-enil)-3,5,2',4'-tetrahidroksistilben telah ditemukan untuk pertama kalinya dari ekstrak kloroform kayu akar tumbuhan Artocarpus altilis (Moraceae), yang dikenal dengan nama Sukun. Struktur molekul senyawa ini telah ditetapkan berdasarkan data fisika dan spektroskopi UV, IR, MS, 1H dan 13C NMR. Senyawa ini bersifat toksik (LC50 = 45,7 µg/mL) terhadap benur udang Artemia salina Leach. A prenylated stilbene from the root trunk of Artocarpus altilisA prenylated stilbene, trans-4-(3-methyl-E-but-l-enyl)-3,5,2',4'-tetrahydroxystilbene had been isolated for the first time from the chloroform extract of the root trunk of Artocarpus altilis (Moraceae), locally known as Sukun. The structure of this compound was Elucidated based on physical and spectroscopic data UV, IR, MS, 1H and 13C NMR. It showed strong toxicity (LC50 = 45,7 µg/mL) agains Atrtemia salina Leach shrimp.*Bagian ke-25 dari seri "llmu Kimia Tumbuhan Moraceae lndonesia". Untuk Bagian ke-24 lihat pustaka (5
Linear Potential Sweep Voltammetry in Conjunction with Small Amplitude Cyclic Voltammetry Study for Chalcopyrite-Xanthate Electrochemical Flotation System
Get PDFAbstract. The present study was undertaken to investigate the electrochemical aspects of reactions on platinum, copper, and chalcopyrite aqueous xanthate solution interfaces by the small amplitude cyclic voltammetry (SACV) technique. In the technique, the potential of an electrode is swept linearly with time within very narrow potential limits. Typically a 10 to 20 mV peak-to-peak triangular potential excitation has been used. Characteristic parameters of the observed current-potential response loop, like apparent polarization resistance, was used to analyze the surface reaction mechanism in the flotation of chalcopyrite minerals. The analysis of the electrochemical interaction between platinum, copper and xanthate ions has also been carried out by using linear potential sweep voltammetry (LPSV) techniques in different xanthate concentrations. The voltammograms obtained on platinum appear due to the possibility of the formation of dixanthogen from the oxidation of xanthate ions, and the formation of copper-xanthate species from elecbochemical reactions between xanthate ions and copper. Studi Voltametri Penyapuan Potensial Linier Dikaitkan dengan Voltametri Siklus Amplitudo Kecil untuk Sistem Flotasi Elektrokimia Kalkopirit-xantatSari. Penelitian ini memberikan gambaran reaksi elektrokimia pada antarmuka elektroda platina, tembaga, dan kalkopirit di dalam larutan encer xantat. Penelitian dilakukan dengan metode SACV (Small Amplitude Cyclic Voltammetry), dengan rentang eksitasi potensial segitiga yang sangat kecil, yaitu 10 mV sampai 20 mV eksitasi dipakai untuk menganalisis mekanisme reaksi flotasi mineral kolkopirit. Untuk mempertegas hasil SACV penelitian dilanjutkan dengan metode LPSV (Linear Potential Sweep Voltammetry). Voltammogram yang diperoleh menggambarkan terbentuknya dixantogen di permukaan elektroda platina, dan terbentuknya senyawa tembaga-xantat karena adanya reaksi permukaan antara ion xantat dengan tembaga
Perubahan Struktur Kristal dan Index Kerja Bijih Emas Cimanggu, Jawa Barat akibat Pemanasan Gelombang Mikro
No full textSari. Energi yang dibutuhkan pada proses kominusi dapat mencapai 50-70% dari keseluruhan energi yang digunakan pada pengolahan mineral. Karena itu, diperlukan usaha untuk menurunkan pemakaian energi kominusi dengan mengubah sifat fisik bijih agar murah hancur. Pemanasan gelombang mikro pada bijih sebelum kominusi merupakan salah satu alternatif yang dapat diterapkan. Pada penelitian ini telah diamati besarnya energi penggerusan bijih emas dari Cimanggu, Jawa Barat sebelum dan sesudah diperlakukan dengan pemanasan gelombang mikro. Hasil penelitian menunjukkan bahsa pemanasan gelombang mikro dapat mengubah struktur fisik mineral. Perubahan struktur fisik mineral pembentuk batuan menyebabkan batuan tersebut menjadi lebih getas, dan adanya "interal stress" mengakibatkan kecepatan pemanasan yang tinggi menyebabkan timbulnya retakan sehingga dapat memperpendek waktu gerus dan menurunkan energi penggerusan. Dengan pemanasan gelombang mikro selama 5, 15, 30, 60, 120 dan 300 detik sebelum pengggerusan, indeks kinerja penggerusan dapat turun sekitar 20 sampai 35%. The Influence of Microwave Heating on the Crystal Structure and Work Index of Cimanggu (West Java) Gold OreAbstract. The energy consumed in the comminution can reach up to 50- 70% of the whole energy consumed in the mineral processing. It is necessary to reduce the consumption of the comminution energy changing the physical characteristic of the ore. The microwave energy heating used on the ore before comminution is one of the applicable alternatives. In this research the grinding energy of the Cimanggu gold ore, West Java, has been observed before and after the microwave heating treatment. The result indicates that the microwave treatment can cause physical structural changes on certain minerals, and the rock become more brittle. It can shorten and reduce the grinding time and energy. By microwave energy induced for 5, 15, 30, 60, 120, and 300 seconds prior to grinding, the work index was reduced by about 20 to 35%