Judul: Toxicity Test of Gelatin Capsule Materials from Catfish Skin (Pangasius sp.) on Mice (Mus musculus)
Abstrak: Gelatin berasal dari kulit dan tulang hewan yang salah satu fungsi nya dapat digunakan sebagai pembentuk kapsul obat-obatan. Isu mengenai penyakit dari sapi dan perbedaan keyakinan konsumen merupakan kendala dalam mengonsumsi gelatin babi maupun sapi, sehingga membuka peluang untuk mencari alternatif gelatin dari sumber lain yaitu ikan. Penelitian ini bertujuan untuk menentukan tingkat toksisitas bahan kapsul gelatin kulit ikan patin (Pangasius sp.) dengan metode fixed dose procedure pada mencit yang dilihat dari nilai LD50. Dosis 2000 mg/kg BB ditentukan sebagai dosis awal uji utama setelah dilakukan uji pendahuluan. Hewan uji dibagi menjadi 2 kelompok yaitu kelompok kontrol dan kelompok dosis 2000 mg/kg BB yang masing-masing terdiri dari 5 ekor mencit betina galur DDY. Hasil penelitian menunjukkan nilai LD50 gelatin kulit ikan patin > 2000 mg/kg BB. Gelatin kulit ikan patin tidak bersifat toksik yang dibuktikan dengan tidak adanya kematian dan perubahan rata-rata bobot badan mencit. Organ yang dipengaruhi oleh gelatin kulit ikan patin yaitu paru-paru berdasarkan perbedaan nyata pada bobot bobot relatif., Gelatin is derived from the skin and bones of animals, which one of its functions can be used as a capsule-forming drug. Disease from cattle and differences in consumer beliefs are the obstacles in consuming pork and beef gelatin, thus opening up to new opportunity to develop gelatin from fish. This study aims to determine the level of toxicity of gelatin capsule materials from catfish skin (Pangasius sp.) using the fixed dose procedure method on mice based on the LD50 value. The dose of 2000 mg/kg BW was determined as the initial dose of the main test after the preliminary test. The test animals were divided into 2 groups, namely the control group and the 2000 mg/kg BW dose group, each consisting of 5 female DDY mice. The results showed that the LD50 value of catfish skin gelatin was > 2000 mg/kg BW. Catfish skin gelatin is non-toxic as evidenced by the absence of death and changes in the average body weight of mice. Organs that are affected by catfish skin gelatin are the lungs based on significant differences in relative weight
Keyword: ikan patin, kapsul, mencit, uji toksisitas akut, capsule, catfish, gelatin, mice, oral toxicity test

Judul: Effect of NaOH Comparison on Patin Skin Pretreatment (Pangasius hypophthalamus) on Gelatin and Its Application on Hard Capsule Shells
Abstrak: Kulit ikan patin sangat potensial menjadi sumber gelatin, namun proses pretreatment yang dilakukan belum maksimal. Penelitian ini bertujuan menentukan perbandingan NaOH dan sampel dalam proses preatreatment, serta karakteristik fisik-kimia gelatin kulit ikan patin. Metode yang dilakukan yaitu Rancangan Acak Lengkap dan uji lanjut Duncan. Karakteristik gelatin yang telah sesuai dengan standar GMIA 2019 dan SNI 8622-2018. Perlakuan terbaik didapatkan pada perlakuan perbandingan 1:8 (b/v). Perlakuan tersebut menghasilkan rendemen 22,66 ± 1,07%; pH 6,43 ± 0,14; viskositas 67,5 ± 1,50 mps; dan kekuatan gel 244,143 ± 1,69 bloom. Perlakuan tersebut diaplikasikan dalam pembuatan cangkang kapsul keras. Karakteristik cangkang kapsul keras yang dihasilkan telah sesuai dengan standar Departemen Kesehatan RI (2020). Analisis histologi menunjukkan bahwa perlakuan yang digunakan belum mampu menghancurkan lapisan stratum compactum, sehingga perlu dilakukan treatment dengan cara lain agar rendemen gelatin yang dihasilkan maksimal., Pangasius skin has the potential to be a source of gelatin, but the process of pretreatment is not optimal. The purpose of this research was to determine the ratio of NaOH and samples in the process of the pre-treatment, as well as physicochemical characteristics of gelatin from catfish skin. The method used was Completely Randomized Design and Duncan's further test. Gelatin characteristics that are in accordance with the GMIA 2019 standard and SNI 8622-2018. The best treatment was obtained at a 1:8 (w/v) comparison treatment. This treatment resulted in a yield of 22.66 ± 1.07%; pH 6.43 ± 0.14; viscosity 67.5 ± 1.50 mps; and gel strength 244.143 ± 1.69 bloom. This treatment was applied in the manufacture of hard capsule shells. The characteristics of the hard capsule shell produced meet the standards of the Indonesian Ministry of Health (2020). Histological analysis showed that the treatment used had not been able to destroy the layer stratum compactum, so it was necessary to do other treatments in order to maximize the yield of gelatin.
Keyword: catfish, gelatin, hard capsule, NaOH, pretreatment

Judul: Bifurkasi Hopf pada Model Siklus Bisnis Kaldor Kalecki tanpa dan dengan Waktu Tunda
Abstrak: Business cycle model is one of dynamical system models in economic. One of the business cycles model is Kaldor-Kalecki model. Kaldor-Kalecki business cycle model that is written in delayed defferential equations, is a business cycle model that involves gross product and capital stock of a company. In this paper Kaldor-Kalecki business cycle model is analyzed using both nondelay and delay in time of capital stock. By Taylor expansion for the time delayed model, an analysis of stability around the fixed points has been done. Furthermore, by using Hopf bifurcation theorem, it can be shown that there exists periodic orbits and limit cycle. In the nondelayed model, changing the parameter of goods market could lead to the occurrence of Hopf bifurcation and the existence of limit cycle. Similarly, for the delayed model, it has been shown that changing the time delay parameter may result in the occurrence of Hopf bifurcation and limit cycle.
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