Pengaruh Ekstrak Kulit Jeruk Nipis (Citrus Aurantifolia Swingle) Konsentrasi 10% Terhadap Aktivitas Enzim Glukosiltransferase Streptococcus Mutans

Streptococcus mutans merupakan bakteri yang berperan sebagai agen utama penyebab karies gigi, yang memiliki enzim glukosiltransferase (GTF). Enzim GTF akan mengubah sukrosa menjadi fruktosa dan glukan. Salah satu herbal tradisional yang dapat berperan sebagai antibakteri adalah kulit jeruk nipis (Citrus aurantifolia Swingle) yang mengandung polifenol terutama flavonoid. Tujuan penelitian ini untuk mengetahui pengaruh ekstrak kulit jeruk nipis (Citrus aurantifolia Swingle) konsentrasi 10% terhadap aktivitas enzim GTF Streptococcus mutans. Penelitian ini menggunakan ekstrak kulit jeruk nipis konsentrasi 10% sebagai perlakuan, chlorhexidine gluconate 0,12% sebagai kontrol positif, serta akuades steril sebagai kontrol negatif. Metode penelitian ini terdiri dari tiga tahap yaitu penyiapan ekstrak kulit jeruk nipis konsentrasi 10%, penyiapan enzim GTF dari supernatan Streptococcus mutans, dan pengujian aktivitas enzim GTF melalui analisis konsentrasi fruktosa dengan menggunakan High Performance Liquid Chromatography (HPLC). Pembacaan luas area fruktosa dilakukan berdasarkan waktu retensi. Satu unit aktivitas enzim GTF di definisikan sebagai 1 µmol fruktosa/ml dari enzim/jam. Selanjutnya data yang diperoleh dianalisis secara statistik dengan one way ANOVA.Hasil perhitungan aktivitas enzim GTF dengan one way ANOVA menunjukkan perbedaan yang signifikan antara kelompok perlakuan dengan kelompok kontrol negatif (p<0,05), dan tidak terdapat perbedaan yang signifikan dengan kontrol positif. Kesimpulan dari penelitian ini adalah ekstrak kulit jeruk nipis konsentrasi 10% dapat menghambat aktivitas enzim glukosiltransferase Streptococcus mutans. The Influence of 10% Concentrate of Citrus Aurantifolia Swingle on The Activities of Streptococcus Mutans Glucocyl Transferase Enzyme. Streptococcus mutans is a bacteria which has glucosyl transferase (GTF) enzyme and acts as the main agent that causes dental caries. GTF enzyme will convert sucrose into fructose and glucan. Lime peel (Citrus aurantifolia Swingle) is one of the traditional herbs which has flavonoid as an antibacterial agent. The purpose of this research is to investigate the effect of 10% concentration of lime peel extract (Citrus aurantifolia Swingle) to the activity of GTF enzyme Streptococcus mutans.This research used 10% concentration of lime peel extract as the treatment, 0.12% chlorhexidine gluconate as a positive control, and distillate water as anegative control. The method of this research consists of three steps; preparing the lime peel extract concentration of 10%, preparing the GTF enzyme from the supernatant of Streptococcus mutans, and testing GTF enzyme activity by analyzing the fructose concentration using High Performance Liquid Chromatography (HPLC). Perusal of the fructose area was based on the retention time of fructose. One unit of GTF enzyme activity is defined as the 1 μmol fructose / ml of enzyme / hour. The obtained data then were analyzed by one way ANOVA. The result showed a significant difference between treatment group with the negative control (p <0.05), and there are no significant difference with the positive control. This research concludes that 10% lime peel extract can inhibit the GTF enzyme activity of Streptococcus mutans

Model of Land Cover Change Caused by Toll Road Access Using Cellular Automata in Sumatra Island

The use of land is a part of the fulfillment of human needs. The establishment of a large-scale infrastructure project often triggers an increase in land cover around its infrastructure project. Most of the increase in built up land tends to occur in areas that are traversed by or located near main accessibility routes such as toll roads. Although the construction of toll roads can improve accessibility between regions, land is a limited resource. So that it becomes the basis for researchers to identify the changes in land use in regencies and cities on the island of Sumatra that are crossed by toll roads that have been operating. The goal of land use change analysis is to give a description or explanation, predict, look at the effects, and make a decision (prescription). This research was conducted by identifying the changes in the existing land cover and predicting the land cover using cellular automata. Cellular automata have proven to be a method that is suitable for predicting the dynamics of land use through spatial simulation. The results show that there was an increase in the amount of land built from early 2017 to 2030. The covered land is developed around the toll gate after it is actively operated. In all provinces studied, deviation discrepancies were found in the conservation and cultivation areas. Deviations that occur in conservation areas need to be considered as there should be no land built in these areas, which means that there are cultivation activities in the conservation areas

Surface symmetry-breaking and strain effects on orbital occupancy in transition metal perovskite epitaxial films

The electron occupancy of 3d-orbitals determines the properties of transition metal oxides. This can be achieved, for example, through thin-film heterostructure engineering of ABO(3) oxides, enabling emerging properties at interfaces. Interestingly, epitaxial strain may break the degeneracy of 3d-e(g) and t(2g) orbitals, thus favoring a particular orbital filling with consequences for functional properties. Here we disclose the effects of symmetry breaking at free surfaces of ABO(3) perovskite epitaxial films and show that it can be combined with substrate-induced epitaxial strain to tailor at will the electron occupancy of in-plane and out-of-plane surface electronic orbitals. We use X-ray linear dichroism to monitor the relative contributions of surface, strain and atomic terminations to the occupancy of 3z(2)-r(2) and x(2)-y(2) orbitals in La(2/3)Sr(1/3)MnO(3) films. These findings open the possibility of an active tuning of surface electronic and magnetic properties as well as chemical properties (catalytic reactivity, wettability and so on)