Judul: Mempelajari pengaruh ekstrak rimpang jahe (Zingiber officinale roscoe) segar dan bertunas terhadap aktifitas sel natural killer manusia dalam melisis alur sel leukemia (K-562)
Abstrak: Penyakit kanker saat ini masih menjadi urutan kedua penyebab kematian tertinggi di dunia. Untuk itu berbagai upaya perlu dilakukan untuk mengurangi resiko kanker dengan mencari bahan anti kanker yang bersifat efektif dan aman. Alternatif bahan anti kanker tersebut dapat digali dari rempah-rempah yang selama ini telah banyak dimanfaatkan sebagai obat tradisional. Rimpang jahe telah dikenal sebagai obat tradisional untuk mengatasi influenza, reumatik, batuk, anti inflamasi dan lain-lain. Hal ini diduga berkaitan erat dengan kemampuan jahe dalam menstimulir respon imun. Efek stimulasinya dapat diuji dengan melihat pengaruh ekstrak jahe terhadap aktifitas sitolitik sel Natural Killer (NK) terhadap sel kanker. Pengujiannya ditentukan berdasarkan kemampuan sel NK sebagai sel efektor, dalam melisis sel kanker (K-562) yang merupakan sel target, pada medium kultur yang ditambahkan dengan ekstrak jahe. Ekstrak jahe yang diujikan adalah jahe segar dalam air (JSA), jahe bertunas dalain air (JBA), JSA berisi komponen di bawah 8.000 dalton (JSA<8 kD), JBA berisi komponen di bawah 8.000 dalton (JBA<8 kD), jahe segar dalam etanol (JSE) dan jahe bertunas dalam etanol (JBE)
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Judul: Aktivitas antimikroba ekstrak jahe (Zingiber officinale Roscoe) terhadap beberapa bakteri patogen
Abstrak: hazards to the human health. Ginger (Zingiber officinale Roscoe) is commonly used as traditional medicine. It has a potential as antimicrobial agent by inhibit or kill microbes in dose dependent manner. The principle compounds of ginger are essential oils and non volatile compounds which maximum have antimicrobial activity. The objectives of this research are: (1) to study the yield of ginger extracts by multistage maceration with different polarity solvents, (2) to study antimicrobial activity of hexane, ethyl acetate and ethanol extract of ginger against foodborne pathogen such as Staphylococcus aureus, Bacillus cereus and Salmonella enterica serovar Typhimurium. Ginger extracts were prepared by multistage maceration method using solvent hexane, ethyl acetate and ethanol. The ginger extracts were assayed for antimicrobial activity by agar well diffusion method with Diameter Inhibition Zone (DIZ) and dillution broth method. The yield of hexane, ethyl acetate and ethanol ginger extracts from multistage maceration were respectively 3,57; 3,17; 3,02 g/100 g dry ginger. The DIZ value for Staphylococcus aureus were 5,0; 5,7; 1,3 mm with hexane, ethyl acetate and ethanol ginger extracts respectively 6,1; 6,6; 6,0 mm for Bacillus cereus and Salmonella Typhimurium were show no inhibitory zone. This results showed that the ginger extracts from multistage maceration have a weak antimicrobial activity (1,3 – 6,6 mm) against Gram-positive bacterial. The inhibition activity was determined for ethyl acetate ginger extract that showed the relatively highest inhibition zone. The minimum inhibition concentration did not reach in a range concentration between 5 – 20 mg/ml against Staphylococcus aureus and Bacillus cereus, therefore ginger extracts from multistage maceration with rotavapor temperature 50 o C and freeze dry process were not efficient to developed as natural antimicrobial.
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Judul: : Persamaan Tunggal sebagai Representasi Kurva Komposit
Abstrak: A mathematical method is introduced to represent a composite curve based on an extension of analytic geometry. The representation is given either with a single equation or with two equations, in the case of parametric representation. This method permits the representation of composite curves in similar manner to the conventional representation of non-composite curves. Some mathematical tools, including Heaviside unit step function and periodizer function, are used in the establishment of a single equation. In this paper, regular equations of regular and irregular polygon, as well as composite curves of two dimensions, are implemented using a computer algebraic system, Mathematica.
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