Judul: Potensi Buah Makasar (Brucea javanica (L.) Merr) sebagai Inhibitor Enzim α-Glukosidae
Abstrak: Brucea fruit is one Indonesian medicine plants which rich in advantages. Empirically, brucea fruit can decrease blood glucose concentration for patient of diabetes mellitus. Water fraction of brucea fruit extract have been observed to determine its ability as antidiabetic would be compared with acarbose as positive control in same concentration (1%). Antidiabetic test in water and hexane fraction of brucea fruit extract use α-glucosidase inhibition method. Antidiabetic activity has been measured by formation of p-nitrophenol from enzymatic reaction of nitrophenil--D-glucopyranose (p-NPG) which is catalyze by α-glucosidase enzyme. The formation of p-nitrophenol was measured by spectrophotometer at λ=400 nm. Phytochemistry test showed that water fraction contains alkaloid and flavonoid, whereas hexane fraction only contain alkaloid. The result of this research is water fraction and hexane of brucea fruit (Brucea javanica (L.) Merr) at concentration 1% (b/v) can inhibit α-glucosidase enzyme activity 14.32% and 12.76%, whereas Acarbose as positive control can inhibit α-glucosidase enzyme activity 81.15%.
Keyword: 

Judul: Aktivitas Fraksi Kloroform Buah Makasar (Brucea javanica [L.] Merr.) sebagai Inhibitor Enzim α-Glukosidase
Abstrak: Brucea fruit (Brucea javanica (L.) Merr) is a plant used in traditional medicine and proven pre-clinically for antimalaria, antipyretic, anticancer and homeostatic effects. However, the antidiabetic mechanism of this plant has not been elucidated. This research was done to determine the potential of chloroform fraction of brucea fruit at 1, 1.5, 2% as α-glucosidase inhibitor and compared their activities with acarbose 1% as a positive control. Brucea fruits were extracted with ethanol solution of 95% using maceration dan fractination solution method. Chloroform fraction of brucea fruits were used for phytochemical assay and used for α-glucosidase inhibition method. The α-glucosidase activity was determined by measuring the p-nitrophenol release from the reaction of the enzyme and substrate p-nitrophenyl-α-D-glukopiranosida (p-NPG) at wavelength 400 nm. The phytochemical analysis indicates that the chloroform fraction of brucea fruit contain alkaloid, saponin, and tannin. The fraction at concentration 1, 1.5, and 2% (b/v) and acarbose 1% can inhibit α-glucosidase enzyme activity respectively 16.48%, 17.96%, 19.68%, and 81.16%.
Keyword: 

Judul: Desain Sistem Transfer Energi Nirkabel Berbasiskan Tesla Coil
Abstrak: Tesla coil merupakan alat yang ditemukan oleh Nikola Tesla yang dapat mentransmisikan daya tanpa kabel dengan memanfaatkan prinsip induksi elektromagnetik. Pada penelitian ini dibuat sebuah prototype Tesla Coil dengan menggunakan transistor C1970 dan receiver menggunakan rangkaian LC. Identifikasi alat meliputi pengaruh daya input transmitter terhadap receiver, bentuk signal yang dipancarkan transmitter, pengaruh jarak transmitter dan receiver, nilai efisiensi serta efek alat terhadap perangkat lain. Hasil pengamatan menunjukkan bahwa semakin besar daya input maka semakin besar daya yang dipancarkan oleh transmitter. Bentuk sinyal yang dipancarkan oleh transmitter berupa gelombang listrik AC sinusoidal dengan frekuensi ~2.9 MHz. Semakin jauh jarak receiver terhadap transmitter maka semakin kecil amplitudo gelombang AC yang diterima oleh receiver, menyebabkan semakin kecil daya yang diterima oleh receiver. Adapun nilai efisiensi terbesar penangkapan daya oleh receiver yaitu sebesar 0.00516 % serta terdapat gangguan pada alat-alat tertentu seperti monitor komputer dan radio.
Keyword: rangkaian LC, receiver, tesla coil, transistor C1970, transmitter