Judul: Aktivitas Antioksidan, Antibakteri, dan Degradasi Biofilm Streptococcus mutans Ekstrak Biji Lada Hitam (Piper nigrum).
Abstrak: Lada hitam diketahui memiliki banyak aktivitas hayati bermanfaat. Kandungan senyawa fenolik, alkaloid, dan minyak atsiri lada hitam berpotensi sebagai antioksidan, antibakteri, dan diduga mampu mendegradasi biofilm Streptococcus mutans. Tujuan penelitian ini adalah menentukan aktivitas antioksidan, antibakteri, degradasi biofilm Streptococcus mutans ekstrak pada pelarut yang berbeda, dan minyak atsiri biji lada hitam. Semua ekstrak dan minyak atsiri aktif sebagai antioksidan, dengan aktivitas terbaik pada minyak atsiri sebesar 139.05 mmol α-tokoferol ekuivalen/g sampel dan lebih baik dibanding butylated hydroxytoluene (BHT) 30.62 mmol α-tokoferol ekuivalen/g sampel. Identifikasi kualitatif senyawa aktif antioksidan dari ekstrak lada hitam dilakukan dengan kromatografi lapis tipis-bioautografi menggunakan pereaksi fosfomolibdat. Ekstrak etil asetat, kloroform, dan etanol memberikan 4-5 pita aktif sebagai antioksidan. Ekstrak dan minyak atsiri lada hitam memiliki aktivitas antibakteri Streptococcus mutans yang rendah. Sebagai degradator biofilm minyak atsiri memiliki persen degradasi tertinggi, yaitu 41% pada konsentrasi bahan uji 2000 μg/mL.
Keyword: alkaloid, fenolik, lada hitam, Streptococcus mutans

Judul: Essential oil of temu hitam (Curcuma aeruginosa Roxb.)„s rhizomes, stems, and leaves as antibacterial toward Streptococcus mutans and biofilm degradator on teeth
Abstrak: Rimpang temu hitam banyak digunakan sebagai antibakteri. Penelitian ini membandingkan kemampuan minyak atsiri rimpang, batang, dan daun temu hitam sebagai antibakteri Streptococcus mutans dan pendegradasi biofilm pada gigi menggunakan metode mikrodilusi. Minyak atsiri diisolasi dengan distilasi uap. Potensi antibakteri terbaik adalah minyak rimpang KHM=konsentrasi hambat minimum=15.63 μg/mL dan KBM=konsentrasi bunuh minimum=1000 μg/mL. KHM rimpang sama dengan tetrasiklin. Setelah difraksionasi dengan kolom maupun kromatografi lapis tipis preparatif, KHM dan KBMnya tidak lebih baik. Senyawa 2,2,5-trimetil-2‟(H)-5‟-6‟-dihidropirano[3‟,4‟,g]indan-1-on diduga paling berperan sebagai antibakteri S. mutans. Kemampuan degradasi biofilm minyak atsiri kasar temu hitam kurang kuat. Minyak atsiri batang lebih baik mendegradasi biofilm (IC50=1347 μg/mL) daripada rimpang dan daun. Setelah difraksionasi, beberapa fraksi minyak atsiri rimpang (F1, F2, dan F3) lebih baik kemampuan degradasinya tetapi IC50 lebih tinggi dari klorheksidin., Rhizomes of temu hitam are widely used as antibacterial. This research compare the potency of essential oil of rhizomes, stems, and leaves of temu hitam as antibacterial toward Streptococcus mutans and biofilm degradator on teeth. The essential oil was isolated by steam distillation. Rhizome‟s essential oil showed good potency as antibacterial with MIC=minimum inhibition concentration=15.63 μg/ml and MBC=minimum bactericidal concentration=1000 μg/ml. MIC of rhizome was same with tetracycline. MIC and MBC of rhizome‟s essential oil was smaller than fraction of column and preparative thin layer chromatography. The 2,2,5-trimethyl-2‟(H)-5‟-6‟-dihydropyrano[3‟,4‟,g]indan-1-one give better potency as antibacterial toward S. mutans. Essential oil of temu hitam was not stronger as biofilm degradator. Stem‟s essential oil was the better essential oil (IC50=1347 μg/mL) to degradate biofilm than rhizome and leave‟s essential oil, but some of fraction of rhizome‟s essential oil (F1, F2, and F3) have better potency than stem‟s essential oil but the IC50 was higher than chlorhexidine. Keywords: Antibacterial, biofilm degradator, essential oil, Streptococcus mutans
Keyword: antibakteri, minyak atsiri, pendegradasi biofilm, Streptococcus mutans

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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