Jurnal ILMU DASAR
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Comparison of Yeast Resazurin Versus MTT Assay in vitro Methods For Determining Acute Toxicity of Halogenated Alkanes
Get PDFHalogenated alkanes may have potentially human health effect as a result of their persistence, bioaccumulation and toxicity after their release from environment into the food chain and water products. It is leading to increase attention for legislation aimed at prevention and great pressure to reduce the production and emission rate of halogenated alkanes. Besides many research efforts to understand the fate and (eco)toxicological effects of the halogenated alkanes. Several investigators have used animal in vivo in conventional toxicity studies of halogenated alkanes. Nevertheless, experimental by using animal testing is always time and resource demanding. Thus, it is not deemed suitable for screening of large number of potential toxicants. The main objective of this work was to investigate the comparability of yeast resazurin assay versus MTT assay for determining in vitro acute toxicity (EC50) of halogenated alkanes. The MTT assay was conducted using Chinese Hamster Ovary (CHO cell), whilst yeast strains were used in yeast resazurin assay. The study demonstrates a comparability result to which halogenated alkanes is more toxic to CHO cell than to yeast cell
Preliminary Investigation: Stearidonic Acid Production by Genetically Modified Saccharomyces cerreviseae Using Linseed Oil as A Fatty Acid Source
Get PDFStearidonic acid (SDA); 18:4(n-3), an ω-3 Polyunsaturated Fatty Acid (PUFA), could be produced by Genetically Modified Saccharomyces cerreviseae (GMY) using Linseed Oil (LO) as fatty acid source. In nature, S. cerrevisae accumulates only very small amount lipid and contains until mono unsaturated fatty acids. But this GMY strain beside has capability to accumulate lipid, it also contains Δ6 desaturase gene which leads to convert α-Linolenic Acid (ALA); 18:3(n-3) to be SDA. Gas Chromatograph analysis of transmethylated LO sample showed that main component of fatty acid was ALA (about 57%), therefore LO can be used as a cheap source for other PUFA production. In order to provide ALA as a source for the yeast, enzymatic hydrolysis of LO using lipase was done. The lipase from Rhizomucor miehei (L4277-SIGMA) showed the highest activity among 5 lipases when 1 g/L LO in the medium for yeast (containing 6.7g/L yeast nitrogen base, 20 g/L glucose and 2.5g/L tergitol NP-40) was hydrolyzed. For SDA production, 1g/L LO in medium was aseptically hydrolyzed by lipase in 50 unit/mL for 18 hours at 30 oC and 140 rpm. The pre-culture of GMY (1% V/V) was then inoculated into the treated medium and 2.59 g/L dried cells were obtained after 5 days cultivation. ALA was accumulated in the cells at 0.06g/L (11% of total ALA in LO), and only 25% (0.015g/L) of accumulated ALA were converted to SDA. These results suggested that LO can be used as a source for PUFA production. In order to improve the productivity of SDA using GMY, hydrolysis of LO as well as cultivation condition and genetically improvement of the yeast must be highly considerated
Chemicals Identification Related To The Chemical Weapons Convention During The 15th Interlabory Proficiency Test
Get PDFIdentification of some chemical weapons in the water and organic sample has been carried out during 15th proficiency testing hold by OPCW (Organisation Prohibition of Chemical Weapon). Sample preparation method was adopted from Recommended Operational Procedure (ROP) from OPCW and Helsinki University, Finlandia. Prepared sample was identified by gas chromatography (FID and FPD), gas chromatography mass spectrometry (EI and CI mode) and Liquid chromatography mass spectrometry method.. From 7 spiking chemical weapons introduced to water and organic sample, 3 spiking chemicals could be identified (propylphosphonic acid, isoprophylphosphonic acid and 1,4 Bis 2-chloroethyl (thio) butane). One chemical was reported as Butyl S-2-diisopropylaminoethyl propylphosphonothiolate but obviously this is not a spiking chemical (category false positive identification)
Fabrication and Characterization Dye-Sensitized Solar Cell based on TiO2/SnO2 Composit Electrode and Polymer Electrolite
Get PDFA solid-state dye-sensitized solar cell based on TiO2/SnO2 composite electrode and polyethylene glycol (PEG) based electrolyte has been fabricated. The solar cell was formed in sandwich structure, which two electrodes sandwiching polymer electrolyte containing a redox couple (I-/I3-). One of the electrode was TiO2/SnO2 composite layer on TCO (transparent conducting oxide) coated glass substrate which sensitized with Ruthenium complex dye as electron donor, and the other electrode was a carbon sheet as a counter electrode. Active area of solar cell was 1.5 cm x 1 cmm. The solar cell was tested by irradiation with mercury lamp of 400 Watt with intensity of 30 mW/cm2 at a distance of 30 cm and sunlight with intensity of 36 mW/cm2. The cell tested with mercury lamp result in an open circuit voltage (VOC) of 420 mV, short circuit current (ISC) of 52 μA, maximum power (Pmax) of 10.4 μW, fill factor (FF) of 48% and energy conversion (η) of 0.023 %. On the other hand, the cell tested with sunlight source result in VOC=480 mV, ISC=48μA, Pmax=12.6 μW, FF=55% and η=0.023%
Embedding Cycle Graphs Complements
Get PDFA graph is embeddable on a surface if it can be drawn on that surface without any edges intersect. The cycle graphs can always be embedded on the plane and the torus, but this is not occurred for their complements. We prove that the maximum order of cycle graphs such that their complements still can be embedded on the plane is 6. But, the maximum order of cycle graphs such that their complements still can be embedded on the torus is 9. Also, the crossing number of complements of cycle graphs which can’t be embedded on the plane with minimum order will be presented
Nyale Sea Worm As Antibacterial Substances
Get PDFNyale is a sea worm that belongs to class of polychaete. It appears on a huge crowd, usually five days after the monsoon in February, at the surface of the sea for breeding. The colors of the female and male worms are green and brown, respectively. The worms are collected in nyale season, freezed-dryer, and extracted with ethyl acetate. Antimicrobial activity properties of the male worm extract are carried out toward benthos bacteria and clinical isolate bacteria using ciprofloxacin as comparing agent. The results show that, after colom chromatography, fraction number 1 and 4 have the best antibacterial activities (broadest spectrum) toward clinical isolate bacteria. All eleven fractions show also antibacterial activities toward nine benthos bacteria. The minimum inhibitory concentration (MIC) of fractions 1 and 4 toward six clinical isolate bacteria is 100 μg/ml. Meanwhile, fraction 4 exhibits two peaks in its HPLC chromatrogram
Determination of Subsurface Structure of Landslide Area According to Interpretation of Resistivity Data
Get PDFResistivity method is a useful geophysical tool for investigating landslides. It can be used to estimate the subsurface structure of a landslide mass, the depth of the failure surface, and the lateral extent of a landslide. High resolution of resistivity data were obtained by applying Schlumberger configuration, while penetrating deepness was obtained by applying Vertical Electrical Sounding (VES) configuration. Interpretation of subsurface condition showed there was soil layer in survey area which was indicated as slip surface triggering the landslide
The Synthesis Study of Sulfanilamide Analogue from Natural Substances Papaverine Alkaloid
Get PDFThe aim of this research was to synthesize sulfanilamide analogue from natural products papaverine alkaloid. Sulfanilamide is known as an antibiotic which has been used for treatment of infection. Theoretically papaverine could be converted to be sulfanilamide analogue by two steps reactions, first sulfonation of papaverine by sulfonic acid to produce sulfonyl chloride and second reaction of with ammoniac to produce. The formation of this product was analyzed by analytical thin layer chromatography and FT-IR. This analysis showed the formation of product quite difficult since the compound was easily reacted with water to form compound. Infrared spectra supported the formation of which showed vibrations at 1153.4 and 1265.2 Cm-1 due to absorption of sulfonyl group and at 3433.1 Cm-1 due to absorption of –OH group
The Roles of Nitrogen and Potassium to Phosphoenolpyruvate Carboxylase Activity in the Leaves of Ratoon Crop M 442-51 and PS 60 Sugarcane Varieties
Get PDFStudy on the roles of nitrogen and potassium to phosphoenolpyruvate carboxylase (PEP-Case) activity in the leaves of ratoon crop of M 442-51 and PS 60 cane varieties were conducted in the Indonesian Sugar Research Institute (ISRI) Pasuruan, East Java. The experiment was arranged in a factorial trial using a completely ran-domized block design with three replicates. The factors used as a treatments in this experiment were: (1) sugar-cane variety, i.e. M 442-51 (V1) and PS 60 (V2), (2) plant category, i.e. plant crop (PC) and second ratoon crop (RC2), (3) dosage of nitrogen, i.e. 1 q AS/ha (N1) and 8 q AS/ha (N2), and (4) dosage of potassium, i.e. 1 q KCl/ha (K1) and 5 q KCl/ha (K2). PEP-Case activity variable was observed on 0, 1 and 4 weeks after treatment (wat). The results of experiment showed that nitrogen (N) and potassium (K) nutrients as single or mixture treatments were increasing the activity level of PEP-Case in the cane leaves significantly. There was indication that the effect of N is stronger than that the effect of K to PEP-Case activity in the leaves of cane. On the other hand, it was found that the activity of PEP-Case in M 442-51 was higher than that on PS 60. However, when the availability of both nutrients was limited, the decreasing activity of PEP-Case on PS 60 was sharper than that found on M 442-51. Study on plant category showed that the activity of PEP-Case on PC was higher than that found on RC2. Reducing of PEP-Case activity on RC2 was predicted as one factor that caused reducing of RC2 productivity. Base on these findings, it can be concluded that PEP-Case activity model in the leaves could be used as an early characteristic of cane ratooring ability. There were indications that the ability of both Mn and Cu nutrients affected the increasing of PEP-Case activity better than that influenced by N and K nutrients, but it needs further investigation.Â
Statistical Inference for Modeling Neural Network in Multivariate Time Series
Get PDFWe present a statistical procedure based on hypothesis test to build neural networks model in multivariate time series case. The method involved strategies for specifying the number of hidden units and the input variables in the model using inference of R2 increment. We draw on forward approach starting from empty model to gain the optimal neural networks model. The empirical study was employed relied on simulation data to examine the effectiveness of inference procedure. The result showed that the statistical inference could be applied successfully for modeling neural networks in multivariate time series analysis