Homogenized Mushroom Tissue Based Biosensors

Homogenized Mushroom Tissue Based Biosensors ABSTRACT Homogenized mushroom (Agaricus bisporus) tissue based biosensors by using plant tissue materials is a relatively new development in the biosensor technology. A simple in dip stick kind of visual ethanol biosensor that based on immobalised alcohol oxidase (AOX) homogenized from mushroom tissue onto polyaniline (PANI) film for ethanol (> 5% concentration ) detection in toiletries products. The colour going to change from green to blue due to response of biosensor to the ethanol and the change of colour can be seen by naked eyes. Regarding the enzymatic reaction of ethanol, acetaldehyde and hydrogen peroxide will produced, then PANI film is latter going to be oxidised. The method used to immobalise AOX onro the PANI film is by adsorption. Regarding immobilisation process, AOX solution need to deposit on the PANI film and then left it at room temperature within 30 minutes until it dry. Scan and analyse the changes film’s colour to obtain the biosensor’s response characteris tics toward the ethanol. The biosensor respond. Therefore, this simple visual biosensor is suitable for all-range-aged community to determine the safeness of certain toiletries products from the ethanol. Keywords : Biosensor; Alcohol Oxidase Ethanol; Mushroom Tissue; Polyaniline; Toiletries 6.0Â  EXPERIMENTAL 6.1Â  Chemicals 10-40 units/mg protein of Alcohol Oxidase or simply called (AOX) (A2404, EC1.1.3.13) which extract from mushroom (A. Bisporus). These mushroom can be bought at fresh market as culture vegetables. Before use make sure store it at 4Â °C. In order to immobalization use 225 bloom of gelatin from calf skin and 25.0% glutaraldehyde. Ascorbic acid, 2-propanol, D-glucose, n-butanol and many more chemicals needed can be purchased from Sigma, St. Louis, USA. Aniline with AR-grade, gallic acid (G7384) and l-cysteine (W326305) can be purchased from Sigma Aldrich (Saint Louis, MO, USA). Ethanol which contain >99.5%, methanol, orthophosphoric acid (85%) and sodium hydroxide (pellets) can be delivered by Merck (Nottingham, UK). All needed chemicals are from commercial source which in analytical grade. Millipore Direct-QTM 5 purification system provide the Milli-Q water. Prepare ethanol’s stock solutions in 0.1 M phosphate buffer at suitable pH daily and store it in refrigerator at 4 Â °C. For pH studies, 0.1 M of the phosphate buffer solutions with pH values between 4 and 8 were can be used and to measure the pH value, use commercial glass electrode and pH-meter (model 9318, Hanna Instruments, Woonsocket, RL, USA) and calibrate it at the pH values of 4.00, 7.00 and 9.00. 6.2Â  Homogenization of Mushroom Tissue Homogenize 200 mg mushroom tissue in the 400ml phosphate buffer. Mix this 300 ml homogenate and 10 mg gelatin. Incubate it for 5 minutes at 38Â °C to make sure the gelatin is dissolved. 6.3Â  Preparation of Polyaniline (PANI) Film In order to prevent bumping in the aniline, purify the aniline with vigorous and rapid stirring by distilled under vacuum. Prepare PANI dispersion as nanofibre and Huang and Karner (2006) already mention the method to should to be used to build it. Mix 3.2 mmol or 0.3 g of purified aniline with 10 mL of 1.0M Hydrochloric Acid (HCL). Mix 0.8 mmol or 0.18 g of Ammonium peroxydisulfate into another 10 mL aliquot acid solutions. Add aniline-acid to oxidant and these two solution will mix rapidly within 30 seconds and then allow it to react in undisturbed overnight condition. On the next day, wash the polyaniline by using water and centrifuged. Supernatant liquor with pH 3.3 and strong green colour will form and it is indicate as the PANI particles which can be observed after several times of washing. Any remaining particles with size larger than 1ÃŽ ¼m must be removed before casting by passing the dispersion through a 55-mm glass fiber filter (Whatman GFA, Kent, UK) which is attach to va cuum source. Cast directly PANI dispersion on a substrate of polystyrene and then, left the thin film of PANI that on the sheet of polystyrene in the dark to dry after cut it into individual in 10mm2 size. Next, store that ready film at 4Â °C. The thickness must be 0.7ÃŽ ¼m and use SEM images to determine it. To make sure the thickness of the film is always in the same magnitude order, it must be determined routinely. Then, choose 0.7 ÃŽ ¼m thickness of PANI film to use for the further experiment result in good of PANI film fabrication reproducibility. 6.4Â  Enzyme Immobilization Immerse the PANI film in 0.1 M phosphate buffer which have pH 7.0 to make sure the condition of PANI film is at natural condition which means at pH 7.0. After that, deposit appropriate concentration about 10 ÃŽ ¼L of AOX solution which is from homogenate of mushroom tissues and phosphate buffer on the PANI film and left it to dry within 30 minutes. For the further use, store this PANI film with immobilised AOX at 4 Â °C. 6.5Â  Biosensor Construction Construct a dip stick test visual biosensor of PANI film with immobilized AOX as Figure 1, connect AOX/PANI film with a handle which made by cellulose paper or can use transparent plastic tape. To way to use this this dip-stick format visual biosensor by just dipping this kind of biosensor into the toiletries sample solution for a several seconds (Â ±5 s), then the change of colour can be seen by baked eye if the concentration of ethanol is >5% since that only amount allowed to be in toiletries products and use image analysis for the quantitative measurement change of colour. (a)(b) Figure 1: (a) dip stick format of biosensor (b) dip biosensor into toiletries sample solution (Kuswandi et.al,2014) 6.6 Colour Change Recording See the change of colour by naked eye during alcohol detection since this biosensor is kind of visual mode. Use scanner for example Canon, Cano Scan, Japan and Tokyo for quantification of colour measurements. The presence of ethanol exceed 5% of concentration in toiletries sample solutions will change the colour of the biosensor from green to blue. The detection can be done by dipped the biosensor which in the form of dip stick test in the sample solutions in 5 seconds. Use ImageJ program which can be used as online applet, free download application or can be used in any computer together with Java 5 (Dougherty, 2009 Rueden et.al, 2007) in order to assess the colour after it has been scanned. The purpose s to determine the mean RGB colour value. 7.0Â  EXPECTED RESULT The expected result from this research is the colour of dip stick AOX/PANI film biosensor will change from green to blue if there presence of >5% of ethanol in toiletries products after the biosensor is dipped into the toiletries sample solutions for 5 seconds. Since this is the visual mode biosensor, the change of colour can easily seen by naked eyes. On the hand, use scanner (Canon, Cano Scan, Japan, Tokyo) for quantitative colour measurement and then use ImageJ program to assess the colour change of biosensor and to determine the mean RGB colour value. (Collins, 2007)

Cocaine and the Brain: The Neurobiology of Addiction Essay -- Biology

Cocaine and the Brain: The Neurobiology of Addiction In the eyes of the public, the word addict stirs up a negative image: a person of low moral character who willfully chooses to engage in questionable behavior. This image is perpetuated in the media; on a recent episode of E.R., the chief surgeon criticizes another doctor for allowing a heroin addict (who has been treated for an abscess) to exchange a dirty needle, explaining "we donà ¢t want these low-lives hanging around the hospital." The social stigma attached to addicts reflects the great gap that exists between scientific knowledge and public perception of addiction. Just as mental illness was viewed as a social problem instead of a medical issue until the last several decades, drug addiction continues to be seen as a character flaw instead of as the biological problem that it is. As defined by the American Psychiatric Association, addiction is a "chronically relapsing disorder that is characterized by three major elements: (a) compulsion to seek and take the drug, (b) loss of control in limiting intake, and (c) emergence of a negative emotional state when access to the drug is prevented" (1). This disorder results from the repeated use of a drug over a prolonged period of time, causing physical changes in the brain. Perhaps the most addictive of drugs is cocaine. Cocaine acts on the mesoaccumbens dopamine (DA) pathway of the midbrain, extending from the ventral tegumental area (VTA) to the nucleus accumbens (NAc). (2). This pathway is also known as the reward pathway as it is the area of the brain that is activated when someone has a pleasurable experience such as eating, sex, or receiving praise. (NOTE: The reward pathway was discovered through the technique of... ...se%2fform%2facademic%2fs_genjourn_more.html%25a3AD_FORM%25a4s_genjourn%25a3T1%25a4cocaine%20addiction%25a3S1%25a4Title%25a3S2%25a4AND%25a3T2%25a4Morris%2c%20Kelly%25a3S3%25a4author%25a3S4%25a4AND%25a3T3%25a4%25a3S5%25a4Title%25a3date%25a4AFT%25a3after%25a45%3aYR%25a3frm_rng%25a4%25a3to_rng%25a4%25a3srccat%25a4GENMED%3bALLJNL%25a3source%25a4$srccat%25a3pubtitle%25a4%22The%20Lancet%22%25a3srclf%25a4%25a3srclf_group%25a4%25a3srclf_title%25a4%25a3&wchp=dGLSzS-lSlAl&_md5=9d45ca951ebfccd3b6596b38d0b83ce7 19) Combining Drug Counseling Methods Proves Effective in Treating Cocaine Addiction , Information on drug counseling http://www.nida.nih.gov/NIDA_Notes/NNVol14N5/Combining.html 20) Coping Skills Help Patients Recognize and Resist the Urge to Use Cocaine , Information on therapy for cue-induced relapse http://www.nida.nih.gov/NIDA_Notes/NNVol13N6/Coping.html

Africans in the Berlin Conference

Africans in the Berlin Conference The Berlin Conference of 1884-1885 established most of the borders of contemporary nation-states on the African continents today. The Conference set in motion the â€Å"scramble for Africa. † Out of the 14 African states no African leader was present at the conference to assert claims to territory and to agree to regulations on trading. Five of the states at the conference did not even end up with any colonies but had more of a say than all the African leaders. The boundaries in Africa, drawn during the Berlin Conference, greatly attributed to the political unrest in Africa.During the Berlin Conference all the participants signed a notion that said they could not have colonies unless they have full control of the territory they encompassed. The European powers had to send expeditionary forces to pacify what were called their African â€Å"spheres of influence. † This process was bloody and ugly due to the amount of Africans fighting bac k. These pacifications lasted all the way up to World War 1. These uprisings caused anarchy in some places in Africa. Only Ethiopia successfully kept their freedom militarily. But all across Africa, hundreds of polities large, and small fought to destroy these superimposed boundaries.Pre-existing political entities found themselves arbitrarily or deliberately divided in two, three, or even four parts. The main Hausa territories were split between French Niger and British Nigeria, the Maasai suddenly had to practice nomadic pastoralism across a line between German and British East Africa. Conflicts in Africa could definitely were partly caused by boundaries drawn during the Berlin Conference. Uganda’s numerous civil conflicts are pure evidence. Also the Nigerian Civil War of 1967-1971 can partly be traced back to the Berlin Conference.Conflicts between states also can be traced to the Conference because of the ridiculous political geography they put in place. Examples of these conflicts are Cameroon and Libya’s with Chad. The finger of Namibia that sticks out across the top of Botswana, known as the Caprivi Strip has been a geopolitical hotspot ever since it appeared on the map. The Berlin Conference was a very unjust and unethical. They drew out boundaries for Africa without the African leaders consent and then took over all of the nations. The Berlin Conference was definitely connected to the political unrest in Africa.

Calculating Limiting Reactant of a Chemical Reaction

Chemical reactions rarely occur when exactly the right amount of reactants will react together to form products. One reactant will be used up before another runs out. This reactant is known as the limiting reactant. Strategy This is a strategy to follow when determining which reactant is the limiting reactant.Consider the reaction:2 H2(g) O2(g) → 2 H2O(l)If 20 grams of H2 gas is reacted with 96 grams of O2 gas, Which reactant is the limiting reactant?How much of the excess reactant remains?How much H2O is produced? To determine which reactant is the limiting reactant, first determine how much product would be formed by each reactant if all the reactant was consumed. The reactant that forms the least amount of product will be the limiting reactant. Calculate the yield of each reactant. The mole ratios between each reactant and the product are needed to complete the calculation:The mole ratio between H2 and H2O is 1 mol H2/1 mol H2OThe mole ratio between O2 and H2O is 1 mol O2/2 mol H2OThe molar masses of each reactant and product are also needed:molar mass of H2 2 gramsmolar mass of O2 32 gramsmolar mass of H2O 18 gramsHow much H2O is formed from 20 grams H2?grams H2O 20 grams H2 x (1 mol H2/2 g H2) x (1 mol H2O/1 mol H2) x (18 g H2O/1 mol H2O)All the units except grams H2O cancel out, leavinggrams H2O (20 x 1/2 x 1 x 18) grams H2Ograms H2O 180 grams H2OHow much H2O is formed from 96 grams O2?grams H2O 20 grams H2 x (1 mol O2/32 g O2) x (2 mol H2O/1 mol O2) x (18 g H2O/1 mol H2O)grams H2O (96 x 1/32 x 2 x 18) grams H2Ograms H2O 108 grams O2O Much more water is formed from 20 grams of H2 than 96 grams of O2. Oxygen is the limiting reactant. After 108 grams of H2O forms, the reaction stops. To determine the amount of excess H2 remaining, calculate how much H2 is needed to produce 108 grams of H2O.grams H2 108 grams H2O x (1 mol H2O/18 grams H2O) x (1 mol H2/1 mol H2O) x (2 grams H2/1 mol H2)All the units except grams H2 cancel out, leavinggrams H2 (108 x 1/18 x 1 x 2) grams H2grams H2 (108 x 1/18 x 1 x 2) grams H2grams H2 12 grams H2It takes 12 grams of H2 to complete the reaction. The amount remaining isgrams remaining total grams - grams usedgrams remaining 20 grams - 12 gramsgrams remaining 8 gramsThere will be 8 grams of excess H2 gas at the end of the reaction.There is enough information to answer the question.The limiting reactant was O2.There will be 8 grams H2 remaining.There will be 108 grams H2O formed by the reaction. Finding the limiting reactant is a relatively simple exercise. Calculate the yield of each reactant as if it were completely consumed. The reactant that produces the least amount of product limit the reaction. More For more examples, check out Limiting Reactant Example Problem and Aqueous Solution Chemical Reaction Problem. Test your new skills by answering  Theoretical Yield and Limiting Reaction Test Questions. Sources Vogel, A. I.; Tatchell, A. R.; Furnis, B. S.; Hannaford, A. J.; Smith, P. W. G. Vogels Textbook of Practical Organic Chemistry, 5th Edition. Pearson, 1996, Essex, U.K.Whitten, K.W., Gailey, K.D. and Davis, R.E. General Chemistry, 4th Edition. Saunders College Publishing, 1992, Philadelphia.Zumdahl, Steven S. Chemical Principles, 4th Edition. Houghton Mifflin Company, 2005, New York.