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Book Review: The Disappearing Spoon by Sam Kean

The Book – The Disappearing Spoon: And Other True Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements

The Author –  Sam Kean

Published on – July 12, 2010

Published by – Little, Brown and Company 

This book can be described as the story telling at its best. The author, Sam Kean describes the evolution of the periodic table with real life stories on how the elements were discovered by their inventors. Kean narrates about the lives of these inventors such as  Marie Curie and Pierre Curie and how their findings impacted on the industry as well as their personal lives. For example, how the  theoretical physicist Maria Goeppert-Mayer facing comparative disadvantages owing to her sex, though she won the Nobel Prize in Physics for her outstanding work.

Then this Pons and Fleischmann story about “Cold Fusion” might be one of the top stories that this book carries.  In 1989, two electrochemistsMartin Fleischmann and Stanley Pons, reported that their apparatus had produced excess heat of a magnitude they asserted would defy explanation except in terms of nuclear processes. Kean describes how this experiment made and unmade Pons and Fleischmann within a few months of time, from being a part of historical scientific breakthrough to being a part of a well-orchestrated con act.  

Pons and Fleischmann with their apparatus of “Cold Fusion” experiment

From “Cold Fusion” story of Pons and Fleischmann, Kean makes his way to introduce pathological science by narrating the story of William Crookes. Due to the grief of the tragic loos of his brother, William Crooks has turned to spiritualism to try to communicate with his brother. He published “Notes of an Enquiry into the Phenomena Called Spiritual” in 1874 and his coworkers thought he was crazy. Crookes eventually left the spiritual research and returned to science and focused on other topics. He finally ends up being a key contributor to the body of knowledge of chemistry.

The theme of each chapter – politics, money, war, the arts, health, toxins, radiation and so on – is prescribed by groups of elements in the periodic table and the things they tell us about the nature of matter; about the stardust origins of the elements; about the compounds they make and why some elements are more reactive than others; and why the table falls into a pattern so obvious that its begetters were able to predict the characteristics of elements not yet identified. The pace is enthusiastic, the tone and language are pitched at the young or the non-chemical and the examples are pleasingly unexpected.

Kean tells the story of Robert Falcon Scott’s expedition to the South Pole. Many scientists were attempting to be the first people to reach the South Pole, but a team led by Roald Amundsen had already reached it. The Amundsen team safely returned from the journey, but Scott’s team was delayed at the pole due to snow flurries and fuel supplies lost due to the high temperatures. Robert Falcon Scott and his companions died on the South Pole.

Kean discusses elements that were put through extreme temperatures to be able to get a sample. Xenon and krypton were put to temperatures as low as −240 F. Kean explains how laser beams are produced by yttrium and neodymium. Kean states that the most powerful laser has more power than the US and it uses crystals of yttrium spiked with neodymium. While lasers produce visible light, masers do not, instead produce microwaves. Masers were considered impossible until Charles Townes worked on them, earning him a Nobel Prize in 1964.

Kean should get the credit for coming up with a book on the subject of chemistry which even a non-chemist can read end to end in a one go due to Kean’s demonstrated ability of top story telling.

How to balance chemical equations

What is a chemical equation?

A chemical equation is the symbolic representation of a chemical reaction in the form of symbols and formulae, wherein the reactant entities are given on the left-hand side and the product entities on the right-hand side.

How to balance a chemical equation?

What we are going to demonstrate below is the Algebraic Method or the Bottomley’s Method of balancing a chemical

For example, the following chemical equation can be considered for the purpose of demonstrating how to balance a chemical equation.

PCl5 + H2O –> H3PO4 + HCl

The first step is to assign arbitrary multipliers to each member substance of the equation.

a PCl5 + b H2O –> c H3PO4 + d HCl

Here, the objective is to ascertain the values of the arbitrary multipliers which make the chemical equation, balance. Hence the next step is to come up with linear equations of arbitrary multipliers by balancing the different elements of the two sides of the equation.

By balancing the element Phosphorus (P) –> a = c —-> equation (1)

By balancing the element Chlorine (Cl) –> 5a = d —–> equation (2)

By balancing the element Hydrogen (H) –> 2b = 3 c + d —–> equation (3)

By balancing the element Oxygen (O) –> b = 4c —–> equation (4)

Now we have 4 linear equations with 4 unknowns of a, b, c and d. The next step is to solve these 4 linear equations to find the 4 unknowns.

Since a = c, substituting c with a –>

5a=d

2b = 3a + d

b = 4a

Since b = 4a, substituting b with 4a —>

5a = d

8a = 3a + d —> 5a = d

Lets assume a = 1

Then d=5, b=4 and c = 1

Finally the balanced chemical equation is as below.

PCl5 + 4 H2O –> H3PO4 + 5 HCl

Krypton-85

Krypton-85 is a radioactive isotope of Krypton. It is primarily used in High Intensity Discharge Lamps as well as in HMI film lights.

Identification of Krypton-85

The CAS Registry Number for this radioactive isotope is 13983-27-2.

Nucleus of Krypton-85

There are 49 Neutrons and 36 Protons in the Krypton-85 isotope.

Symbol of Krypton-85

The symbol denoting Krypton-85 is written as 85Kr.

Production of Krypton-85

Krypton-85 is a radioactive gas found in small quantities in the atmosphere. It is naturally produced when stable Krypton-84 reacts with the incoming cosmic rays. Almost 1 cm3 of Krypton-84 is present in per cubic meter of atmosphere. Atmospheric Krypton-85 is mostly produced by volcanoes, earthquakes, nuclear power plants and nuclear explosions.

Krypton 85 Picture


Picture 1 – Krypton 85

Since mid-1940s, much greater quantities of Krypton-85 than that found in nature have been manufactured as a byproduct of nuclear fission. When Uranium-235 or some other fissile nucleus goes through a fissile reaction, it gets split into two portions or fragments having 2 or 3 neutrons and mass numbers between 90 and 140. The fission yield of Krypton-85 is around 0.3%; i.e., approximately 3 atoms of Krypton-85 are generated per 1000 fissions. Most of the mass of Krypton-85 is converted directly to Rubidium-85 and do not go through the long standing state of nuclear isomer.

Properties of Krypton-85

The various physical and chemical properties of Krypton-85 are represented below:

Appearance

It is a colorless noble gas.

Odor

This gas does not have any characteristic odor.

Atomic Number

The atomic number of Krypton-85 is 36.

Mass Number

The mass number of Krypton-85 is 85.

Isotope Mass

The Isotope mass of Krypton-85 is 84.9125273(21) u.

Mass Excess

In nuclear science, the mass excess of a substance is the difference between the actual mass and the mass number of the substance in atomic mass units. The mass excess of Krypton-85 is -81.480267 MeV (megaelectronvolts).

Decay Mode

Krypton-85 decays through emission of beta particles.

Decay Energy

Energy released by Krypton-85 during decomposition is 0.687 MeV (megaelectronvolts).

Q Value

In nuclear chemistry, the Q value for a specific nuclear reaction represents the total amount of energy which is released by that specific reaction. The Q Value of Krypton-85 is 687.06 keV (kiloelectronvolts).

Gas Density

The gas density of Krypton-85 at a temperature of 21.1°C is 0.2172 lb/ft3 (3.479 kg/m3).

Boiling Point

The boiling point of Krypton-85 is -153.4°C.

Freezing Point

The freezing point of Krypton-85 is -157°C.

Critical Pressure

The critical pressure of Krypton-85 is 798.0 psia (5502 kPa abs).

Daughter Nuclide

Rubidium-85 is produced as a daughter nuclide when Kr-85 undergoes decomposition.

Magnetic Dipole Moment

The magnetic dipole moment of Krypton-85 is 1 μN.

Spin Parity

Spin parity of Krypton-85 is represented as Jπ = 9/2+ (atomic fermion).

Binding Energy

Binding energy per nucleon of Krypton-85 is 8.698562 MeV.

Specific Activity

The specific activity SA of Krypton-85 is 14.526 TBq/g (terabecquerels per gram).

Specific Volume

The specific volume of Krypton-85 at a temperature of 21.1°C is 4.604 ft3/lb (0.287 m3/kg).

Specific Gravity

The specific gravity of Krypton-85 at a temperature of 21.1°C is 2.899.

Electric Quadrupole Moment

The electric quadrupole moment of Krypton-85 is 0.433 eb (electron barns).

Lifetime

The total lifetime of Krypton-85 is 15.482 years.

Half-Life of Krypton-85

In radioactivity, half-life is the time taken by a specific amount of a radioactive substance that undergoes decomposition to be decreased by half. The half-life for Krypton-85 is 10.756 years.

Radioactive Decay of Krypton-85

The unstable nucleus of Krypton-85 undergoes decay to form the stable compound Rubidium-85. The most common form of decay undergone by Krypton-85 is by the emission of beta particles with a maximum energy release of 687 keV and an average energy release of 251 keV. This occurs with a frequency of almost 99.57%. The second most common form of decomposition occurring with a frequency of almost 0.43% also involves beta particle emission; the maximum energy released in this case is 173 keV. The third most common method of decomposition is through gamma ray emission. Energy released during gamma ray emission is around 514 keV.

Uses of Krypton-85

The various common uses of Krypton-85 are listed below:

  • Krypton-85 is frequently used for lighting purposes. The gaseous substance is used in arc discharge lamps for HMI film lights which are prevalently used in the entertainment industry. Krypton-85 is also used in the manufacturing of High Intensity Discharge lamps required for outdoor lighting. The discharge tubes of lamps are filled with Krypton-85 which acts as an easily ignitable fuel.
  • Trace amounts of Krypton-85 are used in the sealed spark gap assemblies of ignition excitors which are utilized in some older jet engines or turbines for obtaining uniform operation and consistent ionization levels.
  • Krypton-85 was used in the electron tubes of cold-cathode voltage regulator. A known example is the type 5651.
  • Krypton-85 is also used while inspecting the components of an aircraft for small defects. The gaseous substance is passed through the small cracks that might be present in aircraft components which are then detected by autoradiography. This procedure is known as “krypton gas penetrant imaging”. In this way cracks and damages in the aircraft gets detected. Krypton-85 gas is capable of passing through smaller openings and pores unlike the liquids that are used in fluorescent penetrant inspection and dye penetrant inspection.
  • The gaseous substance Krypton-85 is utilized to detect cracks and leaks in pipes and semiconductors.

Krypton 85 in the Atmosphere

Between 1945 and 1962, almost 5 megacuries (190 PBq) of Krypton-85 got released in the atmosphere due to the several nuclear weapons tests that were carried on during this time. Nuclear accidents over the years also play a major role behind the presence of atmospheric Krypton-85. The Three Mile Island nuclear power plant accident in 1979 released around 50 kilocuries (1,900 TBq) of Krypton-85. The Chernobyl accident in 1986 released almost 5 megacuries (190 PBq) of Kr-85. The concentration levels of Krypton-85 in the atmosphere intensified around 1970, reaching around 10 pCi/m3 (around 0.4 Bq/m3). From that time onwards the atmospheric presence of Krypton-85 has sharply declined, mainly due to the combination of factors such as reducing the production of Plutonium, the ending or stopping of nuclear weapon tests and the short half life of the radioactive isotope.

A large nuclear power plant can produce nearly 300 kilocuries (11,000 TBq) of Krypton-85 in a year; the entire portion or at least the majority of it gets stored in the spent nuclear fuel rods. Nuclear reprocessing causes dissolution of the spent fuel which releases Krypton-85 in the atmosphere. The substance can also be stored as nuclear waste.

Material Safety Data Sheet (MSDS)s of Krypton-85

Health Hazards

Krypton-85 is a radioactive isotope and although there may be small traces of this gas present in the atmosphere, a direct exposure to significant quantities of this gas can be hazardous to health. The substance radiates beta and gamma particles which can cause damaging of tissues on direct contact with the physical body. The principal way in which radiation poisoning can occur is through the inhalation of this gas. The gas is a noted asphyxiating agent and inhaling Krypton-85 can lead to serious breathing problems, mental failure, loss of consciousness, aggravate already existing problems of the heart, lungs or the circulatory system, decrease the ability to move or perform various regular tasks, impair coordination, convulsions or even death.

When the skin is exposed to this substance it can cause frostbite. The notable symptoms of frostbite include changing of skin color to grayish-yellow or white. Severe mechanical injury may be caused by chronic exposure to this gas. The substance is also considered to be a potential carcinogen according to some sources and exposure to it should be kept at a minimum level under all circumstances.

First aid measures

Eye Contact: If the eyes come in contact with the substance, the eyes should be covered with a bandage and immediate medical attention is required to ensure further safety.

Ingestion: It is highly unlikely that a person can get exposed to Krypton-85 through ingestion.

Inhalation: The victims should be immediately moved to an area of fresh air. If the victim exhibits signs of oxygen deprivation, oxygen supply or cardio-pulmonary resuscitation should be administered by trained personnel.

Skin Contact: The areas infected by frostbite should be washed with warm water. However, it is important that the water should be warm and not hot. In case warm water is unavailable, the affected areas should be wrapped gently using bandages or blankets. A dermatologist is to be consulted to ensure further skin safety.

Fire fighting measures

Krypton-85 is a non-flammable, inert gas. However, containers storing the gas might burst when exposed to heat. While dealing with fires involving Krypton-85, firefighters should wear adequate equipments of personal protection.

Accidental release measures

If there is a leak, the operator in charge should close the source of the gas immediately to avoid further damage. The room should be evacuated and no one should be allowed to enter unless it is considered safe to do so. To check if the leaked material has dissipated, Geiger-Mueller Detector should be used. An oxygen monitor should be used to check the oxygen level of the room.

Handling

Since this is a radioactive substance, the workers or employees involved in dealing with this chemical should have the required training to deal with radioactive materials. The cylinders storing the chemical should be checked regularly for leakages and corrosions.

Storage

The cylinders storing the chemical should be stored upright. They should be firmly secured so that they do not fall over or break at any point. The areas storing the cylinders should be dry and well ventilated. The temperature should be kept below 52°C.

Krypton-85 is a valuable radioactive isotope with many industrial and commercial uses.

References:

http://www.spectragases.com/content/upload/AssetMgmt/PDFs/MSDS/lighting/MSDS_Krypton-85InertBalanceLessThan%200.01TBq-1163%20_5-03-07.pdf

http://www.wolframalpha.com/entities/isotopes/krypton_85/3c/3o/uh/

http://en.wikipedia.org/wiki/Krypton-85

http://www.ead.anl.gov/pub/doc/krypton.pdf

Technetum-99m

What is Technetium-99m?

Technetium-99m is a nuclear isomer of Technetium 99. It is a radioactive substance that radiates “Gamma Rays”.

Technetium 99m Symbol

It is symbolized as 99mTc. The matastable state of the nuclear isomer is indicated by the “m”. This state is created by exciting the nucleons (neutrons or protons) of an atomic nucleus.

Technetium-99m Radiation

This nuclear isomer is radioactive and it radiates “Gamma Rays” (γ).

Technetium-99m Half Life

When a radioactive substance is undergoing decay, the time it takes to decrease by half is indicated as its Half Life. Technetium 99m undergoes gamma radiation and it takes 6 hours to decrease by half. That means the half life of this substance is 6 hours.

It has a considerably long half life considering the fact that it emits gamma ray. Usually, the half life of radioisotopes undergoing gamma decay is too short.

Production of Technetium-99m

Technetium 99m is not a natural but an artificially produced substance. It is the product of Molybdenum 99 (99Mo) caused by radioactive decay (decay-product). To produce this nuclear isomer, Molybdenum 98(98Mo) is first bombarded with a proton. This produces 99M that has a half life of 66 hours. The 99M decays to produce metastable Technetium (Tc) or 99mTc.Producing Technetium 99m in this process is allowed only for medical purposes.

The first technetium-99m generator, 1958.


Picture 1 – The first technetium-99m generator, 1958.
Source – en.wikipedia.org

Technetium 99m Generator

Technetium 99m Generator is the name for the device used to produce metastable Technetium. With the help of this generator, 99mTc is extracted from decaying Molybdenum 99. 99Mo has a long half life of 66 hours. So, the generator and the 99Mo can easily be carried away to the place where the decay product 99mTc is required.

Properties of Technetium-99m

Here are some basic properties of this nuclear isomer:

Atomic Number

The atomic number of Technetium 99m is 43.

Atomic Weight

The atomic weight of this substance is 99.

Physical State

It is a radioactive metal which is silver-grey in color.

Solubility

99mTc is soluble in Nitric Acid, Aqua Regia and concentrated Sulfuric Acid. It is insoluble in Hydrochloric Acid.

Technetium 99m in Nuclear Medicine

Radioactive isotopes are used in Nuclear Medicine. The radioactive decay of the isotopes is relied upon to diagnose and treat the patient. The function of this branch of medicine depends on the concept that the body reacts to substances differently when there is a disease present.

To diagnose the disease, the radioactive substance is bound to another chemical substance that can work inside the body without causing any harm. After that, both the chemicals are transported inside the body. As a result, the radioactive isotope can work as a medical tracer from inside the body. It can be detected by special medical equipments.

As 99mTc has a much longer half life than other gamma ray radiating isotopes, it is very useful in the field of nuclear medicine.

Technetium 99m in Bone Scan

It is widely used to scan fractures and other problems of bones. Ligand Methylene-Diphosphonate (MDP) is a substance that is easily taken up by the bones. So, Technetium 99m is chemically attached to it to be easily transported to the bones via hydroxyapatite for imaging. In this way, the diagnosis of the bones can be easily done.

Technetium 99m Albumin Aggregated (MAA)

It is the name of a radiopharmaceutical substance. It is used in nuclear medicine. The MAA is an injectable substance.

Technetium 99m Medicines

The names of the principal medicines of 99mTc are:

  • Technetium sestamibi or Cardiolite (trade name)
  • Technetium tetrofosmin or Myoview (trade name)

Uses of Technetium 99m

It is used as a medical tracer in radioactive isotope medical tests. 99mTc is used in the treatment of the following diseases:

  • Brain
  • Myocardium
  • Thyroid
  • Lungs
  • Liver
  • Gallbladder
  • Kidney
  • Skeleton
  • Blood
  • Tumors

Benefits of Technetium-99m

Some of the main benefits of using this radioactive substance are mentioned bellow:

  • The principal benefit of this radioactive substance is its long half life. 6 hours is long enough for various medical examinations to be done. Also, it is short enough for the99mTc to be eliminated from the system without causing any harm.
  • The radiation dose to the patient remains low because 99mTc emits gamma ray.
  • 99mTc can be tagged or attached to a variety of chemicals so that it can be used for the treatment of various parts of the human body.
  • It emits the 140 keV gamma rays, which is readily detectable.

It is one of the most useful radioactive isomers and is widely used in nuclear medicine. It can only be produced artificially for medicinal purposes. Technetium 99m has great contribution in the advancement of nuclear medicine.

References:

http://www.bnl.gov/bnlweb/history/tc-99m.asp

http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/technetium.html

http://www.furryelephant.com/content/radioactivity/alpha-beta-gamma-radiation/producing-technetium-99m/

http://www.technetium.org/isotopes/general/technetium-99m-generator.html

http://www.medindia.net/patients/patientinfo/radioisotopescan_technetium.htm

Bicuculline

What is Bicuculline?

It is a plant alkaloid that consists of GABA antagonist properties. It is used for analysis of GABA function of the human nervous system. It is a light-sensitive Isoquinoline alkaloid that is extracted from plants like Dicentra Cucullaria.

History of Bicuculline

This substance was first identified among other plant alkaloid extracts in 1932. It has been distinguished from Dicentra cucullaria, Fumariaceae, Adlumia fungosa and a number of Corydalis species.

bicuculline images

Picture 1: Bicuculline Molecular Structure
Source: chemblink.com

Where Bicuculline is found?

This alkaloid can be extracted from plants that belong to the family Fumariaceae.

Pronunciation of Bicuculline

It is pronounced as bī′kū-kyū′lēn.

Action of Bicuculline

The main action of this alkaloid is on the ionotropic GABAA receptors. These are ion channels that are mainly associated with the passage of chloride ions through the cell membrane. The ionotropic GABAA receptor gives rise to anxiety in humans. Drugs that aim at treating anxiety actually target the GABAA receptors. Mild drug dosage reduces anxiety while a greater dose can lead to sedation or sleep. In case of a medicinal overdose, death may occur. Bicuculline administration needs to be monitored by professional medical care providers. Overdose of the alkaloid may give rise to life-threatening consequences for patients.

Some of the drugs that target these receptors include

  • Muscimol
  • Gaboxadol
  • Nonbenzodiazepines
  • Barbiturates
  • Ethanol
  • Neuroactive steroids
  • Inhaled anaesthetics
  • Picrotoxin
  • Bicuculline benzodiazepines

Epilepsy Use of Bicuculline

Bicuculline inhibits the influence of the GABAA receptors on specific neurons. This is the reason why the substance is said to imitate epilepsy. This property of this alkaloid is utilized in laboratories around the world. Researchers use the GABA receptor-antagonist properties in the in vitro analysis of epilepsy. The study is usually carried out in cortical or hippocampal neurons in organized rodent brain slices.

The International Union of Basic and Clinical Pharmacology (IUPHAR) is a voluntary scientific organization that has set Bicuculline sensitivity as a main criterion in defining GABAA receptors.

Other Uses of Bicuculline

Apart from being a potent antagonist of GABAA receptors, this alkaloid can also be used for other purposes. These include

Potassium Channel Blocking

The substance can be used to obstruct Ca2+-activated potassium channels.

Regulating Phrenic Nerve Bursts

This substance can be used to enhance the amplitude of the Phrenic nerve bursts. Phrenic nerve is one of two nerves that originate from the base of the cervical spine and travels down the thorax to stimulate the diaphragm and regulate breathing. The alkaloid can also change the internal and duration of bursts.

Chemical Information of Bicuculline

The molecular mass of this alkaloid is 367.352 g/mol. Its chemical formula is C20H17NO6.

Solubility of Bicuculline

This substance is insoluble in water. Bicuculline methiodide is a form of this alkaloid that is capable of being dissolved in water. It can be dissolved in water that has a concentration of 10 milligrams per milliliter.

Bicuculline methiodide pictures


Picture 2: Bicuculline Methiodide
Source: guidechem.com

References:

http://dictionary.sensagent.com/Bicuculline/en-en/

http://www.wrongdiagnosis.com/medical/bicuculline.htm

http://wrongdiagnosis.pubs.righthealth.com/topic/Bicuculline?as=clinks&ac=1425&afc=2168586466&p=cl1

http://www.statemaster.com/encyclopedia/Bicuculline

Bacteriocin

Definition of Bacteriocin

It is a form of protein that is produced by bacteria. It inhibits or kills the growth of other kinds of bacteria. It is actually a proteinaceous toxin that is created as a tiny molecule by bacteria. It reduces the growth of bacterial strains that are similar or closely associated. The toxin is regarded to be an antibiotic of narrow spectrum and it is produced by a wide array of bacteria.

History of Bacteriocin

This toxin was first discovered in 1925 by Mr. A. Gratia and his assistants. Gratia was looking for methods to destroy bacteria. The search led him to the discovery of Bacteriocin as well as the finding of bacteriophage and the developing of antibiotics.

Classification of Bacteriocin

This toxin can be arranged into separate categories depending on factors like :

  • Strain producing
  • Mechanism of destruction
  • Common Resistance Mechanisms
  • Genetics
  • Chemistry
  • Molecular weight
  • Method of production

There are various large types of Bacteriocin that are associated only phenomenologically. These include Bacteriocins from

  • Gram-positive bacteria
  • Microcins
  • Colicins (also known as “Colicines” or “Coli Killers”)
  • Archaea

Colicins are bacteriocins obtained from E. Coli bacteria and have been under medical study for a long period of time. When A. Gratia discovered bacteriocins for the first time, he named them as Colicine as it helped him kill the E. Coli bacteria.

According to another type of classification, bacteriocins are differentiated into three categories. These are

Class I Bacteriocins

These are tiny peptide inhibitors and involve Nisin as well as other lantibiotics.

Class II Bacteriocins

These are miniscule proteins that are resistant to heat. The Class II comprises of the largest subgroup of Bacteriocins. These can be used in medical applications as well as food preservation due to their solid antilisterial activity.

Class III Bacteriocins

These are huge protein bacteriocins that react sharply to heat.

Structure of Bacteriocin

The structure of this toxin usually resembles the shape of a protein or peptide. It consists of amino acid chains of different size.

Other Names for Bacteriocin

These protein types are known by a host of different names like

  • Aureocin
  • Agrocin
  • Alveicin
  • Lactococin
  • Lacticin
  • Leucoccin
  • Carnocin
  • Colicin
  • Thuricin 17
  • Trifolitoxin
  • Curvaticin
  • Divercin
  • Enterocin
  • Vibriocin
  • Warnerin
  • Enterolysin
  • Epidermin
  • Sakacin
  • Subtilin
  • Sulfolobicin
  • Erwiniocin
  • Glycinecin
  • Halocin
  • Nisin
  • Pediocin
  • Plantaricin
  • Mesentericin

Production of Bacteriocin

Production of this toxin is motivated by Mitomycin C, Heat Shock and UV Radiation. The production is demonstrated by thrusting vaccinated multiple strains on more than one isolated nutrient agar Petri dishes that are covered for one whole day at 30 degree Centigrade. Then each plate is covered with one of the available strains. The dishes are again covered for another day at 30 degree Centigrade.

Uses of Bacteriocin

These proteins are composed of non-pathogenic bacteria which usually settle inside the human body. This is the reason why these proteins are of great use in medicine. When antibiotics lead to the removal of these harmless bacteria as a side effect, pathogenic bacteria can attack the body and give rise to ailments.

These proteins are also considered to be a possible treatment for cancer. It has shown promise as an agent for diagnosis of cancer. However, whether this protein can be used for treatment is dependent on experiments. The doubt about therapeutic capabilities of this protein remains due to lack of clarity about the Bacteriocin mechanism of action and the supposition that they are incapable of destroying tumor cells in mammals.

References:

http://en.wikipedia.org/wiki/Bacteriocin

http://www.wisegeek.com/what-is-bacteriocin.htm

Sulfurous Acid

Definition of Sulfurous Acid

Sulfurous Acid is a chemical compound which has a formula H2SO3, and is a weak and unstable acid, formed when sulfur dioxide dissolves in water. The facts that sulfur dioxide actually exists in solution, cannot be said surely, but the molecules of this substance has been detected in the gas phase. It is a reducing, as well as a bleaching agent.  The sulfurous acid compound is only formed in the aqueous solution, and is therefore not isolated in its pure state.

Lewis Structure of Sulfurous Acid

The structure of sulfurous acid is as follows. It shows the bond between sulfur, carbon and oxygen.

Picture of Sulfurous acid
Structure of Sulfurous Acid

Picture 1 – Structure of Sulfurous Acid

Source – www.elmhurst.edu

Formula of Sulfurous Acid

The chemical formula of Sulfurous Acid is H2SO3.  This is the Sulfurous Acid Chemical formula, since it atoms of hydrogen, oxygen and carbon are joined by a strong chemical bond. This is also the molecular formula for sulfurous acid, since it demonstrates that one molecule of sulfurous acid contains two atoms of hydrogen, one atom of sulfur and three atoms of oxygen.

Physical Properties of Sulfurous Acid

Sulfurous acid is also known as sulfur dioxide solution. It is not an organic acid. It is a clear and colorless solution.

Physical State of Sulfurous Acid

In the normal physical state, Sulfurous acid is a colorless liquid. It is appreciably soluble in water, and ignites automatically at a particular temperature. It is a generally stable acid, and is not compatible with strong bases.

Boiling Point of Sulfurous Acid

The boiling point of sulfurous acid is -60 °C or 213 k.

Odor of Sulfurous Acid

Sulfurous acid has a sort of sulfurous odor.

Vapor Pressure of Sulfurous Acid

Its vapor pressure is 1740 kPa at about 21 °C.

Weight of Sulfurous Acid

The formula weight of this acid is 82.07 amu (atomic mass units).

Density of Sulfurous Acid

The Density of sulfurous acid is 1.03 g/cm3, or 1.03 X 103 kg/m3.

Acidity of Sulfurous Acid

The acidity of sulfurous acid is 1.5 on the pH scale. It is not a very weak acid, but not a strong acid as well.

Sulfurous Acid – Strong or Weak

Sulfurous acid is a weak and dibasic acid, and it corresponds to the +4 oxidation state of sulfur. This acid id known to form only in the dilute aqueous solutions, and does not occur in other state. When this acid is exposed to atmosphere, it is transformed to the strong sulfuric acid. This acid is basically formed due to the incomplete disassociation of strong sulfuric acid in the aqueous solution.

Decomposition of Sulfurous Acid

Sulfurous acid is thermodynamically unstable. It decomposes and disassociates into its chemical constituents. This acid also decomposes as soon as it is formed. The decomposition reaction of sulfurous acid is:

H2SO(aq)—–> H2O(l) + SO2(g)

Equation of Sulfurous Acid

Since sulfurous acid is a weak acid, it changes to sulfuric acid on exposure to atmosphere. The Sulfurous acid equation is as follows:

2H2SO3 + O2 —–> 2H2SO4

Uses of Sulfurous Acid

Sulfurous acid is a very strong reducing agent. It also acts as a bleaching agent since it has some bleaching properties. There are certain substances that are injured by chlorine. These substances are bleached when they are exposed to sulfurous acid.

Effects of Sulfurous Acid

This acid generally does not exist independently, except for aqueous solutions. Therefore it is not harmful in normal circumstances, since it does not exist independently. But it is converted to sulfuric acid on exposure to atmosphere, and this acid had many harmful effects. This sulfuric acid combines with rain to form the harmful acid rain. Acid rain is not only harmful for life, but for plants as well.

References:

http://en.wikipedia.org/wiki/Sulfurous_acid

http://www.utdallas.edu/~parr/chm1341/13410705.html

http://www.economicexpert.com/a/Sulfurous:acid.html

http://msds.chem.ox.ac.uk/SU/sulfurous_acid.html

http://www.cartage.org.lb/en/themes/sciences/chemistry/inorganicchemistry/chemicslformula/Typesequation/Typesequation.htm

Biopolymers

Rising concern about escalating price of fossil fuel and their impact on environment has made it necessary to search for substitutes for petrochemical plastics. Biploymers are one of the alternatives of fossil fuels.

What is a Biopolymer?

It is a polymer that is developed from living beings. It is a biodegradable chemical compound that is regarded as the most organic compound in the ecosphere. The name “Biopolymer” indicates that it is a bio-degradable polymer.

History of Biopolymers

This polymer has been present on earth for billions of years. It is older than synthetic polymers such as plastics.

Examples of Biopolymers

Some Biopolymer examples are

  • Proteins
  • Carbohydrates
  • DNA
  • RNA
  • Lipids
  • Nucleic acids
  • Peptides
  • Polysaccharides (such as glycogen, starch and cellulose)
biopolymer photo

Picture 1: Biopolymer image
Source: dacct.com


All these biopolymers account for a greater part of the human body as well as the ecosphere. The DNA biopolymer is the most important for humans. The entire body structure as well as genetic behaviors that pass from parents to children is based on it. Both DNA and RNA are composed of nucleic acids that alternate in definite patterns to encode huge amount of genetic data.

The most common biopolymer is Cellulose. It is also the most abundant organic compound on this planet. It comprises of 33% of all plant component on Earth.

Classification of Biopolymers

There are four main types of Biopolymers. These are

Sugar based Biopolymers

Starch or Sucrose is used as input for manufacturing Polyhydroxibutyrate. Sugar based polymers can be produced by blowing, injection, vacuum forming and extrusion. Lactic acid polymers (Polyactides) are created from milk sugar (lactose) that is extracted from potatoes, maize, wheat and sugar beet. Polyactides are resistant to water and can be manufactured by methods like vacuum forming, blowing and injection molding.

Starch based Biopolymers

Starch acts as a natural polymer and can be obtained from wheat, tapioca, maize and potatoes. The material is stored in tissues of plants as one way carbohydrates. It is composed of glucose and can be obtained by melting starch. This polymer is not present in animal tissues. It can be found in vegetables like tapioca, corn, wheat and potatoes.

Biopolymers based on Synthetic Materials

Synthetic compounds that are obtained from petroleum can also be used for making biodegradable polymers such as aliphatic aromatic copolyesters. Though these polymers are manufactured from synthetic components, they are completely compostable and bio-degradable.

Cellulose based Biopolymers

These are used for packing cigarettes, CDS and confectionary. This polymer is composed of glucose and is the primary constituent of plant cellular walls. It is obtained from natural resources like cotton, wood, wheat and corn.

The production of biopolymer may be done either from animal products or agricultural plants.

Types of Biopolymers

There are primarily two types of Biopolymers, one that is obtained from living organisms and another that is produced from renewable resources but require polymerization. Those created by living beings include proteins and carbohydrates.

Structure of Biopolymers

Unlike synthetic polymers, Biopolymers have a well-marked structure. These polymers have a uniformly distributed set of molecular mass and appear as a long chain of worms or a curled up string ball under a microscope. This type of polymer is differentiated based on their chemical structure.

Uses of Biopolymers

These polymers play an essential role in nature. They are extremely useful in performing functions like storage of energy, preservation and transmittance of genetic information and cellular construction.

  • Sugar based polymers, such as Polyactides, naturally degenerate in the human body without producing any harmful side effects. This is the reason why they are used for medical purposes. Polyactides are commonly used as surgical implants.
  • Starch based biopolymers can be used for creating conventional plastic by extruding and injection molding.
  • Biopolymers based on synthetic are used to manufacture substrate mats.
  • Cellulose based Biopolymers, such as cellophane, are used as a packaging material.
  • These chemical compounds can be used to make thin wrapping films, food trays and pellets for sending fragile goods by shipping.

Environmental Benefits of Biopolymers

Some of the environmental benefits of this polymer are:

  • These polymers are carbon neutral and can always be renewed. These are sustainable as they are composed of living materials.
  • These polymers can reduce carbon dioxide levels in the atmosphere and also decrease carbon emissions. This happens because bio-degradation of these chemical compounds can release carbon dioxide that can be reabsorbed by crops grown as a substitute in their place.
  • It is also compostable which means there is less chance of environmental pollution from this compound. This is one of the primary advantages of this chemical compound. However, the materials composed from this compound are not compostable.
  • These chemical compounds reduce dependency on non-renewable fossil fuels. These are easily biodegradable and can decrease air pollution. It greatly reduces the harmful effect of plastic use on the environment. Long term use of biopolymer use will limit the use of fossil fuel.

Difference between Polymer and Biopolymer

Biopolymers and Bioplastics are often confused for one another. However, these are different materials. Biopolymers are polymers that can be found in or manufactured by, living organisms. These also involve polymers that are obtained from renewable resources that can be used to manufacture Bioplastics by polymerization.

Bioplastics are the plastics that are created by using biodegradable polymers. The great automobile manufacturer Henry Ford devised a way of manufacturing bioplastic car sections from soybeans back in the middle of the 20th century. However, the beginning of the Second World War stopped production of bioplastic cars. It is only recently that bioplastic cars have made a comeback due to development of new manufacturing techniques through biotechnology.

References:

http://en.wikipedia.org/wiki/Biopolymer

http://www.o2.org/ideas/cases/biopolymers.html

http://www.biobasics.gc.ca/english/View.asp?x=790#top

http://www.wyatt.de/index.php?id=biopolymer-characterization

http://www.designinsite.dk/htmsider/md150.htm

http://www.sda-uk.org/materials/biopolymers/Biopolymers.htm

http://www.wisegeek.com/what-are-biopolymers.htm

Tetrodotoxin

Though some animals of nature may seem very beautiful, but in reality they can be very dangerous. The animals have toxins which once injected may prove to be very lethal. Tetrodotoxin is one such poison found in various animals. Read on to know more about Tetrodotoxin.

Tetrodotoxin is a poison which is found in Puffer fish and several other animals such as blue-ringed octopus, harlequin frogs etc. It is a virulent poison which is considered to be 10 times more venomous than cyanide and is one of the most potent toxins present in nature. It is abbreviated as TTX and is also called Zombie powder by those who follow Vodou. Although the toxin is present in Puffer fish and the animals mentioned above, yet it is actually produced by a certain kind of symbiotic bacteria as well as some others which reside within these animals.

History

The first case of poisoning of Tetrodotoxin comes from the logs of Captain James Cook in 1774 who observed his crew eating puffer fish and feeding the remains to pigs. Soon after, the crew began to feel numbness and respiratory difficulties while the pigs died the very next morning. The name of the toxin was given in 1909 by Dr Yoshizumi Tahara, a scientist from Japan.

Structure

The molecule comprises of a +vely charged Guanidinium group which is made up of three atoms of nitrogen and a Pyrimidine ring along with additional fused ring systems.

Photos Of Tetrodotoxin


Picture 1 – Tetrodotoxin
Source – fda.gov

Poisoning

The organ of Puffer fish contains certain amount of Tetrodotoxin which can very well paralyze the diaphragm and result in death because of respiratory breakdown. The toxicity, however depends on species, seasons, geographical locations etc. The near lethal doses of the toxin can leave an individual in a state of near death for several days.

Lethal Dose

According to the material safety data sheet the oral median lethal dose for an animal (mice) is 334 μg per kg while a single milligram or sometimes even less of TTX is enough to kill an adult human being.

Symptoms And Effects

There are several symptoms and effects of Tetrodotoxin. After a person eats a poisonous Puffer fish, the first symptom is a bit of numbness felt on the lips and tongue within 20 minutes to 3 hours. It is followed by escalating paresthesia in the face and extremities which may be followed by some feelings of lightness. The effects are in form of headache, diarrhea, epigastria pain and vomiting. Sometimes the person can feel difficulty to walk. The second stage is increasing paralysis where the victim is unable to move and experience difficulty in breathing. Speech too is affected and the victim exhibits signs of dyspnea, hypotension and cyanosis. Within 4 to 6 hours the victim dies.

Mode Of Action

Tetrodotoxin blocks sodium ion channel whose flow is very important for conduction of nerve impulses in excitable nerve fibers and along axon. Since Tetrodotoxin is larger than sodium it blocks its flow. The toxin affects the central nervous system to prevent the dissemination of nerve impulses.

Pics Of Tetrodotoxin

Picture 2 – Tetrodotoxin
Source – thieme-connect.com

Treatment

No antidote for the poison has been developed. Due to this, cure of tetrodotoxin has to be carried out in natural ways. It is important to make the person vomit and empty his stomach. One can also feed the victim activated charcoal to unite the poison and take standard life support measures to keep the victim alive until the effects of the poison are gone. One also can inject a person with intravenous fluids along with alpha adrenergic agonists to fight hypotension.

Research

The toxin is extensively used in the research of sodium ion channels. Since it specifically binds the sodium channel it provides more information regarding the secondary and the tertiary structure and nature of the channels. Research is being carried out as to whether the toxin can be used as an anesthetic or not.

Solubility

The toxin is  insoluble in organic solvents where as solubility is limited in ethanol and ether. However, it is soluble in sulfuric and dilute acetic acid.

Medical Use

There are some medical uses of the toxin too. Tetrodotoxin has proved handy in the treatment of intense pain, cardiac arrhythmias, terminal cancers, migraines etc.

As aforesaid, this toxin can be found in many animals that are consumed by humans. It is better to avoid delicacies prepared from such animals or limit their intake to a minimum for safekeeping of your health.

Reference:

http://en.wikipedia.org/wiki/Tetrodotoxin

http://www.psych.ndsu.nodak.edu/nawrot/Courses/465Projects06/Tetrodotoxin/structure.html

http://www.websters-online-dictionary.org/definitions/Tetrodotoxin?cx=partner-pub-0939450753529744%3Av0qd01-tdlq&cof=FORID%3A9&ie=UTF-8&q=Tetrodotoxin&sa=Search#922

http://www.chm.bris.ac.uk/motm/ttx/ttx.htm

http://www.cbwinfo.com/Biological/Toxins/TTX.html

http://www.ch.ic.ac.uk/local/projects/quek/research.htm

Ultimet

Ultimet is a Cobalt alloy and is widely used in factories and industries. Haynes International, Inc produces this “high performance alloy”.

Composition of Ultimet

It is a metal alloy that consists of various alloying elements. The elements are used in the following proportions to produce this alloy:

  • Cobalt (as balance) – 54%
  • Chromium- 26%
  • Nickel- 9%
  • Molybdenum- 5%
  • Iron- 3%
  • Tungsten- 2%
  • Manganese- 0.8%
  • Silicon-0.3%
  • Nitrogen- 0.08%
  • Carbon-0.06%

Properties of Ultimet

Following are some of the physical properties of this metal alloy:

  • The density of this metal alloy is 8.47 g/cm3.
  • It melts in a temperature somewhere between 2430-2470 °F.
Ultimet Picture

Applications of Ultimet

This alloy is widely used for various industrial purposes. Following are some of the uses of Ultimet:

  • This alloy has high corrosion resistance abilities. In fact its resisting abilities are comparable to that of the Hastelloy alloys. Hastelloy is the trademark name for 22 highly corrosion resistant alloys, all of which are produced by the Haynes International, Inc.
  • Ultimet is also a very efficient wear and gall resistant material.
  • The electrogalvanising rolls of this alloy are successfully used in the production of galvanized steel. This steel is used for automobiles In Europe and the Far East.
  • It is also commonly used in agitators, blenders, dies, fan blades, nozzles, glass plungers, valve parts and screw conveyors.

Material Safety Data Sheet (MSDS)s of Ultimet

This material can be harmful for humans in the cases mentioned bellow:

Inhalation

If a person inhales the fume or dust of this alloy while welding, he may experience reduced lung function, nasal irritation, breathing difficulty etc. The victim should immediately seek medical advice. Artificial respiration must be given to the victim in case breathing has stopped.

Ingestion

If the metal is ingested by accident, the victim should take medical assistance. Sometimes it is advisable to drink 1-2 glasses of water and dilute the material.

Eyes

Direct eye contact with this material may cause eye irritation. The affected eye should be immediately washed with plenty of clean water. It is not advisable to rub or keep the eyes closed. Medical advice should be taken if the irritation continues.

Skin

Ultimet dust or fume may cause skin irritation. But the affected skin can be treated by regular first aid. The affected area should be washed properly with soap. The victim should seek medical assistance in case the irritation continues or blisters appear.

Ultimet is a highly useful alloy and it is the answer for various welding, corrosion and other industrial needs.

References:

http://www.vegasfastener.com/Haynes-Ultimet-1233.php

http://www.haynesintl.com/UltimetAlloy/ULTIMETAlloyPF.htm

http://www.wolframalpha.com/input/?i=ultimet

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