Monday, June 7, 2010

Wilson's Disease: Inherited Disease of Toxic Copper Accumulation

Due to a failure of copper excretion in the liver, toxic levels of copper build up and cause damage to the liver and central nervous system.

http://www.chemgapedia.de/vsengine/media/vsc/de/ch/4/cm/komplexe/bilder/kf2.jpg
Wilson's disease or Wilson disease or hepatolenticular degeneration is an inherited disorder involving toxic accumulation of copper in the liver and the central nervous system (CNS). Accumulation in the CNS usually occurs in the sites of the basal ganglia and globus pallidus. These symptoms are all due to a failure of copper excretion by the liver.

Genetics of Wilson Disease

The incidence of Wilson's disease is 3 in 100 000. It is an autosomal recessive disorder where there is a mutation on the ATP7B gene, an ATPase, which is a copper transporter on chromosome 13. There are many known mutations but the most common is HIS1069GLU which is most common in the European population.

Clinical Features of Wilson's Disease

Children can present with liver disease and this can be expressed as fulminant liver failure, hepatitis, or cirrhosis. In young adults, one can see CNS signs such as tremor, dysarthria, dysphagia, dyskinesias, dystonias, dementia, and parkinsonism. They can also develop affective features such as depression or mania, labile emotions, fluctuating libido and personality changes. With regards to their cognition, memory can decrease and problem solving can become increasingly difficult. A famous sign of Wilson disease is the presence of Kayser-Fleischer rings, which are copper deposits in the iris.

Tests and Diagnosis of Wilson Disease

In patients with Wilson's disease, serum copper and serum caeruoplasmin are usually decreased. One can test with a 24 hour urinary copper excretion. Molecular testing is available to look for mutations in the ATP7B gene and to make a definitive diagnosis. Magnetic resonance imaging (MRI) is often used to look for signs of basal ganglia degeneration.

Management and Treatment of Wilson's Disease

Patients with Wilson's disease are on lifelong penicillinamine.

Penicillinamine is a metabolite of peniciliin but it has no antibiotic properties. It is a chelating agent that binds to accumulated copper and is then eliminated through the urine. Some possible side effects of penicillinamine are nausea, rash, low white cell count, anemia, thrombocytopenia, and haematuria.
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Liver

is the only internal human organ which can regenerate



What is the Liver?
The liver is the largest glandular organ of the body. It weighs about 3 lb (1.36 kg). It is reddish brown in color and is divided into four lobes of unequal size and shape. The liver lies on the right side of the abdominal cavity beneath the diaphragm. Blood is carried to the liver via two large vessels called the hepatic artery and the portal vein. The heptic artery carries oxygen-rich blood from the aorta (a major vessel in the heart). The portal vein carries blood containing digested food from the small intestine. These blood vessels subdivide in the liver repeatedly, terminating in very small capillaries. Each capillary leads to a lobule. Liver tissue is composed of thousands of lobules, and each lobule is made up of hepatic cells, the basic metabolic cells of the liver.
What is its major function?
The liver has many functions. 

Some of the functions are: 

-to produce substances that break down fats,
-convert glucose to glycogen,
-produce urea (the main substance of urine),
-make certain amino acids (the building blocks of proteins), 
-filter harmful substances from the blood (such as alcohol), 
-storage of vitamins and minerals (vitamins A, D, K and B12) and 
-maintain a proper level or glucose in the blood. 
-The liver is also responsible for producing cholesterol. It produces about 80% of the            cholesterol in your body.

Diseases of the Liver
Several diseases states can affect the liver. Some of the diseases are Wilson's Disease, hepatitis (an inflammation of the liver), liver cancer, and cirrhosis (a chronic inflammation that progresses ultimately to organ failure). Alcohol alters the metabolism of the liver, which can have overall detrimental effects if alcohol is taken over long periods of time.
Hemochromatosis can cause liver problems.

Medications that negatively effect the liver

Medications have side effects that may harm your liver. Some of the medications that can damage your liver are: serzone, anti-cancer drugs (tagfur, MTX, and cytoxan), and medications used to treat diabetes.

Serzone is a prescription drug manufactured by Bristol-Myers Squibb for the treatment of depression.

The possible side effects of Serzone® are: agitation, dizziness, clumsiness or unsteadiness, difficulty concentrating, memory problems, confusion, severe nausea, gastroenteritis, abdominal pain, unusually dark urine, difficult or frequent urination, fainting, skin rash or hives yellowing of the skin or whites of the eyes (jaundice) or a prolonged loss of weight or loss of appetite.
If you or a family member have suffered serious side effects or a fatal injury after taking Serzone®, you or the family member may be eligible to file a claim against the manufacturer. You should contact an attorney that specializes in class action lawsuits immediately.
To help prevent liver damage, let your doctor know about your liver condition when being treated for other conditions. Medications come in many forms and it is best to find out what is in them and what it can do to your liver.
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Instrument landing system

http://www.niquette.com/books/chapsky/skypix/ILS.gif
An instrument landing system (ILS) is a ground-based instrument approach system that provides precision guidance to an aircraft approaching and landing on a runway, using a combination of radio signals and, in many cases, high-intensity lighting arrays to enable a safe landing during instrument meteorological conditions (IMC), such as low ceilings or reduced visibility due to fog, rain, or blowing snow.

Instrument approach procedure charts (or approach plates) are published for each ILS approach, providing pilots with the needed information to fly an ILS approach during instrument flight rules (IFR) operations, including the radio frequencies used by the ILS components or navaids and the minimum visibility requirements prescribed for the specific approach.

Radio-navigation aids must keep a certain degree of accuracy (set by international standards of CAST/ICAO); to assure this is the case, flight inspection organizations periodically check critical parameters with properly equipped aircraft to calibrate and certify ILS precision.
Many airports do not have ILS.
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Saturday, June 5, 2010

Refuse-derived fuel (RDF)

Refuse-derived fuel (RDF) or solid recovered fuel/ specified recovered fuel (SRF) is a fuel produced by shredding and dehydrating municipal solid waste (MSW) in a converter or steam pressure treating in an autoclave.

RDF consists largely of organic components of municipal waste such as plastics and biodegradable waste

RDF processing facilities are normally located near a source of MSW and, while an optional combustion facility is normally close to the processing facility, it may also be located at a remote location.

SRF can be distinguished from RDF in the fact that it is produced to reach a standard such as CEN/343 ANAS.

 

Strengths and Weaknesses of Refuse Derived Fuel Units

Strengths
Weaknesses
Integrated – offers front end recycling activity, with energy recovery of balance
Requires secure markets for fuel e.g. an industrial estate
Organic fraction can be recycled aerobically (composting) or anaerobically (AD)
RDF is in competition with other fuels
If densified, RDF can be stored for extended periods (coarse RDF is more suited for direct on-site use and cannot be stored)
Processing involves high electrical power consumption and maintenance
RDF can be processed to half the calorific value of coal
Poor UK operating experience of older RDF plants including reliability and air pollution control
Lower level of heavy metals in the RDF
Fuel production space required
RDF can be co-fired with other fuels in a variety of industrial boilers
RDF can cause more damage to boilers and pipework than other fuels

Thursday, June 3, 2010

Preservatives

Various preserved foodsImage via Wikipedia
All food products except for the one growing in your kitchen garden has food preservatives in them. Every manufacturer adds food preservative to the food during processing. The purpose is generally to avoid spoilage during the transportation time.

Food is so important for the survival, so food preservation is one of the oldest technologies used by human beings to avoid its spoilage. Different ways and means have been found and improved for the purpose. Boiling, freezing & refrigeration, pasteurizing, dehydrating, pickling are the traditional few. Sugar and salt are also often used as preservatives food. Nuclear radiation is also being used now as food preservatives. Modified packaging techniques like vacuum packing and hypobaric packing also work as food preservatives.

Food Preservation is basically done for three reasons
  • To preserve the natural characteristics of food
  • To preserve the appearance of food
  • To increase the shelf value of food for storage.

Natural Food Preservatives

In the category of natural food preservatives comes the salt, sugar, alcohol, vinegar etc. These are the traditional preservatives in food that are also used at home while making pickles, jams and juices etc. Also the freezing, boiling, smoking, salting are considered to be the natural ways of preserving food. Coffee powder and soup are dehydrated and freeze-dried for preservation. In this section the citrus food preservatives like citrus acid and ascorbic acid work on enzymes and disrupt their metabolism leading to the preservation.

Sugar and salt are the earliest natural food preservatives that very efficiently drops the growth of bacteria in food. To preserve meat and fish, salt is still used as a natural food preservative.

Chemical Food Preservatives

Chemical food preservatives are also being used for quite some time now. They seem to be the best and the most effective for a longer shelf life and are generally fool proof for the preservation purpose. Examples of chemical food preservatives are:

  • Benzoates (such as sodium benzoate, benzoic acid)
  • Nitrites (such as sodium nitrite)
  • Sulphites (such as sulphur dioxide)
  • Sorbates (such as sodium sorbate, potassium sorbate


Antioxidants are also the chemical food preservatives that act as free radical scavengers. In this category of preservatives in food comes the vitamin C, BHA (butylated hydroxyanisole), bacterial growth inhibitors like sodium nitrite, sulfur dioxide and benzoic acid.

Then there is ethanol that is a one of the chemical preservatives in food, wine and food stored in brandy.
Unlike natural food preservatives some of the chemical food preservatives are harmful. Sulfur dioxide and nitrites are the examples. Sulfur dioxide causes irritation in bronchial tubes and nitrites are carcinogenic.

Artificial Preservatives

Artificial preservatives are the chemical substances that stops of delayed the growth of bacteria, spoilage and its discoloration. These artificial preservatives can be added to the food or sprayed on the food.

Types of Artificial Preservatives Food

  • Antimicrobial agents
  • Antioxidants
  • Chelating agent

In antimicrobial comes the Benzoates, Sodium benzoate, Sorbates and Nitrites.
Antioxidants include the Sulfites, Vitamin E, Vitamin C and Butylated hydroxytoluene (BHT)
Chelating agent has the Disodium ethylenediaminetetraacetic acid (EDTA), Polyphosphates and Citric acid

Harmful Food Preservatives

Although preservatives food additives are used to keep the food fresh and to stop the bacterial growth. But still there are certain preservatives in food that are harmful if taken in more than the prescribed limits.

Certain harmful food preservatives are

Benzoates

This group of chemical food preservative has been banned in Russia because of its role in triggering allergies, asthma and skin rashes. It is also considered to cause the brain damage. This food preservative is used in fruit juices, tea, coffee etc.

Butylates

This chemical food preservative is expected to cause high blood pressure and cholestrol level. This can affect the kidney and live function. It is found in butter, vegetable oils and margarine.

BHA (butylated hydroxyanisole)

BHA is expected to cause the live diseases and cancer
. This food preservative is used to preserve the fresh pork and pork sausages, potato chips, instant teas, cake mixes and many more.

Caramel

Caramel is the coloring agent that causes the vitamin B6 deficiencies, genetic effects and cancer. It is found in candies, bread, brown colored food and frozen pizza.

In addition to this there are many other harmful food preservatives. These are Bromates, Caffeine, Carrageenan, Chlorines, Coal Tar AZO Dies, Gallates, Glutamates, Mono- and Di-glycerides, Nitrates/Nitrites, Saccharin, Sodium Erythrobate, Sulphites and Tannin

Preservatives Food Additives

All of these chemicals act as either antimicrobials or antioxidants or both. They either inhibit the activity of or kill the bacteria, molds, insects and other microorganisms. Antimicrobials, prevent the growth of molds, yeasts and bacteria and antioxidants keep foods from becoming rancid or developing black spots. They suppress the reaction when foods comes in contact with oxygen, heat, and some metals. They also prevent the loss of some essential amino acids some vitamins
.

Some common preservatives and their primary activity
Chemical Affected
Organism(s)
Action

Use in Foods
Sulfites
Insects & Microorganisms
Antioxidant

Dried Fruits, Wine, Juice
Sodium Nitrite
Clostridia
Antimicrobial

Cured Meats
Propionic Acid
Molds
Antimicrobial

Bread, Cakes, Cheeses
Sorbic Acid
Molds
Antimicrobial

Cheeses, Cakes, Salad Dressing
Benzoic Acid
Yeasts & Molds
Antimicrobial

Soft Drinks, Ketchup, Salad Dressings

There are other antioxidants like Sodium Erythorbate, Erythorbic Acid, Sodium Diacetate, Sodium Succinate, Grape Seed Extract, Pine Bark Extract, Apple Extract Tea Proplyphenols, Succinic Acid and Ascorbic Acid and food preservatives like Parabens and Sodium Dehydro Acetate used frequently for preservation.
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Wednesday, June 2, 2010

Periodic Table

Group 1 2   3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Period
1 1
H

2
He
2 3
Li
4
Be

5
B
6
C
7
N
8
O
9
F
10
Ne
3 11
Na
12
Mg

13
Al
14
Si
15
P
16
S
17
Cl
18
Ar
4 19
K
20
Ca

21
Sc
22
Ti
23
V
24
Cr
25
Mn
26
Fe
27
Co
28
Ni
29
Cu
30
Zn
31
Ga
32
Ge
33
As
34
Se
35
Br
36
Kr
5 37
Rb
38
Sr

39
Y
40
Zr
41
Nb
42
Mo
43
Tc
44
Ru
45
Rh
46
Pd
47
Ag
48
Cd
49
In
50
Sn
51
Sb
52
Te
53
I
54
Xe
6 55
Cs
56
Ba
* 71
Lu
72
Hf
73
Ta
74
W
75
Re
76
Os
77
Ir
78
Pt
79
Au
80
Hg
81
Tl
82
Pb
83
Bi
84
Po
85
At
86
Rn
7 87
Fr
88
Ra
** 103
Lr
104
Rf
105
Db
106
Sg
107
Bh
108
Hs
109
Mt
110
Ds
111
Rg
112
Cn
113
Uut
114
Uuq
115
Uup
116
Uuh
117
Uus
118
Uuo
 
*Lanthanoids * 57
La
58
Ce
59
Pr
60
Nd
61
Pm
62
Sm
63
Eu
64
Gd
65
Tb
66
Dy
67
Ho
68
Er
69
Tm
70
Yb

**Actinoids ** 89
Ac
90
Th
91
Pa
92
U
93
Np
94
Pu
95
Am
96
Cm
97
Bk
98
Cf
99
Es
100
Fm
101
Md
102
No

 

Element 117 discovered?

A paper just published (5 April 2010) in Physical Review Letters by Yu. Ts. Oganessian and others claims the synthesis of a new element with atomic number 117. The abstract states "The discovery of a new chemical element with atomic number Z=117 is reported. The isotopes 293117 and 294117 were produced in fusion reactions between 48Ca and 249Bk. Decay chains involving eleven new nuclei were identified by means of the Dubna Gas Filled Recoil Separator. The measured decay properties show a strong rise of stability for heavier isotopes with Z>=111, validating the concept of the long sought island of enhanced stability for super-heavy nuclei.

Sunday, May 30, 2010

COD test and BOD test

http://img.alibaba.com/photo/11093024/Chemical_Oxygen_Demand_Test_Kit_COD_C_O_D_.jpg
Chemical oxygen demand (COD) is a measure of the capacity of water to consume oxygen during the decomposition of organic matter and the oxidation of inorganic chemicals such as ammonia and nitrite. COD measurements are commonly made on samples of waste waters or of natural waters contaminated by domestic or industrial wastes. Chemical oxygen demand is measured as a standardized laboratory assay in which a closed water sample is incubated with a strong chemical oxidant under specific conditions of temperature and for a particular period of time. A commonly used oxidant in COD assays is potassium dichromate (K2Cr2O7) which is used in combination with boiling sulfuric acid (H2SO4). Because this chemical oxidant is not specific to oxygen-consuming chemicals that are organic or inorganic, both of these sources of oxygen demand are measured in a COD assay.
Chemical oxygen demand is related to biochemical oxygen demand (BOD), another standard test for assaying the oxygen-demanding strength of waste waters. However, biochemicaloxygen demand only measures the amount of oxygen consumed by microbial oxidation and is most relevant to waters rich in organic matter. It is important to understand that COD and BOD do not necessarily measure the same types of oxygen consumption. For example, COD does not measure the oxygen-consuming potential associated with certain dissolved organic compounds such as acetate. However, acetate can be metabolized by microorganisms and would therefore be detected in an assay of BOD. In contrast, the oxygen-consuming potential of cellulose is not measured during a short-term BOD assay, but it is measured during a COD test.

biochemical oxygen demand (BOD)

(BOD)

The amount of oxygen taken up by microorganisms that decompose organic waste matter in water. It is therefore used as a measure of the amount of certain types of organic pollutant in water. BOD is calculated by keeping a sample of water containing a known amount of oxygen for five days at 20°C. The oxygen content is measured again after this time. A high BOD indicates the presence of a large number of microorganisms, which suggests a high level of pollution.