Harwood AP CHEM Project

Although synthetic polymers are widely used in medicine, in direct contact with blood, these polymers are still prone to initiate the formation of clots due to activation of platelets and other components of the blood coagulation system ([Aiping and Tian 2006]). It is well known that interactions between the surface of an artificial biomaterial and biological environment are the key factor to determine the biocompatibility

As defined by Park & Lakes (2007), a biomaterial is a material that replaces either a tissue within the body or a function of the body.

In the first generation of biomaterial development, individuals used materials in their local environments for replacing tissues that were lost to damage or disease.

The goal during the first generation of biomaterial development was the creation of materials that exhibited inert behaviour when placed in the body. Surgeons sought materials that provided (i) appropriate mechanical properties for the intended use, (ii) corrosion resistance, and (iii) an absence of injurious effects such as carcinogenicity, toxicity, allergy and inflammation.

with a limited income, most people will choose to take care of their own immediate needs before they address the needs of the planet.

Between 1977 and 2013, the overall cost associated with solar power dropped an amazing 99%

dropped 60% since the beginning of 2011

oy Safety Directive 2009/48/EC (TSD)

n 2006, they said that five chemicals — lead, methylmercury, arsenic, PCBs and toluene — should be considered toxic to the developing brain. The doctors did not conduct new studies on these substances, but now, based on a reading of new research, which has been exploding in recent years, they've added six more:• Manganese, a natural chemical found in drinking water in places like Bangladesh.• Fluoride, in high concentrations, which has caused problems in China, though the low levels added to American drinking water are presumed safe.• Chlorpyrifos, an insecticide used on golf courses and in agriculture among other places.• Dichlorodiphenyltrichloroethane (DDT), an insecticide banned in the U.S. in the 1970s, but still used in some countries.• Tetrachloroethylene (PERC), a solvent used in dry cleaning and metal degreasing.• Polybrominated diphenyl ethers (PBDE), also known as flame retardants and often found in furniture, electronics and clothing, including children's pajamas.

38-year-old Toxic Substances Control Act

Quinolones

Penicillins

Cephalosporins

Cocci are spherical cells, bacilli are rod-shaped. Bacteria of either shape that have thick cell walls are termed gram positive because of the way they take up the Gram stain. Those with thin cell walls are termed gram negative

Spirochaetes: corkscrew-shaped bacteria that fall into three species, all of which cause specific diseases

Rickettsia: bacteria from the Rickettsiaceae family, which can only live and survive inside other living cells

Conjugation: this is direct cell-to-cell contact between two cells through what is called a "conjugation tube". This tube allows for the transfer of genetic material (DNA, plasmids) to another cell so that it can integrate the resistance into its genome

when a cell dies the DNA that is left over can be absorbed by another cell near to it. When the cell dies, the bacterial wall breaks down and allows the material within to become accessible to other cells. When this material codes for genetic resistance to antibiotics, transfer occurs and the new cell is now resistant

Transduction: this occurs when genetic material is transferred from one cell to another through a bacteriophage. When bacteriophages infect cells and begin to proliferate in them, some bacterial DNA can sometimes be incorporated into the viral genome. When the bacteriophages are released and infect other cells, other cells can become resistant depending on what bacterial DNA was transferred

ncreased production of the antibiotic’s target enzyme so that there are too many of them and the antibiotics cannot inactivate them all

methylation -- a process by which enzymes add a small molecular tag to a particular location on a nucleotide -- a molecule that is the structural unit of RNA and DNA

facilitates the proper functioning of the bacterial ribosome -- a gigantic macromolecular machine that is responsible for making proteins that bacteria need to survive

antibiotics bind to the ribosome, disrupting its function and thereby killing the bacteria

chemically modify the antibiotic,  render it inactive through physical removal from the cell, or modify target site so that it is not recognized by the antibiotic.

Efflux pumps are high-affinity reverse transport systems located in the membrane that transport the antibiotic out of the cell.

A specific enzyme modifies the antibiotic in a way that it loses its activity. In the case of streptomycin, the antibiotic is chemically modified so that it will no longer bind to the ribosome to block protein synthesis.