Spectacles.

A modern pair of prescription reading glasses

Modern glasses are typically supported by pads on the bridge of the nose and by temple arms (sides) placed over the ears. CR-39 lenses are the most common plastic lenses due to their low weight, high scratch resistance, low dispersion, and low transparency to ultraviolet and infrared radiation.^{[citation needed]} Polycarbonate and Trivex lenses are the lightest and most shatter-resistant, making them the best for impact protection.^[1]

An unpopular aspect of glasses is their inconvenience. Though modern frames can be both lightweight and flexible, and new lens materials and optical coatings are resistant to breakage or scratching, glasses can still cause problems during rigorous sports. Visibility can be significantly reduced by becoming greasy, trapping vapour when eating hot food, swimming, walking in rain or rapid temperature changes (such as walking into a warm building from cold temperatures outside). Scraping, fracturing, or breakage of the lenses require time-consuming and costly professional repair.

Invention of eyeglasses

The 'Glasses Apostle' by Conrad von Soest (1403)

The first eyeglasses were made in Italy at about 1286, according to a sermon delivered on February 23, 1306 

The American scientist Benjamin Franklin, who suffered from both myopia and presbyopia, invented bifocals.

Woman wearing designer sunglasses.

Nobel Prize in Medicine and Physiology..1999

The Nobel Prize in Physiology or Medicine 1999

The Nobel Assembly at Karolinska Institutet in Stockholm, Sweden, has awarded the Nobel Prize in Physiology or Medicine for 1999 to Günter Blobel, for the discovery that "proteins have intrinsic signals that govern their transport and localization in the cell."

Günter Blobel, born in 1936, works at the Laboratory of Cell Biology, The Rockefeller University, New York

All living organisms are made up of cells. The eukaryotic cell contains a number of different types of organelles each of which is surrounded by a tightly sealed membrane. Future applications In the near future the entire human genome will be mapped. As a result one can also deduce the structure and topogenic signals of the proteins. This knowledge will increase our understanding of processes leading to disease and can be used to develop new therapeutic strategies. Already today drugs are produced in the form of proteins, e.g. insulin, growth hormone, erythropoetin and interferon. Usually bacteria are used for the production of the drug, but in order to be functional certain human proteins need to be synthesized in more complex cells, such as yeast cells. With the help of gene technology the genes of the desired proteins are provided with sequences coding for transport signals. The cells with the modified genes can then be efficiently used as protein factories. Increased knowledge about the process by which proteins are being directed to different parts of the cell also makes it possible to construct new drugs that are targeted to a particular organelle to correct a specific defect. The ability to reprogram cells in a specific way will also be important for future cell and gene therapy. Fig. 1. "The signal hypothesis". Proteins which are to be exported out of the cell are synthesized by ribosomes, associated with the endoplasmic reticulum. The genetic information from DNA is transferred via messenger RNA (mRNA). This information determines how the amino acids build up the proteins. First, a signal peptide is formed as a part of the protein. With the help of binding proteins, the signal peptide directs the ribosome to a channel in the endoplasmic reticulum. The growing protein chain penetrates the channel, the signal peptide is cleaved, and the completed protein is released into the lumen of the endoplasmic reticulum. The protein is subsequently transported out of the cell.

An Inventions that changed history,,The microwave

 

The Microwave Oven

The microwave oven, aka the "Popcorn and Hot Pockets Warmer," was a happy accident that came from, of all things, a weapons program.

Percy LeBaron Spencer was a self-educated engineer working on radar technology in the years following WWII. The technology in question was the sci-fi sounding magnetron, a piece of machinery capable of firing high intensity beams of radiation.

Above: a scientist, with robot.

Apparently, P.L.S., as some have called him, had a bit of a sweet tooth. Or a strange fetish. Either way, he had a candy bar in his pants while he was in the lab one day. The self-proclaimed engineer noticed that the chocolate bar had melted when he was working with the magnetron.

Spencer disregarded the simple idea that his body heat had melted the chocolate in favor of the less logical and therefore more scientific conclusion that invisible rays of radiation had "cooked it" somehow.

A sane man would stop at this point and realize these magical heat rays were landing just inches from his tender scrotum. Indeed, most of the military experts on hand probably dreamed of the battlefield applications of their new Dick-Melting Ray. But like all men of science, Spencer was fascinated and treated his discovery like a novelty. He used it to make eggs explode and pop kernels of corn ("Imagine, a future where a building full of workers in cubicles eat this all day!")

I proclaim myself to be awesome.

Spencer continued to experiment with the magnetron until he boxed it in and marketed it as a new way to cook food. The initial version of the microwave was roughly six feet tall, weighed in around 750 pounds and had to be cooled with water. But they got it down to size, and today we use it mostly to destroy random objects on YouTube.

Read more: 5 Accidental Inventions That Changed The World | Cracked.com http://www.cracked.com/article_17134_5-accidental-inventions-that-changed-world.html#ixzz1nuRNw5p1

2000..Nobel Prize in Medicine and Physiology.

Arvid Carlsson

Paul Greengard

Eric R. Kandel

The Nobel Prize in Physiology or Medicine 2000 was awarded jointly to Arvid Carlsson, Paul Greengard and Eric R. Kandel "for their discoveries concerning signal transduction in the nervous system".

A signal transduction in biology, is a cellular mechanism. It converts a stimulus into a specific cellular response.^[1] Signal transduction starts with a chemical or physical signal to a receptor, and ends with a change in cell function.

Receptors are in the cell membrane, with part of the receptor outside and part inside the cell.  The chemical signal binds to the outer portion of the receptor, changing its shape. This causes another signal inside the cell.  Some chemical messengers, such as testosterone, can pass through the cell membrane, and bind directly to receptors in the cytoplasm or nucleus.

Sometimes there is a cascade of signals within the cell. With each step of the cascade, the signal can be amplified, so a small signal can result in a large response.^[1] Eventually, the signal creates a change in the cell, either in the expression of the DNA in the nucleus or in the activity of enzymes in the cytoplasm.

Most often, ordered sequences of biochemical reactions inside the cell are involved. These are carried out by enzymes and linked through second messengers. So a "second messenger pathway" is produced. These things usually happen quickly, sometimes very quickly. They may last from milliseconds (in the case ofion flux) to days for gene expression.

The number of proteins and other molecules that take part increases during the process. So a 'signal cascade' develops and a relatively small stimulus may cause a large response.

In bacteria and other single-cell organisms, the transduction processes a cell has limits the number of ways it can respond to its environment. In multicellular organisms, lots of different signal transduction processes are used to coordinate the behavior of individual cells. By this means the function of the organism as a whole is organized. The more complex the organism, the more complex the repertoire of signal transduction processes the organism must possess.

Thus, sensing of both the external and internal environment at the cellular level, relies on signal transduction. Many disease processes such as diabetes, heart disease, autoimmunity and cancer arise from defects in signal transduction pathways. This highlights the critical importance of signal transduction to biology and medicine.^[2]

Four great discoveries.

Here’s a look at some discoveries that have changed the world. It’s nearly impossible to rank their importance though.

10. Australopithecus

Discovered by: An unknown South African

This is known to be the very fist human to exist. The skull was actually discovered by an unknown South African but further investigations were made by Raymond Dart. The fossil was recorded to be 3.7 million years ago. The brains of most species of Australopithecus were roughly 35% of the size of that of a modern human brain. Most species of Australopithecus were diminutive and gracile, usually standing no more than 1.2 and 1.4 m (approx. 4 to 4.5 feet) tall. Actually, the skull found by the South African native was thought be the skull of an ape, but after seeing that the spinal column was connected below the skull and not at the back, it was later concluded that it should be a skull of a man and not of an ape.

9. Penicillin

Discovered by: Alexander Fleming

Everybody knows the story – or at least, should – the brilliant yet notoriously absent-minded biologist Sir Alexander Fleming was researching a strain of bacteria called staphylococci. Upon returning from holiday one time in 1928, he noticed that one of the glass culture dishes he had accidentally left out had become contaminated with a fungus, and so threw it away. It wasn’t until later that he noticed that the staphylococcus bacteria seemed unable to grow in the area surrounding the fungal mould. Fleming didn’t even hold out much hope for his discovery: it wasn’t given much attention when he published his findings the following year, it was difficult to cultivate, and it was slow-acting – it wasn’t until 1945 after further research by several other scientists that penicillin was able to be produced on an industrial scale, changing the way doctors treated bacterial infections forever. Penicillin antibiotics are historically significant because they are the first drugs that were effective against many previously serious diseases such as syphilis and Staphylococcus infections.

8. Oxygen

Discovered by: Carl Wilhelm Scheele

Oxygen was first discovered by Swedish pharmacist Carl Wilhelm Scheele. He had discovered it by about 1772. Scheele called the gas “fire air” because it was the only known supporter of combustion, and wrote an account of this discovery in a manuscript he titled Treatise on Air and Fire, which he sent to his publisher in 1775. However, that document was not published until 1777. Meanwhille, oxygen was also identified by Joseph Priestly in 1774. Priestly discovered a colourless gas from heated red mercuric oxide. He found this gas was highly combustible. He called it dephlogisticated air. Priestly shared his discovery with the French scientist Antoine Lavoiser. Lavoiser was able to show oxygen supported animal life respiration.

7.Gravity

Discovered by: Isaac Newton

Isaac Newton, an English mathematician and physicist, is considered the greatest scientist of all time. Among his many discoveries, the most important is probably his law of universal gravitation. In 1664, Newton figured out that gravity is the force that draws objects toward each other. It explained why things fall down and why the planets orbit around the Sun.

6. Fingerprints

Discovered by: Evangelista Purkinje

The discovery that fingerprints are unique to each individual, are left behind on objects a person touches and can be lifted off those items is nothing short of miraculous. This discovery completely changed the way that law enforcement conducted investigations. In today’s modern age, Jack the Ripper would eventually be caught. Even though it was 1823 when Jan Evangelista Purkinje noticed how unique our fingerprints are, it took some time for law enforcement to figure out ways to use this knowledge. Today, this discovery is used in everyday police work.

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Nobel Prize in Medicine and Physiology..2001.

Leland H. Hartwell

Tim Hunt

Sir Paul M. Nurse

The Nobel Prize in Physiology or Medicine 2001 was awarded jointly to Leland H. Hartwell, Tim Hunt and Sir Paul M. Nurse "for their discoveries of key regulators of the cell cycle".

During that time, scientists and researchers all know that the cells in our bodies divide via cellular division but the mechanisms by which cellular division takes place was still unknown. They had no idea of specific proteins and signaling pathways responsible for the control and regulation of the cell cycle.

BASICS OF THE CELL CYCLE

Scientists estimate that for every gram of tissue in our body, there are one billion cells in it. Can you imagine how many cells compose a single human adult?

All the cells in our body came from a single cell, the fertilized egg cell. During our physical growth, the single fertilized egg cell divides continuously until groups of cells finally make up a tissue, until groups of tissues finally make up an organ, and until a group of organs finally make up a living human. All these cannot be done if our cells are not capable of cellular division.

Cell cycle or cell division cycle is the series of events that happens within the cell leading to its division. The cell cycle consists of several phases.

First is the G1 phase wherein the cell grows bigger until it finally reaches a critical size to enter the next phase, the S phase. During this phase, the genetic materials are duplicated and a copy of the chromosomes is formed. Next is the G2 phase wherein the cell checks if the duplication of the chromosomes is complete and there is further growth in the size of the cell. Next comes the M phase or mitosis phase wherein the cell divides to produce two identical daughter cells. Not all cells in the G1 phase automatically proceeds to the S phase, most of the cells exit the cell cycle and enters a resting phase or G0.

THE MEN BEHIND THE DISCOVERY

Leland Hartwell was born on the 30th of October 1939. During his childhood, he was an avid collector of bugs, butterflies, lizards, snakes and spiders. His major break was when he took the entrance exam on California Institute of Technology and he fell in love with the environment of real sciences. He graduated in 1961 and went to MIT for graduate school and he decided to work on gene regulation. He then became a professor in University of California and in the University of Washington.

Timothy Hunt was born on the 19th of February 1943 at Neston near Liverpool. He earned his B.A. in the University of Cambridge in 1964 and his Ph.D. also in the University of Cambridge.

Sir Paul Nurse was born on the 25 of January 1949. He earned his B.sc. in the University of Birmingham in 1970 and his Ph.D. in the University of East Anglia three years after. He became the Director-General of the Imperial Cancer Research Fund in London and became the head of the cell cycle laboratory.

THE SEMINAL DISCOVERY

Leland Hartwell was the pioneer of studying cell cycle using genetic methods. He made use of the yeast Saccharomyces cerevisiae as the subject of his experiments. In the year 1970, he tried to isolate individual gene that he thought were vital in the control of cell cycle. Successfully, he was able to isolate cells wherein the cell cycle regulator genes were dysfunctional. By the use of this same method, he was able to isolate more than a hundred genes that were directly involved in the control of cell cycle. He called these genes CDC gene which stands for cell division cycle genes. Among the hundreds of CDC genes that he was able to isolate, he noted CDC28 gene for it was observed to control the first step of the cell cycle, progression from the G1 phase. For this function he named the gene, “start.” He also introduced the concept of “checkpoints” wherein the cell cycle stops to check whether the DNA was perfectly duplicated.

The primary focus of the research of Sir Paul Nurse was to identify rate controlling steps in the cell cycle. He used a different type of yeast, Schizosaccharomyces pombe, as the subject of his experiments. In the 1970s, he discovered the CDC2 gene. With the help of his friend Pierre Thuriaux, they were able to prove that CDC2 gene was a rate limiting step controlling the onset of M phase.

On another study, he was trying to find a gene that also controls the transition from G1 to S phase similar to what Hartwell found. As a negative control for this experiment he used CDC2 mutants which he thought would block cell cycle progression from G2 to M phase. Surprisingly, his negative control always gave significant positive responses. He thought that his experiment was flawed and hypothesized that CDC2 was required twice in the cell cycle, first in the transition from G1 to S phase and from G2 to M phase. What he thought to be a faulty experiment turned out to be completely accurate.

Serendipitously, he found that CDC2 gene was also a rate limiting factor for the onset of S phase and M phase. In 1987, he also isolated the corresponding gene in humans which he called CDK1. This gene encodes for a protein that is a member of the cyclin dependent kinase CDK family.

In the early 1980s, Tim Hunt discovered the first cyclin molecule. He made use of another organism in his experiments, Arbacia, a sea urchin. In his experiments, he found strange bands with a basic behavior of strange disappearance which turned out to occur about 10 minutes before each cellular division. He called these bands cyclins because the levels of these proteins vary periodically during the cell cycle. Cyclins are proteins that are formed and then degraded during each cell cycle. This explains their varying levels.

The cyclins bind to the CDK molecules, thereby regulating the CDK activity and selecting the proteins to be phosphorylated. Cyclins have no catalytic activity and CDKs are inactive in the absence of its partner cyclin. When a CDK is activated by its partner cyclin, it activates or deactivates proteins that in turn control the entry of cells into the next phase of the cell cycle.

CLINICAL IMPLICATIONS

This discovery has great impact in cancer research. Chromosome alterations can be caused by faulty cell cycle control, defective S phase or uncontrolled cyclin-CDK activation. These chromosomal abnormalities are directly related to the development of cancer cells. Developments in the field of cancer diagnosis via this discovery include the fact that detecting increased levels of CDK-molecules and cyclins are sometimes found in human tumors like breast cancer and brain tumor. In the field of cancer therapy, inhibitors of CDK-molecules are now being tested for its effects in cancer treatment.