Nobel Prize in Chemistry 2016: Making the world's

                                     Smallest machines

Date:  October 5, 2016

Source:  Nobel Foundation

Summary:  The 2016 Nobel Prize in Chemistry is being awarded to Jean-Pierre Sauvage, Sir J. Fraser Stoddart, and Bernard L. Feringa "for the design and synthesis of molecular machines."

                                

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Chemistry 2016 to Jean-Pierre Sauvage of the University of Strasbourg, France; Sir J. Fraser Stoddart of Northwestern University, Evanston, IL, USA; and Bernard L. Feringa of the University of Groningen, the Netherlands "for the design and synthesis of molecular machines."

A tiny lift, artificial muscles and miniscule motors. The Nobel Prize in Chemistry 2016 is awarded to Jean-Pierre Sauvage, Sir J. Fraser Stoddart and Bernard L. Feringa for their design and production of molecular machines. They have developed molecules with controllable movements, which can perform a task when energy is added.

The development of computing demonstrates how the miniaturisation of technology can lead to a revolution. The 2016 Nobel Laureates in Chemistry have miniaturised machines and taken chemistry to a new dimension.

The first step towards a molecular machine was taken by Jean-Pierre Sauvage in 1983, when he succeeded in linking two ring-shaped molecules together to form a chain, called a catenane. Normally, molecules are joined by strong covalent bonds in which the atoms share electrons, but in the chain they were instead linked by a freer mechanical bond. For a machine to be able to perform a task it must consist of parts that can move relative to each other. The two interlocked rings fulfilled exactly this requirement.

The second step was taken by Fraser Stoddart in 1991, when he developed a rotaxane. He threaded a molecular ring onto a thin molecular axle and demonstrated that the ring was able to move along the axle. Among his developments based on rotaxanes are a molecular lift, a molecular muscle and a molecule-based computer chip.

Bernard Feringa was the first person to develop a molecular motor; in 1999 he got a molecular rotor blade to spin continually in the same direction. Using molecular motors, he has rotated a glass cylinder that is 10,000 times bigger than the motor and also designed a nanocar.

2016's Nobel Laureates in Chemistry have taken molecular systems out of equilibrium's stalemate and into energy-filled states in which their movements can be controlled. In terms of development, the molecular motor is at the same stage as the electric motor was in the 1830s, when scientists displayed various spinning cranks and wheels, unaware that they would lead to electric trains, washing machines, fans and food processors. Molecular machines will most likely be used in the development of things such as new materials, sensors and energy storage systems.

Jean-Pierre Sauvage, born 1944 in Paris, France. Ph.D. 1971 from the University of Strasbourg, France. Professor Emeritus at the University of Strasbourg and Director of Research Emeritus at the National Center for Scientific Research (CNRS), France.

Sir J. Fraser Stoddart, born 1942 in Edinburgh, UK. Ph.D. 1966 from Edinburgh University, UK. Board of Trustees Professor of Chemistry at Northwestern University, Evanston, IL, USA.

Bernard L. Feringa, born 1951 in Barger-Compascuum, the Netherlands. Ph.D.1978 from the University of Groningen, the Netherlands. Professor in Organic Chemistry at the University of Groningen, the Netherlands.

Milk Teeth

                                 Mystery Behind Losing Our Milk Teeth in Childhood

                                                                          By JULIA SAMUEL

Teeth are subject to a lot of wear and tear, so it makes sense to be able to replace them during the lifetime of the animal. Surprisingly, however, the teeth of the earliest jawed vertebrates were fixed to the jaw bones and could not be shed.

Tooth shedding eventually evolved independently on two occasions, using two quite different processes. In sharks and rays, the fibres that anchor the tooth to the skin of the jaw dissolve and the whole tooth simply falls out. 

In bony fish and land vertebrates, the developing tooth becomes attached directly to the jaw bone by a special tissue known as "bone of attachment", and when it is time for the tooth to be shed this attachment must be severed; specialized cells come in and resorb the dentine and bone of attachment until the tooth comes loose. That's why our milk teeth loose their roots before they are shed. But when did this process evolve? 

The authors of the new study decided to investigate a jaw bone of the 424 million year old fossil fish Andreolepis from Gotland in Sweden, close to the common ancestor of all living bony fish and land vertebrates. 

The jaw is a tiny thing, less than a centimetre in length, but it hides a wonderful secret: the internal microstructure of the bone is perfectly preserved and contains a record of its growth history. 

Until recently it has only been possible to see internal structures by physically cutting thin sections from the fossil and viewing them under the microscope, but this destroys the specimen and provides only a two-dimensional image that is hard to interpret. 

However, at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, it is now possible to make tomographic scans that capture the same level of microscopic detail, in three dimensions, without damaging the specimen. Donglei Chen, first author of the study, has spent several years painstakingly 'dissecting' the scan data on the computer screen, building up a three-dimensional map of the entire sequence of tooth addition and loss - the first time an early fossil dentition has been analyzed in such detail. 

"Every time a tooth was shed, the resorption process created a hollow where it had been attached. When the succeeding replacement tooth was cemented in place by bone of attachment, the old resorption surface remained as a faint buried scar within the bone tissue. I found up to four of these buried resorption surfaces under each tooth, stacked on top of each other like plates in a cupboard. This shows that the teeth were replaced again and again during the life of the fish," explains Donglei Chen. 

This is the earliest known example of tooth shedding by basal resorption, and it seems to be most similar to the process of tooth replacement seen today in primitive bony fish such as gar (Lepisosteus) and bichir (Polypterus). Like in these fish, new replacement teeth developed alongside the old ones, rather than underneath them like in us.

"The amount of biological information we get from the scans is simply astonishing. We can follow the process of growth and resorption right down to cellular level, almost like in a living animal. As we apply this technique to more early vertebrates, we will come to understand their life processes much better - and no doubt we will be in for some major surprises," says Per Ahlberg, one of the leaders of the project.

                                     Delay in Patents can Slow Down Development in Medicine

In India, the delay in the patents for various innovations can slow down the improvement in the field of medicine, said health experts.

   Although the government has started indulging in many schemes and provisions, patients are yet to reap benefits from them and hence many physicians themselves have indulged in creating innovative therapies or treatments that can be made available to patients at a very economical cost, experts said. 

      "Patents for innovations by the doctors should be speeded up in India. These out-of-the-box ideas by the physicians will ensure that the expenses of all the treatments do not put a load on the patient's pocket and some innovations help generate a positive relation between the patient and the hospital," said Ram Prabhoo, President of the Indian Orthopaedic Association.

Prashant Jha from the All India Institute of Medical Sciences said that he has created a Feto Maternal device that can assess fetal distress, and can be helpful for patients as well as doctors. 

"We have come up with a app named TNM that helps standardise the diagnosis for different types of cancer and its stages. This app has a 20-second Questionnaire which needs to be filled with just a yes or no and immediate diagnosis of the node of cancer and its stage is revealed," said Palak Popat, associated with city based Tata Memorial Hospital. 

According to Popat, the app will become helpful for junior doctors, radiologists and general practitioners who are not specialists in Oncology. 

"This app will help provide immediate information to the patients and their family," said Popat. 

 

                       SOURCE- medindia.net by Julia Samuel on  October 17, 2016 at 10:26 PM

IIT Bombay researchers a step closer to treating                                         Parkinson’s disease

Researchers from the Indian Institute of Technology, Bombay (IIT B) have taken the first successful step at regenerating neurons in a Parkinson mouse model by using mesenchymal stem cells (MSCs) encapsulated in an amyloid hydrogel. The hydrogels which provide scaffolding for stem cells to develop into neurons when implanted in the brain are developed from a special class of proteins called amyloids. The results were published in the journal NPG Asia Materials.

      The hydrogel enabled the delivery and engraftment of mesenchymal stem cells in two regions of the mice brain - substantia nigra and striatum - where the cells were injected. “We do not have direct proof that mesenchymal stem cells have become neurons. But the stem cells transplanted at the substantia nigra site were differentiating into neuron-like cells,” says Subhadeep Das from IITB-Monash Research Academy, IIT Bombay and the first author of the paper.

“We wanted to first know if the cells were surviving and were contained at the site. So the time point was short, and we sacrificed the animals at the end of the seventh day after transplantation,” he says. “Further studies for prolonged periods will tell if the mesenchymal stem cells become matured neurons.”

In the case of Parkinson’s, neurons based in the substantia nigra region of the brain release dopamine at the striatum. Since the connection between the two regions is lost in the case of Parkinson’s, the researchers implanted the stem cells at both the sites.

But before transplanting the stem cells encapsulated in the hydrogel into the brain of the mice, the researchers tested the hydrogel in the lab for toxicity. Both neural precursor cell lines and mesenchymal stem cells were cultured in the amyloid hydrogel. And 2D and 3D culture tests for toxicity were carried out for both short (24 hours) and long (120 hours) term and the results compared with a collagen hydrogel, which served as control. “The compatibility of amyloid hydrogel was similar to collagen,” says Das.

Besides being a good scaffold that facilitates the differentiation of stem cells into neurons and not being toxic, the hydrogel should also not trigger the immune system from mounting a violent reaction against it when implanted into the brain. So the researchers injected the hydrogel into rat brain to test for any possible inflammatory response or immune rejection of the amyloid hydrogel. While two types of inflammatory cells - microglia and atrocytes - accumulated near the hydrogel, their levels subsided by 21 days.

In a next step, they implanted the hydrogel containing the mesenchymal stem cells in the brain of the Parkinson mouse model. “The hydrogel was able to improve the viability of the transplanted cells and were able to contain them at the site where they were implanted,” says Das. The control cells that were not contained in hydrogel were three times less viable than the cells contained in the hydrogel.

“Amyloids are among the most robust protein/peptide-based materials ever evolved in nature. We just utilised these superior materials property of amyloids for targeting stem cell delivery in the brain and their differentiation to neurons. On the one hand, amyloid-based hydrogels are capable of protecting delicate stem cells within the hydrogels matrix, while on the other hand, they are able to guide the differentiation of stem cells towards neurons,” Samir K. Maji from the Department of Biosciences and Bioengineering, IIT Bombay and the corresponding author of the paper says in a release.

There are three major challenges when stem cells are transplanted or injected into the brain - the cells should survive, should not migrate to different places where they are not required, and should become functional neurons and integrate with the existing neural circuit. “Our material has solved the first two challenges. We are now working on the third one,” says Das confidently.

                                                            SOURCE- THE HINDU October 16, 2016 18:52 IST

Important Synthesis, Mechanism Of action and their uses For 2nd Sessional 2016 (B.pharm 5th Sem)

1.Lignocaine

2.Ephedrine

3.Pilocarpine

4.Neostigmine

5.Physostigmine

6.Methohexital

7.Ketamine

SAR

1.Local anesthetics
2.Cholinergic Drugs
3.Adrenergic Drugs