New Method Turns Tons of Wine Waste into Useful Chemicals

Italian scientists have devised an innovative and economically feasible biorefinery that can squeeze more chemicals out of the mountains of grape waste produced during wine production.

Last year around 28 billion litres of wine were produced globally—enough to fill over eleven thousand Olympic sized swimming pools. But after pressing the last of the juice from the grape, a whole lot of skins and seeds are left—around 5 million tons of the stuff.

Traditionally this waste, known as pomace, is redistilled to produce spirits such as grappa. But changes in EU policy have reduced the subsidies given to distillers in an attempt to get more from this resource. Though useful chemicals such as polyphenols (natural antioxidants used in cosmetics and preservatives) or methane-rich biogas can be extracted from red grape pomace, you’d be hard pressed to turn a profit from existing single-product valorisation processes.

Raise a glass then to Lorenzo Bertin and colleagues at the University of Bologna, who have developed a multi-purpose biorefinery which not only produces polyphenols, but fatty acids, biopolymers, and biomethane too. Using supercritical carbon dioxide, the team extracted the useful polyphenols and sugars, before using anaerobic digestion to produce other useful compounds such as fatty acids. The leftover solid waste underwent further microbial treatment to produce methane, whilst any remaining liquid waste was aerobically fermented to produce environmentally friendly polymeric materials. Bertin’s biorefinery is striking for the sheer range of products it is able to extract from a single integrated process—making this green approach much more industrially viable

REF: scientificamerican.com

Bacteriophages generate electricity under pressure

Piezoelectric(the electric charge that accumulates in certain solid materials (such as crystals, certain ceramics, and biological matter such as bone, DNA and various proteins) in response to applied mechanical stress.) generators convert mechanical energy into electrical energy. For applications in human implants, these generators must be made from non-toxic, biocompatible materials. To this end, Yoon-Hwae Hwang from the Pusan National University and co-workers successfully employed M13 bacteriophage nanopillars – formed by ejecting phages into a template – as building blocks to make nanogenerators. Similar to squashing a spring, applying a perpendicular load to the nanogenerators produced electricity. The vertical phage pillars in the device improved output voltage compared to a lateral alignment because of higher elasticity along the axial direction of the bacteriophage DNA.

The performance was improved by bioengineering. Substituting four negatively-charged glutamates for alanine on the phage genome increased the dipole moment of the protein, almost doubling the electrical output of the generator compared to the unaltered DNA. Tuning the generator further tripled the output and meant the bacterial nanogenerator could light up an LCD display with only pressure.

REF: rsc.org, wikipedia

Colour's Of Flame Test

REF: compoundinterest.com

The Nobel Prize Laureate Richard Heck Dies At 84

American scientist Dr. Richard F. Heck, a 2005 Wallace Carothers awardee and 2010 Nobel Prize laureate in Chemistry, died on Oct. 10, Saturday in Manila, Philippines.

Heck, along with Japanese scientists Ei-ichi Negishi of Purdue University in Indiana and Akira Suzuki of Hokkaido University in Japan, won the Nobel for successfully cross coupling carbon molecules using palladium as a catalyst.

Dubbed the Heck Reaction, this groundbreaking discovery led to breakthroughs in drug development. It played a vital role in creating new types of drugs for cancer, asthma, HIV, migraine headaches and other diseases.

The Heck Reaction also helped improve the method of DNA sequencing by allowing organic dyes to bind with DNA bases. The process he discovered is also currently used to produce various consumer, electronic and industrial products, ranging from sunscreens to computer monitors.

Thomas Colacot, a specialist in the field of chemistry describes this process as "the reaction of the 21st century."

Nancy M. Targett, acting president of the University of Delaware, where Heck worked for 18 years and later became professor emeritus, recognized his contribution.

"His groundbreaking work that was saluted by the Nobel Prize Committee demonstrates how scientific inquiry can have a profound effect on everyday lives of us all," Targett said.

Heck, however, suffered for years from diabetes, chronic obstructive pulmonary disease (COPD) and slight dementia. Two private nurses took turns in caring for him in his home in Quezon City.

REF: techtimes.com

Chemical Compounds Name Based On Their Shape

Barrelene	Barrel
Basketane	Basket
Churchane	Church
Cubane	Cube.
Dodecahedrane	Dodecahedron
Fenestrane	Window pane motif
Housane	House
Ladderane	Ladder
Olympiadane	Olympic rings
Olympicene	Olympic Flag(Ring)
Penguinone	Penguin
Prismane	Prism
Quadratic acid	Square
Tetrahedrane	Tetrahedron.

REF : wikipedia.com

Transforming all donated blood into a universal type

Every day, thousands of people need donated blood. But only blood without A- or B-type antigens, such as type O, can be given to all of those in need, and it’s usually in short supply. Now researchers are making strides toward fixing the situation. In the Journal of the American Chemical Society, they report an efficient way to transform blood types A and B into a neutral type that can be given to any patient.
Stephen G. Withers and colleagues note that currently, blood transfusions require that the blood type of the donor match that of the recipient.side effects, and could even die. Since blood type O can be
given to anyone because it doesn’t provoke an immune reaction, researchers have spent years searching for a way to convert types A and B into and unreactive type. Current methods of enzymatic removal of the terminal N-acetylgalactosamine or galactose, the sugars that distinguish blood type, are inefficient. Withers’s team investigated ways to boost the enzymes’ activity.
The researchers altered one of those enzymes and improved its ability to remove type-determining sugars by 170- fold, rendering it antigen-neutral and more likely to be accepted by patients, regardless of their blood type. In addition to making it easier to provide blood transfusions, the researchers say their advance could potentially allow organ and tissue transplants from donors who would otherwise be mismatched. Read more about the research: “Toward Efficient Enzymes for the Generation of Universal Blood through Structure-Guided Directed Evolution,” Journal of the American Chemical Society, 2015, 137 (17), pp 5695–5705.

REF: InChemistry Journal (ACS Publications)

Drug Delivery Technique To By Pass Blood- Brain Barrier

Researchers at Massachusetts Eye and Ear/Harvard Medical School and Boston University have successfully shown neuroprotection in a Parkinson's mouse model using new techniques to deliver drugs across the naturally impenetrable blood-brain barrier. Their findings, published inNeurosurgery, lend hope to patients around the world with neurological conditions that are difficult to treat due to a barrier mechanism that prevents approximately 98 percent of drugs from reaching the brain and central nervous system.

"We are developing a platform that may eventually be used to deliver a variety of drugs to the brain," said senior author Benjamin S. Bleier, M.D., of the department of otolaryngology at Mass. Eye and Ear/Harvard Medical School. "Although we are currently looking at neurodegenerative disease, there is potential for the technology to be expanded to psychiatric diseases, chronic pain, seizure disorders and many other conditions affecting the brain and nervous system down the road."

Using nasal mucosal grafting, researchers delivered glial derived neurotrophic factor (GDNF), a therapeutic protein in testing for treating Parkinson's disease, to the brains of mice. They showed through behavioral and histological data capture that their delivery method was equivalent to direct injection of GDNF -- the current gold standard for delivering this drug in Parkinson's disease despite its traumatic nature and high complication rates -- in diffusing drugs to the brain.

The researchers chose to test their delivery method with GDNF because the therapy has been shown to delay and even reverse disease progression of Parkinson's disease in pre-clinical models. The study was funded by The Michael J. Fox Foundation for Parkinson's Research (MJFF).

"Brain diseases are notoriously difficult to treat due to the natural protections the body builds against intrusion," said Jamie Eberling, PhD, senior associate director of MJFF research programs. "Dr. Bleier's group has identified a potential avenue to pass that barrier, and we look forward to the next stage of research to further test its utility in people with Parkinson's disease ."

Nasal mucosal grafting is a technique regularly used in the ENT field to reconstruct the barrier around the brain after surgery to the skull base. ENT surgeons commonly use endoscopic approaches to remove brain tumors through the nose by making a window through the blood-brain barrier to access the brain. Once they have finished the treatment, they use adjacent nasal lining to rebuild the hole in a permanent and safe way. The safety and efficacy of these methods have been well established through long-term clinical outcomes studies in the field, with the nasal lining protecting the brain from infection just as the blood brain barrier has done.

Dr. Bleier saw an opportunity to apply these techniques to the widespread clinical dilemma of delivering drugs across the barrier to the brain and central nervous system. By functionally replacing a section of the blood-brain barrier with nasal mucosa, which is more than 1,000 times more permeable than the native barrier, surgeons may create a "screen door" to allow for drug delivery to the brain and central nervous system.

The technique has the potential to benefit a large population of patients with neurodegenerative disorders, where there remains a specific unmet need for blood-brain penetrating therapeutic delivery strategies.

"We see this expanding beyond Parkinson's disease, as there are multiple diseases of the brain that do not have good therapeutic options," Dr. Bleier said. "It is a platform that opens doors for new discovery and could enable drug development for an underserved population."

REF: sciencedaily.com

Artificial Skin That can sense

  

Zhenan Bao, a professor of chemical engineering at Stanford, has spent a decade trying to develop a material that mimics skin's ability to flex and heal, while also serving as the sensor net that sends touch, temperature and pain signals to the brain. Ultimately she wants to create a flexible electronic fabric embedded with sensors that could cover a prosthetic limb and replicate some of skin's sensory functions.

Bao's work, reported today in Science, takes another step toward her goal by replicating one aspect of touch, the sensory mechanism that enables us to distinguish the pressure difference between a limp handshake and a firm grip.

"This is the first time a flexible, skin-like material has been able to detect pressure and also transmit a signal to a component of the nervous system," said Bao, who led the 17-person research team responsible for the achievement.

Benjamin Tee, a recent doctoral graduate in electrical engineering; Alex Chortos, a doctoral candidate in materials science and engineering; and Andre Berndt, a postdoctoral scholar in bioengineering, were the lead authors on the Science paper.

Digitizing touch

The heart of the technique is a two-ply plastic construct: the top layer creates a sensing mechanism and the bottom layer acts as the circuit to transport electrical signals and translate them into biochemical stimuli compatible with nerve cells. The top layer in the new work featured a sensor that can detect pressure over the same range as human skin, from a light finger tap to a firm handshake.

Five years ago, Bao's team members first described how to use plastics and rubbers as pressure sensors by measuring the natural springiness of their molecular structures. They then increased this natural pressure sensitivity by indenting a waffle pattern into the thin plastic, which further compresses the plastic's molecular springs.

To exploit this pressure-sensing capability electronically, the team scattered billions of carbon nanotubes through the waffled plastic. Putting pressure on the plastic squeezes the nanotubes closer together and enables them to conduct electricity.

This allowed the plastic sensor to mimic human skin, which transmits pressure information as short pulses of electricity, similar to Morse code, to the brain. Increasing pressure on the waffled nanotubes squeezes them even closer together, allowing more electricity to flow through the sensor, and those varied impulses are sent as short pulses to the sensing mechanism. Remove pressure, and the flow of pulses relaxes, indicating light touch. Remove all pressure and the pulses cease entirely.

The team then hooked this pressure-sensing mechanism to the second ply of their artificial skin, a flexible electronic circuit that could carry pulses of electricity to nerve cells.

Importing the signal

Bao's team has been developing flexible electronics that can bend without breaking. For this project, team members worked with researchers from PARC, a Xerox company, which has a technology that uses an inkjet printer to deposit flexible circuits onto plastic. Covering a large surface is important to making artificial skin practical, and the PARC collaboration offered that prospect.

Finally the team had to prove that the electronic signal could be recognized by a biological neuron. It did this by adapting a technique developed by Karl Deisseroth, a fellow professor of bioengineering at Stanford who pioneered a field that combines genetics and optics, called optogenetics. Researchers bioengineer cells to make them sensitive to specific frequencies of light, then use light pulses to switch cells, or the processes being carried on inside them, on and off.

For this experiment the team members engineered a line of neurons to simulate a portion of the human nervous system. They translated the electronic pressure signals from the artificial skin into light pulses, which activated the neurons, proving that the artificial skin could generate a sensory output compatible with nerve cells.

Optogenetics was only used as an experimental proof of concept, Bao said, and other methods of stimulating nerves are likely to be used in real prosthetic devices. Bao's team has already worked with Bianxiao Cui, an associate professor of chemistry at Stanford, to show that direct stimulation of neurons with electrical pulses is possible.

Bao's team envisions developing different sensors to replicate, for instance, the ability to distinguish corduroy versus silk, or a cold glass of water from a hot cup of coffee. This will take time. There are six types of biological sensing mechanisms in the human hand, and the experiment described in Science reports success in just one of them.

But the current two-ply approach means the team can add sensations as it develops new mechanisms. And the inkjet printing fabrication process suggests how a network of sensors could be deposited over a flexible layer and folded over a prosthetic hand.

"We have a lot of work to take this from experimental to practical applications," Bao said. "But after spending many years in this work, I now see a clear path where we can take our artificial skin."

REF: sciencedaily.com

Noble Prize Winners In Chemistry 2015

MECHANISTIC STUDIES IN DNA REPAIR

Every day the DNA held within our cells is constantly subjected to assaults from the environment, such as UV radiation from the Sun. But it’s not just external factors that we need to worry about. Despite scientists originally thinking that DNA is an extremely stable molecule, it actually turns out to be inherently unstable, constantly undergoing spontaneous changes and mutations. So how come it doesn’t simply disintegrate into chemical chaos?

The study was done by three people named Tomas Lindahl, Paul Modrich and Aziz Sancar.The answer lies in DNA repair mechanisms. Tomas Lindahl first demonstrated that DNA decays at such a rapid rate that development of life on Earth should have been impossible. This led him to look into how this collapse of DNA is prevented, and he discovered one such mechanism: base excision repair. When part of the DNA strand mutates, or spontaneously changes, a specific enzyme discovers this defect and “cuts” the damage out of the strand. Further enzymes then join in the action, filling in the gap with the original, correct sequence.

Mutations can also occur as cells are dividing, a process that requires copying the DNA for each new cell. This process is not error-proof, and mistakes can be made along the way, like adding in an incorrect building block, or base, that doesn't match up with the one on its partner strand (remember DNA is a double helix). Paul Modrich looked into how such mistakes are prevented during cell division, and described a mechanism called mismatch repair. This process, which also involves snipping out part of the DNA and replacing it, reduces the error frequency during DNA replication 1000-fold.

        The nucleotide excision repair, the mechanism that cells use to repair UV damage to DNA. People born with defects in this repair sstem will develop skin cancer if they are exposed to sunlight. The cell also utilises nucleotide excision repair to correct defects caused by mutagenic substances, among other things.
Another source of DNA damage is from external factors. One example is the damage that UV radiation does to our DNA, and Aziz Sancar mapped the mechanism that exists to repair this damage, called nucleotide excision repair. When a stretch, rather than a single site, of DNA has been corrupted by UV radiation, the enzymes involved in this mechanism come along and remove a large piece of the DNA containing the fault. The resulting gap then gets filled back in. People who are born with defects in this particular mechanism develop skin cancer if exposed to sunlight.

The mechanisms described by these Nobel Laureates have given us a fundamental insight into how cells function and repair themselves, as well as giving new targets for the development of new cancer treatments.   

REF: iflscience.com, thehindu.com