Winemaking Waste Could Become Biofuel Starter

Grape pomace, the mashed up skins and stems left over from making wine and grape juice, could serve as a good starting point for ethanol production, according to a new study.

Due to growing interest in biofuels, researchers have started looking for cheap and environmentally sustainable ways to produce such fuels, especially ethanol. Biological engineer Jean VanderGheynst at the University of California, Davis, turned to grape pomace, because winemakers in California alone produce over 100,000 tons of the fruit scraps each year, with much of it going to waste.

To determine how much ethanol they could produce from pomace, VanderGheynst and her team processed pomace from the Sutter Home Winery in St. Helena, Calif., under various fermentation conditions. The researchers found that pomace from white grapes yielded the most ethanol. Winemakers only squeeze the juice out of these grapes and don’t ferment the pomace, so much of the fruits’ sugar remains. Meanwhile, red grape pomace has been fermented over long periods, so less sugar remains for ethanol production. But the scientists found that adding dilute acid to the red grape pomace boosted ethanol yields.

On average, the researchers found, grape pomace produces less than half as much ethanol as corn does by dry weight. To squeeze the maximum ethanol out of the grape waste, researchers would need to develop techniques to convert the grape’s cellulose into ethanol, says lead author Yi Zheng, a chemist at the biotechnology company Novozymes, in Denmark. But, he thinks pomace could still be a feasible feedstock because the material is readily available. Ethanol producers could make grape pomace more economically viable if they combined ethanol production with manufacture of other pomace-based products, such as fertilizers or animal feed, he says.

New Research Of Self-assembling Polymeric Copper Catalyst

Few recently discovered chemical reactions have proven as powerful as the copper-catalysed Huisgen 1,3-dipolar cycloaddition between azides and alkynes—a transformation better known as a ‘click reaction’. The process gets its nickname from the robust, reliable way that the azide and the alkyne organic functional groups ‘click’ together.

From materials science to biochemical applications, this dependable method for joining molecules together has been exploited widely in the decade since its discovery. Now, Yoichi Yamada, Shaheen Sarkar and Yasuhiro Uozumi at the RIKEN Advanced Science Institute in Wako have developed a new form of heterogeneous copper catalyst that promises to make the click reaction more efficient than ever.

Heterogeneous catalysts do not dissolve into the reaction mixture; they remain as a solid inside the reaction flask, offering a catalytic surface on which the reaction can take place. The key advantage of these catalysts is that they can easily be recaptured for re-use at the end of a reaction, often by simple filtration. Their disadvantage is that they are less intimately dispersed with the reactants than catalysts that dissolve, slowing the reaction.

The researchers overcame this disadvantage by embedding their copper within a self-assembled two-component polymer. The polymer backbone is made of a material called isopropylacrylamide, which has a hydrophobic sub-section and a hydrophilic sub-section. Overall, the material acts as an ‘amphiphilic sponge’: it readily draws in reactants and substrates regardless of their hydrophobicity, Yamada says.

The re-usable catalyst should find a host of applications, Yamada says. “The catalyst will be applied to the synthesis of pharmaceutical compounds and functional organic materials.” The next step for the researchers is to incorporate the catalyst into a ‘flow system’, in which the catalyst is immobilized within a cartridge through which substrates and reagents are continually pumped, generating a continuous steady stream of product.

The second polymer component is an imidazole, an electron-donating material that stabilizes and activates the copper to accelerate the click reaction. “The catalytic copper species within the sponge instantaneously react with substrates and reactant to give the products and to regenerate the catalyst,” Yamada explains.

The material’s performance is the best yet reported for a heterogeneous click catalyst, he adds. The best previous materials had turnover numbers below 1,000 before the catalyst would become deactivated, whereas the team’s catalyst had a turnover number of 209,000. The catalyst’s turnover frequency was also fast, turning reactants into product at a rate of 6,740 conversions per hour.

The Analysis Of Cable Industry

The cable industry is trying to exclude station promos from a new law that says TV commercials can be no louder than the programs they accompany.

The Commercial Advertisement Loudness Mitigation Act, or CALM Act, requires that TV commercials be no louder than the programs they accompany. It’s up to the Federal Communications Commission to set and enforce the new rules.

The wire and cable industry comprises 40% of the entire electrical industry, which is expected to double in size over the next five years. The industry is growing at a CAGR of 15% as a result of growth in the power and infrastructure segments. It is expected to grow at similar rate for the next five years. The government’s emphasis on the power sector reforms and infrastructure will further drive growth. Nevertheless, the cable industry still can’t get its head around the idea that TV viewers should be able to watch the tube at the volume of their own choosing.

The wire and cable industry will eventually focus on supplying cables for specific applications pertaining to the industry needs. India has a lot of potential in the mining, power, oil and gas, metro railways, cement industry , steel industry and other sectors. Different kinds of cables like extra high voltage cables, elastomer cables, etc, are now being used for special applications such as mining/oil sector, shipbuilding /crane cables/elevator cables, cables for solar power plants, to harness power for new generation motor vehicles, windmill solutions, security systems and other types of data cables (antimony ingots are used in alloy,ternealloy,cable and printing industry).

This field requires and teaches freshers and professionals to be techno-commercially inclined. Ideally, electrical/mechanical engineers for manufacturing, electrical engineers for EPC related sales for special applications, managers with operations knowledge for implementation of world class manufacturing techniques, managers with knowledge of creative/application based marketing, MBAs who can use various strengths of companies and make use of adjacent opportunities, as well as fresh graduates who have the zeal to outperform and change customer outlook. The sector also provides tremendous entrepreneurial opportunities in trading, contracting and manufacturing.

Remuneration depends on the particular company, based on its own outlook. It also depends on the institute from where the candidates are sourced. Pay packets offered are on a par with market standards and is not a limiting factor for the right candidates. The remuneration for a fresher may range between rupees two lakh and five lakh per annum.

Omkar Expands Its India API Production

India’s Omkar Speciality Chemicals forays into API business and has acquired LASA Laboratory on Oct 18,2012. Recently, the company is again expanding its API and intermediate manufacturing in Badlapur, Maharashtra, this time with an investment of nearly $5 million in an API plant.

API is the largest segment of the specialty chemicals industry.  The growth of API market in India is likely to add pressure on the production capacities. This will result in an increased scope and revenue for OSCL. Increased restrictions on the production cost have forced the API manufacturers from developed countries to shift their manufacturing base to the emerging economies like India, China and Eastern European countries like Hungary and Poland. This has helped emerging countries to make their global presence felt in the API market.

The acquisition of Lasa Labs in April 2012 has enabled OSCL to gain a portfolio of 10 APIs like Albendazole, Closental and Flucanazole. Though most of the APIs are generic, they still offer incremental market opportunity for OSCL. For instance, Albendazole is estimated to have a global annual demand of about Rs 1.7 billion.

The company will invest 25 crore ($4.67 million) to expand the production capacity to 1,950 metric tons from 1,700 metric tons now at one facility, an expansion it says will be online in 8 or 9 months, the Business Standard reports. “There is tremendous pressure from customers as well, both domestic and global, for supply of products,” Chairman Pravin Herlekar tells the newspaper.

Herlekar said the company also is looking at building capacity with some acquisitions. “Having a stronghold in Hyderabad, a hub of pharmaceutical and biotech industry, we are considering having a manufacturing base here via the inorganic growth route,” he said.

The company next month will bring online additional capacity at another plant in that area. It now will be able to produce up to 2,800 metric tons of intermediates (such as 3-Fluoro-5-(trifluoromethyl)benzonitrile, the CAS number is 149793-69-1) for anti-cholesterol, anti-depression and cardiovascular drugs. The company in April acquired Lasa Labs, which has a plant that makes APIs for the veterinary drug industry.

Pharma industry in India is growing at a reasonable pace. This is on account of population growth and the changing life styles of people. The drug for applications on anti-diabetic, anti-cholestrol, anti-hypertension, anti-asthematic, etc., has been constantly in demand. Interestingly, the Indian pharma industry is expected to do well on the back of growing global demand for generics drugs.

Why Is Sulfuric Acid So Functional?

Sulfuric acid is involved, in some way or the other, in the manufacture of practically everything, such as petrol, fertilizers, cars and soaps. They, like a lot of other things, require sulfuric acid to be made. That’s why sulfuric acid is called the king of chemicals.

On earth, sulfuric acid does not exist in a natural form. But on the planet Venus, there’s plenty of it. There are lakes of the acid, which evaporate to form clouds, which then rain sulfuric acid upon the Venerean surface. Indeed, the production of sulfuric acid is sometimes used as a measure of how industrially advanced a country is. India produces about 48 lakh tonnes of this acid a year.

Sulfuric acid is often stored in concentrated form. When diluting it, never pour water into the acid. That will make the whole thing explode. Instead keep crushed ice (made from pure water) in a large beaker, and pour the acid onto it, drop by drop. The ice absorbs the heat of the reaction, so it won’t explode. When the ice melts, you get dilute sulfuric acid.

Large amounts of sulfuric acid is used to clean up rust from steel rolls. These cleaned up rolls are used to make cars, trucks, as well as household appliances. It is used to make aluminium sulfate, which is needed for making paper. It is used to make ammonium sulfate, a common fertilizer. Sulfuric acid is used in petroleum refining to make high-octane petrol, which burns efficiently. It is put in the lead-acid batteries of your car battery … well, it is used to make practically everything!

60% of all sulfuric acid produced is mixed with crushed phosphate rock to make phosphoric acid. Phosphoric acid has two uses – to make phosphate fertilizers, and to make sodium triphosphate, which is a detergent.

Never handle sulfuric acid yourself. If you spill a drop on your hand, it will react with the tissue, burning it instantly. It also causes dehydration. Fumes of sulfuric acid can cause blindness, and damage the lungs if inhaled. In case you accidentally spill acid on yourself, wash it under a tap for fifteen minutes at least, so that even the tiniest drop is washed away.

Never pour it from the bottle, but always use a thick glass pipette with a rubber bulb. The best is to let your teacher handle it, while you stand aside and watch. Even dilute sulfuric acid is dangerous. When handling sulfuric acid, always wear thick gloves and a lab coat or apron. Never handle it on an open bench, but use it in a fume hood. 

Researchers Use Voltammetry to Probe the Brain’s Chemistry

Our brains are constantly awash in chemicals that serve as messengers, transporting signals from one neuron to another.  It’s a really nifty system, although scientists still aren’t clear on how, exactly, those chemical messages end up being converted into behaviors like kicking a ball or doing really complicated mathematical computations.

If scientists could get a clear picture of how that conversion works, it would further our understanding of brain function, and open up a host of new treatments for diseases like Parkinson’s or diabetes. So how do we figure out which chemicals are in the brain and what they’re doing in real time?

Chemist Leslie Sombers and her graduate student Leyda Lugo-Morales use an elegant approach that allows for real-time measurement of chemical fluctuations in the brain.  They use voltammetry, which sounds really cool and Frankenstein-y, but is basically a method of electrochemical scanning where voltage is applied to, and current is collected from, a carbon fiber microelectrode that is about 10 times smaller than a human hair.  The resulting data is in the shape of a graph called a voltammogram.  The size of the graph indicates how much of a particular chemical is present and the shape tells the researchers which chemical it is.

Some of the chemicals Sombers is interested in measuring – like glucose, for instance –are normally invisible to electrochemical measuring techniques like voltammetry.  So to make it work, Sombers attaches an enzyme to the electrode that reacts with glucose. The glucose molecule reacts with the enzyme and produces hydrogen peroxide, which oxidizes as an electrical potential is applied to the electrode. The resulting current gets measured, and that data is captured in the voltammogram. When the scientists see the hydrogen peroxide in their voltammogram, they know they’ve found glucose.

Lugo-Morales has already used the probe to make real-time measurements of glucose fluctuations at different locations in a rodent brain. She found that the amounts differed depending upon where the probe was located and that they fluctuated quite a bit over very short times –subseconds – which is how quickly our neurons work.

“A lot of people want to understand glucose dynamics in the brain,” Sombers says. “Sixty  to 70 percent of diabetics show neuronal dysfunction, plus glucose has been linked to diseases like schizophrenia and Alzheimer’s.  If we can understand how glucose is used by the brain we can create better treatments for these diseases.”

First Successful Total Synthesis of Erythropoietin

“Blood is quite a peculiar kind of juice”—that is what Mephisto knew, according to Goethe’s “Faust”. But if blood really is very special, then erythropoietin (EPO) must be a very special molecule, as it triggers the production of our red blood cells. After ten years of intense research, American scientists have now succeeded in making a fully synthetic version of this special molecule. This achievement represents a landmark advance in the chemical synthesis of complex biological molecules from basic building blocks.

EPO is a hormone produced in the kidneys that induces the differentiation of bone marrow stem cells to erythrocytes (red blood cells). Upon sensing decreased oxygen in circulation, EPO is secreted to boost the production of red blood cells. EPO has found many therapeutic applications. Dialysis patients, whose haematosis is affected by renal failure, are treated with EPO and the drug is also given to cancer patients who have undergone chemotherapy or radiation therapy. Black sheep among racing cyclists, and other athletes, have abused EPO in an effort to improve their athletic performance.

Until now, only nature itself was able to synthesize EPO. For therapeutic use, the drug has to be produced biotechnologically in cell cultures. Iy is not actually one compound but a large family of molecules. Known as glycoproteins, the structures are composed of a protein decorated with four carbohydrate sectors. The protein portion is always the same, as are the locations at which the carbohydrate domains are attached. Yet, in endogenous EPO protein, there are a wide variety of different carbohydrate sectors that may be appended to the protein. It has not been possible to access naturally occurring EPO as a homogeneous, pure molecule.

By adopting the tools of chemical synthesis, the investigators were able to make, for the first time, pure “wild type” EPO glycoprotein incorporating the natural amino acid sequence and four carbohydrate sectors of strictly defined structure. Extension of this strategy will enable scientists to make numerous versions of the molecule and to study how differences in the chemical structure of the carbohydrate domains may affect how the glycoprotein induces the production of red blood cells.

The structure of the synthetic EPO was verified by mass spectrometry. Tests using stem cells proved the effectiveness of the synthesized EPO: like its natural counterpart, the synthetic EPO triggered the formation of red blood cells from stem cells.

The Hope Of New Drugs — Sea Sponges

Flinders University researcher Dr Jan Bekker is on a mission to chemically fingerprint South Australia’s marine sponges, with the wider aim of identifying new compounds that could ultimately play an important role in the fight against cancer and infectious diseases.

The Research Associate at Flinders Centre for Marine Bioproducts Development has discovered a large number of new chemicals from about 70 sea sponges, using a computer platform which distinguishes known compounds, which are common to all sponges, from those which have not yet been identified.

Marine sponges, which live in abundance in SA waters, constantly produce an array of different molecules as a natural defence mechanism against microorganisms and predators. Dr Bekker said, “sea sponges are sedentary, they don’t move around, so over millennia they have evolved a unique ability to produce chemicals to defend themselves from certain dangers in their environment including other dangerous animals and diseases.”

“Many of these chemicals have possible medical applications and diverse human health benefits,” he said.

Using mass spectrometry, an analytical technique for determining the chemical structures of molecules, Dr Bekker is metabolically “fingerprinting” the chemicals before using computational methods to identify new compounds. He said computational methods were also being used in combination with laboratory tests to predict anti-cancer and antibiotic properties in new sponges, with the ultimate aim to grow sponge cells in bioreactors to produce large amounts of the precious compounds.

“With thousands of different marine species in our waters containing many thousands of different compounds, the idea is to reduce the clutter of information and quickly zoom in on the unique chemicals that are functional and valuable, such as anti-cancer compounds,” he said.

“This will reduce the cost and time needed for bioproduct discovery, enabling more discoveries to become commercially available products for human health, in a shorter amount of time.”

Kenaf Powder Used to Create New WPC Material

Wood-plastic composites (WPCs) are one of the fastest growing construction components in the wood composites industry. Their popularity is due to low maintenance, high durability, and resistance to termites and other insect attacks. However their widespread usage has been limited due to their high cost in production and in some instances low strength.

The present study focused on assessing the suitability of kenaf core fraction (about 65%of the whole stem of the plant) in powder form as filler material. Kenaf powder, processed from its core fibre, has been shown to offer one potential solution to the increasing scarcity of traditional filler materials. Kenaf stems contain two distinct fibre types, bast and core. Dosing with maleic-anhydride-modified polypropylene (MAPP) in the right amount displayed not only to bridge the interface between the ground kenaf core (GKC) and plastic in the present WPCs, improving stress transfer and increasing their strength and stiffness, but also allow a higher filler loading. Reducing the amount of plastic and increasing the amount of GKC, without sacrificing strength, stiffness or durability, would result in greener WPC products.

Researchers examined the possibility of replacing sawdust with GKC and measured the mechanical properties of the resulting composites. They also looked at the effect of increasing maleic anhydride modified polypropylene (MAPP) dosage. Material preparation included GKC drying followed by high intensity blending with polypropylene (PP), coupling agents (MAPP) pellets, and feeding this into a counter-rotating twin-screw extruder for compounding. Compounded blends were then fed to an injection-moulding machine to produce boards of dimensions 153mm x 153mm x 3mm. Specimens were cut from the boards for tensile and bending tests in five replicates. GKC formulation gave the highest average tensile strength, modulus of rupture and modulus of elasticity.

Reducing the amount of plastic and increasing the amount of GKC, without sacrificing strength, stiffness or durability, would result in greener WPC products. The researchers recommend that additional testing and extended research is necessary to investigate the strength of WPC on mechanical properties of modulus of elasticity (MOE) and modulus of rupture (MOR) by carrying out impact test and compressive test which could reveal new discoveries about high filler loading WPCs.

Lab-Evolved Enzyme Starves Tumors

Tumors can grow quickly only when they’re well fed, so doctors seek ways to starve the malignancies. Realizing that cancer cells consume more methionine than healthy cells do, researchers engineered a novel human enzyme that degrades the amino acid. In experiments using mice, the protein stopped tumor growth.

However, the bacterial enzyme causes a strong immune reaction in primates, making it a poor drug candidate, says George Georgiou of the University of Texas, Austin. Also, the enzyme’s half-life in human serum is only two hours, he says. Such a short lifetime would mean patients would have to take larger doses of the enzyme to see any benefit, adds Georgiou.

A human MGL would be a better cancer drug than the bacterial enzyme, Georgiou hypothesized. Unfortunately, no such enzyme exists. He and his team set out to make one.

They selected cystathionine gama-lyase (CGL) as a starting point because it is a human enzyme that closely matches MGL in sequence and catalyzes a similar chemical reaction. Plus, CGL has a longer half-life in serum than MGL does. After comparing the sequences of the two enzymes, the researchers realized that they had to make CGL’s active site more hydrophobic to make it interact with methionine. Compared to cystathionine, which is the molecule CGL binds and reacts with, methionine is greasier.

To modify the enzyme’s active site, the researchers created over 2,000 mutated versions of CGL. They then screened the mutants to determine how fast each chewed up methionine and produced methanethiol (also known as Methyl mercaptan) and alpha-ketobutyrate. The team monitored the reaction by adding the compound 3-methylbenzothiazolin-2-one hydrazone, which reacts with alpha-ketobutyrate to produce an ultraviolet-absorbing molecule. The enzyme that was most efficient at catalyzing the reaction differed from CGL by just three amino acids and had a half-life of 78 hours in human serum.

“It’s very impressive,” says Eugene Frenkel of the University of Texas Southwestern Medical Center. They are “well on their way” to developing a medicine, he says. He thinks the enzyme’s current rate of methionine chewing would work against a wide range of fast-growing tumors. Still, Georgiou wants to increase the enzyme’s speed, which would make a lower dose of the protein able to slow tumor growth.

Chemists Find New Way to Create ‘Building Blocks’ for Drugs

A new way to prepare biaryls – compounds that are essential building blocks in the creation of drugs and many modern materials such as LEDs – using gold as a catalyst is described by researchers from the University of Bristol in this week’s edition of Science. Gold catalysis is easier, cheaper and more environmentally friendly than current methods which use palladium as a catalyst.

Over the last two decades, methods for preparing biaryls have relied predominantly on cross-coupling – a method in which two differentially pre-functionalised benzene rings are connected together in the presence of a catalyst, most often based on the precious metal palladium. However, concerns regarding the environmental impact of such processes, arising from use of toxic metals and the requirement for pre-functionalisation of the coupling partners, have led to a search for more benign alternatives.

As a consequence, much recent interest has focussed on replacing one of the pre-functionalised benzene rings with the desired benzene ring itself, a process known as direct coupling.  Despite major advances in this area, most direct couplings still only operate under undesirable conditions, for example strongly acidic solvents, high temperatures, high concentrations of toxic metal catalysts, large excess of one reactant, and so on.

A new reaction employs a low concentration of a gold catalyst to couple a simple aromatic ring with a non-toxic silicon-based partner, to generate biaryls at room temperature and under exceptionally mild conditions.

These conditions then allow many of the structural features required in drug-like molecules to be tolerated; indeed, the group illustrated the applicability of their chemistry through the concise synthesis of diflunisal (Merck & Co.), a non-opiod, non-steroidal anti-inflammatory drug used for the treatment of chronic arthritis, and for the relief of acute pain following oral surgery.

The appeal of the new direct coupling process is increased still further by the ease with which it can be performed: unlike more traditional procedures, the chemistry is insensitive to the presence of air or moisture, allowing reactions to be assembled on the bench-top without prior purification of reactants and solvents.  The gold catalyst is also cheaper than palladium catalysts, and any gold-residues in the product are considered relatively benign.

How Do Anesthetics Work?

Spanish scientists at the University of the Basque Region and the University of La Rioja have combined mass-resolved electronic spectroscopy and ab initio calculations to model the interactions of anesthetics with proteins. Anesthetics are designed to work as pain relievers by affecting a specific protein in the brain, thereby suppressing pain signal transmittance. “

However, very often there are also undesired interactions with other proteins, which result in secondary effects that sometimes may even lead to the death of the patient”, says Jose A. Fernandez, lead author of a study published recently in ChemPhysChem. “To design new, more specific anesthetics, with reduced secondary effects, it is necessary to have a deep knowledge of how anesthetics interact with proteins.”

The computer modeling needed to gain insights into the working mechanism of these systems is rather difficult. Owing to their non-covalent nature, the interactions that contribute to the final shape of the anesthetic are very small compared to the total energy of the molecule. The methods applied by Fernandez and co-workers on small- or medium-sized systems have allowed them to evaluate the magnitude and quality of different possible non-covalent interactions among a set of selected molecules.

Their approach can even be used to describe very large systems with reasonable accuracy. The mass-resolved detection has yet another advantage: it discriminates between the numerous aggregates formed in the beam, isolating them in different mass channels. Fernández explains: “Several lasers are used to collect data on the structures of the aggregates. These results are then compared with the calculations performed on the system, allowing for the precise determination of the structure of the aggregates.”

In this study, Fernandez and co-workers have focused on the homodimer of the widely used general anesthetic propofol (also known as dispropofol) and its complex with one water molecule. “The calculations predict hundreds of possible conformations for the aggregates—each conformation indicates a different way in which the molecules can interact”, Fernandez says. “

However, the experiments demonstrate that only two [conformations] are stable for the dimer and three for the complex containing water.” Despite the small size and simplified nature of the system studied, the results obtained by this approach provide an accurate simulation of experimental observations, and are an important step towards understanding the many interactions that propofol experiences when injected into a living being.

An Amazing Function Of Date Palm Juice

 

The search for a “greener” way to prevent corrosion on the kind of aluminum used in jetliners, cars and other products has led scientists to an unlikely source, according to a report in ACS’ journal Industrial & Engineering Chemistry Research. It’s the juice of the date palm—those tall, majestic trees that, until now, were noted mainly as sources of food and traditional medicines.

 

He found that date palm juice inhibited corrosion of an aluminum alloy called AA7075, used in aerospace and other applications, in a salt solution. Gerengi noted that while an extract from date palm leaves is a known anticorrosive, this was the first test of the fruit’s juice. The juice, which he reported adsorbed into the aluminum’s surface, contains a number of sugars. Gerengi posited that these react with aluminum to form an anticorrosive film on the metal’s surface.

 

The influence of date palm (Phoenix dactylifera L.) (PDL) fruit juice on 7075 type aluminum (AA7075) alloy in 3.5% NaCl solution was investigated by Tafel extrapolarization and electrochemical impedance spectroscopy. It was found that PDL fruit juice acted as a slightly cathodic inhibitor, and inhibition efficiencies increased with the increase of PDL fruit juice concentration. The adsorption of the inhibitor on the metal surface was found to obey the Temkin adsorption isotherm and has a physisorption mechanism.

 

Husnu Gerengi points out that strong, lightweight aluminum alloys are used to make planes, cars and industrial equipment. Aluminum corrodes when exposed to air, but unlike rusting steel, the corrosion of aluminum’s surface layer forms a protective film that prevents degradation of the underlying metal. However, that film breaks down in some harsh environments, like seawater, leaving the metal vulnerable. Engineers have developed coatings to protect aluminum in these applications, but many of these use potentially toxic chemicals. Previous research suggested that extracts of date palm leaves had an anti-corrosion effect. Gerengi decided to check date palm juice.


X-rays and Vincent Van Gogh’s Painting

With a sophisticated X-ray analysis scientists have identified why parts of the Van Gogh painting “Flowers in a blue vase” have changed colour over time: a supposedly protective varnish applied after the master’s death has made some bright yellow flowers turn to an orange-grey colour. The origin of this alteration is a hitherto unknown degradation process at the interface between paint and varnish, which studies at the European Synchrotron Radiation Facility ESRF in Grenoble (France) and at Deutsches Elektronen-Synchrotron DESY in Hamburg (Germany) have revealed for the first time.

The results are published in an upcoming issue of Analytical Chemistry, the first author of which is Geert Van der Snickt, who received a PhD in Conservation and Restauration from the University of Antwerp (Belgium) for this work. The research team was led by Koen Janssens from Antwerp and also comprised scientists from TU Delft (Netherlands), the French CNRS, the Kroller-Müller Museum in Otterlo (Netherlands), the ESRF and DESY.

The cadmium yellow (cadmium sulphide, CdS) used by Van Gogh was a relatively new pigment, of which it has recently been discovered that in unvarnished paintings, it oxidizes with air (to cadmium sulphate; CdSO4) making the pigments lose colour and luminosity. “We identified this process a few years ago, and the observation that instead of a slightly off-white, transparent oxidation layer, the pigments in this painting were covered with a dark, cracked crust intrigued us very much,” says Janssens. “The removal of the orange-grey crust and discoloured varnish was not possible without affecting the very fragile original cadmium yellow paint on these parts,” adds Leeuwestein.

To identify what had happened, the museum took two microscopic paint samples – each only a fraction of a millimetre in size – from the original painting and sent them to Janssens for a detailed investigation. The scientists studied the samples using powerful X-ray beams at the ESRF and at DESY’s PETRA III, revealing their chemical composition and internal structure at the interface between varnish and paint. To their surprise, they did not find the crystalline cadmium sulphate compounds that should have formed in the oxidation process. “It emerged that the sulphate anions had found a suitable reaction partner in lead ions from the varnish and had formed anglesite,” explains DESY scientist Gerald Falkenberg. Anglesite (PbSO4) is an opaque compound that was found nearly everywhere throughout the varnish. “The source of the lead probably is a lead-based siccative that had been added to the varnish,” adds Falkenberg.

UA scientists first to look at structure of vital molecule

Molybdenum plays critical roles in all living beings from bacteria to plants to humans. But as vital as this metal is, no one understood the importance of its structure until the Faculty of Medicine & Dentistry’s Joel Weiner and his team jumped on the case.

It does not act alone but is found attached to certain proteins, called molybdenum enzymes, by a very large organic molecule. The organic molecule that holds the molybdenum in place in a protein is extraordinarily complex. and “expensive” for the cell to make, b But the structure of this molecule should make sense to scientists now, thanks to Weiner and his research team.

For starters, the research group found that the molecule occurs in nature in two forms based on their appearance – flat or distorted. Weiner’s team was able to show that the distorted form and flat form have very different functions. The distorted molecule plays a role in the transfer of electrons to the molybdenum, whereas the flat molecule prepares and co-ordinates positioning of the enzyme so it can be part of a biochemical reaction.

The distorted form is found in proteins involved in metabolic, respiratory and cardiac diseases. The flat form occurs in a protein required for brain development, and defects in this protein cause death in infancy. Understanding of this flat form could help lead to treatment of this defect.

It all started for Weiner and his research group in the Department of Biochemistry about three years ago. Although scientists worldwide had known the overall structure of molybdenum in proteins for many years, no one understood why it is so complicated. It was a summer student, Matthew Solomonson, who noticed that one of the structures holding molybdenum was very flat while the other group was distorted. As curiosity-based research goes, the summer student and Weiner’s research team wondered if it was significant. The answer is yes.

“When you bring in a new student it’s really good because they have a fresh way of looking at things,” says Weiner of Solomonson who is now a grad student at the University of British Columbia.

Now the team will use protein-engineering techniques to change the protein environment around the molybdenum.

New catalyst to significantly reduce use of precious metals

Honda Motortoday announced the development of a new catalyst which reduces by 50% the use of rhodium, one of the precious metals used in a catalyst. Honda will adopt this new catalyst first to the North American version of the all-new 2013 Accord, which will go on sale in the United States on September 19, 2012, and will continue to adopt it sequentially to other models.

With the backdrop of the increasing volume of global automobile production and the global trend of strengthening emission regulations, the demand for precious metals used for catalyst, including platinum, rhodium and palladium, is expected to continue to increase in the future. Honda has been committed to the effort to reduce the use of precious metals for its catalysts, and has successfully applied a catalyst that does not contain any platinum into practical use with the current model of the North American Accord.

The newly developed catalyst allows palladium to speed up the process of absorption and desorption of oxygen, therefore enabling reduced use of rhodium in the purification of exhaust emissions. The adoption of this new catalyst will reduce overall use of precious metals by 22% (including a 50% reduction in rhodium) compared to the current model of Accord. Moreover, the development of the new catalyst has reduced the cost by 37% while complying with the California state standards in SULEV category of the LEV II regulation, which is one of the strictest emissions regulation in the world.

Ordinary Pen Ink Is Useful For Building A Supercapacitor

A research group in China has discovered that the ink in an ordinary pen makes for a good coating when building a supercapacitor. The team, from Peking University (Beijing National Laboratory for Molecular Sciences) describe in their paper published in Advanced Materials, how they used pen ink to coat carbon fibers as part of a process in creating a supercapacitor that was not only bendable but able to cover a large surface area.

Supercapacitors are energy storage devices that are able to be charged and more importantly, discharged much more quickly than conventional capacitors. They serve as a sort of bridge between conventional capacitors and batteries and are used in applications where a quick change in load is required, such as in balancing electrical grids. The focus of most ongoing research involving supercapacitors centers around trying to bring down costs. Most conventional systems use carbon to carbon electrodes or in some cases metal oxide electrodes, both of which tend to cost a lot. More recent research has focused on graphene or carbon nanotubes because of their unique electrical properties. This new research involved looking at ordinary pen ink after the researchers noted that many types of it just happen to contain carbon nanoparticles.

The researchers built the new supercapacitor by applying the pen ink to dual carbon fibers which were then encased, along with a spacer wire, in plastic and filled with a liquid conducting solution, i.e. an electrolyte. The result was a very thin (millimeter) diameter supercapacitor in the shape of a double wire cable, that could be bent to form a full circle and that could also cover a large area; one gram of ink produced enough of the supercapacitor cable to cover twenty seven square meters of material; all this with little to no loss in performance. They also point out that their supercapacitor is able to hold up to ten times more charge than comparable conventional supercapacitors and outperforms them as well.

Because of the unique properties of the supercapacitor they’ve made, the researchers believe it could be applied to cloth material which would result in wearable electronics such as sensors or even as components in future phones or other handheld devices.

Researchers Devise Simple and Cheap Method to Detect TB

Tuberculosis or TB as it’s become more commonly known, is a horrible disease by all accounts, it slowly kills many of its victims, particularly those living in the developing world. In 2010, it killed an estimated four thousand people every single day, which is particularly horrendous when noting that many of those who succumb to its effects could be have been saved were they to be diagnosed and treated in a timely manner.

Unfortunately, in many areas of the world neither is available, thus the news that a team of researchers working together from several universities in the US has developed a new kind of test that reveals the presence of TB in patients, both quickly and cheaply, is truly exciting. The new probe, as the team describes in their paper published in Nature Chemistry, can allow for TB detection using nothing more than a simple box housing light emitting diodes and some filters.

Up till now, the only way to test for TB in remote patients was to collect a sputum sample and send it to a location that had a microscope, where trained clinicians looked for the TB bacteria. Sadly, this method is not only slow, it’s also relatively inaccurate when there are few bacteria to be seen, such as is the case with infected children. With the new probe, test times can be reduced to mere minutes and accuracy is improved dramatically.

Reducing the amount of time it takes to test for TB not only helps the patient, it helps those around them too because TB is of course, communicable, with some estimating that one infected, untreated person may account for as many as ten or fifteen new infections in others in just one year.

Early diagnosis of tuberculosis can dramatically reduce both its transmission and the associated death rate. The extremely slow growth rate of the causative pathogen, Mycobacterium tuberculosis (Mtb), however, makes this challenging at the point of care, particularly in resource-limited settings. Here we report the use of BlaC (an enzyme naturally expressed/secreted by tubercle bacilli) as a marker and the design of BlaC-specific fluorogenic substrates as probes for Mtb detection. These probes showed an enhancement by 100–200 times in fluorescence emission on BlaC activation and a greater than 1,000-fold selectivity for BlaC over TEM-1 beta-lactamase, an important factor in reducing false-positive diagnoses.

Insight into the BlaC specificity was revealed by successful co-crystallization of the probe/enzyme mutant complex. A refined green fluorescent probe (CDG-OMe) enabled the successful detection of live pathogen in less than ten minutes, even in unprocessed human sputum. This system offers the opportunity for the rapid, accurate detection of very low numbers of Mtb for the clinical diagnosis of tuberculosis in sputum and other specimens.

Super Thin and Strong Graphene-based Circuits

Integrated circuits, which are in everything from coffeemakers to computers and are patterned from perfectly crystalline silicon, are quite thin—but Cornell researchers think they can push thin-film boundaries to the single-atom level.

Their materials of choice are graphene, single atom-thick sheets of repeating carbon atoms, and hexagonal boron nitride, similarly thin sheets of repeating boron and nitrogen atoms. Researchers led by Jiwoong Park, assistant professor of chemistry and chemical biology, have invented a way to pattern single atom films of graphene and boron nitride, an insulator, without the use of a silicon substrate. The work is detailed in an article in the journal Nature, published online Aug. 30.

The technique, which they call patterned regrowth, could lead to substrate-free, atomically thin circuits—so thin, they could float on water or through air, but with tensile strength and top-notch electrical performance.

As it turns out, researchers’ patterned regrowth, which harnesses the same basic photolithography technology used in silicon wafer processing, allows graphene and boron nitride to grow in perfectly flat, structurally smooth films—no creases or bumps, like a well-knitted scarf—which, if combined with the final, yet to be realized step of introducing a semiconductor material, could lead to the first atomically thin integrated circuit.

Simple really is beautiful, especially in the case of thin films, because photolithography is a well-established technique that forms the basis for making integrated circuits by laying materials, one layer at a time, on flat silicon.

The research team, which includes David A. Muller, professor of applied and engineering physics, is working to determine what material would best work with graphene boron nitride thin films to make up the final semiconducting layer that could turn the films into actual devices.

The team was helped by already being skilled at making graphene—still relatively new in the materials world—as well as Muller’s expertise in electron microscopy characterization at the nanoscale. Muller helped the team confirm that the lateral junctions of the two materials were, indeed, smooth and well connected.

Organocatalyst Splits Water

To facilitate the splitting of water, chemists usually use costly precious-metal catalysts deposited on electrodes. In one half of the electrochemical system, water is oxidized to liberate O2. In the other half, the protons generated can readily combine to give H2. The electricity needed to drive the overall reaction would ideally come from a solar cell.

Borrowing from biological systems, where metal-free, flavin-based enzymes are important catalysts for reduction and oxidation processes, a team led by Ksenija D. Glusac of Bowling Green State University has now shown that N-ethylflavinium ion catalytically oxidizes water to form O2. The researchers propose that O2 evolution occurs via formation of a flavin peroxide intermediate on the electrode surface, analogous to the mechanism of water oxidation with transition-metal oxide catalysts.

In the quest to find better catalysts for splitting water into oxygen and hydrogen, chemists have discovered that a small organic molecule related to the vitamin riboflavin (the CAS number is 83-88-5) can substitute for transition-metal catalysts traditionally used in electrolysis. The research, reported at the American Chemical Society national meeting in Philadelphia on Aug. 20, could lead to a simple, low-cost way to generate H2 to power fuel cells.

Speaking in the Division of Energy & Fuels, Glusac acknowledged that the flavinium catalyst has its limitations. The catalyst requires a high oxidation potential of 1.9 V, and it recycles only 13 times on average before becoming inactivated. But Glusac told C&EN she considers the flavinium ion a prototype.

“The water-oxidation reaction is of key importance to solar-fuel technology,” observes Thomas E. Mallouk, director of the Center for Solar Nanomaterials at Pennsylvania State University. “The discovery of a metal-free, molecular water-oxidation catalyst is unprecedented. Although the oxidation potential of this molecular catalyst is too high to be practical, the discovery suggests it may be possible to design more easily oxidized organic molecules to catalyze water oxidation.”