Scientists Capture First Images of Molecules Before and After Reaction

Every chemist’s dream – to snap an atomic-scale picture of a chemical before and after it reacts – has now come true, thanks to a new technique developed by chemists and physicists at the University of California, Berkeley.

Using a state-of-the-art atomic force microscope, the scientists have taken the first atom-by-atom pictures, including images of the chemical bonds between atoms, clearly depicting how a molecule’s structure changed during a reaction. Until now, scientists have only been able to infer this type of information from spectroscopic analysis.

 

Non-contact atomic force microscope (nc-AFM) images (center) of a molecule before and after a reaction improve immensely over images (top) from a scanning tunneling microscope and look just like the classic molecular structure diagrams (bottom). (Credit: Felix Fischer and Michael Crommie, UC Berkeley)

Credit: http://newscenter.berkeley.edu

Artificial Sweeteners May Do More Than Sweeten: It Can Affect How the Body Reacts to Glucose

Researchers at Washington University School of Medicine in St. Louis have found that a popular artificial sweetener can modify how the body handles sugar.

In a small study, the researchers analyzed the sweetener sucralose (Splenda®) in 17 severely obese people who do not have diabetes and don’t use artificial sweeteners regularly.

 

Sucralose artificial sweetener, a molecular model. (Credit: © molekuul.be / Fotolia)

Credit:  https://news.wustl.edu

Scientists Develop CO2 Sequestration Technique

Lawrence Livermore scientists have discovered and demonstrated a new technique to remove and store atmospheric carbon dioxide while generating carbon-negative hydrogen and producing alkalinity, which can be used to offset ocean acidification.

The team demonstrated, at a laboratory scale, a system that uses the acidity normally produced in saline water electrolysis to accelerate silicate mineral dissolution while producing hydrogen fuel and other gases. The resulting electrolyte solution was shown to be significantly elevated in hydroxide concentration that in turn proved strongly absorptive and retentive of atmospheric CO2.

 

The Great Barrier Reef in Australia already has been affected by ocean warming and acidification. (Credit: Image courtesy of DOE/Lawrence Livermore National Laboratory)

Credit: https://www.llnl.gov

Advanced Biological Computer Developed

As computing devices, which process data and interconvert information, transducers can encode new information and use their output for subsequent computing, offering high computational power that may be equivalent to a universal Turing machine.

Microprocessor with DNA (illustration). Scientists have developed and constructed an advanced biological transducer, a computing machine capable of manipulating genetic codes, and using the output as new input for subsequent computations (Credit: © Giovanni Cancemi / Fotolia)

Credit: http://www.sciencedirect.com

Chemists Find New Compounds to Curb Staph Infection

In an age when microbial pathogens are growing increasingly resistant to the conventional antibiotics used to tamp down infection, a team of Wisconsin scientists has synthesized a potent new class of compounds capable of curbing the bacteria that cause staph infections.

These assays were used to assess the effects of new agents to disrupt communication among pathogenic staph bacteria. Research shows promise for a new approach to thwarting staph infections, which are increasingly resistant to conventional antibiotics.
Photo courtesy of Blackwell Lab

Writing online in the Journal of the American Chemical Society, a group led by University of Wisconsin-Madison chemistry professor Helen Blackwell describes agents that effectively interfere with the "quorum sensing" behavior of Staphylococcus aureus, a bacterium at the root of a host of human infections ranging from acne to life-threatening conditions such as pneumonia, toxic shock syndrome and sepsis.

Credit: http://www.news.wisc.edu

Engineers Devise New Way to Produce Clean Hydrogen

Duke University engineers have developed a novel method for producing clean hydrogen, which could prove essential to weaning society off of fossil fuels and their environmental implications.

While hydrogen is ubiquitous in the environment, producing and collecting molecular hydrogen for transportation and industrial uses is expensive and complicated. 

Just as importantly, a byproduct of most current methods of producing hydrogen is carbon monoxide, which is toxic to humans and animals.

 

Nico Hotz, left, and Titilayo Shodiya. (Credit: Duke University Photography)

Credit: http://today.duke.edu

Nanoantennas Improve Infrared Sensing

A team of University of Pennsylvania engineers has used a pattern of nanoantennas to develop a new way of turning infrared light into mechanical action, opening the door to more sensitive infrared cameras and more compact chemical-analysis techniques.

The research was conducted by assistant professor Ertugrul Cubukcu and postdoctoral researcher Fei Yi, along with graduate students Hai Zhu and Jason C. Reed, all of the Department of Material Science and Engineering in Penn’s School of Engineering and Applied Science. 

A diagram showing how the researchers' optomechanical infrared-detecting structure works. (Credit: Image courtesy of University of Pennsylvania)

Credit: http://www.upenn.edu/

Add Boron for Better Batteries

Rice University theorists say graphene-boron mix shows promise for lithium-ion batteries 

Frustration led to revelation when Rice University scientists determined how graphene might be made useful for high-capacity batteries.

Calculations by the Rice lab of theoretical physicist Boris Yakobson found a graphene/boron anode should be able to hold a lot of lithium and perform at a proper voltage for use in lithium-ion batteries. The discovery appears in the American Chemical Society’s Journal of Physical Chemistry Letters.

 

A theory developed at Rice University determined that a graphene/boron compound would excel as an ultrathin anode for lithium-ion batteries. The compound would store far more energy than graphite electrodes used in current batteries. (Credit: Vasilii Artyukhov/Rice University)

Credit: http://news.rice.edu

World's Smallest Liquid Droplets Ever Made in the Lab, Experiment Suggests

Physicists may have created the smallest drops of liquid ever made in the lab.

That possibility has been raised by the results of a recent experiment conducted by Vanderbilt physicist Julia Velkovska and her colleagues at the Large Hadron Collider, the world’s largest and most powerful particle collider located at the European Laboratory for Nuclear and Particle Physics (CERN) in Switzerland. 

Evidence of the minuscule droplets was extracted from the results of colliding protons with lead ions at velocities approaching the speed of light.

A three-dimensional view of a p-Pb collision that produced collective flow behavior. The green lines are the trajectories of the sub-atomic particles produced by the collision reconstructed by the CMS tracking system. The red and blue bars represent the energy measured by the instrument's two sets of calorimeters. (Credit: CMS Collaboration)

 Credit: http://news.vanderbilt.edu

Artificial Forest for Solar Water-Splitting: First Fully Integrated Artificial Photosynthesis Nanosystem

In the wake of the sobering news that atmospheric carbon dioxide is now at its highest level in at least three million years, an important advance in the race to develop carbon-neutral renewable energy sources has been achieved. 

Scientists with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have reported the first fully integrated nanosystem for artificial photosynthesis. 

While “artificial leaf” is the popular term for such a system, the key to this success was an “artificial forest.”

Schematic shows TiO2 nanowires (blue) grown on the upper half of a Si nanowire (gray) and the two absorbing different regions of the solar spectrum. Insets display photoexcited electron hole pairs separated at the semiconductor-electrolyte interface to carry out water splitting with the help of co-catalysts (yellow and gray dots). (Credit: Image courtesy of DOE/Lawrence Berkeley National Laboratory)

Credit: http://newscenter.lbl.gov/

Harvard aims to help developers make cheaper solar panels

Harvard aims to help developers make cheaper solar panels

EHN Special Report: 'Chemicals of high concern' found in thousands of children's products — Environmental Health News

EHN Special Report: 'Chemicals of high concern' found in thousands of children's products — Environmental Health News

Cobalt in plastic building blocks and baby bibs. Ethylene glycol in dolls. Methyl ethyl ketone in clothing. Antimony in high chairs and booster seats. Parabens in baby wipes. D4 in baby creams. An Environmental Health News analysis of thousands of reports from America’s largest companies shows that toys and other children’s products contain low levels of dozens of industrial chemicals, including some unexpected ingredients that will surprise a public concerned about exposure. The reports were filed by 59 large companies, including Gap, Mattel, Gymboree, Nike, H&M and Wal-Mart, to comply with an unprecedented state law.

Observation of Second Sound in a Quantum Gas

Second sound is a quantum mechanical phenomenon, which has been observed only in superfluid helium. 

Physicists from the University of Innsbruck, Austria, in collaboration with colleagues from the University of Trento, Italy, have now proven the propagation of such a temperature wave in a quantum gas. 

The scientists have published their historic findings in the journal Nature.

 

The cigar-shaped particle cloud is locally heated with a power-modulated laser beam (green). (Credit: IQOQI/Ritsch)

Credit: http://www.alphagalileo.org

Scientists Uncover Fundamental Property of Astatine -- Rarest Naturally Occurring Element On Earth

An international team of scientists, including a University of York researcher, has carried out ground-breaking experiments to investigate the atomic structure of astatine (Z=85), the rarest naturally occurring element on Earth.

Astatine (At) is of significant interest as its decay properties make it an ideal short-range radiation source for targeted alpha therapy in cancer treatment.

Credit: http://www.alphagalileo.org

Chemists Demonstrate Nanoscale Alloys So Bright They Could Have Potential Medical Applications

PITTSBURGH—Alloys like bronze and steel have been transformational for centuries, yielding top-of-the-line machines necessary for industry. As scientists move toward nanotechnology, however, the focus has shifted toward creating alloys at the nanometer scale—producing materials with properties unlike their predecessors.

Now, research at the University of Pittsburgh demonstrates that nanometer-scale alloys possess the ability to emit light so bright they could have potential applications in medicine. 

The findings have been published in the Journal of the American Chemical Society.

 

Jill Millstone. (Credit: Image courtesy of University of Pittsburgh)

Credit: http://www.news.pitt.edu

New Advance in Biofuel Production

Advanced biofuels – liquid fuels synthesized from the sugars in cellulosic biomass – offer a clean, green and renewable alternative to gasoline, diesel and jet fuels. 

Bringing the costs of producing these advanced biofuels down to competitive levels with petrofuels, however, is a major challenge. Researchers at the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI), a bioenergy research center led by Berkeley Lab, have taken another step towards meeting this challenge with the development of a new technique for pre-treating cellulosic biomass with ionic liquids – salts that are liquids rather than crystals at room temperature. 

This new technique requires none of the expensive enzymes used in previous ionic liquid pretreatments, and makes it easier to recover fuel sugars and recycle the ionic liquid.

Ning Sun of the Joint BioEnergy Institute was lead author on a paper describing an enzyme-free ionic liquid pretreatment of biomass that can help boost the production of advanced biofuels. (Photo by Roy Kaltschmidt)

Credit:  Joint BioEnergy Institute Researchers Develop Enzyme-free Ionic Liquid Pre-treatment

Perfectly Doped Quantum Dots Yield 'Colors to Dye For'

Quantum dots are tiny nanocrystals with extraordinary optical and electrical properties with possible uses in dye production, bioimaging, and solar energy production. 

Researchers at the University of Illinois at Chicago have developed a way to introduce precisely four copper ions into each and every quantum dot.

The introduction of these “guest” ions, called doping, opens up possibilities for fine-tuning the optical properties of the quantum dots and producing spectacular colors.

 

Quantum Dots doped with copper. (Credit: Image courtesy of University of Illinois at Chicago)

Credit: http://news.uic.edu

New Magnetic Graphene May Revolutionize Electronics

Researchers from IMDEA-Nanociencia Institute and from Autonoma and Complutense Universities of Madrid (Spain) have managed to give graphene magnetic properties. 

The breakthrough, published in the journal 'Nature Physics', opens the door to the development of graphene-based spintronic devices, that is, devices based on the spin or rotation of the electron, and could transform the electronics industry.

Scientists were already aware that graphene, an incredible material formed of a mesh of hexagonal carbon atoms, has extraordinary conductivity, mechanical and optical properties. 

Now it is possible to give it yet one more property: magnetism, implying a breakthrough in electronics.

 

Computerised simulation of TCNQ molecules on graphene layer, where they acquire a magnetic order. (Credit: IMDEA-Nanoscience)

Credit: http://www.alphagalileo.org

Exotic Atoms Hold Clues to Unsolved Physics Puzzle at the Dawn of the Universe

ANN ARBOR—An international team of physicists has found the first direct evidence of pear shaped nuclei in exotic atoms.

 

The findings could advance the search for a new fundamental force in nature that could explain why the Big Bang created more matter than antimatter—a pivotal imbalance in the history of everything.

Read more here. 

A graphical representation of the pear-shaped nucleus of an exotic atom. The shape of the nucleus could give clues to why the universe contains more matter than antimatter. Image credit: Liam Gaffney and Peter Butler, University of Liverpool

Credit:  University of Michigan,News Service

Colligative Properties

Physical properties can be divided into two categories. Extensive properties (such as mass and volume) depend on the size of the sample. Intensive properties (such as density and concentration) are characteristic properties of the substance; they do not depend on the size of the sample being studied. 

This section introduces a third category that is a subset of the intensive properties of a system. This third category, known as colligative properties, can only be applied to solutions. By definition, one of the properties of a solution is a colligative property if it depends only on the ratio of the number of particles of solute and solvent in the solution, not the identity of the solute. 

Very few of the physical properties of a solution are colligative properties. As an example of this limited set of physical properties, let's consider what happens to the vapor pressure of the solvent when we add a solute to form a solution. We'll define P^o as the vapor pressure of the pure liquid the solvent and P as the vapor pressure of the solvent after a solute has been added. 

Read more here. 

Credit: http://chemed.chem.purdue.edu

Poison lips? Troubling levels of toxic metals found in cosmetics

Poison lips? Troubling levels of toxic metals found in cosmetics

People may be adding a bit more than a touch of color to their lips, according to a new UC Berkeley study. (iStock)

What is Thermodynamics?

Thermodynamics is a branch of physics which deals with the energy and work of a system. It was born in the 19th century as scientists were first discovering how to build and operate steam engines. Thermodynamics deals only with the large scale response of a system which we can observe and measure in experiments. Small scale gas interactions are described by the kinetictheory of gases. The methods complement each other; some principles are more easily understood in terms of thermodynamics and some principles are more easily explained by kinetic theory. 

Credit: http://www.grc.nasa.gov

Flavonoids

• Flavonoids are polyphenolic compounds that are ubiquitous in nature and are categorized, according to chemical structure, into flavonols, flavones, flavanones, isoflavones, catechins, anthocyanidins and chalcones. 
• Over 4,000 flavonoids have been identified, many of which occur in fruits, vegetables and beverages (tea, coffee, beer, wine and fruit drinks). 
• The flavonoids have aroused considerable interest recently because of their potential beneficial effects on human health-they have been reported to have antiviral, anti-allergic, antiplatelet, anti-inflammatory, antitumor and antioxidant activities. 
  

Credit: Linus Pauling Institute.