You selected: Chemistry
Anyone who has ever worked in a laboratory has seen them: magnetic stirrers that rotate magnetic stir bars in liquids to mix them. The stir bars come in many different forms—now including nanometer-sized. In the journal Angewandte Chemie, researchers from Singapore have now introduced chains made of 40 nm iron oxide particles that act as the world’s smallest magnetic stir bars, effectively stirring picoliter-sized drops of emulsion with a commercial magnetic stirrer.
Dr. James Milne has been appointed to the position of Publishing Director, Physical Sciences
John Wiley & Sons, Inc., today announced a continued increase in the proportion of its journal titles indexed in the Thomson Reuters® 2012 Journal Citation Reports (JCR), with 1,192 (approximately 77%) titles now indexed, up from 1,156 in the 2011 JCR. Wiley titles now account for the largest share of journals in 50 categories.
Anthrax Killer from the Sea: Unusual antibiotic from a marine actinomycete is effective against anthrax
A new potential drug from a marine microorganism is effective against anthrax and various other Gram-positive bacteria, as reported by American scientists in the journal Angewandte Chemie. A chlorinated analogue kills off Gram-negative bacteria.
Drinking Water from the Sea: Electrochemically mediated seawater desalination in microfluidic systems
A new method for the desalination of sea water has been reported by a team of American and German researchers in the journal Angewandte Chemie. In contrast to conventional methods, this technique consumes little energy and is very simple. This electrochemically mediated seawater desalination is based on a system of microchannels and a bipolar electrode.
Author Richard Albright examines both the military’s policies towards the Chesapeake Bay and its uses of the Bay.
Ullmann's Renewable Resources
Ullmann's Reaction Engineering, 2 Volume Set
Industrial Biotechnology: Upstream Fermentation, Downstream Recovery and Purification, 3V set
Jackets with built-in mobile phones, sports clothes that warn you when your heart rate gets too high, wallpaper with glowing patterns—these are not concepts from a science fiction movie, some of them are actually already available, and they may soon become commonplace. These applications require electrically conductive fibrous materials. Korean researchers have now developed a new process for rendering paper and textile fibers conductive with aluminum. Their report appears in the journal Angewandte Chemie.
Polymer brushes are polymers in which individual polymer chains stand side by side on a surface, causing the chains to stick out like bristles on a brush. In the journal Angewandte Chemie, American scientists have now presented a new simple method for making three-dimensional nanostructures in a controlled fashion from polymer brushes.
In the human body, lipids do not only serve as energy stores and structural elements, but they are also important signaling molecules. Disruptions of lipid signal transmission seem to be involved in diseases such as atherosclerosis and diabetes, as well as inflammation and pain. In the journal Angewandte Chemie, researchers from Heidelberg have now reported on photoactivatable lipids that can be used to manipulate signaling processes in cells with both spatial and time resolution.
The Fastest and the Brightest: BODIPY–tetrazine derivatives as superbright bioorthogonal turn-on probes
American researchers have developed a probe for marking biomolecules that begins to fluoresce only when it is “switched on” by binding. As reported in the journal Angewandte Chemie, the reaction takes place very quickly and the difference in brightness between the “on” and “off” states is two orders of magnitude bigger than for conventional activatable probes.
Making Colors from Black and White: Colorfast pigments made from amorphous arrays of silicon dioxide and carbon black
It is very annoying when colors fade over time, sometimes simply from exposure to light. In the journal Angewandte Chemie, Japanese scientists have now introduced a new type of colorfast, environmentally friendly pigment. These consist of submicrometer-sized silicon dioxide particles and carbon black and are simply sprayed on to the desire surface. The resulting color is tough and does not fade.
A new process for generating nanometer-scale oil droplets in water has been reported in the journal Angewandte Chemie by Japanese researchers, who have developed a technique they named MAGIQ (monodisperse nanodroplet generation in quenched hydrothermal solution). Under standard conditions, hydrocarbons and water do not mix; however, at high temperatures and high pressures near the critical point of water, they freely mix. Quenching homogeneous solutions of dodecane and water under these conditions in the presence of a detergent produces nanoemulsions in just ten seconds.
Catalyst Keeps Fruit Fresh Longer: Even at low temperatures, platinum nanoparticles on a support catalyze breakdown of ethylene
Ripening fruit, vegetables, and flowers release ethylene, which works as a plant hormone. Ethylene accelerates ripening, so other unripened fruit also begins to ripen—fruit and vegetables quickly spoil and flowers wilt. In the journal Angewandte Chemie, Japanese researchers have now introduced a new catalytic system for the fast and complete degradation of ethylene. This system could keep the air in warehouses ethylene-free, keeping perishable products fresh longer.
CO2 for Chemical Synthesis: Universal method for the catalytic methylation of amines with carbon dioxide
Carbon dioxide is the most common source of carbon in nature and an inexpensive building block that is useful for the chemical industry. However, because of its high stability, it is not easy to induce CO2 to react. In the journal Angewandte Chemie, German scientists have now reported a universally applicable method for the catalytic methylation of amines with CO2.
Separation by Milling: Separation of dicarboxylic acids through molecular recognition and mechanochemistry
How does one separate a mixture of components with very similar properties? In the journal Angewandte Chemie, Croatian researchers have introduced a new approach to the separation of organic compounds. In their process, a “host compound” recognizes the desired “guest molecules”, not only in solution, but also when the host and mixtures of competitive guest are milled together in the solid state. For the separation of maleic acid, this recognition through mechanochemistry delivers selectivity equal to that achieved by crystallization from a solution.
Changes in the bases that make up DNA act as markers, telling a cell which genes it should read and which it shouldn’t. In the journal Angewandte Chemie, a British team has now introduced a new method that makes it possible to enrich the rare gene segments that contain the modified base hydroxymethylcytosine and to identify individual hydroxymethylcytosine molecules in DNA. Such modifications are associated with autoimmune diseases and cancer.
“Salted” Catalysts for Chemical Energy Storage: Basic alkali–metal salts improve a catalyst for steam reforming of methanol
The storage of hydrogen in the form of methanol is a highly promising method for using excess energy produced by wind and solar power plants. However, this technology requires an effective catalyst for regenerating the hydrogen. German scientists have now introduced a new platinum catalyst for this reaction, known as the steam reforming of methanol, in the journal Angewandte Chemie. The secret of their success lies in a special coating made from molten basic alkali metal salts.
From: Drug Testing and Analysis