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News Article
Site: http://www.rdmag.com/rss-feeds/all/rss.xml/all

Even the most practiced performers experience anxiety on the stage. Empirical evidence suggests that having an audience can have either facilitative or detrimental effects on a performance. Now, neuroscientists from the Univ. of Sussex have identified the brain network system responsible for anxious flubs and stumbles. Using functional magnetic resonance neuroimaging (fMRI), the team observed the brains of people carrying out an activity. The task—which required study participants to exert a precise amount of force when gripping an object—was performed while the participant viewed video footage. “The presence or absence of social evaluation was experimentally manipulated by presenting each participant with video footage of two observers who appeared to be closely evaluating the participant’s own task performance in real-time (observed condition) or that of another participant (unobserved condition),” the researchers wrote in Scientific Reports. “We predicted that the observed condition would elicit a mild level of anxiety in our participants.” Participants, according to the researchers, reported heightened levels of anxiety when they perceived that they were being viewed. It caused them to grip the objects harder. Brain scans of the participants showed that the area of the brain responsible for fine sensorimotor functions—the inferior parietal cortex (IPC)—was deactivated when participants believed they were being viewed. The IPC works with the brain’s posterior superior temporal sulcus (pSTS) to create the action-observation network, which humans use to infer what other people are thinking based on gaze and facial expressions. According to Dr. Michiko Yoshie, the action-observation network could be related to performance anxiety, as people tend to care what others think of their performance. “Our data suggest that social evaluation can vary force output through the altered engagement of (the IPC); a region implicated in sensorimotor integration necessary for object manipulation, and a component of the action-observation network which integrates and facilitates performance of observed actions,” the researchers write. While this information may not directly help people overcome social anxiety, Yoshie said there are brain stimulation techniques that can help activate desired behavior, such as transcranial magnetic stimulation and transcranial direct current stimulation.


News Article
Site: http://phys.org/chemistry-news/

Crystals of kryptonite, a material deadly to Superman and his race, were supposed to have been created within the planet Krypton, most likely under very high pressure. The planet's name is derived from the element krypton, with the atomic number of 36, a noble gas considered to be incapable of forming stable chemical compounds. However, a publication in the journal Scientific Reports by a two-man team of theoretical chemists from the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC PAS) in Warsaw, Poland, predict the synthesis of a new crystalline material in which atoms of krypton would be chemically bonded to another element. "The substance we are predicting is a compound of krypton with oxygen, not nitrogen. In the convention of the comic book it should, therefore, be called 'kryptoxide,' not 'kryptonite.' So if Superman's reading this, he can stay calm—at the moment, there's no cause for panic," says Dr. Patrick Zaleski-Ejgierd (IPC PAS). "Our krypton monoxide, KrO, probably does not exist in nature. According to current knowledge, the deep interiors of planets are the only place where there is sufficient pressure for its synthesis. Oxygen does not exist there, nor does krypton." Compounds of krypton have been produced in the laboratory under cryogenic conditions. They were, however, only single, linear and small molecules of the hydrogen-carbon-krypton-carbon-hydrogen type. The Polish chemists wondered if there were conditions in which krypton would not only bond chemically with another element, but also in which it would be capable of forming an extensive and stable crystal lattice. Their search, funded by an OPUS grant from the Polish National Science Centre, involved using genetic algorithms and models built on the so-called density functional theory. In the field of solid-state physics, this theory is a basic tool for the description and study of the world of chemical molecules. "Our computer simulations suggest that crystals of krypton monoxide will be formed at a pressure in the range of 300 to 500 million atmospheres. This is a high pressure, but it can be achieved even in today's laboratories, by skillfully squeezing samples in diamond anvils," says Ph.D. student Pawel M. Lata (IPC PAS). Crystal lattices are built from atoms or molecules arranged in space in an orderly manner. The smallest repetitive fragment of such structures, the basic 'building block,' is called a unit cell. In crystals of table salt, the unit cell has the shape of a cube in which the sodium and chlorine atoms, arranged alternately, are mounted on each corner, close enough to each other that they are bound by covalent (chemical) bonds. The unit cell of krypton monoxide is cuboid with a diamond base, with krypton atoms at the corners. In addition, in the middle of the two opposite side walls, there is one atom of krypton. "Where is the oxygen? On the side walls of the unit cell, where there are five atoms of krypton, they are arranged like the dots on a dice showing the number five. Single atoms of oxygen are located between the krypton atoms, but only along the diagonal—and only along one. Thus, on each wall with five krypton atoms, there are only two atoms of oxygen. Not only that, the oxygen is not exactly on the diagonal: One of the atoms is slightly offset from it in one direction and the other atom in the other direction," says Lata. In such an idiosyncratic unit cell, each atom of oxygen is chemically bound to the two nearest adjacent atoms of krypton. Zigzag chains of Kr/OKrO/Kr will therefore pass through the crystal of krypton monoxide, forming long polymer structures. Calculations indicate that crystals of this type of krypton monoxide should have the characteristics of a semiconductor. One can assume that they will be dark, and their transparency will not be great. Theorists from the IPC PAS have also found a second, slightly less stable compound of krypton: the tetroxide KrO . This material, which probably has properties typical of a metal, has a simpler crystalline structure and could be formed at a pressure exceeding 340 million atmospheres. After formation, the two kinds of krypton oxide crystals could probably exist at a somewhat lower pressure than that required for their formation. The pressure on earth, however, is so low that on our planet these crystals would undergo degradation immediately. "Reactions occurring at extremely high pressure are almost unknown, very, very exotic chemistry. We call it 'Chemistry on the Edge.' Often, the pressures needed to perform syntheses are so gigantic that at present, there is no point in trying to produce them in laboratories. In those cases, even methods of theoretic description fail! But what is most interesting here is the non-intuitiveness. From the very first to the last step of synthesis you never know what's going to happen," says Dr. Zaleski-Ejgierd. Explore further: On titanium oxide catalyst, certain atoms and molecules flee when light appears More information: Patryk Zaleski-Ejgierd et al. Krypton oxides under pressure, Scientific Reports (2016). DOI: 10.1038/srep18938


News Article | March 30, 2016
Site: http://www.techtimes.com/rss/sections/smartphone.xml

Ringing Bells Pvt. Ltd. continues to be indignant about its flagship Freedom 251 device despite various accusations from different parties. Earlier controversies that surrounded the release of the $4 Freedom 251 smartphone include rebranded Adcom smartphones distributed to media personnel during the phone's debut and the company's rather ambiguous and vague way of explaining how their phones can be priced so cheaply, not to menion their company is in the government's Make in India initiative. Now, a first information report (FIR) has been filed against Ringing Bells by Kirit Somaiya, leader of Bharatiya Janata Party (BJP) in India. The complaint accuses Ringing Bells of "cheating" as the company is allegedly violating Section 420 of the Indian Penal Code (IPC) and the Information Technology (IT) Acts. Somaiya believes the pricing of the phone is just not realistic and is accusing the company of committing fraud. The given specifications and features of the phone greatly exceed the selling price of the Freedom 251. Officials are assembling a team to investigate the matter after an initial report found the FIR had enough grounds to proceed. Ringing Bells has been required to submit documents for the inquiries pointed out in the FIR. The company states it is willing to oblige and it is in full cooperation with any government officials who need clarification from their side. Ringing Bells is seemingly ready to face and disprove any accusation. The company has also previously changed the mode of payments for preorders to a cash-on-delivery basis to further legitimize their business. Payments that had already been made were refunded. Such payments had been made through 3rd party banks and were held in escrow. In spite of these allegations directed at the company, not including all the assumptions and negative publicity, Ringing Bells seems unfazed. It promises to release the first batch of phones that will be delivered to users by the end of June 2016. Candidates were picked on a first come, first served basis and a status update on their company's Facebook page announced that they had sent out texts and e-mails to the users who had been picked. An estimated 50 lakh or 5 million units of the smartphone are expected to be sold both online and offline.


News Article
Site: http://phys.org/chemistry-news/

When you squeeze something, you usually expect it to shrink, particularly when the pressure exerted acts uniformly from all sides. However, there are materials which, when subjected to hydrostatic pressure, elongate slightly in one or two directions. During the search for optimal compounds for hydrogen storage, researchers made an accidental, albeit very interesting, discovery: Under increasing pressure, one of the tested materials elongated significantly. "Usually, the increase in dimensions observed in materials with negative compressibility subjected to high hydrostatic pressure is small. We are talking here about values of the order of a single percentage point or even less. We have found a material of very high negative compressibility, of up to 10% in one direction. Interestingly, the elongation occurred abruptly at a pressure of approx. 30 thousand atmospheres," says Dr. Taras Palasyuk (IPC PAS). Dr. Palasyuk is conducting research on materials subjected to hydrostatic pressures of one to several million atmospheres (the prefix hydro- means that the pressure acts on the material from all sides). Such high pressures are produced in the laboratory using diamond anvils, between which a micrometre-sized sample is placed. The sample is in a seal ensuring that the exerted pressure acts on the test material uniformly from all directions. To lead to an increase in pressure, the anvils are compressed by means of a screw. A ruby crystal placed next to the sample acts as a pressure gauge. It changes its mode of fluorescence depending on the pressure exerted upon it. The volume of the material samples exposed to increasing pressure decreases, which is usually associated with a reduction of all spatial dimensions. However, there are also atypical crystalline materials whose volume decreases during compression (because thermodynamics dictates that it must) while at the same time, the crystal elongates in one or two directions. The mechanism responsible for this elongation has always been of a geometric nature: Under pressure, individual elements of the crystal structure simply moved relative to each other to varying degrees in different directions. "In our laboratory, using laser light, we analyzed how the manners of vibration of molecules in the crystal changed with increasing pressure, and on this basis, we drew conclusions about the structure of the material. We quickly discovered that in the crystal we were examining, which was sodium amidoborane, the elongation could not be explained by changes in geometry alone," says Ph.D. student Ewelina Magos-Palasyuk, the lead author of the publication in the journal Scientific Reports. Sodium amidoborane is a relatively readily available compound with the chemical formula Na(NH BH ) forming transparent crystals with an orthorhombic structure. The results of research on crystals of this compound obtained at the IPC PAS using Raman spectroscopy were confronted with theoretical model predictions. It turned out that the negative compressibility of sodium amidoborane crystals has to be a consequence of the elongation of the chemical bonds between nitrogen, hydrogen, boron and nitrogen, caused by the abrupt formation of new hydrogen bonds between adjacent molecules in the crystal. "Sodium amidoborane is thus the first material known to us where the negative compressibility is primarily of a chemical nature," says Dr. Taras Palasyuk, stressing that in contrast to other materials in which the symmetry of the crystal structure changes under high pressure, there are no drastic changes in sodium amidoborane. He adds: "Our preliminary results, obtained by X-ray diffraction at the National Synchrotron Radiation Research Center in Taiwan, also confirm that the material retains its original symmetry. It is precisely because it does not have to rebuild that the increase in the linear dimensions occurs here in such an abrupt manner." The discovery of a previously unknown mechanism responsible for negative compressibility opens up interesting avenues in the search for new materials with similarly exotic physical properties. The significant, abrupt and reversible increase in length of the sodium amidoborane crystals at a clearly defined value of pressure makes the material an interesting candidate for such applications as components of pressure detectors of a threshold pressure of around 30 thousand atmospheres (in industry, pressures as high as 300 thousand atmospheres are used). Another potential application of sodium amidoborane could be active bulletproof vests, which would behave like airbags in a car under the influence of the sharp increase in pressure caused by the projectile strike. Explore further: Superman can start worrying—we've almost got the formula for kryptonite More information: Ewelina Magos-Palasyuk et al, Chemically driven negative linear compressibility in sodium amidoborane, Na(NH BH ), Scientific Reports (2016). DOI: 10.1038/srep28745


News Article
Site: http://phys.org/chemistry-news/

At first sight, it's difficult to resist the impression that they've been designed by an engineer-perfectionist, and not nature itself. Nanocscale cubosomes have a shape that is generally cubic, riddled with holes as regular as windows in a block of flats. The sizes of cubosomes range from tens to hundreds of nanometres. So far, they have been studied mainly using electron microscopes, which made it possible to describe their external shape. However, none of the currently available experimental techniques have penetrated in detail the interior of these remarkable structures. "Where the experimenter cannot go, he sends the theorist. An effective way to see inside cubosomes proved to be theoretical modelling using computers. Our numerical calculations revealed that the internal structure of cubosomes may be much more complex than originally thought," says Dr. Wojciech Gozdz from the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC PAS) in Warsaw. Cubosomes are similar in structure to crystals—like crystals, cubosomes express a repeating basic building block, referred to as the unit cell, which can be distinguished. However, that's where the similarity ends. In crystals, the unit cell consists of a group of typical and always equally spaced atoms or molecules, whereas in cubosomes it is a section of appropriately formed membrane immersed in water. "Cubosomes can be constructed from a variety of unit cells corresponding to different cubic structures. A single cubosome composed of such single cells somewhat resembles a sponge. Sponges, however, have a chaotic internal structure, whilst in cubosomes it is very, very regular," says Dr. Gozdz, adding, "A cubosome can be imagined as a closed surface. A simple example of a closed surface is a torus. However, in a torus there is only one hole, while in cubosomes, there are typically from several tens to several thousands of holes." Under the appropriate conditions and employing the appropriate experimental procedures, cubosomes form in a liquid medium containing amphiphilic molecules—that is, molecules in which one end is hydrophobic (water aversive), and the other is hydrophilic (water attractive). In water, amphiphilic molecules can form a double layer (bilayer) constructed in such a way that the hydrophilic ends are on the outside of the layer and the hydrophobic ends are directed towards its centre. Cubosomes can also be formed in ternary liquids, consisting of water, oil and amphiphilic molecules. The molecules then form not bilayers but monolayers, with their hydrophilic ends directed towards the water and hydrophobic ends toward the oil. The three-dimensional membrane creating each cubosome is closed and riddled with a regular network of tunnels. The tunnels are filled with the liquid in which the cubosome is immersed. If the solution in which the cubosome developed was two-component, the space in the cubosome enclosed by the membrane will be filled with the same liquid (in a ternary solution it would be a liquid other than that in the tunnels). Therefore, each cubosome can also be treated as a regular, three-dimensional grid of channels filled with a liquid (or two liquids). Thus perceived, the cubosome becomes a crystalline structure formed of liquid 'bars' surrounded by amphiphilic molecules. In his research, Dr. Gozdz focused on cubosomes made of bilayers, since such systems have been studied experimentally and in the future, may have many uses as drug delivery vehicles. Earlier, attempts to describe the shape of nanoparticles of this type used artificially matched mathematical functions. At the IPC PAS, a model built on physical equations has been used for first time to investigate the structure of cubosomes. The results of numerical calculations have led to some interesting discoveries. "We noticed, for example, that the size of the unit cell in cubosomes may be different from the size of the single unit cell in the solution. Indeed, cubosomes may swell or shrink in order for the resulting structure to have the least energy. If the size of the unit cell inside the cubosome remains the same as in the solution, then the cells adjacent to the walls of the cubosome may be significantly deformed," says Dr. Gozdz. The research at the IPC PAS has led to an even more surprising conclusion. Two cubosomes that are virtually identical externally can have a greatly varying internal structure. This observation is of important practical value due to one of the most important potential applications of cubosomes: the delivery of drugs in the body. Currently, liposomes are used for this purpose (these are spherical vesicles whose membrane is formed by a lipid bilayer). Compared to liposomes, cubosomes have a much richer, less uniform internal structure. A drug introduced into the cubosome's three-dimensional network of channels would be released for a longer period of time and in more precisely controlled doses. Therefore, the ability to change the internal structure of cubosomes without exerting a significant influence on their exterior dimensions and shapes, discovered at the IPC PAS, opens the way to precise manipulation of the rate of release of drugs. Explore further: Molecular motors: Power much less than expected?

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