Thursday, October 31, 2013

Defective nanotubes turned into light emitters

Defective nanotubes turned into light emitters


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31-Oct-2013



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Contact: Aitziber Lasa
a.lasa@elhuyar.com
34-943-363-040
Elhuyar Fundazioa



UPV/EHU-University of the Basque Country researchers have developed and patented a new source of light emitter based on boron nitride nanotubes and suitable for developing high-efficiency optoelectronic devices



This news release is available in Spanish.


Scientists are usually after defect-free nano-structures. Yet in this case the UPV/EHU researcher Angel Rubio and his collaborators have put the structural defects in boron nitride nanotubes to maximum use. The outcome of his research is a new light-emitting source that can easily be incorporated into current microelectronics technology. The research has also resulted in a patent.

Boron nitride is a promising material in the field of nanotechnology, thanks to its excellent insulating properties, resistance and two-dimensional structure similar to graphene. And specifically, the properties of hexagonal boron nitride, the focus of this research, are far superior to those of other metals and semiconductors currently being used as light emitters, for example, in applications linked to optical storage (DVD) or communications. "It is extremely efficient in ultraviolet light emission, one of the best currently available on the market," remarked the UPV/EHU researcher Angel Rubio.

However, the light emission of boron nitride nanotubes takes place within a very limited range of the ultraviolet spectrum, which means they cannot be used in applications in which the emission needs to be produced within a broader range of frequencies and in a controlled way (for example in applications using visible light).

The research carried out by the UPV/EHU's NanoBio Spectroscopy Group has come up with a solution to overcome this limitation, and open up the door to the use of hexagonal boron nitride nanotubes in commercial applications.

They have shown that by applying an electric field perpendicular to the nanotube, it is possible to get the latter to emit light across the whole spectrum from the infrared to the far ultraviolet and to control it in a simple way. This ease of control is only to be found in nanotubes due to their cylindrical geometry (these are tubular structures with lengths in the order of micrometres, and diameters in the order of nanometres).

Rubio has been working with boron nitride nanotubes for nearly 20 years. "We proposed them theoretically, and then they were found experimentally. So far, all our theoretical predictions have been confirmed, and that is very gratifying," he explained. Once the properties of layered hexagonal boron nitride and its extremely high efficiency in light emission were known, this research sought to show that these properties are not lost in nanotubes. "We knew that when a sheet was rolled up and a tube was formed, a strong coupling was produced with the electric field and that would enable us to change the light emission. We wanted to show," and they did in fact show, "that light emission efficiency was not being lost due to the fact that the nanotube was formed, and that it is also controllable."

Boron absences

The device functions on the basis of the use of natural (or induced) defects in boron nitride nanotubes. In particular, the defects enabling controlled emission are the gaps that appear in the wall of the nanotube due to the absence of a boron atom, which is the most common defect in its manufacture. "All nanotubes are very similar, but the fact that you have these defects makes the system operational and efficient, and what is more, the more defects you have, the better it functions."

Rubio highlighted "the simplicity" of the device proposed. "It's a device that functions with defects, it does not have to be pure, and it's very easy to build and control." Nanotubes can be synthesised using standard methods in the scientific community for producing inorganic nanotubes; the structures synthesised as a result have natural defects, and it is possible to incorporate more if you want by means of simple, post-synthesis irradiation processes. "It has a traditional transistor configuration, and what we are proposing would work with current electronic devices," he stressed. The "less attractive" part, as specified by Rubio, is that boron nitride nanotubes are still only produced in very small quantities, and as yet there is no economically viable synthesis process on a commercial scale.

Beyond graphene

Rubio is in no doubt about the potential of the new materials based on two-dimensional systems, and specifically, of compounds that offer an alternative to graphene, like, for example, hexagonal boron nitride. Without prejudice to graphene, Rubio believes that the alternative field could have greater potential in the long term and needs to be explored: "It's a field that has been active for over the last fifteen years, even though it has been less visible. We have been working with hexagonal boron nitride since 1994, it's like our child, and I believe that it has opened up an attractive field of research, which more and more groups are joining."

###

Further information:

This research has been conducted by the NanoBio Spectroscopy Group (ETSF-Centre for Scientific Development, Department of Materials Physics, Faculty of Chemistry of the UPV/EHU), led by Prof ngel Rubio, in collaboration with Dr Ludger Wirtz (University of Luxembourg), Dr Claudi Attaccalite (University of Grenoble) and Dr Andrea Marini (CNR Italian Research Council - Rome), who are three veteran researchers in the group.

ngel Rubio is professor of Materials Physics of the UPV/EHU, head of the NanoBio Spectroscopy Group and Chairman of the ETSF-European Theoretical Spectroscopy Facility of the UPV/EHU, as well as external director of the Fritz Haber Institute of the Max Planck Society.




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Defective nanotubes turned into light emitters


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PUBLIC RELEASE DATE:

31-Oct-2013



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Contact: Aitziber Lasa
a.lasa@elhuyar.com
34-943-363-040
Elhuyar Fundazioa



UPV/EHU-University of the Basque Country researchers have developed and patented a new source of light emitter based on boron nitride nanotubes and suitable for developing high-efficiency optoelectronic devices



This news release is available in Spanish.


Scientists are usually after defect-free nano-structures. Yet in this case the UPV/EHU researcher Angel Rubio and his collaborators have put the structural defects in boron nitride nanotubes to maximum use. The outcome of his research is a new light-emitting source that can easily be incorporated into current microelectronics technology. The research has also resulted in a patent.

Boron nitride is a promising material in the field of nanotechnology, thanks to its excellent insulating properties, resistance and two-dimensional structure similar to graphene. And specifically, the properties of hexagonal boron nitride, the focus of this research, are far superior to those of other metals and semiconductors currently being used as light emitters, for example, in applications linked to optical storage (DVD) or communications. "It is extremely efficient in ultraviolet light emission, one of the best currently available on the market," remarked the UPV/EHU researcher Angel Rubio.

However, the light emission of boron nitride nanotubes takes place within a very limited range of the ultraviolet spectrum, which means they cannot be used in applications in which the emission needs to be produced within a broader range of frequencies and in a controlled way (for example in applications using visible light).

The research carried out by the UPV/EHU's NanoBio Spectroscopy Group has come up with a solution to overcome this limitation, and open up the door to the use of hexagonal boron nitride nanotubes in commercial applications.

They have shown that by applying an electric field perpendicular to the nanotube, it is possible to get the latter to emit light across the whole spectrum from the infrared to the far ultraviolet and to control it in a simple way. This ease of control is only to be found in nanotubes due to their cylindrical geometry (these are tubular structures with lengths in the order of micrometres, and diameters in the order of nanometres).

Rubio has been working with boron nitride nanotubes for nearly 20 years. "We proposed them theoretically, and then they were found experimentally. So far, all our theoretical predictions have been confirmed, and that is very gratifying," he explained. Once the properties of layered hexagonal boron nitride and its extremely high efficiency in light emission were known, this research sought to show that these properties are not lost in nanotubes. "We knew that when a sheet was rolled up and a tube was formed, a strong coupling was produced with the electric field and that would enable us to change the light emission. We wanted to show," and they did in fact show, "that light emission efficiency was not being lost due to the fact that the nanotube was formed, and that it is also controllable."

Boron absences

The device functions on the basis of the use of natural (or induced) defects in boron nitride nanotubes. In particular, the defects enabling controlled emission are the gaps that appear in the wall of the nanotube due to the absence of a boron atom, which is the most common defect in its manufacture. "All nanotubes are very similar, but the fact that you have these defects makes the system operational and efficient, and what is more, the more defects you have, the better it functions."

Rubio highlighted "the simplicity" of the device proposed. "It's a device that functions with defects, it does not have to be pure, and it's very easy to build and control." Nanotubes can be synthesised using standard methods in the scientific community for producing inorganic nanotubes; the structures synthesised as a result have natural defects, and it is possible to incorporate more if you want by means of simple, post-synthesis irradiation processes. "It has a traditional transistor configuration, and what we are proposing would work with current electronic devices," he stressed. The "less attractive" part, as specified by Rubio, is that boron nitride nanotubes are still only produced in very small quantities, and as yet there is no economically viable synthesis process on a commercial scale.

Beyond graphene

Rubio is in no doubt about the potential of the new materials based on two-dimensional systems, and specifically, of compounds that offer an alternative to graphene, like, for example, hexagonal boron nitride. Without prejudice to graphene, Rubio believes that the alternative field could have greater potential in the long term and needs to be explored: "It's a field that has been active for over the last fifteen years, even though it has been less visible. We have been working with hexagonal boron nitride since 1994, it's like our child, and I believe that it has opened up an attractive field of research, which more and more groups are joining."

###

Further information:

This research has been conducted by the NanoBio Spectroscopy Group (ETSF-Centre for Scientific Development, Department of Materials Physics, Faculty of Chemistry of the UPV/EHU), led by Prof ngel Rubio, in collaboration with Dr Ludger Wirtz (University of Luxembourg), Dr Claudi Attaccalite (University of Grenoble) and Dr Andrea Marini (CNR Italian Research Council - Rome), who are three veteran researchers in the group.

ngel Rubio is professor of Materials Physics of the UPV/EHU, head of the NanoBio Spectroscopy Group and Chairman of the ETSF-European Theoretical Spectroscopy Facility of the UPV/EHU, as well as external director of the Fritz Haber Institute of the Max Planck Society.




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Source: http://www.eurekalert.org/pub_releases/2013-10/ef-dnt103113.php
Category: Ed Lauter   new england patriots   Fantastic Beasts and Where to Find Them   iPhone 5S   usher  

NIH-funded scientists reveal structure of HIV protein key to cell entry

NIH-funded scientists reveal structure of HIV protein key to cell entry


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Contact: NIAID Office of Communications
niaidnews@niaid.nih.gov
301-402-1663
NIH/National Institute of Allergy and Infectious Diseases



Finding holds promise for HIV vaccine development





Using protein engineering and two different cutting-edge structural biology imaging techniques, researchers have developed a detailed picture of the protein largely responsible for enabling HIV to enter human immune cells and cause infection. An in-depth understanding of the atomic structure of the HIV envelope trimeror Env, the three-component protein found on HIV's surfaceis critical to better understanding how HIV gains entry into cells and for creating potential HIV vaccines.


Atomic-resolution imaging of the Env protein has previously been elusive because of the protein's complex, delicate structure. To capture the image, a team of scientists at The Scripps Research Institute and Weill Medical College of Cornell University engineered a more stable version of the protein. Then, in separate studies, using first cryo-electron microscopy and then X-ray crystallography, the researchers were able to reveal the structure of the Env trimer, how it assembles and how it interacts with broadly neutralizing antibodies that target HIV.


Their research, described in two papers published online today in Science Express, received major support from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.


###


ARTICLES:
D. Lyumkis et al. Cryo-EM Structure of a Fully Glycosylated Soluble Cleaved HIV-1 Env Trimer. Science Express DOI: 10.1126/science.1245627 (2013).


J.P. Julien et al. Crystal Structure of a Soluble Dleaved HIV-1 Envelope Trimer. Science Express DOI: 10.1126/science.1245625 (2013).



NIAID Director Anthony S. Fauci, M.D, is available to comment on both papers.



To schedule interviews, please contact the NIAID News Office, (301) 402-1663, niaidnews@niaid.nih.gov.


NIAID conducts and supports researchat NIH, throughout the United States, and worldwideto study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at http://www.niaid.nih.gov.


About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov/.



NIH...Turning Discovery Into Health




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NIH-funded scientists reveal structure of HIV protein key to cell entry


[ Back to EurekAlert! ]

PUBLIC RELEASE DATE:

31-Oct-2013



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Contact: NIAID Office of Communications
niaidnews@niaid.nih.gov
301-402-1663
NIH/National Institute of Allergy and Infectious Diseases



Finding holds promise for HIV vaccine development





Using protein engineering and two different cutting-edge structural biology imaging techniques, researchers have developed a detailed picture of the protein largely responsible for enabling HIV to enter human immune cells and cause infection. An in-depth understanding of the atomic structure of the HIV envelope trimeror Env, the three-component protein found on HIV's surfaceis critical to better understanding how HIV gains entry into cells and for creating potential HIV vaccines.


Atomic-resolution imaging of the Env protein has previously been elusive because of the protein's complex, delicate structure. To capture the image, a team of scientists at The Scripps Research Institute and Weill Medical College of Cornell University engineered a more stable version of the protein. Then, in separate studies, using first cryo-electron microscopy and then X-ray crystallography, the researchers were able to reveal the structure of the Env trimer, how it assembles and how it interacts with broadly neutralizing antibodies that target HIV.


Their research, described in two papers published online today in Science Express, received major support from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.


###


ARTICLES:
D. Lyumkis et al. Cryo-EM Structure of a Fully Glycosylated Soluble Cleaved HIV-1 Env Trimer. Science Express DOI: 10.1126/science.1245627 (2013).


J.P. Julien et al. Crystal Structure of a Soluble Dleaved HIV-1 Envelope Trimer. Science Express DOI: 10.1126/science.1245625 (2013).



NIAID Director Anthony S. Fauci, M.D, is available to comment on both papers.



To schedule interviews, please contact the NIAID News Office, (301) 402-1663, niaidnews@niaid.nih.gov.


NIAID conducts and supports researchat NIH, throughout the United States, and worldwideto study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at http://www.niaid.nih.gov.


About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov/.



NIH...Turning Discovery Into Health




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AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.




Source: http://www.eurekalert.org/pub_releases/2013-10/nioa-nsr103113.php
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Google announces the Nexus 5 with Android 4.4, on sale today for $349 (hands-on)

It's about time. The Google-backed and LG-manufactured Nexus 5 is now really a reality, after countless rumors and leaks (a few of them coming from Google itself). The new device, which predictably boasts the latest and greatest version of Android known as KitKat (or 4.4, if you're so inclined), ...


Source: http://feeds.engadget.com/~r/weblogsinc/engadget/~3/GmurxsZkcQU/
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FAA expands the use of portable electronics on planes

Portable electronics on planes

Airplane mode will still be required, and you'll have to pretend to pay attention to the safety briefing

The Federal Aviation Administration this morning at a news conference announced that (as expected) it has determined that portable electronic devices can be used not just above 10,000 feet, but during "all phases of flight." That means no more turning off your iPhones, iPads, e-books, e-readers, Game Boys, Kindles, BlackBerry, blueberry, strawberry — anything with an on/off switch that must be in the off position before the aircraft can push back from the gate.

You will, however, have to wait on the airlines to implement the FAA's guidance, which it expects to see happen by the end of the year.

read more


    






Source: http://feedproxy.google.com/~r/androidcentral/~3/o7EDDz35dEA/story01.htm
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Coursera teams up with State Department on series of MOOC-based 'learning hubs' around the world


Coursera teams up US State Department on series of MOOCbased 'learning hubs' around the world


Coursera is already one of the leading providers of MOOCs (or massive open online courses) in the US, and its now getting a helping hand from none other than the US government in broadening its worldwide ambitions. The company announced a new initiative today that will see it partner with the State Department and a number of other organizations on a series of "learning hubs" around the world, where students will be able to go and access the internet and participate in MOOCs as a group.


Those classes won't be quite as "massive" as your usual MOOC, however. According the The New York Times, the classes will all be small ones -- some with as few as 15 students -- and they'll be supplemented by weekly in-person sessions with a local instructor for what Coursera's Lila Ibrahim describes as a "blended learning experience." For its part, the State Department says that it hopes the courses will not only help students where they are, but "help connect them to U.S. higher education institutions" as well.


Source: http://www.engadget.com/2013/10/31/coursera-state-department-mooc-learning-hubs/?ncid=rss_truncated
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The NASA Engineer Who Made iPads the Future of Halloween

Two years ago, NASA engineer Mark Rober blew YouTube's mind with a video of his Halloween costume: a hole in his chest. Or at least it looked like a hole in his chest. In fact, it was an optical illusion made possible by two iPads, a little duct tape and a lot of ingenuity. Well, you won't believe what he's been up to since then.

Read more...


    






Source: http://feeds.gawker.com/~r/gizmodo/full/~3/KaTPzh5Ha6s/the-nasa-engineer-who-made-ipads-the-future-of-hallowee-1454314362
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MTV Artists iPhone app wants to help you discover new music, provide a deeper connection with musicians

The number of media discovery apps keeps getting bigger by the day, and the latest to join the frenzy is MTV. Simply dubbed MTV Artists, the newly announced iPhone application is loaded with a vast amount of music-focused features, including detailed artists pages and the ability to search for ...


Source: http://feeds.engadget.com/~r/weblogsinc/engadget/~3/fVtSuKfGM_g/
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