viernes, 30 de noviembre de 2012

Avances en tratamientos del cáncer.

Metal nanoparticles may improve cancer treatment.
November 30, 2012 

Metal nanoparticles may improve cancer treatment


The research team developed a detector to measure the radiation dose in three dimensions. Research led by RMIT University has shown that cheap, non-toxic nanoparticles can enhance radiotherapy treatments for cancer. An international team of researchers led by RMIT has investigated alternatives to gold nanoparticles, which have been shown to concentrate radiation used to treat cancer but are highly expensive and mildly toxic. Doctoral researcher Mamdooh Alqathami said the team had identified bismuth as an ideal option, with tests showing that enhancing radiotherapy by using nanoparticles containing the heavy metal almost doubled the dose of radiation to surrounding cancerous tissue. "By enhancing radiation in the tumour, doctors may be able to decrease the initial dose of radiotherapy, which will hopefully result in fewer side effects for the patient while having the same impact on the cancer," Mr Alqathami, a researcher in the School of Medical Sciences, said. "Metal nanoparticles have shown promise in improving the efficacy of radiotherapy but there is a need to find cheaper and safer alternatives for therapeutic use. "Bismuth-based nanoparticles are an attractive option as they cost only a few dollars per gram, compared with thousands of dollars a gram for gold, and they are non-toxic, reducing any side effects from potential treatments. "While further work needs to be done before our findings can be implemented into conventional cancer treatments, this is an exciting advance that gives us a promising focus for ongoing research." Mr Alqathami collaborated with researchers from RMIT's Health Innovations Research Institute, the University of Melbourne, the University of Surrey (UK) and the Institute of Cancer Research (UK) on the study. To test the efficacy of bismuth, Mr Alqathami placed the nanoparticles inside a detector developed by his team to measure the radiation dose in three dimensions. The sample and detector was exposed to radiation that would normally be used to treat cancers. The final dose delivered was then compared with normal treatments, showing the bismuth-based nanoparticles increased the radiation dose by 90 per cent. The team is planning further tests to validate the findings and fully understand the dosage increase, to enable the findings to be implemented in cancer treatment. This research was presented at the International Conference on 3D Radiation Dosimetery recently held in Sydney. Provided by RMIT University 

Fullerenos como contenedores


Molecules ‘quantum rattle’ in buckyball cage

"Under these conditions, the confined molecules reveal a wave-like nature and behave according to the laws of quantum mechanics," says University of Southampton Professor Malcolm Levitt. "Apart from their intrinsic interest, we expect that the special properties of these materials will lead to a variety of applications, such as new ways to brighten the images of MRI scans, and new types of computer memory."Photo by: Credit: Hajv1/Wikimedia Commons
The nano-meter sized cavity of the hollow spherical C60 Buckminsterfullerene—or buckyball—effectively creates a “nanolaboratory,” allowing detailed study of the quantum mechanical principles that determine the motion of the caged molecule, including the mysterious wave-like behavior that is a fundamental property of all matter.
Experiments by the international team of researchers, including physicists from the University of Nottingham, have revealed the wave-like behavior and show how the imprisoned H2 and H2O molecules ‘quantum rattle’ in their cage.

Straight from the Source

DOI: 10.1073/pnas.1210790109
Professor Tony Horsewill of the School of Physics and Astronomy says: “For me a lot of the motivation for carrying out this investigation came from the sheer pleasure of studying such a unique and beautiful molecule and teasing out the fascinating insights it gave into the fundamentals of quantum molecular dynamics. Intellectually, it’s been hugely enjoyable.
“However, as with any blue-skies research initiative there is always the promise of new, often unforeseen, applications. Indeed, in the case of water molecules inside buckyballs we have a guest molecule that possesses an electric dipole moment and the collaboration is already investigating its use in molecular electronics, including as an innovative component of a molecular transistor.”
The research has recently been published in Proceedings of the National Academy of Sciences.
The discovery of the C60 Buckminsterfullerene, and the related class of molecules the fullerenes, in the mid-1980s earned Professors Harry Kroto, Robert Curl, and the late Richard Smalley the Nobel Prize in Chemistry in 1996.
It has a cage-like spherical structure made up from 20 hexagons and 12 pentagons and resembles a soccer ball, earning it the nickname “buckyball.”
Molecular surgery
In a recent breakthrough in synthetic chemistry, Japanese scientists from Kyoto have invented a molecular surgery technique allowing them to successfully permanently seal small molecules such as H2 and H2O inside C60.
They used a set of surgical synthetic procedures on the C60 “cage” that produced an opening large enough to “push” an H2 or H2O molecule inside at high temperature and pressure. The system was then cooled down to stabilize the entrapped molecule inside and the cage was surgically repaired to reproduce a C60.
Horsewill adds: “This technique succeeds in combining perhaps the universe’s most beautiful molecule C60 with its simplest.”
The Nottingham research group has employed a technique called inelastic neutron scattering (INS) where a beam of neutrons—fundamental particles that make up the atomic nucleus—is used to investigate the “cage rattling” motion of the guest molecules within the C60.
Their investigations have given an insight into the wavelike nature of H20 and H2 molecules and their orbital and rotational motion as they move within the C60.
New types of water
Professor Malcolm Levitt, of the School of Chemistry at the University of Southampton, who has used the technique nuclear magnetic resonance (NMR) to study the quantum properties of the caged molecules, says: “By confining small molecules such as water in fullerene cages we provide the controlled environment of a laboratory but on the scale of about one nanometer.
“Under these conditions, the confined molecules reveal a wave-like nature and behave according to the laws of quantum mechanics. Apart from their intrinsic interest, we expect that the special properties of these materials will lead to a variety of applications, such as new ways to brighten the images of MRI scans, and new types of computer memory.”
The paper also separately identifies two subtly different forms of H2O—ortho-water and para-water. These so called nuclear spin-isomers also owe their separate identities to quantum mechanical principles.
Researchers from Brown University, as well as scientists in Japan, France, Estonia, and the UK contributed to the findings.

Pesar moléculas individualmente.


‘Nanobridge’ weighs molecules one by one

This scanning electron micrograph shows one of the molecule-weighing devices. The bridge-like section at the center vibrates sideways. The scale bar at the bottom is two microns.Photo by: Credit:Scott Kelberg and Michael Roukes/Caltech
Researchers say the new technology will eventually help doctors diagnose diseases, enable biologists to study viruses, probe the molecular machinery of cells, and even allow scientists to better measure nanoparticles and air pollution.
Described in the journal Nature Nanotechnology, the device—which is only a couple millionths of a meter in size—consists of a tiny, vibrating bridge-like structure. When a particle or molecule lands on the bridge, its mass changes the oscillating frequency in a way that reveals how much the particle weighs.
“As each particle comes in, we can measure its mass,” says Michael Roukes, professor of physics, applied physics, and bioengineering at California Institute of Technology (Caltech). “Nobody’s ever done this before.”
The new instrument is based on a technique Roukes and his colleagues developed over the last 12 years. In work published in 2009, they showed that a bridge-like device—called a nanoelectromechanical system (NEMS) resonator—could indeed measure the masses of individual particles, which were sprayed onto the apparatus.
The difficulty, however, was that the measured shifts in frequencies depended not only on the particle’s actual mass, but also on where the particle landed. Without knowing the particle’s landing site, the researchers had to analyze measurements of about 500 identical particles in order to pinpoint its mass.
But with the new and improved technique, the scientists need only one particle to make a measurement. “The critical advance that we’ve made in this current work is that it now allows us to weigh molecules—one by one—as they come in,” Roukes says.
To do so, the researchers analyzed how a particle shifts the bridge’s vibrating frequency. All oscillatory motion is composed of so-called vibrational modes. If the bridge just shook in the first mode, it would sway side to side, with the center of the structure moving the most.
The second vibrational mode is at a higher frequency, in which half of the bridge moves sideways in one direction as the other half goes in the opposite direction, forming an oscillating S-shaped wave that spans the length of the bridge. There is a third mode, a fourth mode, and so on. Whenever the bridge oscillates, its motion can be described as a mixture of these vibrational modes.
The team found that by looking at how the first two modes change frequencies when a particle lands, they could determine the particle’s mass and position, explains Mehmet Selim Hanay, a postdoctoral researcher in Roukes’s lab and first author of the paper.
“With each measurement we can determine the mass of the particle, which wasn’t possible in mechanical structures before.”
Traditionally, molecules are weighed using a method called mass spectroscopy, in which tens of millions of molecules are ionized—so that they attain an electrical charge—and then interact with an electromagnetic field. By analyzing this interaction, scientists can deduce the mass of the molecules.
The problem with this method is that it does not work well for more massive particles—like proteins or viruses—which have a harder time gaining an electrical charge. As a result, their interactions with electromagnetic fields are too weak for the instrument to make sufficiently accurate measurements.
The new device, on the other hand, does work well for large particles. In fact, the researchers say, it can be integrated with existing commercial instruments to expand their capabilities, allowing them to measure a wider range of masses.
The researchers demonstrated how their new tool works by weighing a molecule called immunoglobulin M (IgM), an antibody produced by immune cells in the blood. By weighing each molecule—which can take on different structures with different masses in the body—the researchers were able to count and identify the various types of IgM.
Medical uses
Not only was this the first time a biological molecule was weighed using a nanomechanical device, but the demonstration also served as a direct step toward biomedical applications. Future instruments could be used to monitor a patient’s immune system or even diagnose immunological diseases. For example, a certain ratio of IgM molecules is a signature of a type of cancer called Waldenström macroglobulinemia.
In the more distant future, the new instrument could give biologists a view into the molecular machinery of a cell. Proteins drive nearly all of a cell’s functions, and their specific tasks depend on what sort of molecular structures attach to them—thereby adding more heft to the protein—during a process called posttranslational modification.
By weighing each protein in a cell at various times, biologists would now be able to get a detailed snapshot of what each protein is doing at that particular moment in time.
Another advantage of the new device is that it is made using standard, semiconductor fabrication techniques, making it easy to mass-produce. That’s crucial, since instruments that are efficient enough for doctors or biologists to use will need arrays of hundreds to tens of thousands of these bridges working in parallel.
“With the incorporation of the devices that are made by techniques for large-scale integration, we’re well on our way to creating such instruments,” Roukes says. This new technology, the researchers say, will enable the development of a new generation of mass-spectrometry instruments.
The team includes researchers from the Kavli Nanoscience Institute at Caltech and Commissariat à l’Energie Atomique et aux Energies Alternatives, Laboratoire d’électronique des technologies de l’information (CEA-LETI) in Grenoble, France.
Support was provided by the Kavli Nanoscience Institute, the National Institutes of Health, the National Science Foundation, the Fondation pour la Recherche et l’Enseignement Superieur from the Institut Merieux, the Partnership University Fund of the French Embassy to the USA, an NIH Director’s Pioneer Award, the Agence Nationale pour la Recherche through the Carnot funding scheme, a Chaire d’Excellence from Fondation Nanosciences, and European Union CEA Eurotalent Fellowships.
Source: Caltech

Energía solar más eficiente.


From icy water to steam via nanoparticles

New technology that uses nanoparticles to convert solar energy directly into steam is about "a lot more than electricity," says Naomi Halas of the Laboratory for Nanophotonics at Rice University. "With this technology, we are beginning to think about solar thermal power in a completely different way." (Credit:
The solar steam method has an overall energy efficiency of 24 percent. Photovoltaic solar panels, by comparison, typically have an overall energy efficiency around 15 percent. Inventors of solar steam expect the first uses of the new technology won’t be for electricity generation but rather for sanitation and water purification in developing countries.
“This is about a lot more than electricity,” says Naomi Halas of the Laboratory for Nanophotonics at Rice University. “With this technology, we are beginning to think about solar thermal power in a completely different way.”

Straight from the Source

DOI: 10.1021/nn304948h
As reported in ACS Nano, the efficiency of solar steam is due to the light-capturing nanoparticles that convert sunlight into heat. When submerged in water and exposed to sunlight, the particles heat up so quickly they instantly vaporize water and create steam. Halas says the solar steam’s overall energy efficiency can probably be increased as the technology is refined.
“We’re going from heating water on the macro scale to heating it at the nanoscale,” Halas says. “Our particles are very small—even smaller than a wavelength of light—which means they have an extremely small surface area to dissipate heat. This intense heating allows us to generate steam locally, right at the surface of the particle, and the idea of generating steam locally is really counterintuitive.”
To show just how counterintuitive, Rice graduate student Oara Neumann videotaped a solar steam demonstration in which a test tube of water containing light-activated nanoparticles was submerged into a bath of ice water. Using a lens to concentrate sunlight onto the near-freezing mixture in the tube, Neumann showed she could create steam from nearly frozen water.
Steam is one of the world’s most-used industrial fluids. About 90 percent of electricity is produced from steam, and steam is also used to sterilize medical waste and surgical instruments, to prepare food, and to purify water.
Most industrial steam is produced in large boilers—solar steam’s efficiency could allow it to become economical on a much smaller scale.
People in developing countries will be among the first to see the benefits of solar steam. Rice engineering undergraduates have already created a solar steam-powered autoclave that’s capable of sterilizing medical and dental instruments at clinics that lack electricity. Halas also won a Grand Challenges grant from the Bill and Melinda Gates Foundation to create an ultra-small-scale system for treating human waste in areas without sewer systems or electricity.
“Solar steam is remarkable because of its efficiency,” says Neumann, the lead co-author on the paper. “It does not require acres of mirrors or solar panels. In fact, the footprint can be very small. For example, the light window in our demonstration autoclave was just a few square centimeters.”
Another potential use could be in powering hybrid air-conditioning and heating systems that run off of sunlight during the day and electricity at night. Halas, Neumann, and colleagues have also conducted distillation experiments and found that solar steam is about two-and-a-half times more efficient than existing distillation columns.
Halas, a professor in electrical and computer engineering and of physics, chemistry, and biomedical engineering, specializes in creating and studying light-activated particles. One of her creations, gold nanoshells, is the subject of several clinical trials for cancer treatment.
For the cancer treatment technology and many other applications, Halas’ team chooses particles that interact with just a few wavelengths of light. For the solar steam project, Halas and Neumann set out to design a particle that would interact with the widest possible spectrum of sunlight energy. Their new nanoparticles are activated by both visible sunlight and shorter wavelengths that humans cannot see.
“We’re not changing any of the laws of thermodynamics,” Halas says. “We’re just boiling water in a radically different way.”
The research was supported by the Welch Foundation and the Bill and Melinda Gates Foundation.
Source: Rice University

Utilizar la energía de los cambios de temperatura.


Scientists use nanotechnology to harvest electricity from temperature fluctuations



So far your footstepsbreath and nervous energy have all been tapped to charge up batteries, and now researchers from the Georgia Institute of Technology scientists have pulled it off using thermal changes. They did it with so-called pyroelectric nanogenerators, which use polarization changes to harvest heat energy from temperature fluctuations. Normally output current is too low for commercial electronics, but by making one with lead zirconate titanate (PZT), the team was able to create a device that could charge a Li-ion coin battery to power a green LED for a few seconds. The researchers predict that by doubling the surface area, they could drive wireless sensors or LCDs using only environmental temperature changes from an engine or water pipe, for instance. The result could be green power, but without all that pesky moving around.

Teletransportación cuántica entre dos objetos macroscópicos.


Researchers Achieve Quantum Teleportation Between Two Macroscopic Objects For The First Time


Quantum Teleportation Explained In case you want to try this at home.
Sometimes it’s tough to get excited about stuff happening in quantum technologies, not because it’s anything less than fascinating but because it can be so hard to wrap your head around this stuff and anyhow the practical applications often seem very far away. But this is one of those milestones that you have to appreciate: Physicists have for the first time teleported quantum information from one macroscopic object to another.
Researchers have been able to teleport quantum information for a while now. Quick quantum primer: This isn’t Star Trek-style teleportation, but the transfer of information--of quantum states--from one place to another without that information crossing the space between them in any way. This is achieved through the strange quantum phenomenon of entanglement, which allows two quantum objects to share the same quantum state such that if you influence one particle you also influence the other, whether they are separated by nanometers or light-years.
So by entangling two photons, for instance, physicists have demonstrated the ability to transmit quantum information from one place to another by encoding it in these quantum states--influence one of the pair and a change can be measured in the other without any information actually passing between the two. Researchers have done this before, between photons, between ions, and even between a macroscopic object and a microscopic object. But now Chinese researchers have, for the first time, achieved quantum teleportation between two macroscopic objects across nearly 500 feet using entangled photons.
That’s pretty huge. The two bundles of rubidium atoms that served as sender and receiver are more or less analogs for what we hope will someday be our “quantum Internet”--a system of routers like the ones we have now that, instead of beaming information around a vast network of fiber optic wires, will send and receive information through entangled photons. So in a way, this is like a first proof of concept, evidence that the idea works at least in the lab.
Now all we have to do is figure out is how to build several of these in series so they can actually pass information from one to the other. To do that, we only have to somehow force these quantum states to exist for longer than the hundred microseconds or so that they last now before degrading. Sounds easy enough.

Breakthrough Nanoparticle Halts Multiple Sclerosis




Northwestern Medicine researchers developed a biodegradable nanoparticle (shown here) that regulates the immune system in mice with multiple sclerosis.
In a breakthrough for nanotechnology and multiple sclerosis, a biodegradable nanoparticle turns out to be the perfect vehicle to stealthily deliver an antigen that tricks the immune system into stopping its attack on myelin and halt a model of relapsing remitting multiple sclerosis (MS) in mice, according to new Northwestern Medicine research.
The new nanotechnology also can be applied to a variety of immune-mediated diseases including, Type 1 diabetes, food allergies, and airway allergies such as asthma. 
In MS, the immune system attacks the myelin membrane that insulates nerves cells in the brain, spinal cord, and optic nerve. When the insulation is destroyed, electrical signals can’t be effectively conducted, resulting in symptoms that range from mild limb numbness to paralysis or blindness. About 80 percent of MS patients are diagnosed with the relapsing remitting form of the disease.

Noticia completa: http://www.feinberg.northwestern.edu/news/2012/11/nanoparticle.html

Nanocrystals Detect Internal Damages of Composite Materials




Picture of zinc oxide tetrapods taken by scanning electron microscope (Copyright 2012, Wiley)


"The luminescent features of zinc oxide tetrapod crystals are well established. According to our work hypothesis, these characteristics showed pronounced variations under a mechanical load, and we realised that it could help to detect internal damages of composite materials", says Dr. Yogendra Mishra of Kiel University's Technical Faculty. In one experiment, the scientists added zinc oxide tetrapod shaped crystals to a silicone (polydimethylsiloxane) polymer and tested its general properties. They found that the resulting composite material is on the one hand stronger than silicon and on the other hand emits light in different colors when exposed to UV light. When the material is subjected to mechanical stress, the intensities of the emitted lights changes.


Fuente: http://www.azonano.com/news.aspx?newsID=26077

Researchers Use Gold Nanoparticles for Low-Cost Semiconductors Production


A completely new method of manufacturing the smallest structures in electronics could make their manufacture thousands of times quicker, allowing for cheaper semiconductors. The findings have been published in the latest issue of Nature.


A completely new method of manufacturing the smallest structures in electronics could make their manufacture thousands of times quicker, allowing for cheaper semiconductors. (Credit: Lund University, Sweden)

Instead of starting from a silicon wafer or other substrate, as is usual today, researchers have made it possible for the structures to grow from freely suspended nanoparticles of gold in a flowing gas.
Behind the discovery is Lars Samuelson, Professor of Semiconductor Physics at Lund University, Sweden, and head of the University's Nanometre Structure Consortium. He believes the technology will be ready for commercialisation in two to four years' time. A prototype for solar cells is expected to be completed in two years.
"When I first suggested the idea of getting rid of the substrate, people around me said 'you're out of your mind, Lars; that would never work'. When we tested the principle in one of our converted ovens at 400°C, the results were better than we could have dreamt of", he says.
"The basic idea was to let nanoparticles of gold serve as a substrate from which the semiconductors grow. This means that the accepted concepts really were turned upside down!"
Since then, the technology has been refined, patents have been obtained and further studies have been conducted. In the article in Nature, the researchers show how the growth can be controlled using temperature, time and the size of the gold nanoparticles.
Recently, they have also built a prototype machine with a specially built oven. Using a series of ovens, the researchers expect to be able to 'bake' the nanowires, as the structures are called, and thereby develop multiple variants, such as p-n diodes.
A further advantage of the technology is avoiding the cost of expensive semiconductor wafers.
"In addition, the process is not only extremely quick, it is also continuous. Traditional manufacture of substrates is batch-based and is therefore much more time-consuming", adds Lars Samuelson.
At the moment, the researchers are working to develop a good method to capture the nanowires and make them self-assemble in an ordered manner on a specific surface. This could be glass, steel or another material suited to the purpose.
The reason why no one has tested this method before, in the view of Professor Samuelson, is that today's method is so basic and obvious. Such things tend to be difficult to question.
However, the Lund researchers have a head start thanks to their parallel research based on an innovative method in the manufacture of nanowires on semiconductor wafers, known as epitaxy – consequently, the researchers have chosen to call the new method aerotaxy. Instead of sculpting structures out of silicon or another semiconductor material, the structures are instead allowed to develop, atomic layer by atomic layer, through controlled self-organisation.
The structures are referred to as nanowires or nanorods. The breakthrough for these semiconductor structures came in 2002 and research on them is primarily carried out at Lund, Berkeley and Harvard universities. The Lund researchers specialise in developing the physical and electrical properties of the wires, which helps create better and more energy-saving solar cells, LEDs, batteries and other electrical equipment that is now an integrated part of our lives.
Source: http://www.lu.se

Tosquedad en capas superficiales de celdas solares nanoestructuradas

superficie de la célula solar Policristalino-Si.
 Rango los 90ìm los x 90ìm de la Exploración con un AFM
Una tecnología de buen aprovechamiento y que reduce costes son las finas películas de silicio policristalino. Se necesitan propiedades eléctricas y cristalinas muy buenas de las capas para alcanzar eficiencias de conversión de energía altamente competitivas. Y aun que en esta tecnología su bajo costo juega un papel fundamental, los substratos son generalmente muy ásperos y por tanto no transparentes lo que presenta una desventaja para la celda solar. Dicha tosquedad del substrato tiene un efecto grande sobre todos los aspectos de el proceso del PC-Si; se necesitan sustratos más lisos que proporcionen una mayor capa amortiguadora y un aumento en el voltaje así como en la eficiencia de la celda solar. Dicha eficiencia se obtendría si la celda solar de silicio amorfas hidrogenadas pudieran ser mejoradas para aumentar la absorción luminosa en las capas delegadas introduciéndole un dispersor de luz en la superficie áspera.

jueves, 29 de noviembre de 2012


DOMINGO, SEPTIEMBRE 30, 2012

A continuacion presentare una noticia, la cual como su titulo lo dice explica como un grupo de investigadores lograron comprender las propiedades fotosinteticas. El uso de proteinas favorecerá el camino hacia los generadores de corriente.

Célula solar que consiste en una sola molécula

"Un equipo de científicos de la Universidad Técnica de Munich y Universidad de Tel Aviv desarrollaron un método para medir las fotocorrientes de un único sistema funcionalizado de proteínas fotosintéticas. Los científicos pudieron demostrar que dicho sistema se puede integrar y dirigir de forma selectiva en arquitecturas de dispositivos fotovoltaicos artificiales mientras conserva sus propiedades funcionales biomoleculares. Las proteínas actúan como bombas de electrones de una sola molécula inducidas por la luz y altamente eficientes, capaces de actuar como generadores de corriente en los circuitos eléctricos a escala nanométrica.

El equipo interdisciplinario publicó los resultados en la revista Nature Nanotechnology, bajo el título "Photocurrent of a single photosynthetic protein" (fotocorriente de una proteína fotosintética individual).

Los científicos investigaron el centro de reacción del fotosistema-I que es un complejo de proteína de clorofila localizado en las membranas de los cloroplastos de las cianobacterias. Las plantas, las algas y las bacterias utilizan la fotosíntesis para convertir la energía solar en energía química. Las etapas iniciales de este proceso -en las que se absorbe la luz y se transfieren la energía y los electrones- están mediadas por proteínas fotosintéticas compuestas de complejos de carotenoides y clorofila. Hasta ahora, ninguno de los métodos disponibles eran lo suficientemente sensibles como para medir las fotocorrientes generadas por una sola proteína El fotosistema-I exhibe excelentes propiedades optoelectrónicas que sólo se encuentran en los sistemas fotosintéticos. La dimensión de la nanoescala, además, hace del fotosistema-I una unidad prometedora para las aplicaciones en la optoelectrónica molecular."

Al hablar de celdas solares o el cambio de energia solar hacia energia química hablamos de procesos demasiado complejos, ultimamente los descubrimientos en generadores químicos a sido de alta importancia, como pudimos ver en la noticia; es necesario entender que no solo aportaran informacion y apoyo a los paneles solares tambien ayudaran en la industria de la optica.

Agenda Ciudadana de Ciencia, Tecnología e Innovación. VOTEN!



 

miércoles, 28 de noviembre de 2012

Generar Vapor con el Sol activado por Nanoparticulas

La conversión de luz a calor por nanoparticulas conductivas, bajo iluminación laser, a demostrado que induce dramáticamente localizado el calentamiento e incluso evaporación de su medio anfitrión (liquido en que están depositadas). En este proceso podemos usar la energía solar como base para la evaporación de un gas, sin la necesidad de tener que calentar previamente el liquido al punto de ebullición pues las partículas submicrometricas absorben la luz en el espectro de la luz solar y se dispersan y calientan el agua por en sima de los 100°C en geometrías compactas. En este caso las partículas metálicas conocidas como plasmones superficiales son las responsables absorbedoras intensas de radiación óptica, debido a las oscilaciones colectivas de su electrón de conducción deslocalizado. Estas partículas cuando se excitan por  resonancia, la energía no vuelve a irradiar a través de la dispersión de luz si no que se disipa a través de una amortiguación Landau (no radiactiva) que resulta en el incremento dramático de la temperatura en la proximidad de la nanopartiícula. Es de gran interés en aplicaciones de medicina como en la  terapia de cáncer fototermica.
 
La tecnología ahi la encontramos, ahora solo hay q aprovecharla y darle un uso

PINTURA NANOTECNOLÓGICA QUE ELIMINA BACTERIAS Y MALOS OLORES


Esta sofisticada pintura de paredes fue desarrollada por un grupo de investigadores en España. Se trata de una pintura convencional a la que le agregaron catalizadores de luz estructurados nanométricamente. Estos tienen la capacidad de eliminar bacterias que causan suciedad y malos olores con el simple contacto de la luz sobre ellas.
Por ello, el elemento primario para que esta pintura funcione es su interacción con la luz (sea ésta solar o artificial). Ya que es por esta interacción, que los catalizadores nanoestructurados se activan.

Esta reacción química es la que se conoce como fotocatálisis. Se describe como un proceso por medio del cual las sustancias "nocivas" del aire son transformadas en CO2 y vapor de agua.
Entre las muchas sustancias que esta pintura es capaz de destruir se encuentran los alérgenos de animales y plantas, las partículas del tabaco, el polvo, las esporas de los hongos, los disolventes, conservantes de madera o insecticidas.
 
Si hay algúh interesado, esta pintura se encuentra a la venta en todas las ciudades y provincias de España. Su precio se aproxima a los 50 euros por cinco litros. ¡Llévele, llévele!




Referencia:
http://es.cetadepinturaindustrial.com/noticia.php?enlace=pintura-nanotecnologia


POR SI NO QUEDÓ CLARO LO QUE LA ESCALA "NANO" SIGNIFICA
 
 
 
A continuación se muestra un corto animado producido por Sciencie Alberta Foundations, sitio web educativo con múltiples premios por su éxito como innovación educativa. Enjoy:
 
 
 
Enlace a Sciencia Alberta Foundations: http://sciencealberta.org/

Nanoaceite Termo-regulador

Científicos de la Universidad de Rice han creado un nano-aceite que podría aumentar mucho la capacidad de disipar el exceso de calor en dispositivos de tamaños desde los grandes transformadores eléctricos hasta lospequeños componentes microelectrónicos. La investigación realizada en el laboratorio científico de materiales de la Universidadde Rice y que aparece en la revista ACS Nano de la American Chemical Society, podría aumentarla eficacia de este tipo de aceites de transformadores hasta en un 80 por ciento de una manera que es a la vez rentable y amable con el medioambiente. El trabajo se enfocó en los transformadores para sistemas de energía. Los transformadores se llenan con aceites minerales que enfrían y aíslan los embobinados en el interior, los cuales deben permanecer separados unos de otros par aevitar fugas en el voltaje o cortocircuitos.

Los investigadores descubrieronque una cantidad muypequeña de partículas de nitruro de boro hexagonal (h-BN) de dos dimensiones (similares algrafeno) suspendidas en aceitesde transformadores estándares son muy eficientes para eliminar el calor de un sistema.Se ha encontrado que con tan solo el 0,1 por ciento en peso de h-BN en aceite de transformador se mejora en casi un 80 por ciento su eficacia. “Con un0,01 por ciento en peso, el aumento fue de alrededor de 9 por ciento” e, incluso, con una cantidad muy baja de material, se pueden mejorar los fluidos sin comprometer las propiedadesaislantes eléctricas.

Adiós petróleo





Los vertidos de petróleo en el mar suponen un problema ambiental muy importante. Un equipo de investigadores del Instituto Tecnológico de Massachusetts ha desarrollado un método paraseparar el agua del aceite empleando imanes. Esta técnica permitiría que el petróleo fuera después reutilizado, de forma que se compensarían los costes de la limpieza.

El método propuesto consiste en añadir a la mezclananopartículas con hierro para después separar el aceite usando un imán. Los investigadores indican que se trata de una maniobra muy sencilla pero que deberá, sin embargo, realizarse en un buque para que las nanopartículas no contaminen el océano. En otros trabajos se han propuesto métodos similares pero que tenían el inconveniente de que era necesario conocer de antemano la concentración de agua y aceite en la mezcla. La técnica propuesta, al colocar los imanes dentro de la corriente, y no fuera de ella, como en los métodos anteriores, se puede aplicar siempre con buenos resultados, sin importar la concentración de cada componente en la mezcla.

"Aún no se ha tratado lo suficiente el problema de los vertidos de petróleo", opina Ronald Rosensweig, un ex investigador de la empresa Exxon y un pionero en el estudio de ferrofluidos. "Se podría pensar en separar el aceite del agua por centrifugación, pero muchas veces la densidad de ambos fluidos es la misma y esto no es posible. El gancho magnético permitiría hacer una separación más rápida y efectiva".

-Victoria Gonzáles, Revista "Muy interesante"

Nanopiramides






Investigadores de la Universidad de Twente (Holanda) han desarrollado una curiosa tecnología que permite atrapar células vivas dentro de diminutas pirámides microscópicas para poder estudiarlas en el laboratorio. Como muestra la imagen, estas minúsculas pirámides, creadas con técnicas de fabricación tridimensional en la nanoescala -es decir, a un tamaño equivalente a la diezmilésima parte de un cabello humano-, tienen las paredes abiertas para permitir que las células interactúen unas con otras, según explican los investigadores en la revista especializada Small.

Los nanocientíficos pusieron a prueba el método con condrocitos, que son las células que forman el cartílago. En el futuro esperan aprovechar el hueco entre pirámides contiguas para crear canales de nanofluidos que permitan mantener nutridas a las células durante los experimentos. Además, están convencidos de que el método ayudará a los biólogos y a los expertos en medicina regenerativa a entender mejor cómo funciona la regeneración de tejidos.


-Elena Sanz, Revista "Muy Interesante"

SmartPhones sin preocupaciones

La nanotecnología, como saben, tiene muchas aplicaciones relacionado a muchas industrias diferentes. Ésta es una de sus aplicaciones:



En el sur de California, una compañía creó lo que llaman "Liquipel", es uno de los inventos más revolucionarios para smartphones. 

Es un protector químico fabricado a base de nanopartículas que aísla los circuitos y otros componentes de los telefonos móviles de cualquier líquido que pueda caer sobre el dispositivo. Gracias a este invento, uno de los accidentes más frecuentes con estos gadgets ha dejado de ser una preocupación para los usuarios.

No es la carcaza ni un protector físico, se trata de un tratamiento aplicado a los componentes del teléfono, el costo de éste tratamiento está cotizado aproximadamente desde los 47 hasta los 60 euros dependiendo del tipo de transporte por el que se envíe el dispositivo a las oficinas de dicha compañía y de regreso al usuario.

-Revista "Muy Interesante"

Nanorobots contra científicos

Desde diciembre pasado han estado circulando noticias de los descubrimientos del MIT, a finales de enero aparecieron reportajes en los medios de comunicación, pero la revelación del primero de marzo en TechReview.com (la edición electrónica de la revista Technology Review), causó un tremendo impacto en muchas personas, aún entre quienes están involucrados íntimamente en la nanotecnología: la posibilidad de construir robots capaces de utilizar átomos individuales como materiales de construcción. En una reunión patrocinada por el Grupo ETC y la Fundación Dag Hammarskhöld en junio pasado, el Presidente y Director Ejecutivo de Nanophase(5) predijo que el autoensamblaje molecular (que incluye nanorobots capaces de autoconstruirse) no ocurriría nunca. En un ácido intercambio que se dio en Scientific American en septiembre pasado entre K. Eric Drexler (cabeza del Foresight Institute, un monstruo de la nano-investigación) y el premio Nobel Richard E. Smalley, éste último también vaticinó que “los robots de escala nanométrica” no serían desarrollados “nunca”(6). Smalley es fundador del Programa de Nanotecnología en la Universidad Rice, y por otro lado, también es fundador de su recientemente abierta empresa, Carbon Nanotechnologies Inc. Pero como se está viendo, los desarrollos más recientes en la Universidad de California en Berkeley podrían revirar muy pronto ese “nunca” que vaticinó Smalley.



-Nanotecnologica.com

Apple i Phone 4 NANOTECNOLOGIA





Para aquellos amantes de Apple, aquí un secreto de una de sus funciones:



Esto es un giroscpio, los iPhone 4, lo contienen y es para que el dispositivo "sepa" en que parte del espacio tridimensional se encuentra, el giscopio que contiene el iPhone puede oscilar en 3 grados hacia cualquier lado.
La verdadera tecnologia se encuentra en el fondo de este microprocesador.


Aqui empieza la verdadera nanotecnolgía.


Para llegar a esta imagen se utiliza un Microscopio de Electrones.


Para llegar hasta aqui se tiene que pasar por una capa muy dura, pero es por seguridad, ya que un solo cabello humano, arruinaría el funcionamiento del giroscopio.





Regeneración de tejidos






El trabajo de investigación desarrollado por Samuel I. Stupp, profesor de ciencia de los materiales, química, y medicina, y director del Instituto para la BioNanotecnología en la Medicina (IBNAM), indica que las nanotecnologías pueden usarse a fin de movilizar las propias capacidades curativas del cuerpo para reparar o regenerar tejidos y órganos.

En una rotunda demostración de lo que la nanotecnología podría lograr en la medicina regenerativa, ratones de laboratorio paralizados por lesiones en la médula espinal han recobrado la capacidad de emplear sus patas posteriores seis semanas después de una inyección de un nanomaterial diseñado para este propósito.

Inyectando moléculas que se diseñaron para que se autoensamblaran en las nanoestructuras del tejido de la médula espinal, los investigadores han logrado repoblar de neuronas la sección dañada. Las nanofibras, miles de veces más finas que un cabello humano, son la clave no sólo para impedir la formación del dañino tejido de cicatriz que impide que se cure la médula espinal, sino para estimular al cuerpo a regenerar las células perdidas o dañadas.

Stupp y sus colaboradores diseñaron moléculas con la capacidad de autoensamblarse en nanofibras después de ser introducidas en el cuerpo por medio de una inyección. Cuando las nanofibras se forman pueden ser inmovilizadas en el área de tejido donde es necesario que se active algún proceso biológico, por ejemplo el de salvar células dañadas o la repoblación con las células diferenciadas necesarias a partir de células madre.

Este mismo trabajo también tiene implicaciones para enfermedades como el Parkinson y el Alzheimer. En ambas, importantes células del cerebro dejan de funcionar adecuadamente.

Stupp también ha presentado algunos resultados de la investigación que tiene en marcha con colaboradores en México y Canadá: ratones que se recuperan de los síntomas de la enfermedad de Parkinson después de ser expuestos a las nanoestructuras bioactivas desarrolladas por Stupp en los laboratorios de la Universidad del Noroeste. Otro trabajo, desarrollado por Stupp y Jon Lomasney, profesor de patología en la citada universidad, está demostrando el uso de nanoestructuras y proteínas para lograr la recuperación de las funciones del corazón después de un infarto. 

-Solociencia.com