Wednesday, December 31, 2014

A repulsive material: New hydrogel dominated by electrostatic repulsion -- ScienceDaily

According to Yasuhiro Ishida, head of the Emergent Bioinspired Soft Matter Research Team, the work began from a surreptitious discovery, that when titanate nano-sheets are suspended in an aqueous colloidal dispersion, they align themselves face-to-face in a plane when subjected to a strong magnetic field. The field maximizes the electrostatic repulsion between them and entices them into a quasi-crystalline structure. They naturally orient themselves face to face, separated by the electrostatic forces between them.
To create the new material, the researchers used the newly discovered method to arrange layers of the sheets in a plane, and once the sheets were aligned in the plane, fixed the magnetically induced structural order by transforming the dispersion into a hydrogel using a procedure called light-triggered in-situ vinyl polymerization. Essentially, pulses of light are used to congeal the aqueous solution into a hydrogel, so that the sheets could no longer move.
By doing this, they created a material whose properties are dominated by electrostatic repulsion, the same force that makes our hair stand end when we touch a van generator.

Thursday, December 11, 2014

Green meets Nano: Scientists create multifunctional nanotubes using nontoxic materials









A doctoral student in materials science at Technische Universität Darmstadt is making multifunctional nanotubes of gold -- with the help of vitamin C and other harmless substances.










Coffee, apple juice, and vitamin C: things that people ingest every day are experimental material for chemist Eva-Maria Felix. The doctoral student in the research group of Professor Wolfgang Ensinger in the Department of Material Analysis is working on making nanotubes of gold. She precipitates the precious metal from an aqueous solution onto a pretreated film with many tiny channels. The metal on the walls of the channels adopts the shape of nanotubes; the film is then dissolved. The technique itself is not new, but Felix has modified it: "The chemicals that are usually used for this were just too toxic for me." She preferred not to use cyanide, formaldehyde, arsenic and heavy metal salts. She was inspired by a journal article by researchers who achieved silver precipitation using coffee.


Felix also used coffee in her first experiments. She then tested apple juice, followed by vitamin C. This seemed to be the best suited to her because "you never know what's in coffee and apple juice." On the other hand, Vitamin C -- or ascorbic acid -- is available in pure form from chemical stores -- a requirement for reproducible studies. But what does the vitamin have to do with the precipitation of gold? In the human body, vitamin C makes free radicals harmless by transferring electrons to them. "Gold precipitation functions according to the same principle. The only difference is that the vitamin does not take on radicals, but rather gold ions," explains Falk Münch, a postdoctoral researcher and supervisor of Felix' PhD thesis. The gold ions that are dissolved in the precipitation bath are transformed into metallic gold after absorbing electrons.




Wednesday, December 10, 2014

Green meets Nano: Scientists create multifunctional nanotubes using nontoxic materials









A doctoral student in materials science at Technische Universität Darmstadt is making multifunctional nanotubes of gold -- with the help of vitamin C and other harmless substances.










Coffee, apple juice, and vitamin C: things that people ingest every day are experimental material for chemist Eva-Maria Felix. The doctoral student in the research group of Professor Wolfgang Ensinger in the Department of Material Analysis is working on making nanotubes of gold. She precipitates the precious metal from an aqueous solution onto a pretreated film with many tiny channels. The metal on the walls of the channels adopts the shape of nanotubes; the film is then dissolved. The technique itself is not new, but Felix has modified it: "The chemicals that are usually used for this were just too toxic for me." She preferred not to use cyanide, formaldehyde, arsenic and heavy metal salts. She was inspired by a journal article by researchers who achieved silver precipitation using coffee.


Felix also used coffee in her first experiments. She then tested apple juice, followed by vitamin C. This seemed to be the best suited to her because "you never know what's in coffee and apple juice." On the other hand, Vitamin C -- or ascorbic acid -- is available in pure form from chemical stores -- a requirement for reproducible studies. But what does the vitamin have to do with the precipitation of gold? In the human body, vitamin C makes free radicals harmless by transferring electrons to them. "Gold precipitation functions according to the same principle. The only difference is that the vitamin does not take on radicals, but rather gold ions," explains Falk Münch, a postdoctoral researcher and supervisor of Felix' PhD thesis. The gold ions that are dissolved in the precipitation bath are transformed into metallic gold after absorbing electrons.




Tuesday, December 9, 2014

Nanotubes may restore sight to blind retinas

Retinal degeneration is one of the most worrisome dangers in the aging process. Now researchers have made an important technological breakthrough towards a prosthetic retina that could help alleviate conditions that result from problems with this vital part of the eye.

New progress towards a prosthetic retina could help alleviate conditions that result from problems with this vital part of the eye. An encouraging new study published in Nano Letters describes a revolutionary novel device, tested on animal-derived retinal models, that has the potential to treat a number of eye diseases. The proof-of-concept artificial retina was developed by an international team led by Prof. Yael Hanein of Tel Aviv University's School of Electrical Engineering and head of TAU's Center for Nanoscience and Nanotechnology and including researchers from TAU, the Hebrew University of Jerusalem, and Newcastle University.
"Compared to the technologies tested in the past, this new device is more efficient, more flexible, and can stimulate neurons more effectively," said Prof. Hanein. "The new prosthetic is compact, unlike previous designs that used wires or metals while attempting to sense light. Additionally, the new material is capable of higher spatial resolution, whereas older designs struggled in this area."
A natural shape
The researchers combined semiconductor nanorods and carbon nanotubes to create a wireless, light-sensitive, flexible film that could potentially replace a damaged retina. The researchers tested the new device with chick retinas which were not yet light sensitive to prove that the artificial retina is able to induce neuronal activity in response to light.
Patients with age-related macular degeneration (AMD), which usually affects people age 60 or older who have damage to a specific part of the retina, will stand to benefit from the nanotube device if it is proved compatible in animals over the long term.
According to TAU doctoral student and research team member Dr. Lilach Bareket, there are already medical devices that attempt to treat visual impairment by sending sensory signals to the brain. While scientists are trying different approaches to develop an implant that can "see" light and send visual signals to a person's brain, to counter the effects of AMD and related vision disorders, many of these approaches require the use of metallic parts and cumbersome wiring or result in low resolution images. The researchers set out to make a more compact device.

Monday, December 8, 2014

Buckyballs enhance carbon capture





Amines bound by buckyballs can absorb carbon dioxide from emissions at industrial plants and at natural gas wells, according to new research. Tests from one to 50 atmospheric pressures showed the newly developed compound captured a fifth of its weight in carbon dioxide but no measurable amount of methane.
The Rice lab of chemist Andrew Barron revealed in a proof-of-concept study that amine-rich compounds are highly effective at capturing the greenhouse gas when combined with carbon-60 molecules.
The research is the subject of an open-access paper today in Nature's online journal Scientific Reports.
"We had two goals," Barron said. "One was to make the compound 100 percent selective between carbon dioxide and methane at any pressure and temperature. The other was to reduce the high temperature needed by other amine solutions to get the carbon dioxide back out again. We've been successful on both counts."
Tests from one to 50 atmospheric pressures showed the Rice compound captured a fifth of its weight in carbon dioxide but no measurable amount of methane, Barron said, and the material did not degrade over many absorption/desorption cycles.
Carbon-60, the soccer ball-shaped molecule also known as buckminsterfullerene (or the "buckyball") was discovered at Rice by Nobel Prize laureates Richard Smalley, Robert Curl and Harold Kroto in 1985. The ultimate curvature of buckyballs may make them the best possible way to bind amine molecules that capture carbon dioxide but allow desirable methane to pass through.

Friday, December 5, 2014

Atmospheric carbon dioxide used for energy storage products

Researchers have discovered a fascinating new way to take some of the atmospheric carbon dioxide that's causing the greenhouse effect and use it to make an advanced, high-value material for use in energy storage products.

Wednesday, December 3, 2014

Breakthrough in flexible electronics enabled by inorganic-based laser lift-off


A research team led by Prof. Keon Jae Lee of KAIST provides an easier methodology  to  realize  high  performance flexible electronics by using the  Inorganic-based Laser  Lift-off  (ILLO),  which  enables    nanoscale processes  for   high   density   flexible   devices and    high temperature processes that were previously difficult to achieve on plastic substrates.


Tuesday, December 2, 2014

Engineers make sound loud enough to bend light on a computer chip: Device could improve wireless communications systems





University of Minnesota engineering researchers have developed a chip on which both sound wave and light wave are generated and confined together so that the sound can very efficiently control the light. The novel device platform could improve wireless communications systems using optical fibers and ultimately be used for computation using quantum physics.
The research was recently published in Nature Communications
The University of Minnesota chip is made with a silicon base coated with a layer of aluminum nitride that conducts an electric change. Applying alternating electrical signal to the material causes the material to deform periodically and generate sound waves that grow on its surface, similar to earthquake waves that grow from the center of the earthquake. The technology has been widely used in cell phones and other wireless devices as microwave filters.
"Our breakthrough is to integrate optical circuits in the same layer of material with acoustic devices in order to attain extreme strong interaction between light and sound waves," said Mo Li, assistant professor in the Department of Electrical and Computer Engineering and the lead researcher of the study.
The researchers used the state-of-the-art nanofabrication technology to make arrays of electrodes with a width of only 100 nanometers (0.00001 centimeters) to excite sound waves at an unprecedented high frequency that is higher than 10 GHz, the frequency used for satellite communications.

New method to determine surface properties at the nanoscale





Engineering researchers at Texas Tech University have developed a method for characterizing the surface properties of materials at different temperatures at the nanoscale.
Knowing properties of materials at different temperatures is important in engineering, said Gregory McKenna, a professor of chemical engineering and the John R. Bradford Endowed Chair in Engineering. For example, the rubber O-ring that failed during the 1986 space shuttle disaster serves at a tragic case study of what can go wrong when decision-makers don't take this into account.
The problem, he said, is known properties of a material can radically change at the nanoscale -- a tiny scale about 1/1000 of the diameter of a human hair at which scientists have begun building machines that do work. McKenna and graduate student Meiyu Zhai looked at several polymers and explosive materials to see how surface properties varied at the nanoscale and how the surface impacts the nanoscale properties.
Their first results on the "multi-curve method" appeared in the peer-reviewed journal, Journal of Polymer Science Part B: Polymer Physics and was highlighted in Advances in Engineering.
"The nanoscale is a funny range of sizes where materials have properties that are not what we expect, even at a step up at the microscale," he said. "We are developing methods to characterize surface properties and relate them to nanoscale behavior using a nanoindenter and other nano-mechanical measurement methods."
In nanoindentation, researchers can investigate both the elastic properties (how materials spring back when pushed) or the viscous properties (how the material flows). The group has found several surprising results: For example, in other work, the team found extremely thin polycarbonate films become liquid-like at the nanoscale, while they are glassy at the macroscopic size scale. Nanoindentation can be used to relate surface properties to this observation.
As machines get smaller and smaller, McKenna said, knowing this information can be invaluable to future engineers.


New method to determine surface properties at the nanoscale

Monday, December 1, 2014

Nanomolar chemistry enables 1500 experiments in a single day

Chemists at pharma giant Merck have conducted over 1500 chemistry experiments in under a day thanks to a miniaturised, high throughput automation platform they developed for identifying how synthetic molecules react under various conditions. The work could speed up drug discovery and provide chemists with a tool kit to explore new medicinal compounds.

The discovery of drug leads involves synthesising complex molecules and then screening them to identify how they react under various conditions including temperature and concentration. However, a typical screen might require 10mg of a compound to get just one data point, while state-of-the-art methods achieve the same with 1mg of material. Not only is this time consuming, but every milligram is precious in medicinal chemistry and the substrates needed to synthesise complex molecules are invariably in short supply.
Frustrated by these problems, which mean many molecules designed at Merck never get made or tested, Tim Cernak, Spencer Dreher and colleagues at Merck Research Laboratories in Rahway in the US, have found a solution. They combined the robotics used in biotechnology with high throughput mass spectrometry techniques to produce between 50 and 500 times more reaction data than existing methods. The team demonstrated their nanomole-scale method could execute 1536 chemistry experiments in less than a day with as little as 20µg of material per reaction.
'We are excited about how this technique could encourage the use of new chemistries in drug discovery,' says Dreher. 'Medicinal chemists tend to steer towards the reactions they can trust as there’s little time and material for reactions that might fail. We hope that, initially, the adoption of this approach can help medicinal chemists try out a new reaction on their complex substrate without burning up time and material.'
'You have to make the molecule to test your hypothesis of what it might do so you need a reaction that works – some reactions fail more than 50% of the time on drug-like substrates and that disconnect spurred 

Friday, November 28, 2014

Nanotechnology Now - Press Release: "New Method for Production of Stable Antibacterial Fabrics without Color Change"






Antibacterial fabrics are usually produced by using silver nanoparticles. This method changes the color of the fabrics by creating brownish yellow shade in their structure. The aim of the research was to produce fabrics with high and stable antibacterial properties without changing the color. Zinc oxide/silicon dioxide nanocomposite was used in the structure
of the fabric coating to obtain the goal.

In this research, cotton fabrics were produced with antibacterial properties by synthesizing and loading of zinc oxide/silicon dioxide (SiO2) nanocomposite on it. In this research, nanoparticles were synthesized through in-situ process by using two different methods on the structure of cotton fabrics. In one of the methods, zinc oxide nanoparticles were firstly synthesized in silicon dioxide solution, and the solution was next coated on the cotton fabrics. In the second method, the cotton fabrics were firstly coated with silicon dioxide and then zinc oxide nanoparticles were coated on its structure.




Results obtained from investigating cotton fabrics coated through the both methods confirmed that no bacteria have grown  on the fabrics. However, the fabrics produced through the first method (synthesis of nanoparticles and coating of the fabric) showed larger diameter of the bacteria-free area due to the spherical shape and stability of the nanoparticles. Thermal tests also showed that the samples produced through the first method contain the maximum amount of zinc oxide while they have the lowest primary degradation temperature.
  

Thursday, November 27, 2014

Fluorescent nanoprobe could become a universal, noninvasive method to identify and monitor tumors -- ScienceDaily

Researchers have developed a hybrid metal-polymer nanoparticle that lights up in the acidic environment surrounding tumor cells. Nonspecific probes that can identify any kind of tumor are extremely useful for monitoring the location and spread of cancer and the effects of treatment, as well as aiding initial diagnosis.
Ref : http://onlinelibrary.wiley.com/doi/10.1002/smll.201302765/abstract;jsessionid=CF63DFDE0FB5AEF1C0849FC569E055E9.f03t01

Fluorescent nanoprobe could become a universal, noninvasive method to identify and monitor tumors -- 

Wednesday, November 26, 2014

Cancer research may reduce side effects from chemotherapy

WSU professors Ramazan Asmatulu, Paul Wooley and Shang-You Yang -- along with several graduate students -- are collaborating on research that involves the use of nanotechnology in helping patients undergoing cancer treatment.
Nanotechnology is the creation and application of nanoscale materials. One nanoparticle is about 100,000 times smaller than a strand of hair.
With that technology, the group has created nanomaterials and developed a magnetic-targeted drug delivery system with the goal of localizing as much as possible the cancer drugs to the tumor sites and therefore decreasing the negative effects of the drugs on the body. They've targeted their research on patients with skin and breast cancer.
"Skin and breast cancer patients will be exposed with the lesser amount of cancer drugs, which have too many side effects," Asmatulu says.
So far, they have seen positive results in both "in vitro" studies (using petri dishes and test tubes) and "in vivo" studies (using mice). The group is in the final stages of receiving a patent from the study. In the future, they plan to apply the technology to humans.

Monday, November 24, 2014

Nanotechnology Now - Press Release: "Milk Protein Used in Production of Drug Nanocarriers"












Milk proteins have been used in the production of the nanocarrier. The production and evaluation of performance of the drug delivery system is at laboratorial stage at the moment.
Drugs that are currently used for the treatment of cancers, specially gastric cancer, have not been designed in a target delivery manner. Therefore, large amount of the drugs must be consumed during the treating process. In addition to its side effects, it causes patients with problems from financial point of view. Researchers tried in this study to design and produce oral target drug delivery system to treat gastric cancer by using milk proteins.

 In this research, one of the important proteins in milk entitled casein was used to carry a chemotherapy medicine. Optimal conditions for the production of drug system at nanometric scale were obtained by changing laboratory conditions such as protein or drug concentrations. The system shows interesting therapeutic properties against gastric cancer in comparison with usual drugs.


Results obtained from simulation of stomach and intestine media show that the system slowly releases drug from the nanocapsule due to the acidic environment of the stomach. It also shows much stronger and more interesting effects in comparison with oxaliplatin free drug (which has not 
been encapsulated) on gastric cancerous cells.

According to the researchers, studies are being carried out on increasing the target delivery properties of the system, and complementary tests are being carried out to produce the drug. Results of the research have been published in ANTI-CANCER AGENTS IN MEDICINAL CHEMISTRY, vol. 14, issue 6, 2014, pp. 892-900.







Friday, November 21, 2014

Nanotechnology Now - Press Release: "New Method for Production of Stable Antibacterial Fabrics without Color Change"


https://blogger.googleusercontent.com/img/proxy/AVvXsEj1hNORt2paj3VzdmE0wxZWrpPV6jq4j2emOwlDjMTXNP4luPEsHxNhDMyFr4irHg-gW9jleYMBkv_tGhJInxfB6trmWa2C-9cp2ENjMIPCssEEWdFdWY4x_Xpmg4WRXslHFWfYBS06nk9nVYS0bUFjQA=
Antibacterial fabrics are usually produced by using silver nanoparticles. This method changes the color of the fabrics by creating brownish yellow shade in their structure. The aim of the research was to produce fabrics with high and stable antibacterial properties without changing the color. Zinc oxide/silicon dioxide nanocomposite was used in the structure of the fabric coating to obtain the goal.

In this research, cotton fabrics were produced with antibacterial properties by synthesizing and loading of zinc oxide/silicon dioxide (SiO2) nanocomposite on it. In this research, nanoparticles were synthesized through in-situ process by using two different methods on the structure of cotton fabrics. In one of the methods, zinc oxide nanoparticles were firstly synthesized in silicon dioxide solution, and the solution was next coated on the cotton fabrics. In the second method, the cotton fabrics were firstly coated with silicon dioxide and then zinc oxide nanoparticles were coated on its structure.


Results obtained from investigating cotton fabrics coated through the both methods confirmed that no bacteria have grown on the fabrics. However, the fabrics produced through the first method (synthesis of nanoparticles and coating of the fabric) showed larger diameter of the bacteria-free area due to the spherical shape and stability of the nanoparticles. Thermal tests also showed that the samples produced through the first method contain the maximum amount of zinc oxide while they have the lowest primary degradation temperature.
  

Thursday, November 20, 2014

Nanotechnology Now - Press Release: "New Method for Production of Stable Antibacterial Fabrics without Color Change"



Antibacterial fabrics are usually produced by using silver nanoparticles. This method changes the color of the fabrics by creating brownish yellow shade in their structure. The aim of the research was to produce fabrics with high and stable antibacterial properties without changing the color. Zinc oxide/silicon dioxide nanocomposite was used in the structure

of the fabric coating to obtain the goal.


In this research, cotton fabrics were produced with antibacterial properties by synthesizing and loading of zinc oxide/silicon dioxide (SiO2) nanocomposite on it. In this research, nanoparticles were synthesized through in-situ process by using two different methods on the structure of cotton fabrics. In one of the methods, zinc oxide nanoparticles were firstly synthesized in silicon dioxide solution, and the solution was next coated on the cotton fabrics. In the second method, the cotton fabrics were firstly coated with silicon dioxide and then zinc oxide nanoparticles were coated on its structure.



Results obtained from investigating cotton fabrics coated through the both methods confirmed that no bacteria have grown on the fabrics. However, the fabrics produced through the first method (synthesis of nanoparticles and coating of the fabric) showed larger diameter of the bacteria-free area due to the spherical shape and stability of the nanoparticles. Thermal tests also showed that the samples produced through the first method contain the maximum amount of zinc oxide while they have the lowest primary degradation temperature.
  

Wednesday, November 19, 2014

Nanotechnology Now - Press Release: "Penn engineers efficiently 'mix' light at the nanoscale"


 Researchers at the University of Pennsylvania have engineered a nanowire system that could pave the way for this ability, combining two light waves to produce a third with a different frequency and using an optical cavity to amplify the intensity of the output to a usable level.



The study was led by Ritesh Agarwal, professor of materials science and engineering in Penn's School of Engineering and Applied Science, and Ming-Liang Ren, a post-doctoral researcher in his lab. Other members of the Agarwal lab, Wenjing Liu, Carlos O. Aspetti and Liaoxin Sun, contributed to the study.

It was published in Nature communications. Current computer systems represent bits of information -- the 1's and 0's of binary code -- with electricity. Circuit elements, such as transistors, operate on these electric signals, producing outputs that are dependent on their inputs. "Mixing two input signals to get a new output is the basis of computation," Agarwal said. "It's easy to do with electric signals, but it's not easy to do with light, as light waves don't normally interact with one another."

Tuesday, November 18, 2014

Nanotechnology Now - Press Release: "Arrowhead Files for Regulatory Permission to Begin Phase 1 Trial of RNAi Therapeutic ARC-AAT"

In continuation of my update on RNAi

Arrowhead Research Corporation is a biopharmaceutical company developing targeted RNAi therapeutics. The company is leveraging its proprietary Dynamic Polyconjugate delivery platform to develop targeted drugs based on the RNA interference mechanism that efficiently silences disease-causing genes. Arrowhead's pipeline includes ARC-520 for chronic hepatitis B virus, ARC-AAT for liver disease associated with Alpha-1 antitrypsin deficiency, and partner-based programs in obesity and oncology.

Nanotechnology Now - Press Release: "Graphene/nanotube hybrid benefits flexible solar cells: Rice University labs create novel electrode for dye-sensitized cells"

The Rice University lab of materials scientist Jun Lou created flexible dye-sensitized solar cells using a graphene/nanotube hybrid as the cathode, replacing more expensive platinum and brittle indium tin oxide.Credit: N3L Research Group/Rice University




The Rice lab of materials scientist Jun Lou created the new cathode, one of the two electrodes in batteries, from nanotubes that are seamlessly bonded to graphene and replaces the expensive and brittle platinum-based materials often used in earlier versions.

The discovery was reported online in the Royal Society of Chemistry's Journal of Materials Chemistry A.

Dye-sensitized solar cells have been in development since 1988 and have been the subject of countless high school chemistry class experiments. They employ cheap organic dyes, drawn  from the likes of raspberries, which cover conductive titanium dioxide particles. The dyes  absorb photons and produce electrons that flow out of the cell for use; a return line  completes the circuit to the cathode that combines with an iodine-based electrolyte to refresh the dye.

While they are not nearly as efficient as silicon-based solar cells in collecting sunlight and transforming it into electricity, dye-sensitized solar cells have advantages for many applications, according to co-lead author Pei Dong, a postdoctoral researcher in Lou's lab.

"The first is that they're low-cost, because they can be fabricated in a normal area," Dong said. "There's no need for a clean room. They're semi-transparent, so they can be applied to glass, and they can be used in dim light; they will even work on a cloudy day.

"Or indoors," Lou said. "One company commercializing dye-sensitized cells is embedding them in computer keyboards and mice so you never have to install batteries. Normal room light is sufficient to keep them alive."

The breakthrough extends a stream of nanotechnology research at Rice that began with chemist Robert Hauge's 2009 invention of a "flying carpet" technique to grow very long bundles of aligned carbon nanotubes. In his process, the nanotubes remained attached to the surface substrate but pushed the catalyst up as they grew.

The graphene/nanotube hybrid came along two years ago. Dubbed "James' bond" in honor of its inventor, Rice chemist James Tour, the hybrid features a seamless transition from graphene to nanotube. The graphene base is grown via chemical vapor deposition and a catalyst is arranged in a pattern on top. When heated again, carbon atoms in an aerosol feedstock attach themselves to the graphene at the catalyst, which lifts off and allows the new nanotubes to grow. When the nanotubes stop growing, the remaining catalyst (the "carpet") acts as a cap and keeps the nanotubes from tangling.

The hybrid material solves two issues that have held back commercial application of dye-sensitized solar cells, Lou said. First, the graphene and nanotubes are grown directly onto the nickel substrate that serves as an electrode, eliminating adhesion issues that plagued the transfer of platinum catalysts to common electrodes like transparent conducting oxide.

Second, the hybrid also has less contact resistance with the electrolyte, allowing electrons to flow more freely. The new cathode's charge-transfer resistance, which determines how well electrons cross from the electrode to the electrolyte, was found to be 20 times smaller than for platinum-based cathodes, Lou said.

The key appears to be the hybrid's huge surface area, estimated at more than 2,000 square meters per gram. With no interruption in the atomic bonds between nanotubes and graphene, the material's entire area, inside and out, becomes one large surface. This gives the electrolyte plenty of opportunity to make contact and provides a highly conductive path for electrons.



Friday, October 31, 2014

Breakthrough in molecular electronics paves way for new generation of DNA-based computer circuits



Paving the way for a new generation of DNA-based computer circuits: Prof. Danny Porath, the Etta and Paul Schankerman Professor in Molecular Biomedicine at the Hebrew University of Jerusalem.

In a paper published today in Nature Nanotechnology, an international group of scientists announced the most significant breakthrough in a decade toward developing DNA-based electrical circuits.

The central technological revolution of the 20th century was the development of computers, leading to the communication and Internet era. The main measure of this evolution is miniaturization: making our machines smaller. A computer with the memory of the average laptop today was the size of a tennis court in the 1970s.
Yet while scientists made great strides in reducing of the size of individual computer components through microelectronics, they have been less successful at reducing the distance between transistors, the main element of our computers. These spaces between transistors have been much more challenging and extremely expensive to miniaturize -- an obstacle that limits the future development of computers.
Molecular electronics, which uses molecules as building blocks for the fabrication of electronic components, was seen as the ultimate solution to the miniaturization challenge. However, to date, no one has actually been able to make complex electrical circuits using molecules. The only known molecules that can be pre-designed to self-assemble into complex miniature circuits, which could in turn be used in computers, are DNA molecules. Nevertheless, so far no one has been able to demonstrate reliably and quantitatively the flow of electrical current through long DNA molecules.
Now, an international group led by Prof. Danny Porath of the Hebrew University of Jerusalem reports reproducible and quantitative measurements of electricity flow through long molecules made of four DNA strands, signaling a significant breakthrough towards the development of DNA-based electrical circuits. The research, which could re-ignite interest in the use of DNA-based wires and devices in the development of programmable circuits, appears in the journal Nature Nanotechnologyunder the title "Long-range charge transport in single G-quadruplex DNA molecules."
Prof. Porath is affiliated with the Hebrew University's Institute of Chemistry and its Center for Nanoscience and Nanotechnology. The molecules were produced by the group of Alexander Kotlyar from Tel Aviv University, who has been collaborating with Porath for 15 years. The measurements were performed mainly by Gideon Livshits, a PhD student in the Porath group, who carried the project forward with great creativity, initiative and determination. The research was carried out in collaboration with groups from Denmark, Spain, US, Italy and Cyprus.

Thursday, October 30, 2014

New nanodevice to improve cancer treatment monitoring


In less than a minute, a miniature device can measure a patient's blood for methotrexate, a commonly used but potentially toxic cancer drug. Just as accurate and ten times less expensive than equipment currently used in hospitals, this nanoscale device has an optical system that can rapidly gauge the optimal dose of methotrexate a patient needs, while minimizing the drug's adverse effects.

The gold nanonparticules on the surface of this receiving tab modify the colour of light detected by the instrument. The captured colour perfectly reflects the exact concentration of the medication in the blood sample. Les nanoparticules d'or situées à la surface de la languette réceptrice modifient la couleur de la lumière détectée par l'instrument. La couleur captée reflète la concentration exacte du médicament contenu dans l'échantillon sanguin.

New material advances tissue engineering, drug delivery

Researchers at the New York University Polytechnic School of Engineering have broken new ground in the development of proteins that form specialized fibers used in medicine and nanotechnology. For as long as scientists have been able to create new proteins that are capable of self-assembling into fibers, their work has taken place on the nanoscale. For the first time, this achievement has been realized on the microscale—a leap of magnitude in size that presents significant new opportunities for using engineered protein fibers.

Jin Kim Montclare, an associate professor of chemical and biomolecular engineering at the NYU School of Engineering, led a group of researchers who published the results of successful trials in the creation of engineered microfiber proteins in the journal Biomacromolecules.

Many materials used in medicine and nanotechnology rely on proteins engineered to form fibers with specific properties. For example, the scaffolds used in tissue engineering depend on engineered fibers, as do the nanowires used in biosensors. These fibers can also be bound with small molecules of therapeutic compounds and used in drug delivery.

Tuesday, October 28, 2014

Tiny nano-sized particles may play major role in detecting, tracking breast cancer

Exosomes, tiny, virus-sized particles released by cancer cells, can bioengineer micro-RNA (miRNA) molecules resulting in tumor growth. They do so with the help of proteins, such as one named Dicer. New research from The University of Texas MD Anderson Cancer Center suggests Dicer may also serve as a biomarker for breast cancer and possibly open up new avenues for diagnosis and treatment. Results from the investigation were published in today's issue of Cancer Cell.

"Exosomes derived from cells and blood serum of patients with breast cancer, have been shown to initiate tumor growth in non-tumor-forming cells when Dicer and other proteins associated with the development of miRNAs are present," said Raghu Kalluri, M.D., Ph.D., chair of the department of cancer biology at MD Anderson. "These findings offer opportunities for the development of exosomes-based biomarkers and shed insight into the mechanisms of how cancer spreads."

Ref : http://www.mdanderson.org/newsroom/news-releases/2014/breast-cancer-exosomes-cancer-progression.html

Wednesday, October 22, 2014

Tuning light to kill deep cancer tumors


An international group of scientists has combined a new type of nanoparticle with an FDA-approved photodynamic therapy to effectively kill deep-set cancer cells in vivo with minimal damage to surrounding tissue and fewer side effects than chemotherapy. This promising new treatment strategy could expand the current use of photodynamic therapies to access deep-set cancer tumors.
"We are very excited at the potential for clinical practice using our enhanced red-emission nanoparticles combined with FDA-approved photodynamic drug therapy to kill malignant cells in deeper tumors," said Dr. Han, lead author of the study and assistant professor of biochemistry and molecular pharmacology at UMMS. "We have been able to do this with biocompatible low-power, deep-tissue-penetrating 980-nm near-infrared light."
In photodynamic therapy, also known as PDT, the patient is given a non-toxic light-sensitive drug, which is absorbed by all the body's cells, including the cancerous ones. Red laser lights specifically tuned to the drug molecules are then selectively turned on the tumor area. When the red light interacts with the photosensitive drug, it produces a highly reactive form of oxygen (singlet oxygen) that kills the malignant cancer cells while leaving most neighboring cells unharmed.
Because of the limited ability of the red light to penetrate tissue, however, current photodynamic therapies are only used for skin cancer or lesions in very shallow tissue. The ability to reach deeper set cancer cells could extend the use of photodynamic therapies.
In research published online by the journal ACS Nano of the American Chemical Society, Han and colleagues describe a novel strategy that makes use of a new class of upconverting nanoparticles (UCNPs), a billionth of a meter in size, which can act as a kind of relay station. These UCNPs are administered along with the photodynamic drug and convert deep penetrating near-infrared light into the visible red light that is needed in photodynamic therapies to activate the cancer-killing drug.
To achieve this light conversion, Han and colleagues engineered a UCNP to have better emissions in the red part of the spectrum by coating the nanoparticles with calcium fluoride and increasing the doping of the nanoparticles with ytterbium.
In their experiments, the researchers used the low-cost, FDA-approved photosensitizer drug aminolevulinic acid and combined it with the augmented red-emission UCNPs they had developed. Near-infrared light was then turned on the tumor location. Han and colleagues showed that the UCNPs successfully converted the near-infrared light into red light and activated the photodynamic drug at levels deeper than can be currently achieved with photodynamic therapy methods. Performed in both in vitro and with animal models, the combination therapy showed an improved destruction of the cancerous tumor using lower laser power.
Yong Zhang, PhD, chair professor of National University of Singapore and a leader in the development and application of upconversion nanoparticles, who was not involved in the study, said that by successfully engineering amplified red emissions in these nanoparticles, the research team has created the deepest-ever photodynamic therapy using an FDA-approved drug.
"This therapy has great promise as a noninvasive killer for malignant tumors that are beyond 1 cm in depth -- breast cancer, lung cancer, and colon cancer, for example -- without the side-effects of chemotherapy," Zhang said.
Han said, "This approach is an exciting new development for cancer treatment that is both effective and nontoxic, and it also opens up new opportunities for using the augmented red-emission nanoparticles in other photonic and biophotonic applications.
Ref : http://www.umassmed.edu/news/research/


Tuesday, October 21, 2014

Facetless crystals that mimic starfish shells could advance 3-D-printing pills

Facetless crystals that mimic starfish shells could advance 3-D-printing pills 

Ultra-fast charging batteries that can be 70% recharged in just two minutes


Scientists have developed a new battery that can be recharged up to 70 per cent in only 2 minutes. The battery will also have a longer lifespan of over 20 years. Expected to be the next big thing in battery technology, this breakthrough has a wide-ranging impact on many industries, especially for electric vehicles which are currently inhibited by long recharge times of over 4 hours and the limited lifespan of batteries.
Scientists from Nanyang Technological University (NTU Singapore) have developed a new battery that can be recharged up to 70 per cent in only 2 minutes. The battery will also have a longer lifespan of over 20 years.
Expected to be the next big thing in battery technology, this breakthrough has a wide-ranging impact on many industries, especially for electric vehicles which are currently inhibited by long recharge times of over 4 hours and the limited lifespan of batteries.
This next generation of lithium-ion batteries will enable electric vehicles to charge 20 times faster than the current technology. With it, electric vehicles will also be able to do away with frequent battery replacements. The new battery will be able to endure more than 10,000 charging cycles -- 20 times more than the current 500 cycles of today's batteries.
NTU Singapore's scientists replaced the traditional graphite used for the anode (negative pole) in lithium-ion batteries with a new gel material made from titanium dioxide, an abundant, cheap and safe material found in soil. It is commonly used as a food additive or in sunscreen lotions to absorb harmful ultraviolet rays.
Naturally found in a spherical shape, NTU Singapore developed a simple method to turn titanium dioxide particles into tiny nanotubes that are a thousand times thinner than the diameter of a human hair.
This nanostructure is what helps to speeds up the chemical reactions taking place in the new battery, allowing for superfast charging.
Invented by Associate Professor Chen Xiaodong from the School of Materials Science and Engineering at NTU Singapore, the science behind the formation of the new titanium dioxide gel was published in the latest issue of Advanced Materials, a leading international scientific journal in materials science.
NTU professor Rachid Yazami, who was the co-inventor of the lithium-graphite anode 34 years ago that is used in most lithium-ion batteries today, said Prof Chen's invention is the next big leap in battery technology.
"While the cost of lithium-ion batteries has been significantly reduced and its performance improved since Sony commercialised it in 1991, the market is fast expanding towards new applications in electric mobility and energy storage," said Prof Yazami.
"There is still room for improvement and one such key area is the power density -- how much power can be stored in a certain amount of space -- which directly relates to the fast charge ability. Ideally, the charge time for batteries in electric vehicles should be less than 15 minutes, which Prof Chen's nanostructured anode has proven to do."
Prof Yazami, who is Prof Chen's colleague at NTU Singapore, is not part of this research project and is currently developing new types of batteries for electric vehicle applications at the Energy Research Institute at NTU (ERI@N).
Commercialisation of technology
Moving forward, Prof Chen's research team will be applying for a Proof-of-Concept grant to build a large-scale battery prototype. The patented technology has already attracted interest from the industry.........