#Toxic nanoparticles might be entering human food supplyover the last few years the use of nanomaterials for water treatment food packaging pesticides cosmetics
For example farmers have used silver nanoparticles as a pesticide because of their capability to suppress the growth of harmful organisms.
In a new study researchers at the University of Missouri have developed a reliable method for detecting silver nanoparticles in fresh produce and other food products.
More than 1000 products on the market are based nanotechnology products said Mengshi Lin associate professor of food science in the MU College of Agriculture Food and Natural resources.
because we do not know the toxicity of the nanoparticles. Our goal is to detect identify
and quantify these nanoparticles in food and food products and study their toxicity as soon as possible. Lin and his colleagues including MU scientists Azlin Mustapha
and Bongkosh Vardhanabhuti studied the residue and penetration of silver nanoparticles on pear skin. First the scientists immersed the pears in a silver nanoparticle solution similar to pesticide application.
The pears were washed then and rinsed repeatedly. Results showed that four days after the treatment
and rinsing silver nanoparticles were attached still to the skin and the smaller particles were able to penetrate the skin
The penetration of silver nanoparticles is dangerous to consumers because they have the ability to relocate in the human body after digestion Lin said.
Therefore smaller nanoparticles may be more harmful to consumers than larger counterparts. When ingested nanoparticles pass into the blood
and lymph system circulate through the body and reach potentially sensitive sites such as the spleen brain liver and heart.
The growing trend to use other types of nanoparticles has revolutionized the food industry by enhancing flavors improving supplement delivery keeping food fresh longer
However researchers worry that the use of silver nanoparticles could harm the human body. This study provides a promising approach for detecting the contamination of silver nanoparticles in food crops
or other agricultural products Lin said. Members of Lin's research team also included Zhong Zang a food science graduate student.
Immune system attacka unique nanoscale drug that can carry a variety of weapons and sneak into cancer cells to break them down from the inside has a new component:
The research team developing the drug--led by scientists at the Nanomedicine Research center part of the Maxine Dunitz Neurosurgical Institute in the Department of Neurosurgery at Cedars-Sinai Medical center--conducted the study in laboratory mice with implanted human
and a gene of Herceptin said Julia Y. Ljubimova MD Phd professor of neurosurgery and biomedical sciences and director of the Nanomedicine Research center.
We believe this is the first time a drug has been designed for nano-immunology anticancer treatment Ljubimova said.
Nano researchers manipulate substances and materials at the atomic level generally working with substances smaller than 100 nanometers.
Cedars-Sinai's nanoconjugate is estimated to be about 27 nanometers wide. A human hair is 80000 to 100000 nanometers wide.
Story Source: The above story is provided based on materials by Cedars-Sinai Medical center. Note: Materials may be edited for content and length.
Journal Reference e
#NASA fire towers in space watch for wildfires on the risethe Black forest wildfire this June was one of the most destructive in Colorado history in terms of homes lost.
#Nanomaterials: Sized-up for strengthexperiments and numerical simulations show that miniaturized ultra-small platinum cylinders weaken
The team used a combined experimental and computational approach to overcome the knowledge gap hindering the production of reliable micro-and nano-electromechanical devices.
Team member Zhaoxuan Wu from IHPC explains that this approach allowed them to reduce the size of the experimental samples to tens of nanometers.
It also allowed them to perform large-scale atomic simulations on comparable nanostructures which provided a means to directly link structure and mechanical properties.
and perforating it with nano-to micrometer-sized cylindrical holes. Next they synthesized the metal nanostructures in these holes from a platinum precursor solution.
Dissolving the template then produced nanopillars that displayed well-defined grains of similar sizes and grain boundaries or interfaces Compression experiments on the nanostructures showed that the thinnest nanopillars remained almost cylindrical under low pressure
but weakened dramatically and bent irreversibly under high pressure. In contrast wider nanopillars exhibited a smoother deformation and delayed failure.
Moreover the simulations indicated the origin within the nanostructures of the irreversible deformation and dislocation motions.
and oxidations on the mechanical behavior of nanomaterials says Wu. Story Source: The above story is provided based on materials by The Agency for Science Technology and Research (A*STAR.
#Off-grid sterilization with solar steamrice University nanotechnology researchers have unveiled a solar-powered sterilization system that could be a boon for more than 2. 5 billion people who lack adequate sanitation.
The solar steam sterilization system uses nanomaterials to convert as much as 80 percent of the energy in sunlight into germ-killing heat.
Solar steam's efficiency comes from light-harvesting nanoparticles that were created at LANP by Rice graduate student Oara Neumann the lead author on the PNAS study.
The Tour lab pioneered the bulk manufacture of single-atom-thick graphene nanoribbons in 2009 with the discovery that carbon nanotubes could be unzipped chemically into long thin sheets.
The width of the rings which ranged from 10 to 450 nanometers also affects their electronic properties
If we can consistently make 10-nanometer ribbons we can begin to gate them and turn them into low-voltage transistors he said.
#Broadband photodetector for polarized lightusing carpets of aligned carbon nanotubes researchers from Rice university and Sandia National Laboratories have created a solid-state electronic device that is hardwired to detect polarized light across a broad swath of the visible and infrared spectrum.
The research is available online from the American Chemical Society's journal ACS Nano. Detecting polarized light is said extremely useful Rice's Junichiro Kono professor of electrical
Rice's new photodetector is the latest development from a collaboration between Rice and Sandia under Sandia's National Institute for Nano Engineering program
In February Kono L onard and colleagues described a new method for making photodetectors from carpets of carbon nanotubes--long narrow tubes of pure carbon that are about as wide as a strand of DNA.
The nanotube carpets used in the photodetectors are grown in the lab of Rice chemist Robert Hauge who pioneered a process for growing densely packed nanotubes on flat surfaces.
Xiaowei He a graduate student in Kono's group found a way to use Teflon film to flatten these tightly packed nanotubes
Each carpet contains dozens of varieties of nanotubes and about two-thirds of the varieties are semiconductors.
Because each of the semiconducting varieties interacts with a specific wavelength of light Kono's team was able to show in its earlier work that the flattened aligned carpets of nanotubes could serve as broad-spectrum photodetectors.
In the ACS Nano study lead author He used chemicals called dopants to alter the electrical properties of the nanotube carpets.
The research was supported by the Lockheed martin Advanced Nanotechnology Center of Excellence at Rice university the National Science Foundation the Department of energy the Welch Foundation and the National Institute for Nano Engineering and the Laboratory Directed Research and development
and creates a channel of pure metallic phase silicon that is less than five nanometers wide. Normal operating voltages can repeatedly break
We've already demonstrated the native sub-5-nanometer filament which is going to work with the smallest line size industry can make.
The pitch particles are two nanometers in size which makes our flakes about ten thousand times larger said Rice graduate student Changsheng Xiang lead author of the new paper.
The wet-spinning process is similar to one recently used to create highly conductive fibers made of nanotubes but in this case Xiang just used water as the solvent rather than a super acid.
#Unzipped nanotubes unlock potential for batteriesresearchers at Rice university have come up with a new way to boost the efficiency of the ubiquitous lithium ion (LI) battery by employing ribbons of graphene that start as carbon nanotubes.
The research appeared this week in the American Chemical Society journal ACS Nano. Better batteries are desired greatly by everyone who carries a cellphone or computer or drives an electric car.
Tour and his colleagues developed a method for unzipping nanotubes into GNRS revealed in a 2009 cover story in Nature.
In the new experiments the Rice lab mixed graphene nanoribbons and tin oxide particles about 10 nanometers wide in a slurry with a cellulose gum binder and a bit of water spread it on a current collector
but also help deliver lithium ions to the nanoparticles. Lab tests showed initial charge capacities of more than 1520 milliamp hours per gram (mah/g). Over repeated charge-discharge cycles the material settled into a solid 825 mah/g. It took about two months to go through 50
Graphene nanoribbons make a terrific framework that keeps the tin oxide nanoparticles dispersed and keeps them from fragmenting during cycling he said.
Since the tin oxide particles are only a few nanometers in size and permitted to remain that way by being dispersed on GNR surfaces the volume changes in the nanoparticles are not dramatic.
GNRS also provide a lightweight conductive framework with their high aspect ratios and extreme thinness. The researchers pointed out the work is a starting point for exploring the composites made from GNRS and other transition metal oxides for lithium storage applications.
Lin said the lab plans to build batteries with other metallic nanoparticles to test their cycling and storage capacities.
That's still only about the width of a human hair but in the nanoscale realm it's big enough to work with he said.
The Welch Foundation the National Science Foundation (NSF) the U s army Research Office the U s. Office of Naval Research the Nanoelectronics Research Corporation and the Department of energy supported the work.
since graphene (and its cousin material carbon nanotubes) is the only material with the high strength-to-weight ratio required for this kind of hypothetical application.
The discovery is detailed online in the American Chemical Society journal Nano Letters. While commercial silicon-based solar cells turn about 20 percent of sunlight into electricity and experimental units top 25 percent there's been an undercurrent of research into polymer-based cells that could greatly reduce the cost
The Rice lab discovered a block copolymer--P3ht-b-PFTBT--that separates into bands that are about 16 nanometers wide.
#Diamonds, nanotubes find common ground in graphenewhat may be the ultimate heat sink is only possible because of yet another astounding capability of graphene.
The one-atom-thick form of carbon can act as a go-between that allows vertically aligned carbon nanotubes to grow on nearly anything.
A diamond film/graphene/nanotube structure was one result of new research carried out by scientists at Rice university
when graphene is used as a middleman surfaces considered unusable as substrates for carbon nanotube growth now have the potential to do so.
The same could be said of carbon nanotubes which are basically rolled-up tubes of graphene. A vertically aligned forest of carbon nanotubes grown on diamond would disperse heat like a traditional heat sink but with millions of fins.
Such an ultrathin array could save space in small microprocessor-based devices. Further work along these lines could produce such structures as patterned nanotube arrays on diamond that could be utilized in electronic devices Ajayan said.
Graphene and metallic nanotubes are also highly conductive in combination with metallic substrates they may also have advanced uses in electronics he said.
To test their ideas the Honda team grew various types of graphene on copper foil by standard chemical vapor deposition.
which the nanotubes grow. The researchers think graphene facilitates nanotube growth by keeping the catalyst particles from clumping.
Ajayan thinks the extreme thinness of graphene does the trick. In a previous study the Rice lab found graphene shows materials coated with graphene can get wet
Testing found that the graphene layer remains intact between the nanotube forest and the diamond or other substrate.
This multidisciplinary collaboration by the Energy Frontier Research center at Columbia University with Cornell University's Kavli Institute for Nanoscale Science focused on molybdenum disulfide because of its potential to create anything from highly efficient flexible solar cells to conformable
We've made a lot of progress in controlling the growth of this new'wonder'nanomaterial and are now developing techniques to integrate it into many new technologies Hone adds.
The electron microscopy was performed by atomic imaging experts in the David Muller lab at Cornell University's School of Applied and Engineering Physics and the Kavli Institute at Cornell for Nanoscale Science.
University of Louisville researchers have uncovered how to create nanoparticles using natural lipids derived from grapefruit
These nanoparticles which we've named grapefruit-derived nanovectors (GNVS) are derived from an edible plant
and are much cheaper to produce at large scale than nanoparticles made from synthetic materials Zhang said.
The therapeutic potential of grapefruit derived nanoparticles was validated further through a Phase 1 clinical trial for treatment of colon cancer patients.
So far researchers have observed no toxicity in the patients who orally took the anti-inflammatory agent curcumin encapsulated in grapefruit nanoparticles.
It made sense for us to consider eatable plants as a mechanism to create medical nanoparticles as a potential nontoxic therapeutic delivery vehicle.
In addition to grapefruit Zhang and his team analyzed the nanoparticles from tomatoes and grapes. Grapefruits were chosen for further exploration
Visually arrays of these nanostructures very much resemble an artificial forest. Yang who also holds appointments with the University of California Berkeley's Chemistry department
and Department of Materials Science and Engineering is the corresponding author of a paper describing this research in the journal NANO Letters.
The paper is titled A Fully Integrated Nanosystem of Semiconductor Nanowires for Direct Solar Water Splitting.
We've integrated our nanowire nanoscale heterostructure into a functional system that mimics the integration in chloroplasts
The photo-generated electrons in the silicon nanowires migrate to the surface and reduce protons to generate hydrogen
while the photo-generated holes in the titanium oxide nanowires oxidize water to evolve oxygen molecules.
'However the number (approximately 10-15) and the size of these grains (about 6-10 nanometers) naturally limits the maximum density at
Prior to the record-setting experiment a preliminary scaling study was conducted at the Rensselaer supercomputing center the Computational Center for Nanotechnology Innovations (CCNI.
The researchers had intended to quantify results seen a few years ago by former Rice graduate student Brent Carey who subjected a nanotube-infused polymer to a process called repetitive dynamic compression.
They had planned originally to study liquid crystal silicone/nanotube composites similar to what Carey tested but decided to look at liquid crystal silicones without the nanotubes first.
It's always better to start simple Verduzco said. Silicones are made of long flexible chains that are entangled
#Nanostructures improve the efficiency of solar cellsresearchers have been able to improve the efficiency of solar cells by coating the cell surface with extremely small nanoscale structures.
The nanostructured black silicon coating features very low reflectivity meaning that a larger portion of the Sun's radiation can be exploited.
A nanostructured hybrid of these two materials however remained active and stable even after 500 hours of testing in a highly acidic environment.
and the Center for Functional Nanomaterials (CFN) are reported also in the paper and provide further details underlying the high performance of this new catalyst.
simulation studies on the effectiveness of methane capture using two different materials--liquid solvents and nanoporous zeolites (porous materials commonly used as commercial adsorbents).
However a systematic screening of around 100000 zeolite structures uncovered a few nanoporous candidates that appear technologically promising.
The key enzymes immobilized on the magnetic nanoparticles can easily be recycled using a magnetic force. Zhang designed the experiments
-and nanotechnology said Professor Isiah Warner Ph d. of Louisiana State university (LSU) Baton rouge who led the scientific team that developed the first GUMBOS five years ago.
Unlike some products of the revolution in nanomaterials and nanotechnology nanogumbos can be designed for specific uses rather than simply adapted for a particular use after being synthesized in the lab. Warner pointed out for instance that scientists are working on various types of nanoparticles for use in nanomedicine especially to diagnose
In diagnosing cancer nanoparticles with cancer-seeking properties might be injected into a patient before a medical scan.
For treating the disease nanoparticles would preferentially collect in and destroy only the abnormal cells sparing healthy tissue from the damage that triggers side effects with existing cancer chemotherapy.
Warner said that nanogumbos technology allows scientists to produce new nanoparticles in a focused way such that these particles are produced for specific uses from the beginning.
Some nanomaterials already use this approach. However many nanoparticles developed so far for medical use for instance must be coated with other materials to provide the desired medicinal property.
With GUMBOS technology nanoparticles can have desired the property incorporated directly into the nanomaterial he explained.
For example some nanoparticles are used as the drug delivery vehicle. We can make nanogumbos that are both the drug
and the drug delivery vehicle he said. Warner cited as one example a newly developed nanogumbos material with a provisional patent application filed that his team at LSU foresees as a lead in possible development of new anticancer drugs.
and as nanosensors and biomedical imaging reagents Warner pointed out. Thus far the scientists have made nanogumbos in many shapes and sizes.
Convergence of nanotechnology and microbiology: Emerging opportunities for water disinfection integrated urban water management and risk assessment1.
alvarez@rice. eduthe extraordinary properties of some nanomaterials offer leapfrogging opportunities to develop next-generation applications for drinking water disinfection
The multifunctional and high-efficiency processes enabled by nanotechnology are broadly applicable in both industrialized and developing countries by enabling the retrofitting of aging infrastructure
On the other hand the use of nanomaterials in commercial products is outpacing the development of knowledge and regulations to mitigate potential risks associated with their release to the environment.
Therefore it is important to understand how engineered nanoparticles interact with microorganisms which form the basis of all known ecosystems
The convergence of nanotechnology with environmental microbiology could expand the limits of technology enhance global health through safer water reuse
This presentation will consider the antibacterial mechanisms of various nanomaterials within the context of environmental implications and applications.
Research needs to steward ecologically responsible nanotechnology will also be discussed. Confronting the water challenge: Dow technologies increase the flow1.
#Engineering algae to make the wonder material nanocellulose for biofuels and moregenes from the family of bacteria that produce vinegar Kombucha tea and nata de coco have become stars in a project
--which scientists today said has reached an advanced stage--that would turn algae into solar-powered factories for producing the wonder material nanocellulose.
Their report on advances in getting those genes to produce fully functional nanocellulose was part of the 245th National Meeting
Ph d. We will have plants that produce nanocellulose abundantly and inexpensively. It can become the raw material for sustainable production of biofuels and many other products.
While producing nanocellulose the algae will absorb carbon dioxide the main greenhouse gas linked to global warming.
Brown who has pioneered research in the field for more than 40 years spoke at the First International Symposium on Nanocellulose part of the ACS meeting.
and secrete cellulose in its native nanostructure form of microfibrils. At this level nanometer-scale fibrils are very hydrophilic
and look like jelly. A nanometer is one-millionth the thickness of a U s. dime. Nevertheless cellulose shares the unique properties of other nanometer-sized materials--properties much different from large quantities of the same material.
Nanocellulose-based materials can be stronger than steel and stiffer than Kevlar. Great strength light weight
and other advantages has fostered interest in using it in everything from lightweight armor and ballistic glass to wound dressings and scaffolds for growing replacement organs for transplantation.
In the 1800s French scientist Louis Pasteur first discovered that vinegar-making bacteria make a sort of moist skin swollen gelatinous and slippery--a skin now known as bacterial nanocellulose.
Nanocellulose made by bacteria has advantages including ease of production and high purity that fostered the kind of scientific excitement reflected in the first international symposium on the topic Brown pointed out.
Brown recalled that in 2001 a discovery by David Nobles Ph d. a member of the research team at the University of Texas at Austin refocused their research on nanocellulose but with a different microbe.
Nobles established that several kinds of blue-green algae which are mainly photosynthetic bacteria much like the vinegar-making bacteria in basic structure;
however these blue-green algae or cyanobacteria as they are called can produce nanocellulose. One of the largest problems with cyanobacterial nanocellulose is that it is made not in abundant amounts in nature.
If it could be scaled up Brown describes this as one of the most important discoveries in plant biology.
Since the 1970s Brown and colleagues began focusing on Acetobacter xylinum (A. xylinum) a bacterium that secretes nanocellulose directly into the culture medium
In the 1980s and 1990s Brown's team sequenced the first nanocellulose genes from A. xylinum.
They also pinpointed the genes involved in polymerizing nanocellulose (linking its molecules together into long chains)
and in crystallizing (giving nanocellulose the final touches needed for it to remain stable and functional).
or other bacteria engineered with those genes to make commercial amounts of nanocellulose. Bacteria for instance would need a high-purity broth of food
Those drawbacks shifted their focus on engineering the A. xylinum nanocellulose genes into Nobles'blue-green algae. Brown explained that algae have multiple advantages for producing nanocellulose.
Cyanobacteria for instance make their own nutrients from sunlight and water and remove carbon dioxide from the atmosphere while doing so.
Cyanobacteria also have the potential to release nanocellulose into their surroundings much like A. xylinum making it easier to harvest.
In his report at the ACS meeting Brown described how his team already has engineered genetically the cyanobacteria to produce one form of nanocellulose the long-chain
And they are moving ahead with the next step engineering the cyanobacteria to synthesize a more complete form of nanocellulose one that is a polymer with a crystalline architecture.
Brown expressly pointed out that one of the major barriers to commercializing nanocellulose fuels involves national policy and politics rather than science.
Calculations by the Rice team of theoretical physicist Boris Yakobson and his colleagues in China were reported this month in the American Chemical Society journal Nano Letters.
However cellulose nanomaterials made from wood are green renewable and sustainable. The substrates have a low surface roughness of only about two nanometers.
Our next steps will be to work toward improving the power conversion efficiency over 10 percent levels similar to solar cells fabricated on glass
There's also another positive impact of using natural products to create cellulose nanomaterials. The nation's forest product industry projects that tens of millions of tons of them could be produced once large-scale production begins potentially in the next five years.
The research appears online this month in the American Chemical Society journal Nano Letters. The ribbons created at Rice are thousands of times thinner than a sheet of paper yet have potential that far outweighs current materials for their ability to charge
The ribbons with a weblike coating of graphene were only about 10 nanometers thick up to 600 nanometers wide and tens of micrometers in length.
#X-rays reveal uptake of nanoparticles by soybean cropsmetals contained in nanoparticles can enter into the food chain.
Scientists have traced for the first time the nanoparticles taken up from the soil by crop plants and analysed the chemical states of their metallic elements.
The results contribute to the controversial debate on plant toxicity of nanoparticles and whether engineered nanoparticles can enter into the food chain.
The study was published on 6 february 2013 in the journal ACS Nano. The international research team was led by Jorge Gardea-Torresdey from the University of Texas in El paso
and also comprised scientists from the University of California in Santa barbara the SLAC National Accelerator Laboratory in Stanford (California) and the European Synchrotron Radiation Facility in Grenoble (France).
Nanoparticles are present everywhere for example in the fine dust of wood fires. Even a simple chemical compound behaves differently as a nanoparticle mostly due to the increased specific surface area and reactivity.
These appealing properties Are engineered why so-called Nanoparticles (ENPS) are used now widely in industrial processing and consumer goods.
At the same time their high reactivity has raised concerns about their fate transport and toxicity in the environment.
This is why it is very important to study the interactions of crops with nanoparticles as their possible translocation into the food chain starts here. says Jorge Gardea-Torresdey a Professor
which the plants were grown was mixed with zinc oxide (Zno) and cerium dioxide (Ceo2 nanoceria) nanoparticles which are among the most highly used in industry.
i e. whether they were still bound to nanoparticles or had dissolved and bound with plant tissue. We used X-ray beams 1000 times thinner than a human hair and the way in
and whether they formed part of a nanoparticle in the plant or not. says Hiram Castillo a scientist at the ESRF in Grenoble.
and pods was in the same chemical state as in the nanoparticles. However part of the cerium had changed its oxidation state from Ce (IV) to Ce (III) which can alter the chemical reactivity of the nanoparticles.
Zinc was detected in nodules stems and pods in concentrations higher than in a control group of plants.
The spectral analysis did not show the presence of zinc in the plants bound as Zno nanoparticles which means that the zinc in the nanoparticles had been biotransformed.
As zinc is present in most plants it didn't come as a surprise that zinc from the nanoparticles in the soil can enter into the plant tissue.
which when used in nanoparticles might pose a real threat. says Hiram Castillo. Our results have shown also that Ceo2 nanoparticles can be taken up by food crops when present in the soil.
Cerium has no chemical partner in the plant tissue and is not biotransformed in the soya bean
One must keep in mind that once engineered nanoparticles enter the food chain this is an accumulative process.
not only whether man-made nanoparticles can be taken up from soil but also how they are biotransformed in the plants. concludes Jorge Gardea-Torresdey.
Arturo A. Keller of the University of California in Santa barbara and Co-Director of the UC Center for the Environmental Implications of Nanotechnology who was involved not in this research comments:
Whilst we are not able to directly attribute nanoparticle ingestion to any particular disease or symptoms we know from the latest laboratory studies the potency some have in terms of infiltrating our cells and tissue and causing harm.
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