Cornell University: RESEARCHERS CREATE MATERIAL WITH “ARTIFICIAL METABOLISM”


Scientists just got one step closer to creating living machines — or at least machines that mimic biological life as we know it.

A new biomaterial built in a Cornell University bioengineering lab uses synthetic DNA to continuously and autonomously organize, assemble, and restructure itself in a process so similar to how biological cells and tissues grow that the researchers are calling “artificial metabolism,” according to researchpublished in Science Robotics last week.

 We Can Regrow It

It’s clear that the scientists are dancing around the idea of creating lifelike machinery. They stop short of straight-up claiming that their metabolizing biomaterial is alive, but the research begins by coyly listing the characteristics of life that the material exhibits — self-assembly, organization, and metabolism.

We are introducing a brand-new, lifelike material concept powered by its very own artificial metabolism,” Cornell engineer Dan Lui said in a university-published press release. “We are not making something that’s alive, but we are creating materials that are much more lifelike than have ever been seen before.”

Worming Along

The biomaterial mimics a biological organism’s endless metabolic cycle of taking in energy and replacing old cells. When placed in a nutrient-rich environment, the material grew in the direction of the raw materials and food it needed to thrive — not unlike how a developing brain’s neurons grow out in the direction of specific molecules.

Meanwhile, the material also let its tail end die off and decay, giving the appearance of a constantly-regrowing slime mold traveling around toward food.

While the little bio-blob isn’t alive, it does appear to move and grow like a living thing, suggesting that scientists are blurring the line between life and machine more and more.

READ MORE: FORGET ARTIFICIAL INTELLIGENCE; THINK ARTIFICIAL LIFE[Hackaday]

More on biomaterials: Scientists Manipulated a Material for Robots That Grows Like Human Skin

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Cornell University: Pore size influences nature of complex nanostructures – Materials for energy storage, biochemical sensors and electronics


The mere presence of void or empty spaces in porous two-dimensional molecules and materials leads to markedly different van der Waals interactions across a range of distances. Credit: Yan Yang and Robert DiStasio

Building at the nanoscale is not like building a house. Scientists often start with two-dimensional molecular layers and combine them to form complex three-dimensional architectures.

And instead of nails and screws, these structures are joined together by the attractive van der Waals forces that exist between objects at the nanoscale.

Van der Waals forces are critical in constructing  for energy storage, biochemical sensors and electronics, although they are weak when compared to chemical bonds. They also play a crucial role in , determining which drugs bind to the active sites in proteins.

In new research that could help inform development of new materials, Cornell chemists have found that the empty space (“pores”) present in two-dimensional molecular building blocks fundamentally changes the strength of these van der Waals forces, and can potentially alter the assembly of sophisticated nanostructures.

The findings represent an unexplored avenue toward governing the self-assembly of complex nanostructures from porous two-dimensional building blocks.

“We hope that a more complete understanding of these forces will aid in the discovery and development of novel materials with diverse functionalities, targeted properties, and potentially novel applications,” said Robert A. DiStasio Jr., assistant professor of chemistry in the College of Arts and Sciences.

In a paper titled “Influence of Pore Size on the van der Waals Interaction in Two-Dimensional Molecules and Materials,” published Jan. 14 in Physical Review Letters, DiStasio, graduate student Yan Yang and postdoctoral associate Ka Un Lao describe a series of mathematical models that address the question of how void space fundamentally affects the attractive physical forces which occur over nanoscale distances.

In three prototypical model systems, the researchers found that particular pore sizes lead to unexpected behavior in the  that govern van der Waals forces.

Further, they write, this behavior “can be tuned by varying the relative size and shape of these void spaces … [providing] new insight into the self-assembly and design of complex nanostructures.”

While strong covalent bonds are responsible for the formation of two-dimensional molecular layers, van der Waals interactions provide the main attractive  between the layers. As such, van der Waals forces are largely responsible for the self-assembly of the complex three-dimensional nanostructures that make up many of the advanced materials in use today.

The researchers demonstrated their findings with numerous two-dimensional systems, including covalent organic frameworks, which are endowed with adjustable and potentially very large pores.

“I am surprised that the complicated relationship between void space and van der Waals forces could be rationalized through such simple models,” said Yang. “In the same breath, I am really excited about our findings, as even  in the van der Waals forces can markedly impact the properties of molecules and materials.”

Explore further: Researchers refute textbook knowledge in molecular interactions

More information: Yan Yang et al, Influence of Pore Size on the van der Waals Interaction in Two-Dimensional Molecules and Materials, Physical Review Letters (2019).  DOI: 10.1103/PhysRevLett.122.026001 

New nanoparticle may aid cancer detection


Cellular Messenger Cornell 9-scientistsdiAn intricate pattern – a molecular model of the influenza virus. The influenza virion (as the infectious particle is called) is roughly spherical. It is an enveloped virus – that is, the outer layer is a lipid membrane which is taken from the host cell in which the virus multiplies. 

A new nanoparticle, at the cellular level, may reveal how cancer cells move to different locations in the human body. This process involves co-opting the human body’s inter-cellular delivery service.

The insight into the cellular messenger system comes from Weill Cornell Medicine scientists. The discovery is of importance since it could help medical scientists to understand how cancer cells can spread to various other locations.

 

With the research, the medics have used a novel technique called asymmetric flow field-flow fractionation. Through this the researchers were able to shift and sort a particular type of nano-sized particles termed exosomes. These particles are secreted by cancer cells and they are formed of DNA, RNA, fats and proteins.

 

Exosomes are cell-derived vesicles that are present in many cell fluids, including blood, and urine; they provide a means of intercellular communication and of transmission of macromolecules between cells. In medicine exosomes can potentially be used for prognosis, for therapy, and as biomarkers for health and disease.

 

By using the asymmetric flow field-flow fractionation, the scientists were able to separate out two distinct exosome subtypes. This has led to the discovery of the new type of nanoparticle. Asymmetrical flow field flow fractionation is a common and state-of-the art method for fractionation and separation of macromolecules and particles in a suspension.

 

Metastatic breast cancer in pleural fluid.

Metastatic breast cancer in pleural fluid. euthman/flickr

 

Discussing the research with Controlled Environments magazine, lead researcher Dr. David Lyden explains further: We found that exomeres are the most predominant particle secreted by cancer cells. They are smaller and structurally and functionally distinct from exosomes. Exomeres largely fuse with cells in the bone marrow and liver, where they can alter immune function and metabolism of drugs.”

 

The researcher adds: “The latter finding may explain why many cancer patients are unable to tolerate even small doses of chemotherapy due to toxicity.”

 

Importantly exosomes and exomeres have different biophysical characteristics, like stiffness and electric charge. With this, the findings show, the more rigid the particle, the easier it is likely taken up by cells, rendering exomeres more effective messengers of transferring tumor information to recipient cells.

 

The research further shows how exosomes and exomeres differ in relation to their influence in triggering cancer. Exomeres can carry metabolic enzymes to the liver. Here exomeres are able to cause the liver to “reprogram” its metabolic function and trigger tumor progression.

 

The researchers plan to patent the new technology and develop a diagnostic tool to assist with cancer detection. This will help medics to understand how cancers grow and spread to other organs.

 

The research has been published in the journal Nature Cell Biology. The research paper is titled “Identification of distinct nanoparticles and subsets of extracellular vesicles by asymmetric flow field-flow fractionation.”

 

In related news, Digital Journal has previously reported that researchers have used nanotechnology to improve drug delivery. This is in the form of tailorable nanoscale emulsions which effectively interact with their intended targets (see: “Delivering drugs via nanoscale emulsion.”)

 

Essential Science

 

Demonstrating the need for good cleaning and disinfection using ultraviolet light to show how easy i...

Demonstrating the need for good cleaning and disinfection using ultraviolet light to show how easy it is to miss parts of a surface when cleaning. Tim Sandle

 

This article is part of Digital Journal’s regular Essential Science columns. Each week Tim Sandle explores a topical and important scientific issue. Last week the association between household cleaning chemicals and respiratory problems was examined in light of a new study from the University of Bergen in Norway, which raises concerns about the longer-term health impact.

 

The week before the topic of nanotechnology and the development of a new generation of antimalarial drugs was discussed.

Cornell U: TMD’s Group Working to Devise Next Generation of ‘Super-Thin’ Super-Conductors ~ Possible Platform for Quantum Computing?


TMDs Conell id46369

The experimental realization of ultrathin graphene – which earned two scientists from Cambridge the Nobel Prize in physics in 2010 – has ushered in a new age in materials research.

What started with graphene has evolved to include numerous related single-atom-thick materials, which have unusual properties due to their ultra-thinness. Among them are transition metal dichalcogenides (TMDs), materials that offer several key features not available in graphene and are emerging as next-generation semiconductors.
TMDs could realize topological superconductivity and thus provide a platform for quantum computing – the ultimate goal of a Cornell research group led by Eun-Ah Kim, associate professor of physics.
“Our proposal is very realistic – that’s why it’s exciting,” Kim said of her group’s research. “We have a theoretical strategy to materialize a topological superconductor … and that will be a step toward building a quantum computer. The history of superconductivity over the last 100 years has been led by accidental discoveries. We have a proposal that’s sitting on firm principles.
“Instead of hoping for a new material that has the properties you want,” she said, “let’s go after it with insight and design principle.”
Yi-Ting Hsu, a doctoral student in the Kim Group, is lead author of “Topological superconductivity in monolayer transition metal dichalcogenides,” published April 11 in Nature Communications (“Topological superconductivity in monolayer transition metal dichalcogenides”). Other team members include Kim Group alumni Mark Fischer, now at ETH Zurich in Switzerland, and Abolhassan Vaezi, now at Stanford University.
The group’s proposal: The TMDs’ unusual properties favor two topological superconducting states, which, if experimentally confirmed, will open up possibilities for manipulating topological superconductors at temperatures near absolute zero.
schematic of an interpocket paired state, one of two topological superconducting states
This is a schematic of an interpocket paired state, one of two topological superconducting states proposed in the latest work from the lab of Eun-Ah Kim, associate professor of physics at Cornell University. The material used is a monolayer transition metal dichalcogenide. (Image: Eun-Ah Kim, Cornell University)
Kim identified hole-doped (positive charge-enhanced) single-layer TMDs as a promising candidate for topological superconductivity, based on the known special locking between spin state and kinetic energy of electrons (spin-valley locking) of single-layer TMDs, as well as the recent observations of superconductivity in electron-doped (negative charge-enhanced) single-layer TMDs.
The group’s goal is a superconductor that operates at around 1 degree Kelvin (approximately minus 457 Fahrenheit), that could be cooled with liquid helium sufficiently to maintain quantum computing potential in a superconducting state.
Theoretically, housing a quantum computer powerful enough to justify the power needed to keep the superconductor at 1 degree Kelvin is not out of the question, Kim said. In fact, IBM already has a 7-qubit (quantum bit) computer, which operates at less than 1 Kelvin, available to the public through its IBM Quantum Experience.
A quantum computer with approximately six times more qubits would fundamentally change computing, Kim said.
“If you get to 40 qubits, that computing power will exceed any classical computers out there,” she said. “And to house a 40-qubit [quantum computer] in cryogenic temperature is not that big a deal. It will be a revolution.”
Kim and her group are working with Debdeep Jena and Grace Xing of electrical and computer engineering, and Katja Nowack of physics, through an interdisciplinary research group seed grant from the Cornell Center for Materials Research. Each group brings researchers from different departments together, with support from both the university and the National Science Foundation’s Materials Research Science and Engineering Centers program.
“We’re combining the engineering expertise of DJ and Grace, and expertise Katja has in mesoscopic systems and superconductors,” Kim said. “It requires different expertise to come together to pursue this, and CCMR allows that.”
Source: Cornell University

 

Nanoparticles called C dots show ability to induce cell death in tumors


13-nanoparticleCredit: Cornell University

Nanoparticles known as Cornell dots, or C dots, have shown great promise as a therapeutic tool in the detection and treatment of cancer.

Now, the ultrasmall particles – developed more than a dozen years ago by Ulrich Wiesner, the Spencer T. Olin Professor of Engineering – have shown they can do something even better: kill cancer cells without attaching a cytotoxic drug.

A study led by Michelle Bradbury, director of intraoperative imaging at Memorial Sloan Kettering Cancer Center and associate professor of radiology at Weill Cornell Medicine, and Michael Overholtzer, cell biologist at MSKCC, in collaboration with Wiesner has thrown a surprising twist into the decadelong quest to bring C dots out of the lab and into use as a clinical therapy.

Their paper, “Ultrasmall Nanoparticles Induce Ferroptosis of Nutrient-Deprived Cancer Cells and Suppress Tumor Growth,” was published Sept. 26 in Nature Nanotechnology. The work details how C dots, administered in large doses and with the tumors in a state of nutrient deprivation, trigger a type of cell death called ferroptosis.

“If you had to design a nanoparticle for killing cancer, this would be exactly the way you would do it,” Wiesner said. “The particle is well tolerated in normally healthy tissue, but as soon as you have a tumor, and under very specific conditions, these particles become killers.”

“In fact,” Bradbury said, “this is the first time we have shown that the particle has intrinsic therapeutic properties.”

Wiesner’s fluorescent silica particles, as small as 5 nanometers in diameter, were originally designed to be used as diagnostic tools, attaching to cancer cells and lighting up to show a surgeon where the tumor cells are. Potential uses also included drug delivery and environmental sensing. A first-in-human clinical trial by the Food and Drug Administration, led by Bradbury, deemed the particles safe for humans.

In further testing of the particles over the last five years – including the last 13 months as a member of the Centers of Cancer Nanotechnology Excellence, a National Cancer Institute initiative established in August 2015 – Bradbury, Overholtzer, Wiesner and their collaborators made this major, unexpected finding.

When incubated with cancer cells at high doses – and, importantly, with cancer cells in a state of nutrient deprivation – Wiesner’s peptide-coated C dots show the ability to adsorb iron from the environment and deliver this into cancer cells. The peptide, called alpha-MSH, was developed by Thomas Quinn, professor of biochemistry at the University of Missouri.

This process triggers ferroptosis, a necrotic form of cell death involving plasma membrane rupture – different from the typical cell fragmentation found during a more commonly observed form of called apoptosis.

“The original purpose for studying the dots in cells was to see how well larger concentrations would be tolerated without altering cellular function,” Overholtzer said. “While high concentrations were well-tolerated under normal conditions, we wanted to also know how cancer cells under stress might respond.”

To the group’s surprise, in 24 to 48 hours after the were exposed to the dots, there was a “wave of destruction” throughout the entire cell culture, Wiesner said. Tumors also shrank when mice were administered multiple high dose injections without any adverse reactions, said Bradbury, co-director with Wiesner of the MSKCC-Cornell Center for Translation of Cancer Nanomedicines.

In the ongoing fight against a disease that kills millions worldwide annually – cancer has taken several in Wiesner’s family, making this also a personal crusade for him. Having another weapon can only help, Wiesner said.

“We’ve found another tool that people have not thought about at all so far,” he said. “This has changed our way of thinking about nanoparticles and what they could potentially do.”

Future work will focus on utilizing these particles in combination with other standard therapies for a given tumor type, Bradbury said, with the hope of further enhancing efficacy before testing in humans.

Researchers will also look to tailor the particle to target specific cancers. “It’s a matter of designing the particles with different attachments on them, so they’ll bind to the particular cancer we’re after,” Overholtzer said.

Explore further: Camera system aids cancer clinical trial (w/ Video)

More information: Sung Eun Kim et al. Ultrasmall nanoparticles induce ferroptosis in nutrient-deprived cancer cells and suppress tumour growth,Nature Nanotechnology (2016). DOI: 10.1038/nnano.2016.164

 

 

Cornell University: Quantum Dot Solids for Enhanced Energy Absorption and Light Emission


QDot Solids 022616 quantumdotsoJust as the single-crystal silicon wafer forever changed the nature of communication 60 years ago, a group of Cornell researchers is hoping its work with quantum dot solids – crystals made out of crystals – can help usher in a new era in electronics.

The team, led by Tobias Hanrath, associate professor in the Robert Frederick Smith School of Chemical and Biomolecular Engineering, and graduate student Kevin Whitham, has fashioned two-dimensional superstructures out of single-crystal building blocks. Through a pair of chemical processes, the lead-selenium nanocrystals are synthesized into larger crystals, then fused together to form atomically coherent square superlattices.

The difference between these and previous crystalline structures is the atomic coherence of each 5-nanometer crystal (a nanometer is one-billionth of a meter). They’re not connected by a substance between each crystal – they’re connected to each other. The electrical properties of these superstructures potentially are superior to existing semiconductor nanocrystals, with anticipated applications in energy absorption and light emission.

“As far as level of perfection, in terms of making the building blocks and connecting them into these superstructures, that is probably as far as you can push it,” Hanrath said, referring to the atomic-scale precision of the process.

Watch Video: “Assembling Quantum Dots Into Superlattices”

Associate professor Tobias Hanrath explains his group’s work on assembling quantum dots into ordered, two-dimensional superlattices, the subject of a paper published Feb. 22 in Nature Materials. The work has potential applications in optoelectronics. Credit: Cornell University

QDot Solids 022616 quantumdotso

The Hanrath group’s paper, “Charge transport and localization in atomically coherent quantum dot solids,” is published in this month’s issue of Nature Materials.

This latest work has grown out of previous published research by the Hanrath group, including a 2013 paper published in Nano Letters that reported a new approach to connecting through controlled displacement of a connector molecule, called a ligand. That paper referred to “connecting the dots” – i.e. electronically coupling each quantum dot – as being one of the most persistent hurdles to be overcome.

That barrier seems to have been cleared with this new research. The strong coupling of the nanocrystals leads to formation of energy bands that can be manipulated based on the crystals’ makeup, and could be the first step toward discovering and developing other artificial materials with controllable electronic structure.

Still, Whitham said, more work must be done to bring the group’s work from the lab to society. The structure of the Hanrath group’s superlattice, while superior to ligand-connected nanocrystal solids, still has multiple sources of disorder due to the fact that all nanocrystals are not identical. This creates defects, which limit electron wave function.

“I see this paper as sort of a challenge for other researchers to take this to another level,” Whitham said. “This is as far as we know how to push it now, but if someone were to come up with some technology, some chemistry, to provide another leap forward, this is sort of challenging other people to say, ‘How can we do this better?'”

Hanrath said the discovery can be viewed in one of two ways, depending on whether you see the glass as half empty or half full.

“It’s the equivalent of saying, ‘Now we’ve made a really large single-crystal wafer of silicon, and you can do good things with it,'” he said, referencing the game-changing communications discovery of the 1950s. “That’s the good part, but the potentially bad part of it is, we now have a better understanding that if you wanted to improve on our results, those challenges are going to be really, really difficult.”

Explore further: Nanocrystal infrared LEDs can be made cheaply

More information: Kevin Whitham et al. Charge transport and localization in atomically coherent quantum dot solids, Nature Materials (2016). DOI: 10.1038/nmat4576

 

 

 

Room – Temp Lithium Metal Battery may be close to Reality … and with it “A Cautionary Tale” for the Environment


Lithium Batt Metal 23d9926Rechargeable lithium metal batteries have been known for four decades to offer energy storage capabilities far superior to today’s workhorse lithium-ion technology that powers our smartphones and laptops. But these batteries are not in common use today because, when recharged, they spontaneously grow treelike bumps called dendrites on the surface of the negative electrode.

Over many hours of operation, these dendrites grow to span the space between the negative and positive electrode, causing short-circuiting and a potential safety hazard.

Current technology focuses on managing these dendrites by putting up a mechanically strong barrier, normally a ceramic separator, between the negative and the positive electrodes to restrict the movement of the dendrite. The relative non-conductivity and brittleness of such barriers, however, means the battery must be operated at high temperature and are prone to failure when the barrier cracks.

But a Cornell team, led by chemical and biomolecular engineering professor Lynden Archer and graduate student Snehashis Choudhury, proposed in a recent study that by designing nanostructured membranes with pore dimensions below a critical value, it is possible to stop growth of dendrites in lithium batteries at room temperature.

“The problem with ceramics is that this brute-force solution compromises conductivity,” said Archer, the William C. Hooey Director and James A. Friend Family Distinguished Professor of Engineering and director of the Robert Frederick Smith School of Chemical and Biomolecular Engineering.

“This means that batteries that use ceramics must be operated at very high temperatures — 300 to 400 degrees Celsius [572 to 752 degrees Fahrenheit], in some cases,” Archer said. “And the obvious challenge that brings is, how do I put that in my iPhone?”

You don’t, of course, but with the technology that the Archer group has put forth, creating a highly efficient lithium metal battery for a cellphone or other device could be reality in the not-too-distant future.

Archer credits Choudhury with identifying the polymer polyethylene oxide as particularly promising. The idea was to take advantage of “hairy” nanoparticles, created by grafting polyethylene oxide onto silica to form nanoscale organic hybrid materials (NOHMs), materials Archer and his colleagues have been studying for several years, to create nanoporous membranes.

To screen out dendrites, the nanoparticle-tethered PEO is cross-linked with another polymer, polypropylene oxide, to yield mechanically robust membranes that are easily infiltrated with liquid electrolytes. This produces structures with good conductivity at room temperature while still preventing dendrite growth.

“Instead of a ‘wall’ to block the dendrites’ proliferation, the membranes provided a porous media through which the ions pass, with the pore-gaps being small enough to restrict dendrite penetration,” Choudhury said. “With this nanostructured electrolyte, we have created materials with good mechanical strength and good ionic conductivity at room temperature.”

Archer’s group plotted the performance of its crosslinked nanoparticles against other materials from previously published work and determined “with this membrane design, we are able to suppress dendrite growth more efficiently that anything else in the field. That’s a major accomplishment,” Archer said.

One of the best things about this discovery, Archer said, is that it’s a “drop-in solution,” meaning battery technology wouldn’t have to be radically altered to incorporate it.

“The membrane can be incorporated with batteries in a variety of form factors, since it’s like a paint — and we can paint the surface of electrodes of any shape,” Choudhury added.

This solution also opens the door for other applications, Archer said.

“The structures that Snehashis has created can be as effective with batteries based on other metals, such as sodium and aluminum, that are more earth-abundant and less expensive than lithium and also limited by dendrites,” Archer said.

The group’s paper, “A highly reversible room-temperature lithium metal battery based on crosslinked hairy nanoparticles,” was published Dec. 4 in Nature Communications. All four group members, including doctoral students Rahul Mangal and Akanksha Agrawal, contributed to the paper.

The Archer group’s work was supported by the National Science Foundation’s Division of Materials Research and by a grant from the King Abdullah University of Science and Technology in Saudi Arabia. The research made use of the Cornell High Energy Synchrotron Source, which also is supported by the NSF.


Story Source:

The above post is reprinted from materials provided by Cornell University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Snehashis Choudhury, Rahul Mangal, Akanksha Agrawal, Lynden A. Archer. A highly reversible room-temperature lithium metal battery based on crosslinked hairy nanoparticles. Nature Communications, 2015; 6: 10101 DOI: 10.1038/ncomms10101

 

Lithium Batt Micro Org 160204151102_1_540x360Lithium Battery Catalyst Found to Harm Key Soil Microorganism

University of Wisconsin-Madison

The material at the heart of the lithium ion batteries that power electric vehicles, laptop computers and smartphones has been shown to impair a key soil bacterium, according to new research published online in the journal Chemistry of Materials.

The study by researchers at the University of Wisconsin-Madison and the University of Minnesota is an early signal that the growing use of the new nanoscale materials used in the rechargeable batteries that power portable electronics and electric and hybrid vehicles may have untold environmental consequences.

Researchers led by UW-Madison chemistry Professor Robert J. Hamers explored the effects of the compound nickel manganese cobalt oxide (NMC), an emerging material manufactured in the form of nanoparticles that is being rapidly incorporated into lithium ion battery technology, on the common soil and sediment bacterium Shewanella oneidensis.

Lithium Batt Micro Org 160204151102_1_540x360

Shewanella oneidensis is a ubiquitous, globally distributed soil bacterium. In nature, the microbe thrives on metal ions, converting them to metals like iron that serve as nutrients for other microbes. The bacterium was shown to be harmed by the compound nickel manganese cobalt oxide, which is produced in nanoparticle form and is the material poised to become the dominant material in the lithium ion batteries that will power portable electronics and electric vehicles.
Credit: Illustration by Marushchenko/University of Minnesota

“As far as we know, this is the first study that’s looked at the environmental impact of these materials,” says Hamers, who collaborated with the laboratories of University of Minnesota chemist Christy Haynes and UW-Madison soil scientist Joel Pedersen to perform the new work.

NMC and other mixed metal oxides manufactured at the nanoscale are poised to become the dominant materials used to store energy for portable electronics and electric vehicles. The materials, notes Hamers, are cheap and effective.

“Nickel is dirt cheap. It’s pretty good at energy storage. It is also toxic. So is cobalt,” Hamers says of the components of the metal compound that, when made in the form of nanoparticles, becomes an efficient cathode material in a battery, and one that recharges much more efficiently than a conventional battery due to its nanoscale properties.

Hamers, Haynes and Pedersen tested the effects of NMC on a hardy soil bacterium known for its ability to convert metal ions to nutrients. Ubiquitous in the environment and found worldwide, Shewanella oneidensis, says Haynes, is “particularly relevant for studies of potentially metal-releasing engineered nanomaterials. You can imagine Shewanella both as a toxicity indicator species and as a potential bioremediator.”

Subjected to the particles released by degrading NMC, the bacterium exhibited inhibited growth and respiration. “At the nanoscale, NMC dissolves incongruently,” says Haynes, releasing more nickel and cobalt than manganese. “We want to dig into this further and figure out how these ions impact bacterial gene expression, but that work is still underway.”

Haynes adds that “it is not reasonable to generalize the results from one bacterial strain to an entire ecosystem, but this may be the first ‘red flag’ that leads us to consider this more broadly.”

The group, which conducted the study under the auspices of the National Science Foundation-funded Center for Sustainable Nanotechnology at UW-Madison, also plans to study the effects of NMC on higher organisms.

According to Hamers, the big challenge will be keeping old lithium ion batteries out of landfills, where they will ultimately break down and may release their constituent materials into the environment.

“There is a really good national infrastructure for recycling lead batteries,” he says. “However, as we move toward these cheaper materials there is no longer a strong economic force for recycling. But even if the economic drivers are such that you can use these new engineered materials, the idea is to keep them out of the landfills. There is going to be 75 to 80 pounds of these mixed metal oxides in the cathodes of an electric vehicle.”

Hamers argues that there are ways for industry to minimize the potential environmental effects of useful materials such as coatings, “the M&M strategy,” but the ultimate goal is to design new environmentally benign materials that are just as technologically effective.


Story Source:

The above post is reprinted from materials provided by University of Wisconsin-Madison. The original item was written by Terry Devitt. Note: Materials may be edited for content and length.


Journal Reference:

  1. Mimi N. Hang, Ian L. Gunsolus, Hunter Wayland, Eric S Melby, Arielle C. Mensch, Katie R Hurley, Joel A. Pedersen, Christy L. Haynes, Robert J Hamers. Impact of Nanoscale Lithium Nickel Manganese Cobalt Oxide (NMC) on the Bacterium Shewanella oneidensis MR-1. Chemistry of Materials, 2016; DOI: 10.1021/acs.chemmater.5b04505

 

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Israel is the go-to place for nanotech research


Nano Israeil Conference 2016Cornell University professor Richard Robinson says Jewish State is ‘ahead of the curve’ when it comes to nanotechnology.

One day soon, a start-up somewhere – possibly in Israel – will come up with a system to manufacture precisely-formed nanoparticles that, when joined with other particles, will change the way electronics, clothing, computers and almost everything else can be used.

One day, but not yet, according to Richard Robinson, a visiting scholar at Hebrew University’s Institute of Chemistry. Based at Cornell University, Robinson is in Israel to do research in the area of nanotechnology, where scientists manipulate very tiny atomic particles to create surprising and unique effects that are far different than anything observed in physics until now.

“We know a lot about the principles of nanotechnology now, but there is still a lot to do at the research stage, which is one reason why nanotech hasn’t yet made its presence known to a large extent in the greater society,” Robinson told The Times of Israel. “Nevertheless nanotechnology is already having a major impact in certain applications, like lighting.”

In fact, one of the first commercially successful nano-based products to emerge came from the very Hebrew University lab where Robinson is doing research. Using unique quantum materials, Qlight developed semiconductor nanocrystals that can emit and provide extra brilliance to light, such as enhancing the color of display screens.

Last year the company was acquired by Merck, the German chemical and technology company. Qlight’s technology, said Merck CEO Karl-Ludwig Kley, is “far superior to anything currently on the market, and that will help us retain and expand our position as market leader.”

There will likely be many more such announcements and pronouncements in the future, and many of them are set to be based on technology developed in Israel, said Robinson. “Israel is ahead of the curve on nanotechnology research,” said Robinson.

And there’s plenty more research that needs to be done. “Over the past 20 years or so we have essentially been rewriting the textbooks on physics, because the laws that apply to ‘normal’ particles do not apply to nano-sized particles,” he added.

In other words, certain things happen when five nanometer-sized particles are combined with six nanometer-sized particles. “We’re still observing, categorizing and recording the reactions of these particles sizes with each other and others, in different kinds of materials, and their combinations,” said Robinson.

At home in Cornell, Robinson does a lot of work in materials, controlling their size, shape, composition and surfaces, and assembling the resulting building blocks into functional architectures. Among the applications Robinson’s lab is targeting are new materials for printable electronics and electrocatalysis. His group is also pioneering a new method to probe phonon transport in nanostructures.

On practical example of how nanotech will affect energy is to allow for a much more efficient production method for solar energy. In a solar energy system, the sun’s rays hit photovaltic cells that capture the energy and convert it into direct current (DC) electricity, which is then converted to alternating current (AC), for use in home electric systems or for transfer to the grid. But it turns out that the PV cells being used don’t capture as much of the sun’s rays as they can because of fluctuations in the wavelength of the rays due to time of day or time of year; only about 25% of the rays are captured on average.

PV cells are designed to capture the sun at its strongest in midday, but they can’t capture rays at other times of the day. Using nanomaterials that respond to specific wavelengths PV technology can be much more efficient, tripling the usable “bounty” from the sun, said Robinson.

Eventually, said Robinson, nanotech will live up to the hype that has surrounded it for the past two decades.

“The manufacturing process for nanoparticles is not yet precise. In order for nanotech to be fully commercialized, we need a way to produced nanoparticles on a mass basis with the right size needed for each application,” Robinson said. “We’re not there yet, but it’s on the way – and with all the nanotech research here in Israel, it may just be an Israeli start-up that develops it.”

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Cornell University: Synthetic Immune Organ Produces Antibodies: Application: Immune Therapies and Cancer Research


Synthetic immune 061215 460x250Cornell Univ. engineers have created a functional, synthetic immune organ that produces antibodies and can be controlled in the lab, completely separate from a living organism. The engineered organ has implications for everything from rapid production of immune therapies to new frontiers in cancer or infectious disease research.

The immune organoid was created in the lab of Ankur Singh, assistant professor of mechanical and aerospace engineering, who applies engineering principles to the study and manipulation of the human immune system. The work was published online in Biomaterials and will appear later in print.

The synthetic organ is bio-inspired by secondary immune organs like the lymph node or spleen. It is made from gelatin-based biomaterials reinforced with nanoparticles and seeded with cells, and it mimics the anatomical microenvironment of lymphoid tissue. Like a real organ, the organoid converts B cells—which make antibodies that respond to infectious invaders—into germinal centers, which are clusters of B cells that activate, mature and mutate their antibody genes when the body is under attack. Germinal centers are a sign of infection and are not present in healthy immune organs.

The engineers have demonstrated how they can control this immune response in the organ and tune how quickly the B cells proliferate, get activated and change their antibody types. According to their paper, their 3-D organ outperforms existing 2-D cultures and can produce activated B cells up to 100 times faster.

The immune organ, made of a hydrogel, is a soft, nanocomposite biomaterial. The engineers reinforced the material with silicate nanoparticles to keep the structure from melting at the physiologically relevant temperature of 98.6 degrees.

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When exposed to a foreign agent, such as an immunogenic protein, B cells in lymphoid organs undergo germinal center reactions. The image on the left is an immunized mouse spleen with activated B cells (brown) that produce antibodies. At right, top: a scanning electron micrograph of porous synthetic immune organs that enable rapid proliferation and activation of B cells into antibody-producing cells. At right, bottom: primary B cell viability and distribution is visible 24 hrs following encapsulation procedure. Images: Singh lab

The organ could lead to increased understanding of B cell functions, an area of study that typically relies on animal models to observe how the cells develop and mature.

What’s more, Singh said, the organ could be used to study specific infections and how the body produces antibodies to fight those infections—from Ebola to HIV.

“You can use our system to force the production of immunotherapeutics at much faster rates,” he said. Such a system also could be used to test toxic chemicals and environmental factors that contribute to infections or organ malfunctions.

The process of B cells becoming germinal centers is not well understood, and in fact, when the body makes mistakes in the genetic rearrangement related to this process, blood cancer can result.

“In the long run, we anticipate that the ability to drive immune reaction ex vivo at controllable rates grants us the ability to reproduce immunological events with tunable parameters for better mechanistic understanding of B cell development and generation of B cell tumors, as well as screening and translation of new classes of drugs,” Singh said.

Source: Cornell Univ.

Carbon-Trapping ‘sponges’ can cut Greenhouse Gases


carbon-capture_438x0_scaleDecember 16, 2014 Source: Cornell University
Summary:
In the fight against global warming, carbon capture — chemically trapping carbon dioxide before it releases into the atmosphere — is gaining momentum, but standard methods are plagued by toxicity, corrosiveness and inefficiency. Using a bag of chemistry tricks, materials scientists have invented low-toxicity, highly effective carbon-trapping ‘sponges’ that could lead to increased use of the technology.

A research team led by Emmanuel Giannelis, the Walter R. Read Professor of Engineering in the Department of Materials Science and Engineering, has invented a powder that performs as well or better than industry benchmarks for carbon capture. A paper with their results, co-authored by postdoctoral associates Genggeng Qi and Liling Fu, appeared Dec. 12 in Nature Communications.

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Used in natural gas and coal-burning plants, the most common carbon capture method today is called amine scrubbing, in which post-combustion, carbon dioxide-containing flue gas passes through liquid vats of amino compounds, or amines, which absorb most of the carbon dioxide. The carbon-rich gas is then pumped away — sequestered — or reused. The amine solution is extremely corrosive and requires capital-intensive containment.

The researchers have been working on a better, safer carbon-capture method since about 2008, and they have gone through several iterations. Their latest consists of a silica scaffold, the sorbent support, with nanoscale pores for maximum surface area. They dip the scaffold into liquid amine, which soaks into the support like a sponge and partially hardens. The finished product is a stable, dry white powder that captures carbon dioxide even in the presence of moisture.

Solid amine sorbents are used in carbon capture, Giannelis said, but the supports are usually only physically impregnated with the amines. Over time some of the amine is lost, decreasing effectiveness and increasing cost.

The researchers instead grew their amine onto the sorbent surface, which causes the amine to chemically bond to the sorbents, meaning very little amine loss over time.

Qi said the next steps are to optimize the sorbent and to eventually demonstrate it for industry, possibly at Cornell for retrofitting its power plant. He also said the technology could be used on smaller scale — for example, in greenhouses, where the captured carbon


Story Source:

The above story is based on materials provided by Cornell University. The original article was written by Melissa Osgood. Note: Materials may be edited for content and length.