Research shows how to improve the bond between implants and bone

Research carried out recently at the Canadian Light Source (CLS) in Saskatoon has revealed promising information about how to build a better dental implant, one that integrates more readily with bone to reduce the risk of failure.

“There are millions of dental and orthopedic implants placed every year in North America and a certain number of them always fail, even in healthy people with healthy bone,” said Kathryn Grandfield, assistant professor in the Department of Materials Science and Engineering at McMaster University in Hamilton.

A dental implant restores function after a tooth is lost or removed. It is usually a screw shaped implant that is placed in the jaw bone and acts as the tooth roots, while an artificial tooth is placed on top. The implant portion is the artificial root that holds an artificial tooth in place.

Grandfield led a study that showed altering the surface of a titanium implant improved its connection to the surrounding bone. It is a finding that may well be applicable to other kinds of metal implants, including engineered knees and hips, and even plates used to secure bone fractures.

About three million people in North America receive dental implants annually. While the failure rate is only one to two percent, “one or two percent of three million is a lot,” she said. Orthopedic implants fail up to five per cent of the time within the first 10 years; the expected life of these devices is about 20 to 25 years, she added.

“What we’re trying to discover is why they fail, and why the implants that are successful work. Our goal is to understand the bone-implant interface in order to improve the design of implants.”

>Read more on the Canadian Light Source website

Synchrotron researchers uncover lost images from the 19th century

Art curators will be able to recover images on daguerreotypes, the earliest form of photography that used silver plates, after scientists learned how to use light to see through degradation that has occurred over time.

Research published today in Scientific Reports includes two images from the National Gallery of Canada’s photography research unit that show photographs that were taken, perhaps as early as 1850, but were no longer visible because of tarnish and other damage. The retrieved images, one of a woman and the other of a man, were beyond recognition. “It’s somewhat haunting because they are anonymous and yet it is striking at the same time,” said Madalena Kozachuk, a PhD student in the Department of Chemistry at Western University and lead author of the scientific paper.

“The image is totally unexpected because you don’t see it on the plate at all. It’s hidden behind time. But then we see it and we can see such fine details: the eyes, the folds of the clothing, the detailed embroidered patterns of the table cloth.”
The identities of the woman and the man are not known. It’s possible that the plates were produced in the United States, but they could be from Europe.
For the past three years, Kozachuk and an interdisciplinary team of scientists have been exploring how to use synchrotron technology to learn more about chemical changes that damage daguerreotypes.

>Read more on the Canadian Light Source (CLS) website

Image: A mounted daguerreotype resting on the outside of the vacuum chamber within the SXRMB (a beamline at CLS) hutch.
Credit: Madalena Kozachuk.

Berkeley Lab researchers receive DOE Early Career Research Awards

Six scientists at Lawrence Berkeley National Laboratory (Berkeley Lab) have been selected by the U.S. Department of Energy’s (DOE’s) Office of Science to receive significant funding for research through its Early Career Research Program.

The program, now in its ninth year, is designed to bolster the nation’s scientific workforce by providing support to exceptional researchers during the crucial early career years, when many scientists do their most formative work. The six Berkeley Lab recipients are among a total of 84 recipients selected this year, including 30 from DOE’s national laboratories. This year’s awards bring to 35 the total number of Berkeley Lab scientists who have received Early Career Research Program awards since 2010.

“We are grateful that DOE has chosen to recognize these six young Berkeley Lab scientists,” said Berkeley Lab Director Mike Witherell. “Our Lab takes very seriously the responsibility to train the next generation of scientists and engineers. Each of their proposed projects not only represents cutting-edge science but will also contribute to our understanding of the world and a sustainable future.“

The scientists are each expected to receive grants of up to $2.5 million over five years to cover year-round salary plus research expenses.

>Read more on the Advanced Light Source website

Image: Ethan Crumlin is a staff scientist at the Advanced Light Source (ALS), a DOE Office of Science User Facility at Berkeley Lab, who specializes in studies of chemistry at the interfaces between solids, liquids, and gases.

Molecular Anvils Trigger Chemical Reactions

Takeuchi Receives European Inventor Award 2018

Prolific patent-holder won for inventing battery that increases the lifespan of implantable defibrillators fivefold, greatly reducing need for reoccurring surgery.

Esther Sans Takeuchi, PhD, has won the 2018 European Inventor Award in the “Non-EPO countries”, the European Patent Office (EPO) announced today. The award was given to her by the EPO at a ceremony held today in Paris, Saint-Germain-en-Laye. Of the four U.S. scientists nominated for the award, Takeuchi is the only American to bring home Europe’s most prestigious prize of innovation.

Takeuchi is the Chief Scientist of the Energy Sciences Directorate at the U.S. Department of Energy’s Brookhaven National Laboratory, Stony Brook University’s (SBU) William and Jane Knapp Endowed Chair in Energy and the Environment, and a Distinguished Professor of Chemistry in the College of Arts & Sciences and in Materials Science and Chemical Engineering in the College of Engineering and Applied Sciences at SBU. She was honored for developing the compact batteries that power tiny, implantable cardiac defibrillators (ICDs)—devices that detect and correct irregular, potentially fatal, heart rhythms. Her lithium silver vanadium oxide (“Li/SVO”) battery extended the power-source lifetime for ICDs to around five years, considerably longer than its predecessors, thus reducing the number of surgeries patients needed to undergo to replace them. Her invention led not only to an advance in battery chemistry, but also enabled the production and widespread adoption of ICDs and significantly improved patient well-being.

>Read more on the National Synchrotron Light Source II (NSLS-II) website

Image: Esther Sans Takeuchi, a joint appointee of Brookhaven National Laboratory and Stony Brook University, has won the 2018 European Inventor Award in the category “Non-EPO countries.”



Perovskites, the rising star for energy harvesting

Perovskites are promising candidates for photovoltaic cells, having reached an energy harvesting of more than 20% while it took silicon three decades to reach an equivalent. Scientists from all over the world are exploring these materials at the ESRF.

Photovoltaic (PV) panels exist in our society since several years now. The photovoltaic market is currently dominated by wafer-based photovoltaics or first generation PVs, namely the traditional crystalline silicon cells, which take a 90% of the market share.

Although silicon (Si) is an abundant material and the price of Si-PV has dropped in the past years, their manufacturing require costly facilities. In addition, their fabrication typically takes place in countries that rely on carbon-intensive forms of electricity generation (high carbon footprint).

But there is room for hope. There is a third generation of PV: those based on thin-film cells. These absorb light more efficiently and they currently take 10% of the market share.

>Read more on the European Synchrotron website

Image: The CEA-CNRS team on ID01. From left to right: Peter Reiss, from CEA-Grenoble/INAC, Tobias Schulli from ID01, Tao Zhou from ID01, Asma Aicha Medjahed, Stephanie Pouget (both from CEA-Grenoble/INAC) and David Djurado, from the CNRS. 
Credits: C. Argoud.

Putting CO2 to a good use

One of the biggest culprits of climate change is an overabundance of carbon dioxide in the atmosphere.

As the world tries to find solutions to reverse the problem, scientists from Swansea University have found a way of using CO2 to create ethylene, a key chemical precursor. They have used ID03 to test their hypotheses.

Carbon dioxide is essential for the survival of animals and plants. However, people are the biggest producers of CO2 emissions. The extensive use of fossil fuels such as coal, oil, or natural gas has created an excess of CO2 in the atmosphere, leading to global warming. Considerable research focuses on capturing and storing harmful carbon dioxide emissions. But an alternative to expensive long-term storage is to use the captured CO2 as a resource to make useful materials.

>Read more on the European Synchrotron wesbite

Scientists explore how slow release fertilizer behaves in soil

Testing soil samples at the Canadian Light Source has helped a University of Saskatchewan soil scientist understand how tripolyphosphate (TPP), a slow release form of phosphorus fertilizer, works in the soil as a plant nutrient for much longer periods than previously thought.

Jordan Hamilton says the research also has implications for ongoing efforts by U of S soil scientists to use phosphorous-rich materials to clean up contaminated petroleum sites.

Hamilton, now a post-doctoral fellow working within U of S professor Derek Peak’s Environmental Soil Chemistry group, had a chapter of his PhD thesis, “Chemical speciation and fate of tripolyphosphate after application to a calcareous soil,” published earlier this year in the online journal Geochemical Transactions.

TPP needs to break down into a simpler form of phosphate in order to be used as a nutrient by plants. In most types of soil, the belief was that TPP would break down right away, says Hamilton.

“I would definitely say the biggest surprise is how quickly the TPP adsorbed (attached itself) to mineral sources, especially in these calcium-rich soils,” he said. “For the longer term, it was surprising to see it persist.”

>Read more on the Canadian Light Source website


Tailoring the surface chemical reactivity of transition‐metal dichalcogenide PtTe2 crystals

Recently, the PtX2 (X=S, Se, Te) class of transition-metal dichalcogenides has emerged as one of the most promising among layered materials “beyond graphene” for the presence of high room-temperature electron mobility and, moreover, bulk type-II Dirac fermions, arising from a tilted Dirac cone.
Information on the ambient stability of PtTe2 is a crucial step in order to evaluate the feasibility of its exploitation in technology. Moreover, the possibility to tune surface chemical reactivity by appropriate surface modification is an essential step for its employment for diverse applications, especially in catalysis.
By means of experiments with several surface-science spectroscopies and density functional theory, an international team of researchers from Italy, Republic of Korea, and Taiwan (coordinated by Graphene Labs of Istituto Italiano di Tecnologia) has investigated the reactivity of the PtTe2 surface toward most common ambient gases (oxygen and water), under the framework of the European Graphene Flagship-Core1 project.
To assess the surface chemical reactivity of PtTe2, X-ray photoelectron spectroscopy (XPS) carried out at the APE-HE beamline has been combined with high-resolution electron energy loss (HREELS) experiments and with density functional theory.
From the analysis of Te 3d core-level spectra in XPS and from the featureless vibrational spectrum in HREELS, it has been demonstrated that as-cleaved defect-free PtTe2 surface is inert toward most common ambient gases (oxygen and water).
In the evaluation of the ambient stability of PtTe2, the possible influence of Te vacancies on surface chemical reactivity deserves particular attention. As a matter of fact, Te vacancies may appear on non-stoichiometric samples during the growth process. To check the influence of Te vacancies on ambient stability of PtTe2, Te vacancies have been intentionally introduced in stoichiometric PtTe2 samples by Ar-ion sputtering. After exposing to O2 the PtTe2 surface defected by ion sputtering, with a Pt:Te ratio of 39:61, spectral features related to Te(IV) species appear, arising from the formation of Te=O bonds in a tellurium-oxide phase. The Te(IV) components are the most intense lines in the Te 3d XPS spectra for the case of air-exposed defected samples (see Figure 1). Concerning reactivity to water, it adsorbs molecularly even at room temperature on defected PtTe2. These findings also imply that the presence of Te vacancies is able to jeopardize the ambient stability of uncapped PtTe2-based devices, with a subsequent necessity to reduce the amount of Te vacancies for a successful technological exploitation of PtTe2.

>Read more on the Elettra website

Figure: XPS spectra of Te-3d core levels acquired for: defected PtTe2 (green curve), the same surface exposed to 106 L of O2 (black curve) and air-exposed defected PtTe2 (yellow curve). The photon energy is 745 eV. 

COSMIC impact: next-gen X-ray microscopy platform now operational

A next-generation X-ray beamline now operating at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) brings together a unique set of capabilities to measure the properties of materials at the nanoscale.

Called COSMIC, for Coherent Scattering and Microscopy, this X-ray beamline at Berkeley Lab’s Berkeley Lab’s Advanced Light Source (ALS) allows scientists to probe working batteries and other active chemical reactions, and to reveal new details about magnetism and correlated electronic materials.
COSMIC has two branches that focus on different types of X-ray experiments: one for X-ray imaging experiments and one for scattering experiments. In both cases, X-rays interact with a sample and are measured in a way that provides, structural, chemical, electronic, or magnetic information about samples.

The beamline is also intended as an important technological bridge toward the planned ALS upgrade, dubbed ALS-U, that would maximize its capabilities.

>Read more on the Advanced Light Source website

Image: X-rays strike a scintillator material at the COSMIC beamline, causing it to glow.
Credit: Simon Morton/Berkeley Lab

Determining the impact of post-conservation corrosion

When King Henry VIII’s flagship, the Mary Rose, sank off Portsmouth in 1545, it took with it 1248 iron cannonballs. Since the excavation of the shipwreck (from 1979-1983), the cannonballs have been conserved in different ways, offering a unique opportunity to study different conservation methods.

Humans have been using iron to make weapons, tools and ceremonial items for more than 20,000 years, but once these objects have been excavated they are at risk from corrosion, which can be accelerated in the presence of chlorine. Each recovered artefact has to be conserved to prevent it from deteriorating in the presence of air and water. Until now, a comparison of the effectiveness of different conservation methods has been hampered by the variable nature of both the artefacts found, and the environment in which they were buried.

>Read more on the Diamond Light Source website

Image: Dr Eleanor Schofield, Dr Giannantonio Cibin and Hayley Simon with iron shot and samples on Diamond’s B18 beamline.
Credit: Diamond Light Source

Possible Path to the Formation of Life’s Building Blocks in Space

Experiments at Berkeley Lab’s Advanced Light Source reveal how a hydrocarbon called pyrene could form near stars

Scientists have used lab experiments to retrace the chemical steps leading to the creation of complex hydrocarbons in space, showing pathways to forming 2-D carbon-based nanostructures in a mix of heated gases.

The latest study, which featured experiments at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), could help explain the presence of pyrene, which is a chemical compound known as a polycyclic aromatic hydrocarbon, and similar compounds in some meteorites.

A team of scientists, including researchers from Berkeley Lab and UC Berkeley, participated in the study, published March 5 in the Nature Astronomy journal. The study was led by scientists at the University of Hawaii at Manoa and also involved theoretical chemists at Florida International University.

>Read more on the Advanced Light Source website

Image: A researcher handles a fragment and a test tube sample of the Murchison meteorite, which has been shown to contain a a variety of hydrocarbons and amino acids, in this photo from a previous, unrelated study at Argonne National Laboratory. Experiments at Berkeley Lab are helping to retrace the chemical steps by which complex hydrocarbons like pyrene could form in the Murchison meteorite and other meteorites.
Credit: Argonne National Laboratory

Converting CO2 into usable energy

Scientists show that single nickel atoms are an efficient, cost-effective catalyst for converting carbon dioxide into useful chemicals.

Imagine if carbon dioxide (CO2) could easily be converted into usable energy. Every time you breathe or drive a motor vehicle, you would produce a key ingredient for generating fuels. Like photosynthesis in plants, we could turn CO2 into molecules that are essential for day-to-day life. Now, scientists are one step closer.

Researchers at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory are part of a scientific collaboration that has identified a new electrocatalyst that efficiently converts CO2 to carbon monoxide (CO), a highly energetic molecule. Their findings were published on Feb. 1 in Energy & Environmental Science.

“There are many ways to use CO,” said Eli Stavitski, a scientist at Brookhaven and an author on the paper. “You can react it with water to produce energy-rich hydrogen gas, or with hydrogen to produce useful chemicals, such as hydrocarbons or alcohols. If there were a sustainable, cost-efficient route to transform CO2 to CO, it would benefit society greatly.”

>Read more on the NSLS-II website

Image: Brookhaven scientists are pictured at NSLS-II beamline 8-ID, where they used ultra-bright x-ray light to “see” the chemical complexity of a new catalytic material. Pictured from left to right are Klaus Attenkofer, Dong Su, Sooyeon Hwang, and Eli Stavitski.


Scientists confirm speculation on the chemistry of a high-performance battery

X-ray experiments at Berkeley Lab reveal what’s at work in an unconventional electrode.

Scientists have discovered a novel chemical state of the element manganese. This chemical state, first proposed about 90 years ago, enables a high-performance, low-cost sodium-ion battery that could quickly and efficiently store and distribute energy produced by solar panels and wind turbines across the electrical grid.

This direct proof of a previously unconfirmed charge state in a manganese-containing battery component could inspire new avenues of exploration for battery innovations.

X-ray experiments at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) were key in the discovery. The study results were published Feb. 28 in the journal Nature Communications.

Scientists at Berkeley Lab and New York University participated in the study, which was led by researchers at Natron Energy, formerly Alveo Energy, a Santa Clara, California-based battery technology company.

The battery that Natron Energy supplied for the study features an unconventional design for an anode, which is one of its two electrodes. Compared with the relatively mature designs of anodes used in lithium-ion batteries, anodes for sodium-ion batteries remain an active focus of R&D.

>Read more on the Advanced Light Source website

Photo: An array of solar panels and windmills.
Credit: PxHere

Unraveling the Complexities of Auto-Oxidation

A comparison of the etch mechanisms of germanium and silicon

Time multiplexed, deep reactive ion etching (DRIE) is a standard silicon microfabrication technique for fabricating MEMS sensors, actuators, and more recently in CMOS development for 2.5D and 3D memory devices.

At CHESS, we have adopted this microfabrication technique to develop novel x-ray optics called,Collimating Channel Arrays  (CCAs) [1], for confocal x-ray fluorescence microscopy (CXRF). Because the first CCA optics were fabricated from silicon substrates, the range of x-ray fluorescence energies for which they could be used, and hence the elements they could be used to study, was limited. Unwanted x-rays above about 11 keV could penetrate through the silicon, showing up as background and interfering with the measurement.

To solve the background problem, germanium substrates were used to fabricate the CCA optics. Germanium, which is much denser and therefore x-ray opaque than silicon, is also etch compatible with the fluorine etch chemistry for silicon DRIE. However, small differences in etch behavior between germanium and silicon can cause big differences in the outcome. Here, Genova et al JVST B [2] report a systematic comparison of  the etch mechanisms of silicon and germanium, performed with the Plasma Therm Versaline deep silicon etcher at the Cornell NanoScale Science & Technology Facility (CNF). The etch rates of silicon and germanium were compared by varying critical parameters in the DRIE process, especially the applied power and voltage used for each of 3 steps in the etch process,  on custom-designed wafers with a variety of features with systematically varying dimensions.

>Read more on the CHESS website

Image: (extract, full image here) SEM of high aspect ratio (>13:1) etched features in Si at 3.7 μm/min (a) and Ge at 3.4 μm/min (b)