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Game changer in thermoelectric materials could unlock body-heat powered personal devices

A new University of Wollongong study overcomes a major challenge of thermoelectric materials, which can convert heat into electricity and vice versa, improving conversion efficiency by more than 60%.

Current and potential future applications range from low-maintenance, solid-state refrigeration to compact, zero-carbon power generation, which could include small, personal devices powered by the body’s own heat.

“The decoupling of electronic (electron-based) and thermal (phonon-based) transport will be a game-changer in this industry,” says the UOW’s Prof Xiaolin Wang.

Thermoelectric applications and challenges

Bismuth telluride-based materials (Bi2Te3, Sb2Te3 and their alloys) are the most successful commercially-available thermoelectric materials, with current and future applications falling into two categories: converting electricity into heat, and vice versa:

  • Converting electricity into heat: reliable, low-maintenance solid-state refrigeration (heat pump) with no moving parts, no noise, and no vibration.
  • Converting heat into electricity including fossil-free power generation from a wide range of heat sources or powering micro-devices ‘for free’, using ambient or body temperature.

Heat ‘harvesting’ takes advantage of the free, plentiful heat sources provided by body heat, automobiles, everyday living, and industrial process. Without the need for batteries or a power supply, thermoelectric materials could be used to power intelligent sensors in remote, inaccessible locations.

An ongoing challenge of thermoelectric materials is the balance of electrical and thermal properties: In most cases, an improvement in a material’s electrical properties (higher electrical conductivity) means a worsening of thermal properties (higher thermal conductivity), and vice versa.

“The key is to decouple thermal transport and electrical transport,” says lead author, PhD student Guangsai Yang.

Better efficiency through decoupling

The team added a small amount of amorphous nano-boron particles to bismuth telluride-based thermoelectric materials, using nano-defect engineering and structural design.

Amorphous nano boron particles were introduced using the spark plasma sintering (SPS) method.

“This reduces the thermal conductivity of the material, and at the same time increases its electron transmission,” explains corresponding author Prof Xiaolin Wang.

“The secret of thermoelectric materials engineering is manipulating the phonon and electron transport,” explains Professor Wang.

Because electrons both carry heat and conduct electricity, material engineering based on electron transport alone is prone to the perennial tradeoff between thermal and electrical properties.

Phonons, on the other hand, only carry heat. Therefore, blocking phonon transport reduces thermal conductivity induced by lattice vibrations, without affecting electronic properties.

“The key to improving thermoelectric efficiency is to minimize the heat flow via phonon blocking, and maximize electron flow via (electron transmitting),” says Guangsai Yang. “This is the origin of the record-high thermoelectric efficiency in our materials.”

The result is record-high conversion efficiency of 11.3%, which is 60% better than commercially-available materials prepared by the zone melting method.

As well as being the most successful commercially-available thermoelectric materials, bismuth telluride-based materials are also typical topological insulators.

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Machine learning: A breakthrough in the study of stellar nurseries

The gas clouds in which stars are born and evolve are vast regions of the Universe that are extremely rich in matter, and hence in physical processes. All these processes are intertwined on different size and time scales, making it almost impossible to fully understand such stellar nurseries. However, the scientists in the ORION-B* programme have now shown that statistics and artificial intelligence can help to break down the barriers still standing in the way of astrophysicists.

With the aim of providing the most detailed analysis yet of the Orion molecular cloud, one of the star-forming regions nearest the Earth, the ORION-B team included in its ranks scientists specialising in massive data processing. This enabled them to develop novel methods based on statistical learning and machine learning to study observations of the cloud made at 240,000 frequencies of light**.

Based on artificial intelligence algorithms, these tools make it possible to retrieve new information from a large mass of data such as that used in the ORION-B project. This enabled the scientists to uncover a certain number of ‘laws’ governing the Orion molecular cloud.

For instance, they were able to discover the relationships between the light emitted by certain molecules and information that was previously inaccessible, namely, the quantity of hydrogen and of free electrons in the cloud, which they were able to estimate from their calculations without observing them directly. By analysing all the data available to them, the research team was also able to determine ways of further improving their observations by eliminating a certain amount of unwanted information.

The ORION-B teams now wish to put this theoretical work to the test, by applying the estimates and recommendations obtained and verifying them under real conditions. Another major theoretical challenge will be to extract information about the speed of molecules, and hence visualise the motion of matter in order to see how it moves within the cloud.

Footnotes

*- Standing for Outstanding Radio-Imaging of OrioN B. The scientists involved are from the Laboratoire d’Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères (Observatoire de Paris — PSL/CNRS/Sorbonne Université/Université de Cergy-Pontoise), Institut de Radioastronomie Millimétrique (IRAM), Centre de Recherche en Informatique, Signal et Automatique de Lille (CNRS/Université de Lille/Centrale Lille), Institut de Recherche en Astrophysique et Planétologie (CNRS/Université Toulouse III Paul Sabatier), Institut de Recherche en Informatique de Toulouse (CNRS/Toulouse INP/Université Toulouse III Paul Sabatier), Institut Fresnel (CNRS/Aix-Marseille Université/Centrale Marseille), Laboratoire d’Astrophysique de Bordeaux (CNRS/Université de Bordeaux), du Laboratoire de Physique de l’Ecole Normale Supérieure (CNRS/ENS Paris/Sorbonne Université/Université de Paris), Laboratoire Grenoble Images Parole Signal Automatique (CNRS/Université Grenoble Alpes), Instituto de Física Fundamental (CSIC) (Spain), National Radio Astronomy Observatory (United States), Chalmers University of Technology (Sweden), Cardiff University (United Kingdom), Harvard University (United States), Pontificia Universidad Católica de Chile (Chile).

**- The observations were made using one of IRAM’s radio telescopes, the 30-metre antenna located in Spain’s Sierra Nevada.

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Controlling fully integrated nanodiamonds

Using modern nanotechnology, it is possible nowadays to produce structures which have a feature sizes of just a few nanometres. This world of the most minute particles — also known as quantum systems — makes possible a wide range of technological applications, in fields which include magnetic field sensing, information processing, secure communication or ultra-precise time keeping. The production of these microscopically small structures has progressed so far that they reach dimensions below the wavelength of light. In this way, it is possible to break down hitherto existent boundaries in optics and utilize the quantum properties of light. In other words, nanophotonics represent a novel approach to quantum technologies.

As individual photons move in the quantum regime, scientists describe the relevant light sources as quantum emitters that can be embedded in nanodiamonds, among others. These special diamonds are characterized by their very small particle size, which can range from just a few to several hundred nanometres. Researchers at the University of Münster have now succeeded for the first time in fully integrating nanodiamonds into nanophotonic circuits and at the same time addressing several of these nanodiamonds optically. In the process, green laser light is directed onto colour centres in the nanodiamonds, and the individual red photons generated there are emitted into a network of nano-scale optical components. As a result, the researchers can now control these quantum systems in a fully integrated state. The results have been published in the journal Nano Letters.

Background and methodology

Previously, it was necessary to set up bulky microscopes in order to control such quantum systems. With fabrication technologies similar to those for producing chips for computer processors, light can be directed in a comparable way using waveguides (nanofibres) on a silicon chip. These optical waveguides, measuring less than a micrometre, were produced with the electron-beam lithography and reactive ion etching equipment at the Münster Nanofabrication Facility (MNF). “Here, the size of a typical experimental set-up was shrunk to a few hundred square micrometres,” explains Assistant Professor Carsten Schuck from the Institute of Physics at the University of Münster, who led the study in collaboration with Assistant Professor Doris Reiter from the Institute of Solid State Theory. “This downsizing not only means that we can save space with a view to future applications involving quantum systems in large numbers,” he adds, “but it also enables us, for the first time, to control several such quantum systems simultaneously.” In preliminary work prior to the current study, the Münster scientists developed suitable interfaces between the nanodiamonds and nanophotonic circuits. These interfaces were used in the new experiments, implementing the coupling of quantum emitters with waveguides in an especially effective way. In their experiments, the physicists utilized the so-called Purcell effect, which causes the nanodiamond to emit the individual photons with a higher probability into the waveguide, instead of in some random direction.

The researchers also succeeded in running two magnetic field sensors, based on the integrated nanodiamonds, in parallel on one chip. Previously, this had only been possible individually or successively. To make this possible, the researchers exposed the integrated nanodiamonds to microwaves, thus inducing changes of the quantum (spin) state of the colour centres. The orientation of the spin influences the brightness of the nanodiamonds, which was subsequently read out using the on-chip optical access. The frequency of the microwave field and therewith the observable brightness variations depend on the magnetic field at the location of the nanodiamond. “The high sensitivity to a local magnetic field makes it possible to construct sensors with which individual bacteria and even individual atoms can be detected,” explains Philip Schrinner, lead author of the study.

First of all, the researchers calculated the nanophotonic interface designs using elaborate 3D simulations, thus determining optimal geometries. They then assembled and fabricated these components into a nanophotonic circuit. After the nanodiamonds were integrated and characterized using adapted technology, the team of physicists carried out the quantum mechanical measurements by means of a set-up customized for the purpose.

“Working with diamond-based quantum systems in nanophotonic circuits allows a new kind of accessibility, as we are no longer restricted by microscope set-ups,” says Doris Reiter. “Using the method we have presented, it will be possible in the future to simultaneously monitor and read out a large number of these quantum systems on one chip,” she adds. The researchers’ work creates the conditions for enabling further studies to be carried out in the field of quantum optics — studies in which nanophotonics can be used to change the photo-physical properties of the diamond emitters. In addition to this there are new application possibilities in the field of quantum technologies, which will benefit from the properties of integrated nanodiamonds — in the field of quantum sensing or quantum information processing, for example.

The next steps will include implementing quantum sensors in the field of magnetometry, as used for example in materials analysis for semi-conductor components or brain scans. “To this end,” say Carsten Schuck, “we want to integrate a large number of sensors on one chip which can then all be read out simultaneously, and thus not only register the magnetic field at one place, but also visualize magnetic field gradients in space.”

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Supramolecular chemistry: Self-constructed folded macrocycles with low symmetry

Molecules that are made up of multiple repeating subunits, known as monomers, which may vary or not in their chemical structure, are classified as macromolecules or polymers. Examples exist in nature, including proteins and nucleic acids, which are at the heart of all biological systems. Proteins not only form the basis of structural elements in cells, they also serve as enzymes — which catalyze essentially all of the myriad of chemical transformations that take place in living systems. In contrast, nucleic acids such as DNA and RNA serve as informational macromolecules. DNA stores the cell’s genetic information, which is selectively copied into RNA molecules that provide the blueprints for the synthesis of proteins. In addition, long chains comprised of sugar units provide energy reserves in the form of glycogen, which is stored in the liver and the muscles. These diverse classes of polymeric molecules all have one feature in common: They spontaneously fold into characteristic spatial conformations, for example the famous DNA double helix, which in most cases are essential for their biochemical functions.

Professor Ivan Huc (Department of Pharmacy, LMU) studies aspects of the self-organization processes that enable macromolecules to adopt defined folded shapes. The molecular structures found in nature provide him with models, whose properties he tries to reproduce in the laboratory with non-natural molecules that are neither proteins, nucleic acids or sugar-like. More specifically, he uses the tools of synthetic chemistry to elucidate the underlying principles of self-organization — by constructing molecules that are expressly designed to fold into predetermined shapes. Beginning with monomers that his group has developed, he sets out to produce what he calls ‘foldamers’, by assembling the monomers one by one to generate a folded macromolecule.

Structures with low degrees of symmetry

“The normal way to get the complex structure of proteins is to use different types of monomers, called amino acids,” as Huc reports. “And the normal method to connect different amino acids in the the correct order is to link them one by one.” The sequence of amino acids contains the folding information that allows different protein sequences to fold in different ways.

“But we discovered something unexpected and spectacular,” comments Huc. He and his colleagues in Munich, Groningen, Bordeaux and Berlin used organic, sulfur-containing monomers to spontaneously get cyclic macromolecules with a complex shape, as illustrated by their low degree of symmetry, without requiring a specific sequence. The macromolecules self-synthesize — no further conditions are necessary. “We only put one monomer type in a flask and wait,” Huc says. “This is typical for a polymerization reaction, but polymers from a single monomer usually don´t adopt complex shapes and don’t stop growing at a precise chain length.”

To further control the reaction, the scientists also used either a small guest molecule or a metal ion. The regulator binds within the growing macromolecule and causes monomers to arrange themselves around it. By choosing a regulator with the appropriate characteristics, the authors of the new study were able to produce structures with a predetermined number of subunits. The cyclic macromolecules exhibited low levels of symmetry. Some consisted of either 13, 17 or 23 subunits. Since 13, 17 and 23 are prime numbers, the corresponding folded shapes exhibit low degrees of symmetry.

A model for biological and industrial processes

Interest in the elucidation of such mechanisms is not restricted to the realm of basic research. Huc and his colleagues hope that their approach will lead to the fabrication of designer plastics. Conventional polymers usually consist of mixtures of molecules that vary in length (i.e. the number of monomers they contain). This heterogeneity has an impact on their physical properties. Hence, the ability to synthesize polymer chains of an exact length and/or geometry is expected to lead to materials with novel and interesting behaviors.

Furthermore, foldamers like those that have now been synthesized show close structural resemblances to biopolymers. They therefore offer an ideal model system in which to study the properties of proteins. Every protein is made up of a defined linear (i.e. unbranched) sequence of amino acids, which constitutes its ‘primary structure’. But most amino-acid chains fold into local substructures such as helically coiled stretches, or parallel strands that can form sheets. These units represent the protein’s secondary structure. The term ‘tertiary structure’ is applied to the fully folded single chain. This in turn can interact with other chains to form a functional unit or quaternary structure.

Huc’s ultimate goal is to mimic complex biological mechanisms using structurally defined, synthetic precursors. He wants to understand how, for example, enzymes fold into the correct, biologically active conformation following their synthesis in cells. Molecules whose properties can be precisely controlled in the laboratory provide ideal models with which to work out the answers and perhaps to go beyond enzymes themselves.

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Carbyne: An unusual form of carbon

Which photophysical properties does carbyne have? This was the subject of research carried out by scientists at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), the University of Alberta, Canada, and the Ecole Polytechnique Fédérale de Lausanne in Switzerland, which has led to a greater understanding of the properties of this unusual form of carbon. Their findings have now been published in the latest edition of the journal Nature Communications.

‘Carbon has a very special status in the periodic table of the elements and forms the basis for all forms of life due to the extremely large number of chemical compounds it can form,’ explains Prof. Dr. Dirk M. Guldi at the Chair of Physical Chemistry I at FAU. ‘The most well-known examples are three-dimensional graphite and diamond. However, two-dimensional graphene, one-dimensional nanotubes and zero-dimensional nanodots also open up new opportunities for electronics applications in the future.’

Material with extraordinary properties

Carbyne is a modification of carbon, known as an allotrope. It is manufactured synthetically, comprises one single and very long chain of carbon atoms, and is regarded as a material with extremely interesting electronic and mechanical properties. ‘However, carbon has a high level of reactivity in this form,’ emphasises Prof. Dr. Clémence Corminboef from EPFL. ‘Such long chains are extremely unstable and thus very difficult to characterise.’

Despite this fact, the international research team successfully characterised the chains using a roundabout route. The scientists led by Prof. Dr. Dirk M. Guldi at FAU, Prof. Dr. Clémence Corminboeuf, Prof. Dr. Holger Frauenrath from EPFL and Prof. Dr. Rik R. Tykwinski from the University of Alberta questioned existing assumptions about the photophysical properties of carbyne and gained new insights.

During their research, the team mainly focused on what are known as oligoynes. ‘We can manufacture carbyne chains of specific lengths and protect them from decomposition by adding a type of bumper made of atoms to the ends of the chains. This class of compound has sufficient chemical stability and is known as an oligoyne,’ explains Prof. Dr. Holger Frauenrath from EPFL.

Using the optical band gap

The researchers specifically manufactured two series of oligoynes with varying symmetries and with up to 24 alternating triple and single bonds. Using spectroscopy, they subsequently tracked the deactivation processes of the relevant molecules from excitation with light up to complete relaxation. ‘We were thus able to determine the mechanism behind the entire deactivation process of the oligoynes from an excited state right back to their original initial state and, thanks to the data we gained, we were able to make a prediction about the properties of carbyne,’ concludes Prof. Dr. Rik R. Tykwinski from the University of Alberta.

One important finding was the fact that the so-called optical band gap is actually much smaller than previously assumed. Band gap is a term from the field of semiconductor physics and describes the electrical conductivity of crystals, metals and semiconductors. ‘This is an enormous advantage,’ says Prof. Guldi. ‘The smaller the band gap, the less energy is required to conduct electricity.’ Silicon, for example, which is used in microchips and solar cells, possesses this important property. Carbyne could be used in conjunction with silicon in the future due to its excellent photophysical properties.

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Hackster.io

Neosensory Buzz // Unboxing + Contest!

Our just-launched contest with Neosensory centers on their Buzz wristband, which links haptic feedback to real-world sound – OR any sensors you can devise. (Dare we say transhumanism?) Let’s unbox this beauty and take an in-depth look!

// https://www.hackster.io/contests/neoedge
// https://neosensory.com/
// https://neosensory.com/blog/neosensory-arduino-sdk/
// https://www.hackster.io/mike-perrotta/temperature-sensing-wristband-with-the-neosensory-buzz-741385

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Researchers simulate privacy leaks in functional genomics studies

The functional genomics field, which looks at the activities of the genome and levels of gene expression rather than particular gene mutations, generally relies on aggregating information from many samples for its statistical power. This means that broadly sharing raw data is vital; however, sharing these data currently is challenging because of the privacy concerns of individuals within those datasets, leading to these data being largely inaccessible behind firewalls.

In a study publishing November 12 in the journal Cell, a team of investigators demonstrates that it’s possible to de-identify those data to ensure patient privacy. They also demonstrate how these raw data could be linked back to specific individuals through their gene variants by something as simple as an abandoned coffee cup if these sanitation measures are not put in place.

“The purpose of this study is to come up with practical ways to broadly share the raw data without creating undue privacy concerns,” says senior author Mark Gerstein, a professor of bioinformatics at Yale University.

Functional genomics research is frequently tied to a specific disease. For example, an investigation into a particular psychiatric condition might look at the expression of certain genes in a type of neuron. And, by nature of having their genetic material included in such a study, an individual’s medical status with regard to that condition could inadvertently be revealed.

This can happen through what’s known as a quasi-identifier. The way a quasi-identifier works is that if someone has enough individual data points about you, even if those data on their own are not sensitive or unique, they can be combined to create an identifier that is unique to you. In a non-genetic setting, this means if someone has your zip code, birthday, the model of car you drive, and other similar data that might not be considered private or sensitive on their own, they might eventually be able to combine them and create a unique profile that would link you to other data that you wouldn’t want public — data like financial records that were collected when you applied for a car loan. The same thing could happen if someone were able to obtain some of your genetic variants and link those variants to the presence of your genetic material in a study on a particular disease. This could in turn reveal a diagnosis, such as HIV status or an inherited cancer predisposition, that you would prefer to keep private.

In their study, the researchers constructed a “linkage attack” scenario to demonstrate how someone could make these kinds of connections from functional genomics studies’ data by using DNA obtained from a discarded coffee cup. After adding samples from two consenting participants to a functional genomics database, the researchers gathered used coffee cups from the same individuals. They sequenced genetic material left on the cups and were able to successfully match that material to the samples in the database and infer sensitive health information about the participants. The researchers were also able to use DNA information “stolen” from a genotyping database to match the identities of 421 people with phenotypic information found in a test functional-genomics dataset that the researchers constructed for 436 people.

However, the researchers also identified steps that can be taken to thwart these kinds of linkage attacks and safeguard participants’ health information when functional genomics datasets are shared. “Functional genomics is special because variants are usually not needed for data processing,” says first author Gamze Gürsoy, a postdoctoral researcher at the Gerstein lab. “Because of this, we can sanitize the variants to prevent data being linked back to the private information connected to the phenotypes included in these studies, while still retaining the utility of the data.”

To achieve this balance between privacy and data usefulness, the researchers propose a file-format manipulation that will allow raw functional genomics data to be shared while largely reducing sensitive information leakage by generalizing information about phenotypic variants. The file format is based on a widely used standard file-format system, is compatible with a range of software and pipelines, and when tested, showed little loss of utility. The researchers have also developed a framework with which other researchers can tune the level of privacy and utility balance they want to achieve with the file format based on the policies and consents of the donors.

“As more data are released for these kinds of functional genomics studies, concerns about security and privacy shouldn’t be lost,” Gerstein says. “At the dawn of the Internet, people didn’t realize how important their online activities would become. Now that type of digital privacy has become so important to us. If we move into an era where getting your genome sequenced becomes routine, we don’t want these worries about health privacy to become dominating.”

This work was supported by the National Institutes of Health, the AL Williams Professorship fund, and the Chan Zuckerberg Initiative Donor-Advised Fund.

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New virtual reality software allows scientists to ‘walk’ inside cells

Virtual reality software which allows researchers to ‘walk’ inside and analyse individual cells could be used to understand fundamental problems in biology and develop new treatments for disease.

The software, called vLUME, was created by scientists at the University of Cambridge and 3D image analysis software company Lume VR Ltd. It allows super-resolution microscopy data to be visualised and analysed in virtual reality, and can be used to study everything from individual proteins to entire cells. Details are published in the journal Nature Methods.

Super-resolution microscopy, which was awarded the Nobel Prize for Chemistry in 2014, makes it possible to obtain images at the nanoscale by using clever tricks of physics to get around the limits imposed by light diffraction. This has allowed researchers to observe molecular processes as they happen. However, a problem has been the lack of ways to visualise and analyse this data in three dimensions.

“Biology occurs in 3D, but up until now it has been difficult to interact with the data on a 2D computer screen in an intuitive and immersive way,” said Dr Steven F. Lee from Cambridge’s Department of Chemistry, who led the research. “It wasn’t until we started seeing our data in virtual reality that everything clicked into place.”

The vLUME project started when Lee and his group met with the Lume VR founders at a public engagement event at the Science Museum in London. While Lee’s group had expertise in super-resolution microscopy, the team from Lume specialised in spatial computing and data analysis, and together they were able to develop vLUME into a powerful new tool for exploring complex datasets in virtual reality.

“vLUME is revolutionary imaging software that brings humans into the nanoscale,” said Alexandre Kitching, CEO of Lume. “It allows scientists to visualise, question and interact with 3D biological data, in real time all within a virtual reality environment, to find answers to biological questions faster. It’s a new tool for new discoveries.”

Viewing data in this way can stimulate new initiatives and ideas. For example, Anoushka Handa — a PhD student from Lee’s group — used the software to image an immune cell taken from her own blood, and then stood inside her own cell in virtual reality. “It’s incredible — it gives you an entirely different perspective on your work,” she said.

The software allows multiple datasets with millions of data points to be loaded in and finds patterns in the complex data using in-built clustering algorithms. These findings can then be shared with collaborators worldwide using image and video features in the software.

“Data generated from super-resolution microscopy is extremely complex,” said Kitching. “For scientists, running analysis on this data can be very time consuming. With vLUME, we have managed to vastly reduce that wait time allowing for more rapid testing and analysis.”

The team are mostly using vLUME with biological datasets, such as neurons, immune cells or cancer cells. For example, Lee’s group has been studying how antigen cells trigger an immune response in the body. “Through segmenting and viewing the data in vLUME, we’ve quickly been able to rule out certain hypotheses and propose new ones,” said Lee. This software allows researchers to explore, analyse, segment and share their data in new ways. All you need is a VR headset.”

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Light stimulation makes bones heavier

Osteoporosis is a disease in which bone loses mass as a result of age or other influences. This weakening is the leading cause of fractures in the elderly, often after trivial injuries, and makes treating these “pathological fractures” a challenge. Bone health is a dynamic process of continual remodeling controlled by multiple factors. Sclerostin, a glycoprotein coded by the gene SOST, is produced by bone cells and suppresses bone formation. Now, researchers at Tokyo Medical and Dental University (TMDU) have shown that laser irradiation, by inhibiting sclerostin expression without inducing inflammation, shows promise as a new treatment modality for osteoporosis.

Lasers have been used in medical and dental practice for their beneficial photo-biomodulation effects on tissue healing. The benefits of low-level laser therapy are now gaining increased attention in spheres of medicine and dentistry that require enhanced bone regeneration.

The team knew that in periodontal surgery, bone that underwent controlled destruction using a specific type of laser known as an Er:YAG laser healed faster than bone subjected to conventional bur drilling. Thus, they wondered whether Er:YAG laser irradiation modified SOST expression in bone. “We set out to compare comprehensive and sequential gene expression and biological healing responses in laser-ablated, bur-drilled, and untreated bone, as well as investigating the bio-stimulation effect of an Er:YAG laser on osteogenic cells,” explains Yujin Ohsugi, lead author.

Using microarray analysis, the researchers first studied gene expression patterns in rat skull bones during healing at 6, 24, and 72 hours after drilling or laser treatment. Immunohistochemical analysis at 1 day was performed to detect sclerostin expression. Additionally, oseteogenic cell cultures were irradiated in vitro and assessed for cell death and sclerostin concentration.

“We confirmed decreased sclerostin expression after laser irradiation both in vivo and in vitro,” affirms Sayaka Katagiri, corresponding author. “Interestingly, sequential microarray analysis revealed a clear distinction in the gene expression pattern between bur-drilled and laser-ablated bones at 24 hours, with the former alone showing enriched inflammation-related pathways. Significantly, at 6 hours following laser ablation, the Hippo signaling pathway that limits tissue overgrowth was enriched but inflammation-related pathways remained unaffected, suggesting that laser irradiation worked thorough mechanical bio-stimulation.”

The finding that mechanical stimulation of laser irradiation inhibits the pathways that suppress bone regeneration without provoking inflammation may aid development of laser-based therapeutic methods. Such methods might be used in treatments for osteoporosis and to induce or promote bone regeneration in medical and dental procedures.

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Cloudflare Launches API Shield to Combat Increased Rate of API Attacks

Cloudflare has announced the release of Cloudflare API Shield. This new product, which is free to all account holders regardless of their pricing plan, is intended to simplify API security via mutual TLS authentication, API schema validation, and a positive security model.

Cloudflare noted research by Gartner which projects that by 2022 API abuses will become the most frequent attack vector that results in enterprise web application breaches. In light of this, the company has decided to release Cloudflare API Shield, a new API security product that implements a positive security model that Cloudflare hopes will reduce API vulnerabilities.

This security model is one that begins with a block everything mindset and then builds outward allowing known behaviors and identities while rejecting everything else. The company believes that this strategy, in contrast with a negative model that by default allows everything except known problematic requests, is especially powerful for APIs given the myriad ways that this technology can be threatened. 

At launch, Cloudflare is highlighting two major features crucial to implementing this security model. The first is deploying strong authentication via mutual TLS authentication. This is intended to remove the possibility of password sharing and reuse. Beyond this API Shield will rely upon API schema validation to establish the sort of known behaviors that positive security is powered by. This would mean that strict API schema validation is implemented to ensure that requests fall in line with very specific standards. This sort of validation is in beta for JSON right now, with Cloudflare promising support for gRPC in the near future.

The product roadmap goes beyond gRPC support with Cloudflare working toward a web application firewall, rate limiting, and DDoS protection specifically designed for non-HTML traffic.

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