Exploring the Surface Properties of NiO with Low-Energy Electron Diffraction

Antiferromagnetic (AF) crystals like NiO are experiencing a renaissance as promising materials for ultrafast spintronics. To re-establish old experimental results of surface property investigations and present new theoretical analysis, researchers from Sophia University carried out low-energy electron diffraction (LEED) analysis of AF crystal NiO. They reported an I-V spectra of ‘half-order beam’ and observed a surface wave resonance effect, providing useful insights into energy-temperature dependence of LEED and coherent spin exchange scattering in NiO.

Spintronics is a field that deals with electronics that exploit the intrinsic spin of electrons and their associated magnetic moment for applications such as quantum computing and memory storage devices. Owing to its spin and magnetism exhibited in its insulator-metal phase transition, the strongly correlated electron systems of nickel oxide (NiO) have been thoroughly explored for over eight decades. Interest in its unique antiferromagnetic (AF) and spin properties has seen a revival lately, since NiO is a potential material for ultrafast spintronics devices.

Despite this rise in popularity, exploration of its surface magnetic properties using low-energy electron diffraction (LEED) technique has not received much attention since the 1970s. To review the understanding of the surface properties, Professor Masamitsu Hoshino and Emeritus Professor Hiroshi Tanaka, both from the Department of Materials and Life Sciences at Sophia University, Japan, revisited the surface LEED crystallography of NiO. The results of their quantitative experimental study investigating the coherent exchange scattering in Ni2+ ions in AF single crystal NiO were reported in The European Physical Journal D.

Improving Wood Products Could Be a Key to Reducing Greenhouse Gas Emissions

Corrugated cardboard boxes are one of the most important products made from loblolly pine
Photo Credit: Aleksandar Pasaric

Harnessing the ability of wood products to store carbon even after harvest could have a significant effect on greenhouse gas emissions and change commonly accepted forestry practices, a new study from NC State researchers suggests.

The new study published in the journal Carbon Balance and Management uses carbon storage modeling to link the carbon stored in wood products with the specific forest system from which the products originated. Wood products and the forests they come from store different amounts of carbon, and being able to compare the two more specifically would help forest managers better understand these tradeoffs and plan for better carbon storage.

By tracing carbon in southern loblolly pine plantations from planting to harvest, the study also identified specific wood products that are important to improving carbon storage and reducing greenhouse gas emissions. Chief among them were corrugated carboard boxes.

“Corrugated cardboard boxes are one of the most important products made from loblolly pine,” said Sarah Puls, NC State graduate assistant and corresponding author of the study. “If we can extend the effective lifetime of products like these boxes, it could have a significant impact on the carbon storage associated with southern loblolly pine plantations.”

How surface roughness influences the adhesion of soft materials

The illustration shows the contact area of a soft solid that is separated from a rough surface. Each colored spot corresponds to an instability of the contact. The different color intensity shows how much energy is lost in the process.
Illustration Credit: Antoine Sanner, Lars Pastewka.

Adhesive tape or sticky notes are easy to attach to a surface, but are difficult to remove. This phenomenon, known as adhesion hysteresis, can be fundamentally observed in soft, elastic materials: Adhesive contact is formed more easily than it is broken. Researchers at the University of Freiburg, the University of Pittsburgh and the University of Akron in the US have now discovered that this adhesion hysteresis is caused by the surface roughness of the adherent soft materials. Through a combination of experimental observations and simulations, the team demonstrated that roughness interferes with the separation process, causing the materials to detach in minute, abrupt movements, which release parts of the adhesive bond incrementally. Dr. Antoine Sanner and Prof. Dr. Lars Pastewka from the Department of Microsystems Engineering and the livMatS Cluster of Excellence at the University of Freiburg, Dr. Nityanshu Kumar and Prof. Dr. Ali Dhinojwala from the University of Akron and Prof. Dr. Tevis Jacobs from the University of Pittsburgh have published their results in the prestigious journal Science Advances.

“Our findings will make it possible to specifically control the adhesion properties of soft materials through surface roughness,” says Sanner. “They will also allow new and improved applications to be developed in soft robotics or production technology in the future, for example for grippers or placement systems.”

Research sheds light on new strategy to treat infertility

OHSU researchers are advancing a strategy based on somatic cell nuclear transfer to treat infertility through in vitro gametogenesis, or IVG. A study published today describes the science behind the technique demonstrated in a mouse model.
Photo Credit: OHSU/Christine Torres Hicks

New research from Oregon Health & Science University describes the science behind a promising technique to treat infertility by turning a skin cell into an egg that is capable of producing viable embryos.

Researchers at OHSU documented the technique, known as in vitro gametogenesis, or IVG, in a mouse model through preliminary steps that rely upon transferring the nucleus of a skin cell into a donated egg in which the nucleus has been removed. Using mice, the investigators coaxed the skin cell’s nucleus into reducing its chromosomes by half, so that it could then be fertilized by a sperm cell to create a viable embryo.

The study was published today in the journal Science Advances.

“The goal is to produce eggs for patients who don’t have their own eggs,” said senior author Shoukhrat Mitalipov, Ph.D., director of the OHSU Center for Embryonic Cell and Gene Therapy, and professor of obstetrics and gynecology, and molecular and cellular biosciences, in the OHSU School of Medicine.

The technique could be used by women of advanced maternal age or those who are unable to produce viable eggs due to previous treatment for cancer or other causes. It also raises the possibility of men in same-sex relationships having children who are genetically related to both parents.

Instead of attempting to differentiate induced pluripotent stem cells, or iPSCs, into sperm or egg cells, OHSU researchers are focused on a technique based on somatic cell nuclear transfer, in which a skin cell nucleus is transplanted into a donor egg stripped of its nucleus. In 1996, researchers famously used this technique to clone a sheep in Scotland named Dolly.

Nanosurgical tool could be key to cancer breakthrough

Electron microscopy image of the nanopipette.
Photo Credit: Dr Alexander Kulak

A nanosurgical tool - about 500 times thinner than a human hair - could give insights into cancer treatment resistance that no other technology has been able to do, according to a new study.

The high-tech double-barrel nanopipette, developed by University of Leeds scientists, and applied to the global medical challenge of cancer, has - for the first time - enabled researchers to see how individual living cancer cells react to treatment and change over time – providing vital understanding that could help doctors develop more effective cancer medication.  

The tool has two nanoscopic needles, meaning it can simultaneously inject and extract a sample from the same cell, expanding its potential uses. And the platform’s high level of semi-automation has sped up the process dramatically, enabling scientists to extract data from many more individual cells, with far greater accuracy and efficiency than previously possible, the study shows. 

Currently, techniques for studying single cells usually destroy them, meaning a cell can be studied either before treatment, or after.  

This device can take a “biopsy” of a living cell repeatedly during exposure to cancer treatment, sampling tiny extracts of its contents without killing it, enabling scientists to observe its reaction over time. 

During the study, the multi-disciplinary team, featuring biologists and engineers, tested cancer cells’ resistance to chemotherapy and radiotherapy using glioblastoma (GBM) - the deadliest form of brain tumor - as a test case, because of its ability to adapt to treatment and survive. 

Deciphering Catalysts: Unveiling Structure-Activity Correlations

The standard research paradigm uncovers the structure-property-activity relationships for the electrochemical CO2 reduction reaction (CO2RR) over SnO2. This picture illustrates the surface reconstruction induced by oxygen vacancies (1/1 ML coverage) and surface-active species (Sn layer) accountable for selective HCOOH production.
Illustration Credit: ©Hao Li et al.

In a new step towards combating climate change and transitioning to sustainable solutions, a group of researchers has developed a research paradigm that makes it easier to decipher the relationship between catalyst structures and their reactions.

Details of the researchers' breakthrough were published in the journal Angewandte Chemie.

Understanding how a catalyst's surface affects its activity can aid the design of efficient catalyst structures for specific reactivity requirements. However, grasping the mechanisms behind this relationship is no straightforward task given the complicated interface microenvironment of electrocatalysts.

Keeping the immune system in check

Image Credit: © Julian Nüchel, Center for Biochemistry Cologne

Researchers from the UoC’s Center for Biochemistry at the Faculty of Medicine and the UoC CECAD Cluster of Excellence in Aging Research have discovered that an excessive immune response can be prevented by the intramembrane protease RHBDL4. In a study now published in Nature Communications under the title ‘RHBDL4-triggered downregulation of COPII adaptor protein TMED7 suppresses TLR4-mediated inflammatory signaling’, a previously unknown regulatory mechanism is described: The cleavage of a cargo receptor by a so-called intramembrane protease reduces the localization of a central immune receptor on the cell surface and thereby the risk of an overreaction of the immune system.

Intramembrane proteases are reactive proteins that reside in the cell membranes. They form a special group of proteases because they cut proteins within cellular membranes. Many of these unusual proteases have not yet been sufficiently characterized and only a few of the molecules they can cleave – the so-called substrates – and thus their functions are known. One of these intramembrane proteases is RHBDL4. It is located in the endoplasmic reticulum, a large intracellular membrane system that is responsible, among other things, for the correct folding of newly synthesized proteins that are fed into the secretory route.

Marine algae implants could boost crop yields

Discovery could lead to more sustainable food supply
Photo Credit: Oktavianus Mulyadi

Scientists have discovered the gene that enables marine algae to make a unique type of chlorophyll. They successfully implanted this gene in a land plant, paving the way for better crop yields on less land. 

Finding the gene solves a long-standing mystery amongst scientists about the molecular pathways that allow the algae to manufacture this chlorophyll and survive. 

“Marine algae produce half of all the oxygen we breathe, even more than plants on land. And they feed huge food webs, fish that get eaten by mammals and humans,” said UC Riverside assistant professor of bioengineering and lead study author Tingting Xiang. “Despite their global significance, we did not understand the genetic basis for the algae’s survival, until now.”

The study, published in Current Biology, also documents another first-of-its-kind achievement: demonstrating that a land plant could produce the marine chlorophyll. Tobacco plants were used for this experiment, but in theory, any land plant may be able to incorporate the marine algae gene, allowing them to absorb a fuller spectrum of light and achieve better growth. 

Completely recycled viscose for the first time

Edvin Bågenholm-Ruuth
Photo Credit: Courtesy of Lund University

At present, viscose textiles are made of biomass from the forest, and there is no such thing as fully recycled viscose. Researchers at Lund University in Sweden have now succeeded in making new viscose – from worn-out cotton sheets.

Old textiles around the world end up at the rubbish tip and are often burned. In Sweden, they are generally burned to produce district heating. Extensive development work is being conducted to give old clothes and textiles a worthier ending. 

The planet really needs recycled textiles, as it takes a lot of energy, water and land to cultivate cotton and other plant sources for textiles. 

However, there are many challenges.

“Cellulose chains, the main component in plant fibers, are complex and long. Cotton textiles are also intensively treated with dyes, protective agents and other chemicals. And then there is all the ingrained grime in the form of skin flakes and fats,” says Edvin Bågenholm-Ruuth, doctoral student in chemical engineering at Lund University. 

Unveiling Inaoside A: An Antioxidant Derived from Mushrooms

Discovering a new antioxidant compound, Inaoside A from Laetiporus cremeiporus
Image credit: Atsushi Kawamura from Shinshu University, Japan

Natural products have unique chemical structures and biological activities and can play a pivotal role in advancing pharmaceutical science. In a pioneering study, researchers from Shinshu University discovered Inaoside A, an antioxidant derived from Laetiporus cremeiporus mushrooms. This breakthrough sheds light on the potential of mushrooms as a source of therapeutic bioactive compounds.

The search for novel bioactive compounds from natural sources has gained considerable momentum in recent years due to the need for new therapeutic agents to combat various health challenges. Among a diverse array of natural products, mushrooms have emerged as a rich reservoir of bioactive molecules with potential pharmaceutical and nutraceutical applications. The genus Laetiporus has attracted attention for its extracts exhibiting antimicrobial, antioxidant, and antithrombin bioactivities. The species Laetiporus cremeiporus, spread across East Asia, has also been reported to show antioxidant properties. However, the identification and characterization of specific antioxidant compounds from this species have not been conducted.

In a groundbreakng study, researchers led by Assistant Professor Atsushi Kawamura from the Department of Biomolecular Innovation, Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, along with Hidefumi Makabe from the Department of Agriculture, Graduate School of Science and Technology, Shinshu University, and Akiyoshi Yamada from the Department of Mountain Ecosystem, Institute for Mountain Science, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, recently discovered the antioxidant compound derived from L. cremeiporus.