Lifeboat Foundation

Self-assembled materials are attractive for next-generation materials, but their potential to assemble at the nanoscale and form nanostructures (cylinders, lamellae etc.) remains challenging. In a recent report, Xundu Feng and colleagues at the interdisciplinary departments of chemical and environmental engineering, biomolecular engineering, chemistry and the center for advanced low-dimension materials in the U.S., France, Japan and China, proposed and demonstrated a new approach to prevent the existing challenges. In the study, they explored size-selective transport in the water-continuous medium of a nanostructured polymer template formed using a self-assembled lyotropic H₁ (hexagonal cylindrical shaped) mesophase (a state of matter between liquid and solid). They optimized the mesophase composition to facilitate high-fidelity retention of the H₁ structure on photoinduced crosslinking.

The resulting nanostructured polymer material was mechanically robust with internally and externally crosslinked nanofibrils surrounded by a continuous aqueous medium. The research team fabricated a membrane with size selectivity at the 1 to 2 nm length scale and water permeabilities of ~10 liters m⁻² hour⁻¹ bar⁻¹ μm. The membranes displayed excellent anti-microbial properties for practical use. The results are now published on Science Advances and represent a breakthrough for the potential use of self-assembled membrane-based nanofiltration in practical applications of water purification.

Membrane separation for filtration is widely used in diverse technical applications, including seawater desalination, gas separation, food processing, fuel cells and the emerging fields of sustainable power generation and distillation. During nanofiltration, dissolved or suspended solutes ranging from 1 to 10 nm in size can be removed. New nanofiltration membranes are of particular interest for low-cost treatment of wastewaters to remove organic contaminants including pesticides and metabolites of pharmaceutical drugs. State-of-the-art membranes presently suffer from a trade-off between permeability and selectivity where increased permeability can result in decreased selectivity and vice-versa. Since the trade-off originated from the intrinsic structural limits of conventional membranes, materials scientists have incorporated self-assembled materials as an attractive solution to realize highly selective separation without compromising permeability.

Circa 2017

We have reported a new phenomenon in acute wound healing following the use of intracellular ATP delivery—extremely rapid tissue regeneration, which starts less than 24 h after surgery, and is accompanied by massive macrophage trafficking, in situ proliferation, and direct collagen production. This unusual process bypasses the formation of the traditional provisional extracellular matrix and significantly shortens the wound healing process. Although macrophages/monocytes are known to play a critical role in the initiation and progression of wound healing, their in situ proliferation and direct collagen production in wound healing have never been reported previously. We have explored these two very specific pathways during wound healing, while excluding confounding factors in the in vivo environment by analyzing wound samples and performing in vitro studies. The use of immunohistochemical studies enabled the detection of in situ macrophage proliferation in ATP-vesicle treated wounds. Primary human macrophages and Raw 264.7 cells were used for an in vitro study involving treatment with ATP vesicles, free Mg-ATP alone, lipid vesicles alone, Regranex, or culture medium. Collagen type 1α 1, MCP-1, IL-6, and IL-10 levels were determined by ELISA of the culture supernatant. The intracellular collagen type 1α1 localization was determined with immunocytochemistry. ATP-vesicle treated wounds showed high immunoreactivity towards BrdU and PCNA antigens, indicating in situ proliferation. Most of the cultured macrophages treated with ATP-vesicles maintained their classic phenotype and expressed high levels of collagen type 1α1 for a longer duration than was observed with cells treated with Regranex. These studies provide the first clear evidence of in situ macrophage proliferation and direct collagen production during wound healing. These findings provide part of the explanation for the extremely rapid tissue regeneration, and this treatment may hold promise for acute and chronic wound care.

Wound healing is a complex and dynamic process involving the replacement of devitalized and missing structures. The traditional view of wound healing is that it involves hemostasis, inflammation, proliferation, and remodeling, and these steps result in a lag of 3–6 d before reepithelialization starts [1,2]. We have discovered that the intracellular delivery of adenosine triphosphate using ATP-vesicles as an acute wound treatment enhances wound healing [3,4]. The most unprecedented finding was that new tissue started to generate within 24 h, and it continued to grow to eliminate the wound cavity quickly [4–6]. This growth was attained by early and massive monocyte/macrophage trafficking, proliferation, and fast collagen production for direct formation of extracellular matrix (ECM).

A group of researchers led by Skoltech Professor Pavel Troshin studied coordination polymers, a class of compounds with scarcely explored applications in metal-ion batteries, and demonstrated their possible future use in energy storage devices with a high charging/discharging rate and stability. The results of their study were published in the journal Chemistry of Materials.

The charging/discharging rate is one of the key characteristics of lithium-ion batteries. Most modern commercial batteries need at least an hour to get fully charged, which certainly limits the scope of their application, in particular, for electric vehicles. The trouble with active materials, such as the most popular anode material, graphite, is that their capacity decays significantly, as their charging rate increases. To retain the battery capacity at high charging rates, the active electrode materials must have high electronic and ionic conductivity, which is the case with the newly-discovered coordination polymers that are derived from aromatic amines and salts of transition metals, such as nickel or copper. Although these compounds hold a great promise, their application in lithium-ion batteries remains virtually unexplored.

A recent study undertaken by a group of scientists from Skoltech and the Institute for Problems of Chemical Physics of RAS led by Professor P. Troshin in collaboration with the University of Cologne (Germany) and the Ural Federal University, focused on tetraaminobenzene-based linear polymers of nickel and copper. Although the linear polymers exhibited much lower initial electronic conductivity as compared to their two-dimensional counterparts, it transpired that they can be used as anode materials that get charged/discharged in less than a minute, because their conductivity increases dramatically after the first discharge due to lithium doping.

People in Ethiopia did not live in low valleys during the last ice age. Instead they lived high up in the inhospitable Bale Mountains. There they had enough water, built tools out of obsidian and relied mainly on giant rodents for nourishment. This discovery was made by an international team of researchers led by Martin Luther University Halle-Wittenberg (MLU) in cooperation with the Universities of Cologne, Bern, Marburg, Addis Ababa and Rostock. In the current issue of “Science”, the researchers provide the first evidence that our African ancestors had already settled in the mountains during the Palaeolithic period, about 45,000 years ago.

At around 4,000 metres above sea level, the Bale Mountains in southern Ethiopia are a rather inhospitable region. There is a low level of oxygen in the air, temperatures fluctuate sharply, and it rains a lot. “Because of these adverse living conditions, it was previously assumed that humans settled in the Afro-Alpine region only very lately and for short periods of time,” says Professor Bruno Glaser, an expert in soil biogeochemistry at MLU. Together with an international team of archaeologists, soil scientists, palaeoecologists, and biologists, he has been able to show that this assumption is incorrect. People had already begun living for long periods of time on the ice-free plateaus of the Bale Mountains about 45,000 years ago during the Middle Pleistocene Epoch. By then the lower valleys were already too dry for survival.

For several years, the research team investigated a rocky outcrop near the settlement of Fincha Habera in the Bale Mountains in southern Ethiopia. During their field campaigns, the scientists found a number of stone artefacts, clay fragments and a glass bead. “We also extracted information from the soil as part of our subproject,” says Glaser. Based on the sediment deposits in the soil, the researchers from Halle were able to carry out extensive biomarker and nutrient analyses as well as radiocarbon dating and thus draw conclusions as to how many people lived in the region and when they lived there. For this work, the scientists also developed a new type of palaeothermometer which could be used to roughly track the weather in the region — including temperature, humidity and precipitation. Such analyses can only be done in natural areas with little contamination, otherwise the soil profile will have changed too much by more recent influences.

Researchers in the Department of Physics of ETH Zurich have measured how electrons in so-called transition metals get redistributed within a fraction of an optical oscillation cycle. They observed the electrons getting concentrated around the metal atoms within less than a femtosecond. This regrouping might influence important macroscopic properties of these compounds, such as electrical conductivity, magnetization or optical characteristics. The work therefore suggests a route to controlling these properties on extremely fast time scales.

The distribution of electrons in transition metals, which represent a large part of the periodic table of chemical elements, is responsible for many of their interesting properties used in applications. The magnetic properties of some of the members of this group of materials are, for example, exploited for data storage, whereas others exhibit excellent electrical conductivity. Transition metals also have a decisive role for novel materials with more exotic behaviour that results from strong interactions between the electrons. Such materials are promising candidates for a wide range of future applications.

In their experiment, whose results they report in a paper published today in Nature Physics, Mikhail Volkov and colleagues in the Ultrafast Laser Physics group of Prof. Ursula Keller exposed thin foils of the transition metals titanium and zirconium to short laser pulses. They observed the redistribution of the electrons by recording the resulting changes in optical properties of the metals in the extreme ultraviolet (XUV) domain. In order to be able to follow the induced changes with sufficient temporal resolution, XUV pulses with a duration of only few hundred attoseconds (10^-18 s) were employed in the measurement. By comparing the experimental results with theoretical models, developed by the group of Prof. Angel Rubio at the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, the researchers established that the change unfolding in less than a femtosecond (10^-15 s) is due to a modification of the electron localization in the vicinity of the metal atoms.

In the deep of the ocean, where the sun’s rays struggle to penetrate, organisms lurk that could solve the biggest medical crisis facing humanity.

Far below the surface bacteria are engaged in warfare with each other — and to do so they make an antibiotic so strong it can destroy the toughest superbugs in our hospitals.

“But there’s a problem,” Rebecca Goss, a professor of organic chemistry at the University of St Andrews, said. “It disintegrates in sunlight.”

Scientists at work in laboratory. Photo: Public domain via Wikicommons.

CTech – When chemistry Nobel laureate Michael Levitt met his wife two years ago, he didn’t know it would lead to a wonderful friendship with a young Israeli scientist. When Israeli scientist Shahar Barbash decided to found a startup with the aim of cutting down the time needed to develop new medicine, he didn’t know that a friend’s wedding would help him score a meeting with a man many want to meet but few do. But Levitt’s wife is an old friend of Barbash’s parents, and the rest, as they say, is history.

One of the joys of being an old scientist is to encourage extraordinary young ones, Levitt, an American-British-Israeli biophysicist and a professor at Stanford University since 1987, said in a recent interview with Calcalist. He might have met Barbash because his wife knew his family, but that is not enough to make him go into business with someone, Levitt said. “I got on board because his vision excited me, even though I thought it would be very hard to realize.”

Abstract: The large, error-correcting quantum computers envisioned today could be decades away, yet experts are vigorously trying to come up with ways to use existing and near-term quantum processors to solve useful problems despite limitations due to errors or “noise.”

A key envisioned use is simulating molecular properties. In the long run, this can lead to advances in materials improvement and drug discovery. But not with noisy calculations confusing the results.

Now, a team of Virginia Tech chemistry and physics researchers have advanced quantum simulation by devising an algorithm that can more efficiently calculate the properties of molecules on a noisy quantum computer. Virginia Tech College of Science faculty members Ed Barnes, Sophia Economou, and Nick Mayhall recently published a paper in Nature Communications detailing the advancement.