Lifeboat Foundation

A new study from a team of McGill University and Vanderbilt University researchers is shedding light on our understanding of the molecular origins of some forms of autism and intellectual disability.

For the first time, researchers were able to successfully capture atomic resolution images of the fast-moving ionotropic glutamate receptor (iGluR) as it transports calcium. iGluRs and their ability to transport calcium are vitally important for many brain functions such as vision or other information coming from sensory organs. Calcium also brings about changes in the signaling capacity of iGluRs and nerve connections, which are key cellular events that lead to our ability to learn new skills and form memories.

IGluRs are also key players in brain development and their dysfunction through genetic mutations has been shown to give rise to some forms of autism and intellectual disability. However, basic questions about how iGluRs trigger biochemical changes in the brain’s physiology by transporting calcium have remained poorly understood.

Explaining isolated steps on the road from simple chemicals to complex living organisms is not enough. Looking at the big picture could help to bridge rifts in this fractured research field.

Studying a rock is like reading a book. The rock has a story to tell, says Frieder Klein, an associate scientist in the Marine Chemistry & Geochemistry Department at the Woods Hole Oceanographic Institution (WHOI).

The rocks that Klein and his colleagues analyzed from the submerged flanks of the St. Peter and St. Paul Archipelago in the St. Paul’s oceanic transform fault, about 500 km off the coast of Brazil, tell a fascinating and previously unknown story about parts of the geological carbon cycle.

Transform faults, where tectonic plates move past each other, are one of three main plate boundaries on Earth and about 48,000 km in length globally, with the others being the global mid-ocean ridge system (about 65,000 km) and subduction zones (about 55,000 km).

Longstanding challenges in biomedical research such as monitoring brain chemistry and tracking the spread of drugs through the body require much smaller and more precise sensors. A new nanoscale sensor that can monitor areas 1,000 times smaller than current technology and can track subtle changes in the chemical content of biological tissue with sub-second resolution, greatly outperforming standard technologies.

The device, developed by researchers at the University of Illinois Urbana-Champaign, is silicon-based and takes advantage of techniques developed for microelectronics manufacturing. The small device size enables it to collect chemical content with close to 100% efficiency from highly localized regions of tissue in a fraction of a second. The capabilities of this new nanodialysis device are reported in the journal ACS Nano.

“With our nanodialysis device, we take an established technique and push it into a new extreme, making biomedical research problems that were impossible before quite feasible now,” said Yurii Vlasov, a U. of I. electrical & computer engineering professor and a co-lead of the study. “Moreover, since our devices are made on silicon using microelectronics fabrication techniques, they can be manufactured and deployed on large scales.”

The search for habitable exoplanets involves looking for planets with similar conditions to the Earth, such as liquid water, a suitable temperature range and atmospheric conditions. One crucial factor is the planet’s position in the habitable zone, the region around a star where liquid water could potentially exist on the planet’s surface. NASA’s Kepler telescope, launched in 2009, revealed that 20–50% of visible stars may host such habitable Earth-sized rocky planets. However, the presence of liquid water alone does not guarantee a planet’s habitability. On Earth, carbon compounds such as carbon dioxide (CO₂), methane (CH4), and carbon monoxide (CO) played a crucial role in shaping the climate and biogeochemistry and could have contributed to the emergence of life.

Taking this into consideration, a recent study by Associate Professor Kazumi Ozaki from Tokyo Institute of Technology, along with Associate Researcher Yasuto Watanabe from The University of Tokyo, aims to expand the search for habitable planets. Published in the Astrophysical Journal(External site) on 10 January 2024, the researchers used atmospheric modeling to identify conditions that could result in a CO-rich atmosphere on Earth-like planets that orbit sun-like (F-, G-, and K-type) stars. This phenomenon, known as CO runaway, is suggested by atmospheric models to have possibly occurred in early planetary atmospheres, potentially favoring the emergence of life.

“The possibility of CO runaway is critical in resolving the fundamental problem regarding the origin of life on Earth because various organic compounds suitable for the prebiotic chemistry are more likely to form in a CO-rich atmosphere than in a CO2-rich atmosphere,” explains Dr. Ozaki.

RuO2 has been established as the benchmark catalyst for the oxygen evolution reaction (OER). However, the low precious metal content compared to other OER industrial catalysts like RuO2, Pt/C, and IrO2 makes a hybrid heterosurface of RuO2 and F-doped graphene (RuO2@FGr) an excellent catalyst with a high current density. Moreover, the advantage of graphene support increases stability. We investigated the mechanism of the OER on RuO2@FGr using density functional theory (DFT) and the computational hydrogen electrode model (CHEM). In CHEM, the adsorption energy of the reactive intermediates is considered for the reduction potential calculation. This is followed by free energy calculation and, eventually, overpotential calculation using standard or reversible hydrogen electrodes (SHE/RHE). Computational OER activity calculated in the gas phase using density functional theory (DFT) cannot explain the contribution of the condensed phase, water organization energy, the kinetics of the elementary steps, and electrochemical contribution. The current study will address the issue by implementing an implicit solvation model and the electrostatic contribution by considering the charge extrapolation model. We used molecular RuO2 to mimic the exact experimental weight percentage. Fluorine intercalation doping improves the binding of oxygen-based intermediate species to the reactive surface due to a shift in the d-band center toward the Fermi level. The graphene sheet behaves as a conductor after fluorine doping, and the electron density contribution near the Fermi level is clearly distinguished from the projected density of states (PDOS). Using the implicit solvation model with altered parameters, we find improvements in the reaction barrier for hydroperoxo formation. An overpotential of 0.40 V vs RHE is obtained for the cavity shape parameter and charge density cutoff parameter of 0.8 and 0.0035 Å–3. For completion, we implement the constant potential model (CPM) to extrapolate our results calculated at the nonzero potential environment to 0.0 V potential. The mean energy path computed using the climbing image nudged elastic band provides the activation and reaction energy, and the values are extrapolated to 0.0 V RHE using the CPM correction. Implementing both thermochemical and electrochemical corrections simultaneously, we can find a reasonable overpotential of the studied catalytic reaction.

The Seva Sustainable Sanitation innovation is a smart, electro-chemical toilet unit, which is suitable for use in off-grid rural areas of developing countries. It can turn toilet wastewater into disinfected water, using the power from its mounted solar panels to sterilise and clarify it. Macronutrients such as carbon, nitrogen, and phosphorus can be nearly fully recovered from the waste, leaving nothing but water that is recycled for flushing or irrigation. The toilet unit is also equipped with sensors, a mobile phone-based maintenance guide, and smart grid technology that empowers anyone in the community to repair the system when necessary. When a toilet is out of order, the technology automatically directs users to other nearby sanitation systems. So far, the solution has been deployed in four countries.

Relying on sub-wavelength nanostructures, metasurfaces have been shown as promising candidates for replacing conventional free-space optical components by arbitrarily manipulating the amplitude, phase, and polarization of optical wavefronts in certain applications^1,2,3. In recent years, the scope of their applications has been expanded towards complete spatio-temporal control through the introduction of active metasurfaces. These developments open up exciting new possibilities for dynamic holography⁴, faster spatial light modulators⁵, and fast optical beam steering for LiDAR⁶. Large efforts have been channeled into various modulation mechanisms⁷. Microelectromechanical and nanoelectromechanical systems (MEMS and NEMS)^8,9,10,11 have the advantages of low-cost and CMOS-compatibility, but the speed is limited up to MHz. Phase-change materials^12,13,14 have fast, drastic, and non-volatile refractive index change, but lack continuous refractive index tuning and have a limited number of cycles constraining applicability to reconfigurable devices. Through molecule reorientation, liquid crystal can have index modulation over 10%, while under relatively low applied voltages Tunable liquid crystal metasurfaces, U.S. patent number 10,665,953 [Application Number 16/505,687]¹⁵. Techniques of liquid crystal integration have also advanced after decades of development. However, the tuning speeds are limited to kHz range¹⁶. Thermal-optic effects can induce relatively large refractive index changes^17,18, but the speed is inherently limited and the on-chip thermal management can be challenging. The co-integration of transparent conductive oxide and metallic plasmonic structures^5,6 has been demonstrated in epsilon-near-zero (ENZ) regime to control the wavefront of reflected light, but the low reflection amplitude induced by the optical loss of the materials and the ENZ regime is unavoidable.

In modern photonics, a multitude of technologies for tunable optics and frequency conversion^19,20 are realized with nonlinear materials that have low loss and a strong χ effect, such as lithium niobate^21,22, aluminum nitride²³, and organic electro-optic (OEO) materials²⁴. Their ultrafast responses make it possible to use RF or millimeter-wave control²⁵. Developments in computational chemistry have also led to artificially engineered organic molecules that have record-high nonlinear coefficients with long-term and high-temperature stability^26,27. However, their potential in modifying free-space light has been relatively unexplored until recently. Several OEO material-hybrid designs have demonstrated improved tunability of metasurfaces^28,29,30. Utilizing dielectric resonant structures and RF-compatible coplanar waveguides, a free-space silicon-organic modulator has recently accomplished GHz modulation speed³¹. However, all demonstrations to date require high operating voltages ± 60V, due to low resonance tuning capability (frequency shift / voltage), which hinders their integration with electronic chips.

In this work, we propose combining high-Q metasurfaces based on slot-mode resonances with the unique nano-fabrication techniques enabled by OEO materials, which drastically reduces the operating voltage. The low voltage is mainly achieved from the ability to place the electrodes in close proximity to each other while hosting high-Q modes in between and the large overlap of the optical and RF fields in OEO materials. In the following sections, we first provide the design concepts and considerations for achieving a reduced operating voltage. Next, we numerically demonstrate the advantage of a particular selected mode compared to other supported modes in the structure. Finally, we experimentally realize our concepts and characterize the performance of the electro-optic metasurface.

Blood–brain barrier: A physical and biochemical boundary between the bloodstream and the parenchyma of the central nervous system (CNS).

Editorial from The New England Journal of Medicine — Sounding Out the Blood–Brain Barrier.