Phys.org January 5, 2023 To learn more about how cancer cells size up surrounding tissue for stiffness and adapt their gecko-like movements in response a team of researchers at Virginia Polytechnic Institute developed a multiscale chemo mechanical whole-cell theory for mesenchymal migration. They developed a framework that coupled the subcellular focal adhesion dynamics at the cell-substrate interface with the cellular cytoskeletal mechanics and the chemical signaling pathways involving Rho GTPase proteins. In the presence of stiffness gradients and absence of chemical polarization, the cell moved toward an optimally stiff region from softer regions during durotaxis and from stiffer regions during […]
Rate of scientific breakthroughs slowing over time: Study
Phys.org January 4, 2023 Recent decades have witnessed exponential growth in the volume of new scientific and technological knowledge, thereby creating conditions that should be ripe for major advances. Yet studies suggest that progress is slowing in several major fields. A team of researchers in the US (University of Minnesota, University of Arizona) analysed the claims of new scientific and technological knowledge at scale across six decades, using data on 45 million papers and 3.9 million patents from six large-scale datasets, together with a new quantitative metric that characterizes how papers and patents change networks of citations in science and technology. They […]
Researchers develop eco-friendly materials capable of purifying water
Phys.org December 29, 2022 Current water purification technology shows slow adsorption of micropollutants and requires an energy-intensive process for VOCs removal. Researchers in South Korea have developed an efficient molecularly engineered covalent triazine framework (CTF) for rapid adsorption of micropollutants and VOC-intercepting performance using solar distillation. Supramolecular design and mild oxidation of CTFs (CTF-OXs) enabled hydrophilic internal channels and improve molecular sieving of micropollutants. CTF-OX showed rapid removal efficiency of micropollutants (>99.9% in 10 s) and it could be regenerated several times without performance loss. Uptake rates of selected micropollutants were high. Photothermal composite membrane fabrication using CTF-OX exhibited high […]
Researchers develop a light source that produces two entangled light beams
Phys.org January 3, 2023 In quantum entanglement when the systems interact with their surroundings, they almost immediately become disentangled. An international team of researchers (Brazil, USA – University of Oklahoma) produced a light source that produced two entangled light beams. The twin beams generated with a doubly resonant optical parameter oscillator (OPO) based on four-wave mixing in hot 85Rb vapor above threshold. They reconstructed the covariance matrix for several configurations and based on a full picture of the four-side band mode state, they studied entanglement between all possible bipartitions. They showed a robust generation of entanglement with stronger generation for […]
Researchers discover new process to create freestanding membranes of ‘smart’ materials
Phys.org January 3, 2023 The aggressive oxidizing conditions typically used in growing epitaxial oxides can damage graphene. A team of researchers in the US (University of Minnesota, Pacific Northwest National Laboratory, University of Wisconsin) used hybrid molecular beam epitaxy for SrTiO3 growth that did not require an independent oxygen source, thus avoided graphene damage. They produced epitaxial films with self-regulating cation stoichiometry. The film could be exfoliated and transferred to foreign substrates. The results opened the door to future studies of previously unattainable freestanding oxide nanomembranes grown in an adsorption-controlled manner by hybrid molecular beam epitaxy. According to the researchers […]
Scientists develop a cool new method of refrigeration
Science Daily January 4, 2023 Developing high-efficiency cooling with safe, low–global warming potential refrigerants is a grand challenge for tackling climate change. Caloric effect–based cooling technologies, such as magneto- or electrocaloric refrigeration, are promising but often require large, applied fields for a relatively low coefficient of performance and adiabatic temperature change. Researchers at UC Berkeley used the ionocaloric effect and the accompanying thermodynamic cycle as a caloric-based, all–condensed-phase cooling technology. Theoretical and experimental results showed higher adiabatic temperature change and entropy change per unit mass and volume compared with other caloric effects under low applied field strengths. They demonstrated the […]
Self-repairing healing solar cells recovering in the dark of the night
Nanowerk January 4, 2023 Perovskite solar cells degrade when exposed to sunlight, which results in decreasing performance over time. An international team of researchers (Sweden, Israel) demonstrated that metal halide perovskite solar cells, which degrade in sunlight, can rebuild their efficiency at night, when it’s dark. They exposed single crystals of lead-based metal halide perovskites to powerful lasers, which made them lose their ability to glow. However, they found that the material regained its photoluminescence following some recuperation time in darkness. They observed this in a solar cell’s thin, multicrystalline layer and the other one in single crystals. It is […]
A step towards solar fuels out of thin air
Science Daily January 4, 2023 Taking inspiration from the way plants can convert sunlight into chemical energy using carbon dioxide from the air, researchers in Switzerland have invented a solar-powered artificial leaf, built on a novel electrode capable of harvesting water from the air for conversion into hydrogen fuel. The system combines semiconductor-based technology and the electrodes that are porous and transparent. When the device was simply exposed to sunlight, it took water from the air and produced hydrogen gas. The coating of various semiconductors on the substrates was established including Fe2O3 (chemical bath deposition), CuSCN and Cu2O (electrodeposition), and […]
Study examines how many scientists a region needs to achieve dominance in a field
Phys.org December 29, 2022 The conditions for the emergence of a leading regional scientific environment are poorly understood. The existence of a critical mass of scientists is often assumed. An international team of researchers (Austria, the Netherlands, South Africa, USA – Santa Fe Institute) used a unique dataset of global scientific activity and researcher mobility over several decades to show empirical evidence in three scientific areas (semiconductor research, embryonic stem cells, and Internet research) that the process of scientific knowledge accumulation was remarkably general and applied to practically all regions. Scale-free growth patterns suggested that regions that move early into […]
Study explores topological beaming of light
Phys.org December 30, 2022 Nanophotonic light emitters are key components in numerous application areas because of their compactness and versatility. An international team of researchers (South Korea, UK, USA – Pennsylvania State University, University of Pittsburg, Singapore) has proposed a topological beam emitter structure that takes advantage of submicrometer footprint size, small divergence angle, high efficiency, and adaptable beam shaping capability. The proposed structure consists of a topological junction of two guided-mode resonance gratings inducing a leaky Jackiw-Rebbi state resonance which leads to in-plane optical confinement with funnel-like energy flow and enhanced emission probability, resulting in highly efficient optical beam […]