Lifeboat Foundation

At first glance, it might seem obvious that atoms touch each other, especially when you consider the material world around us. From the objects we handle to the materials we utilize, everything indeed appears very solid. However, the question of whether atoms actually “touch” as we understand it on a human level is far more intricate than it might seem. In fact, the answer hinges on how we define “touch,” a concept that shifts significantly at the atomic scale.

At the human scale, “touch” generally refers to the meeting of well-defined surfaces. For instance, when you place a glass on a table, you might say the two objects are touching because their outer surfaces overlap. However, at the atomic scale, this notion of contact becomes much more ambiguous. An atom is neither a solid object nor an entity with a clear boundary. It consists of a central nucleus made up of protons and neutrons, surrounded by a cloud of constantly moving electrons. This unpredictable movement means the electron cloud does not create a fixed and defined surface.

To understand what contact means between atoms, one must look into the internal structure of these particles and the interactions occurring between their electrons. Each atom is made up of a central nucleus surrounded by an electron cloud, which isn’t located at a specific spot but occupies areas known as orbitals. These orbitals are regions of probability where it’s more or less likely to find an electron at any given time. Their shape and organization vary depending on the chemical element of the atom, giving each type of atom unique characteristics.

Decades of research have established that chronic stress—from money worries, job problems, family tensions, or other sources—causes chemical changes in the body. In a new study, researchers have identified biological changes induced by stress that may help explain how it could cause a tumor to spread, or metastasize.

To conduct the study, the researchers used two established methods for modeling stress in mice. One is designed to mimic exposure to constant, low-level, predictable stress. The other simulates intermittent, unpredictable, mild stress.

They used these methods to induce chronic stress in two different mouse models of breast cancer. In both models, when the mice were exposed to stress using either method, they had both larger mammary tumors and more lung metastases than mice not exposed to stress.

Continue reading “Chronic Stress-Induced NETs May Aid Cancer Metastasis” »

Misfolded proteins may preserve postmortem brains well after other tissues have decayed.

By Kermit Pattison edited by Tanya Lewis

No part of our body is as perishable as the brain. Within minutes of losing its supply of blood and oxygen, our delicate neurological machinery begins to suffer irreversible damage. The brain is our most energy-greedy organ, and in the hours after death, its enzymes typically devour it from within. As cellular membranes rupture, the brain liquifies. Within days, microbes may consume the remnants in the stinky process of putrefaction. In a few years, the skull becomes just an empty cavity.

All solids have a crystal structure that shows the spatial arrangement of atoms, ions or molecules in the lattice. These crystal structures are often determined by a method known as X-ray diffraction technique (XRD).

These crystal structures play an import role in determining many physical properties such as the electronic band structure, cleavage and explains many of their physical and chemical properties.

This article aims to discuss an approach to identify these structures by various machine learning and deep learning methods. It demonstrates how supervised machine learning and deep learning approaches and help in determining various crystal structures of solids.

Princeton engineers have developed a scalable 3D printing technique to produce soft plastics with customizable stretchiness and flexibility, while also being recyclable and cost-effective—qualities rarely combined in commercially available materials.

In a study published in Advanced Functional Materials, a team led by Emily Davidson detailed how they used thermoplastic elastomers—a class of widely available polymers—to create 3D-printed structures with adjustable stiffness. By designing the 3D printer’s print path, the engineers could program the plastic’s physical properties, allowing devices to stretch and flex in one direction while remaining rigid in another.

Continue reading “Stretchable, Flexible, Recyclable: Princeton Scientists Develop Fantastic New Material” »

Zhao, N., Zhang, CJ., Zhang, X. et al. npj Regen Med 9, 42 (2024). https://doi.org/10.1038/s41536-024-00387-7

Chemical Sensing.

RNA aptamers light up after ligand reacts.

Designing an organic reaction that works in cells is easier than designing a riboswitch, chemist says.

Researchers have successfully stabilized ferrocene molecules on a flat substrate for the first time, enabling the creation of an electronically controllable sliding molecular machine.

Artificial molecular machines, composed of only a few molecules, hold transformative potential across diverse fields, including catalysis, molecular electronics, medicine, and quantum materials. These nanoscale devices function by converting external stimuli, such as electrical signals, into controlled mechanical motion at the molecular level.

Ferrocene—a unique drum-shaped molecule featuring an iron (Fe) atom sandwiched between two five-membered carbon rings—is a standout candidate for molecular machinery. Its discovery, which earned the Nobel Prize in Chemistry in 1973, has positioned it as a foundational molecule in this area of study.

Exploiting an ingenious combination of photochemical (i.e., light-induced) reactions and self-assembly processes, a team led by Prof. Alberto Credi of the University of Bologna has succeeded in inserting a filiform molecule into the cavity of a ring-shaped molecule, according to a high-energy geometry that is not possible at thermodynamic equilibrium. In other words, light makes it possible to create a molecular “fit” that would otherwise be inaccessible.

“We have shown that by administering light energy to an aqueous solution, a molecular self-assembly reaction can be prevented from reaching a thermodynamic minimum, resulting in a product distribution that does not correspond to that observed at equilibrium,” says Alberto Credi.

“Such a behavior, which is at the root of many functions in living organisms, is poorly explored in artificial molecules because it is very difficult to plan and observe. The simplicity and versatility of our approach, together with the fact that visible light—i.e., sunlight—is a clean and sustainable energy source, allow us to foresee developments in various areas of technology and medicine.”