NASA’s new electric propulsion engine set a U.S. power record and could transform future Mars missions. The thrusters use much less fuel than chemical rockets while gradually reaching extremely high speeds.
Category: chemistry – Page 4
The nocebo effect: How prior experience and verbal suggestion rewire the brain to make pain worse
Researchers have a better understanding of the nocebo effect and the neuroscience behind it all. Opposite of the better-known placebo effect, where positive expectations trigger genuine pain relief, the nocebo effect is the experience from negative expectations, created by prior experience, verbal suggestion, or social observation, which can drive anxiety and make pain worse.
A new study published in Nature Communications, by researchers at the University of Toronto Mississauga and McGill University, identified a brain pathway through which negative expectations can amplify pain. The findings, generated independently by the two labs without prior coordination, converged on the neurochemical cholecystokinin (CCK), which has previously been linked to nocebo pain responses in humans.
The researchers identified a specific brain pathway through which CCK acts, traveling from the brain’s anterior cingulate cortex (ACC), a region involved in the emotional dimensions of pain, to a midbrain structure called the lateral periaqueductal gray (lPAG), where it increases pain sensitivity.
My Video Tour of Alcor and Interview with CEO Max More
What counts as death? And who gets to decide?
In the summer of 2013, I traveled to Scottsdale, Arizona to visit the Alcor Life Extension Foundation, the world’s leading cryonics organization, founded in 1972. CEO Dr. Max More gave me a full tour of the facilities and walked me through the entire process: from the moment clinical death is declared, through controlled cooling and vitrification, to the cryo-tanks holding (at the time) 117 patients in long-term storage.
I also asked him, somewhat selfishly, whether my big bald head would fit comfortably in a neuro-patient container.
After the tour, Max sat down with me for a 25-minute conversation that covered:
Affordability and the real cost of membership Why minimizing cooling delays after clinical death is critical, and what long-distance members do about it Preserving pets, because of course people ask Chemical brain preservation as an alternative path The importance of protecting the neuron’s microtubules The case for an X Prize style competition to reduce tissue damage Where cryonics sits inside the broader transhumanist project.
My favorite line from Max, the one I still come back to:
Mitochondrial checkpoint enables dendritic cells to activate T lymphocytes against viruses, tumors
A study led by researchers at the Centro Nacional de Investigaciones Cardiovasculares (CNIC) has identified a mitochondrial “checkpoint” that enables dendritic cells to efficiently activate T lymphocytes against viruses and tumors. Dendritic cells are immune cells that detect threats and activate the body’s defenses, acting as “sentinels” that instruct T lymphocytes on what to attack.
The study, published in Science Immunology, shows that restoring the internal chemical imbalance caused by defective mitochondrial function in dendritic cells restores the capacity of immune cells to defend the body against infection. The findings could open new avenues for improving cancer immunotherapy.
The study reveals that the ability of dendritic cells to activate T lymphocytes depends on an unexpected mechanism: the proper functioning of mitochondrial complex I, a key mitochondrial component. Mitochondrial complex I acts as a “metabolic switch” that is essential for the ability of dendritic cells to convert viral or tumor-derived material into effective immune activation signals and trigger a strong T-cell response.
Some technologies use accelerated natural processes to capture carbon, but can they store it durably?
Natural geological processes have been regulating Earth’s climate for millions of years. Accelerated versions of these processes are now being promoted as technologies to draw down carbon from the atmosphere—and some are rapidly moving from concept to real-world deployments.
Two such technologies are known as enhanced weathering, which speeds up the chemical breakdown of certain rocks, and ocean alkalinity enhancement, which increases the ocean’s natural ability to remove carbon dioxide from the air.
Startups backed by tech companies including Google and Microsoft are already applying these technologies in field trials. Investment in the sector is rising rapidly, with large-scale trials underway and carbon credits beginning to appear on voluntary markets.
Novel porous gel changes color, shrinks and hardens when it detects target molecules
Researchers at Kyoto University and Tohoku University have developed a new porous polymer gel that selectively recognizes specific molecules (referred to as “guests” in the study) through coordination chemistry and converts these invisible molecular-scale interactions into strikingly visible, macroscale deformation.
The study demonstrates how subtle differences in molecular structure can directly alter the shape, color, and mechanical properties of a soft material, opening new possibilities for “smart” stimuli-responsive materials and molecularly programmable soft matter that can sense and react to its environment.
Molecular recognition is a central concept in supramolecular chemistry and biology, where molecules selectively interact through precisely arranged chemical interactions. While most artificial molecular recognition systems rely on noncovalent interactions such as hydrogen bonding, the present study instead exploits coordination interactions —a type of chemical “handshake”—between metal centers and electron-rich guest molecules.
Dr. Gregory Fahy on major evidence for human cryopreservation
Dr. Fahy is the Vice President and Chief Scientific Officer at 21st Century Medicine, Inc, and has co-founded Intervene Immune, a company developing clinical methods to reverse immune system aging. He was the 2022–2023 president of the Society for Cryobiology. Dr. Fahy is the lead author of a recent paper, “Ultrastructural and Histological Cryopreservation of Mammalian Brains by Vitrification” – the main topic of our conversation.
In December of 2014, I worked with Dr. Fahy to cryopreserve Dr. Stephen Coles under special conditions, with his permission to extract brain samples and test them for preservation quality. We did not know what the results would be. If bad, that would be discouraging for cryonics. In fact, the results were excellent, as Dr. Fahy details.
We discuss the Coles case and the results of the cerebral cortical biopsy. The paper includes results from rabbit brains. We also discuss the relative resilience of the brain compared to other organs when it comes to fracturing; how cryoprotectants prevent ice formation even when the blood-brain barrier remains closed; whether biostasis organizations should be using blood-brain barrier opening agents; Dr. Fahy’s thoughts about chemical preservation and the role of a combination of cryo an chemo, known as aldehyde-stabilized cryopreservation (ASC), and more.
Molecule-in-a-crystal system could boost quantum computing via chemically engineered qubits
Within a crystal’s atomic structure, tiny atomic-scale flaws will naturally occur where electrons can become trapped. These defects have emerged as one of the leading platforms for quantum information processing. Through a new study, posted to the preprint server arXiv, Ilai Schwartz and colleagues at NVision Imaging Technologies in Germany have shown that a specialized molecule embedded inside a crystal could take this approach a step further, offering a more controllable and versatile route to building quantum systems.
Unlike the classical computers we use every day, quantum computers encode information in the quantum states of qubits, which can exist in combinations of 0 and 1 simultaneously. This quantum information can’t simply be copied or transmitted in the same way as classical bits: when a qubit is measured, its quantum state is disturbed, making it impossible to transmit its information directly.
To tackle this problem, qubits must be connected to photons, which can transmit their quantum information between distant parts of a network. This connection relies on what physicists call a “spin-photon interface”: a structure in which the quantum state of an electron or nucleus can be reliably written, read, and communicated via light.