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Natural-language AI helps chemists design molecules step by step

Designing molecules is one of chemistry’s most complex challenges. From life-saving drugs to advanced materials, each compound requires a precise sequence of reactions. Planning these steps demands both technical knowledge and strategic insight, making it a task that often relies on years of experience.

Two problems plague much of modern chemistry. The first is retrosynthesis: Chemists start from a target molecule and work backward to identify simpler building blocks and viable reaction pathways. Retrosynthesis involves countless decisions, from choosing starting materials to determining when to form rings or protect sensitive functional groups. While computers can explore vast “chemical spaces,” they often struggle to capture the strategic reasoning used by human experts.

The second problem is reaction mechanisms. These describe how chemical reactions unfold step by step through the movements of electrons. Mechanistic insight helps scientists predict new reactions, improve efficiency, and reduce costly trial and error. Existing computational methods can generate many possible pathways, but often lack the chemical intuition needed to identify the most plausible ones.

Blood and spinal fluid proteins reveal distinct fingerprints of four brain diseases

Researchers at WashU Medicine have uncovered new molecular insights into Alzheimer’s disease, Parkinson’s disease and other forms of dementia by analyzing thousands of proteins in both cerebrospinal fluid and blood plasma. The study, led by Carlos Cruchaga, the Barbara Burton & Reuben Morriss III Professor in the Department of Psychiatry and director of the NeuroGenomics and Informatics Center at WashU Medicine, represents one of the largest and most comprehensive multi-tissue analyses of proteins across multiple neurodegenerative diseases to date. The findings raise the possibility of developing blood tests for earlier and more precise diagnosis of these conditions.

In the study, published March 30 in Neuron, a multi-institutional team of clinicians, neuroscientists and data scientists, steered by Muhammad Ali, an assistant professor of psychiatry at WashU Medicine and first author of the study, analyzed nearly 7,000 proteins in samples of spinal fluid and blood from nearly 6,000 people—including people with neurodegenerative diseases as well as healthy controls—to better understand four major neurodegenerative diseases: Alzheimer’s disease, Parkinson’s disease, dementia with Lewy bodies, and frontotemporal dementia.

By analyzing these diseases in parallel, the researchers could distinguish both shared and disease‑specific “molecular fingerprints.” Across all four diseases, the protein analysis indicated clear evidence of inflammation, damage to the connections between nerve cells, and changes in the scaffolding around cells known as the extracellular matrix.

Chromosomes condense in three timed chemical waves during cell division, study shows

DNA does not float freely in the cell. Instead, it is wrapped around histone proteins to form structures called nucleosomes. These histones carry numerous chemical modifications that act as molecular signals, controlling how tightly the DNA is packaged and which genes are active. During cell division, this DNA-histone complex—known as chromatin—must be further condensed into compact, rod-shaped chromosomes. Histone modifications play a key role in this process: They change significantly during condensation and regulate the conversion of chromatin.

For the first time, researchers have precisely tracked how molecular marks on DNA proteins change during cell division—and disproved a long-held assumption in the process.

An international research team led by Professor Axel Imhof at LMU’s Biomedical Center and Professor William Earnshaw (University of Edinburgh) has analyzed these changes during cell division with unprecedented precision. To this end, the researchers developed an innovative method that synchronizes the division of cell populations. They then employed high-resolution mass spectrometry to precisely record the changes in histone modifications during cell division. The findings are published in Molecular Cell.

One-way phonon synchronization could survive noise and defects, theoretical physicists suggest

A novel approach for realizing the one-way quantum synchronization of phonons has been proposed by three theoretical physicists at RIKEN. Importantly, this method is remarkably resilient against practical challenges such as imperfections and environmental noise. Their paper, “Nonreciprocal quantum synchronization,” is published in Nature Communications.

Many devices use components that act as one-way streets, allowing particles to travel in one direction, but almost not at all in the opposite one. These so-called nonreciprocal components are widely used in microwave and light-based systems for things such as controlling signal flow and preventing reflections.

“Nonreciprocal components enable signals to travel along desired paths, whereas they are strongly attenuated in the opposite direction,” notes Franco Nori of the RIKEN Center for Quantum Computing (RQC). “This ability finds applications ranging from signal processing to invisible cloaking.”

How electron structure affects light responses in moiré materials

In materials science, if you can understand the “texture” of a material—how its internal patterns form and shift—you can begin to design how it behaves. That’s the focus of the work of Zhenglu Li, assistant professor in the Mork Family Department of Chemical Engineering and Materials Science at USC Viterbi School of Engineering. Li’s recently published paper in PNAS, titled “Moiré excitons in generalized Wigner crystals,” demonstrates that the way electrons organize themselves inside a material determines how that material responds to light—and how this organization can be engineered.

“Moiré” is a word that will be familiar to anyone who follows fashion. In the context of textiles, it refers to a larger-scale interference pattern that appears when two repeating patterns are slightly misaligned. Imagine brushing a swatch of velvet in different directions; the material reveals different properties depending on how it is ruffled.

Likewise, in the context of nanoscale materials science, an independent, shimmering or wavelike pattern is formed when two overlapping atomically thin layers are overlaid at an acute angle. The new pattern, moiré superlattice, changes how electrons move, which can give the material unusual properties.

Quantum ‘dark modes’ no longer block phonon control, opening new paths for scalable devices

Three RIKEN researchers have demonstrated a way to stop problematic “dark modes” from squelching intriguing effects in quantum systems. This advance could help with the development of more versatile quantum devices that can be used to control the storage and transmission of quantum information. The study is published in the journal Nature Communications.

Manipulations that alter the topology of certain quantum systems known as non-Hermitian systems are attracting increasing attention, since they offer novel possibilities for manipulating particles of sound (phonons) and light (photons) as well as other excitations.

“Topological operations allow for various weird and fascinating phenomena, such as the buildup of chiral phases and the movement of phonons in one direction,” notes Franco Nori of the RIKEN Center for Quantum Computing (RQC).

Newton’s 300-Year-Old Law Passes Its Biggest Cosmic Test Yet

Gravity may seem simple in everyday life. Drop an apple, and it falls. On cosmic scales, though, gravity becomes one of science’s biggest stress tests. It governs the rise of galaxies, the behavior of galaxy clusters, and the overall architecture of the universe, yet some of the universe’s motions still do not add up.

That long-running mismatch is what drove University of Pennsylvania cosmologist Patricio A. Gallardo and his collaborators to ask a basic but profound question: what if gravity itself behaves differently across the largest distances in the universe?

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