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Category: chemistry – Page 37

Fat microscopy to image lipids in cells

Lipid molecules, or fats, are crucial to all forms of life. Cells need lipids to build membranes, separate and organize biochemical reactions, store energy, and transmit information. Every cell can create thousands of different lipids, and when they are out of balance, metabolic and neurodegenerative diseases can arise. It is still not well understood how cells sort different types of lipids between cell organelles to maintain the composition of each membrane. A major reason is that lipids are difficult to study, since microscopy techniques to precisely trace their location inside cells have so far been missing.

The researchers developed a method that enables visualizing lipids in cells using standard fluorescence microscopy. After the first successful proof of concept, the authors brought mass-spectrometry expert on board to study how lipids are transported between cellular organelles.

“We started our project with synthesizing a set of minimally modified lipids that represent the main lipids present in organelle membranes. These modified lipids are essentially the same as their native counterparts, with just a few different atoms that allowed us to track them under the microscope,” explains a PhD student in the group.

The modified lipids mimic natural lipids and are “bifunctional,” which means they can be activated by UV light, causing the lipid to bind or crosslink with nearby proteins. The modified lipids were loaded in the membrane of living cells and, over time, transported into the membranes of organelles. The researchers worked with human cells in cell culture, such as bone or intestinal cells, as they are ideal for imaging.

“After the treatment with UV light, we were able to monitor the lipids with fluorescence microscopy and capture their location over time. This gave us a comprehensive picture of lipid exchange between cell membrane and organelle membranes,” concludes the author.

In order to understand the microscopy data, the team needed a custom image analysis pipeline. “To address our specific needs, I developed an image analysis pipeline with automated image segmentation assisted by artificial intelligence to quantify the lipid flow through the cellular organelle system,” says another author.

By combining the image analysis with mathematical modeling, the research team discovered that between 85% and 95% of the lipid transport between the membranes of cell organelles is organized by carrier proteins that move the lipids, rather than by vesicles. This non-vesicular transport is much more specific with regard to individual lipid species and their sorting to the different organelles in the cell. The researchers also found that the lipid transport by proteins is ten times faster than by vesicles. These results imply that the lipid compositions of organelle membranes are primarily maintained through fast, species-specific, non-vesicular lipid transport.

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New non-volatile memory platform built with covalent organic frameworks

Researchers at Institute of Science Tokyo have created a new material platform for non-volatile memories using covalent organic frameworks (COFs), which are crystalline solids with high thermal stability. The researchers successfully installed electric-field-responsive dipolar rotors into COFs.

Due to the unique structure of the COFs, the dipolar rotors can flip in response to an without being hampered by a steric hindrance from the surroundings, and their orientation can be held at ambient temperature for a long time, which are necessary conditions for non-volatile memories. The study is published in the Journal of the American Chemical Society.

Humans have made great efforts to record information by inventing recording media such as clay, paper, compact disks, and semiconductor memories. As the physical entity that holds information—such as indentations, characters, pits, or transistors—becomes smaller and its becomes higher, the information is stored with higher density. In rewritable memories, the class called “non-volatile memories” are suitable for storing data for a long time, such as for days and years.

Previously unknown RNA chaperone guides assembly of key poxvirus protein complex

A study from Würzburg reveals that pox viruses have developed a unique strategy to rapidly multiply after infecting a host cell. The findings uncover a previously unknown role for a well-known molecule and may serve as a starting point for the development of new antiviral agents.

In the English society of former times, a chaperone, traditionally an older woman, was assigned to accompany a young unmarried woman to ensure her proper behavior, especially during interactions with men, in line with the social norms of the time.

In biochemistry, chaperones also play a protective role. One of their main functions is to assist newly synthesized proteins in folding correctly and to prevent misfolded protein chains from clumping.

Deep learning method enables efficient Boltzmann distribution sampling across a continuous temperature range

A research team has developed a novel direct sampling method based on deep generative models. Their method enables efficient sampling of the Boltzmann distribution across a continuous temperature range. The findings have been published in Physical Review Letters. The team was led by Prof. Pan Ding, Associate Professor from the Departments of Physics and Chemistry, and Dr. Li Shuo-Hui, Research Assistant Professor from the Department of Physics at the Hong Kong University of Science and Technology (HKUST).

DNA-based neural network learns from examples to solve problems

Neural networks are computing systems designed to mimic both the structure and function of the human brain. Caltech researchers have been developing a neural network made out of strands of DNA instead of electronic parts that carries out computation through chemical reactions rather than digital signals.

An important property of any neural network is the ability to learn by taking in information and retaining it for future decisions. Now, researchers in the laboratory of Lulu Qian, professor of bioengineering, have created a DNA-based neural network that can learn. The work represents a first step toward demonstrating more complex learning behaviors in .

A paper describing the research appears in the journal Nature on September 3. Kevin Cherry, Ph.D., is the study’s first author.

Fabrication technique opens door to new materials for quantum hardware

Researchers have demonstrated a new fabrication approach that enables the exploration of a broader range of superconducting materials for quantum hardware.

The study, published in Applied Physics Letters, addresses a long-standing challenge: many promising superconductors, such as transition metal nitrides, carbides, and silicides, are difficult to pattern into functional devices using conventional chemistry-based methods.

By showing that physical patterning provides a viable alternative, the study paves the way to evaluate and harness these materials for high-performing quantum technologies.

No sorting needed: Plasma torch shows promise for hassle-free plastic recycling

The inconvenience of separating plastics for recycling may soon be a thing of the past. A team of Korean researchers has developed the world’s first technology that can chemically recycle mixed waste plastics into raw materials in a highly selective manner without the need for strict sorting or label removal.

The Korea Institute of Machinery and Materials (KIMM), under the National Research Council of Science & Technology (NST), announced that its Center for Plasma Process for Organic Material Recycling, carried out in collaboration with the Korea Research Institute of Chemical Technology (KRICT), Korea Institute of Industrial Technology (KITECH), Korea Institute of Science and Technology (KIST), and several universities, has successfully developed an innovative plasma conversion process.

This process transforms a wide variety of plastics directly into raw chemical feedstocks, setting a new milestone for Korea’s chemical industry and environmental policy.

Here we glow: New organic liquid provides efficient phosphorescence

The nostalgic “glow-in-the-dark” stars that twinkle on the ceilings of childhood bedrooms operate on a phenomenon called phosphorescence. Here, a material absorbs energy and later releases it in the form of light. However, recent demand for softer, phosphorescent materials has presented researchers with a unique challenge, as producing organic liquids with efficient phosphorescence at room temperature is considered difficult.

Now, researchers at the University of Osaka have attempted to tackle this problem by producing an organic liquid that phosphoresces in the ambient environment. This discovery is published in Chemical Science.

Traditional materials that can phosphoresce at contain heavy metal atoms. These phosphors are used to create the colored electronic displays we utilize every day, such as those in our smartphones. Organic materials, which contain carbon and (similar to materials found in nature), are more environmentally friendly.

Advanced model unlocks granular hydrogel mechanics for biomedical applications

Researchers at the University of Illinois Urbana-Champaign have developed a novel framework for understanding and controlling the flow behavior of granular hydrogels—a class of material made up of densely packed, microscopic gel particles with promising applications in medicine, 3D bioprinting, and tissue repair.

The new study, published in Advanced Materials, was led by chemical and biomolecular engineering professors Brendan A. Harley and Simon A. Rogers, whose research groups specialize in biomaterials engineering and rheology, respectively.

Granular hydrogels have a unique ability to mimic the of living tissue, which makes them ideal candidates for encapsulating and delivering cells directly into the body. By integrating material synthesis and characterization with rheological modeling, the researchers created a that captures the essential physics of how granular hydrogels deform—reducing a complex problem to a few controllable parameters.

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