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Archive for the ‘chemistry’ category: Page 258

Nov 23, 2020

Microfluidic Brain-on-a-Chip: Perspectives for Mimicking Neural System Disorders

Posted by in categories: biotech/medical, chemistry, computing, neuroscience

Neurodegenerative diseases (NDDs) include more than 600 types of nervous system disorders in humans that impact tens of millions of people worldwide. Estimates by the World Health Organization (WHO) suggest NDDs will increase by nearly 50% by 2030. Hence, development of advanced models for research on NDDs is needed to explore new therapeutic strategies and explore the pathogenesis of these disorders. Different approaches have been deployed in order to investigate nervous system disorders, including two-and three-dimensional (2D and 3D) cell cultures and animal models. However, these models have limitations, such as lacking cellular tension, fluid shear stress, and compression analysis; thus, studying the biochemical effects of therapeutic molecules on the biophysiological interactions of cells, tissues, and organs is problematic. The microfluidic “organ-on-a-chip” is an inexpensive and rapid analytical technology to create an effective tool for manipulation, monitoring, and assessment of cells, and investigating drug discovery, which enables the culture of various cells in a small amount of fluid (10−9 to 10−18 L). Thus, these chips have the ability to overcome the mentioned restrictions of 2D and 3D cell cultures, as well as animal models. Stem cells (SCs), particularly neural stem cells (NSCs), induced pluripotent stem cells (iPSCs), and embryonic stem cells (ESCs) have the capability to give rise to various neural system cells. Hence, microfluidic organ-on-a-chip and SCs can be used as potential research tools to study the treatment of central nervous system (CNS) and peripheral nervous system (PNS) disorders. Accordingly, in the present review, we discuss the latest progress in microfluidic brain-on-a-chip as a powerful and advanced technology that can be used in basic studies to investigate normal and abnormal functions of the nervous system.

Nov 23, 2020

Scientists observe directed energy transport between neighboring molecules in a nanomaterial

Posted by in categories: chemistry, nanotechnology, physics, solar power, sustainability

When light falls on a material, such as a green leaf or the retina, certain molecules transport energy and charge. This ultimately leads to the separation of charges and the generation of electricity. Molecular funnels, so-called conical intersections, ensure that this transport is highly efficient and directed.

An international team of physicists has now observed that such conical intersections also ensure a directed energy transport between neighboring of a nanomaterial. Theoretical simulations have confirmed the . Until now, scientists had observed this phenomenon only within one molecule. In the long term, the results could help to develop more efficient nanomaterials for organic solar cells, for example. The study, led by Antonietta De Sio, University of Oldenburg, and Thomas Frauenheim, University of Bremen, Germany, was published in the current issue of the scientific journal Nature Nanotechnology.

Photochemical processes play a major role in nature and in technology: When molecules absorb light, their electrons transit to an excited state. This transition triggers extremely fast molecular switching processes. In the human eye, for example, the molecule rhodopsin rotates in a certain way after absorbing light and thus ultimately triggers an electrical signal—the most elementary step in the visual process.

Nov 23, 2020

Chemical reactions high in Mars’ atmosphere rip apart water molecules

Posted by in categories: chemistry, space

Mars is so dry because its water constant escapes into space. A new study suggests this process occurs in the ionosphere and faster than thought.

Nov 20, 2020

Getting it just right: The Goldilocks model of cancer

Posted by in categories: biotech/medical, chemistry, genetics, life extension

Senescence in cancer cells

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Sometimes, too much of a good thing can turn out to be bad. This is certainly the case for the excessive cell growth found in cancer. But when cancers try to grow too fast, this excessive speed can cause a type of cellular aging that actually results in arrested growth. Scientists at Duke-NUS Medical School have now discovered that a well-known signaling pathway helps cancers grow by blocking the pro-growth signals from a second major cancer pathway.

Continue reading “Getting it just right: The Goldilocks model of cancer” »

Nov 19, 2020

Dipole Drive for space propulsion | Robert Zubrin at Breakthrough Discuss 2018

Posted by in categories: chemistry, space travel

Circa 2018


The speed of space travel is currently limited by the quantity of chemical fuel that spacecraft must carry. Robert Zubrin, President of Pioneer Astronautics, introduces the dipole drive — a new propulsion system which uses ambient space plasma as propellant, thereby avoiding the need to carry its own.

Nov 19, 2020

Near-infrared probe decodes telomere dynamics

Posted by in categories: biotech/medical, chemistry, life extension

A new synthetic probe offers a safe and straightforward approach for visualizing chromosome tips in living cells. The probe was designed by scientists at the Institute for Integrated Cell-Material Science (iCeMS) and colleagues at Kyoto University, and could advance research into aging and a wide range of diseases, including cancers. The details were published in the Journal of the American Chemical Society.

“Chromosome ends are constantly at risk of degradation and fusion, so they are protected by structures called telomeres, which are made of long repeating DNA sequences and bound proteins,” says iCeMS chemical biologist Hiroshi Sugiyama, who led the study. “If telomeres malfunction, they are unable to maintain chromosome stability, which can lead to diseases such as cancer. Also, telomeres normally shorten with each cell division until they reach their limit, causing cell death.”

Visualizing telomeres, especially their physical arrangements in , is important for understanding their relevance to disease and aging. Several visualization approaches already exist, but they have disadvantages. For example, some can only observe telomeres in preserved, or fixed, cells. Others are time-consuming or involve harsh treatments that denature DNA.

Nov 18, 2020

Synthetic biology crucial to human missions to Mars

Posted by in categories: bioengineering, biological, chemistry, genetics, space travel

In Project Apollo, life support was based on carrying pretty much everything that astronauts needed from launch to splashdown. That meant all of the food, air, and fuel. Fuel in particular took up most of the mass that was launched. The enormous three-stage Saturn-V rocket was basically a gigantic container for fuel, and even the Apollo spacecraft that the Saturn carried into space was mostly fuel, because fuel was needed also to return from the Moon. If NASA’s new Orion spacecraft takes astronauts back to the Moon, they’ll also use massive amounts of fuel going back and forth; and the same is true if they journey to a near-Earth asteroid. However, once a lunar base is set up, astronauts will be able use microorganisms carried from Earth to process lunar rock into fuel, along with oxygen. The latter is needed not just for breathing, but also in rocket engines where it mixes with the fuel.

Currently, there are microorganisms available naturally that draw energy from rock and in the process release chemical products that can be used as fuel. However, as with agricultural plants like corn and soy, modifying such organisms can potentially make a biologically-based lunar rock processing much more efficient. Synthetic biology refers to engineering organisms to pump out specific products under specific conditions. For spaceflight applications, organisms can be engineered specifically to live on the Moon, or for that matter on an asteroid, or on Mars, and to synthesize the consumables that humans will need in those environments.

In the case of Mars, a major resource that can be processed by synthetic biology is the atmosphere. While the Martian air is extremely thin, it can be concentrated in a biological reactor. The principal component of the Martian air is carbon dioxide, which can be turned into oxygen, food, and rocket fuel by a variety of organisms that are native to Earth. As with the Moon rocks, however, genetic techniques can make targeted changes to organisms’ capabilities to allow them to do more than simply survive on Mars. They could be made to thrive there.

Nov 18, 2020

‘Weird’ Molecule Detected on Titan Has Never Been Found in Any Atmosphere

Posted by in categories: chemistry, space

Titan, the already pretty weird moon of Saturn, just got a little bit weirder. Astronomers have detected cyclopropenylidene (C3H2) in its atmosphere — an extremely rare carbon-based molecule that’s so reactive, it can only exist on Earth in laboratory conditions.

In fact, it’s so rare that it has never before been detected in an atmosphere, in the Solar System or elsewhere. The only other place it can remain stable is the cold void of interstellar space. But it may be a building block for more complex organic molecules that could one day lead to life.

“We think of Titan as a real-life laboratory where we can see similar chemistry to that of ancient Earth when life was taking hold here,” said astrobiologist Melissa Trainer of NASA’s Goddard Space Flight Center, one of the chief scientists set to investigate the moon in the upcoming Dragonfly mission launching in 2027.

Nov 17, 2020

Novel analytic approach enhances nuclear magnetic resonance signal detection in previously ‘invisible’ regions

Posted by in categories: biotech/medical, chemistry, nuclear energy

First introduced into wide use in the middle of the 20th century, nuclear magnetic resonance (NMR) has since become an indispensable technique for examining materials down to their atoms, revealing molecular structure and other details without interfering with the material itself.

“It’s a broadly used technique in , materials characterization, MRI—situations in which you do a non-invasive analysis, but with atomic and molecular details,” said UC Santa Barbara chemistry professor Songi Han. By placing a sample in a strong magnetic field and then probing it with radio waves scientists can determine from the response from the oscillating nuclei in the material’s atoms the of the material.

“However, the problem with NMR has been that because it’s such a low-energy technique, it’s not very sensitive,” Han said. “It’s very detailed, but you don’t get much signal.” As a result, large amounts of sample material may be needed relative to other techniques, and the signals’ general weakness makes NMR less than ideal for studying complex chemical processes.

Nov 16, 2020

China’s silicon rush: A reality check

Posted by in categories: chemistry, computing

China faces an additional geopolitical challenge in chip fabrication and assembly. Just a handful of Japanese companies dominate the global market in silicon wafers, photoresists, and essential packaging chemicals. These companies are well-regarded for their high-quality production capabilities and their products are not easily replaceable even by a manufacturing heavyweight such as China. In a changing world where strategic concerns are guiding technology flows, China’s chip ambitions can be foiled not just by the US but also by Japan and Taiwan.


China’s state-backed funds may well spur private investment, even producing a few champions, but are unlikely to result in a self-sufficient Chinese chip industry any time soon.