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Archive for the ‘chemistry’ category: Page 318

Feb 8, 2017

Decreased expression of STING predicts poor prognosis in patients with gastric cancer

Posted by in categories: biotech/medical, chemistry, food

Interesting read on recent Gastric Cancer research. I do a lot of work with the National Esophageal Cancer (EC) Awareness Association; I can tell you that this disease is truly a killer as gastric related cancers are horrible to detect early enough and have a horrible record of reoccurring. Survival rates are some of the worst and today the rates of EC have skyrocketed especially in the younger age groups such as 25 to 35 year olds.

When you work for these foundations, read the stories from patients and their families looking for answers and help with everything from help on what types of food can their love eat and hopefully keep down for nutrition, to how can they get help with transportation to simply go to work or the doctor as meds restrictions on driving, to knowing the end is near and how to prepare, etc. The worst ones are the 27 to 36 yr old fathers and mothers whose love one is saying good bye to the person they married only recently married the year before or spent 7 years with. This is why I work for my foundations as every small step does in the end create a larger impact in the end and hopefully helps us finally beat this disease.


STING (stimulator of interferon genes) has recently been found to play an important role in host defenses against virus and intracellular bacteria via the regulation of type-I IFN signaling and innate immunity. Chronic infection with Helicobacter pylori is identified as the strongest risk factor for gastric cancer. Thus, we aim to explore the function of STING signaling in the development of gastric cancer. Immunohistochemistry was used to detect STING expression in 217 gastric cancer patients who underwent surgical resection. STING protein expression was remarkably decreased in tumor tissues compared to non-tumor tissues, and low STING staining intensity was positively correlated with tumor size, tumor invasion depth, lymph mode metastasis, TNM stage, and reduced patients’ survival. Multivariate analysis identified STING as an independent prognostic factor, which could improve the predictive accuracy for overall survival when incorporated into TNM staging system. In vitro studies revealed that knock-down of STING promoted colony formation, viability, migration and invasion of gastric cancer cells, and also led to a defect in cytosolic DNA sensing. Besides, chronic H. pylori infection up-regulated STING expression and activated STING signaling in mice. In conclusion, STING was proposed as a novel independent prognostic factor and potential immunotherapeutic target for gastric cancer.

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Feb 7, 2017

Determining the Photoisomerization Quantum Yield of Photoswitchable Molecules in Solution and in the Solid State

Posted by in categories: biological, chemistry, quantum physics

Photoswitchable molecules are able to isomerize between two metastable forms through light stimuli. Originally being studied by photochemists, this type of molecule has now found a wide range of applications within physics, chemistry and biology. The extensive usage of photochromic molecules is due to the two isomers having fundamentally different physical and chemical properties. The most important attribute of a photoswitch is the photoisomerization quantum yield, which defines the efficiency of the photoisomerization event. Here we show how to determine the photoisomerization quantum yield in the solid state and in solution when taking thermal processes into account. The described method together with provided software allows for rapid and accurate determination of the isomerization process for this important class of molecules.

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Feb 3, 2017

Neutrons reveal ‘quantum tunnelling’ on graphene enables the birth of stars

Posted by in categories: chemistry, nanotechnology, particle physics, quantum physics, space travel

Graphene is known as the world’s thinnest material due to its 2-D structure, in which each sheet is only one carbon atom thick, allowing each atom to engage in a chemical reaction from two sides. Graphene flakes can have a very large proportion of edge atoms, all of which have a particular chemical reactivity. In addition, chemically active voids created by missing atoms are a surface defect of graphene sheets. These structural defects and edges play a vital role in carbon chemistry and physics, as they alter the chemical reactivity of graphene. In fact, chemical reactions have repeatedly been shown to be favoured at these defect sites.

Interstellar molecular clouds are predominantly composed of hydrogen in molecular form (H2), but also contain a small percentage of dust particles mostly in the form of carbon nanostructures, called polyaromatic hydrocarbons (PAH). These clouds are often referred to as ‘star nurseries’ as their low temperature and high density allows gravity to locally condense matter in such a way that it initiates H fusion, the nuclear reaction at the heart of each star. Graphene-based materials, prepared from the exfoliation of graphite oxide, are used as a model of interstellar carbon dust as they contain a relatively large amount of , either at their edges or on their surface. These defects are thought to sustain the Eley-Rideal chemical reaction, which recombines two H into one H2 molecule.

The observation of interstellar clouds in inhospitable regions of space, including in the direct proximity of giant stars, poses the question of the origin of the stability of hydrogen in the molecular form (H2). This question stands because the clouds are constantly being washed out by intense radiation, hence cracking the hydrogen molecules into atoms. Astrochemists suggest that the chemical mechanism responsible for the recombination of atomic H into molecular H2 is catalysed by carbon flakes in interstellar clouds. Their theories are challenged by the need for a very efficient surface chemistry scenario to explain the observed equilibrium between dissociation and recombination. They had to introduce highly reactive sites into their models so that the capture of an atomic H nearby occurs without fail.

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Feb 1, 2017

Missouri S&T researcher works to develop nanodiamond materials

Posted by in categories: biotech/medical, chemistry, military, nanotechnology, particle physics

Nice.


When you think of diamonds, rings and anniversaries generally come to mind. But one day, the first thing that will come to mind may be bone surgery. By carefully designing modified diamonds at the nano-scale level, a Missouri University of Science and Technology researcher hopes to create multifunctional diamond-based materials for applications ranging from advanced composites to drug delivery platforms and biomedical imaging agents.

Dr. Vadym Mochalin, an associate professor of chemistry and materials science and engineering at Missouri S&T, is characterizing and modifying 5-nanometer nanodiamond particles produced from expired military grade explosives so that they can be developed to perform specific tasks. His current research studies their use as a filler in various types of composites.

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Jan 19, 2017

Will synthetic biology help us to eliminate age-related diseases?

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

A quick look at synthetic biology and its potential for health and treating age-related diseases.


All living organisms contain an instruction set that determines what they look like and what they do. These instructions are encoded in the organism’s DNA within every cell, this is an organism’s genetic code (or “genome”).

Mankind has been altering the genetic code of plants and animals for thousands of years, by selectively breeding individuals with desired features. Over time we have become experts at viewing and manipulating this code, and we can now take genetic information associated with the desired features from one organism, and add it into another one. This is the basis of genetic engineering, which has allowed us to speed up the process of developing new breeds of plants and animals.

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Jan 17, 2017

Messy Chemistry, Evolving Rocks, and the Origin of Life

Posted by in categories: chemistry, evolution

Noted synthetic life researcher Steven Benner of Foundation for Applied Molecular Evolution is fond of pointing out that gooey tars are the end product of too many experiments in his field. His widely-held view is that the tars, made out of chemicals known to be important in the origin of life, are nonetheless a dead end to be avoided when trying to work out how life began.

But in the changing world of origins of life research, others are asking whether those messy tars might not be a breeding ground for the origin of life, rather than an obstacle to it.

One of those is chemist and astrobiologist Irena Mamajanov of the Earth-Life Science Institute (ELSI) in Tokyo. As she recently explained during an institute symposium, scientists know that tar-like substances were present on early Earth, and that she and her colleagues are now aggressively studying their potential role in the prebiotic chemical transformations that ultimately allowed life to emerge out of non-life.

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Jan 13, 2017

Making hydrogen from wax

Posted by in categories: chemistry, energy, transportation

This publication suggests that wax could be carried on vehicles and used to create hydrogen gas in situ, the waste carbon being used to make more wax via syngas production and the Fischer-Tropsch process, where carbon monoxide and hydrogen is converted into hydrocarbons as a potential source of petro-chemicals that does not involve releasing fossil carbon into the atmosphere. While this publication is still a long way from a working industrial-scale process, it offers a very hopeful potential avenue for less-polluting technology.


Philip recently attended an event for other Oxford University chemistry alumni, and one of the speakers drew attention to a recent publication from, among others, Oxford chemists, regarding the production of hydrogen from paraffin waxes by microwave degradation using a ruthenium catalyst.

Hydrogen has often been suggested as an environmentally-friendly replacement energy source for fossil fuels in transport vehicles and other applications requiring high energy density. (Note that hydrogen is not a “fuel”, as it must be made using energy from other sources, which can be environmentally-friendly or not.) However, there are significant problems with this, notably involving the safe storage of a highly-inflammable and explosive gas which is much lighter than air.

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Jan 13, 2017

Forget What You Learned in High School

Posted by in categories: chemistry, education

It’s the stuff of Chemistry 101: carbon can only form four bonds because it only has four shareable electrons.

But this rule no longer applies, because scientists have confirmed the existence of an exotic carbon molecule that can form six bonds, meaning the most classic example of tetravalence in our high school chemistry textbooks now comes with a hefty caveat.

If all of this is kinda giving you conniptions, we’re right there with you.

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Jan 5, 2017

Nano-chimneys can cool circuits

Posted by in categories: chemistry, nanotechnology

Very cool.


A few nanoscale adjustments may be all that is required to make graphene-nanotube junctions excel at transferring heat, according to Rice University scientists.

The Rice lab of theoretical physicist Boris Yakobson found that putting a cone-like “chimney” between the graphene and nanotube all but eliminates a barrier that blocks heat from escaping.

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Dec 15, 2016

New structure shows how cells assemble protein-making machinery

Posted by in categories: chemistry, nanotechnology, particle physics, robotics/AI

Scientists at The Rockefeller University have created the most detailed three-dimensional images to date of an important step in the process by which cells make the nano-machines responsible for producing all-important protein. The results, described December 15 in Science, are prompting the researchers to re-evaluate how they envision this early phase in the construction of ribosomes.

“The structure they determined, shown above, belongs to a particle formally called the “small subunit processome.” Before this particle can fulfill its destiny to become the smaller half of a complete ribosome, the RNA within it needs to be folded, tweaked, and cut.

“Initially, we thought of the small subunit processome as a product on an assembly line, with molecular workers arriving from outside, much like the robots that would put together a car. But that analogy no longer appears apt,” says senior author Sebastian Klinge, head of the Laboratory of Protein and Nucleic Acid Chemistry.

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