It Seems NuCLEARer Now

It seems nuCLEARer now

The Sun’s Energy Doesn’t Come From Fusing Hydrogen Into Helium (Mostly)

The Sun’s Energy Doesn’t Come From Fusing Hydrogen Into Helium (Mostly)

“It might surprise you to learn that hydrogen-fusing-into-helium makes up less than half of all nuclear reactions in our Sun, and that it’s also responsible for less than half of the energy that the Sun eventually outputs. There are strange, unearthly phenomena along the way: the diproton that usually just decays back to the original protons that made it, positrons spontaneously emitted from unstable nuclei, and in a small (but important) percentage of these reactions, a rare mass-8 nucleus, something you’ll never find naturally occurring here on Earth. But that’s the nuclear physics of where the Sun gets its energy from, and it’s so much richer than the simple fusion of hydrogen into helium!”

Ask anyone where the Sun (or any star) gets its energy from, and most people will correctly answer “nuclear fusion.” But if you ask what’s getting fused, most people – including most scientists – will tell you that the Sun fuses hydrogen into helium, and that’s what powers it. It’s true that the Sun uses hydrogen as its initial fuel, and that helium-4 is indeed the end product, but the individual reactions that take place to turn hydrogen into helium are surprisingly diverse and intricate. There are actually four major reactions that take place in the sun: fusing two protons into deuterium, fusing deuterium and a proton into helium-3, fusing two helium-3 nuclei into helium-4, and fusing helium-3 and helium-4 in a chain reaction to produce two helium-4 nuclei. Note that only one of those reactions actually turns hydrogen into helium, and that’s not what makes up either the majority of reactions or the majority of the Sun’s energy!

The Sun fuses hydrogen into helium, but that’s not the only thing that powers it. Come find out how the Sun really works today!

LISTEN UP YALL

scientists are saying we have about three years before all climate change effects are completely irreversible (meaning we are absolutely FUCKED). that’s just to avoid the worst of it (yes, all this shit with the fires and hurricanes is NOT the worst of it). so, i made a quick list of things people can do to start reducing their energy use and in turn, reducing greenhouse gas emissions and what not! -line/hang dry clothing - dryers use so much energy as it is and switching to the actually makes your clothing last so much longer! aka less energy spent on manufacturing and shipping clothing. -eat less meat - when i say this, it’s not specifically for the save the animals idea, but that is a huge bonus! factories that slaughter, process, and package meat use an insane amount of energy (another reason to switch to local as much as possible!!) -use less hot water - wash clothes in cold water, take shorter showers (or cold ones if you can handle that) -switch to reusable grocery bags -efficient light bulbs -carpool, walk, ride a bike, public transit -unplug electronics not in use - don’t leave things charging for too long. unplug your tv when it’s not being used. 40% of an item’s energy use is spent when it’s on standby!! -buy only what you need (look into minimalism guys, it’s real neat and saves money) -recycle -get a reusable water bottle instead of buying cases of plastic bottles - i bought one at walmart for 98 cents and i use it every single day. -plant your own garden or start a community garden! -composting -maintain air in car tires for better gas mileage -drive instead of taking airplanes -buy used items if they’re in good condition - why spend $20 on a shirt that you can find at goodwill for $1? same goes for books, CDs, and pretty much anything! save money AND cut down on energy use! -yall know that saying “reduce, reuse, recycle” -most importantly: TALK TO PEOPLE ABOUT THIS ISSUE - i mean your friends, your family, your local government, everyone!! these are all small things and it’s just a start but if we can get everyone in on habits like these, we could reduce the population’s carbon footprint by SO MUCH! we don’t wanna end up like that movie wall-e guys. this is serious!!

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redplanet44

7 years ago

New process allows 3-D printing of nanoscale metal structures

Synthesizing organic scaffolds that contain metal ions enables 3-D printing of metallic structures that are orders of magnitude smaller than previously possible

For the first time, it is possible to create complex nanoscale metal structures using 3-D printing, thanks to a new technique developed at Caltech.

The process, once scaled up, could be used in a wide variety of applications, from building tiny medical implants to creating 3-D logic circuits on computer chips to engineering ultralightweight aircraft components. It also opens the door to the creation of a new class of materials with unusual properties that are based on their internal structure. The technique is described in a study that will be published in Nature Communications on February 9.

In 3-D printing – also known as additive manufacturing – an object is built layer by layer, allowing for the creation of structures that would be impossible to manufacture by conventional subtractive methods such as etching or milling. Caltech materials scientist Julia Greer is a pioneer in the creation of ultratiny 3-D architectures built via additive manufacturing. For instance, she and her team have built 3-D lattices whose beams are just nanometers across – far too small to be seen with the naked eye. These materials exhibit unusual, often surprising properties; Greer’s team has created exceptionally lightweight ceramics that spring back to their original shape, spongelike, after being compressed.

Greer’s group 3-D prints structures out of a variety of materials, from ceramics to organic compounds. Metals, however, have been difficult to print, especially when trying to create structures with dimensions smaller than around 50 microns, or about half the width of a human hair.

Skin gel allows wounds to heal without leaving a scar

A team of researchers at Huazhong University of Science and Technology has developed a silk protein-based gel that they claim allows for skin healing without scarring. In their paper published in the journal Biomaterials Science, the group describes their gel and how well it works.

Scarring due to a skin injury is not just unsightly—for many, it can also be a painful reminder of a wound. For these reasons, scientists have sought a way to heal wounds without scarring. In this new effort, the team in China claims to have found such a solution—a sericin hydrogel.

The gel used by the researchers was based on a silk protein—the researchers extracted sericin from silk fibers and then used a UV light and a photoinitiator to cross-link the protein chains. The result was a gel that adhered well to cells and did not trigger much of an immune response. The researchers note that it also has adjustable mechanical properties. They explain that the gel allows for scar-free healing by inhibiting inflammation and by promoting the development of new blood vessels. It was also found to regulate TGF-β growth factors, which resulted in stem cells being routed to the injury site allowing new skin to develop, rather than scar tissue.

Researchers Find New DNA Structure in Living Human Cells

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Your daily selection of the latest science news!

According to Breaking Science News

A team of scientists from the Garvan Institute of Medical Research and the Universities of New South Wales and Sydney has identified a new DNA structure — called the intercalated motif (i-motif) — inside living human cells.

Deep inside the cells in our body lies our DNA. The information in the DNA code — all 6 billion A, C, G and T letters — provides precise instructions for how our bodies are built, and how they work.

The iconic ‘double helix’ shape of DNA has captured the public imagination since 1953, when James Watson and Francis Crick famously uncovered the structure of DNA.

However, it’s now known that short stretches of DNA can exist in other shapes, in the laboratory at least — and scientists suspect that these different shapes might play an important role in how and when the DNA code is ‘read.’

“When most of us think of DNA, we think of the double helix. This research reminds us that totally different DNA structures exist — and could well be important for our cells,” said co-lead author Dr. Daniel Christ, from the Kinghorn Centre for Clinical Genomics at the Garvan Institute of Medical Research and St Vincent’s Clinical School at the University of New South Wales.

“The i-motif is a four-stranded ‘knot’ of DNA,” added co-lead author Dr. Marcel Dinger, also from the Garvan Institute of Medical Research and the University of New South Wales.

“In the knot structure, C letters on the same strand of DNA bind to each other — so this is very different from a double helix, where ‘letters’ on opposite strands recognize each other, and where Cs bind to Gs [guanines].”

Although researchers have seen the i-motif before and have studied it in detail, it has only been witnessed in vitro — that is, under artificial conditions in the laboratory, and not inside cells. In fact, they have debated whether i-motif DNA structures would exist at all inside living things — a question that is resolved by the new findings.

To detect the i-motifs inside cells, Dr. Christ, Dr. Dinger and their colleagues developed a precise new tool — a fragment of an antibody molecule — that could specifically recognize and attach to i-motifs with a very high affinity.

Until now, the lack of an antibody that is specific for i-motifs has severely hampered the understanding of their role.

Crucially, the antibody fragment didn’t detect DNA in helical form, nor did it recognize ‘G-quadruplex structures’ (a structurally similar four-stranded DNA arrangement).

With the new tool, the team uncovered the location of ‘i-motifs’ in a range of human cell lines.

Using fluorescence techniques to pinpoint where the i-motifs were located, the study authors identified numerous spots of green within the nucleus, which indicate the position of i-motifs.

The scientists showed that i-motifs mostly form at a particular point in the cell’s ‘life cycle’ — the late G1 phase, when DNA is being actively ‘read.’

They also showed that i-motifs appear in some promoter regions — areas of DNA that control whether genes are switched on or off — and in telomeres, ‘end sections’ of chromosomes that are important in the aging process.

“We think the coming and going of the i-motifs is a clue to what they do. It seems likely that they are there to help switch genes on or off, and to affect whether a gene is actively read or not,” said study first author Dr. Mahdi Zeraati, also from the Garvan Institute of Medical Research and the University of New South Wales.

“We also think the transient nature of the i-motifs explains why they have been so very difficult to track down in cells until now,” Dr. Christ added.

“It’s exciting to uncover a whole new form of DNA in cells — and these findings will set the stage for a whole new push to understand what this new DNA shape is really for, and whether it will impact on health and disease,” Dr. Dinger said.

The team’s results appear in the journal Nature Chemistry.