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The short curing time and consequently quick healing process is advantageous for these self-healing structures with embedded healing agent reservoirs compared to many other previously reported self-healing materials. For instance, self-healing materials with microvascular networks reported by Toohey et al.18 needed to be kept at room temperature for a period of 12 hours in order to become healed. Self-healing materials with interpenetrating microvascular networks reported by Hansen et al.32 had to go under cyclic bending (50 cycles at 100 μ m displacement) to enhance the mixing of the healing agents at the location of the crack, and after that required to be subjected to 48 hours of curing at 30 °C.

Various mechanical tests were conducted to investigate the healing capability of the structures. For each test, three identical samples with an overall dimension of 5 × 10 × 77 mm (H × W × L) were printed using a top-down SLA-based 3D printer. A notch with equal width and depth of 200 µm was incorporated in the middle of the CAD (computer aided design) model of two out of three specimens (Fig. 1a). This notch enhances the repeatability of the experiments and encourages the initiation of a straight crack under flexural (3-point bending) tests32. When a crack forms, propagates, and reaches the reservoir, the resin wicks into the crack planes as a result of capillary forces and closes the crack when it becomes cured under exposure to UV light. These forces are not high enough to drain out and deplete the large amount of healing agent in the reservoirs. The agent’s relatively high viscosity, approximately 850‑1000 cps at 25 °C, further aids in limiting its flow out of the damaged area. After healing, the specimen is tested again, and a new crack is formed under a new critical load and the aforementioned process is repeated. The small amount of leaked healing agent in the self-healing samples becomes cured relatively quickly under the UV radiation with a wavelength of 405 nm. A UV-light source was employed to cure the leaked-healing agent for 3 min. at 50 °C. To compare the effectiveness of the capillary forces for filling the crack, the notch of the second sample was manually filled before the tests. The last unnotched specimen (virgin) remained unfilled and was tested to provide a reference. It is worth noting that for simplicity’s sake, the structures were placed into a UV oven for curing; however, other types of UV sources can initiate and complete the healing process. In the case of a difficult to access part, on-site repair can be easily implemented using a remote UV source. Additionally, unloading the structure is not necessary to the healing process. A damaged structure is able to cure under loading as the healing mechanism is not affected.

The samples underwent tensile tests following the ASTM D638 standard and their force-displacement curves were recorded at a constant crosshead speed of 13 mm min−1. Figure 2 shows the force-displacement curves for each specimen type. There was a difference of 22% between the tensile fracture load of the virgin specimen without a notch and the sample that was manually repaired. By comparing the fracture force of the healed sample before and after healing (182 N for Capillary – Cycle 1 and 199 N for Capillary – Cycle 2), it can be seen that the fracture force increases by around 17 N after the sample was repaired. There is a significant difference between the fracture force of the manually repaired sample and the sample after healing (Capillary – Cycle 2). This indicates that the self-healing process is effective and is reviving the original mechanical performance of the structure.

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No matter the price tag, the industry also has to convince consumers it’s worth their time to upgrade to new technologies.

“It’s difficult to get homeowners to change from the technology that they’re used to, especially in staid devices like water heaters, because they think of it as a utility: open the faucet, water comes out,” Callahan told Freethink. “There’s an education process to get them to understand that there’s a better, cheaper, faster, cooler way to [heat water].”

Tankless systems like the Model 3 aren’t the only new instant hot water-heating technologies aiming to reshape the industry. Solar-powered water heaters can reduce your utility bill by 50 to 80%, according to the U.S. Energy Department. Heat pump water heaters — which extract heat from the air, store it in tanks, and use it to heat water — are estimated to be at least twice as efficient as conventional systems, partly because they can store midday heat and use it later that night.

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“We then go on to show that dopamine is not a reward molecule at all. It instead helps encode information about all types of important and relevant events and drive adaptive behavior—regardless of whether it is positive or negative.”

Summary: A new study finds dopamine increases responses to stressful stimuli, not just pleasurable ones. The findings could have implications for the treatment of mental health disorders and addiction.

Source: Vanderbilt University

Pioneering research shows that dopamine levels increase in response to stressful stimuli, and not just pleasurable ones, potentially rewriting facts about the “feel-good” hormone—a critical mediator of many psychiatric diseases. This discovery is cause to rethink treatment for psychiatric disease and addiction.

This research was led by Erin Calipari, assistant professor of pharmacology, and Munir Gunes Kutlu, a postdoctoral fellow in Calipari’s laboratory.

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Kathy Patten, a grandmother from Baltimore, suffered a heart attack and spent 45 long minutes clinically dead. But some intense CPR actually managed to bring her back to life, giving her a second chance that local news stations are calling a “medical miracle.”

Patten has reportedly made an almost full recovery, something that is exceedingly rare. While TV dramas give the impression that CPR is often successful, the reality is grim. Only around 10.6 percent of those who experience cardiac arrest are later discharged from the hospital, according to a 2018 study, though those numbers fluctuate depending the severity and timing of the incident.

“I’m so grateful God gave me a second chance,” Patten told CBS affiliate WJZ-TV. “I’m just going to be the best person I can be. It’s very scary, coming back is a second chance of life.”

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Hey it’s Han from WrySci HX talking about a really interesting concept — the world’s first biological gaming console that uses nanopore technology to detect molecules, and turn these readouts into games! It’s called the Demonpore 64! More below ↓↓↓

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Analysis of unique fingerprints in light emitted from material surrounding young stars has revealed “significant reservoirs” of large organic molecules necessary to form the basis of life, say researchers.

Dr. John Ilee, Research Fellow at the University of Leeds who led the study, says the findings suggest that the basic chemical conditions that resulted in life on Earth could exist more widely across the Galaxy.

The large organic molecules were identified in protoplanetary disks circling newly formed stars. A similar disk would have once surrounded the young Sun, forming the planets that now make up our Solar System. The presence of the molecules is significant because they are “stepping-stones” between simpler carbon-based molecules such as carbon monoxide, found in abundance in space, and more complex molecules that are required to create and sustain life.

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Reinforcement learning is an interesting area of machine learning (ML) that has advanced rapidly in recent years. AlphaGo is one such RL-based computer program that has defeated a professional human Go player, a breakthrough that experts feel was a decade ahead of its time.

Reinforcement learning differs from supervised learning because it does not need the labelled input/output pairings for training or the explicit correction of sub-optimal actions. Instead, it investigates how intelligent agents should behave in a particular situation to maximize the concept of cumulative reward.

This is a huge plus when working with real-world applications that don’t come with a tonne of highly curated observations. Furthermore, when confronted with a new circumstance, RL agents can acquire methods that allow them to behave even in an unclear and changing environment, relying on their best estimates at the proper action.

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That fossil wasn’t enough to confirm Africa as our homeland. Since that discovery, paleoanthropologists have amassed many thousands of fossils, and the evidence over and over again has pointed to Africa as our place of origin. Genetic studies reinforce that story. African apes are indeed our closest living relatives, with chimpanzees more closely related to us than to gorillas. In fact, many scientists now include great apes in the hominid family, using the narrower term “hominin” to refer to humans and our extinct cousins.

In a field with a reputation for bitter feuds and rivalries, the notion of humankind’s African origins unifies human evolution researchers. “I think everybody agrees and understands that Africa was very pivotal in the evolution of our species,” says Charles Musiba, a paleoanthropologist at the University of Colorado Denver.

Paleoanthropologists have sketched a rough timeline of how that evolution played out. Sometime between 9 million and 6 million years ago, the first hominins evolved. Walking upright on two legs distinguished our ancestors from other apes; our ancestors also had smaller canine teeth, perhaps a sign of less aggression and a change in social interactions. Between about 3.5 million and 3 million years ago, humankind’s forerunners ventured beyond wooded areas. Africa was growing drier, and grasslands spread across the continent. Hominins were also crafting stone tools by this time. The human genus, Homo, arrived between 2.5 million and 2 million years ago, maybe earlier, with larger brains than their predecessors. By at least 2 million years ago, Homo members started traveling from Africa to Eurasia. By about 300,000 years ago, Homo sapiens, our species, emerged.

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