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venerdì 30 ottobre 2020

# gst: stitch together at both ends to selective formation of classes of bicyclic medium-sized ring compounds

AA << have discovered catalyst-controlled divergent reactions to synthesize three different classes of medium-sized bicyclic compounds from the same starting materials  >>

<< Intermolecular higher-order cycloaddition, in which two starting materials are 'stitched' together at both ends, provides great potential to build complex cyclic compounds from simple building blocks. Unfortunately, such transformations to prepare medium-sized rings are often plagued with competitive reaction pathways and low levels of site- and stereo-selectivity >>

<< The most significant aspect of this chemistry was that not one, but three different classes of bicyclic medium-sized ring compounds were obtained with high efficiency and stereo-selectivity from the same set of starting molecules.  >>

Divergent synthesis of bicyclic medium-sized ring structures. National University of Singapore. Oct 26, 2020.


Li-Cheng Yang, Ya-Nong Wang, et al. Stereoselective access to [5.5.0] and [4.4.1] bicyclic compounds through Pd-catalysed divergent higher-order cycloadditions. Nat. Chem. 12, 860–868. doi: 10.1038/ s41557-020-0503-7. July 27, 2020. 





giovedì 29 ottobre 2020

# life: aprops of 1or2 achoo! from Wuhan (SARS-CoV-2), a mask build of 'nanofibers randomly land on a collector to create a sort of non-woven mesh'

<< Recently, students from BYU’s College of Engineering teamed up with Nanos Foundation to develop a nanofiber membrane that can be sandwiched between the cloth pieces in a homemade mask. While today’s typical cloth mask might block fewer than 50% of virus particles, the membrane — which can be made using simple, inexpensive materials — will be able to block 90 to 99% of particles, increasing effectiveness while preserving breathability. The membranes are made through a process called “electrospinning,” which involves dissolving a polymer plastic in a solution and then using an electrical current to move a droplet of the polymer downward through a needle. As the droplet accelerates, it stretches into a very small fiber that retains a static charge. >>

<< Those nanofibers randomly land on a collector to create a sort of non-woven mesh, >> Katie Varela.

Christie Allen. With innovative nanofiber membranes, cloth masks’  efficacy goes up to 99%. Oct 21, 2020.



Also

keyword 'virus' in FonT


keyword 'virus' in Notes (quasi-stochastic poetry):




mercoledì 28 ottobre 2020

# astro: the effect of Yarkovsky acceleration to direct the asteroid Apophis (towards us, hypothetically)

<< A University of Hawai Institute for Astronomy (IfA) astronomer has revealed critical new findings linked to a large asteroid expected to pass extremely close to Earth. Dave Tholen and collaborators have announced the detection of Yarkovsky acceleration on the near-Earth asteroid Apophis. This acceleration arises from an extremely weak force on an object due to non-uniform thermal radiation. This force is particularly important for the asteroid Apophis, as it affects the probability of an Earth impact in 2068. >>

Massive asteroid subject of new findings. Oct 26, 2020. 


"2068" –Massive Asteroid Apophis on Path for Earth Impact. Oct 27, 2020.


Also

il ciottolo Apophis. Notes. May 05, 2006 (quasi-stochastic poetry). 


A wicked list in the dino-killing range; waiting for new entries. FonT. Jun 29, 2017. 



A few hints of our presence. Notes. Oct 13, 2006 (quasi-stochastic poetry)





martedì 27 ottobre 2020

# life: deliver care remotely; can we trust AI Doctors?

<< Machine learning is taking medical diagnosis by storm. From eye disease, breast and other cancers, to more amorphous neurological disorders, AI is routinely matching physician performance, if not beating them outright.  Yet how much can we take those results at face value? When it comes to life and death decisions, when can we put our full trust in enigmatic algorithms—“black boxes” that even their creators cannot fully explain or understand? The problem gets more complex as medical AI crosses multiple disciplines and developers, including both academic and industry powerhouses such as Google, Amazon, or Apple, with disparate incentives. >>

<< This week, the two sides battled it out in a heated duel in one of the most prestigious science journals, Nature. >>

Shelly Fan. Can We Trust AI Doctors? Google Health and Academics Battle It Out. Oct 20, 2020. 


Benjamin Haibe-Kains, George Alexandru Adam, et al. Transparency and reproducibility in artificial intelligence. Nature 586, E14–E16.  doi: 10.1038/ s41586-020-2766-y. Oct 15, 2020


Emre Sezgin, Yungui Huang, et al. Readiness for voice assistants to support healthcare delivery during a health crisis and pandemic. npj Digit. Med. 3, 122. doi: 10.1038/ s41746-020-00332-0. Sep 16, 2020.




domenica 25 ottobre 2020

# gst: NikS, a small RNA molecule uses a sort of 'bet-hedging' strategy to survive and infect

<< More than half of the world's population carries the bacterium Helicobacter pylori in their stomach mucosa. It often causes no problems throughout life, but sometimes it can cause inflammation, and in some cases, it can even lead to the development of stomach cancer. Helicobacter pylori uses several 'virulence' factors that allow it to survive in the stomach and can lead to the development of disease. (AA) report that multiple of these factors are centrally regulated by a small RNA molecule called NikS.  >>

<< The fact that Helicobacter pylori can colonize such a hostile environment as the stomach so successfully is also due to a special genetic strategy: Like other pathogens, H. pylori uses a strategy known as phase variation to adapt as flexibly as possible to changes in its environment. Phase variation means that the bacteria constantly switch expression of a gene at random through genetic mutations, meaning that some bacteria in a population will always be ready to express the important gene when it becomes important—a sort of 'bet-hedging' strategy. >>

Robert Emmerich. Small RNA as a central player in infections. University of Würzburg. Oct 15, 2020. 


Sara K. Eisenbart, Mona Alzheimer, et al. A Repeat-Associated Small RNA Controls the Major Virulence Factors of Helicobacter pylori. Mol Cell. vol 80, issue 2, P210-226.E7. doi: 10.1016/ j.molcel.2020.09.009. Oct 15, 2020. 



lunedì 19 ottobre 2020

# ai-bot: use of soft labels with 'less than one'-shot task in AI learning models

<< Deep neural networks require large training sets but suffer from high computational cost and long training times. Training on much smaller training sets while maintaining nearly the same accuracy would be very beneficial. In the few-shot learning setting, a model must learn a new class given only a small number of samples from that class. One-shot learning is an extreme form of few-shot learning where the model must learn a new class from a single example. (AA)  propose the 'less than one'-shot learning task where models must learn N new classes given only M<N examples and (they) show that this is achievable with the help of soft labels. >>

Ilia Sucholutsky, Matthias Schonlau. 'Less Than One'-Shot Learning: Learning N Classes From M<N Samples. arXiv:2009.08449v1. Sep 17, 2020


Karen Hao. A radical new technique lets AI learn with practically no data. Oct 16, 2020.  


FonT: sara' verosimilmente intrigante osservare come una 'macchina AI' sapra' esercitare sugli umani il potere di cooptazione ...


lunedì 12 ottobre 2020

# chem: choose a molecule from an online 'Spotify' for chemistry and synthesize it with a desktop-sized bot

AA << have found a way to create new sets of instructions for robot chemists by harnessing the power of natural language processing. They developed a computer program called SynthReader to scan through scientific papers and recognize sections which outline procedures for organic and inorganic chemical synthesis. Synthreader automatically breaks those procedures down to simple instructions and stores them in a format the team call Chemical Description Language, or XDL, which is a new open source language for describing chemical and material synthesis. Those XDL files are chemical instructions which can in principle be read any chemical robot in. The team built an easy-to-use interface called ChemIDE to integrate with any robotic chemist system and allow the XDL instructions to be turned into chemicals. The only human input required is ensuring that the equipment the robot needs to make the molecules is set up correctly. >>

'Digital chemistry' breakthrough turns words into molecules. University of Glasgow. Oct 2, 2020. 


S. Hessam M. Mehr, Matthew Craven, et al. A universal system for digitization and automatic execution of the chemical synthesis literature. Science. Vol. 370, Issue 6512, pp. 101-108. doi: 10.1126/ science.abc2986. Oct 2, 2020.





giovedì 8 ottobre 2020

# gst: observing the crystallization process in a droplet

<< Crystallization is the assembly of atoms or molecules into highly ordered solid crystals, which occurs in natural, biological, and artificial systems. However, crystallization in confined spaces, such as the formation of the protein shell of a virus, is poorly understood. Researchers are trying to control the structure of the final crystal formed in a confined space to obtain crystals with desired properties, which requires thorough knowledge of the crystallization process. >>

AA << used a droplet of a colloid—a dispersion of liquid particles in another liquid, like milk—as a model for single atoms or molecules in a sphere. Unlike single atoms or molecules, which are too small to easily observe, the colloid particles were large enough to visualize using a microscope. This allowed the researchers to track the ordering of single particles in real time during crystallization. >>

<< We visualized the organization process of colloid particles in numerous droplets under different conditions to provide a picture of the crystallization process in a sphere, >> Peng Tan

<< Based on their observations, the team proposed that the crystallization process involved three stages: initial ordering on the surface "skin" of the droplet, nucleation and growth in the core of the droplet, and then slow ripening of the whole structure. First, a skin consisting of a single layer of ordered colloid particles rapidly formed on the droplet surface. Next, crystallization occurred in the core of the droplet, far from the crystallized skin. The competition between crystallization in these two regions controlled the structure of the final crystal. The researchers found that the "soft" (long-range) interactions between the negatively charged colloid particles affected their organization and the resulting crystal structure. These soft interactions are dominated by kinetics, that is, the interactions that form the fastest, rather than those that use the least energy to give the thermodynamically stable structure, illustrating that kinetics plays an important role in crystallization in a confined space. It was already known that thermodynamics contributes strongly to the final structure of crystals. >>

Having a ball: Crystallization in a sphere. University of Tokyo. Sep 21, 2020.


Chen Y., Yao Z., et al. Morphology selection kinetics of crystallization in a sphere. Nat. Phys. doi: 10.1038/ s41567-020-0991-9. Sep 21, 2020.


Also

Control of material crystallization by agitation. Osaka University. Jun 08, 2017.


keyword 'drop' or 'droplet' in FonT





mercoledì 7 ottobre 2020

# astro: the turbulent history of Ryugu

<< The asteroid Ryugu may look like a solid piece of rock, but it's more accurate to liken it to an orbiting pile of rubble. >>

<< Ryugu is considered a C-type, or carbonaceous, asteroid, meaning it's primarily composed of rock that contains a lot of carbon and water (..) As expected, most of the surface boulders are also C-type; however, there are a large number of S-type, or siliceous, rocks as well. These are silicate-rich, lack water-rich minerals and are more often found in the inner, rather than outer, solar system. Given the presence of S- as well as C-type rocks on Ryugu, researchers are led to believe the little rubble-pile asteroid likely formed from the collision between a small S-type asteroid and Ryugu's larger C-type parent asteroid.  If the nature of this collision had been the other way around, the ratio of C- to S-type material in Ryugu would also be reversed. >>

Rock types on Ryugu provide clues to the asteroid's turbulent history. University of Tokyo. Sep 21, 2020. 


Tatsumi E., Sugimoto C., et al. Collisional history of Ryugu’s parent body from bright surface boulders. Nat Astron. doi: 10.1038/ s41550-020-1179-z. Sep 21, 2020.


Also

How small particles could reshape an asteroid. FonT. Sep 26, 2020.





martedì 6 ottobre 2020

# zoo: Tatupa, a random genus name for fixing a rare species of tropical Heteroptera with long antennas

AA << has discovered a new genus and species of bug from the island of Borneo in Southeast Asia. It was named Tatupa grafei and classified as belonging to plant bugs (Miridae). >>

Miridae << are extremely rare in different collections. The fact is that in nature they live in the forest floor and have a cryptic lifestyle. >>

<< Most aspects of the behavior of the Tatupa grafei bugs are unknown due to the extremely small number of its representatives. These insects are often found on fungi growing on rotten wood. Because of this, it has been suggested that these bugs feed on fungi, but whether this is true remains to be explored. It is also possible that Tatupa grafei eats smaller insects, which feed on fungi. The third version is that the bug menu can be mixed and consist of both fungi and insects. >>

<< The genus name Tatupa is a random combination of letters. The scientists could not come up with a suitable name for it for a long time. It was important that no animal has the same name. Additionally, the scientists needed to find out if the word Tatupa exists in any languages and what it means. It turned out that there was only one hit on the Internet—in an episode of a Polish television game where its participants are busy coining new words. The species is named after the Brunei professor Ulmar Grafe, who had provided significant support to the scientists. >>

Entomologists discover a rare species of tropical Heteroptera with long antennae. St. Petersburg State University. Sep 22, 2020. 


Veronica D. Tyts, Anna A. Namyatova, et al. Tatupa grafei, a new genus and species of Cylapinae (Heteroptera, Miridae) from Brunei Darussalam.  ZooKeys 946: 37-52. doi: 10.3897/ zookeys.946.51780. Jul 6, 2020.