Август 2020 г.

Российская наука и мир (по материалам зарубежной электронной прессы)

CONTENTS / ОГЛАВЛЕНИЕ


• Russia sets mass vaccination for October after shortened trial
• Russia plans to remove radioactive subs, reactors from its Arctic sea floor
• Russian researchers claim disulfiram, a drug used to treat alcoholism, may be effective against COVID-19
• Comme le mammouth, un rhinocéros laineux sans doute victime du réchauffement
• Russian institutes develop welding quality control method for ITER
• Some bacteria have incomplete ribosomes, a new study reports
• Russian design for vanadium redox flow batteries
• Mesoscale photonic method increases range of optical tweezers
• Luna-25 lander renews Russian moon rush
• Ancient Siberian carved mammoth ivory yields amazing new information!
• Three major nuclear accidents, as seen by young American and Russian professionals

В октябре Россия планирует начать общенациональную вакцинацию от коронавируса. Критики, однако, напомнили о российском обыкновении «срезать углы» в исследованиях фармацевтической продукции и выразили сомнения в безопасности вакцины, испытания которой еще не закончены.

Russia plans to launch a nationwide vaccination campaign in October with a coronavirus vaccine that has yet to complete clinical trials, raising international concern about the methods the country is using to compete in the global race to inoculate the public.
The minister of health, Mikhail Murashko, said Saturday that the plan was to begin by vaccinating teachers and health care workers. He also told the RIA state news agency that amid accelerated testing, the laboratory that developed the vaccine was already seeking regulatory approval for it.
Russia is one of a number of countries rushing to develop and administer a vaccine. Not only would such a vaccine help alleviate a worldwide health crisis that has killed more than 680,000 people and badly wounded the global economy, it would also become a symbol of national pride. And Russia has used the race as a propaganda tool, even in the absence of published scientific evidence to support its claim as a front-runner.
"I do hope that the Chinese and the Russians are actually testing the vaccine before they are administering the vaccine to anyone," Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases in the United States, warned a congressional hearing on Friday.
State television in Russia has for several months now promoted the idea of Russia leading the competition. In May, a government report claimed that the first person in the world to be vaccinated against the virus was a Russian researcher who had injected himself with a vaccine early in the development process.
Russia will start Phase III trials of the vaccine in early August, said Kirill Dmitriev, a senior official with Russia Direct Investment Fund, a government-controlled investor in the country’s vaccination effort. A Phase III trial is the only way to determine if a vaccine is effective.
The World Health Organization maintains a comprehensive list of worldwide vaccine trials. But there is no Russian Phase III trial on the list.
Still, a Russian regulatory agency is expected to approve the vaccine this month, Mr. Dmitriev said. That is far earlier than timelines suggested by Western regulators, who have often said a vaccine would become available no sooner than the end of the year.
"We believe it will be one of the first vaccines with regulatory approval," Mr. Dmitriev said.
But with limited transparency in the Russian program, separating the science from the politics and propaganda could prove impossible. Critics have already drawn attention to Russia’s tradition of cutting corners in research on other pharmaceutical products and accusations of intellectual property theft.
The U.S., Canadian and British governments have all accused Russian state hackers of attempting to steal vaccine research, casting a shadow over Russia’s claim to have achieved a medical breakthrough. Russian officials have denied the accusation and say their leading vaccine is based on a design developed by Russian scientists to counter Ebola years ago.
Russia was once at the forefront in virology and vaccinations. In the Soviet era, its doctors led the world in some areas of research, but spending has shriveled in recent decades. Medicines are sometimes approved with limited or no testing.
Russian researchers have continued to advance a range of vaccines since the beginning of the pandemic. The candidate to be given in October is similar to a vaccine developed by Oxford University and AstraZeneca.
The Russian vaccine was developed by the Gamaleya Institute in Moscow. It uses two strains of adenovirus that typically cause mild colds in humans. Adenovirus vaccines are in trials in various countries. They are genetically modified to cause infected cells to make proteins from the spike of the new coronavirus.
The Gamaleya Institute tested its vaccine on soldiers, raising ethical questions about consent, though the defense ministry said all of the soldiers had volunteered. The institute’s director, Aleksandr Gintsberg, went on television in May to say he tried the vaccine on himself before announcing the completion of trials in monkeys.
"There is an escalation in the geopolitics of vaccine research," said Cliff Kupchan, chairman of Eurasia Group, a risk consulting firm. But "what remains of the vast scientific complex of the Soviet period is a shadow of what it was," he said.
Countries with vaccine production capacity - abundant in Russia and India - could wind up inoculating their populations by copying a successful vaccine, even if they did not in fact develop it. In April, the Serum Institute in India announced that it had plans to mass-produce a vaccine, with permission from the developer, before clinical trials had ended.
"In all likelihood, the country producing on their soil will be the first to get it, even if they don’t own it," Mr. Kupchan said. "I don’t know how much international law and patent protection will apply here. People are pretty desperate."
Mr. Dmitriev, of the Russia Direct Investment Fund, has attributed Russia’s research success to the Soviet Union’s once-formidable scientific study of viruses.
"We have this very significant legacy of Russia being a leader of vaccines in the Soviet time and today," he said. "We don’t have to create many things from scratch."
He contrasted that history with Trump administration’s Operation Warp Speed program, which is financing experimental research by Pfizer and Moderna for a genetic vaccine.
"In the last 20 years, the world took a turn toward molecular biology," said Aydar A. Ishmukhametov, the director of the Chumakov Institute, a Russian vaccine maker. "The Russian school has preserved virology."
Russia also has an advantage, Mr. Ishmukhametov said, in its vast, Soviet-era industrial base for growing viruses for vaccines. In the pandemic, the country has turned to a secretive laboratory in Siberia with roots in the Soviet Union’s biological weapons program, which included the study of anthrax to target humans and plant pathogens that would destroy American crops.
The laboratory, Vektor, is now testing whether viruses that cause influenza, measles or vascular stomatitis - a livestock disease - can be put to use for a coronavirus vaccine.
The science of mass producing vaccines has deep roots here. Aleksei Chumakov, a virologist and son of the founder of the Chumakov Institute, recalled a summer job he held as a teenager chopping up kidneys harvested from African green monkeys. Even though the monkeys had been slaughtered, Mr. Chumakov said, their kidney cells lived on for many months, used to grow the polio virus in large, rotating glass cylinders.
"You kept stirring it and gradually the clumps came apart," he said.
As scientists gained proficiency in growing so-called immortal cell lines - human or animal cells that are modified to divide indefinitely - they replaced cultures from fresh monkey kidneys.
The Chumakov Institute has used an immortal monkey kidney cell line from 1962 to grow coronavirus for a proposed vaccine using whole, inactivated viruses, which may be used as an alternative if the vaccine targeting just the spike protein fails.
The Gamaleya Institute developed its vaccine using a human cell line first cultured in 1973, known as Hek293 - the same line used in the Oxford-AstraZeneca vaccine. Like a number of other cell lines used in medical research, Hek293 began with cells taken from an aborted fetus, raising objections from abortion opponents, including Roman Catholic clerics.
The first human cell line was derived from the cancer that killed Henrietta Lacks in 1951. HeLa, as it was known, made its way into Soviet laboratories during the Cold War. Viktor Zuyev, an 91-year-old emeritus professor of virology at the Gamaleya Institute, recalled using it to cultivate flu virus.
He was unbothered by the question of ethics.
"Why not?" he said. "It is very humane to the next generation" to use a dying person’s tissue for scientific experimentation. "If it can benefit humanity," he said, "of course it is ethical."

В ближайшие восемь лет Росатом планирует поднять со дна Карского и Баренцева морей остатки шести затонувших атомных подводных лодок и ледоколов, представляющих наибольшую радиационную опасность. Всего же на дне арктической акватории находится около 18 тысяч радиоактивных объектов.

Russian state atomic energy corporation Rosatom is planning to remove the most dangerous radioactive items from the country’s Arctic seafloor.
State news agency TASS reports that the six most radioactive items will be removed from the seafloor over the next 8 years.
The objects include the sunken parts of an icebreaker, reactors with spent nuclear fuel and nuclear submarines, according to TASS.
In a statement emailed to Fox News Wednesday, Rosatom cited a European Commission-funded feasibility study, which reported about 18,000 radioactive objects on the seafloors of the Kara Sea and the Barents Sea. "Six of them - namely reactors from a K-11, a K-19, and a K-140 submarine, two entire K-27 and K-159 submarines, and the spent fuel from an old Lenin icebreaker reactor - contain more than 90% of the objects’ collective radioactivity," Rosatom explained.
"We consider even the extremely low probability of radioactive materials leaking from these objects as posing an unacceptable risk for the ecosystems of the Arctic," Rosatom added. "Thus, we see it necessary to raise all six objects, including the K-27 and K-159 submarines. Raising all six objects, safely transporting them for disposal, and preparing them for long-term storage will take at least eight years."
"This is a complex, unique, and unprecedented project." the company said. "It will require the combined efforts of many organisations in Russia so as to efficiently obtain information on levels of radioactivity, the types of equipment that will be needed to lift the objects, and transportation needs, amongst other issues. Safety is our main priority, and therefore the primary determinant of the project’s timeline is the imperative to minimize risks to personnel, the surrounding population, and the environment."
On its website, Russia’s nuclear submarine decommissioning organization puts the cost of raising the six objects at 278 million Euros ($327.8 million).
Environmental organization the Bellona Foundation recently reported that nuclear officials from Norway and Russia have met online to discuss raising sunken nuclear subs in the Arctic. Most of the subs were deliberately scuttled by the Soviet military during the Cold War, according to the Oslo-based non-profit organization. K-159 was being towed to a scrapyard when it sank during a storm in the Barents Sea on Aug. 30, 2003, according to Getty. Nine crew members died in the sinking.

С помощью метода молекулярного моделирования химики из Высшей школы экономики и Института органической химии РАН исследовали структуру белка Mpro, необходимого вирусу COVID-19 для создания собственных копий внутри клетки-хозяина, и проверили ее на взаимодействие с рядом известных лекарств. Оказалось, что два существующих препарата, дисульфирам и нератиниб, способны остановить работу белка и, соответственно, размножение коронавируса.

A group of researchers in Russia have claimed that disulfiram (a drug used to treat alcoholism) and neratinib (a drug used for breast cancer treatment) may be effective against COVID-19.
The study was conducted by a chemist team from Zelinsky Institute of Organic Chemistry and HSE University in Russia. The findings of the study, published in the journal Mendeleev Communications, suggest that we should look for drugs that target conserved areas (those that do not change) in the SARS-CoV-2 virus.
Otherwise, a medicine effective against one strain of the virus may not be effective against another strain.
COVID-19 is a contagious disease that spreads through respiratory droplets and fomites. The disease has affected almost 19 million people already and has killed over 711,000.
Since the disease is so new and developing new drugs takes time, scientists and health practitioners around the world have been focusing on repurposing existing drugs to treat the condition. Whether it is the ebola drug remdesivir or the flu drug favipiravir, all the approved drugs for the disease had been developed previously.
The Mpro protein and molecular docking
Mpro is a protease (an enzyme) that the COVID-19 causing virus needs to make copies of itself inside the host cell. Since this enzyme is resistant to mutations, it is previously suggested to be an ideal target site for drugs. In fact, the HIV drugs lopinavir/ritonavir that have been suggested for COVID-19 treatment are a type of protease inhibitors that work on 3CLpro and PLpro (other proteases) of the SARS-CoV-2 virus.
The process of molecular docking is used to study how two compounds interact with each other. Usually, the ligand (the drug in this case) fits perfectly into the active site (Mpro here) to make a complex and leave an enzyme (in this case, SARS-CoV-2) useless. However, experts say that such a strong docking does not happen in SARS-CoV-2. So, the researchers studied the structure of the Mpro protein to find new active sites that may be able to bind strongly with drugs and hence can be used to stop the enzyme from functioning.
Disulfiram and neratinib
Trying to find an effective drug for the disease, the researchers went through the list of FDA approved drugs and their metabolites and their ability to bind to Mpro active site. It was found that sulfur-containing drugs can bind with a strong affinity to the active site of Mpro. However, only disulfiram makes stable complexes. This drug acts in two different ways. First, it acts as a covalent inhibitor of the Mpro enzyme as shown previously with MERS and SARS virus. Covalent inhibitors bind to the target enzyme and keep it from functioning. Second, it works against the reduction of glutathione (an antioxidant) in COVID-19 patients.
Glutathione therapy is suggested to be effective in the management of coronavirus disease. To deal with alcoholism, disulfiram acts on the enzyme acetaldehyde dehydrogenase and stops its functioning. This enzyme plays a role in the metabolism of ethanol in the liver and when it stops functioning, a compound called acetaldehyde grows in the person’s body. This causes vomiting and pain and over time, the person starts to associate these symptoms with alcohol and starts to dislike it.
Neratinib, on the other hand, is a tyrosine kinase inhibitor and is used as an adjuvant (to improve the effectiveness of the original treatment) in the treatment of breast cancer. To stop breast cancer, this drug binds irreversibly to some receptors in cancer cells and keeps them from replicating.
In the case of SARS-CoV-2, neratinib also acts by covalent interaction, (like disulfiram) however, the type of interaction in both drugs is a bit different. As per a news release by HSE University, disulfiram can inhibit Mpro at a concentration of 100nm (nanomolar); the effect of neratinib is suggested to not be enough for clinical use.

Проанализировав ДНК 14 шерстистых носорогов, живших на территории современной Сибири, российские и шведские ученые пришли к выводу, что основной причиной вымирания этих животных стало изменение климата, а не истребление первобытными охотниками. Исследование показало, что после появления людей в регионе популяция носорогов оставалась стабильной более 10 тысяч лет и начала сокращаться лишь с наступлением беллинг-аллередского потепления.

Un rhinocéros à fourrure brune pesant deux tonnes vivait dans le nord-est de la Sibérie avant de disparaître il y a environ 14.000 ans. Son extinction est-elle due à la chasse par les humains, ou bien à la hausse de la température à cette époque?
Une équipe de chercheurs suédois et russes a trouvé un élément de réponse dans des fragments d'ADN de 14 de ces animaux préhistoriques (Coelodonta antiquitatis), leurs codes génétiques révélant que les populations de rhinocéros étaient restées stables pendant des millénaires en cohabitation avec les humains, leur déclin brusque coïncidant avec un réchauffement à la fin de la dernière période glaciaire, à la fin du Pléistocène.
"Cela rend plus probable l'hypothèse que les changements climatiques d'il y a 14.000 ans furent la cause principale de l'extinction, plutôt que les humains", dit à l'AFP Love Dalén, généticien à l'université de Stockholm qui a mené l'étude, publiée jeudi dans la revue Current Biology.
Comment des brins d'ADN prélevés sur quelques bêtes retrouvées dans des sols gelés peuvent-ils nous éclairer sur le nombre d'animaux vivant à une époque donnée?
La taille d'une population d'une espèce est proportionnelle à son niveau de diversité génétique et au degré de consanguinité, explique Love Dalén. L'analyse du génome complet d'un rhinocéros datant d'il y a 18.500 ans, et notamment la comparaison entre les chromosomes hérités de la mère et ceux hérités du père, a montré que cette diversité génétique était élevée, et que la consanguinité était faible.
"Le génome d'un individu est une mosaïque de tous ses ancêtres", dit Love Dalén. "On arrive à conclure qu'il y a 18.000 ans, ce rhinocéros appartenait à une grande population, et ses ancêtres appartenaient également à de grandes populations, des milliers et des dizaines de milliers d'années auparavant".
Les humains étant arrivés il y a 30.000 ans dans cette partie de la Sibérie, les chercheurs en concluent que pendant environ 12.000 ans, malgré la chasse, les rhinocéros ont survécu sans décliner. Jusqu'au réchauffement dit de Bølling-Allerød.
La même équipe avait auparavant publié le génome du mammouth laineux, et pense que pour cet autre mégaherbivore, le réchauffement climatique et non la chasse était aussi à l'origine de l'extinction (la communauté scientifique continue cependant d'en débattre).
La différence est que les mammouths se sont éteints en deux fois: ceux du continent ont disparu en même temps que les rhinocéros, mais quelques centaines ont survécu sur l'île Wrangel, au large de la Sibérie, six millénaires de plus, avant leur extinction définitive.
D'une extinction à l'autre: le plus proche cousin actuel du rhinocéros laineux est le rhinocéros de Sumatra. Il est en danger de disparition, avec 80 animaux survivant à ce jour. La cause est ici bien identifiée: c'est l'homme (braconnage, réduction de l'habitat).

В российских институтах будет создана методика контроля надежности деталей для экспериментального термоядерного реактора ИТЭР. В Томском политехническом университете разрабатывают программы для неразрушающего контроля сварных соединений, а Институт ядерной физики им. Г.И.Будкера СО РАН занимается устройствами для диагностики параметров плазмы в реакторе.

Non-destructive testing specialists at Russia’s Tomsk Polytechnic Institute (TPU) is to develop methods for checking the reliability of seams on components of the International Thermonuclear Experimental Reactor (ITER) reactor, TPU said on 11 August. The specialists will develop methods and programmes for testing welded joints using ultrasound on important elements of the ITER fusion reactor, under construction in France.
The Budker Institute of Nuclear Physics of the Siberian Branch of the Russian Academy of Sciences (INP SB RAS) is developing a number of devices to diagnose plasma parameters in the reactor. The components of these devices are welded and the quality and reliability of the seams need to be highly accurate. TPU specialists will develop methods to control their quality.
"ITER is a nuclear facility with very high requirements for the quality and safety of all systems used. In particular, 100% quality control of all welded seams is required. TPU is solving this important scientific and technical problem, the control of seams, using ultrasound," said Alexander Burdakov, adviser to the Directorate of INP SB RAS and head of the INP SB RAS Laboratory. The devices and parts, which are to be checked using TPU's methods, are large in size, which makes other non-destructive testing methods such as x-ray extremely inconvenient, the researchers said.
"This will be the second project for ITER, involving TPU specialists. Previously, we created an ultrasonic tomograph to inspect the details of the reactor's first wall; it is unequalled in Russia or throughout the world. It is currently in experimental service at the DV Efremov Institute of Electrophysical Apparatus (NIIEFA)," said Dmitry Sednev, head of the TPU Engineering School of Non-Destructive Testing. This previous project demonstrated to international experts that the instruments and methods for control offered by TPU are applicable to ITER and provide the required level of quality control, Sednev added. TPU is to present its methods and programmes for ultrasonic testing in November 2020.

Молекулярные биологи Сколтеха и Института проблем передачи информации им А.А.Харкевича РАН проанализировали ДНК 214 штаммов бактерий с коротким геномом и выяснили, что некоторые из них могут обходиться без полного набора рибосомных белков.

A team of Russian scientists has determined which proteins can be safely lost in the ribosome, a composition of macromolecules found within all living cells.
The researchers are from the Skolkovo Institute of Science and Technology (Skoltech) and the Kharkevich Institute for Information Transmission Problems, both in Moscow, Russia. Their report appears in the latest journal Molecular Biology and Evolution.
Some Ribosomes Are Incomplete, Yet They Remain Stable
Ribosomes are considered "universal cellular machines." They are found in both eukaryotes (cells with membrane-bound organelles, i.e. nucleus) and prokaryotes (those that do not). These molecular machines are responsible for synthesizing biological proteins in a process called "translation."
Ribosomes are generally made up of small and large ribosomal subunits. Each subunit has ribosomal ribonucleic acid (rRNA) proteins and ribosomal proteins (RPs).
While these traits are generally similar across cells, previous studies have reported that there are strains of bacteria that continue to function even without a complete set of ribosomal proteins. The research team was led by Mikhail Gelfand, Skoltech Professor and Vice President For Biomedical Research, set out to analyze 214 samples of relatively small bacterial genomes.
The team was able to identify a set of "missing" proteins. Only nine ribosomal proteins were totally conserved, and the rest of the 48 other ribosomal proteins were missing in at least one bacterial strain from the sample.
"Tiny genomes are characteristic of endosymbionts, bacteria that live within other bacteria or eukaryotic cells," Gelfand explained. He added that in this relatively static environment, plus "weak selection," this genome information tends to lose to some non-essential genes. He likened it to some multicellular parasites that lack entire organs, yet still continue to function.
Gelfand also addressed the common preconception that the ribosome is the most conserved organelle with a standard and consistent protein set. Even in the current record for simplicity among bacteria, 121 genes, the Skoltech professor noted that it is impossible to "encode all fifty-something" RPs, which explains why some of these proteins are missing. In their study, researchers were able to show that determining the missing proteins are not random.
A Practice of Bacterial Decluttering
Evidence shows that the ribosomal proteins belonging to the small subunit were more conserved than those in the large subunit. Also, most of the lost ribosomal proteins were those located on the surface of the ribosome. Because of this, the proteins have fewer contacts with other parts of the ribosome.
The report also noted that these proteins were incorporated into the rest of the macromolecular machine later in evolution, suggesting that bacteria implements a "last in, first out" criteria in dropping ribosomal proteins.
Another interesting point in the study is that the top three bacteria with the shortest genomes in the dataset also have the most missing ribosomal proteins. This suggests a positive correlation between the number of remaining RPs and the bacteria's genome size.
The researchers, however, noted that while ribosomal proteins leave a "downsizing" or "decluttering" bacterial genome, they are still among the last to leave. This is mainly because they are still a part of the ribosome, which is an essential part of most cells.

Российские физики предложили новую, более простую и дешевую конструкцию проточных редокс-батарей, накопителей для долгосрочного хранения больших объемов энергии.

Scientists at a Russian research institute have proposed a new method of producing a critical part of the membrane electrode assembly (MEA) used in vanadium redox flow batteries.
Researchers from the Institute of Problems of Chemical Physics - part of the Russian Academy of Sciences (RAS) - claim their method of assembling graphite flow field plates is faster and cheaper than the existing approach and will make the technology more accessible to research.
Flow field plates are layers in the membrane electrode assembly that pump electrolytes to electrodes for oxidization or reduction and are typically milled in dense graphite plates in a process the Russian group described as time-consuming.
The RAS researchers have proposed assembling the plates instead from several thin layers of flexible graphite materials, with the channels needed to distribute electrolytes cut into the sheets of graphite foil, enabling easy modification of flow field configuration. "The necessary patterns in them are cut by a laser and then these layers are superimposed on each other to get the required field," said research paper co-author, Roman Pichugov. The new procedure, he said, "takes only a few minutes, which is much less than traditional milling of graphite. Plus, cheaper materials are used and, as a result, there is more scope for variation and selection of flow fields."
The researchers claim testing confirmed a vanadium-sulfuric acid electrolyte used with the new flow field plates "outperforms the cell with conventional graphite plates with the same parameters of the flow field."
"We have proposed a completely new design of MEA which will facilitate the research process and greatly reduce [the] entrance threshold for new research groups into this area," said research co-author Dmitry Konev. "In the future, this will help to achieve significant progress and will bring distributed energy resources from [a] niche positioning to [a] very high level of commercialization, including in Russia."
The device which featured the novel field flow plates has been described in the study Electrolyte Flow Field Variation: A Cell for Testing and Optimization of Membrane Electrode Assembly for Vanadium Redox Flow Batteries, published in Chemistry Europe, and showed 734 mW/cm2 of peak power density and 84.3% energy efficiency.
The RAS group will now develop a 20 W vanadium flow battery featuring ten of their devices in partnership with Moscow-based fuel cell company Inenergy LLC.

Ученые Томского политехнического университета и Института оптики атмосферы имени В.Е.Зуева СО РАН сумели увеличить дальность действия и область захвата оптических пинцетов (устройств, позволяющих манипулировать микроскопическими объектами с помощью лазера) с помощью плоского зеркала.

A team from Tomsk Polytechnic University (TPU), working with scientists from the V.E. Zuev Institute of Atmospheric Optics of the Siberian Branch of the Russian Academy of Sciences, has increased the operation range and stability of optical tweezers. In the team’s method, light, interacting with a microparticle, is focused in the form of a photon jet in the direction opposite the radiation incidence. The photon jet functions as a trap.
Forming a photon jet from a dielectric particle with the ratio of a particle and a medium higher than two can increase the optical traps’ capture area, said Igor Minin, project manager and professor of the TPU Division for Electronic Engineering. To form a classic photon jet, the ratio of the refractive indices of a particle and a medium must be less than two. It was not previously believed that scientists could increase the refractive index and simultaneously form a photon jet.
The Minin-led team instead formed a jet in the reflective mode. Placing a flat mirror behind a dielectric particle generated double-focused light when the light was focused through a particle onto the mirror. The mirror reflected light back to the particle, forming the jet, which had a ratio of a particle and a medium higher than two.
The team used microparticles made of a dielectric material, such as quartz, instead of lenses to increase the optical field’s degree of localization in the optical traps’ focus area.
"In the longitudinal direction, the region of localization of nanoparticles is determined by the size of the antinodes/nodes of the standing wave," Minin said. "In the transverse direction it is determined by the size of the width of the photonic jet. The length of the capture region is determined by the length of the photon jet - and can reach 10 wavelengths."
Minin and his colleague (and brother), TPU professor of physics Oleg Minin, first demonstrated the ability to form a photon jet using dielectric particles without axial symmetry of the spatial form in 2014. The research showed that by manipulating the shape of a particle, the team could also dictate the parameters and shape of the photon. In 2016, the Minins and a team of researchers modified a subwavelength, standing-wave optical trap based on photon jets formed in the reflection mode. In the subwavelength optical trap, the width of the generated jet, not the focus lens parameters, determined the minimum size of the focus area. A decrease in the diameter of the jet waist compared with the size of the waist in the focus of the lens increased the energy density in the focal region.
The ongoing research has also shown the possibility of forming a photon jet from particles of a three-dimensional shape as opposed to the conventional cylinders and/or spheres, Igor Minin said.
"We named our lines of research in these areas ‘mesoscale photonics,’" Minin said. A corresponding conference, called "Photonics and Plasmonics at the Mesoscale," was held in April this year at SPIE Photonics Europe.
Optical tweezers are just one application of the science, and experiments intended to confirm the simulation results in practice are underway. Those experiments, Igor Minin said, are planned in both the optical and acoustic ranges.
The Russian Foundation for Basic Research partially funded the work. The research was published in Optics Letters (www.doi.org/10.1364/OL.398367).

«Луна-25», полет которой намечен на октябрь 2021 г., должна стать первой российской станцией, севшей на поверхность спутника Земли после 1976 г. По мнению экспертов, амбициозная программа России по возвращению на Луну вполне осуществима, но сопряжена с рисками технического и управленческого характера.

There is a multicountry moon rush in progress. NASA is orchestrating the Artemis program of robotic and human lunar exploration, due to launch human explorers in 2024 at the earliest. China is preparing to hurl a sample-return mission to the moon this year, joining a Chinese lander and rover that are now on the lunar far side. Other nations, such as Japan and India, as well as private spaceflight firms, also have future lunar exploration in their crosshairs.
Now an "old-timer" is joining the celestial fray. Russia’s federal space agency Roscosmos announced in early August that flight units of scientific instruments for its Luna-25 moon lander had been delivered from the Space Research Institute of the Russian Academy of Sciences (IKI) to the Lavochkin Scientific and Production Association(which is part of Roscosmos). The flight is scheduled to launch in October 2021. "The Luna-25 space project opens a long-term Russian lunar program, which includes missions to study the moon from orbit and surface, the collection and return of lunar soil to Earth, as well as, in the future, the construction of a visited lunar base and full-scale development of our satellite.," according to a statement from Roscosmos officials.
Russia is no stranger to going the lunar distance as part of the former Soviet Union. Though it did not succeed in putting people on the lunar surface, the latter nation chalked up noteworthy space race firsts from the late 1950s to the 1970s. The Soviet Union was the earliest to send a spacecraft to the moon, perform a flyby of its far side, make a soft landing on its surface, send an orbiter around it and return a circumlunar probe back to Earth, as well as to robotically return lunar samples. And the nation landed the first rover to wheel across the natural satellite’s landscape.
In July Russia’s moon-bound scientific instruments reached the factory floor. The Luna-25 mission and a subsequent moon lander on the books are a partnership between the country and the European Space Agency. Experts say the ambitious Russian return-to-the-moon program is on track so far, but it faces risks, both technical and managerial.
RE-CREATING CAPABILITY
"We’ve all been waiting a long time" for Russia’s reactivation of its moon exploration program, says David Parker, director of human and robotic exploration at the European Space Agency. Luna-25’s eight Russian science instruments are starting to come together under the auspices of IKI, he says. The lander, headed for the moon’s south pole, is part of a new multinational quest to explore the lunar polar regions and appraise the nature of ice deposits there and their potential as resources for future missions.
Next year’s Luna-25 takeoff "is about re-creating capability that [Russia] had before moving on to more ambitious missions," Parker points out. Roscomos and the ESA are "learning about each other. Very different organizations and different decision-making approaches. There’s a very hierarchical approach on the Russian side and a high amount of pragmatism on the European side. It’s a very positive working relationship."
The ESA is on the hook for delivering a small Pilot-D demonstration camera for Luna-25. A similar camera will be a key piece of a precision-landing-and-hazard-avoidance system that the European agency is producing for Russia’s Luna-27, due to launch in 2024. Luna-27 will also carry the ESA’s Prospect drill and a miniature laboratory that, together with another Russian instrument, will search for water ice and other chemicals under the moon’s surface.
FLAGSHIP MISSION
"It is very exciting to anticipate Russia’s return to the moon," says James Head, a space scientist at Brown University. Work on Luna-25 appears to be progressing well despite COVID-19, he says, with no work stoppages reported so far.
After nearly 45 years have lapsed since its last foray to the moon, the Russian space program seems ready to finally mount a return, says Brian Harvey, an independent space analyst and author who diligently tracks that program. "I have a sense that setting the date [of launch] was an attempt to force the issue and make sure it would happen - a psychological self-incentive, as it were."
"Right off the bat, I have to snicker at the name Luna-25," says Jay Gallentine, an independent space historian who is sharply focused on robotic solar system exploration. That designation makes it sound like the lander is the latest iteration of a continuous line of moon missions, he says, when, in fact, Luna-24, the previous venture, launched in 1976. Space experts blame the long lag between moon missions on a legacy of intermittent funding, as well as management and quality control issues. There is now a stronger, more effective direction from Russian top officials than at any time since 1991, Harvey says. "Partnering with ESA is a definite attempt to spread costs and bring stability," he adds. "The Russians have always kept their side of a deal. And once they sign up for something with Europe, it will happen."
Harvey says the Russians will work hard to get Luna-25 off the ground. "The things that might stop them would be if they uncovered problems during testing or rocket problems," he says. "In the past couple of years, Russia has delayed missions when these things were not right. But this is a good thing, because they are applying quality control more effectively."
Software reliability is Gallentine’s primary concern about the Luna-25 mission’s success. "History has shown that spacecraft designers always go through a post-launch period where they are learning how to operate the very machines they built. The Russians do not have a favorable track record with computers and software," he emphasizes.
CORRUPTION QUAGMIRE
The stakes for Luna-25 are high, says Asif Siddiqi, a professor of history at Fordham University who studies Russian space exploration. "Luna-25 is quite paramount. If it fails, I think that will have a domino effect on many other things," he says. Alternatively, if it is triumphant, the mission could pave the way for a new era in the country’s space program. The forthcoming Luna mission is the first demonstration of that program in a deep-space capacity in decades, Siddiqi says. "I think people are really nervous about it in that sense," he adds.
Siddiqi cites a quagmire of mismanagement and corruption, along with Russian space ruminations that never match up with the needed rubles, for the long delay. "There’s such a hangover from the Soviet Union times that people are still living the dream of an amazing global space program. But resources and management just [aren’t] there," he says. "Historically, Russia was a great space power. But there’s an awareness that that’s in the past."

Археологи Сибирского федерального университета и Новосибирского государственного университета изучили найденные на палеолитической стоянке Усть-Кова (Красноярский край) фигурки и бусины из бивня мамонта возрастом 24 тысячи лет, определив, какие инструменты, технологии и красители использовали древние резчики.

A team of Siberian archaeologists has studied a collection of 24,000-year-old mammoth ivory revealing hitherto unknown secrets of ancient craft technologies. The year 2020 has produced a number of incredible scientific papers about ancient mammoths and their interactions with early humans. Topics covered in these papers include the oldest mammoth traps ever discovered in Mexico, dating back 12,000 years, and mammoth huts in Russia dating back more than 25,000 years. And now, a team of researchers from the Siberian Federal University and Novosibirsk State University have published their detailed reconstruction of a carved mammoth ivory technique that was used to carve ornaments and sculptures dating back more than 24,000 years. Carved mammoth ivory is not unusual but understanding how and why they were carved has never been easy.
Hand-Crafted Carved Mammoth Ivory From A Lost World
A string of beads and an ancient figurine made from mammoth ivory were discovered at the Paleolithic site of Ust-Kova, in the Kezhemsky District of Siberia, at the mouth of the Kova River. These artifacts prove that Paleolithic people made and used "drills, cutters, and even leveling blades" 20,000 years ago. And according to the scientists’ recent article, published in the journal Archaeological Research in Asia, the new data obtained will help us better understand the relations between the early hunters of different Siberian territories.
The archaeologists from Krasnoyarsk have been excavating this site since the mid-1950s and based on radiocarbon dating results they have determined that the site was occupied over 20,000 years ago. While various ornaments and tools made from mammoth ivory have been recovered, until now, the technologies used to manufacture them were unknown. Prof. Nikolay Drozdov of the Siberian Federal University told that his team studied "a mammoth figurine, a seal sculpture, and bracelets and beads of different sizes that were created around 24 thousand years ago."
A detailed microscopic analysis of each object identified the marks left by production tools. Using these images, the team was able to reconstruct the ancient technology used to make them. The paper also demonstrates that the craftsperson’s first step was to break a mammoth tusk into segments before smaller pieces were turned into beads. And to make these beads the master mammoth carver had to cut them into rectangles and bore holes in the center of each piece with a stone drill.
Mammoth Ivory Crafts Were Colored With A Dark-Red Color
Larger mammoth ivory fragments were used to create smaller animal sculptures. But to create the solid mammoth ivory figurine the craftsman had to first outline its head and legs with a leveling blade before removing the excess bone with a cutting tool. And after the body of the figurine was completed it was decorated with a pattern to give the effect of eyes and hair.
The scientists also studied traces of an unknown dark-red pigment that was found on the sculptured mammoth ivory pieces. Chemical analysis revealed that these ancient craftspeople made paint from a mixture of "manganese and magnesium." The scientists believe this mineral pigment was extracted from salt found on rocks near the site.
Symbolic Colors From 24,000-Years-Ago?
One of theories explored in the new paper is that mammoth ivory figurine was painted symbolically with a red pigment on one side and black pigment on the reverse side. This points to the mythologies of the much-later Ust-Kova people of this region, who believed that the color red represents life while black means death. However, for this theory to be true the meaning of these two colors would have to have remained unchanged for more than 24,000 years.
At the end of their research paper, the scientists concluded that the mammoth ivory ornaments had been in use for many years and that they had been repaired regularly. This strongly suggests these ornaments were special to the ancient hunters who made them. The new study is also expected to help anthropologists better understand the complex relationships between different tribes and their ancestral territories. This would be possible from a comparative analysis of carved mammoth ivory samples from different sites. With this kind of data scientists will eventually be able to determine whether hunting tribes residing in different territories were in contact with each other. Furthermore, this kind of research may one day help to identify individual craft styles and tool types of master mammoth ivory carvers from so long ago.

Об американо-российском Форуме молодых специалистов атомной отрасли, созданном для общения и обмена идеями между студентами, аспирантами и молодыми учеными двух стран. В этом году темой стали крупные ядерные аварии: Три-Майл-Айленд (1979), Чернобыль (1986), Фукусима (2011), их причины и последствия. По итогам Форума журнал «Бюллетень ученых-атомщиков» опубликовал пять совместных статей.

In a series of Bulletin articles in June 2019, young American and Russian professionals examined the future of global nuclear power. They made their case for nuclear power, driven by their concern about global climate change, and also identified the principal challenges that must be overcome. Safety of nuclear power was judged to be the major risk, followed by the risks of nuclear proliferation, security, and nuclear waste disposal, and the economic challenges to increased use of nuclear power, especially in the United States.
We asked the group of young professionals to do a deeper dive on the issue of nuclear safety after last summer’s airing of the popular HBO miniseries Chernobyl. The miniseries took a lot of liberties with the technical facts, but it captured the personal hardships and suffering of the nuclear disaster. We expanded the problem to include the nuclear accidents at Three Mile Island in the United States and Fukushima in Japan, so as to cover the effects of the world’s three major nuclear accidents on the future of nuclear power.
In the spirit of the previous five iterations of the Young Professionals Nuclear Forum, we asked roughly a dozen young American and a like number of Russians to study and exchange views and ideas. We had them collaborate online and followed up with a table-top exercise - conducted, in this case, in Moscow in November 2019. As in the past, the young professionals’ exchange of ideas on nuclear issues was organized by the Center for International Security and Cooperation at Stanford University, with participation from universities and other organizations across the country. In Russia, the Moscow Engineering Physics Institute (MEPhI), Russia’s flagship research university in nuclear engineering, continues to be an enthusiastic partner. The young professionals are students, postdoctoral fellows, and early career professionals.
The young professionals conducted research before the meeting, deliberated and debated within their teams during the meeting, and presented their findings to the larger group and the panel of senior mentors at the end of the exercise. During the past six months they have captured the essence of their findings in the five articles featured in this special presentation in the Bulletin.
Since the inception of the Young Professionals Nuclear Forum in 2016, 25 Americans and more than 30 Russians have participated in six forums - four in Moscow and two at Stanford. On the American side, participants have included graduate students and postdocs in theoretical physics, nuclear chemistry, nuclear engineering, and material science, along with current students and graduates of some of the finest US international relations and nonproliferation programs. On the Russian side, most participants are graduate students in nuclear engineering, international relations, computer sciences, and project management at MEPhI. The topics have spanned the nuclear landscape from preventing nuclear terrorism, to advising on current nuclear crises in North Korea and Iran, to arms control and the prospects of a world without nuclear weapons.
It is remarkable how often both Russians and Americans have mentioned that learning about alternative views and perceptions of an issue was their major takeaway from the meetings. Examining the three major nuclear accidents - which occurred in three different decades and in three different countries with radically different governments and cultures - to assess their causes, the responses, the consequences, and the communication governments engaged in with the public provided fertile ground for discussion and debate.
The young professionals prepared rigorously, conducting their own research and participating in on-line lectures and discussions with senior Russian and American mentors, several of whom had direct experience in responding or advising the responses to the accidents. These were augmented by in-person lectures at MEPhI and participation of the senior professionals as mentors during the group deliberations. The Russian and American young professionals were divided into six groups, each with mixed Russian and American participants, to assess, discuss and present their responses to six questions we posed related to the accidents.
The five articles they have written for the Bulletin are of interest not so much in that they break new ground about the accidents; countless articles and scores of books have been written about them. But the articles do represent the views of the younger generation looking back at what went wrong across the spectrum of the three accidents, what challenges the nuclear industries face today, and how nuclear risks should be communicated to the public. The articles also demonstrate that a group of young scholars working together across cultural and disciplinary divides can overcome the biases inherent in their country’s views of the causes and legacies of the accidents and arrive at a common assessment.
Much as in the 2019 articles on nuclear power and climate change, these young scholars concluded that international cooperation is essential to ensure nuclear safety because one country’s nuclear accident is everyone’s. Sharing lessons learned across borders and over time is imperative. Their review showed that whereas the US nuclear industry learned from the failures at Three Mile Island, the Soviet Union did not learn the lessons of TMI, and Japan did not learn the lessons of TMI or Chernobyl.
The young professionals also look ahead and collectively identify key areas that they believe need to be addressed to make nuclear energy a part of a sustainable future. They emphasize the importance of governments assuring the independence of regulatory agencies. They stress that beyond the physical consequences of an accident, the social and psychological effects of exposure must be fully incorporated into accident response activities via active community engagement both before and after an accident. The young professionals envision new forms of crisis communication and management that rely on engaging citizens through public intellectuals and citizen-science networks, participatory real-time data collection, and radiation mapping. For them, a major lesson is the imperative to provide full and timely information for the public, so it can make informed decisions both in crisis response and in assessing nuclear power as a low-carbon option in a rapidly warming world.
This Young Professionals Nuclear Forum demonstrated again that cooperation between Russians and Americans on nuclear issues is possible and can be productive - even during the disruption of a global pandemic. It underscores the objective of our efforts to turn to the younger generation at a time when most official avenues of US-Russia cooperation on nuclear issues has been terminated: After all, it is that younger generation which will have to live with the consequences, if their countries no longer cooperate to mitigate global nuclear dangers.

предыдущий месяц

1998-2020

следующий месяц