|Российская наука и мир|
(по материалам зарубежной электронной прессы)
Ученые из Университета ИТМО и Межотраслевого научно-технического комплекса «Микрохирургия глаза» разработали и испытали нетравматичный лазерный метод лечения катаракты. Одновременно используются два лазера - один для разрушения помутневшего хрусталика, второй - для стимуляции заживления окружающих тканей, при этом излучение обоих лазеров идет по одному оптоволокну.
Cataract is among the most widespread eye diseases. According to WHO, up to a third of all visual impairments have to do with cataract. The treatment methods are well-known but can sometimes be traumatizing. Scientists from ITMO and the S.N. Fyodorov Eye Microsurgery Complex spent over 20 years working on reducing the side effects of cataract surgery. As a result, they came up with a technology where a laser is used both to destroy the clouded eye lens and to stimulate the regeneration of adjacent tissue. The researchers gave a detailed description of their method in an article that has been recently published in Optical and Quantum Electronics.
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The eye is a very important organ. A healthy eye lets us see in the light and in the dark, read fine print and trace fast objects. But if something goes wrong, the eyesight can rapidly degrade or even disappear completely. One of the common problems is the clouding of the lens, or cataract. The methods for treating cataract are being constantly improved; for one, scientists from ITMO University work on this topic in collaboration with specialists from the S.N. Fyodorov Eye Microsurgery Complex.
"The treatment method is surgical and has to do with removing the clouded eye lens and replacing it with an artificial one made of plastic or sapphire", comments Andrey Belikov, a professor at ITMO University. "The eye lens is destroyed either with ultrasound or a laser. When using a laser, a special tip is inserted into the anterior chamber of the eye close to the lens, and the laser breaks the lens into tiny fragments that are then removed from the eye. An artificial lens is then put in their place. The problem is that this process damages the adjacent tissue, and the regeneration doesn't always go well."
In the recent decades, many researchers placed their focus on reducing the traumatizing effect of cataract surgery. In 1997, scientists from ITMO University and S.N. Fyodorov Eye Microsurgery Complex, as well as several other research institutions, started to experiment with the use of laser radiation for destroying the cataract. With time, surgeons noticed that the less powerful laser can not only illuminate the surgical field but also stimulate the regeneration of the damaged tissue. So they started conducting experiments aimed at finding the optimal interaction method between the destroying and the illuminating lasers. It turned out that using both lasers simultaneously is the most efficient method. This idea called for elaborate work of optical engineers: as entering the eye with two instruments at the same time is highly undesirable, for the radiation of both lasers it was necessary to use a common optical fiber.
"The simultaneous use of two lasers is good because we get cells that are damaged but not destroyed," comments Prof. Belikov. "And it's very important to stimulate their regeneration at once. This way, the regeneration process takes place in the most favourable conditions."
As of now, the method has already been introduced at the clinic of the S.N. Fyodorov Eye Microsurgery Complex, and almost all of their cataract surgeries make use of two lasers. It has been clinically proved that in the long-term, the use of this method allows to reduce the loss of corneal endothelial cells by 1.8 times in comparison with ultrasonic phacoemulsification, and there have yet been no reports of macular edema or endothelial-epithelial corneal dystrophy.
Сибирский кольцевой источник фотонов (СКИФ) в Кольцово будет проектировать Центральный проектно-технологический институт топливной компании Росатома «ТВЭЛ». Ввод в эксплуатацию первого в России синхротрона четвертого поколения запланирован на 2024 год.
Russian fuel company TVEL (part of state nuclear corporation Rosatom) said on 13 April that its Central Design and Technological Institute (TISC) had concluded a government contract to design a scientific centre based on a new latest generation synchrotron.
The Siberian Circular Photon Source (SKIF) will be built at the science city of Koltsovo in the Novosibirsk region of Siberia.
In March, the Russian government appointed TVEL as the general designer of SKIF. The establishment of the SKIF centre is part of the national project "Science" under the auspices of the Ministry of Science and Higher Education. It is being developed by the GK Boreskova Institute of Catalysis of the Siberian Branch of the Russian Academy of Sciences.
The synchrotron and associated infrastructure are planned to be in place before the end of 2023. Commissioning of the facility scheduled is scheduled for 2024. The new centre will conduct innovative research in the fields of physics, chemistry, geology, biology and medicine.
TVEL has overall responsibility for developing the design documentation. TISC will prepare documentation for engineering surveys, design estimates and cost estimates for verification by various state bodies.
One of the residents of the SKIF centre will be the State Research Centre for Virology and Biotechnology (Vector Centre), which is developing and testing a vaccine against the new coronavirus. The Vector Centre will be able to conduct a series of biological studies as early as 2024 - at two of the six experimental stations which will comprise of the first stage of the SKIF centre. In 2025, a specialised vector station is expected to open up.
© 2020, All Rights Reserved.
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«Росатом» разработал мобильную систему стерилизации концентрированным озоном медицинского оборудования и помещений. В отличие от хлора, использование озона не имеет негативных последствий.
Scientists in Russia have developed a method of disinfecting and sterilising medical instruments, clothing, equipment, and facilities, using mobile devices for the production of concentrated ozone.
The scientists are part of the Russian State Science Centre, Troitsk Institute of Innovative and Thermonuclear Research (SSC TRINITI), a subsidiary of Rosatom’s science division.
"At the moment, most medical rooms are treated with chlorine, which is a toxic substance. Ozonation, by contrast, is a clean technology that, if used correctly, does not have adverse effects," said Stanislav Kosarev, the project’s supervisor. "Using our device allows you to sterilise scrubs and other medical instruments without thermal exposure, which will increase their lifespan."
The main advantages of SSC TRINITI’s device are its high concentrations of ozone, high disinfection and sterilisation rate, mobility, and compact size.
The mobile ozoniser is capable of disinfecting virtually any medical object occupying an area of up to 100 square metres. In terms of bactericidal efficiency, ozonation with this device is more effective than ultraviolet germicidal irradiation or treating an area with chlorine.
Another important advantage is its low cost of operation - it is expected that the centre’s ozoniser will consume half the electricity consumed by other ozonisers currently on the market. Rosatom aims to test prototype soon
Under the supervision of Alexander Basiev, a researcher of physical and mathematical sciences, a group of scientists at the research centre have learned to produce ozone at concentrations of up to 0.7 grams per litre at speeds of up to 6 kilograms per hour, using a mobile device about the size of an average home air purifier.
According to the researcher, the device is simple to use - it is placed in a sealed box alongside tools that require disinfecting and disinfects them within 15 minutes.
SSC TRINITI is scheduled to test a prototype of its mobile ozoniser in the near future to determine the product’s effectiveness in real conditions, and its possible use for medical needs.
© All content copyright 1997-2020 Clarion Energy..
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The New York Times / April 15, 2020
How Bubonic Plague Has Helped Russia Fight the Coronavirus
A network of health centers formed by the Soviet Union in the 1920s is providing expertise in quarantines and epidemic response for Covid-19.
В 1920-х годах в СССР для борьбы с чумой была создана сеть медицинских центров. Позже они занялись и другими инфекционными заболеваниями, а теперь оказались востребованы в качестве экспертной поддержки в вопросах карантина и борьбы с распространением коронавируса COVID-19.
In a remote alpine meadow in Kyrgyzstan a few years ago, a teenage boy killed and skinned a marmot. Five days later, his parents carried the sweating, delirious boy to a village hospital where he died of bubonic plague.
Like a ghost from the medieval past, the plague still makes occasional, unwelcome appearances in remote regions of the former Soviet Union, where it survives today in wild rodents. Over the centuries, with improved public hygiene, the plague declined as a threat. Today, as a bacterial infection, it is treatable with antibiotics, if caught in time. But the plague was still a lethal menace in the 1920s and also an embarrassment for the Soviet Union, which established a specialized state agency to track and contain it. Successors to that agency still exist in Russia and in half a dozen other countries that were once Soviet republics, and, with their ready quarantine plans and trained personnel, they have become a mainstay of the regional response to the coronavirus.
It is too early to tell if the former Soviet antiplague centers, as the sites were called, have made any difference in the coronavirus outbreak, which so far has infected more than 21,000 Russians, killing 170. At most, the legacy Soviet system helped delay the spread, and it is just one data point in assessing why the coronavirus moved more slowly in Russia, Ukraine and other former Soviet countries than in Western Europe and the United States. Luck, border closures or officials covering up the true numbers of deaths could also explain the low numbers. Infections are in any case now shooting up, and those countries seem to be headed the way of the rest of the world toward bulging hospitals and morgues. But employees of the antiplague centers say their early work helped, becoming a silver lining to the region’s long-lingering plague problem.
"Of course, it helped" early on, said Ravshan Maimulov, director of a regional antiplague service in Kyrgyzstan who examined the teenage plague victim when he died in 2013. He used the same quarantine plan that he had instituted after the boy’s death to respond to the coronavirus in March. When the 15-year-old had arrived at the village hospital, "the body was still damp from sweat and I felt swelling under the armpits and chin," Mr. Maimulov said. But the boy was too far gone to save, and he died within hours.
Mr. Maimulov, 57, trained at a Russian antiplague institute called Microbe. After the boy’s death, he had the authority to immediately put in motion plans for a lockdown, even though at that point they had only a partial diagnosis. He relayed the news to a regional governor in code - they would need to implement "Formula 100" - lest word leak and inhabitants of the village, Ichke-Zhergez, should try to flee before the door slammed shut. "We needed to prevent them all from running away," he said. By the next morning, police checkpoints were in place and the village was sealed.
On his recommendation, the authorities in the surrounding Issyk-Kul region used the same approach in March in introducing coronavirus lockdowns. "We worked under the operative plan for the plague," Mr. Maimulov said in a telephone interview. The region of about half a million people has reported three coronavirus cases, he said. Kyrgyzstan has reported five deaths.
Russia maintains 13 antiplague centers, from the Far East to the Caucasus Mountains, five plague research institutes and multiple field stations. In March, the authorities moved new laboratory equipment into the antiplague center in Moscow to expand its ability to test for coronavirus.
The Microbe institute, originally dedicated wholly to bubonic plague but later expanded to tackle other infections such as cholera, yellow fever, anthrax and tularemia, models the spread of the coronavirus. Starting in January, directors of antiplague centers in the Eurasian Economic Union, the Moscow-led trade alliance of Armenia, Belarus, Kazakhstan, Kyrgyzstan and Russia, held conference calls about the coronavirus. And a plague institute in Odessa, Ukraine, is among agencies responding to the coronavirus there, officials said.
"The very fact that Russia and the other former Soviet states are, exactly, former Soviet states means a common legacy," in health care, said Dmitri Trenin, director of the Carnegie Moscow Center. A legacy of focus on epidemics helped, he said. Soviet health care had haphazard success at treating individuals but "could respond like the military to epidemics," he noted.
Other analysts of former Soviet medical services say that, in the longer term, the Soviet legacy will prove no gift. The capacity to counter epidemics had degraded while little was done to improve an ability to treat patients, according to Yevgeny S. Gontmakher, a professor at the Higher School of Economics and an authority on Russian health care. "The plague doctors were the elite of a hundred years ago, not today," he said.
In Kyrgyzstan, Mr. Maimulov works in a wooden laboratory in what had been, until a few weeks ago, the medical backwater of plague control. Most years, he plans for campaigns of spraying insecticide into rodent burrows, to kill fleas and slow the spread in animals. The disease cannot be fully stamped out. "They are rodents, they reproduce quickly," he said. "It’s not worthwhile to kill them." The family of the 15-year-old boy were herding sheep in the mountains and trapping marmots for fur as a sideline. The boy skinned the marmot with a razor blade. Though the Black Death typically spreads by flea bite, in this instance the boy caught it simply by nicking his finger.
Eventually, 32 villages were put under quarantine while about 700 nurses went door to door looking for infection. Marmot hides were collected and burned. But the antiplague team had acted quickly enough. The boy was the only confirmed case.
© 2020 The New York Times Company.
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Исследовав с помощью рентгена раскрашенную глиняную голову возрастом более 2000 лет, найденную в 1968 году в одном из курганов возле села Шестаково Кемеровской области, сотрудники ИАиЭт СО РАН и ИЯФ СО РАН обнаружили вместо предполагаемого человеческого черепа череп барана. По одной из версий, таким образом мог быть символически похоронен человек, пропавший без вести.
According to a report in The Siberian Times, a team of researchers led by Natalia Polosmak of the Russian Institute of Archaeology and Ethnography and Konstantin Kuper of the Institute of Nuclear Physics used fluoroscopy to examine a head-shaped sculpture crafted by the Tagar culture more than 2,000 years ago.
The clay head, which resembles a young man, was discovered among about 15 sets of cremated human remains in a Shestakovsky burial mound in eastern Siberia in 1968. X-rays made of the artifact at the time revealed a small skull within the sculpture. Marks in the clay on the back of the head suggest it had been attached to a body, perhaps made with the rest of the individual’s remains, grass, leather, and birch bark.
The new study, however, revealed that the skull within the sculpture belonged to a ram. Polosmak suggests the Tagar people may have created a body to bury as a symbolic replacement if they were not able to recover the remains of the deceased.
"This must have been the only way to ensure the after-death life of a person who had not returned home," she said.
Researcher Elga Vadetskaya suggested that a ram’s head may have been substituted for the man’s remains if they had completely decomposed before the elaborate burial ritual had been completed.
(c) 2020 Archaeology Magazine, a Publication of the Archaeological Institute of America.
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Сотрудники факультета инновационных технологий Томского государственного университета испытали беспилотный летательный аппарат для доставки медикаментов и тест-систем для взятия анализов на коронавирус в труднодоступные населенные пункты. В отличие от аналогов, дрон ТГУ маневрен и устойчив к порывам ветра, а также может нести больший вес.
The staff of the TSU Faculty of Innovative Technologies has successfully tested the capabilities of unmanned aerial vehicles (UAVs). Tests in tasks of interest to residents of the Tomsk Region were carried out by an experienced TSU flight team using a UAV with improved characteristics - wind stability, good load carrying capacity, and increased maneuverability.
One of the set tasks was the transportation of goods across the Ob River. The tests confirmed the delivery of cargo safely.
"TSU scientists have developments with technologies using drones. For example, at the end of last year, a hardware-software complex for working with "spy" drones was completed and commissioned. The project was funded by the Ministry of Education and Science of the Russian Federation", said the rector of TSU Eduard Galazhinsky. "Now scientists at the TSU Faculty of Innovative Technologies are solving another complex technical problem - they are creating algorithmic solutions for the operation of a courier drone. In March, successful tests were conducted at the TSU campus. Now we have taken a new step and conducted tests in some tasks of interest to the region".
The use of UAVs helps to minimize the number of contacts between people and reduce the number of movements in transport.
In the future, vital goods will be delivered using drones on an ongoing basis. The geography of delivery will include areas extremely difficult to get to in the off-season or fraught with great difficulties.
© Mirage News.
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Санкт-Петербургский политехнический университет Петра Великого первым из российских вузов вошел в рейтинг Times Higher Education University Impact Rankings 2020, заняв 37 место в мире. Рейтинг посвящен оценке влияния вузов на процесс реализации целей устойчивого развития, сформулированных ООН до 2030 года.
On April 22, the British edition of Times Higher Education published the ranking "Times Higher Education University Impact Rankings 2020". Peter the Great St. Petersburg Polytechnic University (SPbPU) became the first among the Russian universities and occupied the 37th position in the world.
The ranking is dedicated to assessing the impact of universities on the process of implementing the Sustainable Development Goals (SDGs) formulated by the United Nations for the period up to 2030. The new ranking assessed the contribution of the universities to the implementation of 17 goals of the UN. Last year, St. Petersburg Polytechnic University has been ranked 85th in the international THE University Impact Rankings. This year, the SPbPU occupied the 37th position, ahead of all Russian and many leading foreign universities.
The St. Petersburg Polytechnic University obtained the highest scores for:
SDG-7: ensuring universal access to the affordable, reliable, sustainable and modern energy sources for everyone - the 5th position in the world;
SDG 13: urgent measures to combat climate change and its consequences - the 5th position in the world;
SDG-14: conservation and rational use of oceans, seas and marine resources for the sustainable development - the 21st position in the world;
SDG-8: promoting steady, inclusive and sustainable economic growth, full and productive employment and decent work for everyone - the 28th place in the world;
SDG-11: ensuring openness, security, resilience and environmental sustainability of cities and towns - the 30th position in the world.
Rector of SPbPU, Academician of the Russian Academy of Sciences Andrei Rudskoi is confident that the university's position in the ranking demonstrates its commitment to the goals of sustainable development through the established university's ecosystem, aimed at achieving the sustainable development goals. According to rector, in particular, the Polytechnic University contributes to the development of society through its R&D and innovations. Meaning, of course, the effective management of the intellectual potential, sources, quality of education, and the degree of influence on the high-tech industry and business. "We can see that the sustainable development goals defined by the UN correlate in many ways with the Russian National Projects. Within its framework the policy of socio-economic development of the country is implemented. Such as education and science, health, ecology, industry, digital economy. And our University makes a significant contribution and has achievements in every area," said the rector of SPbPU.
Copyright © 2020 PR Newswire Association LLC.
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Коллектив ученых из Германии, Нидерландов и России проанализировал данные 166 долгосрочных исследований, проведенных по всему миру, чтобы оценить изменение численности насекомых в последние десятилетия. Полученный результат показал меньшее сокращение численности наземных видов, чем в некоторых предшествующих исследованиях, а численность пресноводных видов, наоборот, возросла на 11%.
Le 24 avril, un article scientifique paru dans la revue Science vient nuancer l’idée d’un effondrement - une « apocalypse » - de la population d’insectes. L’étude, menée par une équipe de chercheurs allemands, néerlandais et russes, est intitulée Global Changes in Insect Populations Reflect Both Decline and Growth. Autrement dit : « L’évolution mondiale des populations d’insectes reflète à la fois un déclin et une croissance. »
Plusieurs recherches récentes ont fait état d’une chute drastique de l’abondance des insectes et de la richesse des espèces : selon une étude publiée en 2019, les insectes pourraient ainsi disparaître d’ici un siècle. L’article paru dans Science présente un constat plus nuancé : tout en confirmant une baisse globale des insectes à travers le monde, les chercheurs ont constaté « une augmentation de l’abondance des insectes d’eau douce à un taux de près de 11 % par décennie, peut-être en partie due à des efforts fructueux en matière d’eau propre ». Pour parvenir à ces résultats, les scientifiques ont procédé à une méta-analyse à partir de données provenant de 166 enquêtes à long terme menées sur 1.676 sites dans le monde. Il s’agirait donc de « l’évaluation la plus vaste et la plus complète à ce jour ».
Les insectes comptent parmi les animaux les plus abondants et les plus divers de la planète et jouent un rôle essentiel dans les services écosystémiques et dans la chaîne alimentaire.
© 2019 Reporterre - tous droits reservés.
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Физики из Лондонского университета королевы Марии и Института физики высоких давлений РАН вычислили предел, до которого жидкость остается жидкостью. В полученном уравнении используются две фундаментальные физические константы - постоянная Планка и соотношение массы протона и электрона.
You’ve probably never wondered how runny a liquid can get, which is no bad thing because it’s not an easy question to answer.
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There is a minimum level of viscosity - the point where a heated liquid transitions from a liquid-like to a gas-like state - but viscosity is considered near impossible to calculate from theory because it strongly depends on liquid structure, composition and interactions as well as external conditions in a complicated way.
Scientists from Queen Mary University of London (QMU) and the Russian Academy of Sciences (RAS) think they’re onto something, however. But it, too, is complicated.
In a paper published in the journal Science Advances, they suggest that two fundamental physical constants or constants of nature - measurable properties of the physical universe that do not change - govern how runny a liquid can be.
Their new equation, they say, relates the minimal value of elementary viscosity (the product of viscosity and volume per molecule) to the Planck constant, which governs the quantum world, and the dimensionless proton-to-electron mass ratio.
"This result is startling. Viscosity is a complicated property varying strongly for different liquids and external conditions, yet our results show that the minimal viscosity of all liquids turns out to be simple and universal," says lead author Kostya Trachenko, from QMU.
There are practical implications of discovering this limit too, the researchers suggest.
It could be applied where a new fluid for a chemical, industrial or biological process with a low viscosity is required - a recent example being the use of supercritical fluids for green and environmentally clean ways of treating and dissolving complex waste products.
In this instance, the discovered fundamental limit provides a theoretical guide of what to aim for. It also tells us that we should not waste resources trying to beat the fundamental limit because the constants of nature will mould the viscosity at or above this point.
Fundamental physical constants and in particular dimensionless constants (fundamental constants that do not depend on the choice of physical units) are believed to define the Universe we live in, Trachenko and colleagues say.
A finely tuned balance between the proton-to-electron mass ratio and another dimensionless constant, the fine structure constant, governs nuclear reactions and nuclear synthesis in stars leading to essential biochemical elements including carbon.
This balance provides a narrow habitable zone where stars and planets can form, and life-supporting molecular structures can emerge. Change one of the dimensionless fundamental constants slightly, and the Universe becomes very different, with no stars, heavy elements, planets and life.
"There are indications that the fundamental lower limit of liquid viscosity may be related to very different areas of physics: black holes as well as the new state of matter, quark-gluon plasma, which appears at very high temperature and pressure," suggests co-lead author Vadim Brazhkin, from the RAS.
Ученые Института космических исследований РАН экспериментально доказали, что некоторые земные микроорганизмы способны выжить в атмосфере Венеры, на поверхности Марса и во льдах спутника Юпитера Европы.
We have known that life cannot survive outside Earth as of now. No planet has been discovered which shows all the requirements that can sustain life like our Earth does. However, the Russian Academy of Sciences’ Space Research Institute researchers have simulated a kind of environment which represents Venus and has proven that life can survive on Venus. They discovered that a microscopic organism - a kind of fungi called micromycetes can thrive even in a country like Venus. Even in an environment which has a lot of radioactive radiation and temperature fluctuations. The ionizing radiation simulated during the laboratory testing clearly found out that the fungi lived on. This simulation might even prove life on Mars.
And they tried it too.
Trying to find Life on Mars
By including a few microorganisms from the Arctic, the Russian researchers tried to simulate the environment of Mars - including the radiation and the extreme temperature of -50 degrees Celsius. Surprisingly, the scientists were able to realize that the bacteria were able to survive in that temperature as well. Scientists also took a few samples of the microbial components in the Mojave Desert which, as per many scientists, are similar to the microbial communities found in Mars. They were extremely tolerant of several factors like oxidizing agents, salts, cultivation temperature, pH alterations, etc.
Researchers have also simulated a similar kind of environment representing the moon of Jupiter, Europe, which has a water ice-crust. By pushing the temperature down to -130 degrees Celsius, they found certain microbial components to sustain their life.
That life on Mars can be a possibility is discussed in their research paper. No one can deny that it is quite fascinating to find out that life can exist in these cosmic bodies which were once seen as completely uninhabitable by all life forms.
© Copyright 2019 - theunionjournal.com.
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Многие живые организмы светятся в темноте, но растения к биолюминесценции не способны. Российским ученым удалось встроить в геном двух видов табачных растений гены гриба, синтезирующего люциферин - вещество, которое и лежит в основе процесса биолюминесценции. В результате растения не только начали светиться, но и сохранили эту способность на всем протяжении жизненного цикла, чего не удавалось добиться ранее.
The glowing greenhouse of our dreams is still so very far away, but it just got a tantalising nudge closer.
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Scientists have genetically engineered a plant with not just a visible glow, but a self-sustaining glow that lasts for the duration of the plant's life cycle. It's a breathtaking improvement on previous glowing plants. It's brighter than previous genetically engineered tobacco plants, and it doesn't need to be fed with chemicals to maintain luminescence. Also, the duration of the glow is much longer than glowing plants produced using plant nanobionics. Of course, we all immediately think of a breathtaking Avatar-style night garden, glittering and gleaming in the darkness, and - further into the future - reducing our dependence on electric lighting. But glowing greenery could also help us understand the plants themselves - how their metabolism works, and how they respond to the world around them.
The team worked on two species of tobacco plant. And, unlike previous genetically engineered glowing plants, which used bioluminescent bacteria or firefly DNA, these plants were engineered using the DNA of bioluminescent fungi. "Although bacterial bioluminescence genes can be targeted to plastids to engineer autoluminescence, it is technically cumbersome and fails to produce sufficient light," the researchers wrote in their paper. "The caffeic acid cycle, which is a metabolic pathway responsible for luminescence in fungi, was recently characterised. We report light emission in Nicotiana tabacum and Nicotiana benthamiana plants without the addition of any exogenous substrate by engineering fungal bioluminescence genes into the plant nuclear genome."
It was only at the end of 2018 that a team of researchers (many of whom worked on this new research also) published a paper on the biosynthesis of fungal luciferin, the compounds that produce a glow in luminescent fungi. They discovered that these fungi synthesise luciferin from a compound called caffeic acid, worked upon by four enzymes. Two enzymes work to transform caffeic acid into a luminescent precursor; a third enzyme oxidises this precursor to produce a photon. The fourth enzyme then converts the molecule back to caffeic acid, which can be recycled through the same process. And this is where things get interesting - because caffeic acid (no relation to caffeine) is found in all plants. It's key to the biosynthesis of lignin, the wood polymer that gives plant cell walls rigidity and strength.
The team reasoned that it might, therefore, be possible to genetically engineer plants to reallocate some of their caffeic acid to the biosynthesis of luciferin, as seen in bioluminescent fungi. They spliced their tobacco plants with four fungus genes associated with bioluminescence, and carefully cultivated them. And they found that the plants glowed with a light visible to the naked eye from seedling to maturity - without any apparent cost to the health of the plant.
"The overall phenotype, chlorophyll and carotenoid content, flowering time and seed germination did not differ from wild-type tobacco in the greenhouse, with the exception of a 12 percent increase in median height of transgenic plants," the researchers wrote in their paper. "This suggests that, unlike expression of bacterial bioluminescence, expression of caffeic acid cycle is not toxic in plants and does not impose an obvious burden on plant growth, at least in the greenhouse."
They found that younger parts of the plant glowed most brightly, with the flowers growing brightest of all. These produced, the researchers said, around a billion photons per minute. That's not nearly enough to read by, but it is bright enough to be clearly visible. It's also around 10 times brighter than other genetically engineered glowing plants, the researchers said. It's not quite the brightest plant produced; that honour belongs to watercress produced by scientists at MIT using a technique called plant nanobionics, which produced a glow of around a trillion photons per second… but it only lasted 3.5 hours. This new long-term, self-sustaining glow, the team found, could act as an indicator for how the plants responded to their external environment. When they placed a banana skin nearby, for instance, the plants would glow more brightly in response to the ethylene emitted.
They also observed flickering and waves in the light, produced by internal metabolic processes that are usually hidden - suggesting that this research could be an interesting way to study plant health. "By enabling autonomous light emission, dynamic processes in plants can be monitored, including development and pathogenesis, responses to environmental conditions and effects of chemical treatment," the researchers wrote in their paper. "By removing the need for exogenous addition of luciferin or other substrates, these luminescent capabilities should be particularly useful for experiments with plants grown in the soil."
Meanwhile, the team is working on expanding the research. They have genetically modified popular flowering plants such as periwinkles, petunias, and roses. They are also trying to produce an even brighter glow, and different colours. And they are thinking much, much bigger. "Although caffeic acid is not native to animals, autonomous luminescence could also be enabled in animals," they wrote.
Wouldn't that be something.
The research has been published in Nature Biotechnology.
Ученым Санкт-Петербургского национального исследовательского Академического университета имени Ж.И.Алферова РАН удалось повысить эффективность солнечных элементов на основе арсенида галлия, используя одностенные углеродные нанотрубки вместо обычных металлических сеток.
Scientists from the Saint Petersburg Academic University in Russia claim to have raised the efficiency of gallium arsenide (GaAs) solar cells from 10.6% to 11.5% by using single-walled carbon nanotubes (SWCNTs) instead of conventional metal grid contacts.
Traditional metal grid contacts are able to provide transparency, but they also require high doping of the cell surface layer to provide efficient photocurrent collection, the researchers explained. Heavy doping and deposition are energy-intensive industrial processes, which is why they drive up production costs for similar solar cells.
The researchers are pushing aerosol-synthesized SWCNTs as an alternative, as they are said to combine optoelectronic properties, flexibility, chemical stability, and simple transfer protocols to cover large surface areas. "The SWCNTs could help greatly improve the performance of SC when applied as a transparent contact layer material," the researchers said.
The group chose SWCNT layers measuring up to 20 nm in thickness, with integral 90% transparency in the visible range and 300 ohm/sq initial sheet resistance. These features provide a good trade-off between the conductivity and optical transmittance of the SWCNT film, they explained.
They measured the PV characteristics of the SWCNT solar cells via the current-voltage characteristic (I-V), using a four-probe method with a global standard spectrum (AM1.5g) solar simulator.
"To provide electrical contact, silver paste droplets were put directly on the metal grid and SWCNTs," the research team explained. "The solar cell covered with the SWCNTs should be characterized by a lower surface resistance, which leads to the enhanced operation efficiency."
The group also said that solar cells with SWCNT contacts showed a slight increase in the short circuit current density, from 16.9 to 17.9 mA/cm2.
The proposed strategy, described in a research paper that was recently published in Energy Science & Engineering, could be applied to highly efficient flexible III-V solar cells, the scientists said.
Research into III-V solar cells has been revived in several projects over the past two years. Innovations include a method to produce gallium arsenide solar cells with a reusable germanium substrate developed by scientists at the National Renewable Energy Laboratory and the Korea Advanced Institute of Science and Technology. A research team from Germany’s Fraunhofer ISE and France’s Center for Nanoscience and Nanotechnology have also developed an ultra-thin solar cell based on gallium arsenide.
The cost of producing solar cells based on compounds of III-V element materials - named according to the groups of the periodic table they belong to - has thus far confined such devices to niche applications such as drones and satellites, where low weight and high efficiency are more pressing concerns than cost, in relation to the energy produced.
© PV MAGAZINE 2020.
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Петроглифы, найденные на Алтае в середине 1990-х и в Монголии десятью годами позже оказались удивительно похожи. Археологи ИАиЭт СО РАН пришли к выводу, что изображения были созданы в одно время и относятся к позднему палеолиту.
Paleolithic rock art found in Siberia and Mongolia is some 7,000 years older than previously thought, with ancient artists using the same artistic style in both locations.
Scientists have closely examined and compared intriguing rock drawings on the Ukok Plateau in Russia’s Altai Republic and Baga-Oygur, and Tsagaan-Salaa in northwestern Mongolia. The petroglyphs are now in different countries, but in fact they are only about 20 kilometers (12 miles) apart.
New Discoveries Resolve Unanswered Questions
The drawings were mostly found in the 1990s and early 2000s but many questions at the time remained unanswered. In particular, there was a dispute between experts as to whether the drawings showed extinct woolly mammoths that once roamed these parts - or fantastical creatures with trunks.
The new study by Russian and French researchers found new petroglyphs, which have helped the answer this conundrum. For example, at Baga-Oygur II the image of a long-gone woolly rhino was found. However, most of the image is lost due to a rock slicing, but the animal is quite recognizable with an elongated squat torso, short powerful legs, a characteristic tail, and an elongated muzzle with exaggeratedly enlarged two horns.
This discovery was useful because animals, like mammoths became extinct around 15,000 years ago in this region, making the drawings the work of Paleolithic artists. Another new image at Baga-Oygur III evidently shows a mammoth calf.
The scientists concluded that the artists worked with stone implements, and not metal. They also noted a ‘desert varnish’ on the stones - a dark crust which forms on the stones in dry conditions, suggesting a greater age than earlier assumptions of between 8,000 and 10,000 years old.
Paleolithic Rock Art Shows Similarities Across Regions
Stylistic similarities between the Mongolian and Siberian petroglyphs, further indicated the Ukok drawings to be woolly mammoths. They made their petroglyphs in the so-called Kalgutinsky style.
The experts concluded: "we attribute the petroglyphs to the Final Upper Paleolithic period, because the examples with typical features of this style depict the Pleistocene fauna (mammoths, rhinoceros). These stylistic features find their parallels among the typical examples of the Upper Paleolithic rock art of Europe."
Russian scientist Vyacheslav Molodin added: "this is a new touch to what we know about the unexplainable activities of prehistoric people in Central Asia. Science already knows about the Paleolithic era art in this region, which includes the famous series of sculptures from the Mal'ta archaeological site in the Irkutsk region of Siberia, whose ages are dated from 23,000 to 19,000 years ago, and also several examples from Angara. Therefore, the assumption that the Pleistocene inhabitants undertook rock art on open surfaces fits into this context."
The research was undertaken by Vyacheslav Molodin, Dmitry Cheremisin and Dr. Lidia Zotkina from the Institute of Archaeology and Ethnography, Novosibirsk, part of the Siberian Branch of the Russian Academy of Sciences, Jean-Michele Geneste (University of Bordeaux) and Catherine Cretin (National Museum of Prehistory, France).
Ancient Origins © 2013-2020.
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Международная группа исследователей из России, Германии и Швейцарии предположила, что странные полосы на склонах двух кратеров на Марсе могут быть следами колоссальных ледяных лавин, сошедших около миллиона лет назад.
Des caractéristiques énigmatiques cachées à l’intérieur de deux cratères d’impact martiens pourraient être les vestiges d’avalanches de glace colossales, dont la plus importante a parcouru plus de 9 miles.
Deux cratères d’impact dans le latitudes lointaines au nord de Mars avoir d’étranges traits linéaires sur leurs pentes intérieures. Nouveau recherche publié dans Planetary and Space Science suggère que ces crêtes de type moraine sont ce qui reste d’avalanches de glace monumentales eu lieu autour d’un il y a des millions d’années.
Les experts disent que c’est une théorie intéressante, mais plus de travail sera nécessaire pour renforcer la revendication.
Les scientifiques avaient précédemment soutenu que ces formes de relief linéaires ressemblaient à des moraines parce que c’est précisément ce qu’elles sont. Les moraines sont structures vallonnées et linéaires formé par des glaciers lents, qui poussent la saleté et les roches à la tête de leur avance. Dans les régions polaires martiennes, ces glaciers sont constitués de dioxyde de carbone (plutôt que de la glace d’eau qui constitue Glaciers de la Terre), mais leurs effets géologiques sont le même.
Le nouvel article, co-écrit par Sergey Krasilnikov de l’Académie russe des sciences, propose une explication alternative: fast-courant de crues glaciaires. Essentiellement, le nouvel article fait valoir que de grandes tours de glace d’eau, appelées massifs, situées le long de la pente supérieure des cratères se sont effondrées, entraînant des avalanches épiques. Les crêtes de type moraine se sont formées en accumulant des débris poussés au fond des cratères en s’effondrant massifs.
Krasilnikov et ses collègues ont simulé ces surtensions hypothétiques en utilisant les données collectées par la NASA et en effectuant des calculs indépendants. Ensemble, ces méthodes ont soutenu un scénario dans lequel «l’accumulation excessive de glace d’eau sur les pentes» a atteint «un état instable critique», entraînant des avalanches de glace et la formation des crêtes morainiques ci-dessous.
Des massifs se forment par l’accumulation régulière de givre. Finalement, le poids et la pression sont devenus si intenses que les massifs se sont effondrés, libérant leur contenu au fond du cratère, selon cette interprétation. Ces effondrements auraient été un spectacle à voir. Le plus grand des deux effondrements a impliqué environ 2,42 kilomètres carrés de glace (près de 1 mile carré), tandis que les plus petits concernaient 1,1 kilomètre carré (0,4 mille carré). Le plus grand massif était estimé à 150 mètres (492 pieds) de hauteuret le plus court de 100 mètres (328 pieds) grand.
Til tombe de la glace et des débris aurait voyagé à une estimation de 80 mètres (260 pieds) par seconde. Et parce que la gravité est plus faible sur Mars, les débris se sont répandus sur un vaste territoire, atteignant environ 15 kilomètres (9,3 miles) du point de départ dans l’effondrement le plus important, et 12 kilomètres (7,5 miles) dans le plus petit. Lors de l’effondrement du massif, l’avalanche a englobé une superficie totale s’étendant 104 kilomètres carrés (40 milles carrés).
«C’est une belle explication alternative», Mike Sori, un scientifique planétaire de l’Université de l’Arizona qui n’était pas impliqué dans la nouvelle recherche, a raconté EOS, une publication de l’American Geophysical Union. Les avalanches martiennes ont été documentées auparavant, a-t-il déclaré, mais ces crêtes ressemblent énormément à des moraines construites par des glaciers de dioxyde de carbone, a-t-il déclaré. Sori a dit davantage de preuves seront nécessaires pour faire valoir des arguments plus solides.
Les recherches futures devront également comprendre pourquoi seuls deux exemples d’avalanches de glace ont été trouvés sur Mars, comme le souligne EOS. En effet, plus d’exemples de ces étranges crêtes ajouteraient de la crédibilité à l’affirmation selon laquelle des avalanches de glace se produisent réellement sur la planète rouge.
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