The bat virus RaTG13 is a close relative of SARS-CoV-2, but unlike the causative agent of the COVID-19 pandemic, RaTG13 is poor at docking to human cells. However, the exchange of a single amino acid in the spike protein of this bat coronavirus is sufficient for it to bind to human cells via the ACE2 receptor, similar to SARS-CoV-2. This was shown in a study from the Institute of Molecular Virology at Ulm University Hospital, which was recently published in the journal Nature Communications. Another result of the work: A vaccination against SARS-CoV-2 may possibly help to prevent the skipping of such pathogens.
The causative agent of the COVID-19 pandemic, SARS-CoV-2, was most likely transmitted directly or via an intermediate host from bats to humans. The virus was able to spread so rapidly through the human population because it effectively infects human lung cells. The characteristics that allow bat viruses to jump to humans are currently poorly understood. What is known is that SARS-CoV-2 can dock to the ACE2 receptor of human cells with its spike protein and thus invade the cells. A research team led by Ulm virologist Professor Frank Kirchhoff has now shown that the exchange of a single amino acid in the spike protein of the bat virus RaTG13 is sufficient for this protein to dock to human cells via the ACE2 receptor and lead to their infection. The results were published in the renowned journal Nature Communications.
“The targeted mutation of an amino acid in the spike protein of RaTG13, specifically at position 403, allows this bat coronavirus to dock to the same receptor as SARS-CoV-2: the human ACE2 receptor.”
– Professor Frank Kirchhoff, head of the Institute of Molecular Virology at Ulm University Hospital
The research team was also able to reveal the basic mechanism that explains why the ACE2 receptor suddenly has such an attractive effect on the modified spike protein: “The exchanged amino acid in the spike protein of the virus is positively charged and interacts with a negatively charged amino acid in the human ACE2 receptor molecule,” said Fabian Zech, first author of the study and doctoral student at the Institute of Molecular Virology.
The scientific work is a perfect example of the interdisciplinary interaction between experimental laboratory work and theoretical computer modeling. On the one hand, the Ulm virus researchers altered the amino acid composition of the spike protein of the virus through the targeted generation of mutations (mutagenesis). On the other hand, computer-assisted modeling helped to elucidate protein structures and protein-protein interactions. These were carried out by Dr. Christoph Jung from Professor Timo Jacob’s Institute of Electrochemistry at the University of Ulm. So-called reactive force field methods were used to gain insights into physicochemical properties and interaction energies.
Reverse mutation makes SARS-CoV-2 less infectious
In this scientific work, the virologists from Ulm not only succeeded in using genetic engineering to enable the spike protein of the bat coronavirus RaTG13 to infect human cells. They also demonstrated that a reverse mutation in SARS-CoV-2 (R403T) weakens the pandemic agent and reduces viral infection of human cells. This result suggests that the positively charged amino acid is important for the high transmissibility of SARS-CoV-2.
The research project has revealed which properties of coronaviruses are crucial for them to jump to humans as zoonotic diseases. The results thus help to better assess the risk of future viral pandemics. And there is another aspect that makes the study interesting: the researchers also investigated whether current vaccinations against SARS-CoV-2 can protect against closely related bat viruses and thus against future zoonoses. The result: “Sera from individuals vaccinated against COVID-19 were effective in rendering the bat virus harmless. Thus, SARS-CoV-2 vaccination could help prevent future spillover of such viral pathogens to humans,” the researchers said.
Virus researchers and infection biologists from Erlangen-Nuremberg, Munich and Göttingen as well as other Ulm scientists from electrochemistry, internal medicine and medical microbiology were involved in this research project of the Ulm Institute of Molecular Virology. The study – which has already been published as a preprint and met with great interest – was supported by the DFG (including from the Heisenberg Program), the BMBF, the Free State of Bavaria and the International Graduate School of Molecular Medicine (IGradU) at the University of Ulm. This scientific work was realized within the framework of the Ulm Collaborative Research Center 1279 “Use of the human peptidome for the development of new antimicrobial and anti-cancer therapeutics”.
Responsible and sustainable action is firmly anchored in the WAGO Group’s corporate strategy. The company’s connection and automation technology is an important component of the infrastructure necessary to advance digitalization and energy efficiency, and thus contribute to global challenges such as decarbonization. The company wants to fulfill this responsibility together with customers and partners, but also within the company. Therefore, we have decided to consistently convert our vehicle fleet to alternative drives.
With a “Green Car Policy”, no pure gasoline or diesel engines will be permitted in the future. The medium-term goal is to purchase only zero-emission vehicles by 2025. By the end of this year, plug-in hybrids and electric cars will already account for 40% of the total fleet. The company’s pool vehicles, which are available for business trips at the German plants in Minden and Sonderhausen (Thuringia), will already be 80% electrified. In perspective, further concepts for sustainable mobility are to be incorporated into the policy.
“The consistent conversion of our vehicle fleet is a further step for us to make the energy transition possible together. If you want to act sustainably in the long term, you have to look at all aspects of your business. Here we can make a further contribution to saving CO2 for our company and achieve results quickly.”
– Axel Börner, Chief Financial Officer
In principle, teeth and gums can also be perfectly cared for with a normal toothbrush. However, dentists repeatedly find that most people find it easier to achieve good results with electric assistance, and are therefore increasingly advising electric brushes. TÜV SÜD product expert Andrea Mertl explains what consumers should look out for and how products are tested on the German market.
The figures speak for themselves: three quarters of all dentists in Germany are convinced that correct brushing is easier with an electric toothbrush; one in three even believes they can tell from their patients’ dentition whether they are using an electric brush or not. Today, around 40 percent of all people over the age of 14 in this country already use an electric toothbrush. Since this brushing method has long been taken for granted even by more and more kindergarten children, the market share will continue to grow significantly in the coming years. In addition, many electric fans from the very beginning are switching to new models. Here, it is not only product improvements in terms of program selection or battery charging capacities that are enticing – those who still use a retro model with an electric cord or battery operation should switch for safety or environmental reasons. New features such as a smartphone app that documents cleaning time and quality or recognizes which areas are being neglected via a connection to the camera also encourage new purchases.
Andrea Mertl is responsible for testing electric toothbrushes at TÜV SÜD: “Many manufacturers advertise that their products provide good brushing performance. With our tests, we check this on the basis of various aspects and ensure that the electric toothbrushes also clean gently, are user-friendly to use and comply with the specifications regarding safety and environmental protection.”
Innovative toothbrushing robot
An extensive test scenario has been defined for these reviews. A specially developed brushing robot has already been in use since 2017, simulating brushing performance on black-colored artificial dentures. A white paste represents plaque and impurities to be removed from the tested models. How well this is achieved is analyzed by software, which assigns scores for the criteria of interdental spaces, tooth necks, smooth surfaces and overall surface area during its evaluation. After these automated tests and, of course, a thorough safety check in which, for example, the cord and charging station are also closely examined, human test subjects of all ages come into play. They test several products from different manufacturers with different product features and from different price ranges. Only after this elaborate procedure does the company award its test seal.
Rotary model or sonic toothbrush
Basically, electric toothbrushes are based on two different technologies. Rotary models and sonic toothbrushes are still on the market, and within these groups there are of course differences in terms of functionality. Very good results can be achieved with both variants: Rotary brushes have a small, rotating round brush head that works on each tooth individually. The brushes brush with an alternating left-right movement – a semi-circular rotation of the brush head.
Sonic toothbrushes usually have larger, oval brush heads and clean a larger area at once. Nevertheless, the brushes do not clean with sound, but with vibrations that occur at a very high frequency. Meanwhile, the integrated transducers generate sound waves between 250 and 300 hertz that drive the brush head. This creates a buzzing sound, which originally gave this type of toothbrush its name. Since less pressure is required with this system, gentle cleaning is even easier and interdental spaces are also better reached, more and more users are giving preference to sonic brushes.
Special form of sonic brush: ultrasonic toothbrushes
Still relatively new on the market are ultrasonic toothbrushes, which use a special toothpaste and send tiny microbubbles into the deepest crevices of the teeth at up to 96 million vibrations per minute to loosen plaque and bacteria. While the results achieved are excellent, optimal cleaning takes significantly longer than with other systems. Moreover, at the moment this technology is still exclusively represented in the upper price segment and is mainly recommended for people with gum problems, braces or bridges.
“Whether a toothbrush with smartphone connectivity is really necessary is up to each buyer to decide. However, our experience shows that electric toothbrushes generally make good oral hygiene much easier. In any case, we advise to go for tested safety and to pay attention to the corresponding labeling when buying.”
– Andrea Mertl
More space in the control cabinet thanks to compact controller family
Now B&R is launching a new compact controller family called X20 Embedded. The devices combine performance and numerous integrated interfaces in a housing just 55 mm wide. This makes the controllers half the size of comparable devices.
Thanks to the powerful processors from the Intel Atom series, the new controllers are also suitable for demanding applications with short cycle times. The devices can even be used to control fully-fledged robot applications. Machine builders thus save costs and space in the control cabinet.
The controllers come standard with two USB ports, integrated flash memory and two Ethernet ports. Daisy-chain cabling can be easily implemented with the integrated switch. Therefore, there are no additional costs for the network infrastructure.
Hardware interfaces for POWERLINK and RS485 are also integrated in the devices. Via the RS485 interface, the user can, for example, connect frequency converters directly to the controller without any additional hardware. The power supply is also integrated. Despite the high performance, the controllers do not require a fan or battery and are therefore maintenance-free.
Optionally, any other fieldbus protocols can be added. For this purpose, the controllers are optionally available with an interface slot. All B&R interface cards can be combined with devices from the X20 embedded series. Likewise, all X20 I/O modules can be added to the controller as usual.