Shimizu T.,Max Planck Institute for Extraterrestrial Physics |
Shimizu T.,Terraplasma GmbH |
Hara M.,Tohoku University |
Hara M.,Mitsubishi Group |
And 6 more authors.
International Journal of Plasma Environmental Science and Technology | Year: 2016
Atmospheric plasmas have large potential in many industrial applications including biomedicine because they can produce relevant reactive species for reactions. When atmospheric plasmas are applied to biological samples, these samples are often covered by a liquid layer. It is important to understand the transport of reactive species since the plasma discharge itself also drives a gas flow. In this study, a plasma discharge was produced between a wire electrode and the surface of water by high voltage. This plasma discharge consists of several streamer discharges. The development of a thermal field between the wire electrode and the surface water as well as in the water was observed using the Schlieren visualization technique and a high speed camera. In addition, discharge photos with short exposure time were taken with an image intensifier. A thermal field was found to develop in the gas phase and a circulating flow was formed in the water in the case of low conductivity of 0.8 μS/cm due to the formation of gas flow. Our experiments shows that generation of higher gas velocity could occur with lower conductivity of water.
PubMed | Gagarin Research and Test Cosmonaut Training Center, OHB System AG, Max Planck Institute for Extraterrestrial Physics, RAS Joint Institute for High Temperatures and 6 more.
Type: Journal Article | Journal: The Review of scientific instruments | Year: 2016
New complex-plasma facility, Plasmakristall-4 (PK-4), has been recently commissioned on board the International Space Station. In complex plasmas, the subsystem of m-sized microparticles immersed in low-pressure weakly ionized gas-discharge plasmas becomes strongly coupled due to the high (10
News Article | December 5, 2016
Thanks to a new odor-cancelling technology, now you can have your doughnuts without smelling like the oil they were fried in(Credit: sytnik/ Depositphotos ) I love smelling like a grease trap, said no one ever. The question of how to get rid of the smell of cooking grease from one's clothes and surroundings has attracted advice ranging from soaking the garments in ammonia and hot water, to spraying vodka on everything. In the near future, there might no longer be a need to resort to such measures thanks to a new technology that uses cold plasma technology to zap these odors right at the source. Past studies have shown how cold plasma, with its bactericidal properties, can be used to disinfect human skin and wounds, kill drug-resistant bacteria and get rid of lice, fungi and viruses. So why not apply this technology to getting rid of cooking odors? Most range and ventilation hoods are designed to be energy efficient, with odor reduction a distant afterthought. In the models that do get rid of the smells, the health benefits are typically negligible as the chemicals used in the process end up producing ozone, which is an equally harmful pollutant. To remove odours, the plasma is first generated by sparking an electrical discharge in the air between a short rod electrode sitting in the middle of a cylindrical electrode. It then spreads out to form a plasma disc when agitated by a magnetic field. The cooking fumes are first filtered through two conventional air filters, which remove fine dust, particles and humidity, leaving behind blue smoke, bacteria and the odor molecules. A third filter captures the blue smoke from the burning fat while the plasma filters neutralize the germs and odor molecules that pass through them. "The thin plasma sheet breaks the offending molecules up into harmless components that do not smell and do not need to be extracted afterwards," explains Gregor Morfill, a professor at the Max Planck Institute and CEO of Terraplasma, a firm that specializes in the applications of cold plasma technology. "It's also about a thousand times faster than the traditional chemical method," he says, further elaborating to New Atlas that the new technique takes a millisecond compared to the current one, which takes seconds. The difference might seem negligible, but these extra milliseconds explain why the traditional professional cooking hoods are more than a meter in length. Since the filter cartridge is just 10 cm (3.9 in) long, owners of existing Blümchen systems will be able to use them in their systems, without having to change their entire hood to accommodate the new technology. "The potential market is huge," says Georg Hirtz, CEO of Blümchen. "There are theoretically 600,000 systems in Germany alone, so with an average lifetime of 10 years, around 60,000 units a year are needed here." There's even the possibility of adapting the filter for household use, which would increase its market share as up to 10 million new cooker hoods are sold annually to households in Europe, notes Hirtz. While the idea of a compact all-in-one frying station that can eliminate odors certainly sounds like a welcome prospect for restaurant owners, cooks and diners alike, the efficacy of the plasma filters in an actual professional cooking environment remains to be seen. The tests, according to Morfill, were conducted with ammonia. No information was given regarding the airflow volumes or scale at which they were conducted. Brett Singer, a staff scientist at Lawrence Berkeley National Laboratory who studies the impact of cooking emissions on indoor air quality tells New Atlas that one of the challenges with cooking odors lies in catching all the fumes. "This requires a large hood with relatively large airflows for commercial applications," he says.
Ahlfeld B.,University of Veterinary Medicine Hannover |
Li Y.,Max Planck Institute for Extraterrestrial Physics |
Li Y.,Terraplasma GmbH |
Boulaaba A.,University of Veterinary Medicine Hannover |
And 7 more authors.
mBio | Year: 2015
Human norovirus (NoV) is the most frequent cause of epidemic nonbacterial acute gastroenteritis worldwide. We investigated the impact of nonthermal or cold atmospheric pressure plasma (CAPP) on the inactivation of a clinical human outbreak NoV, GII.4. Three different dilutions of a NoV-positive stool sample were prepared and subsequently treated with CAPP for various lengths of time, up to 15 min. NoV viral loads were quantified by quantitative real-time reverse transcription PCR (RT-qPCR). Increased CAPP treatment time led to increased NoV reduction; samples treated for the longest time had the lowest viral load. From the initial starting quantity of 2.36×104 genomic equivalents/ml, sample exposure to CAPP reduced this value by 1.23 log10 and 1.69 log10 genomic equivalents/ml after 10 and 15 min, respectively (P<0.01). CAPP treatment of surfaces carrying a lower viral load reduced NoV by at least 1 log10 after CAPP exposure for 2 min (P<0.05) and 1 min (P<0.05), respectively. Our results suggest that NoV can be inactivated by CAPP treatment. The lack of cell culture assays prevents our ability to estimate infectivity. It is possible that some detectable, intact virus particles were rendered noninfectious. We conclude that CAPP treatment of surfaces may be a useful strategy to reduce the risk of NoV transmission in crowded environments. IMPORTANCE Human gastroenteritis is most frequently caused by noroviruses, which are spread person to person and via surfaces, often in facilities with crowds of people. Disinfection of surfaces that come into contact with infected humans is critical for the prevention of cross-contamination and further transmission of the virus. However, effective disinfection cannot be done easily in mass catering environments or health care facilities. We evaluated the efficacy of cold atmospheric pressure plasma, an innovative airborne disinfection method, on surfaces inoculated with norovirus. We used a clinically relevant strain of norovirus from an outbreak in Germany. Cold plasma was able to inactivate the virus on the tested surfaces, suggesting that this method could be used for continuous disinfection of contaminated surfaces. The use of a clinical strain of norovirus strengthens the reliability of our results as it is a strain relevant to outbreaks in humans. © 2015 Ahlfeld et al.
Kumagai S.,Toyota Technological Institute |
Chang C.-Y.,Toyota Technological Institute |
Jeong J.,Toyota Technological Institute |
Kobayashi M.,Nara Institute of Science and Technology |
And 2 more authors.
Japanese Journal of Applied Physics | Year: 2016
A device consisting of Si microwells and microplasma sources has been fabricated for plasma treatment of individual cells cultured in media. We named the device plasma-on-chip. The microwells have through-holes at the bottom where gas-liquid interfaces form when they are filled with media containing biological samples. The microplasma sources, which supply reactive species, are located on the back of each microwell. Through the gas-liquid interface, the reactive species are supplied to the cells. Chlorella cells were used to demonstrate the feasibility of the device and after three minutes of plasma treatment, the fluorescence intensity of Chlorella cells appeared to be decreased. Optical emission spectroscopy identified O and OH radicals in the plasma, which can affect the cells. In the analysis of biological samples such as human cells or tissues, this device raises the possibility of revealing the mechanisms of plasma medicine in more detail. © 2016 The Japan Society of Applied Physics.
Okada T.,Toyota Technological Institute |
Chang C.-Y.,Toyota Technological Institute |
Kobayashi M.,Nara Institute of Science and Technology |
Shimizu T.,terraplasma GmbH |
And 2 more authors.
Archives of Biochemistry and Biophysics | Year: 2016
We have developed a micro electromechanical systems (MEMS) device which enables plasma treatment for cells cultured in media. The device, referred to as the plasma-on-chip, comprises microwells and microplasma sources fabricated together in a single chip. The microwells have through-holes between the microwells and microplasma sources. Each microplasma source is located on the backside of each microwells. The reactive components generated by the microplasma sources pass through the through-holes and reach cells cultured in the microwells. In this study, a plasma-on-chip device was modified for a stable plasma treatment. The use of a dielectric barrier discharge (DBD) technique allowed a stable plasma treatment up to 3 min. The plasma-on-chip with the original electrode configuration typically had the maximum stable operation time of around 1 min. Spectral analysis of the plasma identified reactive species such as O and OH radicals that can affect the activity of cells. Plasma treatment was successfully performed on yeast (Saccharomyces cerevisiae) and green algae (Chlorella) cells. While no apparent change was observed with yeast, the treatment degraded the activity of the Chlorella cells and decreased their fluorescence. The device has the potential to help understand interactions between plasma and cells. © 2016 Elsevier Inc.
Arndt S.,University of Regensburg |
Landthaler M.,University of Regensburg |
Zimmermann J.L.,Max Planck Institute for Extraterrestrial Physics |
Zimmermann J.L.,Terraplasma GmbH |
And 10 more authors.
PLoS ONE | Year: 2015
Cold atmospheric plasma (CAP) has been gaining increasing interest as a new approach for the treatment of skin diseases or wounds. Although this approach has demonstrated promising antibacterial activity, its exact mechanism of action remains unclear. This study explored in vitro and in vivo whether CAP influences gene expression and molecular mechanisms in keratinocytes. Our results revealed that a 2 min CAP treatment using the Micro-PlaSter ß in analogy to the performed clinical studies for wound treatment induces expression of IL-8, TGF-ß1, and TGF-ß2. In vitro and in vivo assays indicated that keratinocyte proliferation, migration, and apoptotic mechanisms were not affected by the CAP treatment under the applied conditions. Further, we observed that antimicrobial peptides of the ß-defensin family are upregulated after CAP treatment. In summary, our results suggest that a 2 min application of CAP induces gene expression of key regulators important for inflammation and wound healing without causing proliferation, migration or cell death in keratinocytes. The induction of ß-defensins in keratinocytes describes an absolutely new plasma strategy. Activation of antimicrobial peptides supports the well-known antibacterial effect of CAP treatment, whereas the mechanism of ß-defensin activation by CAP is not investigated so far. © 2015 Arndt et al.
News Article | November 30, 2016
Cooking food such as French fries in hot fat or oil releases malodorous molecules that are extremely hard to remove or disperse. These odours are typically destroyed in bulky and expensive commercial cooker hoods by chemicals that create ozone as a byproduct – which must be removed because of health concerns. Instead, a German manufacturer of deep-fat fryers, Blümchen, is taking a different approach, based on plasma experiments that have been running on the Space Station since 2001. Plasma is usually a hot, electrically charged gas but it is possible to create 'cold plasmas' at room temperature. Cold plasma has proved to be an extremely effective bactericidal agent and can also tackle fungi, viruses and spores. It is safe to touch, which makes it attractive for many applications. Methods for generating cold plasmas were developed at the Max Planck Institute for Extraterrestrial Physics in Germany, where the notion of using electrons to create the plasma for removing odours was patented. Funded by ESA and in collaboration with the Russian space agency, scientists led by Professor Gregor Morfill were responsible for the first experiment on the Station. His team took advantage of weightlessness in orbit to study complex plasmas, which provided the impetus to develop the cold plasma technology. The most recent fourth version of this experiment is still working on the Station, making the plasma study experiment the longest-running in space. A grant from ESA has helped to transform the knowledge into practical applications on Earth. Since 2013 Prof. Morfill has been CEO of the Terraplasma company, which has already applied the cold plasma to medical and hygiene problems, and to water treatment. To remove odours, Terraplasma's new system generates the plasma by sparking a glowing electrical discharge in the air between a short rod electrode sitting in the middle of a cylindrical electrode. The discharge is initially a narrow line about 1 mm thick somewhere between the electrodes, but when it is made to move rapidly by a magnetic field it spreads out to produce a plasma disc. The foul air is then passed through this disc for cleaning. From space to the kitchen German EurA Consult from ESA's Technology Transfer Programme broker network had long been aware of Prof. Morfill's specialty and his spin-off successes at Terraplasma, and introduced the technology to Blümchen, who were seeking a better answer for industrial cooker hoods. "This industry is not one that normally adopts novel technologies, but we recognised a big potential here," said Johannes Schmidt of EurA Consult. "It helps that both companies are open-minded, think creatively and can work fast to bring a new development to market." "The new design works by using electrons within the plasma to neutralise odours," explained Prof. Morfill. "The thin plasma sheet breaks the offending molecules up into harmless components that do not smell and do not need to be extracted afterwards. "It's also about a thousand times faster than the traditional chemical method." The filter cartridge, only 10 cm long, can be integrated into existing systems as well as into new, far smaller designs. Owners of small food stalls and even households may benefit from new cooker hoods based on the cold plasma filters. "The potential market is huge," noted Georg Hirtz, CEO of Blümchen. "There are theoretically 600 000 systems in Germany alone, so with an average lifetime of 10 years, around 60 000 units a year are needed here. "Developing this for private households would increase that yet further, as up to 10 million new cooker hoods are sold annually to households in Europe." With a full prototype planned for 2017, the first devices using this space spin-off should be available on the market in early 2018. Blümchen will produce the filters and supply them or license the technology to cooker hood manufacturers. Meanwhile, Terraplasma continues to look at and develop new terrestrial applications using the cold plasma results from space. Together with German medical company Dynamify, it has formed Terraplasma Medical at ESA's Bavarian incubator to develop systems for treating chronic and acute wounds and skin diseases. The company is also looking into new medical systems using the same cold plasma technology for future long spaceflights.
Welz C.,University of Gottingen |
Emmert S.,University of Gottingen |
Canis M.,University of Gottingen |
Becker S.,Johannes Gutenberg University Mainz |
And 5 more authors.
PLoS ONE | Year: 2015
Head and neck squamous cell cancer (HNSCC) is the 7th most common cancer worldwide. Despite the development of new therapeutic agents such as monoclonal antibodies, prognosis did not change for the last decades. Cold atmospheric plasma (CAP) presents the most promising new technology in cancer treatment. In this study the efficacy of a surface micro discharging (SMD) plasma device against two head and neck cancer cell lines was proved. Effects on the cell viability, DNA fragmentation and apoptosis induction were evaluated with the MTT assay, alkaline microgel electrophoresis (comet assay) and Annexin-V/PI staining. MTT assay revealed that the CAP treatment markedly decreases the cell viability for all tested treatment times (30, 60, 90, 120 and 180 s). IC 50 was reached within maximal 120 seconds of CAP treatment. Comet assay analysis showed a dose dependent high DNA fragmentation being one of the key players in anti-cancer activity of CAP. Annexin-V/PI staining revealed induction of apoptosis in CAP treated HNSCC cell lines but no significant dose dependency was seen. Thus, we confirmed that SMD Plasma technology is definitely a promising new approach on cancer treatment. © 2015 Welz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PubMed | Ludwig Maximilians University of Munich, Johannes Gutenberg University Mainz, evangelical hospital Dusseldorf, Terraplasma GmbH and University of Gottingen
Type: Journal Article | Journal: PloS one | Year: 2015
Head and neck squamous cell cancer (HNSCC) is the 7th most common cancer worldwide. Despite the development of new therapeutic agents such as monoclonal antibodies, prognosis did not change for the last decades. Cold atmospheric plasma (CAP) presents the most promising new technology in cancer treatment. In this study the efficacy of a surface micro discharging (SMD) plasma device against two head and neck cancer cell lines was proved. Effects on the cell viability, DNA fragmentation and apoptosis induction were evaluated with the MTT assay, alkaline microgel electrophoresis (comet assay) and Annexin-V/PI staining. MTT assay revealed that the CAP treatment markedly decreases the cell viability for all tested treatment times (30, 60, 90, 120 and 180 s). IC 50 was reached within maximal 120 seconds of CAP treatment. Comet assay analysis showed a dose dependent high DNA fragmentation being one of the key players in anti-cancer activity of CAP. Annexin-V/PI staining revealed induction of apoptosis in CAP treated HNSCC cell lines but no significant dose dependency was seen. Thus, we confirmed that SMD Plasma technology is definitely a promising new approach on cancer treatment.