The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Imène Chebbi - One of the best experts on this subject based on the ideXlab platform.
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biodegraded magnetosomes with reduced size and Heating Power maintain a persistent activity against intracranial u87 luc mouse gbm tumors
Journal of Nanobiotechnology, 2019Co-Authors: Edouard Alphandéry, François Guyot, Ahmed Idbaih, Clovis Adam, Jean-yves Delattre, Charlotte Schmitt, Florence Gazeau, Imène ChebbiAbstract:An important but rarely addressed question in nano-therapy is to know whether bio-degraded nanoparticles with reduced sizes and weakened Heating Power are able to maintain sufficient anti-tumor activity to fully eradicate a tumor, hence preventing tumor re-growth. To answer it, we studied magnetosomes, which are nanoparticles synthesized by magnetotactic bacteria with sufficiently large sizes (~ 30 nm on average) to enable a follow-up of nanoparticle sizes/Heating Power variations under two different altering conditions that do not prevent anti-tumor activity, i.e. in vitro cellular internalization and in vivo intra-tumor stay for more than 30 days. When magnetosomes are internalized in U87-Luc cells by being incubated with these cells during 24 h in vitro, the dominant magnetosome sizes within the magnetosome size distribution (DMS) and specific absorption rate (SAR) strongly decrease from DMS ~ 40 nm and SAR ~ 1234 W/gFe before internalization to DMS ~ 11 nm and SAR ~ 57 W/gFe after internalization, a behavior that does not prevent internalized magnetosomes to efficiently destroy U87-Luc cell, i.e. the percentage of U87-Luc living cells incubated with magnetosomes decreases by 25% between before and after alternating magnetic field (AMF) application. When 2 µl of a suspension containing 40 µg of magnetosomes are administered to intracranial U87-Luc tumors of 2 mm3 and exposed (or not) to 15 magnetic sessions (MS), each one consisting in 30 min application of an AMF of 27 mT and 198 kHz, DMS and SAR decrease between before and after the 15 MS from ~ 40 nm and ~ 4 W/gFe down to ~ 29 nm and ~ 0 W/gFe. Although the magnetosome Heating Power is weakened in vivo, i.e. no measurable tumor temperature increase is observed after the sixth MS, anti-tumor activity remains persistent up to the 15th MS, resulting in full tumor disappearance among 50% of treated mice. Here, we report sustained magnetosome anti-tumor activity under conditions of significant magnetosome size reduction and complete loss of magnetosome Heating Power.
François Guyot - One of the best experts on this subject based on the ideXlab platform.
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biodegraded magnetosomes with reduced size and Heating Power maintain a persistent activity against intracranial u87 luc mouse gbm tumors
Journal of Nanobiotechnology, 2019Co-Authors: Edouard Alphandéry, François Guyot, Ahmed Idbaih, Clovis Adam, Jean-yves Delattre, Charlotte Schmitt, Florence Gazeau, Imène ChebbiAbstract:An important but rarely addressed question in nano-therapy is to know whether bio-degraded nanoparticles with reduced sizes and weakened Heating Power are able to maintain sufficient anti-tumor activity to fully eradicate a tumor, hence preventing tumor re-growth. To answer it, we studied magnetosomes, which are nanoparticles synthesized by magnetotactic bacteria with sufficiently large sizes (~ 30 nm on average) to enable a follow-up of nanoparticle sizes/Heating Power variations under two different altering conditions that do not prevent anti-tumor activity, i.e. in vitro cellular internalization and in vivo intra-tumor stay for more than 30 days. When magnetosomes are internalized in U87-Luc cells by being incubated with these cells during 24 h in vitro, the dominant magnetosome sizes within the magnetosome size distribution (DMS) and specific absorption rate (SAR) strongly decrease from DMS ~ 40 nm and SAR ~ 1234 W/gFe before internalization to DMS ~ 11 nm and SAR ~ 57 W/gFe after internalization, a behavior that does not prevent internalized magnetosomes to efficiently destroy U87-Luc cell, i.e. the percentage of U87-Luc living cells incubated with magnetosomes decreases by 25% between before and after alternating magnetic field (AMF) application. When 2 µl of a suspension containing 40 µg of magnetosomes are administered to intracranial U87-Luc tumors of 2 mm3 and exposed (or not) to 15 magnetic sessions (MS), each one consisting in 30 min application of an AMF of 27 mT and 198 kHz, DMS and SAR decrease between before and after the 15 MS from ~ 40 nm and ~ 4 W/gFe down to ~ 29 nm and ~ 0 W/gFe. Although the magnetosome Heating Power is weakened in vivo, i.e. no measurable tumor temperature increase is observed after the sixth MS, anti-tumor activity remains persistent up to the 15th MS, resulting in full tumor disappearance among 50% of treated mice. Here, we report sustained magnetosome anti-tumor activity under conditions of significant magnetosome size reduction and complete loss of magnetosome Heating Power.
K Ida - One of the best experts on this subject based on the ideXlab platform.
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how is turbulence intensity determined by macroscopic variables in a toroidal plasma
Nuclear Fusion, 2013Co-Authors: S Inagaki, K Ida, T Shimozuma, S Kubo, T Tokuzawa, N Tamura, Sanaei Itoh, T Kobayashi, K Tanaka, T IdoAbstract:We report observations of the dynamic response of micro-fluctuations and turbulent flux to a low-frequency Heating Power modulation in the Large Helical Device. The responses of heat flux and micro-fluctuation intensity differ from that of the change in temperature gradient. This result violates the local transport model, where turbulence is determined by the local temperature gradient. A new relationship between flux, gradient and turbulence is found. In addition to the temperature gradient, the Heating rate is proposed as a new, direct controlling parameter of turbulence to explain the fast response of turbulence against periodic modulation of Heating Power.
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characteristics of electron heat transport of plasma with an electron internal transport barrier in the large helical device
Physical Review Letters, 2003Co-Authors: K Ida, Y Takeiri, T Shimozuma, H Funaba, K Narihara, S Kubo, S Murakami, A Wakasa, M Yokoyama, K Y WatanabeAbstract:Associated with the transition from ion root to electron root, an electron internal transport barrier (ITB) appears in the large helical device, when the Heating Power of electron cyclotron resonance Heating exceeds the threshold Power. The incremental thermal diffusivity of electron heat transport chi(inc)(e) in the ITB plasma is much lower than that in the plasma with the Heating Power below the threshold, and the thermal diffusivity chi(e) decreases with increasing of Heating Power [dchi(e)/d(P/n(e))<0] in helical ITB plasmas.
Edouard Alphandéry - One of the best experts on this subject based on the ideXlab platform.
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biodegraded magnetosomes with reduced size and Heating Power maintain a persistent activity against intracranial u87 luc mouse gbm tumors
Journal of Nanobiotechnology, 2019Co-Authors: Edouard Alphandéry, François Guyot, Ahmed Idbaih, Clovis Adam, Jean-yves Delattre, Charlotte Schmitt, Florence Gazeau, Imène ChebbiAbstract:An important but rarely addressed question in nano-therapy is to know whether bio-degraded nanoparticles with reduced sizes and weakened Heating Power are able to maintain sufficient anti-tumor activity to fully eradicate a tumor, hence preventing tumor re-growth. To answer it, we studied magnetosomes, which are nanoparticles synthesized by magnetotactic bacteria with sufficiently large sizes (~ 30 nm on average) to enable a follow-up of nanoparticle sizes/Heating Power variations under two different altering conditions that do not prevent anti-tumor activity, i.e. in vitro cellular internalization and in vivo intra-tumor stay for more than 30 days. When magnetosomes are internalized in U87-Luc cells by being incubated with these cells during 24 h in vitro, the dominant magnetosome sizes within the magnetosome size distribution (DMS) and specific absorption rate (SAR) strongly decrease from DMS ~ 40 nm and SAR ~ 1234 W/gFe before internalization to DMS ~ 11 nm and SAR ~ 57 W/gFe after internalization, a behavior that does not prevent internalized magnetosomes to efficiently destroy U87-Luc cell, i.e. the percentage of U87-Luc living cells incubated with magnetosomes decreases by 25% between before and after alternating magnetic field (AMF) application. When 2 µl of a suspension containing 40 µg of magnetosomes are administered to intracranial U87-Luc tumors of 2 mm3 and exposed (or not) to 15 magnetic sessions (MS), each one consisting in 30 min application of an AMF of 27 mT and 198 kHz, DMS and SAR decrease between before and after the 15 MS from ~ 40 nm and ~ 4 W/gFe down to ~ 29 nm and ~ 0 W/gFe. Although the magnetosome Heating Power is weakened in vivo, i.e. no measurable tumor temperature increase is observed after the sixth MS, anti-tumor activity remains persistent up to the 15th MS, resulting in full tumor disappearance among 50% of treated mice. Here, we report sustained magnetosome anti-tumor activity under conditions of significant magnetosome size reduction and complete loss of magnetosome Heating Power.
L M Team - One of the best experts on this subject based on the ideXlab platform.
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edge transport barrier modification in the l 2m stellarator depending on the Heating Power and plasma parameters
Plasma Physics and Controlled Fusion, 2006Co-Authors: G S Voronov, E V Voronova, D K Akulina, G A Gladkov, L M TeamAbstract:Boronization of the vacuum chamber of the L-2M stellarator has resulted in modification of the electron temperature profile. In particular, a well-defined jump in the electron temperature to Te ~ 100 eV in a narrow region Δr/r ~ 0.05 is observed in the temperature profile at the plasma edge. In the present paper, the value and shape of the jump in Te are studied at different values of plasma parameters and ECR Heating Power. A jump in Te is absent at a Power of P ~ 100 kW, whereas at P ~ 200 kW the electron temperature drops from 150 eV to zero within Δr ~ 0.5 cm. The value of threshold Power for the formation of a jump in Te at ne ~ 1.7 × 1019 m−3 lies within the range P ~ 100–160 kW. In terms of Power per particle this Power threshold is P/V/Ne ~ 0.2–0.3 Mw/m3/1019m−3, the value of which coincides with threshold Power for ETB formation found recently in the CHS stellarator. When the helical-field strength is 25% or 50% below its standard value, a jump in Te at the plasma edge in L-2M is absent.