Comparison of three radio-frequency discharge modes on the treatment of breast cancer cells in vitro

Non-thermal plasmas (NTPs) are known for their ability to induce thermal-free cytotoxic effects on cancer cells. However, as the variety of NTP devices increases, comparison of their cytotoxic effect becomes increasingly essential. In this work, we compare the cytotoxicity of three different radio-frequency NTPs. MDA-MB-231 triple negative breast cancer cells are treated in suspension in DMEM culture medium by the effluents of a single radiofrequency (RF) discharge device operating in three modes, namely the and modes of the capacitively coupled radio-frequency (CCRF) discharge and a RF plasma jet mode. All three discharge modes reduce the proliferative capacity of MDA-MB-231 cells, but the treatment time required to reach the same efficacy is more than ten times longer using the and the modes than using the jet mode. In all cases, using the appropriate treatment time, cells exhibit an impaired proliferation and eventually start to show signs of cell death (about 48 h after treatment). The three discharge modes also induce nuclear DNA damages. Plasma-produced H2O2 was not found to contribute to the cytotoxicity of the treatment. Furthermore, short-lived reactive species (gas phase or liquid phase species with a lifetime below 1 s) are expected to play a dominant role over the long-lived reactive species in the anti-cancer effect of all three discharge modes

NanoWalker: a fully autonomous highly integrated miniature robot for nanoscale measurements

The aim of this project is to develop the smallest and most sophisticated wireless fully autonomous instrumented robot capable of subatomic movements. The robot named 'NanoWalker' should bring a new paradigm in the way instruments are built while providing a sophisticated platform for a new range of applications. The project involves primarily the investigation of a new legged locomotion based on piezo-actuators with advanced micro-assembly techniques applied to complex embedded electronic systems; the development of new miniature instruments, micro-manipulators, integrated behavior for controlling, searching and scanning at the atomic scale; and the development of a subatomic navigation system. Besides all the new technologies and techniques that we intend to develop and which will be applicable to many areas and systems, the NanoWalker should provide a suitable yet more flexible and powerful platform compared to traditional macro-scaled instruments. It is anticipated that this new form of highly integrated autonomous microsystem will be used as the main building block for a new generation of measurement and inspection systems. In this paper, the main components of the NanoWalker are briefly described.Seaver Institut

Regional Brain Stem Atrophy in Idiopathic Parkinson's Disease Detected by Anatomical MRI

Idiopathic Parkinson's disease (PD) is a neurodegenerative disorder characterized by the dysfunction of dopaminergic dependent cortico-basal ganglia loops and diagnosed on the basis of motor symptoms (tremors and/or rigidity and bradykinesia). Post-mortem studies tend to show that the destruction of dopaminergic neurons in the substantia nigra constitutes an intermediate step in a broader neurodegenerative process rather than a unique feature of Parkinson's disease, as a consistent pattern of progression would exist, originating from the medulla oblongata/pontine tegmentum. To date, neuroimaging techniques have been unable to characterize the pre-symptomatic stages of PD. However, if such a regular neurodegenerative pattern were to exist, consistent damages would be found in the brain stem, even at early stages of the disease. We recruited 23 PD patients at Hoenn and Yahr stages I to II of the disease and 18 healthy controls (HC) matched for age. T1-weighted anatomical scans were acquired (MPRAGE, 1 mm3 resolution) and analyzed using an optimized VBM protocol to detect white and grey matter volume reduction without spatial a priori. When the HC group was compared to the PD group, a single cluster exhibited statistical difference (p<0.05 corrected for false detection rate, 4287 mm3) in the brain stem, between the pons and the medulla oblongata. The present study provides in-vivo evidence that brain stem damage may be the first identifiable stage of PD neuropathology, and that the identification of this consistent damage along with other factors could help with earlier diagnosis in the future. This damage could also explain some non-motor symptoms in PD that often precede diagnosis, such as autonomic dysfunction and sleep disorders

Wringing out DNA

The chiral nature of DNA plays a crucial role in cellular processes. Here we use magnetic tweezers to explore one of the signatures of this chirality, the coupling between stretch and twist deformations. We show that the extension of a stretched DNA molecule increases linearly by 0.42 nm per excess turn applied to the double helix. This result contradicts the intuition that DNA should lengthen as it is unwound and get shorter with overwinding. We then present numerical results of energy minimizations of torsionally restrained DNA that display a behaviour similar to the experimental data and shed light on the molecular details of this surprising effect.Comment: 4 pages revtex4, 4 figure

Synergy between Non-Thermal Plasma with Radiation Therapy and Olaparib in a Panel of Breast Cancer Cell Lines

Cancer therapy has evolved to a more targeted approach and often involves drug combinations to achieve better response rates. Non-thermal plasma (NTP), a technology rapidly expanding its application in the medical field, is a near room temperature ionized gas capable of producing reactive species, and can induce cancer cell death both in vitro and in vivo. Here, we used proliferation assay to characterize the plasma sensitivity of fourteen breast cancer cell lines. These assays showed that all tested cell lines were sensitive to NTP. In addition, a good correlation was found comparing cell sensitivity to NTP and radiation therapy (RT), where cells that were sensitive to RT were also sensitive to plasma. Moreover, in some breast cancer cell lines, NTP and RT have a synergistic effect. Adding a dose of PARP-inhibitor olaparib to NTP treatment always increases the efficacy of the treatment. Olaparib also exhibits a synergistic effect with NTP, especially in triple negative breast cancer cells. Results presented here help elucidate the position of plasma use as a potential breast cancer treatment

Anisotropic and low damage III-V/Ge heterostructure etching for multijunction solar cell fabrication with passivated sidewalls

International audienc

Patterns of longitudinal neural activity linked to different cognitive profiles in Parkinson’s disease

Mild cognitive impairment in Parkinson’s disease (PD) has been linked with functional brain changes. Previously, using functional magnetic resonance imaging (fMRI), we reported reduced cortico-striatal activity in patients with PD who also had mild cognitive impairment (MCI) versus those who did not (non-MCI). We followed up these patients to investigate the longitudinal effect on the neural activity. Twenty-four non-demented patients with Parkinson’s disease (non-MCI: 12, MCI; 12) were included in the study. Each participant underwent two fMRIs while performing the Wisconsin Card Sorting Task 20 months apart. The non-MCI patients recruited the usual cognitive corticostriatal loop at the first and second sessions (Time 1 and Time 2, respectively). However, decreased activity was observed in the cerebellum and occipital area and increased activity was observed in the medial prefrontal cortex and parietal lobe during planning set-shift at Time 2. Increased activity in the precuneus was also demonstrated while executing set-shifts at Time 2. The MCI patients revealed more activity in the frontal, parietal and occipital lobes during planning set-shifts, and in the parietal and occipital lobes, precuneus, and cerebellum, during executing set-shift at Time 2. Analysis regrouping of both groups of PD patients revealed that hippocampal and thalamic activity at Time 1 was associated with less cognitive decline over time. Our results reveal that functional alteration along the time-points differed between the non-MCI and MCI patients. They also underline the importance of preserving thalamic and hippocampal function with respect to cognitive decline over time