Effects of Non-Thermal Plasma on Mammalian Cells

Thermal plasmas and lasers have been widely used in medicine to cut, ablate and cauterize tissues through heating; in contrast, non-thermal plasma produces no heat, so its effects can be selective. In order to exploit the potential for clinical applications, including wound healing, sterilization, blood coagulation, and cancer treatment, a mechanistic understanding of the interaction of non-thermal plasma with living tissues is required. Using mammalian cells in culture, it is shown here that non-thermal plasma created by dielectric barrier discharge (DBD) has dose-dependent effects that range from increasing cell proliferation to inducing apoptosis. It is also shown that these effects are primarily due to formation of intracellular reactive oxygen species (ROS). We have utilized γ-H2AX to detect DNA damage induced by non-thermal plasma and found that it is initiated by production of active neutral species that most likely induce formation of organic peroxides in cell medium. Phosphorylation of H2AX following non-thermal plasma treatment is ATR dependent and ATM independent, suggesting that plasma treatment may lead to replication arrest or formation of single-stranded DNA breaks; however, plasma does not lead to formation of bulky adducts/thymine dimers

Association between number and type of tooth loss on Oral Health Related Quality of life in 35-44 year olds in southeastern Iran.

Oral diseases can affect oral health related quality of life (OHRQol). The aim of the present study was to determine the association between the number and type of tooth loss on OHRQol in 35-44 year old individuals. This cross-sectional descriptive study conducted on 400, 35-44 year old people who visited Kerman clinics. Data were collected by using demographic and oral health behavior questionnaires, clinical examination (DMFT index) and the OHRQol questionnaire (OHIP-14). Data were analyzed in SPSS18, by t-test, X2 at 5% significance level. In the present study 206 (51.5%) were men, the mean age was 39.22±4.98 years and 52.0% had university education. The mean of DMFT and OHIP-14 scores were 13.3±4.5 and 18.6±8.3 (from 56) respectively. Men had lower OHRQol than women, but the difference was not significant. There was significant relation between educational level, oral health behavior, number and type of tooth loss and the OHRQol score. OHRQol was acceptable in this study and had a significant correlation with number and type of tooth loss. Further studies on other age groups is recommended. Keywords: oral health، quality of life, tooth loss, type of tooth loss, 35-44 years old، southeastern Iran

A multi-stage stochastic programming approach for blood supply chain planning

International audienc

Statistical Analysis of Displacement and Length Relation for Normal Faults in the Barents Sea

This paper is devoted to the statistical analysis of dependence between fault length (L) and displacement (D). The main purpose of this work is to study the scaling relations between fault length and displacement using a database that includes datasets of 21 faults with geometric data extracted from 3D seismic coherence cubes of the Norwegian Barents Sea. Multiple linear regression and Bayesian and Akaike information criterions are applied to obtain optimal regression parameters. Our dataset is unique since it includes segment lengths of individual faults, unlike the previously published datasets. Hence, we studied both the dependence of fault segment length and accumulated fault length on displacement. The latter relation (accumulated fault length versus displacement) shows a general agreement (positive correlation and power-law relation) with the previously published results that are mainly obtained from outcrop studies, although the slopes vary for different lithologies. The differences could be attributed to the unique characteristics of our dataset that includes data of all segment lengths of individual faults

RAM analysis of earth pressure balance tunnel boring machines: A case study

Earth pressure balance tunnel boring machines (EPB-TBMs) are favorably applied in urban tunneling projects. Despite their numerous advantages, considerable delays and high maintenance cost are the main disadvantages these machines suffer from. Reliability, availability, and maintainability (RAM) analysis is a practical technique that uses failure and repair dataset obtained over a reasonable time for dealing with proper machine operation, maintenance scheduling, cost control, and improving the availability and performance of such machines. In the present study, a database of failures and repairs of an EBP-TBM was collected in line 1 of Tabriz subway project over a 26-month interval of machine operation. In order to model the reliability of the TBM, this machine was divided into five distinct subsystems including mechanical, electrical, hydraulic, pneumatic, and water systems in a series configuration. According to trend and serial correlation tests, the renewal processes were applied, for analysis of all subsystems. After calculating the reliability and maintainability functions for all subsystems, it was revealed that the mechanical subsystem with the highest failure frequency has the lowest reliability and maintainability. Similarly, estimating the availability of all subsystems indicated that the mechanical subsystem has a relatively low availability level of 52.6%, while other subsystems have acceptable availability level of 97%. Finally, the overall availability of studied machine was calculated as 48.3%.Godkänd;2021;Nivå 0;2021-10-08 (alebob)</p

Non-thermal plasma induces apoptosis in melanoma cells via production of intracellular reactive oxygen species

Abstract-Non-thermal atmospheric pressure dielectric barrier discharge (DBD) plasma may provide a novel approach to treat malignancies via induction of apoptosis. The purpose of this study was to evaluate the potential of DBD plasma to induce apoptosis in melanoma cells. Melanoma cells were exposed to plasma at doses that did not induce necrosis, and cell viability and apoptotic activity were evaluated by Trypan blue exclusion test, Annexin-V/PI staining, caspase-3 cleavage, and TUNEL Ò analysis. Trypan blue staining revealed that non-thermal plasma treatment significantly decreased the viability of cells in a dose-dependent manner 3 and 24 h after plasma treatment. Annexin-V/PI staining revealed a significant increase in apoptosis in plasma-treated cells at 24, 48, and 72 h post-treatment (p &lt; 0.001). Caspase-3 cleavage was observed 48 h post-plasma treatment at a dose of 15 J/cm 2 . TUNEL Ò analysis of plasma-treated cells demonstrated an increase in apoptosis at 48 and 72 h post-treatment (p &lt; 0.001) at a dose of 15 J/cm 2 . Pre-treatment with N-acetyl-L-cysteine (NAC), an intracellular reactive oxygen species (ROS) scavenger, significantly decreased apoptosis in plasma-treated cells at 5 and 15 J/cm 2 . Plasma treatment induces apoptosis in melanoma cells through a pathway that appears to be dependent on production of intracellular ROS. DBD plasma production of intracellular ROS leads to dosedependent DNA damage in melanoma cells, detected by c-H2AX, which was completely abrogated by pre-treating cells with ROS scavenger, NAC. Plasma-induced DNA damage in turn may lead to the observed plasma-induced apoptosis. Since plasma is non-thermal, it may be used to selectively treat malignancies