Effects of Pulse Width on He Plasma Jets in Contact with Water Evaluated by OH(A-X) Emission and OHaq Production

Nanosecond pulsed helium plasma jets impinging on water produce hydroxyl radicals both in gas- and liquid-phase. In this study, the effects of pulse width on a repetitively pulsed plasma jet in contact with water are evaluated via OH(A-X) emission and OHaq production in water for various pulse widths ranging from 200 to 5000 ns. The maximal energy efficiency of OH(A-X) emission is obtained for pulse widths of 600-800 ns whereas the maximal efficiency of OHaq production is at 200 ns. Temporally-resolved emission spectroscopy shows that more than 40% of OH(A-X) emission is produced during the first 200 ns of the voltage pulse regardless of the pulse width. An equivalent circuit model of the plasma jet impinging on water is compiled to understand the charge transfer process, which is important for OHaq production via charge exchange reactions

The production of OH in a nanosecond pulsed helium plasma jet impinging on water, saline, or pigskin

Applications of plasma-induced biological effects via reactive oxygen and nitrogen species (RONS) make the non-thermal atmospheric-pressure plasma jets an appealing tool in biomedical fields. The presence of biological materials, especially as part of the electrode circuit, may change the plasma properties and impact on the production of RONS at the plasma-biomaterial interface. Effects of biomaterials on the production of hydroxyl radicals (OH) in a nanosecond pulsed, atmospheric-pressure plasma jet were investigated using a needle-to-plate electrode configuration with water, phosphate-buffered saline (PBS), or pigskin covering the ground plate. Driven by 200 ns, 7 kV pulses at 1 kHz, a helium plasma jet was generated between the hollow needle electrode and the biomaterial. Temporally resolved UV-visible imaging showed that the use of pigskin slowed down the streamer head propagation, whereas a more pronounced surface ionization wave was developed on the surface when water was used. The highest OH(A-X) emission above the biomaterial surface was observed using the PBS-covered electrode plate comparing to water or pigskin. Spatiotemporally resolved laser-induced fluorescence (LIF) showed that more OH was produced in the region near the needle electrode for both water and PBS, and the use of pigskin resulted in least OH production overall. In addition, measurements of H2O2 production in the liquid were used to determine the OH concentration in the vicinity of the biomaterial and agreed well with the relative OH-LIF measurements obtained at the gas-liquid interface for water and PBS

Exploiting Multiple Embeddings for Chinese Named Entity Recognition

Identifying the named entities mentioned in text would enrich many semantic applications at the downstream level. However, due to the predominant usage of colloquial language in microblogs, the named entity recognition (NER) in Chinese microblogs experience significant performance deterioration, compared with performing NER in formal Chinese corpus. In this paper, we propose a simple yet effective neural framework to derive the character-level embeddings for NER in Chinese text, named ME-CNER. A character embedding is derived with rich semantic information harnessed at multiple granularities, ranging from radical, character to word levels. The experimental results demonstrate that the proposed approach achieves a large performance improvement on Weibo dataset and comparable performance on MSRA news dataset with lower computational cost against the existing state-of-the-art alternatives.Comment: accepted at CIKM 201

Modulation of ROS in Nanosecond-Pulsed Plasma-Activated Media for Dosage-Dependent Cancer Cell Inactivation \u3ci\u3ein vitro\u3c/i\u3e

Dosage control of reactive oxygen and nitrogen species (RONS) is critical to low-temperature plasma applications in cancer therapy. Production of RONS by atmospheric pressure, nonequilibrium plasmas in contact with liquid may be modulated via plasma conditions including plasma treatment time and pulse voltage and repetition frequency. In this study, a terephthalic acid-based probe was used to measure hydroxyl radicals [OHaq] in water exposed to plasma and to demonstrate that the OHag concentration increases linearly with treatment time. Fluorometric measurements of hydrogen peroxide concentration in plasma-activated water show a linear relationship between the H2O2 production rate and the pulse repetition frequency of the plasma. In vitro plasma treatment of cancer cells shows that pancreatic (Pan02) and breast (4T1-Luc) cancer cells have different sensitivities to plasma exposure. The dependence of Pan02 cell viability on plasma treatment time or pulse voltage is nonlinear. The system described here for generation and delivery of reactive oxygen species from a nanosecond pulsed plasma jet represents a promising alternative approach to cancer therapy

Investigation of hemostatic effect of Spleen-invigorating, Qi-replenishing and Blood-arresting Formula on simvastatin-induced zebrafish hemorrhage model

Objective: To observe the hemostatic effect of the Spleen-invigorating, Qi-replenishing and Blood-arresting Formula on simvastatin-induced zebrafish hemorrhage model compared with that of the Heat-clearing and Blood-cooling Formula. Methods: AB strain wild type zebrafish were treated with 0.5 μM simvastatin for 24 hours to establish the zebrafish hemorrhage model. Under strictly blind experimental conditions, the zebrafish were then treated with experimental agents in different concentration within the maximum non-lethal dose. The intervention effect of the Spleen-invigorating, Qi-replenishing and Blood-arresting Formula was comprehensively assessed by examining the main observational parameters such as the bleeding reduction rate and hemostatic rate while referring to the additional parameters such as blood flow, improvement rate of blood flow, velocity of movement, improvement rate of motion under spleen-qi deficiency. Results: Hemostatic effect: The bleeding rate and hemostatic rate in the zebrafish were respectively, 30%, 15%, 45%, 40% and 60%, 80%, 40%, 47% when equal concentration of 500 μg/mL, 1000 μg/mL were used. This showed that the experimental herbs B1 was superior to B2 in decreasing the bleeding rate and improving hemostatic effect in the zebrafish. Improvement of blood flow: With equal concentration, the experimental herb B1 was superior to B2 in increasing the blood flow and improvement rate of blood flow in hemorrhagic zebrafish. Promotion of the improvement of motion: With equal concentration of 500 μg/mL and 1000 μg/mL, the experimental herb B1 was superior to B2 in promoting the velocity of motion in the zebrafish and promoting the improvement rate of motion. Conclusion: The manifestations of simvastatin-induced zebrafish hemorrhage are basically similar to that of failure of the spleen to control blood in human beings. The Spleen-invigorating, Qi-replenishing and Blood-arresting Formula has good hemostatic effect on simvastatin-induced hemorrhage in the zebrafish. It also boasts the functions of improving blood flow and velocity of motion in the hemorrhagic zebrafish. Such a conclusion provides the experimental basis for the treatment of the syndrome of failure of the spleen to control blood by this formula

Prediction of Wheat Grain Protein by Coupling Multisource Remote Sensing Imagery and ECMWF Data

Industrialization production with high quality and effect on winter is an important measure for accelerating the shift from increasing agricultural production to improving quality in terms of grain protein content (GPC). Remote sensing technology achieved the GPC prediction. However, large deviations in interannual expansion and regional transfer still exist. The present experiment was carried out in wheat producing areas of Beijing (BJ), Renqiu (RQ), Quzhou, and Jinzhou in Hebei Province. First, the spectral consistency of Landsat 8 Operational Land Imager (LS8) and RapidEye (RE) was compared with Sentinel-2 (S2) satellites at the same ground point in the same period. The GPC prediction model was constructed by coupling the vegetation index with the meteorological data obtained by the European Center for Medium-range Weather Forecasts using hierarchical linear model (HLM) method. The prediction and spatial expansion of regional GPC were validated. Results were as follows: (1) Spectral information calculated from S2 imagery were highly consistent with LS8 (R2 = 1.00) and RE (R2 = 0.99) imagery, which could be jointly used for GPC modeling. (2) The predicted GPC by using the HLM method (R2 = 0.524) demonstrated higher accuracy than the empirical linear model (R2 = 0.286) and showed higher improvements across inter-annual and regional scales. (3) The GPC prediction results of the verification samples in RQ, BJ, Xiaotangshan (XTS) in 2018, and XTS in 2019 were ideal with root mean square errors of 0.61%, 1.13%, 0.91%, and 0.38%, and relative root mean square error of 4.11%, 6.83%, 6.41%, and 2.58%, respectively. This study has great application potential for regional and inter-annual quality prediction