Impurity intrusion in radio-frequency micro-plasma jets operated in ambient air

Space and time resolved concentrations of helium metastable atoms in an atmospheric pressure radio-frequency micro-plasma jet were measured using tunable diode laser absorption spectroscopy. Spatial profiles as well as lifetime measurements show significant influences of air entering the discharge from the front nozzle and of impurities originating from the gas supply system. Quenching of metastables was used to deduce quantitative concentrations of intruding impurities. The impurity profile along the jet axis was determined from optical emission spectroscopy as well as their dependance on the feed gas flow through the jet.Comment: Journal of Physics D: Applied Physics (accepted), 6 page

Summer 1981

Editorial (page 3) Results of Field Test to Study Human Exposure to 2,4,5,-T Application (4) Investigation and Treatment of Localized Dry Spots on Sand Golf Greens (6) Aquatic Weed Control- In Review (11) Golf Course Superintendent - A Perspective (14) Four Seasons Ground Maintenance (16

Spatially resolved simulation of a radio frequency driven micro atmospheric pressure plasma jet and its effluent

Radio frequency driven plasma jets are frequently employed as efficient plasma sources for surface modification and other processes at atmospheric pressure. The radio-frequency driven micro atmospheric pressure plasma jet ($\mu$APPJ) is a particular variant of that concept whose geometry allows direct optical access. In this work, the characteristics of the $\mu$APPJ operated with a helium-oxygen mixture and its interaction with a helium environment are studied by numerical simulation. The density and temperature of the electrons, as well as the concentration of all reactive species are studied both in the jet itself and in its effluent. It is found that the effluent is essentially free of charge carriers but contains a substantial amount of activated oxygen (O, O$_3$ and O$_2(^1\Delta)$). The simulation results are verified by comparison with experimental data

Non-invasive vagus nerve stimulation in epilepsy patients enhances cooperative behavior in the prisoner's dilemma task

The vagus nerve constitutes a key link between the autonomic and the central nervous system. Previous studies provide evidence for the impact of vagal activity on distinct cognitive processes including functions related to social cognition. Recent studies in animals and humans show that vagus nerve stimulation is associated with enhanced reward-seeking and dopamine-release in the brain. Social interaction recruits similar brain circuits to reward processing. We hypothesize that vagus nerve stimulation (VNS) boosts rewarding aspects of social behavior and compare the impact of transcutaneous VNS (tVNS) and sham stimulation on social interaction in 19 epilepsy patients in a double-blind pseudo-randomized study with cross-over design. Using a well-established paradigm, i.e., the prisoner's dilemma, we investigate effects of stimulation on cooperative behavior, as well as interactions of stimulation effects with patient characteristics. A repeated-measures ANOVA and a linear mixed-effects model provide converging evidence that tVNS boosts cooperation. Post-hoc correlations reveal that this effect varies as a function of neuroticism, a personality trait linked to the dopaminergic system. Behavioral modeling indicates that tVNS induces a behavioral starting bias towards cooperation, which is independent of the decision process. This study provides evidence for the causal influence of vagus nerve activity on social interaction

An Analysis of Resting-State Functional Transcranial Doppler Recordings from Middle Cerebral Arteries

Functional transcrannial Doppler (fTCD) is used for monitoring the hemodynamics characteristics of major cerebral arteries. Its resting-state characteristics are known only when considering the maximal velocity corresponding to the highest Doppler shift (so called the envelope signals). Significantly more information about the resting-state fTCD can be gained when considering the raw cerebral blood flow velocity (CBFV) recordings. In this paper, we considered simultaneously acquired envelope and raw CBFV signals. Specifically, we collected bilateral CBFV recordings from left and right middle cerebral arteries using 20 healthy subjects (10 females). The data collection lasted for 15 minutes. The subjects were asked to remain awake, stay silent, and try to remain thought-free during the data collection. Time, frequency and time-frequency features were extracted from both the raw and the envelope CBFV signals. The effects of age, sex and body-mass index were examined on the extracted features. The results showed that the raw CBFV signals had a higher frequency content, and its temporal structures were almost uncorrelated. The information-theoretic features showed that the raw recordings from left and right middle cerebral arteries had higher content of mutual information than the envelope signals. Age and body-mass index did not have statistically significant effects on the extracted features. Sex-based differences were observed in all three domains and for both, the envelope signals and the raw CBFV signals. These findings indicate that the raw CBFV signals provide valuable information about the cerebral blood flow which can be utilized in further validation of fTCD as a clinical tool. © 2013 Sejdić et al

Diffusion tensor imaging of Parkinson's disease, multiple system atrophy and progressive supranuclear palsy: a tract-based spatial statistics study

Although often clinically indistinguishable in the early stages, Parkinson's disease (PD), Multiple System Atrophy (MSA) and Progressive Supranuclear Palsy (PSP) have distinct neuropathological changes. The aim of the current study was to identify white matter tract neurodegeneration characteristic of each of the three syndromes. Tract-based spatial statistics (TBSS) was used to perform a whole-brain automated analysis of diffusion tensor imaging (DTI) data to compare differences in fractional anisotropy (FA) and mean diffusivity (MD) between the three clinical groups and healthy control subjects. Further analyses were conducted to assess the relationship between these putative indices of white matter microstructure and clinical measures of disease severity and symptoms. In PSP, relative to controls, changes in DTI indices consistent with white matter tract degeneration were identified in the corpus callosum, corona radiata, corticospinal tract, superior longitudinal fasciculus, anterior thalamic radiation, superior cerebellar peduncle, medial lemniscus, retrolenticular and anterior limb of the internal capsule, cerebral peduncle and external capsule bilaterally, as well as the left posterior limb of the internal capsule and the right posterior thalamic radiation. MSA patients also displayed differences in the body of the corpus callosum corticospinal tract, cerebellar peduncle, medial lemniscus, anterior and superior corona radiata, posterior limb of the internal capsule external capsule and cerebral peduncle bilaterally, as well as the left anterior limb of the internal capsule and the left anterior thalamic radiation. No significant white matter abnormalities were observed in the PD group. Across groups, MD correlated positively with disease severity in all major white matter tracts. These results show widespread changes in white matter tracts in both PSP and MSA patients, even at a mid-point in the disease process, which are not found in patients with PD

Spectroscopic characterization of atmospheric pressure um-jet plasma source

A radio frequency um-jet plasma source is studied using He/O2 mixture. This um-jet can be used for different applications as a source of chemical active species e.g. oxygen atoms, molecular metastables and ozone. Using absolutely-calibrated optical emission spectroscopy and numerical simulation, the gas temperature in active plasma region and plasma parameters (electron density and electron distribution function) are determined. Concentrations of oxygen atoms and ozone in the plasma channel and in the effluent of the plasma source are measured using emission and absorption spectroscopy. To interpret the measured spatial distributions, the steady-state species' concentrations are calculated using determined plasma parameters and gas temperature. At that the influence of the surface processes and gas flow regime on the loss of the active species in the plasma source are discussed. The measured spatial distributions of oxygen atom and ozone densities are compared with the simulated ones.Comment: 29 pages, 10 figure

Factors predicting cessation of status epilepticus in clinical practice: Data from a prospective observational registry (SENSE).

To investigate the initial termination rate of status epilepticus (SE) in a large observational study and explore associated variables. Data of adults treated for SE were collected prospectively in centers in Germany, Austria, and Switzerland, during 4.5 years. Incident episodes of 1,049 patients were analyzed using uni- and multivariate statistics to determine factors predicting cessation of SE within 1 hour (for generalized convulsive SE [GCSE]) and 12 hours (for non-GCSE) of initiating treatment. Median age at SE onset was 70 years; most frequent etiologies were remote (32%) and acute (31%). GCSE was documented in 43%. Median latency between SE onset and first treatment was 30 minutes in GCSE and 150 minutes in non-GCSE. The first intravenous compound was a benzodiazepine in 86% in GCSE and 73% in non-GCSE. Bolus doses of the first treatment step were lower than recommended by current guidelines in 76% of GCSE patients and 78% of non-GCSE patients. In 319 GCSE patients (70%), SE was ongoing 1 hour after initiating treatment and in 342 non-GCSE patients (58%) 12 hours after initiating treatment. Multivariate Cox regression demonstrated that use of benzodiazepines as first treatment step and a higher cumulative dose of anticonvulsants within the first period of treatment were associated with shorter time to cessation of SE for both groups. In clinical practice, treatment guidelines were not followed in a substantial proportion of patients. This underdosing correlated with lack of cessation of SE. Our data suggest that sufficiently dosed benzodiazepines should be used as a first treatment step. ANN NEUROL 2019;85:421-432