Comparisons between measurements and spatially-averaged (0D) simulations of low-pressure Ar and Cl2 pulsed-plasmas in an industrial inductively coupled reactor are reported. Our analysis focuses on ...the impact of the pulsing parameters (frequency f, duty cycle dc) on the chemical reactivity of the plasma and on the ion fluxes to the walls. Charged particle densities and ion fluxes are highly modulated when the plasma is pulsed at 1 kHz < f < 20 kHz. In rare gas Ar plasmas, the ion flux rise time is short (50 μs), therefore the dc has almost no influence on the ion flux value during the pulse. By contrast, in molecular electronegative Cl2 plasmas, both the value and rise/decay time of the ion flux during the on and off-periods depend strongly on the dc. This is because in Cl2 both the plasma chemistry and electronegativity depend on the dc. During the off-period, the electron density drops much faster than the negative ion density, leading to a large increase in plasma electronegativity. A minimum afterglow time (75 µs) is required for an ion-ion plasma to form and for the sheath to collapse, exposing the walls and wafers to a negative ion flux. The positive ion flux is 3 to 10 times smaller in Cl2 than in Ar for the same operating conditions. In contrast with charged species, the radical (Cl) kinetics are slow and thus the radical density is hardly modulated for f > 1 kHz. However, the dc strongly influences the Cl2/Cl density ratio and is an excellent knob for controlling the plasma chemical reactivity: the higher the dc the higher the Cl density. The trends and quantities in the 0D simulation are in close agreement with experiments. This proves the capacity of global models to reproduce the fundamental features of pulsed plasmas in simple chemistries and to assist the development of pulsed processes.
Broad band UV–visible absorption spectroscopy is widely used to measure the concentration of radicals in reactive plasmas. We extended the applicability of this technique to the VUV (115 nm to 200 ...nm), the spectral range in which the electronic transitions from the ground state to the Rydberg or pre-dissociated states of many closed-shell molecules are located. This gives access to the absolute densities of species which do not, or weakly absorb in the UV–visible range. The technique is demonstrated by measuring the densities of HBr and Br
2
molecules in HBr high-density ICP plasmas.
This paper reviews recent progress in the development of time-resolved diagnostics to probe high-density pulsed plasma sources. We focus on time-resolved measurements of radicals' densities in the ...afterglow of pulsed discharges to provide useful information on production and loss mechanisms of free radicals. We show that broad-band absorption spectroscopy in the ultraviolet and vacuum ultraviolet spectral domain and threshold ionization modulated beam mass spectrometry are powerful techniques for the determination of the time variation of the radicals' densities in pulsed plasmas. The combination of these complementary techniques allows detection of most of the reactive species present in industrial etching plasmas, giving insights into the physico-chemistry reactions involving these species. As an example, we discuss briefly the radicals' kinetics in the afterglow of a SiCl4/Cl2/Ar discharge.
Background: Reports of doxycycline-induced toxicity are limited despite common use of this antibiotic to treat infectious respiratory disorders in calves. Objective: To describe previously unreported ...kidney lesions and diagnostic test results in doxycycline-overdosed calves and to compare these results with other findings reported previously. Animals: Thirty-two calves that presented with adverse effects after receiving high doses of doxycycline as a treatment for mild respiratory disorders. Method: Retrospective review of medical records. Results: Clinical examination identified mainly lethargy, dyspnea, cough, tongue paresia or paralysis associated with dysphagia and sialorrhea, tachycardia, tachypnea, and signs of myopathy. Blood analysis indicated increases in creatine kinase, lactate dehydrogenase, aspartate aminotransferase, and sorbitol dehydrogenase activities and increased serum creatinine and urea concentrations. ECG recordings and Doppler echocardiography examination identified ventricular premature beats and a decrease in left ventricular global and systolic function, respectively. Necropsy and histopathology disclosed necrosis of the myocardium, tongue, and some striated muscles, acute renal tubular necrosis, and fatty degeneration or congestion of the liver. Conclusions: Most of these findings corroborate previous observations made in doxycycline-overdosed calves, and further suggest myocardial and striated muscular toxicity as well as renal toxicity in doxycycline-overdosed calves.
Three randomised trials, RADICALS (ISRCTN40814031), GETUG-AFU 17 (NCT00667069) and RAVES (NCT00860652), have compared adjuvant radiotherapy (ART) with a policy of salvage radiotherapy for PSA failure ...(SRT) after radical prostatectomy for men with localised prostate cancer, but have limited power for long-term outcomes. Therefore, the ARTISTIC collaboration prospectively planned a series of meta-analyses for each outcome.
Using a framework for adaptive meta-analysis (FAME), we prospectively defined our methods, including a consistent definition of PSA-driven event-free survival (EFS), prior to knowledge of trial results (CRD42019132669). We anticipated 240 events across all trials by Autumn 2019, giving 90% power to detect a 5% absolute difference in 5-year EFS. This provided a firm basis for a meta-analysis at this time.
Across the 3 trials, 1074 men were randomised to ART and 1077 to SRT. To date, 395 men (37%) had commenced SRT. Patient characteristics were balanced within trials and overall. Men had median age of 65 years and most (77%) had a Gleason sum score of 7. Median follow-up ranged from 47 to 61 months. In August 2019, RADICALS and GETUG-AFU 17 provided EFS results for the meta-analysis (interim for GETUG-AFU 17). RAVES currently could only supply freedom from biochemical failure results. However, as the vast majority of first events across all trials are biochemical failures, these results have been pooled in a preliminary meta-analysis of EFS. Based on 245 events, the meta-analysis shows no evidence that EFS is improved with ART compared to SRT (HR=1.09, 95% CI=0.86-1.39, p=0.47). This translates to a potential absolute difference of 1% at 5 years in favour of SRT (95% CI: 2% in favour ART to 4% in favour of SRT).
This collaborative, prospective and early meta-analysis of all men from 3 randomised trials, suggests that SRT and ART offer similar outcomes for EFS. However, SRT spares many men from receiving RT, and associated side-effects. Final data from GETUG-AFU 17 and RAVES may help establish whether some subgroups of men might benefit from either treatment. Longer follow-up is needed for a meta-analysis of metastasis-free survival.
ISRCTN40814031; NCT00667069; NCT00860652.
University College London.
UK Medical Research Council.
C. Parker: Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (self), Research Funding, Speaker Fees and Advisory Board Honoraria: Bayer; Honoraria (self), Advisory / Consultancy, Advisory Board Honoraria: AAA; Honoraria (self), Speaker Bureau / Expert testimony, Speaker Fees: Janssen. M.K.B. Parmar: Research grant / Funding (institution), Unrestricted grant to contribute to another comparison of STAMPEDE which supports the protocol overall, plus relevant drug and distribution.: Astellas; Research grant / Funding (institution), Unrestricted grant to contribute to another comparison of STAMPEDE which supports the protocol overall, plus relevant drug and distribution.: Clovis Oncology; Research grant / Funding (institution), Unrestricted grant to contribute to another comparison of STAMPEDE which supports the protocol overall, plus relevant drug and distribution.: Novartis; Research grant / Funding (institution), Unrestricted grant to contribute to another comparison of STAMPEDE which supports the protocol overall, plus relevant drug and distribution.: Pfizer; Research grant / Funding (institution), Unrestricted grant to contribute to another comparison of STAMPEDE which supports the protocol overall, plus relevant drug and distribution.: Sanofi. P. Sargos: Advisory / Consultancy, Travel / Accommodation / Expenses, Non-remunerated activity/ies, Board and Meeting support: Ipsen; Advisory / Consultancy, Travel / Accommodation / Expenses, Non-remunerated activity/ies, Board and Meeting support: Takeda; Non-remunerated activity/ies, Board and Meeting support: Ferring; Advisory / Consultancy, Travel / Accommodation / Expenses, Non-remunerated activity/ies, Board and Meeting support: Astellas; Advisory / Consultancy, Travel / Accommodation / Expenses, Board and Meeting support: Recordati. M.R. Sydes: Research grant / Funding (institution), Non-remunerated activity/ies, Unrestricted grant to contribute to another comparison of STAMPEDE which supports the protocol overall, plus relevant drug and distribution.: Astellas; Research grant / Funding (institution), Non-remunerated activity/ies, Unrestricted grant to contribute to another comparison of STAMPEDE which supports the protocol overall, plus relevant drug and distribution.: Clovis Oncology; Research grant / Funding (institution), Non-remunerated activity/ies, Unrestricted grant to contribute to another comparison of STAMPEDE which supports the protocol overall, plus relevant drug and distribution.: Novartis; Non-remunerated activity/ies, Unrestricted grant to contribute to another comparison of STAMPEDE which supports the protocol overall, plus relevant drug and distribution.: Pfizer; Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses, Speaker fee for educational meeting sponsored by Eli Lilly, plus travel costs: Eli Lilly; Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses, Non-remunerated activity/ies, Unrestricted grant which contributes which supports the protocol overall, plus abiraterone and distribution for two of the STAMPEDE comparisons. Plus travel and speaker fees for two educational events (statistics lectures).: Janssen; Research grant / Funding (institution), Non-remunerated activity/ies, Unrestricted grant which contributes which supports the protocol overall, plus abiraterone and distribution for two of the STAMPEDE comparisons; Travel and speaker fees for two educational events (statistics lectures): Sanofi. All other authors have declared no conflicts of interest.
PDF
