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Scientific Reports Jul 2023Gutta-percha's lack of adhesion has been presented as a drawback to avoid gaps at sealer/gutta-percha interface. Plasma treatments have been scarcely assessed on...
Gutta-percha's lack of adhesion has been presented as a drawback to avoid gaps at sealer/gutta-percha interface. Plasma treatments have been scarcely assessed on gutta-percha surfaces as a method of enhancing adhesiveness. This study aimed to evaluate the effect of low-pressure Argon and Oxygen plasma atmospheres on conventional and bioceramic gutta-percha standardized smooth discs, assessing their roughness, surface free energy, chemical structure, and sealer wettability. A Low-Pressure Plasma Cleaner by Diener Electronic (Zepto Model) was used. Different gases (Argon or Oxygen), powers (25 W, or 50 W), and exposure times (30 s, 60 s, 120 s, or 180 s) were tested in control and experimental groups. Kruskal-Wallis and Student's t-test were used in data analysis. Statistically significant differences were detected when P < 0.05. Both gases showed different behaviors according to the parameters selected. Even though chemical changes were detected, the basic molecular structure was maintained. Argon or Oxygen plasma treatments favoured the wetting of conventional and bioceramic gutta-perchas by Endoresin and AH Plus Bioceramic sealers (P < 0.001). Overall, the functionalization of gutta-percha surfaces with Argon or Oxygen plasma treatments can increase roughness, surface free energy and wettability, which might improve its adhesive properties when compared to non-treated gutta-percha.
Topics: Humans; Adhesiveness; Argon; Gutta-Percha; Gases; Oxygen
PubMed: 37516768
DOI: 10.1038/s41598-023-37372-x -
International Journal of Infectious... Oct 2022Mask usage has increased over the last few years due to the COVID-19 pandemic, resulting in a mask shortage. Furthermore, their prolonged use causes skin problems...
OBJECTIVES
Mask usage has increased over the last few years due to the COVID-19 pandemic, resulting in a mask shortage. Furthermore, their prolonged use causes skin problems related to bacterial overgrowth. To overcome these problems, atmospheric pressure cold plasma was studied as an alternative technology for mask disinfection.
METHODS
Different microorganisms (Pseudomonas aeruginosa, Escherichia coli, Staphylococcus spp.), different gases (nitrogen, argon, and air), plasma power (90-300 W), and treatment times (45 seconds to 5 minutes) were tested.
RESULTS
The best atmospheric pressure cold plasma treatment was the one generated by nitrogen gas at 300 W and 1.5 minutes. Testing of breathing and filtering performance and microscopic and visual analysis after one and five plasma treatment cycles, highlighted that these treatments did not affect the morphology or functional capacity of the masks.
CONCLUSION
Considering the above, we strongly believe that atmospheric pressure cold plasma could be an inexpensive, eco-friendly, and sustainable mask disinfection technology enabling their reusability and solving mask shortage.
Topics: Argon; Atmospheric Pressure; COVID-19; Disinfection; Escherichia coli; Humans; Nitrogen; Pandemics; Plasma Gases
PubMed: 35995313
DOI: 10.1016/j.ijid.2022.08.012 -
Journal of Applied Physiology... May 2022Multiple breath washout (MBW) testing is increasingly used as a physiological measurement in the clinic, due in part to the availability of commercial equipment and...
Multiple breath washout (MBW) testing is increasingly used as a physiological measurement in the clinic, due in part to the availability of commercial equipment and reference values for MBW indices. Commercial N washout devices are usually based on indirect measurement of N concentration (), by directly measuring either molar mass and O and CO, or molar mass and CO. We aim to elucidate the role of two potential pitfalls associated with N-MBW testing that could override its physiological content: indirect N measurement and blood-solubility of N. We performed MBW in 12 healthy adult subjects using a commercial device (MBW) with simultaneous direct gas concentration measurements by mass spectrometry (MBW) and compared between MBW and MBW. We also measured argon concentration during the same washouts to verify the maximal effect gas solubility can have on N-based functional residual capacity (FRC) and lung clearance index (LCI). Continuous N concentration traces were very similar for MBW and MBW, resulting in comparable breath-by-breath washout plots of expired concentration and in no significant differences in FRC, LCI, S, and S between the two methods. Argon washouts were slightly slower than N washouts, as expected for a less diffusive and more soluble gas. Finally, comparison between LCI and LCI indicates that the maximum impact from blood-tissue represents less than half a LCI unit in normal subjects. In conclusion, we have demonstrated by direct measurement of N and twice as soluble argon, that indirect N measurement can be safely used as a meaningful physiological measurement. The physiological content of N multibreath washout testing has been questioned due to N indirect measurement accuracy and N blood solubility. With direct measurement of N and twice as soluble argon, we show that these effects are largely outweighed by ease of use.
Topics: Adult; Argon; Biomarkers; Breath Tests; Carbon Dioxide; Humans; Lung; Nitrogen
PubMed: 35446597
DOI: 10.1152/japplphysiol.00511.2021 -
Brazilian Dental Journal 2022To evaluate the flexural strength (FS) and flexural modulus (FM) of a commercial 3Y-TZ0P ceramic after artificial aging and either without or with two application times...
To evaluate the flexural strength (FS) and flexural modulus (FM) of a commercial 3Y-TZ0P ceramic after artificial aging and either without or with two application times of non-thermal plasma treatments (NTP). In addition, changes in crystalline phase transformation and surface nano-topography after NTP application, during different aging periods, were evaluated. Ninety 3Y-TZP bars (45x4x3 mm) were made for FS and FM testing, and assigned to nine groups (n=10): no NTP/no aging (Control); no NTP/4h aging; no NTP/30h aging; 10s NTP/no aging; 10s NTP/4h aging; 10s NTP/30h aging; 60s NTP/no aging; 60s NTP/4h aging and 60s NTP/30h aging. Artificial accelerated aging was simulated using an autoclave (134º C at 2 bar) for up to 30h. FS and FM were assessed using a universal testing machine and data analyzed using a ANOVA and Tukey test (α=0.05). The volume change in zirconia monoclinic phase (MPV) was evaluated using X-ray diffraction and surface nano-topography was assessed using atomic force microscopy (baseline until 30h-aging). NTP application did not influence the FS and FM of zirconia. Compared to the Control (no NTP/no aging), the FS of zirconia samples treated for 30 hours in autoclave ("no NTP/30h aging" group) increased. Artificial aging for 30 hours significantly increased the FM of zirconia, regardless of NTP application. MPV tended to increase following the increase in aging time, which might result in the surface irregularities observed at 30h-aging. NTP did not alter the zirconia properties tested, but 30h-aging can change the zirconia FS, FM and MPV.
Topics: Plasma Gases; Dental Materials; Argon; Materials Testing; Surface Properties; Zirconium; Ceramics; Yttrium
PubMed: 36287491
DOI: 10.1590/0103-6440202204849 -
The Cochrane Database of Systematic... Aug 2022Open-angle glaucoma (OAG) is an important cause of blindness worldwide. Laser trabeculoplasty, a treatment modality, still does not have a clear position in the... (Review)
Review
BACKGROUND
Open-angle glaucoma (OAG) is an important cause of blindness worldwide. Laser trabeculoplasty, a treatment modality, still does not have a clear position in the treatment sequence.
OBJECTIVES
To assess the effects of laser trabeculoplasty for treating OAG and ocular hypertension (OHT) when compared to medication, glaucoma surgery or no intervention. We also wished to compare the effectiveness of different laser trabeculoplasty technologies for treating OAG and OHT.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2021, Issue 10); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; LILACS, ClinicalTrials.gov and the WHO ICTRP. The date of the search was 28 October 2021. We also contacted researchers in the field.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) comparing laser trabeculoplasty with no intervention, with medical treatment, or with surgery in people with OAG or OHT. We also included trials comparing different types of laser trabeculoplasty technologies.
DATA COLLECTION AND ANALYSIS
We used standard methods expected by Cochrane. Two authors screened search results and extracted data independently. We considered the following outcomes at 24 months: failure to control intraocular pressure (IOP), failure to stabilise visual field progression, failure to stabilise optic neuropathy progression, adverse effects, quality of life, and costs. We graded the 'certainty' of the evidence using GRADE.
MAIN RESULTS
We included 40 studies (5613 eyes of 4028 people) in this review. The majority of the studies were conducted in Europe and in the USA. Most of the studies were at risk of performance and/or detection bias as they were unmasked. None of the studies were judged as having low risk of bias for all domains. We did not identify any studies of laser trabeculoplasty alone versus no intervention. Laser trabeculoplasty versus medication Fourteen studies compared laser trabeculoplasty with medication in either people with primary OAG (7 studies) or primary or secondary OAG (7 studies); five of the 14 studies also included participants with OHT. Six studies used argon laser trabeculoplasty and eight studies used selective laser trabeculoplasty. There was considerable clinical and methodological diversity in these studies leading to statistical heterogeneity in results for the primary outcome "failure to control IOP" at 24 months. Risk ratios (RRs) ranged from 0.43 in favour of laser trabeculoplasty to 1.87 in favour of medication (5 studies, I = 89%). Studies of argon laser compared with medication were more likely to show a beneficial effect compared with studies of selective laser (test for interaction P = 0.0001) but the argon laser studies were older and the medication comparator group in those studies may have been less effective. We considered this to be low-certainty evidence because the trials were at risk of bias (they were not masked) and there was unexplained heterogeneity. There was evidence from two studies (624 eyes) that argon laser treatment was associated with less failure to stabilise visual field progression compared with medication (7% versus 11%, RR 0.70, 95% CI 0.42 to 1.16) at 24 months and one further large recent study of selective laser also reported a reduced risk of failure at 48 months (17% versus 26%) RR 0.65, 95% CI 0.52 to 0.81, 1178 eyes). We judged this outcome as moderate-certainty evidence, downgrading for risk of bias. There was only very low-certainty evidence on optic neuropathy progression. Adverse effects were more commonly seen in the laser trabeculoplasty group including peripheral anterior synechiae (PAS) associated with argon laser (32% versus 26%, RR 11.74, 95% CI 5.94 to 23.22; 624 eyes; 2 RCTs; low-certainty evidence); 5% of participants treated with laser in three studies of selective laser group had early IOP spikes (moderate-certainty evidence). One UK-based study provided moderate-certainty evidence that laser trabeculoplasty was more cost-effective. Laser trabeculoplasty versus trabeculectomy Three studies compared laser trabeculoplasty with trabeculectomy. All three studies enrolled participants with OAG (primary or secondary) and used argon laser. People receiving laser trabeculoplasty may have a higher risk of uncontrolled IOP at 24 months compared with people receiving trabeculectomy (16% versus 8%, RR 2.12, 95% CI 1.44 to 3.11; 901 eyes; 2 RCTs). We judged this to be low-certainty evidence because of risk of bias (trials were not masked) and there was inconsistency between the two trials (I = 68%). There was limited evidence on visual field progression suggesting a higher risk of failure with laser trabeculoplasty. There was no information on optic neuropathy progression, quality of life or costs. PAS formation and IOP spikes were not reported but in one study trabeculectomy was associated with an increased risk of cataract (RR 1.78, 95% CI 1.46 to 2.16) (very low-certainty evidence).
AUTHORS' CONCLUSIONS
Laser trabeculoplasty may work better than topical medication in slowing down the progression of open-angle glaucoma (rate of visual field loss) and may be similar to modern eye drops in controlling eye pressure at a lower cost. It is not associated with serious unwanted effects, particularly for the newer types of trabeculoplasty, such as selective laser trabeculoplasty.
Topics: Argon; Glaucoma; Glaucoma, Open-Angle; Humans; Ocular Hypertension; Optic Nerve Diseases; Trabeculectomy
PubMed: 35943114
DOI: 10.1002/14651858.CD003919.pub3 -
Physical Chemistry Chemical Physics :... Apr 2022The heating of a chromophore due to internal conversion and its cooling down due to energy dissipation to the solvent are crucial phenomena to characterize molecular...
The heating of a chromophore due to internal conversion and its cooling down due to energy dissipation to the solvent are crucial phenomena to characterize molecular photoprocesses. In this work, we simulated the nonadiabatic dynamics of cytosine, a prototypical chromophore undergoing ultrafast internal conversion, in three solvents-argon matrix, benzene, and water-spanning an extensive range of interactions. We implemented an analytical energy-transfer model to analyze these data and extract heating and cooling times. The model accounts for nonadiabatic effects, and excited- and ground-state energy transfer, and can analyze data from any dataset containing kinetic energy as a function of time. Cytosine heats up in the subpicosecond scale and cools down within 25, 4, and 1.3 ps in argon, benzene, and water, respectively. The time constants reveal that a significant fraction of the benzene and water heating occurs while cytosine is still electronically excited.
Topics: Argon; Benzene; Cytosine; Heating; Solvents; Water
PubMed: 35385568
DOI: 10.1039/d2cp00686c -
PloS One 2015Recently, the noble gas argon attracted significant attention due to its neuroprotective properties. However, the underlying molecular mechanism is still poorly...
PURPOSE
Recently, the noble gas argon attracted significant attention due to its neuroprotective properties. However, the underlying molecular mechanism is still poorly understood. There is growing evidence that the extracellular regulated kinase 1/2 (ERK1/2) is involved in Argon´s protective effect. We hypothesized that argon mediates its protective effects via the upstream located toll-like receptors (TLRs) 2 and 4.
METHODS
Apoptosis in a human neuroblastoma cell line (SH-SY5Y) was induced using rotenone. Argon treatment was performed after induction of apoptosis with different concentrations (25, 50 and 75 Vol% in oxygen 21 Vol%, carbon dioxide and nitrogen) for 2 or 4 hours respectively. Apoptosis was analyzed using flow cytometry (annexin-V (AV)/propidiumiodide (PI)) staining, caspase-3 activity and caspase cleavage. TLR density on the cells' surface was analyzed using FACS and immunohistochemistry. Inhibition of TLR signaling and extracellular regulated kinase 1/2 (ERK1/2) were assessed by western blot, activity assays and FACS analysis.
RESULTS
Argon 75 Vol% treatment abolished rotenone-induced apoptosis. This effect was attenuated dose- and time-dependently. Argon treatment was accompanied with a significant reduction of TLR2 and TLR4 receptor density and protein expression. Moreover, argon mediated increase in ERK1/2 phosphorylation was attenuated after inhibition of TLR signaling. ERK1/2 and TLR signaling inhibitors abolished the anti-apoptotic and cytoprotective effects of argon. Immunohistochemistry results strengthened these findings.
CONCLUSION
These findings suggest that argon-mediated anti-apoptotic and neuroprotective effects are mediated via inhibition of TLR2 and TLR4.
Topics: Apoptosis; Argon; Caspase 3; Cell Line, Tumor; Humans; MAP Kinase Signaling System; Neuroblastoma; Neuroprotection; Neuroprotective Agents; Phosphorylation; Rotenone; Signal Transduction; Toll-Like Receptor 2; Toll-Like Receptor 4
PubMed: 26624894
DOI: 10.1371/journal.pone.0143887 -
Nature May 2011Recent advances in catalysis have made the incorporation of fluorine into complex organic molecules easier than ever before, but selective, general and practical... (Review)
Review
Recent advances in catalysis have made the incorporation of fluorine into complex organic molecules easier than ever before, but selective, general and practical fluorination reactions remain sought after. Fluorination of molecules often imparts desirable properties, such as metabolic and thermal stability, and fluorinated molecules are therefore frequently used as pharmaceuticals or materials. But the formation of carbon-fluorine bonds in complex molecules is a significant challenge. Here we discuss reactions to make organofluorides that have emerged within the past few years and which exemplify how to overcome some of the intricate challenges associated with fluorination.
Topics: Argon; Carbon; Catalysis; Fluorine; Halogenation; Methylation
PubMed: 21614074
DOI: 10.1038/nature10108 -
Revista Espanola de Enfermedades... Nov 2019hemorrhagic radiation proctitis appears secondary to radiotherapy. Argon plasma is an effective, safe and easy-to-use technique with a relatively low cost. (Observational Study)
Observational Study
INTRODUCTION
hemorrhagic radiation proctitis appears secondary to radiotherapy. Argon plasma is an effective, safe and easy-to-use technique with a relatively low cost.
OBJECTIVES
to describe the short- and long-term response to argon plasma therapy in patients with hemorrhagic radiation proctitis.
METHOD
an observational prospective study was performed of a series of 82 patients with hemorrhagic radiation proctitis, attended at the National Center for Minimally Invasive Surgery between 2010 and 2016. Summary measurements and a comparison of means (paired Student's t-test) for the final and initial hemoglobin levels were used. In addition, the Kaplan-Meier method was used to determine the rectal bleeding recurrence free time.
RESULTS
in the present study, 54.9% of cases required 1-3 argon sessions and 86.6% required 1-5 sessions to resolve the bleeding, with a median of 3.0 sessions. In addition, 4.9% of patients had proctalgia as a complication. There was an improvement in hemoglobin of 2 g/dl. Rectal bleeding recurrence occurred in 8.5% of the patients during the nine months after therapy. Bleeding recurrence free time at three, six and nine months was 98.8%, 96.3% and 91.5%, respectively. Short-term therapy response was observed in all patients and long-term response after one year of follow-up was 91.5%.
CONCLUSION
argon plasma coagulation shows a good short- and long-term response with few therapy sessions and a low rate of complications in patients with chronic hemorrhagic radiation proctitis.
Topics: Aged; Argon; Female; Gastrointestinal Hemorrhage; Humans; Male; Middle Aged; Plasma Gases; Proctitis; Prospective Studies; Radiation Injuries; Radiotherapy; Time Factors; Treatment Outcome
PubMed: 31595754
DOI: 10.17235/reed.2019.5998/2018 -
Annals of Cardiac Anaesthesia 2019
Topics: Argon
PubMed: 30971590
DOI: 10.4103/aca.ACA_180_18