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1.
BMC Plant Biol ; 24(1): 59, 2024 Jan 22.
Article in English | MEDLINE | ID: mdl-38247007

ABSTRACT

Applying cold discharge plasma can potentially alter plants' germination characteristics by triggering their physiological activities. As a main crop in many countries, soybean was examined in the present study using cultivars such as Arian, Katoul, Saba, Sari, and Williams in a cold argon plasma. This study has been motivated by the importance of plant production worldwide, considering climate change and the increasing needs of human populations for food. This study was performed to inspect the effect of cold plasma treatment on seed germination and the impact of argon plasma on microbial decontamination was investigated on soybeans. Also, the employed cultivars have not been studied until now the radicals generated from argon were detected by optical emission spectrometry (OES), and a collisional radiative model was used to describe electron density. The germination properties, including final germination percentage (FGP), mean germination time (MGT), root length, and electrical conductivity of biomolecules released from the seeds, were investigated after the plasma treatments for 30, 60, 180, 300, and 420 s. The decontamination effect of the plasma on Aspergillus flavus (A.flavus) and Fusarium solani (F.solani) was also examined. The plasma for 60 s induced a maximum FGP change of 23.12 ± 0.34% and a lowest MGT value of 1.40 ± 0.007 days. Moreover, the ultimate root length was 56.12 ± 2.89%, in the seeds treated for 60 s. The plasma exposure, however, failed to yield a significant enhancement in electrical conductivity, even when the discharge duration was extended to 180 s or longer. Therefore, the plasma duration of 180 s was selected for the blotter technique. Both fungi showed successful sterilization; their infectivity inhibition was 67 ± 4 and 65 ± 3.1%, respectively. In general, the cold plasma used for soybeans in the present study preserved their healthy qualities and reduced the degree of fungal contamination.


Subject(s)
Glycine max , Plasma Gases , Humans , Argon , Decontamination , Germination , Plasma Gases/pharmacology
2.
J Appl Microbiol ; 135(9)2024 Sep 02.
Article in English | MEDLINE | ID: mdl-39264067

ABSTRACT

AIMS: This study aims to assess the potential bacterial inactivation pathway triggered by argon (Ar) cold atmospheric pressure plasma jet (CAPJ) discharge using spectroscopic and imaging techniques. METHODS AND RESULTS: Electrical and reactive species of the Ar CAPJ discharge was characterized. The chemical composition and morphology of bacteria pre- and post-CAPJ exposure were assessed using Fourier transform infrared (FTIR), Raman micro-spectroscopy, and transmission electron microscopy (TEM). A greater than 6 log reduction of Escherichia coli and Staphylococcus aureus was achieved within 60 and 120 s of CAPJ exposure, respectively. Extremely low D-values (<20 s) were recorded for both the isolates. The alterations in the FTIR spectra and Raman micro-spectra signals of post-CAPJ exposed bacteria revealed the degree of destruction at the molecular level, such as lipid peroxidation, protein oxidation, bond breakages, etc. Further, TEM images of exposed bacteria indicated the incurred damages on cell morphology by CAPJ reactive species. Also, the inactivation process varied for both isolates, as evidenced by the correlation between the inactivation curve and FTIR spectra. It was observed that the identified gas-phase reactive species, such as Ar I, O I, OH•, NO+, OH+, NO2-, NO3-, etc. played a significant role in bacterial inactivation. CONCLUSIONS: This study clearly demonstrated the effect of CAPJ exposure on bacterial cell morphology and molecular composition, illuminating potential bacterial inactivation mechanisms.


Subject(s)
Argon , Atmospheric Pressure , Escherichia coli , Plasma Gases , Staphylococcus aureus , Argon/pharmacology , Plasma Gases/pharmacology , Escherichia coli/drug effects , Spectroscopy, Fourier Transform Infrared , Staphylococcus aureus/drug effects , Staphylococcus aureus/physiology , Microscopy, Electron, Transmission , Spectrum Analysis, Raman , Microbial Viability
3.
Environ Res ; 252(Pt 3): 119015, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38692423

ABSTRACT

Carbon material modification and defect engineering are indispensable for bolstering the photocatalytic effectiveness of bismuth halide oxide (BiOX). In this study, a novel porous and defect-rich Ar-CB-2 photocatalyst was synthesized for emerging pollutants degradation. Leveraging the interfacial coupling effect of multi-walled carbon nanotubes (MWCNTs), we expanded the absorption spectrum of BiOI nanosheets and significantly suppressed the recombination of charge carriers. Introducing defects via Argon (Ar) plasma-etching further bolstered the adsorption efficacy and electron transfer properties of photocatalyst. In comparison to the pristine BiOI and CB-2, the Ar-CB-2 photocatalyst demonstrated superior photodegradation efficiency, with the first-order reaction rates for the photodegradation of tetracycline (TC) and bisphenol A (BPA) increasing by 2.83 and 4.53 times, respectively. Further probe experiments revealed that the steady-state concentrations of ·O2- and 1O2 in the Ar-CB-2/light system were enhanced by a factor of 1.67 and 1.28 compared to CB-2/light system. This result confirmed that the porous and defect-rich structure of Ar-CB-2 inhibited electron-hole recombination and boosted photocatalyst-oxygen interaction, swiftly transforming O2 into active oxygen species, thus accelerating their production. Furthermore, the possible degradation pathways for TC and BPA in the Ar-CB-2/light system were predicted. Overall, these findings offered a groundbreaking approach to the development of highly effective photocatalysts, capable of swiftly breaking down emerging pollutants.


Subject(s)
Argon , Benzhydryl Compounds , Bismuth , Nanotubes, Carbon , Phenols , Photolysis , Bismuth/chemistry , Nanotubes, Carbon/chemistry , Catalysis , Porosity , Phenols/chemistry , Benzhydryl Compounds/chemistry , Argon/chemistry , Tetracycline/chemistry , Water Pollutants, Chemical/chemistry , Environmental Pollutants/chemistry , Photochemical Processes , Plasma Gases/chemistry
4.
Cryobiology ; 116: 104949, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39117031

ABSTRACT

Subcooled liquid nitrogen and nitrogen slush are often considered for high-speed cooling, but their preparation and maintenance are not easy. To address this issue, a unique device was designed to prepare subcooled liquid argon (SLA) using liquid nitrogen (LN). The cooling process was mathematically modeled to predict the preparation time. If the interlayer space between LN and liquid argon is filled with nitrogen gas, liquid argon could be cooled to 3.5 K subcooling within 1 h. If the interlayer is filled with air, 2 h are required to achieve the same subcooled state. An additional 1000 mL of LN was required for the preparation of 600 mL of 3.5 K SLA. The cooling tests of 3 µL microdroplets in 3 mm-6 mm capillary quartz tubes were duplicated to evaluate the potential of SLA. It was found that the cooling rate of microdroplet in the 3.5 K subcooled SLA is very close to that in the 3 K subcooled LN, higher than that in the saturated LN. The convenience of preparation and maintenance of SLA can make it good choice of cryogen for cryopreservation of biomaterials.


Subject(s)
Argon , Cold Temperature , Nitrogen , Argon/chemistry , Nitrogen/chemistry , Cryopreservation/methods , Cryoprotective Agents/chemistry , Cryoprotective Agents/pharmacology
5.
Int J Mol Sci ; 25(5)2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38474129

ABSTRACT

Li3V2(PO4)3 cathodes for Li-ion batteries (LIBs) were synthesized using a hydrothermal method with the subsequent annealing in an argon atmosphere to achieve optimal properties. The X-ray diffraction analysis confirmed the material's single-phase nature, while the scanning electron microscopy revealed a granular structure, indicating a uniform particle size distribution, beneficial for electrochemical performance. Magnetometry and electron spin resonance studies were conducted to investigate the magnetic properties, confirming the presence of the relatively low concentration and highly uniform distribution of tetravalent vanadium ions (V4+), which indicated low lithium deficiency values in the original structure and a high degree of magnetic homogeneity in the sample, an essential factor for consistent electrochemical behavior. For this pure phase Li3V2(PO4)3 sample, devoid of any impurities such as carbon or salts, extensive electrochemical property testing was performed. These tests resulted in the experimental discovery of a remarkably high lithium diffusion coefficient D = 1.07 × 10-10 cm2/s, indicating excellent ionic conductivity, and demonstrated impressive stability of the material with sustained performance over 1000 charge-discharge cycles. Additionally, relithiated Li3V2(PO4)3 (after multiple electrochemical cycling) samples were investigated using scanning electron microscopy, magnetometry and electron spin resonance methods to determine the extent of degradation. The combination of high lithium diffusion coefficients, a low degradation rate and remarkable cycling stability positions this Li3V2(PO4)3 material as a promising candidate for advanced energy storage applications.


Subject(s)
Lithium , Argon , Electric Conductivity , Electrodes , Ions
6.
Lab Invest ; 103(11): 100256, 2023 11.
Article in English | MEDLINE | ID: mdl-37797886

ABSTRACT

We examined the effects of gene ablation and chemical inhibition of transient receptor potential ankyrin 1 (TRPA1) on the growth of experimental argon laser-induced choroidal neovascularization (CNV) in mice. CNV was induced in the eyes of 6- to 8-week-old TRPA1-null (knockout [KO]) and wild-type (WT) mice by argon laser irradiation. Gene expression analysis was performed in laser-injured tissues at days 1 and 3. CNV growth was evaluated at day 14. Reciprocal bone marrow transplantation was performed between each genotype to identify the components responsible for either recipient tissue or bone marrow-derived inflammatory cells. Our results show that laser irradiation successfully induced CNV growth at the site of laser injury. The size of induced CNV was significantly smaller in KO mice than in WT mice at day 14, as determined by angiography with fluorescein isothiocyanate-dextran. Invasion of neutrophils, but not macrophages, was suppressed in association with suppression of the expression of transforming growth factor ß1 and interleukin 6 in laser-irradiated KO tissue. Bone marrow transplantation indicated that the genotype of the recipient mouse, but not of inflammatory cells, is attributable to the KO phenotype. Systemic administration of a TRPA1 antagonist also reduced the CNV in a WT mouse. In conclusion, TRPA1 signaling in local cells is involved in growth of laser-induced CNV. The phenotype was not attributable to vascular endothelial cells and inflammatory cells. Blocking TRPA1 signal may therefore be a potential treatment strategy for CNV-related ocular diseases.


Subject(s)
Choroidal Neovascularization , Transforming Growth Factor beta1 , Animals , Mice , Argon , Choroidal Neovascularization/genetics , Choroidal Neovascularization/metabolism , Cytoskeletal Proteins , Disease Models, Animal , Endothelial Cells/metabolism , Lasers , Mice, Inbred C57BL , Mice, Knockout , Neutrophil Infiltration , Transforming Growth Factor beta1/genetics
7.
Phys Rev Lett ; 130(22): 221802, 2023 Jun 02.
Article in English | MEDLINE | ID: mdl-37327426

ABSTRACT

We present the results of a search for heavy QCD axions performed by the ArgoNeuT experiment at Fermilab. We search for heavy axions produced in the NuMI neutrino beam target and absorber decaying into dimuon pairs, which can be identified using the unique capabilities of ArgoNeuT and the MINOS near detector. This decay channel is motivated by a broad class of heavy QCD axion models that address the strong CP and axion quality problems with axion masses above the dimuon threshold. We obtain new constraints at a 95% confidence level for heavy axions in the previously unexplored mass range of 0.2-0.9 GeV, for axion decay constants around tens of TeV.


Subject(s)
Pentaerythritol Tetranitrate , Argon
8.
Inorg Chem ; 62(29): 11304-11317, 2023 Jul 24.
Article in English | MEDLINE | ID: mdl-37439562

ABSTRACT

The mechanism of the metal centered reduction of metmyoglobin (MbFeIII) by sulfide species (H2S/HS-) under an argon atmosphere has been studied by a combination of spectroscopic, kinetic, and computational methods. Asymmetric S-shaped time-traces for the formation of MbFeII at varying ratios of excess sulfide were observed at pH 5.3 < pH < 8.0 and 25 °C, suggesting an autocatalytic reaction mechanism. An increased rate at more alkaline pHs points to HS- as relevant reactive species for the reduction. The formation of the sulfanyl radical (HS•) in the slow initial phase was assessed using the spin-trap phenyl N-tert-butyl nitrone. This radical initiates the formation of S-S reactive species as disulfanuidyl/ disulfanudi-idyl radical anions and disulfide (HSSH•-/HSS•2- and HSS-, respectively). The autocatalysis has been ascribed to HSS-, formed after HSSH•-/HSS•2- disproportionation, which behaves as a fast reductant toward the intermediate complex MbFeIII(HS-). We propose a reaction mechanism for the sulfide-mediated reduction of metmyoglobin where only ferric heme iron initiates the oxidation of sulfide species. Beside the chemical interest, this insight into the MbFeIII/sulfide reaction under an argon atmosphere is relevant for the interpretation of biochemical aspects of ectopic myoglobins found on hypoxic tissues toward reactive sulfur species.


Subject(s)
Hydrogen Sulfide , Metmyoglobin , Metmyoglobin/chemistry , Anaerobiosis , Argon , Myoglobin/chemistry , Oxidation-Reduction , Sulfides , Kinetics
9.
J Chem Phys ; 159(1)2023 Jul 07.
Article in English | MEDLINE | ID: mdl-37417756

ABSTRACT

Using a combination of tight binding molecular dynamics and ab initio molecular dynamics simulations, we study the mechanisms of bombardment-induced decomposition of hydrofluorocarbons (HFCs) physisorbed on silicon nitride for ion energies of ≤35 eV. We propose three key mechanisms by which bombardment-driven HFC decomposition can occur, focusing on the two pathways observed at these low ion energies: "direct decomposition" and "collision assisted surface reactions (CASRs)." Our simulation results clearly demonstrate the importance of the presence of favorable reaction coordinates for enabling CASR, which dominates at lower energies (≈11 eV). At higher energies, direct decomposition becomes more favored. Our work also predicts that the primary decomposition pathways for CH3F and CF4 are CH3F → CH3 + F and CF4 → CF2 + 2F, respectively. The fundamental details of these decomposition pathways and the decomposition products formed under ion bombardment have implications for plasma-enhanced atomic layer etching process design that will be discussed.


Subject(s)
Molecular Dynamics Simulation , Silicon Compounds , Argon
10.
J Chem Phys ; 158(2): 024305, 2023 Jan 14.
Article in English | MEDLINE | ID: mdl-36641418

ABSTRACT

Bands of the g 6Φ-X 4Δ, g 6Φ-A 4Π, g 6Φ-a 6Δ, and g 6Φ-b 6Π electronic transitions of iron monodeuteride (FeD) have been measured in laser excitation and in dispersed fluorescence. The molecules were produced both in a cold supersonic molecular jet source and in a chemical reaction between iron pentacarbonyl [Fe(CO5)] and a microwave discharge of argon and hydrogen gases. Dispersed fluorescence from the latter source was detected at high resolution with a Fourier transform spectrometer, yielding a large number of the transitions observed. The data reveal that FeD experiences strong interstate couplings that compromise fitting of the data with traditional Hamiltonians but that the problem is less severe than in corresponding spectra of FeH. This work greatly expands the available data on FeD, which were previously characterized only through the F 4Δ-X 4Δ spectrum and pure rotational data in the ground state.


Subject(s)
Electronics , Gases , Argon , Hydrogen , Spectrum Analysis
11.
Proc Natl Acad Sci U S A ; 117(29): 17063-17067, 2020 07 21.
Article in English | MEDLINE | ID: mdl-32631997

ABSTRACT

Little is known about the exchange of gaseous nitrogen (N2) with the atmosphere in freshwater systems. Although the exchange of N2, driven by excess or deficiencies relative to saturation values, has little relevance to the atmospheric N2 pool due to its large size, it does play an important role in freshwater and marine nitrogen (N) cycling. N-fixation converts N2 to ammonia, which can be used by microbes and phytoplankton, while denitrification/anammox effectively removes it by converting oxidized, inorganic N to N2 We examined N2 saturation to infer net biological nitrogen processes in 34 lakes across 5° latitude varying in trophic status, mixing regime, and bathymetry. Here, we report that nearly all lakes examined in the upper Midwest (USA) were supersaturated with N2 (>85% of samples, n = 248), suggesting lakes are continuously releasing nitrogen to the atmosphere. The traditional paradigm is that freshwaters compensate for N-limitation through N-fixation, but these results indicate that lakes were constantly losing N to the atmosphere via denitrification and/or anammox, suggesting that terrestrial N inputs are needed to balance the internal N cycle.


Subject(s)
Lakes , Nitrogen/analysis , Argon/analysis , Greenhouse Gases/analysis , Lakes/analysis , Lakes/chemistry , Minnesota , Nitrogen Fixation , Oxygen/analysis
12.
Pediatr Surg Int ; 40(1): 21, 2023 Dec 18.
Article in English | MEDLINE | ID: mdl-38108911

ABSTRACT

PURPOSE: Neonatal sepsis is a systemic inflammatory infection common in premature infants and a leading cause of mortality. Argon is an emerging interest in the field of noble gas therapy. Neonates with severe sepsis are frequently mechanically ventilated creating an opportunity for inhalation therapy. We aimed to investigate argon inhalation as a novel experimental therapy in neonatal sepsis. METHODS: Sepsis was established in C57BL/6 neonatal mice by a lipopolysaccharide intraperitoneal injection on postnatal day 9. Septic pup mice were exposed to room air as well as non-septic controls. In the argon group, septic pup mice were exposed to argon (70% Ar, 30% O2) for 6 h in a temperature-controlled environment. RESULTS: At 6 h, survival was significantly enhanced when septic mice received argon compared to septic controls. Serum profiles of cytokine release were significantly attenuated as well as lung architecture restored. CONCLUSIONS: Our findings suggest that argon inhalation as a novel treatment for neonatal sepsis, reducing mortality and counteracting the acute systemic inflammatory response in the blood and preserving the architecture of the lung. This research can contribute to a paradigm shift in the treatment and outcome of neonates with sepsis.


Subject(s)
Neonatal Sepsis , Sepsis , Humans , Infant , Animals , Mice , Mice, Inbred C57BL , Argon/therapeutic use , Sepsis/therapy , Inflammation
13.
Int J Mol Sci ; 24(24)2023 Dec 14.
Article in English | MEDLINE | ID: mdl-38139311

ABSTRACT

This work systematically examines the interactions between a single argon atom and the edges and faces of cyclic H2O clusters containing three-five water molecules (Ar(H2O)n=3-5). Full geometry optimizations and subsequent harmonic vibrational frequency computations were performed using MP2 with a triple-ζ correlation consistent basis set augmented with diffuse functions on the heavy atoms (cc-pVTZ for H and aug-cc-pVTZ for O and Ar; denoted as haTZ). Optimized structures and harmonic vibrational frequencies were also obtained with the two-body-many-body (2b:Mb) and three-body-many-body (3b:Mb) techniques; here, high-level CCSD(T) computations capture up through the two-body or three-body contributions from the many-body expansion, respectively, while less demanding MP2 computations recover all higher-order contributions. Five unique stationary points have been identified in which Ar binds to the cyclic water trimer, along with four for (H2O)4 and three for (H2O)5. To the best of our knowledge, eleven of these twelve structures have been characterized here for the first time. Ar consistently binds more strongly to the faces than the edges of the cyclic (H2O)n clusters, by as much as a factor of two. The 3b:Mb electronic energies computed with the haTZ basis set indicate that Ar binds to the faces of the water clusters by at least 3 kJ mol-1 and by nearly 6 kJ mol-1 for one Ar(H2O)5 complex. An analysis of the interaction energies for the different binding motifs based on symmetry-adapted perturbation theory (SAPT) indicates that dispersion interactions are primarily responsible for the observed trends. The binding of a single Ar atom to a face of these cyclic water clusters can induce perturbations to the harmonic vibrational frequencies on the order of 5 cm-1 for some hydrogen-bonded OH stretching frequencies.


Subject(s)
Quantum Theory , Water , Argon/chemistry , Water/chemistry , Thermodynamics , Hydrogen Bonding
14.
Int J Mol Sci ; 24(2)2023 Jan 12.
Article in English | MEDLINE | ID: mdl-36675062

ABSTRACT

Conformational changes of 5-chloro-3-nitro-2-hydroxyacetophenone were studied by experimental and theoretical methods. Phototransformations of the compound were induced in low-temperature argon matrices by using UV radiation, which was followed by FT-IR measurements. Two types of changes within the molecule were detected: rotations of the hydroxyl and acetyl groups. A new conformer without an intramolecular hydrogen bond was generated upon irradiation with λ = 330 nm, whereas the reverse reaction was observed at 415 nm.


Subject(s)
Cold Temperature , Ultraviolet Rays , Spectroscopy, Fourier Transform Infrared/methods , Argon/chemistry , Lasers
15.
Int J Mol Sci ; 24(3)2023 Jan 22.
Article in English | MEDLINE | ID: mdl-36768501

ABSTRACT

This research focuses on studying the effects of various pretreatment types on a PtCu/C catalyst synthesized by the co-deposition of metal precursors. The treatment in a 1 M HNO3 solution for 1 h is shown to result in a slight increase in activity in the oxygen electroreduction reaction (both the mass activity and specific activity calculated for the value of the electrochemically active surface area). The sample obtained after the thermal treatment, which is carried out at 350 °C under an argon atmosphere for 1 h, demonstrates 1.7 times higher specific activity than the sample before the treatment. The durability testing results obtained by the stress testing method in a potential range of 0.6-1.4 V during 2000 cycles show that the PtCu/C catalysts after both the acid treatment and the thermal treatment are characterized by higher residual activity than the sample in the "as-prepared" state.


Subject(s)
Atmosphere , Exercise Test , Argon , Oxygen
16.
Int J Mol Sci ; 25(1)2023 Dec 21.
Article in English | MEDLINE | ID: mdl-38203320

ABSTRACT

In this study, we applied argon plasma treatment to titanium surfaces with nanostructures deposited by concentrated alkali treatment and investigated the effects on the surface of the material and the tissue surrounding an implant site. The results showed that the treatment with argon plasma removed carbon contaminants and increased the surface energy of the material while the nanoscale network structure deposited on the titanium surface remained in place. Reactive oxygen species reduced the oxidative stress of bone marrow cells on the treated titanium surface, creating a favorable environment for cell proliferation. Good results were observed in vitro evaluations using rat bone marrow cells. The group treated with argon plasma exhibited the highest apatite formation in experiments using simulated body fluids. The results of in vivo evaluation using rat femurs revealed that the treatment improved the amount of new bone formation around an implant. Thus, the results demonstrate that argon plasma treatment enhances the ability of nanostructured titanium surfaces to induce hard tissue differentiation and supports new bone formation around an implant site.


Subject(s)
Nanostructures , Plasma Gases , Animals , Rats , Argon/pharmacology , Titanium/pharmacology , Plasma Gases/pharmacology , Plasma
17.
Int J Mol Sci ; 24(24)2023 Dec 09.
Article in English | MEDLINE | ID: mdl-38139120

ABSTRACT

Nanometals constitute a rapidly growing area of research within nanotechnology. Nanosilver and nanogold exhibit significant antimicrobial, antifungal, antiviral, anti-inflammatory, anti-angiogenic, and anticancer properties. The size and shape of nanoparticles are critical for determining their antimicrobial activity. In this study, silver and gold nanoparticles were synthesized within a hyaluronic acid matrix utilizing distilled water and distilled water treated with low-pressure, low-temperature glow plasma in an environment of air and argon. Electron microscopy, UV-Vis and FTIR spectra, water, and mechanical measurements were conducted to investigate the properties of nanometallic composites. This study also examined their microbiological properties. This study demonstrated that the properties of the composites differed depending on the preparation conditions, encompassing physicochemical and microbiological properties. The application of plasma-treated water under both air and argon had a significant effect on the size and distribution of nanometals. Silver nanoparticles were obtained between the range of 5 to 25 nm, while gold nanoparticles varied between 10 to 35 nm. The results indicate that the conditions under which silver and gold nanoparticles are produced have a significant effect on their mechanical and antibacterial properties.


Subject(s)
Metal Nanoparticles , Silver , Silver/chemistry , Gold/chemistry , Hyaluronic Acid/chemistry , Metal Nanoparticles/chemistry , Argon , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Water
18.
Molecules ; 28(1)2023 Jan 03.
Article in English | MEDLINE | ID: mdl-36615600

ABSTRACT

Chlorella vulgaris is a green microalga with a high chlorophyll content, representing a valuable source of green pigments for food applications. As the application of whole biomass can promote an unpleasant fish-like flavor, the use of chlorophyll extract can overcome this drawback. However, chlorophylls tend to easily degrade when out of the chloroplasts, decreasing their potential as a food ingredient. Thus, to study the suitable conditions for isolated chlorophylls preservation, in this work, the influence of temperature (4 to 60 °C), light (dark or 24 h photoperiod), alkaline conditions (with or without aqueous NaOH addition), and modified atmosphere (air or argon atmosphere) on the stability of the color in ethanolic solutions obtained from C. vulgaris were studied. The loss of green color with temperature followed the first-order kinetics, with an activation energy of 74 kJ/mol. Below 28 °C and dark conditions were suitable to preserve isolated chlorophylls. The addition of NaOH and an inert argon-rich atmosphere did not exhibit a statistically positive effect on color preservation. In the case study, cooked cold rice was colored to be used in sushi. The color remained stable for up to 3 days at 4 °C. Therefore, this work showed that C. vulgaris chlorophylls could be preserved in ethanolic solutions at room or lower temperatures when protected from light, allowing them to obtain a suitable natural food ingredient to color foodstuffs.


Subject(s)
Chlorella vulgaris , Food Ingredients , Chlorella vulgaris/metabolism , Argon , Sodium Hydroxide , Chlorophyll/metabolism
19.
Rev Esp Enferm Dig ; 115(9): 480-487, 2023 09.
Article in English | MEDLINE | ID: mdl-36645061

ABSTRACT

BACKGROUND: argon plasma coagulation (APC) is the current endoscopic treatment of choice for patients who develop chronic radiation proctopathy. The aim of this study was to identify risk factors associated with treatment failure. METHODS: one hundred and ninety-nine patients treated with argon plasma coagulation in a single center were retrospectively analyzed. RESULTS: twenty-four (12.06 %) patients were classified as APC treatment failures. Requirement of red blood cells transfusion and/or hemoglobin < 7 g/dl (OR 12.19, 95 % CI: 2.78-53.45, p < 0.001) and severe bleeding frequency (OR 2.76, 95 % CI: 1.13-6.72, p = 0.03) at diagnosis and prior to endoscopic therapy were associated with argon plasma coagulation treatment failure. Nineteen patients of the successful therapy group developed bleeding recurrence; no risk factors were associated with a shorter recurrence-free time. More than four APC sessions were associated to a higher risk of surgical intervention for bleeding control (OR 87.00, 95 % CI: 10.23-740.18, p < 0.001). CONCLUSION: requirement of red blood cells transfusion and/or hemoglobin < 7 g/dl and a severe bleeding frequency (more than five days per week) were identified as the most important risk factors for treatment failure in patients with chronic radiation proctopathy.


Subject(s)
Argon Plasma Coagulation , Proctitis , Humans , Argon Plasma Coagulation/adverse effects , Proctitis/etiology , Treatment Outcome , Gastrointestinal Hemorrhage/etiology , Gastrointestinal Hemorrhage/surgery , Retrospective Studies , Argon , Treatment Failure , Hemoglobins/analysis
20.
BMC Oral Health ; 23(1): 27, 2023 01 17.
Article in English | MEDLINE | ID: mdl-36650477

ABSTRACT

PURPOSE: Biofilm-free implant surface is ultimate prerequisite for successful soft and bone tissue integration. Objective of the study was to estimate the effects of argon plasma healing abutment pre-treatment (PT) on peri-implant soft-tissue phenotype (PiSP), inflammation, plaque accumulation and the microbiome (PiM) between non-treated (NPT) and treated (PT) abutments following 3-months healing period. The hypothesis was that cell-conductive and antimicrobial properties of PT would yield optimal conditions for soft tissue integration. MATERIAL AND METHODS: Two months following second-phase surgery, microbiological and clinical parameters were assessed around thirty-six healing abutments with two types of microtopography, smooth surface (MACHINED) and ultrathin threaded microsurface (ROUGH). A two level randomization schema was used to achieve equal distribution and abutments were randomly divided into rough and machined groups, and then divided into PT and NPT groups. PiM was assessed using next-generation DNA sequencing. RESULTS: PiM bacterial composition was highly diverse already two months post-implantation, consisting of key-stone pathogens, early and late colonizers, while the mycobiome was less diverse. PT was associated with lower plaque accumulation and inflammation without significant impact on PiSP, while in NPT clinical parameters were increased and associated with periopathogens. NPT mostly harbored late colonizers, while PT exerted higher abundance of early colonizers suggesting less advanced plaque formation. Interaction analysis in PT demonstrated S. mitis co-occurrence with pro-healthy Rothia dentocariosa and co-exclusion with Parvimonas micra, Porphyromonas endodontalis and Prevotella oris. PiSP parameters were generally similar between the groups, but significant association between PiM and keratinized mucosa width was observed in both groups, with remarkably more expressed diversity in NPT compared to PT. PT resulted in significantly lower BOP and PI around rough and machined abutments, respectively, without specific effect on PiM and PiSP. CONCLUSIONS: PT contributed to significantly the less advanced biofilm accumulation and inflammation without specific effects on PiSP.


Subject(s)
Dental Implants , Dental Plaque , Microbiota , Plasma Gases , Humans , Argon , Dental Implantation, Endosseous , Dental Prosthesis Design , Inflammation , Titanium
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