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1.
J Environ Health Sci Eng ; 22(1): 197-208, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38887774

RESUMO

Spent caustic is a used industrial caustic whose chemical content puts it in the special waste category. The disposal of this waste and the production of value-added products from it has attracted the attention of researchers not only to solve environmental problems but also to take advantage of its byproducts. This research has experimentally proved the transferred thermal plasma technology as a practical method feasible for the disposal of spent caustic. In this study, the applied voltage, electrical current, and feed rate are variable parameters, and others are kept constant. GC analysis showed H2 as the main product, which is environmentally beneficial. The percentage of hydrogen production of approximately 74% is a promising result, considering the difficulty of achieving such a high percentage of hydrogen.

2.
Langmuir ; 40(23): 12148-12158, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38806445

RESUMO

During the past decade, ever-increasing electromagnetic pollution has excited a global concern. A sustainable resource, facile experimental scenario, fascinating reflection loss (RL), and broad efficient bandwidth are the substantial factors that intrigue researchers. This research led to the achievement of a brilliant microwave-absorbing material by treating pampas as biomass. The carbon-based microfibers attained by biowaste were treated by plasma under diverse environments to amplify their microwave-absorbing features. Moreover, a pyrolysis scenario was performed to compare the results. The reductive processes were performed by H2 plasma and carbonization. However, the CO2 plasma was performed to regulate the heteroatoms and defects. Interestingly, polystyrene (PS) was applied as a microwave-absorbing matrix. The aromatic rings existing in the absorbing medium establish electrostatic interactions, elevating interfacial polarization, and physical characteristics of PS augment the practical applications of the final product. The manipulated biomasses were characterized by Raman, X-ray diffraction, energy-dispersive spectroscopy, field emission scanning electron microscopy, and diffuse reflection spectroscopy analyses. Eventually, the microwave-absorbing features were estimated by a vector network analyzer. The plasma-treated pampas under H2/Ar blended with PS gained a maximum RL of -90.65 dB at 8.79 GHz and an efficient bandwidth (RL ≤ -10 dB) of 4.24 GHz with a thickness of 3.20 mm; meanwhile, plasma treatment under CO2 led to a maximum RL of 97.99 dB at 14.92 GHz and an efficient bandwidth of 7.74 GHz with a 2.05 mm thickness. Particularly, the biomass plasmolyzed under Ar covered the entire X and Ku bands with a thickness of 2.10 mm. Notably, total shielding efficiencies of the treated bioinspired materials were up to ≈99%, desirable for practical applications.

3.
PLoS One ; 19(5): e0303795, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38771745

RESUMO

Recombinant proteins are essential in various industries, and scientists employ genetic engineering and synthetic biology to enhance the host cell's protein production capacity. Stress response pathways have been found effective in augmenting protein secretion. Cold atmospheric pressure plasma (CAP) can induce oxidative stress and enhance protein production. Previous studies have confirmed the applicability of CAP jets on Phytase and green fluorescent protein (GFP) production in Pichia pastoris hosts. This study investigates the effect of CAP treatment on another valuable recombinant protein, Endoglucanase II (EgII), integrated into the Pichia pastoris genome. The results demonstrated that plasma induction via two different ignition modes: sinusoidal alternating current (AC) and pulsed direct current (DC) for 120, 180, and 240 s has boosted protein secretion without affecting cell growth and viability. The AC-driven jet exhibited a higher percentage increase in secretion, up to 45%. Simulation of plasma function using COMSOL software provided a pattern of electron temperature (Te) and density distribution, which determine the plasma cocktail's chemistry and reactive species production. Furthermore, electron density (ne) and temperature were estimated from the recorded optical spectrum. The difference in electron properties may explain the moderately different impressions on expression capability. However, cell engineering to improve secretion often remains a trial-and-error approach, and improvements are, at least partially, specific to the protein produced.


Assuntos
Celulase , Gases em Plasma , Proteínas Recombinantes , Gases em Plasma/farmacologia , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , Celulase/metabolismo , Celulase/genética , Pressão Atmosférica , Simulação por Computador , Saccharomycetales/genética , Saccharomycetales/metabolismo
4.
Heliyon ; 10(8): e29068, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38660250

RESUMO

Hydrogen sulfide (H2S) is known as a harmful pollutant for the environment and human health, and its emission control is a high priority. Non-thermal plasma is an effective technology in this field. In this study, for the first time, the performance of direct and indirect H2S plasma conversion methods was compared, optimized, and modeled with the CCD method. H2S was diluted in zero air, and the study investigated the effect of discharge power, relative humidity, total flow rate, initial H2S concentration, and their interactions. ANOVA results showed that the models for H2S conversion efficiency and energy yield were significant and efficient. The direct method achieved a maximum conversion efficiency of 56 % and energy yield of 3.43 g/kWh, while the indirect method produced 68 % conversion efficiency and 1.59 g/kWh energy yield. According to the process optimization results, the direct conversion method is more optimal than the indirect conversion method due to the presence of active species and high-energy electrons in the plasma treatment, and it is a better choice if there are suitable working conditions.

5.
Phys Chem Chem Phys ; 26(14): 11056-11063, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38529535

RESUMO

In this work, employing first-principles calculations, we systematically investigate the atomic structure and electronic and optical properties of the AgTe monolayer, as well as the impact of alkali metal (Li, Na, K) and alkaline earth metal (Be, Mg, Ca) atoms decoration. The AgTe monolayer exhibits metallic characteristics. When Li, Na, K, and Mg atoms are decorated on the AgTe monolayer, the decorated AgTe monolayers are dynamically stable. In contrast, with Be and Ca atoms, the decorated structures are found to be dynamically unstable. Interestingly, the decoration of Li, Na, and K atoms into the AgTe monolayer can open the band gaps in the decorated Li-, Na- and K-AgTe monolayers around the Fermi level, leading to the actualization of metal-to-semiconductor transitions. In contrast, the decorated Mg-AgTe monolayer maintains its metallic characteristic. The highest electron and hole mobilities are achieved in the Na-AgTe monolayer among the decorated structures, suggesting the applicability of this structure in photovoltaic applications. The optical study shows that Li-, Na- and K-decorated AgTe monolayers have improved light absorption in the visible light region. Consequently, our findings shed light on the decoration of these 2D material monolayers and can potentially enhance and motivate studies in producing these monolayers for current nanodevices and future applications.

6.
Heliyon ; 10(4): e26280, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38384532

RESUMO

Metal-organic frameworks (MOFs) as carbon dioxide adsorption in combination with metal oxides have shown catalyst application in CO2 conversion. Herein, the MgO/HKUST-1 catalyst is synthesized to direct conversion of CO2 upon dilution by argon in a cylindrical dielectric barrier discharge (DBD) reactor. A water-cooling circulation adjusts the reactor temperature, and aluminum powder is used as a high-voltage electrode. The effect of the discharge power, feed flow rate, CO2 fraction, and their interaction in plasma and plasma catalyst method on CO2 conversion (R1), effective CO2 conversion (R2), and energy efficiency (R3) is evaluated by central composite design (CCD) based on response surface methodology. The Analysis of Variance (ANOVA) results demonstrate that the quadratic regression model describes CO2 conversion and effective CO2 conversion, and the reduced cubic model describes energy efficiency. The results indicate that the method (plasma, plasma catalyst) and discharge power on R1 and R2 have a considerable effect. Also, the method and CO2 fraction on R3 have the greatest impact, respectively. In the plasma and plasma catalyst method maximum CO2 conversion is 12.3% and 20.5% at a feed flow rate of 80 ml/min, CO2 fraction of 50%, and discharge power of 74 W.

7.
Heliyon ; 10(1): e23386, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38187351

RESUMO

This study used the FEDBD plasma device for skin rejuvenation in animal samples. There were two groups of six male Wistar rats. Before starting the treatment, immediately after the treatment, the fourth week, and the tenth week of follow-up, biometric tests were performed, including moisture level, evaporation from the skin surface, erythema and melanin, skin elasticity and firmness with an MPA9 device and cutometer. The thickness and density of the epidermis and dermis, an essential indicator in rejuvenation, were evaluated with a skin ultrasound device. Also, the level of oxygen, perfusion, and interstitial water (edema) was checked using a Tivita tissue hyperspectral camera at a depth of 6 mm of the skin.

8.
Sci Rep ; 13(1): 17536, 2023 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-37845238

RESUMO

A multiferroic nanostructure of manganese ferrite barium-titanate called magneto-electric nanoparticles (MENs) was synthesized by a co-precipitation method. FTIR, Raman spectroscopy, TEM, and X-ray diffraction confirmed the presence of spinel core and perovskite shell phases with average crystallite sizes of 70-90 nm. Magnetic, optical, and magnetoelectrical properties of MENs were investigated using VSM, UV-Vis spectrophotometry, DLS, and EIS spectroscopy techniques. After pre-activation by low-pressure argon (Ar) plasma, the MENs were functionalized by a highly hydrophilic acrylic acid and Oxygen (AAc+O2) mixture to produce COOH and C=O-rich surfaces. The loading and release of doxorubicin hydrochloride (DOX) on MENs were investigated using UV-vis and fluorescence spectrophotometry under alternating low-frequency magnetic fields. Plasma treatment enabled drug-loading control by changing the particles' roughness as physical adsorption and creating functional groups for chemical absorption. This led to reduced metabolic activity and cell adherences associated with elevated expression of pro-apoptotic genes (BCL-2, caspase 3) in 4T1 breast cancer cells in vitro exposed to alternating current magnetic field (ACMF) compared to MENs-DOX without field exposure. ACMF-potentiated anticancer effects of MENs were validated in vivo in tumor-bearing Balb/C mice. Altogether, our results suggest potentiated drug loading of MENs showing superior anticancer activity in vitro and in vivo when combined with ACMF.


Assuntos
Doxorrubicina , Nanopartículas , Animais , Camundongos , Doxorrubicina/farmacologia , Campos Magnéticos , Nanopartículas/química , Fenômenos Químicos , Magnetismo
9.
J Environ Health Sci Eng ; 21(2): 475-484, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37869603

RESUMO

Formaldehyde, a volatile organic compound (VOC), is one of the main gaseous pollutants from commercial cooking. The present study evaluated the effectiveness of a laboratory-scale ozone-assisted indirect plasma method for formaldehyde removal using response surface methodology (RSM). A dielectric barrier discharge (DBD) reactor was used for ozone generation. Inlet HCHO concentration, ozone concentration, and residence time were considered the design parameters, and formaldehyde removal efficiency (response 1) and energy yield (response 2) were considered response parameters. The optimized models showed a positive correlation between the predicted and experimental outcomes. Inlet ozone concentration, the most significant parameter in the removal efficiency model, represented a positive correlation with this response in most parts of the operating region. The optimal point with the highest desirability (i.e., D1 point) was obtained at the inlet HCHO concentration of 120 ppm, inlet ozone concentration of 40 ppm, and reaction time of 11.35 s within the parameter ranges studied, resulting in 64% removal efficiency and 2.64 g/kWh energy yield. At the point with the second highest desirability (D2), 100% removal efficiency along with 0.7 g/kWh energy yield was achieved indicating the very good performance of the process. The indirect plasma approach used in this study presented a successful performance in terms of removal efficiency along with acceptable energy yield compared to other plasma-assisted processes reported in the literature. The results suggested that ozone-assisted indirect plasma treatment can be utilized as an efficient alternative method for formaldehyde removal in commercial kitchens, while efficiency or energy yield should be prioritized for optimizing operating conditions.

10.
Int J Mol Sci ; 24(20)2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37894773

RESUMO

This review is devoted to a topic of high interest in recent times-the use of plasma technologies in agriculture. The increased attention to these studies is primarily due to the demand for the intensification of food production and, at the same time, the request to reduce the use of pesticides. We analyzed publications, focusing on research conducted in the last 3 years, to identify the main achievements of plasma agrotechnologies and key obstacles to their widespread implementation in practice. We considered the main types of plasma sources used in this area, their advantages and limitations, which determine the areas of application. We also considered the use of plasma-activated liquids and the efficiency of their production by various types of plasma sources.


Assuntos
Praguicidas , Gases em Plasma , Agricultura , Alérgenos , Sementes
11.
Sci Rep ; 13(1): 15156, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37704648

RESUMO

Metal-organic frameworks (MOFs) are recognized as a desirable class of porous materials for energy storage applications, despite their limited conductivity. In the present study, Co-MOF-71 was fabricated as a high-performance supercapacitor electrode at ambient temperature using a fast and straightforward, one-pot cold plasma method. A supercapacitor electrode based on Co-MOF@rGO was also synthesized by adding reduced graphene oxide (rGO) during processing to increase the capacitance retention and stability after 4000 cycles from 80 to 95.4%. The Co-MOF-71 electrode provided a specific capacitance (Cs) of 651.7 Fg-1 at 1 Ag-1, whereas the Co-MOF@rGO electrode produced a Cs value of 967.68 Fg-1 at 1 Ag-1. In addition, we fabricated an asymmetric device (Co-MOF@rGO||AC) using Co-MOF-rGO as a high-rate positive electrode and activated carbon (AC) as a negative electrode. This hybrid device has a remarkable specific energy and power density. The combination of MOFs with reduced graphene oxide (rGO) in a cold plasma environment resulted in the formation of a three-dimensional nanostructure composed of nanosheets. This nanostructure exhibited an increased number of electroactive sites, providing benefits for energy storage applications.

12.
Skin Res Technol ; 29(8): e13429, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37632194

RESUMO

BACKGROUND: Seborrheic keratoses (SK) is a benign epithelial skin tumor and plasma exeresis is a new technique. AIMS: To compare the efficacy and safety of plasma exeresis and cryotherapy for treating SK. METHODS: This study is a randomized controlled trial (RCT). One side of each patient was randomly treated with plasma exeresis (peak-to-peak voltage of 3.44 kV and a frequency of 62.5 kHz) and the other side with cryotherapy. RESULTS: Thirty-five males were enrolled. At week 3, 37.1 % (N = 13) of lesions treated by plasma exeresis were clear, which was higher than those treated by cryotherapy 17.1% (N = 6). However, this difference was not significant (p-value: 0.06). At week 6, 16 (57.1 %) out of 28 remaining lesions, treated by plasma exeresis were clear, which was significantly higher (p-value: 0.005) than those completely cleared by cryotherapy in 6 out of 29 remaining lesions (20.7%). The mean physician assessment scale score was significantly reduced in both groups in the second follow-up (plasma group first follow-up 0.91 ± 0.89 vs. second follow-up 0.5 ± 0.64 and p-value: 0.0031; cryo group first follow-up 1.4 ± 0.84 vs. second follow-up 1.1 ± 0.72 and p-value: 0.0002). Regarding side effects, no significant difference was seen (p = 0.438). The most common complications in the plasma and cryotherapy groups were erythema (10/19, 52.63%) and hypo pigmentation (5/13, 38.46%). CONCLUSIONS: Both cryotherapy and plasma exeresis are effective. We observed a significantly higher cleared lesions treated with plasma exeresis in 6 weeks and after two sessions.


Assuntos
Ceratose Seborreica , Neoplasias Cutâneas , Masculino , Humanos , Ceratose Seborreica/terapia , Crioterapia/efeitos adversos , Pigmentação
13.
Sci Rep ; 13(1): 7738, 2023 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-37173354

RESUMO

Cold atmospheric plasma has been developed and utilized as a novel technique for skin rejuvenation because of its various effects on cells and living things. This study investigated the accuracy of this claim and any possible side effects of using spark plasma to rejuvenate skin. The present work is the first quantitative investigation using animal models. 12 Wistar rats were divided into two groups for this investigation. To compare the skin's natural process with the treated skin, the first group underwent a single session of plasma therapy, while the second group served as the control group. The back of the necks of the samples was shaved for 20 cm. Before beginning treatment, the MPA9 multifunctional skin tester was used to determine the melanin index, erythema index, and transepidermal water loss (TEWL). The skin's thickness and density were assessed using sonography, and its elasticity index was calculated using a Cutometer. The samples were exposed to plasma radiation in the designated area (in a triangular pattern). The abovementioned signs were examined immediately after the following therapy and at the weekly appointment 2-4 weeks later. Optical spectroscopy was also used to demonstrate the presence of active species. In this study, we found that a plasma spark therapy session significantly boosts skin elasticity, and the ultrasound results revealed a significantly increased skin thickness and density. The plasma increased the amount of skin surface evaporation, erythema, and melanin immediately following the treatment. However, 4 weeks later, it recovered to its former state and did not differ significantly from before the therapy.


Assuntos
Melaninas , Pele , Animais , Ratos , Ratos Wistar , Eritema/etiologia , Elasticidade , Biometria
14.
Sci Rep ; 13(1): 6797, 2023 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-37100818

RESUMO

Cold atmospheric pressure plasma (CAP) has been described as a novel technology with expanding applications in biomedicine and biotechnology. In the present study, we provide a mildly stressful condition using non-lethal doses of CAP (120, 180, and 240 s) and evaluate its potential benefits on the recombinant production of a model protein (enhanced green fluorescent protein (eGFP)) in yeast Pichia pastoris. The measured eGFP fluorescence augmented proportional to CAP exposure time. After 240 s treatment with CAP, the measured fluorescent intensity of culture supernatant (after 72 h) and results of real-time PCR (after 24 h) indicated an 84% and 76% increase in activity and related RNA concentration, respectively. Real-time analysis of a list of genes involved in oxidative stress response revealed a significant and durable improvement in their expression at five h and 24 h following CAP exposure. The improvement of the recombinant model protein production may be partly explained by the impact of the RONS on cellular constituents and altering the expression of specific stress genes. In conclusion, using CAP strategy may be considered a valuable strategy to improve recombinant protein production, and deciphering the molecular background mechanism could be inspiring in the reverse metabolic engineering of host cells.


Assuntos
Pichia , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Pichia/genética , Pichia/metabolismo , Proteínas Recombinantes/metabolismo , Biotecnologia
15.
Lasers Med Sci ; 38(1): 113, 2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37103690

RESUMO

Treatment of skin diseases is important yet challenging. One of the most common skin diseases in women is melasma, which features acquired facial hyperpigmentation. We studied the effect of cold atmospheric nitrogen plasma on this disease. To characterize the nitrogen plasma, we obtained the relative intensity of the species and the plasma temperature and skin temperature during processing at different input powers and gas flows. Patients complaining of melasma were treated with hydroquinone on both sides of the face, and one side was randomly selected for additional nitrogen plasma therapy. Eight treatment sessions of plasma processing were provided 1 week apart, and one follow-up session was scheduled 1 month after the end of treatment. The rate of improvement was scored by a dermatologist in the eighth session and 1 month following the last session using the modified Melasma Area Severity Index (mMASI). Skin biomechanical characteristics such as melanin, cutaneous resonance running time (CRRT), transepidermal water loss (TEWL), and hydration were measured at baseline and during the fourth, eighth, and follow-up sessions. On both sides, we observed a significant decrease in both CRRT and melanin (P < 0.05). TEWL did not change on both sides, while hydration decreased significantly only on the side to which hydroquinone was applied in isolation (P < 0.05). According to clinical scores, on both sides, we had significant improvement. On the side that plasma was not applied, the percentage reduction of pigmentation (mMASI) in the eighth and follow-up sessions in comparison with the baseline was 5.49 ± 8.50% and 33.04 ± 9.17%, respectively, while on the other side, these figures were 20.57 ± 6.64% and 48.11 ± 11%. For melanin, these figures were 13.84 ± 4.84% and 18.23 ± 7.10% on the hydroquinone side and 21.56 ± 3.13% and 23.93 ± 3.02% on the other side. According to these results, nitrogen plasma can safely complement topical hydroquinone to improve clinical outcomes when treating melasma without causing stratum corneum damage or skin discomfort, though confirmatory studies are needed.


Assuntos
Hidroquinonas , Melanose , Feminino , Humanos , Hidroquinonas/uso terapêutico , Hidroquinonas/efeitos adversos , Melaninas , Melanose/tratamento farmacológico , Resultado do Tratamento
16.
J Lasers Med Sci ; 14: e70, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38318219

RESUMO

Introduction: The current study aimed to assess the effect of non-thermal plasma (NTP) on the pushout bond strength (PBS) of epoxy resin and tricalcium silicate-based endodontic sealers. Methods: Forty single-canal extracted teeth were decoronated at the coronal region, underwent root canal preparation, and were assigned to four groups (n=10) for the application of AH26 sealer, NTP+AH26 (P-AH26), Endoseal TCS sealer, and NTP+Endoseal TCS sealer (P-TCS). The root canals were sectioned into 1 mm slices, and the PBS value was measured in a universal testing machine. Data were analyzed by the Friedman, Kruskal-Wallis, and Dunn tests (P<0.05). Results: The PBS of TCS and P-TCS groups was not significantly different (P>0.05). The PBS of the P-AH26 group was significantly lower than that of the AH26 group in the middle third (P<0.05). The PBS of the AH26 group was higher than the other groups in all sections. The PBS in the apical third was lower than other sections in all groups (P<0.05). Conclusion: NTP had no significant effect on the PBS of Endoseal TCS. NTP significantly decreased the PBS of AH26 sealer in the middle third but had no significant effect on its bond strength in other sections.

17.
Materials (Basel) ; 15(23)2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36500046

RESUMO

Hydrophobic and oleophilic Si-based cotton fabrics have recently gained a lot of attention in oil/water separation due to their high efficiency. In this study, we present the effect of O2 plasma pre-treatment on the final properties of two Si-based cotton membranes obtained from dip coating and plasma polymerization, using polydimethylsiloxane (PDMS) as starting polymeric precursor. The structural characterizations indicate the presence of Si bond on both the modified cotton surfaces, with an increase of the carbon bond, assuring the success in surface modification. On the other hand, employing O2 plasma strongly changes the cotton morphology, inducing specific roughness and affecting the hydrophobicity durability and separation efficiency. In particular, the wettability has been retained after 20 laundry tests at 40 °C and 80 °C, and, for separation efficiency, even after 30 cycles, an improvement in the range of 10-15%, both at room temperature and at 90 °C can be observed. These results clearly demonstrate that O2 plasma pre-treatment, an eco-friendly, non-toxic, solvent-free, and one-step method for inducing specific functionalities on surfaces, is very effective in enhancing the oil/water separation properties for Si-based cotton membranes, especially in combination with plasma polymerization procedure for Si-based deposition.

18.
Case Rep Dermatol ; 14(3): 344-349, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36466755

RESUMO

Nowadays, cold atmospheric plasma jet (CAP-jet) shows interesting results in the dermatology sector, particularly focusing on wound healing and antimicrobial properties. The purpose of this case report is to present a nonthermal atmospheric pressure plasma treatment as a novel therapy for venous ulcers. The plasma consists of ionized helium gas that is produced by a high-voltage (4.5 kV) and high-frequency power supply (22 kHz). We here present a 65-year-old man with a slow-healing ulcer on the right lower limb. The CAP was applied to the ulcer twice a week for four consecutive weeks and the patient was followed for 6 weeks. The amount of exudate, ulcer size, and wound grading were determined weekly. The results showed that exudate from the ulcer significantly reduced in the first week after complete treatment, the wound grading of the ulcer improved by the second week, and the size of the ulcer significantly decreased after 2 weeks. The ulcer entirely healed after 4 weeks without any signs of infection. This case study demonstrates that applying CAP-jet can decrease the bacterial load on the ulcer site and stimulate tissue regeneration concurrently. This increases the speed of the healing process.

19.
J Am Soc Mass Spectrom ; 33(6): 907-916, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35522602

RESUMO

Many studies are focused on using plasma in mass spectrometry as an ionization source or postionization method. In this study, the effect of plasma treatment in the sample preparation step of desorption electrospray ionization (DESI) has been investigated. The plasma treatment of polar samples, including morphine, codeine, captopril, theophylline, fructose, and amphiphilic compounds such as phosphatidylethanolamine (PE) in E. coli bacteria, as well as nonpolar compounds, including thebaine, papaverine, and noscapine, has been followed for ionization efficiency in DESI technique. An atmospheric-pressure glow discharge plasma (GDP) along with the electrospray ionization technique is examined. Plasma treatment before ambient ionization has a dramatic effect on polar and nonpolar sample signals in DESI-TOF mass spectrometry. The intensity of the mass spectrum shows an increase of 1.9-3.4 times for polar compounds, 2.1-2.5 times for nonpolar compounds, and 3.0 times for PE in E. coli bacteria (N = 4). Plasma is a source of reactive atoms, molecules, ions, radicals, and ultraviolet radiation. Plasma surface treatment before DESI analysis by energetic species through momentum/energy transfer yields higher energy surface molecules, leading to more/easier desorption. Under optimal treatment conditions, an improved ion signal intensity is observed without any fragmentation, decomposition, or chemical changes. Ion signals are increased possibly by both increased ionization through protonation of molecules and enhanced subsequent desorption during DESI analysis.


Assuntos
Espectrometria de Massas por Ionização por Electrospray , Raios Ultravioleta , Pressão Atmosférica , Escherichia coli , Íons , Espectrometria de Massas por Ionização por Electrospray/métodos
20.
Lasers Med Sci ; 37(1): 181-191, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33420853

RESUMO

This randomized controlled study aimed to investigate the efficacy and safety of multiple treatment sessions of pulsed non-thermal atmospheric pressure nitrogen plasma compared with long-pulsed Nd:YAG laser for hand rejuvenation. To optimize the nitrogen plasma mode for rejuvenation, the relative intensity of reactive species and skin temperature was compared at different input powers and time periods. Twenty-five patients with mild-moderate photodamaged skin were recruited; one hand was randomly selected for eight weekly treatment sessions with plasma (two passes), while the other was subjected to three monthly treatments with laser (until erythema became obvious). A blinded dermatologist scored the mean wrinkle and dyschromia improvement at 1 and 2 months after the first treatment and 1 and 3 months after the last treatment. The patients' satisfaction and the biomechanical characteristics of the skin including cutaneous resonance running time (CRRT), melanin, transepidermal water loss (TEWL), and hydration were evaluated. Clinically, both methods gave rise to a similar, significant improvement in wrinkles (49.09 ± 19.18% and 39.32 ± 18.21% after plasma and laser, respectively) and dyschromia (45.00 ± 26.32% and 30.62% ± 24.99% after plasma and laser, respectively) (P < 0.05). A significant decrease in CRRT and melanin was seen following treatment with either method (P < 0.05). Notably, plasma therapy led to a significant decrease in TEWL and boosted skin hydration. This is while laser therapy augmented the TEWL and reduced skin hydration. Our findings corroborate that cold plasma is as effective and safe as long-pulsed Nd:YAG laser, with less discomfort and dryness during treatment. The protocol was approved by the Iranian Registry of Clinical Trials. IRCT20160320027109N4. Registered 9 April 2019 (This manuscript is only a part of this registered project.).


Assuntos
Lasers de Estado Sólido , Envelhecimento da Pele , Humanos , Irã (Geográfico) , Lasers de Estado Sólido/uso terapêutico , Nitrogênio , Rejuvenescimento , Resultado do Tratamento
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