Response surface methodology (RSM) for optimizing ozone-assisted process parameters for formaldehyde removal.

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.

Effect of cold atmospheric plasma torch distance on the microbial inactivation and sensorial properties of ready-to-eat olivier salad.

This study aimed to investigate the effect of the cold atmospheric plasma torch (CAPT) nozzle distance from the surface of Olivier salad and the treatment time in the reduction of microbial load and sensory properties of the product simultaneously. In this study, the CAPT nozzle was placed at 3, 5, and 7 cm distances from the surface of the Olivier salad, and its efficiency in inactivating the microbial population, decimal reduction time (D-value), and sensory evaluation of the product were evaluated. The results showed that reducing the distance and increasing the plasma treatment time (30, 60, 90, and 120 s) both reduced the microbial load of the product. The maximum inactivation and the minimum D-value are related to the 3 cm distance for 120 s, which has been 3.77, 2.91, and 1.52 log CFU/g for Coliform, Total viable count (TVC), mold and yeast, respectively. The lowest D-value was related to Coliform (4.41 s). CAPT treatment had no significant sensible effect on the product's sensory characteristics compared to the control sample. The treated sample at a 3 cm distance for 90 s and the microbial reduction to an acceptable amount and high acceptancy from sensory evaluators were selected as the superior treatment in this study. Also, the results showed that CAPT could be used successfully in ready-to-eat (RTE) products.

Treatment of Chronic Venous Ulcer with Cold Atmospheric Plasma Jet.

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.

Effect of low-pressure cold plasma processing on decontamination and quality attributes of Saffron (Crocus sativus L.).

This study investigated the microbial decontamination of saffron using the low-pressure cold plasma (LPCP) technology. Therefore, other quality characteristics of saffron that create the color, taste, and aroma have also been studied. The highest microbial log reduction was observed at 110 W for 30 min. Total viable count (TVC), coliforms, molds, and yeasts log reduction were equal to 3.52, 4.62, 2.38, and 4.12 log CFU (colony-forming units)/g, respectively. The lowest decimal reduction times (D-values) were observed at 110 W, which were 9.01, 3.29, 4.17, and 8.93 min for TVC, coliforms, molds, and yeasts. LPCP treatment caused a significant increase in the product's color parameters (L*, a*, b*, ΔE, chroma, and hue angle). The results indicated that the LPCP darkened the treated stigma's color. Also, it reduced picrocrocin, safranal, and crocin in treated samples compared to the untreated control sample (p < .05). However, after examining these metabolites and comparing them with saffron-related ISO standards, all treated and control samples were good.

Oral Cells-On-Chip: Design, Modeling and Experimental Results.

Recent advances in periodontal studies have attracted the attention of researchers to the relation between oral cells and gum diseases, which is a real threat to overall human health. Among various microfabrication technologies, Complementary Metal Oxide Semiconductors (CMOSs) enable the development of low-cost integrated sensors and circuits for rapid and accurate assessment of living cells that can be employed for the early detection and control of periodontal diseases. This paper presents a CMOS capacitive sensing platform that can be considered as an alternative for the analysis of salivatory cells such as oral neutrophils. This platform consists of two sensing electrodes connected to a read-out capacitive circuitry designed and fabricated on the same chip using Austria Mikro Systeme (AMS) 0.35 µm CMOS process. A graphical user interface (GUI) was also developed to interact with the capacitive read-out system and the computer to monitor the capacitance changes due to the presence of saliva cells on top of the chip. Thanks to the wide input dynamic range (IDR) of more than 400 femto farad (fF) and high resolution of 416 atto farad (aF), the experimental and simulation results demonstrate the functionality and applicability of the proposed sensor for monitoring cells in a small volume of 1 µL saliva samples. As per these results, the hydrophilic adhesion of oral cells on the chip varies the capacitance of interdigitated electrodes (IDEs). These capacitance changes then give an assessment of the oral cells existing in the sample. In this paper, the simulation and experimental results set a new stage for emerging sensing platforms for testing oral samples.

In vivo study of the effects of a portable cold plasma device and vitamin C for skin rejuvenation.

Nowadays, cold atmospheric plasma shows interesting results in dermatology. In the present study, a new portable cold plasma was designed for plasma skin rejuvenation (PSR) purposes. This device is safe and easy to use at beauty salons and homes. The effects of this device were investigated on the rat skins. Also, as a new method to improve PSR results, vitamin C ointment was combined with plasma. In this study, there were four groups of 5 Wistar rats. The first group received vitamin C ointment, the second received 5 min of high-voltage plasma, and the third and the fourth groups received 5 min of high- and low-voltage plasma and vitamin C ointment. This process was done every other day (3 sessions per week) for 6 weeks. To evaluate the thermal effect of plasma, the skin temperature was monitored. Also, the presence of reactive species was demonstrated by the use of optical spectroscopy. In addition, mechanical assays were performed to assess the effect of plasma and vitamin C on the tissue's mechanical strength. The mechanical assays showed a positive impact of plasma on the treated tissue compared to the control group. Also, changes in the collagen level and thickness of the epidermal layer were examined in histological studies. The results indicated an increase in collagen levels after using plasma alone and an accelerated skin reaction after using vitamin C combined with plasma therapy. The epidermal layer's thickness increased after applying high-voltage plasma, which indicates an increase in skin elasticity. This study demonstrates the positive effect of using the portable plasma device with vitamin C ointment on effective parameters in skin rejuvenation.

The evaluation of efficacy of atmospheric pressure plasma in diabetic ulcers healing: A randomized clinical trial.

The aim of this study is to evaluate the efficacy and safety of cold atmospheric plasma (CAP) as a novel therapy for diabetic foot ulcers. This was an investigator-blinded, randomized controlled trial of 14 weeks (6 weeks of treatment and 8 weeks of follow-up). Twenty patients with diabetic foot ulcers were divided into two groups: the control group receiving standard wound care and the plasma group, which received CAP twice a week for six consecutive weeks in addition to standard wound care. The ulcer size, amount of exudate, and wound grading were determined weekly. Cold plasma was produced by applying a high voltage (4.5 kV) and a high frequency (22 kHz) to helium gas. Exudate from wounds treated with CAP showed a significant reduction in the third week after complete treatment (p = 0.039). The wound grading of the ulcers improved by the sixth week (p = 0.019), and the sizes of ulcers significantly decreased in the plasma group at the end of the treatment period (p = 0.007). In this randomized clinical trial, CAP was an effective treatment option for diabetic foot ulcers in terms of wound surface reduction and antibacterial effects.

Treatment of starch films with a glow discharge plasma in air and O2 at low pressure.

In this study, the effect of different cold plasma treatments was investigated as a novel method for the modification of starch film properties. The films were prepared from wheat starch using a solvent casting method and then treated with air and O2 glow discharge plasma at different durations (4, 8, and 12 min). A significant increase in the hydrophilicity of the films was observed due to the formation of oxygen-containing groups after plasma treatment. Fourier transform infrared analysis illustrated a decrease in C-H groups that caused an increase in C-O and C-O-C groups in air-treated films and carbonyl groups in O2-treated films. The surface roughness of the treated films increased from 17.6 nm to 22.5 and 20.6 nm after air and O2 treatments, respectively. Plasma treatments decreased oxygen permeability of the films but no significant difference in the water vapor permeability was observed. After plasma treatment, tensile strength of films was improved due to crosslinking and etching at the surface, although elongation at break remains unchanged.

Real diesel engine exhaust emission control: indirect non-thermal plasma and comparison to direct plasma for NOX, THC, CO, and CO2.

Recently, diesel engine exhaust emission control by non-thermal plasma (NTP) technology has been shown to be promising. However, carbon and soot deposition on the inner surface of the NTP reactor for direct plasma processing decreased the efficiency of the plasma process throughout the experiments. In the present work, the feasibility of indirect plasma processing was investigated as an innovative and novel method compared to direct plasma processing. Air was directed through an NTP at an applied voltage of VP-P = 7 kV and a flow rate of 1-4 L/min, and then, it was combined with engine exhaust gas at a flow rate of 5 L/min. In this case, the maximum conversion of NOX was 64.9% at 4 L/min. However, for direct plasma processing at 5 L/min, NO conversion was 58%, which proves that the indirect NTP process can decrease NOX concentration effectively. The maximum conversion for unburned hydrocarbon (UHC), carbon monoxide (CO) and carbon dioxide (CO2) was obtained as 2%, 4% and 0.7% at 4, 2 and 3 L/min in indirect plasma processing; While their remove rate for direct plasma processing was 16.3%, -0.5% and 13.2%, respectively.

Multi-scale segmentation in GBM treatment using diffusion tensor imaging.

Glioblastoma (GBM) is the commonest primary malignant brain tumor in adults, and despite advances in multi-modality therapy, the outlook for patients has changed little in the last 10 years. Local recurrence is the predominant pattern of treatment failure, hence improved local therapies (surgery and radiotherapy) are needed to improve patient outcomes. Currently segmentation of GBM for surgery or radiotherapy (RT) planning is labor intensive, especially for high-dimensional MR imaging methods that may provide more sensitive indicators of tumor phenotype. Automating processing and segmentation of these images will aid treatment planning. Diffusion tensor magnetic resonance imaging is a recently developed technique (DTI) that is exquisitely sensitive to the ordered diffusion of water in white matter tracts. Our group has shown that decomposition of the tensor information into the isotropic component (p - shown to represent tumor invasion) and the anisotropic component (q - shown to represent the tumor bulk) can provide valuable prognostic information regarding tumor infiltration and patient survival. However, tensor decomposition of DTI data is not commonly used for neurosurgery or radiotherapy treatment planning due to difficulties in segmenting the resultant image maps. For this reason, automated techniques for segmentation of tensor decomposition maps would have significant clinical utility. In this paper, we modified a well-established convolutional neural network architecture (CNN) for medical image segmentation and used it as an automatic multi-sequence GBM segmentation based on both DTI image maps (p and q maps) and conventional MRI sequences (T2-FLAIR and T1 weighted post contrast (T1c)). In this proof-of-concept work, we have used multiple MRI sequences, each with individually defined ground truths for better understanding of the contribution of each image sequence to the segmentation performance. The high accuracy and efficiency of our proposed model demonstrates the potential of utilizing diffusion MR images for target definition in precision radiation treatment planning and surgery in routine clinical practice.

Prolonging shelf life of chicken breast fillets by using plasma-improved chitosan/low density polyethylene bilayer film containing summer savory essential oil.

Cold plasma assay was potentially useful persuade surface modification. In this study, antimicrobial properties of chitosan and low density polyethylene bilayer film with method cold plasma incorporated with summer savory essential oil (SEO) (1, 2 and 3%) for extending shelf life of chicken breast fillets was investigated. Moreover, mechanical and physical properties of film were assessed. Result showed that plasma treatment could improvement properties film and increase shelf life processing. After plasma treatment chitosan/polyethylene film containing 3% summer savory essential oil decreased water vapor permeability and oxygen transmission rate chitosan film. Addition of summer savory essential oil to the two-layer film, also improved tensile strength and elongation at break of film. The bilayer film with 3% of essential oil treatment cold plasma was chosen for microbial analysis during storage. All samples plasma-treated, films for this study included polyethylene (PE), bilayer of polyethylene and chitosan (PE/Ch) and Chitosan containing essential oil in direct contact (D) and gas phase (G). Result showed that shelf life of fillets were extended in direct contact and gas phase treatments to 13 days at refrigerator. It was 6 days for polyethylene and 8 days for Chitosan treatments. Essential oil incorporated film also decreased thiobarbitoric acid value of sample during storage. Cold plasma has a high potential in active packaging and food preservation.

Modifications of protein-based films using cold plasma.

In this research, the influence of different cold plasma treatments was investigated as a novel method for modification of protein film properties. The films were prepared from whey and gluten proteins using solvent casting method and then treated with vacuum low-pressure glow plasma using air and argon gases at 50 KW for 5, 10, and 15 min and further analyzed mechanically and physicochemically. The images of atomic force microscopy (AFM) revealed a significant increase in roughness of whey protein films after plasma treatment, while the roughness of treated gluten films diminished dramatically. Furthermore, the tensile strength of films improved significantly after 10 min of process, from 6.902 to 10.772 MPa and from 1.854 to 2.571 MPa for whey protein and gluten films, respectively. Introduction of functional groups such as CO and OC bonds plus cross link creation was observed by FTIR which could lead to changes in different film features. Although gas permeability of both edible polymers decreased significantly, other parameters including solubility and water vapor permeability of control and plasma treated (PT) films did not show dramatic differences. Therefore, the optimum condition and time of low-pressure glow plasma has the potential for modifying protein films.

Decomposition of high concentration benzene (produced in paper and painting industries) and its byproducts, methane and carbon dioxide, using plate gliding arc.

High concentration benzene production in paper and painting industries is a restrictive problem in production line of companies. In this study, removal of high concentrated benzene produced in painting companies was investigated using a Plate Gliding Arc (PGA) reactor. Decomposition of methane and carbon dioxide as the most predominate byproducts of benzene decomposition was also studied using (PGA) reactor. The effect of several parameters such as input power, feed gas flow rate, type of carrier gas, and [CH4/CO2] flow ratio was studied by two series of experiments. The results show significant conversion (>70%) of high concentration benzene (74000ppm) without using any catalyst. Selectivity of CO2 and CO was 88% and 10% respectively showing complete oxidation of benzene. The maximum conversion of CH4 and CO2 reached 52% and 69%, respectively by using optimum ratio of 3:4. The main results of this study proved removal of high concentration benzene using a low-energy-density reactor. Furthermore, an optimum value for efficient conversion of methane and carbon dioxide was achieved and the energy density of the PGA reactor was evaluated, which shows a good promise for industrial applications.

Degradation of 4-chlorophenol in aqueous solution by dielectric barrier discharge system: effect of fed gases.

A dielectric barrier discharge system with a discharging zone where degradation processes happen is designed to remove 4-chlorophenol from water. The removal of 4-chlorophenol was influenced by the processing parameters such as gas flow rate, flow ratio of oxygen and argon, applied voltage and total applied power. Increasing the power or gas flow rates within a certain range enhanced the removal efficiency. 99% of 4-chlorophenol was removed in 6.5 min at reactor's efficient point which is set by adjusting the flow ratio of introduced gases and voltage. The removal percent was about 95% at 5 min of non-thermal plasma treatment with peak voltage of 10 kV and oxygen and argon flow rate of 20 SCCM and 200 SCCM respectively. Then by adjusting the flow ratios in order to find the optimum point. At this point the efficiency reached its peak due to excessive introduction oxygen gas which results in production of more oxidative agents. HPLC and GC-MS analysis have been carried out in order to investigate the by-products of degradation process. After 6.5 min of treatment at efficient point of degradation reactor, a 64% decrease in COD index has been indicated.

Cold low pressure O2 plasma treatment of Crocus sativus: An efficient way to eliminate toxicogenic fungi with minor effect on molecular and cellular properties of saffron.

In this study cold low pressure radiofrequency oxygen plasma was used for the first time to inactivate toxicogenic fungi proliferation on saffron. Varieties of plasma produced reactive oxygen species which were investigated by optical emission spectroscopy. The data were indicative of the absence of UV radiation. Effects of plasma treatment on antioxidant activity, metabolic content, colour, odour and flavour parameters and physical impact on saffron were investigated. A range of plasma powers and exposure times were assayed in suppression of fungal growth. Amongst which power of 60 W for 15 min was used to eradicate Aspergillus and other microorganisms. The ferric reducing antioxidant power was changed from 1778.21 to 1674.25 mM/g dry weight following plasma treatment. Moreover, crocin ester, picrocrocin and safranal metabolites reduced insignificantly. Additionally, plasma had no significant impact on colour, odour and flavour of saffron.

Comparative investigation of argon and argon/oxygen plasma performance for Perchloroethylene (PCE) removal from aqueous solution: optimization and kinetic study.

PURPOSE: The aim of this study is evaluation of the perchloroethylene degradation from aqueous solutions by non-thermal plasma produced in dielectric barrier discharge reactor in two different scenarios: first plasma generated with 225 cc/min mixture of oxygen and argon flow (12% gas ratio of O2/Ar), and in the second scenario plasma generated with 225 cc/min of pure argon gas. METHODS: Design studies were performed using response surface methodology and central composite design. All experiments with the selected levels of independent parameters including the initial concentration of perchloroethylene (5-100 mg/L), voltage (20-5 kv) and contact time (15-180 s) was implemented, and 29 tests were proposed by using response surface methodology and central composite design was performed in two experimental scenarios. RESULTS: Results showed that the Pseudo first-order kinetics coefficient of perchloroethylene degradation in the mixture of oxygen and argon and pure argon scenario under the optimum conditions were 0.024 and 0.016 S-1 respectively. Results conveyed that in order to achieve the highest removal efficiency (100%), the values of contact time, perchloroethylene concentration and voltage variables were predicted 169.55 s, 74.3 mg/l, 18.86 kv respectively in mixture of oxygen and argon scenario and also were predicted 203 s, 85.22 mg/l, 20.39 kv respectively in pure argon scenario. CONCLUSIONS: In the recent study dielectric barrier discharge was an efficient method for perchloroethylene removal with both oxygen an argon mixture and pure argon as input gas. Both input voltage and reaction time has positive effect on perchloroethylene removal; but initial perchloroethylene concentration has negative effect on perchloroethylene removal. Comparison of two plasma scenarios with different input gas shown that plasma generated by mixture of oxygen and argon gas was more powerful and had higher removal efficiency and degradation kinetics than the plasma generated by pure argon gas.

Application of cold plasma to develop carboxymethyl cellulose-coated polypropylene films containing essential oil.

This study was aimed to develop and characterize carboxymethyl cellulose-coated polypropylene (PP/CMC) films with Zataria multiflora essential oil (ZEO) as a new antimicrobial food packaging. For better attachment of CMC on polypropylene (PP) film surface, atmospheric plasma pretreatment was used. Results showed the formation of polar groups such as CO and OH in the PP surface following the plasma treatment. Plasma-treated PP had rougher surfaces and their contact angle reduced from 88.92° to 52.15° indicating increased surface hydrophilicity. Plasma-treated PP/CMC films showed lower water vapor permeability (WVP) and higher tensile strength compared to untreated bilayer films. Results revealed that antimicrobial PP/CMC films with higher content of ZEO had lower WVP, but was more sensitive to breakage. Antimicrobial characteristics in the direct contact and vapor phase represented great inhibition for all the tested bacteria. Our findings suggest that plasma-treated PP/CMC films have the potential for application in food antimicrobial packaging.

Evaluating the Anti-nociceptive and Anti-inflammatory Effects of Ketotifen and Fexofenadine in Rats.

PURPOSE: As H1 and H3 receptors' roles has been defined in peripheral pains in some papers and because histamine is known for its role in inflammatory responses; this study investigated the possible analgesic and anti-inflammatory effects of ketotifen and fexofenadine as relatively safe long acting anti histamines in both chronic chemical pain and acute inflammation in rats. METHODS: In this study, male Sprague-Dawley rats weighing 225-250 grams were used. In order to evaluate the chemical chronic pain, sub-plantar injection of formalin applied and the pain scores were recorded every 15 seconds during 60 minutes. Carrageenan injection to the right hind paw was used for induction of acute inflammation and the paw edema was measured every 60 minutes for 4 hours. RESULTS: Based on the results, both ketotifen and fexofenadine were able to significantly diminish chemical acute and chronic pain as well as inflammation in comparison with the control group and the effects were acceptable according to the standard treatment. Both effects for fexofenadine started later than those of ketotifen. CONCLUSION: According to the outcomes of the study, ketotifen and fexofenadine demonstrated significant analgesic and anti-inflammatory characteristics in both models of chemical pain and acute inflammation in laboratory animals.

Investigating effects of atmospheric-pressure plasma on the process of wound healing.

Cold atmospheric-pressure plasma jets (APPJ) have excellent applications in biomedicine. Advantages of APPJ include lack of need for vacuum systems, capability of operation for a long time, and safe to be directly touched by living tissues such as a human body. In this study, an APPJ was generated by a dielectric barrier and applied for the treatment of chemical wounds. This APPJ worked with argon and was driven by high-voltage pulses. This paper compares the spontaneous healing of wounds and a stimulated healing using daily APPJ treatment. Biological data, such as hematological, biochemical, and histological parameters, were remarked. The mortality and morbidity of the untreated samples were reported after 20 days in comparison with the plasma-treated samples, which were alive after these days. Experimental results demonstrated that an increase in the oxidative stress could result in the decreased destruction of lesions by controlling the infection growth. These results were related to the presence of reactive oxygen species and reactive nitrogen species in the plasma volume, which were detected by optical emission spectroscopy.

Extra-axial medulloblastoma in cerebello-pontine angle: A report of a rare case with literature review.

Medulloblastoma is quite uncommon in the adult population and even rarer in extra-axial site in cerebello-pontine (CP) angle. In this report, a 23-year-old male patient with a two month history of deafness, nausea, vomiting and ataxia is presented. Clinical and radiological findings demonstrated a heterogeneously enhanced extra-axial lesion in the right CP angle. Total excision was performed and the histopathological features of medulloblastoma were confirmed. After surgery, the patient had no neurological deficit and the audiometric findings were improved. In addition, he underwent adjuant radiotherapy and no sign of metastatic mass was observed in follow-up spinal cord MRI. Although extremely rare, medulloblastoma must be considered in the differential diagnosis of extra-axial CP angle lesions.