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1.
PLoS One ; 19(5): e0303359, 2024.
Article in English | MEDLINE | ID: mdl-38728321

ABSTRACT

As-produced carbon nanotubes contain impurities which can dominate the properties of the material and are thus undesired. Herein we present a multi-step purification treatment that combines the use of steam and hydrochloric acid in an iterative manner. This allows the reduction of the iron content down to 0.2 wt. % in samples of single-walled carbon nanotubes (SWCNTs). Remarkably, Raman spectroscopy analysis reveals that this purification strategy does not introduce structural defects into the SWCNTs' backbone. To complete the study, we also report on a simplified approach for the quantitative assessment of iron using UV-Vis spectroscopy. The amount of metal in SWCNTs is assessed by dissolving in HCl the residue obtained after the complete combustion of the sample. This leads to the creation of hexaaquairon(III) chloride which allows the determination of the amount of iron, from the catalyst, by UV-Vis spectroscopy. The main advantage of the proposed strategy is that it does not require the use of additional complexing agents.


Subject(s)
Hydrochloric Acid , Iron , Nanotubes, Carbon , Spectrophotometry, Ultraviolet , Spectrum Analysis, Raman , Steam , Nanotubes, Carbon/chemistry , Iron/analysis , Iron/chemistry , Hydrochloric Acid/chemistry , Spectrum Analysis, Raman/methods
2.
Int J Mol Sci ; 25(9)2024 Apr 26.
Article in English | MEDLINE | ID: mdl-38731949

ABSTRACT

To enrich the properties of polylactic acid (PLA)-based composite films and improve the base degradability, in this study, a certain amount of poly(propylene carbonate) (PPC) was added to PLA-based composite films, and PLA/PPC-based composite films were prepared by melt blending and hot-press molding. The effects of the introduction of PPC on the composite films were analyzed through in-depth studies on mechanical properties, water vapor and oxygen transmission rates, thermal analysis, compost degradability, and bacterial inhibition properties of the composite films. When the introduction ratio coefficient of PPC was 30%, the tensile strength of the composite film increased by 19.68%, the water vapor transmission coefficient decreased by 14.43%, and the oxygen transmission coefficient decreased by 18.31% compared to that of the composite film without PPC, the cold crystallization temperature of the composite film increased gradually from 96.9 °C to 104.8 °C, and PPC improved the crystallization ability of composite film. The degradation rate of the composite film with PPC increased significantly compared to the previous one, and the degradation rate increased with the increase in the PPC content. The degradation rate was 49.85% and 46.22% faster on average than that of the composite film without PPC when the degradation was carried out over 40 and 80 days; the composite film had certain inhibition, and the maximum diameter of the inhibition circle was 2.42 cm. This study provides a strategy for the development of PLA-based biodegradable laminates, which can promote the application of PLA-based laminates in food packaging.


Subject(s)
Polyesters , Propane/analogs & derivatives , Tensile Strength , Polyesters/chemistry , Polypropylenes/chemistry , Food Packaging/methods , Steam , Polymers/chemistry , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Temperature
3.
Molecules ; 29(9)2024 Apr 27.
Article in English | MEDLINE | ID: mdl-38731511

ABSTRACT

Alginate films plasticized with glycerol and enriched in raspberry and/or black currant seed oils were prepared via casting solution techniques. The intention was to create active films for food packaging where antioxidants in a film would deactivate oxidants in a packed product or its surroundings, improving conditions inside packaging and extending the shelf life of such a product. The prepared materials were characterized by physicochemical, spectroscopic, mechanical, water vapor transmission (WVTR), and antioxidant activity analysis. Infrared spectra of the alginate films with oils were similar to those without the additive; the band with a maximum at about 1740 cm-1 stood out. The prepared materials with oils were thicker, contained less water, were more yellow, and were less permeable to water vapor. Moreover, the presence of the oil in the films resulted in a slightly lower Young's modulus and lower stress at break values but higher strain at break. The antioxidant capacity of raspberry seed oil itself was about five times higher than that of black currant seed oil, and a similar trend was noticed for films modified with these oils. The results indicated that both oils could be used as active substances with antioxidant properties in food packaging.


Subject(s)
Alginates , Antioxidants , Food Packaging , Plant Oils , Ribes , Rubus , Seeds , Food Packaging/methods , Alginates/chemistry , Antioxidants/chemistry , Antioxidants/pharmacology , Plant Oils/chemistry , Seeds/chemistry , Rubus/chemistry , Ribes/chemistry , Steam
4.
Int J Biol Macromol ; 267(Pt 1): 131406, 2024 May.
Article in English | MEDLINE | ID: mdl-38582472

ABSTRACT

Starch and plant fibers are abundant natural polymers that offer biodegradability, making them potential substitutes for plastics in certain applications, but are usually limited by its high hydrophilicity, and low mechanical performance. To address this issue, polylactic acid (PLA) is blended with cellulose and chitosan to create a waterproof film that can be applied to starch-fiber foaming biodegradable composites to enhance their water resistance properties. Here, plant fibers as a reinforcement is incorporated to the modified starch by foaming mold at 260 °C, and PLA based hydrophobic film is coated onto the surface to prepare the novel hydrophobic bio-composites. The developed bio-composite exhibits comprehensive water barrier properties, which is significantly better than that of traditional starch and cellulose based materials. Introducing PLA films decreases water vapor permeability from 766.83 g/m2·24h to 664.89 g/m2·24h, and reduce hysteresis angles from 15.57° to 8.59° within the first five minutes after exposure to moisture. The water absorption rate of PLA films also decreases significantly from 12.3 % to 7.9 %. Additionally, incorporating hydrophobic films not only enhances overall waterproof performance but also improves mechanical properties of the bio-composites. The fabricated bio-composite demonstrates improved tensile strength from 2.09 MPa to 3.53 MPa.


Subject(s)
Hydrophobic and Hydrophilic Interactions , Polyesters , Starch , Tensile Strength , Water , Polyesters/chemistry , Starch/chemistry , Water/chemistry , Permeability , Chitosan/chemistry , Cellulose/chemistry , Steam , Surface Properties
5.
Int J Biol Macromol ; 267(Pt 1): 131135, 2024 May.
Article in English | MEDLINE | ID: mdl-38574914

ABSTRACT

The study involves the preparation and characterization of crosslinked-carboxymethyl cellulose (CMC) films using varying amounts of citric acid (CA) within the range 5 %-20 %, w/w, relative to the dry weight of CMC. Through techniques such as Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, carbonyl content analysis, and gel fraction measurements, the successful crosslinking between CMC and CA is confirmed. The investigation includes an analysis of chemical structure, physical and optical characteristics, swelling behavior, water vapor transmission rate, moisture content, and surface morphologies. The water resistance of the cross-linked CMC films exhibited a significant improvement when compared to the non-crosslinked CMC film. The findings indicated that films crosslinked with 10 % CA demonstrated favorable properties for application as edible coatings. These transparent films, ideal for packaging, prove effective in preserving the quality and sensory attributes of fresh bananas, including color retention, minimized weight loss, slowed ripening through inhibiting amyloplast degradation, and enhanced firmness during storage.


Subject(s)
Carboxymethylcellulose Sodium , Citric Acid , Edible Films , Food Packaging , Musa , Carboxymethylcellulose Sodium/chemistry , Citric Acid/chemistry , Food Packaging/methods , Musa/chemistry , Steam , Cross-Linking Reagents/chemistry , Spectroscopy, Fourier Transform Infrared , Water/chemistry , Food Preservation/methods
6.
Molecules ; 29(7)2024 Mar 29.
Article in English | MEDLINE | ID: mdl-38611810

ABSTRACT

A single combi oven, known for its versatility, is an excellent choice for a variety of chicken soup preparations. However, the impact of universal steam ovens on the flavor quality of chicken soup remains unclear. This study aimed to explore the impact of different cooking methods on the aroma and taste of chicken soup. Three cooking methods with various stewing times were compared: ceramic pot (CP), electric pressure cooker (EPC), and combi oven (CO). Analyses were conducted using electron-nose, electron-tongue, gas chromatography-ion mobility spectrometry (GC-IMS), automatic amino acid analysis, and chemometric methods. A total of 14 amino acids, including significant umami contributors, were identified. The taste components of CP and CO chicken soups were relatively similar. In total, 39 volatile aroma compounds, predominantly aldehydes, ketones, and alcohols, were identified. Aldehydes were the most abundant compounds, and 23 key aroma compounds were identified. Pearson's correlation analyses revealed distinct correlations between various amino acids (e.g., glutamic acid and serine) and specific volatile compounds. The aroma compounds from the CP and CO samples showed similarities. The results of this study provide a reference for the application of one-touch cooking of chicken soup in versatile steam ovens.


Subject(s)
Antifibrinolytic Agents , Odorants , Animals , Chickens , Steam , Taste , Gas Chromatography-Mass Spectrometry , Amino Acids , Aldehydes , Cooking
7.
Food Res Int ; 185: 114292, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38658072

ABSTRACT

The synthetic, non-renewable nature and harmful effects of plastic packaging have led to the synthesis of eco-friendly renewable bio-nanocomposite film. The present work was aimed at the formulation and characterization of bio-nanocomposite film using soybean meal protein, montmorillonite (MMT), and debittered kinnow peel powder. The composition of film includes protein isolate (5% w/v), glycerol (50% w/w), peel powder (20% w/w), and MMT (0.5-2.5% w/w). Incorporation of MMT in soybean meal protein-based film loaded with kinnow peel powder showed lesser solubility (16.76-26.32%), and swelling ability (142.77-184.21%) than the film prepared without MMT (29.41%, & 229.41%, respectively). The mechanical properties like tensile strength of nanocomposite film improved from 9.41 to 38.69% with the increasing concentration of MMT. The water vapor transmission rate of the nanocomposite film was decreased by 3.45-17.85% when the MMT concentration increased. Fourier-transform infrared spectroscopy and X-ray diffraction analysis showed no considerable change in the structural properties of the film after the addition of MMT. Differential scanning colorimeter analysis revealed the increment in melting temperature (85.33-92.67 °C) of the film with a higher concentration of MMT. Scanning electron microscopy analysis indicated an increased distributed area of MMT throughout the film at higher concentrations. The antimicrobial activity of the film was remarkably increased by 4.96-17.18% with the addition of MMT. The results obtained in the current work confirmed that MMT incorporation in soybean meal protein-based film can augment its properties and can be utilized for enhancing the storage period of food products.


Subject(s)
Bentonite , Food Packaging , Nanocomposites , Powders , Soybean Proteins , Tensile Strength , Bentonite/chemistry , Nanocomposites/chemistry , Soybean Proteins/chemistry , Food Packaging/methods , Glycine max/chemistry , Solubility , Steam
8.
Sensors (Basel) ; 24(7)2024 Apr 06.
Article in English | MEDLINE | ID: mdl-38610546

ABSTRACT

The study of plant electrophysiology offers promising techniques to track plant health and stress in vivo for both agricultural and environmental monitoring applications. Use of superficial electrodes on the plant body to record surface potentials may provide new phenotyping insights. Bacterial nanocellulose (BNC) is a flexible, optically translucent, and water-vapor-permeable material with low manufacturing costs, making it an ideal substrate for non-invasive and non-destructive plant electrodes. This work presents BNC electrodes with screen-printed carbon (graphite) ink-based conductive traces and pads. It investigates the potential of these electrodes for plant surface electrophysiology measurements in comparison to commercially available standard wet gel and needle electrodes. The electrochemically active surface area and impedance of the BNC electrodes varied based on the annealing temperature and time over the ranges of 50 °C to 90 °C and 5 to 60 min, respectively. The water vapor transfer rate and optical transmittance of the BNC substrate were measured to estimate the level of occlusion caused by these surface electrodes on the plant tissue. The total reduction in chlorophyll content under the electrodes was measured after the electrodes were placed on maize leaves for up to 300 h, showing that the BNC caused only a 16% reduction. Maize leaf transpiration was reduced by only 20% under the BNC electrodes after 72 h compared to a 60% reduction under wet gel electrodes in 48 h. On three different model plants, BNC-carbon ink surface electrodes and standard invasive needle electrodes were shown to have a comparable signal quality, with a correlation coefficient of >0.9, when measuring surface biopotentials induced by acute environmental stressors. These are strong indications of the superior performance of the BNC substrate with screen-printed graphite ink as an electrode material for plant surface biopotential recordings.


Subject(s)
Graphite , Agriculture , Biological Transport , Carbon , Chlorophyll , Steam
9.
Molecules ; 29(7)2024 Mar 30.
Article in English | MEDLINE | ID: mdl-38611838

ABSTRACT

The rhizome of Polygonatum cyrtonema Hua has been used as a traditional Chinese medicine for over 2000 years. The fresh Chinese herb possesses micro toxicity and is thus traditionally alternately steamed and basked nine times to alleviate the toxicity and enhance the pharmaceutical efficacy. Different processing cycles usually result in variable therapeutic effects in the processed Polygonatum cyrtonema Hua (P-PCH). However, it can be hard to tell these various P-PCHs apart at present. To identify the P-PCHs that had undergone repeated steaming one to nine times, the chemical constituents were profiled based on Ultra-Performance Liquid Chromatography with Quadruple-Time-of-Flight Mass Spectrometry, and the Principal Component Analysis and Cluster Analysis methods were adopted to discriminate different cycles of P-PCH. A total of 44 characteristic markers were identified, which allowed the P-PCHs to be discriminated exactly.


Subject(s)
Gastropoda , Polygonatum , Animals , Cluster Analysis , Mass Spectrometry , Steam , Chromatography, Liquid
10.
J Texture Stud ; 55(2): e12830, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38581175

ABSTRACT

Freezing and blanching are essential processing steps in the production of frozen yellow peaches, inevitably leading to texture softening of the fruit. In this study, the synergistic mechanism of stem blanching, freezing conditions (-20°C, -40°C, -80°C, and liquid nitrogen [-173°C]), and sample sizes (cubes, slices, and half peaches) on macroscopic properties of texture, cellular structure, and ice crystal size distribution of frozen yellow peaches were measured. Blanching enhanced the heat and mass transfer rates in the subsequent freezing process. For nonblanched samples, cell membrane integrity was lost at any freezing rate, causing a significant reduction in textural quality. Slow freezing further exacerbated the texture softening, while the ultra-rapid freezing caused structural rupture. For blanched samples, the half peaches softened the most. The water holding capacity and fracture stress were not significantly affected by changes in freezing rate, although the ice crystal size distribution was more susceptible to the freezing rate. Peach cubes that had undergone blanching and rapid freezing (-80°C) experienced 4% less drip loss than nonblanched samples. However, blanching softened yellow peaches more than any freezing conditions. The implementation of uniform and shorter duration blanching, along with rapid freezing, has been proven to be more effective in preserving the texture of frozen yellow peaches. Optimization of the blanching process may be more important than increasing the freezing rate to improve the textural quality of frozen yellow peaches.


Subject(s)
Prunus persica , Steam , Freezing , Food Preservation , Ice
11.
Int J Biol Macromol ; 267(Pt 2): 131553, 2024 May.
Article in English | MEDLINE | ID: mdl-38621569

ABSTRACT

An alternative packaging material based on cellulose that possesses excellent barrier properties and is potentially useful for active packaging has been developed. Cellulose nanofibril was efficiently and selectively oxidized with sodium periodate generating reactive aldehyde groups. These groups formed hemiacetal and hemialdal bonds during film formation and, consequently, highly transparent, elastic and strong films were created even under moisture saturation conditions. The periodate oxidation treatment additionally decreased the polarity of the films and considerably enhanced their water barrier properties. Thus, the water contact angle of films treated for 3 and 6 h was 97° and 102°, their water drop test value was higher than in untreated film (viz., 138 and 141 min with 3 and 6 h of treatment) and their water vapour transmission rate was substantially better (3.31 and 0.78 g m-2 day-1 with 3 and 6 h, respectively). The presence of aldehyde groups facilitated immobilization of the enzyme laccase, which efficiently captures oxygen and prevents food decay as a result. Laccase-containing films oxidized 80 % of Methylene Blue colorant and retained their enzymatic activity after storage for 1 month and 12 reuse cycles, opening the door to the possible creation of a reusable packaging to replace the single-use packaging.


Subject(s)
Cellulose , Food Packaging , Nanofibers , Oxidation-Reduction , Periodic Acid , Cellulose/chemistry , Nanofibers/chemistry , Food Packaging/methods , Periodic Acid/chemistry , Laccase/chemistry , Water/chemistry , Enzymes, Immobilized/chemistry , Steam
12.
Int J Biol Macromol ; 267(Pt 2): 131675, 2024 May.
Article in English | MEDLINE | ID: mdl-38641276

ABSTRACT

The aim of this study is to obtain and characterize starch films structurally modified by in situ precipitation of BaSO4 combined with mechanical activation of casting dispersion in a rotor-stator device. By the rheological method, it was found that the modification causes a decrease in the ability of casting dispersions to structure over time. Composite films with a filler content of 0 %-15 % (w/w) were characterized using optical and SEM microscopy, FT-IR spectroscopy, and tensile and moisture resistance testing data. The maximum increase in strength (by 70 %) and elongation at break (by 870 %) is achieved with a filler content of 5 % and 15 %, respectively. An increase in the filler content to 5 % causes an increase in starch recrystallization rate, but at concentrations above 5 % of BaSO4, it inhibits retrogradation. The films obtained by mechanical activation with optimized parameters were uniformly translucent, had lower water vapor permeability than films made from starch alone, had high flexibility, and did not warp or shrink. The developed high-performance, environmentally friendly method can be recommended for the large-scale production of starch-based composite materials.


Subject(s)
Permeability , Starch , Starch/chemistry , Tensile Strength , Rheology , Spectroscopy, Fourier Transform Infrared , Mechanical Phenomena , Steam
13.
Bioresour Technol ; 400: 130675, 2024 May.
Article in English | MEDLINE | ID: mdl-38608786

ABSTRACT

In this article we can observe the scanning by the literature for the pretreatment of steam explosion applied to lignocellulose biomass. A comparison of the chemical and physical characterization of potato peel as a lignocellulose biomass. Besides, the innovative design of a continuous reactor for the potato peel steam explosion process is shown, with specific temperature and pressure conditions on a pilot scale, detailing its parts. Finally, a finite element analysis was performed where stress results were obtained from the reactor material, severity factor, structural analysis and thermal analysis, providing a panorama of the reactor's behavior with the conditions specific.


Subject(s)
Solanum tuberosum , Steam , Solanum tuberosum/chemistry , Lignin/chemistry , Equipment Design , Temperature , Biomass , Finite Element Analysis , Pressure , Biotechnology/methods , Bioreactors
14.
Bioresour Technol ; 400: 130698, 2024 May.
Article in English | MEDLINE | ID: mdl-38615967

ABSTRACT

The growing textile industry produces large volumes of hazardous wastewater containing dyes, which stresses the need for cheap, efficient adsorbing technologies. This study investigates a novel preprocessing method for producing activated carbons from abundantly available softwood bark. The preprocessing involved a continuous steam explosion preconditioning step, chemical activation with ZnCl2, pyrolysis at 600 and 800 °C, and washing. The activated carbons were subsequently characterized by SEM, XPS, Raman and FTIR prior to evaluation for their effectiveness in adsorbing reactive orange 16 and two synthetic dyehouse effluents. Results showed that the steam-exploded carbon, pyrolyzed at 600 °C, obtained the highest BET specific surface area (1308 m2/g), the best Langmuir maximum adsorption of reactive orange 16 (218 mg g-1) and synthetic dyehouse effluents (>70 % removal) of the tested carbons. Finally, steam explosion preconditioning could open up new and potentially more sustainable process routes for producing functionalized active carbons.


Subject(s)
Azo Compounds , Charcoal , Plant Bark , Steam , Adsorption , Plant Bark/chemistry , Azo Compounds/chemistry , Charcoal/chemistry , Coloring Agents/chemistry , Carbon/chemistry , Spectroscopy, Fourier Transform Infrared , Water Purification/methods , Water Pollutants, Chemical , Wastewater/chemistry , Spectrum Analysis, Raman
15.
Int J Biol Macromol ; 266(Pt 2): 131249, 2024 May.
Article in English | MEDLINE | ID: mdl-38569998

ABSTRACT

This study investigated the development of biodegradable films made from a combination of polyethylene glycol (PEG), carboxymethyl cellulose (CMC) and mixtures from natamycin and ferulic acid. The films were characterized for their surface microstructure, antioxidant activity, thermal stability, mechanical properties, permeability and antifungal/bacterial activity. The addition of natamycin and ferulic acid to the film matrix enhanced antioxidant activity, thermal stability, antimicrobial activity, reduced the water vapor permeability (WVP) to 1.083 × 10-10 g × m-1s-1Pa-1, imparted opaque color and increased opacity up to 3.131 A mm-1. The attendance of natamycin and ferulic acid inside films created a clear roughness shape with agglomerates on the surface of films and caused a clear inhibition zone for Aspergillus niger, E. coli and C. botulinum. The utilization of PG/CMC/N-F packaging material on Ras cheese had a noticeable effect, resulting in a slight decrease in moisture content from 34.23 to 29.17 %. Additionally, it helped maintain the titrable acidity within the range of 0.99 % to 1.11 % and the force required for puncture from 0.035 to 0.052 N with non-significant differences. Importantly, these changes did not significantly affect the sensory qualities of Ras cheese during the storage period.


Subject(s)
Antioxidants , Carboxymethylcellulose Sodium , Coumaric Acids , Food Packaging , Natamycin , Polyethylene Glycols , Antioxidants/pharmacology , Antioxidants/chemistry , Polyethylene Glycols/chemistry , Food Packaging/methods , Carboxymethylcellulose Sodium/chemistry , Coumaric Acids/chemistry , Coumaric Acids/pharmacology , Natamycin/pharmacology , Natamycin/chemistry , Permeability , Biological Availability , Anti-Infective Agents/pharmacology , Anti-Infective Agents/chemistry , Cheese , Steam
16.
Int J Biol Macromol ; 266(Pt 1): 130932, 2024 May.
Article in English | MEDLINE | ID: mdl-38527683

ABSTRACT

The fabrication possibility of nanocomposite film from sweet cherry tree exudate gum (SCG) was studied. To improve SCG film properties, oxidation with hydrogen peroxide, ultraviolet irradiation (UV-A and UV-C), and TiO2 nanoparticles (T-NPs) were used. Hydrogen peroxide oxidation at higher amounts decreased the water vapor permeability (WVP) and thickness and increased the mechanical properties and transparency. In comparison with the UV-A, UV irradiation of the C-type increased permeability, and elongation at break (EAB) and thickness, but reduced the tensile strength (TS), solubility, and transparency. The permeability and tensile strength were increased and elongation at break was decreased at a longer time of irradiation. The transparency values of fabricated films ranged from 65.3 to 79.5 % and WVP were in the range of 2.32-4.72 (×10-10 g/m.s.Pa). The measured TS of the SCG films were between 2.2 and 5 MPa and the EAB of the SCG films was between 35 and 68.7 %. The FTIR spectrum and SEM images revealed that the treatments could affect the bonds and the smoothness of the film surface, respectively. Images provided by AFM showed that the roughness of the films was increased by the addition of T-NPs. The incorporation of T-NPs increased the TS and decreased EAB and WVP. These results indicated that oxidation, UV irradiation and nanomaterials incorporation could be used to improve SCG film properties that are related to food packaging material.


Subject(s)
Hydrogen Peroxide , Nanoparticles , Oxidation-Reduction , Permeability , Plant Gums , Prunus avium , Titanium , Ultraviolet Rays , Titanium/chemistry , Hydrogen Peroxide/chemistry , Nanoparticles/chemistry , Plant Gums/chemistry , Prunus avium/chemistry , Steam , Nanocomposites/chemistry , Tensile Strength , Solubility
17.
J Mech Behav Biomed Mater ; 153: 106507, 2024 May.
Article in English | MEDLINE | ID: mdl-38503082

ABSTRACT

Polyolefins exhibit robust mechanical and chemical properties and can be applied in the medical field, e.g. for the manufacturing of dentures. Despite their wide range of applications, they are rarely used in extrusion-based printing due to their warpage tendency. The aim of this study was to investigate and reduce the warpage of polyolefins compared to commonly used filaments after additive manufacturing (AM) and sterilization using finite element simulation. Three types of filaments were investigated: a medical-grade polypropylene (PP), a glass-fiber reinforced polypropylene (PP-GF), and a biocopolyester (BE) filament, and they were compared to an acrylic resin (AR) for material jetting. Square specimens, standardized samples prone to warpage, and denture bases (n = 10 of each group), as clinically relevant and anatomically shaped reference, were digitized after AM and steam sterilization (134 °C). To determine warpage, the volume underneath the square specimens was calculated, while the deviations of the denture bases from the printing file were measured using root mean square (RMS) values. To reduce the warpage of the PP denture base, a simulation of the printing file based on thermomechanical calculations was performed. Statistical analysis was conducted using the Kruskal-Wallis test, followed by Dunn's test for multiple comparisons. The results showed that PP exhibited the greatest warpage of the square specimens after AM, while PP-GF, BE, and AR showed minimal warpage before sterilization. However, warpage increased for PP-GF, BE and AR during sterilization, whereas PP remained more stable. After AM, denture bases made of PP showed the highest warpage. Through simulation-based optimization, warpage of the PP denture base was successfully reduced by 25%. In contrast to the reference materials, PP demonstrated greater dimensional stability during sterilization, making it a potential alternative for medical applications. Nevertheless, reducing warpage during the cooling process after AM remains necessary, and simulation-based optimization holds promise in addressing this issue.


Subject(s)
Polypropylenes , Steam , Polyenes , Acrylic Resins/chemistry , Sterilization
18.
Int J Med Mushrooms ; 26(4): 73-82, 2024.
Article in English | MEDLINE | ID: mdl-38523451

ABSTRACT

This paper evaluated the effect of different substrate disinfection methods viz. hot water treatment, autoclaving and steam pasteurization at 100°C, 121°C, and 65°C, respectively, on yield of Hypsizygus ulmarius and effects of sun drying, oven drying and cabinet drying techniques at 25 ± 2°C, 40 ± 2°C, and 50 ± 2°C, respectively, on nutritional qualities of H. ulmarius. Hot water treated substrate gave higher yield (215.36 ± 1.49 g) and biological efficiency (71.78%) compared with autoclaved (194.45 ± 3.36 g and 64.81%) and steam pasteurized substrate (194.45 ± 3.36 g and 65.28%). The different drying methods used for drying the fruit bodies significantly influenced the nutrient profile of H. ulmarius. Highest moisture (6.95%), fiber (16.94%) and protein content (22.49%) was retained in sun dried fruit bodies whereas ash content (5.52%) was highest for oven dried fruit bodies. Cabinet dried fruit bodies showed significantly higher percentage of fats (1.82%) and carbohydrates (53.58%). In the DPPH assay the cabinet dried fruit bodies showed the highest antioxidant activity followed by sun dried and oven dried fruit bodies with respective IC50 values as 104.21 ± 0.14, 117.17 ± 0.07 and 163.57 ± 0.02. The drying methods proved to be effective in controlling the bacterial growth for a period of two months after which significant bacterial growth was noted.


Subject(s)
Agaricales , Pleurotus , Steam , Disinfection , Antioxidants/pharmacology
19.
Med Sci Monit ; 30: e942601, 2024 Mar 17.
Article in English | MEDLINE | ID: mdl-38493296

ABSTRACT

BACKGROUND Central sterile supply departments (CSSDs) play a vital role in hospital infection control. We investigate the factors associated with wet pack occurrence after steam sterilization. MATERIAL AND METHODS We designed a log sheet to record information concerning sterilized packs. The data included the type of sterilized pack; outside weather (sunny, overcast, or rainy); the item in the sterilized pack; packaging material; whether the item had been packaged in compliance with guidelines; whether the pack had been laid flat, upright, or leaning at an acute angle; which sterilizer was used for sterilization of the pack; whether the pack had been placed on the top or bottom shelf inside the sterilizer chamber; whether the pack had been loaded in compliance with guidelines; the drying time following sterilization; and cooling time after sterilization. The sterilized packs in our study were selected from all of the packs that were sterilized in the CSSD of the authors' institution during June to December 2021. RESULTS Factors associated with wet pack occurrence after steam sterilization include: outside weather on the day of sterilization; the item in the sterilized pack; packaging material; whether the item had been packaged in compliance with guidelines; whether the pack had been placed on the top or bottom shelf; and cooling time after sterilization. Statistically significant differences (P<0.05) in wet pack incidence were identified for all of these factors. CONCLUSIONS Various factors are associated with wet pack occurrence after steam sterilization. Recommendations for reducing the risk of wet packs include regular maintenance of the steam pipeline, regular replacement of thermal insulation materials for the steam pipeline, and extension of the drying time.


Subject(s)
Steam , Sterilization , Incidence , Sterilization/methods , Hospitals , China/epidemiology
20.
Chemosphere ; 353: 141638, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38442775

ABSTRACT

Condensable particulate matter (CPM) from coal combustion is the focus of current pollutant emission studies, and CPM can be divided into inorganic and organic fractions according to the component characteristics. At present, the effects of different factors in the combustion process on the organic and inorganic components of CPM have not been discussed systematically. Here, we conducted combustion experiments collected the generated CPM on a well-controlled drip tube furnace, and investigated the effects of different factors on the generation of organic and inorganic components of CPM by varying the furnace wall insulation temperature, the ratio of gas supply components and the water vapor content in the flue gas. The results showed that the increase in combustion temperature (1300-1500 °C) and oxygen concentration (15-25%) reduced the total CPM generation by 9.8% and 19.98%, respectively, and the intervention of water vapor increased the ability of the whole CPM sampling device to capture ultrafine condensable particles. The generation of CPM organic components decreased with the enhancement of combustion temperature and oxygen content on combustion characteristics, and alkanes shifted to low carbon content. The amount of CPM inorganic components increased with the increase of water vapor content in the flue gas, and this change was dominated by SO42-. The above results provide a feasible idea for the next step of the precise reduction of CPM components.


Subject(s)
Air Pollutants , Particulate Matter , Particulate Matter/analysis , Air Pollutants/analysis , Coal , Steam , Power Plants , Oxygen
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