Autoclave Method Research Articles

Properties of hydrogel for adsorbent textile dye waste based cellulose-carboxymethyl sago starch

Abstract The use of a single natural polymer in hydrogel preparations is considered insufficient to produce hydrogels that are more durable, more stable, and stronger. Blends of various natural polymers can improve each sago other’s lack of physicochemical characteristics and produce new properties. This research combines two natural polymers, cellulose and starch. Cellulose isolation from Gracilaria verrucosa seaweed using acid hydrolysis and alkaline autoclaving method produced 14.01% cellulose. This study combined the results of cellulose isolation with carboxymethyl sago starch at 0.09; 0.14 and 0.24 mol/mol AGU. The isolated cellulose-carboxymethyl sago starch has the potential as a hydrogel material with the addition of crosslinkers such as epichlorohydrin (ECH). This study aims to synthesize hydrogels from cellulose-carboxymethyl sago starch with application as a textile dye waste absorbent with a concentration of epichlorohydrin (ECH) at 7.5%. Analysis of carboxymethyl sago starch is degrees of substitution, water-soluble index (WSI), and swelling power (SP). The hydrogel properties are characterized by the degree of swelling, degree of polymerization, FTIR, and SEM, and the hydrogel adsorption ability is characterized by adsorption efficiency using a microplate reader. The research results show that hydrogel can be synthesized optimally by adding carboxymethyl sago starch (CMSS) at 0.24 mol/mol AGU. The results of FTIR analysis are also by chemical measurements (swelling and gel fraction). In contrast, for maximum colour absorption, the addition of carboxymethyl sago starch is 0.09 mol/mol AGU for purple, yellow, and black and 0.14 mol/mol AGU for green color absorption. In conclusion, the adsorption ability of hydrogel in commercial textile dyes is maximum when the carboxymethyl sago starch (CMSS) is added at 0.09 mol/mol AGU with the best adsorption efficiency at purple 86.22%, yellow 77.40%, black 73.70% and at the addition of CMSS 0.14 mol/mol AGU the best adsorption efficiency in green is 73.46%.

Comparative Evaluation of the Flexural Strength of Heat-Activated Polymethyl Methacrylate Denture Base Resin With and Without 0.2% by the Weight of Silver Nanoparticles Cured by Conventional and Autoclave Methods: An In Vitro Study.

Heat-activated polymethyl methacrylate (PMMA) is the most common and widely accepted denture base material. Two important drawbacks are the development of denture stomatitis and the high incidence of fracture of denture bases. The present study investigated the effect of adding 0.2% by weight of silver nanoparticles (AgNps) and using the autoclave method of terminal boiling on the flexural strength of heat-activated PMMA denture base resin. A total of 40 samples of heat-activated PMMA blocks were divided into four groups, with 10 samples (n = 10) in each group. Group 1 consisted of unmodified heat-activated PMMA resin (PMMA-1) polymerized by the conventional method of terminal boiling (conventional curing); Group 2 consisted of 0.2% by weight AgNPs added to heat-activated PMMA resin (PMMA-2) polymerized by conventional curing; Group 3 consisted of PMMA-1 polymerized by the autoclave method of terminal boiling (autoclave curing); and Group 4 consisted of PMMA-2 polymerized by autoclave curing. The flexural strength was tested using a universal testing machine. Descriptive statistics were expressed as mean ± SD and median flexural strength. Kruskal-Wallis ANOVA with Mann-Whitney U post hoc test was applied to test for statistical significance between the groups. The level of significance was set at p<0.05. The results showed a statistically significant reduction in flexural strength in Group 2 compared to Group 1. The samples from Group 4 showed a statistically significant increase in flexural strength compared to Group 2. The Group 4 denture base had the highest flexural strength (115.72 ± 7.27 MPa) among the four groups, followed by Group 3 (104.16 ± 4.85 MPa). The Group 1 samples gave a flexural strength of 101.45 ± 3.13 MPa, and Group 2 gave the lowest flexural strength (85.98 ± 3.49 MPa) among the four groups tested. The reduction in flexural strength of the heat-activated PMMA denture base after adding 0.2% by weight of AgNP as an antifungal agent was a major concern among manufacturers of commercially available denture base materials. It was proved in the present study that employing the autoclave curing method of terminal boiling for the polymerization of 0.2% by weight of AgNp-added heat-activated PMMA denture base resulted in a significantly higher flexural strength compared to the conventional curing method of terminal boiling for polymerization. Unmodified heat-activated PMMA gave higher flexural strength values when polymerized by autoclave curing compared to the conventional curing method of terminal boiling.

Experimental investigation of the effect of fabric wrapping method and autoclave curing on the mechanical and thermal degradation of carbon nanotube doped and undoped carbon composite pipes

AbstractAlthough it is seen in the literature that composite pipes are produced by filament winding, there are limited number of studies on the use of fabric wrapping and autoclave. In this study, in order to fill this gap and contribute to the literature and industry, composite pipes were produced using fabric wrapping and autoclave methods together and their mechanical and thermal properties were investigated. The effect of carbon nanotube (CNT) reinforcement on these properties was also investigated. According to low velocity impact (LVI) test, 10%–25% impact strength increase was observed with CNT reinforcement. Thermogravimetric analysis (TGA) shows that mass loss decreased by ⁓10% and the degree of thermal degradation increased by ⁓10%. In dynamic mechanical analysis (DMA), it is observed that epoxy glass transition temperature (Tg) increased by 11% with CNT reinforcement. At the end of the study, the mechanical and thermal properties of the pipes produced by autoclave and fabric wrapping methods were improved compared to the literature and contributed to science and therefore to the increased use of prepreg carbon pipes in the industry.Highlights Composite carbon pipes were produced by applying prepreg fabric wrapping and autoclave curing methods together. The mechanical and thermal properties of multi‐walled carbon nanotube (MWCNT) reinforced and unreinforced carbon composite pipes were investigated. According to TGA, it was observed that the mass loss decreased. Thermal decomposition temperature increased for MWCNT reinforced and unreinforced samples. According to DMA, Tg of epoxy decreased for MWCNT unreinforced sample and increased for MWCNT reinforced sample.

Влияние минерализатора и продолжительности синтеза на сорбционные свойства ситинакита и иванюкита

Titanosilicates with the structure of sitinakite and ivanyukite were synthesized with the use of enrichment wastes of quartz-leucoxene concentrate (Yarega deposit, Komi Republic) by autoclave method. It was found that using a mixture of mineralizer KOH and NaOH at a concentration of 0.15 and 1 mol/l, K-Na sitinakite was formed. Increasing the concentration of KOH to 0.45 mol/L and decreasing NaOH to 0.7 mol/L led to crystallization of ivanyukite. The obtained titanosilicates are characterized by high sorption activity towards Sr2+ and Cs+ cations. Sorption capacity of K-Na sitinakite and ivanyukite for Sr2+ was 95–110 and 102–114 mg/g, respectively. The Cs+ sorption capacity for K-Na sitinakite is 240 mg/g, the sorption capacity for ivanyukite is much higher — 370–380 mg/g. It was shown that the differences in the sorption capacity of K-Na sitinakite and ivanyukite are caused by the features of the crystal structure.

Production of novel Zr–Mg nanoceramics based on kaolinite clay with strong antibacterial activity

Gram-negative bacteria Pseudomonas putida, Gram-positive Bacillus subtilis, and Staphylococcus aureus were utilized as test samples to evaluate the antibacterial characteristics of DD3-clay/MgO and DD3+38 wt% ZrO2-clay/MgO nanoparticles. The ceramic powders prepared by a thermal autoclave method are characterized before and after Mg addition by SEM, EDX, XRD, IR, UV–visible, and TEM in order to investigate microstructure, phase, and surface morphology. The results showed that after adding Mg, it led to the deformation of the crystal lattices of (mullite, zirconium silicate, and zirconium oxide) together with a decrease in particle size (75–103 nm) and a complete change in its shape from nanotube to nanospherical, as observed by SEM and TEM analyses. It also confirmed by UV–visible spectroscopy that the addition of Mg increases the absorbance accompanying a decrease in the energy gap of 1.91, 1.74, 1.73, and 1.43 eV corresponding to DD3, DD3Z, DD3/30 wt% Mg and DD3Z/30 wt% Mg respectively. The antibacterial mechanism is related to the size of the particles, the solvent used for powder dissolution, the nanoparticle's size when they come into touch with bacteria, and the generation of reactive oxygen species (ROS: ˙O2−, ˙OH, and H2O2). It was observed that the anti-bacterial activity is enhanced with 10 wt% and 30 wt% of Mg added to a modified ceramic powder. Also, more O2− is formed on the surface of the prepared powder, which penetrates the bacterial cell and destroys it. The nanocomposite particles showed remarkable antibacterial activity when they were dissolved in DMSO compared to methanol and chloroform as organic solvents. The aim is to enrich knowledge on the antibacterial activities of metal nanoparticles (ZrSiO4 and MgO) on three bacterial strains with different Grams due to their extensive involvement in the phenomena of contamination and infection encountered in the medical field. The synthesized nanoparticles have good antimicrobial activity against all strains tested. A maximum inhibition zone of 35 ± 0.2 mm was obtained with S. aureus, a zone of 23 ± 0.46 mm with P. putida and a zone of 27 ± 0.46 nm with B. subtilis for DD3/30 wt% Mg and an inhibition zone of 38 ± 0.93 mm, 26 ± 0.24 nm and 17 ± 0.33 nm was obtained with same strains for DD3Z/30 wt% Mg, respectively.

Stability and Failure of Thin-Walled Composite Plate Elements with Asymmetric Configurations.

In the present study, the stability and failure phenomena of thin-walled constructions subjected to axial compression, featuring a central cut-out, and constructed from composite materials were explored. These constructions were fabricated from a carbon-epoxy composite using the autoclave method. The research encompassed experimental assessments on actual specimens alongside numerical analyses employing the finite element approach within the ABAQUS® software. The investigation spanned the entire load spectrum up to the point of structural failure, incorporating both practical trials and simulation analysis. During the practical assessments, the study monitored the post-buckling response and captured acoustic emissions to thoroughly evaluate the composite's failure mechanisms. Additionally, the ARAMIS system's non-invasive three-dimensional scanning was employed to assess deformations. Theoretical simulations utilized a step-by-step failure analysis, initiating with failure onset as per Hashin's theory and proceeding to failure progression based on an energy criterion. The simulation outcomes, particularly concerning the critical and post-critical phases, were juxtaposed with empirical data to identify the composite's vulnerability zones. The comparison underscored a significant concordance between the simulation predictions and the empirical findings.

Three accelerated methods based on microwave, hydrothermal and conventional heating in the green synthesis of selenium nanoparticles using garlic aqueous extract: Screening and characterization

Selenium nanoparticles (Se NPs) have unique biological characteristics, including anticancer, antioxidant and antimicrobial activities. Furthermore, the green synthesis of Se NPs using plant extracts, due to their natural reductant and stabilizer molecules, can intensify the process with minimal toxic effects on the human body and the environment. Se NPs have been synthesized using an aqueous extract of garlic and three accelerated heating methods based on microwave (800 W for 2.5 min), hydrothermal (temperature and pressure of 121 ºC and 1.5 atm, for 15 min) and conventional (at 150 ºC for 1 h) heating using a heater with stirring. Solution mixtures containing 20 mL of the prepared extract and 5 mL of sodium selenite solution (10 mM) were exposed to these three mentioned heating methods. Fourier transform infrared spectroscopy, UV-Vis spectrophotometry, dynamic light scattering analysis and transmission electron microscopy were used to assess characteristics of the formed Se NPs. The results showed that the fabricated Se NPs via microwave, autoclave and conventional heating methods had minimum particle size (107 nm) and polydispersity index (0.155), and maximum zeta potential (-38.7 mV) values. Furthermore, the spherical formed Se NPs using garlic extract and under microwave, conventional and autoclave heating methods had antioxidant activity of 44.2, 34.8 and 32.6 %, respectively. The formed Se NPs also indicated high antibacterial activity toward Escherichia coli and Staphylococcus aureus bacteria strains.

Rice starch modification by thermal treatments with avocado oil: Autoclave versus microwave methods

This study aimed to evaluate the physical and chemical alterations in rice starch modified by heat-moisture treatment (HMT) using an autoclave and a microwave, in association with avocado oil (AO), and evaluate the effects on thermal and structural properties, in vitro digestibility, and estimated glycemic index (eGI). Samples were adjusted to 30 % (w/w) moisture and 2, 4 and 8 % AO. HMT was conducted at 110 °C for 1 h in the autoclave (A0%, A2%, A4%, and A8%) and at 50 °C for 3 min in the microwave (M0%, M2%, M4%, and M8%). Both procedures did not alter the starch crystallinity pattern (type-A). Pasting viscosity, setback, relative crystallinity, and gelatinisation enthalpy decreased as the AO content increased in both HMT processes. The M8% showed reduced digestibility, decreased eGI (72.99, p < 0.05), and lower starch hydrolysis concentration (62.75 %, p < 0.05). The application of HMT with the addition of AO may be an interesting process for obtaining resistant starch since its content increased after both treatments (A8%, M4%, and M8%). The microwave process proved efficient, making it possible to use a lower temperature, less time, and less energy for modification and obtain starches with improved characteristics.

Green synthesis of rice straw-derived silica nanoparticles by hydrothermal process for antimicrobial properties and effective degradation of dyes

Rice straw is considered a major agricultural waste that has become a major threat to the environment. However, waste valorization of rice straws is a major challenge for the whole world. Therefore, this research aimed to utilize the different varieties of rice straw including Parmal rice straw (PRS), and Basmati rice straw (BRS) for the synthesis of silica nanoparticles (SiNPs) using hydrothermal autoclave method to precisely modify the particle size, and distribution, morphology and purity. This method uses water as a reaction medium under high temperature and pressure, which results in energy savings and reduced chemical waste compared to traditional methods. Furthermore, SiNPs were characterized using different analytical techniques. SEM showed the rough, compact, and highly ordered surface for both samples, while the SNP exhibited irregular shapes and rough surfaces. Rice straw powder revealed major functional groups at 787 cm−1, 1461 cm−1, and 2919.10 cm−1. BRS and PRS showed thermal stability up to 380 ℃ and 250 ℃, respectively. The particle size of BRS and PRS were found to be 112.47±1.23 nm and 114.98±1.23 nm, respectively. PRS-SiNPs showed the effective dye reduction ability for anthraquinone (96.79%± 0.39) and alizarin yellow (92.63%± 0.17) in 30 min. Additionally, the SiNPs exhibited potential bactericidal activity against Staphylococcus aureus and Escherichia coli in terms of zone of inhibition. Overall, the SiNPs synthesized from PRS demonstrated superior photocatalytic efficiency in the reduction of dyes compared to those synthesized from BRS.

Investigation of the effect of thermal aging and wear test parameters on the wear behavior of glass fiber (GF) reinforced epoxy composites

AbstractThis study focused on the wear behavior of unidirectional, thick GF epoxy composites produced using the autoclave method. The thermal aging process was applied for 250 and 500 cycles to understand the wear behavior of the material as it ages over time. To evaluate the wear behavior of the samples, wear tests were carried out under three different loads (10, 20, and 30 N) and three different sliding distances (150, 300, and 450 m). Taguchi‐based regression analysis was used to analyze the experimental results. The results obtained were evaluated using ANOVA tables and main and contour graphs. When the test results are examined, it is surprisingly observed that the wear resistance of the composite material increases positively with the aging effect. With thermally aging while the coefficient of friction value of composite samples increases from approximately 0.12 to 0.3, the wear volume decreases from approximately 4 to 1.3 mm3. Taguchi based regression analysis showed that the relationship between wear and thermal cycle sliding distance and load can be established by reducing the number of experiments in wear studies.Highlights Thermal aging effect on wear properties of thick GFRP was determined. Minimum wear volume and COF values were determined by applying ANOVA. It was determined that a load increment has the most impact on wear volume. Worn surface images supported the reduction in the wear rates of the thick GFRP. Empirical regression models developed for the mathematical prediction.

Autoclave-mediated reduction of graphene oxide for enhanced conductive films

A highly efficient and environmentally friendly method for producing high-quality reduced graphene oxide (rGO) films is explored. It consists of a scalable autoclave process devoid of hazardous reductants. In detail, the reduction of four distinct graphene oxide materials, whose O/C ratio varied from 0.28 to 0.58, through an autoclave-mediated hydrothermal process at 200 °C and 12 bars pressure is carried out. This employs overheated steam as a heat carrier, without any additional solvents or reducing agents. Upon mild annealing (80 °C), the final rGO films result being robust, self-supporting, and electrically conductive. This study investigates the impact of both the initial GO’s oxidation degree and the volume distribution on the efficacy of the hydrothermal process in synthesizing rGO systems. Furthermore, a comparison between films, created through both hydrothermal autoclave-mediated and thermal oven-mediated methods, is conducted, by assessing their electrical, morphological, chemical, and structural properties. Films produced via the autoclave method display notably improved electrical surface resistivity (3.34·102 Ω/sq) compared to the traditional thermal treatments (6.71·105 Ω/sq). These promising results emphasize the potential of this eco-friendly route as a foundation for scalable and sustainable fabrication of valuable graphene-based conductive materials.

The Optimization of Vacuum-Bagging Processing in Oven Cure for Tensile Strength in Composite Laminate

The implementation of autoclaves has been limited due to high production costs and an excess of residual stress. These drawbacks have led to the exploration and development of an alternative method known as out-of-autoclave (OoA) manufacturing process. This research study was proposed to enhance the production of high tensile strength in composite laminate by optimizing the vacuum-bagging-only (VBO) pre-forming process. The impacts of both individual and combined pre-forming parameters in VBO-oven cure processing were measured for traditional low-cost glass/epoxy composite material with respect to the tensile strength of the cured laminates. Twenty composite panels were produced according to specified parameter combinations using central composite design in a fractional factorial approach for creating a response surface model. The study examined three variables, namely the duration of vacuum debulking, the number of sides with edge breather, and the weight of the intensifier. Two laminates were manufactured without additional processing parameters using both the oven (baseline) and autoclave methods for validation purpose. Subsequently, a tensile test was carried out following ASTM D 3039. The interaction among the combined parameters was examined using analysis of variance (ANOVA). The laminates exhibited the lowest tensile strength when the intensifier was not present, while the highest tensile strength was recorded when edge breather, debulk, and intensifier were applied at varying levels. An ideal processing configuration of 30 minute-debulk, each side of edge breather and 1kg-intensifier had resulted in the production of laminate with the highest tensile strength, measuring 407.44 MPa. This value was roughly 17.2% higher than that of the baseline laminate and 3.77% higher than the autoclave laminate.

Synthesis of Two-Dimensional (Cu-S)n Metal-Organic Framework Nanosheets Applied as Peroxidase Mimics for Detection of Glutathione.

Facilely synthesized peroxidase-like nanozymes with high catalytic activity and stability may serve as effective biocatalysts. The present study synthesizes peroxidase-like nanozymes with multinuclear active sites using two-dimensional (2D) metal-organic framework (MOF) nanosheets and evaluates them for their practical applications. A simple method involving a one-pot bottom-up reflux reaction is developed for the mass synthesis of (Cu-S)n MOF 2D nanosheets, significantly increasing production quantity and reducing reaction time compared to traditional autoclave methods. The (Cu-S)n MOF 2D nanosheets with the unique coordination of Cu(I) stabilized in Cu-based MOFs demonstrate impressive activity in mimicking natural peroxidase. The active sites of the peroxidase-like activity of (Cu-S)n MOF 2D nanosheets were predominantly verified as Cu(I) rather than Cu(II) of other Cu-based MOFs. The cost-effective and long-term stability of (Cu-S)n MOF 2D nanosheets make them suitable for practical applications. Furthermore, the inhibition of the peroxidase-like activity of (Cu-S)n MOF nanosheets by glutathione (GSH) could provide a simple strategy for colorimetric detection of GSH against other amino acids. This work remarkably extends the utilization of (Cu-S)n MOF 2D nanosheets in biosensing, revealing the potential for 2D (Cu-S)n MOFs.

Impact of Deposition Temperature on Physical Properties of MgO-SiO2 Preparer Based on Natural Resources (Rocks)

This search displays the effects of deposition temperature on the physical properties of MgO-SiO2 thin films. These thin films were deposited on glass substrates using the autoclave method (within 120min) and at temperature deposition range of within a deposition temperature range of 150 °C–300 °C. These films were diagnosed using X-ray diffraction (XRD) and scanning electronic microscopy (SEM) and UV–Vis spectrophotometer for structural, morphological and optical analysis respectively. Using energy dispersive spectroscopy (EDX), the compositional characterization analysis of the MgO-SiO2 films was also carried out. The XRD patterns reveal that the MgO-SiO2 films have a cubic and hexagonal phase polycrystalline composition with the preferential growth direction of (0 0 2) and (0 1 1) respectively. Granular size was found to decrease by increasing the deposition temperature except at 200 °C, The crystal and optical parameters are calculated and discussed in detail. Membranes were found to have an absorption coefficient below (104 Cm−1) which means indirect permissible and forbidden electronic transitions. The SEM observations show that the films have homogeneous surfaces with clear fullness, The experimental results reveal that MgO-SiO2 thin films may be used as an alternative material for environmentally friendly buffer layer.

Silk wastes and autoclaved degumming as an alternative for a sustainable silk process

Silk degumming is considered the first point in the preparation of silk-based materials since this process could modify the silk fiber and the properties of its related products. This study evaluated the differences in morphology, secondary structure, amino acid content, thermal stability, and mechanical properties of two types of raw materials, defective cocoons (DC) and silk fibrous waste (SW), degummed by chemical (C) and autoclaving (A) methods. Subsequently, silk fibroin films were prepared by dissolving each type of degummed fibers, and thermal and structural films properties were determined. The findings demonstrated that autoclaving is an efficient alternative to remove silk sericin, as the resulting fibers presented improved structural, thermal, and mechanical properties compared to those obtained by the chemical method. For films preparation, autoclave resulted in a good option, but dissolution parameters need to be adjusted for defective cocoons. Furthermore, similarities between the physicochemical properties of fibers and films from both fibrous wastes suggest that SW is a promising raw material for producing fibrous resources and regenerated silk fibroin materials. Overall, these findings suggest new recycling methods for fibrous waste and by-products generated in the silk textile production process.

EXAMINATION OF COMPOSITE DISC SPRINGS

This study aims to produce composite disc springs from carbon prepreg material, which is close to the characteristic curve of the steel disc spring or better than steel, which constitutes a group of machine elements. In this way, the design will be lightened without significantly diverging from the force/deformation ratio of the disc spring. For this, first of all, a standard steel disc spring was selected, and its characteris-tic curve was determined by the finite element analysis method. For the composite disc springs to be pro-duced, the selected steel disc spring geometry was taken as reference, and different cone heights (taper angles) and different orientation angles of the carbon prepreg layers were determined as variable parame-ters. For all these parameters, finite element analyses were made for the carbon prepreg material in the ANSYS Workbench module, and the disc springs de-signed using these analyses were produced by the autoclave method in a closed mold and tested. As a result of compression tests, spring characteristics of steel and composite disc springs were obtained and compared. The results reveal that composite disc springs produced in certain parameters have more suitable characteristics than steel disc springs.

Port site tuberculosis: is an epidemic on shore?

Background: Bangladesh has to carry an extensive burden of tuberculosis in varied form of presentation. In the era of minimally invasive surgery (MIS) port site tuberculosis is usually a rare incidence. Among all the infections it has been identified as a prolong burden for both patients and surgeons. This study was done to notify such rare complication of MIS and tried to find out is there really an upsurge of this infection in Bangladesh. Methods: This retrospective study was done an urban area of Bangladesh during September 2020 to June 2021. 483 laparoscopic surgeries were done by six different surgeons in 5 different hospitals during September 2020 to January 2021. All surgeons have minimum five years experiences in laparoscopic surgery. 20 minutes emersion of the laparoscopic instruments into activated glutaraldehyde solution 2% (CIDEX) was used as method of chemical sterilization. Other surgical instruments were sterilized by conventional autoclave method. Results: Among them 87 patients developed port infections. 66 (75.86%) patients of this 87 developed non-healing ulcer. Biopsy from the ulcer showed granulomatous tissue in 56 patients and the other 10 was nonspecific inflammation. CAT I anti-TB chemotherapy was initiated to all the patients and all improved by this therapy. Use of 3.54% glutaraldehyde instead of 2% or immersion of instruments for a longer period (more than 20 minutes) could be tried in larger scale to prove its efficacy. Conclusions: National tuberculosis control program (NTP) should give more emphasis on cutaneous tuberculosis as the morbidity of this disease is high. Surgeons of Bangladesh should admit and report such incidences as, if it is documented in other areas of the country, it may need to develop a national guideline to prevent and treat port site tuberculosis.

Vertical Occlusal Dimension Changes of Complete Dentures between Autoclave and Traditional Processing Techniques

The aim of the present in vitro study was to investigate the effect of using an autoclave with three different programs and the traditional water bath method (short cycle) on the changes in the vertical occlusal dimension of the complete acrylic dentures. Forty complete acrylic dentures were divided into four groups: G1, dentures were polymerized by water bath method (short cycle for 90 min at 74 °C and then 30 min at 100 °C); G2, dentures were polymerized with an autoclave (134 °C/2.1 bar/10 min); G3, dentures were polymerized with an autoclave (121 °C/1.1 bar/20 min); and G4, dentures were polymerized with an autoclave (121 °C/1.1 bar/5 min). The vertical occlusal dimension of the dentures was measured before and after the polymerization process. The difference between the initial and final measurements expressed the change in the vertical occlusal dimension. Data were statistically analyzed by t-test and one-way ANOVA test. Statistically significant lower vertical dimension changes were detected in G1 (0.703 ± 0.078 mm) compared to the other groups (p &lt; 0.05), whilst statistically greater changes were detected in G4 (1.263 ± 0.063 mm) compared to the other groups. No statistically significant differences were found between G2 (0.844 ± 0.061 mm) and G3 (0.88 ± 0.059 mm) (p &gt; 0.05). Within the limitations of the present in vitro study, it can be concluded that all polymerization methods increase the vertical occlusal dimension of complete acrylic dentures. The increase in the vertical occlusal dimension in Groups 1, 2 and 3 was less than 1 mm which is clinically acceptable and can be overcome by selective abrasion. Therefore, the traditional curing technique using a water bath and the autoclave methods using two settings (134 °C/2.1 bar/10 min or 121 °C/1.1 bar/20 min) could be used for the complete acrylic denture with acceptable augmentation in the vertical occlusal dimension. In contrast, the method used in G4 increases the vertical occlusal dimension by more than 1 mm, which is not clinically acceptable.

Silk Sericin and its Food application: A Review

This review deals with the structural and functional properties of sericin and its application in the food industry to enhance the food preservation. Sericin is a globular protein that contains silk fibre from the bombyx mori silkworm case. It has 18 amino acids. The proteins had been utilized in space travel food. Sericin is hydrophilic in nature and shows a physiological impact on the gastrointestinal system. Sericin contains different microbiology properties which allow us to apply it to different fields. Sericin can be attributed to three structures such as sericin A, sericin B, and sericin C. Comparison of extraction methods, extraction with steam using autoclave method is more sustainable. Sericin joins with properties such a gelling property, sol-gel change, isoelectric pH, dissolvability of sericin, and sun–nuclear weight. Sericin inhibits the growth of microorganisms such as S.aureus as gram-positive microorganisms and E.coli as gram-negative microorganisms. It provides a major antioxidant property by inhibiting tyrosinase enzymes. Sericin is an intriguing contender to impede the browning impact in food items without the expansion of manufactured cell antioxidant compounds. Food products prepared with sericin helps in diabetics and keeping up with the diet. The utilization of edible coating or films using sericin not only imparts antibrowning, antimicrobial, and antioxidant properties but also improves the nutritional properties of the food product. Though the production rate of sericin is high in India, a very few attempts have been made to utilize sericin in food applications. Hence utilizing sericin in food applications provide several advantages and improves its scope in food industry.

Assessment of binding interaction to salmon sperm DNA of two antiviral agents and ecofriendly nanoparticles: comprehensive spectroscopic study

The direct binding of antiviral agents; Daclatasvir and valacyclovir and green synthesized nanoparticles to salmon sperm DNA have been assessed in a comparative study. The nanoparticles were synthesized by the hydrothermal autoclave method and have been fully characterized. The interactive behavior and competitive binding of the analytes to DNA in addition to the thermodynamic properties were deeply investigated by the UV–visible spectroscopy. The binding constants were monitored in the physiological pH conditions to be 1.65 × 106, 4.92 × 105 and 3.12 × 105 for daclatasvir,valacyclovir and quantum dots, respectively. The significant changes in the spectral features of all analytes have proven intercalative binding. The competitive study has confirmed that, daclatasvir, valacyclovir, and the quantum dots have exhibited groove binding. All analytes have shown good entropy and enthalpy values indicating stable interactions. The electrostatic and non-electrostatic kinetic parameters have been determined through studying the binding interactions at different concentrations of KCl solutions. A molecular modelling study has been applied to demonstrate the binding interactions and their mechanisms. The obtained results were complementary and afforded new eras for the therapeutic applications.