Design and preparation of a novel pullulan hard capsule formulation: A promising green candidate and study of crucial capsule features.

Plant-based hard capsules have gained considerable attention because of their great properties. Accordingly, designing and developing of these kinds of capsules will be a difficult task. Herein, an innovative pullulan-based hard capsule formulation was prepared for the first time. A series of characterization approaches, including Fourier transform infrared, field emission scanning electron microscope, and rheology analysis, were utilized to figure out the straightforward preparation of a designed hard capsule. Many tests and experiments were performed to achieve the optimum capsule formulation. Based on the obtained results, specifications such as uniform downfall and non-desirable adhesion, and other ideal characteristics of the capsule display the critical function. The gelling promoter of divalent cationic salts is more beneficial than its single-valent counterparts. With respect to the key role of gelling promoter, the presence of chosen MgSO4.7H2O salt and the source of selected carrageenan are important parameters to achieve optimal formulation. Moreover, field emission scanning electron microscope images illustrate that the weight ratio of 3.5 (gelling agent to salt) displays uniform surface morphology without any impurities or other foreign materials. Likewise, the outcomes of the rheology test also illustrated that the weight ratio of 3.5 is preferable. Considering the different weight ratios, the benefits of a weight ratio of 3.5 outweigh the other investigated ratios. Overall, the current research addresses substantial information about developing pullulan-based hard capsules for target usage.

Identification and In Silico Characterization of a Conserved Peptide on Influenza Hemagglutinin Protein: A New Potential Antigen for Universal Influenza Vaccine Development.

Antigenic changes in surface proteins of the influenza virus may cause the emergence of new variants that necessitate the reformulation of influenza vaccines every year. Universal influenza vaccine that relies on conserved regions can potentially be effective against all strains regardless of any antigenic changes and as a result, it can bring enormous public health impact and economic benefit worldwide. Here, a conserved peptide (HA288-107) on the stalk domain of hemagglutinin glycoprotein is identified among highly pathogenic influenza viruses. Five top-ranked B-cell and twelve T-cell epitopes were recognized by epitope mapping approaches and the corresponding Human Leukocyte Antigen alleles to T-cell epitopes showed high population coverage (>99%) worldwide. Moreover, molecular docking analysis indicated that VLMENERTL and WTYNAELLV epitopes have high binding affinity to the antigen-binding groove of the HLA-A*02:01 and HLA-A*68:02 molecules, respectively. Theoretical physicochemical properties of the peptide were assessed to ensure its thermostability and hydrophilicity. The results suggest that the HA288-107 peptide can be a promising antigen for universal influenza vaccine design. However, in vitro and in vivo analyses are needed to support and evaluate the effectiveness of the peptide as an immunogen for vaccine development.

A Study on Machine Learning Methods' Application for Dye Adsorption Prediction onto Agricultural Waste Activated Carbon.

The adsorption of dyes using 39 adsorbents (16 kinds of agro-wastes) were modeled using random forest (RF), decision tree (DT), and gradient boosting (GB) models based on 350 sets of adsorption experimental data. In addition, the correlation between variables and their importance was applied. After comprehensive feature selection analysis, five important variables were selected from nine variables. The RF with the highest accuracy (R2 = 0.9) was selected as the best model for prediction of adsorption capacity of agro-waste using the five selected variables. The results suggested that agro-waste characteristics (pore volume, surface area, agro-waste pH, and particle size) accounted for 50.7% contribution for adsorption efficiency. The pore volume and surface area are the most important influencing variables among the agro-waste characteristics, while the role of particle size was inconspicuous. The accurate ability of the developed models' prediction could significantly reduce experimental screening efforts, such as predicting the dye removal efficiency of agro-waste activated carbon according to agro-waste characteristics. The relative importance of variables could provide a right direction for better treatments of dyes in the real wastewater.

Electromagnetic Characterization of a Multiwalled Carbon Nanotubes-Silver Nanoparticles-Reinforced Polyvinyl Alcohol Hybrid Nanocomposite in X-Band Frequency.

This study presents the electromagnetic (EM) characterization of a multiwalled carbon nanotubes (MWCNT)-silver nanoparticles (AgNP)-reinforced poly(vinyl alcohol) (PVA) hybrid nanocomposite fabricated via the solution mixing technique. Primarily, the structure and morphological properties of the PVA/MWCNT-AgNP hybrid nanocomposite are confirmed by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The complex permittivity (ε*) and permeability (µ*), as well as the electromagnetic scattering parameters are measured using a PNA network analyzer equipped with X-band waveguide. The results showed an enhanced permittivity (ε' ≈ 25) value of the hybrid nanocomposite in the frequency range of 8-12 GHz. However, the permeability decreased to almost zero (µ' ≈ 0.4) since the inclusion of AgNP with an average particle size of 40 nm is not susceptible to magnetization and causes higher magnetic losses (tan δµ) than dielectric losses (tan δε). Remarkably, the hybrid nanocomposite reduced transmission of electromagnetic (EM) wave by nearly 60% in comparison to PVA/MWCNT. This is attributed to the enhanced absorption and reflection at the nanotubes, and metal-dielectric interfaces have induced multiple internal reflections owing to the porous structure of the nanocomposite. The prospect of the PVA/MWCNT-AgNP hybrid nanocomposite is favorable as a thin absorbing material for EM shielding applications.

Methylene Blue Dye Photocatalytic Degradation over Synthesised Fe3O4/AC/TiO2 Nano-Catalyst: Degradation and Reusability Studies.

In this study, activated carbon (AC) from coconut shell, as a widely available agricultural waste, was synthesised in a simple one-step procedure and used to produce a magnetic Fe3O4/AC/TiO2 nano-catalyst for the degradation of methylene blue (MB) dye under UV light. Scanning electron microscopy revealed that TiO2 nanoparticles, with an average particle size of 45 to 62 nm, covered the surface of the AC porous structure without a reunion of its structure, which according to the TGA results enhanced the stability of the photocatalyst at high temperatures. The photocatalytic activities of synthesised AC, commercial TiO2, Fe3O4/AC, and Fe3O4/AC/TiO2 were compared, with Fe3O4/AC/TiO2 (1:2) exhibiting the highest catalytic activity (98%). Furthermore, evaluation of the recovery and reusability of the photocatalysts after treatment revealed that seven treatment cycles were possible without a significant reduction in the removal efficiency.

Application of Efficient Magnetic Particles and Activated Carbon for Dye Removal from Wastewater.

Since the turn of the 21st century, water pollution has been a major issue, and most of the pollution is generated by dyes. Adsorption is one of the most commonly used dye-removal methods from aqueous solution. Magnetic-particle integration in the water-treatment industry is gaining considerable attention because of its outstanding physical and chemical properties. Magnetic-particle adsorption technology shows promising and effective outcomes for wastewater treatment owing to the presence of magnetic material in the adsorbents that can facilitate separation through the application of an external magnetic field. Meanwhile, the introduction of activated carbon (AC) derived from various materials into a magnetic material can lead to efficient organic-dye removal. Therefore, this combination can provide an economical, efficient, and environmentally friendly water-purification process. Although activated carbon from low-cost and abundant materials has considerable potential in the water-treatment industry, the widespread applications of adsorption technology are limited by adsorbent recovery and separation after treatment. This work specifically and comprehensively describes the use of a combination of a magnetic material and an activated carbon material for dye adsorption in wastewater treatment. The literature survey in this mini-review provides evidence of the potential use of these magnetic adsorbents, as well as their magnetic separation and recovery. Future directions and challenges of magnetic activated carbon in wastewater treatment are also discussed in this paper.

Comprehensive review on nanocellulose: Recent developments, challenges and future prospects.

Cellulose constitutes most of a plant's cell wall, and it is the most abundant renewable polymer source on our planet. Given the hierarchical structure of cellulose, nanocellulose has gained considerable attention as a nano-reinforcement for polymer matrices in various industries (medical and healthcare, oil and gas, packaging, paper and board, composites, printed and flexible electronics, textiles, filtration, rheology modifiers, 3D printing, aerogels and coating films). Herein, nanocellulose is considered as a sustainable nanomaterial due to its substantial strength, low density, excellent mechanical performance and biocompatibility. Indeed, nanocellulose exists in several forms, including bacterial cellulose, nanocrystalline cellulose and nanofibrillated cellulose, which results in biodegradable and environmentally friendly bionanocomposites with remarkably improved material properties. This paper reviews the recent advances in production, physicochemical properties, and structural characterization of nanocelluloses. It also summarises recent developments in several multifunctional applications of nanocellulose with an emphasis on bionanocomposite properties. Besides, various challenges associated with commercialisation and economic aspects of nanocellulose for current and future markets are also discussed inclusively.

An improved physico-mechanical performance of macropores membrane made from synthesized cellulose carbamate.

Under hydrothermal condition, kenaf cellulose carbamate (KCC) was synthesized using urea and kenaf core pulp (KCP) without catalyst and organic solvent. The KCC was prepared with various urea/KCP ratios (2:1, to 4:1 and 6:1) with the aid of autoclave and oil bath, whereas the regenerated KCC membranes were formed via solution casting method. The physical and thermal properties of KCC were studied. The urea/KCP ratio used in preparing KCC corresponds with the nitrogen percentage obtained in KCC. The formation of the regenerated KCC membranes could be confirmed by the existence of cellulose II through X-ray diffraction (XRD) study. As examined by Field emission scanning electron microscope (FESEM), the regenerated KCC membranes possessed the greater pore size structures at higher urea concentration. Mechanical results showed the tensile strength and modulus of regenerated KCC membranes have improved up to 43.4% and 76.9%, respectively, as compared to native KCP membrane. It can be concluded from the findings that synthesizing KCC and its membranes with improved mechanical properties has broad prospects for potential industrial applications such as biomembranes and packaging materials.

Optimization of Bi2O3, TiO2, and Sb2O3 doped ZnO-based low-voltage varistor ceramic to maximize nonlinear electrical properties.

In ZnO-based low voltage varistor, the two essential features of microstructure determining its nonlinear response are the formation Bi-enriched active grain boundaries as well as a controlled ZnO grain size by secondary spinel-type phases. Besides, the microstructure and phase composition are strongly affected by the dopant concentration during sintering process. In this study, the optimal dopant levels of Bi2O3, TiO2, and Sb2O3 to achieve maximized nonlinear electrical property (alpha) were quantified by the response surface methodology (RSM). RSM was also used to understand the significance and interaction of the factors affecting the response. Variables were determined as the molar ratio of Bi2O3, TiO2, and Sb2O3. The alpha was chosen as response in the study. The 5-level-3-factor central composite design, with 20 runs, was used to conduct the experiments by ball milling method. A quadratic model was established as a functional relationship between three independent variables and alpha. According to the results, the optimum values of Bi2O3, TiO2, and Sb2O3 were obtained 0.52, 0.50, and 0.30, respectively. Under optimal conditions the predicted alpha (9.47) was calculated using optimal coded values from the model and the theoretical value is in good agreement with the value (9.43) obtained by confirmation experiment.

Optimizing Bi2O3 and TiO2 to achieve the maximum non-linear electrical property of ZnO low voltage varistor.

BACKGROUND: In fabrication of ZnO-based low voltage varistor, Bi2O3 and TiO2 have been used as former and grain growth enhancer factors respectively. Therefore, the molar ratio of the factors is quit important in the fabrication. In this paper, modeling and optimization of Bi2O3 and TiO2 was carried out by response surface methodology to achieve maximized electrical properties. The fabrication was planned by central composite design using two variables and one response. To obtain actual responses, the design was performed in laboratory by the conventional methods of ceramics fabrication. The actual responses were fitted into a valid second order algebraic polynomial equation. Then the quadratic model was suggested by response surface methodology. The model was validated by analysis of variance which provided several evidences such as high F-value (153.6), very low P-value (<0.0001), adjusted R-squared (0.985) and predicted R-squared (0.947). Moreover, the lack of fit was not significant which means the model was significant. RESULTS: The model tracked the optimum of the additives in the design by using three dimension surface plots. In the optimum condition, the molars ratio of Bi2O3 and TiO2 were obtained in a surface area around 1.25 point that maximized the nonlinear coefficient around 20 point. Moreover, the model predicted the optimum amount of the additives in desirable condition. In this case, the condition included minimum standard error (0.35) and maximum nonlinearity (20.03), while molar ratio of Bi2O3 (1.24 mol%) and TiO2 (1.27 mol%) was in range. The condition as a solution was tested by further experiments for confirmation. As the experimental results showed, the obtained value of the non-linearity, 21.6, was quite close to the predicted model. CONCLUSION: Response surface methodology has been successful for modeling and optimizing the additives such as Bi2O3 and TiO2 of ZnO-based low voltage varistor to achieve maximized non-linearity properties.