Statistical Experimental Design Research Articles

In vitro evaluation of the osteogenic and antimicrobial potential of porous wollastonite scaffolds impregnated with ethanolic extracts of propolis.

Context: The development of porous devices using materials modified with various natural agents has become a priority for bone healing processes in the oral and maxillofacial field. There must be a balance between the proliferation of eukaryotic and the inhibition of prokaryotic cells to achieve proper bone health. Infections might inhibit the formation of new alveolar bone during bone graft augmentation. Objective: This study aimed to evaluate the in vitro osteogenic behavior of human bone marrow stem cells and assess the antimicrobial response to 3D-printed porous scaffolds using propolis-modified wollastonite. Methodology: A fractional factorial design of experiments was used to obtain a 3D printing paste for developing scaffolds with a triply periodic minimal surface (TPMS) gyroid geometry based on wollastonite and modified with an ethanolic propolis extract. The antioxidant activity of the extracts was characterized using free radical scavenging methods (DPPH and ABTS). Cell proliferation and osteogenic potential using Human Bone Marrow Stem Cells (bmMSCs) were assessed at different culture time points up to 28days. MIC and inhibition zones were studied from single strain cultures, and biofilm formation was evaluated on the scaffolds under co-culture conditions. The mechanical strength of the scaffolds was evaluated. Results: Through statistical design of experiments, a paste suitable for printing scaffolds with the desired geometry was obtained. Propolis extracts modifying the TPMS gyroid scaffolds showed favorable cell proliferation and metabolic activity with osteogenic potential after 21days. Additionally, propolis exhibited antioxidant activity, which may be related to the antimicrobial effectiveness of the scaffolds against S. aureus and S. epidermidis cultures. The mechanical properties of the scaffolds were not affected by propolis impregnation. Conclusion: These results demonstrate that propolis-impregnated porous wollastonite scaffolds might have the potential to stimulate bone repair in maxillofacial tissue engineering applications.

Response surface statistical modeling for optimization of methylene blue adsorption from aqueous solution using chitosan/graphite composites: Isotherm and kinetics studies

ABSTRACT The study aimed to create a chitosan/graphite composite (CGC) using the impregnation method to optimize its adsorptive efficiency for methylene blue dye from synthetic waste water. The composite adsorbent material was synthesized using a chitosan to expanded graphite ratio of 5% and acetic acid and glutaraldehyde. Expanded graphite was prepared by reacting it with H2SO4 and H2O2 for 90 minutes at room temperature. The specific surface area of graphite increased from 1193.75 m2/g to 1223.648 m2/g. The composite adsorbent material was synthesized using the impregnation method, with chitosan to expanded graphite ratio of 75:25. The CGC was characterized using FTIR, XRD, BET, SEM, and point of zero charge analysis. The adsorption of methylene blue dye onto CGC was optimized by response surface statistical experimental design method to achieve a removal efficiency of 98.61% at 5.24 initial concentration, pH of 9.98, and 95.43-minute contact time. The Langmuir isotherm best fitted the adsorption process, with an R2 value of 0.9974 and adsorption capacity of 98 mg/g. The kinetics of adsorption were best fitted to pseudo-second order with K value 0.0378. The composite was found to be the best alternative adsorbent for removing methylene blue dye from textile wastewater.

Analysis of longitudinal wrinkle formation during calendering of NMC811 cathodes under variation of different process parameters

The requirements for the lithium-ion battery (LIB) are constantly increasing. In the nearer future, batteries need to be even more powerful, safer and cheaper. One lever is the optimization of the production in order to minimize production scrap rates. In electrode manufacturing, calendering is an essential process step to adjust the volumetric energy density. However, this process leads to undesirable defects that result in production scrap. In this paper, the formation of longitudinal wrinkles is analyzed using a statistical experiment design. Electrode density, web tension and temperature are varied in two levels during calendering and are examined for their significance with regard to the geometry of the longitudinal wrinkles. Furthermore, the strain and the deformation of the electrode are analyzed. A complex interaction of material and process is revealed with respect to the formation of longitudinal wrinkles. A better understanding of these interactions contributes to optimize the calendering process and to find a solution to avoid longitudinal wrinkles.

A Cost-Effective Pichia pastoris Cell-Free System Driven by Glycolytic Intermediates Enables the Production of Complex Eukaryotic Proteins.

Cell-free systems are particularly attractive for screening applications and the production of difficult-to-express proteins. However, the production of cell lysates is difficult to implement on a larger scale due to large time requirements, cultivation costs, and the supplementation of cell-free reactions with energy regeneration systems. Consequently, the methylotrophic yeast Pichia pastoris, which is widely used in recombinant protein production, was utilized in the present study to realize cell-free synthesis in a cost-effective manner. Sensitive disruption conditions were evaluated, and appropriate signal sequences for translocation into ER vesicles were identified. An alternative energy regeneration system based on fructose-1,6-bisphosphate was developed and a ~2-fold increase in protein production was observed. Using a statistical experiment design, the optimal composition of the cell-free reaction milieu was determined. Moreover, functional ion channels could be produced, and a G-protein-coupled receptor was site-specifically modified using the novel cell-free system. Finally, the established P. pastoris cell-free protein production system can economically produce complex proteins for biotechnological applications in a short time.

Preparation, Optimization, and In-Vitro Evaluation of Brusatol- and Docetaxel-Loaded Nanoparticles for the Treatment of Prostate Cancer.

Challenges to docetaxel use in prostate cancer treatment include several resistance mechanisms as well as toxicity. To overcome these challenges and to improve the therapeutic efficacy in heterogeneous prostate cancer, the use of multiple agents that can destroy different subpopulations of the tumor is required. Brusatol, a multitarget inhibitor, has been shown to exhibit potent anticancer activity and play an important role in drug response and chemoresistance. Thus, the combination of brusatol and docetaxel in a nanoparticle platform for the treatment of prostate cancer is expected to produce synergistic effects. In this study, we reported the development of polymeric nanoparticles for the delivery of brusatol and docetaxel in the treatment of prostate cancer. The one-factor-at-a-time method was used to screen for formulation and process variables that impacted particle size. Subsequently, factors that had modifiable effects on particle size were evaluated using a 24 full factorial statistical experimental design followed by the optimization of drug loading. The optimization of blank nanoparticles gave a formulation with a mean size of 169.1 nm ± 4.8 nm, in agreement with the predicted size of 168.333 nm. Transmission electron microscopy showed smooth spherical nanoparticles. The drug release profile showed that the encapsulated drugs were released over 24 h. Combination index data showed a synergistic interaction between the drugs. Cell cycle analysis and the evaluation of caspase activity showed differences in PC-3 and LNCaP prostate cancer cell responses to the agents. Additionally, immunoblots showed differences in survivin expression in LNCaP cells after treatment with the different agents and formulations for 24 h and 72 h. Therefore, the nanoparticles are potentially suitable for the treatment of advanced prostate cancer.

Exploring the Ocular Absorption Pathway of Fasudil Hydrochloride towards Developing a Nanoparticulate Formulation with Improved Performance.

Rho-kinase (ROCK) inhibitors represent a new category of anti-glaucoma medications. Among them, Fasudil hydrochloride, a selective ROCK inhibitor, has demonstrated promising outcomes in glaucoma treatment. It works by inhibiting the ROCK pathway, which plays a crucial role in regulating the trabecular meshwork and canal of Schlemm's aqueous humor outflow. This study aims to investigate the ocular absorption pathway of Fasudil hydrochloride and, subsequently, develop a nanoparticle-based delivery system for enhanced corneal absorption. Employing the ionic gelation method and statistical experimental design, the factors influencing chitosan nanoparticle (Cs NP) characteristics and performance were explored. Fasudil in vitro release and ex vivo permeation studies were performed, and Cs NP ocular tolerability and cytotoxicity on human lens epithelial cells were evaluated. Permeation studies on excised bovine eyes revealed significantly higher Fasudil permeation through the sclera compared to the cornea (370.0 μg/cm2 vs. 96.8 μg/cm2, respectively). The nanoparticle size (144.0 ± 15.6 nm to 835.9 ± 23.4 nm) and entrapment efficiency range achieved (17.2% to 41.4%) were predominantly influenced by chitosan quantity. Cs NPs showed a substantial improvement in the permeation of Fasudil via the cornea, along with slower release compared to the Fasudil aqueous solution. The results from the Hen's Egg Test Chorioallantoic Membrane (HET-CAM) and Bovine Corneal Opacity and Permeability (BCOP) tests indicated good conjunctival and corneal biocompatibility of the formulated chitosan nanoparticles, respectively. Lens epithelial cells displayed excellent tolerance to low concentrations of these nanoparticles (>94% cell viability). To the best of our knowledge, this is the first report on the ocular absorption pathway of topically applied Fasudil hydrochloride where the cornea has been identified as a potential barrier that could be overcome using Cs NPs.

A comprehensive review of biosurfactant production and its uses in the pharmaceutical industry.

Biosurfactants are naturally occurring, surface-active chemicals generated by microorganisms and have attracted interest recently because of their numerous industrial uses. Compared to their chemical equivalents, they exhibit qualities that include lower toxic levels, increased biodegradable properties, and unique physiochemical properties. Due to these traits, biosurfactants have become attractive substitutes for synthetic surfactants in the pharmaceutical industry. In-depth research has been done in the last few decades, demonstrating their vast use in various industries. This review article includes a thorough description of the various types of biosurfactants and their production processes. The production process discussed here is from oil-contaminated waste, agro-industrial waste, dairy, and sugar industry waste, and also how biosurfactants can be produced from animal fat. Various purification methods such as ultrafiltration, liquid-liquid extraction, acid precipitation, foam fraction, and adsorption are required to acquire a purified product, which is necessary in the pharmaceutical industry, are also discussed here. Alternative ways for large-scale production of biosurfactants using different statistical experimental designs such as CCD, ANN, and RSM are described here. Several uses of biosurfactants, including drug delivery systems, antibacterial and antifungal agents, wound healing, and cancer therapy, are discussed. Additionally, in this review, the future challenges and aspects of biosurfactant utilization in the pharmaceutical industry and how to overcome them are also discussed.

Understanding factors affecting the process efficiency, quality and carbon emission in laser drilling of CFRP composite via tailored sequence multiple-ring scanning

Carbon fibre reinforced polymer (CFRP) is increasingly being used in the aerospace, marine, and land transport due to its lightweight, corrosion resistance, and high strength. However, hole drilling during assembly remains challenging due to extensive tool wear and delamination. Laser processing, typically used for drilling and machining, often produces heat effects or is low in efficiency if ultrashort pulse lasers are used. Here, we report an optimised result for a tailored sequence multiple-ring scanning laser drilling method that significantly improves the process efficiency (up to 800 %) by using a continuous wave high power fibre laser operating in pulse mode. Factors such as ring numbers, ring spacing (hatch distance), laser power, and pulse frequency are investigated using statistical design of experiments, and their interactions and effects on process efficiency, carbon emissions, heat-affected zone size, and hole taper are evaluated. The work shows that process efficiency can be significantly increased as the number of rings increases. This is counter-intuitive and would be useful for industrial applications. Using nitrogen as the assist gas results in significantly lower unit process carbon emissions than using argon. The mechanisms behind this efficiency improvement are discussed.

Carbon and nitrogen optimization in solid-state fermentation for sustainable sophorolipid production using industrial waste.

The use of alternative feedstocks such as industrial or food waste is being explored for the sustainable production of sophorolipids (SLs). Microbial biosurfactants are mainly produced via submerged fermentation (SmF); however, solid-state fermentation (SSF) seems to be a promising alternative for using solid waste or byproducts that could not be exploited by SmF. Applying the advantages that SSF offers and with the aim of revalorizing industrial organic waste, the impact of carbon and nitrogen sources on the relationship between yeast growth and SL production was analyzed. The laboratory-scale system used winterization oil cake as the solid waste for a hydrophobic carbon source. Pure hydrophilic carbon (glucose) and nitrogen (urea) sources were used in a Box-Behnken statistical design of experiments at different ratios by applying the response surface methodology. Optimal conditions to maximize the production and productivity of diacetylated lactonic C18:1 were a glucose:nitrogen ratio of 181.7:1.43(w w-1 based on the initial dry matter) at a fermentation time of 100h, reaching 0.54 total gram of diacetylated lactonic C18:1 with a yield of 0.047g per gram of initial dry mass. Moreover, time course fermentation under optimized conditions increased the SL crude extract and diacetylated lactonic C8:1 production by 22% and 30%, respectively, when compared to reference conditions. After optimization, industrial wastes were used to substitute pure substrates. Different industrial sludges, OFMSW hydrolysate, and sweet candy industry wastewater provided nitrogen, hydrophilic carbon, and micronutrients, respectively, allowing their use as alternative feedstocks. Sweet candy industry wastewater and cosmetic sludge are potential hydrophilic carbon and nitrogen sources, respectively, for sophorolipid production, achieving yields of approximately 70% when compared to the control group.

Green approach for the synthesis of acrylonitrile hyperbranched polymer/chitosan for the uptake of diclofenac from water: Determination of the optimal conditions by the statistical design of experiment.

Acrylonitrile hyperbranched polymer/chitosan composite (AC-Hyp/CS) material was synthesized for the removal of diclofenac. In this method a hyperbranched polymer was prepared by the crosslinking of acrylonitrile monomer to get a...

Development of a method to assess the dissolution of soft gelatin capsules containing progesterone in oily suspension

Progesterone is a class II active pharmaceutical ingredient according to the biopharmaceutics classification system, so its absorption is affected by solubility and dissolution rate. The work aimed to develop a dissolution method applicable to soft gelatin capsules of 100 and 200 mg of progesterone. Sink conditions were established based on solubility studies; the dissolution apparatus was selected, and the operational conditions of the method were established using an experimental statistical design. The established conditions were challenged in progesterone products, for which their result was already known from in vivo studies, with the same formulation but different particle size, to evaluate the discriminatory power of the method. The dissolution conditions selected were: United States pharmacopoeia apparatus 3, speed of 30 deeps per minute, dissolution media of 250 ml phosphate buffer solution at pH 6.8 with 4% sodium lauryl sulfate, 30 and 40 mesh at the top and bottom of the cell, respectively, and using a sinker for each capsule evaluated. The method proved to be discriminatory for the formulations studied. In addition to being functional for the evaluation of progesterone release at the product development stage, this method is also useful as a product quality control test.

Enhancing Predictive Quality in HVOF Coating Technology: A Comparative Analysis of Machine Learning Techniques

This paper presents a comparative analysis of the performance of machine learning techniques for enhancing predictive quality in thermal spray coating technology, with a focus on the high velocity oxygen fuel (HVOF) process. The study aims for accurately predicting coating properties, which are pivotal in determining coating quality in HVOF applications. By investigating five influential factors, including the fuel-to-oxygen ratio and coating velocity, this research was designed to improve the understanding and control of these properties. Through advanced statistical design of experiments, correlations between these factors and key coating properties are established. Six machine learning models are trained and evaluated to assess their predictive capabilities for coating properties. The obtained results provide valuable insights into the HVOF coating process and highlight the potential of predictive model-based techniques for accurately predicting such properties. Furthermore, this research offers guidance for selecting an effective machine learning technique in the context of thermal spray technology.

Mathematical Analysis of Statistical Design of Experiment and Machine Learning Methods in Identifying Factors Influencing Obesity

Mathematical Analysis of Statistical Design of Experiment and Machine Learning Methods in Identifying Factors Influencing Obesity

Statistical Design of Experiments for Power System Protection Testing: A Case Study for Distance Relay Performance Testing

Statistical Design of Experiments for Power System Protection Testing: A Case Study for Distance Relay Performance Testing

Optimization of the Removal of Hexavalent Chromium Cr(VI) from Aqueous Solution by Moringa oleifera Bark-Derived Activated Carbon (MOBAC) Using Response Surface Methodology (RSM)

This study investigated the removal of hexavalent chromium Cr(VI) ions in an aqueous solution using Moringa oleifera bark-derived activated carbon (MOBAC). The adsorption removal of Cr(VI) was systematically investigated as a function of four experimental factors: pH (1-5), contact time (10-90 min), adsorbent dosage (0.020-0.100 g L-1), and temperature (25-45°C) by following a statistical experimental design. A response surface methodology (RSM)-based central composite experimental design was used to establish an empirical model that assessed factors' effects on Cr(VI) ions adsorptive removal. The model was verified and validated and used to predict optimal adsorption removal of Cr(VI) from aqueous solutions. At optimized conditions, 99.612 % of 1.5 mg L-1 Cr(VI) ions are removed from the aqueous solution. These optimum condition values include a pH of 2.1, contact time of 62.72 min, adsorbent dosage of 0.065 g L-1, and temperature of 39.8°C. The adsorptive mechanism was assessed by conducting isotherm and kinetic studies. The adsorption process of Cr(VI) ions by MOBAC is described by Langmuir isotherm, indicating monolayer adsorption, and the reaction kinetics is described by pseudo-second order kinetics model. The Langmuir monolayer adsorption capacity of Cr(VI) adsorption on MOBAC was found to be 4.577 mg g-1 for Cr(VI) ions. The findings support the use of MOBAC in the removal of Cr(VI) ions from aqueous systems.

Design optimization of staggered-arranged battery thermal management system using an integrated approach of physics-based simulations and evolutionary algorithms

The widely used Lithium-ion battery cells (LIBs) are very sensitive to the operating temperature, which impacts the cycle life and sometimes even leads to thermal overshoot. Hence, a battery thermal management system (BTMS) is required to maintain the temperature of the batteries within the optimum range and maintain the temperature uniformity among the battery pack. A BTMS can be configured in different architectures and either the air or a liquid can be used as a heat transfer fluid. Finding an optimum architecture configuration of BTMS is challenging which requires an economical solution based on comprehensive numerical parametric investigation and multidisciplinary design optimization. In addition, there are lot of uncertainties in design variables (inputs) which could affect the thermal performance of the battery. Therefore, this work proposes a comprehensive study on the design optimization of staggered-arranged BTMS air cooling system using an integrated approach of physics-based simulation (computational fluid dynamics simulations), parametric optimization using statistical design of experiments and evolutionary algorithms such as genetic algorithm (GA), and particle swarm optimization (PSO). The proposed approach incorporates the findings obtained from physics-based simulations in evolutionary algorithms to guide the solutions to obtain efficient and close-to-realistic solution. The numerical model has been mathematically validated using a variety of empirical heat-transfer correlations, and the outcomes are in good concurrence with one another. The comparative analysis investigation reveals that GA outperformed PSO and the optimization process yielded significant improvements including 0.627 % reduction in maximum temperature, 49.18 % decrease in maximum temperature difference, 102.379 % increase in pressure drop, and 6.804 % increment in volume. Conclusions are made and research recommendations are proposed for the future work.

Chemical recycling of green poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)-based air filters through hydrolysis

Sustainable alternatives based on biodegradable polymers, such as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), can potentially reduce the environmental impact generated by the massive disposal of face masks. However, the destination of this biodegradable material in post-consumer landfills or composting consumes energy and does not necessarily reduce environmental damage. Therefore, it is necessary to find ways to return this material to the chemical chain, such as chemical recycling through hydrolysis. In this context, the present work aimed to produce face masks by solution blow spinning (SBS) from solutions containing 4, 6, and 8 m/v% of PHBV and assess the polymer recyclability through hydrolysis. The filters were subjected to hydrolytic reactions in aqueous solutions with pH values of 4, 7, and 10 at 40, 60, and 80 °C for three weeks based on a standard statistical design of experiments (DoE). The fibers produced with solutions containing 4 m/v% of polymer provided the highest weight loss of 68 wt% after three weeks immersed in an aqueous solution (pH = 4 at 80 °C), exhibiting the lowest environmental impact during the chemical recycling process. The ANOVA analyses showed that the fiber diameter was the most significant factor during the recycling reactions, evidencing that materials should be designed to promote the principles of the circular economy. Based on the obtained results, it can be concluded that PHBV-based face mask filters can promote the principles of the circular economy if polymer fibers are correctly designed. Finally, they can also potentially reduce the environmental damage of face mask disposal as long as the recycling process is in place with a proper collection and sorting system.

Quality Analysis of Micro-Holes Made by Polymer Jetting Additive Manufacturing.

Material jetting technology is gaining popularity, especially in polymer science, because of their high accuracy for additive manufacturing (AM) products. This paper aims to investigate the quality of micro-holes that are oriented in three basic directions, and manufactured by the material jetting AM process. This paper proposes a novel methodology to evaluate the accuracy of micro-holes features by using a transparent artifact. A test artifact with horizontal and vertical micro-holes in it, with industrial applications, was designed. Micro-holes were placed on planar and curve surfaces. Samples were manufactured by PolyJet technology from a translucent photopolymer resin which allows a facile investigation (by microscopy) of the inner structure of the micro-holes. The features of ten micro-holes printed in matte and glossy finish type, with diameters in coarse and medium options, according to ISO/ASTM 52902, were analyzed. Quality analysis of the micro-holes features was performed by microscopy investigations. The effects of main factors on the deviation of the micro-hole diameter were investigated by using the statistical design of experiments, and four control factors were considered. The best results were obtained for sample printed in matte finishing with the micro-holes oriented along the x-axis and z-axis. The smallest diameter of the micro-holes obtained by PolyJet technology on an EDEN 350 machine was 0.5 mm, but in industrial applications for a facile post-processing, a higher diameter is recommended to be used. A confirmatory experiment on a wing sample, with a number of micro-holes of the same diameter and a large length to diameter ratio of the micro-holes, was performed, and the repeatability of the results was confirmed.

Methane fermentation to methanol (biological gas‐to‐liquid process) usingMethylotuvimicrobium buryatense5GB1C

AbstractMethanol is a potential alternate liquid transportation fuel for blending with gasoline. Biochemical conversion of methane to methanol is a green process for methanol production. This paper reports biochemical methanol production using type I γ‐proteobacteriaMethylotuvimicrobium buryatense, which has particular importance from the viewpoint of scalable biological gas to liquid processes for industrial application. A statistical design of experiments (at the serum bottle level) was used to optimize fermentation parameters. Enhancement in methanol accumulation was attempted using methanol dehydrogenase inhibitors. This was followed by a validation experiment run in a bioreactor at optimum conditions. At optimum conditions (pH = 7, phosphate concentration = 140 mM, temperature = 25°C) and optical density (600 nm) of 0.3, a methanol titer of 8.54 mM was achieved in 24 h (methane conversion = 20.8%). The addition of a methanol dehydrogenase inhibitor (0.5 mM Ethylenediaminetetraacetic acid) enhanced the methanol concentration to 10.37 mM. Experiments in a 3.7 L bioreactor using 1.68 bar headspace pressure and optical density (600 nm) of 0.1 yielded 23.7 mM methanol in 24 h (methane conversion = 47.8%). The methanol titers obtained usingM. buryatense5GB1C in 24 h fermentation are significantly higher than several previously reported methanotrophs. These results demonstrate the potential ofM. buryatense5GB1C for the biochemical synthesis of methanol.

Synthetic Homoserine Lactone Sensors for Gram-Positive Bacillus subtilis Using LuxR-Type Regulators.

A universal biochemical signal for bacterial cell-cell communication could facilitate programming dynamic responses in diverse bacterial consortia. However, the classical quorum sensing paradigm is that Gram-negative and Gram-positive bacteria generally communicate via homoserine lactones (HSLs) or oligopeptide molecular signals, respectively, to elicit population responses. Here, we create synthetic HSL sensors for Gram-positive Bacillus subtilis 168 using allosteric LuxR-type regulators (RpaR, LuxR, RhlR, and CinR) and synthetic promoters. Promoters were combinatorially designed from different sequence elements (-35, -16, -10, and transcriptional start regions). We quantified the effects of these combinatorial promoters on sensor activity and determined how regulator expression affects its activation, achieving up to 293-fold activation. Using the statistical design of experiments, we identified significant effects of promoter regions and pairwise interactions on sensor activity, which helped to understand the sequence-function relationships for synthetic promoter design. We present the first known set of functional HSL sensors (≥20-fold dynamic range) in B. subtilis for four different HSL chemical signals: p-coumaroyl-HSL, 3-oxohexanoyl-HSL, n-butyryl-HSL, and n-(3-hydroxytetradecanoyl)-HSL. This set of synthetic HSL sensors for a Gram-positive bacterium can pave the way for designable interspecies communication within microbial consortia.