Screening for frequently detected quaternary ammonium mixture systems in waters based on frequent itemset mining and prediction of their toxicity.

Screening and prioritizing research on frequently detected mixture systems in the environment is of great significance, as conducting toxicity testing on all mixtures is impractical. Therefore, the frequent itemset mining (FIM) was introduced and applied in this paper to identify variables that commonly co-occur in a dataset. Based on the dataset of the quaternary ammonium compounds (QACs) in the water environment, the four frequent QAC mixture systems with detection rate ≥ 35 % were found, including [BDMM]+Cl--[BTMM]+Cl- (M1), [BDMM]+Cl--[BHMM]+Cl- (M2), [BTMM]+Cl- -[BHMM]+Cl- (M3), and [BDMM]+Cl--[BTMM]+Cl--[BHMM]+Cl- (M4). [BDMM]+Cl-, [BTMM]+Cl-, and [BHMM]+Cl- are benzyl dodecyl dimethyl ammonium chloride, benzyl tetradecyl dimethyl ammonium chloride, and benzyl hexadecyl dimethyl ammonium chloride, respectively. Then, the toxicity of the representative mixture rays and components for the four frequently detected mixture systems was tested using Vibrio qinghaiensis sp.-Q67 (Q67) as a luminescent indicator organism at 0.25 and 12 h. The toxicity of the mixtures was predicted using concentration addition (CA) and independent action (IA) models. It was shown that both the components and the representative mixture rays for the four frequently detected mixture systems exhibited obvious acute and chronic toxicity to Q67, and their median effective concentrations (EC50) were below 7 mg/L. Both CA and IA models predicted the toxicity of the four mixture systems well. However, the CA model had a better predictive ability for the toxicity of the M3 and M4 mixtures than IA at 12 h.

Optimization of total flavonoids purification process in rose by uniform design method.

This study aims to establish a method for purifying total flavonoids in roses using macroporous resin columns, intending to leverage and harness their potential. We screened six macroporous resins to evaluate their capacity for their adsorption and desorption, ultimately identifying X5 macroporous resin as the most effective. To comprehensively understand the adsorption behavior, we analyzed it using various models, such as pseudo-first-order and pseudo-second-order kinetic models, particle diffusion models, and Langmuir, Freundlich, and Temkin isotherm models. Employing both single-factor and uniform design, approaches, the focus of this work was on maximizing the total flavonoid recovery rate. A 3-factor and 10-level uniform design table was utilized for optimizing the optimal process parameters and exploring the antioxidant properties of the purified flavonoids. The optimal process conditions for purifying total flavonoids from roses can be summarized as follows: a sample concentration of 2 mg/mL, pH at 2, 55 mL sample volume, eluent ethanol concentration of 75%, eluent volume of 5 BV, and the elution rate set at 1 mL/min. Following purification, the total flavonoid content peaked at 57.82%, achieving an 84.93% recovery rate, signifying substantial antioxidant potential. Consequently, the method established for purifying TFR using X5 macroporous resin in this study proves to be a dependable and reliable method consistent approach.

Optimization of the proportions of advantageous components in the hypolipidemic "bioequivalent substance system" of Jiang-Zhi-Ning and its mechanism of action.

CONTEXT: Jiang-Zhi-Ning (JZN), a traditional Chinese medicinal formula, is used to treat hyperlipidemia in clinics. OBJECTIVE: To screen the hypolipidemic "bioequivalent substance system (BSS)" of JZN and elucidate the potential hypolipidemic mechanism. MATERIALS AND METHODS: In vitro, the TG content in HepG2 cells was determined after the intervention of the combination of advantageous components (CAC) by uniform design. In vivo, hyperlipidemia models were established by Triton WR-1339 (400 mg/kg; i.p.) in male ICR mice, and corresponding treatments were administered via oral administration once. The mice were divided into 12 groups (n = 5): control, hyperlipidemic model, simvastatin (positive control, 20 mg/kg), gradient doses of JZN granules (2, 4 and 8 g/kg) and the hypolipidemic effective extraction (HEE) of JZN (120, 240 and 480 mg/kg) and CAC groups (20, 40 and 160 mg/kg). Serum TC, TG, LDL-C and HDL-C were performed after 24 h. Transcriptomics and qRT-PCR technology were used to explore the mechanism of the "BSS" of JZN. RESULTS: In vitro, the ratio of CAC was determined. CAC could reduce the TG content in HepG2 cells (77.21%). Compared with the model group, the high dose of CAC could markedly decrease the levels of TC (61.86%), TG (105.54%) and LDL-C (39.38%) and increase the level of HDL-C (232.67%). CAC was proved to be the "BSS". Transcriptomics and qRT-PCR analysis revealed CAC regulated non-alcoholic fatty liver disease, bile secretion, PPAR and adipocytokine signalling pathway. DISCUSSION AND CONCLUSIONS: These findings provided new feasible ideas and methods for the elucidation of the pharmacodynamic material basis.

Optimization by uniform design U8 (83 ) approach for enhanced caffeine degradation in synthetic wastewater in bioreactor.

Coffee wastewater contains large amounts of caffeine which affects microflora and seed development to great extent. Although several physio-chemical methods available for caffeine degradation, they are not preferred for large-scale treatment. In this study, we optimized induced cell concentration, aeration and agitation rate for maximizing caffeine degradation rate in bioreactor using Uniform design. Maximum caffeine degradation rate of 23·59 mg L-1 h-1 was achieved. The reduction in chemical oxygen demand, biological oxygen demand and total organic carbon removal were found to be 72, 78 and 72% respectively. Mathematical model was developed through regression analysis and predicted maximum caffeine degradation rate of 24·2 mg L-1 h-1 under optimal conditions of 0·35 g L-1 biomass, 395 rev min-1 and 1·62 vvm. Experimental validation at optimum condition resulted in 22 mg L-1 h-1 of caffeine degradation rate. This is the first-ever bioreactor study showing highest caffeine degradation rate in synthetic coffee wastewater with limited experimental runs.

Robust optimization of convolutional neural networks with a uniform experiment design method: a case of phonocardiogram testing in patients with heart diseases.

BACKGROUND: Heart sound measurement is crucial for analyzing and diagnosing patients with heart diseases. This study employed phonocardiogram signals as the input signal for heart disease analysis due to the accessibility of the respective method. This study referenced preprocessing techniques proposed by other researchers for the conversion of phonocardiogram signals into characteristic images composed using frequency subband. Image recognition was then conducted through the use of convolutional neural networks (CNNs), in order to classify the predicted of phonocardiogram signals as normal or abnormal. However, CNN requires the tuning of multiple hyperparameters, which entails an optimization problem for the hyperparameters in the model. To maximize CNN robustness, the uniform experiment design method and a science-based methodical experiment design were used to optimize CNN hyperparameters in this study. RESULTS: An artificial intelligence prediction model was constructed using CNN, and the uniform experiment design method was proposed to acquire hyperparameters for optimal CNN robustness. The results indicate Filters ([Formula: see text]), Stride ([Formula: see text]), Activation functions ([Formula: see text]), and Dropout ([Formula: see text]) to be significant factors considerably influencing the ability of CNN to distinguish among heart sound states. Finally, the confirmation experiment was conducted, and the hyperparameter combination for optimal model robustness was Filters ([Formula: see text]) = 32, Kernel Size ([Formula: see text] = 3 × 3, Stride ([Formula: see text]) = (1,1), Padding ([Formula: see text] as same, Optimizer ([Formula: see text] as the stochastic gradient descent, Activation functions ([Formula: see text]) as relu, and Dropout ([Formula: see text]) = 0.544. With this combination of parameters, the model had an average prediction accuracy rate of 0.787 and standard deviation of 0. CONCLUSION: In this study, phonocardiogram signals were used for the early prediction of heart diseases. The science-based and methodical uniform experiment design was used for the optimization of CNN hyperparameters to construct a CNN with optimal robustness. The results revealed that the constructed model exhibited robustness and an acceptable accuracy rate. Other literature has failed to address hyperparameter optimization problems in CNN; a method is subsequently proposed for robust CNN optimization, thereby solving this problem.

Improvement of Model Predictive Current Control Sensing Strategy for a Developed Small Flux-Switching Permanent Magnet Motor.

This paper presents an improved control system for a small flux-switching permanent magnet motor (FSPM) to enhance its performance and torque sensing. The analytical magnetic circuit design was used to determine the related motor parameters, such as the air gap flux density, permeance coefficient (Pc), torque, winding turns, pole number, width, length, magnet geometry, and the current density of FSPM. The electromagnetic analysis of this motor was performed by software (ANSYS Maxwell) to optimize the motor performance. In this study, the performance of FSPM was investigated by the uniform design experimentation (UDE). For the control system, the model predictive current control (MPCC) is currently recognized as a high-performance control strategy, due to its quick response and simple principle. This model contained the nonlinear part of the system, to improve the torque ripple of FSPM. A modified MPCC strategy was proposed to improve the distortion of the current waveform and decrease the computational burden. The new modified control architecture was mainly composed of three parts, such as the estimation of electromotive force (EMF), current prediction, and optimal vector selection/vector duration. When the reference voltage vector was obtained, the three-phase duties were easily determined by the principle of space vector modulation (SVM). The results show the different strategy methods between the newly proposed modified MPCC and traditional proportional integral (PI) controller. In the control of FSPM, a modified MPCC strategy was able to achieve a better performance response and decrease the computational burden. At a low speed of 350 rpm, the proposed modified MPCC can achieve a better dynamic response. The nonlinear problem of the startup speed was also effectively resolved. The torque sensing performance of the simulation and the experimental test value were compared. The torque sensing performance of the simulation and the actual test value were also examined. In this study, the optimization focused not only on the motor design and fabrication, but also on an improved motor control strategy and torque sensing, in order to achieve the integrity of the FSPM system.

Optimizing sludge dewatering with a combined conditioner of Fenton's reagent and cationic surfactant.

Enhancing sludge dewatering is of importance in reducing environmental burden and disposal costs. In this work, a cationic surfactant, cetyl trimethyl ammonium bromide (CTAB), was combined with Fenton's reagent for sludge dewatering. Results show that the Fenton-CTAB conditioning significantly promotes the sludge dewatering. Using combined techniques of response surface methodology and uniform design, dosages of Fe2+, H2O2, and CTAB for water content response were optimized to be 89, 276, and 233 mg/g dry solids (DS), respectively. The water content of sludge decreased from 79.0% to 66.8% under the optimal conditions. Compared with cationic polyacrylamide, the Fenton-CTAB system exhibited superior sludge dewatering performance. To gain insights into the mechanisms involved in sludge dewatering, the effects of Fenton-CTAB conditioning on the composition of extracellular polymeric substances (EPS) and the morphology of the sludge flocs were investigated. The decomposition of EPS into some dissolved organics and the release of proteins in tightly bound EPS facilitated the conversion of bound water to free water and further reduced the water content of sludge cake. After conditioning, morphology of sludge showed aggregation. Overall, the enhanced sludge dewatering by Fenton-CTAB treatment provides an efficient way for management of sewage sludge.

[Ethanol extraction technology of Epimedii Folium and protective effect of ethanol extract on chondrocyte].

Uniform design-comprehensive scoring method was used to investigate the effects of ethanol dosage, ethanol concentration and extraction time, based on the evaluation index from transfer rates of epimedin A, epimedin B, epimedin C, icariin and baohuoside Ⅰ, which are the main active components in Epimedii Folium. Furthermore, the optimum conditions for the ethanol extraction process were determined by multiple linear stepwise regression and empirical test. Then, the ethanol extract of Epimedii Folium prepared according to the optimized technological conditions was used to intervene the injury model of chondrocyte induced by interleukin-1 beta(IL-1ß). Annexin V-FITC/PI staining flow cytometry was used to detect the apoptotic rate of chondrocyte and analyze the effect of ethanol extract of Epimedii Folium on chondrocyte injury model. The optimum conditions of ethanol extraction were as follows. Crude powder of Epimedii Folium was added with 18 times of 70% ethanol solution, and extracted for twice in the refluxing process, for 60 minutes each time. Under the conditions, the extraction rates of the above five active components were 94.21%, 94.76%, 93.85%, 96.17% and 96.85%, respectively. The optimized ethanol extraction process of Epimedii Folium was reasonable, feasible and reproducible. This ethanol extract could significantly reduce the early apoptotic rate, late apoptotic and necrotic rate, total apoptotic rate(P<0.05 or P<0.01) of chondrocyte injury model induced by IL-1ß, suggesting that the ethanol extract of Epimedii Folium can inhibit the apoptosis of chondrocytes induced by IL-1ß to a certain extent, which lays a foundation for further study on its prevention and treatment of osteoarthritis.

Rapid and simultaneous analysis of tetrabromobisphenol A and hexabromocyclododecane in water by direct immersion solid phase microextraction: Uniform design to explore factors.

Direct immersion solid phase microextraction (DI-SPME) coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS) is of significant research interest because of its low solvent consumption, simple design, and efficient, sensitive, fast performance. In this work, a combination of these two methods (DI-SPME-LC-MS) for the determination of tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD) in water was developed. Important factors, which included temperature, stirring rate, salt concentration, pH value and adsorption time, were evaluated in for the optimization of solid phase microextraction (SPME) method. The method was developed using spiked natural waters in a concentration range of 0.1-10 ng mL-1, and showed notable linearity with regression coefficients ranging between 0.992 and 0.999. The limits of detection varied from 0.01 to 0.04 ng mL-1 (at S/N = 3) and relative standard deviation (RSD < 11%) were obtained showing that the precision of the method was reliable. Recoveries were in relatively high levels for both analytes and ranged from 88% to 108%. Moreover, in comparison with the performance time of traditional sample pretreatment methods such as solid-phase extraction (SPE), accelerated solvent extraction (ASE), and liquid-liquid extraction (LLE), DI-SPME-LC-MS takes only approximately 35 min to perform. The optimized method was successfully applied for monitoring concentrations of TBBPA and HBCD in water.

Process optimization of the extraction condition of ß-amylase from brewer's malt and its application in the maltose syrup production.

ß-Amylase is of important biotechnological aid in maltose syrup production. In this study, the extraction condition of ß-amylase from brewer's malt and the optimal dosage of ß-amylase in maltose syrup production were optimized using response surface methodology and uniform design method. The optimal extraction condition of ß-amylase from brewer's malt was composed of 1:17 (g/v) material/liquid ratio, 44°C extraction temperature, pH 6.4 buffer pH, 2.3 H extraction time, and 1.64 g L-1 NaSO3 dosage with a predicted ß-amylase activity of 1,290.99 U g-1 , which was close to the experimental ß-amylase activity of 1,230.22 U g-1 . The optimal dosages of ß-amylase used in maltose syrup production were 455.67 U g-1 starch and its application in maltose syrup production led to a 68.37% maltose content in maltose syrup, which was 11.2% and 28.9% higher than those using ß-amylases from soybean and microbe (P < 0.01). Thus, ß-amylase from brewer's malt was beneficial for production of high maltose syrup.

A comparative experimental study of the anaerobic treatment of food wastes using an anaerobic digester with a polyamide stirring rake or a stainless-steel stirring rake.

A low treatment capacity and unstable operation are the main drawbacks of the anaerobic digestion of food wastes. The present work improved the efficiency and stabilization of the anaerobic digestion of food wastes using digesters with a polyamide stirring rake (DPSR) and compared it to a traditional digester with a stainless-steel stirring rake (DSSSR). The DPSR had a higher reliability and produced 3.97 times the methane yield of DSSSR in batch experiments at high loading rates (105 VS/L). Uniform design experiments were applied to investigate the relationship between methane yield and the stirring factors of the DPSR. A regression analysis of the uniform design indicated that stirring factors synergistically affect methane yield. The experiment verifying the optimal conditions showed that in the DPSR with 82 r/min stirring intensity and 10 min/d stirring time, the first 20 days of methane yield (392.1 mL/g VS) achieved to 85.26% of the theoretically derived methane yield. In brief, in the anaerobic digestion of food wastes for high methane production and stable operation, the DPSR was more beneficial for the anaerobic digestion of food wastes than the DSSSR.

Global concentration additivity and prediction of mixture toxicities, taking nitrobenzene derivatives as an example.

The toxicity of a mixture depends not only on the mixture concentration level but also on the mixture ratio. For a multiple-component mixture (MCM) system with a definite chemical composition, the mixture toxicity can be predicted only if the global concentration additivity (GCA) is validated. The so-called GCA means that the toxicity of any mixture in the MCM system is the concentration additive, regardless of what its mixture ratio and concentration level. However, many mixture toxicity reports have usually employed one mixture ratio (such as the EC50 ratio), the equivalent effect concentration ratio (EECR) design, to specify several mixtures. EECR mixtures cannot simulate the concentration diversity and mixture ratio diversity of mixtures in the real environment, and it is impossible to validate the GCA. Therefore, in this paper, the uniform design ray (UD-Ray) was used to select nine mixture ratios (rays) in the mixture system of five nitrobenzene derivatives (NBDs). The representative UD-Ray mixtures can effectively and rationally describe the diversity in the NBD mixture system. The toxicities of the mixtures to Vibrio qinghaiensis sp.-Q67 were determined by the microplate toxicity analysis (MTA). For each UD-Ray mixture, the concentration addition (CA) model was used to validate whether the mixture toxicity is additive. All of the UD-Ray mixtures of five NBDs are global concentration additive. Afterwards, the CA is employed to predict the toxicities of the external mixtures from three EECR mixture rays with the NOEC, EC30, and EC70 ratios. The predictive toxicities are in good agreement with the experimental toxicities, which testifies to the predictability of the mixture toxicity of the NBDs.

Anti-inflammatory effect of combined tetramethylpyrazine, resveratrol and curcumin in vivo.

BACKGROUND: Resveratrol and curcumin, as natural flavones products, have good therapeutic effect in acute and chronic inflammation; on the other hand, tetramethylpyrazine (TMP) has angiogenesis and vessel protection effect as well as anti-inflammatory function. In this paper, the anti-inflammatory effect of the tetramethylpyrazine, resveratrol and curcumin (TRC) combination in acute and chronic inflammation was reported in vivo. METHODS: The dose of the combined three natural products was optimized based on the acute paw swelling mouse model with a Uniform Design methodology. The therapeutic effect of TRC combination on chronic inflammation was investigated by using the collagen-induced arthritis (CIA) rat model based upon the following indexes: the volume of paw swelling, arthritis score, serum mediators and histological examination as well as immunohistochemical staining. The levels of alanine aminotransferase (ALT) and aspartate transaminase (AST) in serum were measured and the pathological sections of liver and kidney were analysed. LD50 was measured based on the acute oral toxicity (AOT) standard method. RESULTS: The best formulation was the three components combined at the same mass proportion revealed by the Uniform Design methodology. This combination could significantly reduce the paw swelling in acute paw swelling mouse model, could reduce paw swelling and alleviate the damage in joint structural of ankle, cartilages and fibrous tissue in CIA rat model. The dose relationship was clear in both cases. Immunohistochemical staining of ankle tissue revealed that TRC combination was able to inhibit the expression of NF-κB p65 and TNF-α which were closely related to the inflammatory process. Analysis of serum mediators revealed TRC combination could inhibit the production of TNF-α, IL-1ß, and IL-6 in the serum. Toxic study revealed this formulation was low toxic, LD50 was larger than 5 g/kg, both the level of ALT and AST and histopathology in the liver and kidney exhibited no distinctions between the TRC combination and the blank group, no mortality occurred at the administered doses of 5 g/kg. CONCLUSIONS: The results showed this formulation could provide a novel potent treatment for acute and chronic inflammation (RA) without side effect like gastric injury occurring in NSAIDs.

Evaluation and optimization of the metal-binding properties of a complex ligand for immobilized metal affinity chromatography.

The simultaneous determination of two binding parameters for metal ions on an immobilized metal affinity chromatography column was performed by frontal chromatography. In this study, the binding parameters of Cu(2+) to l-glutamic acid were measured, the metal ion-binding characteristics of the complex ligand were evaluated. The linear correlation coefficients were all greater than 99%, and the relative standard deviations of two binding parameters were 0.58 and 0.059%, respectively. The experiments proved that the frontal chromatography method was accurate, reproducible, and could be used to determine the metal-binding parameters of the affinity column. The effects of buffer pH, type, and concentration on binding parameters were explored by uniform design experiment. Regression, matching and residual analyses of the models were performed. Meanwhile, the optimum-binding conditions of Cu(2+) on the l-glutamic acid-silica column were obtained. Under these binding conditions, observations and regression values of two parameters were similar, and the observation values were the best. The results demonstrated that high intensity metal affinity column could be effectively prepared by measuring and evaluating binding parameters using frontal chromatography combined with a uniform design experiment. The present work provided a new mode for evaluating and preparing immobilized metal affinity column with good metal-binding behaviors.

Identifying the component responsible for antagonism within ionic liquid mixtures using the up-to-down procedure integrated with a uniform design ray method.

Various chemicals in the environment always exist as mixtures. Toxicity interaction within mixtures may pose potential hazards and risks to the environmental safety and human health. Recent studies showed that toxicity interaction by ionic liquid (IL) mixtures can be related to a certain component. To identify the component, we developed a novel procedure integrating an up-to-down process with the uniform design-based ray method (UDUD) and applied it into an IL mixture system of four 1-butyl-3-methylimidazolium ILs (simply [bmim]X) where X=Cl(-), Br(-), CH3OSO3(-) and CH3(CH2)7OSO3(-). It was shown that two mixture rays in the quaternary system exhibited significant antagonistic interaction. In this paper, the UDUD was first employed to design four ternary mixture systems. The microplate toxicity analysis was used to determine the toxicities of various mixtures to a freshwater photobacterium Vibrio qinghaiensis sp.-Q67. The concentration addition was taken as an additive reference to assess the toxicity interactions taking place in mixtures. The results revealed that some ternary mixture rays including [bmim]CH3(CH2)7OSO3 display antagonism while the ternary rays without [bmim]CH3(CH2)7OSO3 exhibit additivity. On these grounds, we again designed all binary mixtures containing [bmim]CH3(CH2)7OSO3, determined their toxicities and assessed toxicity interaction. The results showed that three binary mixture systems produce antagonism. Thus, it may be concluded that [bmim]CH3(CH2)7OSO3 is indeed a key component inducing mixture antagonism.

Effect of different conditions on the germination of coix seed and its characteristics analysis.

Coix seed (CS) has high nutritional value, but the deep processing of CS is relatively limited. Sprouting can significantly improve nutritional value, laying the foundation for efficient consumption or further processing. The optimal conditions for the germination of CS are a soaking temperature of 36 °C for 10 h and a germination temperature of 29 °C for 24 h. Under these conditions, the final germination rate of CS reached 90%. Additionally, the content of γ-aminobutyric acid was 21.205 mg/100 g; soluble protein, free amino acids, γ-aminobutyric acid, and other essential substances increased in CS. Especially after germination, the γ-aminobutyric acid (GABA) content increased by 7.8 times compared with the GABA content of ungerminated CS. Therefore, the nutritional value and flavor of germinated CS are better than those of ungerminated ones, which establishs a solid foundation for its application in developing various products such as compound health drinks, coix yogurt, and others.

Preparation of Phosphorylated Auricularia cornea var. Li. Polysaccharide Liposome Gel and Analysis of Its In Vitro Antioxidant Activity.

In this study, Auricularia cornea var. Li. polysaccharides (ACP) were used as the research object to prepare liposome gel and determine its antioxidant activity in vitro. Phosphorylated Auricularia cornea var. Li. polysaccharides (P-ACP) were prepared via the phosphorylation of ACP by the phosphate method. Additionally, phosphorylated Auricularia cornea var. Li. polysaccharide liposomes (P-ACPL) were prepared using a reverse evaporation method. Finally, phosphorylated Auricularia cornea var. Li. polysaccharide liposome gel (P-ACPLG) was prepared by dispersing the P-ACPL in the gel matrix. The results show that the phosphorylation of the P-ACP was 15.51%, the containment rate of the P-ACPL was 84.50%, the average particle size was (192.2 ± 3.3) nm, and the particle size distribution map had a homogeneous peak, resulting in the particle dispersion being uniform and the polydispersion index (PDI) being 0.134 ± 0.021. The average Zeta potential was (-33.4 ± 0.57) mV. In addition, the in vitro antioxidant activity of the P-ACPL was slightly higher than that of the ACP and P-ACP. After the P-ACPL was emulsified into P-ACPLG, the DPPH, hydroxyl radical clearance, and reducing the ability of P-ACPL remained unchanged. In general, the P-ACPLG prepared in this study has good antioxidant activity in vitro and can retain the antioxidant activity of P-ACPL in vitro well.

Controllable acetylation of cellulose nanocrystal by uniform design and response surface methodology.

Acetylation of Cellulose nanocrystal (CNC) can reduce its surface polarity and therefore extends its application in biomedical and chemical fields. A method combining uniform design (UD) and response surface methodology (RSM) was developed to produce the acetylated CNC with arbitrary degree of substitution (DS) and crystallinity index (CrI). The effects of three factors (i.e., temperature, reaction time and the volume of acetic anhydride) on DS and CrI were investigated in their respective ranges (i.e., 60-90 oC, 1.0-5.0 h and 1.0-5.0 mL). Both mathematical models for DS and CrI were developed by multiple stepwise regression (MSR) based on UD data and their significances were evaluated by analysis of variance. The controllable acetylation of CNC was realized by using either UD alone or the combination of UD and RSM. Eight verification experiments show that the relative errors between the predicted and the measured results are less than 16.77 % and 6.08 % for DS and CrI, respectively, confirming the reliability and validity of the method. This developed methodology is ingenious and expected to be expanded to any other fields that controllable preparations are required.

Quadrotors' double-loop controller design with tensor product model transformation and partial fully actuated method.

In the existing work of tensor product (TP) model transformation, the TP model transformation-based work on the quadrotor's control system design is scarce, the direct TP model transformation control strategy that applied to the quadrotor fails due to the calculation complexity, infeasibility of the huge amount of linear matrix inequalities, and the complexity of solving the linear matrix inequalities. To solve this problem, a partial TP model transformation-based double loop fuzzy controller has been studied in this work, the double-loop hybrid control scheme combines the fully actuated control method and the TP model transformation, while the fully actuated control method is used to the position subsystem control loop, and the TP model transformation based fuzzy controller is applied to the attitude control of the quadrotor. Moreover, for comparison purpose, a varying-input method based on TP model transformation is extended to the quadrotor's system control. The double-loop hybrid control scheme could also be extended with other TP model transformation based tensor sampling methods, such as, uniform sampling method and varying-input method. At last, the proposed algorithms are evaluated and compared on Parrot Mambo Minidrone, MFP450 and CUAV V5+ based hexarotor.

Design, Manufacture, and Characterization of a Critical-Sized Gradient Porosity Dual-Material Tibial Defect Scaffold.

This study proposed a composite tibia defect scaffold with radial gradient porosity, utilizing finite element analysis to assess stress in the tibial region with significant critical-sized defects. Simulations for scaffolds with different porosities were conducted, designing an optimal tibia defect scaffold with radial gradient porosity for repairing and replacing critical bone defects. Radial gradient porosity scaffolds resulted in a more uniform stress distribution, reducing titanium alloy stiffness and alleviating stress shielding effects. The scaffold was manufactured using selective laser melting (SLM) technology with stress relief annealing to simplify porous structure fabrication. The study used New Zealand white rabbits' tibia defect sites as simulation parameters, reconstructing the 3D model and implanting the composite scaffold. Finite element analysis in ANSYS-Workbench simulated forces under high-activity conditions, analyzing stress distribution and strain. In the simulation, the titanium alloy scaffold bore a maximum stress of 122.8626 MPa, while the centrally encapsulated HAp material delivered 27.92 MPa. The design demonstrated superior structural strength, thereby reducing stress concentration. The scaffold was manufactured using SLM, and the uniform design method was used to determine a collection of optimum annealing parameters. Nanoindentation and compression tests were used to determine the influence of annealing on the elastic modulus, hardness, and strain energy of the scaffold.