Box-Behnken Response Surface Method Research Articles

Effect of heat treatment patterns on microstructure and mechanical properties of selective laser melting fabricated SiC/AlSi10Mg composite

Selective laser melting (SLM) of SiC/Al-Si-Mg composites hold tremendous potential for engineering applications. However, there has been a lack of systematic research on their heat treatment patterns. This paper utilizes the Box-Behnken response surface method to establish a relationship model between SLM process parameters and the relative density of the 10 wt%SiC/AlSi10Mg composite. Simultaneously, 300 °C, 400 °C, and 500 °C treatments (T300, T400, T500) were used to investigate the porosity, microstructure, and mechanical properties of the 10 wt%SiC/AlSi10Mg composite. The results indicate that optimal process parameters were laser power of 331 W, scanning speed of 1243 mm/s, and hatching spacing of 120 μm. Under these process parameters, the fabricated samples exhibited a relative density of over 99 % and presented a refined microstructure. The porosity of the as-built (AB) samples remained at a low level of ∼0.38 %, while the porosity of T300, T400, T500 samples increased to ∼0.7 %, ∼0.78 %, ∼0.92 %, respectively. Pores at the molten pool boundary (MPB) of the AB samples expanded into the melt pool inner (MPI) of the T300-T500 samples. The addition of SiC reinforcement significantly improved the strength and hardness of the composite materials, reaching 471 MPa and 151 HV, respectively. After heat treatment, the original fine network microstructure was disrupted due to the fracture, spheroidization growth, and coarsening of the eutectic networks. The elongation of the composite after heat treatment increased substantially from 3 % to 5.95 %, with a decrease in hardness and strength, a transition from brittle to ductile fracture behavior.

Ultrasound-assisted extraction of withanolides from Tubocapsicum anomalum: Process optimization, isolation and identification, and antiproliferative activity

Tubocapsicum anomalum, a Chinese medicinal plant rich in anti-tumor withanolides, requires efficient extraction methods. In this paper, an HPLC method was first established for the detection of withanolides, and gradient elution was carried out using a methanol–water solvent system. It was found that the content of withanolides was the highest in the leaves of T. anomalum, followed by the stems and fruits, and almost none in the roots. During the actual picking process, the quantity of leaves collected was relatively small, while the number of stems was the highest. Therefore, the Box-Behnken response surface method was used to optimize the ultrasonic-assisted extraction process of withanolides from the stems of T. anomalum. The optimal extraction conditions were determined as follows: the liquid–solid ratio was 20:1, the extraction solvent was 70 % ethanol, the ultrasonic power was 250 W, the ultrasonic time was 40 min, and the ultrasonic temperature was 50 °C. Under these conditions, the average yields of tubocapsenolide A (Te-A) and tubocapsanolide A (Ta-A) can reach 2.87 ± 0.12 mg/g and 1.18 ± 0.05 mg/g, respectively. We further compared extraction rates of two withanolides from different parts of T. anomalum using ultrasonic and traditional extraction methods. Ultrasonic extraction significantly increased rates, with the highest yields from leaves, followed by stems and fruits. The results show that ultrasonic optimization can improve extraction rate, reduce time, lower costs, enhance quality, and increase yield. Therefore, the optimized ultrasonic-assisted extraction process was adopted to extract the aerial parts of T. anomalum and separate the components. After optimization, the extract underwent several chromatographic separations to isolate eight previously undescribed withanolides (1–8) and two artificial withanolides (9–10), in addition to fifteen known compounds (11–25). Their structures were established through extensive spectroscopic data analysis. The compounds were evaluated for their antiproliferative effects against multiple cancer cell lines, including human hepatocellular carcinoma cells (HepG2, Hep3B, and MHCC97-H), human lung cancer cells (A549), human fibro-sarcoma cancer cells (HT1080), human chronic myeloid leukemia cells (K562), and human breast cancer cells (MDA-MB-231 and MCF7). Compounds 1–3, 5, 7, 11, 13, 15–16, and 22 displayed significant activity with IC50 values of 5.14–19.87 μM. The above results indicate that ultrasonic-assisted extraction technology can be used to obtain new withanolides more efficiently from T. anomalum, thereby enhancing the utilization rate of T. anomalum resources.

Optimization and Stability Assessment of Monochamus alternatus Antimicrobial Peptide MaltAtt-1 in Komagataella phaffii GS115 for the Control of Pine Wood Nematode.

MaltAtt-1 is an antimicrobial peptide isolated from Monochamus alternatus with nematocidal activity against pine wood nematode. In this study, a eukaryotic expression system based on Komagataella phaffii GS115 was established, and its secretory expression of MaltAtt-1 was realized. The basic properties and secondary and tertiary structures of the antimicrobial peptide MaltAtt-1 were identified by bioinformatics analysis. MaltAtt-1 is a hydrophilic stable protein, mainly composed of an α-helix (Hh), β-folds (Ee), and irregular curls (Cc). The optimal fermentation conditions for MaltAtt-1 were determined by a single-factor test and the Box-Behnken response surface method, including an induction time of 72 h, induction temperature of 30 °C, culture medium of pH 7.6, methanol volume fraction of 2.0%, and an initial glycerol concentration of 1%. The stability of MaltAtt-1 indicated its resistant to UV irradiation and repeated freezing and thawing, but the antibacterial activity decreased significantly under the influence of high temperature and a strong acid and base, and it decreased significantly to 1.1 cm and 0.83 cm at pH 2.0 and pH 10.0, respectively. The corrected mortality of B. xylophilus achieved 71.94% in 3 h at a concentration of 300 mg·L-1 MaltAtt-1 exposure. The results provide a theoretical basis for the antimicrobial peptide MaltAtt-1 to become a new green and efficient nematicide.

Optimization of the extraction process for Shenshou Taiyi powder based on Box-Behnken experimental design, standard relation, and FAHP-CRITIC methods

BackgroundAncient classic prescription play a crucial role in the preservation and advancement of traditional Chinese medicine (TCM) theories. They represent a significant milestone in the ongoing development and transmission of TCM knowledge and practices and are considered one of the breakthroughs in the development of TCM inheritance. In the process of developing ancient classic prescriptions, many problems may still arise in ensuring quality consistency between traditional methods and modern production processes, among which the extraction process poses major challenges. This paper introduces a practical approach extracting an ancient classic prescription using a modern extraction process. The technique is demonstrated through the study of the extraction process of Shenshou Taiyi powder (STP).MethodsThis study focuses on optimising the STP extraction process to ensure consistency in the quality of the product obtained through ancient and modern processes using the standard relation and fuzzy analytic hierarchical process (FAHP) and criteria importance through intercriteria correlation (CRITIC) method integrated weights combined with the Box-Behnken response surface test. Using the contents of rosmarinic acid, isoimperatorin, puerarin, as well as the extract yield and fingerprint similarity as evaluation indexes of STP, the Box-Behnken response surface method was employed to examine the varying extraction parameters, including water addition ratio, extraction duration, and number of extractions. The weighted coefficients for each parameter were calculated by combining the benchmark correlation and FAHP-CRITIC method, deriving a comprehensive score.ResultsThe optimal extraction process for STP consisted of a two extractions, each using at a tenfold quantity of water, performed for one hour. Process verification across three separate batches yielded a comprehensive score of 94.7, with a relative standard deviation of 0.76%.ConclusionsThe application of the Box-Behnken response surface method combined with standard relation and FAHP-CRITIC approach proved to be stable and feasible for optimising the extraction process of STP.

Response Surface Optimization for Water-Assisted Extraction of Two Saponins from Paris polyphylla var. yunnanensis Leaves.

The process of extracting polyphyllin II and polyphyllin VII by water-assisted extraction was established and optimized in this study. Response surface methodology was used to establish a prediction model to optimize the extraction conditions. Based on the one-way test, the Box-Behnken design with three factors and three levels was used for the experimental program, and the composition analysis was carried out by high-performance liquid chromatography (HPLC). The optimal extraction conditions for polyphyllin II and polyphyllin VII were as follows: extraction time of 57 and 21 min, extraction temperature of 36 and 32 °C, solid-to-liquid ratio of 1:10 and 1:5 g/mL, respectively, and the yields of polyphyllin II and polyphyllin VII were 1.895 and 5.010%, which was similar to the predicted value of 1.835 and 4.979%. The results of the ANOVA showed that the model fit was good, and the Box-Behnken response surface method could optimize the water-assisted extraction of saponins from the leaves of Paris polyphylla var. yunnanensis. This study provides a theoretical basis for the application of polyphyllin II and polyphyllin VII in pharmaceutical production.

V-doped MoO3 nanorods for highly selective oxidation of 5-hydroxymethylfurfural to bio-monomer 2, 5-furandicarboxylic acid

2,5-Furanodicarboxylic acid (FDCA) is a significant chemical derived from biomass and holds the potential to replace traditional petrochemicals in the production of biodegradable polyester materials. In this study, a series of new-type V-doped MoO3 catalysts with different crystalline phases were prepared through the hydrothermal method. The V-doped α-MoO3 with growth along the [010] crystal plane demonstrated the most efficient catalytic activity in the selective oxidation of 5-hydroxymethylfurfural (HMF) to produce FDCA, potentially attributable to the [010] crystal plane's superior affinity for substrate interactions. The catalysts were analyzed using TEM, XPS, XRD, FT-IR, N2 adsorption isotherms and other characterization techniques. The Box-Behnken response surface method was utilized to investigate and successfully determine the optimal reaction conditions. A remarkable HMF conversion of 99.5% and a 97.4% selectivity toward FDCA were achieved at 80 °C after 10 h using tert-butanol as the solvent and tert-butyl hydroperoxide as the oxidant. Furthermore, the catalyst could be readily recovered conveniently and reused without any significant loss in catalytic activity.

Establishment of HPLC method and optimization of ultrasonic-assisted extraction process for two lignan active substances in Asarum heterotropoides

In the present study, developed a dependable HPLC technique to quantify asarinin and sesamin in Asarum heterotropoides Fr. Schmidt var. mandshuricum (Maxim.) Kitag. The optimal conditions for the ultrasonic-assisted extraction were determined by conducting single-factor experiment, Plackett-Burman design experiment, and Box-Behnken response surface method. Based on actual operation factors and analysis, the optimal extraction parameters were methanol volume fraction of 80% (v/v), liquid-to-material ratio of 10:1 (mL/g), ultrasonic time of 40 min, ultrasonic temperature of 51°C, and ultrasonic power of 300 W. When subjected to these conditions, the average asarinin and sesamin content were found to be 13.40 mg/g and 2.39 mg/g, respectively, with a relative error of 1.04% and 3.46%, which was consistent with the theoretical value. This study can offer a theoretical reference for the extraction of asarinin and sesamin in Asarum.

Preparation of copolymer 7-hydroxyethyl chrysin loaded PLGA nanoparticles and the in vitro release.

To prepare 7-hydroxyethyl chrysin (7-HEC) loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles and to detect the in vitro release. The 7-HEC/PLGA nanoparticles were prepared by emulsification solvent volatilization method. The particle size, polydispersity index (PDI), encapsulation rate, drug loading and zeta potential were measured. The prescription was optimized by single factor investigation combined with Box-Behnken response surface method. Mannitol was used as protectant to prepare lyophilized powder, and the optimal formulation was characterized and studied for the in vitro release. The optimal formulation of 7-HEC/PLGA nanoparticles was as follows: drug loading ratio of 2.12∶20, oil-water volume ratio of 1∶14.7, and 2.72% soybean phospholipid as emulsifier. With the optimal formulation, the average particle size of 7-HEC/PLGA nanoparticles was (240.28±0.96) nm, the PDI was 0.25±0.69, the encapsulation rate was (75.74±0.80)%, the drug loading capacity was (6.98±0.83)%, and the potentiostatic potential was (－18.17±0.17) mV. The cumulative in vitro release reached more than 50% within 48 h. The optimized formulation is stable and easy to operate. The prepared 7-HEC/PLGA nanoparticles have uniform particle size, high encapsulation rate and significantly higher dissolution rate than 7-HEC.

Ultrasound-assisted Aqueous Two-Phase Extraction of Flavonoids from Scutellariae Radix and Evaluation of their Bioactivities In Vitro

Background: Scutellariae Radix, one of the most widely used herbs in Traditional Chinese Medicine, exhibits various biological activities due to its chemical components, which stand out for a number of flavonoids. In this study, Ultrasound-assisted aqueous two-phase extraction (UAATPE) was employed for the first time to obtain a high extraction rate and high purity of flavonoids from Scutellariae Radix. Methods: The Box-Behnken response surface method (RSM) was utilized to optimize the extraction conditions with the application of the new aqueous two-phase system (ATPS) composed of ethanol and ammonium sulfate. The major influence factors, including ethanol concentration, ammonium sulfate concentration, liquid-to-solid ratio, sonication time, and extraction temperature, were investigated by the single-factor experiment. The compositional characterization of flavonoids was characterized with HPLC-UV. Scanning electron microscopy (SEM) was applied to research the surface morphology of raw material. Furthermore, the bioactivities of the extract obtained by UA-ATPE were studied in vitro. Results: The optimal extraction conditions were as follows: the ethanol content was 26.12% (w/w), the ammonium sulfate content was 20.02% (w/w), the liquid-to-solid ratio was 40 mL/g, the sonication time was 5 min with the ultrasonic power of 250 W, and the operating process was performed at room temperature. Compared with the traditional extraction methods, UA-ATPE exhibited higher extraction efficiency and better extraction selectivity. The DPPH and ABTS radical scavenging tests showed that enriched products possessed strong antioxidant activity. Conclusion: The study confirmed that the developed method of UA-ATPE could be used as an efficient, eco-friendly, and low-consumption method for the extraction and purification of flavonoids from Scutellariae Radix.

Lightweighting Study of Rotary Kiln Cylinder Structure Based on Response Surface

To achieve the lightweight design of the rotary kiln cylinder, reduce its manufacturing costs, and improve its mechanical properties, the maximum stress and deformation were determined through a static and thermal structural analysis of the rotary kiln equipment. Employing the Box-Behnken response surface method, an optimization of the rotary kiln cylinder structure was performed, with the aim of minimizing the cylinder mass and deformation, while considering constraints such as cylinder thickness and yield strength. A multi-objective optimization mathematical model was established, and three sets of Pareto solutions were obtained using a multi-objective genetic algorithm. The optimized design of thickness structure was determined for the stall section, transition section, and cylinder section of the rotary kiln. The finite element method was utilized to simulate the optimized solutions and verify their validity and accuracy. The results showed that the rotary kiln cylinder mass was reduced by 13.8%, and the maximum deformation under static structural conditions was reduced by 4.6%, while maintaining the strength requirement of the structural stiffness. The relevant geometric parameters of the optimal solution were verified by finite element numerical tests, and the optimized cylinder mass, maximum stress and deformation under static structural conditions, and maximum deformation and stress under thermal structural coupling were in good agreement with the numerical test results, with a deviation of less than 2%. Additionally, this study realized the lightweight design of the rotary kiln cylinder and provided useful references for the thickness design of the rotary kiln cylinder.

Preparation of Tetrandrine Nanocrystals by Microfluidic Method and Its In Vitro and In Vivo Evaluation.

The anti-hepatocellular carcinoma effects of TET are acknowledged, but its application is hindered by its poor water solubility and low bioavailability. Conventional methods for nanocrystal preparation are laborious and lack control. To address these limitations, we propose employing the microfluidic method in the preparation of TET nanocrystals, aiming to enhance the aforementioned constraints. The objectives of this study were to prepare TET nanocrystals (TET-NC@GL) using a Y-microfluidic method with glycyrrhetinic acid (GL) as a stabilizer. The optimal preparation prescription was determined through a single-factor test and Box-Behnken response surface method. Additionally, the nanocrystals prepared with the commonly used stabilizer polyvinylpyrrolidone K30 (PVPK30), known as TET-NC@PVPK30, were characterized and evaluated for their toxicity to HepG2 cells. Hybridized nanocrystals (TET-HNC@GL and TET-HNC@PVPK30) were synthesized using a water-soluble aggregation-induced emission (AIE) fluorescent probe (TVP). Qualitative and quantitative cellular uptake experiments were conducted using these hybridized nanocrystals. Conducting in vivo pharmacokinetic assays evaluates the relative bioavailability of nanocrystals. The results indicated that TET-NC@GL, optimized using the response surface method, had a particle size of 136.47 ± 3.31nm and a PDI of 0.219 ± 0.002. The administration of TET-NC@GL significantly enhanced the cell inhibition rate compared to the TET group and the TET-NC@PVPK30 group (P < 0.01). Moreover, the qualitative and quantitative cellular uptake results revealed a significant enhancement in cellular uptake in the TET-HNC@GL administration group compared to the TET-HNC@PVPK30 group (P < 0.01). In vivo pharmacokinetic results showed that the bioavailability of TET-NC@GL group was 3.5 times higher than that of the TET group. The results demonstrate the successful preparation of TET-NC@GL nanocrystals.

The Effect of Ultrasound on the Rehydration Characteristics of Semi-Dried Salted Apostichopus japonicus.

To effectively shorten the rehydration time of Apostichopus japonicus and reduce the nutrient loss during the rehydration process, an ultrasound-assisted rehydration method was adopted to rehydrate semi-dry salted A. japonicus in this study. The effects of different ultrasonic powers, temperatures, and times on the rehydration characteristics, textural characteristics, and sensory quality of the semi-dry salted A. japonicus were studied. Box-Behnken response surface analysis was used to study the influence of the interactions among the three factors on the rehydration ratio of the semi-dry salted A. japonicus, and a quadratic multinomic regression model was established to predict the optimal rehydration ratio. The results showed that ultrasound could change the structure of semi-dry salted A. japonicus and form a spatial network structure, thereby improving its water absorption capacity and reducing rehydration time. The optimal rehydration effect could be obtained when the ultrasonic power was 400 W, the ultrasonic temperature was 50 °C, and the ultrasonic time was 83 min. Ultrasonic power, ultrasonic time, and ultrasonic temperature influenced the rehydration ratio of the semi-dry salted A. japonicus. Under the optimal rehydration conditions in this study, the rehydration ratio of semi-dry salted A. japonicus obtained by the test was 2.103, which was consistent with the value predicted by the Box-Behnken response surface method.

Box–Behnken response surface method for the synthesis of high‐temperature‐ and salt‐resistant filter loss reducers

AbstractWellbores are destabilized by the immersion of a formation in drilling fluid during deep well drilling. To address this issue, in the present study, trimethylolethane triallyl ether (TMETE), 2‐acrylamide‐2‐methylpropanesulfonic acid (AMPS), acrylamide, and N‐vinylpyrrolidone undergo free radical copolymerization to produce a PTAAN filter loss reducer. The Box–Behnken response surface method is used to optimize the synthesis of PTAAN; the optimal conditions are 1 wt% TMETE and 0.1111 wt% initiator at 60°C. Fourier transform infrared spectroscopy, transmission electron microscopy, and thermogravimetric analysis are used to characterize the composition, micromorphology, and thermal stability of the PTAAN product, respectively. The synthesized product is resistant to high temperatures and salt under the optimal synthesis conditions. It has an API filtration loss of 8.2 mL for freshwater‐based mud, an API filtration loss of 13.8 mL for 20% by weight brine mud after aging at 220°C, and an API filtration loss of 29.5 mL at 150°C under high temperatures and pressures. Incorporating PTAAN into the base slurry prevents clay particle agglomeration at elevated temperatures and high mineralization, resulting in a broader clay particle size distribution and ultimately leading to the formation of a thin and compact filter cake.

Particle Behavior and Aperture Optimization of Variable Vibration-Amplitude Screening Based on Discrete Element Method Simulation.

Recently, some novel screens were proposed based on the improved understanding of screening processes from particle-scale studies, one of which is the novel variable amplitude equal thickness vibration screen (VAETVS). This paper presents an investigation of using different aperture sizes to further optimize the VAETVS by the discrete element method (DEM). The screen was divided into three panels, and the aperture size of each panel was varied in the simulation. The particles' dynamics and spatial distribution were investigated to better understand the effects of varied amplitudes and aperture sizes on the screening efficiency. The results showed that the VAETVS can be effectively optimized by varied amplitude as well as varied aperture size for different screen panels. The amplitude variance is more effective for hard sieve particles and hindrance particles. It is also found that from the feed end to the discharge end, the difference in the distribution of particle mass between the coarse particles and the fine particles increases. Generally, such a difference can be increased with increasing aperture sizes. However, the effects of the apertures of the different panels were not the same. The simulated data were further analyzed by the Box-Behnken response surface method, which gave a mathematical model to predict the screening efficiency η with the varied apertures. From the model, the optimal aperture sizes are 7.5, 7.58, and 6.81 mm, yielding the maximum screening efficiency of 86.35%, and the optimal opening areas for the three panels are 35, 40, and 40%, respectively, yielding the maximum screening efficiency of 87.82%.

Box–Behnken optimization of biodiesel production using trisodium phosphate catalyst from monazite ore processes

AbstractTrisodium phosphate (TSP) is a non‐toxic waste obtained from alkaline cracking as part of the processing of monazite ore. After simple purification, TSP can be utilized in many applications; however, it is used as a catalyst in this study. It is characterized using Thermogravimetric analysis , X‐ray diffraction analysis, Brunauer‐Emmett‐Teller, and Temperature‐programmed desorption of carbon dioxide and optimized in the transesterification reaction. After recrystallization and calcination at 350 °C for 0.5 h, the form of the TSP was tetragonal, with a 2.61 m2/g surface area and 537.4 x 10‐6 mol/g basic sites. Trisodium phosphate can therefore be utilized effectively as a solid base catalyst for the transesterification of palm oil. Three biodiesel production parameters were investigated: the methanol to oil molar ratio (6:1–24:1), catalyst concentration (1–10%), and reaction time (30 to 240 min). The experiments were designed using the Box–Behnken response surface method. As a result, the optimum conditions for biodiesel production are a 22:1 methanol to oil molar ratio, 4% catalyst concentration, and 200 min reaction time. The optimal fatty acid methyl ester (FAME) content is 99.79%, with an error between actual and predicted FAME of 0.21%. © 2023 Society of Industrial Chemistry and John Wiley &amp; Sons Ltd.

Experimentation and optimization of laser waterless decontamination rate of residual organic solvents

Laser waterless decontamination is a widely researched area for the high pollution issue of residual organic solvents in industry and agriculture. In this research, a nanosecond pulsed laser was used to conduct waterless decontamination studies on organic solvent residues on the surface of optical glass. A single-factor test was designed using the decontamination rate (Y) as the response value and the laser power (X1), scanning speed (X2), and decontamination times (X3) as the influencing variables. The Raman spectrum reflected the decontamination effect of organic solvent decontamination using a waterless laser. The Box-Behnken response surface method (RSM) was used to design the experiments. The developed RSM was used to determine the link between laser parameters and decontamination rate, and optimum decontamination parameters were determined. In addition, the mathematical model and regression equation were established using Design-Expert. The findings demonstrate that residual solvent may be removed at a rate of up to 95.22%. Optimum values for laser power, scanning speed, and decontamination times are 130 W, 381 mm/s, and 10 times respectively.

Dynamic Cutting Performance Test and Parameter Optimization of Longicorn Bionic Blade for Industrial Hemp Harvester

In response to the unclear issue of whether the dynamic cutting performance and structural parameters of an industrial hemp blade, which was developed earlier based on the bionic prototype of the batocera horsfieldi, can be optimized in actual working conditions, this paper analyzes the effective clamping conditions of a reciprocating double-acting cutting blade for stalks and the cutting motion. To investigate the effect of different structural and motion parameters, as well as their interactions, of the bionic blade on cutting energy consumption, bionic blades with different combinations of tooth pitch and tooth angle were designed. A Box–Behnken response surface method with three factors and three levels was used to design an experimental scheme. Utilizing rigid-flexible coupling numerical simulation technology, numerical simulation experiments were conducted to investigate the cutting performance of industrial hemp stalks using the blade. A regression model for cutting energy consumption was established, and variance analysis indicated that tooth angle, speed ratio, and the interaction between tooth angle and speed ratio had an extremely significant effect on the regression model. The primary and secondary orders of factors affecting cutting energy consumption were determined to be: speed ratio &gt; tooth angle &gt; tooth pitch. Through optimization, the optimal parameter combination was found to be a blade tooth pitch of 6.61 mm, a tooth angle of 30°, and a speed ratio of 1.62. Under these conditions, the cutting energy consumption was 3947.99 mJ. The optimized parameters were verified through numerical simulation cutting experiments, and the results showed that the error compared with the optimization results was only 8.16%. This indicates that the optimization results have high credibility and further verifies the reliability of the model. This study can provide a reference for the development of cutting devices for industrial hemp harvesters and the selection of motion parameters.

Optimization of Processing Technology for Tiebangchui with Zanba Based on CRITIC Combined with Box-Behnken Response Surface Method.

The dried root of Aconitum pendulum Busch., called Tiebangchui (TBC) in Chinese, is one of the most famous Tibetan medicines. It is a widely used herb in northwest China. However, many cases of poisoning have occurred because of TBC's intense toxicity and because its therapeutic and toxic doses are similar. Therefore, finding a safe and effective method to reduce its toxicity is an urgent task. A search through the Tibetan medicine classics shows that the processing method of TBC stir-fried with Zanba was recorded in the "Processing specification of Tibetan medicine of Qinghai Province (2010)". However, the specific processing parameters are not yet clear. Thus, this study aims to optimize and standardize the processing technology of Zanba-stir-fried TBC. First, a single-factor experiment was conducted on four factors: the slice thickness of TBC, amount of Zanba, processing temperature, and time. With monoester and diester alkaloid contents in Zanba-stir-fried TBC as indexes, CRITIC combined with the Box-Behnken response surface method was used to optimize the processing technology of Zanba-stir-fried TBC. The optimized processing conditions of Zanba-stir-fried TBC were a TBC slice thickness of 2 cm, three times more Zanba than TBC, a processing temperature of 125 °C, and 60 min of stir-frying. This study determined the optimized and standard processing conditions for the usage of Zanba-stir-fried TBC, thus providing an experimental basis for the safe clinical use and industrial production of Zanba-stir-fried TBC.

Calibrating contact parameters of typical rotary tillage components cutting soil based on different simulation methods

This report analyzes the problem of complex soil movement patterns under the action of coupled forces, such as tension and shear, in agricultural processes and aims to improve the accuracy of contact parameters used in discrete element simulation studies of rototiller-soil interactions. This study focuses on the soil of Shihezi cotton field in the 8th division of Xinjiang and investigates the rotating tiller roller as a soil-touching component of tillage machinery. A combination of simulations and physical testing is used. We perform angle of repose tests and use edge detection, fitting, and other image processing methods to automatically, quickly, and accurately detect the soil accumulation and angle calibration of the contact parameters with soil particles. Additionally, soil slip tests are conducted to calibrate the contact parameters between the soil and the rotary blades. Optimization is achieved based on orthogonal simulations and the Box-Behnken response surface method using physically measured values as the target. A regression model of the stacking angle and rolling friction angle is established to determine the optimal combination of simulation contact parameters: between soil and soil, the recovery coefficient is 0.402, static friction coefficient is 0.621, and rolling friction coefficient is 0.078; between soil contact parts and soil, the recovery coefficient is 0.508, static friction coefficient is 0.401, and rolling friction coefficient is 0.2. Furthermore, the calibration parameters are selected as contact parameters for the discrete element simulation. By combining the above two simulation methods to analyze and compare the simulation process of cutting soil from rototiller roller parts to rototiller single blade parts, we obtained the changes in energy, cutting resistance, and soil particle movement at different depths of the soil cutting process. Finally, the average cutting resistance was used as an index for validation in the field tests. The measured value is 0.96 kN and the error of the discrete element simulation is 13%. This demonstrates the validity of the calibrated contact parameters and the accuracy of the simulation, which can provide a theoretical reference and technical support for the study of the interaction mechanisms between of tillage equipment parts and soil, as well as the design and optimization of these interactions in the future.

Enhancement of herbicolin A production by integrated fermentation optimization and strain engineering in Pantoea agglomerans ZJU23

BackgroundThe lipopeptide herbicolin A (HA) secreted by the biocontrol agent Pantoea agglomerans ZJU23 is a promising antifungal drug to combat fungal pathogens by targeting lipid rafts, both in agricultural and clinical settings. Improvement of HA production would be of great significance in promoting its commercialization. This study aims to enhance the HA production in ZJU23 by combining fermentation optimization and strain engineering.ResultsBased on the results in the single-factor experiments, corn steep liquor, temperature and initial pH were identified as the significant affecting factors by the Plackett–Burman design. The fermentation medium and conditions were further optimized using the Box-Behnken response surface method, and the HA production of the wild type strain ZJU23 was improved from ~ 87 mg/mL in King’s B medium to ~ 211 mg/mL in HA induction (HAI) medium. A transposon library was constructed in ZJU23 to screen for mutants with higher HA production, and two transcriptional repressors for HA biosynthesis, LrhA and PurR, were identified. Disruption of the LrhA gene led to increased mRNA expression of HA biosynthetic genes, and subsequently improved about twofold HA production. Finally, the HA production reached ~ 471 mg/mL in the ΔLrhA mutant under optimized fermentation conditions, which is about 5.4 times higher than before (~ 87 mg/mL). The bacterial suspension of the ΔLrhA mutant fermented in HAI medium significantly enhanced its biocontrol efficacy against gray mold disease and Fusarium crown rot of wheat, showing equivalent control efficacies as the chemical fungicides used in this study. Furthermore, HA was effective against fungicide resistant Botrytis cinerea. Increased HA production substantially improved the control efficacy against gray mold disease caused by a pyrimethanil resistant strain.ConclusionsThis study reveals that the transcriptional repressor LrhA negatively regulates HA biosynthesis and the defined HAI medium is suitable for HA production. These findings provide an extended basis for large-scale production of HA and promote biofungicide development based on ZJU23 and HA in the future.Graphical