Quantification of peptide components in cinobufacini injection and toad skin by ultra-high-performance liquid chromatography/triple quadrupole mass spectrometry.

Cinobufacini injection is commonly used in the clinical treatment of tumors and hepatitis B, but the quality is uneven. Currently, the main focus of its quality assessment is on steroids and alkaloids. Based on a previous study, we screened four peptides with high reproducibility, responsiveness, and specificity. This research was the first to develop an ultra-high-performance liquid chromatography/triple quadrupole mass spectrometry approach for evaluating the quality of cinobufacini preparations from the peptide perspective. In this study, we have identified 230 peptides in cinobufacini injection by Q-Exactive mass spectrometry, which contains species-specific peptides. Then, we used ultra-high-performance liquid chromatography/triple quadrupole mass spectrometry to establish a quantitative method for species-specific peptides and carried out method validation. The result revealed that four peptides were linear in a specific range, and had great reproducibility, accuracy, and stability. Eventually, we evaluated the quality of eight batches of cinobufacini injections and 26 batches of toad skins using the total content of target peptides as the criterion. The outcomes demonstrated that the quality of cinobufacini injection is generally stable and the toad skin from Shandong is of the best quality. In conclusion, the quantitative approach that focuses on peptides will offer innovative perspectives on assessing the quality of cinobufacini preparations.

Optimization design of the sound absorbing structure of double-layer porous metal material with air layer based on genetic algorithm.

An acoustic absorption structure of a double-layer porous metal material with air layers is proposed. The Johnson-Champoux-Allard (JCA) model combined with the transfer matrix method (TMM) was used to establish the theoretical calculation model of the sound absorption coefficient (SAC). Meanwhile, the SAC between 500 and 6300 Hz were measured with an impedance tube. The errors between the theoretical and experimental values were compared to illustrate the good predictability of the theoretical model within the inverse estimations of the transport properties. The effects of the material placement order, material thickness, and cavity depth on the sound absorption performance from 200 to 5000 Hz were analyzed using the theoretical model. Further, a multi-objective function genetic algorithm was used to optimize the porous material's thickness and SAC to obtain an acoustic structure with a smaller thickness and higher sound absorption. A series of optimal solutions were obtained for acoustic structures with a total thickness of less than 70 mm. When the total thickness of the foam metal was 33.57 mm, the average SAC reached 0.853, which was significantly lower than the total thickness of the previous experiments. The multi-objective function genetic algorithm can provide a reliable solution for the optimal design of most sound-absorbing structures.

Identification of peptides of cinobufacini by gel filter chromatography and peptidomics.

Aqueous extract of toad skin (named as Cinobufacini or Huachansu) provides plentiful sources of bioactive peptides that remain undetected and unidentified. High-resolution mass spectrometry-based peptidomics platforms have developed into a major approach to the discovery of natural peptides, with data-dependent acquisition modes providing a wealth of peptide profiling information. In this study, we used a gel- and HLB (a solid phase extraction cartridge)-based two-dimensional separation and purification system and nano-liquid chromatography-tandem mass spectrometry-based peptidomic studies with homology matching for the identification of peptides from Cinobufacini. We evaluated 232 multi-charged peptides and found several specific peptides, some of which were validated by target parallel reaction monitoring mode. These peptides are the first to be identified in Cinobufacini and are completely different from ones identified in toad venom. So, this mapping provides key peptide information for the quality control of Bufo bufo gargarizans skin and its preparation.

Proteomics and UHPLC-DAD-Q/Orbitrap-MS used to identify impurities in andrographolide.

INTRODUCTION: Andrographolide active pharmaceutical ingredient (API) is a semidiurnal diterpene lactone with significant antipyretic, antiviral, anti-inflammatory and anticancer activities. A large amount of andrographolide API could only be obtained by extraction from Andrographis paniculata. Therefore, there may be related compounds, plant proteins and other impurities in andrographolide API. OBJECTIVE: In order to improve the safety of andrographolide related preparations, it was necessary to clarify the impurities and improve the quality standard of andrographolide API. METHODS: The related compounds were identified by ultrahigh-performance liquid chromatography with diode-array detector quadrupole Orbitrap mass spectrometry (UHPLC-DAD-Q/Orbitrap-MS), and the residual proteins were determined by ultrafiltration combined with proteomics. The proteomics method included protein extraction, content determination, digestion, desalination and nanoscale liquid chromatography coupled to tandem mass spectrometry (nano LC-MS/MS) analysis. Then, MS results were compared with Andrographis paniculata protein database by Peaks Studio. RESULTS: The results showed that 32 related compounds were putatively identified, of which 30 impurities were identified for the first time. Seven residual proteins together with 11 highly suspected proteins were uniquely identified, including the T1UNN5_ANDPA protein with the highest intensity. CONCLUSIONS: This study will provide useful information on the composition of andrographolide API, which is important for the quality control and clinical safety assurance of API and related prescriptions. Reasonable guidance will also be provided on the necessity of ultrafiltration in the production process of related injections.

[Research strategies and methods for precious animal medicine substitutes].

Animal medicine is a large category of Chinese medicinecommonly used in clinical practice and has important scientific and therapeutic value. Animal medicine isscarcer than herbal medicine. In recent years, with the vigorous development of traditional Chinese medicine(TCM),the contradiction between the increasing industrial demand andsupply of scarce and even endangered medicinal animals has become increasingly prominent. The continuous lack of medicinal animal resources affects the clinical demandandalso causes serious damage to the ecological environment. Only relying on artificial breeding is not enough to alleviate the current condition of depletion. In the face of this dilemma, it is a major challenge for the current industrial development to protect animal resources and meet clinical and industrial needs with "available medicines". The application of substitutes for animal medicines isthe key focus to alleviate this problem, and it is also the key scientific issue to be solved urgently in the modernization of TCM. This paper summarizedand reviewedthe history, current situation, strategies, and methods of animal medicinesubstitution and put forward the point of view of "similar chemical characteristics, similar efficacy, and higher safety" to provide references for scientific substitution and resource protection of rare animals.

High Resolution Mass Profile of Bufadienolides and Peptides Combing with Anti-Tumor Cell Screening and Multivariate Analysis for the Quality Evaluation of Bufonis Venenum.

In order to evaluate the quality of Bufonis Venenum commercial herbs, a three-step qualitative and quantitative research study was performed. Firstly, we tried to identify small molecules and peptides in Bufonis Venenum using pre-fractionation chromatography and high-resolution mass spectrometry. The database search of the small molecules and peptides of Bufonis Venenum revealed that the dried venom consisted of free/conjugated-type bufadienolides and peptides with a mass range of 0.4-2 kDa. Secondly, we used partial least squares (PLS) multivariate statistical analysis to screen bufadienolides markers (VIP > 1.5) responsible for the anti-tumor cell activity of Bufonis Venenum, including 21 identified bufadienolides and 7 unknown compounds. It is noticeable that these bufadienolide markers could not be recognized by traditional HPLC-UV based spectrum-effect relationship analysis (correlation coefficient ranging from -0.24 to 0.40). Finally, we proposed a weight coefficient-based corrected total contents of 9 bufadienolides as a quality evaluation indicator, which had good correlation with inhibitory effects on tumor cells of commercial Bufonis Venenum. The correlation coefficient increased from 0.4 to 0.6. Thus, our pre-fractionation chromatography and mass spectrometry strategy had significant advancement over the traditional spectrum-effect relationship method for chemical marker identification. These results could be crucial and helpful in the development of a quality evaluation method that could reflect the pharmacological activity of Bufonis Venenum.

An in vitro metabolomics approach to identify hepatotoxicity biomarkers in human L02 liver cells treated with pekinenal, a natural compound.

An in vitro cell metabolomics study was performed on human L02 liver cells to investigate the toxic biomarkers of pekinenal from the herb Euphorbia pekinensis Rupr. Pekinenal significantly induced L02 cell damage, which was characterised by necrosis and apoptosis. Metabolomics combined with data pattern recognition showed that pekinenal significantly altered the profiles of more than 1299 endogenous metabolites with variable importance in the projection (VIP) > 1. Further, screening correlation coefficients between the intensities of all metabolites and the extent of L02 cell damage (MTT) identified 12 biomarker hits: ten were downregulated and two were upregulated. Among these hits, LysoPC(18:1(9Z)/(11Z)), PC(22:0/15:0) and PC(20:1(11Z)/14:1(9Z)) were disordered, implying the initiation of inflammation and cell damage. Several fatty acids (FAs) (3-hydroxytetradecanedioic acid, pivaloylcarnitine and eicosapentaenoyl ethanolamide) decreased due to fatty acid oxidation. Dihydroceramide and Cer(d18:0/14:0) were also altered and are associated with apoptosis. Additional examination of the levels of intracellular reactive oxygen species (ROS) and two eicosanoids (PGE2, PGF2α) in the cell supernatant confirmed the fatty acid oxidation and arachidonic acid metabolism pathways, respectively. In summary, cell metabolomics is a highly efficient approach for identifying toxic biomarkers and helping understand toxicity mechanisms and predict herb-induced liver injury.

Metabolomics method based on ultra high performance liquid chromatography with time-of-flight mass spectrometry to analyze toxins in fresh and dried toad venom.

Drying is a critical step to prolong the storage time in natural medicine processing but it changes the chemical characteristics of the product. In this study, research was performed to characterize the metabolomic changes in toad venom induced by vacuum-drying at 60°C and air-drying at room temperature by ultra high performance liquid chromatography coupled with pattern recognition approaches. In total 52 metabolites, down-regulated or up-regulated, were identified as potential chemical markers. Compared with fresh toad venom, vacuum-drying at 60°C succeeded in raising the conjugated-type bufadienolide content significantly, while the content of free-type bufadienolides were slightly reduced. On the other hand, toad venom air-dried at room temperature presented a relatively low amount of bufadienolides compared with fresh venom. For example, the content of several known anti-tumor components (gamabufotalin, bufotalin, cinobufagin, etc.) were significantly reduced. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide bioassay further showed that venom air-dried at room temperature had weaker anti-tumor activity on human hepatocellular carcinoma SMMC-7721 proliferation in vitro than samples vacuum-dried at 60°C. These results showed that the great metabolomic changes of toad venom occurred during the drying process, suggesting that a proper drying procedure is important for sustaining the chemical quality of natural medicines.

Phosphoproteomic network analysis in the sea urchin Strongylocentrotus purpuratus reveals new candidates in egg activation.

Fertilization triggers a dynamic symphony of molecular transformations induced by a rapid rise in intracellular calcium. Most prominent are surface alterations, metabolic activation, cytoskeletal reorganization, and cell-cycle reentry. While the activation process appears to be broadly evolutionarily conserved, and protein phosphorylation is known to play a key role, the signaling networks mediating the response to fertilization are not well described. To address this gap, we performed a time course phosphoproteomic analysis of egg activation in the sea urchin Strongylocentrotus purpuratus, a system that offers biochemical tractability coupled with exquisite synchronicity. By coupling large-scale phosphopeptide enrichment with unbiased quantitative MS, we identified striking changes in global phosphoprotein patterns at 2- and 5-min postfertilization as compared to unfertilized eggs. Overall, we mapped 8796 distinct phosphosite modifications on 2833 phosphoproteins, of which 15% were differentially regulated in early egg activation. Activated kinases were identified by phosphosite mapping, while enrichment analyses revealed conserved signaling cascades not previously associated with egg activation. This work represents the most comprehensive study of signaling associated with egg activation to date, suggesting novel mechanisms that can be experimentally tested and providing a valuable resource for the broader research community. All MS data have been deposited in the ProteomeXchange with identifier PXD002239 (http://proteomecentral.proteomexchange.org/dataset/PXD002239).

[Comparison of chemical composition between fresh and processed Bufonis Venenum by UPLC-TQ-MS].

Toad venom is the Bufo bufo gargarizans or B. melanostictus after the ears of the gland secretion, used in the treatment of various cancers in recent years. Research shows that the main anti-tumor components in bufadienolide. Bufadienolide have free type structure and conjunct type structure. To identify and clarify the difference between bufogenin and bufotoxin contained in Bufonis Venenum, which was from B. bufo gargarizans, an UPLC-TQ-MS method has been established. UPLC-TQ-MS method was used to identify and quantify the major bufadienolides in Bufonis Venenum. UPLC-TQ-MS assay with positive ion mode was performed on a Waters ACQUITY UPLC BEH C, (2.1 mm x 100 mm, 1.7 µm) with the mobile phase consisting of 0. 1% aqueous formic and acidacetonitrile in gradient elution at a flow rate of 0.4 mL · min⁻¹ and the column temperature was set at 35 °C. By comparing their retention time and high resolution mass data of Bufonis Venenum extracts, 37 effective components were primarily identified by MS/MS analysis in positive ion mode. Twenty-six of them were free-type bufadienolides (bufogenin), 11 of them were conjugated bufadienolides. There were significant differences in the main composition between fresh and processed Bufonis Venenum. The study found that the chemical composition of toad venom through great changes after processing, conjunct type content is much less, free type content as well change.

Exploring peptides from toad venom for source identification by LC-MS/MS using MRM method.

Toad venom is a traditional Chinese medicine (TCM) with various sources and wide-ranging preparations. Previous quality assessment studies primarily concentrated on small molecular compounds like toad dienolactones and indole alkaloids, studies on macromolecular peptides and proteins as quality assessment standards remained at the qualitative stage, lacking the development of practical and convenient quantitative methods. In this study, to explore the peptides from toad venom as a new method for identifying and evaluating its source, a complete scan of the water extract of peptides from toad venom was conducted using HPLC-Quadrupole Time-of-Flight Mass Spectrometer (Q-TOF) 5600, leading to the identification of peptides based on mass spectrometry data. Subsequently, HPLC- Quadrupole-Linear Ion Trap Mass Spectrometer (Q-Trap) 5500 employing Multiple Reaction Monitoring (MRM) mode was utilized to quantitatively analyze peptides in various sources of toad venom, followed by Partial Least Squares Discriminant Analysis (PLS-DA) to further analyze the data and evaluate the effectiveness. This study highlights the importance of exploring macromolecular substance in natural products research and provides a foundation for further studies on toad venom.

Homotherapy-for-heteropathy of Bupleurum Chinense DC.-Scutellaria baicalensis Georgi in treating depression and colorectal cancer: A network pharmacology and animal model approach.

ETHNOPHARMACOLOGICAL RELEVANCE: Bupleurum chinense DC.-Scutellaria baicalensis Georgi (BS) is a classic drug pair that has good clinical effects on depression and many tumors. However, the concurrent targeting mechanism of how the aforementioned drug pair is valid in the two distinct diseases, has not been clarified yet. AIM OF THE STUDY: The components of BS were detected by LC-MS, combined with network pharmacology to explore the active ingredients and common targeting mechanism of its multi-pathway regulation of BS in treating depression and CRC, and to validate the dual effects of BS using the CUMS mice model and orthotopic transplantation tumor mice model of CRC. RESULTS: Twenty-nine components were screened, 84 common gene targets were obteined, and the top 5 key targets including STAT3, PIK3R1, PIK3CA, AKT1, IL-6 were identified by PPI network. GO and KEGG analyses revealed that PI3K/AKT and JAK/STAT signaling pathways might play a crucial role of BS in regulating depression and CRC. BS significantly modulated CUMS-induced depressive-like behavior, attenuated neuronal damage, and reduced serum EPI and NE levels in CUMS model mice. BS improved the pathological histological changes of solid tumors and liver tissues and inhibited solid tumors and liver metastases in tumor-bearing mice. BS significantly decreased the proteins' expression of IL-6, p-JAK2, p-STAT3, p-PI3K, p-AKT1 in hippocampal tissues and solid tumors, and regulated the levels of IL-2, IL-6 and IL-10 in serum of two models of mice. CONCLUSION: BS can exert dual antidepressant and anti-CRC effects by inhibiting the expression of IL-6/JAK2/STAT3 and PI3K/AKT pathway proteins and regulating the release of inflammatory cytokines.

Arenobufagin enhances T-cell anti-tumor immunity in colorectal cancer by modulating HSP90ß accessibility.

BACKGROUND: Colorectal cancer (CRC) is a significant public health issue, ranking as one of the predominant cancer types globally in terms of incidence. Intriguingly, Arenobufagin (Are), a compound extracted from toad venom, has demonstrated the potential to inhibit tumor growth effectively. PURPOSE: This study aimed to explore Are's molecular targets and unravel its antitumor mechanism in CRC. Specifically, we were interested in its impact on immune checkpoint modulation and correlations with HSP90ß-STAT3-PD-L1 axis activity. METHODS: We investigated the in vivo antitumor effects of Are by constructing a colorectalcancer subcutaneous xenograft mouse model. Subsequently, we employed single-cell multi-omics technology to study the potential mechanism by which Are inhibits CRC. Utilizing target-responsive accessibility profiling (TRAP) technology, we identified heatshock protein 90ß (HSP90ß) as the direct target of Are, and confirmed this through a microscale thermophoresis experiment (MST). Further downstream mechanisms were explored through techniques such as co-immunoprecipitation, Western blotting, qPCR, and immunofluorescence. Concurrently, we arrived at the same research conclusion at the organoid level by co-cultivating with immune cells. RESULTS: We observed that Are inhibits PD-Ll expression in CRC tumor xenografts at low concentrations. Moreover, TRAP revealed that HSP90ß's accessibility significantly decreased upon Are binding. We demonstrated a decrease in the activity of the HSP90ß-STAT3-PD-Ll axis following low-concentration Are treatment in vivo. The PDO analysis showed improved enrichment of lymphocytes, particularly T cells, on the PDOs following Are treatment. CONCLUSION: Contrary to previous research focusing on the direct cytotoxicity of Are towards tumor cells, our findings indicate that it can also inhibit tumor growth at lower concentrations through the modulation of immune checkpoints. This study unveils a novel anti-tumor mechanism of Are and stimulates contemplation on the dose-response relationship of natural products, which is beneficial for the clinical translational application of Are.

Red Meat Consumption and Cancer Risk: A Systematic Analysis of Global Data.

The association between red meat consumption and cancer risk remains a controversy. In this study, we systematically collected and analyzed global data (from Our World in Data and Global Cancer Observatory) to investigate this association for the first time. Our results confirmed significant positive associations between red meat consumption (RMC) and overall cancer incidence (0.798, p < 0.001), or colorectal cancer incidence (0.625, p < 0.001). Several previously unreported cancer types linked to RMC were also unveiled. Gross domestic product (GDP) per capita were found to have an impact on this association. However, even after controlling it, RMC remained significantly associated with cancer incidence (0.463, p < 0.001; 0.592, p < 0.001). Meanwhile, after controlling GDP per capita, the correlation coefficients between white meat consumption and overall cancer incidence were found to be much lower and insignificant, at 0.089 (p = 0.288) for poultry consumption and at -0.055 (p = 0.514) for seafood and fish consumption. Notably, an interesting comparison was performed between changes of colorectal cancer incidence and RMC in many countries and regions. A lag of 15-20 years was found, implying causality between RMC and cancer risk. Our findings will contribute to the development of more rational meat consumption concept.

Discovery of estrogen receptor α modulators from natural compounds in Si-Wu-Tang series decoctions using estrogen-responsive MCF-7 breast cancer cells.

The binding between the estrogen receptor α (ER-α) and a variety of compounds in traditional Chinese formulae, Si-Wu-Tang (SWT) series decoctions, was studied using a stably-transfected human breast cancer cell line (MVLN). In 38 compounds tested from SWT series decoctions, the estrogen-like activity of 22 compounds was above 60% in 20 µg mL(-1). Furthermore, theoretical affinity of these compounds was certificated using the functional virtual screen of ER-α modulators by FlexX-Pharm. The accuracy of functional virtual screening of ER-α modulators could reach to 77.27%. The results showed that some compounds, such as organic acids and flavones in SWT series decoctions could be used as selective estrogen receptor modulators (SERMs) and could be selected for further development as potential agents for estrogen related diseases.

Protective effect of taurine on cardiotoxicity of the bufadienolides derived from toad (Bufo bufo gargarizans Canto) venom in guinea-pigs in vivo and in vitro.

In China, toad venom is an anti-inflammatory agent used in small doses for the treatment of various types of inflammation. Bufadienolides are cardioactive steroids responsible for the anti-inflammatory actions of toad venom. We studied the protective effect of taurine on the cardiotoxicity of bufadienolides in guinea-pigs. Bufadienolides (8 mg/kg) caused arrhythmias, cardiac dysfunction and death in guinea-pigs. Pretreatment with taurine (150, 300 mg/kg) significantly prevented bufadienolide-induced cardiotoxicity and reduced the mortality in vivo. Taurine markedly increased the cumulative doses of bufadienolides and resibufogenin required for lethal arrhythmia in ex vivo isolated guinea-pig heart. Taurine did not compromise the anti-inflammatory activity of the bufadienolides on concanavalin-A-stimulated proliferation of guinea-pig splenocytes in vitro. These data indicate that taurine can prevent bufadienolide-induced cardiotoxicity and could be a novel antidote in combination with bufadienolide therapy.

[Molecular docking of chlorogenic acid, 3,4-di-O-caffeoylquinic acid and 3,5-di-O-caffeoylquinic acid with human serum albumin].

OBJECTIVE: To investigate the mechanism of binding of human serum albumin (HSA) with potential sensitinogen, including chlorogenic acid and two isochlorogenic acids (3,4-di-O-caffeoylquinic acid and 3,5-di-O-caffeoylquinic acid). METHODS: By using the docking algorithm of computer-aided molecular design and the Molegro Virtual Docker, the crystal structures of HSA with warfarin and diazepam (Protein Data Bank ID: 2BXD and 2BXF) were selected as molecular docking receptors of HSA sites I and II. According to docking scores, key residues and H-bond, the molecular docking mode was selected and confirmed. The molecular docking of chlorogenic acid and two isochlorogenic acids on sites I and II was compared based on the above design. RESULTS: The results from molecular docking indicated that chlorogenic acid, 3,4-di-O-caffeoylquinic acid and 3,5-di-O-caffeoylquinic acid could bind to HSA site I by high affinity scores of -112.3, -155.3 and -153.1, respectively. They could bind to site II on HSA by high affinity scores of -101.7, -138.5 and -133.4, respectively. In site I, two isochlorogenic acids interacted with the key apolar side-chains of Leu238 and Ala291 by higher affinity scores than chlorogenic acid. Furthermore, the H-bonds of isochlorogenic acids with polar residues inside the pocket and at the entrance of the pocket were different from chlorogenic acid. Moreover, the second coffee acyl of isochlorogenic acid occupied the right-hand apolar compartment in the pocket of HSA site I. In site I, the second coffee acyl of isochlorogenic acid formed the H-bonds with polar side-chains, which contributed isochlorogenic acid to binding with site II of HSA. CONCLUSION: The isochlorogenic acids with two coffee acyls have higher binding abilities with HSA than chlorogenic acid with one coffee acyl, suggesting that isochlorogenic acids binding with HSA may be sensitinogen.

The mechanisms of ferroptosis and its role in alzheimer's disease.

Alzheimer's disease (AD) accounts for two-thirds of all dementia cases, affecting 50 million people worldwide. Only four of the more than 100 AD drugs developed thus far have successfully improved AD symptoms. Furthermore, these improvements are only temporary, as no treatment can stop or reverse AD progression. A growing number of recent studies have demonstrated that iron-dependent programmed cell death, known as ferroptosis, contributes to AD-mediated nerve cell death. The ferroptosis pathways within nerve cells include iron homeostasis regulation, cystine/glutamate (Glu) reverse transporter (system xc-), glutathione (GSH)/glutathione peroxidase 4 (GPX4), and lipid peroxidation. In the regulation pathway of AD iron homeostasis, abnormal iron uptake, excretion and storage in nerve cells lead to increased intracellular free iron and Fenton reactions. Furthermore, decreased Glu transporter expression leads to Glu accumulation outside nerve cells, resulting in the inhibition of the system xc- pathway. GSH depletion causes abnormalities in GPX4, leading to excessive accumulation of lipid peroxides. Alterations in these specific pathways and amino acid metabolism eventually lead to ferroptosis. This review explores the connection between AD and the ferroptosis signaling pathways and amino acid metabolism, potentially informing future AD diagnosis and treatment methodologies.

A virtual laboratory based on full-field crystal plasticity simulation to characterize the multiscale mechanical properties of AHSS.

In this work, we proposed a virtual laboratory based on full-field crystal plasticity (CP) simulation to track plastic anisotropy and to calibrate yield functions for multiphase metals. The virtual laboratory, minimally, only requires easily accessible EBSD data for constructing the highly-resolved microstructural representative volume element and macroscopic flow stress data for identifying the micromechanical parameters of constituent phases. An inverse simulation method based on a global optimization scheme was developed to identify the CP parameters, and a nonlinear least-squares method was employed to calibrate yield functions. Mechanical tests of advanced high strength steel sheet under various loading conditions were conducted to validate the virtual laboratory. Three well-known yield functions, the quadratic Hill48 and non-quadratic Yld91 and Yld2004-18p yield functions, were selected as the validation benchmarks. All the studied functions, calibrated by numerous stress points of arbitrary loading conditions, successfully captured both the deformation and strength anisotropies. The full-field CP modeling correlated well the microscopic deformation mechanism and plastic heterogeneity with the macromechanical behavior of the sheet. The proposed virtual laboratory, which is readily extended with physically based CP models, could be a versatile tool to explore and predict the mechanical property and plastic anisotropy of advanced multiphase materials.

Prediction of the Sound Absorption Coefficient of Three-Layer Aluminum Foam by Hybrid Neural Network Optimization Algorithm.

The combination of multilayer aluminum foam can have high sound absorption coefficients (SAC) at low and medium frequencies, and predicting its absorption coefficient can help the optimal structural design. In this study, a hybrid EO-GRNN model was proposed for predicting the sound absorption coefficient of the three-layer composite structure of the aluminum foam. The generalized regression neural network (GRNN) model was used to predict the sound absorption coefficient of three-layer composite structural aluminum foam due to its outstanding nonlinear problem-handling capability. An equilibrium optimization (EO) algorithm was used to determine the parameters in the neuronal network. The prediction results show that this method has good accuracy and high precision. The calculation result shows that this proposed hybrid model outperforms the single GRNN model, the GRNN model optimized by PSO (PSO-GRNN), and the GRNN model optimized by FOA(FOA-GRNN). The prediction results are expressed in terms of root mean square error (RMSE), absolute error, and relative error, and this method performs well with an average RMSE of only 0.011.