Microencapsulated Lactobacillus plantarum promotes intestinal development through gut colonization of layer chicks.

The effects of Lactobacillus plantarum in microencapsulation (LPM) on intestinal development in layer chicks were investigated in this study, as well as the colonization of L. plantarum in the gut. A total of 480 healthy Hy-Line Brown layer chicks at 0 d old were randomly divided into 4 groups (8 replicates each treatment), and the diets of these birds were supplemented with nothing (control), L. plantarum (0.02 g/kg feed; 109 CFU/kg feed), LPM (1.0 g/kg feed; 109 CFU/kg feed) and wall material of LPM (WM; 0.98 g/kg feed), respectively. Compared to control, LPM improved growth performance and intestinal development of layer chicks, evidenced by significantly increased body weight, average daily gain, average daily feed intake, villus height, villus height/crypt depth, as well as weight and length of the duodenum, jejunum and ileum (P < 0.05). These results could be attributed to the increased colonization of L. plantarum in the gut, which was verified by significant increases in lactic acid content, viable counts in chyme and mucosa (P < 0.05), as well as a visible rise in number of strains labeled with fluorescein isothiocyanate. Meanwhile, the relative abundances of Lactobacillus and Bifidobacterium significantly increased in response to microencapsulated L. plantarum supplementation (P < 0.05), accompanied by the significant up-regulation of colonization related genes (P < 0.05), encoding solute carrier family, monocarboxylate transporter, activin A receptor, succinate receptor and secretogranin II. To sum up, microencapsulated L. plantarum supplementation promoted intestinal development, which could be attributed to the enhancement of L. plantarum colonization in the intestine through the mutual assistance of Bifidobacterium and interactions with colonization related transmembrane proteins.

Preservation of the celiac branch of the vagus nerve reduces the incidence of postoperative diarrhea in gastric cancer: a cohort study.

BACKGROUND: To investigate the short-term and long-term outcomes of preserving the celiac branch of the vagus nerve during laparoscopic distal gastrectomy. METHODS: A total of 149 patients with prospective diagnosis of gastric cancer who underwent laparoscopic-assisted distal gastrectomy (LADG) combined with Billroth-II anastomosis and D2 lymph node dissection between 2017 and 2018 were retrospectively analyzed. The patients were divided into the preserved LADG group (P-LADG, n = 56) and the resected LADG group (R-LADG, n = 93) according to whether the vagus nerve celiac branch was preserved. We selected 56 patients (P-LADG, n = 56) with preservation of the celiac branch of the vagus nerve and 56 patients (R-LADG, n = 56) with removal of the celiac branch of the vagus nerve by propensity-matched score method. Postoperative nutritional status, weight change, short-term and long-term postoperative complications, and gallstone formation were evaluated in both groups at 5 years of postoperative follow-up. The status of residual gastritis and bile reflux was assessed endoscopically at 12 months postoperatively. RESULTS: The incidence of diarrhea at 5 years postoperatively was lower in the P-LADG group than in the R-LADG group (p < 0.05). In the multivariate logistic analysis, the removal of vagus nerve celiac branch was an independent risk factor for the occurrence of postoperative diarrhea (odds ratio = 3.389, 95% confidential interval = 1.143-10.049, p = 0.028). In the multivariate logistic analysis, the removal of vagus nerve celiac branch was an independent risk factor for the occurrence of postoperative diarrhea (odds ratio = 4.371, 95% confidential interval = 1.418-13.479, p = 0.010). CONCLUSIONS: Preservation of the celiac branch of the vagus nerve in LADG reduced the incidence of postoperative diarrhea postoperatively in gastric cancer. TRIAL REGISTRATION: This study was registered with the Ethics Committee of the First Affiliated Hospital of Dalian Medical University in 2014 under the registration number: LCKY2014-04(X).

Clinical study of the posterior gastric artery and the lymph nodes around it in patients with gastric cancer.

OBJECTIVES: This study aims to gather and analyze the anatomical characteristics of the posterior gastric artery (PGA), investigate the presence and metastasis of lymph nodes around the PGA in patients with gastric cancer. Additionally, the study aims to analyze the relationship between the PGA and its surrounding lymph nodes and the clinicopathological features of patients with gastric cancer. METHODS: This study consisted of a cross-sectional analysis of data from 52 patients with gastric cancer who underwent total or proximal gastrectomy at the Department of Gastrointestinal Surgery, First Affiliated Hospital of Dalian Medical University, between January 2020 and November 2022. Intraoperative exploration was performed to determine the presence of the PGA, and patients with the PGA were assessed for relevant anatomical characteristics, including the length of the PGA and the distance from the root of the PGA to the celiac trunk. Dissection of lymph nodes around the PGA was also performed. Statistical methods were employed to describe and analyze the data regarding the presence of the PGA, as well as the presence and metastasis of the lymph nodes around the PGA. Additionally, the study identified clinicopathological factors associated with these conditions. RESULTS: The PGA was identified in 39 (75.0%) out of 52 patients with gastric cancer, exhibiting a mean PGA length of 3.5 ± 0.8 cm and a mean distance from the root of the PGA to the celiac trunk of 6.7 ± 1.7 cm. Among the 39 patients who underwent dissection of lymph nodes around the PGA, 36 lymph nodes around the PGA were detected in 20 patients. Analysis of factors associated with the presence of lymph nodes around the PGA revealed a significant correlation with the macroscopic type of the tumor and the total number of dissected lymph nodes (P = 0.007 and P = 0.022, respectively), with a larger number of total dissected lymph nodes being an independent factor (OR = 1.105, 95%CI: 1.019-1.199, P = 0.016). Furthermore, analysis of risk factors for metastasis of the lymph nodes around the PGA demonstrated that the total number of metastatic lymph nodes, No.3 lymph node metastasis, and No.11 lymph node metastasis were associated with metastasis of the lymph nodes around the PGA (P = 0.043, P = 0.028, and P = 0.020, respectively). CONCLUSION: The PGA exhibits a high incidence. It is essential to carefully identify the PGA during procedures involving the PGA and consider appropriate preservation or disconnection of this vessel. The presence of lymph nodes around the PGA is not an isolated occurrence. Gastric cancer can result in metastasis of the lymph nodes around the PGA. Although the overall risk of metastasis of the lymph nodes around the PGA is low in patients with gastric cancer, it increases in the presence of conditions such as No.3 lymph node metastasis, No.11 lymph node metastasis, advanced tumor stage, and extensive metastases in other regional lymph nodes.

Role of microencapsulated Lactobacillus plantarum in alleviating intestinal inflammatory damage through promoting epithelial proliferation and differentiation in layer chicks.

The alleviating effects of Lactobacillus plantarum in microencapsulation (LPM) on lipopolysaccharide (LPS)-induced intestinal inflammatory injury were investigated in layer chicks. A total of 252 healthy Hy-Line Brown layer chicks were randomly divided into six groups. Birds were injected with saline or LPS except for the control, and the diets of birds subjected to LPS were supplemented with nothing, L. plantarum, LPM, and wall material of LPM, respectively. The viable counts of LPM reached 109 CFU/g, and the supplemental levels of L. plantarum, LPM, and WM were 0.02 g (109 CFU), 1.0 g, and 0.98 g, per kilogram feed, respectively. LPS administration caused intestinal damage in layer chicks, evidenced by increased proinflammatory factors accompanied by poor intestinal development and morphology (p < 0.05). LPM/LPS significantly increased body weight, small intestine weight and length, villus height, villus height/crypt depth, and mRNA relative expression of tight junction protein genes (p < 0.05) and performed better than free L. plantarum. These findings could be attributed to the significant increase in viable counts of L. plantarum in the small intestine (p < 0.05), as well as the enhanced levels of Actinobacteriota, Lactobacillaceae, and Lactobacillus in intestinal microbiota (p < 0.05). Such results could further significantly increase goblet and PCNA+ cell percentage (p < 0.05); the mRNA relative expressions of epithelial cell, fast-cycling stem cell, quiescent stem cell, endocrine cell, and Paneth cell; and goblet and proliferative cell marker genes, including E-cadherin, Lgr-5, Bmi-1, ChA, Lysozome, Mucin-2, and PCNA (p < 0.05). Furthermore, the mRNA relative expressions of key genes involved in epithelial cell proliferation, namely, c-Myc, Cyclin-1, Wnt-3, Lrp-5, and Olfm-4, exhibited significant upregulation compared with the LPS treatment, as well as the differentiating genes Notch-1 and Hes-1 (p < 0.05). To sum up, microencapsulated L. plantarum supplementation could alleviate intestinal injury in layer chicks induced by LPS by promoting the proliferation and differentiation of intestinal epithelial cells, which could be attributed to the increase in viable count of L. plantarum in the gut and optimization in intestinal microbial flora.

TiO2 Nanocontainers Coconstructed Using Polymers and Corrosion Inhibitors for Anticorrosion Reinforcement of Waterborne Epoxy Coatings.

Stimulus-responsive coatings can provide active corrosion protection in response to environmental changes, but they have not reached their anticipated application prospects because of the intricate preparation processes of hollow materials and methods for loading corrosion inhibitors. Herein, polyaniline molybdate corrosion inhibitor and polydopamine-wrapped titanium dioxide nanocontainers (named TiO2/PANI-MoO42-/PDA) are synthesized via a simple three-step electrostatic assembly technique. Introducing TiO2/PANI-MoO42-/PDA nanocontainers in smart waterborne epoxy (WEP) coatings affords the latter with high barriers and long-term corrosion protection. The successful deposition of each layer on the TiO2 nanocontainer surface was validated via Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. Release test results show that the molybdate corrosion inhibitor exhibits notable pH-responsive activity under acidic conditions and slow release in neutral environments, which improves the corrosion resistance of coatings. The addition of synthetic nanocontainers greatly improves the impermeability of WEP coatings. The charge transfer resistance of WEP/TiO2/PANI-MoO42-/PDA coatings is 1.79 × 1011 Ω cm2 after 30 day immersion in a 3.5 wt % NaCl solution, which is 3.32 × 105 times higher than that of WEP coatings. WEP/TiO2/PANI-MoO42-/PDA coatings remain uniform and reliable, even after 50 days of salt spray exposure. The excellent corrosion protection of WEP/TiO2/PANI-MoO42-/PDA coatings is attributed to (1) the enhanced dispersion and compatibility of PDA in the coating for nanocontainers, (2) the combination of phenolic hydroxyl groups of PDA and Fe, which inhibit corrosion activity on the exposed metal surface, and (3) the on-demand release of the MoO42- inhibitor, which provides sustained passivation protection. This work proposes a strategy to simplify the preparation of responsive long-term anticorrosion coatings and extend their service lives.

Effects of Lactobacillus Lactis Supplementation on Growth Performance, Hematological Parameters, Meat Quality and Intestinal Flora in Growing-Finishing Pigs.

OBJECTIVE: The study was conducted to assess the effect of supplementation with Lactobacillus lactis (LL) on growth performance, hematological parameters, meat quality and intestinal flora in pigs from growing until slaughter. METHODS: A total of 72 growing pigs (30.46 ± 3.08 kg) were randomly assigned to 3 groups (including 3 pens for each group, with 8 pigs in each pen). The three treatments comprised a basal diet (O-0) and two experimental diets supplemented for 14 weeks with 0.01% (O-100) and 0.03% (O-300) LL, respectively. RESULTS: The final body weights of the pigs in the O-100 and O-300 groups were significantly higher (p < 0.05) than those of the O-0 group. In the grower phase, the average daily weight gain (ADG) and average daily feed intake (ADFI) of pigs fed the O-300 diet were higher (p < 0.05) than those of pigs fed the O-0 diet during the grower phase. BUN and MDA were significantly higher (p < 0.05 for all) in the O-0 group than in the O-100 and O-300 groups during the grower phase. No difference (p > 0.05) was observed in the hematological parameters among the three groups during the finisher phase. Counts of LL in the stomach were significantly higher (p < 0.05) in the O-300 group than in the O-0 group. Counts of Escherichia coli in the jejunum were significantly higher (p < 0.05) in the O-0 group than in the O-300 group. Furthermore, the hardness, cohesiveness, gumminess and resilience of longissimus dorsi muscle collected from pigs fed the O-300 diet were higher (p < 0.01; p = 0.024; p = 0.003; p = 0.014, respectively) than those of tissue collected from pigs fed the O-0 diet. CONCLUSION: Dietary LL supplementation increased final body weight, increased ADG in the grower phase and enhanced meat quality.

Partially delocalized charge in crystalline Co-S-Se/NiOx nanocomposites for boosting electrocatalytic oxygen evolution.

Although reasonably specified and adjustable preparation of nanostructures with specific morphologies, ordered chemical compositions and electronic structures involving advanced energy chemistries is an important research area, high-efficiency, stable, and low-cost electrocatalysts for water splitting are greatly desirable and challenging. In this study, partially delocalized Co-S-Se ultra-thin nanosheets are obtained via a liquid-liquid interface-mediated strategy at an oil-water interface. These Co-S-Se ultra-thin nanosheets exhibit different-sized lamellar structures and have an average thickness of 0.83 nm. The ternary ultra-thin Co0.45S0.38Se0.17 nanosheets demonstrate excellent performance for the OER, accompanied by an overpotential of 290 mV (1.52 V vs. RHE) at 10 mA cm-2, and a Tafel slope of 74.5 mV dec-1. In the meantime, the catalyst recombined with a stoichiometry NiOx catalyst to form a composite interface, which also exhibited a good OER performance, with an overpotential of 260 mV at 10 mA cm-2 and a smaller Tafel slope of 53.9 mV dec-1. The nanosheets can rearrange the electronic density near the metal catalytic centers and increase the electron transfer. DFT calculations indicate that the partially delocalized charges can improve electrocatalytic performances, demonstrating modulated electroreduction properties. Due to the special atomic and electronic structure of the ternary transition metal alloy chalcogenide, the compound has great potential for energy storage, which will help in the rational design and synthesis of high-efficiency electrocatalysts.

Transcriptome analysis of thymic tissues from Chinese Partridge Shank chickens with or without Newcastle disease virus LaSota vaccine injection via high-throughput RNA sequencing.

The LaSota strain of Newcastle disease virus (NDV) is a commonly used vaccine to control Newcastle disease. However, improper immunization is a common reason for vaccine failure. Hence, it is imperative to thoroughly explore innate immunity-related molecular regulatory responses to the LaSota vaccine. In this text, 140 long non-coding RNAs (lncRNAs), 8 microRNAs (miRNAs), and 1514 mRNAs were identified to be differentially expressed by RNA sequencing analysis in the thymic tissues of Chinese Partridge Shank chickens after LaSota vaccine inoculation. Moreover, 70 dysregulated genes related to innate immunity were identified based on GO, Reactome pathway, and InnateDB annotations and differential expression analysis. Additionally, dysregulated lncRNAs and innate immunity-related mRNAs that could interact with dysregulated miRNAs were identified based on bioinformatics prediction analysis via the miRanda software and differential expression analysis. Among these transcripts, expression patterns of five lncRNAs, seven miRNAs, and six mRNAs were further examined by RT-qPCR assay. Both RNA-seq and RT-qPCR outcomes showed that 10 transcripts (MSTRG.22689.1, ENSGALT00000065826, ENSGALT00000059336, ENSGALT00000060887, gga-miR-6575-5p, gga-miR-6631-5p, gga-miR-1727, paraoxonase 2 (PON2), mitogen-activated protein kinase 10, and cystic fibrosis transmembrane conductance regulator (CFTR) were highly expressed, and 4 transcripts (MSTRG.188121.10, gga-miR-6655-5p, gga-miR-6548-3p, and matrix metallopeptidase 9 (MMP9) were low expressed after NDV infection. Additionally, two potential competing endogenous RNA networks (ENSGALT00000060887/gga-miR-6575-5p/PON2 or MSTRG.188121.10/gga-miR-6631-5p/MMP9) and some co-expression axes (ENSGALT00000065826/gga-miR-6631-5p, MSTRG.188121.10/gga-miR-6575-5p, MSTRG.188121.10/CFTR, ENSGALT00000060887/MMP9) were identified based on RT-qPCR and co-expression analyses. In conclusion, we identified multiple dysregulated lncRNAs, miRNAs, and mRNAs after LaSota infection and some potential regulatory networks for these dysregulated transcripts.

Calcium-binding protein 39 overexpression promotes macrophages from 'M1' into 'M2' phenotype and improves chondrocyte damage in osteoarthritis by activating the AMP-activated protein kinase/sirtuin 1 axis.

Osteoarthritis (OA) is a degenerative joint disease that affects cartilage and its peripheral tissues. Up-regulation of Calcium-binding protein 39 (CAB39) has a significant protective effect on osteoblasts, but the role and related molecular mechanisms of CAB39 in OA have not yet been reported. CAB39 overexpression and knockdown models were set up in chondrocytes (ATDC5) and macrophages (RAW264.7). The OA cell model was induced in ATDC5 cells with IL-1ß (10 ng/mL). Cell viability was tested by the cell counting kit-8 assay, apoptosis was checked by flow cytometry. Western blot was applied for checking the expression of MMP3, MMP13, Aggrecan, the AMPK/Sirt-1 pathway, apoptosis-related proteins (Bax, Bcl-2, and Caspase-3), and macrophage phenotypic markers (CD86, iNOS, CD206, and Arg1). An OA model was constructed in mice, and CAB39 overexpression plasmids were administered to the knee cavity of the OA model mice. As a result, CAB39 was down-regulated in IL-1ß-treated chondrocytes and OA mice. Overexpressing CAB39 enhanced ATDC5 cell viability and choked IL-1ß-mediated apoptosis. Overexpression of CAB39 boosted the polarization of macrophages from M1-phenotype into M2 phenotype. In addition, overexpressing CAB39 facilitated the AMPK/Sirt-1 pathway activation, and AMPK inhibitors reversed the protective effect of CAB39 overexpression on chondrocytes. Moreover, CAB39 exhibited anti-inflammatory effects in OA mice by activating the AMPK/Sirt-1 pathway. Collectively, overexpressing CAB39 heightened macrophages' M2 polarization and declined chondrocyte injury in OA by activating the AMPK/Sirt-1 pathway.Abbreviations AMPK: AMP-activated protein kinaseArg1: arginase 1Bax: Bcl-2-associated X proteinBcl-2: B-cell lymphoma-2CAB39: Calcium-binding protein 39CM: Conditioned mediumDMM: destabilization of the medial meniscusECM: extracellular matrixELISA: enzyme-linked immunosorbent assayFCM: Flow cytometryIL-1ß: interleukin-1ßIL-4: interleukin-4IL-6: interleukin-6IL-10: interleukin-10IFN - γ: Interferon-gammaIHC: ImmunohistochemistryiNOS: Inducible nitric oxide synthaseLKB1: liver kinase B1MMP3: Matrix metalloproteinase3MMP13:Matrix metalloproteinase13NF-κB: NF-kappaBOA: OsteoarthritisqRT-PCR: Quantitative reverse transcription-polymerase chain reactionRT: room temperatureSirt-1: sirtuin 1STRAD: STE20-related adaptor alphaWB: Western blot.

The influence of prior arthroscopy on outcomes of primary total lower extremity arthroplasty: A systematic review and meta-analysis.

PURPOSE: The primary purpose of this systematic review and meta-analysis was to investigate the impact of prior arthroscopy on postoperative revisions, complications, and other clinical outcomes after conversion total lower extremity arthroplasty. METHODS: Two individual researchers conducted the platform searches on the Embase, PubMed, Cochrane Central, and Google Scholar electronic databases from inception to June 02, 2021. We identified cohort trials that compared the outcomes of patients who underwent primary THA or TKA in the prior arthroscopy or control groups. The primary outcome was revision, and secondary outcomes included reoperation, patient-reported outcomes, and postoperative complications. A modified version of the Downs and Black tool was used to assess the methodological quality of the non-randomized cohort studies. RESULTS: Of the 23 included studies with 319946 cases, 18 were matched retrospectively and five were non-matched retrospectively. Methodological quality was high in ten studies and moderate in thirteen studies. Our analysis demonstrated that TKA or THA patients with prior arthroscopy were associated with an increased risk of revision, reoperation, infection, and aseptic loosening. THA patients with prior arthroscopy were also associated with an increased risk of dislocation. Furthermore, there were no significant intergroup differences in periprosthetic fracture, range of motion, Harris Hip Score, or Knee Society Score. CONCLUSION: Arthroscopy performed before total lower extremity arthroplasty substantially increased the revision, reoperation, infection, and aseptic loosening rates. THA patients with prior arthroscopy were also associated with an increased risk of dislocation. Patients should be counseled on the potential increased risks associated with conversion total lower extremity arthroplasty after prior arthroscopy. Further research is needed to better characterize these findings.

Effect of Powder on Tribological and Electrochemical Properties of Nylon 66 and Ultra-High Molecular Weight Polyethylene in Water and Seawater Environments.

Polymer materials are used increasingly in marine machinery and equipment; their tribological properties and effect on the water environment have garnered significant attention. We investigate the effect of water or seawater environment containing powder on tribology and electrochemistry of polymer materials. A friction test involving nylon 66 (PA66) and an ultrahigh molecular weight polyethylene (UHMWPE) pin-disc (aluminum alloy) is performed in seawater or water with/without polymer powder, and the solution is analyzed electrochemically. The results show that the tribological properties of the UHMWPE improved by adding the powder to the solution, whereas the PA66 powder demonstrates abrasive wear in a pure water environment, which elucidates that the synergistic effect of powder and seawater on UHMWPE reduces the wear, and the synergistic effect of pure water and powder aggravates the wear. The results of electrochemical experiments show that after adding powder in the friction and wear tests, the powder can protect the pin by forming a physical barrier on the surface and reducing corrosion, and the changes are more obvious in seawater with powder in it. Through electrochemical and tribological experiments, the synergistic effect of solution environment and powder was proved.

Thymic transcriptome analysis after Newcastle disease virus inoculation in chickens and the influence of host small RNAs on NDV replication.

Newcastle disease (ND), caused by virulent Newcastle disease virus (NDV), is a contagious viral disease affecting various birds and poultry worldwide. In this project, differentially expressed (DE) circRNAs, miRNAs and mRNAs were identified by high-throughput RNA sequencing (RNA-Seq) in chicken thymus at 24, 48, 72 or 96 h post LaSota NDV vaccine injection versus pre-inoculation group. The vital terms or pathways enriched by vaccine-influenced genes were tested through KEGG and GO analysis. DE genes implicated in innate immunity were preliminarily screened out through GO, InnateDB and Reactome Pathway databases. The interaction networks of DE innate immune genes were established by STRING website. Considering the high expression of gga-miR-6631-5p across all the four time points, DE circRNAs or mRNAs with the possibility to bind to gga-miR-6631-5p were screened out. Among DE genes that had the probability to interact with gga-miR-6631-5p, 7 genes were found to be related to innate immunity. Furthermore, gga-miR-6631-5p promoted LaSota NDV replication by targeting insulin induced gene 1 (INSIG1) in DF-1 chicken fibroblast cells. Taken together, our data provided the comprehensive information about molecular responses to NDV LaSota vaccine in Chinese Partridge Shank Chickens and elucidated the vital roles of gga-miR-6631-5p/INSIG1 axis in LaSota NDV replication.

Molecular dynamics simulation of shock-induced microscopic bubble collapse.

Shock waves and micro-jets generated during the process of bubble collapse lead to cavitation damage on the surface of materials in hydraulic machinery equipment parts, which is attention. However, research on the dynamics of bubble collapse is still unclear. In this work, molecular dynamics (MD) simulations are used to study the compression and collapse processes of microscopic bubbles under the impact of different velocities for water molecules. The velocities of the shock wave, time of bubble collapse and shock pressure of collapse were obtained. Results showed that higher the impact velocity, shorter is the time of bubble collapse and the higher velocity of the micro-jet. After the bubble collapse, the micro-jet will form secondary water hammer shocks and a greater shock pressure. The water structure appears to undergo a phase change (ice-VII structure) when the velocity of water molecules is 1.0 km s-1. The shock induces the bubble collapse and the micro-jet significantly increases the chemical activity of water molecules; the degree of ionization of water molecules increases with the shock velocity. In addition, the Hugoniot curve of the shock velocity obtained by molecular dynamics simulations are in good agreement with the experimental data.

Molecular dynamics simulation of microscopic friction mechanisms of amorphous polyethylene.

Determining the nature of the microscopic mechanism of tribological properties by experimental methods for a polymer material surface/interface in the sliding friction process is a challenge. Molecular dynamics simulations were conducted by sliding a rigid indenter over the amorphous polyethylene. The results show that the friction is mainly composed of plough force and adhesion force. The average friction of adhesive contact is greater than that of frictionless contact because of the adhesion effect. The difference of average friction between adhesive contact and frictionless contact increases with increasing indentation depth because of the plough force effect. The elastic deformation of amorphous polyethylene in the cohesive zone is related to van der Waals interaction energy, whereas the plastic deformation was mainly dominated by bond angle energy and dihedral energy of the molecular chain for amorphous polyethylene. Molecular chains of amorphous polyethylene extend along the sliding direction and agglomerate along the indentation direction. The flexibility of the molecular chains increases with the increase of temperature and facilitates the molecular chains returning more easily to their original state.

Design and Development of Lubricating Material Database and Research on Performance Prediction Method of Machine Learning.

Long developing period and cumbersome evaluation for the lubricating materials performance seriously jeopardize the successful development and application of any database system in tribological field. Such major setback can be solved effectively by implementing approaches with high throughput calculation. However, it often involves with vast number of output files, which are computed on the basis of first principle computation, having different data format from that of their experimental counterparts. Commonly, the input, storage and management of first principle calculation files and their individually test counterparts, implementing fast query and display in the database, adding to the use of physical parameters, as predicted with the performance estimated by first principle approach, may solve such setbacks. Investigation is thus performed for establishing database website specifically for lubricating materials, which satisfies both data: (i) as calculated on the basis of first principles and (ii) as obtained by practical experiment. It further explores preliminarily the likely relationship between calculated physical parameters of lubricating oil and its respectively tribological and anti-oxidative performance as predicted by lubricant machine learning model. Success of the method facilitates in instructing the obtainment of optimal design, preparation and application for any new lubricating material so that accomplishment of high performance is possible.

Comparison of oxidation resistance of UHMWPE and POM in H2O2 solution from ReaxFF reactive molecular dynamics simulations.

The oxidation mechanism of ultra-high-molecular-weight polyethylene (UHMWPE) and polyoxymethylene (POM) in hydrogen peroxide solution was investigated by molecular dynamics (MD) simulations via reactive force field (ReaxFF) method. MD results from ReaxFF suggested that UHMWPE provided better antioxidation activity at high temperature (>373 K) than its POM counterpart in the same concentration of hydrogen peroxide solution. Furthermore, POM was relatively more susceptible to erosion and swelling because of the infiltration of H2O2 solution. Calculations of the diffusion coefficient at different temperatures permit further understanding of the chemical phenomena involved in the level of oxidation in the course of MD simulations. Results of the simulations are generally consistent with the previous experimental available in literature. The simulations also provide new insights into understanding the mechanism resulting oxidation products among the interested polymers.