Publications by authors named "Mingyuan Lu"

9 Publications

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Dietary oregano essential oil supplementation improves intestinal functions and alters gut microbiota in late-phase laying hens.

J Anim Sci Biotechnol 2021 Jul 6;12(1):72. Epub 2021 Jul 6.

Laboratory of Quality & Safety Risk Assessment for Animal Products on Feed Hazards (Beijing) of the Ministry of Agriculture & Rural Affairs, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South St., Haidian District, Beijing, 10081, China.

Background: Dietary essential oil (EO) supplementation can exert favorable effects on gut health in broilers. However, it is unknown whether EO could improve intestinal functions, consequently beneficial for egg performance and quality in late-phase laying hens. This study was aimed to investigate the potential effects of EO on production performance, egg quality, intestinal health and ileal microbiota of hens in the late phase of production. A total of 288 60-week-old Hy-line Brown laying hens were randomly divided into 4 groups and fed a basal diet (control) or basal diets supplemented with oregano EO at 100, 200 and 400 mg/kg (EO100, EO200 and EO400).

Results: Dietary EO supplementation resulted in a quadratic decrease (P < 0.05) in feed conversion ratio with lower (P < 0.05) feed conversion ratio in EO200 group than the control during weeks 9-12 and 1-12 of the trial. Compared to the control, EO addition resulted in higher (P < 0.05) eggshell thickness at the end of week. 4, 8 and 12 and higher (P < 0.05) chymotrypsin activity. There was a quadratic elevation (P < 0.05) in ileal chymotrypsin and lipase activity, along with a linear increase in villus height to crypt depth ratio. Quadratic declines (P < 0.05) in mRNA expression of IL-1β, TNF-α, IFN-γ and TLR-4, concurrent with a linear and quadratic increase (P < 0.05) in ZO-1 expression were identified in the ileum with EO addition. These favorable effects were maximized at medium dosage (200 mg/kg) of EO addition and intestinal microbial composition in the control and EO200 groups were assessed. Dietary EO addition increased (P < 0.05) the abundances of Burkholderiales, Actinobacteria, Bifidobacteriales, Enterococcaceae and Bacillaceae, whereas decreased Shigella abundance in the ileum.

Conclusions: Dietary EO addition could enhance digestive enzyme activity, improve gut morphology, epithelial barrier functions and modulate mucosal immune status by altering microbial composition, thus favoring feed efficiency and eggshell quality of late-phase laying hens.
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http://dx.doi.org/10.1186/s40104-021-00600-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8259136PMC
July 2021

Purification, characterization, and chemical modification of Bacillus velezensis SN-14 fibrinolytic enzyme.

Int J Biol Macromol 2021 Apr 23;177:601-609. Epub 2021 Feb 23.

Key Laboratory of Agricultural and Animal Products Store & Processing of Guizhou Province, Guizhou University, Guiyang 550025, PR China; College of Liquor and Food Engineering, Guizhou University, Guiyang 550025, PR China.

Fermented bean foods are a crucial source of fibrinolytic enzymes. The presented study aimed to purify, characterize, and chemically modify Bacillus velezensis SN-14 fibrinolytic enzyme. The fibrinolytic enzyme was purified using CTAB/isooctane/hexyl alcohol/n-butyl alcohol reverse micellar system, and the purified enzyme was chemically modified to improve its enzymatic activity and stability. Enzyme activity recovery and the purification fold for this enzyme were 44.5 ± 1.9% and 4.93 ± 0.05 fold, respectively. SDS-PAGE results showed that the molecular weight of the purified fibrinolytic enzyme was around 28 kDa. Besides, the optimum temperature and pH of the purified fibrinolytic enzyme were 37 °C and 8-9, respectively. Fe, mPEG5000, and pepsin were used for chemical modification and for improving the activity and stability of the purified enzyme. Thermal and acid-base stability of chemically modified enzymes increased significantly, whereas enzymatic activity increased by 7.3 times. After 30 d of frozen storage, the modified enzyme's activity was remarkably lower (33.2%) than the unmodified enzyme (60.6%). The current study on B. velezensis SN-14 fibrinolytic enzyme and chemical modification method using Fe, mPEG5000, and pepsin provide a reference for developing fibrinolytic drugs and foods.
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http://dx.doi.org/10.1016/j.ijbiomac.2021.02.167DOI Listing
April 2021

TiB Nanowhisker Reinforced Titanium Matrix Composite with Improved Hardness for Biomedical Applications.

Nanomaterials (Basel) 2020 Dec 10;10(12). Epub 2020 Dec 10.

School of Mechanical and Mining Engineering, The University of Queensland, Brisbane 4072, Australia.

Titanium and its alloys have been employed in the biomedical industry as implants and show promise for more broad applications because of their excellent mechanical properties and low density. However, high cost, poor wear properties, low hardness and associated side effects caused by leaching of alloy elements in some titanium alloys has been the bottleneck to their wide application. TiB reinforcement has shown promise as both a surface coating for Ti implants and also as a composite reinforcement phase. In this study, a low-cost TiB-reinforced alpha titanium matrix composite (TMC) is developed. The composite microstructure includes ultrahigh aspect ratio TiB nanowhiskers with a length up to 23 μm and aspect ratio of 400 and a low average Ti grain size. TiB nanowhiskers are formed in situ by the reaction between Ti and BN nanopowder. The TMC exhibited hardness of above 10.4 GPa, elastic modulus above 165 GPa and hardness to Young's modulus ratio of 0.062 representing 304%, 170% and 180% increases in hardness, modulus and hardness to modulus ratio, respectively, when compared to commercially pure titanium. The TiB nanowhisker-reinforced TMC has good biocompatibility and shows excellent mechanical properties for biomedical implant applications.
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http://dx.doi.org/10.3390/nano10122480DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7764548PMC
December 2020

Isolation of Bacillus spp. with High Fibrinolytic Activity and Performance Evaluation in Fermented Douchi.

J Food Prot 2021 Apr;84(4):717-727

Key Laboratory of Agricultural and Animal Products Storation & Processing of Guizhou Province (ORCID: https://orcid.org/0000-0002-3523-0872 [L.H.]).

Abstract: Fibrinolytic enzymes are effective and highly safe in treating cardiovascular and cerebrovascular diseases. Therefore, screening fibrinolytic enzyme-producing microbial strains with excellent fermentation performance is of great value to industrial applications. The fibrin plate method was used in screening strains with high yields of fibrinolytic enzymes from different fermented food products, and the screened strains were preliminarily identified using molecular biology. Then, the strains were used for solid-state fermentation of soybeans. Moreover, the fermentation product douchi was subjected to fibrinolytic activity measurement, sensory evaluation, and biogenic amine content determination. The fermentation performance of each strain was comprehensively evaluated through principal component analysis. Finally, the target strain was identified based on strain morphology, physiological and biochemical characteristics, 16S rDNA sequence, and phylogenetic analysis results. A total of 15 Bacillus species with high fibrinolysin activity were selected. Their fibrinolytic enzyme-producing activity levels were higher than 5,500 IU/g. Through molecular biology analysis, we found 4 strains of Bacillus subtilis, 10 strains of Bacillus amyloliquefaciens, and 1 strain of Bacillus velezensis. The principal component analysis results showed that SN-14 had the best fermentation performance and reduced the accumulation of histamine and total amine, the fibrinolytic activity of fermented douchi reached 5,920.5 ± 107.7 IU/g, and the sensory score was 4.6 ± 0.3 (out of 5 points). Finally, the combined results of physiological and biochemical analyses showed SN-14 was Bacillus velezensis. The high-yield fibrinolytic and excellent fermentation performance strain Bacillus velezensis SN-14 has potential industrial application.

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http://dx.doi.org/10.4315/JFP-20-307DOI Listing
April 2021

Deformation behavior of porous PHBV scaffold in compression: A finite element analysis study.

J Mech Behav Biomed Mater 2019 08 17;96:1-8. Epub 2019 Apr 17.

School of Mechanical and Mining Engineering, The University of Queensland, QLD, 4072, Australia.

Macroscopic mechanical properties of porous PHBV bone TE scaffolds have been well studied. However, their mechanical behavior at microscopic level has yet to be explored. In this study, the micro-mechanical behavior of a PHBV bone scaffold under compression was investigated using a numerical method that combines micro-computed tomography (μ-CT) and finite element analysis (FEA). It was found that the use of a linear-elastic model resulted in an overestimation of the stiffness of the scaffold, whereas a more realistic estimation of the scaffold's deformation behavior was obtained by utilizing a bilinear material model. The onset of plastic deformation occurred in the very early stage of loading resulting in significantly reduced stiffness of the scaffold. The non-uniform and arbitrary microstructure of the scaffold led to a heterogeneous stress distribution within the porous construct, which was subjected to a mixture of compressive and tensile stresses. Nevertheless, the resultant stress contours showed that the scaffold experienced primarily elastic deformation when it was loaded up to 0.003 strain, while localized plastic deformation occurred at sharp corners and necked regions of the micro-struts. The scaffold expanded slightly in the horizontal direction as it was compressed and the change in geometries of pores within the scaffold was insignificant. The proposed method provides a valuable tool to study the localized mechanical behavior of bone scaffolds in micrometer scale with arbitrary porous architecture. This approach could prove highly useful for guiding the fabrication of scaffolds that have anatomy specific mechanical properties and porous architecture.
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http://dx.doi.org/10.1016/j.jmbbm.2019.04.030DOI Listing
August 2019

Akermanite reinforced PHBV scaffolds manufactured using selective laser sintering.

J Biomed Mater Res B Appl Biomater 2019 11 22;107(8):2596-2610. Epub 2019 Mar 22.

School of Mechanical and Mining Engineering, The University of Queensland, Queensland, Australia.

Scaffold assisted tissue engineering presents a promising approach to repair diseased and fractured bone. For successful bone repair, scaffolds need to be made of biomaterials that degrade with time and promote osteogenesis. Compared to the commonly used ß-tricalcium phosphate scaffolds, Akermanite (AKM) scaffolds were found to degrade faster and promote more osteogenesis. The objective of this study is to synthesize AKM micro and nanoparticle reinforced poly(3-hydroxybutyrate-co-3-hydroxyvalerate; PHBV) composite scaffolds using selective laser sintering (SLS). The synthesized composite scaffolds had an interconnected porous microstructure (61-64% relative porosity), large specific surface areas (31.1-64.2 mm ) and pore sizes ranging from 303 to 366 and 279 to 357 μm in the normal and lateral direction, respectively, which are suitable for bone tissue repair. The observed hydrophilic nature of the scaffolds and the swift water uptake was due to the introduction of numerous carboxylic acid groups on the scaffold surface after SLS, circumventing the need for postprocessing. For the composite scaffolds, large amounts of AKM particles were exposed on the skeleton surface, which is a requirement for cell attachment. In addition, the particles embedded inside the skeleton helped to significantly reinforce the scaffold structure. The compressive strength and modulus of the composite scaffolds were up to 7.4 and 103 MPa, respectively, which are 149 and 197% of that of the pure PHBV scaffolds. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2596-2610, 2019.
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http://dx.doi.org/10.1002/jbm.b.34349DOI Listing
November 2019

In vitro degradation of a unique porous PHBV scaffold manufactured using selective laser sintering.

J Biomed Mater Res A 2019 01 25;107(1):154-162. Epub 2018 Oct 25.

School of Mechanical and Mining Engineering, The University of Queensland, Queensland, 4072, Australia.

Biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) scaffolds have shown great promise for bone tissue engineering applications. The investigation of their hydrolytic degradation is thus essential to understand the effect of hydrolysis on the complex biodegradation behavior of PHBV scaffolds. In this study, we investigated the degradation behavior of high molecular weight PHBV scaffolds manufactured using selective laser sintering (SLS) without using predesigned porous architectures. The manufactured scaffolds have high specific surface areas with great water-uptake abilities. After an incubation of 6 weeks in phosphate-buffered saline solution, the structural integrity of the scaffolds was unaffected. However, a significant decrease in molecular weight ranging from 39% to 46% was found. The measured weight loss was negligible, but their compressive modulus and strength both decreased, likely due to water plasticization. These findings suggest that hydrolytic degradation of PHBV by means of bulk degradation was the predominant mechanism, attributed to their excellent water absorptivity. Overall, the PHBV scaffolds manufactured using SLS exhibited adequate mechanical properties and satisfactory structural integrity after incubation. As a result, the scaffolds have great potential as candidates for bone repair in clinical practice. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 154-162, 2019.
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http://dx.doi.org/10.1002/jbm.a.36543DOI Listing
January 2019

The poisoning effect of PbO and PbCl on CeO-TiO catalyst for selective catalytic reduction of NO with NH.

J Colloid Interface Sci 2018 Oct 22;528:82-91. Epub 2018 May 22.

College of Pipeline and Civil Engineering, China University of Petroleum, 66 Changjiang West Road, Qingdao 266580, China.

The poisoning effect of PbO and PbCl on CeO-TiO catalyst for selective catalytic reduction of NO with NH was investigated and compared. Both Pb species could deactivate the CeO-TiO catalyst and PbO had a stronger poisoning effect than PbCl. From the characterization results of BET, XRD, XPS, NH-TPD and H-TPR, it was concluded that the more serious deactivation by PbO could be ascribed to smaller BET surface area, fewer surface Ce and chemisorbed oxygen, stronger interaction between PbO and CeO-TiO catalyst, lower redox properties and surface acidity. The in situ DRIFT study results revealed that the NH-SCR reaction over CeO-TiO catalyst was governed by both E-R and L-H mechanisms, which wasn't changed over the Pb-poisoned samples. The greater loss of Brønsted acid sites attributed to fewer surface Ce and more serious inhibition of NO oxidation to NO due to fewer surface chemisorbed oxygen were two key factors responsible for more serious deactivation by PbO. Furthermore, the presence of Pb species inhibited the NH adsorption on the Lewis acid sites, aggravating the deactivation of CeO-TiO catalyst.
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http://dx.doi.org/10.1016/j.jcis.2018.05.061DOI Listing
October 2018

Synthesis, microstructure, and mechanical behaviour of a unique porous PHBV scaffold manufactured using selective laser sintering.

J Mech Behav Biomed Mater 2018 08 26;84:151-160. Epub 2018 May 26.

School of Mechanical and Mining Engineering, The University of Queensland, St Lucia, QLD 4072, Australia. Electronic address:

Selective Laser Sintering (SLS) is a promising technique for manufacturing bio-polymer scaffolds used in bone tissue engineering applications. Conventional scaffolds made using SLS have complex engineered architectures to introduce adequate porosity and pore interconnectivity. This study presents an alternative approach to manufacture scaffolds via SLS without using pre-designed architectures. In this work, a SLS process was developed for fabricating interconnected porous biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) scaffolds with large surface areas and relative porosities of up to 80%. These characteristics provide great potential to enhance cell attachment inside the scaffolds. The scaffold microstructure was dependent on the laser energy density (LED) during the SLS process. An increase in LED led to scaffolds with higher relative densities, stronger inter-layer connections, and a reduced quantity of residual powder trapped inside the pores. An increase in relative density from 20.3% to 41.1% resulted in a higher maximum compressive modulus and strength of 36.4 MPa and 6.7 MPa, respectively.
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http://dx.doi.org/10.1016/j.jmbbm.2018.05.007DOI Listing
August 2018
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