A sequential macrophage activation strategy for bone regeneration: A micro/nano strontium-releasing composite scaffold loaded with lipopolysaccharide.

Effective tissue repair relies on the orchestration of different macrophage phenotypes, both the M2 phenotype (promotes tissue repair) and M1 phenotype (pro-inflammatory) deserve attention. In this study, we propose a sequential immune activation strategy to mediate bone regeneration, by loading lipopolysaccharide (LPS) onto the surface of a strontium (Sr) ions -contained composite scaffold, which was fabricated by combining Sr-doped micro/nano-hydroxyapatite (HA) and dual degradable matrices of polycaprolactone (PCL) and poly (lactic-co-glycolic acid) (PLGA). Our strategy involves the sequential release of LPS to promote macrophage homing and induce the expression of the pro-inflammatory M1 phenotype, followed by the release of Sr ions to suppress inflammation. In vitro and in vivo experiments demonstrated that, the appropriate pro-inflammatory effects at the initial stage of implantation, along with the anti-inflammatory effects at the later stage, as well as the structural stability of the scaffolds conferred by the composition, can synergistically promote the regeneration and repair of bone defects.

Effectiveness and safety of auricular acupuncture on adjuvant analgesia in patients with total knee arthroplasty: a randomized sham-controlled trial.

Objective: This study aimed to evaluate the effectiveness and safety of auricular acupuncture (AA) on postoperative analgesia, the degree of postoperative nausea, and the effect of inflammation after total knee arthroplasty (TKA). Methods: This was a single-center, placebo-controlled, randomized clinical trial. In total, 96 patients were randomly divided into an AA group with an indwelling intradermal needle (n = 48) and a sham auricular acupuncture (SAA) group with a non-penetrating placebo needle (n = 48). Intra-spinal anesthesia was adopted in both groups during surgery, and an epidural analgesic pump was implanted after surgery for 48 h. The primary outcome was the post-surgery visual analog score (VAS) of resting and movement states (at 6, 12 h and 1, 2, 3, 5, and 7 days). The secondary outcomes included additional doses of analgesic injection during the treatment, C-reactive protein (CRP) levels, erythrocyte sedimentation rate (ESR), and white blood cell (WBC) count on the 1st, 3rd, and 7th day after the operation, nausea on the 1st, 2nd, and 3rd day after the operation, the Hospital for Special Surgery Knee Score (HSS) on the 2nd and 12th week after the operation, and adverse events. Results: The VAS in the AA group at 6 h, 12 h, 2, 3, and 5 days after surgery were lower than those of the SAA group (p < 0.05). Among the secondary outcomes, the total dose of additional analgesic injection after surgery in the AA group was lower than that in the SAA group (p < 0.05). The serum CRP on the 1st day after operation in the AA group was lower than that in the SAA group (p < 0.05). The degree of nausea on 2nd day after surgery in the AA group was lower than that in the SAA group (p < 0.05). There was no significant difference in other outcomes (p > 0.05). Conclusion: In this study, AA was shown to be an effective and safe complementary and alternative therapy for pain relief after TKA, which was able to reduce the total postoperative dose of additional painkillers, decrease serum CRP 1 day after surgery, and improve the degree of postoperative nausea. Clinical trial registration: www.chictr.org.cn, ChiCTR2100054403.

Preparation of Co-Ni-Ce/TiC alloy coatings by double-pulse under a sulfamic acid system and a process mechanism study.

To enhance the protective ability of copper crystallizers and extend their service life, this study explores the use of double pulse co-deposition under a sulfamic acid system to create protective coatings such as Co-Ni. The hardness test and friction wear analysis compare Co-Ni, Co-Ni-Ce, and Co-Ni-Ce/TiC coatings, revealing that the Co-Ni-Ce/TiC coating exhibits the most outstanding protective performance. SEM and XRD techniques are employed to characterize the three protective coatings, demonstrating that the incorporation of rare-earth cerium and nanoparticles improves the coating morphology and modifies their crystalline phase structure. Furthermore, cyclic voltammetry tests on the plating solutions of the three protective coatings indicate that the addition of Ce3+ and nanoparticles influences the deposition potentials. The deposition of Co2+ and Ni2+ follows a two-step, two-electron process, while the deposition of Ce3+ follows a one-step, three-electron process. It is observed that the deposition of all three ions is irreversible. To gain further insights into the nucleation mechanism of Ce3+, a chronoamperometry test is conducted, revealing that the nucleation of Ce3+ is a transient process controlled by diffusion.

M2 macrophage-derived exosome-functionalized topological scaffolds regulate the foreign body response and the coupling of angio/osteoclasto/osteogenesis.

Designing scaffolds that can regulate the innate immune response and promote vascularized bone regeneration holds promise for bone tissue engineering. Herein, electrospun scaffolds that combined physical and biological cues were fabricated by anchoring reparative M2 macrophage-derived exosomes onto topological pore structured nanofibrous scaffolds. The topological pore structure of the fiber and the immobilization of exosomes increased the nanoscale roughness and hydrophilicity of the fibrous scaffold. In vitro cell experiments showed that exosomes could be internalized by target cells to promote cell migration, tube formation, osteogenic differentiation, and anti-inflammatory macrophage polarization. The activation of fibrosis, angiogenesis, and macrophage was elucidated during the exosome-functionalized fibrous scaffold-mediated foreign body response (FBR) in subcutaneous implantation in mice. The exosome-functionalized nanofibrous scaffolds also enhanced vascularized bone formation in a critical-sized rat cranial bone defect model. Importantly, histological analysis revealed that the biofunctional scaffolds regulated the coupling effect of angiogenesis, osteoclastogenesis, and osteogenesis by stimulating type H vessel formation. This study elaborated on the complex processes within the cell microenvironment niche during fibrous scaffold-mediated FBR and vascularized bone regeneration to guide the design of implants or devices used in orthopedics and maxillofacial surgery. STATEMENT OF SIGNIFICANCE: How to design scaffold materials that can regulate the local immune niche and truly achieve functional vascularized bone regeneration still remain an open question. Here, combining physical and biological cues, we proposed new insight to cell-free and growth factor-free therapy, anchoring reparative M2 macrophage-derived exosomes onto topological pore structured nanofibrous scaffolds. The exosomes functionalized-scaffold system mitigated foreign body response, including excessive fibrosis, tumor-like vascularization, and macrophage activation. Importantly, the biofunctional scaffolds regulated the coupling effect of angiogenesis, osteoclastogenesis, and osteogenesis by stimulating type H vessel formation.

A rapid and efficient Agrobacterium-mediated transient transformation system in grape berries.

Transient transformation is extremely useful for rapid in vivo assessment of gene function, especially for fruit-related genes. Grape berry, while an important fruit crop, is recalcitrant to transient transformation, due to the high turgor pressure in its mesocarp cells that limits the ability of Agrobacterium to penetrate into the tissue. It is urgent to establish a simple transient transformation system for rapid analysis of gene function. In this study, different injection methods, grape genotypes, and developmental stages were tested in order to develop a rapid and efficient Agrobacterium-mediated transient transformation methodology for grape berries. Two injection methods, namely punch injection and direct injection, were evaluated using the ß-glucuronidase (GUS) gene and by x-gluc tissue staining and 4-methylumbelliferyl-ß-D-glucuronide fluorescence analysis. The results indicated that there were no significant differences on transformation effects between the two methods, but the latter was more suitable because of its simplicity and convenience. Six grape cultivars ('Hanxiangmi', 'Moldova', 'Zijixin', 'Jumeigui', 'Shine-Muscat', and 'A17') were tested for transient transformation. 'Hanxiangmi', 'Moldova', and 'Zijixin' grape berries were not suitable for agroinfiltration due to frequently fruit cracking, browning, and formation of scar skin. The fruit integrity rates of 'Jumeigui', 'Shine-Muscat', and 'A17' berries were all above 80%, and GUS activity was detected in the berries of the three cultivars 3-14 days after injection with the Agrobacterium culture, while higher GUS activities were observed in the 'Jumeigui' berries. The levels of GUS activity in injected berries at 7-8 weeks after full blooming (WAFB) were more than twice at 6 WAFB. In subsequent assays, the over-expression of MYB transcription factor VvMYB44 via transient transformation accelerated the anthocyanin accumulation and fruit coloring through raising the expression levels of VvLAR1, VvUFGT, VvLDOX, VvANS, and VvDFR, which verified the effectiveness of this transformation system. These experiments finally identified the reliable grape cultivars and suitable operational approach for transient transformation and further indicated that this Agrobacterium-mediated transient transformation system was efficient and suitable for the elucidation of gene function in grape berries.

Jujube Witches' Broom Phytoplasma Effector Zaofeng3, a Homologous Effector of SAP54, Induces Abnormal Floral Organ Development and Shoot Proliferation.

Plant-pathogenic phytoplasmas secrete specific virulence proteins into a host plant to modulate plant function for their own benefit. Identification of phytoplasmal effectors is a key step toward clarifying the pathogenic mechanisms of phytoplasma. In this study, Zaofeng3, also known as secreted jujube witches' broom phytoplasma protein 3 (SJP3), was a homologous effector of SAP54 and induced a variety of abnormal phenotypes, such as phyllody, malformed floral organs, witches' broom, and dwarfism in Arabidopsis thaliana. Zaofeng3 can also induce small leaves, dwarfism, and witches' broom in Ziziphus jujuba. Further experiments showed that the three complete α-helix domains predicted in Zaofeng3 were essential for induction of disease symptoms in jujube. Yeast two-hybrid library screening showed that Zaofeng3 mainly interacts with proteins involved in flower morphogenesis and shoot proliferation. Bimolecular fluorescence complementation assays confirmed that Zaofeng3 interacted with these proteins in the whole cell. Overexpression of zaofeng3 in jujube shoot significantly altered the expression patterns of ZjMADS19, ZjMADS47, ZjMADS48, ZjMADS77, and ZjTCP7, suggesting that overexpressing zaofeng3 might induce floral organ malformation and witches' broom by altering the expression of the transcriptional factors involved in jujube morphogenesis.

Biodegradable Polyurethane Scaffolds in Regeneration Therapy: Characterization and In Vivo Real-Time Degradation Monitoring by Grafted Fluorescent Tracer.

There is an urgent need to assess material degradation in situ and in real time for their promising application in regeneration therapy. However, traditional monitoring methods in vitro cannot always profile the complicated behavior in vivo. This study designed and synthesized a new biodegradable polyurethane (PU-P) scaffold with polycaprolactone glycol, isophorone diisocyanate, and l-lysine ethyl ester dihydrochloride. To monitor the degradation process of PU-P, calcein was introduced into the backbone (PU-5) as a chromophore tracing in different sites of the body and undegradable fluorescent scaffold (CPU-5) as the control group. Both PU-P and PU-5 can be enzymatically degraded, and the degradation products are molecularly small and biosafe. Meanwhile, by virtue of calcein anchoring with urethane, polymer chains of PU-5 have maintained the conformational stability and extended the system conjugation, raising a structure-induced emission effect that successfully achieved a significant enhancement in the fluorescence intensity better than pristine calcein. Evidently, unlike the weak fluorescent response of CPU-5, PU-5 and its degradation can be clearly imaged and monitored in real time after implantation in the subcutaneous tissue of nude mice. Meanwhile, the in situ osteogeneration has also been promoted after the two degradable scaffolds have been implanted in the rabbit femoral condyles and degraded with time. To sum up, the strategy of underpinning tracers into degradable polymer chains provides a possible and effective way for real-time monitoring of the degradation process of implants in vivo.

Analysis of histopathology and changes of major cytokines in the lesions caused by Mycoplasma ovipneumoniae infection.

BACKGROUND: Mycoplasma ovipneumoniae (M. ovipneumoniae) is one of the main pathogens of sheep pneumonia, causing a series of clinical symptoms, such as depression, anorexia, hyperthermia, cough, dyspnea, and tract secretions. In recent years, the prevalence of M. ovipneumoniae pneumonia has become increasingly serious in sheep farms in Ningxia, China, leading to the death of sheep, and causing significant economic losses. In this study, the pathological organs infected by M. ovipneumoniae were collected to observe histopathological change, to determine the tissue localization of M. ovipneumoniae, and to analyze the cytokine changes, which lays a basis for the diagnosis and pathogenesis of M. ovipneumoniae disease. RESULTS: In this study, M. ovipneumoniae was detected in 97 of 105 samples collected from 13 large-scale sheep farms for nucleic acid by PCR. One representative isolate per farm was isolated from 13 farms. The lesions caused by M. ovipneumoniae were mainly in the trachea, bronchus, and lung, including necrosis of tracheal mucosal epithelial cells, disintegration of some epithelial cells, edema of mucosal lamina propria, with inflammatory cell infiltration, cytoplasmic vacuolization of epithelial cells of bronchial mucosa, massive infiltration of inflammatory cells in the alveolar space of lung, necrosis and hyperplasia of alveolar epithelial cells. Immunohistochemical analysis showed that the proportion of M. ovipneumoniae positive area in the lung was the largest, followed by that in the bronchus and trachea. Compared to healthy animals, diseased animals exhibited up-regulated gene expression levels of IL-1ß, IL-6, and NF-κB in the trachea, bronchus, and lungs. In contrast, the expression of IL-10, IL-12, and IFN-γ was primarily limited to the trachea and bronchus. The expression of IL-1ß showed differential patterns across different lung regions, with variations observed among lung lobes. Additionally, other cytokines consistently showed significant up-regulation specifically in the bronchus. CONCLUSIONS: M. ovipneumoniae is primarily found in the lungs of infected individuals. NF-κB, an essential transcription factor, is involved in the regulation of IL-1ß transcription. IL-12 may enhance the cytotoxic function of natural killer cells during M. ovipneumoniae infection. Those findings demonstrate the distinct expression profiles of cytokines in various anatomical sites throughout disease progression, suggesting the potential role of bronchial tissue as a major site of immune response.

Repair of soft magnetic properties of wasted silicon steel and Co7Fe3 alloy deposition mechanism.

In order to repair the soft magnetic properties of wasted silicon steel, a theoretical process of co-depositing Co-Fe soft magnetic alloy on the surface of wasted silicon steel is proposed. The results show that the co-deposited Co-Fe alloy coatings can serve to repair the soft magnetic properties of wasted silicon as detected by the vibrating sample magnetometer, and the alloy coatings with Co7Fe3 as the main phase structure can provide surface protection for silicon steel. Subsequently, the mechanism of co-deposited Co-Fe alloys was investigated, and it was concluded that Co2+ and Fe2+ undergo a one-step two-electron co-deposition reaction, as studied using cyclic voltammetry. The chronoamperometric analysis and its fitting results indicated that the deposition of Co2+ and Fe2+ was a diffusion-controlled transient nucleation process, and the AC impedance indicated that higher voltages were favorable for the deposition of Co-Fe alloys but were accompanied by hydrogen precipitation reactions.

Mycoplasma synoviae lipid-associated membrane proteins identification and expression changes when exposed to chicken cells.

Mycoplasma synoviae is a significant cause of respiratory disease and synovitis among chickens, and has an adverse economic impact on broiler breeding efforts. The present study was designed to develop a systematic understanding of the role that M. synoviae lipid-associated membrane proteins (LAMPs) may play in the virulence of this pathogen. Bioinformatics tools were used to identify 146 predicted membrane proteins and lipoproteins in the M. synoviae proteome. Then, Triton X-114 was used to extract LAMPs that were subsequently identified via LC-MS/MS. This approach enabled the detection of potential LAMPs, and the top 200 most abundant proteins detected using this strategy were subject to further analysis. M. synoviae cells (100 MOI) were exposed to chicken fibroblasts (DF-1) and macrophages (HD-11) in a 1:1 mixed culture. Analysis of LAMP transcripts identified 72 up-regulated LAMP genes which were analyzed in depth by bioinformatics. GO analysis revealed these genes to be enriched in the nucleotide binding, sulfur amino acid transmembrane transporter activity, tRNA binding, rRNA modification, and transition metal ion transport pathways. Moreover, KEGG enrichment analysis suggested that these genes were enriched in the biosynthesis of secondary metabolites, carbon metabolism, glycolysis/gluconeogenesis, and nitrogen metabolism pathways.

Sparking potential over 1200 V by a falling water droplet.

Hydrovoltaic technology has achieved notable breakthroughs in electric output via using the moving boundary of electric double layer, but the output voltage induced by droplets is saturated around 350 volts, and the underlying mechanism remains to be further clarified. Here, we show that falling water droplets can stably spark an unprecedented voltage up to 1200 volts within microseconds that they contact an electrode placed on top of an electret surface, approaching the theoretical upper limit. This sparking potential can be explained and described by a comprehensive model considering the water-electrode contact dynamics from both the macroscale droplet spreading and the microscale electric double layer formation, as well as the presence of a circuit capacitance. It is demonstrated that a droplet-induced electric spark is sufficient to directly ionize gas at atmospheric pressure and split water into hydrogen and oxygen, showing wide application potential in fields of green energy and intelligence.

Simultaneous Sensing of Velocity and Position of a Moving Light Source Using Metal-Insulator-Semiconductor Structures.

Photodetectors based on semiconductor devices have been widely used to sense light position, intensity, and wavelength. However, monitoring the motion velocity of a light beam generally requires complex integration of device arrays. Here, we report a single device of a simple metal-insulator-semiconductor structure for self-powered sensing not only position but also velocity of a light beam or shadow. A velocity-dependent voltage output between two terminals of the metal is observed. It is attributed to light illumination-induced local surface potential change in semiconductors and the following movement of local charges accumulated in the metal due to capacitive coupling. The amplitude of the velocity-dependent voltage can be facilely modulated by applying a gate voltage. These results shed light on compact devices with multiple sensing functions.

Hypothetical Proteins of Mycoplasma synoviae Reannotation and Expression Changes Identified via RNA-Sequencing.

Mycoplasma synoviae infection rates in chickens are increasing worldwide. Genomic studies have considerably improved our understanding of M. synoviae biology and virulence. However, approximately 20% of the predicted proteins have unknown functions. In particular, the M. synoviae ATCC 25204 genome has 663 encoding DNA sequences, among which 155 are considered encoding hypothetical proteins (HPs). Several of these genes may encode unknown virulence factors. This study aims to reannotate all 155 proteins in M. synoviae ATCC 25204 to predict new potential virulence factors using currently available databases and bioinformatics tools. Finally, 125 proteins were reannotated, including enzymes (39%), lipoproteins (10%), DNA-binding proteins (6%), phase-variable hemagglutinin (19%), and other protein types (26%). Among 155 proteins, 28 proteins associated with virulence were detected, five of which were reannotated. Furthermore, HP expression was compared before and after the M. synoviae infection of cells to identify potential virulence-related proteins. The expression of 14 HP genes was upregulated, including that of five virulence-related genes. Our study improved the functional annotation of M. synoviae ATCC 25204 from 76% to 95% and enabled the discovery of potential virulence factors in the genome. Moreover, 14 proteins that may be involved in M. synoviae infection were identified, providing candidate proteins and facilitating the exploration of the infection mechanism of M. synoviae.

Drug sensitivity and genome-wide analysis of two strains of Mycoplasma gallisepticum with different biofilm intensity.

Mycoplasma gallisepticum (MG) is one of the major causative agents of chronic respiratory diseases in poultry. The biofilms of MG are highly correlated to its chronic infection. However data on genes involved in biofilm formation ability are still scarse. MG strains with distinct biofilm intensity were screened by crystal violet staining morphotyped and characterized for the drug sensitivity. Two MG strains NX-01 and NX-02 showed contrasted ability to biofilm formation. The biofilm formation ability of NX-01 strain was significantly higher than that of NX-02 strain (p < 0.01). The drug sensitivity test showed that the stronger the ability of MG stain to form biofilms, the weaker its sensitivity to 17 antibiotic drugs. Moreover, putative key genes related to biofilm formation were screened by genome-wide analysis. A total of 13 genes and proteins related to biofilm formation, including ManB, oppA, oppD, PDH, eno, RelA, msbA, deoA, gapA, rpoS, Adhesin P1 precursor, S-adenosine methionine synthetase, and methionyl tRNA synthetase were identified. There were five major discrepancies between the two isolated MG strains and the five NCBI-published MG strains. These findings provide potential targets for inhibiting the formation of biofilm of MG, and lay a foundation for treating chronic infection.

Label-free quantitative detection and comparative analysis of lysine acetylation during the different life stages of Eimeria tenella.

Proteome-wide lysine acetylation has been documented in apicomplexan parasite Toxoplasma gondii and Plasmodium falciparum. Here, we conducted the first lysine acetylome in unsporulated oocysts (USO), sporulated 7 h oocysts (SO 7h), sporulated oocysts (SO), sporozoites (S), and the second generation merozoites (SMG) of Eimeria tenella through a 4D label-free quantitative technique. Altogether, 8532 lysine acetylation sites on 2325 proteins were identified in E. tenella, among which 5445 sites on 1493 proteins were quantified. In addition, 557, 339, 478, 248, 241, and 424 differentially expressed proteins were identified in the comparisons SO7h vs USO, SO vs SO7h, SO vs USO, S vs SO, SMG vs S, and USO vs SMG, respectively. The bioinformatics analysis of the acetylome showed that the lysine acetylation is widespread on proteins of diverse functions. Moreover, the dynamic changes of lysine acetylome among E. tenella different life stages revealed significant regulation during the whole process of E. tenella growth and stage conversion. This study provides a beginning for the investigation of the regulate role of lysine acetylation in E. tenella and may provide new strategies for anticoccidiosis drug and vaccine development. Raw data are publicly available at iProX with the data set identifier PXD040368.

Peach DELLA Protein PpeDGYLA Is Not Degraded in the Presence of Active GA and Causes Dwarfism When Overexpressed in Poplar and Arabidopsis.

Controlling the tree size of fruit species such as peach can reduce the amount of labor and input needed for orchard management. The phytohormone gibberellin (GA) positively regulates tree size by inducing degradation of the GA signaling repressor DELLA. The N-terminal DELLA domain in this protein is critical for its GA-dependent interaction with the GA receptor GID1 and the resulting degradation of the DELLA protein, which allows for growth-promoting GA signaling. In this study, a DELLA family member, PpeDGYLA, contains a DELLA domain but has amino acid changes in three conserved motifs (DELLA into DGYLA, LEQLE into LERLE, and TVHYNP into AVLYNP). In the absence or presence of GA3, the PpeDGYLA protein did not interact with PpeGID1c and was stable in 35S-PpeDGYLA peach transgenic callus. The overexpression of PpeDGYLA in both polar and Arabidopsis showed an extremely dwarfed phenotype, and these transgenic plants were insensitive to GA3 treatment. PpeDGYLA could interact with PpeARF6-1 and -2, supposed growth-promoting factors. It is suggested that the changes in the DELLA domain of PpeDGYLA may, to some extent, account for the severe dwarf phenotype of poplar and Arabidopsis transgenic plants. In addition, our study showed that the DELLA family contained three clades (DELLA-like, DELLA, and DGLLA). PpeDGYLA clustered into the DGLLA clade and was expressed in all of the analyzed tissues. These results lay the foundation for the further study of the repression of tree size by PpeDGYLA.

Proximal tibia osteotomy with absorbable spacer combined with fibular osteotomy versus high tibial osteotomy for medial compartmental knee osteoarthritis.

PURPOSE: The study aimed to compare the perioperative complications, short-term clinical outcomes, patient-reported outcomes, and radiographic parameters of tibiofibular proximal osteotomy combined with absorbable spacer insertion (TPOASI) and open-wedge high tibial osteotomy (OWHTO) in a two year postoperative time period. METHODS: A total of 160 patients with Kellgren-Lawrence classification grade 3 medial compartmental knee OA were randomized to receive either TPOASI (n = 82) or OWHTO (n = 78). The primary and secondary outcomes were measured preoperatively, postoperatively, and at each follow-up examination. The primary outcomes were the between-group change in the Western Ontario and McMaster Universities Global score (WOMAC). Secondary measures included visual analog scale (VAS), radiographic parameters, American Knee Society Score (KSS), operation time, blood loss, length of incision, hospital stay, and relevant complications. Postoperative radiographic parameters, including the femorotibial angle (FTA), varus angle (VA), and joint line convergence angle (JLCA), were measured to evaluate the correction of varus deformity. RESULTS: No significant differences were found in the baseline data between the two groups. Both methods improved functional status and pain postoperatively. For primary outcomes of both groups, statistical difference was observed in WOMAC scores at the 6-month follow-up (P < 0.001). For secondary outcomes, no statistical difference was observed between the groups during the 2-year follow-up (P > 0.05). For TPOASI vs. OWHTO, the mean hospital stay (6.6 ± 1.3 days vs. 7.8 ± 2.1 days) was shorter (P < 0.001), and both blood loss (70.56 ± 35.58 vs. 174.00 ± 66.33 mL) and complication rate (3.7% vs. 12.8%) were significantly lower (P < 0.005 for both). CONCLUSIONS: Both approaches showed satisfactory functional outcomes and alleviated pain. However, TPOASI is a simple, feasible method with few complications, and it could be widely used.

The normal impact stiffness of a debris-flow flexible barrier.

This paper proposes a normal oriented impact stiffness of a three-supporting cable flexible barrier under a small pretension stress to estimate the structural load behaviour, and employs two categories of small-scale debris flows (coarse and fine) to explore the stiffness evolution through physical model experiments with high-speed photography and load sensing. Results suggest that the particle-structure contact is essential to the normal load effect. Coarse debris flow performs more frequent particle-structure contact and exerts evident momentum flux, while fine debris flows with few physical collisions impart much smaller one. The middle-sited cable that receives only tensile force from vertical equivalent cable-net joint system exhibits indirect load behaviour. The bottom-sited cable shows high load feedback due to the sum of direct contact of debris flow and tensile forces. The relationship between impact loads and maximum cable deflections can be explained by power functions according to quasi-static theory. The impact stiffness is not just affected by the particle-structure contact but by the flow inertia and particle collision effect. Savage number Nsav and Bagnold number Nbag manage to depict the dynamical effects on the normal stiffness Di. Experiments indicate that Nsav has positive linear correlation with the nondimensionalization of Di, whilst Nbag has positive power correlation with the nondimensionalization of Di. This idea is an alternative scope for the study on flow-structure interaction and may contribute to the parameter identification in numerical simulation of the debris flow-structure interaction and the optimization of the design standardization.

Sequential Dual-Biofactor Release from the Scaffold of Mesoporous HA Microspheres and PLGA Matrix for Boosting Endogenous Bone Regeneration.

The combined design of scaffold structure and multi-biological factors is a prominent strategy to promote bone regeneration. Herein, a composite scaffold of mesoporous hydroxyapatite (HA) microspheres loaded with the bone morphogenetic protein-2 (BMP-2) and a poly(DL-lactic-co-glycolic acid) (PLGA) matrix is constructed by 3D printing. Furthermore, the chemokine stromal cell-derived factor-1α (SDF-1α) is adsorbed on a scaffold surface to achieve the sequential release of the dual-biofactors. The results indicate that the rapid release of SDF-1α chemokine on the scaffold surface effectively recruits bone marrow-derived mesenchymal stem cells (BMSCs) to the target defect area, whereas the long-term sustained release of BMP-2 from the HA microspheres in the degradable PLGA matrix successfully triggers the osteogenic differentiation in the recruited BMSCs, significantly promoting bone regeneration and reconstruction. In addition, these structures/biofactors specially combining scaffold exhibit significantly better biological performance than that of other combined scaffolds, including the bare HA/PLGA scaffold, the scaffold loaded with SDF-1α or BMP-2 biofactor alone, and the scaffold with surface SDF-1α and BMP-2 dual-biofactors. The utilization of mesoporous HA, the assembly method, and sequential release of the two biofactors in the 3D printed composite scaffold present a new method for future design of high-performance bone repairing scaffolds.