Spatial Association characteristics of facilities around scenic spots considering distance and orientation: A case study of 3A and above scenic spots in Beijing

In the urban tourism and service industry, the POI data with coordinate and attribute information of the major map platforms constitute one of the important data sources of the urban tourism and service industry. In this paper, the spatial data transaction database under four distances was established based on the gate buffer of 3A and above scenic spots in Beijing. The Apriori algorithm was used to calculate the lifting degree to obtain the distance for mining the best association features of 3A, 4A and 5A scenic spots, and then the association features of the three scenic spots in different directions were analysed

Episodes of single-crystal material removal mode and machinability in the micro-cutting process of superalloy Inconel-718

The development tendency of miniaturization gives birth to the demand for Inconel-718 miniature parts, and micro-cutting is a promising technique to produce crystalline material miniature parts. Unfortunately, due to the non-negligible edge radius and property anisotropy, the material deformation behaviour and removal mode vary with cutting conditions, resulting in volatile machinability and inferior quality, which hinders the widespread application of Inconel-718 miniature parts. Therefore, it is urgent to clarify the evolution of material removal mode and machinability of Inconel-718 micro-cutting. Existing researches fail to consider the property anisotropy, strain-rate sensitivity and strain-rate inhomogeneity. This paper establishes strain rate-considered single-crystal micro-cutting models and performs simulations under varying cutting conditions, aiming to depict the episodes of material removal mode and machinability of Inconel-718 micro-cutting. Results show that, uncut chip thickness and cutter rake angle influence the material removal mode, and in turn influence machinability. For Inconel-718 single-crystal with [0° 0° 0°] orientation, the transition from the scratching mode to the ploughing mode is in the uncut chip thickness range of 0.2Re∼0.4Re, and the transition from the ploughing mode to the cutting mode is in the uncut chip thickness range of 0.6Re∼0.8Re or the rake angle range of −30°∼-15°. In comparison, cutting speed and clearance angle have little effect on material removal mode. Cutting speed influences the strain rate of the cutting-affected zone, and in turn influences machinability. The maximum strain rate of the cutting-affected zone is respectively around 0.45 s−1 and 10,960 s−1 under the cutting speeds of 2Re/s and 20000Re/s

Cloud-inspired multiple scattering for light intensified photochemical flow reactors

10.1039/d0re00080aReaction Chemistry & Engineering561058-106

Pericellular collagen I coating for enhanced homing and chondrogenic differentiation of mesenchymal stem cells in direct intra-articular injection

Abstract Background Direct intra-articular injection (DIAI) of mesenchymal stem cells (MSCs) is a promising technique for cartilage repair. However, the repair process was hindered by the absence of scaffold and poor cell–matrix interactions. Methods In this study, we developed a pericellular collagen I coating (PCC) on MSCs. The overall performances of MSC-PCC homing, chondrogenic differentiation, and cartilage regeneration have been comprehensively evaluated in a New Zealand rabbit model. Firstly, we examined the morphology and physical characteristics of PCC. Secondly, MSC ex-vivo cartilage slice adhesion and in-vivo cartilage defect homing were observed using multiscale methods. Thirdly, the precartilage condensation of cell pellets formed by aggregation of MSCs was examined to evaluate the cartilage-inducing potential of PCC. Finally, the cartilage regeneration by DIAI of PCC-coated MSCs was observed and scored macroscopically and histologically. Results In general, the cell adhesion and homing assay revealed that PCC facilitated MSC adhesion on cartilage slices, enhancing MSC homing and retention to cartilage defect. This increased homing ratio was accompanied by an increasing cell–cell contact. Compared with naked MSCs, the cell pellets formed by PCC-coated MSCs exhibited more evident appearance of condensation. In pellets, cell–cell interaction has been significantly stimulated, inducing the expression of condensation marker N-cadherin, and subsequent chondrogenic marker collagen II and aggrecan. By 12 weeks after DIAI, cartilage defects have been repaired by MSCs to varying degrees. Overall, PCC significantly enhances the quality of cartilage regeneration judging from macroscopic observation, ICRS score, histological examination, and collagen type I, II, and X immunohistochemical staining. Conclusions The capacity and viability of MSCs can be enhanced by collagen I coating, which provides cues for enhancing cell homing and differentiation. Our method provides a novel strategy for stem cell therapy

Interleukin-17 Can Induce Osteoarthritis in Rabbit Knee Joints Similar to Hulth’s Method

Interleukin-17 (IL-17) is closely related to osteoarthritis (OA), but animal studies that employ IL-17 to induce OA are currently lacking. Therefore, this study evaluated the effect of IL-17 in the rabbit knee joint. The right knees served as the control group. The left knees were divided randomly into 4 groups: a Hulth group and 3 IL-17 groups (1-ng, 10-ng, and 50-ng groups). OA was induced in the Hulth group using Hulth’s method. The IL-17 groups were injected with 1, 10, or 50 ng of IL-17 as indicated. Specimens were collected at 72 h, 1 week, 3 weeks, 6 weeks, and 12 weeks after surgery or the last injection. Subsequently, the following experiments were conducted: X-ray analysis, histological evaluation, and polymerase chain reaction (PCR) analysis of the mRNA expression levels of cartilage degeneration-related markers. At 12 weeks, like the Hulth group, the 10-ng and 50-ng IL-17 groups displayed typical manifestations of OA. The X-ray results, histological scores, and mRNA expression levels showed statistically significant differences between the control group and the 10-ng and 50-ng IL-17 groups. In sum, injecting 10 ng of IL-17 into the rabbit knee joint can induce OA similar to OA induced by Hulth’s method

Additional file 2: of Pericellular collagen I coating for enhanced homing and chondrogenic differentiation of mesenchymal stem cells in direct intra-articular injection

Figure S2. Ex-vivo adhesion of MSCs suspended in col. I solution. BLIS analysis of MSCs suspended in 10 ng/ml, 500 ng/ml, and 10μg/ml col. I solution on cartilage slices. MSCs pretransfected by luciferase and the total adhered MSC number calculated by luminescent intensity (n = 5 in each group). (JPG 86 kb

Additional file 1: of Pericellular collagen I coating for enhanced homing and chondrogenic differentiation of mesenchymal stem cells in direct intra-articular injection

Figure S1. Concentration of residual collagen I in MSC suspension after PCC. Concentration of col. I detected (n = 5) by Rat Collagen I ELISA Kit (LSBio, USA). (JPG 133 kb

Additional file 3: of Pericellular collagen I coating for enhanced homing and chondrogenic differentiation of mesenchymal stem cells in direct intra-articular injection

Figure S3. In-vivo homing suspended in col. I solution. a, b BLIS analysis of luminescent distribution within left knees of New Zealand rabbits at 2 days after DIAI of luciferase-labeled MSCs or MSCs suspended in 10 ng/ml col. I solution. Red frames indicate cartilage defect (a, n = 3 in each group). Luminescent intensity of total ROI radiance within cartilage defect (red frame) calculated to reveal homing of MSCs (b). a Sagittal frozen sections of cartilage lesion site, red particles are CM-DiI-labeled MSCs (scale bar, 400 μm). (TIF 1614 kb