We introduce a Monte Carlo model based on random deposition and diffusion limited aggregation in order to study the morphological evolution of deposition of nanofilm, which is difficult to carry out by the experimental methods. The instantaneous evolution of morphology and the corresponding parameters are observed when employing a novel perspective, modeling the aggregation of nanoscale units. Despite simplifying the chemical details, the simulation results qualitatively describe experiments with bulky precursors, and the strong dependence of growth rate on steric hindrance is obtained. Moreover, the well know behavior that the delay before steady growth is accurately predicted and analyzed based solely on modeling. Through this work, the great influence of steric hindrance on the initial stage of ALD is described.

Background: Multiple studies have investigated the use of mesenchymal stem cells (MSCs) for patients undergoing high tibial osteotomy (HTO), and the effectiveness thereof remains controversial. Purpose: To analyze the effectiveness of intra-articular MSC injection in patients who underwent HTO in terms of clinical outcomes, radiological outcomes, and cartilage repair by a meta-analysis of the available literature. Study Design: Systematic review; Level of evidence, 3. Methods: The electronic databases of PubMed, Embase, Web of Science, and the Cochrane Library were searched from their inception to October 30, 2021, for comparative studies between patients who underwent HTO with and without intra-articular injection of MSCs, according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Study quality was assessed by the Coleman Methodology Score (CMS). Data with comparable results were pooled for meta-analysis. The primary outcomes of interest were the Hospital for Special Surgery (HSS), International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), and Lysholm scores, as well as the International Cartilage Regeneration & Joint Preservation Society (ICRS) grade of cartilage repair. Radiological outcomes including femorotibial angle, posterior tibial slope, and hip-knee-ankle (HKA) angle were included as secondary outcomes. A fixed-model effect was used for meta-analyses with low heterogeneity between studies ( I 2 < 25%), while the random-model effect was used for medium- to high-heterogeneity analyses ( I 2 ≥ 25%). Results: A total of 843 studies were screened, of which 6 studies with 452 patients met the inclusion criteria and were included. The mean CMS was 81.17. Patients with MSC injection had significantly higher Lysholm scores ( P = .007) and HSS scores ( P = .01) and higher proportions of ICRS grade 1 ( P = .03) and grade 2 ( P = .02) cartilage repair in the medial femoral condyle and grade 2 cartilage repair in the tibial plateau ( P = .04). There were no significant differences between groups in the IKDC score, KOOS Pain and Symptoms subscales, femorotibial angle, posterior tibial slope, or HKA angle. Conclusion: Intra-articular MSC injection may enhance the cartilage repair for patients who undergo HTO. However, evidence of improvement in knee functions remains limited. Registration: CRD42021291345 (PROSPERO).

Osteoarthritis (OA) is chronic arthritis characterized by articular cartilage degradation. However, a comprehensive regulatory network for OA-related microRNAs and DNA methylation modifications has yet to be established. Thus, we aimed to identify epigenetic changes in microRNAs and DNA methylation and establish the regulatory network between miRNAs and DNA methylation. The mRNA, miRNA, and DNA methylation expression profiles of healthy or osteoarthritis articular cartilage samples were downloaded from Gene Expression Omnibus (GEO) database, including GSE169077, GSE175961, and GSE162484. The differentially expressed genes (DEGs), differentially expressed miRNAs (DEMs), and differentially methylated genes (DMGs) were analyzed by the online tool GEO2R. DAVID and STRING databases were applied for functional enrichment analysis and protein-protein interaction (PPI) network. Potential therapeutic compounds for the treatment of OA were identified by Connectivity map (CMap) analysis. A total of 1424 up-regulated DEGs, 1558 down-regulated DEGs, 5 DEMs with high expression, 6 DEMs with low expression, 1436 hypermethylated genes, and 455 hypomethylated genes were selected. A total of 136 up-regulated and 65 downregulated genes were identified by overlapping DEGs and DEMs predicted target genes which were enriched in apoptosis and circadian rhythm. A total of 39 hypomethylated and 117 hypermethylated genes were obtained by overlapping DEGs and DMGs, which were associated with ECM receptor interactions and cellular metabolic processes, cell connectivity, and transcription. Moreover, The PPI network showed COL5A1, COL6A1, LAMA4, T3GAL6A, and TP53 were the most connective proteins. After overlapping of DEGs, DMGs and DEMs predicted targeted genes, 4 up-regulated genes and 11 down-regulated genes were enriched in the Axon guidance pathway. The top ten genes ranked by PPI network connectivity degree in the up-regulated and downregulated overlapping genes of DEGs and DMGs were further analyzed by the CMap database, and nine chemicals were predicted as potential drugs for the treatment of OA. In conclusion, TP53, COL5A1, COL6A1, LAMA4, and ST3GAL6 may play important roles in OA genesis and development.

No abstract

Background The posterior cruciate ligament (PCL) tibial insertion and posterior septum are important factors affecting the success rate of posterior cruciate ligament reconstruction(PCLR). The purpose of this study was to accurately quantify the anatomical features and relationship of the PCL tibial insertion and posterior septum. Methods Twelve cadaveric human knees were dissected to investigate the PCL and posterior septum. First, the anatomical localization of the PCL, tibial insertion and posterior septum were observed from the medial and lateral sides of the knee joint using a U-shaped capsulotomy. Second, the border length and insertion of the PCL tibial insertion were measured with a soft ruler, and a tibial tunnel was created within the anatomical footprint of the PCL while preserving the integrity of the posterior septum, and the ratio of tunnel exit to PCL tibial insertion was calculated. Finally, HE staining was performed to evaluation the blood vessels content in the posterior septum. Results The PCL and its tibial insertion were located medial to the posterior septum in all specimens, and the inferior border of the inserion is adjacent to the posterior capsule reflexion and above the shipboard-like structure. The PCL tibial insertion had a right-angle trapezoidal-like structure with narrow superior and wide inferior sides. The superior and inferior sides of the insertion were approximately (8.8 ± 1.7) and (13.4 ± 3.2) mm, respectively, and the medial and lateral sides were approximately (11.5 ± 1.2) and (12.1 ± 0.3) mm, with an area of approximately (123.3 ± 31.4) mm². Compared to the posterior capsule, the posterior septum contained abundant blood vessels. Conclusion The PCL in the posterior compartment of the knee follows the posterior septum and is located entirely medial to the posterior septum, and the inferior border of the PCL tibial inserion is adjacent to the posterior capsule reflexion and above the shipboard-like structure. It is feasible to create an effective tibial tunnel within the tibial footprint of the PCL while preserving the posterior septum.