Forecasting of strength and durability properties of High Performance Composites by Artificial Neural Networks (ANN)

High Performance Concrete (HPC) is the high quality concrete that requires special conformity and performance requirements. The objective of this study was to investigate the possibilities of adapting neural expert system like Artificial Neural Network (ANN) in the development of simulator and intelligent system and to predict durability and strength of HPC composites. This soft computing methods emulates the decision-making ability of a human expert benefits both the construction industry and the research community. These new methods, if properly utilized, have the potential to increase speed, service life, efficiency, consistency, minimizes errors, saves time and cost which would otherwise be squandered using the conventional approaches.</jats:p

Forecasting of strength and durability properties of High Performance Composites by Artificial Neural Networks (ANN)

High Performance Concrete (HPC) is the high quality concrete that requires special conformity and performance requirements. The objective of this study was to investigate the possibilities of adapting neural expert system like Artificial Neural Network (ANN) in the development of simulator and intelligent system and to predict durability and strength of HPC composites. This soft computing methods emulates the decision-making ability of a human expert benefits both the construction industry and the research community. These new methods, if properly utilized, have the potential to increase speed, service life, efficiency, consistency, minimizes errors, saves time and cost which would otherwise be squandered using the conventional approaches

Redifferentiation of Articular Chondrocytes by Hyperacute Serum and Platelet Rich Plasma in Collagen Type I Hydrogels

Matrix-assisted autologous chondrocyte transplantation (MACT) for focal articular cartilage defects often fails to produce adequate cartilage-specific extracellular matrix in vitro and upon transplantation results in fibrocartilage due to dedifferentiation during cell expansion. This study aimed to redifferentiate the chondrocytes through supplementation of blood-products, such as hyperacute serum (HAS) and platelet-rich plasma (PRP) in vitro. Dedifferentiated monolayer chondrocytes embedded onto collagen type I hydrogels were redifferentiated through supplementation of 10% HAS or 10% PRP for 14 days in vitro under normoxia (20% O2) and hypoxia (4% O2). Cell proliferation was increased by supplementing HAS for 14 days (p &lt; 0.05) or by interchanging from HAS to PRP during Days 7&ndash;14 (p &lt; 0.05). Sulfated glycosaminoglycan (sGAG) content was deposited under both HAS, and PRP for 14 days and an interchange during Days 7&ndash;14 depleted the sGAG content to a certain extent. PRP enhanced the gene expression of anabolic markers COL2A1 and SOX9 (p &lt; 0.05), whereas HAS enhanced COL1A1 production. An interchange led to reduction of COL1A1 and COL2A1 expression marked by increased MMP13 expression (p &lt; 0.05). Chondrocytes secreted less IL-6 and more PDGF-BB under PRP for 14 days (p &lt; 0.0.5). Hypoxia enhanced TGF-&beta;1 and BMP-2 release in both HAS and PRP. Our study demonstrates a new approach for chondrocyte redifferentiation

Hyaluronan thiomer gel/matrix mediated healing of articular cartilage defects in New Zealand White rabbits—a pilot study

Abstract Background Articular cartilage defects are limited to their regenerative potential in human adults. Our current study evaluates tissue regeneration in a surgically induced empty defect site with hyaluronan thiomer as a provisional scaffold in a gel/matrix combination without cells on rabbit models to restore tissue formation. Methods An osteochondral defect of 4 mm in diameter and 5 mm in depth was induced by mechanical drilling in the femoral center of the trochlea in 18 New Zealand White rabbits. Previously evaluated from an in vitro study hyaluronan thiomer matrix, and a hyaluronan thiomer gel was used to treat the defect. As a control, the defect was left untreated. During the whole study, rabbits were clinically examined and after 4 (n = 3) or 12 (n = 3) weeks, the rabbits were sacrificed. Joints were evaluated macroscopically (Brittberg score) and by histology (O’Driscoll score). Synovial cells from the synovial fluid smear were histopathologically evaluated. Results The healing of the defects varied intra-group wise at the first observation period. After 12 weeks the results concerning the cartilage repair score were inhomogeneous within each group, while the macroscopic analysis was more homogenous. In the synovial fluid smear, the mean score of infiltrated synovial and non-synovial cells was slightly increased after 4 weeks and slightly decreased after 12 weeks in both the treatment groups in comparison to the untreated control. Conclusions Taken together with results from the in vivo study indicated that implantation of hyaluronan thiomer as a combination of gel and matrix might enhance articular cartilage regeneration in an empty defect. Despite their benefits, the intrinsic healing capacity of New Zealand rabbits is a limitation for comparative test subject in pre-clinical models of cartilage defects

Platelet-Rich Plasma Supports Proliferation and Redifferentiation of Chondrocytes during In Vitro Expansion

Articular cartilage regeneration is insufficient to restore sports injuries or defects that can occur from trauma. Treatment options for cartilage repair include autologous chondrocyte implantation (ACI) by isolation, expansion, and reimplantation of healthy donor chondrocytes. Chondrocyte expansion onto 2D substrates leads to dedifferentiation and loss of the cellular phenotype. We aimed to overcome the state of dedifferentiation by biochemical stimuli with platelet derivatives such as platelet-rich plasma (PRP) and hyperacute serum (HAS) to achieve sufficient cell numbers in combination with variable oxygen tension. Human articular chondrocytes from osteoarthritic (OA) cartilage chondrocytes were switched from 10% FCS supplementation to either 10% PRP or 10% HAS after initial passaging for further experiments under normoxic (20% O2) or hypoxic (1% O2) conditions. An XTT assay measured the effect of PRP or HAS on the cell proliferation at 3, 6, and 9 days. The chondrogenic redifferentiation potential of dedifferentiated chondrocytes was determined with reverse transcriptase quantitative real-time PCR for markers of expression for type II collagen (COL2A1), type I collagen (COL1A1), and matrix metalloproteinases MMP3, matrix metalloproteinase 13 (MMP13) at 24 and 72 h. Measured protein levels of 100% PRP or HAS by multiplex quantification revealed basic fibroblast growth factor, G-CSF, and PDGF were significantly higher in PRP than in HAS (p &lt; 0.05) but LEPTIN levels did not differ. The quantified protein levels did not differ when isolated from same donors at a different time. Chondrocyte proliferation indicated that supplementation of 10% HAS enhanced the proliferation rate compared to 10% PRP or 10% FCS at 6 and 9 days significantly (p &lt; 0.05). mRNA levels for expression of COL1A1 were significantly downregulated (p &lt; 0.05) when cultured with 10% PRP than 10% HAS or 10% FCS under normoxic/hypoxic conditions. COL2A1 was significantly upregulated (p &lt; 0.05) in PRP than 10% HAS or 10% FCS. MMP3 expression was downregulated after 72 h under all conditions. MMP13 was upregulated with 10% PRP at both 24 and 72 h but significantly downregulated under hypoxia (1% O2) for all circumstances. While HAS has its effect on chondrocyte proliferation, PRP enhances both proliferation and redifferentiation of dedifferentiated chondrocytes. PRP can replace standard usage of FCS for chondrogenic priming and expansion as implications for clinical use such as ACI procedures