7,968 research outputs found
EVOLVING CONCEPTS OF CHONDROGENIC DIFFERENTIATION: HISTORY, STATE-OF-THE-ART AND FUTURE PERSPECTIVES
As a cell source, multipotent mesenchymal stromal cells or mesenchymal stem cells (MSCs) are promising candidates for chondrogenic differentiation and subsequent cartilage regeneration. From previous literature, it is known that chondrogenic differentiation of MSCs inevitably leads to hypertrophy and subsequent endochondral ossification. In this review, we examine the history of currently established protocols of chondrogenic differentiation and elaborate on the roles of individual components of chondrogenic differentiation medium. We also summarise the effects of physical, chemical and biological factors involved, and propose potential strategies to differentiate MSCs into articular chondrocytes with homogenous mature phenotypes through spatial-temporal incorporation of cell differentiation and chondrogenesis
Cloning and expression of a tomato glutathione S- transferase (GST) in Escherichia coli
Glutathione S- transferases (GSTs) fulfill a diverse range of functions in an organism. In a previous study, a putative glutathione S-transferase gene (ShGSTU1) from a wild-type tomato, Solanum habrochaites G1.1560, was identified to be a key gene in pathogen resistant response against powdery mildew in tomato. In this study, ShGSTU1 was cloned into plasmid pET-28a, efficiently expressed in Escherichia coli upon isopropyl-β-D-1-thiogalactopyronoside (IPTG) induction, purified with Ni2+ affinity chromatography and biochemically characterized. The results show that the optimal conditions for the expression of recombinant ShGSTU1 in E. coli were growth under 37°C, and 4-h IPTG induction with 1 mM concentration. About 18.93 mg ShGSTU1 was recovered from 1 g wet bacteria. The recombinant ShGSTU1 exhibited enzymatic activity with specific activity 0.625 U/mg. These results might provide a significant foundation for the later research on the mechanism of ShGSTU1 in tomato resistance to powdery mildew.Key words: Tomato, glutathione S-transferase, expression, purification, enzyme activity
Tetrahydro-1,4-thiazine-3,5-dione
The X-ray structure of the title compound contains eight molecules in the unit cell which form the basis of a herringbone arrangement of hydrogen bonded ribbons.Publisher PDFPeer reviewe
ELECTRONIC STRUCTURE OF FeSi
The full set of high-energy spectroscopy measurements including X-ray
photoelectron valence band spectra and soft X-ray emission valence band spectra
of both components of FeSi (Fe K_beta_5, Fe L_alpha, Si K_beta_1,3 and Si
L_2,3) are performed and compared with the results of ab-initio band structure
calculations using the linearized muffin-tin orbital method and linearized
augmented plane wave method.Comment: 11 pages + 3 PostScript figures, RevTex3.0, to be published in
J.Phys.:Cond.Matte
The Expression and Roles of Nde1 and Ndel1 in the Adult Mammalian Central Nervous System
Open Access funded by Wellcome Trust Under a Creative Commons license Acknowledgments We thank Prof Angelo Sementilli, Department of Pathology, Universidade Metropolitana de Santos, SP, Brazil, for the human sample collection. This study is funded by Scottish Universities Life Sciences Alliance (HR07019 to S. Shen and C.D. McCaig), Medical Research Scotland (384 FRG to B. Lang, United Kingdom), Tenovus Scotland (G12/25 to B. Lang), Sino-UK Higher Education Research Partnership for PhD Studies (C.D. McCaig and Y.Q. Ding) and Wellcome Trust (WT081633MA-NCE to P.J.A. McCaffery, United Kingdom).Peer reviewedPublisher PD
Constitutive model of 3Cr23Ni8Mn3N heat-resistant steel based on back propagation (BP) neural network (NN)
The 3Cr23Ni8Mn3N heat-resistant steel was subjected to isothermal constant strain rate compression experiments using a Gleeble - 1 500D thermal simulator. The thermal deformation behavior in the range of deformation temperature 1 000 - 1 180 °C and strain rate 0,01 - 10 s-1 was studied. Based on experimental data, the stress-strain curves of 3Cr23Ni8Mn3N were established. And the constitutive relation of BP neural network (3 × 10 × 10 × 1) was constructed. The flow stress was predicted and compared by the ANN constitutive model. The correlation coefficient (R) is 0,999, and the average relative error (AARE) is 0,697 %. The results show that the ANN constitutive model has high accuracy for predicting the thermal deformation behavior of 3Cr23Ni8Mn3N. The model can provide a good reference value for thermal processing
Johnson-Cook model for TC4 titanium alloy based on compression experiment
To obtain the exact mechanical properties of TC4 titanium alloy, the compression experiments on TC4 titanium alloy at different strain rates (10-2,10-3,10-4 s-1) were performed at room-temperature on the MTS-810 electrohydraulic servo material testing machine. The data of TC4 titanium alloy compression experiments at different rates were obtained. And furthermore Johnson-Cook constitutive model is established. Due to different conditions, the equation is simplified, the constitutive parameters are obtained by step-by-step estimation method, and the Johnson- Cook (JC) constitutive model of TC4 titanium alloy at room temperature is established. The prediction results of the model were compared with the experimental data, the prediction curve is in good agreement, which verifies the feasibility of the model
Johnson-Cook model for TC4 titanium alloy based on compression experiment
To obtain the exact mechanical properties of TC4 titanium alloy, the compression experiments on TC4 titanium alloy at different strain rates (10-2,10-3,10-4 s-1) were performed at room-temperature on the MTS-810 electrohydraulic servo material testing machine. The data of TC4 titanium alloy compression experiments at different rates were obtained. And furthermore Johnson-Cook constitutive model is established. Due to different conditions, the equation is simplified, the constitutive parameters are obtained by step-by-step estimation method, and the Johnson- Cook (JC) constitutive model of TC4 titanium alloy at room temperature is established. The prediction results of the model were compared with the experimental data, the prediction curve is in good agreement, which verifies the feasibility of the model
Experimental study of breathers and rogue waves generated by random waves over non-uniform bathymetry
Experimental results describing random, uni-directional, long crested, water
waves over non-uniform bathymetry confirm the formation of stable coherent wave
packages traveling with almost uniform group velocity. The waves are generated
with JONSWAP spectrum for various steepness, height and constant period. A set
of statistical procedures were applied to the experimental data, including the
space and time variation of kurtosis, skewness, BFI, Fourier and moving Fourier
spectra, and probability distribution of wave heights. Stable wave packages
formed out of the random field and traveling over shoals, valleys and slopes
were compared with exact solutions of the NLS equation resulting in good
matches and demonstrating that these packages are very similar to deep water
breathers solutions, surviving over the non-uniform bathymetry. We also present
events of formation of rogue waves over those regions where the BFI, kurtosis
and skewness coefficients have maximal values.Comment: 41 pages, 21 figure
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