outer-boundary-assisted-segmentation-quantification-trabecular-bones

Outer-Boundary Assisted Segmentation and Quantification of Trabecular Bones by an Imagej Plugin

Micro-computed tomography (micro-CT) is routinely used to assess bone quantity and trabecular microstructural properties in small animals under different ...

wuhan university

Quaternary ammonium chitosan sulfates with diverse degrees of substitution (DS) ascribed to sulfate groups between 0.52 and 1.55 were synthesized by reacting quaternary ammonium chitosan with an uncommon sulfating agent (N(SO(3)Na)(3)) that was prepared from sodium bisulfite (NaHSO(3)) through reaction with sodium nitrite (NaNO(2)) in the aqueous system homogeneous. The structures of the derivatives were characterized by FTIR, (1)H NMR and (13)C NMR. The factors affecting DS of quaternary ammonium chitosan sulfates which included the molar ratio of NaNO(2) to quaternary ammonium chitosan, sulfated temperature, sulfated time and pH of sulfated reaction solution were investigated in detail. Its anticoagulation activity in vitro was determined by an activated partial thromboplastin time (APTT) assay, a thrombin time (TT) assay and a prothrombin time (PT) assay. Results of anticoagulation assays showed quaternary ammonium chitosan sulfates significantly prolonged APTT and TT, but not PT, and demonstrated that the introduction of sulfate groups into the quaternary ammonium chitosan structure improved its anticoagulant activity obviously. The study showed its anticoagulant properties strongly depended on its DS, concentration and molecular weight.

Synthesis and anticoagulant activity of the quaternary ammonium chitosan sulfates.

Carboxymethyl chitosan (CMC) was chemically modified by sulfating agent N(SO(3)Na)(3). The product carboxymethyl chitosan sulfate (CMCS) was characterized by Fourier transform infrared spectroscopy (FT-IR) and carbon-13 nuclear magnetic resonance spectroscopy ((13)C NMR). And the optimal reaction conditions were also studied by means of single factor experiment. MTT method was applied to evaluate the effects of CMCS on proliferation of skin fibroblasts. The results revealed the CMCS with sulfate content of 26.26% at the concentration of 100 μg/ml best promoted the proliferation of skin fibroblasts.

Preparation of carboxymethyl chitosan sulfate for improved cell proliferation of skin fibroblasts.

Collagen peptides grafted sodium alginate (SA-COP) was prepared by reacting alginate with collagen peptide via amide linkage in presence of 1-ethyl-(dimethylaminopropyl) carbodiimide (EDC) and N-hydroxy sulfosuccinimide (NHS). The reaction conditions affected the degree of substitution (DS) were studied including the mass ratio of collagen peptide to sodium alginate, reaction temperature and reaction time. The hydrogen peroxide scavenging activity could be controlled by adjusting the DS, concentration and molecular weight. MTT assay was used to investigate the cell viability of SA-COP. The results indicated that the SA-COP exhibited better cell viability, and with the DS and concentration increasing of SA-COP, cell viability increased. The improved functionalities of the derivative might be explained by peptides characteristics.

Preparation and characterization of sodium alginate modified with collagen peptides.

Notch controls skeletogenesis, but its role in the remodeling of adult bone remains conflicting. In mature mice, the skeleton can become osteopenic or osteosclerotic depending on the time point at which Notch is activated or inactivated. Using adult EGFP reporter mice, we find that Notch expression is localized to osteocytes embedded within bone matrix. Conditional activation of Notch signaling in osteocytes triggers profound bone formation, mainly due to increased mineralization, which rescues both age-associated and ovariectomy-induced bone loss and promotes bone healing following osteotomy. In parallel, mice rendered haploinsufficient in γ-secretase presenilin-1 (Psen1), which inhibits downstream Notch activation, display almost-absent terminal osteoblast differentiation. Consistent with this finding, pharmacologic or genetic disruption of Notch or its ligand Jagged1 inhibits mineralization. We suggest that stimulation of Notch signaling in osteocytes initiates a profound, therapeutically relevant, anabolic response.

Anabolic actions of Notch on mature bone.

The ability to identify hazardous traffic events is already considered as one of the most effective solutions for reducing the occurrence of crashes. Only certain particular hazardous traffic events have been studied in previous studies, which were mainly based on dedicated video stream data and GPS data. The objective of this study is twofold: (1) the Markov blanket (MB) algorithm is employed to extract the main factors associated with hazardous traffic events; (2) a model is developed to identify hazardous traffic event using driving characteristics, vehicle trajectory, and vehicle position data. Twenty-two licensed drivers were recruited to carry out a natural driving experiment in Wuhan, China, and multi-sensor information data were collected for different types of traffic events. The results indicated that a vehicle's speed, the standard deviation of speed, the standard deviation of skin conductance, the standard deviation of brake pressure, turn signal, the acceleration of steering, the standard deviation of acceleration, and the acceleration in Z (G) have significant influences on hazardous traffic events. The sequential minimal optimization (SMO) algorithm was adopted to build the identification model, and the accuracy of prediction was higher than 86%. Moreover, compared with other detection algorithms, the MB-SMO algorithm was ranked best in terms of the prediction accuracy. The conclusions can provide reference evidence for the development of dangerous situation warning products and the design of intelligent vehicles.

Song Gao

wuhan university

Outer-Boundary Assisted Segmentation and Quantification of Trabecular Bones by an Imagej Plugin