Effect of gel spinning accompanied with cross‐linking using boric acid on the structure and properties of high‐molecular‐weight poly(vinyl alcohol) fiber

To enhance the thermal stability of poly(vinyl alcohol) (PVA) fiber, the fiber was prepared from the gel spinning of high molecular weight (HMW) PVA by using dimethyl sulfoxide/water (8/2, v/v) as a solvent, accompanied with the cross‐link by boric acid (B‐PVA). In addition, the structure and properties of the B‐PVA fiber were compared with those of the HMW PVA fiber obtained by using the same spinning system without cross‐linking (NB‐PVA). Through a series of experiments, it turned out that cross‐linking actualized by an optimum amount of boric acid (0.3 wt % based on PVA) and zone drawing caused significant changes in the properties of HMW PVA gel fiber. That is, cross‐linking increased thermal degradation temperatures at each degradation step and amounts of final residues, resulting in improving thermal properties of the PVA fiber. On the contrary, it was found that in the case of the B‐PVA fiber, some broadening of the original PVA unit cell occurred, which was identified by the peak shift to lower angle in X‐ray diffractogram. The tensile strength and Young's modulus of B‐PVA fiber with draw ratio of 15 are 23.1 and 308.3 g/d, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Microarray Analysis of Oligosaccharide‐Mediated Multivalent Carbohydrate–Protein Interactions and Their Heterogeneity

Carbohydrate–protein interactions (CPIs) are involved in a wide range of biological phenomena. Hence, the characterization and presentation of carbohydrate epitopes that closely mimic the natural environment is one of the long‐term goals of glycosciences. Inspired by the multivalency, heterogeneity and nature of carbohydrate ligand‐mediated interactions, we constructed a combinatorial library of mannose and galactose homo‐ and hetero‐glycodendrons to study CPIs. Microarray analysis of these glycodendrons with a wide range of biologically important plant and animal lectins revealed that oligosaccharide structures and heterogeneity interact with each other to alter binding preferences.     

Comparison of Vehicle Control Systems Based on Multiple Features

In striving to achieve autonomous navigation, the guidance system plays an essential role. In this article, the authors present two recently developed vision-based methods to estimate the heading angle of the vehicle. The authors propose a real-time guidance application based on edge and color information using an omnidirectional image. First, line segments were extracted. Second, the Random Sample Consensus (RANSAC) curve fitting method was implemented. Third, the set of intersection points for each pair of curves was extracted. Finally, by implementing the Density Based Spatial Clustering of Applications with Noise (DBSCAN) algorithms, the heading angle was computed. The main contribution of this work is in the evaluation of the methods applied, which included the “edge-based extraction in road scenes” method, which uses the spatial density information around the vehicle (curbs, barrier, gutters, side strip areas), and the “edge-based lane marking segmentation.” Both of these methods were evaluated in terms of the performance assessment of the length of the line segments in relation to the heading angle measurement. In that sense, the experiments were conducted for the purpose of testing the processing time and the number of extracted line segments. The preliminary results were gathered and tested on a group of consecutive frames to demonstrate the effectiveness of the proposed methods.     

Diatom‐Inspired Silica Nanostructure Coatings with Controllable Microroughness Using an Engineered Mussel Protein Glue to Accelerate Bone Growth on Titanium‐Based Implants

Silica nanoparticles (SiNPs) have been utilized to construct bioactive nanostructures comprising surface topographic features and bioactivity that enhances the activity of bone cells onto titanium‐based implants. However, there have been no previous attempts to create microrough surfaces based on SiNP nanostructures even though microroughness is established as a characteristic that provides beneficial effects in improving the biomechanical interlocking of titanium implants. Herein, a protein‐based SiNP coating is proposed as an osteopromotive surface functionalization approach to create microroughness on titanium implant surfaces. A bioengineered recombinant mussel adhesive protein fused with a silica‐precipitating R5 peptide (R5‐MAP) enables direct control of the microroughness of the surface through the multilayer assembly of SiNP nanostructures under mild conditions. The assembled SiNP nanostructure significantly enhances the in vitro osteogenic cellular behaviors of preosteoblasts in a roughness‐dependent manner and promotes the in vivo bone tissue formation on a titanium implant within a calvarial defect site. Thus, the R5‐MAP‐based SiNP nanostructure assembly could be practically applied to accelerate bone‐tissue growth to improve the stability and prolong the lifetime of medical implantable devices.     

Qualitative study of young,adult, and aged wistar rats temporomandibular synovial membrane employing light,scanning, and transmission electron microscopy

The aim of this study was to analyze the rat temporomandibular joint (TMJ) synovial membrane at different ages using light, scanning, and transmission electron microscopy. Under light microscopic analysis, the TMJ structures were observed such as condyle, capsule, disk, the synovial membrane collagen type, and cells distribution. In the scanning electron microscopy, the synovial membrane surface exhibited a smooth aspect in young animals and there was an increase with ageing in the number of folds. The transmission electron microscopic analysis showed more synoviocytes in the synovial layer in the young group and still a great number of vesicles and cisterns dilation of rough endoplasmic reticulum in the aged group. In the three groups, a dense layer of collagen fibers in the synovial layer and cytoplasmic extensions were clearly seen. It was possible to conclude that synovial membrane structures in aged group showed alterations contributing to the decrease in joint lubrication and in the sliding between disk and joint surfaces. These characteristic will reflect in biomechanics of chewing, and may cause the TMJ disorders, currently observed in clinical processes. Microsc. Res. Tech. © 2012 Wiley Periodicals, Inc.     

ANFIS modeling of surface roughness in abrasive waterjet machining of carbon fiber reinforced plastics

Journal of Mechanical Science and Technology - This study discusses the development of an Adaptive neuro–fuzzy inference system (ANFIS) model for determining the surface roughness (Ra) during...