Facet joint asymmetry as a radiologic feature of lumbar intervertebral disc herniation in children and adolescents

STUDY DESIGN: This study compared the incidence of facet joint asymmetry between adult and juvenile patients with lumbar intervertebral disc herniation. OBJECTIVES: To determine the different distribution of the facet joint asymmetry between the adult and juvenile patients. SUMMARY OF BACKGROUND DATA: As early as 1967, it was suggested that asymmetry of the facet joints is correlated with the development of disc herniation. There have been numerous arguments for and against Farfan's hypothesis, however, most studies were carried out on adult patients, and this hypothesis has not been verified in juvenile patients. METHODS: The study group consisted of 29 levels of 25 patients aged 12-20 years (juvenile group) and 50 levels of 33 patients aged 30-49 years (adult group) who underwent posterior discectomy. The shape of facet joints, the facet joint angle, and the moment arm angle and length were measured for each facet joint using computed tomography. Facet joint asymmetry was defined as the difference in facet joint shape or a difference of more than 10 degrees in facet joint angles between the right and left sides. The incidence of facet joint asymmetry and the relationships among the facet joint asymmetry and the location, type of disc herniation, and disc degeneration were examined in juvenile and adult groups. RESULTS: The overall incidence of facet joint asymmetry was significantly higher in the juvenile group (12 levels, 41%) than in the adult group (four levels, 8%; P < 0.01). There were no significant relationships among the facet joint asymmetry, the location, type of disc herniation, and disc degeneration. CONCLUSIONS: This study revealed that the frequency of facet joint asymmetry in the juvenile group was five times higher than that in the adult group. This result indicates that facet joint asymmetry is a radiologic feature of lumbar intervertebral disc herniation in children and adolescents.     

SPR imaging of photo-cross-linked small-molecule arrays on gold

Identification of small-molecule ligands for a protein of interest can facilitate the analysis of the protein's functions in biological systems. Small-molecule microarrays have allowed for rapid detection of such ligand-protein interactions in a high-throughput manner, although a label on a protein is needed to observe these interactions. By combining SPR imaging technology with our recently developed photo-cross-linked small-molecule array platform, we developed a novel platform that allows in situ observation of interactions between photo-cross-linked small molecules on gold surfaces and nonlabeled proteins in solution. Interactions of estrogenic and androgenic substances with estrogen receptor alpha were observed using this platform.     

Two-dimensional dielectric nanosheets: novel nanoelectronics from nanocrystal building blocks

Two-dimensional (2D) nanosheets, which possess atomic or molecular thickness and infinite planar lengths, are regarded as the thinnest functional nanomaterials. The recent development of methods for manipulating graphene (carbon nanosheet) has provided new possibilities and applications for 2D systems; many amazing functionalities such as high electron mobility and quantum Hall effects have been discovered. However, graphene is a conductor, and electronic technology also requires insulators, which are essential for many devices such as memories, capacitors, and gate dielectrics. Along with graphene, inorganic nanosheets have thus increasingly attracted fundamental research interest because they have the potential to be used as dielectric alternatives in next-generation nanoelectronics. Here, we review the progress made in the properties of dielectric nanosheets, highlighting emerging functionalities in electronic applications. We also present a perspective on the advantages offered by this class of materials for future nanoelectronics.     

Analysis of molecular dynamics of colloidal particles in transported dilute samples by self-mixing laser Doppler velocimetry

Colloidal particles in a liquid medium are transported with constant velocity, and dynamic light scattering experiments are performed on the samples by self-mixing laser Doppler velocimetry. The power spectrum of the modulated wave induced by the motion of the colloidal particles cannot be described by the well-known formula for flowing Brownian motion systems, i.e., a combination of Doppler shift, diffusion, and translation. Rather, the power spectrum was found to be described by the q-Gaussian distribution function. The molecular mechanism resulting in this anomalous line shape of the power spectrum is attributed to the anomalous molecular dynamics of colloidal particles in transported dilute samples, which satisfy a nonlinear Langevin equation.     

The molecular origin of enhanced toughness in double-network hydrogels: A neutron scattering study

Double-network hydrogels (DN-gels) are a new class of crosslinked polymer networks with extraordinary mechanical properties while containing 80–90 vol.% water. Small-angle neutron scattering (SANS) was applied to investigate the molecular origin of the mechanical properties observed in DN-gels. We present SANS results in both deformed and undeformed conditions for a tough DN-gel made of poly(2-acrylamido-2-methyl-1-propane sulfonic acid) (PAMPS) and polyacrylamide (PAAm). The SANS measurements indicate that deformation of DN-gels results in periodic and mesoscale (1.5 μm) compositional fluctuations in both PAMPS and PAAm. In addition, SANS measurements also indicate that the DN-gel constituents interact favorably with each other while in water. This favorable interaction between PAMPS and PAAm is consistent with the rheological results on solution mixtures of these two polymers. The implications of the above observations to toughening mechanisms are discussed.     

EPMA mapping of small particles of α-AlFeSi and β-AlFeSi in AA6063 alloy billets

It is well known that the spatial distribution and the spatial density of the particles o-AlFeSi and -AlFeSi in the billets of Al-Mg-Si alloys, such as AA6063 alloys affect the quality of anodizing performance of their extrusions. For this reason it is very important to control the spatial distribution and the spatial density of both AlFeSi particles at extrusion plants. The X-ray diffraction method (XRD) has been used for discrimination between -AlFeSi and -ALFeSi particles. However it is not an appropriate method for determining the spatial distributions of particles in the alloys. As an alternative method an electron probe microanalyzer (EPMA) has been used for determining the spatial distributions of each element in the microstructures. However, unfortunately it is difficult to discriminate between the particles composed of the same elements like -AlFeSi and -AlFeSi particles. Thus, we tried to develop a convenient method to discriminate between -AlFeSi and -AlFeSi particles in the microstructure of AA6063 alloys and developed the EPMA mapping of -AlFeSi and -AlFeSi particles. First, in order to discriminate between the two particles, we tried to use the relative X-ray intensity ratio, the I _Fe/I _Si ratio instead of the Fe/Si mass ratio. Then, we calculated the value of the I _Fe/I _Si ratio from -AlFeSi and -AlFeSi by using Monte Carlo calculations and obtained the critical value of the I _Fe/I _Si ratio, to distinguish between -AlFeSi and -AlFeSi. After that, using the discrimination value, we developed the EPMA mapping program (EPMA method) to observe the distributions of -AlFeSi and -AlFeSi, and to calculate the areas (%) of -AlFeSi and -AlFeSi. Finally, we checked the correlation between the EPMA and the XRD methods. Consequently, the two methods were in good agreement. Today, this EPMA method instead of the XRD method is successfully used in the quality control of 6063 aluminum alloy billets after heat treatment at our aluminum extrusion works.     

Quantification of the number of EP3 receptors on a living CHO cell surface by the AFM

The distribution of EP3 receptors on a living cell surface was quantitatively studied by atomic force microscopy (AFM). Green fluorescent protein (GFP) was introduced to the extracellular region of the EP3 receptor on a CHO cell. A microbead was used as a probe to ensure certain contact area, whose surface was coated with anti-GFP antibody. The interactions between the antibodies and GFP molecules on the cell surface were recorded to observe the distribution of the receptors. The result indicated that EP3 receptors were distributed on the CHO cell surface not uniformly but in small patches coincident with immunohistochemical observation. Repeated measurements on the same area of cell surface gave confirmation that it was unlikely that the receptors were extracted from the cell membrane during the experiments. The measurement of single molecular interaction between GFP and the anti-GFP antibody was succeeded on the cell surface using compression-free force spectroscopy. The value of separation work required to break a single molecular pair was estimated to be about 1.5 x 10(-18)J. The number of EP3 receptor on the CHO cell surface was estimated using this value to be about 1 x 10(4) under the assumption that the area of the cell surface was about 5,000 microm(2). These results indicated that the number of receptors on a living cell surface could be quantified through the force measurement by the AFM.     

A new wettability‐control technique for fabricating color OLED panels by an ink‐jet‐printing method

Abstract— The fabrication technique for color OLED panels by means of wettability‐controllable hole‐injection material (HIM) and a photocatalytic lithography method achieves both precise ink‐jet printing and long‐lifetime devices. The technique enables us to selectively change the non‐wetting surface of a hole‐injection layer (HIL) of metal‐oxide nanoparticles (MONPs) into a wetting surface without damage to the device performance. Wetting patterns formed by this method with photocatalyst‐coated photomasks made it possible to print emission material with patterns of precisely 98‐μm widths on the hole‐injection layer. A fluorescent green‐emitting device fabricated with an HIM of MONPs by the photocatalytic treatment exhibited a long lifetime of 365 hours at30,000 cd/m², which can be extrapolated to a lifetime of more than 110,000 hours at 1000 cd/m², assuming an acceleration coefficient of 1.7. A two‐color device and a monochrome passive‐matrix panel were also successfully fabricated. The two‐color device emitted light without the mixing of colors. The monochrome panel displayed alphabetical characters with good uniformity and no flaws.     

PbBi-cooled direct contact boiling water small reactor

A design concept of PbBi cooled direct contact boiling water small fast reactor (PBWFR) has been formulated with some design parameters identified. Water is injected into hot PbBi above the core, and direct contact boiling takes place in chimneys. Boiling bubbles rise due to buoyancy effects, which works as a lift pump for PbBi circulation. The generated steam passes through separators and dryers for the removal of PbBi droplets, and then flows into turbines for the generation of electricity. The system pressure of 7 MPa is as the same as that of the conventional boiling water reactors (BWRs). The outlet steam is superheated by 10°C to avoid the accumulation of condensate on a PbBi free surface in the reactor vessel. The control rods are inserted from above, which is different from the original concept. This insertion was chosen since the seal of steam at the top of the reactor vessel is technically much easier than the seal of PbBi at the bottom of the reactor vessel. The electric power of 150 MWe may be the maximum which is practically possible as a small reactor with economic competitiveness to conventional LWRs. A two-region core is designed. A decrease in reactivity was estimated to be 1.5%dk/kk′ for 15 years. A fuel assembly has 271 fuel rods with 12.0 mm in diameter and 15.9 mm in pitch in a hexagonal wrapper tube. The design limit of cladding temperature is specified to be 650°C for compatibility of cladding material with PbBi. As a result, the PbBi core outlet temperature becomes 460°C. The PbBi temperature rise in the core is 150°C. The conditions of the secondary coolant steam are as the same as those of conventional BWRs with thermal efficiency of 33%. The core is designed to have the breeding ratio of 1.1 and the refueling interval of 15 years as a reactor with a long-life core. Direct heat exchangers (DHX), reactor vessel air cooling systems (RVACS) and guard vessel are designed.