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The attrition of enamel when opposed by ceramics is of great concern. The purpose of this study was to evaluate enamel wear against high translucent zirconia (Zr), lithium disilicate (LD), gold (Au), and enamel (E) with different surface and contact conditions. The materials were divided into two groups: polished and ground (n=8 each). Two-body wear tests were performed against human enamel with vertical and horizontal, horizontal, and vertical repetitive movements as experiments 1 to 3 respectively. The surface roughness of all materials except Zr changed throughout the experiments. In experiment 1, Zr and Au showed less antagonist wear when polished than when ground. In experiment 2, polished groups showed less antagonist wear than ground groups in all materials. In experiment 3, Zr and LD exerted greater antagonist wear than E, regardless of Ra. These findings confirm the importance of polishing and occlusal adjustment of zirconia.

Purpose: To evaluate marginal bone level changes over 3 years around platform-shifting implants with internal conical connections, and to identify the factors relating to bone level changes. Materials and methods: Systemically healthy patients who lost one tooth or two consecutive teeth were enrolled in the study. The subjects received one or two implants with platform-shifting and internal conical connections in healed bone in a submerged manner. Digital standardized periapical radiographs were obtained at the time of implant placement, at prosthesis delivery, at 1 year, and at 3 years after the definitive restorations. Marginal bone level changes were measured at the mesial and distal aspects of each implant. Spearman correlation coefficients were calculated to examine the correlation between marginal bone level changes and clinical factors (age, vertical mucosal thickness, implant length and diameter, insertion torque value, and vertical implant position). Results: Twenty-five patients with 30 implants (8 men and 17 women, mean age: 61.24 ± 13.18 years) were followed up to 3 years after the definitive restorations. The implant survival rate was 100%, and no remarkable complications were found. Mean peri-implant marginal bone level changes were -0.41 ± 0.61 mm (from placement to prosthesis delivery: C1); -0.08 ± 0.54 mm (from prosthesis delivery to 1 year: C2); -0.04 ± 0.95 mm (from prosthesis delivery to 3 years: C3); and 0.04 ± 0.60 mm (from 1 year to 3 years: C4), respectively. Statistically significant differences in bone level changes were observed between C1 and C3, and C1 and C4. Significant correlations of marginal bone level changes with implant diameter in C1 and with vertical implant position in C2 and C3 were observed. Conclusion: Within the limitations of this study, platform-shifting implants with internal conical connections appeared to prevent marginal bone resorption, especially after delivery of definitive prostheses, although marginal bone resorption attributed to the reestablishment of biologic width following subcrestal placement might be unavoidable.

A simple method was developed to isolate the compound middle lamella (CML) in its natural state using wet-beating, sedimentation, and methanol dialysis. The isolated CML fraction was characterised. The CML was isolated in 2.0% yield from the mature wood of Ginkgo biloba. Scanning electron microscopy (SEM) images of the isolated CML fraction showed the presence of flake-like structures. However, some small amounts of secondary wall substance was observed. The lignin content of the CML fraction was approximately 45%. Thioacidolysis reactions with the isolated CML fraction revealed that the lignin β-O-4 structure was scarce in the isolated fraction and that numerous structures with two or more consecutive condensed-type bonds were present. Results from the solid-state carbon-13 nuclear magnetic resonance (13C NMR) experiments indicated that the CML fraction had low crystallinity, indicating low cellulose content. Liquid-state NMR analysis of the lignin from the CML fraction revealed the absence of p-hydroxyphenyl (H) units.

Lignin is thought to be covalently bound to carbohydrates like hemicellulose during biosynthesis to form a lignin-carbohydrate complex (LCC). However, successive polymerisation with monolignols after the formation of LCC has not yet been clarified. To investigate the reaction of LCC, its enzymatic dehydrogenative polymerisation was conducted using deuterium-labelled coniferyl alcohol and model compounds, i.e., a lignin model (β-O-4 dimer model) compound (LM) and an LCC model (benzyl ether type) compound (LCCM). The obtained polymers (DHPs) were methylated and subjected to thioacidolysis, and the degradation products were quantified by gas chromatography-mass spectrometry (GC-MS). The results showed that the amount of coniferyl alcohol connected to the LCCM via β-O-4 binding was almost the same as that bound to the LM. However, the amount of unreacted LCCM was larger than that of LM, suggesting that the LCCM is less likely to form condensed structures, i.e., 5-5, β-5, and 4-O-5 structures. This could be due to the steric hindrance of the carbohydrate at the benzylic position.

Radiometrically calibrating nonlinear images from Internet photo collections makes photometric analysis applicable not only to lab data but also to big image data in the wild. However, conventional calibration methods cannot be directly applied to such photo collections. This paper presents a method to jointly perform radiometric calibration for a set of nonlinear images in Internet photo collections. By incorporating the consistency of scene reflectance of corresponding pixels across nonlinear images, the proposed method first estimates radiometric response functions of all the nonlinear images up to a unique exponential ambiguity using a rank minimization framework. The ambiguity is then resolved using the linear edge color blending constraint. Quantitative evaluation using both synthetic and real-world data shows the effectiveness of the proposed method.

We present a method for geometric point light source calibration. Unlike prior works that use Lambertian spheres, mirror spheres, or mirror planes, we use a calibration target consisting of a plane and small shadow casters at unknown positions above the plane. We show that shadow observations from a moving calibration target under a fixed light follow the principles of pinhole camera geometry and epipolar geometry, allowing joint recovery of the light position and 3D shadow caster positions, equivalent to how conventional structure from motion jointly recovers camera parameters and 3D feature positions from observed 2D features. Moreover, we devised a unified light model that works with nearby point lights as well as distant light in one common framework. Our evaluation shows that our method yields light estimates that are stable and more accurate than existing techniques while having a much simpler setup and requiring less manual labor.