This paper presents an efficient technique for performing a spatially inhomogeneous edge-preserving image smoothing, called fast global smoother. Focusing on sparse Laplacian matrices consisting of a data term and a prior term (typically defined using four or eight neighbors for 2D image), our approach efficiently solves such global objective functions. In particular, we approximate the solution of the memory-and computation-intensive large linear system, defined over a d-dimensional spatial domain, by solving a sequence of 1D subsystems. Our separable implementation enables applying a linear-time tridiagonal matrix algorithm to solve d three-point Laplacian matrices iteratively. Our approach combines the best of two paradigms, i.e., efficient edge-preserving filters and optimization-based smoothing. Our method has a comparable runtime to the fast edge-preserving filters, but its global optimization formulation overcomes many limitations of the local filtering approaches. Our method also achieves high-quality results as the state-of-the-art optimization-based techniques, but runs ∼10-30 times faster. Besides, considering the flexibility in defining an objective function, we further propose generalized fast algorithms that perform Lγ norm smoothing (0 < γ < 2) and support an aggregated (robust) data term for handling imprecise data constraints. We demonstrate the effectiveness and efficiency of our techniques in a range of image processing and computer graphics applications.

Objective: To evaluate the stability of nonsurgical miniscrew-assisted rapid maxillary expansion (MARME) in young adults with a transverse maxillary deficiency. Materials and Methods: From a total of 69 adult patients who underwent MARME followed by orthodontic treatment with a straight-wire appliance, 20 patients (mean age, 20.9 6 2.9 years) with follow-up records (mean, 30.2 6 13.2 months) after debonding were selected. Posteroanterior cephalometric records and dental casts were obtained at the initial examination (T0), immediately after MARME removal (T1), immediately after debonding (T2), and at posttreatment follow-up (T3). Results: Suture separation was observed in 86.96% of subjects (60/69). An increase in the maxillary width (J-J; 1.92 mm) accounted for 43.34% of the total expansion with regard to the intermolar width (IMW) increase (4.43 mm; P , .001) at T2. The amounts of J-J and IMW posttreatment changes were 20.07 mm (P . .05) and 20.42 mm (P 5 .01), respectively, during retention. The postexpansion change in middle alveolus width increased with age (P , .05). The postexpansion change of interpremolar width (IPMW) was positively correlated with the amount of IPMW expansion (P , .05) but not with IMW. The changes of the clinical crown heights in the maxillary canines, first premolars, and first molars were not significant at each time point. Conclusions: Nonsurgical MARME can be a clinically acceptable and stable treatment modality for young adults with a transverse maxillary deficiency. (Angle Orthod. 2016;86:713-720.)

Gradient surfaces are widely employed in biological studies for protein adsorption and cell attachment and growth. They also offer great potential in the areas of fluid flow and combinatorial experimental design for obtaining material properties and behaviors. Gradient surfaces are created with organosilanes by using the diffusion techniques proposed by Ewling and modified by Chaudhury. However, these techniques have limitations. They either generate a significant amount of organic waste or require well-controlled deposition conditions. In this paper, we propose a fast, convenient, reproducible, and inexpensive method that generates gradient surfaces with minimum waste generation. Particularly, we have adopted Whitesides's contact-printing technique to achieve a gradient by gradually varying the contact time over the contacted area using octadecyltrichlorosilane. Elastomeric stamps with different geometries and various radii of curvature are used to generate gradient surfaces at both millimeter and micrometer scales. With this approach, we are able to generate micrometer-scaled gradient surfaces with a gradient steepness 1−3 orders of magnitude higher than those generated using diffusion-based techniques. The energy gradient on these surfaces is verified by the dewetting of polymer (e.g., polystyrene) thin films and by the movement of picoliter and nanoliter water droplets on the surface devoid of other driving forces such as gravity, temperature gradients, or a pressure drop.

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Poly(methyl methacralyate) (PMMA) has long been used in dentistry as a base polymer for dentures, and it is recently being used for the 3D printing of dental materials. Despite its many advantages, its susceptibility to microbial colonization remains to be overcome. In this study, the interface between 3D-printed PMMA specimens and oral salivary biofilm was studied following the addition of zwitterionic materials, 2-methacryloyloxyethyl phosphorylcholine (MPC) or sulfobetaine methacrylate (SB). A significant reduction in bacterial and biofilm adhesions was observed following the addition of MPC or SB, owing to their protein-repellent properties, and there were no significant differences between the two test materials. Although the mechanical properties of the tested materials were degraded, the statistical value of the reduction was minimal and all the properties fulfilled the requirements set by the International Standard, ISO 20795-2. Additionally, both the test materials maintained their resistance to biofilm when subjected to hydrothermal fatigue, with no further deterioration of the mechanical properties. Thus, novel 3D-printable PMMA incorporated with MPC or SB shows durable oral salivary biofilm resistance with maintenance of the physical and mechanical properties.