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Background The objective of this study was to establish a nomogram for predicting the overall survival (OS) of patients with acral lentiginous melanoma (ALM). Materials and Methods The study sample was selected from 1785 patients diagnosed with ALM from 2004 to 2015 in the Surveillance, Epidemiology, and End Results (SEER) database, and R software was used to divide patients into the training cohort and validation cohort at a ratio of 7: 3. Stepwise selection method in the Cox regression model was used in the training cohort to select predictive variables to construct the nomogram, and model validation parameters were used in the validation cohort to evaluate the performance of the nomogram. Results The nomogram showed that age at diagnosis had the greatest impact on OS in patients with ALM, followed by AJCC stage, surgical treatment, SEER stage, sex, race, and marital status. The index of concordance, area under the receiver operating characteristic curve, calibration plots, net reclassification improvement, integrated discrimination improvement, and decision curve analysis demonstrate the good performance of this nomogram. Conclusion The prognostic value of the nomogram is superior to that of the AJCC staging system alone, and it helps clinicians to better predict 3-, 5-, and 8-year OS in patients with ALM.

Tingting Yin,1,* Yuhui Zhao,1,* Ying Yang,1 Huaxiu Xu,1 Dongxiang Zheng,2 Jun Lyu,3 Guanglei Fu4 1School of Nursing, Jinan University, Guangzhou, People’s Republic of China; 2Department of Neurology, The First Affiliated Hospital of Jinan University, Guangzhou, People’s Republic of China; 3Clinical Research Department, The First Affiliated Hospital of Jinan University, Guangzhou, People’s Republic of China; 4Infectious Disease Department, The First Affiliated Hospital of Jinan University, Guangzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jun LyuClinical Research Department, The First Affiliated Hospital of Jinan University, Guangzhou, People’s Republic of ChinaTel +86 13922274169Email lyujun2020@jnu.edu.cnGuanglei FuInfectious Disease Department, The First Affiliated Hospital of Jinan University, Guangzhou, People’s Republic of ChinaTel +86 18922217029Email 1623805741@qq.comBackground: The objective of this study was to establish a nomogram for predicting the overall survival (OS) of patients with acral lentiginous melanoma (ALM).Materials and Methods: The study sample was selected from 1785 patients diagnosed with ALM from 2004 to 2015 in the Surveillance, Epidemiology, and End Results (SEER) database, and R software was used to divide patients into the training cohort and validation cohort at a ratio of 7: 3. Stepwise selection method in the Cox regression model was used in the training cohort to select predictive variables to construct the nomogram, and model validation parameters were used in the validation cohort to evaluate the performance of the nomogram.Results: The nomogram showed that age at diagnosis had the greatest impact on OS in patients with ALM, followed by AJCC stage, surgical treatment, SEER stage, sex, race, and marital status. The index of concordance, area under the receiver operating characteristic curve, calibration plots, net reclassification improvement, integrated discrimination improvement, and decision curve analysis demonstrate the good performance of this nomogram.Conclusion: The prognostic value of the nomogram is superior to that of the AJCC staging system alone, and it helps clinicians to better predict 3-, 5-, and 8-year OS in patients with ALM.Keywords: acral lentiginous melanoma, nomogram, overall survival, SEER

Purpose To explore the effect of in situ synthesized particulates on a zirconia surface on the bonding properties between zirconia and porcelain. Materials and methods Presintered yttrium-stabilized tetragonal zirconia (Y-TZP) was cut into slices and bars and polished with 1,200-grit silicon carbide abrasive paper. Samples were randomly divided into six groups (C, I1, I3, I5, I7, and I9) according to immersion time in hydrofluoric acid solution (0, 10, 30, 50, 70, and 90 seconds, respectively). Then, the samples were placed in calcium chloride solution for 90 seconds and dipped in sodium hydroxide solution at 80°C for 2 hours. After sintering, the surface topography and roughness were examined. After the porcelain was fired, the bonding interface was observed, and cross-sectional microhardness was measured. The shear bond strength of the zirconia to porcelain was evaluated, and failure modes were classified. A 3-point bending test was applied to confirm the effects of the treatment on the mechanical properties. The above data were statistically analyzed. Results Polycrystalline particulates were synthesized on the zirconia surface. The surface roughness values increased as the immersion time of the samples in hydrofluoric acid increased. The cross-sectional microhardness decreased gradually in the experimental groups. Group I7 showed an elevated bond strength (27.02 ± 2.44 MPa). Mainly mixed failure mode was obtained in the experimental groups. The Weibull characteristic strength for the experimental groups was higher than that of group C. The flexural strengths were not significantly different among the groups. Conclusions In situ synthesized polycrystalline particulates on zirconia could effectively improve the bonding between zirconia ceramics and porcelain without significantly decreasing the mechanical properties.

Objectives Pits and fissures sealing with flowable materials is a popular method for preventing caries in preventive dentistry while there is still microleakage existed. This in vitro study aimed to explore the effects of subpressure technique on the sealing ability of pit and fissure sealant. Materials and methods One hundred and forty-one extracted human premolars were collected in this study and treated with different pressure (atmosphere pressure as group C, −0.04 MPa as group S4 and −0.08 MPa as group S8). Thermocycling (×5000) was also performed. Penetration percentage, microleakage, cross-sectional microhardness (Knoop, KMH) and mineral loss were evaluated. Kappa tests, Friedman nonparametric and two-way ANOVA were used for data analysis. Results Penetration percentages of group S4 and S8 were significant higher compared to that of group C. Microleakage of groups was similar before thermocycling, while subpressure groups showed lower scale of microleakage after thermocycling. Data of KMH and mineral loss showed significant differences between subpressure and thermocycling groups. Significance Subpressure technique could increase the penetration of pit and fissure sealant, decrease microleakage and increase resistance of demineralization after thermocycling. This novel technique may have great potential for preventing from secondary caries.

This study aimed to investigate the effects of subpressure on the bond properties of total-etching adhesive to dentin. Thirty-six caries-free premolars were sectioned parallel to the occlusal plane and randomly divided into four groups (n = 9): a control group (C, no treatment) and three subpressure groups, which were treated under 0.8, 0.6 or 0.4 bar after applying adhesives, named S8, S6 and S4, respectively. Afterward, resin was bonded to the dentin surface, and 27 beams (1.0 mm × 1.0 mm) of each group were sectioned. One was selected to observe the bonding interface from each group by SEM. Each group was divided into two subgroups (n = 13): 24 hours of water storage (I) and 10,000 thermocycling (A). The microtensile bond strength (μTBS), failure modes and nanoleakage expression were evaluated. SEM results showed that the subpressure groups had longer and denser resin tags. The μTBS of the subpressure groups was higher than that of the control group (p

This study aims to investigate the effect of sandblasting on the surface roughness of zirconia and the shear bond strength of the veneering porcelain. Pre-sintered zirconia plates were prepared and divided into four groups. Group A were not treated at all; group B were first sandblasted under 0.2 MPa pressure and then densely sintered; group C and D were sintered first, and then sandblasted under 0.2 MPa and 0.4 MPa pressures respectively. Surface roughness was measured and 3D roughness was reconstructed for the specimens, which were also analyzed with X-ray diffractometry. Finally after veneering porcelain sintering, shear bond tests were conducted. Sandblasting zirconia before sintering significantly increased surface roughness and the shear bond strength between zirconia and veneering porcelain (p

This study aimed to improve Ti-porcelain bonding strength through SiO2 modifications. Wax patterns were coated with SiO2 mixed with tetraethoxy silane (group C), patterns without coating were used as controls and subdivided into sandblasting group (group S) and polishing group (group P). Castingsurfaces were analyzed with XRD, while Ti-ceramic interfaces were characterized using SEM/EDS. Metal-ceramic specimens were tested in three point bending, and characterizations were also analyzed with SEM/EDS of porcelain debonding surfaces. In group C, SiO2 and Ti5Si3 phases were observed; SEM micrograph showed that Ti-porcelain had a compacted interface, and EDS maps of the interface illustrated the diffusion of Si, Al, and Sn to Ti, and cohesive fracture within the bonding agent. The bond strength of group C was 39.04±5.0 MPa, which was 15% higher than that of group S and 32% higher than that of group P. SiO2 coating could improve Ti-porcelain bond strength.