Evaluation of the Accuracy, Reliability, and Reproducibility of Two Different 3D Face-Scanning Systems

Purpose: To compare the accuracy, reliability, and reproducibility of a structured light scanning system and a stereophotogrammetry scanning system on human faces. Materials and Methods: A total of 10 healthy volunteers were included in this study. After marking of facial anatomy points, their faces were scanned by a structured light scanning system and a stereophotogrammetry system, and three-dimensional (3D) images were reconstructed with corresponding software. For each volunteer, scanning was performed twice after calibration. Linear measurements were calculated and compared for the two scanning techniques with direct caliper measurements. Absolute errors (AE), absolute percentage errors (APE), and intraclass correlation coefficients (ICC) were chosen as indices to determine the accuracy, reliability, and reproducibility of the two systems. Results: There was no statistically significant difference among the three measuring techniques (.891 < P < .999). Both scanning systems demonstrated high accuracy (AE = 0.58 +/- 0.37 mm and APE = 1.11 +/- 0.73% for the structured light system; AE = 0.62 +/- 0.39 mm and APE 1.17 +/- 0.71% for the stereophotogrammetry system). The two systems demonstrated extremely high reliability compared to caliper measurement (0.982 < ICC < 0.998 for the structured light system; 0.984 < ICC < 0.999 for the stereophotogrammetry system). In addition, high reproducibility was observed with the two systems (0.981 < ICC < 0.999 for the structured light system; 0.984 < ICC < 1.000 for the stereophotogrammetry system). Conclusion: When applied in scanning and measuring human faces, the structured light scanning system and stereophotogrammetry scanning system both demonstrated high accuracy, reliability, and reproducibility.Program for New Century Excellent Talents in University from Ministry of Education [NCET-11-0026]; Construction Program for National Key Clinical Specialty from National Health and Family Planning Commission of China; Beijing Municipal Science and Technology Commission [Z141107002514158]SCI(E)[email protected]

Effects of Sodium Silicate on Flotation Separation of Sphalerite and Dolomite and Its Mechanism

Sphalerite often co-exists with dolomite, a carbonate mineral containing calcium and magnesium. In the flotation process of sphalerite, dolomite entering into the concentrate will have a considerable negative impact on the subsequent smelting. Therefore, the effects of sodium silicate on the flotation separation of sphalerite and dolomite and its mechanism were investigated in this study. It was found that alkaline conditions and the addition of sodium silicate were conducive to the flotation separation of sphalerite and dolomite. Under alkaline conditions, sodium silicate improved the hydrophobicity of sphalerite and the slurry turbidity. The yield stress and apparent viscosity were significantly reduced when dolomite was present in slurry. In addition, the surface electrical properties of dolomite shifted from positive to negative with an increase in the dosage of sodium silicate at pH 11, leading to electrostatic repulsion between sphalerite and dolomite. EDLVO results indicated that the total interaction energy between dolomite and sphalerite particles was repulsive when sodium silicate was present. This study provided a theoretical basis for the flotation separation of sphalerite and dolomite

A Novel Technology for the Recovery and Separation of Cassiterite- and Iron-Containing Minerals from Tin-Containing Tailing

Tin-containing tailing is classified as a solid waste, but it possesses valuable resources such as tin and iron. Tin-containing tailing exhibits a fine distribution and compact symbiosis of cassiterite- and iron-containing minerals. Therefore, it is difficult to recover and separate cassiterite- and iron-containing minerals using traditional mineral processing methods. The study proposed a novel technology involving pre-concentration, reduction roasting, and magnetic separation for the treatment of tin-containing tailings with a tin grade of 0.14% and an iron grade of 12.79%. The classification pre-concentration method was achieved using a combination of shaking tables, suspension vibration cone separators, and high-gradient magnetic separation with a magnetic field strength of 1.4 T. The discarded tailings ratio reached 73.56%. The gravity pre-enriched concentrates and magnetic pre-enriched concentrates underwent reduction roasting to facilitate the conversion of hematite and goethite into magnetite, respectively. The optimal conditions for reduction roasting of the gravity pre-enriched concentrate were a 10% lignite dosage, a roasting temperature of 650 °C, and a holding time of 80 min. The optimal conditions for reduction roasting of the magnetic pre-enriched concentrate were a 8% lignite dosage, a roasting temperature of 750 °C, and a holding time of 100 min. The reduction roasted products were treated using magnetic separation with a magnetic field strength of 0.16 T. Finally, a tin-rich middling with a tin grade of 2.93% and a recovery ratio of 70.88%, as well as an iron concentrate with an iron grade of 61.95% and a recovery ratio of 68.08% were obtained. The study achieved efficient recoveries of tin and iron from tin tailings, thereby presenting a novel approach for the utilization of resources in the tailing

LRRC15 promotes osteogenic differentiation of mesenchymal stem cells by modulating p65 cytoplasmic/nuclear translocation

Abstract Background Mesenchymal stem cells (MSCs) are a reliable resource for bone regeneration and tissue engineering, but the molecular mechanisms of differentiation remain unclear. The tumor antigen 15-leucine-rich repeat containing membrane protein (LRRC15) is a transmembrane protein demonstrated to play important roles in cancer. However, little is known about its role in osteogenesis. This study was to evaluate the functions of LRRC15 in osteogenic differentiation of MSCs. Methods Osteogenic-induction treatment and the ovariectomized (OVX) model were performed to investigate the potential relationship between LRRC15 and MSC osteogenesis. A loss-of-function study was used to explore the functions of LRRC15 in osteogenic differentiation of MSCs in vitro and in vivo. NF-κB pathway inhibitor BAY117082, siRNA, nucleocytoplasmic separation, and ChIP assays were performed to clarify the molecular mechanism of LRRC15 in bone regulation. Results Our results first demonstrated that LRRC15 expression was upregulated upon osteogenic induction, and the level of LRRC15 was significantly decreased in OVX mice. Both in-vitro and in-vivo experiments detected that LRRC15 was required for osteogenesis of MSCs. Mechanistically, LRRC15 inhibited transcription factor NF-κB signaling by affecting the subcellular localization of p65. Further studies indicated that LRRC15 regulated osteogenic differentiation in a p65-dependent manner. Conclusions Taken together, our findings reveal that LRRC15 is an essential regulator for osteogenesis of MSCs through modulating p65 cytoplasmic/nuclear translocation, and give a novel hint for MSC-mediated bone regeneration

SIRT6 promotes osteogenic differentiation of mesenchymal stem cells through BMP signaling

Abstract SIRT6 has been identified as an H3K9 deacetylase and a critical regulator of genome stability, telomere integrity, and metabolic homeostasis. Sirt6-deficient mice displayed dramatic phenotypes including profound lymphopenia, loss of subcutaneous fat, lordokyphosis and low bone marrow density. Here, we report that SIRT6 regulates osteogenic differentiation independent of its deacetylase activity in vitro. Further mechanistic studies showed that SIRT6 involves the cell fate determination by modulating bone morphogenetic protein (BMP) signaling. Unexpectedly, this modulation depends upon P300/CBP-associated factor (PCAF). In addition, we observed impaired SIRT6 expression in bone marrow mesenchymal stem cells and in bone sections of ovariectomized mice. Taken together, our present study provide new insights into mechanisms of SIRT6-regulated MSC function beyond its H3K9 deacetylase activity