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3D object detection is important for various indoor applications to understand the environment. Previous voting-based methods voted on the center of each seed point, which may suffer from errors from background points or adjacent objects. And the size-fixed feature grouping module is unsuitable for indoor objects with variable sizes. In this paper, we propose a Size Adaptive Clustering method for 3D object detection in point clouds . First, we present a super-voting module to divide seed points into foreground and background points and perform enhanced voting on the foreground seeds. To create a good match for the feature clustering area and the size of an object, we design a size-adaptive clustering module to infer a clustering radius based on the seed-to-vote displacement offset. Finally, because indoor objects are highly related to spatial room layouts, a position-aware module is used to calculate aware weights among objects and enhance the features of occluded objects. Experiments show that our method outperforms VoteNet by a large margin on ScanNet V2 (mAP@0.250 +8.3%, mAP@0.50 +14.2%) and SUN RGB-D (mAP@0.250 +3.5%, mAP@0.50 +13.6%). The proposed method can detect indoor objects with variable sizes in high accuracy, and perform robustly in case of occluded objects. The code of 3DSAC will be available at github-3DSAC.

Introduction: Osteoblasts and osteoclasts are cells of osteoblastic origin, and are vital in homeostasis of the skeleton. miRs are important for functioning, survival and differentiation of osteoclasts. It has been reported previously that miR-23b-3p is involved in osteoporosis and in regulation of differentiation of osteoblasts. It is also involved in the process of bone formation. However, the role of miR-23b-3p in differentiation of osteoclasts remains unexplored. Material and methods: CSF-1 and ODF induced osteoclasts were used for the study. RNA isolation was done from TIB-71 cells. TRAP staining was done for TRAP-positive osteoclast formation. PIT assay for bone resorption was performed. For in vivo studies osteoclast-specific miR-23b-3p transgenic mice were developed. Results: The levels of miR-23b-3p were upregulated in bone marrow monocytes during osteoclastogenesis with colony stimulating factor-1 and osteoclast differentiation factor induction, which suggests that miR-23b-3p plays a crucial role in differentiation of osteoclasts. Over-expression of miR23b-3p in bone marrow monocytes leads to osteoclastogenesis, whereas the inhibition ameliorates it. We further studied the function of miR-23b-3p via PI3K/AKT targeting the PTEN pathway. In vivo, osteoclast-specific miR23b-3p transgenic mice showed suppressed PTEN and elevated osteoclast activity, and the mice showed decreased bone mineral density. Conclusions: The results suggest that miR-23b-3p regulates the differentiation of osteoclasts by targeting PTEN through the PI3K/AKT cascade. [ABSTRACT FROM AUTHOR]

In order to explore the effect of nano Mg(OH)2(MH) on the flame retardancy and mechanical properties of nitrile-butadiene rubber (NBR) composite, molecular simulation was employed to examine the following properties of nano-MH/NBR composite, including thermal decomposition temperature, agglomeration and dispersion mechanism, shear behavior, stretcher strain and gyration radius of gyration. Discussion was performed on the microscopic mechanism of the flame retardancy and mechanical properties of nano MH/NBR composite. The simulation results indicated that the introduction of nano MH increased the thermal decomposition temperature of the composites by up to 28.92%, and that compared with the unmodified nano-MH/NBR composite, the thermal decomposition temperature of the conventionally-modified composite was increased by 19.22%. Besides, the crystal morphology, polarity and dispersion of nano-MH could be well optimized by hydrothermal modification. The Young’s modulus of the composite was increased by 35.65% by adding nano-MH into pure NBR. The Young’s modulus of the conventionally-modified nano-MH(101)/NBR and the hydrothermally-modified nano-MH(001)/NBR composite was 20.93 GPa and 21.43 GPa, respectively, an increase of 35.82% and 39.06% compared with unmodified nano-MH/NBR composite, respectively. To conclude, adding nano-MH could improve the flame retardancy and mechanical properties of NBR composite, and modified nano-MH performed better than unmodified nano-MH in NBR composite. [ABSTRACT FROM AUTHOR]