Dolfin: Diffusion Layout Transformers without Autoencoder

In this paper, we introduce a novel generative model, Diffusion Layout Transformers without Autoencoder (Dolfin), which significantly improves the modeling capability with reduced complexity compared to existing methods. Dolfin employs a Transformer-based diffusion process to model layout generation. In addition to an efficient bi-directional (non-causal joint) sequence representation, we further propose an autoregressive diffusion model (Dolfin-AR) that is especially adept at capturing rich semantic correlations for the neighboring objects, such as alignment, size, and overlap. When evaluated against standard generative layout benchmarks, Dolfin notably improves performance across various metrics (fid, alignment, overlap, MaxIoU and DocSim scores), enhancing transparency and interoperability in the process. Moreover, Dolfin's applications extend beyond layout generation, making it suitable for modeling geometric structures, such as line segments. Our experiments present both qualitative and quantitative results to demonstrate the advantages of Dolfin

ProposalContrast: Unsupervised Pre-training for LiDAR-based 3D Object Detection

Existing approaches for unsupervised point cloud pre-training are constrained to either scene-level or point/voxel-level instance discrimination. Scene-level methods tend to lose local details that are crucial for recognizing the road objects, while point/voxel-level methods inherently suffer from limited receptive field that is incapable of perceiving large objects or context environments. Considering region-level representations are more suitable for 3D object detection, we devise a new unsupervised point cloud pre-training framework, called ProposalContrast, that learns robust 3D representations by contrasting region proposals. Specifically, with an exhaustive set of region proposals sampled from each point cloud, geometric point relations within each proposal are modeled for creating expressive proposal representations. To better accommodate 3D detection properties, ProposalContrast optimizes with both inter-cluster and inter-proposal separation, i.e., sharpening the discriminativeness of proposal representations across semantic classes and object instances. The generalizability and transferability of ProposalContrast are verified on various 3D detectors (i.e., PV-RCNN, CenterPoint, PointPillars and PointRCNN) and datasets (i.e., KITTI, Waymo and ONCE).Comment: Accepted to ECCV 2022. Code: https://github.com/yinjunbo/ProposalContras

In Situ Stress Distribution and Its Control on the Coalbed Methane Reservoir Permeability in Liulin Area, Eastern Ordos Basin, China

Permeability is one of the important factors that affect the production efficiency of coalbed methane, and it is mainly controlled by in situ stress. Therefore, it is very essential to study the in situ stress and permeability for the extraction of coalbed methane. Based on the injection/falloff well test and in situ stress measurement of 35 coalbed methane wells in the Liulin area in the east of the Ordos basin, the correlations between initial reservoir pressure, in situ stress, lateral stress coefficient, permeability, and burial depth were determined. Finally, the distribution characteristics of in situ stress and its influence on permeability were analyzed systematically. The results show that with the increase of burial depth, the initial reservoir pressure and in situ stress both increase, while the lateral stress coefficient decreases. The permeability variation is related to the type of stress field in different burial depths, and its essence is the deformation and destruction of coal pore structures caused by stress. The distribution characteristics of in situ stress at different depths and its effect on permeability are as follows: at depthsσh) and the permeability is a simple decreasing process with the increase of the depth; at depths>800 m, the vertical stress is dominant (σv≥σH>σh). The permeability of most coal is very small due to the large in situ stresses in this depth zone. However, because of the stress release at the syncline axis, coal with high permeability is still possible at this depth zone. Due to the existence of high permeability data points at burial depth (>800 m) and the fitting relationship between permeability and vertical stress, the maximum and minimum horizontal principal stress is poor. However, the coal permeability and lateral stress coefficient show a good negative exponential relationship. This indicates that the lateral stress coefficient can be used to predict permeability better

Periodontitis was associated with mesial concavity of the maxillary first premolar: a cross-sectional study

Abstract The association between the anatomical features of teeth and the pathogenesis of periodontitis is well-documented. This study aimed to evaluate the influence of the mesial concavity of the maxillary first premolar on periodontal clinical indices and alveolar bone resorption rates. Employing a cross-sectional design, in 226 patients with periodontitis, we used cone beam computed tomography(CBCT) to examine the mesial concavity and alveolar bone resorption of 343 maxillary first premolar. Periodontal clinical indicators recorded by periodontal probing in the mesial of the maxillary first premolar in patients with periodontitis. Our findings indicate that the presence of mesial concavity at the cemento-enamel junction of the maxillary first premolar was not significantly influenced by either tooth position or patient sex (p > 0.05). Nonetheless, the mesial concavity at the cemento-enamel junction of the maxillary first premolar was found to exacerbate alveolar bone resorption and the inflammatory condition (p < 0.05). We infer that the mesial concavity at the cemento-enamel junction of the maxillary first premolar may contribute to localized alveolar bone loss and accelerate the progression of periodontal disease

Boosting Adsorption Isosteric Heat for Improved Gravimetric and Volumetric Hydrogen Uptake in Porous Carbon by N‑Doping

Porous carbon materials (PCMs) hold great promise as hydrogen storage materials due to their high capacity but are limited by adsorbing H2 at either cryogenic temperature or very high H2 pressure due to their weak van der Waals forces with the H2 molecules. In this study, N-doped hierarchical porous carbon (NHPC) materials were prepared by a simple one-step chemical activation method. Experimental results reveal that N-doping significantly enhances the interaction between H2 and the PCMs, which is demonstrated by increased adsorption isosteric heat (Qst) and H2 storage capacity per specific surface area (SSA). At lower H2 coverage, the Qst increases from 7.45 kJ/mol (NHPC-0) to 7.95 kJ/mol (NHPC-2 and NHPC-3), which aligns with the enhanced gravimetric H2 uptake per SSA. At higher H2 coverage (77 K, 50 bar-H2), there is a notable enhancement in the volumetric H2 uptake per SSA for NHPC-3 (11.41 g·L–1/m2·g–1) compared to that for NHPC-0 (8.49 g·L–1/m2·g–1) as the N content increases. Furthermore, N-doping can increase the packing density, thereby improving the volumetric H2 storage capacity of NHPC-x. The enhancement is strikingly demonstrated by NHPC-2, which achieves a volumetric H2 uptake of 26.96 g/L (SSA = 2458.44 m2/g) at 77 K and 50 bar. This is almost the same as that for NHPC-0, despite a 21% reduction in SSA, which is 26.47 g/L (SSA = 3116.58 m2/g) at the same condition. This work contributes to a deeper understanding of the effect of heteroatom doping on the H2 storage performance in PCMs

Biphasic effects of TGFβ1 on BMP9-induced osteogenic differentiation of mesenchymal stem cells

We have found that the previously uncharacterized bone morphogeneticprotein-9 (BMP9) is one of the most osteogenic factors.However, it is unclear if BMP9 cross-talks with TGFβ1 during osteogenicdifferentiation. Using the recombinant BMP9 adenovirus,we find that low concentration of rhTGFβ1 synergistically inducesalkaline phosphatase activity in BMP9-transduced C3H10T1/2cells and produces more pronounced matrix mineralization.However, higher concentrations of TGFβ1 inhibit BMP9-inducedosteogenic activity. Real-time PCR and Western blotting indicatethat BMP9 in combination with low dose of TGFβ1 potentiates theexpression of later osteogenic markers osteopontin, osteocalcinand collagen type 1 (COL1a2), while higher concentrations ofTGFβ1 decrease the expression of osteopontin and osteocalcin butnot COL1a2. Cell cycle analysis reveals that TGFβ1 inhibitsC3H10T1/2 proliferation in BMP9-induced osteogenesis and restrictsthe cells in G0/G1 phase. Our findings strongly suggest thatTGFβ1 may exert a biphasic effect on BMP9-induced osteogenicdifferentiation of mesenchymal stem cells

Ethylene-regulated asymmetric growth of the petal base promotes flower opening in rose (Rosa hybrida)

Flowers are the core reproductive structures and key distinguishing features of angiosperms. Flower opening to expose stamens and gynoecia is important in cases where pollinators much be attracted to promote cross-pollination, which can enhance reproductive success and species preservation. The floral opening process is accompanied by the coordinated movement of various floral organs, particularly petals. However, the mechanisms underlying petal movement and flower opening are not well understood. Here, we integrated anatomical, physiological, and molecular approaches to determine the petal movement regulatory network using rose (Rosa hybrida) as a model. We found that PETAL MOVEMENT-RELATED PROTEIN1 (RhPMP1), a homeodomain transcription factor (TF) gene, is a direct target of ETHYLENE INSENSITIVE3, a TF that functions downstream of ethylene signaling. RhPMP1 expression was upregulated by ethylene and specifically activated endoreduplication of parenchyma cells on the adaxial side of the petal (ADSP) base by inducing the expression of RhAPC3b, a gene encoding the core subunit of the Anaphase-Promoting Complex. Cell expansion of the parenchyma on the ADSP base was subsequently enhanced, thus resulting in asymmetric growth of the petal base, leading to the typical epinastic movement of petals and flower opening. These findings provide insights into the pathway regulating petal movement and associated flower-opening mechanisms.?