18 research outputs found

    SSD-MonoDETR: Supervised Scale-aware Deformable Transformer for Monocular 3D Object Detection

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    Transformer-based methods have demonstrated superior performance for monocular 3D object detection recently, which aims at predicting 3D attributes from a single 2D image. Most existing transformer-based methods leverage both visual and depth representations to explore valuable query points on objects, and the quality of the learned query points has a great impact on detection accuracy. Unfortunately, existing unsupervised attention mechanisms in transformers are prone to generate low-quality query features due to inaccurate receptive fields, especially on hard objects. To tackle this problem, this paper proposes a novel Supervised Scale-aware Deformable Attention (SSDA) for monocular 3D object detection. Specifically, SSDA presets several masks with different scales and utilizes depth and visual features to adaptively learn a scale-aware filter for object query augmentation. Imposing the scale awareness, SSDA could well predict the accurate receptive field of an object query to support robust query feature generation. Aside from this, SSDA is assigned with a Weighted Scale Matching (WSM) loss to supervise scale prediction, which presents more confident results as compared to the unsupervised attention mechanisms. Extensive experiments on the KITTI benchmark demonstrate that SSDA significantly improves the detection accuracy, especially on moderate and hard objects, yielding state-of-the-art performance as compared to the existing approaches. Our code will be made publicly available at https://github.com/mikasa3lili/SSD-MonoDETR.Comment: Code will be made publicly available at https://github.com/mikasa3lili/SSD-MonoDET

    Factors affecting the early establishment of neonatal intestinal flora and its intervention measures

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    In recent years, it has become evident that early-life intestinal flora plays a pivotal role in determining human health. Consequently, it is imperative to explore the establishment of neonatal intestinal flora and its influencing factors. Early neonatal intestinal flora is influenced by a multitude of factors, including maternal and infant-related factors, as well as external environment. This review summarizes the colonization mechanism of intestinal flora in the early life of newborns and discussed their influence on the establishment of neonatal intestinal flora, taking into account factors such as delivery mode, gestational age and feeding mode. Additionally, this review delves into the natural or artificial reconstruction of intestinal flora colonization defects in infants born via cesarean section and premature infants, with the goal of establishing a theoretical foundation for preventing and treating issues related to neonatal intestinal flora colonization and associated diseases

    Baiji genomes reveal low genetic variability and new insights into secondary aquatic adaptations

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    The baiji, or Yangtze River dolphin (Lipotes vexillifer), is a flagship species for the conservation of aquatic animals and ecosystems in the Yangtze River of China; however, this species has now been recognized as functionally extinct. Here we report a high-quality draft genome and three re-sequenced genomes of L. vexillifer using Illumina short-read sequencing technology. Comparative genomic analyses reveal that cetaceans have a slow molecular clock and molecular adaptations to their aquatic lifestyle. We also find a significantly lower number of heterozygous single nucleotide polymorphisms in the baiji compared to all other mammalian genomes reported thus far. A reconstruction of the demographic history of the baiji indicates that a bottleneck occurred near the end of the last deglaciation, a time coinciding with a rapid decrease in temperature and the rise of eustatic sea level

    Antiangiogenesis Roles of Exosomes with Fei-Liu-Ping Ointment Treatment are Involved in the Lung Carcinoma with the Lewis Xenograft Mouse Model

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    Exosomes display efficient biocompatibility and represent valuable vehicles for drug or effective material delivery in a tumour-therapeutic approach. Following treatment with Fei-Liu-Ping (FLP) ointment, a traditional Chinese herbal formula, which is used for treating lung cancer patients, could inhibit lung carcinoma growth in clinical and animal studies. In the present study, the values of VEGF and PDGF, which were closely related to angiogenesis, were estimated in serum and carcinoma tissue exosomes to unveil the FLP effects on angiogenesis. The common inflammatory factors of IL-6, IL-1β, TNF-α, and TGF-β in serum exosomes were also detected with the Lewis xenograft model. Methods. Male C57BL/6 mice were randomly divided into four groups, namely, normal, model, cyclophosphamide (CTX), and FLP treatment groups. Histological structures were observed and imaged by H&E. CD31 expressions in tumour tissues were detected by immunofluorescence (IF) and western blot (WB). VEGF, PDGF, and PDGFR levels in exosomes, serum, tumour, and lung tissues were detected by enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC), and WB, respectively. IL-6, IL-1β, TNF-α, and TGF-β levels in exosomes were measured by multiplex immunoassay panels. Results. The results showed that FLP had tumour growth inhibition rate (39.31%). CD31 protein expression was obviously decreased in tumour tissues of CTX- and FLP-treated MO mice, compared to that of MO mice (P<0.05 or P<0.001). VEGF, PDGF, and PDGFR expression levels with FLP treatment were downregulated in exosomes, serum, tumour, and lung tissues compared to model group (P<0.05 or P<0.01). The expressions of IL-6, IL-1β, and TNF-α were downregulated in exosomes compared to the model group (P<0.05 or P<0.01). Conclusions. This study suggested that FLP had the ability of inhibiting tumourigenesis in a Lewis lung xenograft mouse model, whose therapeutic mechanisms might relate with the downregulation of angiogenesis factor and tumour inflammatory cytokines levels

    Research of Low-Temperature Performance of Polyphosphoric Acid-Modified Asphalt

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    Polyphosphoric acid (PPA) modifier, which can effectively improve the rheological properties of asphalt, is widely used in pavement engineering. In order to accurately evaluate the low-temperature performance of PPA-modified asphalt, in this study, PPA-modified asphalt and PPA/SBR-modified asphalt were prepared. The modification mechanism was explored by scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR). Bending Beam Rheology (BBR) test was carried out, and four indexes, including K index, viscous flow (η1), low-temperature integrated flexibility (Jc), and relaxation time (λ), were obtained by combining the Burgers model. The optimal low-temperature performance evaluation index of modified asphalt was determined by the analytic hierarchy process (AHP). The test results show that PPA addition to asphalt will produce chemical reactions, which can effectively improve the compatibility between SBR and neat asphalt. In the multi-index evaluation based on K, η1, Jc, and λ, the same optimum content of PPA was obtained. AHP analysis further demonstrates that Jc is the optimal evaluation index for laboratory research on the low-temperature performance of PPA-modified asphalt, and λ index is the ideal evaluation index for the low-temperature performance of asphalt in engineering applications

    Rhodium-Catalyzed Cyclization of Diynes with Nitrones: A Formal [2+2+5] Approach to Bridged Eight-Membered Heterocycles

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    N-aryl-substituted nitrones were employed as five-atom coupling partners in the rhodium-catalyzed cyclization with diynes. In this reaction, the nitrone moiety served as a directing group for the catalytic C-H activation of the N-aryl ring. This formal [2+2+5] approach allows rapid access to bridged eight-membered heterocycles with broad substrate scope. The results of this study may provide new insight into the chemistry of nitrones and find applications in the synthesis of other heterocycles

    Synthesis of Polyfluoroalkyl Cyclobutenes from 3‑Aza-1,5-enynes via an Aza-Claisen Rearrangement/Cyclization Cascade

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    A facile synthetic route to access polyfluoroalkyl functionalized cyclobutenes bearing an exo cyclic double bond from 3-aza-1,5-enynes is reported. The reaction proceeds via a thermal aza-Claisen rearrangement to give an allene-imine intermediate; subsequent cyclization affords the cyclobutene core. The kinetics of the transformation of starting material and the intermediate was studied by <sup>1</sup>H NMR spectroscopy, where a consecutive reaction was revealed
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