252 research outputs found

    Efficient Region-Aware Neural Radiance Fields for High-Fidelity Talking Portrait Synthesis

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    This paper presents ER-NeRF, a novel conditional Neural Radiance Fields (NeRF) based architecture for talking portrait synthesis that can concurrently achieve fast convergence, real-time rendering, and state-of-the-art performance with small model size. Our idea is to explicitly exploit the unequal contribution of spatial regions to guide talking portrait modeling. Specifically, to improve the accuracy of dynamic head reconstruction, a compact and expressive NeRF-based Tri-Plane Hash Representation is introduced by pruning empty spatial regions with three planar hash encoders. For speech audio, we propose a Region Attention Module to generate region-aware condition feature via an attention mechanism. Different from existing methods that utilize an MLP-based encoder to learn the cross-modal relation implicitly, the attention mechanism builds an explicit connection between audio features and spatial regions to capture the priors of local motions. Moreover, a direct and fast Adaptive Pose Encoding is introduced to optimize the head-torso separation problem by mapping the complex transformation of the head pose into spatial coordinates. Extensive experiments demonstrate that our method renders better high-fidelity and audio-lips synchronized talking portrait videos, with realistic details and high efficiency compared to previous methods.Comment: Accepted by ICCV 202

    Regulations of the key mediators in inflammation and atherosclerosis by Aspirin in human macrophages

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    Although its role to prevent secondary cardiovascular complications has been well established, how acetyl salicylic acid (ASA, aspirin) regulates certain key molecules in the atherogenesis is still not known. Considering the role of matrix metalloproteinase-9 (MMP-9) to destabilize the atherosclerotic plaques, the roles of the scavenger receptor class BI (SR-BI) and ATP-binding cassette transporter A1 (ABCA1) to promote cholesterol efflux in the foam cells at the plaques, and the role of NF-κB in the overall inflammation related to the atherosclerosis, we addressed whether these molecules are all related to a common mechanism that may be regulated by acetyl salicylic acid. We investigated the effect of ASA to regulate the expressions and activities of these molecules in THP-1 macrophages. Our results showed that ASA inhibited MMP-9 mRNA expression, and caused the decrease in the MMP-9 activities from the cell culture supernatants. In addition, it inhibited the nuclear translocation of NF-κB p65 subunit, thus the activity of this inflammatory molecule. On the contrary, acetyl salicylic acid induced the expressions of ABCA1 and SR-BI, two molecules known to reduce the progression of atherosclerosis, at both mRNA and protein levels. It also stimulated the cholesterol efflux out of macrophages. These data suggest that acetyl salicylic acid may alleviate symptoms of atherosclerosis by two potential mechanisms: maintaining the plaque stability via inhibiting activities of inflammatory molecules MMP-9 and NF-κB, and increasing the cholesterol efflux through inducing expressions of ABCA1 and SR-BI

    STPrivacy: Spatio-Temporal Privacy-Preserving Action Recognition

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    Existing methods of privacy-preserving action recognition (PPAR) mainly focus on frame-level (spatial) privacy removal through 2D CNNs. Unfortunately, they have two major drawbacks. First, they may compromise temporal dynamics in input videos, which are critical for accurate action recognition. Second, they are vulnerable to practical attacking scenarios where attackers probe for privacy from an entire video rather than individual frames. To address these issues, we propose a novel framework STPrivacy to perform video-level PPAR. For the first time, we introduce vision Transformers into PPAR by treating a video as a tubelet sequence, and accordingly design two complementary mechanisms, i.e., sparsification and anonymization, to remove privacy from a spatio-temporal perspective. In specific, our privacy sparsification mechanism applies adaptive token selection to abandon action-irrelevant tubelets. Then, our anonymization mechanism implicitly manipulates the remaining action-tubelets to erase privacy in the embedding space through adversarial learning. These mechanisms provide significant advantages in terms of privacy preservation for human eyes and action-privacy trade-off adjustment during deployment. We additionally contribute the first two large-scale PPAR benchmarks, VP-HMDB51 and VP-UCF101, to the community. Extensive evaluations on them, as well as two other tasks, validate the effectiveness and generalization capability of our framework

    MangaGAN: Unpaired Photo-to-Manga Translation Based on The Methodology of Manga Drawing

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    Manga is a world popular comic form originated in Japan, which typically employs black-and-white stroke lines and geometric exaggeration to describe humans' appearances, poses, and actions. In this paper, we propose MangaGAN, the first method based on Generative Adversarial Network (GAN) for unpaired photo-to-manga translation. Inspired by how experienced manga artists draw manga, MangaGAN generates the geometric features of manga face by a designed GAN model and delicately translates each facial region into the manga domain by a tailored multi-GANs architecture. For training MangaGAN, we construct a new dataset collected from a popular manga work, containing manga facial features, landmarks, bodies, and so on. Moreover, to produce high-quality manga faces, we further propose a structural smoothing loss to smooth stroke-lines and avoid noisy pixels, and a similarity preserving module to improve the similarity between domains of photo and manga. Extensive experiments show that MangaGAN can produce high-quality manga faces which preserve both the facial similarity and a popular manga style, and outperforms other related state-of-the-art methods.Comment: 17 page

    Nomogram based on computed tomography images and clinical data for distinguishing between primary intestinal lymphoma and Crohn’s disease: a retrospective multicenter study

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    BackgroundDifferential diagnosis of primary intestinal lymphoma (PIL) and Crohn’s disease (CD) is a challenge in clinical diagnosis.AimsTo investigate the validity of the nomogram based on clinical and computed tomography (CT) features to identify PIL and CD.MethodsThis study retrospectively analyzed laboratory parameters, demographic characteristics, clinical manifestations, and CT imaging features of PIL and CD patients from two centers. Univariate logistic analysis was performed for each variable, and laboratory parameter model, clinical model and imaging features model were developed separately. Finally, a nomogram was established. All models were evaluated using the area under the curve (AUC), accuracy, sensitivity, specificity, and decision curve analysis (DCA).ResultsThis study collected data from 121 patients (PIL = 69, CD = 52) from Center 1. Data from 43 patients (PIL = 24, CD = 19) were collected at Center 2 as an external validation cohort to validate the robustness of the model. Three models and a nomogram were developed to distinguish PIL from CD. Most models performed well from the external validation cohort. The nomogram showed the best performance with an AUC of 0.921 (95% CI: 0.838–1.000) and sensitivities, specificities, and accuracies of 0.945, 0.792, and 0.860, respectively.ConclusionA nomogram combining clinical data and imaging features was constructed, which can effectively distinguish PIL from CD

    Didymin improves UV irradiation resistance in C. elegans

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    Didymin, a type of flavono-o-glycoside compound naturally present in citrus fruits, has been reported to be an effective anticancer agent. However, its effects on stress resistance are unclear. In this study, we treated Caenorhabditis elegans with didymin at several concentrations. We found that didymin reduced the effects of UV stressor on nematodes by decreasing reactive oxygen species levels and increasing superoxide dismutase (SOD) activity. Furthermore, we found that specific didymin-treated mutant nematodes daf-16(mu86) & daf-2(e1370), daf-16(mu86), akt-1(ok525), akt-2(ok393), and age-1(hx546) were susceptible to UV irradiation, whereas daf-2(e1371) was resistant to UV irradiation. In addition, we found that didymin not only promoted DAF-16 to transfer from cytoplasm to nucleus, but also increased both protein and mRNA expression levels of SOD-3 and HSP-16.2 after UV irradiation. Our results show that didymin affects UV irradiation resistance and it may act on daf-2 to regulate downstream genes through the insulin/IGF-1-like signaling pathway

    Iliopsoas fibrosis after revision of total hip arthroplasty revealed by 68Ga-FAPI PET/CT: a case report

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    BackgroundTotal hip arthroplasty (THA) is a well-established surgical procedure that has been extensively validated to alleviate pain, enhance joint function, improve the ability to perform daily activities, and enhance overall quality of life. However, this procedure is associated with certain complications, among which skeletal muscle fibrosis is a frequently overlooked but significant complication that can lead to persistent pain. Currently, there is no effective method for diagnosing skeletal muscle fibrosis following total hip arthroplasty.Case reportWe report a 75-year-old male patient who complained of left groin pain after revision total hip arthroplasty. Serological examinations, X-rays, and bone scan results were all normal. However, during the 68Ga-FAPI PET/CT examination, we observed significant radiotracer uptake along the iliopsoas muscle. This abnormal uptake pattern suggested potential biological activity in this specific area. Combined with physical examination, the patient was diagnosed with iliopsoas fibrosis.ConclusionsThe presented images indicated that the uptake pattern was an important indicator for diagnosis, and the prospect of fibroblast activation protein in the diagnosis of skeletal muscle fibrosis has shown certain application value

    Controlled Atmosphere Storage Alleviates Chilling Injury and Ameliorates Aroma Quality by Enhancing Reactive Oxygen Species Scavenging Ability in Peach Fruit

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    In order to explore the effect of controlled atmosphere (CA) storage on alleviating chilling injury (CI) in peach fruit and the possible underlying mechanism, the effect of CA treatment (5% O2 + 10% CO2) on internal browning index (IB), firmness, ethylene release rate, reactive oxygen species (ROS) content, malondialdehyde (MDA) content, compounds and key enzyme activities related to the ascorbic acid-glutathione (AsA-GSH) cycle and volatile contents in yellow-fleshed peach fruit (cv. Jinxiu) during low temperature ((0 ± 2) ℃) storage and shelf (20 ℃, 3 d) was investigated. The results showed that CA alleviated CI significantly relative to the control group; on the third day of the shelf life after 30-day cold storage (30dS3), IB was lower than 10%, fruit firmness decreased to below 10 N, and ethylene release rate was 1.7-fold as high as in the control. During the late period of cold storage, the contents of total ROS, MDA, and hydrogen peroxide (H2O2) were significantly lower and scavenging capacities against 1,1-diphenyl-lpicrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation free radicals were significantly higher in the CA-treated fruit than the control group (P < 0.05 or P < 0.01). Meanwhile, in the CA-treated peach fruit, the activity of superoxide dismutase (SOD) was increased by 36% on 30dS3, while the activities of AsA-GSH cycle-related key enzymes such as ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR) and monodehydroascorbate reductase (MDHAR) were enhanced, and the conversion of reduced ascorbic acid to dehydroascorbic acid was significantly inhibited. Moreover, CA treatment accumulated higher amounts of C6 alcohols, esters, and lactones compared with the control group at the end of the shelf life; on 30dS3, the contents of γ-hexalactone, γ-decalactone, and δ-decalactone were increased by 3.0, 2.6 and 5.0 folds compared with the control group, respectively. In addition, higher contents of sucrose and sorbitol and lower contents of glucose and fructose were observed in the CA-treated fruit. Therefore, CA treatment (5% O2 + 10% CO2) can alleviate CI and maintain aroma quality by activating the AsA-GSH cycle and SOD, and enhancing ROS scavenging capacity in peach fruit
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