232 research outputs found

    Event-Guided Procedure Planning from Instructional Videos with Text Supervision

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    In this work, we focus on the task of procedure planning from instructional videos with text supervision, where a model aims to predict an action sequence to transform the initial visual state into the goal visual state. A critical challenge of this task is the large semantic gap between observed visual states and unobserved intermediate actions, which is ignored by previous works. Specifically, this semantic gap refers to that the contents in the observed visual states are semantically different from the elements of some action text labels in a procedure. To bridge this semantic gap, we propose a novel event-guided paradigm, which first infers events from the observed states and then plans out actions based on both the states and predicted events. Our inspiration comes from that planning a procedure from an instructional video is to complete a specific event and a specific event usually involves specific actions. Based on the proposed paradigm, we contribute an Event-guided Prompting-based Procedure Planning (E3P) model, which encodes event information into the sequential modeling process to support procedure planning. To further consider the strong action associations within each event, our E3P adopts a mask-and-predict approach for relation mining, incorporating a probabilistic masking scheme for regularization. Extensive experiments on three datasets demonstrate the effectiveness of our proposed model.Comment: Accepted to ICCV 202

    Diversifying Spatial-Temporal Perception for Video Domain Generalization

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    Video domain generalization aims to learn generalizable video classification models for unseen target domains by training in a source domain. A critical challenge of video domain generalization is to defend against the heavy reliance on domain-specific cues extracted from the source domain when recognizing target videos. To this end, we propose to perceive diverse spatial-temporal cues in videos, aiming to discover potential domain-invariant cues in addition to domain-specific cues. We contribute a novel model named Spatial-Temporal Diversification Network (STDN), which improves the diversity from both space and time dimensions of video data. First, our STDN proposes to discover various types of spatial cues within individual frames by spatial grouping. Then, our STDN proposes to explicitly model spatial-temporal dependencies between video contents at multiple space-time scales by spatial-temporal relation modeling. Extensive experiments on three benchmarks of different types demonstrate the effectiveness and versatility of our approach.Comment: Accepted to NeurIPS 2023. Code is available at https://github.com/KunyuLin/STDN

    Insulin resistance predicts progression of de novo atherosclerotic plaques in patients with coronary heart disease: a one-year follow-up study

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    BACKGROUND: The aim of our study was to explore and evaluate the relationship between insulin resistance and progression of coronary atherosclerotic plaques. With the great burden coronary heart disease is imposing on individuals, healthcare professionals have already embarked on determining its potential modifiable risk factors in the light of preventive medicine. Insulin resistance has been generally recognized as a novel risk factor based on epidemiological studies; however, few researches have focused on its effect on coronary atherosclerotic plaque progression. METHODS: From June 7, 2007 to December 30, 2011, 366 patients received their index coronary angiogram and were subsequently found to have coronary atherosclerotic plaques or normal angiograms were consecutively enrolled in the study by the department of cardiology at the Ruijin Hospital, which is affiliated to the Shanghai Jiaotong University School of Medicine. All patients had follow-up angiograms after the 1-year period for evaluating the progression of the coronary lesions. The modified Gensini score was adopted for assessing coronary lesions while the HOMA-IR method was utilized for determining the state of their insulin resistance. Baseline characteristics and laboratory test results were described and the binomial regression analysis was conducted to investigate the relationship between insulin resistance and coronary atherosclerotic plaque progression. RESULTS: Index and follow-up Gensini scores were similar between the higher insulin lower insulin resistant groups (9.09 ± 14.33 vs 9.44 ± 12.88, p = 0.813 and 17.21 ± 18.46 vs 14.09 ± 14.18, p =0.358). However the Gensini score assessing coronary lesion progression between both visits was significantly elevated in the higher insulin resistant group (8.13 ± 11.83 versus 4.65 ± 7.58, p = 0.019). Multivariate logistic binomial regression analysis revealed that insulin resistance (HOMA-IR > 3.4583) was an independent predictor for coronary arterial plaque progression (OR = 4.969, p = 0.011). We also divided all the participants into a diabetic (n = 136) and a non-diabetic group (n = 230), and HOMA-IR remained an independent predictor for atherosclerosis plaque progression. CONCLUSIONS: Insulin resistance is an independent predictor of atherosclerosis plaque progression in patients with coronary heart disease in both the diabetic and non-diabetic population

    The Static and Dynamic Mechanical Properties of Magnetorheological Silly Putty

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    A novel magnetorheological material defined as magnetorheological Silly Putty (MRSP) is prepared by dispersing soft magnetic particles into Silly Putty matrix with shear stiffening property. Static mechanical properties including creep and stress relaxation and dynamic rheological properties of MRSPs are tested by rheometer. The experimental results indicate that the external magnetic field exerts significant influence on the creep and relaxation behaviors. Moreover, the storage modulus of MRSPs increases sharply in response to the external stimuli of increasing angular frequency automatically and can be enhanced by external magnetic field. Besides, temperature plays a key role in shear stiffening and magnetorheological effect of MRSPs. Furthermore, considering the obstruction to the particle chains formation induced by Silly Putty matrix, a nonperforative particle aggregated chains model is proposed. The model curve is in consistency with experimental data, which means it can describe magnetoinduced behavior of MRSPs well

    Performance of Variable Negative Stiffness MRE Vibration Isolation System

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    Magnetorheological elastomer (MRE) vibration isolation devices can improve a system’s vibration response via adjustable stiffness and damping under different magnetic fields. Combined with negative stiffness design, these MRE devices can reduce a system’s stiffness and improve the vibration control effect significantly. This paper develops a variable negative stiffness MRE isolation device by combining an improved separable iron core with laminated MREs. The relationship between the negative stiffness and the performance of the device is obtained by mathematical transformation. Its vibration response under simple harmonic excitation at small amplitude and the impact of the volume fraction of soft magnetic particles on the isolation system are also analyzed. The results show that the negative stiffness produced by the magnetic force is a major factor affecting the capacity of the isolation system. Compared to devices of the same size, the isolation system equipped with low-particle volume fraction MREs demonstrates better performance

    [68Ga]Ga-DOTA-FAPI-04 PET/MR in patients with acute myocardial infarction: potential role of predicting left ventricular remodeling.

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    PURPOSE To assess predictive value of 68Ga-labeled fibroblast activation protein inhibitor-04 ([68Ga]Ga-DOTA-FAPI-04) PET/MR for late left ventricular (LV) remodeling in patients with ST-segment elevated myocardial infarction (STEMI). METHODS Twenty-six patients with STEMI were included in the study. [68Ga]Ga-DOTA-FAPI-04 PET/MR was performed at baseline and at average 12 months after STEMI. LV remodeling was defined as >10% increase in LV end-systolic volume (LVESV) from baseline to 12 months. RESULTS The LV remodeling group demonstrated higher [68Ga]Ga-DOTA-FAPI-04 uptake volume (UV) at baseline than the non-LV remodeling group (p < 0.001). [68Ga]Ga-DOTA-FAPI-04 UV at baseline was a significant predictor (OR = 1.048, p = 0.011) for LV remodeling at 12 months after STEMI. Compared to clinical information, MR imaging and cardiac function parameters at baseline, [68Ga]Ga-DOTA-FAPI-04 UV demonstrated better predictive ability (AUC = 0.938, p < 0.001) for late LV remodeling, with sensitivity of 100.0% and specificity of 81.3%. CONCLUSIONS [68Ga]Ga-DOTA-FAPI-04 PET/MR is an effective tool to non-invasively quantify myocardial fibroblasts activation, and baseline [68Ga]Ga-DOTA-FAPI-04 UV may have potential predictive value for late LV remodeling

    Outcomes and prognostic factors for patients with cervical esophageal cancer undergoing definitive radiotherapy or chemoradiotherapy

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    Cervical esophageal cancer (CEC) is uncommon, accounting for less than 5% of all esophageal cancers. The management of CEC is controversial. This study investigated treatment outcomes and prognostic factors of survival in CEC patients undergoing definitive radiotherapy or concurrent chemoradiotherapy (CCRT). Ninety-one CEC patients were treated by intensity-modulated radiation therapy (IMRT) and three-dimensional conformal radiation therapy (3DCRT) between July 2007 and September 2017. The mean prescription dose was 64 Gy (range 54-70 Gy) delivered as 1.8-2.2 Gy per fraction per day, 5 days a week. Out of 91 patients, 34 received concurrent cisplatin-based chemotherapy (CT) including 18 patients who also received neoadjuvant CT. Overall survival (OS), locoregional failure-free survival (LRFFS), and progression-free survival (PFS) were estimated by the Kaplan–Meier method. Prognostic factors of survival were determined in univariate (log-rank test) and multivariate (Cox proportional hazard model) analysis. Treatment-related toxicity was also assessed. Median follow-up time for all patients was 19 months. Two-year OS, LRFFS and PFS of all patients were 58.2%, 52.5% and 48.1%, respectively. Clinical stage was an independent prognostic factor for OS (HR = 2.35, 95% CI: 1.03-5.37, p = 0.042), LRFFS (HR = 3.84, 95% CI: 1.38-10.69, p = 0.011), and PFS (HR = 2.68, 95% CI: 1.11-6.45, p = 0.028). Hoarseness was an independent prognostic factor for OS (HR = 2.10, 95% CI: 1.05-4.19, p = 0.036). CCRT was independently associated with better LRFFS (HR = 0.33, 95% CI: 0.14-0.79, p = 0.012). 3DCRT and IMRT with concurrent CT is well-tolerated and may improve local tumor control in CEC patients. Advanced clinical stage and hoarseness are adverse prognostic factors for OS, LRFFS, and PFS in CEC

    Cooperation in the snowdrift game on directed small-world networks under self-questioning and noisy conditions

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    Cooperation in the evolutionary snowdrift game with a self-questioning updating mechanism is studied on annealed and quenched small-world networks with directed couplings. Around the payoff parameter value r=0.5r=0.5, we find a size-invariant symmetrical cooperation effect. While generally suppressing cooperation for r>0.5r>0.5 payoffs, rewired networks facilitated cooperative behavior for r<0.5r<0.5. Fair amounts of noise were found to break the observed symmetry and further weaken cooperation at relatively large values of rr. However, in the absence of noise, the self-questioning mechanism recovers symmetrical behavior and elevates altruism even under large-reward conditions. Our results suggest that an updating mechanism of this type is necessary to stabilize cooperation in a spatially structured environment which is otherwise detrimental to cooperative behavior, especially at high cost-to-benefit ratios. Additionally, we employ component and local stability analyses to better understand the nature of the manifested dynamics.Comment: 7 pages, 6 figures, 1 tabl

    Iridium(III) complex-based activatable probe for phosphorescent/time-gated luminescent sensing and imaging of cysteine in mitochondria of live cells and animals

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    This study reports an activatable iridium(III) complex probe for phosphorescence/time-gated luminescence detection of cysteine (Cys) in vitro and in vivo. The probe, [Ir(ppy)2(NTY-bpy)](PF6), is developed by incorporating a strong electron withdrawing group, nitroolefin, into a bipyridine ligand of the Ir(III) complex. The luminescence of the probe is quenched due to the intramolecular charge transfer (ICT) process, but switched on by a specific recognition reaction between the probe and Cys. [Ir(ppy)2(NTY-bpy)](PF6) shows high sensitivity and selectivity for Cys detection and good biocompatibility. The long-lived emission of [Ir(ppy)2(NTY-bpy)](PF6) allows time-gated luminescence analysis of Cys in cells and human sera. These properties make it convenient for the phosphorescence and time-gated luminescence imaging and flow cytometry analysis of Cys in live samples. The Cys images in cancer cells and inflamed macrophage cells reveal that [Ir(ppy)2(NTY-bpy)](PF6) is distributed in mitochondria after cellular internalization. Visualizations and flow cytometry analysis of mitochondrial Cys levels and Cys-mediated redox activities of live cells are achieved. Using [Ir(ppy)2(NTY-bpy)](PF6) as a probe, in vivo sensing and imaging of Cys in D. magna, zebrafish, and mice are then demonstrated
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