853 research outputs found

    Quantum Manifestation of Elastic Constants in Nanostructures

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    Generally, there are two distinct effects in modifying the properties of low-dimensional nanostructures: surface effect (SS) due to increased surface-volume ratio and quantum size effect (QSE) due to quantum confinement in reduced dimension. The SS has been widely shown to affect the elastic constants and mechanical properties of nanostructures. Here, using Pb nanofilm and graphene nanoribbon as model systems, we demonstrate the QSE on the elastic constants of nanostructures by first-principles calculations. We show that generally QSE is dominant in affecting the elastic constants of metallic nanostructures while SS is more pronounced in semiconductor and insulator nanostructures. Our findings have broad implications in quantum aspects of nanomechanics

    COMCAT: Towards Efficient Compression and Customization of Attention-Based Vision Models

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    Attention-based vision models, such as Vision Transformer (ViT) and its variants, have shown promising performance in various computer vision tasks. However, these emerging architectures suffer from large model sizes and high computational costs, calling for efficient model compression solutions. To date, pruning ViTs has been well studied, while other compression strategies that have been widely applied in CNN compression, e.g., model factorization, is little explored in the context of ViT compression. This paper explores an efficient method for compressing vision transformers to enrich the toolset for obtaining compact attention-based vision models. Based on the new insight on the multi-head attention layer, we develop a highly efficient ViT compression solution, which outperforms the state-of-the-art pruning methods. For compressing DeiT-small and DeiT-base models on ImageNet, our proposed approach can achieve 0.45% and 0.76% higher top-1 accuracy even with fewer parameters. Our finding can also be applied to improve the customization efficiency of text-to-image diffusion models, with much faster training (up to 2.6×2.6\times speedup) and lower extra storage cost (up to 1927.5×1927.5\times reduction) than the existing works.Comment: ICML 2023 Poste

    Dynamic similarity design method for an aero-engine dualrotor test rig

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    This paper presents a dynamic similarity design method to design a scale dynamic similarity model (DSM) for a dual-rotor test rig of an aero-engine. Such a test rig is usually used to investigate the major dynamic characteristics of the full-size model (FSM) and to reduce the testing cost and time for experiments on practical aero engine structures. Firstly, the dynamic equivalent model (DEM) of a dual-rotor system is modelled based on its FSM using parametric modelling, and the first 10 frequencies and mode shapes of the DEM are updated to agree with the FSM by modifying the geometrical shapes of the DEM. Then, the scaling laws for the relative parameters (such as geometry sizes of the rotors, stiffness of the supports, inherent properties) between the DEM and its scale DSM were derived from their equations of motion, and the scaling factors of the above-mentioned parameters are determined by the theory of dimensional analyses. After that, the corresponding parameters of the scale DSM of the dual-rotor test rig can be determined by using the scaling factors. In addition, the scale DSM is further updated by considering the coupling effect between the disks and shafts. Finally, critical speed and unbalance response analysis of the FSM and the updated scale DSM are performed to validate the proposed method

    Spatial differentiation and influencing factors of active layer thickness in the Da Hinggan Ling Prefecture

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    Active layer thickness (ALT) of permafrost changes significantly under the combined influence of human activities and climate warming, which has a significant impact on the ecological environment, hydrology, and engineering construction in cold regions. The spatial differentiation of Active layer thickness and its influencing factors have become one of the hot topics in the field of cryopedology in recent years, but there are few studies in the Da Hinggan Ling Prefecture (DHLP). In this study, the Stefan equation was used to simulate the Active layer thickness in the Da Hinggan Ling Prefecture, and the factor detection and interaction detection functions of geodetector were used to analyze the factors affecting the spatial differentiation of Active layer thickness from both natural and humanity aspects. The results showed that Active layer thickness in the Da Hinggan Ling Prefecture ranges from 58.82 cm to 212.55 cm, the determinant coefficient R2, MAE, RMSE between simulation results and the sampling points data were 0.86, 11.25 (cm) and 13.25 (cm), respectively. Lower Active layer thickness values are mainly distributed higher elevations in the west, which are dominated by forest (average ALT: 136.94 cm) and wetlands (average ALT: 71.88 cm), while the higher values are distributed on cultivated land (average ALT: 170.35 cm) and construction land (average ALT: 176.49 cm) in the southeast. Among the influencing factors, elevation is significantly negatively correlated with ALT. followed by summer mean LST, SLHF and snow depth. NDVI and SM has the strong explanation power for the spatial differentiation of ALT in factor detection. Regarding interactions, the explanatory power of slope ∩ snow depth is the highest of 0.83, followed by the elevation ∩ distance to settlements. The results can provide reference for the formulation of ecological environmental protection and engineering construction policies in cold regions

    455 Pegasus Lung, a platform study of SAR444245 (THOR-707, a pegylated recombinant non-alpha IL-2) with anti-cancer agents in patients with non-small cell lung cancer (NSCLC) and mesothelioma

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    BackgroundSAR444245 (THOR-707) is a recombinant human IL-2 molecule that includes a PEG moiety irreversibly bound to a novel amino acid via click chemistry to block the alpha-binding domain while retaining near-native affinity for the beta/gamma subunits. In animal models, SAR444245 showed anti-tumor benefits, but with no severe side effects, both as single agent and when combined with anti-PD1 comparing with historical data from aldesleukin. The HAMMER trial, which is the FIH study shows preliminary encouraging clinical results: initial efficacy and safety profile with SAR444245 monotherapy and in combination with pembrolizumab support a non-alpha preferential activity, validating preclinical models. The Pegasus Lung Ph2 study will evaluate the clinical benefit of SAR444245 in combination with other anticancer therapies for the treatment of patients with lung cancer or pleural mesotheliomaMethodsThe Pegasus Lung (NCT04914897) will enroll approximately 354 patients in 6 separate cohorts concurrently or sequentially. In cohorts A1 & A2, patients with first line (L) NSCLC will receive SAR444245 + pembrolizumab. In cohort A3, patients with 1L non-squamous NSCLC will receive SAR444245 + pembrolizumab + pemetrexed + carboplatin/cisplatin. In cohort B1 & B2 patients with 2/3L NSCLC who have progressed on a checkpoint inhibitor (CPI)-based therapy will receive SAR444245 + pembrolizumab, or SAR444245 + pembrolizumab + nab-paclitaxel. In cohort C patients with 2/3L CPI naïve mesothelioma will receive SAR444245 + pembrolizumab. SAR444245 is administered IV at a dose of 24 ug/kg Q3W in an outpatient setting until disease progression or completion of 35 cycles. Pembrolizumab is administered at a dose of 200 mg Q3W until PD or completion of 35 cycles. The study primary objective is to determine the antitumor activity of SAR444245 in combination with other anticancer therapies. Secondary objectives include confirmation of dose and safety profile, assess other indicators of antitumor activity, and assess the pharmacokinetic profile and immunogenicity of SAR444245. The study will be conducted in the US, Australia, France, Italy, Japan, Poland, South Korea, Spain, and Taiwan.AcknowledgementsThe Pegasus Lung study is sponsored by Sanofi.Trial RegistrationNCT04914897Ethics ApprovalThis study has been approved by applicable ethics committees or institutional review boards. All participants gave informed consent before taking part.ConsentWritten informed consent was obtained from the patient for publication of this abstract and any accompanying images. A copy of the written consent is available for review by the Editor of this journal

    N 2,N 2′-Bis(2-hydroxy­benzyl­idene)-2,2′-bipyridyl-3,3′-dicarbohydrazide

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    In the title compound, C26H20N6O4, the two aroylhydrazone side groups exist as diastereomeres, both in the keto form in the crystal structure. The aroylhydrazone units support the mol­ecular conformation through an intra­molecular N—H⋯O hydrogen bond. Two mol­ecules are connected into a centrosymmetric dimer by inter­molecular N—H⋯N hydrogen bonds. These dimers are connected into chains along the a axis by inter­molecular O—H⋯O hydrogen bonds. The combination of these hydrogen bonds results in layers in the bc plane. The layers are further linked by weak C—H⋯π contacts to form a three-dimensional network structure

    435 Pegasus HNSCC, a platform study of SAR444245 (THOR-707, a pegylated recombinant non-alpha IL-2) with anti-cancer agents in patients with recurrent/metastatic head and neck squamous cell carcinoma

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    BackgroundSAR444245 (THOR-707) is a recombinant human IL-2 molecule that includes a PEG moiety irreversibly bound to a novel amino acid via click chemistry to block the alpha-binding domain while retaining near-native affinity for the beta/gamma subunits. In animal models, SAR444245 showed anti-tumor benefits, but with no severe side effects, both as single agent and when combined with anti-PD1 comparing with historical data from aldeslukin. Preclinical study demonstrated SAR444245 enhances ADCC function of cetuximab. The HAMMER trial, which is the FIH study shows preliminary encouraging clinical results: initial efficacy and safety profile with SAR444245 monotherapy and in combination with pembrolizumab or with cetuximab support a non-alpha preferential activity, validating preclinical models. The Pegasus Head and Neck Ph 2 study will evaluate the clinical benefit of SAR444245 in combination with other anticancer therapies for the treatment of patients with R/M HNSCC.MethodsThe Pegasus Head and Neck will enroll approximately 272 patients in 4 separate cohorts concurrently. In cohorts A1 & A2, 1L R/M HNSCC patients will receive SAR444245 + pembrolizumab, or SAR444245+ pembrolizumab+ cetuximab respectively. In cohort B1 & B2 patients with 2/3L R/M HNSCC failed a checkpoint based regimen & a platinum containing regimen will receive SAR444245 + pembrolizumab, or SAR444245 + cetuximab. Patients to be enrolled in cohort B2 need to be cetuximab-naïve in R/M setting. SAR444245 is administered intravenously IV at a dose of 24 ug/kg Q3W until disease progression (PD) or completion of 35 cycles. Pembrolizumab is administered at a dose of 200 mg Q3W until PD or completion of 35 cycles. Cetuximab is administered at a dose of 400/250 mg/m2 QW until PD. The study primary objective is to determine the antitumor activity of SAR444245 in combination with other anticancer therapies. Secondary objectives include confirmation of dose and safety profile, assess other indicators of antitumor activity, and assess the pharmacokinetic profile and immunogenicity of SAR444245. The study will be conducted in the US, Canada, France, Germany, Italy, Netherlands, Poland, South Korea, Spain and Taiwan.AcknowledgementsThe Pegasus Head and Neck study is sponsored by Sanofi

    Short Communication Reflectance-based detection of oxidizers in ambient air

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    This study used two types of paper supported materials with a prototype, reflectance-based detector for indication of hydrogen peroxide vapor under ambient laboratory conditions. Titanyl based indicators provide detection through reaction of the indicator resulting in a dosimeter type sensor, while porphyrin based indicators provide a reversible interaction more suitable to continuous monitoring applications. These indicators provide the basis for discussion of characteristics important to design of a sensor system including the application environment and duration, desired reporting frequency, and target specificity

    Short Communication Reflectance-based detection of oxidizers in ambient air

    Get PDF
    This study used two types of paper supported materials with a prototype, reflectance-based detector for indication of hydrogen peroxide vapor under ambient laboratory conditions. Titanyl based indicators provide detection through reaction of the indicator resulting in a dosimeter type sensor, while porphyrin based indicators provide a reversible interaction more suitable to continuous monitoring applications. These indicators provide the basis for discussion of characteristics important to design of a sensor system including the application environment and duration, desired reporting frequency, and target specificity
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