80 research outputs found

    On the high-energy behavior of massive QCD amplitudes

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    In this note, we propose a factorization formula for gauge-theory scattering amplitudes up to two loops in the high-energy boosted limit. Our formula extends existing results in the literature by incorporating the contributions from massive loops. We derive the new ingredients in our formula using the method of regions with analytic regulators for the rapidity divergences. We verify our results with various form factors and the scattering amplitudes for top-quark pair production. Our results can be used to obtain approximate expressions for complicated two-loop massive amplitudes from simpler massless ones, and can be used to resum the mass logarithms to all orders in the coupling constant.Comment: 19 pages, 2 figure

    Experimental and Stress-Strain Equation Investigation on Compressive Strength of Raw and Modified Soil in Loess Plateau

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    As a special kind of soil is widely distributed in Loess Plateau of northwest China, it is difficult to use for growing crops and has poor structural property. According to local arid climate, the best utilization of the soil is as earthen construction material and it has been used for thousands of years. To research and improve the mechanical properties, the study investigates the response of soil with cement, lime, sand, and straw as admixtures to compressive loading. The influence on compressive strength and ductility of additives in different proportions is compared and analysed. The experimental data is also used for the formulation of dimensionless and generalized models describing the raw soil and modified soil’s full stress-strain response. The models can be applied to soil and modified soil in Loess Plateau with variable strength and deformation characteristics and therefore may be exploited for earthen construction design and nonlinear structural analyses

    Explanation-Guided Backdoor Attacks on Model-Agnostic RF Fingerprinting

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    Despite the proven capabilities of deep neural networks (DNNs) for radio frequency (RF) fingerprinting, their security vulnerabilities have been largely overlooked. Unlike the extensively studied image domain, few works have explored the threat of backdoor attacks on RF signals. In this paper, we analyze the susceptibility of DNN-based RF fingerprinting to backdoor attacks, focusing on a more practical scenario where attackers lack access to control model gradients and training processes. We propose leveraging explainable machine learning techniques and autoencoders to guide the selection of positions and values, enabling the creation of effective backdoor triggers in a model-agnostic manner. To comprehensively evaluate our backdoor attack, we employ four diverse datasets with two protocols (Wi-Fi and LoRa) across various DNN architectures. Given that RF signals are often transformed into the frequency or time-frequency domains, this study also assesses attack efficacy in the time-frequency domain. Furthermore, we experiment with potential defenses, demonstrating the difficulty of fully safeguarding against our attacks

    Overexpression of Peptide-Encoding OsCEP6.1 Results in Pleiotropic Effects on Growth in Rice (O. sativa)

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    Plant peptide hormone plays an important role in regulating plant developmental programs via cell-to-cell communication in a non-cell autonomous manner. To characterize the biological relevance of C-TERMINALLY ENCODED PEPTIDE (CEP) genes in rice, we performed a genome-wide search against public databases using bioinformatics approach and identified six additional CEP members. Expression analysis revealed a spatial-temporal pattern of OsCEP6.1 gene in different tissues and at different developmental stages of panicle. Interestingly, the expression level of the OsCEP6.1 was also significantly up-regulated by exogenous cytokinin. Application of a chemically synthesized 15-amino-acid OsCEP6.1 peptide showed that OsCEP6.1 had a negative role in regulating root and seedling growth, which was further confirmed by transgenic lines. Furthermore, the constitutive expression of OsCEP6.1 was sufficient to lead to panicle architecture and grain size variations. Scanning electron microscopy analysis revealed that the phenotypic variation of OsCEP6.1 overexpression lines resulted from decreased cell size but not reduced cell number. Moreover, starch accumulation was not significantly affected. Taken together, these data collectively suggest that the OsCEP6.1 peptide might be involved in regulating the development of panicles and grains in rice

    Perioperative lidocaine and dexmedetomidine intravenous infusion reduce the serum levels of NETs and biomarkers of tumor metastasis in lung cancer patients: A prospective, single-center, double-blinded, randomized clinical trial

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    BackgroundNeutrophil extracellular traps (NETs) can enhance the metastasis of non-small cell lung cancer (NSCLC). As biomarkers of tumor metastasis, metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) together with NETs are essential to endothelial-to-mesenchymal transition (EMT). We hypothesized that intravenous infusion of lidocaine and dexmedetomidine could reduce the production of NETs and biomarkers of tumor metastasis after video-assisted thoracic surgery (VATS) in NSCLC patients.MethodThe trial included 132 NSCLC patients undergoing VATS. The patients were equally randomized to a placebo group (Group C), a lidocaine group (Group L, intravenous lidocaine 8 mg/kg/h for 15 minutes before anesthesia, 2 mg/kg/h during surgery, and 1 mg/kg/h until 24 hours after surgery), a dexmedetomidine group (Group D, intravenous dexmedetomidine 2 μg/kg/h for 15 minutes before anesthesia, 0.5 μg/kg/h during surgery, and 0.25 μg/kg/h until 24 hours after surgery), and a dexmedetomidine plus lidocaine group (Group LD, combination use of lidocaine and dexmedetomidine). The primary outcome was the production of myeloperoxidase (MPO) and citrullinated histone-3 (H3Cit), biomarkers of NETs, on postoperative day (POD) 1. MMP-3, MMP-9, and VEGF-α, as biomarkers of tumor metastasis, were also evaluated on POD 1.ResultsThe baseline patient characteristics and perioperative data did not differ between the study groups. MPO was significantly decreased in Groups L, D, and LD (-197.08 ± 34.01, -137.37 ± 32.41, and -189.45 ± 33.73 U/ml, P<0.001, respectively) compared with Group C (-106.51 ± 25.44 U/ml). H3Cit was also lessened in Groups L, D, and LD (-49.51 ± 9.11, -34.80 ± 10.37, and -51.82 ± 8.98 ng/ml, P<0.001, respectively) compared with Group C (-24.73 ± 7.65 ng/ml). Lidocaine and dexmedetomidine also reduced MMP-3 (-69.08 ± 13.22, -52.84 ± 13.78, -85.34 ± 12.59 vs. -40.55 ± 10.71 ng/ml in Group L, D, LD vs. Group C, P<0.001, respectively), MMP-9 (-8.46 ± 1.68, -6.07 ± 1.82, -9.67 ± 1.43 vs. -4.28 ± 1.29 ng/ml in Group L, D, LD vs. Group C, P<0.001, respectively), and VEGF-α (-95.55 ± 22.53, -71.65 ± 18.77, -104.89 ± 15.49 vs. -51.73 ± 16.27 pg/ml in Group L, D, LD vs. Group C, P<0.001, respectively) on POD 1.ConclusionIn NSCLC patients, continuous perioperative intravenous infusion of lidocaine and dexmedetomidine significantly reduced the production of NETs and tumor metastasis biomarkers on POD 1. Meanwhile, it also decreased inflammation, protected cellular immune function, reduced pain and opioid consumption, and improved the quality of postoperative recovery.Clinical trial registrationchictr.org.cn, identifier: 187049

    The performance of large-pitch AC-LGAD with different N+ dose

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    AC-Coupled LGAD (AC-LGAD) is a new 4D detector developed based on the Low Gain Avalanche Diode (LGAD) technology, which can accurately measure the time and spatial information of particles. Institute of High Energy Physics (IHEP) designed a large-size AC-LGAD with a pitch of 2000 {\mu}m and AC pad of 1000 {\mu}m, and explored the effect of N+ layer dose on the spatial resolution and time resolution. The spatial resolution varied from 32.7 {\mu}m to 15.1 {\mu}m depending on N+ dose. The time resolution does not change significantly at different N+ doses, which is about 15-17 ps. AC-LGAD with a low N+ dose has a large attenuation factor and better spatial resolution. Large signal attenuation factor and low noise level are beneficial to improve the spatial resolution of the AC-LGAD sensor

    Identification of wheat stem rust resistance genes in wheat cultivars from Hebei province, China

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    Wheat stem rust is caused by Puccinia graminis f. sp. tritici. This major disease has been effectively controlled via resistance genes since the 1970s. The appearance and spread of new races of P. graminis f. sp. tritici (eg., Ug99, TKTTF, and TTRTF) have renewed the interest in identifying the resistance gene and breeding cultivars resistant to wheat stem rust. In this study, gene postulation, pedigree analysis, and molecular detection were used to determine the presence of stem rust resistance genes in 65 commercial wheat cultivars from Hebei Province. In addition, two predominant races 21C3CTHTM and 34MRGQM were used to evaluate the resistance of these cultivars at the adult-plant stage in 2021–2022. The results revealed that 6 Sr genes (namely, Sr5, Sr17, Sr24, Sr31, Sr32, Sr38, and SrTmp), either singly or in combination, were identified in 46 wheat cultivars. Overall, 37 wheat cultivars contained Sr31. Sr5 and Sr17 were present in 3 and 3 cultivars, respectively. Gao 5218 strong gluten, Jie 13-Ji 7369, and Kenong 1006 contained Sr24, Sr32, and Sr38, respectively. No wheat cultivar contained Sr25 and Sr26. In total, 50 (76.9%) wheat cultivars were resistant to all tested races of P. graminis f. sp. tritici in field test in 2021–2022. This study is important for breeding wheat cultivars with resistance to stem rust

    Characterization of the response of IHEP-IME LGAD with shallow carbon to Gamma Irradiation

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    Low Gain Avalanche Detectors (LGAD), as part of High-Granularity Timing Detector (HGTD), is crucial to reducing pileup in the upgrading to HL-LHC. Many studies have been done on the bulk damages of the LGAD. However, there's no study about the surface radiation hardness of the LGAD sensors with carbon implanted. The IHEP-IME LGAD version 3 with the shallow carbon and different interpad separations were irradiated up to 2 MGy by gamma irradiation. The performance of the IHEP-IME LGAD version 3 before and after irradiation had been tested, such as the leakage current, break-down voltage, capacitance, Vgl_{gl}, and inter-pad resistance. The results showed that apart from minor fluctuations in some samples, no significant changes concerning inter-pad separation were observed before and after irradiation. Leakage current and break-down voltage increase after irradiation, which is considered due to surface passivation; the overall inter-pad resistance are larger than $10^9\ \Omegabeforeandafterirradiation;capacitanceisfoundtobelessthan4.5pFwithaslightdropinV before and after irradiation; capacitance is found to be less than 4.5 pF with a slight drop in V_{gl}$ after irradiation. All parameters meet the requirements of HGTD, and the results indicated that IHEP-IME LGAD v3 has excellent anti-irradiation performance

    Characterisation of Spatial and Timing Resolution of IHEP AC-LGAD Strip

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    AC-coupled LGAD(AC-LGAD) Strip is a new design of LGAD that allows high-precision detection of particle spatiotemporal information whereas reducing the density of readout electronics. For AC-LGAD Strips, there is limited research on the impact of different strip pitches on the spatiotemporal detection performance at the small amount of injected charge. The Institute of High Energy Physics has designed an AC-LGAD Strip prototype with pitches of 150 μm\mu m, 200 μm\mu m, and 250 μm\mu m. The spatial and timing resolutions of the prototype are studied through the laser Transient Current Technique (TCT) scan with different amounts of injected charge. The results show that both the spatial and timing resolution improves as the strip pitch decreases. Increases in both temporal and spatial resolutions as the amount of charge injected increases are observed. The spatial and timing resolution is better than 60 ps and 40 μm\mu m at 1 Minimum Ionizing Particle (MIP), and better than 10 ps and 5 μm\mu m at 40 MIPs. Increasing Signal-to-Noise Ratio (SNR) is the key to improving spatial and temporal resolution, whereas increasing the signal attenuation rate by reducing the gap between adjacent electrodes also helps to improve spatial resolution. The enhancements of spatial and timing resolutions by both SNR and signal attenuation rate decrease with increasing amount of MIP. This study can help design and optimize the AC-LGAD Strip detectors and readout electronics
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