Imaging constituent quark shape of proton with exclusive vector meson production at HERA

We show within proton hot spot picture that the exclusive vector meson production in electron-proton deeply inelastic scattering is sensitive to the individual width of the constituent quarks of the proton. For comparison, we calculate the exclusive $J/\Psi$ production cross-sections in three cases, $\mathrm{B_u} \geq \mathrm{B_d}$, $\mathrm{B_u} < \mathrm{B_d}$ and $\mathrm{B_u}\neq\mathrm{B^{\prime}_u}\neq\mathrm{B_d}$, where the $\mathrm{B_u}$, $\mathrm{B^{\prime}_u}$ and $\mathrm{B_d}$ denote the widths of two up quarks and down quark. We find that only results calculated with $\mathrm{B_u} \geq \mathrm{B_d}$ can give a reasonable description of the exclusive $J/\Psi$ production cross-section data at HERA. To test that our results are independent of the details of the model, we retain the average width of the three constituent quarks unchanged and compute the exclusive $J/\Psi$ production cross-sections with contribution weight by setting different proportional coefficients ($\mathrm{W_u}$ and $\mathrm{W_d}$) for the up and down quarks, respectively. It shows that the results calculated with $\mathrm{W_u}\geq\mathrm{W_d}$ can well reproduce the exclusive $J/\Psi$ production data at HERA, while the opposite case cannot describe the HERA data. These interesting findings seem to indicate that the up quark has more gluons around it than the down quark at high energy although the spatial distribution of gluons fluctuates event-by-event . To ensure the relevant results independent of the species of the vector meson, we also calculate the $\rho$ production cross-sections with the same group of parameters used in the exclusive $J/\Psi$ production and compare the predictions with the HERA data. It shows that all the results computed in the exclusive $\rho$ productions are consistent with the findings obtained in the exclusive $J/\Psi$ productions.Comment: 12 pages, 6 figure

Persona-centric Metamorphic Relation guided Robustness Evaluation for Multi-turn Dialogue Modelling

Recently there has been significant progress in the field of dialogue system thanks to the introduction of training paradigms such as fine-tune and prompt learning. Persona can function as the prior knowledge for maintaining the personality consistency of dialogue systems, which makes it perform well on accuracy. Nonetheless, the conventional reference-based evaluation method falls short in capturing the genuine text comprehension prowess of the model, significantly relying on the quality of data annotation. In contrast, the application of metamorphic testing offers a more profound insight into the model's distinct capabilities without necessitating supplementary annotation labels. This approach furnishes a more comprehensive portrayal of the model's intricacies and exposes intricacies concealed within reference-based validation techniques. Consequently, we introduce a persona-centric metamorphic relation construction for metamorphic testing, aimed at evaluating both the persona consistency and robustness of personalized dialogue models. For that reason, this work evaluates several widely used training paradigms including learning from scratch, pretrain + fine-tune and prompt learning in personalized dialogue retrieval to know if they are more robust or if they have the same flaws as their predecessor. Under three kinds of designed metamorphic relations with consistent outputs, our experimental results reveal that prompt learning shows stronger robustness compared to training from scratch and fine-tune. Although tested retrieval models gain competitively high retrieval accuracy according to the traditional reference-based validation, they are still fragile and demonstrate various unexpected behaviors, thus there is still room for future improvement in personalized dialogue retrieval

Virus-derived transgenes expressing hairpin RNA give immunity to Tobacco mosaic virus and Cucumber mosaic virus

<p>Abstract</p> <p>Background</p> <p>An effective method for obtaining resistant transgenic plants is to induce RNA silencing by expressing virus-derived dsRNA in plants and this method has been successfully implemented for the generation of different plant lines resistant to many plant viruses.</p> <p>Results</p> <p>Inverted repeats of the partial <it>Tobacco mosaic virus </it>(TMV) movement protein (MP) gene and the partial <it>Cucumber mosaic virus </it>(CMV) replication protein (Rep) gene were introduced into the plant expression vector and the recombinant plasmids were transformed into <it>Agrobacterium tumefaciens</it>. <it>Agrobacterium</it>-mediated transformation was carried out and three transgenic tobacco lines (MP16-17-3, MP16-17-29 and MP16-17-58) immune to TMV infection and three transgenic tobacco lines (Rep15-1-1, Rep15-1-7 and Rep15-1-32) immune to CMV infection were obtained. Virus inoculation assays showed that the resistance of these transgenic plants could inherit and keep stable in T₄progeny. The low temperature (15℃) did not influence the resistance of transgenic plants. There was no significant correlation between the resistance and the copy number of the transgene. CMV infection could not break the resistance to TMV in the transgenic tobacco plants expressing TMV hairpin MP RNA.</p> <p>Conclusions</p> <p>We have demonstrated that transgenic tobacco plants expressed partial TMV movement gene and partial CMV replicase gene in the form of an intermolecular intron-hairpin RNA exhibited complete resistance to TMV or CMV infection.</p

The relationship between gastric microbiome features and responses to neoadjuvant chemotherapy in gastric cancer

BackgroundEmerging evidence demonstrates that the gastrointestinal microbiome has the potential to be a biomarker in neoadjuvant chemoradiotherapy for colorectal cancer (CRC). Yet studies on the impact of the gastric microbiome (GM) on the response to neoadjuvant chemotherapy (NACT) are still scarce.MethodsForty-eight patients with gastric cancer participated in this retrospective study, and 16S rRNA sequencing was performed to evaluate formalin-fixed and paraffin-embedded (FFPE) tissue biospecimens and fresh-frozen tissues.ResultsIn this study, 16 bacterial taxa at different levels, including Bacillus, Anaerococcus, and Chloroflexi, were identified to be enriched before NACT in response (R) patients in group FFPE. In contrast, 6 bacterial taxa, such as Haemophilus, Veillonellaceae (Veillonella), etc. were enriched after NACT, in which we reported for the first time that the phylum Chloroflexi was enriched before NACT in R patients. Thirty-one bacterial taxa of Coriobacteriaceae, Ruminococcaceae, Veillonellaceae, and Lachnospiraceae were identified in group mucosa as being enriched in R patients. In comparison, 4 bacterial taxa dominated by the phylum Proteobacteria were enriched in NR patients. Notably, the family Veillonellaceae was found in both tissue samples, and the metabolic pathways, including the citrate cycle (TCA cycle) and various amino acids, including alanine, were found to be potentially predictive in both sample species.ConclusionThere are differences in the features of the GM for different NACT response results. The causal relationship deserves to be confirmed by further investigations

Preparation and ageing-resistant properties of polyester composites modified with functional nanoscale additives

This study investigated ageing-resistant properties of carboxyl-terminated polyester (polyethylene glycol terephthalate) composites modified with nanoscale titanium dioxide particles (nano-TiO(2)). The nano-TiO(2) was pretreated by a dry coating method, with aluminate coupling agent as a functional grafting additive. The agglomeration resistance was evaluated, which exhibited significant improvement for the modified nanoparticles. Then, the effects of the modified nano-TiO(2) on the crosslinking and ageing-resistant properties of the composites were studied. With a real-time Fourier transform infrared (FT-IR) measurement, the nano-TiO(2) displayed promoting effect on the crosslinking of polyester resin with triglycidyl isocyanurate (TGIC) as crosslinking agent. Moreover, the gloss retention, colour aberration and the surface morphologies of the composites during accelerated UV ageing (1500 hours) were investigated. The results demonstrated much less degree of ageing degradation for the nanocomposites, indicating an important role of the nano-TiO(2) in improving the ageing-resistant properties of synthetic polymer composites

Spin-density-wave transition in double-layer nickelate La3Ni2O7

Recently, a signature of high-temperature superconductivity above the liquid nitrogen temperature (77 K) was reported for La3Ni2O7 under pressure. This finding immediately stimulates intense interest in the possible high-Tc superconducting mechanism in double-layer nickelates. Interestingly, the pressure-dependent phase diagram inferred from transport measurements indicates that superconductivity under high pressure emerges from the suppression of a density-wave-like transition at ambient pressure, which is similar to high-temperature superconductors. Therefore, clarifying the exact nature of the density-wave-like transition is important for determining the mechanism of superconductivity in double-layer nickelates. Here, nuclear magnetic resonance (NMR) spectroscopy of 139La nuclei was performed to study the density-wave-like transition in a single crystal of La3Ni2O7. The temperature-dependent 139La NMR spectrum and nuclear spin-lattice relaxation rate (1/T1) provide unambiguous evidence for a spin-density-wave (SDW) transition with a transition temperature TSDW of ~ 150 K. Furthermore, the anisotropic splitting of the NMR spectrum suggests a possible double spin stripe with magnetic moments along the c axis. In addition, the present NMR measurements also revealed spatial inhomogeneity of magnetism due to inner apical oxygen vacancies. All these results will be helpful for building a connection between superconductivity and magnetic interactions in double-layer nickelates.Comment: 14 pages, 4 figure