Solving the Bars-Green equation for moving mesons in two-dimensional QCD

The two-dimensional QCD in the large $N$ limit, generally referred to as the 't Hooft model, is numerically investigated in the axial gauge in a comprehensive manner. The corresponding Bethe-Salpeter equation for a bound $q\bar{q}$ pair, originally derived by Bars and Green in 1978, was first numerically tackled by Li and collaborators in late 1980s, yet only for the {\it stationary} mesons. In this paper, we make further progress by numerically solving the Bars-Green equation for {\it moving} mesons, ranging from the chiral pion to charmonium. By choosing several different quark masses, we computed the corresponding quark condensates, meson spectra and their decay constants for a variety of meson momenta, and found satisfactory agreement with their counterparts obtained using light-cone gauge, thus numerically verified the gauge and Poincar\'{e} invariance of the 't Hooft model. Moreover, we have explicitly confirmed that, as the meson gets more and more boosted, the large component of the Bars-Green wave function indeed approaches the corresponding 't Hooft light-cone wave function, while the small component of the wave function rapidly fades away.Comment: v2, 25 pages, 12 figures, and 1 table; Some figures updated, references added, typo corrrected; to appear in JHE

Detecting GPC3-Expressing Hepatocellular Carcinoma with L5 Peptide-Guided Pretargeting Approach: An In Vitro MRI Experiment

Background and Aim: Glypican-3 (GPC3) is a novel molecular target for hepatocellular carcinoma (HCC). This study investigated the potential of an L5 peptide-guided pretargeting approach to identify GPC3-expressing HCC cells using ultra-small super-paramagnetic iron oxide (USPIO) as the MRI probe.Methods: Immunofluorescence with carboxyfluorescein (FAM)-labeled L5 peptide was performed in HepG2 and HL-7702 cells. Polyethylene glycol-modified ultrasmall superparamagnetic iron oxide (PEG-USPIO) and its conjugates with streptavidin (SA-PEG-USPIO) were synthesized, and hydrodynamic diameters, zeta potential, T2 relaxivity, and cytotoxicity were measured. MR T2-weighted imaging of HepG2 was performed to observe signal changes in the pretargeting group, which was first incubated with biotinylated L5 peptide and then with SA-PEG-USPIO. Prussian blue staining of cells was used to assess iron deposition.Results: Immunofluorescence assays showed high specificity of L5 peptide for GPC3. SA-PEG-USPIO nanoparticles had ≈36 nm hydrodynamic diameter, low toxicity, negative charge and high T2 relaxivity. MR imaging revealed that a significant negative enhancement was only observed in HepG2 cells from the pretargeting group, which also showed significant iron deposition with Prussian blue staining.Conclusion: MR imaging with USPIO as the probe has potential to identify GPC3-expressing HCC through L5 peptide-guided pretargeting approach

Dual functions of the ZmCCT-associated quantitative trait locus in flowering and stress responses under long-day conditions

Gene ontology enrichment of differentially expressed genes in HZ4 and HZ4-NIL in three development stages. (XLS 21 kb

Vector Meson Exchange and Radiative Nonleptonic Kaon Decays In ChPT

ChPT is a powerful tool to study low energy pseudoscalar mesons physics. After a short introduction to ChPT in chapter 1 and its application to radiative nonleptonic Kaon decays in chapter 2, we studied the contribution of vector meson exchang to the specific decay $K_S\rightarrow \pi^0 \pi^0 \gamma \gamma$. We fixed two coupling coefficients of $\mathcal{O}(p^6)$ weak effective chiral Lagrangian by using Bose symmetry, gauge symmetry and two bound equations got from experiment NA48. We show that vector meson exchange in weak sector is dominant at $\mathcal{O}(p^6)$, and its contribution cancels the biggest contribution at $\mathcal{O}(p^4)$ about 60%

Phosphoproteomic analysis of the response of maize leaves to drought, heat and their combination stress

Drought and heat stress, especially their combination, greatly affect crop production. Many studies have described transcriptome, proteome and phosphoproteome changes in response of plants to drought or heat stress. However, the study about the phosphoproteomic changes in response of crops to the combination stress is scare. To understand the mechanism of maize responses to the drought and heat combination stress, phosphoproteomic analysis was performed on maize leaves by using multiplex iTRAQ-based quantitative proteomic and LC-MS/MS methods. Five-leaf-stage maize was subjected to drought, heat or their combination, and the leaves were collected. Globally, heat, drought and the combined stress significantly changed the phosphorylation levels of 172, 149 and 144 phosphopeptides, respectively. These phosphopeptides corresponded to 282 proteins. Among them, 23 only responded to the combined stress and could not be predicted from their responses to single stressors; 30 and 75 only responded to drought and heat, respectively. Notably, 19 proteins were phosphorylated on different sites in response to the single and combination stresses. Of the seven significantly enriched phosphorylation motifs identified, two were common for all stresses, two were common for heat and the combined stress, and one was specific to the combined stress. The signaling pathways in which the phosphoproteins were involved clearly differed among the three stresses. Functional characterization of the phosphoproteins and the pathways identified here could lead to new targets for the enhancement of crop stress tolerance, which will be particularly important in the face of climate change and the increasing prevalence of abiotic stressors

Detecting GPC3-Expressing Hepatocellular Carcinoma with L5 Peptide-Guided Pretargeting Approach: In Vitro and In Vivo MR Imaging Experiments

Objective. To investigate the potential of L5 peptide-guided pretargeting approach to identify GPC3-expressing hepatocellular carcinoma (HCC) using ultrasmall superparamagnetic iron oxide (USPIO) as the MR probe. Methods. Immunofluorescence with carboxyfluorescein- (FAM-) labeled L5 peptide was performed in HepG2 cells. Polyethylene glycol-modified USPIO (PEG-USPIO) and its conjugation with streptavidin (SA-PEG-USPIO) were synthesized, and their hydrodynamic diameters, zeta potential, T2 relaxivity, and cytotoxicity were measured. In vitro and in vivo two-step pretargeting MR imaging was performed on HepG2 cells and tumor-bearing mice after the administration of biotinylated L5 peptide (first step), followed by SA-PEG-USPIO (second step). Prussian blue staining was performed to assess iron deposition in tumors. Results. The high specificity of L5 peptide for GPC3 was demonstrated. Generation of SA-PEG-USPIO nanoparticles with good biocompatibility (an average hydrodynamic diameter of 35.97 nm and a zeta potential of −7.91 mV), superparamagnetism (R2 = 0.1039 × 103 mM−1s−1), and low toxicity was achieved. The pretargeting group showed more enhancement than the nonpretargeting group both in vitro (60% vs 20%, P<0.05) and in vivo (32% vs 6%, P<0.001). Substantial iron deposition was only observed in HepG2 cells and tumors in the pretargeting group. Conclusion. L5 peptide-guided, two-step pretargeting approach with USPIO as the MR imaging probe is a lucrative strategy to specifically identify GPC3-expressing HCC

Large-Scale Discovery of Non-conventional Peptides in Maize and Arabidopsis Through an Integrated Peptidogenomic Pipeline

Non-conventional peptides (NCPs), which include small open reading frame-encoded peptides, play critical roles in fundamental biological processes. In this study, we developed an integrated peptidogenomic pipeline using high-throughput mass spectra to probe a customized six-frame translation database and applied it to large-scale identification of NCPs in plants.A total of 1993 and 1860 NCPs were unambiguously identified in maize and Arabidopsis, respectively. These NCPs showed distinct characteristics compared with conventional peptides and were derived from introns, 3' UTRs, 5' UTRs, junctions, and intergenic regions. Furthermore, our results showed that translation events in unannotated transcripts occur more broadly than previously thought. In addition, we found that dozens of maize NCPs are enriched within regions associated with phenotypic variations and domestication selection, indicating that they potentially are involved in genetic regulation of complex traits and domestication in maize. Taken together, our study developed an integrated peptidogenomic pipeline for large-scale identification of NCPs in plants, which would facilitate global characterization of NCPs from other plants. The identification of large-scale NCPs in both monocot (maize) and dicot (Arabidopsis) plants indicates that a large portion of plant genome can be translated into biologically functional molecules, which has important implications for functional genomic studies