An Unexpected Deamination Reaction after Hydrolysis of the Pyrimidine (6-4) Pyrimidone Photoproduct

Pyrimidine (6-4) pyrimidone photoproduct (6-4PP), a common DNA photolesion formed under solar irradiation, was indicated to hydrolyze under strong basic conditions, breaking the N3–C4 bond at the 5′-thymine. The reanalysis of this reaction revealed that the resulting water adduct may not be stable as previously proposed; it readily undergoes an esterification reaction induced by the 5-OH group at 6-4PP to form a five-membered ring, eliminating a molecule of ammonia

The role of rifting in the development of the continental margins of the southwest subbasin, South China Sea : insights from an OBS experiment

Author Posting. © The Author(s), 2016. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Marine Geophysical Research 38 (2017): 105-123, doi:10.1007/s11001-016-9295-y.The continental margins of the southwest subbasin in the South China Sea mark a unique transition from multi-stages magma-poor continental rifting to seafloor spreading. We used reflection and refraction profiles across the margins to investigate the rifting process of the crust. Combining with the other seismic profiles acquired earlier, we focused on the comparative geological interpretation from the result of multichannel seismic analysis and wide-angle seismic tomography. Our result provides the evidence of upper crustal layer with abundant fractures below the acoustic basement with a P-wave velocity from 4.0 to 5.5 km s−1. It indicates extensive deformation of the brittle crust during the continental rifting and can make a good explanation for the observed extension discrepancy in the rift margins of the South China Sea. The seismic chronostratigraphic result shows the possibility of the intra-continental extension center stayed focused for quite a long time in Eocene. Additionally, our evidence suggested that continental margin of the southwest subbasin had experienced at least three rifting stages and the existence of the rigid blocks is an appropriate explanation to the asymmetric rifting of the South China Sea.This study was supported by the National Natural Science Foundation of China (grant 41404050, 41476033, 41576068, 41276049, U1505232, 91428204) and the National Program on Global Change and Air-Sea Interaction (grant GASI-GEOGE-01). The author was also supported by a fellowship of China Scholarship Council and Dr. Jian Lin while studying as a visiting graduate at the Woods Hole Oceanographic Institution, USA

Regression-free Blind Image Quality Assessment

Regression-based blind image quality assessment (IQA) models are susceptible to biased training samples, leading to a biased estimation of model parameters. To mitigate this issue, we propose a regression-free framework for image quality evaluation, which is founded upon retrieving similar instances by incorporating semantic and distortion features. The motivation behind this approach is rooted in the observation that the human visual system (HVS) has analogous visual responses to semantically similar image contents degraded by the same distortion. The proposed framework comprises two classification-based modules: semantic-based classification (SC) module and distortion-based classification (DC) module. Given a test image and an IQA database, the SC module retrieves multiple pristine images based on semantic similarity. The DC module then retrieves instances based on distortion similarity from the distorted images that correspond to each retrieved pristine image. Finally, the predicted quality score is derived by aggregating the subjective quality scores of multiple retrieved instances. Experimental results on four benchmark databases validate that the proposed model can remarkably outperform the state-of-the-art regression-based models.Comment: 11 pages, 7 figures, 50 conference

Exploring SMEFT Induced Non-Standard Interactions from COHERENT to Neutrino Oscillations

We investigate the prospects of next-generation neutrino oscillation experiments DUNE, T2HK and JUNO including TAO within Standard Model Effective Field Theory (SMEFT). We also re-interpret COHERENT data in this framework. Considering both charged and neutral current neutrino Non-Standard Interactions (NSIs), we analyse dimension-6 SMEFT operators and derive lower bounds to UV scale $\Lambda$. The most powerful probe is obtained on ${\cal O}_{{ledq}_{1211}}$ with $\Lambda \gtrsim$ 450 TeV due to the electron neutrino sample in T2HK near detector. We find DUNE and JUNO to be complementary to T2HK in exploring different subsets of SMEFT operators at about 25 TeV. We conclude that near detectors play a significant role in each experiment. We also find COHERENT with CsI and LAr targets to be sensitive to new physics up to $\sim$900 GeV.Comment: 48 pages, 9+9 figures, 7+5 tables, updated to account for CKM elements extracted from data properl

Curcumin attenuates migration and invasion of osteosarcoma cells by regulating expression of miR-33b5p/SIRT6 axis

Purpose: To investigate the potential role of curcumin in osteosarcoma (OS) cell migration and invasion, and also to explore the underlying mechanism of action. Methods: OS cell lines, Saos-2 and U2OS, were treated with various concentrations of curcumin (0, 10, 20, 50 μM) for 48 h. Transwell assay was used to determine the migratory and invasive activities of human OS cells while miR-33b-5p expression levels were measured using quantitative real time polymerase chain reaction (qRT-PCR). Expressions of metastasis-related genes, such as matrix metalloproteinases (MMPs), were quantified by qRT-PCR or western blot. The interaction between miR33b-5p and Sirtuin 6 (SIRT6) was evaluated by luciferase assay. Results: Curcumin inhibited the migratory and invasive activities of huamn OS cells, and downregulated MMP2 and MMP9 (p < 0.05). Moreover, in curcumin-treated OS cells, miR-33b-5p expression was upregulated while SIRT6 expression was significantly downregulated (p < 0.05). Overexpression of miR-33b-5p downregulated SIRT6 mRNA and protein expression, whereas transfection with miR-33b-5p inhibitor upregulated SIRT6 expression in OS cells (p < 0.05). Furthermore, curcumin suppressed SIRT6 expression by upregulating miR-33b-5p expression in OS cells. Finally, overexpression of SIRT6 or miR-33b-5p inhibitor reversed the suppression of OS cell metastasis induced by curcumin (p < 0.05). Conclusion: Curcumin inhibits SIRT6 expression via upregulating miR-33b-5p expression, which leads to the inhibition of OS cell migration and invasion. Thus, curcumin is a potential therapeutic agent for the management of OS

Nonlinear Transport of Graphene in the Quantum Hall Regime

We have studied the breakdown of the integer quantum Hall (QH) effect with fully broken symmetry, in an ultra-high mobility graphene device sandwiched between two single crystal hexagonal boron nitride substrates. The evolution and stabilities of the QH states are studied quantitatively through the nonlinear transport with dc Hall voltage bias. The mechanism of the QH breakdown in graphene and the movement of the Fermi energy with the electrical Hall field are discussed. This is the first study in which the stabilities of fully symmetry broken QH states are probed all together. Our results raise the possibility that the v=6 states might be a better target for the quantum resistance standard.Comment: 15 pages,6 figure

SAROTUP: Scanner and Reporter of Target-Unrelated Peptides

As epitope mimics, mimotopes have been widely utilized in the study of epitope prediction and the development of new diagnostics, therapeutics, and vaccines. Screening the random peptide libraries constructed with phage display or any other surface display technologies provides an efficient and convenient approach to acquire mimotopes. However, target-unrelated peptides creep into mimotopes from time to time through binding to contaminants or other components of the screening system. In this study, we present SAROTUP, a free web tool for scanning, reporting and excluding possible target-unrelated peptides from real mimotopes. Preliminary tests show that SAROTUP is efficient and capable of improving the accuracy of mimotope-based epitope mapping. It is also helpful for the development of mimotope-based diagnostics, therapeutics, and vaccines