3,696 research outputs found

    Radiative decays of the heavy-quark-spin molecular partner of Tcc+T_{cc}^+

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    With the assumptions that the Tcc+T_{cc}^+ discovered at LHCb is a DDD^{*}D hadronic molecule, using a nonrelativistic effective field theory we calculate the radiative partial widths of TccDDγT_{cc}^* \to D^*D\gamma with TccT_{cc}^* being a DDD^{*}D^{*} shallow bound state and the heavy-quark-spin partner of Tcc+T_{cc}^+. The I=0I=0 DDD^*D rescattering effect with the TccT_{cc} pole is taken into account. The results show that the isoscalar DDD^{\ast} D rescattering can increase the tree-level decay width of Tcc+D+D0γT_{cc}^{\ast +}\rightarrow D^{*+}D^0\gamma by about 50%50\%, while decrease that of Tcc+D0D+γT_{cc}^{\ast +}\rightarrow D^{*0}D^+\gamma by a similar amount. The two-body partial decay widths of the Tcc+T_{cc}^{*+} into Tcc+γT_{cc}^+\gamma and Tcc+π0T_{cc}^+\pi^0 are also calculated, and the results are about 6 keV6~\rm{keV} and 3 keV3~\rm{keV}, respectively. Considering that the DD^* needs to be reconstructed from the DπD\pi or DγD\gamma final state in an experimental measurement, the four-body partial widths of the Tcc+T_{cc}^{*+} into DDγγDD\gamma\gamma and DDπγDD\pi\gamma are explicitly calculated, and we find that the interference effect between different intermediate DDγD^*D\gamma states is small. The total radiative decay width of the TccT_{cc}^* is predicted to be about 24 keV24~\rm{keV}. Adding the hadronic decay widths of TccDDπT_{cc}^* \to D^*D\pi, the total width of the TccT_{cc}^* is finally predicted to be (65±2)(65\pm2) keV.Comment: 27 pages, 13 figures. arXiv admin note: text overlap with arXiv:2211.0247

    A Novel In Vitro

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    An alternative in vitro protocol for embryo induction directly from intact living seedlings of Phalaenopsis aphrodite subspecies formosana was established in this study. Without the supplementation of plant growth regulators (PGRs), no embryos were obtained from all the seedlings when cultured on the solid medium. In contrast, embryos formed from the seedlings on the 2-layer medium and the 2-step culture system without the use of PGRs. It was found that the age of the seedlings affected embryo induction. The 2-month-old seedlings typically had higher embryogenic responses when compared with the 4-month-old seedlings in the 2-layer medium or 2-step system. For the 2-month-old seedlings, 1 mg/L TDZ resulted in the highest number of embryos at the distal site of the shoot. However, on the leaves’ surface, 0.5 mg/L TDZ induced the highest number of embryos. When the 2-month-old seedlings were cultured using the 2-step method at 1 mg/L of TDZ, the highest embryogenic response was obtained, with an average of 44 embryos formed on each seedling. These adventitious embryos were able to convert into plantlets in a PGR-free 1/2 MS medium, and the plantlets had normal morphology and growth

    Conceptualized Representation Learning for Chinese Biomedical Text Mining

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    Biomedical text mining is becoming increasingly important as the number of biomedical documents and web data rapidly grows. Recently, word representation models such as BERT has gained popularity among researchers. However, it is difficult to estimate their performance on datasets containing biomedical texts as the word distributions of general and biomedical corpora are quite different. Moreover, the medical domain has long-tail concepts and terminologies that are difficult to be learned via language models. For the Chinese biomedical text, it is more difficult due to its complex structure and the variety of phrase combinations. In this paper, we investigate how the recently introduced pre-trained language model BERT can be adapted for Chinese biomedical corpora and propose a novel conceptualized representation learning approach. We also release a new Chinese Biomedical Language Understanding Evaluation benchmark (\textbf{ChineseBLUE}). We examine the effectiveness of Chinese pre-trained models: BERT, BERT-wwm, RoBERTa, and our approach. Experimental results on the benchmark show that our approach could bring significant gain. We release the pre-trained model on GitHub: https://github.com/alibaba-research/ChineseBLUE.Comment: WSDM2020 Health Da

    Simulation and application of loose tooling forging for heavy grinding roller shaft forgings

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    The grinding roller shaft is a key part of the grinding roller. It has a step-shaped shaft with different round cross-sections and 1850 mm × 1110 mm rectangular cross-section. If the general method of free forging is used, the upsetting diameter of ingot will reach 2900 mm, and 8400 t hydraulic press current will not be produced so that the loose tooling forging process is to be used. The loose tooling forging process of rectangular flange has been researched by using DEFORM-3D simulation software and establishing a reasonable forging process. The production results reveal that the heavy forgings used as grinding roller shafts can be successfully produced with the present 8400 t capacity hydraulic presses. The eligible forgings have proved the rationality of the technical process

    A Novel Plant Sesquiterpene Lactone Derivative, DETD-35, Suppresses BRAF V600E Mutant Melanoma Growth and Overcomes Acquired Vemurafenib Resistance in Mice

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    Acquired resistance to vemurafenib develops through reactivation of RAF/MEK/ERK signaling or bypass mechanisms. Recent combination therapies such as a MEK inhibitor combined with vemurafenib show improvement in major clinical end points but the percentage of patients with adverse toxic events is higher than with vemurafenib monotherapy and most patients ultimately relapse. Therefore, there is an urgent need to develop new anti-melanoma drugs and/or adjuvant agents for vemurafenib therapy. In this study, we created a novel semi-organically modified derivative, DETD-35, from deoxyelephantopin (DET), a plant sesquiterpene lactone demonstrated as an anti-inflammatory and anti-mammary tumor agent. Our results show that DETD-35 inhibited proliferation of a panel of melanoma cell lines, including acquired vemurafenib resistance A375 cells (A375-R) established in this study, with superior activities to DET and no cytotoxicity to normal melanocytes. DETD-35 suppressed tumor growth and reduced tumor mass as effectively as vemurafenib in A375 xenograft study. Furthermore, DETD-35 also reduced tumor growth in both acquired (A375-R) and intrinsic (A2058) vemurafenib resistance xenograft models, where vemurafenib showed no anti-tumor activity. Notably, the combination of DETD-35 and vemurafenib exhibited the most significant effects in both in vitro and in vivo xenograft studies due to synergism of the compound and the drug. Mechanistic studies suggested that DETD-35 overcame acquired vemurafenib resistance at least in part through deregulating MEK-ERK, Akt, and STAT3 signaling pathways and promoting apoptosis of cancer cells. Overall, our results suggest that DETD-35 may be useful as a therapeutic or adjuvant agent against BRAFV600E mutant and acquired vemurafenib resistance melanoma

    A Four-Stage Data Augmentation Approach to ResNet-Conformer Based Acoustic Modeling for Sound Event Localization and Detection

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    In this paper, we propose a novel four-stage data augmentation approach to ResNet-Conformer based acoustic modeling for sound event localization and detection (SELD). First, we explore two spatial augmentation techniques, namely audio channel swapping (ACS) and multi-channel simulation (MCS), to deal with data sparsity in SELD. ACS and MDS focus on augmenting the limited training data with expanding direction of arrival (DOA) representations such that the acoustic models trained with the augmented data are robust to localization variations of acoustic sources. Next, time-domain mixing (TDM) and time-frequency masking (TFM) are also investigated to deal with overlapping sound events and data diversity. Finally, ACS, MCS, TDM and TFM are combined in a step-by-step manner to form an effective four-stage data augmentation scheme. Tested on the Detection and Classification of Acoustic Scenes and Events (DCASE) 2020 data sets, our proposed augmentation approach greatly improves the system performance, ranking our submitted system in the first place in the SELD task of DCASE 2020 Challenge. Furthermore, we employ a ResNet-Conformer architecture to model both global and local context dependencies of an audio sequence to yield further gains over those architectures used in the DCASE 2020 SELD evaluations.Comment: 12 pages, 8 figure

    Distinct roles of NMB and GRP in itch transmission

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    A key question in our understanding of itch coding mechanisms is whether itch is relayed by dedicated molecular and neuronal pathways. Previous studies suggested that gastrin-releasing peptide (GRP) is an itch-specific neurotransmitter. Neuromedin B (NMB) is a mammalian member of the bombesin family of peptides closely related to GRP, but its role in itch is unclear. Here, we show that itch deficits in mice lacking NMB or GRP are non-redundant and Nmb/Grp double KO (DKO) mice displayed additive deficits. Furthermore, both Nmb/Grp and Nmbr/Grpr DKO mice responded normally to a wide array of noxious stimuli. Ablation of NMBR neurons partially attenuated peripherally induced itch without compromising nociceptive processing. Importantly, electrophysiological studies suggested that GRPR neurons receive glutamatergic input from NMBR neurons. Thus, we propose that NMB and GRP may transmit discrete itch information and NMBR neurons are an integral part of neural circuits for itch in the spinal cord

    Lini0.5mn1.5o4 spinel cathode using room temperature ionic liquid as electrolyte

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    In this study, LiNi0.5Mn1.5O4 (LNMO) nanoparticles were prepared as a 5 V cathode material via a rheological phase method and annealed at different temperatures: 680 ◦C, 750 ◦C, and 820 ◦C. The sample annealed at 750 ◦C shows the best performance. A room temperature ionic liquid (RTIL) containing 1 M lithium bis(trifluoromethanesulfonyl) imide (LiNTf2) in N-butyl-N-methyl-pyrrolidinium bis(trifluoromethanesulfonyl) imide (C4mpyrNTf2) was used as novel electrolyte in conjunction with the LNMO cathodes and their electrochemical properties have been investigated. The results show that the LNMO using RTIL as electrolyte has better coulombic efficiency and comparable discharge capacities to those of the cells assembled with standard liquid electrolyte (1 M LiPF6 in ethylene carbonate/diethyl carbonate). Electrochemical impedance spectroscopy shows that the RTIL is much more stable as the electrolyte for LiNi0.5Mn1.5O4 than the conventional electrolyte

    Ethyl 1-(6-chloro-3-pyridylmeth­yl)-5-methyl-1H-1,2,3-triazole-4-carboxyl­ate

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    In the title compound, C12H13ClN4O2, the triazole ring carries methyl and ethoxy­carbonyl groups, and is bound via a methyl­ene bridge to a chloro­pyridine unit. There is evidence for significant electron delocalization in the triazolyl system. Intra­molecular C—H⋯O and inter­molecular C—H⋯N hydrogen bonds stabilize the structure
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