282 research outputs found
Thermodynamic Property Study on the Complexes of Rare- Earth Elements with Amino Aids
In this chapter, the following three rare-earth complexes with amino acids, Eu(Glu)(Im)5(ClO4)3⋅3HClO4⋅6H2O, Nd(Gly)2Cl3⋅3H2O, and La(Glu)(Im)6(ClO4)3⋅4HClO4⋅4H2O, are synthesized and characterized by element analysis, infrared (IR) spectrum, and x-ray diffraction (XRD) analysis. The thermodynamic property studies on these complexes are performed. For the first one, Eu(Glu)(Im)5(ClO4)3⋅3HClO4⋅6H2O, the low temperature heat capacity, phase transition, and thermodynamic functions are determined by adiabatic calorimetry. For the second one, Nd(Gly)2Cl3⋅3H2O, the molar dissolution enthalpy and standard molar enthalpy of formation are determined by isoperibol solution reaction calorimetry. For the third one, La(Glu)(Im)6(ClO4)3⋅4HClO4⋅4H2O, the microcalorimetry is used to investigate the interaction between the complex and the Escherichia coli DH5α to elucidate the biological effects of the complex
Conversational Speech Recognition by Learning Audio-textual Cross-modal Contextual Representation
Automatic Speech Recognition (ASR) in conversational settings presents unique
challenges, including extracting relevant contextual information from previous
conversational turns. Due to irrelevant content, error propagation, and
redundancy, existing methods struggle to extract longer and more effective
contexts. To address this issue, we introduce a novel Conversational ASR
system, extending the Conformer encoder-decoder model with cross-modal
conversational representation. Our approach leverages a cross-modal extractor
that combines pre-trained speech and text models through a specialized encoder
and a modal-level mask input. This enables the extraction of richer historical
speech context without explicit error propagation. We also incorporate
conditional latent variational modules to learn conversational level attributes
such as role preference and topic coherence. By introducing both cross-modal
and conversational representations into the decoder, our model retains context
over longer sentences without information loss, achieving relative accuracy
improvements of 8.8% and 23% on Mandarin conversation datasets HKUST and
MagicData-RAMC, respectively, compared to the standard Conformer model.Comment: Submitted to TASL
Incorporating Probing Signals into Multimodal Machine Translation via Visual Question-Answering Pairs
This paper presents an in-depth study of multimodal machine translation
(MMT), examining the prevailing understanding that MMT systems exhibit
decreased sensitivity to visual information when text inputs are complete.
Instead, we attribute this phenomenon to insufficient cross-modal interaction,
rather than image information redundancy. A novel approach is proposed to
generate parallel Visual Question-Answering (VQA) style pairs from the source
text, fostering more robust cross-modal interaction. Using Large Language
Models (LLMs), we explicitly model the probing signal in MMT to convert it into
VQA-style data to create the Multi30K-VQA dataset. An MMT-VQA multitask
learning framework is introduced to incorporate explicit probing signals from
the dataset into the MMT training process. Experimental results on two
widely-used benchmarks demonstrate the effectiveness of this novel approach.
Our code and data would be available at:
\url{https://github.com/libeineu/MMT-VQA}.Comment: Findings of EMNLP202
Investigation into the dynamic change pattern of the stress field during integral fracturing in deep reservoirs
Deep reservoirs have high temperature, high pressure, and high stress. The development of such resources is high cost. Integral fracturing applies one-time well displacement, batch drilling, and batch fracturing. Multiple wells are stimulated with zipper fracturing. It can avoid the interference of the well drilling and fracturing. In this way, the spatial stresses can be utilized to generate the complex fracture network. The dynamic change pattern of the stress field is of great value for the design of integral fracturing. Based on the displacement discontinuity method (DDM) and the fracture mechanics criteria, a whole fracture propagation program is developed to calculate the spatial stress distribution and the whole fracture geometry. The reliability of the program is verified against the classical analytical solutions. Based on the program, this work systematically investigates the effects of the fracture length, the fracturing sequence, the fracture distribution mode, and the injection pressure on the stress field. The main conclusions are as follows: 1) When the fracture half-length is 150 m and the well spacing is 300 m, the staggered fracture distribution mode can ensure uniform fracture propagation and realize the active utilization of inter-well stress field; 2) Compared with the relative fracture distribution mode, the staggered fracture distribution mode is less susceptible to the stress field induced by the adjacent hydraulic fractures, hydraulic fractures tend to propagate along the direction of the maximum horizontal principal stress; 3) The stress field is highly influenced by the in-fracture fluid pressure. The stress interference is stronger with a greater fluid injection pressure and a higher fracture deflection angle will be obtained. It can enhance the fracture propagation resistance and increase the stress value. This work discovers the stress change pattern and lays out a solid foundation for the optimization of the integral fracturing
Tris(1,10-phenanthroline-κ2 N,N′)zinc(II) chloride 2-phenyl-4-selenazole-5-carboxylate decahydrate
The asymmetric unit of the title salt, [Zn(C12H8N2)3](C10H6NO2Se)Cl·10H2O, contains a [Zn(phen)3]2+ cation (phen is 1,10-phenanthroline), uncoordinated chloride and 2-phenyl-4-selenazole-5-carboxylate anions and ten uncoordinated water molecules. The central ZnII ion is six-coordinated by six N atoms from three phen ligands in a distorted octahedral geometry. An extensive O—H⋯O, O—H⋯N and O—H⋯Cl hydrogen-bonding network stabilizes the crystal structure
1,25-hydroxyvitamin D relieves colitis in rats via downregulation of toll-like receptor 9 expression
Aim To investigate the therapeutic and immunoregulatory
effects of 1,25-dihydroxyvitamin D (1,25(OH)D3) on 2,4,6-
trinitrobenzenesulfonic acid (TNBS) -induced colitis in rats.
Methods Experimental colitis induced by enema administration
of TNBS plus ethanol was treated with 5-aminosalicylic
acid (5-ASA) and/or 1,25(OH)D3. Disease activity was
measured using the disease activation index (DAI), colon
macroscopic damage index (CMDI), histological colonic
damage score, and myeloperoxidase (MPO) activity. The
expression of toll-like receptor 9 (TLR9) in the colon was
determined by reverse transcription-polymerase chain reaction
and immunohistochemistry.
Results Rats with TNBS-induced colitis had significantly elevated
DAI, CMDI, histological colonic damage score, and
MPO activity (all P < 0.001) compared to rats without colitis.
Treatment with 5-ASA or 1,25(OH)D3 ameliorated colitis
by lowering CMDI (P = 0.049, P = 0.040, respectively), histological
colonic damage score (P = 0.010, P = 0.005, respectively),
and MPO activity (P = 0.0003, P = 0.0013, respectively)
compared with the TNBS group. Combined treatment
with 5-ASA and 1,25(OH)D3 significantly decreased MPO
activity (P = 0.003). 1,25(OH)D3 attenuated colitis without
causing hypercalcemia or renal insufficiency. TNBS significantly
increased the number of TLR9 positive cells compared
to control (P < 0.010), while 5-ASA, 1,25(OH)D3, and
combined treatment with 5-ASA and 1,25(OH)D3 significantly
decreased it compared to TNBS group (all P < 0.010).
In TNBS group a moderate correlation was observed between
MPO activity and the number of TLR9-positive cells
(r = 0.654, P < 0.001).
Conclusion TLR9 expression correlates with the extent of
inflammation in TNBS-induced colitis. 1,25(OH)D3 relieves
this inflammation possibly by decreasing TLR9 expression
Inhibition of autophagy enhances SMI-4a-induced growth inhibition and apoptosis of melanoma cells
Purpose: To investigate the exact role of the proviral integration site for Moloney murine leukemia virus-1 (PIM-1) on autophagy as well as the underlying molecular mechanisms in melanoma.Methods: mRNA expression levels in A375 and G361 human melanoma cell lines were measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Enzyme-linked immunosorbent (ELISA) and western blotting assays were applied to determine protein expression levels, while cell viability was evaluated using Cell Counting Kit 8 and colony formation assay. Flow cytometric analysis and caspase 3/7 activity assay were used to assess apoptosis.Results: The results show that pharmacological inhibition of PIM-1 with its potent inhibitor (SMI-4a) suppressed cell viability and induced apoptosis in melanoma cell lines A375 and G361. SMI-4a also induced autophagy through inhibition of the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) axis in melanoma cells. Furthermore, chloroquine, an inhibitor of autophagy, potentiated the SMI-4a-induced inhibition of tumour growth and promotion of apoptosis in melanoma cells in vitro and in vivo.Conclusions: These results suggest that SMI-4a induces protective autophagy via PI3K/AKT/mTOR signaling pathway in melanoma cells. Thus, a combination of SMI-4a and an inhibitor of autophagy might be a novel approach to melanoma therapy.Keywords: Apoptosis, Autophagy, Cell viability, Melanoma, PIM-1, SMI-4
2-Phenyl-1,3-selenazole-4-carboxylic acid
In the title compound, C10H7NO2Se, the two rings are twisted, making a dihedral angle of 12.42 (9)°. In the crystal, pairs of molecules are disposed about an inversion center, generating O—H⋯O hydrogen-bonded dimers
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