214 research outputs found
The Graph Convolutional Network with Multi-representation Alignment for Drug Synergy Prediction
Drug combination refers to the use of two or more drugs to treat a specific
disease at the same time. It is currently the mainstream way to treat complex
diseases. Compared with single drugs, drug combinations have better efficacy
and can better inhibit toxicity and drug resistance. The computational model
based on deep learning concatenates the representation of multiple drugs and
the corresponding cell line feature as input, and the output is whether the
drug combination can have an inhibitory effect on the cell line. However, this
strategy of concatenating multiple representations has the following defects:
the alignment of drug representation and cell line representation is ignored,
resulting in the synergistic relationship not being reflected positionally in
the embedding space. Moreover, the alignment measurement function in deep
learning cannot be suitable for drug synergy prediction tasks due to
differences in input types. Therefore, in this work, we propose a graph
convolutional network with multi-representation alignment (GCNMRA) for
predicting drug synergy. In the GCNMRA model, we designed a
multi-representation alignment function suitable for the drug synergy
prediction task so that the positional relationship between drug
representations and cell line representation is reflected in the embedding
space. In addition, the vector modulus of drug representations and cell line
representation is considered to improve the accuracy of calculation results and
accelerate model convergence. Finally, many relevant experiments were run on
multiple drug synergy datasets to verify the effectiveness of the above
innovative elements and the excellence of the GCNMRA model.Comment: 14 pages
GraphCL-DTA: a graph contrastive learning with molecular semantics for drug-target binding affinity prediction
Drug-target binding affinity prediction plays an important role in the early
stages of drug discovery, which can infer the strength of interactions between
new drugs and new targets. However, the performance of previous computational
models is limited by the following drawbacks. The learning of drug
representation relies only on supervised data, without taking into account the
information contained in the molecular graph itself. Moreover, most previous
studies tended to design complicated representation learning module, while
uniformity, which is used to measure representation quality, is ignored. In
this study, we propose GraphCL-DTA, a graph contrastive learning with molecular
semantics for drug-target binding affinity prediction. In GraphCL-DTA, we
design a graph contrastive learning framework for molecular graphs to learn
drug representations, so that the semantics of molecular graphs are preserved.
Through this graph contrastive framework, a more essential and effective drug
representation can be learned without additional supervised data. Next, we
design a new loss function that can be directly used to smoothly adjust the
uniformity of drug and target representations. By directly optimizing the
uniformity of representations, the representation quality of drugs and targets
can be improved. The effectiveness of the above innovative elements is verified
on two real datasets, KIBA and Davis. The excellent performance of GraphCL-DTA
on the above datasets suggests its superiority to the state-of-the-art model.Comment: 13 pages, 4 figures, 5 table
Chromospherically Active Stars. VI. HD 136901 = UV CrB: A Massive Ellipsoidal K Giant Single-Lined Spectroscopic Binary
The variable star HD 136901 = UV CrB is a chromospherically active K2 III single-lined spectroscopic binary with an orbital period of 18.665 days. It has modest-strength Ca H and K emission and UV features, while H-alpha is a strong absorption feature containing little or no emission. The inclination of the system is 53 + or - 12 deg. The v sin i of the primary is 42 + or - 2 km/s, resulting in a minimum radius of 15.5 + or - 0.8 solar. When compared with the Roche lobe radius, this results in a mass ratio of 2.90 or larger. Additional constraints indicate that the secondary has a mass between 0.85 and 1.25 solar. Thus, the mass of the primary is at least 2.5 solar and probably is in the range 2.5-4 solar
Speckle and Spectroscopic Orbits of the Early A-Type Triple System in Virginis
Eta Virginis is a bright (V = 3.89) triple system of composite spectral type A2 IV that has been observed for over a dozen years with both spectroscopy and speckle interferometry. Analysis of the speckle observations results in a long period of 13.1 yr. This period is also detected in residuals from the spectroscopic observations of the 71.7919 day short-period orbit. Elements of the long-period orbit were determined separately using the observations of both techniques. The more accurate elements from the speckle solution have been assumed in a simultaneous spectroscopic determination of the short- and long-period orbital elements. The magnitude difference of the speckle components suggests that lines of the third star should be visible in the spectrum
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