学习表达性分子表示对于促进分子特性的准确预测至关重要。尽管图形神经网络（GNNS）在分子表示学习中取得了显着进步，但它们通常面临诸如邻居探索，不足，过度光滑和过度阵列之类的局限性。同样，由于参数数量大，GNN通常具有较高的计算复杂性。通常，当面对相对大尺寸的图形或使用更深的GNN模型体系结构时，这种限制会出现或增加。克服这些问题的一个想法是将分子图简化为小型，丰富且有益的信息，这更有效，更具挑战性的培训GNN。为此，我们提出了一个新颖的分子图粗化框架，名为FUNQG利用函数组，作为分子的有影响力的构件来确定其性质，基于称为商图的图理论概念。通过实验，我们表明所产生的信息图比分子图小得多，因此是训练GNN的良好候选者。我们将FUNQG应用于流行的分子属性预测基准，然后比较所获得的数据集上的GNN体系结构的性能与原始数据集上的几个最先进的基线。通过实验，除了其参数数量和低计算复杂性的急剧减少之外，该方法除了其急剧减少之外，在各种数据集上的表现显着优于先前的基准。因此，FUNQG可以用作解决分子表示学习问题的简单，成本效益且可靠的方法。

Although substantial efforts have been made using graph neural networks (GNNs) for AI-driven drug discovery (AIDD), effective molecular representation learning remains an open challenge, especially in the case of insufficient labeled molecules. Recent studies suggest that big GNN models pre-trained by self-supervised learning on unlabeled datasets enable better transfer performance in downstream molecular property prediction tasks. However, they often require large-scale datasets and considerable computational resources, which is time-consuming, computationally expensive, and environmentally unfriendly. To alleviate these limitations, we propose a novel pre-training model for molecular representation learning, Bi-branch Masked Graph Transformer Autoencoder (BatmanNet). BatmanNet features two tailored and complementary graph autoencoders to reconstruct the missing nodes and edges from a masked molecular graph. To our surprise, BatmanNet discovered that the highly masked proportion (60%) of the atoms and bonds achieved the best performance. We further propose an asymmetric graph-based encoder-decoder architecture for either nodes and edges, where a transformer-based encoder only takes the visible subset of nodes or edges, and a lightweight decoder reconstructs the original molecule from the latent representation and mask tokens. With this simple yet effective asymmetrical design, our BatmanNet can learn efficiently even from a much smaller-scale unlabeled molecular dataset to capture the underlying structural and semantic information, overcoming a major limitation of current deep neural networks for molecular representation learning. For instance, using only 250K unlabelled molecules as pre-training data, our BatmanNet with 2.575M parameters achieves a 0.5% improvement on the average AUC compared with the current state-of-the-art method with 100M parameters pre-trained on 11M molecules.

分子特性预测的深度学习模型的研究主要集中在更好的图形神经网络（GNN）架构的发展。虽然新的GNN变体继续提高性能，但它们的修改共享一个常见的主题，即减轻其基本图形到图形的内在内在的问题。在这项工作中，我们研究了这些限制，并提出了一种新的分子表现，可以完全绕过GNN的需求。与变压器模型配对时，我们的固定尺寸随机表示超出了最先进的GNN模型的性能，并提供了一种可扩展性的路径。

阐明并准确预测分子的吸毒性和生物活性在药物设计和发现中起关键作用，并且仍然是一个开放的挑战。最近，图神经网络（GNN）在基于图的分子属性预测方面取得了显着进步。但是，当前基于图的深度学习方法忽略了分子的分层信息以及特征通道之间的关系。在这项研究中，我们提出了一个精心设计的分层信息图神经网络框架（称为hignn），用于通过利用分子图和化学合成的可见的无限元素片段来预测分子特性。此外，首先在Hignn体系结构中设计了一个插件功能的注意块，以适应消息传递阶段后自适应重新校准原子特征。广泛的实验表明，Hignn在许多具有挑战性的药物发现相关基准数据集上实现了最先进的预测性能。此外，我们设计了一种分子碎片的相似性机制，以全面研究Hignn模型在子图水平上的解释性，表明Hignn作为强大的深度学习工具可以帮助化学家和药剂师识别出设计更好分子的关键分子，以设计更好的分子，以设计出所需的更好分子。属性或功能。源代码可在https://github.com/idruglab/hignn上公开获得。

Graph classification is an important area in both modern research and industry. Multiple applications, especially in chemistry and novel drug discovery, encourage rapid development of machine learning models in this area. To keep up with the pace of new research, proper experimental design, fair evaluation, and independent benchmarks are essential. Design of strong baselines is an indispensable element of such works. In this thesis, we explore multiple approaches to graph classification. We focus on Graph Neural Networks (GNNs), which emerged as a de facto standard deep learning technique for graph representation learning. Classical approaches, such as graph descriptors and molecular fingerprints, are also addressed. We design fair evaluation experimental protocol and choose proper datasets collection. This allows us to perform numerous experiments and rigorously analyze modern approaches. We arrive to many conclusions, which shed new light on performance and quality of novel algorithms. We investigate application of Jumping Knowledge GNN architecture to graph classification, which proves to be an efficient tool for improving base graph neural network architectures. Multiple improvements to baseline models are also proposed and experimentally verified, which constitutes an important contribution to the field of fair model comparison.

图形神经网络（GNN）正在化学工程中出现，以基于分子图的物理化学特性端到端学习。 GNNS的一个关键要素是合并函数，将原子矢量结合到分子指纹中。大多数以前的作品都使用标准池功能来预测各种属性。但是，不合适的合并功能会导致概括不佳的非物理GNN。我们根据有关学习特性的物理知识比较并选择有意义的GNN合并方法。通过量子机械计算计算出的分子特性证明了物理池函数的影响。我们还将结果与最近的SET2Set合并方法进行了比较。我们建议使用总和池来预测取决于分子大小的性能并比较分子大小无关的属性的池函数。总体而言，我们表明物理池功能的使用显着增强了概括。

分子表示学习（MRL）是建立机器学习与化学科学之间联系的关键步骤。特别是，它将分子编码为保留分子结构和特征的数值向量，在其上可以执行下游任务（例如，属性预测）。最近，MRL取得了相当大的进步，尤其是在基于深的分子图学习方法中。在这项调查中，我们系统地回顾了这些基于图的分子表示技术。具体而言，我们首先介绍2D和3D图分子数据集的数据和功能。然后，我们总结了专门为MRL设计的方法，并将其分为四种策略。此外，我们讨论了MRL支持的一些典型化学应用。为了促进该快速发展领域的研究，我们还列出了论文中的基准和常用数据集。最后，我们分享我们对未来研究方向的想法。

Advancements in neural machinery have led to a wide range of algorithmic solutions for molecular property prediction. Two classes of models in particular have yielded promising results: neural networks applied to computed molecular fingerprints or expert-crafted descriptors, and graph convolutional neural networks that construct a learned molecular representation by operating on the graph structure of the molecule.However, recent literature has yet to clearly determine which of these two methods is superior when generalizing to new chemical space. Furthermore, prior research has

机器学习（ML）已经证明了用于准确和结晶材料的准确性能预测的承诺。为了化学结构的高度精确的ML型号的化学结构属性预测，需要具有足够样品的数据集。然而，获得昂贵的化学性质的获得和充分数据可以是昂贵的令人昂贵的，这大大限制了ML模型的性能。通过计算机视觉和黑暗语言处理中数据增强的成功，我们开发了奥古里希姆：数据八级化图书馆化学结构。引入了弃头晶系统和分子的增强方法，其可以对基于指纹的ML模型和图形神经网络（GNNS）进行脱颖而出。我们表明，使用我们的增强策略意义地提高了ML模型的性能，特别是在使用GNNS时，我们开发的增强件在训练期间可以用作广告插件模块，并在用不同的GNN实施时证明了有效性。模型通过Theauglichem图书馆。基于Python的封装我们实现了EugliChem：用于化学结构的数据增强库，可公开获取：https：//github.com/baratilab/auglichem.1

分子表示学习有助于多个下游任务，例如分子性质预测和药物设计。为了适当地代表分子，图形对比学习是一个有前途的范式，因为它利用自我监督信号并没有人类注释要求。但是，先前的作品未能将基本域名知识纳入图表语义，因此忽略了具有共同属性的原子之间的相关性，但不通过键连接连接。为了解决这些问题，我们构建化学元素知识图（KG），总结元素之间的微观关联，并提出了一种用于分子代表学习的新颖知识增强的对比学习（KCL）框架。 KCL框架由三个模块组成。第一个模块，知识引导的图形增强，基于化学元素kg增强原始分子图。第二模块，知识意识的图形表示，利用用于原始分子图的公共曲线图编码器和通过神经网络（KMPNN）的知识感知消息来提取分子表示来编码增强分子图中的复杂信息。最终模块是一种对比目标，在那里我们在分子图的这两个视图之间最大化协议。广泛的实验表明，KCL获得了八个分子数据集上的最先进基线的优异性能。可视化实验适当地解释了在增强分子图中从原子和属性中了解的KCL。我们的代码和数据可用于补充材料。

近年来，基于Weisfeiler-Leman算法的算法和神经架构，是一个众所周知的Graph同构问题的启发式问题，它成为具有图形和关系数据的机器学习的强大工具。在这里，我们全面概述了机器学习设置中的算法的使用，专注于监督的制度。我们讨论了理论背景，展示了如何将其用于监督的图形和节点表示学习，讨论最近的扩展，并概述算法的连接（置换 - ）方面的神经结构。此外，我们概述了当前的应用和未来方向，以刺激进一步的研究。

Ionic Liquids (ILs) provide a promising solution for CO$_2$ capture and storage to mitigate global warming. However, identifying and designing the high-capacity IL from the giant chemical space requires expensive, and exhaustive simulations and experiments. Machine learning (ML) can accelerate the process of searching for desirable ionic molecules through accurate and efficient property predictions in a data-driven manner. But existing descriptors and ML models for the ionic molecule suffer from the inefficient adaptation of molecular graph structure. Besides, few works have investigated the explainability of ML models to help understand the learned features that can guide the design of efficient ionic molecules. In this work, we develop both fingerprint-based ML models and Graph Neural Networks (GNNs) to predict the CO$_2$ absorption in ILs. Fingerprint works on graph structure at the feature extraction stage, while GNNs directly handle molecule structure in both the feature extraction and model prediction stage. We show that our method outperforms previous ML models by reaching a high accuracy (MAE of 0.0137, $R^2$ of 0.9884). Furthermore, we take the advantage of GNNs feature representation and develop a substructure-based explanation method that provides insight into how each chemical fragments within IL molecules contribute to the CO$_2$ absorption prediction of ML models. We also show that our explanation result agrees with some ground truth from the theoretical reaction mechanism of CO$_2$ absorption in ILs, which can advise on the design of novel and efficient functional ILs in the future.

这项工作考虑了在属性关系图（ARG）上表示表示的任务。 ARG中的节点和边缘都与属性/功能相关联，允许ARG编码在实际应用中广泛观察到的丰富结构信息。现有的图形神经网络提供了有限的能力，可以在局部结构环境中捕获复杂的相互作用，从而阻碍他们利用ARG的表达能力。我们提出了Motif卷积模块（MCM），这是一种新的基于基线的图表表示技术，以更好地利用本地结构信息。处理连续边缘和节点功能的能力是MCM比现有基于基础图案的模型的优势之一。 MCM以无监督的方式构建了一个主题词汇，并部署了一种新型的主题卷积操作，以提取单个节点的局部结构上下文，然后将其用于通过多层perceptron学习高级节点表示，并在图神经网络中传递消息。与其他图形学习方法进行分类的合成图相比，我们的方法在捕获结构环境方面要好得多。我们还通过将其应用于几个分子基准来证明我们方法的性能和解释性优势。

Many applications of machine learning require a model to make accurate predictions on test examples that are distributionally different from training ones, while task-specific labels are scarce during training. An effective approach to this challenge is to pre-train a model on related tasks where data is abundant, and then fine-tune it on a downstream task of interest. While pre-training has been effective in many language and vision domains, it remains an open question how to effectively use pre-training on graph datasets. In this paper, we develop a new strategy and self-supervised methods for pre-training Graph Neural Networks (GNNs). The key to the success of our strategy is to pre-train an expressive GNN at the level of individual nodes as well as entire graphs so that the GNN can learn useful local and global representations simultaneously. We systematically study pre-training on multiple graph classification datasets. We find that naïve strategies, which pre-train GNNs at the level of either entire graphs or individual nodes, give limited improvement and can even lead to negative transfer on many downstream tasks. In contrast, our strategy avoids negative transfer and improves generalization significantly across downstream tasks, leading up to 9.4% absolute improvements in ROC-AUC over non-pre-trained models and achieving state-of-the-art performance for molecular property prediction and protein function prediction.However, pre-training on graph datasets remains a hard challenge. Several key studies (

The accurate prediction of physicochemical properties of chemical compounds in mixtures (such as the activity coefficient at infinite dilution $\gamma_{ij}^\infty$) is essential for developing novel and more sustainable chemical processes. In this work, we analyze the performance of previously-proposed GNN-based models for the prediction of $\gamma_{ij}^\infty$, and compare them with several mechanistic models in a series of 9 isothermal studies. Moreover, we develop the Gibbs-Helmholtz Graph Neural Network (GH-GNN) model for predicting $\ln \gamma_{ij}^\infty$ of molecular systems at different temperatures. Our method combines the simplicity of a Gibbs-Helmholtz-derived expression with a series of graph neural networks that incorporate explicit molecular and intermolecular descriptors for capturing dispersion and hydrogen bonding effects. We have trained this model using experimentally determined $\ln \gamma_{ij}^\infty$ data of 40,219 binary-systems involving 1032 solutes and 866 solvents, overall showing superior performance compared to the popular UNIFAC-Dortmund model. We analyze the performance of GH-GNN for continuous and discrete inter/extrapolation and give indications for the model's applicability domain and expected accuracy. In general, GH-GNN is able to produce accurate predictions for extrapolated binary-systems if at least 25 systems with the same combination of solute-solvent chemical classes are contained in the training set and a similarity indicator above 0.35 is also present. This model and its applicability domain recommendations have been made open-source at https://github.com/edgarsmdn/GH-GNN.

自我监督学习（SSL）是一种通过利用数据中固有的监督来学习数据表示的方法。这种学习方法是药物领域的焦点，由于耗时且昂贵的实验，缺乏带注释的数据。使用巨大未标记数据的SSL显示出在分子属性预测方面表现出色的性能，但存在一些问题。 （1）现有的SSL模型是大规模的；在计算资源不足的情况下实现SSL有限制。 （2）在大多数情况下，它们不利用3D结构信息进行分子表示学习。药物的活性与药物分子的结构密切相关。但是，大多数当前模型不使用3D信息或部分使用它。 （3）以前对分子进行对比学习的模型使用置换原子和键的增强。因此，具有不同特征的分子可以在相同的阳性样品中。我们提出了一个新颖的对比学习框架，用于分子属性预测的小规模3D图对比度学习（3DGCL），以解决上述问题。 3DGCL通过不改变药物语义的预训练过程来反映分子的结构来学习分子表示。仅使用1,128个样本用于预训练数据和100万个模型参数，我们在四个回归基准数据集中实现了最先进或可比性的性能。广泛的实验表明，基于化学知识的3D结构信息对于用于财产预测的分子表示学习至关重要。

通过定向消息传递通过方向消息通过的图形神经网络最近在多个分子特性预测任务上设置了最先进的技术。然而，它们依赖于通常不可用的原子位置信息，并获得它通常非常昂贵甚至不可能。在本文中，我们提出了合成坐标，使得能够使用高级GNN而不需要真正的分子配置。我们提出了两个距离作为合成坐标：使用个性化PageRank的对称变体指定分子配置的粗糙范围和基于图的距离的距离界限。为了利用距离和角度信息，我们提出了一种将正常图形神经网络转换为定向MPNN的方法。我们表明，通过这种转变，我们可以将正常图形神经网络的误差减少55％在锌基准。我们还通过在SMP和DimeNet ++模型中纳入合成坐标，在锌和自由QM9上设定了最新技术。我们的实现可在线获取。

Supervised learning on molecules has incredible potential to be useful in chemistry, drug discovery, and materials science. Luckily, several promising and closely related neural network models invariant to molecular symmetries have already been described in the literature. These models learn a message passing algorithm and aggregation procedure to compute a function of their entire input graph. At this point, the next step is to find a particularly effective variant of this general approach and apply it to chemical prediction benchmarks until we either solve them or reach the limits of the approach. In this paper, we reformulate existing models into a single common framework we call Message Passing Neural Networks (MPNNs) and explore additional novel variations within this framework. Using MPNNs we demonstrate state of the art results on an important molecular property prediction benchmark; these results are strong enough that we believe future work should focus on datasets with larger molecules or more accurate ground truth labels.Recently, large scale quantum chemistry calculation and molecular dynamics simulations coupled with advances in high throughput experiments have begun to generate data at an unprecedented rate. Most classical techniques do not make effective use of the larger amounts of data that are now available. The time is ripe to apply more powerful and flexible machine learning methods to these problems, assuming we can find models with suitable inductive biases. The symmetries of atomic systems suggest neural networks that operate on graph structured data and are invariant to graph isomorphism might also be appropriate for molecules. Sufficiently successful models could someday help automate challenging chemical search problems in drug discovery or materials science.In this paper, our goal is to demonstrate effective machine learning models for chemical prediction problems

图表神经网络（GNN）已被广泛用于学习图形结构数据的矢量表示，并实现比传统方法更好的任务性能。 GNN的基础是消息传递过程，它将节点中的信息传播到其邻居。由于该过程每层进行一个步骤，因此节点之间的信息传播的范围在下层中很小，并且它朝向更高的层扩展。因此，GNN模型必须深入地捕获图中的全局结构信息。另一方面，众所周知，深入的GNN模型遭受性能下降，因为它们丢失了节点的本地信息，这对于良好的模型性能至关重要，通过许多消息传递步骤。在本研究中，我们提出了用于图形级分类任务的多级注意汇总（MLAP），这可以适应图表中的本地和全局结构信息。对于每个消息传递步骤，它具有注意池层，通过统一层方格图表示来计算最终图表示。 MLAP架构允许模型利用具有多个级别的本地图形的结构信息，因为它在由于过度的过天气丢失时保留了层面信息。我们的实验结果表明，与基线架构相比，MLAP架构提高了图形分类性能。此外，图表表示的分析表明，来自多个级别的地方的聚合信息确实具有提高学习图表表示的可怜的潜力。

基于深度学习的分子建模的最新进步令人兴奋地加速硅药发现。可获得血清的生成模型，构建原子原子和键合或逐片键的分子。然而，许多药物发现项目需要固定的支架以存在于所生成的分子中，并纳入该约束仅探讨了该约束。在这里，我们提出了一种基于图形的模型，其自然地支持支架作为生成过程的初始种子，这是可能的，因为它不调节在发电历史上。我们的实验表明，Moler与最先进的方法进行了相当的方法，在无约会的分子优化任务上，并且在基于脚手架的任务上优于它们，而不是比现有方法从培训和样本更快的数量级。此外，我们展示了许多看似小设计选择对整体性能的影响。