Haoran Liu was a research intern at NEC Laboratories America, Inc. while studying at Texas A&M University.

Posts

Rethinking Molecular Drug Design: From Generation to Control

Designing drug molecules is no longer just about generation, but control. NEC Laboratories America introduces MolDiffdAE, a diffusion-based framework that enables precise, multi-objective tuning of 3D molecular properties. By learning a semantic space, researchers can efficiently guide design, accelerating drug discovery and exploration of chemical space.

Uncertainty-Guided Latent Diagnostic Trajectory Learning for Sequential Clinical Diagnosis

Clinical diagnosis requires sequential evidence acquisition under uncertainty. However, most Large Language Model (LLM) based diagnostic systems assume fully observed patient information and therefore do not explicitly model how clinical evidence should be sequentially acquired over time. Even when diagnosis is formulated as a sequential decision process, it is still challenging to learn effective diagnostic trajectories. This is because the space of possible evidence-acquisition paths is relatively large, while clinical datasets rarely provide explicit supervision information for desirable diagnostic paths. To this end, we formulate sequential diagnosis as a Latent Diagnostic Trajectory Learning (LDTL) framework based on a planning LLM agent and a diagnostic LLM agent. For the diagnostic LLM agent, diagnostic action sequences are treated as latent paths and we introduce a posterior distribution that prioritizes trajectories providing more diagnostic information. The planning LLM agent is then trained to follow this distribution, encouraging coherent diagnostic trajectories that progressively reduce uncertainty. Experiments on the MIMIC-CDM benchmark demonstrate that our proposed LDTL framework outperforms existing baselines in diagnostic accuracy under a sequential clinical diagnosis setting, while requiring fewer diagnostic tests. Furthermore, ablation studies highlight the critical role of trajectory-level posterior alignment in achieving these improvements.

Disentangled autoencoding equivariant diffusion model for controllable generation of 3D molecules

Controlled generation of 3D molecules is highly valuable in drug design, enabling targeted modifications that preserve core structure and binding-relevant geometry while improving developability-related properties. While equivariant diffusion models achieve state-of-the-art de novo 3D molecule generation, reliably controlling multiple molecular properties remains challenging. A key limitation is structural: diffusion models typically lack an explicit latent space for targeted manipulation. We propose a semantics-guided equivariant autoencoding diffusion model that learns a disentangled semantic embedding of 3D molecules via an auxiliary encoder, to achieve fine-grained control over the generative denoising process. This semantic embedding enables efficient retrieval, random generation and controlled generation. By directly manipulating the embedding, we effectively steer the molecular generation toward desired compositions, shapes and physicochemical properties, and further enhance the generation quality with retrieval-augmented generation (RAG) using the embedding as the query. Importantly, the disentangled embedding offers significant advantages for joint manipulation of multiple properties. Experiments demonstrate precise and data-efficient property control while preserving non-targeted properties.

Learning Disentangled Equivariant Representation for Explicitly Controllable 3D Molecule Generation

We consider the conditional generation of 3D drug-like molecules with explicit control over molecular properties such as drug-like properties (e.g., Quantitative Estimate of Druglikenessor Synthetic Accessibility score) and effectively binding to specific protein sites. To tackle this problem, we propose an E(3)-equivariant Wasserstein autoencoder and factorize thelatent space of our generative model into two disentangled aspects: molecular properties and the remaining structural context of 3D molecules. Our model ensures explicit control over these molecular attributes while maintaining equivariance of coordinate representation and invariance of data likelihood. Furthermore, we introduce a novel alignment-based coordinate loss to adapt equivariant networks for auto-regressive denovo 3D molecule generation from scratch. Extensive experiments validate our model’s effectiveness on property-guidedand context-guided molecule generation, both for de-novo 3D molecule design and structure-based drug discovery against protein targets.