Department of Biophysics,

Faculty of Medicine,

Oita University

 
 

Our laboratory applies physical principles and computational methods to understand biological phenomena quantitatively, from single molecules to genomes and populations. Building on our long-standing work on nucleic acid dynamics, we currently pursue the following research themes.

1. Nucleic acid dynamics and G-quadruplexes

We study how DNA and RNA change their conformations through interactions with multivalent ions and proteins, using molecular dynamics simulations and statistical-mechanical analysis. A major focus is the G-quadruplex (G4), a non-canonical structure formed by guanine-rich sequences: we investigate counter-ion (K⁺) binding kinetics and the mechanisms of transitions among chair, basket and hybrid topologies. We also compare how G4-forming sequences are maintained or depleted across genomes, from viruses to eukaryotes (the "G4 paradox").

2. GM-MCMC and large-scale computing on Fugaku

To sample rare events such as conformational transitions efficiently, we develop a new Markov chain Monte Carlo framework (GM-MCMC). Large-scale simulations on the supercomputer Fugaku allow us to access time scales that are difficult to reach by conventional approaches.

3. Evolutionary genomics of aging and longevity

We compare aging-related proteins across animal phyla to characterize the modes of natural selection (purifying selection) underlying longevity evolution, and we analyze survival strategies in fluctuating environments (bet-hedging) theoretically.

4. Bayesian statistics and causal inference on clinical data

As a department within a medical school, we collaborate with clinical departments to apply Bayesian networks and causal inference to clinical databases, aiming to uncover the structure of disease risk factors.

5. AI for Science: machine learning for biophysics

We integrate machine learning with physical simulation, including score-based MCMC using graph neural networks (GNNs) and the evaluation of foundation-model representations for biological sequences.

Education

We teach Mathematics and Physics I–III and a physics laboratory course to first-year medical students. We also contribute to courses in medical informatics, information science and medical information systems for first-year students in medicine, nursing and advanced medical sciences. Through lectures, practical exercises and experiments, students develop foundational skills in mathematics, physics, experimental data analysis, basic statistics and information security.

Conceptual illustration of computational life science, with DNA, evolution, survival curves and clinical data surrounding a central computational science motif.

 

 

 

 

 

 

Contact: 1-1 Idaigaoka, Hasama-machi, Yufu, Oita 879-5593, Japan

 

e-mail: physics@oita-u.ac.jp