Time-correlation functions of stochastic three-sphere micromachines.

We discuss and compare the statistical properties of two stochastic three-sphere micromachines, i.e., odd micromachine and thermal micromachine.

Statistical formulation of the Onsager-Machlup variational principle.

Onsager's variational principle provides us with a systematic way to derive dynamical equations for various soft matter and active matter. By reformulating the Onsager-Machlup variational principle (OMVP), which is a time-global principle, we propose a new method to incorporate thermal fluctuations. To demonstrate the utility of the statistical formulation of OMVP, we obtain the diffusion constant of a Brownian particle embedded in a viscous fluid by maximizing the modified Onsager-Machlup integral for the surrounding fluid.

Irreversibility of stochastic state transitions in Langevin systems with odd elasticity.

Active microscopic objects, such as an enzyme molecule, are modeled by the Langevin system with the odd elasticity, in which energy injection from the substrate to the enzyme is described by the antisymmetric part of the elastic matrix. By applying the Onsager-Machlup integral and large deviation theory to the Langevin system with odd elasticity, we can calculate the cumulant generating function of the irreversibility of the state transition. For an N-component system, we obtain a formal expression of the cumulant generating function and demonstrate that the oddness λ, which quantifies the antisymmetric part of the elastic matrix, leads to higher-order cumulants that do not appear in a passive elastic system.

Toughening Ionic Polymer Using Bulky Alkylammonium Counterions and Comb Architecture.

Ionic interactions in ionic polymers, such as ionomers, polyelectrolytes, and polyampholytes, contribute to toughness in systems with high mobility and active ion dynamics, such as hydrogels and elastomers. However, it remains challenging to toughen rigid polymers through ionic interactions without lowering their elastic modulus through plasticization. Here, we present a strategy for toughening without sacrificing the elastic modulus by combining a comb polymer with bulky ammonium counterions.

Most probable path of an active Brownian particle.

In this study, we investigate the transition path of a free active Brownian particle (ABP) on a two-dimensional plane between two given states. The extremum conditions for the most probable path connecting the two states are derived using the Onsager-Machlup integral and its variational principle. We provide explicit solutions to these extremum conditions and demonstrate their nonuniqueness through an analogy with the pendulum equation indicating possible multiple paths.

Time-correlation functions for odd Langevin systems.

We investigate the statistical properties of fluctuations in active systems that are governed by nonsymmetric responses. Both an underdamped Langevin system with an odd resistance tensor and an overdamped Langevin system with an odd elastic tensor are studied. For a system in thermal equilibrium, the time-correlation functions should satisfy time-reversal symmetry and the antisymmetric parts of the correlation functions should vanish.

Self-organized swimming with odd elasticity.

We theoretically investigate self-oscillating waves of an active material, which were recently introduced as a nonsymmetric part of the elastic moduli, termed odd elasticity. Using Purcell's three-link swimmer model, we reveal that an odd-elastic filament at low Reynolds number can swim in a self-organized manner and that the time-periodic dynamics are characterized by a stable limit cycle generated by elastohydrodynamic interactions. Also, we consider a noisy shape gait and derive a swimming formula for a general elastic material in the Stokes regime with its elasticity modulus being represented by a nonsymmetric matrix, demonstrating that the odd elasticity produces biased net locomotion from random noise.

Nonreciprocality of a micromachine driven by a catalytic chemical reaction.

We propose a model that describes cyclic state transitions of a micromachine driven by a catalytic chemical reaction. We consider a mechanochemical coupling of variables representing the degree of a chemical reaction and the internal state of a micromachine. The total free energy consists of a tilted periodic potential and a mechanochemical coupling energy.

Repeated treatment with gefitinib and alectinib in a patient with multiple EGFR-mutant and ALK-mutant lung adenocarcinomas: A case report.

Multiple EGFR-mutant and ALK-mutant lung cancers are rare, and standard treatment has not been established because of the small number of cases. A 79-year-old man was found to harbor nodular shadows in right S1, right S5, and left S3. He was surgically diagnosed with stage IIB (pT3N0M0) EGFR G719X-mutant lung adenocarcinoma in left S3 and stage IA1 (pT1aN0M0) ALK-mutant lung adenocarcinoma in right S5.

Dynamics of a membrane coupled to an active fluid.

The dynamics of a membrane coupled to an active fluid on top of a substrate is considered theoretically. It is assumed that the director field of the active fluid has rotational symmetry in the membrane plane. This situation is likely to be relevant for in vitro reconstructed actomyosin-membrane system.

Long-term response with durvalumab after chemoradiotherapy for pulmonary pleomorphic carcinoma: A case report.

Pulmonary pleomorphic carcinoma (PPC) is a non-small-cell lung cancer, resistant to chemotherapy and no standard therapy has as yet been established. We herein report the case of a 59-year-old man with PPC who showed a long-term response with durvalumab after chemoradiotherapy. He was referred to our hospital with a mass shadow at the right upper lung.

Nonequilibrium probability flux of a thermally driven micromachine.

We discuss the nonequilibrium statistical mechanics of a thermally driven micromachine consisting of three spheres and two harmonic springs [Y. Hosaka et al., J.

Semi-hydrolysate of paper pulp without pretreatment enables a consolidated fermentation system with in situ product recovery for the production of butanol.

Utilization of lignocellulosic biomasses for biobutanol fermentation usually requires costly processes of pretreatment and enzymatic hydrolysis. In this study, paper pulp (93.2% glucan) was used as a starting biomass material to produce biobutanol.

Adhesive Hydrogel System Based on the Intercalation of Anionic Substituents into Layered Double Hydroxides.

Hydrogels comprising anionic substituents in their polymer network were synthesized and adhered to each other following application of layered double hydroxides (LDHs) onto their surfaces. The resulting systems displayed high adhesive strength and tolerance for changes in parameters like solvent, salt concentration, and temperature. In experiments involving hydrogels with bulky anionic substituents, it was confirmed that the efficiency of the intercalation of the anionic groups into the layered inorganic compound LDH determines the strength of the adhesion.

Three-disk microswimmer in a supported fluid membrane.

A model of three-disk micromachine swimming in a quasi-two-dimensional supported membrane is proposed. We calculate the average swimming velocity as a function of the disk size and the arm length. Due to the presence of the hydrodynamic screening length in the quasi-two-dimensional fluid, the geometric factor appearing in the average velocity exhibits three different asymptotic behaviors depending on the microswimmer size and the hydrodynamic screening length.

Thermal and active fluctuations of a compressible bilayer vesicle.

We discuss thermal and active fluctuations of a compressible bilayer vesicle by using the results of hydrodynamic theory for vesicles. Coupled Langevin equations for the membrane deformation and the density fields are employed to calculate the power spectral density matrix of membrane fluctuations. Thermal contribution is obtained by means of the fluctuation dissipation theorem, whereas active contribution is calculated from exponentially decaying time correlation functions of active random forces.

Lateral diffusion induced by active proteins in a biomembrane.

We discuss the hydrodynamic collective effects due to active protein molecules that are immersed in lipid bilayer membranes and modeled as stochastic force dipoles. We specifically take into account the presence of the bulk solvent that surrounds the two-dimensional fluid membrane. Two membrane geometries are considered: the free membrane case and the confined membrane case.

Anomalous diffusion in viscoelastic media with active force dipoles.

With the use of the "two-fluid model," we discuss anomalous diffusion induced by active force dipoles in viscoelastic media. Active force dipoles, such as proteins and bacteria, generate nonthermal fluctuating flows that lead to a substantial increment of the diffusion. Using the partial Green's function of the two-fluid model, we first obtain passive (thermal) two-point correlation functions such as the displacement cross-correlation function between the two-point particles separated by a finite distance.

Highly Tolerant and Durable Adhesion between Hydrogels Utilizing Intercalation of Cationic Substituents into Layered Inorganic Compounds.

Adhering hydrogel systems are important particularly in the medical field because they can be used as adhesives cross-linking between living tissues. In this research, hydrogels including cationic substituents prepared via free-radical polymerization were brought into contact after applying an aqueous dispersion of the layered inorganic compound Micromica to their surfaces. As a result, the hydrogels adhered to each other due to the intercalation of cationic substituents included in the gel networks into the interlayers of Micromica.

Dynamics of a membrane interacting with an active wall.

Active motions of a biological membrane can be induced by nonthermal fluctuations that occur in the outer environment of the membrane. We discuss the dynamics of a membrane interacting hydrodynamically with an active wall that exerts random velocities on the ambient fluid. Solving the hydrodynamic equations of a bound membrane, we first derive a dynamic equation for the membrane fluctuation amplitude in the presence of different types of walls.

Dynamics of two-component membranes surrounded by viscoelastic media.

We discuss the dynamics of two-component fluid membranes which are surrounded by viscoelastic media. We assume that membrane-embedded proteins can diffuse laterally and induce a local membrane curvature. The mean squared displacement of a tagged membrane segment is obtained as a generalized Einstein relation.