Molecular Design for Cardiac Cell Differentiation Using a Small Data Set and Decorated Shape Features.

The discovery of small organic compounds for inducing stem cell differentiation is a time- and resource-intensive process. While data science could, in principle, streamline the discovery of these compounds, novel approaches are required due to the difficulty of acquiring training data from large numbers of example compounds. In this paper, we present the design of a new compound for inducing cardiomyocyte differentiation using simple regression models trained with a data set containing only 80 examples.

Desensitization to commodity price fluctuations by product characteristics.

Little is known about how commodity price fluctuations transmit to the prices of products. In this paper we present a price dynamics model for a product which is in competition with a commodity. The price of the commodity is treated as a stochastic process.

Entropically driven melting of Cu-based 1D coordination polymers.

We investigated the melting behavior of four CPs with one-dimensional structures from a thermodynamic point-of-view. The difference in melting points depending on the crystal structures is observed. The interactions within the crystals were analyzed using DFT calculations.

Biomass-derived carbon dots as fluorescent quantum probes to visualize and modulate inflammation.

Quantum dots, which won the Nobel Prize in Chemistry, have recently gained significant attention in precision medicine due to their unique properties, such as size-tunable emission, high photostability, efficient light absorption, and vibrant luminescence. Consequently, there is a growing demand to identify new types of quantum dots from various sources and explore their potential applications as stimuli-responsive biosensors, biomolecular imaging probes, and targeted drug delivery agents. Biomass-waste-derived carbon quantum dots (CQDs) are an attractive alternative to conventional QDs, which often require expensive and toxic precursors, as they offer several merits in eco-friendly synthesis, preparation from renewable sources, and cost-effective production.

Suppression of Charge Recombination by Vertical Arrangement of A Donor Moiety on Flat Planar Dyes for Efficient Dye-Sensitized Solar Cells.

In dye-sensitized solar cells (DSSCs), flat planar dyes (e. g., highly light-harvesting porphyrins and corroles) with multiple anchoring groups are known to adopt a horizontal orientation on TiO through the multiple binding to TiO.

Extracellular calcium functions as a molecular glue for transmembrane helices to activate the scramblase Xkr4.

The "eat me" signal, phosphatidylserine is exposed on the surface of dying cells by phospholipid scrambling. Previously, we showed that the Xkr family protein Xkr4 is activated by caspase-mediated cleavage and binding of the XRCC4 fragment. Here, we show that extracellular calcium is an additional factor needed to activate Xkr4.

Exciton diffusion in amorphous organic semiconductors: Reducing simulation overheads with machine learning.

Simulations of exciton and charge hopping in amorphous organic materials involve numerous physical parameters. Each of these parameters must be computed from costly ab initio calculations before the simulation can commence, resulting in a significant computational overhead for studying exciton diffusion, especially in large and complex material datasets. While the idea of using machine learning to quickly predict these parameters has been explored previously, typical machine learning models require long training times, which ultimately contribute to simulation overheads.

Discovery of a phase-separating small molecule that selectively sequesters tubulin in cells.

Phase-separated membraneless organelles or biomolecular condensates play diverse functions in cells, however recapturing their characteristics using small organic molecules has been a challenge. In the present study, cell-lysate-based screening of 843 self-assembling small molecules led to the discovery of a simple organic molecule, named huezole, that forms liquid droplets to selectively sequester tubulin. Remarkably, this small molecule enters cultured human cells and prevents cell mitosis by forming tubulin-concentrating condensates in cells.

Intrinsic Hole Mobility in Luminescent Metal-Organic Frameworks and Its Application in Organic Light-Emitting Diodes.

Most metal-organic frameworks (MOFs) lack charge mobility, which is crucial for realizing their use in optoelectronic applications. This work proposes the design of a MOF using triarylamine-based ligands (Zr-NBP) as the lone pair electron spacer to enhance the hole mobility in the MOF while maintaining its luminescent properties. Zr-NBP has strong fluorescence with a good hole mobility of 1.

One-Pot, Room-Temperature Conversion of CO into Porous Metal-Organic Frameworks.

The conversion of CO into functional materials under ambient conditions is a major challenge to realize a carbon-neutral society. Metal-organic frameworks (MOFs) have been extensively studied as designable porous materials. Despite the fact that CO is an attractive renewable resource, the synthesis of MOFs from CO remains unexplored.

Caspase cleavage releases a nuclear protein fragment that stimulates phospholipid scrambling at the plasma membrane.

Phospholipid scrambling in dying cells promotes phosphatidylserine exposure, a critical process for efferocytosis. We previously identified the Xkr family protein Xkr4 as a phospholipid-scrambling protein, but its activation mechanisms remain unknown. Here we show that Xkr4 is activated in two steps: dimer formation by caspase-mediated cleavage and structural change caused by activating factors.

Discovery of Self-Assembling Small Molecules as Vaccine Adjuvants.

Immune potentiators, termed adjuvants, trigger early innate immune responses to ensure the generation of robust and long-lasting adaptive immune responses of vaccines. Presented here is a study that takes advantage of a self-assembling small-molecule library for the development of a novel vaccine adjuvant. Cell-based screening of the library and subsequent structural optimization led to the discovery of a simple, chemically tractable deoxycholate derivative (molecule 6, also named cholicamide) whose well-defined nanoassembly potently elicits innate immune responses in macrophages and dendritic cells.

Exploring the configuration spaces of surface materials using time-dependent diffraction patterns and unsupervised learning.

Computational methods for exploring the atomic configuration spaces of surface materials will lead to breakthroughs in nanotechnology and beyond. In order to develop such methods, especially ones utilizing machine learning approaches, descriptors which encode the structural features of the candidate configurations are required. In this paper, we propose the use of time-dependent electron diffraction simulations to create descriptors for the configurations of surface materials.

Disorder-robust bands from anisotropic orbitals in a coordination polymer semiconductor.

While the effects of structural disorder on the electronic properties of solids are poorly understood, it is widely accepted that spatially isotropic orbitals lead to robustness against disorder. In this paper, we use first-principles calculations to show that a cluster of occupied bands in the coordination polymer semiconductor β-copper(I) thiocyanate undergo relatively little fluctuation in the presence of thermal disorder-a surprising finding given that these bands are composed of spatially anisotropic d-orbitals. Analysis with the tight-binding method and a stochastic network model suggests that the robustness of these bands to the thermal disorder can be traced to the way in which these orbitals are aligned with respect to each other.

Materials informatics for self-assembly of functionalized organic precursors on metal surfaces.

Bottom-up fabrication via on-surface molecular self-assembly is a way to create defect-free, low-dimensional nanomaterials. For bottom-up fabrication to succeed, precursor molecules which correctly assemble into the target structure must be first identified. Here we present an informatics technique which connects self-assembled structures with particular chemical properties of the precursor molecules.

Construction of a Hierarchical Architecture of Covalent Organic Frameworks via a Postsynthetic Approach.

Covalent organic frameworks (COFs) represent an emerging class of crystalline porous materials that are constructed by the assembly of organic building blocks linked via covalent bonds. Several strategies have been developed for the construction of new COF structures; however, a facile approach to fabricate hierarchical COF architectures with controlled domain structures remains a significant challenge, and has not yet been achieved. In this study, a dynamic covalent chemistry (DCC)-based postsynthetic approach was employed at the solid-liquid interface to construct such structures.

A Hydroxamic Acid Anchoring Group for Durable Dye-Sensitized Solar Cells Incorporating a Cobalt Redox Shuttle.

A hydroxamic acid group has been employed for the first time as an anchoring group for cobalt-based dye-sensitized solar cells (DSSCs). The porphyrin dye YD2-o-C8HA including a hydroxamic acid anchoring group exhibited a power conversion efficiency (η) of 6.4 %, which is close to that of YD2-o-C8, a representative porphyrin dye incorporating a conventional carboxylic acid.

Chemical and entropic control on the molecular self-assembly process.

Molecular self-assembly refers to the spontaneous assembly of molecules into larger structures. In order to exploit molecular self-assembly for the bottom-up synthesis of nanomaterials, the effects of chemical control (strength of the directionality in the intermolecular interaction) and entropic control (temperature) on the self-assembly process should be clarified. Here we present a theoretical methodology that unambiguously distinguishes the effects of chemical and entropic control on the self-assembly of molecules adsorbed to metal surfaces.

State-space reduction and equivalence class sampling for a molecular self-assembly model.

Direct simulation of a model with a large state space will generate enormous volumes of data, much of which is not relevant to the questions under study. In this paper, we consider a molecular self-assembly model as a typical example of a large state-space model, and present a method for selectively retrieving 'target information' from this model. This method partitions the state space into equivalence classes, as identified by an appropriate equivalence relation.

Charge transport in organic crystals: critical role of correlated fluctuations unveiled by analysis of Feynman diagrams.

Organic crystals have unique charge transport properties that lie somewhere between delocalised band-type transport and localised hopping transport. In this paper, we use a stochastic tight-binding model to explore how dynamical disorder in organic crystals affects charge transport. By analysing the model in terms of Feynman diagrams (virtual processes), we expose the crucial role of correlated dynamical disorder to the charge transport dynamics in the model at short times in the order of a few hundred femtoseconds.

Effects of atomic collisions on the stoichiometry of thin films prepared by pulsed laser deposition.

We present an analytical model to quantitatively study the effect of collisions between the atoms of a plume and the molecules of a surrounding gas on the nonstoichiometry of lithium-containing oxide thin films deposited using pulsed laser deposition. A comparison of the experimental data and the model ascertain the inevitable loss of the lighter cation, leading to a nonstoichiometric reduction in the content of lighter cations in the films. Our model is the first analytic model of collision-induced plume expansion that can explain the partial oxygen pressure dependence of the Li content of a thin film.

Dephasing by a continuous-time random walk process.

Stochastic treatments of magnetic resonance spectroscopy and optical spectroscopy require evaluations of functions such as (exp(i ∫(0)(t) Q(s)ds)), where t is time, Q(s) is the value of a stochastic process at time s, and the angular brackets denote ensemble averaging. This paper gives an exact evaluation of these functions for the case where Q is a continuous-time random walk process. The continuous-time random walk describes an environment that undergoes slow steplike changes in time.

Non-Gaussian stochastic dynamics of spins and oscillators: a continuous-time random walk approach.

We consider separately a spin and an oscillator that are coupled to their environment. After a finite interval of random length, the state of the environment changes, and each change causes a random change in the resonance frequency of the spin or vibrational frequency of the oscillator. Mathematically, the evolution of these frequencies is described by a continuous-time random walk.

A stochastic, local mode study of neon-liquid surface collision dynamics.

Equations of motion for a fast, light rare gas atom passing over a liquid surface are derived and used to infer the dynamics of neon collisions with squalane and perfluorinated polyether surfaces from experimental data. The equations incorporate the local mode model of a liquid surface via a stochastic process and explicitly account for impulsive collisional energy loss to the surface. The equations predict angular distributions for scattering of neon that are in good quantitative agreement with experimental data.

A stochastic, local mode treatment of high-energy gas-liquid collisions.

The scattering angle distributions of high-energy molecular beams at the surfaces of three different liquids are treated in terms local mode theory. This is achieved by setting up a stochastic process modeling the effect of a superposition of local mode surface displacements on the incoming particle's trajectory. The results are found to be in good qualitative agreement with experiment, and directions for further work are indicated.