Combined substituent number utilized machine learning for the development of antimicrobial agent.

The utilization of machine learning has a potential to improve the environment of the development of antimicrobial agents. For practical use of machine learning, it is important that the conversion of molecules information to an appropriate descriptor because too informative descriptor requires enormous computation time and experiments for gathering data, whereas a less informative descriptor has problems in validity. In this study, we utilized a descriptor only focused on substituent.

Total Synthesis of Azulene Derivative, a Blue Pigment Isolated from , and Colorant Application of Its Aqueous Dispersion.

Safety concerns in the food industry have increased the demand for natural food colorants. However, the application ranges of natural blue colorants are insufficient because they are scarce in nature, and the currently available natural blue dyes are limited to water-soluble products. In this study, we investigated a fat-soluble azulene derivative isolated from the mushroom as a potential candidate for a natural blue colorant.

Proselfs depend more on model-based than model-free learning in a non-social probabilistic state-transition task.

Humans form complex societies in which we routinely engage in social decision-making regarding the allocation of resources among ourselves and others. One dimension that characterizes social decision-making in particular is whether to prioritize self-interest or respect for others-proself or prosocial. What causes this individual difference in social value orientation? Recent developments in the social dual-process theory argue that social decision-making is characterized by its underlying domain-general learning systems: the model-free and model-based systems.

Single-Cell RNA Sequencing of Arabidopsis Leaf Tissues Identifies Multiple Specialized Cell Types: Idioblast Myrosin Cells and Potential Glucosinolate-Producing Cells.

The glucosinolate-myrosinase defense system (GMDS), characteristic of Brassicales, is involved in plant defense. Previous single-cell transcriptomic analyses have reported the expression profiles of multiple GMDS-related cell types (i.e.

Anomalously Efficient Dehydrogenation of NH on Ir and Ir.

Gas-phase reactions of iridium cluster cations, Ir ( = 1-8), with ammonia are studied at near-thermal energies. In single collision reactions, dehydrogenation of NH proceeds at = 1-5, and in particular, Ir and Ir are found to be significantly reactive. This size dependence is quite different from those of other platinum group metal cluster cations, where usually only the dimers are able to dehydrogenate NH.

Total synthesis and antimicrobial evaluation of (+)-hygrophorone B and its analogues.

This paper describes the synthesis and evaluation of lead compounds with a new chemical skeleton that is not found in conventional antimicrobial agents. The biologically attractive cyclopentenoid (+)-hygrophorone B, isolated from the fruiting bodies of Hygrophorus abieticola, and its analogues were synthesized in a longer linear sequence of twelve steps, starting from a cyclopentenone derivative. This synthesis involved the following crucial steps: (i) oximation of a ketone to stabilize the requisite aldehyde to install a side chain and (ii) coupling of an aldehyde with a side chain to assemble the desired hygrophorone.

Dissociative Adsorption of N onto Size-Selected Ti and TiO ( ≤ 16) toward Nitrogen Fixation.

The reactivity of titanium cluster ions and their oxides with molecular dinitrogen was examined using a tandem-type mass spectrometer at a low collision energy of 0.5 eV. The clusters can adsorb dinitrogen and release a titanium atom to consume the obtained excess energy.

Activation of Methane by Tungsten Carbide and Nitride Cluster Cations.

Gas-phase reactions of tungsten carbide and nitride cluster cations, WC ( = 1-5, ≤ 5) and WN ( = 1-6, ≤ 2), with methane are investigated at near thermal energies. Most of the clusters react readily with CH to form WCH or WNCH under single collision conditions, in contrast to the almost no reactivity of pure tungsten clusters. This result indicates that the introduction of carbon or nitrogen atoms can enhance the reactivity of tungsten clusters toward the CH dehydrogenation.

Inverted Vibrational and Rotational Excitation of CN(BΣ) Produced through Superexcited Ion-Pair States of MCN (M = Na, K, Rb).

This paper reports an energy-partition mechanism in dissociative excitation of alkali cyanide molecules, MCN (M = Rb, K, Na), to produce CN(BΣ) and M(sS) ( = 5, 4, and 3 for Rb, K, and Na, respectively) in collision with Kr metastable atoms, Kr(P). Both the vibrational and rotational distributions of CN(BΣ) produced in the reactions of RbCN and KCN were inverted as being peaked at = 1 and ' = 35, respectively, where ' and ' are the vibrational and the rotational quantum numbers of CN(BΣ), respectively. According to a state crossing model, it was derived that CN(BΣ) is produced by predissociation through a superexcited ion-pair state, CN(3Σ)·M(S), followed by an adiabatic transition to a repulsive state correlating to the dissociation limit of CN(BΣ) + M(sS).

Geometry control of size selected Pt clusters bound to Si substrate surface by cluster impact deposition.

Geometry of platinum clusters, Pt (N = 30-71), supported on a silicon substrate was investigated, aiming to control the geometry. The supported clusters were prepared by the impact of size-selected Pt onto the substrate at a given collision energy (cluster-impact deposition), and their geometry was observed by means of a scanning-tunneling microscope. Even at the collision energy of 1 eV per Pt atom, sufficiently strong Pt-Si interaction between Pt (N = 30 and 45) and the Si substrate allows them to be supported as close-packed monatomic-layered Pt disks, while at N = 60, multilayered shapes exist besides the monatomic-layered shape, the fraction of which increases at N = 71.

Growth Stage-dependent Bacterial Communities in Soybean Plant Tissues: Methylorubrum Transiently Dominated in the Flowering Stage of the Soybean Shoot.

Plant-associated bacteria are critical for plant growth and health. However, the effects of plant growth stages on the bacterial community remain unclear. Analyses of the microbiome associated with field-grown soybean revealed a marked shift in the bacterial community during the growth stages.

Dehydrogenation of Methane by Partially Oxidized Tungsten Cluster Cations: High Reactivity Comparable to That of Platinum Cluster Cations.

Gas-phase reactivity of pure and partially oxidized tungsten atomic and cluster cations, W ( = 1-6) and WO ( = 1-5, ≤ 6), with methane is studied at the collision energies from 0.1 to 1.0 eV under single collision conditions.

Charge-state analysis of small barium-oxide clusters by x-ray absorption spectroscopy.

Small barium-oxide clusters [Formula: see text] are studied by mass spectrometry and x-ray absorption spectroscopy (XAS) to discuss stability of the clusters and oxidation state of constituent atoms. It is found that clusters with bulk composition, n  =  m, are stable, which can accommodate one or two excess oxygen atoms additionally as manifested by n  =  m  +  1 and m  +  2 species in the mass spectrum. XAS spectra of [Formula: see text] and [Formula: see text] reveal that the oxidation state of barium atoms stays at  +2 (the bulk BaO value) even after binding excess oxygen, whereas spectral features originating from oxygen exhibit composition dependence.

Gas-Phase Reactions of Copper Oxide Cluster Cations with Ammonia: Selective Catalytic Oxidation to Nitrogen and Water Molecules.

Reactions of copper oxide cluster cations, Cu O ( n = 3-7; m ≤ 5), with ammonia, NH, are studied at near thermal energies using a guided ion beam tandem mass spectrometer. The single-collision reactions of specific clusters such as CuO, CuO, CuO, CuO, and CuO give rise to the release of HO after NH adsorption efficiently and result in the formation of Cu O NH. These Cu O clusters commonly have Cu average oxidation numbers of 1.

Bimetallic Ag-Pt Sub-nanometer Supported Clusters as Highly Efficient and Robust Oxidation Catalysts.

A combined experimental and theoretical investigation of Ag-Pt sub-nanometer clusters as heterogeneous catalysts in the CO→CO reaction (COox) is presented. Ag Pt and Ag Pt clusters are size-selected in the gas phase, deposited on an ultrathin amorphous alumina support, and tested as catalysts experimentally under realistic conditions and by first-principles simulations at realistic coverage. In situ GISAXS/TPRx demonstrates that the clusters do not sinter or deactivate even after prolonged exposure to reactants at high temperature, and present comparable, extremely high COox catalytic efficiency.

Nanosecond pump-probe device for time-resolved serial femtosecond crystallography developed at SACLA.

X-ray free-electron lasers (XFELs) have opened new opportunities for time-resolved X-ray crystallography. Here a nanosecond optical-pump XFEL-probe device developed for time-resolved serial femtosecond crystallography (TR-SFX) studies of photo-induced reactions in proteins at the SPring-8 Angstrom Compact free-electron LAser (SACLA) is reported. The optical-fiber-based system is a good choice for a quick setup in a limited beam time and allows pump illumination from two directions to achieve high excitation efficiency of protein microcrystals.

Causal mechanisms of seismo-EM phenomena during the 1965-1967 Matsushiro earthquake swarm.

The 1965-1967 Matsushiro earthquake swarm in central Japan exhibited two unique characteristics. The first was a hydro-mechanical crust rupture resulting from degassing, volume expansion of CO/water, and a crack opening within the critically stressed crust under a strike-slip stress. The other was, despite the lower total seismic energy, the occurrence of complexed seismo-electromagnetic (seismo-EM) phenomena of the geomagnetic intensity increase, unusual earthquake lights (EQLs) and atmospheric electric field (AEF) variations.

Effects of Second-Metal (Al, V, Co) Doping on the NO Reactivity of Small Rhodium Cluster Cations.

Reactions of pure and doped rhodium cluster cations, RhX (n = 2-6; X = Al, V, Co, Rh), with NO molecules were investigated at near-thermal energy using a guided ion beam tandem mass spectrometer. We found that the doping with Al and V increases the total reaction cross section mostly. Under single-collision conditions, RhX reacts with NO to produce RhN with release of metal monoxide, XO, whereas RhX (n = 3-6) adsorb NO.

Microcrystal delivery by pulsed liquid droplet for serial femtosecond crystallography.

A liquid-droplet injector has been developed that delivers pristine microcrystals to an X-ray irradiation area for conducting serial femtosecond crystallography (SFX) with an X-ray free-electron laser (XFEL). By finely tuning the pulsed liquid droplets in time and space, a high hit rate of the XFEL pulses to microcrystals in the droplets was achieved for measurements using 5 µm tetragonal lysozyme crystals, which produced 4265 indexable diffraction images in about 30 min. The structure was determined at a resolution of 2.

Reactions of Ti- and V-Doped Cu Cluster Cations with Nitric Oxide and Oxygen: Size Dependence and Preferential NO Adsorption.

Reactions of copper cluster cations doped with an early transition metal atom, CunTi(+) (n = 4-15) and CunV(+) (n = 5-14, 16), with NO and O2 were investigated at a near-thermal collision energy using a guided ion beam tandem mass spectrometer. Most of the clusters adsorb NO and O2 under single collision conditions, and this reaction is often followed by the release of Cu atoms. For both Ti- and V-doped Cu clusters, the total cross sections for the reaction with NO increase gradually with the cluster size up to n ≈ 11 and then decrease rapidly, whereas those with O2 are almost constant in n ≤ 12 and then decrease.

Stability of Aluminum-Doped Copper Cluster Cations and Their Reactivity toward NO and O2.

Aluminum-doped copper cluster cations, CunAl(+), were produced via an ion sputtering method and analyzed by mass spectrometry. The measured size distributions show that Cu6Al(+) and Cu18Al(+) are highly stable species, which can be understood in terms of the electronic subshell 1P and 2S closings, respectively. Furthermore, the reactions of size-selected CunAl(+) (n = 4-6 and 8-16) with NO and O2 were studied at near thermal energies by using a tandem-type mass spectrometer.

Ferromagnetic spin coupling in the chromium dimer cation: measurements by photodissociation spectroscopy combined with coupled-cluster calculations.

The magnetic coupling of the chromium dimer cation, Cr2 (+), has been an outstanding problem for decades. An optical absorption spectrum of Cr2 (+) has been obtained by photodissociation spectroscopy in the photon-energy range from 2.0 to 5.

Catalytic oxidation of CO with N2O on isolated copper cluster anions.

A catalytic redox reaction involving N2O and CO on size-selected copper cluster anions, Cun(-), was investigated in the gas phase using a guided ion-beam tandem mass spectrometer. When Cun(-) is exposed to a mixture of N2O and CO, CunO(-) is produced via the decomposition of N2O. Increase of the CO partial pressure results in the reproduction of Cun(-) and decrease of CunO(-) through the oxidation of CO.

Systematic study on novel catalytic activity of CO oxidation driven by strong electronic interaction between the monatomic-layered Pt30 cluster disk and the Si substrate.

Catalytic activity of thermal CO oxidation was studied for monatomic-layered platinum cluster disks, Pt30, bonded to the (111) surface of a silicon substrate. Temperature-programmed desorption (TPD) measurements were repeated for a given cluster sample with a systematic change in the reactant amounts supplied, and the peaks observed in the TPD spectra were deconvoluted so as to obtain probabilities of individual reactions. It was concluded that this system possesses an ability of low-temperature reductive activation of oxygen molecules, which is one of the critical steps in the CO oxidation.