Procrystalline Self-Assembly of Desymmetrized Pentaphenylcyclopentadiene.

The interplay between the molecular shape and the intermolecular interaction plays a decisive role in self-assembled structures. Recently, inherent randomness of low ordered assemblies, resulting from lack of short- and long-range periodicities, has attracted significant attention due to the unique structural, electronic, and mechanical properties. Here, we present procrystalline self-assemblies of pentaphenyl cyclopentadienyl derivatives on Ag(111) and Au(111) with scanning tunneling microscopy, operating at 4.3 K under ultrahigh vacuum conditions. Two examples, using 5-fold symmetric molecules substituted with methyl or fluorine groups, show that weak interactions, such as π-π stacking, CH-π interactions, and CH···F hydrogen bonding, play a pivotal role in formation of the procrystalline assembly. Our results may give insights into the intricate relationship between the molecular shape and the intermolecular interaction in the formation of non-crystalline assemblies.

On-Surface Synthesis of Polyene-Linked Porphyrin Cooligomer.

π-Conjugated molecules are viewed as fundamental components in forthcoming molecular nanoelectronics in which semiconducting functional units are linked to each other via metallic molecular wires. However, it is still challenging to construct such block cooligomers on the surface. Here, we present a synthesis of [18]-polyene-linked Zn-porphyrin cooligomers via a two-step reaction of the alkyl groups on Cu(111) and Cu(110). Nonyl groups (-C9H19) substituted at the 5,15-meso positions of Zn-porphyrin were first transformed to alkenyl groups (-C9H10) by dehydrogenation. Subsequently, homocoupling of the terminal -CH2 groups resulted in the formation of extended [18]-polyene-linked porphyrin cooligomers. The structures of the products at each reaction step were investigated by bond-resolved scanning tunneling microscopy at low temperatures. A combination of angle-resolved photoemission spectroscopy and density functional theory calculations revealed the metallic property of the all trans [18]-polyene linker on Cu(110). This finding may provide an approach to fabricate complex nanocarbon structures on the surface.

Machine-learning descriptor search on the density of states profile of bimetallic alloy systems and comparison with the d-band center theory.

In this study, the electronic density of states (DOSs) calculated with density functional theory (DFT) were analyzed by the machine-learning techniques. More than 400 pure metal and bimetallic alloy systems were calculated with DFT, and obtained the surface DOSs and the CH3 adsorption energy (Ead). By fitting the Gaussian functions to the DOS, multiple descriptors, such as the Gaussian peak positions, heights, and widths were extracted. Several regression methods, such as the least absolute shrinkage of selection operator (LASSO), random-forest, gradient-boosting, and extra-tree were used to find the relationship between these descriptors and the Ead. The results show that the energy position of the peaks in the d-projected DOS is the most important descriptor, in agreement with the previously known d-band center theory. It was also shown that the peak position in d-projected DOS improves the regression model in addition to the d-band center, since it reduces the regression error.

The Homeodomain-Leucine Zipper Subfamily I Contributes to Leaf Age- and Time-Dependent Resistance to Pathogens in Arabidopsis thaliana.

In Arabidopsis thaliana (Arabidopsis), nonhost resistance (NHR) is influenced by both leaf age and the moment of inoculation. While the circadian clock and photoperiod have been linked to the time-dependent regulation of NHR in Arabidopsis, the mechanism underlying leaf age-dependent NHR remains unclear. In this study, we investigated leaf age-dependent NHR to Pyricularia oryzae in Arabidopsis. Our findings revealed that this NHR type is regulated by both miR156-dependent and miR156-independent pathways. To identify the key players, we utilized rice-FOX Arabidopsis lines and identified the rice HD-Zip I OsHOX6 gene. Notably, OsHOX6 expression confers robust NHR to P. oryzae and Colletotrichum nymphaeae in Arabidopsis, with its effect being contingent upon leaf age. Moreover, we explored the role of AtHB7 and AtHB12, the Arabidopsis closest homologues of OsHOX6, by studying mutants and overexpressors in Arabidopsis-C. higginsianum interaction. AtHB7 and AtHB12 were found to contribute to both penetration resistance and post-penetration resistance to C. higginsianum in a leaf age- and time-dependent manner. These findings highlight the involvement of HD-Zip I AtHB7 and AtHB12, well-known regulators of development and abiotic stress responses, in biotic stress responses in Arabidopsis.

Magnetism in Nonplanar Zigzag Edge Termini of Graphene Nanoribbons.

Graphene nanoribbons (GNRs) and nanographenes synthesized by on-surface reactions using tailor-made molecular precursors offer an ideal playground for a study of magnetism towards nano-spintronics. Although the zigzag edge of GNRs has been known to host magnetism, the underlying metal substrates usually veil the edge-induced Kondo effect. Here, we report the on-surface synthesis of unprecedented, π-extended 7-armchair GNRs using 7-bromo-12-(10-bromoanthracen-9-yl)tetraphene as the precursor. Characterization by scanning tunneling microscopy/spectroscopy revealed unique rearrangement reactions leading to pentagon- or pentagon/heptagon-incorporated, nonplanar zigzag termini, which demonstrated Kondo resonances even on bare Au(111). Density functional theory calculations indicate that the nonplanar structure significantly reduces the interaction between the zigzag terminus and the Au(111) surface, leading to a recovery of the spin localization of the zigzag edge. Such a distortion of planar GNR structures offers a degree of freedom to control the magnetism on metal substrates.

Critical impacts of interfacial water on C-H activation in photocatalytic methane conversion.

On-site and on-demand photocatalytic methane conversion under ambient conditions is one of the urgent global challenges for the sustainable use of ubiquitous methane resources. However, the lack of microscopic knowledge on its reaction mechanism prevents the development of engineering strategies for methane photocatalysis. Combining real-time mass spectrometry and operando infrared absorption spectroscopy with ab initio molecular dynamics simulations, here we report key molecular-level insights into photocatalytic green utilization of methane. Activation of the robust C-H bond of methane is hardly induced by the direct interaction with photogenerated holes trapped at the surface of photocatalyst; instead, the C-H activation is significantly promoted by the photoactivated interfacial water species. The interfacial water hydrates and properly stabilizes hydrocarbon radical intermediates, thereby suppressing their overstabilization. Owing to these water-assisted effects, the photocatalytic conversion rates of methane under wet conditions are dramatically improved by typically more than 30 times at ambient temperatures (~300 K) and pressures (~1 atm) in comparison to those under dry conditions. This study sheds new light on the role of interfacial water and provides a firm basis for design strategies for non-thermal heterogeneous catalysis of methane under ambient conditions.

Study Protocol for a Multicenter, Randomized Controlled Trial to Improve Upper Extremity Hemiparesis in Chronic Stroke Patients by One-to-One Training (NEURO®) with Repetitive Transcranial Magnetic Stimulation.

During recovery from upper limb motor paralysis after stroke, it is important to (1) set the exercise difficulty level according to the motor paralysis severity, (2) provide adequate exercises, and (3) motivate the patient to achieve the goal. However, these factors have not been well-formulated. This multicenter, randomized controlled trial study aims to examine the therapeutic effects of these three factors on patients undergoing a novel intervention using repetitive transcranial magnetic stimulation and intensive one-to-one training (NEURO®) and to formulate a corresponding research protocol. The control group will receive conventional NEURO® occupational therapy. In the intervention group, four practice plans will be selected according to the Fugl-Meyer assessment (FMA-UE) scores of the upper extremity. The goal is to predict the post-treatment outcomes based on the pre-treatment FMA-UE scores. Based on the degree of difficulty and amount of practice required, we can formulate a practice plan to promote upper limb motor recovery. This occupational therapy plan will be less influenced by the therapist's skill, facilitating effective rehabilitation. The study findings may be utilized to promote upper limb motor paralysis recovery and provide a basis for proposing activities of daily living adapted to upper limb function.

Epidermal CCA1 and PMR5 contribute to nonhost resistance in Arabidopsis.

Nonhost resistance (NHR) is the most robust and durable resistance in plants, but its spatiotemporal regulation is poorly understood. The circadian clock functions in a tissue-specific manner and regulates individual physiological processes in plants. Using mutant and RNA-seq analyses, we revealed a role of CIRCADIAN CLOCK ASSOCIATED1 (CCA1) in tissue-specific and time-of-day-specific regulation of NHR to Pyricularia oryzae (syn. Magnaporthe oryzae) in Arabidopsis thaliana (Arabidopsis). Targeted perturbation of CCA1 function in epidermis compromised time-of-day-specific regulation of NHR to P. oryzae in Arabidopsis. RNA-seq analysis showed that P. oryzae inoculation alters the transcriptome in penetration 2 (pen2) plants and identified POWDERY MILDEW RESISTANCE 5 (PMR5) as a candidate gene of direct targets of CCA1. Time-of-day-specific penetration resistance to P. oryzae was reduced in Arabidopsis pen2 pmr5 mutant plants. These findings suggest that epidermal CCA1 and PMR5 contribute to the establishment of time-of-day-specific NHR to P. oryzae in Arabidopsis.

Favorable Role of the Metal-Support Perimeter Region in Electrochemical NH3 Synthesis: A Density Functional Theory Study on Ru/BaCeO3.

The catalytic electrochemical synthesis of NH3 on Ru/BaCeO3 was investigated using density functional theory. The competition between NH3 formation and the hydrogen evolution reaction (HER) is a key for a high NH3 formation rate. Our calculations show that H adsorbs more strongly than N2 at the Ru particle moiety, while the adsorption of N2 is stronger than the H adsorption at the Ru/BaCeO3 perimeter, a model for the triple-phase boundary that is proposed to be an active site by experimental studies. This indicates that, while the HER is more favorable at the Ru particle moiety, it should be suppressed at the Ru/BaCeO3 perimeter. We also calculated the Gibbs free energy changes along the NH3 formation and found that the N2H formation, the NHNH2 formation, and the NH3 formation steps have a relatively large Gibbs energy change. Therefore, these are possible candidates for the potential-determining step. The calculated equilibrium potential (U = -0.70 V, vs RHE) is in reasonable agreement with experiments. We also evaluated the reaction energy (ΔE) and the activation barrier (E a) of the N2H formation at several sites. ΔE and E a were high at the Ru particle moiety (ΔE = 1.18 eV and E a = 1.38 eV) but became low (ΔE = 0.32 eV and E a = 1.31 eV) at the Ru/BaCeO3 perimeter. These provide the atomic-scale mechanism how the proton conduction in BaCeO3 assists the electrochemical NH3 synthesis.

Heterogeneous catalyst design by generative adversarial network and first-principles based microkinetics.

Microkinetic analysis based on density functional theory (DFT) was combined with a generative adversarial network (GAN) to enable the artificial proposal of heterogeneous catalysts based on the DFT-calculated dataset. The approach was applied to the NH3 formation reaction on Rh-Ru alloy surfaces as an example. The NH3 formation turnover frequency (TOF) was calculated by DFT-based microkinetics. Six elementary reactions, namely, N2 dissociation, H2 dissociation, NHx (x = 1-3) formation, and NH3 desorption, were explicitly considered, and their reaction energies were evaluated by DFT calculations. Based on the TOF values and atomic compositions, new alloy surfaces were generated using the GAN. This approach successfully generated the surfaces that were not included in the initial dataset but exhibited higher TOF values. The N2 dissociation reaction was more exothermic for the generated surfaces, leading to higher TOF. The present study demonstrates that the automatic improvement of catalyst materials is possible using DFT calculations and GAN sample generation.

On-Surface Synthesis of Porphyrin-Complex Multi-Block Co-Oligomers by Defluorinative Coupling.

On-surface chemical reaction has become a very powerful technique to synthesize nanostructures by linking small molecules in the bottom-up approach. Given the fact that most reactants are simultaneously activated at certain temperatures, a sequential reaction in a controlled way has remained challenging. Here, we present an on-surface synthesis of multi-block co-oligomers from trifluoromethyl (CF3 ) substituted porphyrin metal complexes. The oligomerization on Au(111) is demonstrated with a combination of bond-resolved scanning probe microscopy and density functional theory (DFT) calculations. Even after the first oligomerization of single monomer unit, the termini of the oligomer keep the CF3 group, which can be used as a reactant for further coupling in a sequential order. Consequently, copper, cobalt, and palladium complexes of bisanthracene-fused porphyrin oligomers were linked with each other in a designed order.

Photoperiod Following Inoculation of Arabidopsis with Pyricularia oryzae (syn. Magnaporthe oryzae) Influences on the Plant-Pathogen Interaction.

In plant-pathogen interactions, a proper light environment affects the establishment of defense responses in plants. In our previous experiments, we found that nonhost resistance (NHR) to Pyricularia oryzae Cav. in Arabidopsis thaliana (L.) Heynh. (Arabidopsis), in diurnal conditions, varies with the inoculation time. Moreover, we indicated that the circadian clock plays an important role in regulating time-of-day differences in NHR to P. oryzae in Arabidopsis. However, the involvement of photoperiod in regulating NHR was still not understood. To determine the photoperiod role, we performed the experiments in continuous light and darkness during the early Arabidopsis-P. oryzae interaction. We found that the light period after the inoculation in the evening enhanced the resistance to penetration. However, the dark period after the inoculation in the morning suppressed the penetration resistance. Furthermore, the genetic analysis indicated that jasmonic acid, reactive oxygen species, and tryptophan-derived metabolite(s) contribute to the photoperiod regulation of NHR in Arabidopsis. The present results denote that photoperiod plays an important role in regulating time-of-day differences in NHR to P. oryzae in Arabidopsis.

Manipulation of CO adsorption over Me1/CeO2 by heterocation doping: Key roles of single-atom adsorption energy.

The performance of metal atoms chemically bonded to oxide supports cannot be explained solely by the intrinsic properties of the metals such as the d-band center. Herein, we present an in-depth study of the correlation between metal-oxide interactions and the properties of the supported metal using CO adsorption on Me1 (Fe1, Co1, and Ni1) loaded over CeO2 (111) doped with divalent (Ca, Sr, and Ba), trivalent (Al, Ga, Sc, Y, and La), and quadrivalent (Hf and Zr) heterocations. CO adsorption over Me1 is strongly dependent on the binding energies of Me1. Two factors led to this trend. First, the extent of the Me1-surface oxygen (Me1-O) bond relaxation during CO adsorption played a key role. Second, the d-band center shifted drastically because of charge transfer to the oxides. The shift is related to the oxophilicity of metals. Adsorption energies of Me1 over oxides include the contributions of the factors described above. Therefore, we can predict the activities of Me1 using the strength of anchoring by oxide supports. Results show that smaller ionic radii of the doped heterocations were associated with more tightly bound Me1. This finding sheds light on the possibility of heterocation-doping manipulating the reactivity of the Me1 catalyst based on theoretical predictions.

Genetic Variations and Neuropathologic Features of Patients with PRKN Mutations.

BACKGROUND: Mutations in PRKN are the most common cause of autosomal recessive juvenile parkinsonism. The objective of this study was to investigate the association between genotype and pathology in patients with PRKN mutations. METHODS: We performed a sequence and copy number variation analysis of PRKN, mRNA transcripts, Parkin protein expression, and neuropathology in 8 autopsied patients. RESULTS: All the patients harbored biallelic PRKN mutations. Two patients were homozygous and heterozygous, respectively, for the missense mutation p.C431F. Seven patients had exon rearrangements, including 2 patients from a single family who harbored a homozygous deletion of exon 4, and 3 patients who carried a homozygous duplication of exons 6-7, a homozygous duplication of exons 10-11, and a heterozygous duplication of exons 2-4. In the other 2 patients, we found a compound heterozygous duplication of exon 2, deletion of exon 3, and a heterozygous duplication of exon 2. However, sequencing of cDNA prepared from mRNA revealed 2 different transcripts derived from triplication of exon 2 and deletion of exons 2-3 and from duplication of exons 2-4 and deletion of exons 3-4. Western blotting and immunohistochemistry revealed faint or no expression of Parkin in their brains. In the substantia nigra pars compacta, a subfield-specific pattern of neuronal loss and mild gliosis were evident. Lewy bodies were found in 3 patients. Peripheral sensory neuronopathy was a feature. CONCLUSIONS: Genomic and mRNA analysis is needed to identify the PRKN mutations. Variable mutations may result in no or little production of mature Parkin and the histopathologic features may be similar. © 2021 International Parkinson and Movement Disorder Society.

Theoretical prediction by DFT and experimental observation of heterocation-doping effects on hydrogen adsorption and migration over the CeO2(111) surface.

Hydrogen (H) atom adsorption and migration over the CeO2-based materials surface are of great importance because of its wide applications to catalytic reactions and electrochemical devices. Therefore, comprehensive knowledge for controlling the H atom adsorption and migration over CeO2-based materials is crucially important. For controlling H atom adsorption and migration, we investigated irreducible divalent, trivalent, and quadrivalent heterocation-doping effects on H atom adsorption and migration over the CeO2(111) surface using density functional theory (DFT) calculations. Results revealed that the electron-deficient lattice oxygen (Olat) and the flexible CeO2 matrix played key roles in strong adsorption of H atoms. Heterocations with smaller valence and smaller ionic radius induced the electron-deficient Olat. In addition, smaller cation doping enhanced the CeO2 matrix flexibility. Moreover, we confirmed the influence of H atom adsorption controlled by doping on surface proton migration (i.e. surface protonics) and catalytic reaction involving surface protonics (NH3 synthesis in an electric field). Results confirmed clear correlation between H atom adsorption energy and surface protonics.

Tryptophan-derived metabolites and BAK1 separately contribute to Arabidopsis postinvasive immunity against Alternaria brassicicola.

Nonhost resistance of Arabidopsis thaliana against the hemibiotrophic fungus Colletotrichum tropicale requires PEN2-dependent preinvasive resistance and CYP71A12 and CYP71A13-dependent postinvasive resistance, which both rely on tryptophan (Trp) metabolism. We here revealed that CYP71A12, CYP71A13 and PAD3 are critical for Arabidopsis' postinvasive basal resistance toward the necrotrophic Alternaria brassicicola. Consistent with this, gene expression and metabolite analyses suggested that the invasion by A. brassicicola triggered the CYP71A12-dependent production of indole-3-carboxylic acid derivatives and the PAD3 and CYP71A13-dependent production of camalexin. We next addressed the activation of the CYP71A12 and PAD3-dependent postinvasive resistance. We found that bak1-5 mutation significantly reduced postinvasive resistance against A. brassicicola, indicating that pattern recognition contributes to activation of this second defense-layer. However, the bak1-5 mutation had no detectable effects on the Trp-metabolism triggered by the fungal penetration. Together with this, further comparative gene expression analyses suggested that pathogen invasion in Arabidopsis activates (1) CYP71A12 and PAD3-related antifungal metabolism that is not hampered by bak1-5, and (2) a bak1-5 sensitive immune pathway that activates the expression of antimicrobial proteins.

Whitish daytime radiative cooling using diffuse reflection of non-resonant silica nanoshells.

Daytime radiative cooling offers efficient passive cooling of objects by tailoring their spectral responses, holding great promise for green photonics applications. A specular reflector has been utilized in cooling devices to minimize sunlight absorption, but such a glaring surface is visually less appealing, thus undesirable for public use. Here, by exploiting strong diffuse reflection of silica nanoshells in a polymer matrix, daytime radiative cooling below the ambient temperature is experimentally demonstrated, while showing whitish color under sunlight. The cooling device consists of a poly(methyl methacrylate) layer with randomly distributed silica nanoshells and a polydimethylsiloxane (PDMS) layer on an Ag mirror. The non-resonant nanoshells exhibit uniform diffuse reflection over the solar spectrum, while fully transparent for a selective thermal radiation from the underneath PDMS layer. In the temperature measurement under the sunlight irradiation, the device shows 2.3 °C cooler than the ambient, which is comparable to or even better than the conventional device without the nanoshells. Our approach provides a simple yet powerful nanophotonic structure for realizing a scalable and practical daytime radiative cooling device without a glaring reflective surface.

Agglomeration Suppression of a Fe-Supported Catalyst and its Utilization for Low-Temperature Ammonia Synthesis in an Electric Field.

Fe-supported heterogeneous catalysts are used for various reactions, including ammonia synthesis, Fischer-Tropsch synthesis, and exhaust gas cleaning. For the practical use of Fe-supported catalysts, suppression of Fe particle agglomeration is the most important issue to be resolved. As described herein, we found that Al doping in an oxide support suppresses agglomeration of the supported Fe particle. Experimental and computational studies revealed two tradeoff Al doping effects: the Fe particle size decreased and remained without agglomeration by virtue of the anchoring effect of doped Al. Also, some Fe atoms anchored by Al cannot function as an active site because of bonding with oxygen atoms. Using an appropriate amount of Al doping is effective for increasing the number of active Fe sites and catalytic activity. This optimized catalyst showed high practical activity and stability for low-temperature ammonia synthesis in an electric field. The optimized catalyst of 12.5 wt % Fe/Ce0.4Al0.1Zr0.5O2-δ showed the highest ammonia synthesis rate (2.3 mmol g-1 h-1) achieved to date under mild conditions (464 K, 0.9 MPa) in an electric field among the Fe catalysts reported.

Heteroatom doping effects on interaction of H2O and CeO2 (111) surfaces studied using density functional theory: Key roles of ionic radius and dispersion.

Understanding heteroatom doping effects on the interaction between H2O and cerium oxide (ceria, CeO2) surfaces is crucially important for elucidating heterogeneous catalytic reactions of CeO2-based oxides. Surfaces of CeO2 (111) doped with quadrivalent (Ti, Zr), trivalent (Al, Ga, Sc, Y, La), or divalent (Ca, Sr, Ba) cations are investigated using density functional theory (DFT) calculations modified for onsite Coulomb interactions (DFT + U). Trivalent (except for Al) and divalent cation doping induces the formation of intrinsic oxygen vacancy (Ovac), which is backfilled easily by H2O. Partially OH-terminated surfaces are formed. Furthermore, dissociative adsorption of H2O is simulated on the OH terminated surfaces (for trivalent or divalent cation doped models) and pure surfaces (for Al and quadrivalent cation doped surfaces). The ionic radius is crucially important. In fact, H2O dissociates spontaneously on the small cations. Although a slight change is induced by doping as for the H2O adsorption energy at Ce sites, the H2O dissociative adsorption at Ce sites is well-assisted by dopants with a smaller ionic radius. In terms of the amount of promoted Ce sites, the arrangement of dopant sites is also fundamentally important.

CCA1 and LHY contribute to nonhost resistance to Pyricularia oryzae (syn. Magnaporthe oryzae) in Arabidopsis thaliana.

The circadian clock enables plants to adapt to their environment and control numerous physiological processes, including plant-pathogen interactions. However, it is unknown if the circadian clock controls nonhost resistance (NHR) in plants. To find out, we analyzed microarray data with the web-based tool DIURNAL to reveal that NHR-related genes show rhythmic expression patterns in the absence of a pathogen challenge. Our clock mutant analyses found that cca1-1 lhy-11 double mutant showed compromised NHR to Pyricularia oryzae, suggesting that two components of the circadian clock, CCA1 and LHY, are involved in regulating penetration resistance in Arabidopsis thaliana. By analyzing pen2 double mutants, we revealed that CCA1 contributes to time-of-day-dependent penetration resistance as a positive regulator and that LHY regulates post-penetration resistance as a positive regulator. Taken together, our results suggest that the circadian clock regulates the time-of-day-dependent NHR to P. oryzae and thus enables A. thaliana to counteract pathogen attacks.Abbreviations: EE: evening element; ETI: effector-triggered immunity; NHR: nonhost resistance; PAMP: pathogen-associated molecular pattern; PTI: PAMP-triggered immunity; SAR: systemic acquired resistance.