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Background and Aim: Small gastric subepithelial lesions (SELs) are sometimes encountered in daily esophagogastroduodenoscopy (EGD) practice, but whether once-annual or twice-annual endoscopy can provide sufficient follow-up remains unclear. Because follow-up based on small-SEL characteristics is important, this study clarified the natural history of gastric SELs less than 20 mm. Methods: This retrospective multicenter observation study conducted at 24 Japanese hospitals during April 2000 to March 2020 examined small gastric SELs of ≤20 mm diameter. The primary outcome was the rate of size increase of those SELs detected using EGD, with growth times assessed irrespective of SEL pathological diagnoses. Results: We examined 824 cases with tumors of 1–5 mm diameter in 298 (36.2%) cases, 6–10 mm in 344 (41.7%) cases, 11–15 mm in 112 (13.6%) cases, and 16–20 mm in 70 (8.50%) cases. An increase of small gastric SELs was observed in 70/824 patients (8.5%). The SELs larger than 6 mm increased, even after 10 years. No-change and increasing groups had no significantly different malignant findings at diagnosis. In cases of gastrointestinal stromal tumors (GISTs), internal cystic change in endoscopic ultrasound (EUS) is a risk factor for an increased tumor size. The predictive tumor growth cutoff size at initial diagnosis was 13.5 mm. Conclusions: Small gastric SELs less than 20 mm have an approximately 8.5% chance of increase. Predictive markers for GIST growth are tumor size ≥13.5 mm and internal cystic change in EUS.

This post-marketing surveillance (PMS) was initiated in Japan to identify factors affecting the safety and effectiveness of pembrolizumab monotherapy in patients with advanced non-small cell lung cancer (NSCLC) with programmed cell death ligand-1 (PD-L1) expression. This PMS was conducted from December 2016 to June 2019 at 717 centers across Japan. Patients with unresectable advanced/recurrent NSCLC who received pembrolizumab monotherapy as first-line (1L) treatment for PD-L1-expressing tumors (Tumor Proportion Score [TPS] ≥ 50%) or second-line or later (2L+) treatment for tumors with PD-L1 TPS ≥ 1% were enrolled and followed up for 1 year. Of 2805 registered patients, 2740 and 2400 comprised the safety and effectiveness analysis sets, respectively. The median age (range) was 69 (27-92) years; 55.7% and 29.2% of patients experienced treatment-related adverse events and adverse events of special interest (AEOSIs), respectively. More common AEOSIs included interstitial lung disease, endocrine disorders, liver dysfunction, colitis/severe diarrhea, infusion reactions, and severe skin disorders. The frequency of experiencing ≥2 AEOSIs was low (1L, 6.5%; 2L+, 2.8%). Most AEOSIs occurred within 150 days after initiation of pembrolizumab monotherapy. At 1-year follow-up, the objective response rate was 39.2% (1L, 51.5%; 2L+, 30.0%). In conclusion, the 1-year safety and effectiveness of pembrolizumab monotherapy in patients with unresectable advanced/recurrent NSCLC as 1L treatment for tumors with PD-L1 TPS ≥ 50% and 2L+ treatment for tumors with PD-L1 TPS ≥ 1% were similar to those reported in phase 2/3 trials.

We created dual interactive sites in a porous coordination network using a CuI cluster and a rotation-restricted ligand, tetra(3-pyridyl)phenylmethane (3-TPPM). The dual interactive sites of iodide and Cu ions can adsorb I2 via four-step processes including two chemisorption processes. Initially, one I2 molecule was physisorbed in a pore and successively chemisorbed on iodide sites of the pore surface, and then the next I2 molecule was physisorbed and chemisorbed on Cu ions to form a cross-linked network. We revealed the four-step I2 diffusion process by single-crystal X-ray structure determination and spectroscopic kinetic analysis.

In condensed matter, phase separation is strongly related to ferroelasticity, ferroelectricity, ferromagnetism, electron correlation, and crystallography. These ferroics are important for nano-electronic devices such as non-volatile memory. However, the quantitative information regarding the lattice (atomic) structure at the border of phase separation is unclear in many cases. Thus, to design electronic devices on the molecular level, a quantitative relationship must be established between the lattice and the electrons. Herein, we elucidated a PdII–PdIV/PdIII–PdIII phase transition and phase separation mechanism for [Pd(cptn)2Br]Br2 (cptn = 1R,2R-diaminocyclopentane), propagated through a hydrogen-bonding network. Although the Pd···Pd distance was used to determine the electronic state, the differences in the Pd···Pd distance and the optical gap between Mott–Hubbard (MH) and charge-density-wave (CDW) states were only 0.012 Å and 0.17 eV, respectively. The N–H···Br···H–N hydrogen-bonding network functioned as a jack, adjusting the structural difference dynamically, and allowing visible ferroelastic phase transition/separation in a fluctuating N2 gas flow. In addition, the effect of the phase separation on the spin susceptibility and electrical conductivity were clarified to represent the quasi-epitaxial crystals among CDW–MH states. These results indicate that the phase transitions and separations could be controlled via modifications at the atomic and molecular levels, such as the addition of hydrogen bonding.

A new high temperature testing system was developed to evaluate high temperature deformation behavior in hot stamping process with high accuracy using a hybrid heating system consist of direct resistance heating and high-frequency induction heating. The uniform temperature distribution was achieved in the sheet steel tensile test specimen. The typical hot stamping thermal history was successfully simulated with the combination of the hybrid heating system and the gas cooling system. The strain distribution in high temperature deformation was confirmed to be uniform in the parallel portion of the specimen and the developed testing system may contribute to improving the accuracy in hot stamping CAE analysis.

Chiral supramolecular metal–organic frameworks (SMOFs), i.e., AlaNDI-Ca micro-/nanocrystals have been synthesized via solvothermal reaction using alanine-based naphthalene diimide (NDI) ligands and calcium nitrate. Interestingly, chiral self-discrimination is observed upon mixing two enantiomeric ligands with calcium nitrate due to the thermodynamic preference of heterochiral SMOFs over homochiral analogs. Upon irradiation with UV light, the conductivity of SMOFs micro-/nanocrystals significantly increases and their color changes from yellow to dark brown, due to the electron-transfer-related chemical processes inside the SMOF and/or photo-induced radical formation in NDI ligands, while they are not responsive to visible light. Heterochiral AlaNDI-Ca micro-/nanocrystals with a large band gap exhibit excellent photoswitching properties, due to the reversible generation and depletion of radicals upon exposure to UV light or in the dark, respectively. To our knowledge, photodetecting MOFs for optoelectronics are extremely rare, and herein we have firstly quantitatively characterized single crystalline SMOF photodiodes with redox NDI ligands with regard to their visible-blind UV photodetecting properties with high photoresponsivity and detectivity, which exhibit superior performances in comparison with precedent MOF-based photodetectors. These findings pave the way for applications of multifunctional micro-/nanoscaled MOFs in next-generation optoelectronics.

An N-Fmoc and C-tBu-protected glutamate (1) bearing a phenanthrene moiety at the side residue crystalizes and gels to afford hetero- and homochiral assemblies, respectively, depending on its optical purity or solvent. When a non-stoichiometric mixture of enantiomers of 1 in acetonitrile was treated with the conditions that leave a mixture of gel and supernatant, it exhibited the self-disproportionation of enantiomers with an enrichment of the major enantiomer in the gel. Under similar conditions, a racemic mixture of 1 also provided a gel/supernatant mixture, where the gel was enriched in either of L or D-form of 1 stochastically as the result of macroscopic chiral symmetry breaking in its gelation process.

Latency of chemical reactions is a crucial factor to control the physicochemical properties responsive to external stimuli such as light or heat. For example, when external triggers are applied to resin curing agents, curing reactions are required to be initiated instantly and uniformly. Latency is closely related to molecular architecture. In this study, we succeeded in controlling latency by tuning solubility of ionic liquid reagents in highly polar organic solvents by rational molecular packing design: implementation of a hydrogen bond network into the anion of the starting reagents raised the polymerization temperature because the solubility decreased. Because of the anion's hydrogen-bonding network, latency could be preserved even when a cation was replaced with less bulky ones. Theoretical analysis by DFT calculations supported the enhancement of latency induced by the implementation of a hydrogen bonding network in ionic liquid-type curing materials.

A flexible coordination polymer with a naphthalenediimide core exhibited reversible desorption–adsorption of solvent molecules and an enhancement of electrical conductivity (∼10−7 S cm−1) upon chemical reduction using hydrazine.

Chiral self-sorting has great potential for constructing new complex structures and determining chirality-dependent properties in multicomponent mixtures. However, it is still of great challenge to achieve high fidelity chiral self-discrimination. Besides, the researches on the coordination polymers or metal-organic frameworks for micro/nanooptoelectronics are still rare due to their low conductivity and difficulty in developing a rapid and simple scale-up synthetic method. Here, heterochiral supramolecular coordination networks (SCNs) were synthesized by the solvothermal reaction of naphthalene diimide enantiomers and cadmium iodide, using the chirality as a synthetic tuning parameter to control the morphologies. Intriguingly, heterochiral micro/nanocrystals exhibited photochromic and photodetecting properties. Furthermore, we also developed a simple and efficient doping method to enhance the conductivity and photoresponsivity of micro/nanocrystals using hydrazine. From experimental and theoretical studies, the mechanism was suggested as follows: the radicals in the singly occupied molecular orbital level of the ligands provide charge carriers that can undergo "through-space" transport between π-π stacked ligands and the electron transfer from adsorbed hydrazine to the SCNs results in reduction of energy gap, leading to increased conductivity. Our findings demonstrate a simple and powerful strategy for implementing coordination networks with redox ligands for micro/nanooptoelectronic applications.

We have successfully constructed hydrogen-bonded supramolecular assemblies based on a diprotonated saddle-distorted porphyrin (H4DPP2+) and redox-active molecules bearing a carboxylate group, such ...

We prepared coordination networks that show relatively strong emission with through-space charge-transfer (TSCT) transitions. Thermolysis of a kinetically assembled network with Cu2Br2 dimer connectors, which was assembled from a CuBr cluster and the Td ligand 4-4-tetrapyridyltetraphenylmethane (4-TPPM), generated a highly luminescent network composed of Cu+ connectors and 4-TPPM linkers with CuBr2- guests. We clarified that the electronic transitions in this network include TSCT in addition to the typical metal-ligand charge transfer (MLCT) observed in conventional Cu complexes.

The 2D coordination polymers, [Mn(salen)]2[PtII(CN)4]1-x[PtIV(CN)4(I2)]x (salen = N,N'-ethylenebis(salicylideneaminato), x = 0.18 (1), 0.45 (2), 0.85 (3)), have been synthesized via consecutive oxidative additions of iodine to the 2D undulating layers in [Mn(salen)]2[PtII(CN)4]. The presence of I-Pt-I chains perpendicular to the layers and the inhomogeneity of individual I-Pt-I sites were demonstrated. The I-Pt-I chains in 3 give rise to an absorption band involving the excitation that arises from an antibonding nature orbital to the corresponding bonding nature orbital between iodides in the I-Pt-I bridging units. Moreover, variable-temperature X-ray powder diffraction patterns and Raman spectra for 1 and 2 indicate that some I-Pt-I sites display different vibrational energies that are associated with the contraction of the zigzag 2D layers.

Cutaneous electrogastrography (EGG) is used in clinical and physiological fields to noninvasively measure the electrical activity of the stomach and intestines. Dipole models that mathematically express the electrical field characteristics generated by the stomach and intestines have been developed to investigate the relationship between the electrical control activity (ECA) (slow waves) shown in EGG and the internal gastric electrical activity. However, these models require a mathematical description of the movement of an annular band of dipoles, which limits the shape that can be modeled. In this study, we propose a novel polygonally meshed dipole model to conveniently reproduce ECA based on the movement of the annular band in complex shapes, such as the shape of the stomach and intestines, constructed in three-dimensional (3D) space. We show that the proposed model can reproduce ECA simulation results similar to those obtained using conventional models. Moreover, we show that the proposed model can reproduce the ECA produced by a complex geometrical shape, such as the shape of the intestines. The study results indicate that ECA simulations can be conducted based on structures that more closely resemble real organs than those used in conventional dipole models, with which, because of their intrinsic construction, it would be difficult to include realistic complex shapes, using the mathematical description of the movement of an annular band of dipoles. Our findings provide a powerful new approach for computer simulations based on the electric dipole model.

Trimethylamine N-oxide (Me3NO) could selectively remove only one CO ligand from fac-[Re(N^N)(CO)3(PR2R')]+ (N^N = diimine ligand), whereby only the CO ligand in the trans position to the phosphorus ligand was selectively removed to give cis,trans-[ReI(N^N)(CO)2(PR2R')(L)] n+ in good yields. This decarbonylation reaction using Me3NO was found to be especially useful for synthesizing biscarbonyl Re(I) complexes with electron-withdrawing groups in the diimine ligand, which could not be synthesized or were obtained only in low yields by the photochemical method. Me3NO also selectively removed the carbonyl ligands in the trans position to the phosphorus ligands from the edge Re(I) complex units, which have the fac-[Re(N^N)(CO)3(PR2R')]+ structure, in linear-shaped Re(I) multinuclear complexes. This reaction was successfully applied to synthesize a novel precursor with ring-shaped multinuclear Re complexes (Re-rings) comprising different kinds of Re(I) units. The newly synthesized Re-rings, which consist of one Re unit with a 4,4'-bis(trifluoromethyl)-2,2'-bipyridine (CF3bpy) ligand and one or two Re unit(s) with a 2,2'-bipyridine (bpy) ligand, showed almost quantitative excitation-energy harvesting ability from the Re unit(s) with bpy to that with CF3bpy.

A platinum(II) terpyridine complex having an enantiopure lactate anion afforded hydrated crystals l- or d-1hyd containing infinite chains of interacting Pt centers, while their dehydration induced crystal-to-crystal transformation into l- or d-1dehyd, respectively, exhibiting less significant Pt–Pt and/or ligand–ligand interactions. That transformation was accompanied by changes in the color as well as the photochemical reactivity of the crystals, where l-1dehyd showed higher reactivity than l-1hyd in the presence of amines under visible-light irradiation.

Buckybowls, which are represented by sumanene and corannulene, have attracted considerable attention for their unique bowl structures and interesting physicochemical properties. However, still few heteroatom-doped buckybowls have been reported to date. Here we show the successful synthesis of triazasumanene, an isoelectronic heteroanalogue of sumanene, which possesses a deeper bowl with stable bowl chirality and unique helical columnar packing in the crystal as an enantiopure form. In contrast, the crystal packing of the racemate shows a unidirectional columnar structure, which resembles that of the pristine sumanene. Doping of nitrogen atoms into the periphery of the sumanene framework also leads to perturbations of the electronic structure as shown by a significant decrease of the lowest unoccupied molecular orbital (LUMO) level and the optical band gap in comparison to all-carbon sumanene. The pyridine ring of triazasumanene shows unusual susceptibility towards acidic hydrolysis due to the highly strai...

The multistate redox-active/multi-interactive ligand 5,5',8,8'-tetra(4-pyridyl)-2,2'-(1,4-phenylene)bis-1H-perimidine (H2 TPP) was designed and synthesized. H2 TPP undergoes four one-electron oxidation steps, and was used for the preparation of a multistate redox-active coordination network in a solid-liquid interface reaction using molten Cd2+ salts. The multiple redox states of H2 TPP were confirmed spectroscopically by stepwise four-electron oxidation. Spectroscopic analysis indicated that the mixed-valence states of the ligand are class II on the UV/Vis/NIR timescale and borderline class II/class III on the ESR timescale.

An iron(III) complex having a dibenzotetraethyltetraamido macrocyclic ligand (DTTM4–), (NEt4)2[FeIII(DTTM)Cl] (1), was synthesized and characterized by crystallographic, spectroscopic, and electrochemical methods. Complex 1 has a square-pyramidal structure in the S = 3/2 spin state. The complex exhibited two reversible redox waves at +0.36 and +0.68 V (vs SCE) in the cyclic voltammogram measured in CH2Cl2 at room temperature. The stepwise oxidation of 1 using chemical oxidants allowed us to observe clear and distinct spectral changes with distinct isosbestic points for each step, in which oxidation occurred at the phenylenediamido moiety rather than the iron center. One-electron oxidation of 1 by 1 equiv of [RuIII(bpy)3](ClO4)3 (bpy = 2,2′-bipyridine) in CH2Cl2 afforded square-pyramidal (NEt4)[Fe(DTTM)Cl] (2), which was in the S = 1 spin state involving a ligand radical and showed a slightly distorted square-pyramidal structure. Complex 2 showed an intervalence charge-transfer band at 900 nm, which was as...

This paper reports additional properties of the electron donor molecule triselenathiafulvalene (TSTF) and its synthesis via a new route involving the precursor tetracarbomethoxytriselenathiafulvalene (TCMTSTF). The structural, electronic and computational properties of TSTF are fully profiled, and discussed in the context of the closely related archetypal electron donor molecule tetrathiafulvalene (TTF). TSTF was also incorporated into a charge transfer (CT) complex with the well-known electron acceptor 7,7,8,8-tetracyanoquinodimethane (TCNQ), to generate TSTF–TCNQ. In order to establish its position in the greater TXF–TCNQ series (where TXF = a tetrachalcogenafulvalene), spectral, electrochemical, magnetic, conductivity and computational studies were performed on TSTF and TSTF–TCNQ to extend what is known about the highly interesting and useful new donor molecule.

A C70 fragment (1) (C28H14) was synthesized by conversion of a C60 fragment sumanene, via ring expansion and annulation in 3 steps, the key step being the Wagner–Meerwein rearrangement of a five-membered ring to a six-membered one. Both theoretical and experimental investigations exhibited the shallower bowl structure of 1, resulting in the lower bowl inversion barrier than sumanene. It was also revealed that the indenopyrene skeleton largely contributed to the physical properties of 1.

By changing the rate of evaporation, two kinds of crystalline films composed of redox-active porous coordination networks (1 and 2) were selectively prepared on a gold-patterned substrate using a DMF solution of 2,5,8-tri(4-pyridyl)1,3-diazaphenalene and Cd(NO3)2. We found the highly sensitive humidity sensing ability of film 1. Single crystal structures and infrared spectroscopic analyses before and after hydration of a single crystal of 1 revealed the sensing mechanism: exchange of nitrate ions with water on Cd atoms occurred in hydrated conditions to generate a conductive cationic network.

Kinetic assembly is an important method for obtaining desired materials in chemical synthesis and material sciences. However, the application of this strategy to porous coordination networks has been limited. We highlight the kinetic assembly of porous coordination networks, which promote the production of interactive pore sites. These sites can activate or stabilize different guest molecules. The properties of interactive pores are exemplified by iodine chemisorption and small sulfur encapsulation. Using the interactive feature of these pores, we were able to trap small sulfur allotropes, such as S2, cyclo-S3, bent-S3, and S6, demonstrating their importance for the stabilization of unusual elemental species. Furthermore, several reactive elemental allotropes could also be incorporated into the interactive pores. Herein, we address the important aspects of creating interactive pore sites by kinetic assembly of porous coordination networks and present detailed case-by-case studies of small allotrope encapsulation.

[3]Cyclo-1,8-carbazolylene was found to undergo oxidative rearrangement by oxidation with 2,3-dichloro-5,6-dicyano-p-benzoquinone, giving a 9a-substituted carbazol-1-one derivative. This is the fir...

A multistate redox-active coordination network was prepared by stepwise synthesis via mechanochemical reaction to overcome the low solubility of ligands. Solid-state grinding between sparingly solu...

Rational engineering and assimilation of diverse chemo- and biocatalytic functionalities in a single nanostructure is highly desired for efficient multistep chemical reactions but has so far remained elusive. Here, we design and synthesize multimodal catalytic nanoreactors (MCNRs) based on a mesoporous metal-organic framework (MOF). The MCNRs consist of customizable metal nanocrystals and stably anchored enzymes in the mesopores, as well as coordinatively unsaturated cationic metal MOF nodes, all within a single nanoreactor space. The highly intimate and diverse catalytic mesoporous microenvironments and facile accessibility to the active site in the MCNR enables the cooperative and synergistic participation from different chemo- and biocatalytic components. This was shown by one-pot multistep cascade reactions involving a heterogeneous catalytic nitroaldol reaction followed by a [Pd/lipase]-catalyzed chemoenzymatic dynamic kinetic resolution to yield optically pure (>99 % ee) nitroalcohol derivatives in quantitative yields.

Self-assembly of a series of dimetallic sequences constructed on a backbone with two successive tyrosine moieties (Fmoc-M1 -M2 -CO2 H) revealed that the resultant morphology is clearly dependent on the metal sequence, where Re-containing sequences such as homometallic Fmoc-Re-Re-CO2 H specifically afforded amyloid-like nanofibers. These findings further allowed to achieve the fibrillation of a longer metal sequence containing three different metals (Fmoc-Rh-Pt-Re-Re-CO2 H). Cyclic voltammetry of the fibrillated Fmoc-Re-Re-CO2 H demonstrated that the redox activity of the metal complexes in the sequence is preserved in the nanofibrous forms.

An anionic π molecule can form an aggregate when a multi-interactivity is introduced, in sharp contrast to common anionic molecules that are generally difficult to stack on each other. We found that a multi-interactive ligand, 2,5,8-tri(4'-pyridyl)-1,3,4,6,7,9-hexaazaphenalenate (TPHAP- ) exhibited a large Stokes shift and an intramolecular charge transfer, both of which were sensitive to hydrogen-bonding media. An anionic potassium salt of TPHAP- in methanol formed various aggregation states depending on the concentration examined; this was revealed by steady-state spectroscopic and fluorescence lifetime measurements. Self-assembling cadmium ions and the ligands can create several morphological crystals that are controlled by the ligand concentration, among which three new structures were determined by single-crystal analysis. The X-ray structures obtained suggest that the aggregation states of the ligand in solution can be transferred to the solid system of the porous coordination networks.

Formation of coordination networks is a complex process affected by a multitude of factors. Many synthetic strategies have been developed that attempt to control these factors and direct the structure of the final product. Coordination bond formation and structural assembly processes, however, typically take place either in the solution or solid states. In comparison, gas-phase network synthesis remains largely unexplored. Herein, two new two-dimensional coordination networks are obtained from the solid-gas phase reaction between ZnX2 (X=I, Br) and the redox-active 2,5,8-tri(4-pyridyl)1,3-diazaphenalene (HTPDAP) ligand. Their structures were solved by ab initio powder X-ray diffraction analysis and feature a novel Zn halide trimeric cluster. This strategy is contrasted with a conventional solvothermal synthesis, which led to a one-dimensional coordination polymer instead. The intrinsic electroactive properties of these materials were probed by solid-state cyclic voltammetry measurements, which revealed the presence of HTPDAP and halide-based processes. Chemical oxidation of the two-dimensional networks by using NOPF6 agent, unexpectedly, led to the formation of a nitrated analog of HTPDAP, the PF6- salt of diprotonated 4,6,7,9-tetranitro-2,5,8-tris(4-pyridyl)diazaphenalene cation (denoted N-TPDAP), which was isolated and characterized. These results provide deeper insights into the oxidation process of HTPDAP-containing networks and uncover unique redox-induced chemical transformations.

The amorphous state plays a key role in porous coordination polymer and metal-organic framework phase transitions. We investigate a crystalline-to-amorphous-to-amorphous-to-crystalline (CAAC) phase transition in a Zn based coordination polymer, by X-ray absorption fine structure (XAFS) and X-ray pair distribution function (PDF) analysis. We show that the system shows two distinct amorphous phases upon heating. The first involves a reversible transition to a desolvated form of the original network, followed by an irreversible transition to an intermediate phase which has elongated Zn-I bonds.

A neutral mononuclear Fe(III) complex [Fe(III) (H-5-Br-thsa-Me)(5-Br-thsa-Me)]⋅H2 O (1; H2 -5-Br-thsa-Me=5-bromosalicylaldehyde methylthiosemicarbazone) was prepared that exhibited a three-step spin-crossover (SCO) with symmetry breaking and a 14 K hysteresis loop owing to strong cooperativity. Two ordered intermediate states of 1 were observed, 4HS-2LS and 2HS-4LS, which exhibited reentrant phase-transition behavior. This study provides a new platform for examining multistability in SCO complexes.