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Emissive push–pull‐type bisnaphthyridylamine derivatives (BNA‐X: X=Me, Et, Bzl, Ph, BuBr, and BuTEMPO) aggregate in aqueous methanol. Furthermore, a two‐step emission and aggregation process is controllable by varying the methanol‐to‐water ratio. At 2:3 MeOH/H2O, crystallization‐induced emission enhancement (CIEE) occurs via formation of an emissive crystal phase, whereas, at 1:9 MeOH/H2O, aggregation‐induced emission enhancement (AIEE) occurs, induced by emissive supramolecular nanoparticles (NPs). For BNA‐Ph, the emission quantum yield was 25 times higher in aqueous methanol than that in pure methanol. Despite the high hydrophobicity of BNA‐X (C log P=6.1–8.0), the spherical NPs were monodisperse (polydispersity indices <0.2). Moreover, the emissive NPs exhibited fluorescence resonance energy transfer (FRET) with pyrene; however, for BNA‐X bearing the TEMPO radical (BNA‐BuTEMPO), no FRET was observed because of quenching. In particular, the BNA‐BuTEMPO NPs have a slow rotational correlation time (1.3 ns), suggesting applications as magnetic resonance imaging contrast agents with large relaxivity. [ABSTRACT FROM AUTHOR]

The crystal structure of the dinuclear cobalt(II) complex composed of didiazo-pyridine ligand D2[py.sub.2](TBA) and Co[(hfpip).sub.2], bis(1,1,1,5,5,5-hexafluoro-4-(4-tert-butylphenylimino)-2-pentanonate)cobalt and its magnetic behavior after irradiation in a crystalline state is examined. The results have shown that the magnetic interactions between the anisotropic cobalt ion and the carbenes generated by photolysis produce the observed single-molecule magnets (SMMs) character.

In our bodies, a slight pH change causes remarkable activation or serious damage in the biological processes and continuously keeps biological homeostasis. Detection of such a slight pH change has been a constant demand in searching for unusual biological events. In this paper, we demonstrate a novel pH sensory system that has been achieved through a combination of charge neutralization by a slight pH change with aggregation-induced emission (AIE). We selected a cyano-functionalized oligo(phenylene-vinylene) (cyanoOPV) backbone for AIE and introduced ammonium-tethered boronic acid groups as a pH-dependent function. The self-assembling of these dyes ( OPV-Cn) was readily achieved by pH-dependent charge neutralization at the neutral pH region. This sensory system showed unusually sensitive pH responsiveness in a narrow pH range. Moreover, this pH change was observed in a biologically important neutral pH region. We therefore believe that this system is broadly applicable to detect the slight pH change occurring in the biological events. [ABSTRACT FROM AUTHOR]

The newly developed oligophenylenevinylene (OPV)-based fluorescent (FL) chiral chemosensor (OPV-Me) for the representative enantiomeric guest, 1,2-cyclohexanedicarboxylic acid (1,2-CHDA: RR- and SS-form) showed the high chiral discrimination ability, resulting in the different aggregation modes of OPV-Me self-assembly: RR-CHDA directed the fibrous supramolecular aggregate, whereas SS-CHDA directed the finite aggregate. The consequent FL intensity toward RR-CHDA was up to 30 times larger than that toward SS-CHDA. Accordingly, highly enantioselective recognition was achieved. Application to the chirality sensing was also possible: OPV-Me exhibited a linear relationship between the FL intensity and the enantiomeric excess through the morphological development of stereocomplex aggregates. These results clearly show that the chiral recognition ability is manifested by the amplification cascade of the chirality difference through self-assembly. [ABSTRACT FROM AUTHOR]

The control over supramolecular interactions and obtaining information beyond the molecular scale is an extended challenge. The intriguing self-assembly of a perylene-3,4,9,10-tetracarboxylic acid diimide (PDI)-based novel bolaamphiphilic probe is experienced within an artificial environment that is restrained by using supramolecular crystallization and molecular recognition. The bolaamphiphile with a hydrophilic [18]-azacrown ether ring produced nanoaggregates due to differing solubilities in organic and aqueous media. A structural evolution was observed in the presence of alkali metal ions as guests. The metal complexes form a pseudo-cationic structure, which is further involved in an ionic self-assembly with biomolecules, thus resulting new spectroscopic information on the dye self-assembly. The overarching aim of this study is to emphasize the importance of the concept of supramolecular adaptability, which has been used to establish an environment-friendly behavior based on noncovalent forces, thus leading to the evolution of new assembly structures and photophysical properties. [ABSTRACT FROM AUTHOR]

Long-term creative approaches have been considered in the design of molecular probes to overcome the quenching effect of important dyes in an aqueous medium. Using the rational donor–acceptor based design principle, we demonstrate herein the different fluorescence states of a non-conjugated symmetrical perylene-azacrown ether system in a solution, from the molecular to the aggregated states. The ethylene-spacer is exceptionally capable of fluorescence enhancement, even in the aggregated state (organic nanoparticle, ONPs, 44 nm), overcoming the quenching effect on changing the solvent from tetrahydrofuran to water. The ONPs with crown ether receptors at the surface show colloidal stability in an aqueous solution. Furthermore, an improved fluorescent state is developed via ONPs–polymer (protamine, Pro) hybridization. Supramolecular interactions between the crown ring and the guanidinium group in Pro play an important role in the ONPs–Pro hybrid formation. The decorated fluorescent hybrid state is finally used as a nano-probe for sensing heparin via the turn-OFF mechanism. The decoration method is further generalized by recognition of the nucleotides. Herein, we detail the bottom-up approach to the molecular design and development of the different fluorescent states of a useful probe. Most excitingly, this new approach is very general and adaptive to facile detection. [ABSTRACT FROM AUTHOR]

Oligophenylenevinylene (OPV)-based fluorescent (FL) chemosensors exhibiting linear FL responses toward polyanions were designed. Their application to FL sensing of glycosaminoglycans (heparin: HEP, chondroitin 4-sulfate: ChS, and hyaluronic acid: HA) revealed that the charge density encoded as the unit structure directs the mode of OPV self-assembly: H-type aggregate for HEP with 16-times FL increase and J-type aggregate for HA with 93-times FL increase, thus unexpectedly achieving the preferential selectivity for HA in contrast to the conventional HEP selective systems. We have found that the integral magnitude of three factors consisting of binding mechanism, self-assembly, and FL response can amplify the structural information on the target input into the characteristic FL output. This emergent property has been used for a novel molecular recognition system that realizes unconventional FL sensing of HA, potentially applicable to the clinical diagnosis of cancer-related diseases. [ABSTRACT FROM AUTHOR]

Recognition directed spontaneous assembly formation has been used to build-up a sensory system with perylene bis-guanidinium (PBG), which presented great response towards chiral guest sensing. Based on structural modification in the chiral guest molecules, PBG can selectively recognize dibenzoyl tartaric acid (DBTA) among the other tartaric acids (TA), resulting in an explicit read-out of molecular information via the generation of characteristic induced circular dichroism spectra for the d- and l-enantiomers. The binding ability depends only on the substituents in the TA and the local guidance plays an important role in structure formation. The bulky substituents in TA can lead to induced chirality in the cofacial perylene stacks by generating an active angle between the successive transition dipoles. The induced helical sense was found to exhibit efficient chiral amplification with a sigmoidal change (i.e. according to a sergeants-and-soldiers effect) in the enantiomeric excess plot. The diversity in physical properties was further examined by the preparative method. Compared to the simple mixing method, the heating–cooling method is able to show aggregation induced fluorescence enhancement, which was used to fabricate highly efficient fluorescent solid in a supramolecular manner from a perylene-based dye. [ABSTRACT FROM AUTHOR]

Although self-assembly has realized the spontaneous formation of nanoarchitectures, the nanoscopic expression of chemical structural information at the molecular level can alternatively be regarded as a tool to translate molecular structural information with high precision. We have found that a newly developed guanidinium-tethered oligophenyle-nevinylene exhibits characteristic fluorescence (FL) responses toward l- and meso-tartarate, wherein the different self-assembly modes, termed J- or H-type aggregation, are directed according to the molecular information encoded as the chemical structure. This morphological difference originates from the geometric anti versus gauche conformational difference between l- and meso-tartarate. A similar morphological difference can be reproduced with the geometric C=C bond difference between fumarate and maleate. In the present system, the dicarboxylate structural information is embodied in the inherent threshold concentration of the FL response, the signal-to-noise ratio, and the maximum FL wavelength. These results indicate that self-assembly is meticulous enough to sense subtle differences in molecular information and thus demonstrate the potential ability of self-assembly for the expression of a FL sensory system. [ABSTRACT FROM AUTHOR]

A novel tetraphenylethene-based fluorescence (FL) chemosensor exhibits nonlinear turn-on FL switching though cooperative binding of L-tartarate, where its convergent binding to form cyclic substructures is responsible for the FL increase. This binding scheme achieves selective detection of dicarboxylates over monocarboxylates, thus is potentially applicable to the preliminary screening for metabolic disorders. [ABSTRACT FROM AUTHOR]

Human autosomal recessive polycystic kidney disease (ARPKD) produces kidneys which are massively enlarged due to multiple cysts, hypertension, and congenital hepatic fibrosis characterized by dilated bile ducts and portal hypertension. The PCK rat is an orthologous model of human ARPKD with numerous fluid-filled cysts caused by stimulated cellular proliferation in the renal tubules and hepatic bile duct epithelia, with interstitial fibrosis developed in the liver. We previously reported that a peroxisome proliferator activated receptor (PPAR)-γ full agonist ameliorated kidney and liver disease in PCK rats. Telmisartan is an angiotensin receptor blocker (ARB) used widely as an antihypertensive drug and shows partial PPAR-γ agonist activity. It also has nephroprotective activity in diabetes and renal injury and prevents the effects of drug-induced hepatotoxicity and hepatic fibrosis. In the present study, we determined whether telmisartan ameliorates progression of polycystic kidney and fibrocystic liver disease in PCK rats. Five male and 5 female PCK and normal control (+/+) rats were orally administered 3 mg/kg telmisartan or vehicle every day from 4 to 20 weeks of age. Treatment with telmisartan decreased blood pressure in both PCK and +/+ rats. Blood levels of aspartate amino transferase, alanine amino transferase and urea nitrogen were unaffected by telmisartan treatment. There was no effect on kidney disease progression, but liver weight relative to body weight, liver cystic area, hepatic fibrosis index, expression levels of Ki67 and TGF-β, and the number of Ki67- and TGF-β-positive interstitial cells in the liver were significantly decreased in telmisartan-treated PCK rats. Therefore, telmisartan ameliorates congenital hepatic fibrosis in ARPKD, possibly through the inhibition of signaling cascades responsible for cellular proliferation and interstitial fibrosis in PCK rats. The present results support the potential therapeutic use of ARBs for the treatment of fibrocystic liver disease in ARPKD patients. [ABSTRACT FROM AUTHOR]

Hold and connect! Inclusion of a bridging ligand into cyclodextrin (CD), followed by the addition of TbIII leads to a polyrotaxane‐type metallosupramolecular polymer (see figure, L=4,4′‐biphenyldicarboxylic acid). This polymer can recognize chirality and differentiate enantiomers by fluorescence and circular dichroism spectral changes. [ABSTRACT FROM AUTHOR]

We demonstrate a new method for the preparation of silver nanoparticles (AgNPs) utilising dye-sensitised photo-reduction on triple-stranded β-1,3-glucans. Reflecting the chiral helical structure of these polysaccharides, the chiral plasmonic AgNPs were yielded when hydrophobic dyes strongly interacting with the helical β-1,3-glucan main-chain were used. This system offers a new strategy to create chiral plasmonic AgNPs and a new idea to utilise helix-forming polysaccharides as a chiral template. [ABSTRACT FROM AUTHOR]

A fluorescent sensor based on guanidinium-tethered tetraphenylethene (TPE) has been investigated toward the differentiation of pyridine nucleotide cofactors (NAD+, NADH, NADP+, and NADPH). TPE selectively recognizes NADPH possessing the higher tetra-anionic net-charge, resulting in the steep 'turn-on' fluorescence increase. The comparative aggregation behaviors and fluorescence response studies of TPE on the four cofactors reveal that the critical aggregate concentration of TPE against NADPH correlates directly with the concentration threshold for the fluorescence response. These results establish that TPE can selectively differentiate NADPH over the other three cofactors by the steep aggregation-induced fluorescence response accompanied by the high signal-to-background contrast. [ABSTRACT FROM AUTHOR]

Kidneys are enlarged by aberrant proliferation of tubule epithelial cells leading to the formation of numerous cysts, nephron loss, and interstitial fibrosis in polycystic kidney disease (PKD). Pioglitazone (PIO), a PPAR-γ agonist, decreased cell proliferation, interstitial fibrosis, and inflammation, and ameliorated PKD progression in PCK rats (Am. J. Physiol.-Renal, 2011). To explore genetic mechanisms involved, changes in global gene expression were analyzed. By Gene Set Enrichment Analysis of 30655 genes, 13 of the top 20 downregulated gene ontology biological process gene sets and six of the top 20 curated gene set canonical pathways identified to be downregulated by PIOtreatment were related to cell cycle and proliferation, including EGF, PDGF and JNK pathways. Their relevant pathways were identified using the Kyoto Encyclopedia of Gene and Genomes database. Stearoylcoenzyme A desaturase 1 is a key enzyme in fatty acid metabolism found in the top 5 genes downregulated by PIO treatment. Immunohistochemical analysis revealed that the gene product of this enzyme was highly expressed in PCK kidneys and decreased by PIO. These data show that PIO alters the expression of genes involved in cell cycle progression, cell proliferation, and fatty acid metabolism. [ABSTRACT FROM AUTHOR]

In autosomal recessive polycystic kidney disease (ARPKD), progressive enlargement of fluid-filled cysts is due to aberrant proliferation of tubule epithelial cells and transepithelial fluid secretion leading to extensive nephron loss and interstitial fibrosis. Congenital hepatic fibrosis associated with biliary cysts/dilatations is the most common extrarenal manifestation in ARPKD and can lead to massive liver enlargement. Peroxisome proliferator-activated receptor γ (PPAR-γ), a member of the ligand-dependent nuclear receptor superfamily, is expressed in a variety of tissues, including the kidneys and liver, and plays important roles in cell proliferation, fibrosis, and inflammation. In the current study, we determined that pioglitazone (PIO), a PPAR-γ agonist, decreases polycystic kidney and liver disease progression in the polycystic kidney rat, an orthologous model of human ARPKD. Daily treatment with 10 mg/kg PIO for 16 wk decreased kidney weight (% of body weight), renal cystic area, serum urea nitrogen, and the number of Ki67-, pERK1/2-, and pS6-positive cells in the kidney. There was also a decrease in liver weight (% of body weight), liver cystic area, fibrotic index, and the number of Ki67-, pERK1/2-, pERK5-, and TGF-β-positive cells in the liver. Taken together, these data suggest that PIO inhibits the progression of polycystic kidney and liver disease in a model of human ARPKD by inhibiting cell proliferation and fibrosis. These findings suggest that PPAR-γ agonists may have therapeutic value in the treatment of the renal and hepatic manifestations of ARPKD. [ABSTRACT FROM AUTHOR]

Han:SPRD Cy is a spontaneous rat model of polycystic kidney disease (PKD) caused by a missense mutation in Pkdr1. Cystogenesis in this model is not clearly understood. In the current study, we performed global gene expression profiling in early-stage PKD cyst development in Cy/Cy kidneys and normal (+/+) kidneys at 3 and 7 days of postnatal age. Expression profiles were determined by microarray analysis, followed by validation with real-time RT-PCR. Genes were selected with over 1.5-fold expression changes compared with age-matched +/+ kidneys for canonical pathway analysis. We found nine pathways in common between 3- and 7-day Cy/Cy kidneys. Three significantly changed pathways were designated "Vitamin D Receptor (VDR)/Retinoid X Receptor (RXR) Activation," "LPS/IL-1-Mediated Inhibition of RXR Function," and "Liver X Receptor (LXR)/RXR Activation." These results suggest that RXR-mediated signaling is significantly altered in developing kidneys with mutated Pkdr1. In gene ontology analysis, the functions of these RXR-related genes were found to be involved in regulating cell proliferation and organ morphogenesis. With real-time RT-PCR analysis, the upregulation of Ptx2, Alox15b, OSP, and PCNA, major markers of cell proliferation associated with the RXR pathway, were confirmed in 3- and 7-day Cy/Cy kidneys compared with 3-day +/+ kidneys. The increased RXR protein was observed in both the nucleus and cytoplasm of cystic epithelial cells in early-stage Cy/Cy kidneys, and the RXR-positive cells were strongly positive for PCNA staining. Taken together, cell proliferation and organ morphogenesis signals transduced by RXR-mediated pathways may have important roles for cystogenesis in early-stage PKD in this Pkdr1-mutated Cy rat. [ABSTRACT FROM AUTHOR]

An original reduced elementary reaction scheme for a gas mixture including the components of natural gas and gas oil has been constructed. Also, the combustion process in a supercharged dual-fuel engine, in which a mixture of natural gas and air was fed from an intake port and a small amount of gas oil was injected as an ignition source, has been computed three-dimensionally with consideration for chemical kinetics and with the authors' GTT code linked to CHEMKIN-II subroutines. The validity of the proposed chemical kinetic model has been confirmed by comparing the calculated results with experimental results. [ABSTRACT FROM AUTHOR]

The vector control method is widely used for induction motor drives. In these applications, a rotational transducer such as a shaft encoder is used. A rotational transducer, however, cannot be mounted in some cases, such as motor drives in a hostile environment or high-speed motor drives. Several sensorless vector-controlled induction machine drive methods have been proposed. These methods have the disadvantage that rotor resistance variation causes errors in the estimation of the motor speed. It is difficult to estimate the motor speed and the rotor resistance simultaneously, because the equivalent rotor resistance is the ratio of the rotor resistance to the slip at steady state. Therefore, we have proposed a method of simultaneously estimating the motor speed and the rotor resistance of an induction motor by superimposing ac components on the field current command. This paper presents a modified method of the rotor resistance adaptation. The validity of the proposed method is verified by experiments. © 1998 Scripta Technica, Electr Eng Jpn, 125(2): 65–72, 1998 [ABSTRACT FROM AUTHOR]

Cover Feature: Push-Pull Bisnaphthyridylamine Supramolecular Nanoparticles: Polarity-Induced Aggregation and Crystallization-Induced Emission Enhancement and Fluorescence Resonance Energy Transfer (Chem. Eur. J. 9/2021) Keywords: emission; fluorescence; FRET; nanoparticles; radicals EN emission fluorescence FRET nanoparticles radicals 2885 2885 1 02/12/21 20210210 NES 210210 B An organic solution with a push-pull-type fluorophore b , which resembles the shape of a dragon in the cover image, exhibits aggregation-induced emission enhancement upon water addition. Emission, fluorescence, FRET, nanoparticles, radicals. [Extracted from the article]

Molecular Recognition Synergistic marriage of self‐assembly and fluorescence (FL) signaling has realized fluorometric readout of dicarboxylates. A newly developed guanidinium‐tethered oligophenylenevinylene (OPV‐G) exhibits characteristic self‐assembling behaviors toward L‐ and meso‐tartarate. Therein, the different self‐assembly modes termed J‐ and H‐type are directed to afford fibrous and finite aggregates, respectively. Such a difference derived from the inherent tartarate structures is eventually embodied as the unique FL responses. For more details, see the Full Paper by T. Noguchi, S. Shinkai et al. on page 13938 ff. [ABSTRACT FROM AUTHOR]

Renal cyclooxygenase (COX) derived eicosanoids are elevated and lipoxygenase (LOX) products are reduced in the Han:SPRD- Cy rat model of polycystic kidney disease (PKD). Selective COX2 inhibition reduces kidney disease progression, but COX1 levels also are elevated in this model. Since the effect of reducing the products of both COX isoforms and the role of LOX products is not known, weanling normal and diseased Han:SPRD- cy littermates were given either low dose acetylsalicylic acid (ASA), nordihydroguaiaretic (NDGA) or no treatment for eight weeks. Renal eicosanoids were altered in the diseased compared to normal cortex, with COX products being higher and LOX products being lower. ASA reduced COX products, cyst growth and kidney water content, while NDGA reduced LOX products without altering disease progression or kidney function. Hence, a human equivalent ASA dose equal to less than one regular strength aspirin per day slowed disease progression, while further reduction of LOX products did not worsen disease progression. [ABSTRACT FROM AUTHOR]