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Since drug carriers are envisaged to be used in a wide variety of situations and environments, nanocarriers with diverse properties, such as biocompatibility, biodegradability, nonimmunogenicity, adequate particle size, robustness, and cell permeability, are required. Here, we report the construction of novel nanocapsules with the above-mentioned features by the self-assembly of peptides composed of oligoproline and oligoleucine (i.e., H-Pro 10 Leu 4 -NH 2 and H-Pro 10 Leu 6 -NH 2 ). The peptides self-organized via hydrogen bonds and hydrophobic interactions between oligoleucine moieties to form vesicle-like nanocapsules with cationic oligoproline exposed on the surface. The guest encapsulation experiments revealed that the nanocapsules were capable of uptake of both water-soluble and insoluble compounds. Furthermore, positively charged and/or oligoproline-based peptides are known to improve cell permeability and cellular uptake, suggesting that the peptide nanocapsules are good candidates for nanocarriers to complement liposomes and polymer micelles.

The introduction of novel materials with multifunctional chromogenic properties, such as electrochromic/electrofluorochromic (EC/EFC) properties, has recently attracted prospective interest in the development of various optoelectronic devices and smart windows. In this study, a novel Zn(II)-based metallo-supramolecular polymer ( polyZn ) has been developed as an ON/OFF switchable EFC application with prominent EC behavior. In this regard, the polymeric chain of polyZn was first synthesized by 1:1 complexation in a zigzag manner with Zn(II) ions at the metal center and 4,4'-[bis(2,2':6',2″-terpyridinyl)benzene]triphenylamine ( L TPY-TPA ) as the redox-active ditopic ligand. The polyZn exhibits excellent solubility in organic solvents and can form a very good uniform thin film on an indium tin oxide/glass substrate by spin-coating. In a neutral state, transparent polyZn exhibits a bright yellow color to the naked eye (absorption at ∼325 nm). The electroactive triphenylamine (TPA) core of L TPA-TPY , however, undergoes reversible single-electron oxidation when a positive bias of +1.6 V vs Ag/Ag + is applied, generating radical cations (TPA ↔ TPA •+ ) with a significant drop in transparency (77%). A noticeable chromic shift in the hue of the film from brilliant yellow to green was observed with the appearance of a near-infrared absorption band at ∼897 nm with a tail of 1300-1600 nm. Interestingly, in addition to this EC phenomenon, the fabricated solid-state polyZn film exhibits intense, high-contrast reddish-orange photoluminescence with λ em = 650 nm, which is significantly desired as a molecular probe for bioimaging. Both the TPA core and the redox-inactive Zn(II)-terpyridine core emit orange-red photoluminescence in polyZn , which is significantly quenched upon the oxidation of the film and is re-emitted at 0.0 V vs Ag/Ag + . This ON/OFF EFC transition was sustained for several cycles. This study should motivate to design and create distinctive new unique materials with combined EC/EFC behavior for the fabrication of optoelectronic devices by combining a metal-fluorescent core with a redox-active spacer.

Porous liquids (PLs) are attractive materials because of their capability to combine the intrinsic porosity of microporous solids and the processability of liquids. Most of the studies focus on the synthesis of PLs with not only high porosity but also low viscosity by considering their transportation in industrial plants. However, a gap exists between PLs and solid adsorbents for some practical cases, where the liquid characteristics and mechanical stability without leakage are simultaneously required. Here, we fill in this gap by demonstrating a new concept of pore-networked gels, in which the solvent phase is trapped by molecular networks with accessible porosity. To achieve this, we fabricate a linked metal-organic polyhedra (MOPs) gel, followed by exchanging the solvent phase with a bulky liquid such as ionic liquids (ILs); the dimethylformamide solvent trapped inside the as-synthesized gel is replaced by the target IL, 1-butyl-3-methylimidazolium tetrafluoroborate, which in turn cannot enter MOP pores due to their larger molecular size. The remaining volatile solvents in the MOP cavities can then be removed by thermal activation, endowing the obtained IL gel ( Gel_IL ) with accessible microporosity. The CO 2 capacities of the gels are greatly enhanced compared to the neat IL. The exchange with the IL also exerts a positive influence on the final gel performances such as mechanical properties and low volatility. Besides ILs, various functional liquids are shown to be amenable to this strategy to fabricate pore-networked gels with accessible porosity, demonstrating their potential use in the field of gas adsorption or separation.

We report the near-infrared (NIR) photoluminescence of single-wall carbon nanotubes (SWCNTs) generated by chemical energy derived from enzymatic reactions. NIR photoluminescence from SWCNTs has attracted much attention for medical applications, such as bioimaging and biosensors, because of its high transparency and low scattering in biological tissues; however, visible excitation light cannot reach deep tissues. We developed a novel method in which the NIR luminescence of SWCNTs is powered by the biochemical reaction of luciferin/luciferase from fireflies. The luminescence could be detected by a highly sensitive measurement system using an infrared camera, and the optimal conditions for luminescence were investigated. Spectroscopic analysis of the NIR luminescence using chirality-sorted SWCNTs confirmed that the luminescence was derived from SWCNTs. This is the first report achieving NIR photoluminescence of SWCNTs using chemical energy, which does not require external energies, e.g., excitation light or electronic power, and will be applicable to biological imaging and sensing.

Cage-like supramolecular assemblies called molecular cages, which possess attractive functions, have been prepared. Although biomolecule-based nanocages are required for biological/medical applications such as drug delivery systems, the majority of nanocages are constructed using aromatic compounds with lower biocompatibility and biodegradability. In this study, the construction of a peptide nanocage consisting of an oligoproline conjugate is demonstrated. The conjugate was easy to prepare and had high biocompatibility. The oligoproline moiety of the conjugate had a rigid, rod-like structure suitable for the backbone of the supramolecular nanocage. The conjugates self-assembled to form peptide nanocages with a huge inner cavity.

The present study reports a surprising protein-condensing effect of glucose, prompted by our accidental observation during chemical library screening under a high-glucose condition. We noticed "glucosing-out" of certain compounds, in which physiological concentrations of glucose induced compound aggregation. Adapting the "glucosing-out" concept to proteins, our proteomic analysis identified three cellular proteins (calmodulin, rho guanine nucleotide exchange factor 40, and polyubiquitin-C) that displayed robust glucose-dependent precipitation. One of these proteins, calmodulin, formed glucose-dependent condensates that control cellular glycogenolysis in hepatic cells. Our findings suggest that glucose is a heretofore underappreciated driver of protein phase separation that may have profound effects on cellular homeostasis.

Low-voltage operation, high durability, and long memory time are demanded for electrochromic (EC) display device applications. Metallo-supramolecular polymers (MSPs), composed of a metal ion and ditopic ligand, are one of the recently developed EC materials, and the ligand modification is expected to tune the redox potential of MSP. In order to lower the redox potential of MSP, tetrakis( N -methylbenzimidazolyl)bipyridine ( L Bip ) was designed as an electronically rich ligand. Ru-based MSP ( polyRu-L Bip ) was successfully synthesized by 1:1 complexation of RuCl 2 (DMSO) 4 with L Bip . The molecular weight ( M w ) was high (8.8 × 10 6 Da) enough to provide a simple 1 H NMR spectrum, of which the proton peaks could be assigned by the comparison with the spectrum of the corresponding mono-Ru complex. The redox potential ( E 1/2 ) between Ru(II/III) was 0.51 V versus Ag/Ag + , which was much lower than the redox potential of previously reported Ru-based MSP with bis(terpyridyl)benzene (0.95 V vs Ag/Ag + ). The polymer film exhibited reversible, distinct color changes between violet and light green-yellow upon applying very low potentials of 0 and 0.6 V vs Ag/Ag + , respectively. The appearance and disappearance of the metal-to-ligand charge transfer absorption by the electrochemical redox between Ru(II/III) were confirmed using in situ spectro-electrochemical measurement. A solid-state EC device with polyRu-L Bip was revealed to have large optical contrast (Δ T 54%), fast response time (1.37 s for bleaching and 0.67 s for coloration), remarkable coloration efficiency (571 cm 2 /C), and high durability for the repeated color changes more than 20,000 cycles. The device also showed a long optical memory time of up to 19 h to maintain 40% to the initial contrast under the open circuit conditions. It is considered that the stabilization of the Ru(III) state by L Bip suppressed the self-coloring to Ru(II) inside the device.

Dual-redox metallo-supramolecular polymers with a zigzag structure ( polyFe-N and polyRu-N ) were successfully synthesized by 1:1 complexation of a redox-active Fe(II) or Ru(II) ion and 4,4-bis(2,2:6,2-terpyridinyl)phenyl-triphenylamine ( L TPA ) as a redox-active ligand. The polymers had high solubility in methanol, and the polymer solutions showed dark brown ( polyFe-N ) or orange-red ( polyRu-N ) coloration. UV-vis spectra of the polymers displayed a strong metal-to-ligand charge transfer (MLCT) absorption in the visible region. Cyclic voltammograms of the polymer films exhibited two pairs of reversible redox waves. The first redox at ∼0.5 V versus Ag/Ag + was assigned to the redox in the triphenylamine (TPA) moiety of L TPA , and the second redox at 0.8 V versus Ag/Ag + ( polyFe-N ) or 0.9 V versus Ag/Ag + ( polyRu-N ) was given to the redox of Fe(II)/(III) or Ru(II)/(III), respectively. Upon applying a positive potential of more than 0.5 V versus Ag/Ag + to the polymer films, a new absorption at ∼820 nm in the near-infrared (NIR) region appeared with wide tailing to the longer wavelength. It is considered that the new absorption in the NIR region is caused by the polaron band of the oxidized ligand in the polymers. When the applied potential was increased to 1.0 V versus Ag/Ag + ( polyFe-N ) or 1.1 V versus Ag/Ag + ( polyRu-N ), the maximum wavelength of the new absorption in the NIR region shifted to 885-900 nm and the absorbance was further enhanced with disappearance of the MLCT absorption. Eventually, the original colors of the polymers were faint to light green. This visible-to-NIR electrochromism was reversible, and maximum optical contrast (Δ T ) reached 52% in the visible region and 80% in the NIR region. A prototype solid-state device with the polymer was fabricated for practical utilization, exhibiting excellent cycle stability of >4000 cycles with maintaining high optical contrast from the visible-to-NIR range.

Highly dense hexagonal Fe(II)-based coordination nanosheets (CONASHs) were designed by dual-branching, at the metal-coordination moieties and the tritopic ligands, which successfully obtained a liquid/liquid interface by the complexation of Fe(II) ions and the tritopic bidentate ligands. The 1:1 complexation was confirmed by titration. The obtained Fe(II)-based nanosheets were fully characterized by small-angle X-ray scattering (SAXS), atomic force microscopy (AFM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). A monolayer of the sheets was obtained, employing the Langmuir-Blodgett (LB) method, and the determined thickness was ∼2.5 nm. The polymer nanosheets exhibited red-to-colorless electrochromism because the electrochemical redox transformation between Fe(II) and Fe (III) ions controlled the appearance/disappearance of the metal (ion)-to-ligand charge-transfer (MLCT) absorption. The poor π-conjugation in the tritopic ligands contributed to the highly colorless electrochromic state. A solid-state device, with the robust polymer film, exhibited excellent electrochromic (EC) properties, with high optical contrast (Δ T > 65%) and high durability after repeated color changes for >15 000 cycles, upon applying low-operating voltages (+1.5/0 V).

The Ni(II)-based metallosupramolecular polymer with carboxylic acid groups ( polyNi ) was synthesized via a 1:1 complexation of Ni(II) salt with (4,4'-(9,9-dihexyl-9H-fluorene-2,7-diyl)bis(pyridine-2,6-dicarboxylic acid) for the first time. The divalent state of Ni(II) in the polymer was confirmed by the X-ray absorption fine structure analysis. Smooth loading of imidazole molecules into polyNi proceeded with the help of the carboxylic acid groups to form the imidazole-loaded polyNi ( polyNi-Im ). Thermogravimetric analysis of polyNi-Im revealed that approximately three imidazole molecules were incorporated per repeating unit of polyNi . The Fourier transform infrared spectrum of polyNi-Im showed a new peak at 3219 cm -1 , which shows an ∼73 cm -1 enhancement to -N-H of pristine imidazole. The peak suggests the formation of an imidazolium cation in the polymer. Powder X-ray diffraction indicated no degradation of the polymer structure during the imidazole loading because the diffraction pattern of polyNi-Im was almost the same as that of polyNi except for the presence of peaks corresponding to the imidazole molecules. Interestingly, the scanning electron microscopy measurement showed a large morphological change to uniform spherical particles by loading imidazole to the polymer. PolyNi-Im exhibited good proton conductivity (1.05 × 10 -2 mS/cm) at a high temperature (120 °C), which is around 7 orders of magnitude higher than that of pristine polyNi because of the proton conduction pathway formation along the polymer chains by the incorporated imidazole molecules., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

The use of metallo-supramolecular polymer (MSP) as a thin-film-based redox supercapacitor electrode material is reported for the first time. Fe(II)- and Ru(II)-based MSPs (polyFe and polyRu, respectively) were synthesized by complexation of appropriate metal salts with 4',4″-(1,4-phenylene)bis-2,2':6',2″-terpyridine, and thin films of these polymers were prepared by spray coating onto an indium tin oxide glass substrate. A study of the energy storage performances of the polyFe and polyRu films in a nonaqueous electrolyte system revealed volumetric capacitances of ∼62.6 ± 3 F/cm 3 for polyFe and 98.5 ± 7 F/cm 3 for polyRu at a current density of 2 A/cm 3 . To improve the energy storage performance over a wider potential range, asymmetric supercapacitor (ASC) displays were fabricated with suitable combinations of the MSPs as cathodic materials and Prussian blue as the anodic counter material in a sandwich configuration with a transparent polymeric ion gel as the electrolyte. The fabricated ASCs showed a maximum volumetric energy density (∼10-18 mW h/cm 3 ) that was higher than that of lithium thin-film batteries and a power density (7 W/cm 3 ) comparable to that of conventional electrolyte capacitors, with superb cyclic stability for 10 000 cycles. To demonstrate the practical use of the MSP, the illumination of a light-emitting diode bulb was powered by a laboratory-made device. This work should inspire the development of high-performance thin-film flexible supercapacitors based on MSPs as active cathodic materials.

Metallo-supramolecular polymer (MSP)-based electrochromic devices (ECDs) have drawn much attention because of their variable colors and attractive electrochromic (EC) properties. However, fabrication of voltage-tunable multicolor ECDs using single MSP is yet hard to realize. We anticipated alternate introduction of two different redox-active metal ions in an MSP combined with the adjustment of counteranions could be a solution to fabricate multicolor ECDs. The heterometals will induce color variability upon voltage alteration, and counteranions will help to tune the solubility of MSP in different solvents. In an attempt to fulfill this target, we have synthesized four heterobimetallic supramolecular polymers (HBPs) having different counteranions (BF 4 - , Cl - , PF 6 - , and OAc - ), in which Fe(II) and Os(II) are alternately complexed by two terpyridine units. To apply as EC material, the HBPs should be soluble in methanol and insoluble in acetonitrile for the preparation of EC film as well as ECDs. However, among the HBPs, only HBP-OAc is found to meet this requirement. The EC behaviors of the spray-coating film of HBP-OAc on an indium tin oxide (ITO)-coated glass substrate are investigated in terms of maximum transmittance contrast, coloration voltage, response time, coloration efficiency, and operational stability, which exhibits reversible multicolor electrochromism (the initial purple color of the film is changed to violet followed by greenish-yellow) upon alteration of the voltage from 0.0 to 0.7 V [required to oxidize the Os(II) ion] and to 1.0 V [required to oxidize the Fe(II) ion]. The film is also integrated into a laminated ECD by using lithium-based gel electrolyte. Finally, as a proof-of-concept, a prototype voltage-tunable multicolor EC display (6 cm × 2.5 cm) is fabricated by using a designed image containing a flower, leaves, and a flower pot, which exhibits six different types of multicolor image upon application of tunable voltages.

Cationic copolymerization of different types of monomers, 4-hydroxybutyl vinyl ether (HBVE) and ε-caprolactone (CL), was explored using EtSO 3 H as an acid catalyst, producing copolymers with a remarkably wide variety of compositions and sequences. In the initial stage of the reaction, HBVE was unexpectedly isomerized to 2-methyl-1,3-dioxepane (MDOP), followed by concurrent copolymerization of MDOP and CL via active chain end and activated monomer mechanisms, respectively. The compositions and sequences of the copolymers were tunable, depending on the initial monomer concentrations. Moreover, a unique method was developed for transforming a copolymer with no CL homosequences into an "alternating" copolymer by removing MDOP from the system using a vacuum pump. This was achieved by the tandem reactions of depolymerization (unzipping) and random transacetalization (scrambling) under thermodynamic control. Specifically, the unzipping of HBVE homosequences proceeded at the oxonium chain end until a nondissociable ester bond emerged next to the chain end, while the scrambling of the main chain via transacetalization transferred midchain HBVE homosequences into the polymer chain end.

Perovskite-type oxynitride BaTaO 2 N has been attracting attention for its large dielectric constant, which is almost independent of the temperature by measurements on its ceramics. Its dielectric characteristics are attributed to polar nanoregions (PNRs) in the average cubic crystal structure. Polarization saturation to produce a butterfly-like piezoresponse force microscopy (PFM) signal was observed on BaTaO 2 N crystals in the present study. Reddish crystallites of BaTaO 2 N of up to 3.1 μm in size were grown using a BaCN 2 flux. Grain growth proceeded through the formation of a Ruddlesden-Popper-type oxynitride from the reaction between BaTaO 2 N powder and molten BaCN 2 . Their electrical property was studied using PFM with special care because of the small size of the crystals. They were found to be much more highly insulating than its ceramics. Ferroelectricity with complete phase inversion was observed on an oxynitride perovskite crystal for the first time. A large coercivity of 50-60 V was observed in the measurement. Such ferroelectricity is ascribed to the PNRs induced by the polar linkages between cis -type TaO 4 N 2 octahedra.

The coordination nanosheets (CONASHs) are emerging as a new class of functional two-dimensional materials, which are one of the most active research areas of chemistry and physics in this decade. Despite the success of various structural and functional CONASHs, the development of a new molecular structure to discover alluring functional CONASHs remains challenging. Herein, we report successful preparation of two novel CONASHs (NBP1 and NBP2) through coordination between one of the unexplored molecular frameworks of bis(2,2'-bipyridine)-based ligands (BP1 and BP2) and Fe 2+ ions. Using a liquid-liquid interface as a platform, large-scale thin films of multilayer CONASHs have been prepared without any support, which can be deposited onto any desired substrate. Detailed characterization of the CONASHs using various microscopic and spectroscopic techniques reveals homogeneous and flat morphology of nanometer thickness with the quantitative formation of tris(2,2'-bipyridine)-Fe 2+ complex motifs in the nanosheet frameworks. The color of the films has been tuned from blue to magenta by the suitable molecular design of the ligands. Owing to the insolubility of the CONASH films in any solvent and the presence of redox-active Fe 2+ , we explore the functionality of these nanostructured thin films deposited on indium tin oxide as electrochromic materials. The CONASHs exhibit color-to-colorless and color-to-color electrochromic transitions with attractive response times, switching stabilities, and coloration efficiencies. Finally, we demonstrate solid-state electrochromic devices of the CONASHs operated at a potential range of +2.5 to -2.5 V, which are electrochemically stable for several switching cycles, suggesting that these CONASHs are potential electrochromic materials for next-generation display applications.

Monoacylglycerol lipase (MAGL) is a cytosolic serine hydrolase involved in endocannabinoid and inflammatory signaling. Positron-emission tomography (PET) imaging of MAGL serves to validate target engagement of therapeutic MAGL inhibitors as well as to investigate MAGL levels under normal and disease conditions. However, PET radioligands with reversible binding kinetics for MAGL, which allow quantitative assessment of MAGL, are hitherto unavailable. In this study, we designed and synthesized fluoro-containing PET probes starting from a recently identified piperazinyl pyrrolidine-2-one derivative with reversible binding to MAGL. By tailoring the lipophilicity of the molecule to optimize nonspecific binding and blood-brain barrier permeability, we successfully identified two compounds that show high uptake to regions enriched with MAGL. PET imaging of wild-type and MAGL-deficient mice as well as a macaque monkey indicated that [ 18 F]5 ((4 R)-1-{3-[2-( 18 F)fluoro-4-methylpyridin-3-yl]phenyl}-4-[4-(1,3-thiazol-2-ylcarbonyl)piperazin-1-yl]pyrrolidin-2-one, [ 18 F]T-401) specifically binds to MAGL with adequate reversibility, yielding a high contrast for MAGL within an appropriate imaging time.

We demonstrate a new de novo synthetic methodology to achieve high-temperature-stable compelled composite superhydrophobic porous coordination polymers (PCPs). These new PCPs were achieved based on coordination capabilities of first-row transition metal ions such as Co 2+ , Ni 2+ , and Zn 2+ . The obtained composite PCPs containing a [Zn 2 M 2 O] 6+ (M = Co or Ni) bimetallic cluster core with open metal sites (OMSs) exhibited distinct isosteric heats of adsorption and surface areas due to the difference in their open metal Lewis acidic sites of solvent-free state. Additionally, these composite PCPs exhibit remarkable superhydrophobic properties with contact angles of 159.3° and 160.8° respectively for Zn-Co and Zn-Ni analogues. This superhydrophobic surface survives even at high temperature for longer time periods. As projected, these new composite PCPs exhibit better surface area and heats of adsorption compared to the PESD-1 (Zn) analogue due to a larger number of OMSs. Moreover, they display selective adsorption toward aromatic solvents such as benzene and toluene over aliphatic solvents such as cyclohexane due to corrugated and terminated aromatic hydrocarbon moieties toward the interactive surface. They also exhibit oil spill cleanup from the water surface in the powder form as well as pellet form up to 385 wt %. This study certainly offers a roadmap for designing and engineering new composite superhydrophobic porous materials for better water and thermal stability along with OMSs. This type of PCP exhibits a wide range of applications especially in catalysis, separation technology, and securing environmental problems such as oil spill cleanup in seawater.

No study has evaluated the mutagenicity of atmospheres with a calculated air quality health index (AQHI). Thus, we generated in a UV-light-containing reaction chamber two simulated atmospheres (SAs) with similar AQHIs but different proportions of criteria pollutants and evaluated them for mutagenicity in three Salmonella strains at the air-agar interface. We continuously injected into the chamber gasoline, nitric oxide, and ammonium sulfate, as well as either α-pinene to produce SA-PM, which had a high concentration of particulate matter (PM): 119 ppb ozone (O 3 ), 321 ppb NO 2 , and 1007 μg/m 3 PM 2.5 ; or isoprene to produce SA-O 3 , which had a high ozone (O 3 ) concentration: 415 ppb O 3 , 633 ppb NO 2 , and 55 μg/m 3 PM 2.5 . Neither PM 2.5 extracts, NO 2 , or O 3 alone, nor nonphoto-oxidized mixtures were mutagenic or cytotoxic. Both photo-oxidized atmospheres were largely direct-acting base-substitution mutagens with similar mutagenic potencies in TA100 and TA104. The mutagenic potencies [(revertants/h)/(mgC/m 3 )] of SA-PM (4.3 ± 0.4) and SA-O 3 (9.5 ± 1.3) in TA100 were significantly different ( P < 0.0001), but the mutation spectra were not ( P = 0.16), being ∼54% C → T and ∼46% C → A. Thus, the AQHI may have some predictive value for the mutagenicity of the gas phase of air.

A chemically inert, insulating layered silicate (saponite; SP) and an iron(II)-based metallo-supramolecular complex polymer (polyFe) were combined via electrostatic attraction to improve the electrochromic properties of polyFe. Structural characterization indicated that polyFe was intercalated into the SP nanosheets. Interestingly, the redox potential of polyFe was lowered by combining it with SP, and the current was measurable despite the insulating nature of SP. X-ray photoelectron spectroscopy showed that the decrease in the redox potential observed in the SP-polyFe hybrid was caused by the electrostatic neutralization of the Fe cation in polyFe by the negative charge on SP. Electrochemical analyses indicated that electron transfer occurred through electron hopping across the SP-polyFe hybrid. Control experiments using a metal complex composed of Fe and two 2,2':6',2''-terpyridine ligands (terpyFe) showed that SP contributes to the effective electron hopping. This modulation of the electrochemical properties by the layered silicates could be applied to other electrochemical systems, including hybrids of the redox-active ionic species and ion-exchangeable adsorbents.

The prevalence of the condensed phase, interpenetration, and fragility of mesoporous coordination polymers (meso-PCPs) featuring dense open metal sites (OMSs) place strict limitations on their preparation, as revealed by experimental and theoretical reticular chemistry investigations. Herein, we propose a rational design of stabilized high-porosity meso-PCPs, employing a low-symmetry ligand in combination with the shortest linker, formic acid. The resulting dimeric clusters (PCP-31 and PCP-32) exhibit high surface areas, ultrahigh porosities, and high OMS densities (3.76 and 3.29 mmol g -1 , respectively), enabling highly selective and effective separation of C 2 H 2 from C 2 H 2 /CO 2 mixtures at 298 K, as verified by binding energy (BE) and electrostatic potentials (ESP) calculations.

One dimensional (1D) Pt(II)-based metallo-supramolecular polymer with carboxylic acids (polyPtC) was synthesized using a new asymmetrical ditopic ligand with a pyridine moiety bearing two carboxylic acids. The carboxylic acids in the polymer successfully served as apohosts for imidazole loaded in the polymer interlayer scaffold to generate highly ordered 1D imidazole channels through the metallo-supramolecular polymer chains. The 1D structure of imidazole loaded polymer (polyPtC-Im) was analyzed in detail by thermogravimetric analysis, powder X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and ultraviolet-visible and photoluminescence spectroscopic measurements. PolyPtC-Im exhibited proton conductivity of 1.5 × 10 -5 S cm -1 at 120 °C under completely anhydrous conditions, which is 6 orders of magnitude higher than that of the pristine metallo-supramolecular polymer.

Controlled cationic vinyl-addition polymerization of an alkyl vinyl ether (VE) and ring-opening polymerization of ε-caprolactone (CL) simultaneously proceeded using HfCl 4 /Hf(OBu) 4 as a dual-role catalyst for both mechanisms, yielding a graft copolymer consisting of a poly(VE) main chain and several poly(CL) side chains. The copolymer of conventionally incompatible monomers was generated via the unprecedented mechanisms consisting of orthogonal propagating reactions and transient merging. Specifically, the poly(CL) chains were incorporated into a poly(VE) chain through an exchange reaction between the VE-derived alkoxy group and the propagating poly(CL) chain at the acetal moiety of the propagating end of the poly(VE) chain. An appropriate ratio of HfCl 4 and Hf(OBu) 4 was indispensable for both the simultaneous vinyl-addition and ring-opening polymerizations and the alkoxy group exchange reaction.

Water-soluble helical Fe(II)-based metallosupramolecular polymers ((P)- and (M)-polyFe) were synthesized by 1:1 complexation of Fe(II) ions and bis(terpyridine)s bearing a (R)- and (S)-BINOL spacer, respectively. The binding affinity to calf thymus DNA (ct-DNA) was investigated by titration measurements. (P)-PolyFe with the same helicity as B-DNA showed 40-fold higher binding activity (K b = 13.08 × 10 7 M -1 ) to ct-DNA than (M)-polyFe. The differences in binding affinity were supported by electrochemical impedance spectroscopy analysis. The charge-transfer resistance (R ct ) of (P)-polyFe increased from 2.5 to 3.9 kΩ upon DNA binding, while that of (M)-polyFe was nearly unchanged. These results indicate that ionically strong binding of (P)-polyFe to DNA chains decreased the mobility of ions in the conjugate. Unique rod-like images were obtained by atomic force microscopy measurement of the DNA conjugate with (P)-polyFe, likely because of the rigid binding between DNA chains and the polymer. Differences in polymer chirality lead to significantly different cytotoxicity levels in A549 cells. (P)-PolyFe showed higher binding affinity to B-DNA and much higher cytotoxicity than (M)-polyFe. The helicity in metallosupramolecular polymer chains was important not only for chiral recognition of DNA but also for coordination to a biological target in the cellular environment.

Crystal phase and morphology of biominerals may be precisely regulated by controlled nucleation and selective crystal growth through biomineralization on organic templates such as a protein. We herein propose new control factors of selective crystal growth by the biomineralization process. In this study, a designed β-sheet Ac-VHVEVS-CONH2 peptide was used as a multifunctional template that acted as mineral source supplier and having crystal phase control ability of calcium carbonate (CaCO3) during a self-supplied mineralization. The peptides formed three-dimensional nanofiber networks composed of assembled bilayer β-sheets. The assembly hydrolyzed urea molecules to one carbonate anion and two ammonium cations owing to a charge relay effect between His and Ser residues under mild conditions. CaCO3 was selectively mineralized on the peptide assembly using the generated carbonate anions on the template. Morphology of the obtained CaCO3 was fiber-like structure, similar to that of the peptide template. The mineralized CaCO3 on the peptide template had aragonite phase. This implies that CaCO3 nuclei, generated using the carbonate anions produced by the hydrolysis of urea on the surface of the peptide assembly, preferentially grew into aragonite phase, the growth axis of which aligned parallel to the direction of the β-sheet fiber axis.

Linear Fe(II)-based metallo-supramolecular polymer chains were precisely aligned by the simple replacement of the counteranion with an N,N'-bis(4-benzosulfonic acid)perylene-3,4,9,10-tetracarboxylbisimide (PSA) dianion, which linked the polymer chains strongly. A parallel alignment of the polymer chains promoted by the PSA dianions yielded nanosheets formation. The nanosheets' structure was analyzed with FESEM, HRTEM, UV-vis, and XRD in detail. The nanosheets showed more than 5 times higher proton conductivity than the original polymer due to the smooth ionic conduction through the aligned polymer chains. The complex impedance plot with two semicircles also suggested the presence of grain boundaries in the polymer nanosheets.

We recently reported on newly synthesized S-galactosyl oligo(Arg) conjugates to overcome the serious problem of the passage through the E. coli cell membrane. Following in vivo expression of green fluorescent protein (GFP) induced by each of the S-galactosyl (Arg)n constructs (n = 5, 6, 8) at the T5 promoter in E. coli for 18 h, we visually observed that the cultures fluoresced green light when excited with UV light. The fluorescence intensities for these cultures were greater than that found for a control culture, indicating that the peptides had induced GFP expression. In order to accomplish higher expression efficiency, we investigated the cluster effect and structural fine-tuning of new poly(2-oxazoline) containing CysArgArg as the cell-penetrating peptide (CPP) and S-galactosides when acting as inducers of recombinant protein expression under the control of lac operator/repressor systems in this article. Quantitative fluorescence intensities (calculated per molecule) also supported the observations that the cell-penetrating glyco poly(2-oxazoline)s were better inducers of GFP expression than glyco poly(2-oxazoline) containing no CPP or isopropyl β-d-thiogalactoside. Because the level of GFP expression was directly related to the number of sugar residues in each glyco poly(2-oxazoline), we propose that a cluster effect of the S-galactosides attached to the cell-penetrating poly(2-oxazoline) is responsible for how well the galactosides inhibited the lac repressor to activate the protein expression under the control of the lac operator/repressor system. A similar tendency was observed when the T7 promoter was placed upstream of the gene for an artificial extracellular matrix protein and glyco poly(2-oxazoline)s-CPP conjugates were used as inducers. To assess how the glyco poly(2-oxazoline) penetrate the cell membrane, we labeled the glyco poly(2-oxazoline) using 1-amino pyrene and directly observed the penetration process. Furthermore, we could visualize protein expression under the control of a lac promoter/operator/repressor system using transmission electron microscopy combined with energy dispersive X-ray analysis mapping.

A three-step synthetic method for the preparation of fluoranthenes, involving Miura's intermolecular C-H arylation, nonaflation, and intramolecular C-H arylation, has been developed. Various 1-naphthols and haloarenes were successfully used as substrates. Reaction conditions that afford high site selectivity have been developed for the intramolecular C-H arylation step.

In this study, electrochemical responses of inkjet-printed multicolored electrochromic devices (ECD) were studied to evaluate the feasibility of presenting multiple colors in one ECD. Metallo-supramolecular polymers (MEPE) solutions with two primary colors were inkjet-printed on flexible electrodes. By digitally controlling print dosages of each species, the colors of the printed EC thin film patterns can be adjusted directly without premixing or synthesizing new materials. The printed EC thin films were then laminated with a solid transparent thin film electrolyte and a transparent conductive thin film to form an ECD. After applying a dc voltage, the printed ECDs exhibited great contrast with a transmittance change (ΔT) of 40.1% and a high coloration efficiency of 445 cm(2) C(-1) within a short darkening time of 2 s. The flexible ECDs also showed the same darkening time of 2 s and still had a high ΔT of 30.1% under bending condition. This study demonstrated the feasibility to fabricate display devices with different color setups by an all-solution process and can be further extended to other types of displays.

We document the development of PET probes for central AMPA receptors and their application to in vivo animal imaging. An initial screening of perampanel derivatives was performed to identify probe candidates. Despite the high autoradiographic contrast yielded by several radioligands, rat PET scans did not support their in vivo suitability. Further focused derivatization and a second screening by ex vivo LC-MS measurements led to the selection of 2-[1-(3-methylaminophenyl)-2-oxo-5-(pyrimidin-2-yl)-1,2-dihydropyridin-3-yl]benzonitrile, 21a, and its analogues as candidates. [(11)C]21a was shown by autoradiography to specifically bind to the neocortex and hippocampus, consistent with AMPA receptor localization. PET imaging with [(11)C]21a demonstrated moderate uptake of radioactivity in rat and monkey brains, with the retention of radiosignals being consistent with that from the autoradiogram data, and the uptake was blocked by pretreatment with unlabeled 21a in a dose-dependent manner. The current approach has facilitated the discovery of a PET probe potentially suitable for translational research and development focused on AMPA receptors.

A platinum(II)-based, luminescent, metallo-supramolecular polymer (PolyPtL1) having an inherent dipole moment was synthesized via complexation of Pt(II) ions with an asymmetric ligand L1, containing terpyridyl and pyridyl moieties. The synthesized ligand and polymer were well characterized by various NMR techniques, optical spectroscopy, and cyclic voltammetry studies. The morphological study by atomic force microscopy revealed the individual and assembled polymer chains of 1-4 nm height. The polymer was specifically attached on Au-electrodes to produce two types of film (films 1 and 2) in which the polymer chains were aligned with their dipoles in opposite directions. The Au-surface bounded films were characterized by UV-vis, Raman spectroscopy, cyclic voltammetry, and atomic force microscopy study. The quantum mechanical calculation determined the average dipole moment for each monomer unit in PolyPtL1 to be about 5.8 D. The precise surface derivatization permitted effective tuning of the direction dipole moment, as well as the direction of rectification of the resulting polymer-attached molecular diodes. Film 1 was more conductive in positive bias region with an average rectification ratio (RR = I(+4 V)/I(-4 V)) ≈ 20, whereas film 2 was more conducting in negative bias with an average rectification ratio (RR = I(-4 V)/I(+4 V)) ≈ 18.

Black-to-transmissive electrochromism has been obtained with a Co(II)-based metallo-supramolecular polymer (polyCo). Thin films of polyCo, based on bisterpyridine ligand assembled with Co(II) metal ion, were constructed by spray casting the polymer onto ITO glass. With such simple fabricating means to form good-quality films, polyCo films show stable switching at the central metal ion of the Co(II)/Co(I) redox reaction when immersed in aqueous solution. With an increase in the pH of the aqueous electrolyte solution from neutral, the film exhibits a color response due to the interaction between the d-orbital electron and hydroxide ions affecting the d-d* transition. As a result, a nearly transparent-to-black electrochromic performance can be achieved with a transmittance difference at 550 nm of 74.3% (81.9-7.6%) in pH 13 solution. The light absorption of the film can be tuned over light regions from visible to near-infrared with a large attenuation.

We propose and validate a simple strategy of vertex connection that can be used for framework design and pore size/type modulation to prepare a mother structure and another 10 highly porous isoreticular frameworks with unprecedented topology. Importantly, the potential accessible pore volumes (57-71%), pore sizes (6.8-11. 2 Å; 17.0-29.0 Å; 12.5-22.8 Å; 11.9-24.5 Å), and the pore shapes of this series of highly porous frameworks were simultaneously and systematically tuned. Interestingly, the pore size of IIa [Zn4O(L(2))2(BDC)0.5]{(CH3)2NH2} decreased a little less than that of IIc [Zn4O(L(2))2(2,6-NDC)0.5]{(CH3)2NH2}; however, its selectivity of CO2 toward CH4 increased by almost two times.

Various properties of supported lipid bilayers such as diffusion and lipid partitioning are well characterized. However, little attention has been paid to their molecular packing density. In this work, the adsorption of 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) vesicles on glass and silicon dioxide was investigated using fluorescence microscopy, quartz crystal microbalance-dissipation (QCM-D), and atomic force microscopy. Fluorescence recovery after photobleaching data showed that the adsorption of large unilamellar vesicles (LUVs) on glass yielded supported bilayers with full mobility under alkaline (pH 8.3) and acidic (pH 3-4) conditions. These fluid bilayers exhibited quite different diffusion constants; those at alkaline pH were ~10 times larger than those at acidic pH. The reason for this pH dependence was clarified by investigation of the rupture of giant unilamellar vesicles (GUVs) on glass. Fluorescence data revealed that the area of planar bilayer patches increased at alkaline pH. Thus, we conclude that the rapid diffusion in alkaline solution arises from the decreased molecular density. QCM-D data showed that dissipation increased in a stepwise manner during vesicle fusion on silicon dioxide at alkaline pH. We attribute this behavior to the decrease in packing density of planar bilayers.

A series of Fe(II)-based metallo-supramolecular polymers with three-dimensional (3-D) structures were synthesized by the stepwise complexation of an Fe(II) salt with different ratios of a linear bis(terpyridine) ligand and a branched tris(terpyridine) ligand. Atomic force microscopy images of the polymer films showed a drastic change in the surface morphology upon varying the amount of the branched ligand. The surface of a designed 3-D construction film showed a highly porous structure (pore size: approximately 30-50 nm in diameter), probably due to the formation of a hyperbranched polymer structure. All the 3-D polymers had a blue color based on the metal-to-ligand charge-transfer (MLCT) absorption and exhibited excellent electrochromic properties. The most highly porous 3-D-structured film showed the best electrochromic performance; as compared with a 1-D linear polymer, the switching times were improved 38.7% for the coloring (0.31 → 0.19 s) and 37.9% for the bleaching (0.58 → 0.36 s). The transmittance change (ΔT) increased 21.8% (41.6 → 50.7%). Also, the coloration efficiency (η) was enhanced 45.3% (263.8 → 383.4 cm(2) C(-1)). The redox in the 3-D film was diffusion-controlled, as supported by the linear relationship between the current and square root of the scan rate. It is considered that the porous structure of the 3-D polymer films contributed to smooth ionic transfer during the redox and to the improved electrochromic properties.

Orexin receptors (OXRs) in the brain have been implicated in diverse physiological and neuropsychiatric conditions. Here we describe the design, synthesis, and evaluation of OXR ligands related to (1R,2S)-2-(((2-methyl-4-methoxymethylpyrimidin-5-yl)oxy)methyl)-N-(5-fluoropyridin-2-yl)-2-(3-fluorophenyl)cyclopropanecarboxamide (9a) applicable to positron emission tomography (PET) imaging. Structural features were incorporated to increase binding affinity for OXRs, to enable carbon-11 radiolabeling, and to adjust lipophilicity considered optimal for brain penetration and low nonspecific binding. 9a displayed nanomolar affinity for OXRs, and autoradiography using rat brain sections showed that specific binding of [(11)C]9a was distributed primarily to neocortical layer VI and hypothalamus, consistent with reported localizations of orexin-2 receptors (OX2Rs). In vivo PET study of [(11)C]9a demonstrated moderate uptake of radioactivity into rat and monkey brains under deficiency or blockade of P-glycoprotein, and distribution of PET signals in the brain was in agreement with autoradiographic data. Our approach and findings have provided significant information for development of OX2R PET tracers.

A family of new porous coordination polymers (PCPs) were prepared by the reaction of an acylamide modified ligand (H3L) and RE(NO)3·xH2O (RE = Y, La, Ce, Nd, Eu, Tb, Dy, Ho, and Tm). PXRD and single-crystal X-ray analyses of them revealed that, besides the La PCP, all other rare earth members gave isomorphous structures. The two types of structural toplogies obtained, although similar, differ in their alignment of acylamide functional groups and structural flexibility. Adsorption experiments and in situ DRIFT spectra showed that rigid frameworks have the typical microporous behavior and poor selective capture of CO2 over C2H4 and C2H6; however, the unique La-PCP with structural flexibility and close-packed acylamide groups has a high selective capture of CO2 with respect to C2H6 or C2H4 at 273 K, especially at the ambient pressure area (0.1-1 bar).

High selectivity and low-energy regeneration for adsorption of CO(2) gas were achieved concurrently in a two-dimensional Cu(II) porous coordination polymer, [Cu(PF(6))(2)(4,4'-bpy)(2)](n) (4,4'-bpy = 4,4'-bipyridine), containing inorganic fluorinated PF(6)(-) anions that can act as moderate interaction sites for CO(2) molecules.

Previously, we have shown that consuming carbohydrate plus whey protein hydrolysates (WPHs) replenished muscle glycogen after exercise more effectively than consuming intact whey protein or branched-chain amino acids (BCAAs). The mechanism leading to superior glycogen replenishment after consuming WPH is unclear. In this 5 week intervention, ddY mice were fed experimental diets containing WPH, a mixture of whey amino acids (WAAs), or casein (control). After the intervention, gastrocnemius muscle glycogen levels were significantly higher in the WPH group (4.35 mg/g) than in the WAA (3.15 mg/g) or control (2.51 mg/g) groups. In addition, total glycogen synthase (GS) protein levels were significantly higher in the WPH group (153%) than in the WAA (89.2%) or control groups, and phosphorylated GS levels were significantly decreased in the WPH group (51.4%). These results indicate that dietary WPH may increase the muscle glycogen content through increased GS activity.

Hydroxyapatite is mineralized along the long axis of collagen fiber during osteogenesis. Mimicking such biomineralization has great potential to control inorganic structures and is fast becoming an important next-generation inorganic synthesis method. Inorganic matter synthesized by biomineralization can have beautiful and functional structures that cannot be created artificially. In this study, we applied biomineralization to the synthesis of the only photocatalyst in practical use today, titanium dioxide (TiO(2)). The photocatalytic activity of TiO(2) mainly relates to three properties: morphology, crystal phase, and light-use efficiency. To optimize TiO(2) morphology, we used a simple sequential peptide as an organic template. TiO(2) mineralized by a β-sheet peptide nanofiber template forms fiber-like shapes that are not observed for mineralization by peptides in the shape of random coils. To optimize TiO(2) crystal phase, we mineralized TiO(2) with the template at 400 °C to transform it into the rutile phase and at 700 °C to transform it into a mixed phase of anatase and rutile. To optimize light-use efficiency, we introduced nitrogen atoms of the peptide into the TiO(2) structure as doped elemental material during sintering. Thus, this biomineralization method enables control of inorganic morphology, crystal phase, and light-use efficiency in a single process.

A cyclic compound that has alternating diphenylamine and quinodiimine units was obtained by condensation of anthraquinone with bis(4-aminophenyl)amine (aniline dimer) in 20% yield. The resulting macrocycle has an absorption of 462 nm, which is assigned to charge transfer transitions between electron-rich diphenylamine units and electron-poor anthraquinone diimine units. Cyclic voltammetry in acidic MeCN shows redox of anthraquinone diimine units (E(1/2) = 0.03 V vs Ag/Ag(+)) and of oxidation of amino groups of higher potentials (0.60 and 0.77 V).

We fabricated a vertically and unidirectionally oriented metal coordinated α-helical peptide monolayer, Leu(2)Ala(Pyri)(Co(II))Leu(6)Ala(4-Pyri)(Co(II))Leu(6), by stepwise polymerization on a mixed self-assembled monolayer consisting of amino-alkanethiol, dialkyl disulfide, and ferrocenyl alkanethiol acted as a photoresponsive electron donor. Redox-active protein, nitrate reductase (NR), was fixed on the surface of the peptide monolayer. By contrast, we fixed NR on the mixed self-assembled monolayer directly. Upon photoirradiation, electron flow occurred from the excited ferrocenyl group on the substrate to the electron acceptor, NR, on the surface of the molecular layers. The activated NR on the molecular layers reduced the nitrate to nitrite. The amount of the bioelectrocatalytic product, nitrite, generated by the immobilized NR on the peptide monolayer was larger than that produced by the immobilized NR on the mixed self-assembled monolayer directly. That is to say, the NR on the peptide monolayer has been more activated rather than that on the peptide absent monolayer by photoirradiation. The effective activation of the NR on the peptide monolayer can be explained in terms of enhancement of the vectorial electron flow along the macro-dipole moment of the α-helical peptide that arranged unidirectionally. It suggested that the ordered metal coordinated α-helical peptide monolayer acted as an efficient electron mediator to achieve a communication between the electron donor and the redox-active moiety. Such a hybrid molecular system looks promising for novel nanodevices, such as nano-photoreactors., (© 2011 American Chemical Society)

In vivo incorporation of phenylalanine (Phe) analogues into an artificial extracellular matrix protein (aECM-CS5-ELF) was accomplished using a bacterial expression host that harbors the mutant phenylalanyl-tRNA synthetase (PheRS) with an enlarged binding pocket. Although the Ala294Gly/Thr251Gly mutant PheRS (PheRS**) under the control of T5 promoter allows incorporation of some Phe analogues into a protein, the T5 system is not suitable for material science studies because the amount of materials produced is not sufficient due to the moderate strength of the T5 promoter. This limitation can be overcome by using a pair of T7 promoter and T7 RNA polymerase instead. In the T7 expression system, it is difficult, however, to achieve a high incorporation level of Phe analogues, due to competition of Phe analogues for incorporation with the residual Phe that is required for synthesis of active T7 RNA polymerase. In this study, we prepared the PheRS** under T7 promoter and optimized culture condition to improve both the incorporation level of recombinant aECM protein and the incorporation level of Phe analogues. Incorporation and expression levels tend to increase in the case of p-azidophenylalanine, p-iodophenylalanine, and p-acetylphenylalanine. We evaluated the lower critical transition temperature, which is dependent on the incorporation ratio and the turbidity decreased when the incorporation level increased. Circular dichromism measurement indicated that this tendency is based on conformational change from random coil to β-turn structure. We demonstrated that polyethylene glycol (PEG) can be conjugated at reaction site of Phe analogues incorporated. We also demonstrated that the increased hydrophilicity of elastin-like sequences in the aECM-CS5-ELF made by PEG conjugation could suppress nonspecific adhesion of human umbilical vein endothelial cells (HUVEC).

We have demonstrated a unique method for rational arrangement of gold (Au) nanoparticles on a β-sheet peptide template through nucleobase pairing. For the template, the 16-mer peptide 1 was synthesized, which is based on an alternating amphiphilic sequence of Asp-Leu. Here Leu at the sixth position is replaced by thymine-modified Lys, and a polyethylene glycol chain is introduced to the C-terminus. The surface of Au nanoparticles was modified with the complementary adenyl group. Peptide 1 formed a stable β-sheet monolayer at the air/water interface under an appropriate surface pressure. The monolayer film transferred onto a mica surface by the Langmuir-Blodgett method showed a linearly striped pattern with 6.1 nm average stripe width and 6 nm average interval between stripes, derived from β-sheet assembly. The adenine-bound Au nanoparticles were successfully immobilized on the thymine-bound template through a complementary adenine-thymine hydrogen bonding pair. Interestingly, linear assembly structures of the Au nanoparticles were observed, thus being successfully reproduced by the original striped pattern of the template of 1. Our method might readily fabricate Au materials with our desirable 2D pattern through fine-tuning of β-sheet sequence and nucleobase position., (© 2011 American Chemical Society)

New gold nanoparticles covered with cyclic phenylazomethine (CPA) were obtained by a one-pot synthesis. It is confirmed by XPS that imines of CPA in the nanoparticles (Au-CPA) are partially reduced to amines. The amine part of CPA in Au-CPA is attached to the surfaces of gold nanoparticles, and the imine part works as a redox-active site. A glassy carbon electrode modified with Au-CPA was revealed to work as an electrochemical probe for metal ion sensing., (© 2011 American Chemical Society)

We studied the effect of surface-functional-group position on precipitate morphology in the earliest stage of calcium phosphate biomineralization and determined the detailed mechanism of precipitation starting from nucleation to precipitate growth. The biomineralization template was a β-sheet peptide scaffold prepared by adsorption with carboxyl groups arranged at strict 7 Å intervals. Phosphate was then introduced. Within 10 s, highly ordered embryos of calcium phosphate were formed and confined by a peptide nanofiber pattern. They repeatedly nucleated and dissolved, with the larger embryos absorbing the smaller ones in a clear demonstration of an Ostwald-ripening-like phenomenon, then aggregated in a line pattern, and finally formed highly ordered nanofibers of amorphous calcium phosphate. This multistep growth process constitutes the earliest stage of biomineralization.

The electrochromic properties of a polythiophene polyrotaxane film consisting of a polythiophene backbone wrapped by the tetra-cationic cyclophane, cyclobis(paraquat-p-phenylene), were characterized. A naked reference polythiophene film, i.e., polythiophene without tetra-cationic cyclophane, was also characterized. The surface morphology and thickness of the film (L) were observed by atomic force microscopy. The surface of the naked reference polythiophene film has micrometer-scale polythiophene aggregates, which causes the darker color of the film and smaller color contrast in the electrochromic process. The polythiophene polyrotaxane gives a more homogeneous and brighter colored film owing to the suppression of molecular interactions between the polythiophene chains by the tetra-cationic cyclophanes. Potential-step chronoamperometric measurement provided the area density of the oxidizable sites (Γ) and the apparent diffusion coefficient of the charge transport in the film. From linear relationship between L and Γ, the concentrations of the oxidizable sites in the polythiophene polyrotaxane and naked reference polythiophene films were calculated to be 1.3 and 2.4 mmol cm(-3), respectively. Interestingly, the polythiophene polyrotaxane film afforded a significantly larger apparent diffusion coefficient than the naked reference polythiophene film. This result suggests that the rate-determining step of the charge transport is not the electron hopping between the polythiophene chains but the transport of charge-compensating counterions from the solvent into the polythiophene. We believe that the counteranions of the tetra-cationic cyclophane provide a pathway allowing the charge-compensating counteranions to migrate from the solvent to polythiophene. The polythiophene polyrotaxane film showed faster color change than the naked reference polythiophene film in the electrochromic reaction. These results indicate that our polythiophene polyrotaxane is a better electrochromic material than the naked reference polythiophene.

We have fabricated a unique memristive device by molecular engineering and demonstrated that the leakage current tuning in the device is 100 times more efficient than that in a standard device. Molecular analogs of the memristive matrices used here are an electrochemically active conjugated Co(III) polymer (CP) and a nonconjugated Co(III) polymer (NCP), which have been synthesized in good yield and characterized by (1)H NMR spectroscopy. Redox switching of an organic-metallic hybrid polymer generates bistable states with a large ON/OFF ratio that supports random flip-flops for several hours. Thus, we provide a synthetic solution to leakage current restriction, one of the fundamental problems faced when fabricating state-of-the-art electronic devices.

Here we describe the design, synthesis, and evaluation of physicochemical and pharmacological properties of D(4) dopamine receptor ligands related to N-[2-[4-(4-chlorophenyl)piperazin-1-yl]ethyl]-3-methoxybenzamide (2). Structural features were incorporated to increase affinity for the target receptor, to improve selectivity over D(2) and σ(1) receptors, to enable labeling with carbon-11 or fluorine-18, and to adjust lipophilicity within the range considered optimal for brain penetration and low nonspecific binding. Compounds 7 and 13 showed the overall best characteristics: nanomolar affinity for the D(4) receptor, >100-fold selectivity over D(2) and D(3) dopamine receptors, 5-HT(1A), 5-HT(2A), and 5-HT(2C) serotonin receptors and σ(1) receptors, and log P = 2.37-2.55. Following intraperitoneal administration in mice, both compounds rapidly entered the central nervous system. The methoxy of N-[2-[4-(3-cyanopyridin-2-yl)piperazin-1-yl]ethyl]-3-methoxybenzamide (7) was radiolabeled with carbon-11 and subjected to PET analysis in non-human primate. [(11)C]7 time-dependently accumulated to saturation in the posterior eye in the region of the retina, a tissue containing a high density of D(4) receptors.

Supported phospholipid bilayers can be formed by established methods such as vesicle fusion and the Langmuir-Blodgett (LB) technique. However, challenges remain in regards to creating supported bilayers from various lipid compositions, using various support surfaces, and incorporating membrane proteins. Here we report a detergent removal method as an alternative means of supported bilayer formation. The process consists of three steps: (1) incubation of phospholipid-poly(ethylene glycol) (PEG)-grafted glass with lipid-detergent micelles; (2) detergent removal by washing the surface with vesicles; and (3) incubation with the vesicles to complete lipid adsorption. These procedures yielded fluid planar bilayers of zwitterionic lipids. Because fluid structures were not obtained by vesicle fusion, the detergent seemed necessary to produce the polymer-supported bilayers. While anionic phospholipids inhibited the attachment of fluid bilayers in the absence of calcium ions, supported bilayers with almost full mobility were obtained from lipid mixtures containing 10-20 mol % anionic lipids in the presence of calcium ions. The incorporation of the anionic lipids in the bulk-facing leaflet was demonstrated by the binding of dye-labeled annexin V.

The effect of protein fractionation on the bioavailability of amino acids and peptides and insulin response and whether the protein source influences these effects in humans are poorly understood. This study compared the effects of different sources and degrees of hydrolysis of dietary protein, independent of carbohydrate, on plasma amino acid and dipeptide levels and insulin responses in humans. Ten subjects were enrolled in the study, with five subjects participating in trials on either soy or whey protein and their hydrolysates. Protein hydrolysates were absorbed more rapidly as plasma amino acids compared to nonhydrolyzed protein. Whey protein also caused more rapid increases in indispensable amino acid and branched-chain amino acid concentrations than soy protein. In addition, protein hydrolysates caused significant increases in Val-Leu and Ile-Leu concentrations compared to nonhydrolyzed protein. Whey protein hydrolysates also induced significantly greater stimulation of insulin release than the other proteins. Taken together, these results demonstrate whey protein hydrolysates cause significantly greater increases in the plasma concentrations of amino acids, dipeptides, and insulin.