Intermediate Color Emission via Nanographenes with Organic Fluorophores

Photoluminescence (PL) color can be tuned by mixing fluorophores emitting the three primary colors in an appropriate ratio. When color tuning is achieved on a single substrate, we can simplify device structures. We demonstrated that nanographenes (NGs), which are graphene fragments with a size of tens of nanometers, could be utilized as carriers of fluorophores. The addition of red- and blue-light-emitting fluorophores on the edge successfully reproduced the purple light. The relative PL intensities of the fluorophores could be regulated by the excitation wavelength, enabling multicolor emission between blue and red light. Owing to the triphenylamine units of the fluorophores, the NGs showed PL enhancement due to aggregation. This characteristic was valuable for the fabrication of solid polymer materials. Specifically, the functionalized NGs can be dispersed into polyvinylidene difluoride. The resultant polymer films emitted red, blue, and purple color. Our study demonstrated the potential applicability of NGs for fluorophore carriers capable of reproducing intermediate colors of light.

Adhesive Sulfabetaine Polymer Hydrogels for the Sandwich Cell Culture

Sandwich culture systems are techniques that cultivate cells by sandwiching them between the top and bottom substrates. Since the substrates can be separated, the system is expected to be applied to the construct layering of patterned cells and to the isolation of stacked cells. In this study, we prepared hydrogels composed of zwitterionic sulfabetaine polymers, poly[2-(2-(methacryloyloxyethyl)dimethylammonio)ethyl-1-sulfate] (PZBMA). The ZBMA homopolymers have been shown to form aggregates in aqueous solutions due to their intermolecular interactions. The water content of the PZBMA hydrogels in water was ∼70% regardless of N,N'-methylenebis(acrylamide), BIS, content as the cross-linker. The results indicated that the intermolecular interaction contributed more to the swelling behaviors than the chemical cross-linker. However, PZBMA hydrogels with 0.1 mol % BIS showed not only high elongation (∼850%) properties but also high adhesiveness and self-healing properties. When this PZBMA hydrogel was impregnated with collagen and subjected to sandwich culture using Madin-Darby canine kidney (MDCK) cells, a three-dimensional morphology of MDCK cell aggregates was constructed. Such a sulfabetaine hydrogel is expected to be developed for regenerative medicine.

Kinetic Resolution of Secondary Alcohols Catalyzed at the Exterior of Chiral Coordinated Capsules

Confined spaces inside molecular hosts can function as reaction vessels. However, this concept significantly limits the scope of reactants. When the exterior of molecular hosts is used instead, we can ease the restriction because reactants are not necessary to be trapped inside molecular hosts, although studies along this line have not been reported. As a proof-of-concept of enantioselective reactions at the exterior of chiral molecular hosts, we utilized host-guest complexes of enantiomerically enriched Cu-coordinated capsules and guests possessing a catalytic center to realize the kinetic resolution of secondary alcohols. Under suitable reaction conditions, a selectivity factor of 2.6 was realized, demonstrating that the reactions occur at the exterior of the capsules. A series of experiments indicated that the substituents on the 2,2'-bipyridyl arms and the alkyl chains on the lower rim contributed to the enantioselectivity of the reactions.

Molecular Recognition Process in Resorcinarene-based Coordination Capsules

Cu and Ag capsules can take up various organic molecules. Their molecular recognition possibly involves partial dissociation and slippage. We investigated molecular recognition processes in the Cu and Ag capsules by CD and 1 H NMR spectroscopy and employed 4,4'-diacetoxy biphenyl carrying two benzothiadiazole groups as a probe. CD and 1 H NMR measurements reveal that the host-guest complexation proceeds under second-order reactions and that these capsules undergo the partial dissociation to take up the probe in [D1 ]chloroform and [D8 ]THF. The slippage also contributes to host-guest complexation for a Cu capsule that carries p-methoxyphenyl groups on the 2,2'-bipyridiyl arms. DFT calculations suggest that π/π stacking interactions between the electron-rich p-methoxyphenyl group and the electron-poor 2,2'-bipyridyl arm elongate the capsule, allowing the guest to access the cavity without the partial dissociation.

Binding of Stimuli-Responsive Ruthenium Aqua Complexes with 9-Ethylguanine

Stimuli-responsive ruthenium complexes proximal- and distal-[Ru(C10tpy)(C10pyqu) OH2]2+ (proximal-1 and distal-1; C10tpy = 4'-decyloxy-2,2':6',2″-terpyridine and C10pyqu = 2-[2'-(6'-decyloxy)-pyridyl]quinoline) were experimentally studied for adduct formation with a model DNA base. At 303 K, proximal-1 exhibited 1:1 adduct formation with 9-ethylguanine (9-EtG) to yield proximal-[Ru(C10tpy)(C10pyqu)(9-EtG)]2+ (proximal-RuEtG). Rotation of the guanine ligand on the ruthenium center was sterically hindered by the presence of an adjacent quinoline moiety at 303 K. Results from 1H NMR measurements indicated that photoirradiation of a proximal-RuEtG solution caused photoisomerization to distal-RuEtG, whereas heating of proximal-RuEtG caused ligand substitution to proximal-1. The distal isomer of the aqua complex, distal-1, was observed to slowly revert to proximal-1 at 303 K. In the presence of 9-EtG, distal-1 underwent thermal back-isomerization to proximal-1 and adduct formation to distal-RuEtG. Kinetic analysis of 1H NMR measurements showed that adduct formation between proximal-1 and 9-EtG was 8-fold faster than that between distal-1 and 9-EtG. This difference may be attributed to intramolecular hydrogen bonding and steric repulsion between the aqua ligand and the pendant moiety of the bidentate ligand..

Brainwave activities reflecting depressed mood: a pilot study

Early diagnosis and treatment of depression are desirable but currently difficult due to a lack of established biomarkers. Although biomarkers for depression based on electroencephalogram (EEG) data have long been explored, most existing methods are thought to capture cognitive decline caused by depression and are unsuccessful in detecting signs of depression. Here we report that some brainwave activities involving phase resetting reflect the depressed mood at the time, which can be easily monitored by measuring the resting EEG with eyes closed for 1 min with a few electrodes. We instructed 10 participants (nine healthy and one diagnosed with depression, aged 18-34) to record their EEG for 14-26 days. We found that indicators of depressed mood were correlated with the occurrence frequency of EEG phase resetting. For most participants, the correlation coefficients swung systematically between large positive and large negative values with respect to EEG frequency; however, the frequencies at which they were maximum or minimum differed among participants. Although this study is in the pilot phase and needs further experimentation, the results are expected to lead to innovative biomarkers for early detection of depression and may contribute to a better understanding and treatment of depression.

External Flash Generation of Carbenoids Enables Monodeuteration of Dihalomethanes

In this study, incorporation of one deuterium atom was achieved by H-D exchange of one of the two identical methylene protons in various dihalomethanes (halogen=Cl, Br, and I) through a rapid-mixing microflow reaction of lithium diisopropylamide as a strong base and deuterated methanol as a deuteration reagent. Generation of highly unstable carbenoid intermediate and suppression of its decomposition were successfully controlled under high flow-rate conditions. Monofunctionalization of diiodomethane afforded various building blocks composed of boryl, stannyl, and silyl groups. The monodeuterated diiodomethane, which served as a deuterated C1 source, was subsequently subjected to diverted functionalization methods to afford various products including biologically important molecules bearing isotope labelling at specific positions and homologation products with monodeuteration.

The Differences of Gambling-Related Harms Among Low-Investment and Normal-Investment Pachinko/Pachislot Players in Japan: A Cross Sectional Study

Pachinko and pachislot are popular types of gambling activities in Japan. Prior studies in Japan have reported a concerning prevalence of problem gambling among adult players. While these studies have identified various gambling-related harms, Japanese research on harm-minimization strategies is scarce. Therefore, the present study aimed to compare differences of gambling-related harms among normal-, half-, and quarter-pachi players to the usefulness of low-investment pachinko and pachislot as a harm-reduction strategy. We considered gamblers who played games that cost the typical amount of money to be "normal-pachi players." Those who played low-investment games were categorized as "half-pachi players" and "quarter-pachi players," reflecting those who played games at half or one quarter the cost of a typical machine, respectively. To assess the harm-reduction effect, a one-way ANCOVA was conducted to compare the impact of the groups (normal-pachi players [n = 101], half-pachi players [n = 104], and quarter-pachi players [n = 100]) on dependent variables, namely the number of days players had gambled during the prior month; total time and amount of money spent on gambling; debts caused by gambling; gambling severity; cognitive distortion; depressive symptoms; and problems in work, family, and social life. We demonstrated that the amount of money spent by quarter-pachi players on gambling during the past month was lower than that of normal-pachi players. However, we did not find significant differences with respect to any other gambling-related harms among normal-, half-, and quarter-pachi players. Low-investment pachinko and pachislot players spends less the amount of money spent on gambling. Low-investment pachinko and pachislot would thus partly act as a harm-minimization strategy. Moreover, the results of the present study indicate that the problems at work affect various outcomes for gamblers. Given that 90% of the participants in this study were employed, the results of this study may have important implications for employed gamblers.

Preparation of size-controlled LiCoPO4 particles by membrane emulsification using anodic porous alumina and their application as cathode active materials for Li-ion secondary batteries

Membrane emulsification using anodic porous alumina is an effective method for preparing monodisperse droplets with controlled sizes. In this study, membrane emulsification using anodic porous alumina was applied to the preparation of size-controlled particles composed of composite metal oxides. To obtain size-controlled composite metal oxide particles, membrane emulsification was performed using an aqueous solution containing a water-soluble monomer and metal salts as a dispersed phase. After the membrane emulsification, composite metal oxide particles were obtained by solidifying the droplets in a continuous phase and subsequent heat treatment. Here, as a demonstration of this process, the fabrication of size-controlled LiCoPO₄ particles, which are considered high-potential cathode active materials for Li-ion secondary batteries (LIBs), was investigated. The application of the obtained LiCoPO₄ particles as cathode active materials for LIBs was also investigated. The results of this study showed that LiCoPO₄ particles with controlled sizes could be fabricated on the basis of this process and that their cathode properties could be improved by optimizing the heat treatment conditions and particle sizes. According to this process, size-controlled particles composed of various metal oxides can be fabricated by changing the metal salt in the dispersed phase, and the resulting size-controlled particles are expected to be applied not only as cathode active materials for LIBs but also as components of various functional devices.

Severity of Menstrual Pain Is Associated with Nutritional Intake and Lifestyle Habits

Recently, the employment rate of women in Japan has steadily increased. Approximately 80% of women experience menstrual pain and premenstrual syndrome (PMS). These symptoms decrease a woman's quality of life and her work productivity, leading to an economic loss. This cross-sectional study of 321 healthy Japanese women aged 20-39 years aimed to clarify the lifestyle-related factors or nutrient intake that might cause menstrual pain. The participants underwent body composition measurements and completed meal survey sheets and lifestyle questionnaires, including menstrual status, exercise, sleep and breakfast consumption. Based on the questionnaire results, participants were divided into two groups according to the severity of menstrual pain, namely, heavy and light. Chi-square and Wilcoxon signed-rank sum tests were used to compare the severity of menstrual pain in the two groups. In the heavy group, the intake of animal proteins, including fish, vitamin D and vitamin B12, was significantly lower (p < 0.05), as was the frequency of breakfast consumption and bathing (p < 0.05). The rate of PMS symptoms was significantly higher in the heavy group (p < 0.05). This study suggests that a lack of animal protein, the accompanying vitamins and fatty acids, and the frequency of breakfast or bathing are associated with the severity of menstrual pain.

Particle Size-Dependent Component Separation Using Serially Arrayed Micro-Chambers

The purpose of this research was to enable component separation based on simple control of the flow rate. We investigated a method that eliminated the need for a centrifuge and enabled easy component separation on the spot without using a battery. Specifically, we adopted an approach that uses microfluidic devices, which are inexpensive and highly portable, and devised the channel within the fluidic device. The proposed design was a simple series of connection chambers of the same shape, connected via interconnecting channels. In this study, polystyrene particles with different sizes were used, and their behavior was evaluated by experimentally observing the flow in the chamber using a high-speed camera. It was found that the objects with larger particle diameters required more time to pass, whereas the objects with smaller particle diameters flowed in a short time; this implied that the particles with a smaller size could be extracted more rapidly from the outlet. By plotting the trajectories of the particles for each unit of time, the passing speed of the objects with large particle diameters was confirmed to be particularly low. It was also possible to trap the particles within the chamber if the flow rate was below a specific threshold. By applying this property to blood, for instance, we expected plasma components and red blood cells to be extracted first.

Reinforcement effect in tandemly sulfonated, partially fluorinated polyphenylene PEMs for fuel cells

The mechanical and chemical durability is one of the most crucial properties for proton exchange membranes in practical fuel cell applications. In the present paper, we report the physical reinforcement of chemically stable, highly proton conductive tandemly sulfonated, partially fluorinated polyphenylenes using porous polyethylene (PE). With the PE pores completely and homogeneously filled by ionomers through a push coating approach, the resulting reinforced membranes were more proton conductive (183.1-389.2 mS cm^-1) than the commercial perfluorinated ionomer (Nafion: 120.6-187.2 mS cm^-1) membrane at high humidity (80-95% RH). Benefiting from the tough PE supporting layer, the reinforced membranes outperformed the parent ionomer membranes in stretchability with maximum strain up to 453%. The combination of intrinsic chemical stability of partially fluorinated polyphenylene ionomers and physical reinforcement with PE substrates contributed for the reinforced membranes to achieving superior durability to survive more than 20 000 cycles in severe accelerated durability test combining OCV hold and wet/dry frequent cycling.

The Effects of the Presence of Others on Risky Betting in a Laboratory Gambling Task Among High-Risk Gamblers: A Cross-over Randomized Controlled Trial

We explored the effects of the presence of and cooperation with others on risky betting in a laboratory-based gambling task among high-risk gamblers. Specifically, we compared risky betting under solo, parallel, and cooperation conditions using a stratified randomized, cross-over design. Stratification was conducted according to participant age and gender. The participants were 40 Japanese adults (20 women, 20 men; mean age = 46, SD = 12.80). In the experiment, each participant conducted the Game of Dice Task (GDT) individually (solo condition), in parallel with another participant (parallel condition), and working together with another participant (cooperation condition). Linear mixed modeling results showed that when we controlled for previously specified covariates, there were no significant differences among the solo, parallel, and cooperation conditions regarding risky betting (parallel: estimates = 0.10, SE = 0.79, p = .900; cooperation: estimates = 0.95, SE = 0.79, p = .232). However, post-hoc analysis showed a significant difference between the solo and cooperation conditions regarding the number of times participants chose the riskiest bet (parallel: estimates = 0.18, SE = 0.52, p = .739; cooperation: estimates = 1.13, SE = 0.53, p = .035). Thus, we found that neither the presence of nor cooperation with others decreased risky betting in the GDT among high-risk gamblers. However, we did observe that participants displayed the riskiest betting behavior (i.e., selecting the single choice) in the GDT during the cooperation condition, compared with the solo condition.

Properties and Morphologies of Anion-Exchange Membranes with Different Lengths of Fluorinated Hydrophobic Chains

An anion-exchange electrolyte membrane, QPAF(C6)-4, polymerized with hydrophobic 1,4'-bis(3-chlorophenyl)perfluorohexane and hydrophilic (6,6'-(2,7-dichloro-9H-fluorene-9.9-diyl)bis(N,N-dimethylhexan-1-amine) is physically flexible and chemically stable. The drawbacks are relatively large water swelling and lower OH^- conductivity at higher water uptakes, which are considered to be due to the entanglement of the flexible hydrophobic structure of the membrane. In this study, a QPAF(C4)-4 membrane was newly synthesized with shortened hydrophobic fluoroalkyl chains. Unexpectedly, QPAF(C4)-4 showed a higher water uptake and a lower bulk/surface conductivity than QPAF(C6)-4 possibly due to the decrease in hydrophobicity with a smaller number of fluorine atoms. The thermal stability of QPAF(C4)-4 was higher than that of QAPF(C6)-4, possibly due to the rigidity of the QAPF(C4)-4 structure. A higher mechanical strength of QAPF(C6)-4 than that of QPAF(C4)-4 could be explained by the larger interactions between molecules, as shown in the ultraviolet-visible spectrum. The interactions of molecules were understood in more detail with density functional theory calculations. Both the chemical structures of the polymers and the arrangements of the polymers in the membranes were found to influence the membrane properties.

Alginate-Stabilized Gold Nanoparticles Prepared Using the Microwave-Induced Plasma-in-Liquid Process with Long-Term Storage Stability for Potential Biomedical Applications

A one-step preparation of alginate-stabilized gold nanoparticles (Au NPs) using the microwave-induced plasma-in-liquid process (MWPLP) was reported. Effects of alginate with various concentrations on the preparation and properties of the synthesized Au NPs, including reaction rate, morphology, size, and optical absorption property, were studied. The introduction of alginate (1) accelerated the reaction rate, (2) prevented aggregation and precipitation due to long time discharge in MWPLP, and (3) provided long-term colloidal stability. An abnormal size change (from large to small) of Au NPs during particle growth, which was opposite to the typical change in bottom-up chemical reduction, was observed and a possible mechanism was proposed based on the dynamical and thermodynamical instability of particles during growth. The strategy of drying and redispersion of Au NPs in alginate solution was also studied. The drying and redispersion process had an imperceptible effect on the Au NPs. As a consequence, this strategy might be an effective technique for the long-term storage of Au NPs and other metal NPs. The alginate-stabilized Au NPs without the addition of toxic reducing or stabilizing agents can be appropriate to biomedical applications.

Anion exchange membranes containing no β-hydrogen atoms on ammonium groups: synthesis, properties, and alkaline stability

Novel anion conductive polymer membranes have been designed and synthesized to investigate whether the absence of β-hydrogen atoms of ammonium groups affects the membranes' properties and chemical stability. The hydrophilic monomer, 2,2-bis(4-chlorobenzyl)-2-phenyl-ethylamine (3), was obtained via a two-step reaction with an overall yield of 98% under mild reaction conditions. Ni(0)-promoted copolymerization of 3 with 2,2-bis(4-chlorophenyl)hexafluoropropane (1) afforded high molecular weight copolymers (M n = 12.8-19.6 kDa, M w = 82.1-224.6 kDa). After quaternization with iodomethane, QBAF-BS polymers formed bendable, robust membranes from solution casting. The ion exchange capacity (IEC) of the membranes ranged from 1.50 to 2.44 mequiv. g-1. The membranes exhibited high hydroxide ion conductivity in water (up to 191 mS cm-1 at 80 °C for IEC = 2.25 mequiv. g-1), suggesting that the newly designed hydrophilic structure was effective in improving the ion conductivity. Based on small-angle X-ray scattering (SAXS) analyses and transmission electron microscopy (TEM) images, all membranes featured nano-phase separated morphology with a large dependence on the copolymer composition. The strain properties were improved on increasing the content of the hydrophilic component up to IEC = 2.25 mequiv. g-1, above which the strain became smaller due to the larger water absorption. The membranes were not stable under harsh alkaline conditions (in 8 M KOH at 80 °C) gradually losing the hydroxide ion conductivity. Compared to our previous AEMs which contained typical aliphatic ammonium groups, the lack of β-hydrogen atoms did not practically improve the alkaline stability of AEMs possibly due to the main chain degradation but contributed to higher ion conductivity.