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The odd-even effects are renowned as a mysterious phenomenon in broad fields of science but have never been established as an effective approach for materials engineering. We demonstrate that the parity of alkyl carbon number n can cause alternating emergence of polar/antipolar organic semiconductor crystals. This is achieved by the development of a series of polar rod-like molecules, composed of a linkage between extended π-core (head) and alkyl chains (tail), exhibiting both high layered crystallinity and well-balanced end-to-end affinity. The molecules are unidirectionally aligned to form two-dimensional array, and the eventual polar monomolecular layers present two distinct types of interlayer stacking depending on the parity of n: alternating head-to-head and tail-to-tail (antipolar) alignment in odd-n crystals, and uniform head-to-tail (polar) alignment in even-n crystals. The latter allows to obtain polar semiconductor films that considerably improve interfacial carrier transport characteristics. The findings are key for creating polarity-controlled optoelectronic materials and devices.

Herein, we present the common structural features of a family of semiconducting molecular donor–acceptor (DA) compounds based on alkylated fused-ring thieno-acenes. Crystal structure analyses were conducted for 22 DA compounds of variously substituted benzothieno[3,2-b][1]benzothiophenes (BTBTs), unsubstituted dithieno[3,2-b:2’,3’-d]thiophene, and unsubstituted benzo[1,2-b:4,5-b’]dithiophene as donors, which were combined with 7,7,8,8-tetracyanoquinodimethane (TCNQ) and its fluorinated derivatives (FmTCNQ, m = 0, 1, 2, 4) as acceptors. Fourteen DA compounds of (substituted BTBT)(TCNQ derivative) formed isomorphous layered molecular packing, where the intermolecular stacking arrangements between the planar skeletons of BTBT and TCNQ were common to each other, and the various substituents played supplementary roles. Density functional theory calculations were conducted to investigate the intermolecular forces between π-electron cores along the DA stacks. Dispersion interactions were the dominant intermolecular attraction, showing weak stacking position dependence, while the short-range orbit–orbit interaction was always repulsive, irrespective of stacking. An important finding is that the orbit–orbit interaction has a relatively strong position dependence and leads to common structural features in the DA compounds. We discuss the origin of the isostructural nature of molecular DA compounds, which is crucial in searching for and exploring unique combinations of molecules with superior semiconducting characteristics., Journal of Materials Chemistry C, 10(43), pp.16471-16479; 2022

In this study, the effect of the Zone 30 policy on traffic accident reduction in Hyogo prefecture, Japan, was analyzed. Specifically, with the micro-districts (cho-cho-moku) of Hyogo prefecture as the analysis units, statistical verification was performed for the cross-section data of 2017, i.e., a few years after the introduction of the “30-km/h zones,” using the propensity score matching method for multiple treatments. The micro-districts of Hyogo prefecture were classified into three groups: Group 1 with no 30-km/h zones, Group 2 with 30-km/h zones but without physical devices, and Group 3 with 30-km/h zones and physical devices. The primary analysis results were as follows: The number of “Killed” or “Seriously Injured” (KSI) accidents in Group 3 tended to be lower than that in Group 1, whereas there were no significant differences between Groups 1 and 2. Moreover, the total number of traffic accidents in Group 3 was not less than that in Group 1. These results suggest that, at this point, designating an area as a 30-km/h zone, by itself, has negligible effect on reducing traffic accidents; conversely, such areas can effectively reduce the number of KSI accidents when combined with physical devices. In addition, as a verification method, it is empirically demonstrated that utilizing more than two groups is an effective approach for measuring the impact of traffic safety measures.

One of the often-used methods for in vitro evaluation of the blood compatibility of hemodialysis membranes is the circulation of human blood through a miniaturized hemodialyzer. The use of a rather small amount of human blood in its evaluation is one advantage of this method. However, because it is manufactured by a different process than actual ones, a miniaturized hemodialyzer membrane cannot always preserve the properties of actual hemodialyzers. To address this problem, we established a new experimental method that uses a relatively small amount of human blood and actual dialyzers. In this method, a test hemodialyzer and a control hemodialyzer filled with human blood obtained from the same donor is slowly rotated to prevent spontaneous blood cell sedimentation for 4 h at 37 °C. By use of this method, we were able to compare blood compatibility between a polysulfone (PS) membrane and a vitamin E (VE)-bonded PS membrane in terms of their relative antithrombotic, antioxidative, and anti-inflammatory properties. Consistent with many previous reports, the results clearly showed that compared with the PS membrane, VE-bonded PS membrane is more blood compatible. These findings suggest that our method is applicable, at least to in vitro blood compatibility evaluation of PS type dialysis membranes.

Herein, we developed a practical method to produce high-performance organic thin-film transistors (OTFTs) based on highly layered crystalline organic semiconductors (OSCs) that form bilayer-type layered herringbone (b-LHB) packing and exhibit high intrinsic mobility. We applied the insulating polymer blend technique using a typical b-LHB OSC of 2-octyl-benzothieno[3,2

Introduction: Acute blood purification therapy (BPT) has been evaluated in the context of intensive care for serious conditions related to systemic inflammation, but its mechanism and efficacy are not fully understood. Objective: This study examined the feasibility of using vitamin E-bonded polysulfone membranes (VEPS) for BPT in a LPS-induced rat model of systemic inflammation. Methods: To evaluate the efficacy of BPT with a VEPS membrane, polysulfone (PS) membranes conventionally used in intensive care were bonded with the antioxidant vitamin E and used in a rat model of lipopolysaccharide (LPS)-induced systemic inflammation. BPT using a PS membrane (PS group) or a VEPS membrane (VEPS group) was performed 6 h after administration of LPS. Extracorporeal circulation was established in normal rats as a control (sham group). Survival rates, histology of lung specimens, and levels of myeloperoxidase (MPO) and high mobility group box-1 (HMGB-1) were examined in each group. Results: Survival rates at 24 h after LPS administration were 100% in the VEPS group and 50% in the PS group. Pulmonary architecture was largely maintained and the level of infiltration of inflammatory cells remained moderate in the VEPS group. Levels of active MPO before and after BPT were significantly higher in the PS and VEPS groups than in the sham group, with no significant differences between the PS and VEPS groups. HMGB-1 levels were significantly elevated after BPT in the PS group. Conclusions: This study demonstrated that use of the VEPS membrane for BPT increased survival rate and reduced lung injury in a rat model of systemic inflammatory response syndrome (SIRS), suggesting the possible use of VEPS membranes in the treatment of serious conditions related to systemic inflammation.

Alkylamine/alkylacid-encapsulated silver nanocolloids (amac-AgNCs) present a unique coexistence of their dispersion stability as nanocolloids and fusion reactivity after drying. This feature is use...

Striation is effective for AC loss reduction of coated conductors, but it must be associated with twisting. Instead of direct twisting like in low Tc metallic superconductors, we spirally-twisted “striated and copper-plated coated conductor”, in which filaments are electrically connected. The thickness of the plated-copper was varied to examine its influence on filament decoupling. The magnetization losses of these conductors were measured along a transverse magnetic field with a small amplitude, where the coupling loss was dominant. From the frequency dependence of the measured magnetization loss, the coupling time constants of samples with different copper thicknesses, different spiral pitches, and different core diameters were determined. This study demonstrates filament decoupling by spiral twisting the striated and copper-plated coated conductors.

We experimentally studied the quench properties of REBa₂Cu₃Oy (RE-123) coated conductors with various plated-copper thicknesses (20 and 40 µm). A short sample of coated conductors was conduction-cooled to 45 K, a magnetic field (µ₀H, up to 2 T) was applied perpendicular to its wide face to control the critical current, an operating current was supplied, and subsequently quench was initiated using a small heater. Normal zone propagation velocities (NZPVs) were measured at various operating currents, and the NZPVs of coated conductors with various copper thicknesses were compared with each other. To understand the impact of the copper stabilizer on quench protection, hot-spot temperatures were measured during the processes that simulate quench detection using voltage taps and protection using dump resistor. The maximum hot-spot temperatures were plotted against the operating current as well as the overall current density, and the impact of the thickness of the copper stabilizer on hot-spot temperature was examined. The impact of the initial temperature on hot-spot temperature was also studied.

The construction and control of 2D layered packing motifs with π-extended fused-ring molecules is of crucial importance for developing organic electronic materials and devices. Herein, we demonstrate that, when adequately substituted, two kinds of layered packing motifs are obtainable for benzo[1,2-b:4,5-b′]bis[b]benzothiophene (BBBT), which itself does not show layered crystallinity. We synthesized BBBT derivatives substituted with a combination of alkyl chains and a phenyl ring in a symmetric/asymmetric manner, 2,8-didecyl-BBBT (diC10-BBBT) and 2-decyl-8-phenyl-BBBT (Ph-BBBT-C10). We found that diC10-BBBT forms a layered π-stack (LπS) structure mainly composed of slipped parallel stacks, while Ph-BBBT-C10 forms a typical layered herringbone (LHB) packing structure chiefly composed of T-shaped contacts. This feature is associated with the non-layered packing motif in BBBT: typical π-stack and herringbone structures, both of whose polymorphs show a large slip along the molecular long axis. Calculations of intermolecular interaction energies between neighbouring molecules in the crystals reveal that the interchain interactions suppress the long-axis slip, leading to the formation of the LπS and the LHB, respectively. Both diC10-BBBT and Ph-BBBT-C10 form uniform (ultra)thin films originating from the layered crystallinity, and exhibit good transistor characteristics with a hole mobility of about 1 cm2 V−1 s−1. We discuss how the substituent modifications are useful as crystal engineering to explore the potential of π-extended molecules for electronic applications.

In order to clarify the conditions for successful quench detection and protection of magnets wound with REBa2Cu3Oy (RE-123) coated conductors, experiments using short samples of copper-stabilized coated conductors were performed. A short sample of coated conductor was conduction-cooled to 30 K, a magnetic field was applied (µ0 H up to 2 T), a current was supplied, and subsequently quench was initiated using a small heater. When a normal voltage (over a preset threshold) was detected, the supplied current would be decreased exponentially. This procedure simulated the conventional quench detection (detecting voltage) and protection (using a dump resistor; current decaying exponentially with a time constant = coil inductance/resistance of dump resistor) for superconducting magnets. We examined how the critical current, time constant of current decrease, and voltage threshold for quench detection affected the hot-spot temperature. By comparing the critical currents and n values of a sample before and after quench, we identified the maximum current at which the sample exhibited no degradation (not-degrading current). The effect of transverse thermal diffusion and longitudinal thermal conduction was evaluated using one-dimensional/zero-dimensional quench simulation. The conditions for successful quench detection and protection were evaluated using not-degrading currents as well as the current at which the maximum hot-spot temperature reached 300 K.