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To enable the application of semiconducting single-walled carbon nanotubes (sc-SWNTs) in advanced technologies, the SWNT chiralities must be sorted from the mixture of as-synthesized SWNTs. Interes...

While quinoidal moieties are considered as emerging platforms showing efficient charge transport and interesting open-shell diradical characteristics, whether these properties could be changed by extension to the conjugated polymer structure remains as a fundamental question. Here, we developed and characterized two conjugated polymers incorporating quinoids with different lengths, which have a stable close- and open-shell diradical character, respectively, namely, poly(quinoidal thiophene-thienylene vinylene) (PQuT-TV) and poly(quinoidal bithiophene-thienylene vinylene) (PQuBT-TV). A longer length of a quinoidal core led to enhanced diradical characteristics. Therefore, the longer core length of QuBT was favorable for the formation of an open-shell diradical structure in its monomer and in the quinoidal polymer. PQuBT-TV exhibited high spin characteristics observed by the strong ESR signal, a low band gap, and improved electrochemical stability. On the other hand, as QuT maintained a closed-shell quinoid structure, PQuT-TV exhibited high backbone coplanarity and strong intermolecular interaction, which was beneficial for charge transport and led to high hole mobility (up to 2.40 cm2 V-1 s-1) in organic field-effect transistors. This work successfully demonstrated how the control of the closed/open-shell character of quinoidal building blocks changes charge transport and spin properties of quinoidal conjugated polymers via quinoid-aromatic interconversion.

Background Oxidative damage to retinal pigment epithelial (RPE) cells contributes to the development of age-related macular degeneration, which is among the leading causes of visual loss in elderly people. In the present study, we evaluated the protective role of triphenylphosphonium (TPP)-Niacin against hydrogen peroxide (H2O2)-induced oxidative stress in RPE cells. Methods The cellular viability, lactate dehydrogenase release, reactive oxygen species (ROS) generation, and mitochondrial function of retinal ARPE-19 cells were determined under treatment with H2O2 or pre-treatment with TPP-Niacin. The expression level of mitochondrial related genes and some transcription factors were assessed using real-time polymerase chain reaction (RT-qPCR). Results TPP-Niacin significantly improved cell viability, reduced ROS generation, and increased the antioxidant enzymes in H2O2-treated ARPE-19 cells. Mitochondrial dysfunction from the H2O2-induced oxidative stress was also considerably diminished by TPP-Niacin treatment, along with reduction of the mitochondrial membrane potential (MMP) and upregulation of the mitochondrial-associated gene. In addition, TPP-Niacin markedly enhanced the expression of transcription factors (PGC-1α and NRF2) and antioxidant-associated genes (especially HO-1 and NQO-1). Conclusion We verified the protective effect of TPP-Niacin against H2O2-induced oxidative stress in RPE cells. TPP-Niacin is believed to protect against mitochondrial dysfunction by upregulating antioxidant-related genes, such as PGC-1α, NRF2, HO-1, and NQO-1, in RPE cells.

Since quinoidal molecules have double-bond linkages between aromatic rings, they have many advantages for efficient charge transport resulting from high planarity and extended π-conjugation length. However, they unavoidably generate some isomers, which cause difficulty in purification and characterization. In this study, sulfur–oxygen conformation locking and steric repulsion approach is introduced to manipulate syn- and anti-isomerization of a quinoidal building block (bis-QEDOT). As a result, isomer-free bis-QEDOT is synthesized by introducing the 3,4-ethylenedioxy group, and the geometrical structure of bis-QEDOT is identified by thin-layer chromatography, 1H NMR, and density functional theory calculation. Furthermore, thiophene (T), bithiophene (2T), and thienylene vinylene (TV) as π-conjugated building blocks are polymerized with bis-QEDOT. Due to the quinoid structure, PQEDOT-T, PQEDOT-2T, and PQEDOT-TV show an intensified near-IR absorption and a low band gap around ∼1.16 eV. Grazing incidence wide-angle X-ray diffraction reveals that three quinoidal polymers show in the (h00) diffraction peaks up to third order after thermal annealing at 250 °C, demonstrating high crystallinity of the films. Finally, the electrical properties of the three polymers are investigated as an active layer in organic field-effect transistors showing hole mobilities of 4.3 × 10–2 (PQEDOT-T), 1.8 × 10–2 (PQEDOT-2T), and 7.8 × 10–3 cm2 V–1 s–1 (PQEDOT-TV).

Despite significant progress in organic photovoltaics (OPVs), efforts to fabricate the small-molecule OPVs by scalable printing methods have hardly been devoted. Herein, we demonstrate large-area p...

In this study, strong electron-withdrawing fluorine (F) and cyano (CN) substituents are selectively incorporated into the quinoxaline unit of two-dimensional (2D) D–A-type polymers to investigate their effects on the photovoltaic properties of the polymers. To construct the 2D polymeric structure, electron-donating benzodithiophene and methoxy-substituted triphenylamine are directly linked to the horizontal and vertical directions of the quinoxaline acceptor, respectively. After analyzing the structural, optical, and electrochemical properties of the resultant F- and CN-substituted polymers, labeled as PBCl-MTQF and PBCl-MTQCN, respectively, inverted-type polymer solar cells with a non-fullerene Y6 acceptor are fabricated to investigate the photovoltaic performances of the polymers. It is discovered that the maximum power conversion efficiency of PBCl-MTQF is 7.48%, whereas that of PBCl-MTQCN is limited to 3.10%. This significantly reduced PCE of the device based on PBCl-MTQCN is ascribed to the formation of irregular, large aggregates in the active layer, which can readily aggravate the charge recombination and charge transport kinetics of the device. Therefore, the photovoltaic performance of 2D quinoxaline-based D–A-type polymers is significantly affected by the type of electron-withdrawing substituent.

In this study, we obtained a new structural insight into the charge-transporting properties in TPD-based polymers that cannot be solely explained in terms of the type of orientation. We synthesized...

The chlorinated isoindigo (CI) is a promising building block for organic semiconducting materials because the favorable properties, such as ready availability, lower price, and higher capability to hold the electron density than fluorine atoms, make them advantageous for use in semiconducting materials. It was reported that CI can be more readily synthesized than fluorinated isoindigo (FI), and the CI-based conjugated polymer exhibited comparable device performance with the FI-based conjugated polymer. Chorine-substituted conjugated molecules, however, have been less investigated than that of the fluorine atom, presumably, due to the large size of the chlorine atom, which induces steric hindrance effects in the conjugated backbone. In this study, we systematically investigate the effect of the structural property, flexibility vs rigidity, of the donor unit on the crystallinity and charge transport characteristics of chlorinated isoindigo acceptor-based D-A-type conjugated polymers to understanding the str...

Melonoside B (1) and melonosins B (2) and A (3), new lipids based on polyoxygenated fatty acid amides, and known melonoside A (4) were isolated from two different collections of the marine sponge Melonanchora kobjakovae. The structures of these compounds, including their absolute configurations, were established using detailed analysis of 1D and 2D NMR, ECD, and mass spectra as well as chemical transformations. Melonosins 2 and 3 inhibit AP-1- and NF-kB-dependent transcriptional activities in JB6 Cl41 cells at noncytotoxic concentrations, demonstrating potential cancer preventive activity.

Retinal pigment epithelium (RPE) cell dysfunction caused by excessive oxidative damage is partly involved in age-related macular degeneration, which is among the leading causes of visual impairment in elderly people. Here, we investigated the protective role of chrysoeriol against hydrogen peroxide (H2O2)-induced oxidative stress in RPE cells. The cellular viability, reactive oxygen species (ROS) generation, and mitochondrial function of retinal ARPE-19 cells were monitored under oxidative stress or pre-treatment with chrysoeriol. The expression levels of mitochondrial-related genes and associated transcription factors were assessed using reverse transcription&ndash, quantitative polymerase chain reaction (RT-qPCR). Moreover, the protein expression of antioxidant signal molecules was characterized by Western blot analysis. Chrysoeriol significantly increased cell viability, reduced ROS generation, and increased the occurrence of antioxidant molecules in H2O2-treated ARPE-19 cells. Additionally, mitochondrial dysfunction caused by H2O2-induced oxidative stress was also considerably diminished by chrysoeriol treatment, which reduced the mitochondrial membrane potential (MMP) and upregulated mitochondrial-associated genes and proteins. Chrysoeriol also markedly enhanced key transcription factors (Nrf2) and antioxidant-associated genes (particularly HO-1 and NQO-1). Therefore, our study confirms the protective effect of chrysoeriol against H2O2-induced oxidative stress in RPE cells, thus confirming that it may prevent mitochondrial dysfunction by upregulating antioxidant-related molecules.

The morphology of conjugated polymer thin films, determined by the kinetics of film drying, is closely correlated with their electrical properties. Herein, we focused on dramatic changes in the thin-film morphology of blade-coated poly­{[N,N′-bis­(2-octyldodecyl)-naphthalene-1,4,5,8-bis­(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)} caused by the effect of solvent and coating temperature. Through in situ measurements, the evolution of polymer aggregates and crystallites, which plays a decisive role in the formation of the charge-transport pathway, was observed in real time. By combining in situ ultraviolet–visible spectroscopy and in situ grazing-incidence wide-angle X-ray scattering analysis, we could identify five distinct stages during the blade-coating process; these stages were observed irrespective of the solvent and coating temperature used. The five stages are described in detail with a proposed model of film formation. This insight is an important step in understanding the relationship between the morphology of thin polymer films and their charge-transport properties as well as in optimizing the structural evolution of thin films.

Marinomonas primoryensis KMM 3633T, extreme living marine bacterium was isolated from a sample of coastal sea ice in the Amursky Bay near Vladivostok, Russia. The goal of our investigation is to study outer membrane channels determining cell permeability. Porin from M. primoryensis KMM 3633T (MpOmp) has been isolated and characterized. Amino acid analysis and whole genome sequencing were the sources of amino acid data of porin, identified as Porin_4 according to the conservative domain searching. The amino acid composition of MpOmp distinguished by high content of acidic amino acids and low content of sulfur-containing amino acids, but there are no tryptophan residues in its molecule. The native MpOmp existed as a trimer. The reconstitution of MpOmp into black lipid membranes demonstrated its ability to form ion channels whose conductivity depends on the electrolyte concentration. The spatial structure of MpOmp had features typical for the classical gram-negative porins. However, the oligomeric structure of isolated MpOmp was distinguished by very low stability: heat-modified monomer was already observed at 30 &deg, C. The data obtained suggest the stabilizing role of lipids in the natural membrane of marine bacteria in the formation of the oligomeric structure of porin.

Six new carotane sesquiterpenoids piltunines A&ndash, F (1&ndash, 6) together with known compounds (7&ndash, 9) were isolated from the marine-derived fungus Penicillium piltunense KMM 4668. Their structures were established using spectroscopic methods. The absolute configurations of 1&ndash, 7 were determined based on circular dichroism (CD) and nuclear Overhauser spectroscopy (NOESY) data as well as biogenetic considerations. The cytotoxic activity of some of the isolated compounds and their effects on regulation of reactive oxygen species (ROS) and nitric oxide (NO) production in lipopolysaccharide-stimulated macrophages were examined.

Controlling the morphology of conjugated polymer film through careful selection of solvent is very important for facilitating charge transport in organic opto-electrical and electrical devices. In this report, we systematically study on a selection rule for optimum solvent choice to achieve highly aligned conjugated polymer chains with large ordered domain sizes for high performance organic field-effect transistors (OFETs) through various experimental analysis and Hansen solubility parameters. Three parameters: boiling point, solubility, and molecular interaction between conjugated polymer and solvents, are the most important to obtain optimum morphology. Similar molecular interaction values between solvent and conjugated polymer determined the formation of larger size ordered domain in films. High boiling point and relatively poor solubility solvents affect anisotropic film formation of conjugated polymer chains during off-center spin-coating. Considering these, large ordered domains with highly aligned diketopyrrolopyrrole thieno[3,2-b]thiophene (DPPT-TT) polymer chains were achieved by these important factors, and we demonstrate impressively high field-effect mobility ∼5.89 cm2 V−1 s−1 with low standard deviation (13%), which is the highest reported value so far for top-gate/bottom-contact DPPT-TT OFETs.

The demand for high-purity semiconducting single-walled carbon nanotubes (sc-SWNTs) has increased considerably with the aim of utilizing their superior properties in a range of future applications. Among post-sorting methods, conjugated polymers have been regarded as one of the candidates to selectively isolate sc-SWNTs with uniform electrical properties. Herein, we demonstrate the ability to selectively sort two types of SWNTs by the two polymers PCTV18T and PC12TV18T, which have different alkyl side-chain densities. PC12TV18T, with a high alkyl chain density, shows great sorting ability for both high-pressure carbon monoxide and plasma-torch-grown SWNTs with a weight ratio of almost 1:1 in toluene solution. In addition, it is found that PC12TV18T selectively sorts sc-SWNTs with the high purity. The chirality and diameters of the enriched sc-SWNTs are further confirmed by Raman spectroscopy and photoluminescence excitation/emission mapping. Finally, we fabricate bottom gate/bottom contact thin-film transistors using the enriched sc-SWNTs as semiconductors to verify the electrical performance. Devices with well-percolated sc-SWNT networks displayed p -dominant properties with average charge-carrier mobilities of 2.05 cm 2 V −1 S −1 and 9.87 cm 2 V −1 S −1 and on/off current ratios of approximately 10 4 and 10 5 for high-pressure carbon monoxide and plasma-torch-grown SWNTs, respectively.

Fluorine (F) substitution on conjugated polymers in polymer solar cells (PSCs) has a diverse effect on molecular properties and device performance. We present a series of three D-A type conjugated polymers (PBT, PFBT, and PDFBT) based on dithienothiophene and benzothiadiazole units with different numbers of F atoms to explain the influence of F substitution by comparing the molecular interactions of the polymers and the recombination kinetics in PSCs. The preaggregation behavior of PFBT and PDFBT in o-DCB at the UV–vis absorption spectra proves that both polymers have strong intermolecular interactions. Besides, more closely packed structures and change into face-on orientation of fluorinated polymers are observed in polymer:PC71BM blends by GIXD which is beneficial for charge transport and, ultimately, for current density in PSCs (4.3, 13.0, and 14.5 mA cm–2 for PBT, PFBT, and PDFBT, respectively). Also, the introduction of F atoms on conjugated backbones affects the recombination kinetics by suppressing...

A series of D-A type conjugated polymers based on (E)-1,2-bis(3-dodecyllthiophen-2-yl)ethene (TV) as electron donor unit and with different repeating subunits, PTVBO8 , PTVBT8 , PTVTBO12 , and PTVTBT12 were synthesized for use in organic field effect transistors and bulk heterojunction organic photovoltaics. Upon incorporation of alkoxy substituents in acceptor units, benzooxadiazole (BO) and benzothiadiazole (BT), polymer solubility improved and higher molecular weight polymers were obtained. In addition, all copolymers showed favorable thermal stability (T d > 300 °C), and low band gap properties (1.49–1.67 eV). The thiophene-flanked TV-TBX copolymers, PTVTBO12 and PTVTBT12, exhibited higher molecular weight and superior device performance in both OFETs and OPVs compared with the TV-BX copolymers. The electronic energy levels of copolymers were strongly influenced by the nature of acceptor units, while optical band gaps and shape of molecular orientation of polymer chains were affected by the presence or absence of thiophene spacer. Charge carrier mobilities in TV-TBX copolymers were 1 order of magnitude greater than in TV-BX copolymers. OFETs based on a PTVTBT12 with TG/BC configuration displayed the highest hole mobility of 0.48 cm 2 V −1 s −1 . The photovoltaic device containing a PTVTBO12 :PC 71 BM (1:2 w/w) blend system exhibited best performance with a V oc of 0.56 V, a short-circuit current density (Jsc) of 13.1 mA cm −2 , a fill factor (FF) of 69%, and a power conversion efficiency (PCE) of 5.0%.

A series of low band gap conjugated copolymers containing 9,10-modified phenanthrene and diketopyrrolopyrrole (DPP) units were synthesized as electron donor materials for bulk heterojunction organic solar cells. These donor-acceptor type PDPP copolymers have varying solubilizing groups on their identical conjugated backbones. The optical bandgap of PDPP copolymers is about 1.6 eV which corresponds to the long wavelength region of the solar spectrum. Through the incorporation of phenanthrene units into the conjugated backbone instead of commonly used thiophene derivatives, a higher open-circuit voltage of about 0.8 V could be achieved, as a result of their deeper HOMO level. Of all the devices, the P4:PC61BM BHJ system showed the best performance with a Voc of 0.79 V, a Jsc of 5.97 mA cm−2, a fill factor of 0.62 and a power conversion efficiency of 2.73% due to superior nanoscale phase separation between the electron donor and electron acceptor materials than in the other polymers arising from short-branched solubilizing groups on the phenanthrene side of its conjugated backbone.

We report on the fabrication of an organic thin-film semiconductor formed using a blend solution of soluble ambipolar small molecules and an insulating polymer binder that exhibits vertical phase separation and uniform film formation. The semiconductor thin films are produced in a single step from a mixture containing a small molecular semiconductor, namely, quinoidal biselenophene (QBS), and a binder polymer, namely, poly(2-vinylnaphthalene) (PVN). Organic field-effect transistors (OFETs) based on QBS/PVN blend semiconductor are then assembled using top-gate/bottom-contact device configuration, which achieve almost four times higher mobility than the neat QBS semiconductor. Depth profile via secondary ion mass spectrometry and atomic force microscopy images indicate that the QBS domains in the films made from the blend are evenly distributed with a smooth morphology at the bottom of the PVN layer. Bias stress test and variable-temperature measurements on QBS-based OFETs reveal that the QBS/PVN blend semiconductor remarkably reduces the number of trap sites at the gate dielectric/semiconductor interface and the activation energy in the transistor channel. This work provides a one-step solution processing technique, which makes use of soluble ambipolar small molecules to form a thin-film semiconductor for application in high-performance OFETs.

Two donor-acceptor (D-A) alternating conjugated polymers based on thienylenevinylene-benzotriazole (TV-BTz), PTV6B with a linear side chain and PTVEhB with a branched side chain, were synthesized and characterized for organic field effect transistors (OFETs) and complementary metal-oxide-semiconductor (CMOS)-like inverters. According to density functional theory (DFT), polymers based on TV-BTz exhibit a coplanar and rigid structure with no significant twists, which could cause to an increase in charge-carrier mobility in OFETs. Alternating alkyl side chains of the polymers impacted neither the band gap nor the energy level. However, it significantly affected the morphology and crystallinity when the polymer films were thermally annealed. To investigate the effect of thermal annealing on the morphology and crystallinity, we characterized the polymer films using atomic force microscopy (AFM) and 2D-grazing incidence X-ray diffraction (2D-GIWAXD). Fibrillary morphologies with larger domains and increased crystallinity were observed in the polymer films after thermal annealing. These polymers exhibited improved charge-carrier mobilities in annealed films at 200 °C and demonstrated optimal OFET device performance with p-type transport characteristics with charge-carrier mobilities of 1.51 cm

An attractive synthetic strategy for incorporating a quinoidal molecule into a conjugated polymer backbone with three short steps is reported here. The quinoidal polymer, PQuBTV, exhibited high planarity and extended conjugation. As a result, ambipolar charge carrier mobilities of 0.52 cm2 V−1 s−1 for holes and 0.53 cm2 V−1 s−1 for electrons were observed in field-effect transistor devices.

In article number 1900245, Martin Heeney, Dong‐Yu Kim, and co‐workers describe an organic field‐effect transistor featuring a semiconducting polymer, PDSSTV, in its channel layer. The newly developed unit of three‐fused selenophenes enables the polymer to have a strong intermolecular interaction caused by large and polarizable orbitals of selenium. The PDSSTV demonstrates its maximum hole mobility of 2.1 cm2 V−1 s−1 at a low operating voltage, –30 V.

KGaA, Weinheim The synthesis of a diseleno[3,2-b:2′,3′-d]selenophene (DSS) composed of three fused selenophenes is reported and it is used as a building block for the preparation of a high hole mobility conjugated polymer (PDSSTV). The polymer demonstrates strong intermolecular interactions even in solution, despite steric repulsion between the large Se atom in DSS and adjacent (C β )–H atoms which leads to a partially twisted confirmation PDSSTV. Nevertheless, 2D grazing incidence X-ray diffraction (2D-GIXD) analysis reveals that the polymer tends to align in a highly ordered edge-on orientation after thermal annealing. The polymer demonstrates promising performance in a field-effect transistor device with saturated hole mobility up to 2 cm 2 V −1 s −1 obtained under relatively low gate voltages of −30 V. The ultilization of a Se-containing fused aromatic system, therefore, appears to be a promising avenue for the development of high-performance conjugated polymers.

Peptide hormones perceived in the cell surface via receptor proteins enable cell-to-cell communication and act in multiple biological processes through the activation of intracellular signaling. Even though Arabidopsis is predicted to have more than 1,000 secreted peptides, the biological relevance of the majority of these is yet to be established. Here, we demonstrate that PLANT NATRIURETIC PEPTIDE A (PNP-A), a functional analog to vertebrate atrial natriuretic peptides, antagonizes the salicylic acid (SA)-mediated cell death in the Arabidopsis lesion-stimulating disease 1 (lsd1) mutant. While loss of PNP-A potentiates SA signaling, exogenous application of the PNP-A synthetic peptide or overexpression of PNP-A significantly compromises the SA-mediated cell death. Moreover, we identified a plasma membrane-localized receptor-like protein, which we name PNPAR (for PNP-A receptor), that binds PNP-A and is required to counteract SA responses. Our work identifies a novel peptide-receptor pair which modulates SA responses in Arabidopsis.

We report the effect of binary additives on the fabrication of polymer solar cells (PSCs) based on a bulk heterojunction (BHJ) system. The combination of 1,8-diiodooctane (DIO), a high-boiling and selective solvent, for fullerene derivatives and poly(dimethylsiloxane) (PDMS) precursor, a nonvolatile insulating additive, affords complementary functions on the effective modulation of BHJ morphology. It was found that DIO and PDMS precursor each play different roles in the control of BHJ morphology, and thus, the power conversion efficiency (PCE) can be further enhanced to 7.6% by improving the fill factor (FF) from 6.8% compared to that achieved using a conventional device employing only a DIO additive. In the BHJ of the active layer, DIO suppressed the large phase separation of PBDTTT-CF and PC71BM while allowing the formation of continuous polymer networks in the donor polymer through phase separation of the PDMS precursor and BHJ components. The appropriate amount of PDMS precursor does not disturb charg...

A bimodal texturing effect of semiconducting polymers is investigated by incorporating conjugated small molecules to significantly improve the charge transport characteristics via formation of 3D transport pathways. Solution blending of the electron-transporting polymer, poly{[N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)} (P(NDI2OD-T2)), with small molecular crystals of tetrathiafulvalene and tetracyanoquinodimethane is used, and the thin film microstructures are studied using a combination of atomic force microscopy, transmission electron microscopy, 2D grazing incidence X-ray diffraction, and surface-sensitive near-edge X-ray absorption fine structure. Blended thin films show edge-on and face-on bimodal texture with long-range order and microstructure packing orientation preferable for electron transport through the channel in organic field-effect transistors, which is confirmed by high electron mobility 1.91 cm2 V−1 s−1, small contact resistance, and low energetic disorder according to temperature dependence of the field-effect mobility. Structural changes suggest a 3D network charge transport model via lamella packing and bimodal orientation of the semiconducting polymers.

The pldA gene encoding membrane-bound phospholipase A1 of Yersinia pseudotuberculosis was cloned and expressed in Escherichia coli cells. Recombinant phospholipase A1 (rPldA) was isolated from inclusion bodies dissolved in 8 M urea by two-stage chromatography (ion-exchange and gel-filtration chromatography) as an inactive monomer. The molecular mass of the rPldA determined by MALDI-TOF MS was 31.7 ± 0.4 kDa. The highly purified rPldA was refolded by 10-fold dilution with buffer containing 10 mM Triton X-100 and subsequent incubation at room temperature for 16 h. The refolded rPldA hydrolyzed 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine in the presence of calcium ions. The enzyme exhibited maximal activity at 37°C and nearly 40% of maximal activity at 15°C. The phospholipase A1 was active over a wide range of pH from 4 to 11, exhibiting maximal activity at pH 10. Spatial structure models of the monomer and the dimer of Y. pseudotuberculosis phospholipase A1 were constructed, and functionally important amino acid residues of the enzyme were determined. Structural differences between phospholipases A1 from Y. pseudotuberculosis and E. coli, which can affect the functional activity of the enzyme, were revealed.

In this report, we investigate a formation mechanism for polymer chains aligned with various semiconductor polymers and a microstructure for directionally aligned film through systematic analysis that includes polarized UV–visible–near infrared (UV–vis–NIR) absorption spectroscopy, atomic force microscopy, polarized charge modulation microscopy (p-CMM), and incident X-ray diffraction (GIXD) measurements. Through this study, we make two important observations: first, the highly aligned organic polymer semiconductor films are achieved by off-center spin coating of the preaggregated conjugated polymer solution. Second, the directionally aligned conjugated polymer films exhibit a larger anisotropy on the top surface compared with bulk film, which allows effective mobility improvement in top-gate/bottom-contact field-effect transistors with high performance uniformity. Finally, we demonstrate high-mobility organic field-effect transistors (OFETs) (7.25 cm2/(V s)) with a mobility large anisotropy (37-fold) usin...

We demonstrate that an easily accessible polyacrylonitrile (PAN) polymer can efficiently function as a novel solution-processable anode interfacial layer (AIL) to boost the device performances of polymer:fullerene-based solar cells (PSCs). The PAN thin film was simply prepared with spin-coating of a cost-efficient PAN solution dissolved in dimethylformamide on indium tin oxide (ITO), and the thin polymeric interlayer on PSC parameters and stability were systemically investigated. As a result, the cell efficiency of the PSC with PAN was remarkably enhanced compared to the device using bare ITO. Furthermore, with PAN, we finally achieved an excellent power conversion efficiency (PCE) of 6.7% and a very high PSC stability in PTB7:PC71BM systems, which constitute a highly comparable PCE and superior device lifetime relative to those of conventional PSCs with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PSS). These results demonstrate that the inexpensive solution-processed PAN polymer can be an attractivePSS alternative and is more powerful for achieving better cell performances and lower cost PSC production.

Donor–acceptor (D–A) type conjugated polymers have been developed to absorb longer wavelength light in polymer solar cells (PSCs) and to achieve a high charge carrier mobility in organic field-effect transistors (OFETs). PDTDP, containing dithienothiophene (DTT) as the electron donor and diketopyrrolopyrrole (DPP) as the electron acceptor, was synthesized by stille polycondensation in order to achieve the advantages of D–A type conjugated polymers. The polymer showed optical band gaps of 1.44 and 1.42 eV in solution and in film, respectively, and a HOMO level of 5.09 eV. PDTDP and PC71BM blends with 1,8-diiodooctane (DIO) exhibited improved performance in PSCs with a power conversion efficiency (PCE) of 4.45% under AM 1.5G irradiation. By investigating transmission electron microscopy (TEM), atomic force microscopy (AFM), and the light intensity dependence of JSC and VOC, we conclude that DIO acts as a processing additive that helps to form a nanoscale phase separation between donor and acceptor, resulting in an enhancement of μh and μe, which affects the JSC, EQE, and PCE of PSCs. The charge carrier mobilities of PDTDP in OFETs were also investigated at various annealing temperatures and the polymer exhibited the highest hole and electron mobilities of 2.53 cm2 V−1 s−1 at 250 °C and 0.36 cm2 V−1 s−1 at 310 °C, respectively. XRD and AFM results demonstrated that the thermal annealing temperature had a critical effect on the changes in the crystallinity and morphology of the polymer. The low-voltage device was fabricated using high-k dielectric, P(VDF-TrFE) and P(VDF-TrFE-CTFE), and the carrier mobility of PDTDP was reached 0.1 cm2 V−1 s−1 at Vd = −5 V. PDTDP complementary inverters were fabricated, and the high ambipolar characteristics of the polymer resulted in an output voltage gain of more than 25.

Newly synthesized donor-acceptor (D-A) type of conjugated copolymer (PCTV-BTzF) with semi-fluorinated alkyl side chains, which has good solubility in common organic solvents, is described. Unlike polymers with hydrocarbon-based alkyl side chains, semi-fluorocabonated polymer leads to intriguing results. First, the self-organization behavior of the semi-fluoroalkyl side chains by the self-aggregate propensity between hydrocarbon and fluorocarbon induces patterned microstructural morphology in polymer films; second, it dominates the molecular orientation of polymers with planar back structure. Such unusual properties of the polymer with semi-fluoroalkyl side chains compared to that with the hydrocarbon ones are verified and characterized though various systematic characterizations, including temperature-dependent UV-Vis absorption spectroscopy, atomic force microscopy, and 2D-grazing incident X-ray diffraction measurement. As a result, PCTV-BTzF-based OFETs show the maximum p-type field-effect mobility of 1.02 cm2 V-1 s-1 in the 200 °C annealed films.

We report the synthesis and optoelectronic properties of novel platinum-based polymers (p-Pt-DPP) incorporating 3,6-di-2-thienyl-2,5-dihydro-2,5-diethylhexylpyrrolo[3,4-c]pyrrole-1,4-dione. The synthesized amorphous metallated polymer exhibited long wavelength absorption in the range of 500–684 nm and a band-gap as low as 1.75 eV. Organic field-effect transistors (OFETs) fabricated from p-Pt-DPP showed hole mobility of 1.6 × 10⁻³ cm² · V⁻¹s⁻¹ and an on/off ratio of 5 × 10⁴. In addition, polymer solar cells (PSCs) based on p-Pt-DPP and PC₇₁BM exhibited a photovoltaic efficiency of 1.22% under AM 1.5 G conditions with an illumination of 100 mW·cm−2 without any annealing process.

Seven eremophilane-type sesquiterpene glucosides, alticolosides A–G, have been isolated from aerial parts of the endemic Far Eastern species Ligularia alticola Worosch. (Family Asteraceae) along with two known compounds, monoterpenoid glycoside (4S)-α-terpineol 8-O-β- d -glucopyranoside and norditerpenoid glycoside 7(8)-dihydro-β-ionone 3-O-β- d -glucopyranoside. Alticoloside D was identified with the earlier known 8-O-(β- d -glucopyranosyl)-2-oxo-eremophila-1(10),8,11-triene, but the stereostructure of the latter was revised on the basis of ROESY and CD data. All the glycosides are derivatives of new eremophilane-type aglycones, differing from known eremophilanes in details of planar and/or stereo structures except for the aglycone of alticoloside E.

Background: Cordyceps militaris is one of well-known medicinal mushrooms with anti-inflammatory, anti-cancer, anti-diabetic, and anti-obesity activities. Objective: The objective of the following study is to isolate chemical components from the ethanol extract (Cm-EE) from Cordyceps militaris and to evaluate their anti-inflammatory activities. Materials and Methods: Column chromatographic separation was performed and anti-inflammatory roles of these compounds were also examined by using NO production and protein kinase B (AKT) activity assays. Results: From Cm-EE, 13 constituents, including trehalose (1), cordycepin (2), 6-hydroxyethyladenosine (3), nicotinic amide (4), butyric acid (5), β-dimorphecolic acid (6), α-dimorphecolic acid (7), palmitic acid (8), linoleic acid (9), cordycepeptide A (10), 4-(2-hydroxy-3-((9E,12E)-octadeca-9,12-dienoyloxy)propoxy)-2-(trimethylammonio)butanoate (11), 4-(2-hydroxy-3-(palmitoyloxy)propoxy)-2-(trimethylammonio)butanoate (12), and linoleic acid methyl ester (13) were isolated. Of these components, compound 2 displayed a significant inhibitory effect on NO production in lipopolysaccharide (LPS)-activated RAW264.7 cells. Furthermore, this compound strongly and directly suppressed the kinase activity of AKT, an essential signalling enzyme in LPS-induced NO production, by interacting with its ATP binding site. Conclusion: C. militaris could have anti-inflammatory activity mediated by cordycepin-induced suppression of AKT.

We report the various conformational structures of long pendant side-chains, and the effects of thermal and solvent vapor annealing (SVA) with the corresponding charge carrier mobilities of thiophene-based conjugated polymers, poly[5,5′-bis(3-dodecyl-2-thienyl)-2,2′-bithiophene] (PQT-12) and poly(4,4′-bis-decyloxymethylquaterthiophene) (POQT), by correlated study of their extraordinary polymorphic crystal structures. In substitution for alkyl chains in polythiophenes, ether alkyl chains induce a favorable non-covalent interaction between the oxygen and sulfur atoms and help the polymer chains planar with lower torsion angles between conjugated backbone units showing a reduced π–π stacking distance. However, the flexibility and conformational freedom with such long side-chains dominantly induce polymorphic crystallites from bent and extended side-chains. Especially, POQT exhibit two polymorphic crystallite phases in a similar ratio probably due to the increased freedom of ether alkyl chains. Therefore, the field effect mobility of POQT is decreased gradually with the increase of annealing temperature from 0.024 (at 80 °C) to 3.96 × 10−4 cm2/V s (at 170 °C). Contrary to the thermal annealing method, solvent-vapor-annealed POQT films show highly ordered and single-phase crystallites with edge-on orientation to the substrate, which ultimately provides an effectively improved charge carrier mobility from 0.023 (pristine) to 0.076 cm2/V s after adequate solvent vapor exposure.

This paper investigates the effects of side chains, which are important structural constituents, on the characteristics of organic resistive memory devices with water-soluble polyfluorene (WPF) derivatives. The WPF derivatives have either an ethylene oxide (EO) or an alkyl side chain the lengths of the EO side chains are 2, 4, or 6 molecules. WPFs exhibit typical bipolar switching behaviors with reliable non-volatile characteristics and good device-to-device uniformity under ambient conditions. WPFs with the EO side chains showed better memory characteristics than those of the alkyl side chains of similar length. In addition, as the EO unit lengthened, the ON/OFF ratio of the memory device gradually increased from 5 × 10 2 to 10 5 , and the threshold voltage ( V th ) progressively decreased from 4 to 3.5 V. The retention times for WPF-hexyl, WPF-2O, WPF-4O, and WPF-6O are 10 4 , 200, 10 4 , and 10 4 s, respectively. The excellent switching properties of WPF-4O and WPF-6O are believed to be mainly attributed to highly localized current pathways and the low trap density.

A r-GO with sulfonic acid groups (sr-GO) was newly developed and it showed dramatically concentrated aqueous dispersions with high film conductivity. With the aid of sulfonic acid groups, good compatibility with various HOMO materials was achieved, resulting in PCEs over 7% for sr-GO-based cells with superior device stability to PEDOT:PSS-based devices.

A study has been conducted on the electrodeposition of tantalum in a 61mol% LiF–39mol% NaF melt containing 1mol% K2TaF7 at 800°C. Tantalum was coated onto a stainless-steel base (SUS316L) by molten salt electrodeposition (MSE) at different current densities (0.5, 1.5, 2, 5, 10, 20mA/cm2). Electrodeposition of metallic tantalum occurred primarily by electroreduction of Ta(V), i.e. TaF72−, at a potential of

The aim of this study was to determine and compare the preventive effect of Korean White Ginseng and Red Ginseng on oxidative stress in H2O2-treated HepG2 cells. The roots of ginseng were extracted with 70% methanol and partitioned with butanol to obtain saponin fractions, which have been known as bioactive constituents of ginseng. 2′,7′-Dichlorofluorescein diacetate (DCF-DA) assay and malondialdehyde (MDA) content were measured for evaluating intracellular reactive oxygen species (ROS) generation. Also, mRNA expressions and activities of antioxidant enzymes were analyzed to determine the antioxidant activity of saponin or non-saponin fractions of ginsengs. According to DCF-DA assay, H2O2-induced MDA release and ROS generation were significantly reduced by treatment with saponin fractions of white and red ginseng roots. Also, saponin fractions increased effectively intracellular antioxidant enzyme activities including catalase, glutathione peroxidase and superoxide dismutase in H2O2- treated HepG2 hepatoma cells. In general, red ginseng was more effective than white ginseng for reducing oxidative stress. These results indicate that administration of red ginseng may certainly contribute relatively stronger than white ginseng to prevent from damaging liver function by oxidative stress.

We report a method for controlling the orientations of conjugated polymers in the active layer of organic thin-film transistors (OTFTs) by annealing the film at the melting temperature in a vertically aligned multiwalled carbon nanotube (VA-CNT) template under various load pressures. Poly(3-hexylthiophene) [P3HT] molecules are effectively aligned in the melting state annealing at 240 °C for 30 min, as a result of intermolecular π-π and CH3-π interactions between the polymer and the VA-CNTs, which are separated from the conjugated polymer film after cooling to room temperature. In-plane and out-of-plane X-ray diffraction results show that the melt-annealed P3HT film with VA-CNTs has better crystallite ordering than a pristine 80 °C baked film and a melt-annealed film without VA-CNTs, and a larger number of crystallites in the treated P3HT film are oriented in the [100] direction, which is normal to the substrate. When we used the melt-aligned P3HT film with VA-CNTs as the active layer in OTFTs, the P3HT OTFT exhibits a better field-effect mobility value of 0.12 cm(2)/(V s) than a simply melt-annealed device without VA-CNTs [0.06 cm(2)/(V s)].

SFA-PQT exhibits self-assembly via a fluorophobic effect in a non-fluorous solvent, which leads to an enhanced electrical performance. Ambipolar transistors and inverters with p- and n- type bilayers are enabled by the unique thermally reversible soluble-insoluble properties of SFA-PQT. More importantly, the hydrophobicity of SFA-PQT facilitates orthogonal hydrophobic patterning and a patterned inverter exhibits low voltage dissipation, a narrow transition zone, a high gain value, and negligible hysteresis.

Poly(p-phenylene vinylene) (PPV) derivatives with 2,5-diphenyl-1,3,4-oxadiazole-diyl (OXD) as the side chain, poly[2-{4-[5-(4-(heptyloxy)phenyl)-1,3,4-oxadiazole-2-yI]phenyl-oxy}-1,4-phenylene-vinylene] (OXH-PPV), poly[2-{4-[5-(4-(heptyloxy)phenyl)-1,3,4-oxadia-zole-2-yl]phenyl-oxy}-1,4-phenylenevinylene-co-2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (OXH-PPV-co-MEH-PPV), and poly[2-methoxy-5-(2'-ethylhexyl-oxy)-p-phenylene vinylene] (MEH-PPV), were synthesized via a modified Gilch route. The electron-deficient oxadiazole moiety was introduced on the side chain of the polymer backbone to increase the electron-affinity of the polymers. The electroluminescent (EL) properties of the resulting polymers as an active layer, were investigated by the fabrication of single-layer LEDs and the devices using OXH-PPV-co-MEH-PPV showed better EL properties than those using pure MEH-PPV. Also, to investigate the switching properties of the resulting polymers as an active layer, OFET devices were fabricated in a top-contact/bottom-gate configuration. The resulting FETs exhibited typical p-channel characteristics, field-effect mobility of 6.5 x 10(-4) - 7.0 x 10(-5) cm2 V(-1) s(-1), and on-off ratio of about 10(4)-10(5).

We report the development of high-performance inkjet-printed organic field-effect transistors (OFETs) and complementary circuits using high- k polymer dielectric blends comprising poly(vinylidenefluoride-trifluoroethylene) (P(VDF-TrFE)) and poly(methyl methacrylate) (PMMA) for high-speed and low-voltage operation. Inkjet-printed p -type polymer semiconductors containing alkyl-substituted thienylenevinylene (TV) and dodecylthiophene (PC12TV12T) and n -type P(NDI2OD-T2) OFETs showed high field-effect mobilities of 0.1–0.4 cm 2 V −1 s −1 and low threshold voltages down to 5 V. These OFET properties were modified by changing the blend ratio of P(VDF-TrFE) and PMMA. The optimum blend – a 7:3 wt% mixture of P(VDF-TrFE) and PMMA – was successfully used to realize high-performance complementary inverters and ring oscillators (ROs). The complementary ROs operated at a supplied bias ( V DD ) of 5 V and showed an oscillation frequency ( f osc ) as high as ∼80 kHz at V DD = 30 V. Furthermore, the f osc of the complementary ROs was significantly affected by a variety of fundamental parameters such as the electron and hole mobilities, channel width and length, capacitance of the gate dielectrics, V DD , and the overlap capacitance in the circuit configuration.

We report the synthesis and characterization of thienylenevinylene-based donor–acceptor alternating copolymers (PTVPhI-Eh and PTVPhI-C12) as highly efficient ambipolar semiconductors in a thin film transistor. These polymers exhibit significantly improved hole and electron mobilities after thermal annealing. To determine the relationship between ambipolar charge transport and thermal annealing, we investigated these polymers using various analyses such as optical spectroscopy, Raman spectroscopy, computational quantum chemical calculation, X-ray diffraction, atomic force microscopy, and ambipolar charge mobility measurements. In pristine films, the polymer chains exhibited weak intra- and interchain ordering. However, when samples were annealed at sufficiently high temperatures, they exhibited a more ordered intra- and interchain conformation. As a result, we found a strong relationship between intra- and interchain conformational changes of the polymers and corresponding ambipolar charge transport proper...

A new cycloartane-type triterpene glycoside, agroastragaloside V (1) was isolated from the roots of Astragalus membranaceus. The structure was identified as 3-O-β-(2'-O-acetyl)-D-xylopyranosyl-6-O-β-D-glucopyranosyl-(24S)-3β,6α,24α,25-tetrahydroxy- 9,19-cyclolanostane, by means of spectroscopic methods, including HR-FAB/MS, 1D NMR (1H, 13C, DEPT), 2D NMR (gCOSY, gHSQC, gHMBC, NOESY), and IR spectroscopy. Four known cycloartane glycosides, namely, agroastragaloside I (2), agroastragaloside II (3), isoastragaloside II (4) and astragaloside IV (5) were also isolated. All isolated compounds were tested for the ability to inhibit LPS-induced nitric oxide production in RAW264.7 macrophages.

A new lignan, named acanthosessilin A (1), as well as eight known lignan and lignan glycosides 2-9 were isolated from an ethanolic extract of Acanthopanax sessiliflorus fruits. The chemical structures were determined by spectroscopic methods, including HR-EIMS, 1D NMR (1H, 13C, DEPT), 2D NMR (gCOSY, gHSQC, gHMBC, NOESY), and IR spectroscopy. All isolated compounds were tested for the ability to inhibit LPS-induced nitric oxide production in RAW264.7 macrophages.

We report a spray deposition technique as a screening tool for solution processed solar cells. A dual-feed spray nozzle is introduced to deposit donor and acceptor materials separately and to form blended films on substrates in situ. Using a differential pump system with a motorised spray nozzle, the effect of film thickness, solution flow rates and the blend ratio of donor and acceptor materials on device performance can be found in a single experiment. Using this method, polymer solar cells based on poly(3-hexylthiophene) (P3HT):(6,6)-phenyl C61 butyric acid methyl ester (PC61BM) are fabricated with numerous combinations of thicknesses and blend ratios. Results obtained from this technique show that the optimum ratio of materials is consistent with previously reported values confirming this technique is a very useful and effective screening method. This high throughput screening method is also used in a single-feed configuration. In the single-feed mode, methylammonium iodide solution is deposited on lead iodide films to create a photoactive layer of perovskite solar cells. Devices featuring a perovskite layer fabricated by this spray process demonstrated a power conversion efficiencies of up to 7.9%.