137 research outputs found

    Enhanced Hole Transport in Ternary Blend Polymer Solar Cells

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    Recently, ternary blend polymer solar cells have attracted great attention to improve a short‐circuit current density (JSC) effectively, because complementary absorption bands can harvest the solar light over a wide wavelength range from visible to near‐IR region. Interestingly, some ternary blend solar cells have shown improvements not only in JSC but also in fill factor (FF). Previously, we also reported that a ternary blend solar cell based on a low‐bandgap polymer (PTB7‐Th), a wide‐bandgap polymer (PDCBT), and a fullerene derivative (PCBM) exhibited a higher FF than their binary analogues. Herein, we study charge transport in PTB7‐Th/PDCBT/PCBM ternary blend films to address the origin of the improvement in FF. We found that hole polarons are located in PTB7‐Th domains and their mobility is enhanced in the ternary blend film

    Enhanced Charge Transport in a Conjugated Polymer Blended with an Insulating Polymer

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    Herein, the hole transport in a quinoxaline–thiophene based conjugated polymer (PTQ1) mixed with an insulating polystyrene (PS) was studied by macroscopic and local current density−voltage characteristics measurements. As a result, we found that the hole conductivity in PTQ1 : PS blends increases as the weight ratio of PTQ1 is reduced down to 20 wt%. This is mainly ascribed to increases in mobility because the charge carrier density would be constant in the insulating PS matrix. With decreasing PTQ1 weight ratio in the blends, the absorption bandwidth of PTQ1 and additional emission due to excimer decreased, suggesting that interchain interactions are suppressed. By measuring the temperature‐dependent conductivity, we also found that the activation energy for the hole conductivity is smaller in PTQ1 : PS blends than in PTQ1 neat films. These findings suggest that trap sites decrease because of the suppressed interaction between PTQ1 chains in blend films. We also measured conductive atomic force microscope images of the blend films to clarify the local conductive property. For PTQ1 neat films, a low conductive image was observed over the entire film. For PTQ1 : PS blends, on the other hand, many highly conductive spots were locally found. We thus conclude that the dilution of PTQ1 chains in the PS matrix leads to a lower formation of trap sites, resulting in more conductive transport in PTQ1 : PS blends than in PTQ1 neat films

    Molecular mechanism of the recognition of bacterially cleaved immunoglobulin by the immune regulatory receptor LILRA2

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    金沢大学医薬保健研究域薬学系Human leukocyte immunoglobulin-like receptors (LILRs) typically regulate immune activation by binding to the human leukocyte antigen class I molecules. LILRA2, a member of the LILR family, was recently reported to bind to other unique ligands, the bacterially degraded Igs (N-truncated Igs), for the activation of immune cells. Therefore, LILRA2 is currently attracting significant attention as a novel innate immune receptor. However, the detailed recognition mechanisms required for this interaction remain unclear. In this study, using several biophysical techniques, we uncovered the molecular mechanism of N-truncated Ig recognition by LILRA2. Surface plasmon resonance analysis disclosed that LILRA2 specifically binds to N-truncated Ig with weak affinity (Kd = 4.8 mM) and fast kinetics. However, immobilized LILRA2 exhibited a significantly enhanced interaction with N-truncated Ig due to avidity effects. This suggests that cell surface-bound LILRA2 rapidly monitors and identifies bi- or multivalent abnormal N-truncated Igs through specific cross-linking to induce immune activation. Van\u27t Hoff analysis revealed that this interaction is enthalpy-driven, with a small entropy loss, and results from differential scanning calorimetry indicated the instability of the putative LILRA2-binding site, the Fab region of the N-truncated Ig. Atomic force microscopy revealed that N truncation does not cause significant structural changes in Ig. Furthermore, mutagenesis analysis identified the hydrophobic region of LILRA2 domain 2 as the N-truncated Ig-binding site, representing a novel ligand-binding site for the LILR family. These results provide detailed insights into the molecular regulation of LILR-mediated immune responses targeting ligands that have been modified by bacteria. © 2020 Yamazaki et al. Published under exclusive license by The American Society for Biochemistry and Molecular Biology, Inc

    How plasma induced oxidation, oxygenation, and de-oxygenation influences viability of skin cells

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    The effect of oxidation, oxygenation, and de-oxygenation arising from He gas jet and He plasma jet treatments on the viability of skin cells cultured in vitro has been investigated. He gas jet treatment de-oxygenated cell culture medium in a process referred to as “sparging.” He plasma jet treatments oxidized, as well as oxygenated or de-oxygenated cell culture medium oxidized, as well as oxygenated or de-oxygenated cell culture medium depending on the dissolved oxygen concentration at the time of treatment. He gas and plasma jets were shown to have beneficial or deleterious effects on skin cells depending on the concentration of dissolved oxygen and other oxidative molecules at the time of treatment. Different combinations of treatments with He gas and plasma jets can be used to modulate the concentrations of dissolved oxygen and other oxidative molecules to influence cell viability. This study highlights the importance of a priori knowledge of the concentration of dissolved oxygen at the time of plasma jet treatment, given the potential for significant impact on the biological or medical outcome. Monitoring and controlling the dynamic changes in dissolved oxygen is essential in order to develop effective strategies for the use of cold atmospheric plasma jets in biology and medicine

    First-line pembrolizumab vs chemotherapy in metastatic non-small-cell lung cancer: KEYNOTE-024 Japan subset

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    This prespecified subanalysis of the global, randomized controlled phase Ill KEYNOTE-024 study of pembrolizumab vs chemotherapy in previously untreated metastatic non-small-cell lung cancer without EGFR/ALK alterations and a programmed death-ligand 1 (PD-L1) tumor proportion score of 50% or greater evaluated clinical outcomes among patients enrolled in Japan. Treatment consisted of pembrolizumab 200 mg every 3 weeks (35 cycles) or platinum-based chemotherapy (four to six cycles). The primary end-point was progression-free survival; secondary end-points included overall survival and safety. Of 305 patients randomized in KEYNOTE-024 overall, 40 patients were enrolled in Japan (all received treatment: pembrolizumab, n = 21; chemotherapy, n = 19). The hazard ratio (HR) for progression-free survival by independent central review (data cut-off date, 10 July 2017) was 0.25 (95% confidence interval [CI], 0.10-0.64; one-sided, nominal P = .001). The HR for overall survival (data cut-off date, 15 February 2019) was 0.39 (95% CI, 0.17-0.91; one-sided, nominal P = .012). Treatment-related adverse events occurred in 21/21 (100%) pembrolizumab-treated and 18/19 (95%) chemotherapy-treated patients; eight patients (38%) and nine patients (47%), respectively, had grade 3-5 events. Immune-mediated adverse events and infusion reactions occurred in 11 patients (52%) and four patients (21%), respectively; four patients (19%) and one patient (5%), respectively, had grade 3-5 events. Consistent with results from KEYNOTE-024 overall, first-line pembrolizumab improved progression-free survival and overall survival vs chemotherapy with manageable safety among Japanese patients with metastatic non-small-cell lung cancer without EGFRIALK alterations and a PD-L1 tumor proportion score of 50% or greater

    First-line pembrolizumab vs chemotherapy in metastatic non-small-cell lung cancer: KEYNOTE-024 Japan subset

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    This prespecified subanalysis of the global, randomized controlled phase III KEYNOTE‐024 study of pembrolizumab vs chemotherapy in previously untreated metastatic non‐small‐cell lung cancer without EGFR/ALK alterations and a programmed death ligand 1 (PD‐L1) tumor proportion score of 50% or higher evaluated clinical outcomes among patients enrolled in Japan. Treatment consisted of pembrolizumab 200 mg every 3 weeks (35 cycles) or platinum‐based chemotherapy (four to six cycles). The primary end‐point was progression‐free survival; secondary end‐points included overall survival and safety. Of 305 patients randomized in KEYNOTE‐024 overall, 40 patients were enrolled in Japan (all received treatment: pembrolizumab, n = 21; chemotherapy, n = 19). Median progression‐free survival was 41.4 (95% confidence interval [CI], 4.2‐42.5) months with pembrolizumab and 4.1 (95% CI, 2.8‐8.3) months with chemotherapy (hazard ratio [HR], 0.27 [95% CI, 0.11‐0.65]; one‐sided, nominal P = .001). Median overall survival was not reached (NR) (95% CI, 22.9‒NR) and 21.5 (95% CI, 5.2‐35.0) months, respectively (HR, 0.39 [95% CI, 0.17‐0.91]; one‐sided, nominal P = .012). Treatment‐related adverse events occurred in 21/21 (100%) pembrolizumab‐treated and 18/19 (95%) chemotherapy‐treated patients; eight patients (38%) and nine patients (47%), respectively, had grade 3‐5 events. Immune‐mediated adverse events and infusion reactions occurred in 11 pembrolizumab‐treated patients (52%) and four chemotherapy‐treated patients (21%), respectively; four patients (19%) and one patient (5%), respectively, had grade 3‐5 events. Consistent with results from KEYNOTE‐024 overall, first‐line pembrolizumab improved progression‐free survival and overall survival vs chemotherapy with manageable safety among Japanese patients with metastatic non‐small‐cell lung cancer without EGFR/ALK alterations and a PD‐L1 tumor proportion score of 50% or higher. The trial is registered with Clinicaltrials.gov: NCT02142738

    Virological characteristics of the SARS-CoV-2 Omicron BA.2.75 variant

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    SARS-CoV-2オミクロンBA.2.75株(通称ケンタウロス)のウイルス学的性状の解明. 京都大学プレスリリース. 2022-10-12.The SARS-CoV-2 Omicron BA.2.75 variant emerged in May 2022. BA.2.75 is a BA.2 descendant but is phylogenetically distinct from BA.5, the currently predominant BA.2 descendant. Here, we show that BA.2.75 has a greater effective reproduction number and different immunogenicity profile than BA.5. We determined the sensitivity of BA.2.75 to vaccinee and convalescent sera as well as a panel of clinically available antiviral drugs and antibodies. Antiviral drugs largely retained potency but antibody sensitivity varied depending on several key BA.2.75-specific substitutions. The BA.2.75 spike exhibited a profoundly higher affinity for its human receptor, ACE2. Additionally, the fusogenicity, growth efficiency in human alveolar epithelial cells, and intrinsic pathogenicity in hamsters of BA.2.75 were greater than those of BA.2. Our multilevel investigations suggest that BA.2.75 acquired virological properties independent of BA.5, and the potential risk of BA.2.75 to global health is greater than that of BA.5

    A Connexin40 Mutation Associated With a Malignant Variant of Progressive Familial Heart Block Type I

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    Background-Progressive familial heart block type I (PFHBI) is a hereditary arrhythmia characterized by progressive conduction disturbances in the His-Purkinje system. PFHBI has been linked to genes such as SCN5A that influence cardiac excitability but not to genes that influence cell-to-cell communication. Our goal was to explore whether nucleotide substitutions in genes coding for connexin proteins would associate with clinical cases of PFHBI and if so, to establish a genotype-cell phenotype correlation for that mutation. Methods and Results-We screened 156 probands with PFHBI. In addition to 12 sodium channel mutations, we found a germ line GJA5 (connexin40 [Cx40]) mutation (Q58L) in 1 family. Heterologous expression of Cx40-Q58L in connexin-deficient neuroblastoma cells resulted in marked reduction of junctional conductance (Cx40-wild type [WT], 22.2 ± 1.7 nS, n=14; Cx40-Q58L, 0.56 ± 0.34 nS, n=14; P <0.001) and diffuse localization of immunoreactive proteins in the vicinity of the plasma membrane without formation of gap junctions. Heteromeric cotransfection of Cx40-WT and Cx40-Q58L resulted in homogenous distribution of proteins in the plasma membrane rather than in membrane plaques in ̃ 50% of cells; well-defined gap junctions were observed in other cells. Junctional conductance values correlated with the distribution of gap junction plaques. Conclusions-Mutation Cx40-Q58L impairs gap junction formation at cell-cell interfaces. This is the first demonstration of a germ line mutation in a connexin gene that associates with inherited ventricular arrhythmias and emphasizes the importance of Cx40 in normal propagation in the specialized conduction system
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