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Experimental Mn and Ni K-edge X-ray absorption near-edge structure (XANES) spectra were well reproduced for 5 V-class LixNi0.5Mn1.5O4 spinels as well as 4 V-class LixMn2O4 spinels using density functional theory. Local environmental changes around the Mn or Ni centres due to differences in the locations of Li ions and/or phase transitions in the spinel oxides were found to be very important contributors to the XANES shapes, in addition to the valence states of the metal ions.
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A short period of adaptation to a prismatic shift of the visual field to the right briefly but significantly improves left unilateral spatial neglect. Additionally, prism adaptation affects multiple modalities, including processes of vision, auditory spatial attention, and sound localization. This non-randomized, single-center, controlled trial aimed to examine the immediate effects of prism adaptation on the sound-localization abilities of patients with left unilateral spatial neglect using a simple source localization test. Subjects were divided by self-allocation into a prism-adaptation group (n = 11) and a control group (n = 12). At baseline, patients with left unilateral spatial neglect showed a rightward deviation tendency in the left space. This tendency to right-sided bias in the left space was attenuated after prism adaptation. However, no changes were observed in the right space of patients with left unilateral spatial neglect after prism adaptation, or in the control group. Our results suggest that prism adaptation improves not only vision and proprioception but also auditory attention in the left space of patients with left unilateral spatial neglect. Our findings demonstrate that a single session of prism adaptation can significantly improve sound localization in patients with left unilateral spatial neglect. However, in this study, it was not possible to accurately determine whether the mechanism was a chronic change in head orientation or a readjustment of the spatial representation of the brain; thus, further studies need to be considered.
Assuntos
Adaptação Fisiológica , Orientação Espacial , Transtornos da Percepção/terapia , Localização de Som , Estimulação Acústica , Feminino , Lateralidade Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa , Projetos PilotoRESUMO
Rechargeable potassium-ion batteries have been gaining traction as not only promising low-cost alternatives to lithium-ion technology, but also as high-voltage energy storage systems. However, their development and sustainability are plagued by the lack of suitable electrode materials capable of allowing the reversible insertion of the large potassium ions. Here, exploration of the database for potassium-based materials has led us to discover potassium ion conducting layered honeycomb frameworks. They show the capability of reversible insertion of potassium ions at high voltages (~4 V for K2Ni2TeO6) in stable ionic liquids based on potassium bis(trifluorosulfonyl) imide, and exhibit remarkable ionic conductivities e.g. ~0.01 mS cm-1 at 298 K and ~40 mS cm-1 at 573 K for K2Mg2TeO6. In addition to enlisting fast potassium ion conductors that can be utilised as solid electrolytes, these layered honeycomb frameworks deliver the highest voltages amongst layered cathodes, becoming prime candidates for the advancement of high-energy density potassium-ion batteries.
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In the present study, the therapeutic potential of targeting plasminogen activator inhibitor-1 (PAI-1) in ovarian cancer was tested. Tissues samples from 154 cases of ovarian carcinoma were immunostained with anti-PAI-1 antibody, and the prognostic value was analyzed. Among the samples, 67% (104/154) showed strong PAI-1 expression; this was significantly associated with poor prognosis (progression-free survival: 20 vs. 31 months, P = 0.0033). In particular, among patients with stage II-IV serous adenocarcinoma, PAI-1 expression was an independent prognostic factor. The effect of a novel PAI-1 inhibitor, IMD-4482, on ovarian cancer cell lines was assessed and its therapeutic potential was examined using a xenograft mouse model of ovarian cancer. IMD-4482 inhibited in vitro cell adhesion to vitronectin in PAI-1-positive ovarian cancer cells, followed by the inhibition of extracellular signal-regulated kinase and focal adhesion kinase phosphorylation through dissociation of the PAI-urokinase receptor complex from integrin αVß3. IMD-4482 caused G0/G1 cell arrest and inhibited the proliferation of PAI-1-positive ovarian cancer cells. In the xenograft model, IMD-4482 significantly inhibited peritoneal dissemination with the reduction of PAI-1 expression and the inhibition of focal adhesion kinase phosphorylation. Collectively, the functional inhibition of PAI-1 significantly inhibited ovarian cancer progression, and targeting PAI-1 may be a potential therapeutic strategy in ovarian cancer.
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Plasminogen activator inhibitor (PAI)-1 is the principal inhibitor of plasminogen activators, and is responsible for the degradation of fibrin and extracellular matrix. IMD-4690 is a newly synthesized inhibitor for PAI-1, whereas the effect on allergic airway inflammation and remodeling is still unclear. We examined the in vivo effects by using a chronic allergen exposure model of bronchial asthma in mice. The model was generated by an immune challenge for 8 weeks with house dust mite antigen, Dermatophagoides pteronyssinus (Dp). IMD-4690 was intraperitoneally administered during the challenge. Lung histopathology, hyperresponsiveness and the concentrations of mediators in lung homogenates were analyzed. The amount of active PAI-1 in the lungs was increased in mice treated with Dp. Administration with IMD-4690 reduced an active/total PAI-1 ratio. IMD-4690 also reduced the number of bronchial eosinophils in accordance with the decreased expressions of Th2 cytokines in the lung homogenates. Airway remodeling was inhibited by reducing subepithelial collagen deposition, smooth muscle hypertrophy, and angiogenesis. The effects of IMD-4690 were partly mediated by the regulation of TGF-ß, HGF and matrix metalloproteinase. These results suggest that PAI-1 plays crucial roles in airway inflammation and remodeling, and IMD-4690, a specific PAI-1 inhibitor, may have therapeutic potential for patients with refractory asthma due to airway remodeling.
Assuntos
Acetatos/farmacologia , Remodelação das Vias Aéreas/efeitos dos fármacos , Asma/patologia , Asma/fisiopatologia , Compostos de Bifenilo/farmacologia , Brônquios/efeitos dos fármacos , Neovascularização Patológica/tratamento farmacológico , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Acetatos/uso terapêutico , Animais , Antígenos de Dermatophagoides/efeitos adversos , Asma/tratamento farmacológico , Asma/imunologia , Compostos de Bifenilo/uso terapêutico , Brônquios/irrigação sanguínea , Brônquios/imunologia , Brônquios/patologia , Líquido da Lavagem Broncoalveolar , Doença Crônica , Citocinas/metabolismo , Dermatophagoides pteronyssinus/imunologia , Modelos Animais de Doenças , Eosinófilos/efeitos dos fármacos , Eosinófilos/imunologia , Feminino , Imunoglobulina E/sangue , Camundongos , Ativador de Plasminogênio Tecidual/metabolismoRESUMO
BACKGROUND: Acute rejection and graft arterial disease (GAD) in cardiac transplantation limit the long-term survival of recipients; these processes are enhanced by inflammation and thrombus formation. Plasminogen activator inhibitor (PAI)-1 is critical in the inflammation and thrombus formation. However, little is known about the effect of PAI-1 in heart transplantation. Thus, the objective was to clarify the role of PAI-1 in the progression of cardiac rejection. METHODS: Murine hearts were heterotopically transplanted using major mismatch combinations for evaluation of acute rejection and class II mismatch combinations for the GAD. We administered the specific PAI-1 inhibitor (IMD-1622) into murine recipients after cardiac allografts. RESULTS: Nontreated allografts of the major mismatch group were acutely rejected, whereas the PAI-1 inhibitor prolonged their survival. Although severe cell infiltration and intimal thickening with enhancement of inflammatory factors were observed in untreated allografts of class II mismatch group on day 60, the PAI-1 inhibitor attenuated these changes. CONCLUSION: The PAI-1 inhibitor is potent for the suppression of both acute rejection and GAD.
Assuntos
Doenças Cardiovasculares/imunologia , Rejeição de Enxerto/imunologia , Transplante de Coração/imunologia , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Doença Aguda , Animais , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/prevenção & controle , Rejeição de Enxerto/metabolismo , Rejeição de Enxerto/prevenção & controle , Camundongos , Tiazolidinedionas/farmacologia , Tiazolidinedionas/uso terapêuticoRESUMO
OBJECTIVE: Plasminogen activator inhibitor (PAI)-1 plays a role in neointimal formation after percutaneous coronary intervention (PCI), the effect of overexpression or lack of PAI-1 is controversial. Murine arterial injury models develop neointimal hyperplasia similar to that observed in clinical coronary arterial restenosis after PCI. METHODS AND RESULTS: To clarify the role of PAI-1 in thrombus formation and neointimal formation after arterial injury, we used a specific PAI-1 inhibitor (IMD-1622) in a rat aorta-vein shunt model and a mouse arterial injury model. While the non-treated shunt model showed massive thrombus formation, IMD-1622 administration suppressed this. Injured arteries with vehicles showed significant neointimal formation with enhancement of adhesion molecules, fibrinogen accumulation and cell proliferation on day 28 after injury. However, intimal thickening and expression of these factors were suppressed in PAI-1 recipients. CONCLUSION: A specific PAI-1 inhibitor prevents thrombus formation and arterial neointimal formation after arterial injury. Thus, PAI-1 plays a critical role in arterial remodeling after mechanical injury. PAI-1 regulation may be useful to prevent thrombus and neointimal formation after PCI.
Assuntos
Angioplastia Coronária com Balão , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Tiazolidinedionas/farmacologia , Trombose/fisiopatologia , Túnica Íntima/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Reestenose Coronária/prevenção & controle , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/patologia , Modelos Animais de Doenças , Fibrinogênio/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Hiperplasia/prevenção & controle , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos Sprague-Dawley , Trombose/prevenção & controle , Túnica Íntima/patologiaRESUMO
Density functional theory (DFT) has been applied to study the effect of fluorination on the electronic and excited states of fused zinc oligoporphyrins in the search for new functionalizing materials, such as n-type organic semiconductors. The excitation spectra of meso-tetrafluoro, beta-octafluoro, and perfluoro zinc porphyrins, and their triply meso-meso-, beta-beta, and beta-beta-linked fluorinated zinc oligoporphyrins were systematically examined using the time-dependent DFT method. The effect of the perfluorination on the zinc porphyrin (ZnP) causes the maximum 1.12 eV and 1.42 eV drops for the highest occupied and lowest unoccupied molecular orbital (HOMO and LUMO, respectively) levels, respectively. The electronic and excitation features of the fluorinated ZnPs are almost similar to the unfluorinated ones. However, the large antibonding contribution of the meso-fluorines disturbs the stabilization of the HOMO, resulting in a more effective reduction of both the HOMO-LUMO gaps and the lowest Q excitation energies with the increasing number of porphyrins compared to the unfluorination and the other types of fluorinations. It is found that the infinite fused fluorinated ZnP tapes with narrow gap (approximately = 0.1 eV-0.2 eV) as predicted by using the periodic-DFT level are slightly inferior to the near-zero gap semimetallic unfluorinated ZnP tape as a conducting molecular wire. The combination of the condensation and the meso- and/or beta-fluorination of ZnP can finely tune the LUMO level to the Fermi level of the electrodes for fabrication of n-type conducting materials. The fused fluoro-oligoporphyrins may then become new n-type organic semiconductors, provided they are well crystallized with a high electron mobility, such as the recently synthesized perfluoropentacene.
RESUMO
A theoretical prediction of the electronic structures of fully pi-conjugated zinc oligoporphyrins with curved surface, ring, tube, and ball-shaped structures was conducted as the objective for the future development of triply meso-meso-, beta-beta-, and beta-beta-linked planar zinc oligoporphyrins. The excitation energies and oscillator strengths for the optimal ring and ball structures were calculated using the time-dependent density functional theory (DFT). Although there is an extremely small energy difference of < 0.1 eV between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the ring structure relative to the same-sized triply linked planar one, the Q and B bands of the former are smaller redshifted excitation energies and intensified oscillator strengths than those of the latter due to the structurally shortened effective pi-conjugated lengths for the electron transition. It is expected that the ball structure becomes an excellent electron acceptor and shows the highly redshifted Q' band in the near-IR region relative to the monomer. The minimum value of the HOMO-LUMO energy gaps of the infinite-length ring structures was estimated using periodic boundary conditions within the DFT, resulting in the metallic characters of both the tube structures with and without the spiral triply linked porphyrin array. The relation between the diameters and strain energies of the tube and ball structures was also examined. The present fused zinc porphyrins may become more colorful materials with new optelectronic properties including artificial photosynthesis than the carbon nanotubes and fullerenes when the axial coordinations of the central metal of porphyrins are functionally used.