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Asthma, characterized as a chronic heterogeneous airway disease, often presents with common comorbid conditions. The concept of 'one-airway-one-disease' was coined, emphasizing the connection between asthma and upper airway comorbidities (UACs) such as allergic or non-allergic rhinitis, chronic rhinosinusitis with or without nasal polyps, and aspirin/nonsteroidal anti-inflammatory drug-exacerbated respiratory disease more than 20 years ago. Since then, numerous studies demonstrate that UACs are closely related and affect asthma phenotypes. Recognizing and managing these UACs are crucial aspects of comprehensive asthma care. Addressing these conditions as part of asthma treatment can lead to better control of symptoms, improved lung function and the quality of life. Moreover, it is important to explore the field of respiratory biologics that represent the latest advancements in medical treatment options for asthma patients with UACs.
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An electron transport layer (ETL) for highly efficient perovskite solar cells (PSCs) should exhibit superior electrical transport properties and have its band levels aligned with interfacing layers to ensure efficient extraction of photo-generated carriers. Nitrogen-doped TiO2 (TiO2:N) is considered a promising ETL because it offers higher electrical conductivity compared to conventional ETLs made from spray-pyrolyzed TiO2. However, the application of highly doped TiO2:N in PSCs is often limited by the misalignment of energy band levels with adjacent layers and reduced optical transparency. In this study, a novel approach is introduced to enhance the charge transport characteristics and accurately align the electronic band alignment of TiO2:N layer through nanoscale doping level grading, achieved through the pulsed laser deposition (PLD) technique. The TiO2:N ETL with a graded doping profile can combine characteristics of both highly doped and lightly doped phases on each side. Furthermore, a nanoscale doping gradation, employing an ultrathin sub-layer structure with graded doping levels, creates a smoothly cascading band-level alignment that bridges the adjacent layers, enhancing the transport of photo-generated carriers. Consequently, this method leads to a substantial increase in the power conversion efficiency (PCE), exceeding 22%, which represents a relative improvement of 11% compared to traditional spray-pyrolyzed TiO2-based PSCs.
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BACKGROUND AND AIMS: Owing to 2018 expanded diagnostic criteria for eosinophilic esophagitis (EoE) and thus a possible increase in diagnosis, previous studies on the global incidence and prevalence of EoE may need to be updated. We aimed to describe global, regional, and national trends in the incidence and prevalence of EoE from 1976 to 2022 and analyze their associations with geographic, demographic, and social factors through a systematic review. METHODS: We searched the PubMed/MEDLINE, Embase, CINAHL, Google Scholar, and Cochrane databases from their inception dates to December 20, 2022, for studies that reported the incidence or prevalence of EoE in the general population. We calculated the global incidence and prevalence of EoE using pooled estimates with 95% confidence intervals (CIs) and performed subgroup analysis based on age, sex, race, geographical area, World Bank income group, and diagnostic criteria of EoE. RESULTS: Forty studies met the eligibility criteria, including over 288 million participants and 147,668 patients with EoE from 15 countries across the five continents. The global pooled incidence and prevalence of EoE were 5.31 cases per 100,000 inhabitant-years (95% CI, 3.98-6.63; number of studies, 27; sample population, 42,191,506) and 40.04 cases per 100,000 inhabitant-years (95% CI, 31.10-48.98; number of studies, 20; sample population, 30,467,177), respectively. The pooled incidence of EoE was higher in high-income countries (vs low- or middle-income countries), males, and North America (vs Europe and Asia). The global prevalence of EoE followed a similar pattern. The pooled prevalence of EoE gradually increased from 1976 to 2022 (1976-2001; 8.18; 95% CI, 3.67-12.69 vs 2017-2022; 74.42; 95% CI, 39.66-109.19 cases per 100,000 inhabitant-years). CONCLUSIONS: The incidence and prevalence of EoE have increased substantially and vary widely across the world. Further research is needed to evaluate the incidence and prevalence of EoE in Asia, South America, and Africa.
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Esofagitis Eosinofílica , Masculino , Humanos , Esofagitis Eosinofílica/diagnóstico , Prevalencia , Incidencia , Europa (Continente) , América del NorteRESUMEN
MOTIVATION: Multi-omic profiling data, such as The Cancer Genome Atlas and pharmacogenomic data, facilitate research into cancer mechanisms and drug development. However, it is not easy for researchers to connect, integrate and analyze huge and heterogeneous data, which is a major obstacle to the utilization of cancer genomic data. RESULTS: We developed Cancer Genome Viewer (CGV), a user-friendly web service that provides functions to integrate and visualize cancer genome data and pharmacogenomic data. Users can easily select and customize the samples to be analyzed with the pre-defined selection options for patients' clinic-pathological features from multiple datasets. Using the customized dataset, users can perform subsequent data analyses comprehensively, including gene set analysis, clustering or survival analysis. CGV also provides pre-calculated drug response scores from pharmacogenomic data, which may facilitate the discovery of new cancer targets and therapeutics. AVAILABILITY AND IMPLEMENTATION: CGV web service is implemented with the R Shiny application at http://cgv.sysmed.kr and the source code is freely available at https://git.sysmed.kr/sysmed_public/cgv. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
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Neoplasias , Farmacogenética , Humanos , Análisis de Datos , Programas Informáticos , Genoma , Neoplasias/tratamiento farmacológico , Neoplasias/genéticaRESUMEN
With the ongoing COVID-19 pandemic, several previous studies from different countries showed that physical activity (PA) decreased during the COVID-19 outbreak. However, few studies have examined the recent tendency of PA in the adolescent population. Thus, we aimed to investigate the long-term trend of PA in Korean youth and the prevalence changes between before and during the COVID-19 pandemic. Data from Korea Youth Risk Behavior Web-Based Survey (KYRBS) was collected for consecutive years between 2009 and 2021. The period was separated into prepandemic (2009-2019), early-pandemic (2020), and mid-pandemic (2021). Self-reported amount of PA was categorized into four groups (insufficient, aerobic, muscle strengthening, and both physical activities) according to World Health Organization (WHO) PA guidelines. A total of 840 488 adolescents aged 12-18 who fully responded to the survey were selected (response rate: 95.2%). The 13-year trends in the proportion of adolescents who reported aerobic and muscle-strengthening activities met or exceeded 2020 WHO exercise guidelines for adolescents plateaued (11.9% from 2009 to 2011, 14.2% from 2018 to 2019, 14.4% from 2020, and 14.0% from 2021); however, the slope decreased during the pandemic (ßdiff , -0.076; 95% confidence interval [CI], -0.123 to -0.029). Proportion of sufficient aerobic exercise among adolescents sharply decreased midst the pandemic (28.0% from 2009 to 2011, 29.4% from 2018 to 2019, and 23.8% from 2020; ßdiff , -0.266; 95% CI, -0.306 to -0.226) but increased again in 2021 (26.0% from mid-COVID 19; 95% CI, 25.4-26.7). Similar patterns were observed in Metabolic Equivalent Task (MET) score (MET-min/week; 804.1 from 2018 to 2019, 720.9 from 2020, and 779.6 from 2021). The mean difference in MET score between pre-COVID and post-COVID was -55.4 MET-min/week (95% CI, -70.5 to -40.3). Through a nationwide representative study, there was no significant difference with regard to the number of Korean adolescents who achieved the PA guidelines (pre and postpandemic); however, the prevalence of recommended levels of PA needs to increase more based on the trend before the COVID-19 outbreak. The findings of this study suggest reinforcement of the importance of public health policies for Korean youths to be more physically active, especially during and after the pandemic.
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COVID-19 , Pandemias , Humanos , Adolescente , Estudios Transversales , COVID-19/epidemiología , Ejercicio Físico/fisiología , República de Corea/epidemiologíaRESUMEN
BACKGROUND: Immunologic function in innate and adaptive immunity changes with the ageing process. Thus, age-related cytokine profiles in chronic rhinosinusitis (CRS) need to be investigated for precision medicine. OBJECTIVE: The objective of this study was to characterize age-related changes in immunologic profiles according to CRS subtypes. METHODS: Subjects in control (n = 29), CRS without nasal polyps (CRSsNP, n = 86), and CRS with nasal polyps (eosinophilic NP: ENP, n = 81; non-eosinophilic NP: NENP, n = 113) were enrolled in this study. Twenty markers for type 1/2/3 inflammation and other inflammatory processes were measured in homogenates of sinonasal tissues and statistically analysed. RESULTS: In control tissues, type 2/3 and proinflammatory mediators showed an inverse correlation with age. CRSsNP and NENP showed an age-related increase in type 2 cytokines and a decline in type 3 cytokines. Interestingly, the age-related decrease in type 3 mediators was associated with those of CT scores in NENP. ENP showed an age-related increase in type 3 cytokines with type 2 mediators sustained at high levels. Smokers with ENP demonstrated age-associated increases in type 1/2/3 mediators as well as CT scores. These age-related patterns in each CRS were confirmed by statistically adjusting atopy status, smoking history, and disease duration. CONCLUSION: Age-associated cytokine changes differed among CRS subtypes and control tissues. CRSsNP and NENP demonstrated a decline in type 3 mediators and increase in type 2 mediators, whereas type 3 mediators increased with age in ENP.
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Envejecimiento , Citocinas/metabolismo , Pólipos Nasales , Rinitis , Sinusitis , Adolescente , Adulto , Anciano , Envejecimiento/metabolismo , Envejecimiento/patología , Biomarcadores/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pólipos Nasales/metabolismo , Pólipos Nasales/patología , Rinitis/metabolismo , Rinitis/patología , Sinusitis/metabolismo , Sinusitis/patologíaRESUMEN
Severe asthma is an extremely heterogeneous clinical syndrome in which diverse cellular and molecular pathobiologic mechanisms exist, namely endotypes. The current system for endotyping severe asthma is largely based on inflammatory cellular profiles and related pathways, namely the dichotomy of type 2 response (resulting in eosinophilic inflammation) and non-type 2 response (reinforcing non-eosinophilic inflammation involving neutrophils or less inflammatory cells), forming the basis of a development strategy for novel therapies. Although specific subgroups of type 2 severe asthma patients may derive benefit from modern precision medicine targeting type 2 cytokines, there is no approved and effective therapeutic agent for non-type 2 severe asthma, which comprises nearly 50% of all asthma patients. Importantly, the critical implication of endoplasmic reticulum (ER) stress and unfolded protein response-in close relation with several pivotal cellular immune/inflammatory platforms including mitochondria, NLRP3 inflammasome, and phosphoinositide 3-kinase-δ-in the generation of corticosteroid resistance is now being increasingly demonstrated in numerous experimental settings of severe asthma. Consistent with these findings, recent clinical data from a large European severe asthma cohort, in which molecular phenotyping as well as diverse clinical and physiological parameters from severe asthmatic patients were incorporated, suggest a brand new framework for endotyping severe asthma in relation to ER-associated mitochondria and inflammasome pathways. These findings highlight the view that ER stress-associated molecular pathways may serve as a unique endotype of severe asthma, and thus present a novel insight into the current knowledge and future development of treatment to overcome corticosteroid resistance in heterogeneous severe asthma.
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Asma/etiología , Asma/metabolismo , Estrés del Retículo Endoplásmico , Inmunidad , Alérgenos/inmunología , Animales , Asma/diagnóstico , Biomarcadores , Citocinas/metabolismo , Eosinófilos/inmunología , Eosinófilos/metabolismo , Eosinófilos/patología , Humanos , Inflamación/etiología , Inflamación/metabolismo , Inflamación/patología , Neutrófilos/inmunología , Neutrófilos/metabolismo , Neutrófilos/patología , Orgánulos/metabolismo , Índice de Severidad de la Enfermedad , Evaluación de SíntomasRESUMEN
BACKGROUND: Respiratory fungal exposure is known to be associated with severe allergic lung inflammation. Airway epithelium is an essential controller of allergic inflammation. An innate immune recognition receptor, nucleotide-binding domain, leucine-rich-containing family, pyrin-domain-containing-3 (NLRP3) inflammasome, and phosphoinositide 3 kinase (PI3K)-δ in airway epithelium are involved in various inflammatory processes. OBJECTIVES: We investigated the role of NLRP3 inflammasome in fungi-induced allergic lung inflammation and examined the regulatory mechanism of NLRP3 inflammasome, focusing on PI3K-δ in airway epithelium. METHODS: We used two in vivo models induced by exposure to Aspergillus fumigatus (Af) and Alternaria alternata (Aa), as well as an Af-exposed in vitro system. We also checked NLRP3 expression in lung tissues from patients with allergic bronchopulmonary aspergillosis (ABPA). RESULTS: Assembly/activation of NLRP3 inflammasome was increased in the lung of Af-exposed mice. Elevation of NLRP3 inflammasome assembly/activation was observed in Af-stimulated murine and human epithelial cells. Similarly, pulmonary expression of NLRP3 in patients with ABPA was increased. Importantly, neutralisation of NLRP3 inflammasome derived IL-1ß alleviated pathophysiological features of Af-induced allergic inflammation. Furthermore, PI3K-δ blockade improved Af-induced allergic inflammation through modulation of NLRP3 inflammasome, especially in epithelial cells. This modulatory role of PI3K-δ was mediated through the regulation of mitochondrial reactive oxygen species (mtROS) generation. NLRP3 inflammasome was also implicated in Aa-induced eosinophilic allergic inflammation, which was improved by PI3K-δ blockade. CONCLUSION: These findings demonstrate that fungi-induced assembly/activation of NLRP3 inflammasome in airway epithelium may be modulated by PI3K-δ, which is mediated partly through the regulation of mtROS generation. Inhibition of PI3K-δ may have potential for treating fungi-induced severe allergic lung inflammation.
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Alternariosis/enzimología , Alternariosis/inmunología , Aspergilosis Broncopulmonar Alérgica/enzimología , Aspergilosis Broncopulmonar Alérgica/inmunología , Estrés del Retículo Endoplásmico/inmunología , Inmunidad Innata/inmunología , Fosfatidilinositol 3-Quinasas/inmunología , Animales , Aspergillus fumigatus , Biomarcadores/análisis , Bronquios/citología , Células Cultivadas , Células Epiteliales/inmunología , Femenino , Humanos , Inflamasomas/inmunología , Ratones , Ratones Endogámicos C57BL , Especies Reactivas de Oxígeno/inmunologíaRESUMEN
PURPOSE OF REVIEW: In this review, we will integrate recent knowledge on endoplasmic reticulum (ER) stress and allergy, thereby highlighting the therapeutic potential of ER stress in the context of precision medicine for allergic diseases. RECENT FINDINGS: Emerging evidence suggests that allergic diseases are very heterogeneous having numerous endotypes. This leads to the new era of modern medicine, which assumes that a particular endotype-driven therapy, called precision medicine, would be more efficacious in a specific group of patients rather than in all patients. Currently, a dichotomy involving type 2/non-type 2 immune response underlies most of the studies on inflammatory and immunologic mechanisms of allergic disorders. Whereas there are several approved or investigational endotype-driven therapeutic agents targeting type 2 immune responses, investigation of mechanisms and endotype-driven interventions regarding non-type 2 immune response lags far behind. Considering that non-type 2 immune response may represent a significant proportion of allergic disease, particularly corticosteroid-resistant severe disease, defining a novel concept of endotype-driven approach may be essential. Recently, stress responses originate from the endoplasmic reticulum (ER) and the associated inflammatory molecular platform has been suggested as a crucial player of immune and inflammatory responses. This implies that ER stress-related pathways may represent a new endotype-driven therapeutic strategy in the treatment of allergic diseases.
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Estrés del Retículo Endoplásmico/fisiología , Hipersensibilidad/fisiopatología , Animales , Humanos , Hipersensibilidad/terapia , Medicina de PrecisiónRESUMEN
As silicon-based electronics approach the limit of improvements to performance and capacity through dimensional scaling, attention in the semiconductor field has turned to graphene, a single layer of carbon atoms arranged in a honeycomb lattice. Its high mobility of charge carriers (electrons and holes) could lead to its use in the next generation of high-performance devices. Graphene is unlikely to replace silicon completely, however, because of the poor on/off current ratio resulting from its zero bandgap. But it could be used to improve silicon-based devices, in particular in high-speed electronics and optical modulators.
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BACKGROUND: Sensitisation with Aspergillus fumigatus (Af) is known to be associated with severe allergic lung inflammation, but the mechanism remains to be clarified. Phosphoinositide 3-kinase (PI3K)-δ and endoplasmic reticulum (ER) stress are suggested to be involved in steroid-resistant lung inflammation. We aimed to elucidate the role of PI3K-δ and its relationship with ER stress in fungus-induced allergic lung inflammation. METHODS: Using Af-exposed in vivo and in vitro experimental systems, we examined whether PI3K-δ regulates ER stress, thereby contributing to steroid resistance in fungus-induced allergic lung inflammation. Moreover, we checked expression of an ER stress marker in lung tissues isolated from patients with allergic bronchopulmonary aspergillosis. RESULTS: Af-exposed mice showed that ER stress markers, unfolded protein response (UPR)-related proteins, phosphorylated Akt, generation of mitochondrial reactive oxygen species (mtROS), eosinophilic allergic inflammation, and airway hyperresponsiveness (AHR) were increased in the lung. Similarly, glucose-regulated protein 78 was increased in lung tissues of patients with ABPA. A PI3K-δ inhibitor reduced Af-induced increases in ER stress markers, UPR-related proteins, allergic inflammation and AHR in mice. However, dexamethasone failed to reduce Af-induced allergic inflammation, AHR and elevation of ER stress. Administration of an ER stress inhibitor or a mtROS scavenger improved Af-induced allergic inflammation. The PI3K-δ inhibitor reduced Af-induced mtROS generation and the mtROS scavenger ameliorated ER stress. In primary cultured tracheal epithelial cells, Af-induced ER stress was inhibited by blockade of PI3K-δ. CONCLUSIONS: These findings suggest that PI3K-δ regulates Af-induced steroid-resistant eosinophilic allergic lung inflammation through ER stress.
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Aspergilosis Broncopulmonar Alérgica/enzimología , Aspergilosis Broncopulmonar Alérgica/etiología , Estrés del Retículo Endoplásmico/fisiología , Fosfatidilinositol 3-Quinasas/fisiología , Adenina/análogos & derivados , Adenina/farmacología , Animales , Biomarcadores/análisis , Western Blotting , Lavado Broncoalveolar , Proteínas Potenciadoras de Unión a CCAAT/análisis , Femenino , Glutatión/análisis , Disulfuro de Glutatión/análisis , Inmunoglobulina E/sangre , Inflamación/enzimología , Inflamación/etiología , Ratones , Ratones Endogámicos C57BL , Microscopía Confocal , Quinazolinas/farmacología , ARN Interferente Pequeño/análisisRESUMEN
Incomplete clearance of apoptotic cells and reactive oxygen species (ROS) release are known to trigger inflammasome activation causing severe inflammation in acute lung injury and various metabolic and autoimmune diseases. Moreover, it has been reported that apoptotic cell clearance and ROS-mediated apoptosis critically depend on mitochondrial uncoupling protein-2 (UCP2). However, the relationship between UCP2 and inflammasome activation has not been studied. This report investigates the role of UCP2 in the expression and activation of NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome in human macrophages. We found that UCP2 overexpression significantly enhanced the expression levels of NLRP3. The NLRP3 expression levels were significantly suppressed in THP1 cells treated with genipin, a UCP2 inhibitor, compared to controls. In addition, genipin altered adenosine triphosphate (ATP)- and hydrogen peroxide (H2O2)-mediated interleukin-1 beta (IL-1ß) secretion and significantly suppressed caspase-1 activity in inflammasome-activated human macrophages. Taken together, our results suggest that genipin modulates NLRP3 inflammasome activation and ATP- or H2O2-mediated IL-1ß release.
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Proteínas Portadoras/antagonistas & inhibidores , Inflamasomas/efectos de los fármacos , Canales Iónicos/inmunología , Iridoides/farmacología , Proteínas Mitocondriales/inmunología , Apoptosis/inmunología , Proteínas Portadoras/biosíntesis , Proteínas Portadoras/metabolismo , Caspasa 1/inmunología , Células Cultivadas , Activación Enzimática/inmunología , Regulación de la Expresión Génica , Humanos , Inflamasomas/metabolismo , Inflamación/inmunología , Interleucina-1beta/inmunología , Canales Iónicos/antagonistas & inhibidores , Canales Iónicos/biosíntesis , Macrófagos/inmunología , Proteínas Mitocondriales/antagonistas & inhibidores , Proteínas Mitocondriales/biosíntesis , Proteína con Dominio Pirina 3 de la Familia NLR , Especies Reactivas de Oxígeno/inmunología , Proteína Desacopladora 2RESUMEN
We report on new fabrication methods for a transparent, hierarchical, and patterned electrode comprised of either carbon nanotubes or zinc oxide nanorods. Vertically aligned carbon nanotubes or zinc oxide nanorod arrays were fabricated by either chemical vapor deposition or hydrothermal growth, in combination with photolithography. A transparent conductive graphene layer or zinc oxide seed layer was employed as the transparent electrode. On the patterned surface defined using photoresist, the vertically grown carbon nanotubes or zinc oxides could produce a concentrated electric field under applied DC voltage. This periodic electric field was used to align liquid crystal molecules in localized areas within the optical cell, effectively modulating the refractive index. Depending on the material and morphology of these patterned electrodes, the diffraction efficiency presented different behavior. From this study, we established the relationship between the hierarchical structure of the different electrodes and their efficiency for modulating the refractive index. We believe that this study will pave a new path for future optoelectronic applications.
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Microelectrodos , Nanotecnología/instrumentación , Nanotubos de Carbono/química , Nanotubos/química , Refractometría/instrumentación , Óxido de Zinc/química , Cristalización/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Luz , Ensayo de Materiales , Conformación Molecular , Nanotubos/efectos de la radiación , Nanotubos/ultraestructura , Nanotubos de Carbono/efectos de la radiación , Nanotubos de Carbono/ultraestructura , Dispersión de Radiación , Óxido de Zinc/efectos de la radiaciónRESUMEN
Insulin-like growth factor (IGF)-I has been recognized to play critical roles in the pathogenesis of asthma, whereas IGF-binding protein (IGFBP)-3 blocks crucial physiologic manifestations of asthma. IGF-I enhances subepithelial fibrosis, airway inflammation, airway hyperresponsiveness, and airway smooth muscle hyperplasia by interacting with various inflammatory mediators and complex signaling pathways, such as intercellular adhesion molecule-1, and the hypoxia-inducible factor/vascular endothelial growth factor axis. On the other hand, IGFBP-3 decreases airway inflammation and airway hyperresponsiveness through IGFBP-3 receptor-mediated activation of caspases, which subsequently inhibits NF-κB signaling pathway. It also inhibits the IGF-I/hypoxia-inducible factor/vascular endothelial growth factor axis via IGF-I-dependent and/or IGF-I-independent mechanisms. This Translational Review summarizes the role of IGF-I and IGFBP-3 in the context of allergic airway disease, and discusses the therapeutic potential of various strategies targeting the IGF-I and IGFBP-3 signaling pathways for the management of asthma.
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Antiasmáticos/uso terapéutico , Asma/tratamiento farmacológico , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/uso terapéutico , Factor I del Crecimiento Similar a la Insulina/antagonistas & inhibidores , Pulmón/efectos de los fármacos , Terapia Molecular Dirigida , Transducción de Señal/efectos de los fármacos , Animales , Asma/metabolismo , Asma/fisiopatología , Diseño de Fármacos , Humanos , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Pulmón/metabolismo , Pulmón/fisiopatología , Receptor IGF Tipo 1/metabolismo , Receptores de Superficie Celular/metabolismo , Proteínas Recombinantes/uso terapéuticoRESUMEN
We construct some results on the regularity of solutions and the approximate controllability for neutral functional differential equations with unbounded principal operators in Hilbert spaces. In order to establish the controllability of the neutral equations, we first consider the existence and regularity of solutions of the neutral control system by using fractional power of operators and the local Lipschitz continuity of nonlinear term. Our purpose is to obtain the existence of solutions and the approximate controllability for neutral functional differential control systems without using many of the strong restrictions considered in the previous literature. Finally we give a simple example to which our main result can be applied.
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Modelos Teóricos , AlgoritmosRESUMEN
It is critical to design bifunctional passivation molecules to simultaneously passivate the charge transport layer and perovskite layer at the charge transport layer/perovskite interface in perovskite solar cells (PSCs). In this study, we investigate the effect of para-substituted benzoic acid with different Hammett constants (σ) on the photovoltaic performance of PSCs. Two passivation molecules 4-aminomethylbenzoic acid (4-AMBA) and 4-sulfamoylbenzoic acid (4-SABA) are used to passivate the SnO2 surface with carboxylic acid and the perovskite with para-substituent electron-donating -CH2NH2 (σ = ca. -0.02) and electron-withdrawing -SO2NH2 (σ = ca. +0.60). Compared with non-passivated PSC, the passivation improves the power conversion efficiency (PCE) mainly due to the increased open-circuit voltage (VOC) and fill factor (FF), where the -SO2NH2 substituent is better in improving the photovoltaic performance than the -CH2NH2 one. The trap density is more reduced and the charge extraction ability is more improved by 4-SABA than by 4-AMBA, which indicates that the weak electron-withdrawing nature of a para-substituent such as -SO2NH2 is better for the passivation of the bottom perovskite than a weak electron-donating -CH2NH2 substituent. Consequently, the passivation with 4-SABA enhances the PCE from 22.27% to 23.64%, along with improved long-term stability. This work highlights for the first time the role of the Hammett constant in the surface passivation of PSCs.
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Defect passivation using two-dimensional (2D)-layered perovskites with organic spacers on 3D bulk perovskites has been proposed as an effective strategy to improve perovskite solar cell stability and efficiency. Specifically, fluorination of the organic spacers has been employed due to the resulting hydrophobic nature and the defect passivation characteristics. In addition to the type of functional groups attached to the spacer molecules, conformational changes of fluorine isomers on layered perovskites can provide an extended strategy to control a variety of opto-electrical properties related to the interlayer spacing. As a model system for the structural isomer of fluorinated spacers, meta-CF3 and para-CF3 groups anchored to phenethylammonium iodide (PEAI) spacer molecules are employed to synthesize 2D perovskites and to investigate their full potential as an interfacial modifier for perovskite solar cells. The fluorination position change leads to altered opto-electrical characteristics in layered perovskites. Although they possess identical functional groups, the different orientations of the functional groups used in the perovskite layer deposited on the 3D perovskite absorber result in distinct electrical properties of 2D/3D heterostructures due to dissimilar intermolecular interactions. The 2D perovskite with meta-CF3-PEAI spacers exhibits an enhancement of the charge transport in the out-of-plane orientation and an improved suppression of the trap states of 3D perovskites while also providing a more favorable energy alignment for efficient charge transfers. Theoretical simulations are consistent with the experimental results. The structural isomers of fluorination anchoring to spacer cations alter the structural configuration of the spacer as well as the interlayer spacing that can improve the performance and the stability of 2D/3D perovskite solar cells.