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Silicate glasses are durable solids, and yet they are chemically unstable in contact with aqueous fluids-this has important implications for numerous industrial applications related to the corrosion resistance of glasses, or the biogeochemical weathering of volcanic glasses in seawater. The aqueous dissolution of synthetic and natural glasses results in the formation of a hydrated, cation-depleted near-surface alteration zone and, depending on alteration conditions, secondary crystalline phases on the surface. The long-standing accepted model of glass corrosion is based on diffusion-coupled hydration and selective cation release, producing a surface-altered zone. However, using a combination of advanced atomic-resolution analytical techniques, our data for the first time reveal that the structural and chemical interface between the pristine glass and altered zone is always extremely sharp, with gradients in the nanometre to sub-nanometre range. These findings support a new corrosion mechanism, interfacial dissolution-reprecipitation. Moreover, they also highlight the importance of using analytical methods with very high spatial and mass resolution for deciphering the nanometre-scale processes controlling corrosion. Our findings provide evidence that interfacial dissolution-reprecipitation may be a universal reaction mechanism that controls both silicate glass corrosion and mineral weathering.
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Vidrio/química , Nanoestructuras/química , Nanoestructuras/ultraestructura , Silicatos/química , Solventes/química , Agua/química , Corrosión , Ensayo de Materiales , Tamaño de la Partícula , Propiedades de SuperficieRESUMEN
The ultimate goal of vascular tissue engineering is the production of functional grafts for clinical use. Difficulties acquiring autologous endothelial cells have motivated the search for alternative cell sources. Differentiation of dermal fibroblasts towards several mesenchymal lineages as well as endothelial cells has been proposed. The aim of the present study was to investigate the endothelial differentiation capacity of human dermal fibroblasts on a gene expression, protein expression and functional physiological level. Endothelial differentiation of fibroblasts was induced by culturing cells in 30% human serum, but not in fetal calf serum. Expression of proteins and genes relevant for endothelial function and differentiation was increased after induction. Furthermore, fibroblasts exposed to 30% human serum displayed increased uptake of low-density lipoprotein and formation of capillary-like networks. The results of this study may have an impact on cell sourcing for vascular tissue engineering, and the development of methods for vascularization of autologous tissue engineered constructs.
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Diferenciación Celular , Dermis/citología , Células Endoteliales/citología , Fibroblastos/citología , Linaje de la Célula , Células Cultivadas , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Genoma Humano , Humanos , Suero , Ingeniería de TejidosRESUMEN
Structures comprising single-crystal, iron-carbon-based nanowires encapsulated by multiwall carbon nanotubes self-organize on inert substrates exposed to the products of ferrocene pyrolysis at high temperature. The most commonly observed encapsulated phases are Fe3C, α-Fe, and γ-Fe. The observation of anomalously long-period lattice spacings in these nanowires has caused confusion since reflections from lattice spacings of ≥ 0.4 nm are kinematically forbidden for Fe3C, most of the rarely observed, less stable carbides, α-Fe, and g-Fe. Through high-resolution electron microscopy, selective area electron diffraction, and electron energy loss spectroscopy we demonstrate that the observed long-period lattice spacings of 0.49, 0.66, and 0.44 nm correspond to reflections from the (100), (010), and (001) planes of orthorhombic Fe3C (space group Pnma). Observation of these forbidden reflections results from dynamic scattering of the incident beam as first observed in bulk Fe3C crystals.With small amounts of beam tilt these reflections can have significant intensities for crystals containing glide planes such as Fe3C with space groups Pnma or Pbmn.
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INTRODUCTION: Understanding how patients experience their disease is a vital step in optimal disease management, and patient- and observer-reported outcome (PRO and ObsRO, respectively) measures can add important details to clinical information that is obtained as novel treatments are developed. Instruments that measure meaningful symptoms and impacts from the perspective of pediatric patients with cholestatic liver disease or their caregivers are needed. This study aimed to identify salient concepts in pediatric cholestatic liver disease, develop novel PRO and ObsRO instruments, and establish the instruments' content validity. METHODS: Relevant signs, symptoms, and impacts of cholestatic liver disease were identified through a literature review, interviews with expert clinicians, and concept elicitation interviews with children and caregivers of children who had progressive familial intrahepatic cholestasis (PFIC), Alagille syndrome, biliary atresia, or primary sclerosing cholangitis. Additional cognitive debriefing interviews with patients and caregivers were performed to ensure that participants could understand the instructions, questions, and response scales of the PRO and ObsRO instruments, with modifications made as necessary to improve comprehension and/or usability. RESULTS: A total of 36 interviews with patients and caregivers were conducted. Pruritus and sleep disturbance (e.g., difficulty falling or staying asleep due to itch) were identified as the most problematic symptom and significant impact, respectively, of the pediatric cholestatic liver diseases assessed. The ObsRO and PRO instruments, called PRUCISION, focus on these key disease features in the morning and evening. Several modifications were made to the draft instruments following cognitive interviews. The final PRUCISION PRO and ObsRO measures are designed as an electronic diary to be completed twice daily. The response scales include pictorial, verbal, and numeric scales. CONCLUSION: Novel PRO and ObsRO PRUCISION instruments were created that evaluate the patient experience of cholestatic pruritus in children with PFIC and other cholestatic liver diseases. The content validity of the PRUCISION instruments is established.
Bile, a greenish liquid that is made in the liver, is released into the gut to help digest food. In cholestatic liver disease (CLD), bile flow is interrupted, and bile can build up in the body. One potential effect of this buildup is pruritus, or itchiness of the skin, which can be so intense that it interferes with daily activities. In this study, interviews were done with doctors, patients, and their caregivers to develop new tools to evaluate the most impactful symptoms of CLD in children. After interviewing five doctors and 36 patients and caregivers, two questionnaires called PRUCISION were developed and refined. During this process, participants were first asked about the frequency, severity, duration, and impact of their or their child's symptoms; pruritus was identified as the most common and disruptive symptom associated with CLD, even interfering with sleep. Then, the wording of the questionnaires was modified to make them easier to understand, particularly for younger children. The researchers also had patients do a card-sorting task to ensure that they understood the picture-based responses used in the questionnaires. Finally, more details were added to the instructions for caregivers to more clearly define scratching behaviors. In summary, the questionnaires developed in this study include the perspective of the patient or their caregiver and may be useful to see if new treatments can impact the most prominent symptoms and impacts associated with CLD.
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Colestasis Intrahepática , Trastornos del Sueño-Vigilia , Niño , Colestasis Intrahepática/terapia , Humanos , Prurito/diagnóstico , Prurito/etiología , Sueño , Trastornos del Sueño-Vigilia/diagnóstico , Trastornos del Sueño-Vigilia/etiologíaRESUMEN
INTRODUCTION: Patients with cholestatic liver disease, including progressive familial intrahepatic cholestasis (PFIC) and Alagille syndrome, may have debilitating pruritus, and reducing pruritus is a key therapeutic goal. However, few instruments are available that adequately measure pruritus in pediatric patients with cholestatic liver disease. The objectives of the current study were to establish the measurement properties of the novel PRUCISION patient-reported outcome (PRO) and observer-reported outcome (ObsRO) instruments and to estimate a threshold for clinically meaningful change in pruritus score. METHODS: The PRO/ObsRO instruments are completed twice daily via electronic diary and include 5-point pictorial responses to assess pruritus. Sleep disturbance and tiredness were quantified using 5-point pictorial responses, yes/no responses, and numerical ratings. Data from PEDFIC 1 (NCT03566238), a phase 3 study evaluating odevixibat efficacy and safety in children with PFIC, were used to assess the psychometric properties of these instruments. Quantitative assessments included evaluation of test-retest reliability, determination of construct validity via convergent and known-group validity analyses, and characterization of sensitivity to change. A threshold for within-patient meaningful change from baseline to week 24 was determined using blinded data from PEDFIC 1 and distribution- and anchor-based analyses. RESULTS: Because the majority of patients in PEDFIC 1 were aged < 8 years (n = 52/62) and thus too young to complete the PRO instrument, which was intended for patients aged ≥ 8 years, the small sample size of patients who completed the PRO precluded a full psychometric analysis of the PRO instrument. The ObsRO was completed by a caregiver of every patient in PEDFIC 1. The ObsRO instrument had acceptable test-retest reliability based on intraclass correlation values (most > 0.75). Convergent validity analyses revealed moderate-to-strong correlations (r ≥ 0.3) between baseline ObsRO pruritus scores and baseline Global Impression of Symptoms (GIS) items. In known-groups validity analyses, there were significant differences between baseline groups defined by the GIS for ObsRO pruritus scores and for some sleep disturbance scores. Week 24 ObsRO scores were in the expected direction in groups defined by the Global Impression of Change scale (i.e., improved or not improved); many mean differences between these groups were significant. Sensitivity to change for the ObsRO PRUCISION instrument was also demonstrated by moderate-to-strong Pearson correlations between change from baseline to weeks 21-24 in ObsRO scores and GIS items (r ≥ 0.3). Based on these analyses, a within-patient change of -1.00 from baseline in ObsRO pruritus score was determined to be clinically meaningful. CONCLUSION: The PRUCISION ObsRO instrument is reliable, valid, and sensitive to change, supporting its use as a tool to measure pruritus and sleep disturbance in patients with PFIC and other pediatric cholestatic liver diseases.
Progressive familial intrahepatic cholestasis (PFIC) is a collection of liver diseases that typically affects very young children. A problematic symptom of PFIC is extremely itchy skin, or pruritus, that can keep patients and their families up at night. The PRUCISION questionnaire was developed to measure the severity of a patient's pruritus and sleep disturbance from the perspective of the patient's caregiver. The current study had two primary goals: (1) to assess whether PRUCISION could reliably measure these symptoms and detect changes over time relative to other established rating scales that assess related concepts, and (2) to identify what score change on PRUCISION could be considered clinically meaningful. To do this, data from a clinical study, called PEDFIC 1, in patients with PFIC were used: patient's scores on PRUCISION from their caregiver's perspective were compared with scores on other established scales, first before any treatment was given in PEDFIC 1, and then again after 24 weeks of treatment with a drug called odevixibat. In general, there was good agreement between PRUCISION scores and scores on other scales. For example, when PRUCISION scores indicated that symptoms improved, this tended to correlate with improvement on other measures. Additionally, these analyses indicated that if the PRUCISION score drops by 1 point or more, that can be considered a clinically important change. Overall, this study found that the caregiver-reported PRUCISION questionnaire is valid for assessing changes in pruritus and sleep symptoms in patients with PFIC, which may benefit patients as new treatments are developed.
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Colestasis Intrahepática , Benzodiazepinas , Butiratos , Niño , Colestasis Intrahepática/complicaciones , Humanos , Prurito/diagnóstico , Prurito/etiología , Psicometría , Reproducibilidad de los ResultadosRESUMEN
The twin interface structure in twinning superlattice InP nanowires with zincblende structure has been investigated using electron exit wavefunction restoration from focal series images recorded on an aberration-corrected transmission electron microscope. By comparing the exit wavefunction phase with simulations from model structures, it was possible to determine the twin structure to be the ortho type with preserved In-P bonding order across the interface. The bending of the thin nanowires away from the intended 110 axis could be estimated locally from the calculated diffraction pattern, and this parameter was successfully taken into account in the simulations.
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BACKGROUND/AIMS: Our aim was to investigate whether muscarinic and nicotinic receptors mediate nitric oxide release during motor events in the rat stomach. METHODS: Isolated rat stomach volume changes were monitored in an organ bath setup with an intragastric balloon coupled to a barostat and studied in basal conditions and during electrical vagal stimulation (EVS). In conscious rats, the intragastric pressure (IGP) was measured during test meal infusion. RESULTS: In the presence of N(G)-nitro-L-arginine methyl ester (L-NAME; 0.1 mmol/l), EVS induced significant gastric contractions (mean +/- SEM = 0.27 +/- 0.04 ml; n = 6) that could be blocked by atropine (3 micromol/l) and hexamethonium (0.1 mmol/l). In the presence of atropine and/or hexamethonium, EVS-induced relaxations could not be blocked by L-NAME, while exogenous nitric oxide could still relax the stomach. In conscious rats, atropine (1 mg kg(-1)) initially decreased IGP, while during further distension it increased IGP. In the presence of L-NAME (30 mg kg(-1)) atropine consistently decreased IGP. L-NAME alone significantly increased IGP during the test meal infusion, but this effect was reduced in the presence of atropine. CONCLUSION: These findings indicate a role for nicotinic and muscarinic receptors in the vagal-stimulation-induced activation of nitrergic nerves in the rat stomach.
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Antagonistas Muscarínicos/farmacología , Músculo Liso/efectos de los fármacos , Antagonistas Nicotínicos/farmacología , Receptores Muscarínicos/fisiología , Receptores Nicotínicos/fisiología , Estómago/efectos de los fármacos , Animales , Estimulación Eléctrica , Femenino , Dilatación Gástrica/fisiopatología , Técnicas In Vitro , Contracción Muscular/efectos de los fármacos , Relajación Muscular/efectos de los fármacos , Tono Muscular/efectos de los fármacos , Óxido Nítrico/antagonistas & inhibidores , Óxido Nítrico/farmacología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Presión , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Estómago/inervación , Estómago/fisiologíaRESUMEN
Background: The BREATHE study is a cross-sectional study of real-life patients with asthma and/or COPD in Denmark and Sweden aiming to increase the knowledge across severities and combinations of obstructive airway disease. Design: Patients with suspicion of asthma and/or COPD and healthy controls were invited to participate in the study and had a standard evaluation performed consisting of questionnaires, physical examination, FeNO and lung function, mannitol provocation test, allergy test, and collection of sputum and blood samples. A subgroup of patients and healthy controls had a bronchoscopy performed with a collection of airway samples. Results: The study population consisted of 1403 patients with obstructive airway disease (859 with asthma, 271 with COPD, 126 with concurrent asthma and COPD, 147 with other), and 89 healthy controls (smokers and non-smokers). Of patients with asthma, 54% had moderate-to-severe disease and 46% had mild disease. In patients with COPD, 82% had groups A and B, whereas 18% had groups C and D classified disease. Patients with asthma more frequently had childhood asthma, atopic dermatitis, and allergic rhinitis, compared to patients with COPD, asthma + COPD and Other, whereas FeNO levels were higher in patients with asthma and asthma + COPD compared to COPD and Other (18 ppb and 16 ppb vs 12.5 ppb and 14 ppb, p < 0.001). Patients with asthma, asthma + COPD and Other had higher sputum eosinophilia (1.5%, 1.5%, 1.2% vs 0.75%, respectively, p < 0.001) but lower sputum neutrophilia (39.3, 43.5%, 40.8% vs 66.8%, p < 0.001) compared to patients with COPD. Conclusions: The BREATHE study provides a unique database and biobank with clinical information and samples from 1403 real-life patients with asthma, COPD, and overlap representing different severities of the diseases. This research platform is highly relevant for disease phenotype- and biomarker studies aiming to describe a broad spectrum of obstructive airway diseases.
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We have demonstrated a method to disperse and exfoliate graphite to give graphene suspended in water-surfactant solutions. Optical characterization of these suspensions allowed the partial optimization of the dispersion process. Transmission electron microscopy showed the dispersed phase to consist of small graphitic flakes. More than 40% of these flakes had <5 layers with approximately 3% of flakes consisting of monolayers. Atomic resolution transmission electron microscopy shows the monolayers to be generally free of defects. The dispersed graphitic flakes are stabilized against reaggregation by Coulomb repulsion due to the adsorbed surfactant. We use DLVO and Hamaker theory to describe this stabilization. However, the larger flakes tend to sediment out over approximately 6 weeks, leaving only small flakes dispersed. It is possible to form thin films by vacuum filtration of these dispersions. Raman and IR spectroscopic analysis of these films suggests the flakes to be largely free of defects and oxides, although X-ray photoelectron spectroscopy shows evidence of a small oxide population. Individual graphene flakes can be deposited onto mica by spray coating, allowing statistical analysis of flake size and thickness. Vacuum filtered films are reasonably conductive and are semitransparent. Further improvements may result in the development of cheap transparent conductors.
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BACKGROUND: Recently, there has been an intense ongoing search for suitable cell sources for vascular tissue engineering. Previous studies report that cells with multilineage potential have been found within the connective stroma of the skin. In line with this, preliminary data from our group suggest that human dermal fibroblasts have the capacity to alter their phenotype into an endothelial cell-like phenotype in vitro. As a first step in using these cells in vascular tissue engineering, we investigated their ability to form an endothelial cell-like layer on a scaffold in vitro. Furthermore, we studied the possibility of seeding dermal fibroblasts on a scaffold and later commencing with induction toward an endothelial cell-like phenotype. METHODS: Cells cultured in either normal fibroblast medium or endothelial induction medium were seeded on a gelatin-based scaffold. To study the organization of cells, routine staining was performed. Differentiation was confirmed by Western blotting and immunohistochemistry with antibodies directed toward molecules commonly used to identify endothelial cells. RESULTS AND CONCLUSION: Our data support that human dermal fibroblasts differentiated toward endothelial cell-like cells prior to seeding showed histological resemblance to mature endothelial cells, while fibroblasts seeded and later induced into endothelial differentiation grew in multilayer. However, expression of various surface molecules indicative of an endothelial phenotype was seen using both techniques. In conclusion, the results presented in this study indicate that human dermal fibroblasts differentiated toward an endothelial cell-like phenotype may be a novel cell source for endothelialization of vascular grafts.
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Bioprótesis , Prótesis Vascular , Transdiferenciación Celular , Dermis/fisiología , Células Endoteliales/fisiología , Fibroblastos/fisiología , Ingeniería de Tejidos , Andamios del Tejido , Antígenos CD/metabolismo , Biomarcadores/metabolismo , Cadherinas/metabolismo , Movimiento Celular , Proliferación Celular , Células Cultivadas , Dermis/citología , Dermis/metabolismo , Células Endoteliales/metabolismo , Fibroblastos/metabolismo , Gelatina/química , Humanos , Óxido Nítrico Sintasa de Tipo III/metabolismo , Fenotipo , Diseño de Prótesis , Receptor de Bradiquinina B2/metabolismo , Factor de von Willebrand/metabolismoRESUMEN
What can we learn from embryogenesis to increase our understanding of how regeneration of damaged adult lung tissue could be induced in serious lung diseases such as chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), and asthma? The local tissue niche determines events in both embryogenesis and repair of the adult lung. Important constituents of the niche are extracellular matrix (ECM) molecules, including proteoglycans and glycosaminoglycans (GAGs). GAGs, strategically located in the pericellular and extracellular space, bind developmentally active growth factors (GFs) and morphogens such as fibroblast growth factors (FGFs), transforming growth factor-ß (TGF-ß), and bone morphogenetic proteins (BMPs) aside from cytokines. These interactions affect activities in many cells, including stem cells, important in development and tissue regeneration. Moreover, it is becoming clear that the "inherent code," such as sulfation of disaccharides of GAGs, is a strong determinant of cellular outcome. Sulfation patterns, deacetylations, and epimerizations of GAG chains function as tuning forks in gradient formation of morphogens, growth factors, and cytokines. Learning to tune these fine instruments, that is, interactions between GFs, chemokines, and cytokines with the specific disaccharide code of GAGs in the adult lung, could become the key to unlock inherent regenerative forces to override pathological remodeling. This review aims to provide an overview of the role GAGs play during development and similar events in regenerative efforts in the adult lung.
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Diferenciación Celular , Glicosaminoglicanos/metabolismo , Pulmón/metabolismo , Regeneración , Animales , Humanos , Pulmón/embriología , Pulmón/fisiologíaRESUMEN
Imidazoquinoline compounds, such as resiquimod (R-848), are well known topically active immune modifiers that bind to toll-like receptor 7 (TLR7). The aim of this study was to characterize the R-848 induced inflammatory response in mice and to validate the response using methyl-prednisolone and anti-TNF antibody. Intra-colonic application of R-848 to BALB/c mice induced a systemic transient elevation of TNF, CXCL1, IL-6, and IL-12p40 and a colonic elevation of cytokines/chemokines and iNOS, without infiltration of immune cells or epithelial destruction. Treatment with methyl-prednisolone or anti-TNF antibody attenuated the systemic (TNF, IL-6, IL-12p40, and CXCL1) and local (colonic TNF and iNOS mRNA expression) response induced by R-848. In summary, intra-colonic administration of R-848 induces an acute systemic and local inflammatory response, which can be attenuated by steroids or anti-TNF antibody. We suggest that the R-848 inflammatory model can be useful in future validation of new drugs for gastrointestinal inflammatory conditions.
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Colon/efectos de los fármacos , Colon/inmunología , Imidazoles/administración & dosificación , Inmunidad Innata/efectos de los fármacos , Inflamación/inducido químicamente , Inflamación/inmunología , Glicoproteínas de Membrana/antagonistas & inhibidores , Receptor Toll-Like 7/antagonistas & inhibidores , Animales , Citocinas/inmunología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Femenino , Inmunidad Innata/inmunología , Factores Inmunológicos/inmunología , Inflamación/patología , Ratones , Ratones Endogámicos BALB CRESUMEN
Dextran sulfate sodium (DSS)-induced colitis is one of the most frequently used rodent models for inflammatory bowel disease (IBD). The aim of this study was to validate the murine DSS-induced colitis model using four therapeutic agents for IBD. C57BL/6 mice were exposed to 3% DSS for 5days followed by 7-9 days of water (acute inflammation) or 20-31 days of water (chronic phase). Clinical symptoms, plasma and colonic inflammatory markers and histology were assessed for the efficacy of cyclosporine A (CsA), methotrexate or anti-IL-12p40 in acute colitis and of anti-IL-12p40 or an agonistic anti-CD3 antibody in chronic colitis. Cyclosporine A and anti-IL-12p40 (in the acute phase) and anti-CD3 (in the chronic phase) treatment attenuated local cytokine levels, improved clinical symptoms (CsA and anti-IL-12p40) and histology (CsA and anti-CD3). Further, anti-IL-12p40 treatment was partly efficacious in the chronic phase, whereas methotrexate showed no efficacy in the acute colitis. Thus, three of the current tested agents showed efficacy in the disease model, arguing that DSS-induced colitis can be used as a relevant model for the translation of mice data to human disease.
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Complejo CD3/inmunología , Colitis , Modelos Animales de Enfermedad , Inmunosupresores/uso terapéutico , Enfermedades Inflamatorias del Intestino , Subunidad p40 de la Interleucina-12/metabolismo , Enfermedad Aguda , Animales , Anticuerpos/administración & dosificación , Anticuerpos/uso terapéutico , Enfermedad Crónica , Colitis/inducido químicamente , Colitis/tratamiento farmacológico , Ciclosporina/administración & dosificación , Ciclosporina/uso terapéutico , Sulfato de Dextran , Femenino , Humanos , Inmunosupresores/administración & dosificación , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Subunidad p40 de la Interleucina-12/inmunología , Metotrexato/administración & dosificación , Metotrexato/uso terapéutico , Ratones , Ratones Endogámicos C57BLRESUMEN
The quantum-cutting process is observed in nanocrystalline fluoride (NaYF(4)) doped with Pr(3+). The thermal decomposition synthesis method was used to synthesize the NaYF(4) nanocrystals with an average size of 42 nm. The morphological high resolution transmission electron microscopy (HRTEM), structural X-ray diffraction (XRD) and spectroscopy, with the use of synchrotron radiation, have been employed to characterize the material. The different excitation energies created different luminescence response of the NaYF(4):Pr(3+) nanocrystals. The quantum-cutting phenomenon has been observed under the direct excitation of the 4f5d bands of praseodymium. After excitation of the NaYF(4) matrix this process is quenched and part of the energy is released through the self-trapped excitons emission. The origin of the different types of emission transitions has been analyzed in detail.
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Cristalización/métodos , Fluoruros/síntesis química , Luminiscencia , Nanoestructuras/química , Nanoestructuras/ultraestructura , Luz , Sustancias Macromoleculares/química , Ensayo de Materiales , Conformación Molecular , Tamaño de la Partícula , Fotones , Propiedades de Superficie , ItrioRESUMEN
There are several similarities between breast and ovarian cancer but anti-estrogen treatment is rarely used in ovarian cancer. We have previously shown that the most widely used anti-estrogen tamoxifen increased MMP-9 activity and endostatin generation in breast cancer. Here, we show that tamoxifen exposure of highly hormone responsive ovarian cancer cells decreased proliferation, and increased MMP-9 activity leading to increased levels of endostatin both in cell culture in vitro and in solid tumors of nude mice. Tamoxifen exposed tumors also exhibited significantly decreased tumor growth and vascularisation. Moreover, in ascites from ovarian cancer patients, MMP-9 was undetectable in majority of cases but a significant correlation of MMP-2 and endostatin was found. The effects on MMPs and endostatin generation are previously unknown mechanisms of estradiol and tamoxifen in ovarian cancer, which may have therapeutic implications in future anti-cancer options of hormone dependent ovarian cancer.
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Antineoplásicos Hormonales/farmacología , Endostatinas/biosíntesis , Metaloproteinasa 9 de la Matriz/metabolismo , Neoplasias Hormono-Dependientes/tratamiento farmacológico , Neovascularización Patológica/tratamiento farmacológico , Tamoxifeno/farmacología , Adulto , Anciano , Anciano de 80 o más Años , Animales , Ascitis/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Estradiol/farmacología , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Persona de Mediana Edad , Trasplante de Neoplasias , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/metabolismoRESUMEN
In this communication, we report the unusually extensive uni-directional self-assembly of nanoparticulate EuF(3) and discuss the origins behind such behaviour.
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A novel and rapid and continuous hydrothermal route to the synthesis of extensive ultra-thin 2D sodium titanate (Na(2)Ti(3)O(7)) nano-sheets using a superheated water flow at 450 degrees C and 24.1 MPa as a crystallizing medium is described. High resolution electron microscopy of the sheets revealed that they were a few layers thick and largely uncurled, highly crystalline despite their very short time under hydrothermal flow conditions. The sodium titanate sheets possessed excellent photocatalytic activity for decolourisation of methylene blue dye.
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We investigate electrical properties of self-assembled branched InAs nanowires. The branched nanowires are catalytically grown using chemical beam epitaxy, and three-terminal nanoelectronic devices are fabricated from the branched nanowires using electron-beam lithography. We demonstrate that, in difference from conventional macroscopic junctions, the fabricated self-assembled nanowire junction devices exhibit tunable nonlinear electrical characteristics and a signature of ballistic electron transport. As an example of applications, we demonstrate that the self-assembled three-terminal nanowire junctions can be used to implement the functions of frequency mixing, multiplication, and phase-difference detection of input electrical signals at room temperature. Our results suggest a wide range of potential applications of branched semiconductor nanostructures in nanoelectronics.
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We demonstrate here a method for controlled production of complex self-assembled three-dimensional networks of InAs nanowires on a substrate, based on sequentially seeded epitaxial nanowire structures, or "nanotrees". A position-controlled array of trunk nanowires is first produced using lithographically defined Au particles as seeds. With these wires positioned along the proper crystallographic directions with respect to each other, nanotree branches grow toward neighboring trunks, connecting them together. Finally, we investigate the crystal structure of the interconnected nanotrees, demonstrating that branch growth after the contact with the second trunk has an epitaxial relationship to that trunk.
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Controlled growth of nanowires is an important, emerging research field with many applications in, for example, electronics, photonics, and life sciences. Nanowires of zinc blende crystal structure, grown in the <111>B direction, which is the favoured direction of growth, usually have a large number of twin-plane defects. Such defects limit the performance of optoelectronic nanowire-based devices. To investigate this defect formation, we examine GaP nanowires grown by metal-organic vapour-phase epitaxy. We show that the nanowire segments between the twin planes are of octahedral shape and are terminated by {111} facets, resulting in a microfaceting of the nanowires. We discuss these findings in a nucleation context, where we present an idea on how the twin planes form. This investigation contributes to the understanding of defect formation in nanowires. One future prospect of such knowledge is to determine strategies on how to control the crystallinity of nanowires.