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1.
J Am Chem Soc ; 146(19): 13391-13398, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38691098

RESUMEN

Inverted p-i-n perovskite solar cells (PSCs) are easy to process but need improved interface characteristics with reduced energy loss to prevent efficiency drops when increasing the active photovoltaic area. Here, we report a series of poly ferrocenyl molecules that can modulate the perovskite surface enabling the construction of small- and large-area PSCs. We found that the perovskite-ferrocenyl interaction forms a hybrid complex with enhanced surface coordination strength and activated electronic states, leading to lower interfacial nonradiative recombination and charge transport resistance losses. The resulting PSCs achieve an enhanced efficiency of up to 26.08% for small-area devices and 24.51% for large-area devices (1.0208 cm2). Moreover, the large-area PSCs maintain >92% of the initial efficiency after 2000 h of continuous operation at the maximum power point under 1-sun illumination and 65 °C.

2.
Sensors (Basel) ; 24(3)2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38339514

RESUMEN

A large portion of the pipe infrastructure used in the chemical processing industry is susceptible to corrosion under insulation (CUI). Eddy current-based magnetic sensing is one of the methods that can be used as an early detector of this corrosion. However, the large sensor-to-pipe distances used in this method, due to the presence of insulation, limits the sensitivity to corrosion. This paper will describe the development of instrumentation and methods based on eddy current sensing with thin-film magnetic sensors. In particular, it focuses on the influence of the sensor angle relative to the radial magnetic field. The influence of this parameter on the amplitude of the measured signal was investigated by both finite element simulations and experimental observations. The measured magnetic field was found to be highly sensitive to small changes in sensor angle, with the estimated depth of a defect changing at a rate of 11.2 mm/degree of sensor rotation for small angles. It is also shown that a sensor aligned with the radial direction should be avoided, with an optimal sensor angle between 0.5 and 4 degrees. With the sensor in this angle range, the simulations have shown it should be possible to resolve the depth of corrosion to a resolution of 0.1 mm.

3.
Bioconjug Chem ; 34(10): 1802-1810, 2023 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-37751398

RESUMEN

Bioconjugates of antibodies and their derivatives radiolabeled with ß+-emitting radionuclides can be utilized for diagnostic PET imaging. Site-specific attachment of radioactive cargo to antibody delivery vectors provides homogeneous, well-defined immunoconjugates. Recent studies have demonstrated the utility of oxaziridine chemistry for site-specific labeling of methionine residues. Herein, we applied this approach to site-specifically radiolabel trastuzumab-derived Fab immunoconjugates with 68Ga, which can be used for in vivo PET imaging of HER2-positive breast cancer tumors. Initially, a reactive azide was introduced to a single solvent-accessible methionine residue in both the wild-type Fab and an engineered derivative containing methionine residue M74, utilizing the principles of oxaziridine chemistry. Subsequently, these conjugates were functionalized with a modified DFO chelator incorporating dibenzocyclooctyne. The resulting DFO-WT and DFO-M74 conjugates were radiolabeled with generator-produced [68Ga]Ga3+, to yield the novel PET radiotracers, [68Ga]Ga-DFO-WT and [68Ga]Ga-DFO-M74. In vitro and in vivo studies demonstrated that [68Ga]Ga-DFO-M74 exhibited a higher affinity for HER2 receptors. Biodistribution studies in mice bearing orthotopic HER2-positive breast tumors revealed a higher uptake of [68Ga]Ga-DFO-M74 in the tumor tissue, accompanied by rapid renal clearance, enabling clear delineation of tumors using PET imaging. Conversely, [68Ga]Ga-DFO-WT exhibited lower uptake and inferior image contrast compared to [68Ga]Ga-DFO-M74. Overall, the results demonstrate that the highly facile methionine-oxaziridine modification approach can be simply applied to the synthesis of stable and site-specifically modified radiolabeled antibody-chelator conjugates with favorable pharmacokinetics for PET imaging.


Asunto(s)
Inmunoconjugados , Neoplasias , Animales , Ratones , Trastuzumab/química , Radioisótopos de Galio , Metionina , Distribución Tisular , Deferoxamina/química , Tomografía de Emisión de Positrones/métodos , Quelantes/química , Racemetionina , Inmunoconjugados/química , Circonio/química , Línea Celular Tumoral
4.
Circ Res ; 127(7): 928-944, 2020 09 11.
Artículo en Inglés | MEDLINE | ID: mdl-32611235

RESUMEN

RATIONALE: The efficient resolution of tissue hemorrhage is an important homeostatic function. In human macrophages in vitro, heme activates an AMPK (AMP-activated protein kinase)/ATF1 (activating transcription factor-1) pathway that directs Mhem macrophages through coregulation of HO-1 (heme oxygenase-1; HMOX1) and lipid homeostasis genes. OBJECTIVE: We asked whether this pathway had an in vivo role in mice. METHODS AND RESULTS: Perifemoral hematomas were used as a model of hematoma resolution. In mouse bone marrow-derived macrophages, heme induced HO-1, lipid regulatory genes including LXR (lipid X receptor), the growth factor IGF1 (insulin-like growth factor-1), and the splenic red pulp macrophage gene Spic. This response was lost in bone marrow-derived macrophages from mice deficient in AMPK (Prkab1-/-) or ATF1 (Atf1-/-). In vivo, femoral hematomas resolved completely between days 8 and 9 in littermate control mice (n=12), but were still present at day 9 in mice deficient in either AMPK (Prkab1-/-) or ATF1 (Atf1-/-; n=6 each). Residual hematomas were accompanied by increased macrophage infiltration, inflammatory activation and oxidative stress. We also found that fluorescent lipids and a fluorescent iron-analog were trafficked to lipid-laden and iron-laden macrophages respectively. Moreover erythrocyte iron and lipid abnormally colocalized in the same macrophages in Atf1-/- mice. Therefore, iron-lipid separation was Atf1-dependent. CONCLUSIONS: Taken together, these data demonstrate that both AMPK and ATF1 are required for normal hematoma resolution. Graphic Abstract: An online graphic abstract is available for this article.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Factor de Transcripción Activador 1/metabolismo , Hematoma/metabolismo , Macrófagos/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Factor de Transcripción Activador 1/genética , Animales , Células Cultivadas , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Modelos Animales de Enfermedad , Eritrocitos/metabolismo , Femenino , Hematoma/genética , Hemo-Oxigenasa 1/genética , Hemo-Oxigenasa 1/metabolismo , Factor I del Crecimiento Similar a la Insulina/genética , Factor I del Crecimiento Similar a la Insulina/metabolismo , Hierro/metabolismo , Metabolismo de los Lípidos , Receptores X del Hígado/genética , Receptores X del Hígado/metabolismo , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Estrés Oxidativo , Factores de Tiempo
5.
Inorg Chem ; 61(20): 8000-8014, 2022 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-35544683

RESUMEN

N-Triphos derivatives (NP3R, R = alkyl, aryl) and asymmetric variants (NP2RXR', R' = alkyl, aryl, X = OH, NR2, NRR') are an underexplored class of tuneable, tripodal ligands in relation to the coordination chemistry of Re and Tc for biomedical applications. Mixed-ligand approaches are a flexible synthetic route to obtain Tc complexes of differing core structures and physicochemical properties. Reaction of the NP3Ph ligand with the Re(V) oxo precursor [ReOCl3(PPh3)2] generated the bidentate complex [ReOCl3(κ2-NP2PhOHAr)], which possesses an unusual AA'BB'XX' spin system with a characteristic second-order NMR lineshape that is sensitive to the bi- or tridentate nature of the coordinating diphosphine unit. The use of the asymmetric NP2PhOHAr ligand resulted in the formation of both bidentate and tridentate products depending on the presence of base. The tridentate Re(V) complex [ReOCl2(κ3-NP2PhOAr)] has provided the basis of a new reactive "metal-fragment" for further functionalization in [3 + 2] mixed-ligand complexes. The synthesis of [3 + 2] complexes with catechol-based π-donors could also be achieved under one-pot, single-step conditions from Re(V) oxo precursors. Analogous complexes can also be synthesized from suitable 99Tc(V) precursors, and these complexes have been shown to exhibit highly similar structural properties through spectroscopic and chromatographic analysis. However, a tendency for the {MVO}3+ core to undergo hydrolysis to the {MVO2}+ core has been observed both in the case of M = Re and markedly for M = 99Tc complexes. It is likely that controlling this pathway will be critical to the generation of further stable Tc(V) derivatives.


Asunto(s)
Fosfinas , Ligandos , Espectroscopía de Resonancia Magnética , Fosfinas/química
6.
Mol Ther ; 29(7): 2239-2252, 2021 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-33744469

RESUMEN

MicroRNAs (miRNAs) regulate gene expression by post-transcriptional inhibition of target genes. Proangiogenic small extracellular vesicles (sEVs; popularly identified with the name "exosomes") with a composite cargo of miRNAs are secreted by cultured stem cells and present in human biological fluids. Lipid nanoparticles (LNPs) represent an advanced platform for clinically approved delivery of RNA therapeutics. In this study, we aimed to (1) identify the miRNAs responsible for sEV-induced angiogenesis; (2) develop the prototype of bioinspired "artificial exosomes" (AEs) combining LNPs with a proangiogenic miRNA, and (3) validate the angiogenic potential of the bioinspired AEs. We previously reported that human sEVs from bone marrow (BM)-CD34+ cells and pericardial fluid (PF) are proangiogenic. Here, we have shown that sEVs secreted from saphenous vein pericytes and BM mesenchymal stem cells also promote angiogenesis. Analysis of miRNA datasets available in-house or datamined from GEO identified the let-7 family as common miRNA signature of the proangiogenic sEVs. LNPs with either hsa-let-7b-5p or cyanine 5 (Cy5)-conjugated Caenorhabditis elegans miR-39 (Cy5-cel-miR-39; control miRNA) were prepared using microfluidic micromixing. let-7b-5p-AEs did not cause toxicity and transferred functionally active let-7b-5p to recipient endothelial cells (ECs). let-7b-AEs also improved EC survival under hypoxia and angiogenesis in vitro and in vivo. Bioinspired proangiogenic AEs could be further developed into innovative nanomedicine products targeting ischemic diseases.


Asunto(s)
Exosomas/metabolismo , Vesículas Extracelulares/metabolismo , Liposomas/química , MicroARNs/metabolismo , Nanopartículas/química , Neovascularización Fisiológica , Líquido Pericárdico/fisiología , Animales , Exosomas/genética , Vesículas Extracelulares/genética , Células Endoteliales de la Vena Umbilical Humana , Humanos , Técnicas In Vitro , Ratones , MicroARNs/genética
7.
J Public Health (Oxf) ; 44(4): e548-e556, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-35020940

RESUMEN

BACKGROUND: Many public health experts have claimed that elimination strategies of pandemic response allow 'normal social life' to resume. Recognizing that social connections and feelings of normality are important for public health, this study examines whether, and for whom, that goal is realized, and identifies obstacles that may inhibit its achievement. METHODS: Thematic analysis of narratives obtained via a qualitative cross-sectional survey of a community cohort in Aotearoa | New Zealand. RESULTS: A majority of participants reported that life after elimination was 'more or less the same' as before the pandemic. Some became more social. Nevertheless, a sizeable minority reported being less social, even many months after elimination. Key obstacles to social recovery included fears that the virus was circulating undetected and the enduring impact of lockdowns upon social relationships, personal habits and mental health. Within our sample, old age and underlying health conditions were both associated with a propensity to become less social. CONCLUSIONS: Elimination strategies can successfully allow 'normal social life' to resume. However, this outcome is not guaranteed. People may encounter difficulties with re-establishing social connections in Zero-COVID settings. Measures designed to overcome such obstacles should be an integral part of elimination strategies.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Estudios Transversales , Nueva Zelanda/epidemiología , COVID-19/epidemiología , COVID-19/prevención & control , Control de Enfermedades Transmisibles
8.
J Clin Child Adolesc Psychol ; 51(5): 726-739, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-33492172

RESUMEN

OBJECTIVE: Behavioral parent training (BPT) is the first line of treatment for preschool-aged children with attention-deficit hyperactivity disorder (ADHD); however, clinically significant improvements are not universal. In the current study, we employ a person-centered approach to create subgroups of families based on the intersection of multiple parent, child, and family pre-treatment factors. Further, we explore the utility of pre-treatment family profiles in predicting post-treatment differences in observed parenting behavior (i.e., behavioral control, parental warmth) and clinically significant change in child ADHD and oppositional symptoms. METHOD: Longitudinal data were collected using observational and parent-, teacher- and clinician-reported assessments from 130 parent-child dyads (Mage= 3.57, range = 3.0- 4.11, 73.8% male, 69.2% White, 25.6% Hispanic) participating in BPT. RESULTS: Findings from the current study suggest three distinct family profiles, which consisted of one profile with high family stress (HFS) as evidenced by elevated symptomatology across parent, child, and family-level domains, a second profile with elevated parental anxiety (PA), and a final profile with elevated parental depression (PD). These family-centered profiles were differentially associated with changes in observed parenting practices. Specifically, the PD profile (39%) demonstrated minimal improvements in behavioral control and warmth following treatment. In contrast, the HFS profile (30%) only improved in behavioral control and the PA profile (31%) improved in both parenting domains following treatment. In addition, marginally significant differences in child oppositional and ADHD symptoms were observed across profiles. CONCLUSIONS: Family-centered approaches may be useful for selecting and implementing interventions.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Responsabilidad Parental , Trastorno por Déficit de Atención con Hiperactividad/diagnóstico , Terapia Conductista , Preescolar , Femenino , Humanos , Masculino , Responsabilidad Parental/psicología , Padres/psicología , Instituciones Académicas
9.
Proc Natl Acad Sci U S A ; 116(52): 26614-26624, 2019 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-31822610

RESUMEN

Epstein-Barr nuclear antigen 1 (EBNA1) plays a vital role in the maintenance of the viral genome and is the only viral protein expressed in nearly all forms of Epstein-Barr virus (EBV) latency and EBV-associated diseases, including numerous cancer types. To our knowledge, no specific agent against EBV genes or proteins has been established to target EBV lytic reactivation. Here we report an EBNA1- and Zn2+-responsive probe (ZRL5P4) which alone could reactivate the EBV lytic cycle through specific disruption of EBNA1. We have utilized the Zn2+ chelator to further interfere with the higher order of EBNA1 self-association. The bioprobe ZRL5P4 can respond independently to its interactions with Zn2+ and EBNA1 with different fluorescence changes. It can selectively enter the nuclei of EBV-positive cells and disrupt the oligomerization and oriP-enhanced transactivation of EBNA1. ZRL5P4 can also specifically enhance Dicer1 and PML expression, molecular events which had been reported to occur after the depletion of EBNA1 expression. Importantly, we found that treatment with ZRL5P4 alone could reactivate EBV lytic induction by expressing the early and late EBV lytic genes/proteins. Lytic induction is likely mediated by disruption of EBNA1 oligomerization and the subsequent change of Dicer1 expression. Our probe ZRL5P4 is an EBV protein-specific agent that potently reactivates EBV from latency, leading to the shrinkage of EBV-positive tumors, and our study also suggests the association of EBNA1 oligomerization with the maintenance of EBV latency.

10.
J Am Chem Soc ; 143(17): 6460-6469, 2021 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-33845576

RESUMEN

Heme oxygenase-1 (HO-1) is a vital enzyme in humans that primarily regulates free heme concentrations. The overexpression of HO-1 is commonly associated with cardiovascular and neurodegenerative diseases including atherosclerosis and ischemic stroke. Currently, there are no known chemical probes to detect HO-1 activity, limiting its potential as an early diagnostic/prognostic marker in these serious diseases. Reported here are the design, synthesis, and photophysical and biological characterization of a coumarin-porphyrin FRET break-apart probe to detect HO-1 activity, Fe-L1. We designed Fe-L1 to "break-apart" upon HO-1-catalyzed porphyrin degradation, perturbing the efficient FRET mechanism from a coumarin donor to a porphyrin acceptor fluorophore. Analysis of HO-1 activity using Escherichia coli lysates overexpressing hHO-1 found that a 6-fold increase in emission intensity at 383 nm was observed following incubation with NADPH. The identities of the degradation products following catabolism were confirmed by MALDI-MS and LC-MS, showing that porphyrin catabolism was regioselective at the α-position. Finally, through the analysis of Fe-L2, we have shown that close structural analogues of heme are required to maintain HO-1 activity. It is anticipated that this work will act as a foundation to design and develop new probes for HO-1 activity in the future, moving toward applications of live fluorescent imaging.


Asunto(s)
Cumarinas/química , Transferencia Resonante de Energía de Fluorescencia/métodos , Hemo-Oxigenasa 1/química , Protoporfirinas/química , Escherichia coli/enzimología , Escherichia coli/genética , Hemo-Oxigenasa 1/análisis , Hemo-Oxigenasa 1/genética , Hemo-Oxigenasa 1/metabolismo , Humanos , Procesos Fotoquímicos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Espectrofotometría Ultravioleta
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