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1.
J Invest Dermatol ; 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38582367

RESUMEN

Chronic non-healing wounds negatively impact quality of life and are a significant financial drain on health systems. The risk of infection that exacerbates comorbidities in patients necessitates regular application of wound care. Understanding the mechanisms underlying impaired wound healing are therefore a key priority to inform effective new-generation treatments. In this study, we demonstrate that 14-3-3-mediated suppression of signaling through ROCK is a critical mechanism that inhibits the healing of diabetic wounds. Accordingly, pharmacological inhibition of 14-3-3 by topical application of the sphingo-mimetic drug RB-11 to diabetic wounds on a mouse model of type II diabetes accelerated wound closure more than 2-fold than vehicle control, phenocopying our previous observations in 14-3-3ζ-knockout mice. We also demonstrate that accelerated closure of the wounded epidermis by 14-3-3 inhibition causes enhanced signaling through the Rho-ROCK pathway and that the underlying cellular mechanism involves the efficient recruitment of dermal fibroblasts into the wound and the rapid production of extracellular matrix proteins to re-establish the injured dermis. Our observations that the 14-3-3/ROCK inhibitory axis characterizes impaired wound healing and that its suppression facilitates fibroblast recruitment and accelerated re-epithelialization suggest new possibilities for treating diabetic wounds by pharmacologically targeting this axis.

2.
J Nat Prod ; 87(4): 639-651, 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38477310

RESUMEN

Cannabichromene (CBC) is a nonpsychoactive phytocannabinoid well-known for its wide-ranging health advantages. However, there is limited knowledge regarding its human metabolism following CBC consumption. This research aimed to explore the metabolic pathways of CBC by various human liver cytochrome P450 (CYP) enzymes and support the outcomes using in vivo data from mice. The results unveiled two principal CBC metabolites generated by CYPs: 8'-hydroxy-CBC and 6',7'-epoxy-CBC, along with a minor quantity of 1″-hydroxy-CBC. Notably, among the examined CYPs, CYP2C9 demonstrated the highest efficiency in producing these metabolites. Moreover, through a molecular dynamics simulation spanning 1 µs, it was observed that CBC attains stability at the active site of CYP2J2 by forming hydrogen bonds with I487 and N379, facilitated by water molecules, which specifically promotes the hydroxy metabolite's formation. Additionally, the presence of cytochrome P450 reductase (CPR) amplified CBC's binding affinity to CYPs, particularly with CYP2C8 and CYP3A4. Furthermore, the metabolites derived from CBC reduced cytokine levels, such as IL6 and NO, by approximately 50% in microglia cells. This investigation offers valuable insights into the biotransformation of CBC, underscoring the physiological importance and the potential significance of these metabolites.


Asunto(s)
Cannabinoides , Sistema Enzimático del Citocromo P-450 , Humanos , Sistema Enzimático del Citocromo P-450/metabolismo , Ratones , Animales , Cannabinoides/metabolismo , Estructura Molecular , Simulación de Dinámica Molecular , Masculino , Citocromo P-450 CYP2C9/metabolismo
3.
Growth Factors ; : 1-13, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38299881

RESUMEN

Breast cancer represents a collection of pathologies with different molecular subtypes, histopathology, risk factors, clinical behavior, and responses to treatment. "Basal-like" breast cancers predominantly lack the receptors for estrogen and progesterone (ER/PR), lack amplification of human epidermal growth factor receptor 2 (HER2) but account for 10-15% of all breast cancers, are largely insensitive to targeted treatment and represent a disproportionate number of metastatic cases and deaths. Analysis of interleukin (IL)-3 and the IL-3 receptor subunits (IL-3RA + CSF2RB) reveals elevated expression in predominantly the basal-like group. Further analysis suggests that IL-3 itself, but not the IL-3 receptor subunits, associates with poor patient outcome. Histology on patient-derived xenografts supports the notion that breast cancer cells are a significant source of IL-3 that may promote disease progression. Taken together, these observations suggest that IL-3 may be a useful marker in solid tumors, particularly triple negative breast cancer, and warrants further investigation into its contribution to disease pathogenesis.

4.
J Allergy Clin Immunol ; 153(3): 672-683.e6, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37931708

RESUMEN

BACKGROUND: Patients with severe asthma can present with eosinophilic type 2 (T2), neutrophilic, or mixed inflammation that drives airway remodeling and exacerbations and represents a major treatment challenge. The common ß (ßc) receptor signals for 3 cytokines, GM-CSF, IL-5, and IL-3, which collectively mediate T2 and neutrophilic inflammation. OBJECTIVE: To determine the pathogenesis of ßc receptor-mediated inflammation and remodeling in severe asthma and to investigate ßc antagonism as a therapeutic strategy for mixed granulocytic airway disease. METHODS: ßc gene expression was analyzed in bronchial biopsy specimens from patients with mild-to-moderate and severe asthma. House dust mite extract and Aspergillus fumigatus extract (ASP) models were used to establish asthma-like pathology and airway remodeling in human ßc transgenic mice. Lung tissue gene expression was analyzed by RNA sequencing. The mAb CSL311 targeting the shared cytokine binding site of ßc was used to block ßc signaling. RESULTS: ßc gene expression was increased in patients with severe asthma. CSL311 potently reduced lung neutrophils, eosinophils, and interstitial macrophages and improved airway pathology and lung function in the acute steroid-resistant house dust mite extract model. Chronic intranasal ASP exposure induced airway inflammation and fibrosis and impaired lung function that was inhibited by CSL311. CSL311 normalized the ASP-induced fibrosis-associated extracellular matrix gene expression network and strongly reduced signatures of cellular inflammation in the lung. CONCLUSIONS: ßc cytokines drive steroid-resistant mixed myeloid cell airway inflammation and fibrosis. The anti-ßc antibody CSL311 effectively inhibits mixed T2/neutrophilic inflammation and severe asthma-like pathology and reverses fibrosis gene signatures induced by exposure to commonly encountered environmental allergens.


Asunto(s)
Asma , Receptores de Citocinas , Ratones , Animales , Humanos , Receptores de Citocinas/metabolismo , Remodelación de las Vías Aéreas (Respiratorias) , Pulmón , Citocinas/metabolismo , Ratones Transgénicos , Inflamación , Alérgenos , Esteroides/uso terapéutico , Fibrosis , Pyroglyphidae
5.
Eur J Endocrinol ; 190(1): 62-74, 2024 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-38033321

RESUMEN

OBJECTIVE: Metabolic profiling is a valuable tool to characterize tumor biology but remains largely unexplored in neuroendocrine tumors (NETs). Our aim was to comprehensively assess the metabolomic profile of NETs and identify novel prognostic biomarkers and dysregulated molecular pathways. DESIGN AND METHODS: Multiplatform untargeted metabolomic profiling (GC-MS, CE-MS, and LC-MS) was performed in plasma from 77 patients with G1-2 extra-pancreatic NETs enrolled in the AXINET trial (NCT01744249) (study cohort) and from 68 non-cancer individuals (control). The prognostic value of each differential metabolite (n = 155) in NET patients (P < .05) was analyzed by univariate and multivariate analyses adjusted for multiple testing and other confounding factors. Related pathways were explored by Metabolite Set Enrichment Analysis (MSEA) and Metabolite Pathway Analysis (MPA). RESULTS: Thirty-four metabolites were significantly associated with progression-free survival (PFS) (n = 16) and/or overall survival (OS) (n = 27). Thirteen metabolites remained significant independent prognostic factors in multivariate analysis, 3 of them with a significant impact on both PFS and OS. Unsupervised clustering of these 3 metabolites stratified patients in 3 distinct prognostic groups (1-year PFS of 71.1%, 47.7%, and 15.4% (P = .012); 5-year OS of 69.7%, 32.5%, and 27.7% (P = .003), respectively). The MSEA and MPA of the 13-metablolite signature identified methionine, porphyrin, and tryptophan metabolisms as the 3 most relevant dysregulated pathways associated with the prognosis of NETs. CONCLUSIONS: We identified a metabolomic signature that improves prognostic stratification of NET patients beyond classical prognostic factors for clinical decisions. The enriched metabolic pathways identified reveal novel tumor vulnerabilities that may foster the development of new therapeutic strategies for these patients.


Asunto(s)
Tumores Neuroendocrinos , Porfirinas , Humanos , Metabolómica , Metionina/uso terapéutico , Tumores Neuroendocrinos/patología , Porfirinas/uso terapéutico , Triptófano , Estudios de Casos y Controles
6.
Adv Sci (Weinh) ; 11(9): e2307766, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38103011

RESUMEN

Materials properties are determined by their compositions and structures. In ABO3 oxides different cation orderings lead to mainly perovskite- or corundum like derivatives with exciting physical properties. Sometimes, a material can be stabilized in more than one structural modification, providing a unique opportunity to explore structure-properties relationship. Here, CoVO3 obtained in both ilmenite-(CoVO3 -I) and LiNbO3 -type (CoVO3 -II) polymorphs at moderate (8-12 GPa) and high pressures (22 GPa), respectively are presented. Their distinctive cation distributions affect drastically the magnetic properties as CoVO3 -II shows a cluster-glass behavior while CoVO3 -I hosts a honeycomb zigzag magnetic structure in the cobalt network. First principles calculations show that the influence of vanadium is crucial for CoVO3 -I, although it is previously considered as non-magnetic in a dimerized spin-singlet state. Contrarily, CoVO3 -II shows two independent interpenetrating antiferromagnetic Co- and ferromagnetic V-hcp sublattices, which intrinsically frustrate any possible magnetic order. CoVO3 -II is also remarkable as the first oxide crystallizing with the LiNbO3 -type structure where both metals contain free d electrons. CoVO3 polymorphs pinpoint therefore as well to a much broader phase field of high-pressure A-site Cobaltites.

7.
Artículo en Inglés | MEDLINE | ID: mdl-38096641

RESUMEN

Chemoreception through odorant receptors (ORs), ionotropic receptors (IRs) and gustatory receptors (GRs) represents the functions of key proteins in the chemical ecology of insects. Recent studies have identified chemoreceptors in coleopterans, facilitating the evolutionary analysis of not only ORs but also IRs and GRs. Thus, Cerambycidae, Tenebrionidae and Curculionidae have received increased attention. However, knowledge of the chemoreceptors from Scarabaeidae is still limited, particularly for those that are sympatric. Considering the roles of chemoreceptors, this analysis could shed light on evolutionary processes in the context of sympatry. Therefore, the aim of this study was to identify and compare the repertoires of ORs, GRs and IRs between two sympatric scarab beetles, Hylamorpha elegans and Brachysternus prasinus. Here, construction of the antennal transcriptomes of both scarab beetle species and analyses of their phylogeny, molecular evolution and relative expression were performed. Thus, 119 new candidate chemoreceptors were identified for the first time, including 17 transcripts for B. prasinus (1 GR, 3 IRs and 13 ORs) and 102 for H. elegans (22 GRs, 14 IRs and 66 ORs). Orthologs between the two scarab beetle species were found, revealing specific expansions as well as absence in some clades. Purifying selection appears to have occurred on H. elegans and B. prasinus ORs. Further efforts will be focused on target identification to characterize kairomone and/or pheromone receptors.


Asunto(s)
Escarabajos , Receptores Odorantes , Gorgojos , Animales , Transcriptoma , Simpatría , Perfilación de la Expresión Génica , Escarabajos/genética , Escarabajos/metabolismo , Gorgojos/genética , Filogenia , Receptores Odorantes/genética , Receptores Odorantes/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Antenas de Artrópodos/metabolismo
8.
Transl Psychiatry ; 13(1): 403, 2023 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-38123552

RESUMEN

ANK3 is a leading bipolar disorder (BD) candidate gene in humans and provides a unique opportunity for studying epilepsy-BD comorbidity. Previous studies showed that deletion of Ank3-1b, a BD-associated variant of Ank3 in mice leads to increased firing threshold and diminished action potential dynamic range of parvalbumin (PV) interneurons and absence epilepsy, thus providing a biological mechanism linking epilepsy and BD. To explore the behavioral overlap of these disorders, we characterized behavioral patterns of Ank3-1b KO mice during overnight home-cage activity and examined network activity during these behaviors using paired video and EEG recordings. Since PV interneurons contribute to the generation of high-frequency gamma oscillations, we anticipated changes in the power of neocortical EEG signals in the gamma frequency range (> 25 Hz) during behavioral states related to human BD symptoms, including abnormal sleep, hyperactivity, and repetitive behaviors. Ank3-1b KO mice exhibited an overall increase in slow gamma (~25-45 Hz) power compared to controls, and slow gamma power correlated with seizure phenotype severity across behaviors. During sleep, increased slow gamma power correlated with decreased time spent in the rapid eye movement (REM) stage of sleep. Seizures were more common during REM sleep compared to non-REM (NREM) sleep. We also found that Ank3-1b KO mice were hyperactive and exhibited a repetitive behavior phenotype that co-occurred with increased slow gamma power. Our results identify a novel EEG biomarker associating Ank3 genetic variation with BD and epilepsy and suggest modulation of gamma oscillations as a potential therapeutic target.


Asunto(s)
Trastorno Bipolar , Epilepsia , Neocórtex , Animales , Humanos , Ratones , Trastorno Bipolar/genética , Comorbilidad , Electroencefalografía , Epilepsia/genética , Neocórtex/fisiología , Convulsiones , Sueño/fisiología
9.
Chem Commun (Camb) ; 59(88): 13199-13202, 2023 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-37853795

RESUMEN

Novel SrMn3Ti14M4O38 (M = Ti and Fe) compounds with a crichtonite-type structure are reported herein. M = Ti shows a ferrimagnetic behavior at TN = 15 K, while M = Fe creates a ferromagnetic cluster-glass at Tf = 8 K via positional disorder. This family offers a promising magnetic playground.

11.
Small Methods ; 7(11): e2300491, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37490517

RESUMEN

The design of high-density non-volatile memories is a long-standing dream, limited by conventional storage "0" or "1" bits. An alternative paradigm exists in which regions within candidate materials can be magnetized to intermediate values between the saturation limits. In principle, this paves the way to multivalued bits, vastly increasing storage density. Single-molecule magnets, are good examples offering transitions between intramolecular quantum levels, but require ultra-low temperatures and limited relaxation time between magnetization states. It is showed here that the quasi 2D-Ising compound BaFe2 (PO4 )2 overcomes these limitations. The combination of giant magneto-crystalline anisotropy, strong ferromagnetic exchange, and strong intrinsic pinning creates remarkably narrow magnetic domain walls, collectively freezing under Tf ≈15 K. This results in a transition from a soft to a super-hard magnet (coercive force > 14 T). Any magnetization can then be printed and robustly protected from external fields with an energy barrier >9T at 2 K.

12.
Blood Cancer Discov ; 4(5): 352-364, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37498362

RESUMEN

Selective inhibitors of Janus kinase (JAK) 2 have been in demand since the discovery of the JAK2 V617F mutation present in patients with myeloproliferative neoplasms (MPN); however, the structural basis of V617F oncogenicity has only recently been elucidated. New structural studies reveal a role for other JAK2 domains, beyond the kinase domain, that contribute to pathogenic signaling. Here we evaluate the structure-based approaches that led to recently-approved type I JAK2 inhibitors (fedratinib and pacritinib), as well as type II (BBT594 and CHZ868) and pseudokinase inhibitors under development (JNJ7706621). With full-length JAK homodimeric structures now available, superior selective and mutation-specific JAK2 inhibitors are foreseeable. SIGNIFICANCE: The JAK inhibitors currently used for the treatment of MPNs are effective for symptom management but not for disease eradication, primarily because they are not strongly selective for the mutant clone. The rise of computational and structure-based drug discovery approaches together with the knowledge of full-length JAK dimer complexes provides a unique opportunity to develop better targeted therapies for a range of conditions driven by pathologic JAK2 signaling.


Asunto(s)
Inhibidores de las Cinasas Janus , Trastornos Mieloproliferativos , Neoplasias , Humanos , Inhibidores de las Cinasas Janus/uso terapéutico , Trastornos Mieloproliferativos/tratamiento farmacológico , Trastornos Mieloproliferativos/genética , Mutación , Descubrimiento de Drogas , Janus Quinasa 2/genética
13.
Front Psychol ; 14: 1160466, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37287786

RESUMEN

Stress is a public health disease that is increasing rapidly in the population worldwide, so it is necessary to take measures for detection and evaluation, through short scales. The purpose of the study was to analyze the psychometric properties of the Perceived Stress Scale (PSS) in a sample made up of 752 people with an age range of 18 to 62 years (M = 30.18, DE = 10.175), of whom 44% (331) were women and 56% (421) men, from Lima, Peru. The results, by means of confirmatory factor analysis and the Rasch model, confirmed the global adjustment of a 12-item (PSS-12) version with the presence of two orthogonal factors independent of each other, and also demonstrated the metric equivalence according to gender and adequate internal consistency. These results allow us to recommend the use of the PSS-12 in the Peruvian population for the measurement of stress.

14.
Rev. senol. patol. mamar. (Ed. impr.) ; 36(2)abr.-jun. 2023. tab
Artículo en Español | IBECS | ID: ibc-223848

RESUMEN

A pesar de utilizar criterios histológicos e inmunohistoquímicos, no somos capaces de reflejar la heterogeneidad del cáncer de mama. En 2012 se realiza el estudio Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), el cual analiza la arquitectura genómica y de transcripción en 2000 cánceres de mama. Aparecieron subtipos moleculares con gran implicación. Tal es la importancia de la biología molecular que, en el AJCC-TNM8 (2017), se incorporaron grupos pronósticos con base en la expresión de biomarcadores (RE, RP, HER2, Ki67). Estos grupos complementan a la clasificación tradicional y añade un enfoque biológico al puramente anatómico existente. Hemos analizado el estudio METABRIC, haciendo hincapié en la nueva línea de investigación que aportó. Realizamos una exhaustiva búsqueda bibliográfica en las principales bases de datos, obteniendo los artículos que exponen los resultados del METABRIC. Desglosamos los 10 grupos integradores descubiertos recientemente, sus variaciones genéticas y su implicación para nuestra práctica clínica. Comprobamos que la clasificación actual del cáncer de mama no es lo suficientemente precisa, cuyas incongruencias se explican por los grupos integradores. Sientan los cimientos para una nueva clasificación o para refinar los subtipos existentes. (AU)


Despite using histological and immunohistochemical criteria, we are unable to reflect the heterogeneity of breast cancer. In 2012 METABRIC analyzed the genomic and transcriptional architecture of 2000 breast cancers. Molecular subtypes were found to be highly implicated. Such is the importance of molecular biology that, in AJCC-TNM8 (2017), prognostic groups based on biomarker expression (ER, PR, HER2, and Ki67) were incorporated. These groups complement the traditional classification and add a biological approach to the existing purely anatomical one. We have analyzed the METABRIC study, emphasizing the new line of research it contributed. We did an exhaustive literature search in the main databases, obtaining the articles presenting the METABRIC results. We broke down the 10 recently discovered integrative clusters, their genetic variations and their implication for our clinical practice. We found that the current classification of breast cancer is not enough accurate, the inconsistencies of which are explained by the integrative clusters. They lay the foundation for a new classification or for refining existing subtypes. (AU)


Asunto(s)
Humanos , Femenino , Neoplasias de la Mama/clasificación , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Inmunohistoquímica , Biología Molecular
15.
Cancer Discov ; 13(8): 1922-1947, 2023 08 04.
Artículo en Inglés | MEDLINE | ID: mdl-37191437

RESUMEN

Leukemia stem cells (LSC) possess distinct self-renewal and arrested differentiation properties that are responsible for disease emergence, therapy failure, and recurrence in acute myeloid leukemia (AML). Despite AML displaying extensive biological and clinical heterogeneity, LSC with high interleukin-3 receptor (IL3R) levels are a constant yet puzzling feature, as this receptor lacks tyrosine kinase activity. Here, we show that the heterodimeric IL3Rα/ßc receptor assembles into hexamers and dodecamers through a unique interface in the 3D structure, where high IL3Rα/ßc ratios bias hexamer formation. Importantly, receptor stoichiometry is clinically relevant as it varies across the individual cells in the AML hierarchy, in which high IL3Rα/ßc ratios in LSCs drive hexamer-mediated stemness programs and poor patient survival, while low ratios mediate differentiation. Our study establishes a new paradigm in which alternative cytokine receptor stoichiometries differentially regulate cell fate, a signaling mechanism that may be generalizable to other transformed cellular hierarchies and of potential therapeutic significance. SIGNIFICANCE: Stemness is a hallmark of many cancers and is largely responsible for disease emergence, progression, and relapse. Our finding that clinically significant stemness programs in AML are directly regulated by different stoichiometries of cytokine receptors represents a hitherto unexplained mechanism underlying cell-fate decisions in cancer stem cell hierarchies. This article is highlighted in the In This Issue feature, p. 1749.


Asunto(s)
Leucemia Mieloide Aguda , Receptores de Citocinas , Humanos , Receptores de Citocinas/uso terapéutico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/tratamiento farmacológico , Fosforilación , Transducción de Señal , Proliferación Celular , Células Madre Neoplásicas
16.
J Allergy Clin Immunol ; 152(3): 725-735.e10, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37127225

RESUMEN

BACKGROUND: Mast cells (MCs) are tissue-resident immune cells that mediate IgE-dependent allergic responses. Downstream of FcεRI, an intricate network of receptor-specific signaling pathways and adaptor proteins govern MC function. The 14-3-3 family of serine-threonine phosphorylation-dependent adapter proteins are known to organize intracellular signaling. However, the role of 14-3-3 in IgE-dependent activation remains poorly defined. OBJECTIVE: We sought to determine whether 14-3-3 proteins are required for IgE-dependent MC activation and whether 14-3-3 is a viable target for the treatment of MC-mediated inflammatory diseases. METHODS: Genetic manipulation of 14-3-3ζ expression in human and mouse MCs was performed and IgE-dependent mediator release assessed. Pharmacologic inhibitors of 14-3-3 and 14-3-3ζ knockout mice were used to assess 14-3-3ζ function in a MC-dependent in vivo passive cutaneous anaphylaxis (PCA) model of allergic inflammation. Expression and function of 14-3-3ζ were assessed in human nasal polyp tissue MCs. RESULTS: IgE-dependent mediator release from human MCs was decreased by 14-3-3ζ knockdown and increased by 14-3-3ζ overexpression. Deletion of the 14-3-3ζ gene decreased IgE-dependent activation of mouse MCs in vitro and PCA responses in vivo. Furthermore, the 14-3-3 inhibitor, RB-11, which impairs dimerization of 14-3-3, inhibited cultured MC and polyp tissue MC activation and signaling downstream of the FcεRI receptor and dose-dependently attenuated PCA responses. CONCLUSION: IgE/FcεRI-mediated MC activation is positively regulated by 14-3-3ζ. We identify a critical role for this p-Ser/Thr-binding protein in the regulation of MC FcεRI signaling and IgE-dependent immune responses and show that this pathway may be amenable to pharmacologic targeting.


Asunto(s)
Anafilaxia , Receptores de IgE , Humanos , Ratones , Animales , Proteínas 14-3-3/genética , Proteínas 14-3-3/metabolismo , Mastocitos , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Inmunoglobulina E , Inflamación/metabolismo , Degranulación de la Célula
17.
Angew Chem Int Ed Engl ; 62(25): e202302049, 2023 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-37021737

RESUMEN

Phosphate tungsten and molybenum bronzes represent an outstanding class of materials displaying textbook examples of charge-density-wave (CDW) physics among other fundamental properties. Here we report on the existence of a novel structural branch with the general formula [Ba(PO4 )2 ][Wm O3m-3 ] (m=3, 4 and 5) denominated 'layered monophosphate tungsten bronzes' (L-MPTB). It results from thick [Ba(PO4 )2 ]4- spacer layers disrupting the cationic metal-oxide 2D units and enforcing an overall trigonal structure. Their symmetries are preserved down to 1.8 K and the compounds show metallic behaviour with no clear anomaly as a function of temperature. However, their electronic structure displays the characteristic Fermi surface of previous bronzes derived from 5d W states with hidden nesting properties. By analogy with previous bronzes, such a Fermi surface should result into CDW order. Evidence of CDW order was only indirectly observed in the low-temperature specific heat, giving an exotic context at the crossover between stable 2D metals and CDW order.


Asunto(s)
Frío , Tungsteno , Electrónica , Calor , Metales
18.
Materials (Basel) ; 16(4)2023 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-36837349

RESUMEN

Numerous studies expose the potential of brannerite to become a good matrix, concentrating fission products and actinides. Minerals can complement the data collected from the synthetic materials and offer an advantage of a long-time exposure to radiation. Natural metamict brannerite from Akchatau, Kazakhstan, and its annealed sample were studied by EPMA, Raman spectroscopy, TGA, DSC, XRD and HTXRD. The radioactivity of pristine and annealed samples of brannerite was measured. Brannerite from Akchatau is characterized by the absence of significant amounts of REE and yttrium. The studied brannerite regains its structure at a temperature ~650 °C, revealed by the HTXRD and DSC. HTXRD was also performed on the annealed recrystallized brannerite. The thermal expansion for brannerite has been determined for the first time. The brannerite structure expands anisotropically with temperature increase. All the thermal expansion coefficients are positive except for αß. The decreasing beta parameter indicates a "shear structural deformation". The angle between the 1st axis of the tensor and the crystallographic a axis decreases with the increase of the temperature. The structure expands mostly in the α11 direction, approaching the bisector of the ß angle. Brannerite has a low CTE at room temperature-αv = 16 × 10-6 °C-1, which increases up to 39.4 × 10-6 °C-1 at 1100 °C. In general, the thermal stability of brannerite is comparable to that of the other perspective oxide radioactive waste-immobilizing matrices (e.g., Ln2Zr2O7, CePO4, CaTiO3, CaZrTi2O7). The calculated thermal expansion of brannerite and the understanding of its underlying crystal chemical mechanisms may contribute to the behavior prediction of the material (both metamict and crystalline) at high temperatures.

19.
Environ Entomol ; 52(2): 210-216, 2023 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-36852867

RESUMEN

Anastrepha obliqua Macquart (Diptera: Tephritidae) is a polyphagous species with hog plums (Spondias spp.) (Sapindales: Anacardiaceae) and mangoes (Mangifera indica L.) (Sapindales: Anacardiaceae) as primary host fruits. In this study, the olfactory preference of A. obliqua for three stages of ripeness of two mango cultivars ('Coche' and 'Ataulfo') was investigated. The female flies were more attracted to ripe 'Coche' fruits compared to those ripe 'Ataulfo'. Further, they were more attracted to the 'Coche' half-ripe and ripe fruits than to the unripe ones, but they did not discriminate among the stages of ripeness of 'Ataulfo' fruits. The male flies did not show preference for any specific mango cultivars or ripeness stage tested. Four compounds from ripe 'Coche' mangoes, and two from ripe 'Ataulfo' fruits were identified using coupled gas chromatography-electroantennographic (GC-EAD) recording and gas chromatography-mass spectrometry (GC-MS) analysis. 'Coche' mango volatiles eliciting responses from the female antennae were ethyl butyrate, ethyl hexanoate, ethyl heptanoate, and ethyl octanoate. The two 'Ataulfo' mango volatiles were identified as 3-carene and ethyl octanoate. These compounds were absent in unripe mangoes of both cultivars. Synthetic blends of these compounds were attractive to females as mango extracts in field cage tests. Our results suggest that the olfactory preference of A. obliqua for attractive hosts is based on the presence or absence of the compounds associated with fruit maturity.


Asunto(s)
Anacardiaceae , Mangifera , Tephritidae , Femenino , Masculino , Animales , Mangifera/química , Tephritidae/fisiología , Frutas
20.
J Allergy Clin Immunol ; 151(2): 324-344, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36424209

RESUMEN

The family of cytokines that comprises IL-3, IL-5, and GM-CSF was discovered over 30 years ago, and their biological activities and resulting impact in clinical medicine has continued to expand ever since. Originally identified as bone marrow growth factors capable of acting on hemopoietic progenitor cells to induce their proliferation and differentiation into mature blood cells, these cytokines are also recognized as key mediators of inflammation and the pathobiology of diverse immunologic diseases. This increased understanding of the functional repertoire of IL-3, IL-5, and GM-CSF has led to an explosion of interest in modulating their functions for clinical management. Key to the successful clinical translation of this knowledge is the recognition that these cytokines act by engaging distinct dimeric receptors and that they share a common signaling subunit called ß-common or ßc. The structural determination of how IL-3, IL-5, and GM-CSF interact with their receptors and linking this to their differential biological functions on effector cells has unveiled new paradigms of cell signaling. This knowledge has paved the way for novel mAbs and other molecules as selective or pan inhibitors for use in different clinical settings.


Asunto(s)
Medicina Clínica , Factor Estimulante de Colonias de Granulocitos y Macrófagos , Humanos , Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Citocinas/metabolismo , Interleucina-3/metabolismo , Interleucina-5/metabolismo , Eosinófilos , Biología
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