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1.
ChemSusChem ; : e202401260, 2024 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-39167441

RESUMEN

Visible light-active photocatalysts play a crucial role in gas-phase photocatalytic CO2 reduction, offering significant potential for sustainable energy conversion. Herein, we present the synthesis of spindle-shaped Iron (Fe)-based metal-organic framework (MOF) MIL-88A, coupled with distinct α-Bi2O3 nanospheres. The α-Bi2O3/MIL88A heterostructure is formed by interacting opposite surface charges, enhancing visible-light absorption and efficient interfacial charge-carrier separation. Such low-cost photocatalysts have a 1.75 eV band gap and demonstrate enhanced efficacy in converting CO2 to CO, CH4, and H2 in water without using any sacrificial agents or noble metals compared to pristine MIL88A. In addition, in situ Electron Spin Resonance (ESR) analyses revealed that these unique catalysts combination promoted enhanced interfacial charge dynamics, creating efficient trapping sites for photogenerated carriers. Further, in-situ Diffuse Reflectance Infrared Fourier Transfer Spectroscopy (DRIFTS) investigation elucidates the plausible reaction mechanism and provides an effective methodology for catalyst screening for CO2 photoreduction. This study offers an effective approach for synthesizing the earth-abundant heterostructure from metal oxide and low-cost MOFs, enhancing photocatalytic activity for sustainable carbon dioxide conversion into invaluable chemicals.

2.
J Appl Crystallogr ; 57(Pt 4): 1067-1084, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39108823

RESUMEN

Portland cements (PCs) and cement blends are multiphase materials of different fineness, and quantitatively analysing their hydration pathways is very challenging. The dissolution (hydration) of the initial crystalline and amorphous phases must be determined, as well as the formation of labile (such as ettringite), reactive (such as portlandite) and amorphous (such as calcium silicate hydrate gel) components. The microstructural changes with hydration time must also be mapped out. To address this robustly and accurately, an innovative approach is being developed based on in situ measurements of pastes without any sample conditioning. Data are sequentially acquired by Mo Kα1 laboratory X-ray powder diffraction (LXRPD) and microtomography (µCT), where the same volume is scanned with time to reduce variability. Wide capillaries (2 mm in diameter) are key to avoid artefacts, e.g. self-desiccation, and to have excellent particle averaging. This methodology is tested in three cement paste samples: (i) a commercial PC 52.5 R, (ii) a blend of 80 wt% of this PC and 20 wt% quartz, to simulate an addition of supplementary cementitious materials, and (iii) a blend of 80 wt% PC and 20 wt% limestone, to simulate a limestone Portland cement. LXRPD data are acquired at 3 h and 1, 3, 7 and 28 days, and µCT data are collected at 12 h and 1, 3, 7 and 28 days. Later age data can also be easily acquired. In this methodology, the amounts of the crystalline phases are directly obtained from Rietveld analysis and the amorphous phase contents are obtained from mass-balance calculations. From the µCT study, and within the attained spatial resolution, three components (porosity, hydrated products and unhydrated cement particles) are determined. The analyses quantitatively demonstrate the filler effect of quartz and limestone in the hydration of alite and the calcium aluminate phases. Further hydration details are discussed.

3.
J Appl Crystallogr ; 57(Pt 2): 509-528, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38596722

RESUMEN

INSIGHT is a Python-based software tool for processing and reducing 2D grazing-incidence wide- and small-angle X-ray scattering (GIWAXS/GISAXS) data. It offers the geometric transformation of the 2D GIWAXS/GISAXS detector image to reciprocal space, including vectorized and parallelized pixel-wise intensity correction calculations. An explicit focus on efficient data management and batch processing enables full control of large time-resolved synchrotron and laboratory data sets for a detailed analysis of kinetic GIWAXS/GISAXS studies of thin films. It processes data acquired with arbitrarily rotated detectors and performs vertical, horizontal, azimuthal and radial cuts in reciprocal space. It further allows crystallographic indexing and GIWAXS pattern simulation, and provides various plotting and export functionalities. Customized scripting offers a one-step solution to reduce, process, analyze and export findings of large in situ and operando data sets.

4.
ACS Appl Mater Interfaces ; 16(9): 11552-11560, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38408369

RESUMEN

Bismuth is a catalyst material that selectively produces formate during the electrochemical reduction of CO2. While different synthesis strategies have been employed to create electrocatalysts with better performance, the restructuring of bismuth precatalysts during the reaction has also been previously reported. The mechanism behind the change has, however, remained unclear. Here, we show that Bi2O3 nanoparticles supported on Vulcan carbon intrinsically transform into stellated nanosheet aggregates upon exposure to an electrolyte. Liquid cell transmission electron microscopy observations first revealed the gradual restructuring of the nanoparticles into nanosheets in the presence of 0.1 M KHCO3 without an applied potential. Our experiments also associated the restructuring with solubility of bismuth in the electrolyte. While the consequent agglomerates were stable under moderate negative potentials (-0.3 VRHE), they dissolved over time at larger negative potentials (-0.4 and -0.5 VRHE). Operando Raman spectra collected during the reaction showed that under an applied potential, the oxide particles reduced to metallic bismuth, thereby confirming the metal as the working phase for producing formate. These results inform us about the working morphology of these electrocatalysts and their formation and degradation mechanisms.

5.
J Dent ; 142: 104874, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38307488

RESUMEN

OBJECTIVES: This study evaluated the resistance of S-PRG (Surface Pre-Reacted Glass-ionomer) composites and other restorative materials against erosive and abrasive challenges and their protective effect on enamel adjacent to the restorations. MATERIALS AND METHODS: Bovine enamel blocks were prepared and randomized into 12 groups, including 6 types of material, each of them subjected to erosion_e or erosion+abrasion_ea: Beautifil II (S-PRG); Beautifil Bulk Restorative (S-PRG); Filtek Z250 XT; Filtek Bulk Fill; EQUIA Forte; Riva Light Cure. Cavities were prepared in the middle of enamel blocks and restored with the materials. Initial profiling measurement was performed on the material and on adjacent enamel (100, 200, 300, 600 and 700 µm from the restoration margin). Palatal intraoral appliances with the restored enamel blocks were used by the volunteers (n = 10). During 5 days appliances were immersed in 2.5 % citric acid for 2 min; 6 × /day (erosion_e). For ea condition, blocks were brushed for 1 min after each acid immersion. Final profile assessment was performed. Data were analysed by two and three way ANOVA followed by Tukey's test (p < 0.05). RESULTS: Material wear: Riva Light Cure showed the highest wear followed by EQUIA Forte and then all resin composites, including the ones with S-PRG (p = 0.000). Enamel wear: there was significant interaction among type of restorative material, wear condition and distance (p = 0.014), enamel around materials showed similar wear (p = 0.983) and the enamel subjected to ea exhibited highest wear (p = 0.000). CONCLUSION: SPRG based composites showed resistance against erosive and abrasive challenges but were not able to protect enamel adjacent to the restorations. CLINICAL SIGNIFICANCE: S-PRG composites exhibit resistance to material wear comparable to resin composites. However, they have shown an inability to effectively protect the adjacent enamel under in situ erosive-abrasive conditions, despite the presence of mineral-loss-preventing ions surrounding materials.


Asunto(s)
Erosión de los Dientes , Animales , Bovinos , Humanos , Erosión de los Dientes/prevención & control , Materiales Dentales , Esmalte Dental , Cementos de Ionómero Vítreo , Ácido Cítrico
6.
Adv Mater ; 36(14): e2307265, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38126918

RESUMEN

Metal halide perovskite solar cells (PSCs) are infamous for their batch-to-batch and lab-to-lab irreproducibility in terms of stability and performance. Reproducible fabrication of PSCs is a critical requirement for market viability and practical commercialization. PSC irreproducibility plagues all levels of the community; from institutional research laboratories, start-up companies, to large established corporations. In this work, the critical function of atmospheric humidity to regulate the crystallization and stabilization of formamidinium lead triiodide (FAPbI3) perovskites is unraveled. It is demonstrated that the humidity content during processing induces profound variations in perovskite stoichiometry, thermodynamic stability, and optoelectronic quality. Almost counterintuitively, it is shown that the presence of humidity is perhaps indispensable to reproduce phase-stable and efficient FAPbI3-based PSCs.

7.
Plants (Basel) ; 12(16)2023 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-37631143

RESUMEN

Bryophytes play a crucial role in the ecosystem's water compartment due to their unique ability to retain water. However, their role within temperate native ecosystems is mostly unknown. To address this knowledge gap, a study was conducted on Terceira Island (Azores), focusing on 14 bryophyte species found at different altitudes (40 m, 683 m, and 1012 m); five samples were collected monthly, per species and location, and their fresh, saturated, and dry weights were examined in the laboratory; four species were collected from more than one site. Generalized linear models (GLM) were used to assert the influence of climate factors (temperature, precipitation, and relative humidity) and environmental variables on two water indicators: field water content (FWC) and relative water content (RWC). None of the examined factors, per se, were able to explain all cases. Species appear to respond to climate according to a limiting factor effect: at lower elevations, precipitation was determinant, while at medium elevations, FWC was influenced by a combination of precipitation and relative humidity. At higher elevations, temperature was retained for seven of the nine studied species. The RWC values indicated that the 14 bryophyte species remained hydrated throughout the year but rarely reached their maximum water-holding capacity, even at the highest altitude. Understanding the mechanisms by which native bryophytes acquire, store, and release water is crucial for comprehending the resilience of native vegetation in the face of climate change. This knowledge can also enable the development of strategies to mitigate the effects of climate change and protect vital water resources.

8.
J Synchrotron Radiat ; 30(Pt 1): 192-199, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36601937

RESUMEN

The investigation of lithium-ion battery failures is a major challenge for personnel and equipment due to the associated hazards (thermal reaction, toxic gases and explosions). To perform such experiments safely, a battery abuse-test chamber has been developed and installed at the microtomography beamline ID19 of the European Synchrotron Radiation Facility (ESRF). The chamber provides the capability to robustly perform in situ abuse tests through the heat-resistant and gas-tight design for flexible battery geometries and configurations, including single-cell and multi-cell assemblies. High-speed X-ray imaging can be complemented by supplementary equipment, including additional probes (voltage, pressure and temperature) and thermal imaging. Together with the test chamber, a synchronization graphical user interface was developed, which allows an initial interpretation by time-synchronous visualization of the acquired data. Enabled by this setup, new meaningful insights can be gained into the internal processes of a thermal runaway of current and future energy-storage devices such as lithium-ion cells.

9.
Materials (Basel) ; 14(20)2021 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-34683794

RESUMEN

Pharmaceutical active compounds, including hundreds of different substances, are counted among the emerging contaminants in waterbodies, whose presence raises a growing concern for the ecosystem. Drugs are metabolized and excreted mainly through urine as an unchanged active ingredient or in the form of metabolites. These emerging contaminants are not effectively removed with the technologies currently in use, making them a relevant environmental problem. This study proposes the treatment of urine and water at the source that can allow an easier removal of dissolved drugs and metabolites. The treatment of synthetic urine, with dissolved ibuprofen as a model compound, by adsorption, using various classes of inorganic materials, such as clays, hierarchical zeolites and ordered mesoporous silica (MCM-41), is presented. A multi-technique approach involving X-ray powder diffraction, solid-state NMR, UV-Vis and Raman spectroscopies was employed to investigate the adsorption process in inorganic adsorbents. Moreover, the uptake, the ensuing competition, the efficiency and selectivity as well as the packing of the model compound in ordered mesoporous silica during the incipient wetness impregnation process were all thoroughly monitored by a novel approach, involving combined complementary time-resolved in situ 1H and 13C MAS NMR spectroscopy as well as X-ray powder diffraction.

10.
J Synchrotron Radiat ; 28(Pt 5): 1504-1510, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-34475297

RESUMEN

A prototype in situ X-ray absorption near-edge structure (XANES) system was developed to explore its sensitivity for ultra-thin films of iron-nitride (Fe-N), cobalt-nitride (Co-N) and nickel-nitride (Ni-N). They were grown using DC-magnetron sputtering in the presence of an N2 plasma atmosphere at the experimental station of the soft XAS beamline BL01 (Indus-2, RRCAT, India). XANES measurements were performed at the N K-edge in all three cases. It was found that the N K-edge spectral shape and intensity are greatly affected by increasing thickness and appear to be highly sensitive, especially in low-thickness regions. From a certain thickness of ∼1000 Å, however, samples exhibit a bulk-like behavior. On the basis of the obtained results, different growth stages were identified. Furthermore, the presence of a molecular N2 component in the ultra-thin regime (<100 Å) was also obtained in all three cases studied in this work. In essence, this prototype in situ system reveals that N K-edge XANES is a powerful technique for studying ultra-thin films, and the development of a dedicated in situ system can be effective in probing several phenomena that remain hitherto unexplored in such types of transition metal nitride thin films.

11.
Angew Chem Int Ed Engl ; 60(37): 20407-20416, 2021 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-34056798

RESUMEN

The combination of in situ pair distribution function (PDF) analysis and small-angle X-ray scattering (SAXS) enables analysis of the formation mechanism of metal oxido nanoclusters and cluster-solvent interactions as they take place. Herein, we demonstrate the method for the formation of clusters with a [Bi38 O45 ] core. Upon dissolution of crystalline [Bi6 O5 (OH)3 (NO3 )5 ]⋅3 H2 O in DMSO, an intermediate rapidly forms, which slowly grows to stable [Bi38 O45 ] clusters. To identify the intermediate, we developed an automated modeling method, where smaller [Bix Oy ] structures based on the [Bi38 O45 ] framework are tested against the data. [Bi22 O26 ] was identified as the main intermediate species, illustrating how combined PDF and SAXS analysis is a powerful tool to gain insight into nucleation on an atomic scale. PDF also provides information on the interaction between nanoclusters and solvent, which is shown to depend on the nature of the ligands on the cluster surface.

12.
J Synchrotron Radiat ; 28(Pt 3): 995-1005, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33950008

RESUMEN

We report on a custom-built UHV-compatible Magneto-Optical Kerr Effect (MOKE) magnetometer for applications in surface and materials sciences, operating in tandem with the PhotoEmission Electron Microscope (PEEM) endstation at the Nanospectroscopy beamline of the Elettra synchrotron. The magnetometer features a liquid-nitrogen-cooled electromagnet that is fully compatible with UHV operation and produces magnetic fields up to about 140 mT at the sample. Longitudinal and polar MOKE measurement geometries are realized. The magneto-optical detection is based on polarization analysis using a photoelastic modulator. The sample manipulation system is fully compatible with that of the PEEM, making it possible to exchange samples with the beamline endstation, where complementary X-ray imaging and spectroscopy techniques are available. The magnetometer performance is illustrated by experiments on cobalt ultra-thin films, demonstrating close to monolayer sensitivity. The advantages of combining in situ growth, X-ray Magnetic Circular Dichroism imaging (XMCD-PEEM) and MOKE magnetometry into a versatile multitechnique facility are highlighted.

13.
Chem Phys Lipids ; 237: 105081, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33811848

RESUMEN

The aim of this research was to study the effect of marketed tablet (Crestor®) powder suspension (MTPS) and nanoparticle formulation of rosuvastatin calcium (RC) on the pharmacokinetic (PK) and pharmacodynamic (PD) parameters in hyperlipidemia rats. The hyperlipidemia is induced by intraperitoneal injection of Triton-X-100 in 0.9 %w/v saline solution. The marketed tablet was dispersed into suspension. The RC loaded nanoparticles (RC-NPs) are prepared by homogenization method. The prepared RC-NP formulation was characterized for size, drug excipient compatibility and crystallization by differential scanning calorimeter (DSC), morphology by SEM, stability at room temperature, in-vitro dissolution and in-situ absorption in rats. Further, the pharmacokinetic and pharmacodynamic studies were conducted in hyperlipidemia rats. The size of the RC-NP formulation was found to be 183.4 ± 4.5 nm and to be nearly spherical by SEM. DSC studies revealed that no interaction and RC converted to amorphous form in RC-NP formulation. RC-NP formulation was physically and chemically stable over two months at room temperature. The drug release was found to be 25.8 ± 2.5 and 89.96 ± 2.8 % in five mins, respectively from MTPS and RC-NP formulations. The Peff of MTPS and NP of RC was 1.8 ± 0.2 × 10-5 and 2.7 ± 0.3 × 10-5 cm/s, respectively. From the PK studies, the enhancement in the oral bioavailability was found to be 2.4-folds when compared to MTPS formulation and statistically significant (p < 0.05). PD study of RC-NP formulation in hyperlipidemic rats exhibited decrease in lipid profile for 24 h, while MTPS exhibited a decrease in lipid profile for 12 h. Therefore, the results conclusively demonstrate the nanoparticles of RC showed significant enhancement in the PK and PD parameters.


Asunto(s)
Lípidos/análisis , Nanopartículas/química , Rosuvastatina Cálcica/metabolismo , Administración Oral , Animales , Disponibilidad Biológica , Portadores de Fármacos/química , Composición de Medicamentos , Liberación de Fármacos , Estabilidad de Medicamentos , Semivida , Hiperlipidemias/inducido químicamente , Hiperlipidemias/tratamiento farmacológico , Hiperlipidemias/patología , Masculino , Octoxinol/toxicidad , Tamaño de la Partícula , Ratas , Ratas Wistar , Rosuvastatina Cálcica/química , Rosuvastatina Cálcica/farmacocinética , Rosuvastatina Cálcica/uso terapéutico
14.
Angew Chem Int Ed Engl ; 59(52): 23554-23558, 2020 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-32918778

RESUMEN

The adsorption and electrooxidation of CO molecules at well-defined Pt(hkl) single-crystal electrode surfaces is a key step towards addressing catalyst poisoning mechanisms in fuel cells. Herein, we employed in situ electrochemical shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) coupled with theoretical calculation to investigate CO electrooxidation on Pt(hkl) surfaces in acidic solution. We obtained the Raman signal of top- and bridge-site adsorbed CO* molecules on Pt(111) and Pt(100). In contrast, on Pt(110) surfaces only top-site adsorbed CO* was detected during the entire electrooxidation process. Direct spectroscopic evidence for OH* and COOH* species forming on Pt(100) and Pt(111) surfaces was afforded and confirmed subsequently via isotope substitution experiments and DFT calculations. In summary, the formation and adsorption of OH* and COOH* species plays a vital role in expediting the electrooxidation process, which relates with the pre-oxidation peak of CO electrooxidation. This work deepens knowledge of the CO electrooxidation process and provides new perspectives for the design of anti-poisoning and highly effective catalysts.

15.
J Synchrotron Radiat ; 27(Pt 5): 1209-1217, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32876595

RESUMEN

Understanding the crystallization process for chemical solution deposition (CSD) processed thin films is key in designing the fabrication strategy for obtaining high-quality devices. Here, an in situ sample environment is presented for studying the crystallization of CSD processed thin films under typical processing parameters using near-grazing-incidence synchrotron X-ray diffraction. Typically, the pyrolysis is performed in a rapid thermal processing (RTP) unit, where high heating rates, high temperatures and atmosphere control are the main control parameters. The presented in situ setup can reach heating rates of 20°C s-1 and sample surface temperatures of 1000°C, comparable with commercial RTP units. Three examples for lead-free ferroelectric thin films are presented to show the potential of the new experimental set-up: high temperature, for crystallization of highly textured Sr0.4Ba0.6Nb2O6 on a SrTiO3 (001) substrate, high heating rate, revealing polycrystalline BaTiO3, and atmosphere control with 25% CO2, for crystallization of BaTiO3. The signal is sufficient to study a single deposited layer (≥10 nm for the crystallized film) which then defines the interface between the substrate and thin film for the following layers. A protocol for processing the data is developed to account for a thermal shift of the entire setup, including the sample, to allow extraction of maximum information from the refinement, e.g. texture. The simplicity of the sample environment allows for the future development of even more advanced measurements during thin-film processing under non-ambient conditions.

16.
ACS Nano ; 14(8): 9861-9872, 2020 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-32701267

RESUMEN

Attachment of trophozoites to the intestine is an indispensable step for Giardia's survival and pathogenicity in almost 280 million infections worldwide each year. However, the analysis of the attachment mechanism is difficult due to the lack of methods that can create a favorable microaerobic atmosphere. Herein, we developed an osmotic-pressure, pH, excretion, nutrition, gas, ionic-strength, flow-rate, and temperature microenvironment-controlled micropatterned microfluidic model to simulate the in vivo microenvironment to study in situ the stress applied to Giardia in the intestinal tract. We designed three nonbiological surfaces with stagger arrangement manners and integrated them with a resistance microfluidic network to split Giardia-attaching forces ingeniously and developed the term "attaching contribution rate" (ACR) to describe their corresponding contributions. Our study shows that the total attaching force measured is 49.58 Pa, with three components being 22.66 Pa (suction force), 12.52 Pa (clutching force), and 14.4 Pa (combined electrostatic and van der Waals force), respectively, with ACRs being 46%, 25%, and 29%, respectively. By decomposing the attaching force and analyzing each force component and their structure and composition basis, whole profiles of the attachment mechanisms were revealed. Our method enables the analysis of the surface attachment mechanisms and their ACRs for Giardia.


Asunto(s)
Biomimética , Microfluídica , Giardia , Intestinos , Temperatura
17.
Angew Chem Int Ed Engl ; 59(32): 13458-13462, 2020 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-32187814

RESUMEN

Recent progress in the field of mechanochemistry has expanded the discovery of mechanically induced chemical transformations to several areas of science. However, a general fundamental understanding of how mechanochemical reactions by ball milling occur has remained unreached. For this, we have now implemented in situ monitoring of a mechanochemically induced molecular rearrangement by synchrotron X-ray powder diffraction, Raman spectroscopy, and real-time temperature sensing. The results of this study demonstrate that molecular rearrangements can be accomplished in the solid state by ball milling and how in situ monitoring techniques enable the visualization of changes occurring at the exact instant of a molecular migration. The mechanochemical benzil-benzilic acid rearrangement is the focal point of the study.

18.
Angew Chem Int Ed Engl ; 58(33): 11527-11533, 2019 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-31206996

RESUMEN

Efficient electro-oxidation of formic acid, methanol, and ethanol is challenging owing to the multiple chemical reaction steps required to accomplish full oxidation to CO2 . Herein, a ternary CoPtAu nanoparticle catalyst system is reported in which Co and Pt form an intermetallic L10 -structure and Au segregates on the surface to alloy with Pt. The L10 -structure stabilizes Co and significantly enhances the catalysis of the PtAu surface towards electro-oxidation of ethanol, methanol, and formic acid, with mass activities of 1.55 A/mgPt , 1.49 A/mgPt , and 11.97 A/mgPt , respectively in 0.1 m HClO4 . The L10 -CoPtAu catalyst is also stable, with negligible degradation in mass activities and no obvious Co/Pt/Au composition changes after 10 000 potential cycles. The in situ surface-enhanced infrared absorption spectroscopy study indicates that the ternary catalyst activates the C-C bond more efficiently for ethanol oxidation.

19.
Int J Mol Sci ; 20(9)2019 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-31067781

RESUMEN

Despite the constantly updated knowledge regarding the alterations occurring in the cells of patients with psoriasis, the status and the role of the lysosome, a control center of cell metabolism, remain to be elucidated. The architecture of the epidermis is largely regulated by the action of lysosomes, possibly activating signaling pathways in the cellular crosstalk of keratinocytes-epidermal cells-with infiltrating immune cells. Thus, in the present study, lysosome alterations were examined in vitro and in situ using a two-dimensional (2D) keratinocyte model of HaCaT cells with "psoriasis-like" inflammation and skin specimens, respectively. Specific fluorescence and immunohistochemical staining showed an augmented level of acidic organelles in response to keratinocyte activation (mimicking a psoriatic condition while maintaining the membrane integrity of these structures) as compared with the control, similar to that seen in skin samples taken from patients. Interestingly, patients with the most pronounced PASI (Psoriasis Area and Severity Index), BSA (Body Surface Area), and DLQI (Dermatology Life Quality Index) scores suffered a high incidence of positive lysosomal-associated membrane protein 1 (LAMP1) expression. Moreover, it was found that the gene deregulation pattern was comparable in lesioned (PP) and non-lesioned (PN) patient-derived skin tissue, which may indicate that these alterations occur prior to the onset of the characteristic phenotype of the disease. Changes in the activity of genes encoding the microphthalmia family (MiT family) of transcription factors and mammalian target of rapamycin complex 1 (MTORC1) were also observed in the in vitro psoriasis model, indicating that the biogenesis pathway of this arm is inhibited. Interestingly, in contrast to the keratinocytes of HaCaT with "psoriasis-like" inflammation, LAMP1 was up-regulated in both PP and PN skin, which can be a potential sign of an alternative mechanism of lysosome formation. Defining the molecular profile of psoriasis in the context of "the awesome lysosome" is not only interesting, but also desired; therefore, it is believed that this paper will serve to encourage other researchers to conduct further studies on this subject.


Asunto(s)
Queratinocitos/metabolismo , Lisosomas/metabolismo , Psoriasis/metabolismo , Piel/metabolismo , Adulto , Anciano , Línea Celular , Femenino , Humanos , Queratinocitos/ultraestructura , Proteínas de Membrana de los Lisosomas/genética , Proteínas de Membrana de los Lisosomas/metabolismo , Lisosomas/ultraestructura , Masculino , Diana Mecanicista del Complejo 1 de la Rapamicina/genética , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Persona de Mediana Edad , Psoriasis/patología , Piel/ultraestructura
20.
Acta Crystallogr A Found Adv ; 75(Pt 2): 214-222, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30821256

RESUMEN

The increasing efficiency of detectors and brightness of X-rays in both laboratory and large-scale facilities allow the collection of full single-crystal X-ray data sets within minutes. The analysis of these `crystallographic big data' requires new tools and approaches. To answer these needs, the use of principal component analysis (PCA) is proposed to improve the efficiency and speed of the analysis. Potentialities and limitations of PCA were investigated using single-crystal X-ray diffraction (XRD) data collected in situ on Y zeolite, in which CO2, acting as an active species, is thermally adsorbed while cooling from 300 to 200 K. For the first time, thanks to the high sensitivity of single-crystal XRD, it was possible to determine the sites where CO2 is adsorbed, the increase in their occupancy while the temperature is decreased, and the correlated motion of active species, i.e. CO2, H2O and Na+. PCA allowed identification and elimination of problematic data sets, and better understanding of the trends of the occupancies of CO2, Na+ and water. The quality of the data allowed for the first time calculation of the enthalpy (ΔH) and entropy (ΔS) of the CO2 adsorption by applying the van 't Hoff equation to in situ single-crystal data. The calculation of thermodynamic values was carried out by both traditional and PCA-based approaches, producing comparable results. The obtained ΔH value is significant and involves systems (CO2 and Y zeolite) with no toxicity, superb stability and chemical inertness. Such features, coupled with the absence of carbonate formation and framework inertness upon adsorption, were demonstrated for the bulk crystal by the single-crystal experiment, and suggest that the phenomenon can be easily reversed for a large number of cycles, with CO2 released on demand. The main advantages of PCA-assisted analysis reside in its speed and in the possibility of it being applied directly to raw data, possibly as an `online' data-quality test during data collection, without any a priori knowledge of the crystal structure.

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