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Molecular chaperones are key components of the cellular proteostasis network whose role includes the suppression of the formation and proliferation of pathogenic aggregates associated with neurodegenerative diseases. The molecular principles that allow chaperones to recognize misfolded and aggregated proteins remain, however, incompletely understood. To address this challenge, here we probe the thermodynamics and kinetics of the interactions between chaperones and protein aggregates under native solution conditions using a microfluidic platform. We focus on the binding between amyloid fibrils of α-synuclein, associated with Parkinson's disease, to the small heat-shock protein αB-crystallin, a chaperone widely involved in the cellular stress response. We find that αB-crystallin binds to α-synuclein fibrils with high nanomolar affinity and that the binding is driven by entropy rather than enthalpy. Measurements of the change in heat capacity indicate significant entropic gain originates from the disassembly of the oligomeric chaperones that function as an entropic buffer system. These results shed light on the functional roles of chaperone oligomerization and show that chaperones are stored as inactive complexes which are capable of releasing active subunits to target aberrant misfolded species.
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Amiloide/metabolismo , Proteínas de Choque Térmico Pequeñas/metabolismo , Cadena B de alfa-Cristalina/metabolismo , alfa-Sinucleína/metabolismo , Entropía , Humanos , Enfermedad de Parkinson/metabolismo , Agregado de Proteínas/fisiología , Proteostasis/fisiologíaRESUMEN
OBJECTIVES: Adult-onset Still's disease (AOSD) is increasingly viewed as autoinflammatory disease associated with the so-called inflammasomopathy. Proinflammatory cytokines, such as IL-18 and IL-1ß, processed through the inflammasome machinery, play an important role in the pathogenesis of AOSD. AOSD is heterogenous, therefore there are two subtypes of the disease, systemic and articular, which probably imply different approaches for the treatment. Over 20% of patients with systemic AOSD have serositis. Recently, colchicine in combination with non-steroidal anti-inflammatory drugs (NSAIDs) has become the "gold standard" for recurrent pericarditis treatment. However, data on this combination therapy in AOSD are scarce. METHODS: In this retrospective case series study, we assessed the medical history of 20 patients with a systemic form of AOSD. All patients had pericarditis and received а combination of NSAIDs (in most cases ibuprofen 600-800 mg x3 daily) and colchicine (1 mg daily) for treatment. RESULTS: 13/20 (65%) of patients responded to this combination of anti-inflammatory drugs. Of note, not only pericarditis, but also other manifestations were improved such as arthritis, rash, hepatomegaly, acute phase reactants, and abnormal liver tests. CONCLUSIONS: The low cost, safety and wide availability of such therapy make this option relevant and determine the need for further study.
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Pericarditis , Serositis , Enfermedad de Still del Adulto , Adulto , Antiinflamatorios/uso terapéutico , Antiinflamatorios no Esteroideos/uso terapéutico , Colchicina/efectos adversos , Humanos , Pericarditis/complicaciones , Pericarditis/tratamiento farmacológico , Estudios Retrospectivos , Enfermedad de Still del Adulto/complicaciones , Enfermedad de Still del Adulto/diagnóstico , Enfermedad de Still del Adulto/tratamiento farmacológicoRESUMEN
A new reality of the 21st century is the transition to a new type of economy and energy concepts characterized by the replacement of existing petrochemical routes to a bio-based circular economy. The needs for new strategies in obtaining basic products from bio-based resources with minimum CO2 traces has become mandatory. In this review, recent trends in the conversion of biomass-derived molecules, such as simple monomeric sugars and cellulose, to industrially important C5 and C6 sugar alcohols on heterogeneous catalysts based on non-noble metals are discussed focusing on the influence of catalyst structures and reaction conditions used on the substrate conversion and product selectivity. The challenges and prominent ideas are suggested for the further development of catalytic hydrogenation of naturally abundant carbohydrates to value-added chemicals on non-noble metal catalysts.
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In this work, we studied the role of zinc in the composition of supported iron-containing catalysts for the hydrogenation of CO2. Various variants of incipient wetness impregnation of the support were tested to obtain catalyst samples. The best results are shown for samples synthesized by co-impregnation of the support with a common solution of iron and zinc precursors at the same molar ratio of iron and zinc. Catalyst samples were analyzed by various methods: Raman, DRIFT-CO, TPR-H2, XPS, and UV/Vis. The introduction of zinc leads to the formation of a mixed ZnFe2O4 phase. In this case, the activation of the catalyst proceeds through the stage of formation of the metastable wustite phase FeO. The formation of this wustite phase promotes the formation of metallic iron in the composition of the catalyst under the reaction conditions. It is believed that the presence of metallic iron is a necessary step in the formation of iron carbides-that is, active centers for the formation and growth of chain in the hydrocarbons. This leads to an increase in the activity and selectivity of the formation of hydrocarbons in the process of CO2 hydrogenation.
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The conventional staging classification reduces all patterns of sleep polysomnogram signals to a small number of yes-or-no variables labeled wake or a stage of sleep (e.g., W, N1, N2, N3, and R for wake, the first, second, and third stages of non-rapid eye movement sleep and rapid eye movement sleep, respectively). However, the neurobiological underpinnings of such stages remained to be elucidated. We tried to evaluate their link to scores on the first and second principal components of the EEG spectrum (1PCS and 2PCS), the markers of two major groups of promoters/inhibitors of sleep/wakefulness delineated as the drives for sleep and wake, respectively. On two occasions, polysomnographic records were obtained from 69 university students during 50-min afternoon naps and 30-s stage epochs were assigned to 1PCS and 2PCS. Results suggested two dimensionality of the structure of individual differences in amounts of stages. Amount of N1 loaded exclusively on one of two dimensions associated with 1PCS, amounts of W and N2 loaded exclusively on another dimension associated with 2PCS, and amount of N3 was equally loaded on both dimensions. Scores demonstrated stability within each stage, but a drastic change in just one of two scores occurred during transitions from one stage to another on the way from wakefulness to deeper sleep (e.g., 2PCS changed from >0 to <0 during transition WâN1, 1PCS changed from <0 to >0 during transition N1âN2). Therefore, the transitions between stages observed during short naps might be linked to rapid changes in the reciprocal interactions between the promoters/inhibitors of sleep/wakefulness.NEW & NOTEWORTHY In the present nap study, two dimensionality of the structure of individual differences in sleep stages was revealed. These results also suggested that individual variation in the sleep and wake drives associated with the first and second principal components of the EEG spectrum might underlie this structure. It seemed that each stage might be related to a certain, stage-specific combination of wake-sleep promoting/inhibiting influences associated with these drives for sleep and wake.
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Corteza Cerebral/fisiología , Electroencefalografía/métodos , Fases del Sueño/fisiología , Vigilia/fisiología , Adolescente , Adulto , Variación Biológica Poblacional , Análisis Factorial , Femenino , Humanos , Masculino , Polisomnografía , Análisis de Componente Principal , Adulto JovenRESUMEN
PURPOSE: Since disagreement has been found between an objective sleep propensity measured by sleep onset latency (SOL) and subjective sleepiness assessment measured by the Epworth sleepiness scale (ESS) score, distinct underlying causes and consequences were suggested for these two sleepiness measures. We addressed the issue of validation of the ESS against objective sleepiness and sleep indexes by examining the hypothesis that these two sleepiness measures are disconnected due to their differential relationship with the antagonistic drives for sleep and wake. METHODS: The polysomnographic records of 50-min napping attempts were collected from 27 university students on three occasions. Scores on the first and second principal components of the electroencephalographic (EEG) spectrum were calculated to measure the sleep and wake drives, respectively. Self-assessments of subjective sleepiness and sleep were additionally collected in online survey of 633 students at the same university. RESULTS: An ESS score was disconnected with the polysomnographic and self-assessed SOL in the nap study and online survey, respectively. An ESS score but not SOL was significantly linked to the spectral EEG measure of the sleep drive, while SOL but not ESS showed a significant association with the spectral EEG measure of the opposing wake drive. CONCLUSIONS: Each of two sleepiness measures was validated against objective indicators of the opposing sleep-wake regulating processes, but different underlying causes were identified for two distinct aspects of sleepiness. A stronger sleep drive and a weaker opposing drive for wake seem to contribute to a higher ESS score and to a shorter SOL, respectively.
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Corteza Cerebral/fisiología , Somnolencia/fisiología , Vigilia/fisiología , Adulto , Electroencefalografía , Femenino , Humanos , Masculino , Polisomnografía , Adulto JovenRESUMEN
The paper presents the results obtained in studying glycerol hydrogenolysis into 1-propanol and 2-propanol over bifunctional Ni/WO3-TiO2 and Ni/WO3-ZrO2 catalysts in the flow system. Due to the optimal combination of acidic and hydrogenation properties of the heterogeneous catalysts, they exhibit higher performance in glycerol conversion into C3 alcohols, although the process is carried out in rather mild conditions. At the reaction temperature of 250 °C and hydrogen pressure of 3 MPa, the total yield of 1-propanol and 2-propanol reaches 95%, and the glycerol conversion is close to 100%.
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The nonoxidative conversion of ethanol to acetaldehyde under thermal and microwave heating was studied on mixed oxide ZnO-CuO-SiO2 catalysts modified with additives of tungsten carbide nanoparticles. The results revealed that the WC-modified catalyst exhibited superior activity and selectivity under microwave heating conditions. It is assumed that when microwave heating is used, hot zones can appear at the contact points of WC nanoparticles and active centers of the mixed oxide ZnO-CuO-SiO2 catalyst, which intensively absorb microwave energy, allowing the more efficient formation of acetaldehyde at moderate temperatures. Thermodynamic calculations of equilibrium concentrations of reagents and products allowed us to identify the optimal conditions for effective acetaldehyde production. The initial catalyst and the catalyst prepared by the coprecipitation of the oxides with the addition of WC were characterized by physicochemical methods (TPR-H2, XRD, DRIFTS of adsorbed CO). The active centers of the oxide catalyst can be Cu+ cations.
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Relapsing Evans syndrome (ES) and systemic lupus erythematosus (SLE) with secondary antiphospholipid syndrome (APS) is very rare association. Coexistence of these syndromes is potentially fatal and require high-dose combined immunosuppressive therapy. We describe a case of successful use of Bortezomib and plasma exchange in a patient with ES and APS refractory to standard therapy. Thirty-two-year-old male who presented episodes of relapsing hemolytic anemia, pancytopenia and multiple thrombosis with positive direct and indirect antiglobulin test result, lupus anticoagulant and medium titer of anti-beta-2-glycoprotein 1 and anti-cardiolipin antibodies was diagnosed with ES and SLE with secondary APS. High-dose therapy by steroids and Cyclosporin A were started with temporary improvement. There was also no stable improvement with Rituximab and Cyclophosphamide. Bortezomib in combination with cyclosporine A and plasma exchange was introduced. He had stable improvement in hematological parameters with no evidence of relapse of hemolytic crisis or thrombosis during a follow-up for 1â¯year.
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Anemia Hemolítica Autoinmune/terapia , Síndrome Antifosfolípido/terapia , Bortezomib/uso terapéutico , Lupus Eritematoso Sistémico/terapia , Intercambio Plasmático , Trombocitopenia/terapia , Adulto , Anemia Hemolítica Autoinmune/inmunología , Síndrome Antifosfolípido/inmunología , Humanos , Lupus Eritematoso Sistémico/inmunología , Masculino , Recurrencia , Trombocitopenia/inmunología , beta 2 Glicoproteína I/inmunologíaRESUMEN
Type I modular polyketide synthases (PKSs) produce polyketide natural products by passing a growing acyl substrate chain between a series of enzyme domains housed within a gigantic multifunctional polypeptide assembly. Throughout each round of chain extension and modification reactions, the substrate stays covalently linked to an acyl carrier protein (ACP) domain. In the present study we report on the solution structure and dynamics of an ACP domain excised from MLSA2, module 9 of the PKS system that constructs the macrolactone ring of the toxin mycolactone, cause of the tropical disease Buruli ulcer. After modification of apo ACP with 4'-phosphopantetheine (Ppant) to create the holo form, (15)N nuclear spin relaxation and paramagnetic relaxation enhancement (PRE) experiments suggest that the prosthetic group swings freely. The minimal chemical shift perturbations displayed by Ppant-attached C3 and C4 acyl chains imply that these substrate-mimics remain exposed to solvent at the end of a flexible Ppant arm. By contrast, hexanoyl and octanoyl chains yield much larger chemical shift perturbations, indicating that they interact with the surface of the domain. The solution structure of octanoyl-ACP shows the Ppant arm bending to allow the acyl chain to nestle into a nonpolar pocket, whereas the prosthetic group itself remains largely solvent exposed. Although the highly reduced octanoyl group is not a natural substrate for the ACP from MLSA2, similar presentation modes would permit partner enzyme domains to recognize an acyl group while it is bound to the surface of its carrier protein, allowing simultaneous interactions with both the substrate and the ACP.
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Proteína Transportadora de Acilo/química , Macrólidos/química , Mycobacterium ulcerans , Sintasas Poliquetidas/química , Proteína Transportadora de Acilo/metabolismo , Macrólidos/metabolismo , Sintasas Poliquetidas/metabolismo , Estructura Secundaria de Proteína , Estructura Terciaria de ProteínaRESUMEN
African trypanosomes are protected by a densely packed surface monolayer of variant surface glycoprotein (VSG). A haptoglobin-hemoglobin receptor (HpHbR) within this VSG coat mediates heme acquisition. HpHbR is also exploited by the human host to mediate endocytosis of trypanolytic factor (TLF)1 from serum, contributing to innate immunity. Here, the crystal structure of HpHbR from Trypanosoma congolense has been solved, revealing an elongated three α-helical bundle with a small membrane distal head. To understand the receptor in the context of the VSG layer, the dimensions of Trypanosoma brucei HpHbR and VSG have been determined by small-angle X-ray scattering, revealing the receptor to be more elongated than VSG. It is, therefore, likely that the receptor protrudes above the VSG layer and unlikely that the VSG coat can prevent immunoglobulin binding to the receptor. The HpHb-binding site has been mapped by single-residue mutagenesis and surface plasmon resonance. This site is located where it is readily accessible above the VSG layer. A single HbHpR polymorphism unique to human infective T. brucei gambiense has been shown to be sufficient to reduce binding of both HpHb and TLF1, modulating ligand affinity in a delicate balancing act that allows nutrient acquisition but avoids TLF1 uptake.
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Endocitosis/inmunología , Inmunidad Innata/inmunología , Receptores de Superficie Celular/inmunología , Glicoproteínas Variantes de Superficie de Trypanosoma/inmunología , Secuencia de Aminoácidos , Animales , Sitios de Unión/genética , Interacciones Huésped-Parásitos/inmunología , Humanos , Modelos Moleculares , Datos de Secuencia Molecular , Mutación , Unión Proteica , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Receptores de Superficie Celular/química , Receptores de Superficie Celular/genética , Dispersión del Ángulo Pequeño , Homología de Secuencia de Aminoácido , Resonancia por Plasmón de Superficie , Trypanosoma brucei brucei/genética , Trypanosoma brucei brucei/inmunología , Trypanosoma brucei brucei/fisiología , Trypanosoma brucei gambiense/genética , Trypanosoma brucei gambiense/inmunología , Trypanosoma brucei gambiense/fisiología , Trypanosoma congolense/genética , Trypanosoma congolense/inmunología , Trypanosoma congolense/fisiología , Tripanosomiasis Africana/inmunología , Tripanosomiasis Africana/parasitología , Glicoproteínas Variantes de Superficie de Trypanosoma/química , Glicoproteínas Variantes de Superficie de Trypanosoma/genética , Difracción de Rayos XRESUMEN
Sleep deprivation (SD) can degrade cognitive functioning, but growing evidence suggests that there are large individual differences in the vulnerability to this effect. Some evidence suggests that baseline differences in the responsiveness of a fronto-parietal attention system that is activated during working memory (WM) tasks may be associated with the ability to sustain vigilance during sleep deprivation. However, the neurocircuitry underlying this network remains virtually unexplored. In this study, we employed diffusion tensor imaging (DTI) to investigate the association between the microstructure of the axonal pathway connecting the frontal and parietal regions--i.e., the superior longitudinal fasciculus (SLF)--and individual resistance to SD. Thirty healthy participants (15 males) aged 20-43 years underwent functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) at rested wakefulness prior to a 28-hour period of SD. Task-related fronto-parietal fMRI activation clusters during a Sternberg WM Task were localized and used as seed regions for probabilistic fiber tractography. DTI metrics, including fractional anisotropy, mean diffusivity, axial and radial diffusivity were measured in the SLF. The psychomotor vigilance test (PVT) was used to evaluate resistance to SD. We found that activation in the left inferior parietal lobule (IPL) and dorsolateral prefrontal cortex (DLPFC) positively correlated with resistance. Higher fractional anisotropy of the left SLF comprising the primary axons connecting IPL and DLPFC was also associated with better resistance. These findings suggest that individual differences in resistance to SD are associated with the functional responsiveness of a fronto-parietal attention system and the microstructural properties of the axonal interconnections.
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Nivel de Alerta , Trastornos del Conocimiento/patología , Lóbulo Frontal/patología , Lóbulo Parietal/patología , Privación de Sueño/patología , Sustancia Blanca/patología , Adulto , Trastornos del Conocimiento/fisiopatología , Conectoma/métodos , Imagen de Difusión Tensora/métodos , Resistencia a la Enfermedad/fisiología , Femenino , Lóbulo Frontal/fisiopatología , Humanos , Masculino , Memoria a Corto Plazo , Vías Nerviosas/patología , Vías Nerviosas/fisiopatología , Lóbulo Parietal/fisiopatología , Privación de Sueño/fisiopatología , Sustancia Blanca/fisiopatología , Adulto JovenRESUMEN
Sleep problems often co-occur with psychopathological conditions and affective dysregulation. Individuals with mood disorders have significantly higher rates of sleep disturbances than healthy individuals, and among those with mood disorders, sleep problems are associated with lower rates of remission and response to treatment. Sleep disruption may itself be a risk factor for various forms of psychopathology, as experimental sleep deprivation has been found to lead to increased affective, cognitive, and somatic symptoms within healthy volunteers. However, little is known about the relationship between recurring sleep complaints in a naturalistic environment and symptoms of psychopathology among healthy individuals. In the present study, 49 healthy adults (21 males and 28 females) reported sleep quality and completed the Personality Assessment Inventory, a standardized self-report assessment of symptoms of psychopathology. Consistent with prior published findings during total sleep deprivation, individuals endorsing self-reported naturally occurring sleep problems showed higher scores on scales measuring somatic complaints, anxiety, and depression. Furthermore, the reported frequency of sleep disturbance was closely linked with the severity of self-reported symptoms. While causal directionality cannot be inferred, these findings support the notion that sleep and emotional functioning are closely linked.
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Trastorno de Personalidad Antisocial/complicaciones , Trastornos del Sueño-Vigilia/etiología , Adolescente , Adulto , Análisis de Varianza , Femenino , Humanos , Masculino , Persona de Mediana Edad , Inventario de Personalidad , Escalas de Valoración Psiquiátrica , Estadísticas no Paramétricas , Adulto JovenRESUMEN
Establishing well-defined relationships between sleep features and memory consolidation is essential in comprehending the pathophysiology of cognitive decline commonly seen in patients with insomnia, depression, and other sleep-disrupting conditions. Twenty-eight volunteers participated in two experimental sessions: a session with selective SWS suppression during one night and a session with undisturbed night sleep (as a control condition). Fifteen of them also participated in a third session with REM suppression. Suppression was achieved by presenting an acoustic tone. In the evening and the morning, the participants completed procedural and declarative memory tasks and the Psychomotor vigilance task (PVT). Heart rate variability analysis and salivary cortisol were used to control possible stress reactions to sleep interference. SWS and REM suppression led to more than 50 percent reduction in the amount of these stages. Neither vigilance nor memory consolidation was impaired after SWS or REM suppression. Unexpectedly, a beneficial effect of selective SWS suppression on PVT performance was found. Similarly, after a night with SWS suppression, the overnight improvement in procedural skills was higher than after a night with REM suppression and after a night with undisturbed sleep. Our data brings into question the extent to which SWS and REM are truly necessary for effective memory consolidation to proceed. Moreover, SWS suppression may even improve the performance of some tasks, possibly by reducing sleep inertia associated with undisturbed sleep.
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Catalysts with no hazardous or toxic components are required for the selective hydrogenation of acetylenic bonds in the synthesis of pharmaceuticals, vitamins, nutraceuticals, and fragrances. The present work demonstrates that a high selectivity to alkene can be reached over a Pd-Fe-O/SiO2 system prepared by the co-impregnation of a silica support with a solution of the metal precursors (NH4)3[Fe(C2O4)3] and [Pd(NH3)4]Cl2 followed by thermal treatment in hydrogen or in air at 400 °C. A DRIFT spectroscopic study of CO adsorption revealed large shifts in the position of the Pdn+-CO bands for this system, indicating the strong effect of Fen+ on the Pd electronic state, resulting in a decreased rate of double C=C bond hydrogenation and an increased selectivity of alkyne hydrogenation to alkene. The prepared catalysts consisted of mono- and bimetallic nanoparticles on an SiO2 carrier and exhibited a selectivity as high as that of the commonly used Lindlar catalyst (which contains such hazardous components as lead and barium), while the activity of the Fe-Pd-O/SiO2 catalyst was an order of magnitude higher. The hydrogenation of a triple bond over the proposed Pd-Fe catalyst opens the way to selective hydrogenation over nontoxic catalysts with a high yield and productivity. Taking into account a simple procedure of catalyst preparation, this direction provides a rationale for the large-scale implementation of these catalysts.
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Because of the growing demand for high-quality fuels, the light cycle oil fraction improvement including cetane number improvement is important. The main way to reach this improvement is the ring opening of cyclic hydrocarbons, and a highly effective catalyst should be found. Cyclohexane ring openings are a possible option to investigate the catalyst activity. In this work, we investigated rhodium-loaded catalysts prepared using the commercially available industrial supports: single-component ones, SiO2 and Al2O3; and mixed oxides CaO + MgO + Al2O3 and Na2O + SiO2 + Al2O3. The catalysts were prepared by incipient wetness impregnation and investigated by N2 low-temperature adsorption-desorption, XRD, XPS, DRS UV-Vis and DRIFT spectroscopy, SEM, and TEM with EDX. The catalytic tests were performed in cyclohexane ring opening in the range of 275-325 °C. The best result was demonstrated by the sample 1Rh/CaMgAlO: the selectivity to n-hexane was about 75% while the cyclohexane conversion was about 25% at 275 °C. The space-time yield was up to 12 mmoln-hexane gcat-1h-1.
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Active and stable catalysts are essential for effective hydrogenation of gaseous CO2 into valuable chemicals. This work focuses on the structural and catalytic features of single metals, i.e., Co and Ni, as well as bimetallic CoNi alloy catalysts synthesized via combustion of reactive sol-gels. Different characterization methods were used for studying the relationships between the structure, composition, and catalytic activity of the fabricated materials. All catalysts exhibited highly porous sponge-like microstructure. The outermost surfaces of the CoNi alloys were more saturated with Co, while a stoichiometric Co/Ni ratio was observed for the particle's bulk. Catalytic properties of the as-synthesized powders were studied in the CO2 hydrogenation reaction at 300 °C for over 80 h of time on stream. All the catalysts demonstrated exceptional selectivity with respect to CH4 formation. However, the combination of elemental Co and Ni in a single phase resulted in a synergistic effect in bulk alloy catalysts, with activity twofold to threefold that of single-metal catalysts. The activity and stability of the CoNi3 catalyst were higher than those previously reported for Ni-based catalysts. The reasons for this behavior are discussed.
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Composite materials have been used based on coordination polymers or microporous metal-organic frameworks (MOFs) combined with mesoporous matrices for adsorption-related techniques, which enable outflanking some adverse phenomena manifested during pristine components operation and enhance the performance and selectivity of the resulting materials. In this work, for the first time, the novel HKUST-1@BPS composites synthesized by the microwave-assisted (MW) technique starting from microporous HKUST-1 (Cu3(btc)2) MOF and biporous silica matrix (BPS) with bimodal mesopore size distribution were comparatively studied as materials for liquid-phase adsorption techniques utilizing the high-performance liquid chromatography (HPLC) method and benzene as a model adsorbate. It was established that the studied HKUST-1@BPS composites can function as stationary phases for HPLC, unlike the pristine HKUST-1 and bare BPS materials, due to the synergetic effect of both components based on the preliminary enhanced adsorbate mass transfer throughout the silica mesopores and, subsequently, its penetrating into HKUST-1 micropores. The suggested mechanism involves the initial deactivation of open metal Cu2+ sites in the HKUST-1 framework structure by isopropanol molecules upon adding this polar component into the mobile phase in the region of the isopropanol concentration of 0.0 to 0.2 vol.%. Thereafter, at the medium range of varying the isopropanol concentration in the eluent of 0.2 to 0.3 vol.%, there is an expansion of the previously inaccessible adsorption centers in the HKUST-1@BPS composites. Subsequently, while further increasing the isopropanol volume fraction in the eluent in the region of 0.3 to 5.0 vol.%, the observed behavior of the studied chromatographic systems is similar to the quasi-normal-phase HPLC pattern. According to the obtained thermodynamic data, benzene adsorption into HKUST-1 micropores from solutions with a vol.% of isopropanol in the range of 0.4 to 5.0 follows the unique entropy-driven mechanism previously described for the MIL-53(Al) framework. It was found that HKUST-1 loading in the composites and their preparation conditions have pronounced effects on their physicochemical properties and adsorption performance, including the adsorption mechanism.
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The hydroamination of alkynes is an atom-economy process in the organic synthesis for the C-N bond formation, thereby allowing the production of fine chemicals and intermediates. However, direct interaction between alkynes and amines is complicated due to the electron enrichment of both compounds. Therefore, efficient hydroamination catalysts, especially heterogeneous ones, are in great demand. This work aimed at the development of novel heterogeneous catalysts based on zeolite-like metal-organic frameworks for phenylacetylene hydroamination. The sodalite (SOD) type zeolitic imidazolate framework ZIF-67 (Co(meim)2, meim = 2-methylimidazolate) and boron imidazolate framework BIF-66 ({Co[B(im)4]2}n, im = imidazolate) were studied as the carriers for the gold nanoparticles (Au-NPs). Au-NPs were embedded in the ZIF-67 and BIF-66 matrices by incipient wetness impregnation. Au@ZIF-67 and Au@BIF-66 hybrids were studied for the first time in the liquid phase hydroamination of phenylacetylene with aniline in an air atmosphere and have shown high activity and selectivity in respect to imine in this process. The pronounced impact of the nature of the metal-organic carrier, Au source, and reducing agent on the catalytic performance of the synthesized nanomaterials was found. To the best of our knowledge, it is the first example of using the zeolitic imidazolate framework and boron-imidazolate framework as the components of the gold-containing catalytic systems for the alkyne hydroamination.
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Chronic obstructive pulmonary disease (COPD) is multifactorial disease, which is characterized by airflow limitation and can be provoked by genetic factors, including carriage of the PiZ allele of the protease inhibitor (Pi) gene, encoding alpha-1 antitrypsin (A1AT). Both homozygous and heterozygous PiZ allele carriers can develop COPD. It was found recently that normal A1AT regulates cytokine levels, including IL-17, which is involved in COPD progression. The aim of this study was to determine whether homozygous or heterozygous PiZ allele carriage leads to elevated level of IL-17 and other proinflammatory cytokines in COPD patients. Materials and Methods. Serum samples and clinical data were obtained from 44 COPD patients, who included 6 PiZZ, 8 PiMZ, and 30 PiMM A1AT phenotype carriers. Serum concentrations of IL-17, IL-6, IL-8, IFN-γ, and TNF-α were measured by the enzyme-linked immunosorbent assay (ELISA). All A1AT phenotypes were verified by narrow pH range isoelectrofocusing with selective A1AT staining. A turbidimetric method was used for quantitative A1AT measurements. Results. COPD patients with both PiZZ and PiMZ phenotypes demonstrated elevated IL-17 and decreased IFN-γ levels in comparison to patients with the PiMM phenotype of A1AT. Thereafter, the ratio IL-17/IFN-γ in PiZZ and PiMZ groups greatly exceeded the values of the PiMM group. Homozygous PiZ allele carriers also had significantly higher levels of IL-6 and lower levels of IL-8, and IL-6 values correlated negatively with A1AT concentrations. Conclusions. The presence of the PiZ allele in both homozygous and heterozygous states is associated with altered serum cytokine levels, including elevated IL-17, IL-17/IFN-γ ratio, and IL-6 (only PiZZ), but lower IFN-γ and IL-8.