Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 133
Filtrar
1.
PLoS One ; 19(3): e0279526, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38451900

RESUMEN

BACKGROUND: The Covid pandemic arrived in Ireland on February 29, 2020. In the following weeks various restrictions were introduced to stem the spread of the disease. Anxiety over the spread of the disease and over the restrictions introduced had an adverse effect upon mental health. This study examines the change in mental health for two groups: young adults aged around 23 at the time of onset of Covid (the 1998 cohort) and a sample of principal carers (PCs) of children who were aged 13 at the onset of Covid (the 2008 cohort). METHODS: Data were obtained from the two cohorts of the longitudinal Growing Up In Ireland (GUI) survey. The sample included 1953 young adults (from the 1998 cohort) and 3547 principal carers (from the 2008 cohort). Mental health as measured by the Centre for Epidemiological Studies Depression-8 scale was obtained for the last pre-Covid wave and for the Covid wave (surveyed in December 2020). Observations for which CES-D8 was not available in either pre or post Covid waves were excluded. Post-Covid sampling weights were applied. The change in depression rates was decomposed into a growth and distribution effect using a Shapley decomposition. The socioeconomic gradient of CES-D8 was examined pre and post Covid using concentration indices and a transition matrix was constructed to examine the dynamics of changes in CES-D8 and depression pre and post-Covid. RESULTS: Relative to the last pre-Covid survey, mental health, as measured by CES-D8 deteriorated for both the young adults of the 1998 cohort and the PCs of the 2008 cohort. For young adults, the deterioration was more pronounced for females. There was no observable socioeconomic gradient for poor mental health amongst young adults, both pre and post Covid. For mothers from the 2008 cohort, a gradient was observed during the pre-COVID-19 pandemic period with poorer mental health status for lower-income and less educated mothers. This gradient was less pronounced post-Covid, the levelling-off arising from a greater deterioration in mental health for higher-income and better-educated PCs. CONCLUSION: Both observed cohorts showed a significant deterioration in mental health post Covid. For young adults the effect was significantly more pronounced among females and this is consistent with generally poorer mental health amongst females in this age group. There was little or no socioeconomic gradient observed for young adults, but the gradient became more shallow for principal carers. Care must be taken in terms of drawing policy implications from this study as the Covid-19 pandemic was arguably a unique event, even allowing for the likelihood of future pandemics. However, the study highlights the vulnerability of young adults, especially females, to the mental health effects arising from major public health shocks.


Asunto(s)
COVID-19 , Salud Mental , Niño , Femenino , Adulto Joven , Humanos , COVID-19/epidemiología , Irlanda/epidemiología , Pandemias , Ansiedad , Estudios Longitudinales , Depresión/epidemiología
2.
Cereb Cortex ; 34(2)2024 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-38185996

RESUMEN

In addition to amyloid beta plaques and neurofibrillary tangles, Alzheimer's disease (AD) has been associated with elevated iron in deep gray matter nuclei using quantitative susceptibility mapping (QSM). However, only a few studies have examined cortical iron, using more macroscopic approaches that cannot assess layer-specific differences. Here, we conducted column-based QSM analyses to assess whether AD-related increases in cortical iron vary in relation to layer-specific differences in the type and density of neurons. We obtained global and regional measures of positive (iron) and negative (myelin, protein aggregation) susceptibility from 22 adults with AD and 22 demographically matched healthy controls. Depth-wise analyses indicated that global susceptibility increased from the pial surface to the gray/white matter boundary, with a larger slope for positive susceptibility in the left hemisphere for adults with AD than controls. Curvature-based analyses indicated larger global susceptibility for adults with AD versus controls; the right hemisphere versus left; and gyri versus sulci. Region-of-interest analyses identified similar depth- and curvature-specific group differences, especially for temporo-parietal regions. Finding that iron accumulates in a topographically heterogenous manner across the cortical mantle may help explain the profound cognitive deterioration that differentiates AD from the slowing of general motor processes in healthy aging.


Asunto(s)
Enfermedad de Alzheimer , Adulto , Humanos , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Mapeo Encefálico , Hierro/metabolismo , Imagen por Resonancia Magnética , Sustancia Gris/diagnóstico por imagen , Sustancia Gris/metabolismo , Placa Amiloide/metabolismo , Encéfalo/metabolismo
3.
Biomedicines ; 12(1)2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38255252

RESUMEN

Age-related macular degeneration (AMD) has recently been linked to cognitive impairment. We hypothesized that AMD modifies the brain aging trajectory, and we conducted a longitudinal diffusion MRI study on 40 participants (20 with AMD and 20 controls) to reveal the location, extent, and dynamics of AMD-related brain changes. Voxel-based analyses at the first visit identified reduced volume in AMD participants in the cuneate gyrus, associated with vision, and the temporal and bilateral cingulate gyrus, linked to higher cognition and memory. The second visit occurred 2 years after the first and revealed that AMD participants had reduced cingulate and superior frontal gyrus volumes, as well as lower fractional anisotropy (FA) for the bilateral occipital lobe, including the visual and the superior frontal cortex. We detected faster rates of volume and FA reduction in AMD participants in the left temporal cortex. We identified inter-lingual and lingual-cerebellar connections as important differentiators in AMD participants. Bundle analyses revealed that the lingual gyrus had a lower streamline length in the AMD participants at the first visit, indicating a connection between retinal and brain health. FA differences in select inter-lingual and lingual cerebellar bundles at the second visit showed downstream effects of vision loss. Our analyses revealed widespread changes in AMD participants, beyond brain networks directly involved in vision processing.

4.
Neuroimage ; 282: 120401, 2023 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-37802405

RESUMEN

Quantitative susceptibility mapping (QSM) is a magnetic resonance imaging (MRI) technique that can assess the magnetic properties of cerebral iron in vivo. Although brain iron is necessary for basic neurobiological functions, excess iron content disrupts homeostasis, leads to oxidative stress, and ultimately contributes to neurodegenerative disease. However, some degree of elevated brain iron is present even among healthy older adults. To better understand the topographical pattern of iron accumulation and its relation to cognitive aging, we conducted an integrative review of 47 QSM studies of healthy aging, with a focus on five distinct themes. The first two themes focused on age-related increases in iron accumulation in deep gray matter nuclei versus the cortex. The overall level of iron is higher in deep gray matter nuclei than in cortical regions. Deep gray matter nuclei vary with regard to age-related effects, which are most prominent in the putamen, and age-related deposition of iron is also observed in frontal, temporal, and parietal cortical regions during healthy aging. The third theme focused on the behavioral relevance of iron content and indicated that higher iron in both deep gray matter and cortical regions was related to decline in fluid (speed-dependent) cognition. A handful of multimodal studies, reviewed in the fourth theme, suggest that iron interacts with imaging measures of brain function, white matter degradation, and the accumulation of neuropathologies. The final theme concerning modifiers of brain iron pointed to potential roles of cardiovascular, dietary, and genetic factors. Although QSM is a relatively recent tool for assessing cerebral iron accumulation, it has significant promise for contributing new insights into healthy neurocognitive aging.


Asunto(s)
Envejecimiento Saludable , Enfermedades Neurodegenerativas , Humanos , Anciano , Hierro/metabolismo , Enfermedades Neurodegenerativas/metabolismo , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Mapeo Encefálico/métodos , Imagen por Resonancia Magnética/métodos , Cognición , Sustancia Gris/diagnóstico por imagen , Sustancia Gris/metabolismo
5.
Neuroimage ; 275: 120191, 2023 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-37244322

RESUMEN

Healthy neurocognitive aging has been associated with the microstructural degradation of white matter pathways that connect distributed gray matter regions, assessed by diffusion-weighted imaging (DWI). However, the relatively low spatial resolution of standard DWI has limited the examination of age-related differences in the properties of smaller, tightly curved white matter fibers, as well as the relatively more complex microstructure of gray matter. Here, we capitalize on high-resolution multi-shot DWI, which allows spatial resolutions < 1 mm3 to be achieved on clinical 3T MRI scanners. We assessed whether traditional diffusion tensor-based measures of gray matter microstructure and graph theoretical measures of white matter structural connectivity assessed by standard (1.5 mm3 voxels, 3.375 µl volume) and high-resolution (1 mm3 voxels, 1µl volume) DWI were differentially related to age and cognitive performance in 61 healthy adults 18-78 years of age. Cognitive performance was assessed using an extensive battery comprising 12 separate tests of fluid (speed-dependent) cognition. Results indicated that the high-resolution data had larger correlations between age and gray matter mean diffusivity, but smaller correlations between age and structural connectivity. Moreover, parallel mediation models including both standard and high-resolution measures revealed that only the high-resolution measures mediated age-related differences in fluid cognition. These results lay the groundwork for future studies planning to apply high-resolution DWI methodology to further assess the mechanisms of both healthy aging and cognitive impairment.


Asunto(s)
Envejecimiento Saludable , Sustancia Blanca , Adulto , Humanos , Sustancia Gris/diagnóstico por imagen , Imagen por Resonancia Magnética , Sustancia Blanca/diagnóstico por imagen , Imagen de Difusión por Resonancia Magnética , Cognición , Encéfalo/diagnóstico por imagen
6.
Chemosphere ; 329: 138531, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37004818

RESUMEN

Water is an essential resource for humans, animals, and plants. Water is also necessary for the manufacture of many products such as milk, textiles, paper, and pharmaceutical composites. During manufacturing, some industries generate a large amount of wastewater containing numerous contaminants. In the dairy industry, for each litre of drinking milk produced, about 10 L of wastewater is generated. Despite this environmental footprint, the production of milk, butter, ice cream, baby formula, etc., are essential in many households. Common contaminants in dairy wastewater include high biological oxygen demand (BOD), chemical oxygen demand (COD), salts as well as nitrogen and phosphorus derivatives. Nitrogen and phosphorus discharges are one of the leading causes in the eutrophication of rivers and oceans. Porous materials have long held significant potential as a disruptive technology for wastewater treatment. However, thus far they have been understudied for use in dairy wastewater treatment. Ordered porous materials, such as zeolites and metal organic frameworks (MOFs), represent classes of porous materials with significant potential for the removal of nitrogen and phosphorus. This review explores the different zeolites and MOFs applied in the removal of nitrogen and phosphorus from wastewater and the prospect of their potential for use in wastewater management in the dairy industry.


Asunto(s)
Estructuras Metalorgánicas , Purificación del Agua , Zeolitas , Animales , Humanos , Aguas Residuales , Fósforo , Nitrógeno/análisis , Purificación del Agua/métodos , Agua , Eliminación de Residuos Líquidos/métodos
7.
Adv Mater ; 35(23): e2209104, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36919615

RESUMEN

Space cooling and heating, ventilation, and air conditioning (HVAC) accounts for roughly 10% of global electricity use and are responsible for ca. 1.13 gigatonnes of CO2 emissions annually. Adsorbent-based HVAC technologies have long been touted as an energy-efficient alternative to traditional refrigeration systems. However, thus far, no suitable adsorbents have been developed which overcome the drawbacks associated with traditional sorbent materials such as silica gels and zeolites. Metal-organic frameworks (MOFs) offer order-of-magnitude improvements in water adsorption and regeneration energy requirements. However, the deployment of MOFs in HVAC applications has been hampered by issues related to MOF powder processing. Herein, three high-density, shaped, monolithic MOFs (UiO-66, UiO-66-NH2 , and Zr-fumarate) with exceptional volumetric gas/vapor uptake are developed-solving previous issues in MOF-HVAC deployment. The monolithic structures across the mesoporous range are visualized using small-angle X-ray scattering and lattice-gas models, giving accurate predictions of adsorption characteristics of the monolithic materials. It is also demonstrated that a fragile MOF such as Zr-fumarate can be synthesized in monolithic form with a bulk density of 0.76 gcm-3 without losing any adsorption performance, having a coefficient of performance (COP) of 0.71 with a low regeneration temperature (≤ 100 °C).

8.
Neurobiol Aging ; 124: 51, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36739620
9.
Atten Percept Psychophys ; 85(3): 749-768, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36627473

RESUMEN

Age-related decline in visual search performance has been associated with different patterns of activation in frontoparietal regions using functional magnetic resonance imaging (fMRI), but whether these age-related effects represent specific influences of target and distractor processing is unclear. Therefore, we acquired event-related fMRI data from 68 healthy, community-dwelling adults ages 18-78 years, during both conjunction (T/F target among rotated Ts and Fs) and feature (T/F target among Os) search. Some displays contained a color singleton that could correspond to either the target or a distractor. A diffusion decision analysis indicated age-related increases in sensorimotor response time across all task conditions, but an age-related decrease in the rate of evidence accumulation (drift rate) was specific to conjunction search. Moreover, the color singleton facilitated search performance when occurring as a target and disrupted performance when occurring as a distractor, but only during conjunction search, and these effects were independent of age. The fMRI data indicated that decreased search efficiency for conjunction relative to feature search was evident as widespread frontoparietal activation. Activation within the left insula mediated the age-related decrease in drift rate for conjunction search, whereas this relation in the FEF and parietal cortex was significant only for individuals younger than 30 or 44 years, respectively. Finally, distractor singletons were associated with significant parietal activation, whereas target singletons were associated with significant frontoparietal deactivation, and this latter effect increased with adult age. Age-related differences in frontoparietal activation therefore reflect both the overall efficiency of search and the enhancement from salient targets.


Asunto(s)
Atención , Percepción Visual , Adulto , Humanos , Adolescente , Adulto Joven , Persona de Mediana Edad , Anciano , Atención/fisiología , Percepción Visual/fisiología , Tiempo de Reacción/fisiología , Lóbulo Parietal/diagnóstico por imagen , Lóbulo Parietal/fisiología , Imagen por Resonancia Magnética
10.
Nat Commun ; 14(1): 156, 2023 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-36631445

RESUMEN

Cellular senescence and the senescence-associated secretory phenotype (SASP) are implicated in aging and age-related disease, and SASP-related inflammation is thought to contribute to tissue dysfunction in aging and diseased animals. However, whether and how SASP factors influence the regenerative capacity of tissues remains unclear. Here, using intestinal organoids as a model of tissue regeneration, we show that SASP factors released by senescent fibroblasts deregulate stem cell activity and differentiation and ultimately impair crypt formation. We identify the secreted N-terminal domain of Ptk7 as a key component of the SASP that activates non-canonical Wnt / Ca2+ signaling through FZD7 in intestinal stem cells (ISCs). Changes in cytosolic [Ca2+] elicited by Ptk7 promote nuclear translocation of YAP and induce expression of YAP/TEAD target genes, impairing symmetry breaking and stem cell differentiation. Our study discovers secreted Ptk7 as a factor released by senescent cells and provides insight into the mechanism by which cellular senescence contributes to tissue dysfunction in aging and disease.


Asunto(s)
Diferenciación Celular , Proteínas Tirosina Quinasas Receptoras , Células Madre , Animales , Ratones , Envejecimiento , Diferenciación Celular/genética , Senescencia Celular/genética , Intestinos/citología , Intestinos/metabolismo , Proteínas Tirosina Quinasas Receptoras/metabolismo , Células Madre/metabolismo , Vía de Señalización Wnt , Proteínas Señalizadoras YAP
11.
Chem Sci ; 13(27): 7990-8002, 2022 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-35919420

RESUMEN

Metal-organic frameworks (MOFs) are one of the most researched designer materials today, as their high tunability offers scientists a wide space to imagine all kinds of possible structures. Their uniquely flexible customisability spurred the creation of hypothetical datasets and the syntheses of more than 100 000 MOFs officially reported in the Cambridge Structural Database. To scan such large numbers of MOFs, computational high-throughput screenings (HTS) have become the customary method to identify the most promising structure for a given application, and/or to spot useful structure-property relationships. However, despite all these data-mining efforts, only a fraction of HTS studies have identified synthesisable top-performing MOFs that were then further investigated in the lab. In this perspective, we review these specific cases and suggest possible steps to push future HTS more systematically towards synthesisable structures.

12.
J Am Chem Soc ; 144(30): 13729-13739, 2022 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-35876689

RESUMEN

We are currently witnessing the dawn of hydrogen (H2) economy, where H2 will soon become a primary fuel for heating, transportation, and long-distance and long-term energy storage. Among diverse possibilities, H2 can be stored as a pressurized gas, a cryogenic liquid, or a solid fuel via adsorption onto porous materials. Metal-organic frameworks (MOFs) have emerged as adsorbent materials with the highest theoretical H2 storage densities on both a volumetric and gravimetric basis. However, a critical bottleneck for the use of H2 as a transportation fuel has been the lack of densification methods capable of shaping MOFs into practical formulations while maintaining their adsorptive performance. Here, we report a high-throughput screening and deep analysis of a database of MOFs to find optimal materials, followed by the synthesis, characterization, and performance evaluation of an optimal monolithic MOF (monoMOF) for H2 storage. After densification, this monoMOF stores 46 g L-1 H2 at 50 bar and 77 K and delivers 41 and 42 g L-1 H2 at operating pressures of 25 and 50 bar, respectively, when deployed in a combined temperature-pressure (25-50 bar/77 K → 5 bar/160 K) swing gas delivery system. This performance represents up to an 80% reduction in the operating pressure requirements for delivering H2 gas when compared with benchmark materials and an 83% reduction compared to compressed H2 gas. Our findings represent a substantial step forward in the application of high-density materials for volumetric H2 storage applications.

13.
Artículo en Inglés | MEDLINE | ID: mdl-35656844

RESUMEN

Controlling the pressure at which liquids intrude (wet) and extrude (dry) a nanopore is of paramount importance for a broad range of applications, such as energy conversion, catalysis, chromatography, separation, ionic channels, and many more. To tune these characteristics, one typically acts on the chemical nature of the system or pore size. In this work, we propose an alternative route for controlling both intrusion and extrusion pressures via proper arrangement of the grains of the nanoporous material. To prove the concept, dynamic intrusion-extrusion cycles for powdered and monolithic ZIF-8 metal-organic framework were conducted by means of water porosimetry and in operando neutron scattering. We report a drastic increase in intrusion-extrusion dynamic hysteresis when going from a fine powder to a dense monolith configuration, transforming an intermediate performance of the ZIF-8 + water system (poor molecular spring) into a desirable shock-absorber with more than 1 order of magnitude enhancement of dissipated energy per cycle. The obtained results are supported by MD simulations and pave the way for an alternative methodology of tuning intrusion-extrusion pressure using a macroscopic arrangement of nanoporous material.

14.
Neurobiol Lang (Camb) ; 3(2): 272-286, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35685085

RESUMEN

As people age, one of the most common complaints is difficulty with word retrieval. A wealth of behavioral research confirms such age-related language production deficits, yet the structural neural differences that relate to age-related language production deficits remains an open area of exploration. Therefore, the present study used a large sample of healthy adults across adulthood to investigate how age-related white matter differences in three key left-hemisphere language tracts may contribute to age-related differences in language ability. Specifically, we used diffusion tensor imaging to measure fractional anisotropy (FA) and radial diffusivity (RD) which are indicators of white matter structure. We then used a series of path models to test whether white matter from the superior longitudinal fasciculus (SLF), the inferior longitudinal fasciculus, and the frontal aslant tract (FAT) mediated age-related differences in one form of language production, picture naming. We found that FA, as well as RD from the SLF and FAT mediated the relation between age and picture naming performance, whereas a control tract (corticospinal) was not a mediator. Moreover, differences between mediation of picture naming and a control naming condition suggest that left SLF has a greater role in higher-order aspects of naming, such as semantic and lexical selection whereas left FAT is more sensitive to sensorimotor aspects of fluency or speech motor planning. These results suggest that dorsal white matter contributes to age-related differences in generating speech and may be particularly important in supporting word retrieval across adulthood.

15.
Adv Mater ; 34(27): e2201502, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35603497

RESUMEN

Porosity and surface area analysis play a prominent role in modern materials science. At the heart of this sits the Brunauer-Emmett-Teller (BET) theory, which has been a remarkably successful contribution to the field of materials science. The BET method was developed in the 1930s for open surfaces but is now the most widely used metric for the estimation of surface areas of micro- and mesoporous materials. Despite its widespread use, the calculation of BET surface areas causes a spread in reported areas, resulting in reproducibility problems in both academia and industry. To prove this, for this analysis, 18 already-measured raw adsorption isotherms were provided to sixty-one labs, who were asked to calculate the corresponding BET areas. This round-robin exercise resulted in a wide range of values. Here, the reproducibility of BET area determination from identical isotherms is demonstrated to be a largely ignored issue, raising critical concerns over the reliability of reported BET areas. To solve this major issue, a new computational approach to accurately and systematically determine the BET area of nanoporous materials is developed. The software, called "BET surface identification" (BETSI), expands on the well-known Rouquerol criteria and makes an unambiguous BET area assignment possible.


Asunto(s)
Reproducibilidad de los Resultados , Adsorción , Porosidad
16.
Hum Brain Mapp ; 43(3): 1047-1060, 2022 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-34854172

RESUMEN

Brain iron dyshomeostasis disrupts various critical cellular functions, and age-related iron accumulation may contribute to deficient neurotransmission and cell death. While recent studies have linked excessive brain iron to cognitive function in the context of neurodegenerative disease, little is known regarding the role of brain iron accumulation in cognitive aging in healthy adults. Further, previous studies have focused primarily on deep gray matter regions, where the level of iron deposition is highest. However, recent evidence suggests that cortical iron may also contribute to cognitive deficit and neurodegenerative disease. Here, we used quantitative susceptibility mapping (QSM) to measure brain iron in 67 healthy participants 18-78 years of age. Speed-dependent (fluid) cognition was assessed from a battery of 12 psychometric and computer-based tests. From voxelwise QSM analyses, we found that QSM susceptibility values were negatively associated with fluid cognition in the right inferior temporal gyrus, bilateral putamen, posterior cingulate gyrus, motor, and premotor cortices. Mediation analysis indicated that susceptibility in the right inferior temporal gyrus was a significant mediator of the relation between age and fluid cognition, and similar effects were evident for the left inferior temporal gyrus at a lower statistical threshold. Additionally, age and right inferior temporal gyrus susceptibility interacted to predict fluid cognition, such that brain iron was negatively associated with a cognitive decline for adults over 45 years of age. These findings suggest that iron may have a mediating role in cognitive decline and may be an early biomarker of neurodegenerative disease.


Asunto(s)
Envejecimiento/fisiología , Corteza Cerebral/fisiología , Disfunción Cognitiva , Inteligencia/fisiología , Hierro/metabolismo , Putamen/fisiología , Adolescente , Adulto , Anciano , Envejecimiento/metabolismo , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/metabolismo , Corteza Cerebral/fisiopatología , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/metabolismo , Disfunción Cognitiva/fisiopatología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Putamen/diagnóstico por imagen , Putamen/metabolismo , Putamen/fisiopatología , Adulto Joven
17.
Mol Genet Metab Rep ; 29: 100810, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34815941

RESUMEN

INTRODUCTION: Current clinical outcome assessments (COAs) are not effectively capturing the complex array of symptoms of adults with phenylketonuria (PKU). This study aimed to identify concepts of interest relevant to adults with PKU. Based on these concepts, COAs for patient-reported outcomes (PROs), observer-reported outcomes (ObsROs), and clinician-reported outcomes (ClinROs) were selected or developed and content validity was assessed. MATERIALS AND METHODS: Concept-elicitation interviews were conducted with an international cohort of adults with PKU (n = 30), family member observers (n = 14), and clinical experts (n = 8). Observers and clinical experts were included to overcome the risk of lack of self-awareness among adults with PKU. The concepts of interests endorsed by ≥30% of patients, observers, and/or clinical experts were selected, mapped to items in existing COAs, and used to develop global impression items for patients, observers, and clinicians. Next, the content validity of the COAs and global impression items was evaluated by cognitive interviews with patients (n = 22), observers (n = 11), and clinical experts (n = 8). All patients were categorized according to blood phenylalanine (Phe) levels (i.e., <600 µmol/L, 600-1200 µmol/L, and >1200 µmol/L). RESULTS: Concepts of interests were identified across four domains: emotional, cognitive, physical, and behavioral. After mapping, eight existing COAs were selected based on the concept coverage (six PROs, one ObsRO, and one ClinRO). The six PRO measures were considered as potentially fit-for-purpose. The ObsRO measure was not deemed relevant for use in observers of adults with PKU and only a subscale of the ClinRO measure was considered valid for assessing adults with PKU by clinicians. Due to the lack of existing COAs covering all concepts of interests, global impression items for symptom severity and change in symptoms were developed, which were limited to one question covering in total 14 concepts. Upon validation, some of the patient and observer global impression items were excluded as they were subject to lack of insight or could not be reported by observers. Due to the limited interaction time between clinician and patient, use of the clinician global impression items was not supported. CONCLUSION: Existing COAs relevant to adults with PKU were selected and PKU-specific global impression items were developed by mapping the most frequently identified concepts of interests from internationally-conducted in-depth interviews. Future studies should address the appropriateness of the selected COAs and global impression items to assess if these can be used as efficacy endpoints in PKU clinical trials.

18.
Langmuir ; 37(47): 13838-13845, 2021 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-34788027

RESUMEN

A combined experimental and theoretical study of C2H2 and CO2 adsorption and separation was performed in two isostructural molecular porous materials (MPMs): MPM-1-Cl ([Cu2(adenine)4Cl2]Cl2) and MPM-1-TIFSIX ([Cu2(adenine)4(TiF6)2]). It was revealed that MPM-1-Cl displayed higher low-pressure uptake, isosteric heat of adsorption (Qst), and selectivity for C2H2 than CO2, whereas the opposite was observed for MPM-1-TIFSIX. While MPM-1-Cl contains only one type of accessible channel, which has a greater preference toward C2H2, MPM-1-TIFSIX contains three distinct accessible channels, one of which is a confined region between two large channels that represents the primary binding site for both adsorbates. According to molecular simulations, the initial adsorption site in MPM-1-TIFSIX interacts more strongly with CO2 than C2H2, thus explaining the inversion of adsorbate selectivity relative to MPM-1-Cl.

19.
J Mater Chem A Mater ; 9(29): 16006-16015, 2021 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-34354834

RESUMEN

Two-dimensional electrically conductive metal-organic frameworks (MOFs) have emerged as promising model electrodes for use in electric double-layer capacitors (EDLCs). However, a number of fundamental questions about the behaviour of this class of materials in EDLCs remain unanswered, including the effect of the identity of the metal node and organic linker molecule on capacitive performance, and the limitations of current conductive MOFs in these devices relative to traditional activated carbon electrode materials. Herein, we address both these questions via a detailed study of the capacitive performance of the framework Cu3(HHTP)2 (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) with an acetonitrile-based electrolyte, finding a specific capacitance of 110-114 F g-1 at current densities of 0.04-0.05 A g-1 and a modest rate capability. By directly comparing its performance with the previously reported analogue, Ni3(HITP)2 (HITP = 2,3,6,7,10,11-hexaiminotriphenylene), we illustrate that capacitive performance is largely independent of the identity of the metal node and organic linker molecule in these nearly isostructural MOFs. Importantly, this result suggests that EDLC performance in general is uniquely defined by the 3D structure of the electrodes and the electrolyte, a significant finding not demonstrated using traditional electrode materials. Finally, we probe the limitations of Cu3(HHTP)2 in EDLCs, finding a limited stable double-layer voltage window of 1 V and only a modest capacitance retention of 81% over 30 000 cycles, both significantly lower than state-of-the-art porous carbons. These important insights will aid the design of future conductive MOFs with greater EDLC performances.

20.
Faraday Discuss ; 231(0): 51-65, 2021 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-34235530

RESUMEN

Carbon dioxide (CO2) is both a primary contributor to global warming and a major industrial impurity. Traditional approaches to carbon capture involve corrosive and energy-intensive processes such as liquid amine absorption. Although adsorptive separation has long been a promising alternative to traditional processes, up to this point there has been a lack of appropriate adsorbents capable of capturing CO2 whilst maintaining low regeneration energies. In the context of CO2 capture, metal-organic frameworks (MOFs) have gained much attention in the past two decades as potential materials. Their tuneable nature allows for precise control over the pore size and chemistry, which allows for the tailoring of their properties for the selective adsorption of CO2. While many candidate materials exist, the amount of research into material shaping for use in industrial processes has been limited. Traditional shaping strategies such as pelletisation involve the use of binders and/or mechanical processes, which can have a detrimental impact on the adsorption properties of the resulting materials or can result in low-density structures with low volumetric adsorption capacities. Herein, we demonstrate the use of a series of monolithic MOFs (monoUiO-66, monoUiO-66-NH2 & monoHKUST-1) for use in gas separation processes.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...