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1.
Chem Mater ; 36(14): 7056-7068, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39070667

RESUMO

Neodymium tritelluride is a layered van der Waals material, with correlated electronic properties including high electronic mobility, charge density waves, and antiferromagnetism. We developed a solution synthesis method to form free-standing nanosheets of NdTe3, with nanosheet lateral dimensions of 200-400 nm. The morphology of the nanosheet was influenced by the neodymium precursor. When Nd[(N(SiMe3)2]3 was used as the metal source the nanosheet thickness average was 12 ± 2.5 nm, alternatively the combination of NdCl3 and Li(N(SiMe3)2) led to thicker nanosheets, approximately 19 ± 2.4 nm. We believe that the difference in thickness and changes in surface chemistry point to the role of chloride in accelerating nanocrystal growth for the synthesis with NdCl3 (and Li(N(SiMe3)2). Both types of nanosheets exhibit charge density wave (CDW) distortions as measured using electron diffraction and investigated using variable temperature Raman scattering. Interestingly, the magnetic studies suggest a distinct change in properties between 12 and 19 nm thickness in antiferromagnetic NdTe3.

2.
PLoS One ; 19(5): e0299705, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38701086

RESUMO

Whenever we are confronted with action opportunities in everyday life, e.g., when passing an opening, we rely on our ability to precisely estimate our own bodily capabilities in relation to the environmental conditions. So-called affordance judgments can be affected after brain damage. Previous studies with healthy adults showed that such judgments appeared to be trainable within one session. In the current study, we examined whether stroke patients with either right brain damage (n = 30) or left brain damage (n = 30) may similarly profit from training in an aperture task. Further, the role of neuropsychological deficits in trainability was investigated. In the administered task, stroke patients decided whether their hand would fit into a presented opening with varying horizontal width (Aperture Task). During one training session, patients were asked to try to fit their hand into the opening and received feedback on their decisions. We analyzed accuracy and the detection theory parameters perceptual sensitivity and judgment tendency. Both patients with right brain damage and patients with left brain damage showed improved performance during training as well as post training. High variability with differential profiles of trainability was revealed in these patients. Patients with impaired performance in a visuo-spatial or motor-cognitive task appeared to profit considerably from the target-driven action phase with feedback, but the performance increase in judgments did not last when the action was withdrawn. Future studies applying lesion analysis with a larger sample may shed further light on the dissociation in the trainability of affordance judgments observed in patients with versus without visuo-spatial or motor-cognitive deficits.


Assuntos
Julgamento , Acidente Vascular Cerebral , Humanos , Masculino , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/psicologia , Feminino , Pessoa de Meia-Idade , Idoso , Lateralidade Funcional/fisiologia , Desempenho Psicomotor/fisiologia , Adulto
3.
Inorg Chem ; 62(27): 10635-10644, 2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37358196

RESUMO

Rare-earth manganese pyrochlores (R2Mn2O7) are frustrated magnetic materials, which previously have only been accessed using expensive high-pressure and high-temperature synthesis. In the present work, we demonstrate a convenient synthetic approach to synthesize R2Mn2O7 pyrochlores at ambient pressure. A series of pyrochlores (R = Y, Ho-Lu) were prepared by a simple and cost-effective molten salt method using NaCl and KCl as the flux. Moreover, phase-selectivity was demonstrated for yttrium manganese oxides (YMnO3 and Y2Mn2O7) by a simple variation of synthesis temperature and precursors-to-chlorides ratio. The synthetic procedure does not require high pressures or temperatures nor oxygen flow. All synthesized pyrochlores demonstrated ferromagnetic behavior at low temperature, and the magnetic properties were in good agreement with those of high-pressure-synthesized materials. The versatility of the method was confirmed by the preparation of a mixed-rare earth Y0.4Er0.4Tm0.4Yb0.4Lu0.4Mn2O7 solid solution─a compositionally complex high-entropy oxide.

4.
Front Psychol ; 14: 1012586, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36936001

RESUMO

When it comes to the selection of adequate movements, people may apply varying strategies. Explicit if-then rules, compared to implicit prospective action planning, can facilitate action selection in young healthy adults. But aging alters cognitive processes. It is unknown whether older adults may similarly, profit from a rule-based approach to action selection. To investigate the potential effects of aging, the Rule/Plan Motor Cognition (RPMC) paradigm was applied to three different age groups between 31 and 90 years of age. Participants selected grips either instructed by a rule or by prospective planning. As a function of age, we found a general increase in a strategy-specific advantage as quantified by the difference in reaction time between plan- and rule-based action selection. However, in older age groups, these differences went in both directions: some participants initiated rule-based action selection faster, while for others, plan-based action selection seemed more efficient. The decomposition of reaction times into speed of the decision process, action encoding, and response caution components suggests that rule-based action selection may reduce action encoding demands in all age groups. There appears a tendency for the younger and middle age groups to have a speed advantage in the rule task when it comes to information accumulation for action selection. Thus, one influential factor determining the robustness of the rule-based efficiency effect across the lifespan may be presented by the reduced speed of information uptake. Future studies need to further specify the role of these parameters for efficient action selection.

5.
Front Psychol ; 14: 1270437, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38239458

RESUMO

Introduction: In the 21st century, digital devices have become integral to our daily lives. Still, practical assessments designed to evaluate an individual's digital tool competencies are absent. The present study introduces the "Digital Tools Test" ("DIGI"), specifically designed for the evaluation of one's proficiency in handling common applications and functions of smartphones and tablets. The DIGI assessment has been primarily tailored for prospective use among older adults and neurological patients with the latter frequently suffering from so-called apraxia, which potentially also affects the handling of digital tools. Similar to traditional tool use tests that assess tool-selection and tool-action processes, the DIGI assessment evaluates an individual's ability to select an appropriate application for a given task (e.g., creating a new contact), their capacity to navigate within the chosen application and their competence in executing precise and accurate movements, such as swiping. Methods: We tested the implementation of the DIGI in a group of 16 healthy adults aged 18 to 28 years and 16 healthy adults aged 60 to 74 years. All participants were able to withstand the assessment and reported good acceptance. Results: The results revealed a significant performance disparity, with older adults displaying notably lower proficiency in the DIGI. The DIGI performance of older adults exhibited a correlation with their ability to employ a set of novel mechanical tools, but not with their ability to handle a set of familiar common tools. There was no such correlation for the younger group. Conclusion: In conclusion, this study introduces an innovative assessment tool aimed at evaluating common digital tool competencies. Our preliminary results demonstrate good acceptance and reveal expected group differences. For current cohorts of older adults, the results seem to indicate that the ability to use novel tools may aid digital tool use. In the next step, the psychometric properties of the DIGI assessment should be evaluated in larger and more diverse samples. The advancement of digital tool competency assessments and rehabilitation strategies is essential when we aim at facilitating societal inclusion and participation for individuals in affected populations.

6.
Artigo em Inglês | MEDLINE | ID: mdl-36283049

RESUMO

We have investigated the mechanism of relaxivity for two magnetic resonance imaging contrast agents that both employ a cluster-nanocarrier design. The first system termed Mn8Fe4-coPS comprises the cluster Mn8Fe4O12(L)16(H2O)4 or Mn8Fe4 (1) (L = carboxylate) co-polymerized with polystyrene to form ∼75 nm nanobeads. The second system termed Mn3Bpy-PAm used the cluster Mn3(O2CCH3)6(Bpy)2 or Mn3Bpy (2) where Bpy = 2,2'-bipyridine, entrapped in ∼180 nm polyacrylamide nanobeads. Here, we investigate the rate of water exchange of the two clusters, and corresponding cluster-nanocarriers, in order to elucidate the mechanism of relaxivity in the cluster-nanocarrier. Swift-Connick analysis of O-17 NMR was used to determine the water exchange rates of the clusters and cluster-nanocarriers. We found distinct differences in the water exchange rate between Mn8Fe4 and Mn8Fe4-coPS, and we utilized these differences to elucidate the nanobead structure. Using the transverse relaxivity from O-17 NMR line widths, we were able to determine the hydration state of the Mn3Bpy (2) cluster as well as Mn3Bpy-PAm. Using these hydration states in the Swift-Connick analysis of O-17 NMR, we found the water exchange rate to be extremely close in value for the cluster Mn3Bpy and cluster-nanocarrier Mn3Bpy-PAm.

7.
Inorg Chem ; 61(39): 15547-15557, 2022 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-36112414

RESUMO

The luminescence properties of two divalent europium complexes of the type Eu[N(SPPh2)2]2(THF)2 (1) and Eu[N(SePPh2)2]2(THF)2 (2) were investigated. The first complex, Eu[N(SPPh2)2]2(THF)2 (1), was found to be isomorphous with the reported structure of complex 2 and exhibited room temperature luminescence with thermochromic emission upon cooling. We found the complex Eu[N(SePPh2)2]2(THF)2 (2) was also thermochromic but the emission intensity was sensitive to temperature. Both room temperature and low temperature (100 K) single crystal X-ray structural investigation of 1 and 2 indicate geometric distortions of the metal coordination, which may be important for understanding the thermochromic behavior of these complexes. The trivalent europium complex Eu[N(SPPh2)2]3 (3) with the same ligand as 1 was also structurally characterized as a function of temperature and exhibited temperature-dependent luminescence intensity, with no observable emission at room temperature but intense luminescence at 77 K. Variable temperature Raman spectroscopy was used to determine the onset temperature of luminescence of Eu[N(SPPh2)2]3 (3), where the 615 nm (5D0 → 7F2 transition) peak was quenched above 130 K. The UV-visible diffuse reflectance of 3 provides evidence of an LMCT band, supporting a mechanism of thermally activated LMCT quenching of Eu(III) emitting states. A series of ten isomorphous, trivalent lanthanide complexes of type Ln[N(SPPh2)2]3 (Ln = Eu (3) Pr (4), Nd (5), Sm (6), Gd (7), Tb (8)) and Ln[N(SePPh2)2]3 (Ln = Pr (9), Nd (10, structure was previously reported), Sm (11), and Gd (12) for Q = Se) were also synthesized and structurally characterized. These complexes for Ln = Pr, Nd, Sm, and Tb exhibited room temperature luminescence. This study provides examples of temperature-dependent luminescence of both Eu2+ and Eu3+, and the use of soft-atom donor ligands to sensitize lanthanide luminescence in a range of trivalent lanthanides, spanning near IR and visible emitters.

8.
Sci Rep ; 12(1): 5401, 2022 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-35354889

RESUMO

Efficient movement selection is crucial in everyday activities. Whether this function is governed by our stress system is so far unknown. In the current study, data from thirty-six young male adults were analyzed. They performed rule- and plan-based movement selection tasks before (session 1) and after (session 2) a psychosocial stressor, or after a control condition without additional social stressor. Results showed that the rule-based efficiency advantage which was observed prior to the psychosocial stressor was significantly reduced afterwards in the whole sample, as well as in the stress group. Regression analyses revealed that this effect was due to a modulation of the plan-based approach. Especially variations-both increase and decrease-in the parasympathetic activity (reflected by the heart rate variability measure RMSSD) appeared to be disadvantageous for plan-based movement selection improvement. In contrast, performance in the rule-based movement selection tasks appeared to be rather invariant to external influences. The current results suggest that autonomic nervous system activity might modulate motor-cognitive performance. This modulatory capability might be selective for plan-based approaches, hence the applied strategy to movement selection could be decisive when it comes to the vulnerability of motor-cognitive processes towards psychosocial stress.


Assuntos
Movimento , Estresse Psicológico , Sistema Nervoso Autônomo , Humanos , Masculino
9.
Cortex ; 146: 1-23, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34801831

RESUMO

100 years ago, Liepmann highlighted the role of left ventro-dorsal lesions for impairments in conceptual (rather ventral) and motor (more dorsal) related aspects of apraxia. Many studies thereafter attributed to an extended left fronto-temporo-parietal network. Yet, to date there are only few studies that looked at apraxic performance in the selection and application of familiar versus novel tools. In the current study we applied modern voxel-based lesion-symptom mapping (VLSM) to analyze neural correlates of impaired selection and application of familiar versus novel tools. 58 left (LBD) and 51 right brain damaged (RBD) stroke patients participated in the Novel Tools Test (NTT) and the Familiar Tools Test (FTT) of the Diagnostic Instrument for Limb Apraxia (DILA-S). We further assessed performance in control tasks, namely semantic knowledge (BOSU), visuo-spatial working memory (Corsi Block Tapping) and meaningless imitation of gestures (IML). Impaired tool use was most pronounced after LBD. Our VLSM results in the LBD group suggested that selection- versus application-related aspects of praxis and semantics of familiar versus novel tool use can be behaviorally and neuro-anatomically differentiated. For impairments in familiar tool tasks, the major focus of lesion maps was rather ventral while deficiencies in novel tool tasks went along with rather dorsal lesions. Affected selection processes were linked to rather anterior lesions, while impacted application processes went along with rather posterior lesion maps. In our study, particular tool selection processes were rather specific for familiar versus novel tools. Foci for lesion overlaps of experimental and control tasks were noticed ventrally for semantic knowledge and FTT, in fronto-parietal regions for working memory and NTT, and ventro-dorsally for imitation of meaningless gestures and the application of NTT and FTT. We visualized our current interpretation within a neuroanatomical model for apraxia of tool use.


Assuntos
Apraxias , Acidente Vascular Cerebral , Lateralidade Funcional , Gestos , Humanos , Comportamento Imitativo , Imageamento por Ressonância Magnética , Acidente Vascular Cerebral/complicações
10.
ACS Omega ; 6(33): 21719-21729, 2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34471774

RESUMO

This work presents a rapid and facile way to access the cell wall of wood with magnetic nanoparticles (NPs), providing insights into a method of wood modification to prepare hybrid bio-based functional materials. Diffusion-driven infiltration into Scots pine (Pinus sylvestris L.) sapwood was achieved using colloidal Fe3O4 nanoparticles. Optical microscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy, transmission electron microscopy, and X-ray powder diffraction analyses were used to detect and assess the accessibility of the cell wall to Fe3O4. The structural changes, filling of tracheids (cell lumina), and NP infiltration depth were further evaluated by performing X-ray microcomputed tomography analysis. Fourier transform infrared spectroscopy was used to assess the chemical changes in Scots pine induced by the interaction of the wood with the solvent. The thermal stability of Fe3O4-modified wood was studied by thermogravimetric analysis. Successful infiltration of the Fe3O4 NPs was confirmed by measuring the magnetic properties of cross-sectioned layers of the modified wood. The results indicate the feasibility of creating multiple functionalities that may lead to many future applications, including structural nanomaterials with desirable thermal properties, magnetic devices, and sensors.

11.
BMJ Case Rep ; 14(8)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34413042

RESUMO

The most commonly considered infection with a Bartonella species is cat-scratch disease caused by Bartonella henselae Here, we discuss a unique case of a 60-year-old man who presented with Bartonella infection complicated by nosocomial COVID-19. He was admitted with a history of chest pain, persistent fever, rash and influenza-like symptoms. Positive Bartonella serology confirmed diagnosis and the patient developed complications of pericardial effusion in addition to COVID-19 infection, requiring non-invasive ventilation and admission to the intensive care unit. We discuss his symptoms, investigations, treatment and outcomes, while also highlighting the challenges of assessing patients presenting with fever of unknown origin during the COVID-19 pandemic.


Assuntos
Infecções por Bartonella , COVID-19 , Infecção Hospitalar , Febre de Causa Desconhecida , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , SARS-CoV-2
12.
Angew Chem Int Ed Engl ; 60(43): 23134-23141, 2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34424583

RESUMO

In targeting reduced valent lanthanide chalcogenides, we report the first nanoparticle synthesis of the mixed-valent ferromagnets Eu3 S4 and EuSm2 S4 . Using divalent lanthanide halides with bis(trimethylsilyl)sulfide and oleylamine, we prepared nanoparticles of EuS, Eu3 S4 , EuSm2 S4 , SmS1.9 , and Sm3 S4 . All nanoparticle phases were identified using powder X-ray diffraction, transmission electron microscopy was used to confirm morphology and nanoparticle size, and magnetic susceptibility measurements for determining the ordering temperatures and valence. The UV/Vis, Raman and X-ray photoelectron spectroscopies for each phase were compared. Surprisingly, the phase is influenced by the halide and the reaction temperature, where EuCl2 formed EuS while EuI2 formed Eu3 S4 , highlighting the role of kinetics in phase stabilization. Interestingly, at lower temperatures EuI2 initially forms EuS, and converts over time to Eu3 S4 .

13.
ACS Appl Mater Interfaces ; 13(33): 39042-39054, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34375073

RESUMO

In developing a cluster-nanocarrier design, as a magnetic resonance imaging contrast agent, we have investigated the enhanced relaxivity of a manganese and iron-oxo cluster grafted within a porous polystyrene nanobead with increased relaxivity due to a higher surface area. The synthesis of the cluster-nanocarrier for the cluster Mn8Fe4O12(O2CC6H4CH═CH2)16(H2O)4, cross-linked with polystyrene (the nanocarrier), under miniemulsion conditions is described. By including a branched hydrophobe, iso-octane, the resulting nanobeads are porous and ∼70 nm in diameter. The increased surface area of the nanobeads compared to nonporous nanobeads leads to an enhancement in relaxivity; r1 increases from 3.8 to 5.2 ± 0.1 mM-1 s-1, and r2 increases from 11.9 to 50.1 ± 4.8 mM-1 s-1, at 9.4 teslas, strengthening the potential for T1 and T2 imaging. Several metrics were used to assess stability, and the porosity produced no reduction in metal stability. Synchrotron X-ray fluorescence microscopy was used to demonstrate that the nanobeads remain intact in vivo. In depth, physicochemical characteristics were determined, including extensive pharmacokinetics, in vivo imaging, and systemic biodistribution analysis.


Assuntos
Materiais Biocompatíveis/química , Meios de Contraste/química , Ferro/química , Manganês/química , Nanopartículas/química , Compostos Organometálicos/química , Poliestirenos/química , Animais , Materiais Biocompatíveis/farmacocinética , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular , Sobrevivência Celular/efeitos dos fármacos , Meios de Contraste/farmacocinética , Reagentes de Ligações Cruzadas/química , Humanos , Imageamento por Ressonância Magnética , Camundongos Endogâmicos BALB C , Imagem Multimodal , Porosidade , Espectrometria por Raios X , Distribuição Tecidual
14.
ACS Biomater Sci Eng ; 7(8): 3586-3593, 2021 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-34318657

RESUMO

In the present work, a series of zinc whitlockite (CaxZny(HPO4)2(PO4)12) powders was synthesized by a low-temperature dissolution-precipitation process for the first time. The phase conversion from calcium hydroxyapatite to zinc whitlockite occurred in an acidic medium in the presence of Zn2+ ions. Variable chemical composition of the synthesis products was achieved by changing Ca-to-Zn molar ratio in the reaction mixture. Investigation of the phase evolution as a function of time demonstrated that phase-pure zinc whitlockite powders can be synthesized in just 3 h. It is also demonstrated that single-phase products can be obtained when the Ca-to-Zn ratio in the reaction medium is in the range from 9 to 30. With higher or lower ratios, neighboring crystal phases such as scholzite or calcium hydroxyapatite were obtained. The morphology of the synthesized powders was found to be dependent on the chemical composition, transforming from hexagonal to rhombohedral plates with the increase of Zn content. Thermal stability studies revealed that the synthesized compounds were thermally unstable and decomposed upon heat treatment.


Assuntos
Durapatita , Zinco , Fosfatos de Cálcio , Solubilidade , Difração de Raios X
15.
BMC Cancer ; 20(1): 458, 2020 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-32448184

RESUMO

BACKGROUND: Although cancer-related fatigue (CRF) has gained increased attention in the past decade, therapy remains a challenge. Treatment programs are more likely to be effective if the needs and interests of the persons involved are well represented. This can be achieved by stakeholder engagement. In this paper, different key stakeholders' experiences and views on the feasibility of treating CRF in the context of supportive care in hospital environments are analyzed. METHOD: In a qualitative study with the aim of developing an integrative treatment program for CRF, a total of 22 stakeholders (6 medical oncologists, 5 nurses, 9 patients, 1 patient family member, 1 representative of the Swiss Cancer League) were interviewed either in a face-to-face (n = 12) or focus group setting (n = 2). For data analyses, the method of qualitative content analysis was used. RESULTS: The stakeholders referred to different contextual factors when talking about the feasibility of treating CRF in the context of supportive care in hospital environments. These included: assessment, reporting and information; treatability; attitude; infrastructure, time-management, costs and affordability; and integrative approach. CONCLUSIONS: Key factors of a feasible treatment approach to CRF are a coherent, cost effective integrative treatment program facilitated by an interdisciplinary team of health care providers. Furthermore, the treatment approach should be patient orientated, adopting an individualized approach. The major challenges of making the integrative treatment program feasible for CRF are resources and interprofessional collaboration.


Assuntos
Atenção à Saúde/estatística & dados numéricos , Família/psicologia , Fadiga/terapia , Pessoal de Saúde/psicologia , Neoplasias/terapia , Oncologistas/psicologia , Participação do Paciente/psicologia , Adulto , Idoso , Terapia Combinada , Fadiga/etiologia , Fadiga/psicologia , Estudos de Viabilidade , Feminino , Grupos Focais , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/complicações , Neoplasias/patologia , Prognóstico , Pesquisa Qualitativa
16.
Chem Commun (Camb) ; 56(43): 5843-5846, 2020 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-32330217

RESUMO

Using magnetic circular dichroism (MCD) spectroscopy, we demonstrate giant temperature- and field-dependent conduction-band splittings in colloidal EuS and EuSe nanocrystals.

17.
Chemistry ; 26(26): 5872-5886, 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-31999859

RESUMO

Uranium(IV) complexation by 2-furoic acid (2-FA) was examined to better understand the effects of ligand identity and reaction conditions on species formation and stability. Five compounds were isolated: [UCl2 (2-FA)2 (H2 O)2 ]n (1), [U4 Cl10 O2 (THF)6 (2-FA)2 ]⋅2 THF (2), [U6 O4 (OH)4 (H2 O)3 (2-FA)12 ]⋅7 THF⋅H2 O (3), [U6 O4 (OH)4 (H2 O)2 (2-FA)12 ]⋅8.76 H2 O (4), and [U38 Cl42 O54 (OH)2 (H2 O)20 ]⋅m H2 O⋅n THF (5). The structures were determined by single-crystal X-ray diffraction and further characterized by Raman, IR, and optical absorption spectroscopy. The thermal stability and magnetic behavior of the compounds were also examined. Variations in the synthetic conditions led to notable differences in the structural units observed in the solid state. At low H2 O/THF ratios, a tetranuclear oxo-bridged [U4 O2 ] core was isolated. Aging of this solution resulted in the formation a U38 oxo cluster capped by chloro and water ligands. However, at increasing water concentrations only hexanuclear units were observed. In all cases, at temperatures of 100-120 °C, UO2 nanoparticles formed.

18.
ACS Appl Mater Interfaces ; 11(20): 18153-18164, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-30964631

RESUMO

There is an increasing need for gadolinium-free magnetic resonance imaging (MRI) contrast agents, particularly for patients suffering from chronic kidney disease. Using a cluster-nanocarrier combination, we have identified a novel approach to the design of biomedical nanomaterials and report here the criteria for the cluster and the nanocarrier and the advantages of this combination. We have investigated the relaxivity of the following manganese oxo clusters: the parent cluster Mn3(O2CCH3)6(Bpy)2 (1) where Bpy = 2,2'-bipyridine and three new analogs, Mn3(O2CC6H4CH═CH2)6(Bpy)2 (2), Mn3(O2CC(CH3)═CH2)6(Bpy)2 (3), and Mn3O(O2CCH3)6(Pyr)2 (4) where Pyr = pyridine. The parent cluster, Mn3(O2CCH3)6(Bpy)2 (1), had impressive relaxivity ( r1 = 6.9 mM-1 s-1, r2 = 125 mM-1 s-1) and was found to be the most amenable for the synthesis of cluster-nanocarrier nanobeads. Using the inverse miniemulsion polymerization technique (1) in combination with the hydrophilic monomer acrylamide, we synthesized nanobeads (∼125 nm diameter) with homogeneously dispersed clusters within the polyacrylamide matrix (termed Mn3Bpy-PAm). The nanobeads were surface-modified by co-polymerization with an amine-functionalized monomer. This enabled various postsynthetic modifications, for example, to attach a near-IR dye, Cyanine7, as well as a targeting agent. When evaluated as a potential multimodal MRI contrast agent, high relaxivity and contrast were observed with r1 = 54.4 mM-1 s-1 and r2 = 144 mM-1 s-1, surpassing T1 relaxivity of clinically used Gd-DTPA chelates as well as comparable T2 relaxivity to iron oxide microspheres. Physicochemical properties, cellular uptake, and impacts on cell viability were also investigated.


Assuntos
Resinas Acrílicas , Meios de Contraste , Gadolínio DTPA , Imageamento por Ressonância Magnética , Imagem Multimodal , Nanopartículas , Neoplasias Experimentais/diagnóstico por imagem , Resinas Acrílicas/química , Resinas Acrílicas/farmacologia , Animais , Meios de Contraste/química , Meios de Contraste/farmacologia , Gadolínio DTPA/química , Gadolínio DTPA/farmacologia , Humanos , Manganês/química , Manganês/farmacologia , Camundongos , Camundongos Nus , Nanopartículas/química , Nanopartículas/uso terapêutico , Células PC-3
19.
BMJ Paediatr Open ; 3(1): e000543, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31909219

RESUMO

CONTEXT: Behavioural interventions are used to prevent, manage and treat a wide variety of conditions including obesity, diabetes, chronic pain, asthma and emotional difficulties. There has been inadequate attention to the delivery of behavioural interventions to younger children (5-11 years old). OBJECTIVE: Our objectives were to describe the characteristics of behavioural interventions for children aged 5-11 years. DATA SOURCES: We searched five databases: CINAHL, EMBASE, PsycINFO, MEDLINE and Cochrane Library, from January 2005 to August 2019. STUDY SELECTION: The inclusion criteria were (1) children aged 5-11, (2) cognitive and/or behavioural interventions, (3) randomised controlled trials and (4) 2005 onward. Two researchers independently identified studies for inclusion. DATA EXTRACTION: Two researchers independently extracted data from eligible papers. RESULTS: The search identified 10 541 papers. We extracted information on 117 interventions (from 152 papers). Many of the interventions were categorised as complex. This was particularly true for clinical populations; 78.7% were delivered to both the child and parent, and 33.9% took place across multiple settings, typically health and school settings. Most (70.9%) were 'First Wave' (behavioural) interventions, and few (4.3%) were 'Third Wave' (characterised by metacognition, acceptance and mindfulness). Thirty-nine per cent used interactive techniques (play, arts, story and/or games). Purely digital and paper-based interventions were rare, but around a third used these tools as supplements to face-face delivery. There were differences in interventions for younger (5-7 years) and older (8-11 years) children. CONCLUSIONS: Interventions designed and delivered to children should be developmentally sensitive. This review highlights characteristics of interventions delivered to children 5-11 years old: the involvement of the child's parent, using behavioural (rather than cognitive) modalities, using interactive techniques and some interventions were delivered across multiple settings.

20.
Front Psychol ; 9: 309, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29593612

RESUMO

The rule/plan motor cognition (RPMC) paradigm elicits visually indistinguishable motor outputs, resulting from either plan- or rule-based action-selection, using a combination of essentially interchangeable stimuli. Previous implementations of the RPMC paradigm have used pantomimed movements to compare plan- vs. rule-based action-selection. In the present work we attempt to determine the generalizability of previous RPMC findings to real object interaction by use of a grasp-to-rotate task. In the plan task, participants had to use prospective planning to achieve a comfortable post-handle rotation hand posture. The rule task used implementation intentions (if-then rules) leading to the same comfortable end-state. In Experiment A, we compare RPMC performance of 16 healthy participants in pantomime and real object conditions of the experiment, within-subjects. Higher processing efficiency of rule- vs. plan-based action-selection was supported by diffusion model analysis. Results show a significant response-time increase in the pantomime condition compared to the real object condition and a greater response-time advantage of rule-based vs. plan-based actions in the pantomime compared to the real object condition. In Experiment B, 24 healthy participants performed the real object RPMC task in a task switching vs. a blocked condition. Results indicate that plan-based action-selection leads to longer response-times and less efficient information processing than rule-based action-selection in line with previous RPMC findings derived from the pantomime action-mode. Particularly in the task switching mode, responses were faster in the rule compared to the plan task suggesting a modulating influence of cognitive load. Overall, results suggest an advantage of rule-based action-selection over plan-based action-selection; whereby differential mechanisms appear to be involved depending on the action-mode. We propose that cognitive load is a factor that modulates the advantageous effect of implementation intentions in motor cognition on different levels as illustrated by the varying speed advantages and the variation in diffusion parameters per action-mode or condition, respectively.

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