Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 7 de 7
Filter
Add more filters










Database
Language
Publication year range
1.
J Clin Exp Neuropsychol ; 45(5): 445-451, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37621191

ABSTRACT

INTRODUCTION: Cognitive assessments, such as the Addenbrooke's Cognitive Examination (ACE-III) and Montreal Cognitive Assessment (MoCA), have been modified for administration using tablet computers. While this offers important advantages for practice, it may also threaten the test validity. The current study sought to test whether administering visuospatial and writing tests using a tablet (finger or stylus drawing), would demonstrate equivalence to traditional pencil and paper administration on ACEmobile. METHOD: This study recruited 26 participants with Alzheimer's disease and 23 healthy older adults. Most participants had low familiarity with using a tablet computer. Participants completed ACEmobile in its entirety, after which they repeated the infinity loops, cube, and clock drawing and sentence writing tests by drawing with a stylus and their finger onto an iPad. Performance on the drawing and writing tests using a stylus, finger, and pencil were compared. RESULTS: Statistically significant differences were observed between the finger and pencil administration on the ACEmobile, with participants performing worse on the finger drawing trials. Differences in scores were most apparent on the sentence writing task. In contrast, no statistical differences were observed between the pencil and stylus administration. DISCUSSION: The findings of this pilot study have important implications for clinical neuropsychology and demonstrate that administering ACEmobile drawing tests with finger drawing is invalid. However, due to the small sample size, a lack of counterbalancing and the narrow range of scores of the dependent variable, we are unable to confidently interpret the validity of stylus drawing. This is an important consideration for future research.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Humans , Aged , Pilot Projects , Fingers , Mental Status and Dementia Tests , Neurologic Examination , Neuropsychological Tests , Cognitive Dysfunction/psychology
2.
Chem Soc Rev ; 50(7): 4382-4410, 2021 Apr 07.
Article in English | MEDLINE | ID: mdl-33594994

ABSTRACT

In this review, the dependence of the photophysical response of chromophores in the confined environments associated with crystalline scaffolds, such as metal-organic frameworks (MOFs), covalent-organic frameworks (COFs), and molecular cages, has been carefully evaluated. Tunability of the framework aperture, cavity microenvironment, and scaffold topology significantly affects emission profiles, quantum yields, or fluorescence lifetimes of confined chromophores. In addition to the role of the host and its effect on the guest, the methods for integration of a chromophore (e.g., as a framework backbone, capping linker, ligand side group, or guest) are discussed. The overall potential of chromophore-integrated frameworks for a wide-range of applications, including artificial biomimetic systems, white-light emitting diodes, photoresponsive devices, and fluorescent sensors with unparalleled spatial resolution are highlighted throughout the review.

3.
Dalton Trans ; 49(33): 11668-11674, 2020 Aug 25.
Article in English | MEDLINE | ID: mdl-32785349

ABSTRACT

Porphyrin based metal organic frameworks (MOFs) have provided a broad platform through which a wide variety of light harvesting applications have been developed. Of particular interest within light harvesting MOFs containing porphyrin chromophores is the extent to which the both environment of the porphyrin and the porphyrin conformation modulate the photophysical properties. With this in mind, a new MOF (RWLAA-1) has been synthesized based on zinc cations linked by zinc(ii) tetra(4-pyridyl)porphyrin (ZnTPyP) and benzene tricarboxylate (H3BTC) linkers in which the porphyrin exhibits significant conformational distortions that have a profound effect on the photophysics of the material including bathochromic shifts in both the optical (Soret and visible bands) and emission bands, reduction in the energy separation between the Q(0,0) and Q(0,1) emission bands and shorter singlet and triplet state lifetimes. These effects are consistent with the porphyrin deformation resulting in changes in the porphyrin electronic structure and excited state conformational dynamics that alter the vibronic coupling between the excited states (S1 and T1) and the S0 ground state.

4.
Inorg Chem ; 59(11): 7761-7767, 2020 Jun 01.
Article in English | MEDLINE | ID: mdl-32421317

ABSTRACT

The Os(II) tris(2,2'-bipyridine) (OsBpy) complex exhibits optical properties that are particularly attractive for light harvesting systems due to the broad absorption spectrum extending throughout the solar spectrum. However, the relatively short lifetime of the triplet metal to ligand charge transfer state (3MLCT) relative to the related Ru(II)tris(2,2'-bipyridine) (RuBpy) has limited applications. Here, the encapsulation of OsBpy within two distinct Zn(II)-trimesic acid MOFs, HKUST-1(Zn) and USF-2 is demonstrated in an effort to extend the 3MLCT lifetime. Encapsulation results in a hypsochromatic shift of the steady-state emission band in both frameworks resulting from a destabilization of the 3MLCT. The encapsulated OsBpy also exhibits extended emission lifetimes in both HKUST-1(Zn) (104 ns in MOF vs 50 ns in methanol) and USF-2 (81 ns in MOF vs 50 ns in methanol) arising from changes in the nonradiative decay constants in both systems. The data are also consistent with vibronic perturbations involved in mixing between higher energy 3MLCT* and ligand field states.

5.
Article in English | MEDLINE | ID: mdl-31074317

ABSTRACT

Reliable information indicated that a half-million prematurely born babies are routinely given antibiotics without evidence of infection. This study is based on a concern that such antibiotics might go into hospital waste systems and lead to antibiotic-resistant bacteria. We tested the removal of selected antibiotics by Octolig, a commercially available supported chelating agent using column chromatography. Five (Caffeine, Ampicillin, Furosemide, Dopamine, and Vancomycin) were selected for study. Ampicillin and Furosemide were quantitatively removed by column chromatography. Dopamine, Caffeine, and Vancomycin were failures. Failures are ascribed to inadequate pKa values (<5) for these three antibiotics.


Subject(s)
Anti-Bacterial Agents/isolation & purification , Chelating Agents/chemistry , Infant, Premature , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , Chromatography/methods , Drug Resistance, Microbial , Filtration/methods , Filtration/standards , Humans , Infant, Newborn , Silica Gel/chemistry , Water/chemistry , Water Purification/standards , Water Quality/standards
6.
Article in English | MEDLINE | ID: mdl-31046561

ABSTRACT

Acetaminophen, a popular NSAID (Non-steroidal anti-inflammatory drug), was studied for efficacy of removal from aqueous solutions. While Octolig® (a polyethylenediimine covalently attached to silica gel) is able to remove many simple anions and some acidic pharmaceuticals having a pKa value less than 4.5, it lacked efficacy with acetaminophen. Accordingly different transition- metal derivatives of Octolig® were tested by column chromatography using as substrates Octolig® derivatives of copper(II), cobalt(II), iron(III), manganese(II), nickel(II), and zinc(II).


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/isolation & purification , Silica Gel/chemistry , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , Water/chemistry , Acetaminophen/isolation & purification , Acetaminophen/pharmacokinetics , Anions , Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics , Chromatography/methods , Cobalt/chemistry , Copper/chemistry , Ferric Compounds/chemistry , Humans , Manganese/chemistry , Nickel/chemistry , Polyethylenes/chemistry , Silica Gel/metabolism , Solutions/chemistry , Water Pollutants, Chemical/pharmacokinetics , Zinc/chemistry
7.
Dalton Trans ; 46(37): 12711-12716, 2017 Sep 26.
Article in English | MEDLINE | ID: mdl-28914295

ABSTRACT

The development of photoactive porous materials is of significant importance for applications ranging from sustainable energy to pharmaceutical development and catalysis. A particularly attractive class of photo-active materials is the metal-organic framework (MOF)-based platform in which the photo-active elements are components of the framework itself or photo-active guests encapsulated within the MOF cavities. It has now been demonstrated that the photo-active [Ru(2,2'-bipyridine)3]2+ (RuBpy) complex can template the formation of MOFs with varying three dimensional structures. Here we report the synthesis and structural and photo-physical characterization of a new RuBpy-templated MOF composed of Cd2+ ions with 1,4-benzenedicarboxylate ligands (RWLC-5) that contains crystallographically resolved RuBpy complexes. The new material displays a biphasic emission decay (130 ns and 1180 ns, T = 20 °C) and a bathochromically shifted emission maximum, relative to RuBpy in solution (603 nm for RuBpy in ethanol vs. 630 nm for RWLC-5). The emission lifetimes also do not display temperature-dependent decays which are characteristic of RuBpy type complexes as well as other RuBpy templated MOFs. The lack of temperature dependence is consistent with the complete deactivation of the 3LF state of the encapsulated RuBpy complex due to a constrained environment. The fast phase decay is attributed to a water molecule hydrogen bonded to a bipyridine ligand associated with ∼38% of the encapsulated RuBpy complexes resulting in the nonradiative deactivation of the 3MLCT state.

SELECTION OF CITATIONS
SEARCH DETAIL
...