Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
BMC Med Inform Decis Mak ; 21(1): 219, 2021 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-34284765

RESUMEN

BACKGROUND: Polypharmacy is common among older adults and it represents a public health concern, due to the negative health impacts potentially associated with the use of several medications. However, the large number of medication combinations and sequences of use makes it complicated for traditional statistical methods to predict which therapy is genuinely associated with health outcomes. The project aims to use artificial intelligence (AI) to determine the quality of polypharmacy among older adults with chronic diseases in the province of Québec, Canada. METHODS: We will use data from the Quebec Integrated Chronic Disease Surveillance System (QICDSS). QICDSS contains information about prescribed medications in older adults in Quebec collected over 20 years. It also includes diagnostic codes and procedures, and sociodemographic data linked through a unique identification number for each individual. Our research will be structured around three interconnected research axes: AI, Health, and Law&Ethics. The AI research axis will develop algorithms for finding frequent patterns of medication use that correlate with health events, considering data locality and temporality (explainable AI or XAI). The Health research axis will translate these patterns into polypharmacy indicators relevant to public health surveillance and clinicians. The Law&Ethics axis will assess the social acceptability of the algorithms developed using AI tools and the indicators developed by the Heath axis and will ensure that the developed indicators neither discriminate against any population group nor increase the disparities already present in the use of medications. DISCUSSION: The multi-disciplinary research team consists of specialists in AI, health data, statistics, pharmacy, public health, law, and ethics, which will allow investigation of polypharmacy from different points of view and will contribute to a deeper understanding of the clinical, social, and ethical issues surrounding polypharmacy and its surveillance, as well as the use of AI for health record data. The project results will be disseminated to the scientific community, healthcare professionals, and public health decision-makers in peer-reviewed publications, scientific meetings, and reports. The diffusion of the results will ensure the confidentiality of individual data.


Asunto(s)
Inteligencia Artificial , Polifarmacia , Anciano , Enfermedad Crónica , Análisis de Datos , Humanos , Quebec
2.
Front Artif Intell ; 6: 1223924, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37808622

RESUMEN

In the field of automatic text simplification, assessing whether or not the meaning of the original text has been preserved during simplification is of paramount importance. Metrics relying on n-gram overlap assessment may struggle to deal with simplifications which replace complex phrases with their simpler paraphrases. Current evaluation metrics for meaning preservation based on large language models (LLMs), such as BertScore in machine translation or QuestEval in summarization, have been proposed. However, none has a strong correlation with human judgment of meaning preservation. Moreover, such metrics have not been assessed in the context of text simplification research. In this study, we present a meta-evaluation of several metrics we apply to measure content similarity in text simplification. We also show that the metrics are unable to pass two trivial, inexpensive content preservation tests. Another contribution of this study is MeaningBERT (https://github.com/GRAAL-Research/MeaningBERT), a new trainable metric designed to assess meaning preservation between two sentences in text simplification, showing how it correlates with human judgment. To demonstrate its quality and versatility, we will also present a compilation of datasets used to assess meaning preservation and benchmark our study against a large selection of popular metrics.

3.
Bioorg Med Chem Lett ; 22(6): 2283-6, 2012 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-22342124

RESUMEN

The 70-kDa ribosomal protein S6 kinase (p70S6K) is part of the PI3K/AKT/mTOR pathway and has been implicated in cancer. High throughput screening versus p70S6K led to the identification of aminopyrimidine 3a as active inhibitor. Lead optimization of 3a resulted in highly potent, selective, and orally bioavailable pyrazolopyrimidines. In this manuscript we report the structure-activity relationship of this series and pharmacokinetic, pharmacodynamic, and efficacy data of the lead compound 13c.


Asunto(s)
Antineoplásicos/síntesis química , Inhibidores de Proteínas Quinasas/síntesis química , Pirazoles/síntesis química , Pirimidinas/síntesis química , Proteínas Quinasas S6 Ribosómicas 70-kDa/antagonistas & inhibidores , Administración Oral , Animales , Antineoplásicos/farmacocinética , Antineoplásicos/farmacología , Disponibilidad Biológica , Línea Celular Tumoral , Diseño de Fármacos , Ensayos Analíticos de Alto Rendimiento , Humanos , Concentración 50 Inhibidora , Masculino , Ratones , Inhibidores de Proteínas Quinasas/farmacocinética , Inhibidores de Proteínas Quinasas/farmacología , Pirazoles/farmacocinética , Pirazoles/farmacología , Pirimidinas/farmacocinética , Pirimidinas/farmacología , Ratas , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Transducción de Señal , Solubilidad , Relación Estructura-Actividad , Ensayos Antitumor por Modelo de Xenoinjerto
4.
Bioorg Med Chem Lett ; 22(8): 2693-7, 2012 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-22450127

RESUMEN

Activation of the PI3K/Akt/mTOR kinase pathway is frequently associated with human cancer. Selective inhibition of p70S6Kinase, which is the last kinase in the PI3K pathway, is not sufficient for strong tumor growth inhibition and can lead to activation of upstream proteins including Akt through relief of a negative feedback loop. Targeting multiple sites in the PI3K pathway might be beneficial for optimal activity. In this manuscript we report the design of dual Akt/p70S6K inhibitors and the evaluation of the lead compound 11b in vivo, which was eventually advanced into clinical development.


Asunto(s)
Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Pirazoles/síntesis química , Pirazoles/farmacología , Piridinas/síntesis química , Piridinas/farmacología , Proteínas Quinasas S6 Ribosómicas 70-kDa/antagonistas & inhibidores , Animales , Perros , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Haplorrinos , Humanos , Ratones , Microsomas/efectos de los fármacos , Modelos Moleculares , Estructura Molecular , Fosfatidilinositol 3-Quinasas/efectos de los fármacos , Pirazoles/química , Piridinas/química
5.
JMIR Res Protoc ; 11(10): e41012, 2022 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-36191171

RESUMEN

BACKGROUND: The COVID-19 pandemic has generated an explosion in the amount of information shared on the internet, including false and misleading information on SARS-CoV-2 and recommended protective behaviors. Prior to the pandemic, web-based misinformation and disinformation were already identified as having an impact on people's decision to refuse or delay recommended vaccination for themselves or their children. OBJECTIVE: The overall aims of our study are to better understand the influence of web-based misinformation and disinformation on COVID-19 vaccine decisions and investigate potential solutions to reduce the impact of web-based misinformation and disinformation about vaccines. METHODS: Based on different research approaches, the study will involve (1) the use of artificial intelligence techniques, (2) a web-based survey, (3) interviews, and (4) a scoping review and an environmental scan of the literature. RESULTS: As of September 1, 2022, data collection has been completed for all objectives. The analysis is being conducted, and results should be disseminated in the upcoming months. CONCLUSIONS: The findings from this study will help with understanding the underlying determinants of vaccine hesitancy among Canadian individuals and identifying effective, tailored interventions to improve vaccine acceptance among them. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/41012.

6.
J Biomol Screen ; 11(7): 864-9, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16973922

RESUMEN

High-throughput screening (HTS) has become an important part of drug discovery at most pharmaceutical and many biotechnology companies worldwide, and use of HTS technologies is expanding into new areas. Target validation, assay development, secondary screening, ADME/Tox, and lead optimization are among the areas in which there is an increasing use of HTS technologies. It is becoming fully integrated within drug discovery, both upstream and downstream, which includes increasing use of cell-based assays and high-content screening (HCS) technologies to achieve more physiologically relevant results and to find higher quality leads. In addition, HTS laboratories are continually evaluating new technologies as they struggle to increase their success rate for finding drug candidates. The material in this article is based on a 900-page HTS industry report involving 54 HTS directors representing 58 HTS laboratories and 34 suppliers.


Asunto(s)
Evaluación Preclínica de Medicamentos/métodos , Evaluación Preclínica de Medicamentos/tendencias , Células/efectos de los fármacos , Células/metabolismo , Humanos , Preparaciones Farmacéuticas/análisis
7.
J Org Chem ; 62(13): 4266-4276, 1997 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-11671746

RESUMEN

Several 1-mono- and 1,19-bis(p-arylmethyl)-a,c-biladiene salts were prepared and subjected to either copper(II)- or chromium(III)-assisted oxidative cyclization to yield numerous products in which the 1- or 19- substituent is adapted, eliminated, or rearranged to other points on the tetrapyrrole. For example, cyclization using copper(II) acetate of 19-((ethoxycarbonyl)methyl)-2,3,7,8,12,13,17,18-octamethyl-19-(p-tolylmethyl)-a,c-biladiene dihydrobromide (25) yielded the copper(II) 20-((ethoxycarbonyl)methyl)-1-(p-tolylmethyl)-2,3,7,8,12,13,17,18-octamethyl-1,20-dihydroporphyrin (42), copper(II) 20-(ethoxycarbonyl)-3-methylidene-2,3,7,8,12,13,17,18-octamethyl-2-(p-tolylmethyl)chlorin (44), copper(II) 20-(ethoxycarbonyl)-2-methylidene-2,3,7,8,12,13,17,18-octamethyl-3-(p-tolylmethyl)chlorin (45), and three porphyrins: copper(II) 20-(ethoxycarbonyl)-2,3,7,8,12,13,17,18-octamethylporphyrin (3), copper(II) 2,3,7,8,12,13,17,18-octamethyl-20-p-tolylporphyrin (50), and copper(II) 20-(ethoxycarbonyl)-2,3,7,8,12,13,17,18-octamethyl-5-(p-tolylmethyl)porphyrin (47). Formation of porphyrin 47 and the intermediate chlorins 44 and 45 suggests the stepwise migration of the arylmethyl group from the 1-position in compound 42. The isolation of products from cyclization reactions of various 1,19-arylmethyl-substituted a,c-biladiene salts provides further insight into the mechanisms of metal-assisted oxidative cyclization of a,c-biladiene salts to give cyclic tetrapyrroles. Macrocyclizations of a,c-biladienes such as 25 using chromium(III) afford good yields of the metal-free 1-substituted compounds such as 43.

8.
Inorg Chem ; 37(9): 2117-2128, 1998 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-11670364

RESUMEN

The out-of-plane and in-plane distortions of a series of nickel(II) meso-substituted porphyrins with 0, 1, 2, or 4 tert-butyl groups [nickel(II) porphine (NiP), nickel(II) mono-tert-butylporphyrin (NiMtBuP), nickel(II) di-tert-butylporphyrin (NiDtBuP), and nickel(II) tetra-tert-butylporphyrin (NiTtBuP)] are investigated using molecular mechanics (MM) calculations, X-ray crystallography, UV-visible absorption spectroscopy, and resonance Raman spectroscopy. MM calculations are used to predict the stable conformations for this series of porphyrins. The out-of-plane distortions are then analyzed in terms of displacements along the normal coordinates of the porphyrin macrocycle using a new normal-coordinate structural decomposition method. As expected, the distortions are found to occur primarily along the lowest-frequency normal coordinate of each symmetry type and the distortions could be adequately simulated using only the lowest-frequency normal coordinates as a basis (the minimal basis). However, the distortions could be simulated significantly more accurately by extending the minimal basis by including the second-lowest-frequency normal coordinate of all symmetries. Using the extended basis is most important for the in-plane distortions. Detailed analysis of the types of distortion revealed that both the out-of-plane and the in-plane distortions depend on the perturbation symmetry of the peripheral substituents. The symmetry primarily depends on the pattern of substitution (number and positions of substituents) and the orientations of substituents. Often the perturbation symmetry can be predicted for a given porphyrin simply from the possible orientations of the substituents. Then, the main type(s) of symmetric deformation occurring for each possible molecular symmetry can be readily predicted from a D(4)(h)() correlation table. The stable conformers predicted by MM for the series of tert-butyl-substituted porphyrins confirm this simple but informative approach. Experimental verification of the calculated contributions of the symmetric deformations is provided by normal-coordinate structural decomposition of the available X-ray crystal structures of NiP, NiMtBuP, and NiDtBuP. The solid-state results are also supported by the resonance Raman and UV-visible absorption spectroscopic characterization of the porphyrins in solutions. The X-ray crystal structure of NiMtBuP is reported here for the first time.

9.
Org Biomol Chem ; 4(19): 3652-63, 2006 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-16990941

RESUMEN

Two symmetric ditopic supramolecular templates (1 and 2) each presenting two hydrogen bonding recognition subunits were synthesized. Each such subunit comprises the same donor and acceptor pattern, capable of binding a substrate molecule with complementary hydrogen bonding groups to form a supramolecular complex. Substrate molecules, such as thymine or uracil derivatives, yield 2 : 1 complexes with the acceptors involving two hydrogen bonds to each subunit with ideal orientation for subsequent [2 + 2] dimerization upon photoirradiation. Selective syn photoproduct formation and concomitant suppression of the trans isomer are favored by orientation of the two guest nucleobases within the template cleft. Complementary donor and acceptor hydrogen bonding induced positioning of the two substrates and steric hindrance within the template clefts are responsible for the selective product formation.


Asunto(s)
Luz , Timina/química , Catálisis , Cristalografía por Rayos X , Dimerización , Enlace de Hidrógeno , Cinética , Espectroscopía de Resonancia Magnética , Uracilo/química
10.
J Am Chem Soc ; 126(21): 6637-47, 2004 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-15161291

RESUMEN

As examples of supramolecular devices performing chemical (ionic, molecular) control of binding events and models of related natural systems, two molecular conformational switches are described, which display cation-controlled nanomechanical motion coupled to substrate binding and release. The substrate binding relies on donor/acceptor interactions, provided by intercalation between planar sites located at the extremities of the switching units, whereas cation complexation is responsible for conformational regulation. The terpyridine py-py-py-based receptor is activated toward substrate binding upon complexation of a zinc(II) cation and operates in a two-state process. The replacement of the central pyridine by a 4,6-disubstituted pyridimine as in py-pym-py induces a state reversal and yields a new receptor which binds a substrate in the absence of cation, and releases it when copper(I) is introduced, following a three-step process. These systems represent effector-triggered supramolecular switching devices leading toward multistate nanomechanical chemical systems. These two systems illustrate the use of simple conformational switches in the binding site and allosteric regulation of substrate affinity.

11.
Chemistry ; 8(5): 1227-44, 2002 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-11891911

RESUMEN

Supramolecular polymers are described that are derived from the association of two homoditopic heterocomplementary monomers through sextuple hydrogen-bonding arrays. They form fibers and a variety of different materials depending on the conditions. The strong affinity of the DAD-DAD (D=donor, A=acceptor) hydrogen-bonding sites for double-faced cyanuric acid type wedges drives the supramolecular polymeric assembly in apolar and chlorinated organic solvents. The marked influence of stoichiometry, as well as end-capping and cross-linking agents upon fiber formation is revealed in solution and by electron microscopy (EM). The results further contribute to the development of a supramolecular polymer chemistry that comprises reversible polymers formed through recognition-controlled noncovalent connections between the molecular components. Such materials are, by nature, dynamic and present adaptive character in view of their ability to respond to external stimuli.


Asunto(s)
Polímeros/química , Fenómenos Químicos , Química Física , Cristalografía por Rayos X , Enlace de Hidrógeno , Indicadores y Reactivos , Espectroscopía de Resonancia Magnética , Microscopía Electrónica , Modelos Moleculares , Polímeros/síntesis química , Temperatura
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA