Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Am Chem Soc ; 144(24): 11003-11009, 2022 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-35695094

RESUMEN

The organometallic on-surface synthesis of the eight-membered sp2 carbon-based ring cyclooctatetraene (C8H8, Cot) with the neighboring rare-earth elements ytterbium and thulium yields fundamentally different products for the two lanthanides, when conducted on graphene (Gr) close to the charge neutrality point. Sandwich-molecular YbCot wires of more than 500 Å length being composed of an alternating sequence of Yb atoms and upright-standing Cot molecules result from the on-surface synthesis with Yb. In contrast, repulsively interacting TmCot dots consisting of a single Cot molecule and a single Tm atom result from the on-surface synthesis with Tm. While the YbCot wires are bound through van der Waals interactions to the substrate, the dots are chemisorbed to Gr via the Tm atoms being more electropositive compared to Yb atoms. When the electron chemical potential in Gr is substantially raised (n-doping) through backside doping from an intercalation layer, the reaction product in the synthesis with Tm can be tuned to TmCot sandwich-molecular wires rather than TmCot dots. By use of density functional theory, it is found that the reduced electronegativity of Gr upon n-doping weakens the binding as well as the charge transfer between the reaction intermediate TmCot dot and Gr. Thus, the assembly of the TmCot dots to long TmCot sandwich-molecular wires becomes energetically favorable. It is thereby demonstrated that the electron chemical potential in Gr can be used as a control parameter in an organometallic on-surface synthesis to tune the outcome of a reaction.

2.
Exp Astron (Dordr) ; 54(2-3): 1197-1221, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36915622

RESUMEN

Exoplanet science is one of the most thriving fields of modern astrophysics. A major goal is the atmospheric characterization of dozens of small, terrestrial exoplanets in order to search for signatures in their atmospheres that indicate biological activity, assess their ability to provide conditions for life as we know it, and investigate their expected atmospheric diversity. None of the currently adopted projects or missions, from ground or in space, can address these goals. In this White Paper, submitted to ESA in response to the Voyage 2050 Call, we argue that a large space-based mission designed to detect and investigate thermal emission spectra of terrestrial exoplanets in the mid-infrared wavelength range provides unique scientific potential to address these goals and surpasses the capabilities of other approaches. While NASA might be focusing on large missions that aim to detect terrestrial planets in reflected light, ESA has the opportunity to take leadership and spearhead the development of a large mid-infrared exoplanet mission within the scope of the "Voyage 2050" long-term plan establishing Europe at the forefront of exoplanet science for decades to come. Given the ambitious science goals of such a mission, additional international partners might be interested in participating and contributing to a roadmap that, in the long run, leads to a successful implementation. A new, dedicated development program funded by ESA to help reduce development and implementation cost and further push some of the required key technologies would be a first important step in this direction. Ultimately, a large mid-infrared exoplanet imaging mission will be needed to help answer one of humankind's most fundamental questions: "How unique is our Earth?"

3.
J Biomed Inform ; 100: 103314, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31629921

RESUMEN

Searching for patient cohorts in electronic patient data often requires the definition of temporal constraints between the selection criteria. However, beyond a certain degree of temporal complexity, the non-graphical, form-based approaches implemented in current translational research platforms may be limited when modeling such constraints. In our opinion, there is a need for an easily accessible and implementable, fully graphical method for creating temporal queries. We aim to respond to this challenge with a new graphical notation. Based on Allen's time interval algebra, it allows for modeling temporal queries by arranging simple horizontal bars depicting symbolic time intervals. To make our approach applicable to complex temporal patterns, we apply two extensions: with duration intervals, we enable the inference about relative temporal distances between patient events, and with time interval modifiers, we support counting and excluding patient events, as well as constraining numeric values. We describe how to generate database queries from this notation. We provide a prototypical implementation, consisting of a temporal query modeling frontend and an experimental backend that connects to an i2b2 system. We evaluate our modeling approach on the MIMIC-III database to demonstrate that it can be used for modeling typical temporal phenotyping queries.


Asunto(s)
Gráficos por Computador , Simulación por Computador , Algoritmos , Bases de Datos Factuales , Humanos , Almacenamiento y Recuperación de la Información , Tiempo
4.
J Biomed Inform ; 83: 196-203, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29775771

RESUMEN

OBJECTIVE: The Arden Syntax for Medical Logic Systems is a standard for encoding and sharing medical knowledge in the form of Medical Logic Modules. To improve accessibility for clinicians, the originators of the standard deliberately designed Arden Syntax expressions to resemble natural language, and parentheses around operands are not generally required. For certain patterns of nested expressions, however, the use of parentheses is mandatory, otherwise they are not accepted by an Arden Syntax environment. In this study, we refer to such patterns as anomalies. The purpose of this paper is to investigate the extent and the circumstances of such anomalies, and to outline a solution based on an alternative grammar encoding approach. METHODS: To analyze the distribution of anomalies in nested expressions, we developed two custom-made complementary utilities. The first utility, termed parser, checks a single expression pattern against the specification-compliant grammar for syntactic correctness. The second utility, termed composer, automatically creates an extensive amount of expression patterns by permuting and nesting operators without the use of parentheses, and stores these together with the expected syntactic correctness. By means of these utilities we conducted a comprehensive analysis of anomalies by comparing the expected correctness with the actual correctness. Any detected anomalies are stored into a set of files, grouped by the respective top-level operator, for a subsequent analysis. RESULTS: The composer utility nested 165 unary, binary, or ternary operators of Arden Syntax version 2.8 to a depth of two, resulting in a set of 76,533 expression patterns, of which 18,978 (24.8%) have been identified as anomalies. An automated assessment of their practical relevance for medical knowledge encoding is infeasible. Manual screening of selected samples indicated that only a small proportion of the detected anomalies would be relevant. The cause of the anomalies lies in the encoding of the grammar. A change of the basic encoding approach with some additional customizations eliminates the anomalies. A working expression parser is included in the supplementary material. CONCLUSION: Arden Syntax expressions are affected by anomalies. Since only a small proportion of them have practical relevance and they cannot cause false calculations or clinical decisions, their practical impact is likely limited. However, they may be potential points of confusion for knowledge engineers. An alternative expression grammar, based on a different encoding approach, would not only eliminate the anomalies, but could considerably facilitate both maintenance and further development of the standard.


Asunto(s)
Informática Médica/métodos , Procesamiento de Lenguaje Natural , Lingüística , Lenguajes de Programación , Programas Informáticos
5.
Nature ; 466(7304): 339-42, 2010 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-20631793

RESUMEN

Circumstellar disks are an essential ingredient of the formation of low-mass stars. It is unclear, however, whether the accretion-disk paradigm can also account for the formation of stars more massive than about 10 solar masses, in which strong radiation pressure might halt mass infall. Massive stars may form by stellar merging, although more recent theoretical investigations suggest that the radiative-pressure limit may be overcome by considering more complex, non-spherical infall geometries. Clear observational evidence, such as the detection of compact dusty disks around massive young stellar objects, is needed to identify unambiguously the formation mode of the most massive stars. Here we report near-infrared interferometric observations that spatially resolve the astronomical-unit-scale distribution of hot material around a high-mass ( approximately 20 solar masses) young stellar object. The image shows an elongated structure with a size of approximately 13 x 19 astronomical units, consistent with a disk seen at an inclination angle of approximately 45 degrees . Using geometric and detailed physical models, we found a radial temperature gradient in the disk, with a dust-free region less than 9.5 astronomical units from the star, qualitatively and quantitatively similar to the disks observed in low-mass star formation. Perpendicular to the disk plane we observed a molecular outflow and two bow shocks, indicating that a bipolar outflow emanates from the inner regions of the system.

6.
Mult Scler ; 21(14): 1811-22, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25732840

RESUMEN

OBJECTIVE: We aimed to clarify whether fingolimod has direct effects on antigen-presenting cells in multiple sclerosis patients. METHODS: Frequency and phenotype of directly ex vivo dendritic cells and monocytes were analyzed in 43 individuals, including fingolimod-treated and untreated multiple sclerosis patients as well as healthy subjects. These cells were further stimulated with lipopolysaccharide to determine functional effects of fingolimod treatment. RESULTS: Absolute numbers of CD1c+ dendritic cells and monocytes were not significantly reduced in fingolimod-treated patients indicating that fingolimod did not block the migration of antigen-presenting cells to peripheral blood. CD86 was upregulated on CD1c+ dendritic cells and thus their activation was not impaired under fingolimod treatment. Quantitative analyses of gene transcription in cells and protein content in supernatants from ex vivo CD1c+ dendritic cells and monocytes, however, showed lower secretion of TNFα, IL1-ß and IL-6 upon lipopolysaccharide-stimulation. These results could be matched with CD4+MOG-specific transgenic T cells exhibiting reduced levels of TNFα and IFN-γ but not IL-4 upon stimulation with murine dendritic cells loaded with MOG, when treated with fingolimod. CONCLUSIONS: Our data indicate that fingolimod - apart from trapping lymphocytes in lymph nodes - exerts its disease-modulating activity by rebalancing the immune tolerance networks by modulation of antigen-presenting cells.


Asunto(s)
Citocinas/efectos de los fármacos , Células Dendríticas/efectos de los fármacos , Clorhidrato de Fingolimod/farmacología , Inmunosupresores/farmacología , Monocitos/efectos de los fármacos , Esclerosis Múltiple/sangre , Esclerosis Múltiple/tratamiento farmacológico , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
7.
Brain ; 136(Pt 4): 1048-66, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23518712

RESUMEN

Laquinimod is an orally administered compound that is under investigation in relapsing-remitting multiple sclerosis. To understand the mechanism by which laquinimod exerts its clinical effects, we have performed human and murine studies assessing its immunomodulatory properties. In experimental autoimmune encephalomyelitis, the therapeutic administration of laquinimod beginning during the recovery of SJL mice, prevented further relapses as expected and strongly reduced infiltration of CD4+ and CD8+ T cells in the central nervous system. We hypothesized that this beneficial effect was mediated by dendritic cells, since we and others found a modulation of different dendritic cell subsets under treatment. According to the findings on antigen-presenting cells in the murine system, we found a reduced capacity of human monocyte-derived dendritic cells treated with therapeutic concentrations of laquinimod, upon maturation with lipopolysaccharide, to induce CD4+ T cell proliferation and secretion of pro-inflammatory cytokines. Furthermore, laquinimod treatment of mature dendritic cells resulted in a decreased chemokine production by both murine and human dendritic cells, associated with a decreased monocyte chemo-attraction. In laquinimod-treated patients with multiple sclerosis we consistently found reduced chemokine and cytokine secretion by conventional CD1c+ dendritic cells upon lipopolysaccharide stimulation. Similarly to the animal model of relapsing-remitting multiple sclerosis, dendritic cell subsets were altered in patients upon laquinimod treatment, as the number of conventional CD1c+ and plasmacytoid CD303+ dendritic cells were decreased within peripheral blood mononuclear cells. Moreover, laquinimod treatment in patients with multiple sclerosis and mice modified the maturation of dendritic cells demonstrated by an upregulation of CD86 expression in vivo. Our data suggest that inhibition of the NF-κB pathway is responsible for the changes observed in dendritic cell maturation and functions. These findings indicate that laquinimod exhibits its disease-modulating activity in multiple sclerosis by downregulating immunogenicity of dendritic cell responses. We suggest that monitoring dendritic cell properties in multiple sclerosis should be implemented in future therapeutic trials.


Asunto(s)
Células Dendríticas/patología , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Encefalomielitis Autoinmune Experimental/patología , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Esclerosis Múltiple Recurrente-Remitente/patología , Quinolonas/farmacología , Animales , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/patología , Células Dendríticas/efectos de los fármacos , Células Dendríticas/inmunología , Encefalomielitis Autoinmune Experimental/inmunología , Femenino , Humanos , Ratones , Ratones Endogámicos C57BL , Esclerosis Múltiple Recurrente-Remitente/inmunología , FN-kappa B/efectos de los fármacos , FN-kappa B/inmunología , Quinolonas/administración & dosificación
8.
J Clin Monit Comput ; 28(5): 465-73, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23354988

RESUMEN

The purpose of this study was to introduce clinical decision support (CDS) that exceeds conventional alerting at tertiary care intensive care units. We investigated physicians' functional CDS requirements in periodic interviews, and analyzed technical interfaces of the existing commercial patient data management system (PDMS). Building on these assessments, we adapted a platform that processes Arden Syntax medical logic modules (MLMs). Clinicians demanded data-driven, user-driven and time-driven execution of MLMs, as well as multiple presentation formats such as tables and graphics. The used PDMS represented a black box insofar as it did not provide standardized interfaces for event notification and external access to patient data; enabling CDS thus required periodically exporting datasets for making them accessible to the invoked Arden engine. A client-server-architecture with a simple browser-based viewer allows users to activate MLM execution and to access CDS results, while an MLM library generates hypertext for diverse presentation targets. The workaround that involves a periodic data replication entails a trade-off between the necessary computational resources and a delay of generated alert messages. Web technologies proved serviceable for reconciling Arden-based CDS functions with alternative presentation formats, including tables, text formatting, graphical outputs, as well as list-based overviews of data from several patients that the native PDMS did not support.


Asunto(s)
Sistemas de Apoyo a Decisiones Clínicas , Técnicas de Apoyo para la Decisión , Sistemas de Administración de Bases de Datos , Alemania , Hospitales Universitarios , Humanos , Unidades de Cuidados Intensivos , Informática Médica , Monitoreo Fisiológico , Centros de Atención Terciaria
9.
Nanoscale ; 14(20): 7682-7691, 2022 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-35546135

RESUMEN

From macroscopic heavy-duty permanent magnets to nanodevices, the precise control of the magnetic properties in rare-earth metals is crucial for many applications used in our daily life. Therefore, a detailed understanding and manipulation of the 4f-metals' magnetic properties are key to further boosting the functionalization and efficiency of future applications. We present a proof-of-concept approach consisting of a dysprosium-iridium surface alloy in which graphene adsorption allows us to tailor its magnetic properties. By adsorbing graphene onto a long-range ordered two-dimensional dysprosium-iridium surface alloy, the magnetic 4f-metal atoms are selectively lifted from the surface alloy. This selective skyhook effect introduces a giant magnetic anisotropy in dysprosium atoms as a result of manipulating its geometrical structure within the surface alloy. Introducing and proving this concept by our combined theoretical and experimental approach provides an easy and unambiguous understanding of its underlying mechanism. Our study sets the ground for an alternative path on how to modify the crystal field around 4f-atoms and therefore their magnetic anisotropies.

10.
Appl Clin Inform ; 12(1): 57-64, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33506478

RESUMEN

BACKGROUND: The identification of patient cohorts for recruiting patients into clinical trials requires an evaluation of study-specific inclusion and exclusion criteria. These criteria are specified depending on corresponding clinical facts. Some of these facts may not be present in the clinical source systems and need to be calculated either in advance or at cohort query runtime (so-called feasibility query). OBJECTIVES: We use the Observational Medical Outcomes Partnership (OMOP) Common Data Model (CDM) as the repository for our clinical data. However, Atlas, the graphical user interface of OMOP, does not offer the functionality to perform calculations on facts data. Therefore, we were in search for a different approach. The objective of this study is to investigate whether the Arden Syntax can be used for feasibility queries on the OMOP CDM to enable on-the-fly calculations at query runtime, to eliminate the need to precalculate data elements that are involved with researchers' criteria specification. METHODS: We implemented a service that reads the facts from the OMOP repository and provides it in a form which an Arden Syntax Medical Logic Module (MLM) can process. Then, we implemented an MLM that applies the eligibility criteria to every patient data set and outputs the list of eligible cases (i.e., performs the feasibility query). RESULTS: The study resulted in an MLM-based feasibility query that identifies cases of overventilation as an example of how an on-the-fly calculation can be realized. The algorithm is split into two MLMs to provide the reusability of the approach. CONCLUSION: We found that MLMs are a suitable technology for feasibility queries on the OMOP CDM. Our method of performing on-the-fly calculations can be employed with any OMOP instance and without touching existing infrastructure like the Extract, Transform and Load pipeline. Therefore, we think that it is a well-suited method to perform on-the-fly calculations on OMOP.


Asunto(s)
Algoritmos , Bases de Datos Factuales , Estudios de Cohortes
11.
Artículo en Inglés | MEDLINE | ID: mdl-33203651

RESUMEN

OBJECTIVE: To assess the impact of laquinimod treatment on monocytes and to investigate the underlying immunomodulatory mechanisms in MS. METHODS: In this cross-sectional study, we performed in vivo and in vitro analyses of cluster of differentiation (CD14+) monocytes isolated from healthy donors (n = 15), untreated (n = 13), and laquinimod-treated patients with MS (n = 14). Their frequency and the expression of surface activation markers were assessed by flow cytometry and the viability by calcein staining. Cytokine concentrations in the supernatants of lipopolysaccharide (LPS)-stimulated monocytes were determined by flow cytometry. The messenger ribonucleic acid (mRNA) expression level of genes involved in cytokine expression was measured by quantitative PCR. The LPS-mediated nuclear factor kappa-light-chain-enhancer of activated B-cell (NF-κB) activation was determined by the quantification of the phosphorylation level of the p65 subunit. Laquinimod-treated monocytes were cocultured with CD4+ T cells, and the resulting cytokine production was analyzed by flow cytometry after intracellular cytokine staining. The interleukin (IL)-17A concentration of the supernatant was assessed by ELISA. RESULTS: Laquinimod did not alter the frequency or viability of circulating monocytes, but led to an upregulation of CD86 expression. LPS-stimulated monocytes of laquinimod-treated patients with MS secreted less IL-1ß following a downregulation of IL-1ß gene expression. Phosphorylation levels of the NF-κB p65 subunit were reduced after laquinimod treatment, indicating a laquinimod-associated inhibition of the NF-κB pathway. T cells primed with laquinimod-treated monocytes differentiated significantly less into IL-17A-producing T helper (Th)-17 cells. CONCLUSIONS: Our findings suggest that inhibited NF-κB signaling and downregulation of IL-1ß expression in monocytes contributes to the immunomodulatory effects of laquinimod and that the impairment of Th17 polarization might mediate its disease-modifying activity in MS.


Asunto(s)
Interleucina-1beta/inmunología , Monocitos/efectos de los fármacos , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Quinolonas/uso terapéutico , Células Th17/inmunología , Adulto , Estudios Transversales , Femenino , Humanos , Interleucina-1beta/metabolismo , Activación de Linfocitos/efectos de los fármacos , Masculino , Persona de Mediana Edad , Monocitos/inmunología , Esclerosis Múltiple Recurrente-Remitente/inmunología , Transducción de Señal/efectos de los fármacos
12.
Nat Commun ; 12(1): 6837, 2021 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-34824213

RESUMEN

In the standard model of charge density wave (CDW) transitions, the displacement along a single phonon mode lowers the total electronic energy by creating a gap at the Fermi level, making the CDW a metal-insulator transition. Here, using scanning tunneling microscopy and spectroscopy and ab initio calculations, we show that VS2 realizes a CDW which stands out of this standard model. There is a full CDW gap residing in the unoccupied states of monolayer VS2. At the Fermi level, the CDW induces a topological metal-metal (Lifshitz) transition. Non-linear coupling of transverse and longitudinal phonons is essential for the formation of the CDW and the full gap above the Fermi level. Additionally, x-ray magnetic circular dichroism reveals the absence of net magnetization in this phase, pointing to coexisting charge and spin density waves in the ground state.

13.
BMC Health Serv Res ; 10: 77, 2010 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-20331904

RESUMEN

BACKGROUND: Chronic heart failure (CHF) is the leading cause of all hospitalisations and readmissions in older people, accounting for a large proportion of developed countries' national health care expenditure. CHF can severely affect people's quality of life by reducing their independence and ability to undertake certain activities of daily living, as well as affecting their psychosocial and economic capacity. This paper reports the findings of a systematic narrative review of qualitative studies concerning people's experience of living with CHF, aiming to develop a wide-ranging understanding of what is known about the patient experience. METHODS: We searched eight relevant electronic databases using the terms based on the diagnosis of 'chronic heart failure', 'heart failure' and 'congestive heart failure' and qualitative methods, with restrictions to the years 1990-May 2008. We also used snowballing, hand searching and the expert knowledge of the research team to ensure all relevant papers were included in the review. Of 65 papers collected less than half (n = 30) were found relevant for this review. These papers were subsequently summarised and entered into QSR NVivo7 for data management and analysis. RESULTS: The review has identified the most prominent impacts of CHF on a person's everyday life including social isolation, living in fear and losing a sense of control. It has also identified common strategies through which patients with CHF manage their illness such as sharing experiences and burdens with others and being flexible to changing circumstances. Finally, there are multiple factors that commonly impact on patients' self care and self-management in the disease trajectory including knowledge, understanding and health service encounters. These health service encounters encompass access, continuity and quality of care, co-morbid conditions, and personal relationships. CONCLUSIONS: The core and sub-concepts identified within this study provide health professionals, service providers, policy makers and educators with broad insights into common elements of people's experiences of CHF and potential options for improving their health and wellbeing. Future studies should focus on building a comprehensive picture of CHF through examination of differences between genders, and differences within age groups, socioeconomic groups and cultural groups.


Asunto(s)
Insuficiencia Cardíaca/psicología , Actividades Cotidianas , Adaptación Psicológica , Comorbilidad , Costo de Enfermedad , Familia , Miedo , Insuficiencia Cardíaca/terapia , Humanos , Relaciones Interpersonales , Investigación Cualitativa , Calidad de Vida , Autocuidado , Aislamiento Social
14.
Aust J Prim Health ; 16(1): 66-74, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21133301

RESUMEN

The increasing prevalence of chronic disease is a driver of health system reform in most economically advanced nations. A consistent theme within these reforms is building greater patient-centredness into the health care delivery. This study aims to develop an in-depth understanding of the experience of patients and family carers affected by chronic illness that will be the basis on which to propose policy and health system interventions that are patient-centred. Participants struggled with the ongoing tasks of balancing their lives with the increasing demands and intrusion of chronic illness. Their attempts to achieve a balance were seriously hampered by fragmented services, complexity in navigating health services, relationships with health professionals and others, and co-morbidity. Future policy directions include designing models of care and infrastructure that enable patients and their family carers to balance life and illness, and aligning patient-centred care not only within health services but also with community and social support services.


Asunto(s)
Cuidadores/psicología , Enfermedad Crónica/psicología , Atención Dirigida al Paciente/métodos , Calidad de Vida/psicología , Perfil de Impacto de Enfermedad , Anciano , Anciano de 80 o más Años , Territorio de la Capital Australiana , Diabetes Mellitus Tipo 2/psicología , Diabetes Mellitus Tipo 2/terapia , Femenino , Insuficiencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Necesidades , Nueva Gales del Sur , Atención Dirigida al Paciente/normas , Enfermedad Pulmonar Obstructiva Crónica , Investigación Cualitativa
15.
Nanoscale Adv ; 2(1): 377-383, 2020 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-36134011

RESUMEN

Owing to its simplicity and versatility, the successive ionic layer adsorption and reaction (SILAR) method is increasingly being employed to develop low-cost hetero-nanostructured sensitized oxide systems for solar energy conversion, such as solar cells and solar fuels schemes. Understanding the nature of the SILAR quantum dot (QD) nucleation and growth on an insulating oxide is then critical as it will determine the QD density and spatial distribution, as well as the optoelectronic properties of the QD/oxide interfaces (e.g. QD bandgap onset). Here, we demonstrate epitaxial nucleation of lead sulfide (PbS) QDs onto a planar rutile titanium dioxide (100) surface employing the SILAR method. The QDs nucleated by SILAR are crystalline structures characterized by a truncated pyramidal shape, with nucleation occurring preferentially along the rutile (010) and (001) crystal orientations. The PbS QD size distribution is constrained by lattice mismatch causing strain in the lead sulfide. These results highlight the potential of SILAR for the facile growth of high-quality epitaxial nanostructures in liquid phase, under ambient conditions and at room temperature.

16.
Stud Health Technol Inform ; 271: 271-276, 2020 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-32578573

RESUMEN

Publicly accessible databases with evidence-based information on drug dosages for children and adolescents are not available in Germany. In previous work a prototypical web-based online platform for pediatric dosing recommendation has been developed. Quality assured maintenance of such a database is a time consuming effort. Recent work has shown that it is possible to use routinely documented data for machine learning approaches in order to create models for future decision support tools. This work describes the development of a prototype for pediatric dosing recommendations on the basis of routine drug prescriptions. Since they are structured for daily clinical use, not for machine learning, they include a substantial proportion of narrative text that requires preprocessing with consideration of medical and pharmaceutical knowledge. Three different learning algorithms have been applied and compared. The genetic algorithm with backpropagation has achieved the highest accuracy in the predictions. Our study constitutes a first step towards pediatric dosing recommendations, but there are multiple additional steps to be taken before a routine use might be considered, such as an evaluation by experienced physicians.


Asunto(s)
Redes Neurales de la Computación , Adolescente , Algoritmos , Niño , Alemania , Humanos , Aprendizaje Automático
17.
Appl Clin Inform ; 11(2): 342-349, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32403139

RESUMEN

OBJECTIVES: This study aimed to describe an alternative approach for accessing electronic medical records (EMRs) from clinical decision support (CDS) functions based on Arden Syntax Medical Logic Modules, which can be paraphrased as "map the entire record." METHODS: Based on an experimental Arden Syntax processor, we implemented a method to transform patient data from a commercial patient data management system (PDMS) to tree-structured documents termed CDS EMRs. They are encoded in a specific XML format that can be directly transformed to Arden Syntax data types by a mapper natively integrated into the processor. The internal structure of a CDS EMR reflects the tabbed view of an EMR in the graphical user interface of the PDMS. RESULTS: The study resulted in an architecture that provides CDS EMRs in the form of a network service. The approach enables uniform data access from all Medical Logic Modules and requires no mapping parameters except a case number. Measurements within a CDS EMR can be addressed with straightforward path expressions. The approach is in routine use at a German university hospital for more than 2 years. CONCLUSION: This practical approach facilitates the use of CDS functions in the clinical routine at our local hospital. It is transferrable to standard-compliant Arden Syntax processors with moderate effort. Its comprehensibility can also facilitate teaching and development. Moreover, it may lower the entry barrier for the application of the Arden Syntax standard and could therefore promote its dissemination.


Asunto(s)
Registros Electrónicos de Salud , Lógica , Factores de Tiempo
18.
Science ; 369(6508): 1233-1238, 2020 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-32883866

RESUMEN

Young stars are surrounded by a circumstellar disk of gas and dust, within which planet formation can occur. Gravitational forces in multiple star systems can disrupt the disk. Theoretical models predict that if the disk is misaligned with the orbital plane of the stars, the disk should warp and break into precessing rings, a phenomenon known as disk tearing. We present observations of the triple-star system GW Orionis, finding evidence for disk tearing. Our images show an eccentric ring that is misaligned with the orbital planes and the outer disk. The ring casts shadows on a strongly warped intermediate region of the disk. If planets can form within the warped disk, disk tearing could provide a mechanism for forming wide-separation planets on oblique orbits.

19.
Stud Health Technol Inform ; 258: 36-40, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30942709

RESUMEN

The Arden Syntax is a standard for clinical decision support functions in the form of Medical Logic Modules (MLMs). While the data type system of the early versions was limited to flat lists, later versions introduced an object type, supporting complex data structures, even up to entire electronic medical records (EMRs). Such objects are static insofar as their structure cannot be modified at MLM runtime. University Hospital Erlangen uses an experimental Arden Syntax version termed PLAIN, which provides an integrated mapper for arbitrary data structures, including entire EMRs. To facilitate knowledge encoding and reduce MLM complexity, we searched for a way to complement patient records with precalculated data items. We modified the object data type in two ways. The first was to include a statement for the explicit creation of new attributes; the second was to implicitly create an attribute whenever a value is assigned to a previously non-existing attribute. As a proof of concept, we complemented the ventilation section of every accessed EMR with a patient-individual recommendation for the expiratory tidal volume. A means to extend the structure of an object at runtime provides several advantages. The precalculated data items need no longer be calculated by the MLMs themselves, which reduces complexity and facilitates code maintenance. This might be beneficial not only for clinical decision support, but also with respect to the use of Arden Syntax language constructs for phenotyping queries, as well as with respect to the frequently required preprocessing of EMR data.


Asunto(s)
Sistemas de Apoyo a Decisiones Clínicas , Registros Electrónicos de Salud , Fenotipo , Lenguajes de Programación , Humanos , Lenguaje
20.
Stud Health Technol Inform ; 258: 26-30, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30942707

RESUMEN

BACKGROUND: University Hospital Erlangen provides clinical decision support (CDS) functions in the intensive care setting, that are based on the Arden Syntax standard. These CDS functions generate extensive output, including patient data charts. In the course of the migration of our CDS platform we revised the charting tool because although the tool was generally perceived as useful, the clinical users reported several shortcomings. OBJECTIVE: During the migration of our CDS platform, we aimed at resolving the reported shortcomings and at developing a reusable and parameterizable charting tool, driven by best practices and requirements of local clinicians. METHODS: We conducted a requirements analysis with local clinicians and searched the literature for well-established guidelines for clinical charts. Using a charting library, we then implemented the tool based on the found criteria and provided it with a REST interface. RESULTS: The criteria catalog included 18 requirements, all of which were successfully implemented. The new charting tool fully replaced the previous implementation in clinical routine. It also provides a web interface that enables clinicians to configure charts without programming skills. CONCLUSION: The new charting tool combines local preferences with best practices for visualization of clinical time series data. With its REST interface and reusable design it can be easily integrated in existing CDS platforms.


Asunto(s)
Sistemas de Computación , Sistemas de Apoyo a Decisiones Clínicas , Cuidados Críticos , Registros Electrónicos de Salud , Hospitales Universitarios , Humanos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA