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1.
Nanoscale ; 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38695540

RESUMEN

In many applications of polyelectrolyte/surfactant (P/S) mixtures, it is difficult to fine-tune them after mixing the components without changing the sample composition, e.g. pH or the ionic strength. Here we report on a new approach where we use photoswitchable surfactants to enable drastic changes in both the bulk and interfacial properties. Poly(diallyldimethylammonium chloride) (PDADMAC) mixtures with three alkyl-arylazopyrazole butyl sulfonates (CnAAP) with -H, -butyl and -octyl tails are applied and E/Z photoisomerization of the surfactants is used to cause substantially different hydrophobic interactions between the surfactants and PDADMAC. These remotely controlled changes affect significantly the P/S binding and allows for tuning both the bulk and interfacial properties of PDADMAC/CnAAP mixtures through light irradiation. For that, we have fixed the surfactant concentrations at values where they exhibit pronounced surface tension changes upon E/Z photoisomerization with 365 nm UV light (Z) and 520 nm green (E) light and have varied the PDADMAC concentration. The electrophoretic mobility can be largely tuned by photoisomerisation of CnAAP surfactants and P/S aggregates, which can even exhibit a charge reversal from negative to positive values or vice versa. In addition, low colloidal stability at equimolar concentrations of PDADMAC with CnAAP surfactants in the E configuration lead to the formation of large aggregates in the bulk which can be broken up by irradiation with UV light when the surfactant's alkyl chain is short enough (C0AAP). Vibrational sum-frequency generation (SFG) spectroscopy reveals changes at the interface similar to the bulk, where the charging state at air-water interfaces can be modified with light irradiation. Using SFG spectroscopy, we interrogated the O-H stretching modes of interfacial H2O and provide qualitative information on surface charging that is complemented by neutron reflectometry, from which we resolved the surface excesses of PDADMAC and CnAAP at the air-water interface, independently.

2.
Langmuir ; 39(42): 14869-14879, 2023 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-37839073

RESUMEN

The interfacial structure and morphology of films spread from hyperbranched polyethylene imine/sodium dodecyl sulfate (PEI/SDS) aggregates at the air/water interface have been resolved for the first time with respect to polyelectrolyte charged density. A recently developed method to form efficient films from the dissociation of aggregates using a minimal quantity of materials is exploited as a step forward in enhancing understanding of the film properties with a view to their future use in technological applications. Interfacial techniques that resolve different time and length scales, namely, ellipsometry, Brewster angle microscopy, and neutron reflectometry, are used. Extended structures of both components are formed under a monolayer of the surfactant with bound polyelectrolytes upon film compression on subphases adjusted to pH 4 or 10, corresponding to high and low charge density of the polyelectrolyte, respectively. A rigid film is related to compact conformation of the PEI in the interfacial structure at pH 4, while it is observed that aggregates remain embedded in mobile films at pH 10. The ability to compact surfactants in the monolayer to the same extent as its maximum coverage in the absence of polyelectrolyte is distinct from the behavior observed for spread films involving linear polyelectrolytes, and intriguingly evidence points to the formation of extended structures over the full range of surface pressures. We conclude that the molecular architecture and charge density can be important parameters in controlling the structures and properties of spread polyelectrolyte/surfactant films, which holds relevance to a range of applications, such as those where PEI is used, including CO2 capture, electronic devices, and gene transfection.

3.
Nanoscale ; 15(26): 11141-11154, 2023 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-37338512

RESUMEN

We demonstrate control of the structure and morphology of polypeptide/surfactant films at the air/water interface as a function of the maximum compression ratio of the surface area, exploiting a recently developed film formation mechanism that requires minimal quantities of materials involving the dissociation of aggregates. The systems studied are poly(L-lysine) (PLL) or poly(L-arginine) (PLA) with sodium dodecyl sulfate (SDS), chosen because the surfactant (i) interacts more strongly with the latter polypeptide due to the formation of hydrogen bonds between the guanidinium group and its oxygen atoms, and (ii) induces bulk ß-sheet and α-helix conformations of the respective polypeptides. The working hypothesis is that such different interactions may be used to tune the film properties when compressed to form extended structures (ESs). Neutron reflectometry reveals that application of a high compression ratio (4.5 : 1) results in the nanoscale self-assembly of ESs containing up to two PLL-wrapped SDS bilayers. Brewster angle microscopy provides images of the PLL/SDS ESs as discrete regions on the micrometre scale while additional linear regions of PLA/SDS ESs mark macroscopic film folding. Ellipsometry demonstrates high stability of the different ESs formed. The collapse of PLL/SDS films upon compression to a very high ratio (10 : 1) is irreversible due to the formation of solid domains that remain embedded in the film upon expansion while that of PLA/SDS films is reversible. These findings demonstrate that differences in the side group of a polypeptide can have a major influence on controlling the film properties, marking a key step in the development of this new film formation mechanism for the design of biocompatible and/or biodegradable films with tailored properties for applications in tissue engineering, biosensors and antimicrobial coatings.

4.
Colloids Surf B Biointerfaces ; 227: 113341, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37210796

RESUMEN

The combination of in vitro models of biological membranes based on solid-supported lipid bilayers (SLBs) and of surface sensitive techniques, such as neutron reflectometry (NR), atomic force microscopy (AFM) and quartz crystal microbalance with dissipation monitoring (QCM-D), is well suited to provide quantitative information about molecular level interactions and lipid spatial distributions. In this work, cellular plasma membranes have been mimicked by designing complex SLB, containing phosphatidylinositol 4,5-bisphosphate (PtdIns4,5P2) lipids as well as incorporating synthetic lipo-peptides that simulate the cytoplasmic tails of transmembrane proteins. The QCM-D results revealed that the adsorption and fusion kinetics of PtdIns4,5P2 are highly dependent of Mg2+. Additionally, it was shown that increasing concentrations of PtdIns4,5P2 leads to the formation of SLBs with higher homogeneity. The presence of PtdIns4,5P2 clusters was visualized by AFM. NR provided important insights about the structural organization of the various components within the SLB, highlighting that the leaflet symmetry of these SLBs is broken by the presence of CD4-derived cargo peptides. Finally, we foresee our study to be a starting point for more sophisticated in vitro models of biological membranes with the incorporation of inositol phospholipids and synthetic endocytic motifs.


Asunto(s)
Fosfatidilinositoles , Tecnicas de Microbalanza del Cristal de Cuarzo , Fosfatidilinositoles/química , Tecnicas de Microbalanza del Cristal de Cuarzo/métodos , Microscopía de Fuerza Atómica , Membrana Dobles de Lípidos/química , Péptidos/química , Neutrones
5.
Langmuir ; 39(16): 5861-5871, 2023 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-37058525

RESUMEN

Smart interfaces that are responsive to external triggers such as light are of great interest for the development of responsive or adaptive materials and interfaces. Using alkyl-arylazopyrazole butyl sulfonate surfactants (alkyl-AAP) that can undergo E/Z photoisomerization when irradiated with green (E) and UV (Z) lights, we demonstrate through a combination of experiments and computer simulations that there can be surprisingly large changes in surface tension and in the molecular structure and order at air-water interfaces. Surface tensiometry, vibrational sum-frequency generation (SFG) spectroscopy, and neutron reflectometry (NR) are applied to the study of custom-synthesized AAP surfactants with octyl- and H-terminal groups at air-water interfaces as a function of their bulk concentration and E/Z configuration. Upon photoswitching, a drastic influence of the alkyl chain on both the surface activity and the responsiveness of interfacial surfactants is revealed from changes in the surface tension, γ, where the largest changes in γ are observed for octyl-AAP (Δγ ∼ 23 mN/m) in contrast to H-AAP with Δγ < 10 mN/m. Results from vibrational SFG spectroscopy and NR show that the interfacial composition and the molecular order of the surfactants drastically change with E/Z photoisomerization and surface coverage. Indeed, from analysis of the S-O (head group) and C-H vibrational bands (hydrophobic tail), a qualitative analysis of orientational and structural changes of interfacial AAP surfactants is provided. The experiments are complemented by resolution of thermodynamic parameters such as equilibrium constants from ultra-coarse-grained simulations, which also capture details like island formation and interaction parameters of interfacial molecules. Here, the interparticle interaction ("stickiness") and the interaction with the surface are adjusted, closely reflecting experimental conditions.

6.
J Colloid Interface Sci ; 629(Pt B): 785-795, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36195018

RESUMEN

HYPOTHESIS: Inositol phospholipids are well known to form clusters in the cytoplasmic leaflet of the plasma membrane that are responsible for the interaction and recruitment of proteins involved in key biological processes like endocytosis, ion channel activation and secondary messenger production. Although their phosphorylated inositol ring headgroup plays an important role in protein binding, its orientation with respect to the plane of the membrane and its lateral packing density has not been previously described experimentally. EXPERIMENTS: Here, we study phosphatidylinositol 4,5-bisphosphate (PIP2) planar model membranes in the form of Langmuir monolayers by surface pressure-area isotherms, Brewster angle microscopy and neutron reflectometry to elucidate the relation between lateral (in-plane) and perpendicular (out-of-plane) molecular organization of PIP2. FINDINGS: Different surface areas were explored through monolayer compression, allowing us to correlate the formation of transient PIP2 clusters with the change in orientation of the inositol-biphosphate headgroup, which was experimentally determined by neutron reflectometry.


Asunto(s)
Fosfatidilinositol 4,5-Difosfato , Fosfatidilinositoles , Fosfatidilinositoles/metabolismo , Fosfatidilinositol 4,5-Difosfato/química , Fosfatidilinositol 4,5-Difosfato/metabolismo , Fosfatos de Inositol/metabolismo , Membrana Celular/metabolismo , Unión Proteica
7.
Chem Commun (Camb) ; 58(76): 10687-10690, 2022 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-36065838

RESUMEN

Reversible control of the 3D structure of polyelectrolyte/surfactant films at the air/water interface is showcased. A recently discovered mechanism is exploited to form highly efficient, stable and biocompatible films by spreading aggregates composed of poly-L-lysine and sodium dodecyl sulfate on the surface of water. Reversible control of: (1) the surface monolayer coverage, (2) the switching on or off discrete extended structures, and (3) the extended structure coverage is demonstrated for the first time. The intricacy by which the film structures can be controlled is unprecedented and opens exciting potential to optimize film properties by chemical design for novel biomedical transfer applications.


Asunto(s)
Polilisina , Tensoactivos , Excipientes , Polielectrolitos , Dodecil Sulfato de Sodio/química , Propiedades de Superficie , Tensoactivos/química , Agua
8.
ACS Appl Mater Interfaces ; 14(3): 4656-4667, 2022 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-35029383

RESUMEN

Polyelectrolyte/surfactant (P/S) mixtures find many applications but are static in nature and cannot be reversibly reconfigured through the application of external stimuli. Using a new type of photoswitchable surfactants, we use light to trigger property changes in mixtures of an anionic polyelectrolyte with a cationic photoswitch such as electrophoretic mobilities, particle size, as well as their interfacial structure and their ability to stabilize aqueous foam. For that, we show that prevailing hydrophobic intermolecular interactions can be remotely controlled between poly(sodium styrene sulfonate) (PSS) and arylazopyrazole tetraethylammonium bromide (AAP-TB). Shifting the chemical potential for P/S binding with E/Z photoisomerization of the surfactants can reversibly disintegrate even large aggregates (>4 µm) and is accompanied by a substantial change in the net charging state of PSS/AAP-TB complexes, e.g., from negative to positive excess charges upon light irradiation. In addition to the drastic changes in the bulk solution, also at air-water interfaces, the interfacial stoichiometry and structure change drastically on the molecular level with E/Z photoisomerization, which can also drive the stability of aqueous foam on a macroscopic level.

9.
Sensors (Basel) ; 21(11)2021 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-34073142

RESUMEN

This study evaluates and compares the suitability for child-computer interaction (CCI, the branch within human-computer interaction focused on interactive computer systems for children) of two devices: a standard computer mouse and the ENLAZA interface, a head mouse that measures the user's head posture using an inertial sensor. A multidirectional pointing task was used to assess the motor performance and the users' ability to learn such a task. The evaluation was based on the interpretation of the metrics derived from Fitts' law. Ten children aged between 6 and 8 participated in this study. Participants performed a series of pre- and post-training tests for both input devices. After the experiments, data were analyzed and statistically compared. The results show that Fitts' law can be used to detect changes in the learning process and assess the level of psychomotor development (by comparing the performance of adults and children). In addition, meaningful differences between the fine motor control (hand) and the gross motor control (head) were found by comparing the results of the interaction using the two devices. These findings suggest that Fitts' law metrics offer a reliable and objective way of measuring the progress of physical training or therapy.


Asunto(s)
Movimiento , Desempeño Psicomotor , Computadores , Mano , Postura
10.
Sensors (Basel) ; 21(1)2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33401468

RESUMEN

This paper presents an efficient cyberphysical platform for the smart management of smart territories. It is efficient because it facilitates the implementation of data acquisition and data management methods, as well as data representation and dashboard configuration. The platform allows for the use of any type of data source, ranging from the measurements of a multi-functional IoT sensing devices to relational and non-relational databases. It is also smart because it incorporates a complete artificial intelligence suit for data analysis; it includes techniques for data classification, clustering, forecasting, optimization, visualization, etc. It is also compatible with the edge computing concept, allowing for the distribution of intelligence and the use of intelligent sensors. The concept of smart cities is evolving and adapting to new applications; the trend to create intelligent neighbourhoods, districts or territories is becoming increasingly popular, as opposed to the previous approach of managing an entire megacity. In this paper, the platform is presented, and its architecture and functionalities are described. Moreover, its operation has been validated in a case study where the bike renting service of Paris-Vélib' Métropole has been managed. This platform could enable smart territories to develop adapted knowledge management systems, adapt them to new requirements and to use multiple types of data, and execute efficient computational and artificial intelligence algorithms. The platform optimizes the decisions taken by human experts through explainable artificial intelligence models that obtain data from IoT sensors, databases, the Internet, etc. The global intelligence of the platform could potentially coordinate its decision-making processes with intelligent nodes installed in the edge, which would use the most advanced data processing techniques.

11.
Opt Express ; 28(3): 2699-2713, 2020 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-32121952

RESUMEN

ϕ-OTDR perturbation detection applications demand optimal precision of the perturbation location. Strategies for improving both signal-to-noise (SNR) and precision of the perturbation location in a laboratory environment may fail when applying to a very long fiber under test (FUT) in real-field environments. With this deployment, meaningful energy points representing the response of a certain perturbation can be located at random locations of the fiber other than the original location of the perturbation. These random locations are referred to as the ghost energy points that confuse the system to mistakenly consider the location of these points as the original perturbation location. We present in this paper a novel space-time scanning (ST-scan) method that segregates the ghost energy point locations from those of the real perturbation so that the original perturbation location estimation is improved.

12.
Sensors (Basel) ; 19(21)2019 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-31671921

RESUMEN

This paper presents a review of the techniques found in the literature that aim to achieve a robust heartbeat detection from fusing multi-modal physiological signals (e.g., electrocardiogram (ECG), blood pressure (BP), artificial blood pressure (ABP), stroke volume (SV), photoplethysmogram (PPG), electroencephalogram (EEG), electromyogram (EMG), and electrooculogram (EOG), among others). Techniques typically employ ECG, BP, and ABP, of which usage has been shown to obtain the best performance under challenging conditions. SV, PPG, EMG, EEG, and EOG signals can help increase performance when included within the fusion. Filtering, signal normalization, and resampling are common preprocessing steps. Delay correction between the heartbeats obtained over some of the physiological signals must also be considered, and signal-quality assessment to retain the best signal/s must be considered as well. Fusion is usually accomplished by exploiting regularities in the RR intervals; by selecting the most promising signal for the detection at every moment; by a voting process; or by performing simultaneous detection and fusion using Bayesian techniques, hidden Markov models, or neural networks. Based on the results of the review, guidelines to facilitate future comparison of the performance of the different proposals are given and promising future lines of research are pointed out.


Asunto(s)
Frecuencia Cardíaca/fisiología , Fisiología/métodos , Procesamiento de Señales Asistido por Computador , Algoritmos , Electrocardiografía , Humanos , Análisis de Ondículas
13.
Sensors (Basel) ; 19(21)2019 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-31653110

RESUMEN

In this work, a new clustering algorithm especially geared towards merging data arising from multiple sensors is presented. The algorithm, called PN-EAC, is based on the ensemble clustering paradigm and it introduces the novel concept of negative evidence. PN-EAC combines both positive evidence, to gather information about the elements that should be grouped together in the final partition, and negative evidence, which has information about the elements that should not be grouped together. The algorithm has been validated in the electrocardiographic domain for heartbeat clustering, extracting positive evidence from the heartbeat morphology and negative evidence from the distances between heartbeats. The best result obtained on the MIT-BIH Arrhythmia database yielded an error of 1.44%. In the St. Petersburg Institute of Cardiological Technics 12-Lead Arrhythmia Database database (INCARTDB), an error of 0.601% was obtained when using two electrocardiogram (ECG) leads. When increasing the number of leads to 4, 6, 8, 10 and 12, the algorithm obtains better results (statistically significant) than with the previous number of leads, reaching an error of 0.338%. To the best of our knowledge, this is the first clustering algorithm that is able to process simultaneously any number of ECG leads. Our results support the use of PN-EAC to combine different sources of information and the value of the negative evidence.


Asunto(s)
Algoritmos , Frecuencia Cardíaca/fisiología , Arritmias Cardíacas/patología , Análisis por Conglomerados , Bases de Datos Factuales , Electrocardiografía , Humanos
14.
Glob Chang Biol ; 24(10): 4505-4520, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29995346

RESUMEN

Fire is a major factor controlling global carbon (C) and nitrogen (N) cycling. While direct C and N losses caused by combustion have been comparably well established, important knowledge gaps remain on postfire N losses. Here, we quantified both direct C and N combustion losses as well as postfire gaseous losses (N2 O, NO and N2 ) and N leaching after a high-intensity experimental fire in an old shrubland in central Spain. Combustion losses of C and N were 9.4 Mg C/ha and 129 kg N/ha, respectively, representing 66% and 58% of initial aboveground vegetation and litter stocks. Moreover, fire strongly increased soil mineral N concentrations by several magnitudes to a maximum of 44 kg N/ha 2 months after the fire, with N largely originating from dead soil microbes. Postfire soil emissions increased from 5.4 to 10.1 kg N ha-1  year-1 for N2 , from 1.1 to 1.9 kg N ha-1  year-1 for NO and from 0.05 to 0.2 kg N ha-1  year-1 for N2 O. Maximal leaching losses occurred 2 months after peak soil mineral N concentrations, but remained with 0.1 kg N ha-1  year-1 of minor importance for the postfire N mass balance. 15 N stable isotope labelling revealed that 33% of the mineral N produced by fire was incorporated in stable soil N pools, while the remainder was lost. Overall, our work reveals significant postfire N losses dominated by emissions of N2 that need to be considered when assessing fire effects on ecosystem N cycling and mass balance. We propose indirect N gas emissions factors for the first postfire year, equalling to 7.7% (N2 -N), 2.7% (NO-N) and 5.0% (N2 O-N) of the direct fire combustion losses of the respective N gas species.


Asunto(s)
Incendios , Nitrógeno/análisis , Suelo/química , Ecosistema , Bosques , Gases , Región Mediterránea , Minerales/análisis , España
15.
Sci Rep ; 8(1): 8543, 2018 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-29867208

RESUMEN

Hypoglycosylation of α-dystroglycan (α-DG) resulting from deficiency of protein O-mannosyltransferase 1 (POMT1) may cause severe neuromuscular dystrophies with brain and eye anomalies, named dystroglycanopathies. The retinal involvement of these disorders motivated us to generate a conditional knockout (cKO) mouse experiencing a Pomt1 intragenic deletion (exons 3-4) during the development of photoreceptors, mediated by the Cre recombinase expressed from the cone-rod homeobox (Crx) gene promoter. In this mouse, retinal α-DG was unglycosylated and incapable of binding laminin. Retinal POMT1 deficiency caused significant impairments in both electroretinographic recordings and optokinetic reflex in Pomt1 cKO mice, and immunohistochemical analyses revealed the absence of ß-DG and of the α-DG-interacting protein, pikachurin, in the outer plexiform layer (OPL). At the ultrastructural level, noticeable alterations were observed in the ribbon synapses established between photoreceptors and bipolar cells. Therefore, O-mannosylation of α-DG in the retina carried out by POMT1 is crucial for the establishment of proper synapses at the OPL and transmission of visual information from cones and rods to their postsynaptic neurons.


Asunto(s)
Electrorretinografía , Manosiltransferasas , Células Fotorreceptoras Retinianas Conos , Sinapsis , Síndrome de Walker-Warburg , Animales , Distroglicanos/genética , Distroglicanos/metabolismo , Glicosilación , Manosiltransferasas/genética , Manosiltransferasas/metabolismo , Ratones , Ratones Noqueados , Células Fotorreceptoras Retinianas Conos/metabolismo , Células Fotorreceptoras Retinianas Conos/patología , Células Fotorreceptoras Retinianas Bastones/metabolismo , Células Fotorreceptoras Retinianas Bastones/patología , Sinapsis/genética , Sinapsis/metabolismo , Sinapsis/patología , Síndrome de Walker-Warburg/genética , Síndrome de Walker-Warburg/metabolismo , Síndrome de Walker-Warburg/patología
16.
PLoS One ; 13(3): e0194218, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29543853

RESUMEN

Light causes damage to the retina (phototoxicity) and decreases photoreceptor responses to light. The most harmful component of visible light is the blue wavelength (400-500 nm). Different filters have been tested, but so far all of them allow passing a lot of this wavelength (70%). The aim of this work has been to prove that a filter that removes 94% of the blue component may protect the function and morphology of the retina significantly. Three experimental groups were designed. The first group was unexposed to light, the second one was exposed and the third one was exposed and protected by a blue-blocking filter. Light damage was induced in young albino mice (p30) by exposing them to white light of high intensity (5,000 lux) continuously for 7 days. Short wavelength light filters were used for light protection. The blue component was removed (94%) from the light source by our filter. Electroretinographical recordings were performed before and after light damage. Changes in retinal structure were studied using immunohistochemistry, and TUNEL labeling. Also, cells in the outer nuclear layer were counted and compared among the three different groups. Functional visual responses were significantly more conserved in protected animals (with the blue-blocking filter) than in unprotected animals. Also, retinal structure was better kept and photoreceptor survival was greater in protected animals, these differences were significant in central areas of the retina. Still, functional and morphological responses were significantly lower in protected than in unexposed groups. In conclusion, this blue-blocking filter decreases significantly photoreceptor damage after exposure to high intensity light. Actually, our eyes are exposed for a very long time to high levels of blue light (screens, artificial light LED, neons…). The potential damage caused by blue light can be palliated.


Asunto(s)
Lesiones Oculares/prevención & control , Luz/efectos adversos , Traumatismos Experimentales por Radiación/prevención & control , Retina/efectos de la radiación , Degeneración Retiniana/prevención & control , Animales , Color , Electrorretinografía , Lesiones Oculares/diagnóstico , Lesiones Oculares/etiología , Etiquetado Corte-Fin in Situ , Ratones , Células Fotorreceptoras de Vertebrados/efectos de la radiación , Traumatismos Experimentales por Radiación/diagnóstico , Traumatismos Experimentales por Radiación/etiología , Retina/citología , Retina/lesiones , Degeneración Retiniana/etiología
19.
Metas enferm ; 20(5): 50-56, jun. 2017. tab
Artículo en Español | IBECS | ID: ibc-163760

RESUMEN

Objetivo: mostrar la evidencia científica sobre los resultados de la aplicación del Programa de Evaluación y Cuidado Individualizado del Desarrollo del Recién Nacido (NIDCAP) y sus potenciales beneficios clínicos en recién nacidos prematuros. Método: se llevó a cabo una revisión de la literatura, haciendo una búsqueda avanzada a través de PubMed, Cuiden, Scielo y Biblioteca Cochrane Plus, Google Académico y UpToDate. Dicha búsqueda se limitó a los idiomas inglés y español. El periodo de búsqueda fue el comprendido entre los años 2004 al 2016. Resultados: de los 281 documentos encontrados, fueron seleccionados 18. NIDCAP tiene el potencial de mejorar el desarrollo mental y psicomotor clínico. Los enfermeros, en comparación con el personal médico, tenían una actitud más positiva, mayor control conductual y una percepción de un mayor impacto positivo de NIDCAP en condiciones de UCIN. Las deficiencias en el diseño y métodos en los estudios revisados obstaculizan demandas de largo alcance sobre la eficacia del método. Los fundamentos científicos de los efectos del NIDCAP serían sustancialmente mejorados con estudios exhaustivos con seguimiento prolongado. Conclusiones: a pesar de los resultados esperanzadores en el desarrollo motor y cognitivo, y su valor de humanización, la evidencia científica sobre los efectos del NIDCAP es limitada al no demostrar que aporte mejorías clínicas significativas en el bebé prematuro. La evaluación de esta intervención integral, de alta complejidad, está cargada de una serie de problemas metodológicos. Las principales debilidades de los estudios están en los seguimientos a corto plazo y deficiencias metodológica, por lo que se necesitan estudios a largo plazo y con diseño centrado en objetivos concretos (AU)


Objective: to show the scientific evidence of the outcomes of the implementation of the Newborn Individualized Developmental Care and Assessment Program (NIDCAP) and its potential clinical benefits for pre-term newborns. Method: a literature review was conducted, through an advanced search in PubMed, Cuiden, Scielo and the Cochrane Plus Library, Academic Google and UpToDate. Said search was limited to English and Spanish. The search period included the years from 2004 to 2016. Results: eighteen (18) documents were selected of the 218 documents found. NIDCAP has the potential to improve mental and clinical psychomotor development. Compared with the medical staff, nurses had a more positive attitude, higher behavioural control, and a perception of a higher positive impact of NIDCAP in the NICU setting. The design and method deficiencies in the studies reviewed represent a barrier for long-term demands on the method efficacy. The scientific basis of NIDCAP effects would be significantly improved with comprehensive studies of prolonged follow-up. Conclusions: despite the hopeful outcomes on motor and cognitive development, and its humanization values, there is limited scientific evidence about NIDCAP effects, because it has not been demonstrated to offer significant clinical improvements in pre-term babies. The assessment of this comprehensive and high-complexity intervention is burdened by a series of methodological problems. The main weaknesses of the studies consist in their short-term follow-up and methodological problems. The main weaknesses of the studies consist in their short-term follow-up and methodological deficiencies; therefore, long-term studies are required, with a design focused on specific objectives (AU)


Asunto(s)
Humanos , Recién Nacido , Enfermedades del Prematuro/enfermería , Cuidado del Lactante/organización & administración , Recien Nacido Prematuro/crecimiento & desarrollo , Tamizaje Neonatal/enfermería , Enfermedades del Recién Nacido/enfermería , Planificación de Atención al Paciente/organización & administración , Enfermería Neonatal/tendencias , Evaluación de Eficacia-Efectividad de Intervenciones
20.
Sensors (Basel) ; 17(2)2017 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-28208687

RESUMEN

This paper presents a novel surveillance system aimed at the detection and classification of threats in the vicinity of a long gas pipeline. The sensing system is based on phase-sensitive optical time domain reflectometry (ϕ-OTDR) technology for signal acquisition and pattern recognition strategies for threat identification. The proposal incorporates contextual information at the feature level and applies a system combination strategy for pattern classification. The contextual information at the feature level is based on the tandem approach (using feature representations produced by discriminatively-trained multi-layer perceptrons) by employing feature vectors that spread different temporal contexts. The system combination strategy is based on a posterior combination of likelihoods computed from different pattern classification processes. The system operates in two different modes: (1) machine + activity identification, which recognizes the activity being carried out by a certain machine, and (2) threat detection, aimed at detecting threats no matter what the real activity being conducted is. In comparison with a previous system based on the same rigorous experimental setup, the results show that the system combination from the contextual feature information improves the results for each individual class in both operational modes, as well as the overall classification accuracy, with statistically-significant improvements.

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