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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 322: 124773, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-39002469

RESUMEN

The transformation of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid bilayers from the gel (Lß') to the fluid (Lα) phase involves an intermediate ripple (Pß') phase forming a few degrees below the main transition temperature (Tm). While the exact cause of bilayer rippling is still debated, the presence of amphiphilic molecules, pH, and lipid bilayer architecture are all known to influence (pre)transition behavior. In particular, fatty acid chains interact with hydrophobic lipid tails, while the carboxylic groups simultaneously participate in proton transfer with interfacial water in the polar lipid region which is controlled by the pH of the surrounding aqueous medium. The molecular-level variations in the DPPC ripple phase in the presence of 2% palmitic acid (PA) were studied at pH levels 4.0, 7.3, and 9.1, where PA is fully protonated, partially protonated, or fully deprotonated. Bilayer thermotropic behavior was investigated by differential scanning calorimetry (DSC) and Fourier-transform infrared (FTIR) spectroscopy which agreed in their characterization of (pre)transition at pH of 9.1, but not at pH 4.0 and especially not at 7.3. Owing to the different insertion depths of protonated and deprotonated PA, along with the ability of protonated PA to undergo flip-flop in the bilayer, these two forms of PA show a different hydration pattern in the interfacial water layer. Finally, these results demonstrated the hitherto undiscovered potential of FTIR spectroscopy in the detection of the events occurring at the surface of lipid bilayers that obscure the low-cooperativity phase transition explored in this work.

2.
Nanomaterials (Basel) ; 14(13)2024 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-38998731

RESUMEN

Regular wave patterns were created by a 2 kV gallium ion on Si(111) monocrystals at incidence angles between 60° and 80° with respect to the surface normal. The characteristic wavelength and surface roughness of the structured surfaces were determined to be between 35-75 nm and 0.5-2.5 nm. The local slope distribution of the created periodic structures was also studied. These topography results were compared with the predictions of the Bradley-Harper model. The amorphised surface layers were investigated by a spectroscopic ellipsometer. According to the results, the amorphised thicknesses were changed in the range of 8 nm to 4 nm as a function of ion incidence angles. The reflectance of the structured surfaces was simulated using ellipsometric results and measured with a reflectometer. Based on the spectra, a controlled modification of reflectance within 45% and 50% can be achieved on Si(111) at 460 nm wavelength. According to the measured results, the characteristic sizes (periodicity and amplitude) and optical property of silicon can be fine-tuned by low-energy focused ion irradiation at the given interval of incidence angles.

3.
Sci Rep ; 14(1): 14413, 2024 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-38909108

RESUMEN

In this paper, an interleaved DC-DC step-up converter with improved characteristics based on a voltage multiplier rectifier is presented. The proposed converter is presented and analyzed for two different operating duty regions including operating region 1 (0 < D ≤ 0.5), and operating region 2 (0.5 ≤ D < 1). This converter can be used in various applications such as energy storage, electric vehicles, and renewable energy systems. This converter is composed of two stages: an interleaved boost stage and a voltage multiplier rectifier stage, which collectively forms its general structure. The interleaved boost stage is a type of two-phase boost converter that transforms the input DC voltage into a high-frequency AC square waveform. This waveform can be readily filtered using smaller capacitors. The square-shaped voltage waveform from the interleaved boost stage is rectified and converted to a high DC voltage by the Voltage Multiplier Rectifier (VMR) stage. The operating regions, the evaluation of the steady-state condition, the voltage gain of the proposed converter's parasitic and ideal models as well as its losses and efficiency analysis have been evaluated. The proposed converter has an efficiency of 97% at the output power of 150 W. The proposed converter is simulated to convert a voltage of 25-159.5 V and to validate the mathematical relationships and simulation results, a laboratory prototype has been developed. The simulation and experimental results show the precision of the performance of the proposed interleaved boost converter.

4.
Brain Res Bull ; 215: 111018, 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38908759

RESUMEN

PURPOSE: To explore the utility of high frequency oscillations (HFO) and long-range temporal correlations (LRTCs) in preoperative assessment of epilepsy. METHODS: MEG ripples were detected in 59 drug-resistant epilepsy patients, comprising 5 with parietal lobe epilepsy (PLE), 21 with frontal lobe epilepsy (FLE), 14 with lateral temporal lobe epilepsy (LTLE), and 19 with mesial temporal lobe epilepsy (MTLE) to identify the epileptogenic zone (EZ). The results were compared with clinical MEG reports and resection area. Subsequently, LRTCs were quantified at the source-level by detrended fluctuation analysis (DFA) and life/waiting -time at 5 bands for 90 cerebral cortex regions. The brain regions with larger DFA exponents and standardized life-waiting biomarkers were compared with the resection results. RESULTS: Compared to MEG sensor-level data, ripple sources were more frequently localized within the resection area. Moreover, source-level analysis revealed a higher proportion of DFA exponents and life-waiting biomarkers with relatively higher rankings, primarily distributed within the resection area (p<0.01). Moreover, these two LRCT indices across five distinct frequency bands correlated with EZ. CONCLUSION: HFO and source-level LRTCs are correlated with EZ. Integrating HFO and LRTCs may be an effective approach for presurgical evaluation of epilepsy.

5.
Artículo en Inglés | MEDLINE | ID: mdl-38942383

RESUMEN

This paper presents a novel approach to gap mapping in pulmonary vein isolation (PVI) for atrial fibrillation (AF) treatment, utilizing the real-time Ripple (RR) technique. Radiofrequency (RF) catheter ablation, particularly encircling PVI, is a common intervention for AF. Identifying left atrium-pulmonary vein conduction gaps is crucial for achieving PVI with minimal additional ablation if first-pass PVI is unsuccessful. However, identifying conduction gaps can be relatively challenging, often necessitating manual electrocardiogram reannotation due to the limitations of local activation time (LAT) maps. In the case of a 63-year-old patient with drug-resistant symptomatic persistent AF, the RR technique was utilized to identify conduction gaps during RF ablation. The technique involved pausing fast anatomical mapping (FAM), activating Ripple map (RM) feature on the CARTO 3 system and acquiring points with an ultrahigh-resolution mapping catheter. This approach revealed that the actual site of earliest activation differs from the LAT map indication, enabling successful PVI. The RM feature's capability to reflect actual excitation propagation without reliance on map annotations was crucial for precise conduction gap identification, overcoming inter-operator variability and inaccuracies of conventional methods. The RR technique not only facilitated real-time analysis during gap mapping but also significantly reduced the procedure time, minimizing potential complications. This case report highlights the efficacy of the RR technique in real-time gap mapping, demonstrating its value in cases where first-pass PVI is unsuccessful. The integration of this technique into PVI procedures can enhance both the accuracy and efficiency of catheter ablation for AF.

6.
Artículo en Inglés | MEDLINE | ID: mdl-38881174

RESUMEN

BACKGROUND: An accurate display of scar-related atrial tachycardia (ATs) is a key determinant of ablation success. The efficacy of ripple mapping (RM) in identifying the mechanism and critical isthmus of scar-related ATs during coherent mapping is unknown. METHODS: A total of 97 patients with complex ATs who underwent radiofrequency catheter ablation at our center between October 2018 and September 2022 were included. ATs was mapped using a multielectrode mapping catheter on the CARTO3v7 CONFIDENCE module. Coherent and RM were used to identify the reentrant circuit. RESULTS: The mechanisms of 128 ATs were analyzed retrospectively (84 anatomic-reentrant ATs and 44 non-anatomic reentrant ATs). The median AT cycle length was 264 ± 25ms. The correct diagnosis was achieved in 83 ATs (68%) using only coherent mapping. Through coherent mapping plus RM, 114 ATs (84.2%) were correctly diagnosed (68% vs. 89%, p = .019). In non-anatomical reentrant ATs, 81% of the diagnostic rate was achieved by reviewing both coherent and ripple mapping compared to reviewing coherent mapping alone (81% vs. 52%, p = .03). Reviewing coherent mapping and ripple mapping showed a higher diagnostic rate in patients who underwent cardiac surgery than those with Coherent mapping alone (64% vs. 88%, p = .04). CONCLUSION: Coherent mapping combined with RM was superior to coherent mapping alone in identifying the mechanism of scar-related ATs post-cardiac surgery and non-anatomic reentrant ATs.

7.
Phys Med Biol ; 69(14)2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38941999

RESUMEN

Objective.A simple, low-cost ripple filter consisting of multiple mesh sheets (mRiFi) was previously developed to reproducibly widen the Bragg peak of heavy-ion beams. To fabricate the mRiFi, the mRiFi parameters such as the wire material, wire diameter, wire spacing, and number of mesh sheets had to be determined. However, it was unclear how these parameters contribute to shifting and widening of the Bragg peak as well as to lateral spreading of the beam passing through the mRiFi. The purposes of this study were to clarify the contributions and to propose a recipe for fabricating a mRiFi with the desired performance values.Approach. We established an analytical calculation method to estimate shifting and widening of the Bragg peak and lateral spreading of heavy-ion beams passing through the mRiFi for given mRiFi parameter values. We also performed Monte Carlo simulations to validate the analytical calculation method. The recipe for fabricating the mRiFi with desired performances was established based on the analytical calculation method. Using the recipe, we fabricated the mRiFi for multi-ion therapy and evaluated its performance through demonstration experiments with helium-, carbon-, oxygen-, and neon-ion beams.Main results.The difference between the results of the Monte Carlo simulation and the analytical calculation was less than 0.4 mm for the peak shift, 0.15 mm for the peak width, and less than 0.11 mm for the lateral beam size which validated the analytical calculation method. The experimentally observed shift and width of the Bragg peak were consistent with the analytical calculations.Significance.We proposed a method to determine mRiFi parameters for fabricating a mRiFi with a desired performance, i.e. adequate widening of the Bragg peak with an acceptable peak shift and lateral beam spread. The proposed method allows anyone to fabricate a simple and low-cost mRiFi satisfying desired specifications.


Asunto(s)
Método de Montecarlo , Radioterapia de Iones Pesados/instrumentación , Filtración/instrumentación
8.
J Health Organ Manag ; 38(9): 195-215, 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38825598

RESUMEN

PURPOSE: To explore the mechanisms of the implementation strategy, "oilcloth sessions" and understand and explain the ripple effects of oilcloth sessions as a strategy to implement a new emergency department. DESIGN/METHODOLOGY/APPROACH: A qualitative design was used whereby data were collected using field notes from an ethnographic study of the oilcloth sessions and follow-up semi-structured interviews with staff, managers and key employees who participated in the oilcloth sessions. The data analysis was inspired by the realist evaluation approach of generative causality proposed by Pawson and Tilley. FINDINGS: The primary ripple effect was that the oilcloth sessions were used for different purposes than the proposed program theory, including being used as: (1) a stage, (2) a battlefield, (3) a space for imagination and (4) a strategic management tool influencing the implementation outcomes. The results bring essential knowledge that may help to explain why and how a well-defined implementation strategy has unplanned outcomes. ORIGINALITY/VALUE: Unintended outcomes of implementation strategies are an underexplored issue. This study may help implementation researchers rethink the activities required to reduce unintended negative outcomes or explore potential unplanned outcomes and, in this way, hinder or enhance outcomes, effectiveness and sustainability. Future studies within implementation research should incorporate attention to unintended outcomes to fully understand the impact of implementation strategies.


Asunto(s)
Investigación Cualitativa , Humanos , Entrevistas como Asunto , Servicio de Urgencia en Hospital , Evaluación de Programas y Proyectos de Salud
9.
ISA Trans ; 150: 338-358, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38763784

RESUMEN

This research proposes an Optimized Current chopping Control (CCC) approach for SRM drives. The goal is to implement a simple SRM drive that can effectively meet electric vehicle requirements, comprising minimized torque ripple to reduce vibrations and acoustic noises, maximized output torque to enhance vehicle acceleration, and improved efficiency, which contributes to extending the EV's battery life. Therefore, an optimization problem is formulated and solved offline, incorporating a CCC-based SRM drive model. The control variables for this optimization problem are the switching angles of the SRM. A multi-objective function is chosen to combine three performance indices: torque ripple, average torque, and efficiency. The Harris Hawks Optimization (HHO) method is utilized in this paper to solve the optimization problem and find the optimal switching angles based on the selected objective function. HHO demonstrates a strong search capability that can effectively handle the nonlinear magnetization characteristics of SRMs. Constraints on the switching angles are also included in the optimization problem to control the phase current's RMS value and power consumption. The optimized switching angles are applied to a current chopping control (CCC) strategy and an asymmetric half-bridge converter to implement the proposed HHO-based CCC drive. Moreover, to demonstrate the effectiveness of the proposed HHO-based CCC drive, a comparative analysis based on simulations and experimental measurements is presented against other CCC approaches for SRM drives, including modified particle swarm algorithm (MPSO)-based CCC drives and analytical-based CCC drives.

10.
Arts Health ; : 1-17, 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38700328

RESUMEN

BACKGROUND: The dance workforce plays a central role in delivering arts and health programmes yet there is little exploration of how programme delivery impacts dance artists in a professional or personal capacity. This study explored the experiences of dance artists delivering Dance On, which engages inactive older people 55yrs+. METHODS: Ripple Effects Mapping was used to explore the short- and long term experiences and practices of dance artists delivering a dance programme. FINDINGS: Two ripples were developed 1) Becoming a specialist 2) Connecting with communities. These ripples highlighted the strengths of the sustained nature of the programme and emphasised the need for ongoing support from employing organisations, communities, and dance artist peers. CONCLUSION: This study showcases the central role dance artists play in upholding the outcomes we observe in arts and health work - their role, expertise, and commitment to programmes should be further illuminated and supported through ongoing discourse about their practice.

11.
Biol Pharm Bull ; 47(5): 1021-1027, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38797694

RESUMEN

Learning and memory are affected by novel enriched environment, a condition where animals play and interact with a variety of toys and conspecifics. Exposure of animals to the novel enriched environments improves memory by altering neural plasticity during natural sleep, a process called memory consolidation. The hippocampus, a pivotal brain region for learning and memory, generates high-frequency oscillations called ripples during sleep, which is required for memory consolidation. Naturally occurring sleep shares characteristics in common with general anesthesia in terms of extracellular oscillations, guaranteeing anesthetized animals suitable to examine neural activity in a sleep-like state. However, it is poorly understood whether the preexposure of animals to the novel enriched environment modulates neural activity in the hippocampus under subsequent anesthesia. To ask this question, we allowed mice to freely explore the novel enriched environment or their standard environment, anesthetized them, and recorded local field potentials in the hippocampal CA1 area. We then compared the characteristics of hippocampal ripples between the two groups and found that the amplitude of ripples and the number of successive ripples were larger in the novel enriched environment group than in the standard environment group, suggesting that the afferent synaptic input from the CA3 area to the CA1 area was higher when the animals underwent the novel enriched environment. These results underscore the importance of prior experience that surpasses subsequent physical states from the neurophysiological point of view.


Asunto(s)
Hipocampo , Uretano , Animales , Uretano/farmacología , Masculino , Hipocampo/fisiología , Ratones , Ambiente , Ratones Endogámicos C57BL , Sueño/fisiología , Región CA1 Hipocampal/fisiología , Anestésicos Intravenosos/administración & dosificación , Consolidación de la Memoria/fisiología
12.
medRxiv ; 2024 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-38585730

RESUMEN

In medication-resistant epilepsy, the goal of epilepsy surgery is to make a patient seizure free with a resection/ablation that is as small as possible to minimize morbidity. The standard of care in planning the margins of epilepsy surgery involves electroclinical delineation of the seizure onset zone (SOZ) and incorporation of neuroimaging findings from MRI, PET, SPECT, and MEG modalities. Resecting cortical tissue generating high-frequency oscillations (HFOs) has been investigated as a more efficacious alternative to targeting the SOZ. In this study, we used a support vector machine (SVM), with four distinct fast ripple (FR: 350-600 Hz on oscillations, 200-600 Hz on spikes) metrics as factors. These metrics included the FR resection ratio (RR), a spatial FR network measure, and two temporal FR network measures. The SVM was trained by the value of these four factors with respect to the actual resection boundaries and actual seizure free labels of 18 patients with medically refractory focal epilepsy. Leave one out cross-validation of the trained SVM in this training set had an accuracy of 0.78. We next used a simulated iterative virtual resection targeting the FR sites that were highest rate and showed most temporal autonomy. The trained SVM utilized the four virtual FR metrics to predict virtual seizure freedom. In all but one of the nine patients seizure free after surgery, we found that the virtual resections sufficient for virtual seizure freedom were larger in volume (p<0.05). In nine patients who were not seizure free, a larger virtual resection made five virtually seizure free. We also examined 10 medically refractory focal epilepsy patients implanted with the responsive neurostimulator system (RNS) and virtually targeted the RNS stimulation contacts proximal to sites generating FR at highest rates to determine if the simulated value of the stimulated SOZ and stimulated FR metrics would trend toward those patients with a better seizure outcome. Our results suggest: 1) FR measures can accurately predict whether a resection, defined by the standard of care, will result in seizure freedom; 2) utilizing FR alone for planning an efficacious surgery can be associated with larger resections; 3) when FR metrics predict the standard of care resection will fail, amending the boundaries of the planned resection with certain FR generating sites may improve outcome; and 4) more work is required to determine if targeting RNS stimulation contact proximal to FR generating sites will improve seizure outcome.

13.
Neuron ; 112(12): 2045-2061.e10, 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38636524

RESUMEN

Cholecystokinin-expressing interneurons (CCKIs) are hypothesized to shape pyramidal cell-firing patterns and regulate network oscillations and related network state transitions. To directly probe their role in the CA1 region, we silenced their activity using optogenetic and chemogenetic tools in mice. Opto-tagged CCKIs revealed a heterogeneous population, and their optogenetic silencing triggered wide disinhibitory network changes affecting both pyramidal cells and other interneurons. CCKI silencing enhanced pyramidal cell burst firing and altered the temporal coding of place cells: theta phase precession was disrupted, whereas sequence reactivation was enhanced. Chemogenetic CCKI silencing did not alter the acquisition of spatial reference memories on the Morris water maze but enhanced the recall of contextual fear memories and enabled selective recall when similar environments were tested. This work suggests the key involvement of CCKIs in the control of place-cell temporal coding and the formation of contextual memories.


Asunto(s)
Colecistoquinina , Hipocampo , Interneuronas , Optogenética , Células Piramidales , Animales , Masculino , Ratones , Región CA1 Hipocampal/fisiología , Región CA1 Hipocampal/citología , Región CA1 Hipocampal/metabolismo , Colecistoquinina/metabolismo , Colecistoquinina/genética , Miedo/fisiología , Hipocampo/fisiología , Interneuronas/fisiología , Interneuronas/metabolismo , Aprendizaje/fisiología , Aprendizaje por Laberinto/fisiología , Memoria/fisiología , Recuerdo Mental/fisiología , Ratones Endogámicos C57BL , Ratones Transgénicos , Células Piramidales/fisiología , Células Piramidales/metabolismo , Ritmo Teta/fisiología
14.
Sleep ; 47(5)2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38452190

RESUMEN

STUDY OBJECTIVES: Sleep supports systems memory consolidation through the precise temporal coordination of specific oscillatory events during slow-wave sleep, i.e. the neocortical slow oscillations (SOs), thalamic spindles, and hippocampal ripples. Beneficial effects of sleep on memory are also observed in infants, although the contributing regions, especially hippocampus and frontal cortex, are immature. Here, we examined in rats the development of these oscillatory events and their coupling during early life. METHODS: EEG and hippocampal local field potentials were recorded during sleep in male rats at postnatal days (PD)26 and 32, roughly corresponding to early (1-2 years) and late (9-10 years) human childhood, and in a group of adult rats (14-18 weeks, corresponding to ~22-29 years in humans). RESULTS: SO and spindle amplitudes generally increased from PD26 to PD32. In parallel, frontocortical EEG spindles increased in density and frequency, while changes in hippocampal ripples remained nonsignificant. The proportion of SOs co-occurring with spindles also increased from PD26 to PD32. Whereas parietal cortical spindles were phase-locked to the depolarizing SO-upstate already at PD26, over frontal cortex SO-spindle phase-locking emerged not until PD32. Co-occurrence of hippocampal ripples with spindles was higher during childhood than in adult rats, but significant phase-locking of ripples to the excitable spindle troughs was observed only in adult rats. CONCLUSIONS: Results indicate a protracted development of synchronized thalamocortical processing specifically in frontocortical networks (i.e. frontal SO-spindle coupling). However, synchronization within thalamocortical networks generally precedes synchronization of thalamocortical with hippocampal processing as reflected by the delayed occurrence of spindle-ripple phase-coupling.


Asunto(s)
Electroencefalografía , Hipocampo , Animales , Ratas , Masculino , Hipocampo/fisiología , Tálamo/fisiología , Neocórtex/fisiología , Sueño/fisiología , Sueño de Onda Lenta/fisiología , Ondas Encefálicas/fisiología
16.
Sci Rep ; 14(1): 6448, 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38499574

RESUMEN

High performance and comfort are key features recommended in hybrid electric vehicle (HEV) design. In this paper, a new coordination strategy is proposed to solve the issue of undesired torque jerks and large power ripples noticed respectively during drive mode commutations and power sources switching. The proposed coordinated switching strategy uses stair-based transition function to perform drive mode commutations and power source switching's within defined transition periods fitting the transient dynamics of power sources and traction machines. The proposed technique is applied on a battery/ supercapacitor electric vehicle whose traction is ensured by two permanent magnet synchronous machines controlled using direct torque control and linked to HEV front and rear wheels. Simulation results highlight that the proposed coordinated switching strategy has a noteworthy positive impact on enhancing HEV transient performance as DC bus fluctuations were reduced to a narrow band of 6 V and transient torque ripples were almost suppressed.

17.
Cereb Cortex ; 34(3)2024 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-38494417

RESUMEN

During NREM sleep, hippocampal sharp-wave ripple (SWR) events are thought to stabilize memory traces for long-term storage in downstream neocortical structures. Within the neocortex, a set of distributed networks organized around retrosplenial cortex (RS-network) interact preferentially with the hippocampus purportedly to consolidate those traces. Transient bouts of slow oscillations and sleep spindles in this RS-network are often observed around SWRs, suggesting that these two activities are related and that their interplay possibly contributes to memory consolidation. To investigate how SWRs interact with the RS-network and spindles, we combined cortical wide-field voltage imaging, Electrocorticography, and hippocampal LFP recordings in anesthetized and sleeping mice. Here, we show that, during SWR, "up-states" and spindles reliably co-occur in a cortical subnetwork centered around the retrosplenial cortex. Furthermore, retrosplenial transient activations and spindles predict slow gamma oscillations in CA1 during SWRs. Together, our results suggest that retrosplenial-hippocampal interaction may be a critical pathway of information exchange between the cortex and hippocampus.


Asunto(s)
Neocórtex , Sueño de Onda Lenta , Ratones , Animales , Giro del Cíngulo , Hipocampo , Sueño
18.
Polymers (Basel) ; 16(5)2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38475403

RESUMEN

Y-shaped polymer brushes represent a special class of binary mixed polymer brushes, in which a combination of different homopolymers leads to unique phase behavior. While most theoretical and simulation studies use monodisperse models, experimental systems are always polydisperse. This discrepancy hampers linking theoretical and experimental results. In this theoretical study, we employed dissipative particle dynamics to study the influence of polydispersity on the phase behavior of Y-shaped brushes grafted to flat surfaces under good solvent conditions. Polydispersity was kept within experimentally achievable values and was modeled via Schulz-Zimm distribution. In total, 10 systems were considered, thus covering the phase behavior of monodisperse, partially polydisperse and fully polydisperse systems. Using such generic representation of real polymers, we observed a rippled structure and aggregates in monodisperse systems. In addition, polydisperse brushes formed a stable perforated layer not observed previously in monodisperse studies, and influenced the stability of the remaining phases. Although the perforated layer was experimentally observed under good solvent conditions and in the melt state, further confirmation of its presence in systems under good solvent conditions required mapping real polymers onto mesoscale models that reflected, for example, different polymer rigidity, and excluded volume effects or direct influence of the surface, just to mention a few parameters. Finally, in this work, we show that mesoscale modeling successfully describes polydisperse models, which opens the way for rapid exploring of complex systems such as polydisperse Y-shaped brushes in selective or bad solvents or under non-equilibrium conditions.

19.
Brain ; 147(7): 2496-2506, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38325327

RESUMEN

We evaluated whether spike ripples, the combination of epileptiform spikes and ripples, provide a reliable and improved biomarker for the epileptogenic zone compared with other leading interictal biomarkers in a multicentre, international study. We first validated an automated spike ripple detector on intracranial EEG recordings. We then applied this detector to subjects from four centres who subsequently underwent surgical resection with known 1-year outcomes. We evaluated the spike ripple rate in subjects cured after resection [International League Against Epilepsy Class 1 outcome (ILAE 1)] and those with persistent seizures (ILAE 2-6) across sites and recording types. We also evaluated available interictal biomarkers: spike, spike-gamma, wideband high frequency oscillation (HFO, 80-500 Hz), ripple (80-250 Hz) and fast ripple (250-500 Hz) rates using previously validated automated detectors. The proportion of resected events was computed and compared across subject outcomes and biomarkers. Overall, 109 subjects were included. Most spike ripples were removed in subjects with ILAE 1 outcome (P < 0.001), and this was qualitatively observed across all sites and for depth and subdural electrodes (P < 0.001 and P < 0.001, respectively). Among ILAE 1 subjects, the mean spike ripple rate was higher in the resected volume (0.66/min) than in the non-removed tissue (0.08/min, P < 0.001). A higher proportion of spike ripples were removed in subjects with ILAE 1 outcomes compared with ILAE 2-6 outcomes (P = 0.06). Among ILAE 1 subjects, the proportion of spike ripples removed was higher than the proportion of spikes (P < 0.001), spike-gamma (P < 0.001), wideband HFOs (P < 0.001), ripples (P = 0.009) and fast ripples (P = 0.009) removed. At the individual level, more subjects with ILAE 1 outcomes had the majority of spike ripples removed (79%, 38/48) than spikes (69%, P = 0.12), spike-gamma (69%, P = 0.12), wideband HFOs (63%, P = 0.03), ripples (45%, P = 0.01) or fast ripples (36%, P < 0.001) removed. Thus, in this large, multicentre cohort, when surgical resection was successful, the majority of spike ripples were removed. Furthermore, automatically detected spike ripples localize the epileptogenic tissue better than spikes, spike-gamma, wideband HFOs, ripples and fast ripples.


Asunto(s)
Electrocorticografía , Humanos , Masculino , Femenino , Adulto , Electrocorticografía/métodos , Adulto Joven , Adolescente , Electroencefalografía/métodos , Persona de Mediana Edad , Epilepsia/fisiopatología , Epilepsia/cirugía , Niño , Ondas Encefálicas/fisiología , Encéfalo/fisiopatología
20.
Front Public Health ; 12: 1249124, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38327570

RESUMEN

Older people living in their homes might experience growing loneliness, detachment from their social environment, and decreased functional ability. In this community case study, we report on a project we initiated to enhance the functional ability of older people by creating musical life reviews (MLR) with them. We connected seven of our music therapy graduates (MT) to older people living in the neighborhood across the street from campus. MTs were first trained to work by a protocol for creating MLRs with older people, developed by the authors of this article. They then worked with older people from the neighborhood for 10 one-on-one sessions, on personally tailored MLRs. MTs kept on meeting in weekly group supervision sessions, thus learning from each other- and forming a community of their own. Participants expressed their high satisfaction with the process and reported that their MLRs became increasingly important to them. Most of them were interested in taking their MLR one step ahead, and playing it to family and/or friends, and, as part of the process, planned a personal event to do this. Further, two big community events were initiated by participants and MTs. To conclude, we show how the community project enhanced the functional ability of those participating in it. We also point at possible challenges and recommendations for further implementation of the project.


Asunto(s)
Música , Humanos , Anciano , Soledad , Actividades Cotidianas
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