Charging of highly resistive granular metal films

We have used the Scanning Kelvin probe microscopy technique to monitor the charging process of highly resistive granular thin films. The sample is connected to two leads and is separated by an insulator layer from a gate electrode. When a gate voltage is applied, charges enter from the leads and rearrange across the sample. We find very slow processes with characteristic charging times exponentially distributed over a wide range of values, resulting in a logarithmic relaxation to equilibrium. After the gate voltage has been switched off, the system again relaxes logarithmically slowly to the new equilibrium. The results cannot be explained with diffusion models, but most of them can be understood with a hopping percolation model, in which the localization length is shorter than the typical site separation. The technique is very promising for the study of slow phenomena in highly resistive systems and will be able to estimate the conductance of these systems when direct macroscopic measurement techniques are not sensitive enough.Comment: 8 pages, 7 figure

New approaches on the study of the psychometric properties of the STAI

The main purpose of this study was to analyze the psychometric properties of the State-Trait Anxiety Inventory (STAI1). Previous studies have indicated different factor solutions. Nevertheless, there is still a lack of consensus about the best dimensional model of STAI scores.The sample consisted of 417 participants, composed of 387 (29.71% male) healthy participants (comparison group: M=35.5 years; SD=8.40), and 30 (36.66% male) patient (clinical group M=35.8 years; SD=12.94).The internal consistency evaluated through Ordinal Alpha was good, 0.98 and 0.94 in the non-clinical and the clinical samples, respectively. Test-retest reliability (two weeks) for Total Score was 0.81 for the non-clinical subsample, and 0.93 for the clinical subsample. Confirmatory factor analyses supported both a four factor model and bifactor model. Also, STAI scores showed statistically significant correlations with Burns Anxiety Inventory (Burns-A) scores. Furthermore, results showed statistically significant differences in the mean scores of the STAI between the clinical and the non-clinical subsamples.The psychometric properties of the STAI were adequate. The present study contributes to better understand the STAI structure through the comparison of new approaches in the study of the STAI internal structure. The results found may contribute in the efforts to improve the evaluation and identification of anxiety symptoms and disorders

Nanoscale Charge Density and Dynamics in Graphene Oxide

Graphene oxide (GO) is widely used as a component in thin film optoelectronic device structures for practical reasons because its electronic and optical properties can be controlled. Progress critically depends on elucidating the nanoscale electronic structure of GO. However, direct experimental access is challenging because of its disordered and nonconductive character. Here, we quantitatively mapped the nanoscopic charge distribution and charge dynamics of an individual GO sheet by using Kelvin probe force microscopy (KPFM). Charge domains are identified, presenting important charge interactions below distances of 20 nm. Charge dynamics with very long relaxation times of at least several hours and a logarithmic decay of the time correlation function are in excellent agreement with Monte Carlo simulations, revealing an universal hopping transport mechanism best described by Efros-Shklovskii''s law. © 2021 The Authors. Published by American Chemical Society

Schizotypy: The Way Ahead

Background: Empirical evidence suggests that schizotypy is a useful construct for analyzing and understanding psychotic disorders. However, several issues remain to be resolved. Method: This selective, critical review, addresses some questions and limitations, and discusses future directions of work. Results: First, we present a conceptual outline and discuss the evidence from translational and interdisciplinary studies on schizotypy. Next, we examine and discuss newer analytical and methodological approaches, including network and machine learning approaches. We also discuss newer psychometric identification approaches, such as those using biobehavioral and ambulatory assessment. Next, we review recent cross-cultural studies in schizotypy research. Finally, we identify new challenges and directions and draw conclusions. Conclusions: This selective, critical review suggests that new methods can contribute to the construction of a solid scientific model of schizotypy as a risk construct. // Esquizotipia: el Camino a Seguir. Antecedentes: la evidencia empírica ha demostrado que la esquizotipia es un constructo útil para analizar y comprender los trastornos psicóticos. Sin embargo, todavía quedan por resolver varias cuestiones. Método: en esta revisión selectiva y crítica se abordan algunas limitaciones, se discuten interrogantes y se comentan direcciones futuras de trabajo. Resultados: en primer lugar, se presenta una delimitación conceptual y se comenta la evidencia acumulada en diferentes estudios y niveles de análisis en el campo de la esquizotipia. A continuación, se examinan nuevos modelos psicopatológicos, como el modelo de red, y se presentan las diferentes herramientas desarrolladas y validadas para su evaluación. Seguidamente, se abordan algunas inquietudes metodológicas de fondo y se presentan nuevas técnicas y procedimientos psicométricos, como la evaluación ambulatoria y bioconductual. También se analizan algunos de los problemas inherentes en la investigación entre países y culturas. Finalmente, se establecen las conclusiones y se abordan nuevos desafíos y direcciones futuras de investigación. Conclusiones: esta revisión selectiva y crítica plantea que es necesario continuar trabajando en la construcción de un modelo científico sólido y refutable e incorporar nuevas pruebas científicas en el campo de la esquizotipia

The association between cognitive impairment and functional outcome in hospitalised older patients: a systematic review and meta-analysis

BACKGROUND: in hospitalised older adults, cognitive impairments are common and may be associated with functional outcomes. Our aim was to systematically review this association. METHOD: we systematically searched MEDLINE, CINAHL, AMED and PsycINFO from inception to April 2016. Non-English language studies were filtered out at search stage. All types of studies were considered for inclusion except reviews, conference abstracts, dissertations and case studies. Population: community-dwelling or institutionalised older adults aged 65 years or more, who are acutely hospitalised and have information on history of dementia and/or cognitive scores on admission. Setting: acute hospital (excluding critical care and subacute or intermediate care). Outcome of interest: change in a measure of physical function or disability between pre-admission or admission, and discharge or post-discharge. This review was registered on PROSPERO (CRD42016035978). RESULTS: the search returned 5,988 unique articles, of which 34 met inclusion criteria. All studies were observational, with 30 prospective and 4 retrospective from 14 countries, recruiting from general medicine (n = 11), geriatric medicine (n = 11) and mixed (n = 12) wards. Twenty-six studies (54,637 participants) were suitable for the quantitative synthesis. The meta-analysis suggested that cognitive impairment was associated with functional decline in hospitalised older adults (risk ratio (RR): 1.64; 95% confidence interval (CI): 1.45–1.86; P < 0.01). Results were similar in subanalyses focusing on diagnosis of dementia (RR: 1.36; 95% CI: 1.05–1.76; P = 0.02; n= 2,248) or delirium (RR: 1.55; 95% CI: 1.31–1.83; P < 0.01; n= 1,677). CONCLUSION: cognitive impairments seem associated with functional decline in hospitalised older people. Causality cannot be inferred, and limitations include low quality of studies and possible confounding

Sart and individual trial mistake thresholds: Predictive model for mobility decline

The Sustained Attention to Response Task (SART) has been used to measure neurocognitive functions in older adults. However, simplified average features of this complex dataset may result in loss of primary information and fail to express associations between test performance and clinically meaningful outcomes. Here, we describe a new method to visualise individual trial (raw) information obtained from the SART test, vis-a-vis age, and groups based on mobility status in a large population-based study of ageing in Ireland. A thresholding method, based on the individual trial number of mistakes, was employed to better visualise poorer SART performances, and was statistically validated with binary logistic regression models to predict mobility and cognitive decline after 4 years. Raw SART data were available for 4864 participants aged 50 years and over at baseline. The novel visualisation-derived feature bad performance, indicating the number of SART trials with at least 4 mistakes, was the most significant predictor of mobility decline expressed by the transition from Timed Up-and-Go (TUG) &lt; 12 to TUG &gt;= 12 s (OR = 1.29; 95% CI 1.14-1.46; p &lt; 0.001), and the only significant predictor of new falls (OR = 1.11; 95% CI 1.03-1.21; p = 0.011), in models adjusted for multiple covariates. However, no SART-related variables resulted significant for the risk of cognitive decline, expressed by a decrease of &gt;= 2 points in the Mini-Mental State Examination (MMSE) score. This novel multimodal visualisation could help clinicians easily develop clinical hypotheses. A threshold approach to the evaluation of SART performance in older adults may better identify subjects at higher risk of future mobility decline

Comprehensive geriatric assessment and clinical outcomes of frail older adults with diffuse large B-cell lymphoma: a metanalysis

Introduction. Comprehensive geriatric assessment (CGA) is used to personalize cancer treatments in frail older adults. However, its utility to guide treatments in frail older patients with diffuse large B-cell lymphoma (DLBCL) is not well known. We performed a meta-analysis of evidence published in this area.  Material and methods. We searched PubMed and Google Scholar for studies published between January 2000 and January 2023 that included patients aged ≥ 65 years with a diagnosis of DLBCL who underwent CGA before treatment (CGA-modulated studies) and who did not (non-CGA-modulated studies). We evaluated clinical outcomes in frail/unfit patients in terms of complete response (CR), incidence of grade ≥ 3 toxicity, and 2-year overall survival (OS) in both types of studies.  Results. Fifteen studies [8 CGA-modulated (n = 733, median age 76, 54% male, 52% frail/unfit) and 7 non-CGA-modulated (n = 2447, median age 76, 52% male, 32% frail/unfit)] were included. In the CGA-modulated studies, the CR proportion of frail/unfit patients was 34% (95% CI 23–46%) vs. 28% (95% CI 19–38%) in the non-CGA-modulated studies (p = 0.436). Grade 3–4 hematological toxicity in frail/unfit patients was 26% (95% CI 5–55%) vs. 36% (95% CI 13–63%) (p = 0.583), respectively. Two-year OS of frail/unfit patients was 52% (95% CI 38–66%) vs. 27% (95% CI 19–36%) (p = 0.003), respectively.  Conclusions. Although the proportion of frail/unfit patients was lower in non-CGA-modulated studies, CGA-modulated studies reported higher OS. CGA could be useful to guide the treatment plan in older patients with DLBCL. Randomized clinical trials with standardized CGA instruments are necessary to confirm these findings

Quantum and classical localisation, the spin quantum Hall effect and generalisations

We consider network models for localisation problems belonging to symmetry class C. This symmetry class arises in a description of the dynamics of quasiparticles for disordered spin-singlet superconductors which have a Bogoliubov - de Gennes Hamiltonian that is invariant under spin rotations but not under time-reversal. Our models include but also generalise the one studied previously in the context of the spin quantum Hall effect. For these systems we express the disorder-averaged conductance and density of states in terms of sums over certain classical random walks, which are self-avoiding and have attractive interactions. A transition between localised and extended phases of the quantum system maps in this way to a similar transition for the classical walks. In the case of the spin quantum Hall effect, the classical walks are the hulls of percolation clusters, and our approach provides an alternative derivation of a mapping first established by Gruzberg, Read and Ludwig, Phys. Rev. Lett. 82, 4254 (1999).Comment: 11 pages, 5 figure

Statistical properties of two-particle transmission at Anderson transition

The ensemble of $L \times L$ power-law random banded matrices, where the random hopping $H_{i,j}$ decays as a power-law $(b/| i-j |)^a$, is known to present an Anderson localization transition at $a=1$, where one-particle eigenfunctions are multifractal. Here we study numerically, at this critical point, the statistical properties of the transmission $T_2$ for two distinguishable particles, two bosons or two fermions. We find that the statistics of $T_2$ is multifractal, i.e. the probability to have $T_2(L) \sim 1/L^{\kappa}$ behaves as $L^{\Phi_2(\kappa)}$, where the multifractal spectrum $\Phi_2(\kappa)$ for fermions is different from the common multifractal spectrum concerning distinguishable particles and bosons. However in the three cases, the typical transmission $T_2^{typ}(L)$ is governed by the same exponent $\kappa_2^{typ}$, which is much smaller than the naive expectation $2\kappa_1^{typ}$, where $\kappa_1^{typ}$ is the typical exponent of the one-particle transmission $T_1(L)$.Comment: 9 pages, 4 figure