Cortical microinfarcts in adults with Down syndrome assessed with 3T-MRI.

BACKGROUND: Cortical microinfarcts (CMI) were attributed to cerebrovascular disease and cerebral amyloid angiopathy (CAA). CAA is frequent in Down syndrome (DS) while hypertension is rare, yet no studies have assessed CMI in DS. METHODS: We included 195 adults with DS, 63 with symptomatic sporadic Alzheimer's disease (AD), and 106 controls with 3T magnetic resonance imaging. We assessed CMI prevalence in each group and CMI association with age, AD clinical continuum, vascular risk factors, vascular neuroimaging findings, amyloid/tau/neurodegeneration biomarkers, and cognition in DS. RESULTS: CMI prevalence was 11.8% in DS, 4.7% in controls, and 17.5% in sporadic AD. In DS, CMI increased in prevalence with age and the AD clinical continuum, was clustered in the parietal lobes, and was associated with lacunes and cortico-subcortical infarcts, but not hemorrhagic lesions. DISCUSSION: In DS, CMI are posteriorly distributed and related to ischemic but not hemorrhagic findings suggesting they might be associated with a specific ischemic CAA phenotype. HIGHLIGHTS: This is the first study to assess cortical microinfarcts (assessed with 3T magnetic resonance imaging) in adults with Down syndrome (DS). We studied the prevalence of cortical microinfarcts in DS and its relationship with age, the Alzheimer's disease (AD) clinical continuum, vascular risk factors, vascular neuroimaging findings, amyloid/tau/neurodegeneration biomarkers, and cognition. The prevalence of cortical microinfarcts was 11.8% in DS and increased with age and along the AD clinical continuum. Cortical microinfarcts were clustered in the parietal lobes, and were associated with lacunes and cortico-subcortical infarcts, but not hemorrhagic lesions. In DS, cortical microinfarcts are posteriorly distributed and related to ischemic but not hemorrhagic findings suggesting they might be associated with a specific ischemic phenotype of cerebral amyloid angiopathy.

Keeping prior anticoagulation treatment in the acute phase of ischaemic stroke: the REKOALA study.

INTRODUCTION: A consensus on the management of anticoagulated patients in the acute phase of ischaemic stroke has not yet been established. We aimed to evaluate clinical outcomes in such patients based on the continuation or discontinuation of anticoagulation. METHODS: Retrospective study of patients with acute ischaemic stroke and cardioembolic source receiving anticoagulant therapy is done. Patients were classified based on the continuation or discontinuation of anticoagulation at admission. Clinical outcomes, haemorrhagic and ischaemic events were assessed. Multivariate logistic regression analysis, propensity score matching (PSM) analysis and a sub-analysis of patients with severe ischaemic stroke at admission (NIHSS score ≥ 15) were performed. RESULTS: Anticoagulation was continued in 147 (78.8%) of 186 patients. Patients continuing anticoagulant had lower NIHSS (median 5 vs 18, p < 0.001). There were no differences in haemorrhagic or ischaemic events. In the multivariate analysis, good functional outcome at discharge was higher in the continuation group, OR (CI95%) 3.77 (1.2-11.2). PSM analysis adjusted for potential confounders such as NIHSS had higher rates of good functional outcomes at discharge (80% vs 36%, p = 0.004) and at 90 days (76% vs 44%, p = 0.042) in the continuation group. Patients with severe stroke in this group had lower 90-day mortality (34.6% vs 62.5%, p = 0.045) and higher rates of good clinical outcome at discharge (33.3% vs 8.3%, p = 0.032). No differences were observed in 90-day haemorrhagic or ischaemic events. CONCLUSION: Continuation of anticoagulation in patients with acute ischaemic stroke and cardioembolic source did not increase the risk of intracranial haemorrhage and may be associated with better functional outcomes.

Personalizing Nutrition Strategies: Bridging Research and Public Health.

In recent years, although life expectancy has increased significantly, non-communicable diseases (NCDs) continue to pose a significant threat to the health of the global population. Therefore, eating habits have been recognized as key modifiable factors that influence people's health and well-being. For this reason, it is interesting to study dietary patterns, since the human diet is a complex mixture of macronutrients, micronutrients, and bioactive compounds, and can modulate multiple physiological processes, including immune function, the metabolism, and inflammation. To ensure that the data we acquired were current and relevant, we searched primary and secondary sources, including scientific journals, bibliographic indexes, and databases in the last 15 years with the most relevant articles. After this search, we observed that all the recent research on NCDs suggests that diet is a critical factor in shaping an individual's health outcomes. Thus, cardiovascular, metabolic, mental, dental, and visual health depends largely on the intake, habits and patterns, and nutritional behaviors. A diet high in processed and refined foods, added sugars, and saturated fats can increase the risk of developing chronic diseases. On the other hand, a diet rich in whole, nutrient-dense foods, such as vegetables, fruits, nuts, legumes, and a high adherence to Mediterranean diet can improve health's people.

Synthesis of 2'-O-Methyl/2'-O-MOE-L-Nucleoside Derivatives and Their Applications: Preparation of G-Quadruplexes, Their Characterization, and Stability Studies.

Nucleosides and their analogues constitute an important family of molecules with potential antiviral and antiproliferative activity. The enantiomers of natural nucleosides, l-nucleoside derivatives, which have comparable biological activity but more favorable toxicological properties and greater metabolic stability than d-nucleosides, have emerged as a new class of therapeutic agents. Furthermore, l-nucleosides can be used as a building block to prepare l-oligonucleotides, which have identical physical properties in terms of solubility, hybridization kinetics, and duplex thermal stability as d-oligonucleotides but completely orthogonal in nature. Consequently, they are resistant to nuclease degradation, nontoxic, and immunologically passive, which are desirable properties for biomedical applications. Herein, we describe the synthesis of several 2'-O-methyl/2'-O-MOE-l-nucleoside pyrimidine derivatives and their incorporation into G-rich oligonucleotides. Finally, we evaluated the stability and resistance against nucleases of these new G-quadruplexes, demonstrating the potential of the l-nucleosides described in this work in providing enhanced nuclease resistance with a minimal impact in the nucleic acid structural properties.

Serie de casos sobre la mortalidad a 30 días tras trombectomía o fibrinólisis. El reto de la dispersión demográfica / Case series on 30-day mortality after thrombectomy or fibrinolysis. The challenge of demographic dispersion

Objetivo: el presente estudio tiene como propósito conocer la supervivencia de la trombectomía o fibrinólisis de pacientes con criterios de código ictus al cabo de 30 días. Además, se propone observar si la dispersión demográfica por ubicación del hospital tiene alguna influencia en dicha relación para el paciente. Método: estudio longitudinal, retrospectivo y observacional. Pacientes dentro del código ictus en la provincia de Ourense (Galicia). Los participantes son 153 pacientes con una media de edad de 76 ± 12 años, de los cuales 83 son mujeres, reclutados durante 17 meses. Las variables a considerar incluyeron la arteria afectada, intervención fibrinólisis/trombectomía, mortalidad al cabo de 30 días, aplicación de angiotomografía computarizada (angio-TC), cambios en la National Institutes Health Stroke Scale (NIHSS) y tiempos en el servicio de urgencias en tres hospitales de la provincia (Ourense, O Barco y Verín). Resultados: el 12,9% de los pacientes fallecieron en los 30 días siguientes a partir del evento. El 54,2% (84 pacientes) fueron sometidos a fibrinólisis; el 19,4%, a trombectomía, y el 26,0% (40 pacientes) fueron tratados mediante intervención combinada (fibrinólisis + trombectomía). El 13,1% de los pacientes bajo fibrinólisis alcanzaron el exitus letalis al cabo de 30 días. El análisis de regresión logística determinó que hacer una trombectomía disminuye la probabilidad de fallecimiento, pero no de forma significativa. Conclusiones: no se encontró una relación significativa entre la aplicación de un tratamiento concreto (trombectomía/fibrinólisis) o su combinación y la tasa de mortalidad de los pacientes al cabo de 30 días.(AU)

Purpose: this study aims to analyze the survival and mortality rate after 30 days in patients with stroke code and fibrinolysis/thrombectomy. In addition, it is proposed to observe whether the demographic dispersion by the hospital’s location has any impact on this relationship for the patient. Method: longitudinal, retrospective and observational study. Patients with stroke code in the province of Ourense, Galicia. Subjects are 153 patients with a mean age of 76±12 years (83 women), recruited over 17 months. The variables to consider included the affected artery, fibrinolysis/thrombectomy intervention, mortality after 30 days, application of computerized tomography angiography, changes in the NIHSS (National Institutes Stroke Scale) and times in the casualty department in three hospitals in the province (Ourense, O Barco and Verín). Results: 12.9% of patients died within 30 days of the event. At least 54.2% of patients (84) received fibrinolysis, 19.4% underwent thrombectomy and at least 40 patients (26.0%) underwent a combined intervention (fibrinolysis + thrombectomy). A total of 13.1% of patients with fibrinolysis reached exitus letalis after 30 days. Logistic analysis determined that performing a thrombectomy reduces the probability of death, but not significantly. Conclusions: no statistically significant relationship was detected between the application of a specific treatment (thrombectomy/fibrinolysis) or its combination with the mortality rate of patients after 30 days. Ourense hospital that is closest to the thrombectomy referral centres shows P<0.005 in regard to mortality.(AU)

Basal forebrain atrophy along the Alzheimer's disease continuum in adults with Down syndrome.

BACKGROUND: Basal forebrain (BF) degeneration occurs in Down syndrome (DS)-associated Alzheimer's disease (AD). However, the dynamics of BF atrophy with age and disease progression, its impact on cognition, and its relationship with AD biomarkers have not been studied in DS. METHODS: We included 234 adults with DS (150 asymptomatic, 38 prodromal AD, and 46 AD dementia) and 147 euploid controls. BF volumes were extracted from T-weighted magnetic resonance images using a stereotactic atlas in SPM12. We assessed BF volume changes with age and along the clinical AD continuum and their relationship to cognitive performance, cerebrospinal fluid (CSF) and plasma amyloid/tau/neurodegeneration biomarkers, and hippocampal volume. RESULTS: In DS, BF volumes decreased with age and along the clinical AD continuum and significantly correlated with amyloid, tau, and neurofilament light chain changes in CSF and plasma, hippocampal volume, and cognitive performance. DISCUSSION: BF atrophy is a potentially valuable neuroimaging biomarker of AD-related cholinergic neurodegeneration in DS.

Cross-sectional versus longitudinal cognitive assessments for the diagnosis of symptomatic Alzheimer's disease in adults with Down syndrome.

BACKGROUND: Down syndrome (DS) is a genetic form of Alzheimer's disease (AD). However, clinical diagnosis is difficult, and experts emphasize the need for detecting intra-individual cognitive decline. OBJECTIVE: To compare the performance of baseline and longitudinal neuropsychological assessments for the diagnosis of symptomatic AD in DS. METHODS: Longitudinal cohort study of adults with DS. Individuals were classified as asymptomatic, prodromal AD, or AD dementia. We performed receiver operating characteristic curve analyses to compare baseline and longitudinal changes of CAMCOG-DS and mCRT. RESULTS: We included 562 adults with DS. Baseline assessments showed good to excellent diagnostic performance for AD dementia (AUCs between 0.82 and 0.99) and prodromal AD, higher than the 1-year intra-individual cognitive decline (area under the ROC curve between 0.59 and 0.79 for AD dementia, lower for prodromal AD). Longer follow-ups increased the diagnostic performance of the intra-individual cognitive decline. DISCUSSION: Baseline cognitive assessment outperforms the 1-year intra-individual cognitive decline in adults with DS.

Association of biological sex with clinical outcomes and biomarkers of Alzheimer's disease in adults with Down syndrome.

The study of sex differences in Alzheimer's disease is increasingly recognized as a key priority in research and clinical development. People with Down syndrome represent the largest population with a genetic link to Alzheimer's disease (>90% in the 7th decade). Yet, sex differences in Alzheimer's disease manifestations have not been fully investigated in these individuals, who are key candidates for preventive clinical trials. In this double-centre, cross-sectional study of 628 adults with Down syndrome [46% female, 44.4 (34.6; 50.7) years], we compared Alzheimer's disease prevalence, as well as cognitive outcomes and AT(N) biomarkers across age and sex. Participants were recruited from a population-based health plan in Barcelona, Spain, and from a convenience sample recruited via services for people with intellectual disabilities in England and Scotland. They underwent assessment with the Cambridge Cognitive Examination for Older Adults with Down Syndrome, modified cued recall test and determinations of brain amyloidosis (CSF amyloid-ß 42 / 40 and amyloid-PET), tau pathology (CSF and plasma phosphorylated-tau181) and neurodegeneration biomarkers (CSF and plasma neurofilament light, total-tau, fluorodeoxyglucose-PET and MRI). We used within-group locally estimated scatterplot smoothing models to compare the trajectory of biomarker changes with age in females versus males, as well as by apolipoprotein ɛ4 carriership. Our work revealed similar prevalence, age at diagnosis and Cambridge Cognitive Examination for Older Adults with Down Syndrome scores by sex, but males showed lower modified cued recall test scores from age 45 compared with females. AT(N) biomarkers were comparable in males and females. When considering apolipoprotein ɛ4, female ɛ4 carriers showed a 3-year earlier age at diagnosis compared with female non-carriers (50.5 versus 53.2 years, P = 0.01). This difference was not seen in males (52.2 versus 52.5 years, P = 0.76). Our exploratory analyses considering sex, apolipoprotein ɛ4 and biomarkers showed that female ɛ4 carriers tended to exhibit lower CSF amyloid-ß 42/amyloid-ß 40 ratios and lower hippocampal volume compared with females without this allele, in line with the clinical difference. This work showed that biological sex did not influence clinical and biomarker profiles of Alzheimer's disease in adults with Down syndrome. Consideration of apolipoprotein ɛ4 haplotype, particularly in females, may be important for clinical research and clinical trials that consider this population. Accounting for, reporting and publishing sex-stratified data, even when no sex differences are found, is central to helping advance precision medicine.

The Psychological Science Accelerator's COVID-19 rapid-response dataset.

In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data.

Opposite pattern of transcranial direct current stimulation effects in middle-aged and older adults: Behavioral and neurophysiological evidence.

Introduction: Episodic memory (EM) exhibits an age-related decline, with overall increased impairment after the age of 65. The application of transcranial direct current stimulation (tDCS) to ameliorate cognitive decline in ageing has been extensively investigated, but its efficacy has been reported with mixed results. In this study, we aimed to assess whether age contributes to interindividual variability in tDCS efficacy. Methods: Thirty-eight healthy adults between 50 and 81 years old received anodal tDCS over the left prefrontal cortex during images encoding and then performed an EM recognition task while event-related potentials (ERPs) were recorded. Results: Our results showed an opposite pattern of effect between middle-aged (50-64 years) and older (65-81 years) adults. Specifically, performance in the recognition task after tDCS was enhanced in older adults and was worsened in middle-aged adults. Moreover, ERPs acquired during the recognition task showed that two EM components related to familiarity and post-retrieval monitoring, i.e., Early Frontal and Late Frontal Old-New effects, respectively, were significantly reduced in middle-aged adults after anodal tDCS. Discussion: These results support an age-dependent effect of prefrontal tDCS on EM processes and its underlying electrophysiological substrate, with opposing modulatory trajectories along the aging lifespan.

Impact of Graphene Monolayer on the Performance of Non-Conventional Silicon Heterojunction Solar Cells with MoOx Hole-Selective Contact.

In this work, a new design of transparent conductive electrode based on a graphene monolayer is evaluated. This hybrid electrode is incorporated into non-standard, high-efficiency crystalline silicon solar cells, where the conventional emitter is replaced by a MoOx selective contact. The device characterization reveals a clear electrical improvement when the graphene monolayer is placed as part of the electrode. The current-voltage characteristic of the solar cell with graphene shows an improved FF and Voc provided by the front electrode modification. Improved conductance values up to 5.5 mS are achieved for the graphene-based electrode, in comparison with 3 mS for bare ITO. In addition, the device efficiency improves by around 1.6% when graphene is incorporated on top. These results so far open the possibility of noticeably improving the contact technology of non-conventional photovoltaic technologies and further enhancing their performance.

Contextual factors predicting compliance behavior during the COVID-19 pandemic: A machine learning analysis on survey data from 16 countries.

Voluntary isolation is one of the most effective methods for individuals to help prevent the transmission of diseases such as COVID-19. Understanding why people leave their homes when advised not to do so and identifying what contextual factors predict this non-compliant behavior is essential for policymakers and public health officials. To provide insight on these factors, we collected data from 42,169 individuals across 16 countries. Participants responded to items inquiring about their socio-cultural environment, such as the adherence of fellow citizens, as well as their mental states, such as their level of loneliness and boredom. We trained random forest models to predict whether someone had left their home during a one week period during which they were asked to voluntarily isolate themselves. The analyses indicated that overall, an increase in the feeling of being caged leads to an increased probability of leaving home. In addition, an increased feeling of responsibility and an increased fear of getting infected decreased the probability of leaving home. The models predicted compliance behavior with between 54% and 91% accuracy within each country's sample. In addition, we modeled factors leading to risky behavior in the pandemic context. We observed an increased probability of visiting risky places as both the anticipated number of people and the importance of the activity increased. Conversely, the probability of visiting risky places increased as the perceived putative effectiveness of social distancing decreased. The variance explained in our models predicting risk ranged from < .01 to .54 by country. Together, our findings can inform behavioral interventions to increase adherence to lockdown recommendations in pandemic conditions.

IDEST: International Database of Emotional Short Texts.

We introduce a database (IDEST) of 250 short stories rated for valence, arousal, and comprehensibility in two languages. The texts, with a narrative structure telling a story in the first person and controlled for length, were originally written in six different languages (Finnish, French, German, Portuguese, Spanish, and Turkish), and rated for arousal, valence, and comprehensibility in the original language. The stories were translated into English, and the same ratings for the English translations were collected via an internet survey tool (N = 573). In addition to the rating data, we also report readability indexes for the original and English texts. The texts have been categorized into different story types based on their emotional arc. The texts score high on comprehensibility and represent a wide range of emotional valence and arousal levels. The comparative analysis of the ratings of the original texts and English translations showed that valence ratings were very similar across languages, whereas correlations between the two pairs of language versions for arousal and comprehensibility were modest. Comprehensibility ratings correlated with only some of the readability indexes. The database is published in osf.io/9tga3, and it is freely available for academic research.

A multi-lab test of the facial feedback hypothesis by the Many Smiles Collaboration.

Following theories of emotional embodiment, the facial feedback hypothesis suggests that individuals' subjective experiences of emotion are influenced by their facial expressions. However, evidence for this hypothesis has been mixed. We thus formed a global adversarial collaboration and carried out a preregistered, multicentre study designed to specify and test the conditions that should most reliably produce facial feedback effects. Data from n = 3,878 participants spanning 19 countries indicated that a facial mimicry and voluntary facial action task could both amplify and initiate feelings of happiness. However, evidence of facial feedback effects was less conclusive when facial feedback was manipulated unobtrusively via a pen-in-mouth task.

Neural correlates of episodic memory in adults with Down syndrome and Alzheimer's disease.

BACKGROUND: Adults with Down syndrome are at an ultra-high risk of developing early-onset Alzheimer's disease. Episodic memory deficits are one of the earliest signs of the disease, but their association with regional brain atrophy in the population with Down syndrome has not been explored. We aimed to investigate the neuroanatomical correlates of episodic memory in adults with Down syndrome and symptomatic Alzheimer's disease. METHODS: Single-center, cross-sectional study. A total of 139 adults with Down syndrome (85 asymptomatic and 54 with symptomatic Alzheimer's disease) were included in the study (mean age 43.6 ± 10.9 years, 46% female). Episodic memory was assessed using the modified Cued Recall Test. Immediate (trial 1 free immediate recall, trial 3 free immediate recall, total free immediate recall score, and total immediate score) and delayed scores (free delayed recall score and total delayed score) were examined. Cortical thickness from magnetic resonance imaging was determined with surface-based morphometry using the FreeSurfer 6.0 software package. The clusters of reduced cortical thickness were compared between symptomatic and asymptomatic participants to create a cortical atrophy map. Then, the correlation between cortical thickness and the modified Cued Recall Test subscores were separately assessed in symptomatic and asymptomatic subjects, controlling for age, sex, and severity of intellectual disability. RESULTS: Compared with asymptomatic participants, those with symptomatic Alzheimer's disease showed a pattern of cortical atrophy in posterior parieto-temporo-occipital cortices. In symptomatic subjects, trial 1 immediate free recall significantly correlated with cortical atrophy in lateral prefrontal regions. Trial 3 free immediate recall and total free immediate recall were associated with the most widespread cortical atrophy. Total immediate score was related to posterior cortical atrophy, including lateral parietal and temporal cortex, posterior cingulate cortex, precuneus, and medial temporal lobe areas. Delayed memory scores were associated with cortical atrophy in temporoparietal and medial temporal lobe regions. No significant relationships were observed between episodic memory measures and cortical atrophy in asymptomatic subjects. CONCLUSIONS: Different episodic memory measures were associated with cortical atrophy in specific brain regions in adults with Down syndrome and Alzheimer's disease. These results overlap with those described in sporadic Alzheimer's disease and further support the similarities between Down syndrome-associated Alzheimer's disease and that in the general population.

Longitudinal Clinical and Cognitive Changes Along the Alzheimer Disease Continuum in Down Syndrome.

Importance: Alzheimer disease (AD) is the main medical problem in adults with Down syndrome (DS). However, the associations of age, intellectual disability (ID), and clinical status with progression and longitudinal cognitive decline have not been established. Objective: To examine clinical progression along the AD continuum and its related cognitive decline and to explore the presence of practice effects and floor effects with repeated assessments. Design, Setting, and Participants: This is a single-center cohort study of adults (aged >18 years) with DS with different ID levels and at least 6 months of follow-up between November 2012 and December 2021. The data are from a population-based health plan designed to screen for AD in adults with DS in Catalonia, Spain. Individuals were classified as being asymptomatic, having prodromal AD, or having AD dementia. Exposures: Neurological and neuropsychological assessments. Main Outcomes and Measures: The main outcome was clinical change along the AD continuum. Cognitive decline was measured by the Cambridge Cognitive Examination for Older Adults With Down Syndrome and the modified Cued Recall Test. Results: A total of 632 adults with DS (mean [SD] age, 42.6 [11.4] years; 292 women [46.2%]) with 2847 evaluations (mean [SD] follow-up, 28.8 [18.7] months) were assessed. At baseline, there were 436 asymptomatic individuals, 69 patients with prodromal AD, and 127 with AD dementia. After 5 years of follow-up, 17.1% (95% CI, 12.5%-21.5%) of asymptomatic individuals progressed to symptomatic AD in an age-dependent manner (0.6% [95% CI, 0%-1.8%] for age <40 years; 21.1% [95% CI, 8.0%-32.5%] for age 40-44 years; 41.4% [95% CI, 23.1%-55.3%] for age 45-49 years; 57.5% [95% CI, 38.2%-70.8%] for age ≥50 years; P < .001), and 94.1% (95% CI, 84.6%-98.0%) of patients with prodromal AD progressed to dementia with no age dependency. Cognitive decline in the older individuals was most common among those who progressed to symptomatic AD and symptomatic individuals themselves. Importantly, individuals with mild and moderate ID had no differences in longitudinal cognitive decline despite having different performance at baseline. This study also found practice and floor effects, which obscured the assessment of longitudinal cognitive decline. Conclusions and Relevance: This study found an association between the development of symptomatic AD and a high risk of progressive cognitive decline among patients with DS. These results support the need for population health plans to screen for AD-related cognitive decline from the fourth decade of life and provide important longitudinal data to inform clinical trials in adults with DS to prevent AD.

Combined anodal transcranial direct current stimulation and behavioural naming treatment improves language performance in patients with post-stroke aphasia.

PRIMARY OBJECTIVE: During the last decade, studies using anodal transcranial Direct Current Stimulation (atDCS) have yielded promising results in patients with aphasia. The main aim of the present pilot study was to assess the effects of combined atDCS over the left posterior perisylvian region and behavioral naming training on the behavioral outcomes of language comprehension and production of patients with post-stroke aphasia. RESEARCH DESIGN: A 2 × 2 quasi-experimental design was conducted, optimal to compare changes after treatment in experimental versus control group. METHODS AND PROCEDURES: Ten patients with post-stroke aphasia were enrolled in this study: half received atDCS on the left posterior perisylvian region while they underwent a 2-week behavioral naming training. The other half received sham stimulation. The outcomes were measured using the abbreviated form of the Boston Diagnostic Aphasia Examination and analyzed using ANOVAs. MAIN OUTCOMES AND RESULTS: Both groups improved their performance in Oral comprehension, Narrative writing and Language Competence Index, but only those that received anodal tDCS presented better results in the Naming category after the treatment. CONCLUSIONS: AtDCS on the left posterior perisylvian area seems to be a promising tool for boosting the outcomes of behavioral naming therapy in patients with post-stroke aphasia.

Raytracing Modelling of Infrared Light Management Using Molybdenum Disulfide (MoS2) as a Back-Reflector Layer in a Silicon Heterojunction Solar Cell (SHJ).

The silicon heterojunction solar cell (SHJ) is considered the dominant state-of-the-art silicon solar cell technology due to its excellent passivation quality and high efficiency. However, SHJ's light management performance is limited by its narrow optical absorption in long-wave near-infrared (NIR) due to the front, and back tin-doped indium oxide (ITO) layer's free carrier absorption and reflection losses. Despite the light-trapping efficiency (LTE) schemes adopted by SHJ in terms of back surface texturing, the previous investigations highlighted the ITO layer as a reason for an essential long-wavelength light loss mechanism in SHJ solar cells. In this study, we propose the use of Molybdenum disulfide (MoS2) as a way of improving back-reflection in SHJ. The text presents simulations of the optical response in the backside of the SHJ applying the Monte-Carlo raytracing method with a web-based Sunsolve high-precision raytracing tool. The solar cells' electrical parameters were also resolved using the standard electrical equivalent circuit model provided by Sunsolve. The proposed structure geometry slightly improved the SHJ cell optical current density by ~0.37% (rel.), and hence efficiency (η) by about 0.4% (rel.). The SHJ cell efficiency improved by 21.68% after applying thinner back ITO of about 30 nm overlayed on ~1 nm MoS2. The efficiency improvement following the application of MoS2 is tentatively attributed to the increased NIR absorption in the silicon bulk due to the light constructive interface with the backside components, namely silver (Ag) and ITO. Study outcomes showed that improved SHJ efficiency could be further optimized by addressing front cell components, mainly front ITO and MoS2 contact engineering.

Sputtered Ultrathin TiO2 as Electron Transport Layer in Silicon Heterojunction Solar Cell Technology.

This work presents the implementation of ultrathin TiO2 films, deposited at room temperature by radio-frequency magnetron sputtering, as electron-selective contacts in silicon heterojunction solar cells. The effect of the working pressure on the properties of the TiO2 layers and its subsequent impact on the main parameters of the device are studied. The material characterization revealed an amorphous structure regardless of the working pressure; a rougher surface; and a blue shift in bandgap in the TiO2 layer deposited at the highest-pressure value of 0.89 Pa. When incorporated as part of the passivated full-area electron contact in silicon heterojunction solar cell, the chemical passivation provided by the intrinsic a-Si:H rapidly deteriorates upon the sputtering of the ultra-thin TiO2 films, although a short anneal is shown to restore much of the passivation lost. The deposition pressure and film thicknesses proved to be critical for the efficiency of the devices. The film thicknesses below 2 nm are necessary to reach open-circuit values above 660 mV, regardless of the deposition pressure. More so, the fill-factor showed a strong dependence on deposition pressure, with the best values obtained for the highest deposition pressure, which we correlated to the porosity of the films. Overall, these results show the potential to fabricate silicon solar cells with a simple implementation of electron-selective TiO2 contact deposited by magnetron sputtering. These results show the potential to fabricate silicon solar cells with a simple implementation of electron-selective TiO2 contact.

Sustainable Protocol for the Synthesis of 2',3'-Dideoxynucleoside and 2',3'-Didehydro-2',3'-dideoxynucleoside Derivatives.

An improved protocol for the transformation of ribonucleosides into 2',3'-dideoxynucleoside and 2',3'-didehydro-2',3'-dideoxynucleoside derivatives, including the anti-HIV drugs stavudine (d4T), zalcitabine (ddC) and didanosine (ddI), was established. The process involves radical deoxygenation of xanthate using environmentally friendly and low-cost reagents. Bromoethane or 3-bromopropanenitrile was the alkylating agent of choice to prepare the ribonucleoside 2',3'-bisxanthates. In the subsequent radical deoxygenation reaction, tris(trimethylsilyl)silane and 1,1'-azobis(cyclohexanecarbonitrile) were used to replace hazardous Bu3SnH and AIBN, respectively. In addition, TBAF was substituted for camphorsulfonic acid in the deprotection step of the 5'-O-silyl ether group, and an enzyme (adenosine deaminase) was used to transform 2',3'-dideoxyadenosine into 2',3'-dideoxyinosine (ddI) in excellent yield.