Employing surfactant-assisted hydrothermal synthesis to control CuGaO2 nanoparticle formation and improved carrier selectivity of perovskite solar cells

Delafossites like CuGaO2 have appeared as promising p-type semiconductor materials for opto-electronic applications mainly due to their high optical transparency and electrical conductivity. However, existing synthetic efforts usually result in particles with large diameter limiting their performance relevant to functional electronic applications. In this article, we report a novel surfactant-assisted hydrothermal synthesis method, which allows the development of ultrafine (~5 nm) monodispersed p-type CuGaO2 nanoparticles (NPs). We show that DMSO can be used as a ligand and dispersing solvent for stabilizing the CuGaO2 NPs. The resulting dispersion is used for the fabrication of dense, compact functional CuGaO2 electronic layer with properties relevant to advanced optoelectronic applications. As a proof of concept, the surfactant-assisted hydrothermal synthesized CuGaO2 is incorporated as a hole transporting layer (HTL) in the inverted p-i-n perovskite solar cell device architecture providing improved hole carrier selectivity and power conversion efficiency compared to conventional PEDOT:PSS HTL based perovskite solar cells

Functional neurodevelopment of working memory in early-onset schizophrenia: A longitudinal FMRI study

Schizophrenia, a debilitating disorder with typical manifestation of clinical symptoms in early adulthood, is characterized by cognitive impairments in executive processes such as in working memory (WM). However, there is a rare case of individuals with early-onset schizophrenia (EOS) starting before their 18th birthday, while WM and its neural substrates are still undergoing maturation. Using the WM n-back task with functional magnetic resonance imaging, we assessed the functional neurodevelopment of WM in adolescents with EOS and age- and gender-matched typically developing controls. Participants underwent neuroimaging in the same scanner twice, once at age 17 and at 21 (mean interscan interval = 4.3 years). General linear model analysis was performed to explore WM neurodevelopmental changes within and between groups. Psychopathological scores were entered in multiple regressions to detect brain regions whose longitudinal functional change was predicted by baseline symptoms in EOS. WM neurodevelopment was characterized by widespread functional reductions in frontotemporal and cingulate brain areas in patients and controls. No between-group differences were found in the trajectory of WM change. Baseline symptom scores predicted functional neurodevelopmental changes in frontal, cingulate, parietal, occipital, and cerebellar areas. The adolescent brain undergoes developmental processes such as synaptic pruning, which may underlie the refinement WM of network. Prefrontal and parietooccipital activity reduction is affected by clinical presentation of symptoms. Using longitudinal neuroimaging methods in a rare diagnostic sample of patients with EOS may help the advancement of neurodevelopmental biomarkers intended as pharmacological targets to tackle WM impairment

State anxiety influences P300 and P600 event-related potentials over parietal regions in the hollow-mask illusion experiment

The hollow-mask illusion is an optical illusion where a concave face is perceived as convex. It has been demonstrated that individuals with schizophrenia and anxiety are less susceptible to the illusion than controls. Previous research has shown that the P300 and P600 event-related potentials (ERPs) are affected in individuals with schizophrenia. Here, we examined whether individual differences in neuroticism and anxiety scores, traits that have been suggested to be risk factors for schizophrenia and anxiety disorders, affect ERPs of healthy participants while they view concave faces. Our results confirm that the participants were susceptible to the illusion, misperceiving concave faces as convex. We additionally demonstrate significant interactions of the concave condition with state anxiety in central and parietal electrodes for P300 and parietal areas for P600, but not with neuroticism and trait anxiety. The state anxiety interactions were driven by low-state anxiety participants showing lower amplitudes for concave faces compared to convex. The P300 and P600 amplitudes were smaller when a concave face activated a convex face memory representation, since the stimulus did not match the active representation. The opposite pattern was evident in high-state anxiety participants in regard to state anxiety interaction and the hollow-mask illusion, demonstrating larger P300 and P600 amplitudes to concave faces suggesting impaired late information processing in this group. This could be explained by impaired allocation of attentional resources in high-state anxiety leading to hyperarousal to concave faces that are unexpected mismatches to standard memory representations, as opposed to expected convex faces

Mediterranean Sea Literacy: When Ocean Literacy becomes region-specific

Ocean Literacy (OL) has been defined as an understanding of the ocean’s influence on people and their influence on the ocean. The OL movement was born in the US and its framework consisted of seven essential principles and 45 fundamental concepts; it is now largely accepted worldwide for use in both formal (schools and universities) and non-formal (research institutes, aquaria, museums, etc.) education settings. Based on this framework, marine scientists and educators developed the “Mediterranean Sea Literacy” (MSL) guide adapted to the specificities of the Mediterranean region, presented here. The MSL principles (7) and concepts (43), serving as guidance for research, education, informed decision-making, and improved citizens’ lifestyles, aim to contribute to environmental protection, conservation, and restoration of the Mediterranean Sea as well as to help to achieve a blue innovative and sustainable economy

Inverted Perovskite Photovoltaics Using Flame Spray Pyrolysis Solution Based CuAlO2/Cu−O Hole-Selective Contact

We present the functionalization process of a conductive and transparent CuAlO2/Cu-O hole-transporting layer (HTL). The CuAlO2/Cu-O powders were developed by flame spray pyrolysis and their stabilized dispersions were treated by sonication and centrifugation methods. We show that when the supernatant part of the treated CuAlO2/Cu-O dispersions is used for the development of CuAlO2/Cu-O HTLs the corresponding inverted perovskite-based solar cells show improved functionality and power conversion efficiency of up to 16.3% with negligible hysteresis effect

Nitrobenzene as additive to improve reproducibility and degradation resistance of highly efficient methylammonium-free inverted Perovskite solar cells

We show that the addition of 1% (v/v) nitrobenzene within the perovskite formulation can be used as a method to improve the power conversion efficiency and reliability performance of methylammonium-free (CsFA) inverted perovskite solar cells. The addition of nitrobenzene increased power conversion efficiency (PCE) owing to defect passivation and provided smoother films, resulting in hybrid perovskite solar cells (PVSCs) with a narrower PCE distribution. Moreover, the nitrobenzene additive methylammonium-free hybrid PVSCs exhibit a prolonged lifetime compared with additive-free PVSCs owing to enhanced air and moisture degradation resistance

Barriers to accessing biologic treatment for rheumatoid arthritis in Greece: The unseen impact of the fiscal crisis - The Health Outcomes Patient Environment (HOPE) study

The latest regulatory change in the distribution system of biologic disease-modifying, antirheumatic drugs limited their sale only through the designated pharmacies of the National Organization for Healthcare Services Provision (EOPYY) or the National Health System (NHS) hospitals, adding to the complexity of access to effective treatment for rheumatoid arthritis (RA) in Greece. The aim of this paper was to assess the barriers to access RA treatment, by recording patients', rheumatologists' and EOPYY pharmacists' experiences. One twenty-three patients, 12 rheumatologists and 27 pharmacists from Athens and other urban areas in Greece participated in the study. Three types of standardized questionnaires were used to elicit information from each group of respondents using the method of personal interview for patients and the method of postal survey for doctors and pharmacists. During the last year, 26 % of patients encountered problems in accessing their rheumatologist and 49 % of patients experienced difficulties in accessing their medication. Ninety-two percent of rheumatologists and 96 % of pharmacists confirmed that patients experience difficulties in accessing RA medication. The most commonly reported reasons for reduced access to medical treatment were travel difficulties and long distance from doctor's clinic, as well as delays in booking an appointment. The most frequently reported barriers to access pharmaceutical treatment were difficulties in the prescription process, distance from EOPYY pharmacies and medicine shortages in NHS hospitals. The study showed that RA patients are facing increased barriers to access timely and effective treatment. Redesign of the current system of distribution ensuring the operation of additional points of sale is deemed necessary. © 2013 Springer-Verlag Berlin Heidelberg

Low-Temperature Combustion Synthesis of a Spinel NiCo2O4 Hole Transport Layer for Perovskite Photovoltaics

The synthesis and characterization of low-temperature solution-processable monodispersed nickel cobaltite (NiCo 2 O 4 ) nanoparticles (NPs) via a combustion synthesis is reported using tartaric acid as fuel and the performance as a hole transport layer (HTL) for perovskite solar cells (PVSCs) is demonstrated. NiCo 2 O 4 is a p-type semiconductor consisting of environmentally friendly, abundant elements and higher conductivity compared to NiO. It is shown that the combustion synthesis of spinel NiCo 2 O 4 using tartaric acid as fuel can be used to control the NPs size and provide smooth, compact, and homogeneous functional HTLs processed by blade coating. Study of PVSCs with different NiCo 2 O 4 thickness as HTL reveals a difference on hole extraction efficiency, and for 15 nm, optimized thickness enhanced hole carrier collection is achieved. As a result, p-i-n structure of PVSCs with 15 nm NiCo 2 O 4 HTLs shows reliable performance and power conversion efficiency values in the range of 15.5% with negligible hysteresis