Bilayer and Trilayer C3N/Blue-Phosphorene Heterostructures as Potential Anode Materials for Potassium-Ion Batteries.

Two-dimensional (2D) van der Waals heterostructures outperform conventional anode materials for postlithium-ion batteries in terms of mechanical, thermal, and electrochemical properties. This study systemically investigates the performance of bilayer and trilayer C3N/blue phosphorene (C3N/BlueP) heterostructures as anode materials for potassium-ion batteries (KIBs) using first-principles density functional theory calculations. This study reveals that the adsorption and diffusion of K ions on bilayer and trilayer C3N/BlueP heterostructures are markedly superior to those of their monolayer counterparts. A bilayer heterostructure (C3N/BlueP) effectively reduces the bandgap of the BlueP monolayer (1.98 eV) to 0.02 eV, whereas trilayer heterostructures (bilayer-C3N/BlueP and C3N/bilayer-BlueP) exhibit metallic behavior with no bandgap. Additionally, the theoretical capacity of the bilayer and trilayer heterostructures ranges from 636.7 to 755.5 mA h g-1, considerably higher than the theoretical capacity of other prospective 2D heterostructures for KIBs investigated in the literature. This study also shows that the heterostructures exhibit K-ion diffusion barriers as low as 0.042 eV, ensuring the relatively fast diffusion of K ions.

Assessment of tear amount in subjects under the effect of (inhaled) cocaine.

The topic of ophthalmic use of cocaine in clinical practice has a long history; nevertheless, the possible influence and pathways of action of inhaled cocaine in the human eye remain unknown. This study evaluates the effect of snorted cocaine in the eye tear of 22 occasional cocaine users using the Schirmer Test I (ST1). The tear amount without the subjects being under the effect of cocaine was (mean +/- standard deviation) 22.50 +/- 12.85 mm ranging from 5-55 mm. Under the effect of cocaine, 17 in 22 eyes had a decrease in the tear amount, averaging 16.52 +/- 10.13 mm ranging from 1-38 mm, representing a statistical significant decrease (paired t-test, one-tailed p = 0.0024) of about 27% between the previous conditions. The large majority of the subjects under the effect of cocaine present a decrease in ST1 determining a global statistical significant decrease in ST1. That suggests a relationship between snorted cocaine and a reduction in tear amount. The identification of the tear cocaine effect and the pathway of action cannot be overlooked in the research for a comprehensive characterization of inhaled cocaine action in the central and peripheral nervous system.

Norms for the developmental eye movement test for Portuguese children.

PURPOSE: This work aims to define contemporary scores for the Developmental Eye Movement Test (DEM) for native Portuguese-speaking children (PT) and to compare these scores with three other published scores: the original norms, published in 1987 for American English-speaking children (U.S.) and two other scores published in 1995 (SP1) and 2003 (SP2) for Spanish-speaking children. METHODS: A standard DEM test was administered to 695 young students ranging in age from 6 to 13 years from the region of Braga, Portugal. The mean PT scores for vertical time and adjusted horizontal time as well as the corresponding errors and ratio were calculated according to age and grade, and these results were compared with those from other studies. In addition, the clinical response types (age and grade) were obtained based on mean PT scores. RESULTS: For several ages/grades, the scores obtained in this study were significantly different from the scores reported in other studies. A global qualitative analysis showed that PT made fewer errors and had similar ratios when compared with U.S. and SP2. However, PT were generally slower in vertical time and adjusted horizontal time in the younger age groups. When comparing PT and SP1, a higher ratio for SP1 was determined in all ages. The clinical response types signified below-normal performance scores for ages 6 to 9 and grades 1 to 5. CONCLUSIONS: The unusually large number of oculomotor and/or automaticity problems found in this normal PT population using a test based on U.S. norms highlights the need for PT-specific guidelines. It appears that DEM scores may be affected by differences in language, educational systems, and/or cultural systems. Therefore, clinicians should be aware of these findings when using the DEM test on children in countries with differing languages and cultures.

Evaluation of discomfort of Goldmann tonometry without anaesthetic.

Goldmann applanation tonometry (GAT) is considered the gold standard technique for tonometry. It is a procedure involving administration of topical anaesthetic (a drug which could have several side effects). This prevents a large number of vision care practitioners from using GAT, due to legal restrictions regarding the use of these ophthalmic drugs. The purpose of this study was to establish whether the discomfort experienced during non-anaesthetic Goldmann Applanation Tonometry (NAGAT) would be acceptable to subjects. The intensity of pain inflicted by GAT, NAGAT, Non-Contact Tonometry (NCT) and Schirmer test was assessed on thirty-one subjects enrolled in the study using the Numerical Rating Scale (NRS) to assess pain. The GAT was performed on one eye and the other three procedures were carried out in random order on the fellow eye. Initially, each subject was asked to score their Maximum Pain Without Complaint (MPWC). The MPWC and the Schirmer test were used as references to grade the pain levels. The scores for the five procedures were registered using the NRS (0-10) and compared using a non-parametric statistical analysis (Friedman test and a post-hoc analysis). In addition, IOP results for GAT and NAGAT were also compared using the t-test. The scores obtained on the NRS ranged from 0-4, 0-5, 0-8, 0-7 and 3-8 with a median of 1, 1, 2, 2, and 5, respectively for NCT, GAT, NAGAT, Schirmer and MPWC. A statistically significant difference (p = 0.01) was found between the MPWC and the four clinical tests but no difference was found between the clinical tests. There was no statistically significant difference (p = 0.71) between the IOP results for GAT and NAGAT, 14.0 ± 2.0 mmHg and 13.8 ± 2.0 mmHg (mean ± 1S.D.) respectively. The Goldmann Applanation Tonometry without anaesthetic (NAGAT) can be performed with an acceptable level of discomfort for the majority of subjects and should be performed identically to a traditional GAT, informing the subjects about the possibility of feeling a small discomfort.