Meta-analysis reveals a reduced surface area of the amygdala in individuals with attention deficit/hyperactivity disorder.

Despite the reported lack of structural alterations in the amygdala of individuals with attention deficit/hyperactivity disorder (ADHD) in previous meta-analyses, subsequent observational studies produced conflicting results. Through incorporating the updated data from observational studies on structural features of the amygdala in ADHD, the primary goal of this study was to examine the anatomical differences in amygdala between subjects with ADHD and their neurotypical controls. Using the appropriate keyword strings, we searched the PubMed, Embase, and Web of Science databases for English articles from inception to February 2022. Eligibility criteria included observational studies comparing the structure of the amygdala between ADHD subjects and their comparators using magnetic resonance imaging (MRI). Subgroup analyses were conducted focusing on the amygdala side, as well as the use of different scanners and approach to segmentation. The effects of other continuous variables, such as age, intelligence quotient, and male percentage, on amygdala size were also investigated. Of the 5703 participants in 16 eligible studies, 2928 were diagnosed with ADHD. Compared with neurotypical controls, subjects with ADHD had a smaller amygdala surface area (particularly in the left hemisphere) but without a significant difference in volume between the two groups. Subgroup analysis of MRI scanners and different approaches to segmentation showed no statistically significant difference. There was no significant correlation between continuous variables and amygdala size. Our results showed consistent surface morphological alterations of the amygdala, in particular on the left side, in subjects with ADHD. However, the preliminary findings based on the limited data available for analysis warrant future studies for verification.

Selective Determination of Hydrazine Hydrate on Palladium Hydrogels-modified Electrochemical Sensor / 分析化学

Palladium hydrogel capped by β-cyclodextrins (Pdβ-CD) was prepared by a facile method with β-cyclodextrins and palladium(II) chloride,which were then modified onto the surface of gold electrode. The morphology and structure of the as-prepared palladium hydrogel were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), while the electrochemistry behaviors of gold electrode modified by Pdβ-CDwere investigated by cyclic voltammetry (CV) and differential pulse voltammetry(DPV). The results indicated the sensor had high electrochemistry response to hydrazine hydrate in the presence of K+,Na+,Mg2+,NH+4,Ni+2,Mn2+,Cl-,NO-3,SO2-4,PO3-4,HCOO-, C6H5O-3. Under the optimized conditions, the oxidized peak current showed linear relationship with the concentration of hydrazine hydrate in the concentration range of 25-950 μmol/L and the limit of detection (LOD) of 1.6 μmol/L(S/N=3).Owing to the facile preparation,high sensitivity and selectivity,the sensor has potential applications in determination of hydrazine hydrate in real water samples