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Amygdala and serotonergic system abnormalities have been documented in major depressive disorder (MDD). However, most studies have been conducted on recurrent MDD, and only a few have assessed their interaction. This study aimed to concurrently examine both the amygdala and serotonergic systems and their clinical relevance in first-episode, drug-naïve MDD. This study included 27 patients with first-episode, drug-naïve MDD and 27 age- and gender-matched healthy controls (HCs). The amygdala substructure volumes were performed with Freesurfer from a 1.5 T magnetic resonance image. Serotonin transporter (SERT) availability was detected by single-photon emission computed tomography with 123I-ADAM. The Benjamini-Hochberg method was applied to adjust for multiple comparisons. No significant difference was found in the amygdala substructure volume and SERT availability between the two groups, respectively. Within MDD patients, the right medial, cortical nucleus, and centromedial volumes were positively associated with caudate SERT availability, respectively. Moreover, the right lateral nucleus volume in the amygdala was positively correlated with depression severity. However, these significances did not survive correction for multiple testing. There were no significant abnormalities in the amygdala substructure volumes and SERT availability in patients with first-episode, drug-naïve MDD. We did not observe an association between amygdala substructure volume and serotonergic dysregulation and their correlations with depression severity in patients with MDD. A larger sample size is warranted to elucidate the actual correlation. • The MDD group vs. controls showed no significant differences in the amygdala substructure volumes and SERT availability. • Amygdala substructure volumes were not associated with SERT availability in patients with MDD. • Neither amygdala nucleus volume nor SERT availability was associated with depression severity in MDD patients. [ABSTRACT FROM AUTHOR]

Abstract Surface energies described by Hansen solubility parameters (HSP) of a synthetic organophilic fluoromica (MAE), molybdenum disulfide (MoS 2 ), and graphene are used to predict their delamination properties in a cyclic olefin copolymer (COC). This prediction suggests MAE as the most appropriate filler for COC, followed by MoS 2 and graphene. Nanocomposites are prepared via solution process and have been investigated on their delamination state using X-ray-diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), and angle-resolved light scattering (ARS). Nanocomposites based on MAE shown morphologies close to complete delamination. Agglomerations are detected in the case of MoS 2 and graphene. For a potential barrier application, water vapor transmission rates (WVTR) are experimentally determined. In such nanocomposites, inorganic fillers increase the diffusion length of water, known as tortuous path model, which enhances the barrier properties. Highest barrier enhancements are obtained using MAE based nanocomposites reducing the WVTR down to 40% of the initial value. The prediction of delamination based on Hansen solubility parameters is found to be a very helpful tool for selecting fillers in composites. [ABSTRACT FROM AUTHOR]

The influence of different surface energies described by Hansen solubility parameters (HSP) on the exfoliation of organophilic fluoromicas is investigated. HSP values of four synthetic organophilic fluoromica with different surfactants have been predetermined. Those surfactants change the fluoromica surface energies described by HSP. The HSP are used to calculate the dispersibility of the various organophilic fluoromica in chloroform via Flory-Huggins (F-H) theory. The F-H parameter (χ) describes the effective difference in HSP related surface energies of particles and chloroform molecules, which is related to the energy cost of exfoliation. An influence of F-H parameter is detected on the delamination state of organophilic fluoromica. The delamination state is evaluated quantitatively using atomic force microscopy (AFM). In the case of a high F-H parameter (χ > 0.15), aggregated and unstable fluoromica dispersions are obtained. Whereas in the case of F-H parameters near zero, exfoliated and stable fluoromica dispersions are achieved. The presence of surfactant on the surface of exfoliated fluoromica flakes is proven by Fourier-transform infrared spectroscopy (FT-IR), and density functional theory (DFT) calculation. [ABSTRACT FROM AUTHOR]

A method to measure Hansen solubility parameters for organophilic fluoromica is developed. For this purpose, fluoromica with four different intercalated molecules (surfactants) have been dispersed in various solvents. These surfactants change the fluoromica surface energies described by Hansen solubility parameters (HSP). The three Hansen solubility parameters (dispersion, polar and hydrogen bonding) of different organophilic fluoromicas have been obtained by using gravimetric analysis. The dispersion parameters for all four organophilic fluoromicas are almost identical, with a value around 17 MPa . Whereas polar and H-bonding parameters are varying with the used surfactants. Surprisingly the polar and hydrogen bonding values for hydrophobic alkyl chain tailored surfactants are higher than those for a hydrophilic surfactant with poly(ethylene glycol) chains. The determined HSP values allow calculating the dispersibility of the organophilic fluoromica in solvents via the Flory-Huggins (F-H) parameter. These F-H parameters describes the effective difference in HSP related surface energies of particles and solvent molecules and are used to identify potential solvents for an exfoliation process. With this approach, beside known solvents such as chloroform, also new potential candidates such as trichloroethylene, and benzyl ethyl ether are identified for dispersing/exfoliating modified organophilic fluoromica. This work is accompanied by X-ray diffraction (XRD) measurements to gain knowledge about the interlayer space of the different organophilic fluoromicas. [ABSTRACT FROM AUTHOR]