Casimir force densities, i.e., force per area, become very large if two solid material surfaces come closer together to each other than 10 nm. In most cases, the forces are attractive. In some cases, they can be repulsive depending on the solid materials and the fluid medium in between. This review provides an overview of experimental and theoretical studies that have been performed and focuses on four main aspects: (i) the combinations of different materials, (ii) the considered geometries, (iii) the applied experimental measurement methodologies and (iv) a novel self-assembly methodology based on Casimir forces. Briefly reviewed is also the influence of additional parameters such as temperature, conductivity, and surface roughness. The Casimir effect opens many application possibilities in microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS), where an overview is also provided. The knowledge generation in this fascinating field requires interdisciplinary approaches to generate synergetic effects between technological fabrication metrology, theoretical simulations, the establishment of adequate models, artificial intelligence, and machine learning. Finally, multiple applications are addressed as a research roadmap.

OBJECTIVE: Childhood trauma (CT) is a major environmental risk factor for an adverse course and treatment outcome of major depressive disorder (MDD). Evidence suggests that an altered regional brain activity may play a crucial role in the relationship between CT and MDD. This study aimed to clarify the relationship between CT, regional brain activity, and depression severity.
METHODS: In this study, 96 patients with MDD and 82 healthy controls (HCs) participated. Regional brain activity was measured using the fractional amplitude of low-frequency fluctuation (fALFF) and regional homogeneity (ReHo). These measures were compared between the MDD and HC groups, and the values of different brain regions were extracted as moderators.
RESULTS: Increased fALFF and ReHo values were observed in the left middle temporal gyrus in the MDD group compared with the HC group (p < 0.001). Furthermore, the fALFF and ReHo values moderated the positive correlation between the Childhood Trauma Questionnaire (CTQ) score, 17-item Hamilton Depression Rating Scale (HAMD-17) total score, and retardation factor score in the MDD group (all, p < 0.05). Finally, as the fALFF and ReHo values increased, the positive correlations between CTQ, HAMD-17 total, and retardation dimension scores became stronger.
CONCLUSIONS: Our study highlighted the crucial role of altered brain function in connecting childhood maltreatment with depressive symptoms. Our findings indicate that an altered regional brain activity could explain the potential neurobiological mechanisms of MDD symptoms, offering the opportunity to function as a powerful diagnostic biomarker.

BACKGROUND: The incidence of inflammatory bowel disease (IBD) in children is on the increase worldwide. Growth disorders are common in pediatric patients with inflammatory bowel disease. The aim of this paper is to investigate anthropometric indicators, including height and weight in children with inflammatory bowel disease in Saxony, one of the German federal states, and to evaluate growth trends in patients by comparing their height and weight with that of healthy children in Germany.
METHODS: In Saxony, all children and adolescents with IBD were registered in the Saxon Pediatric IBD Registry from 2000 to 2014. The data used are therefore based on a total area-wide survey over 15 years. For this study, 421 datasets of children and adolescents aged 0-14 years with Crohn\'s disease (CD) (n = 291) or ulcerative colitis (UC) (n = 130) were analyzed. Z-score and percentile calculations were used to compare differences between IBD patients and the general population.
RESULTS: The children with CD or UC (both sexes) had a significant lower weight at diagnosis (the mean weight z-score had negative values) versus the general population. The weight values lay mostly below P50 (the 50th percentile, median), more precisely, mostly between P10 and P50 of the body weight child growth curve for corresponding sexes (KiGGS 2003-2006). The height values of both sexes at diagnosis lay also mostly below P50 (the 50th percentile, median) of the child body growth curve for corresponding sexes (KiGGS 2003-2006), i.e. the mean height z-score was negative. But only the children with CD had a significant lower height, more precisely, mostly between P25 and P50 versus the general population (KIGGS). For children with UC the difference was not significant.
CONCLUSIONS: In pediatric patients with IBD the possibility of growth disturbance, mainly in the form of weight retardation, is very probable.

Many optical techniques have been used in various diagnostics and biomedical applications since a decade and polarization imaging is one of the non-invasive and label free optical technique to investigate biological samples making it an important tool in diagnostics, biomedical applications. We report a multispectral polarization-based imaging of oral tissue by utilizing a polarization microscope system with a broadband-light source. Experiments were performed on oral tissue samples and multispectral Stokes mapping was done by recording a set of intensity images. Polarization-based parameters like degree of polarization, angle of fast axis, retardation and linear birefringence have been retrieved. The statistical moments of these polarization components have also been reported at multiples wavelengths. The polarimetric properties of oral tissue at different stages of cancer have been analyzed and significant changes from normal to pre-cancerous lesions to the cancerous are observed in linear birefringence quantification as (1.7 ± 0.1) × 10-3 , (2.5 ± 0.2) × 10-3 and (3.3 ± 0.2) × 10-3 respectively.

In forensic casework, examination of garment damage can provide insight into the mechanism of the specific cause of fiber failure. Different methods of damage impart differing physical characteristics on individual fibers. These alterations are determined by a multitude of factors, among them increased temperature of affected fibers. The process of rapid shear occurs in thermoplastic materials following high-speed impact. It results in distinct features caused by excessive heat generated through the interaction, which is unable to dissipate at a rate that would leave the fibers unchanged. Rapid shear characteristics can be differentiated from other fracture patterns through non-destructive microscopical methods and with a minimal sample size. Fabric samples were shot under heated, chilled, and water-saturated conditions, using ammunition of varying velocities. Analyses performed on the defects were conducted using stereomicroscopy, polarized light microscopy and scanning electron microscopy. Globular-shaped fiber ends, characteristics attributed specifically to rapid shear, were observed in all nylon samples. Through this study, it was determined that the environmental conditions employed did not affect fiber end changes associated with rapid shear.

This study investigates the relationships between the hydration kinetics of waterglass-activated slag and the development of its physical-mechanical properties, as well as its color change. To modify the calorimetric response of alkali-activated slag, hexylene glycol was selected from various alcohols for in-depth experiments. In presence of hexylene glycol, the formation of initial reaction products was restricted to the slag surface, which drastically slowed down the further consumption of dissolved species and slag dissolution and consequently delayed the bulk hydration of the waterglass-activated slag by several days. This allowed to show that the corresponding calorimetric peak is directly related to the rapid evolution of the microstructure and physical-mechanical parameters and to the onset of a blue/green color change recorded as a time-lapse video. Workability loss was correlated with the first half of the second calorimetric peak, while the most rapid increase in strengths and autogenous shrinkage was related to the third calorimetric peak. Ultrasonic pulse velocity increased considerably during both the second and third calorimetric peak. Despite the modified morphology of the initial reaction products, the prolonged induction period, and the slightly reduced degree of hydration induced by hexylene glycol, the overall mechanism of alkaline activation remained unchanged in the long-term perspective. It was hypothesized that the main issue of the use of organic admixtures in alkali-activated systems is the destabilizing effect of these admixtures on soluble silicates introduced into the system with an activator.

Styrene-butadiene rubber (SBR) has been extensively applied to enhance the toughness of hardened cement. The instability of existing liquid latex leads to difficulties in storage and transportation, and even performance regression. Thus, the well-dispersed carboxylated butylbenzene (SISBR) latex powders were fabricated through the seed emulsion polymerization of liquid polybutadiene (LPB), styrene (St), itaconic acid (IA), and sodium p-styrenesulfonate (SSS) to overcome the difficulties. The dispersion performance of latex powders with various IA amounts was quantitatively evaluated using particle size distribution, zeta potential, and ultraviolet-visible spectrophotometry. Results showed that the carboxylic ionic (COO-) from IA enhanced the dispersing abilities of SISBR latex powders, which ensured the uniform distribution in water. Based on this, the influence of latex powder on cement was assessed mainly by fluidity, isothermal heat flow calorimetry, X-ray diffraction (XRD), and triaxial mechanical testing. Results showed the fluidity and dispersion performance of cement were improved with more IA in latex, while the hydration of cement was retarded due to excessive adsorption of carboxyl (-COOH) groups in IA. Triaxial mechanical testing showed that cement with SISBR-3 (latex containing 3% IA) exhibited the minimal elastic modulus of 3.16 GPa, which was lower than that of plain cement (8.34 GPa).

Deuterated water has been applied in hydrogeological tracer tests in recent years. However, there is a contradiction in the conservativeness of the artificial deuterium (D/2H). In this study, what circumstances HDO behaved truly conservatively were investigated through the laboratory-scale sand tank by comparing with the widely used tracer chloride (Cl-). In addition, the advection-dispersion equation (ADE) and dual-domain mass transfer (DDMT) equation were employed to describe the breakthrough curves (BTCs) of tracers. Reasons for the non-conservativeness of HDO were discussed comprehensively for the first time. HDO behaved conservatively when transported in the porous media with high permeability, and ADE could describe BTCs successfully. While HDO presented the phenomenon of retardation in media with low permeability, especially in the clay medium. DDMT was more suitable for demonstrating delayed BTCs. Hydrogen bonds between HDO and H2O, the isotopic exchange effect, and the dual-domain of the media were used to explain the retardation of HDO. The retardation factor (R = 1.27) was used to describe transporting behaviors of HDO in clay first. The relatively large molecular coefficient of HDO could make the proportion of immobile regions of HDO greater than that of Cl-. Tracers tend to be delayed when transported in the media with the larger porosity, smaller hydraulic gradient, and lower permeability. This work provides more considerations for using deuterium as artificial tracers in hydrogeological tests.

For a safe enclosure of contaminants, for instance in deep geological repositories of radioactive waste, any processes retarding metal migration are of paramount importance. This study focusses on the sorption of trivalent actinides (Am, Cm) and lanthanides (Eu) to the surface of muscovite, a mica and main component of most crystalline rocks (granites, granodiorites). Batch sorption experiments quantified the retention regarding parameters like pH (varied between 3 and 9), metal concentration (from 0.5 µM Cm to 10 µM Eu), or solid-to-liquid ratio (0.13 and 5.25 g·L-1). In addition, time-resolved laser fluorescence spectroscopy (TRLFS) using the actinide Cm(III) identified two distinct inner-sphere surface species. Combining both approaches allowed the development of a robust surface complexation model and the determination of stability constants of the spectroscopically identified species of (S-OH)2M3+ (logKo -8.89), (S-O)2M+ (logKo -4.11), and (S-O)2MOH (logKo -10.6), with all values extrapolated to infinite dilution. The inclusion of these stability constants into thermodynamic databases will improve the prognostic accuracy of lanthanide and actinide transport through groundwater channels in soils and crystalline rock systems.

A field injection experiment was performed in an anoxic sandy aquifer over 6 days to assess sorption characteristics of 7 commonly applied pesticides in agriculture and 2 frequently detected metabolites. Pesticide use changed considerably in the last decades, and there is insufficient knowledge of the fate of currently used pesticides in aquifers. Injected water arrival was monitored at 6 depth intervals of 1 m ranging from 11.4 to 32.2 m-below surface level with varying organic carbon contents (0.057-0.91%d.w.) to examine intra-aquifer variations in sorption. Observed pesticide concentrations were fit using a non-linear least squares routine to an advection-dispersion equation, from which retardation factors (R) were obtained. Pesticide degradation did not significantly influence the simulated R during the experiment. We observed that bentazon and cycloxydim were most mobile with R < 1.1 at all depths. Desphenyl chloridazon, methyl desphenyl chloridazon, and imidacloprid were, on average, less mobile, with maximum R of 1.5. Boscalid, chloridazon, fluopyram, and flutolanil showed a larger range of R, and R > 2.0 were observed in the shallowest part of the aquifer. Largest R were observed at the top of the aquifer and decreased with depth. Koc values varied similarly, which indicates that sorption is not only influenced by sedimentary organic matter (SOM) content but also by its sorption reactivity. Obtained sorption parameters were substantially lower than reported in a widely used pesticide sorption database, which suggests that sorption parameters are influenced by methodological differences and variations in the sorption reactivity of SOM. The large intra-aquifer variations in pesticide sorption highlights that aquifer heterogeneity should be considered in groundwater risk assessments.