Body Dissatisfaction Directs Avatar Perception: Embodiment and Selective Visual Attention in Body Mass-Modified Self-Avatars.

Human agents immersed in metaverse technologies such as virtual reality (VR) are routinely disconnected from their actual physical appearance and embodied in another virtual body, referred to as self-avatar. Such body transformations can have implications for patients with eating disorders, or persons with extreme body dissatisfaction (BD). Changes in BD, weight anxiety, or body image are theoretically linked to visual selective attention, which can be measured with eye tracking. In the present study, 43 women with high or low BD were immersed in animated body weight-manipulated self-avatars in VR. Before a brief mirror exposure with their self-avatars, they experienced synchronous visuomotor and visuo-tactile contingencies in VR to increase embodiment, delivered through small movement exercises with real-time animation from first-person perspective and passive haptics. In a crossover study design, self-avatar weight was manipulated (normal weight vs. overweight) in both groups (low BD vs. high BD), and subjective experience was assessed before and after exposure. In contrast to our hypotheses, BD was not affected by the self-avatar condition. Embodiment decreased during mirror exposure, possibly due to the avatars wearing head-mounted displays. Interestingly, disembodiment was stronger in women with low BD. Furthermore, eye tracking showed that participants with high BD looked longer at weight-related body parts when immersed in the overweight self-avatar, whereas participants with low BD looked longer at weight-related body parts when immersed in the normal weight self-avatar. Overall, the results support body-specific visual attention and suggest that particularly participants with low BD show stronger disembodiment during self-avatar mirror exposure, possibly alleviating momentary body experience. Preregistration: https://doi.org/10.23668/psycharchives.4949.

Surface-modified CAU-10 MOF materials as humidity sensors: impedance spectroscopic study on water uptake.

Metal-organic frameworks (MOFs) are crystalline microporous materials with tunable chemical and physical properties. By combining various metal clusters with different interconnecting organic linkers, the pore structure, crystallinity, as well as the surface properties can be modified. In the present work, modification of the organic linker molecules is utilized to synthesize CAU-10 type MOFs with variable affinity of the pore surface to water. In principle, this should influence the accessibility of the pores for water vapor and therefore offer a tool to control its sorption properties. For a deeper understanding we studied the water sorption characteristics and compared the results to the conductive and dielectric properties studied by impedance spectroscopy. Spectra in a wide frequency range from 1 mHz to 1 MHz were recorded. Data analysis is performed using the Havriliak-Negami model. The MOFs are also tested as sensitive layers for capacitive humidity sensing by correlating the change in permittivity of the materials with the amount of physisorbed water. Such an MOF-based sensor was tested with respect to environmental monitoring and compared to a commonly used commercial humidity sensor.

Three Series of Sulfo-Functionalized Mixed-Linker CAU-10 Analogues: Sorption Properties, Proton Conductivity, and Catalytic Activity.

Ten mixed-linker metal-organic frameworks [Al(OH)(m-BDC-X)(1-y)(m-BDC-SO3H)y] (H2BDC = 1,3-benzenedicarboxylic acid; X = H, NO2, OH) exhibiting the CAU-10-type structure were synthesized. The compounds can be grouped into three series according to the combination of ligands employed. The three series of compounds were obtained by employing different ratios of m-H2 BDC-X and m-H2BDC-SO3Li. The resulting compounds, which are denoted CAU-10-H/Sx, -N/Sx and -O/Sx, show exceptionally high thermal stability for sulfonated materials of up to 350 °C. Detailed characterization with special focus on polarity and acidity was performed, and the impact of the additional SO3H groups is clearly demonstrated by changes in the sorption affinities/capacities towards several gases and water vapor. In addition, selected samples were evaluated for proton conductivity and as catalysts for the gas-phase dehydration of ethanol to ethylene. While only very low proton conductivities were observed, a pronounced increase in catalytic activity was achieved. Although reactions were performed at temperatures of 250 and 300 °C for more than 40 h, no desulfonation and no loss of crystallinity were observed, and stable ethanol conversion resulted. This demonstrates the high stability of this material.

New Al-MOFs based on sulfonyldibenzoate ions: a rare example of intralayer porosity.

A new sulfone-functionalized metal-organic framework [Al(OH)(SDBA)]·0.25DMF, denoted CAU-11, was synthesized using a V-shaped linker molecule 4,4'-sulfonyldibenzoic acid (H2SDBA). The crystal structure was solved from synchrotron X-ray powder diffraction data. Chains of trans corner-sharing AlO6 octahedra are interconnected by the carboxylate groups to form layers (ABAB stacking). Within the layers, hydrophobic lozenge-shaped pores with a diameter of 6.4 × 7.1 Å(2) are present inducing permanent porosity (aBET = 350 m(2) g(-1) and Vmicro = 0.17 cm(3) g(-1)). With the application of HT-methods (HT = high throughput), the isoreticular carboxylate functionalized compound [Al(OH)(H2DPSTC)]·0.5H2O (CAU-11-COOH) was synthesized using the linker molecule 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride (DPSDA), which hydrolyzes under the reaction conditions. Due to the additional noncoordinating carboxylic acid groups the pores are hydrophilic. Changing the molar ratio of Al(3+) to linker lead to the discovery of a second new compound [Al2(OH)2(DPSTC)(H2O)2]·0.5H2O (CAU-12). In CAU-12 the linker molecule is fully deprotonated which leads to different connectivity compared to the structure of CAU-11-COOH. Thermal activation of CAU-12 leads to dehydration and transformation of the structure to [Al2(OH)2(DPSTC)]·nH2O (CAU-12-dehy). Coordinated water molecules were removed, and the coordination site is replaced by the previously noncoordinating O atom of the adjacent carboxylate group. The SO2-groups point into the pores resulting in a highly hydrophobic three-dimensional framework. The compounds exhibit high thermal stability in air at least up to 420 °C. Synthesis of CAU-11 can be easily scaled up in very high yields (98%).

Enhancing the water stability of Al-MIL-101-NH2 via postsynthetic modification.

The resistance of metal-organic frameworks towards water is a very critical issue concerning their practical use. Recently, it was shown for microporous MOFs that the water stability could be increased by introducing hydrophobic pendant groups. Here, we demonstrate a remarkable stabilisation of the mesoporous MOF Al-MIL-101-NH2 by postsynthetic modification with phenyl isocyanate. In this process 86 % of the amino groups were converted into phenylurea units. As a consequence, the long-term stability of Al-MIL-101-URPh in liquid water could be extended beyond a week. In water saturated atmospheres Al-MIL-101-URPh decomposed at least 12-times slower than the unfunctionalised analogue. To study the underlying processes both materials were characterised by Ar, N2 and H2 O sorption measurements, powder X-ray diffraction, thermogravimetric and chemical analysis as well as solid-state NMR and IR spectroscopy. Postsynthetic modification decreased the BET equivalent surface area from 3363 to 1555 m(2) g(-1) for Al-MIL-101-URPh and reduced the mean diameters of the mesopores by 0.6 nm without degrading the structure significantly and reducing thermal stability. In spite of similar water uptake capacities, the relative humidity-dependent uptake of Al-MIL-101-URPh is slowed and occurs at higher relative humidity values. In combination with (1) H-(27) Al D-HMQC NMR spectroscopy experiments this favours a shielding mechanism of the Al clusters by the pendant phenyl groups and rules out pore blocking.

A zirconium squarate metal-organic framework with modulator-dependent molecular sieving properties.

We report the first zirconium metal-organic framework based on squaric acid, representing the member with the smallest unit cell in the isoreticular UiO-66 family. Its molecular sieving properties are strongly influenced by the monocarboxylic acid modulator incorporated during synthesis.

Sulfonyl chlorides as an efficient tool for the postsynthetic modification of Cr-MIL-101-SO3H and CAU-1-NH2.

Postsynthetic modification can be used to introduce sulfonamide functionalities into MOF frameworks. Using sulfonyl chlorides as reactive intermediates, Cr-MIL-SO3H and CAU-1-NH2 have been further modified to give hitherto unknown functionalized MOFs in which a sulfonamide group is bound to the framework either by its N or its S atom.

Effective mercury sorption by thiol-laced metal-organic frameworks: in strong acid and the vapor phase.

Free-standing, accessible thiol (-SH) functions have been installed in robust, porous coordination networks to provide wide-ranging reactivities and properties in the solid state. The frameworks were assembled by reacting ZrCl4 or AlCl3 with 2,5-dimercapto-1,4-benzenedicarboxylic acid (H2DMBD), which features the hard carboxyl and soft thiol functions. The resultant Zr-DMBD and Al-DMBD frameworks exhibit the UiO-66 and CAU-1 topologies, respectively, with the carboxyl bonded to the hard Zr(IV) or Al(III) center and the thiol groups decorating the pores. The thiol-laced Zr-DMBD crystals lower the Hg(II) concentration in water below 0.01 ppm and effectively take up Hg from the vapor phase. The Zr-DMBD solid also features a nearly white photoluminescence that is distinctly quenched after Hg uptake. The carboxyl/thiol combination thus illustrates the wider applicability of the hard-and-soft strategy for functional frameworks.