Publications by authors named "A M Putz"

80 Publications

Total scattering reveals the hidden stacking disorder in a 2D covalent organic framework.

Chem Sci 2020 Jul 8;11(47):12647-12654. Epub 2020 Jul 8.

Max Planck Institute for Solid State Research Heisenbergstrasse 1 70569 Stuttgart Germany

Interactions between extended π-systems are often invoked as the main driving force for stacking and crystallization of 2D organic polymers. In covalent organic frameworks (COFs), the stacking strongly influences properties such as the accessibility of functional sites, pore geometry, and surface states, but the exact nature of the interlayer interactions is mostly elusive. The stacking mode is often identified as eclipsed based on observed high symmetry diffraction patterns. However, as pointed out by various studies, the energetics of eclipsed stacking are not favorable and offset stacking is preferred. This work presents lower and higher apparent symmetry modifications of the imine-linked TTI-COF prepared through high- and low-temperature reactions. Through local structure investigation by pair distribution function analysis and simulations of stacking disorder, we observe random local layer offsets in the low temperature modification. We show that while stacking disorder can be easily overlooked due to the apparent crystallographic symmetry of these materials, total scattering methods can help clarify this information and suggest that defective local structures could be much more prevalent in COFs than previously thought. A detailed analysis of the local structure helps to improve the search for and design of highly porous tailor-made materials.
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http://dx.doi.org/10.1039/d0sc03048aDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8163241PMC
July 2020

Impact of Moderate Cold and Salt Stress on the Accumulation of Antioxidant Flavonoids in the Leaves of Two Cultivars.

J Agric Food Chem 2021 Jun 3;69(23):6431-6443. Epub 2021 Jun 3.

Institute of Bio- and Geosciences-Plant Sciences (IBG-2), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.

The horticultural production of bell peppers generates large quantities of residual biomass. Abiotic stress stimulates the production of protective flavonoids, so the deliberate application of stress to the plants after fruit harvest could provide a strategy to valorize horticultural residuals by increasing flavonoid concentrations, facilitating their industrial extraction. Here we exposed two cultivars, a chilli and a bell pepper, to cold and salt stress and combinations thereof to determine their valorization potential. Noninvasive image-based phenotyping and multiparametric fluorescence measurements indicated that all stress treatments inhibited plant growth and reduced the leaf chlorophyll fluorescence index, with the chilli cultivar showing greater sensitivity. The fluorescence-based FLAV index allowed the noninvasive assessment of foliar luteolin glycosides. High-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis showed that moderate cold increased the levels of two foliar antioxidant luteolin glycosides in both cultivars, with bell pepper containing the highest amounts (induced to maximum 5.5 mg g DW cynaroside and 37.0 mg g DW graveobioside A) after combined stress treatment. These data confirm the potential of abiotic stress for the valorization of residual leaf biomass to enhance the industrial extraction of antioxidant and bioactive flavonoids.
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http://dx.doi.org/10.1021/acs.jafc.1c00908DOI Listing
June 2021

Proliferation of Peripheral Blood Mononuclear Cells From Healthy Piglets After Mitogen Stimulation As Indicators of Disease Resilience.

J Anim Sci 2021 May 4. Epub 2021 May 4.

Department of Large Animal Clinical Sciences, University of Saskatchewan, Saskatoon, SK, Canada.

Disease resilience refers to productivity of an animal under disease. Given the high biosecurity of pig nucleus herds, traits that can be measured on healthy pigs and that are genetically correlated with disease resilience, i.e. genetic indicator traits, offer a strategy to select for disease resilience. Our objective was to evaluate mitogen stimulation assays on peripheral blood mononuclear cells from young healthy pigs as genetic indicators for disease resilience. Data were from a natural disease challenge in which batches of 60 or 75 naïve Yorkshire x Landrace piglets were introduced every three weeks into a continuous flow barn that was seeded with multiple diseases. In this environment, disease resilience traits, including growth, treatment, and mortality rates, were recorded on 3136 pigs that were genotyped with a high-density marker panel. Peripheral blood mononuclear cells from 882 of these pigs from 19 batches were isolated from whole blood collected prior to the disease challenge and stimulated with five mitogens: concanavalin A (ConA), phytohemagglutinin (PHA), pokeweed mitogen (PWM), lipopolysaccharide (LPS), and phorbol myristate acetate (PMA). Proliferation of cells was evaluated at 48, 72, and 96 hrs and compared to unstimulated samples (rest count). Heritabilities of cell proliferation were estimated using a model with batch as a fixed effect, covariates of entry age, rest count, and complete blood count proportions of lymphocytes, monocytes, eosinophils, and basophils, and pen, litter, and animal genetics as random effects. Heritability estimates were highest for response to ConA (0.30+0.09, 0.28+0.10, 0.17+0.10, and 0.25+0.10 at 48, 72, and 96 hrs after stimulation and for area under the curve across the three time points, respectively). Estimates were in a similar range for response to PHA and PMA, but low for PWM and LPS. Responses to ConA, PHA, and PMA were moderately genetically correlated with several disease resilience traits and in the expected direction but individual estimates were not significantly different from zero due to large standard errors. In conclusion, although validation is needed, mitogen stimulation assays, in particular based on ConA, show promise as genetic indicator traits for disease resilience.
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http://dx.doi.org/10.1093/jas/skab084DOI Listing
May 2021

Comparison of Structure and Adsorption Properties of Mesoporous Silica Functionalized with Aminopropyl Groups by the Co-Condensation and the Post Grafting Methods.

Materials (Basel) 2021 Jan 29;14(3). Epub 2021 Jan 29.

Institute for Energy Security and Environmental Safety, Centre for Energy Research, Konkoly-Thege ut 29-33, 1121 Budapest, Hungary.

The adsorptive potential has been evaluated for the aminopropyl functionalized mesoporous silica materials obtained by co-condensation and post grafting methods. Nitrogen sorption, small angle neutron and X-ray scattering (SANS and SAXS) demonstrated high surface area and well-ordered hexagonal pore structure suitable for applications as adsorbents of metals from waste waters. A comparison of Cr(VI) adsorption properties of the materials prepared by different functionalization methods has been performed. The obtained results demonstrated the adsorption capacity due to the affinity of the chromium ions to the amino groups, and showed that co-condensation of tetraethoxysilane (TEOS) and 3-aminopropyl triethoxysilane (APTES) resulted in higher metal sorption capacity of the materials compared to post-synthesis grafting of aminopropyl groups onto the mesoporous silica particles.
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http://dx.doi.org/10.3390/ma14030628DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7866394PMC
January 2021

Women Walk in High Heels: Lumbar Curvature, Dynamic Motion Stimuli and Attractiveness.

Int J Environ Res Public Health 2021 01 3;18(1). Epub 2021 Jan 3.

Institute of Psychology, University of Pécs, 7624 Pécs, Hungary.

Previous studies have demonstrated that the angle of women's lumbar curvature affects men's attractiveness judgments of them. The theoretically optimal angle of lumbar curvature provides better resistance against both hyperlordosis and hypolordosis as biomechanical costs of a bipedal fetal load that could impair a woman's fertility. Since men find this attribute attractive, women aim to emphasize it by wearing high-heeled shoes. The primary objective of the present study was to test this evolutionary hypothesis using short videos presenting women walking by the camera. In line with previous findings based on static stimuli (photographs), dynamic stimuli (videos) presenting women walking in high-heeled shoes were expected to elicit increased attractiveness ratings as compared to women wearing flat shoes, which would be associated with the angle of lumbar curvature. Videos were taken of 52 female models walking in two conditions (i.e., wearing either high-heeled or flat shoes). A total of 108 participants (61 males, 47 females) rated the walking models' physical attractiveness in an online setting. Each model's lumbar curvature was measured both in high heels and in flat shoes using photographs taken of them prior to each video recording. The results showed that wearing high heels consistently increased the models' attractiveness, regardless of whether or not it decreased their natural difference from the theoretically optimal angle of lumbar curvature. Both male and female observers showed this positive effect. Furthermore, a negative correlation was found between the models' body mass index (BMI) and their perceived attractiveness scores in both conditions.
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http://dx.doi.org/10.3390/ijerph18010299DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7795698PMC
January 2021