Search Results (30)

Plant architecture is a crucial trait for ornamental plants. Chrysanthemum with prostrate growth habit is a novel cultivar group of ground-cover chrysanthemum, which have high ornamental value, strong lodging resistance, and outstanding landscape greening capability. To explore the genetic mechanism underlying the prostrate growth habit in chrysanthemum, we used tetraploid prostrate-type Chrysanthemum yantaiense as the female parent and erect-type Chrysanthemum indicum as the male parent to produce four generations (P₁, P₂, F₁, F₂). Five traits related to prostrate growth habit in chrysanthemum were investigated including plant height (PH), crown width of the plant (CP), creeping index (CI), gravitropic set-point angle (GSA), and growth habit (GH). The major gene plus polygene mixed inheritance analysis was conducted on five traits across four generations over two years. For the five traits, the coefficients of variation (CVs) were wide-ranging and high (16.64–42.75%), with the PH having the highest CV among them. Genetic analysis revealed that PH conformed to the additive-dominant-epistatic polygene model (C-0) and the model of two equally dominant major genes plus additive-dominant polygene (E-5). The most suitable genetic model for CI was an additive-dominant major gene plus additive-dominant-epistatic polygene model (D-0). The best-fit models for CP and GH were both C-0. For GSA, the best-fit models were E-4 and C-0. Additionally, it appeared that both genetic and environmental factors influenced the prostrate growth habit, as the heritability of major genes and polygenes was less than 50%. This study can serve as a theoretical foundation for the mapping of quantitative trait loci (QTLs) and further exploration of the genetic mechanisms underlying plant architecture in chrysanthemum. Full article

Retina-like photoimaging devices with features such as a wide-field-of-view and high spatial resolution have wide application prospects in retinal prosthetics and remote sensing. However, the fabrication of flexible and conformal surfaces is hindered by the incompatible microfabrication processes of traditional rigid, silicon-based substrates. A kirigami strategy for hemispherical surface assembly is proposed to construct a MoS₂-based retina-like photodetector array. The device is first fabricated on a flat polyimide (PI) substrate and then tailored using a laser. By approximating the spherical surface using planar sectors, the laser-cut PI film can tightly adhere to the PDMS spherical shell without significant wrinkles. The responsivity and specific detectivity of our conformal photodetector can reach as high as 247.9 A/W and 6.16 × 10¹¹ Jones, respectively. The array integrates 180 pixels on a spherical crown with a radius of 11 mm, and a hollow letter “T” is successfully recognized. Comprehensive experimental results in this work reveal the utility of our device for photoelectric detection and imaging. We believe that our work provides a new methodology for the exploitation of 2D material-based retinal image sensors. Full article

We study the structures of 24-crown-8/H⁺/diaminopropanol (CR/DAPH⁺) and 24-crown-8/CsF/H⁺/diaminopropanol (CR/CsF/DAPH⁺) non-covalent host–guest complexes in both the gas phase and aqueous solution using the density functional theory (DFT) method. We examine the environment (complexation with CR vs. solvation) around the guest functional groups (ammoium, hydroxyl, and amino) in the CR/DAPH⁺ and CR/CsF/DAPH⁺ complexes. We find that the gas-phase configurations with the ‘naked’ hydroxyl/amino devoid of H-bonding with CR or CR/CsF are structurally correlated with the lowest Gibbs free energy conformers in aqueous solution in which the functional groups are solvated off the CR or CR/CsF host. We predict that the latter thermodynamically disadvantageous host–guest configurations would be identified in the gas phase by infrared multiphoton dissociation (IRMPD) spectroscopy, originating from the complexes in aqueous solution. This predicted ‘thermodynamic reversal’ and ‘structural correlation’ of the host–guest configurations in the gas phase vs. in solution are discussed in relation to the possibility of obtaining information on host–guest–solvent interactions in the solution phase from the gas-phase host–guest configurations. Full article

Several D-amino acid residue-containing peptides (DAACPs) with antimicrobial, cardio-excitatory, and neuronal activities have been identified in various species. The L-Asn-D-Trp-L-Phe-NH₂ (N(dW)F) tripeptide, derived from Aplysia kurodai, exhibits cardiac activity in invertebrates. The chirality of the tryptophan residue at the second position in N(dW)F influences its conformation and biological characteristics. We demonstrated the chiral separation of N(dW)F and its diastereomer NWF using (S)-3,3′-diphenyl-1,1′-binaphthyl-20-crown-6-ether columns (CR-I(+)). A reduction in the ratio of acetonitrile and methanol in the mobile phase allowed the complete separation of N(dW)F and its diastereomer, improving the separation factor (α) from 0.96 to 6.28. Molecular dynamics simulations revealed that the interaction of N(dW)F with CR-I(−) was more favorable than with CR-I(+). These findings indicate that the structure of the CR-I column stereoselectively recognizes peptides and facilitates the separation of naturally occurring D-amino acid residue-containing tripeptides. Full article

Crown ether is widely used in water purification because of its ring structure and good selective adsorption of specific heavy metals. However, its high cost and difficulty in recycling limit the purification of heavy metals in water. The anisotropic [2,4]-dibenzo-18-crown-6-modified bamboo pulp aerogel (DB18C6/PA) is successfully synthesized by microwave irradiation and directional freezing technology. The physical and chemical properties of DB18C6/PA are analyzed by FTIR, XPS, SEM, TEM, TGA, surface area and porosity analyzers. Single or multivariate systems containing Pb²⁺, Cu²⁺ and Cd²⁺ are used as adsorbents. The effects of the DB18C6 addition amount, pH, initial concentration and adsorption temperature on the adsorption of DB18C6/PA are systematically explored. Pseudo-first-order kinetic models, pseudo-second-order kinetic models and the isothermal adsorption models of Langmuir and Freundlich are used to fit the experimental data. The adsorption selectivity is analyzed from the distribution coefficient and the separation factor, and the adsorption mechanism is discussed. The results show that anisotropic DB18C6/PA has the characteristics of 3D directional channels, high porosity (97.67%), large specific surface area (103.7 m²/g), good thermal stability and regeneration (the number of cycles is greater than 5). The surface has a variety of functional groups, including a hydroxyl group, aldehyde group, ether bond, etc. In the single and multivariate systems of Pb²⁺, Cu²⁺ and Cd²⁺, the adsorption process of DB18C6/PA conforms to the pseudo-second-order kinetic model, and the results conform to the Freundlich adsorption isothermal model (a few of them conformed to the Langmuir adsorption isothermal model), indicating that chemical adsorption and physical adsorption are involved in the adsorption process, and the adsorption process is a spontaneous endothermic process. In the single solution system, the maximum adsorption capacities of Pb²⁺, Cu²⁺ and Cd²⁺ by DB18C6/PA are 129.15, 29.85 and 27.89 mg/g, respectively. The adsorption selectivity of DB18C6/PA on Pb²⁺, Cu²⁺ and Cd²⁺ is in the order of Pb²⁺ >> Cu²⁺ > Cd²⁺. Full article

Complexation between carnitine and acetylated or benzylated pyrogallol[4]arenes was studied in DMSO via dynamic NMR, UV-vis spectroscopy, and in the gas phase via electrospray ionization-mass spectrometry (ESI-MS). In the presence of benzylated tetra(phenyl)pyrogallol[4]arene, the interaction with carnitine via NMR was evident and was confirmed by means of UV-vis spectroscopy, where the formation of a host–guest-type complex was observed; this was stable and exhibited a change to a clear color. With benzylated tetra(propyl)pyrogallol[4]arene, the results showed that there was no interaction with the neurotransmitter. A plausible explanation for this behavior is based on the dynamic behavior of the benzylated tetra(propyl)pyrogallol[4]arene, and this shows the dependence on the size of the cavities and the substituent on the lower rim of the pyrogallo[4]arenes. Suitable crystals of O-acetylated-tetra(propyl)calix[4]pyrogallolarene were obtained and were characterized through an X-ray crystal structure determination. Full article

C-tetra(4-methoxyphenyl)calix[4]resorcinarene was synthesized by hydrochloric acid-catalysed cyclocondensation of resorcinol and 4-methoxybenzaldehyde. Under these conditions, the reaction produces a conformational mixture of crown and chair structural conformers, which were separated and characterized by chromatographic and spectroscopic techniques. The antioxidant activity of both conformers was measured by using the DPPH assay, through which it was observed that the chair conformer showed greater antioxidant activity (IC₅₀ = 47.46 ppm) than the crown conformer (IC₅₀ = 78.46 ppm). Additionally, it was observed that the mixture of both conformers presented lower antioxidant activity than either conformer in isolation. The results found suggest that the chair conformer has efficient antioxidant activity that makes it a potential target for further research. Full article

This article presents the synthesis and molecular dynamics investigation of three novel cyclic thioethers: 2,3-(4′-methylbenzo)-1,4,7,10-tetrathiacyclododeca-2-ene (compound 1), 2,3,14,15-bis(4′,4″(5″)-methylbenzo)-1,4,7,10,13,16,19,22,25-octathiacyclotetracosa-2,14-diene (compound 2), and 2,3,8,9-bis(4′,4″(5″)-methylbenzo)-1,4,7,10-tetrathiacyclododeca-2,8-diene (compound 3). The compounds exhibit relatively high glass transition temperatures (T_g), which range between 254 and 283 K. This characteristic positions them within the so-far limited category of crown-like glass-formers. We demonstrate that cyclic thioethers may span both the realms of ordinary and sizeable molecular glass-formers, each featuring distinct physical properties. Furthermore, we show that the T_g follows a sublinear power law as a function of the molar mass within this class of compounds. We also reveal multiple dielectric relaxation processes of the novel cyclic thioethers. Above the T_g, their dielectric loss spectra are dominated by a structural relaxation, which originates from the cooperative reorientation of entire molecules and exhibits an excess wing on its high-frequency slope. This feature has been attributed to the Johari–Goldstein (JG) process. Each investigated compound exhibits also at least one intramolecular secondary non-JG relaxation stemming from conformational changes. Their activation energies range from approximately 19 kJ/mol to roughly 40 kJ/mol. Finally, we analyze the high-pressure molecular dynamics of compound 1, revealing a pressure-induced increase in its T_g with a dT_g/dp coefficient equal to 197 ± 8 K/GPa. Full article

Theoretical tree crop ideotypes have long and narrow live crowns with a high total leaf area. This crown form allows more efficient exploitation of site resources, in part by physically occupying less growing space per unit leaf area and by packing a greater number of trees into a given area. Genetic selection for crop ideotypes has been proposed as a strategy for maximizing productivity per unit area in stands managed under intensive silviculture. The primary objective of this study was to test the relationship between the relative growth performance of different families in a Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) progeny test and morphological crown attributes that conform to a theoretical crop ideotype. The overarching goal was to identify attributes conferring superior height and diameter growth on families and to facilitate the incorporation of these attributes and associated growth mechanisms into hybrid growth models for intensively managed plantations. Crown structural attributes were measured on destructively sampled trees and averaged for the entire crown and each third of live crown length among families. Multivariate analysis revealed that crown attributes averaged over the entire crown performed best for identifying families with different height and diameter growth, followed successively by the bottom, middle, and top crown third. Trees with relatively short branch lengths and steep branch angles tended to have higher total leaf area per unit crown length (TLACL), and this structural attribute showed a strong positive correlation with cumulative diameter growth. The ratio of crown width to crown length (CWL) was moderately and negatively correlated with cumulative height growth. The families displaying the most rapid diameter growth in this progeny test conformed to a theoretical crop ideotype, while those with the most rapid height growth displayed crown attributes with a less obvious relationship to the crop ideotype concept. TLACL implied one possible mechanism driving genetic gain in Douglas-fir families, given its high heritability and strongly positive correlation with growth performance. Incorporating TLACL as an explanatory variable in diameter growth models could at least partly represent different genetic levels. TLACL is less strongly correlated with height growth rate, so incorporating CWL may better represent genetic effects on height growth models. Full article

In the present work, we report the synthesis of isomeric heteronuclear terbium(III) and yttrium(III) triple-decker phthalocyaninates [(BuO)₈Pc]M[(BuO)₈Pc]M*[(15C5)₄Pc] (M = Tb, M* = Y or M = Y, M* = Tb, [(BuO)₈Pc]²⁻–octa-n-butoxyphthalocyaninato-ligand, [(15C5)₄Pc]²⁻–tetra-15-crown-5-phthalocyaninato-ligand). We show that these complexes undergo solvation-induced switching: the conformers in which both metal centers are in square-antiprismatic environments are stabilized in toluene, whereas in dichloromethane, the metal centers M and M* are in distorted prismatic and antiprismatic environments, respectively. This conclusion follows from the detailed analysis of lanthanide-induced shifts in ¹H NMR spectra, which makes it possible to extract the axial component of the magnetic susceptibility tensor ${\mathsf{\chi }}_{\mathrm{ax}}^{\mathrm{Tb}}$ and to show that this term is particularly sensitive to conformational switching when terbium(III) ion is placed in the switchable “M” site. This result provides a new tool for controlling the magnetic properties of lanthanide complexes with phthalocyanine ligands. Full article

trans-3,4-Dihydroxyselenolane (DHS), a water-soluble cyclic selenide, exhibits selenoenzyme-like unique redox activities through reversible oxidation to the corresponding selenoxide. Previously, we demonstrated that DHS can be applied as an antioxidant against lipid peroxidation and a radioprotector by means of adequate modifications of the two hydroxy (OH) groups. Herein, we synthesized new DHS derivatives with a crown-ether ring fused to the OH groups (DHS-crown-n (n = 4 to 7), 1–4) and investigated their behaviors of complex formation with various alkali metal salts. According to the X-ray structure analysis, it was found that the two oxygen atoms of DHS change the directions from diaxial to diequatorial by complexation. The similar conformational transition was also observed in solution NMR experiments. The ¹H NMR titration in CD₃OD further confirmed that DHS-crown-6 (3) forms stable 1:1 complexes with KI, RbCl and CsCl, while it forms a 2:1 complex with KBPh₄. The results suggested that the 1:1 complex (3·MX) exchanges the metal ion with metal-free 3 through the formation of the 2:1 complex. The redox catalytic activity of 3 was evaluated using a selenoenzyme model reaction between H₂O₂ and dithiothreitol. The activity was significantly reduced in the presence of KCl due to the complex formation. Thus, the redox catalytic activity of DHS could be controlled by the conformational transition induced by coordination to an alkali metal ion. Full article

Conformative rehabilitation generally involves the treatment of partial dentate or the application of veneers. In this regard, conformative rehabilitation aims to generate an aesthetic prosthetic solution minimizing the amount of tissue removal without generating occlusal input interfering with the equilibrium of neuro-muscular function. In fact, pre-prosthetic orthodontics aims to re-establishing the correct position/inclination of the neighboring or antagonist teeth, providing appropriate space for the prosthetic crown. Clear aligners therapy (CAT) represents a valuable tool in the management of prosthetic cases with a conformative approach, as it allows clinicians to plan orthodontic movements that are guided by the prosthetic outcomes. In the present manuscript, we argue the concept of prosthetic guided orthodontics (PGO) by presenting and discussing three cases treated with the Invisalign GO system, which has been developed for the clinical management of multidisciplinary orthodontic-prosthetic cases with a conformative approach. In this regard, the rationale of this paper is to address the effectiveness and predictability of the digital set-up and CAT for aesthetic conformative rehabilitations. Full article

Double- and triple-decker lanthanide phthalocyaninates exhibit unique physical-chemical properties, particularly single-molecule magnetism. Among other factors, the magnetic properties of these sandwiches depend on their conformational state, which is determined via the skew angle of the phthalocyanine ligands. Thus, in the present work we report the comprehensive conformational study of substituted terbium(III) and yttrium(III) trisphthalocyaninates in solution depending on the substituents at the periphery of molecules, redox-states and nature of solvents. Conjunction of UV-vis-NIR spectroscopy and quantum-chemical calculations within simplified time-dependent DFT in Tamm–Dancoff approximation provided the spectroscopic signatures of staggered and gauche conformations of trisphthalocyaninates. Altogether, it allowed us to demonstrate that the butoxy-substituted complex behaves as a molecular switcher with controllable conformational state, while the crown-substituted triple-decker complex maintains a staggered conformation regardless of external factors. The analysis of noncovalent interactions within the reduced density gradient approach allowed to shed light on the nature of factors stabilizing certain conformers. Full article

In the 1580s and 1590s, the English state required that all subjects of the crown attend the Protestant state church. Those who refused (called recusants) faced imprisonment as part of the government’s attempt to bring them into religious conformity. Those imprisonments forced involuntary marital separation onto Catholic couples, the result of which was to disrupt traditional gender roles within Catholic households. Separated wives increasingly fulfilled the work their husbands performed in addition to their own responsibilities as the matriarch of a landed estate. Gentlewomen were practiced at estate business since they worked in partnership with their husbands, but a spouse’s imprisonment often meant that wives wrote more petitions and settled more legal and financial matters than they did when their husbands were at liberty. The state also imprisoned Catholic wives who undermined the religious conformity of their families and communities. Spousal imprisonment deprived couples of conjugal rights and spousal support and emphasized the state’s power to interfere in marital relationships in early modern England. Full article

Shrubs are an important part of the Gobi Desert ecosystem, and their aboveground biomass (AGB) is an important manifestation of the productivity of the Gobi Desert ecosystem. Characterizing the biophysical properties of low-stature vegetation such as shrubs in the Gobi Desert via conventional field surveys and satellite remote sensing images is challenging. The AGB of shrubs had been estimated from spectral variables taken from high-resolution images obtained by unmanned aerial vehicle (UAV) in the Gobi Desert, Xinjiang, China, using vegetation feature metrics. The main results were as follows: (1) Based on the UAV images, several RGB vegetation indices (RGB VIs) were selected to extract the vegetation coverage, and it was found that the excess green index (EXG) had the highest accuracy and the overall extraction accuracy of vegetation coverage reached 97.00%. (2) According to field sample plot surveys, the AGB and shrub crown area of single shrubs in the Gobi Desert were in line with a power model. From the bottom of the alluvial fan to the top of the alluvial fan, as the altitude increased, the AGB of the vegetation communities showed an increasing trend: the AGB of the vegetation communities at the bottom of the alluvial fan was 2–90 g/m², while that at the top of the alluvial fan was 60–201 g/m². (3) Vegetation coverage (based on the UAV image EXG index) and AGB showed a good correlation. The two conform to the relationship model (R² = 0.897) and the expression is Y = 1167.341 x^0.946, where Y is the AGB of the sample plots in units g/m² and x is the vegetation coverage extracted by the VI. (4) The predicted AGB values of Gobi Desert shrubs using UAV RGB images based on a power model were closer to the actual observed AGB values. The study findings provide a more efficient, accurate, and low-cost method for estimating vegetation coverage and AGB of Gobi Desert shrubs. Full article