Search results for "Host"

Single-Molecule Spectroscopy of MEH-PPV Polymer Molecules in Different Host Matrices

2009

Fluorescence emission and excitation spectra of single MEH-PPV molecules dispersed in three different host polymers (PMMA, PS, and Zeonex) have been recorded at 1.2 K. We observed only minor effects of the host matrix on the following parameters: the ratios of single-chromophoric to multichromophoric emission, the widths of the distributions of emission maxima, and the (generally very low) fraction of emission spectra with sharp zero-phonon lines. The differences are tentatively attributed to different conformations of MEH-PPV chains, subtle variations in local chromophore−matrix interactions, and/or different distributions of conjugation lengths of emitting chromophores, respectively. Usin…

Hunting the plant surrender signal activating apoplexy in grapevines after Neofusicoccum parvum infection

2021

SummaryApoplectic breakdown from Grapevines Trunk Diseases (GTDs) has become a serious challenge to viticulture in consequence to drought stress. We hypothesise that fungal aggressiveness is controlled by a chemical communication between host and colonising fungus.We introduce the new concept of a “plant surrender signal” accumulating in host plants under stress and triggering aggressive behaviour of the strain Neofusicoccum parvum (Bt-67) causing Botryosphaeriaceae-related dieback in grapevines.Using a cell-based experimental system (Vitis cells) and bioactivity-guided fractionation, we identify trans-ferulic acid, a monolignol precursor, as “surrender signal”. We show that this signal spe…

Complexation Selectivities of Pillar[5]arenes with Primary Ammonium Salts

2013

The complexation of alkyl-substituted pillar[5]arenes with primary ammonium salts is investigated. 1,4-Bis(methoxy)pillar[5]arene (MeP5) can form strong complexes with the primary ammonium salts in CDCl3. However, 1,4-bis(ethoxy)pillar[5]arene (EtP5) shows weak interaction with these guests, and 1,4-bis(butoxy)pillar[5]arene (BuP5) can not form such a complex at all. These results indicate that the modified alkyl chains of pillar[5]arene play an important role in the complexation selectivity.

The Significance of Stilbene-Type Phytoalexin Degradation by Culture Filtrates of Botrytis Cinerea in the Vine-Botrytis Interaction

1993

Phytoalexins, antimicrobial compounds, synthesized by a plant in response to infection or a variety of stresses are known to be the most efficient way by which grapevines withstand an attack by Botrytis cinerea Pers., the causal organism for grey mould. In that plant, such responses include the production of a simple stilbene, resveratrol, and the biosynthetically related compounds, viniferins and pterostilbene. If stilbene-type phytoalexins represent a contributory factor in the resistance of grapevines to B.cinerea, the capacity of the pathogen to metabolize antifungal compounds released by the host could also play a significant role in the outcome of the interaction between grapevines an…

Cover Picture: Achieving Strong Positive Cooperativity through Activating Weak Non‐Covalent Interactions (Angew. Chem. Int. Ed. 3/2018)

2018

Selective recognition of aromatic hydrocarbons by endo-functionalized molecular tubes via C/N-H⋅⋅⋅π interactions

2018

Abstract Molecular recognition of aromatic hydrocarbons by four endo -functionalized molecular tubes has been studied by 1 H NMR spectroscopy, computational methods, and single crystal X-ray crystallography. The binding selectivity is rationalized by invoking shape complementarity and dipole alignment. The non-covalent interactions are proved to predominantly be C/N-H⋅⋅⋅ π interactions.

Resorcinarene Crowns ☆

2017

Resorcinarene crowns are a class of supramolecular hosts combining a crown ether moiety to a resorcinarene platform as either a podand arm, lower rim substituent, or a bridge. Resorcinarene crowns act as cation hosts and have therefore shown potential in ion transportation and in antibacterial applications.

Homocalixpyridines: Ligands Exhibiting High Selectivity in Extraction and Sensor Processes

1998

A novel spherical host architecture, based on pyridine subunits, has been created. It exhibits selective complexing properties toward soft metal ions (right), which have been tested in extraction and sensor processes. The complex-forming behaviour can be tailored by variation of the size of the cavity and by substitution. Homocalixpyridines are interesting in view of their application as selective carriers in separation and sensing techniques.

Hating Adolescents Test (HAT): a preliminary development of a measure to assess hating among adolescents

2020

The phenomenon of haters is becoming common among adolescents. The aims of the present research were to evaluate the preliminary psychometric properties of the Hating Adolescents Test (HAT), an ad hoc questionnaire created to evaluate online and offline hate (Study 1), and possible risk factors connected with hate (Study 2). Participants (202 female and 200 male) of this study completed the HAT, the How I Think Questionnaire, the Buss–Perry Aggression Questionnaire, and the Penn State Worry Questionnaire. Descriptive statistics were calculated, and exploratory factor analysis and confirmatory factor analysis were applied. Preliminary data suggest how males reported higher level of hate than…

Mandrel-less fabrication of biomimetic electrospun microfiber wires for tissue engineering applications

2021

This study introduces a novel mandrel-less electrodeposition method and a novel electrode prototypes useful for tissue engineering applications. More specifically, in this study a novel fabrication protocol to electrospun fibers-based chords, with length spanning from 2 cm to virtually no limitations on longitudinal length, is presented. For the first part of this study, Poly(ester urethane) urea (PEUU) was used to fabricate, by electrodeposition technique, continuous microfiber wires with controlled micro-architecture and tunable mechanics. A novel apparatus to process degradable or non-degradable polymers was used. Soft tissue injuries are common in daily clinical and surgical practice. O…