Effects of Cognitive Load on Vocal Fold Vibratory Patterns in Bilingual Speakers of Low and High German.

Objectives: Increased cognitive load has been observed to correlate with decreased vocal fold perturbation, reduced additive noise, increased periodicity, and a higher rate of vocal fold vibration. The aim of this study was to explore whether vocal fold vibratory patterns can serve as indicators of increased cognitive load in nonbalanced bilingual speakers when they use their weaker language.

Study Design: This is a comparative experimental study with a within-speaker design.

L1 variation and L2 acquisition: L1 German /eː/-/ɛː/ overlap and its effect on the acquisition of L2 English /ɛ/-/æ/.

A person's first language (L1) affects the way they acquire speech in a second language (L2). However, we know relatively little about the role different varieties of the L1 play in the acquisition of L2 speech. This study focuses on German (L1) learners of English (L2) and asks whether the degree to which German speakers distinguish between the two vowels /eː/ and /ɛː/ in their L1 has an impact on how well these individuals identify /æ/ and discriminate between the two English vowels /ɛ/ and /æ/.

Coal-Tar Dye-based Coordination Cages and Helicates.

A strategy to implement four members of the classic coal-tar dye family, Michler's ketone, methylene blue, rhodamine B, and crystal violet, into [Pd L ] self-assemblies is introduced. Chromophores were incorporated into bis-monodentate ligands using piperazine linkers that allow to retain the auxochromic dialkyl amine functionalities required for intense colors deep in the visible spectrum. Upon palladium coordination, ligands with pyridine donors form lantern-shaped dinuclear cages while quinoline donors lead to strongly twisted [Pd L ] helicates in solution.

Interpenetrated Cage Structures.

This Review covers design strategies, synthetic challenges, host-guest chemistry, and functional properties of interlocked supramolecular cages. Some dynamic covalent organic structures are discussed, as are selected examples of interpenetration in metal-organic frameworks, but the main focus is on discrete coordination architectures, that is, metal-mediated dimers. Factors leading to interpenetration, such as geometry, flexibility and chemical makeup of the ligands, coordination environment, solvent effects, and selection of suitable counter anions and guest molecules, are discussed.

Light-Induced Charge Separation in Densely Packed Donor-Acceptor Coordination Cages.

Photon-powered charge separation is achieved in a supramolecular architecture based on the dense packing of functional building blocks. Therefore, self-assembled dimers of interpenetrated coordination cages consisting of redoxactive chromophors were synthesized in a single assembly step starting from easily accessible ligands and Pd(II) cations. Two backbones consisting of electron rich phenothiazine (PTZ) and electron deficient anthraquinone (ANQ) were used to assemble either homo-octameric or mixed-ligand double cages.

Fast skeletal myofibers of mdx mouse, model of Duchenne muscular dystrophy, express connexin hemichannels that lead to apoptosis.

Skeletal muscles of patients with Duchenne muscular dystrophy (DMD) show numerous alterations including inflammation, apoptosis, and necrosis of myofibers. However, the molecular mechanism that explains these changes remains largely unknown. Here, the involvement of hemichannels formed by connexins (Cx HCs) was evaluated in skeletal muscle of mdx mouse model of DMD.

SERS spectroscopic evidence for the integrity of surface-deposited self-assembled coordination cages.

A series of self-assembled coordination cages [Pd4L(n)8] based on a phenothiazine backbone has been investigated by means of Raman spectroscopy in solution and by Surface Enhanced Raman Scattering (SERS) on a nanostructured Au surface. The experiments demonstrate that the cages can be clearly distinguished from their constituting ligands by their Raman spectroscopic signatures. Furthermore, the structural integrity of the interpenetrated coordination cages upon deposition on the Au surface was demonstrated for the first time.

Narcissistic self-sorting vs. statistic ligand shuffling within a series of phenothiazine-based coordination cages.

Previously, we introduced a series of anion-binding interpenetrated double-cages based on phenothiazine and its mono- and di-S-oxygenated derivatives. Here, we complete the structural comparison of the three related assemblies by an X-ray single crystal analysis of the sulfone derivative. We further show that the three palladium cages coexist in solution upon post-assembly mixing due to the very slow ligand exchange whereas treatment of binary mixtures of the corresponding ligands with Pd(II) leads to the formation of mixed cages comprising a statistical ligand distribution.

De novo expression of connexin hemichannels in denervated fast skeletal muscles leads to atrophy.

Denervation of skeletal muscles induces atrophy, preceded by changes in sarcolemma permeability of causes not yet completely understood. Here, we show that denervation-induced Evans blue dye uptake in vivo of fast, but not slow, myofibers was acutely inhibited by connexin (Cx) hemichannel/pannexin1 (Panx1) channel and purinergic ionotropic P2X7 receptor (P2X7R) blockers. Denervated myofibers showed up-regulation of Panx1 and de novo expression of Cx39, Cx43, and Cx45 hemichannels as well as P2X7Rs and transient receptor potential subfamily V, member 2, channels, all of which are permeable to small molecules.

Relative anion binding affinity in a series of interpenetrated coordination cages.

Previously, we have reported on the quantitative self-assembly of a series of interpenetrated double-cages [Pd4Ligand8] with ligands based on various organic backbones. For dibenzosuberone-based cages it was shown that anion binding in the outer two pockets follows an allosteric mechanism. Herein we wish to report the anion binding capabilities of three related phenothiazine cages.

Assembly and stepwise oxidation of interpenetrated coordination cages based on phenothiazine.

A breath of fresh air is sufficient for the eightfold S-monooxygenation of an interpenetrated double cage based on eight phenothiazine ligands and four square-planar-coordinated Pd(II) cations. Besides these two cages, which were both characterized by X-ray crystallography, an eightfold S-dioxygenated double-cage was obtained under harsher oxidation conditions.

The ATP required for potentiation of skeletal muscle contraction is released via pannexin hemichannels.

During repetitive stimulation of skeletal muscle, extracellular ATP levels raise, activating purinergic receptors, increasing Ca2+ influx, and enhancing contractile force, a response called potentiation. We found that ATP appears to be released through pannexin1 hemichannels (Panx1 HCs). Immunocytochemical analyses and function were consistent with pannexin1 localization to T-tubules intercalated with dihydropyridine and ryanodine receptors in slow (soleus) and fast (extensor digitorum longus, EDL) muscles.

Deletion of the last five C-terminal amino acid residues of connexin43 leads to lethal ventricular arrhythmias in mice without affecting coupling via gap junction channels.

The cardiac intercalated disc harbors mechanical and electrical junctions as well as ion channel complexes mediating propagation of electrical impulses. Cardiac connexin43 (Cx43) co-localizes and interacts with several of the proteins located at intercalated discs in the ventricular myocardium. We have generated conditional Cx43D378stop mice lacking the last five C-terminal amino acid residues, representing a binding motif for zonula occludens protein-1 (ZO-1), and investigated the functional consequences of this mutation on cardiac physiology and morphology.

Connexin45 modulates the proliferation of transit-amplifying precursor cells in the mouse subventricular zone.

Connexins have been implicated in the regulation of precursor cell migration and proliferation during embryonic development of the mammalian brain. However, their function in postnatal neurogenesis is unclear. Here we demonstrate that connexin (Cx) 45 is expressed in transit-amplifying cells and neuroblasts in the postnatal subventricular zone (SVZ) and modulated the proliferation of SVZ-derived precursor cells in vivo.

Connexin45 provides optimal atrioventricular nodal conduction in the adult mouse heart.

Rationale: The gap junctional protein connexin (Cx) 45 is strongly expressed in the early embryonic myocardium. In the adult hearts of mice and humans, the expression mainly is restricted to the cardiac conduction system. Cx45 plays an essential role for development and function of the embryonic heart because general and cardiomyocyte-directed deficiencies of Cx45 in mice lead to embryonic lethality attributable to morphological and functional cardiovascular defects.

Residual Cx45 and its relationship to Cx43 in murine ventricular myocardium.

Gap junction channels in ventricular myocardium are required for electrical and metabolic coupling between cardiac myocytes and for normal cardiac pump function. Although much is known about expression patterns and remodeling of cardiac connexin(Cx)43, little is known about the less abundant Cx45, which is required for embryonic development and viability, is downregulated in adult hearts, and is pathophysiologically upregulated in human end-stage heart failure. We applied quantitative immunoblotting and immunoprecipitation to native myocardial extracts, immunogold electron microscopy to cardiac tissue and membrane sections, electrophysiological recordings to whole hearts, and high-resolution tandem mass spectrometry to Cx45 fusion protein, and developed two new tools, anti-Cx45 antisera and Cre(+);Cx45 floxed mice, to facilitate characterization of Cx45 in adult mammalian hearts.

Neuronal connexin-36 can functionally replace connexin-45 in mouse retina but not in the developing heart.

The gap junction protein connexin-45 (Cx45) is expressed in the conduction system of the heart and in certain neurons of the retina and brain. General and cardiomyocyte-directed deficiencies of Cx45 in mice lead to lethality on embryonic day 10.5 as a result of cardiovascular defects.