On the terminology of voice research

This article reviews problems associated with establishment of a scientifically accurate, internationally recognized, multilingual terminology to describe voice. Two strategies for developing terminology are discussed: consensus and dictation. Ontological decisions are considered an integral part of developing terminology. We conclude that terminological problems should be solved by a terminological committee—as yet to be established—as they average from problems in interpreting the literature and the results of voice research. A comprehensive bibliography and audio tape of the multilingual terminology describing voice would help facilitate adaptation and understanding of the terms defined.     

Changes in the Prevalence of Vocal Symptoms Among Teachers During a Twelve-Year Period

Vocal symptoms and voice disorders among teachers were studied in 1988 using a questionnaire designed to obtain information on six vocal symptoms that had appeared during the past 2 years. Twelve percent of the 478 respondents reported vocal symptoms occurring weekly or more often. The study was repeated using the same questionnaire in 2001. The results of this second study (n=241) indicate that vocal symptoms had increased considerably. Twenty-nine percent of the teachers reported symptoms occurring weekly or more often, and 20% reported two symptoms or more occurring at least once a week, which is significantly more than in 1988. Accordingly, voice disorders are probably a growing problem among teachers. Several factors may explain these increases. In 2001, the teachers complained more often about increases in the size of their classes. Factors that disturbed normal work routines, such as noisy or misbehaving pupils, had also increased significantly. A growing number of misbehaving pupils probably cause increased background noise and stress and, thus, increase the vocal symptoms in teachers.     

The 13C,H coupling constants in structural and conformational analysis. IV–The rotational dependence of the long-range CH couplings of the aldehyde and hydroxyl protons in salicylaldehyde

The proton-coupled ¹³C NMR spectrum of salicylaldehyde was analysed. The second-order character of the seven independent sub-spectra allowed the signs of most of the couplings to be determined. The input values for the analyses were obtained from the known J(CH) values of benzene, phenol and benzaldehyde using the additivity principle. In most instances, very good agreement between the calculated and observed values was obtained. Significant couplings of the ring carbons to both the aldehyde and hydroxyl protons were also observed. The magnitude of these couplings was very dependent on the stereochemical relationships between the coupled nuclei.     

Effect of wet spinning parameters on the properties of novel cellulosic fibres

Novel cellulose fibres (Biocelsol) were spun by traditional wet spinning technique from the alkaline solution prepared by dissolving enzyme treated pulp directly into aqueous sodium zincate (ZnO/NaOH). The spinning dope contained 6 wt.% of cellulose, 7.8 wt.% of sodium hydroxide (NaOH) and 0.84 wt.% of zinc oxide (ZnO). The fibres were spun into 5% and 15% sulphuric acid (H₂SO₄) baths containing 10% sodium sulphate (Na₂SO₄). The highest fibre tenacity obtained was 1.8 cNdtex⁻¹ with elongation of 15% and titre of 1.4 dtex. Average molecular weights and shape of molecular weight distribution curves of the celluloses from the novel wet spun cellulosic fibre and from the commercial viscose fibre were close to each other.     

Lanthanide DO3A-Complexes Bearing Peptide Substrates: The Effect of Peptidic Side Chains on Metal Coordination and Relaxivity

Two DO3A-type ligands conjugated to substrates of urokinase (L3) and caspase-3 (L4) via a propyl-amide linker were synthesized and their lanthanide(III) (Ln³⁺) complexes studied. A model compound without peptide substrate (L2) and an amine derivative ligand mimicking the state after enzymatic cleavage (L1) were also prepared. Proton Nuclear Magnetic Relaxation Dispersion (NMRD) profiles recorded on the gadolinium(III) (Gd³⁺) complexes, complemented with the assessment of hydration numbers via luminescence lifetime measurements on the Eu³⁺ analogues, allowed us to characterize the lanthanide coordination sphere in the chelates. These data suggest that the potential donor groups of the peptide side chains (carboxylate, amine) interfere in metal coordination, leading to non-hydrated LnL3 and LnL4 complexes. Nevertheless, GdL3 and GdL4 retain a relatively high relaxivity due to an important second-sphere contribution generated by the strongly hydrophilic peptide chain. Weak PARACEST effects are detected for the amine-derivative EuL1 and NdL1 chelates. Unfortunately, the GdL3 and GdL4 complexes are not significantly converted by the enzymes. The lack of enzymatic recognition of these complexes can likely be explained by the participation of donor groups from the peptide side chain in metal coordination.     

K-->pipi amplitudes from lattice QCD with a light charm quark

We compute the leading-order low-energy constants of the DeltaS=1 effective weak Hamiltonian in the quenched approximation of QCD with up, down, strange, and charm quarks degenerate and light. They are extracted by comparing the predictions of finite-volume chiral perturbation theory with lattice QCD computations of suitable correlation functions carried out with quark masses ranging from a few MeV up to half of the physical strange mass. We observe a DeltaI=1/2 enhancement in this corner of the parameter space of the theory. Although matching with the experimental result is not observed for the DeltaI=1/2 amplitude, our computation suggests large QCD contributions to the physical DeltaI=1/2 rule in the GIM limit, and represents the first step to quantify the role of the charm-quark mass in K-->pipi amplitudes. The use of fermions with an exact chiral symmetry is an essential ingredient in our computation.     

A Dinuclear Ruthenium‐Based Water Oxidation Catalyst: Use of Non‐Innocent Ligand Frameworks for Promoting Multi‐Electron Reactions

Insight into how H₂O is oxidized to O₂ is envisioned to facilitate the rational design of artificial water oxidation catalysts, which is a vital component in solar‐to‐fuel conversion schemes. Herein, we report on the mechanistic features associated with a dinuclear Ru‐based water oxidation catalyst. The catalytic action of the designed Ru complex was studied by the combined use of high‐resolution mass spectrometry, electrochemistry, and quantum chemical calculations. Based on the obtained results, it is suggested that the designed ligand scaffold in Ru complex 1 has a non‐innocent behavior, in which metal–ligand cooperation is an important part during the four‐electron oxidation of H₂O. This feature is vital for the observed catalytic efficiency and highlights that the preparation of catalysts housing non‐innocent molecular frameworks could be a general strategy for accessing efficient catalysts for activation of H₂O.     

An Oxofluoride Catalyst Comprised of Transition Metals and a Metalloid for Application in Water Oxidation

The application of the recently discovered oxofluoride solid solution (Co_xNi_1?x)₃Sb₄O₆F₆ as a catalyst for water oxidation is demonstrated. The phase exhibits a cubic arrangement of the active metal that forms oxo bridges to the metalloid with possible catalytic participation. The Co₃Sb₄O₆F₆ compound proved to be capable of catalyzing 2H₂O→O₂+4H⁺+4e^? at 0.33 V electrochemical and ≤0.39 V chemical overpotential with a TOF of 4.4?10^?3, whereas Ni₃Sb₄O₆F₆ needs a higher overpotential. Relatively large crystal cubes (0.3–0.5 mm) are easily synthesized and readily handled as they demonstrate both chemical resistance to wear after repeated in situ tests under experimental conditions, and have a mechanical hardness of 270 V0.1 using Vickers indentation. The combined properties of this compound offer a potential technical advantage for incorporation to a catalytic interface in future sustainable fuel production.     

Hybrid Supramolecular and Colloidal Hydrogels that Bridge Multiple Length Scales

Hybrid nanocomposites were constructed based on colloidal nanofibrillar hydrogels with interpenetrating supramolecular hydrogels, displaying enhanced rheological yield strain and a synergistic improvement in storage modulus. The supramolecular hydrogel consists of naphthyl‐functionalized hydroxyethyl cellulose and a cationic polystyrene derivative decorated with methylviologen moieties, physically cross‐linked with cucurbit[8]uril macrocyclic hosts. Fast exchange kinetics within the supramolecular system are enabled by reversible cross‐linking through the binding of the naphthyl and viologen guests. The colloidal hydrogel consists of nanofibrillated cellulose that combines a mechanically strong nanofiber skeleton with a lateral fibrillar diameter of a few nanometers. The two networks interact through hydroxyethyl cellulose adsorption to the nanofibrillated cellulose surfaces. This work shows methods to bridge the length scales of molecular and colloidal hybrid hydrogels, resulting in synergy between reinforcement and dynamics.