Chronic Electro-Acoustic Stimulation May Interfere With Electric Threshold Recovery After Cochlear Implantation in the Aged Guinea Pig.

Objectives: Electro-acoustic stimulation (EAS) combines electric stimulation via a cochlear implant (CI) with residual low-frequency acoustic hearing, with benefits for music appreciation and speech perception in noise. However, many EAS CI users lose residual acoustic hearing, reducing this benefit. The main objectives of this study were to determine whether chronic EAS leads to more hearing loss compared with CI surgery alone in an aged guinea pig model, and to assess the relationship of any hearing loss to histology measures.

Hybrid Cu-Containing Compounds Based on Lacunary Strandberg Anions: Synthesis under Mild Conditions, Crystal Structure, and Magnetic Properties.

A one-pot reaction of a copper source (metallic powder Cu or Cu salts) and bpy (bpy = 2,2'-bipyridine) in the presence of (NH)HPO and (NH)MoO·4HO yields heterometallic hybrid compounds of the general type {[Cu(bpy)(HO)][PMoO]}. The structures exhibit a number of phosphomolybdate POMs including not only a common Strandberg anion [PMoO] but also its unprecedented bi- and trilacunary derivatives [PMoO] and [PMoO]. The structural determinants including the metal source (copper powder copper salts), counterion of the salts, and stoichiometry of the reagents were examined.

Crystal structure of bis-(μ--hy-droxy-picolin-amid-ato)bis-[bis-(-hy-droxy-picolinamide)-sodium].

The title compound, [Na(CHNO)(CHNO)], is a centrosymmetric coordination dimer based on the sodium(I) salt of -hy-droxy-picolinamide. The mol-ecule has an {NaO(μ-O)} core with two bridging carbonyl O atoms and two hydroxamate O atoms of two mono-deprotonated residues of -hy-droxy-picolinamide, while two neutral -hy-droxy-picolinamide mol-ecules are coordinated in a monodentate manner to each sodium ion the carbonyl O atoms [the Na-O distances range from 2.3044 (2) to 2.

Crystal structure of bis-(bis-{μ-3-methyl-3-[(4-nitro-2-oxido-benzyl-idene)amino]-propane-1,3-diolato}tris-[chlorido-(dimethyl sulfoxide)-iron(III)]) dimethyl sulfoxide hepta-solvate dihydrate.

The title compound, [Fe(CHNO)Cl(CHOS)]·7CHOS·2HO, was isolated accidentally from an Fe-NiCl·6HO-H-TEA-DMSO system [where H is the product of the condensation between -nitro-salicyl-aldehyde and 2-amino-2-methyl-propane-1,3-diol and dimethyl sulfoxide (DMSO), and TEA is triethylamine]. The structure is based on a trinuclear {Fe(μ-O)} core, with an angular arrangement of the Fe ions that can be explained by the geometrical restrictions of two bulky ligands, each coordinating to all of the metal cations.

Crystal structure of tetra-kis-[μ2-2-(di-methyl-amino)-ethano-lato-κ(3) N,O:O]di-μ3-hydroxido-di-thio-cyanato-κ(2) N-dichromium(III)dilead(II) di-thio-cyanate aceto-nitrile monosolvate.

The tetra-nuclear complex cation of the title compound, [Cr2Pb2(NCS)2(OH)2(C4H10NO)4](SCN)2·CH3CN, lies on an inversion centre. The main structural feature of the cation is a distorted seco-norcubane Pb2Cr2O6 cage with a central four-membered Cr2O2 ring. The Cr(III) ion is coordinated in a distorted octa-hedron, which involves two N atoms of one bidentate ligand and one thio-cyanate anion, two μ2-O atoms of 2-(di-methyl-amino)-ethano-late ligands and two μ3-O atoms of hydroxide ions.

Crystal structure of bis-(ethyl-enedi-thio)-tetra-thia-fulvalenium μ2-acetato-bis-[tri-bromido-rhenate(III)] 1,1,2-tri-chloro-ethane hemisolvate.

The asymmetric unit of the title salt, (C10H8S8)[Re2Br6(CH3COO)]·0.5C2H3Cl3, contains one bis-(ethyl-enedi-thio)-tetra-thia-fulvalene (ET) radical cation, one μ2-acetato-bis-[tri-bromido-rhenate(III)] anion and a 1,1,2-tri-chloro-ethane mol-ecule with half-occupancy disordered about a twofold rotation axis. The tetra-thia-fulvalene fragment adopts an almost planar configuration typical of the ET radical cation.

Crystal structure of N-hy-droxy-picolinamide monohydrate.

The crystal structure of the title compound, C6H6N2O2·H2O, consists of N-hy-droxy-picolinamide and water mol-ecules connected through O-H⋯O and N-H⋯N hydrogen bonds. The O-H⋯O inter-actions and π-π stacking inter-actions between the pyridine rings [centroid-centroid distance = 3.427 (1) Å] organize the components into columns extending along the b axis and the N-H⋯N hydrogen bonds link these columns into a two-dimensional framework parallel to (100).

Optogenetic Control of Mouse Outer Hair Cells.

Normal hearing in mammals depends on sound amplification by outer hair cells (OHCs) presumably by their somatic motility and force production. However, the role of OHC force production in cochlear amplification and frequency tuning are not yet fully understood. Currently, available OHC manipulation techniques for physiological or clinical studies are limited by their invasive nature, lack of precision, and poor temporal-spatial resolution.

Direct Intracochlear Acoustic Stimulation Using a PZT Microactuator.

Combined electric and acoustic stimulation has proven to be an effective strategy to improve hearing in some cochlear implant users. We describe an acoustic microactuator to directly deliver stimuli to the perilymph in the scala tympani. The 800 µm by 800 µm actuator has a silicon diaphragm driven by a piezoelectric thin film (e.

A self-assembled octanuclear complex bearing the uncommon close-packed {Fe4Mn4(μ4-O)4(μ-O)4} molecular core.

A one-pot open-air reaction of manganese powder with iron(ii) chloride in DMF solution of the Schiff base (H2L) formed in situ from salicylaldehyde and hydroxylamine hydrochloride yields the heterometallic complex [Fe4(μ4-O)4Mn4(L)8(DMF)4]·2DMF (). Single crystal X-ray analysis shows that its molecular structure is based on the octanuclear core {Fe4Mn4(μ4-O)4(μ-O)4} with a quite rare molecular structure type {M8(μ4-X)4(μ-X)4}, where the central cube-like iron motif is modified with four terminal manganese fragments, the whole core being presented as the {Fe4(μ4-O)4} + 4{Mn(μ-O)} combination. Using the data from the Cambridge Structural Database (CSD), an analysis of the octanuclear structures with similar central {M4(μ4-X)4} fragments was performed.

Ionization and tautomerism of methyl fluorescein and related dyes.

The protolytic equilibrium of methyl ether of fluorescein is studied in water, aqueous ethanol, and in other solvents. The constants of the two-step dissociation are determined by spectrophotometry. In water, the fractions of the zwitterionic, quinonoid, and lactonic tautomes are correspondingly 11%, 6%, and 83%, as deduced from the UV-visible spectra.

Direct synthesis of a {Co₆(III)Fe₆(III)} dodecanuclear complex, revealing an unprecedented molecular structure type.

A novel heterometallic Co6Fe6 Schiff base complex, possessing an unprecedented {M12(μ-X)22} branched structure (according to the search via the Cambridge Structural Database), has been prepared using the "direct synthesis" approach and characterized by single crystal X-ray diffraction and magnetometry.

Crystal structure of {2-[({2-[(2-amino-eth-yl)amino]-eth-yl}imino)-meth-yl]pheno-lato}aqua-copper(II) bromide.

In the mononuclear copper(II) title complex, [Cu(C11H16N3O)(H2O)]Br, the Cu(II) atom is coordinated by one O and three N atoms of the Schiff base ligand that forms together with one water mol-ecule a slightly distorted [CuN3O2] square-pyramidal polyhedron. The deviation of the Cu(II) atom from the mean equatorial plane is 0.182 (2) Å.

JAK2/STAT3 inhibition attenuates noise-induced hearing loss.

Signal transducers and activators of transcription 3 (STAT3) is a stress responsive transcription factor that plays a key role in oxidative stress-mediated tissue injury. As reactive oxygen species (ROS) are a known source of damage to tissues of the inner ear following loud sound exposure, we examined the role of the Janus kinase 2 (JAK2)/STAT3 signaling pathway in noise induce hearing loss using the pathway specific inhibitor, JSI-124. Mice were exposed to a moderately damaging level of loud sound revealing the phosphorylation of STAT3 tyrosine 705 residues and nuclear localization in many cell types in the inner ear including the marginal cells of the stria vascularis, type II, III, and IV fibrocytes, spiral ganglion cells, and in the inner hair cells.

Tetra-kis(μ3-2-{[1,1-bis-(hy-droxy-meth-yl)-2-oxidoeth-yl]imino-meth-yl}-6-nitro-pheno-lato)tetra-copper(II).

The title cluster, [Cu4(C11H12N2O6)4], was obtained from the Cu(0)-FeCl2·4H2O-H4 L-Et3N-DMF reaction system (in air), where H4 L is 2-hy-droxy-methyl-2{[(2-hy-droxy-3-nitro-phen-yl)methyl-idene]amino}-propane-1,3-diol and DMF is di-methyl-formamide. The asymmetric unit consists of one Cu(2+) ion and one dianionic ligand; a -4 symmetry element generates the cluster, which contains a {Cu4O4} cubane-like core. The metal ion has an elongated square-based pyramidal CuNO4 coordination geometry with the N atom in a basal site.

Magnetic, high-field EPR studies and catalytic activity of Schiff base tetranuclear CuII2FeIII2 complexes obtained by direct synthesis.

Two novel heterometallic complexes [Cu2Fe2(HL(1))2(H2L(1))2]·10DMSO (1) and [Cu2Fe2(HL(2))2(H2L(2))2]·2DMF (2) have been prepared using the open-air reaction of copper powder, iron(II) chloride and DMSO (1) or DMF (2) solutions of the polydentate Schiff base (H4L(1), 1; H4L(2), 2) formed in situ from salicylaldehyde (1) or 5-bromo-salicylaldehyde (2) and tris(hydroxymethyl)aminomethane. Crystallographic analysis revealed that both compounds are based on the centrosymmetric tetranuclear core {Cu(II)2Fe(III)2(μ-O)6} where metal centres are joined by μ-O bridges from the deprotonated ligands forming a nonlinear chain-like arrangement. Variable-temperature (1.

catena-Poly[[manganese(III)-bis-{μ-2-[(2-hy-droxy-eth-yl)imino-meth-yl]-6-meth-oxy-phenolato-κ(3) O (1),N:O (2);κ(3) O (2):N,O (1)}] iodide].

In the title one-dimensional coordination polymer, {[Mn(C10H12NO3)2]I} n , the potentially tetra-dentate (O,O,O,N) 2-[(2-hy-droxy-eth-yl)imino-meth-yl]-6-meth-oxy-phenol (H2 L) ligands are mono-deprotonated (as HL (-)) and coordinated by the metal ions in a tridentate chelate-bridging fashion [2.0111112]. The Mn(III) atom possesses a distorted trans-MnO4N2 octa-hedral coordination environment.

Entropy versus aromaticity in the conformational dynamics of aromatic rings.

Comparison of the results of Car-Parrinello molecular dynamics simulations of isolated benzene, pyrimidine and 1,2,4-triazine molecules reveals that the unusually low population of planar geometry of the benzene ring is caused by entropy effects despite its high aromaticity. The decrease in symmetry of the molecule results in smaller changes in entropy and Gibbs free energy due to out-of-plane deformations of the ring, leading to an increase in the population of planar geometry of the ring. This leads to differences in the topology of potential energy and Gibbs free energy surfaces.

Bis(2-hy-droxy-imino-methyl-6-meth-oxy-phenolato-κ(2)N,O(1))copper(II).

In the title compound, [Cu(C(8)H(8)NO(3))(2)], the nearly planar mol-ecule (r.m.s.

Hexa-kis-(dimethyl-formamide-κO)manganese(II) (dimethyl-formamide-κO)pentakis(-thio-cyanato--κN)chromate(III).

The title compound, [Mn(C(3)H(7)NO)(6)][Cr(NCS)(5)(C(3)H(7)NO)], was obtained unintentionally as a product of an attempted synthesis of heterometallic complexes based on Reineckes anion using manganese powder, Reineckes salt and 1-(2-hy-droxy-eth-yl)tetra-zole as starting materials. The crystal structure of the complex consists of an [Mn(dmf)(6)](2+) cation and a [Cr(NCS)(5)(dmf)](2-) anion (dmf = dimethyl-formamide). The Mn(II) and Cr(III) atoms show a slightly distorted octa-hedral MnO(6) and CrN(5)O coordination geometries with adjacent angles in the range 85.

Tris(2,2'-bipyridine-κN,N')cobalt(III) tris-(oxalato-κO,O)ferrate(III) mono-hydrate.

The title compound, [Co(C(10)H(8)N(2))(3)][Fe(C(2)O(4))(3)]·H(2)O, con-sists of two discrete tris-(chelate) metal ions (Co(III)N(6) and Fe(III)O(6) chromophores) and a water mol-ecule. The structure is highly symmetrical; the Co(III) and Fe(III) ions occupy positions with site symmetry 3.2.

Hexa-kis-(dimethyl-formamide-κO)manganese(II) μ-oxido-bis-[trichlorido-ferrate(III)].

The title compound, [Mn(C(3)H(7)NO)(6)][Fe(2)Cl(6)O], was obtained unintentionally as a product of an attempted synthesis of heterometallic complexes with Schiff base ligands using manganese powder and FeCl(3)·6H(2)O as starting materials. In the [Fe(2)OCl(6)](2-) anion, the O atom and the Fe atom occupy positions with site symmetry [Formula: see text] and 3, respectively, resulting in a linear Fe-O-Fe angle and a staggered conformation. The octa-hedrally surrounded cation (site symmetry [Formula: see text]) and the [Fe(2)Cl(6)O](2-) anion are alternately stacked along [001].

Aromaticity in heterocyclic analogues of benzene: comprehensive analysis of structural aspects, electron delocalization and magnetic characteristics.

The degree of aromaticity of six-membered monoheterocycles with IV-VI group heteroatoms (C(6)H(5)X, where X = SiH, GeH, N, P, As, O(+), S(+), Se(+)) was analyzed using the results of ab initio calculations at the MP2/cc-pvtz level. Values of common aromaticity indices including those based on electronic delocalization properties, structural-dynamic features and magnetic properties all indicate high aromaticity of all considered heterocycles. A decrease in aromaticity is observed with increasing atomic number of the heteroatom, except in the case of the pyrylium cation.

Na+/K+-ATPase α1 identified as an abundant protein in the blood-labyrinth barrier that plays an essential role in the barrier integrity.

Background: The endothelial-blood/tissue barrier is critical for maintaining tissue homeostasis. The ear harbors a unique endothelial-blood/tissue barrier which we term "blood-labyrinth-barrier". This barrier is critical for maintaining inner ear homeostasis.

Bone marrow cell recruitment mediated by inducible nitric oxide synthase/stromal cell-derived factor-1alpha signaling repairs the acoustically damaged cochlear blood-labyrinth barrier.

Using a mouse model with noise-induced cochlear blood-labyrinth-barrier (CBLB) injury, we examined the effects of inducible nitric oxide synthase (iNOS) on the recruitment of bone marrow-derived cells (BMDCs) to the CBLB after acoustic injury. Lethally irradiated C57BL/6J and B6.129P2-Nos2(tm1Lau)/J mice were transplanted with GFP(+)-BMDCs from C57Bl/6-Tg (UBC GFP) mice.