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61.
Redox reaction between 6-acetonylisoxanthopterin (H2pte) and [MoVIO2 (ssp)] [ssp = anion of 2-(salicylideneamino) benzenethiol] in CH3OH-C2H5OH medium produces a new mixed ligand compound [MoIV (ssp) (Hpte) (OCH3)] (1). It has been characterized by elemental analysis, ESMS data, UV-Vis, IR,1HNMR (1D and 2D) spectroscopy and cyclic voltammetry. Kinetics of formation of this compound as well as that of its reaction
with pyridine N-oxide have been followed spectrophotometrically. Both the reactions follow substrate saturation kinetics and
involve metal-centred oxygen atom transfer process. Large negative values of entropy of activation indicate the operation
of associative mechanism. 相似文献
62.
63.
64.
Andreu R Galán E Orduna J Villacampa B Alicante R Navarrete JT Casado J Garín J 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(3):826-838
Push–pull compounds, in which a proaromatic electron donor is conjugated to a 2‐dicyanomethylenethiazole acceptor, have been prepared, and their properties compared to those of model compounds featuring an aromatic donor. A combined experimental (X‐ray diffraction, 1H NMR, IR, Raman, UV/Vis, nonlinear optical (NLO) measurements) and theoretical study reveals that structural and solvent effects determine the ground‐state polarisation of these merocyanines: whereas 4H‐pyran‐4‐ylidene‐ and 4‐pyridylidene‐containing compounds are zwitterionic and 1,3‐dithiol‐2‐ylidene derivatives are close to the cyanine limit, anilino‐derived merocyanines are essentially neutral. This very large range of intramolecular charge transfer (ICT) gives rise to efficient second‐order NLO chromophores with μβ values ranging from strongly negative to strongly positive. In particular, pyranylidene derivatives are unusual in that they show an increase in the degree of ICT on lengthening the π‐spacer, a feature that lies behind the very large negative μβ values they display. The linking of the formally quinoidal 2‐dicyanomethylenethiazole moiety to proaromatic donors seems a promising approach towards the optimisation of zwitterionic NLO chromophores. 相似文献
65.
Steven Bielamowicz MD Sheila V. Stager Andrea Badillo Alexis Godlewski 《Journal of voice》2002,16(1):117-123
Both unilateral and bilateral thyroarytenoid muscle injections of Botox provide effective management of voice symptoms in patients with adductor spasmodic dysphonia; however, the preferred injection technique has not been established. In this study, 16 patients were treated with unilateral injections (72 injections total) and 33 patients were managed with bilateral injections (133 injections total). Individual assignments to injection type were based on treatment previously received and dose was adjusted according to the patient's previous treatment response. An optimal treatment included a benefit lasting 3 months or more with side effects lasting 2 weeks or less. Compared to patients receiving bilateral injections, those receiving unilateral injections more frequently noted a benefit of 3 months or more (p = 0.03), side effects of 2 weeks or less duration (p = 0.03), as well as both a 3-month benefit and a 2-week or less side effect (p = 0.0004). Injection type had no effect on optimal Botox dosing with repeat injections. Successive unilateral injections at the same dose were more likely (p = 0.012) than successive bilateral injections to produce the same or longer duration of benefit. We conclude that a unilateral injection routine has a more optimal and consistent treatment effect/side effect profile. 相似文献
66.
Yolanda D. Heman-Ackah MD Deirdre D. Michael George S. Goding Jr. 《Journal of voice》2002,16(1):20-27
Traditional measures of dysphonia vary in their reliability and in their correlations with perceptions of grade. Measurements of cepstral peak prominence (CPP) have been shown to correlate well with perceptions of breathiness. Because it is a measure of periodicity, CPP should also predict roughness. The ability of CPP and other acoustic measures to predict overall dysphonia and the subcategories of breathiness and roughness in pathological voice samples is explored. Preoperative and postoperative speech samples from 19 patients with unilateral recurrent laryngeal nerve paralysis who underwent operative intervention were analyzed by trained listeners and by measures of smoothed CPP (CPPS), noise-to-harmonic ratio (NHR), amplitude perturbation quotient (APQ), relative average perturbation (RAP), and smoothed pitch perturbation quotient (sPPQ). The data were analyzed with bivariate Pearson correlation statistics. Grade of dysphonia and breathiness ratings correlated better with measurements of CPPS than with the other measures. CPPS from samples of connected speech (CPPS-s) best predicted overall dysphonia. None of the measures were useful in predicting roughness. 相似文献
67.
Jane Yang Nicole Maronian Victoria Reyes Pat Waugh Teresa Brentnall Allen Hillel MD 《Journal of voice》2002,16(2):278-282
Laryngeal and other otolaryngologic manifestations of Crohn's disease are uncommon and may be subtle. Crohn's disease is a well-known inflammatory bowel disease of unknown etiology marked by relapsing and remitting granulomatous inflammation of the alimentary tract. Extraintestinal manifestations of Crohn's disease may appear anytime during the course of the disease process and may be the initial symptom. Findings are nonspecific, primarily edema and ulcerations, and may be confused with a multitude of other disease processes. Awareness of these manifestations in the head and neck will prevent misdiagnosis or a delay in diagnosis. 相似文献
68.
Kyung Sook Kim MD. Shakilur Rahman Manwoo Lee Guinyun Kim Pham Duc Khue Nguyen Van Do Moo-Hyun Cho In Soo Ko Won Namkung H. Naik Tae-Ik Ro 《Journal of Radioanalytical and Nuclear Chemistry》2011,287(3):869-877
We measured the isomeric yield ratios for the photonuclear reactions of 93Nb(??,4n)89m,gNb and natMo(??,xnp)95m,gNb by using the activation method. The high-purity 93Nb and natMo metallic foils in disc shape were irradiated with uncollimated bremsstrahlung beams of 50-, 60-, and 70-MeV generated from an electron linear accelerator in Pohang Accelerator Laboratory. The induced activities in the irradiated foils were measured by the high-resolution ??-ray spectrometry with a calibrated high-purity Germanium (HPGe) detector coupled to a PC-based 4?K multichannel analyzer. The reaction 93Nb(??,4n)89m,gNb was studied for the first time which has no comparable literature data. The result of 95m,gNb isomeric pair was measured based on (??,p), (??,np), and (??,2np) reactions which is the first measurement at the intermediate energy region of 50?C70-MeV with a natMo target. 相似文献
69.
Rodríguez C. A. Delgadillo A. Núñez J. Cabello-Guzmán G. Mera Adriana C. Delplancke M. P. Villacampa B. Carrasco C. 《Journal of Solid State Electrochemistry》2020,24(6):1405-1414
Journal of Solid State Electrochemistry - A one-step electrodeposition process was used to obtain CuInS2 (CIS) films on a molybdenum substrate by varying the supporting electrolyte (lithium... 相似文献
70.
Fluoropolymer blends have been widely used as binders for exterior coatings because of their excellent resistance to ultra-violet (UV) radiation as well as to many corrosive chemical agents.It is known that the fluorinated component usually has a lower glass transition temperature and easily crystallizes in the final structure depending upon the blend composition and sample annealing condition.We investigated the effect of blend composition and annealing process (slow and fast cooling) on the surface mor... 相似文献