Evolution of linear absorption and nonlinear optical properties in V-shaped ruthenium(II)-based chromophores.

In this article, we describe a series of complexes with electron-rich cis-{Ru(II)(NH(3))(4)}(2+) centers coordinated to two pyridyl ligands bearing N-methyl/arylpyridinium electron-acceptor groups. These V-shaped dipolar species are new, extended members of a class of chromophores first reported by us (Coe, B. J. et al. J. Am. Chem. Soc. 2005, 127, 4845-4859). They have been isolated as their PF(6)(-) salts and characterized by using various techniques including (1)H NMR and electronic absorption spectroscopies and cyclic voltammetry. Reversible Ru(III/II) waves show that the new complexes are potentially redox-switchable chromophores. Single crystal X-ray structures have been obtained for four complex salts; three of these crystallize noncentrosymmetrically, but with the individual molecular dipoles aligned largely antiparallel. Very large molecular first hyperpolarizabilities beta have been determined by using hyper-Rayleigh scattering (HRS) with an 800 nm laser and also via Stark (electroabsorption) spectroscopic studies on the intense, visible d --> pi* metal-to-ligand charge-transfer (MLCT) and pi --> pi* intraligand charge-transfer (ILCT) bands. The latter measurements afford total nonresonant beta(0) responses as high as ca. 600 x 10(-30) esu. These pseudo-C(2v) chromophores show two substantial components of the beta tensor, beta(zzz) and beta(zyy), although the relative significance of these varies with the physical method applied. According to HRS, beta(zzz) dominates in all cases, whereas the Stark analyses indicate that beta(zyy) is dominant in the shorter chromophores, but beta(zzz) and beta(zyy) are similar for the extended species. In contrast, finite field calculations predict that beta(zyy) is always the major component. Time-dependent density functional theory calculations predict increasing ILCT character for the nominally MLCT transitions and accompanying blue-shifts of the visible absorptions, as the ligand pi-systems are extended. Such unusual behavior has also been observed with related 1D complexes (Coe, B. J. et al. J. Am. Chem. Soc. 2004, 126, 3880-3891).

Nonlinear optical and related properties of iron(II) pentacyanide complexes with quaternary nitrogen electron acceptor units.

Three new complex salts Na(2)[Fe(II)(CN)(5)(L)] [L = N-methyl-4-{E,E-4-(4-pyridyl)buta-1,3-dienyl}pyridinium, N-methyl-4-{E,E,E-6-(4-pyridyl)hexa-1,3,5-trienyl}pyridinium, or N-methyl-1,4-bis-{E-2-(4-pyridyl)ethenyl}] benzene have been prepared. These compounds have been characterized by using various techniques including electronic absorption spectroscopy and cyclic voltammetry, allowing their properties to be compared with those of the known complexes where L = N-methylpyrazinium (Mepyz(+)), N-methyl-4,4'-bipyridinium, or N-methyl-4-[E-2-(4-pyridyl)ethenyl]pyridinium. Molecular quadratic nonlinear optical (NLO) responses have been determined by using hyper-Rayleigh scattering (HRS) at 1064 nm, and also via Stark (electroabsorption) spectroscopic studies on the intense, visible d --> pi* metal-to-ligand charge-transfer (MLCT) bands. The MLCT transitions show large red-shifts on moving from aqueous to methanol solutions, and these excitations are associated with relatively large static first hyperpolarizabilities beta(0). Single crystal X-ray structures of two hydrated materials containing the complex anion [Fe(II)(CN)(5)(Mepyz(+))](2-) have been determined, and both of these show some degree of alignment of the constituent complex dipoles.

Neuromuscular electrical stimulation improves feeding and aspiration status in medically complex children undergoing feeding therapy.

OBJECTIVES: Neuromuscular electrical stimulation (NMES) therapy in the head and neck has been effectively used to rehabilitate swallowing in adult patients with acquired dysphagia. Limited data is available for the effectiveness of NMES in medically complex children with dysphagia and aspiration. This study intends to determine the efficacy of NMES as a therapeutic adjunct to improve aspiration and feeding status in medically complex children with severe dysphagia undergoing comprehensive speech and swallow therapy. STUDY DESIGN: Case series. SETTING: Tertiary children's hospital. SUBJECTS: and Methods: Medically complex children undergoing treatment for dysphagia using NMES during a three year period were included. Duration of treatment routinely ranged from 20 to 26 weeks. Demographic information, pre and post-NMES treatment aspiration status via modified barium swallow (MBS), and pre and post-NMES treatment feeding status were examined. RESULTS: 15 medically complex children underwent NMES as a component of their feeding therapy. The mean age was 2.51 ±â€¯3.20 years. Mean pre-treatment Functional Oral Intake Scale(FOIS) was 3.07 ±â€¯1.94. Following NMES, FOIS improved to 4.47 ±â€¯2.26 (p < 0.0001). Fourteen patients were evaluated with MBS prior to NMES. Pre-treatment aspiration and penetration were noted in 10 and 2 patients respectively. Two patients did not aspirate on pre-treatment MBS. Improvement was noted in 9 of 11 children with post-treatment MBS. CONCLUSION: NMES was safely completed in all children without complication. Improvement in aspiration status was seen in 83.3% of patients with pre- and post-treatment MBS. Feeding status as measured by textures was advanced in all patients with a significant improvement in FOIS. Future prospective studies are required to investigate the specific role in children with acquired and congenital dysphagia.

Endoscopic cricopharyngeal myotomy in infants.

Cricopharyngeal achalasia is a rare cause of dysphagia in young children. Conservative treatments involve medical therapy and serial dilations or injections. Definitive cure can be achieved with cricopharyngeal myotomy. We report two cases of young children, each less than one year of age, who underwent endoscopic laser-assisted cricopharyngeal myotomy. Following surgery, both infants were able to advance to age appropriate diets prior to discharge. Post-operative modified barium swallow demonstrated complete resolution of achalasia in both patients. To the best of our knowledge, this is the first case series of infants undergoing successful endoscopic cricopharyngeal myotomy.

The roles of marriage and anger dysregulation in biobehavioral stress responses.

Physiological and behavioral correlates of anger dysregulation in adults were evaluated in the context of marital stress. Fifty-four married couples participated in a series of laboratory procedures that included electrocardiogram measures during a 15-min marital conflict interaction and an interview assessing their inability to regulate anger (anger dysregulation). Results from the multivariate regression analyses indicated that the nature of the couple's relationship, rather than individual levels of anger dysregulation, predicted lower parasympathetic cardiac activity (indexed by high-frequency heart period variability) and shorter cardiac interbeat intervals. Anger dysregulation, rather than the dyadic relationship, was predictive of greater displays of angry behavior during the marital conflict interaction. The importance of contextual factors in stress processes, such as stress due to marriage, are discussed in light of research linking poor marital quality to greater health risks for women than for men.

Observing gay, lesbian and heterosexual couples' relationships: mathematical modeling of conflict interaction.

Two samples of committed gay and lesbian cohabiting couples and two samples of married couples (couples in which the woman presented the conflict issue to the man, and couples in which the man presented the conflict issue to the woman) engaged in three conversations: (1) an events of the day conversation (after being apart for at least 8 hours), (2) a conflict resolution conversation, and (3) a pleasant topic conversation. The observational data were coded with a system that categorized specific affects displayed. Data were weighted and two time-series created, one for the husband and one of the wife. The time series were modeled with nonlinear difference equations (Cook et al., 1995), and parameters were estimated that indexed uninfluenced steady state, influenced steady state, emotional inertia, repair effectiveness and threshold, and the power of positive and negative affect of one partner to affect the other partner.