(2+1) Resonance Enhanced Ionization Spectroscopy of a State Selected Beam of OH Radicals

A state-selected beam of hydroxyl radicals is generated using a pulsed discharge source and hexapole field. The OH radicals are characterized by resonance-enhanced multiphoton ionization (REMPI) spectroscopy via the nested D  and 3  Rydberg states. Simplified spectra are observed from the selected ∣MJ∣ = 3/2 component of the upper Λ-doublet level of the lowest rotational state (J = 3/2) in ground (v″ = 0) and excited(v″ = 1–3) vibrational levels of the OH X  state. Two-photon transitions are observed to the D (v′ = 0–3) and 3 (v′ = 0,1) vibronic levels, extending previous studies to higher vibrational levels of the Rydberg states. Spectroscopic constants are derived for the Rydberg states and compared with prior experimental studies. Complementary first-principle theoretical studies of the D  and 3  Rydberg states [see M. P. J. van der Loo and G. C. Groenenboom, J. Chem. Phys. 123, 074310 (2005), following paper ] are used to interpret the experimental findings and examine the utility of the (2+1) REMPI scheme for sensitive detection of OH radicals

Photodissociation of the OD radical at 226 and 243 nm

The photodissociation dynamics of state selected OD radicals has been examined at 243 and 226 nm using velocity map imaging to probe the angle–speed distributions of theD(2S) and O(3P2) products. Both experiment and complementary first principle calculations demonstrate that photodissociation occurs by promotion of OD from high vibrational levels of the ground X 2Π state to the repulsive 1 2Σ− state

(2 + 1) RESONANCE ENHANCED IONIZATION SPECTROSCOPY OF A JET COOLED, STATE SELECTED BEAM OF OH RADICALS

$^{a}$M. C. van Beek and J. J. ter Meulen, Chem. Phys. Lett. 337, 237 (2001). $^{b}$E. de Beer, M. P. Koopmans, C. A. de Lange, Y. Wang and W. A. Chupka, J. Chem. Phys. 94, 7634 (1991).Author Institution: Department of Chemistry, University of Pennsylvania; Department of Molecular and Laser Physics, University of NijmegenA (2 + 1) resonance enhanced multiphoton ionization (REMPI) technique has been used to characterize transitions of the OH radical from its ground $X^{2}\Pi$ state to the $D^{2}\Sigma^{-}$ and $3^{2}\Sigma^{-}$ Rydberg states. The OH radicals are produced by a $H_{2}O$ discharge in a pulsed free-jet $expansion.^{a}$ The supersonic expansion cools OH to its lowest rovibrational level and greatly simplifies the REMPI bands to three strong lines, $Q_{1}(1), R_{1}(1)$, and $S_{1}(1)$. Time of flight detection is gated on the $OH^{+}$ mass channel, however, interference from strong $H_{2}O$ transitions in this energy region can also appear. In order to further clarify these spectra, hexapole field focusing is implemented. The hexapole state selects OH molecules with the $|M_{J}| = 3/2$ component of the upper A-doublet level (f-symmetry) of the lowest rotational state of OH $X^{2}\Pi_{3/2} (v = 0, J = 3/2)$ and focuses these molecules to the point of laser interaction. This focusing results in a five to six fold enhancement of the $Q_{1}(1)$ and $S_{1}(1)$ lines that originate from the selected ground state level. These experimental conditions have allowed for the discovery of new, higher vibrational levels in each of the Rydberg states, specifically $D^{2}\Sigma^{-} (v = 3)$ and $3^{2}\Sigma^{-} (v = 1, 2)$. Spectroscopic constants characteristic of OH in these Rydberg states are determined based on the rotational band structure in the REMPI spectra. The constants will be compared with previous experimental work of lower vibrational $levels^{b}$ and theoretical predictions of transition probabilities

Predissociation of the A(2)Sigma(+) (v '=3) state of the OH radical

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Photodissociation of vibrationally excited OH/OD radicals

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Depression, anxiety, and quality of life as predictors of rehospitalization in patients with chronic heart failure

Abstract Background Chronic heart failure (CHF) is a severe condition, often co-occurring with depression and anxiety, that strongly affects the quality of life (QoL) in some patients. Conversely, depressive and anxiety symptoms are associated with a 2–3 fold increase in mortality risk and were shown to act independently of typical risk factors in CHF progression. The aim of this study was to examine the impact of depression, anxiety, and QoL on the occurrence of rehospitalization within one year after discharge in CHF patients. Methods 148 CHF patients were enrolled in a 10-center, prospective, observational study. All patients completed two questionnaires, the Hospital Anxiety and Depression Scale (HADS) and the Questionnaire Short Form Health Survey 36 (SF-36) at discharge timepoint. Results It was found that demographic and clinical characteristics are not associated with rehospitalization. Still, the levels of depression correlated with gender (p ≤ 0.027) and marital status (p ≤ 0.001), while the anxiety values ​​were dependent on the occurrence of chronic obstructive pulmonary disease (COPD). However, levels of depression (HADS-Depression) and anxiety (HADS-Anxiety) did not correlate with the risk of rehospitalization. Univariate logistic regression analysis results showed that rehospitalized patients had significantly lower levels of Bodily pain (BP, p = 0.014), Vitality (VT, p = 0.005), Social Functioning (SF, p = 0.007), and General Health (GH, p = 0.002). In the multivariate model, poor GH (OR 0.966, p = 0.005) remained a significant risk factor for rehospitalization, and poor General Health is singled out as the most reliable prognostic parameter for rehospitalization (AUC = 0.665, P = 0.002). Conclusion Taken together, our results suggest that QoL assessment complements clinical prognostic markers to identify CHF patients at high risk for adverse events. Clinical Trial Registration: The study is registered under http://clinicaltrials.gov (NCT01501981, first posted on 30/12/2011), sponsored by Charité – Universitätsmedizin Berlin

Control and imaging of O(1D2) precession

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