Multiphoton ionization of cesium atoms above and below the two-photon ionization threshold

Two- and three-photon ionization processes in cesium atoms using a single pulsed-dye laser and a cesium atomic beam have been investigated. Photoelectron angular distributions have been measured for two-photon resonant, three-photon ionization via the nd states (n = 12, 15, and 21), for two-photon nonresonant transitions over the photoelectron energy range from approx. 26 to 100 MeV, and for quasi-free-free transitions. 13 references, 6 figures

Infrared generation and wave-mixing studies in cesium

A Nd-YAG pumped dye laser and heat pipe has been used to investigate stimulated infrared production, wave mixing, and ionization in cesium vapor near the one-photon resonant 7P/sub 1/2,3/2/ fine structure states

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

Background: Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods: The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results: A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion: Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)

SPECTROSCOPY OF HELIUM HYDRIDE

Author Institution: Max-Planck-Institut f\""ur QuantenoptikDiscrete spectra of HeH were observed after neutralization of a fast $HeH^{+}$ ion beam. A careful determination of Doppler shifts and Doppler broadenings allowed to determine line positions and line broadenings with an accuracy of 0.1 {\AA}. Accurate molecular constants for the band near 8000 {\AA} were obtained for four isotopic mixtures and are compared with recent ab inition calculations. Isotope effects are discussed. The linewidth of the band near 8000 {\AA} shows that the $A^{2}\Sigma^{+}$ state of HeH predissociates with a lifetime of about 4 ps. The observed intensities of the lines can only be explained if an rotational excitation of $HeH^{+}$ of several thousand K is assumed. A first analysis of further bands of HeH in the visible region indicates, that the electronic structure of HeH is very similar to that of the Li atom

Multiphoton Ionization of Cesium Atoms Above and Below The Two-Photon Ionization Threshold

The experimental arrangement consisted of a Nd:YAG pumped pulsed dye laser which was focused and crossed at right angle with a cesium beam. Photoelectrons were energy-analyzed by a spherical sector energy analyzer and detected with a dual multichannel plate.</jats:p