The microbiological and sensory status of dual-purpose chickens (Lohmann Dual), male Lohmann Brown Plus chickens, and conventional laying hens slaughtered in a laying hen abattoir compared to conventional broilers slaughtered in a broiler abattoir

Alternatives to conventional chicken meat and egg production are increasingly under discussion, especially because of the common practice of killing male day-old chicks from laying lines which has been banned from the beginning of 2022 in Germany and is planned to be banned during 2022 in other countries. Production of dual-purpose chicken lines is one possible solution, as such lines combine moderate laying and growth performance. The microbiological status of products from such breeds must be comparable to existing products on the market for food safety purposes. Additionally, the production of such products will take longer because of the feeding regimes required, and again, comparability should be safeguarded for the best consumer protection. The dual-purpose chicken line, Lohmann Dual (males), was compared to males from the laying line Lohmann Brown Plus, conventional laying hens (all slaughtered and processed in the same conventional laying hen abattoir), and conventional broilers (slaughtered in a conventional broiler abattoir). Neck skin samples were taken before chilling at the end of each slaughter line to determine the microbial status of the carcasses. Additionally, fresh and cooked meat sensory analysis was performed on meat from broilers and male and female Lohmann Dual and Lohmann Brown Plus chickens (for three carcasses of each group) at the German Agricultural Society Test Center in Kassel. The focus was on the performance of male Lohmann Dual compared to the other lines. There was no difference in the Enterobacteriaceae count of the dual-purpose chicken line compared to conventional broilers, whereas laying hens had a significantly higher microbial load before chilling, as based on neck skin examinations (p<0.001). According to sensory test results, the meat from dual-purpose chickens was the best (as no defects were found) among the five chicken meat types examined. In conclusion, based on their microbial status and sensory analysis of fresh and cooked meat, Lohmann Dual males slaughtered in a laying hen abattoir can be considered as an alternative to conventionally kept broilers slaughtered in a broiler abattoir

Ion implantation of 226Ra for a primary 222Rn emanation standard

Laser resonance ionization at the RISIKO 30 kV mass separator has been used to produce isotopically and isobarically pure and well quantified 222Rn emanation standards. Based upon laser-spectroscopic preparation studies, ion implantation into aluminum and tungsten targets has been carried out, providing overall implantation efficiencies of 40% up to 60%. The absolute implanted activity of 226Ra was determined by the technique of defined solid-angle α-particle spectrometry, where excellent energy resolution was observed. The 222Rn emanation coefficient of the produced targets was studied using α-particle and γ-ray spectrometry, and yielded results between 0.23 and 0.34, with relative uncertainty on the order of 1%. No dependence exceeding a 1% change of the emanation on humidity could be identified in the range of 15 %rH to 75 %rH, whereas there were hints of a slight correlation between the emanation and temperature. Additionally, and as expected, the emanation coefficient was found to be dependent on the target material as well as the implanted dose. © 202

Termination of atrial flutter by directed transesophageal atrial pacing during transesophageal echocardiography: Terminierung von Vorhofflattern mit gerichteter transösophagealer Vorhofstimulation bei transösophagealer Echokardiographie

Introduction: The purpose of this study was to evaluate termination of atrial flutter (AFL) by directed rapid transesophageal atrial pacing (TAP) with and without simultaneous transesophageal echocardiography (TEE) performed using a novel TEE tube electrode. Materials and methods, and Results: A total of 16 AFL patients (age 63"12 years; 13 males) with mean AFL cycle length of 224"24 ms (ns12) and mean ventricular cycle length of 448"47 ms (ns12) were analyzed using either an esophageal TO electrode (ns10) or a novel TEE tube electrode consisting of a tube with four hemispherical electrodes that is pulled over the echo probe (ns6). AFL could be terminated by directed rapid TAP using an esophageal TO electrode, leading to induction of atrial fibrillation (AF) (ns6), induction of AF and spontaneous conversion to sinus rhythm (SR) (ns3), and with conversion to SR (ns1). AFL could also be terminated by directed rapid TAP using the TEE tube electrode, with induction of AF (ns3) or induction of AF and pontaneous conversion to SR (ns3). Conclusion: AFL can be terminated by directed rapid TAP with hemispherical electrodes with and without simultaneous TEE. TAP with the directed TEE tube electrode is a safe, simple, and useful method for terminating AFL

Tunable diamond raman lasers for resonance photo-ionization and ion beam production

Lasers with wide tunability and tailored linewidth are key assets for spectroscopy research and applications. We show that diamond, when configured as a Raman laser, provides agile access to a broad range of wavelengths while being capable of efficient and selective photo-excitation of atomic species and suitable spectroscopic applications thanks to its narrow linewidth. We demonstrate the use of a compact diamond Raman laser capable of efficient ion beam production by resonance ionization of Sm isotopes in a hot metal cavity. The ionization efficiency was compared with a conventional Ti:sapphire laser operating at the same wavelength. Our results show that the overall ion current produced by the diamond Raman laser was comparable -or even superior in some cases-to that of the commonly used Ti:sapphire lasers. This demonstrates the photo-ionization capability of Raman lasers in the Doppler broadening-dominated regime, even with the considerable differences in their spectral properties. In order to theoretically corroborate the obtained data and with an eye on studying the most convenient spectral properties for photo-ionization experiments, we propose a simple excitation model that analyzes and compares the spectral overlap of the Raman and Ti:Sapphire lasers with the Doppler-broadened atomic spectral line. We demonstrate that Raman lasers are a suitable source for resonance photo-ionization applications in this regime

In-source high-resolution spectroscopy of holmium radioisotopes - On-line tailored perpendicular laser interaction at ISOLDE's Laser Ion Source and Trap LIST

The combination of resonant laser ionization and electromagnetic mass separation has become an extremely powerful and versatile tool for the study of atomic and nuclear physics properties of exotic species over the last decades. It exploits step-wise resonant excitation and subsequent ionization by laser light precisely tuned to unique, fingerprint-like resonances in the electronic shell as a technique, which is both highly efficient and inherently element-selective. It is applied at the majority of large scale radioactive ion beam facilities world-wide, directly coupled to the production of radioactive species which are presented to laser ionization in a hot atomic vapor cavity. This ion source type is an excellent environment for direct laser spectroscopic investigations on the atomic structure. Fundamental ground state properties of the nucleus can be derived from minute effects arising from interactions with the electronic shell. Most commonly, such hyperfine structure investigations are prevented by the limited spectral resolution due to Doppler broadening in the hot atomic vapor. This thesis comprises the development, characterization and first-time application of a laser ion source specialized for high resolution laser spectroscopy. It is based on the Perpendicularly Illuminated Laser Ion Source and Trap (PI-LIST), which was recently developed in the LARISSA group, and uses a perpendicular geometry between incident laser light and the atomic beam effusing from a hot cavity to overcome Doppler limitations. As this previous setup relies on lateral laser in-coupling through windows at the source vacuum vessel, the upgrade presented here is tailored for installation at radioactive ion beam facilities such as CERN-ISOLDE, where access to the highly radioactive front end area is impossible. With this novel tool, high resolution hyperfine structure studies on long-lived, radioactive holmium isotopes were performed at the RISIKO mass separator at Mainz University. The extremely dense spectra arising from the coupling of both high nuclear spin and total angular momenta of the atomic states demanded high spectral resolution far beyond the capabilities of a standard hot cavity laser ion source. With outstanding experimental line widths as low as 100 MHz FWHM, the first-time extraction of nuclear structure parameters of $^{166m}$Ho was possible. Its nuclear spin was confirmed as $I$ = 7. Additionally, the results on the magnetic dipole moment, the spectroscopic quadrupole moment and the first determination of the change in mean square charge radii towards the neutron-rich side of the holmium isotopic chain resolve inconsistencies in literature data and confirm the pronounced prolate deformation in this mid-shell region of the nuclear chart. The PI-LIST with internal reflection proved to be completely competitive to the previous mode with external lateral laser incoupling in all operational parameters. On dedicated characterization experiments, ultimate line widths of as low as 60 MHz were achieved, and an overall efficiency of the setup of up to the 10$^{-4}$ regime was confirmed. The PI-LIST is thus proven to be ready for installation at on-line facilities

In-source high-resolution spectroscopy of holmium radioisotopes - On-line tailored perpendicular laser interaction at ISOLDE's Laser Ion Source and Trap LIST

The combination of resonant laser ionization and electromagnetic mass separation has become an extremely powerful and versatile tool for the study of atomic and nuclear physics properties of exotic species over the last decades. It exploits step-wise resonant excitation and subsequent ionization by laser light precisely tuned to unique, fingerprint-like resonances in the electronic shell as a technique, which is both highly efficient and inherently element-selective. It is applied at the majority of large scale radioactive ion beam facilities world-wide, directly coupled to the production of radioactive species which are presented to laser ionization in a hot atomic vapor cavity. This ion source type is an excellent environment for direct laser spectroscopic investigations on the atomic structure. Fundamental ground state properties of the nucleus can be derived from minute effects arising from interactions with the electronic shell. Most commonly, such hyperfine structure investigations are prevented by the limited spectral resolution due to Doppler broadening in the hot atomic vapor. This thesis comprises the development, characterization and first-time application of a laser ion source specialized for high resolution laser spectroscopy. It is based on the Perpendicularly Illuminated Laser Ion Source and Trap (PI-LIST), which was recently developed in the LARISSA group, and uses a perpendicular geometry between incident laser light and the atomic beam effusing from a hot cavity to overcome Doppler limitations. As this previous setup relies on lateral laser in-coupling through windows at the source vacuum vessel, the upgrade presented here is tailored for installation at radioactive ion beam facilities such as CERN-ISOLDE, where access to the highly radioactive front end area is impossible. With this novel tool, high resolution hyperfine structure studies on long-lived, radioactive holmium isotopes were performed at the RISIKO mass separator at Mainz University. The extremely dense spectra arising from the coupling of both high nuclear spin and total angular momenta of the atomic states demanded high spectral resolution far beyond the capabilities of a standard hot cavity laser ion source. With outstanding experimental line widths as low as 100 MHz FWHM, the first-time extraction of nuclear structure parameters of 166mHo was possible. Its nuclear spin was confirmed as I = 7. Additionally, the results on the magnetic dipole moment, the spectroscopic quadrupole moment and the first determination of the change in mean square charge radii towards the neutron-rich side of the holmium isotopic chain resolve inconsistencies in literature data and confirm the pronounced prolate deformation in this mid-shell region of the nuclear chart. The PI-LIST with internal reflection proved to be completely competitive to the previous mode with external lateral laser incoupling in all operational parameters. On dedicated characterization experiments, ultimate line widths of as low as 60 MHz were achieved, and an overall efficiency of the setup of up to the 10^(-4) regime was confirmed. The PI-LIST is thus proven to be ready for installation at on-line facilities.Die Kombination von resonanter Laserionisation mit elektromagnetischer Massenseparation hat sich über die letzten Jahrzehnte zu einem leistungsfähigen und vielseitigen Werkzeug zum Studium der Atom- und Kernphysik exotischer Spezies entwickelt. Die Methode nutzt schrittweise, resonante Anregung mit abschließender Ionisation durch präzise abgestimmte Laserstrahlung über die spezifischen optischen Übergänge der Atomhülle und stellt damit eine sowohl hocheffiziente als auch inhärent elementselektive Technik dar. Sie wird weltweit an Isotopenfabriken verschiedener Großforschungseinrichtungen eingesetzt, wo direkte Kopplung an die Erzeugung radioaktiver Spezies besteht, die als Atomdampf in einer heißen Kavität zur Ionisation zur Verfügung gestellt werden. Diese Geometrie ist gleichermaßen eine exzellente Umgebung für laserspektroskopische Untersuchungen der Atomstruktur. Fundamentale Grundzustandseigenschaften des Kerns können über ihre Wechselwirkung mit der Elektronenhülle abgeleitet werden. Gewöhnlich verhindert die durch die Dopplerverbreiterung in der heißen Kavität begrenzte spektrale Auflösung jedoch solche Untersuchungen. Die vorliegende Arbeit beinhaltet die Entwicklung, vollständige Charakterisierung sowie erstmalige Anwendung einer Laserionenquelle, die auf hochauflösende Laserspektroskopie spezialisiert ist. Sie basiert auf der ebenfalls in der LARISSA-Arbeitsgruppe entwickelten Perpendicular Illuminated Laser Ion Source and Trap (PI-LIST) und verwendet transversal zum aus der heißen Kavität austretenden Atomstrahl eingestrahltes Laserlicht, um die Doppler-Limitierung zu überwinden. Während dieser vormalige Aufbau auf seitlicher Lasereinkopplung durch Fenster an der Quellenvakuumkammer beruht, ist das hier vorgestellte Upgrade maßgeschneidert für eine Installation an Einrichtungen zur Erzeugung radioaktiver Ionenstrahlen, an denen Zugriff auf den hochradioaktiven Quellenbereich unmöglich ist. Mit diesem neuen Aufbau wurden hochauflösende Hyperfeinstrukturuntersuchungen an langlebigen radioaktiven Holmiumisotopen am RISIKO-Massenseparator der Universtität Mainz durchgeführt. Die extrem dichten Spektren, die in der Kopplung von sowohl hohem Kernspin als auch hohem Gesamtdrehimpuls der zugänglichen atomaren Zustände begründet sind, erfordern spektrale Auflösung weit jenseits der Doppler-verbreiteten Situation in einer Standardionenquelle mit heißer Kavität. Durch herausragende experimentelle Linienbreiten bis unterhalb von 100 MHz gelang die erstmalige Bestimmung von Kernstrukturparametern von 166mHo. Der Kernspin wurde mit $I$ = 7 bestätigt. Weiterhin lösen die Ergebnisse für das magnetische Dipolmoment, das spektroskopische Quadrupolmoment sowie die erstmalige Bestimmung der Änderung des mittleren quadratischen Ladungsradius auf der neutronenreichen Seite der Holmium-Isotopenkette Unstimmigkeiten in den verfügbaren Literaturdaten und bestätigen die stark prolate Kerndeformation in diesem Bereich der Nuklidkarte. Die PI-LIST mit interner Laserreflektion hat sich bezüglich aller operativer Parameter als vollständig ebenbürtig zu dem vormals verwendeten Modus mit externer seitlicher Lasereinstrahlung gezeigt. In dedizierten Experimenten wurden spektrale Linienbreiten von bis zu 60 MHz erreicht, und eine Gesamteffizienz des Aufbaus bis in den Bereich von 10^(-4) wurde bestätigt. Damit steht die PI-LIST einer Installation an on-line-Einrichtungen zur Verfügung. Die Arbeit wird abgerundet durch eine Zusammenstellung verschiedener weiterer Entwicklungen im Bereich der Ionenquellen mit heißer Kavität. Dabei stehen die Optimierung von Effizienz sowie die Ionenstrahlreinheit im Vordergrund

Electrode Model and Simulation of His- Bundle Pacing for Cardiac Resynchronization Therapy

A disturbed synchronization of the ventricular contraction can cause a highly developed systolic heart failure in affected patients with reduction of the left ventricular ejection fraction, which can often be explained by a diseased left bundle branch block (LBBB). If medication remains unresponsive, the concerned patients will be treated with a cardiac resynchronization therapy (CRT) system. The aim of this study was to integrate His-bundle pacing into the Offenburg heart rhythm model in order to visualize the electrical pacing field generated by His-Bundle-Pacing. Modelling and electrical field simulation activities were performed with the software CST (Computer Simulation Technology) from Dessault Systèms. CRT with biventricular pacing is to be achieved by an apical right ventricular electrode and an additional left ventricular electrode, which is floated into the coronary vein sinus. The non-responder rate of the CRT therapy is about one third of the CRT patients. His- Bundle-Pacing represents a physiological alternative to conventional cardiac pacing and cardiac resynchronization. An electrode implanted in the His-bundle emits a stronger electrical pacing field than the electrical pacing field of conventional cardiac pacemakers. The pacing of the Hisbundle was performed by the Medtronic Select Secure 3830 electrode with pacing voltage amplitudes of 3 V, 2 V and 1,5 V in combination with a pacing pulse duration of 1 ms. Compared to conventional pacemaker pacing, His-bundle pacing is capable of bridging LBBB conduction disorders in the left ventricle. The His-bundle pacing electrical field is able to spread via the physiological pathway in the right and left ventricles for CRT with a narrow QRS-complex in the surface ECG