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Nature / Physical science 590(7846), 401 - 404 (2021). doi:10.1038/s41586-021-03276-x, Coherent control of quantum dynamics is key to a multitude of fundamental studies and applications. In the visible or longer-wavelength domains, near-resonant light fields have become the primary tool with which to control electron dynamics. Recently, coherent control in the extreme-ultraviolet range was demonstrated, with a few-attosecond temporal resolution of the phase control. At hard-X-ray energies (above 5–10 kiloelectronvolts), Mössbauer nuclei feature narrow nuclear resonances due to their recoilless absorption and emission of light, and spectroscopy of these resonances is widely used to study the magnetic, structural and dynamical properties of matter. It has been shown that the power and scope of Mössbauer spectroscopy can be greatly improved using various control techniques. However, coherent control of atomic nuclei using suitably shaped near-resonant X-ray fields remains an open challenge. Here we demonstrate such control, and use the tunable phase between two X-ray pulses to switch the nuclear exciton dynamics between coherent enhanced excitation and coherent enhanced emission. We present a method of shaping single pulses delivered by state-of-the-art X-ray facilities into tunable double pulses, and demonstrate a temporal stability of the phase control on the few-zeptosecond timescale. Our results unlock coherent optical control for nuclei, and pave the way for nuclear Ramsey spectroscopy and spin-echo-like techniques, which should not only advance nuclear quantum optics, but also help to realize X-ray clocks and frequency standards. In the long term, we envision time-resolved studies of nuclear out-of-equilibrium dynamics, which is a long-standing challenge in Mössbauer science., Published by Macmillan28177, London

We develop two ab initio quantum approaches to thin-film x-ray cavity quantum electrodynamics with spectrally narrow x-ray resonances, such as those provided by M\"ossbauer nuclei. The first method is based on a few-mode description of the cavity, and promotes and extends existing phenomenological few-mode models to an ab initio theory. The second approach uses analytically-known Green's functions to model the system. The two approaches not only enable one to ab initio derive the effective few-level scheme representing the cavity and the nuclei in the low-excitation regime, but also provide a direct avenue for studies at higher excitation, involving non-linear or quantum phenomena. The ab initio character of our approaches further enables direct optimizations of the cavity structure and thus of the photonic environment of the nuclei, to tailor the effective quantum optical level scheme towards particular applications. To illustrate the power of the ab initio approaches, we extend the established quantum optical modeling to resonant cavity layers of arbitrary thickness, which is essential to achieve quantitative agreement for cavities used in recent experiments. Further, we consider multi-layer cavities featuring electromagnetically induced transparency, derive their quantum optical few-level systems ab initio, and identify the origin of discrepancies in the modeling found previously using phenomenological approaches as arising from cavity field gradients across the resonant layers., Comment: 41 pages, 20 figures, added clarifications and minor corrections

Physical review letters 123(15), 153902 (2019). doi:10.1103/PhysRevLett.123.153902, We introduce an analytical phase-reconstruction principle that retrieves atomic scale motion via timedomaininterferometry. The approach is based on a resonant interaction with high-frequency light and doesnot require temporal resolution on the time scale of the resonance period. It is thus applicable to hard x raysand γ rays for measurements of extremely small spatial displacements or relative-frequency changes. Here,it is applied to retrieve the temporal phase of a 14.4 keVemission line of an 57Fe sample, which correspondsto a spatial translation of this sample. The small wavelength of this transition (λ ¼ 0.86 Å) allows fordetermining the motion of the emitter on sub-Ångström length and nanosecond timescales., Published by APS, College Park, Md.

Science 357(6349), 375 - 378(2017). doi:10.1126/science.aan3512, Spectroscopy of nuclear resonances offers a wide range of applications due to the remarkable energy resolution afforded by their narrow linewidths. However, progress toward higher resolution is inhibited at modern x-ray sources because they deliver only a tiny fraction of the photons on resonance, with the remainder contributing to an off-resonant background. We devised an experimental setup that uses the fast mechanical motion of a resonant target to manipulate the spectrum of a given x-ray pulse and to redistribute off-resonant spectral intensity onto the resonance. As a consequence, the resonant pulse brilliance is increased while the off-resonant background is reduced. Because our method is compatible with existing and upcoming pulsed x-ray sources, we anticipate that this approach will find applications that require ultranarrow x-ray resonances., Published by AAAS, Washington, DC [u.a.]

There is a need for cheap and efficacious wound dressings in developing countries. Banana leaves have been described as an excellent, inexpensive, easily available dressing material in tropical countries. As a natural product, banana leaves are heavily contaminated with various pathogens that must be removed before they can be used as wound dressings, but effective sterilization methods that do not affect the beneficial wound-dressing properties of banana leaves have not been described.To study different sterilization methods and determine which can be used on banana leaves without affecting their beneficial wound-dressing properties.We first compared the use of different decontamination techniques to reduce the natural microflora of the leaves and then tested the wound-dressing properties of the leaves in a mouse model of skin transplantation and in postsurgical patients in Uganda, Africa.Steam sterilization proved to be the optimal sterilization technique. Banana leaves displayed wound-dressing properties that equaled those of petroleum jelly gauze dressings and were tested successfully in a clinical setting in postsurgical patients in Uganda, Africa.We found banana leaves to be an excellent alternative wound dressing, combining the desirable properties of modern wound-dressing material with low cost.

Zusammenfassung Es wird ein kurzer Uberblick uber die Entstehung der Krankenhaushygiene in Europa und ihre weitere Entwicklung Deutschland gegeben. Von besonderer Bedeutung sind dabei, nach der Entdeckung und Einfuhrung der Antibiotika, die Anwendung des Qualitatsmanagements und die Platzierung der Krankenhaushygiene im System einer evidenzbasierten Medizin. Schlieslich stellt die Zunahme von multiresistenten Erregern eine alarmierende Entwicklung dar, die durch die Krankenhaushygiene alleine zwar nicht zu beherrschen, in ihren Auswirkungen aber zu beschranken ist.

Die Spektroskopie schmaler Resonanzen ist ein Schlusselbaustein vieler moderner Anwendungen. Pulse moderner Rontgenlichtquellen sind jedoch spektral viel breiter als die zu untersuchenden Resonanzen, so dass nur ein kleiner Teil des Lichts wechselwirkt und zum Signal beitragt. Kurzlich ist es unserem Team gelungen, solche Pulse so zu manipulieren, dass zuvor ungenutzte Photonen in Resonanz geschoben werden. Die „gescharften“ Rontgenpulse eroffnen eine Vielzahl von Anwendungen.

The following on new requirements of endoscopy contains commentaries on the risk of infection in endoscopy, the need to eliminate contamination, and the use of a disposable system in transnasal endoscopy.

Zusammenfassung Ziel Das Ziel dieser Untersuchungen war herauszufinden, ob eine Kontamination des Fusbodens in einem OP mit Schichtluftungssystem zu einer Kontamination des OP-Gebiets fuhrt. Hintergrund Schichtuftungssysteme fuhren die Luft bodennah dem Raum zu und sie steigt an Warmequellen (z.B. Gerate, Personen) auf. Dabei konnten potentiell Verunreinigungen vom Fusboden in das OP-Gebiet getragen werden. Methoden Es wurde verschiedene Methoden (u.a. aktive Luftkeimsammlung, Sedimentationsplatten, Starkenachweis) angewendet. Ergebnis Mit keiner der angewandten Methoden konnte die Kontamination des Fusbodens auf den OP-Tisch wiedergefunden werden. Schlussfolgerung Die Versuche legen die Schlussfolgerung nahe, dass die Kontamination des Fusbodens im OP – wenn uberhaupt – eine untergeordnete Rolle fur die Kontamination des Operationsgebietes spielt.

Summary Background: Accurate pre-operative or intra-operative labeling of the skin is often necessary to mark exactly the surgical excision lines. Pre-operative “unsterile” permanent skin labeling systems are needed for example for vein and sentinel lymph node surgery; here the dyes must resist two surgical skin disinfection procedures. In contrast, excision borders are labeled during surgery using a “sterile” skin marking system. Methods: Many commercial and non-commercial pre- and intra-operative skin-labeling systems are available, such as autologous patient blood, fluorescence triphenylmethane dyes and commercial skin markers. The available skin marking systems have specific advantages and disadvantages. We review the different labeling systems, offering guidelines to help choose a cost-effective system appropriate for a given surgical procedure. Results: The Edding® permanent markers 400 und 3000 are well suited for preoperative skin labeling and less expensive than commercial skin labeling systems. Autologous patient blood and eosin are well suited for intra-operative labeling and are most cost effective. Eosin Y is widely used and well suited for labeling of dark skin, bone, cartilage, and muscle tissue and spares the expense of expensive commercial skin markers. Conclusion: Knowledge of the many commercial and non-commercial pre- and intra-operative skin labeling systems and their advantages and disadvantages helps to reduce the use of relatively expensive commercial skin markers.

Zusammenfassung Trotz der markanten Veranderungen der infektionsepidemiologischen Situation ebenso wie der Gesetzeslage in den letzten Jahrzehnten in Deutschland bieten die Desinfektionsmittel-Listen des Verbundes fur Angewandte Hygiene (VAH) und des Robert Koch-Instituts (RKI) eine zuverlassige Orientierungshilfe bei der Auswahl geeigneter Desinfektionsmittel und -verfahren. Unter dem Einfluss der europaischen Normung haben sich die Prufmethoden fur chemische Desinfektionsverfahren geandert und sind im Hiblick auf die praktische Anwendung differenzierter geworden. Bedarf besteht allerdings noch fur Prufverfahren zur Viruzidie und zur Sporizidie sowie fur die chemisch-thermische Desinfektion, sodass die Anwender hier auf zusatzliche Informationsquellen zuruckgreifen mussen. Hinweise auf eine Desinfektionsmittel-Resistenz liegen in der Litaratur vor. Hier sind weitere Arbeiten notwendig, Konsequenzen fur die Desinfektionspraxis ergeben sich derzeit (noch) nicht.

The increasing number of complicated soft-tissue or invasive infections caused by methicillin-resistant Staphylococcus aureus (MRSA) is a frequent reason for elaborate treatment regimens. Unidentified MRSA carriers may be the origin of endemic spread to other patients and medical staff. Recently, community-associated cMRSA with particular virulence factors were isolated from persons without the typical history of hospital contacts. Molecular tools for the timely detection of the mecA resistance gene for the identification of MRSA in medical test specimens have become a standard approach in MRSA-related diagnostic procedures. The actual therapy of MRSA infections requires consideration of both the appropriate spectrum of activity and the adequate pharmacological properties of a chosen antimicrobial. Preventive strategies rely on the consistent application of standard hygiene precautions, which have to be supplemented with increased barriers for the isolation of identified MRSA patients.

Modern x-ray light sources promise access to structure and dynamics of matter in largely unexplored spectral regions. However, the desired information is encoded in the light intensity and phase, whereas detectors register only the intensity. This phase problem is ubiquitous in crystallography and imaging, and impedes the exploration of quantum effects at x-ray energies. Here, we demonstrate phase-sensitive measurements characterizing the quantum state of a nuclear two-level system at hard x-ray energies. The nuclei are initially prepared in a superposition state. Subsequently, the relative phase of this superposition is interferometrically reconstructed from the emitted x-rays. Our results form a first step towards x-ray quantum state tomography, and provide new avenues for structure determination and precision metrology via x-ray Fano interference., 5 pages, 3 figures, plus supplementary information

The setting of Moessbauer nuclei embedded in thin-film cavities has facilitated an aspiring platform for x-ray quantum optics as shown in several recent experiments. Here, we generalize the theoretical model of this platform that we developed earlier [Phys. Rev. A 88, 043828 (2013)]. The theory description is extended to cover multiple nuclear ensembles and multiple modes in the cavity. While the extensions separately do not lead to qualitatively new features, their combination gives rise to cooperative effects between the different nuclear ensembles and distinct spectral signatures in the observables. A related experiment by Roehlsberger et al. [Nature 482, 199 (2012)] is successfully modeled, the scalings derived with semiclassical methods are reproduced, and a microscopic understanding of the setting is obtained with our quantum mechanical description., 18 pages, 6 figures

This report describes the isolation of a linezolid-resistant Enterococcus faecium and a carbapenem-resistant Acinetobacter baumannii from an infected open patella fracture after a car accident in southern Italy.

Objectives:To establish an animal model to study transmissible spongiform encephalopathy using hamsters and steel wires contaminated with infectious brain materials as transfer vehicles, and, based on this model, to test decontamination procedures against the infectious prion proteins on the steel wires as a near real situation bioassay.Design:Infectious brain materials were given to healthy hamsters intracerebrally either as a suspension or as dried materials on the surface of steel wires. The animals were observed for 18 months. During this period, animals showing definitive clinical signs were euthanized. Decontamination studies were performed by reprocessing contaminated steel wires with different disinfection agents and procedures before implantation.Results:Pathological prion proteins were able to bind to the steel wires and caused disease after the contaminated wires were implanted in the brains of hamsters. When the contaminated wires were treated with different reprocessing procedures before implantation, infectivity was reduced, which was manifested directly by prolonged survival time of the test animals. These results show that this model can be used as a bioassay to validate reprocessing procedures for surgical instruments.Conclusions:At the time of submission of this article, only the group of hamsters incubated with wires reprocessed with an alkaline detergent, followed by sterilization with a modified cycle in a hydrogen peroxide gas plasma sterilizer (4 injections), showed no clinical signs of disease and remained alive. Two animals from the group receiving sodium hydroxide followed by autoclaving (at 134° C for 18 minutes) died. Furthermore, the tested enzymatic cleaning agent seemed to have no positive effect.

Summary In 2001 two outbreak episodes (January – March and June – July) caused by vancomycin-resistant E. faecium (VRE) of the VanA-type were observed at a neonatal intensive care unit (NICU) of a university hospital in south-west Germany. To identify the initial source and the route of transmission environmental samples were examined as well as stool samples from patients and the staff. VRE was not found in environmental samples. However, stool samples from 24 hospitalised children tested positive and bacterial clonality was assessed by Smal-based macro restriction analysis. Furthermore, esp gene and vancomycin resistance gene carriage were examined as well as bacteriocin production. PCR analysis showed that all 24 isolates carried vanA gene cluster, encoding resistance to vancomycin and teicoplanin. However, five of the vanA-positive isolates were resistant to vancomycin but not to teicoplanin. Only these five isolates produced bacteriocin, but in none of the isolates esp gene was detected. PFGE revealed that both outbreaks were caused by two different clones. The patient initiating the first episode, was identified whereas the origin of the second episode remained unknown. From one of the 40 staff stool samples VRE was isolated. This strain was related to the clone of the summer outbreak. In conclusion there were two independent episodes of self limiting VRE outbreaks and transmission on the ward is highly probable.

The ion beam therapy facility HICAT presently under construction at the Heidelberg University Clinic will be the first clinical irradiation facility for heavy ions in Europe. Its capacity should enable the treatment of 1000 patients per year. The use of different ion species ranging from protons to oxygen under identical conditions should clarify the question of which particle species is best suited in terms of indication. A synchrotron will accelerate the particles to energies corresponding to water-equivalent ranges from 2 cm to 30 cm. An intensity-controlled raster scanning technique will be used to optimize the use of the favorable depth dose distribution of ions. The planned heavy-ion gantry will be the first world-wide. The facility should be complete in 2006.

Outbreaks of gram-negative bacteria such as Pseudomonas aeruginosa in neonatal intensive care units (NICU) can be life-threatening to pre-term infants, which are highly susceptible to serious infections with bacteria. Forty-two ventilated neonates in the NICU of the University Children's Hospital of Tuebingen were found to be colonized (n = 40) or infected (n = 2) with P. aeruginosa within a sampling period of one year. To investigate the colonization patterns and identify potential outbreak sources, epidemiological investigations, environmental surveillance and typing by serotyping and pulsed-field gel electrophoresis of the recovered isolates were performed. The investigation demonstrated a genetically related cluster of P. aeruginosa isolates during the surveillance period in 39 neonates and a second cluster at the end of the period in two neonates. A third strain representing a genetically distinct group was found in only one patient. Environmental investigations demonstrated the presence of P. aeruginosa in the ventilation equipment of 22 patients: binasal prongs (n = 22), water reservoir (n = 9), and heater (n = 1). In one case, P. aeruginosa was found in breast milk. Other environmental investigations revealed no P. aeruginosa. Although no evidence for a unique source was found, a series of intervention steps were initiated by the NICU personnel, medical microbiologists and infection control experts. The intervention steps included reinforced training of health care staff and a change from chemical to thermal disinfection of binasal prongs. Implementation of these measurements successfully stopped the recurrent occurrence of P. aeruginosa colonization.

Die Erfassung und Bewertung (Surveillance) von Wundinfektionen bildet die Basis fur hygienische Interventionen zur Reduktion der postoperativen Infektionshaufigkeit. Empfohlen wird eine prospektive Erfassung durch qualifiziertes Personal auf der Grundlage allgemein anerkannter Fallkriterien. Die Berechnung der Infektionsrate muss nach den unterschiedlichen Risiken der Patienten stratifiziert werden. Angaben aus Referenzdatenbanken erlauben die Berechnung standardisierter Wundinfektionsraten, die schlieslich zur Bewertung der eigenen Daten im Sinne eines Qualitatsmanagementsystems herangezogen werden konnen. Besonders schwierig gestaltet sich die nachstationare Erfassung, mit deren Hilfe jedoch ein erheblicher Teil der Wundinfektionen identifiziert werden kann.

Objective: To determine whether reprocessed single-use devices (SUD) would (1) meet regulatory standards for sterility, and (2) meet the same material standards as new devices or if they pose an infection risk to other patients. Design: The study included in the first stage single-use laparoscopic dissection devices and in the second stage a variety of clinically used and reprocessed SUDs. The suitability of these devices for cleaning, disinfection, and sterilization was examined.Methods: Testing of cleanability was conducted on devices contaminated with radioactively labeled blood. Instruments were cleaned using hospital recommended practices. Gamma counts/second were determined before and after cleaning to localize contaminants, which were additionally visualized using light and scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) was used to quantify contamination elements on the materials tested. Residual bioburden testing on instruments contaminated with microorganisms suspended in blood prior to reprocessing was carried out to establish the efficacy of disinfection and sterilization.Results: During the first stage of the study all devices remained contaminated after cleaning, but were effectively disinfected. Sterilization could not eliminate the challenge microorganisms completely. The findings during the second stage — examination of clinically used devices — were as follows: 11% of the sterile packages were damaged; 33% of the devices were incomplete and parts were missing; 54% did not meet the criteria for functionality; light microscopy, SEM, and XPS showed contamination on the outside and inside of all devices. Of the tested SUDs, 40% remained unsterile following resterilization.Conclusions: None of the reprocessed SUDs were effectively cleaned or sterilized. This may provide an opportunity for survival and growth of non-resistant or nosocomial organisms and viruses. The use of such inadequately reprocessed SUDs increases the risk for the patient, and can lead to nosocomial infection and to legal consequences for the health care facility.

Since December 1997, patients are treated with carbon ions at GSI (Gesellschaft fur Schwerionenforschung). Dose delivery is performed with the intensity-controlled raster-scanning technique, which allows a highly conformal treatment of the tumor. To meet the special requirements of dosimetry with heavy ion beams, new dosimetric measurement techniques were developed and introduced into clinical application by the DKFZ (Deutsches Krebsforschungszentrum). The techniques comprise calibration of the irradiation monitor, checks of lateral and depth dose profiles, as well as verification of the beam delivery for complex three-dimensional dose distributions. The developed dosimetric methods are now integral part of clinical application and enable safe treatment with carbon ion therapy.

Group velocity control is demonstrated for x-ray photons of 14.4 keV energy via a direct measurement of the temporal delay imposed on spectrally narrow x-ray pulses. Sub-luminal light propagation is achieved by inducing a steep positive linear dispersion in the optical response of ${}^{57}$Fe M\"ossbauer nuclei embedded in a thin film planar x-ray cavity. The direct detection of the temporal pulse delay is enabled by generating frequency-tunable spectrally narrow x-ray pulses from broadband pulsed synchrotron radiation. Our theoretical model is in good agreement with the experimental data., Comment: 8 pages, 4 figures

Objective:To determine whether reprocessed single-use devices would meet regulatory standards for sterility and meet the same materials standards as a new device.Design:The study included single-use and reusable biopsy forceps and papillotomes and a reusable stone retrieval basket. The suitability of these devices for cleaning and disinfection or sterilization was examined.Methods:Testing of cleanability was conducted on devices contaminated with technetium 99-radiolabeled human blood. Instruments were cleaned using hospital recommended practices for manual cleaning. Gamma counts per second were determined before and after cleaning to localize contaminants, which were additionally visualized using light and scanning electron microscopy. X-ray phc-toelectron spectroscopy was used to quantify contamination elements on the materials tested. Residual bioburden testing on instruments contaminated with microorganisms suspended in coagulable sheep blood was carried out to establish the efficacy of disinfection and sterilization.Results:All devices remained contaminated after cleaning, but single-use devices and the stone basket tended to be more heavily contaminated than reusable forceps and papillotomes. Cleaning procedures facilitated distribution of contaminants further into the lumens of the disposable forceps. Decreased concentrations of silicon and increased concentrations of carbon and nitrogen suggested that layers of silicon lubricant had been removed and contaminants were organic material. Reusable devices were effectively disinfected, but single-use devices were not Sterilization could not eliminate the challenge microorganisms completely.Conclusions:None of the reprocessed single-use instruments were effectively cleaned, disinfected, or sterilized. This condition may provide an opportunity for the viability of non-resistant or nosocomial organisms and viruses. Additionally, reprocessing procedures may result in material destruction of fragile devices. Cost-saving initiatives that have inspired reprocessing of single-use devices, despite the absence of data establishing the efficacy of decontamination and the durability of materials throughout reprocessing, should be pushed into the background.

Die Retransfusion postoperativ gesammelten Drainageblutes ist eine bei orthopadischen Eingriffen weit verbreitete Methode zur Einsparung von Fremdblutkonserven. Vorteile gegenuber der Verwendung homogener Blutkonserven bestehen darin, dass immunologische Reaktionen auf Fremdblut unterbleiben und Infektionskrankheiten nicht ubertragen werden konnen. Nachteilig ist die Gefahr der Sekundarverkeimung und der hamatogenen Streuung von Infektionen. Zur Verringerung dieser Risiken werden folgende Masnahmen empfohlen: Die Kontraindikationen Infektionen, maligne Erkrankungen und Gerinnungsstorungen sind vor dem Einsatz zu beachten. Eine perioperative Antibiotikaprophylaxe ist empfehlenswert. Das System muss steril angeschlossen werden. Antikoagulanzien und Stabilisatoren sollten nicht nachgespritzt werden. Ein Offnen von Leitungen ist zu vermeiden. Bei Auftreten febriler Reaktionen sollte die Retransfusion abgebrochen werden. Die Methode sollte nur wahrend der ersten sechs postoperativen Stunden angewendet werden.

At an isocentric irradiation facility, the rotation axis of the treatment table has to be accurately aligned in vertical orientation to the isocentre, which is usually marked by three perpendicular laser planes. In particular, high precision radiotherapy techniques, such as radiosurgery or intensity modulated radiotherapy, require a higher alignment accuracy of the table axis than routinely specified by the manufacturers. A simple and efficient method is presented to measure the direction and the size of the displacement of the table axis from the isocentre as marked by the lasers. In addition, the inclination of the table axis against the vertical direction can be determined. The measured displacement and inclination provide the required data to correct for possible misalignments of the treatment table axis and to maintain its alignment. Measurements were performed over a period of two years for a treatment table located at the German heavy ion therapy facility. The mean radial distance between the table axis and the isocentre was found to be 0.25 +/- 0.25 mm. The mean inclination of the table axis in the XZ- and YZ-planes was measured to be -0.03 +/- 0.02 degrees and -0.04 +/- 0.01 degrees, respectively. The measurements demonstrate the good alignment of the treatment table over the analysed time period. The described method can be applied to any isocentric irradiation facility, especially including isocentric linear accelerators used for radiosurgery or other high precision irradiation techniques.

UNLABELLED Reprocessing (repeated cleaning, disinfection, and sterilization) and reuse of single-use medical devices has been performed safely with some devices. The aim of our study was to analyze whether reprocessing of the Combitubes (Kendall-Sheridan, Argyll, NY) airway device, used for emergency endotracheal intubation and difficult airway management, is possible and can be performed appropriately and safely. Microbiological, microstructure, and material science examinations were performed with unused, as well as multiple reused and reprocessed Combitubes. The reprocessing procedure consisted of a cleaning, a disinfection, a final inspection, and a sterilization. Microbiological examinations of multiple reused and reprocessed Combitubes found no test organisms in quantitative cultures. A microbial reduction between four and five log levels compared with nonreprocessed tubes was found. Microstructure analysis for the examination of topographical alterations and changes in the chemical composition of the surface demonstrated nonsignificant alterations between new and reprocessed medical devices. In material science examinations, cuff burst pressures were not different between unused and multiple reprocessed Combitubes. The results of all examinations proved that the decontamination process is adequately effective, and that no significant superficial alterations are generated by the multiple reuse and reprocessing of the Combitubes. To assure uniformly good results, a quality management system must be established and only validated methods should be used. IMPLICATIONS Reprocessing of single-use medical devices offers the opportunity of significant savings and is already performed with some devices. Microbiological, microstructure, and material science examinations proved that reprocessing of multiple reused Combitubes (Kendall-Sheridan, Argyll, NY), mainly used for emergency airway management, is possible and safe.

A new class of 4-deoxy-4-([4-substituted-1-piperazinyl], [4-morpholinyl] and [4-(perhydrol, 4-thiazin-4-yl)])-2,3-anhydrolyxopyranosides (3a-g and 6a-g) were synthesized from epoxy triflate moities 2 and 5 and 4-substituted piperazines, morpholines and perhydro-1,4- thiazines, respectively, to test their antibacterial activity. The characterized series of new compounds was tested in vitro against E. coli ATCC11229, S. aureus ATCC6538 and C. albicans SATCC10231.

Cylindrical ionization chambers are used for the determination of absorbed dose in beams of heavy charged particles, where the effective point of measurement, P eff (the point in depth to which the measured dose refers), is a priori not known. A measurement of P eff for a Farmer-type chamber in a carbon ion beam is presented. It is based on a comparison of relative depth dose curves measured with a cylindrical chamber and a plane-parallel Markus chamber. Both measurements were compared against another high-precision relative depth dose measurement using large-area plane-parallel chambers. For P eff , a value of 72±7% of the inner radius of the chamber is obtained. The relative depth dose curve for the cylindrical chamber is calculated using an averaging of the depth dose values over the curved inner surface of the active volume while taking account of the different depths of points on the inner surface. Within the measurement uncertainty of 0.2 mm the measurements agree well with the calculated Bragg curve for the Farmer chamber. The result for P eff is in correspondence with the value suggested in a new code of practice by the IAEA for protons and ions, and somewhat less than that suggested by Palmans for protons. The measurements show that cylindrical chambers are in general well suited for depth dose measurements in fields of heavy charged particles if the correct P eff is used.

The benefit of using retrieval systems in minimally-invasive surgery is to facilitate the removal of operative specimen, while minimising the contamination of the peritoneum and port-sites in the abdominal wall. We have developed an innovative retrieval system with a mechanism of action and design that differs widely from other devices. Its increased functionality is achieved by combining it with a laparoscopic instrument: the resected tissue is wrapped in plastic foil, rather than being entrapped in a bag. During delivery through the abdominal wall, permanent traction is exerted on the specimen and thus obstruction in the port-site is avoided. The retrieval system has been tested for impermeability and proven to be safe and able to avoid spillage of cells.

The introduction of dynamic intensity modulation into radiotherapy using conventional photon beams or scanning particle beams requires additional and efficient methods of dose verification. Dose measurements in dynamically generated dose distributions with a single ionization chamber require a complete application of the treatment field for each single measurement. Therefore measurements are performed by simultaneous use of multiple ionization chambers. The measurement is performed by a computer controlled system and is comprised of the following steps: (a) automated positioning of the ionization chambers, (b) measurement at these points, (c) a comparison with the calculated dose from the treatment planning system, and (d) documentation of the measurement. The ionization chambers are read out by a multichannel electrometer and are densely packed into a mounting of polymethylmetacrylate, which is attached to the arm of a three-dimensional motor-driven water phantom. The measured and planned dose values are displayed numerically as well as graphically. The mean deviation between measured and planned doses as well as their standard deviation are calculated and displayed. Through printouts complete documentation of the measurement is obtained and a quick decision can be made whether the dose distribution is acceptable for the patient. The system is now routinely used for dose verification at the heavy ion therapy project at the Gesellschaft für Schwerionenforschung in Darmstadt. Up to now 242 measurements have been performed for heavy ion treatment of 30 patients. The system allows efficient verification and documentation of carbon ion fields and is in principle also applicable to intensity-modulated photon beams.

The method to measure absorbed dose to water in a field of carbon ions as applied for the heavy ion therapy project at the Heavy Ion Research Laboratory in Darmstadt (GSI), Germany, is described in detail. Thimble ionization chambers with a water absorbed calibration factor are applied. The dose obtained with this method was compared with that obtained at the heavy ion therapy facility HIMAC at the National Institute of Radiological Sciences in Chiba, Japan, using the Japanese code of practice. The agreement found was better than 1%. The combined uncertainty of the determination of absorbed dose to water was estimated to amount to 5%.

Zusammenfassung An der Strahlentherapieanlage der Gesellschaft fur Schwerionenforschung in Darmstadt wurde im Dezember 1997 an zwei Patienten erstmals eine strahlentherapeutische Behandlung mit Kohlenstoffionen mit Hilfe eines tumorkonformen Rasterbestrahlungsverfahrens durchgefuhrt. Fur die Dosimetrie wurden ein Protokoll zur Bestimmung der Wasserenergiedosis sowie Techniken zur Messung von Dosisverteilungen entwickelt. Aufbauend auf dem Prinzip der stereotaktischen Patientenpositionierung wurde eine zusatzliche Positionskontrolle mittels Rontgenrohren installiert. Die Bestrahlungsplanung basiert auf einem speziellen Algorithmus zur inversen Bestrahlungsplanung, der in das am Deutschen Krebsforschungszentrum (DKFZ) entwickelte VOXELPLANSystem integriert wurde. Fur die Abnahme- und Konstanzprufungen wurde ein Qualitatssicherungsprogramm entworfen, das erfolgreich durchgefuhrt wurde.

On the basis of a large outbreak of vancomycin-resistant Enterococcus faecium in a German university hospital, we estimated costs ( approximately 1 million Euros) that could have been avoided by early detection of the imminent outbreak. For this purpose, we demonstrate an easy-to-use statistical method.

Epidemiologie Die Haufigkeit von Infektionen im Krankenhaus durch Methicillin-(Oxacillin-)resistente Staphylococcus aureus (MRSA/ORSA) liegt in Europa zwischen 30% (Spanien, Italien, Frankreich), in Deutschland bei 8,7%. Diese Angaben in der Literatur erfassen den gegenwartigen Stand jedoch nicht zuverlassig.

In general, the desinfection of surfaces is done through scrubbing and wiping using substances on the basis of aldehydes, oxidants and tensides. We propose a 4-stage procedure (see Table 1). The concentration of the agent and the duration of application depend on the circumstances, whether one is dealing with a prophylactic measure, a nosocomial infection or an infection which has to be reported. The epidemiologic relevance dictates the extent of desinfection.

A promising platform for the emerging field of x-ray quantum optics are M\"ossbauer nuclei embedded in thin film cavities probed by near-resonant x-ray light, as used in a number of recent experiments. Here, we develop a quantum optical framework for the description of experimentally relevant settings involving nuclei embedded in x-ray waveguides. We apply our formalism to two settings of current experimental interest based on the archetype M\"ossbauer isotope 57Fe. For present experimental conditions, we derive compact analytical expressions and show that the alignment of medium magnetization as well as incident and detection polarization enable the engineering advanced quantum optical level schemes. The model encompasses non-linear and quantum effects which could become accessible in future experiments., Comment: 13 pages, 6 figures

Background In this study we investigate the accuracy of industrial six axes robots employed for patient positioning at the Heidelberg Ion Beam Therapy Center. Methods In total 1018 patient setups were monitored with a laser tracker and subsequently analyzed. The measurements were performed in the two rooms with a fixed horizontal beam line. Both, the 3d translational errors and the rotational errors around the three table axes were determined. Results For the first room the 3d error was smaller than 0.72 mm in 95 percent of all setups. The standard deviation of the rotational errors was at most 0.026° for all axes. For the second room Siemens implemented an improved approach strategy to the final couch positions. The 95 percent quantile of the 3d error could in this room be reduced to 0.53 mm; the standard deviation of the rotational errors was also at most 0.026°. Conclusions Robots are very flexible tools for patient positioning in six degrees of freedom. This study proved that the robots are able to achieve clinically acceptable accuracy in real patient setups, too.

The control of light-matter interaction at the quantum level usually requires coherent laser fields. But already an exchange of virtual photons with the electromagnetic vacuum field alone can lead to quantum coherences, which subsequently suppress spontaneous emission. We demonstrate such spontaneously generated coherences (SGC) in a large ensemble of nuclei operating in the x-ray regime, resonantly coupled to a common cavity environment. The observed SGC originates from two fundamentally different mechanisms related to cooperative emission and magnetically controlled anisotropy of the cavity vacuum. This approach opens new perspectives for quantum control, quantum state engineering and simulation of quantum many-body physics in an essentially decoherence-free setting., Comment: 5 pages, 3 figures

SummaryAn important aspect for the safety of the patient is the hygienic condition of employed instruments. These recommendations will help to achieve a reproducible standard on a high level in processing of MIS instruments. Instruments are classified into four categories. The processing cycle is divided into single steps and the requirements for the processing cycle are described.

The scaling of the number of Rydberg excitations in a laser-driven cloud of atoms with the interaction strength is found to be affected by the finite size of the system. The scaling predicted by a theoretical model is compared with results extracted from a numerical many-body simulation. We find that the numerically obtained scaling exponent in general does not agree with the analytical prediction. By individually testing the assumptions leading to the theoretical prediction using the results from the numerical analysis, we identify the origin of the deviations, and explain it as arising from the finite size of the system. Furthermore, finite-size effects in the pair correlation function $g^{(2)}$ are predicted. Finally, in larger ensembles, we find that the theoretical predictions and the numerical results agree, provided that the system is sufficiently homogeneous., 9 pages, 7 figures

The dynamics of a cloud of ultra-cold two-level atoms is studied at off-resonant laser driving to a Rydberg state. We find that resonant excitation channels lead to strongly peaked spatial correlations associated with the buildup of asymmetric excitation structures. These aggregates can extend over the entire ensemble volume, but are in general not localized relative to the system boundaries. The characteristic distances between neighboring excitations depend on the laser detuning and on the interaction potential. These properties lead to characteristic features in the spatial excitation density, the Mandel $Q$ parameter, and the total number of excitations. As an application an implementation of the three-atom CSWAP or Fredkin gate with Rydberg atoms is discussed. The gate not only exploits the Rydberg blockade, but also utilizes the special features of an asymmetric geometric arrangement of the three atoms. We show that continuous-wave off-resonant laser driving is sufficient to create the required spatial arrangement of atoms out of a homogeneous cloud., 8 pages, 7 figures

A model for the simulation of ensembles of laser-driven Rydberg-Rydberg interacting multi-level atoms is discussed. Our hybrid approach combines an exact two-body treatment of nearby atom pairs with an effective approximate treatment for spatially separated pairs. We propose an optimized evolution equation based only on the system steady state, and a time-independent Monte Carlo technique is used to efficiently determine this steady state. The hybrid model predicts features in the pair correlation function arising from multi-atom processes which existing models can only partially reproduce. Our interpretation of these features shows that higher-order correlations are relevant already at low densities. Finally, we analyze the performance of our model in the high-density case., Comment: significantly expanded and revised version (more observables, high-density regime); 9 pages, 8 figures