Conception and pilot testing of a self-management health application for patients with pollen-related allergic rhinitis and allergic asthma-the APOLLO app.

It has been shown that pollen information services are an important self-management tool for patients with pollen-related allergic rhinitis (AR) and allergic asthma (AA). This study aimed to design an online application for patients with AR and AA, which supports patients to better manage their disease as well as to evaluate the app and present the first results of the pilot study. The pollen data were obtained from the electronic pollen information network of Bavaria, Germany. Participants were asked to fill in their allergy-related complaints in the app over a 60-day period. Subsequently, the app was evaluated. Indices and diagrams visualized the participants' individual complaints as well as the daily pollen concentration in the air. In order to motivate participants to complete the app on a daily basis, we used elements of gamification. Two thirds of the participants (N = 46) reported feeling better informed about pollen counts and their allergy when using the app. The app's simple and comprehensible design was rated positively. More than 80% of the participants would recommend the app to their family and friends. The app can be a tool for patients with AR and AA to better understand their disease.

A precise and simple isodose-volume-based verification method for HDR and LDR brachytherapy plans.

PURPOSE: The American Association of Physicists in Medicine (AAPM) code of practice for brachytherapy physics recommends performing an independent treatment time calculation. For this we implemented an easy to use isodose-based verification method for HDR (high-dose-rate) and LDR (low-dose-rate) brachytherapy plans. MATERIAL AND METHODS: Dose-volume-based methods have been developed for Ir-192-based high-dose-rate (HDR) and I-125 prostate low-dose-rate (LDR) brachytherapy. They allow checking the integral dwell time or activity when the volume of a suitable isodose is known. The verification method was validated for 55 clinical HDR and 243 clinical LDR plans. RESULTS: For HDR brachytherapy, the mean absolute difference between the estimated and calculated integral dwell time was 0.8% ± 1.0% (n = 30) with a single-source path and 2.7% ± 1.1% (n = 25) for multiple source paths. The corresponding value for LDR brachytherapy was 1.8% ± 2.0% (n = 243). In HDR brachytherapy, the verification method depends slightly on the plan class when considering one or more than one source paths. Good agreement between the estimated and calculated integral dwell times was obtained based on the 2 Gy isodose. Unlike HDR brachytherapy, the parameters used in the verification method for LDR brachytherapy plan verification strongly depend on the type of seed distribution. So, we recommend using an isodose at the prescribed dose for prostate HDR therapy. CONCLUSIONS: Isodose-based verification methods are precise, do not presuppose dedicated tools, and are simple to implement in clinical practice.

Threshold-dependent iodine imaging and spectral separation in a whole-body photon-counting CT system.

OBJECTIVE: To evaluate the dual-energy (DE) performance and spectral separation with respect to iodine imaging in a photon-counting CT (PCCT) and compare it to dual-source CT (DSCT) DE imaging. METHODS: A semi-anthropomorphic phantom extendable with fat rings equipped with iodine vials is measured in an experimental PCCT. The system comprises a PC detector with two energy bins (20 keV, T) and (T, eU) with threshold T and tube voltage U. Measurements using the PCCT are performed at all available tube voltages (80 to 140 kV) and threshold settings (50-90 keV). Further measurements are performed using a conventional energy-integrating DSCT. Spectral separation is quantified as the relative contrast media ratio R between the energy bins and low/high images. Image noise and dose-normalized contrast-to-noise ratio (CNRD) are evaluated in resulting iodine images. All results are validated in a post-mortem angiography study. RESULTS: R of the PC detector varies between 1.2 and 2.6 and increases with higher thresholds and higher tube voltage. Reference R of the EI DSCT is found as 2.20 on average overall phantoms. Maximum CNRD in iodine images is found for T = 60/65/70/70 keV for 80/100/120/140 kV. The highest CNRD of the PCCT is obtained using 140 kV and is decreasing with decreasing tube voltage. All results could be confirmed in the post-mortem angiography study. CONCLUSION: Intrinsically acquired DE data are able to provide iodine images similar to conventional DSCT. However, PCCT thresholds should be chosen with respect to tube voltage to maximize image quality in retrospectively derived image sets. KEY POINTS: • Photon-counting CT allows for the computation of iodine images with similar quality compared to conventional dual-source dual-energy CT. • Thresholds should be chosen as a function of the tube voltage to maximize iodine contrast-to-noise ratio in derived image sets. • Image quality of retrospectively computed image sets can be maximized using optimized threshold settings.

Photon-counting detectors in computed tomography: from quantum physics to clinical practice.

Over the last decade, a fundamentally new type of computed tomography (CT) detectors has proved its superior capabilities in both physical and preclinical evaluations and is now approaching the stage of clinical practice. These detectors are able to discriminate single photons and quantify their energy and are hence called photon-counting detectors. Among the promising benefits of this technology are improved radiation dose efficiency, increased contrast-to-noise ratio, reduced metal artifacts, improved spatial resolution, simultaneous multi-energy acquisitions, and the prospect of multi-phase imaging within a single acquisition using multiple contrast agents. Taking the conventional energy-integrating detectors as a reference, the authors demonstrate the technical principles of this new technology and provide phantom and patient images acquired by a whole-body photon-counting CT. These images serve as a basis for discussing the potential future of clinical CT.

Stacking-Dependent Spin Interactions in Pd/Fe Bilayers on Re(0001).

Using spin-polarized scanning tunneling microscopy and density functional theory, we have studied the magnetic properties of Pd/Fe atomic bilayers on Re(0001). Two kinds of magnetic ground states are discovered due to different types of stacking of the Pd adlayer on Fe/Re(0001). For fcc stacking of Pd on Fe/Re(0001), it is a spin spiral propagating along the close-packed (ΓK[over ¯]) direction with a period of about 0.9 nm, driven by frustrated exchange and Dzyaloshinskii-Moriya interactions. For the hcp stacking, the four-site four-spin interaction stabilizes an up-up-down-down state propagating perpendicular to the close-packed direction (along ΓM[over ¯]) with a period of about 1.0 nm. Our work shows how higher-order exchange interactions can be tuned at interfaces.

A semi-automated quantitative comparison of metal artifact reduction in photon-counting computed tomography by energy-selective thresholding.

An evaluation of energy thresholding and acquisition mode for metal artifact reduction in Photon-counting detector CT (PCD-CT) compared to conventional energy-integrating detector CT (EID-CT) was performed. Images of a hip prosthesis phantom placed in a water bath were acquired on a scanner with PCD-CT and EID-CT (tube potentials: 100, 120 and 140 kVp) and energy thresholds (above 55-75 keV) in Macro and Chess mode. Only high-energy threshold images (HTI) were used. Metal artifacts were quantified by a semi-automated segmentation algorithm, calculating artifact volumes, means and standard deviations of CT numbers. Images of a human cadaver with hip prosthesis were acquired on the PCD-CT in Macro mode as proof-of-concept. Images at 140 kVp showed less metal artifacts than 120 kVp or 100 kVp. HTI (70, 75 keV) had fewer artifacts than low energy thresholds (55, 60, 65 keV). Fewer artifacts were observed in the Macro-HTI (8.9-13.3%) for cortical bone compared to Chess-HTI (9.4-19.1%) and EID-CT (10.7-19.0%) whereas in bone marrow Chess-HTI (19.9-45.1%) showed less artifacts compared to Macro-HTI (21.9-38.3%) and EID-CT (36.4-54.9%). Noise for PCD-CT (56-81 HU) was higher than EID-CT (33-36 HU) irrespective of tube potential. High-energy thresholding could be used for metal artifact reduction in PCD-CT, but further investigation of acquisition modes depending on target structure is required.

Iodine contrast-to-noise ratio improvement at unit dose and contrast media volume reduction in whole-body photon-counting CT.

PURPOSE: To assess the dose-normalized iodine contrast-to-noise-ratio (CNRD) improvement and contrast media reduction potential obtained with photon-counting (PC) CT compared to conventional energy-integrating (EI) CT as a function of patient size and tube voltage. METHOD: Images of a semi-anthropomorphic phantom of different sizes (small, medium, large) equipped with vials containing different iodine concentrations were acquired at the SOMATOM CounT prototype CT system using tube voltages of 80 kV-140 kV. CNRD is evaluated in reconstructions obtained using the EI detector, the PC detector using a single bin, and in reconstructions obtained by statistically optimally weighting acquisitions with two bins. Iodine CNRD improvements, potential dose reduction and the potential contrast media volume reduction are reported. RESULTS: In general, iodine CNRD improvement increases with increasing tube voltage for all patient sizes. In particular, if only one energy bin is used, the CNRD improvement is up to 30 % (small: 10 %, medium: 18 %, large: 30 %) and up to 37 % if an optimal weighting of two bins is performed (small: 13 %, medium: 25 %, large: 37 %) which is equivalent to the potential contrast media volume reduction. The improved iodine CNRD of PC compared to EI may allow for a potential radiation dose reduction of up to 46 %. CONCLUSIONS: All patients' iodine contrast at given x-ray dose, and particularly medium and large sized patients acquired at higher tube voltages, may benefit from photon-counting CT. The iodine contrast improvement can be used to reduce patient dose or to reduce the amount of contrast agent that is administered.

Clinical relevance of colonization with antimicrobial-resistant bacteria (AMRB) and methicillin susceptible Staphylococcus aureus (MSSA) for mothers during pregnancy.

PURPOSE: The impact of colonization with antimicrobial-resistant bacteria (AMRB) and methicillin-sensitive Staphylococcus aureus (MSSA) of healthy pregnant women is not described in detail in Germany. In this study, we screened for MSSA and AMRB, especially for methicillin-resistant S. aureus (MRSA) as well as extended-spectrum beta-lactamase (ESBL)-producing E. coli. Potential risk factors for colonization with AMRB/MSSA and the potential effects of colonization with these on the obstetric population were investigated. METHODS: From October 2013 until December 2015 pregnant women were screened before birth for colonization with AMRB/MSSA from the mammillae, nose, perianal and vaginal area. Before birth, the expectant mother was administered a standardized interview questionnaire by a trained interviewer. Data from the hospital admission records were also included. RESULTS: Samples from 651 pregnant women were analyzed. Colonization with MSSA was detected in 14.3% (n = 93), AMRB in 3.5% [(n = 23); MRSA: n = 3/ESBL: n = 20]. Significantly more colonization of AMRB/MSSA could be detected in women who had previously given birth compared to women who were nulliparous (p < 0.05). MSSA colonization was significantly associated with self-reported respiratory diseases during pregnancy (p < 0.05), but AMRB/MSSA colonization was not statistically associated with other types of infection. CONCLUSION: Our results demonstrate a low overall rate of colonization with AMRB/MSSA, as well as a low percentage of colonized pregnant women who developed infections. Multiparous women are at higher risk for colonization with MSSA/MRSA or ESBL. Because the prevalence of AMRB/MSSA is low, this study suggests that general screening of pregnant women without risk factors is not recommended.

Residential crowding and asthma in preschool children, a cross-sectional study

Background: Asthma is the most common chronic disease in children, and associations with crowding have been reported. The aim of this study was to explore possible associations of crowding with asthma in children. Methods: Seven cross-sectional surveys with preschool children were conducted within the framework of the health monitoring units in Bavaria, Germany, from 2004 to 2014. Residential crowding was defined as habitation of more than one person per room or less than 20m2 living space per person. Logistic regression models examined temporal changes in crowding, applying the first survey as reference. The relationship between crowding and physician-diagnosed asthma, asthma defined by the International Study of Asthma and Allergies in Childhood (ISAAC) and asthma symptoms were analyzed. Results: Analyzing temporal changes of crowding rates did not reveal any differences over the years. However, the stratified descriptive analysis indicated a crowding increase in time in urban households where parents had a low education level (47.9% in 2004/05, 55.8% in 2014/15). No association was found between crowding and the variables "physician-diagnosed asthma" in 2014/15, "asthma defined by ISAAC" in 2014/15, or "wheezing" in 2014/15. A positive association with cough was identified in 2014/15 after adjusting for confounders (aOR = 1.42 [95% CI: 1.20-1.69]). Conclusions: In general, residential crowding did not change from 2004 to 2014; however, there seems to be a small upsurge for children with low-educated parents, living in urban areas over the years. A statistically significant association between crowding and cough was only found in the survey from 2014/15

No disponible

Author Correction: Enhanced skyrmion stability due to exchange frustration.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Fatal attack on a pedestrian by an escaped circus elephant.

We report the case of a 65-year-old man who was attacked and killed by a female elephant that had previously escaped from a nearby circus. According to a witness the man was lifted up by the tusks, flung into the air and stomped upon. At autopsy the body showed signs of severe blunt force trauma and impalement, including multiple lacerations of the skin, a crushed thorax, a spinal fracture and a fractured humerus. The spinal cord and the major abdominal vessels were severed. There have been very few elephant attacks in Europe; this is the first reported case in Germany.

Yoga in the workplace and health outcomes: a systematic review.

BACKGROUND: Health promotion in the workplace is intended to enhance employee health and well-being. Yoga programmes are easy to implement and have been effective in the management of various health conditions. AIMS: To assess the evidence regarding the effectiveness of yoga programmes at work. METHODS: A search of electronic databases of published studies up until the 1st of April 2017. Inclusion criteria for the systematic review were randomized controlled trials of adult employees and yoga in the workplace. Quality appraisal was carried out using the Cochrane Collaboration's tool for assessing risk of bias in randomized trials. RESULTS: Of 1343 papers identified, 13 studies met the inclusion criteria. Nine out of 13 trials were classified as having an unclear risk of bias. The overall effects of yoga on mental health outcomes were beneficial, mainly on stress. Most of the cardiovascular endpoints showed no differences between yoga and controls. Other outcomes reported positive effects of yoga or no change. CONCLUSIONS: The findings of this study suggest that yoga has a positive effect on health in the workplace, particularly in reducing stress, and no negative effects were reported in any of the randomized controlled trials. Further larger studies are required to confirm this.

Residential crowding and asthma in preschool children, a cross-sectional study.

BACKGROUND: Asthma is the most common chronic disease in children, and associations with crowding have been reported. The aim of this study was to explore possible associations of crowding with asthma in children. METHODS: Seven cross-sectional surveys with preschool children were conducted within the framework of the health monitoring units in Bavaria, Germany, from 2004 to 2014. Residential crowding was defined as habitation of more than one person per room or less than 20m2 living space per person. Logistic regression models examined temporal changes in crowding, applying the first survey as reference. The relationship between crowding and physician-diagnosed asthma, asthma defined by the International Study of Asthma and Allergies in Childhood (ISAAC) and asthma symptoms were analyzed. RESULTS: Analyzing temporal changes of crowding rates did not reveal any differences over the years. However, the stratified descriptive analysis indicated a crowding increase in time in urban households where parents had a low education level (47.9% in 2004/05, 55.8% in 2014/15). No association was found between crowding and the variables "physician-diagnosed asthma" in 2014/15, "asthma defined by ISAAC" in 2014/15, or "wheezing" in 2014/15. A positive association with cough was identified in 2014/15 after adjusting for confounders (aOR=1.42 [95% CI: 1.20-1.69]). CONCLUSIONS: In general, residential crowding did not change from 2004 to 2014; however, there seems to be a small upsurge for children with low-educated parents, living in urban areas over the years. A statistically significant association between crowding and cough was only found in the survey from 2014/15.

Enhanced skyrmion stability due to exchange frustration.

Skyrmions are localized, topologically non-trivial spin structures which have raised high hopes for future spintronic applications. A key issue is skyrmion stability with respect to annihilation into the ferromagnetic state. Energy barriers for this collapse have been calculated taking only nearest neighbor exchange interactions into account. Here, we demonstrate that exchange frustration can greatly enhance skyrmion stability. We focus on the prototypical film system Pd/Fe/Ir(111) and use an atomistic spin model parametrized from first-principles calculations. We show that energy barriers and critical fields of skyrmion collapse as well as skyrmion lifetimes are drastically enhanced due to frustrated exchange and that antiskyrmions are metastable. In contrast an effective nearest-neighbor exchange model can only account for equilibrium properties of skyrmions such as their magnetic field dependent profile or the zero temperature phase diagram. Our work shows that frustration of long range exchange interactions - a typical feature in itinerant electron magnets - is a route towards enhanced skyrmion stability even in systems with a ferromagnetic ground state.

Designing a molecular magnetic button based on 4d and 5d transition-metal phthalocyanines.

The field of molecular spintronics exploits the properties of organic molecules possessing a magnetic moment, either native in the form of radicals or induced by the insertion of transition metal magnetic ions. To realize logic or storage molecular spin-tronics devices, molecules with stable different magnetic states should be deposited on a substrate, and switching between the states controllably achieved. By means of a first-principles calculations, we have devised a functional molecule exhibiting different magnetic states upon structural changes induced by current injection. We investigate the prototypical case of non-planar M-Phthalocyanine (MPc), where M is a transition-metal ion belonging to the 4d and 5d series. We find that for ZrPc and HfPc deposited on a graphene decorated Ni(111) substrate, two different structural conformations could be stabilized, for which the molecules attain different magnetic states depending on the position of the M ion - whether above the Pc or between the Pc and the substrate -, acting therefore as molecular magnetic button. Our work indicates an intuitive way to engineer a magnetic molecular switch with tailored properties, starting from the knowledge of the basic atomic properties of elements and surfaces.

Intraoperative Intermittent Blocking of the Common Iliac Arteries in Cases of Placenta Percreta without the Use of Fluoroscopy.

Background: The number of patients with placenta accreta, percreta and increta is increasing. The morbidity and mortality are higher mostly due to hemorrhage. Therefore, new methods to reduce the risk of severe bleeding are necessary. Methods: Three patients were treated in collaboration by obstetricians, urologists, anesthesiologists, and radiologists. An MRI of the pelvis was performed and the diameters and lengths of the iliac arteries were measured to avoid fluoroscopy during the preoperative placement of catheter balloons into the iliac arteries. During the operational procedure the balloons were inflated and deflated depending on the operative site and the occurrence of bleeding. Results: In comparison to the literature, severe bleeding was clearly reduced. No complications of the intervention were observed. Conclusion: The presented method to reduce severe bleeding might represent significant progress in the management of abnormal placenta implantation. Nevertheless, further controlled studies are needed in order to establish evidence-based recommendations. Key Points: • Reduction of perioperative hemorrhage in cases of placenta accreta, percreta, and increta.• A preinterventional MRI of the pelvis allows measurement of the illiac arteries so that the fetus is not exposed to radiation.• The short occlusion time (under the nominal pressure of the balloon) of the common iliac arteries reduced interventional complications. Citation Format: • Heinze S, Filsinger B, Kastenholz G et al. Intraoperative Intermittent Blocking of the Common Iliac Arteries in Cases of Placenta Percreta without the Use of Fluoroscopy. Fortschr Röntgenstr 2016; 188: 1151 - 1155.

Engineering skyrmions in transition-metal multilayers for spintronics.

Magnetic skyrmions are localized, topologically protected spin structures that have been proposed for storing or processing information due to their intriguing dynamical and transport properties. Important in terms of applications is the recent discovery of interface stabilized skyrmions as evidenced in ultra-thin transition-metal films. However, so far only skyrmions at interfaces with a single atomic layer of a magnetic material were reported, which greatly limits their potential for application in devices. Here we predict the emergence of skyrmions in [4d/Fe2/5d]n multilayers, that is, structures composed of Fe biatomic layers sandwiched between 4d and 5d transition-metal layers. In these composite structures, the exchange and the Dzyaloshinskii-Moriya interactions that control skyrmion formation can be tuned separately by the two interfaces. This allows engineering skyrmions as shown based on density functional theory and spin dynamics simulations.

Ballistic Anisotropic Magnetoresistance of Single-Atom Contacts.

Anisotropic magnetoresistance, that is, the sensitivity of the electrical resistance of magnetic materials on the magnetization direction, is expected to be strongly enhanced in ballistic transport through nanoscale junctions. However, unambiguous experimental evidence of this effect is difficult to achieve. We utilize single-atom junctions to measure this ballistic anisotropic magnetoresistance (AMR). Single Co and Ir atoms are deposited on domains and domain walls of ferromagnetic Fe layers on W(110) to control their magnetization directions. They are contacted with nonmagnetic tips in a low-temperature scanning tunneling microscope to measure the junction conductances. Large changes of the magnetoresistance occur from the tunneling to the ballistic regime due to the competition of localized and delocalized d-orbitals, which are differently affected by spin-orbit coupling. This work shows that engineering the AMR at the single atom level is feasible.

Renaissance of criticism on the concept of brain death--the role of legal medicine in the context of the interdisciplinary discussion.

BACKGROUND: In the practice of legal medicine in Germany, the assessment of brain death is of minor importance and attracts little attention. However, since several years, international criticism on the concept of brain death has culminated. By reviewing literature and the results of a questionnaire distributed among the participants of the 93rd Annual Congress of the Germany Society of Legal Medicine, the state of knowledge and the current views on brain death were evaluated. MATERIALS AND METHODS: Literature search of recent publications regarding brain death was performed (PubMed database, references of legal medicine, Report of the President's Council on Bioethics, USA 2008). A questionnaire was developed and distributed among the participants of the Congress. RESULTS: The assumption that individual and brain death are synonymous is criticized. Internationally, there are trends to harmonize the very different clinical criteria to assess brain death. The diagnostic advantage of novel techniques such as CT angiography is controversially discussed. It becomes apparent that procedures which record the blood flow and perfusion of the brain will be applied more in the future. Regrettably, these developments are not described in the literature of legal medicine. Moreover, among German forensic scientists, different views concerning brain death exist. The majority favors its equivalent treatment with individual death. The thanatological background can be improved concerning certain aspects of brain death as well as its legal implications. CONCLUSION: Teaching and research in legal medicine should include the subject brain death. Expertise in forensic science may contribute to the interdisciplinary discussion on brain death. The transfer of actual knowledge, also on disputed ethical aspects of thanatology, to physicians of all disciplines is of great importance.

Tunneling anisotropic magnetoresistance at the single-atom limit.

The tunneling anisotropic magnetoresistance (TAMR) of single Co atoms adsorbed on a double-layer Fe film on W(110) is observed by scanning tunneling spectroscopy. Without applying an external magnetic field the TAMR is found by comparing spectra of atoms that are adsorbed on the domains and domain walls of the Fe film. The TAMR can be as large as 12% and repeatedly changes sign as a function of bias voltage. First-principles calculations show that the hybridization between Co d states of different orbital symmetries depends on the magnetization direction via spin-orbit coupling. This leads to an anisotropy of the density of states and thus induces a TAMR.