Publications by authors named "Thomas Schäfer"

67 Publications

How to read between the lines of electronic spectra: the diagnostics of fluctuations in strongly correlated electron systems.

J Phys Condens Matter 2021 Mar 2. Epub 2021 Mar 2.

Institut für Festkörperphysik, Vienna University of Technology, Wiedner Hauptstraße 8-10, Vienna, 1040, AUSTRIA.

While calculations and measurements of single-particle spectral properties often offer the most direct route to study correlated electron systems, the underlying physics may remain quite elusive, if information at higher particle levels is not explicitly included. Here, we present a comprehensive overview of the different approaches, which have been recently developed and applied to identify the dominant two-particle scattering processes controlling the shape of the one-particle spectral functions and, in some cases, of the physical response of the system. In particular, we will discuss the underlying general idea, the common threads and the specific peculiarities of all the proposed approaches. While all of them rely onto a selective analysis of the Schwinger-Dyson (or the Bethe-Salpeter) equation, the methodological differences originate from the specific two-particle vertex functions to be computed and decomposed. Finally, we illustrate the potential strength of these methodologies by means of their applications the two-dimensional Hubbard model, and we provide an outlook over the future perspective and developments of this route for understanding the physics of correlated electrons.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1088/1361-648X/abeb44DOI Listing
March 2021

Seasonal Influenza Vaccine in Pregnant Women: Views and Experiences of Obstetrician-Gynecologists.

J Womens Health (Larchmt) 2021 Feb 2. Epub 2021 Feb 2.

Department of Health Policy and Management, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.

Seasonal influenza vaccination rates among pregnant women remain well below the Healthy People 2020 target of 80%. Obstetrician-gynecologist (OB/GYN) recommendations are a critical means of encouraging pregnant women to get vaccinated, but there are limited data about their views. A nationally representative survey of 506 practicing OB/GYNs was completed between October 26, 2015, and May 8, 2016. Analyses included univariate distributions and comparisons based on age, size of practice, and academic affiliation using all-pairs, dependent -tests. A majority of OB/GYNs report they "strongly recommend" seasonal influenza vaccination for their pregnant patients in the first (79%) or second and third trimesters (81%). Among those who do not strongly recommend the flu vaccine in the first trimester, many say this is because of their own concerns (28%) or their patients' concerns (44%) about safety. Older OB/GYNs, those in smaller practices, and those without academic affiliation were less likely to recommend the vaccine and more likely to have safety concerns. For example, 72% of those age 60+ strongly recommended the vaccine in the second and third trimester, compared with 86% of those ages 30-44 and 83% of those ages 45-59 ( < 0.05 for all comparisons). OB/GYNs across the country largely support seasonal flu vaccination among pregnant women. Nonetheless, safety is a concern for them and their patients. Outreach to support clinician decisions and conversations with pregnant patients may be most needed among older physicians, those in smaller practices, and those without academic affiliation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/jwh.2020.8700DOI Listing
February 2021

Seasonal Influenza Vaccine in Pregnant Women: Views and Experiences of Obstetrician-Gynecologists.

J Womens Health (Larchmt) 2021 Feb 2. Epub 2021 Feb 2.

Department of Health Policy and Management, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.

Seasonal influenza vaccination rates among pregnant women remain well below the Healthy People 2020 target of 80%. Obstetrician-gynecologist (OB/GYN) recommendations are a critical means of encouraging pregnant women to get vaccinated, but there are limited data about their views. A nationally representative survey of 506 practicing OB/GYNs was completed between October 26, 2015, and May 8, 2016. Analyses included univariate distributions and comparisons based on age, size of practice, and academic affiliation using all-pairs, dependent -tests. A majority of OB/GYNs report they "strongly recommend" seasonal influenza vaccination for their pregnant patients in the first (79%) or second and third trimesters (81%). Among those who do not strongly recommend the flu vaccine in the first trimester, many say this is because of their own concerns (28%) or their patients' concerns (44%) about safety. Older OB/GYNs, those in smaller practices, and those without academic affiliation were less likely to recommend the vaccine and more likely to have safety concerns. For example, 72% of those age 60+ strongly recommended the vaccine in the second and third trimester, compared with 86% of those ages 30-44 and 83% of those ages 45-59 ( < 0.05 for all comparisons). OB/GYNs across the country largely support seasonal flu vaccination among pregnant women. Nonetheless, safety is a concern for them and their patients. Outreach to support clinician decisions and conversations with pregnant patients may be most needed among older physicians, those in smaller practices, and those without academic affiliation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/jwh.2020.8700DOI Listing
February 2021

Stem cell donor registry activities during the COVID-19 pandemic: a field report by DKMS.

Bone Marrow Transplant 2020 Nov 20. Epub 2020 Nov 20.

DKMS, Tübingen, Germany.

The COVID-19 pandemic has serious implications also for patients with other diseases. Here, we describe the effects of the pandemic on unrelated hematopoietic stem cell donation and transplantation from the perspective of DKMS, a large international donor registry. Especially, we cover the development of PBSC and bone marrow collection figures, donor management including Health and Availability Check (HAC), transport and cryopreservation of stem cell products, donor recruitment and business continuity measures. The total number of stem cell products provided declined by around 15% during the crisis with a particularly strong decrease in bone marrow products. We modified donor management processes to ensure donor and product safety. HAC instead of confirmatory typing was helpful especially in countries with strict lockdowns. New transport modes were developed so that stem cell products could be safely delivered despite COVID-19-related travel restrictions. Cryopreservation of stem cell products became the new temporary standard during the pandemic to minimize risks related to transport logistics and donor availability. However, many products from unrelated donors will never be transfused. DKMS discontinued public offline donor recruitment, leading to a 40% decline in new donors during the crisis. Most DKMS employees worked from home to ensure business continuity during the crisis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41409-020-01138-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7677905PMC
November 2020

Fluorescent bicolour sensor for low-background neutrinoless double β decay experiments.

Nature 2020 07 22;583(7814):48-54. Epub 2020 Jun 22.

Donostia International Physics Center (DIPC), San Sebastián/Donostia, Spain.

Observation of the neutrinoless double β decay is the only practical way to establish that neutrinos are their own antiparticles. Because of the small masses of neutrinos, the lifetime of neutrinoless double β decay is expected to be at least ten orders of magnitude greater than the typical lifetimes of natural radioactive chains, which can mimic the experimental signature of neutrinoless double β decay. The most robust identification of neutrinoless double β decay requires the definition of a signature signal-such as the observation of the daughter atom in the decay-that cannot be generated by radioactive backgrounds, as well as excellent energy resolution. In particular, the neutrinoless double β decay of Xe could be established by detecting the daughter atom, Ba, in its doubly ionized state. Here we demonstrate an important step towards a 'barium-tagging' experiment, which identifies double β decay through the detection of a single Ba ion. We propose a fluorescent bicolour indicator as the core of a sensor that can detect single Ba ions in a high-pressure xenon gas detector. In a sensor made of a monolayer of such indicators, the Ba dication would be captured by one of the molecules and generate a Ba-coordinated species with distinct photophysical properties. The presence of such a single Ba-coordinated indicator would be revealed by its response to repeated interrogation with a laser system, enabling the development of a sensor able to detect single Ba ions in high-pressure xenon gas detectors for barium-tagging experiments.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41586-020-2431-5DOI Listing
July 2020

Sb- and Bi-based coordination polymers with N-donor ligands with and without lone-pair effects and their photoluminescence properties.

Dalton Trans 2020 Apr;49(15):4904-4913

Institute of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074 Würzburg, Germany and Institute of Inorganic and Analytical Chemistry, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 17, 35392 Giessen, Germany. and Center for Materials Research (LAMA), Justus-Liebig-University Giessen, Heinrich-Buff-Ring 16, 35392 Giessen, Germany.

Fifteen new sublimable Sb- and Bi-based chlorido, bromido and iodido coordination polymers (CPs) with linear bispyridyl ligands are presented in this work and compared in terms of their crystal structures and photoluminescence properties. The Sb-CPs occur in two structural motifs: 1∞[Sb2X6(L)2] (X: Cl (a), Br (b), I (c); L: 1,2-bis(4-pyridyl)ethylene (bpe) (1), 1,2-bis(4-pyridyl)ethane (bpa) (2), 4,4'-bipyridine (bipy) (X: Br, I; 3)) with two polymorphs showing negligible stereochemical demand of the lone-pair and 1∞[SbCl3(bipy)] (3a) featuring a stereochemically active lone pair with significant 5p-contribution at SbIII. This is accompanied by differences in the coordination polyhedra being octahedral for high s-character, whereas a high p-character of the lone pair results in a square pyramid as the coordination sphere. The Bi-CPs are represented by the general formula 1∞[Bi2X6(L)2] (X: Cl (a), Br (b), I (c); L: 1,2-bis(4-pyridyl)ethylene (bpe) (4), 1,2-bis(4-pyridyl)ethane (bpa) (5)) and thus show no significant 6p-character of the lone pairs. For examining the parallels and differences between the SbIII- and BiIII-CPs, both are compared in terms of structures and luminescence properties, as well as with related literature known CPs. Altogether, this comparison of structures and properties allows for gaining new insights into the photoluminescence mechanisms of the Sb and Bi-containing CPs. For the first time, distinct hints on the participation of inter-valence charge transfer transitions in E3+-pairs (E: Sb, Bi) were observed for the Sb- and Bi-containing coordination polymers constructed from N-donor ligands.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0dt00265hDOI Listing
April 2020

Immunogenetics in stem cell donor registry work: The DKMS example (Part 2).

Int J Immunogenet 2020 Apr 7;47(2):139-148. Epub 2020 Feb 7.

Clinical Trials Unit, DKMS, Dresden, Germany.

DKMS is a leading stem cell donor registry with more than 9 million donors. Donor registry activities share many touch points with topics from immunogenetics or population genetics. In this two-part review article, we deal with these aspects of donor registry work by using the example of DKMS. In the second part of the review, we focus on donor typing of non-HLA genes, the impact of donor age, gender and CMV serostatus on donation probabilities, the identification of novel HLA, KIR and MIC alleles by high-throughput donor typing, the activities of the Collaborative Biobank and pharmacogenetics in the donor registry context.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/iji.12479DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7079094PMC
April 2020

Linking Film Structure and Mechanical Properties in Nanocomposite Films Formed from Dispersions of Cellulose Nanocrystals and Acrylic Latexes.

Langmuir 2020 Mar 19;36(8):2052-2062. Epub 2020 Feb 19.

POLYMAT and Departamento de Química Aplicada, Facultad de Ciencias Químicas, University of the Basque Country UPV/EHU, Joxe Mari Korta Zentroa, Tolosa Hiribidea 72, Donostia-San Sebastián 20018, Spain.

Cellulose nanocrystals (CNCs) are unique, lightweight materials that possess high elastic modulus and tensile strength, making them of great interest in the formation of nanocomposite materials. However, efficient design of the composite material is essential in translating the mechanical properties of the individual CNCs into the nanocomposite film. In this work, we demonstrate the formation of structured CNC/acrylic dispersions by physical blending of the anionic CNCs with charged acrylic latex particles. By blending with large cationic latex particles, the CNCs adsorbed onto the acrylic latex surface while blending with small latex particles led to the inverse structure. Films were cast from these dispersions and the physical properties were compared with the aim of understanding the influence of the initial structure of the hybrid dispersion on the structure of the final film. A significant difference in the mechanical properties was observed based on the position of the CNCs in the initial dispersion. Adsorption of latex particles onto the CNC surface led to a random distribution of nonconnected CNCs, which contributed little to improving the Young's modulus, while adsorption of CNC onto the latex led to a honeycomb CNC network and a large increase in the Young's modulus. This work underlines the importance of particle structure on the structure and mechanical properties of nanostructured films.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.langmuir.9b03861DOI Listing
March 2020

Immunogenetics in stem cell donor registry work: The DKMS example (Part 1).

Int J Immunogenet 2020 Feb 6;47(1):13-23. Epub 2020 Jan 6.

DKMS, Clinical Trials Unit, Dresden, Germany.

Currently, stem cell donor registries include more than 35 million potential donors worldwide to provide HLA-matched stem cell products for patients in need of an unrelated donor transplant. DKMS is a leading stem cell donor registry with more than 9 million donors from Germany, Poland, the United States, the United Kingdom, India and Chile. DKMS donors have donated hematopoietic stem cells more than 80,000 times. Many aspects of donor registry work are closely related to topics from immunogenetics or population genetics. In this two-part review article, we describe, analyse and discuss these areas of donor registry work by using the example of DKMS. Part 1 of the review gives a general overview on DKMS and includes typical donor registry activities with special focus on the HLA system: high-throughput HLA typing of potential stem cell donors, HLA haplotype frequencies and resulting matching probabilities, and donor file optimization with regard to HLA diversity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/iji.12471DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7003907PMC
February 2020

PROMISE: A Model of Insight and Equanimity as the Key Effects of Mindfulness Meditation.

Front Psychol 2019 22;10:2389. Epub 2019 Oct 22.

Department of Psychology, MSB Medical School Berlin, Berlin, Germany.

In a comprehensive meta-analysis on the effects of mindfulness meditation, Eberth and Sedlmeier (2012) identified a multitude of positive effects that covered a wide range of psychological variables, such as heightened mindfulness as measured through contemporary mindfulness scales, reduced negative emotions, increased positive emotions, changes in self-concept, enhanced attention, perception, and wellbeing, improved interpersonal abilities, and a reduction of negative personality traits. The present research aimed at developing and testing a comprehensive model explaining the wide range of mindfulness meditation effects and their temporal and causal relationships. In Study 1, interviews with meditators at different levels of experience were analyzed using a grounded theory procedure. The resulting model was triangulated and refined by concepts from both Western research and ancient Buddhist scriptures. The model developed highlights (reduction in emotional reactivity) and (alteration of cognitions) as the two key effects of mindfulness meditation that eventually lead to increased wellbeing. The model was pilot-tested with a large sample of meditators and non-meditators in Study 2. Data showed an acceptable fit with the model and indicated that meditators and non-meditators score significantly differently on the model's core categories.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2019.02389DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6817944PMC
October 2019

Views and Experiences of Travelers from US States to Zika-Affected Areas.

Health Secur 2019 Jul/Aug;17(4):307-323

Thomas Schafer is Project Director, National Public Health Information Coalition, Marietta, GA.

Travelers to areas with Zika virus transmission are at risk of infection and of transmitting the virus after returning home. While protective behaviors during and after travel can reduce these risks, information about traveler practices or underlying views is limited. We examined these issues using data from the first representative poll of travelers from US states to Zika-affected areas, including US territories and Miami, Florida, conducted December 1 to 23, 2016. We analyzed results among all travelers ( = 1,285) and 2 subgroups at risk for pregnancy-related complications: (1) travelers in households where someone was pregnant or considering pregnancy ( = 72), and (2) other travelers of reproductive age ( = 631). We also examined results among those with different levels of awareness and knowledge about Zika virus. Results show that in households where someone was pregnant or considering pregnancy, awareness of Zika in the destination, concern about infection, and adoption of protective behaviors was relatively high. That said, sizable shares of travelers as a whole did not know information about asymptomatic and sexual transmission or post-travel behaviors. Further, concern about getting infected during travel was low among travelers as a whole, including other travelers of reproductive age. Few travelers consistently adopted protective behaviors during or after travel. Even among travelers who were aware of Zika in their destination and knew how to protect themselves, adoption of protective behaviors was only slightly higher. Findings from this poll suggest communications may be more effective if tailored to different levels of true and perceived risk. To address gaps in knowledge about transmission and post-travel protective behaviors, messaging should include facts and acknowledge the complexities of novel information and social context. Consideration should also be given to emphasizing other benefits of Zika protective behaviors or prioritizing behaviors that are most feasible.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/hs.2019.0008DOI Listing
May 2020

Vitamin D Deficiency in Patients With Idiopathic and Traumatic Osteochondritis Dissecans of the Talus.

Foot Ankle Int 2019 Nov 2;40(11):1309-1318. Epub 2019 Aug 2.

Orthopedic Center for Musculoskeletal Research, University of Wuerzburg, Wuerzburg, Germany.

Background: Low vitamin D levels are common in patients with foot and ankle disorders. We have previously demonstrated that juveniles diagnosed with osteochondritis dissecans (OCD) have a high prevalence of vitamin D deficiency. Moreover, there is evidence that OCD might be related to vitamin D deficiency in general. However, whether or not hypovitaminosis D is associated with OCD of the talus has yet to be elucidated.

Methods: The aim of this study was to determine serum vitamin D levels [25(OH)D] of patients diagnosed with traumatic and idiopathic OCD of the talus. The vitamin D status of patients was measured and correlated to age, sex, season, etiology, laterality, degree of disease, and nicotine abuse. Moreover, parathyroid hormone and serum calcium levels of patients were obtained to assess for severe vitamin D deficiency and secondary hyperparathyroidism. Between January 2015 and December 2017, 65 patients with a mean age of 38.9 years and a total of 68 lesions were identified.

Results: In total, 75.4% of patients had low vitamin D levels with a mean overall 25(OH)D level of 24.2 ng/mL. Specifically, 35.4% of patients were vitamin D deficient; another 40% were vitamin D insufficient, and only 24.6% of patients presented with sufficient vitamin D levels. Statistical analysis showed no significant difference comparing vitamin D levels of patients with idiopathic OCD to patients with traumatic OCD.

Conclusion: We could not find any significant differences in the vitamin D status of patients with OCD of the talus compared with patients with foot and ankle disorders in general. However, we found that vitamin D deficiency was frequent in patients presenting with traumatic and idiopathic OCD of the talus. We believe it might be beneficial to routinely assess and treat the vitamin D status of patients.

Level Of Evidence: Level III, retrospective comparative study.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1071100719864325DOI Listing
November 2019

The Meaningfulness of Effect Sizes in Psychological Research: Differences Between Sub-Disciplines and the Impact of Potential Biases.

Front Psychol 2019 11;10:813. Epub 2019 Apr 11.

Department of Psychology, Chemnitz University of Technology, Chemnitz, Germany.

Effect sizes are the currency of psychological research. They quantify the results of a study to answer the research question and are used to calculate statistical power. The interpretation of effect sizes-when is an effect small, medium, or large?-has been guided by the recommendations Jacob Cohen gave in his pioneering writings starting in 1962: Either compare an effect with the effects found in past research or use certain conventional benchmarks. The present analysis shows that neither of these recommendations is currently applicable. From past publications without pre-registration, 900 effects were randomly drawn and compared with 93 effects from publications with pre-registration, revealing a large difference: Effects from the former (median = 0.36) were much larger than effects from the latter (median = 0.16). That is, certain biases, such as publication bias or questionable research practices, have caused a dramatic inflation in published effects, making it difficult to compare an actual effect with the real population effects (as these are unknown). In addition, there were very large differences in the mean effects between psychological sub-disciplines and between different study designs, making it impossible to apply any global benchmarks. Many more pre-registered studies are needed in the future to derive a reliable picture of real population effects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2019.00813DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6470248PMC
April 2019

Properties of perhalogenated {closo-B} and {closo-B} multiply charged anions and a critical comparison with {closo-B} in the gas and the condensed phase.

Phys Chem Chem Phys 2019 Mar;21(11):5903-5915

Physical Sciences Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MSIN K8-88, Richland, WA 99352, USA.

closo-Borate anions [closo-BnXn]2- are part of the most famous textbook examples of polyhedral compounds. Substantial differences in their reactivity and interactions with other compounds depending on the substituent X and cluster size n have been recognized, which favor specific closo-borates for different applications in cancer treatment, chemical synthesis, and materials science. Surprisingly, a fundamental understanding of the molecular properties underlying these differences is lacking. Here, we report our study comparing the electronic structure and reactivity of closo-borate anions [closo-BnXn]2- (X = Cl, Br, I, n = 10, 11, 12 in all combinations) in the gas phase and in solution. We investigated the free dianions and the ion pairs [nBu4N]+[closo-BnXn]2- by gas phase anion photoelectron spectroscopy accompanied by theoretical investigations. Strong similarities in electronic structures for n = 10 and 11 were observed, while n = 12 clusters were different. A systematic picture of the development in electronic stability along the dimension X is derived. Collision induced dissociation shows that fragmentation of the free dianions is mainly dependent on the substituent X and gives access to a large variety of boron-rich molecular ions. Fragmentation of the ion pair depends strongly on n. The results reflect the high chemical stability of clusters with n = 10 and 12, while those with n = 11 are much more prone to dissociation. We bridge our study to the condensed phase by performing comparative electrochemistry and reactivity studies on closo-borates in solution. The trends found at the molecular level are also reflected in the condensed-phase properties. We discuss how the gas phase values allow evaluation of the influence of the condensed phase on the electronic stability of closo-borates. A synthetic method via an oxidation/chlorination reaction yielding [closo-B10Cl10]2- from highly chlorinated {closo-B11} clusters is introduced, which underlines the intrinsically high reactivity of the {closo-B11} cage.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c8cp05313hDOI Listing
March 2019

Statistical power in two-level models: A tutorial based on Monte Carlo simulation.

Psychol Methods 2019 Feb 27;24(1):1-19. Epub 2018 Sep 27.

Department of Psychology, Chemnitz University of Technology.

The estimation of power in two-level models used to analyze data that are hierarchically structured is particularly complex because the outcome contains variance at two levels that is regressed on predictors at two levels. Methods for the estimation of power in two-level models have been based on formulas and Monte Carlo simulation. We provide a hands-on tutorial illustrating how a priori and post hoc power analyses for the most frequently used two-level models are conducted. We describe how a population model for the power analysis can be specified by using standardized input parameters and how the power analysis is implemented in SIMR, a very flexible power estimation method based on Monte Carlo simulation. Finally, we provide case-sensitive rules of thumb for deriving sufficient sample sizes as well as minimum detectable effect sizes that yield a power ≥ .80 for the effects and input parameters most frequently analyzed by psychologists. For medium variance components, the results indicate that with lower level (L1) sample sizes up to 30 and higher level (L2) sample sizes up to 200, medium and large fixed effects can be detected. However, small L2 direct- or cross-level interaction effects cannot be detected with up to 200 clusters. The tutorial and guidelines should be of help to researchers dealing with multilevel study designs such as individuals clustered within groups or repeated measurements clustered within individuals. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1037/met0000195DOI Listing
February 2019

Overcoming safety challenges in CO therapy - Extracorporeal CO delivery under precise feedback control of systemic carboxyhemoglobin levels.

J Control Release 2018 06 12;279:336-344. Epub 2018 Apr 12.

Institute for Pharmacy and Food Chemistry, University of Würzburg, Germany. Electronic address:

Carbon monoxide (CO) has demonstrated therapeutic potential in multiple inflammatory conditions including intensive care applications such as organ transplantation or sepsis. Approaches to translate these findings into future therapies, however, have been challenged by multiple hurdles including handling and toxicity issues associated with systemic CO delivery. Here, we describe a membrane-controlled Extracorporeal Carbon Monoxide Release System (ECCORS) for easy implementation into Extracorporeal Membrane Oxygenation (ECMO) setups, which are being used to treat cardiac and respiratory diseases in various intensive care applications. Functionalities of the ECCORS were investigated in a pig model of veno-arterial ECMO. By precisely controlling CO generation and delivery as a function of systemic carboxyhemoglobin levels, the system allows for an immediate onset of therapeutic CO-levels while preventing CO-toxicity. Systemic carboxyhemoglobin levels were profiled in real-time by monitoring exhaled CO levels as well as by pulse oximetry, enabling self-contained and automatic feedback control of CO generation within ECCORS. Machine learning based mathematical modeling was performed to increase the predictive power of this approach, laying foundation for high precision systemic CO delivery concepts of tomorrow.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jconrel.2018.04.017DOI Listing
June 2018

Ambient-air ozonolysis of triglycerides in aged fingerprint residues.

Analyst 2018 Feb;143(5):1197-1209

Forensic Science Institute, Federal Criminal Police Office, 65173 Wiesbaden, Germany.

In forensic science, reconstructing the timing of events occurring during a criminal offense is of great importance. In some cases, the time when particular evidence was left on a crime scene is a critical matter. The ability to estimate the fingerprint age would raise the evidentiary value of fingerprints tremendously. For this purpose the most promising approach is the analysis of changes in the chemical compositions of fingerprint residues in the course of aging. The focus of our study is the identification of human specific compounds in fingerprint residues, characterized by a significant aging behavior that could analytically be used for the age determination of fingerprints in future. The first challenge is the sensitive detection of trace amounts of relevant human specific fingerprint compounds. Highly sensitive LC-MS methods were developed for the reliable structure identification of unsaturated triglycerides and their natural degradation products in order to proof the aging mechanism that takes place in fingerprint residues. Thus our results build the fundamental basis for further forensic method development and potential application in forensic investigation. Ozonolysis was found to be one of the major lipid degradation pathways in fingerprint residues in ambient air. High-resolution tandem mass spectrometry (HRMS) was carried out to identify the ozonolysis products (TG48:0-monoozonide) formed under exposure to the highly reactive ozone in atmospheric air. The obtained products were confirmed by matrix assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI). Despite several challenges and limitations in the age estimation of fingerprints, the identification of individual degradation products of specific unsaturated lipids in aged fingerprint samples represents a significant analytical progress, resulting in a strong increase in the validity of chemical analysis of fingerprints.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c7an01506bDOI Listing
February 2018

Same, same but different!-matching entomological traces to a human food source by stable isotope analysis.

Int J Legal Med 2018 May 30;132(3):915-921. Epub 2017 Nov 30.

Institute of Legal Medicine, University Hospital Frankfurt, Goethe-University, Frankfurt am Main, Germany.

Blow flies are important tools in forensic entomology, as they feed and develop on human bodies. This fact can be used to estimate the minimum post mortem interval (PMI), by classifying the age of the immature stages found on corpses. The capacity to also be able to classify the age of adult flies, or even empty puparia, could increase the timeframe for a PMI. However, the association of older developmental stages, such as adult flies or their empty cases, with a human cadaver may be challenged, as such specimens could stem from another food source. Analyzing the stable carbon (δC) and nitrogen (δN) isotopes in such specimens could be helpful here, as the isotope signatures reflect those of the food sources. We compared the δN and δC signatures of tissue from humans and 12 additional species by elemental analyzer-isotope ratio mass spectrometry (EA-IRMS). We did the same for adult flies and empty puparia of the blow fly Lucilia sericata, which were derived from juvenile stages developed on tissues from the mentioned species. The isotope signatures for the adult flies and their empty puparia linearly mirrored the isotope signatures for the respective tissues on which they developed as larvae. Results such as these are useful to indicate the flies' nutritional history, but they do not provide the same kind of evidence that a DNA analysis would. As individual dietary habits, global distribution and environmental effects can influence isotope ratios, we strongly recommend to analyzing entomological traces and muscle tissues of potential donors or for other food sources.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00414-017-1753-9DOI Listing
May 2018

Catalysis of a 1,3-dipolar reaction by distorted DNA incorporating a heterobimetallic platinum(ii) and copper(ii) complex.

Chem Sci 2017 Oct 22;8(10):7038-7046. Epub 2017 Aug 22.

Department of Organic Chemistry I , Centro de Innovación en Química Avanzada (ORFEO-CINQA) , Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU) , Donostia International Physics Center (DIPC) , Po Manuel Lardizabal 3 , E-20018 Donostia/San Sebastián , Spain . Email:

A novel catalytic system based on covalently modified DNA is described. This catalyst promotes 1,3-dipolar reactions between azomethine ylides and maleimides. The catalytic system is based on the distortion of the double helix of DNA by means of the formation of Pt(ii) adducts with guanine units. This distortion, similar to that generated in the interaction of DNA with platinum chemotherapeutic drugs, generates active sites that can accommodate -metallated azomethine ylides. The proposed reaction mechanism, based on QM(DFT)/MM calculations, is compatible with thermally allowed concerted (but asynchronous) [π4s + π2s] mechanisms leading to the exclusive formation of racemic -cycloadducts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c7sc02311aDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5637124PMC
October 2017

Determination of the Density and Temperature Dependence of the Shear Viscosity of a Unitary Fermi Gas Based on Hydrodynamic Flow.

Phys Rev Lett 2017 Aug 10;119(6):065302. Epub 2017 Aug 10.

Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA.

We determine the shear viscosity of the ultracold Fermi gas at unitarity in the normal phase using hydrodynamic expansion data. The analysis is based on a generalized fluid dynamic framework which ensures a smooth transition between the fluid dynamic core of the cloud and the ballistic corona. We use expansion data taken by Joseph, Elliott, and Thomas [Shear Viscosity of a Universal Fermi Gas Near the Superfluid Phase Transition, Phys. Rev. Lett. 115, 020401 (2015).PRLTAO0031-900710.1103/PhysRevLett.115.020401] and measurements of the equation of state by Ku et al. [Revealing the superfluid lambda transition in the universal thermodynamics of a unitary Fermi gas, Science 335, 563 (2012).SCIEAS0036-807510.1126/science.1214987]. We find that the shear viscosity to particle density ratio just above the critical temperature is η/n|_{T_{c}}=0.41±0.11. We also obtain evidence that the shear viscosity to entropy density ratio has a minimum slightly above T_{c} with η/s|_{min}=0.50±0.10.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1103/PhysRevLett.119.065302DOI Listing
August 2017

[Listening to music in old age : Investigation of utilization and psychosocial resources].

Z Gerontol Geriatr 2018 Aug 18;51(6):682-690. Epub 2017 Apr 18.

Institut für Psychologie, TU Chemnitz, 09107, Chemnitz, Deutschland.

Background: Studies with younger participants have shown that listening to music is used to achieve a multitude of positive effects that can be summarized by three fundamental dimensions: self-awareness, social relatedness and regulation of mood and arousal. For the elderly, these effects contain a high potential with respect to alleviation of affective symptoms and enhancement of social participation; however, it is still unclear if the elderly exhibit the same pattern of fundamental uses of listening to music as younger persons and how they evaluate their access to music in different housing situations.

Material And Methods: To answer these questions, 115 persons (aged 57-94 years) in different housing situations were asked for their motives for listening to music and their satisfaction with various aspects of access to music.

Results: The elderly showed the same pattern of the three fundamental dimensions of the use of listening to music as younger respondents, although specific uses were more pronounced, such as relaxation, reminiscing, and compensation for loneliness; however, the general intensity of the use of listening to music was lower. Older people saw deficits in the frequency, coordination, and communication of musical arrangements in their residential environment.

Conclusion: Older people listen to music to obtain specific effects in the same way as younger people do; however, the decreasing intensity of the use of listening to music, together with the desires of the older respondents, demonstrate a need for more musical arrangements that should be better coordinated, communicated, and preferably personalized.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00391-017-1229-zDOI Listing
August 2018

Chiral Lagrangian from Duality and Monopole Operators in Compactified QCD.

Phys Rev Lett 2016 Aug 15;117(8):081601. Epub 2016 Aug 15.

Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA.

We show that there exists a special compactification of QCD on R^{3}×S^{1} in which the theory has a domain where continuous chiral symmetry breaking is analytically calculable. We give a microscopic derivation of the chiral Lagrangian, the chiral condensate, and the Gell-Mann-Oakes-Renner relation m_{π}^{2}f_{π}^{2}=-m_{q}⟨q[over ¯]q⟩. Abelian duality, monopole operators, and flavor-twisted boundary conditions play the main roles. The flavor twisting leads to the new effect of fractional jumping of fermion zero modes among monopole instantons. Chiral symmetry breaking is induced by monopole-instanton operators, and the Nambu-Goldstone pions arise by color-flavor transmutation from gapless "dual photons." We also give a microscopic picture of the "constituent quark" masses. Our results are consistent with expectations from chiral perturbation theory at large S^{1}, and yield strong support for adiabatic continuity between the small-S^{1} and large-S^{1} regimes. We also find concrete microscopic connections between N=1 and N=2 supersymmetric gauge theory dynamics and nonsupersymmetric QCD dynamics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1103/PhysRevLett.117.081601DOI Listing
August 2016

Unprecedented Efficient Structure Controlled Phosphorescence of Silver(I) Clusters Stabilized by Carba-closo-dodecaboranylethynyl Ligands.

Angew Chem Int Ed Engl 2016 08 19;55(35):10507-11. Epub 2016 Jul 19.

Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.

{Ag2 (12-C≡C-closo-1-CB11 H11 )}n and selected pyridine ligands have been used for the synthesis of photostable Ag(I) clusters that, with one exception, exhibit for Ag(I) compounds unusual room-temperature phosphorescence. Extraordinarily intense phosphorescence was observed for a distorted pentagonal bipyramidal Ag(I) 7 cluster that shows an unprecedented quantum yield of Φ=0.76 for Ag(I) clusters. The luminescence properties correlate with the structures of the central Ag(I) n motifs as shown by comparison of the emission properties of the clusters with different numbers of Ag(I) ions, different charges, and electronically different pyridine ligands.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/anie.201604198DOI Listing
August 2016

Fatty Acid Structure and Degradation Analysis in Fingerprint Residues.

J Am Soc Mass Spectrom 2016 09 20;27(9):1565-74. Epub 2016 Jun 20.

Federal Criminal Police Office, Forensic Science Institute, KT12, 65173, Wiesbaden, Germany.

GC-MS investigations were carried out to elucidate the aging behavior of unsaturated fatty acids in fingerprint residues and to identify their degradation products in aged samples. For this purpose, a new sample preparation technique for fingerprint residues was developed that allows producing N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA) derivatives of the analyzed unsaturated fatty acids and their degradation products. MSTFA derivatization catalyzed by iodotrimethylsilane enables the reliable identification of aldehydes and oxoacids as characteristic MSTFA derivatives in GCMS. The obtained results elucidate the degradation pathway of unsaturated fatty acids. Our study of aged fingerprint residues reveals that decanal is the main degradation product of the observed unsaturated fatty acids. Furthermore, oxoacids with different chain lengths are detected as specific degradation products of the unsaturated fatty acids. The detection of the degradation products and their chain length is a simple and effective method to determine the double bond position in unsaturated compounds. We can show that the hexadecenoic and octadecenoic acids found in fingerprint residues are not the pervasive fatty acids Δ9-hexadecenoic (palmitoleic acid) and Δ9-octadecenoic (oleic acid) acid but Δ6-hexadecenoic acid (sapienic acid) and Δ8-octadecenoic acid. The present study focuses on the structure identification of human sebum-specific unsaturated fatty acids in fingerprint residues based on the identification of their degradation products. These results are discussed for further investigations and method developments for age determination of fingerprints, which is still a tremendous challenge because of several factors affecting the aging behavior of individual compounds in fingerprints. Graphical Abstract ᅟ.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s13361-016-1429-6DOI Listing
September 2016

Small molecule detection by lateral flow strips via aptamer-gated silica nanoprobes.

Analyst 2016 Apr 4;141(8):2595-9. Epub 2016 Apr 4.

School of Medicine, Istanbul Kemerburgaz University, Istanbul, 34217, Turkey.

A fast, sensitive and ratiometric biosensor strategy for small molecule detection was developed through nanopore actuation. The new platform engineers together, a highly selective molecular recognition element, aptamers, and a novel signal amplification mechanism, gated nanopores. As a proof of concept, aptamer gated silica nanoparticles have been successfully used as a sensing platform for the detection of ATP concentrations at a wide linear range from 100 μM up to 2 mM.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c6an00273kDOI Listing
April 2016

The Goals and Effects of Music Listening and Their Relationship to the Strength of Music Preference.

Authors:
Thomas Schäfer

PLoS One 2016 17;11(3):e0151634. Epub 2016 Mar 17.

Department of Psychology, Chemnitz University of Technology, Chemnitz, Germany.

Individual differences in the strength of music preference are among the most intricate psychological phenomena. While one person gets by very well without music, another person needs to listen to music every day and spends a lot of temporal and financial resources on listening to music, attending concerts, or buying concert tickets. Where do these differences come from? The hypothesis presented in this article is that the strength of music preference is mainly informed by the functions that music fulfills in people's lives (e.g., to regulate emotions, moods, or physiological arousal; to promote self-awareness; to foster social relatedness). Data were collected with a diary study, in which 121 respondents documented the goals they tried to attain and the effects that actually occurred for up to 5 music-listening episodes per day for 10 successive days. As expected, listeners reporting more intense experience of the functional use of music in the past (1) had a stronger intention to listen to music to attain specific goals in specific situations and (2) showed a larger overall strength of music preference. It is concluded that the functional effectiveness of music listening should be incorporated in existing models and frameworks of music preference to produce better predictions of interindividual differences in the strength of music preference. The predictability of musical style/genre preferences is also discussed with regard to the present results.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0151634PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4795651PMC
July 2016

Complexified Path Integrals, Exact Saddles, and Supersymmetry.

Phys Rev Lett 2016 Jan 6;116(1):011601. Epub 2016 Jan 6.

Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA.

In the context of two illustrative examples from supersymmetric quantum mechanics we show that the semiclassical analysis of the path integral requires complexification of the configuration space and action, and the inclusion of complex saddle points, even when the parameters in the action are real. We find new exact complex saddles, and show that without their contribution the semiclassical expansion is in conflict with basic properties such as the positive semidefiniteness of the spectrum, as well as constraints of supersymmetry. Generic saddles are not only complex, but also possibly multivalued and even singular. This is in contrast to instanton solutions, which are real, smooth, and single valued. The multivaluedness of the action can be interpreted as a hidden topological angle, quantized in units of π in supersymmetric theories. The general ideas also apply to nonsupersymmetric theories.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1103/PhysRevLett.116.011601DOI Listing
January 2016

Blu-ray based optomagnetic aptasensor for detection of small molecules.

Biosens Bioelectron 2016 Jan 29;75:396-403. Epub 2015 Aug 29.

Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby, Denmark. Electronic address:

This paper describes an aptamer-based optomagnetic biosensor for detection of a small molecule based on target binding-induced inhibition of magnetic nanoparticle (MNP) clustering. For the detection of a target small molecule, two mutually exclusive binding reactions (aptamer-target binding and aptamer-DNA linker hybridization) are designed. An aptamer specific to the target and a DNA linker complementary to a part of the aptamer sequence are immobilized onto separate MNPs. Hybridization of the DNA linker and the aptamer induces formation of MNP clusters. The target-to-aptamer binding on MNPs prior to the addition of linker-functionalized MNPs significantly hinders the hybridization reaction, thus reducing the degree of MNP clustering. The clustering state, which is thus related to the target concentration, is then quantitatively determined by an optomagnetic readout technique that provides the hydrodynamic size distribution of MNPs and their clusters. A commercial Blu-ray optical pickup unit is used for optical signal acquisition, which enables the establishment of a low-cost and miniaturized biosensing platform. Experimental results show that the degree of MNP clustering correlates well with the concentration of a target small molecule, adenosine triphosphate (ATP) in this work, in the range between 10µM and 10mM. This successful proof-of-concept indicates that our optomagnetic aptasensor can be further developed as a low-cost biosensing platform for detection of small molecule biomarkers in an out-of-lab setting.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bios.2015.08.062DOI Listing
January 2016

The sounds of safety: stress and danger in music perception.

Front Psychol 2015 5;6:1140. Epub 2015 Aug 5.

Department of Psychology, Chemnitz University of Technology , Chemnitz, Germany.

As with any sensory input, music might be expected to incorporate the processing of information about the safety of the environment. Little research has been done on how such processing has evolved and how different kinds of sounds may affect the experience of certain environments. In this article, we investigate if music, as a form of auditory information, can trigger the experience of safety. We hypothesized that (1) there should be an optimal, subjectively preferred degree of information density of musical sounds, at which safety-related information can be processed optimally; (2) any deviation from the optimum, that is, both higher and lower levels of information density, should elicit experiences of higher stress and danger; and (3) in general, sonic scenarios with music should reduce experiences of stress and danger more than other scenarios. In Experiment 1, the information density of short music-like rhythmic stimuli was manipulated via their tempo. In an initial session, listeners adjusted the tempo of the stimuli to what they deemed an appropriate tempo. In an ensuing session, the same listeners judged their experienced stress and danger in response to the same stimuli, as well as stimuli exhibiting tempo variants. Results are consistent with the existence of an optimum information density for a given rhythm; the preferred tempo decreased for increasingly complex rhythms. The hypothesis that any deviation from the optimum would lead to experiences of higher stress and danger was only partly fit by the data. In Experiment 2, listeners should indicate their experience of stress and danger in response to different sonic scenarios: music, natural sounds, and silence. As expected, the music scenarios were associated with lowest stress and danger whereas both natural sounds and silence resulted in higher stress and danger. Overall, the results largely fit the hypothesis that music seemingly carries safety-related information about the environment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2015.01140DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4524892PMC
August 2015

Hidden Topological Angles in Path Integrals.

Phys Rev Lett 2015 Jul 24;115(4):041601. Epub 2015 Jul 24.

Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA.

We demonstrate the existence of hidden topological angles (HTAs) in a large class of quantum field theories and quantum mechanical systems. HTAs are distinct from theta parameters in the Lagrangian. They arise as invariant angles associated with saddle points of the complexified path integral and their descent manifolds (Lefschetz thimbles). Physical effects of HTAs become most transparent upon analytic continuation in n_{f} to a noninteger number of flavors, reducing in the integer n_{f} limit to a Z_{2} valued phase difference between dominant saddles. In N=1 super Yang-Mills theory we demonstrate the microscopic mechanism for the vanishing of the gluon condensate. The same effect leads to an anomalously small condensate in a QCD-like SU(N) gauge theory with fermions in the two-index representation. The basic phenomenon is that, contrary to folklore, the gluon condensate can receive both positive and negative contributions in a semiclassical expansion. In quantum mechanics, a HTA leads to a difference in semiclassical expansion of integer and half-integer spin particles.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1103/PhysRevLett.115.041601DOI Listing
July 2015