98 results on '"Penz, M."'
Search Results
2. Mitomycin C in combination with capecitabine or biweeklyhigh-dose gemcitabine in patients with advanced biliary tract cancer: a randomised phase II trial
- Author
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Kornek, G.V., Schuell, B., Laengle, F., Gruenberger, T., Penz, M., Karall, K., Depisch, D., Lang, F., and Scheithauer, W.
- Published
- 2004
- Full Text
- View/download PDF
3. Mitomycin C in combination with capecitabine or biweekly high-dose gemcitabine in patients with advanced biliary tract cancer: a randomised phase II trial
- Author
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Kornek, G. V., Schuell, B., Laengle, F., Gruenberger, T., Penz, M., Karall, K., Depisch, D., Lang, F., and Scheithauer, W.
- Published
- 2004
4. Impaired response of gastric MALT-lymphoma to Helicobacter pylori eradication in patients with autoimmune disease
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Raderer, M., Österreicher, C., Machold, K., Formanek, M., Fiebiger, W., Penz, M., Dragosics, B., and Chott, A.
- Published
- 2001
5. Second-line treatment with oxaliplatin + raltitrexed in patients with advanced colorectal cancer failing fluoropyrimidine/leucovorin-based chemotherapy
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Scheithauer, W., Kornek, G. V., Schuell, B., Ulrich-Pur, H., Penz, M., Raderer, M., Lang, F., Schneeweiss, B., Lenauer, A., and Depisch, D.
- Published
- 2001
6. Subcutaneous administration of amifostine: A promising therapeutic option in patients with oxaliplatin-related peripheral sensitive neuropathy
- Author
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Penz, M., Kornek, G. V., Raderer, M., Ulrich-Pur, H., Fiebiger, W., and Scheithauer, W.
- Published
- 2001
7. Phase II trial of two-weekly gemcitabine in patients with advanced biliary tract cancer
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Penz, M., Kornek, G. V., Raderer, M., Ulrich-Pur, H., Fiebiger, W., Lenauer, A., Depisch, D., Krauss, G., Schneeweiss, B., and Scheithauer, W.
- Published
- 2001
8. PROMISING THERAPEUTIC POTENTIAL OF OXALIPLATIN + RALTITREXED IN PATIENTS WITH ADVANCED COLORECTAL CANCER (ACC): RESULTS OF A PHASE I/II TRIAL: Abstract 997
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Scheithauer, W., Kornek, G. V., Ulrich-Pur, H., Raderer, M., Penz, M., Haider, K., Kwasny, W., Lang, F., and Depisch, D.
- Published
- 2000
9. Depressive symptoms are not associated with long-term integrated testosterone concentrations in hair.
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Walther, A., Wehrli, S., Kische, H., Penz, M., Wekenborg, M., Gao, W., Rothe, N., Beesdo-Baum, K., and Kirschbaum, C.
- Subjects
TESTOSTERONE ,MENTAL depression ,SALIVA ,PANEL analysis ,HAIR - Abstract
The association between depressive symptomatology and endogenous testosterone levels is inconclusive. Large inter- and intra-individual testosterone differences suggest point measurements from saliva or serum to be inadequate to map basal testosterone concentrations highlighting the potential for long-term integrated testosterone levels from hair. Using data from a prospective cohort study, a total of 578 participants (74% female) provided complete data on depressive symptomatology, clinical features, and hair samples for quantification of testosterone concentrations at baseline. Available data of three annual follow-up examinations were used for longitudinal analyses. Correlation analysis showed in both, men and women, hair testosterone across all the four time points not to be significantly related to depressive symptoms. Examined clinical features were not associated with testosterone levels, except for having a current diagnosis of a psychological disorder, which was associated with reduced testosterone levels in men, but not in women. Acceptable model fit for an autoregressive cross-lagged panel analysis emerged only for the female subsample suggesting inverse cross-relations for the prediction of testosterone by depressive symptomatology and vice versa. Findings from this study add to the literature by showing no association between long-term integrated testosterone in hair and depressive symptomatology in men and women. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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10. Qualit�tssicherung in der Geriatrie - Chancen und Risiken der aktuellen Gesundheitsreform (GKV-Wettbewerbsst�rkungsgesetz).
- Author
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Sieber, C., Tr�gner, J., Penz, M., and Gerber, H.
- Published
- 2008
- Full Text
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11. Improved method for testing the influence of immunmodulators on the cytotoxic activity of natural killer cells.
- Author
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Penz M, Müller A, Hofstetter S, and Bieger WP
- Published
- 2002
12. Somatostatin-receptor scintigraphy for staging and follow-up of patients with extraintestinal marginal zone B-cell lymphoma of the mucosa associated lymphoid tissue (MALT)-type.
- Author
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Raderer, M, Traub, T, Formanek, M, Virgolini, I, Österreicher, C, Fiebiger, W, Penz, M, Jäger, U, Pont, J, Chott, A, and Kurtaran, A
- Subjects
SOMATOSTATIN ,LYMPHOMAS - Abstract
The majority of lymphomas of the mucosa-associated lymphoid tissue (MALT)-type arise in the stomach, but extragastric locations are also frequently encountered. Due to previous results indicating that somatostatin receptor (SSTR)-expression distinguishes between gastric and extragastric MALT-type lymphoma, we have initiated a study to evaluate the role of SSTR-scintigraphy for staging and follow-up of patients with extragastric manifestations of MALT-type lymphoma. A total of 30 consecutive patients, including 24 with primary extragastric MALT-type lymphoma, 5 patients with dissemination to extragastric sites (including colon, lung, parotid, ocular adnexa and breast) following an initial gastric MALT-lymphoma and one patient with spread to stomach, lung and lymph nodes following parotid lymphoma were prospectively studied. All patients had histologically verified MALT-type lymphoma: 2 patients had lymphoma presenting in the lung, 9 in the ocular adnexa, 7 had lymphomas in the parotid, 2 patients had disease located in the breast, 3 patients had lymph-node relapse following MALT-type lymphoma of the parotid, the lacrimal gland and the thyroid, and 1 had primary MALT-lymphoma of the liver. All patients underwent SSTR-scintigraphy using [SUP111]In-DTPA-D-Phe[SUP1]-Octreotide ([SUP111]In-OCT) before initiation of therapy, while 13 also had a second scan after treatment. The results of gamma camera imaging were compared to conventional staging. No positive scans could be obtained in patients with dissemination following gastric lymphoma, while all patients with primary extragastric lymphoma had positive scans at the site of histologically documented involvement before initiation of therapy. In addition, also the patient with secondary spread to stomach, lung and lymph nodes was positive in all documented lymphoma sites. In one patient, focal tracer uptake in projection to the maxillary sinus was documented, which was bioptically verified as inflammation. In the... [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
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13. Oxaliplatin plus raltitrexed in patients with advanced colorectal carcinoma: results of a Phase I-II trial.
- Author
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Scheithauer, Werner, Kornek, Gabriela V., Ulrich-Pur, Herbert, Penz, Melitta, Raderer, Markus, Salek, Tomas, Haider, Karin, Kwasny, Werner, Depisch, Dieter, Scheithauer, W, Kornek, G V, Ulrich-Pur, H, Penz, M, Raderer, M, Salek, T, Haider, K, Kwasny, W, and Depisch, D
- Published
- 2001
- Full Text
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14. Importance of extensive staging in patients with mucosa-associated lymphoid tissue (MALT)-type lymphoma.
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Raderer, M, Vorbeck, F, Formanek, M, Österreicher, C, Valencak, J, Penz, M, Kornek, G, Hamilton, G, Dragosics, B, and Chott, A
- Subjects
LYMPHOMAS ,LYMPHOID tissue - Abstract
Lymphoma of the mucosa-associated lymphoid tissue (MALT) type usually arises in MALT acquired through chronic antigenic stimulation triggered by persistent infection and/or autoimmune processes. Due to specific ligand-receptor interactions between lymphoid cells and high-endothelial venules of MALT, both normal and neoplastic lymphoid cells display a pronounced homing tendency to MALT throughout the body. In the case of neoplastic disease these homing properties may be responsible for lymphoma dissemination among various MALT-sites. According to this concept, we have standardized staging procedures in all patients diagnosed with MALT-type lymphoma. All patients with MALT-type lymphoma underwent standardized staging procedures before treatment. Staging included ophthalmologic examination, otolaryngologic investigation, gastroscopy with multiple biopsies, endosonography of the upper gastrointestinal tract, enteroclysis, colonoscopy, computed tomography of thorax and abdomen and bone marrow biopsy. Biopsy was performed in all lesions suggestive for lymphomatous involvement, and evaluation of all biopsy specimens was performed by a reference pathologist. 35 consecutive patients with histologically verified MALT-type lymphoma were admitted to our department. Twenty-four patients (68%) had primary involvement of the stomach, five (15%) had lymphoma of the ocular adnexa, three (8.5%) had lymphoma of the parotid, and three (8,5%) of the lung. Lymph-node involvement corresponding to stage EII disease was found in 13 patients (37%), only one patient with primary gastric lymphoma had local and supradiaphragmatic lymph-node involvement (stage EIII). Bone marrow biopsies were negative in all patients. Overall, eight of 35 patients (23%) had simultaneous biopsy-proven involvement of two MALT-sites: one patient each had lymphoma of parotid and lacrimal gland, conjunctiva and hypopharynx, conjunctiva and skin, lacrimal gland and lung, stomach and colon, and stomach and lung.... [ABSTRACT FROM AUTHOR]
- Published
- 2000
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15. Malignancy in Slow Motion: Diagnosis of Biochemically Apparent, but Otherwise Occult Persistent Disease 21 Years After Resection of a Carcinoid Tumour of the Terminal Ileum.
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Fiebiger, W., Penz, M., Längle, F., Kurtaran, A., Oberhuber, G., and Raderer, M.
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- *
SOMATOSTATIN , *ILEUM diseases , *PHYSIOLOGY - Abstract
Carcinoid tumors may relapse after a long time span following initial diagnosis, and relapse might be clinically inapparent despite biochemical indications due to a low sensitivity of conventional methods. We present the case of a patient who had biochemical indication for hidden disease persistence for more than two decades. In 1978, a 39-year-old man underwent surgery for a carcinoid tumour of the ileum measuring 3.5 cm with multiple local lymph-node metastases. After surgery, however, serotonin- and urinary 5-hydroxy-indole-acetic-acid (5-HIAA) remained markedly elevated, and persisted over more than 20 years at levels between 600 and 950 ng/ml for serum serotonin (normal range 40-400 ng/ml) and 29-35 mg/24 h for 5-HIAA (normal range 2-9 mg/24 h). Despite this, regular radiological follow-up, including sonography and CT-scan, did not reveal the location of suspected malignancy until 1999, when the patient was re-admitted to our hospital for a hypertensive episode. CT-scanning of the abdomen showed a singular lesion within the liver, which was verified as recurrence of the carcinoid by fine needle biopsy. Somatostatin receptor scintigraphy using [sup 111]In-DTPA-D-Phe[sup 1]-Octreotide revealed a second lesion within the liver along with local recurrence at the anastomosis, which was verified by surgery. While the propensity for late relapse of ileal carcinoids has repeatedly been demonstrated, a case with biochemical signs of disease persistence over a time span of 21 years before final diagnosis is unusual. In addition, our case reflects the low sensitivity of conventional radiological evaluation for localization of carcinoid tumours as compared to somatostatin receptor scanning. [ABSTRACT FROM AUTHOR]
- Published
- 2001
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16. Routine serum laboratory parameters for the staging of fibrosis in patients with chronic hepatitis C
- Author
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Penz, M., Oesterreicher, C., Wrba, F., Datz, C., Gschwandtler, M., Hofer, H., Novacek, G., Gangl, A., and Ferenci, P.
- Published
- 2003
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17. Interferon (IFN)-alpha receptor promotor polymorphisms and IFN-sensitivity in HCV-genotype 1 infection
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Oesterreicher, C., Hofer, H., Willheim-Polli, C., Jessner, W., Penz, M., and Ferenci, P.
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- 2003
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18. General Runge-Gross-type theorem for dipole laser-matter interaction
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Penz, M [Institut fuer Theoretische Physik, Universitaet Innsbruck, 6020 Innsbruck (Austria)]
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- 2010
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19. Geometrical perspective on spin-lattice density-functional theory.
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Penz M and van Leeuwen R
- Abstract
A recently developed viewpoint on the fundamentals of density-functional theory for finite interacting spin-lattice systems that centers around the notion of degeneracy regions is presented. It allows for an entirely geometrical description of the Hohenberg-Kohn theorem and v-representability. The phenomena receive exemplification by an Anderson impurity model and other small-lattice examples. The case of adiabatic change and the time-dependent setting are examined as well., (© 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).)
- Published
- 2024
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20. Information as a resource: Can perceived information process quality in the workplace contribute to more optimism in times of crisis?
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Stiglbauer B and Penz M
- Subjects
- Humans, Male, Female, Adult, Prospective Studies, Middle Aged, SARS-CoV-2, Optimism psychology, COVID-19 psychology, Workplace psychology
- Abstract
Against the background of Job Demands-Resources and Conservation of Resources theory and research on organizational communication, this prospective study among n = 312 employees explores the significant role of perceived information process quality (PIPQ) in enhancing employees' optimism during the COVID-19 pandemic. It thereby contributes to a deeper understanding of the factors influencing employee optimism in challenging contexts. In this study, PIPQ is defined by the availability of timely information, clarity, and consistency in the information provided. Results from latent change score modelling revealed that employees who experienced high PIPQ, particularly consistent information, reported feeling more optimistic about work-related aspects and also experienced spillover effects into their private lives. Notably, both consistency in information prior to the pandemic and increases in consistent information during the pandemic demonstrated this beneficial effect. Moreover, timely available information also positively influenced optimism, especially regarding work-related aspects. However, the study did not find evidence that clarity in information significantly affected optimism. In summary, the findings underscore the importance of accessible and consistent information as a vital resource for employees' ability to navigate crises., (© 2024 John Wiley & Sons Ltd.)
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- 2024
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21. Longitudinal associations between depressive symptoms and cell deformability: do glucocorticoids play a role?
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Eder J, Kräter M, Kirschbaum C, Gao W, Wekenborg M, Penz M, Rothe N, Guck J, Wittwer LD, and Walther A
- Abstract
Cell deformability of all major blood cell types is increased in depressive disorders (DD). Furthermore, impaired glucocorticoid secretion is associated with DD, as well as depressive symptoms in general and known to alter cell mechanical properties. Nevertheless, there are no longitudinal studies examining accumulated glucocorticoid output and depressive symptoms regarding cell deformability. The aim of the present study was to investigate, whether depressive symptoms predict cell deformability one year later and whether accumulated hair glucocorticoids mediate this relationship. In 136 individuals (n
female = 100; Mage = 46.72, SD = 11.28; age range = 20-65), depressive symptoms (PHQ-9) and hair glucocorticoids (cortisol and cortisone) were measured at time point one (T1), while one year later (T2) both depressive symptoms and hair glucocorticoids were reassessed. Additionally, cell deformability of peripheral blood cells was assessed at T2. Depression severity at T1 predicted higher cell deformability in monocytes and lymphocytes at T2. Accumulated hair cortisol and cortisone concentrations from T1 and T2 were not associated with higher cell deformability and further did not mediate the relationship between depressive symptoms and cell deformability. Elevated depressive symptomatology in a population based sample is longitudinally associated with higher immune cell deformability, while long-term integrated glucocorticoid levels seem not to be implicated in the underlying mechanism., (© 2024. The Author(s).)- Published
- 2024
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22. Evaluation of the point sampling method and inter-comparison of remote emission sensing systems for screening real-world car emissions.
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Knoll M, Penz M, Schmidt C, Pöhler D, Rossi T, Casadei S, Bernard Y, Hallquist ǺM, Sjödin Ǻ, and Bergmann A
- Abstract
Emissions from internal combustion vehicles are currently not properly monitored throughout their life cycle. Remote emission sensing (RES) is a technology that can measure emissions under real driving conditions without contact. Current light extinction based RES systems are capable of providing emission factors for various gases, but lack accuracy for particulate matter (PM). Point Sampling (PS) is an extraction-based RES technique that can measure gases as well as various particle metrics such as black carbon or particle number. In this work, we evaluated the performance of a recently developed PS system and the state-of-the-art light extinction based remote sensing devices EDAR (HEAT) and ORSD (OPUS RSE) during co-location measurements. Validation measurements with portable emission measurement systems and emissions screening of several thousand cars in three European cities provide detailed insights into system's performance. Meteorological evaluations showed that the PS capture rate is strongly influenced by wind, but no other weather influences were found. Both light extinction based systems are unable to measure during rain. We found that all three systems tested were capable of screening NO
x emissions from pre-Euro 6 diesel cars. Measurement results show the ability of the PS system to quantify high and low PM emitters equally well. The open-path RES systems (EDAR, ORSD) are capable of estimating PM emissions from pre-Euro 5 diesel cars. However, deficiencies of open-path RES systems are evident in the quantification of PM emissions from newer engine technologies (diesel Euro 5 and beyond) and from petrol cars. The PS system has a 2 to 5 times lower capture rate than open-path RES systems, but the PS measurement results are more accurate (more than 5 times for PM and more than 1.35 times for NOx ). The good accuracy of individual measurements makes PS a powerful tool for reliable high emitter identification., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2024
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23. Exchange-only virial relation from the adiabatic connection.
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Laestadius A, Csirik MA, Penz M, Tancogne-Dejean N, Ruggenthaler M, Rubio A, and Helgaker T
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The exchange-only virial relation due to Levy and Perdew is revisited. Invoking the adiabatic connection, we introduce the exchange energy in terms of the right-derivative of the universal density functional w.r.t. the coupling strength λ at λ = 0. This agrees with the Levy-Perdew definition of the exchange energy as a high-density limit of the full exchange-correlation energy. By relying on v-representability for a fixed density at varying coupling strength, we prove an exchange-only virial relation without an explicit local-exchange potential. Instead, the relation is in terms of a limit (λ ↘ 0) involving the exchange-correlation potential vxcλ, which exists by assumption of v-representability. On the other hand, a local-exchange potential vx is not warranted to exist as such a limit., (© 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).)
- Published
- 2024
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24. Exchange energies with forces in density-functional theory.
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Tancogne-Dejean N, Penz M, Laestadius A, Csirik MA, Ruggenthaler M, and Rubio A
- Abstract
We propose exchanging the energy functionals in ground-state density-functional theory with physically equivalent exact force expressions as a new promising route toward approximations to the exchange-correlation potential and energy. In analogy to the usual energy-based procedure, we split the force difference between the interacting and auxiliary Kohn-Sham system into a Hartree, an exchange, and a correlation force. The corresponding scalar potential is obtained by solving a Poisson equation, while an additional transverse part of the force yields a vector potential. These vector potentials obey an exact constraint between the exchange and correlation contribution and can further be related to the atomic shell structure. Numerically, the force-based local-exchange potential and the corresponding exchange energy compare well with the numerically more involved optimized effective potential method. Overall, the force-based method has several benefits when compared to the usual energy-based approach and opens a route toward numerically inexpensive nonlocal and (in the time-dependent case) nonadiabatic approximations., (© 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).)
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- 2024
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25. Weakened Topological Protection of the Quantum Hall Effect in a Cavity.
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Rokaj V, Wang J, Sous J, Penz M, Ruggenthaler M, and Rubio A
- Abstract
We study the quantum Hall effect in a two-dimensional homogeneous electron gas coupled to a quantum cavity field. As initially pointed out by Kohn, Galilean invariance for a homogeneous quantum Hall system implies that the electronic center of mass (c.m.) decouples from the electron-electron interaction, and the energy of the c.m. mode, also known as Kohn mode, is equal to the single particle cyclotron transition. In this work, we point out that strong light-matter hybridization between the Kohn mode and the cavity photons gives rise to collective hybrid modes between the Landau levels and the photons. We provide the exact solution for the collective Landau polaritons and we demonstrate the weakening of topological protection at zero temperature due to the existence of the lower polariton mode which is softer than the Kohn mode. This provides an intrinsic mechanism for the recently observed topological breakdown of the quantum Hall effect in a cavity [F. Appugliese et al., Breakdown of topological protection by cavity vacuum fields in the integer quantum Hall effect, Science 375, 1030 (2022).SCIEAS0036-807510.1126/science.abl5818]. Importantly, our theory predicts the cavity suppression of the thermal activation gap in the quantum Hall transport. Our work paves the way for future developments in cavity control of quantum materials.
- Published
- 2023
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26. Exhaustion and cardiovascular risk factors: the role of vagally-mediated heart rate variability.
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Wekenborg MK, Künzel RG, Rothe N, Penz M, Walther A, Kirschbaum C, Thayer JF, and Hill LK
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- Middle Aged, Female, Humans, Aged, Adult, Male, Heart Rate physiology, Risk Factors, Cardiovascular Diseases epidemiology
- Abstract
Purpose: Exhaustion symptoms are known to be associated with cardiovascular disease (CVD) risk; however, the underlying mechanisms remain unclear. Autonomic imbalance, as indicated by reductions in vagally-mediated heart rate variability (vmHRV), appears to be a valid candidate for such a biological link, as it has been associated with both exhaustion symptoms and CVD risk and mortality., Methods: The present study examined a potential mediation of vmHRV on the association between exhaustion symptoms and self-reported CVD risk factors as well as the age dependency of this mediation in a large, heterogeneous sample of the Dresden Burnout Study (N = 388; 72.9% females; M
age = 42.61, SD = 11.67)., Results: Results indicate that exhaustion symptoms were indirectly associated with CVD risk factors through vmHRV even after adjusting for well-known confounders (i.e., sex, body mass index, depressive symptoms). Moreover, this pattern was significant only among middle-aged (i.e., 54.27 years) and older individuals., Conclusions: Our findings add to growing evidence that autonomic imbalance may be a key biological link between exhaustion symptoms and CVD risk in middle-aged and older individuals. Implications for public health are discussed., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)- Published
- 2023
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27. The Structure of the Density-Potential Mapping. Part II: Including Magnetic Fields.
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Penz M, Tellgren EI, Csirik MA, Ruggenthaler M, and Laestadius A
- Abstract
The Hohenberg-Kohn theorem of density-functional theory (DFT) is broadly considered the conceptual basis for a full characterization of an electronic system in its ground state by just one-body particle density. In this Part II of a series of two articles, we aim at clarifying the status of this theorem within different extensions of DFT including magnetic fields. We will in particular discuss current-density-functional theory (CDFT) and review the different formulations known in the literature, including the conventional paramagnetic CDFT and some nonstandard alternatives. For the former, it is known that the Hohenberg-Kohn theorem is no longer valid due to counterexamples. Nonetheless, paramagnetic CDFT has the mathematical framework closest to standard DFT and, just like in standard DFT, nondifferentiability of the density functional can be mitigated through Moreau-Yosida regularization. Interesting insights can be drawn from both Maxwell-Schrödinger DFT and quantum-electrodynamic DFT, which are also discussed here., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)
- Published
- 2023
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28. The Structure of Density-Potential Mapping. Part I: Standard Density-Functional Theory.
- Author
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Penz M, Tellgren EI, Csirik MA, Ruggenthaler M, and Laestadius A
- Abstract
The Hohenberg-Kohn theorem of density-functional theory (DFT) is broadly considered the conceptual basis for a full characterization of an electronic system in its ground state by just the one-body particle density. Part I of this review aims at clarifying the status of the Hohenberg-Kohn theorem within DFT and Part II at different extensions of the theory that include magnetic fields. We collect evidence that the Hohenberg-Kohn theorem does not so much form the basis of DFT, but is rather the consequence of a more comprehensive mathematical framework. Such results are especially useful when it comes to the construction of generalized DFTs., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)
- Published
- 2023
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29. Depressive symptoms are negatively associated with hair N-arachidonoylethanolamine (anandamide) levels: A cross-lagged panel analysis of four annual assessment waves examining hair endocannabinoids and cortisol.
- Author
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Walther A, Kirschbaum C, Wehrli S, Rothe N, Penz M, Wekenborg M, and Gao W
- Subjects
- Humans, Female, Hydrocortisone, Depression diagnosis, Cross-Sectional Studies, Prospective Studies, Cohort Studies, Glycerol, Polyunsaturated Alkamides, Hair, Endocannabinoids, Depressive Disorder, Major diagnosis
- Abstract
Background: The endocannabinoid system (ECS) is increasingly being recognized as key regulatory system coupled with the glucocorticoid system implicated in the pathophysiology of major depressive disorder (MDD). However, prior studies examining the ECS in MDD have been inconclusive, of small sample size or of cross-sectional nature limiting interpretation of causal inferences or time-dependent effects., Methods: In a prospective community-based cohort study including 128 individuals (women: 108), depressive symptoms (PHQ-9) as well as hair cortisol and endocannabinoids were measured annually over four years (T1-T4). Cortisol, N-arachidonoylethanolamine (AEA), and 2-arachidonoyl-sn-glycerol/1-arachidonoyl-sn-glycerol (2-AG/1-AG) were extracted from 3 cm hair segments reflecting cumulative concentrations of the last three months prior sampling., Results: Cross-sectional group comparisons at baseline revealed reduced AEA and cortisol levels in the group with a positive MDD screening compared to individuals with low depressive symptomatology (both p < .05). Cross-lagged panel models showed that AEA levels at T2 were negatively associated with depressive symptoms at T3 (p < .05). Also, depressive symptoms at T3 were negatively associated with AEA levels at T4 (p < .01). The direction of association was reversed for 2-AG/1-AG, as 2-AG/1-AG levels at T1 were positively associated with depressive symptoms at T2 (p < .01)., Conclusions: While cross-sectional analyses suggest higher depressive symptomatology to be associated with reduced AEA and cortisol release, longitudinal analyses reveal that primarily AEA levels are negatively associated with depressive symptoms. These longitudinal associations elucidate time-dependent relationships between depressive symptomatology and the ECS and further highlight AEA as potential treatment target in MDD., (Copyright © 2022 Elsevier Inc. All rights reserved.)
- Published
- 2023
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30. Work values across generations: Development of the New Work Values Scale (NWVS) and examination of generational differences.
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Stiglbauer B, Penz M, and Batinic B
- Abstract
The "battle for talent" requires organizations to more strongly focus on employer branding strategies, and, thus, on work values or work orientations of potential candidates. We therefore developed and validated the New Work Values Scale (Study 1; n = 316), a brief, 28-item, rating scale that covers a broad set of both, instrumental and symbolic, values, relevant for the appraisal of an employers' attractiveness. We also applied the scale to a sample representative to the German online population, to explore the controversially discussed generational differences in work values (Study 2; n = 956). Results revealed that work values associated with sustainable organizational development or basic needs were highly similar across generations. Younger and older generations only differed significantly with regard to how much they valued clarity, money, career, development, stimulation, and relating, all of which are highly plausible from a lifecycle perspective., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Stiglbauer, Penz and Batinic.)
- Published
- 2022
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31. Determining the direction of prediction of the association between parasympathetic dysregulation and exhaustion symptoms.
- Author
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Wekenborg MK, Schwerdtfeger A, Rothe N, Penz M, Walther A, Kirschbaum C, Thayer JF, Wittling RA, and Hill LK
- Subjects
- Burnout, Psychological, Heart Rate physiology, Humans, Prevalence, Autonomic Nervous System, Burnout, Professional
- Abstract
Stress-related exhaustion symptoms have a high prevalence which is only likely to increase further in the near future. Understanding the physiological underpinnings of exhaustion has important implications for accurate diagnosis and the development of effective prevention and intervention programs. Given its integrative role in stress-regulation, the parasympathetic branch of the autonomic nervous systems has been a valid starting point in the exploration of the physiological mechanisms behind exhaustion. The aim of the present study was to examine the directionality and specificity of the association between exhaustion symptoms and vagally-mediated heart rate variability (vmHRV), a relatively pure measure of parasympathetic tone. Exhaustion symptoms and vmHRV were measured at four annually assessment waves (2015-2018) of the Dresden Burnout Study. A total sample of N = 378 participants who attended at least two of the four annual biomarker measurements were included in the present analyses. Cross-lagged multi-level panel modelling adjusting for various covariates (e.g., age, sex, BMI) revealed that vmHRV was meaningfully predictive of exhaustion symptoms and not vice versa. In addition, these effects were specific for exhaustion symptoms as no effect was shown for the other burnout sub-dimensions, or for depressive symptoms. Our findings indicate a clear link between exhaustion symptoms and vmHRV which may hold great potential for both enhancing the diagnosis and treatment of exhaustion symptoms., (© 2022. The Author(s).)
- Published
- 2022
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32. Density-functional theory on graphs.
- Author
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Penz M and van Leeuwen R
- Abstract
The principles of density-functional theory are studied for finite lattice systems represented by graphs. Surprisingly, the fundamental Hohenberg-Kohn theorem is found void, in general, while many insights into the topological structure of the density-potential mapping can be won. We give precise conditions for a ground state to be uniquely v-representable and are able to prove that this property holds for almost all densities. A set of examples illustrates the theory and demonstrates the non-convexity of the pure-state constrained-search functional.
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- 2021
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33. Making ab initio QED functional(s): Nonperturbative and photon-free effective frameworks for strong light-matter coupling.
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Schäfer C, Buchholz F, Penz M, Ruggenthaler M, and Rubio A
- Abstract
Strong light-matter coupling provides a promising path for the control of quantum matter where the latter is routinely described from first principles. However, combining the quantized nature of light with this ab initio tool set is challenging and merely developing as the coupled light-matter Hilbert space is conceptually different and computational cost quickly becomes overwhelming. In this work, we provide a nonperturbative photon-free formulation of quantum electrodynamics (QED) in the long-wavelength limit, which is formulated solely on the matter Hilbert space and can serve as an accurate starting point for such ab initio methods. The present formulation is an extension of quantum mechanics that recovers the exact results of QED for the zero- and infinite-coupling limit and the infinite-frequency as well as the homogeneous limit, and we can constructively increase its accuracy. We show how this formulation can be used to devise approximations for quantum-electrodynamical density-functional theory (QEDFT), which in turn also allows us to extend the ansatz to the full minimal-coupling problem and to nonadiabatic situations. Finally, we provide a simple local density-type functional that takes the strong coupling to the transverse photon degrees of freedom into account and includes the correct frequency and polarization dependence. This QEDFT functional accounts for the quantized nature of light while remaining computationally simple enough to allow its application to a large range of systems. All approximations allow the seamless application to periodic systems., Competing Interests: The authors declare no competing interest., (Copyright © 2021 the Author(s). Published by PNAS.)
- Published
- 2021
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34. Revisiting density-functional theory of the total current density.
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Laestadius A, Penz M, and Tellgren EI
- Abstract
Density-functional theory (DFT) requires an extra variable besides the electron density in order to properly incorporate magnetic-field effects. In a time-dependent setting, the gauge-invariant, total current density takes that role. A peculiar feature of the static ground-state setting is, however, that the gauge-dependent paramagnetic current density appears as the additional variable instead. An alternative, exact reformulation in terms of the total current density has long been sought but to date a work by Diener is the only available candidate. In that work, an unorthodox variational principle was used to establish a ground-state DFT of the total current density as well as an accompanying Hohenberg-Kohn-like result. We here reinterpret and clarify Diener's formulation based on a maximin variational principle. Using simple facts about convexity implied by the resulting variational expressions, we prove that Diener's formulation is unfortunately not capable of reproducing the correct ground-state energy and, furthermore, that the suggested construction of a Hohenberg-Kohn map contains an irreparable mistake., (Creative Commons Attribution license.)
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- 2021
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35. The moderating effect of cortisol and dehydroepiandrosterone on the relation between sleep and depression or burnout.
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Rothe N, Vogel S, Schmelzer K, Kirschbaum C, Penz M, Wekenborg MK, Gao W, and Walther A
- Abstract
For poor sleep quality (SQ) as well as major depressive disorder (MDD) and burnout, a dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been identified. Although poor SQ is often reported as an early symptom of MDD or burnout, it is not clear whether HPA axis-related hormones can influence the association between SQ and MDD or burnout. This manuscript addresses this question by examining HPA axis-related hormones as potential moderators influencing the association between SQ and MDD or burnout. In the fourth annual examination wave of the Dresden Burnout Study, we measured general SQ (including sleep duration and efficiency), depressive and burnout symptoms, and obtained hair samples for quantification of long-term integrated steroid concentrations (cortisol [hC], cortisone [hCn], dehydroepiandrosterone [hDHEA]) from 462 participants (67% female). Data on SQ, depressive and burnout symptoms were available from 342 participants from the preceding examination wave (average time span between examinations 13.2 months). Cross-sectional analyses showed that the negative association between sleep duration and depressive symptoms was buffered by higher levels of hC, and hCn, whereas the negative association between sleep duration and burnout symptoms was buffered by higher levels of hDHEA. The negative association between sleep efficiency and burnout symptoms was intensified by higher levels of hC and hC/hCn ratio and the negative association between general SQ and burnout symptoms was intensified by higher levels of hC/hCn ratio. With regard to longitudinal data, a significant interaction effect between sleep duration and hC/hCn ratio could be detected for burnout symptoms. Our results suggest opposed moderation effects of hair glucocorticoids on the association between SQ and depressive or burnout symptoms. This points toward opposed glucocorticoid receptor functioning in depression and burnout. To fully elucidate the negative consequences of poor SQ on MDD and burnout, the complex underlying mechanisms of action including HPA axis-related hormones need to be investigated in MDD and burnout separately., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Author(s).)
- Published
- 2021
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36. Erratum: Guaranteed Convergence of a Regularized Kohn-Sham Iteration in Finite Dimensions [Phys. Rev. Lett. 123, 037401 (2019)].
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Penz M, Laestadius A, Tellgren EI, Ruggenthaler M, and Lammert PE
- Abstract
This corrects the article DOI: 10.1103/PhysRevLett.123.037401.
- Published
- 2020
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37. The Influence of Workload and Work Flexibility on Work-Life Conflict and the Role of Emotional Exhaustion.
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Buruck G, Pfarr AL, Penz M, Wekenborg M, Rothe N, and Walther A
- Abstract
The purpose of this study is to examine the relationship between contextual work-related factors in terms of job demands (workload- WL ) and job resources (work flexibility- WF ), work-life conflict ( WLC ) and the burnout dimension emotional exhaustion ( EE ) in a large population-based sample. Building on the job demands resources model (JDRM), we have developed the hypothesis that WL has an indirect effect on EE that is mediated by WLC. We conducted a secondary analysis using data from the Dresden Burnout Study (DBS, N = 4246, mean age (SD) = 42.7 years (10.5); 36.4% male). Results from structural equation modelling revealed that EE is positively associated with WL (β = 0.15, p = 0.001) and negatively associated with WF (β = -0.13, p = 0.001), also after accounting for potential confounding variables (demography, depressive symptoms, and lifetime diagnosis of burnout). Both effects are mediated by WLC ( β = 0.18; p = 0.001 and β = 0.08; p = 0.001, respectively) highlighting the important role of WLC in employee health. In summary, WF may help to reduce burnout symptoms in employees, whereas WL may increase them. Study results suggest that both associations depend on WLC levels.
- Published
- 2020
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38. Virial Relations for Electrons Coupled to Quantum Field Modes.
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Theophilou I, Penz M, Ruggenthaler M, and Rubio A
- Abstract
In this work, we present a set of virial relations for many electron systems coupled to both classical and quantum fields, described by the Pauli-Fierz Hamiltonian in dipole approximation and using length gauge. Currently, there is growing interest in solutions of this Hamiltonian because of its relevance for describing molecular systems strongly coupled to photonic modes in cavities and in the possible modification of chemical properties of such systems compared to the ones in free space. The relevance of such virial relations is demonstrated by showing a connection to mass renormalization and by providing an exact way to obtain total energies from potentials in the framework of quantum electrodynamical density functional theory.
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- 2020
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39. Determination of endocannabinoids and N-acylethanolamines in human hair with LC-MS/MS and their relation to symptoms of depression, burnout, and anxiety.
- Author
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Gao W, Walther A, Wekenborg M, Penz M, and Kirschbaum C
- Subjects
- Chromatography, Liquid, Humans, Tandem Mass Spectrometry, Endocannabinoids analysis, Ethanolamines analysis, Hair chemistry
- Abstract
The endocannabinoid system has been implicated in the dynamic regulation of the stress response, fear memory formation, and inflammatory processes. Endocannabinoids (eCBs) and N-acylethanolamines (NAEs) are primarily quantified from serum or cerebrospinal fluid representing acute measures, while no validated method for the quantification of long-term integrated eCBs and NAEs concentrations exists. We here present an online solid phase extraction-liquid chromatography-mass spectrometry method (LC-MS/MS) for quantification of long-term integrated eCBs and NAEs in human hair and examine their association with burnout, depression, and anxiety symptoms. Hair samples were washed with isopropanol and endocannabinoids were extracted from 7.5 mg hair by methanol incubation. A column switching strategy for online solid phase extraction (SPE) was applied, followed by mass spectrometer detection. eCBs and NAEs levels were determined in 207 hair samples from an ongoing longitudinal study and related to individual burnout, depression and anxiety symptoms. The limits of detection were between 0.06 and 6.0 pg mg
-1 , the recoveries of this method were between 87.2% and 114.2%. Hair AEA levels showed a negative correlation with burnout and anxiety symptoms. Participants with clinically relevant burnout and anxiety symptomatology exhibited lower hair AEA levels compared to those participants with low burnout and anxiety symptomatology, while for depressive symptomatology no association was identified. The presented LC-MS/MS method provides a highly specific analytical strategy for the detection of eCBs and NAEs concentrations in human hair and is thus likely to further shed light on the temporal dynamics of eCBs and NAEs secretion. The analysis of eCBs and NAEs in hair emerges as useful strategy in biopsychological research and as a valid and easily implementable method for the retrospective assessment of cumulative long-term eCBs and NAEs secretion., Competing Interests: Declaration of competing interest The authors declare no competing financial interests., (Copyright © 2020 Elsevier B.V. All rights reserved.)- Published
- 2020
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40. Effects of a 6-Week Internet-Based Stress Management Program on Perceived Stress, Subjective Coping Skills, and Sleep Quality.
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Stächele T, Domes G, Wekenborg M, Penz M, Kirschbaum C, and Heinrichs M
- Abstract
Occupational stress management intervention programs are known to be effective in preventing stress-related health burden. Two essential mechanisms underlie this effect: (i) a reduction in perceived stress (e.g., via relaxation-oriented techniques), and (ii) an improvement in coping skills (e.g., via cognitive-behavioral interventions). While relaxation-oriented interventions are more frequently employed in occupational settings, cognitive-behavioral stress management interventions reveal stronger effects on stress-related outcomes. As an effective and economic strategy, the dissemination of stress management programs via the internet is soaring, but most internet-based programs focus on relaxation or reducing perceived stress. In the present study, we examined the effects of a self-guided, cognitive-behavioral 6-week Internet-Based Stress Management (IBSM) program on perceived stress, coping skills, emotional exhaustion, depressive symptoms, and sleep quality. The IBSM consists of six modules focusing on the improvement of stress management skills such as dealing with acute stress, building up resources, or reappraising stress-facilitating cognitions. The participants have to work through the content on a weekly basis, requiring about 30 min per week followed by a transfer task lasting another 30 min. Healthy employees reporting elevated stress were recruited over the Internet and then randomly assigned to the IBSM group or a waiting list control group. A total of 134 participants completed all assessments before and after the training or waiting period. The IBSM group reported lower subjective stress levels after the program than the control group. In addition, the IBSM group exhibited improved coping skills and better sleep quality. Emotional exhaustion was reduced in both groups, while depressive symptoms did not change. These results suggest that a brief, 6-week, cognitive-behavioral internet-based stress management program improves coping skills, sleep quality, and well-being, and reduces the perceived stress of employees. Our results might encourage large-scale studies on the long-term stability and clinical efficacy of internet-based programs. The trial is registered in the German Clinical Trials Register (DRKS00014837) URL. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00014837., (Copyright © 2020 Stächele, Domes, Wekenborg, Penz, Kirschbaum and Heinrichs.)
- Published
- 2020
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41. Unique continuation for the magnetic Schrödinger equation.
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Laestadius A, Benedicks M, and Penz M
- Abstract
The unique-continuation property from sets of positive measure is here proven for the many-body magnetic Schrödinger equation. This property guarantees that if a solution of the Schrödinger equation vanishes on a set of positive measure, then it is identically zero. We explicitly consider potentials written as sums of either one-body or two-body functions, typical for Hamiltonians in many-body quantum mechanics. As a special case, we are able to treat atomic and molecular Hamiltonians. The unique-continuation property plays an important role in density-functional theories, which underpins its relevance in quantum chemistry., (© 2020 The Authors. International Journal of Quantum Chemistry published by Wiley Periodicals, Inc.)
- Published
- 2020
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42. Sleep disturbances in major depressive and burnout syndrome: A longitudinal analysis.
- Author
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Rothe N, Schulze J, Kirschbaum C, Buske-Kirschbaum A, Penz M, Wekenborg MK, and Walther A
- Abstract
Sleep quality (SQ) is considered to be a critical variable in major depressive syndrome (MD) as well as in burnout syndrome (B). Thus far, no study examined the differential influence of these syndromes on SQ. MD and B have been assessed in 4,415 participants at baseline and in 1,396 participants at follow-up based on the Patient Health Questionnaire-9 (PHQ-9) and the Maslach Burnout Inventory-General Survey (MBI-GS). The Pittsburgh Sleep Quality Index was used to measure SQ. Based on the PHQ-9 and MBI-GS at baseline assessment, participants were divided into four groups: a control group, a MD group, a B group, and a comorbid group suffering from MD and B. Multiple regression analyses showed that all groups demonstrate significantly worse SQ than the control group, while individuals with MD showed a lower SQ compared to individuals with B. The comorbid group showed the lowest SQ. Longitudinal analyses showed a significant bidirectional association between major depressive symptoms and SQ, whereas burnout symptoms were predictive for SQ but not vice versa. The study indicates differences between MD and B with regard to SQ, suggesting worse SQ in more severely burdened groups. Major depressive symptoms are bidirectionally linked to SQ, whereas burnout symptoms are only suggested a risk factor for impaired SQ., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to declare., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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43. [Autonomy and Participation As Common Goals of Nursing, Therapy and Social Medicine: Proposal for an Organizational Configuration Model on the Basis of Service Blueprinting].
- Author
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Herold-Majumdar A, Alex C, Gerber H, Penz M, Röder M, Mittelstaedt GV, and Behrens J
- Subjects
- Aged, Germany, Goals, Humans, Models, Organizational, Quality of Life, Nursing, Social Medicine
- Abstract
Background: Every person who is in the need of long-term care (according to German Social Code SGB XI §14) fulfills the requirements of disability according to German Social Code SGB IX, § 2. The right of participation and autonomy must be specially protected and realized for persons with long-term care needs because these persons have a limited capacity to advance their interests. The rights of people in the need of long-term care or assistance are protected not only by the national constitution but also by the UN Disability Rights Convention. Participation is an important principle of these extra-statutory regulations and has an extraordinary significance and individual meaning for quality of life. For concretizing the aim of participation and for realizing participation in daily practice, the following question arises: How must organizations be configured to achieve individual aims of participation for persons with long-term care need, complex health care needs and with potential for rehabilitation across sectoral, disciplinary and professional borders? This analysis focuses on people older than 70 years with geriatric-relevant multimorbidity and with potential for rehabilitation., Aim: The aim of this study was to create a configuration model for the organization of interdisciplinary cooperation in rehabilitation out of a case study and on the basis of the service blueprinting method [1]. In a next step this configuration model can be evaluated concerning its effectiveness for achieving individual participation goals and quality of life of persons with long-term care need and with potential for rehabilitation., Method: For creating the configuration model, the service blueprinting method [1] on the basis of Dervin's sense making theory [11] was applied to a case vignette of geriatric rehabilitation against a background of organization theories and nursing science concepts. With the case study the configuration model can be applied exemplarily at the setting of restorative care, therapy and rehabilitation. With the service blueprinting method, the rehabilitation process is aligned onto the geriatric patient's individual health care needs, perceptions of participation and quality of life., Results: As a result of the sequencing and service blueprinting process we offer a dynamic model for the coordination of responsibility of interdisciplinary rehabilitation teams with a user-centered alignment. Its effectiveness (and side-effects) for interdisciplinary cooperation and for patient's individual goals of participation and quality of life must be evaluated in further studies. A mixed-method design should be used to evaluate objective outcome parameters such as dependency on nursing care, hospital admission rates and subjective outcome parameters such as patient's perception of participation, autonomy and quality of life., Implications for Healthcare Practice: The configuration model can be used for evaluating already implemented geriatric rehabilitation processes and organizations. The configuration model can be used in health care research or organizational research. After more evidence for desirable effects, it can be implemented into the health care system. Side effects should be monitored.This paper was written in cooperation with the working group "Nursing", department "Practical Social Medicine and Rehabilitation" of the German Society of Social Medicine and Prevention (Deutsche Gesellschaft für Sozialmedizin und Prävention DGSMP e.V.)., Competing Interests: Die Autoren geben an, dass kein Interessenkonflikt besteht., (© Georg Thieme Verlag KG Stuttgart · New York.)
- Published
- 2020
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44. Effort-reward imbalance at work is associated with hair cortisol concentrations: Prospective evidence from the Dresden Burnout Study.
- Author
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Penz M, Siegrist J, Wekenborg MK, Rothe N, Walther A, and Kirschbaum C
- Subjects
- Adult, Burnout, Professional psychology, Burnout, Psychological psychology, Female, Hair chemistry, Humans, Hypothalamo-Hypophyseal System metabolism, Longitudinal Studies, Male, Middle Aged, Occupational Health, Occupational Stress metabolism, Pituitary-Adrenal System metabolism, Prospective Studies, Reward, Stress, Psychological metabolism, Surveys and Questionnaires, Workplace psychology, Burnout, Professional metabolism, Hydrocortisone metabolism
- Abstract
Chronic stress experienced at work is considered a major health challenge for modern societies. In fact there is ample evidence that deleterious work environments, based on high efforts in relation to few rewards, substantially augment the risk for a number of highly prevalent diseases (e.g. ischemic heart disease, stroke). One potential pathway mediating these associations involves the stress-related activation of the hypothalamus-pituitary-adrenocortical (HPA) axis with proceeding alterations in the secretion of its main effector hormone cortisol. In this study we assessed a prospective, two-year effect of effort-reward imbalance (ERI) on cortisol secretion, based on a sub sample (N = 150; mean ± SD age: 42.4 ± 11.1; 84.0% female) of the ongoing Dresden Burnout Study (DBS). The provided ERI measures were collected as part of the online baseline and first follow up assessment. Further, cortisol secretion patterns over prolonged periods of time were evaluated in three consecutive years of laboratory baseline and follow up visits. Our findings suggest prospective associations between ERI and cortisol, indicating a blunted cortisol secretion in response to long-term work stress (p < 0.001). Given the regulatory properties of cortisol on various central and peripheral target tissues (e.g. cardiovascular system, liver, adipose tissue), a long-term decrease of cortisol availability can be hypothesized to cause multiple health-challenging consequences. Based on our findings, providing work environments where high efforts are always linked with high rewards have to be considered an important issue for employees health., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2019
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45. The Longitudinal Association of Reduced Vagal Tone With Burnout.
- Author
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Wekenborg MK, Hill LK, Thayer JF, Penz M, Wittling RA, and Kirschbaum C
- Subjects
- Adult, Aged, Female, Heart Rate physiology, Humans, Longitudinal Studies, Male, Middle Aged, Vagus Nerve physiopathology, Young Adult, Autonomic Nervous System physiopathology, Burnout, Psychological physiopathology, Depression physiopathology
- Abstract
Objective: Previous research indicates a link between burnout symptoms and reduced vagally mediated heart rate variability (HRV); however, the directionality of this relationship is still largely unknown. The objective of the present study was to examine the longitudinal relationship between HRV and burnout symptoms for 1 year, with a special focus on the emotional exhaustion (EE) burnout subdimension, which remains inadequately distinguished from overlapping with depressive symptoms., Methods: Here we present HRV and behavioral data from 167 individuals (mean [SD] age = 43.43 [11.78] years; 30.5% male) who attended two biomarker samplings (T1 and T2) of the Dresden Burnout Study approximately 12 months apart., Results: In hierarchical linear regression analyses, T1 HRV significantly inversely predicted T2 overall burnout symptoms (β = -.16; p = .03) and EE (β = -.23; p = .02), adjusting for age, sex, body mass index, adverse health behaviors, and depressive symptoms. Importantly, only high EE at T1 (β = -.22; p = .04), and not the T1 Maslach Burnout Inventor total score, predicted reductions in HRV from T1 to T2., Conclusions: We report for the first time longitudinal evidence that HRV is associated with changes in burnout symptoms, independently of depressive symptoms. Results suggest vagal dysfunction being predictive and specific for burnout symptoms, making HRV a promising starting point for the explanation of biophysiological mechanisms underlying burnout symptoms and cardiovascular diseases. The finding of only EE at T1 being predictive for changes in HRV underscores the importance of exhaustion for modulations in autonomic regulation.
- Published
- 2019
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- View/download PDF
46. Force balance approach for advanced approximations in density functional theories.
- Author
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Tchenkoue MM, Penz M, Theophilou I, Ruggenthaler M, and Rubio A
- Abstract
We propose a systematic and constructive way to determine the exchange-correlation potentials of density-functional theories including vector potentials. The approach does not rely on energy or action functionals. Instead, it is based on equations of motion of current quantities (force balance equations) and is feasible both in the ground-state and the time-dependent settings. This avoids, besides differentiability and causality issues, the optimized-effective-potential procedure of orbital-dependent functionals. We provide straightforward exchange-type approximations for different density functional theories that for a homogeneous system and no external vector potential reduce to the exchange-only local-density and Slater Xα approximations.
- Published
- 2019
- Full Text
- View/download PDF
47. Determination of thyroid hormones in human hair with online SPE LC-MS/MS: Analytical protocol and application in study of burnout.
- Author
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Gao W, Penz M, Wekenborg M, Walther A, and Kirschbaum C
- Subjects
- Adult, Hair chemistry, Humans, Internet Access, Reproducibility of Results, Sensitivity and Specificity, Solid Phase Extraction methods, Thyroid Hormones, Thyroxine analysis, Triiodothyronine analysis, Burnout, Psychological metabolism, Chromatography, Liquid methods, Tandem Mass Spectrometry methods
- Abstract
Thyroid hormones (THs) play a key role within the endocrine system. Incorporated biomarkers in hair can reflect endogenous excretion patterns over several months. We present an online solid phase extraction-liquid chromatography-mass spectrometry (online SPE-LC-MS/MS) method for quantification of THs in human hair and test it in the volunteers suffering from different severity of burnout symptom. THs were extracted from 7.5 mg hair by methanol incubation. Extracts were analyzed with LC-MS/MS in positive electrospray ionization mode. Burnout symptoms were assessed with the Maslach Burnout Inventory-General Survey (MBI-GS). THs levels were determined in 208 hair samples from adults and related to individual MBI-GS score. Intra- and inter-day coefficients of variance were between 3.1% and 10.2%. The recoveries of this method were between 88.5% and 102.1%. Hair T
4 levels correlated significantly with total and free T4 in plasma. Participants with high degree of burnout had significantly higher hair T4 levels and lower T3 /T4 ratio compared to those with no or moderate degree of burnout. A trend towards higher hair T3 levels was observed in subjects with high burnout score. Hair T4 levels showed a significant positive relationship with MBI-GS score, whereas no significant correlation emerged for hair T3 levels. The negative correlation between T3 /T4 ratio and MBI-GS score was also significant. We have developed an online SPE-LC-MS/MS method for measurement of THs in human hair, allowing high analytical specificity and sensitivity. The novel finding of hair THs levels from individuals suffering from chronic stress in burnout underscores the relevance of this method for medical and psychological research., (Copyright © 2019 Elsevier Ltd. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
48. Examining reactivity patterns in burnout and other indicators of chronic stress.
- Author
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Wekenborg MK, von Dawans B, Hill LK, Thayer JF, Penz M, and Kirschbaum C
- Subjects
- Adult, Aged, Burnout, Professional metabolism, Depression metabolism, Depression physiopathology, Hair chemistry, Humans, Hydrocortisone analysis, Hydrocortisone metabolism, Hypothalamo-Hypophyseal System metabolism, Male, Middle Aged, Pituitary-Adrenal System metabolism, Self Report, Burnout, Professional psychology, Stress, Psychological psychology
- Abstract
Introduction: Burnout symptomatology is associated with various negative health consequences; however, the mechanisms underlying these associations remain unclear. One potential pathway involves alterations in the acute stress response. The aims of the present study were to examine burnout-associated alterations in stress-reactivity patterns, during a standardized social stressor compared to a control condition, as well as to examine whether effects associated with greater burnout symptomatology were distinct from other, conceptually overlapping indicators of chronic stress (i.e. depressive symptomatology and elevated hair cortisol concentration [HCC])., Materials and Methods: In a randomized two-factor design a total of 70 employed males with varying burnout symptoms but without evidence of physical or psychiatric disease were exposed to the Trier Social Stress Test for Groups (TSST-G) or a non-stressful control condition. Acute stress reactivity was assessed using self-report stress measures and non-invasive biomarkers. Associations among acute stress reactivity, burnout and depressive symptoms (assessed with self-report measures), as well as HCC were analysed using repeated measure ANCOVAs and moderation analysis., Results: Burnout symptomatology was associated with elevated stress perception independent of the experimental condition. In addition, depressive symptomatology was associated with enhanced anticipatory appraisal, whereas HCC was not related to any subjective stress measure. On a physiological level, burnout and depressive symptomatology, as well as HCC were associated with a pattern of blunted cardiovascular reactivity, however the timing of this effect varied., Conclusion: Our results indicate burnout-associated modulations in stress reactivity, which diverge, at least partly, from other indicators of chronic stress., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
49. Quantum Electrodynamical Bloch Theory with Homogeneous Magnetic Fields.
- Author
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Rokaj V, Penz M, Sentef MA, Ruggenthaler M, and Rubio A
- Abstract
We propose a solution to the problem of Bloch electrons in a homogeneous magnetic field by including the quantum fluctuations of the photon field. A generalized quantum electrodynamical (QED)-Bloch theory from first principles is presented. In the limit of vanishing quantum fluctuations, we recover the standard results of solid-state physics: the fractal spectrum of the Hofstadter butterfly. As a further application, we show how the well-known Landau physics is modified by the photon field and that Landau polaritons emerge. This shows that our QED-Bloch theory does not only allow us to capture the physics of solid-state systems in homogeneous magnetic fields but also novel features that appear at the interface of condensed matter physics and quantum optics.
- Published
- 2019
- Full Text
- View/download PDF
50. Guaranteed Convergence of a Regularized Kohn-Sham Iteration in Finite Dimensions.
- Author
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Penz M, Laestadius A, Tellgren EI, and Ruggenthaler M
- Abstract
The exact Kohn-Sham iteration of generalized density-functional theory in finite dimensions with a Moreau-Yosida regularized universal Lieb functional and an adaptive damping step is shown to converge to the correct ground-state density.
- Published
- 2019
- Full Text
- View/download PDF
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