Publications by authors named "Markus Huber"

74 Publications

Optimisation of airway management strategies: a prospective before-and-after study on events related to airway management.

Br J Anaesth 2021 Sep 14. Epub 2021 Sep 14.

Department of Anaesthesia, University Children's Hospital Zurich - Eleonore Foundation, Zurich, Switzerland. Electronic address:

Background: Poor medical outcomes often result from series of minor events. The present study assessed events related to airway management to determine whether targeted changes to departmental strategies for airway management can reduce the incidence.

Methods: This prospective before-and-after study was performed with ethics committee approval and written informed consent from patients. Major and minor events related to airway management were prospectively recorded for 9 weeks. After implementation of changes to departmental strategies for airway management, events were again prospectively recorded over 9 weeks. Primary outcome was number of cases with events. Secondary outcomes were various predefined events.

Results: At study baseline, 3668 cases and at follow-up 3786 cases were assessed. Cases with events decreased from 566 (15.4%) to 433 (11.4%) (risk ratio [RR]=0.74; 95% confidence interval [CI], 0.66-0.83; P<0.01). As secondary outcomes, the following events decreased: Cormack-Lehane grade 3 or 4 (4.3-2.9%; RR=0.67; 95% CI, 0.52-0.85; P<0.01); difficult bag-mask ventilation (3.8-2.7%; RR=0.69; 95% CI, 0.54-0.89; P<0.01); hypoxaemia (3.8-2.9%; RR=0.75; 95% CI, 0.59-0.96; P=0.03); unplanned use of special equipment (3.2-2.0%; RR=0.62; (95% CI, 0.47-0.83; P<0.01); oesophageal intubation (1.3-0.8%; RR=0.61; 95% CI, 0.39-0.96; P=0.03); bleeding (0.8-0.2%; RR=0.30; 95% CI, 0.14-0.63; P<0.01); insufficient spontaneous breathing (0.3-0.0%; RR=0.09; 95% CI, 0.01-0.68; P<0.01); communication errors (0.1-0.0%; RR=0; 95% CI, 0-NA; P=0.03).

Conclusions: Implementation of changes to departmental strategies for airway management significantly reduced cases with events related to airway management. Analysis of events and implementation of strategies that specifically target identified issues might be key to improving airway management.

Clinical Trial Registration: NCT02743767.
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http://dx.doi.org/10.1016/j.bja.2021.07.030DOI Listing
September 2021

Quantitative terahertz emission nanoscopy with multiresonant near-field probes.

Opt Lett 2021 Aug;46(15):3572-3575

By sampling terahertz waveforms emitted from InAs surfaces, we reveal how the entire, realistic geometry of typical near-field probes drastically impacts the broadband electromagnetic fields. In the time domain, these modifications manifest as a shift in the carrier-envelope phase and emergence of a replica pulse with a time delay dictated by the length of the cantilever. This interpretation is fully corroborated by quantitative simulations of terahertz emission nanoscopy based on the finite element method. Our approach provides a solid theoretical framework for quantitative nanospectroscopy and sets the stage for a reliable description of subcycle, near-field microscopy at terahertz frequencies.
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http://dx.doi.org/10.1364/OL.430400DOI Listing
August 2021

Age, minimum alveolar concentration and choice of depth of sedation monitor: examining the paradox of age when using the Narcotrend monitor: A secondary analysis of an observational study.

Eur J Anaesthesiol 2021 Jul 26. Epub 2021 Jul 26.

From the Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern (DH, CS, MH, FS, HAK) and Department of General Internal Medicine, Canton Hospital Frauenfeld, Frauenfeld, Switzerland (CS).

Background: With an ageing global population, it is important to individualise titration of anaesthetics according to age and by measuring their effect on the brain. A recent study reported that during general surgery, the given concentration of volatile anaesthetics, expressed as a fraction of the minimum alveolar concentration (MAC fraction), decreases by around only 3% per age-decade, which is less than the 6% expected from age-adjusted MAC. Paradoxically, despite the excessive dosing, Bispectral index (BIS) values also increased.

Objective: We planned to investigate the paradox of age when using the Narcotrend depth of anaesthesia monitor.

Design: Secondary analyses of a prospective observational study.

Setting: Tertiary hospital in Switzerland, recordings took place during 2016 and 2017.

Patients: One thousand and seventy-two patients undergoing cardiac surgery entered the study, and 909 with noise-free recordings and isoflurane anaesthesia were included in this analysis.

Intervention: We calculated mean end-tidal MAC fraction and mean index value of the Narcotrend depth of sedation monitor used in the study during the prebypass period. Statistical associations were modelled using linear regression, local weighted regression (LOESS) and a generalised additive model (GAM).

Main Outcome Measures: Primary endpoints in this study were the change in end-tidal MAC fraction and mean Narcotrend index values, both measured per age-decade.

Results: We observed a linear decrease in end-tidal MAC fraction of 3.2% per age-decade [95% confidence interval (CI) -3.97% to -2.38%, P < 0.001], consistent with previous findings. In contrast to the BIS, mean Narcotrend index values decreased with age at 3.0 index points per age-decade (95% CI, -3.55 points to -2.36 points, P < 0.001), a direction of change commensurate with the increasing age-adjusted MAC fraction with patient age. These relationships were consistent regardless of whether age-adjusted MAC was displayed on the anaesthetic machine.

Conclusions: We caution that the 'paradox of age' may in part depend on the choice of depth of sedation monitor.

Trial Registration: ClinicalTrials.gov Identifier: NCT02976584.
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http://dx.doi.org/10.1097/EJA.0000000000001576DOI Listing
July 2021

Outcome in patients with open abdomen treatment for peritonitis: a multidomain approach outperforms single domain predictions.

J Clin Monit Comput 2021 Jul 10. Epub 2021 Jul 10.

Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland.

Numerous patient-related clinical parameters and treatment-specific variables have been identified as causing or contributing to the severity of peritonitis. We postulated that a combination of clinical and surgical markers and scoring systems would outperform each of these predictors in isolation. To investigate this hypothesis, we developed a multivariable model to examine whether survival outcome can reliably be predicted in peritonitis patients treated with open abdomen. This single-center retrospective analysis used univariable and multivariable logistic regression modeling in combination with repeated random sub-sampling validation to examine the predictive capabilities of domain-specific predictors (i.e., demography, physiology, surgery). We analyzed data of 1,351 consecutive adult patients (55.7% male) who underwent open abdominal surgery in the study period (January 1998 to December 2018). Core variables included demographics, clinical scores, surgical indices and indicators of organ dysfunction, peritonitis index, incision type, fascia closure, wound healing, and fascial dehiscence. Postoperative complications were also added when available. A multidomain peritonitis prediction model (MPPM) was constructed to bridge the mortality predictions from individual domains (demographic, physiological and surgical). The MPPM is based on data of n = 597 patients, features high predictive capabilities (area under the receiver operating curve: 0.87 (0.85 to 0.90, 95% CI)) and is well calibrated. The surgical predictor "skin closure" was found to be the most important predictor of survival in our cohort, closely followed by the two physiological predictors SAPS-II and MPI. Marginal effects plots highlight the effect of individual outcomes on the prediction of survival outcome in patients undergoing staged laparotomies for treatment of peritonitis. Although most single indices exhibited moderate performance, we observed that the predictive performance was markedly increased when an integrative prediction model was applied. Our proposed MPPM integrative prediction model may outperform the predictive power of current models.
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http://dx.doi.org/10.1007/s10877-021-00743-8DOI Listing
July 2021

The effective group size for teaching cardiopulmonary resuscitation skills - A randomized controlled simulation trial.

Resuscitation 2021 08 6;165:77-82. Epub 2021 Jun 6.

Department of Anaesthesiology and Pain Medicine, Bern University Hospital, University of Bern, Bern, Switzerland; ERC ResearchNET; School of Medicine, Sigmund Freud University Vienna, Vienna, Austria.

Aim Of The Study: The ideal group size for effective teaching of cardiopulmonary resuscitation is currently under debate. The upper limit is reached when instructors are unable to correct participants' errors during skills practice. This simulation study aimed to define this limit during cardiopulmonary resuscitation teaching.

Methods: Medical students acting as simulated Basic Life Support course participants were instructed to make three different pre-defined Basic Life Support quality errors (e.g., chest compression too fast) in 7 min. Basic Life Support instructors were randomized to groups of 3-10 participants. Instructors were asked to observe the Basic Life Support skills and to correct performance errors. Primary outcome was the maximum group size at which the percentage of correctly identified participants' errors drops below 80%.

Results: Sixty-four instructors participated, eight for each group size. Their average age was 41 ± 9 years and 33% were female, with a median [25th percentile; 75th percentile] teaching experience of 6 [2;11] years. Instructors had taught 3 [1;5] cardiopulmonary resuscitation courses in the year before the study. A logistic binominal regression model showed that the predicted mean percentage of correctly identified participants' errors dropped below 80% for group sizes larger than six.

Conclusion: This randomized controlled simulation trial reveals decreased ability of instructors to detect Basic Life Support performance errors with increased group size. The maximum group size enabling Basic Life Support instructors to correct more than 80% of errors is six. We therefore recommend a maximum instructor-to-participant ratio of 1:6 for cardiopulmonary resuscitation courses.
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http://dx.doi.org/10.1016/j.resuscitation.2021.05.034DOI Listing
August 2021

Structural basis for selective AMPylation of Rac-subfamily GTPases by effector protein 1 (Bep1).

Proc Natl Acad Sci U S A 2021 03;118(12)

Biozentrum, University of Basel, 4056 Basel, Switzerland

Small GTPases of the Ras-homology (Rho) family are conserved molecular switches that control fundamental cellular activities in eukaryotic cells. As such, they are targeted by numerous bacterial toxins and effector proteins, which have been intensively investigated regarding their biochemical activities and discrete target spectra; however, the molecular mechanism of target selectivity has remained largely elusive. Here we report a bacterial effector protein that selectively targets members of the Rac subfamily in the Rho family of small GTPases but none in the closely related Cdc42 or RhoA subfamilies. This exquisite target selectivity of the FIC domain AMP-transferase Bep1 from is based on electrostatic interactions with a subfamily-specific pair of residues in the nucleotide-binding G4 motif and the Rho insert helix. Residue substitutions at the identified positions in Cdc42 enable modification by Bep1, while corresponding Cdc42-like substitutions in Rac1 greatly diminish modification. Our study establishes a structural understanding of target selectivity toward Rac-subfamily GTPases and provides a highly selective tool for their functional analysis.
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http://dx.doi.org/10.1073/pnas.2023245118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8000347PMC
March 2021

Perioperative predictors of early surgical revision and flap-related complications after microvascular free tissue transfer in head and neck reconstructions: a retrospective observational series.

Clin Oral Investig 2021 Sep 8;25(9):5541-5550. Epub 2021 Mar 8.

Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, CH-3010, Bern, Switzerland.

Objectives: The aim of this study was to determine the influence of perioperative fluid management and administration of vasopressors on early surgical revision and flap-related complications in free tissue transfer.

Materials And Methods: Intraoperative amount of fluid and of vasopressors, relevant perioperative parameters, and comorbidities were recorded in 131 patients undergoing head and neck microvascular reconstruction and compared with early surgical complications, defined as interventions requiring surgery after a flap-related complication, and/or other surgical problems in the operating room within 30 days after initial surgery. The relationship between perioperative variables for each revision category was determined using an optimized multiple logistic regression.

Results: The administration of diuretics (p=0.001) as a treatment for perioperative fluid overload and the type of flap (p=0.019) was associated with a higher risk of early surgical revisions. Perioperative fluid overload (p=0.039) is significantly related to flap-related complications. We found no effect of intraoperative administration of vasopressors on early surgical revisions (p=0.8) or on flap-related complications (norepinephrine p=0.6, dobutamine p=0.5).

Conclusion: Perioperative fluid overload is associated with higher risks of early surgical revision and flap-related complications. In contrast, the administration of vasopressors seemed to have no effect on either surgical revision rate or flap-related complications.

Clinical Relevance: In patients receiving microvascular reconstructions, a balanced fluid administration perioperatively and a targeted use of vasopressors should be the necessary strategy to reduce the complication rates in head and neck surgery.
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http://dx.doi.org/10.1007/s00784-021-03864-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8370926PMC
September 2021

Spectrum of scalar and pseudoscalar glueballs from functional methods.

Eur Phys J C Part Fields 2020 20;80(11):1077. Epub 2020 Nov 20.

Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, 8010 Graz, Austria.

We provide results for the spectrum of scalar and pseudoscalar glueballs in pure Yang-Mills theory using a parameter-free fully self-contained truncation of Dyson-Schwinger and Bethe-Salpeter equations. The only input, the scale, is fixed by comparison with lattice calculations. We obtain ground state masses of and for the scalar and pseudoscalar glueballs, respectively, and and for the corresponding first excited states. This is in very good quantitative agreement with available lattice results. Furthermore, we predict masses for the second excited states at and . The quality of the results hinges crucially on the self-consistency of the employed input. The masses are independent of a specific choice for the infrared behavior of the ghost propagator providing further evidence that this only reflects a nonperturbative gauge completion.
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http://dx.doi.org/10.1140/epjc/s10052-020-08649-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7679318PMC
November 2020

Later Age of Onset and Longer Duration of Untreated Psychosis are Associated with Poorer Outcome in Delusional Infestation.

Acta Derm Venereol 2020 Sep 16;100(16):adv00261. Epub 2020 Sep 16.

Liaison Psychiatry, BCUHB, LL13 7TD Wrexham, United Kingdom. E-mail:

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http://dx.doi.org/10.2340/00015555-3625DOI Listing
September 2020

Linear versus Circular Stapler for Gastrojejunal Anastomosis in Laparoscopic Roux-En-Y Gastric Bypass: An Analysis of 211 Cases.

Surg Res Pract 2020 30;2020:4090797. Epub 2020 Jul 30.

Department of Visceral, Thoracic and Vascular Surgery, Triemli Hospital, Birmensdorferstrasse 497, Zurich 8063, Switzerland.

Purpose: Although laparoscopic Roux-en-Y gastric bypass (LRYGB) is a frequently performed bariatric procedure, there is still no consensus on its technical implementation.

Methods: 211 patients treated with LRYGB in a single institution between March 2011 and October 2016 were analyzed retrospectively. A subgroup analysis for the linear (LSA) versus circular stapler technique (CSA) for gastrojejunal anastomosis (GJA) was performed to evaluate complications and outcomes.

Results: 128 (60.6%) patients received GJA with CSA and 83 (39.4%) with LSA. Average weight loss one year after surgery, respectively, BMI after one year of follow-up (kg/m), showed no significant difference. Median surgery time was significantly shorter in the LSA group. If the procedure was performed with CSA, significantly more wound infections occurred.

Conclusions: Both the circular and the linear stapler techniques for gastrojejunal anastomosis in laparoscopic Roux-en-Y gastric bypass are safe methods with comparable outcomes. A disadvantage of CSA is the significantly higher rate of wound infections, a circumstance which requires increased attention.
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http://dx.doi.org/10.1155/2020/4090797DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7414346PMC
July 2020

Emotional intelligence in bipolar-I-disorder: A comparison between patients, unaffected siblings, and control subjects.

Eur Psychiatry 2020 06 29;63(1):e69. Epub 2020 Jun 29.

Department of Psychiatry, Psychotherapy and Psychosomatics: Division of Psychiatry I, Medical University Innsbruck, 6020 Innsbruck, Austria.

Background: Impairments in social and nonsocial cognition have been demonstrated in both patients suffering from bipolar disorder (BD) and their unaffected relatives and might therefore represent a heritable marker of risk. This study investigated the relevance of emotional intelligence (EI) as part of the emotion processing domain of social cognition in this regard.

Methods: A total of 54 outpatients suffering from BD, 54 unaffected siblings, and 80 control subjects were investigated using the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) and the Brief Assessment of Cognition in Schizophrenia (BACS). Analyses of covariance (ANCOVAs) were performed with adjustment for the BACS composite score. The three groups were compared by one-way analysis of variance or chi-square test, depending on the variable type. As the three groups differed significantly in their level of education, additional ANCOVAs with adjustment for education were performed.

Results: Patients achieved significantly lower levels of overall EI and overall nonsocial cognitive functioning compared to unaffected siblings and controls, whereas performance of the latter two groups was comparable in both domains.

Conclusions: Due to comparable levels of EI in unaffected siblings of patients suffering from BD and control subjects, EI assessed by means of the MSCEIT does not represent an endophenotype for BD.
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http://dx.doi.org/10.1192/j.eurpsy.2020.66DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7443786PMC
June 2020

Aberrant Gray Matter Volume and Cortical Surface in Paranoid-Type Delusional Disorder.

Neuropsychobiology 2020 11;79(4-5):335-344. Epub 2020 Mar 11.

Department of Psychiatry, General Hospital Bruneck, Bruneck, Italy.

Introduction: Delusions are core symptoms of schizophrenia-spectrum and related disorders. Despite their clinical relevance, the neural correlates underlying such phenomena are unclear. Recent research suggests that specific delusional content may be associated with distinct neural substrates.

Objective: Here, we used structural magnetic resonance imaging to investigate multiple parameters of brain morphology in patients presenting with paranoid type delusional disorder (pt-DD, n = 14) compared to those of healthy controls (HC, n = 25).

Methods: Voxel- and surface-based morphometry for structural data was used to investigate gray matter volume (GMV), cortical thickness (CT) and gyrification.

Results: Compared to HC, patients with pt-DD showed reduced GMV in bilateral amygdala and right inferior frontal gyrus. Higher GMV in patients was found in bilateral orbitofrontal and in left superior frontal cortices. Patients also had lower CT in frontal and temporal regions. Abnormal gyrification in patients was evident in frontal and temporal areas, as well as in bilateral insula.

Conclusions: The data suggest the presence of aberrant GMV in a right prefrontal region associated with belief evaluation, as well as distinct structural abnormalities in areas that essentially subserve processing of fear, anxiety and threat in patients with pt-DD. It is possible that cortical features of distinct evolutionary and genetic origin, i.e. CT and gyrification, contribute differently to the pathogenesis of pt-DD.
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http://dx.doi.org/10.1159/000505601DOI Listing
April 2021

Abnormal cerebellar volume in somatic vs. non-somatic delusional disorders.

Cerebellum Ataxias 2020 20;7. Epub 2020 Jan 20.

1Department of General Psychiatry, Center for Psychosocial Medicine, Heidelberg University, Heidelberg, Germany.

Background: There is abundant evidence for cerebellar involvement in schizophrenia, where the cerebellum has been suggested to contribute to cognitive, affective and motor dysfunction. More recently, specific cerebellar regions have also been associated with psychotic symptoms, particularly with auditory verbal hallucinations. In contrast, little is known about cerebellar contributions to delusions, and even less is known about whether cerebellar involvement differs by delusional content.

Methods: Using structural magnetic resonance imaging at 1.0 T together with cerebellum-optimized segmentation techniques, we investigated gray matter volume (GMV) in 14 patients with somatic-type delusional disorder (S-DD), 18 patients with non-somatic delusional disorder (NS-DD) and 18 patients with schizophrenia (SZ) with persistent non-somatic delusions. A total of 32 healthy controls (HC) were included. Between-group comparisons were adjusted for age, gender, chlorpromazine equivalents and illness duration.

Results: Compared to HC, S-DD patients showed decreased GMV in left lobule VIIIa. In addition, S-DD patients showed decreased GMV in lobule V and increased GMV in bilateral lobule VIIa/crus II compared to NS-DD. Patients with SZ showed increased GMV in right lobule VI and VIIa/crus I compared to HC. Significant differences between HC and NS-DD were not found.

Conclusions: The data support the notion of cerebellar dysfunction in psychotic disorders. Distinct cerebellar deficits, predominantly linked to sensorimotor processing, may be detected in delusional disorders presenting with predominantly somatic content.
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http://dx.doi.org/10.1186/s40673-020-0111-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6971987PMC
January 2020

Estimating below-canopy light regimes using airborne laser scanning: An application to plant community analysis.

Ecol Evol 2019 Aug 26;9(16):9149-9159. Epub 2019 Jul 26.

WSL Institute for Snow and Avalanche Research SLF Davos Dorf Switzerland.

Light is a key driver of forest biodiversity and functioning. Light regimes beneath tree canopies are mainly driven by the solar angle, topography, and vegetation structure, whose three-dimensional complexity creates heterogeneous light conditions that are challenging to quantify, especially across large areas. Remotely sensed canopy structure data from airborne laser scanning (ALS) provide outstanding opportunities for advancement in this respect. We used ALS point clouds and a digital terrain model to produce hemispherical photographs from which we derived indices of nondirectional diffuse skylight and direct sunlight reaching the understory. We validated our approach by comparing the performance of these indices, as well as canopy closure (CCl) and canopy cover (CCo), for explaining the light conditions experienced by forest plant communities, as indicated by the Landolt indicator values for light ( ) from 43 vegetation surveys along an elevational gradient. We applied variation partitioning to analyze how the independent and joint statistical effects of light, macroclimate, and soil on the spatial variation in plant species composition (i.e., turnover, Simpson dissimilarity, ) depend on light approximation methodology. Diffuse light explained best, followed by direct light, CCl and CCo (  = .31, .23, .22, and .22, respectively). The combination of diffuse and direct light improved the model performance for compared with CCl and CCo (  = .30, .27 and .24, respectively). The independent effect of macroclimate on dropped from an of .15 to .10 when diffuse light and direct light were included. The ALS methods presented here outperform conventional approximations of below-canopy light conditions, which can now efficiently be quantified along entire horizontal and vertical forest gradients, even in topographically complex environments such as mountains. The effect of macroclimate on forest plant communities is prone to be overestimated if local light regimes and associated microclimates are not accurately accounted for.
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http://dx.doi.org/10.1002/ece3.5462DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6706208PMC
August 2019

Nanoscale Near-Field Tomography of Surface States on (BiSb)Te.

Nano Lett 2018 12 19;18(12):7515-7523. Epub 2018 Nov 19.

Department of Physics , University of Regensburg , 93040 Regensburg , Germany.

Three-dimensional topological insulators (TIs) have attracted tremendous interest for their possibility to host massless Dirac Fermions in topologically protected surface states (TSSs), which may enable new kinds of high-speed electronics. However, recent reports have outlined the importance of band bending effects within these materials, which results in an additional two-dimensional electron gas (2DEG) with finite mass at the surface. TI surfaces are also known to be highly inhomogeneous on the nanoscale, which is masked in conventional far-field studies. Here, we use near-field microscopy in the mid-infrared spectral range to probe the local surface properties of custom-tailored (BiSb)Te structures with nanometer precision in all three spatial dimensions. Applying nanotomography and nanospectroscopy, we reveal a few-nanometer-thick layer of high surface conductivity and retrieve its local dielectric function without assuming any model for the spectral response. This allows us to directly distinguish between different types of surface states. An intersubband transition within the massive 2DEG formed by quantum confinement in the bent conduction band manifests itself as a sharp, surface-bound, Lorentzian-shaped resonance. An additional broadband background in the imaginary part of the dielectric function may be caused by the TSS. Tracing the intersubband resonance with nanometer spatial precision, we observe changes of its frequency, likely originating from local variations of doping or/and the mixing ratio between Bi and Sb. Our results highlight the importance of studying the surfaces of these novel materials on the nanoscale to directly access the local optical and electronic properties via the dielectric function.
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http://dx.doi.org/10.1021/acs.nanolett.8b03008DOI Listing
December 2018

Interactive Molecular Graphics for Augmented Reality Using HoloLens.

J Integr Bioinform 2018 Jun 13;15(2). Epub 2018 Jun 13.

Visualisation Research Centre (VISUS), University of Stuttgart, 70569 Stuttgart, Germany.

Immersive technologies like stereo rendering, virtual reality, or augmented reality (AR) are often used in the field of molecular visualisation. Modern, comparably lightweight and affordable AR headsets like Microsoft's HoloLens open up new possibilities for immersive analytics in molecular visualisation. A crucial factor for a comprehensive analysis of molecular data in AR is the rendering speed. HoloLens, however, has limited hardware capabilities due to requirements like battery life, fanless cooling and weight. Consequently, insights from best practises for powerful desktop hardware may not be transferable. Therefore, we evaluate the capabilities of the HoloLens hardware for modern, GPU-enabled, high-quality rendering methods for the space-filling model commonly used in molecular visualisation. We also assess the scalability for large molecular data sets. Based on the results, we discuss ideas and possibilities for immersive molecular analytics. Besides more obvious benefits like the stereoscopic rendering offered by the device, this specifically includes natural user interfaces that use physical navigation instead of the traditional virtual one. Furthermore, we consider different scenarios for such an immersive system, ranging from educational use to collaborative scenarios.
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http://dx.doi.org/10.1515/jib-2018-0005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6167047PMC
June 2018

Longer Duration of Untreated Psychosis is Associated with Poorer Outcomes for Patients with Delusional Infestation.

Acta Derm Venereol 2018 Oct;98(9):848-854

Department of Psychiatry and Psychosomatics, I. M. Sechenov First Moscow State Medical University, Mental Health Research Center, 127006 Moscow, Russia.

We examined the association between the duration of untreated psychosis and outcome for patients with delusional infestation. This multi-centre international study included 211 consecutive patients. Illness severity was evaluated at first presentation and outcome was measured with the Clinical Global Impression scale (CGI) at baseline and follow-up. A regression analysis showed a clear clinical and statistically significant association between shorter duration of untreated psychosis and better outcome at follow-up. Patients with a duration of untreated psychosis of less than one year showed a CGI-S change from 5.37 to 2.07; those with a duration of untreated psychosis of 1-5 years a change from 5.48 to 2.59, and those with a duration of untreated psychosis of >5 years a change from 5.59 to 3.37. This difference of 1.1 CGI points between the groups resembles a clinically relevant difference in patient outcome. Our results suggest that longer duration of untreated psychosis in patients with delusional infestation is associated with significantly less favour-able clinical outcomes.
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http://dx.doi.org/10.2340/00015555-2888DOI Listing
October 2018

Fronto-parietal coding of goal-directed actions performed by artificial agents.

Hum Brain Mapp 2018 03 5;39(3):1145-1162. Epub 2017 Dec 5.

German Center for Vertigo and Balance Disorders DSGZ, Ludwig-Maximilian University Munich, München, Germany.

With advances in technology, artificial agents such as humanoid robots will soon become a part of our daily lives. For safe and intuitive collaboration, it is important to understand the goals behind their motor actions. In humans, this process is mediated by changes in activity in fronto-parietal brain areas. The extent to which these areas are activated when observing artificial agents indicates the naturalness and easiness of interaction. Previous studies indicated that fronto-parietal activity does not depend on whether the agent is human or artificial. However, it is unknown whether this activity is modulated by observing grasping (self-related action) and pointing actions (other-related action) performed by an artificial agent depending on the action goal. Therefore, we designed an experiment in which subjects observed human and artificial agents perform pointing and grasping actions aimed at two different object categories suggesting different goals. We found a signal increase in the bilateral inferior parietal lobule and the premotor cortex when tool versus food items were pointed to or grasped by both agents, probably reflecting the association of hand actions with the functional use of tools. Our results show that goal attribution engages the fronto-parietal network not only for observing a human but also a robotic agent for both self-related and social actions. The debriefing after the experiment has shown that actions of human-like artificial agents can be perceived as being goal-directed. Therefore, humans will be able to interact with service robots intuitively in various domains such as education, healthcare, public service, and entertainment.
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http://dx.doi.org/10.1002/hbm.23905DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6866499PMC
March 2018

Regional gray matter volume and structural network strength in somatic vs. non-somatic delusional disorders.

Prog Neuropsychopharmacol Biol Psychiatry 2018 03 24;82:115-122. Epub 2017 Nov 24.

Department of Psychiatry and Psychotherapy III, Ulm University, Germany.

Background: Monothematic delusional disorders are characterized by a single tenacious belief. They provide a great opportunity to study underlying brain structures in the absence of confounding symptoms that accompany delusions in schizophrenia. Delusional beliefs include persecution, jealousy or somatic delusions including infestation. It is unclear whether specific delusional content is associated with distinct neural substrates.

Methods: We used magnetic resonance imaging in patients presenting with somatic vs. non-somatic delusional disorders. Patients with delusional infestation (DI, n=18), and individuals with non-somatic delusional disorders (n=19) were included, together with healthy volunteers (n=20). Uni- and multivariate techniques for structural data analysis were applied to provide a comprehensive characterization of abnormal brain volume at both the regional and neural network level.

Results: Patients with DI showed lower gray matter volume in thalamic, striatal (putamen), insular and medial prefrontal brain regions in contrast to non-somatic delusional disorders and healthy controls. Importantly, these differences were consistently detected at regional and network level. Compared to healthy controls, patients with delusional disorders other than DI showed lower gray matter volume in temporal cortical regions.

Conclusion: The data support the notion that dysfunctional somatosensory and peripersonal networks could mediate somatic delusions in patients with DI in contrast to delusional disorders without somatic content. The data also suggest putative content-specific neural signatures in delusional disorders and in delusion formation per se.
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http://dx.doi.org/10.1016/j.pnpbp.2017.11.022DOI Listing
March 2018

Cloth Animation Retrieval Using a Motion-Shape Signature.

IEEE Comput Graph Appl 2017 Nov-Dec;37(6):52-64

In cloth simulation, the behavior of textiles largely depends on initial conditions, parameters, and simulation techniques. Usually, several combinations of those aspects are altered until a simulation setting is found to create a satisfying animation. However, if an initial condition, such as a collision object, is changed afterward or the cloth behavior is transferred to a different scene, the existing set of simulation parameters could no longer be suitable for the desired look. In this case, it is difficult to find a new configuration by changing parameters manually and to determine if it conforms the desired properties. This article introduces a feature vector that is used as a motion-shape signature to capture the spatiotemporal shape characteristics of cloth and can be applied as a similarity measure for physics-based cloth animations.
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http://dx.doi.org/10.1109/MCG.2017.4031068DOI Listing
October 2018

Is Emotional Intelligence Impaired in Unaffected Siblings of Patients with Schizophrenia?

J Int Neuropsychol Soc 2017 08 13;23(7):577-583. Epub 2017 Jun 13.

1Medical University Innsbruck;Department of Psychiatry,Psychotherapy and Psychosomatics,Division of Psychiatry I,Innsbruck,Austria.

Objectives: Social cognitive deficits have been discussed to be endophenotypes for schizophrenia and other serious mental illnesses. The current study aimed to assess emotional intelligence (EI) in unaffected siblings of schizophrenia patients to investigate its potential role as endophenotype for schizophrenia.

Methods: EI was measured in 56 schizophrenia patients, 57 unaffected siblings, and 127 healthy control subjects by using the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). In addition, non-social cognition was assessed with the Brief Assessment of Cognition in Schizophrenia (BACS). Linear mixed models with compound symmetric correlation structure were used for of the three groups with respect to EI and non-social cognition.

Results: Schizophrenia patients showed significantly lower overall EI and performed significantly worse in three out of four MSCEIT branches compared to unaffected siblings and control subjects, whereas the two latter groups had comparable EI levels. Similar performance patterns (patients
Conclusions: Based on our results, EI as measured with the MSCEIT does not seem to represent a marker of risk for schizophrenia. Further investigations should concentrate on other EI measures to reassess this finding. (JINS, 2017, 23, 577-583).
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http://dx.doi.org/10.1017/S135561771700042XDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5749612PMC
August 2017

Cortical features of distinct developmental trajectories in patients with delusional infestation.

Prog Neuropsychopharmacol Biol Psychiatry 2017 06 28;76:72-79. Epub 2017 Feb 28.

Center for Psychosocial Medicine, Department of General Psychiatry, Heidelberg University, Germany.

Background: Although there is strong neuroimaging evidence that cortical alterations are a core feature of schizophrenia spectrum disorders, it still remains unclear to what extent such abnormalities occur in monothematic delusional disorders. In individuals with delusional infestation (DI), the delusional belief to be infested with pathogens, previous structural MRI studies have shown prefrontal, temporal, parietal, insular, thalamic and striatal gray matter volume changes. Differential contributions of cortical features of evolutionary and genetic origin (such as cortical thickness, area and folding) which may distinctly contribute to DI pathophysiology are unclear at present.

Methods: In this study, 18 patients with DI and 20 healthy controls (HC) underwent MRI scanning at 1.0T. Using surface-based analyses we calculated cortical thickness, surface area and local gyrification index (LGI). Whole-brain differences between patients and controls were investigated.

Results: Surface analyses revealed frontoparietal patterns exhibiting altered cortical thickness, surface area and LGI in DI patients compared to controls. Higher cortical thickness was found in the right medial orbitofrontal cortex (p<0.05, cluster-wise probability [CWP] corrected). Smaller surface area in patients was found in the left inferior temporal gyrus, the precuneus, the pars orbitalis of the right frontal gyrus, and the lingual gyrus (p<0.05, CWP corr.). Lower LGI was found in the left postcentral, bilateral precentral, right middle temporal, inferior parietal, and superior parietal gyri (p<0.01, CWP corr.).

Conclusion: This study lends further support to the hypothesis that cortical features of distinct evolutionary and genetic origin differently contribute to the pathogenesis of delusional disorders. Regions in which atrophy was observed are part of neural circuits associated with perception, visuospatial control and self-awareness. The data are in line with the notion of a content-specific neural signature of DI.
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http://dx.doi.org/10.1016/j.pnpbp.2017.02.018DOI Listing
June 2017

On non-primitively divergent vertices of Yang-Mills theory.

Authors:
Markus Q Huber

Eur Phys J C Part Fields 2017 2;77(11):733. Epub 2017 Nov 2.

Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, 8010 Graz, Austria.

Two correlation functions of Yang-Mills beyond the primitively divergent ones, the two-ghost-two-gluon and the four-ghost vertices, are calculated and their influence on lower vertices is examined. Their full (transverse) tensor structure is taken into account. As input, a solution of the full two-point equations - including two-loop terms - is used that respects the resummed perturbative ultraviolet behavior. A clear hierarchy is found with regard to the color structure that reduces the number of relevant dressing functions. The impact of the two-ghost-two-gluon vertex on the three-gluon vertex is negligible, which is explained by the fact that all non-small dressing functions drop out due to their color factors. Only in the ghost-gluon vertex a small net effect below is seen. The four-ghost vertex is found to be extremely small in general. Since these two four-point functions do not enter into the propagator equations, these findings establish their small overall effect on lower correlation functions.
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http://dx.doi.org/10.1140/epjc/s10052-017-5310-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6956911PMC
November 2017

Femtosecond photo-switching of interface polaritons in black phosphorus heterostructures.

Nat Nanotechnol 2017 03 12;12(3):207-211. Epub 2016 Dec 12.

Department of Physics, University of Regensburg, 93040 Regensburg, Germany.

The possibility of hybridizing collective electronic motion with mid-infrared light to form surface polaritons has made van der Waals layered materials a versatile platform for extreme light confinement and tailored nanophotonics. Graphene and its heterostructures have attracted particular attention because the absence of an energy gap allows plasmon polaritons to be tuned continuously. Here, we introduce black phosphorus as a promising new material in surface polaritonics that features key advantages for ultrafast switching. Unlike graphene, black phosphorus is a van der Waals bonded semiconductor, which enables high-contrast interband excitation of electron-hole pairs by ultrashort near-infrared pulses. Here, we design a SiO/black phosphorus/SiO heterostructure in which the surface phonon modes of the SiO layers hybridize with surface plasmon modes in black phosphorus that can be activated by photo-induced interband excitation. Within the Reststrahlen band of SiO, the hybrid interface polariton assumes surface-phonon-like properties, with a well-defined frequency and momentum and excellent coherence. During the lifetime of the photogenerated electron-hole plasma, coherent hybrid polariton waves can be launched by a broadband mid-infrared pulse coupled to the tip of a scattering-type scanning near-field optical microscopy set-up. The scattered radiation allows us to trace the new hybrid mode in time, energy and space. We find that the surface mode can be activated within ∼50 fs and disappears within 5 ps, as the electron-hole pairs in black phosphorus recombine. The excellent switching contrast and switching speed, the coherence properties and the constant wavelength of this transient mode make it a promising candidate for ultrafast nanophotonic devices.
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http://dx.doi.org/10.1038/nnano.2016.261DOI Listing
March 2017

"Taller and Shorter": Human 3-D Spatial Memory Distorts Familiar Multilevel Buildings.

PLoS One 2015 28;10(10):e0141257. Epub 2015 Oct 28.

Clinical Neuroscience, Ludwig-Maximilians-University Munich, Germany; German Center for Vertigo and Balance Disorders-IFBLMU (DSGZ), Ludwig-Maximilians-University Munich, Germany; Department of Neurology, Ludwig-Maximilians-University Munich, Germany; Center for Sensorimotor Research; Ludwig-Maximilians-University Munich, Germany; Bernstein Center for Computational Neuroscience; Ludwig-Maximilians-University Munich, Germany.

Animal experiments report contradictory findings on the presence of a behavioural and neuronal anisotropy exhibited in vertical and horizontal capabilities of spatial orientation and navigation. We performed a pointing experiment in humans on the imagined 3-D direction of the location of various invisible goals that were distributed horizontally and vertically in a familiar multilevel hospital building. The 21 participants were employees who had worked for years in this building. The hypothesis was that comparison of the experimentally determined directions and the true directions would reveal systematic inaccuracy or dimensional anisotropy of the localizations. The study provides first evidence that the internal representation of a familiar multilevel building was distorted compared to the dimensions of the true building: vertically 215% taller and horizontally 51% shorter. This was not only demonstrated in the mathematical reconstruction of the mental model based on the analysis of the pointing experiments but also by the participants' drawings of the front view and the ground plan of the building. Thus, in the mental model both planes were altered in different directions: compressed for the horizontal floor plane and stretched for the vertical column plane. This could be related to human anisotropic behavioural performance of horizontal and vertical navigation in such buildings.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0141257PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4624999PMC
June 2016

Volumetric quantitative characterization of human patellar cartilage with topological and geometrical features on phase-contrast X-ray computed tomography.

Med Biol Eng Comput 2015 Nov 4;53(11):1211-20. Epub 2015 Jul 4.

Departments of Imaging Sciences and Biomedical Engineering, University of Rochester, Rochester, NY, USA.

Phase-contrast X-ray computed tomography (PCI-CT) has attracted significant interest in recent years for its ability to provide significantly improved image contrast in low absorbing materials such as soft biological tissue. In the research context of cartilage imaging, previous studies have demonstrated the ability of PCI-CT to visualize structural details of human patellar cartilage matrix and capture changes to chondrocyte organization induced by osteoarthritis. This study evaluates the use of geometrical and topological features for volumetric characterization of such chondrocyte patterns in the presence (or absence) of osteoarthritic damage. Geometrical features derived from the scaling index method (SIM) and topological features derived from Minkowski Functionals were extracted from 1392 volumes of interest (VOI) annotated on PCI-CT images of ex vivo human patellar cartilage specimens. These features were subsequently used in a machine learning task with support vector regression to classify VOIs as healthy or osteoarthritic; classification performance was evaluated using the area under the receiver operating characteristic curve (AUC). Our results show that the classification performance of SIM-derived geometrical features (AUC: 0.90 ± 0.09) is significantly better than Minkowski Functionals volume (AUC: 0.54 ± 0.02), surface (AUC: 0.72 ± 0.06), mean breadth (AUC: 0.74 ± 0.06) and Euler characteristic (AUC: 0.78 ± 0.04) (p < 10(-4)). These results suggest that such geometrical features can provide a detailed characterization of the chondrocyte organization in the cartilage matrix in an automated manner, while also enabling classification of cartilage as healthy or osteoarthritic with high accuracy. Such features could potentially serve as diagnostic imaging markers for evaluating osteoarthritis progression and its response to different therapeutic intervention strategies.
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http://dx.doi.org/10.1007/s11517-015-1340-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4630098PMC
November 2015

How to approach delusional infestation.

BMJ 2015 Apr 1;350:h1328. Epub 2015 Apr 1.

Department of Psychiatry and Psychotherapy III, University of Ulm, Ulm, Germany.

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http://dx.doi.org/10.1136/bmj.h1328DOI Listing
April 2015

Integrating dimension reduction and out-of-sample extension in automated classification of ex vivo human patellar cartilage on phase contrast X-ray computed tomography.

PLoS One 2015 24;10(2):e0117157. Epub 2015 Feb 24.

Departments of Imaging Sciences and Biomedical Engineering, University of Rochester Medical Center, Rochester, New York, USA; Faculty of Medicine and Institute of Clinical Radiology, Ludwig Maximilian University, Munich, Germany.

Phase contrast X-ray computed tomography (PCI-CT) has been demonstrated as a novel imaging technique that can visualize human cartilage with high spatial resolution and soft tissue contrast. Different textural approaches have been previously investigated for characterizing chondrocyte organization on PCI-CT to enable classification of healthy and osteoarthritic cartilage. However, the large size of feature sets extracted in such studies motivates an investigation into algorithmic feature reduction for computing efficient feature representations without compromising their discriminatory power. For this purpose, geometrical feature sets derived from the scaling index method (SIM) were extracted from 1392 volumes of interest (VOI) annotated on PCI-CT images of ex vivo human patellar cartilage specimens. The extracted feature sets were subject to linear and non-linear dimension reduction techniques as well as feature selection based on evaluation of mutual information criteria. The reduced feature set was subsequently used in a machine learning task with support vector regression to classify VOIs as healthy or osteoarthritic; classification performance was evaluated using the area under the receiver-operating characteristic (ROC) curve (AUC). Our results show that the classification performance achieved by 9-D SIM-derived geometric feature sets (AUC: 0.96 ± 0.02) can be maintained with 2-D representations computed from both dimension reduction and feature selection (AUC values as high as 0.97 ± 0.02). Thus, such feature reduction techniques can offer a high degree of compaction to large feature sets extracted from PCI-CT images while maintaining their ability to characterize the underlying chondrocyte patterns.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0117157PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4339581PMC
November 2015

Volumetric Characterization of Human Patellar Cartilage Matrix on Phase Contrast X-Ray Computed Tomography.

Proc SPIE Int Soc Opt Eng 2015 Feb 19;9417. Epub 2015 Mar 19.

Departments of Imaging Sciences and Biomedical Engineering, University of Rochester, New York, United States.

Phase contrast X-ray computed tomography (PCI-CT) has recently emerged as a novel imaging technique that allows visualization of cartilage soft tissue, subsequent examination of chondrocyte patterns, and their correlation to osteoarthritis. Previous studies have shown that 2D texture features are effective at distinguishing between healthy and osteoarthritic regions of interest annotated in the radial zone of cartilage matrix on PCI-CT images. In this study, we further extend the texture analysis to 3D and investigate the ability of volumetric texture features at characterizing chondrocyte patterns in the cartilage matrix for purposes of classification. Here, we extracted volumetric texture features derived from Minkowski Functionals and gray-level co-occurrence matrices (GLCM) from 496 volumes of interest (VOI) annotated on PCI-CT images of human patellar cartilage specimens. The extracted features were then used in a machine-learning task involving support vector regression to classify ROIs as healthy or osteoarthritic. Classification performance was evaluated using the area under the receiver operating characteristic (ROC) curve (AUC). The best classification performance was observed with GLCM features correlation (AUC = 0.83 ± 0.06) and homogeneity (AUC = 0.82 ± 0.07), which significantly outperformed all Minkowski Functionals ( < 0.05). These results suggest that such quantitative analysis of chondrocyte patterns in human patellar cartilage matrix involving GLCM-derived statistical features can distinguish between healthy and osteoarthritic tissue with high accuracy.
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http://dx.doi.org/10.1117/12.2082084DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5564233PMC
February 2015
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