Endoscopic submucosal dissection for superficial esophageal squamous cell carcinoma: long-term follow-up in a Western center

Andreas Probst,Alanna Ebigbo,Stefan Eser,Carola Fleischmann,Tina Schaller,Bruno Märkl,Stefan Schiele,Bernd Geissler,Gernot Müller,Helmut Messmann 대한소화기내시경학회 2023 Clinical Endoscopy Vol.56 No.1

Background/Aims: Endoscopic submucosal dissection (ESD) has been established as a treatment modality for superficial esophagealsquamous cell carcinoma (ESCC). Long-term follow-up data are lacking in Western countries. The aim of this study was to analyzelong-term survival in a Western center. Methods: Patients undergoing ESD for ESCC were included. The analysis was performed retrospectively using a prospectively collecteddatabase. Results: R0 resection rate was 96.7% (59/61 lesions in 58 patients). Twenty-seven patients (46.6%) fulfilled the curative resection criteria(M1/M2) (group A), 11 patients (19.0%) had M3 lesions without lymphovascular invasion (LVI) (group B), and 20 patients (34.5%)had lesions with submucosal invasion or LVI (group C). Additional treatment was recommended after non-curative resection. It wasnot performed in 20/31 patients (64.5%), mainly because of comorbidities (75%). Twenty-nine out of 58 (50.0%) patients died during amean follow-up of 3.7 years. Death was related to ESCC in 17.2% (5/29) of patients. The disease-specific survival rate after curative resectionwas 100%. Overall survival rates after 5 years were 61.5%, 63.6% and 28.1% for groups A, B, and C, respectively. The overallsurvival was significantly worse after non-curative resection (p=0.038). Conclusions: Non-curative resection is frequent after ESD for ESCC in Western patients. The long-term prognosis is limited andmainly determined by comorbidity. Early diagnosis and pre-interventional assessments need to be improved.

Topological contact dynamics I: symplectization and applications of the energy-capacity inequality

Mü,ller, Stefan,Spaeth, Peter Walter de Gruyter GmbH 2015 Advances in geometry Vol.15 No.3

<B>Abstract</B><P>We introduce topological contact dynamics of a smooth manifold carrying a cooriented contact structure, generalizing previous work in the case of a symplectic structure [27] or a contact form [5]. A topological contact isotopy is not generated by a vector field; nevertheless, the group identities, the transformation law, and classical uniqueness results in the smooth case extend to topological contact isotopies and homeomorphisms, giving rise to an extension of smooth contact dynamics to topological dynamics. Our approach is via symplectization of a contact manifold, and our main tools are an energy-capacity inequality we prove for contact diffeomorphisms, combined with techniques from measure theory on oriented manifolds. We establish non-degeneracy of a Hofer-like bi-invariant pseudo-metric on the group of strictly contact diffeomorphisms constructed in [4]. The topological automorphism group of the contact structure exhibits rigidity properties analogous to those of symplectic diffeomorphisms, including C</P>

On multi-authority ciphertext-policy attribute-based encryption

Sascha Müller,Stefan Katzenbeisser,Claudia Eckert 대한수학회 2009 대한수학회보 Vol.46 No.4

In classical encryption schemes, data is encrypted under a single key that is associated with a user or group. In Ciphertext-Policy Attribute-Based Encryption(CP-ABE) keys are associated with attributes of users, given to them by a central trusted authority, and data is encrypted under a logical formula over these attributes. We extend this idea to the case where an arbitrary number of independent parties can be present to maintain attributes and their corresponding secret keys. We present a scheme for multi-authority CP-ABE, propose the first two constructions that fully implement the scheme, and prove their security against chosen plaintext attacks. In classical encryption schemes, data is encrypted under a single key that is associated with a user or group. In Ciphertext-Policy Attribute-Based Encryption(CP-ABE) keys are associated with attributes of users, given to them by a central trusted authority, and data is encrypted under a logical formula over these attributes. We extend this idea to the case where an arbitrary number of independent parties can be present to maintain attributes and their corresponding secret keys. We present a scheme for multi-authority CP-ABE, propose the first two constructions that fully implement the scheme, and prove their security against chosen plaintext attacks.

Advanced dual fluidized bed steam gasification of wood and lignite with calcite as bed material

Florian Benedikt,Josef Fuchs,Johannes Christian Schmid,Stefan Müller,Hermann Hofbauer 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.9

This paper presents experimental results with a new generation of a 100 kWth dual fluidized bed steam gasification pilot plant with calcite as bed material, converting wood and lignite in separate test runs into product gas. The results are compared to experiments with the same fuels with olivine as bed material and the previous generation of the gasification pilot plant at TU Wien. The highly catalytic active calcium oxide shifted the product gas composition towards higher hydrogen and carbon dioxide and lower carbon monoxide content. The tar amount was decreased and the tar composition changed, resulting in lower tar dew points. The dust content in the product gas was reduced with the advanced pilot plant design with calcite in comparison to the classic design with olivine. Therefore, attrition of bed material was decreased by utilizing the advanced design and calcite with its benefits can be used without profuse continuous replacement of bed material.

sGDML: Constructing accurate and data efficient molecular force fields using machine learning

Chmiela, Stefan,Sauceda, Huziel E.,Poltavsky, Igor,Mü,ller, Klaus-Robert,Tkatchenko, Alexandre Elsevier 2019 Computer physics communications Vol.240 No.-

<P><B>Abstract</B></P> <P>We present an optimized implementation of the recently proposed symmetric gradient domain machine learning (sGDML) model. The sGDML model is able to faithfully reproduce global potential energy surfaces (PES) for molecules with a few dozen atoms from a limited number of user-provided reference molecular conformations and the associated atomic forces. Here, we introduce a Python software package to reconstruct and evaluate custom sGDML force fields (FFs), without requiring in-depth knowledge about the details of the model. A user-friendly command-line interface offers assistance through the complete process of model creation, in an effort to make this novel machine learning approach accessible to broad practitioners. Our paper serves as a documentation, but also includes a practical application example of how to reconstruct and use a PBE0+MBD FF for paracetamol. Finally, we show how to interface sGDML with the FF simulation engines ASE (Larsen et al., 2017) and i-PI (Kapil et al., 2019) to run numerical experiments, including structure optimization, classical and path integral molecular dynamics and nudged elastic band calculations.</P>

Optimizing the regularization for image reconstruction of cerebral diffuse optical tomography

Habermehl, Christina,Steinbrink, Jens,Mü,ller, Klaus-Robert,Haufe, Stefan SPIE - International Society for Optical Engineeri 2014 JOURNAL OF BIOMEDICAL OPTICS Vol.19 No.9

<P>Functional near-infrared spectroscopy (fNIRS) is an optical method for noninvasively determining brain activation by estimating changes in the absorption of near-infrared light. Diffuse optical tomography (DOT) extends fNIRS by applying overlapping high density measurements, and thus providing a three-dimensional imaging with an improved spatial resolution. Reconstructing brain activation images with DOT requires solving an underdetermined inverse problem with far more unknowns in the volume than in the surface measurements. All methods of solving this type of inverse problem rely on regularization and the choice of corresponding regularization or convergence criteria. While several regularization methods are available, it is unclear how well suited they are for cerebral functional DOT in a semi-infinite geometry. Furthermore, the regularization parameter is often chosen without an independent evaluation, and it may be tempting to choose the solution that matches a hypothesis and rejects the other. In this simulation study, we start out by demonstrating how the quality of cerebral DOT reconstructions is altered with the choice of the regularization parameter for different methods. To independently select the regularization parameter, we propose a cross-validation procedure which achieves a reconstruction quality close to the optimum. Additionally, we compare the outcome of seven different image reconstruction methods for cerebral functional DOT. The methods selected include reconstruction procedures that are already widely used for cerebral DOT [minimum l2-norm estimate (l2MNE) and truncated singular value decomposition], recently proposed sparse reconstruction algorithms [minimum l1- and a smooth minimum l0-norm estimate (l1MNE, l0MNE, respectively)] and a depth- and noise-weighted minimum norm (wMNE). Furthermore, we expand the range of algorithms for DOT by adapting two EEG-source localization algorithms [sparse basis field expansions and linearly constrained minimum variance (LCMV) beamforming]. Independent of the applied noise level, we find that the LCMV beamformer is best for single spot activations with perfect location and focality of the results, whereas the minimum l1-norm estimate succeeds with multiple targets.</P>

Molecular force fields with gradient-domain machine learning: Construction and application to dynamics of small molecules with coupled cluster forces

Sauceda, Huziel E.,Chmiela, Stefan,Poltavsky, Igor,Mü,ller, Klaus-Robert,Tkatchenko, Alexandre American Institute of Physics 2019 The Journal of chemical physics Vol.150 No.11

Intrinsic momentum generation by a combined neoclassical and turbulence mechanism in diverted DIII-D plasma edge

Seo, Janghoon,Chang, C. S.,Ku, S.,Kwon, J. M.,Choe, W.,Mü,ller, Stefan H. American Institute of Physics 2014 Physics of plasmas Vol.21 No.9

<P>Fluid Reynolds stress from turbulence has usually been considered to be responsible for the anomalous toroidal momentum transport in tokamak plasma. Experiment by Muller et al. [Phys. Rev. Lett. 106, 115001 (2011)], however, reported that neither the observed edge rotation profile nor the inward momentum transport phenomenon at the edge region of an H-mode plasma could be explained by the fluid Reynolds stress measured with reciprocating Langmuir-probe. The full-function gyrokinetic code XGC1 is used to explain, for the first time, Muller et al.'s experimental observations. It is discovered that, unlike in the plasma core, the fluid Reynolds stress from turbulence is not sufficient for momentum transport physics in plasma edge. The 'turbulent neoclassical' physics arising from the interaction between kinetic neoclassical orbit dynamics and plasma turbulence is key in the tokamak edge region across the plasma pedestal into core. (C) 2014 AIP Publishing LLC.</P>