Cui Li, Bo Liu, David Vonlanthen, Marcel Mayor, Yongchun Fu, Jianfeng Li, Thomas Wandlowski,
In situ gap-mode Raman spectra were acquired in an electrochemical environment on a single-crystal gold electrode employing a Au(100)|4,4'-biphenyldithiol (BPDT)|Au-NP(55 nm) sandwich assembly. This geometry enabled an investigation of the influence of an applied electrochemical gate field on the conformational changes in nanojunctions, such as the torsion angle (φ) of molecules. A linear correlation between the intensity ratio I(C═C)/I(C(ring)-S) and cos(2) φ in 4,4'-BPDT-type molecular junctions ...
Tópico(s): Gold and Silver Nanoparticles Synthesis and Applications
2011 - American Chemical Society | Journal of the American Chemical Society
B. Habibi, M. Lopez, M Serdaru, A Baumelou, Marcel Vonlanthen, R Marteau, Charles T. Salmon,
TENIPOSIDE (VM 26) is a semisynthetic derivative of podophyllotoxin (molecular weight, 657 daltons) that has been used for a decade in cancer chemotherapy, especially in lymphoma and brain tumors. The drug has been reported to cause anaphylactic reactions of unknown origin.1 This paper describes clinical and immunohematologic features of an antibody to teniposide that causes acute hemolysis and renal failure.Case HistoryTeniposide therapy was initiated in a 47-year-old man who had a relapse a few ...
Tópico(s): Blood disorders and treatments
1982 - Massachusetts Medical Society | New England Journal of Medicine
Jacques Rottembourg, D Jacq, Marcel Vonlanthen, Belkacem Issad Yassin El Shahat,
Tópico(s): Central Venous Catheters and Hemodialysis
1980 - SAGE Publishing | Peritoneal Dialysis International
Dimitris Perdios, Manuel Vonlanthen, Florian Martinez, Marcel Arditi, Jean‐Philippe Thiran,
Ultrafast ultrasound (US) revolutionized biomedical imaging with its capability of acquiring full-view frames at over 1 kHz, unlocking breakthrough modalities such as shear-wave elastography and functional US neuroimaging. Yet, it suffers from strong diffraction artifacts, mainly caused by grating lobes, sidelobes, or edge waves. Multiple acquisitions are typically required to obtain a sufficient image quality, at the cost of a reduced frame rate. To answer the increasing demand for high-quality ...
Tópico(s): Flow Measurement and Analysis
2021 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control
Jürgen Rotzler, Heiko Gsellinger, Markus Neuburger, David Vonlanthen, Daniel Häußinger, Marcel Mayor,
The thermodynamics of the atropisomerisation of torsion angle restricted, axial chiral biphenyl-based push-pull cyclophanes were studied. Using 1H NMR coalescence measurements the rotation barrier around the central C–C bond was determined to be 50 kJ mol−1 for the propyl-bridged biphenyl derivative 1b, displaying only a negligible solvent dependence. By protonation of the piperidinyl nitrogen as electron donor, the free energy ΔG‡(T) of the rotation barrier increased, indicating that the tendency ...
Tópico(s): Molecular spectroscopy and chirality
2010 - Royal Society of Chemistry | Organic & Biomolecular Chemistry
Marcel Vonlanthen, Jonas Allegrini, Jan Carmeliet,
A nested Large Eddy Simulation (LES) is used to compute the multiscale interaction between the Atmospheric Boundary Layer (ABL) and an existing cluster of buildings over the real topography. A Neutral ABL (NBL) and a Convective ABL (CBL) are simulated. As the ABLs develop over a no-flat terrain with heterogeneous roughness elements, standard ABL-LES with cyclic boundary condition cannot be used. Instead, a synthetic inflow generator is used to generate realistic turbulent NBL and CBL over the real terrain. ...
Tópico(s): Meteorological Phenomena and Simulations
2017 - Elsevier BV | Urban Climate
Jürgen Rotzler, Heiko Gsellinger, Angela Bihlmeier, Markus Gantenbein, David Vonlanthen, Daniel Häußinger, Wim Klopper, Marcel Mayor,
The influence of electron donors and electron acceptors of variable strength in the 4 and 4' position of 2 and 2' propyl-bridged axial chiral biphenyl cyclophanes on their atropisomerization process was studied. Estimated free energies ΔG(‡)(T) of the rotation around the central biphenyl bond which were obtained from (1)H-NMR coalescence measurements were correlated to the Hammett parameters σ(p) as a measure for electron donor and acceptor strength. It is demonstrated that the resulting nice linear ...
Tópico(s): Synthesis and Properties of Aromatic Compounds
2012 - Royal Society of Chemistry | Organic & Biomolecular Chemistry
Marius Bürkle, Linda A. Zotti, J. K. Viljas, David Vonlanthen, Artem Mishchenko, Th. Wandlowski, Marcel Mayor, Gerd Schön, Fabian Pauly,
By employing $ab$ initio electronic-structure calculations combined with the nonequilibrium Green's function technique, we study the dependence of the thermopower $Q$ on the conformation in biphenyl-based single-molecule junctions. For the series of experimentally available biphenyl molecules, alkyl side chains allow us to gradually adjust the torsion angle $\ensuremath{\phi}$ between the two phenyl rings from ${0}^{\ensuremath{\circ}}$ to ${90}^{\ensuremath{\circ}}$ and to control in this way the degree ...
Tópico(s): Surface and Thin Film Phenomena
2012 - American Physical Society | Physical Review B
Marius Bürkle, J. K. Viljas, David Vonlanthen, Artem Mishchenko, Gerd Schön, Marcel Mayor, Thomas Wandlowski, Fabian Pauly,
Based on density-functional theory calculations, we report a detailed study of the single-molecule charge-transport properties for a series of recently synthesized biphenyl-dithiol molecules [D. Vonlanthen et al., Angew. Chem., Int. Ed. 48, 8886 (2009); A. Mishchenko et al., Nano Lett. 10, 156 (2010)]. The torsion angle {\phi} between the two phenyl rings, and hence the degree of {\pi} conjugation, is controlled by alkyl chains and methyl side groups. We consider three different coordination geometries, ...
Tópico(s): Organic Electronics and Photovoltaics
2012 - American Physical Society | Physical Review B
David Vonlanthen, Jürgen Rotzler, Markus Neuburger, Marcel Mayor,
Abstract A series of modular biphenyl building blocks with stepwise adjusted torsion angles and terminally functionalized with leaving groups have been synthesized. The two phenyl rings of the biphenyl synthon are clamped by alkyl chains of various lengths. The desired building blocks 3 and 4 were obtained by copper‐mediated C–C biaryl coupling reactions followed by the construction of interlinking alkyl bridges. The key intermediates 14 and 15 were transformed into the corresponding cycloheptadienones ...
Tópico(s): Axial and Atropisomeric Chirality Synthesis
2009 - Wiley | European Journal of Organic Chemistry
Dimitris Perdios, Manuel Vonlanthen, Florian Martinez, Marcel Arditi, Jean‐Philippe Thiran,
Thanks to its capability of acquiring full-view frames at multiple kilohertz, ultrafast ultrasound imaging unlocked the analysis of rapidly changing physical phenomena in the human body, with pioneering applications such as ultrasensitive flow imaging in the cardiovascular system or shear-wave elastography. The accuracy achievable with these motion estimation techniques is strongly contingent upon two contradictory requirements: a high quality of consecutive frames and a high frame rate. Indeed, ...
Tópico(s): Advanced MRI Techniques and Applications
2020 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Medical Imaging
Jürgen Rotzler, David Vonlanthen, Alberto Barsella, Alex Boeglin, Alain Fort, Marcel Mayor,
Abstract Terminal piperidinyl‐ and nitro‐functionalized biphenyls, bridged between the 2 and 2′ positions by a variable number of methylene groups, are synthesized and fully characterized. These push‐pull systems with defined and restricted torsion angles between their phenyl rings are ideal model compounds to investigate the influence of the chromophore's conjugation in nonlinear optic (NLO) responses. A general synthetic route that can be implemented to access these model compounds is reported, ...
Tópico(s): Photochemistry and Electron Transfer Studies
2010 - Wiley | European Journal of Organic Chemistry
Marcel Vonlanthen, Jonas Allegrini, Jan Carmeliet,
Large Eddy Simulation (LES) of obstacle-resolved flow over extended urban areas is still extremely costly, compared to the common practice of modeling obstacles with a rough wall-function. In the current study we investigate whether a one-way nesting procedure, consisting of a highly-resolved, small-scale LES embedded inside a low-resolution, large-scale LES, can provide a good compromise between spatial extent, accuracy, and computational requirements. The nesting is achieved by blending the fields ...
Tópico(s): Combustion and flame dynamics
2016 - Elsevier BV | Computers & Fluids
Artem Mishchenko, Linda A. Zotti, David Vonlanthen, Marius Bürkle, Fabian Pauly, Juan Carlos Cuevas, Marcel Mayor, Thomas Wandlowski,
We present a combined experimental and theoretical study of the electronic transport through single-molecule junctions based on nitrile-terminated biphenyl derivatives. Using a scanning tunneling microscope-based break-junction technique, we show that the nitrile-terminated compounds give rise to well-defined peaks in the conductance histograms resulting from the high selectivity of the N−Au binding. Ab initio calculations have revealed that the transport takes place through the tail of the LUMO. ...
Tópico(s): Force Microscopy Techniques and Applications
2010 - American Chemical Society | Journal of the American Chemical Society
David Vonlanthen, Artem Mishchenko, Mark Elbing, Markus Neuburger, Thomas Wandlowski, Marcel Mayor,
Stepwise regulation of the molecular conductance was observed in a series of eight biphenyldithiols with fixed torsion angles between the phenyl rings. These compounds were synthesized and their single-molecule conductance was investigated in an STM junction. A cos2 dependence was found between the interplane torsion angle and the single-molecule conductivity (see plot).
Tópico(s): Organic Electronics and Photovoltaics
2009 - Wiley | Angewandte Chemie International Edition
David Vonlanthen, Artem Mishchenko, Mark Elbing, Markus Neuburger, Thomas Wandlowski, Marcel Mayor,
Stufenweise einstellbar ist die Leitfähigkeit in einer Reihe aus acht Biphenyldithiolen mit festgelegten Torsionswinkeln zwischen den Arenebenen, die synthetisiert und in einem STM-Einzelmolekülbruchkontakt untersucht wurden. Dabei ergab sich eine cos2-Abhängigkeit zwischen dem Torsionswinkel und der Leitfähigkeit der einzelnen Moleküle (siehe Diagramm).
Tópico(s): Force Microscopy Techniques and Applications
2009 - Wiley | Angewandte Chemie
David Vonlanthen, Alexander V. Rudnev, Artem Mishchenko, A. Kaslin, Jürgen Rotzler, Markus Neuburger, Thomas Wandlowski, Marcel Mayor,
Abstract A series of dicyanobiphenylcyclophanes 1 – 6 with various π‐backbone conformations and characteristic n‐type semiconductor properties is presented. Their synthesis, optical, structural, electrochemical, spectroelectrochemical, and packing properties are investigated. The X‐ray crystal structures of all n‐type rods allow the systematic correlation of structural features with physical properties. In addition, the results are supported by quantum mechanical calculations based on density functional ...
Tópico(s): Conducting polymers and applications
2011 - Wiley | Chemistry - A European Journal
Artem Mishchenko, David Vonlanthen, Velimir Meded, Marius Bürkle, Chen Li, Ilya V. Pobelov, A. Bagrets, J. K. Viljas, Fabian Pauly, Ferdinand Evers, Marcel Mayor, Thomas Wandlowski,
The conductance of a family of biphenyl-dithiol derivatives with conformationally fixed torsion angle was measured using the scanning tunneling microscopy (STM)-break-junction method. We found that it depends on the torsion angle φ between two phenyl rings; twisting the biphenyl system from flat (φ = 0°) to perpendicular (φ = 90°) decreased the conductance by a factor of 30. Detailed calculations of transport based on density functional theory and a two level model (TLM) support the experimentally obtained ...
Tópico(s): Quantum and electron transport phenomena
2009 - American Chemical Society | Nano Letters
Dániel Gerö, Marcel Schneider, Michel Suter, Ralph Peterli, René Vonlanthen, Matthias Turina, Marco Bueter,
Background Sleeve gastrectomy (SG) recently became the most frequently performed bariatric surgery (BS) worldwide, overtaking the long-time standard Roux-en-Y gastric bypass (RYGB). Main indications for one or the other procedure show large inter-center variations and warrant further investigations. Objectives The aim of this study was to identify the influencers of primary BS selection in Switzerland. Setting Switzerland. Methods Retrospective analysis of all hospitalizations in Switzerland January ...
Tópico(s): Esophageal and GI Pathology
2020 - Elsevier BV | Surgery for Obesity and Related Diseases
Martina Goeldlin, Jan Vynckier, Madlaine Mueller, Boudewijn R.H. Drop, Basel Maamari, Noah Vonlanthen, Bernhard Siepen, Arsany Hakim, Johannes Kaesmacher, Christopher Marvin Jesse, Mandy D Mueller, Thomas R. Meinel, Morin Beyeler, Leander Clénin, Jan Gralla, Werner J. Z’Graggen, David Bervini, Marcel Arnold, Urs Fischer, David Seiffge,
Deep perforator arteriolopathy (DPA) causes intracerebral haemorrhage (ICH) and lacunar strokes (LS). We compare patient characteristics, MRI findings and clinical outcomes among patients with deep ICH and LS.We included patients with MRI-confirmed LS or ICH in the basal ganglia, thalamus, internal capsule or brainstem from the Bernese Stroke Registry. We assessed MRI small vessel disease (SVD) markers, SVD burden score, modified Rankin Scale (mRS) and ischaemic stroke or ICH at 3 months.We included ...
Tópico(s): Cerebrovascular and Carotid Artery Diseases
2023 - SAGE Publishing | European Stroke Journal