288 results match your criteria: "Kirchhoff-Institute for Physics & BioQuant Center University of Heidelberg[Affiliation]"
Elife
December 2024
Department of Physiology, University of Bern, Bern, Switzerland.
One of the most fundamental laws of physics is the principle of least action. Motivated by its predictive power, we introduce a neuronal least-action principle for cortical processing of sensory streams to produce appropriate behavioral outputs in real time. The principle postulates that the voltage dynamics of cortical pyramidal neurons prospectively minimizes the local somato-dendritic mismatch error within individual neurons.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
Kirchhoff-Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.
In radiation tumor therapy, irradiation, on one hand, should cause cell death to the tumor. On the other hand, the surrounding non-tumor tissue should be maintained unaffected. Therefore, methods of local dose enhancements are highly interesting.
View Article and Find Full Text PDFOpen Res Eur
November 2024
Department for Neuro- and Sensory Physiology, University Medical Center Göttingen, Göttingen, 37077, Germany.
Background: Finding appropriate model parameters for multi-compartmental neuron models can be challenging. Parameters such as the leak and axial conductance are not always directly derivable from neuron observations but are crucial for replicating desired observations. The objective of this study is to replicate the attenuation behavior of an excitatory postsynaptic potential (EPSP) traveling along a linear chain of compartments on the analog BrainScaleS-2 neuromorphic hardware platform.
View Article and Find Full Text PDFFunction (Oxf)
December 2024
Heidelberg University, Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Heidelberg, Germany.
Peritoneal dialysis (PD) is an increasingly needed, life-maintaining kidney replacement therapy; efficient solute transport is critical for patient outcome. While the role of peritoneal perfusion on solute transport in PD has been described, the role of cellular barriers is uncertain, the mesothelium has been considered irrelevant. We calculated peritoneal blood microvascular endothelial (BESA) to mesothelial surface area (MSA) ratio in human peritonea in health, chronic kidney disease, and on PD, and performed molecular transport related gene profiling and single molecule localization microscopy in two mesothelial (MC) and two endothelial cell lines (EC).
View Article and Find Full Text PDFNanophotonics
May 2024
Department of Materials, University of Oxford, Oxford, UK.
Fast modulation of optical signals that carry multidimensional information in the form of wavelength, phase or polarization has fueled an explosion of interest in integrated photonics. This interest however masks a significant challenge which is that independent modulation of multi-wavelength carrier signals in a single waveguide is not trivial. Such challenge is attributed to the longitudinal direction of guided-mode propagation, limiting the spatial separation and modulation of electric-field.
View Article and Find Full Text PDFNat Commun
December 2024
Physical Institute, University of Münster, Münster, 48149, Germany.
Biological neural networks effortlessly tackle complex computational problems and excel at predicting outcomes from noisy, incomplete data. Artificial neural networks (ANNs), inspired by these biological counterparts, have emerged as powerful tools for deciphering intricate data patterns and making predictions. However, conventional ANNs can be viewed as "point estimates" that do not capture the uncertainty of prediction, which is an inherently probabilistic process.
View Article and Find Full Text PDFiScience
November 2024
Institute of Chemistry of Condensed Matter and Technologies for Energy, CNR ICMATE, Corso Stati Uniti 4, 35127, Padova, Italy.
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View Article and Find Full Text PDFACS Nano
November 2024
National Institute of Optics (CNR-INO), Via Nello Carrara 1, Sesto Fiorentino 50019, Italy.
Chem Sci
October 2024
Institute of Organic Chemistry, Heidelberg University Im Neuenheimer Feld 270 69120 Heidelberg Germany
Novel microporous polymers were synthesized through Yamamoto polymerization of selectively brominated spirofluorene-bridged -heterotriangulenes. Extensive characterization, including combustion analysis, ToF-SIMS, IR, and Raman spectroscopy, confirmed the elemental composition and integrity of the polymers. The amorphous polymers, observed by scanning electron microscopy as globular particles aggregating into larger structures, exhibited remarkable thermal stability (decomposition temperatures > 400 °C) and BET surface areas up to 690 m g.
View Article and Find Full Text PDFGenes (Basel)
September 2024
Kirchhoff-Institute for Physics, Heidelberg University, INF 227, 69117 Heidelberg, Germany.
Background: It is widely accepted that the 3D chromatin organization in human cell nuclei is not random and recent investigations point towards an interactive relation of epigenetic functioning and chromatin (re-)organization. Although chromatin organization seems to be the result of self-organization of the entirety of all molecules available in the cell nucleus, a general question remains open as to what extent chromatin organization might additionally be predetermined by the DNA sequence and, if so, if there are characteristic differences that distinguish typical regions involved in dysfunction-related aberrations from normal ones, since typical DNA breakpoint regions involved in disease-related chromosome aberrations are not randomly distributed along the DNA sequence.
Methods: Highly conserved -mer patterns in intronic and intergenic regions have been reported in eukaryotic genomes.
PLoS Comput Biol
August 2024
Max-Planck-Institute for Dynamics and Self-Organization, Göttingen, Germany.
A core challenge for the brain is to process information across various timescales. This could be achieved by a hierarchical organization of temporal processing through intrinsic mechanisms (e.g.
View Article and Find Full Text PDFNano Lett
September 2024
Kirchhoff-Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.
Nature
August 2024
Department of Materials, University of Oxford, Oxford, UK.
Advancements in optical coherence control have unlocked many cutting-edge applications, including long-haul communication, light detection and ranging (LiDAR) and optical coherence tomography. Prevailing wisdom suggests that using more coherent light sources leads to enhanced system performance and device functionalities. Our study introduces a photonic convolutional processing system that takes advantage of partially coherent light to boost computing parallelism without substantially sacrificing accuracy, potentially enabling larger-size photonic tensor cores.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2024
Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany.
Lithium-rich antiperovskites promise to be a compelling class of high-capacity cathode materials due to the existence of both cationic and anionic redox activity. Little is however known about the effect of separating the electrochemical cationic process from the anionic process and the associated implications on the electrochemical performance. In this context, we report the electrochemical properties of the illustrative example of three different (LiFe)SO materials with a focus on separating cationic from anionic effects.
View Article and Find Full Text PDFNanoscale
August 2024
Kirchhoff-Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.
Super-resolution microscopy has been used to show the formation of receptor clusters and adapted lipid organization of cell membranes for many members of the ErbB receptor family. The clustering behaviour depends on the receptor size and shape, possibly ligand binding or expression activity. Using single molecule localization microscopy (SMLM), we also showed this typical clustering for the epidermal growth factor receptor variant III (EGFRvIII) in glioblastoma multiforme (GBM) cells.
View Article and Find Full Text PDFChem Rev
July 2024
Institute of Physics, Carl von Ossietzky University, Carl-von-Ossietzky-Str. 9-11, 26129 Oldenburg, Germany.
This roadmap reviews the new, highly interdisciplinary research field studying the behavior of condensed matter systems exposed to radiation. The Review highlights several recent advances in the field and provides a roadmap for the development of the field over the next decade. Condensed matter systems exposed to radiation can be inorganic, organic, or biological, finite or infinite, composed of different molecular species or materials, exist in different phases, and operate under different thermodynamic conditions.
View Article and Find Full Text PDFJ Microsc
November 2024
Institute for Photonics and Robotics (IPR), Department of Applied Future Technologies, University of Applied Sciences of the Grisons (FH Graubünden), Chur, Switzerland.
The structure of the cell nucleus of higher organisms has become a major topic of advanced light microscopy. So far, a variety of methods have been applied, including confocal laser scanning fluorescence microscopy, 4Pi, STED and localisation microscopy approaches, as well as different types of patterned illumination microscopy, modulated either laterally (in the object plane) or axially (along the optical axis). Based on our experience, we discuss here some application perspectives of Modulated Illumination Microscopy (MIM) and its combination with single-molecule localisation microscopy (SMLM).
View Article and Find Full Text PDFFront Neurosci
March 2024
Kirchhoff-Institute for Physics, Heidelberg University, Heidelberg, Germany.
Genes (Basel)
December 2023
Kirchhoff Institute for Physics, Heidelberg University, INF 227, 69117 Heidelberg, Germany.
The specific characteristics of words (2 ≤ k ≤ 11) regarding genomic distribution and evolutionary conservation were recently found. Among them are, in high abundance, words with a tandem repeat structure (repeat unit length of 1 bp to 3 bp). Furthermore, there seems to be a class of extremely short tandem repeats (≤12 bp), so far overlooked, that are non-random-distributed and, therefore, may play a crucial role in the functioning of the genome.
View Article and Find Full Text PDFAdv Mater
February 2024
Institute of Physics, University of Münster, Heisenbergstr. 11, 48149, Münster, Germany.
Biomolecules
October 2023
Kirchhoff-Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, D-69120 Heidelberg, Germany.
Exposure to high acute doses of ionizing radiation (IR) can induce cutaneous radiation syndrome. Weeks after such radiation insults, keratinocyte nuclei of the epidermis exhibit persisting genomic lesions that present as focal accumulations of DNA double-strand break (DSB) damage marker proteins. Knowledge about the nanostructure of these genomic lesions is scarce.
View Article and Find Full Text PDFCurr Issues Mol Biol
October 2023
Kirchhoff-Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.
The spatial organization of euchromatin (EC) and heterochromatin (HC) appears as a cell-type specific network, which seems to have an impact on gene regulation and cell fate. The spatial organization of cohesin should thus also be characteristic for a cell type since it is involved in a TAD (topologically associating domain) formation, and thus in gene regulation or DNA repair processes. Based on the previous hypotheses and results on the general importance of heterochromatin organization on genome functions in particular, the configurations of these organizational units (EC represented by H3K4me3-positive regions, HC represented by H3K9me3-positive regions, cohesins) are investigated in the cell nuclei of different cancer and non-cancerous cell types and under different anti-cancer treatments.
View Article and Find Full Text PDFSci Adv
October 2023
Physical Institute, University of Münster, Heisenbergstraße 11, 48149 Münster, Germany.
We present an adaptive optical neural network based on a large-scale event-driven architecture. In addition to changing the synaptic weights (synaptic plasticity), the optical neural network's structure can also be reconfigured enabling various functionalities (structural plasticity). Key building blocks are wavelength-addressable artificial neurons with embedded phase-change materials that implement nonlinear activation functions and nonvolatile memory.
View Article and Find Full Text PDFEntropy (Basel)
August 2023
Image and Pattern Analysis Group, Institute for Mathematics, Heidelberg University, 69117 Heidelberg, Germany.
This paper introduces assignment flows for density matrices as state spaces for representation and analysis of data associated with vertices of an underlying weighted graph. Determining an assignment flow by geometric integration of the defining dynamical system causes an interaction of the non-commuting states across the graph, and the assignment of a pure (rank-one) state to each vertex after convergence. Adopting the Riemannian-Bogoliubov-Kubo-Mori metric from information geometry leads to closed-form local expressions that can be computed efficiently and implemented in a fine-grained parallel manner.
View Article and Find Full Text PDFJ Mater Chem C Mater
June 2023
Chair for Emerging Electronic Technologies, Technical University of Dresden Nöthnitzer Str. 61 01187 Dresden Germany
Exposure to environmental factors is generally expected to cause degradation in perovskite films and solar cells. Herein, we show that films with certain defect profiles can display the opposite effect, healing upon exposure to oxygen under illumination. We tune the iodine content of methylammonium lead triiodide perovskite from understoichiometric to overstoichiometric and expose them to oxygen and light prior to the addition of the top layers of the device, thereby examining the defect dependence of their photooxidative response in the absence of storage-related chemical processes.
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