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ttH + tH measurement withATLAS Full Run 2
No full textThe study of Higgs boson production in association with one or two top quarks provides a key window into the properties of the two heaviest fundamental particles in the Standard Model, and in particular into their couplings. This talk presents property measurement of Higgs boson, in particular cross section and CP nature, with tH and ttH production in pp collisions collected at 13 TeV with the ATLAS detector using the full Run 2 dataset of the LHC
Quality concerns caused by quality control — deformation of silicon strip detector modules in thermal cycling tests
No full textThe ATLAS experiment at the Large Hadron Collider (LHC) iscurrently preparing to replace its present Inner Detector (ID) withthe upgraded, all-silicon Inner Tracker (ITk) for itsHigh-Luminosity upgrade (HL-LHC). The ITk will consist of acentral pixel tracker and the outer strip tracker, consisting ofabout 19,000 strip detector modules. Each strip module is assembledfrom up to two sensors, and up to five flexes (depending on itsgeometry) in a series of gluing, wirebonding and quality controlsteps. During detector operation, modules will be cooled down totemperatures of about -35 C (corresponding to thetemperature of the support structures on which they will be mounted)after being initially assembled and stored at room temperature. Inorder to ensure compatibility with the detector's operatingtemperature range, modules are subjected to thermal cycling as partof their quality control process. Ten cycles between-35 C and +40 C are performed for eachmodule, with full electrical characterisation tests at each high andlow temperature point. As part of an investigation into the stressexperienced by modules during cooling, it was observed that modulesgenerally showed a change in module shape before and after thermalcycling. This paper presents a summary of the discovery andunderstanding of the observed changes, connecting them with excessmodule stress, as well as the resulting modifications to the modulethermal cycling procedure
Assessing scoring metrics for AlphaFold2 and AlphaFold3 protein complex predictions
No full textRecent breakthroughs in AI-driven protein structure prediction have revolutionized structural biology, unlocking new possibilities to model complex biomolecular interactions. We evaluated widely used scoring metrics for assessing models predicted by ColabFold with templates, ColabFold without templates, and AlphaFold3. We benchmarked the optimal cutoffs for these assessment scores using a set of 223 heterodimeric, high-resolution protein structures and their predictions. Our results show that ColabFold with templates and AlphaFold3 perform similarly, and both outperform ColabFold without templates. However, the assessment scores perform best on ColabFold without templates. Furthermore, interface-specific scores are more reliable for evaluating protein complex predictions compared to the corresponding global scores. Notably, ipTM and model confidence achieve the best discrimination between correct and incorrect predictions. Based on our results, we developed a weighted combined score, C2Qscore, to improve model quality assessment. We used C2Qscore to analyze dimers from large assemblies solved by cryoEM, revealing potential limitations of the existing metrics when multiple configurations of heterodimers are possible. This study provides insights into the strengths and weaknesses of current scores and offers guidance for improving protein complex model assessment under realistic use case conditions. C2Qscore has been integrated as a tool into our ChimeraX plug-in PICKLUSTER v.2.0 and is also available as a command-line tool on https://gitlab.com/topf-lab/c2qscore
Controlling Organic Semiconductor Self-Assembly through Cylindrical Nanoconfinement
No full textControlling the self-assembly of organic semiconductors at the nanoscale is critical for advancing high-performance electronic and photonic devices, yet remains challenging due to their intrinsic anisotropic crystallization and sensitivity to processing conditions. Here, we demonstrate that cylindrical nanoconfinement within anodic aluminum oxide membranes provides a versatile platform to precisely tune the molecular orientation and phase behavior of the prototypical organic semiconductor 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT-C8). Combining temperature-dependent high-resolution synchrotron X-ray scattering with optical birefringence measurements, we uncover that confinement geometries (pore diameters 25–180 nm) and surface chemistry govern the emergence of distinct smectic A textures, featuring molecular layers either parallel or perpendicular to the pore axis. The competition between axial and radial smectic layering is modulated by pore size, surface hydrophilicity, and thermal history, enabling reversible control over domain orientations and transitions between liquid crystalline and crystalline states. Notably, nanoconfinement stabilizes the smectic phase over an expanded temperature range compared to bulk, while inducing complex multi-domain configurations owing to geometric constraints and anchoring conditions. Our results elucidate fundamental mechanisms by which anisotropic nanoscale confinement directs the self-organization of highly conjugated organic molecules, with implications for optimizing directional charge transport and anisotropic optical responses in organic–inorganic hybrid nanoarchitectures. This study establishes nanoconfinement as a powerful strategy to engineer morphology and functional properties in organic semiconducting materials with nanoscale precision
Improved measurements of the TeV--PeV extragalactic neutrino spectrum from joint analyses of IceCube tracks and cascades
No full textThe IceCube South Pole Neutrino Observatory has discovered the presence of a diffuse astrophysical neutrino flux at energies of TeV and beyond using neutrino induced muon tracks and cascade events from neutrino interactions. We present two analyses sensitive to neutrino events in the energy range \SI1{TeV} to \SI{10}{PeV}, using more than 10 years of IceCube data. Both analyses consistently reject a neutrino spectrum following a single power-law with significance in favor of a broken power law. We describe the methods implemented in the two analyses, the spectral constraints obtained, and the validation of the robustness of the results. Additionally, we report the detection of a muon neutrino in the MESE sample with an energy of \si{PeV}, the highest energy neutrino observed by IceCube to date. The results presented here show insights into the spectral shape of astrophysical neutrinos, which has important implications for inferring their production processes in a multi-messenger picture
Trade-Offs between Stability and Activity of Glycosylated and Non-Glycosylated Polyester Hydrolases PHL7 and PHL7mut3
No full textPlastic pollution has become a global environmental challenge, driving interest in enzymatic polyethylene terephthalate (PET) recycling by using polyester hydrolases. In this study, we produced the PET-degrading enzyme PHL7 and its variant PHL7mut3 in Escherichia coli and Pichia pastoris (syn. Komagataella phaffii) to investigate the impact of N-glycosylation on enzyme properties. While glycosylation upon expression in P. pastoris enhanced thermal stability, it reduced the catalytic activity of the enzymes, revealing a trade-off that adds complexity to the selection of the best-suited expression system. Additionally, we engineered P. pastoris to produce non-glycosylated enzyme variants by substituting the asparagine residues (N) at all three putative N-glycosylation sites with glutamine residues (Q). The non-glycosylated P. pastoris-produced enzymes showed a lower activity compared to those produced in E. coli, likely due to the differences in the amino acid sequence. The effects of glycosylation were less pronounced in PHL7mut3 than in PHL7, yet N-glycosylation strongly influenced the performance of both enzymes. We further demonstrate that the PET degradation performance of PHL7mut3 is less dependent on the buffer ionic strength than that of PHL7. The study emphasizes the need for the informed selection of a suitable expression host for polyester hydrolases to balance enzyme activity, thermostability, and production titer for applications in PET recycling
Search for dark matter produced in association with one or two top quarks in proton-proton collisions at = 13 TeV
No full textA search is performed for dark matter (DM) produced in association with a single top quark or a pair of top quarks using the data collected with the CMS detector at the LHC from proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to 138 fb of integrated luminosity. An excess of events with a large imbalance of transverse momentum is searched for across 0, 1 and 2 lepton final states. Novel multivariate techniques are used to take advantage of the differences in kinematic properties between the two DM production mechanisms. No significant deviations with respect to the standard model predictions are observed. The results are interpreted considering a simplified model in which the mediator is either a scalar or pseudoscalar particle and couples to top quarks and to DM fermions. Axion-like particles that are coupled to top quarks and DM fermions are also considered. Expected exclusion limits of 410 and 380 GeV for scalar and pseudoscalar mediator masses, respectively, are set at the 95% confidence level. A DM particle mass of 1 GeV is assumed, with mediator couplings to fermions and DM particles set to unity. A small signal-like excess is observed in data, with the largest local significance observed to be 1.9 standard deviations for the 150 GeV pseudoscalar mediator hypothesis. Because of this excess, mediator masses are only excluded below 310 (320) GeV for the scalar (pseudoscalar) mediator. The results are also translated into model-independent 95% confidence level upper limits on the visible cross section of DM production in association with top quarks, ranging from 1 pb to 0.02 pb.[graphic not available: see fulltext
The changing look of the neutrino-emitter blazar candidate 5BZQ J1243+4043
No full textContext. In recent years, changing-look blazars have called the traditional view of BL Lacs-flat spectrum radio quasars into question within the empirical classification of blazars. Based on the intensity of the optical spectral lines, they appear to transition between the two classes over time.Aims. We focus on the blazar 5BZQ J1243+4043, recently proposed as a promising candidate for the emission of high-energy neutrinos observed by the IceCube Neutrino Observatory and reported as a changing-look blazar in the literature. We study the spectral properties of this blazar, inferring its radiation field and accretion regime properties across different epochs.Methods. This study presents new optical spectroscopy observations of 5BZQ J1243+4043 taken with the Gran Telescopio Canarias. We used this new dataset and two optical spectra available from the literature to investigate the continuum and line emissions and pinpoint the physical properties of the source. In particular, we used the emission lines to probe the accretion regime.Results. The newly collected data for 5BZQ J1243+4043 shows broad emission lines, consistent with the spectrum of the first epoch and the redshift z = 1.5181 ± 0.0002 known from the literature. For the second epoch, the spectrum appears featureless and so, we placed limits on the emission lines and related physical properties. We observed spectral variability for both the continuum and line emissions among the three spectra. Nonetheless, the accretion properties of the blazar generally remain unvaried, indicating that the intrinsic physics stays the same across the three epochs. In the broader multi-messenger context, this suggests that, despite the changing look in the optical band, the candidate neutrino-emitter blazar 5BZQ J1243+4043 is still characterized by the presence of intense external radiation fields and radiatively efficient accretion, typical of high-excitation radio galaxies, which may foster neutrino production
Baryons as linked vortices in QCD matter with isospin asymmetry
No full textWe investigate a baryonic structure in low-energy QCD via a model-independent way using the chiral perturbation theory at the leading order, in the presence of the baryon chemical potential , the isospin chemical potential , and the electromagnetic coupling. For such a scenario in the chiral limit, it has been known that the neutral pion winds like in the chiral soliton lattice, confined within an Abrikosov-Nielsen-Olesen (ANO) vortex of the charged pions. This structure undergoes a drastic transformation when the pion mass is introduced, i.e., both charged and neutral pions condense in the bulk, allowing two distinct types of vortices: the charged pions constitute a local ANO-like vortex, while the neutral pion configures a global vortex which is further attached to a domain wall also known as the chiral soliton. Remarkably, the ANO vortex forms a topological linking with the closed global vortex line, when exceeds its critical value as a function of . The linking number has the physical meaning of the baryon number in view of the Wess-Zumino-Witten term. In this sense, the linked configuration realizes a stable Skyrmion-type solution, but innovatively without the Skyrme term. We therefore propose a novel phase of dense baryonic matter comprised of such vortices, which shall play a role in the low-energy QCD phase diagram
Design, development and evaluation of a tritium-labeled radiotracer for ecto-5’-nucleotidase (CD73) – A versatile research tool and diagnostic agent for personalized medicine
No full textEcto-5’-nucleotidase (CD73) is the main enzyme that catalyzes the hydrolysis of extracellular AMP to produce anti-inflammatory, immunosuppressive adenosine. Many tumor cells over-express ectonucleotidases accumulating adenosine in the tumor microenvironment, which promotes tumor growth, metastasis, angiogenesis, and immune escape. CD73 is upregulated in inflammation, and possesses potential as a biomarker and as a novel drug target for inflammatory diseases and cancer immunotherapy. New, metabolically stable N6-disubstituted adenosine-5’-diphosphate analogs were synthesized providing a basis for the design and preparation of the CD73-selective radioligand [3H]PSB-17230 by catalytic hydrogenation of a propargyl-substituted precursor. It showed high, pico- to low nanomolar affinity for human, rat and mouse CD73, slow dissociation kinetics, negligible non-specific binding, and high selectivity, as confirmed by studies on an inactive CD73 mutant and CD73 knockout cells. A high-resolution co-crystal structure (2.35 Å) of PSB-17230 with human CD73 elucidated its binding interactions. Radioligand binding was employed to characterize competitive CD73 inhibitors and to study expression levels of the enzyme in tissues and tumor cell lines of different species. Moreover, [3H]PSB-17230 was employed in autoradiography studies to determine CD73 expression in healthy and diseased mouse and human tissues. Significant upregulation of CD73 was observed in a mouse asthma model and in kidney cancer biopsies as compared to healthy controls. [3H]PSB-17230 represents a high-affinity tracer which is anticipated to find broad application in drug screening, preclinical studies, and for diagnostic purposes in inflammation and cancer, enabling drug monitoring and targeted therapies