Publications by authors named "Held K"

Waterfalls are anomalies in the angle-resolved photoemission spectrum where the energy-momentum dispersion is almost vertical, and the spectrum strongly smeared out. These anomalies are observed at relatively high energies, among others, in superconducting cuprates and nickelates. The prevalent understanding is that they originate from the coupling to some boson, with spin fluctuations and phonons being the usual suspects.

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Introduction: The Collapsible Aerosolized Particle Enclosure (CAPE) is a negative pressure patient isolation device designed to protect patients and clinicians from aerosolized infectious particles. The CAPE is intended to provide a safe environment for care receipt and delivery when isolation capacity is limited. The goal of this study was to evaluate the acceptability of receiving care in the CAPE from the emergency department (ED) patient perspective.

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There is an unmet need for effectively treating dry eye disease (DED), a T cell-mediated chronic, inflammatory ocular surface disorder. Given the potential of nonneuronal adrenergic system in modulating T cell response, we herein investigated the therapeutic efficacy and the underlying mechanisms of a specific alpha 2 adrenergic receptor agonist (AGN-762, selective for α2B/2C receptor subtypes) in a mouse model of DED. Experimental DED was treated with the AGN-762 by oral gavage, either at disease induction or after disease establishment, and showed sustained amelioration, along with reduced expression of DED-pathogenic cytokines in ocular surface tissues, decreased corneal MHC-IICD11b cells and lymphoid Th17 cells, and higher function of regulatory T cells (Treg).

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We present an analytically solvable model for correlated electrons, which is able to capture the major Fermi surface modifications occurring in both hole- and electron-doped cuprates as a function of doping. The proposed Hamiltonian qualitatively reproduces the results of numerically demanding many-body calculations, here obtained using the dynamical vertex approximation. Our analytical theory provides a transparent description of a precise mechanism, capable of driving the formation of disconnected segments along the Fermi surface (the highly debated "Fermi arcs"), as well as the opening of a pseudogap in hole and electron doping.

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Article Synopsis
  • The Million Person Study (MPS) investigates the health impacts of gradual exposure to ionizing radiation on over one million U.S. radiation workers and veterans, focusing on both cancer and non-cancer conditions.
  • Recent efforts have highlighted mortality patterns related to neurological and behavioral disorders, such as Parkinson's and Alzheimer's diseases, by analyzing claims data from Medicare beneficiaries.
  • To manage the extensive and complex dataset, the MPS is developing specialized open-source software (Colossus) to facilitate detailed evaluation of health outcomes and related factors from the collected health information.
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Background: As a result of shared social and structural risk factors, people in households affected by tuberculosis may have an increased risk of chronic conditions; at the same time, tuberculosis screening may be an opportunity for interventions. We sought to describe the prevalence of HIV, nutritional disorders, and noncommunicable diseases (NCDs) among members of tuberculosis-affected households in 3 African countries.

Methods And Findings: A part of a multicountry cohort study, we screened for tuberculosis, HIV, nutritional disorders (underweight, anaemia, overweight/obesity), and NCDs (diabetes, hypertension, and chronic lung disease) among members of tuberculosis-affected households aged ≥10 years in Mozambique, Tanzania, and Zimbabwe.

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Purpose: Epidemiological studies of stochastic radiation health effects such as cancer, meant to estimate risks of the adverse effects as a function of radiation dose, depend largely on estimates of the radiation doses received by the exposed group under study. Those estimates are based on dosimetry that always has uncertainty, which often can be quite substantial. Studies that do not incorporate statistical methods to correct for dosimetric uncertainty may produce biased estimates of risk and incorrect confidence bounds on those estimates.

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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron breakthrough infection (BTI) induced better protection than triple vaccination. To address the underlying immunological mechanisms, we studied antibody and T cell response dynamics during vaccination and after BTI. Each vaccination significantly increased peak neutralization titers with simultaneous increases in circulating spike-specific T cell frequencies.

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Numerous dose rate effects have been described over the past 6-7 decades in the radiation biology and radiation oncology literature depending on the dose rate range being discussed. This review focuses on the impact and understanding of altering dose rates in the context of radiation therapy, but does not discuss dose rate effects as relevant to radiation protection. The review starts with a short historic review of early studies on dose rate effects, considers mechanisms thought to underlie dose rate dependencies, then discusses some current issues in clinical findings with altered dose rates, the importance of dose rate in brachytherapy, and the current timely topic of the use of very high dose rates, so-called FLASH radiotherapy.

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Correlated electron systems may give rise to multiple effective interactions whose combined impact on quasiparticle properties can be difficult to disentangle. We introduce an unambiguous decomposition of the electronic self-energy which allows us to quantify the contributions of various effective interactions simultaneously. We use this tool to revisit the hole-doped Hubbard model within the dynamical cluster approximation, where commonly spin fluctuations are considered to be the origin of the pseudogap.

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Article Synopsis
  • High-temperature superconductivity often develops from doped antiferromagnetic insulators, with nickelates being a key focus in this research.
  • The dynamical vertex approximation technique has successfully predicted the superconducting properties of nickelates, specifically the SrPrNiO under pressure.
  • Experimental results indicate that increasing pressure enhances the critical temperature (T), potentially reaching up to 100 K at around 100 GPa, rivaling the best cuprate superconductors.
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Purpose: Radiation-induced bystander effect (RIBE) frequently is seen as DNA damage in unirradiated bystander cells, but the repair processes initiated in response to that DNA damage are not well understood. RIBE-mediated formation of micronuclei (MN), a biomarker of persistent DNA damage, was previously observed in bystander normal fibroblast (AG01522) cells, but not in bystander human chondrosarcoma (HTB94) cells. The molecular mechanisms causing this disparity are not clear.

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  • The research on the potential superconductor PbCu(PO)O, or LK-99, is reviewed, focusing on its current status and characteristics.
  • Tight-binding parameters are derived for both two-band and five-band models and analyzed using dynamical-mean-field theory.
  • LK-99 behaves as a Mott or charge transfer insulator due to the interaction-to-bandwidth ratio, and requires electron or hole doping to become metallic and possibly superconducting.
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The mycobacteriological analysis of sputum samples is the gold standard for tuberculosis diagnosis and treatment monitoring. However, sputum production can be challenging after the initiation of TB treatment. As a possible alternative, we therefore investigated the dynamics of neutrophil-derived soluble inflammatory mediators during TB treatment in relation to HIV ART status and the severity of lung impairment.

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Despite intensive research since the emergence of SARS-CoV-2, it has remained unclear precisely which components of the early immune response protect against the development of severe COVID-19. Here, we perform a comprehensive immunogenetic and virologic analysis of nasopharyngeal and peripheral blood samples obtained during the acute phase of infection with SARS-CoV-2. We find that soluble and transcriptional markers of systemic inflammation peak during the first week after symptom onset and correlate directly with upper airways viral loads (UA-VLs), whereas the contemporaneous frequencies of circulating viral nucleocapsid (NC)-specific CD4 and CD8 T cells correlate inversely with various inflammatory markers and UA-VLs.

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The plague bacterium, Yersinia pestis, forms a biofilm-mediated blockage in the flea foregut that enhances its transmission by fleabite. Biofilm formation is positively controlled by cyclic di-GMP (c-di-GMP), which is synthesized by the diguanylate cyclases (DGC), HmsD and HmsT. While HmsD primarily promotes biofilm-mediated blockage of fleas, HmsT plays a more minor role in this process.

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The one-dimensional confinement of quasiparticles in individual carbon nanotubes (CNTs) leads to extremely anisotropic electronic and optical properties. In a macroscopic ensemble of randomly oriented CNTs, this anisotropy disappears together with other properties that make them attractive for certain device applications. The question however remains if not only anisotropy but also other types of behaviors are suppressed by disorder.

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Motivated by cuprate and nickelate superconductors, we perform a comprehensive study of the superconducting instability in the single-band Hubbard model. We calculate the spectrum and superconducting transition temperature T_{c} as a function of filling and Coulomb interaction for a range of hopping parameters, using the dynamical vertex approximation. We find the sweet spot for high T_{c} to be at intermediate coupling, moderate Fermi surface warping, and low hole doping.

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Human papilloma virus (HPV) infections are associated with almost all cervical cancers and to a lower extend also with anogenital or oropharyngeal cancers. HPV proteins expressed in HPV-associated tumors are attractive antigens for cancer vaccination strategies as self-tolerance, which is associated with most endogenous tumor-associated antigens, does not need to be overcome. In this study, we generated a live attenuated cancer vaccine based on the chimeric vesicular stomatitis virus VSV-GP, which has previously proven to be a potent vaccine vector and oncolytic virus.

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Background: Early embryo implantation is a complex phenomenon characterized by the presence of an implantation-competent blastocyst and a receptive endometrium. Embryo development and endometrial receptivity must be synchronized and an adequate two-way dialogue between them is necessary for maternal recognition and implantation. Proteases have been described as blastocyst-secreted proteins involved in the hatching process and early implantation events.

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Article Synopsis
  • Immunogens and vaccination strategies can shape how the immune system recognizes virus weak points, like HIV-1's envelope.
  • In HIV vaccine trials, responses to specific parts of the envelope were observed to vary; V2 responses were unique to certain regimens, while V3 responses were widespread.
  • Strong V3-specific antibody production was linked to a better overall immune response and did not hinder the recognition of other important viral sites, indicating that targeting multiple regions of vulnerability may be beneficial.
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TRPM3 is a temperature- and neurosteroid-sensitive plasma membrane cation channel expressed in a variety of neuronal and non-neuronal cells. Recently, rare de novo variants in were identified in individuals with developmental and epileptic encephalopathy, but the link between TRPM3 activity and neuronal disease remains poorly understood. We previously reported that two disease-associated variants in TRPM3 lead to a gain of channel function .

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Fatigue is a common adverse effect of external beam radiation therapy in cancer patients. Mechanisms causing radiation fatigue remain unclear, although linkage to skin irradiation has been suggested. β-Endorphin, an endogenous opioid, is synthesized in skin following genotoxic ultraviolet irradiation and acts systemically, producing addiction.

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Introduction: The WHO End-TB Strategy calls for the development of novel diagnostics to detect tuberculosis (TB) earlier and more accurately. Better diagnostics, together with tools to predict disease progression, are critical for achieving WHO End-TB targets. The arly isk ssessment in TB Contacts by new diagnotic tsts (ERASE-TB) study aims to evaluate novel diagnostics and testing algorithms for early TB diagnosis and accurate prediction of disease progression among household contacts (HHCs) exposed to confirmed index cases in Mozambique, Tanzania and Zimbabwe.

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