30 research outputs found
An Artificially Lattice Mismatched Graphene/Metal Interface: Graphene/Ni/Ir(111)
We report the structural and electronic properties of an artificial
graphene/Ni(111) system obtained by the intercalation of a monoatomic layer of
Ni in graphene/Ir(111). Upon intercalation, Ni grows epitaxially on Ir(111),
resulting in a lattice mismatched graphene/Ni system. By performing Scanning
Tunneling Microscopy (STM) measurements and Density Functional Theory (DFT)
calculations, we show that the intercalated Ni layer leads to a pronounced
buckling of the graphene film. At the same time an enhanced interaction is
measured by Angle-Resolved Photo-Emission Spectroscopy (ARPES), showing a clear
transition from a nearly-undisturbed to a strongly-hybridized graphene
-band. A comparison of the intercalation-like graphene system with flat
graphene on bulk Ni(111), and mildly corrugated graphene on Ir(111), allows to
disentangle the two key properties which lead to the observed increased
interaction, namely lattice matching and electronic interaction. Although the
latter determines the strength of the hybridization, we find an important
influence of the local carbon configuration resulting from the lattice
mismatch.Comment: 9 pages, 3 figures, Accepted for publication in Phys. Rev.
Researching COVID to enhance recovery (RECOVER) tissue pathology study protocol: Rationale, objectives, and design.
ImportanceSARS-CoV-2 infection can result in ongoing, relapsing, or new symptoms or organ dysfunction after the acute phase of infection, termed Post-Acute Sequelae of SARS-CoV-2 (PASC), or long COVID. The characteristics, prevalence, trajectory and mechanisms of PASC are poorly understood. The objectives of the Researching COVID to Enhance Recovery (RECOVER) tissue pathology study (RECOVER-Pathology) are to: (1) characterize prevalence and types of organ injury/disease and pathology occurring with PASC; (2) characterize the association of pathologic findings with clinical and other characteristics; (3) define the pathophysiology and mechanisms of PASC, and possible mediation via viral persistence; and (4) establish a post-mortem tissue biobank and post-mortem brain imaging biorepository.MethodsRECOVER-Pathology is a cross-sectional study of decedents dying at least 15 days following initial SARS-CoV-2 infection. Eligible decedents must meet WHO criteria for suspected, probable, or confirmed infection and must be aged 18 years or more at the time of death. Enrollment occurs at 7 sites in four U.S. states and Washington, DC. Comprehensive autopsies are conducted according to a standardized protocol within 24 hours of death; tissue samples are sent to the PASC Biorepository for later analyses. Data on clinical history are collected from the medical records and/or next of kin. The primary study outcomes include an array of pathologic features organized by organ system. Causal inference methods will be employed to investigate associations between risk factors and pathologic outcomes.DiscussionRECOVER-Pathology is the largest autopsy study addressing PASC among US adults. Results of this study are intended to elucidate mechanisms of organ injury and disease and enhance our understanding of the pathophysiology of PASC
New Monomeric Stilbenoids from Peanut (Arachis hypogaea) Seeds Challenged by an Aspergillus flavus Strain
Two new stilbene derivatives have
been isolated from peanut seeds
challenged by an Aspergillus flavus strain, along with chiricanine B, which has not been previously
reported from peanuts, as well as a stilbenoid reported previously
only as a synthetic product. The structures of these new putative
phytoalexins were determined by analysis of <sup>1</sup>H and <sup>13</sup>C NMR, HRESIMS, MS<sup><i>n</i></sup>, and UV data.
The new stilbenoids were named arahypin-13 (<b>21</b>), arahypin-14
(<b>22</b>), and arahypin-15 (<b>23</b>). Together with
other known bioactive peanut stilbenoids that were also produced in
the challenged seeds, these new compounds may play a defensive role
against invasive fungi
International academic careers : personal reflections
University business schools are increasingly adopting an international outlook as they compete for students who are aiming for global careers. A natural consequence of university internationalization is the need to internationalize the academic workforce, resulting in increasing attention on, and recognition for, the academic with international teaching and research experience. Yet the effort and complexity involved in making an international academic transition is often overlooked. Academic institutions' efforts to recruit international academics often outpace their expertise and support in the inpatriation and orientation processes. Academics interested in international mobility may find it difficult to obtain helpful information prior to arrival in the new country and encounter problems in adjusting to their new job and surroundings. This paper presents personal experiences of a select group of academics who have moved between countries. Their reports illustrate differences in teaching loads, language, student behavior, recruitment and career-ladder issues across countries, as well as strategies they have used to adapt to their new surroundings.18 page(s
Non uniform nanosecond gate delay of hybrid pixel detectors
A simple experiment to characterize the gating properties of X-ray area detectors using pulsed X-ray sources is presented. For a number of time-resolved experiments the gating uniformity of area detectors is important. Relative gating delays between individual modules and readout chips of PILATUS2 series area X-ray detectors have been observed. For three modules of a PILATUS 300K-W unit the maximum gating offset between the modules is found to be as large as 30 ns. On average, the first photosensor module is found to be triggered 15 ns and 30 ns later than the second and the third modules, respectively
The shared frameshift mutation landscape of microsatellite-unstable cancers suggests immunoediting during tumor evolution
The immune system can recognize and attack cancer cells, especially those with a high load of mutation-induced neoantigens. Such neoantigens are abundant in DNA mismatch repair (MMR)-deficient, microsatellite-unstable (MSI) cancers. MMR deficiency leads to insertion/deletion (indel) mutations at coding microsatellites (cMS) and to neoantigen-inducing translational frameshifts. Here, we develop a tool to quantify frameshift mutations in MSI colorectal and endometrial cancer. Our results show that frameshift mutation frequency is negatively correlated to the predicted immunogenicity of the resulting peptides, suggesting counterselection of cell clones with highly immunogenic frameshift peptides. This correlation is absent in tumors with Beta-2-microglobulin mutations, and HLA-A*02:01 status is related to cMS mutation patterns. Importantly, certain outlier mutations are common in MSI cancers despite being related to frameshift peptides with functionally confirmed immunogenicity, suggesting a possible driver role during MSI tumor evolution. Neoantigens resulting from shared mutations represent promising vaccine candidates for prevention of MSI cancers. DNA mismatch repair (MMR)-deficient cancers with microsatellite-instability are characterized by a high load of frameshift mutation-derived neoantigens. Here, by mapping the frameshift mutation landscape and predicting the immunogenicity of the resulting peptides, the authors show evidence of immunoediting in MMR-deficient colorectal and endometrial cancers.Hereditary cancer genetic