2,095 research outputs found
The Structural Basis of Ligand Recognition by Natural Killer Cell Receptors
Natural killer cells are a group of lymphocytes which function as tightly controlled surveillance operatives which identify transformed cells through a discrete balance of activating and inhibitory receptors ultimately leading to the destruction of incongruent cells. The understanding of this finely tuned balancing act has been aided by the high-resolution structure determination of activating and inhibitory receptors both alone and in complex with their ligands. This paper collates these structural studies detailing the aspects which directly relate to the natural killer cell function and serves to inform both the specialized structural biologist reader and a more general immunology audience
Explaining the Electroweak Scale and Stabilizing Moduli in M Theory
In a recent paper \cite{Acharya:2006ia} it was shown that in theory vacua
without fluxes, all moduli are stabilized by the effective potential and a
stable hierarchy is generated, consistent with standard gauge unification. This
paper explains the results of \cite{Acharya:2006ia} in more detail and
generalizes them, finding an essentially unique de Sitter (dS) vacuum under
reasonable conditions. One of the main phenomenological consequences is a
prediction which emerges from this entire class of vacua: namely gaugino masses
are significantly suppressed relative to the gravitino mass. We also present
evidence that, for those vacua in which the vacuum energy is small, the
gravitino mass, which sets all the superpartner masses, is automatically in the
TeV - 100 TeV range.Comment: 73 pages, 39 figures, Minor typos corrected, Figures and References
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Severity and management of psoriasis within primary care
Background: Scottish Intercollegiate Guidelines Network and National Institute of Health and Care Excellence guidelines stress the importance of assessing patients with psoriasis for psoriatic arthritis, comorbidities associated with severe disease and quality of life (QoL). The purpose of the study was to evaluate the primary care management of psoriasis in relation to disease severity and QoL from apatient's perspective. Methods: A cross-sectional survey of adults (≥18 years) with psoriasis managed in primary care was conducted in Scotland over 1-year (2012-2013). Patients with psoriasis were identified and invited to participate in the online/telephone survey. The questionnaires included; Dermatology Life Quality Index (DLQI), Self-Administered Psoriasis Area and Severity Index (SAPASI), Psoriasis Epidemiology Screening Tool (PEST). The primary outcome measure was DLQI. Secondary outcomes included; demographics; comorbidities; involvement of different body sites; SAPASI and PEST scores. Relationships between measures were analysed using univariate analysis. Results: The mean age of patients (n = 905) was 54.5 years (SD = 16.1), 436 (48.2 %) were men, and median DLQI and SAPASI scores were 4.0 and 6.0, respectively. Current psoriasis treatments were topical only (587, 64.9 %), oral medications or phototherapy (122, 13.5%), biologics (26, 3 %) and none (156, 17.2 %). Despite SIGN recommendations,256 of 391 patients (65.5 %) with a DLQI >5 (at least a moderate effect on QoL) had not seen a specialist during the past year. According to PEST scores, 259 patients (28.6 %) had symptoms suggestive of psoriatic arthritis requiring rheumatology referral. Conclusion: National recommendations are not being fully implemented in primary care in patients with psoriasis or psoriatic arthritis
SARS-CoV-2 ferritin nanoparticle vaccines elicit broad SARS coronavirus immunogenicity
The need for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) next-generation vaccines has been highlighted by the rise of variants of concern (VoCs) and the long-term threat of emerging coronaviruses. Here, we design and characterize four categories of engineered nanoparticle immunogens that recapitulate the structural and antigenic properties of the prefusion SARS-CoV-2 spike (S), S1, and receptor-binding domain (RBD). These immunogens induce robust S binding, ACE2 inhibition, and authentic and pseudovirus neutralizing antibodies against SARS-CoV-2. A spike-ferritin nanoparticle (SpFN) vaccine elicits neutralizing titers (I
The Role of the Gouy Phase in the Coherent Phase Control of the Photoionization and Photodissociation of Vinyl Chloride
We demonstrate theoretically and experimentally that the Gouy phase of a
focused laser beam may be used to control the photo-induced reactions of a
polyatomic molecule. Quantum mechanical interference between one- and
three-photon excitation of vinyl chloride produces a small phase lag between
the dissociation and ionization channels on the axis of the molecular beam.
Away from the axis, the Gouy phase introduces a much larger phase lag that
agrees quantitatively with theory without any adjustable parameters.Comment: 4 pages, 4 figure
A rational approach to heavy-atom derivative screening
In order to overcome the difficulties associated with the ‘classical’ heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom-derivative screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification
Providing Automated Verification in HOL Using MDGs
While model checking suffers from the state space explosion problem, theorem proving is quite tedious and impractical for verifying complex designs. In this work, we present a verification framework in which we attempt to strike the balance between the expressiveness of theorem proving and the efficiency and automation of state exploration techniques. To this end, we propose to integrate a layer of checking algorithms based on Multiway Decision Graphs (MDG) in the HOL theorem prover. We deeply embedded the MDG underlying logic in HOL and implemented a platform that provides a set of algorithms allowing the user to develop his/her own state-exploration based application inside HOL. While the verification problem is specified in HOL, the proof is derived by tightly combining the MDG based computations and the theorem prover facilities. We have been able to implement and experiment with different state exploration techniques within HOL such as MDG reachability analysis, equivalence and model checking
A Cysteine Zipper Stabilizes a Pre-Fusion F Glycoprotein Vaccine for Respiratory Syncytial Virus
Recombinant subunit vaccines should contain minimal non-pathogen motifs to reduce potential off-target reactivity. We recently developed a vaccine antigen against respiratory syncytial virus (RSV), which comprised the fusion (F) glycoprotein stabilized in its pre-fusion trimeric conformation by “DS-Cav1” mutations and by an appended C-terminal trimerization motif or “foldon” from T4-bacteriophage fibritin. Here we investigate the creation of a cyste- ine zipper to allow for the removal of the phage foldon, while maintaining the immunogenic- ity of the parent DS-Cav1+foldon antigen. Constructs without foldon yielded RSV F monomers, and enzymatic removal of the phage foldon from pre-fusion F trimers resulted in their dissociation into monomers. Because the native C terminus of the pre-fusion RSV F ectodomain encompasses a viral trimeric coiled-coil, we explored whether introduction of cysteine residues capable of forming inter-protomer disulfides might allow for stable trimers. Structural modeling indicated the introduced cysteines to form disulfide “rings”, with each ring comprising a different set of inward facing residues of the coiled-coil. Three sets of rings could be placed within the native RSV F coiled-coil, and additional rings could be added by duplicating portions of the coiled-coil. High levels of neutralizing activity in mice, equivalent to that of the parent DS-Cav1+foldon antigen, were elicited by a 4-ring stabilized RSV F trimer with no foldon. Structure-based alteration of a viral coiled-coil to create a cys- teine zipper thus allows a phage trimerization motif to be removed from a candidate vaccine antigen
Improved annotation of 3' untranslated regions and complex loci by combination of strand-specific direct RNA sequencing, RNA-seq and ESTs
The reference annotations made for a genome sequence provide the framework
for all subsequent analyses of the genome. Correct annotation is particularly
important when interpreting the results of RNA-seq experiments where short
sequence reads are mapped against the genome and assigned to genes according to
the annotation. Inconsistencies in annotations between the reference and the
experimental system can lead to incorrect interpretation of the effect on RNA
expression of an experimental treatment or mutation in the system under study.
Until recently, the genome-wide annotation of 3-prime untranslated regions
received less attention than coding regions and the delineation of intron/exon
boundaries. In this paper, data produced for samples in Human, Chicken and A.
thaliana by the novel single-molecule, strand-specific, Direct RNA Sequencing
technology from Helicos Biosciences which locates 3-prime polyadenylation sites
to within +/- 2 nt, were combined with archival EST and RNA-Seq data. Nine
examples are illustrated where this combination of data allowed: (1) gene and
3-prime UTR re-annotation (including extension of one 3-prime UTR by 5.9 kb);
(2) disentangling of gene expression in complex regions; (3) clearer
interpretation of small RNA expression and (4) identification of novel genes.
While the specific examples displayed here may become obsolete as genome
sequences and their annotations are refined, the principles laid out in this
paper will be of general use both to those annotating genomes and those seeking
to interpret existing publically available annotations in the context of their
own experimental dataComment: 44 pages, 9 figure
Effect of race on prediction of brain amyloidosis by plasma Aβ42/Aβ40, phosphorylated tau, and neurofilament light
BACKGROUND AND OBJECTIVES: To evaluate whether plasma biomarkers of amyloid (Aβ42/Aβ40), tau (p-tau181 and p-tau231), and neuroaxonal injury (neurofilament light chain [NfL]) detect brain amyloidosis consistently across racial groups.
METHODS: Individuals enrolled in studies of memory and aging who self-identified as African American (AA) were matched 1:1 to self-identified non-Hispanic White (NHW) individuals by age,
RESULTS: There were 76 matched pairs of AA and NHW participants (n = 152 total). For both AA and NHW groups, the median age was 68.4 years, 42% were
DISCUSSION: Models predicting brain amyloidosis using a high-performance plasma Aβ42/Aβ40 assay may provide an accurate and consistent measure of brain amyloidosis across AA and NHW groups, but models based on plasma p-tau181, p-tau231, and NfL may perform inconsistently and could result in disproportionate misdiagnosis of AA individuals
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