239 research outputs found
Accreting Protoplanets in the LkCa 15 Transition Disk
Exoplanet detections have revolutionized astronomy, offering new insights
into solar system architecture and planet demographics. While nearly 1900
exoplanets have now been discovered and confirmed, none are still in the
process of formation. Transition discs, protoplanetary disks with inner
clearings best explained by the influence of accreting planets, are natural
laboratories for the study of planet formation. Some transition discs show
evidence for the presence of young planets in the form of disc asymmetries or
infrared sources detected within their clearings, as in the case of LkCa 15.
Attempts to observe directly signatures of accretion onto protoplanets have
hitherto proven unsuccessful. Here we report adaptive optics observations of
LkCa 15 that probe within the disc clearing. With accurate source positions
over multiple epochs spanning 2009 - 2015, we infer the presence of multiple
companions on Keplerian orbits. We directly detect H{\alpha} emission from the
innermost companion, LkCa 15 b, evincing hot (~10,000 K) gas falling deep into
the potential well of an accreting protoplanet.Comment: 35 pages, 3 figures, 1 table, 9 extended data item
Secukinumab immunogenicity over 52 weeks in patients with psoriatic arthritis and ankylosing spondylitis
Objective. Secukinumab, a fully human antiinterleukin 17A monoclonal antibody, is efficacious for the treatment of psoriatic arthritis (PsA) and ankylosing spondylitis (AS). This study examined the immunogenicity of secukinumab in patients with PsA and AS exposed to secukinumab for up to 52 weeks.
Methods. Antibody bridging assays were used to assess the immunogenicity of secukinumab in patients with PsA [FUTURE 1–3 studies, and AS (MEASURE 1–4 studies)]. Evaluations were at baseline and at weeks 16 (AS only), 24, and 52. Treatment-emergent antidrug antibodies (TE-ADA) were defined as a positive ADA signal in ≥ 1 posttreatment sample in patients negative at baseline. Positive samples were analyzed for drug-neutralizing potential, and effect of TE-ADA on secukinumab pharmacokinetics, immunogenicity-related adverse events (AE), and efficacy through Week 52 were assessed.
Results. Of 1414 treated PsA and 1164 treated AS patients with samples available for immunogenicity evaluation, 5 (0.35%) and 8 (0.69%), respectively, developed TE-ADA. All but 1 PsA patient were biologic-naive; two of the 5 PsA and one of the 8 AS patients received concomitant methotrexate, and two of the 8 AS patients received concomitant sulfasalazine. Associations between TE-ADA and secukinumab dose, frequency, or administration mode were not observed. Other than one PsA patient, all TE-ADA were non-neutralizing. No TE-ADA were associated with any AE. All TE-ADA were associated with normal secukinumab pharmacokinetics and none were associated with loss of secukinumab efficacy.
Conclusion. Secukinumab treatment was associated with a low (< 1%) incidence of immunogenicity in patients with PsA or AS. (clinicaltrials.gov: NCT01392326; NCT01752634; NCT01989468; NCT01358175; NCT01649375; NCT02008916; NCT02159053)
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An exploration of patient-reported symptoms in systemic lupus erythematosus and the relationship to health-related quality of life
Objective: The aim of this study was to explore the most distressing symptoms of systemic lupus erythematosus (SLE) and determine how these relate to health-related quality of life (HRQoL), anxiety/depression, patient demographics and disease characteristics (duration, activity, organ damage).
Methods: In a cross-sectional study, patients with SLE (n=324, age 18-84 years) gave written responses regarding which SLE-related symptoms they experienced as most difficult. Their responses were categorized. Within each category, patients reporting a specific symptom were compared with non-reporters and analyzed for patient demographics, disease duration, results from the questionnaires: Medical Outcomes Study Short-Form 36, Hospital Anxiety and Depression Scale, Systemic Lupus Activity Measure, SLE disease activity index and the Systemic Lupus International Collaboration Clinics/American College of Rheumatology damage index.
Results: 23 symptom categories were identified. Fatigue (51%), Pain (50%) and Musculoskeletal distress (46%) were most frequently reported. Compared with non-reporters, only patients reporting Fatigue showed statistically significant impact on both mental and physical components of HRQoL.. Patients with no present symptoms (10%) had higher HRQoL (p<0.001) and lower levels of depression (p<0.001), anxiety (p<0.01) and disease activity (SLAM) (p<0.001).
Conclusion: Fatigue, pain or musculoskeletal distress dominated the reported symptoms in approximately half of the patients. Only patients reporting Fatigue scored lower on both mental and physical aspects of HRQoL. Our results emphasize the need for further support and interventions to ease the symptom load and improve HRQoL in patients with SLE. Our findings further indicate that this need is particularly urgent for patients with symptoms of pain or fatigue
The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets
This review addresses our current understanding of comets that venture close to the Sun, and are hence exposed to much more extreme conditions than comets that are typically studied from Earth. The extreme solar heating and plasma environments that these objects encounter change many aspects of their behaviour, thus yielding valuable information on both the comets themselves that complements other data we have on primitive solar system bodies, as well as on the near-solar environment which they traverse. We propose clear definitions for these comets: We use the term near-Sun comets to encompass all objects that pass sunward of the perihelion distance of planet Mercury (0.307 AU). Sunskirters are defined as objects that pass within 33 solar radii of the Sun’s centre, equal to half of Mercury’s perihelion distance, and the commonly-used phrase sungrazers to be objects that reach perihelion within 3.45 solar radii, i.e. the fluid Roche limit. Finally, comets with orbits that intersect the solar photosphere are termed sundivers. We summarize past studies of these objects, as well as the instruments and facilities used to study them, including space-based platforms that have led to a recent revolution in the quantity and quality of relevant observations. Relevant comet populations are described, including the Kreutz, Marsden, Kracht, and Meyer groups, near-Sun asteroids, and a brief discussion of their origins. The importance of light curves and the clues they provide on cometary composition are emphasized, together with what information has been gleaned about nucleus parameters, including the sizes and masses of objects and their families, and their tensile strengths. The physical processes occurring at these objects are considered in some detail, including the disruption of nuclei, sublimation, and ionisation, and we consider the mass, momentum, and energy loss of comets in the corona and those that venture to lower altitudes. The different components of comae and tails are described, including dust, neutral and ionised gases, their chemical reactions, and their contributions to the near-Sun environment. Comet-solar wind interactions are discussed, including the use of comets as probes of solar wind and coronal conditions in their vicinities. We address the relevance of work on comets near the Sun to similar objects orbiting other stars, and conclude with a discussion of future directions for the field and the planned ground- and space-based facilities that will allow us to address those science topics
Comparison of the 2019 European Alliance of Associations for Rheumatology/American College of Rheumatology Systemic Lupus Erythematosus Classification Criteria With Two Sets of Earlier Systemic Lupus Erythematosus Classification Criteria
Objective:
The Systemic Lupus International Collaborating Clinics (SLICC) 2012 systemic lupus erythematosus (SLE) classification criteria and the revised American College of Rheumatology (ACR) 1997 criteria are list based, counting each SLE manifestation equally. We derived a classification rule based on giving variable weights to the SLICC criteria and compared its performance to the revised ACR 1997, the unweighted SLICC 2012, and the newly reported European Alliance of Associations for Rheumatology (EULAR)/ACR 2019 criteria sets.
Methods:
The physician-rated patient scenarios used to develop the SLICC 2012 classification criteria were reemployed to devise a new weighted classification rule using multiple linear regression. The performance of the rule was evaluated on an independent set of expert-diagnosed patient scenarios and compared to the performance of the previously reported classification rules.
Results:
The weighted SLICC criteria and the EULAR/ACR 2019 criteria had less sensitivity but better specificity compared to the list-based revised ACR 1997 and SLICC 2012 classification criteria. There were no statistically significant differences between any pair of rules with respect to overall agreement with the physician diagnosis.
Conclusion:
The 2 new weighted classification rules did not perform better than the existing list-based rules in terms of overall agreement on a data set originally generated to assess the SLICC criteria. Given the added complexity of summing weights, researchers may prefer the unweighted SLICC criteria. However, the performance of a classification rule will always depend on the populations from which the cases and non-cases are derived and whether the goal is to prioritize sensitivity or specificity
A dimensioning and tolerancing methodology for concurrent engineering applications II: comprehensive solution strategy
Dimensioning and tolerancing (D&T) is a multidisciplinary problem which requires the fulfillment of a large number of dimensional requirements. However, almost all of the currently available D&T tools are only intended for use by the designer. In addition, they typically provide solutions for the requirements one at time. This paper presents a methodology for determining the dimensional specifications of the component parts and sub-assemblies of a product by satisfying all of its requirements. The comprehensive solution strategy presented here includes: a strategy for separating D&T problems into groups, the determination of an optimum solution order for coupled functional equations, a generic tolerance allocation strategy, and strategies for solving different types of D&T problems. A number of commonly used cost minimization strategies, such as the use of standard parts, preferred sizes, preferred fits, and preferred tolerances, have also been incorporated into the proposed methodology. The methodology is interactive and intended for use in a concurrent engineering environment by members of a product development team
A subset of patients with systemic lupus erythematosus fails to degrade DNA from multiple clinically relevant sources
The early use of botulinum toxin in post-stroke spasticity: study protocol for a randomised controlled trial.
BACKGROUND: Patients surviving stroke but who have significant impairment of function in the affected arm are at more risk of developing pain, stiffness and contractures. The abnormal muscle activity, associated with post-stroke spasticity, is thought to be causally associated with the development of these complications. Treatment of spasticity is currently delayed until a patient develops signs of these complications. METHODS/DESIGN: This protocol is for a phase II study that aims to identify whether using OnabotulinumtoxinA (BoNT-A) in combination with physiotherapy early post stroke when initial abnormal muscle activity is neurophysiologically identified can prevent loss of range at joints and improve functional outcomes.The trial uses a screening phase to identify which people are appropriate to be included in a double blind randomised placebo-controlled trial. All patients admitted to Sandwell and West Birmingham NHS Trust Hospitals with a diagnosis of stroke will be screened to identify functional activity in the arm. Those who have no function will be appropriate for further screening. Patients who are screened and have abnormal muscle activity identified on EMG will be given electrical stimulation to forearm extensors for 3 months and randomised to have either injections of BoNT-A or normal saline. The primary outcome measure is the action research arm test - a measure of arm function. Further measures include spasticity, stiffness, muscle strength and fatigue as well as measures of quality of life, participation and caregiver strain. TRIAL REGISTRATIONS: ISRCTN57435427, EudraCT2010-021257-39, NCT01882556
Pro-asthmatic cytokines regulate unliganded and ligand-dependent glucocorticoid receptor signaling in airway smooth muscle
To elucidate the regulation of glucocorticoid receptor (GR) signaling under pro-asthmatic conditions, cultured human airway smooth muscle (HASM) cells were treated with proinflammatory cytokines or GR ligands alone and in combination, and then examined for induced changes in ligand-dependent and -independent GR activation and downstream signaling events. Ligand stimulation with either cortisone or dexamethsone (DEX) acutely elicited GR translocation to the nucleus and, comparably, ligand-independent stimulation either with the Th2 cytokine, IL-13, or the pleiotropic cytokine combination, IL-1β/TNFα, also acutely evoked GR translocation. The latter response was potentiated by combined exposure of cells to GR ligand and cytokine. Similarly, treatment with either DEX or IL-13 alone induced GR phosphorylation at its serine-211 residue (GRSer211), denoting its activated state, and combined treatment with DEX+IL-13 elicited heightened and sustained GRSer211phosphorylation. Interestingly, the above ligand-independent GR responses to IL-13 alone were not associated with downstream GR binding to its consensus DNA sequence or GR transactivation, whereas both DEX-induced GR:DNA binding and transcriptional activity were significantly heightened in the presence of IL-13, coupled to increased recruitment of the transcriptional co-factor, MED14. The stimulated GR signaling responses to DEX were prevented in IL-13-exposed cells wherein GRSer211 phosphorylation was suppressed either by transfection with specific serine phosphorylation-deficient mutant GRs or treatment with inhibitors of the MAPKs, ERK1/2 and JNK. Collectively, these novel data highlight a heretofore-unidentified homeostatic mechanism in HASM cells that involves pro-asthmatic cytokine-driven, MAPK-mediated, non-ligand-dependent GR activation that confers heightened glucocorticoid ligand-stimulated GR signaling. These findings raise the consideration that perturbations in this homeostatic cytokine-driven GR signaling mechanism may be responsible, at least in part, for the insensirtivity to glucocorticoid therapy that is commonly seen in individuals with severe asthma
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