793 research outputs found

    BPS states of D=4 N=1 supersymmetry

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    We find the combinations of momentum and domain-wall charges corresponding to BPS states preserving 1/4, 1/2 or 3/4 of D=4 N=1 supersymmetry, and we show how the supersymmetry algebra implies their stability. These states form the boundary of the convex cone associated with the Jordan algebra of 4×44\times 4 real symmetric matrices, and we explore some implications of the associated geometry. For the Wess-Zumino model we derive the conditions for preservation of 1/4 supersymmetry when one of two parallel domain-walls is rotated and in addition show that this model does not admit any classical configurations with 3/4 supersymmetry. Our analysis also provides information about BPS states of N=1 D=4 anti-de Sitter supersymmetry.Comment: Latex, 27 pages. Various corrections and improvements including an expanded discussion on BPS states in ad

    Variation in Intraoperative and Postoperative Utilization for 3 Common General Surgery Procedures.

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    ObjectiveThe aim of this study was to understand variation in intraoperative and postoperative utilization for common general surgery procedures.Summary background dataReducing surgical costs is paramount to the viability of hospitals.MethodsRetrospective analysis of electronic health record data for 7762 operations from 2 health systems. Adult patients undergoing laparoscopic cholecystectomy, appendectomy, and inguinal/femoral hernia repair between November 1, 2013 and November 30, 2017 were reviewed for 3 utilization measures: intraoperative disposable supply costs, procedure time, and postoperative length of stay (LOS). Crossed hierarchical regression models were fit to understand case-mixed adjusted variation in utilization across surgeons and locations and to rank surgeons.ResultsThe number of surgeons performing each type of operation ranged from 20 to 63. The variation explained by surgeons ranged from 8.9% to 38.2% for supply costs, from 15.1% to 54.6% for procedure time, and from 1.3% to 7.0% for postoperative LOS. The variation explained by location ranged from 12.1% to 26.3% for supply costs, from 0.2% to 2.5% for procedure time, and from 0.0% to 31.8% for postoperative LOS. There was a positive correlation (ρ = 0.49, P = 0.03) between surgeons' higher supply costs and longer procedure times for hernia repair, but there was no correlation between other utilization measures for hernia repair and no correlation between any of the utilization measures for laparoscopic appendectomy or cholecystectomy.ConclusionsSurgeons are significant drivers of variation in surgical supply costs and procedure time, but much less so for postoperative LOS. Intraoperative and postoperative utilization profiles can be generated for individual surgeons and may be an important tool for reducing surgical costs

    N‑Linked Glycosylation Prevents Deamidation of Glycopeptide and Glycoprotein

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    Deamidation has been recognized as a common spontaneous pathway of protein degradation and a prevalent concern in the pharmaceutical industry; deamidation caused the reduction of protein/peptide drug efficacy and shelf life in several cases. More importantly, deamidation of physiological proteins is related to several human diseases and considered a timer for the diseases. N-linked glycosylation has a variety of significant biological functions, and it interestingly occurs right on the deamidation site-asparagine. It has been perceived that N-glycosylation could prevent deamidation, but experimental support is still lacking for clearly understanding the role of N-glycosylation on deamidation. Our results presented that deamidation is prevented by naturally occurring N-linked glycosylation. Glycopeptides and corresponding nonglycosylated peptides were used to compare their deamidation rates. All the nonglycosylated peptides have different half-lives ranging from one to 20 days, for the corresponding glycosylated peptides; all the results showed that the deamidation reaction was significantly reduced by the introduction of N-linked glycosylation. A glycoprotein, RNase B, also showed a significantly elongated deamidation half-life compared to nonglycosylated protein RNase A. At last, N-linked glycosylation on INGAP-P, a therapeutic peptide, increased the deamidation half-life of INGAP-P as well as its therapeutic potency

    String Tensions and Three Dimensional Confining Gauge Theories

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    In the context of gauge/gravity duality, we try to understand better the proposed duality between the fractional D2-brane supergravity solutions of (Nucl. Phys. B 606 (2001) 18, hep-th/0101096) and a confining 2+1 dimensional gauge theory. Based on the similarities between this fractional D2-brane solution and D3-brane supergravity solutions with more firmly established gauge theory duals, we conjecture that a confining q-string in the 2+1 dimensional gauge theory is dual to a wrapped D4-brane. In particular, the D4-brane looks like a string in the gauge theory directions but wraps a S**3 in S**4 in the transverse geometry. For one of the supergravity solutions, we find a near quadratic scaling law for the tension: Tq(Nq)T \sim q (N-q). Based on the tension, we conjecture that the gauge theory dual is SU(N) far in the infrared. We also conjecture that a quadratic or near quadratic scaling is a generic feature of confining 2+1 dimensional SU(N) gauge theories.Comment: 23 pages, 2 figure

    Emergent Quantum Near-Criticality from Baryonic Black Branes

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    We find new black 3-brane solutions describing the "conifold gauge theory" at nonzero temperature and baryonic chemical potential. Of particular interest is the low-temperature limit where we find a new kind of weakly curved near-horizon geometry; it is a warped product AdS_2 x R^3 x T^{1,1} with warp factors that are powers of the logarithm of the AdS radius. Thus, our solution encodes a new type of emergent quantum near-criticality. We carry out some stability checks for our solutions. We also set up a consistent ansatz for baryonic black 2-branes of M-theory that are asymptotic to AdS_4 x Q^{1,1,1}.Comment: 29 pages, 4 figures; v2 discussion of entropy revised, minor changes; v3 note added, minor improvements, version published in JHE

    Rituximab versus intravenous cyclophosphamide in patients with connective tissue disease-associated interstitial lung disease in the UK (RECITAL): a double-blind, double-dummy, randomised, controlled, phase 2b trial

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    BACKGROUND: Rituximab is often used as rescue therapy in interstitial lung disease (ILD) associated with connective tissue disease (CTD), but has not been studied in clinical trials. This study aimed to assess whether rituximab is superior to cyclophosphamide as a treatment for severe or progressive CTD associated ILD. METHODS: We conducted a randomised, double-blind, double-dummy, phase 2b trial to assess the superiority of rituximab compared with cyclophosphamide. Patients aged 18-80 years with severe or progressive ILD related to scleroderma, idiopathic inflammatory myositis, or mixed CTD, recruited across 11 specialist ILD or rheumatology centres in the UK, were randomly assigned (1:1) to receive rituximab (1000 mg at weeks 0 and 2 intravenously) or cyclophosphamide (600 mg/m2 body surface area every 4 weeks intravenously for six doses). The primary endpoint was rate of change in forced vital capacity (FVC) at 24 weeks compared with baseline, analysed using a mixed-effects model with random intercepts, adjusted for baseline FVC and CTD type. Prespecified secondary endpoints reported in this Article were change in FVC at 48 weeks versus baseline; changes from baseline in 6 min walk distance, diffusing capacity of the lung for carbon monoxide (DLCO), physician-assessed global disease activity (GDA) score, and quality-of-life scores on the St George's Respiratory Questionnaire (SGRQ), King's Brief Interstitial Lung Disease (KBILD) questionnaire, and European Quality of Life Five-Dimension (EQ-5D) questionnaire at 24 and 48 weeks; overall survival, progression-free survival, and time to treatment failure; and corticosteroid use. All endpoints were analysed in the modified intention-to-treat population, which comprised all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov (NCT01862926). FINDINGS: Between Dec 1, 2014, and March 31, 2020, we screened 145 participants, of whom 101 participants were randomly allocated: 50 (50%) to receive cyclophosphamide and 51 (50%) to receive rituximab. 48 (96%) participants in the cyclophosphamide group and 49 (96%) in the rituximab group received at least one dose of treatment and were included in analyses; 43 (86%) participants in the cyclophosphamide group and 42 (82%) participants in the rituximab group completed 24 weeks of treatment and follow-up. At 24 weeks, FVC was improved from baseline in both the cyclophosphamide group (unadjusted mean increase 99 mL [SD 329]) and the rituximab group (97 mL [234]); in the adjusted mixed-effects model, the difference in the primary endpoint at 24 weeks was -40 mL (95% CI -153 to 74; p=0·49) between the rituximab group and the cyclophosphamide group. KBILD quality-of-life scores were improved at 24 weeks by a mean 9·4 points (SD 20·8) in the cyclophosphamide group and 8·8 points (17·0) in the rituximab group. No significant differences in secondary endpoints were identified between the treatment groups, with the exception of change in GDA score at week 48, which favoured cyclophosphamide (difference 0·90 [95% CI 0·11 to 1·68]). Improvements in lung function and respiratory-related quality-of-life measures were observed in both treatment groups. Lower corticosteroid exposure over 48 weeks of follow-up was recorded in the rituximab group. Two (4%) of 48 participants who received cyclophosphamide and three (6%) of 49 who received rituximab died during the study, all due to complications of CTD or ILD. Overall survival, progression-free survival, and time to treatment failure did not significantly differ between the two groups. All participants reported at least one adverse event during the study. Numerically fewer adverse events were reported by participants receiving rituximab (445 events) than those receiving cyclophosphamide (646 events). Gastrointestinal and respiratory disorders were the most commonly reported adverse events in both groups. There were 62 serious adverse events of which 33 occurred in the cyclophosphamide group and 29 in the rituximab group. INTERPRETATION: Rituximab was not superior to cyclophosphamide to treat patients with CTD-ILD, although participants in both treatment groups had increased FVC at 24 weeks, in addition to clinically important improvements in patient-reported quality of life. Rituximab was associated with fewer adverse events. Rituximab should be considered as a therapeutic alternative to cyclophosphamide in individuals with CTD-ILD requiring intravenous therapy. FUNDING: Efficacy and Mechanism Evaluation Programme (Medical Research Council and National Institute for Health Research, UK)

    Einstein-Yang-Mills Theory with a Massive Dilaton and Axion: String-Inspired Regular and Black Hole Solutions

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    We study the classical theory of a non-Abelian gauge field (gauge group SU(2)SU(2)) coupled to a massive dilaton, massive axion and Einstein gravity. The theory is inspired by the bosonic part of the low-energy heterotic string action for a general Yang-Mills field, which we consider to leading order after compactification to (3+1)(3+1) dimensions. We impose the condition that spacetime be static and spherically symmetric, and we introduce masses via a dilaton-axion potential associated with supersymmetry (SUSY)-breaking by gaugino condensation in the hidden sector. In the course of describing the possible non-Abelian solutions of the simplified theory, we consider in detail two candidates: a massive dilaton coupled to a purely magnetic Yang-Mills field, and a massive axion field coupled to a non-Abelian dyonic configuration, in which the electric and magnetic fields decay too rapidly to correspond to any global gauge charge. We discuss the feasibility of solutions with and without a nontrivial dilaton for the latter case, and present numerical regular and black hole solutions for the former.Comment: 44 page
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