238 research outputs found

    Study of Foaming Properties and Effect of the Isomeric Distribution of Some Anionic Surfactants

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    Using different reaction conditions of photosulfochlorination of n-dodecane, two samples of anionic surfactants of sulfonate type are obtained. Their micellar behavior has been already reported and the relationship between their isomeric distribution and their chemical structures and micellar behaviors have been more thoroughly explored. In this investigation, we screened the foaming properties (foaming power and foam stability) by a standardized method very similar to the Ross–Miles foaming tests to identify which surfactants are suitable for applications requiring high foaming, or, alternatively, low foaming. The results obtained for the synthesized surfactants are compared to those obtained for an industrial sample of secondary alkanesulfonate (Hostapur 60) and to those of a commercial sample of sodium dodecylsulfate used as reference for anionic surfactants. The foam formation and foam stability of aqueous solutions of the two samples of dodecanesulfonate are compared as a function of their isomeric distribution. These compounds show good foaming power characterized in most cases by metastable or dry foams. The highest foaming power is obtained for the sample rich in primary isomers which also produces foam with a relatively high stability. For the sample rich in secondary isomers we observe under fixed conditions a comparable initial foam height but the foam stability turns out to be low. This property is interesting for applications requiring low foaming properties such as dishwashing liquid for machines. The best results are observed near and above the critical micellar concentrations and at 25 C for both the samples

    The consistency condition for the three-point function in dissipative single-clock inflation

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    We generalize the consistency condition for the three-point function in single field inflation to the case of dissipative, multi-field, single-clock models. We use the recently introduced extension of the effective field theory of inflation that accounts for dissipative effects, to provide an explicit proof to leading (non-trivial) order in the generalized slow roll parameters and mixing with gravity scales. Our results illustrate the conditions necessary for the validity of the consistency relation in situations with many degrees of freedom relevant during inflation, namely that there is a preferred clock. Departures from this condition in forthcoming experiments would rule out not only single field but also a large class of multi-field models.Comment: 26+11 page

    Effects and Detectability of Quasi-Single Field Inflation in the Large-Scale Structure and Cosmic Microwave Background

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    Quasi-single field inflation predicts a peculiar momentum dependence in the squeezed limit of the primordial bispectrum which smoothly interpolates between the local and equilateral models. This dependence is directly related to the mass of the isocurvatons in the theory which is determined by the supersymmetry. Therefore, in the event of detection of a non-zero primordial bispectrum, additional constraints on the parameter controlling the momentum-dependence in the squeezed limit becomes an important question. We explore the effects of these non-Gaussian initial conditions on large-scale structure and the cosmic microwave background, with particular attention to the galaxy power spectrum at large scales and scale-dependence corrections to galaxy bias. We determine the simultaneous constraints on the two parameters describing the QSF bispectrum that we can expect from upcoming large-scale structure and cosmic microwave background observations. We find that for relatively large values of the non-Gaussian amplitude parameters, but still well within current uncertainties, galaxy power spectrum measurements will be able to distinguish the QSF scenario from the predictions of the local model. A CMB likelihood analysis, as well as Fisher matrix analysis, shows that there is also a range of parameter values for which Planck data may be able distinguish between QSF models and the related local and equilateral shapes. Given the different observational weightings of the CMB and LSS results, degeneracies can be significantly reduced in a joint analysis.Comment: 27 pages, 14 figure

    Comprehensive analysis of the major histocompatibility complex in systemic sclerosis identifies differential HLA associations by clinical and serological subtypes

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    Objective: The greatest genetic effect reported for systemic sclerosis (SSc) lies in the major histocompatibility complex (MHC) locus. Leveraging the largest SSc genome-wide association study, we aimed to fine-map this region to identify novel human leucocyte antigen (HLA) genetic variants associated with SSc susceptibility and its main clinical and serological subtypes. Methods: 9095 patients with SSc and 17 584 controls genome-wide genotyped were used to impute and test single-nucleotide polymorphisms (SNPs) across the MHC, classical HLA alleles and their composite amino acid residues. Additionally, patients were stratified according to their clinical and serological status, namely, limited cutaneous systemic sclerosis (lcSSc), diffuse cutaneous systemic sclerosis (dcSSc), anticentromere (ACA), antitopoisomerase (ATA) and anti-RNApolIII autoantibodies (ARA). Results: Sequential conditional analyses showed nine SNPs, nine classical alleles and seven amino acids that modelled the observed associations with SSc. This confirmed previously reported associations with HLA-DRB1∗11:04 and HLA-DPB1∗13:01, and revealed a novel association of HLA-B∗08:01. Stratified analyses showed specific associations of HLA-DQA1∗02:01 with lcSSc, and an exclusive association of HLA-DQA1∗05:01 with dcSSc. Similarly, private associations were detected in HLA-DRB1∗08:01 and confirmed the previously reported association of HLA-DRB1∗07:01 with ACA-positive patients, as opposed to the HLA-DPA1∗02:01 and HLA-DQB1∗03:01 alleles associated with ATA presentation. Conclusions: This study confirms the contribution of HLA class II and reveals a novel association of HLA class I with SSc, suggesting novel pathways of disease pathogenesis. Furthermore, we describe specific HLA associations with SSc clinical and serological subtypes that could serve as biomarkers of disease severity and progression

    Does hand involvement in systemic sclerosis limit completion of patient-reported outcome measures?

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    The objective of this analysis is to examine whether the severity of systemic sclerosis (SSc)-hand involvement influences patient-reported outcome measure (PROM) completion rate in a US cohort of early disease. Participants included SSc patients with less than 5 years disease duration consented and enrolled in the Collaborative, National, Quality, and Efficacy Registry (CONQUER) between June 2018 and December 2019. Participants\u27 socio-demographics, hand clinical features (severe modified Rodnan skin score, presence of small joint contractures, acro-osteolysis, calcinosis, and digital ulcers), and completion rates of seven PROMs including a Resource Use Questionnaire were analyzed. Cohort characteristics and baseline PROM completion were evaluated. Multivariable logistic regression assessed the relationship between hand limitations and PROM incompletion at several time points using generalized estimating equations. At the time of data lock, 339 CONQUER subjects had a total of 600 visits available for analysis. Calcinosis (odds ratio [OR] 6.35, confidence interval [CI] 2.41-16.73 and acro-osteolysis OR 3.88 (1.57-9.55) were significantly associated with incomplete PROM. The Resource Use Questionnaire was the PROM most commonly not completed. Increasing age was correlated with resource use questionnaire incompletion rate. Acro-osteolysis and calcinosis were associated with lower PROM completion rates in a US SSc cohort, independent of the length of the questionnaires or the modality of administration (electronic or paper). Resource Use Questionnaires are important for understanding the economic impact and burden of chronic disease; however, in this study, it had lower completion rates than PROMs devoted to clinical variables. Key points •Multiple strategies are needed to ensure optimal completion of PROM in longitudinal cohort studies. Even if patients request electronic surveys, we have found it is important to follow up incomplete surveys with paper forms provided at the time of a clinical visit. •The Resource Utilization Questionnaire was lengthy and prone to non-completion in the younger population. •Acro-osteolysis and calcinosis were associated with reduced PROM completion rates

    Anomalous Dimensions and Non-Gaussianity

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    We analyze the signatures of inflationary models that are coupled to strongly interacting field theories, a basic class of multifield models also motivated by their role in providing dynamically small scales. Near the squeezed limit of the bispectrum, we find a simple scaling behavior determined by operator dimensions, which are constrained by the appropriate unitarity bounds. Specifically, we analyze two simple and calculable classes of examples: conformal field theories (CFTs), and large-N CFTs deformed by relevant time-dependent double-trace operators. Together these two classes of examples exhibit a wide range of scalings and shapes of the bispectrum, including nearly equilateral, orthogonal and local non-Gaussianity in different regimes. Along the way, we compare and contrast the shape and amplitude with previous results on weakly coupled fields coupled to inflation. This signature provides a precision test for strongly coupled sectors coupled to inflation via irrelevant operators suppressed by a high mass scale up to 1000 times the inflationary Hubble scale.Comment: 40 pages, 10 figure

    Comprehensive analysis of the major histocompatibility complex in systemic sclerosis identifies differential HLA associations by clinical and serological subtypes

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    Objective: The greatest genetic effect reported for systemic sclerosis (SSc) lies in the major histocompatibility complex (MHC) locus. Leveraging the largest SSc genome-wide association study, we aimed to fine-map this region to identify novel human leucocyte antigen (HLA) genetic variants associated with SSc susceptibility and its main clinical and serological subtypes. Methods: 9095 patients with SSc and 17 584 controls genome-wide genotyped were used to impute and test single-nucleotide polymorphisms (SNPs) across the MHC, classical HLA alleles and their composite amino acid residues. Additionally, patients were stratified according to their clinical and serological status, namely, limited cutaneous systemic sclerosis (lcSSc), diffuse cutaneous systemic sclerosis (dcSSc), anticentromere (ACA), antitopoisomerase (ATA) and anti-RNApolIII autoantibodies (ARA). Results: Sequential conditional analyses showed nine SNPs, nine classical alleles and seven amino acids that modelled the observed associations with SSc. This confirmed previously reported associations with HLA-DRB1*11:04 and HLA-DPB1*13:01, and revealed a novel association of HLA-B*08:01. Stratified analyses showed specific associations of HLA-DQA1*02:01 with lcSSc, and an exclusive association of HLA-DQA1*05:01 with dcSSc. Similarly, private associations were detected in HLA-DRB1*08:01 and confirmed the previously reported association of HLA-DRB1*07:01 with ACA-positive patients, as opposed to the HLA-DPA1*02:01 and HLA-DQB1*03:01 alleles associated with ATA presentation. Conclusions: This study confirms the contribution of HLA class II and reveals a novel association of HLA class I with SSc, suggesting novel pathways of disease pathogenesis. Furthermore, we describe specific HLA associations with SSc clinical and serological subtypes that could serve as biomarkers of disease severity and progression.Funding: This work was supported by the Spanish Ministry of Science and Innovation (grant ref. SAF2015-66761-P and RTI20181013 (32-B-100)), Red de Investigación en Inflamación y Enfermedades Reumáticas from Instituto de Salud Carlos III (RD16/0012/0013) and grants from National Institutes of Health (R01AR073284) and DoD (W81XWH-16-1-0296). MAH was funded by the Spanish Ministry of Science and Innovation through the Juan de la Cierva Incorporacion program (ref. IJC2018-035131-I). GO, AB and ALH were supported by the NIHR Manchester Biomedical Research Centre and Versus Arthritis (grant ref 21754)

    Cardiac metabolomics and autopsy in a patient with early diffuse systemic sclerosis presenting with dyspnea: A case report

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    Introduction: Diffuse systemic sclerosis is associated with high mortality; however, the pathogenesis of cardiac death in these patients is not clear. Case presentation: A 56-year-old Caucasian female patient presented with dyspnea and requested to donate her body to science in order to improve understanding of diffuse systemic sclerosis pathogenesis. She had extensive testing for dyspnea including pulmonary function tests, an echocardiogram, cardiac magnetic resonance imaging, and right heart catheterization to characterize her condition. Her case highlights the morbidity seen in this disease, including the presence of extensive skin thickening, digital ulcerations, and scleroderma renal crisis. Conclusion: In this case report, we present the finding of cardiac tissue metabolomics, which may indicate a problem with vasodilation as a contributor to cardiac death in diffuse systemic sclerosis. The use of autopsy and tissue metabolomics in rare disease may help clarify disease pathogenesis
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