388 research outputs found
Shockwave synthesis of a thallium-based superconductor with a novel defect microstructure
We report the shock-wave synthesis at a yield ≳80% by volume of the single copper layer thalliumsuperconductor of composition Tl2Ba2CuO6. The as-synthesized material displays zero resistance near 55 K and a diamagnetic onset to bulk superconductivity at 70 K. Lattice imaging indicates that the superconducting microcrystals consist of a novel defect microstructure involving an intergrowth of two copper-oxygen layers probably interleaved by partial thallium and barium occupancy
An integrated approach to prognosis using protein microarrays and nonparametric methods
Over the past several years, multivariate approaches have been developed that address the problem of disease diagnosis. Here, we report an integrated approach to the problem of prognosis that uses protein microarrays to measure a focused set of molecular markers and non-parametric methods to reveal non-linear relationships among these markers, clinical variables, and patient outcome. As proof-of-concept, we applied our approach to the prediction of early mortality in patients initiating kidney dialysis. We found that molecular markers are not uniformly prognostic, but instead vary in their value depending on a combination of clinical variables. This may explain why reports in this area aiming to identify prognostic markers, without taking into account clinical variables, are either conflicting or show that markers have marginal prognostic value. Just as treatments are now being tailored to specific subsets of patients, our results show that prognosis can also benefit from a ‘personalized' approach
First-Trimester Follistatin-Like-3 Levels in Pregnancies Complicated by Subsequent Gestational Diabetes Mellitus
Objective: To determine whether maternal levels of follistatin-like-3 (FSTL3), an inhibitor of activin and myostatin involved in glucose homeostasis, are altered in the first trimester of pregnancies complicated by subsequent gestational diabetes mellitus (GDM). Research Design and Methods: This was a nested case-control study of subjects enrolled in a prospective cohort of pregnant women with and without GDM (2 abnormal values on a 100-g glucose tolerance test at ~28 weeks of gestation). We measured FSTL3 levels in serum collected during the first trimester of pregnancy. Logistic regression analyses were used to determine the risk of GDM. Results: Women who developed GDM (n = 37) had lower first-trimester serum levels of FSTL3 compared with women who did not (n = 127) (median 10,789 [interquartile range 7,013-18,939] vs. 30,670 [18,370-55,484] pg/ml, P < 0.001). When subjects were divided into tertiles based on FSTL3 levels, women with the lowest levels demonstrated a marked increase in risk for developing GDM in univariate (odds ratio 11.2 [95% CI 3.6-35.3]) and multivariate (14.0 [4.1-47.9]) analyses. There was a significant negative correlation between first-trimester FSTL3 levels and ~28-week nonfasting glucose levels (r = -0.30, P < 0.001). Conclusions: First-trimester FSTL3 levels are associated with glucose intolerance and GDM later in pregnancy
User characteristics and outcomes from a national digital mental health service: an observational study of registrants of the Australian MindSpot Clinic.
Background:Interest is growing in digital and telehealth delivery of mental health services, but data are scarce on outcomes in routine care. The federally funded Australian MindSpot Clinic provides online and telephone psychological assessment and treatment services to Australian adults. We aimed to summarise demographic characteristics and treatment outcomes of patients registered with MindSpot over the first 7 years of clinic operation. Methods:We used an observational design to review all patients who registered for assessment with the MindSpot Clinic between Jan 1, 2013, and Dec 31, 2019. We descriptively analysed the demographics, service preferences, and baseline symptoms of patients. Among patients enrolled in a digital treatment course, we evaluated scales of depression (Patient Health Questionnaire-9 [PHQ-9]) and anxiety (Generalized Anxiety Disorder 7-Item Scale [GAD-7]), as primary measures of treatment outcome, from the screening assessment to post-treatment and a 3 month follow-up. The Kessler Psychological Distress 10-Item Plus Scale was also used to assess changes in general distress and disability, and course satisfaction was measured post-treatment. Outcomes:A total of 121 652 screening assessments were started, of which 96 018 (78·9%) were completed. The mean age of patients was 35·7 years (SD 13·8) and 88 702 (72·9%) were women. Based on available assessment data, 36 866 (34·5%) of 106 811 participants had never previously spoken to a health professional about their symptoms, and most people self-reported symptoms of anxiety (88 879 [81·9%] of 108 494) or depression (78 803 [72·6%] of 108 494), either alone or in combination, at baseline. 21 745 patients started treatment in a therapist-guided online course, of whom 14 503 (66·7%) completed treatment (≥four of five lessons). Key trends in service use included an increase in the proportion of people using MindSpot primarily for assessment and information, from 52·6% in 2013 to 66·7% in 2019, while the proportion primarily seeking online treatment decreased, from 42·6% in 2013 to 26·7% in 2019. Effect sizes and percentage changes were large for estimated mean scores on the PHQ-9 and GAD-7 from assessment to post-treatment (PHQ-9, Cohen's d effect size 1·40 [95% CI 1·37-1·43]; and GAD-7, 1·45 [1·42-1·47]) and the 3 month follow-up (PHQ-9, 1·36 [1·34-1·38]; and GAD-7, 1·42 [1·40-1·44]); proportions of patients with reliable symptom deterioration (score increase of ≥6 points [PHQ-9] or ≥5 points [GAD-7]) were low post-treatment (of 13 058 respondents, 184 [1·4%] had symptom deterioration on the PHQ-9 and 282 [2·2%] on the GAD-7); and patient satisfaction rates were high (12 452 [96·6%] of 12 895 respondents would recommend the course and 12 433 [96·7%] of 12 860 reported the course worthwhile). We also observed small improvements in disability following treatment as measured by days out of role. Interpretation:Our findings indicate improvement in psychological symptoms and positive reception among patients receiving online mental health treatment. These results support the addition of digital services such as MindSpot as a component in contemporary national mental health systems. Funding:None
Fabry disease: progression of nephropathy, and prevalence of cardiac and cerebrovascular events before enzyme replacement therapy
Background. In Fabry disease, progressive glycolipid accumulation leads to organ damage and early demise, but the incidence of renal, cardiac and cerebrovascular events has not been well characterized
MicroRNA Expression Data Reveals a Signature of Kidney Damage following Ischemia Reperfusion Injury
Ischemia reperfusion injury (IRI) is a leading cause of acute kidney injury, a common problem worldwide associated with significant morbidity and mortality. We have recently examined the role of microRNAs (miRs) in renal IRI using expression profiling. Here we conducted mathematical analyses to determine if differential expression of miRs can be used to define a biomarker of renal IRI. Principal component analysis (PCA) was combined with spherical geometry to determine whether samples that underwent renal injury as a result of IRI can be distinguished from controls based on alterations in miR expression using our data set consisting of time series measuring 571 miRs. Using PCA, we examined whether changes in miR expression in the kidney following IRI have a distinct direction when compared to controls based on the trajectory of the first three principal components (PCs) for our time series. We then used Monte Carlo methods and spherical geometry to assess the statistical significance of these directions. We hypothesized that if IRI and control samples exhibit distinct directions, then miR expression can be used as a biomarker of injury. Our data reveal that the pattern of miR expression in the kidney following IRI has a distinct direction based on the trajectory of the first three PCs and can be distinguished from changes observed in sham controls. Analyses of samples from immunodeficient mice indicated that the changes in miR expression observed following IRI were lymphocyte independent, and therefore represent a kidney intrinsic response to injury. Together, these data strongly support the notion that IRI results in distinct changes in miR expression that can be used as a biomarker of injury
Constraining the Nature of Dark Energy using the SKA
We investigate the potential of the Square Kilometer Array Telescope (SKA) to
constrain the sound speed of dark energy. The Integrated Sachs Wolfe (ISW)
effect results in a significant power spectrum signal when CMB temperature
anisotropies are cross-correlated with galaxies detectable with the SKA in HI.
We consider using this measurement, the autocorrelation of HI galaxies and the
CMB temperature power spectrum to derive constraints on the sound speed. We
study the contributions to the cross-correlation signal made by galaxies at
different redshifts and use redshift tomography to improve the signal-to-noise.
We use a chi-square analysis to estimate the significance of detecting a sound
speed different from that expected in quintessence models, finding that there
is potential to distinguish very low sound speeds from the quintessence value.Comment: 8 pages, 8 figures; updated references for publication MNRA
Prevalence and Persistence of Uremic Symptoms in Incident Dialysis Patients
Background
Uremic symptoms are major contributors to the poor quality of life among patients on dialysis, but whether their prevalence or intensity has changed over time is unknown.
Methods
We examined responses to validated questionnaires in two incident dialysis cohort studies, the Choices for Health Outcomes in Caring for ESRD (CHOICE) study (N=926, 1995–1998) and the Longitudinal United States/Canada Incident Dialysis (LUCID) study (N=428, 2011–2017). We determined the prevalence and severity of uremic symptoms—anorexia, nausea/vomiting, pruritus, sleepiness, difficulty concentrating, fatigue, and pain—in both cohorts.
Results
In CHOICE and LUCID, respectively, mean age of the participants was 58 and 60 years, 53% and 60% were male, and 28% and 32% were black. In both cohorts, 54% of the participants had diabetes. Median time from dialysis initiation to the symptoms questionnaires was 45 days for CHOICE and 77 days for LUCID. Uremic symptom prevalence in CHOICE did not change from baseline to 1-year follow-up and was similar across CHOICE and LUCID. Baseline symptom prevalence in CHOICE and LUCID was as follows: anorexia (44%, 44%, respectively), nausea/vomiting (36%, 43%), pruritus (72%, 63%), sleepiness (86%, 68%), difficulty concentrating (55%, 57%), fatigue (89%, 77%), and pain (82%, 79%). In both cohorts, >80% of patients had three or more symptoms and >50% had five or more symptoms. The correlation between individual symptoms was low (ρ<0.5 for all comparisons). In CHOICE, no clinical or laboratory parameter was strongly associated with multiple symptoms.
Conclusions
The burden of uremic symptoms among patients on dialysis is substantial and has not changed in the past 15 years. Improving quality of life will require identification of the factors that underlie the pathogenesis of uremic symptoms and better ways of removing the toxins that are responsible
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