Fragmentation production of doubly heavy baryons

Baryons with a single heavy quark are being studied experimentally at present. Baryons with two units of heavy flavor will be abundantly produced not only at future colliders, but also at existing facilities. In this paper we study the production via heavy quark fragmentation of baryons containing two heavy quarks at the Tevatron, the LHC, HERA, and the NLC. The production rate is woefully small at HERA and at the NLC, but significant at $pp$ and $p\bar{p}$ machines. We present distributions in various kinematical variables in addition to the integrated cross sections at hadron colliders.Comment: 13 pages, macro package epsfig needed, 6 .eps figure files in a separate uuencoded, compressed and tarred file; complete paper available at http://www.physics.carleton.ca/~mad/papers/paper.p

Impact of clinical phenotypes on management and outcomes in European atrial fibrillation patients: a report from the ESC-EHRA EURObservational Research Programme in AF (EORP-AF) General Long-Term Registry

Background: Epidemiological studies in atrial fibrillation (AF) illustrate that clinical complexity increase the risk of major adverse outcomes. We aimed to describe European AF patients\u2019 clinical phenotypes and analyse the differential clinical course. Methods: We performed a hierarchical cluster analysis based on Ward\u2019s Method and Squared Euclidean Distance using 22 clinical binary variables, identifying the optimal number of clusters. We investigated differences in clinical management, use of healthcare resources and outcomes in a cohort of European AF patients from a Europe-wide observational registry. Results: A total of 9363 were available for this analysis. We identified three clusters: Cluster 1 (n = 3634; 38.8%) characterized by older patients and prevalent non-cardiac comorbidities; Cluster 2 (n = 2774; 29.6%) characterized by younger patients with low prevalence of comorbidities; Cluster 3 (n = 2955;31.6%) characterized by patients\u2019 prevalent cardiovascular risk factors/comorbidities. Over a mean follow-up of 22.5 months, Cluster 3 had the highest rate of cardiovascular events, all-cause death, and the composite outcome (combining the previous two) compared to Cluster 1 and Cluster 2 (all P <.001). An adjusted Cox regression showed that compared to Cluster 2, Cluster 3 (hazard ratio (HR) 2.87, 95% confidence interval (CI) 2.27\u20133.62; HR 3.42, 95%CI 2.72\u20134.31; HR 2.79, 95%CI 2.32\u20133.35), and Cluster 1 (HR 1.88, 95%CI 1.48\u20132.38; HR 2.50, 95%CI 1.98\u20133.15; HR 2.09, 95%CI 1.74\u20132.51) reported a higher risk for the three outcomes respectively. Conclusions: In European AF patients, three main clusters were identified, differentiated by differential presence of comorbidities. Both non-cardiac and cardiac comorbidities clusters were found to be associated with an increased risk of major adverse outcomes

Delaying BCG immunotherapy onset after transurethral resection of non-muscle-invasive bladder cancer is associated with adverse survival outcomes

Purpose This study was carried out to assess whether a prolonged time between primary transurethral resection of non-muscle-invasive bladder cancer (TURB) and implementation of bacillus Calmette-Guerin (BCG) immunotherapy (time to BCG; TTBCG) is associated with adverse oncological survival in patients with T1 high-grade (HG) non-muscle-invasive bladder cancer (NMIBC). Materials and methods Data on 429 patients from 13 tertiary care centers with primary T1HG NMIBC treated with reTURB and maintenance BCG between 2001 and 2019 were retrospectively reviewed. Change-point regression was applied following Muggeo's approach. The population was divided into subgroups according to TTBCG, whereas the recurrence-free survival (RFS) and progression-free survival (PFS) were estimated with log-rank tests. Additionally, Cox regression analyses were performed. Due to differences in baseline patient characteristics, propensity-score-matched analysis (PSM) and inverse-probability weighting (IPW) were implemented. Results The median TTBCG was 95 days (interquartile range (IQR): 71-127). The change-point regression analysis revealed a gradually increasing risk of recurrence with growing TTBCG. The risk of tumor progression gradually increased until a TTBCG of approximately 18 weeks. When the study population was divided into two subgroups (time intervals: <= 101 and > 101 days), statistically significant differences were found for both RFS (p = 0.029) and PFS (p = 0.005). Furthermore, in patients with a viable tumor at reTURB, there were no differences in RFS and PFS. After both PSM and IPW, statistically significant differences were found for both RFS and PFS, with worse results for longer TTBCG. Conclusion This study shows that delaying BCG immunotherapy after TURB of T1HG NMIBC is associated with an increased risk of tumor recurrence and progression