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Packing -dimensional balls into a -dimensional container
Get PDFIn this article, we consider the problems of finding in dimensions a minimum-volume axis-parallel box, a minimum-volume arbitrarily-oriented box and a minimum-volume convex body into which a given set of -dimensional unit-radius balls can be packed under translations. The computational problem is neither known to be NP-hard nor to be in NP. We give a constant-factor approximation algorithm for each of these containers based on a reduction to finding a shortest Hamiltonian path in a weighted graph, which in turn models the problem of stabbing the centers of the input balls while keeping them disjoint. We also show that for such balls, a container of volume is always sufficient and sometimes necessary. As a byproduct, this implies that for there is no finite size -dimensional convex body into which all -dimensional unit-radius balls can be packed simultaneously
Conduction system pacing vs. biventricular pacing for cardiac resynchronization
Get PDFAims: There are limited prospective randomized studies comparing left bundle branch area pacing (LBBAP) and biventricular (BiV) pacing for cardiac resynchronization therapy (CRT). The study tested whether LBBAP is non-inferior to BiV pacing in patients with Class I indication for CRT. Methods and results: The CSP-SYNC study is an investigator-initiated, randomized, single-centre study. Sixty-two patients were randomized 1:1 to LBBAP or BiV. The primary study endpoint was the change in left ventricular ejection fraction (LVEF) at 6 months. Secondary endpoints included changes in echo and clinical parameters after 6 months and 12 months. Thirty-one patients were randomized to each arm. Most patients were males (71%), and 32% had ischaemic cardiomyopathy. At 6 months, similar improvement of LVEF was observed in the LBBAP group compared to the BiV group [14.0% (95% confidence interval (CI): 11.2–16.8) in LBBAP vs. 8.5% (95% CI: 5.6–11.2) in BiV] with a mean intergroup difference of 5.6% (95% CI: 1.6–9.5P < 0.001 for non-inferiority). Both groups showed comparable decrease in LVESV [−64 mL (95% CI: −78 to −50) vs. −40 mL (95% CI: −54 to −25) respectively, mean difference −24 mL (CI 95%: −44 to −4)P < 0.001 for non-inferiority] and changes in 6-min walk test (P < 0.001 for non-inferiority) and NYHA class (P = 0.011 for non-inferiority). Temporal trends of LV remodelling and heart failure hospitalization rates were also comparable. Conclusion: In patients with a Class I indication for CRT, LBBAP was non-inferior to BiV pacing in improving LVEF and provided similar structural and electrical remodelling
Dataset for the review article "From plastic use in the construction and built environment to state-of-the-art circular economy solutions to combat microplastic pollution"
No full textThe dataset supports the data presented in the article “From plastic use in the construction and built environment to state-of-the-art circular economy solutions to combat microplastic pollution” (https://doi.org/10.1186/s12302-025-01228-0). It consists of a single Excel worksheet compiling data on the number of published studies related to microplastics in general and to microplastics originating from the building and construction sector to illustrate the evolution of research attention
Gastric cancer surgery in high volume university medical centers influences long-term survival
Get PDFBackground: Short-term gastric cancer surgery outcomes depend greatly on hospital surgical volume, whereas long-term survival studies show conflicting results. This study evaluated the effect of surgical volume on the long-term survival of patients who underwent surgery for gastric cancer in Slovenia. Methods: A retrospective cohort analysis was performed using the Slovenian Cancer Registry data. Patients diagnosed between 2016 and 2020 who underwent gastric cancer surgery were categorized into high- and low-volume centers. High-volume centers were defined, as the two University Medical Centers (Ljubljana and Maribor), which together treated 76.4 % of all patients during the study period. Survival analysis was conducted using Kaplan-Meier overall survival and Pohar-Perme net survival estimators, with predefined subgroup analysis. Cox proportional hazards models assessed the independent association between center volume and overall survival. Results: Among the 652 patients, 498 (76.4 %) underwent surgery at high-volume centers (44,2-55,4 mean surgeries/year), which demonstrated higher median overall survival (4.9 vs. 3.2 years) and improved overall and net 1-, 3-, and 5-year survival rates compared with low-volume centers (0,2-6,2 mean surgeries/year). This differences persisted in stratified analyses by stage and neoadjuvant therapy but not by age. In multivariable Cox analysis the hazard ratio remained directionally favorable for high-volume centers but was not statistically significant. Conclusions: Overall, high-volume centers were consistently associated with better long-term survival after gastric cancer surgery in Slovenia, supporting further evaluation of centralization strategies. Future policies should aim to balance the benefits of centralization while maintaining equitable access to timely and high-quality surgical treatment, regardless of location or socioeconomic status
Platonic configurations of points and lines
Get PDFWe present some methods for constructing connected spatial geometric configurations of points and lines, preserved by the same isometries of Euclidean space as the predetermined Platonic solid. In this paper, we are mainly interested in configurations , , and , but also in unbalanced configurations , , and