The Visibility Freeze-Tag Problem

In the Freeze-Tag Problem, we are given a set of robots at points inside some metric space. Initially, all the robots are frozen except one. That robot can awaken (or “unfreeze”) another robot by moving to its position, and once a robot is awakened, it can move and help to awaken other robots. The goal is to awaken all the robots in the shortest time. The Freeze-Tag Problem has been studied in different metric spaces: graphs and Euclidean spaces. In this thesis, we look at the Freeze-Tag Problem in polygons, and we introduce the Visibility Freeze-Tag Problem, where one robot can awaken another robot by “seeing” it. Furthermore, we introduce a variant of the Visibility Freeze-Tag Problem, called the Line/Point Freeze Tag Problem, where each robot lies on an awakening line, and one robot can awaken another robot by touching its awakening line. We survey the current results for the Freeze-Tag Problem in graphs, Euclidean spaces and polygons. Since the Visibility Freeze-Tag Problem bears some resemblance to the Watchman Route Problem, we also survey the background literature on the Watchman Route Problem. We show that the Freeze-Tag Problem in polygons and the Visibility Freeze-Tag Problem are NP-hard, and we present an O(n)-approximation algorithm for the Visibility Freeze-Tag Problem. For the Line/Point Freeze-Tag Problem, we give a polynomial time algorithm for the special case where all the awakening lines are parallel to each other. We prove that the general case is NP-hard, and we present an O(1)- approximation algorithm

Discovery of Iodinated Polyfluoroalkyl Acids by Nontarget Mass-Spectrometric Analysis

Per- and polyfluoroalkyl acids (PFAAs) including polyfluoroalkyl carboxylic acids and polyfluoroalkyl sulfonic acids are a large category of crucial environmental pollutants of global concern. Besides known PFAAs, numerous unknown species may exist in the environment, urgently needing discovery and characterization. This study implemented nontarget analysis for a group of novel PFAA pollutants, viz. iodinated PFAAs (I-PFAAs) in wastewater by liquid chromatography-high-resolution mass spectrometry in combination with an iodine-specific data-processing algorithm. The algorithm took into account of the diagnostic fragment iodine ion (I–) together with carbon and sulfur isotopologue distributions. In total, 21 I-PFAA formulas involving 24 congeners were identified. Semiquantification was conducted, and the total concentrations of I-PFAAs were 1.9-311.9 ng/mL, indicating non-negligible pollution of I-PFAAs in the wastewater. The determined concentrations along with predicted environmental behaviors and toxicities demonstrate that I-PFAAs merit further in-depth investigation. The analytical method including the instrumental analysis and data-processing algorithm can be extended to screening and identification of I-PFAAs in other matrices. Furthermore, the analysis results for the first time provide cognition on the occurrence features and pollution status of I-PFAAs in the environment

Neutrophil-to-lymphocyte ratio for predicting postoperative recurrence in Crohn’s disease patients with isolated anastomotic lesions

Background: Patients with isolated anastomotic lesions (iAL) are common in postoperative Crohn’s disease (CD) and have heterogeneous prognosis. Objectives: To investigate the prognostic value of neutrophil-to-lymphocyte ratio (NLR) in CD patients with iAL. Design: A bicenter retrospective cohort study. Methods: CD patients who received ileocolonic resection from 2013 and 2020 and had a modified Rutgeerts score of i2a were recruited. NLR was determined within 1 week around the initial endoscopy after ileocolectomy. The primary outcome was clinical recurrence. Kaplan–Meier method and Cox hazard regression analysis were utilized to assess the association between candidate variables and outcomes of interest. Results: In total, 411 postoperative CD patients were preliminarily reviewed and 83 patients were eligible. In total, 36 (48.6%) patients experienced clinical recurrence with a median follow-up time of 16.3 (interquartile range, 9.7–26.3) months. NLR > 2.45 and age at surgery >45 years had higher cumulative incidence of clinical recurrence in the Kaplan–Meier analysis. After adjusted for potential confounders, NLR > 2.45 was the only independent risk factor for clinical recurrence, with an adjusted hazard ratio (HR) of 2.88 [95% confidence interval (CI), 1.39–6.00; p  = 0.005]. Furthermore, a risk score based on NLR and age at surgery were built to further stratify patients. Compared to those who scored 0, patients with a score of 1 and 2 had an adjusted HR of 2.48 (95% CI, 1.22–5.02) and 6.97 (95% CI, 2.19–22.16) for developing clinical recurrence, respectively. Conclusions: NLR is a promising prognostic biomarker for CD patients with iAL. The utilization of NLR and the risk score to stratify patients may facilitate the personalized management in patients with iAL

sj-tif-4-tag-10.1177_17562848231165129 – Supplemental material for Neutrophil-to-lymphocyte ratio for predicting postoperative recurrence in Crohn’s disease patients with isolated anastomotic lesions

Supplemental material, sj-tif-4-tag-10.1177_17562848231165129 for Neutrophil-to-lymphocyte ratio for predicting postoperative recurrence in Crohn’s disease patients with isolated anastomotic lesions by Rirong Chen, Chao Li, Kang Chao, Yizhe Tie, Jieqi Zheng, Huili Guo, Zhirong Zeng, Li Li, Minhu Chen and Shenghong Zhang in Therapeutic Advances in Gastroenterology</p

sj-tif-2-tag-10.1177_17562848231165129 – Supplemental material for Neutrophil-to-lymphocyte ratio for predicting postoperative recurrence in Crohn’s disease patients with isolated anastomotic lesions

Supplemental material, sj-tif-2-tag-10.1177_17562848231165129 for Neutrophil-to-lymphocyte ratio for predicting postoperative recurrence in Crohn’s disease patients with isolated anastomotic lesions by Rirong Chen, Chao Li, Kang Chao, Yizhe Tie, Jieqi Zheng, Huili Guo, Zhirong Zeng, Li Li, Minhu Chen and Shenghong Zhang in Therapeutic Advances in Gastroenterology</p

sj-docx-1-tag-10.1177_17562848231165129 – Supplemental material for Neutrophil-to-lymphocyte ratio for predicting postoperative recurrence in Crohn’s disease patients with isolated anastomotic lesions

Supplemental material, sj-docx-1-tag-10.1177_17562848231165129 for Neutrophil-to-lymphocyte ratio for predicting postoperative recurrence in Crohn’s disease patients with isolated anastomotic lesions by Rirong Chen, Chao Li, Kang Chao, Yizhe Tie, Jieqi Zheng, Huili Guo, Zhirong Zeng, Li Li, Minhu Chen and Shenghong Zhang in Therapeutic Advances in Gastroenterology</p

sj-tif-3-tag-10.1177_17562848231165129 – Supplemental material for Neutrophil-to-lymphocyte ratio for predicting postoperative recurrence in Crohn’s disease patients with isolated anastomotic lesions

Supplemental material, sj-tif-3-tag-10.1177_17562848231165129 for Neutrophil-to-lymphocyte ratio for predicting postoperative recurrence in Crohn’s disease patients with isolated anastomotic lesions by Rirong Chen, Chao Li, Kang Chao, Yizhe Tie, Jieqi Zheng, Huili Guo, Zhirong Zeng, Li Li, Minhu Chen and Shenghong Zhang in Therapeutic Advances in Gastroenterology</p