Tritium ((3)H) is produced in nuclear reactors via several neutron-induced reactions [(2)H(n, gamma)(3)H, (6)Li(n, alpha)(3)H, (10)B(n, 2alpha)(3)H, (14)N(n, (3)H)(12)C, and ternary fission (fission yield <0.01%)]. Typically, (3)H is present as tritiated water (HTO) and can become adsorbed into structural concrete from the surface inward where it will be held in a weakly bound form. However, a systematic analysis of a sequence of subsamples taken from a reactor bioshield using combustion and liquid scintillation analysis has identified two forms of (3)H, one weakly bound and one strongly bound. The strongly bound tritium, which originates from neutron capture on trace lithium ((6)Li) within mineral phases, requires temperatures in excess of 350 degrees C to achieve quantitative recovery. The weakly bound form of tritium can be liberated at significantly lower temperatures (100 degrees C) as HTO and is associated with dehydration of hydrous mineral components. Without an appreciation that two forms of tritium can exist in reactor bioshields, the (3)H content of samples may be severely underestimated using conventional analytical approaches. These findings exemplify the need to develop robust radioactive waste characterization procedures in support of nuclear decommissioning programs.

BackgroundUreteral stent removal using an extraction string is advantageous because it can obviate an invasive cystoscopy, but there is a paucity of data on how patients feel about it, and how bothersome or beneficial it is.We performed this study to evaluate patients’ preference for stent removal using an extraction string and which parameters could affect it.MethodsIn total, 114 consecutive patients undergoing ureteral stent insertion after ureteroscopic stone removal (URS) for unilateral recurrent ureter stones were enrolled. Patients were randomized to a string group or a no string group.Stent removal was performed on the first visit within 7 days postoperatively. All patients were asked to complete the ureteral stent symptom questionnaire, to rate the degree of pain during stent removal using a visual analog scale (VAS) and to answer to questions regarding their preference.ResultsNo significant differences were found in domain total scores including urinary symptoms (p = 0.17), pain (p = 0.62), general health (p = 0.37), work performance (p = 0.41). However, regarding separate questions for ‘dysuria’ and ‘difficulties with heavy physical activity’, there were significant intergroup differences (p = 0.03 and p = 0.04, respectively). Particular, a significantly higher proportion of patients in the string group checked ‘stoppage of sexual intercourse due to stent-related problems’ than in the no string group (p = 0.03).VAS score on stent removal was significantly higher in the no string group than the string group (p = 0.005).Among the patients who remember the experience of an indwelling ureteral stent in the past, 85 % (17/20) of the no string group answered ‘No’ to the question of ‘difference between the methods used in this time and in the past’. On the contrary, 84.2 % (16/19) answered ‘Yes’ to the same question in the string group. And, all 16 patients of the string group who noted differences between the methods preferred ureteral stent removal using an extraction string to the past method.ConclusionsDespite of minor increased morbidity related to the extraction string, patients preferred ureteral stent removal using the extraction string after URS. The patients with the extraction string felt less pain on stent removal than flexible cystoscopic stent removal.Trial registrationKCT0001700. The trial was registered in the Clinical ResearchInformation Service (CRiS), Republic of Korea; registration date: 18/11/2015.

Purpose: The aim of this study is to identify the risk factors for development of sepsis in patients with obstructive acute pyelonephritis (APN) associated with urinary tract calculi. Materials and Methods: Between January 2004 and December 2013, 73 patients with obstructive APN associated with upper urinary tract calculi were admitted to our institution. Medical records of 73 patients (14 men and 59 women, mean age of 57 years) were reviewed retrospectively. The risk factors for sepsis were analyzed using multivariate logistic regression analysis. Results: Of 73 patients, 37 (50.7%) developed sepsis. Old age and history of hypertension were more common in the sepsis group than in the non-sepsis group (p＜0.001 and p=0.018). The white blood cell count, neutrophil count, plateletto-lymphocyte ratio, neutrophil-to-lymphocyte ratio (NLR), and C-reactive protein level were significantly higher in the sepsis group (p=0.011, p=0.001, p=0.042, p＜0.001 and p=0.006, respectively). Lymphocyte count, platelet count, and albumin level were significantly lower in the sepsis group (p＜0.001, p=0.008 and p＜0.001, respectively). Multivariate logistic regression analysis indicated that old age (odds ratio [OR], 2.13; p=0.023), decrease in serum albumin level (OR, 4.27; p=0.041), and high NLR (OR, 3.83; p=0.037) were independent risk factors for development of sepsis. Conclusions: Elderly patients with obstructive APN associated with urinary tract calculi who have low serum albumin levels and high NLR should be treated carefully against development of sepsis.

PurposeThe aim of this study was to investigate the changing pattern in the use of intravenous pyelogram (IVP), conventional computed tomography (CT), and non-contrast-enhanced computed tomography (NECT) for evaluation of patients with acute flank pain.Materials and MethodsWe retrospectively reviewed the medical records of 2,180 patients with acute flank pain who had visited Bundang Jesaeng General Hospital between January 2008 and December 2012 and analyzed the use of IVP, conventional CT, and NECT for these patients.ResultsDuring the study period there was a significant increase in NECT use (p<0.001) and a significant decrease in IVP use (p<0.001). Conventional CT use was also increased significantly (p=0.001). During this time the proportion of patients with acute flank pain who were diagnosed with urinary calculi did not change significantly (p=0.971).ConclusionsThere was a great shift in the use of imaging study from IVP to NECT between 2008 and 2012 for patients with acute flank pain.