Thermoluminescence properties and kinetic parameters of ß-irradiated Turkish slate stone.

The current study includes a detailed investigation of the thermoluminescence (TL) characteristics and kinetic analysis of beta-irradiated slate stone from Mugla, Turkey. The heating treatment above 400 °C enhanced the visible TL intensity of the maxima, but the trap system is significantly modified with thermal annealing at temperatures higher than 700 °C. The structural, morphological, and chemical analyses of the samples were verified by X-ray diffraction, scanning electron microscope equipped with energy dispersive X-ray spectroscopy, and atomic absorption spectroscopy techniques, respectively. The TL dosimetric parameters of annealed slate stone including TL glow curves, reusability, fading characteristics, dose response, and heating rate behavior have been studied in detail. There are four apparent TL maxima in the glow curves for both non-annealed and annealed powdered samples, while the natural emission has shown a presence of 395 °C TL maximum as a form of spurious signal that was observed within a few hours during the storage time analysis as well. The material has proven to have very good reusability within the confidence interval (less than ± 5%). A linear response in the dose range of 0.1-103 Gy was achieved when the peak maximum at 258 °C is examined. The kinetic analysis was achieved using TM-Tstop, initial rise, and computing glow curve deconvolution methods. The TL glow curve of the beta-irradiated slate stone annealed at 700 °C consisted of twelve overlapping TL peaks by following first- and general order kinetics.

Posttransplant Urinary Tract Infection Rates and Graft Outcome in Kidney Transplantation for End-Stage Renal Disease Due to Reflux Nephropathy Versus Chronic Glomerulonephritis.

BACKGROUND: The goal of this study was to evaluate posttransplant urinary tract infection (UTI) rates and graft outcome in kidney transplantation for end-stage renal disease (ESRD) due to vesicoureteral reflux (VUR)-related reflux nephropathy (RN) versus chronic glomerulonephritis (CGN). METHODS: A total of 62 patients with ESRD who underwent kidney transplantation for VUR-related RN (VUR-RN group, n = 31; mean ± standard deviation age, 34.1 ± 6.0 years; 58.1% female) or CGN (CGN group, n = 31; mean age, 34.2 ± 6.8 years; 71.0% male) at our unit between January 1996 and January 2011 were included in this retrospective study. Baseline recipient and donor characteristics, renal replacement therapy, posttransplant data on serum creatinine levels, graft outcome, and UTIs were recorded. Posttransplant UTIs and graft outcome were compared between the VUR-RN and CGN groups, as well as between patients with and without pretransplant nephrectomy in the VUR-RN group. RESULTS: The frequency of overall (72 vs 18 of 90; P = .05) UTI episodes was significantly higher in the VUR-RN group than in the CGN group; Escherichia coli (64.2%) was the most common pathogen. The VUR-RN and CGN groups were similar in terms of 1-year (100.0% for each), 5-year (95.8% vs 96.8%), and 10-year (82.0% vs 96.8%) graft survival. VUR-RN patients with and without nephrectomy were similar in terms of 1-year (100.0% for each), 5-year (91.7% vs 85.7%), and 10-year (81.5% vs 85.7%) graft survival. CONCLUSIONS: Our findings indicate kidney transplantation is a safe and effective option in ESRD patients with RN secondary to VUR. It resulted in high 1-year, 5-year, and 10-year graft survival rates.

Urinary uric acid excretion as an indicator of severe hypoxia and mortality in patients with obstructive sleep apnea and chronic obstructive pulmonary disease.

OBJECTIVE: Uric acid (UA) is the end product of adenosine triphosphate degradation, and could increase due to hypoxia. We investigated the association of UA metabolites with nocturnal hypoxemia, apnea-hypopnea index (AHI), noninvasive mechanical ventilation (NIMV) usage and five-year mortality. MATERIALS/SUBJECTS AND METHODS: We obtained urinary specimen before and after the night polysomnography in order to measure UA excretion and overnight change in urinary UA/creatinine ratio (ΔUA/Cr) in 75 subjects (14 controls, 15 chronic obstructive pulmonary disease (COPD) without nocturnal hypoxemia (NH), 15 COPD with NH, 16 obstructive sleep apnea syndrome (OSAS) without NH, 15 OSAS with NH). Percentage of time spent below SaO2 of 90% (T90%) for >10% of sleep time was considered as nocturnal hypoxemia. Patients were contacted after 5 years with a questionnaire including information on the use of NIMV treatment (n: 58) and urinary specimen analysis (n: 35). RESULTS: T90% was found to be significantly correlated with UA excretion (coefficient: 0.005, 95%CI: 0.003-0.007) and ΔUA/Cr (coefficient: 0.8, 95%CI: 0.3-1.2) after adjustments for age, gender, body mass index and apnea-hypopnea index. Median and IQR (interquartile range) of baseline UA excretion were 0.79 (0.51-0.89) and 0.41 (0.31-0.55) in 10 deceased and 58 surviving patients, respectively (p=0.001). UA excretion median and IQR of baseline and 5 years of NIMV treatment were 0.41 (0.36-0.57) and 0.29 (0.23-0.37), respectively (p=0.01). CONCLUSION: UA excretion, as a marker of tissue hypoxia, may be useful in the management of OSA and COPD patients.

Renal Damage Frequency in Patients with Solitary Kidney and Factors That Affect Progression.

Background. The aim of this study is to assess renal damage incidence in patients with solitary kidney and to detect factors associated with progression. Methods. Medical records of 75 patients with solitary kidney were investigated retrospectively and divided into two groups: unilateral nephrectomy (group 1) and unilateral renal agenesis/dysplasia (group 2). According to the presence of kidney damage, each group was divided into two subgroups: group 1a/b and group 2a/b. Results. Patients in group 1 were older than those in group 2 (p = 0.001). 34 patients who comprise group 1a had smaller kidney size (p = 0.002) and higher uric acid levels (p = 0.028) than those in group 1b at presentation. Uric acid levels at first and last visit were associated with renal damage progression (p = 0.004, 0.019). 18 patients who comprise group 2a were compared with those in group 2b in terms of presence of DM (p = 0.038), HT (p = 0.003), baseline proteinuria (p = 0.014), and uric acid (p = 0.032) levels and group 2a showed higher rates for each. Progression was more common in patients with DM (p = 0.039), HT (p = 0.003), higher initial and final visit proteinuria (p = 0.014, for both), and higher baseline uric acid levels (p = 0.047). Conclusions. The majority of patients with solitary kidney showed renal damage at presentation. Increased uric acid level is a risk factor for renal damage and progression. For early diagnosis of renal damage and reducing the risk of progression, patients should be referred to a nephrologist as early as possible.

Adaptive support ventilation for faster weaning in COPD: a randomised controlled trial.

Adaptive support ventilation (ASV) is a closed-loop ventilation mode that can act both as pressure support ventilation (PSV) and pressure-controlled ventilation. Weaning with ASV shows promising results, mainly in post-cardiac surgery patients. The aim of the present randomised controlled study was to test the hypothesis that weaning with ASV could reduce the weaning duration in patients with chronic obstructive pulmonary disease (COPD) when compared with PSV. From among 435 COPD patients admitted to the intensive care unit (ICU) during a 20-month period, 97 were enrolled. Patients were assigned at random to either ASV or PSV as a weaning mode. Compared with PSV, ASV provided shorter weaning times (median 24 (interquartile range 20-62) h versus 72 (24-144) h, p=0.041) with similar weaning success rates (35 out of 49 for ASV and 33 out of 48 for PSV). Length of stay in the ICU was also shorter with ASV but the difference was not statistically significant. This study suggests that ASV may be used in the weaning of COPD patients with the advantage of shorter weaning times. Further studies are needed to investigate the role and potential advantages of ASV in the weaning period of different patient groups.