Gallbladder Stone Prevalence and Related Factors in Predialysis Chronic Kidney Disease Patients.

BACKGROUND: The aim of this study was to determine the prevalence and factors associated with gallbladder stone in patients with predialysis chronic kidney disease. METHODS: This cross-sectional study retrospectively examined follow-up data of patients with chronic kidney disease between January 2015 and December 2020 at the Health Sciences University Antalya Training and Research Hospital who had undergone abdominal ultrasonography for any reason. Patients with gallbladder stone on abdominal ultrasonography and history of cholecystectomy due to gallbladder stone were identified as the gallstone group. The prevalence of gallbladder stone was determined according to disease stage. Patients with and without gallbladder stone were compared in terms of demographic and clinical characteristics and laboratory parameters that may be associated with the development of gallbladder stone. RESULTS: A total of 511 patients had chronic kidney disease (stages 3, 4, and 5 in 303 [59.3%], 176 [34.4%], and 32 [6.3%], respectively). The gallstone prevalence rates were 25.1%, 30.1%, and 46.9% in stage 3, 4, and 5 chronic kidney disease, respectively, and that in all the patients was 28.2% (95% CI: 24.3-32.3, P = .026). Logistic regression analysis revealed that increased age (odds ratio: 1.045; 95% CI: 1.027-1.063, P < .001) and decreased estimated glomerular filtration rate (odds ratio: 0.974; 95% CI: 0.956-0.991, P = .004) were associated with gallbladder stone. CONCLUSION: The prevalence of gallbladder stone was high in the predialysis patients with chronic kidney disease and increased with increasing disease stage. High age and low estimated glomerular filtration rate were associated with gallbladder stone formation.

Carbon cycle instability and orbital forcing during the Middle Eocene Climatic Optimum.

The Middle Eocene Climatic Optimum (MECO) is a global warming event that occurred at about 40 Ma. In comparison to the most known global warming events of the Paleogene, the MECO has some peculiar features that make its interpretation controversial. The main peculiarities of the MECO are a duration of ~500 kyr and a carbon isotope signature that varies from site to site. Here we present new carbon and oxygen stable isotopes records (δ13C and δ18O) from three foraminiferal genera dwelling at different depths throughout the water column and the sea bottom during the middle Eocene, from eastern Turkey. We document that the MECO is related to major oceanographic and climatic changes in the Neo-Tethys and also in other oceanic basins. The carbon isotope signature of the MECO is difficult to interpret because it is highly variable from site to site. We hypothesize that such δ13C signature indicates highly unstable oceanographic and carbon cycle conditions, which may have been forced by the coincidence between a 400 kyr and a 2.4 Myr orbital eccentricity minimum. Such forcing has been also suggested for the Cretaceous Oceanic Anoxic Events, which resemble the MECO event more than the Cenozoic hyperthermals.

Photo/photochemical oxidation of cyanide and metal-cyanide complexes: ultraviolet A versus ultraviolet C.

Degradation of free cyanide (CN(-)), weak-acid dissociable (WAD) (Zn(CN)4(2-), Cu(CN)3(2-)) and strong-acid dissociable (SAD) (Fe(CN)6(4-) cyanide complexes by photo and photochemical oxidation with ultraviolet (UV) light and H2O2 was investigated. The experiments were performed in batch reactors under ultraviolet A (UVA; 395 nm) and ultraviolet C (UVC; 254 nm) light; the degradation efficiency was followed in terms of free cyanide, complex and metal concentrations. UVC and UVA photo-oxidations were found to be equally effective in CN(-) and WAD degradation, while the degradation of the SAD complex was more difficult for both UV wavelengths, and UVC was more effective. The initial pH of the solution has influenced the degradation of all cyanide species and the optimum initial pH was evaluated as 10.5 for CN(-) and Cu(CN)3(2-); 12.0 for Zn(CN)4(2-) and 9.0 for Fe(CN)6(4-) degradation. Photochemical oxidation using H202 provided higher degradation at shorter durations with both UVA and UVC. Time-dependent variations in free cyanide and metal concentrations have indicated that metal-cyanide complexes are firstly degraded into metal and CN(-) ions, followed by oxidation of CN(-) ions, while metals in the system were partially removed as hydroxide precipitates. Therefore, depending upon the effluent requirements, the studied UV photo/photochemical oxidations were offered as either a pre-treatment method for the separation of metal and the cyanide, or as an oxidation technology to degrade especially WAD complexes and CN(-). Estimated operational cost of photo-oxidation by UVC was 1.6-2.5-fold higher than UVA degradation, although degradation times were close. In the photochemical oxidation with H2O2, the operational costs of UVC and UVA degradation were closer, owing to peroxide costs, but UVC was still more expensive.