Extreme ultraviolet resonant inelastic X-ray scattering (RIXS) at a seeded free-electron laser.

In the past few years, we have been witnessing an increased interest for studying materials properties under non-equilibrium conditions. Several well established spectroscopies for experiments in the energy domain have been successfully adapted to the time domain with sub-picosecond time resolution. Here we show the realization of high resolution resonant inelastic X-ray scattering (RIXS) with a stable ultrashort X-ray source such as an externally seeded free electron laser (FEL). We have designed and constructed a RIXS experimental endstation that allowed us to successfully measure the d-d excitations in KCoF3 single crystals at the cobalt M2,3-edge at FERMI FEL (Elettra-Sincrotrone Trieste, Italy). The FEL-RIXS spectra show an excellent agreement with the ones obtained from the same samples at the MERIXS endstation of the MERLIN beamline at the Advanced Light Source storage ring (Berkeley, USA). We established experimental protocols for performing time resolved RIXS experiments at a FEL source to avoid X ray-induced sample damage, while retaining comparable acquisition time to the synchrotron based measurements. Finally, we measured and modelled the influence of the FEL mixed electromagnetic modes, also present in externally seeded FELs, and the beam transport with ~120 meV experimental resolution achieved in the presented RIXS setup.

Changes in metal availability during sediment oxidation and the correlation with the immobilization potential.

Fractionation of metals (Pb, Cd, Ni, Zn, Cu and Cr) in severely contaminated sediment has been investigated to determine its speciation and eco-toxic potential at the beginning of the experiment and after 18 months of sediment oxidation. Pb, Ni and Zn showed a high risk, while Cu, Cd and Cr showed low to medium risk at the beginning. Oxidation yielded an increased mobility of all metals apart from cadmium. The ratio of the simultaneously extracted metals (SEM) and acid volatile sulfides (AVS) was found to be >1. Semi-dynamic and toxicity characteristic leaching tests were conducted to assess the effectiveness of solidification/stabilization (S/S) thermal treatment with clay and long-term leaching behavior of these metals. A diffusion-based model was used to elucidate the controlling leaching mechanisms. Applied S/S thermal treatment was effective in immobilizing metals, irrespective of their different availability in the untreated samples. The controlling leaching mechanism appeared to be diffusion.

A comparison of sediment quality results with acid volatile sulfide (AVS) and simultaneously extracted metals (SEM) ratio in Vojvodina (Serbia) sediments.

The acid-volatile sulfide (AVS), simultaneously extracted metals (SEM), total metals, and pore-water metal concentrations were studied in Vojvodina (Serbia) sediments. In Serbia, there are no regulations concerning sediment quality standards and sediment management. Harmonization of legislation in the domain of environmental protection with EU requirements will increase the significance of the sediment issue. Sediment quality was assessed according to Dutch standards, but the results were also compared with Canadian and USEPA (United States Environmental Protection Agency) guidelines for sediment quality. A comparison of the results based on different criteria for sediment quality assessment shows that they are sometimes contradictory. Therefore, a single approach to quality assessment may be insufficient. The Sigma[SEM]/[AVS] ratio was found to be greater than one at several locations that were already recognized as places of high risk based on Dutch standards. Some other samples had Sigma[SEM]/[AVS]<1, despite of the high risk classification based on the Dutch evaluation. However, not all sediments with Sigma[SEM]/[AVS]>1 can cause increased toxicity because there are many other metal-binding phases in sediments. Metals that are associated with AVS may be released within sediments through storms, dredging activities, oxidation, etc., and may have adverse environmental impacts. This has to be taken into account during dredging, which is for some sediments necessary because the sediment is of class 4 (Dutch evaluation), because the dredging process will certainly increase the concentration of bioavailable heavy metals and disturb the sedimentation dynamics. The obtained results will be invaluable for future activities regarding dredging and sediment management in the country.

Pollution of the Begej Canal sediment--metals, radioactivity and toxicity assessment.

The Begej Canal is one among a large number of canals in Vojvodina (Northern Province of Serbia and Montenegro). The paper describes a study of metal and radioactivity contamination of the Begej Canal sediment. It is also concerned with the evaluation of sediment acute toxicity based on standard test species Daphnia magna and simultaneously extracted metals and acid volatile sulfides. The quality of sediment was assessed according to Dutch standards, but the results were also compared with some Canadian and USEPA (United States Environmental Protection Agency) guidelines for sediment quality. The results showed severe pollution with chromium, copper, cadmium and zinc, whereby the anthropogenic origin of these contaminants was indicated. The tests of toxicity of sediment pore water to D. magna, gave no indication of the presence of substances in acutely toxic concentrations to this species. It can be speculated that, despite of high metal contents, the observed toxicity was low because of the high contents of clay and iron, as well as sulphide. Also, based on a comparison with the Danube sediment and Vojvodina soil in general, the data of the Begej sediment contamination with 238U and 137Cs. The 137Cs data were used for approximate dating of the sediment. No traces of contamination by nuclear power plants in the region were found, while the presence of technologically enhanced naturally occurring radioactive materials (TENORM) was proved. Conclusions based on different criteria for sediment quality assessment were in some cases contradictory. Study also showed that radioactivity aspects can be useful in sediment quality surveys. The obtained results will be invaluable for the future activities regarding integrated water management based on EC Water Framework Directive (2000/60/EC) in the Danube basin, and particularly in the region of crossborder water body of the Begej Canal.

Duodenal obstruction from chronic pancreatitis.

The fibrosclerosing process of the pancreas in the chronic pancreatitis may constrict not only the pancreatic duct but also the bile duct, splenoportal venous system and duodenum. In our retrospective study we analysed 24 patients with duodenal obstruction associated with chronic pancreatitis. Duodenal obstruction was suspected whenever repeated vomiting occurred or large volumes of nasogastric aspirate were obtained. The diagnosis was confirmed by barium meal and endoscopic examination. Duodenal obstruction was relieved by gastrojejunostomy in eight patients, gastrojejunostomy and vagotomy in eight patients, gastroduodenostomy and vagotomy in two patients, vagotomy with Finney pyloroplasty in one patient, duodenoplasty with vagotomy in one patient and Whipple procedure in four patients. We concluded that vagotomy and gastroenterostomy are the procedures of choice. Bypass surgery is helpful to relieve the obstruction of the common bile duct and pancreatic duct. Whipple procedure should be reserved for the small duct form of chronic pancreatitis and for the cases in which there is high suspicion of malignancy.

[Liver cirrhosis caused by alpha-1-antitrypsin deficiency]. / Ciroza jetre uzrokovana deficitom alfa-1-antitripsina.

The authors present 2 patients with cirrhosis of the liver associated with alpha-1-antitrypsin deficiency. The patients are two children (brother and sister aged 4 and 13). The manifestation of the disease in these two children was a prolonged neonatal icterus. The symptoms of a decompensated cirrhosis of the liver appeared at the age of 2 and 4 years. There were several attacks of obstructive bronchitis etiologically associated with the same cause. The boy died at the age of four of hepatic coma preceded by several bleedings from esophageal varices. Splenectomy was performed in the girl on account of distinct signs of hyperplenism and two and a half years later mesentericocaval shunt because of the extensive bleeding from esophageal varices and the fundus of the stomach. The diagnosis of alpha-1-antitrypsin deficiency was made on the basis of low values in the serum and on the basis of liver biopsö and findings of typical PAS positive inclusions in the endoplasmic reticulum of hepatocytes. The values of A1A parents are also lower. The finding of Pi phenotypification is significant--the SZ phenotype was found in two patients (brother and sister), which is seldom described in patients with cirrhosis of the liver.