ABSTRACT
Due to the need of sustainable energy sources, methane dry reforming is a useful reaction for conversion of the greenhouse gases CH4 and CO2 to synthesis gas (CO + H2). Syngas is the basis for a wide range of commodity chemicals and can be utilized for fuel production via Fischer-Tropsch synthesis. The current study focuses on spectroscopic investigations of the surface and reaction properties of a ZrO2/Pt inverse model catalyst, i.e. ZrO2 particles (islands) grown on a Pt(1 1 1) single crystal, with emphasis on in situ near ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) during MDR reaction. In comparison to technological systems, model catalysts facilitate characterization of the surface (oxidation) state, surface adsorbates, and the role of the metal-support interface. Using XPS and infrared reflection absorption spectroscopy we demonstrated that under reducing conditions (UHV or CH4) the ZrO2 particles transformed to an ultrathin ZrO2 film that started to cover (wet) the Pt surface in an SMSI-like fashion, paralleled by a decrease in surface/interface oxygen. In contrast, (more oxidizing) dry reforming conditions with a 1:1 ratio of CH4 and CO2 were stabilizing the ZrO2 particles on the model catalyst surface (or were even reversing the strong metal support interaction (SMSI) effect), as revealed by in situ XPS. Carbon deposits resulting from CH4 dissociation were easily removed by CO2 or by switching to dry reforming conditions (673-873 K). Thus, at these temperatures the active Pt surface remained free of carbon deposits, also preserving the ZrO2/Pt interface.
ABSTRACT
Determination of CHE has already been proven as a useful test in the diagnosis of liver diseases. Our investigation included 2 groups of patients: a group suffering from parenchym hepatitis caused by virus infection A and B, and a second group of patients suffering from etiologically different obstructive hepatitis (malign and benign obstruction). Our tests show that there is lower CHE activity in patients with hepatitis B. There is a remarkable difference of CHE activity in benign and malign obstructive hepatitis.
Subject(s)
Biliary Tract Diseases/diagnosis , Biliary Tract Diseases/enzymology , Cholinesterases/blood , Jaundice/enzymology , Jaundice/etiology , Acute Disease , Adult , Bile Duct Neoplasms/diagnosis , Bile Duct Neoplasms/enzymology , Biliary Tract Diseases/complications , Cholinesterases/metabolism , Diagnosis, Differential , Female , Hepatitis A/diagnosis , Hepatitis A/enzymology , Hepatitis B/diagnosis , Hepatitis B/enzymology , Humans , Liver Function Tests , Male , Middle Aged , Pancreatic Neoplasms/diagnosis , Pancreatic Neoplasms/enzymologyABSTRACT
We have been determining the GGT IE isoenzyme in patients with hepatitis A and B with decomposed liver cirrhosis, with obstructive hepatitis caused by the gall stones. In patients with hepatitis A and B the IE is located between albumin and betaglobulin, as well as in patients with obstructive hepatitis caused by the gall stones; in the latter partly between Alpha 1 and Alpha 2 globulin. In patients with decompensated liver cirrhosis (37.7% of the patients) there was IE activity 100% in Alpha 2 globulin area; in 6.25% of patients the activity was in the prealbumin area. In patients with secondary liver tumors we got a rather high increase of the GGT IE activity in Alpha 1 globulin area, in 77.7% of the patients even 80 to 100%. In some patients with disease progression we noticed the GGT IE activity in Beta globulin area. The results in primary liver malignomas were different. In 68.5% of the patients the GGT IE activity dominated in Alpha 1 globulin area.
Subject(s)
Bile Duct Neoplasms/enzymology , Hepatitis, Viral, Human/enzymology , Liver Cirrhosis, Biliary/enzymology , Liver Neoplasms/enzymology , gamma-Glutamyltransferase/blood , gamma-Glutamyltransferase/metabolism , Disease Progression , Female , Humans , Isoenzymes , Liver Neoplasms/secondary , MaleABSTRACT
92 patients treated for tick-borne encephalitis (TBE) in the Department for Infectious Diseases, University Hospital Osijek, over a 22-year period (1973-1995) were analysed. The patients were mostly forestry workers. The appearance of the disease followed the biological activity of the tick, with the largest number of affected individuals recorded between April and August. TBE in eastern Croatia is a relatively frequent infectious disease, appearing almost every year. In a smaller number (9.8%) of cases the clinical picture was aseptic meningitis, while in the majority of patients (90.2%) it presented as an acute meningoencephalomyelitic form. The course was relatively severe in the majority of the patients analysed, with disturbances of consciousness (32.6%) and transitory neurological signs (61.9%). Three patients died (3.3%) in the early phase of the disease. A monophasic course dominated. The clinical and epidemiological data were compared with the cases described in other parts of Croatia and regional differences were seen in the severity of illness. These variations could be due to the previously hypothesized different virus subtypes, or to some other unknown factors.
