Theoretical and experimental investigation of the influence of intraphase diffusion on the oxidation of toluene over manganese-based oxide.

The influence of intraphase diffusion on the oxidation of toluene over manganese-based oxide, MnFeOx, under isothermal conditions was investigated. The one-dimensional (1D) heterogeneous model was developed to explain the experimental results. The model can be applied under certain operating conditions, i.e. conditions with negligible resistance to external mass transfer. The article describes the numerical solution of the equations of the proposed model. The relevance of the 1D heterogeneous model compared to the 1D pseudohomogeneous model was also emphasized. Validation of the proposed models was carried out by comparing with experimentally measured results. Both models were found to describe the experimental system studied quite well, with the 1D heterogeneous model providing better insight into the relationship between the rate of chemical reaction and the rate of intraphase diffusion.

Therapy of nonalcoholic fatty liver disease: current status.

Nonalcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome, has become a common entity in clinical practice. In most of the patients it presents as simple steatosis with nonprogressive clinical course. However, some patients have progressive form of NAFLD, nonalcoholic steatohepatitis (NASH), and are at increased risk of developing cirrhosis and hepatocellular carcinoma. NAFLD treatment includes lifestyle modifications and pharmacotherapy aiming at increasing insulin sensitivity, and attenuating inflammation and hepatic fibrosis. Weight reduction has consistently been shown to reduce levels of liver enzymes and insulin resistance. Although dietary intervention and exercise remain the first-line therapy, due to low patients compliance to these measures pharmacotherapy or surgical approaches are often required. Metformin and thiazolidinediones may improve insulin sensitivity, serum aminotransferase level and liver histology. However, little evidence exists regarding their sustained effects after drug discontinuation which, together with their side effects, limits their widespread use in clinical practice. Statins appear to be safe agents for the treatment of hyperlipidemia, although trials documenting their efficacy in NAFLD are scarce. Based on the recent clinical trials, weight loss medication orlistat, ursodeoxycholic acid and antioxidant agents could potentially be used as adjunctive therapy. Considering still largely controversial clinical data regarding pharmacological agents, their high cost and known side-effects, lifestyle modifications at present remain the only essential considerations in the NAFLD treatment.

Pericarditis in exacerbation of ulcerative colitis.

Acute pericarditis occurs very rarely in association with inflammatory bowel disease (IBD). It has been described both as an extraintestinal manifestation of IBD and as an adverse drug reaction in IBD treatment. We present a case of a 26-year-old female patient with a severe exacerbation of ulcerative colitis, who was previously under long-term treatment with mesalazine and low-dose prednisone. The literature on pericardial involvement in IBD is reviewed.

Interactions in mixed cationic surfactants and dextran sulfate aqueous solutions.

The interactions between a hydrophilic anionic polysaccharide, dextran sulfate, and oppositely charged surfactants, n-alkylammonium chlorides (the number of carbon atoms per chain being 10, 12, and 14), were investigated by optical microscopy, X-ray diffraction, microelectrophoretic mobility, conductivity, surface tension, and light-scattering measurements at 303 K. The increase of surfactant alkyl chain length shifts both the critical aggregation (cac) and the critical micelle concentrations (cmc) toward lower surfactant concentration. Light-scattering and microelectrophoretic data revealed the coexistence of differently structured complexes beyond the cac. The presence of giant vesicles indicates that at least one type of species is ordered in bilayers. X-ray analysis of dry n-alkylammonium dextran sulfates exhibited mesomorphous ordering and interplanar spacings typical for lamellar structures; i.e., n-alkylammonium molecules form more or less disordered bilayers interconnected with dextran sulfate chains, thus forming multilamellar stacks. The average basic lamellar thickness increased linearly with the increase of surfactant chain length, whereas the average number of lamellar bilayers in the stack of lamellae decreases.

Physicochemical Properties of Dodecylammonium Picrate.

A novel surfactant, dodecylammonium picrate (DDAP), was synthesized and its crystal structure was determined by X-ray diffraction analysis. DDAP's physicochemical properties were examined by spectral (infrared and nuclear magnetic resonance), thermal, microscopic, and conductometric studies. The results revealed the influence of counterion specificity on thermal solid-state transitions and solution properties: the Krafft point, the aqueous solubility, the critical micelle concentration, the degree of counterion binding, and thermodynamic parameters of micellization. Copyright 2000 Academic Press.

Solid State Transitions of Asymmetric Catanionic Surfactants.

A series of asymmetric surfactants were prepared from cationic surfactant, hexadecyltrimethylammonium bromide, and anionic surfactant, sodium alkyl sulfate (the number of carbon atoms per chain being 10, 12, or 14). The influence of the alkyl chain asymmetry on the thermal properties of formed hexadecyltrimethylammonium alkyl sulfates was investigated by means of polarizing microscopy, differential scanning calorimetry, and X-ray diffraction. Asymmetric catanionic surfactants exhibited a complex polymorphism and thermotropic mesomorphism from the stable crystalline form to the isotropic phase. On heating, successive phase transitions (several solid crystalline-solid crystalline, solid crystalline-liquid crystalline, and liquid crystalline-isotropic liquid) were observed. The number of polymorphs, in all of the bilayered structure, depended on the asymmetry between the lengths of surfactant tails. The basic lamellar thickness varied linearly with the increase of alkyl sulfate chain length. An increase of the basic lamellar thickness with temperature was determined. Polarizing microscopy revealed a characteristic texture of the smectic phase. On cooling, all compounds underwent reversibly the isotropic liquid-liquid crystalline transitions, while crystallization from melted samples was kinetically controlled. Copyright 1999 Academic Press.

Glaucoma simplex congenitum in the Veli Brgud village, the Opatija County, Republic of Croatia--a genealogical nine-generation study.

On the Ucka hill-side, in the Veli Brgud village, Opatija County, Istrian peninsula, Republic of Croatia, there is a great number of patients with glaucoma simplex congenitum (open angle glaucoma) among a total of 550 Croatian inhabitants. Of these, 536 (97.5%) were ophthalmologically examined and glaucoma simplex congenitum was diagnosed in 74 persons, some of them already blind. The proportion of the affected was 13.8%. The cases were largely from the Afric family (nicknamed "Sor"). The pedigree of the Afric-"Sor" family has 1215 members through nine generations, descendants of Matheus Afric (1762) and Marija Bratovic (1765). In the total of 536 examined, 291 (54%) belong to this pedigree, whereas 67 (90%) out of 74 affected persons were of the same pedigree. The rest of 7 (9.46%) affected patients did not descend from this pedigree, however, three of them (4.05%) were also from the Afric-"Sor" family, but we could not find a connection with that pedigree due to inadeguate marital data before 1760. In the Veli Brgud village, there also were 4 (5.41%) patients of non-Afric families with no other affected members. From the total of 330 marriages, 73 (22%) were consanguineous. According to our results, the mode of inheritance of glaucoma simplex in the Afric-"Sor" pedigree was of a dominant pattern.

[Acute erythremic myelosis as a terminal phase of polycythemia rubra vera]. / Akutna eritremicna mijeloza kao terminalna faza policitemije rubre vere

A male, 66, developed Acute Erythremic Myelosis in the course of Polycythemia Vera. The time of onset of Polycythemia Vera could not be determined, his first symptoms being vascular complications. He received treatment with Phlebotomies and Myleran. Five years later he became ill with malaise, fever, splenomegaly; in the peripheral blood profound pancytopoenia with immature, bizzare erythro-and megaloblasts have been found. Bone marrow was full of atypical megaloblasts, some of them having two or more nuclei. The number of mitoses was increased. Chromosomal abnormalities consisted of ane-uploid cells, chromatid breakes and translocations (G to A-1). The therapy with B12, Cytosin-Arabinoside, Oncovin and Blood transfusions was unsuccessful. He died 21 days after being admitted to the Hospital.