Upgrading Pyrolytic Residue from End-of-Life Tires to Efficient Heterogeneous Catalysts for the Conversion of Glycerol to Acetins.

Recovered carbon blacks (rCBs) produced from end-of-life tires using pyrolysis were transformed into solid acid catalysts for the synthesis of acetins, i.e., products with a wide spectrum of practical applications. Tuning the chemical properties of the surface of samples and introducing specific functional groups on the rCBs were achieved through carbon functionalization with concentrated H2SO4. The initial and modified rCBs were thoroughly characterized using techniques such as elemental analysis, potentiometric back titration, thermogravimetric technique, scanning and transmission microscopy, X-ray photoelectron spectroscopy, etc. The catalytic activities of the samples were measured via batch mode glycerol acetylation performed at 110 °C and compared to the catalytic performance of the functionalized commercial carbon black. The modified rCBs were found to show a significant catalytic effect in the tested reaction, giving high glycerol conversions (above 95%) and satisfactory combined yields of diacetins and triacetin (~72%) within 4 h; this behavior was attributed to the presence of -SO3H moieties on the surface of functionalized rCBs. The reusability tests indicated that the modified samples were catalytically stable in subsequent acetylation runs. The obtained results evidenced the feasibility of using end-of-life tires for the production of effective acid catalysts for glycerol valorization processes.

Modelling of Resinous Material Filling Expansion Joints in Reinforced Concrete Structures.

This paper is a continuation of the research and analysis to estimate hyperelastic material constants when only uniaxial test data are available. The FEM simulation was expanded and the results obtained from three-dimensional and plane strain expansion joint models were compared and discussed. The original tests were carried out for a gap with a width of 10 mm, whereas in the case of axial stretching, the stresses and internal forces caused by the leading deformations were recorded for a smaller gap, and the axial compression was also recorded. The differences in the global response between the three- and two-dimensional models were also considered. Finally, using FEM simulations, the values of stresses and cross-sectional forces in the filling material were determined, which can be the basis for the design of expansion joints geometry. The results of these analyses could form the basis of guidelines for the design of expansion joint gaps filled with material, ensuring the waterproofing of the joint.

Assessment of the Mechanical Properties of ESD Pseudoplastic Resins for Joints in Working Elements of Concrete Structures.

Concrete structure joints are filled in mainly in the course of sealing works ensuring protection against the influence of water. This paper presents the methodology of testing the mechanical properties of ESD pseudoplastic resins (E-elastic deformation, S-strengthening control, D-deflection control) recommended for concrete structure joint fillers. The existing standards and papers concerning quasi-brittle cement composites do not provide an adequate point of reference for the tested resins. The lack of a standardised testing method hampers the development of materials universally used in expansion joint fillers in reinforced concrete structures as well as the assessment of their properties and durability. An assessment of the obtained results by reference to the reference sample has been suggested in the article. A test stand and a method of assessing the mechanical properties results (including adhesion to concrete surface) of pseudoplastic resins in the axial tensile test have been presented.

Antihypertensive treatment prescription in pediatric dialysis patients in Poland: A comparison between two nationwide studies 2003/2004-2013.

BACKGROUND: Blood pressure in pediatric dialyzed patients is under poor control. OBJECTIVES: The aim of the study was to assess the strategy and efficacy of antihypertensive drugs used for the treatment of hypertension in pediatric dialyzed patients in 2013 in comparison with the data collected in 2003/2004. The results have been viewed against present strategies of antihypertensive treatment in children. There is still limited data concerning the treatment of hypertension in dialyzed pediatric patients. MATERIAL AND METHODS: The study embraced 10 of 12 pediatric dialysis units in Poland treating 59 pediatric patients (mean age - 132 months). Collected information included present antihypertensive treatment with regard to drug classes and the dose of antihypertensive agent. The treatment was regarded as effective if both systolic and diastolic values of blood pressure were below 1.64 SDS. The results from 2013 were juxtaposed with previously analyzed data from a similar study on hypertension in dialyzed children conducted in 2003/2004. RESULTS: Forty subjects have been provided with antihypertensive treatment. In monotherapy and polytherapy 50% of the subjects were treated with ACEI (enalapril and ramipril), 67.5% with amlodipine, 50% with beta-blockers. Only 10% of the subjects were treated with angiotensin II receptor blocker (losartan). Thirty percent of the subjects received furosemide, whereas 5% were given doxazosin. Antihypertensive drugs regarded as the 2nd and 3rd choice in treating high blood pressure (doxazosin, beta-blockers and furosemide) were applied as monotherapy in 46% of the patients. Satisfactory control of treated blood pressure was reached in 45% of them. CONCLUSIONS: Antihypertensive treatment in dialyzed children did not change significantly during the last decade with regard to the groups of drugs being used. Despite a wider feasibility of antihypertensive substances, the effectiveness of this therapy was still unsatisfactory.

When "diabetic nephropathy" is not always of diabetic origin: a case report.

The etiology and pathogenesis of fibrillary glomerulonephritis (FGN) remains unknown. The presented case shows an extremely rare FGN in association with commonly diagnosed diabetes. A 74-year-old, non-smoking, obese and diabetic woman was hospitalized due to a progressive and accelerated decrease in the renal function. The primary cause of chronic kidney disease was believed to be of diabetic origin. In the renal biopsy, light microscopy showed glomerular changes resembling diabetic nephropathy, however electron microscopy evaluation revealed linear, randomly arranged fibrils present in the glomerular mesangium and in peripheral capillary loops. The biopsy confirmed fibrillary glomerulopathy.

A decrease in the cellular phosphodiester to phosphomonoester lipid ratio is characteristic of HIV-1 infection.

The ability to detect HIV-1 in tissues that are not readily amenable to biopsy greatly limits the diagnosis and control of HIV infection, and ultimately, our ability to understand HIV-induced disease pathology. In view of this, we explored the utility of diagnostically measuring HIV-1 infection using (31)P nuclear magnetic resonance ((31)P-NMR). (31)P-NMR enables the correlation of infection to changes in the concentration of specific intracellular metabolites, macromolecules and of bioenergetic parameters that are key to mammalian cell physiology. Examples include primary components of biological membranes such as phosphomonoester (PME) and phosphodiester (PDE) lipids. Using (31)P-NMR we found that changes in the ratio of PDE/PME in human cell lines and primary isolates were significantly altered following HIV-1 infection. Our findings showed that the ratio of cellular PDE/PME uniformly decreased 2.00-2.26 fold in HIV-1 infected cells. Using the altered PDE/PME ratio as a selection criterion, we next assessed HIV-1 infection in lymphocytes isolated from both HIV-1 seropositive and non-infected human subjects. A decreased PDE/PME ratio was characteristic of HIV-1 infection in each instance. These results demonstrate that changes in cellular phospholipids induced during HIV-1 infection may be used to uncover basic mechanisms of HIV-1 pathology, and potentially, may be extrapolated to explore the application of NMR analysis as a technique for imaging infected organs and tissues in situ.

The effect of uremia and hemodialysis on caspase-1 and caspase-3 activity in neutrophils.

BACKGROUND: Neutrophils in uremia maintain chronic inflammation, which contributes to malnutrition and immunity disorders. The influence of hemodialysis on the life span of neutrophils is unclear, although many authors postulate its apoptotic effect. Erythropoietin (EPO) is an antiapoptotic factor for various cells. We investigated factors possibly interfering in apoptosis of neutrophils in hemodialysis (HD) patients, such as HD session, parathormone (PTH), dose of EPO, inflammation and nutrition. SUBJECTS AND METHODS: Twenty HD patients and ten healthy controls were donors of neutrophils. We evaluated caspase-1 and caspase-3 activities, related to apoptosis of neutrophils, before and after a 4-hour HD session with cuprophane or polysulphone dialyzer. We measured serum concentrations of C-reactive protein, cholesterol, albumin, prealbumin and transferrin. Time of dialysis treatment, PTH level and dose of EPO were also evaluated. RESULTS: We observed a significant increase in caspase-1 activity and decrease in caspase-3 activity in neutrophils after HD with cuprophane, but not with polysulphone. Caspase-1 activity correlated positively with EPO dose and negatively with PTH level. Caspase-3 correlated negatively with the time of dialysis treatment. No correlation between caspase activity and markers of inflammation or nutrition was noticed. CONCLUSIONS: The results suggest that HD with bioincompatible cuprophane may prolong the life span of neutrophils due to the intense inflammatory reaction and high activity of caspase-1. Time of dialysis treatment, PTH level and EPO dose potentially influence the life span of neutrophils. PTH seems to have a proapoptotic effect of neutrophils, while EPO is an antiapoptotic factor.

[Can the administration of large doses of vitamin C have a harmful effect?]. / Czy stosowanie duzych dawek witaminy C moze byc szkodliwe?

Vitamin C in its pure form or as a component of multivitamin and combined drugs belongs to the over-the-counter drugs that are available not only at the chemist's but in retail shops as well. Intensive promotion of the advantages of vitamin C as the compound that augments immunity to all sorts of infections, accelerates recovery, eliminates the symptoms of common cold and flu-like diseases, and contributes to general well-being, is of great importance to its intake in quantities far exceeding the recommended dietary allowance. Moreover, the subjects who simultaneously take several anti-common cold drugs are not aware of the fact that almost each of them contains ascorbic acid. Among numerous reports concerning positive effect of vitamin C as antioxidant and free radicals scavenger, there are also those pointing at its potentially pernicious effect. Vitamin C, especially in the doses exceeding daily recommended dietary allowance may result in oxalate crystallization, formation of advanced glycation end products and even exert prooxidant effect.

The role of carbonic anhydrase in the recovery of skeletal muscle from anoxia.

To investigate the role of carbonic anhydrase in the recovery of skeletal muscle from anoxia, pH and cell phosphates were measured by (31)P-nuclear magnetic resonance in superfused newborn rabbit myotubes and cultured mouse soleus cells (H-2K(b)-ts a58) after approximately 2-3.5 h without superfusion. In control studies, pH and phosphocreatine fell and P(i) rose during anoxia and recovered within <10 min after reperfusion began. A carbonic anhydrase inhibitor, acetazolamide, and dimethylamiloride, an inhibitor of the Na(+)/H(+) antiporter NHE1, delayed the recoveries of pH, phosphocreatine, and P(i) for >10 min, but the rate of recovery, once initiated, was unchanged. In the presence of the inhibitors, after reperfusion started, the pH did not rise immediately, despite a large inwardly directed HCO(3)(-) gradient, suggesting that HCO(3)(-) movement was unimportant in acid elimination. Lactate, measured by its methyl protons, rose during anoxia and did not fall after 1 h of reperfusion and could not have eliminated protons by cotransport. We conclude that NHE1 is the major exporter of protons by skeletal muscle in recovery from a period of anoxia and that it is essential for functioning carbonic anhydrase to be attached to NHE1 to activate it. The mechanism of late recovery of pH could be the mobilization of another proton transporter or removal of the inhibition of the Na(+)/H(+) antiporter. Inhibition of carbonic anhydrase in skeletal muscle retards acid removal and modifies muscle metabolism significantly after anoxia.