Oxalate: its role in lithogenesis and composition of calcium oxalate lithiasis

A prospective study was conducted on 374 patients with urinary lithiasis, aiming to analyze the participation of oxalate in the lithogenesis and composition of the calcium oxalate calculi, alone or associated to other factors. METHODOLOGY: Metabolic urinary study of the patient and analysis of calculi with infrared spectrography and optical microscopy. RESULTS: 26.3% patients had hyperoxaluria and 77.5% of the calculi contain calcium oxalate; these are 167 cases of calcium oxalate, 110 of oxalate and calcium phosphate and 13 cases of mixed calcium oxalate and uric acid lithiasis. 43.4% patients with pure monohydrate calcium oxalate calculi have hypercalciuria, 22.6% hyperoxaluria and 19% hyperuricosuria. Dihydrated calcium oxalate calculi are related to high hypercalciuria in 65% cases and to significant hyperoxaluria in 35% cases. 45% patients present a single lithogenic factor, either hypercalciuria (49.6%), hyperoxaluria (20.6%), hyperuricosuria (13.74%), hypocitraturia (9%), urinary infection (1.5%), A.T.R. (2.25%) or acid oliguria (3%).     

The electrochemical reduction of nitrosonium ion in concentrated sulphuric acid: The NO/NO redox couple

The electrochemical reduction of NO⁺ ion in concentrated sulphuric acid has been studied on gold and platinum electrodes in the temperature range from 4·5 to 55·5°C with the rotating disk electrode, linear potential-sweep voltammetry and chronopotentiometry. On gold, NO⁺ is reduced to NO, the reaction being a reversible one-electron transfer reaction. The experimental diffusion coefficients of the NO⁺ ion and NO molecule are evaluated. On platinum, in the potential region where reduction of NO⁺ ion and oxidation of NO occur, oxides formed on the metal interfere, thus making the interpretation of the process difficult.     

Determinants of internal and external R&D offshoring: evidence from Spanish firms

This paper analyses the determinants of R&D offshoring of Spanish firms using information from the Panel of Technological Innovation. We find that being an exporter, international technological cooperation, continuous R&D engagement, applying for patents, being a foreign subsidiary, and firm size are factors that positively affect the decision to offshore R&D. In addition, we find that a lack of financing is an obstacle relatively more important for independent firms than for firms that belong to business groups. For these latter, we also obtain that the factors that influence the decision to offshore R&D differ depending on whether the firm purchases the R&D services within the group or through the market: a higher degree of importance assigned to internal sources of information for innovation as compared to market sources increases (decreases) the probability of R&D offshoring only through the group (market).     

Industrial implementation of controller performance analysis technology

In this paper, a controller performance monitoring technology is introduced with a focus on its industrial implementation and applications. The technology to be introduced in this paper is known as Performance Analysis Toolbox and Solutions (PATS). The main components are discussed, which include data collection, closed-loop systems identification, control valve stiction monitoring, univariate control performance monitoring, multivariate control performance monitoring, model predictive control performance monitoring, etc. It is shown, through a thorough industry case study with various components of PATS, that the integration of the technology provides more convincing diagnosis results and facilitates identification of control improvement opportunities. Some components of the developed technology can be downloaded from the website http://www.ualberta.ca/～bhuang/research/research.htm.     

New chemosensors based on thiomacrocycle-containing coumarin-343 fluoroionophor: X-ray structures and previous results on the effect of cation binding on the photophysical properties

Two new emissive chemosensors based on coumarin-343 have been synthesized, and their photophysical studies conducted. L1 contains an aza-thio macrocycle ring as the chelating unit, which has great affinity for soft metal ions, whereas L2 is a parent species without macrocyclic unit. Both compounds were separated by column chromatography and characterized by elemental analysis, ¹H,¹³C NMR, UV–vis and FAB mass spectroscopy. The X-ray structures of L1 and L2 and the supramolecular interactions in the solid state are discussed. Preliminary results on the metal–ion sensing effects of the ligands are presented. Titrations with Ag⁺, Pd²⁺ and Ni²⁺ have been studied by UV–vis absorption and fluorescence spectroscopy.     

Gene expression during activation of Paracoccidioides brasiliensis conidia

This study focuses on gene expression during crucial biological phenomena of the dimorphic fungal human pathogen Paracoccidioides brasiliensis, the conidia‐to‐yeast (C‐Y) transition and the conidia‐to‐mycelia (C‐M) germination. We studied 10 genes involved in different cellular functions: oxidative stress response (alternative oxidase (AOX), superoxide dismutase (SOD), flavodoxin, conserved hypothetical protein (Y20)); cell metabolism (glyceraldehyde‐3‐phosphate dehydrogenase (GADPH), cholestenol Delta‐isomerase (ChDI), glycine dehydrogenase (GDh)) and heat shock response (Heat shock protein 90 (HSP90)), and cell synthesis and wall structure (glucan synthase‐1 (GS‐1), α‐1,3‐glucan synthase (αGS), and mannosyltransferase (MT)). Gene expression was measured during the first 72 h and 96 h of C‐Y and C‐M, respectively, previously shown to be a fundamental time frame for the consolidation of these cellular processes. The gene expression of AOX, GAPDH, HSP90, MT, αGS, and GDh was significantly increased during the C‐Y transition, while SOD, ChDI, GAPDH, MT, GDh, and GS‐1 were increased during C‐M germination. Additionally, some were highly expressed in each process: AOX, HSP90, and αGS during C‐Y; SOD, ChDI, and GS‐1 during C‐M. Altogether, these data add new information regarding gene expression during the C‐Y and C‐M processes. Future research will be targeted to further characterize the true relevance of the studied genes during the morphological transition, either during adaptation to the environment or to the infected host. Copyright © 2011 John Wiley & Sons, Ltd.