Potassium Bicarbonate (potassium + bicarbonate)

Distribution by Scientific Domains


Selected Abstracts


Novel method for clearing red blood cell debris from BacT/ALERT® blood culture medium for improved microscopic and antimycobacterial drug susceptibility test results

JOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 4 2007
Krishnamoorthy Gopinath
Abstract Even though automation in mycobacterial culture has immensely improved the detection of organisms, identification of species and antimycobacterial susceptibility testing from blood culture bottles remain cumbersome and error-prone due to the presence of intact red blood cells (RBCs). The removal or lysis of these RBCs and excessive protein from the blood components could theoretically help improve this process. The present study reports an effective method that uses ammonium chloride (NH4Cl) and Triton X-100 to lyse the RBCs in blood culture medium. The method was optimized by preparing various concentrations of NH4Cl and Triton X-100, and incubation conditions, leading to eight protocols. The lysis protocol with a concentration of 150,mM of NH4Cl, 0.5% Triton X-100, and 1% potassium bicarbonate, pH 7.0, and incubation at 37°C for 15,min was found to be optimal. This method not only made the culture medium clear, the protein concentration decreased from 753.5±39.4 to 53.2±4.2,mg/mL in the M. tuberculosis -spiked culture medium and in the blood culture medium inoculated with the blood from tuberculosis patients. The method had no adverse effect on mycobacteria, and no depletion of M. tuberculosis colony-forming units was found. The lysate could be used for antimycobacterial susceptibility testing with no difficulty in setting the mycobacterial concentration of inoculum to 0.5 McFarland standards. Furthermore, this method had the added advantage in the microscopy and molecular methods for the speciation of Mycobacterium sp. J. Clin. Lab. Anal. 21:220,226, 2007. © 2007 Wiley-Liss, Inc. [source]


Substitution-reduction: an alternative process for the [18F]N -(2-fluoroethylation) of anilines

JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 4 2004
Emmanuelle Briard
Abstract Substitution of a halo atom (chloro or bromo) in easily prepared N -haloacetyl-anilines with no-carrier added (NCA) cyclotron-produced [18F]fluoride ion (18F, t1/2= 109.8 min; ,+=96.9%), followed by reduction with borane,tetrahydrofuran (BH3,THF), provides an alternative route to NCA [18F]N -(2-fluoroethyl)-anilines. This two-step and one-pot process is rapid (,50 min) and moderately high yielding (,40% decay-corrected radiochemical yield (RCY) overall). In the nucleophilic substitution reaction, 18-crown-6 is preferred to Kryptofix® 222 as complexing agent for the solubilization of the counter-ion (K+), derived from an added metal salt, in acetonitrile. Weakly basic potassium bicarbonate is preferred as the added metal salt. Inclusion of a small amount of water, equating to 4,5 molar equivalents relative to 18-crown-6, base or precursor (held in equimolar ratio), is beneficial in preventing the adsorption of radioactivity onto the wall of the glass reaction vessel and for achieving high RCY in the nucleophilic substitution reaction. BH3,THF is effective for the rapid reduction of the generated [18F]N -fluoroacetyl-aniline to the [18F]N -(2-fluoroethyl)-aniline. Copyright © 2004 John Wiley & Sons, Ltd. [source]


An evaluation of biological and abiotic controls for grapevine powdery mildew.

AUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 3 2006

Abstract Grapevine powdery mildew, caused by the fungus Erysiphe necator, is a major disease affecting grape yield and quality world-wide. In conventionally-managed vineyards, this disease is controlled mainly by regular application of sulfur and synthetic fungicides; and in organic agriculture, by sulfur and canola-based oils. Health and environmental impacts associated with the use of sulfur, development of resistance to certain synthetic fungicides, and demand for residue-free grapes, all point to a need for effective alternatives to sulfur and synthetic chemicals. Accordingly, seven greenhouse experiments were conducted to evaluate the potential of novel (abiotic) materials, as well as certain biological agents, for controlling powdery mildew. Application of Bacillus subtilis, milk (200 mL/L), whey (30 g/L), canola-based oils (2,4 mL/L) and Ecocarb (potassium bicarbonate, 3 g/L) all reduced the severity of powdery mildew, and in some cases by 96% compared with untreated controls. Such treatments thus offer potential as alternatives to sulfur in organic viticulture if their efficacy can be duplicated under field conditions , the subject of paper 2 in this series (Crisp et al. 2006, Australian Journal of Grape and Wine Research12, pp. 203,211). [source]


An evaluation of biological and abiotic controls for grapevine powdery mildew.

AUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 3 2006

Abstract Grapevine powdery mildew (Erysiphe necator) affects grape yield and fruit quality worldwide. Managers of conventional vineyards rely mainly on synthetic fungicides and sulfur to control powdery mildew, while in organic vineyards sulfur is the main control agent, often in rotation with canola-based oils, bicarbonates and biological control agents. The efficacy of those materials has not been evaluated critically under field conditions in Australia. Accordingly, a range of materials showing most promise in previous greenhouse trials (Crisp et al. 2006 Australian Journal of Grape and Wine Research12, pp. 192,202) were assessed via field trials in commercial vineyards. Applications of either milk or whey (alone, or mixed with a canola oil-based product), as well as applications of potassium bicarbonate (commercial formulation), all reduced the severity of powdery mildew compared with untreated vines. Eight applications of a 1:10 dilution of milk, 45 g/L whey powder or programs comprising rotations of potassium bicarbonate plus oil and whey, applied at 10,14 day intervals, reduced the severity of powdery mildew to levels not significantly different from that on vines sprayed with sulfur (wettable powder, 3,6 g/L). However, the relative control of powdery mildew by the test materials in field trials was dependent on the susceptibility of the grapevine cultivar and the extent of spray coverage achieved. In vineyards where highly susceptible cultivars were planted, and spray coverage was compromised, the resultant control of powdery mildew was reduced; and sometimes to commercially unacceptable levels. [source]