Chemical probes that differentially modulate peroxisome proliferator-activated receptor alpha and BLTR, nuclear and cell surface receptors for leukotriene B(4).

Peroxisome proliferator-activated receptor alpha (PPARalpha)is a nuclear receptor for various fatty acids, eicosanoids, and hypolipidemic drugs. In the presence of ligand, this transcription factor increases expression of target genes that are primarily associated with lipid homeostasis. We have previously reported PPARalpha as a nuclear receptor of the inflammatory mediator leukotriene B(4) (LTB(4)) and demonstrated an anti-inflammatory function for PPARalpha in vivo (Devchand, P. R., Keller, H., Peters, J. M., Vazquez, M., Gonzalez, F. J., and Wahli, W. (1996) Nature 384, 39-43). LTB(4) also has a cell surface receptor (BLTR) that mediates proinflammatory events, such as chemotaxis and chemokinesis (Yokomizo, T., Izumi, T., Chang, K., Takuwa, Y., and Shimizu, T. (1997) Nature 387, 620-624). In this study, we report on chemical probes that differentially modulate activity of these two LTB(4) receptors. The compounds selected were originally characterized as synthetic BLTR effectors, both agonists and antagonists. Here, we evaluate the compounds as effectors of the three PPAR isotypes (alpha, beta, and gamma) by transient transfection assays and also determine whether the compounds are ligands for these nuclear receptors by coactivator-dependent receptor ligand interaction assay, a semifunctional in vitro assay. Because the compounds are PPARalpha selective, we further analyze their potency in a biological assay for the PPARalpha-mediated activity of lipid accumulation. These chemical probes will prove invaluable in dissecting processes that involve nuclear and cell surface LTB(4) receptors and also aid in drug discovery programs.

Development and validation of a gas chromatography-negative chemical ionization tandem mass spectrometry method for the determination of ethyl glucuronide in hair and its application to forensic toxicology.

Ethyl glucuronide (EtG) is a minor and direct metabolite of ethanol. EtG is incorporated into the growing hair allowing retrospective investigation of chronic alcohol abuse. In this study, we report the development and the validation of a method using gas chromatography-negative chemical ionization tandem mass spectrometry (GC-NCI-MS/MS) for the quantification of EtG in hair. EtG was extracted from about 30 mg of hair by aqueous incubation and purified by solid-phase extraction (SPE) using mixed mode extraction cartridges followed by derivation with perfluoropentanoic anhydride (PFPA). The analysis was performed in the selected reaction monitoring (SRM) mode using the transitions m/z 347-->163 (for the quantification) and m/z 347-->119 (for the identification) for EtG, and m/z 352-->163 for EtG-d(5) used as internal standard. For validation, we prepared quality controls (QC) using hair samples taken post mortem from 2 subjects with a known history of alcoholism. These samples were confirmed by a proficiency test with 7 participating laboratories. The assay linearity of EtG was confirmed over the range from 8.4 to 259.4 pg/mg hair, with a coefficient of determination (r(2)) above 0.999. The limit of detection (LOD) was estimated with 3.0 pg/mg. The lower limit of quantification (LLOQ) of the method was fixed at 8.4 pg/mg. Repeatability and intermediate precision (relative standard deviation, RSD%), tested at 4 QC levels, were less than 13.2%. The analytical method was applied to several hair samples obtained from autopsy cases with a history of alcoholism and/or lesions caused by alcohol. EtG concentrations in hair ranged from 60 to 820 pg/mg hair.

Terrorisme et médecins de premier recours: le risque chimique [Terrorism and medicine of first aid: chemical risk].

Cet article décrit, à l'intention des mdéecins de rpremier recours, les principes de base d'une action de secours lors d'un attentat (ou d'un accident) chimique impliquant de nombreuses victimes intoxiquées et/ou contaminées.

Antidote treatment for cyanide poisoning with hydroxocobalamin causes bright pink discolouration and chemical-analytical interferences.

Here we report the case of a 70-year-old woman who committed suicide by cyanide poisoning. During resuscitation cares, she underwent an antidote treatment by hydroxocobalamin. Postmortem investigations showed marked bright pink discolouration of organs and fluids, and a lethal cyanide blood concentration of 43 mg/L was detected by toxicological investigation. Discolouration of hypostasis and organs has widely been studied in forensic literature. In our case, we interpreted the unusual pink coloration as the result of the presence of hydroxocobalamin. This substance is a known antidote against cyanide poisoning, indicated because of its efficiency and poor adverse effects. However, its main drawback is to interfere with measurements of many routine biochemical parameters. We have tested the potential influence of this molecule in some routine postmortem investigations. The results are discussed.

Drying rates of Rubi grapes submitted to chemical pretreatments for raisin production

The objective of this work was to determine the most appropriated chemical treatment to be used to dry grapes cv. Rubi for raisin production. Drying curves for convective drying with air at 50ºC, in a tray drier, were obtained for grapes submitted to chemical pretreatments with different concentrations of potassium carbonate and olive oil, and different dipping times, according to factorial designs. Convective drying curves were also obtained for grapes pretreated in aqueous suspensions of soybean lecithin, at varied lecithin concentrations and dipping times. Page model was adjusted to the experimental drying curves, and the calculated drying times showed that the best pretreatment consisted in dipping grapes for 2 minutes in a 5% olive oil and 6% K2CO3 emulsion, at 50ºC, which resulted in a drying time close to that of the pretreatment with 2.5% of olive oil, but with a lower consumption of this substance. In addition, the immersion of grapes in an aqueous suspension of 2% soy lecithin, at 50ºC, for 5 minutes, resulted in a total drying time slightly higher than the most effective pretreatment.

Chemical Reactions Involving Aggregates, HR-15, 1960

The discussion presented below concerns the section on "Unidentified Cement-Aggregate Reactions" in which mention is made of concrete deterioration related to argillaceous dolomitic limestone aggregates. A considerable amount of research has been conducted on carbonate aggregate-cement reactions as part of the general study on the suitability of carbonate rocks as concrete aggregate which inadvertently did not reach the authors in time to be incorporated in their paper. These reactions which occur in response to the alkaline environment of concrete are not typical alkali-aggregate reactions associated with siliceous aggregates such as opaline cherts, volcanic glasses and etc. The reactions are associated with certain carbonate aggregates whose service records indicate deleterious performance in concrete has occurred. It is my purpose to review briefly carbonate aggregate research conducted at Iowa State University and present some new data on the problem of carbonate aggregate-cement paste reactions.

Basic density and pulp yield relationship with some chemical parameters in eucalyptus trees

The objective of this work was to evaluate the use of basic density and pulp yield correlations with some chemical parameters, in order to differentiate an homogeneous eucalyptus tree population, in terms of its potential for pulp production or some other technological applications. Basic density and kraft pulp yield were determined for 120 Eucalyptus globulus trees, and the values were plotted as frequency distributions. Homogenized samples from the first and fourth density quartiles and first and fourth yield quartiles were submitted to total phenols, total sugars and methoxyl group analysis. Syringyl/guaiacyl (S/G) and syringaldehyde/vanillin (S/V) ratios were determined on the kraft lignins from wood of the same quartiles. The results show the similarity between samples from high density and low yield quartiles, both with lower S/G (3.88-4.12) and S/V (3.99-4.09) ratios and higher total phenols (13.3-14.3 g gallic acid kg-1 ). Woods from the high yield quartile are statistically distinguished from all the others because of their higher S/G (5.15) and S/V (4.98) ratios and lower total phenols (8.7 g gallic acid kg-1 ). Methoxyl group and total sugars parameters are more adequate to distinguish wood samples with lower density.

An Investigation of the Chemical Method of Determining the Cement Content of Hardened Concrete, MLR-71-01 and R-248, 1971

The Iowa State Highway Commission Laboratory is called upon to determine the cement content of hardened concrete when field problems relating to batch weights are encountered. The standard test for determining the cement content is ASTM C-85. An investigation of this method by the New Jersey State Highway Department involving duplicate samples and four cooperating laboratories produced very erratic results, however, the results obtained by this method have not been directly compared to known cement contents of concrete made with various cements and various aggregates used in Iowa.

The Deleterious Chemical Effects of Concentrated Deicing Solutions on Portland Cement Concrete, TR-480, 2008

This research project investigated the effects of concentrated brines of magnesium chloride, calcium chloride, sodium chloride, and calcium magnesium acetate on portland cement concrete. Although known to be effective at deicing and anti-icing, the deleterious effects these chemicals may have on concrete have not been well documented. As a result of this research, it was determined that there is significant evidence that magnesium chloride and calcium chloride chemically interact with hardened portland cement paste in concrete resulting in expansive cracking, increased permeability, and a significant loss in compressive strength. Although the same effects were not seen with sodium chloride brines, it was shown that sodium chloride brines have the highest rate of ingress into hardened concrete. This latter fact is significant with respect to corrosion of embedded steel. The mechanism for attack of hardened cement paste varies with deicer chemical but in general, a chemical reaction between chlorides and cement hydration products results in the dissolution of the hardened cement paste and formation of oxychloride phases, which are expansive. The chemical attack of the hardened cement paste is significantly reduced if supplementary cementitious materials are included in the concrete mixture. Both coal fly ash and ground granulated blast furnace slag were found to be effective at mitigating the chemical attack caused by the deicers tested. In the tests performed, ground granulated blast furnace slag performed better as a mitigation strategy as compared to coal fly ash. Additionally, siloxane and silane sealants were effective at slowing the ingress of deicing chemicals into the concrete and thereby reducing the observed distress. In general, the siloxane sealant appeared to be more effective than the silane, but both were effective and should be considered as a maintenance strategy.

The Deleterious Chemical Effects of Concentrated Deicing Solutions on Portland Cement Concrete, TR-480, Implementation Guide, 2008

This research project investigated the effects of concentrated brines of magnesium chloride, calcium chloride, sodium chloride, and calcium magnesium acetate on portland cement concrete. Although known to be effective at deicing and anti-icing, the deleterious effects these chemicals may have on concrete have not been well documented. As a result of this research, it was determined that there is significant evidence that magnesium chloride and calcium chloride chemically interact with hardened portland cement paste in concrete resulting in expansive cracking, increased permeability, and a significant loss in compressive strength. Although the same effects were not seen with sodium chloride brines, it was shown that sodium chloride brines have the highest rate of ingress into hardened concrete. This latter fact is significant with respect to corrosion of embedded steel. The mechanism for attack of hardened cement paste varies with deicer chemical but in general, a chemical reaction between chlorides and cement hydration products results in the dissolution of the hardened cement paste and formation of oxychloride phases, which are expansive. The chemical attack of the hardened cement paste is significantly reduced if supplementary cementitious materials are included in the concrete mixture. Both coal fly ash and ground granulated blast furnace slag were found to be effective at mitigating the chemical attack caused by the deicers tested. In the tests performed, ground granulated blast furnace slag performed better as a mitigation strategy as compared to coal fly ash. Additionally, siloxane and silane sealants were effective at slowing the ingress of deicing chemicals into the concrete and thereby reducing the observed distress. In general, the siloxane sealant appeared to be more effective than the silane, but both were effective and should be considered as a maintenance strategy.

The Deleterious Chemical Effects of Concentrated Deicing Solutions on Portland Cement Concrete, TR-480, Executive Summary, 2008

This research project investigated the effects of concentrated brines of magnesium chloride, calcium chloride, sodium chloride, and calcium magnesium acetate on portland cement concrete. Although known to be effective at deicing and anti-icing, the deleterious effects these chemicals may have on concrete have not been well documented. As a result of this research, it was determined that there is significant evidence that magnesium chloride and calcium chloride chemically interact with hardened portland cement paste in concrete resulting in expansive cracking, increased permeability, and a significant loss in compressive strength. Although the same effects were not seen with sodium chloride brines, it was shown that sodium chloride brines have the highest rate of ingress into hardened concrete. This latter fact is significant with respect to corrosion of embedded steel. The mechanism for attack of hardened cement paste varies with deicer chemical but in general, a chemical reaction between chlorides and cement hydration products results in the dissolution of the hardened cement paste and formation of oxychloride phases, which are expansive. The chemical attack of the hardened cement paste is significantly reduced if supplementary cementitious materials are included in the concrete mixture. Both coal fly ash and ground granulated blast furnace slag were found to be effective at mitigating the chemical attack caused by the deicers tested. In the tests performed, ground granulated blast furnace slag performed better as a mitigation strategy as compared to coal fly ash. Additionally, siloxane and silane sealants were effective at slowing the ingress of deicing chemicals into the concrete and thereby reducing the observed distress. In general, the siloxane sealant appeared to be more effective than the silane, but both were effective and should be considered as a maintenance strategy.

The Deleterious Chemical Effects of Concentrated Deicing Solutions on Portland Cement Concrete, Literature Review, TR-480, 2008

This research project investigated the effects of concentrated brines of magnesium chloride, calcium chloride, sodium chloride, and calcium magnesium acetate on portland cement concrete. Although known to be effective at deicing and anti-icing, the deleterious effects these chemicals may have on concrete have not been well documented. As a result of this research, it was determined that there is significant evidence that magnesium chloride and calcium chloride chemically interact with hardened portland cement paste in concrete resulting in expansive cracking, increased permeability, and a significant loss in compressive strength. Although the same effects were not seen with sodium chloride brines, it was shown that sodium chloride brines have the highest rate of ingress into hardened concrete. This latter fact is significant with respect to corrosion of embedded steel. The mechanism for attack of hardened cement paste varies with deicer chemical but in general, a chemical reaction between chlorides and cement hydration products results in the dissolution of the hardened cement paste and formation of oxychloride phases, which are expansive. The chemical attack of the hardened cement paste is significantly reduced if supplementary cementitious materials are included in the concrete mixture. Both coal fly ash and ground granulated blast furnace slag were found to be effective at mitigating the chemical attack caused by the deicers tested. In the tests performed, ground granulated blast furnace slag performed better as a mitigation strategy as compared to coal fly ash. Additionally, siloxane and silane sealants were effective at slowing the ingress of deicing chemicals into the concrete and thereby reducing the observed distress. In general, the siloxane sealant appeared to be more effective than the silane, but both were effective and should be considered as a maintenance strategy.

The Deleterious Chemical Effects of Concentrated Deicing Solutions on Portland Cement Concrete, Technical Appendices, TR-480, 2008

This research project investigated the effects of concentrated brines of magnesium chloride, calcium chloride, sodium chloride, and calcium magnesium acetate on portland cement concrete. Although known to be effective at deicing and anti-icing, the deleterious effects these chemicals may have on concrete have not been well documented. As a result of this research, it was determined that there is significant evidence that magnesium chloride and calcium chloride chemically interact with hardened portland cement paste in concrete resulting in expansive cracking, increased permeability, and a significant loss in compressive strength. Although the same effects were not seen with sodium chloride brines, it was shown that sodium chloride brines have the highest rate of ingress into hardened concrete. This latter fact is significant with respect to corrosion of embedded steel. The mechanism for attack of hardened cement paste varies with deicer chemical but in general, a chemical reaction between chlorides and cement hydration products results in the dissolution of the hardened cement paste and formation of oxychloride phases, which are expansive. The chemical attack of the hardened cement paste is significantly reduced if supplementary cementitious materials are included in the concrete mixture. Both coal fly ash and ground granulated blast furnace slag were found to be effective at mitigating the chemical attack caused by the deicers tested. In the tests performed, ground granulated blast furnace slag performed better as a mitigation strategy as compared to coal fly ash. Additionally, siloxane and silane sealants were effective at slowing the ingress of deicing chemicals into the concrete and thereby reducing the observed distress. In general, the siloxane sealant appeared to be more effective than the silane, but both were effective and should be considered as a maintenance strategy.

Development of Non-Petroleum-Based Binders for Use in Flexible Pavements – Phase II, TR-650, 2015

Bio-binders can be utilized as asphalt modifiers, extenders, and replacements for conventional asphalt in bituminous binders. From the rheology results of Phase I of this project, it was found that the bio-binders tested had good performance, similar to conventional asphalt, except at low temperatures. Phase II of this project addresses this shortcoming and evaluates the Superpave performance of laboratory mixes produced with the enhanced bio-binders. The main objective of this research was to develop a bio-binder capable of replacing conventional asphalt in flexible pavements by incorporating ground tire rubber (GTR) into bio-oil derived from fast pyrolysis of agriculture and forestry residues. The chemical compatibility of the new bio-binder with GTR was assessed, and the low-temperature performance of the bio-binders was enhanced by the use of GTR. The newly developed binder, which consisted of 80 percent conventional binder and 20 percent rubber-modified bio-oil (85 percent bio-oil with 15 percent GTR), was used to produce mixes at two different air void contents, 4 and 7 percent. The laboratory performance test results showed that the performance of the newly developed bio-binder mixes is as good as or better than conventional asphalt mixes for fatigue cracking, rutting resistance, moisture sensitivity, and low-temperature cracking. These results need to be validated in field projects in order to demonstrate adequate performance for this innovative and sustainable technology for flexible pavements.