Search results for "Roca"
showing 10 items of 1893 documents
Effect of the shampoo Ultra Clean on drug concentrations in human hair
2000
The influence of the special shampoo Ultra Clean (Zydot Unlimited, Tulsa, Oklahoma) on the results of hair analyses was investigated. Hair samples from persons (n = 14) with a known history of drug abuse were collected at autopsy. The hair samples were divided into separate strands which were analyzed both after washing with Ultra Clean and without treatment. Hair analyses were performed by methanol extraction under sonication, purification by solid phase extraction and GC/MS in SIM mode according to routine procedures for tetrahydrocannabinol (THC), cocaine, amphetamine, methylenedioxyamphetamine (MDA), methylenedioxymethamphetamine (MDMA), methylenedioxyethylamphetamine (MDE), heroin, 6-m…
eta1-Allypalladium complexes with tridentate PNP’ ligand for the assembly of modified Screen Printed Electrodes: an electrochemical study.
2015
Specific Pd-based organometallic complex, in particular the [Pd(η1-CH2–CH=CH2)(P–N–P’)]BF4 was used for the assembly of chemically modified Screen Printed Electrodes (SPEs) and their electrochemical reactivity was also investigated. For this purpose potassium ferricyanide, hexaammineruthenium(III) chloride, sodium hexachloroiridate-(III) hydrate, ascorbic acid (AA), uric acid (UA), acetaminophen (Ac), guanine (G) and adenine (A) were used to study the electron-transfer processes, which occurred at modified SPEs, fabricated by using the [Pd(η1-CH2–CH=CH2)(P–N–P’)]BF4, applying the drop casting procedure. Interesting results were obtained in the case of the guanine (G) quantitative detection,…
Analysis of Polycyclic Aromatic Hydrocarbons and Their Oxygen-Containing Derivatives and Metabolites in Soils
2010
Although polycyclic aromatic hydrocarbons (PAHs) have been extensively studied, the knowledge of their oxygen-containing derivatives and metabolites (OPAHs) in soils is limited. We modified and tested an existing analytical protocol involving pressurized liquid extraction of soil followed by fractionation of target compounds into PAHs and OPAHs on a silica gel column and gas chromatography/ mass spectrometry-based separation and quantification. Polycyclic aromatic hydrocarbons and carbonyl-OPAHs were quantified directly after separation on silica gel columns, and hydroxyl/carboxyl-OPAHs were quantified after silylation with N,O-bis(trimethylsilyl)trifluoroacetamide. Recoveries between 78 an…
Comparison of different methods for extraction of polycyclic aromatic hydrocarbons (PAHs) from Sicilian (Italy) coastal area sediments.
2012
This paper describes a work aimed at improving the conditions of an extraction method, coupling GC-MS determination, for the analysis without cleanup phase, of polycyclic aromatic hydrocarbons (PAHs) from sediment samples. The automatic Soxhlet extraction in warm mode (using Extraction System B-811 Standard, Buchi) has demonstrated advantages for automation, reduced extraction time, and lower solvent use than for conventional Soxhlet extraction. Under these conditions, the recoveries are very good as they resulted greater than 85 % and, in most of the cases, near 100 %. The repeatability is also satisfactory (relative standard deviation less than 15 %). The detection limits are also accepta…
Fast extraction of cannabinoids in marijuana samples by using hard-cap espresso machines
2018
Abstract A simple, quick and low cost procedure was developed for the extraction of Δ9-tetrahydrocannabinol, cannabidiol, and cannabinol from marijuana samples, based on the use of a hard-cap espresso extraction with 2-propanol. After extraction, cannabinoids were directly determined after appropriate dilution by gas-chromatography-mass spectrometry, reaching a limit of detection from 0.03 to 0.05 mg g−1. Extraction efficiency was evaluated by the comparison of results obtained for seized samples by the proposed method and a reference methodology based on ultrasound-assisted extraction. Moreover, ion mobility was proposed for the rapid and sensitive determination of Δ9-tetrahydrocannabinol …
Habermas’ Universal Pragmatics: Theory of Language and Social Theory
2013
Although Habermas’ universal pragmatics has played a marginal role in studies on pragmatics, it can still make an important and meaningful contribution, precisely because it highlights the system of validity claims that lie in speech acts. This type of analysis allows one to consider the dialogic dynamics that engage speakers in the activity of reciprocal giving and asking for reasons for saying and doing things. The reasons why a speaker knows he or she can say what he or she says in the presence of other speakers constitute an essential element of the production of meaning; and reciprocally identification of the speaker’s reasons by the listener is an indispensable condition of the activi…
takotsubo cardiomiopathy after acute diarrhea
2010
Takotsubo cardiomyopaty is a recently described syndrome characterized by transient left ventricular dysfunction, mimicking an acute coronary syndrome and usually precipitated by a physical or emotional stress. We report the first case of Takotsubo cardiomyopathy after acute diarrhea in a man. It may be argued that severe diarrhea in predisposed individuals may cause an acute stress resulting in increased sympathetic activity leading to this syndrome. Probably the relationship between the adrenergic system and the heart is more complex than general thought and the stimuli which favor an autonomic imbalance and precipitate the syndrome are very disparate in clinical practice.
Organochlorinated pesticides in sediments from the Lake Albufera of Valencia (Spain).
2005
Bottom sediment samples from 121 sites of the Lake Albufera of Valencia were analyzed. Dieldrin, endrin, heptachlor and op'-DDT were not detected (0.01 ng g(-1)) in 88-93% of the sites. Aldrin and HCB concentration ranges were between0.01 and 0.1 ng g(-1) in 86% and 94% of the sites, respectively. Heptachlor-epoxide and lindane 95% confidence intervals were 0.2-0.5 and 0.06-0.12, respectively. The greatest average concentration corresponds to pp'-DDE, pp'-DDD and pp'-DDT. The sum of six isomers and derivatives of the DDT average concentration reaches 2.1 ng g(-1), as opposed to 2.7 ng g(-1) for the sum of 13 pesticides considered. In the site with a major contamination, 27.0 ng g(-1) of pp'…
Hepatic metabolism of diclofenac: role of human CYP in the minor oxidative pathways.
1999
The aim of this study was to re-examine the human hepatic metabolism of diclofenac, with special focus on the generation of minor hydroxylated metabolites implicated in the idiosyncratic hepatotoxicity of the drug. Different experimental approaches were used: human hepatocytes, human microsomes, and engineered cells expressing single human CYP (cytochromes P450). Human hepatocytes formed 3'-hydroxy-, 4'-hydroxy-, 5-hydroxy- 4',5-dihydroxy-, and N,5-dihydroxydiclofenac, as well as several lactams. Formation of 4'- and 5-hydroxydiclofenac by human liver microsomes followed a Michaelis-Menten kinetics (Km 9 +/- 1 microM; Vmax 432 +/- 15 pmol/min/mg and Km 43 +/- 5 microM; and Vmax 15.4 +/- 0.6…
Global Non-monotonicity of Solutions to Nonlinear Second-Order Differential Equations
2018
We study behavior of solutions to two classes of nonlinear second-order differential equations with a damping term. Sufficient conditions for the first derivative of a solution x(t) to change sign at least once in a given interval (in a given infinite sequence of intervals) are provided. These conditions imply global non-monotone behavior of solutions.