Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters










Database
Language
Publication year range
1.
Drug Test Anal ; 6(5): 492-9, 2014 May.
Article in English | MEDLINE | ID: mdl-24665024

ABSTRACT

The increasing number of new psychoactive substances made available for recreational drug use has created a challenge for clinical toxicology and drug testing laboratories. As a consequence, the routine immunoassay drug testing may become less effective due to an increased occurrence of false negative and false positive screening results. This work aimed to extend the knowledge about analytical cross-reactivity of new substances in selected CEDIA, EMIT, and KIMS immunoassays for drugs-of-abuse screening. Urine standards were prepared by spiking blank urine with 45 new substances. Authentic urine samples from intoxication cases identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) were also studied. Several new psychoactive substances were demonstrated to display cross-reactivity in the immunoassays. CEDIA Amphetamine/Ecstasy and EMIT d.a.u. Amphetamine Class tests showed the highest reactivity towards the new drugs, which was expected since many have amphetamine-like structure and activity. In the samples from authentic cases, five new substances displayed 100% detection rate in the CEDIA Amphetamine/Ecstasy test. In conclusion, cross-reactivity data in routine urine drug screening immunoassays for a number of new psychoactive substances not studied before were reported. In both spiked and authentic urine samples, some new substances showed significant cross-reactivity and are thus detectable in the routine screening methods.


Subject(s)
Psychotropic Drugs/urine , Substance Abuse Detection/methods , Cross Reactions , Humans , Immunoassay/methods , Psychotropic Drugs/immunology
2.
Radiat Prot Dosimetry ; 131(2): 212-6, 2008.
Article in English | MEDLINE | ID: mdl-18503064

ABSTRACT

In retrospective radon measurements, the 22-y half life of (210)Pb is used as an advantage. (210)Pb is often considered to be relatively immobile in glass after alpha recoil implanted by (222)Rn progenies. The diffusion of (210)Pb could, however, lead to uncertain wrong retrospective radon exposure estimations if (210)Pb is mobile and can escape from glass, or lost as a result of cleaning-induced surface modification. This diffusion was studied by a radiotracer technique, where (209)Pb was used as a tracer in a glass matrix for which the elemental composition is known. Using the ion guide isotope separator on-line technique, the (209)Pb atoms were implanted into the glass with an energy of 39 keV. The diffusion profiles and the diffusion coefficients were determined after annealing at 470-620 degrees C and serial sectioning by ion sputtering. In addition, the effect of surface cleaning on diffusion was tested. From the Arrhenius fit, the activation enthalpy (H) was determined, which is equal to 3.2 +/- 0.2 eV, and also the pre-exponential factor D(0), in the order of 20 m(2)s(-1). This result confirms the assumption that over a time period of 50 y (209)Pb (and (210)Pb) is effectively immobile in the glass. The boundary condition obtained from the measurements had the characteristic of a sink, implying loss of (209)Pb in the topmost surface at high temperatures.


Subject(s)
Glass/chemistry , Lead Radioisotopes/analysis , Radon/analysis , Cyclotrons , Detergents , Diffusion , Models, Statistical , Radiometry , Temperature , Time Factors
3.
Science ; 312(5782): 1959-61, 2006 Jun 30.
Article in English | MEDLINE | ID: mdl-16809542

ABSTRACT

Several bird species have advanced the timing of their spring migration in response to recent climate change. European short-distance migrants, wintering in temperate areas, have been assumed to be more affected by change in the European climate than long-distance migrants wintering in the tropics. However, we show that long-distance migrants have advanced their spring arrival in Scandinavia more than short-distance migrants. By analyzing a long-term data set from southern Italy, we show that long-distance migrants also pass through the Mediterranean region earlier. We argue that this may reflect a climate-driven evolutionary change in the timing of spring migration.


Subject(s)
Animal Migration , Birds/physiology , Climate , Seasons , Africa , Animals , Biological Evolution , Cues , Flight, Animal , Italy , Scandinavian and Nordic Countries
4.
Article in English | MEDLINE | ID: mdl-34170984

ABSTRACT

In autumn 1998, nocturnal bird migration at Falsterbo was recorded over a period of three months by means of a passive infrared device. At the same place a standardised trapping scheme is in operation. This study reveals for the first time a positive correlation between the migratory intensity of birds aloft and the numbers of trapped birds. By relating the migratory patterns of single species with the nocturnal migratory intensities, we show that the species composition aloft can at least partly be deduced from the number of grounded birds. The numbers of trapped pre-Saharan migrants were related more strongly to the migratory intensity of the preceding night than were the numbers of trans-Saharan migrants. Assuming that the number of trapped birds varies according to the weather to the same -extent as the migratory intensity of birds aloft, we conclude that in shorter range migrants the decision to engage in a migratory flight is influenced more strongly by weather conditions, and that the migratory activity of trans-Saharan migrants is possibly more intensely controlled by their endogenous migratory urge.

SELECTION OF CITATIONS
SEARCH DETAIL
...