Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 19 de 19
Filter
Add more filters

Country/Region as subject
Affiliation country
Publication year range
1.
Molecules ; 27(19)2022 Oct 06.
Article in English | MEDLINE | ID: mdl-36235182

ABSTRACT

Aloe barbadensis Mill. (Aloe) is used for diverse therapeutic properties including immunomodulation. However, owing to the compositionally complex nature of Aloe, bioactive component(s) responsible for its beneficial properties, though thought to be attributed to polysaccharides (acemannan), remain unknown. We therefore aimed to determine the metabolite composition of various commercial Aloe extracts and assess their effects on human blood T cell activity in vitro. Peripheral blood mononuclear cells (PBMC) from healthy donors were stimulated polyclonally in presence or absence of various Aloe extracts. T cell phenotype and proliferation were investigated by flow cytometry. Aloe extracts were analyzed using targeted 1H-NMR spectroscopy for standard phytochemical quality characterization and untargeted gas chromatography mass spectrometry (GC-MS) for metabolite profiling. Aloe extracts differing in their standard phytochemical composition had varying effects on T cell activation, proliferation, apoptosis, and cell-death in vitro, although this was not related to the acemannan content. Furthermore, each Aloe extract had its own distinct metabolite profile, where extracts rich in diverse sugar and sugar-derivatives were associated with reduced T cell activity. Our results demonstrate that all commercial Aloe extracts are unique with distinct metabolite profiles, which lead to differential effects on T cell activity in vitro, independent of the acemannan content.


Subject(s)
Aloe , Aloe/chemistry , Humans , Leukocytes, Mononuclear/metabolism , Plant Extracts/chemistry , Polysaccharides/metabolism , Sugars/metabolism , T-Lymphocytes/metabolism
2.
ACS Appl Energy Mater ; 5(11): 13971-13980, 2022 Nov 28.
Article in English | MEDLINE | ID: mdl-36465259

ABSTRACT

Zn1-x Sn x O y (ZTO) deposited by atomic layer deposition has shown promising results as a buffer layer material for kesterite Cu2ZnSnS4 (CZTS) thin film solar cells. Increased performance was observed when a ZTO buffer layer was used as compared to the traditional CdS buffer, and the performance was further increased after an air annealing treatment of the absorber. In this work, we study how CZTS absorber surface treatments may influence the chemical and electronic properties at the ZTO/CZTS interface and the reactions that may occur at the absorber surface prior to atomic layer deposition of the buffer layer. For this, we have used a combination of microscopy and synchrotron-based spectroscopies with variable information depths (X-ray photoelectron spectroscopy, high-energy X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy), allowing for an in-depth analysis of the CZTS near-surface regions and bulk material properties. No significant ZTO buffer thickness variation is observed for the differently treated CZTS absorbers, and no differences are observed when comparing the bulk properties of the samples. However, the formation of SnO x and compositional changes observed toward the CZTS surface upon an air annealing treatment may be linked to the modified buffer layer growth. Further, the results indicate that the initial N2 annealing step integrated in the buffer layer growth by atomic layer deposition, which removes Na-CO x species from the CZTS surface, may be useful for the ZTO/CZTS device performance.

3.
Therap Adv Gastroenterol ; 14: 17562848211048133, 2021.
Article in English | MEDLINE | ID: mdl-34646359

ABSTRACT

BACKGROUND: Aloe barbadensis Mill. (Aloe) extract was found to be well-tolerated, safe and showed beneficial effects in subsets of irritable bowel syndrome (IBS) patients in two randomized, double-blind, controlled studies. However, the individual studies were underpowered to perform subgroup analyses. We therefore determined the effect of Aloe extract in IBS subgroups in a post hoc analysis combining the results from the two studies. METHODS: Data from the two controlled studies comparing Aloe and control treatment taken orally for 4 weeks, were pooled. Both studies included IBS patients fulfilling the ROME III criteria and IBS Symptom Severity Score (IBS-SSS) was assessed. We analysed the effect of Aloe extract on IBS symptom severity and the proportion of responders (IBS-SSS reduction ⩾ 50) in IBS subgroups. RESULTS: In total, 213 IBS patients were included in the post hoc subgroup analyses. A reduction in overall symptom severity, primarily driven by effect on pain severity and frequency, comparing baseline versus end of treatment, was recorded in IBS patients with diarrhoea (IBS-D) receiving Aloe (n = 38, p < 0.001) but not control treatment (n = 33, p = 0.33), with difference between the treatment groups (p = 0.01). Moreover, the frequency of responders was higher in IBS-D patients receiving Aloe (n = 22, 58%) compared to control treatment (n = 10, 30%) (p = 0.02). The effect of Aloe extract treatment on IBS symptom severity was not superior to control treatment in the other IBS subtypes. CONCLUSION: Aloe extract improves symptom severity in IBS-D patients and can be regarded as a safe and effective treatment option for this patient group.

4.
BMJ Simul Technol Enhanc Learn ; 6(4): 220-228, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32832101

ABSTRACT

INTRODUCTION: Analyses of simulation performance taking place during postsimulation debriefings have been described as iterating through phases of unawareness of problems, identifying problems, explaining the problems and suggesting alternative strategies or solutions to manage the problems. However, little is known about the mechanisms that contribute to shifting from one such phase to the subsequent one. The aim was to study which kinds of facilitator interactions contribute to advancing the participants' analyses during video-assisted postsimulation debriefing. METHODS: Successful facilitator behaviours were analysed by performing an Interaction-Analytic case study, a method for video analysis with roots in ethnography. Video data were collected from simulation courses involving medical and midwifery students facilitated by highly experienced facilitators (6-18 years, two paediatricians and one midwife) and analysed using the Transana software. A total of 110 successful facilitator interventions were observed in four video-assisted debriefings and 94 of these were included in the analysis. As a starting point, the participants' discussions were first analysed using the phases of a previously described framework, uPEA (unawareness (u), problem identification (P), explanation (E) and alternative strategies/solutions (A)). Facilitator interventions immediately preceding each shift from one phase to the next were thereafter scrutinised in detail. RESULTS: Fifteen recurring facilitator behaviours preceding successful shifts to higher uPEA levels were identified. While there was some overlap, most of the identified facilitator interventions were observed during specific phases of the debriefings. The most salient facilitator interventions preceding shifts to subsequent uPEA levels were respectively: use of video recordings to draw attention to problems (P), questions about opinions and rationales to encourage explanations (E) and dramatising hypothetical scenarios to encourage alternative strategies (A). CONCLUSIONS: This study contributes to the understanding of how certain facilitator behaviours can contribute to the participants' analyses of simulation performance during specific phases of video-assisted debriefing.

5.
Neurogastroenterol Motil ; 32(8): e13860, 2020 08.
Article in English | MEDLINE | ID: mdl-32314514

ABSTRACT

BACKGROUND: Aloe barbadensis Mill. (Aloe) with potential prebiotic effects has been suggested to reduce symptoms in patients with irritable bowel syndrome (IBS). We therefore aimed to determine the effects of an Aloe extract on symptoms of IBS, and evaluate whether effects may be mediated by fecal microbiota and metabolites in a randomized, double-blind, controlled trial. METHODS: Patient with IBS diagnosed according to the ROME III criteria (all subtypes), received Aloe or control treatment (inulin) for 4 weeks. IBS Symptom Severity Score (IBS-SSS) was assessed, and fecal samples collected before and at end of treatment. Fecal microbiota composition and metabolomic profile were determined. KEY RESULTS: In total, 160 IBS patients completed the study. The overall severity of IBS symptoms was reduced in both Aloe and control treatment groups (P < .001, both groups, comparing baseline vs end of treatment), without difference between groups (P = .62). The frequency of responders (IBS-SSS reduction ≥ 50) did not differ between Aloe treatment (n = 33, 39%) and control (n = 34, 45%) (P = .49). However, fecal microbiota and metabolite profiles differed between Aloe, but not control treatment responders and non-responders both before and after treatment. CONCLUSION: In a mixed group of IBS patients, Aloe was not superior to control treatment, although it showed potential to reduce IBS symptom severity in subsets of IBS patients which could be predicted by fecal microbiota and metabolite profiles. ClinicalTrials.gov no: NCT01400048.


Subject(s)
Aloe , Gastrointestinal Microbiome/drug effects , Irritable Bowel Syndrome/drug therapy , Plant Extracts/pharmacology , Adolescent , Adult , Aged , Double-Blind Method , Feces/microbiology , Female , Humans , Irritable Bowel Syndrome/diagnosis , Irritable Bowel Syndrome/metabolism , Male , Middle Aged , Plant Extracts/therapeutic use , Severity of Illness Index , Treatment Outcome , Young Adult
6.
Cancer Res ; 67(15): 7512-7, 2007 Aug 01.
Article in English | MEDLINE | ID: mdl-17671222

ABSTRACT

(131)I radiation therapy of differentiated thyroid cancer may be compromised by thyroid stunning (i.e., a paradoxical inhibition of radioiodine uptake caused by radiation from a pretherapeutic diagnostic examination). The stunning mechanism is yet uncharacterized at the molecular level. We therefore investigated whether the expression of the sodium/iodide symporter (NIS) gene is changed by irradiation using (131)I. Confluent porcine thyroid cells on filter were stimulated with thyroid-stimulating hormone (TSH; 1 milliunit/mL) or insulin-like growth factor-I (IGF-I; 10 ng/mL) and simultaneously exposed to (131)I in the culture medium for 48 h, porcine NIS mRNA was quantified by real-time reverse transcription-PCR using 18S as reference, and transepithelial iodide transport was monitored using (125)I(-) as tracer. TSH increased the NIS expression >100-fold after 48 h and 5- to 20-fold after prolonged stimulation. IGF-I enhanced the NIS transcription at most 15-fold but not until 5 to 7 days. (131)I irradiation (7.5 Gy) decreased both TSH-stimulated and IGF-I-stimulated NIS transcription by 60% to 90% at all investigated time points. TSH and IGF-I stimulated NIS synergistically 15- to 60-fold after 5 days. NIS expression was reduced by (131)I also in costimulated cells, but the transcription level remained higher than in nonirradiated cells stimulated with TSH alone. Changes in NIS mRNA always correlated with altered (125)I(-) transport in cultures with corresponding treatments. It is concluded that down-regulation of NIS is the likely explanation of (131)I-induced thyroid stunning. Enhanced NIS expression by synergistically acting agents (TSH and IGF-I) partly prevents the loss of iodide transport expected from a given absorbed dose, suggesting that thyroid stunning might be pharmacologically treatable.


Subject(s)
Iodine Radioisotopes/adverse effects , Radiation Injuries/etiology , Symporters/metabolism , Thyroid Diseases/etiology , Thyroid Gland/radiation effects , Animals , Down-Regulation , Insulin-Like Growth Factor I/pharmacology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Radiation Injuries/prevention & control , Radionuclide Imaging , Reverse Transcriptase Polymerase Chain Reaction , Swine , Symporters/antagonists & inhibitors , Symporters/genetics , Thyroid Diseases/diagnostic imaging , Thyroid Diseases/prevention & control , Thyroid Gland/diagnostic imaging , Thyroid Gland/injuries , Thyrotropin/pharmacology
7.
Scand J Trauma Resusc Emerg Med ; 27(1): 57, 2019 May 24.
Article in English | MEDLINE | ID: mdl-31126312

ABSTRACT

STUDY OBJECTIVE: The objective of this study was to investigate how the terrorist attack in Stockholm, Sweden affected patient inflow to the general emergency departments (EDs) in close proximity of the attack. The study analyzed if, and to what extent, the attack impacted ED inflow during the following days and weeks. METHODS: In a retrospective observational study, anonymized aggregated data on ED arrivals (inflow of patients) to all seven of the EDs in the Stockholm County was analyzed using the Difference-in-Differences (DiD) estimator. The control groups were the affected hospitals in the years prior to the terrorist attack. The number of ED visits was retrieved from the Stockholm County Council administrative database. RESULTS: The study shows a statistically significant reduction in overall ED inflow of 7-9% following the attack. The effect was strongest initially after the attack, and ED inflow regained normal levels within approximately three weeks' time, without any significant rebound effect. The effect on ED inflow also decreased with distance from ground zero, and was not significant further away than 10 km. CONCLUSION: The results showed that ED inflow was significantly decreased in the weeks immediately following the Stockholm terrorist attack. The reasons for this cannot be fully explained in this observational study. However, the results suggest that some patients actively choose when, where and if they should go to the ED.


Subject(s)
Emergency Service, Hospital , Patient Acceptance of Health Care , Terrorism , Adult , Databases, Factual , Emergency Service, Hospital/statistics & numerical data , Female , Health Behavior , Hospitals , Humans , Male , Mental Disorders , Middle Aged , Patient Acceptance of Health Care/statistics & numerical data , Retrospective Studies , Sweden
9.
Sci Rep ; 8(1): 5265, 2018 Mar 22.
Article in English | MEDLINE | ID: mdl-29567983

ABSTRACT

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

10.
Sci Rep ; 7(1): 10018, 2017 08 30.
Article in English | MEDLINE | ID: mdl-28855553

ABSTRACT

Lithium-ion battery fires generate intense heat and considerable amounts of gas and smoke. Although the emission of toxic gases can be a larger threat than the heat, the knowledge of such emissions is limited. This paper presents quantitative measurements of heat release and fluoride gas emissions during battery fires for seven different types of commercial lithium-ion batteries. The results have been validated using two independent measurement techniques and show that large amounts of hydrogen fluoride (HF) may be generated, ranging between 20 and 200 mg/Wh of nominal battery energy capacity. In addition, 15-22 mg/Wh of another potentially toxic gas, phosphoryl fluoride (POF3), was measured in some of the fire tests. Gas emissions when using water mist as extinguishing agent were also investigated. Fluoride gas emission can pose a serious toxic threat and the results are crucial findings for risk assessment and management, especially for large Li-ion battery packs.

11.
ACS Appl Mater Interfaces ; 9(35): 29707-29716, 2017 Sep 06.
Article in English | MEDLINE | ID: mdl-28792724

ABSTRACT

The compatibility of atomic layer deposition directly onto the mixed halide perovskite formamidinium lead iodide:methylammonium lead bromide (CH(NH2)2, CH3NH3)Pb(I,Br)3 (FAPbI3:MAPbBr3) perovskite films is investigated by exposing the perovskite films to the full or partial atomic layer deposition processes for the electron selective layer candidates ZnO and SnOx. Exposing the samples to the heat, the vacuum, and even the counter reactant of H2O of the atomic layer deposition processes does not appear to alter the perovskite films in terms of crystallinity, but the choice of metal precursor is found to be critical. The Zn precursor Zn(C2H5)2 either by itself or in combination with H2O during the ZnO atomic layer deposition (ALD) process is found to enhance the decomposition of the bulk of the perovskite film into PbI2 without even forming ZnO. In contrast, the Sn precursor Sn(N(CH3)2)4 does not seem to degrade the bulk of the perovskite film, and conformal SnOx films can successfully be grown on top of it using atomic layer deposition. Using this SnOx film as the electron selective layer in inverted perovskite solar cells results in a lower power conversion efficiency of 3.4% than the 8.4% for the reference devices using phenyl-C70-butyric acid methyl ester. However, the devices with SnOx show strong hysteresis and can be pushed to an efficiency of 7.8% after biasing treatments. Still, these cells lacks both open circuit voltage and fill factor compared to the references, especially when thicker SnOx films are used. Upon further investigation, a possible cause of these losses could be that the perovskite/SnOx interface is not ideal and more specifically found to be rich in Sn, O, and halides, which is probably a result of the nucleation during the SnOx growth and which might introduce barriers or alter the band alignment for the transport of charge carriers.

12.
Lakartidningen ; 1132016 12 20.
Article in Swedish | MEDLINE | ID: mdl-28026839

ABSTRACT

Acute splenic sequestration in children with sickle cell disease - an overview Acute splenic sequestration (ASS) is a life-threatening complication of sickle cell disease (SCD). The condition is important to recognize due to the fact that it can occur with previously unknown disease. ASS is one of the most common causes of death in children with SCD and is the result of blood suddenly getting congested in the spleen, resulting in splenomegaly, acute anemia, and hypovolemic shock. Timely and appropriate treatment is essential in preventing death. Episodes of ASS before one year of age are associated with a higher risk of recurrence. There is no established effective treatment for recurrent ASS; however, there is evidence that all children with SCD should be treated with hydroxyurea. In Sweden, our recommendation is to evaluate the indications for splenectomy after the first episode of ASS. Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative treatment, and all children with SCD should be evaluated with regard to the potential success of HSCT. This article presents an overview of the condition with Swedish recommendations.


Subject(s)
Anemia, Sickle Cell/complications , Splenic Diseases/etiology , Acute Disease , Anemia, Sickle Cell/epidemiology , Anemia, Sickle Cell/physiopathology , Anemia, Sickle Cell/surgery , Child , Child, Preschool , Critical Illness , Hematopoietic Stem Cell Transplantation , Humans , Infant , Male , Recurrence , Risk , Splenectomy , Splenic Diseases/pathology , Splenic Diseases/surgery , Sweden
13.
J Ethnopharmacol ; 179: 301-9, 2016 Feb 17.
Article in English | MEDLINE | ID: mdl-26771068

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Aloe barbadensis Mill. (Aloe vera) is a widely used medicinal plant well reputed for its diverse therapeutic applications. It has been used for thousands of years in folk medicine to treat various conditions and the Aloe vera gel has been reported to possess anti-inflammatory as well as immunostimulatory and immunomodulatory properties. However, the mode of action is still unclear. AIM OF THE STUDY: The aim of this study was determine the effects of two well-defined A. barbadensis Mill. extracts AVH200® and AVE200 on human blood T cells in vitro. MATERIALS AND METHODS: Peripheral blood mononuclear cells (PBMC) from healthy donors were stimulated polyclonally in the presence or absence of AVH200® and AVE200. The T cell phenotype was investigated by flow cytometry, cell proliferation was determined by CFSE dye and thymidine assay, respectively and cytokine secretion was determined by MSD® Multi-Spot Assay system and ELISA. RESULTS: The presence of AVH200® resulted in a reduced expression of CD25 among CD3(+) T cells and suppression of T cell proliferation in a dose dependent manner. Furthermore, AVH200® reduced the expression of CD28 on CD3(+) T cells. AVH200® also reduced the secretion of IL-2, IFN-γ and IL-17A in PBMC cultures. The AVH200® dose dependent reduction in T cell activation and proliferation recorded in the cell cultures was not due to apoptosis or cell death. Additionally, AVH200® was found to be more effective as compared to AVE200 in reducing T cell activation and proliferation. CONCLUSION: AVH200® has the potential to reduce the activation, proliferation and cytokine secretion of healthy human blood T cells. Our study suggests that AVH200® has a suppressive effect on human blood T cells in vitro.


Subject(s)
Aloe/chemistry , Plant Extracts/pharmacology , T-Lymphocytes/drug effects , T-Lymphocytes/immunology , Adolescent , Adult , Apoptosis/drug effects , Cell Death/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Cytokines/metabolism , Dose-Response Relationship, Drug , Humans , Immunosuppressive Agents/pharmacology , Lymphocyte Activation/drug effects , Middle Aged , T-Lymphocytes/cytology , T-Lymphocytes/metabolism , Young Adult
14.
Oncogene ; 22(38): 6013-22, 2003 Sep 04.
Article in English | MEDLINE | ID: mdl-12955080

ABSTRACT

The adenomatous polyposis coli (APC) tumor suppressor is a nucleocytoplasmic protein. The nuclear accumulation of APC was recently found to vary depending on cell density, suggesting that putative APC function(s) in the nucleus is controlled by the establishment of cell contacts. We report here that the density-dependent redistribution of APC between nucleus and cytoplasm prevails in 6/6 thyroid and colorectal carcinoma cell lines. Moreover, mutated APC lacking known nuclear localization sequences had the similar distribution pattern as the full-length protein. APC invariably accumulated in the nuclei of Ki-67 expressing cells, but was largely cytoplasmic when cell cycle exit was induced by serum starvation or at high cell density. APC colocalized with beta-catenin in the nucleus only in one cell line (SW480). Also, APC maintained a predominantly nuclear position in early confluent states when cytoplasmic beta-catenin was recruited to newly formed adherens-like junctions. The results indicate that nuclear targeting of APC is driven by cell cycle entry rather than altered cell-cell contact. The ability of C-terminally truncated APC to accumulate in the nucleus suggests that nuclear import signals other than NLS1(APC) and NLS2(APC) are functionally important. Residual function(s) of N-terminal APC fragments in tumor cells carrying APC mutations might be beneficial to tumor growth and survival.


Subject(s)
Adenomatous Polyposis Coli Protein/genetics , Adenomatous Polyposis Coli Protein/metabolism , Carcinoma/metabolism , Cell Nucleus/metabolism , Colorectal Neoplasms/metabolism , Thyroid Neoplasms/metabolism , Animals , Binding Sites , Carcinoma/pathology , Cell Cycle/physiology , Cell Division/physiology , Colorectal Neoplasms/pathology , Cytoplasm/metabolism , Cytoskeletal Proteins/metabolism , Humans , Ki-67 Antigen/metabolism , Mutation , Nuclear Localization Signals , Thyroid Neoplasms/pathology , Trans-Activators/metabolism , Tumor Cells, Cultured , beta Catenin
15.
J Chromatogr A ; 975(1): 157-64, 2002 Oct 25.
Article in English | MEDLINE | ID: mdl-12458756

ABSTRACT

A method for the extraction of clenbuterol from calf urine samples using a molecularly imprinted polymer (MIP) has been developed. The aim was that the final extracts from the MIP should allow quantitation of clenbuterol down to 0.5 ng/mL urine using HPLC with UV detection. The MIP was produced using brombuterol as a template and the selectivity of the MIP, for clenbuterol, was tested against a non-imprinted polymer (produced without template) and was found to be high. After loading of 5 mL diluted centrifuged urine, selective binding was established in acetonitrile-acetic acid (98:2). For further elution of interferences, 0.5 M ammonium acetate buffer pH 5 and 70% acetonitrile in water was used. Clenbuterol was eluted using 1% trifluoroacetic acid in methanol, which was evaporated and reconstituted in buffer. Results from the HPLC analyses showed that the extraction of clenbuterol using MIP is linear in the range 0.5-100 ng/mL with good precision (4.3% for 0.6 ng/mL and 2.1% for 6.0 ng/mL) and accuracy (96.7% for 0.6 ng/mL and 96.7% for 6.0 ng/mL). The recoveries were 75%. The results show that the method offers a selectivity and sensitivity that make the quantitation of 0.5 ng clenbuterol/mL urine by HPLC-UV possible and a competitive alternative to state-of-the-art routine analytical methods.


Subject(s)
Adrenergic alpha-Agonists/urine , Chromatography, High Pressure Liquid/methods , Clenbuterol/urine , Spectrophotometry, Ultraviolet/methods , Animals , Cattle , Reference Standards , Reproducibility of Results , Sensitivity and Specificity
16.
Article in English | MEDLINE | ID: mdl-15093162

ABSTRACT

Methods based on molecular recognition mechanisms for the clean-up of veterinary drugs and their residues, such as immuno-, receptor- and acceptor-affinity and molecularly imprinted polymers (MIPs), have been described as selective tools to improve the selectivity and the reliability of analytical results. In this work, we tested the extraction recovery performances of a MISPE column, designed for multi-residual clean-up of beta-agonists. For this purpose, 18 different samples of calf urine were spiked at 0.25, 0.50 and 1.00 ppb with pooled standard solutions of clenbuterol (Clen), tulobuterol (Tolu), isoxsuprine (Isox), brombuterol (Brom), mapenterol (Mape) and ractopamine (Racto) and analysed on two independent analytical sessions, on a LC-MS/MS ion trap detector. Averaged recoveries, constant for each molecule considered, were 64.6% for Racto, 63.0% for Salm, 59.9% for Form, 54.7% for Brom, 52.0% for Clen, 41.8% for Mape, 38.6% for Tolu and 34.5% for Isox, respectively. Reproducibility studies gave a CV < 11% at the 0.25 ppb level. The decision limit for the identification of the target drugs ranged from 0.01 ppb for mapenterol to 0.19 ppb for salmeterol, when considering one precursor, and two product ions as identification points. Such findings indicate that the choice of the appropriate molecule as template in the MIP preparation is the critical factor to guarantee a reliable analytical multi-residue approach for beta-agonists, despite the structural differences among molecules exploiting almost the same pharmacological effect.


Subject(s)
Adrenergic beta-Agonists/urine , Drug Residues/analysis , Animals , Cattle , Chromatography, Liquid/methods , Mass Spectrometry/methods , Polymers/chemistry , Reproducibility of Results
17.
Pharmacol Biochem Behav ; 73(1): 193-207, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12076739

ABSTRACT

In this study, we report differential behavioural and cognitive effects, as assessed in the open-field and the Morris water maze, following psychological stress in enriched vs. impoverished housed rats. Three stress conditions were evaluated: nonstress, mild stress and powerful stress. Mild stress consisted of exposure to an avoidance box but without shock, while in the powerful stress condition animals were exposed to an electric shock. The results revealed distinct effects in the differentially housed animals. Prior exposure to a mild stress enhanced escape performance in the water maze in enriched but not impoverished animals. However, preexposure to powerful stress negatively affected animals from both housing conditions in the water maze task, but with the enriched animals less affected than impoverished animals. In the open-field test, stress preexposure reduced locomotion counts in both the differentially housed animals. In addition, the results showed that the enrichment effect on emotional reactivity in the open-field is long-lasting and persists even after extensive training and housing in standard laboratory conditions. The results are discussed in relation to the nature of the behavioural and learning differences between the differentially housed animals.


Subject(s)
Environment , Escape Reaction , Maze Learning , Motor Activity , Stress, Psychological/psychology , Animals , Housing, Animal/statistics & numerical data , Male , Rats , Rats, Sprague-Dawley
18.
IEEE Trans Pattern Anal Mach Intell ; 35(1): 118-29, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22392708

ABSTRACT

We propose a novel method for iterative learning of point correspondences between image sequences. Points moving on surfaces in 3D space are projected into two images. Given a point in either view, the considered problem is to determine the corresponding location in the other view. The geometry and distortions of the projections are unknown, as is the shape of the surface. Given several pairs of point sets but no access to the 3D scene, correspondence mappings can be found by excessive global optimization or by the fundamental matrix if a perspective projective model is assumed. However, an iterative solution on sequences of point-set pairs with general imaging geometry is preferable. We derive such a method that optimizes the mapping based on Neyman's chi-square divergence between the densities representing the uncertainties of the estimated and the actual locations. The densities are represented as channel vectors computed with a basis function approach. The mapping between these vectors is updated with each new pair of images such that fast convergence and high accuracy are achieved. The resulting algorithm runs in real time and is superior to state-of-the-art methods in terms of convergence and accuracy in a number of experiments.


Subject(s)
Algorithms , Artificial Intelligence , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Pattern Recognition, Automated/methods , Subtraction Technique , Online Systems
SELECTION OF CITATIONS
SEARCH DETAIL