| 1. |
- Abelev, Betty, et al.
(author)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
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In: Journal of High Energy Physics. - 1029-8479. ; :11
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Journal article (peer-reviewed)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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| 2. |
- Abelev, Betty, et al.
(author)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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In: Journal of High Energy Physics. - 1029-8479. ; :7
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Journal article (peer-reviewed)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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| 3. |
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| 4. |
- Bongaerts, Eva, et al.
(author)
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Ambient black carbon particles in human ovarian tissue and follicular fluid
- 2023
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In: Environment International. - : Elsevier. - 0160-4120 .- 1873-6750. ; 179
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Journal article (peer-reviewed)abstract
- Evidence indicates a link between exposure to ambient air pollution and decreased female fertility. The ability of air pollution particles to reach human ovarian tissue and follicles containing the oocytes in various maturation stages has not been studied before. Particulate translocation might be an essential step in explaining reproductive toxicity and assessing associated risks. Here, we analysed the presence of ambient black carbon particles in (i) follicular fluid samples collected during ovum pick-up from 20 women who underwent assisted reproductive technology treatment and (ii) adult human ovarian tissue from 5 individuals. Follicular fluid and ovarian tissue samples were screened for the presence of black carbon particles from ambient air pollution using white light generation by carbonaceous particles under femtosecond pulsed laser illumination. We detected black carbon particles in all follicular fluid (n = 20) and ovarian tissue (n = 5) samples. Black carbon particles from ambient air pollution can reach the ovaries and follicular fluid, directly exposing the ovarian reserve and maturing oocytes. Considering the known link between air pollution and decreased fertility, the impact of such exposure on oocyte quality, ovarian ageing and fertility needs to be clarified urgently.
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| 5. |
- Cotgreave, Ian, et al.
(author)
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Pyriproxifen and microcephaly: an investigation of potential ties to the ongoing "Zika epidemic"
- 2016
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Reports (other academic/artistic)abstract
- As part of the Swetox mission to react to emerging concerns in chemical health and environmental safety, a preliminary litterature investigation was undertaken to gather all readily available scientific information on PPF with respect to safety assessment, in order to better understand potential links between chemical exposure and the devopment of microcephaly in affected areas. Therefore the contents of the report do not constitute an attempt at either questioning the use of existing regulatory data in the manner prescribed by international regulatory proceedures, or as a new risk assessment, based on the scientific information and concepts discussed. Here we report our findings, with particular emphasis on exisiting regulatory information, potential for lack of translation of results from regulatory animal testing to humans, lack of human exposure data and suggestions on plausible mode(s) of action of PPF in human neurodevelopmental adversities such as microcephaly.
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| 6. |
- Huerta-García, Elizabeth, et al.
(author)
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Internalization of Titanium Dioxide Nanoparticles Is Mediated by Actin-Dependent Reorganization and Clathrin- and Dynamin-Mediated Endocytosis in H9c2 Rat Cardiomyoblasts
- 2019
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In: Chemical Research in Toxicology. - : American Chemical Society (ACS). - 0893-228X .- 1520-5010. ; 32:4, s. 578-588
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Journal article (peer-reviewed)abstract
- Titanium dioxide nanoparticles (TiO2 NPs) are widely used for industrial and commercial applications. Once inside the body, they translocate into the bloodstream and reach different areas of the cardiovascular system including the heart, increasing the risk of developing cardiovascular diseases; consequently, the investigation of their interaction with cardiac cells is required. We previously showed that TiO2 NPs are internalized by H9c2 rat cardiomyoblasts, and here, we examined the molecular mechanisms underlying this process. TiO2 NPs internalization was evaluated by transmission electron microscopy, time-lapse microscopy, and flow cytometry. Changes in the actin cytoskeleton were studied by phalloidin staining. Endocytic uptake mechanisms for nanoparticles were probed with chemical inhibitors, whereas clathrin and dynamin expression was measured by Western blot. Cellular uptake of TiO2 NPs occurred early after 30 min exposure, and large aggregates were observed after 1 h. Actin cytoskeleton reorganization included cell elongation plus lower density and stability of actin fibers. Cytochalasin-D inhibited TiO2 NPs uptake, indicating actin-mediated internalization. Dynamin and clathrin levels increased early after TiO2 NPs exposure, and their inhibition reduced nanoparticle uptake. Therefore, TiO2 NPs internalization by H9c2 rat cardiomyoblasts involves actin cytoskeleton reorganization and clathrin/dynamin-mediated endocytosis.
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| 7. |
- Quintana-Belmares, Raúl Omar, et al.
(author)
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Phthalate esters on urban airborne particles : Levels in PM10 and PM2.5 from Mexico City and theoretical assessment of lung exposure
- 2018
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In: Environmental Research. - : Elsevier BV. - 0013-9351 .- 1096-0953. ; 161, s. 439-445
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Journal article (peer-reviewed)abstract
- Endocrine disrupting chemicals (EDCs) from the environment are associated with reproductive abnormalities (i.e. decreased sperm concentration; increased endometriosis) and alterations of the cardiovascular system (i.e. increased blood pressure and risk of coronary disease). Some phthalates esters have been identified as EDCs, for which inhalation is considered as one of the routes of exposure. However, only little is known regarding inhalational exposure to EDCs via urban airborne particles. In the present study, we report the monthly concentration of 8 phthalate esters measured in PM10 and PM2.5 collected and recovered during 7 months in a highly populated area of Mexico City. Using the levels of PM10 and PM2.5 reported by the automatized network of environmental monitoring of Mexico City for the sampling site, we estimated exposure levels for people of different ages and gender. Two endocrine disrupting compounds, the phthalate esters DEHP and DnBP, were found on the particles in higher concentrations during the warmer months of the year. The highest concentration was reported for DEHP (229.7 mu g/g of particles) in PM2.5 collected in May 2013. After calculations of the DEHP concentration in the atmosphere, and using the respiratory flow rate, we determined males were potentially exposed to larger quantities of DEHP, reaching up to 18 ng/8 h in April 2013. Despite the concentrations of phthalates seem to be rather small, a comprehensive characterization of its presence is necessary in order to evaluate the overall exposure to these compounds, providing a clear view of exposure on children, adolescents and pregnant women.
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| 8. |
- Van Den Broucke, Sofie, et al.
(author)
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Contribution of mast cells in irritant-induced airway epithelial barrier impairment in vitro
- 2020
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In: Toxicology and industrial health. - : Sage Publications. - 0748-2337 .- 1477-0393. ; 36:10, s. 823-834
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Journal article (peer-reviewed)abstract
- The airway epithelium is continuously exposed to environmental irritants, which can cause adverse effects such as irritant-induced asthma (IIA). Mast cells are located near airway epithelia and are able to respond to a variety of stimuli. We aimed to investigate whether mast cells influence the response of the epithelium upon irritant exposure. Two cell lines and three different seeding conditions, that is, bronchial epithelial cells (16HBE) only, 16HBE with mast cells (HMC-1's) basolaterally, and 16HBE with HMC-1's apically, were established. Upon exposure to the environmental irritants, graphene (G), graphene oxide (GO), diesel exhaust particles (DEPs) or hypochlorite (ClO-), transepithelial electrical resistance (TEER) and paracellular flux of fluorescent-labeled dextrans were determined, along with the release of mediators. Identical experiments were conducted with the Ca2+ ionophore ionomycin. Exposure to G and GO induced a significant and permanent decrease of approximately 70% in TEER after 3 h of exposure, whereas DEP and ClO- exposure resulted in a transient decrease of approximately 20% in TEER. This response pattern was similar in all the different seeding conditions. After 24 h of exposure, fluorescein isothiocyanate-dextran transport was 10-fold greater for G and 5-fold greater for GO in each of the tested seeding conditions, while DEP and ClO- induced no change compared to the control. Upon exposure to the irritants, 16HBE did not release thymic stromal lymphopoietin, interleukin 33 (IL-33), or IL-1α, and HMC-1 cells did not release histamine, IL-6, or IL-8. Epithelial barrier integrity upon treatment with ionomycin was not affected by the presence of HMC-1 cells. A limited amount of IL-6 and IL-8 was released by ionomycin-exposed HMC-1 cells. To conclude, we found that the studied environmental irritants do not directly or indirectly activate HMC-1 cells. These mast cells did not influence the epithelial barrier function upon environmental exposure, and thus currently do not provide additional information for the underlying mechanism of IIA.
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| 9. |
- Åkerlund, Emma, et al.
(author)
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Inflammation and (secondary) genotoxicity of Ni and NiO nanoparticles
- 2019
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In: Nanotoxicology. - : Taylor & Francis. - 1743-5390 .- 1743-5404. ; 13:8, s. 1060-1072
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Journal article (peer-reviewed)abstract
- Nanoparticle-induced genotoxicity can arise through different mechanisms, and generally, primary and secondary genotoxicity can be distinguished where the secondary is driven by an inflammatory response. It is, however, yet unclear how a secondary genotoxicity can be detected using in vitro methods. The aim of this study was to investigate inflammation and genotoxicity caused by agglomerated nickel (Ni) and nickel oxide (NiO) nanoparticles and, furthermore, to explore the possibility to test secondary (inflammation-driven) genotoxicity in vitro. As a benchmark particle to compare with, we used crystalline silica (quartz). A proteome profiler antibody array was used to screen for changes in release of 105 different cytokines and the results showed an increased secretion of various cytokines including vascular endothelial growth factor (VEGF) following exposure of macrophages (differentiated THP-1 cells). Both Ni and NiO caused DNA damage (comet assay) following exposure of human bronchial epithelial cells (HBEC) and interestingly conditioned media (CM) from exposed macrophages also resulted in DNA damage (2- and 3-fold increase for Ni and NiO, respectively). Similar results were also found when using a co-culture system of macrophages and epithelial cells. In conclusion, this study shows that it is possible to detect a secondary genotoxicity in lung epithelial cells by using in vitro methods based on conditioned media or co-cultures. Further investigation is needed in order to find out what factors that are causing this secondary genotoxicity and whether such effects are caused by numerous nanoparticles.
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