Search results for "Expo"
showing 10 items of 2430 documents
Amplitude, Latency, and Peak Velocity in Accommodation and Disaccommodation Dynamics
2017
The aim of this work was to ascertain whether there are differences in amplitude, latency, and peak velocity of accommodation and disaccommodation responses when different analysis strategies are used to compute them, such as fitting different functions to the responses or for smoothing them prior to computing the parameters. Accommodation and disaccommodation responses from four subjects to pulse changes in demand were recorded by means of aberrometry. Three different strategies were followed to analyze such responses: fitting an exponential function to the experimental data; fitting a Boltzmann sigmoid function to the data; and smoothing the data. Amplitude, latency, and peak velocity of …
Stable changes in CD4+ T lymphocyte miRNA expression after exposure to HIV-1
2012
Abstract MicroRNAs (miRNAs) inhibit HIV-1 expression by either modulating host innate immunity or by directly interfering with viral mRNAs. We evaluated the expression of 377 miRNAs in CD4+ T cells from HIV-1 élite long-term nonprogressors (éLTNPs), naive patients, and multiply exposed uninfected (MEU) patients, and we observed that the éLTNP patients clustered with naive patients, whereas all MEU subjects grouped together. The discriminatory power of miRNAs showed that 21 miRNAs significantly differentiated éLTNP from MEU patients and 23 miRNAs distinguished naive from MEU patients, whereas only 1 miRNA (miR-155) discriminated éLTNP from naive patients. We proposed that miRNA expression ma…
Reversible effect of magnetic fields on human lymphocyte activation patterns: different sensitivity of naive and memory lymphocyte subsets.
2009
The aim of this study was to investigate the influence of 50 Hz magnetic or static magnetic fields of 0.5 mT on subsets of human CD4(+) T cells in terms of cytokine release/content, cell proliferation and intracellular free calcium concentration. CD4(+) T cells can be divided into different subsets on the basis of surface marker expression, such as CD45, and T cells can be divided into naive (CD45RA(+)) and memory (CD45RA(-)) cells. In this study, the effects of magnetic fields after 24 and 48 h of cell culture were analyzed. We found that the CD4(+)CD45RA(-) T subset were more sensitive after 2 h of exposure. Decreases in the release/content of IFN-gamma, in cell proliferation and in intra…
Cancer consequences of the Chernobyl accident in Europe outside the former USSR: A review
1996
The accident which occurred during the night of April 25-26, 1986 in reactor 4 of the Chernobyl nuclear power plant in the Ukraine released considerable amounts of radioactive substances into the environment. Outside the former USSR, the highest levels of contamination were recorded in Bulgaria, Austria, Greece and Romania, followed by other countries of Central, Southeast and Northern Europe. Studies of the health consequences of the accident have been carried out in these countries, as well as in other countries in Europe. This report presents the results of a critical review of cancer studies of the exposed population in Europe, carried out on the occasion of the 10th anniversary of the …
Acute effects on the human EEG after an external exposure to 200 ppm methanol
2001
Objectives: Even low concentrations of organic solvents may cause acute effects on the human central nervous system. The German MAK (threshold limit value) of methanol is 200 ppm. The aim of this study was to investigate whether acute exposure to 200 ppm methanol causes adverse effects, measured by EEG, and moreover, whether it is possible to differentiate between sedative and excitatory effects with this method. Methods: Twelve healthy subjects were exposed for 4 h to 200 ppm and to 20 ppm (control) in an exposure chamber in a cross-over design. The EEG was recorded before (reference) and at the end of each exposure with, the subject's eyes closed and opened and during a choice reaction te…
Mechanical–biological waste treatment and the associated occupational hygiene in Finland
2004
A special feature of waste management in Finland has been the emphasis on the source separation of kitchen biowaste (catering waste); more than two-thirds of the Finnish population participates in this separation. Source-separated biowaste is usually treated by composting. The biowaste of about 5% of the population is handled by mechanical-biological treatment. A waste treatment plant at Mustasaari is the only plant in Finland using digestion for kitchen biowaste. For the protection of their employees, the plant owners commissioned a study on environmental factors and occupational hygiene in the plant area. During 1998-2000 the concentrations of dust, microbes and endotoxins and noise level…
Human exposure and risk assessment to airborne pesticides in a rural French community
2016
Abstract Outdoor air samples collected during the pesticide agricultural application period (spring and summer) from a rural community in the Centre Region (France) were analyzed to investigate temporal variation of atmospheric pesticide levels (2006–2013) and human inhalation exposure in adults, children and infants. The most frequently detected pesticides were herbicides (trifluralin, pendimethalin), fungicides (chlorothalonil) and insecticides (lindane and α-endosulfan). The three currently-used pesticides most frequently detected presented concentrations ranging from 0.18 to 1128.38 ng m − 3 ; 0.13 to 117.32 ng m − 3 and 0.16 to 25.80 ng m − 3 for chlorothalonil, pendimethalin and trifl…
Biomonitoring of non-persistent pesticides in urine from lactating mothers: Exposure and risk assessment
2019
Abstract The aim of the present study was to assess the exposure to pesticides in urine from Spanish lactating mothers (n = 116). Six nonspecific (dialkyl phosphates) and 20 specific metabolites of organophosphate pesticides (OPs), herbicides and pyrethroids were analyzed. The most frequently detected biomarkers were diethyl phosphate, p-nitrophenol, 3,5,6-trichloro-2-pyridinol and 3-phenoxybenzoic acid, whose geometric means were 1.9 ng·mL−1, 0.8 ng·mL−1, 1.5 ng·mL−1 and 1.4 ng·mL−1, respectively. Herbicide metabolites were the least frequently detected biomarkers with detection frequencies between 0% (2,4,5-Trichlorophenoxyacetic acid) and 22% (2,4-Dichlorophenoxyacetic acid). Multiple re…
Concentrations and determinants of organochlorine levels among pregnant women in Eastern Spain
2010
Persistent organic pollutants (POPs) comprise a large variety of toxic substances with ample distribution. While exposure to these toxins occurs mainly through diet, maternal POP levels may be influenced by certain sociodemographic, environmental, or lifestyle factors. This is important given that these substances may have adverse effects on fetal development. The aim of this study is to examine the sociodemographic, environmental, lifestyle, and dietary determinants of the levels of hexachlorobenzene (HCB), b-hexachlorocyclohexane (b-HCH), 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (4,4′-DDT), 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (4,4′-DDE), and polychlorinated biphenyls (PCB co…
Risk assessment of exposure to phthalates in breastfeeding women using human biomonitoring
2020
In this study, we assessed the presence of 14 phthalate metabolites in the urine of 104 lactating mothers from Valencia (Spain) who took part in the human biomonitoring project BETTERMILK. Nine of the metabolites studied showed detection frequencies >80%, whereas the rest of the metabolites presented low detection frequencies (<5%). The concentrations ranged from <LoQ to 1291 ng/mL with monoethyl phthalate showing the highest concentration, with a geometric mean of 34.90 ng/mL. In general, the phthalate metabolite levels quantified in the present study were lower than the urinary levels found in previous studies that involved lactating mothers. The consumption of packaged juices and the fre…