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1.
Environ Res ; 216(Pt 3): 114736, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36343713

RESUMEN

In welding, there is a potential risk due to metal-oxide nanoparticles (MONPs) exposure of workers. To investigate this possibility, the diameter and number particles concentration of MONPs were evaluated in different biological matrices and in personal air samples collected from 18 stainless-steel welders and 15 unexposed administrative employees engaged in two Italian mechanical engineering Companies. Exhaled breath condensate (EBC) and urine were sampled at pre-shift on 1st day and post-shift on 5th day of the workweek, while plasma and inhalable particulate matter (IPM) at post-shift on 5th day and analysed using the Single Particle Mass Spectrometry (SP-ICP-MS) technique to assess possible exposure to Cr2O3, Mn3O4 and NiO nanoparticles (NPs) in welders. The NPs in IPM at both Companies presented a multi-oxide composition consisting of Cr2O3 (median, 871,574 particles/m3; 70 nm), Mn3O4 (median, 713,481 particles/m3; 92 nm) and NiO (median, 369,324 particles/m3; 55 nm). The EBC of welders at both Companies showed Cr2O3 NPs median concentration significantly higher at post-shift (64,645 particles/mL; 55 nm) than at pre-shift (15,836 particles/mL; 58 nm). Significantly lower Cr2O3 NPs median concentration and size (7762 particles/mL; 44 nm) were observed in plasma compared to EBC of welders. At one Company, NiO NPs median concentration in EBC (22,000 particles/mL; 65 nm) and plasma (8248 particles/mL; 37 nm) were detected only at post-shift. No particles of Cr2O3, Mn3O4 and NiO were detected in urine of welders at both Companies. The combined analyses of biological matrices and air samples were a valid approach to investigate both internal and external exposure of welding workers to MONPs. Overall, results may inform suitable risk assessment and management procedures in welding operations.


Asunto(s)
Contaminantes Ocupacionales del Aire , Nanopartículas , Exposición Profesional , Soldadura , Humanos , Acero Inoxidable/análisis , Obreros Metalúrgicos , Monitoreo Biológico , Exposición Profesional/análisis , Óxidos/análisis , Soldadura/métodos , Material Particulado/análisis , Compuestos Orgánicos/análisis , Contaminantes Ocupacionales del Aire/análisis , Monitoreo del Ambiente
2.
J Biol Chem ; 293(29): 11424-11432, 2018 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-29853641

RESUMEN

Cells form stress granules (SGs) upon stress stimuli to protect sensitive proteins and RNA from degradation. In the yeast Saccharomyces cerevisiae, specific stresses such as nutrient starvation and heat-shock trigger recruitment of the yeast pyruvate kinase Cdc19 into SGs. This RNA-binding protein was shown to form amyloid-like aggregates that are physiologically reversible and essential for cell cycle restart after stress. Cellular Cdc19 exists in an equilibrium between a homotetramer and monomer state. Here, we show that Cdc19 aggregation in vitro is governed by protein quaternary structure, and we investigate the physical-chemical basis of Cdc19's assembly properties. Equilibrium shift toward the monomer state exposes a hydrophobic low-complexity region (LCR), which is prone to induce intermolecular interactions with surrounding proteins. We further demonstrate that hydrophobic/hydrophilic interfaces can trigger Cdc19 aggregation in vitro Moreover, we performed in vitro biophysical analyses to compare Cdc19 aggregates with fibrils produced by two known dysfunctional amyloidogenic peptides. We show that the Cdc19 aggregates share several structural features with pathological amyloids formed by human insulin and the Alzheimer's disease-associated Aß42 peptide, particularly secondary ß-sheet structure, thermodynamic stability, and staining by the thioflavin T dye. However, Cdc19 aggregates could not seed aggregation. These results indicate that Cdc19 adopts an amyloid-like structure in vitro that is regulated by the exposure of a hydrophobic LCR in its monomeric form. Together, our results highlight striking structural similarities between functional and dysfunctional amyloids and reveal the crucial role of hydrophobic/hydrophilic interfaces in regulating Cdc19 aggregation.


Asunto(s)
Amiloide/metabolismo , Proteínas de Ciclo Celular/metabolismo , Piruvato Quinasa/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Enfermedad de Alzheimer/metabolismo , Amiloide/química , Amiloide/ultraestructura , Péptidos beta-Amiloides/metabolismo , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/ultraestructura , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Insulina/metabolismo , Fragmentos de Péptidos/metabolismo , Agregado de Proteínas , Estructura Cuaternaria de Proteína , Piruvato Quinasa/química , Piruvato Quinasa/ultraestructura , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/ultraestructura , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/ultraestructura
3.
Soft Matter ; 15(39): 7888-7900, 2019 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-31532443

RESUMEN

The possibility to invert emulsions from oil-in-water to water-in-oil (or vice versa) in a closed system, i.e. without any formulation change, remains an open fundamental challenge with many opportunities for industrial applications. Here, we propose a mechanism that exploits particle surface roughness to induce metastable wetting and obtain mechanically-responsive Pickering emulsions. We postulate that the phase inversion is driven by an in situ switch of the particle wettability from metastable positions at the interface following the input of controlled mechanical energy. Oil-in-water emulsions can be prepared at low energy using mildly hydrophobic rough colloids, which are dispersed in water and weakly pinned at the interface, and switched to water-in-oil emulsions by a second emulsification at higher energy, which triggers the relaxation of the particle contact angle. The same principle is demonstrated for the complementary emulsions using mildly hydrophilic colloids initially dispersed in oil. Our experiments and simulations support that the delicate interplay between particle surface design during synthesis and the energy of the emulsification process can encode a kinetic pathway for the phase inversion. Both organic and inorganic nanoparticles can be used, allowing for the future implementation of our strategy in a broad range of smart industrial formulations.

4.
Epidemiol Prev ; 43(4): 260-269, 2019.
Artículo en Italiano | MEDLINE | ID: mdl-31650781

RESUMEN

BACKGROUND: the assessment of individual exposure to toxicants in industrially contaminated areas is difficult when multiple productions are actively close to residential areas. Two thermoelectric power plants (one recently converted to coal) and a large harbour have been operating since the Sixties in the area of Civitavecchia (North of Rome, Lazio Region, Central Italy). Detailed exposure assessment of pollutants from industrial sources, heating (biomass combustion), and urban traffic were not available. OBJECTIVES: to assess the individual exposure of residents by using both dispersion models and human biomonitoring. DESIGN: cross-sectional study. SETTING AND PARTICIPANTS: residents in the area of Civitavecchia since 2001 aged 35-69 years were enrolled and their addresses were geocoded. Exposure assessment to power plants emissions (PM10), traffic (NOx), harbour (PM10), and biomass burning (PM10) was performed at individual residential address using Lagrangian dispersion models. The "Ambiente e Biomarcatori a Civitavecchia" study (Environment and biomarkers in Civitavecchia - ABC study) made available urinary concentrations of metals (i.e., Cd, Pt, W, Pd, Hg, Tl, Cr, Pd, Ni, As) in a sample of residents, while information on personal characteristics, lifestyles, work history, clinical history, and use of drugs was collected by interview. MAIN OUTCOME MEASURES: for each metal, a linear regression analysis was implemented to study the association between its log-transformed values (adjusted for urinary creatinine) and the linear terms of the estimated pollutants concentrations, adjusted for age, gender, period, and other risk factors (i.e., educational level, smoking habit, alcohol, BMI). Geometric Mean Ratios (GMR) and the corresponding confidence intervals (95%CI) were computed. RESULTS: in the ABC sample of 1,141 residents (42% male, mean age 53.5 years, SD 9.7), there was a positive association between PM10 from power plants and urinary cadmium (Cd) (GMR: 1.12; 95%CI 1.00-1.25), traffic pollution (NOx) and platinum (Pt) (GMR: 1.17; 95%CI 1.00-1.38), PM10 from biomass burning and Cd (GMR: 1.14; 95%CI 1.05-1.24), and tungsten (W) (GMR: 1.19; 95%CI 1.03-1.37) and palladium (Pd) (GMR: 1.11; 95%CI 1.00-1.23). Other associations observed did not reach statistical significance. CONCLUSIONS: although it may not be said that dispersion models can replace biomonitoring studies, they certainly represent an excellent tool for exposure assessment and, therefore, they may be used for the estimation of the individual exposure of populations living in industrially contaminated areas.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo Biológico , Exposición a Riesgos Ambientales/análisis , Modelos Teóricos , Centrales Eléctricas , Adulto , Anciano , Estudios Transversales , Femenino , Humanos , Italia , Masculino , Persona de Mediana Edad
5.
Langmuir ; 33(49): 14038-14044, 2017 12 12.
Artículo en Inglés | MEDLINE | ID: mdl-29151350

RESUMEN

Surface chemistry is believed to be the key parameter affecting the aggregation and breakage of colloidal suspensions when subjected to shear. To date, only a few works dealt with the understanding of the role of the physical and chemical properties of the particles' surface upon aggregation under shear. Previous studies suggested that surface modifications strongly affect polymer particles' adhesion, but it was very challenging to demonstrate this effect and monitor these alterations upon prolonged exposure to shear forces. More importantly, the mechanisms leading to these changes remain elusive. In this work, shear-induced aggregation experiments of polymer colloidal particles have been devised with the specific objective of highlighting material transfer and clarifying the role of the softness of the particle's surface. To achieve this goal, polymer particles with a core-shell structure comprising fluorescent groups have been prepared so that the surface's softness could be tuned by the addition of monomer acting as a plasticizer and the percentage of fluorescent particles could be recorded over time via confocal microscopy to detect eventual material transfer among different particles. For the first time, material exchange occurring on the soft surface of core-shell polymer microparticles upon aggregation under shear was observed and proved. More aptly, starting from a 50% labeled/nonlabeled mixture, an increase in the percentage of particles showing a fluorescent signature was recorded over time, reaching a fraction of 70% after 5 h.

6.
Toxics ; 11(2)2023 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-36850996

RESUMEN

Advances in nanotechnology have led to an increased use of engineered nanoparticles (ENPs) and the likelihood for occupational exposures. However, how to assess such exposure remains a challenge. In this study, a methodology for human biomonitoring, based on Single Particle Inductively Coupled Plasma Mass Spectrometry (SP-ICP-MS), was developed as a tool to assess the ENPs exposure of workers involved in nanomaterial activities in two Italian Companies. The method was validated for size and number concentration determination of Ag, Au, In2O3, Ir, Pd, Pt, and TiO2 NPs in urine and blood samples. The results showed the presence of In2O3 NPs in blood of exposed workers (mean, 38 nm and 10,371 particles/mL), but not in blood of controls. Silver, Au, and TiO2 NPs were found in urine (mean, Ag 29 nm and 16,568 particles/mL) or blood (mean, Au 15 nm and 126,635 particles/mL; TiO2 84 nm and 27,705 particles/mL) of workers, though these NPs were found also in controls. The presence of ENPs in both workers and controls suggested that the extra-professional exposure is a source of ENPs that cannot be disregarded. Iridium, Pd, and Pt NPs were not detected neither in blood nor in urine. Overall, the findings provided a rational basis to evaluate the exposure assessment to ENPs in cohorts of workers as part of risk assessment and risk management processes in workplaces.

7.
J Transl Med ; 9: 69, 2011 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-21592382

RESUMEN

BACKGROUND: The HPV16 E7 protein is both a tumour-specific and a tumour-rejection antigen, the ideal target for developing therapeutic vaccines for the treatment of HPV16-associated cancer and its precursor lesions. E7, which plays a key role in virus-associated carcinogenesis, contains 98 amino acids and has two finger-type structures which bind a Zn++ ion. The ability of an Escherichia coli-produced E7-preparation, assembled into particles, to induce protective immunity against a HPV16-related tumour in the TC-1-C57BL/6 mouse tumour model, was evaluated. METHODS: E7 was expressed in E. coli, purified via a one-step denaturing protocol and prepared as a soluble suspension state after dialysis in native buffer. The presence in the E7 preparation of particulate forms was analysed by non-reducing SDS-PAGE and negative staining electron microscopy (EM). The Zn++ ion content was analysed by mass-spectrometry. Ten µg of protein per mouse was administered to groups of animals, once, twice or three times without adjuvant. The E7-specific humoral response was monitored in mice sera using an E7-based ELISA while the cell-mediated immune response was analysed in mice splenocytes with lymphoproliferation and IFN-γ ELISPOT assays. The E7 immunized mice were challenged with TC-1 tumour cells and the tumour growth monitored for two months. RESULTS: In western blot analysis E7 appears in multimers and high molecular mass oligomers. The EM micrographs show the protein dispersed as aggregates of different shape and size. The protein appears clustered in micro-, nano-aggregates, and structured particles. Mice immunised with this protein preparation show a significant E7-specific humoral and cell-mediated immune response of mixed Th1/Th2 type. The mice are fully protected from the tumour growth after vaccination with three E7-doses of 10 µg without any added adjuvant. CONCLUSIONS: This report shows that a particulate form of HPV16 E7 is able to induce, without adjuvant, an E7-specific tumour protection in C57BL/6 mice. The protective immunity is sustained by both humoral and cell-mediated immune responses. The E. coli-derived HPV16 E7 assembled in vitro into micro- and nanoparticles represents not only a good substrate for antigen-presenting cell uptake and processing, but also a cost-effective means for the production of a new generation of HPV subunit vaccines.


Asunto(s)
Inmunidad/inmunología , Neoplasias/inmunología , Neoplasias/prevención & control , Proteínas E7 de Papillomavirus/administración & dosificación , Proteínas E7 de Papillomavirus/inmunología , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/inmunología , Adyuvantes Inmunológicos , Animales , Formación de Anticuerpos/inmunología , Western Blotting , Modelos Animales de Enfermedad , Inmunidad Celular/inmunología , Ratones , Ratones Endogámicos C57BL , Proteínas E7 de Papillomavirus/química , Proteínas E7 de Papillomavirus/ultraestructura , Proteínas Recombinantes/química
8.
Toxicol Ind Health ; 26(3): 183-9, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20176776

RESUMEN

This study determined the distribution in internal organs and the elimination routes in rats after oral administration of potassium hexachloro-palladate. Forty male Wistar rats were exposed for 90 days to 0, 10, 100 and 250 ng/mL of the palladium (Pd) salt in drinking water. Samples of urine and feces were collected on days 1, 30, 60 and 90, while organs (kidney, liver, lung, spleen and bones) and blood were collected at the end of the experiment. Quantification method was based on the sector-field inductively coupled plasma mass spectrometry. Results indicated that Pd ions were rapidly eliminated from the body. The principal excretion was through the feces (650 +/- 72.7 ng/g dry weight, at the Pd dose of 250 ng/mL), but at the higher dosing Pd was also eliminated through the urine (6.16 +/- 1.91 ng/mL for the Pd intake of 250 ng/mL). A clear relationship between the Pd ingested dose and the Pd excretion amount was observed mainly in the feces. Absorbed Pd was mostly found in the kidney of rats (124.4 +/- 23.0 ng/g dry weight, following the highest dose), while liver, lung, spleen and bones did not accumulate the metal. At the higher dosing, Pd content in the kidney raised proportionally with the Pd dose. Our findings may be useful to help in the understanding of the health impact of Pd dispersed in the environment as well as in identifying appropriate biological indices of Pd exposure.


Asunto(s)
Paladio/farmacocinética , Administración Oral , Animales , Análisis Químico de la Sangre , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Heces/química , Masculino , Paladio/administración & dosificación , Paladio/sangre , Paladio/orina , Ratas , Ratas Wistar , Distribución Tisular
9.
Artículo en Inglés | MEDLINE | ID: mdl-31277284

RESUMEN

To remove the mineral oil impregnating the insulating paper present in old, disconnected, underground electrical cables, which represents a threat to the environment, two approaches are investigated at laboratory (1 m) and pilot (10 m) scales. The first one involves in situ polymerization to clog the inner channel of the cables and to enable the washing of the outer paper region impregnated by the oil by axial flow of a displacing fluid (water). The second approach leaves the inner channel open and employs repeated cycles of pressurization and rest to displace the oil contained in the paper by radially pushing the water from the inner channel into the outer layers. The pressurization and rest times were optimized to obtain the highest oil extraction rate. While the first approach showed limitations in terms of required pressures and operating time, which increase with the length of the cables, the second one was effective at removing 97% of the oil impregnating the paper layers within 25 cycles. Even more relevant, this second solution, in contrast to the first one, can be easily scaled up as it does not depend on the length of the cable, and was successfully tested on a 10 m cable, showing 98% oil recovery.


Asunto(s)
Fuentes Generadoras de Energía , Restauración y Remediación Ambiental , Aceite Mineral , Electricidad , Polimerizacion
10.
Eur J Pharm Biopharm ; 137: 23-36, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30779978

RESUMEN

The use of nanomaterials is increasing but the real risk associated with their use in humans has to be defined. In fact, nanomaterials tend to accumulate in organs over a long period of time and are slowly degraded or eliminated by the body. Exosomes are nanovesicles actively shuttle molecules, including chemical products and metals, through the body. Macrophages scavenge the body from both organic and inorganic substances, and they use to release high amounts of exosomes. We hypothesized that macrophages may have a role in eliminating nanomaterials through their exosomes. We treated human primary macrophages with 20 nm gold nanoparticles (AuNPs), analyzing the presence of AuNPs in both cells and the released exosomes by the implementation of different techniques, including SP-ICP-MS and NTA. We showed that macrophages endocytosed AuNPs and released them through exosomes. Our study on one hand provide the evidence for a new methodology in the early identification of the nanomaterials levels in exposed subjects. On the other hand we depict a way our body shuttle virtually intact nanoparticles through macrophage-released exosomes.


Asunto(s)
Exosomas/metabolismo , Oro/química , Macrófagos/metabolismo , Nanopartículas del Metal/análisis , Células Cultivadas , Humanos , Espectrometría de Masas/métodos , Nanopartículas del Metal/administración & dosificación
11.
Chemosphere ; 71(3): 568-73, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17980403

RESUMEN

The use of iridium in the latest catalytic converters to further reduce nitrogen oxide emission in the exhaust of lean-burn engines could result in increased atmospheric levels of this element in high-density vehicle traffic areas. The objective of this study is to assess environmental Ir pollution and its urinary levels in workers and an urban control group. Environmental monitoring inside a tram consisted in air samplings of total suspended particles (TSP), PM10 and PM2.5 carried out during November 2005. Urinary Ir levels were evaluated in 64 municipal tram drivers and in 58 administrative employees as controls. Quantification of Ir in air samples and urine was performed by means of Sector Field Inductively Coupled Plasma Mass Spectrometry. Means+/-standard deviation of Ir levels in TSP, in PM10 and PM2.5 fractions were 1.43+/-1.66, 0.44+/-0.27 and 0.36+/-0.19 pg m(-3), respectively. No statistically significant differences were observed among urinary Ir values in the exposed subjects and control group. The Ir levels in Rome air are still sufficiently low, even if the increased use of new Ir-based catalysts could be of some concern in the near future. The results of our study are of interest as they are a first attempt to explore airborne levels and urinary concentrations of Ir in an urban context at medium-high density of vehicle traffic. Particular attention should be given to the fact that Ir was found in the finest dust particles as the effects of fine particles containing Ir have not yet been studied.


Asunto(s)
Contaminantes Atmosféricos/análisis , Iridio/análisis , Exposición Profesional/análisis , Adulto , Contaminantes Atmosféricos/orina , Monitoreo del Ambiente , Humanos , Iridio/orina , Masculino , Persona de Mediana Edad , Ciudad de Roma , Transportes , Emisiones de Vehículos
12.
Nanomaterials (Basel) ; 8(11)2018 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-30413021

RESUMEN

Safety concerns related to the use of potentially explosive, liquid organic electrolytes in commercial high-power lithium-ion batteries are constantly rising. One promising alternative is to use thermally stable ionic liquids (ILs) as conductive media, which are however, limited by low ionic conductivity at room temperature. This can be improved by adding fillers, such as silica or alumina nanoparticles (NPs), in the polymer matrix that hosts the IL. To maximize the effect of such NPs, they have to be uniformly dispersed in the matrix while keeping their size as small as possible. In this work, starting from a water dispersion of silica NPs, we present a novel method to incorporate silica NPs at the nanoscale level (<200 nm) into PVdF-HFP polymer clusters, which are then blended with the IL solution and hot-pressed to form separators suitable for battery applications. The effect of different amounts of silica in the polymer matrix on the ionic conductivity and cyclability of the separator is investigated. A membrane containing 10 wt.% of silica (with respect to the polymer) was shown to maximize the performance of the separator, with a room temperature ionic conductivity of of 1.22 mS cm - 1 . The assembled half-coin cell with LiFePO 4 and Li as the cathode and the anode exhibited a capacity retention of more than 80% at a current density of 2C and 60 ∘ C.

13.
Polymers (Basel) ; 10(10)2018 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-30961046

RESUMEN

Redispersible powders based on soft core-hard shell polymer particles can be used as additives in polymer-cement mortars. The role of this morphology on the spray-drying production of these powders and on the crack-bridging properties of the corresponding cement-based membranes is investigated. Different polymer latexes at high solid content with varied core-shell ratio, shell thickness and chemical composition (hardness) were prepared from styrene and 2-ethylhexyl acrylate monomers via semi-batch emulsion polymerization. The latexes were characterized in terms of size, composition, and glass transition temperature (T g ), and spray-dried to obtain redispersible polymer powders (RPPs) using poly (vinyl alcohol) and limestone powder as anti-caking agents. The polymer powders were mixed with a mortar mixture and redispersed in water to produce cement-based membranes, which were tested for crack-bridging properties at different temperatures. The results showed that it was not possible to spray-dry a dispersion of homogeneous polymer particles with T g of -25 ∘ C, unless these particles are protected by much harder (high T g ) shell. In particular, it was observed that a thicker shell improved the spray-ability, but lowered the crack-bridging properties of the produced membrane. A trade-off between these two was revealed to be the key for the optimal design of the polymer nanoparticles, as proven by the systematic study of the core-shell morphology reported in this work. The best compromise was shown to consist of particles larger than 300 nm, shell thickness of about 5 nm, and core-shell ratio of 97%, with styrene content in the shell not larger than 80% to avoid excessive hydrophobicity.

14.
Sci Total Environ ; 630: 922-930, 2018 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-29499547

RESUMEN

This study sought to develop analytical methods to characterize titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles (NPs), including the particle size distribution and concentration, in cream and spray sunscreens with different sun protection factor (SPF). The Single Particle Inductively Coupled Plasma-Mass Spectrometry (SP ICP-MS) was used as screening and fast method to determine particles size and number. The Asymmetric Flow-Field Flow Fractionation (AF4-FFF) as a pre-separation technique was on-line coupled to the Multi-Angle Light Scattering (MALS) and ICP-MS to determine particle size distributions and size dependent multi-elemental concentration. Both methods were optimized in sunscreens in terms of recovery, repeatability, limit of detection and linear dynamic range. Results showed that sunscreens contained TiO2 particles with an average size of ≤107 nm and also a minor number of ZnO particles sized ≤98 nm. The higher fraction of particles <100 nm was observed in sunscreens with SPF 50+ (ca. 80%); the lower percentage (12-35%) in sunscreens with lower SPF values. Also the higher TiO2 (up to 24% weight) and ZnO (ca. 0.25% weight) concentrations were found in formulations of SPF 50+. Creamy sunscreens could be considered safe containing TiO2 and ZnO NPs less than the maximum allowable concentration of 25% weight as set by the European legislation. On the contrary, spray products required additional considerations with regard to the potential inhalation of NPs. The developed methods can contribute to the actual demand for regulatory control and safety assessment of metallic NPs in consumers' products.

15.
J Chromatogr A ; 1538: 25-33, 2018 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-29370918

RESUMEN

A simple method for producing highly porous materials suitable for chromatographic applications is discussed. Starting from a dispersion of polymer core-shell nanoparticles (latex), micrometer sized clusters (100 µm) are produced via shear-induced Reactive Gelation. Thanks to their fractal structure, these aggregates exhibit highly porous structures, with pore size distribution ranging from 0.1 to several micrometers. The effect of different properties of the primary nanoparticles on the qualities of the final products is also investigated. Particle architecture, namely the ratio between the hard, highly crosslinked core, and the soft, poorly crosslinked shell, turned out to be the most important parameter to be tuned in order to obtain highly porous and mechanically resistant clusters. The final materials can be easily slurry-packed into conventional chromatographic columns. In comparison to other commercial stationary phases, these materials show not only much lower pressure drops at very high flow rates (i.e. <0.2 bar/cm at 6 mL/min), but also HETP profiles independent of fluid velocity when measured with tracers of sizes comparable to typical bio-macromolecules. Moreover, these materials, while offering the key advantage of being in a slurry form and thus easily packable and scalable, have a behavior that closely resembles that of monoliths, in which convective flow contribution dominates.


Asunto(s)
Técnicas de Química Analítica/instrumentación , Técnicas de Química Analítica/métodos , Cromatografía/instrumentación , Geles , Polímeros/química , Presión , Tamaño de la Partícula , Porosidad
16.
Polymers (Basel) ; 10(8)2018 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-30960776

RESUMEN

In the last decades bioresorbable and biodegradable polymers have gained a very good reputation both in research and in industry thanks to their unique characteristics. They are able to ensure high performance and biocompatibility, at the same time avoiding post-healing surgical interventions for device removal. In the medical device industry, it is widely known that product formulation and manufacturing need to follow specific procedures in order to ensure both the proper mechanical properties and desired degradation profile. Moreover, the sterilization method is crucial and its impact on physical properties is generally underestimated. In this work we focused our attention on the effect of different terminal sterilization methods on two commercially available poly(l-lactide-co-ε-caprolactone) with equivalent chemical composition (70% PLA and 30% PCL) and relatively similar initial molecular weights, but different chain arrangements and crystallinity. Results obtained show that crystallinity plays a key role in helping preserve the narrow distribution of chains and, as a consequence, defined physical properties. These statements can be used as guidelines for a better choice of the most adequate biodegradable polymers in the production of resorbable medical devices.

17.
Chemotherapy ; 53(5): 309-12, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17728538

RESUMEN

From his student days throughout his whole life, Paul Ehrlich tried hard to obtain 'chemotherapia specifica' for the harmless systemic therapy of infectious diseases. Given the poor therapeutic benefit obtained with cytotoxic therapeutic agents and empirical radiopharmaceuticals, so far used only for neoadjuvant and adjuvant treatments of cancer, we have tried to develop Paul Ehrlich's 'chemotherapia specifica' for safe and effective therapy of cancers in cigarette smokers. With the help of sector-field inductively coupled plasma mass spectrometry, we have tried to find the metabolic action of cigarette smoke constituents in the cancerous organ. On the basis of these results we are synthesizing pharmaceuticals and radiopharmaceuticals to purge the tobacco-constituent metabolic products that cause cancer. The purity, stability and chemical nature of the pharmaceuticals and radiopharmaceuticals required for therapy have been studied by chromatography and electrophoresis. The cancer specificity of the therapeutic agent has been examined by the total body distribution of its gamma- and beta-labelled species in solution. At present, a bladder cancer-specific therapeutic agent is being developed.


Asunto(s)
Quimioterapia/historia , Neoplasias/tratamiento farmacológico , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Historia del Siglo XX , Humanos , Neoplasias/patología , Neoplasias/radioterapia , Factores de Riesgo
18.
Sci Total Environ ; 358(1-3): 255-64, 2006 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-15972231

RESUMEN

Vehicular traffic is the main source of platinum group elements (PGEs) in highly populated urban areas like Buenos Aires where a traffic density of 1,500,000 vehicles day(-1) (corresponding to 7,500 vehicles km(-2)) is estimated. Since there is no information on the levels of PGEs in Buenos Aires, a pilot study was undertaken to ascertain the amount of two major PGEs, namely Pt and Rh, in the atmosphere of this city. To this end, 49 samples of PM-10 particulate matter were collected during 7 days in seven representative sampling sites located downtown Buenos Aires and spread over an area of about 30 km(2). The collection of particulate matter was performed on ash-free glass-fiber filters using high volume samplers with PM-10 sampling heads. Filters loaded with the particulate matter were subjected to microwave (MW)-assisted acid digestion using a combination of HNO(3), HF and HClO(4). The resulting solutions were evaporated and then diluted with 0.1 mol l(-1) HCl. Analyses were performed by sector field inductively coupled plasma-mass spectrometry (SF-ICP-MS) and special attention was paid to the control of mass interferences. Statistical analysis was performed on the experimental data obtained for the element concentrations taking also into account local meteorological data for the monitored period. The highest concentrations of Pt and Rh were detected at two sites (Hospital Alemán and Casa Rapallini) located in streets with traffic consisting mostly of passenger cars. The Pt content (in pg m(-3)) in airborne particulate matter was found to vary from 2.3 to 47.7, with a mean value of 12.9+/-7, and that of Rh from 0.3 to 16.8, with a mean value of 3.9+/-2.8. These concentrations are by far below the levels for which adverse health effects might be expected to occur, i.e., around 100 ng m(-3). On the other hand, monitoring of PGEs should be carried out in a systematic fashion to detect possible dramatic increases from today's levels.


Asunto(s)
Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Platino (Metal)/análisis , Rodio/análisis , Argentina , Ciudades , Monitoreo del Ambiente , Humanos , Salud Pública , Medición de Riesgo , Emisiones de Vehículos/análisis
19.
Ann Ist Super Sanita ; 52(4): 488-494, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27999217

RESUMEN

BACKGROUND: The assessment of individual exposure to toxicants in industrially contaminated areas is difficult when multiple productions are active close to residential areas. Two thermoelectric power plants and a large harbor have been operating since the '60s in the area of Civitavecchia (North of Rome). METHODS: The ABC (Ambiente e Biomonitoraggio nell'area di Civitavecchia, Environment and Biomonitoring in Civitavecchia) program involved, in the period 2013-2014, residents in Civitavecchia and in the nearby municipalities (Santa Marinella, Allumiere, Tolfa and Tarquinia). They were randomly selected from the Municipal Register's data and their residence addresses were geocoded using GIS techniques. Biomonitoring of the following urinary metals, Sb, Be, Mo, Cd, Sn, W, Ir, Pt, Hg, Tl, V, Cr, Mn, Co, Ni, Cu, Zn, Rh, Pd, As were performed. Glucose and lipid metabolism, liver, renal, and endocrine function were evaluated through blood laboratory tests. Tests of lung functionwere also carried out as well as saturometry (oxygen rate in the blood with an illuminated sensor placed on the fingertip), anthropometric and blood pressure measurements. Information on individual characteristics, histories of exposure, such as the consumption of local food, occupational history, lifestyle and medical history were collected through a validated questionnaire. Samples of nails and hair were also collected. The biological material (blood, urine, nails and hair) was stored in a biobank for future analysis related to the possible mechanisms of biological damage. The study protocol received the approval of the local ethics committee. RESULTS: A total of 1177 residents were enrolled (58% female, 60% with a secondary or graduate school degree). No particular differences in metal concentrations based on the municipality of residence were observed. For arsenic, mercury, lead, and tungsten some differences between the two geographical areas were observed, probably due to different diet, lifestyle (e.g., alcohol consumption, smoking, use of jewelry and piercings, tattoos, physical activity, hormonal and mineral supplements, and drugs), and occupational exposure. CONCLUSIONS: The undergoing study on the association between biomarkers concentration and pollutants concentrations - estimated using a dispersion modeling approach, and adjusting for personal characteristics and concomitant other environmental exposure - could clarify the individual exposure of the residents in this industrial area.


Asunto(s)
Exposición a Riesgos Ambientales/estadística & datos numéricos , Adulto , Anciano , Biomarcadores/orina , Monitoreo del Ambiente , Contaminantes Ambientales/análisis , Femenino , Humanos , Industrias , Italia , Estilo de Vida , Masculino , Metales/orina , Persona de Mediana Edad , Factores Socioeconómicos
20.
Ann Ist Super Sanita ; 41(2): 181-7, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16244391

RESUMEN

Reference values for 26 elements, namely Al, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Hg, Li, Mg, Mn, Mo, Ni, Pb, Sb, Si, Sn, Sr, Tl, V, W, Zn and Zr are proposed in serum and blood of 110 healthy adults of the urban area of Rome. They were included in the study on the basis of strict criteria of eligibility and exclusion. With the exception of Ba, Bi, Co, Cr, Ni, Sb, Sn Tl in serum, and Bi, Hg, Si, V and W in whole blood, experimental data for each all the other analytes were found to approach a normal distribution. The estimated 5-95% references ranges (in ng ml(-1)) were reported. For several elements the reference ranges observed overlapped information available in the literature. Gender, age, body mass index, smoking habits and alcohol consume were used as grouping variables. Mutual associations were observed for several elements, as follows: Be, Ca, Co, Cr, Cu, Li, Mo, Pb and Zn with sex; Ca, Pb and Si with age (< and > 45 years); Co, Cr, Mo, Sb and Tl with body mass index; Cd and Pb with smoking habit; Cr and Pb with alcohol consume.


Asunto(s)
Análisis Químico de la Sangre/normas , Elementos Químicos , Espectrometría de Masas , Valores de Referencia , Adulto , Sangre , Salud de la Familia , Femenino , Hábitos , Humanos , Italia , Masculino , Persona de Mediana Edad , Distribución Normal , Muestreo , Suero , Encuestas y Cuestionarios , Población Urbana
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