RESUMEN
Microplastics are found in marine and freshwater environments; however, their specific sources are not yet well understood. Understanding sources will be of key importance in efforts to reduce emissions into the environment. We examined the emissions of microfibers from domestic washing of a new microfiber polyester fleece textile. Analyzing released fibers collected with a 200 µm filter during 10 mild, successive washing cycles showed that emission initially decreased and then stabilized at approx. 0.0012 wt%. This value is our estimation for the long-term release of fibers during each washing. Use of detergent and softener did not significantly influence emission. Release of fibers during tumble drying was approx. 3.5 times higher than during washing.
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Plásticos/análisis , Textiles/análisis , Contaminantes Químicos del Agua/análisis , Monitoreo del AmbienteRESUMEN
The trade-off between performance and complexity of the device manufacturing process should be balanced to enable the economic harvest of solar energy. Here, we demonstrate a conceptual, yet practical and well-regulated strategy to achieve efficient solar photocatalytic activity in TiO2 through controlled phase transformation and disorder engineering in the surface layers of TiO2 nanotubes. This approach enabled us to fine-tune the bandgap structure of undoped TiO2 according to our needs while simultaneously obtaining robust separation of photo-excited charge carriers. Introduction of specific surface defects also assisted in utilization of the visible part of sunlight to split water molecules for the production of oxygen. The strategy proposed here can serve as a guideline to overcome the practical limitation in the realization of efficient, non-toxic, chemically stable photoelectrochemical systems with high catalytic activity at neutral pH under visible illumination conditions. We also successfully incorporated TiO2 nanotube arrays (TNTAs) with free-based porphyrin affording a pathway with an overall 140% enhanced efficiency, an oxygen evolution rate of 436 µL h(-1) and faradic efficiencies over 100%.
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Thin-film dye-sensitized solar cells (DSCs) based on mesoporous semiconductor electrodes are low-cost alternatives to conventional silicon devices. High-efficiency DSCs typically operate as photoanodes (n-DSCs), where photocurrents result from dye-sensitized electron injection into n-type semiconductors. Dye-sensitized photocathodes (p-DSCs) operate in an inverse mode, where dye-excitation is followed by rapid electron transfer from a p-type semiconductor to the dye (dye-sensitized hole injection). Such p-DSCs and n-DSCs can be combined to construct tandem solar cells (pn-DSCs) with a theoretical efficiency limitation well beyond that of single-junction DSCs (ref. 4). Nevertheless, the efficiencies of such tandem pn-DSCs have so far been hampered by the poor performance of the available p-DSCs (refs 3, 5-15). Here we show for the first time that p-DSCs can convert absorbed photons to electrons with yields of up to 96%, resulting in a sevenfold increase in energy conversion efficiency compared with previously reported photocathodes. The donor-acceptor dyes, studied as photocathodic sensitizers, comprise a variable-length oligothiophene bridge, which provides control over the spatial separation of the photogenerated charge carriers. As a result, charge recombination is decelerated by several orders of magnitude and tandem pn-DSCs can be constructed that exceed the efficiency of their individual components.
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The timely restructuring of healthcare at water transport is an issue of special importance under the social-and-economic conditions of today. The paper mirrors positive and negative aspects of the present state medical care provided to those occupied at water transport system of the North-West Okrug of the Russian Federation. The virtually identical standard of medical care rendered to the discussed category of employees is observed in other Okrugs of Russia. A model of medical care for seamen for the at-sea and on-shore conditions is put forward. In order to preserve and to promote the discussed sphere of healthcare it is necessary to preserve the positive traditions of the past and, jointly with the interested branches, departments and public and other organizations, to apply the modern methods healthcare organization, i.e. to reorganize some of the sectors, to introduce a strict Register of institutions and organizations preoccupied with medical are at water transport and to develop and to introduce new technologies in all spheres of medical care within the branch.
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Atención a la Salud/normas , Reforma de la Atención de Salud , Personal Militar , Medicina Naval/normas , Humanos , Masculino , Medicina Naval/economía , Federación de Rusia , Factores SocioeconómicosRESUMEN
Bimolecular charge carrier recombination has been clarified in bulk-heterojunction solar cells based on a blend of regioregular poly(3-hexylthiophene) and 1-(3-methoxycarbonyl)propyl-1-phenyl-[6,6]-methanofullerene using the time-of-flight method. We show how bimolecular recombination influences the charge carrier transport, how it limits the efficiency of low-mobility solar cells, and how to estimate the bimolecular recombination coefficient. We found that bimolecular recombination in these efficient photovoltaic materials is orders of magnitude slower as compared to Langevin recombination expected for low-mobility materials. This effect is inherent to the nanomorphology of the bicontinuous interpenetrating network creating separate pathways for electrons and holes, and paves the way for the fabrication of bulk-heterojunction solar cells where bimolecular recombination is not the limiting factor.
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BACKGROUND: Merchant seafaring often involves hazardous occupational operations and several studies have shown increased overall injury mortality. The aim of this study was to describe the risks involved in slip, trip and fall (STF) injuries in merchant seafaring, in order to point out areas for prevention. METHODS: A questionnaire study was carried out in 11 countries with 6,461 participants. The seafarers gave information on whether they were injured during their latest tour of duty, and whether STF preceded the injury. RESULTS: Of the total reported injuries 43% (n=467) were STF related. Fractures and sprains accounted for 42% of the STF injuries compared with 17% for non-STF injuries. The proportions of STF injuries for different types of ships and areas of the ships varied from < 30% to >60%, particularly work on passenger ship decks, where STF injuries were >60%. The proportions of STF injuries increased by age and by severity of the injury. CONCLUSIONS: Injuries related to STF on merchant ships were more frequent than previous estimates. There is a need for improvements in defining, reporting, and preventing STF injuries in merchant seafaring.
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Accidentes por Caídas/estadística & datos numéricos , Accidentes de Trabajo/estadística & datos numéricos , Navíos , Accidentes por Caídas/mortalidad , Accidentes de Trabajo/mortalidad , Adolescente , Adulto , Factores de Edad , Métodos Epidemiológicos , Humanos , Persona de Mediana EdadRESUMEN
Malignant osteopetrosis (MOP) is an autosomal recessive disease in which osteoclast dysfunction results in excessive bone deposition and early infant death. Thirteen children suffering from MOP from four related families all belonging to one Bedouin tribe, were studied. The disease was diagnosed as early as at a few days postnatal to 5 months. Nine children underwent BMT, four of whom are still alive; one is blind and two have markedly reduced vision. Four children who did not undergo BMT died between 4 and 6 months of age. Recently, the gene for MOP has been mapped for this Bedouin tribe allowing prenatal diagnosis. Seven pregnancies were subsequently prenatally diagnosed and two fetuses were found to be affected. Pregnancy was electively terminated in one case. In the other case the parents refused and after establishing the diagnosis, the newborn was transplanted at the age of 7 days.
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Trasplante de Células Madre Hematopoyéticas , Osteopetrosis/diagnóstico , Osteopetrosis/terapia , Diagnóstico Prenatal , Adulto , Femenino , Humanos , Recién Nacido , Masculino , EmbarazoRESUMEN
The course of ulcer disease (UD) in sailors of the North seas was analysed and compared to that in non-sailors. UD in sailors runs with less pronounced subjective symptoms, manifests at younger age, is frequently accompanied by duodenal mucosa erosions and duodenogastric reflux. The greatest number of UD exacerbations was observed in the first month in sea and two months after getting home. Because of the fear to lose the job the sailors often do not seek medical assistance in spite of ulcer symptoms and this results in many cases of late diagnosis.