Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Biol Futur ; 70(3): 218-239, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34554446

RESUMO

BACKGROUND AND AIMS: Betony (Betonica officinalis L.) is one of the rarest and most spectacular plants in the Scandinavian flora. A long-term question has been whether it is spontaneous or introduced, or whether it comprises both spontaneous and introduced populations. This study aimed to answer this question by analyzing sequence data from the nuclear external transcribed spacer (ETS) region and three regions of the plastid genome, the trnT-trnL intergenic spacer (IGS) region, tRNA-Leu (trnL) intron, and the trnS-trnG IGS. MATERIALS AND METHODS: Altogether 41 samples from 11 European countries were analyzed. A unique duplication in the trnT-trnL IGS was detected in material from Skåne (southern Sweden), the "Skåne-duplication." Populations with this duplication are united on a moderately supported branch in the phylogeny based on plastid sequences. A distinct heath genotype from Yorkshire was discovered in the phylogeny based on plastid sequences and in a comparative cultivation. RESULTS: Phylogeny based on ETS sequences does not support any Scandinavian group, whereas a principal coordinates analysis ordination based on variable ETS positions indicated a spontaneous origin for all Scandinavian populations, which comprise a genetically well-defined subgroup of the species, most closely related to other spontaneous populations from adjacent parts of continental parts of northern Europe. DISCUSSION: Seven possible naturally occurring localities remain in Scandinavia, five in central Skåne, southernmost Sweden, and two on the southwestern part of the Danish island of Lolland.

2.
Chemosphere ; 203: 506-513, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29649692

RESUMO

Four different types of fuel blends containing demolition and construction wood and household waste were combusted in a small-scale experimental set-up to study the effect of fuel composition on the emissions of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), chlorobenzenes (PCBzs), chlorophenols (PCPhs) and polycyclic aromatic hydrocarbons (PAHs). Two woody materials, commercial stemwood (ST) and demolition and construction wood (DC) were selected because of the differences in their persistent organic pollutants (POPs), ash and metals content. For household waste, we used a municipal solid waste (MSW) and a refuse-derived fuel (RDF) from MSW with 5-20 wt% and up to 5 wt% food waste content respectively. No clear effect on the formation of pollutants was observed with different food waste content in the fuel blends tested. Combustion of ST-based fuels was very inefficient which led to high PAH emissions (32 ±â€¯3.8 mg/kgfuel). The use of DC clearly increased the total PCDD and PCDF emissions (71 ±â€¯26 µg/kgfuel) and had a clear effect on the formation of toxic congeners (210 ±â€¯87 ng WHO2005-TEQ/kgfuel). The high PCDD and PCDF emissions from DC-based fuels can be attributed to the presence of material contaminants such as small pieces of metals or plastics as well as timber treated with chromated copper arsenate preservatives and pentachlorophenol in the DC source.


Assuntos
Poluentes Atmosféricos/análise , Materiais de Construção/análise , Poluentes Ambientais/análise , Produtos Domésticos/análise , Compostos Orgânicos/química , Resíduos Sólidos/análise , Madeira/química , Poluentes Atmosféricos/química , Poluentes Ambientais/química , Incineração
3.
Waste Manag ; 68: 646-652, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28633911

RESUMO

Torrefaction of municipal solid waste (MSW), refuse-derived fuel (RDF), and demolition and construction wood (DC) was performed at 220°C and a residence time of 90min in a bench-scale reactor. The levels of toxic polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) contained in emission from the torrefaction process were evaluated. In addition, main ash-forming elements and trace metals in the raw feedstock and char were determined. The use of MSW in fuel blends with DC resulted in lower PCDD and PCDF emissions after torrefaction, compared with the RDF blends. The migration of chlorine from the feedstock to the gas phase reduces the chlorine content of the char which may reduce the risk of alkali chloride-corrosion in char combustion. However, trace metals catalytically active in the formation of PCDD and PCDF remain in the char, thereby may promote PCDD and PCDF formation during subsequent char combustion for energy recovery; this formation is less extensive than when the feedstock is used.


Assuntos
Metais/química , Eliminação de Resíduos , Resíduos Sólidos , Madeira , Benzofuranos , Cloro , Incineração
4.
Waste Manag ; 49: 311-319, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26709051

RESUMO

The increased demand for waste wood (WW) as fuel in Swedish co-combustion facilities during the last years has increased the import of this material. Each country has different laws governing the use of chemicals and therefore the composition of the fuel will likely change when combining WW from different origins. To cope with this, enhanced knowledge is needed on WW composition and the performance of pre-treatment techniques for reduction of its contaminants. In this study, the chemical and physical characteristics of 500 WW samples collected at a co-combustion facility in Sweden between 2004 and 2013 were investigated to determine the variation of contaminant content over time. Multivariate data analysis was used for the interpretation of the data. The concentrations of all the studied contaminants varied widely between sampling occasions, demonstrating the highly variable composition of WW fuels. The efficiency of sieving as a pre-treatment measure to reduce the levels of contaminants was not sufficient, revealing that sieving should be used in combination with other pre-treatment methods. The results from this case study provide knowledge on waste wood composition that may benefit its management. This knowledge can be applied for selection of the most suitable pre-treatments to obtain high quality sustainable WW fuels.


Assuntos
Poluentes Ambientais/análise , Poluição Ambiental/prevenção & controle , Gerenciamento de Resíduos/métodos , Madeira/análise , Biocombustíveis/análise , Monitoramento Ambiental , Resíduos Sólidos/análise , Suécia , Gerenciamento de Resíduos/instrumentação
5.
Acta Orthop ; 76(4): 465-9, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16195059

RESUMO

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) are known to have inhibitory effects on new bone formation. We wanted to analyze some effects of the NSAID indomethacin on different inductive stimuli for bone formation. METHODS: We experimentally induced heterotopic new bone with demineralized allogeneic bone matrix (DABM) and with bone autografts in rats, in order to study the effects of indomethacin on new bone formation at 3 and 6 weeks. RESULTS: Indomethacin inhibited net bone formation in DABMs by 30% at 6 weeks. At 6 weeks, the mineral accretion rate was unaffected, indicating that it is at the early phase of the inductive process that mineral accretion is sensitive to inhibition by indomethacin, but not at the later stages. In traumatized skeletal bone, the (45)Ca-specific activity was higher than in non-traumatized bone, while indomethacin significantly reduced the (45)Ca uptake at 3 weeks, but not at 6 weeks. In the autografts, a net mineral loss occurred, but neither mineral content nor (45)Ca incorporation was affected by Indomethacin treatment. INTERPRETATION: Indomethacin inhibited the early phase of new bone formation in heterotopic DABMs and the early bone healing process in traumatized skeletal bone, but did not affect resorption or bone formation in heterotopic autografts. blacksquare, square, filled.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Densidade Óssea/efeitos dos fármacos , Matriz Óssea/efeitos dos fármacos , Transplante Ósseo , Indometacina/farmacologia , Osteogênese/efeitos dos fármacos , Animais , Matriz Óssea/metabolismo , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Cálcio/metabolismo , Ratos , Ratos Sprague-Dawley , Transplante Autólogo , Transplante Homólogo
6.
Acta Orthop ; 76(6): 735-40, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16470423

RESUMO

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) are known to be potent inhibitors of new bone formation. We investigated whether NSAIDs given at surgery influence the long-term results after total hip arthroplasty (THA). PATIENTS AND METHODS: We performed a 10-year follow-up on 142 of 144 patients who had taken part in a randomized trial on the preventive effects of the NSAID ibuprofen on heterotopic ossification after THA. 96 patients were treated with ibuprofen: 48 for 1 week postoperatively, 48 for 2 weeks postoperatively, and 48 patients were not treated. RESULTS: 13 patients had been revised. All revisions except 1 belonged to groups treated with ibuprofen. The 10-year risk for revision was significantly higher in the ibuprofen-treated patients (p = 0.05). Eleven of the revisions occurred due to fractures of the femur (2) or aseptic loosening (9), reasons that may be attributed to negative effects of ibuprofen. For these patients, the 10-year risk for revision was not statistically significantly different between treated and untreated patients (p = 0.08). In addition to the revised patients, 94 other patients were alive at the 10-year follow-up and 84 underwent radiographic examination. 9 loose prostheses were found radiographically, but these were equally distributed between ibuprofen-treated and untreated hips. INTERPRETATION: The high proportion of revisions in the ibuprofen groups, in combination with clinical and experimental evidence of inhibitory effects on new bone formation of NSAIDs, warrants further investigation of the effects of these drugs on prosthetic fixation.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Artroplastia de Quadril/efeitos adversos , Inibidores de Ciclo-Oxigenase/efeitos adversos , Ibuprofeno/efeitos adversos , Ossificação Heterotópica/prevenção & controle , Falha de Prótese , Anti-Inflamatórios não Esteroides/administração & dosagem , Artroplastia de Quadril/métodos , Inibidores de Ciclo-Oxigenase/administração & dosagem , Feminino , Seguimentos , Articulação do Quadril/diagnóstico por imagem , Humanos , Ibuprofeno/administração & dosagem , Masculino , Ossificação Heterotópica/etiologia , Radiografia , Reoperação , Fatores de Risco , Inquéritos e Questionários
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...