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1.
Environ Pollut ; 265(Pt A): 114695, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32806416

RESUMO

Mining causes extensive damage to aquatic ecosystems via acidification, heavy metal pollution, sediment loading, and Ca decline. Yet little is known about the effects of mining on freshwater systems in the Southern Hemisphere. A case in point is the region of western Tasmania, Australia, an area extensively mined in the 19th century, resulting in severe environmental contamination. In order to assess the impacts of mining on aquatic ecosystems in this region, we present a multiproxy investigation of the lacustrine sediments from Owen Tarn, Tasmania. This study includes a combination of radiometric dating (14C and 210Pb), sediment geochemistry (XRF and ICP-MS), pollen, charcoal and diatoms. Generalised additive mixed models were used to test if changes in the aquatic ecosystem can be explained by other covariates. Results from this record found four key impact phases: (1) Pre-mining, (2) Early mining, (3) Intense mining, and (4) Post-mining. Before mining, low heavy metal concentrations, slow sedimentation, low fire activity, and high biomass indicate pre-impact conditions. The aquatic environment at this time was oligotrophic and dystrophic with sufficient light availability, typical of western Tasmanian lakes during the Holocene. Prosperous mining resulted in increased burning, a decrease in landscape biomass and an increase in sedimentation resulting in decreased light availability of the aquatic environment. Extensive mining at Mount Lyell in the 1930s resulted in peak heavy metal pollutants (Pb, Cu and Co) and a further increase in inorganic inputs resulted in a disturbed low light lake environment (dominated by Hantzschia amphioxys and Pinnularia divergentissima). Following the closure of the Mount Lyell Co. in 1994 CE, Ca declined to below pre-mining levels resulting in a new diatom assemblage and deformed diatom valves. Therefore, the Owen Tarn record demonstrates severe sediment pollution and continued impacts of mining long after mining has stopped at Mt. Lyell Mining Co.


Assuntos
Ecossistema , Poluentes Químicos da Água/análise , Austrália , Cálcio , Monitoramento Ambiental , Sedimentos Geológicos , Tasmânia
2.
Food Res Int ; 105: 210-220, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29433209

RESUMO

Addition of ß-acids extracted from hop at different levels (0, 30mgkg-1, 60mgkg-1, 240mgkg-1) to the diet of broiler chickens demonstrated significant effects on the average concentration of polar metabolites and fatty acids of relevance for meat quality. The largest metabolic differences between control group and chicken fed different levels of ß-acids were achieved using 30mgkg-1 of supplement. As determined by EPR spin-trapping, increased redox stability was also obtained for meat from chicken fed 30mgkg-1 of ß-acids which also had highest level of endogenous antioxidants, especially anserine, carnosine, NADH and PUFAs. Diet and storage period were found to affect protein oxidation and myosin and actin were recognized as the main targets of protein oxidation. Myofibrillar proteins from chicken fed hop ß-acids showed to be less susceptible to oxidation. A moderated level of hop ß-acids as dietary supplement accordingly improve the overall redox stability, protecting myofibrillar proteins and fatty acids against oxidation and improve the nutritional properties of meat from broiler chickens.


Assuntos
Ração Animal , Galinhas , Humulus/química , Carne/análise , Terpenos/química , Animais , Cicloexanonas/química , Cicloexanonas/metabolismo , Metaboloma , Proteínas Musculares/análise , Proteínas Musculares/química , Oxirredução , Terpenos/metabolismo
3.
J Environ Radioact ; 151 Pt 3: 579-86, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26344369

RESUMO

Soil and sediment samples from the Sydney basin were measured to ascertain fallout radionuclide activity concentrations and atom ratios. Caesium-137 ((137)Cs) was measured using gamma spectroscopy, and plutonium isotopes ((239)Pu and (240)Pu) were quantified using accelerator mass spectrometry (AMS). Fallout radionuclide activity concentrations were variable ranging from 0.6 to 26.1 Bq/kg for (137)Cs and 0.02-0.52 Bq/kg for (239+240)Pu. Radionuclides in creek sediment samples were an order of magnitude lower than in soils. (137)Cs and (239+240)Pu activity concentration in soils were well correlated (r(2) = 0.80) although some deviation was observed in samples collected at higher elevations. Soil ratios of (137)Cs/(239+240)Pu (decay corrected to 1/1/2014) ranged from 11.5 to 52.1 (average = 37.0 ± 12.4) and showed more variability than previous studies. (240)Pu/(239)Pu atom ratios ranged from 0.117 to 0.165 with an average of 0.146 (±0.013) and an error weighted mean of 0.138 (±0.001). These ratios are lower than a previously reported ratio for Sydney, and lower than the global average. However, these ratios are similar to those reported for other sites within Australia that are located away from former weapons testing sites and indicate that atom ratio measurements from other parts of the world are unlikely to be applicable to the Australian context.


Assuntos
Radioisótopos de Césio/análise , Plutônio/análise , Cinza Radioativa/análise , Poluentes Radioativos do Solo/análise , Poluentes Radioativos da Água/análise , Sedimentos Geológicos/análise , Espectrometria de Massas , New South Wales
4.
Science ; 346(6211): 844-7, 2014 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-25395535

RESUMO

Increased catchment erosion and nutrient loading are commonly recognized impacts of deforestation on global wetlands. In contrast, an increase in water availability in deforested catchments is well known in modern studies but is rarely considered when evaluating past human impacts. We used a Budyko water balance approach, a meta-analysis of global wetland response to deforestation, and paleoecological studies from Australasia to explore this issue. After complete deforestation, we demonstrated that water available to wetlands increases by up to 15% of annual precipitation. This can convert ephemeral swamps to permanent lakes or even create new wetlands. This effect is globally significant, with 9 to 12% of wetlands affected, including 20 to 40% of Ramsar wetlands, but is widely unrecognized because human impact studies rarely test for it.


Assuntos
Conservação dos Recursos Naturais , Abastecimento de Água , Áreas Alagadas , Austrália , Clima , Humanos , Lagos , Nova Zelândia
5.
J Environ Manage ; 112: 330-9, 2012 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-22964040

RESUMO

The accumulation of monosulfidic sediments in inland waterways is emerging as a major environmental issue. Mobilisation and suspension of monosulfidic sediments can result in deoxygenation, acidification of the water column and mobilisation of trace metals. The controls on monosulfidic sediment mobilisation and the critical thresholds for its scour and entrainment have not been established. This study examines the effect of a minor flood event (average return interval of 5 years) on sulfidic sediment scour in the Wakool River in southern NSW, Australia. Five profiles were sampled within a small (~300 m) reach before and after a minor flood event to determine the degree of sediment scour and transport. The results indicate substantial scour of both monosulfidic sediments and underlying bed sediments (approximately 2100 m(3)). Changes in the sediment geochemistry suggest large concentrations of monosulfidic sediments had been suspended in the water column, partially-oxidised and redeposited. This is supported by (210)Pb results from one of the profiles. These results suggest that these monosulfidic sediments can move as bed load during minor flood events.


Assuntos
Sedimentos Geológicos/análise , Monitoramento Ambiental , Rios
6.
Colorectal Dis ; 14(9): e608-11, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22507755

RESUMO

AIM: Using a high-resolution 3D endoanal ultrasound, we have observed that some perianal fistulas show a hypoechogenic fistula tract surrounded by a well-defined hyperechogenic area with a thin hypoechogenic edge in patients with Crohn's disease ['Crohn's Ultrasound Fistula Sign' (CUFS)], unlike conventional fistula tracks. The study aimed to determine the prevalence of CUFS in a consecutive series of patients with anal fistula. METHOD: Of 157 patients (median age 45, range 14-86 years, 100 males) with perianal fistula were examined with 3D endoanal ultrasound. All 3D volumes were stored and analysed retrospectively by two independent observers blinded to the clinical information of the patients. RESULTS: There were 29 patients with Crohn's disease of whom 20 (69%) showed CUFS. CUFS was absent in 125 (98%) of 128 patients without Crohn's disease. The positive and negative predictive value of CUFS for Crohn's disease was 87% and 93%, respectively. The kappa value of the two independent observers was 0.77, indicating a substantial interobserver agreement. CONCLUSION: This study provides a new 3D endoanal ultrasound criterion, CUFS, of perianal fistula in patients with Crohn's disease. The sign can be used to discriminate a Crohn's from other types of fistula, which may be useful in the management of patients with anal fistula.


Assuntos
Doença de Crohn/diagnóstico por imagem , Imageamento Tridimensional , Fístula Retal/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Doença de Crohn/complicações , Endossonografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fístula Retal/etiologia , Estudos Retrospectivos , Sensibilidade e Especificidade
7.
Water Sci Technol ; 53(10): 21-7, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16838685

RESUMO

Climate change has been identified as a major influence on basin water balances. However, land use and water use practices have also been identified as players. This case study was completed to better understand a changing water balance affecting a major basin in Alberta. The Beaver River basin is located in east central Alberta. Much of the basin has been developed for agricultural use; however, a number of heavy oil operations also exist. Both sectors use surface and groundwater. Evidence exists that the basin hydrology has changed since the mid-1970s. Coincidently, it was at this time that much of the land was cleared for agricultural development and commercial-scale oil development began. Oil industry use of water was suspected as the main cause for the changes observed. To investigate this further, data from regional hydrometric and meteorological stations were assessed along with water well hydrographs and historical satellite images. A significant correlation was found between basin responses and a climate phenomenon known as the Pacific decadal oscillation. Although the correlation between the Pacific decadal oscillation and basin hydrology appeared strong, deforestation for agricultural development also seemed to have an effect. Use of the local water resources was found to be of minor significance.


Assuntos
Conservação dos Recursos Naturais , Abastecimento de Água , Agricultura , Alberta , Monitoramento Ambiental , Água Doce , Efeito Estufa , Gelo , Temperatura , Movimentos da Água
8.
Ann Transplant ; 7(3): 52-4, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12465434

RESUMO

Recombinant activated factor VII (rFVIIa, NovoSeven, Novo Nordisk A/S, Denmark) is a treatment used to prevent and arrest intra- and postoperative bleeding in patients with haemophilia A or B complicated by circulating anticoagulants (inhibitors of FVIII and FIX) and in patients without haemophilia who spontaneously develop inhibitors of FVIII, i.e. in acquired haemophilia. Patients who qualify for liver transplantation due to liver dysfunction may have varying degrees of coagulation impairment and thus carry an elevated risk of massive bleeding and have worse prognosis. The authors administered recombinant activated factor VII to two patients with coagulation abnormalities in the course of Wilson's disease during liver transplantation.


Assuntos
Perda Sanguínea Cirúrgica/prevenção & controle , Fator VII/uso terapêutico , Hemostasia Cirúrgica/métodos , Degeneração Hepatolenticular/cirurgia , Transplante de Fígado/métodos , Adolescente , Adulto , Feminino , Humanos , Período Intraoperatório , Proteínas Recombinantes/uso terapêutico
9.
Appl Radiat Isot ; 53(3): 415-9, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10972146

RESUMO

Previous analytical methods employed to measure 99Tc:99mTc ratios in chromatographic 99mTc generators, derived from fission-based 99Mo, were limited in monitoring the ratios in low activity generators, over the extent of their elution regimes. For regulatory purposes, ICP-MS was employed to measure total technetium in generator eluates down to a level of 200 pg ml(-1) (200 ppt). Measured 99Tc:99mTc ratios compared very well with the theoretically computed values, ranging from 47:1 for a first elution of a generator with a long ingrowth time to 1.4:1 for the 17th elution of a generator with a short ingrowth time.


Assuntos
Pertecnetato Tc 99m de Sódio/química , Tecnécio/análise , Calibragem , Cromatografia por Troca Iônica/métodos , Raios gama , Espectrometria de Massas/métodos
12.
Pol Tyg Lek ; 45(1-3): 21-5, 1990.
Artigo em Polonês | MEDLINE | ID: mdl-2399185

RESUMO

The authors discuss own experience with the treatment of carotid artery stenosis. Diagnostic principles and indications to surgical treatment, technique of block anesthesia, an operation and obtained results are also discussed. Internal carotid artery stenosis was treated surgically in 90 patients within 1985-1988. Block anesthesia enabling intraoperational control of patients' consciousness was used in 72 cases. Satisfactory early results were noted in 92.9% of patients. Two patients died after surgery whereas 5 patients suffered from neurological complications. Favourable late results (follow-up period ranged from 6 to 48 months) were noted in 64 out of 70 patients which reported to clinical examination (91.4%).


Assuntos
Doenças das Artérias Carótidas/cirurgia , Idoso , Doenças das Artérias Carótidas/diagnóstico , Constrição Patológica/diagnóstico , Constrição Patológica/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Bloqueio Nervoso
15.
Anaesth Resusc Intensive Ther ; 4(3): 181-5, 1976.
Artigo em Inglês | MEDLINE | ID: mdl-1015616

RESUMO

The authors analyse 151 cases of anaesthesia for total hip joint alloplasty. Fifty-three patients had general anaesthesia and in 98 cases epidural analgesia was performed. Although the statistical analysis of correlations between the fall of the arterial blood pressure and the age of patients failed to demonstrate significant differences between both types of anaesthesia the authors regard local analgesia as superior.


Assuntos
Anestesia , Cimentos Ósseos , Articulação do Quadril/cirurgia , Prótese Articular , Adulto , Idoso , Anestesia Epidural , Anestesia Geral , Pressão Sanguínea , Bupivacaína , Halotano , Humanos , Lidocaína , Pessoa de Meia-Idade , Óxido Nitroso
16.
Anaesth Resusc Intensive Ther ; 3(4): 305-13, 1975.
Artigo em Inglês | MEDLINE | ID: mdl-1229912

RESUMO

During a period of 5 months 44 patients with acute carbon monoxide poisoning were treated with hyperbaric oxygen. In 80% of cases very good results were obtained. Analizing the causes of death the following factors were considered: the duration of exposure to carbon monoxide, the age of patients and the degree of unconsciousness at the time of hospital admission. The patients stayed in a hyperbaric chamber for 90 min. on the average. The mean pressure of 100% oxygen was 2.5 ATA. When lower pressures were applied the time necessary for elimination of the same amount of carbon monoxide from the organism was slightly prolonged, nevertheless, the use of lower pressures is recommended, since it reduced the risk of toxic effects on oxygen.


Assuntos
Intoxicação por Monóxido de Carbono/terapia , Oxigenoterapia Hiperbárica , Idoso , Asfixia/mortalidade , Pressão Atmosférica , Intoxicação por Monóxido de Carbono/mortalidade , Intoxicação por Monóxido de Carbono/fisiopatologia , Carboxihemoglobina/análise , Sistema Cardiovascular/fisiopatologia , Feminino , Humanos , Hipóxia/mortalidade , Masculino , Oxigênio/efeitos adversos , Insuficiência Respiratória/diagnóstico , Fatores de Tempo , Inconsciência
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