103 research outputs found
Efficiency of an ortho-phthalaldehyde based biocide Against Pseudomonas fluorescens adhered to stainless steel surfaces
This work reports the study of the action of ortho-phthalaldehyde, OPA, to control Pseudomonas fluorescens
adhered to stainless steel surfaces. The action of the biocide was assessed, in situ, microscopically using LIVE/DEAD®
BacLight™ Bacterial Viability Kit, developed by Molecular Probes. The results show that When OPA concentration is lower
than 0.1 % the number of dead cells on the surface are strongly dependent on biocide concentration. For lower biocide
concentration, higher dead number of cells can be achieved by increasing the time of exposure to the biocide.Instituto de Biotecnologia e Química Fina, Project POCTI/1999/BIO/35683
Cerium uptake, translocation and toxicity in the salt marsh halophyte Halimione portulacoides (L.), Aellen
Halimione portulacoides plants were exposed to dissolved cerium (Ce) in a hydroponic medium for five days. Ce accumulation in plants followed the metal's increase in the medium although with a very low translocation factor (TF < 0.01) between roots and shoots. Ce median concentrations in roots were 586, 988 and 1103 μg/g (dry wt.), while in shoots the median values reached 1.9, 3.5 and 10.0 μg/g (dry wt.), for plants exposed to 300, 600 and 1200 μg/L of Ce, respectively. No significant differences occurred in the length of roots and shoots among treatment groups, albeit plants exposed to the highest Ce concentration showed a clear loss of turgor pressure on the fifth day. An increase of hydrogen peroxide and malondialdehyde levels were observed in the plant shoots at 1200 μg/L of Ce. The highest concentration also triggered an answer by the shoots' antioxidant enzymes with a decrease in the activity of superoxide dismutase and an increase in peroxidase. However, no significant change in catalase activity was observed, compared to the control group, which may indicate that peroxidase played a more crucial role against the oxidative stress than catalase. Combined results indicate that H. portulacoides was actively responding to a toxic effect imposed by this higher Ce concentration. Nevertheless, changes in normal environmental conditions, may increase the bioavailability of Ce, while in areas where acid mine drainage may occur, the highest Ce concentration tested in this study may be largely exceeded, placing the sustainability of halophytes and estuarine marshes at risk
Adenoid cystic carcinoma of the palpebral lobe of the lacrimal gland – case report and literature review
Epithelial tumors of the lacrimal gland are rare and usually develop in the orbital lobe. We report the exceedingly rare occurrence of a primary adenoid cystic carcinoma in the palpebral lobe of the lacrimal gland. A 26-year-old female was referred for evaluation of a gradually enlarging mass in the lateral upper eyelid, previously diagnosed as a chalazion. Computed tomography revealed a heterogeneous round lesion anterior to the orbital rim. Excisional biopsy was compatible with an adenoid cystic carcinoma. After excluding distant metastasis, and as the patient refused adjuvant radiotherapy, a second surgical procedure, with wide local excision, was indicated. Follow-up showed no recurrence. This case highlights the importance of performing a thorough clinical examination when diagnosing any lateral upper eyelid mass. A high index of suspicion for malignant tumors of the lacrimal gland should always be maintained, and a complete excision with histological analysis should be preferred whenever possible.info:eu-repo/semantics/publishedVersio
Assessing local acid mine drainage impacts on natural regeneration-revegetation of São Domingos mine (Portugal) using a mineralogical, biochemical and textural approach
São Domingos sulfide mine was shut down more than 50 years ago leaving behind eroded and depositional surfaces due to acid mine drainage (AMD). The aim of this study was to assess six selected sites subjected to AMD, considered phytotoxic regions characterized by vegetation scarcity. Two main criteria, nature and composition of soluble fractions and total chemistry of surficial products related to jarosites presence, enabled to set up an overall dichotomy between superficial proximal/discharge and distal/sedimentation areas. Wet and dry sieving results comparison revealed that samples have a predominant sandy texture and lithic (phyllite, quartzite and volcanic country rocks) composition. Quartz, and subordinate feldspar enrichment is also detected in the coarse silt fraction. The results also suggest that the materials under study, when subjected to the local torrential hydrologic regime, have a high mechanical vulnerability, facilitating erosion and mud transport, both critical for vegetation support, and triggering contamination transfer and dispersion. The vicinity and ground-level surfaces of discharging areas are enriched in the jarosite group minerals whereas the sedimentation ones present hypersaline aluminous tendency. The formation of jarosite is considered as an efficient positive environmental contribution to metals and metalloids sequestration/immobilization. The remediation/revegetation solutions to be adopted in each location must have into consideration these differentiating aspects
Susceptibility-Weighted Imaging - Aplicações em Neuropediatria
de imagem em RM, caracterizada pela sua alta resolução espacial e grande sensibilidade
a diferenças de susceptibilidade magnética dos tecidos, acentuando as propriedades
paramagnéticas de produtos como a desoxihemoglobina, hemossiderina, ferro e cálcio e
sendo particularmente útil na avaliação das estruturas venosas.
Objectivos: O objectivo deste trabalho é fazer uma breve revisão das aplicações clínicas
da sequência SWI em neuropediatria e demonstrar a sua grande utilidade,
nomeadamente em comparação as a sequência T2*.
Material e Métodos: Os exames foram realizados a crianças com idades compreendidas
entre o período neonatal e os 16 anos, internadas ou seguidas em consulta no Hospital
Pediátrico D. Estefânia; as imagens SWI foram efectuadas em equipamento Siemens
1.5 T, Avanto, com os seguintes parâmetros: TR 49, TE 40, flip angle 15, espessura
1,6mm.
Resultados: Apresentamos vários casos ilustrativos de patologias em que o SWI
demonstra a sua utilidade e mais-valia, nomeadamente na detecção de lesões
hemorrágicas recentes ou antigas em diferentes contextos particulares em neuropediatria
(patologia hipoxico-isquémica, vascular, trauma não acidental), detecção de cavernomas
e anomalias venosas de desenvolvimento, avaliação de tumores e doenças
neurodegenerativas.
Conclusão: A sequência SWI é bastante útil na avaliação imagiológica de várias
patologias e variantes venosas em neuropediatria, fornecendo uma informação adicional
com implicações diagnósticas e prognósticas comparativamente com o T2*, obviando
também a administração de contraste para avaliação de estruturas venosas
Abiotic modulation of Spartina maritima photobiology in different latitudinal populations
Spartina maritima has a very wide distribution in the northern hemisphere salt marshes crossing a wide
variety of climatic environments. Therefore, it is not strange that some differences arise when observing
the photosynthetic mechanisms of different populations inhabiting different latitudes. During this study
it could be observed that climate is the most important factor controlling the photosynthetic traits of
different populations distributed along a climatic gradient, namely the air temperature, humidity and
light environment. Also some sediment physicochemical parameters such as pH and pore water salinity
showed important influences driving the photosynthetic mechanisms in S. maritima. Furthermore
S. maritima is one of the most abundant halophytes colonizing the Portuguese salt marshes. These facts
have greater importance if one considers the large abundance of this halophytic species and how climate
change will affect their metabolism and thus the ecosystem services provided by this species to the
estuarine system.The authors would like to thank to the “ Fundação para a Ciência
e Tecnologia (FCT)” for funding the research in the Centre of
Oceanography throughout the project PEst-OE/MAR/UI0199/2011
and this specific work throughout the projects ECOSAM (PTDC/
AAC-CLI/104085/2008) and 3M RECITAL (LTER/BIA-BEC/0019/
2009). B. Duarte investigation was supported by FCT throughout a
PhD grant (SFRH/BD/75951/2011)
The Coexistence of Dual Form of Malnutrition among Portuguese Institutionalized Elderly People
In the present study we evaluated the nutritional status of 214 institutionalized elderly residents of both genders, aged 65 years and older of 11 care homes located in the district of Viseu (center of Portugal). The evaluation was based on anthropometric measurements and the Mini Nutritional Assessment (MNA) score. The mean age of the subjects was 82.3 ± 6.1 years-old. Most of the elderly residents were female (72.0%). The majority had 4 years of formal education (51.9%) and was widowed (74.3%) or married (14.0%). Men presented a mean age of 81.2±8.5 years-old, weight 69.3±14.5 kg and BMI 25.33±6.5 kg/m2. In women, the mean age was 84.5±8.2 years-old, weight 61.2±14.7 kg and BMI 27.43±5.6 kg/m2. The evaluation of the nutritional status using the MNA score showed that 24.0% of the residents show a risk of undernutrition and 76.0% of them were well nourished. There was a high prevalence of obese (24.8%) and overweight residents (33.2%) according to the BMI. 7.5% were considered underweight. We also found that according to their waist circumference measurements 88.3% of the residents were at risk for cardiovascular disease (CVD) and 64.0% of them presented very high risk for CVD (WC≥88 cm for women and WC ≥102 cm for men). The present study revealed the coexistence of a dual form of malnutrition (undernourished and overweight) among the institutionalized Portuguese concomitantly with an excess of abdominal adiposity. The high prevalence of residents at high risk for CVD should not be overlooked. Given the vulnerability of the group of institutionalized elderly, our study highlights the importance of the classification of nutritional status based on both instruments: the BMI and the MNA
Fault analysis of a salt minibasin offshore Espírito Santo, SE Brazil: Implications for fluid flow, carbon and energy storage in regions dominated by salt tectonics
High-quality 3D seismic reflection and well data are used to investigate the distribution, evolution history and significance of tectonic faulting in a salt minibasin offshore Espírito Santo, SE Brazil. Displacement-length (Dmax-L) plots, displacement-depth (D-Z) plots and structural maps are compiled to understand the growth history of distinct fault families. Interpreted structures include crestal, corridor, listric and keystone faults. Their geometry, orientation and relative distribution reveal important differences. In detail, listric faults were formed in the investigated salt withdrawal basin, following a NW- to WNW strike, with multiple bright spots and pockmarks around them. The strata into which listric faults sole out have similar seismic, lithological and petrophysical characters to known Cenomanian to Turonian source rocks, which comprise shales and marls with high gamma-ray values. Low-amplitude to transparent seismic facies further indicate the presence of ductile, highly likely organic-rich shales and marls. As a result, three evolutionary stages can be identified: a) Stage 1 is characterised by the formation of NW or WNW-striking listric faults, keystone faults and the onset of reactive diapirism; b) Stages 2 and 3 record active diapirism due to a relative increase in sediment loading, documenting the formation of many crestal, corridor and keystone faults. Importantly, normalised leakage factor analyses reveal keystone faults are the most favourable paths to fluid migrating in the investigated salt minibasin. Conversely, listric faults are likely to form barriers and baffles to fluid in their lower parts
Depositional and geomorphic patterns of mixed calciclastic-siliciclastic systems on a deep-water Equatorial Margin
Distal slope and basin depositional systems in deep waters of the Pará-Maranhão Basin, Equatorial Brazil, are investigated using a high-resolution 3D seismic volume, borehole data and multispectral satellite imagery. A Neogene calciclastic submarine fan and a series of channel-levee systems are analysed at water depths of 100–3,500 m. Channel-levee systems have sinuous and straight morphologies and are of different sizes. Their origin is related to turbidity flows sourced and funnelled from the carbonate shelf to submarine canyons and gullies, as well as from areas with marked slope instability. A mixed calciclastic-siliciclastic sediment input is recognised with autochthonous calcarenites and calcilutites comprising the bulk of sediment on the mid and outer continental shelf. Minor amounts of siliciclastic sediment sourced from small rivers occur on the inner shelf. Sedimentation processes of a distally steepened carbonate ramp are discussed considering a general depositional setting dominated by fluctuations in relative sea-level. Cross-sectional and planar parameters of mixed calciclastic-siliciclastic channel-levee systems are compared to their siliciclastic counterparts. Morphological results show similarities between calciclastic and siliciclastic channel-levee systems. As a corollary, three types of channel-levee systems are described: (a) channels related to calciclastic submarine fans, (b) low-sinuosity, aggradational channels, and (c) high-sinuosity channels
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