880 research outputs found
Gas exchange in the salt marsh species Atriplex portulacoides L. and Limoniastrum monopetalum L. in Southern Portugal
Salt marshes are ecosystems subjected to a
variety of environmental stresses like high salinity, water
deficit, intense radiation or high temperatures. Field measurements
were conduced in two halophyte species, Atriplex
portulacoides L. and Limoniastrum monopetalum L., in the
Reserva Natural do Sapal de Castro Marim, to compare their
physiological response, i.e., water potential (w), net photosynthetic
rate (A), stomatal conductance (gs) under natural
conditions. Both species demonstrated marked variations in
w throughout the year, with very low values in the summer,
the period of higher salinity, drought and temperature. Deficit
water potential (Dw = wmidday wpredawn) was lower in
the summer than in other seasons in A. portulacoides but not
in L. monopetalum. The highest values for A and gs in
L. monopetalum were observed in autumn and for A. portulacoides
in winter, presenting both lowest values in spring
and summer. Amax was particularly high for L. monopetalum
than for A. portulacoides in summer and autumn, despite
gsmax was similar in both species. Diurnal pattern ofAand gs
were similar in both species, with higher values in the
morning, decreasing throughout the day
Synthesis, photochemical and in vitro cytotoxic evaluation of benzoselenazole-based aminosquaraines
Squaraine dyes have recently attracted interest as potential second generation photosensitizers for photodynamic
therapy. Several cationic aminosquaraine dyes bearing benzoselenazole terminal nuclei were
synthezised and their cytotoxic activity was tested against four different human tumor cell lines – breast
(MCF-7), non-small cell lung (NCI-H460), cervical (HeLa) and hepatocellular (HepG2) carcinomas – and
against a non-tumor porcine liver primary cell line (PLP2), both in the absence of light and under
irradiation. All dyes, which displayed strong absorption within the phototherapeutic window, were found
to exhibit photodynamic activity and were shown to be, in most cases, more cytotoxic, both in the dark
and upon irradiation, than their benzothiazole analogues.The authors are grateful to the Foundation for Science and
Technology (FCT, Portugal) and the FEDER for CIMO (UID/
AGR/00690/2013) and CQ-VR (UID/QUI/00616/2013) financial
support.info:eu-repo/semantics/publishedVersio
STILF - A spatiotemporal interval logic formalism for reasoning about events in remote sensing data
Although several studies perform time series analysis using remote sensing data provided by Earth observation satellites, few have been explored concerning the reasoning about land use change using these data. Besides, exists the challenge of make the best use of big Earth observation data sets to represent change. In this context, this work presents a new formalism - STILF (Spatiotemporal Interval Logic Formalism), and shows how to use it for reasoning about land use change using big Earth observation data. Extending the ideas from Allen’s interval temporal logic, we introduce predicates holds(o, p, t) and occur(o, p, Te) to build a general framework to reason about events. Events can be defined as complete entities on their respective time intervals and their lifetime is limited while objects persist in time, with a defined begin and end. Since events are intrinsically related to the objects they modify, a geospatial event formalism should specify not only what happens, but also which objects are affected by such changes. The formalism proposed and predicates extended from Allen''''''''s ideas can model and capture changes using big Earth observation data, and also allows reasoning about land use trajectories in regional or global areas. Examples for tropical forest area application is presented to better understand our proposal using STILF. For the future, the proposed formalism will be include other temporal analysis tools to thinking about events related the land use and cover change
Superficial Femoral Artery Recanalization with Self-expanding Nitinol Stents: Long-term Follow-up Results
PurposeSince long-term patency and device integrity of nitinol stents in SFA lesions are not well studied, we examined clinical outcome, patency and device integrity after stenting long lesions using a standardized implantation technique.MethodsBetween 2001 and 2006, 59 patients (74 lesions) were treated with the same nitinol self-expandable stent (Zilver, Cook, USA) and technique for SFA recanalization. Clinical charts and imaging were retrospectively reviewed for patency (primary and assisted-primary), and device integrity.ResultsPatients were 74.5 (10.9) years old (range 49 to 93), 64% male, 42% diabetic, 62% hypertensive and 67% current or former smokers. Lesions were 23% TASC B, 16% TASC C, or 61% TASC D. Mean recanalization length was 19cm (range 3 to 53). Mean number of stents per patient was 2.8 (total 210). Mean follow-up time was 2.4 years (range 3 days to 4.8 years). Kaplan-Meier estimates for primary patency rates were 90%, 78%, 74%, 69%, and 69% at 1, 2, 3, 4 and 4.8 years, respectively. Ten restenoses at a mean of 500 (388) days (1–1251 days) were successfully recanalized. The assisted primary patency rates were 96%, 90%, 90%, 90% and 90% at 1, 2, 3, 4 and 5 years, respectively. Six complete occlusions could not be reverted by a second recanalization procedure, and were treated by surgical bypass (1 case), amputation (3 cases), or medical management (2 cases). One (1.04%) Class II stent fracture was noted.ConclusionsSFA recanalization with a standardized implantation technique and nitinol stents provides good long-term primary and assisted-primary patency
Synthesis, photochemical and in vitro cytotoxic evaluation of new iodinated aminosquaraines as potential sensitizers for photodynamic therapy
In this work, several benzothiazole-based aminosquaraine dyes, displaying strong
absorption within the so-called phototherapeutic window (650–800 nm), were synthesized. The ability,
of all the new dyes, to generate singlet oxygen was assessed by determining the correspondent
phosphorescence emission and through the comparison with a standard. The quantum yields of
singlet oxygen generation were determined and exhibited to be strongly dependent on the nature of
the amino substituents introduced in the squaric ring. The photodynamic activity of the synthesized
dyes was tested against four human tumor cell lines: breast (MCF-7), lung (NCI-H460), cervical (HeLa)
and hepatocellular (HepG2) carcinomas; and a non-tumor porcine liver primary cell culture (PLP2).
All the compounds synthesized were found to be able to inhibit tumor cells growth upon irradiation
more than in the dark, in most of the cases, very significantly. Considering the photodynamic activity
exhibited and the low toxicity displayed for the non-tumor cells, some of the synthetized dyes can be
regarded as potential candidates as photosensitizers for PDT.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER
for CIMO (UID/AGR/00690/2013) and CQ-VR (UID/QUI/00616/2013) financial support, as also for R.
Calhelha contract.info:eu-repo/semantics/publishedVersio
Robust optimization strategies for sheet metal springback compensation
.Sheet metal forming is a major industrial process, mainly due to its cost efficiency after the establishment of the processdesign. However, the process design from tools geometry to load conditions is not straightforward, as a consequence of the side effects associated with sheet metal forming. The emphas is in this area goes to the springback effect or elastic recovery,which is one of the main causes of part’s inaccuracy,demanding tool compensation.This work proposes to compare different robust opti-mization strategies to sheet metal forming springback compensation.The methodology adopted resorts to Response SurfaceMethod(RSM),as well as to Finite Element Model Updating (FEMU) strategies, to adjust the design variables.These include the tools’surfaces,which are parametrised with NURBS.These strategies are then compared using theU-Rail benchmark. The results achieved reveal a reduction of 99% on the geometrical error of the final piece for the best methodology
Effect of alendronate on endochondral ossification in mandibular condyles of growing rats
The replacement of the calcified cartilage by bone tissue during the endochondral ossification of the mandibular condyle is dependent of the resorbing activity of osteoclats. After partial resorption, calcified cartilage septa are covered by a primary bone matrix secreted by osteoblasts. Osteoadherin (OSAD) is a small proteoglycan present in bone matrix but absent in cartilage during the endochondral ossification. The aim of this study was to analyze the effect of alendronate, a drug known to inhibit bone resorption by osteoclasts, on the endochondral ossification of the mandibular condyle of young rats, by evaluating the distribution of osteoclasts and the presence of OSAD in the bone matrix deposited. Wistar newborn rats (n=45) received daily injections of alendronate (n=27) or sterile saline solution as control (n=18) from the day of birth until the ages of 4, 14 and 30 days. At the days mentioned, the mandibular condyles were collected and processed for transmission electron microscopy analysis. Specimens were also submitted to tartrate resistant acid phosphatase (TRAP) histochemistry and ultrastructural immunodetection of OSAD. Alendronate treatment did not impede the recruitment and fusion of osteoclasts at the ossification zone during condyle growth, but they presented inactivated phenotype. The trabeculae at the ossification area consisted of cartilage matrix covered by a layer of primary bone matrix that was immunopositive to OSAD at all time points studied. Apparently, alendronate impeded the removal of calcified cartilage and maturation of bone trabeculae in the mandibular ramus, while in controls they occurred normally. These findings highlight for giving attention to the potential side-effects of bisphosphonates administered to young patients once it may represent a risk of disturbing maxillofacial development
Implicações técnicas e ecossistêmicas do manejo inadequado da arborização urbana: o caso das podas drásticas em oitis na cidade de Ilha Solteira - SP
Oiti is a large species, recommended for urban afforestation. However, it is often implemented in inappropriate places, which can cause conflicts with some factors in cities and with the population in general. Thus, inadequate pruning is carried out, causing great damage to the plant and to public management. The objective of this work was to analyze the drastic pruning performed on Oiti trees used in urban afforestation in the municipality of Ilha Solteira - SP. Oiti specimens diagnosed with drastic pruning were diagnosed and data related to location, presence of electriclal cables and pruning order were collected from the City Hall. The reasons for pruning were listed, the trees were registered using digital photos, which were compared to images from Google Street View® prior to the pruning. It was concluded that Oiti trees received drastic pruning in several neighborhoods in the city of Ilha Solteira, which were carried out with no justification nor request/consent from the City Hall, resulting in some cases in the death of the tree and consequent loss of urban green.O Oiti é uma espécie de grande porte, recomendada para arborização urbana. Contudo, muitas vezes é implantada em locais inadequados, o que pode ocasionar conflitos com alguns fatores nas cidades e com a população em geral. Assim, podas inadequadas são realizadas, ocasionando grandes prejuízos na planta e para a gestão pública. O objetivo deste trabalho foi analisar as podas drásticas realizadas em árvores de Oiti utilizadas na arborização urbana no município de Ilha Solteira - SP. Foram diagnosticados exemplares de Oiti consideradas com poda drástica e coletados dados referentes à localização, presença de fiação e pedido de poda junto a Prefeitura Municipal. Foram elencados os motivos para a realização da poda, o registro das árvores por fotos digitais, que foram comparadas com imagens do Google Street View® anteriores à realização da poda. Concluiu-se que árvores de Oiti receberam poda drástica em diversos bairros da cidade de Ilha Solteira, sendo estas realizadas sem justificativa e solicitação/anuência da Prefeitura Municipal, resultando em alguns casos na morte da árvore e consequente perda do verde urbano
Quintessence and Gravitational Waves
We investigate some aspects of quintessence models with a non-minimally
coupled scalar field and in particular we show that it can behave as a
component of matter with . We study the
properties of gravitational waves in this class of models and discuss their
energy spectrum and the cosmic microwave background anisotropies they induce.
We also show that gravitational waves are damped by the anisotropic stress of
the radiation and that their energy spectrum may help to distinguish between
inverse power law potential and supergravity motivated potential. We finish by
a discussion on the constraints arising from their density parameter
\Omega_\GW.Comment: 21 pages, 18 figures, fianl version, accepted for publication in PR
- …