Integration of GMR sensors with different technologies

Less than thirty years after the giant magnetoresistance (GMR) effect was described, GMR sensors are the preferred choice in many applications demanding the measurement of low magnetic fields in small volumes. This rapid deployment from theoretical basis to market and state-of-the-art applications can be explained by the combination of excellent inherent properties with the feasibility of fabrication, allowing the real integration with many other standard technologies. In this paper, we present a review focusing on how this capability of integration has allowed the improvement of the inherent capabilities and, therefore, the range of application of GMR sensors. After briefly describing the phenomenological basis, we deal on the benefits of low temperature deposition techniques regarding the integration of GMR sensors with flexible (plastic) substrates and pre-processed CMOS chips. In this way, the limit of detection can be improved by means of bettering the sensitivity or reducing the noise. We also report on novel fields of application of GMR sensors by the recapitulation of a number of cases of success of their integration with different heterogeneous complementary elements. We finally describe three fully functional systems, two of them in the bio-technology world, as the proof of how the integrability has been instrumental in the meteoric development of GMR sensors and their applications.Peer ReviewedPostprint (published version

Virulence assessment of Portuguese isolates of potato cyst nematodes (Globodera spp.)

Identification of species and virulence groups of potato cyst nematodes (PCN), Globodera pallida and G. rostochiensis, present in field populations is important in the control of these nematodes by means of resistant cultivars. In order to characterize the virulence of Globodera spp. isolates from Portugal, 43 G. rostochiensis and three G. pallida isolates were evaluated by measuring their multiplication rates on a susceptible potato cultivar and five differential potato genotypes in a growth chamber pot experiment. Principal Component Analysis and Hierarchical Cluster Analysis showed that the reproduction rates were different in terms of both the numbers of eggs and the numbers of cysts produced. Portuguese isolates of PCN were more virulent on genotypes derived from Solanum vernei than on genotypes derived from other Solanum resistance sources, and there was a significant nematode isolate × host genotype interaction. The virulence bioassay clearly distinguished the two PCN species but failed to differentiate isolates into pathotypes. There was a wide and continuous range of virulence to the resistant genotypes, especially in G. rostochiensis isolates

IAA : Información y actualidad astronómica (22)

Sumario : Estrellas binarias: un matrimonio muy ventajoso.-- Mujeres y ciencia: rompiendo techos.-- La estrella más masiva.-- DECONSTRUCCIÓN Y otros ENSAYOS : Criterios termodinámicos en la evolución de agujeros negros.-- ACTUALIDAD.-- ENTRE BASTIDORES.-- CIENCIA: PILARES E INCERTIDUMBRES. Núcleos de galaxias activas .-- HISTORIAS DE ASTRONOMÍA: “Serendipia” cósmica.-- El increíble y asombroso viaje de Fotón. II Parte.-- ACTIVIDADES IAA.Esta revista se publica con la ayuda de la Acción Complementaria CCT005-06-00178 del Programa Nacional de Fomento de la Cultura Científica y Tecnológica.N

In vitro influence of photodynamic antimicrobial chemotherapy on staphylococcus aureus by using phenothiazines derivatives associated with laser/LED Light

ABSTRACT The aim of this study was to evaluate the effect of photodynamic antimicrobial chemotherapy (PACT) using phenothiazinium dyes -PTZ irradiated with red laser (ʎ660nm) or red-orange LED (ʎ632±2nm) on Staphylococcus aureus in vitro. triplicate tests were performed in 10 groups: control, Laser (L1 + P -and L2 + P -) bacterial suspensions were irradiated only with laser energy 2.4 and 4.8 J/cm 2 respectively, (Led1 + P -and Led2 + P -) irradiated only with LED energy 2.4 and 4.8 J/cm 2 respectively, (L1 + P + and L2 + P + ) irradiated with laser in the presence of 1μg/ml of photosensitizer, (Led1 + P + and Led2 + P + ) irradiated with LED in the presence of 1μg/ml of photosensitizer and finally (L -P + ) only in the presence of PTZ dye. Bactericidal effect of the PACT was assessed by counting colony-forming units. The results showed no significant difference on regards different energy densities on group PACT for both lights. PACT groups (L2 + P + and Led2 + P + ) compared to the Control showed significant reduction of CFUs. LED/Laser groups (L2 + P -and Led2 + P -) compared to control and PTZ groups showed also significant differences as groups LED/Laser (4.8J/cm 2 ) increased the average of CFUs. Although the results of this study have shown a reduction in average number of colonyforming units by the appropriate Laser or LED-dye treatment combination, it this topic requires further investigation

Metabolic risk factors, physical activity and physical fitness in azorean adolescents: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>The prevalence of metabolic syndrome has increased over the last few decades in adolescents and has become an important health challenge worldwide. This study analyzed the relationships between metabolic risk factors (MRF) and physical activity (PA) and physical fitness (PF) in a sample of Azorean adolescents.</p> <p>Methods</p> <p>A cross-sectional school-based study was conducted on 417 adolescents (243 girls) aged 15-18 from the Azorean Islands, Portugal. Height, weight, waist circumference, fasting glucose, HDL-cholesterol, triglycerides, and blood pressure were measured. A sum of MRF was computed, and adolescents were classified into three groups: no MRF, one MRF and two or more MRF. PA was assessed by a sealed pedometer. PF was assessed using five tests from the Fitnessgram Test Battery. Dietary intake was obtained using a semi-quantitative food frequency questionnaire.</p> <p>Results</p> <p>Mean daily steps for girls and boys were 7427 ± 2725 and 7916 ± 3936, respectively. Fifty-nine percent of the adolescents showed at least one MRF and 57.6% were under the healthy zone in the 20 m Shuttle Run Test. Ordinal logistic regression analysis showed that after adjusting for sex, body mass index, socio-economic status and adherence to a Mediterranean diet, adolescents who were in the highest quartile of the pedometer step/counts (≥9423 steps/day) and those who achieved the healthy zone in five tests were less likely to have one or more MRF (OR = 0.56;95%CI:0.33-0.95; OR = 0.55;95%CI:0.31-0.98, respectively).</p> <p>Conclusions</p> <p>Daily step counts and PF levels were negatively associated with having one or more MRF among Azorean adolescents. Our findings emphasize the importance of promoting and increasing regular PA and PF to reduce the public health burden of chronic diseases associated with a sedentary lifestyle.</p

LAL Regulators SCO0877 and SCO7173 as Pleiotropic Modulators of Phosphate Starvation Response and Actinorhodin Biosynthesis in Streptomyces coelicolor

LAL regulators (Large ATP-binding regulators of the LuxR family) constitute a poorly studied family of transcriptional regulators. Several regulators of this class have been identified in antibiotic and other secondary metabolite gene clusters from actinomycetes, thus they have been considered pathway-specific regulators. In this study we have obtained two disruption mutants of LAL genes from S. coelicolor (Δ0877 and Δ7173). Both mutants were deficient in the production of the polyketide antibiotic actinorhodin, and antibiotic production was restored upon gene complementation of the mutants. The use of whole-genome DNA microarrays and quantitative PCRs enabled the analysis of the transcriptome of both mutants in comparison with the wild type. Our results indicate that the LAL regulators under study act globally affecting various cellular processes, and amongst them the phosphate starvation response and the biosynthesis of the blue-pigmented antibiotic actinorhodin. Both regulators act as negative modulators of the expression of the two-component phoRP system and as positive regulators of actinorhodin biosynthesis. To our knowledge this is the first characterization of LAL regulators with wide implications in Streptomyces metabolism

“Healthy Life”: interaction of polyphenols with lipid bilayers and their effects in human cells

This work concerns the transversal project of the CQB thematic line: “Healthy Life: Molecular Interventions and Regulation Mechanisms”. Biologically active plant phytochemicals have a broad range of pharmacological effects including anticarcinogenic, antimicrobial, antioxidant, and anti-inflammatory activity. [1] Notwithstanding the possibility of having a specific target, phytochemicals must interact and permeate through cell membranes in the body. Indeed, it was suggested that those molecules insert into the membranes and thereby may have a promiscuous activity by changing structural properties of lipid bilayers. [2] Some well-known phenolic acids such as caffeic (CA), rosmarinic (RA) and chlorogenic (CGA) acids, whose identification in plant extracts has been achieved by CQB research groups, were selected to be addressed in first place. All the phenolic acids studied have low lipophilicity and among them, RA was the only one with a partition to biological membrane models measurable by fluorescence spectroscopy, as opposed to CA and CGA. Cyclic voltammetry measurements using an electrode modified with a supported lipid bilayer, also indicated a higher affinity of RA to lipid membranes. In addition, oxidation/reduction of the phenolic acids displayed higher reversibility in the lipid milieu than in the aqueous bulk. Indeed, the reduced form of phenolic acids was unstable in aqueous solution. In particular, in DMEM/F-12 cell culture media, a colour change observed after incubation with each compound could be reverted by the addition of a reducing agent. The higher reversibility of phenolic acids oxidation/reduction, once they were inserted in the lipid membrane, may contribute to the stability of the compounds and prevent the formation of degradation products. Molecular dynamics (MD) simulations are being performed to probe the location and orientation of these and other selected compounds in lipid bilayers. The influence of the phenolic acids in the cytoskeleton organization, both actin filaments and microtubules, of a human retinal pigment epithelial cell line (RPE1) was also investigated. All compounds induced concentration and time dependent effects, translated in structural alterations mainly at the cell periphery, and also in the perturbation of cell division. Moreover, it was not evident that these compounds induce apoptosis under the conditions tested. RA seemed to induce evident effects at earlier times and at lower concentrations, as compared to CA and CGA. This higher sensibility of RPE1 cells to RA correlates with the higher affinity of this compound to the lipid bilayer.info:eu-repo/semantics/publishedVersio

VEGFR2 Translocates to the Nucleus to Regulate Its Own Transcription

Vascular Endothelial Growth Factor Receptor-2 (VEGFR2) is the major mediator of the angiogenic effects of VEGF. In addition to its well known role as a membrane receptor that activates multiple signaling pathways, VEGFR2 also has a nuclear localization. However, what VEGFR2 does in the nucleus is still unknown. In the present report we show that, in endothelial cells, nuclear VEGFR2 interacts with several nuclear proteins, including the Sp1, a transcription factor that has been implicated in the regulation of genes needed for angiogenesis. By in vivo chromatin immunoprecipitation (ChIP) assays, we found that VEGFR2 binds to the Sp1-responsive region of the VEGFR2 proximal promoter. These results were confirmed by EMSA assays, using the same region of the VEGFR2 promoter. Importantly, we show that the VEGFR2 DNA binding is directly linked to the transcriptional activation of the VEGFR2 promoter. By reporter assays, we found that the region between -300/-116 relative to the transcription start site is essential to confer VEGFR2-dependent transcriptional activity. It was previously described that nuclear translocation of the VEGFR2 is dependent on its activation by VEGF. In agreement, we observed that the binding of VEGFR2 to DNA requires VEGF activation, being blocked by Bevacizumab and Sunitinib, two anti-angiogenic agents that inhibit VEGFR2 activation. Our findings demonstrate a new mechanism by which VEGFR2 activates its own promoter that could be involved in amplifying the angiogenic response