163 research outputs found
Benchtop SS-OCT â layout and performance evaluation
 Abstract1â Optical coherence tomography (OCT) is a non-invasive biomedical imaging technique that provides high speed and high resolution three dimensional and cross sectional images of biological samples, in vivo and in situ. OCT applications targeting small animals is believed to bring developments in medical techniques, instruments, diagnosis and therapies for a number of human diseases as always have been the case of animal experimentation. With the swept source OCT (SS-OCT) system presented in this work, we were able to achieve performance parameters that meet the requirements to image the retina of small animals. Performance characteristics include 105 dB for system sensitivity, a roll-off below 1 dB/mm over 3 mm depth and an axial resolution of 8 ÎŒm. We describe the layout and acquisition/processing solutions towards fast imaging of in vivo samples
Hepatoprotection of mentha aquatica L., lavandula dentata L. and leonurus cardiaca L.
The phenolic composition of hydroethanolic extracts of Mentha aquatica L., Lavandula dentata L. and Leonurus cardiaca L., obtained from plants grown under organic cultivation, was determined and their hepatoprotective effects were investigated in vitro . L. cardiaca extract was rich in phenylethenoid glycosides, especially lavandolifolioside (254 ± 36 Όg/mg), whereas rosmarinic acid and eriodictyol-O-rutinoside were the major phenolic compounds of L. dentata and M. aquatica extracts, accounting for 68 ± 7 Όg/mg and 145 ± 22 Όg/mg, respectively. These differential phenolic components presumably account for their dissimilar antioxidant properties. While L. cardiaca extract showed moderate biological effects, M. aquatica extract displayed high antioxidant activity in chemical models, and that of L. dentata was effective in counteracting potassium dichromate-induced ROS generation in human hepatocarcinoma cells. Moreover, M. aquatica extract (50 Όg/mL) and its mixture (50%/50%) with L. dentata extract displayed an effective cytoprotective effect.Aveiro and FCT/MCT financed the QOPNA research Unit (FCT UID/QUI/00062/2019) through
national funds and, where applicable, co-financed by the FEDER, within the PT2020 Partnership
Agreement, to the Portuguese NMR Network and to the Portuguese Mass Spectrometry Network (RNEM,
LISBOA-01-0145-FEDER-402-022125). This study was supported in part by the CIBERehd (EHD15PI05/2016) and Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III, Spain (PI16/00598, co-funded by European Regional Development Fund/European Social Fund, âInvesting in your futureâ); Spanish Ministry of Economy, Industry and Competitiveness (SAF2016-75197-R); Junta de Castilla y Leon (SA063P17); AECCScientific Foundation (2017/2020), Spain; and âCentro Internacional sobre el Envejecimientoâ (OLD-HEPAMARKER, 0348_CIE_6_E), Spain. Project AgroForWealth (CENTRO-01-0145-FEDER-000001) funded by Centro2020, through FEDER and PT2020, financed the research contract of Susana M. Cardoso.info:eu-repo/semantics/publishedVersio
Mass spectrometry parameters optimization for the 46 multiclass pesticides determination in strawberries with gas chromatography ion-trap tandem mass spectrometry
Multiclass analysis method was optimized in order to analyze pesticides traces by gas
chromatography with ion-trap and tandem mass spectrometry (GC-MS/MS). The influence of some
analytical parameters on pesticide signal response was explored. Five ion trap mass spectrometry
(IT-MS) operating parameters, including isolation time (IT), excitation voltage (EV), excitation time
(ET),maximum excitation energy or âqâ value (q), and isolationmass window (IMW) were numerically
tested in order to maximize the instrument analytical signal response. For this, multiple linear
regression was used in data analysis to evaluate the influence of the five parameters on the analytical
response in the ion trap mass spectrometer and to predict its response. The assessment of the five
parameters based on the regression equations substantially increased the sensitivity of IT-MS/MS in
the MS/MS mode. The results obtained show that for most of the pesticides, these parameters have a
strong influence on both signal response and detection limit.Using the optimized method, a multiclass
pesticide analysis was performed for 46 pesticides in a strawberry matrix. Levels higher than the limit
established for strawberries by the European Union were found in some samples
Benchtop SS-OCT â layout and performance evaluation
Abstract1â Optical coherence tomography (OCT) is a non-invasive biomedical imaging technique that provides high speed and high resolution three dimensional and cross sectional images of biological samples, in vivo and in situ. OCT applications targeting small animals is believed to bring developments in medical techniques, instruments, diagnosis and therapies for a number of human diseases as always have been the case of animal experimentation.
With the swept source OCT (SS-OCT) system presented in this work, we were able to achieve performance parameters that meet the requirements to image the retina of small animals. Performance characteristics include 105 dB for system sensitivity, a roll-off below 1 dB/mm over 3 mm depth and an axial resolution of 8 ÎŒm. We describe the layout and acquisition/processing solutions towards fast imaging of in vivo samples
Ferroelectric orthorhombic ZrO2 thin films achieved through nanosecond laser annealing
A new approach for the stabilization of the ferroelectric orthorhombic ZrO2 films is demonstrated through nanosecond laser annealing (NLA) of as-deposited Si/SiOx/W(14 nm)/ZrO2(8 nm)/W(22 nm), grown by ion beam sputtering at low temperatures. The NLA process optimization is guided by COMSOL multiphysics simulations. The films annealed under the optimized conditions reveal the presence of the orthorhombic phase, as confirmed by X-ray diffraction, electron backscatter diffraction, and transmission electron microscopy. Macroscopic polarization-electric field hysteresis loops show ferroelectric behavior, with saturation polarization of 12.8 mu C cm(-2), remnant polarization of 12.7 mu C cm(-2) and coercive field of 1.2 MV cm(-1). The films exhibit a wake-up effect that is attributed to the migration of point defects, such as oxygen vacancies, and/or a transition from nonferroelectric (monoclinic and tetragonal phase) to the ferroelectric orthorhombic phase. The capacitors demonstrate a stable polarization with an endurance of 6.0 x 10(5) cycles, demonstrating the potential of the NLA process for the fabrication of ferroelectric memory devices with high polarization, low coercive field, and high cycling stability.A.P.S.C. and M.C.I. contributed equally to this work. This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding Contract UIDB/04650/2020. This work has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 958174 (M-ERA-NET3/0003/2021-NanOx4EStor). M. C. I. and C. G. acknowledge the financial support by a grant of the Ministry of Research, Innovation and Digitization, CNCS/CCCDI - UEFISCDI, project number COFUND-M-ERANET-3-NanOx4Estor, within PNCDI III and POC 332/390008/29.12.2020-SMIS 109522. The authors acknowledge the CERIC-ERIC Consortium for access to experimental facilities and financial support under proposals 20202037, 20202038, and 20192055. The authors would also like to thank Jose Santos for technical support in the Thin Film Laboratory at CF-UM-UP. J.L.M-D. thanks the ERC grant, EU-H2020-ERC-ADG #882929, EROS. And the Royal Academy of Engineering, grant CIET1819_24. MOH thanks the Herchel Smith foundation of Cambridge for a research fellowship. This work made use of the University of Cambridge Wolfson Electron Microscopy Suite
Herpesviruses Serology Distinguishes Different Subgroups of Patients From the United Kingdom Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Biobank.
The evidence of an association between Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and chronic herpesviruses infections remains inconclusive. Two reasons for the lack of consistent evidence are the large heterogeneity of the patients' population with different disease triggers and the use of arbitrary cutoffs for defining seropositivity. In this work we re-analyzed previously published serological data related to 7 herpesvirus antigens. Patients with ME/CFS were subdivided into four subgroups related to the disease triggers: S0-42 patients who did not know their disease trigger; S1-43 patients who reported a non-infection trigger; S2-93 patients who reported an infection trigger, but that infection was not confirmed by a lab test; and S3-48 patients who reported an infection trigger and that infection was confirmed by a lab test. In accordance with a sensitivity analysis, the data were compared to those from 99 healthy controls allowing the seropositivity cutoffs to vary within a wide range of possible values. We found a negative association between S1 and seropositivity to Epstein-Barr virus (VCA and EBNA1 antigens) and Varicella-Zoster virus using specific seropositivity cutoff. However, this association was not significant when controlling for multiple testing. We also found that S3 had a lower seroprevalence to the human cytomegalovirus when compared to healthy controls for all cutoffs used for seropositivity and after adjusting for multiple testing using the Benjamini-Hochberg procedure. However, this association did not reach statistical significance when using Benjamini-Yekutieli procedure. In summary, herpesviruses serology could distinguish subgroups of ME/CFS patients according to their disease trigger, but this finding could be eventually affected by the problem of multiple testing
Nitric Oxide Mediates the Hormonal Control of Crassulacean Acid Metabolism Expression in Young Pineapple Plants
Inequality in the distribution of ear, nose and throat specialists in 15 Latin American countries: an ecological study.
OBJECTIVE: To explore sociogeographical inequalities in the availability and distribution of ear, nose and throat specialists (ENTs) in 15 Latin American (LA) countries. DESIGN: Ecological. SETTING: Spanish and Portuguese-speaking countries of LA.The number of registered ENTs in 2017 was obtained from the National ENT Society in each country. OUTCOME MEASURES: The ENT rate/million population was calculated at the national and subnational (eg, state) level. Three measures were calculated to assess subnational distributive inequality of ENTs: (1) absolute and (2) relative index of dissimilarity; and (3) concentration index (using the Human Development Index as the equity stratifier). Finally, the ratio of ENTs/million population in the capital area compared with the rest of the country was calculated. RESULTS: There was more than a 30-fold difference in the number of ENTs/million population across the included countries-from 61.0 in Argentina (95% CI 58.7 to 63.4) to 2.8 in Guatemala (95%âCI 2.1 to 3.8). In all countries, ENTs were more prevalent in advantaged areas and in capital areas. To attain distributive equality, Paraguay would need to redistribute the greatest proportion of its ENT workforce (67.3%; 95%âCI 57.8% to 75.6%) and Brazil the least (18.5%; 95%âCI 17.6% to 19.5%). CONCLUSIONS: There is high inequality in the number and distribution of ENTs between and within the 15 studied countries in LA. This evidence can be used to inform policies that improve access to ear and hearing services in the region, such as scale-up of training of ENTs and incentives to distribute specialists equally. These actions to reduce inequities, alongside addressing the social determinants of ear and hearing health, are essential to realise Universal Health Coverage
Direct evidence for phosphorus limitation on Amazon forest productivity
The productivity of rainforests growing on highly weathered tropical soils is expected to be limited by phosphorus availability1. Yet, controlled fertilization experiments have been unable to demonstrate a dominant role for phosphorus in controlling tropical forest net primary productivity. Recent syntheses have demonstrated that responses to nitrogen addition are as large as to phosphorus2, and adaptations to low phosphorus availability appear to enable net primary productivity to be maintained across major soil phosphorus gradients3. Thus, the extent to which phosphorus availability limits tropical forest productivity is highly uncertain. The majority of the Amazonia, however, is characterized by soils that are more depleted in phosphorus than those in which most tropical fertilization experiments have taken place2. Thus, we established a phosphorus, nitrogen and base cation addition experiment in an old growth Amazon rainforest, with a low soil phosphorus content that is representative of approximately 60% of the Amazon basin. Here we show that net primary productivity increased exclusively with phosphorus addition. After 2 years, strong responses were observed in fine root (+29%) and canopy productivity (+19%), but not stem growth. The direct evidence of phosphorus limitation of net primary productivity suggests that phosphorus availability may restrict Amazon forest responses to CO2 fertilization4, with major implications for future carbon sequestration and forest resilience to climate change.The authors acknowledge funding from the UK Natural Environment Research Council (NERC), grant number NE/L007223/1. This is publication 850 in the technical series of the BDFFP. C.A.Q. acknowledges the grants from Brazilian National Council for Scientific and Technological Development (CNPq) CNPq/LBA 68/2013, CNPq/MCTI/FNDCT no. 18/2021 and his productivity grant. C.A.Q., H.F.V.C., F.D.S., I.A., L.F.L., E.O.M. and S.G. acknowledge the AmazonFACE programme for financial support in cooperation with Coordination for the Improvement of Higher Education Personnel (CAPES) and the National Institute of Amazonian Research as part of the grants CAPES-INPA/88887.154643/2017-00 and 88881.154644/2017-01. T.F.D. acknowledges funds from FundacAo de Amparo a Pesquisa do Estado de SAo Paulo (FAPESP), grant 2015/50488-5, and the Partnership for Enhanced Engagement in Research (PEER) programme grant AID-OAA-A-11-00012. L.E.O.C.A. thanks CNPq (314416/2020-0)
Reconciling Deep Calibration and Demographic History: Bayesian Inference of Post Glacial Colonization Patterns in Carcinus aestuarii (Nardo, 1847) and C. maenas (Linnaeus, 1758)
A precise inference of past demographic histories including dating of demographic events using Bayesian methods can only be achieved with the use of appropriate molecular rates and evolutionary models. Using a set of 596 mitochondrial cytochrome c oxidase I (COI) sequences of two sister species of European green crabs of the genus Carcinus (C. maenas and C. aestuarii), our study shows how chronologies of past evolutionary events change significantly with the application of revised molecular rates that incorporate biogeographic events for calibration and appropriate demographic priors. A clear signal of demographic expansion was found for both species, dated between 10,000 and 20,000 years ago, which places the expansions events in a time frame following the Last Glacial Maximum (LGM). In the case of C. aestuarii, a population expansion was only inferred for the Adriatic-Ionian, suggestive of a colonization event following the flooding of the Adriatic Sea (18,000 years ago). For C. maenas, the demographic expansion inferred for the continental populations of West and North Europe might result from a northward recolonization from a southern refugium when the ice sheet retreated after the LGM. Collectively, our results highlight the importance of using adequate calibrations and demographic priors in order to avoid considerable overestimates of evolutionary time scales
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