453 research outputs found
Chirped polymer optical fiber Bragg grating sensors
We report chirped fiber Bragg gratings (CFBGs) photo-inscribed in undoped PMMA polymer optical fibre (POF) for the first time. The chirped polymer optical fiber Bragg gratings (CPOFBGs) were inscribed using an UV KrF excimer laser operating at 248 nm. The rectangular gauss laser beam was expanded to 25 mm in horizontal direction along the fiber core by a cylindrical lens, giving a total of 25 mm grating length. A 25 mm long chirped phase mask chosen for 1550 nm grating inscription was used. The laser frequency was 1 Hz with an energy of 5 mJ per exposure, exposing few pulses for each grating inscription. The reflection amplitude spectrum evolution of a CPOFBG is investigated as a function of the applied strain and temperature. Also, some results regarding to group delay are collected and discussed. These results pave the way to further developments in different fields, where POFs could present some advantages preferably replacing their silica counterparts
The kinetics of chondroitin 4-sulfate release from stimulated platelets and its relation to thromboxane A2 formation and granule secretion
1. In platelet rich plasma (PRP), chondroitin 4-sulfate release from platelets occurred after stimulation with ADP (5 microM), collagen (5-10 micrograms/ml), or adrenaline (10 microM). Release started within 60 s and maximum release (0.7-2.0 mg/l) was reached within 180 s. TXA2 formation and dense granule release reached a maximum within 90 s after stimulation. 2. Using washed platelets (1.5 x 10(8) cells/ml), the platelet responses were faster. Release of chondroitin 4-sulfate and TXA2 started within 20-30 s after thrombin addition (100 mU/ml). Maximum release was reached within 60 s in both cases. Dense granule release started in the first 5 s of stimulation (34.6 +/- 12.4%) reaching maximum secretion (74.4 +/- 8.7%) within 60 s. 3. Our results demonstrate that maximal chondroitin 4-sulfate release occurs after the dense granule release reaction in both PRP and washed platelets. This observation suggests that chondroitin 4-sulfate is unlikely to be stored in the dense granules but may be stored in the alpha-granules.In platelet rich plasma (PRP), chondroitin 4-sulfate release from platelets occurred after stimulation with ADP (5 microM), collagen (5-10 micrograms/ml), or adrenaline (10 microM). Release started within 60 s and maximum release (0.7-2.0 mg/l) was reached within 180 s. TXA2 formation and dense granule release reached a maximum within 90 s after stimulation. 2. Using washed platelets (1.5 x 10(8) cells/ml), the platelet responses were faster. Release of chondroitin 4-sulfate and TXA2 started within 20-30 s after thrombin addition (100 mU/ml). Maximum release was reached within 60 s in both cases. Dense granule release started in the first 5 s of stimulation (34.6 +/- 12.4%) reaching maximum secretion (74.4 +/- 8.7%) within 60 s. 3. Our results demonstrate that maximal chondroitin 4-sulfate release occurs after the dense granule release reaction in both PRP and washed platelets. This observation suggests that chondroitin 4-sulfate is unlikely to be stored in the dense granules but may be stored in the alpha-granules2792163216
Avaliação da atividade fenilalanina amônia liåsica em folhas de bananeira inoculadas com o fungo Mycosphaerella fijiensis.
O objetivo deste trabalho foi avaliar os atributos bioquĂmicos envolvidos na defesa da bananeira ao ataque do fungo M. fijiensis, notadamente avaliar o papel da enzima fenilalanina amĂ´nia liase nesta resposta, nas variedades Caprichosa, Garantida, FHIA-18, Prata Ken, Prata AnĂŁ, Maçã e Grande Naine, nos tempos: 0, 6h, 24h, 48h, 72h dias apĂłs a inoculação. ApĂłs a coleta, as folhas foram pesadas e obtidos os extratos totais por meio de maceração das folhas com tampĂŁo acetato de sĂłdio 50 mM, pH 5,2, os quais foram utilizados nas determinaçþes de proteĂnas e atividade enzimĂĄtica
How to dissect viral infections and their interplay with the host-proteome by immunoaffinity and mass spectrometry: A tutorial
The capabilities of bioanalytical mass spectrometry to (i) detect and differentiate viruses at the peptide level whilst maintaining high sample throughput and (ii) to provide diagnosis and prognosis for infected patients are presented as a tutorial in this work to aid analytical chemists and physicians to gain insights into the possibilities offered by current high-resolution mass spectrometry technology and bioinformatics. From (i) sampling to sample treatment; (ii) Matrix-Assisted Laser Desorption Ionization- to Electrospray Ionization -based mass spectrometry; and (iii) from clustering to peptide sequencing; a detailed step-by-step guide is provided and exemplified using SARS-CoV-2 Spike Y839 variant and the variant of concern SARS-CoV-2 Alpha (B.1.1.7 lineage), Influenza B, and Influenza A subtypes AH1N1pdm09 and AH3N2.Highlights: - Immunohistochemistry with magnetic core nanoparticles to isolate viruses. - The use of MALDI-MS for rapid virus detection is explained in detail; - The use of ESI-MS/MS to pinpoint host-patient crosstalk is explained in detail. - The absolute quantitative MS is explained for large-scale protein quantitation.This work received financial support from PT national funds (FCT/MCTES) through the projects UIDB/50006/2020 and UIDP/50006/2020 and from PROTEOMASS Scientific Society through the projects #PM001/2019 and #PM003/2016.info:eu-repo/semantics/publishedVersio
Debate sobre o artigo de Narvai et al.
English title: Debate on the paper by Narvai et al.Margareth CrisĂłstomo Portela & Mauricio Teixeira Leite de Vasconcello
Quebra de dormência de pereira 'Hosui' com uso de óleo mineral em dois tipos de condução
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV
The Lambda(b) differential production cross section and the cross section
ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum
pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7
TeV using data collected by the CMS experiment at the LHC. The measurements are
based on Lambda(b) decays reconstructed in the exclusive final state J/Psi
Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and
Lambda to proton pion, using a data sample corresponding to an integrated
luminosity of 1.9 inverse femtobarns. The product of the cross section times
the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls
faster than that of b mesons. The measured value of the cross section times the
branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06
+/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for
anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are
statistical and systematic, respectively.Comment: Submitted to Physics Letters
- âŚ