769 research outputs found

    Validation of Coffee seed promoter in Nicotiana tabacum

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    Promoters that restrict transgenic expressions in a specific organ or tissue and, at a certain stage of plant development or in response to stress are extremely desirable for the improvement of agronomic species by transgenesis. Coffee is among the five most valuable crops to developing nations, and its production is of great economic interest to Brazil. Commercial production is based mainly on the specie Coffea arabica, which is tetraploid, perennial and has low genetic variability, impairing the genetic improvement by traditional methods. Thus, genetic modification appears as a good way to obtain coffee plants more suitable for different purposes. The aim of this work was to isolate an active promoter from endosperm of coffee seeds. Initially, a contig preferentially expressed in coffee fruits was identified by Electronic Northern, using the database of the Brazilian Coffee Genome Project. The organ specificity of the transcript was confirmed in fruit, particularly in seed endosperm, by RT-PCR, RT-qPCR and Northern blot. Then, the promoter was isolated by the 5' RACE method using the Universal Genome Walker Kit (Clontech). A fragment of 1.2 kb and three truncated versions (407 bp, 785 bp and 1.0 kb) were isolated, starting at the first ATG codon of the protein, in order to evaluate the expression profile of different modules. The sequences were in silico analyzed and all fragments exhibited promoter-specific cis elements. In the present work we constructed expression cassettes in which the four versions of the promoter were cloned in the binary vector pBI121 by replacing the 35S promoter that regulates the ?-glucuronidase (uidA/gus) gene. The constructed binary vectors were used to transform tobacco (Nicotiana tabacum) through Agrobacterium tumefaciens. Histochemical analysis of GUS activity show that the 1.2 kb, 1.0 kb e 785 pb fragments promotes expression in leaves, flowers and fruits, with differences in the activity level, and all three fragments have low activity in roots. Finally, the 407 bp fragment promotes the expression of Gus only in tobacco seeds. Future work will be performed to determine in which seed tissue this promoter is active and which domains are involved in the tissue-specificity. (Texte intégral

    On Aharonov-Casher bound states

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    In this work bound states for the Aharonov-Casher problem are considered. According to Hagen's work on the exact equivalence between spin-1/2 Aharonov-Bohm and Aharonov-Casher effects, is known that the E\boldsymbol{\nabla}\cdot\mathbf{E} term cannot be neglected in the Hamiltonian if the spin of particle is considered. This term leads to the existence of a singular potential at the origin. By modeling the problem by boundary conditions at the origin which arises by the self-adjoint extension of the Hamiltonian, we derive for the first time an expression for the bound state energy of the Aharonov-Casher problem. As an application, we consider the Aharonov-Casher plus a two-dimensional harmonic oscillator. We derive the expression for the harmonic oscillator energies and compare it with the expression obtained in the case without singularity. At the end, an approach for determination of the self-adjoint extension parameter is given. In our approach, the parameter is obtained essentially in terms of physics of the problem.Comment: 11 pages, matches published versio

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Conservative Treatment Of The Dentigerous Cyst: Report Of Two Cases

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    The purpose of this paper is to present two cases of dentigerous cyst associated to permanent teeth in children treated by conservative techniques. Dentigerous cyst is the most common developmental cysts of the jaws. Conservative treatment is very effective to this entity and aims at eliminating the cystic tissue and preserving the permanent tooth involved in the pathology. Two techniques are described as conservative treatment for these cysts, marsupialization and the decompression. Two children presented with dentigerous cysts. A female child was affected by a large lesion at the right side of the mandible associated to tooth 45. The other lesion arose at the left maxilla associated to tooth 21 of a male child. Each dentigerous cyst promoted severe tooth displacement. The first patient was treated with decompression and the second with marsupialization.1215256Kumar, R., Singh, R.K., Pandey, R.K., Mohammad, S., Ram, H., Inflammatory dentigerous cyst in a ten-year-old child (2012) Natl J Maxillofac Surg, 3, pp. 80-83Pinheiro, R.S., Castro, G.F., Roter, M., Netto, R., Meirelles Jr., V., Janini, M.E., An unusual dentigerous cyst in a young child (2013) Gen Dent, 61, pp. 62-64Picciotti, M., Divece, L., Parrini, S., Pettini, M., Lorenzini, G., Replantation of tooth involved in dentigerous cyst: a case report (2012) Eur J Paediatr Dent, 13, pp. 349-351Marwah, N., Bishen, K.A., Prabha, V., Goenka, P., A conservative approach in the management of inflammatory dentigerous cyst in transitional dentition: a case report (2012) Eur J Paediatr Dent, 13, pp. 349-351Benn, A., Altini, M., Dentigerous cysts of inflammatory origin A clinicopathologic study (1996) Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 81, pp. 203-209de Matos, F.R., Nonaka, C.F., Pinto, L.P., de Souza, L.B., de Almeida Freitas, R., Adenomatoid odontogenic tumor: retrospective study of 15 cases with emphasis on histopathologic features (2012) Head Neck Pathol, 6, pp. 430-437Lima, G.S., Fontes, S.T., de Araújo, L.M., Etges, A., Tarquinio, S.B., Gomes, A.P., A survey of oral and maxillofacial biopsies in children: a single-center retrospective study of 20 years in Pelotas-Brazil (2008) J Appl Oral Sci, 16, pp. 397-402Hyomoto, M., Kawakami, M., Inoue, M., Kirita, T., Clinical conditions for eruption of maxillary canines and mandibular premolars associated with dentigerous cysts (2003) Am J Orthod Dentofac Orthop, 124, pp. 515-520Horowitz, R.A., Giannasca, P.J., Woodcock, C.L., Ultrastructural preservation of nuclei and chromatin: improvement with low-temperature methods (1990) J Microsc, 157, pp. 205-224Benichou, G., Tonsho, M., Tocco, G., Nadazdin, O., Madsen, J.C., Innate immunity and resistance to tolerogenesis in allotransplantation (2012) Front Immunol, 3, p. 73Gervasio, A.M., Silva, D.A., Taketomi, E.A., Souza, C.J., Sung, S.S., Loyola, A.M., Levels of GM-CSF, IL-3, and IL-6 in fluid and tissue from human radicular cysts (2005) J Dent Res, 81, pp. 64-68Takagi, S., Koyama, S., Guided eruption of an impacted second premolar associated with a dentigerous cyst in the maxillary sinus of a 6-year-old child (1999) J Oral Maxillofac Surg, 56, pp. 237-245Miyawaki, S., Hyomoto, M., Tsubauchi, J., Eruption speed and rate of angulation change of a cyst-associated mandibular second premolar after marsupialization of a dentigerous cyst (1999) Am J Orthod Dentofac Orthop, 116, pp. 578-58

    Engineering hydrophobically modified chitosan for enhancing the dispersion of respirable microparticles of levofloxacin

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    The potential of amphiphilic chitosan formed by grafting octanoyl chains on the chitosan backbone for pulmonary delivery of levofloxacin has been studied. The success of polymer synthesis was confirmed using FT-IR and NMR, whilst antimicrobial activity was assessed against Pseudomonas aeruginosa. Highly dispersible dry powders for delivery as aerosols were prepared with different amounts of chitosan and octanoyl chitosan to study the effect of hydrophobic modification and varying concentration of polymer on aerosolization of drug. Powders were prepared by spray-drying from an aqueous solution containing levofloxacin and chitosan/amphiphilic octanoyl chitosan. L-leucine was also used to assess its effect on aerosolization. Following spray-drying, the resultant powders were characterized using scanning electron microscopy, laser diffraction, dynamic light scattering, HPLC, differential scanning calorimetry, thermogravimetric analysis and X-ray powder diffraction. The in vitro aerosolization profile was determined using a Next Generation Impactor, whilst in vitro antimicrobial assessment was performed using MIC assay. Microparticles of chitosan have the property of mucoadhesion leading to potential increased residence time in the pulmonary mucus, making it important to test the toxicity of these formulations. In-vitro cytotoxicity evaluation using MTT assay was performed on A549 cell line to determine the toxicity of formulations and hence feasibility of use. The MTT assay confirmed that the polymers and the formulations were non-cytotoxic. Hydrophobically modifying chitosan showed significantly lower MIC (4-fold) than the commercial chitosan against P. aeruginosa. The powders generated were of suitable aerodynamic size for inhalation having a mass median aerodynamic diameter less than 4.5 lm for formulations containing octanoyl chitosan. These highly dispersible powders have minimal moisture adsorption and hence an emitted dose of more than 90% and a fine particle fraction (FPF) of 52%. Powders with non-modified chitosan showed lower dispersibility, with an emitted dose of 72% and FPF of 20%, as a result of high moisture adsorption onto the chitosan matrix leading to cohesiveness and subsequently decreased dispersibility

    Measurement of the correlation between flow harmonics of different order in lead-lead collisions at √sNN = 2.76 TeV with the ATLAS detector

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    Correlations between the elliptic or triangular flow coefficients vm (m=2 or 3) and other flow harmonics vn (n=2 to 5) are measured using √sNN=2.76 TeV Pb+Pb collision data collected in 2010 by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 7 μb−1. The vm−vn correlations are measured in midrapidity as a function of centrality, and, for events within the same centrality interval, as a function of event ellipticity or triangularity defined in a forward rapidity region. For events within the same centrality interval, v3 is found to be anticorrelated with v2 and this anticorrelation is consistent with similar anticorrelations between the corresponding eccentricities, ε2 and ε3. However, it is observed that v4 increases strongly with v2, and v5 increases strongly with both v2 and v3. The trend and strength of the vm−vn correlations for n=4 and 5 are found to disagree with εm−εn correlations predicted by initial-geometry models. Instead, these correlations are found to be consistent with the combined effects of a linear contribution to vn and a nonlinear term that is a function of v22 or of v2v3, as predicted by hydrodynamic models. A simple two-component fit is used to separate these two contributions. The extracted linear and nonlinear contributions to v4 and v5 are found to be consistent with previously measured event-plane correlations

    Search for W′→tb→qqbb decays in pp collisions at √s=8 TeV with the ATLAS detector

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    A search for a massive W′ gauge boson decaying to a top quark and a bottom quark is performed with the ATLAS detector in pp collisions at the LHC. The dataset was taken at a centre-of-mass energy of √s=8 TeV and corresponds to 20.3 fb−1 of integrated luminosity. This analysis is done in the hadronic decay mode of the top quark, where novel jet substructure techniques are used to identify jets from high-momentum top quarks. This allows for a search for high-mass W′ bosons in the range 1.5–3.0 TeV. b-tagging is used to identify jets originating from b-quarks. The data are consistent with Standard Model background-only expectations, and upper limits at 95 % confidence level are set on the W′→tb cross section times branching ratio ranging from 0.16pb to 0.33pb for left-handed W′ bosons, and ranging from 0.10pb to 0.21pb for W′ bosons with purely right-handed couplings. Upper limits at 95 % confidence level are set on the W′-boson coupling to tb as a function of the W′ mass using an effective field theory approach, which is independent of details of particular models predicting a W′boson

    Measurement of the cross section for isolated-photon plus jet production in pp collisions at √s=13 TeV using the ATLAS detector

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    The dynamics of isolated-photon production in association with a jet in proton–proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb−1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon–jet invariant mass and the scattering angle in the photon–jet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements

    Search for vectorlike B quarks in events with one isolated lepton, missing transverse momentum, and jets at √s = 8 TeV with the ATLAS detector

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    A search has been performed for pair production of heavy vectorlike down-type (B) quarks. The analysis explores the lepton-plus-jets final state, characterized by events with one isolated charged lepton (electron or muon), significant missing transverse momentum, and multiple jets. One or more jets are required to be tagged as arising from b quarks, and at least one pair of jets must be tagged as arising from the hadronic decay of an electroweak boson. The analysis uses the full data sample of pp collisions recorded in 2012 by the ATLAS detector at the LHC, operating at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3 fb −1 . No significant excess of events is observed above the expected background. Limits are set on vectorlike B production, as a function of the B branching ratios, assuming the allowable decay modes are B → Wt/Zb/Hb. In the chiral limit with a branching ratio of 100% for the decay B → Wt, the observed (expected) 95% C.L. lower limit on the vectorlike B mass is 810 GeV (760 GeV). In the case where the vectorlike B quark has branching ratio values corresponding to those of an SU(2) singlet state, the observed (expected) 95% C.L. lower limit on the vectorlike B mass is 640 GeV (505 GeV). The same analysis, when used to investigate pair production of a colored, charge 5/3 exotic fermion T 5/3 , with subsequent decay T 5/3 → Wt, sets an observed (expected) 95% C.L. lower limit on the T 5/3 mass of 840 GeV (780 GeV)

    Óleo essencial de Baccharis tridentata Vahl: composição química, atividade antioxidante e fungitóxica, e caracterização morfológica das estruturas secretoras por microscopia eletrônica de varredura

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    Este trabalho teve como objetivos avaliar a composição química do óleo essencial de Baccharis tridentata Vahl, as atividades antioxidante e fungitóxica, e estudar a morfologia das estruturas secretoras do óleo essencial presentes na superfície foliar por meio de microscopia eletrônica de varredura (MEV). A extração do óleo essencial foi realizada por hidrodestilação, as análises quantitativas e qualitativas foram executadas por meio de cromatografia em fase gasosa com detector de ionização de chamas (FID) e acoplada à espectrometria de massas, respectivamente. A atividade antioxidante foi realizada empregando-se os métodos de redução do radical estável DPPH e o ensaio de oxidação do sistema β-caroteno/ácido linoleico. As atividades fungitóxicas foram avaliadas utilizando o teste bioanalítico in vitro, sobre a inibição do crescimento micelial dos fitopatógenos Fusarium oxysporum, Colletotrichum gloeosporioides e Rhizoctonia solani. A composição química revelou a presença de 28 compostos, sendo o α-tujeno (22,93%) o constituinte majoritário; não foi observada atividade antioxidante por meio dos ensaios utilizados, no entanto, observou-se atividade fungitóxica sobre o crescimento micelial dos fitopatógenos estudados. Já os estudos da superfície foliar por MEV revelaram a presença de tricomas glandulares em ambas as superfícies abaxial e adaxial.</jats:p
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