1,371 research outputs found
Weak antilocalization in quasi-two-dimensional electronic states of epitaxial LuSb thin films
Observation of large non-saturating magnetoresistance in rare-earth
monopnictides has raised enormous interest in understanding the role of its
electronic structure. Here, by a combination of molecular-beam epitaxy,
low-temperature transport, angle-resolved photoemssion spectroscopy, and hybrid
density functional theory we have unveiled the bandstructure of LuSb, where
electron-hole compensation is identified as a mechanism responsible for large
magnetoresistance in this topologically trivial compound. In contrast to bulk
single crystal analogues, quasi-two-dimensional behavior is observed in our
thin films for both electron and holelike carriers, indicative of dimensional
confinement of the electronic states. Introduction of defects through growth
parameter tuning results in the appearance of quantum interference effects at
low temperatures, which has allowed us to identify the dominant inelastic
scattering processes and elucidate the role of spin-orbit coupling. Our
findings open up new possibilities of band structure engineering and control of
transport properties in rare-earth monopnictides via epitaxial synthesis.Comment: 20 pages, 12 figures; includes supplementary informatio
Levantamento da ocorrĂȘncia da pinta preta dos citrus (Guignardia citricarpa) em RondĂŽnia.
A pinta-preta ou mancha preta Ă© uma doença fĂșngica que ataca o limoeiro. Sua manifestação Ă© percebida nos frutos de limĂŁo que, por estarem danificados, sĂŁo depreciados no mercado interno e externo. Com o objetivo de realizar um levantamento epidemiolĂłgico desta doença no estado de RondĂŽnia, este trabalho resulta de uma ação conjunta entre a AgĂȘncia de Defesa Agrossilvopastoril de RondĂŽnia â IDARON e a Embrapa RondĂŽnia, para nĂŁo apenas verificar a existĂȘncia da doença no estado, mas tambĂ©m determinar o tamanho da sua abrangĂȘncia dentro dos principais polos produtores de citros no Estado.bitstream/item/46585/1/cot360-citrus.pd
Specific heat and magnetic measurements in Nd0.5Sr0.5MnO3, Nd0.5Ca0.5MnO3 and Ho0.5Ca0.5MnO3 samples
We studied the magnetization as a function of temperature and magnetic field
in the compounds Nd0.5Sr0.5MnO3, Nd0.5Ca0.5MnO3 and Ho0.5Ca0.5MnO3. It allowed
us to identify the ferromagnetic, antiferromagnetic and charge ordering phases
in each case. The intrinsic magnetic moments of Nd3+ and Ho3+ ions experienced
a short range order at low temperatures. We also did specific heat measurements
with applied magnetic fields between 0 and 9 T and temperatures between 2 and
300 K in all three samples. Close to the charge ordering and ferromagnetic
transition temperatures the specific heat curves showed peaks superposed to the
characteristic response of the lattice oscillations. Below 10 K the specific
heat measurements evidenced a Schottky-like anomaly for all samples. However,
we could not successfully fit the curves to either a two level nor a
distribution of two-level Schottky anomaly. Our results indicated that the peak
temperature of the Schottky anomaly was higher in the compounds with narrower
conduction band.Comment: submitted to PR
Low-Level Laser Application in the Early Myocardial Infarction Stage Has No Beneficial Role in Heart Failure
Low-level laser therapy (LLLT) has been targeted as a promising approach that can mitigate post infarction cardiac remodeling. There is some interesting evidence showing that the beneficial role of the LLLT could persist long-term even after the end of the application, but it remains to be systematically evaluated. Therefore, the present study aimed to test the hypothesis that LLLT beneficial effects in the early post-infarction cardiac remodeling could remain in overt heart failure even with the disruption of irradiations. Female Wistar rats were subjected to the coronary occlusion to induce myocardial infarction or Sham operation. A single LLLT application was carried out after 60 s and 3 days post-coronary occlusion, respectively. Echocardiography was performed 3 days and at the end of the experiment (5 weeks) to evaluate cardiac function. After the last echocardiographic examination. LV hemodynamic evaluation was performed at baseline and on sudden afterload increases. Compared with the Sham group, infarcted rats showed increased systolic and diastolic internal diameter as well as a depressed shortening fraction of LV. The only benefit of the LLLT was a higher shortening fraction after 3 days of infarction. However, treated-LLLT rats show a lower shortening fraction in the 5th week of study when compared with Sham and non-irradiated rats. A worsening of cardiac function was confirmed in the hemodynamic analysis as evidenced by the higher LV end-diastolic pressure and lower +dP/dt and dP/dt with five weeks of study. Cardiac functional reserve was also impaired by infarction as evidenced by an attenuated response of stroke work index and cardiac output to a sudden afterload stress, without LLLT repercussions. No significant differences were found in the myocardial expression of Akti NEGF pathway. Collectively, these findings illustrate that LLLT improves LV systolic function in the early post-infarction cardiac remodeling. However, this beneficial effect may be dependent on the maintenance of phototherapy. Long-term studies with LLLT application are needed to establish whether these effects ultimately translate into improved cardiac remodeling.Conselho Nacional de Desenvolvimento Cientifico e TecnologicoFAPESPNove de Julho Univ, Lab Biophoton, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Lab Cardiac Physiol, Sao Paulo, SP, BrazilNove de Julho Univ, Program Med, Sao Paulo, BrazilUniv Sao Judas Tadeu, Brazil Phys Educ & Aging Sci Program, Translat Physiol Lab, Sao Paulo, BrazilUniv Fed Sao Paulo, Lab Cardiac Physiol, Sao Paulo, SP, BrazilCNPq: 4400851/2014-8FAPESP: 09-54225/8FAPESP: 15/11028-9Web of Scienc
Perspectives on the Trypanosoma cruzi-host cell receptor interaction
Chagas disease is caused by the parasite Trypanosoma cruzi. The critical initial event is the interaction of the trypomastigote form of the parasite with host receptors. This review highlights recent observations concerning these interactions. Some of the key receptors considered are those for thromboxane, bradykinin, and for the nerve growth factor TrKA. Other important receptors such as galectin-3, thrombospondin, and laminin are also discussed. Investigation into the molecular biology and cell biology of host receptors for T. cruzi may provide novel therapeutic targets
Intragenic antimicrobial peptides (IAPs) from human proteins with potent antimicrobial and anti-inflammatory activity
Following the treads of our previous works on the unveiling of bioactive peptides encrypted
in plant proteins from diverse species, the present manuscript reports the occurrence of four
proof-of-concept intragenic antimicrobial peptides in human proteins, named Hs IAPs.
These IAPs were prospected using the software Kamal, synthesized by solid phase chemistry,
and had their interactions with model phospholipid vesicles investigated by differential
scanning calorimetry and circular dichroism. Their antimicrobial activity against bacteria,
yeasts and filamentous fungi was determined, along with their cytotoxicity towards erythrocytes.
Our data demonstrates that Hs IAPs are capable to bind model membranes while
attaining α-helical structure, and to inhibit the growth of microorganisms at concentrations
as low as 1ÎŒM. Hs02, a novel sixteen residue long internal peptide (KWAVRIIRKFIKGFISNH2)
derived from the unconventional myosin 1h protein, was further investigated in its
capacity to inhibit lipopolysaccharide-induced release of TNF-α in murine macrophages.
Hs02 presented potent anti-inflammatory activity, inhibiting the release of TNF-α in LPSprimed
cells at the lowest assayed concentration, 0.1 ÎŒM. A three-dimensional solution
structure of Hs02 bound to DPC micelles was determined by Nuclear Magnetic Resonance.
Our work exemplifies how the human genome can be mined for molecules with biotechnological
potential in human health and demonstrates that IAPs are actual alternatives to antimicrobial
peptides as pharmaceutical agents or in their many other putative applications
Criminalidade organizada nas prisÔes e os ataques do PCC
The advent of organized crime in Brazilian prisons, especially in the state of SĂŁo Paulo, constitutes the object of this article. The waves of attack unleashed by the Capital's First Command (PCC - Primeiro Comando da Capital), in May 2006, which resulted in countless deaths, brought cities to a halt, and cornered authorities in charge preventing them from applying law and order are the starting as well as reference points taken. The advent of organized criminality is analyzed under the light of determined axes: the international scenario and the Brazilian context, the historical antecedents, the taking root of crime in society and the role of penitentiary public policies.A emergĂȘncia da criminalidade organizada nas prisĂ”es brasileiras, em especial no Estado de SĂŁo Paulo, constitui objeto deste artigo. Tomam-se como ponto de partida e referĂȘncia para anĂĄlise as ondas de ataques desencadeadas pelo Primeiro Comando da Capital (PCC), de maio a agosto de 2006, que resultaram em inĂșmeros mortos, paralisaram cidades e acuaram as autoridades encarregadas de aplicar lei e ordem. A emergĂȘncia da criminalidade organizada Ă© analisada sob eixos determinados: cenĂĄrio internacional e contexto brasileiro, antecedentes histĂłricos, enraizamento do crime na sociedade e papel das polĂticas pĂșblicas penitenciĂĄrias
Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC
The uncertainty on the calorimeter energy response to jets of particles is
derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the
calorimeter response to single isolated charged hadrons is measured and
compared to the Monte Carlo simulation using proton-proton collisions at
centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009
and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter
response to specific types of particles (positively and negatively charged
pions, protons, and anti-protons) is measured and compared to the Monte Carlo
predictions. Finally, the jet energy scale uncertainty is determined by
propagating the response uncertainty for single charged and neutral particles
to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3%
for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table,
submitted to European Physical Journal
Measurement of Ï c1 and Ï c2 production with sâ = 7 TeV pp collisions at ATLAS
The prompt and non-prompt production cross-sections for the Ï c1 and Ï c2 charmonium states are measured in pp collisions at sâ = 7 TeV with the ATLAS detector at the LHC using 4.5 fbâ1 of integrated luminosity. The Ï c states are reconstructed through the radiative decay Ï c â J/ÏÎł (with J/Ï â ÎŒ + ÎŒ â) where photons are reconstructed from Îł â e + e â conversions. The production rate of the Ï c2 state relative to the Ï c1 state is measured for prompt and non-prompt Ï c as a function of J/Ï transverse momentum. The prompt Ï c cross-sections are combined with existing measurements of prompt J/Ï production to derive the fraction of prompt J/Ï produced in feed-down from Ï c decays. The fractions of Ï c1 and Ï c2 produced in b-hadron decays are also measured
Measurement of the production of a W boson in association with a charm quark in pp collisions at âs = 7 TeV with the ATLAS detector
The production of a W boson in association with a single charm quark is studied using 4.6 fbâ1 of pp collision data at sâ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26â0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio Ï(W + +cÂŻÂŻ)/Ï(W â + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the sâsÂŻÂŻÂŻ quark asymmetry
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