653 research outputs found
Coherent Control of Quantum Dynamics with Sequences of Unitary Phase-Kick Pulses
Coherent optical control schemes exploit the coherence of laser pulses to
change the phases of interfering dynamical pathways in order to manipulate
dynamical processes. These active control methods are closely related to
dynamical decoupling techniques, popularized in the field of Quantum
Information. Inspired by Nuclear Magnetic Resonance (NMR) spectroscopy,
dynamical decoupling methods apply sequences of unitary operations to modify
the interference phenomena responsible for the system dynamics thus also
belonging to the general class of coherent control techniques. Here we review
related developments in the fields of coherent optical control and dynamical
decoupling, with emphasis on control of tunneling and decoherence in general
model systems. Considering recent experimental breakthroughs in the
demonstration of active control of a variety of systems, we anticipate that the
reviewed coherent control scenarios and dynamical decoupling methods should
raise significant experimental interest.Comment: 52 pages, 7 figure
In vivo activity of Sapindus saponaria against azole-susceptible and -resistant human vaginal Candida species
<p>Abstract</p> <p>Background</p> <p>Study of <it>in vivo </it>antifungal activity of the hydroalcoholic extract (HE) and n-BuOH extract (BUTE) of <it>Sapindus saponaria </it>against azole-susceptible and -resistant human vaginal <it>Candida </it>spp.</p> <p>Methods</p> <p>The <it>in vitro </it>antifungal activity of HE, BUTE, fluconazole (FLU), and itraconazole (ITRA) was determined by the broth microdilution method. We obtained values of minimal inhibitory concentration (MIC) and minimum fungicide concentration (MFC) for 46 strains of <it>C. albicans </it>and 10 of <it>C. glabrata </it>isolated from patients with vulvovaginal candidiasis (VVC). VVC was induced in hyperestrogenic Wistar rats with azole-susceptible <it>C. albicans </it>(SCA), azole-resistant <it>C. albicans </it>(RCA), and azole-resistant <it>C. glabrata </it>(RCG). The rats were treated intravaginally with 0.1 mL of HE or BUTE at concentrations of 1%, 2.5% and 5%; 100 ÎŒg/mL of FLU (treatment positive control); or distilled water (negative control) at 1, 24, and 48 h after induction of the infection, and the progress of VVC was monitored by culturing and scanning electron microscopy (SEM). The toxicity was evaluated in cervical cells of the HeLa cell line.</p> <p>Results</p> <p>The extracts showed <it>in vitro </it>inhibitory and fungicidal activity against all the isolates, and the MIC and MFC values for the <it>C. glabrata </it>isolates were slightly higher. <it>In vivo</it>, the SCA, RCA, and RCG infections were eliminated by 21 days post-infection, with up to 5% HE and BUTE, comparable to the activity of FLU. No cytotoxic action was observed for either extract.</p> <p>Conclusions</p> <p>Our results demonstrated that HE and BUTE from <it>S. saponaria </it>show inhibitory and fungicidal activity <it>in vitro</it>, in addition to <it>in vivo </it>activity against azole-resistant vaginal isolates of <it>C. glabrata </it>and azole-susceptible and resistant isolates of <it>C. albicans</it>. Also considering the lack of cytotoxicity and the low concentrations of the extracts necessary to eliminate the infection <it>in vivo</it>, HE and BUTE show promise for continued studies with purified antifungal substances in VVC yeast isolates.</p
The small GTPase Rab29 is a common regulator of immune synapse assembly and ciliogenesis
Acknowledgements We wish to thank Jorge GalĂĄn, Gregory Pazour, Derek Toomre, Giuliano Callaini, Joel Rosenbaum, Alessandra Boletta and Francesco Blasi for generously providing reagents and for productive discussions, and Sonia Grassini for technical assistance. The work was carried out with the financial support of Telethon (GGP11021) and AIRC.Peer reviewedPostprin
Efimov effect in quantum magnets
Physics is said to be universal when it emerges regardless of the underlying
microscopic details. A prominent example is the Efimov effect, which predicts
the emergence of an infinite tower of three-body bound states obeying discrete
scale invariance when the particles interact resonantly. Because of its
universality and peculiarity, the Efimov effect has been the subject of
extensive research in chemical, atomic, nuclear and particle physics for
decades. Here we employ an anisotropic Heisenberg model to show that collective
excitations in quantum magnets (magnons) also exhibit the Efimov effect. We
locate anisotropy-induced two-magnon resonances, compute binding energies of
three magnons and find that they fit into the universal scaling law. We propose
several approaches to experimentally realize the Efimov effect in quantum
magnets, where the emergent Efimov states of magnons can be observed with
commonly used spectroscopic measurements. Our study thus opens up new avenues
for universal few-body physics in condensed matter systems.Comment: 7 pages, 5 figures; published versio
Novel highly emissive non proteinogenic amino acids : synthesis of 1,3,4-thiadiazolyl asparagines and evaluation as fluorimetric chemosensors for biologically relevant transition metal cations
Highly emissive heterocyclic asparagine derivatives bearing a 1,3,4-thiadiazolyl unit at the side chain, functionalised with electron donor or acceptor groups, were synthesised and evaluated as amino acid based fluorimetric chemosensors for metal cations such as Cu2+, Zn2+, Co2+ and Ni2+. The results suggest that there is a strong interaction through the donor heteroatoms at the side chain of the various asparagine derivatives, with high sensitivity towards Cu2+ in a ligand-metal complex with 1:2 stoichiometry. Association constants and detection limits for Cu2+ were calculated. The photophysical and metal ion sensing properties of these asparagine derivatives confirm their potential as fluorimetric chemosensors and suggest that they can be suitable for incorporation into chemosensory peptidic frameworks.Fundação para a CiĂȘncia e a Tecnologia (FCT) - PTDC/QUI/66250/2006 (FCOMP-01-0124-FEDER-007428
Use of a polyphasic approach including MALDI-TOF MS for identification of Aspergillus section Flavi strains isolated from food commodities in Brazil
Brazil is one the largest producers and exporters of food commodities in the world. The evaluation of fungi capable of spoilage and the production mycotoxins in these commodities is an important issue that can be of help in bioeconomic development. The present work aimed to identify fungi of the genus Aspergillus section Flavi isolated from different food commodities in Brazil. Thirty-five fungal isolates belonging to the section Flavi were identified and characterised. Different classic phenotypic and genotypic methodologies were used, as well as a novel approach based on proteomic profiles produced by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS). Type or reference strains for each taxonomic group were included in this study. Three isolates that presented discordant identification patterns were further analysed using the internal transcribed spacer (ITS) region and calmodulin gene sequences. The data obtained from the phenotypic and spectral analyses divide the isolates into three groups, corresponding to taxa closely related to Aspergillus flavus, Aspergillus parasiticus, and Aspergillus tamarii. Final polyphasic fungal identification was achieved by joining data from molecular analyses, classical morphology, and biochemical and proteomic profiles generated by MALDI-TOF MS.Acknowledgments are due to FAPEMIG -
Fundacao de Amparo a Pesquisa do Estado de Minas Gerais (Brazil)
for financial support. F. C. da Silva extends thanks to CAPES -
Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (Brazil)
for the PhD grant. C. Santos and N. Lima thank CAPES for the financial
support as international visiting professors in the Post-Graduate Programme
in Agricultural Microbiology, Federal University of Lavras,
Lavras (MG), Brazil
Transtorno autĂstico e doença celĂaca : sem evidĂȘncias de associação
Objective: To evaluate the possible association between celiac disease (CD) and/or gluten sensitivity (GS) and autism spectrum disorder
(ASD). Methods: Occurrences of CD were determined in a group of children and adolescents affected by ASD and, conversely, occurrences
of ASD were assessed in a group of biopsy-proven celiac patients. To detect the possible existence of GS, the levels of antigliadin antibodies in ASD patients were assessed and compared with the levels in a group of non-celiac children. Results: The prevalence of CD or GS in
ASD patients was not greater than in groups originating from the same geographical area. Similarly the prevalence of ASD was not greater
than in a group of biopsy-proven CD patients. Conclusion: No statistically demonstrable association was found between CD or GS and ASD.
Consequently, routine screening for CD or GS in all patients with ASD is, at this moment, neither justifed nor cost-effective. ___________________________________________________________________________________ RESUMOObjetivo: Avaliar a possĂvel associação entre doença celĂaca (DC) e/ou sensibilidade ao glĂșten (SG) e transtorno do espectro autista (TEA).
MĂ©todos: OcorrĂȘncias de DC foram determinadas em um grupo de crianças e adolescentes afetados pelo TEA e a ocorrĂȘncia d TEA foi
avaliada em um grupo de pacientes com DC comprovada por biĂłpsia. Para detectar a possĂvel existĂȘncia de SG, foram determinados nĂveis
de anticorpos antigliadina em pacientes com TEA e comparados ao grupo de crianças sem a doença celĂaca. Resultados: A prevalĂȘncia de
DC ou SG nĂŁo foi maior no grupo de pacientes com TEA quando comparada a grupos de indivĂduos originĂĄrios da mesma regiĂŁo geogrĂĄfca.
De modo similar, a prevalĂȘncia do TEA nĂŁo foi maior ao ser comparada ao grupo de pacientes com DC. ConclusĂŁo: NĂŁo houve associação
estatisticamente demonstråvel entre DC ou SG e TEA. Consequentemente, não são justifcåveis, no momento, exames de rotina para detecção de DC ou SG em pacientes com TEA
Human Multipotent Stromal Cells (MSCs) Increase Neurogenesis and Decrease Atrophy of the Striatum in a Transgenic Mouse Model for Huntington's Disease
Background: Implantation of human multipotent stromal cells from bone marrow (hMSCs) into the dentate gyrus of the hippocampus of mice was previously shown to stimulate proliferation, migration and neural differentiation of endogenous neural stem cells. We hypothesized that hMSCs would be beneficial in a mouse model of Huntington disease (HD) due to these neurogenic effects. Results: We implanted hMSCs into the striatum of transgenic mice (N171-82Q) that are a model for HD. The implanted hMSCs rapidly disappeared over 3 to 15 days. However, they increased proliferation and neural differentiation of endogenous neural stem cells for up to 30 days. They also increased neurotrophic signaling and decreased atrophy of the striatum in 3-month old HD mice implanted with hMSCs one month earlier. Conclusions: The results therefore suggested that neural implantation of hMSCs may be of benefit in HD but a number of parameters of dose, treatment schedule, and route of administration need to be optimized
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