7,685 research outputs found
Universal properties of the U(1) current at deconfined quantum critical points: comparison with predictions from gauge/gravity duality
The deconfined quantum critical point of a two-dimensional SU(N)
antiferromagnet is governed by an Abelian Higgs model in spacetime
dimensions featuring complex scalar fields. In this context, we derive for
an exact formula for the central charge of the U(1) current in
terms of the gauge coupling at quantum criticality and compare it with the
corresponding result obtained using gauge-gravity duality. There is a
remarkable similarity precisely for . In this case the amplitude of the
current correlation function has the same form as predicted by the
gauge-gravity duality. We also compare finite temperature results for the
charge susceptibility in the large limit with the result predicted by the
gauge-gravity duality. Our results suggest that condensed matter systems at
quantum criticality may provide interesting quantitative tests of the
gauge-gravity duality even in absence of supersymmetry.Comment: 4.5 pages, 1 figure; v2: accepted in PRD, text restructured to make
presentation/discussion clearer, references adde
Use of dialkyldithiocarbamato complexes of bismuth(III) for the preparation of nano- and microsized Bi2S3 particles and the X-ray crystal structures of [Bi{S2CN(CH3)(C6H13)}(3)] and [Bi{S2CN(CH3)(C6H13)}(3)(C12H8N2)]
A range of bismuth(III) dithiocarbamato complexes were prepared and characterized. The
X-ray crystal structures of the compounds [Bi{S2CN(CH3)(C6H13)}3] (1) and [Bi{S2CN(CH3)-
(C6H13)}3(C12H8N2)] (2) are reported. The preparation of Bi2S3 particulates using a wet
chemical method and involving the thermalysis of Bi(III) dialkyldithiocarbamato complexes
is described. The influence of several experimental parameters on the optical and
morphological properties of the Bi2S3 powders was investigated. Nanosized Bi2S3 colloids
were obtained having long-term stability and showing a blue shift on the optical band edge;
the presence of particles exhibiting quantum size effects is discussed. Morphological welldefined Bi2S3 particles were obtained in which the fiber-type morphology is prevalent.FCT - POCTI/1999/CTM/ 3545
Site-selective protein modification via disulfide rebridging for fast tetrazine/trans-cyclooctene bioconjugation
An inverse electron demand Diels–Alder reaction between tetrazine and trans-cyclooctene (TCO) holds great promise for protein modification and manipulation. Herein, we report the design and synthesis of a tetrazine-based disulfide rebridging reagent, which allows the site-selective installation of a tetrazine group into disulfide-containing peptides and proteins such as the hormone somatostatin (SST) and the antigen binding fragment (Fab) of human immunoglobulin G (IgG). The fast and efficient conjugation of the tetrazine modified proteins with three different TCO-containing substrates to form a set of bioconjugates in a site-selective manner was successfully demonstrated for the first time. Homogeneous, well-defined bioconjugates were obtained underlining the great potential of our method for fast bioconjugation in emerging protein therapeutics. The formed bioconjugates were stable against glutathione and in serum, and they maintained their secondary structure. With this work, we broaden the scope of tetrazine chemistry for site-selective protein modification to prepare well-defined SST and Fab conjugates with preserved structures and good stability under biologically relevant conditions
Fabricação de filmes nanoestruturados baseados em nanocompósito/ polímero condutor para aplicação em sensores do tipo língua eletrônica.
The Portuguese-speaking community in Lambeth: a scoping study
This report presents the findings from research with the Portuguese-speaking community in Lambeth commissioned by the London Community Foundation. It is designed to inform the work of the Lambeth Community Fund Grant Committee which makes decisions regarding the distribution the Portuguese Speakers Community Fund. Based mainly on semi-structured, face to face interviews with community representatives and local service providers, it provides a snapshot of the Portuguese-speaking community in Lambeth, its make-up, needs and support structure
Quantum criticality of U(1) gauge theories with fermionic and bosonic matter in two spatial dimensions
We consider relativistic U(1) gauge theories in 2+1 dimensions, with N_b
species of complex bosons and N_f species of Dirac fermions at finite
temperature. The quantum phase transition between the Higgs and Coulomb phases
is described by a conformal field theory (CFT). At large N_b and N_f, but for
arbitrary values of the ratio N_b/N_f, we present computations of various
critical exponents and universal amplitudes for these CFTs. We make contact
with the different spin-liquids, charge-liquids and deconfined critical points
of quantum magnets that these field theories describe. We compute physical
observables that may be measured in experiments or numerical simulations of
insulating and doped quantum magnets.Comment: 30 pages, 8 figure
Sendrá el tenor de sólidos solubles totales de los frutos de cucumis melo influenciado por carlavirus?
Melão; Cucumis melo; Insetos; Mosca-Branca; Bemisia tabaci; Teor de sólido
Draft genome sequence of Agrobacterium deltaense strain CNPSo 3391, isolated from a soybean nodule in Mozambique
Open Access Article; Published online: 7 March 2019Agrobacterium deltaense strain CNPSo 3391 was isolated from a soybean nodule in Mozambique. Its genome size was estimated at 4,926,588 bp. This isolate carries several coding sequences for stress tolerance, but no identifiable nodulation or virulence genes. Possible ecological roles of bacteria isolated from legume nodules and closely related to Agrobacterium are discussed
Soybean seed co-inoculation with Bradyrhizobium spp. and Azospirillum brasilense: a new biotechnological tool to improve yield and sustainability.
Legume nodulation by rhizobia can supply crops with nitrogen and reduce environmental impacts caused by chemical fertilization. The soybean crop in Brazil is an impressive example of how biological N2 fixation can be employed with a plant species of high economic value. However, the development of more productive cultivars, along with the increasing global climatic changes demand agricultural practices to become more productive and yet more environmentally friendly. Plant growth-promoting rhizobacteria (PGPR) are highly beneficial to agriculture worldwide, acting in plant nutrition, protection, and growth stimulation. Azospirillum is, certainly, the most employed PGPR in the world, but little is known about its interaction with rhizobia, when both are applied to legume seeds. We have evaluated the co-inoculation of bradyrhizobia and azospirilla on soybean seeds under different soil and climate conditions in Brazil. Our results demonstrated that co-inoculation is efficient and beneficial to the crop, and promotes yield increases without adding any chemical N fertilizers even in soils where established populations of soybean bradyrhizobia exist. The strategy of co-inoculation thus represents a new biotechnological tool to improve soybean yield without adding any chemical N fertilizers, thus contributing to current practices of sustainability in agriculture
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