1,781 research outputs found
Molecular Structures of the Metastable Charge-Transfer Complexes of Benzene (and Toluene) With Bromine as the Pre-Reactive Intermediates in Electrophilic Aromatic Bromination
Successful crystallization and X-ray crystallographic analyses of the highly metastable (1∶1) complexes of bromine with benzene and toluene establish the unique (localized) structure B that differs in notable ways from the long-accepted (delocalized) structure A. Furthermore, we demonstrate the (highly structured) charge-transfer complexes [C6H6,Br2] and [CH3C6H5,Br2] to be the pre-reactive intermediates that are converted (via an overall Br+ transfer) to the Wheland intermediates in electrophilic aromatic bromination. The role of the dative ion pairs [C6H6˙+ Br2˙−] and [CH3C6H5˙+ Br2˙−] in the rate-limiting activation processes is underscored
Noncovalent Binding of the Halogens to Aromatic Donors. Discrete Structures of Labile Br\u3csub\u3e2\u3c/sub\u3e Complexes with Benzene and Toluene
Precise molecular structures resulting from the noncovalent interaction of Br2 with benzene (and toluene) reveal the unusual localized bonding to specific (one or two) carbon centers in prereactive complexes leading directly to the transition states for electrophilic aromatic brominations
Lateral transport of thermal capillary waves
We demonstrate that collective motion of interfacial fluctuations can occur
at the interface between two coexisting thermodynamic phases. Based on computer
simulation results for driven diffusive Ising and Blume-Capel models, we
conjecture that the thermal capillary waves at a planar interface travel along
the interface if the lateral order parameter current j_op(y) is an odd function
of the distance y from the interface and hence possesses opposite directions in
the two phases. Such motion does not occur if j_op(y) is an even function of y.
A discrete Gaussian interface model with effective dynamics exhibits similiar
transport phenomena but with a simpler dispersion relation. These findings open
up avenues for controlled interfacial transport on the nanoscale.Comment: 4 pages, 6 figure
Quantum Noise for Faraday Light Matter Interfaces
In light matter interfaces based on the Faraday effect quite a number of quantum information protocols have been successfully demonstrated. In order to further increase the performance and fidelities achieved in these protocols a deeper understanding of the relevant noise and decoherence processes needs to be gained. In this article we provide for the first time a complete description of the decoherence from spontaneous emission. We derive from first principles the effects of photons being spontaneously emitted into unobserved modes. Our results relate the resulting decay and noise terms in effective equations of motion for collective atomic spins and the forward propagating light modes to the full atomic level structure. We illustrate and apply our results to the case of a quantum memory protocol. Our results can be applied to any suitable atomic species, and the general approach taken in this article can be applied to light matter interfaces and quantum memories based on different mechanisms
On right conjugacy closed loops of twice prime order
The right conjugacy closed loops of order 2p, where p is an odd prime, are
classified up to isomorphism.Comment: Clarified definitions, added some remarks and a tabl
The effect of humic acids on the natural resistance of the body of broiler chickens and the quality of their meat
ArticleThe aim of the work is to study the effectiveness of the concentration of humic acids
of Reasil Humic Vet feed additive on the increase of the feed bioavailability for poultry and the
probability of its negative impact on the safety and marketable characteristics of the final product.
Studies were conducted on the basis of the Saratov State Agrarian University in two similar
groups of broiler chickens ‘Cobb 500’, 100 heads each. Poultry feeding consisted of the same
complete feed, but the drinking water for the broilers of the experimental group was enriched by
humates in the amount of 0.5 ml L
-1
. Based on the data obtained by daily weighing of the poultry
and considering the feed intake, a positive trend of the influence of the feed additive on the
average daily weight gain and feed conversion per unit of production was noted. The results of
slaughter and anatomical cutting of broiler carcasses revealed that metabolic processes were more
active in the body of an experimental poultry, reflected in the intensive growth of muscle tissue
and fat deposition, which contributed to an increase in the yield of edible parts from carcasses by
9.9%. Studies of composition of broiler blood indicate non-toxicity of the recommended
concentration of humates in the feed additive, its stimulation of non-specific resistance of the
organism, contributing to the functioning of the immune system and the development of internal
organs and, as a consequence, ensuring the safety of the products obtained from them
Ballistic deposition patterns beneath a growing KPZ interface
We consider a (1+1)-dimensional ballistic deposition process with
next-nearest neighbor interaction, which belongs to the KPZ universality class,
and introduce for this discrete model a variational formulation similar to that
for the randomly forced continuous Burgers equation. This allows to identify
the characteristic structures in the bulk of a growing aggregate ("clusters"
and "crevices") with minimizers and shocks in the Burgers turbulence, and to
introduce a new kind of equipped Airy process for ballistic growth. We dub it
the "hairy Airy process" and investigate its statistics numerically. We also
identify scaling laws that characterize the ballistic deposition patterns in
the bulk: the law of "thinning" of the forest of clusters with increasing
height, the law of transversal fluctuations of cluster boundaries, and the size
distribution of clusters. The corresponding critical exponents are determined
exactly based on the analogy with the Burgers turbulence and simple scaling
considerations.Comment: 10 pages, 5 figures. Minor edits: typo corrected, added explanation
of two acronyms. The text is essentially equivalent to version
Enhanced CD8+ T-cell response in mice immunized with NS1-truncated influenza virus
Influenza viruses with truncated NS1 protein stimulate a more intensive innate immune response compared to their wild type counterparts. Here, we investigate how the shortening of the NS1 protein influence the immunogenicity of the conserved T-cellular epitopes of influenza virus. Using flow cytometry, we showed that the intraperitoneal immunization of mice with influenza virus encoding 124 N-terminal amino acid residues of the NS1 protein (A/PR8/NS124) induced higher levels of CD8+ T-cells recognizing immunodominant (NP366-374) and sub-immunodominant (NP161-175, NP196-210, HA323-337, HA474-483, NA427-433) epitopes compared to immunization with the virus expressing full-length NS1 (A/PR8/full NS). It is noteworthy that the response to the immunodominant influenza epitope NP366-374 was achieved with the lower immunization dose of A/PR8/NS124 virus compared to the reference wild type strain. Despite the fact that polyfunctional CD8+ effector memory T-lymphocytes simultaneously producing two (IFNγ and TNFα) or three (IFNγ, IL2, and TNFα) cytokines prevailed in the immune response to both viruses, the relative number of such T-cells was higher in A/PR8/NS124-immunized mice. Furthermore, we have found that polyfunctional populations of lymphocytes generated upon the immunization of mice with the mutant virus demonstrated an increased capacity to produce IFNγ compared to the corresponding populations derived from the A/PR8/full NS-immunized mice. Therefore, immunization with the attenuated influenza virus encoding truncated NS1 protein ensures a more potent CD8+ T-cell immune response.Influenza viruses with truncated NS1 protein stimulate a more intensive innate immune response compared to their wild type counterparts. Here, we investigate how the shortening of the NS1 protein influence the immunogenicity of the conserved T-cellular epitopes of influenza virus. Using flow cytometry, we showed that the intraperitoneal immunization of mice with influenza virus encoding 124 N-terminal amino acid residues of the NS1 protein (A/PR8/NS124) induced higher levels of CD8+ T-cells recognizing immunodominant (NP366-374) and sub-immunodominant (NP161-175, NP196-210, HA323-337, HA474-483, NA427-433) epitopes compared to immunization with the virus expressing full-length NS1 (A/PR8/full NS). It is noteworthy that the response to the immunodominant influenza epitope NP366-374 was achieved with the lower immunization dose of A/PR8/NS124 virus compared to the reference wild type strain. Despite the fact that polyfunctional CD8+ effector memory T-lymphocytes simultaneously producing two (IFNγ and TNFα) or three (IFNγ, IL2, and TNFα) cytokines prevailed in the immune response to both viruses, the relative number of such T-cells was higher in A/PR8/NS124-immunized mice. Furthermore, we have found that polyfunctional populations of lymphocytes generated upon the immunization of mice with the mutant virus demonstrated an increased capacity to produce IFNγ compared to the corresponding populations derived from the A/PR8/full NS-immunized mice. Therefore, immunization with the attenuated influenza virus encoding truncated NS1 protein ensures a more potent CD8+ T-cell immune response
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