1,143 research outputs found
Boradiazaindacene (Bodipy)-based building blocks for the construction of energy transfer cassettes
Cataloged from PDF version of article.Energy transfer cassettes composed entirely of boradiazaindacene (Bodipy) units were designed and synthesized to capture photonic energy and convert it to longer wavelength fluorescence emission. The new energy transfer systems obtained by simple condensation reactions are capable of elaborating efficient energy transfer from donor Bodipy units to the distyryl-Bodipy acceptor. (C) 2009 Elsevier Ltd. All rights reserved
P04-17. The N-glycosylation sites N295, N332 and N392 of gp120 are necessary but not sufficient for HIV-1 to be neutralized by 2G12
International audiencen.
The role of microbial activity on iron uptake of wheat genotypes different in fe-efficiency
Soils in many agricultural areas have high pH, resulting in low availability of Fe. Wheat grown on such soils suffers
from most micronutrient deficiencies, in particular Fe deficiency. The objective of this investigation was to determine
the potentials of indigenous fluorescent Pseudomondas for siderophore production and their effects on 59Fe
acquisition. For this purpose, some strains of Pseudomonas putida, Pseudomonas fluorescens, and Pseudomonas
aeruginosa were isolated from different locations representing rhizosphere of wheat. The potentials of these strains
for siderophore production were evaluated by chrome azorel-S assay (CAS blue agar) through color change. High
siderophore producing Super-strains were selected for extraction of siderophores. These isolates were grown in SSM
(standard succinate medium) for 72 hr at 28 C. Bacterial cell were removed by centrifugation (10000 g for 20 min)
and the supernatant was filtered through filter membrane (0.22 ) and used as crowd siderophore. Evaluation of Fe
uptake and translocation were carried out with complexes of bacterial siderophores and 59Fe compared with standard
sierophore Desferrioxamine (DFOB) in randomized complete block design with three replications. This experiment
was conducted on two wheat genotypes different in Fe-efficiency at hydroponic condition. The results showed that
among the three most effective siderophores producing strains considered, the P. putida produced a sidrophore
complex that showed efficiencies of 76 %, compared with the standard siderophore (DFOB) in the uptake of Fe and
was statistically in the same group as the control. The effect of bacterial siderophores in the uptake of labeled 59Fe by
wheat became significant, indicating that the chemical structure of the siderophores from different strains were
different. The effects of wheat genotype in 59Fe activity of shoots was also significant, where the efficient Tabasi
genotype contained 46 % more Fe in shoots than the inefficient Yavarous genotype. It was concluded that the
siderophore complex from P. putida was the most effective in translocating Fe to shoots, particularly in efficient
Tabasi genotype. Siderophore effectiveness in Fe availability decreased in the order;
Sid-DFOB> Sid-putida>Sid-fluorescens> Sid-areuginosa
The effects of twisted magnetic field on coronal loops oscillations and dissipation
The standing MHD modes in a zero- cylindrical magnetic flux tube
modelled as a straight core surrounded by a magnetically twisted annulus, both
embedded in a straight ambient external field is considered. The dispersion
relation for the fast MHD waves is derived and solved numerically to obtain the
frequencies of both the kink (), and fluting () waves. Damping
rates due to both viscous and resistive dissipations in presence of the twisted
magnetic field is derived and solved numerically for both the kink and fluting
waves.Comment: 13 pages, 11 figure
Is higher education more important for firms than research? Disentangling university spillovers
The paper is the first attempt to integrate microdata on universities and firms across most European countries in order to disentangle the impact of knowledge spillovers from human capital (graduates) and intellectual capital (codified research output) on the performance of firms. Data cover all Higher Education Institutions (HEIs) registered in the official European Tertiary Education Register (ETER). Data on performance of firms are from ORBIS and refer to change in the 2011â2015 period in turnover, total assets, intangible assets, and employment. Firms are georeferred and the spillovers from all HEIs located at a given distance are summed and integrated. The findings suggest that, among knowledge spillovers, the creation of human capital via education of students has a larger impact than the circulation of research knowledge. Moreover, the two factors seem to be complements rather than substitutes. Spatial proximity is important for embodied knowledge spillovers (i.e. educated people), while for codified and disembodied spillovers (citations to publications) the spatial dimension is less relevant. The findings have important managerial and policy-making consequences
High-fidelity simulations of CdTe vapor deposition from a new bond-order potential-based molecular dynamics method
CdTe has been a special semiconductor for constructing the lowest-cost solar
cells and the CdTe-based Cd1-xZnxTe alloy has been the leading semiconductor
for radiation detection applications. The performance currently achieved for
the materials, however, is still far below the theoretical expectations. This
is because the property-limiting nanoscale defects that are easily formed
during the growth of CdTe crystals are difficult to explore in experiments.
Here we demonstrate the capability of a bond order potential-based molecular
dynamics method for predicting the crystalline growth of CdTe films during
vapor deposition simulations. Such a method may begin to enable defects
generated during vapor deposition of CdTe crystals to be accurately explored
The effect of PGPR inoculation on the growth of wheat
Many agricultural soils of Iran have high pH, resulting in low availability of Fe and Zn. The potentials of nonsymbiotic
plant growth-promoting rhizbacteria (PGPR) for stimulating plant growth have been extensively used
during recent decades. This experiment was carried out in growth chamber to evaluate the effects of siderophoreproducing
Pseudomonads on the growth as well as Fe and Zn uptake of wheat. A randomized complete block
design experiments was conducted using with Alborz genotype (an efficient phytosiderophore-producing bread
wheat) treated with either 7NSK2 strain as a siderophore positive (sid+) or with MPFM1 mutant strain of the same
isolate as a siderophore negative (sid-) treatments with three replications. The potentials of these strains for auxin
production and phosphate solubilizing activity were evaluated by standard methods. The results showed that
inoculation with sid+ strain increased dry matter production in shoots as compared with the control (sterile
condition) or with sid - strain. Likewise, the concentration of chlorophyll a in leaves of sid+ and sid - treatments were
1.27 and 0.41 g mg-1 of fresh weight, respectively, and the concentration of chlorophyll b were measured to be 1.09
and 0.35 g mg-1 of fresh weight, respectively, indicating significantly more chlorophyll formation due to inoculation
with sid+ as compared with sid -. The uptake of Fe by roots and its rate of translocation to the shoots were greater
for the sid+ treated plants as compared with the sid - treated ones, indicating that siderophores increased the rate
of Fe uptake by wheat. The effect of microbial inoculation on shoot Zn was not significant, but increased the
concentration of Zn on roots compared with control. The results suggested that the siderophores of Pseudomonads
may involve on increasing bioavailability of iron
Mechanically Stabilized Tetrathiafulvalene Radical Dimers
Two donorâacceptor [3]catenanesâcomposed of a tetracationic molecular square, cyclobis(paraquat-4,4âČ-biphenylene), as the Ï-electron deficient ring and either two tetrathiafulvalene (TTF) and 1,5-dioxynaphthalene (DNP) containing macrocycles or two TTF-butadiyne-containing macrocycles as the Ï-electron rich componentsâhave been investigated in order to study their ability to form TTF radical dimers. It has been proven that the mechanically interlocked nature of the [3]catenanes facilitates the formation of the TTF radical dimers under redox control, allowing an investigation to be performed on these intermolecular interactions in a so-called âmolecular flaskâ under ambient conditions in considerable detail. In addition, it has also been shown that the stability of the TTF radical-cation dimers can be tuned by varying the secondary binding motifs in the [3]catenanes. By replacing the DNP station with a butadiyne group, the distribution of the TTF radical-cation dimer can be changed from 60% to 100%. These findings have been established by several techniques including cyclic voltammetry, spectroelectrochemistry and UVâvisâNIR and EPR spectroscopies, as well as with X-ray diffraction analysis which has provided a range of solid-state crystal structures. The experimental data are also supported by high-level DFT calculations. The results contribute significantly to our fundamental understanding of the interactions within the TTF radical dimers
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