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991.
Przemysław Koźmiński Ewa Gniazdowska Leon Fuks Agata Oszczak 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(1):67-74
Easy and efficient way to modify of the C-terminus of the peptide using amino acid lysine has been proposed and experimentally
verified. The synthesis yield was high (≥85%) and it was found that reactions can be carried out even with microgram amounts
of the peptide. Using Fmoc-alanine (as the peptide model) with modified C-terminus the procedure of peptide labelling with
monovalent and trivalent 99mTc complexes has been elaborated. 相似文献
992.
Ernesta M. Meintjes Sandra W. Jacobson Christopher D. Molteno J. Christopher Gatenby Christopher Warton Christopher J. Cannistraci John C. Gore Joseph L. Jacobson 《Magnetic resonance imaging》2010
By contrast to the adult literature, in which a consistent parietofrontal network for number processing has been identified, the data from studies of number processing in children have been less consistent, probably due to differences in study design and control conditions. Number processing was examined using functional magnetic resonance imaging in 18 right-handed children (8–12 years) from the Cape Coloured community in Cape Town, South Africa, using Proximity Judgment and Exact Addition (EA) tasks. The findings were consistent with the hypothesis that, as in adults, the anterior horizontal intraparietal sulcus (HIPS) plays a major role in the representation and manipulation of quantity in children. The posterior medial frontal cortex, believed to be involved in performance monitoring in more complex arithmetic manipulations in adults, was extensively activated even for relatively simple symbolic number processing in the children. Other areas activated to a greater degree in the children included the left precentral sulcus, which may mediate number knowledge and, for EA, the head of the caudate nucleus, which is part of a fronto-subcortical circuit involved in the behavioral execution of sequences. Two regions that have been linked to number processing in adults — the angular gyrus and posterior superior parietal lobule — were not activated in the children. The data are consistent with the inference that although the functional specialization of the anterior HIPS may increase as symbolic number processing becomes increasingly automatic, this region and other elements of the parietofrontal network identified in adults are already reliably and robustly activated by middle childhood. 相似文献
993.
994.
Vladimir Petukhov John Stoemenos Johan Rothman Andrey Bakin Andreas Waag 《Applied Physics A: Materials Science & Processing》2011,102(1):161-168
In order to interpret results of temperature dependent Hall measurements in heteroepitaxial ZnO-thin films, we adopted a multilayer
conductivity model considering carrier-transport through the interfacial layer with degenerate electron gas as well as the
upper part of ZnO layers with lower conductivity. This model was applied to the temperature dependence of the carrier concentration
and mobility measured by Hall effect in a ZnO-layer grown on c-sapphire with conventional high-temperature MgO and low-temperature
ZnO buffer. We also compared our results with the results of maximum entropy mobility-spectrum analysis (MEMSA). The formation
of the highly conductive interfacial layer was explained by analysis of transmission electron microscopy (TEM) images taken
from similar layers. 相似文献
995.
Carlyle T. B. Menezes Erilson C. Barros Raquel D. Rufino Juliana M. Luna Leonie A. Sarubbo 《Applied biochemistry and biotechnology》2011,163(4):540-546
Dissolved air flotation (DAF) is a well-established separation process employing micro bubbles as a carrier phase. The application
of this technique in the treatment of acid mine drainage, using three yeast biosurfactants as alternative collectors, is hereby
analyzed. Batch studies were carried out in a 50-cm high acrylic column with an external diameter of 2.5 cm. High percentages
(above 94%) of heavy metals Fe(III) and Mn(II) were removed by the biosurfactants isolated from Candida lipolytica and Candida sphaerica and the values were found to be similar to those obtained with the use of the synthetic sodium oleate surfactant. The DAF
operation with both surfactant and biosurfactants, achieved acceptable turbidity values, in accordance with Brazilian standard
limits. The best ones were obtained by the biosurfactant from C. lipolytica, which reached 4.8 NTU. The results obtained with a laboratory synthetic effluent were also satisfactory. The biosurfactants
removed almost the same percentages of iron, while the removal percentages of manganese were slightly higher compared with
those obtained in the acid mine drainage effluent. They showed that the use of low-cost biosurfactants as collectors in the
DAF process is a promising technology for the mining industries. 相似文献
996.
Xiongxin Dai Sheila Kramer-Tremblay 《Journal of Radioanalytical and Nuclear Chemistry》2011,289(2):461-466
Assays of alpha- and beta-emitting radionuclides in swipe samples are often required to monitor the presence of removable
surface contamination for radiological protection and control in nuclear facilities. Swipe analysis has also proven to be
a very sensitive analytical technique to detect nuclear signatures for safeguard verification purposes. A new sequential method
for the determination of actinide isotopes and radiostrontium in swipe samples, which utilizes a streamlined column separation
with stacked anion and extraction chromatography resins, has been developed. To validate the separation procedure, spike and
blank samples were prepared and analyzed by inductively coupled mass spectrometry (ICP-MS), alpha spectrometry and liquid
scintillation (LS) counting. Low detection limits have been achieved for isotopic analysis of Pu (238Pu, 239Pu, 240Pu, 241Pu), U (234U, 235U, 238U), Am (241Am), Cm (242Cm, 243/244Cm) and Sr (90Sr) at ultra-trace concentration levels in swipe samples. 相似文献
997.
James Casey 《Meccanica》2011,46(2):471-476
For motion of a material point along a space curve, a kinematical decomposition, discovered by Siacci, expresses the acceleration
vector as the sum of two special oblique components in the osculating plane to the curve. A new proof of Siacci’s theorem
is presented. 相似文献
998.
Fluorescence correlation spectroscopy (FCS) of colloidal nanoparticles using a near-field fiber probe was numerically simulated.
The near-wall dynamics was simulated by accounting for the anisotropic mobility of nanoparticles owing to hydrodynamic interaction
with a wall (Stokes viscous force). By comparing the simulation results with theoretical model calculations, we found that
the influence of anisotropic diffusion is insignificant in near-field FCS autocorrelation analysis. 相似文献
999.
J. Klusoň Kamal L. Panigrahi 《The European Physical Journal C - Particles and Fields》2011,71(3):1595
We continue our study of the Lorentz-breaking string theories. These theories are defined as string theory with modified Hamiltonian
constraint which breaks the Lorentz symmetry of target space-time. We analyze the properties of this theory in the target
space-time that possesses isometry along one direction. We also derive the T-duality rules for Lorentz-breaking string theories
and show that they are the same as that of Buscher’s T-duality for the relativistic strings. 相似文献
1000.
An-Wei Li 《Nonlinear dynamics》2011,66(4):689-694
In this paper, we investigated the influence of color noise on pattern formation in a predator–prey model. When the model
has no noise, it exhibits wave dynamics. A series of numerical simulations showed that break-up of waves will emerge when
noise is added. Furthermore, stationary pattern can be induced by noise. The obtained results may point out that noise can
have great effect on spatial complexity of ecosystems. 相似文献