247 research outputs found
: A bioüzemanyagok adózása Magyarországon
MegállapÃtható, hogy a bioetanol adózási helyzete kedvezÅ‘bb, mint a biodÃzelé. Az etanol forgalma dinamikusan növekszik. Magyarországon jelenleg több mint 200 benzinkúton kapható E85 üzemanyag. Annak érdekében, hogy Magyarországon legalább 10% legyen a közlekedési szektorban a „bio†arány, célszerű elsÅ‘ lépésként az üzemanyagokban lévÅ‘ biokomponens-arányt a jelenlegi 4,8%-ról 6,0%-ra, majd 1-2 év múlva 8,0%-ra emelni. A biodÃzelnél, például a B40- ---------------------------------------------- Apparently the status of bioethanol in terms of taxation is more favourable than that of biodiesel. Ethanol sales are growing dynamically. The E85 fuel is currently sold at more than 200 petrol stations in Hungary. In order to increase the share of “bio†to at least 10% in the transportation sector in Hungary it would appear useful to increase the proportion of the bio component found in fuels first to 6.0% from the current 4.8%, then to 8.0% in another one or two years. As for biodiesel, e.g. B40 – biodiesel with 40% ‘bio’ – the ‘bio’ portion could be exempt from tax, limiting taxation to the remaining diesel component (60%) only.bioenergetika, bioüzemanyag, gabona-felhasználás, adózás, bioenergy, biofuels, ethics, using cereals, taxation, Agricultural and Food Policy, Agricultural Finance,
Caustics due to a negative refractive index in circular graphene p-n junctions
We show that the wave functions form caustics in circular graphene
p-n
junctions which in the framework of geometrical optics can be
interpreted with a negative refractive index
Electron Flow in Circular n-p Junctions of Bilayer Graphene
We present a theoretical study of electron wave functions in ballistic
circular n-p junctions of bilayer graphene. Similarly to the case of a circular
n-p junction of monolayer graphene, we find that (i) the wave functions form
caustics inside the circular region, and (ii) the shape of these caustics are
well described by a geometrical optics model using the concept of a negative
refractive index. In contrast to the monolayer case, we show that the strong
focusing effect is absent in the bilayer. We explain these findings in terms of
the angular dependence of Klein tunneling at a planar n-p junction.Comment: Published version 6 pages, 5 figure
A valley-spin qubit in a carbon nanotube
Although electron spins in III-V semiconductor quantum dots have shown great
promise as qubits, a major challenge is the unavoidable hyperfine decoherence
in these materials. In group IV semiconductors, the dominant nuclear species
are spinless, allowing for qubit coherence times that have been extended up to
seconds in diamond and silicon. Carbon nanotubes are a particularly attractive
host material, because the spin-orbit interaction with the valley degree of
freedom allows for electrical manipulation of the qubit. In this work, we
realise such a qubit in a nanotube double quantum dot. The qubit is encoded in
two valley-spin states, with coherent manipulation via electrically driven spin
resonance (EDSR) mediated by a bend in the nanotube. Readout is performed by
measuring the current in Pauli blockade. Arbitrary qubit rotations are
demonstrated, and the coherence time is measured via Hahn echo. Although the
measured decoherence time is only 65 ns in our current device, this work offers
the possibility of creating a qubit for which hyperfine interaction can be
virtually eliminated
FOTONAPONSKI SUSTAVI S OBJE STRANE RIJEKE DRAVE
The aim of present study is to review the introduction of solar energy utilization, the economic determination of the return of crystalline solar systems in Hungary and in Croatia on the two banks of Drava River. The authors have calculated with the electricity price reductions for individuals in Hungary also, which gives more interest to this article. The study was performed with crystalline solar systems and it was carried out in solar-electric power plants extended from 1.5 kWp to 10 kWp. The study included the investment of crystalline solar cell systems. The calculation of payback time was performed by dynamic indices.Cilj je sadašnje studije razmotriti postojeće stanje iskorištenja sunčeve energije i gospodarske razloge za povratak solarnih panela u Mađarskoj i Hrvatskoj na obje obale rijeke Drave. Autori su računali i na smanjenje cijene struje u Mađarskoj za domaćinstva, što povećava interes za ovaj rad. Studija je provedena na energanama sa solarnim panelima, snage od 1.5 - 10 kWp. U istraživanje je uključena vrijednost investicije nabave solarnih sustava. Izračun povrata uloženih sredstava proveden je korištenjem dinamičkih indeksa
Enhanced NMR relaxation of Tomonaga-Luttinger liquids and the magnitude of the carbon hyperfine coupling in single-wall carbon nanotubes
Recent transport measurements [Churchill \textit{et al.} Nat. Phys.
\textbf{5}, 321 (2009)] found a surprisingly large, 2-3 orders of magnitude
larger than usual C hyperfine coupling (HFC) in C enriched
single-wall carbon nanotubes (SWCNTs). We formulate the theory of the nuclear
relaxation time in the framework of the Tomonaga-Luttinger liquid theory to
enable the determination of the HFC from recent data by Ihara \textit{et al.}
[Ihara \textit{et al.} EPL \textbf{90}, 17004 (2010)]. Though we find that
is orders of magnitude enhanced with respect to a Fermi-liquid
behavior, the HFC has its usual, small value. Then, we reexamine the
theoretical description used to extract the HFC from transport experiments and
show that similar features could be obtained with HFC-independent system
parameters.Comment: 5 pages plus 2 supplementary material
Valley-spin blockade and spin resonance in carbon nanotubes
Manipulation and readout of spin qubits in quantum dots made in III-V
materials successfully rely on Pauli blockade that forbids transitions between
spin-triplet and spin-singlet states. Quantum dots in group IV materials have
the advantage of avoiding decoherence from the hyperfine interaction by
purifying them with only zero-spin nuclei. Complications of group IV materials
arise from the valley degeneracies in the electronic bandstructure. These lead
to complicated multiplet states even for two-electron quantum dots thereby
significantly weakening the selection rules for Pauli blockade. Only recently
have spin qubits been realized in silicon devices where the valley degeneracy
is lifted by strain and spatial confinement. In carbon nanotubes Pauli blockade
can be observed by lifting valley degeneracy through disorder. In clean
nanotubes, quantum dots have to be made ultra-small to obtain a large energy
difference between the relevant multiplet states. Here we report on
low-disorder nanotubes and demonstrate Pauli blockade based on both valley and
spin selection rules. We exploit the bandgap of the nanotube to obtain a large
level spacing and thereby a robust blockade. Single-electron spin resonance is
detected using the blockade.Comment: 31 pages including supplementary informatio
Overexpression of specific CD44 isoforms is associated with aggressive cell features in acquired endocrine resistance
While endocrine therapy is the mainstay of ER+ breast cancer, the clinical effectiveness of these agents is limited by the phenomenon of acquired resistance that is associated with disease relapse and poor prognosis. Our previous studies revealed that acquired resistance is accompanied by a gain in cellular invasion and migration and also that CD44 family proteins are overexpressed in the resistant phenotype. Given the association of CD44 with tumor progression, we hypothesized that its overexpression may act to promote the aggressive behavior of endocrine-resistant breast cancers. Here, we have investigated further the role of two specific CD44 isoforms, CD44v3 and CD44v6, in the endocrine-resistant phenotype. Our data revealed that overexpression of CD44v6, but not CD44v3, in endocrine-sensitive MCF-7 cells resulted in a gain in EGFR signaling, enhanced their endogenous invasive capacity, and attenuated their response to endocrine treatment. Suppression of CD44v6 in endocrine-resistant cell models was associated with a reduction in their invasive capacity. Our data suggest that upregulation of CD44v6 in acquired resistant breast cancer may contribute to a gain in the aggressive phenotype of these cells and loss of endocrine response through transactivation of the EGFR pathway. Future therapeutic targeting of CD44v6 may prove to be an effective strategy alongside EGFR-targeted agents in delaying/preventing acquired resistance in breast cancer
Trastuzumab-DM1 causes tumour growth inhibition by mitotic catastrophe in trastuzumab-resistant breast cancer cells in vivo
Introduction
Trastuzumab is widely used for the treatment of HER2-positive breast cancer. Despite encouraging clinical results, a significant fraction of patients are, or become, refractory to the drug. To overcome this, trastuzumab-DM1 (T-DM1), a newer, more potent drug has been introduced. We tested the efficacy and mechanisms of action of T-DM1 in nine HER2-positive breast cancer cell lines in vitro and in vivo. The nine cell lines studied included UACC-893, MDA-453 and JIMT-1, which are resistant to both trastuzumab and lapatinib.
Methods
AlamarBlue cell-proliferation assay was used to determine the growth response of breast cancer cell lines to trastuzumab and T-DM1 in vitro. Trastuzumab- and T-DM1-mediated antibody-dependent cellular cytotoxicity (ADCC) was analysed by measuring the lactate dehydrogenase released from the cancer cells as a result of ADCC activity of peripheral blood mononuclear cells. Severe Combined Immunodeficient (SCID) mice were inoculated with trastuzumab-resistant JIMT-1 cells to investigate the tumour inhibitory effect of T-DM1 in vivo. The xenograft samples were investigated using histology and immunohistochemistry.
Results
T-DM1 was strongly growth inhibitory on all investigated HER2-positive breast cancer cell lines in vitro. T-DM1 also evoked antibody-dependent cellular cytotoxicity (ADCC) similar to that of trastuzumab. Outgrowth of JIMT-1 xenograft tumours in SCID mice was significantly inhibited by T-DM1. Histologically, the cellular response to T-DM1 consisted of apoptosis and mitotic catastrophe, the latter evidenced by an increased number of cells with aberrant mitotic figures and giant multinucleated cells.
Conclusions
Our results suggest mitotic catastrophe as a previously undescribed mechanism of action of T-DM1. T-DM1 was found effective even on breast cancer cell lines with moderate HER2 expression levels and cross-resistance to trastuzumab and lapatinib (MDA-453 and JIMT-1).BioMed Central Open acces
Carbon nanotubes for coherent spintronic devices
Carbon nanotubes bridge the molecular and crystalline quantum worlds, and
their extraordinary electronic, mechanical and optical properties have
attracted enormous attention from a broad scientific community. We review the
basic principles of fabricating spin-electronic devices based on individual,
electrically-gated carbon nanotubes, and present experimental efforts to
understand their electronic and nuclear spin degrees of freedom, which in the
future may enable quantum applications.Comment: 17 pages, 9 figures, submitted to Materials Toda
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