119 research outputs found
КИНЕТИЧЕСКИЕ МОДЕЛИ СИНТЕЗА ФИШЕРА-ТРОПША В ПРИСУТСТВИИ КАТАЛИЗАТОРОВ С НАНОЧАСТИЦАМИ ЖЕЛЕЗА НА ПОЛИМЕРНЫХ МАТРИЦАХ В СЛАРРИ-РЕАКТОРЕ
Influence of additives of synthetic polymers of various natures on reactionary ability of the nanostructured iron catalysts in the three-component Fe-paraffin-polymer system in Fischer-Tropsch (FTS) in the slurry reactor was studied. The polymers used: polyacrylonitrile (PAN), polyvinyl alcohol (PVA), polystyrene, cross-linked with divinylbenzene (PS-DVB), polyamide-6 (PA). The catalysts obtained by droplet thermolysis is influenced by, the nature of the stabilizing polymer. Besides the conversion of the synthesis gas depends on the contact time and is between 10 to 80%. The highest rate of FTS is observed in the Fe-paraffin-PAN. The conditions of synthesis in Fe-paraffin-polymer systems produced a wide range of saturated and unsaturated compounds. It is found that the nature of the stabilizing polymer also affects the olefin /paraffin ratio. Based on experimental data the analysis of kinetic models for the flow of CO is carried out, a kinetic and thermodynamic characteristics of the process was obtained. The relationship between the values of the activation energies and the nature of the stabilizer was established.Исследовано влияние добавок синтетических полимеров различной природы на реакционную способность наноструктурированных железных катализаторов в трехкомпонентной системе Fe-парафин-полимер в синтезах Фишера-Тропша (FTS) в сларри-реакторе. В качестве полимеров использовали: полиакрилонитрил (ПАН), поливиниловый спирт (ПВС), полистирол, сшитый с дивинилбензолом (ПС-ДВБ), полиамид 6 (ПА). На реакционную способность катализаторов, полученных методом капельного термолиза, влияет природа стабилизирующего полимера. Помимо этого, конверсия синтез-газа зависит от времени контакта и составляет от 10 до 80%. Наибольшая скорость FTS наблюдается в системе Fe-парафин-ПАН. В условиях синтеза в системах Fe-парафин-полимер образуется широкий спектр предельных и непредельных соединений. Установлено, что природа стабилизирующего полимера влияет также на соотношение олефин/парафин. На основании экспериментальных данных проведен анализ кинетических моделей для расхода СО, получены кинетические и термодинамические характеристики процесса. Установлена связь между значениями энергий активации и природой стабилизатора
Linking microarray reporters with protein functions
<p>Abstract</p> <p>Background</p> <p>The analysis of microarray experiments requires accurate and up-to-date functional annotation of the microarray reporters to optimize the interpretation of the biological processes involved. Pathway visualization tools are used to connect gene expression data with existing biological pathways by using specific database identifiers that link reporters with elements in the pathways.</p> <p>Results</p> <p>This paper proposes a novel method that aims to improve microarray reporter annotation by BLASTing the original reporter sequences against a species-specific EMBL subset, that was derived from and crosslinked back to the highly curated UniProt database. The resulting alignments were filtered using high quality alignment criteria and further compared with the outcome of a more traditional approach, where reporter sequences were BLASTed against EnsEMBL followed by locating the corresponding protein (UniProt) entry for the high quality hits. Combining the results of both methods resulted in successful annotation of > 58% of all reporter sequences with UniProt IDs on two commercial array platforms, increasing the amount of Incyte reporters that could be coupled to Gene Ontology terms from 32.7% to 58.3% and to a local GenMAPP pathway from 9.6% to 16.7%. For Agilent, 35.3% of the total reporters are now linked towards GO nodes and 7.1% on local pathways.</p> <p>Conclusion</p> <p>Our methods increased the annotation quality of microarray reporter sequences and allowed us to visualize more reporters using pathway visualization tools. Even in cases where the original reporter annotation showed the correct description the new identifiers often allowed improved pathway and Gene Ontology linking. These methods are freely available at http://www.bigcat.unimaas.nl/public/publications/Gaj_Annotation/.</p
Assignment of genetic linkage maps to diploid Solanum tuberosum pachytene chromosomes by BAC-FISH technology
A cytogenetic map has been developed for diploid potato (Solanum tuberosum), in which the arms of the 12 potato bivalents can be identified in pachytene complements using multicolor fluorescence in situ hybridization (FISH) with a set of 60 genetically anchored bacterial artificial chromosome (BAC) clones from the RHPOTKEY BAC library. This diagnostic set of selected BACs (five per chromosome) hybridizes to euchromatic regions and corresponds to well-defined loci in the ultradense genetic map, and with these probes a new detailed and reliable pachytene karyotype could be established. Chromosome size has been estimated both from microscopic length measurements and from 4′,6-diamidino-2-phenylindole fluorescence-based DNA content measurements. In both approaches, chromosome 1 is the largest (100–115 Mb) and chromosome 11 the smallest (49–53 Mb). Detailed measurements of mega-base-pair to micrometer ratios have been obtained for chromosome 5, with average values of 1.07 Mb/μm for euchromatin and 3.67 Mb/μm for heterochromatin. In addition, our FISH results helped to solve two discrepancies in the potato genetic map related to chromosomes 8 and 12. Finally, we discuss the significance of the potato cytogenetic map for extended FISH studies in potato and related Solanaceae, which will be especially beneficial for the potato genome-sequencing project
Test of lepton universality in decays
The first simultaneous test of muon-electron universality using
and decays is performed, in two ranges of the dilepton
invariant-mass squared, . The analysis uses beauty mesons produced in
proton-proton collisions collected with the LHCb detector between 2011 and
2018, corresponding to an integrated luminosity of 9 . Each
of the four lepton universality measurements reported is either the first in
the given interval or supersedes previous LHCb measurements. The
results are compatible with the predictions of the Standard Model.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-046.html (LHCb
public pages
Precision measurement of violation in the penguin-mediated decay
A flavor-tagged time-dependent angular analysis of the decay
is performed using collision data collected
by the LHCb experiment at % at TeV, the center-of-mass energy of
13 TeV, corresponding to an integrated luminosity of 6 fb^{-1}. The
-violating phase and direct -violation parameter are measured
to be rad and
, respectively, assuming the same values
for all polarization states of the system. In these results, the
first uncertainties are statistical and the second systematic. These parameters
are also determined separately for each polarization state, showing no evidence
for polarization dependence. The results are combined with previous LHCb
measurements using collisions at center-of-mass energies of 7 and 8 TeV,
yielding rad and . This is the most precise study of time-dependent violation
in a penguin-dominated meson decay. The results are consistent with
symmetry and with the Standard Model predictions.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-001.html (LHCb
public pages
Measurement of the differential branching fraction
The branching fraction of the rare decay is measured for the first time, in the squared dimuon mass
intervals, , excluding the and regions. The data
sample analyzed was collected by the LHCb experiment at center-of-mass energies
of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of $9\
\mathrm{fb}^{-1}q^{2}q^{2} >15.0\
\mathrm{GeV}^2/c^4$, where theoretical predictions have the smallest model
dependence, agrees with the predictions.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-050.html (LHCb
public pages
Precision measurement of CP violation in the penguin-mediated decay Bs0→ϕϕ
A flavor-tagged time-dependent angular analysis of the decay
B
0
s
→
ϕ
ϕ
is performed using
p
p
collision data collected by the LHCb experiment at the center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of
6
fb
−
1
. The
C
P
-violating phase and direct
C
P
-violation parameter are measured to be
ϕ
s
¯
s
s
s
=
−
0.042
±
0.075
±
0.009
rad
and
|
λ
|
=
1.004
±
0.030
±
0.009
, respectively, assuming the same values for all polarization states of the
ϕ
ϕ
system. In these results, the first uncertainties are statistical and the second systematic. These parameters are also determined separately for each polarization state, showing no evidence for polarization dependence. The results are combined with previous LHCb measurements using
p
p
collisions at center-of-mass energies of 7 and 8 TeV, yielding
ϕ
s
¯
s
s
s
=
−
0.074
±
0.069
rad
and
|
λ
|
=
1.009
±
0.030
. This is the most precise study of time-dependent
C
P
violation in a penguin-dominated
B
meson decay. The results are consistent with
C
P
symmetry and with the standard model predictions
Measurement of the ratios of branching fractions R(D*) and R(D0)
The ratios of branching fractions
R
(
D
∗
)
≡
B
(
¯
B
→
D
∗
τ
−
¯
ν
τ
)
/
B
(
¯
B
→
D
∗
μ
−
¯
ν
μ
)
and
R
(
D
0
)
≡
B
(
B
−
→
D
0
τ
−
¯
ν
τ
)
/
B
(
B
−
→
D
0
μ
−
¯
ν
μ
)
are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to
3.0
fb
−
1
of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode
τ
−
→
μ
−
ν
τ
¯
ν
μ
. The measured values are
R
(
D
∗
)
=
0.281
±
0.018
±
0.024
and
R
(
D
0
)
=
0.441
±
0.060
±
0.066
, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is
ρ
=
−
0.43
. The results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the standard model
Test of lepton universality in b→sℓ+ℓ− decays
The first simultaneous test of muon-electron universality using
B
+
→
K
+
ℓ
+
ℓ
−
and
B
0
→
K
*
0
ℓ
+
ℓ
−
decays is performed, in two ranges of the dilepton invariant-mass squared,
q
2
. The analysis uses beauty mesons produced in proton-proton collisions collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of
9
fb
−
1
. Each of the four lepton universality measurements reported is either the first in the given
q
2
interval or supersedes previous LHCb measurements. The results are compatible with the predictions of the Standard Model
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