459,477 research outputs found
CHO-S master cell line generation.
No full text(A) The H11 locus was cleaved, using CRISPR/Cas9, to encourage integration of the landing pad donor. A successful knock-in at the H11 locus generates a master cell line that has two PhiC31 attP sites, and that co-expresses three proteins via a PGK promoter-driven transcript. (B) Genotyping of the 5’-arm and 3’-arm in the CHO-S master cell line. PCR was performed with genomic DNA and specific primer pairs. 1: CHO-S parental cell line with 5’-arm primers; 2: CHO-S master cell line ("4–6") with 5’-arm primers; 3: CHO-S parental cell line with 3’-arm primers; 4: CHO-S master cell line ("4–6") with 3’-arm primers.</p
CHO microRNA engineering is growing up : recent successes and future challenges
No full textmicroRNAs with their ability to regulate complex pathways that control cellular behavior and phenotype have been proposed as potential targets for cell engineering in the context of optimization of biopharmaceutical production cell lines, specifically of Chinese Hamster Ovary cells. However, until recently, research was limited by a lack of genomic sequence information on this industrially important cell line. With the publication of the genomic sequence and other relevant data sets for CHO cells since 2011, the doors have been opened for an improved understanding of CHO cell physiology and for the development of the necessary tools for novel engineering strategies. In the present review we discuss both knowledge on the regulatory mechanisms of microRNAs obtained from other biological models and proof of concepts already performed on CHO cells, thus providing an outlook of potential applications of microRNA engineering in production cell lines
Branching fraction and CP asymmetry of the decays B+→K0Sπ+ and B+→K0SK+
No full textAn analysis of B+ → K0
Sπ+ and B+ → K0
S K+ decays is performed with the LHCb experiment. The pp
collision data used correspond to integrated luminosities of 1 fb−1 and 2 fb−1 collected at centre-ofmass
energies of
√
s = 7 TeV and
√
s = 8 TeV, respectively. The ratio of branching fractions and the
direct CP asymmetries are measured to be B(B+ → K0
S K+
)/B(B+ → K0
Sπ+
) = 0.064 ± 0.009 (stat.) ±
0.004 (syst.), ACP(B+ → K0
Sπ+
) = −0.022 ± 0.025 (stat.) ± 0.010 (syst.) and ACP(B+ → K0
S K+
) =
−0.21 ± 0.14 (stat.) ± 0.01 (syst.). The data sample taken at
√
s = 7 TeV is used to search for
B+
c
→ K0
S K+ decays and results in the upper limit ( fc · B(B+
c
→ K0
S K+
))/( fu · B(B+ → K0
Sπ+
)) <
5.8 × 10−2 at 90% confidence level, where fc and fu denote the hadronisation fractions of a ¯b
quark
into a B+
c or a B+ meson, respectively
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
No full textThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
Observations of Bºs→ψ(2S)η and Bº(s)→ψ(2S)π+π- decays
No full textFirst observations of the B0s
→ψ(2S)η, B0 →ψ(2S)π
+
π
− and B0s
→ψ(2S)π
+
π
− decays are made
using a dataset corresponding to an integrated luminosity of 1.0 fb−1 collected by the LHCb experiment in
proton–proton collisions at a centre-of-mass energy of
√
s = 7 TeV. The ratios of the branching fractions
of each of the ψ(2S) modes with respect to the corresponding J/ψ decays are
B(B0s
→ψ(2S)η)
÷
B(B0s
→J/ψη)
= 0.83± 0.14 (stat)±0.12 (syst) ±0.02 (B),
;
B(B0→ψ(2S)π
+
π
−
)
÷
B(B0→J/ψπ
+
π
−
)
= 0.56± 0.07 (stat)±0.05 (syst)± 0.01 (B),
;
B(B0s
→ψ(2S)π
+
π
−
)
÷
B(B0s
→J/ψπ
+
π
−
)
= 0.34± 0.04 (stat)±0.03 (syst)± 0.01 (B),
where the third uncertainty corresponds to the uncertainties of the dilepton branching fractions of the J/ψ
and ψ(2S) meson decays
CHO-K1 sejtek osztódási és letapadási idejének, valamint területének meghatározási módszertana
No full textDolgozatomban a CHO-K1 sejtvonalból származó sejteket vizsgáltam. Szakirodalom kutatást végeztem alapvető tulajdonságaikról, majd az osztódási és letapadási idejüknek, valamint területüknek meghatározási módszertanát tanulmányoztam, amit egy általam tenyésztett CHO-K1 kultúrán keresztül be is mutattam.DOgjBiológiaBSc/B
Rapid emergence of a viral resistant mutant in WHV chronically infected woodchucks treated with lamivudine and a pre-S/S CHO-derived hepatitis B virus vaccine
No full textTo determine whether the addition of a pre-S/S human vaccine increases the antiviral activity of lamivudine, four woodchucks were treated with a daily dose of 100 mg/kg lamivudine and four 50 microg doses of CHO-derived pre-S/S human vaccine. WHV DNA titres decreased up to two logarithms in three woodchucks. At week 4, in three of the animals, the sequence analysis showed a predominant strain containing a nucleotide change from A to T at position 1696 of domain B of the WHV DNA polymerase. Vaccination did not further suppress WHV DNA, despite anti-HBs production in three animals. The woodchuck remains a useful model for characterising the biology and kinetics of the emergence of drug-resistant variants and could be used for pre-clinical studies of combinations of new antiviral drugs
Genotoxikus hatásra bekövetkező funkcionális és strukturális DNS változások = Functional and structural changes in DNA upon genotoxic effects
No full textMorfológiai és biokémiai vizsgálataink arra utalnak, hogy a a genotoxikus hatások kategorizálhatók az okozott kromatin változások alapján. A kemotoxikus változások potenciális diagnosztikus jelentősége miatt vizsgáltuk a nehézfémek (elsősosrban kadmium) (Banfalvi et al., 2005), a gamma sugárzás (Nagy et al., 2004), az UVB sugárzás (Ujvárosi et al., 2007) és a carcinogén (dimetilnitrózamin) hatására bekövetkező kromatin változásokat (Trencsényi et al., 2007). Kadmium kezelés jellegzetes szakadásokat és nagy lyukakat hozott létre a sejtmagban. A gamma sugárzás preapoptotikus hatására: a. a sejtek és sejtmagok mérete megnőtt, b. DNA tartalmuk a sejtciklus minden szakaszában kisebb volt a normál kezeletlen populációhoz képest, c. a sejtciklus a korai S fázisban leállt (2,4 C értéknél), d. a kromatin kondenzálás annak fibrilláris szakaszában akadt el, e. az apoptotikus testek száma és nagysága a sejtciklus haladásávalfordítva arányos: sok apró apoptotikus testtel az S fázis elején és kevés nagy apoptotikus testtel az S fázis végén. A CHO sejtekben mért vizsgálatokat humán K562 sejteken megerősítettük. UVB sugárzás hatására a kromoszómák nem voltak láthatók, a sérülés hatására vékony összefüggő kromatin fátyol vonta be mind az interfázisos, mind a metafázisos kromoszómákat. | Morphological and biochemical studies after genotoxic treatments suggest that the consequences of various chromatin injuries can be categorized based on the assessment of injury-specific chromatin changes. Due to its diagnostic significance, we have started to determine and systematize the effects of heavy metals, primarily cadmium treatment (Banfalvi et al., 2005), gamma irradiation (Nagy et al., 2004) and UV irradiation (Ujvarosi et al., 2007). After cadmium treatment and have seen the same large extensive disruptions and holes in the nuclear membrane and sticky incompletely folded chromosomes typical for cadmium treatment (Nagy et al., 2004; Banfalvi et al., 2007). Preapoptotic changes upon γ-irradiation manifested as: (a) The cellular and nuclear sizes increased. (b) The DNA content was lower in each elutriated subpopulation of cells. (c) The progression of the cell cycle was arrested in the early S phase at 2.4 C value. (d) The chromatin condensation was blocked at its fibrillary stage. (e) The number and size of apoptotic bodies were inversely correlated with the progression of the cell cycle, with many small apoptotic bodies in early S phase and less but larger apoptotic bodies in late S phase (Nagy et al., 2004). Similar observations were made in K562 cells (Banfalvi et al., 2007). UV irradiation blocked chromatin condensation at its fibrillary stage, nuclear structures were blurred and covered with fibrillary chromatin, neither interphase nor metaphase chromosomes were visible
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
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