216 research outputs found
Effect of compounds on the purification and antibody preparation of the extracellular domain fragment of the receptor CD163
<p>Abstract</p> <p>Background</p> <p>Porcine reproductive and respiratory syndrome virus (PRRSV) has been acknowledged as one of the most important agents affecting swine. The scavenger receptor CD163 is one of the important entry mediators for PRRSV.</p> <p>Results</p> <p>The tD4 and tD5 CD163 genes were amplified, and the PCR products were cloned into pET-28a(+) (designated pET-28a-tD4 and pET-28a-tD5, respectively). The plasmids pET-28a-tD4 and pET-28a-tD5 were then transformed into the <it>E. coli </it>BL21 (DE3) strain and expressed by adding 1 mmol/L of isopropyl-beta-D-thiogalactopyranoside. The proteins were highly expressed in the supernatant from the tD4- and tD5-producing cells that were incubated with a binding buffer containing the following compounds: β-mercaptoethanol, urea, Tween 20, glycerol, and SDS, while they were rarely expressed in the supernatant from the tD4- and tD5-producing cells that were incubated with binding buffer without the compounds. The tD4 and tD5 proteins were purified, and BALB/c mice were immunized with the purified proteins. Western blotting analysis showed that the tD4 and tD5 proteins were capable of reacting with tD5 antibodies; the titer of both the tD4 and tD5 antiserums was 1:160 against the tD5 protein, as shown by ELISA.</p> <p>Conclusions</p> <p>These studies provide a new way for the purification of proteins expressed in inclusion bodies and the preparation of the corresponding antibodies.</p
Genetic characterization of H1N2 influenza a virus isolated from sick pigs in Southern China in 2010
In China H3N2 and H1N1 swine influenza viruses have been circulating for many years. In January 2010, before swine were infected with foot and mouth disease in Guangdong, some pigs have shown flu-like symptoms: cough, sneeze, runny nose and fever. We collected the nasopharyngeal swab of all sick pigs as much as possible. One subtype H1N2 influenza viruses were isolated from the pig population. The complete genome of one isolate, designated A/swine/Guangdong/1/2010(H1N2), was sequenced and compared with sequences available in GenBank. The nucleotide sequences of all eight viral RNA segments were determined, and then phylogenetic analysis was performed using the neighbor-joining method. HA, NP, M and NS were shown to be closely to swine origin. PB2 and PA were close to avian origin, but NA and PB1were close to human origin. It is a result of a multiple reassortment event. In conclusion, our finding provides further evidence about the interspecies transmission of avian influenza viruses to pigs and emphasizes the importance of reinforcing swine influenza virus (SIV) surveillance, especially before the emergence of highly pathogenic FMDs in pigs in Guangdong
Search for hidden-charm tetraquark with strangeness in
We report a search for a heavier partner of the recently observed
state, denoted as , in the process , based on collision data
collected at the center-of-mass energies of , 4.682 and 4.699
GeV with the BESIII detector. The is of interest as it is
expected to be a candidate for a hidden-charm and open-strange tetraquark. A
partial-reconstruction technique is used to isolate recoil-mass spectra,
which are probed for a potential contribution from (). We find an excess of () candidates with a significance of , after
considering systematic uncertainties, at a mass of . As the data
set is limited in size, the upper limits are evaluated at the 90% confidence
level on the product of the Born cross section and the branching fraction of
, at the three energy points, under different assumptions
of the mass from 4.120 to 4.140 MeV and of the width from
10 to 50 MeV. Under various mass and width assumptions, the upper limits of
are found to lie in the range of ,
and pb at , 4.682 and 4.699 GeV,
respectively. The larger data samples that will be collected in the coming
years will allow a clearer picture to emerge concerning the existence and
nature of the state.Comment: 17 pages, 7 figure
Study of in decay
Using a sample of decays collected with
the BESIII detector, partial wave analyses of the decay are performed within the invariant mass region below 1.6 . The
covariant tensor amplitude method is used in both mass independent and mass
dependent approaches. Both analysis approaches exhibit dominant pseudoscalar
and axial vector components, and show good consistency for the other individual
components. Furthermore, the mass dependent analysis reveals that the
invariant mass spectrum for the pseudoscalar
component can be well described with two isoscalar resonant states, , the with a mass of
and a width of ,
and the with a mass of
and a width of .
The first and second uncertainties are statistical and systematic,
respectively. Alternate models for the pseudoscalar component are also tested,
but the description of the invariant mass spectrum
deteriorates significantly.Comment: 20 pages, 6 figures, 6 table
Production of doubly-charged baryon in annihilation at energies from 2.3094 to 2.6464 GeV
The processes and
are studied for the first
time with of annihilation data collected with
the BESIII detector at center-of-mass energies from GeV to
GeV. No significant signal for the
process is observed and the upper limit of the Born cross section is estimated
at each energy point. For the process , a significant signal is observed at center-of-mass energies
near 2.6454 GeV and the corresponding Born cross section is reported.Comment: 10 pages, 4 figure
Measurement of the -even fraction of
A determination of the -even fraction in the decay is presented. Using fb of
data collected by the BESIII detector, one
charm meson is reconstructed in the signal mode and the other in a
eigenstate or the decay . Analysis of the relative
rates of these double-tagged events yields the result , where the first uncertainty is statistical and the second is
systematic. This is the first model-independent measurement of in decays.Comment: 13 pages, 5 figure
Observation of the decay and measurement of its angular distribution
Using events collected with the
BESIII detector at the BEPCII collider, the decay
is observed for the first time with a
branching fraction of , and the angular parameter is
measured to be
Search for an axion-like particle in radiative decays
We search for an axion-like particle (ALP) through the process
, ,
in a data sample with
events collected by the BESIII detector. No significant ALP signal
is observed over the expected background, and the upper limits on the branching
fraction of the decay and the ALP-photon coupling
constant are set at the 95\% confidence level in the mass
range of 0.165\leq m_a\leq2.84\,\mbox{GeV}/c^2. The limits on
range from to
over the search region, and the constraints on the
ALP-photon coupling are the most stringent to date for 0.165\leq
m_a\leq1.468\,\mbox{GeV}/c^2.Comment: 10 pages, 5 figure
Observation of the and decays into
The decays and
are observed for the first time,
using and
events collected with the BESIII detector at the BEPCII collider.
We determine the branching fractions of these two decays to be and , where the first uncertainties are statistical
and the second are systematic. The ratio of these two branching fractions is
determined to be , which is in
agreement with the "12\% rule."Comment: 9 pages and 10 figure
Search for the weak decay $\psi(3686) \to \Lambda_c^{+} \bar{\Sigma}^- +c.c
Using events collected with the
BESIII detector, we perform the first search for the weak baryonic decay
. The analysis procedure is
optimized using a blinded method. No significant signal is observed, and the
upper limit on the branching fraction () of is set to be at the
90\% confidence level.Comment: 9 pages, 4 figure
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