542 research outputs found
Comparative Genomic Analysis of Latilactobacillus curvatus and L. sakei
In this study, the genomes of 19 Latilactobacillus curvatus and 40 L. sakei strains were comparatively analyzed. Average nucleic acid identity (ANI) and genome-wide colinearity indicated that the genomes of L. curvatus and L. sakei had weak nucleotide sequence homology, allowing them to be used as indicators to distinguish the two species. Pangenomes for these species were constructed, whose core gene functions were annotated. The results showed that the core genomes of L. curvatus and L. sakei were mainly involved in their basic metabolism. Analysis of individual genomes of the strains revealed that 1) both L. curvatus and L. sakei contained a wide range of genes encoding glycoside hydrolases, which are abundant genetic resources for catabolizing and metabolizing dietary fiber such as polysaccharides, lactose utilization, and lignocellulose; 2) antibiotic resistance genes were annotated in the genomes of three strains, which originate from horizontal gene transfer; 3) the unique arginine deiminase pathway of L. sakei, the serine dehydratase and guanine deaminase pathways of L. curvatus, and the glutamate decarboxylase pathway of several strains were identified, revealing that the acid tolerance mechanisms of these two species are different; and 4) genes encoding cold stress proteins were discovered, which endow the two species with good cold processing properties. Moreover, the genomes of some L. sakei strains contained gene clusters related to the biosynthesis of lactocin S and condensin. In conclusion, this study established taxonomic criteria for the two species and information on individual differences between their strains, which will provide a basis for the study of the physiological, biochemical, molecular genetic mechanisms of L. curvatus and L. sakei and their industrial applications
Intraocular pressure effect of intravitreal conbercept injection for retinopathy of prematurity
Purpose: Intravitreal injection of conbercept (IVC) is a novel anti-vascular endothelial growth factor (anti-VEGF) treatment for retinopathy of prematurity (ROP). This study aimed to assess the intraocular pressure (IOP) effect of IVC.Methods: All IVC surgeries were performed in the Department of Ophthalmology, Guangdong Women and Children Hospital, from January 2021 to May 2021. In this study, 30 eyes of 15 infants who received intravitreal injections of conbercept at a dose of 0.25 mg/0.025 mL were included. The IOP of all participants was measured prior to administering the injection and subsequently at 2 min, 1 h, 1 day, and 1 week thereafter.Results: We included 30 eyes (10 boys and 5 girls) with ROP. For the male group, the mean birth weight, mean gestational age at birth, and the mean time of postmenstrual age (PMA) at IVC treatment were 1,174.0 ± 446.0 g, 28.4 ± 3.0 weeks, and 37.1 ± 1.6 weeks, respectively; for the female group, they were 1,108 ± 285.5 g, 28.2 ± 2.5 weeks, and 36.8 ± 2.1 weeks, respectively. For the male group, the IOP at baseline, 2 min, 1 h, 1 day, and 1 week after IVC were 12.4 ± 1.5 mmHg, 49.0 ± 3.1 mmHg, 26.3 ± 2.5 mmHg, 13.4 ± 2.2 mmHg, and 11.6 ± 1.7 mmHg, respectively; for the female group, they were 10.7 ± 2.0 mmHg, 47.3 ± 3.2 mmHg, 26.4 ± 3.2 mmHg, 10.7 ± 1.8 mmHg, and 10.2 ± 1.8 mmHg, respectively. In both groups, the IOP immediately (2 min) after the operation was significantly higher than that at any other time point (p < 0.01). IOP values returned to the preoperative baseline level on the first day after surgery, with no significant difference compared with that before injection (p > 0.05). IOP continued to be maintained at the preoperative baseline level on the first week after surgery, with no significant difference compared with that before surgery (p > 0.05).Conclusion: Infants with ROP who received IVC experienced a sharp increase in the IOP immediately after injection, which decreased to below 30 mmHg after 1 h and maintain that level for 1 week or longer
Spatial and temporal variations of nitrous oxide flux between coastal marsh and the atmosphere in the Yellow River estuary of China
Study of the doubly Cabibbo-suppressed decays and
Based on 7.33 fb of collision data collected at
center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector,
the experimental studies of the doubly Cabibbo-suppressed decays and are reported. We determine the
absolute branching fraction of to be
() . No
significant signal of is observed and the upper
limit on its decay branching fraction at 90\% confidence level is set to be
.Comment: 10 pages, 4 figures, 4 table
Updated measurements of the M1 transition with
Based on a data sample of events
collected with the BESIII detector at the BEPCII collider, the M1 transition
with is
studied, where is or
. The mass and width of the are
measured to be MeV/
and MeV, respectively. The
product branching fraction is determined to be . Using , we obtain the branching fraction of the
radiative transition to be , where the third uncertainty is due to the quoted
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
Precise Measurements of Decay Parameters and Asymmetry with Entangled Pairs
Based on 10 billion events collected at the BESIII experiment, a
search for violation in decay is performed in the difference
between -odd decay parameters for
and for by using the
process . With a
five-dimensional fit to the full angular distributions of the daughter baryon,
the most precise values for the decay parameters are determined to be
and , respectively. The and averaged
value of the decay parameter is extracted to be with unprecedented accuracy. The asymmetry
is determined to be
, which is one of the most precise measurements
in the baryon sector. The reported results for the decay parameter will play an
important role in the studies of the polarizations and violations for the
strange, charmed and beauty baryons
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
Amplitude analysis and branching fraction measurement of the decay \boldmath
The singly Cabibbo-suppressed decay
is observed, using a data set corresponding to an integrated luminosity of 6.32
recorded by the BESIII detector at the centre-of-mass energies
between 4.178 and 4.226 GeV. The first amplitude analysis of reveals the sub-structures in this decay and
determines the fractions and relative phases of different intermediate
processes. The dominant intermediate process is , with
a fit fraction of . With the
detection efficiency based on our amplitude analysis, the absolute branching
fraction for is measured to be
Observation of the and evidence for a new vector charmonium-like state in
Cross sections for the process
at center-of-mass energies from to GeV are measured using data
samples with a total integrated luminosity of 21.2 fb collected by the
BESIII detector operating at the BEPCII storage ring. The state is
observed in the energy dependence of the cross section for the first time with a statistical significance of
26.0. In addition, an enhancement around GeV, called the
, is seen with a statistical significance of 4.2. There is no
clear structure around GeV. Using a fit with a coherent sum of three
Breit-Wigner functions, we determine the mass and width of the state
to be MeV/ and MeV,
respectively, and the mass and width of the state to be MeV/ and MeV, respectively,
where the first uncertainties are statistical and the second are systematic. In
addition, the average Born cross section ratio of to is measured to be
, or if
three-body phase space is considered.Comment: Update draft based the comments from PRD refere
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