1,789 research outputs found
Effects of NaCl treatment on the antioxidant enzymes of oilseed rape (Brassica napus L.) seedlings
The effects of NaCl treatment on the activity of antioxidant enzymes in leaves of oilseed rape seedlings (Brassica napus L.) were studied. The results showed that the relative water content from leaves of oilseed rape seedlings was gradually decreased and the electronic conductivity was increased during 0 - 24 h under 200 mmol.l-1 NaCl treatments. The activity of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) was gradually increased during 0 - 24 h under 200 mmol.l-1 NaCl stress. After 24 h, the activities of these antioxidases were maximum and subsequently decreased. Quantitative realtime PCR analysis revealed that they were salt-inducible genes and their transcript levels were gradually increased during 0 - 24 h and most abundant after 24 h treatment with 200 mmol.l-1 sodium chloride. Therefore, these results from above indicated that the expressions of POD, SOD and CAT genes were induced by NaCl; the activities of POD, SOD and CAT were increased, which enhanced the tolerance of oilseed oilseed rape plants against NaCl stress
Novel Role of Endothelial Derived Exosomal HSPA12B in Regulating Macrophage Inflammatory Responses in Polymicrobial Sepsis
Endothelial cell dysfunction contributes to sepsis induced initiate immune response and the infiltration of immune cells into organs, resulting in organ injury. Heat shock protein A12B (HSPA12B) is predominantly expressed in endothelial cells. The present study investigated whether endothelial HSPA12B could regulate macrophage pro-inflammatory response during sepsis. Wild type (WT) and endothelial cell-specific HSPA12B deficient (HSPA12B–/–) mice were subjected to CLP sepsis. Mortality and cardiac function were monitored. Higher mortality, worsened cardiac dysfunction, and greater infiltrated macrophages in the myocardium and spleen were observed in HSPA12B–/– septic mice compared with the WT septic mice. The serum levels of TNF-α and IL-1β were higher and the levels of IL-10 were lower in HSPA12B–/– septic mice than in WT septic mice. Importantly, endothelial exosomes contain HSPA12B which can be uptaken by macrophages. Interestingly, endothelial exosomal HSPA12B significantly increases IL-10 levels and decreases TNF-α and IL-1β production in LPS-stimulated macrophages. Mechanistic studies show that endothelial exosomal HSPA12B downregulates NF-κB activation and nuclear translocation in LPS stimulated macrophages. These data suggest that endothelial HSPA12B plays a novel role in the regulation of macrophage pro-inflammatory response via exosomes during sepsis and that sepsis induced cardiomyopathy and mortality are associated with endothelial cell deficiency of HSPA12B
Study of and
The decays and have been
investigated with a sample of 225.2 million events collected with the
BESIII detector at the BEPCII collider. The branching fractions are
determined to be and . Distributions of the angle
between the proton or anti-neutron and the beam direction are well
described by the form , and we find
for and
for . Our branching-fraction
results suggest a large phase angle between the strong and electromagnetic
amplitudes describing the decay.Comment: 16 pages, 13 figures, the 2nd version, submitted to PR
First observation of the M1 transition
Using a sample of 106 million \psi(3686) events collected with the BESIII
detector at the BEPCII storage ring, we have made the first measurement of the
M1 transition between the radially excited charmonium S-wave spin-triplet and
the radially excited S-wave spin-singlet states: \psi(3686)\to\gamma\eta_c(2S).
Analyses of the processes \psi(2S)\to \gamma\eta_c(2S) with \eta_c(2S)\to
\K_S^0 K\pi and K^+K^-\pi^0 gave an \eta_c(2S) signal with a statistical
significance of greater than 10 standard deviations under a wide range of
assumptions about the signal and background properties. The data are used to
obtain measurements of the \eta_c(2S) mass (M(\eta_c(2S))=3637.6\pm
2.9_\mathrm{stat}\pm 1.6_\mathrm{sys} MeV/c^2), width
(\Gamma(\eta_c(2S))=16.9\pm 6.4_\mathrm{stat}\pm 4.8_\mathrm{sys} MeV), and the
product branching fraction (\BR(\psi(3686)\to \gamma\eta_c(2S))\times
\BR(\eta_c(2S)\to K\bar K\pi) = (1.30\pm 0.20_\mathrm{stat}\pm
0.30_\mathrm{sys})\times 10^{-5}). Combining our result with a BaBar
measurement of \BR(\eta_c(2S)\to K\bar K \pi), we find the branching fraction
of the M1 transition to be \BR(\psi(3686)\to\gamma\eta_c(2S)) = (6.8\pm
1.1_\mathrm{stat}\pm 4.5_\mathrm{sys})\times 10^{-4}.Comment: 7 pages, 1 figure, 1 tabl
Two-photon widths of the states and helicity analysis for \chi_{c2}\ar\gamma\gamma}
Based on a data sample of 106 M events collected with the
BESIII detector, the decays \psi^{\prime}\ar\gamma\chi_{c0, 2},\chi_{c0,
2}\ar\gamma\gamma are studied to determine the two-photon widths of the
states. The two-photon decay branching fractions are determined
to be {\cal B}(\chi_{c0}\ar\gamma\gamma) = (2.24\pm 0.19\pm 0.12\pm
0.08)\times 10^{-4} and {\cal B}(\chi_{c2}\ar\gamma\gamma) = (3.21\pm 0.18\pm
0.17\pm 0.13)\times 10^{-4}. From these, the two-photon widths are determined
to be keV,
keV, and
, where the uncertainties
are statistical, systematic, and those from the PDG {\cal
B}(\psi^{\prime}\ar\gamma\chi_{c0,2}) and errors,
respectively. The ratio of the two-photon widths for helicity and
helicity components in the decay \chi_{c2}\ar\gamma\gamma is
measured for the first time to be .Comment: 10 pages, 4 figure
Epidemiologic Features and Environmental Risk Factors of Severe Fever with Thrombocytopenia Syndrome, Xinyang, China
Background:Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease discovered in rural areas of Central China in 2009, caused by a novel bunyavirus, SFT
FAST observations of an extremely active episode of FRB 20201124A: IV. Spin Period Search
We report the properties of more than 800 bursts detected from the repeating
fast radio burst (FRB) source FRB 20201124A with the Five-hundred-meter
Aperture Spherical radio telescope (FAST) during an extremely active episode on
UTC September 25th-28th, 2021 in a series of four papers. In this fourth paper
of the series, we present a systematic search of the spin period and linear
acceleration of the source object from both 996 individual pulse peaks and the
dedispersed time series. No credible spin period was found from this data set.
We rule out the presence of significant periodicity in the range between 1 ms
to 100 s with a pulse duty cycle (when the profile is defined
by a von-Mises function, not a boxcar function) and linear acceleration up to
m s in each of the four one-hour observing sessions, and up to
m s in all 4 days. These searches contest theoretical scenarios
involving a 1 ms to 100 s isolated magnetar/pulsar with surface magnetic field
G and a small duty cycle (such as in a polar-cap emission mode) or a
pulsar with a companion star or black hole up to 100 M and
hours. We also perform a periodicity search of the fine structures and
identify 53 unrelated millisecond-timescale "periods" in multi-components with
the highest significance of 3.9 . The "periods" recovered from the fine
structures are neither consistent nor harmonically related. Thus they are not
likely to come from a spin period. We caution against claiming spin periodicity
with significance below 4 with multi-components from one-off
FRBs. We discuss the implications of our results and the possible connections
between FRB multi-components and pulsar micro-structures.Comment: Accepted by Research in Astronomy and Astrophysics (RAA
Observation of the exceptional-point-enhanced Sagnac effect
Exceptional points (EPs) are special spectral degeneracies of non-Hermitian Hamiltonians that govern the dynamics of open systems. At an EP, two or more eigenvalues, and the corresponding eigenstates, coalesce. Recently, it was predicted that operation of an optical gyroscope near an EP results in improved response to rotations. However, the performance of such a system has not been examined experimentally. Here we introduce a precisely controllable physical system for the study of non-Hermitian physics and nonlinear optics in high-quality-factor microresonators. Because this system dissipatively couples counter-propagating lightwaves within the resonator, it also functions as a sensitive gyroscope for the measurement of rotations. We use our system to investigate the predicted EP-enhanced Sagnac effect and observe a four-fold increase in the Sagnac scale factor by directly measuring rotations applied to the resonator. The level of enhancement can be controlled by adjusting the system bias relative to the EP, and modelling results confirm the observed enhancement. Moreover, we characterize the sensitivity of the gyroscope near the EP. Besides verifying EP physics, this work is important for the understanding of optical gyroscopes
Pulmonary Tuberculosis and Delay in Anti-Tuberculous Treatment Are Important Risk Factors for Chronic Obstructive Pulmonary Disease
OBJECTIVE: Tuberculosis (TB) remains the leading cause of death among infectious diseases worldwide. It has been suggested as an important risk factor of chronic obstructive pulmonary disease (COPD), which is also a major cause of morbidity and mortality. This study investigated the impact of pulmonary TB and anti-TB treatment on the risk of developing COPD. DESIGN, SETTING, AND PARTICIPANTS: This cohort study used the National Health Insurance Database of Taiwan, particularly the Longitudinal Health Insurance Database 2005 to obtain 3,176 pulmonary TB cases and 15,880 control subjects matched in age, sex, and timing of entering the database. MAIN OUTCOME MEASURES: Hazard ratios of potential risk factors of COPD, especially pulmonary TB and anti-TB treatment. RESULTS: The mean age of pulmonary TB cases was 51.9±19.2. The interval between the initial study date and commencement of anti-TB treatment (delay in anti-TB treatment) was 75.8±65.4 days. Independent risk factors for developing COPD were age, male, low income, and history of pulmonary TB (hazard ratio 2.054 [1.768-2.387]), while diabetes mellitus was protective. The impact of TB persisted for six years after TB diagnosis and was significant in women and subjects aged >70 years. Among TB patients, delay in anti-TB treatment had a dose-response relationship with the risk of developing COPD. CONCLUSIONS: Some cases of COPD may be preventable by controlling the TB epidemic, early TB diagnosis, and prompt initiation of appropriate anti-TB treatment. Follow-up care and early intervention for COPD may be necessary for treated TB patients
A Robust Approach to Identifying Tissue-Specific Gene Expression Regulatory Variants Using Personalized Human Induced Pluripotent Stem Cells
Normal variation in gene expression due to regulatory polymorphisms is often masked by biological and experimental noise. In addition, some regulatory polymorphisms may become apparent only in specific tissues. We derived human induced pluripotent stem (iPS) cells from adult skin primary fibroblasts and attempted to detect tissue-specific cis-regulatory variants using in vitro cell differentiation. We used padlock probes and high-throughput sequencing for digital RNA allelotyping and measured allele-specific gene expression in primary fibroblasts, lymphoblastoid cells, iPS cells, and their differentiated derivatives. We show that allele-specific expression is both cell type and genotype-dependent, but the majority of detectable allele-specific expression loci remains consistent despite large changes in the cell type or the experimental condition following iPS reprogramming, except on the X-chromosome. We show that our approach to mapping cis-regulatory variants reduces in vitro experimental noise and reveals additional tissue-specific variants using skin-derived human iPS cells
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