414 research outputs found
CCD photometric study of the W UMa-type binary II CMa in the field of Berkeley 33
The CCD photometric data of the EW-type binary, II CMa, which is a contact
star in the field of the middle-aged open cluster Berkeley 33, are presented.
The complete R light curve was obtained. In the present paper, using the five
CCD epochs of light minimum (three of them are calculated from Mazur et al.
(1993)'s data and two from our new data), the orbital period P was revised to
0.22919704 days. The complete R light curve was analyzed by using the 2003
version of W-D (Wilson-Devinney) program. It is found that this is a contact
system with a mass ratio and a contact factor . The high mass
ratio () and the low contact factor () indicate that the system
just evolved into the marginal contact stage
Holographic study of higher-order baryon number susceptibilities at finite temperature and density
The cumulants of baryon number fluctuations serve as a good probe for
experimentally exploring the QCD phase diagram at finite density, giving rise
to characteristic fluctuation patterns associated with a possible critical
endpoint (CEP). We compute the higher-order baryon number susceptibilities at
finite temperature and baryon chemical potential using a holographic QCD model
to address the non-perturbative aspect of strongly coupled QCD matter. The
model can accurately confront lattice QCD data on a quantitative level and the
location of the CEP is found to fall within the range accessible to upcoming
experimental measurements. The baryon number susceptibilities up to the twelfth
order are computed, and the collision energy dependence of different ratios of
these susceptibilities is examined along the chemical freeze-out line. The
holographic results show quantitative agreement with experimental data and the
functional renormalization group results in a large collision energy range,
with all ratios exhibiting a peak structure around 5-10 GeV. The mismatching
between our holographic results with experimental data for sufficiently low
collision energy is possibly due to non-equilibrium effects and complex
experimental environments. The future experiments with measurements in the low
collision energy range and reduced
experimental uncertainty could reveal more non-monotonic behavior signals which
can be used to locate the CEP.Comment: 15 pages, 7 figure
Acute limb ischemia caused by floating thrombus in the aorta: a case report and literature review
This report presents a patient with rheumatoid arthritis and COVID-19 infection one month earlier who experienced embolic episodes resulting in acute lower-limb ischemia from an unusual source. The blood flow was successfully restored by femoropopliteal thromboembolectomy. In determining the source of the embolism, the patient underwent electrocardiogram, transthoracic echocardiogram, and aortic CTA. The latter revealed a large, pedunculated, and mobile thrombus arising from the aortic arch and the descending thoracic aorta. Considering the patient's general health condition, we performed anticoagulation of the floating thrombus in the aortic lumen. The mechanism of aortic floating thrombosis exhibits considerable complexity. There are no standardized treatment protocols or clinical guidelines, and its treatment mainly includes open surgery, aortic endoluminal stent -graft insertion and pharmacological anticoagulation. Treatment strategy should be based on the cause of the disease and the patient's physical condition
Phase diagram of holographic thermal dense QCD matter with rotation
We study the rotation effects of the hot and dense QCD matter in a
non-perturbative regime by the gauge/gravity duality. We use the gravitational
model that is designated to match the state-of-the-art lattice data on the
thermal properties of (2+1)-flavor QCD and predict the location of the critical
endpoint and the first-order phase transition line at large baryon chemical
potential without rotation. After introducing the angular velocity via a local
Lorentz boost, we investigate the thermodynamic quantities for the system under
rotation in a self-consistent way. We find that the critical temperature and
baryon chemical potential associated with the QCD phase transition decrease as
the angular velocity increases. Moreover, some interesting phenomena are
observed near the critical endpoint. We then construct the 3-dimensional phase
diagram of the QCD matter in terms of temperature, baryon chemical potential,
and angular velocity. As a parallel investigation, we also consider the
gravitational model of pure gluon system, for which the 2-dimensional
phase diagram associated with temperature and angular velocity has been
predicted. The corresponding thermodynamic quantities with rotation are
investigated.Comment: 22 pages, 24 figure
Contribution of recycled moisture to local precipitation in the inland Heihe River Basin
Recycled moisture contributed by continental evaporation and transpiration plays an important role in regulating the hydrological processes and atmospheric humidity budget in arid inland river basins. However, knowledge of moisture recycling within many large inland basins and the factors that control moisture recycling is generally lacking. Based on a three-component isotopic mixing model, we assessed the characteristics of moisture recycling in China’s semi-arid Heihe River Basin. During the active growing season, almost half of the precipitation in the upper reaches was provided by local moisture recycling, and the main contribution came from transpiration. In the middle reaches, almost half of the precipitation in the artificial oasis and the desert-oasis ecotone was also provided by local moisture recycling, and the transpiration fraction (fTr) and evaporation fraction (fEv) of the artificial oasis differed from those of the desert-oasis ecotone. In the lower reaches, less than 25% of the precipitation was provided by local moisture recycling. Mean fTr values were relatively low in the Gobi (15.0%) in the middle reaches and in the riparian forest at Ejina (25.6%) in the lower reaches. The positive correlations between fTr and both precipitation and relative humidity suggest that higher precipitation and relative humidity promote transpiration fraction, whereas higher vapor pressure deficit reduces transpiration fraction. The positive correlation between fEv and temperature and vapor pressure deficit, and the negative correlation between fEv and relative humidity indicate that higher temperature and vapor pressure deficit promotes evaporation fraction, whereas higher relative humidity reduces the evaporation fraction. Our results show that contributions of recycled moisture (especially transpiration) to local precipitation play an important role in regional water resource redistribution in the arid and semi-arid region of northwestern China
Aberrant Methylation of Thrombospondin-1 and Its Association with Reduced Expression in Gastric Cardia Adenocarcinoma
Aim. Investigate the promoter methylation of the Thrombospondin-1 (TSP1) gene in gastric cardia adenocarcinoma (GCA). Methods. MSP approach, immunohistochemistry method, and RT-PCR were used respectively to examine the promoter methylation of TSP1, its protein and mRNA expression in tumors and corresponding normal tissues. The expression and concentration of TGF-β1 were examined respectively by immunohistochemistry and ELISA method. The status of T cell immunity was examined by Flow cytometry analysis. Results. TSP1 was methylated in 34/96 (35.4%) tumor specimens, which was significantly higher than that in corresponding normal tissues (P < .001). Protein and mRNA expression of TSP1 in GCA tumor tissues were reduced significantly and were associated with TSP1 methylation. The protein expression of TGF-β1 was significantly higher in tumor tissues (P < .001) and was associated with TNM stage and histological differentiation. The concentration of active and total TGF-β1 did not show significant difference between the GCA patients with hypermethylation of TSP1 and without methylation of TSP1 (P > .05). The function of T cell immunity was significantly different between the GCA patients with hypermethylation of TSP1 and without methylation of TSP1. Conclusions. Epigenetic silencing of TSP1 gene by promoter hypermethylation may play an important role in GCA
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