113 research outputs found
Constraining the HI-Halo Mass Relation From Galaxy Clustering
We study the dependence of galaxy clustering on atomic gas mass using a
sample of 16,000 galaxies with redshift in the range of
and HI mass of , drawn from the 70% complete sample
of the Arecibo Legacy Fast ALFA survey. We construct subsamples of galaxies
with above different thresholds, and make volume-limited
clustering measurements in terms of three statistics: the projected two-point
correlation function, the projected cross-correlation function with respect to
a reference sample selected from the Sloan Digital Sky Survey, and the
redshift-space monopole moment. In contrast to previous studies, which found
no/weak HI-mass dependence, we find both the clustering amplitude on scales
above a few Mpc and the bias factors to increase significantly with increasing
HI mass for subsamples with HI mass thresholds above . For HI
mass thresholds below , while the measurements have large
uncertainties caused by the limited survey volume and sample size, the inferred
galaxy bias factors are systematically lower than the minimum halo bias factor
from mass-selected halo samples. The simple halo model, in which galaxy content
is only determined by halo mass, has difficulties in interpreting the
clustering measurements of the HI-selected samples. We extend the simple model
by including the halo formation time as an additional parameter. A model that
puts HI-rich galaxies into halos that formed late can reproduce the clustering
measurements reasonably well. We present the implications of our best-fitting
model on the correlation of HI mass with halo mass and formation time, as well
as the halo occupation distributions and HI mass functions for central and
satellite galaxies. These results are compared with the predictions from
semi-analytic galaxy formation models and hydrodynamic galaxy formation
simulations.Comment: Accepted for publication in ApJ. The 2PCF measurements are available
at http://sdss4.shao.ac.cn/guoh
Realistic Volume Rendering with Environment-Synced Illumination in Mixed Reality
Interactive volume visualization using a mixed reality (MR) system helps
provide users with an intuitive spatial perception of volumetric data. Due to
sophisticated requirements of user interaction and vision when using MR
head-mounted display (HMD) devices, the conflict between the realisticness and
efficiency of direct volume rendering (DVR) is yet to be resolved. In this
paper, a new MR visualization framework that supports interactive realistic DVR
is proposed. An efficient illumination estimation method is used to identify
the high dynamic range (HDR) environment illumination captured using a panorama
camera. To improve the visual quality of Monte Carlo-based DVR, a new
spatio-temporal denoising algorithm is designed. Based on a reprojection
strategy, it makes full use of temporal coherence between adjacent frames and
spatial coherence between the two screens of an HMD to optimize MR rendering
quality. Several MR development modules are also developed for related devices
to efficiently and stably display the DVR results in an MR HMD. Experimental
results demonstrate that our framework can better support immersive and
intuitive user perception during MR viewing than existing MR solutions.Comment: 6 pages, 6 figure
JNK pathway promotes hepatocyte apoptosis by inhibiting Bcl-2 and upregulating expressions of Bim, caspase-3 and caspase-9 after cardiopulmonary bypass
Purpose: To study the effect of Jun N-terminal kinase (JNK) signaling pathway on hepatocyte apoptosis in vivo and in vitro, and to elucidate the mechanism of action.
Methods: TdT-mediated dUTP Nick-End Labeling (TUNEL) method was used to determine apoptosis in control and cardiopulmonary bypass (CPB) groups at 0, 3 and 6 hours after rat surgery. The expressions of JNK and p-c-Jun in liver tissues at 0, 3 and 6 h after surgery, and the levels of p-c-Jun, Bcl-2 and Bim following overexpression of JNK, were determined using Western blot assay. Human liver cell line HL-7702 was cultured and transfected with over-expressed JNK plasmid and empty plasmid. Proliferation of HL-7702 cells after JNK over-expression was assessed by Cell Counting Kit-8 (CCK-8), while quantitative real-time polymerase chain reaction (RT-qPCR) was employed to evaluate mRNA expression levels of caspase-3 and caspase-9 mRNA after JNK over-expression. Apoptosis of the cells was determined by flow cytometry (FC) after JNK over-expression.
Results: FC results showed that the number of apoptotic hepatocytes increased after JNK overexpression in hepatocytes while TUNEL assay results demonstrated that hepatocyte apoptosis increased in CPB group, when compared to control group; furthermore, the number of apoptotic cells gradually increased within 6 h after surgery. The expressions of JNK and p-c-Jun were higher in CPB group than in control group, and increased gradually in both groups within 6 h after surgery. Overexpression of JNK decreased the proliferation of hepatocytes, and also lowered protein expression levels of p-c-Jun and Bim; on the other hand, the protein expression levels of Bcl-2 fell, while mRNA expression levels of caspase-3 and caspase-9 mRNA increased.
Conclusion: JNK pathway promotes hepatocyte apoptosis after cardiopulmonary bypass by inhibiting Bcl-2 pathway and promoting the expressions of Bim caspase-3 and caspase-9.
Keywords: Cardiopulmonary bypass, Apoptosis, JNK pathway, Bim, caspase-3 and caspase-
A highly flexible supercapacitor based on MnO2/RGO nanosheets and bacterial cellulose-filled gel electrolyte
The flexible supercapacitors (SCs) of the conventional sandwich-type structure have poor flexibility due to the large thickness of the final entire device. Herein, we have fabricated a highly flexible asymmetric SC using manganese dioxide (MnO2) and reduced graphene oxide (RGO) nanosheet-piled hydrogel films and a novel bacterial cellulose (BC)-filled polyacrylic acid sodium salt-Na2SO4 (BC/PAAS-Na2SO4) neutral gel electrolyte. Apart from being environmentally friendly, this BC/PAAS-Na2SO4 gel electrolyte has high viscosity and a sticky property, which enables it to combine two electrodes together. Meanwhile, the intertangling of the filled BC in the gel electrolyte hinders the decrease of the viscosity with temperature, and forms a separator to prevent the two electrodes from short-circuiting. Using these materials, the total thickness of the fabricated device does not exceed 120 μm. This SC device demonstrates high flexibility, where bending and even rolling have no obvious effect on the electrochemical performance. In addition, owing to the asymmetric configuration, the cell voltage of this flexible SC has been extended to 1.8 V, and the energy density can reach up to 11.7 Wh kg-1 at the power density of 441 W kg-1. This SC also exhibits a good cycling stability, with a capacitance retention of 85.5% over 5000 cycles. © 2017 by the authors.Ministry of Education, Youth, and Sports of the Czech Republic [LTACH17015]; NPU Program I [LO1504]; Operational Program Research and Development for Innovations - European Regional Development Fund (ERDF); national budget of the Czech Republic within the framework of the CPSstrengthening research capacity [CZ.1.05/2.1.00/19.0409]; Tomas Bata University in Zlin, Czech Republic [IGA/CPS/2015/008, IGA/CPS/2016/003
Safety profile of intravenous digoxin in Chinese patients with acute heart failure with reduced ejection fraction: a small-scale prospective cohort study
Background: Adverse effects of intravenous digoxin vary from patients and disease status, which should be closely monitored.Aims: To explore the safety profile of intravenous digoxin in acute heart failure with reduced ejection fraction (HFrEF) among Chinese patients.Methods: A clinical prospective, single-center, single-arm, open-label exploratory clinical trial was performed in patients with acute HFrEF at Wuhan Asia Heart Hospital. A fixed dose of 0.5 mg digoxin was used intravenously once per day for 3 days. The normalized dosage of digoxin (NDD), toxic serum digoxin concentration (SDC), and adverse reactions of intravenous digoxin were recorded.Results: A total of 40 patients were recruited in the study. The SDC increased from 1.03 ± 0.34 ng/mL to 1.95 ± 0.52 ng/mL during treatment. 50% (20/40) patients reached a toxic SDC of 2.0 ng/mL, and toxic effects were seen in 30% (12/40) patients. Estimated glomerular filtration rate (eGFR) < 60 mL/min [HR: 5.269; 95% CI: 1.905–14.575, p = 0.001], NDD ≥7 μg/kg [HR: 3.028; 95% CI: 1.119–8.194, p = 0.029], and ischemic cardiomyopathy [HR: 2.658; 95% CI: 1.025–6.894, p = 0.044] were independent risk factors for toxic SDC. Toxic SDC was effectively identified [area under the receiver operating characteristic (ROC) curve = 0.85, p < 0.001] using this model, and patients would have a higher risk of toxicity with more risk factors.Conclusion: Intravenous digoxin of 0.5 mg was safe and effective for initial dose but not suitable for maintenance treatment in Chinese patients with acute HFrEF. Patients who had lower eGFR, received higher NDD, and had ischemic cardiomyopathy should be closely monitored to avoid digoxin toxicity
CBP loss cooperates with PTEN haploinsufficiency to drive prostate cancer: implications for epigenetic therapy
Despite the high incidence and mortality of prostate cancer, the etiology of this disease is not fully understood. In this study, we develop functional evidence for CBP and PTEN interaction in prostate cancer based on findings of their correlate expression in the human disease. Cbppc−/−;Ptenpc+/− mice exhibited higher cell proliferation in the prostate and an early onset of high-grade prostatic intraepithelial neoplasia. Levels of EZH2 methyltransferase were increased along with its Thr350 phosphorylation in both mouse Cbp−/−;Pten+/− and human prostate cancer cells. CBP loss and PTEN deficiency cooperated to trigger a switch from K27-acetylated histone H3 to K27-trimethylated bulk histones, in a manner associated with decreased expression of the growth inhibitory EZH2 target genes DAB2IP, p27KIP1 and p21CIP1. Conversely, treatment with the histone deacetylase inhibitor panobinostat reversed this switch, in a manner associated with tumor suppression in Cbppc−/−;Ptenpc+/− mice. Our findings show how CBP and PTEN interact to mediate tumor suppression in the prostate, establishing a central role for histone modification in the etiology of prostate cancer and providing a rationale for clinical evaluation of epigenetic targeted therapy in prostate cancer patients
Evaluating the Prognostic Accuracy of Biomarkers for Glioblastoma Multiforme Using The Cancer Genome Atlas Data
Background: Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor. Previous studies on GBM biomarkers focused on the effect of the biomarkers on overall survival (OS). Until now, no study has been published that evaluates the performance of biomarkers for prognosing OS. We examined the performance of microRNAs, gene expressions, gene signatures, and methylation that were previously identified to be prognostic. In addition, we investigated whether using clinical risk factors in combination with biomarkers can improve the prognostic performance. Methods: The Cancer Genome Atlas, which provides both biomarkers and OS information, was used in this study. The time-dependent receiver operating characteristic (ROC) curve was used to evaluate the prognostic accuracy. Results: For prognosis of OS by 2 years from diagnosis, the area under the ROC curve (AUC) of microRNAs, Mir21 and Mir222, was 0.550 and 0.625, respectively. When age was included in the risk prediction score of these biomarkers, the AUC increased to 0.719 and 0.701, respectively. The SAMSN1 gene expression attains an AUC of 0.563, and the “8-gene” signature identified by Bao achieves an AUC of 0.613. Conclusions: Although some biomarkers are significantly associated with OS, the ability of these biomarkers for prognosing OS events is limited. Incorporating clinical risk factors, such as age, can greatly improve the prognostic performance
A Deep Learning Method for Facies Recognition from Core Images and Its Application: A Case Study of Mackay River Oil Sands Reservoir
There is a large amount of drilling core data in the Mackay River oil sands block in Canada, and the accurate identification of facies from the cores is important and necessary for the understanding of the subsurface reservoir. The traditional recognition method of facies from cores is by human work and is very time consuming. Furthermore, the results are different according to different geologists because of the subjective judgment criterion. An efficient and objective method is important to solve the above problem. In this paper, the deep learning image-recognition algorithm is used to automatically and intelligently recognize the facies type from the core image. Through a series of high-reliability preprocessing operations, such as cropping, segmentation, rotation transformation, and noise removal of the original core image, that have been manually identified, the key feature information in the images is extracted based on the ResNet50 convolutional neural network. On the dataset of about 200 core images from 13 facies, an intelligent identification system of facies from core images is constructed, which realizes automatic facies identification from core images. Comparing this method with traditional convolutional neural networks and support vector machines (SVM), the results show that the recognition accuracy of this model is as high as 91.12%, which is higher than the other two models. It is also shown that for a relatively special dataset, such as core images, it is necessary to rely on their global features in order to classify them, and, with a large similarity between some of the categories, it is extremely difficult to classify them. The selection of a suitable neural network model can have a great impact on the accuracy of recognition results. Then, the recognized facies are input as hard data to construct the three-dimensional facies model, which reveals the complex heterogeneity and distribution of the subsurface reservoir for further exploration and development
- …