The progenitors of type Ia supernovae in the semidetached binaries with red giant donors

Context. The companions of the exploding carbon-oxygen white dwarfs (CO WDs) for producing type Ia supernovae (SNe Ia) are still not conclusively confirmed. A red-giant (RG) star has been suggested to be the mass donor of the exploding WD, named as the symbiotic channel. However, previous studies on the this channel gave a relatively low rate of SNe Ia. Aims. We aim to systematically investigate the parameter space, Galactic rates and delay time distributions of SNe Ia from the symbiotic channel by employing a revised mass-transfer prescription. Methods. We adopted an integrated mass-transfer prescription to calculate the mass-transfer process from a RG star onto the WD. In this prescription, the mass-transfer rate varies with the local material states. Results. We evolved a large number of WD+RG systems, and found that the parameter space of WD+RG systems for producing SNe Ia is significantly enlarged. This channel could produce SNe Ia with intermediate and old ages, contributing to at most 5% of all SNe Ia in the Galaxy. Our model increases the SN Ia rate from this channel by a factor of 5. We suggest that the symbiotic systems RS Oph and T CrB are strong candidates for the progenitors of SNe Ia.Comment: 8 pages, 6 figure

Regulation of the stability and transcriptional activity of NFATc4 by ubiquitination

AbstractNuclear factor of activated T cells (NFATc4) has been implicated as a critical regulator of the cardiac development and hypertrophy. However, the mechanisms for regulating NFATc4 stability and transactivation remain unclear. We showed that NFATc4 protein was predominantly ubiquitinated through the formation of Lysine 48-linked polyubiquitin chains, and this modification decreased NFATc4 protein levels and its transcriptional activity. Furthermore, activation of GSK3β markedly enhanced NFATc4 ubiquitination and decreased its transactivation, whereas inhibition of GSK3β had opposite effects. Importantly, ubiquitination and phosphorylation induced by GSK3β repressed NFATc4-dependent cardiac-specific gene expression. These results demonstrate that the ubiquitin–proteasome system plays an important role in regulating NFATc4 stability and transactivation.Structured summaryMINT-6798349:NFATc4 (uniprotkb:Q14934) physically interacts (MI:0218) with Ubiquitin (uniprotkb:P62988) by anti bait coimmunoprecipitation (MI:0006)MINT-6798334:NFATc4 (uniprotkb:Q14934) physically interacts (MI:0218) with Ubiquitin (uniprotkb:P62988) by anti tag coimmunoprecipitation (MI:0007)MINT-6798321:Ubiquitin (uniprotkb:P62988) physically interacts (MI:0218) with NFATc4 (uniprotkb:Q14934) by pull down (MI:0096

TNFα induces Ca2+ influx to accelerate extrinsic apoptosis in hepatocellular carcinoma cells

BACKGROUND: Tumor necrosis factor-α has been proven an effective anticancer agent in preclinical studies. However, the translation of TNFα from research to clinic has been blocked by significant systemic toxicity and limited efficacy at maximal tolerated dose, which need urgently to be solved. METHODS: The level of cytosolic Ca RESULTS: Here, we demonstrated that TNFα induced extracellular Ca CONCLUSIONS: Our study provides the evidence supporting a novel mechanism by which TNFα induces extracellular C

An animal model of SARS produced by infection of Macaca mulatta with SARS coronavirus.

A new SARS animal model was established by inoculating SARS coronavirus (SARS-CoV) into rhesus macaques (Macaca mulatta) through the nasal cavity. Pathological pulmonary changes were successively detected on days 5-60 after virus inoculation. All eight animals showed a transient fever 2-3 days after inoculation. Immunological, molecular biological, and pathological studies support the establishment of this SARS animal model. Firstly, SARS-CoV-specific IgGs were detected in the sera of macaques from 11 to 60 days after inoculation. Secondly, SARS-CoV RNA could be detected in pharyngeal swab samples using nested RT-PCR in all infected animals from 5 days after virus inoculation. Finally, histopathological changes of interstitial pneumonia were found in the lungs during the 60 days after viral inoculation: these changes were less marked at later time points, indicating that an active healing process together with resolution of an acute inflammatory response was taking place in these animals. This animal model should provide insight into the mechanisms of SARS-CoV-related pulmonary disease and greatly facilitate the development of vaccines and therapeutics against SARS

Responses of soil microbial communities to a short-term application of seaweed fertilizer revealed by deep amplicon sequencing

Numerous studies have reported soil damage from chemical fertilizer application and an obvious promotional effect of seaweed fertilizer fermented with Sargassum horneri on the growth of tomato roots and seedlings due to its alginate oligosaccharide. However, few studies have assessed the effects of the fermented seaweed fertilizer on ecological environment and microorganisms in soil. Herein, our objective is to uncover microbial and soil environmental responses to Sargassum horneri-fermented seaweed fertilizer. After treated tomato-planting plots with Sargassum horneri fermented seaweed fertilizer, soil bacterial community compositions based on 16S rRNA gene amplicon sequencing, enzyme activities in soil and crop yield were analyzed. The bacterial a-diversity was strongly influenced by seaweed fertilizer amendment after 60 days. Non-metric multidimensional scaling (NMDS) analysis showed that a difference in bacterial community compositions between day 0 and day 60 was obvious for soil treated with seaweed fertilizer. The community variation could be caused by invertase activity and dehydrogenase activity in canonical correlation analysis (CCA). Protease activity, polyphenol oxidase activity and urease activity showed an obvious correlation with community variation in the Mantel test. The fertilization increased tomato yield by 1.48-1.83 times, Vc content by 1.24-4.55 times and lycopene content by 1.20-2.33 times. In the present study, a possible reason for bacterial community variation was discovered, which will provide an economical dilution rate of seaweed fertilizer for optimal crop yield and quality. Meanwhile, our study will be beneficial for developing a possible substitute for chemical fertilizer and an improved understanding of soil microbial functions and soil sustainability

Modular Microfluidics: Current Status and Future Prospects

This review mainly studies the development status, limitations, and future directions of modular microfluidic systems. Microfluidic technology is an important tool platform for scientific research and plays an important role in various fields. With the continuous development of microfluidic applications, conventional monolithic microfluidic chips show more and more limitations. A modular microfluidic system is a system composed of interconnected, independent modular microfluidic chips, which are easy to use, highly customizable, and on-site deployable. In this paper, the current forms of modular microfluidic systems are classified and studied. The popular fabrication techniques for modular blocks, the major application scenarios of modular microfluidics, and the limitations of modular techniques are also discussed. Lastly, this review provides prospects for the future direction of modular microfluidic technologies

Effects of Raloxifene on the Proliferation and Apoptosis of Human Aortic Valve Interstitial Cells

We aimed to explore the effects of raloxifene (RAL) on the proliferation and apoptosis of human aortic valve interstitial cells (AVICs). Different concentrations of RAL were used to act on AVICs. MTS kit is used to test the effects of different concentrations of RAL on the proliferation of AVICs. Cell cycle and apoptosis test used flow cytometry after seven-day treatment. The relative expression levels of caspase-3 and caspase-8 are tested with RT-qPCR and Western blot. The results of MTS testing revealed that the absorbance value (OD value) of the cells in the concentration groups of 10 and 100 nmol/L RAL at a wavelength of 490 nm at five, seven, and nine days significantly decreased compared with that in the control group. Meanwhile, the results of flow cytometry of the cells collected after seven days showed that the ratio of the S stage and the cell apoptosis rate of AVICs can be significantly reduced by RAL in the concentration groups of 10 and 100 nmol/L. The mRNA and protein expressions of caspase-3 and caspase-8 were significantly decreased compared with those in the control group. This study laid the foundation for further treatment of aortic valve disease by using RAL

Measuring the Damping Performance of Gradient-Structured Bamboo Using the Resonance Method

Bamboo has natural damping properties, but, due to the obvious gradient differences in bamboo walls, the damping properties of different layers may vary. Using bamboo slivers as the research object, this study investigated the underlying mechanism of the effect of microstructural and chemical components on the damping properties (η, damping ratio) of bamboo using the resonance and nonresonance methods. The damping ratio decreased on L3 (inner layer), L2 (middle layer), and L1 (outer layer) due to lower microfibril angles, increased crystallinity of cellulose, and decreased hemicellulose content. All of these limited the motion of the bamboo’s molecular chains. The damping ratio successively increased in the oven-dried, air-dried, and water saturated states because water acted as a plasticizer. The damping ratio of L1, in the oven-dried state, was slightly higher than that of the air-dried state because L1 had the lowest water content. This allowed less water to escape during drying, which intensified the molecular distortion. The initial tan δ (tangent of the loss angle) decreased successively on the L3, L2, and L1 layers of the bamboo, and the tan δ of L3 was lower than that of L2 due to changes in the temperature sensitivity of hemicellulose

A Novel Classification Optimization Approach Integrating Class Adaptive MRF and Fuzzy Local Information for High Spatial Resolution Multispectral Imagery

This paper develops a novel classification optimization approach integrating class adaptive Markov Random Field (MRF) and fuzzy local information (CAMRF-FLI) for high spatial resolution multispectral imagery (HSRMI). Firstly, the raw classification results, including initial fuzzy memberships and class labels of every pixel, are achieved by a pixel-wise classification method for a given image. Secondly, the class adaptive MRF-based data energy function is developed to integrate class spatial dependency information. Thirdly, a novel spatial energy function integrating fuzzy local information is constructed. Finally, based on the total of data and spatial energies, the raw classification map is regularized by a global minimization of the energy function using its iterated conditional modes (ICM). The effectiveness of CAMRF-FLI is performed by two data sets. The results indicate it can refine the classification map in homogeneous areas, meanwhile, reduce most of the edge blurring artifact, and improve the classification accuracy compared with some conventional approaches

Measuring the Damping Performance of Gradient-Structured Bamboo Using the Resonance Method

Bamboo has natural damping properties, but, due to the obvious gradient differences in bamboo walls, the damping properties of different layers may vary. Using bamboo slivers as the research object, this study investigated the underlying mechanism of the effect of microstructural and chemical components on the damping properties (η, damping ratio) of bamboo using the resonance and nonresonance methods. The damping ratio decreased on L3 (inner layer), L2 (middle layer), and L1 (outer layer) due to lower microfibril angles, increased crystallinity of cellulose, and decreased hemicellulose content. All of these limited the motion of the bamboo’s molecular chains. The damping ratio successively increased in the oven-dried, air-dried, and water saturated states because water acted as a plasticizer. The damping ratio of L1, in the oven-dried state, was slightly higher than that of the air-dried state because L1 had the lowest water content. This allowed less water to escape during drying, which intensified the molecular distortion. The initial tan δ (tangent of the loss angle) decreased successively on the L3, L2, and L1 layers of the bamboo, and the tan δ of L3 was lower than that of L2 due to changes in the temperature sensitivity of hemicellulose