587 research outputs found
RBX1/ROC1-SCF E3 ubiquitin ligase is required for mouse embryogenesis and cancer cell survival
RBX1 (also known as ROC1) is a RING subunit of SCF (Skp1, Cullins, F-box proteins) E3 ubiquitin ligases, required for SCF to direct a timely degradation of diverse substrates, thereby regulating numerous cellular processes under both physiological and pathological conditions. Previous studies have shown that RBX1 is essential for growth in yeast, Caenorhabditis elegans and Drosophila. The role of RBX1 in mouse development and in regulation of cancer cell survival was unknown. Our recent work demonstrated that RBX1 is an essential gene for mouse embryogenesis, and targeted disruption of RBX1 causes embryonic lethality at E7.5 due to hypoproliferation as a result of p27 accumulation. We also showed that RBX1 is overexpressed in a number of human cancers, and siRNA silencing of RBX1 caused cancer cell death as a result of sequential induction of G2-M arrest, senescence and apoptosis. These findings reveal a physiological role of RBX1 during mouse development and a pathological role for the survival of human cancer cells. Differential outcomes between normal (growth arrest) and cancer cells (cell death) upon RBX1 disruption/silencing suggest RBX1 as a valid anticancer target
The Evolution of Measurement Methods of Comparative Advantage and New Trends in IntraProduct International Specialization
In the development and the evolution of international trade theory, comparative advantage has always been a core concept. A great deal of research pertains to the calculation methods of comparative advantage. However, most previous research on measurement methods of comparative advantage is mainly based on a country's import/export volume of a specific industry or product. Under the circumstances of contemporary intra-product international specialization, previous measurement methods are not appropriate. It is imperative to improve original measure methods of comparative advantage through stripping overseas contents of exports, and putting forward a new measurement index reflecting the domestic contents of export
The spin measurement of MAXI J1348-630 using the Insight-HXMT data
We report the results of fitting Insight-HXMT data to the black hole X-ray
binary MAXI J1348-430, which was discovered on January 26th, 2019, with the Gas
Slit Camera (GSC) on-board MAXI. Several observations at the beginning of the
first burst were selected, with a total of 10 spectra. From the residuals of
fits using disk plus power law models, X-ray reflection signatures were clearly
visible in some of these observations. We use the state-of the-art relxill
series reflection model to fit six spectra with distinct reflection signatures
and a joint fit to these spectra. In particular, we focus on the results for
the black hole spin values. Assuming Rin = RISCO, the spin parameter is
constrained to be 0.82+0.04-0.03 with 90% confidence level (statistical only).Comment: Revisions to MNRAS are submitted, and comments are welcome
Study on candidate gene for fecundity traits in Xingjiang Cele black sheep
The aim of the present study is to find a potential candidate gene for high fecundity in Cele black sheep. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology was used to detect single nuclear polymorphism (SNP) of four candidate genes (BMPR-IB, BMP15, GDF9, and ESRα) in Cele black sheep. The results showed that (i) A-G mutation was found at 746 bp in BMPR-IB in which the frequencies of homozygote (BB), heterozygote (B+) and wild type (++) were 0.113, 0.471, and 0.416, respectively. Significant differences were observed in litter size between ++ and B+ (P < 0.01) and between ++ and BB of individuals (P < 0.05). (ii) C-G mutation was found at exon 1 of ESRα in which the frequencies of homozygote, heterozygote and wild type were 0.047, 0.321 and 0.631, respectively. No significant difference was observed in litter size among the genotypes of ESRα (P > 0.05). (iii) No polymorphism was found in four mutation sites (FecXG, FecXB, FecXI, FecXH) of BMP15 and in one mutation site (FecGH) of GDF9 gene. The results indicate that fecundity characteristic was positively correlated to BMPR-IB. However, there was no relation between fecundity characteristic and detected SNP sites of ESRα, BMP15 and GDF9 genes. These preliminary results showed that the BMPR-IB gene is either a major gene that influences the prolificacy in Cele black sheep or a molecular genetic marker in close linkage with such a gene.Key words: Cele black sheep, fecundity candidate gene, BMPR-IB, BMP15, GDF9, ESRα
The Spin of New Black Hole Candidate: MAXI J1803-298 Observed by NuSTAR and NICER
MAXI J1803-298, a newly-discovered Galactic transient and black hole
candidate, was first detected by \emph{MAXI}/GSC on May 1st, 2021. In this
paper, we present a detailed spectral analysis of MAXI J1803-298. Utilizing the
X-ray reflection fitting method, we perform a joint fit to the spectra of MAXI
J1803-298, respectively, observed by \emph{NuSTAR} and \emph{NICER}/XTI on the
same day over the energy range between 0.7-79.0 keV, and found its spin (and
the inclination angle i) can be constrained to be close to an extreme value,
0.991 ( ), at 68\% confidence interval. The results suggest
that MAXI J1803-298 may be a fast-rotating black hole with a large inclination
angle.Comment: 6 pages, 5 figure
Comparative Study of the Amount of Re-released Hemoglobin from α-Thalassemia and Hereditary Spherocytosis Erythrocytes
Hemoglobin release test (HRT), which is established by our lab, is a new experiment to observe the re-released hemoglobin (Hb) from erythrocytes. In this study, one-dimension HRT, double dimension HRT, and isotonic and hypotonic HRT were performed to observe the re-released Hb from the blood samples of normal adult, hereditary spherocytosis (HS), and α-thalassemia. The results showed that compared with normal adult, the re-released Hb from HS blood sample was decreased significantly; however, the re-released Hb from α-thalassemia blood sample was increased significantly. The mechanism of this phenomenon was speculated to have relation with the abnormal amount of membrane-binding Hb
NUMERICAL ANALYSIS OF VALVE STRUCTURE OF HIGH POWER MARINE ENGINE
Valve as an important part of the gas distribution mechanism, is an crucial part of the engine. When the engine works, the valve is subjected to high temperature, high impact, frictional wear and corrosion and other harsh working conditions, and the reliable and durable valve has an important impact on the safety and reliability of the engine. In this paper, a model of four-stroke marine diesel engine valve is used as the research object, and the intake valve set and exhaust valve set models are established respectively. Heat transfer simulation and failure analysis of inlet and exhaust valves of different structures and materials under different operating conditions were carried out using finite element analysis. The results show that the different valve structures and manufacturing materials have different effects on the reliability of the valves; Changing the valve structures and choosing different valve manufacturing materials have a greater impact on the heat transfer and deformation, thus affecting the overall reliability of the valves
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