174 research outputs found
Structural Properties of Liquid SiC during Rapid Solidification
The rapid solidification of liquid silicon carbide (SiC) is studied by molecular dynamic simulation using the Tersoff potential. The structural properties of liquid and amorphous SiC are analyzed by the radial distribution function, angular distribution function, coordination number, and visualization technology. Results show that both heteronuclear and homonuclear bonds exist and no atomic segregation occurs during solidification. The bond angles of silicon and carbon atoms are distributed at around 109° and 120°, respectively, and the average coordination number is <4. Threefold carbon atoms and fourfold silicon atoms are linked together by six typical structures and ultimately form a random network of amorphous structure. The simulated results help understand the structural properties of liquid and amorphous SiC, as well as other similar semiconductor alloys
Relationship between four tumor-associated bio-markers and prognosis of gastric cancer
Purpose: To investigate the relationship between prognosis of gastric cancer (GC) and the expression of P53, Epidermal growth factor receptor (EGFR), Human epidermal growth factor receptor-2 (HER-2), and Vascular endothelial growth factor (VEGF).Methods: One hundred and forty-seven patients admitted to People's Liberation Army General Hospital (Beijing, China) with diagnosis of locally advanced GC were enrolled in the study. Follow-up data were obtained by outpatient review or telephone follow-up. Expressions of P53, EGFR, HER-2 and VEGF were determined by immunohistochemical staining. The relationship between protein expression, clinico-pathological factors, disease-free survival time (DFS) and overall survival (OS) were analyzed.Results: The expressions of EGER, HER-2, P53 and VEGF in GC were 17.7, 17.0, 41.0 and 55.9%, respectively. The expressions of EGFR and P53 were positively correlated (r = 0.306, p < 0.05), while the expressions of VEGF and HER-2 were negatively correlated (r = -0.2, p < 0.05). The expressions of EGFR, HER-2 and VEGF were not related to the clinico-pathological factors (p > 0.05) while expression of P53 was related only to histological grade (p < 0.05). Univariate analysis showed that OS and DFS were longer (p < 0.05) when P53 was lowly expressed. Multiple-factor analysis revealed that histological grade, infiltration depth and P53 expression were independent factors that influenced DFS.Conclusion: These results indicate that the expression of P53, EGFR, HER2 and VEGF can be used to predict prognosis of GC and screening of patients’ benefits from adjuvant chemotherapy.Keywords: Gastric cancer, Prognosis, Biomarkers, Adjuvant chemotherap
Rapid FRD determination for multiplexed fibre systems -- I. The quasi-near field model and its uncertainties
Focal Ratio Degradation (FRD) in fibres is a crucial factor to control in
astronomical instruments in order to minimize light loss. As astronomical
instrumentation has advanced, the integration of large populations of fibres
has become common. However, determining FRD in multiplexed fibre systems has
become a challenging and time-consuming task. The Integral Field Unit for the
Fiber Arrayed Solar Optical Telescope (FASOT-IFU) represents the most densely
arranged fibre-based IFU in a single unit. Due to the close packing of fibres
in the V-groove of the slit end, measuring FRD is particularly challenging as
the output spots are prone to overlapping with adjacent fibres. In this paper,
a novel method based on the quasi-near field model is proposed to enable rapid
FRD measurement in highly multiplexed fibre systems like IFUs and multi-object
observation systems. The principle and uncertainties associated with the method
are investigated. The method's validity is demonstrated by applying it to
determine the FRD in FASOT-IFU, with the achieved FRD performance meeting the
acceptable requirements of FASOT-IFU, where the output focal ratio primarily
falls within the range of 5.0-7.0. The results indicate that the proposed
method offers several advantages, including the simultaneous and rapid
measurement of FRD in multiple fibres with high accuracy (error smaller than
0.35 in F-ratio). Furthermore, besides FRD, the method exhibits potential for
extensive measurements of throughput, scrambling, and spectral analysis.Comment: 10 pages, 12 figures, submitted to MNRA
High-quality genome assembly and comparative genomic profiling of yellowhorn (Xanthoceras sorbifolia) revealed environmental adaptation footprints and seed oil contents variations
Yellowhorn (Xanthoceras sorbifolia) is a species of deciduous tree that is native to Northern and Central China, including Loess Plateau. The yellowhorn tree is a hardy plant, tolerating a wide range of growing conditions, and is often grown for ornamental purposes in parks, gardens, and other landscaped areas. The seeds of yellowhorn are edible and contain rich oil and fatty acid contents, making it an ideal plant for oil production. However, the mechanism of its ability to adapt to extreme environments and the genetic basis of oil synthesis remains to be elucidated. In this study, we reported a high-quality and near gap-less yellowhorn genome assembly, containing the highest genome continuity with a contig N50 of 32.5 Mb. Comparative genomics analysis showed that 1,237 and 231 gene families under expansion and the yellowhorn-specific gene family NB-ARC were enriched in photosynthesis and root cap development, which may contribute to the environmental adaption and abiotic stress resistance of yellowhorn. A 3-ketoacyl-CoA thiolase (KAT) gene (Xso_LG02_00600) was identified under positive selection, which may be associated with variations of seed oil content among different yellowhorn cultivars. This study provided insights into environmental adaptation and seed oil content variations of yellowhorn to accelerate its genetic improvement
Copied goods and the informal economy in Brazil and China: outlining a comparison of development models
- …