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• Several algorithms of solving sparse matrix are studied, including EDAGS, FSNZ etc. • ODFZ algorithm is proposed to improve the speed of solving depletion sparse matrix. • ODFZ has higher calculation accuracy and efficiency. Depletion solver with Chebyshev rational approximation method (DESCAR) was developed by Nuclear Power Institute of China (NPIC) to solve depletion equation. In this paper, the algorithms for solving depletion sparse matrix are studied, including symbolic Lower-Triangle and Upper-Triangle (LU) decomposition using elimination directed acyclic graphs (EDAGS), symbolic LU decomposition using symmetric reduction (FSNZ), symbolic LU decomposition using partial path-symmetric reduction (FPNZ), symbolic decomposition using elimination tree (ETREE), the direct sparse solver using pardiso routine in Intel math kernel library (PDMKL). An optimized direct factorization algorithm (ODFZ) is proposed to improve the speed of solving sparse matrix. The above methods are developed and tested in DESCAR module using a 17 × 17 pressurized water reactor (PWR) assembly containing Gd 2 O 3 -UO 2 fuel rods. Results show that ODFZ method has highest calculation efficiency, the calculation speed is about 3.5 times that of PDMKL method. [ABSTRACT FROM AUTHOR]

Background: In recent years novel human respiratory disease agents have been described for Southeast Asia and Australia. The causative pathogens were classified as pteropine orthoreoviruses with a strong phylogenetic relationship to orthoreoviruses of bat origin., Results: In this report, we isolated a novel Melaka-like reovirus (named "Cangyuan virus") from intestinal content samples of one fruit bat residing in China's Yunnan province. Phylogenetic analysis of the whole Cangyuan virus genome sequences of segments L, M and S demonstrated the genetic diversity of the Cangyuan virus. In contrast to the L and M segments, the phylogenetic trees for the S segments of Cangyuan virus demonstrated a greater degree of heterogeneity., Conclusions: Phylogenetic analysis indicated that the Cangyuan virus was a novel orthoreovirus and substantially different from currently known members of Pteropine orthoreovirus (PRV) species group.

Background: The identification of new virus strains is important for the study of infectious disease, but current (or existing) molecular biology methods are limited since the target sequence must be known to design genome-specific PCR primers. Thus, we developed a new method for the discovery of unknown viruses based on the cDNA--random amplified polymorphic DNA (cDNA-RAPD) technique. Getah virus, belonging to the family Togaviridae in the genus Alphavirus, is a mosquito-borne enveloped RNA virus that was identified using the Virus-Discovery-cDNA RAPD (VIDISCR) method., Results: A novel Getah virus was identified by VIDISCR from suckling mice exposed to mosquitoes (Aedes albopictus) collected in Yunnan Province, China. The non-structural protein gene, nsP3, the structural protein gene, the capsid protein gene, and the 3'-untranslated region (UTR) of the novel Getah virus isolate were cloned and sequenced. Nucleotide sequence identities of each gene were determined to be 97.1-99.3%, 94.9-99.4%, and 93.6-99.9%, respectively, when compared with the genomes of 10 other representative strains of Getah virus., Conclusions: The VIDISCR method was able to identify known virus isolates and a novel isolate of Getah virus from infected mice. Phylogenetic analysis indicated that the YN08 isolate was more closely related to the Hebei HB0234 strain than the YN0540 strain, and more genetically distinct from the MM2021 Malaysia primitive strain.