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Objectives: Ningxia Hui Autonomous Region, an important area for ethnic Hui settlement in Northwest China, is a low HIV prevalence region. However, HIV infection rates among men who have sex with men (MSM) in Ningxia have increased to an alarming level, despite scale-up of control measures in recent years. This study aimed to understand the demographical and sexual behavior dy-namics of MSM and to explore the factors associated with HIV infection. Methods: Annual cross-sectional surveys were carried out among MSM during 2011~2017 in Yin-chuan, the capital city of Ningxia. Information regarding social demographics, sexual behavior and HIV prevention knowledge was collected. Blood samples were taken for HIV, HCV serological and genetic analysis, and syphilis serological analysis. The dynamic trend was analyzed with trend χ2 test and factors associated with HIV infection were identified by multivariate logistic regression analysis. Results: The study found a decreasing trend for mean age of the MSM population over the study peri-od. MSMs with a college education or higher increased significantly, while the proportions that were in a marriage significantly decreased over the study period. The rate of HIV positive among MSM in-creased during the study period (p

In this paper, we consider the dividend problem in a two-state Markov-modulated dual risk model, in which the gain arrivals, gain sizes and expenses are influenced by a Markov process. A system of integro-differential equations for the expected value of the discounted dividends until ruin is derived. In the case of exponential gain sizes, the equations are solved and the best barrier is obtained via numerical example. Finally, using numerical example, we compare the best barrier and the expected discounted dividends in the two-state Markov-modulated dual risk model with those in an associated averaged compound Poisson risk model. Numerical results suggest that one could use the results of the associated averaged compound Poisson risk model to approximate those for the two-state Markov-modulated dual risk model.

In this paper, we propose a customer-based individual risk model, in which potential claims by customers are described as i.i.d. heavy-tailed random variables, but different insurance policy holders are allowed to have different probabilities to make actual claims. Some precise large deviation results for the prospective-loss process are derived under certain mild assumptions, with emphasis on the case of heavy-tailed distribution function class ERV (extended regular variation). Lundberg type limiting results on the finite time ruin probabilities are also investigated.

To identify the serotype of 73 non-polio enterovirus (NPEV) strains from acute flaccid paralysis (AFP) cases in Ningxia province, during 1997 - 2011.Partial sequencing of the VP1 region was amplified by RT-PCR with degenerate primers and sequenced while sequences were compared with the database of GenBank by the BLAST algorithm. Evolution was analyzed by constructing phylogenetic tree using Mega 5.1.In this study, a total of 73 NPEVs were analyzed, including 4 strains un-typed, 69 strains typed by RT-PCR. A total of 27 serotypes were identified, including 8 serotypes of human enterovirus (HEV)-A, 19 serotypes of HEV-B. The HEV-B group (46/69, 66.7%) constituted the largest proportion of isolates, followed by HEV-A (23/69, 33.3%), but no strains were found that belonged to HEV-C or HEV-D group. In the 69 strains, enterovirus 71 was the most frequently seen isolates, followed by coxsackie-virus A4, 16, 9 and echovirus 24, 6.HEV-B was the most predominant (46/69, 66.7%) serotype of NPEV in Ningxia during the AFP surveillance, in 1997 - 2011.

To study the genetic characterization of coxsackievirus A16 (CVA16) strains isolated during an epidemic of hand, foot, and mouth disease (HFMD) in Ningxia Hui Municipality in 2008.Clinical samples were collected from HFMD patients in Ningxia Hui Municipality and CVA16 strains were isolated by viral isolation methods. Reverse transcription-polymerase chain reactions (RT-PCR), specific for CVA16 were performed with these CVA16 strains. Entire VP1 coding region amplification and sequencing were then performed and finally phylogenetic tree was constructed among Ningxia CVA16 strains and CVA16 representative strains of known genotypes and subgenotypes.70 Ningxia CVA16 strains were isolated from HFMD patients in Ningxia in 2008 and the homology of nucleotide and amino acid were 90.8%-100.0% and 98.9% - 100.0%, respectively. Phylogenetic characteristics of the strains reconfirmed that they could be divided into two distinct genotypes-A and B. Genotype B could be further divided into the subgenotypes B1 and B2, while all the 70 Ningxia CVA16 strains belonged to the co-circulated clusters B1a and B1b within subgenotype B1, which belonged to 2 viral transmission chains.Our results indicated that subgenotype B1 CVA16 strains continued to circulate over a wide geographic area of mainland China since the first reported episode in Shenzhen city in 1999. Like other CVA16 strains isolated elsewhere in China, both B1a and B1b evolution branches were co-circulating in Ningxia Hui Municipality. Based on the close phylgenetic and chronological relationship with CVA16 isolated in other countries and regions near China. Our data confirmed that these strains co-evolved and co-circulated with those from neighboring countries and regions.

To study the genetic characterization of enterovirus 71 (EV71) strains isolated from specimens of patients with hand-foot-mouth disease (HFMD) in Ningxia province in 2008.All the stool, throat swab and vesicle samples that collected from patients with HFMD were cultured. The positive isolates were identified by reverse transcriptase PCR (RT-PCR) with specific primers of EV71. Complete VP1 gene sequences (891 nucleotides) of 29 strains (part of 93 EV71 strains) were determined and compared with A, B and C genotype reference EV71 strains while EV71 China isolates by homogeneity and phylogenetic tree analyses.215 strains of EV were isolated from 439 specimens. Results from RT-PCR indicated that 93 strains belong to EV71. Phylogenetic tree analysis revealed that the selected 29 stains were clustered with reference strains of C4 subgenotype. The nucleotide identity with C4 reference strains was 91.7%-99.4%. The amino acid homogeneity was 96.6%-100.0%.The recently identified EV71 strains in Ningxia province belonged to subgenotype C4 which resembled to most of the isolates in China.

To study the chemical constituents in the active parts of Huoxue Yiqi Tang.The silica gel, Sephadex LH-20 were used to isolate the compounds, El, FAB-MS and 1D, 2D-NMR were used to identify the obtained compounds.14 compounds were obtained from the prescription.They were all first time obtained from the prescription. Among them, 7, 3'-dihydroxyl-5'-methoxyisoflavone is new.

To isolate and identify compounds from Picria fel-tarrae in order to utilize it better.Constituents from Picria fel-tarrae were isolated by several column chromatography and their structures were elucidated on the basis of chemical and spectral analysis.Six compounds, N-benzoylphenylalanyl-L-phenylalaninol acetate (1), 1-hydroxy-7-hydroxymethyl-9,10-anthraquinone (2), 9, 16-dioxo-10,12,14-octadeca-trienoic acid (3), 5,7,4'-trihydroxy-flavone (4), beta-sitosterol (5), and daucosterol (6) were obtained from the fraction with relatively low polarity of EtOH extract of Picria fel-tarrae.Compounds 1-6 were isolated from picria fel-tarrae Lour for the first time, and the 13C-NMR data of compounds 1-3 are provided firstly in the literature.

To study compounds isolated from Picria fel-terrae.The chemical constituents were separated and purified by column chromatography on silica gel and MCI. Their structures were identified on the basis of spectral data (IR, UV, MS, ID NMR and 2D NMR).A new cucurbitacin, along with a known one, were obtained from the 60% EtOH extract of the whole plant.The new compound was identified as 11, 24-dioxo-5, 21-diene-cucurbit-3alpha-O-beta-D-xylopyranosyl-16alpha-O-alpha-L-rhamnopyranoside (dehydrobryogenin glycoside). The known one, hexanorcucurbitacin F, was obtained for the first time from Picria fel-terrae.