catena-Poly[[(2,2'-bipyridine-κN,N')cadmium]-µ(3)-4-nitro-phthalato-κO:O',O'':O'''].

In the title polymeric compound, [Cd(C(8)H(3)NO(6))(C(10)H(8)N(2))](n), two O atoms from both carboxyl-ate groups of a nitro-phthalate anion coordinate to the Cd(II) cation, forming a seven-membered chelate ring and two carboxyl-ate O atoms from another two nitro-phthalate anions and a 2,2'-bipyridine ligand coordinate to the Cd cation to complete the distorted octa-hedral coordination geometry. The carboxyl-ate groups of the nitro-phthalate anion adopt a syn-anti bridging mode, linking adjacent Cd(II) cations and forming a polymeric chain running along the a axis. Weak intra- and inter-molecular C-H⋯O hydrogen bonding is present in the crystal structure.

Stability of filament-wound hyperbolic flexible pipes under internal pressure based on non-geodesic winding.

Filament-wound flexible pipes are widely used to transport fluid in pipeline systems, proved extremely useful in marine engineering. The hyperbolic flexible pipes have good vibration suppression performance, but they are easily deformed under internal pressure. This paper focuses on the stability of hyperbolic flexible pipes based on the composite Reissner shell theory and the transfer-matrix method. The nonlinear stretch of the reinforced filament and the fiber bridge effect are considered in the model. The calculation results show that a large winding angle reduces the deformation and the meridional stress. The available initial winding angle is limited by the geometry and the slippage coefficient of flexible pipe. The reinforced filament of high tensile modulus will reduce the deformation of the pipe. Compared with the geodesic winding trajectory, non-geodesic winding trajectories improves the stability of the pipe. The theoretical result is verified by the finite element analysis. The investigation method and results present in this paper will guide the design and optimization of more novel flexible pipes in the future.

[Effects of Chitosan-modified Biochar on Formation of Methylmercury in Paddy Soils and Its Accumulation in Rice].

Rice is well known to accumulate methylmercury (MeHg) and the consumption of rice in mercury (Hg) polluted areas has been confirmed to be a primary source of MeHg exposure. Therefore, how to inhibit the formation and accumulation of MeHg in the paddy field system needs to be solved urgently. Chitosan modified biochar, a potential inhibitor, was selected in this study to explore its effect on MeHg production and accumulation in the paddy field system by analyzing the mercury content of interstitial water, soil, and rice plant tissues. The results showed that the addition of chitosan modified biochar could significantly reduce MeHg concentration in the soil with the decreased methylation rate of 51.1%-79.1%, and could also decrease the total mercury (THg) and MeHg content of interstitial water. At the maturation stage of rice, the MeHg content of rice roots treated with chitosan modified biochar (CMBC) was 73.1% lower than without biochar (CK1) and 62.0% lower than with unmodified biochar (CK2), and the rice MeHg was 75.8% lower than that of CK1 and 72.9% lower than that of CK2. In addition, the application of biochar could promote the growth of rice with the plant biomass of CMBC and CK2 of 1.6 and 1.7 times higher than that of CK1. Generally, the application of chitosan modified biochar into paddy soil could not only promote the growth of rice, but also inhibit the accumulation of MeHg in rice, suggesting that the chitosan modified biochar has a certain application value in the inhibition of the MeHg formation and accumulation in paddy field system.

Anti-inflammatory mechanism of total glycosides of Acanthopanax Giraldii.

OBJECTIVE: To study the anti-inflammatory mechanisms of total glycosides of Acanthopanax Giraldii (TGA). METHODS: The changes of prostaglandin E(2)(PGE(2)), tumor necrosis factor (TNF-alpha), nitric oxide (NO), and expressions of COX-1 mRNA and COX-2 mRNA in BALB/c mouse macrophages were observed by the radioimmunoassay, ELISA and nitric acid reduction and RT-PCR in the presence or absence of TGA. RESULTS: (1) TGA could significantly decrease the production of PGE(2)and NO in mouse peritoneal macrophages. The inhibitory rate to LPS-induced PGE(2)production was 87% (TGA 100 mg/L, P<0.05, vs. LPS) and 62% (TGA 20 mg/L, P<0.05, vs. LPS), respectively. The inhibitory rate of NO production in mouse peritoneal macrophages was 49% (TGA 100 mg/L, P<0.05, vs. LPS) and 21% (TGA 20 mg/L, P<0.05 vs. LPS), respectively. TGA could not inhibit LPS-induced TNF-alpha production in mouse peritoneal macrophages. (2) TGA also inhibited the expression of COX-1 and COX-2 mRNA in RAW264.7 cells. The inhibitory rate of TGA to COX-1 mRNA was 22% (TGA 100 mg/L, P<0.05, vs. blank). The inhibitory rate of TGA to COX-2 mRNA was 55% (TGA 20 mg/L, P<0.05, vs. LPS) and 100% (TGA 100 mg/L, P<0.01 vs. LPS), respectively. CONCLUSION: The anti-inflammatory mechanisms of TGA for inhibiting the production of NO and PGE(2)are through inhibiting COX-2 mRNA expression without TNF-alpha changes.

Diverse genome structures of Salmonella paratyphi C.

BACKGROUND: Salmonella paratyphi C, like S. typhi, is adapted to humans and causes typhoid fever. Previously we reported different genome structures between two strains of S. paratyphi C, which suggests that S. paratyphi C might have a plastic genome (large DNA segments being organized in different orders or orientations on the genome). As many but not all host-adapted Salmonella pathogens have large genomic insertions as well as the supposedly resultant genomic rearrangements, bacterial genome plasticity presents an extraordinary evolutionary phenomenon. Events contributing to genomic plasticity, especially large insertions, may be associated with the formation of particular Salmonella pathogens. RESULTS: We constructed a high resolution genome map in S. paratyphi C strain RKS4594 and located four insertions totaling 176 kb (including the 90 kb SPI7) and seven deletions totaling 165 kb relative to S. typhimurium LT2. Two rearrangements were revealed, including an inversion of 1602 kb covering the ter region and the translocation of the 43 kb I-CeuI F fragment. The 23 wild type strains analyzed in this study exhibited diverse genome structures, mostly as a result of recombination between rrn genes. In at least two cases, the rearrangements involved recombination between genomic sites other than the rrn genes, possibly homologous genes in prophages. Two strains had a 20 kb deletion between rrlA and rrlB, which is a highly conservative region and no deletion has been reported in this region in any other Salmonella lineages. CONCLUSION: S. paratyphi C has diverse genome structures among different isolates, possibly as a result of large genomic insertions, e.g., SPI7. Although the Salmonella typhoid agents may not be more closely related among them than each of them to other Salmonella lineages, they may have evolved in similar ways, i.e., acquiring typhoid-associated genes followed by genome structure rearrangements. Comparison of multiple Salmonella typhoid agents at both single sequenced genome and population levels will facilitate the studies on the evolutionary process of typhoid pathogenesis, especially the identification of typhoid-associated genes.

Spontaneous conversion between mutL and 6 bpDeltamutL in Salmonella typhimurium LT7: association with genome diversification and possible roles in bacterial adaptation.

Previously, we reported the phenomenon of genome diversification in Salmonella typhimurium LT7, i.e., individual strains derived from LT7 kept changing the genome structure by inversions, translocations, duplications, and mutations. To elucidate the genetic basis, we sequenced selected genes of the mismatch repair (MMR) system for correlations between MMR defects and genome diversification. We chose S. typhimurium LT7 mutants 8111F2 and 9052D1 for mut gene sequence analyses and found that both mutants had a deletion of one of three tandem 6-bp repeats, GCTGGC GCTGGC GCTGGC, within mutL, which was designated 6 bpDeltamutL. mutS and mutH genes were unchanged in the mutants analyzed. Some sublines of 8111F2 and 9052D1 spontaneously stopped the genome diversification process at certain stages during single-colony restreaking passages, and in these strains the 6 bpDeltamutL genotype also became wild-type mutL. We conclude that conversion between mutL and 6 bpDeltamutL occurs spontaneously and that transient defects of mutL facilitate genome diversification without leading to the accumulation of multiple detrimental genetic changes. Spontaneous conversion between mutL and 6 bpDeltamutL may be an important mechanism used by bacteria to regulate genetic stability in adaptation to changing environments.

[Study on Jisi Yi'an (Medical Cases of Multitude Thought) of Yi Jusun, a famous doctor of Lingnan region].

Textual research was made on Jisi Yián (Medical Cases of Multitude Thought), a book of medical cases written by Yi Jusun, whose nickname is Chubai, one of the "Four Warriors of Buddha", modern four heads school in favor of classical prescriptions in Lingnan region. The now extant hand- written copy of this medical book is collected in the Shu Renzhi's Juxiang Hall in the early period of Republic of China. Analyses are made on the medical records of treating difficult and critical illness applied by Yi Jusun. The Shengma Biejia San (skunk bugbane and Carapax Amydae Powder) proposed by him played a vital role in preventing and curing plague in modern Guangdong Province.