Porcine circovirus type 2 (PCV2), an economically important pathogen, causes postweaning multisystemic wasting syndrome (PMWS) and other syndrome diseases collectively known as porcine circovirus-associated disease (PCVAD). Previous studies revealed breed-dependent differences in porcine susceptibility to PCV2; however, the genetic mechanism underlying different resistance to PCV2 infection remains largely unknown. In this study, we found that Yorkshire × Landrace (YL) pigs exhibited serious clinical features typifying PCV2 disease, while the Laiwu (a Chinese indigenous pig breed, LW) pigs showed little clinical symptoms of the disease during PCV2 infection. At 35 days post infection (dpi), the PCV2 DNA copy in YL pigs was significantly higher than that in LW pigs (P < 0.05). The serum level of IL-4, IL-6, IL-8, IL-12 and TGF-β1 in LW pigs and TNF-α in YL pigs increased significantly at the early infected stages, respectively; while that of IL-10 and IFN-γ in YL pigs was greatly increased at 35 dpi. RNA-seq analysis revealed that, at 35 dpi, 83 genes were up-regulated and 86 genes were down-regulated in the lung tissues of LW pigs, while in YL pigs, the numbers were 187 and 18, respectively. In LW pigs, the differentially expressed genes (DEGs) were mainly involved in complement and coagulation cascades, metabolism of xenobiotics by cytochrome P450, RIG-I-like receptor signaling and B cell receptor signaling pathways. Four up-regulated genes (TFPI, SERPNC1, SERPNA1, and SERPNA5) that are enriched in complement and coagulation cascades pathway were identified in the PCV2-infected LW pigs, among which the mRNA expression of SERPNA1, as well as three genes including TGF-β1, TGF-β2 and VEGF that are regulated by SERPNA1 was significantly increased (P < 0.05). We speculate that higher expression of SERPNA1 may effectively suppress excessive inflammation reaction and reduce the pathological degree of lung tissue in PCV2-infected pigs. Collectively, our findings indicate that the susceptibility to PCV2 infection depends on a genetic difference between LW and YL pigs, and SERPNA1 likely plays an important role in the resistance of LW pigs to PCV2 infection.

Porcine circovirus type 2 (PCV2) is the primary cause of post-weaning multisystemic wasting syndrome (PMWS) and other PCV-associated diseases. According to our previous RNA-sequencing analysis, the differences in the susceptibility to PCV2 infection depended on the genetic differences between the Laiwu (LW) and Yorkshire × Landrace crossbred (YL) pigs, but the cellular microRNA (miRNA) that are differentially expressed between the LW and YL pigs before and after PCV2 infection remain to be determined. In this study, high-throughput sequencing was performed to determine the abundance and differential expression of miRNA in lung tissues from PCV2-infected and PCV2-uninfected LW and YL pigs. In total, 295 known and 95 novel miRNA were identified, and 23 known and 25 novel miRNA were significantly differentially expressed in the PCV2-infected vs. PCV2-uninfected LW pigs and/or the PCV2-infected vs. PCV2-uninfected YL pigs. The expression levels of ssc-miR-122, ssc-miR-192, ssc-miR-451, ssc-miR-486, and ssc-miR-504 were confirmed by quantitative real-time PCR (qRT-PCR). Analysis of the potential targets of the four up-regulated miRNA (i.e., ssc-miR-122, ssc-miR-192, ssc-miR-451 and ssc-miR-486) identified pathways and genes that may be important for disease resistance. Among the up-regulated miRNA, ssc-miR-122 can repress the protein expression and viral DNA replication of PCV2 and down-regulate the expression of the nuclear factor of activated T-cells 5 (NFAT5) and aminopeptidase puromycin sensitive (NPEPPS) by binding to their 3′ untranslated region (3′UTR) in PK15 cells. Therefore, ssc-miR-122 may indirectly suppress PCV2 infection by targeting genes related to the host immune system, such as NFAT5 and NPEPPS.Electronic supplementary materialThe online version of this article (10.1186/s13567-018-0512-3) contains supplementary material, which is available to authorized users.

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The iodine-sulfur thermochemical water-splitting cycle (I-S process) is one of the highly efficient, CO 2 -free, massive hydrogen production methods. We simulated the I-S process through commercial software programs Aspen Plus and OLI database with the aid of self-developed models to analyze the overall running status of the process and to decrease the investment and time consumption of experiments. A two-phase separator model operating at 353 K and an electroelectrodialysis (EED) cell model working at 338 K were built on the basis of experimental data. The entire flow sheet of the I-S process was modeled based on the two self-developed models. The simulation models were validated through the experimental results obtained from the closed cycle I-S facility (IS-10) in our laboratory. By employing the simulation program, sensitivity analyses of the important parameters in the process were carried out, including the ratio of the distillate to the feed rate of the H 2 SO 4 distillation column, reflux ratio of the H 2 SO 4 column, H 2 SO 4 conversion ratio, HI molality in the EED cathode outlet stream, and HI mole fraction in the liquid and vapor distillates of the HI distillation column. The key parameters significantly affecting the input duty were determined; that is, the ratio of the distillate to the feed rate of the H 2 SO 4 distillation column and the HI molality in the EED cathode outlet stream. The optimal values of the analyzed parameters were also discussed. The simulation program we developed is a useful tool that can evaluate and optimize the I-S process.

With the advance of new exploration and production technologies, oil and gas production has gone to deeper and tighter formation than ever before. These developments have also brought challenges in scale prediction and inhibition, such as how to prevent scales at high temperature (150-200ºC), pressure (1,000-1,500 bars) and TDS (>300,000 mg/L) commonly experienced at these depths. This paper will discuss (1) the challenges of scale prediction at high temperature, pressure, and TDS; (2) an efficient method to study the nucleation kinetics of scale formation and inhibition at these conditions; (3) the kinetics of barite crystal nucleation and precipitation in the presence of various scale inhibitors and the effectiveness of those inhibitors. In this study, nine scale inhibitors have been evaluated at 70-200ºC to determine if they can successfully prevent barite precipitation. The results show that only a few inhibitors can effectively inhibit barite formation at 200ºC. Although it is commonly believed that phosphonate scale inhibitors may not work for high temperature inhibition applications, the results from this study suggest barite scale inhibition by phosphonate inhibitors was not impaired at 200°C under strictly anoxic condition and in NaCl brine. However, phosphonate inhibitors can precipitate with Ca 2+ in a brine at high temperatures and, hence, reduce efficiency. In addition, the relationship of scale inhibition to types of inhibitors and temperature are explored in this study.