Pseudorabies gD protein protects mice and piglets against lethal doses of pseudorabies virus

IntroductionPseudorabies (PR) is a highly contagious viral disease caused by the pseudorabies virus (PRV), which can cause disease in a wide range of domestic and wild animals. Studies have shown that new mutant strains have emerged in pig farms in many regions and that commercial inactivated and live attenuated vaccines are becoming less effective at protecting pigs.MethodsPorcine pseudorabies glycoprotein D (gD) gene (GenBank: QEY95774.1) with hexa-His tag to the C terminus for further purification processes was cloned into the lentiviral expression plasmid pLV-CMV-eGFP by restriction enzyme, the resulting plasmid was designated as pLV-CMV-gD. HEK-293T cells with robust and stable expression of recombinant gD protein was established by infection with recombinant lentivirus vector pLV-CMV-gD. We expressed porcine pseudorabies virus gD protein using HEK-293T cells.ResultsWe describe in this study that individual gD proteins produced by a mammalian cell expression system are well immunogenic and stimulate high levels of PRV-specific and neutralizing antibodies in mice and piglets. All mice and piglets survived lethal doses of PRV, significantly reducing the amount of PRV virus in piglets’ lymph nodes, lungs, spleen, and other tissues. It also significantly reduced the time cycle and amount of viral excretion from piglets to the environment through the nasal and anal cavities.DiscussionThe results suggest that PRV gD protein is expected to be a potential candidate for the preparation of genetically engineered PR vaccines for the prevention of PRV infection and the control of PR epidemics

Characterization of monoclonal antibodies that specifically differentiate field isolates from vaccine strains of classical swine fever virus

Classical swine fever virus (CSFV) is a major animal pathogen threatening the global pork industry. To date, numerous anti-CSFV monoclonal antibodies (mAbs) and their recognizing epitopes have been reported. However, few mAbs were systematically characterized for the capacity to differentiate field CSFV isolates from CSF vaccine strains, and the molecular basis associated with antigenic differences between vaccines and field isolates is still largely unknown. In the present study, recombinant CSFV structural glycoproteins E2 of both virulent and vaccine strains and Erns of vaccine strain were expressed using eukaryotic cells and murine mAbs generated against E2 and Erns. After serial screening and cloning of the hybridomas, the viral spectra of mAbs were respectively determined by indirect fluorescent antibody assay (IFA) using 108 CSFVs, followed by Western blot analysis using expressed glycoproteins of all CSFV sub-genotypes including vaccine strains. The antigenic structures recognized by these mAbs were characterized by epitope mapping using truncated, chimeric, and site-directed mutated E2 and Erns proteins. We have identified two vaccine-specific, one field isolate-specific, and two universal CSFV-specific mAbs and five novel conformational epitopes with critical amino acid (aa) motifs that are associated with these five mAbs: 213EPD215, 271RXGP274, and 37LXLNDG42 on E2 and 38CKGVP42, W81, and D100/V107 on Erns. Particularly, E213 of E2 is field isolate-specific, while N40 of E2 and D100/V107 of Erns are vaccine strain-specific. Results from our study further indicate that N40D of E2 mutation in field strains was likely produced under positive selection associated with long-term mass vaccination, leading to CSFV evasion of host immune response. Taking together, this study provides new insights into the antigenic structure of CSFV E2 and Erns and the differentiating mAbs will contribute to the development of a diagnostic strategy to differentiate C-strain vaccination from natural infection (DIVA) of CSFV in terms of elimination of CSF in China

Site-Selective Difunctionalization of Arenes and Heteroarenes Enabled by Palladium/Norbornene Cooperative Catalysis

Poly-substituted aromatics are frequently found in pharmaceuticals and agrochemicals. During the past decades, cross-coupling reactions and nucleophilic aromatic substitutions (SNAr) have become indispensable tools for preparing functionalized arenes from readily available aryl halides. Recently, ortho metalation approaches, mediated by either stoichiometric organometallics or catalytic transition metals, enabled broadly useful ortho C−H functionalization. We were motivated by the merits of merging cross-coupling and ortho metalation, two powerful organic reactions, into a single palladium/norbornene (Pd/NBE)-catalyzed transformation. Pd/NBE catalysis, namely Catellani reaction, has recently emerged as a powerful approach for vicinal difunctionalization of arenes. Using simple aryl iodides as substrates, various nucleophiles and electrophiles have been installed at the ipso and ortho positions respectively through selective reactions with the aryl-norbornyl-palladacycle (ANP) intermediate. Some intrinsic challenges still exist in developing new Catellani-type transformation. First, the initially generated Pd(0) precatalyst must react with aryl iodide instead of the electrophile; thus, a fast/facile oxidative addition is necessary (Aryl Iodide Constraint). Second, the electrophile must selectively oxidize ANP instead of initially generated Pd(II) intermediate, which leads to a very limited electrophiles scope (Electrophile Constraint). Third, the NBE extrusion will only take place when two ortho positions of aryl iodide are blocked, otherwise undesired difunctionalization product or NBE-containing side products will be formed (Ortho Constraint). To address the aforementioned “Electrophile Constraint”, we developed a direct annulation strategy between aryl iodides and epoxides, affording the desired 2,3-dihydrobenzofuran derivatives in decent yields and regioselectivity. Meanwhile, asymmetric annulation was also realized by using chiral NBE co-catalyst. Application of this method into a concise synthesis of insecticide fufenozide was then demonstrated. In addition, inspired by our previously reported ortho amination of aryl iodide, we developed an ortho thiolation strategy enabled by a new class of sulfenamide electrophile, derived from a seven-membered lactam. The arene ipso functionalization is simultaneously achieved through Heck, Suzuki or Sonogashira termination. To overcome the “Aryl Iodide Constraint”, a redox-neutral ortho functionalization of aryl boroxines was developed. The reaction was initiated by a transmetalation of aryl boroxine to Pd(II) and terminated by a protodepalladation process, thereby avoiding stoichiometric amount of oxidant and reductant as well as tolerating a broader functional group including aryl iodide. In addition, a direct vicinal difunctionalization of thiophene was developed; this transformation was initiated by direct C−H palladation at C2 position of thiophene without aids of directing group, allowing for simultaneously installing two different functional groups at vicinal positions in a site-and regioselective manner. Then this difunctionalization method was successfully extended to other heteroarenes, including furans, pyrroles and indoles. Besides ortho arylation, ortho alkylation and ortho alkynylation were all realized with decent yields and regioselective. Meanwhile, a concise synthesis of Rhazinilam was realized to demonstrate the synthetic utility. Finally, a vicinal double C−H functionalization of five-membered heteroarenes with two different electrophiles in a site-selective and redox-neutral manner was realized by using aryl iodide as the first electrophile and alkynyl bromide as the second electrophile, enabling regioselective difunctionalization of a variety of five-membered heteroarenes at their C4 and C5 positions

Palladium-Catalyzed Asymmetric Annulation Between Aryl Iodides and Racemic Epoxides Using a Chiral Norbornene Cocatalyst

Herein, we describe our initial development of an asymmetric Pd-catalyzed annulation between aryl iodides and racemic epoxides for synthesis of 2,3-dihydrobenzofurans using a chiral norbornene cocatalyst. A series of enantiopure ester-, amide- and imide-substituted norbornenes have been prepared with a reliable synthetic route. Promising enantioselectivity (42-45% ee) has been observed using the isopropyl ester-substituted norbornene (N1*) and the amide-substituted norbornene (N7*)

Research on the Impact of Different Force Directions on the Mechanical Properties and Damage Evolution Law of Sandstone with Different Hole Diameters

In this research, a uniaxial acoustic emission experiment was conducted on rock samples with different positions and diameters of the hole, and an analysis was made on the impact of different hole positions and diameters on the mechanical properties, failure, energy conversion, and acoustic emission-caused damage characteristics and laws of the rock samples. The results reveal as follows: first, due to the existence of holes in rocks, the stress-strain curve changes at each stage, accompanied by multiple stress drops. And the peak strength gradually reduces with the increase in hole diameter. At different hole positions, the duration that the rock sample passes through at each stage of the stress-strain curve varies, and the peak strength of the rock with the vertical hole is greater than that of the rock with the horizontal hole. This indicates that the bearing capacity and stability of the rock sample with the vertical hole are greater than those of the rock sample with the horizontal hole of the same diameter. Second, by making a comparison on the failure characteristics of rock samples, it is found that the intact rock shows brittle failure. For the rock sample with the horizontal hole, symmetrical tensile cracks initially appear in the upper and lower parts of the hole and finally form shear failure. As for the rock sample with the vertical hole, Y-shape failure originally presents and eventually forms N-shape failure with the increase in hole diameter. Over a comparison with the failure pattern of an intact rock sample, it is demonstrated that the final failure pattern and crack expansion trend on the rock sample vary with the change in the hole position and diameter. Third, as obtained by comparing and analyzing the energy conversion of the rock with different diameters of the hole, the energy conversion in the rock is changed due to the existence of holes, and the increase in hole diameter causes a gradual decrease in the elastic energy stored in the rock and gradual increase in the dissipated energy. And by comparing the energy conversion of the rock with different positions of the hole, it is acquired that the elastic energy conversion ratio of the rock with the vertical hole is higher than that of the rock with the horizontal hole. Furthermore, an explanation was made on the difference in the failure processes of the two types of rocks from the perspective of energy conversion

Theories on formation of an anomalous anticyclone in western North Pacific during El Niño: A review

The article of record as published may be found at http://link.springer.com/article/10.1007/s13351-017-7147-6The western North Pacific anomalous anticyclone (WNPAC) is an important atmospheric circulation system that conveys El Niño impact on East Asian climate. In this review paper, various theories on the formation and maintenance of the WNPAC, including warm pool atmosphere–ocean interaction, Indian Ocean capacitor, a combination mode that emphasizes nonlinear interaction between ENSO and annual cycle, moist enthalpy advection/Rossby wave modulation, and central Pacific SST forcing, are discussed. It is concluded that local atmosphere–ocean interaction and moist enthalpy advection/Rossby wave modulation mechanisms are essential for the initial development and maintenance of the WNPAC during El Niño mature winter and subsequent spring. The Indian Ocean capacitor mechanism does not contribute to the earlier development but helps maintain the WNPAC in El Niño decaying summer. The cold SST anomaly in the western North Pacific, although damped in the summer, also plays a role. An interbasin atmosphere–ocean interaction across the Indo-Pacific warm pool emerges as a new mechanism in summer. In addition, the central Pacific cold SST anomaly may induce the WNPAC during rapid El Niño decaying/La Niña developing or La Niña persisting summer. The near-annual periods predicted by the combination mode theory are hardly detected from observations and thus do not contribute to the formation of the WNPAC. The tropical Atlantic may have a capacitor effect similar to the tropical Indian Ocean.National Key Research and Development ProgramNational Natural Science Foundation of ChinaUnited States National Science FoundationJiangsu Province Natural Science Foundation Key ProjectJiangsu Shuang-Chuang Team FundPriority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)41630423, 41475084, 41575043, and 41375095AGS-1565653BK20150062R2014SCT001SOEST contribution number 10280IPRC contribution number 1297ESMC contribution number 1962017YFA0603802 and 2015CB45320

Effect of the atmospheric heat source on the development and eastward movement of the Tibetan Plateau vortices

Based on the final analyses data (FNL) of the Global Forecasting System of the National Centers for Environment Prediction (NCEP) and the radiosonde data over the Tibetan Plateau, evolutions of two types of the Tibetan Plateau vortices, moving-off the plateau (Type A) and dying-out on the plateau (Type B), are investigated respectively. Compared to Type B vortices, the large-scale circulations associated with Type A vortices show stronger ridge to the north of the plateau and deeper trough near the Bay of Bengal at 500 hPa, and the southwesterly flow from the trough and the northwesterly flow from the ridge converge more intensively to the east of Type A vortices. Meanwhile, at 200 hPa the divergence on the right-hand side of the upper westerly jet is just over the vortices. The convergence at 500 hPa and divergence at 200 hPa provide favourable conditions for the development and eastward motion of the vortices. The diagnoses of the potential vorticity (PV) budgets reveal that in the developing stages of the two types of vortices, the vertical distribution of the atmospheric heat source determines both their intensity and the moving direction. In the decaying stage, the maintenance and eastward movement for Type A vortices mainly depend on the convergence of the strong northwesterly and southwesterly to the east of the vortices. For Type B vortices, the vertical PV flux divergence caused by the ascending motion around the vortices reduces the intensity of the vortices and is unfavourable for their eastward motion

Research on the Transportation of Low-Strength Composites Sheets

The novel non-combustible sandwich panel is extremely fragile in manufacturing and cannot be tensioned between rolls. Previous studies on the roll-to-roll system, which mainly focused on the high-tension situations and little described the low-strength materials, are insufficient. To explore the transportation of low-strength materials, we study the tension distribution of continuous moving flexible one-dimensional materials on a steady-state track. First, we propose a numerical method to calculate the steady-state track of low-strength sheet between rolls considering the gravity, as well as size and position of rolls. Then we obtain the optimum sag at different size and position of rolls. We find out that there is a lower limit of the sheet’s strength-density ratio (the Minimum Specific Strength) for a specific set of size and position of rolls. Finally, we establish a method to calculate the lower limit approximately for engineering use. Our method can be generalized in manufacturing other low-strength flexible thin-sheet materials as well