Modified Mesri creep modelling of soft clays in the coastal area of Tianjin (China)

Karakteristike nelinearnog puzanja tipičnih glina obalnog područja Tianjina analizirane su konsolidiranim-nedreniranim troosnim provjerama puzanjem. Provjere su izvedene stepwise metodom opterećenja, a krivulje puzanja mekih glina pod različitim stanjima naprezanja dobivene su iz podataka obrađenih Chen i Kang metodom. Eksperimenti su pokazali da se dugotrajna deformacija mekih glina može podijeliti na dvije faze, deformaciju dobivenu povećanjem naprezanja i deformaciju dobivenu konstantnim opterećenjem. Analizom podataka provjere postavljen je modificirani Mesri model temeljen na klasičnom Mesri modelu puzanja koji je tretirao finalno naprezanje deformacije tla prvog stupnja kao početno naprezanje i opisao deformaciju tla drugog stupnja primjenom kombinacije hiperboličke funkcije naprezanje-izduženje i hiperboličke funkcije izduženje-vrijeme. Modificirani model sadrži četiri parametra; svi parametri imaju jasno fizikalno značenje i mogu se odrediti eksperimentom. Provjera je pokazala da se rezultati dobiveni proračunom dobro slažu s eksperimentalnima. Zbog daljnje provjere model se primijenio u proračunu dugoročnog naselja u obalnom području Tianjina. Rezultati su pokazali da se modificiranim modelom može uz zadovoljavajuću točnost predvidjeti dugotrajna deformacija mekih glina uslijed puzanja.The nonlinear creep characteristics of typical clays in the coastal area of Tianjin were studied by consolidated-undrained triaxial creep tests. The tests were performed via the stepwise loading method, and the creep curves of the soft clays under different stress states were obtained from the raw data processed by Chen and Kang’s method. The experiments showed that the long-term deformation of soft clays can be divided into two stages, that is, the deformation produced by increasing stress and the deformation produced by a constant load. By analysing the test data, a modified Mesri model was established based on the classical Mesri creep model, which treated the final strain of the first-stage soil deformation as the initial strain and described the second-stage soil deformation using a combination of a stress-strain hyperbolic function and strain-time hyperbolic function. The modified model contains four parameters; all of the parameters have clear physical significance and can be determined by experiment. Verification indicated that the calculated results were in good agreement with the experimental ones. For further verification, the model was applied to the calculation of the long-term settlement in the coastal area of Tianjin. The results showed that the modified model can predict the long-term creep deformation of soft clays with a satisfactory accuracy

A high infectious simian adenovirus type 23 vector based vaccine efficiently protects common marmosets against Zika virus infection.

Zika virus (ZIKV) has spread in many countries or territories causing severe neurologic complications with potential fatal outcomes. The small primate common marmosets are susceptible to ZIKV, mimicking key features of human infection. Here, a novel simian adenovirus type 23 vector-based vaccine expressing ZIKV pre-membrane-envelope proteins (Sad23L-prM-E) was produced in high infectious titer. Due to determination of immunogenicity in mice, a single-dose of 3×108 PFU Sad23L-prM-E vaccine was intramuscularly inoculated to marmosets. This vaccine raised antibody titers of 104.07 E-specific and 103.13 neutralizing antibody (NAb), as well as robust specific IFN-γ secreting T-cell response (1,219 SFCs/106 cells) to E peptides. The vaccinated marmosets, upon challenge with a high dose of ZIKV (105 PFU) six weeks post prime immunization, reduced viremia by more than 100 folds, and the low level of detectable viral RNA (103.66) and T-cell response (>726 SFCs/106 PBMCs) were acquired 1-2 weeks post exposure to ZIKV, while non-vaccinated control marmosets developed long-term high titer of ZIKV (105.73 copies/ml) (P<0.05). No significant pathological lesions were observed in marmoset tissues. Sad23L-prM-E vaccine was detectable in spleen, liver and PBMCs at least 4 months post challenge. In conclusion, a prime immunization with Sad23L-prM-E vaccine was able to protect marmosets against ZIKV infection when exposed to a high dose of ZIKV. This Sad23L-prM-E vaccine is a promising vaccine candidate for prevention of ZIKV infection in humans

Hydrodynamic response for flexible connectors of mobile offshore base at rough sea states

Mobile offshore base (MOB) was treated as a research object, and a simplified algorithm was developed for determining the dynamic constraint forces on flexible connectors of MOB at rough sea states. The algorithm was adopted to calculate and analyze the fluctuation laws between dynamic constraint forces and different parameters. The wave loads on MOB structures were evaluated based on the revised Morison equation instead of potential flow theory, and the conventional computational methods were simplified. The numerical results of the simplified algorithm were compared to those of the algorithm based on potential flow theory for validating the correctness and reasonability of the simplified algorithm. The simplified algorithm was used to estimate the dynamic constraint forces on flexible connectors of MOB under different sea states, wave incident directions, and connector stiffness values. The results show as the wave angle increases, the dynamic constraint force decreases in the x direction, while increases first and then decreases in the y and z directions; the dynamic constraint force increases as the sea state increases, and shows a trend of linear increasing with the connector stiffness increasing; the dynamic forces on different connectors are well even in the same conditions. Key words: mobile offshore base (MOB), semi-submersible platform, flexible connector, dynamic constraint force, rough sea stat

A high infectious simian adenovirus type 23 vector based vaccine efficiently protects common marmosets against Zika virus infection.

Zika virus (ZIKV) has spread in many countries or territories causing severe neurologic complications with potential fatal outcomes. The small primate common marmosets are susceptible to ZIKV, mimicking key features of human infection. Here, a novel simian adenovirus type 23 vector-based vaccine expressing ZIKV pre-membrane-envelope proteins (Sad23L-prM-E) was produced in high infectious titer. Due to determination of immunogenicity in mice, a single-dose of 3×108 PFU Sad23L-prM-E vaccine was intramuscularly inoculated to marmosets. This vaccine raised antibody titers of 104.07 E-specific and 103.13 neutralizing antibody (NAb), as well as robust specific IFN-γ secreting T-cell response (1,219 SFCs/106 cells) to E peptides. The vaccinated marmosets, upon challenge with a high dose of ZIKV (105 PFU) six weeks post prime immunization, reduced viremia by more than 100 folds, and the low level of detectable viral RNA (103.66) and T-cell response (>726 SFCs/106 PBMCs) were acquired 1-2 weeks post exposure to ZIKV, while non-vaccinated control marmosets developed long-term high titer of ZIKV (105.73 copies/ml) (P<0.05). No significant pathological lesions were observed in marmoset tissues. Sad23L-prM-E vaccine was detectable in spleen, liver and PBMCs at least 4 months post challenge. In conclusion, a prime immunization with Sad23L-prM-E vaccine was able to protect marmosets against ZIKV infection when exposed to a high dose of ZIKV. This Sad23L-prM-E vaccine is a promising vaccine candidate for prevention of ZIKV infection in humans

Significance of monoclonal antibodies against the conserved epitopes within non-structural protein 3 helicase of hepatitis C virus.

Nonstructural protein 3 (NS3) of hepatitis C virus (HCV), codes for protease and helicase carrying NTPase enzymatic activities, plays a crucial role in viral replication and an ideal target for diagnosis, antiviral therapy and vaccine development. In this study, monoclonal antibodies (mAbs) to NS3 helicase were characterized by epitope mapping and biological function test. A total of 29 monoclonal antibodies were produced to the truncated NS3 helicase of HCV-1b (T1b-rNS3, aa1192-1459). Six mAbs recognized 8/29 16mer peptides, which contributed to identify 5 linear and 1 discontinuous putative epitope sequences. Seven mAbs reacted with HCV-2a JFH-1 infected Huh-7.5.1 cells by immunofluorescent staining, of which 2E12 and 3E5 strongly bound to the exposed linear epitope (1231)PTGSGKSTK(1239) (EP05) or core motif (1373)IPFYGKAI(1380) (EP21), respectively. Five other mAbs recognized semi-conformational or conformational epitopes of HCV helicase. MAb 2E12 binds to epitope EP05 at the ATP binding site of motif I in domain 1, while mAb 3E5 reacts with epitope EP21 close to helicase nucleotide binding region of domain 2. Epitope EP05 is totally conserved and EP21 highly conserved across HCV genotypes. These two epitope peptides reacted strongly with 59-79% chronic and weakly with 30-58% resolved HCV infected blood donors, suggesting that these epitopes were dominant in HCV infection. MAb 2E12 inhibited 50% of unwinding activity of NS3 helicase in vitro. Novel monoclonal antibodies recognize highly conserved epitopes at crucial functional sites within NS3 helicase, which may become important antibodies for diagnosis and antiviral therapy in chronic HCV infection

Specificity of two linear epitopes within NS3 helicases of HCV and other flaviviruses.

<p>(A) Analysis of amino acid sequence corresponding to EP05 and EP21 regions within NS3 helicase cross HCV genotypes and other flaviviruses. Aa sequences (one-letter code) to epitopes of HCV genotype 1b are presented on the top. Positions at the beginning and end of sequences are indicated by numbers. Identities with the lead sequence are indicated by dashes. Representative sequences are retrieved from Genebank Database. Triangles labeling with EP05/2E12 or EP21/3E5 on the top indicate epitope sequences or corresponding sequences for mAb’s recognition. The aa residues GSGKS underlined in bold indicate the ATP binding site of motif I (Walker A) within NS3 helicase. n.a. indicates no corresponding sequence available from those viruses. (B and C) Reactivity of mAb 2E12 or 3E5 with mutant peptide corresponding to the defined epitope sequence in Peptide-ELISA.</p

Reactivity of epitope peptides with HCV infected plasmas.

<p>Reactivity of epitope peptides with HCV infected plasmas.</p