The complex physical process of welding residual stress relieving by means of explosive technique is studied experimentally and numerically. The experiments are carried out in welded 16 MnR steel plates. In the numerical simulations, the explicit dynamic finite element method is adopted. The results from experiments and computations are consistent with each other. The mechanism of this technique is explained by considering the effect of stress wave reflection and superposition on the redistribution of stresses in this process. Based on the above studies, some advises and parameters are provided to practical applications of this technique.
To investigate the effects of letherally total body irradiation (TBI) on distribution of T-lymphocyte subtypes and their cytokine expression.The BALB/c mice were divided randomly into ⁶⁰Co gamma rays TBI group and control group. Mice were sacrificed 7 days after irradiation. The lymphocytes in spleens, mesenteric lymphonodes, livers and bone marrow were collected and counted. Changes of CD4(+) T and CD8(+) T cell subsets as well as the expressions of IFN-γ and IL-17 were analyzed by flow cytometry.(1)Compared with control group, the total number of lymphocytes in marrow, spleen, lymph node and liver distinctively decreased in TBI group [(5.34±1.14)×10⁵ vs (3.08±1.13)×10⁷, (2.10±0.54)×10⁵ vs (2.71±0.83)×10⁷, (5.89±1.07)×10⁵ vs (7.92±1.15)×10⁷ and (3.45±1.01)×10⁵ vs (7.44±0.79)×10⁶, respectively, and the significant differences were observed between two groups in each organ (P<0.05)]. (2)The level of IFN-γ produced by CD4(+) T in spleen, lymph node and liver elevated in TBI group compared to control group, which were (20.77±2.03)% vs (3.69±3.13)%, (6.28±0.46)% vs (1.11±0.17)%, (27.24±5.79)% vs (9.01±1.24)% respectively, the differences between two groups in each organ were significant (P<0.05). (3)Percentages of IFN-γ(+)CD8(+) T in spleen, lymph node and liver in TBI group increased compared to control group [(52.40±9.26)% vs (43.06±1.04)%, (33.56±5.02)% vs (21.83±4.22)%, and (44.27±8.97)% vs (19.32±3.11)%, respectively, and the differences between two groups in each tissue were significant (P<0.05)]. (4)However, IL-17A expressions in CD4(+) T and CD8(+) T cells from spleen and liver were lower than those in control group.TBI induced the reduction of lymphocytes and the expansion of IFN-γ producing Th1 and Tc1 effector cells in mice.
Background Although the Newcastle disease virus (NDV) inactivated vaccines and attenuated live vaccines have been used to prevent and control Newcastle disease (ND) for years, there are some disadvantages. Recently, newly developed DNA vaccines have the potential to overcome these disadvantages. The low delivery efficiency, however, hindered the application of DNA vaccines for ND in practice. Methodology/Principal Findings The eukaryotic expression plasmid pVAX1-F (o) DNA that expressed the F gene of NDV encapsulated in PLGA nanoparticles (pFNDV-PLGA-NPs) were prepared by a double emulsion-solvent evaporation method and optimal preparation conditions of the pFNDV-PLGA-NPs were determined. Under the optimal conditions, the pFNDV-PLGA-NPs were produced in good morphology and had high stability with a mean diameter of 433.5±7.5 nm, with encapsulation efficiency of 91.8±0.3% and a Zeta potential of +2.7 mV. Release assay in vitro showed that the fusion gene plasmid DNA could be sustainably released from the pFNDV-PLGA-NPs up to 93.14% of the total amount. Cell transfection test indicated that the vaccine expressed and maintained its bioactivity. Immunization results showed that better immune responses of SPF chickens immunized with the pFNDV-PLGA-NPs were induced compared to the chickens immunized with the DNA vaccine alone. In addition, the safety of mucosal immunity delivery system of the pFNDV-PLGA-NPs was also tested in an in vitro cytotoxicity assay. Conclusions/Significance The pFNDV-PLGA-NPs could induce stronger cellular, humoral, and mucosal immune responses and reached the sustained release effect. These results laid a foundation for further development of vaccines and drugs in PLGA nanoparticles.
The principle of discernibility matrix serves as a tool to discuss and analyze two algorithms of traditional inductive machine learning, AQ11 and ID3. The results are: (1) AQ11 and its family can be completely specified by the principle of discernibility matrix; (2) ID3 can be partly, but not naturally, specified by the principle of discernibility matrix; and (3) The principle of discernibility matrix is employed to analyze Cendrowska sample set, and it shows the weaknesses of knowledge representation style of decision tree in theory.
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