successive passage
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2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Thierry Tran ◽  
Graham A. Worth ◽  
Michael A. Robb

AbstractThe study of coupled electron-nuclear dynamics driven by coherent superpositions of electronic states is now possible in attosecond science experiments. The objective is to understand the electronic control of chemical reactivity. In this work we report coherent 8-state non-adiabatic electron-nuclear dynamics simulations of the benzene radical cation. The computations were inspired by the extreme ultraviolet (XUV) experimental results in which all 8 electronic states were prepared with significant population. Our objective was to study the nuclear dynamics using various bespoke coherent electronic state superpositions as initial conditions in the Quantum-Ehrenfest method. The original XUV measurements were supported by Multi-configuration time-dependent Hartree (MCTDH) simulations, which suggested a model of successive passage through conical intersections. The present computations support a complementary model where non-adiabatic events are seen far from a conical intersection and are controlled by electron dynamics involving non-adjacent adiabatic states. It proves to be possible to identify two superpositions that can be linked with two possible fragmentation paths.


Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 391 ◽  
Author(s):  
Pengwei Zhao ◽  
Song Wang ◽  
Zhi Chen ◽  
Jiang Yu ◽  
Rongzhi Tang ◽  
...  

A highly virulent porcine epidemic diarrhea virus (PEDV) appeared in China and spread rapidly to neighbor countries, which have led to great economic losses to the pig industry. In the present study, we isolated a PEDV using Vero cells and serially propagated 100 passages. PEDV SDSX16 was characterized in vitro and in vivo. The viral titers increased to 107.6 TCID50/mL (100th) by serial passages. The spike (S) gene and the whole gene of the SDSX16 virus was fully sequenced to assess the genetic stability and relatedness to previously identified PEDV. Along with successive passage in vitro, there were 18 nucleotides (nt) deletion occurred in the spike (S) gene resulting in a deletion of six amino acids when the SDSX16 strain was passaged to the 64th generation, and this deletion was stable until the P100. However, the ORF1a/b, M, N, E, and ORF3 genes had only a few point mutations in amino acids and no deletions. According to growth kinetics experiments, the SDSX16 deletion strain significantly enhanced its replication in Vero cells since it was passaged to the 64th generation. The animal studies showed that PEDV SDSX16-P10 caused more severe diarrhea and vomiting, fecal shedding, and acute atrophic enteritis than SDSX16-P75, indicating that SDSX16-P10 is enteropathogenic in the natural host, and the pathogenicity of SDSX16 decreased with successive passage in vitro. However, SDSX16-P10 was found to cause lower levels of cytokine expression than SDSX16-P75 using real-time PCR and flow cytometry, such as IL1β, IL6, IFN-β, TNF-α, indicating that SDSX16-P10 might inhibit the expression of cytokines. Our data indicated that successive passage in vitro resulted in virulent attenuation in vivo of the PEDV variant strain SDSX16.


Author(s):  
M.T. Dovzhik

The process of mixing the components of the mixture is an important factor affecting the physical and mechanical properties and appearance of the final product. The proposed designs of vibroexcluders for mixing fibrous concrete and the formation of flat products provided analytical formulas for calculating the process of vibration extrusion. The quantitative criterion of laminar convective mixing, which occurs when vibroexclusion, is the degree of increase in the surface area of the interface between the components, which in turn depends on the total deformation and initial orientation of the surface. The constructions of vibroextruders are provided for the mixing of a fibrous concrete and forming flat products, and analytical formulas are given for the calculation of the vibroextrusion process. The construction of a cascade vibrating extruder for the proposed mixing can be applied to a wide range of compositions of fibro concrete mixes, and a specially designed vibratory extruder for forming can significantly improve the longitudinal orientation of dispersed fittings in flat products. The degree of longitudinal orientation of the fiber in the process of vibroexclusion of fiber concrete can be regulated by the geometry and size of the channels of the vibroexcutter bunker, as well as by the application of special guiding partitions. Practically the degree of mixing is characterized by the speed of vibration exclusion. Due to the fact that the vibroextrusion mixing does not occur the destruction of fiber reinforcement, as a result of the successive passage of the mixture through several channels, the moment when the vibration excursion velocity stabilizes. The given analytical dependencies give the possibility of quantitative description of differences in the deformation of the mixture and the final orientation of fibers in the products for the proposed apparatus. The degree of longitudinal orientation fibers need to be set separately for different products, depending on their purpose, and change the degree of orientation is carried out by changing the geometry of the vane bunker vibroextruder. The results of the work are supposed to be used in the design of a new vibration excretory equipment for mixing fibrous concrete mixtures and the formation of dispersed reinforced products.


2018 ◽  
Vol 51 (1) ◽  
pp. 32
Author(s):  
P. YPSILANTIS (Π. ΥΨΗΛΑΝΤΗΣ)

Its application improves the reproduction rate, creates experimental models for the study of physiology and pathology of reproduction, while it promotes genetic improvement of the species. The method includes the following stages: 1) Selection of the donor and recipient mares. 2) Induction of multiple ovulation in the donor-mare. A reliable method that could be applied commercially has not been developed yet. 3) Synchronization of donor and recipient mares' estrus. Recipients are usually used during the breeding season, but can be used during anestrus or after surgical removal of their ovaries as well. Non-synchronized recipients may also be used after proper treatment. 4) Artificial insemination of the donor mare. 5) Collection, evaluation and washing of the embryo. Embryo is usually collected by non-surgical and rarely surgical methods. Embryo evaluation involves the assessment of its developmental stage in relation with the day of selection and its quality evaluation. Embryo washing is accomplished by its successive passage through three different dilutions of culture medium. 6) Embryo transfer in the uterus of the recipient mare. Surgical (midventral laparotomy, flank laporotomy, laparoscopic and transvaginal method) or nonsurgical (unguarded and guarded methods) transcervical methods are used.


2014 ◽  
Vol 59 (1) ◽  
Author(s):  
Tomohide Matsuo ◽  
Yasuko Tsuge ◽  
Rika Umemiya-Shirafuji ◽  
Takashi Fujino ◽  
Toshihiro Matsui

AbstractThe adaptation and immunogenisity of Cryptosporidium parvum isolated from Siberian chipmunks (SC1 strain) in immunocompetent (ICR) mice were examined. The oocysts were received to the severe combined immunodeficiency (SCID) mice by repeated passage. The oocysts collected from the 18th SCID mice were inoculated to 5 ICR mice. The mice began to shed oocysts from 6 days after inoculation, the patency was 5 days, and the maximum oocysts per gram of feces (OPG) value was 104. The maximum of OPG value was gradually increased by successive passage, and finally that in the 22nd mice reached 106 (patency: 11 days). It is considered that these results indicate completion of their adaptation to ICR mice. To examine the immunogenicity of C. parvum to ICR mice, 8 groups of 5 mice each were inoculated with 1.3 × 106 oocysts of SC1 strain, which were collected after adaptation to SCID mice. All groups shed oocysts from 6th day, and their patency was from 8 to 12 days. On the 21st day after the primary infection, these mice were challenged with 1.3 × 106 oocysts. No oocysts shed from any groups, although 2 control groups shed oocysts from the 6th day, and their OPG values were more than 106. These results suggest that this strain has strong immunogenicity against ICR mice. Therefore, the immunological healthy mice were considered a useful experimental model to investigate immunological and drug treatments in the strain of C. parvum.


2011 ◽  
Vol 25 (03) ◽  
pp. 417-431
Author(s):  
DEBRAJ NATH ◽  
P. K. DAS

In this paper we discuss an extension of Jaynes–Cummings model by adding a further atomic level to support a second resonance and cooperative effects in multi-atom systems. A successive passage of a three-level atom in the V configuration interacting with one quantized mode of electromagnetic field in a cavity will be considered to study atomic inversion and entropy evolution of the state.


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