Tổng hợp và biểu hiện gen caf1 mã hóa kháng nguyên F1 của vi khuẩn Yersinia pestis

Yersinia pestis is the etiologic agent of plague, one of the most deadly infectious diseases described in the history of humanity. It was responsible for millions of deaths all over the world. Yersinia pestis also can be used as a highly lethal biological potential weapon. For plague diagnosis in humans as well as to detect Y. pestis in the environment, fraction 1 capsular antigen (F1) of the bacteria was usually used as a good marker. The aim of this study is to produce Y. pestis F1 antigen to serve as a material for development of immunochromatographic test strips for rapid detection of Y. pestis. Because of the difficulty in Y. pestis culture for DNA extraction as well as F1 antigen production, we artificially synthesized the target caf1 coding for F1 antigen for expression in Escherichia coli. After the codon optimization step, caf1 was synthesized by “gapless” PCR using 22 overlaping oligonucleotides cover the complete sequence of this gene. The sequencing result showed that we successfully synthesized the target gene. In total 6 clones sequence, there are 2 clones sequence which were 100% identity with reference sequence. The target sequence was then introduced into pET-52b(+) vector and expressed in E. coli BL21 (DE3) in the form of (His)10 affinity tag fusion. As the result of SDS-PAGE, the recombinant protein Caf1 of 18 kDa was highly expressed in E. coli as inclusion body form and was purified by His-tag affinity chromatography. The recombinant Caf1 was then confirmed by Western blot with His-tag antibody.Vi khuẩn Yersinia pestis là tác nhân gây bệnh dịch hạch, một trong những loại bệnh truyền nhiễm nguy hiểm nhất được biết cho đến nay đã gây ra hàng triệu ca tử vong trên thế giới và có thể được sử dụng như một vũ khí sinh học có tính hủy diệt cao. Để chẩn đoán bệnh dịch hạch ở người cũng như phát hiện Y. pestis trong môi trường, người ta thường dựa trên việc phát hiện kháng nguyên nang F1 của loại vi khuẩn này. Mục tiêu của nghiên cứu này là nhằm tạo kháng nguyên F1 của Y. pestis để làm nguyên liệu cho que thử sắc ký miễn dịch phát hiện nhanh Y. pestis. Do việc nuôi cấy Y. pestis để thu nhận kháng nguyên F1 hoặc DNA của vi khuẩn này rất khó khăn nên chúng tôi đã tiến hành tổng hợp nhân tạo gen mục tiêu caf1, mã hóa kháng nguyên F1, nhằm biểu hiện trong tế bào Escherichia coli. Sau khi tối ưu hóa mã bộ ba mã hóa amino acid (codon) cho E. coli, gen caf1 đã được tổng hợp bằng phương pháp “gapless” PCR. Kết quả giải trình tự cho thấy phương pháp này cho phép tổng hợp được trình tự gen mục tiêu với độ chính xác là 2/6 dòng plasmid. Tiếp đó, trình tự gen này đã được đưa vào vector pET-52b(+) và biểu hiện trong tế bào E. coli BL21 (DE3) ở dạng dung hợp với đuôi ái lực (His)10. Các kết quả điện di protein SDS-PAGE, tinh sạch protein bằng sắc ký ái lực Ni và Western blot cho thấy kháng nguyên tái tổ hợp F1 đã được tạo ra thành công với hiệu suất lớn ở dạng thể vùi trong tế bào E. coli

Phân tích nhiệt ứng dụng trong nghiên cứu vật liệu

234 tr. ; 24 cm

LINEAR AND NONLINEAR ANALYSIS OF THE RAYLEIGH-TAYLOR SYSTEM WITH NAVIER-SLIP BOUNDARY CONDITIONS

In this paper, we are interested in the linear and the nonlinear Rayleigh instability for the incompressible Navier-Stokes equations with Navier-slip boundary conditions around a laminar smooth density profile $\rho_0(x_2)$ being increasing in an infinite slab $2\pi L\mathbb{T} \times (-1,1)$ ($L>0$, $\mathbb{T}$ is the usual 1D torus). The linear instability study of the viscous Rayleigh-Taylor model amounts to the study of the following ordinary differential equation on the finite interval $(-1,1)$, \begin{equation}\label{EqMain}-\lambda^2 [ \rho_0 k^2 \phi - (\rho_0 \phi')'] = \lambda \mu (\phi^{(4)} - 2k^2 \phi'' + k^4 \phi) - gk^2 \rho_0'\phi,\end{equation} with the boundary conditions \begin{equation}\label{4thBound}\begin{cases}\phi(-1)=\phi(1)=0,\\\mu \phi''(1) = \xi_+ \phi'(1), \\\mu \phi''(-1) =- \xi_- \phi'(-1),\end{cases}\end{equation}where $\lambda$ is the growth rate in time, $k$ is the wave number transverse to the density profile and two Navier-slip coefficients $\xi_{\pm}$ are nonnegative constants. For each $k\in L^{-1}\mathbb{Z}\setminus\{0\}$, we define a threshold of viscosity coefficient $\mu_c(k,\Xi)$ for linear instability. So that, in the $k$-supercritical regime, i.e. $\mu>\mu_c(k,\Xi)$, we provide a spectral analysis adapting the operator method of Lafitte-Nguyễn and then prove that there are infinite solutions of \eqref{EqMain}-\eqref{4thBound}. Secondly, we will extend a result of Grenier, by considering a wider class of initial data to the nonlinear perturbation problem, based on infinitely unstable modes of the linearized problem and we will prove nonlinear Rayleigh-Taylor instability in a high regime of viscosity coefficient, namely $\mu >3\sup_{k\in L^{-1}\mathbb{Z}\setminus\{0\} }\mu_c(k,\Xi)$

Cơ sở số học

206 tr. ; 24 cm

Số học : Tài liệu đào tạo giáo viên tiểu học trình độ đại học

150 tr. ; 30 cm

NONLINEAR RAYLEIGH-TAYLOR INSTABILITY OF THE VISCOUS SURFACE WAVE IN AN INFINITELY DEEP OCEAN

In this paper, we consider an incompressible viscous fluid in an infinitely deep ocean, being bounded above by a free moving boundary. The governing equations are the gravity-driven incompressible Navier-Stokes equations with variable density and no surface tension is taken into account on the free surface. After using the Lagrangian transformation, we write the main equations in a perturbed form in a fixed domain. In the first part, we describe a spectral analysis of the linearized equations around a hydrostatic equilibrium $(\rho_0(x_3), 0, P_0(x_3)$ for a smooth increasing density profile $\rho_0$. Precisely, we prove that there exist infinitely many normal modes to the linearized equations by following the operator method initiated by Lafitte and Nguyễn. In the second part, we study the nonlinear Rayleigh-Taylor instability around the above profile by constructing a wide class of initial data for the nonlinear perturbation problem departing from the equilibrium, based on the finding of infinitely many normal modes. Our nonlinear result extends the previous framework of Guo and Strauss and also of Grenier

LINEAR AND NONLINEAR ANALYSIS OF THE VISCOUS RAYLEIGH-TAYLOR SYSTEM WITH NAVIER-SLIP BOUNDARY CONDITIONS

In this paper, we are interested in the linear and the nonlinear Rayleigh instability for the gravity-driven incompressible Navier-Stokes equations with Navier-slip boundary conditions around an increasing density profile $\rho_0(x_2)$ in a slab domain $2\pi L\mathbb{T} \times (-1,1)$ ($L>0$, $\mathbb{T}$ is the usual 1D torus). The linear instability study of the viscous Rayleigh-Taylor model amounts to the study of the following ordinary differential equation on the finite interval $(-1,1)$ , \begin{equation}\label{EqMain}-\lambda^2 [ \rho_0 k^2 \phi - (\rho_0 \phi')'] = \lambda \mu (\phi^{(4)} - 2k^2 \phi'' + k^4 \phi) - gk^2 \rho_0'\phi,\end{equation} with the boundary conditions \begin{equation}\label{4thBound}\begin{cases}\phi(-1)=\phi(1)=0,\\\mu \phi''(1) = \xi_+ \phi'(1), \\\mu \phi''(-1) =- \xi_- \phi'(-1),\end{cases}\end{equation}where $\lambda>0$ is the growth rate in time, $g>0$ is the gravity constant, $k$ is the wave number and two Navier-slip coefficients $\xi_\pm$ are nonnegative constants. For each$k\in L^{-1} mathbb{Z}\setminus\{0\}$, we define a threshold of viscosity coefficient $\mu_c(k,\Xi)$ for the linear instability. So that, in the k-supercritical regime, i.e. $μ>\mu_c(k,\Xi)$, we describe a spectral analysis adapting the operator method initiated by Lafitte-Nguyễn and then prove that there are infinite nontrivial solutions $(\lambda_n,\phi_n)$ of (0.1)-(0.2) with $\lambda_n\to 0$ as $n\to \infty$ and $\phi_n \in H^4(\mathbf{R}_-) Based on the existence of infinitely many normal modes of the linearized problem, we construct a wide class of initial data to the nonlinear equations, extending the previous framework of Guo-Strauss and of Grenier, to prove the nonlinear Rayleigh-Taylor instability in a high regime of viscosity coefficient

LINEAR AND NONLINEAR ANALYSIS OF THE VISCOUS RAYLEIGH-TAYLOR SYSTEM WITH NAVIER-SLIP BOUNDARY CONDITIONS

In this paper, we are interested in the linear and the nonlinear Rayleigh instability for the gravity-driven incompressible Navier-Stokes equations with Navier-slip boundary conditions around an increasing density profile $\rho_0(x_2)$ in a slab domain $2\pi L\mathbb{T} \times (-1,1)$ ($L>0$, $\mathbb{T}$ is the usual 1D torus). The linear instability study of the viscous Rayleigh-Taylor model amounts to the study of the following ordinary differential equation on the finite interval $(-1,1)$ , \begin{equation}\label{EqMain}-\lambda^2 [ \rho_0 k^2 \phi - (\rho_0 \phi')'] = \lambda \mu (\phi^{(4)} - 2k^2 \phi'' + k^4 \phi) - gk^2 \rho_0'\phi,\end{equation} with the boundary conditions \begin{equation}\label{4thBound}\begin{cases}\phi(-1)=\phi(1)=0,\\\mu \phi''(1) = \xi_+ \phi'(1), \\\mu \phi''(-1) =- \xi_- \phi'(-1),\end{cases}\end{equation}where $\lambda>0$ is the growth rate in time, $g>0$ is the gravity constant, $k$ is the wave number and two Navier-slip coefficients $\xi_\pm$ are nonnegative constants. For each$k\in L^{-1} mathbb{Z}\setminus\{0\}$, we define a threshold of viscosity coefficient $\mu_c(k,\Xi)$ for the linear instability. So that, in the k-supercritical regime, i.e. $μ>\mu_c(k,\Xi)$, we describe a spectral analysis adapting the operator method initiated by Lafitte-Nguyễn and then prove that there are infinite nontrivial solutions $(\lambda_n,\phi_n)$ of (0.1)-(0.2) with $\lambda_n\to 0$ as $n\to \infty$ and $\phi_n \in H^4(\mathbf{R}_-) Based on the existence of infinitely many normal modes of the linearized problem, we construct a wide class of initial data to the nonlinear equations, extending the previous framework of Guo-Strauss and of Grenier, to prove the nonlinear Rayleigh-Taylor instability in a high regime of viscosity coefficient

NONLINEAR RAYLEIGH-TAYLOR INSTABILITY OF THE VISCOUS SURFACE WAVE IN AN INFINITELY DEEP OCEAN

In this paper, we consider an incompressible viscous fluid in an infinitely deep ocean, being bounded above by a free moving boundary. The governing equations are the gravity-driven incompressible Navier-Stokes equations with variable density and no surface tension is taken into account on the free surface. After using the Lagrangian transformation, we write the main equations in a perturbed form in a fixed domain. In the first part, we describe a spectral analysis of the linearized equations around a hydrostatic equilibrium $(\rho_0(x_3), 0, P_0(x_3)$ for a smooth increasing density profile $\rho_0$. Precisely, we prove that there exist infinitely many normal modes to the linearized equations by following the operator method initiated by Lafitte and Nguyễn. In the second part, we study the nonlinear Rayleigh-Taylor instability around the above profile by constructing a wide class of initial data for the nonlinear perturbation problem departing from the equilibrium, based on the finding of infinitely many normal modes. Our nonlinear result extends the previous framework of Guo and Strauss and also of Grenier