The continuous model of liquid crystals and the corresponding symmetry are discussed, from which the expression of the density of free energy is deducted. Based on the transformation of vector field, four typical impo...The continuous model of liquid crystals and the corresponding symmetry are discussed, from which the expression of the density of free energy is deducted. Based on the transformation of vector field, four typical important ways of distribution of the vector field are discussed and the stable conditions of the distribution are induced.展开更多
The V-shaped electro-optical properties control is investigated by an equivalent circuit model.Simu-lation results show that genuine V-shaped form is only observed at hysteresis inversion frequency,and be-low and abov...The V-shaped electro-optical properties control is investigated by an equivalent circuit model.Simu-lation results show that genuine V-shaped form is only observed at hysteresis inversion frequency,and be-low and above this frequency an anomalous and normal hysteresis are observed.And the inversion fre-quency decreases with the resistance of ferroelectric liquid crystal(FLC)layer following logf_i=-alogR_(LC)+b .The results are in good accordance with the reported experimental results.展开更多
Dynamical properties of liquid in nano-channels attract much interest because of their applications in engineering and biological systems. The transfer behavior of liquid confined within nanopores differs significantl...Dynamical properties of liquid in nano-channels attract much interest because of their applications in engineering and biological systems. The transfer behavior of liquid confined within nanopores differs significantly from that in the bulk. Based on the simple quasicrystal model of liquid, analytical expressions of self-diffusion coefficient both in bulk and in slit nanopore are derived from the Stokes–Einstein equation and the modified Eyring's equation for viscosity. The local self-diffusion coefficient in different layers of liquid and the global self-diffusion coefficient in the slit nanopore are deduced from these expressions. The influences of confinement by pore walls,pore widths, liquid density, and temperature on the self-diffusion coefficient are investigated. The results indicate that the self-diffusion coefficient in nanopore increases with the pore width and approaches the bulk value as the pore width is sufficiently large. Similar to that in bulk state, the self-diffusion coefficient in nanopore decreases with the increase of density and the decrease of temperature, but these dependences are weaker than that in bulk state and become even weaker as the pore width decreases. This work provides a simple method to capture the physical behavior and to investigate the dynamic properties of liquid in nanopores.展开更多
AIM： To develop a method of labeling and microdissecting mouse Kupffer cells within an extraordinarily short period of time using laser capture microdissection （LCM）. METHODS： Tissues are complex structures compri...AIM： To develop a method of labeling and microdissecting mouse Kupffer cells within an extraordinarily short period of time using laser capture microdissection （LCM）. METHODS： Tissues are complex structures comprised of a heterogeneous population of interconnected cells. LCM offers a method of isolating a single cell type from specific regions of a tissue section. LCM is an essential approach used in conjunction with molecular analysis to study the functional interaction of cells in their native tissue environment. The process of labeling and acquiring cells by LCM prior to mRNA isolation can be elaborate, thereby subjecting the RNA to considerable degradation. Kupffer cell labeling is achieved by injecting India ink intravenously, thus circumventing the need for in vitro staining. The significance of this novel approach was validated using a cholestatic liver injury model. RESULTS： mRNA extracted from the microdissected cell population displayed marked increases in colonystimulating factor-1 receptor and Kupffer cell receptor message expression, which demonstrated Kupffer cell enrichment. Gene expression by Kupffer ceils derived from bile-duct-ligated, versus sham-operated, mice was compared. Microarray analysis revealed a significant （2.5-fold, q value 〈 10） change in 493 genes. Based on this fold-change and a standardized PubMed search, 10 genes were identified that were relevant to the ability of Kupffer cells to suppress liver injury. CONCLUSION; The methodology outlined herein provides an approach to isolating high quality RNA from Kupffer cells, without altering the tissue integrity.展开更多
Rod-like molecules confined on a spherical surface can organize themselves into nematic liquid crystal phases. This can give rise to novel textures displayed on the surface, which has been observed in experiments. An ...Rod-like molecules confined on a spherical surface can organize themselves into nematic liquid crystal phases. This can give rise to novel textures displayed on the surface, which has been observed in experiments. An important theoretical question is how to find and predict these textures. Mathematically, a stable configuration of the nematic fluid corresponds to a local minimum in the free energy landscape. By applying Taylor expansion and Bingham approximation to a general molecular model, we obtain a closed-form tensor model, which gives a free energy form that is different from the classic Landau-de Gennes model. Based on the tensor model, we implement an efficient numerical algorithm to locate the local minimum of the free energy. Our model successfully predicts the splay, tennis-ball and rectangle textures. Among them, the tennis-ball configuration has the lowest free energy.展开更多
文摘The continuous model of liquid crystals and the corresponding symmetry are discussed, from which the expression of the density of free energy is deducted. Based on the transformation of vector field, four typical important ways of distribution of the vector field are discussed and the stable conditions of the distribution are induced.
基金supported by the National Natural Science Foundation of China(No.1017405790201011)+1 种基金the Key Project of Chinese Ministry of Education(No.2005-105148)the Research Fund for the Doctoral Program of Higher Education of China(No.20070613058)
文摘The V-shaped electro-optical properties control is investigated by an equivalent circuit model.Simu-lation results show that genuine V-shaped form is only observed at hysteresis inversion frequency,and be-low and above this frequency an anomalous and normal hysteresis are observed.And the inversion fre-quency decreases with the resistance of ferroelectric liquid crystal(FLC)layer following logf_i=-alogR_(LC)+b .The results are in good accordance with the reported experimental results.
基金Supported by Guangdong Science and Technology Project(2012B050600012)
文摘Dynamical properties of liquid in nano-channels attract much interest because of their applications in engineering and biological systems. The transfer behavior of liquid confined within nanopores differs significantly from that in the bulk. Based on the simple quasicrystal model of liquid, analytical expressions of self-diffusion coefficient both in bulk and in slit nanopore are derived from the Stokes–Einstein equation and the modified Eyring's equation for viscosity. The local self-diffusion coefficient in different layers of liquid and the global self-diffusion coefficient in the slit nanopore are deduced from these expressions. The influences of confinement by pore walls,pore widths, liquid density, and temperature on the self-diffusion coefficient are investigated. The results indicate that the self-diffusion coefficient in nanopore increases with the pore width and approaches the bulk value as the pore width is sufficiently large. Similar to that in bulk state, the self-diffusion coefficient in nanopore decreases with the increase of density and the decrease of temperature, but these dependences are weaker than that in bulk state and become even weaker as the pore width decreases. This work provides a simple method to capture the physical behavior and to investigate the dynamic properties of liquid in nanopores.
基金Supported by NIH Grant DK068097funds provided by Rhode Island Hospital+1 种基金the Deutsche Forschungsgemeinschaft grant (DFG) grant GE1193/1-1NIH COBRE Award (RR-P20 RR17695)
文摘AIM： To develop a method of labeling and microdissecting mouse Kupffer cells within an extraordinarily short period of time using laser capture microdissection （LCM）. METHODS： Tissues are complex structures comprised of a heterogeneous population of interconnected cells. LCM offers a method of isolating a single cell type from specific regions of a tissue section. LCM is an essential approach used in conjunction with molecular analysis to study the functional interaction of cells in their native tissue environment. The process of labeling and acquiring cells by LCM prior to mRNA isolation can be elaborate, thereby subjecting the RNA to considerable degradation. Kupffer cell labeling is achieved by injecting India ink intravenously, thus circumventing the need for in vitro staining. The significance of this novel approach was validated using a cholestatic liver injury model. RESULTS： mRNA extracted from the microdissected cell population displayed marked increases in colonystimulating factor-1 receptor and Kupffer cell receptor message expression, which demonstrated Kupffer cell enrichment. Gene expression by Kupffer ceils derived from bile-duct-ligated, versus sham-operated, mice was compared. Microarray analysis revealed a significant （2.5-fold, q value 〈 10） change in 493 genes. Based on this fold-change and a standardized PubMed search, 10 genes were identified that were relevant to the ability of Kupffer cells to suppress liver injury. CONCLUSION; The methodology outlined herein provides an approach to isolating high quality RNA from Kupffer cells, without altering the tissue integrity.
基金supported by National Natural Science Foundation of China(Grant Nos.21274005 and 50930003)
文摘Rod-like molecules confined on a spherical surface can organize themselves into nematic liquid crystal phases. This can give rise to novel textures displayed on the surface, which has been observed in experiments. An important theoretical question is how to find and predict these textures. Mathematically, a stable configuration of the nematic fluid corresponds to a local minimum in the free energy landscape. By applying Taylor expansion and Bingham approximation to a general molecular model, we obtain a closed-form tensor model, which gives a free energy form that is different from the classic Landau-de Gennes model. Based on the tensor model, we implement an efficient numerical algorithm to locate the local minimum of the free energy. Our model successfully predicts the splay, tennis-ball and rectangle textures. Among them, the tennis-ball configuration has the lowest free energy.
