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In vivo and in vitro studies reveal that Ursolic Acid (UA) is able to counteract endogenous and exogenous inflammatory stimuli and has favorable anti-inflammatory effects. The antiinflammatory mechanisms mainly include decreasing the release of histamine in mast cells, suppressing the activities of lipoxygenase, cyclooxygenase and phospholipase, and reducing the production of nitric oxide and reactive oxygen species, blocking the activation of the signal pathway, downregulating the expression of inflammatory factors, and inhibiting the activities of elastase and complement. These mechanisms can open up new avenues for the scientific community to develop or improve novel therapeutic approaches to tackle inflammatory diseases, such as arthritis, atherosclerosis, neuroinflammation, liver diseases, kidney diseases, diabetes, dermatitis, bowel diseases, cancer. The anti-inflammatory activity, the anti-inflammatory mechanism of ursolic acid and its therapeutic applications are reviewed in this paper.

Oleanolic acid can inhibit edema and exhibit obvious inhibitory activity to inflammatory by activating of the pituitary-adrenal cortical system, inhibiting the synthesis or release of PGs, inhibiting endotoxin-mediated release of HMGB1 by endothelial cells or regulating MAPK, PI3K/Akt/NF- κB/ICAM-1/JAK/STAT signaling pathways, etc. In recent years, an increased number of interesting research work has been carried out on the anti-inflammatory activity and mechanisms of OA derivatives, such as acyloxyimino derivative, 3-acetylated derivatives, novel 3,5-disubstituted isoxazoles derivatives, acetate, ester derivatives and oximes derivatives. The review summaries and highlights the updated advances on the anti-inflammatory activity and mechanism of OA and its derivatives.

Ginseng is a traditional medicine with a complex chemical composition, wide bioactivity and unique pharmacological action. Many studies have confirmed that ginsenosides are the active ingredients of ginseng, and ginsenosides have always been the focus of different researchers. With the development of modern separation and analysis technology, more than 150 kinds of ginsenosides have been isolated. The ginsenosides Rb1, Rb2, Rc, Rg1 and Re account for more than 80% of total ginsenosides, and other saponins, such as Rd, Rg3 and Rh2, which are minor constituents, accounting for only a small portion of the total amount. In recent years, ginsenosides have been found to possess strong pharmacological activities, such as antioxidation, clearing of oxygen free radicals, reducing calcium overload and anti-apoptosis. Ginsenosides play a protective role in ischemia-reperfusion injury. This paper reviews the protective effects of ginsenosides on myocardial ischemia and ischemiareperfusion injury.

C34H56O6⋅0.25(C4H8O2), orthorhombic, P212121 (no. 19), a = 8.17152(14) Å, b = 17.6728(3) Å, c = 23.1916(5) Å, V = 3349.18(11) Å3, Z = 4, R gt(F) = 0.0416, wR ref (F 2) = 0.1143, T = 293 K.

C18H17NO3, triclinic, P 1 ‾ $P‾{1}$ (no. 2), a = 7.3950(5) Å, b = 8.6697(5) Å, c = 11.6813(9) Å, α = 85.457(6)°, β = 76.712(6)°, γ = 82.759(5)°, V = 722.07(9) Å3, Z = 2, R gt (F) = 0.0502, wR ref (F 2) = 0.1342, T = 99.9(3) K.

C 20 H 14 F 6 O 2 ${\text{C}}_{20}{\text{H}}_{14}{\text{F}}_{6}{\text{O}}_{2}$ , monoclinic, P21/c (no. 14), a = 14.791(2) Å, b = 8.5303(9) Å, c = 15.531(3) Å, β = 115.474(19)°, V = 1769.1(5) Å3, Z = 4, R g t ${R}_{gt}$ (F) = 0.0574, w R ref $w\,{R}_{\text{ref}}$ (F 2) = 0.1451, T = 100 K. CCDC no.: 2016723

C31H48O5, monoclinic, P21 (no. 4), a = 11.0421(3) Å, b = 6.49710(16) Å, c = 20.4687(4) Å, β = 97.922(2)°, V = 1454.45(6) Å3, Z = 2, R gt(F) = 0.0382, wR ref(F 2) = 0.1024, T = 293(2) K.

C30H52O3, orthorhombic, P212121 (no. 19), a = 6.71147(14) Å, b = 16.6565(4) Å, c = 25.0815(6) Å, V = 2803.85(11) Å3, Z = 4, R gt (F) = 0.0405, wR ref (F 2) = 0.1092, T = 293(2) K.

We design two novel d10 metal complexes [Zn(3-qlc)2]n (Zn1), [Cd(3-qlc)2]n (Cd1) (3-Hqlc = quinoline-3-carboxylic acid), which display similar 2D layer structures, and further form 3D 6-connected primitive cubic (pcu) network topology via π⋯π stacking interactions with the point symbol {412·63}. Complexes Zn1 and Cd1 exhibit tunable luminescence and photovoltaic properties as a new type of multifunctional materials. Zn1 and Cd1 show tunable luminescence from blue to green by varying the temperature in the solid state. What's more, both of them exhibit excellent aggregation-induced emission (AIE) properties in DMSO/water mixtures. Encouraged by the UV-visible absorption in an ethanol solution result, Zn1 and Cd1 can be considered as co-sensitizers in combination with N719 to investigate their effect on enhancing the dye-sensitized solar cells (DSSCs) performance. Zn1 and Cd1 could overcome the deficiency in the ruthenium complex N719 absorption in the ultraviolet and blue-violet region, offsetting competitive visible light absorption of I3− and reducing the charge recombination of injected electrons. After being co-sensitized with Zn1 and Cd1, the devices co-sensitized by Zn1/N719 and Cd1/N719 yield an overall efficiency of 7.75% and 7.70%, which are 44.59% and 43.66% higher than that of the device sensitized only by N719 (5.36%).

The near-infrared nonvolatile holographic recording has been realized in a doubly doped LiNbO3:Fe:Rh crystal by the traditional two-center holographic recording scheme, for the first time. The recording performance of this crystal has been investigated by recording with 633 nm red light, 752 nm red light and 799 nm near-infrared light and sensitizing with 405 nm purple light. The experimental results show that, co-doped with Fe and Rh, the near-infrared absorption and the photovoltaic coefficient of shallow trap Fe are enhanced in this LiNbO3:Fe:Rh crystal, compared with other doubly doped LiNbO3 crystals Such as LiNbO3:Fe:Mn. It is also found that the sensitizing light intensity affects the near-infrared recording sensitivity in a different way than two-center holographic recording with shorter wavelength, and the origin of experimental results is analyzed. (C) 2007 Elsevier GrnbH. All rights reserved.

The instantaneous preferential domain nucleation effect of the z-cut hafnium-doped congruent LiNbO 3 crystal is investigated. The beam from an Ar-ion laser with 514 nm wavelength is focused on z surface. Two incidence schemes are performed: (1) irradiating near and focusing on the +z surface; (2) irradiating near and focusing on the -z surface. The digital holographic interferometry is used in investigating the visible laser-induced domain nucleation in hafnium-doped congruent LiNbO 3 crystal, and reconstructs the phase shift of new domain. From the investigation of phase shift induced by the domain inversion, the analysis of domain nucleation is performed. When the electric field exceeds a certain threshold value, the preferential domain nucleation is achieved instantaneously at the focal spot during the combined actions of irradiation and external fields. The nucleation fields have a systematic decrease with increasing laser intensity, and reach an effective saturation at higher intensities. The reduction proportions obtained in the second scheme are lower than those in the first one with the same intensity, and the saturation values at higher intensities are the same in both schemes. We attribute the instantaneous effect of laser-induced domain nucleation to the space charge field, and the saturation value at higher intensities is related to the saturation of the space charge field. The formation of instantaneous effect and corresponding physical explanation based on space charge field are present.

The phase-mapping of domain wall kinetics under the uniform st eady-state electric field is achieved and investigated in the LiNbO 3 crystals by the digital holographic interferometry. We obtained the sequences of reconstructed three-dimensional and two-dimensional wave-field phase distributions during the electric poling in the congruent and near stoichiometric LiNbO 3 crystals. The phase-mapping of domain wall mo tions in the two crystals are obtained. Both the phase relaxation and the pinning-depinning mechanism are observed during the domain wall motion. The residual phase distribution is observed after the high-speed domain wall motion. The corresponding analyses and discussions are proposed to explain the phenomena. Keywords: phase-mapping, domain wall kinetics, lithium ni obate, digital holographic interferometry 1. Introduction With the large electro-optic and nonlinear optical coefficients, lithium niobate has become one of the most important and widely applied optical materials. The domain engineering in the LiNbO

The double threshold effect of ultraviolet laser-induced preferential domain nucleation in near stoichiometric LiTaO3 is observed. The continuous ultraviolet laser beam (351 nm) is focused on the -z surface of the wafer, and the homogeneous electric field is applied simultaneously antiparallel to the direction of spontaneous polarization along the z axis. The double threshold effect includes both the primary and the secondary thresholds. The primary threshold is the minimum intensity to achieve the instantaneous preferential domain nucleation within the focus by the combined action of irradiation and electric fields. Below the dark nucleation field, the instantaneous preferential domain nucleation is achieved within the illuminated area when the intensity exceeds the primary threshold. The experiments prove that the domain inversion can be locally controlled by the laser irradiation. The secondary threshold is the minimum intensity to achieve the memory effect without any irradiation within the original focus. The memory effect of preferential nucleation is observed when the intensity is below the primary threshold and above the secondary threshold. The preferential domain nucleation of memory effect is investigated. The different physical explanations are presented for the instantaneous effect and memory effect. The space charge field created by the photoionization carriers is thought to be responsible for the instantaneous effect. The explanation based on the formation and transformation of extrinsic defect is presented for the memory effect.

In this paper, within the spectrum range from 351 nm to 799 nm, the different reductions of nucleation field induced by the focused continuous irradiation with different light intensity are achieved in congruent LiNbO 3 crystals. The reduction proportion increases exponentially with decreasing the irradiation wavelength, and decreases exponentially with increasing the irradiation wavelength. Basing on photo-excited effect, we propose a proper model to explain the mechanism of light-induced domain nucleation in congruent LiNbO 3 crystals.

The dynamic and static measurements of phase variation induced by domain inversion are performed in congruent lithium niobate crystal by the digital holographic interferometry. The existence of ridge-shape phase distribution adjacent to 180° domain wall is observed. During the domain wall motion, the phase variations are not uniform but have obvious relaxations. In the static measurement, the ridge elevation can vary linearly with the uniform electric field. The reasonable assumptions are proposed to explain these effects. The phase contrast across the crystal thickness induced by the internal field is also measured by the digital holographic interferometry just after the congruent lithium niobate crystal is partially poled. The direction of applied external field is antiparallel to that of internal field, and the measured phase contrast varies linearly with the applied external field. A new internal field is obtained by this method, and named effective internal field. The distinct discrepancy between effective and equivalent internal fields is observed. We attribute this effect to the new macroscopic representation of elastic dipole components of defect complex in the crystal.

The domain inversion and electrochromism in congruent RuO 2 :LiNbO 3 crystals are investigated at room temperature, and the relations between them are proposed. During electric poling process, the electrochromism accompanies the ferroelectric domain inversion simultaneously, and is localized to the same region with domain inversion. As domain inversion, the electrochromism is completely reversible when the domain is inverted from the reverse direction. The properties, coincidence and localization, between domain inversion and electrochromism are proved solidly by the digital holographic interferometry, the real-time measurement of optical transmittance change and poling current, and the micrographic analysis after being etched in hydrofluoric acid. The influences of annealing conditions on electrochromism are also discussed. We provide the reasonable assumptions and analyses that the charge redistribution within the crystal caused by domain inversion is the source for electrochemically oxidation and reduction of Ru ion, and the intervalence electron transference between Ru 4+ and Ru 3+ plays a key role in the spectrum shift within different spectral range by the change of the photon absorption.

In this paper, the theory model in which both the two-center material equations and two-dimensional two-wave coupled equations were solved jointly based on two-center holographic recording method is presented to analysis the dynamic formation of the crossed-beam photorefractive gratings in two doped LiNbO 3 crystals. The influence of the light intensity on the basic holographic properties of the crossed-beam photorefractive gratings in LiNbO 3 :Fe:Mn crystals is explored. The numerical simulation results are presented. The investigation yields quantitative predictions of the expected behavior of the dynamics of these gratings, which can be useful for the design of finite boundary photorefractive holographic optical elements.

In order to obtain the two dimensional distribution of the refractive index changes due to the domain inversion in the RuO 2 :LiNbO 3 crystal, we make use of the Mach-Zehnder interferometer system to record holograms, with the object light transmitting through the poling RuO 2 :LiNbO 3 crystal, and then filter the spectrum in the frequency domain to get the object light spectrum for numerically reconstructing the object wavefront. The results confirm that the electro-chromic effect region well agrees with the domain inversion region in RuO 2 :LiNbO 3 crystal.

Significant improvements of photorefractive properties such as diffraction efficiency with 90-degree holographic recording geometry have been obtained by the application of external electric fields. Experimental results show that the highest diffraction efficiency can be obtained at least 3 times than without external electric field in Fe-doped LiNbO 3 crystals. The vectorial Kukhtarev equations are modified in single center model taking into account the directions of optical axis and external electric field. The photorefractive properties of single doped LiNbO 3 :Fe crystal using 90-degree storage geometry are theoretically investigated by jointly solving the vectorial material equations and the two dimensional coupled wave equations. The variation trends of the theoretical results are similar to the experimental results.

A Bragg grating focusing device composed of electro-optically induced refractive index grating in periodically poled lithium niobate was designed for integrated optics systems. The device are induced and controlled by the application of an external electric field. The theoretical analysis of the proposed optical device is carried out using two-dimensional coupled wave theory. The focusing properties and the diffraction intensity are investigated at the focal plane. It is shown that the designed device has good performance of focusing when a plane wave incidents on it at a certain angle. This type of Bragg diffraction devices can be act as a focusing lens and will have many potential applications such as in integrated optics and opto-electronics.

Dopants in doubly doped lithium niobate crystals are crucial for properties of nonvolatile holographic recording. In our experiments, a series of possible doubly doped congruent LiNbO3:Fe:X (X=Mn, Cu, Rh, Ru, Ni) are proposed and investigated for nonvolatile holographic recording. The experimental results demonstrate that the dopants with different distances of energy band to conduction band have different recording efficiency. Further analysis approve that the dopants which have moderate energy-band distance to conduction band can perform recording with both high diffraction efficiency and long lifetime. The compared results show that LiNbO3:Fe:Ni is promising for nonvolatile holographic recording, and its recording conditions are optimized.

Holographic recording experiments of doubly-doped LiNbO 3 :Fe:Ni crystals were conducted by three kinds of different two-color recording schemes. The results show that the saturation diffraction efficiency, the fixing diffraction efficiency, and the recording sensitivity of oxidized LiNbO 3 :Fe:Ni crystal are higher than those of other reported doubly-doped LiNbO 3 crystals. Based on the doped energy-band diagram, the effect of microcosmic optical parameter of the deep trap center on holographic recording properties of doubly-doped LiNbO 3 is analyzed theoretically. LiNbO 3 :Fe:Ni has the potential of being a new highly efficient nonvolatile holographic recording material.

In this paper two-beam interference experiments are performed to investigate the diffraction characteristics of volume gratings in Fe:LiNbO 3 crystals (0.15wt% Fe 2 O 3 ), the results show that the dependence of the diffraction characteristics on the oxidization-reduction state and the oscillatory diffraction can be found in the reduced crystals. The theoretical analysis shows that the strongest space charge field can be formed in the reduced crystals, which induce the strong refractive index change, and because of the sin 2 relation between refractive index change and diffraction efficiency, the oscillatory diffraction can be found in the reduced crystals. In application for high diffraction efficiency the oxidized treatment should be performed for Fe:LiNbO 3 crystals so that the depth integral of saturated refractive index change is equal to π/2.

In this paper, a very effective recording technique of optimal recording/fixing switching time induced by high-coupling effect is considered for high diffraction efficiency of local nonvolatile holographic gratings in LiNbO3:Ce:Cu crystals. The fixed diffraction efficiencies gained by optimal switching time are up to 100% in theoretical simulations and 78% in experiments. It provides a new idea to obtain high persistent diffraction efficiency. Finally, as one of examples for design of 3-D optical integrations by local nonvolatile holographic gratings, a new type of volume holographic grating lenses for converting a plane wave to a lateral-spread spherical wave and vice versa, is illustrated.

An effective technique of direct recording with UV beams for high sensitivity during nonvolatile holographic storage in LiNbO3:Ce:Cu crystals is proposed and investigated. Just contrary to the usual recording scheme in which red beams are used for writing while UV light is for sensitizing, in this paper two mutual coherent UV beams of 365 nm are used to directly record gratings in two trap centers simultaneously with illumination of a red light, and the finally remained grating in deeper centers is insensitive to red light for further readout. High sensitivity of 0.31 cm/J is gained in our experiments, which is about two orders of magnitude greater than that gained by the conventional technique. A unique characteristic inherent in this recording technique which is in phase between two gratings recorded in two trap centers is demonstrated and its function of improving diffraction efficiency is analyzed.

Doubly-doped LiNbO3:Fe:Ni crystals have been grown by Czochralski technique. The transmission spectrum and the effect of light-induced absorption change by ultraviolet (UV) illumination are measured. Nonvolatile holographic storage is realized by red light (633 nm) recording and UV (365 nm) sensitizing. The results show that the saturation diffraction efficiency, the fixing diffraction efficiency, and the recording sensitivity of oxidized LiNbO3:Fe:Ni crystals are higher than those of other reported doubly-doped LiNbO3 crystals. Besides, the nonvolatile holographic recording can't be realized by green light (514 nm) recording and UV light (365 nm) sensitizing. LiNbO3:Fe:Ni has the potential of being a new highly efficient nonvolatile holographic recording material.

We have investigated the oscillatory behavior of diffraction efficiency under ultraviolet-light-recoring experimentally and theoretically. We utilized a model in which electrons and holes can be excited from impurity centers in the ultraviolet region to study the oscillatory behavior of the diffraction efficiency. On the basis of the material equations and the coupled-wave equations, we found that the oscillating behavior is due to the oscillation of the relative spatial shift, not the large space-charge field. And the electron-hole competition may cause the oscillating behavior of spatial phase shift ? and the reduction of space-charge field Esc.

Scattering noise in four kinds of lithium niobate crystals of the same doubly doping system (they are LiNbO3:Fe:Mn, LiNbO3:Ce:Mn, LiNbO3:Ce:Cu and LiNbO3:Fe:Cu) is observed during nonvolatile holographic recording. The results show that nonvolatile holographic recording can effectively suppress scattering noise and this kind of suppression effect is decided by the recombination coefficients of the dopants in the shallower and the deeper centers, respectively. It is concluded that small recombination coefficients of the shallower centers and large recombination coefficients of the deeper centers benefit the amplification of the signal grating and the suppression of the noise grating. In addition, the initial seed scattering noise also impacts the finally suppressed scattering noise and little initial seed scattering leads to low scattering noise after recording. In a conclusion, the performances of LiNbO3:Ce:Cu is the best with high diffraction efficiency and low scattering noise. The theoretical simulations are performed for validation. It provides a fundamental method to the problem of scattering noise intrinsic into the nonvolatile holographic recording.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The phase mapping of domain kinetics under the uniform steady-state electric field is achieved and investigated in the LiNbO3 crystals by digital holographic interferometry. We obtained the sequences of reconstructed three-dimensional and two-dimensional wave-field phase distributions during the electric poling in the congruent and near stoichiometric LiNbO3 crystals. The phase mapping of individual domain nucleation and growth in the two crystals are obtained. It is found that both longitudinal and lateral domain growths are not linear during the electric poling. The phase mapping of domain wall motions in the two crystals is also obtained. Both the phase relaxation and the pinning-depinning mechanism are observed during the domain wall motion. The residual phase distribution is observed after the high-speed domain wall motion. The corresponding analyses and discussions are proposed to explain the phenomena.

The primary and secondary threshold intensities of ultraviolet-laser-induced preferential domain nucleation in nearly stoichiometric LiTaO3 is observed. The primary threshold is the minimum intensity to achieve the instantaneous preferential domain nucleation within the focus by the combined action of irradiation and electric fields. The secondary threshold is the minimum intensity to achieve the memory effect without any irradiation within the original focus. The space charge field created by the photoionization carriers is thought to be responsible for the instantaneous effect. The explanation based on the formation and transformation of extrinsic defect is presented for the memory effect.

A reversible electrochromic effect during the electrical poling process in LiNbO3:Ru:Fe crystals at room temperature is observed. In electrode area, both electrochromism and domain-inversion occur mutually and electrochromism is reversible during back-switch poling, which are experimentally verified, and a microstructure model to explain the mechanism is proposed. In addition, different from the undoped LiNbO3 crystals, the breakdown field (>25.0kV∕mm) is higher than the coercive (21.0kV∕mm) measured in LiNbO3:Ru:Fe, which proves a possible new technique to realize domain-inversion by constant electric field rather than pulsed one.