Real-time detection of NAD(P)H is particularly important for understanding physiological activities of neutrophils. We scrutinize the erformance of weak light detection systems with electron multiplying CCDs (EMCCDs) with regard to the feasibility of valid investigations by tofluorescence NAD(P)Hin single human neutrophils. The low-noise amplification facility of EMCCDs is indeed just adequate to permit detection at an irradiation level where neither quenching nor phototoxic effects occur. For demonstration, a neutrophil respiratory burst was triggered and observed in real time. Our low-intensity detection system fulfills all requirements for real-time investigations at high spatiotemporal resolution in the field of neutrophil physiology and pathology.

PMA-induced respiratory burst neutrophils were exposed to exogenous nitric oxide (NO) donor sodium nitroprusside (SNP) to study the effect of NO on calcium signaling. A sharp rise of cytosolic calcium concentration ([Ca2+]c) was triggered by 1 mM SNP with and without external calcium. We found that GF 109203X, a specific inhibitor of protein kinase C, DPI, a putative inhibitor of the respiratory burst-generating NADPH oxidase, and 2-DG, a non-metabolizable analog of glucose, completely inhibited the SNPinduced rise of [Ca2+]c in PMA-activated respiratory burst neutrophils. Meanwhile, 2-APB and TMB-8, two potent IP3 receptor inhibitors, prevented calcium increase respectively. Furthermore, N-ethylmaleimide (NEM), a specific cysteine alkylating agent, evidently abolished the [Ca2+]c elevation. In contrast, the sGC inhibitor NS2028 had little effect on the rise of [Ca2+]c. Taken together, these results indicated that exogenous NO induced the release of calcium from intracellular IP3 receptor-sensitive stores of neutrophils via S-nitrosylation in a respiratory burst-dependent manner.

Femtosecond laser ablation of silver plate placed in water is used to produce nanoparticle suspension. The method is easy to operate and the suspension is relatively stable. The optical properties and the size distribution of the suspension are studied with UV-vis absorption spectroscopy and dynamic light scattering, respectively. The shape of the nanoparticles is investigated by an atomic force microscope, which is near spherical. There are two kinds of nanoparticles, small particles with diameter about 35 nm, and large particles with diameter about 120 nm.

Normalized Mandel Parameter <Q> is introduced as a new measurement of photon statistics. Dependences of Mandel parameter and corresponding ormalized Mandel parameter<Q> on photon-counting time interval are experimentally investigated for pseudo-thermal light. We demonstrate that <Q> is more appropriate than to measure the statistical deviation from Poisson distribution, because <Q> presents clearly both the intrinsic statistical properties and measuring effects. The advantages of <Q> in charactering nonclassical emissions are also discussed.

We propose a novel type of unitary matrix for phase-code multiplexed holographic memories, which could be quickly generated from geometric sequences. Our analysis shows that the phase-code matrices are unitary rather than orthogonal. The new matrices have complex elements. The order of unitary matrices can be any positive integer, so that we can accommodate the available spatial light modulators to obtain the maximum possible storage capacity. The cross-talk noises in phase-encoded memories with unitary matrices and with Hadamard matrices are of the same order of magnitude, which are much lower than those in holographic memories with wavelength multiplexing or angle multiplexing.

Forward degenerate four-wave mixing (DFWM) processes are investigated with a femtosecond pulsed laser in lithium niobate crystal doub/y-doped with magnesium and iron (LiNb03:Fe,Mg). The pulse energy dependence reveals a pure third-order nonlinear response, and the third-order nonlinear susceptibility X(3) in the material is evaluated to be 4.96 x 10-13 esu. The time-resolved DFWM process shows a response time of X(3) shorter than lOOfs, which is due to the nonresonant electronic nonlinearities. Our results indicate that LiNb03 crystals have potentials for ultrafast real-time optical processing systems, which require a large and fast X(3) optical nonlinearitrr.

In this work we studied photorefractive effect of lithium niobate sLiNbO3d doped with Zn, In, and Na at ultraviolet sUVd wavelength down to 351 nm. It is found that the UV photorefraction of LiNbO3 doped with Zn, In, or Na was enhanced significantly as compared to that of the nominally pure LiNbO3. Our results show that the statement that the property of resistance against photorefraction in highly Zn and In doped LiNbO3 is correct only in visible light range. By contrary, these crystals exhibit as excellent photorefractive characteristics in UV. We also find that there are doping concentration threshold values of Zn and In for the disappearance of the light-induced lens-like effect both in visible and in UV, but such concentration threshold values are not found for UV photorefraction within the highest doping concentrations we used. In highly Zn or In doped LiNbO3 crystals, diffusion dominates over photovoltaic effect and electrons are determined to be the dominant charge carriers in UV photorefraction. The results are of interest to the study on the defect structure of LiNbO3. Further investigation on this field is greatly urgent.

The supramolecular polypseudorotaxane (3) with π-conjugated polyazomethine is directly synthesized by the polycondensation of two simple inclusion complexes of β-cyclodextrin/o-tolidine (1) and β-cyclodextrin/p-phthaldehyde (2) and is comprehensively characterized by NMR, FTIR, circular dichroism spectra, powder X-ray diffraction, thermogravimetric (TG) and differential thermal analysis (DTA), scanning electron icroscopy (SEM), and scanning tunneling microscopy (STM) both in solution and in the solid state. The results obtained have revealed linear microstructure of polypseudorotaxane 3 and different photophysical behavior as compared with the ð-conjugated polyazomethine backbone (4). The present investigations prove a simple method for preparing supramolecular polypseudorotaxane by different complexes, which possess the potential to serve as molecular devices/machines and optical materials.