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We present a simple system for realizing single-shot ultrafast sequential imaging based on spatial multiplexing in-line holography. In this system, we propose to combine a specially designed mini-reflector delay-line array with digital in-line holography. The former including a group of adjustable mini-reflectors can easily generate an array of probe sub-pulses that can be controlled independently in the propagation direction and time delays. The object beams formed by the different sub-pulses will propagate and fall on different recording regions of the image sensor to generate a single-shot spatial-multiplexing in-line hologram. The geometry of the digital in-line holography can simplify the complexity of the system and enable complex amplitude imaging. In addition, the time resolution of this system is limited only by the pulse duration, which allows this system to study the dynamic processes with the femtosecond order. In an experiment about the laser-induced air plasma, our proposed system achieves nine frames sequential holographic images with the frame rate of 7.5 trillion frames per second (Tfps).

We present a new, to the best of our knowledge, type of off-axis digital holographic imaging method with a long field of view (FOV). In the method, the pre-magnification recording geometry is realized by a cylindrical lens (CL) or cylindrical beam instead of a conventional objective or spherical beam in traditional off-axis digital holography (DH). At the same time, the reference beam is replaced by a divergent cylindrical beam. Theoretical analysis and experiments have justified that, in off-axis DHs, the adoption of the cylindrical beams can realize a one-dimensional pre-magnification of the object beam only in the off-axis direction to satisfy the bandwidth constraint, and at the same time the FOV of the reconstructed image in the orthogonal direction can remain unaffected. In comparison with existing off-axis DHs, this cylindrical wave-based DH (CWDH) method has a distinct advantage in expanding the FOV of the reconstructed image. The FOV feature of the CWDH makes it especially suitable for applications that require a long FOV such as imaging samples in microfluidic channels.

Birefringence is an important optical property of anisotropic materials arising from anisotropies of tissue microstructures. Birefringence parameters have been found to be important to understand optical anisotropic architecture of many materials and polarization imaging has been applied in many researches in the field of biology and medicine. Here, we propose a scheme to miniaturize a double-channel polarization holographic interferometer optics to create a polarization holographic microscope slide (P-HMS) suitable for integrating with microfluidic lab-on-a-chip (LoC) systems. Based on the P-HMS combined with a simple reconstruction algorithm described in the paper, we can not only simultaneously realize holographic imaging of two orthogonal polarization components of dynamic samples in a microfluidic channel but also quantitative measurement of 2D birefringence information, both including the birefringence phase retardation and optic-axis orientation. This chip interferometer allows for off-axis double-channel polarization digital holographic recording using only a single illumination beam without need of any beam splitter or mirror. Its quasi-common path configuration and self-aligned design also make it tolerant to vibrations and misalignment. This work about the P-HMS could play a positive role in promoting the application of birefringence imaging in microfluidic LoC technology.

In this study, we propose a compact four-channel angular-multiplexing polarisation holographic microscope to quantify the spatially resolved Jones matrix of a dynamic sample in a microfluidic channel. To make the imaging system compact, a common-path off-axis configuration based on a simple object and a reference beam generator unit, consisting of a Wollaston prism and a converging lens, was introduced in the holographic microscope. Using this system and the retrieval method described in this paper, the spatially resolved Jones matrix parameters, as well as the polarisation information, including the diattenuation and phase retardation, of the target sample could be simultaneously retrieved from a single-shot hologram. We experimentally demonstrated the feasibility of our method by quantitatively measuring the birefringence parameters of a quarter-wave plate and extracting the 2-D Jones matrix and polarisation parameters of potato starch particles and C. elegans worms. The simple optical structure and common-path design reduce the system requirements for light source coherence and system stability, which provides a feasible approach for the development of a portable polarisation holographic microscope for microfluidics.

Stimulated emission depletion (STED) microscopy has been widely applied in single-cell and single-molecular studies benefiting from its ability of super-resolution imaging. However, it is challenging to perform STED imaging in highly scattering media, such as biological tissues, due to high scattering, which destroys the structured illumination beams. Here, we present a technique to produce the desired illumination beams beyond high scattering for STED microscopy. A dual-wavelength transmission matrix method is employed for shaping the excitation beam and the STED beam simultaneously, achieving the temporal and spatial overlap of the two beams behind a scattering medium. Experimentally, the overlapped foci were constructed by using a digital micromirror device (DMD). The extinction ratio of the STED focus reaches −23.8 dB, which compares favorably to the oft-quoted desirable value for STED applications. In particular, raster scanning of overlapped foci and the switching of the STED focus were demonstrated by adopting the fast switching ability of the DMD. Construction of the illumination beams beyond scattering will benefit STED microscopy in deep tissues.

A setup for the generation of arbitrary vector beams is proposed. The setup mainly consists of a spatial light modulator (SLM), an angle-adjustable polarization beam splitter modulator, and a spatial filtering imaging system. Compared with the system using a birefringent beam splitter with a non-adjustable splitting angle, the polarization splitting angle of the improved setup can be adjusted by slightly rotating the related mirrors, which will bring more convenience when different wavelengths and different pixel sizes of SLMs are involved. The experimental results also demonstrate that the setup possesses a good polarization-selective imaging ability, which reveals that the setup may also be useful in polarization-selective spatial filtering imaging and polarization-encoded encryption.

We propose a quantitative phase imaging system with exact slightly-off-axis configuration and suitable for objects both smaller and larger than the size of the effective recording region of the image sensors. In this system, the object is illuminated by a convergent spherical beam and a specially designed aperture filter is placed on the spatial frequency plane of the object wave; at the same time, a point source emitting from the edge of the aperture is taken as the reference beam, so that the optimal frequency condition for reconstruction of slightly-off-axis digital holograms can be always guaranteed for both large and small objects as well as different magnification (or the field of view) configurations. At the same time, a 1x2 single-mode optical fiber splitter is used for generating the reference and the illumination beams. Benefited from such fiber-based slightly-off-axis design, the proposed system provides a low-cost way to convert a regular microscope into a slightly-off-axis holographic one for microbiological specimens with a high spatial resolution.

We present an approach for design of Fresnel zone plates (FZPs) with different focusing manners. By re-performing the formula for calculating the half-wave zones of a conventional FZP into wave vector domain, we get a wave vector integral formula, by which the half-wave zones of a generalized FZP could be derived from the wave vector distribution of the expected focusing beams. As examples, we analyzed the situations with, respectively, a circular focusing manner and a line focusing manner, and successfully derived, for the first time to our knowledge, the analytic expressions for calculating the corresponding half-wave zones of the expected FZPs. Some simulations in X-ray domain demonstrated the feasibility of the method and the derived formulas.

This study aimed to compare the efficacy and safety of rituximab (RTX) plus recombinant human thrombopoietin (rhTPO) with RTX alone in patients with immune thrombocytopenia (ITP) who had failed to respond to corticosteroids or relapsed. Recruited patients were randomized at a ratio of 2:1 into 2 groups: the combination group (RTX + rhTPO, n = 77) and the monotherapy group (RTX, n = 38). Overall response was achieved in 79.2% of patients in the combination group vs 71.1% in the monotherapy group (P = .36), and the complete response (CR) rate was 45.4% in the combination group compared with 23.7% in the monotherapy group (P = .026). The combination group had significantly shorter time to response (TTR; median and range, 7 and 4-28 days) compared with the monotherapy group (28 and 4-90 days) (P < .01). There was no difference between these 2 groups in terms of the long-term response (P = .12). Our findings demonstrated that the combination of RTX and rhTPO significantly increased the CR rate and shortened TTR compared with RTX monotherapy in the treatment of corticosteroid-resistant or relapsed ITP but failed to show a beneficial effect on the long-lasting response. This study is registered at www.clinicaltrials.gov as #NCT01525836.

We propose a double-channel angular-multiplexing polarization holographic imaging system with common-path and off-axis configurations. In the system, its input plane is spatially divided into three windows: an object window and two reference windows, and two orthogonal linear polarizers are attached, respectively, on the two reference windows; a two-dimensional cross grating is inserted between the input and output planes of the system. Thus the object beam passing through the object window and the two orthogonal polarized reference beams passing through the two reference windows can overlap each other at the output plane of the system and form a double-channel angular-multiplexing polarization hologram (DC-AM-PH). Using this system, the complex amplitude distributions of two orthogonal polarized components from an object can be recorded and reconstructed by one single-shot DC-AM-PH at the same time. Theoretical analysis and experimental results demonstrated that the system can be used to measure the Jones matrix parameters of polarization-sensitive or birefringent materials.

A time-resolved holographic polarization microscopy, based on angular multiplexing holographic technique, is proposed for imaging ultrafast phenomena in polarization-sensitive transparent materials. This method can retrieve and image the complex amplitude distributions of two orthogonal polarization components of two sequential vector wavefronts with ultrashort time interval by a single short recording. Some experimental results for imaging the pulse laser induced ultrafast events based on the method are given. It is demonstrated that this technique may provide a potential tool for characterizing ultrafast processes in polarization-sensitive materials, especially in the non-reproducible experiment conditions.

We report a fiber-based lensless holographic imaging system to realize a single-shot measurement of two dimensional (2-D) Jones matrix parameters of polarization-sensitive materials. In this system, a multi-source lensless off-axis Fresnel holographic recording geometry is adopted, and two optical fiber splitters are used to generate the multiple reference and illumination beams required for recording a four-channel angular-multiplexing polarization hologram (AMPH). Using this system and the method described in this paper, spatially resolved Jones matrix parameters of a polarization-sensitive material can be retrieved from one single-shot AMPH. We demonstrate the feasibility of the method by extracting a 2-D Jones matrix of a composite polarizer. Applications of the method to measure the Jones matrix maps of a stressed polymethyl methacrylate sample and a mica fragment are also presented. Benefit from the fiber-based and lensless off-axis holographic design, the system possesses a quite compact configuration, which provides a feasible approach for development of an integrated and portable system to measure Jones matrix parameters of polarization-sensitive materials.

A wavefront sensing method based on a spatial light modulator (SLM) and an incremental binary random sampling (IBRS) algorithm is proposed. In this method, the recording setup is built just by a transmittance SLM and an image sensor. The tested wavefront incident to the SLM plane can be quantitatively retrieved from the diffraction intensities of the wavefront passed through the SLM displaying a IBRS pattern. Because only two modulation states (opaque and transparent) of the SLM are used, the method does not need to know the concrete modulation function of the SLM in advance. In addition by introducing the concept of the incremental random sampling into wavefront sensing, the adaptability of phase retrieving based on the diffraction intensities is significantly improved. To the best of our knowledge, no previous study has used this concept for the same purpose. Some experimental results are given for demonstrating the feasibility of our method.

An algorithm for retrieval of the complex amplitude of the recorded object in blind two-step phase-shifting interferometry is proposed, in which the complex amplitude of the object wave can be found out directly from the recorded intensity patterns without the process of extracting the phase-shifting value in advance. A simple analytical formula for calculating the complex amplitude (including both the amplitude and the phase) of the object wave based on the recorded intensities is derived. Both the theoretical analysis and experimental results demonstrated the feasibility of this kind of blind phase-shifting algorithm in small phase shift situations.

A compact system for single-shot sequential holographic imaging (SSSHI) with high temporal resolution and a large field of view is proposed. In this system, a specially designed sequence pulse train generator with a group of diffractive gratings inserted is adopted to simultaneously generate the probe pulse train and the reference pulse train required for recording a single-shot spatial frequency division multiplexing hologram. The system successfully overcomes the walk-off effect of the ultrashort pulse laser in SSSHI and, hence, effectively avoids the influence of the short coherence of ultrashort pulses on the spatial resolution (or field of view) of SSSHI; the complexity of the system and the difficulty in the precise synchronous alignment of the probe and the reference pulses also can be greatly reduced. An experimental setup of the system was constructed, and a SSSHI of dynamical air plasmas induced by a femtosecond pulse laser is successfully realized.

A method for realizing 2D single-shot measurements of birefringence parameters (including both retardation and optic axis orientation) of anisotropic materials using a simple recording setup and an efficient processing algorithm is proposed. The recording setup can be built simply by inserting a circular polarizer and a polarization beam splitter, respectively, in the object path and reference path of a conventional off-axis holographic imaging system, with no need for other adjustments. An algorithm for quantitatively retrieving the birefringence parameters from one single-shot hologram is proposed and demonstrated, in which a new quantity describing the birefringence, called complex birefringence parameter, is introduced, and a set of formulas used to extract the birefringence parameters is derived. Some experimental results are given for demonstrating the feasibility of the method that reveal that the method may provide another effective approach for investigating the birefringence properties of dynamic anisotropic materials, especially the birefringence induced by ultrafast pulse lasers.

Thalidomide (THD) is an immunomodulatory agent used to treat immune-mediated diseases. Immune thrombocytopenia (ITP) is an autoimmune disorder in which impaired mesenchymal stem cells (MSCs) are potentially involved. We demonstrated that MSCs in ITP patients had reduced proliferative capacity and lost their immunosuppressive function, which could be corrected with THD treatment. According to the gene profile, the downregulation of caspase-8 and caspase-10, and upregulation of oct3/4 and tgf-β1, may be associated with THD modulation. Dendritic cells (DCs) played an important role in mediating the inhibitory activity of MSCs. To study the functional alteration of DCs elicited by MSCs, we sorted DCs after incubation with MSCs and performed T-lymphocyte reaction assays. The THD-modulated MSCs from ITP patients induced mature DCs to become tolerogenic DCs, whereas unmodulated MSCs had no effect. The induction of tolerogenicity in DCs by MSCs was dependent on the expression of TIEG1 in DCs. The study reveals the inability of MSCs from ITP patients to induce tolerogenic ability in DCs. THD could restore the regulatory effect of MSCs on DCs. These findings will help us understand the pathogenesis of ITP, and with appropriate safeguards, THD may benefit patients with ITP.

In view of the numerous clinical observations and laboratory studies that suggest a critical role for the spleen in immune thrombocytopenia (ITP) pathophysiology, we aimed to characterize Th1-associated chemokine receptors CXCR3 and CCR5 and Th2-associated chemokine receptor CCR3 in spleens of ITP patients and assess the significance of their differential expression in the clinical setting. The histopathology of spleens was observed using hematoxylin-eosin staining (HE), and the positive rate of CXCR3, CCR5 and CCR3 expression in spleens of 24 ITP patients and 12 patients with traumatic splenic rupture as normal controls was detected by immunohistochemistry using the SP method. CXCR3, CCR5 and CCR3 protein expression was analyzed by Western blot and mRNA levels were investigated by real-time polymerase chain reaction (RT-PCR). Reactive hyperplasia could be seen in follicles of the white pulp, the germinal central zone was enlarged and the marginal zone was thickened, the central arteries were thickened and fibrotic, and the density of the capillary vessel was increased in ITP patients. ITP group displayed a higher rate of expression of Th1-associated chemokine receptors CXCR3 and CCR5 (83.3 % vs. 75 %, 100 % vs. 83.3 %) but lower rate of expression of Th2-associated chemokine receptor CCR3 (50 % vs. 66.7 %) compared with the controls (P

Background Chemokines and chemokine receptors play important roles in autoimmune diseases; however, their role in immune thrombocytopenia (ITP) is unclear. High-dose dexamethasone (HD-DXM) may become a first-line therapy for adult patients with ITP, but the effect of HD-DXM on chemokines in ITP patients is unknown. Our aim was to investigate the mechanism of pulsed HD-DXM for management of ITP, specifically regarding the chemokine pathways. Methods Th1-/Th2-associated chemokine and chemokine receptor profiles in ITP patients before and after pulsed HD-DXM was studied. Plasma levels of CCL5 and CXCL11 (Th1-associated) and of CCL11 (Th2-associated) were determined by ELISA. Gene expression of these three chemokines and their corresponding receptors CCR5, CXCR3, and CCR3, in peripheral blood mononuclear cells (PBMCs) was determined by quantitative RT-PCR. Results Thirty-three of the thirty-eight ITP patients responded effectively to HD-DXM (oral, 40 mg/day, 4 days). In ITP patients, plasma CXCL11 levels increased, while CCL11 and CCL5 decreased compared to controls (P

We proposed an iterative method for phase retrieval and diffractive imaging based on Babinet's principle and complementary random sampling (CRS). We demonstrated that the whole complex amplitude (not sieved) of an object wave can be accurately retrieved from the diffraction intensities of the object wave sampled by a group of binary CRS masks and the diffractive imaging for the object can be realized through a single digital inverse diffraction. Some experimental results are given for the demonstration. Our experimental results reveal that, using CRS, the influence of a binary random sampling mask on the retrieved field can be well eliminated, and the accuracy and efficiency of the phase retrieval can be greatly improved.

Primary immune thrombocytopenia (ITP) is an immune-mediated disorder in which disturbed cytokine profiles have been found. Interleukin-27 (IL27) has been shown to bear both proinflammatory and anti-inflammtory effects. In the present study, plasma levels of IL27, interferon gamma (IFNG), IL4, and IL17A were determined by enzyme-linked immunosorbent assay in 23 active ITP patients, 20 patients in remission and 20 healthy controls. mRNA expression levels of IL27, EBI3, IL27 receptor (IL27RA), IL17A and RAR-related orphan receptor C (RORC) were determined by real-time quantitative polymerase chain reaction. Significantly lower levels of plasma IL27, IL4, mRNA expression of IL27, EBI3 and higher levels of plasma IFNG as well as mRNA expression of IL17A, RORC were observed in active ITP patients compared with healthy controls or patients in remission. No statistical difference was found in IL27RA mRNA expression or plasma IL17A levels among active ITP patients and controls. A negative correlation was found between the IL27 and RORC mRNA expression levels in active ITP patients. Our data demonstrated that active ITP patients had decreased plasma and mRNA expression levels of IL27, suggesting that it might be involved in the pathophysiological process of ITP.

Objectives: Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by premature platelet destruction induced by autoantibodies directed against platelet glycoproteins (GPs). Despite being a clinically important disorder, ITP lacks a feasible diagnostic assay for routine clinical use. This study was meant to evaluate a newly developed flow cytometric immunobead assay for determination of platelet-bound GP-specific autoantibodies in comparison with indirect monoclonal antibody-specific immobilization of platelet antigen (MAIPA) in the diagnosis of ITP. Methods: Platelet-bound and plasma GPIIb/IIIa and GPIb/IX autoantibodies were determined by flow cytometric immunobead assay and indirect modified MAIPA, respectively. The average fluorescence level for platelet-bound, GP-specific autoantibodies was given as a ratio to three normal controls tested simultaneously. Results: The median value of platelet-bound GPIIb/IIIa and GPIb/IX autoantibodies in ITP group were 3.09 (range 0.78, 30.2) and 3.09 (range 0.72, 19.2), respectively, which were significantly higher than non-ITP group [1.01 (0.67, 5.59) and 1.01 (0.79, 5.56), respectively, P

An array of optical vortices with fractional topological charge is generated using a phase-only Talbot array illuminator and used to sort microparticles. Our theoretical analysis and experimental results reveal that when a particle passes through a fractional vortex array, it will be driven by two forces, intensity-gradient force and phase-gradient force, and the cooperation of these two forces can improve its ability in optical sorting because of the special intensity and phase distribution of the fractional optical vortex array. Larger angle separation could be obtained with moderate laser power.

A phase-only diffractive optical element (DOE) for generating array of optical vortices with high compression ratio is presented. Since it is designed according to the fractional Talbot effect, we name the DOE optical vortex Talbot array illuminator (OVTAI). As an example, an OVTAI for generating a hexagonal array of optical vortices is designed, and demonstrated through displaying the OVTAI on a programmable liquid crystal spatial light modulator. The diffraction properties of the vortex array generated by the OVTAI are observed and analyzed, and an optimal distance for generating sharp ringed vortex arrays is given.

B-cell activating factor belonging to the TNF family (BAFF) is elevated in several autoimmune diseases including immune thrombocytopenia (ITP). High-dose dexamethasone (HD-DXM) has shown its clinical efficacy in ITP patients. The plasma BAFF concentration and BAFF mRNA were measured in ITP patients before and after oral administration of 40 mg/day DXM for four consecutive days by enzyme-linked immunosorbent assay (ELISA) and real-time quantitative PCR. Moreover, we evaluated the effects of DXM on BAFF expression and proliferation of lymphocytes by ELISA, real-time quantitative PCR and cell proliferation respectively in in vitro experiment. Both plasma BAFF concentration and BAFF mRNA were significantly increased in active ITP patients at pretherapy when compared with controls (P

CD4+CD25+ regulatory T cells (Treg) play the critical role in maintenance of peripheral immune tolerance. However, the numbers of naturally occurring Treg (nTreg) that can be isolated from periphery are far too small to be clinically effective. The isolation and expansion of nTreg for treatment of autoimmune diseases encounter great difficulties. Whether autoantigen-specific Treg could be converted from CD4+CD25− T cells in patients with autoimmune diseases has not been reported. Here, we demonstrated that platelet glycoprotein (GP)–specific induced Treg (GP-iTreg) could be generated de novo from nonregulatory CD4+CD25−CD45RA+ cells in patients with idiopathic thrombocytopenic purpura and induced both antigen-specific and linked suppression. GP-iTreg mediated regulatory effects via modulating the T cell–stimulatory capacity of dendritic cells. By investigating the gene expression profile of iTreg-modulated dendritic cells, we provided a genome-wide assessment of the changes induced by antigen-specific iTreg and identified that the Toll-like receptor, Notch and transforming growth factor-β signaling pathways were related to the GP-specific tolerance, with the Toll-like receptor pathway being dominant. The findings in patients with idiopathic thrombocytopenic purpura will facilitate our understanding of the mechanisms of induction and maintenance of autoantigen-specific tolerance and highlight the considerable potential of antigen-specific iTreg for targeted immunotherapy in human auto-immune diseases.

Summary. Background: Platelet glycoprotein (GP)-reactive CD4+ T cells are essential for the stimulation and maintenance of antiplatelet autoantibody production in chronic idiopathic thrombocytopenic purpura (ITP). Blocking costimulatory signals could result in platelet-specific T-cell anergy. Methods: GP-specific CD4+ T cells from patients with ITP were made anergic using cytotoxic T-lymphocyte-associated antigen 4 immunoglobulin (CTLA4-Ig). The CTLA4-Ig-induced GP-specific anergic T cells were investigated for their inhibitory function on GP-reactive T-cell proliferation and antibody production with in vitro culture systems. To further analyze their tolerizing mechanisms, we cocultured GP-anergic T cells with dendritic cells (DCs) from patients with ITP. Results: Our studies demonstrated that the anergized GP-specific T cells have profound effects on both GP-specific T-cell proliferation and antibody production. These anergic T cells exerted their suppressive effects mainly in a cell contact-dependent manner, and they were not constitutively suppressive but required specific antigen stimulation to make DCs tolerogenic. The anergic T-cell-modulated DCs could induce the autoreactive T cells to be tolerant, and this effect was not restricted to T cells of the same specificity. Conclusion: Our studies demonstrate the efficacy of CTLA4-Ig in suppressing the pathologic autoimmune responses in ITP. These findings provide new insights into the underlying mechanisms of anergy induction in chronic ITP.

To investigate the possible correcting of T helper (Th) cytokine profiles by high-dose dexamethasone (HD-DXM) therapy in chronic idiopathic thrombocytopenic purpura (ITP) with active disease, we determined the plasma levels of IFN-gamma, IL-2, IL-4, IL-10, and TGF-beta1 in 52 patients before and after oral administration of 40 mg/day DXM for four consecutive days. The cytokine levels were measured by enzyme-linked immunosorbent assay. The results showed that initial responses were reached in all patients and sustained response (SR) rate is 46.15%. The pretreatment plasma levels of both IFN-gamma and IL-2 were significantly increased and those of IL-4, IL-10, and TGF-beta1 significantly decreased, compared with those of the normal controls (P0.01), indicating a Th1-dominant cytokine profile typically found in ITP. After HD-DXM treatment, IFN-gamma and IL-2 were decreased (P0.01), whereas IL-4 and IL-10 were increased (P0.05). There was no significant difference between the HD-DXM-treated patients and the normal controls (P0.05). TGF-beta1 was also increased (P0.01) after HD-DXM treatment, but still lower than that of the normal controls (P0.05). During following-up, the cytokine profiles in the SRs remained stable compared to the posttreatment level (P0.05), but IFN-gamma and IL-2 levels raised up, and IL-4, IL-10, and TGF-beta1 levels reduced again in the relapsed patients (P0.01). Our data demonstrate that HD-DXM is an effective initial therapy for ITP, and the Th1 cytokine dominance could be corrected by HD-DXM.

A simple and practical system for generation of vector beams with arbitrary polarization and complex-amplitude distributions is proposed. The system mainly consists of a scalar computer-generated hologram (CGH), a small-angle birefringent beam splitter (BBS), and a Fourier lens with a filtering aperture (FA). The CGH is placed in front of the Fourier lens. The BBS is inserted between the CGH and the Fourier lens. When the CGH specially designed according to the method described in this Letter is illuminated by a plane beam or a Gaussian beam, a desired vector beam can be obtained through the FA placed at the back focal plane of the Fourier lens. Because no coupling element and half-wave plate are to be placed between the CGH and the BBS, the extinction ratios of both the two orthogonal polarization components for the vector beam can be better than 10(-5) and so high-quality vector beams can be generated.

Optical vortex beams propagating through atmospheric turbulence are studied by numerical modeling, and the phase singularities of the vortices existing in the turbulence-distorted beams are calculated. It is found that the algebraic sum of topological charges (TCs) of all the phase singularities existing in test aperture is approximately equal to the TC of the input vortex beam. This property provides us a possible approach for determining the TC of the vortex beam propagating through the atmospheric turbulence, which could have potential application in optical communication using optical vortices.

The evolutionary and statistical properties of the optical vortices that exist in random nondiffracting beams (RNDBs) are analyzed. It is found that the phase singularities (PSs) in the RNDBs originate from the zero rings of Bessel beams with the same ring-shaped spatial spectrum structure (but with zero phase fluctuations) as those of the RNDBs provided. It is also found that the average PS density or vortex density is determined by the average duration of the zero rings of the corresponding Bessel function. According to this model, we successfully derived, for the first time to our knowledge, an analytical formula for quantitatively predicting the PS density of the RNDBs. This formula could be helpful for understanding and designing RNDBs in their applications.

A phase derivative (PD) method is proposed for reconstruction of off-axis holograms. In this method, a phase distribution of the tested object wave constrained within 0 to pi radian is firstly worked out by a simple analytical formula; then it is corrected to its right range from -pi to pi according to the sign characteristics of its first-order derivative. A theoretical analysis indicates that this PD method is particularly suitable for reconstruction of slightly off-axis holograms because it only requires the spatial frequency of the reference beam larger than spatial frequency of the tested object wave in principle. In addition, because the PD method belongs to a pure local method with no need of any integral operation or phase shifting algorithm in process of the phase retrieval, it could have some advantages in reducing computer load and memory requirements to the image processing system. Some experimental results are given to demonstrate the feasibility of the method.

We analyze vortex properties of the optical beams generated by a multi-level spiral phase plate (MLSPP) and find that this kind of beams consists of vortex components with topological charges of L − kM , where k is zero or any integer, M is the level number and L is the intrinsic topological charge of the MLSPP. We proved that the orbital angular momentum of the beams generated by a MLSPP reaches its maximum only if the phase steps (or the ratio of M to L ) satisfies some special conditions.

We report a method for generation of arbitrary shape and array of optical vortices by use of a superposition of coherent elementary vortices based on helical phase spatial filtering in spatial frequency domain. In this method, a helical phase spatial filter (HPSF) is placed in the spatial frequency plane of a 4-f imaging processing system. We demonstrated that the output field distribution represents the convolution between the input field and an elementary vortex field introduced by the HPSF, which results in a special shape or array of optical vortices determined by the “degenerate” properties of coherent elementary vortices and the distribution formats of the input field.

An experimental system for measuring the complex vector transmission matrix (VTM) of an anisotropic multiple-scattering medium (AMSM) is proposed. In this system, a simple vector spatial light modulator unit composed of a conventional transmittance spatial light modulator and a small-angle birefringent beam splitter is introduced to realize programmable and quantitative control of both the amplitudes and phases of two orthogonal polarization components of the input vector beam point by point. At the same time, a two-channel angular-multiplexing holographic polarization recording geometry is applied to realize the synchronous holographic measurement of the two orthogonal polarization components of the scattered light field. Using this system, we measured the VTM of an AMSM composed of the ZnO scattering layer. At the same time, we also demonstrated that the system can be directly applied to realize focusing a vector beam through the AMSM based on the measured VTM.

A method for fast reconstruction of off-axis digital holograms based on digital multiplexing algorithm is proposed. Instead of the existed angular multiplexing (AM), the new method utilizes a spatial multiplexing (SM) algorithm, in which four off-axis holograms recorded in sequence are synthesized into one SM function through multiplying each hologram with a tilted plane wave and then adding them up. In comparison with the conventional methods, the SM algorithm simplifies two-dimensional (2-D) Fourier transforms (FTs) of four N*N arrays into a 1.25-D FTs of one N*N arrays. Experimental results demonstrate that, using the SM algorithm, the computational efficiency can be improved and the reconstructed wavefronts keep the same quality as those retrieved based on the existed AM method. This algorithm may be useful in design of a fast preview system of dynamic wavefront imaging in digital holography.

We propose a method for diffraction simulation with both shifted destination window and a large oblique illumination. Based on the angular spectrum theory, we first derive a generalized transfer function (GTF) and a generalized point-spread function (GSPF) suitable for free-space diffraction simulation when both a shifted destination window and a large oblique illumination are taken into account. Then we analyze the sampling error caused by sampling of the GTF and the GSPF for numerical simulation based on fast Fourier transform (FFT), and find out an analytical formula for determining a criteria distance of Zc. Theoretical analysis and simulation results prove that the FFT-based GTF sampling algorithm is valid for diffraction simulation with a diffraction distance less than or equal to Zc, while the FFT-based GSPF sampling is only suitable for the simulation with a distance larger than or equal to Zc. Based on theoretical analysis, we propose the hybrid GTF-GSPF algorithm suitable for simulation of both near- and far-field diffractions with shifted destination window and large oblique source illumination at the same time. Finally, some simulation results are given to verify the feasibility of the algorithm.

To analyze in vitro the effect of mesenchymal stem cells (MSCs) on secreting cytokines by T lymphocytes and ratio of CD4⁺CD25⁺ T cells from patients with immune thrombocytopenia (ITP).Human bone marrow-derived MSCs were isolated by Ficoll Hypaque and cultured for proliferating to passage cells. Allogeneic T lymphocytes of health adults and ITP patients were isolated from peripheral blood by Ficoll Hypaque and nylon cotton column, and the ratio of CD4⁺CD25⁺ T cells was detected by flow cytometry. Then the different amounts of 1 × 10⁴, 5 × 10⁴, 2 × 10⁵ MSCs per well treated with mitomycin as stromal feeder layers were co-cultured with above-mentioned T lymphocytes, 5 days after cocultivation, the ratio of CD4⁺CD25⁺ T cells was detected by flow cytometry and the levels of IL-2, IFN-γ, IL-4, IL-10 were measured by enzyme- linked immune sorbent assay (ELISA).After co-cultured with 2 × 10⁵ MSCs for 5 days, the ratio of CD4⁺CD25⁺ T cells and CD4⁺CD25⁺/CD4⁺ were significantly higher than of separate T lymphocytes in ITP patients [(4.56 ± 0.70)% vs (2.24 ± 0.81)%, (9.91 ± 1.18)% vs (4.08 ± 1.17)%, respectively] (P0.05). To compare with separate T lymphocytes in ITP patients, the cytokine concentrations of IL-2 and IFN-γ from the culture supernatants significantly reduced from (280.47 ± 17.33) pg/ml to (97.21 ± 12.07) pg/ml and from (129.33 ± 16.34) pg/ml to (72.75 ± 7.81) pg/ml, respectively. In contrast, the cytokine concentrations of IL-4 and IL-10 increased from (16.34 ± 2.60) pg/ml to (37.98 ± 4.05) pg/ml and from (54.78 ± 5.62) pg/ml to (113.77 ± 5.68) pg/ml, respectively.MSCs significantly inhibited the cytokine levels of IL-2 and IFN-γ secreted by Th1 cells and promoted the releases of IL-4 and IL-10 by Th2 cells in ITP , thereby regulating the balance between Th1 and Th2 reaction, as well as up-regulating the expression of CD4⁺CD25⁺ T cells in vitro,then induced the immunologic tolerance of ITP.

Summary Background Immune thrombocytopenia (ITP) is a common autoimmune bleeding disorder, in which platelet glycoprotein (GP)IIb–IIIa and GPIb–IX are the two most frequently targeted autoantigens. Our previous studies in animal models of ITP demonstrated that intravenous immunoglobulin G (IVIG) could protect against anti-GPIIb–IIIa autoantibody-mediated thrombocytopenia but failed to ameliorate ITP induced by most anti-GPIb–IX autoantibodies. Objectives The objective of this human study was to evaluate the association between the specificity of antiplatelet autoantibodies and response to IVIG treatment. Patients/Methods In this retrospective study, a cohort of 156 previously untreated adults with severe ITP who underwent IVIG therapy (0.4 g kg−1 day−1 for 5 days) was analyzed. The primary outcome was response defined as platelet counts of ≥ 30 × 109 L−1 and a doubling of baseline counts within 7 days of dosing, and an absence of bleeding. Results and Conclusions Among the 66 patients with anti-GPIb–IX autoantibodies, only 24 (36.4%) achieved a response, as compared with 72 of 90 patients (80.0%) who were negative for anti-GPIb–IX autoantibodies (relative risk 2.2; 95% confidence interval 1.6–3.1). This study found no difference in response between patients with anti-GPIIb–IIIa autoantibodies (61.7%) and those without anti-GPIIb–IIIa autoantibodies (61.3%). Logistic regressions, including main effects and the interaction between these two autoantibodies, showed no influence of anti-GPIIb–IIIa autoantibodies on the effects of anti-GPIb–IX autoantibodies with regard to their association with IVIG response. Thus, in adults with ITP, the presence of anti-GPIb–IX autoantibodies is a predictive factor for poor response to IVIG treatment. Trial registration: ClinicalTrials.gov NCT01666795.

To study CXCR3 and CCR5 chemokine receptor expression in spleens of patients with primary immune thrombocytopenia (ITP) and its clinical significance.The splenectomy specimens from 10 ITP patients (ITP group) and 8 patients with traumatic splenic rupture (normal control group) were studied. Immunohistochemistry (IHC) was used to study the positive rate of CXCR3 and CCR5. Western blot was performed to detect CXCR3 and CCR5 protein expression, while real-time polymerase chain reaction (RT-PCR) was conducted to analyze their mRNA expression.The positive rate of CXCR3 and CCR5 were both higher in ITP group (90% and 100%, respectively) than those in control group (75% and 87.5%, respectively)(P0.05). The differences were statistically significant (P0.05). Protein and mRNA level of CXCR3 in ITP group were 3.0 and 3.5 times as high as those in control group, respectively. Those of CCR5 in ITP group were 1.2 and 1.7 times as high as those in control group, respectively.High expression of CXCR3 and CCR5 may play a part in the splenic immune disorders in patients with ITP.

Vector fields, with spatially inhomogeneous polarization distribution, have become a subject of rapidly growing interest. We introduce a method for generating vector fields and discuss novel properties including orbital angular momentum and three-dimensional optical cage.

Indoleamine 2,3-dioxygenase (IDO) expression in dendritic cells (DCs) can induce or maintain peripheral immune tolerance. Impaired IDO-mediated tryptophan catabolism has been observed in autoimmune diseases. In order to investigate the effects of IDO-mediated tryptophan catabolism and IDO-expressing DCs in immune thrombocytopenia, the concentrations of kynurenine were detected by high-pressure liquid chromatography. The expressions of IDO were analyzed by flow cytometry and western blot analysis. The effects of IDO(+) DCs stimulated with CTLA-4-Ig on T cells proliferation and activation, lymphocyte apoptosis, and Tregs were measured by flow cytometry. We found that the expression of IDO in DCs of immune thrombocytopenia (ITP) patients was significantly decreased. CTLA-4-Ig significantly increased the expression of functional IDO in DCs of ITP patients. IDO(+) DCs stimulated with CTLA-4-Ig suppressed T cells proliferation and activation, promoted lymphocyte apoptosis, and increased the percentage of Tregs. These results suggest that decreased IDO expression in DCs may play a critical role in ITP. CTLA-4-Ig successfully corrected the disorder of IDO expression in ITP. IDO(+) DCs stimulated with CTLA-4-Ig inhibited immune responses by an IDO-dependent mechanism. Increasing the expression and activity of IDO in DCs might be a promising therapeutic approach for ITP.

Orbital angular momentum (OAM), as nature of optical field, has attracted considerable attention, due to its academic interest and potential applications such as quantum information, atomic manipulation, micromanipulation and the biosciences. The well-known OAM carried by an optical field originates from the azimuthal phase gradient of an optical vortex field with a helical phase structure. Here we predict a novel optical OAM, which is induced by curl of polarization. To demonstrate experimentally the above prediction, we present an idea for creating a kind of radial-variant vector fields, which could have all local linear polarization and hybrid states of polarization (SoPs). By specifically arranging the SoPs of the vector fields, new effects and phenomena can be anticipated that can expand the functionality and enhance the capability of optical system. The generated vector fields with the radial-variant hybrid SoPs can carry such a novel OAM. Optical trapping experiments validate that the focused vector fields without any additional phase vortex, as the ring optical tweezers, exert torques to drive the orbital motion of the trapped isotropic microspheres.

Primary immune thrombocytopenia (ITP) is an immune-mediated disorder in which disturbed cytokine profiles have been found. Interleukin-27 (IL27) has been shown to bear both proinflammatory and anti-inflammtory effects. In the present study, plasma levels of IL27, interferon gamma (IFNG), IL4, and IL17A were determined by enzyme-linked immunosorbent assay in 23 active ITP patients, 20 patients in remission and 20 healthy controls. mRNA expression levels of IL27, EBI3, IL27 receptor (IL27RA), IL17A and RAR-related orphan receptor C (RORC) were determined by real-time quantitative polymerase chain reaction. Significantly lower levels of plasma IL27, IL4, mRNA expression of IL27, EBI3 and higher levels of plasma IFNG as well as mRNA expression of IL17A, RORC were observed in active ITP patients compared with healthy controls or patients in remission. No statistical difference was found in IL27RA mRNA expression or plasma IL17A levels among active ITP patients and controls. A negative correlation was found between the IL27 and RORC mRNA expression levels in active ITP patients. Our data demonstrated that active ITP patients had decreased plasma and mRNA expression levels of IL27, suggesting that it might be involved in the pathophysiological process of ITP.

Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by premature platelet destruction induced by autoantibodies directed against platelet glycoproteins (GPs). Despite being a clinically important disorder, ITP lacks a feasible diagnostic assay for routine clinical use. This study was meant to evaluate a newly developed flow cytometric immunobead assay for determination of platelet-bound GP-specific autoantibodies in comparison with indirect monoclonal antibody-specific immobilization of platelet antigen (MAIPA) in the diagnosis of ITP.Platelet-bound and plasma GPIIb/IIIa and GPIb/IX autoantibodies were determined by flow cytometric immunobead assay and indirect modified MAIPA, respectively. The average fluorescence level for platelet-bound, GP-specific autoantibodies was given as a ratio to three normal controls tested simultaneously.The median value of platelet-bound GPIIb/IIIa and GPIb/IX autoantibodies in ITP group were 3.09 (range 0.78, 30.2) and 3.09 (range 0.72, 19.2), respectively, which were significantly higher than non-ITP group [1.01 (0.67, 5.59) and 1.01 (0.79, 5.56), respectively, P0.001] and normal controls [1.02 (0.72, 1.76) and 1.03 (0.79, 1.73), respectively, P0.001]. The receiver-operating characteristics curve analysis showed an area under the curve of 0.895 for GPIIb/IIIa autoantibody and 0.859 for GPIb/IX autoantibody, respectively. Combined detection of GPIIb/IIIa or GPIb/IX autoantibodies by flow cytometric immunobead assay showed a sensitivity of 82.11% for ITP diagnosis.This study demonstrated that determination of platelet-bound, GP-specific autoantibodies by flow cytometric immunobead assay was a convenient, sensitive, and specific test for the differential diagnosis of thrombocytopenic patients.

Indoleamine 2,3-dioxygenase (IDO) can promote peripheral immune tolerance and control autoimmune responses through tryptophan catabolism. Tryptophanyl-tRNA synthetase (TTS) can protect T cells from IDO-mediated cell injury. Impaired IDO-mediated tryptophan catabolism has been observed in some autoimmune diseases.The concentrations of plasma kynurenine and tryptophan were detected by high-pressure liquid chromatography. The expressions of IDO and TTS were analyzed by real-time quantitative polymerase chain reaction and flow cytometry.Compared with healthy controls, the PBMCs of patients with immune thrombocytopenia (ITP) had significantly increased expressions of IDO and TTS, especially IDO. However, the plasma tryptophan concentration was significantly elevated, and kynurenine concentration was significantly reduced in ITP patients. In CD4(+) and CD8(+) T cells of the ITP patients, IDO expressions were significantly lower than those in healthy controls, but in CD19(+) and CD14(+) cells, IDO expression significantly increased. Conversely, TTS expressions in CD4(+) and CD8(+) T cells of the ITP patients were significantly higher than those in healthy controls, but there was no difference either in CD19(+) or CD14(+) cells.These results suggest that the activity of IDO enzyme is insufficient in ITP patients. Increased TTS expressions from CD4(+) and CD8(+) T cells might link to a pathogenic mechanism involved in increasing survival of autoreactive T cells in ITP patients.

The human Fcγ receptor (FcγR) system is composed of 2 opposing families, the activating FcγRs (FcγRI, FcγRIIa, and FcγRIII) and the inhibitory FcγR (FcγRIIb). The disturbed balance of the activating and inhibitory FcγRs has been implicated in the pathogenesis of many autoimmune diseases. In this study, the expression of FcγRs on monocytes was determined in 23 patients with primary immune thrombocytopenia (ITP) before and after high-dose dexamethasone (HD-DXM) treatment. The FcγRI expression was significantly higher in ITP patients and decreased after HD-DXM treatment. The ratio of FcγRIIa/IIb mRNA expression on monocytes was significantly higher in untreated patients than in healthy controls. After HD-DXM therapy, the ratio decreased and the increased expression of FcγRIIb mRNA and protein coincided with a remarkable decrease in the expression of FcγRIIa, FcγRI, and monocyte phagocytic capacity. There was no significant difference in FcγRIII expression on monocytes between patients and controls. In vitro cell-culture experiments showed that DXM could induce FcγRIIa and FcγRIIb expression in monocytes from ITP patients, with FcγRIIb at higher amplitudes. These findings suggested that the disturbed FcγR balance might play a role in the pathogenesis of ITP, and that HD-DXM therapy could shift monocyte FcγR balance toward the inhibitory FcγRIIb in patients with ITP.

To investigate the quantitative and qualitative changes of TCRVα24(+)Vβ11(+) natural killer T (NKT) cells from bone marrow (BM) of aplastic anemia (AA) after in vitro stimulation of α-galactosylceramide (α-Galcer).NKT cells in the bone marrow mononuclear cells (BMMNCs) from either AA patients or healthy controls were enumerated with flow cytometry. BMMNCs were cultured in RPMI1640 medium supplemented with either α-Galcer and rhIL-2 or α-Galcer, rhIL-2 and rhG-CSF. The proliferative capacity of NKT cells was determined by NKT cell numbers before and after in vitro culture. Expression of intracellular IFNγ and IL-4 in activated NKT cells was analyzed with flow cytometry.In AA group, the percentage of NKT cells in BMMNCs was (0.19 ± 0.09)%. Addition of rhG-CSF into the α-Galcer/rhIL-2 culture medium resulted in significantly reduced expansion of NKT cells (67.45 ± 29.42-fold vs 79.91 ± 40.56 fold, P0.05). Meanwhile, addition of rhG-CSF reduced IFNγ positive NKT cells \[(37.45 ± 7.89)% vs (62.31 ± 14.67)%, P0.01\] and increased IL-4 positive NKT cells \[(55.11 ± 12.13)% vs (27.03 ± 9.88)%, P0.01\]. In healthy control group, the percentage of NKT cells in BMMNCs was (0.25 ± 0.12)%. Addition of rhG-CSF into the α-Galcer/rhIL-2 culture medium also significantly reduced expansion of NKT cells (97.91 ± 53.22-fold vs 119.58 ± 60.49-fold, P0.05), reduced IFNγ positive NKT cells \[(28.65 ± 10.63)% vs (50.87 ± 12.66)%, P0.01\], and increased IL-4 positive NKT cells \[(66.53 ± 14.96)% vs (31.11 ± 10.07)%, P0.01\].Compared to those from healthy controls, BMMNCs from AA patiants have a reduced fraction of NKT cells, which possesses a decreased potential to expand in vitro in response to α-Galcer stimulation, and produce more IFNγ(+) NKT1 cells. rhG-CSF, in combination with α-Galcer, confers polarization of NKT cells towards IL-4(+) NKT2 subpopulation.