High-quality coherent ghost imaging of a transmission target.

When the test detector of ghost imaging (GI) is a point-like detector and the detector's transverse size is smaller than the transverse coherence length of the light field at the detection plane, this case is corresponding to coherent GI (CGI) and the imaging result recovered by traditional GI (TGI) reconstruction algorithm is usually bad for a transmission target. Here a CGI scheme of a transmission target is proposed and a corresponding CGI reconstruction algorithm is developed to stably recover the target's image. The validity of the proposed method is verified by both simulation and experiments. Both the simulation and experimental results demonstrate that the target's transmission function can be perfectly reconstructed by CGI. We also show that the imaging quality of CGI with a point-like detector is better than that of TGI with a bucket detector if detection noise exists in the sampling process. Performance comparisons between CGI reconstruction and TGI reconstruction are also discussed.

Disturbance-free single-pixel imaging camera via complementary detection.

We present a technique called single-pixel imaging camera based on complementary detection and optimized encoded modulation (CSPI camera), which can significantly reduce the influence of the disturbance light to single-pixel imaging (SPI). The experiments demonstrates that when the probability of the value "1" for each binary encoded pattern is P=0.5, CSPI camera is still disturbance-free even if the intensity fluctuation of the disturbance light is much larger than the signal's intensity. The reconstruction results of both traditional SPI and differential SPI are also compared. This technique of CSPI camera can dramatically promote real application of single-pixel imaging Lidar.

Sub-Nyquist ghost imaging by optimizing point spread function.

Point spread function (PSF) of ghost imaging (GI) with pseudo-thermal light source doesn't satisfy the property of space translation invariance and existing GI linear reconstruction algorithms offer images with low quality when the measurement process doesn't reach ergodic. By modifying the intensity value of the speckle patterns recorded by the camera in the reference path, the property of PSF can be optimized and a linear reconstruction method called optimized ghost imaging (OGI) is proposed to stably recover the object's image even in the measurements below Nyquist limit. In comparison with existing GI linear reconstruction algorithms, both the simulated and experimental results demonstrate that the image's SNR can be significantly enhanced by OGI especially when the sampling ratio is larger than 0.68 and the detection SNR is greater than 20 dB.

Ghost imaging of blurred object based on deep-learning.

In this paper, a new, to the best of our knowledge, neural network combining a new residual neural network (ResNetV2), the residual dense block (RDB), and eHoloNet is proposed to reconstruct a blurred object. With the theory of ghost imaging, only the bucket signal that passes through the blurred object is necessary for reconstruction. The training sets are ENMNIST, which is used for simulation, and the blurred object is designed by Airy convolution. To test the generalization of the neural network, we use multi-slit as the testing sets. Both simulated and experimental results show that the trained neural network is superior in a generalized reconstruction of the blurred object. In addition, the limitation of the reconstruction is also explained in this work.

Experimental investigation of chirped amplitude modulation heterodyne ghost imaging.

We have constructed a chirped amplitude modulation heterodyne ghost imaging (CAM-HGI) experimental system that demonstrates a robust ability against background light in experiments. In the experiments, the background light is simulated by irradiating a spatiotemporal random modulated light field onto the target. The effects of background light, modulation depth and modulation duration of the signal light source on CAM-HGI are investigated experimentally. The results show that the quality of CAM-HGI can be improved by increasing the modulation depth and the modulation duration of the signal light source, and more importantly, an image with a good signal-to-noise ratio (SNR) can be achieved even when the irradiation SNR is lower than -30 dB. This technique of CAM-HGI has an important application prospect for laser imaging in strong background light environments.

Focal-plane three-dimensional imaging method based on temporal ghost imaging: a proof of concept simulation.

A new focal-plane three-dimensional (3D) imaging method based on temporal ghost imaging is proposed and demonstrated. By exploiting the advantages of temporal ghost imaging, this method enables the utilization of slow integrating cameras and facilitates 3D surface imaging within the framework of sequential flood-illumination and focal-plane detection. The depth information is achieved by a temporal correlation between received and reference signals with multiple-shot, and the reflectivity information is achieved by flash imaging with a single-shot. The feasibility and performance of this focal-plane 3D imaging method have been verified through theoretical analysis and numerical experiments.

Block matching low-rank for ghost imaging.

High-quality ghost imaging (GI) under low sampling is very important for scientific research and practical application. How to reconstruct high-quality image from low sampling has always been the focus of ghost imaging research. In this work, based on the hypothesis that the matrix stacked by the vectors of image's nonlocal similar patches is of low rank and has sparse singular values, we both theoretically and experimentally demonstrate a method that applies the projected Landweber regularization and blocking matching low-rank denoising to obtain the excellent image under low sampling, which we call blocking matching low-rank ghost imaging (BLRGI). Comparing with these methods of "GI via sparsity constraint," "joint iteration GI" and "total variation based GI," both simulation and experiment show that the BLRGI can obtain better ghost imaging quality with low sampling in terms of peak signal-to-noise ratio, structural similarity index and visual observation.

Ghost imaging LiDAR via sparsity constraints using push-broom scanning.

Ghost imaging LiDAR via sparsity constraints using push-broom scanning is proposed. It can image the stationary target scene continuously along the scanning direction by taking advantage of the relative movement between the platform and the target scene. Compared to conventional ghost imaging LiDAR that requires multiple speckle patterns staring the target, ghost imaging LiDAR via sparsity constraints using push-broom scanning not only simplifies the imaging system, but also reduces the sampling number. Numerical simulations and experiments have demonstrated its efficiency.

A novel label-free terbium(iii)-aptamer based aptasensor for ultrasensitive and highly specific detection of acute lymphoma leukemia cells.

Acute leukemia is a malignant clonal disease of hematopoietic stem cells with a high prevalence and mortality rate. However, there are no efficient tools to facilitate early diagnosis and treatment of leukemia. Therefore, development of new methods for the early diagnosis and prevention of leukemia, especially non-invasive diagnosis at the cellular level, is imperative. Here, a label-free signal-on fluorescence aptasensor based on terbium(iii)-aptamer (Tb3+-apt) was applied for the detection of leukemia. The aptamer sensitizes the fluorescence of Tb3+ and forms the strong fluorescent Tb3+-apt probe. The target cells, the T-cell acute lymphoblastic leukemia cell line (CCRF-CEM) combined with the Tb3+-apt probe to form the Tb3+-apt-CEM complex, were removed by centrifugation, and the supernatant containing a small amount of the Tb3+-apt probe was detected using a fluorescence spectrophotometer. The logarithm of cell concentration showed a good linear relationship (R2 = 0.9881) with the fluorescence signal. The linear range for CCRF-CEM detection was 5-5 × 106 cells per ml, while the detection limit was 5 cells per ml of the binding buffer. Clinical samples were collected from 100 cases, and the specificity and positive rates detected by this method were up to 94% and 90%, respectively. Therefore, a single-stranded DNA-sensitized terbium(iii) luminescence method diagnostic was developed which is rapid, sensitive, and economical and can be used for diagnosis of various types of leukemia at the early stage.

Ghost imaging via sparse structured illumination source.

We generate a type of pseudo-thermal light field via sparse structured illumination source. Genetic algorithm is utilized to optimize the source's spatial configuration and the property of pseudo-thermal light field is improved. Both simulated and experimental results demonstrate that the periodic distribution of normalized second-order intensity correlation function is effectively suppressed by optimizing the spatial configuration of sparse structured illumination source and the quality of ghost imaging can be obviously increased. This optimized sparse structured illumination source may be applied to the applications like remote sensing with moving targets.

CD8+ effector memory T cells induce acute rejection of allogeneic heart retransplants in mice possibly through activating expression of inflammatory cytokines.

BACKGROUND: To investigate the effects of CD8+ memory T (Tm) cells and CD8+ effector memory T (Tem) cells on the results of allogeneic heart retransplantations performed in mice. METHODS: A skin transplantation model was used to generate sensitized splenic CD8+ Tem cells for infusion into BALB/c mice. One week after infusion, the BALB/c mice underwent allogeneic heart transplantation in the abdominal cavity. Cyclosporin A was administered via intraperitoneal injection starting one day prior to transplantation to arrest immunological rejection of the transplanted heart. The effects of sensitized CD8+ Tem cells on allogeneic heart graft rejection were examined by monitoring survival of the transplanted hearts, the infiltration of effector memory CD8+ T cells into myocardium, and expressions of inflammatory cytokines in blood serum. RESULTS: Adoptive transfer of sensitized CD8+ Tem cells prior to transplantation induced an acute rejection response which decreased the survival of transplanted hearts. The rejection response was accompanied by an infiltration of CD8+ Tem cells into the transplanted myocardial tissue. Additionally, infusion of sensitized CD8+ Tem cells induced markedly increased expressions of IL-2 and IFN-γ, and decreased expression of TGF-ß in the transplanted hearts, as well as higher levels of IFN-γ and CXCL-9 in blood serum. CONCLUSIONS: The infusion of sensitized CD8+ Tem cells induced an acute graft rejection response and decreased the survival of grafted hearts by regulating the expressions of inflammatory cytokines including CXCL-9, IL-2, and INF-γ. Cyclosporin A had no therapeutic effect on the graft rejection response induced by sensitized CD8+ Tem cells.

Graphene-Based Multifunctional Nanomaterials in Cancer Detection and Therapeutics.

Nanotechnology for early diagnosis and treatment of malignant tumor is a forefront topic in the international field of biotechnology and medicine. In order to improve the effect of cancer therapy, the timely and accurate detection of the cancer is important and necessary. Graphene and its derivatives have various excellent characteristics. For example, biological sensors based on graphene are good at amplifying detection signals, and its derivatives play an important role in the early diagnosis and cancer therapy. In view of this, we discussed the biological sensor application based on graphene and its derivatives in the detection and therapy of cancer.

Recent Progress of Wnt Pathway Inhibitor Dickkopf-1 in Liver Cancer.

Hepatocellular carcinoma (HCC) is one of the most common cancers around the world. Multiple etiologic factors such as virus and environment can lead to HCC. It is a challenge for us to successfully detect early HCC due to the lack of effective characterized and specific biomarkers. However, if the early diagnosis is successfully realized, it provides crucial chance for HCC patients to receive effective treatment as early as possible. Dickkopf-1 (DKK-1) is a secretary glycoprotein, which negatively regulates Wnt pathway through binding to surface receptors LRP5/6 and Kremen 1/2. The expression of DKK-1 is regulated by p53, V-Myc avian myelocytomatosis viral oncogene neuroblastoma derived homolog (MYCN), ß-catenin, etc. Ectopic expression of DKK-1 can inhibit cell proliferation, or induce apoptosis with apoptosis enhancing factors. DKK-1 is low-expressed in many tumors, but overexpressed in others. Growing evidences show that DKK-1 plays complex and different roles in tumorigenesis, tumor progression and metastasis of different cancers. We herein review the recent progress in the expression and function of DKK-1 in hepatocellular carcinoma.

Pulse-compression ghost imaging lidar via coherent detection.

Ghost imaging (GI) lidar, as a novel remote sensing technique, has been receiving increasing interest in recent years. By combining pulse-compression technique and coherent detection with GI, we propose a new lidar system called pulse-compression GI lidar. Our analytical results, which are backed up by numerical simulations, demonstrate that pulse-compression GI lidar can obtain the target's spatial intensity distribution, range and moving velocity. Compared with conventional pulsed GI lidar system, pulse-compression GI lidar, without decreasing the range resolution, is easy to obtain high single pulse energy with the use of a long pulse, and the mechanism of coherent detection can eliminate the influence of the stray light, which is helpful to improve the detection sensitivity and detection range.

Structured image reconstruction for three-dimensional ghost imaging lidar.

A structured image reconstruction method has been proposed to obtain high quality images in three-dimensional ghost imaging lidar. By considering the spatial structure relationship between recovered images of scene slices at different longitudinal distances, orthogonality constraint has been incorporated to reconstruct the three-dimensional scenes in remote sensing. Numerical simulations have been performed to demonstrate that scene slices with various sparse ratios can be recovered more accurately by applying orthogonality constraint, and the enhancement is significant especially for ghost imaging with less measurements. A simulated three-dimensional city scene has been successfully reconstructed by using structured image reconstruction in three-dimensional ghost imaging lidar.

Morphology separation in ghost imaging via sparsity constraint.

The separation of morphology components in ghost imaging via sparsity constraint is investigated by adapting the morphology component analysis technique based on the fact that different morphology components can be sparsely expressed in different basis. The successful separation of reconstructed image plays an important role in the ability to identify it, analyze it, enhance it and more. This approach is first studied with numerical simulations and then verified with both table-top and outdoor experimental data. Results show that it can not only separate different morphology components but also improve the quality of the reconstructed image.

Hypoxic environment of wounds and photosynthesis-based oxygen therapy.

The hypoxic environment is among the most important factors that complicates the healing of chronic wounds, such as venous leg ulcers, pressure injuries and diabetic foot ulcers, which seriously affects the quality of life of patients. Various oxygen supply treatments are used in clinical practice to improve the hypoxic environment at the wound site. However, problems still occur, such as insufficient oxygen supply, short oxygen infusion time and potential biosafety risks. In recent years, artificial photosynthetic systems have become a research hotspot in the fields of materials and energy. Photosynthesis is expected to improve the oxygen level at wound sites and promote wound healing because the method provides a continuous oxygen supply and has good biosafety. In this paper, oxygen treatment methods for wounds are reviewed, and the oxygen supply principle and construction of artificial photosynthesis systems are described. Finally, research progress on the photosynthetic oxygen production system to promote wound healing is summarized.

Experimental investigation of the quality of ghost imaging via sparsity constraints.

Sampling number and detection signal-to-noise ratio (SNR) are two major factors influencing imaging quality. Combining the image's sparsity in the representation basis with the ghost imaging (GI) approach, GI via sparsity constraints (GISC) can nonlocally image the object even when the measurement number is far fewer than the Nyquist criteria required for the conventional GI reconstruction algorithm. The influence of receiving the system's numerical aperture and detection SNR in the test path to GISC is studied through experiments. It is also shown that the quality of GISC depends on the object's sparse representation basis.

The influence of sparsity property of images on ghost imaging with thermal light.

The influence of sparsity property of images on ghost imaging via sparsity constraints (GISC) is investigated. We find experimentally that the reconstruction quality is in proportion to the sparse ratio of images. Employing the method of representation transform to obtain different sparsity properties for the same object, the effect of three sparse representation bases on the quality of GISC is also discussed.

Multiple-input ghost imaging via sparsity constraints.

Usually the test detector of a standard ghost imaging scheme is a bucket detector; here the test detector in the scheme of multiple-input ghost imaging via sparsity constraints (MI-GISC) we proposed is characterized by some sparse-array single-pixel detectors, and the propagation process between the object plane and the test detection plane is also considered. Combining ghost imaging with the target's sparsity constraints, the theory and reconstruction of MI-GISC are investigated. The property and differences between MI-GISC and compressive ghost imaging (CGI) are studied theoretically and backed up by numerical simulations. MI-GISC can be applied in a remote imaging system with a small receiving numerical aperture, improving the reconstruction's quality of the target.