Comparative Study on Different Remediation Strategies Applied in Petroleum-Contaminated Soils.

Due to the increasing pollution by petroleum hydrocarbons (PHs), it is an important task to develop eco-friendly and highly efficient methods for remediating petroleum-contaminated soils. In this study, bioremediation technology was applied to remediate PHs contaminated soils, and the bacterial community structure and physicochemical characteristics of the soil treated using different bioremediation regimens were analyzed. Compared with the control condition (S0), the PHs removal efficiency of biostimulation (S2) and bioaugmentation (S3) was increased significantly. Combined biostimulation with bioaugmentation (S4) had the highest PHs removal efficiency, up to 60.14 ± 4.12%. Among all the selected remediation strategies (S1-S4, S1: soil moisture content: 25-30%), the bacterial alpha-diversity was higher than in S0. The genera Acinetobacter, Escherichia-Shigella, Bacteroides, Microbacterium, and Parabacteroides were found to greatly contribute to PHs' degradation. In the group S4, the PH-degraders and soil enzyme activity were higher than in the other remediation regimens, and these indices gradually decreased in the mid-to-later periods of all remediation tests. Additionally, the abundance of alkB and nah genes was increased by improving the environmental condition of the microorganism communities. Redundancy analysis (RDA) revealed that the total nitrogen (TN) and total phosphorus (TP) had a positive correlation with total PHs degradation. This study offers insights into the microbial community response to environmental factors during bioremediation, which shows a promoting effect in enhancing the efficiency of PHs remediation.

TNF-α-mediated microRNA-136 induces differentiation of myeloid cells by targeting NFIA.

Immune cell-lineage specification and function are influenced by progenitor origin and environmental factors. The mechanism of differentiation of immune cells, such as neutrophils, monocytes, and myeloid-derived suppressor cells, in inflammatory environments has not been elucidated completely. In this study, we have identified human microRNA-136 as a positive regulator of the differentiation of granulocytes and monocytes. Ectopic microRNA-136 induced cells to express higher levels of CD11b, CD14, and C/EBPε, secrete more cytokines, and synthesize higher levels of reactive oxygen species and H(2)O(2). microRNA-136 was shown to target and degrade multiple differentiation-associated molecules, such as the transcription factor NFIA, which induced the release of another microRNA, microRNA-223, with the ability to promote CD11b expression. Furthermore, microRNA-136 expression was remarkably increased by TNF-α, which activated NF-κB to bind to the DNA-promoter region controlling microRNA-136 expression. Additionally, TNF-α may alter NFIA expression through its modulation of microRNA-136 expression. Thus, TNF-α-mediated microRNA-136 may play a critical role in the generation and differentiation of inflammatory immune cells.

Holographic kinetics for mixed volume gratings in gold nanoparticles doped photopolymer.

A holographic kinetic model is proposed to quantitatively represent the dynamics of mixed volume gratings in a bulk gold nanoparticles (NPs) doped photopolymer. Due to the polymerization-driven multicomponent diffusion, the volume refractive index grating is induced by the periodic spatial distribution of photoproduct while the absorption grating is formed by the periodic spatial distribution of gold NPs. By simulating this model with the characterization of time varying absorption modulation, it is capable to describe the behavior of gold NPs in both the polymerization and the multicomponent diffusion process. The temporal evolution of refractive index modulation and absorption modulation can be extracted, respectively, from a diffraction efficiency curve by fitting the model. The established model could be an effective method for understanding the photophysical and photochemical mechanism of holographic nanocomposite.

Orthogonal reference pattern multiplexing for collinear holographic data storage.

An orthogonal reference pattern multiplexing (ORPM) method for collinear holographic data storage (CHDS) is investigated to increase the data storage density and realize parallel optical image superimposition. Holograms are multiplexed in the same volume of the recording medium with multiple orthogonal reference patterns (RPs). The physical principle of this method is analyzed based on scalar diffraction theory. The orthogonal condition of the RPs is derived in order to suppress the interpage cross talk. The parameters of the radial-line RP have significant influence on the signal-to-noise ratio (SNR) of the reconstructed data page. They are optimized to reduce the intrapage cross talk. With a random binary phase mask (RBPM) located closely before the spatial light modulator, SNR of the reconstructed data page is seven times the SNR without the RBPM. Three data pages are multiplexed in the same volume of the medium using the ORPM method. The reconstructed data pages for the CHDS system show the effectiveness of the RBPM in suppressing the intrapage and interpage cross talk.

Lymph node metastasis in early gastric cancer.

OBJECTIVE: To discuss the clinicopathological factors for lymph node metastasis (LNM) in early gastric cancer (EGC), including age, gender, location, size, macroscopic type, depth of invasion, histological type, and lymphatic invasion, and the regulation of LNM in EGC. DATA SOURCES: The data used in this review were mainly from PubMed articles published in English. The search terms were "early gastric cancer" and "lymph node metastasis". STUDY SELECTION: Articles were selected if they reported the clinicopathological factors and regulation of LNM in EGC. RESULTS: The prognosis of EGC is better than advanced gastric cancer, with over 90% 5-year survival rate. The main risk factors for LNM in EGC are tumor size, macroscopic type, depth of invasion, histological type, ulceration, and lymphatic invasion. CONCLUSIONS: LNM in EGC is a critical factor for assessment of prognosis and determination of therapeutic strategy. Endoscopic mucosal resection or endoscopic submucosal dissection should be considered when patients have low risk of LNM.

Optical fingerprint recognition based on local minutiae structure coding.

A parallel volume holographic optical fingerprint recognition system robust to fingerprint translation, rotation and nonlinear distortion is proposed. The optical fingerprint recognition measures the similarity by using the optical filters of multiplexed holograms recorded in the holographic media. A fingerprint is encoded into multiple template data pages based on the local minutiae structure coding method after it is adapted for the optical data channel. An improved filter recording time schedule and a post-filtering calibration technology are combined to suppress the calculating error from the large variations in data page filling ratio. Experimental results tested on FVC2002 DB1 and a forensic database comprising 270,216 fingerprints demonstrate the robustness and feasibility of the system.

Image rotation measurement in scene matching based on holographic optical correlator.

Based on the stationary random properties of remote sensing images, a correlation model is proposed to resolve the effects of the image rotation and translation on the correlation value in scene matching. The rotation invariance is achieved by measuring the image rotation with the model and compensating the rotation before the 2D translation scene matching. The input image is rotated from -5° to 5° at an interval of 1° and 11 new images are generated. The 11 new images correlate with all the template images and eleven correlation matrices are obtained. The maximum values of each correlation matrix are picked up and they could follow a fixed curve predicted by the model. Fitting the curve, the rotation corresponding to the estimated peak of the curve is considered to be the rotation of the input image. The rotation measurement of the input image can be as accurate as 0.05°. With an extra 36 rotations of the input image, the measuring range of rotation can be enlarged into ±180°. This method could be very fast and accurate for scene matching in the parallel multichannel holographic optical correlator.

Calibration method for inner product calculation by the volume holographic correlator with randomly interleaved images.

A volume holographic correlator is capable of inner product calculations between the input image and multiple stored images in parallel. The inner product that is the center value of the correlation can provide a scalar measure of change between two images. The inner product values are directly acquired by measuring the intensities of the correlation peaks on the CCD. However, the measured intensities are not exactly equal to the theoretical inner product values due to the redundancy correlation. The structure of the correlation peak for randomly interleaved images is analyzed. It can be regarded as two volumes, one pyramid and one prism. The relative inner product value is only determined by the height of the pyramid. The prism, caused by the redundancy correlation, appears as the background noise, which is the main source of the inner product calculation error. A calibration method is proposed to remove the prism from the measured intensity. Based on the geometric structure of the correlation peak, the theoretical expression of the inner product value for the pyramid is derived. A white image is employed as the input image and the measured correlation peak intensity is used to calibrate the inner product value. The calibration method can effectively eliminate the error caused by the redundancy correlation to achieve a high output accuracy of the volume holographic correlator. Experiments are demonstrated for the validity of the method.

Orthogonal-reference-pattern-modulated shift multiplexing for collinear holographic data storage.

A novel hybrid shift multiplexing method for collinear holographic data storage (CHDS) by using orthogonal reference patterns (RPs) is proposed, analyzed, and demonstrated. For this method, holograms are multiplexed by not only shifting the media but also using different RPs. Compared with the traditional method, the shift pitch for the hybrid method is substantially reduced because of the selectivity introduced by different RPs. The interpage cross talk due to Bragg mismatch and degeneracy for multiplexing holograms in the same volume by using orthogonal RPs is also attenuated by utilizing the shift selectivity of the hologram. A 1.5 µm shift pitch is experimentally achieved by using three amplitude RPs in a system that would be 4.5 µm with only one RP. This new method offers an alternative to significantly increase the data density and transfer rate of the CHDS system given that the media has ideal properties.

Channel analysis of the volume holographic correlator for scene matching.

A channel model of the volume holographic correlator (VHC) is proposed and demonstrated to improve the accuracy in the scene matching application with the multi-sample parallel estimation (MPE) algorithm. A quantity related to the space-bandwidth product is used to describe the recognition ability in the scene matching system by MPE. A curve is given to optimize the number of samples with the required recognition accuracy. The theoretical simulation and the experimental results show the validity of the channel model. The proposed model provides essential theoretical predictions and implementation guidelines for using the multi-sample parallel estimation method to achieve the highest accuracy.

miR-223 suppresses differentiation of tumor-induced CD11b⁺ Gr1⁺ myeloid-derived suppressor cells from bone marrow cells.

Tumor-associated factors are related to increased accumulation of CD11b(+) Gr1(+) myeloid-derived suppressor cells (MDSCs). However, the exact mechanism of how genetic factors control the expansion of MDSCs in tumor-bearing hosts remains elusive. Herein, we found that tumor-associated MDSCs and their subsets, mononuclear MDSCs and polymorphonuclear MDSCs, have decreased expression of miR-223 when compared to CD11b(+) Gr1(+) cells from the spleen of disease-free mice. With the differentiation of CD11b(+) Gr1(+) MDSCs from bone marrow cells (BMCs) upon exposure to tumor-associated factors, the expression of both pri-miR-223 and mature miR-223 was downregulated, indicating that the expression of miR-223 could be regulated by tumor-associated factors. Interestingly, miR-223 remarkably inhibits differentiation of BMCs into CD11b(+) Gr1(+) MDSCs in the presence of tumor-associated factors by targeting myocyte enhancer factor 2C (MEF2C). Using reconstituted s.c. tumor models, miR-223 also suppresses accumulation of CD11b(+) Gr1(+) MDSCs, whereas its targeting molecule MEF2C increases the number of MDSCs. Tumor growth is slower in mice infused by miR223-engineered BMCs than in mice infused with control transfected BMCs. As miR-223 and its target molecule MEF2C are highly conserved between mice and humans, the modulation of miR-223 in tumor-induced CD11b(+) Gr1(+) MDSCs may exert an important role in controlling the increased accumulation of CD11b(+) Gr1(+) MDSCs in patients with tumor.

Multi-sample parallel estimation in volume holographic correlator for remote sensing image recognition.

Based on volume holographic correlator, a multi-sample parallel estimation method is proposed to implement remote sensing image recognition with high accuracy. The essential steps of the method including image preprocessing, estimation curves fitting, template images preparation and estimation equation establishing are discussed in detail. The experimental results show the validity of the multi-sample parallel estimation method, and the recognition accuracy is improved by increasing the sample numbers.

Improving signal-to-noise ratio by use of a cross-shaped aperture in the holographic data storage system.

A cross-shaped aperture is proposed to improve signal-to-noise ratio (SNR) in the holographic data storage system (HDSS). Both simulated and experimental results show that higher SNR can be achieved by the cross-shaped aperture than traditional square or circular apertures with the same area. A maximum gain of 20% in SNR is obtained for the optimized cross-shaped aperture. The sensitivities to pixel misalignment and magnification error are also numerically compared.

[Comparison of dispersion parts of conventional spectrometers].

Innovation of conventional spectrometers is of actual technical and economical value. It is also an important way to accelerate the development of spectroscopic instruments. When improving a conventional spectrometer, its dispersion part is pivotal, because it is decisive to the basic performance of the spectrometer. In the present paper, the typical dispersion parts of conventional spectrometers are compared to feature them and find the evolution force among them. The basic characters of the dispersion parts, including spectral range, dispersion power, resolution and throughput, are compared separately and comprehensively by reviewing their decisive factor, formula and typical data. The results not only conclude the feature and the complementariness of the dispersion parts, but also indicate that the trade-off between resolution and throughput is ubiquitous in traditional spectrometers. Further reviewing from this point, the evolution history of traditional spectrometers shows that the conflict between resolution and throughput is an important evolution force. This is a new way to understand the evolution of traditional spectrometers. Moreover, dealing with the trade-off between resolution and throughput correctly will help to analyze and settle the core problem of spectrometers.

Design of freeform mirrors in Czerny-Turner spectrometers to suppress astigmatism.

Astigmatism is left uncorrected in traditional Czerny-Turner spectrometers with spherical mirrors, which leads to low throughput of modern instruments applying line-array detectors. By gradually varying the sagittal curvature, freeform mirrors are introduced to suppress astigmatism for a wide wavelength range simultaneously. So as not to reduce spectrum resolution, further calculations of the light path are performed for extra coma compensation. A design example is presented with optimized parameters. The ray-tracing result has revealed a reduction in sagittal spot size from several hundred micrometers to around 10 microm in the wavelength range from 200 nm to 800 nm.

[Global modeling and analyzing of grating spectrometers].

A method for globally modeling and analyzing grating spectrometers is put forward in the present paper. Different from existing methods which are confined to parts of a spectrometer, the method takes a grating spectrometer as four functional parts, namely imaging optics, detector, reconstruction and display. Effects of each part on spectrum are considered and a global model of the spectrometer is developed, accompanied with its transfer function. With the help of the model and the transfer function, laws of each part affecting the holistic performance are summed up. It is suggested that high quality spectrogram needs enhancing baseband response and reducing spurious response, and reconstruction is an effective way.

Fast associative filtering based on two-dimensional discrete Walsh transform by a volume holographic correlator.

An optical fast associative filtering method based on a multi-channel volume holographic correlator to search the database as a front-end filter is described. The features of searching query are parallelly extracted by a volume holographic correlator based on two-dimensional discrete Walsh transform, and are used to measure the similarity between the query and all the database records. The best matches are picked up for further searching. An experiment is carried out, and the experimental results prove the validity of the method.

[Algorithm for restoring spectrogram with sub-pixel resolution].

Insufficient spatial resolution of detectors is an obstacle to capturing spectra with high resolution. An effective solution is sub-pixel restoration, which can restore a high resolution spectrogram from sub-pixel shifted low resolution ones. In the present paper, an algorithm for sub-pixel restoration is suggested. It utilizes the bidirectional recursive relation between sub-pixel values and estimates each sub-pixel value from both directions of head-end and end-head. As a result, the averaged value will be accepted as the sub-pixel value. Numerical experiments on single gauss profile and superposition ones verified the effectiveness of the algorithm.

Security enhanced optical encryption system by random phase key and permutation key.

Conventional double random phase encoding (DRPE) encrypts plaintext to white noise-like ciphertext which may attract attention of eavesdroppers, and recent research reported that DRPE is vulnerable to various attacks. Here we propose a security enhanced optical encryption system that can hide the existence of secret information by watermarking. The plaintext is encrypted using iterative fractional Fourier transform with random phase key, and ciphertext is randomly permuted with permutation key before watermarking. Cryptanalysis shows that linearity of the security system has been broken and the permutation key prevent the attacker from accessing the ciphertext in various attacks. A series of simulations have shown the effectiveness of this system and the security strength is enhanced for invisibility, nonlinearity and resistance against attacks.

Phase-modulated multigroup volume holographic correlator.

We propose a hybrid multiplexing method for volume holographic correlators based on the combination of orthogonal random phase modulation of an object beam and two-dimensional angular multiplexing of a reference beam. This method implements storing multiple groups of library images in a single storage location and outputting multiple groups of correlation spots by switching the modulation phase masks. Three experiments are designed to test the validity of this method.