Depth multiplexing in an orbital angular momentum holography based on random phase encoding.

The orbital angular momentum (OAM) holography has been identified as a vital approach for achieving ultrahigh-capacity in 3D displays, digital holographic microscopy, data storage and so on. However, depth has not been widely applied as a multiplexing dimension in the OAM holography mainly because of the serious coherence crosstalk between different image layers. The multi-layered depth multiplexing OAM holography is proposed and investigated. To suppress the coherence crosstalk between different image channels, random phases are used for encoding different image layers separately. An image can be reconstructed with high quality at a specific depth from an appropriate OAM mode. It is demonstrated that the depth multiplexing of up to 5 layers can be achieved. This work can increase the information capacity and enhance the application of the OAM holography.

Angular multiplexation of partial helical phase modes in orbital angular momentum holography.

The orbital angular momentum (OAM) holography has been identified as a vital approach for achieving ultrahigh-capacity multiplexation without a theoretical helical phase index limit. However, the encoding and decoding of an OAM hologram require a complete helical phase mode, which does not take full utilization of the angular space. In this paper, the partial OAM holography is proposed by dividing an OAM mode into several partial orbital angular momentums and encode each partial mode with a different target image. An image can only be reconstructed using an appropriate partial OAM mode within a specific illuminating angular range, henceforth holographic multiplexation of images can be realized. This method can significantly increase the holographic information capacity and find widespread applications.

Experimental study on the triaxial mechanical behaviors of the Cemented Paste Backfill: Effect of curing time, drainage conditions and curing temperature.

The application of CPB (Cemented Paste Backfill) can realize the clean, efficient, and safe mining of underground metal mines. Clear understanding on the triaxial mechanical properties of CPB is important to the CPB design and the stability analysis of the backfilled CPB structure. The triaxial mechanical properties of CPB can be significantly affected by the different curing conditions. In this research, triaxial compression tests of the CPB samples were carried out using the GCTS (Geotechnical Consulting & Testing System), and the considered curing conditions include different curing time (1, 3, 7 and 28 days), drainage conditions (drained and undrained) and curing temperatures (20 °C, 35 °C and 45 °C). The measured mechanical parameters were compared and analyzed against the framework of the Mohr-Coulomb criterion. Then, the vertical stress distribution of the backfilled CPB structure was calculated and discussed using the measured mechanical parameters. The results show that with the increase of the lateral constraint ratio (σc/Sd0), the elastoplastic stage of the measured deviator stress versus axial strain curve of CPB sample is gradually obvious. The peak deviator stress (Sdp) and the ultimate axial strain (εu) show the linear and negative exponential increase with the σc/Sd0 respectively. The number of cracks on the fractured surface of the CPB samples gradually decreased with the increase of σc/Sd0. The failure types of CPB samples were changed from tensile failure (σc/Sd0 = 0%) to the mixed tensile-shear failure (σc/Sd0≈10%) and compression-shear failure (σc/Sd0≥20%). Moreover, with the increase of curing time and curing temperature or under the drained curing condition, the peak deviator stress and cohesion (cb) of CPB can be significantly increased, but the corresponding internal friction angle (ϕb) is decreased. The shear mechanical parameters of CPB can significantly affect the vertical stress distribution inside the CPB structure. Therefore, when estimating the vertical stress distribution inside the backfilled CPB structure in engineering practices, it is necessary to focus on the changes of CPB shear parameters (cb and ϕb) caused by different curing conditions.

Resolution enhancement for flexible microscopic imaging based on dictionary learning.

The idea of combining a flexible fiber bundle with the microscopic imaging system provides the possibility of the cross-scale detection of defects and textures on large-scale complex components. However, the pixelization artifacts caused by the inter-core spacing of the fibers degrade the image quality and make it difficult to identify the micro-features. A high-resolution reconstruction strategy is proposed based on dictionary learning. By training the high- and low-resolution image pairs after image registration, a coupled dictionary is obtained. Then high-quality images are obtained from the trained dictionary. Experimental results demonstrate that the pixelization artifacts can be effectively addressed, and the resolution of the reconstructed images can be promoted by 1.8 times.

Favorable prognosis of female patients with nasopharyngeal carcinoma.

The female sex is traditionally considered a favorable prognostic factor for nasopharyngeal carcinoma (NPC). However, no particular study has reported this phenomenon. To explore the prognostic impact of gender on patients with NPC after definitive radiotherapy, we reviewed the clinical data of 2063 consecutive patients treated between 1st January 2000 and 31st December 2003 in the Sun Yat-sen University Cancer Center. The median follow-up for the whole series was 81 months. The female and male patients with early stage disease comprised 49.4% and 28.1% of the patient population, respectively. Both the 5-year overall survival (OS) and disease-specific survival (DSS) rates of female patients were significantly higher than those of male patients (OS: 79% vs. 69%, P < 0.001; DSS: 81% vs. 70%, P < 0.001). For patients with locoregionally advanced NPC, the 5-year OS and DSS rates of female vs. male patients were 74% vs. 63% (P < 0.001) and 76% vs. 64%, respectively (P < 0.001). A multivariate analysis showed that gender, age, and TNM stage were independent prognostic factors for the 5-year OS and DSS of NPC patients. The favorable prognosis of female patients is not only attributed to the early diagnosis and treatment but might also be attributed to some intrinsic factors of female patients.

Study on the Hydroconversion Law of Coal-Based Heavy Fractions with Different Catalyst Contents Based on an Improved Separation Method.

Heavy fractions (e.g., asphaltene and resin) can easily be subjected to physical aggregation and chemical coking reaction through molecular force in the process of lightweight processing and use of coal tar (CT), such that the normal processing and use can be affected. In this study, hydrogenation experiments were performed by regulating the catalyst to oil ratio (COR), while the heavy fractions of the hydrogenated products were extracted based on a novel separation method (e.g., the resin with a poor separation effect and rare existing research). The samples were analyzed through Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, nuclear magnetic resonance spectroscopy, and thermogravimetric analysis. On that basis, the composition and structure characteristics of heavy fractions and the law of hydrogenation conversion were investigated. As indicated by the results, with the rise of the COR, the saturates, aromatics, resins, and asphaltenes (SARA) contents indicated the law of increasing the content of saturate, decreasing the content of other fractions, as well as sharply decreasing the content of asphaltene. Moreover, with the increase of the reaction condition, the relative molecular weight, the content of the hydrogen bonded functional groups and C-O groups, the carbon skeleton properties, the number of aromatic rings, and the stacking structure parameters were progressively reduced. In comparison with resin, asphaltene was characterized by large aromaticity and more aromatic rings, short and less alkyl side chains, as well as more complex heteroatoms on the surface of the heavy fractions. The results achieved in this study are expected to lay a solid basis for the relevant theoretical research and facilitate the industrial use process of CT processing.

Serum CCL2 and serum TNF-α--two new biomarkers predict bone invasion, post-treatment distant metastasis and poor overall survival in nasopharyngeal carcinoma.

PURPOSE: To evaluate the prognostic potential of serum CCL2 (sCCL2) and serum TNF-α (sTNF-α) in nasopharyngeal carcinoma (NPC) before treatment by analysing the expression of these two markers. EXPERIMENTAL DESIGN: Both sCCL2 and sTNF-α were prospectively detected in 297 NPC patients with enzyme-linked immunosorbent assay (ELISA) before treatment. The correlations between sCCL2 level or sTNF-α level and patient's survival were evaluated. RESULTS: For sCCL2, the 5-year overall survival (OS) and 5-year distant metastasis-free survival (DMFS) of high expression group and low expression group were 64% versus 81% and 67% versus 84% (P < 0.05), respectively. For sTNF-α, the 5-year OS and 5-year DMFS of high expression group and low expression group were 62% versus 79% and 66% versus 82% (P < 0.05), respectively. The 5-year OS and 5-year DMFS for both positive patients, one marker positive patient and both negative patients were 53% versus 77% versus 85% and 58% versus 80% versus 86% (P < 0.05), respectively. Concentrations of sCCL2 and sTNF-α in patients with large skull base invasion were higher than those without or with small skull invasion (P < 0.05). Patients who developed bone metastasis alone after radical treatment had higher pre-treatment concentrations of sCCL2 and sTNF-α than those without metastasis (P < 0.001). Multifactorial Cox regression analyses demonstrated that T/N/M classification, chemotherapy, sCCL2 level and sTNF-α level were independent predictors of OS and DMFS of NPC patients. CONCLUSION: High expression levels of sCCL2 and sTNF-α predict bone invasion, post-treatment distant metastasis and poor overall survival in NPC patients.

Expression and clinical significance of Wnt-1 and beta-catenin in nasopharyngeal carcinoma.

BACKGROUND AND OBJECTIVE: As signaling molecule and key component of Wnt/beta-catenin signaling pathway respectively, Wnt-1 and beta-catenin are abnormally expressed in several malignancies and correlate with poor prognosis. This study was to investigate the expression and clinical significance of Wnt-1 and beta-catenin in nasopharyngeal carcinoma (NPC). METHODS: The expression of Wnt-1 and beta-catenin in 111 specimens of NPC was detected by SP immunohistochemistry. Their correlations to relapse-free survival (RFS), metastasis-free survival (MFS) and progression-free survival (PFS) were analyzed. RESULTS: The high expression of beta-catenin was observed in 64 (57.7%) of the 111 cases. Its high expression rate was significantly higher in advanced NPC than in early stage NPC (63.1% vs. 40.7%, p = 0.041). The RFS, MFS and PFS were lower in high beta-catenin expression group than in low beta-catenin expression group (p < 0.05). Cox regression analysis demonstrated that beta-catenin was related to poor prognosis of NPC patients. The high expression of Wnt-1 was observed in 68 (61.3%) of the 111 cases, but its expression had no effect on RFS, MFS and PFS (p > 0.05). CONCLUSIONS: Wnt/beta-catenin signaling pathway may be activated abnormally in some NPC patients. beta-catenin may be a prognostic factor of NPC.