Phase retrieval based on deep learning with bandpass filtering in holographic data storage.

A phase retrieval method based on deep learning with bandpass filtering in holographic data storage is proposed. The relationship between the known encoded data pages and their near-field diffraction intensity patterns is established by an end-to-end convolutional neural network, which is used to predict the unknown phase data page. We found the training efficiency of phase retrieval by deep learning is mainly determined by the edge details of the adjacent phase codes, which are the high-frequency components of the phase code. Therefore, we can attenuate the low-frequency components to reduce material consumption. Besides, we also filter out the high-order frequency over twice Nyquist size, which is redundant information with poor anti-noise performance. Compared with full-frequency recording, the consumption of storage media is reduced by 2.94 times, thus improving the storage density.

Highly sensitive photopolymer for holographic data storage.

The insufficient photosensitivity of conventional organic recording materials such as phenanthraquinone-doped poly(methyl methacrylate) (PQ/PMMA) significantly limits the recording speed in holographic data storage. Accelerating the formation of free radicals using the photosensitizer PQ during the photoreaction process and increasing the C = C double bond concentration of the matrix are effective methods for improving the photosensitivity. Using the above methods, we doped PQ/PMMA with the co-photoinitiator triethanolamine and co-monomer acrylamide to improve the photosensitivity of the material. Compared with the original PQ/PMMA material, the photosensitivity was increased by 10 times, and the diffraction efficiency was increased by 20%. The role of each doping component was studied by characterization and analysis. In addition, the introduction of the cross-linking agent N,N'-methylene-bisacrylamide, having high sensitivity, reduced the shrinkage of the material. We verified the application of the new material in a collinear system, and its high sensitivity showed its great potential for holographic data storage.

Phenanthraquinone-Doped Polymethyl Methacrylate Photopolymer for Holographic Recording.

Phenanthraquinone-doped polymethyl methacrylate (PQ/PMMA) photopolymers are considered to be the most promising holographic storage media due to their unique properties, such as high stability, a simple preparation process, low price, and volumetric shrinkage. This paper reviews the development process of PQ/PMMA photopolymers from inception to the present, summarizes the process, and looks at the development potential of PQ/PMMA in practical applications.

Strategy for Simple Control of High Performance PQ/PMMA Holographic Media.

Holographic data storage technology is a cost-effective solution for long-term archival data storage. However, the development of suitable holographic recording materials remains a challenge. Among these materials, phenanthraquinone-doped poly(methyl methacrylate) (PQ/PMMA) stands out due to its low cost and controllable thickness. Nevertheless, its limited photosensitivity and diffraction efficiency hinder its widespread application. In order to solve these problems, we put forward a kind of convenient and simple, low cost strategy, by adding plasticizer N,N-dimethylformamide (DMF) for preparation of DMF-PQ/PMMA photopolymer, avoid the use of complex compounds. The addition of DMF not only influences the thermal polymerization stage but also forms weak interactions with PQ during the photoreaction process, thereby enhancing the holographic performance of DMF-PQ/PMMA. Consequently, we achieved a remarkable 9.1-fold increase in photosensitivity (from ∼0.35 to 3.18 cm J-1), improved diffraction efficiency by 20% (from 65% to 80%), and reduced volume shrinkage by a factor of 8 (from 0.4% to 0.05%). Furthermore, utilizing a collinear holographic storage system with multiplexing shift at a scale of 5 µm resulted in an impressively low minimum bit error rate (BER) of only 0.36% (with an average BER of 1.4%), highlighting the fast processing capability and potential for low BER applications in holographic information storage using DMF-PQ/PMMA.

Highly sensitive and repeatable recording photopolymer for holographic data storage containing N-methylpyrrolidone.

The low photosensitivity of phenanthraquinone-doped poly(methyl methacrylate) (PQ/PMMA) severely limits its recording speed for holographic data storage. A high-performance holographic recording medium based on a unique combination of N-methylpyrrolidone (NMP) regulated PQ/PMMA has been developed. A NMP-PQ/PMMA photopolymer with high sensitivity, high diffraction efficiency and negligible volume shrinkage was successfully fabricated by tuning the composition of the PMMA matrix by varying the ratio of NMP to monomers. The photosensitivity is increased by 6.9 times (from 0.27 cm J-1 to 1.86 cm J-1), the diffraction efficiency is increased from 60% to > 80%, and volume shrinkage is decreased by a factor of 2 (from 0.4% to 0.2%). Further investigation revealed that the addition of NMP significantly reduced the molecular weight of PMMA and increased the amount of MMA residuals, while also improving the solubility of PQ molecules. More interestingly, for the first time, the NMP-PQ/PMMA material could record data information repeatedly at least 6 times. The present study elucidates that the introduction of NMP not only modulates the molecular weight of PMMA but also enables the residual monomer MMA to more easily combine with PQ to form a photoproduct for improved holographic performance.

Sensitivity-Enhancing Modified Holographic Photopolymer of PQ/PMMA.

Phenanthrenequinone-doped poly(methyl methacrylate) (PQ/PMMA) photopolymers are potential holographic storage media owing to their high-density storage capacities, low costs, high stability, and negligible shrinkage in volume holographic permanent memory. However, because of the limitations of the substrate, conventional Plexiglas materials do not exhibit a good performance in terms of photosensitivity and molding. In this study, the crosslinked structure of PMMA was modified by introducing a dendrimer monomer, pentaerythritol tetraacrylate (PETA), which increases the photosensitivity of the material 2 times (from ~0.58 cm/J to ~1.18 cm/J), and the diffraction efficiency is increased 1.6 times (from ~50% to ~80%). In addition, the modified material has a superior ability to mold compared to conventional materials. Moreover, the holographic performance enhancement was evaluated in conjunction with a quantum chemical analysis. The doping of PETA resulted in an overall decrease in the energy required for the reaction system of the material, and the activation energy decreased by ~0.5 KJ/mol in the photoreaction stage.

Highly Sensitive Photopolymer for Holographic Data Storage Containing Methacryl Polyhedral Oligomeric Silsesquioxane.

Herein, via introducing eight methacryl polyhedral oligomeric silsesquioxane (Ma-POSS), we dramatically enhance the holographic performance of phenanthraquinone-doped poly(methyl methacrylate) (PQ/PMMA) photopolymer with excellent characteristics of high sensitivity, high diffraction efficiency, and neglectable volume shrinkage for holographic data storage, the photosensitivity, diffraction efficiency, and volume shrinkage reaching 1.47 cm/J, ∼75%, and ∼0.09%, respectively. Ma-POSS here dramatically enhances the photosensitivity ∼5.5 times, diffraction efficiency more than 50%, and suppressed the volume shrinkage over 4 times. Further analysis reveals that Ma-POSS obviously increased the molecular weight by grafting PMMA to be a star-shaped macromolecule. And the residual C═C of POSS-PMMA dramatically increased the photosensitivity. Moreover, the star-shaped POSS-PMMA acting as a plasticizer dramatically enhances the mechanical properties and so reduces the photoinduced volume shrinkage of PQ/PMMA. Finally, by the use of the POSS-PMMA/PQ in a collinear holography system, it appeared to be promising for a fast but low bit error rate in holographic information storage. The current study thence has not only successfully synthesized photopolymer materials with potential for highly sensitive holographic storage applications but also investigated the microphysical mechanism of the impact of Ma-POSS on the holographic properties of PQ/PMMA photopolymer and clarified the thermal- and photoreaction processes of the POSS-PMMA/PQ photopolymer.

Differential expression of proteomics models of colorectal cancer, colorectal benign disease and healthy controls.

BACKGROUND: Colorectal cancer (CRC) is often diagnosed at a late stage with concomitant poor prognosis. The hypersensitive analytical technique of proteomics can detect molecular changes before the tumor is palpable. The surface-enhanced laser desorption/ionization-time of flight-mass spectra (SELDI-TOF-MS) is a newly-developed technique of evaluating protein separation in recent years. The protein chips have established the expression of tumor protein in the serum specimens and become the newly discovered markers for tumor diagnosis. The objective of this study was to find new markers of the diagnosis among groups of CRC, colorectal benign diseases (CBD) and healthy controls. The assay of SELDI-TOF-MS with analytical technique of protein-chip bioinformatics was used to detect the expression of protein mass peaks in the sera of patients or controls. One hundred serum samples, including 52 cases of colorectal cancer, 27 cases of colorectal benign disease, and 21 cases of healthy controls, were examined by SELDI-TOF-MS with WCX2 protein-chips. RESULTS: The diagnostic models (I, II and III) were setup by analyzed the data and sieved markers using Ciphergen - Protein-Chip-Software 5.1. These models were combined with 3 protein mass peaks to discriminate CRC, CBD, and healthy controls. The accuracy, the sensitivity and the particularity of cross verification of these models are all highly over 80%. CONCLUSIONS: The SELDI-TOF-MS is a useful tool to help diagnose colorectal cancer, especially during the early stage. However, identification of the significantly differentiated proteins needs further study.

Anti-proliferative effect of an extract of the root of Polygonum multiflorum Thunb. on MCF-7 human breast cancer cells and the possible mechanisms.

The root of Polygonum multiflorum Thunb. (PM) is utilized to treat many diseases associated with aging. Research also indicates that PM inhibits the proliferation of certain types of cancer cells. The aim of the present study was to evaluate the inhibitory effect of PM extract (PME) on the proliferation of MCF-7 cells and to investigate the underlying mechanisms. Inhibition of the proliferation of MCF-7 cells was determined by the MTT assay. Cell cycle distribution and apoptotic rates were evaluated by flow cytometry, and cell cycle and apoptosis-related protein expression was assessed by Western blotting. Apoptotic characteristics of MCF-7 cells were detected by transmission electron microscopy. The present study showed that PME at doses of 100, 150, 200 and 250 µg/ml significantly inhibited proliferation of MCF-7 cells in a time- and dose-dependent manner. Flow cytometry showed that the cell apoptotic rates were 9.1 ± 1.67 and 17.7 ± 2.93% after treatment with 100 and 200 µg/ml PME for 48 h, respectively. The proportions of cells in the G2/M phase were 37.9 ± 1.47 and 42.0 ± 1.71% after treatment with 100 and 200 µg/ml PME for 24 h, respectively. Western blot analysis showed that PME down-regulated the protein expression of Cdc25B and Cdc25C phosphatases accompanied by an increase in phospho-Cdk1, and PME promoted cytochrome c release from mitochondria into the cytosol to activate caspase-9. The present study demonstrated that PME inhibited MCF-7 cell proliferation by inducing cell cycle arrest in the G2/M phase and promoting cell apoptosis. The effects of PME on MCF-7 cells were associated with the modulation of the expression levels of proteins involved in the cell cycle and apoptosis. These data suggest that PME has promise as a treatment against breast cancer by inhibiting the proliferation of cancer cells.

Effects of raspberry phytochemical extract on cell proliferation, apoptosis, and serum proteomics in a rat model.

The red raspberry extract possesses potent antioxidant capacity and anticancerous activity in vitro and in vivo. The objective of this study was to determine whether red raspberry extract affected the cell cycle, angiogenesis, and apoptosis in hepatic lesion tissues from a rat model induced by diethylnitrosamine (DEN) as well as changes of serum proteomics. Rats were treated with red raspberry extract (0.75, 1.5, or 3.0 g/kg of body weight) by gavage starting 2 h after DEN administration and continued for 20 wk. Red raspberry extract inhibited cell proliferation, vascular endothelial growth factor VEGF expression, and induced apoptosis in the hepatic lesion tissues. In addition, 2 protein peaks (2597.93 and 4513.88 m/z) were identified to differentially express in the 3.0 g/kg body weight and positive control groups by serum proteomics. These results suggest that a dietary supplement with red raspberry effectively protects against chemically induced hepatic lesions in rats.

Fresh raspberry phytochemical extract inhibits hepatic lesion in a Wistar rat model.

BACKGROUND: Red raspberry possesses potent antioxidant capacity and antiproliferative activity against cancer in vitro. METHODS: The objective of this study was to determine the protective effects of raspberry 80% acetone extract in a rat hepatic lesions model induced by diethylnitrosamine (DEN). Rats were treated with the red raspberry extract (0.75, 1.5 or 3.0 g/kg of body weight) by gavage starting 2 h after DEN administration and continuing for 20 weeks. RESULTS: A dose-dependent inhibition by red raspberry extract of DEN-induced hepatic nodule formation which stands for hepatic lesions was observed. Corresponding hepatic nodule incidence rates were 45.0, 40.0, 25.0 and 5.0% in positive control, low, middle and high groups, respectively (P < 0.01 or 0.05). Gross findings, histopathological and ultrastructural evaluations of hepatic lesion were performed on 9, 8, 5 and 1 hepatic nodule in positive control, low, middle and high doses of groups, respectively, identified in rats from the respective groups of 20. A decreasing trend of proportions of hepatocellular carcinoma masses accompanied the increasing doses of red raspberry extract. CONCLUSIONS: These findings demonstrate that the potent capacity of red raspberry diet could not only suppress DEN-induced hepatic lesions in rats, but also reduce the definite diagnostic features of neoplasm.