Rewriting Flash Memories by Message Passing

This paper constructs WOM codes that combine rewriting and error correction for mitigating the reliability and the endurance problems in flash memory. We consider a rewriting model that is of practical interest to flash applications where only the second write uses WOM codes. Our WOM code construction is based on binary erasure quantization with LDGM codes, where the rewriting uses message passing and has potential to share the efficient hardware implementations with LDPC codes in practice. We show that the coding scheme achieves the capacity of the rewriting model. Extensive simulations show that the rewriting performance of our scheme compares favorably with that of polar WOM code in the rate region where high rewriting success probability is desired. We further augment our coding schemes with error correction capability. By drawing a connection to the conjugate code pairs studied in the context of quantum error correction, we develop a general framework for constructing error-correction WOM codes. Under this framework, we give an explicit construction of WOM codes whose codewords are contained in BCH codes.Comment: Submitted to ISIT 201

RETRACTED: Asymptotic constancy for a differential equation with multiple state-dependent delays

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).This article has been retracted at the request of the Journal Editor.The article is very similar to the following papers: (1)'Asymptotic behavior of solutions to a system of differential equations with state-dependent delays', by Lijuan Wang, published in J. Comput. Appl. Math., 228 (2009) 226–230. (2) 'Asymptotic behavior of solutions to a differential equation with state-dependent delay' by Lequn Peng, published in Comput. Math. Appl., 57 (2009) 1511–1514.All these articles were written using the same Latex file, treating very similar problems in exactly the same way. The authors of the papers knew about the similarity between the papers, but did not make any reference to each other, and therefore violated the Ethical Rules of Publishing, at the time the papers were submitted for publication. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process

A Novel Method for Detecting p53 Autoantibodies in Sera of Patients with NSCLC

Background and objective Serum autoantibody detection is useful means for the early diagnosis and prognosis of cancer. So our objective was to synthesize peptide array to analyse p53 autoantibodies in the sera of patients with non small cell lung cancer (NSCLC). Methods Cellulose-bound overlapping peptides (12 mers) derived from p53 wild type protein were synthesized using SOPTs synthesis technique by an AutoSpot robot –ASP SL (Intavis, Germany). The membrane was incubated with 1/400 dilutions of p53 monoclonal antibody (Sc-53394) to establish a new approach to detect p53 antibody, and the epitopes of the p53 monoclonal antibody is already known. We analysed the p53 autoantibodies from the sera of NSCLC and controls by peptide array and ELISA. Results We synthesized on cellulose membranes twelve-amino-acid overlapping peptides which included all of the sequences of the polypeptide chain of p53. The p53 autoantibody was positive in seven cases of thirty patients’ sera with NSCLC and was negative in sera of the controls, with the same result of ELISA. Conclusion The peptide array could be applied not only to detect the autoantibodies in the sera of patients with lung cancer, but also to map the epitopes of the autoantibodies which might be useful for the early diagnosis and prognosis of cancer

Expression and Clinical Significance of mTOR and PTEN in Non-small Cell Lung Cancer

Background and objective It has been proved that mTOR was an important signal transduction molecular and protein kinase regulating cell growth and proliferation, and mTOR could activate the downstream protein effector. PTEN could negatively regulate mTOR signal pathway and inhibit its activity. The aim of this study is to detect the mRNA expression levels of mTOR and PTEN gene, which are the key genes of mTOR signaling pathway in human non-small cell lung cancer (NSCLC) tissue. The relationship between mTOR signaling pathway and NSCLC is also explored. Methods Lung cancer tissue specimens were obtained from 65 patients. Adjacent-tumor non-small cell lung cancer tissues from the 30 patients were served as control. The RT-PCR technique was used to detect the mTOR and PTEN gene expression levels. Results The average mRNA expression levels of mTOR gene were significantly higher (0.23±0.16) in lung cancer than in adjacent-tumor tissue (0.12±0.09)(P < 0.01). The average mRNA expression levels of PTEN gene were (0.19±0.28) in lung cancer, while the mRNA expression levels of PTEN gene were (0.53±0.28) in adjacent-tumor tissue (P < 0.01). The levels of PTEN gene expression in non-small cell lung cancer were significantly lower than that in adjacent-tumor lung tissue. There are not significant relationship between mTOR and PTEN gene expression levels and patients’ age, gender, pathological type, differentiation, lymph node metastasis, except tumor size. Conclusion The expression of mTOR is activated in NSCLC. The expression of PTEN is absent or decreased. The mTOR activated in NSCLC may be correlate with the absent or decreased of PTEN. The absent or decreased expression of PTEN and the actived mTOR may play important roles in carcinogenesis and metastasis of NSCLC

Growth of Thin Oxidation-Resistive Crystalline Si Nanostructures on Graphene

We report the growth of Si nanostructures, either as thin films or nanoparticles, on graphene substrates. The Si nanostructures are shown to be single crystalline, air stable and oxidation resistive, as indicated by the observation of a single crystalline Si Raman mode at around 520 cm-1, a STM image of an ordered surface structure under ambient condition, and a Schottky junction with graphite. Ultra-thin silicon regions exhibit silicene-like behavior, including a Raman mode at around 550 cm-1, a triangular lattice structure in STM that has distinctly different lattice spacing from that of either graphene or thicker Si, and metallic conductivity of up to 500 times higher than that of graphite. This work suggests a bottom-up approach to forming a Si nanostructure array on a large scale patterned graphene substrate for fabricating nanoscale Si electronic devices